#mouse study

As a man walks barefoot outdoors, unknowingly his feet encounter very tiny worms. Secretly, one or more of the parasites crawl onto his skin — and then through it. Once inside, these hookworms move around until they end up in their victim’s gut. They latch onto their host’s intestines and from there feast on his blood.

This is not the script for some horror movie. It’s what has already happened to roughly one in every four people on Earth. That’s some 1.9 billion people. But a new study in rodents suggests that hosting these hookworms may have some upsides: weight control and a healthier immune system.

Let’s not downplay the fact that hookworms can bring misery. They eat some of their hosts’ blood, leaving them with lower levels of iron. This may make it hard for the bloodstream to carry a normal load of oxygen through the body, a condition known as anemia (Uh-NEE-mee-uh). The worms also can cause painful rashes and stunt a child’s growth and development. Few doctors, then, would ever prescribe the worms to their patients. But the new data do point to how mammals may have evolved to deal with — indeed, accommodate — some common, nasty infections. And people have had a long time to deal with hookworms. Even ancient mummies show signs of being infected.

During the last century, though, hookworm infections have become rare in developedcountries, such as the United States.

In countries that are not so industrialized, “there are lots of infectious diseases, including worm infections,” notes Haining Shi. He studies diseases in children at Harvard Medical School in Boston, Mass. People who live in such countries, he adds, also have lower rates of certain chronic (long-term) diseases than do folks in industrial nations. This prompted Shi’s team to test an idea: Might parasites help prevent some serious, chronic ailments?

Explainer: All about the calorie

The group decided to focus on obesity. One third of U.S. adults are obese. Nearly one in every six children also are overweight or obese. Carrying too much body fat can lead to a host of other serious health problems, including heart disease and type 2 diabetes.

ORLANDO — Being exposed to a chemical early in life can be a bit like a choose-your-own-adventure book: Some things that happen early on may hurt you later, but only if you make certain choices, an unpublished study in mice suggests.

Mouse pups were exposed to the chemical bisphenol A (BPA) for only five days after birth, a crucial time during which mice’s livers develop. BPA, once common in plastics, has been linked to a host of health problems in people, from diabetes to heart disease (SN: 10/11/08, p. 14). But depending on diet as adults, the mice either grew up to be healthy or to have enlarged livers and high cholesterol.

As long as the BPA-exposed mice ate mouse chow for the rest of their lives, the rodents remained healthy, molecular biologist Cheryl Walker of Baylor College of Medicine in Houston reported April 7 at the 2019 Experimental Biology meeting. But researchers switched some BPA-exposed mice to a high-fat diet as adults. Those mice had larger livers, higher cholesterol and more metabolic problems than mice who ate a high-fat diet but were not exposed to BPA as pups, Walker said.

BPA exposure immediately altered epigenetic marks at more than 5,400 genes, including 3,000 involved in aging. Epigenetic marks are chemical tags on DNA or on histones — protein around which DNA winds in a cell — that don’t change information in genes themselves, but affect gene activity.

Mice live longer, healthier on ketogenic diet, studies claim

A couple new studies find that a ketogenic diet promotes a longer, healthier lifespan. That’s great, but the results have only been confirmed for lab mice. I’ve written about mouse-based dietary studies a few times over the years. None have impressed me much. Some have seemed quite odd. For instance, way back in 2011, I wrote a post entitled “Eating fish makes mice fat, study claims.” Scientists…

BY MALCOLM RITTER, ASSOCIATED PRESS

 NOV 30, 2011

NEW YORK (AP) — As scientists struggle to find a vaccine to prevent infection with the AIDS virus, a study in mice suggests hope for a new approach — one that doctors now want to test in people.

The treated mice in the study appeared to have 100 percent protection against HIV. That doesn’t mean the strategy will work in people. But several experts were impressed.

“This is a very important paper (about) a very creative idea,” says the government’s AIDS chief, Dr. Anthony Fauci. He didn’t take part in the research.

The new study involved injecting mice with a protective gene, an idea that’s been tested against HIV infection in animals for a decade.

In the nearly 30 years since HIV was identified, scientists haven’t been able to find a vaccine that is broadly effective. One boost came in 2009, when a large study in Thailand showed that an experimental vaccine protected about a third of recipients against infection. That’s not good enough for general use, but researchers are now trying to improve it.

Researchers reported the new results in mice online Wednesday in the journal Nature. They hope to test the approach in people in a couple of years. Another research team reported similar success in monkeys in 2009 and hopes to start human tests even sooner.