Scientific News

The Neanderthals also suffered from swimmers ear

Neanderthals also suffered from the so-called “swimmer’s ear” according to a new study published in PLOS ONE.

The researcher Erik Trinkaus of the University of Washington has discovered, with the help of his colleagues, some anomalous bone growths in the ear canal of some very well preserved ear canals found in the remains of various men of accidental Eurasian Neanderthal dating back to the middle Pleistocene late.

The researchers noted that the ear condition swimmer was exceptionally common in Neanderthals. This condition occurs when you expose yourself too often to cold water (or even cold air) even if you believe that a genetic predisposition may exist.

Of the 23 Neanderthal remains examined, about half had mild to severe forms of exostosis, at least twice the frequency observed in almost all the other populations analyzed.

The most obvious explanation is that evidently Neanderthals took longer to collect resources in aquatic environments. However, according to the researchers, there are also other factors that are probably involved in this higher frequency because there is no particular correlation with the proximity of these populations to ancient water sources or to colder climates.

It is believed that one of the causes can be represented by a genetic predisposition of this group.

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.