Category Archives: Medicine

Gut microbes, antibiotics linked to diabetes


Graph of the relationships between groups of bacterial species called OTUs found to occur together in mice either treated with antibiotics or not. Antibiotic-treated mice (red) have a very different, and less diverse, set of OTUs than the control mice (blue). Image courtesy of Nature Microbiology.

Graph of the relationships between groups of bacterial species called OTUs found to occur together in mice either treated with antibiotics or not. Antibiotic-treated mice (red) have a very different, and less diverse, set of OTUs than the control mice (blue). Image courtesy of Nature Microbiology.

Most of the cells in our bodies don’t belong to use; instead, they represent the host of micorganisms in our digestive tracts and play a critical role in extracting the nutrients from the foods we eat.

Yet until recently, scientists have paid little attention to the role these critters may play in our health, other than to ensure we get the nourishment we need to keep our own cells alive and well.

But as regular readers know, studies are revealing that they may play roles in the onset of a wide range of illnesses, ranging from multiple sclerosis and rheumatoid arthritis [our own affliction] to anorexia, chronic fatigue syndrome, and Alzheimer’s disease.

We also know that antibiotics, the drugs we’ve invented to treat once-fatal bacterial infections, can have a lethal impact on those same internally resident creatures, as we’ve sometimes experienced in the diarrhea often accompanying a heavy dose of antibiotics.

By killing off much of our internal alien population, could we actually be contributing to the rise of other dangerous conditions?

Specially, in this case, diabetes?

The answer may well be yes.

From the New York University Langone Medical Center:

In doses equivalent to those used regularly in human children, antibiotics changed the mix of gut microbes in young mice to dramatically increase their risk for type 1 diabetes. That is the finding of a study led by researchers from NYU Langone Medical Center with support from the Juvenile Diabetes Research Foundation (JDRF), and published August 22 in Nature Microbiology [$32 to download].

The study results center on the microbiome, the bacterial species in our guts that co-evolved with humans to play roles in digestion, metabolism, and immunity. As children’s exposure to microbe-killing antibiotics has increased in recent decades, the incidence of autoimmune diseases like type 1 diabetes has more than doubled. The average American child currently receives 10 courses of antibiotics by age 10.

Specifically, the new study found that short pulses of antibiotics cause mice that are susceptible to type 1 diabetes to develop the disease more quickly and more often than mice not treated with antibiotics.

“Our study begins to clarify the mechanisms by which antibiotic-driven changes in gut microbiomes may increase risk for type 1 diabetes,” says Martin Blaser, MD, the Muriel G. and George W. Singer Professor of Translational Medicine at NYU School of Medicine, and the study’s senior author. “This work uses NOD mice, the best model of type 1 diabetes to date, and doses of antibiotics like those received by most children to treat common infections.”

“This latest study result is compelling, linking the effects of use of antibiotics in mice to type 1 diabetes,” says Jessica Dunne, director of discovery research at JDRF. “This is the first study of its kind suggesting that antibiotic use can alter the microbiota and have lasting effects on immunological and metabolic development, resulting in autoimmunity. We’re eager to see how these findings may impact the discovery of type 1 diabetes preventive treatments in the future and continued research in the area of vaccines.”

More after the jump. . .
Continue reading

Plastic food packaging to get edible replacement


We posted extensively about the health dangers posed by the plastics used to contain the foods we eat. The stuff ha been linked to everything from cancer obesity to ADHD and and the growth of man boobs.

And now comes word that scientists are developing a replacement, one we can eat.

From Bloomberg:

Much of the plastic packaging we see in the grocery store can be recycled, from egg containers, to milk jugs, to butter tubs. But what about that thin plastic film stretched around wedges of manchego in the cheese bin or the 16-ounce rib-eye in the chiller case?

It turns out that kind of plastic is tougher to recycle and might even be adding harmful chemicals to your food. Oh, and it’s not even good at doing what it’s supposed to do: prevent food spoilage.

Luckily, researchers are investigating alternative forms of food packaging—the kind you can eat.

U.S. Department of Agriculture researchers have discovered that a milk protein called casein can be used to develop an edible, biodegradable packaging film. The casein-based film is up to 500 times better than plastic at keeping oxygen away from food because proteins form a tighter network when they polymerize, the researchers found. It’s also more effective than current edible packaging materials made from starch and protects food products that are sensitive to light.

To produce a more practical packaging material, the team added glycerol and citrus pectin to the casein film, which is made by spreading a mixture of water and commercially available casein powder. Glycerol made the protein film softer, and citrus pectin added more structure to the film, allowing it to resist humidity and high temperatures better. Bonnaillie said the additives used by researchers also distinguish their packaging, because pectin is good for us.

Flavorings, vitamins, and other additives can be used to make the packaging, and the food it surrounds, tastier and more nutritious.

Sounds like a good idea.

NIH warns: Zika could spread across Gulf states


From Reuters:

One of the top U.S. public health officials on Sunday warned that the mosquito-borne Zika virus could extend its reach across the U.S. Gulf Coast after officials last week confirmed it as active in the popular tourist destination of Miami Beach.

The possibility of transmission in Gulf States such as Louisiana and Texas will likely fuel concerns that the virus, which has been shown to cause the severe birth defect known as microcephaly, could spread across the continental United States, even though officials have played down such an outcome.

Concern has mounted since confirmation that Zika has expanded into a second region of the tourist hub of Miami-Dade County in Florida. Miami’s Wynwood arts neighborhood last month became the site of the first locally transmitted cases of Zika in the continental United States.

“It would not be surprising we would see additional cases perhaps in other Gulf Coast states,” Dr. Anthony Fauci, director of the allergy and infectious diseases unit of the National Institutes of Health (NIH), said in an interview on Sunday morning with ABC News.

Fauci noted that record flooding this month in Louisiana – which has killed at least 13 people and damaged some 60,000 homes damaged – has boosted the likelihood Zika will spread into that state.

Map of the day: The U.S. makes the WHO Zika map


From the Pan American Health Organization, a subdivision of the World Health Organization, the latest map of nations in the Americas with active transmission of the mosquito-borne Zika virus, finally includes the U.S., following the outbreak in Florida:

BLOG Map

And from the World Health Organization, the latest update on countries with active transmission:

BLOG Chart

Map of the day: Global tuberculosis prevalence


From Nature Reviews Rheumatology, using date from 2011:

BLOG TB

Zika may cause adult memory loss, depression


Zika in the adult brain: Illumination of the fluorescent biomarker in green revealed that Zika can infect the adult mouse brain in a region full of neural progenitor cells, which play an important role in learning and memory.

Zika in the adult brain: Illumination of the fluorescent biomarker in green revealed that Zika can infect the adult mouse brain in a region full of neural progenitor cells, which play an important role in learning and memory. From the study.

Zika, the mosquito-borne virus that spread from West Africa to Latin America and the Western Pacific and resident in Florida, not only causes shrunken skulls and damaged brain in infants born to infected mothers. It may also cause depression and Alzheimer’s-like memory loss in adults.

That’s the disturbing finding of new research on the impact of the virus on the human brain.

From the Rockefeller University:

Concerns over the Zika virus have focused on pregnant women due to mounting evidence that it causes brain abnormalities in developing fetuses. However, new research in mice from scientists at The Rockefeller University and La Jolla Institute for Allergy and Immunology suggests that certain adult brain cells may be vulnerable to infection as well. Among these are populations of cells that serve to replace lost or damaged neurons throughout adulthood, and are also thought to be critical to learning and memory.

“This is the first study looking at the effect of Zika infection on the adult brain,” says Joseph Gleeson, adjunct professor at Rockefeller, head of the Laboratory of Pediatric Brain Disease, and Howard Hughes Medical Institute investigator. “Based on our findings, getting infected with Zika as an adult may not be as innocuous as people think.”

Although more research is needed to determine if this damage has long-term biological implications or the potential to affect behavior, the findings suggest the possibility that the Zika virus, which has become widespread in Central and South America over the past eight months, may be more harmful than previously believed. The new findings were published in Cell Stem Cell[open access] on August 18.

“Zika can clearly enter the brain of adults and can wreak havoc,” says Sujan Shresta, a professor at the La Jolla Institute of Allergy and Immunology. “But it’s a complex disease—it’s catastrophic for early brain development, yet the majority of adults who are infected with Zika rarely show detectable symptoms. Its effect on the adult brain may be more subtle, and now we know what to look for.”

Neuronal progenitors

Early in gestation, before our brains have developed into a complex organ with specialized zones, they are comprised entirely of neural progenitor cells. With the capability to replenish the brain’s neurons throughout its lifetime, these are the stem cells of the brain. In healthy individuals, neural progenitor cells eventually become fully formed neurons, and it is thought that at some point along this progression they become resistant to Zika, explaining why adults appear less susceptible to the disease.

But current evidence suggests that Zika targets neural progenitor cells, leading to loss of these cells and to reduced brain volume. This closely mirrors what is seen in microcephaly, a developmental condition linked to Zika infection in developing fetuses that results in a smaller-than-normal head and a wide variety of developmental disabilities.

The mature brain retains niches of these neural progenitor cells that appear to be especially impacted by Zika. These niches—in mice they exist primarily in two regions, the subventricular zone of the anterior forebrain and the subgranular zone of the hippocampus—are vital for learning and memory.

There’s more, after the jump. . . Continue reading

CDC warns pregnant women to avoid Miami


And the reason is local mosquitoes are now carrying Zika, a virus capable of causing birth defects, including abnormally small skulls [microcephaly].

From the Centers for Disease Control:

The Centers for Disease Control and Prevention (CDC) has been working with Florida health officials on investigating cases of locally transmitted Zika virus. An additional area of active Zika transmission has been identified in a section of Miami Beach, in addition to the area of active Zika transmission near Wynwood. The Florida Department of Health has also identified at least four other instances of apparently mosquito-borne Zika in Miami-Dade County, and has reported an increase in travel-related cases.

Based on this new information, CDC and Florida health officials are now recommending the following:

  • Pregnant women should avoid travel to the designated area of Miami Beach, in addition to the designated area of Wynwood, both located in Miami-Dade County, because active local transmission of Zika has been confirmed.
  • Pregnant women and their partners living in or who must travel to the designated areas should be aware of active Zika virus transmission and follow steps to prevent mosquito bites.
  • Women and men who live in or who have traveled to the designated area of Miami Beach since July 14, 2016 should be aware of active Zika virus transmission; pregnant women should see their doctor or other healthcare provider about getting tested for Zika; and people who have a pregnant sex partner should consistently and correctly use condoms to prevent infection during sex or avoid having sex for the duration of the pregnancy.
  • Pregnant women and their sexual partners who are concerned about potential Zika virus exposure may also consider postponing nonessential travel to all parts of Miami-Dade County.
  • All pregnant women in the United States should be evaluated for possible Zika virus exposure during each prenatal care visit.  Each evaluation should include an assessment of signs and symptoms of Zika virus disease (acute onset of fever, rash, arthralgia, conjunctivitis); their travel history; as well as their sexual partner’s potential exposure to Zika virus and history of any illness consistent with Zika virus disease to determine whether Zika virus testing is indicated.
  • Women with Zika should wait at least 8 weeks after symptoms start before trying to get pregnant.
  • Men with Zika should wait at least 6 months after symptoms start before couples try to get pregnant.
  • Women and men without confirmed Zika who traveled to this area should wait at least 8 weeks before trying to get pregnant.
  • Women and men who live in or frequently travel to this area and who do not have signs or symptoms of Zika should talk to their healthcare provider to inform their decisions about timing of pregnancy.