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Comment by Dr. Krishna Kumari Challa on May 8, 2015 at 9:45am

Gram’s Stain Does Not Cross the Bacterial Cytoplasmic Membrane
http://pubs.acs.org/doi/abs/10.1021/acschembio.5b00042
Contrary to standard scientific texts, the purple dye called crystal violet, a main ingredient in gram staining, does not actually enter bacterial cells, researchers report April 27 in ACS Chemical Biology. Instead, the dye gets trapped in a tight package of sugar-filled polymers, called peptidoglycan, which envelops bacterial cells. The thickness and integrity of the sweet bacterial armor determines whether crystal violet leaves a cell purple or not. That royal shade, or lack of it, reveals a cell’s type of outer structure.
Abstract of the paper:
For well over a century, Hans Christian Gram’s famous staining protocol has been the standard go-to diagnostic for characterizing unknown bacteria. Despite continuous and ubiquitous use, we now demonstrate that the current understanding of the molecular mechanism for this differential stain is largely incorrect. Using the fully complementary time-resolved methods: second-harmonic light-scattering and bright-field transmission microscopy, we present a real-time and membrane specific quantitative characterization of the bacterial uptake of crystal-violet (CV), the dye used in Gram’s protocol. Our observations contradict the currently accepted mechanism which depicts that, for both Gram-negative and Gram-positive bacteria, CV readily traverses the peptidoglycan mesh (PM) and cytoplasmic membrane (CM) before equilibrating within the cytosol. We find that not only is CV unable to traverse the CM but, on the time-scale of the Gram-stain procedure, CV is kinetically trapped within the PM. Our results indicate that CV, rather than dyes which rapidly traverse the PM, is uniquely suited as the Gram stain.

Comment by Dr. Krishna Kumari Challa on May 8, 2015 at 9:36am

Scientists stumble across unknown stem-cell type ‘Region-selective’ pluripotent cells raise possibility of growing human organs in animals.

http://www.nature.com/news/scientists-stumble-across-unknown-stem-c...

Comment by Dr. Krishna Kumari Challa on May 5, 2015 at 9:47am

Comment by Dr. Krishna Kumari Challa on May 3, 2015 at 9:00am

Urinary tract infections (UTIs) are common, and widespread antibiotic resistance has led to urgent calls for new ways to combat them. Researchers at University of California, San Diego School of Medicine and Skaggs School of Pharmacy and Pharmaceutical Sciences report that an experimental drug that stabilizes a protein called HIF-1alpha protects human bladder cells and mice against a major UTI pathogen. The drug might eventually provide a therapeutic alternative or complement to standard antibiotic treatment.

The study is published April 30 by PLOS Pathogens.

HIF-1alpha is known to influence the innate immune response, the body’s first line of defense against intruding pathogens. Like many regulator proteins, HIF-1alpha is relatively short-lived. To increase HIF-1alpha levels, researchers have developed drugs that delay its breakdown. This same pathway has been the target for drugs now in advanced clinical trials for treatment of anemia.

In this study, Victor Nizet, MD, professor of pediatrics and pharmacy, and colleagues explored the use of HIF-1alpha-stabilizing drugs to boost the innate immune response to uropathogenic E.coli (UPEC) bacteria, a major cause of UTIs. In healthy human urinary tract cells, treatment with the drugs increased HIF-1alpha levels. Such cells were then more resistant to UPEC attachment, invasion and killing than human urinary tract cells with normal HIF-1alpha levels.

Using a mouse model of UTI, the researchers showed that administration of HIF-1alpha stabilizers directly into the bladder protected against UPEC infection. They also found that invasion of bladder cells, a critical early step in the infection process, was reduced in treated mice compared to untreated mice.

To verify the importance of HIF-1alpha in the defense against UPEC infection, the researchers studied mice with reduced HIF-1alpha levels. Exposed to UPEC, these mice were more susceptible to bladder infection, and pre-treatment with HIF-1alpha stabilizers made no difference. This demonstrates that the drugs combat UTIs through their effect on HIF-1alpha.

Finally, the researchers examined whether treatment with HIF-1alpha stabilizers would be beneficial against an established UTI. To do this, they infected mice with UPEC first and then administered the drugs into the bladder six hours later. The treated mice had a more than 10-fold reduction in bladder colonization with the bacteria, demonstrating that HIF-1alpha stabilization is beneficial even after the initial infection.

“The ultimate goal of this research will be to advance HIF-1alpha stabilizers toward clinical trials in humans, using versions of the drug that can be taken orally and reach the urinary tract,” Nizet said.
http://journals.plos.org/plospathogens/article?id=10.1371/journal.p...

Comment by Dr. Krishna Kumari Challa on May 3, 2015 at 8:52am

Most recently, studies point to a direct role for soil bacteria in shielding crops from drought; improving their growth and ability to absorb nutrients; and enhancing their tolerance of flooding, high temperatures, low temperatures and many other challenges of a changing global climate.
''Turning to Bacteria to Fight the Effects of Climate Change''
http://blogs.scientificamerican.com/guest-blog/2015/04/30/turning-t...

Comment by Dr. Krishna Kumari Challa on May 3, 2015 at 8:45am

Comment by Dr. Krishna Kumari Challa on May 3, 2015 at 8:32am

More than 200 scientists outline potential health concerns from fluorinated chemicals, urge replacements and tightened regulations

Chemicals used to make products waterproof and stain resistant are persistent, pervasive, potentially harmful to humans, and should be regulated and largely replaced, according a statement signed by more than 200 scientists.

The “Madrid Statement” was authored by 14 scientists and signed by 208 more from 38 countries around the world representing a variety of scientific disciplines. The statement was issued amid growing concern that exposure to highly fluorinated chemicals — found everywhere, including in people — is linked to certain cancers, hormone disruption, brain and liver problems and lower birth weights.

“We call on the international community to cooperate in limiting the production and use of PFASs [poly- and perfluoroalkyl substances] and in developing safer non-fluorinated alternatives,” says the statement published in today’s Environmental Health Perspectives journal.
http://www.environmentalhealthnews.org/ehs/news/2015/may/fluorinate...

Comment by Dr. Krishna Kumari Challa on May 1, 2015 at 9:51am

Babies born with drug withdrawal symptoms on the rise in US
The number of infants born in the United States with drug withdrawal symptoms, also known as neonatal abstinence syndrome (NAS), nearly doubled in a four-year period. By 2012, one infant was born every 25 minutes in the U.S. with the syndrome, accounting for $1.5 billion in annual health care charges, according to a new Vanderbilt study published in the Journal of Perinatology.

Neonatal abstinence syndrome has been linked to both illicit drug use as well as use of prescription opioids -- narcotic pain relievers such as hydrocodone -- by pregnant women. Infants born with NAS are more likely to have respiratory complications, feeding difficulty, seizures and low birth-weight.

The study found that from 2009-2012, the incidence of neonatal abstinence syndrome rose in the United States from 3.4 births per 1,000 to 5.8 births per 1,000. Broken down by geographic area, the east south central division (Tennessee, Kentucky, Mississippi and Alabama) had the highest rates of the syndrome, occurring in 16.2 hospital births per 1,000.

"The rise in neonatal abstinence syndrome mirrors the rise we have seen in opioid pain reliever use across the nation. Our study finds that communities hardest hit by opioid use and their complications, like overdose death, have the highest rates of the NAS," said study lead author Stephen Patrick, M.D., MPH, MS, assistant professor of Pediatrics and Health Policy in the Division of Neonatology with the Monroe Carell Jr. Children's Hospital at Vanderbilt.
Source: Vanderbilt University

Comment by Dr. Krishna Kumari Challa on May 1, 2015 at 9:49am

Individuals with Type 2 Diabetes have difficulty regulating their glucose – or blood sugar – levels, particularly after meals. Now, University of Missouri researchers have found that Type 2 diabetics can eat more protein at breakfast to help reduce glucose spikes at both breakfast and lunch.

“People often assume that their glucose response at one meal will be identical to their responses at other meals, but that really isn’t the case,” said Jill Kanaley, professor and associate chair in the MU Department of Nutrition and Exercise Physiology. “For instance, we know that what you eat and when you eat make a difference, and that if people skip breakfast, their glucose response at lunch will be huge. In our study, we found those who ate breakfast experienced appropriate glucose responses after lunch.”

Kanaley and her colleagues monitored Type 2 diabetics’ levels of glucose, insulin and several gut hormones – which help regulate the insulin response – after breakfast and lunch. The participants ate either high-protein or high-carbohydrate breakfasts, and the lunch included a standard amount of protein and carbohydrates.

The researchers found eating more protein at breakfast lowered individuals’ post-meal glucose levels. Insulin levels were slightly elevated after the lunch meal, which demonstrated that individuals’ bodies were working appropriately to regulate blood-sugar levels, Kanaley said.

“The first meal of the day is critical in maintaining glycemic control at later meals, so it really primes people for the rest of the day,” Kanaley said. “Eating breakfast prompts cells to increase concentrations of insulin at the second meal, which is good because it shows that the body is acting appropriately by trying to regulate glucose levels. However, it is important for Type 2 diabetics to understand that different foods will affect them differently, and to really understand how they respond to meals, they need to consistently track their glucose. Trigger foods may change depending on how much physical activity people have gotten that day or how long they have waited between meals.”

Kanaley said that although it would be helpful for individuals with high blood sugar to eat more protein, they do not need to consume extreme amounts of protein to reap the benefits.

“We suggest consuming 25 to 30 grams of protein at breakfast, which is within the range of the FDA recommendations,” Kanaley said.
http://jn.nutrition.org/content/145/3/452

Comment by Dr. Krishna Kumari Challa on April 30, 2015 at 9:49am

HIV-positive men dramatically reduce virus spreading after circumcision but not while wound healing
The World Health Organization recommends male circumcision (the surgical removal of foreskin from the penis) which reduces HIV acquisition by 50-60% for teh control of HIV. However, scientists report that a new study of HIV-infected men in Uganda has identified a temporary, but potentially troublesome unintended consequence of the procedure: a possible increased risk of infecting female sexual partners while circumcision wounds heal.

In a study by researchers from the Johns Hopkins University School of Medicine, the Johns Hopkins University Bloomberg School of Public Health and Rakai Health Sciences Program, 223 HIV-positive Ugandan men were medically circumcised. Health workers poured 5 milliliters (about a teaspoon) of saline solution over the circumcision site near the neck of the penis and collected the solution for testing just before surgery, during the operation, and once a week for 12 weeks.

Data showed that among the 183 men not taking anti-retroviral drugs, less than 10 percent were shedding HIV before circumcision, but nearly 30 percent were shedding the virus two weeks after surgery. The percentages dropped sharply as the men's wounds healed, to less than three percent at six weeks and less than two percent at 12 weeks.

Circumcision reduced the number of HIV-positive men who were shedding the virus more than five-fold over the long term, but it had the opposite effect in the weeks right after the surgery.
""HIV Shedding from Male Circumcision Wounds in HIV-Infected Men: A Prospective Cohort Study""
http://journals.plos.org/plosmedicine/article?id=10.1371/journal.pm...

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