Anonymous ID: 9219e2 Aug. 4, 2023, 8:40 a.m. No.19296793   🗄️.is đź”—kun

NOW EAR THIS

 

Chronic inflammation of the middle ear can cause several problems and complications that can affect a person's hearing and balance. One such problem is the formation of a cholesteatoma, which is an abnormal collection of cells in the ear that can cause bone erosion if left untreated. In turn, this can cause symptoms such as hearing loss, dizziness, facial paralysis, and even a brain infection.

 

In a study published recently in Nature Communications, researchers from Osaka University have revealed the cause of cholesteatomas, which may help in developing new therapies for patients who are suffering from this disease.

 

Cholesteatomas are made up of cysts or bumps in the ear that consist of skin, collagen fibers, skin cells, fibroblasts, keratin, and dead tissue. There are many theories on how these cholesteatomas can cause bone erosion, including the activation of cells responsible for the breakdown of the minerals and matrix of the bone, the presence of inflammatory markers and enzymes, and the accumulation and pressure from dead cells and tissues in the ear. However, the exact mechanism for the creation of cholesteatomas remains unknown.

 

Subclustering and pseudotime analysis of human cholesteatoma fibroblasts. Cholesteatoma fibroblasts were associated with five subclusters labeled 1, 7, 8, 10, and 11 (right panel). The most differentiated cells (labeled red) were identical to cholesteatoma fibroblasts in subcluster 8 (middle panel). Cholesteatoma fibroblasts showed high levels of INHBA expression, and the area of high INHBA expression was identical to the area in cholesteatoma fibroblasts in subcluster 8 (left panel). Credit: 2023, Masaru Ishii, Single-cell transcriptomics of human cholesteatoma identifies an activin A-producing osteoclastogenic fibroblast subset inducing bone destruction, Nature Communications

"A cholesteatoma can still return or happen again even after its surgical removal, so it is important to know what is actually causing it," says lead author Kotaro Shimizu.

 

To investigate this, researchers looked at human cholesteatoma tissues that were surgically removed from patients. A process called single-cell RNA sequencing analysis was employed to identify cells responsible for triggering bone erosion; these were called osteoclastogenic fibroblasts. This study demonstrated how these fibroblasts expressed an abundant amount of activin A, a molecule that regulates different physiologic functions of the body. The presence of activin A is said to cause bone erosion through a process in which specialized cells initiate bone resorption through a process wherein the minerals and matrix of the bones are broken down and absorbed by the body.

 

The in vivo role of activin A in osteoclastogenesis in an experimental mouse model of cholesteatoma. INHBA inhibition in fibroblasts reduced osteoclast formation on the parietal bone surface under the cholesteatoma mass. Red, osteoclasts; green, parietal bone surface. Scale bars: 500 µm. Credit: 2023, Masaru Ishii, Single-cell transcriptomics of human cholesteatoma identifies an activin A-producing osteoclastogenic fibroblast subset inducing bone destruction, Nature Communications

The researchers were successful in showing the relationship between activin A and bone erosion in cholesteatoma. "Our study showed that targeting activin A is a potential treatment in the management of cholesteatomas," states senior author Masaru Ishii.

 

Currently in clinical settings, the only effective treatment for cholesteatomas is complete surgical removal. However, the discovery of how a cholesteatoma can cause bone erosion in this study offers new hope for developing novel medical treatments as first-line management for cholesteatomas.

 

https://medicalxpress.com/news/2023-08-ear-today-tomorrow-discovery-inner-ear.html

Anonymous ID: 9219e2 Aug. 4, 2023, 8:47 a.m. No.19296818   🗄️.is đź”—kun   >>6826 >>6831 >>6861

Researchers are using monkey poop to learn how an endangered species chooses its mates

 

Northern muriquis, which live in the Atlantic forest of Brazil, are one of the most endangered species of monkey in the world. Choosing good mates and rearing thriving offspring are key to the species' long-term survival.

 

To better understand what goes on in the mating lives of muriquis, researchers at the University of Texas at Austin and the University of Wisconsin–Madison turned to the monkeys' poop to help gain insight into how the primates choose their mates.

 

In a paper published on Aug. 2 in the journal Proceedings of the Royal Society B, the scientists combined genetic analysis with long-term behavioral observations to better understand the reproductive patterns of the endangered muriqui.

 

Unlike most primates, muriquis live in peaceful, egalitarian societies, the core of which is made up of related males and their mothers. Karen Strier, a professor of anthropology at UW–Madison and co-author of the paper, has spent 40 years studying the behavior and ecology of these monkeys in a small, preserved portion of Brazilian forest. She and her team know how to identify each individual monkey and who they are related to. It also means she knows how to tell whose poop is whose.

 

She and her team collected samples and provided them to Anthony Di Fiore, a professor of anthropology and director of the Primate Molecular Ecology and Evolution Lab at UT Austin, and Paulo Chaves, then Di Fiore's graduate student. They used the fecal samples (among the best non-invasive samples they could collect) as a source of DNA to analyze the muriquis' mating behavior through genetic data.

 

Because Strier's field crew knew which sample belonged to whom, the research team was able to ask unique genetic questions.

 

"I knew from behavioral observations that there was lack of competition in mating and that mothers didn't mate with their sons or close male relatives. But the only way to know who the fathers are is with genetics," Strier says.

 

From their lab analysis, Chaves and Di Fiore confirmed that there were no mother-son pairings, which suggests the muriquis may recognize their kin, allowing them to avoid incestuous mating. They also found that females tend to reproduce with males who have a more diverse set of genes coding for molecules that play an important role in the body's immune response to pathogens and other environmental stressors.

 

This interesting class of genes is called the major histocompatibility complex (MHC), and Chaves and Di Fiore were able to characterize genetic variation between individual monkeys.

 

https://phys.org/news/2023-08-monkey-poop-endangered-species.html

 

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