Ancient Bones Hold TB Clues

A team of Israeli, Palestinian and German scientists is analyzing DNA from human remains that date back to the ancient city of Jericho to try to understand more about the origins of tuberculosis. Cynthia Graber reports Clues about modern-day tuberculosis could be found in some 6,000 year old bones. Israeli, Palestinian and German scientists have teamed up to investigate the remnants of diseases in bones excavated from the ancient city of Jericho. It’s an exercise in paleoepidemiology, the study of ancient diseases in mummified bodies and other human remains. The Jericho bones were unearthed by Dr. Kathleen Kenyon half a century ago. The DNA in the samples will be tested for tuberculosis, leprosy, leishmania and malaria. But the focus is on tuberculosis, which is the biggest killer today.

Scientists believe that tuberculosis originated in the Fertile Crescent 9-10,000 years ago. And Jericho is one of the earliest cities on earth, about 11,000 years old. So there’s a good chance TB could have gotten a start there. Researchers will be studying how early cities—the first time people lived in crowds—affected the DNA of microbes and their human hosts. They’ll also be looking at the remains of animals, which could have been disease vectors. Scientists on the team believe there’s sufficient DNA in the samples to provide new information about the origin and evolution of TB, which could help us combat it today.


Source: 60-Second Science

What is Medical Nanotechnology?

Medical nanotechnology is an emerging area that seeks to use microscopic robots, sensors, cameras or other devices to noninvasively diagnose, protect and treat patients from inside their own bodies, sometimes at the scale of individual cells. Much of this technology remains little more than science-fiction fantasy, but one medical nanotechnology that might reach fruition in the coming decade is the use of nanoscale particles to deliver drugs to specific sites within a patient's body.

Stomach Ulcer Bacteria Migrated with Humans 60,000 Years Ago

In 1985 Australian microbiologist Barry Marshall gobbled a Petri dish full of Helicobacter pylori to prove to the world that the bacteria, rather than stress and spicy foods, were the primary cause of stomach ulcers. Two decades later his recklessness was honoured with the Nobel Prize in Physiology or Medicine, which he shared with his colleague J. Robin Warren. In light of a new study, published in Nature, it is odd that it took so long to finger H. pylori as the source of bouts of abdominal pain, nausea and hemorrhagic vomiting. According to the new work, the pathogen has infected humans for over 60,000 years and its genetic transformation over that time is remarkably similar to that of man—making it a reasonable model for human migration and diversification.

"Like a trail of crumbs, the DNA of our Helicobacter pylori can show where we were born and where our ancestors travelled from over the past 60,000 years," says Marshall, a senior principal research fellow at the University of Western Australia.

According to a 2002 study (published in the New England Journal of Medicine), H. pylori infects 50 percent of the global population. The helical bacterium is the only known microorganism that can survive in the highly acidic mucus lining of the stomach and duodenum, and it is now thought to be the cause of most stomach ulcers and gastritis, an irritation or inflammation of the stomach lining. It is also a risk factor for stomach cancer.

The current study was conducted by an international group of scientists led by University of Cambridge in England and the Max Planck Institute for Biological Infections in Germany. Human populations were broken down by geographic area, moving out of East Africa, believed to be the cradle of human civilization, and into Western Europe, eastern Asia and southern Africa. Researchers were able to estimate that the pathogen emerged from East Africa—not China and southern Africa as previously surmised—between 54,500 and 61,500 years ago. A previous study on human settlement, by Balloux et al. estimated human emergence from the same locale to have occurred 51,500 to 61,500 years ago.

In addition, the research team focused on the microcosm of Europe. They showed that the pathogen was also a viable local model by noting that its pattern of population change on the continent suggested mixing from different geographic sources. This finding is backed by the literature on human migration, which argues that farmers in the Neolithic period moved into Europe from northern Africa and central Asia.

Marshall says molecular epidemiology—"looking at statistical relationships between bacteria from different races"—marks an improvement over studying human migration via ancient human DNA, which degrades if it is more than a few thousand years old. "At present, this is all rather new and the 'clock' has not been calibrated very exactly," he says, "but it is an exciting and fruitful area of new research."

Adapted from materials provided by Scientific American

Diabetes and Vitamin D

Diabetes is characterized by high glucose level in blood. Blood carries glucose to different parts of the body, which obtained through assimilation of the food. Glucose breakdown releases energy and allow the body to perform its necessary work. Glucose level in blood is maintained by insulin, a chemical, produced by pancreas cells of pancreas. Diabetic condition occurs when either pancreas cells fail to produce enough insulin or by the inability of cells of other organs to utilize the secreted insulin. There are three types of diabetes: Type 1, Type 2 and gestational diabetes. In Type 1 diabetes, insulin producing β (beta) cells in the pancreas are destroyed by the body's own immune system and there by insulin production decreases. Type 2 diabetes is the most common form of diabetes. In this form, cells from other organs such as muscles and liver can not use the secreted insulin. Prior to develop type 2 diabetes, pancreas of anyone is known to function normally and secrete as much as insulin required by the body. But over the time, however, it loses its ability to produce sufficient amount of insulin. Thus when patient with type 2 diabetes intake more glucose rich food, the blood glucose level increases beyond the normal level and can be fatal. During the late stage of pregnancy, some women develop diabetes known as gestational diabetes. This form of diabetes usually goes away after the baby is born but the woman who has had it, is more likely to develop type 2 diabetes later in life.

Regular exercise and proper diet help controlling the glucose level in one's body. In severe cases medication is required to avoid the severity of Diabetes. Prolonged uncontrolled diabetes leads to many complication like heart attack, blindness, kidney failure and leg ulcers. A recent study, conducted in the National Public Health Institute, Finland, has shown that a good dose of Vitamin D can help protect anyone against diabetes. Another study has shown that Vitamin D supplements in early childhood may cuts the development of type 1 diabetes in later life. Researchers have found that low blood levels of Vitamin D interfere with the proper function of insulin-producing cells. Low Vitamin D levels also result in an increase in the risk of insulin resistance, even in otherwise healthy individuals. Sunlight helps synthesizing vitamin D in human body. So, consider stepping into the sunshine if you want to increase your own vitamin D levels by natural and thereby reduce the risk of developing diabetes.

Red Alert for Toxic Plastic

The first large study in humans of a chemical widely used in everyday plastics has found that people with higher levels of bisphenol A (BPA) had higher rates of heart disease, diabetes and liver abnormalities, a finding that immediately became the focus of the increasingly heated debate over the safety of the chemical.

The research, published in the Journal of the American Medical Association by a team of British and American scientists, compared the health status of 1,455 men and women with the levels of the chemical, known as BPA, in their urine. The researchers divided the subjects into four statistical groupings according to their BPA levels and found that those in the quartile with the highest concentrations were nearly three times as likely to have cardiovascular disease than those with the lowest levels, and 2.4 times as likely to have diabetes. Higher BPA levels were also associated with abnormal concentrations of three liver enzymes.

The BPA exposure in the study were below those deemed safe by the US Government, adding to a growing body of studies in animals that have linked low-level BPA exposure to various disorders. Trade groups representing the chemical industry and metal can producers dismissed the results. "Due to inherent limitations in study design, this new study cannot support a conclusion that BPA causes any disease," Steven G. Hentges of the American Chemistry Council said in a statement.

“Higher urinary concentrations of BPA were associated with an increased prevalence of cardiovascular disease, diabetes and liver-enzyme abnormalities” wrote the team of British and American researchers of Peninsula Medical school in Exeter, England. They also say follow­-up studies are needed to confirm their work and to determine whether BPA caused the observed health problems.

The British researchers noted that humans are also exposed BPA through the air and contact with the skin. Those findings ran counter to a report by another federal agency, the National Toxicology Program, which found “some concern” that BPA might cause developmental problems in the brain and hormonal systems of infants.

The FDA regulates the compound's use in plastic food containers, bottles, tableware and the plastic linings of food cans. In light of the controversy surrounding the chemical, the agency is reviewing its policy. It issued a draft statement last month that repeated its position that BPA is safe for food and beverage packaging, but it also tapped six outside scientists to review the scientific literature and make a recommendation to agency officials. Notably, more than 100 studies have linked BPA exposure to health effects in animals. The FDA maintains that BPA is safe largely on the basis of two studies funded by the chemical industry, a fact that was repeatedly cited at yesterday's forum.

Adapted from materials provided by The Washington Post

More infortmation on BPA

What is BPA?

BPA is a chemical produced in large quantities to produce polycarbonate plastics and epoxy resins. It is used to give polycarbonate plastics its unbreakable quality.

Where is BPA found?

BPA found in some food and drink packaging, such as water and infant bottles, compact discs (CD), impact resistant safety equipment, dental sealants and medical devices.

How does BPA get in to the body?

The primary source is the diet. BPA can leach into our food from the protective internal epoxy resin coatings of canned foods and from consumer products such as polycarbonate tableware, food storage containers, water bottles and baby bottles. The degree to which BPA leaches from polycarbonate bottles into liquid may depend more on the temperature of the liquid or bottle , than the age of the container. BPA can also found in breast milk.

Source: National Institute of Environmental Health Science (US)

How to avoid BPA exposure?

• Do not microwave polycarbonate plastic food containers. Polycarbonate is strong and durable but over time it may break down from over use at high temperature.
  
• Avoid polycarbonate containers that contain BPA, which usually have number 7 on the bottom (http://recyclenow.org/r_plastics.html).
  
• Reduce your use of canned foods. When possible, use glass, porcelain or stainless steel containers, particularly for hot food and liquids.
  
• Use baby bottles that are BPA free.
  

Prevent skin cancer: Coffee, tea, or...sunscreen?

Coffee, tea, or...sunscreen? That might one day happen if research into the anti-skin cancer properties of caffeine proves true. As this ScienCentral report explains, research into the effects of caffeine in mice shows it can help get rid of sun damaged skin cells before they become cancerous.

Mother’s Flu Shot Protects Newborns

Newborns can be protected from seasonal flu when their mothers are vaccinated during pregnancy, according to a study led by researchers at the Johns Hopkins Bloomberg School of Public Health in collaboration with researchers from the International Centre for Diarrheal Disease Research (ICDDR,B).

The researchers observed a 63 percent reduction in proven influenza illness among infants born to vaccinated mothers while the number of serious respiratory illnesses to both mothers and infants dropped by 36 percent. The study is the first to demonstrate that the inactivated influenza vaccine provides protection to both mother and newborn. The findings were presented during the National Vaccine Advisory Committee meeting in Washington, D.C. on September 17 and will be published in the October 9 issue of the New England Journal of Medicine. Researchers observed 340 mothers and their infants as part of the larger Mother’s Gift vaccine evaluation study. The mothers were randomly selected to receive either flu vaccine or pneumococcal vaccine.

The inactivated influenza vaccine (the flu shot) is not licensed for infants younger than six months. The alternative nasal flu vaccine is not available for children under age 2. The flu shot has been recommended for pregnant women in the U.S. since 1997, although approximately 15 percent of pregnant women are vaccinated each year. “Even though there is no flu vaccine for these children, our study shows that a newborn’s risk of infection can be greatly reduced by vaccinating mom during pregnancy. It’s a two for one benefit,” said Mark Steinhoff, MD, the study’s senior author and professor in the Bloomberg School’s Department of International Health. “Pregnant woman should be encouraged to be vaccinated for the flu to protect their infants and themselves,” said Steinhoff.

Additional authors of the study include K. Zaman, S.E. Arifeen, M. Rahman, R. Raqui, N. Shahid and R.F. Breiman from the International Centre for Diarrheal Disease Research in Bangladesh. E. Wilson is with the Bloomberg School of Public Health and S. B. Omer is with Emory University. The research was supported by the Bill & Melinda Gates Foundation, United States Agency for International Development (USAID), the NPVO Research Fund, Wyeth Pharmaceuticals Inc., the Thrasher Research Fund, Aventis Pasteur, ICDDR,B and the Johns Hopkins Bloomberg School of Public Health.

Adapted from materials provided by Johns Hopkins University Bloomberg School of Public Health.