Normally if a cancer cell line is injected into a mouse the cancer cells grow. Some scientists at Wake Forest University discovered a mouse that was immune to injected cancer and have bred it and produced many generations of cancer-proof mice.
A cancer-proof mouse, which can survive being injected with any number of cancer cells, has been discovered by US scientists. The discovery of the resistant mouse could pave the way for future gene or drug therapies if the mechanism by which it fights cancer can be understood
This is amazing for a few different reasons. First, it is amazing that it is possible at all. An immune system that can kill such a large variety of types of cancer which does not appear to cause auto-immune disorders is not something I would have expected to be possible. Cancer cells look too much like normal cells and most cancers (perhaps virally caused cancers are an exception) are probably expressing only genes that naturally are expressed in human cells. So where does the specificity come from that lets an immune system knock out a large variety of cancers? Just figuring it out will reveal very useful knowledge.
What is also amazing about it is that the mutation happened and someone noticed. It is hard to say what the odds are for the occurrence of a mutant that would have the resistance to cancer.until it is discovered how the mechanism works and how many mutations had to happen for a mouse to have cancer resistance. Still, it seems amazing to me.
Here are more details.
WINSTON-SALEM, N.C. – Scientists at the Comprehensive Cancer Center of Wake Forest University have developed a colony of mice that successfully fight off virulent transplanted cancers.
"The mice are healthy, cancer-free and have a normal life span," the 10-member team reported in the Proceedings of the National Academy of Sciences online edition to be published the week of April 28.
The transplantation of the cancer cells in these special mice provokes a massive infiltration of white blood cells that destroy the cancer, said Zheng Cui, M.D., Ph.D., associate professor of pathology at Wake Forest University Baptist Medical Center and the lead scientist
"The destruction of cancer cells by these leukocytes is rapid and specific without apparent damage to normal cells," Cui said. "These observations suggest a previously unrecognized mechanism by which the body can fight off cancer."
The discovery of a genetic protection from cancer in mice "may have potential for better therapy or prevention of cancer in people," the team said. It also could help explain why some people are protected against cancer despite prolonged and intense exposure to carcinogens..
The discovery also could help solve another mystery. For years, scientists have been searching for the mechanism that permits spontaneous regression of human cancers without treatment. Cui said these cases are well-documented, but occur rarely. The new mouse colony gives the team the opportunity to study the mechanism in an animal model.
Cui and his colleagues began the mouse colony almost by serendipity. As part of ongoing cancer studies, they were injecting a virulent type of cancer cell that forms highly aggressive cancers in all strains of laboratory mice and rats. When injected into the abdomen, the tumor grows exponentially, causing the abdomen to fill with fluid within two weeks. The cancer can then progress by metastasizing into the liver, kidney, pancreas, lung, stomach and intestine.
But, said Cui, one male mouse unexpectedly remained free of the cancer despite repeated injections. The Wake Forest team was able to show this was genetic and to develop a colony from that single mouse. The colony, now about 700 mice, remains exclusively at Wake Forest. Meantime, the original mouse "remained healthy, cancer-free and eventually died of old age after a normal lifespan."
When the cancer-resistant mice were bred with normal partners, the researchers found that about half of their offspring were resistant to cancer cells, indicating that this genetic protection is dominant and is likely due to a change in one gene. The resistance continued in future generations.
Depending on the age of the mouse, some had complete resistance -- the cancer never got started -- while others displayed spontaneous regression -- the cancer started developing over a period of a couple of weeks, but then it rapidly disappeared in less than 24 hours.
"The mice became healthy and immediately resumed normal activities including mating," Cui said. They tested them again with another injection of the cancer cells. He said that once the mice developed the protection, they never again developed the cancer.
The researchers said the mouse model "represents a unique opportunity to examine cancer/host interactions."
Cui said the new mouse model also may help in solving another medical mystery -- why cancer becomes more common when people age. The usual explanation is that mutations accumulate in the body, leading to precancerous conditions that eventually become cancer.
But, he said, the mouse model suggests that the body's natural protection -- which scientists call host resistance -- declines with age.
Note that this result suggests another reason why the aging of the immune system is a significant problem. Luckily, it will probably be easier to develop rejuvenating cell therapy treatments for the immune system (also see this post) than for many other systems of the body.
How would a mutation that is found in a laboratory mouse strain be usable to create an anti-cancer therapy for humans? Well, the human and mouse genomes have both been sequenced and they have corresponding sections that can be lined up for 90% of their regions. Once the mutation location(s) responsible for this are found in mice then it is likely there will be a corresponding regions in the human genome. It may be possible to introduce equivalent mutations into the DNA of human leucocyte stem cell lines using gene therapy and then inject those stem cells into humans suffering from cancer. Then the cells would multiply and turn into immune cells that fight cancer. Many parts of the transfer of blood stem cells between humans is routinely done as part of leukemia treatments and for other disease treatments..
This mutation (or set of mutations - the capability may the result of a combination of mutations) is likely to have previously occurred in the wild. The fact that the mutation does not normally occur in wild type mice or naturally in other mammalian species suggests that either protection against cancer was not selected for by evolution because other things were killing mammals first or that the mutation has some cost in terms of reproductive fitness. It will be interesting to see how that shakes out.
Even if the mutation turns out to have some downsides it might still be useful as part of a therapeutic treatment. After all, when the downside of not getting treated is death then the side-effects (whatever they might be) of a revved up immune system may be worth it. Also, it might even be possible to add the mutation in a way that can be turned on and off. Attach the relevant gene to a regulatory region that can be switched on and off by a drug. Then even if there was a side-effect to this capability in the immune system it could be activated only long enough to wipe out a cancer.
Another thing that is great about this discovery is that it provides a model to figure out. Here's an immune system that can wipe out a large assortment of cancers. How? The detective work that will be done to figure that out will yield information that is useful by itself. It is even possible that the discovery of the knowledge of how these mice attack cancer will point the way to how to train an immune system to fight cancer with a method less drastic than gene therapy. Perhaps a vaccine could be developed that would train a human immune system to do the same.
Mice fed every other day had their rate of aging decreased in ways analogous to a calorie restriction diet.
Eating double portions one day and nothing the next delivers the same health benefits to mice as seen in animals whose lifespan has been extended by restricting their calorie intake.
Eat every other day and live longer. The rats fed every other day experienced lower blood glucose and blood insulin just as happens when on calorie restriction diets. But the rats fed every other day had normal body weight.
This might be doable with the development of an appetite suppression drug. One could take it before going to bed and then not eat the next day. Then wake up the following day and pig out.
Update: Mark Mattson, the NIH National Institute of Aging scientist who conducted the study, says skipping meals is probably beneficial.
Nevertheless, Mattson said, "I would be very confident in saying that healthy adults don't need three full meals a day and would be better off skipping one or two. When you go without food, there are benefits. Your cells become more efficient. I haven't eaten breakfast for 20 years."
Mattson said a study is being planned to test the effect of fasting on people. The plan is to compare the health of a group of people fed the normal three meals a day with a similar group, eating the same diet and amount of food, but consuming it within four hours and then fasting for 20 hours before eating again.
Here is the original press release from the NIH/National Institute On Aging on Meal Skipping Helps Rodents Resist Diabetes, Brain Damage.
A new mouse study suggests fasting every other day can help fend off diabetes and protect brain neurons as well as or better than either vigorous exercise or caloric restriction. The findings also suggest that reduced meal frequency can produce these beneficial effects even if the animals gorged when they did eat, according the investigators at the National Institute on Aging (NIA).
"The implication of the new findings on the beneficial effects of regular fasting in laboratory animals is that their health may actually improve if the frequency of their meals is reduced," says Mark Mattson, Ph.D., chief of the NIA's Laboratory of Neurosciences. "However, this finding, while intriguing, will need to be explored further. Clearly, more research is needed before we can determine the full impact that meal-skipping may have on health."
In the study*, published in the Proceedings of the National Academy of Sciences Online Early Edition the week of April 28, 2003, Dr. Mattson and his colleagues found mice that were fasted every other day but were allowed to eat unlimited amounts on intervening days had lower blood glucose and insulin levels than either a control group, which was allowed to feed freely, or a calorically restricted group, which was fed 30 percent fewer calories daily than the control group. Despite fasting, the meal-skipping mice tended to gorge when provided food so they did not eat fewer calories than the control group. This finding in mice suggests that meal-skipping improves glucose metabolism and may provide protection against diabetes, Dr. Mattson says.
In the same study, mice on these three diets were given a neurotoxin called kainate, which damages nerve cells in a brain region called the hippocampus that is critical for learning and memory. (In humans, nerve cells in the hippocampus are destroyed by Alzheimer's disease). Dr. Mattson's team found that nerve cells of the meal-skipping mice were more resistant to neurotoxin injury or death than nerve cells of the mice on either of the other diets.
Previous studies by Dr. Mattson and his colleagues suggested that nerve cells in the brains of rodents on a meal-skipping diet are more resistant to dysfunction and death in experimental models of stroke and other neurological disorders including Parkinson's, Alzheimer's and Huntington's diseases. Dr. Mattson also has found that meal-skipping diets can stimulate brain cells in mice to produce a protein called brain-derived neurotrophic factor (BDNF) that promotes the survival and growth of nerve cells.
Dr. Mattson and his colleagues are currently studying the effects of meal-skipping on the cardiovascular system in laboratory rats. The findings of this study, which compares the resting blood pressures and heart rates of rats that were fasted every other day for six months with rats allowed to eat unlimited amounts of food daily, should be available soon.
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The NIA leads the Federal effort supporting and conducting biomedical, clinical, social, and behavioral research on aging. This effort includes research into the causes and treatment of Alzheimer's disease, Parkinson's disease, stroke and other neurodegenerative disorders associated with age. Press releases, fact sheets, and other materials about aging and aging research can be viewed at the NIA's general information Web site, www.nia.nih.gov.
*RM Anson, Z Guo, R de Cabo, T Iyun, M Rios, A Hagepanos, DK Ingram, MA Lane, MP Mattson, "Intermittent fasting dissociates beneficial effects of dietary restriction on glucose metabolism and neuronal resistance to injury from caloric intake," Proceedings of the National Academy of Sciences Online Early Edition the week of April 28, 2003 http://www.pnas.org/cgi/doi/10.1073/pnas.1035720100
It would be surprising to see pharmaceutical companies try to develop drugs that either stimulate the production of BDNF or that mimic the effects of BDNF.
A widespread lack of trust in their government is causing many Chinese people who suspect they are sick to avoid contact with doctors and hospitals.
"The government has said the people are panicking because they don't understand SARS, but that's wrong," said Kang, the social scientist. "They are panicking because they don't know who to rely on. The migrant workers in Beijing are afraid that if they are quarantined they won't get treated, just left there to get sick and die. Their flight is actually a rational response."
The previous report is more important than the fact that the WHO reports that SARS is declining in many of its major sites of infection.
BEIJING -As the World Health Organization announced that SARS had peaked and is declining in Hong Kong, Singapore and Canada, Chinese officials continue to withhold information crucial to combating the spread of the deadly virus, the U.N. agency's chief representative in Beijing charged Monday.
While some stock markets are rallying in reaction to WHO statements that SARS has peaked in many locations and a lot of people are breathing sighs of relief that perhaps the worst is behind us these optimistic reactions seem premature. SARS is being controlled in highly industrialized countries and also in Vietnam. But it is spreading deeper into China and there are worrying signs that it is getting a hold in India. With a 10th SARS case reported India has been reporting at least one SARS case a day for the last 4 to 5 days.
Medical experts warned that health authorities needed to do more to tackle the disease as SARS had entered the "local transmission" phase in which Indians who had returned to the country carrying the virus were now infecting fellow citizens.
If SARS becomes well established in rural India and rural China then there is no way it is going to be eradicated in the foreseeable future. There will then be a continuing risk that it will spread to still other less developed countries. An increasing portion of the world will come to be seen as made up of high risk destinations to visit. This will cut economic growth in those areas and in the world as a whole.
Individual Westerners who do not travel to regions which have SARS infection are going to continue to be at very low risk of getting the disease. In any locale where SARS shows up in the West the Western governments will conduct fairly aggressive programs to hospitalize sufferers and quarantine those who have been exposed (my guess is that other Western governments are learnng from Toronto to move quickly). The skilled personnel, supplies, and infrastructure are available to stop a local outbreak from getting out of control. Realistically a typical Westerner or resident of other industrialized countries such as Japan will be at greater risk of death from a car accident.
However, the economic impact of SARS is going to be great for the West in part because risk avoidance behaviors in the infected regions and among those who might otherwise travel to the infected regions will be so great. China is going to shut down its stock markets for at least a week. The economic effects of SARS are extending far beyond the infected countries and the global economy is slowing.
There are two big unknowns at this point:
Obviously, the answer to the first question greatly affects the size of the needed economic restructuring. But there are already many signs that computer and communications technologies are being used to reduce the economic impact of SARS. For instance, home banking use is surging in Hong Kong. Also, Video conferencing is enjoying a boom. Teleconferencing, telecommuting, email, mail order shopping, and other means of reducing one's exposure to other people are all helping to reduce the impact of SARS on the world economy.
On the bright side SARS is very mild in children and children who have SARS appear to be much less infectious than adults.
The researchers discovered the two distinct patterns of disease. The five teenage patients had symptoms similar to SARS in adults - muscle pains, malaise, chill and rigour. However, the younger children had mainly coughs and runny noses with no muscle pains or chills.
Update: A measure of the economic impact of SARS on Beijing.
And there is another more ironic proof of the seriousness of the situation — It is dusk here right now, and it is a clear, blue, glorious evening. The quality of this sky you do not see except when someone is in town that the government wants to impress, such as the International Olympic Committee, and the government shuts down the main thoroughfares and any industry that is going to pollute.
There is hope for William Hurt's character in The Big Chill.
Tissue engineers who recently demonstrated penis replacement in animals have now added a vital missing component - nerve cells.
"The nerve cells are very important - they are responsible for all the sensory function," says Anthony Atala, at Boston Children's Hospital. "In order to do complete [penile] replacements we need to make sure all of the parts are there, including the nerves."
Keep in mind FuturePundit's rule for biotechnology: any biotechnology developed for repair will eventually be used for enhancement. There will be a big demand for this.
Biotechnology offers other promising future improvements. A couple of years ago a report was made on growth of breast tissue. The days of silicone implants are numbered.
Preimplantation Genetic Diagnosis (PGD) is done to embryos in vitro to identify embryos which are free of specific genetic disorders. In Vitro Fertilization (IVF) followed by PGD was first performed in 1989 and is now widely available. In Sydney Australia 74 babies have been born who were the result of PGD screening.
A special investigation by The Daily Telegraph today reveals she is one of 74 babies born in Sydney since the genetic screening program began in the late 1990s.
The particular clinic featured in this article, Sydney IVF can currently screen for 37 different genetically caused disorders.
Dr Kylie De Bore, from Sydney IVF, said the service was now available to rural families who previously had to come to Sydney for it. "We can screen for 37 disorders, because families have come to us with that many diseases," she said. "It is not restricted to those."
As the cost of DNA testing declines it seems likely that many people will elect to have tests done on themselves and their mates before conceiving children. There are already many genetic diseases such as Thalassemia, Tay Sachs, Cystic Fibrosis, and Retinitis Pigmentosa which could be avoided thru use of PGD. As the list of known genetic disorders and methods to test for them grow the value of PGD will increase.
Most genetic variations that cause differences in offspring are not diseases. Genetic variations affect eye color, hair color, height, body build, proneness to depression, proneness to obesity, intelligence, personality, and a great many other characteristics about which most people have preferences. We all have characteristics that we have gotten from one of our pairs of chromosomes. When someone reproduces there is currently no way to control which of each pair of chromosomes gets passed along. If, say, someone knew that for their genetic complement only one of a particular pair of chromosomes coded for higher intelligence or a happier disposition one can easily imagine that that person would elect to use PGD to make sure that their offspring received the chromosome that coded for the desired feature.
Most people do not have the genetic variations for the big genetic disorders. But everyone who has children has a set of preferences about what they want those children to be like. Therefore it stands to reason that the real big future increase in demand for PGD will come when it can be used to exert some degree of control over the passing along of genetic variations that are not genetic disorders. PGD will therefore become much more popular once the effects of a much larger number of genetic variations become known and testable.
The biggest problem with PGD that will limit its usefulness is that for every trait to be selected for at the same time the number of embryos goes up by a factor of 2 or 3 or 4 (depending on whether it is a dominant or recessive trait and whether each parent has 0, 1, or 2 copies of the desired genetic variation). The number of needed embryos quickly becomes too large for too many different traits.
Scientists hope to improve the technology to the point where it can screen for one, maybe even two, positive 'traits' - for example blue eyes and height. That would still rule out the ideas of the genetic visionaries like Stock, who think PGD could be the first step to 'designer babies' and the re-engineering of mankind, by allowing parents to select among their embryos for all sorts of desirable (to the parents) qualities. The reasons this cannot work are not technical so much as statistical, to do with the way genes are passed on through sex. To screen for two traits you need at least 16 embryos, for three, 64 embryos and so on. Since the maximum number of embryos an IVF procedure produces are typically between 16 and 20, you can do the sums.
What is needed is either the ability to select individual chromosomes by separating them out and choosing which ones to recombine or the ability to do gene surgery to chromosomes to introduce desired genetic variations into an embryo. The gene surgery style of gene therapy is the technique that will ultimately obsolesce the need to generate a large number of embryos with IVF in order to get one that has the desired characteristics. The ability to change the genetic sequences in chromosomes will allow a single IVF embryo to be reshaped to have any desired genetic variations.
Air flights are not a huge source of risk for SARS infections. Aircraft use high-efficiency particulate air (HEPA) filters and take all bacteria and viruses out of the air at a very fast rate. Airplanes have better air filtering than commercial buildings.
Plane air is completely replaced with air from outside the aircraft 20 to 30 times every hour. This compares favourably against one to three times an hour in a typical building and five to seven times in a hospital operating theatre.
Granted, one could be seated on an aircraft right next to someone who has Severe Acute Respiratory Syndrome (SARS) and that person could cough on you. But consider the odds. The vast majority of those who have SARS are on the ground at any given time. Most do not fly from one place to another before being diagnosed and hospitalized. Few SARS cases to date have been traced back to exposures that happened on aircraft.
The biggest single kind of location for passing SARS on has been in hospitals. But most hospitals do not have SARS cases and so hospitals outside of areas which have a high level of SARS cases do not pose a risk as a source of SARS infections either.
The biggest danger from air flight comes from flying to a place that has a lot of SARS cases. Well, anyone who is worried about catching SARS should avoid visiting those (primarily East Asian) locations. The biggest danger to the rest of the world for SARS comes from the fact that people can fly from SARS-infected areas while still at early undiagnosed stages of infection. The greater danger from infected air passengers comes from the possibility that they will pass SARS along while staying for days at their destinations.
Public health experts are becoming increasingly pessimistic about the prospects for stopping the spread of SARS.
With infections now confirmed in two-thirds of China's provinces and mounting daily, ''hope dwindles'' for wiping out the disease, WHO virologist Wolfgang Preiser said from Shanghai. Even in ''Singapore and Hong Kong, very rich places, they still have problems. We are worried about the spread to poor provinces, maybe countries such as India and Bangladesh,'' where ''we don't think they have the capacity to stem the tide once it's introduced.''
''It may have happened already,'' he said.
Within the past day 3 new cases of SARS have been identified in India.
The Health Ministry has confirmed three more cases of SARS in India, which takes the total number in the country to seven. Of the three freshly confirmed cases, one is being treated in Kasturba Hospital, Mumbai, the second in Apollo Hospital, Kolkata and the third in Naidu Hospital, Pune.
If it was my decision to make I'd order the cessation of all commercial passenger flights between East Asia and the countries of the Indian subcontinent and Africa. Those countries do not have the capacity to contain SARS. They are too poor and most of their populations have little or no access to modern health care facilities.
Poor countries in the Indian subcontinent such India are unwilling to take sufficiently drastic steps to stop SARS in advance of a major SARS outbreak in their region. This is foolish. They lack the infrastructure needed to control SARS. As a result, the industrialized countries will have to adopt very rigorous measures at borders and ports of entry to detect SARS carriers because SARS is going to become endemic in much of the world. Thermal imaging and testing for SARS in all arriving and departing passengers will have to become routine at all ports of entry.
Reliable, accurate, and cheap DNA-based Real-Time Polymerase Chain Reaction (RT-PCR) SARS tests are the greatest hope the industrialized countries have for controlling SARS in a way that minimizes the economic impact. An ideal test would be able to use sputum so that a nurse would not be needed to draw blood. To allow testing of large volumes of business travellers an ideal testing device would need to be automated and have a high thru-put rate.
If all SARS carriers could be identified among international travellers even before they boarded aircraft to fly to a SARS-free country then regular business and holiday travel between SARS-free countries could proceed as normal. Also, anyone willing to risk going to an area where SARS is present would not need to be quarantined on return. Patterns of business meetings could be shifted to allow people from SARS-infected areas to travel to SARS-free areas to facilitate customer-supplier meetings. Then people in low risk areas would not have to travel to high risk areas to do business with the high risk areas.
If Taiwan could develop large-scale DNA-based SARS testing systems and use them to make Taiwan SARS-free then Taiwan could gain an advantage by making Taiwan as a place where mainland Chinese businessmen could travel to meet with businessmen from other parts of the world to do deals. Everyone coming to Taiwan could be tested before and on arrival for SARS virus. That way SARS carriers could be kept out. Business could be done in a safe environment fairly close to China. This would reduce the economic disruption that SARS is causing.
There are countries that are willing to take drastic steps. For instance, in order to keep out new cases of SARS Vietnam may close the 800-mile border it has with China.
Vietnam's northern Quang Ninh province, home of the Halong Bay tourist attraction, began barring Chinese tourists at its land border gates and waterways. Hanoi's health ministry has recommended the country seal all its borders with China indefinitely.
Countries that lack the capacity to fight SARS should be willing to close their borders to visitors from countries which have SARS cases.
The New York Times has an excellent long article that traces the spread of SARS. While China made huge mistakes in its handling of the crisis Singapore shines as a textbook example of how to aggressively quarantine and isolate potential SARS carriers.
But even in a small country, placing thousands on quarantine has been a strain. Last Monday, after a case of SARS was discovered in a vendor at Singapore's largest vegetable market, the Ministry of Health ordered all 2,400 food sellers to report for quarantine, up from a total of 467 quarantined before. Since 80 percent of the country's vegetables pass through the Pasir Panjang Market, restaurants were bracing for a shortage of greens.
Hong Kong has done a much worse job than Singapore in protecting health care workers.
In Singapore, with its aggressive system of identifying and isolating SARS patients, no health care worker has been infected for over three weeks. But in Hong Kong, 2 to 10 doctors and nurses are falling ill each day, in part, health officials there say, because doctors are still not identifying them as SARS victims early enough and are admitting them to ordinary wards.
Only recently -- weeks, if not months, after SARS hit -- have officials in China and Canada begun cordoning off entire buildings containing infected patients. Physicians such as Abraham Verghese say that slow response permitted the deadly virus to infect many others in their own countries and beyond. "The lesson of Hong Kong, China and, to some degree, Singapore is if you don't aggressively isolate, this thing can get out of hand," said Verghese, director of the Center for Medical Humanities and Ethics at the University of Texas Health Sciences Center at San Antonio.
The long incubation period helps SARS to spread around the world.
Its apparent incubation period of two to 10 days is long enough for infected people who are asymptomatic to travel "from one city in the world to any other city having an international airport".
SARS is most likely a coronavirus. Other known coronaviruses can survive on surfaces for 24 to 48 hours.
Research done decades ago showed that the type of coronaviruses that cause many colds can remain viable on surfaces for 24 to 48 hours, depending on air temperature and humidity.
The US CDC reports that there is a preliminary study done in Hong Kong that shows SARS can survive on an exposed surface for at least 24 hours.
How long do coronaviruses survive in the environment?
In general, enveloped viruses such as coronaviruses do not last a long time in the environment. In earlier studies, a different coronavirus was shown to survive for up to 3 hours on surfaces. At this time, it is uncertain how long the newly discovered coronavirus associated with SARS can survive in the environment. In one preliminary study, researchers in Hong Kong found that both dried and liquid samples of the new coronavirus survived as long as 24 hours in the environment. Additional studies are under way to examine this important question.
People who live in areas where SARS is present should wash their hands frequently, avoid touching their faces or other parts of their bodies with their hands, and minimize the number of surfaces they touch in public areas. There are lots of ways to reduce one's need to touch surfaces. Do not use hand rails. Keep your hands on your lap when sitting in a public place. Use a stick or other object to press elevator buttons. Become more aware of where you are going and what you will have to touch in order to get there.
Update: If SARS does make it to the less developed countries the number of peope killed could be enormous.
With many cases still unresolved, a better current estimate of the deadliness of SARS may be the number of deaths as a proportion of resolved cases. Those numbers for Hong Kong, Canada and Singapore are 15.8, 18.3 and 13.7 per cent. But these too could be misleading if, for example, it takes longer to recover from a disease than to die from it.
There are other indications that the SARS death rate may be higher than expected. Mortality among infected SARS patients might end up being in the range of 8% to 15% of infected patients. Keep in mind that the death rate varies as a function of age and the death rate is higher in the elderly. Still, overall it is lookiing like the death rate from SARS is going to turn out to be at least 10%.
"If one looks carefully at the WHO figures on mortality and recovery rates, it is running, unfortunately, at 10 per cent," Professor Roy Anderson of Imperial College said.
Update II: Chinese infectious disease experts see a coming third bigger wave of SARS infections in China.
Bi and other experts have said that Beijing officials did not take adequate measures last week to stop Beijing's huge migrant labor population from returning home, and thereby possibly spreading the disease across China.
"The government held meetings for hours with no decision and meanwhile, everybody left town," Bi said. "Beijing is the second peak of the disease. The third one, in the countryside, will be much, much higher."
My fear about the coming third wave is that it will spread SARS into areas adjacent to China. Granted, most land borders of China are in pretty sparsely populated and harsh environments. But SARS could spread across Central Asia and eventually into more densely populated Asian countries.
Update III: Two more cases of SARS reported in Calcutta and Bombay.
Two more cases of Severe Acute Respiratory Syndrome (Sars) have been reported in India, taking the total number of people infected with the pneumonia-like virus there to nine.
SARS cases seem to be popping up in India daily. This is not good. All it would take is for one of these cases to be a "super-infecter" (also called "super-carriers", "super-spreaders" or "hyper-infecters" in some reports) for the disease to start spreading rapidly there.
Keep in mind that SARS cases in India are orders of magnitude more significant than SARS cases in more developed countries because India is far less able to control the spread of a disease. Places like Canada, the United States, Taiwan, and Singapore have the ability to identify cases, isolate them, trace those who might have been exposed, and generally take the steps that will eventually put a halt to the chain of spread. But if SARS makes it into areas where there are large numbers of poor people and primitive health care the disease will become a greater threat to the entire world. Pay especial attention to reports of SARS cases in the Indian subcontinent and Africa. The battle to prevent a global SARS pandemic will be won or lost in the poorest countries.
Growing fear of Severe Acute Respiratory Syndrome (SARS - also called atypical pneumonia in the Chinese media) has caused 1 million people to flee Beijing for other parts of China.
There was a continued exodus from Beijing today as thousands of people attempted to flee the epidemic and return to their home towns all over China. At the Beijing airport, travelers wearing face masks boarded planes out of the city. Local journalists estimated that almost 1 million people, about 10 percent of the population, had already left the capital.
This is an astounding figure. When is the last time that so many people took such drastic action in such a short period of time in response to a natural biological threat? Imagine how people would respond today to an even bigger infection threat. SARS does not spread as easily as influenza. Some day a new influenza strain that is more lethal than the typical influenza strains will arise. It could cause panic around the world.
The rush to flee Beijing has been fueled by the fear that the government would declare martial law and close off the city from the rest of China. The government has had to announce that it would not impose martial law but it is unlikely that the Beijing public believes it.
This is guaranteed to spread SARS further and faster. Infected people riding on airplanes, trains, and buses will pass the disease along to other passengers. They will also pass it on to people they have contact with at their destinations.
The treatment of those suspected of being exposed to SARS in Beijing is considered to be so harsh that people may be hiding their SARS symptoms from the authorities.
Sars suspects are being victimised in Beijing, where thousands have now been put in compulsory quarantine, a World Health Organisation specialist, Dr Wolfgang Preiser, said yesterday.
"If you make it hell for them, they go into hiding," Dr Preiser, a German virologist, told reporters in Shanghai.
While some might cheer the prospects of the Chinese government coming under intense criticism from its own population for the government's handling of SARS keep in mind that a revolution in China would by itself kill millions and that the chaos of a revolution would cause SARS to spread even faster.
Supermarkets reported a roaring trade in staples such as rice and cooking oil as rumors swirled the city would be isolated, while many other shops simply closed up as scared residents stayed at home.
At least this is a rational response. To reduce the risk of exposure in a high infection area it makes sense to buy a lot of food at a time and shop less often. It also makes sense to shop during the off-hours to reduce the number of people one is exposed to. If there was a big outbreak it would make sense to have open air markets so that the air would be dispersed quickly.
There is lots of bad news about Severe Acute Respiratory Syndrome (SARS). SARS is continuing to spread and to establish itself in more locales. The death rate has risen. It appears to mutate rapidly. There appears to be a more lethal strain that also infects the intestines and SARS is causing kidney failure in some patients. Tens of thousands of people (if not more) are fleeing Beijing and in the process helping to accelerate the spread of SARS to more parts of China. Effective drug therapies and vaccines are both distant prospects.
Different SARS coronavirus isolates have been sequenced and compared and many DNA sequence differences have been found.
The mutations were seen in all five of the viruses' known functional genes, with most of them occurring in the gene that carries the instructions for the distinctive spikes that jut from the outside of the virus, according to Siqi Liu, associate director at the Beijing Genomics Institute, part of the Chinese Academy of Sciences.
Those mutations on the outer coating are important because they can create new strains of the virus that are immunologically distinct. A person who has already been infected by SARS and recovered from it would be at risk of reinfection if exposed to a different strain of SARS that had undergone a lot of mutations in genes that code for outer layer proteins. Also, rapid mutation that generates immunologically different strains makes the job of development of vaccines more difficult and makes the period of protection from a vaccine version shorter.
"The ability of the virus to mutate has been a real problem in poultry vaccines. "The virus has the ability to change quite quickly - a vaccine might be suitable for a while, but not forever."
As I've previously posted, vaccine development time for SARS is measured in years. Well, this news that SARS is mutating rapidly will most likely lengthen the amount of time it will take to develop a vaccine. This is not good.
Rapid mutation can lead to more virulent strains. A more deadly SARS strain that attacks the intestinal tract may have already arisen.
The Amoy Gardens patients are three times as likely to suffer early diarrhoea, twice as likely to need intensive care and less likely to respond to a cocktail of anti-viral drugs and steroids. Even medical staff who caught the infection from Amoy Gardens patients are more seriously ill, Yuen said.
SARS is attacking the kidneys in some patients
Tom Buckley, the head of the intensive care unit at Hong Kong's Princess Margaret Hospital, said organ failure was also now becoming more common.
"Initially patients were presenting with just respiratory failure," Dr Buckley said. "Now we're seeing renal failure and other organ failure."
The death rate for older folks is high.
Statistics in Hong Kong show that the death rate among people younger than 55 is 3.6 percent. For patients between 65 and 75, it is 18.9 percent. For those older than 75, the death rate is 28.6 percent.
The death rate from SARS in Hong Kong has increased to 7.2 per cent of reported cases - up from about 5 per cent earlier in the crisis - and officials fear it may go higher.
There are a number of possible reasons why the death rate is increasing. It could be that many of the initially infected tended to be healthy business travellers and health care workers. Now SARS is spreading from them to their families including older folks who are more at risk of dying from infections. Or the virus could be becoming more deadly as it mutates. Or some people may have been sick for weeks before finally succumbing. The real explanation may turn out to be a combination of factors.
The schools are closing in Beijing China.
CHINA: Beijing closed schools for two weeks and sent 1.7 million pupils home yesterday as the country struggled to contain a Sars outbreak thought to have originated in its south.
A major Beijing hospital has been quarantined.
The 1,200 bed Beijing University People's Hospital was sealed off because of SARS today and police were posted to stop people going in or out, hospital staff said.
People are fleeing Beijing by the thousands.
BEIJING, April 23 -- Thousands of people mobbed Beijing's West railroad terminal today in desperate attempts to flee the city as the capital reported another triple-digit increase in the numbers of people infected with SARS and nine more deaths.
Flight of people from infected areas is helping to spread SARS further.
But the relative safety of many of the provinces could prove shortlived if the infection is spread by the railway system.
If the infection is spread by the railway system? Why wouldn't it be spread that way? The infection is already being spread to many provinces of China. Surely some of that spread is happening via rail travel. But cars, airplanes, and other means of transportation are surely contributing as well.
When people start trying to get rail tickets for any place they can get a ticket for then real panic has set in.
Laden with burlap bags and potato sacks, they boarded trains for whichever destination they could get a ticket as the death toll jumped by 25 per cent in the Chinese capital.
Think about it. People are fleeing in panic from the capital of the world's most populated country. Most of the country has health care facilities that are primitive compared to Beijing's. People are spreading out to those more primitive places. My guess is that SARS will achieve pandemic status in China. The Chinese government's honesty (or lack thereof) in reporting SARS cases is becoming irrelevant as SARS spreads into the poorest areas of China. We will not know how many people in China have SARS because most of the future Chinese sufferers will be in areas too primitive for them to be seen by qualified medical professionals.
At least the people fleeing Beijing are trying to avoid enclosed areas where the risk of breathing airborne virus particles is greater.
A sea of faces in white cotton masks scanned coveted train tickets, waiting for hours outside in the chilly air rather than linger in crowded, enclosed waiting rooms.
The WHO says do not travel to Beijing or Toronto.
BEIJING/TORONTO (Reuters) - Saying SARS was still spreading out of control, the World Health Organization tightened travel advisories on Wednesday, adding Beijing and Toronto to the list, while authorities in Beijing started quarantines.
Canadian authorities are upset by this advice.
Canada has responded angrily after the World Heath Organization (WHO) listed Toronto with Beijing and China's Shanxi province as places travellers should avoid because of the danger of Sars.
The Canadian government is being parochial. Steps to stop the spread of SARS need to be taken before it becomes an even bigger threat. The WHO should have gone much farther and told people to avoid China entirely. Plus, it should have asked that people in infected areas not travel from those areas.
China's government waited too long before acting. The spread of SARS to the poorer provinces of China makes it unlikely that the Chinese government will succeed now in stomping out SARS entirely. That, in turn, increases the odds that SARS will spread from China to even less developed countries. If SARS becomes established in India or, even worse, in Africa then it seems likely to achieve pandemic status.
The problem is that the more places SARS becomes established the greater the chance that on any given day there will be someone bringing SARS into areas where it hasn't become established. Plus, the greater the panic becomes the more people will flee infected areas and infected countries and carry SARS with them in the process.
The economic costs of trying to prevent the spread of SARS need to be weighed against the economic costs of what happens when it becomes established. In countries where SARS has taken root the economic costs of people becoming afraid to travel, go to jobs, meetings, and to go shopping in markets is becoming enormous. The Western industrialized countries need to work hard to prevent SARS from becoming big enough to start changing the behavior of a substantial portion of the population of each country. The economic costs would become staggering if SARS did come to be viewed as a threat to the population of the Western nations.
Countries should reduce the issuance of visas for people from infected areas. Some countries already are doing so. Saudi Arabia has stopped issuing visas to visitors from several East Asian countries. So has Israel. Belize has banned visitors from several countries including Canada. Singapore, Hong Kong, Tokyo-Narita, Beijing and other cities with international airports are installing thermal imaging systems to scan passengers for fevers. These are certainly steps in the right direction. More international airports should institute thermal imaging screening and other methods of screening incoming passengers. Unfortunately, it is the countries that are least able to afford to handle a SARS outbreak that will also be least able to afford extensive screening measures at their international airports.
Fast DNA-based SARS tests are essential for stopping the spread of SARS. As soon as fast DNA-based SARS tests become reliable the industrialized countries should use the tests extensively. At the very minimum, all suspected SARS cases and all their contacts should be tested and tested again. However, even more extensive testing regimes could be imagined. For instance, all people coming from infected areas could be tested or, for even more protection, all people coming into a country from any origin could be tested.
Infected areas that are relatively affluent and capable of carrying out fairly sophisticated measures to control SARS ought to consider testing their entire populations. For instance, Singapore's economic losses from SARS are so large and the benefits of being SARS-free are so large that once cheap and fast SARS tests become available city-state of Singapore ought to consider testing its entire population. Also, if a DNA-based test is not reliable within the first day or two of infection Singapore could consider putting people into quarantine for a day or two upon entrance into Singapore in order to test them again before letting them out into their general population. One way to make such a system workable would be to set aside hotels to use for quarantine and then to make each hotel receive only people who arrive on the same day with a rotating list of hotels looping thru the quarantine cycle.
The Eurasian land mass faces a more difficult task to contain SARS than do places that are geographically isolated with smaller populations. Countries like Taiwan, Australia, or New Zealand ought to be able to totally stamp out SARS and keep it out once fast DNA tests are available. But if SARS becomes established in Central Asia it will be able to jump across borders of impoverished countries and maintain its presence far more easily.
If SARS becomes established in countries that are significant sources of illegal immigrants then attempts to control SARS spread at borders of industrialized countries will become considerably more difficult. A SARS epidemic in Mexico would make SARS control in the United States much more difficult while a SARS epidemic in the Middle East or Africa would pose similar problems for Europe.
See the SARS web sites of the World Health Organization and the US CDC for their latest information.
Update: The more industrialized countries ought to start taking more drastic measures now to help the poorer countries detect SARS sufferers entering their countries. For instance, an effort by the United States to help Mexico and Central American and Caribbean countries to screen international visitors for SARS infection (e.g. by training airport workers, providing thermal imaging machines, and eventually supplying help in testing passengers) will help the to prevent the spread of SARS into the United States. Either that or the United States had better be prepared to deploy troops on a massive scale to keep out illegal aliens coming up from Mexico potentially carrying SARS. That troop deployment may become necessary anyhow. SARS could be spreading in Mexico right now without our even being aware of it.
If the Asian Times staff are right China is already doing triage to decide in what parts of its country it will try the hardest to control SARS. The Chinese government may have already resigned itself to the wide spread of SARS into poor interior provinces and may be focusing its attention on Shanghai and other key trading and commerce cities. The industrialized countries need to start planning how they are going to keep a world SARS pandemic from reaching into their populations and disrupting the industrialized economies.
Update II: Time Magazine has an excellent article that confirms the widely suspected continued cover-up of SARS cases in Shanghai.
A doctor at the Shanghai Contagious Diseases Hospital told TIME that there are more than 30 suspected cases have been admitted to their hospital's facilities, nearly double the official suspected caseload for the whole city.
Basically, local authorities in China still are hiding the truth about SARS. Plus, in the poorer sections of China where SARS is spreading the local authorities will not even have the ability to know for themselves how many SARS sufferers there are. It sure looks like SARS is going to continue to spread thru China and therefore its chances of spreading to other parts of the world are probably increasing. The industrialized countries need to start scaling up to try to halt the spread of SARS into regions ill-equipped to handle it.
Once cheap fast SARS tests become available one great way to slow the spread of SARS would be to require the testing of all passengers on flights everywhere in the world. Also, all people crossing borders by other means should be tested as well.
Update III: The SARS death rate is now thought to be between 8% and 15%.
The research by Professor Roy Anderson, due to be published in a medical journal next week, is expected to say the virus could kill between 8% and 15% - or one in seven - of those infected.
Keep in mind that SARS has a much higher death rate in the elderly. If you are young your own odds of dying from SAR woul be lower than this latest estimate and if you are old your odds would be much higher.
Lawrence Livermore National Laboratory (LLNL) is working on a PDA that can detect nuclear materials.
The device, known as RadNet, is designed to make calls, surf the Web, act as a Personal Digital Assistant, pinpoint locations with Global Positioning System technology and sniff out nuclear materials with a cutting-edge sensor. It is one of several national security projects being worked on at Lawrence Livermore National Laboratory.
The detector may eventually be built into a large assortment of vehicles and it could report detected radiation and a GPS-determined position automatically.
Livermore's Simon Labov, director of the lab's new radiation detection center, sees RadNet phones in the hands of police, firefighters and U.S. Customs agents. One day, though, Labov imagines the gizmos will be built into taxis, rental cars and trucks.
The effect would be to create a large network of roaming sensors over a large area.
“In effect, all of the phones operating at any time are part of one large detector that is spread out throughout an entire geographic area,” Labov explained.
The deployed detectors would all report back to a central database where patterns of radiation changes could be detected and tracked.
With continuous monitoring and data collection, the system can look for patterns of radioactivity in a given area and detect changes that indicate a hazardous condition, he added.
A system of this sort wouldn't require human carriers to be looking at radiation detectors continuously. A microprocessor could automatically continuously read the radiation sensor in each device and it could automatically call in any reading it encountered that was above some threshold level.
Any type of sensor that can be paired with a microprocessor to look for anomalous sensor readings could be deployed in a similar fashion. A variety of chemical and biological agent detectors will surely be developed that can operate for long periods of time without the need to resupply reagents. Then mobile networks of automated biological and chemical terrorism detectors will be deployed along with the nuclear materials detectors.
But there are ways that chemical detectors could be used for more conventional law enforcement purposes. Consider how dogs can detect the smell of a person and track that smell. DNA samples are now widely collected from criminals. If some aspects of a person's scent are stable thru a period of years then it is not hard to imagine that some day scrapings of skin and sweat will be taken from each felon to be analysed to build a chemical signature of that person's scent. Then when chemical sensing technology becomes sufficiently advanced sensors that can detect specific chemical scent signatures could be deployed to continuously analyse the air in public areas. Wanted criminals could be identified by their scent as they pass a public detector. One could easily imagine banks allowing the deployment of such detectors so that the chemical signatures of bank robbers could be recorded along with video recordings.
The Bush Administration is pushing to change federal law to allow permanent retention of DNA samples from those arrested but not necessarily convicted of crimes.
Adding profiles from thousands of adult arrestees and juvenile offenders would greatly expand the DNA system's worth by increasing the number of potential matches, administration officials say. Justice Department officials have discussed potential changes in federal DNA law with key members of Congress and are pushing for legislation this year.
The American Civil Liberties Union (ACLU) is objecting to this proposal. The arguments here are interesting because this is not just an issue of being able to match a person's DNA with DNA that is found to be in some way connected with the commission of a crime. Another issue is that eventually many characteristics of a person will be discovered from analysis of a DNA sample. If genetic variations that cause particular personality types are discovered then a person's DNA could be analysed to see if it has genetic variations that are linked to particular personality and behavioral characteristics.
Governments have many conceivable uses of information about genetically determined characteristics. For instance, if there are genetic variations linked to how well someone can perform as a particular type of soldier then the military might want to look at the DNA profiles of all juvenile offenders (whether they were arrested for drunk driving or assault or just running away from home) to identify promising recruits for special forces. Also, if there are genetic variations that are more or less associated with loyalty and betrayal then intelligence agencies might want to look for recruits who are least likely to betray their country.
Some youthful offenders never commit another crime and some future career criminals are first caught committing a crime that is not particularly serious. Yet if there are genetic variations that make a person more prone to commit crime then someone identified from a first arrest (even if the charges are dropped) as having a DNA profile that matches a career criminal could then be pegged for future surveillance. Prosecutors could conceivably even push for long prison terms for first offenders if their DNA profile matches that of repeat offenders.
Widespread collection of DNA samples can potentially speed the rate of advance of understanding of the human genome. If it becomes legal to do so then as the cost of DNA sequencing falls the DNA samples collected from criminal suspects could be compared on a massive scale in order to discover which genetic variations correlate with which types of behavior. This would greatly help in the identification of genetic variations that contribute to intelligence, personality, and other human characteristics. If basic biometric data is collected (height, eye and hair color, weight, and assorted other measurable characteristics) then additional links between genetics and phenotypic characteristics could be discovered more easily.
The battle over DNA sample collection is just the first round. There will be many more rounds of political battle over what analyses should be allowed to be done to DNA samples in government hands. But the biggest question of all will be over what will be the allowable governmental uses for each DNA analysis.
Governments will not be the only users of DNA analysis results. Insurance companies and other businesses of course could find many applications for such data. However, personal uses of DNA analyses promise to be interesting as well and probably unstoppable.
Police will get powers to obtain and retain the fingerprints and DNA profiles of innocent individuals under proposed laws announced yesterday. A privacy expert with law firm Masons says this means that DNA profiles from nearly half the male population will eventually be contained in the police DNA database – and unless a pending House of Lords decision overrules lower courts, this practice will not breach human rights legislation.
The article on the British proposal brings up an interesting issue: criminals could get DNA samples from innocent people and then deposit such samples at the scenes of crime. This will become easier to do with time as equipment for growing human cells in culture becomes more widely available, cheaper, and easier to operate.
Scientists at Baylor College of Medicine have developed a gene therapy that causes liver cells to convert into insulin producing beta cells which normally are found only in Islets of Langerham in the Pancreas.
HOUSTON (April 21, 2003) – A gene therapy developed by researchers at Baylor College of Medicine has apparently cured diabetes in mice by inducing cells in the liver to become beta cells that produce insulin and three other hormones.
"It's a proof of principle," said Dr. Lawrence Chan, professor of medicine and molecular and cellular biology as well as chief of the division of diabetes, endocrinology and metabolism at the College. "The exciting part of it is that mice with diabetes are 'cured.' "
In the research, which is described in a report in Nature Medicine's online edition today, Chan and his colleagues used the NeuroD gene, a transcription factor that induces the liver to produce cells that make insulin and the three hormones associated with the pancreas' endocrine system.
The gene was attached to a so-called "gutless" adenovirus from which all toxic genes had been removed. This viral vector is a very efficient way to introduce genes into liver cells. Alone, NeuroD partially corrected the disease in the diabetic mice. Combined with a beta cell growth factor called Btc, the gene therapy complete cured the mice's diabetes for at least four months.
An added benefit is that the cells in the liver also produce glucagon, somostatin and pancreatic polypeptide, which may play a role in controlling insulin production and release.
"Until now it has not been possible to induce the formation of islets by any gene therapy approach," said Chan.
It does not mean that the treatment can be used in people immediately.
"It's farther from people than I would like," he said. He knows of no stumbling blocks to its effectiveness in people.
The main stumbling block is the vector or virus used to take the gene into the cells. Chan and his colleagues used the safest viral vector available today, but he expects even safer ones to be available within the decade.
"We want to use the safest vector possible," he said.
The treatment has advantages over transplant of islet cells, the insulin producers in the pancreas, because it avoids the lifelong use of powerful immunosuppressive drugs and eliminates the need to find a compatible donor.
Chan credits one of his postdoctoral students, Dr. Hideto Kojima, with much of the work in developing this protocol.
A UPI article about this report says this treatment does not permanently cure diabetes.
However, this "cure" is temporary and would require repeated injections, researchers point out. Also, just because this worked very well in mice does not guarantee such effects in people. "Unfortunately, it will probably take years," before such a treatment would be available to diabetes patients, Chan said. "Like any other gene therapy, the major concern is safety. People are quite different than mice.
The UPI article is the only article on this story that makes this claim that treatment does not last indefinitely. It seems odd. If cells are induced to differentiate into a different cell type I'd expect the new cell type state to be stable. Also, this treatment has already worked for 4 months in these mice. How long does it take for the treatment to wear off? It is possible that the NeuroD genes added to cells gradually break down and when they stop being expressed then all the downstream effects they cause in the cells stop happening.
Even if the injections had to be periodically repeated they'd still be an enormous boon for sufferers of Type I diabetes. Not only would diabetics be freed from daily injections, blood tests, and carefully regimented diets but they'd also live longer and healthier lives.
In the longer run gene therapies will improve to allow genes to be added to cells in ways that cause those genes to stay around permanently. Ways will be developed to deliver stable plasmids into cells and those stable plasmids will carry the desired genes.
My guess is that within 10 to 15 years type I diabetes will be a curable disease. If the genes used in this latest work have the same effect on human liver cells then the biggest remaining obstacle will be the development of better gene therapy vectors to deliver genes safely into cells. That's a topic that is seeing a great deal of work and it seems reasonable to expect better and safer gene therapy delivery methods will be developed within several years.
Some day in the future diabetics will be able to look at the color of their eye contact lenses in the mirror in order to detect their blood sugar level.
PITTSBURGH, April 14 – Millions of people suffering from diabetes mellitus may be spared the ordeal of pricking their fingers several times a day to test blood sugar levels, thanks to a breakthrough by University of Pittsburgh researchers who have developed a non-invasive method to measure the glucose level in bodily fluids.
Researchers Sanford A. Asher, Ph.D., professor of chemistry in the faculty and College of Arts and Sciences, and David Finegold, M.D., professor of pediatrics in the School of Medicine, created a thin plastic sensor that changes color based on the concentrations of glucose.
The sensor material, which would be worn like a contact lens, was described in a paper published in the online version of Analytical Chemistry on April 11. The paper is scheduled to be published in the print version of Analytical Chemistry, a publication of the American Chemical Society, on May 1.
"There has been a increasing demand for continuous, non-invasive glucose monitoring due to the increasing number of people diagnosed with diabetes mellitus and the recognition that the long-term outcome of these patients can be dramatically improved by careful glucose monitoring and control," said Dr. Asher.
"The current method of testing glucose in diabetes patients-by drawing blood from a finger prick-is uncomfortable and is dependent on patient skill and compliance for regular testing," said Dr. Finegold.
The researchers plan to embed the sensing material into contact lenses worn in the patients' eyes. Patients will determine their glucose levels by looking into a mirror-similar to women's makeup compact mirrors, but with a color chart to indicate glucose concentrations-to compare the color of the sensing material with the chart.
The sensor will change from red, which indicates dangerously low glucose concentrations, to violet, which will indicate dangerously high glucose concentrations. When the glucose level is normal, the sensor will be green. The researchers are still determining the number of detectable gradations, but expect that it may be as high as the finger stick meters currently provide.
The University of Pittsburgh, which owns this patented technology, has licensed this technology to a new startup company that will engineer the material and commercialize it. The researchers believe the product is at least a year from being tested in humans. The researchers expect that their technology would be able to be incorporated into currently available commercial contact lenses, which would be replaced weekly.
This seems like a pretty cool idea. While it is reasonable to expect that cell therapy or gene therapy will provide a cure for diabetes in 10 or 15 years the concept has other potential applications for measuring other body biochemical levels. Imagine a sensor keyed to measuring the severity of some other biochemical problem that could provide an indicator for when to take other drugs. Heck, sensors could be designed to measure the level of a specific drug and if one is taking that drug one could also wear a contact lens designed to detect it. Then one could glance in a mirror to see a color that indicates that one needs to take another pill.
A group of Japanese materials science researchers at Toyota Central Research and Development Laboratories in Nagakute, Japan have used computers to search thru large numbers of combinations of elements to discover alloys with qualities that exceed that of all known alloys.
While any other metal bends or breaks when experiencing forces well below theorized strength limits because of defects in their crystal structure, these new metals approach their ideal strength limits.
"You could not find this alloy just by mixing things and testing. It's just too many combinations -- millions of combinations," Shiflet said.
They have discovered titanium alloys which expand very little over a large temperature range and have other valuable qualities.
The alloys are strong yet unusually elastic, so they can deform more than other alloys and still return to their original shape. Engineers can also readily mold or bend the materials at room temperature into various shapes, a property called superplasticity.
The most interesting thing about this work is that it shows how the pace of material science research is going to accelerate. The ability to use computers in place of lab experiments is made possible by the continuing increase in speed of computers. Computers are getting fast enough to allow complex physical processes to be simulated. This allows the computer modelling of experiments. This ability to simulate physical experiments has the potential to accelerate many fields of science by orders of magnitude.
The fear of Severe Acute Respiratory Syndrome is causing an increasingly panicked response in Beijing China.
At Bank of China branches, there were no lines. The traffic at Western Station, the city's main rail terminal, has dropped 75 percent, to 80,000 passengers a day.
Beijing universities are closing.
More than half of universities in Beijing said they would close indefinitely as the highly infectious disease spreads there.
It is important to remember that the coronavirus that is the probable cause of SARS is nowhere near as easily spread as influenza. Yet, as previous history demonstrates (most notably the 1918 Spanish Flu), very deadly influenza strains can infect the human population. Given that SARS can cause this degree of fear and panic and economic disruption then just imagine the effects on human behavior of an especially deadly influenza epidemic. Countries would close their borders. Cities around the world would become ghost towns. Natural biological phenomena still have the capacity to cause huge changes in the behavior of literally billions of people.
What I'd like to see come out of the SARS epidemic is a wider appreciation of the need to develop better capabilities to respond to natural disease outbreaks in the human population. Much of what needs to be done to prepare for natural disease outbreaks is also is helpful for handling bioterrorism attacks. Better monitoring systems are needed for both natural and man-made disease outbreak scenarios. Faster methods of identification and isolation and characterization of pathogens and faster methods for developing and manufacturing vaccines are all helpful for both types of scenarios. Advances in biotechnology are needed to speed up all the steps of response to a new disease.
Another area that needs to be looked at is how to allow people to carry out more of the normal activities of business and commerce with less exposure to other humans. What simple cheap things can be developed to allow people to move around and do things without coming into as much contact with surfaces other humans have touched or air that other humans have coughed particles into.
I can imagine all sorts of simple and cheap ways to reduce exposures. For instance, how about short sticks to use to press elevator buttons? Or how about more foot operated devices such as restroom soap squirters and water faucet operators so that people don't have to touch surfaces that other people touched?
Another important area that needs work is the development of better facial masks. This is an area that cries out for nanotechnological developments to create material that will filter air more efficiently and last longer. Masks should not become less efficient as they build up moisture from a person's exhalations of breath. Masks should be able to take more particles out of the air with less resistance so that breathing with them is easier.
Singapore is installing thermal imagers to detect elevated body temperatures in arriving passengers.
Airline passengers arriving in Singapore from certain Sars-stricken areas are now being scanned for the disease by a military-grade thermal imaging camera, which will detect any increase in temperature, officials said.
8 units are being installed in Changi airport.
One of the units is currently in use and another eight will be installed by the end of the week, Ong told The Associated Press.
People with hot skin will be looked at more closely by health officials.
Those who show up on the camera screen as “hot bodies,” or with a temperature greater than 37.5 C (99.5 F), will be pulled aside to have their temperature taken by a nurse, said government spokeswoman Evelyn Ong.
Singapore will also deploy thermal imagers to its border checkpoints with Malayasia. Other countries are following Singapore's lead as has been the case throughout the SARS crisis. Hong Kong's airport is also being equipped with thermal imaging to scan passengers.
In Singapore and Hong Kong, airports are being equipped with thermal imaging systems that can pinpoint feverish passengers
Thermal imaging is just one of the technologies being deployed in novel ways to fight the spread of SARS. The Ontario Province of Canada may join Singapore in placing electronic tracking bracelets on people exposed to SARS in order to monitor compliance with quarantine restrictions.
Dr. Young acknowledged the province is giving some consideration to putting electronic bracelets on people reluctant to stay in quarantine, as has been done in Singapore. "We're thinking about that and looking at that," he said. "There may be some legal issues involved."
Thermal imaging and electronic quarantine enforcement are just two of the ways that modern technology is changing how disease outbreaks are fought. The potentially most powerful tool in the modern epidemic fighting arsenal is DNA detection technology placed on DNA chips using low cost mass production. There are promising signs on that front.
Artus Biotech has announced a 2 hour SARS detection assay that detects SARS coronavirus DNA.
Based on the discovered genetic sequence, the BNI has established a real-time PCR (Polymerase Chain Reaction) diagnostic test from which results can be obtained within two hours. From that test, artus developed a ready-to-use system (RealArtTM HPA-Coronavirus RT PCR Reagents) produced under GMP conditions (Good Manufacturing Practice). It will be available from artus and its subsidiaries in the USA and Malaysia from Monday, April 14th, on. Thomas Laue, project manager at artus says: "By providing this assay quickly, we hope to contribute to the standardization of SARS diagnostic worldwide. The early and rapid detection of the virus will be our small share in controlling this epidemic plague." The PCR assay directly detects parts of the new Corona virus in throat swabs, sputum and faecal samples. The RealArtTM HPA-Coronavirus RT PCR Reagents assay delivers results very quickly. The real-time PCR technique improves specificity, allows interpretation of results during the test and provides data about the quantity of the viruses in the sample material. Classical tests like antibody assays in blood allow detection of an infection normally much later, i.e. ten to twenty days after infection. The prompt results of the RealArtTM HPA-Coronavirus RT PCR Reagents assay allows immediate countermeasures by fast diagnosis, e.g. of travellers. By this, the rapid spread of the disease can be prevented.
Hot on the heels of the Artus announcement Singapore's Genome Institute has announced a 3 hour SARS coronavirus detection assay.
The state-run Genome Institute of Singapore said its new test would take three hours and may be sensitive enough to detect the virus in its early stages before a person develops Sars symptoms such as high fever and a dry cough.
How might the SARS outbreak be ended? Picture cheap, fast, and easy-to-use SARS virus detection tests that can detect SARS at a very early stage of infection. Such a test could be employed far more widely than quarantines. Everyone flying from an area where SARS has spread could be tested either before they get on the airplane or shortly after arrival at their destination airport and not released until their test shows a negative result. The same practice could be used at high risk ground border crossings as well. Plus, anyone found by either conventional thermometers or thermal imaging to be running a temperature could be tested and held until the result of the test is known.
If SARS testing could be made incredibly cheap then a more radical approach will become possible: test everyone for SARS. One could just test everyone in countries where SARS is spreading. Or one could, in the extreme, test the whole planet's population. If the testing was done in a relatively short period of time in a geographic area before non-tested people could pass along the virus to tested people then the disease could be eradicated from the human population in the area tested. Then in that area all people who entered could be tested.
Massive testing as a method to control the spread of a disease is easier to do for areas that are geographically isolated. For instance, it would be far easier to do this for Australia or Hawaii than it would be for a country on the Eurasian landmass. It would also be easier to do for areas that, for whatever reason, have little in the way of cross-border traffic.
The speed, cost, and ease of use of a test are not the only elements needed to make massive testing a feasible way to stop a dangerous disease outbreak. Another crucial element is the speed with which the test can be developed in the first place. SARS does not spread as rapidly as influenza and so it has not reached epidemic status in many locations. But the approximately 2 months that it has taken to develop fast tests for SARS (China knew about SARS 5 months ago but kept it secret and so the Western scientists have had only 2 months to identify the cause of the disease and to make tests for it) would be too long of a time for, say, a new and highly deadly influenza strain. However, it seems reasonable to expect that advances in nanopore technology, microfluidics, and other areas of biotechnology and nanotechnology will gradually shrink the amount of time it takes to identify a new pathogen and to sequence it. Once it is sequenced the creation of a new test for it can be done very rapidly.
What we are seeing in the response to the SARS outbreak is the development of elements of the future high tech public health disease fighting arsenal. Automated systems to detect disease and track human movement will only become cheaper and more powerful. Also, many other areas of relevant technology will surely see improvement. The current generation of facial masks will almost certainly be supplanted by greatly improved materials manufactured using nanotechology. The ability to protect a person from exposure will advance in a large variety of other ways including more advanced air filtration systems (again designed using nanotechnology), fancy personal instruments for monitoring individual health, and detection systems for airborne pathogens located in crowded public places. We may some day witness public health officials dispatched rather like police and emergency workers to quarantine an area and its occupants because a detector in some restaurant, airport, or hotel has signalled the presence of a dangerous pathogen.
Ultimately, just as technological advances have accelerated the rate at which diseases can spread other technological advances promise to entirely stop future epidemics at their very start. We may some day live in a future in which natural disease pandemics no longer happen.
You can read more about SARS from a more biological and public health perspective in my FuturePundit Natural Dangers Archive. For economic impacts see the ParaPundit Political Economics Archive. For what the response to SARS says about open versus closed societies see the ParaPundit Open Versus Closed Societies Archive.
Technology review has an interesting article on the work of Japanese researchers to convert natural gas into a solid form to make it easier to transport from small remote fields that would otherwise be too expensive to operate.
Japanese researchers Hajime Kanda and Yasuhara Nakajima at Mitsui Engineering and Shipbuilding in Tokyo think they’ve found a solution with the aid of hydrates, solid crystals in which natural gas—composed chiefly of methane—is caged inside of water molecules.
If the article is correct then currently most of the natural gas in the world is not exploitable because the fields are too small and can't justify the cost of building pipelines to transport the natural gas from them to market. If these Japanese researchers succeed then natural gas could become a much larger percentage of total fossil fuel use.
It is worth having a look at world natural gas reserves. The world total known reserves of oil is 1212.811 billion barrels and for natural gas it is 5,501.424 trillion cubic feet. Saudi Arabia has the biggest oil reserves at 261.800 billion barrels or about 21% of world oil reserves. But Russia has 1680 trillion cubic feet of natural gas or over 30% of world natural gas. Russia has only 60 billion barrels of oil reserves while Saudi Arabia has only 224.7 trillion cubic feet of natural gas.
What we really need to know is how to compare natural gas reserves and oil reserves for energy content. Some handy tables of energy conversion units provide the needed data. 1 cubic foot of natural gas has 0.00102 million btus of energy whereas 1 barrel of oil contains 5.46 million btus. Therefore 5352.94 cubic feet of natural gas have as much energy as 1 barrel of oil. Armed with these conversion factors let's see how do Russia and Saudi Arabia compare.
If these calculations are correct then Russia has more energy than Saudi Arabia and the world has almost as much energy in the form of natural gas energy as it has in the form of oil. While the Middle East has 56% of the world's oil it has only 36% of the world's natural gas. Any technological development that makes it easier to store and transport natural gas will have a large impact on energy markets. Of the fossil fuel energy producers Russia will benefit the most and the world's demand for energy from the Middle East will be reduced.
Carogero Caruso, Professor of Biopathology and Biomedicine at the University of Palermo in Italy, has found a link between high levels of anti-inflammatory cytokine InterLeukin-10 (IL-10) and longevity.
Professor Caruso, whose research is published in this month's Journal of Medical Genetics, said: "Longevity is definitely more easily controlled by those who can counter inflammatory disease."
Long term low grade inflammation has has been linked to the development of a large assortment of degenerative and chronic illnesses. Anti-inflammatory drugs have been found to decrease the incidence of heart disease, cancer (both breast cancer and colon cancer), and other illnesses. Therefore it is not too surprising to find that people who live longer have more anti-inflammatory IL-10 and less inflammation promoting hormone TNFa.
To investigate this further, the research team examined the frequency of genes coding for IL-10 and TNFa in 72 men and 102 women, all of whom had reached the age of 100. Similar DNA testing was also carried out in 115 men and 112 women aged between 22 and 60.
The results showed that significantly more centenarian men expressed genes encoding for high levels of the anti-inflammatory IL-10 than did younger men, although there were no differences in the levels of the pro-inflammatory TNFa among the various age groups.
And significantly more centenarian men expressed genes for the combination of high IL-10 and low TNFa production than did their younger peers. There were no differences in levels of the cytokines, either separately or in combination, among the women.
This latest work builds on previous work by Caruso's group showing that there is a genotypic variation that increases IL-10 production and is associated with longevity.
The presence of -1082GG genotype, suggested to be associated with high IL-10 production, significantly increases the possibility to reach the extreme limit of human lifespan in men. Together with previous data on other polymorphic loci (Tyrosine Hydroxylase, mitochondrial DNA, IL-6, haemochromatosis, IFN-), this finding points out that that gender is a major variable in the genetics of longevity, suggesting that men and women follow different strategies to reach longevity. Concerning the biological significance of this association, we have not searched for functional proves that IL-10 is involved. Thus, we should conclude that our data only suggest that a marker on 1q32 genomic region may be involved in successful ageing in man. However, recent data on IL-6 and IFN- genes suggest that longevity is negatively associated with genotypes coding for a pro-inflammatory profile. Thus, it is intriguing that the possession of -1082G genotype, suggested to be associated with IL-10 high production, is significantly increased in centenarians.
This latest result is another example of how inflammation response affects longevity. Yet another example is the recently discovered link between Parkinson's Disease and COX-2 enzyme levels. Many of the newer non-steroidal anti-inflammatory drugs (NSAIDs), such as Celebrex and Vioxx, work by blocking just the COX-2 enzyme while the older generation NSAIDs inhibit both COX-1 and COX-2 enzymes. It is possible that COX-2 inhibitors may delay the development of Parkinson's Disease. More generally, expect to see a continued stream of reports on the results of studies that investigate how anti-inflammatory hormones and drugs slow or prevent a number of diseases of old age.
As the number of SARS cases in China continues to increase and as SARS shows up in additional parts of China the Chinese leadership has begun to publically acknowledge the seriousness the problem.
Chinese President Hu Jintao admits to being worried about SARS.
"Since the discovery of the SARS cases, I feel very worried. I feel anxious for the masses," Chinese President Hu Jintao said today.
The message from President Hu was broadcast using his own voice to underline the point.
It was his first public comment on SARS and, in an unusual step, the national evening news broadcast his own voice instead of having an announcer read his comments.
Chinese Premier Wen Jiabao says the situation remains grave.
``Much progress has been made in combating the disease, with the epidemic brought under control in some areas, but the overall situation remains grave,'' Mr Wen was quoted as telling a national conference.
These statements are being reported by the Xinhua News Agency and major Chinese newspapers. The Chinese population is still being told that the spread of SARS is being controlled. The official message is still that the government has a handle on the situation. But the problem has gotten large enough and so visible internationally that the Chinese leaders have had to come closer to admitting to their own people the full extent of the problem. It is likely that SARS cases known in Chinese hospitals are still going unreported to the World Health Organization. But it is becoming too hard to cover it up.
Previous official statements that China had SARS under control were scaring away foreign visitors who didn't trust the excessively optimistic picture the Chinese authorities were painting.
Foreign diplomats said the main reason for China's slightly more transparent line on Sars appeared to be a realisation that the previous blithe assurances were scaring more potential foreign visitors than they were reassuring. Mr Wen was now trying a different tack to limit damage to the country's economy.
The official acknowledgement of the scope of the problem may signal that the Chinese authorities are going to try harder to fight the spread of the disease. These comments from top leaders were accompanied by the announcement that China will begin screening rail and aircraft passengers for symptoms of SARS and quarantine suspected SARS cases.
The problem is that China has already lost its best opportunity to control the SARS epidemic before it reached pandemic status. China's best chance was to contain SARS where it started at an early stage. One obvious reason to try to stop a disease at its earliest stage of spread is that the smaller an area it exists in and the fewer infected by it the easier it will be to contain it. But the other less obvious reason is that SARS originated in the Chinese province best equipped medically to contain an epidemic.
Due to its proximity to Hong Kong the Guangdong province of China, the origin of the initial SARS infections, has industrialized much more rapidly than the rest of China. Therefore Guangdong is more affluent and this greater affluence has translated into greater wealth flowing into health care facilities in the province with more hospitals equipped with modern medical equipment, test labs, and drugs. The wealthier hospitals and clinics of Guangdong province have a greater capacity to handle SARS than is the case for the rest of China. Public health experts are quite aware of this situation. In their preliminary report of April 9, 2003 the World Health Organization team in China made note that as SARS spreads from Guangdong into the rest of China it is spreading into areas far less able to handle the disease.
However, the team found an urgent need to improve surveillance in the countryside to head off new outbreaks in rural areas. The team was further concerned by an increase in sporadic cases, which could not be linked to a particular transmission chain, as such cases raised questions about the adequacy of contact tracing. In addition, the report noted many remaining concerns about the ability of other provinces, where health systems are not as strong as the one in Guangdong, to respond promptly and effectively to the challenge of SARS. In Beijing, for example, only a minority of hospitals make daily reports of SARS cases. Contact tracing is another problem in Beijing and does not appear to be carried out systematically. Failure to perform careful contact tracing will allow the disease to spread. The team observed that many of China’s poorer provinces may not have adequate resources, facilities, and equipment to cope with outbreaks of SARS, and underscored that Guangdong’s capacity was exceptional among China’s provinces. In Guangdong, the SARS outbreak placed an enormous strain on the health care system. The Guangdong Infectious Disease Hospital (Guangzhou No. 8 People’s Hospital) had 150 of its 400 beds occupied by SARS patients daily during the second week of February. The team noted that the response of the health care system has been exemplary, and commended the dedication and bravery of doctors, nurses, and others working in clinics and hospitals.
Even wealthier Guangdong's handling of SARS is far from perfect. Poor people infected with SARS are being turned away from Guangdong area hospitals.
The man, who was also exhibiting symptoms of SARS, owed the hospital $250, said Chen's daughter, Chen Lili, who was visiting her father at the time. "They made him pack up and go," she said. "Who knows what happened to him? He had no money and he was sick."
These patients are sent home where they can spread the disease to family members and thereby continue the spread of SARS.
The WHO is worried that SARS may be spreading thru other provinces.
"We're very concerned about what may be happening out in the provinces," Henk Bekedan, director of the W.H.O. office here, said in an interview today.
The April 14, 2003 SARS update from the World Health Organization reporting new SARS cases in the Chinese northern province of Shanxi and in Inner Mongolia. This spread from the south to the very north suggests SARS is probably spreading throughout China.
China has today reported 109 new probable cases of SARS and 6 deaths, bringing the cumulative total to 1418 cases and 64 deaths. The largest number of cases occurred in Shanxi Province, where 47 new cases were reported. In addition, two provinces reported SARS cases for the first time – 10 in Inner Mongolia and 3 in Fujian. The reports indicate that the nationwide surveillance system, recently introduced by Chinese authorities, is working to detect and report cases. However, questions remain about the capacity of some provinces to cope with the challenge of SARS.
Shanxi was instructed only last week to start taking SARS seriously.
Today, officials in Shanxi said the province's local Center for Disease Control was instructed only last week to deal with SARS on an urgent basis. Only three hospitals in the province, all in the capital, Taiyuan, are able to handle SARS patients, officials said.
After 4 people travelling from Inner Mongolia showed up in the country of Mongolia to the north of China the Mongolian authorities responded by cutting off air and rail links to Inner Mongolian capital Hohhot.
The government said in a statement it had cut air and rail links to Hohhot for 14 days after four people with symptoms of the disease arrived from the capital of China's Inner Mongolia region, where three people have died of SARS.
Does anyone think there is the slightest chance that Mongolia and Inner Mongolia have the capacity to deal with SARS? This disease looks set to spread throughout the poorest parts of Asia. Now it is time to start looking for reports of SARS in Central Asia. Russia ought to start checking all rail and air passengers coming into Russia from China and Mongolia and ought to start checking those headed westward. But given how far SARS has already spread in China it seems only a matter of time before the disease spreads westward across China and into Tajikistan, Uzbekistan, and other countries in that region.
In spite of all this do you still feel optimistic that the spread of SARS can be halted? Well, South Africa wants rich Chinese tourists so much that it continues to encourage them to visit South African and it will not even screen them as they enter the country for signs of SARS.
Beijing - South Africa wooed Chinese tourists on Monday, saying they will not be barred from the country or subject to screening despite the spread of the deadly severe acute respiratory syndrome, or SARS, virus.
Picture SARS getting established in Africa spreading thru large populations of HIV sufferers with weakened immune systems. The lackadaisical South African government attitude toward SARS is grossly irresponsible.
The April 14, 2003 SARS update from the World Health Organization shows Hong Kong and China have 80 percent of all known SARS cases to date.
As of today, a cumulative total of 3169 cases of SARS, with 144 deaths, have been reported to WHO from 21 countries. This represents an increase of 213 cases and 25 deaths since the last update on Saturday. Indonesia, the Philippines, and Sweden report their first probable cases (1 in each country) today. Japan, which had previously reported four probable cases, was removed from the list as these cases were determined to have other causes. China, with 1418 cases and 64 deaths, remains the most seriously affected area. Hong Kong SAR, with 1190 cases and 47 deaths, is the second most seriously affected area. Three of the deaths in Hong Kong over the weekend occurred in persons under the age of 50, marking a departure from a previously pattern in which SARS caused deaths primarily in the elderly or in persons with pre-existing disease.
My guess is that China's SARS spread will accelerate while Hong Kong might be able to get it under control. The events in China may presage what will eventually happen in India, Africa, and other impoverished locales. If it gains a foothold outside of China in a poor country then SARS is very likely to become a pandemic.
One thing that Chinese health authorities ought to consider doing is to identify all people who have been exposed to and recovered from SARS. Then recruit those people to become health care workers to take care of SARS patients. Many of those who were infected with SARS in the first place were health care workers. So they already possess the needed skills. But the other recovered SARS patients could be trained in simple medical skills and work under the supervision of more skilled people who could tell them what to do.
A German biotech company has released the first SARS test which is based on the assumption that SARS is caused by a coronavirus.
The full coronavirus sequence will allow the development of faster, more accurate tests for SARS, using specific viral DNA fragments to prime PCR reactions. Early sequencing by the Bernhard Nocht Institute in Hamburg, Germany, has already helped the German firm Artus to produce a test that goes on sale on Monday.
The new Artus test takes only 2 hours.
The test can detect the virus from throat swabs, sputum or feces and produces results in two hours, say its makers, who specialize in disease test kits. They said classical tests for antibodies typically took 10 to 20 days after infection.
A HAMBURG BIOTECH company will release a real time PCR (polymerase chain reaction) diagnostic test on Monday which, it is claimed, can diagnose SARS (severe acute respiratory syndrom) in two hours.
What is good about a PCR-based DNA test is that it can detect a SARS infection at a far earlier stage than an antibody-based test. Therefore this Artus test is very good news.
A cheap fast SARS virus DNA detection test has the potential to at least keep SARS from becoming a big presence in the industrialized countries. The SARS virus might achieve pandemic status worldwide and yet the industrialized countries could mount a vigorous long term defense using testing to keep SARS from becoming established in the industrialized countries. Testing could be done to all people entering industrialized countries thru legal ports of entry to identify people who need to be sent into quarantine. People could be held in customs until their tests were completed. Also, anyone showing SARS symptoms or exposed to someone with SARS could be quickly tested. However, illegal immigrants would still serve as carriers of SARS into industrialized countries. Also, there would still be false negative test results among those at the earliest stages of infection. Plus, all tests have error rates. Still, widespread testing could limit the presence of SARS in the industrialized countries until a vaccine becomes available.
Daniel MT Fessler, an anthropologist at UCLA, argues that hormones decrease interest in food in human women and a large variety of other animal species during the period of ovulation.
During this ovulatory period, a California anthropologist now finds, women naturally and unwittingly eat some 5 to 25 percent less than at other times.
The purpose of the decrease in appetite is to cause femals to spend less time searching for and consuming food in order to free up more time for mating.
Women's bodies must be telling them to give less attention to food and more attention to sex during the time each month when they could become pregnant.
Fessler speculates that the mechanism of action is that higher blood estrogen potentiates the effect of the hormone cholecystokinin. Cholecystokinin is believed to play a role in inducing satiety and is released by the small intestine after meals.
You can read the abstract of the paper from The Quarterly Review of Biology.
Evolutionary psychology grew out of sociobiology and, like its predecessor, is based on the assumption that human behavior has been importantly shaped by natural and sexual selection. However, evolutionary psychology differs from sociobiology in a number of fundamental ways. While sociobiology is content to treat the mind as a black box, evolutionary psychology asserts that because behavior is a product of mind, in order to shape behavior selective forces must have shaped the mind. Moreover, because selective forces are highly specific, the mind ought to consist of multiple independent systems, each a response to a particular selective force. Lastly, because foraging in small groups probably constituted the principal adaptation throughout most of hominid evolution, selection will have operated to maximize fitness within this social and physical context.
Human minds are thus seen as a package of proclivities and capacities, each of which served a specific function in our foraging past.
Fessler has additional information about his areas of research on his UCLA web site.