Articoli filtrati per data: Agosto 2018


Un nuovo studio, coordinato dalla Sapienza, ha individuato in topi sottoposti a stress emotivo prolungato l’attivazione di sequenze di Dna mobili in specifiche regioni del cervello. Questi elementi sono in grado di alterare le funzioni del genoma con possibili effetti nocivi sull’organismo. I risultati della ricerca sono pubblicati sulla rivista Stress, The International Journal on the Biology of Stress
Il lavoro coordinato da Lucia Piacentini e Arianna Rinaldi del Dipartimento di Biologia e biotecnologie Charles Darwin della Sapienza suggerisce una base genetica per i possibili danni alla salute dovuti a un forte stress emotivo. I ricercatori hanno osservato che nei topi, modello animale “vicino” all’uomo per molte caratteristiche molecolari, l’esposizione prolungata a condizioni di stress è in grado di indurre l’attivazione incontrollata di elementi genetici mobili (trasposoni) e dunque possibili gravi conseguenze per l’organismo. I risultati dello studio sono stati pubblicati sulla rivista Stress, The International Journal on the Biology of Stress.

Pubblicato in Medicina

RNA modification defects can lead to high blood pressure

Genetic information is stored in DNA and is passed on in a very stable manner from one cell to the next or from one generation to the next. On a cellular level, genetic information is transcribed from DNA into RNA (ribonucleic acid) and then mostly "translated" into proteins, which carry out cellular functions. This normally involves modifying the RNA so that this information can be “read" correctly or used appropriately – in order to adapt to changes in prevailing conditions. Researchers from the Division of Cell and Developmental Biology at MedUni Vienna have now shown that defects in this RNA modification can result in altered smooth muscle contraction, cardiovascular diseases and high blood pressure. 

The main finding of the study by lead author Mamta Jain supervised by Franz-Michael Jantsch of MedUni Vienna's Division of Cell and Developmental Biology is: if a particular RNA modification in smooth muscle is defective or inadequate in the mouse model, there is a greater likelihood of high blood pressure and cardiovascular problems developing as a result of over-contraction. Working with MedUni Vienna's Division of Anatomy, this finding was further corroborated by post-mortem tests on bodies donated to science: defective RNA modification in the aortic muscles was observed in those who had died with a hypertrophic, or enlarged, heart: This vital modification was around 50% lower than in most people. Normally, RNA modification of 90% can be read in the proteins but, in the affected individuals, it was below 40%.

Pubblicato in Scienceonline
Sabato, 11 Agosto 2018 07:54

How to Trigger Innate Fear Response?

Figure:This illustration describes how ACC-BLA circuit controls innate freezing response depending on its activity level

When animals encounter danger, they usually respond to the situation in one of two ways: to freeze or to flee. How do they make this quick decision in a life or death moment? According to KAIST neuroscientists, there are two types of fear: learned versus innate. The latter is known to be induced without any prior experience and is thus naturally encoded in the brain. A research team under Professor Jin-Hee Han in the Department of Biological Sciences identified the brain circuit responsible for regulating the innate fear response.

The study, which appeared in the July 24 issue of Nature Communications represents a significant step toward understanding how the neural circuits in the prefrontal cortex create behavioral responses to external threats. This also represents a new paradigm in therapeutic development for fear-related mental disorders. Responses of freezing or fleeing when facing external threats reflect behavioral and physiological changes in an instinctive move to adapt to the new environment for survival.

Pubblicato in Scienceonline

Researchers from the Marine Megafauna Foundation, University of Southampton, and Sharkwatch Arabia have used a 'biological passport' to monitor the habits of the whale shark, Earth's largest fish

Whale sharks, the world’s largest fish, roam less than previously thought. Local and regional actions are vital for the conservation of this globally endangered species moving forward, according to a new study by researchers from the Marine Megafauna Foundation, University of Southampton, and Sharkwatch Arabia. Their findings are published today in the journal Marine Ecology Progress Series.

Previously, genetic research indicated that whale sharks mixed within distinct populations in the Indo-Pacific and Atlantic Ocean, respectively. This new study used stable isotope analysis, a biochemical technique, to demonstrate that whale sharks feeding at three disparate sites in the Western Indian Ocean (Mozambique and Tanzania) and the Arabian Gulf (Qatar) rarely swim more than a few hundred kilometers north or south from these areas.
 
“Whale sharks are amazing swimmers, often moving over 10000 km each year, and they can dive to around 2000 meters in depth. Biochemical studies tell us more about where they go and what they do when they’re out of our sight”, said Dr Clare Prebble, who led the research as part of her PhD project at the University of Southampton.
 
The researchers used isotopes of nitrogen and carbon that have similar chemical properties, but vary in their atomic mass. Ratios between the heavier and lighter isotopes of these elements vary naturally across different habitats in the marine environment. For example, more of the heavier isotopes are found in near-shore environments than offshore. These ratios stay consistent as they are passed up through the food web, from tiny marine plants to top predators, and therefore provide a record of the animal’s feeding and movement behaviors. Stable isotope analysis thereby provides a ‘biological passport’ for whale sharks.

Pubblicato in Scienceonline

 

 
 

Atrial fibrillation is an irregular and often rapid heart rate that can increase the risk of stroke, heart failure and other heart-related complications. It’s more common in older people, and as it happens, in people who are obese. But new research suggest that exercise can have a moderating effect on the risk of developing this problem.

“The risk of atrial fibrillation was lower the more physically active a person was. This turned out to be especially true for people with obesity,” says Lars Elnan Garnvik, a PhD candidate atNTNU’sCardiac Exercise Research Group.

Garnvik has just published his results in theEuropean Journal of Preventive Cardiology.

Risk doubles for inactive obese individuals

Atrial fibrillation is the most common form of heart fibrillation, and more than 100,000 Norwegians have the disease. Primarily older people are affected, and given the ageing population, twice as many Norwegians as today may well have atrial fibrillation in a few decades.

Obesity is also a well-known risk factor for atrial fibrillation. Garnvik’s study showed that people with a BMI greater than 30 have a significantly higher risk than normal weight individuals. It turns out that the activity level of obese participants plays an important role.

“People who reported that they didn’t exercise at all had about double the risk of developing fibrillations, when compared to those who were physically active whose body weight was normal,” Garnvik said. “However, people who were obese but who exercised a lot limited the increase in risk to no more than approximately 50 per cent. This suggests that physical activity is good for limiting the increased risk of atrial fibrillation in obese people.”

Pubblicato in Scienceonline

CEU UCH research group

Retinitis pigmentosa is a rare and hereditary neurodegenerative disease which causes vision loss due to the death of photoreceptors in the retina, and for which there is currently no treatment. The research group at the Universidad CEU Cardenal Herrera on Therapeutic Strategies for Ocular Pathologies, headed by professor María Miranda Sanz, had already tested in a previous study the efficiency of progesterone to ameliorate the death of photoreceptor cells in the retina caused by this disease. Now, in a new project published in the scientific journal Frontiers in Pharmacology, they have observed a higher protective effect of progesterone when combined with a strong antioxidant: lipoic acid.

As highlighted by doctor María Miranda, professor at the CEU UCH and main researcher of the group, “in this new study we verified that both progesterone and the lipoic acid are separately able to protect photoreceptors in the retina from cell death, but their simultaneous application provides even better results than individually. These results, obtained in animal models, administering both substances orally, could be the basis for developing future treatments to ameliorate the eyesight deterioration caused by retinitis pigmentosa. There is currently no treatment for a disease which represents half of those that degenerate the retina around the world.”

Pubblicato in Scienceonline
 
Sta destando scalpore nella comunita' scientifica uno studio appena pubblicato sulla rivista Gut che dimostra come l'obesita' nell'adolescente rappresenti un importante fattore di rischio per cirrosi epatica e tumore del fegato. Lo studio e' stato condotto su 1,2 milioni di giovani maschi svedesi dell'eta' compresa tra 17 e 19 anni, nati tra il 1951 e il 1976, i cui dati erano stati raccolti nei registri nazionali al momento della chiamata al servizio militare tra il 1969 ed il 1996, quando in quegli anni il servizio di leva era obbligatorio per cui tutti i ragazzi, eccetto una modesta percentuale del 2-3%, erano stati registrati (HagstromGut 2018).

"La Societa' Italiana di Gastroenterologia e Endoscopia digestiva (Sige) e' fortemente impegnata nella ricerca di base e nella ricerca clinica sulle malattie epatiche causate dal sovrappeso e dalla obesita'- sottolineano il presidente Domenico Alvaro e la vicepresidente Patrizia Burra- Il forte messaggio che emerge dal lavoro appena pubblicato dai colleghi svedesi sul rapporto tra obesita' negli adolescenti e rischio di sviluppare nell'eta' adulta malattia del fegato con progressione in fibrosi e cirrosi e sviluppo del tumore epatico, rappresenta un ulteriore stimolo alla ricerca in Gastroenterologia ed Epatologia per prevenire le malattie del fegato, intervenendo sul controllo di fattori di rischio modificabili, come l'alimentazione, il peso corporeo, l'uso inadeguato di bevande alcoliche".
Pubblicato in Medicina

Primi risultati dello studio su un piccolo coleottero verde, considerato scomparso da oltre un secolo e ritrovato lo scorso anno dal team di ricercatori della Sapienza nel cuneese. La ricerca, associata al ritrovamento della specie, fa luce su importanti aspetti della sua ecologia, biogeografia e biologia della conservazione. Lo studio è pubblicato sulla rivista Insect Conservation and Diversity Proprio come i mitici e inafferrabili folletti dei boschi, chiamati “salvan” dagli abitanti delle Alpi Marittime, una isolatissima specie di piccoli coleotteri verdi della famiglia dei Nitidulidi era sfuggita per più di un secolo alle intense ricerche degli entomologi italiani e francesi. Quando ormai era data per estinta, lo scorso anno il team di ricercatori della Sapienza, coordinato da Paolo Audisio del Dipartimento di Biologia e biotecnologie “Charles Darwin”, ha ritrovato, durante una breve spedizione in una località delle Alpi Marittime sopra l’abitato di Palanfré, pochi esemplari dell’elusivo insetto Brassicogethes salvan. Qui i ricercatori hanno finalmente individuato anche la sua pianta ospite, la rara e subendemica Brassicacea Descurainia tanacetifolia.

Pubblicato in Ambiente

 

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