Archive for the ‘Human Biology’ Category
Smallpox was eradicated completely in 1980. The only known stocks of the virus that causes smallpox are in carefully guarded laboratories in the U.S. and Russia. Nevertheless, the U.S. government is spending nearly $500 million for about two million doses of smallpox vaccine, according to a recent article in the New York Times.
Does this make sense? Well, yes and no. No one knows for sure whether there are unreported stocks of the virus somewhere, and if there are, whether they might fall into the wrong hands. Apparently the U.S. government thinks that it would be prudent to have a stock of smallpox vaccine on hand, just in case the smallpox virus is used someday in a bioterrorism attack.
Only time will tell whether stockpiling smallpox vaccine will prove to be a $500 million waste of money or a lifesaver. But while you’re considering whether you think it’s a good idea, consider this; if there is an outbreak of smallpox some day, who will be able to get the vaccine? Two million doses wouldn’t cover even a quarter of the population of New York City alone. How much of this vaccine should we be stockpiling?Source:
Fertility clinics have a new tool for monitoring the early development of fertilized eggs into blastocysts/embryos, before a decision has to be made regarding which embryos(s) to implant in the woman. It’s called the Embryoscope Time-lapse embryo monitoring System, or just the Embryoscope for short. The Embryoscope is an incubation chamber with a built-in time-lapse microscopy and data recording system that can incubate and monitor up to 72 embryos at a time. Because the embryos do not need to be removed repeatedly from the incubation chamber to be examined, the risk of damaging the developing embryo is reduced. In addition, the operator can review the entire dynamic sequence of cell divisions of the embryo rather than just selected snapshots in time. (For a time-lapse view of embryonic development, see the NBC news report on the Embryoscope) Time-lapse microscopy allows the operator to assess the precise timing of each cell division and whether or not the cell divisions are synchronous. (Do the first two cells divide into four at the same time?) And because the data are stored digitally, the operator need not be physically present at precisely 12 hours, for example, to be able to assess embryonic development at the 12-hour stage.
The Embryoscope should markedly increase efficiency in the fertility clinic. It should also help health professionals decide which embryos are the best candidates for implantation. It is not known how many fertility clinics are already using the Embryoscope, but I expect the number to increase.Source:
What is the “standard of identity” for milk? This may sound like a silly question, but condensed milk, evaporated milk, and milk all have very specific specifications, as defined by the FDA. The FDA keeps close watch on such things to prevent food manufacturers from misrepresenting their products.
The FDA revealed last week that it is considering a petition from the dairy industry for a rule change that would allow milk to be sweetened with “any safe and suitable sweetener”, such as aspartame. Furthermore, the dairy industry wants the sweetened milk to be called just milk, without having to reveal on the front of the container that it contains sweeteners. The industry is worried about flagging sales of plain old boring milk, and they’ve come up with a marketing solution – make it taste sweeter!
To convince the FDA that this would be a good thing, the dairy industry makes the argument that making milk taste sweeter will allow it to compete more effectively with sugary drinks. The industry’s logic is that if milk tasted sweeter, more kids might choose milk it over sugary drinks. And that, they say, would help combat obesity.
Huh? Getting kids used to sweeter-tasting milk (and thus to sweet-tasting drinks) will somehow reduce their preference for sugary foods and drinks and combat obesity? You’ve got to be kidding. The industry’s petition to the FDA has prompted an angry response from parents and consumer groups. The FDA is inviting public comments on the issue through May 21, 2013, after which it will make its decision. If you have an opinion, you can register it on the FDA’s website.Source:
The first adult animal to be cloned was Dolly the sheep. At the time (1997) the event was seen as a remarkable technological feat, of importance primarily to research biologists. In the decade that followed other animals were cloned in research laboratories around the world. Initial success rates were low, but in recent years the techniques have improved to the point that the cloning of adult animals is becoming economically feasible.
For example, a Texas company called Crestview Genetics is now in the business of cloning polo ponies. Polo is a big sport in many countries, and good polo ponies are in great demand. According to an article a polo trade journal, a three-month-old clone of a polo pony called Cuartetera sold for $800,000 in Argentina in 2010. Crestview expects to be able to create up to 30 clones of valuable polo ponies and horses a year. You do the math.
Cloning animals for a profit is likely to become even more commonplace within the next decade. The most likely candidates, obviously, are animals that are worth a lot to somebody, like prizewinning bulls for breeding cattle; championship dogs; rare or endangered animals; even beloved pets. How much would you be willing to pay to have your pet cloned?Source:
Persons with potentially life-threatening allergic reactions to specific allergens (such as bee stings or certain foods) are told to carry an epinephrine auto-injector with them at all times. A typical epinephrine auto-injector (such as an EpiPen) is a device about 5 ½ inches in length by one inch in diameter containing a single dose of injectable epinephrine. When an allergic reaction occurs, the user is supposed to inject the epinephrine into his/her thigh as soon as possible. I carried an EpiPen myself for a time, after I suffered a severe allergic reaction to multiple stings by ground-dwelling yellow jacket wasps. But as time went by I stopped carrying it because it just didn’t seem necessary, and because carrying it every day was inconvenient. Fortunately, I’ve never had another severe allergic reaction like that first one. But what if I did?
Now there’s an alternative, called Auvi-Q. Auvi-Q is still just a single dose of injectable epinephrine. But Auvi-Q is shaped entirely differently; it’s about the length and width of a credit card and the width of a smart-phone. The manufacturer hopes that it will appeal to the younger generation used to carrying credit/debit cards and phones. More importantly, once the cover is removed Auvi-Q talks the user through the entire process of injection with a soothing human voice. (To hear the instructions, view the video on the Auvi-Q website.) The verbal instructions may be helpful to some users and caregivers, since it may be years before the device is needed and one could forget how to use the device in that time.
The maker of Auvi-Q hopes that younger persons will find the device “cool”, and so perhaps they’ll be more willing to carry it than the EpiPen. (The manufacturer of the EpiPen takes issue with an Auvi-Q marketing claim that 2/3 of EpiPen users don’t actually carry their EpiPen with them.) Time will tell whether Auvi-Q is different enough to find a place in the competitive epinephrine auto-injector market.
Injectable anabolic steroids are drugs. Yes, they are legal, but only when they are prescribed by a physician. It is standard medical practice for the physician to meet with the patient and make a determination that the use of an anabolic steroid is justified before prescribing it.
But wait a minute – aren’t anabolic steroids readily available by mail order and even over the Internet? Well, yes, but that doesn’t make it legal – it just means that the authorities haven’t caught up with the sellers (or the buyers!) yet. A few states are beginning to crack down on the illegal sales of anabolic steroids in the most egregious cases, but frankly they seem to be swimming against the tide.
Case in point; in 2007 prosecutors from Albany County in the state of New York, backed by federal authorities and officials in Florida, charged six doctors in Florida with writing prescriptions for controlled substances to patients they had never met. It isn’t clear whether the doctors lost their licenses as a result. And just this month, according to a story in the New York Times, the Florida pharmacy linked to the doctors pled guilty to the illegal online sale of steroids and paid a fine of $100,000.
A fine of $100,000 doesn’t sound like much, especially since a guilty plea allowed the former owners of the pharmacy to avoid criminal charges. Perhaps this is why the sale of anabolic steroids over the Internet continues almost unabated. There’s money to be made, the sellers rarely get caught, and even when they do the punishment seems fairly minor.Source:
Most health experts agree that the best milk for human babies is mother’s milk. Human milk provides the ideal nutritional mix for the infant. It also partially protects babies from colds and infections early in life (when their own immune system is still immature) because it contains some of the same antibodies that are present in the mother. These antibodies are not present in cow’s milk.
Unfortunately, some parents are not able to provide their infants with the infant’s mother’s own milk. Gay couples, for example, and women who are unable to nurse will need another source of human milk. Some parents find their own donors or rely on websites like Eats on Feets and Human Milk 4 Human Babies; others use established human milk banks such as those affiliated with the Human Milk Banking Association of North America. The established milk banks alone dispense several millions of ounces of human milk every year; how much is exchanged privately or as a result of contact between strangers over the Internet is unknown.
Purchasers of human milk should be aware that human milk can contain harmful bacteria, or viruses such as H.I.V. It may also contain certain drugs taken by the human milk donor. The established milk banks routinely screen their donors and pasteurize the milk before selling it, but not all private exchanges do. Unpasteurized human milk from an unknown source represents a risk. It’s is up to the purchaser to decide on how great that risk is.Source:
In recent years there has been a sharp increase in the public’s awareness of the potential for traumatic brain injury in certain contact sports. Unfortunately, not much is known yet about acute traumatic brain injury. In order to protect athletes more effectively we need to know a lot more, starting with accurate diagnosis.
Fortunately, progress may come soon. Starting next month, the NFL will partner with General Electric in a $30 million effort to learn how to diagnose and track the time course of traumatic brain injury, according to an article in the New York Times and on the NFL’s website. GE will focus on the development, refinement, and validation of imaging techniques such as Positron Emission Tomography (PET) and Magnetic Resonance Imaging (MRI). MRI is already being used to study multiple sclerosis and Alzheimer’s disease, but its usefulness in diagnosing head injury has not been proven. The goal would be to be able to diagnose and quantify the extent of an acute brain injury quickly and then to track the time course of recovery, so that better decisions could be made regarding when an athlete could safely return to the field of play. Imaging techniques might also be used to accurately diagnose chronic traumatic brain disease. The NFL and GE expect their joint effort to show significant progress within 4 years.
The ability to diagnose and track the extent of brain injury would be useful beyond sports, of course. Many soldiers have suffered acute traumatic brain injury during combat, and traumatic brain injury is a leading cause of death among children and young adults.Source:
Some patients suffer from nearly constant intense pain. Pain management is complex enough that it has become a true medical specialty. Years of medical specialty training are required, culminating in certification by the American Board of Pain Medicine. Management of chronic pain requires a multi-faceted approach that includes careful medical evaluation after referral by a licensed physician; a full understanding of the source of the pain; attempts to reduce pain by non-narcotic means; and when all else fails, minimal doses of pain medications dispensed under strict medical supervision. Patients generally have insurance coverage because their pain has been properly diagnosed and is being legitimately treated.
Unfortunately, certain legitimate pain medications are also popular street drugs. And that has given rise to “pill mills” – medical clinics masquerading as pain management centers that are in reality just high-profit pain medication dispensaries. At pill mills, patients are prescribed unusually large doses of narcotics such as oxycodone, generally for cash and generally without extensive diagnosis or alternative treatment. Many of these pills are later sold for cash on the black market, rather than being used by the “patients” themselves.
According to the Wall Street Journal, the state of Georgia has developed a “pill mill” problem in the wake of an aggressive crackdown on such clinics in Florida. The clinics simply moved north, where current Georgia laws make it hard to prosecute such clinics effectively. Georgia, like most states, does not require medical clinics to be owned by a medical professional and does not track the number of prescriptions each clinic writes.
The state of Georgia will surely do something about its pill mill problem in due time. But until there’s a national solution or at least communication and coordination among the states, the pill mills are likely to just move elsewhere.
Women sometimes develop blood clots in their veins (venous thromboembolism) or pulmonary arteries (pulmonary embolism) during pregnancy. The development of blood clots during normal pregnancy is a rare event, but when it occurs but it can be potentially serious.
Women who are contemplating IVF (in vitro fertilization) should be aware that according to a recent report, the risks of developing venous blood clots during an IVF-induced pregnancy are about 77% higher than during a normal pregnancy. The risk is especially increased during the first trimester. However, the absolute risk is still fairly low; about 4.2 cases per 1,000 pregnancies. It’s nothing to worry about unduly, but perhaps it’s something that should be discussed with one’s doctor before undergoing IVF.
The authors hypothesize that perhaps the reason for the increased risk is that high doses of estrogen generally are used to stimulate egg development prior to egg collection in an IVF procedure. Exogenous estrogen (in birth control pills or in hormone replacement therapies after menopause) is known to be associated with venous thromboembolism. This raises an interesting untested question – would women who undergo an IVF procedure but who do not become pregnant also be at increased risk for blood clots? As far as I know, that has never been tested.Source:
Many women who are diagnosed with breast cancer in one breast are opting to have the other breast removed as well. The surgery is called contralateral prophylactic mastectomy, or CPM. According to a recent report, four years after a diagnosis of breast cancer 30% of women were considering undergoing CPM, and 7% had already done so.
Is CPM justified in most cases of unilateral breast cancer, or are women’s fears and anxieties leading to over-treatment? Apparently, most of the women who opted for removal of their contralateral breast after a diagnosis of breast cancer had not undergone any genetic testing or counseling and were not actually at increased risk for cancer of the contralateral breast.
Why are women opting for CPM when it may not be medically necessary? One reason is that women who have had breast cancer tend to substantially overestimate their risk of developing cancer in the contralateral breast, according to researchers at the University of Minnesota. These findings suggest that more counseling is needed, so at least women who opt for CPM do so with correct information.
No one knows whether accurate information regarding breast cancer risk would lower the rate of voluntary CPM among women diagnosed with breast cancer in one breast. After all, who can estimate the value of peace of mind? In the end, it has to be the woman’s choice.Source:
Exercising immediately after receiving a flu vaccine enhances the effectiveness of the vaccine, according to researchers at Iowa State University. In the study, young adults who received the flu vaccine either participated in a mild-to-moderate exercise regimen for 90 minutes immediately after receiving the vaccine, or remained sedentary for 90 minutes. Participants who exercised immediately after receiving the vaccine showed a greater level of antibody production than students who remained sedentary. Presumably the higher level of antibody production would better protect the participants who exercised against the flu, but apparently that wasn’t specifically tested in this study. (The study has not yet been published in a peer-reviewed journal.)
The mechanism whereby exercise enhances the effectiveness of the flu vaccine isn’t known yet. The study’s lead researcher speculates that by improving blood flow to some tissues, exercise may speed the delivery of the vaccine to the lymph nodes, where most antibody production takes place. But that remains to be tested.
So go ahead and exercise immediately after the flu shot if you want to: it appears to do more good than harm.Source:
One of the defining features of humans is that the shape of our hands and fingers allows us to touch the tips of our fingers with our thumbs. As a result, we are able to pick up and manipulate very small objects – something other primates can’t do. Textbooks describe this human anatomical feature as having “opposable thumbs”. Allegedly it is a feature that has given us an evolutionary advantage.
Now researchers report that there’s another unique feature of the human hand that also confers an evolutionary advantage. According to a recent paper published in the Journal of Experimental Biology, the structural arrangement of the bones in the hand and the wrist allow us to make a very effective fist, for use as a weapon. The report demonstrates rather convincingly that when we curl the four fingers into the palm and then position the thumb over the index and second finger, the unique shape of the human fist allows the palm to buttress and support the fingers when we strike a blow. As a result, more force is transmitted by the knuckles than would be possible with the hand anatomy of other primates.
The authors of the study suggest that being able to use the fist as a weapon confers an evolutionary advantage. In other words, our hand evolved not only to be able to manipulate small objects easily, but also to fight effectively.Source:
Until the very end of 2012, industry experts were predicting that the construction of new wind turbines for generating electricity would decline by as much as 90 percent in 2013. That was because a tax credit amounting to about $1 million dollars per windmill was set to expire on Dec. 31, 2012. Wind turbine developers rushed a lot of new wind turbines into production in 2012 in order to take advantage of the credit, but had essentially no plans for new construction in 2013. Had the tax credit actually expired, more than 30,000 jobs might have been lost in the industry.
But the industry got a last-minute reprieve as part of the fiscal cliff negotiations in the final days of 2012. Part of the tax package included in the final fiscal cliff deal was an extension of the tax credit for wind turbine construction that begins in 2013, provided that construction is completed by 2014. That gives the industry some breathing room, at least for now.
Federal tax credits are sometimes used to encourage the development of new industries that may not yet be cost-effective. The wind turbine industry has been granted tax credits three times since 1990. This time around, concerns over the national debt mean that there is likely to be very little enthusiasm in Congress for extending the subsidy (amounting to over a billion dollars a year) yet again after this one expires.
Currently, wind energy accounts for 23 percent of all electricity generated from renewable resources, according to government statistics. The other renewable energy sources are hydropower (63%), wood and biomass waste (11%), geothermal (3%), and solar.Source:
Is it okay for pregnant women to get a flu shot? The answer is “yes”, according to a study conducted in Norway recently. (The research was conducted in Norway because access to health care in Norway is nearly universal, and good records are kept.) The results of the study are published in the New England Journal of Medicine.
The researchers reviewed the outcomes of the pregnancies of over 100,000 women in Norway during 2009 and 2010, about half of whom received the flu vaccine during the second or third trimester (the other half served as the control group). As expected, vaccination during pregnancy reduced the risk of getting the flu by about 70% compared to the control group. Vaccination during pregnancy also appeared to reduce the risk of fetal death slightly, but the reduction was not statistically significant.
Pregnant women tend to suffer more complications of the flu than non-pregnant women, in part because their immune systems are partially suppressed during pregnancy. So it’s important that they understand that they can get a flu shot without harming their babies. In fact, the flu vaccine may be good for the fetus/newborn as well as good for the mother; antibodies produced by the mother can cross the placenta (protecting the fetus) and are found in the mother’s milk (protecting the newborn for up to six months).Source:
In 2009 a study from Canada reported that slightly overweight people actually were at less risk of dying than people of normal weight (see this blog, July 9, 2009). That study generated a lot of controversy, understandably. One criticism was that the study included “only” 11,000 people, all of whom were Canadians; perhaps the results would not be not be generalizable to other populations.
Now a subsequent much larger study proves the Canadian study right. The most recent study is a meta-analysis of 97 separate studies of weight versus mortality that includes over 2.9 million people. The results show quite convincingly that people who were “overweight” by current government definitions (a Body Mass Index of 25-29.9) were 6 percent less likely to die over a given time period than persons of “normal” weight (BMI 18.5-24.9).
No one is suggesting that people should gain weight just to live longer. For one thing, mortality risk goes up dramatically for persons who are severely or morbidly obese. But the data do call into question the proper definition of “normal” or ideal weight. Perhaps the definitions of normal weight, overweight, and obesity need to be shifted ever-so-slightly to the right, towards slightly higher BMIs.
We may never have a true definition of “ideal” weight, because any such definition would probably have to take into account a whole host of other factors such as physical health and even happiness. But the current data does give one food for thought when it comes to understanding the meaning and value of government definitions of ideal weights.Source:
Whose fault was it that several batches of compounded drugs produced by a compounding pharmacy in Massachusetts led to hundreds of cases of fungal meningitis and 32 deaths in 19 states? Predictably, we’re now at the “blame-game” stage. According to The Examiner, fingers are being pointed at the compounding pharmacy (for bad manufacturing practices); the Massachusetts state pharmacy board (responsible for oversight of the compounding pharmacy); poor communication between states; the FDA (for not fulfilling its mandate from Congress to “protect the public health”); even Congress itself (for enacting the laws under which the FDA operates).
Hopefully the various players will get beyond the blame game and come up with concrete solutions. This tragedy should be a wake-up call for regulators at all levels. We’ll be watching to see what (if anything) changes in the future.Source:
According to the Centers for Disease Control (CDC), 25% of people who are infected with HIV do not know they are infected. Apparently these people are causing 80% of all new HIV infections. The available research suggests that if they knew they were infected they would make healthier choices in order to maintain their own health and protect the health of those they love. In the long run, that would reduce the rate of new HIV infections and ultimately lower our national health care costs.
At least that’s the logic behind the idea that all adults should routinely be tested for HIV infection. The American College of Physicians and Surgeons currently recommends that all persons older than 13 years should be tested. The CDC largely agrees, but adds that testing is not warranted in persons older than 64 or in populations with an HIV prevalence of less than 0.1%. However, the U.S. Preventive Services Task Force (USPSTF) does not yet recommend routine HIV screening of all persons; it recommends screening only patients “at increased risk”. As a result, routine screening for HIV infection is not yet commonplace. It boils down to money; without a recommendation by the USPSTF, insurance companies are unlikely to pay for HIV tests in healthy people.
Physicians groups and the CDC argue that patients don’t necessarily tell their physicians if they are at increased risk of HIV infection, so it’s nearly impossible to tell who is at increased risk. In addition, it’s hard for a physician to know the actual percentage of HIV in the patient’s population.
But now it appears that the USPSTF is considering changing its recommendation. The Task Force issued a draft document on Nov. 20 that, if approved, will recommend that all persons aged 15-65 be routinely screened for HIV infection. The draft document is available for public comment until Dec. 17.
Would routine screening for HIV infection be a good idea? You decide. You can comment on the USPSTF’s draft recommendation if you wish by going to to the USPSTF’s web page on the subject.
The evidence that there is a link between repetitive mild traumatic brain injury and a degenerative brain disease called chronic traumatic encephalopathy (CTE) continues to build. In the most recent study, published in the journal Brain, evidence of CTE was found in the brains of 68 of 85 subjects with a history of mild traumatic brain injury, including 34 of 35 NFL players and four out of five hockey players. In contrast, there was no evidence of CTE in the brains of 18 normal control subjects.
These new data should not be taken to mean that nearly all NFL players and hockey players are destined to develop CTE. It’s important to recognize that the subjects who were chosen for inclusion in the study were chosen specifically because they had been exposed to repetitive mild brain injury during their careers. Nevertheless, the numbers are pretty shocking. No one is suggesting that we give up sports such as football and hockey. But as the dangers of repetitive brain injury become more and more apparent, sports federations and professional sports leagues will need to look closely at how to protect athletes from these kinds of injuries.
A committee of the prestigious American College of Obstetrics and Gynecology (ACOG) issued a recommendation recently that oral contraceptives be made available over-the-counter (OTC). Currently, oral contraceptives are available only by prescription.
Some obstetricians and gynecologists benefit financially from the current prescription-only policy. Nevertheless, ACOG is advocating for OTC availability because it believes that the increased availability of oral contraceptives would go a long way toward reducing the high incidence of unwanted pregnancies in this country. The economic and social costs of unwanted pregnancies include costs for health care; costs associated with social welfare support for poor women and their infants; even the social costs of higher levels of domestic violence in families with unwanted children. According to ACOG, the added risks if oral contraceptives were available OTC would be minimal.
ACOG can only recommend, however. The FDA would have to approve the OTC sales of oral contraceptives, and so far, oral contraceptive manufacturers have not even applied for such approval. Perhaps with this recommendation they’ll be temped to do so.
Even if OTC sales of oral contraceptives are eventually approved, an age restriction could still apply, as it does for the “morning-after” pill (You must be 17 or older to purchase the morning-after pill over-the-counter.)
As I predicted on this blog on Oct. 9, a recent outbreak of fungal meningitis has led to a renewed call for FDA regulatory authority over the burgeoning drug compounding industry. As you may recall, the outbreak was traced to bad batches of a steroid that had been packaged by a drug compounding company in Massachusetts. So far 461 people have been infected and 32 persons have died, according to the CDC.
Drug compounding used to be done by neighborhood pharmacies on a limited basis, primarily for local doctors and patients. Traditionally, pharmacies are regulated by the individual states. But with the rise of the Internet and of large health care systems and hospital chains, compounding pharmacies have become highly specialized, high-volume facilities that sell their products nationwide. And yet like all pharmacies, compounding facilities are still regulated primarily by the pharmacy boards of individual states.
This week the commissioner of the FDA appeared before a congressional committee to ask for increased authority to monitor and regulate compounding pharmacies. According to the commissioner, compounding pharmacies are not even required to give the FDA access to their books, for example. Surprisingly (or perhaps not so surprisingly!) the congressional committee seems to be split along party lines, with republicans arguing that the FDA already has enough authority to regulate compounding pharmacies and democrats arguing that the FDA should be given more regulatory authority. We’ll be watching this one.
As you may know, 37 of our roughly 22,000 genes are located within mitochondria, rather than in the nucleus. Consequently these 37 genes are inherited entirely from the mother, since the female provides the egg (with its haploid number of chromosomes) and all of the egg’s organelles including the mitochondria. The male provides a haploid number of nuclear chromosomes.
A few inherited diseases are due to defects in those 37 mitochondrial genes. In fact the chance is about 1 in 4,000 that a child will develop a mitochondrial-based disease. Researchers think that these diseases could be among the first heritable diseases that could be permanently cured, according to a news report in Nature. How? The potential mother (with the mitochondrial-based genetic disease) and a healthy female donor would each provide an egg. The nucleus of the potential mother’s egg would be removed and inserted into the healthy mother’s enucleated egg. The egg would be fertilized by the potential father’s sperm, allowed to develop into a zygote (an early stage of development), and then inserted into the potential mother for development.
The child would have genes from two women, of course, but not very many from the donor woman – only 37 out of 22,000. And the child and all of its future descendants would be forever free of the disease.
So far, this has not yet been attempted beyond the zygote development stage. For one, genetically engineering a child is currently illegal. For another, the researchers who carried out the experiment to the zygote stage found a disturbing number of abnormalities in the zygotes they created. The researchers believe, however, that with further experimentation these problems could be overcome. The fact that we’re so close to curing a whole class of heritable diseases is likely to stimulate debate over whether such experiments should ever be conducted.
The first in-home HIV test kit became available last month in retail stores nationwide. The test kit, called OraQuick, was approved by the FDA in July, but it took until October to ramp up production and launch a nationwide sales effort.
The kit is designed to test a sample of oral fluid for antibodies to HIV in under 45 minutes. The kit has a reported false positive rate (identifying a person as HIV-infected when in fact he/she is not) of only 0.02%, or 1 in 5,000 persons. However, it has a false negative rate (failure to identify an HIV-infected person as infected) of 8%, meaning that HIV infection will be missed in 1 in 12 infected persons. The reason for the higher false negative rate is because the test detects the human antibodies that develop in response to HIV infection, not the HIV virus itself, and it takes several months after initial infection for these antibodies to develop.
A similar test has been available in doctors’ offices for some time. Nevertheless, health officials are hailing the home test as an important step forward in the fight against HIV-AIDS. The hope is that the availability of an inexpensive home test will encourage more people to test themselves for HIV infection, and then to seek treatment if they test positive.
Analysis of the partial skeleton of “Lucy”, the best-known skeleton of Australopithecus afarensis discovered in 1974, revealed that the species was capable of standing and walking upright. Many scientists presumed, based on the probable shape of her shoulder bones (some bones were missing) that she also still climbed trees, like her ancestors. Others disagreed, arguing that the shape of her shoulder was just a vestigial retention from her ancestry, no longer of any real functional value.
To resolve this issue, researchers compared the anatomy of the scapula bone of a partial skeleton of a recently-discovered juvenile A. afarensis to the growth patterns of scapula bones of humans and modern apes. They concluded that A. afarensis, like modern apes, used its upper limbs to climb and move through trees, at least part of the time. Perhaps they slept in trees as a protective strategy, or climbed trees to harvest food.
The unique shoulder anatomy that permits overhead use of the upper limbs to climb and swing from trees disappeared in Homo erectus, a later transitional species in the human lineage.