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Comment by Dr. Krishna Kumari Challa on March 11, 2015 at 9:44am

Blood group O protects against malaria- here is how:

It has long been known that people with blood type O are protected from dying of severe malaria. In a study published in Nature Medicine, a team of Scandinavian scientists explains the mechanisms behind the protection that blood type O provides, and suggest that the selective pressure imposed by malaria may contribute to the variable global distribution of ABO blood groups in the human population.

It has long been known that people with blood type O are protected against severe malaria, while those with other types, such as A, often fall into a coma and die. Unpacking the mechanisms behind this has been one of the main goals of malaria research.

A team of scientists led from Karolinska Institutet in Sweden have now identified a new and important piece of the puzzle by describing the key part played by the RIFIN protein. Using data from different kinds of experiment on cell cultures and animals, they show how the Plasmodium falciparum parasite secretes RIFIN, and how the protein makes its way to the surface of the blood cell, where it acts like glue. The team also demonstrates how it bonds strongly with the surface of type A blood cells, but only weakly to type O.

Principal investigator Mats Wahlgren, a Professor at Karolinska Institutet’s Department of Microbiology, Tumour and Cell Biology, describes the finding as “conceptually simple”. However, since RIFIN is found in many different variants, it has taken the research team a lot of time to isolate exactly which variant is responsible for this mechanism.

The mechanism behind the protection that blood group O provides against severe malaria, which can, in turn, explain why the blood type is so common in the areas where malaria is common. In Nigeria, for instance, more than half of the population belongs to blood group O, which protects against malaria.”

Evolution - on the move!

RIFINs are adhesins implicated in severe Plasmodium falciparum malaria

http://www.nature.com/nm/journal/vaop/ncurrent/full/nm.3812.html

My mother had severe cases of Malaria - not once but 5 times in 2 years some 15 years back! She had a temperature of 104 -107 degrees. We were very worried. And the malaria she got was caused by drug resistant Plasmodium falciparum.

But luckily she survived, now I know the reason. She is O+ve!

Comment by Dr. Krishna Kumari Challa on March 11, 2015 at 9:29am

Comment by Dr. Krishna Kumari Challa on March 11, 2015 at 9:27am

Comment by Dr. Krishna Kumari Challa on March 10, 2015 at 7:34am

Comment by Dr. Krishna Kumari Challa on March 7, 2015 at 6:11am

Comment by Dr. Krishna Kumari Challa on March 7, 2015 at 6:07am

Comment by Dr. Krishna Kumari Challa on March 7, 2015 at 6:01am

Human chimerism occurs when two eggs are released by the mother and are fertilised by two sperm from the father. Normally, this would result in fraternal, non-identical twins, but on rare occasions, these eggs can overlap and fuse to develop into one person who contains two different sets of DNA.

This can cause a person to have two different blood types simultaneously, or to develop both male and female genitals. A DNA sample taken from a chimeric person’s kidney could be completely different from a sample taken from her cervical tissue - an issue that has caused much grief in women trying to prove that they are in fact their children’s biological mothers.

According to researchers at Stanford University in the US, in some cases, chimeric people will have skin made up of two different types of skin cells, encoded by two different sets of DNA. This DNA is responsible for skin tone, which is how patterns can occur. "Often the skin colour of the two types is indistinguishable, or subtle enough that it can only show up under black light”. "Sometimes, however, the two different sets of DNA code for skin types that are dramatically different, which leaves people with literal stripes on their skin in the pattern of Blaschko's lines."

Comment by Dr. Krishna Kumari Challa on March 6, 2015 at 7:00am

Comment by Dr. Krishna Kumari Challa on March 6, 2015 at 6:21am

Drug-induced acute liver failure is uncommon, and over-the-counter medications and dietary and herbal supplements -- not prescription drugs -- are its most common causes, according to new research from the Perelman School of Medicine at the University of Pennsylvania. The findings are published in the current issue of Gastroenterology.

One of the most feared complications of drugs and medications is acute liver failure, traditionally associated with a greater than 50 percent chance of dying without a liver transplant. Drug-induced liver injury, known as hepatotoxicity, is the second most common reason drugs are withdrawn from the market, behind cardiac toxicity, according to the U.S. Food and Drug Administration (FDA). The Penn authors, however, say this is based solely on abnormal liver tests, not actual liver damage. The real risk of acute liver failure that the researchers calculated was 1.61 per million people per year.
Despite hepatotoxicity being the second most common cause of drug withdrawal from the market, acute liver failure, the most severe form of liver injury, from prescription drugs was rare, the team found. They discovered that 75 percent of acute liver failure cases resulting from prescribed medication use were derived from over-the-counter products such as acetaminophen or herbal supplements. “Prescription medications are an exceedingly rare cause of acute liver failure.”
Source: University of Pennslyvania

Comment by Dr. Krishna Kumari Challa on March 6, 2015 at 6:17am

For the first time, an international research team, including a tropical forest ecologist from the University of Exeter, has provided direct evidence of the rate at which individual trees in the Amazon Basin ‘inhale’ carbon from the atmosphere during a severe drought.

The team measured the growth and photosynthesis rates of trees at 13 rainforest plots across Brazil, Peru and Bolivia, comparing plots that were affected by the strong drought of 2010 with unaffected plots. They found that while growth rates of the trees in drought-affected plots were unchanged, the rate of photosynthesis – by which trees convert carbon into energy to fuel their activities – slowed down by around 10 percent over six months.

The paper, published in the journal Nature, concludes that trees may be channelling their more limited energy reserves into growth rather than maintaining their own health. Computer simulations of the biosphere have predicted such responses to drought, but these are the first direct observations of this effect across tropical forests.
"Drought impact on forest carbon dynamics and fluxes in Amazonia"
http://www.nature.com/nature/journal/v519/n7541/full/nature14213.html

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