Scientific News

New gut-brain connection linked to satiety discovered

A new study, published in the Journal of Clinical Investigation, confirms once again how closely the intestine is connected to the brain. The study, conducted by researchers at Baylor College of Medicine, reveals a new gut-brain connection never discovered before.

This connection, according to the same researchers, explains in particular how the intake of extra portions of food leads to weight gain. The experiments, again, were performed on mice: those that consumed high-fat foods were characterized by a greater level of gastric inhibitory polypeptide (GIP).

The latter is a gut hormone whose function is to manage the body’s energy balance. It travels through the blood and reaches the brain where it makes leptin, the satiety hormone produced by fat cells, ineffective. This action increased the desire of mice to take more food even if they did not need it.

This naturally produced weight gain. By blocking the GIP, and therefore its action of canceling the function of leptin, the mice started to eat less and lost weight.

As Makoto Fukuda, assistant professor of pediatrics and one of the authors of the study, specifies, this research can be considered not as a solution to obesity but as a “new piece of the complex puzzle of how the body manages energy balance and influences weight.”

However, this information regarding the connection between the intestinal GIP hormone and the leptin in the brain could, however, prove very useful precisely to counteract the same obesity and in general weight gain.

Scientific News

Researchers discover how the leishmania parasite infects the cells of the human immune system

A group of researchers from the Institut National de la Recherche Scientifique (INRS) has published a new study which clarifies the ways in which the Leishmania parasite infects the cells of the human immune system.

This parasite, which causes leishmaniasis, is transmitted to mammals by the bite of a phlebotomine sand fly. The parasite, once inside the mammal’s body, acts through two key molecules to infect cells. These two molecules are the GP63 metalloprotease and the lipophosphoglycan (LPG), also known as virulence factors.

The parasite Achieving the goal by sabotaging the macrophage defense system and thus canceling or otherwise making the immune response less effective. The researchers found that to do this the Leishmania parasite exploits an intracellular transport mechanism, present in the macrophages themselves, to spread virulence factors.

As Albert Descoteaux explains, lead author of the study conducted together with other colleagues, “It is as if there were a train traveling between the different intracellular compartments that parasites use to transport their virulence factors inside the infected cells.”

It is the first time that the Leishmania parasite is shown to transfer its virulence factors from the vacuole to the cytoplasm of the cell.

Scientific News

Bacterium that causes diarrhea is evolving to take advantage of hospital environments

The adaptation to the environment and therefore also to the action of contrast put in place by human beings is refined generation after generation in bacteria. A new study, conducted by a group of researchers from the Wellcome Sanger Institute and the London School of Hygiene and Tropical Medicine, confirms this.

The researchers this time studied the effects of the Clostridium difficile bacterium on the intestine. These bacteria can infect it and represent one of the main causes of antibiotic-associated diarrhea in humans.

In fact, when certain antibiotics are not taken, millions of other bacteria in the human intestine keep Clostridium difficile under control. However, with antibiotics many of the good bacteria are eliminated and this leaves the person vulnerable to the action of Clostridium difficile. The latter, in fact, is very difficult to treat taken individually as a species.

Precisely for the reasons mentioned above, this bacterium thrives in hospitals where, of course, antibiotics are for daily use. The researchers found that it is evolving into two separate species. The new species would have deviated towards a new evolutionary line for two reasons: to adapt to the diets of human beings increasingly characterized by sugar intake and to adapt to health practices and hospital environments.

In fact, it is developing more resistant spores that allow it to stay alive longer when placed on surfaces, which naturally facilitates its diffusion among people.

Researchers analyzed 906 Clostridium difficile strains taken from the body of people or animals or from the environment in the laboratory. They sequenced their DNA and then compared it to find that it is evolving into two separate species.

Nitin Kumar, the study’s first author, explains this in a press release published on the Sanger Institute website: “Our large-scale genetic analysis has allowed us to discover that C. difficile is currently forming a new species with a specialized group in the diffusion in hospital environments. This emerging species has existed for thousands of years, but this is the first time that someone has studied C. difficile genomes in this way to identify it. This particular bacterium was triggered to exploit modern health practices and human diets, even before hospitals existed.”

This study confirms how bacteria can evolve in relation to human behavior.

Scientific News

Nuts protect the intestine from ulcerative colitis in mice

Another study has confirmed the positive properties concerning nuts. The new research, published on Nutrients and conducted by a group of researchers from the Center for Molecular Oncology of the University of Connecticut, emphasizes in particular the positive effects of walnuts on ulcerative colitis.

Ulcerative colitis is an inflammatory bowel disease that sees chronic inflammation of the gastrointestinal tract. The two researchers Daniel Rosenberg Masako Nakanishi conducted some experiments on rodents and found that in a particular model of colitis, one in which there is a lesion of the colonic mucosa caused by the ulcerogenic dextran sodium sulfate agent, the nuts themselves could perform a real action of contrast.

Rodents were given a daily amount of nuts representing 14% of the entire daily diet, an amount equivalent to about 20-25 walnuts for a human being. After two weeks of this treatment, the researchers noticed fewer lesions and generally a repair of the colonic mucosa.

In general, the researchers also noted that the intestinal lesions in mice that ate these amounts of nuts were smaller than in mice that did not eat nuts (both groups had been experimentally induced by ulcerative colitis). They also noted some alterations in fecal and tissue flow as well as various changes in metabolites.

As Rosenberg himself specifies with this research, his team does not intend to suggest that it is necessary to eat 25 nuts a day to counteract ulcerative colitis but still want to find out what those phytochemical active compounds are that in nuts activate this sort of protection of the gastrointestinal tract.

Scientific News

Nuclear reactors for Martian outposts already being tested at NASA

A nuclear reactor that could be used both on the Moon and on Mars to feed human outposts is being designed and could be tested in space in a few years.

The project, called Kilopower, is working on NASA and the US Department of Energy.
According to a statement by Patrick McClure, a test in space with a prototype could be ready to start in three years even if no official statement was issued by NASA or anyone else.

The prototype would be the size of a refrigerator and should naturally be mounted on a rocket. The prototype could supply up to 10 kW of power, a peak that could be enough for eight medium houses here on Earth.

This is not the first time that we think of nuclear energy as a source of energy in space: in the past NASA has used this type of energy, via radioisotope thermoelectric generators, as regards the propulsion of various space vehicles, such as the probes Voyager 1 and Voyager 2 of NASA, or for the operation of the rovers, including Curiosity, the NASA rover present on Mars for several years.

Several ground tests have already been carried out and the system seems to work but of course, only the tests in space will have the last word. The generators of these nuclear reactors convert the heat emitted by the radioactive decay of plutonium-238 into electricity.

A lunar or Martian human outpost will need several kilowatts of power constantly available, at least 40 kW according to scientists, to generate electricity for different purposes, for example to purify water, to generate oxygen, to charge the various rovers and means of transport, for heating and for the various research laboratories.

A single reactor would weigh more than 2000 kilograms, most of which represented by shielding. The prototypes built by NASA scientists can last up to 15 years and can generate up to 10 kilowatts of electricity.

This means that at least four of them should be transported to Mars or to the moon to generate the energy needed for a human outpost and that in any case a way must be found to regenerate them or build new ones on the spot.

Scientific News

Hookahs: study highlights health hazards

Health risks regarding hookah use have been highlighted in a new study published on Aerosol Science and Technology by researchers at the University of California at Irvine.

By analyzing the emissions during various sessions of smokers who used hookahs, the researchers noticed the presence of various toxic and harmful chemicals in addition to nicotine. Among the various compounds, they also noted the presence of irritating carbonyl compounds and carbon monoxide.

“And because of the greater volume inhaled for each puff and the longer duration of a smoking session, the hookah often provides a greater dose of these chemicals to the smoker,” says Veronique Perraud, a researcher at the chemistry department of that university.

The research team also investigated the effect of a nicotine-free herbal blend marketed as a healthier alternative to classic tobacco. They discovered that with the latter there were even higher levels of toxic substances present than smoke.

Among the various tools that the researchers used there is also a pair of mass spectrometers, including a unique model designed by the Smith Group at the same university, to accurately measure the chemical composition of the gases and solids emitted during the sessions of smoke with the almost real hookah.

It is a different method than the previous ones to highlight toxic compounds of smoke: the “classic” method sees the collection of samples from a filter at the end of the session. However, this new technique made it possible to carry out measurements during various steps of the session, at the beginning, in the middle and at the end of it: “We were able to demonstrate that a smoker is exposed to a greater quantity of ultrafine particles during the 10 minutes ahead of the rest of the time,” says Perraud herself.

The same scientist also disproves the myth about the use of hookah that should see the water in the bowl filter toxic chemicals providing a sort of protection for smokers: “In the study, we show that this is not the case with most gas and that, probably due to its cooling effect, water actually promotes the formation of ultrafine particles.”