Gene behind freckles, brown hair and blue eyes found

November 23, 2013

boards.weddingbee.comWashington, Nov 23: In the study of Icelanders, researchers uncovered an intricate pathway involving the interspersed DNA sequence, or non-coding region, of a gene that is among a few dozen associated with human pigmentation traits.

It is more common to find people with ancestors from geographic locations farther from the equator, such as Iceland, who have less pigment in their skin, hair and eyes.

The researchers, including scientists from the National Human Genome Research Institute (NHGRI), analysed data from a genome-wide association study (GWAS) of 2,230 Icelanders.

A GWAS compares hundreds of thousands of common differences across individuals' DNA to see if any of those variants are associated with a known trait.

"This study explains a complex molecular pathway that may also contribute insights into skin diseases, such as melanoma, which is caused by the interaction of genetic susceptibility with environmental factors," said NHGRI Scientific Director Dan Kastner.

Researchers focused on the interferon regulatory factor 4 (IRF4) gene, previously associated with immunity. IRF4 makes a protein that spurs production of interferons, proteins that fight off viruses or harmful bacteria.

The researchers noted from genomic databases that the IRF4 gene is expressed at high levels only in lymphocytes, a type of white blood cell important in the immune system, and in melanocytes, specialized skin cells that make the pigment melanin. The new study established an association between the IRF4 gene and the pigmentation trait.

"Genome-wide association studies are uncovering many genomic variants that are associated with human traits and most of them are found in non-protein-coding regions of the genome," said William Pavan, co-author and senior investigator, Genetic Disease Research Branch, NHGRI.

The Icelandic GWAS yielded millions of variants among individuals in the study. The researchers narrowed their study to 16,280 variants located in the region around the IRF4 gene.

They used an automated fine-mapping process to explore the set of variants in IRF4 in 95,085 people from Iceland. The data revealed that a variant in a non-coding, enhancer region that regulates the IRF4 gene is associated with the combined trait of sunlight sensitivity, brown hair, blue eyes and freckles.

The study was reported in the journal Cell.

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Agencies
February 23,2020

Los Angeles, Feb 23: According to researchers, if administered quickly, a common medication that reduces bleeding could be a treatment for bleeding stroke.

The Spot Sign and Tranexamic Acid on Preventing ICH Growth - Australasia Trial (STOP-AUST) was a multicenter, prospective, randomized, double-blind, placebo-controlled, phase 2 clinical trial using the antifibrinolytic agent tranexamic acid in people with intracerebral hemorrhage (ICH).

ICH is a severe form of acute stroke with few treatment options.

Tranexamic acid is currently used to treat or prevent excessive blood loss from trauma, surgery, tooth removal, nosebleeds and heavy menstruation. For this study, one hundred patients with active brain bleeding were given either intravenous tranexamic acid or placebo within 4.5 hours of symptom onset.

Researchers analyzed brain CT scans taken during the 24-hour period after treatment with tranexamic acid or placebo.

Researchers found a trend towards reduced hemorrhage expansion in the group treated with tranexamic acid, especially in those treated within 3 hours of the brain bleed. However, this trend was not statistically significant. The finding was consistent with previous research using the medication.

"Further trials using tranexamic acid are ongoing and focusing on ultra-early treatment - within 2 hours. 

This is where the greatest opportunity for intervention appears to be. Tranexamic acid is inexpensive, safe and widely available. Our results and others provide great impetus for further, focused research using this treatment," Nawaf Yassi said.

Larger trials focused on patient outcomes are required for this therapy to enter routine clinical practice.

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Agencies
June 23,2020

The record levels of new daily COVID-19 cases are due to the fact that the pandemic is peaking in a number of big countries at the same time and reflect a change in the virus' global activity, the World Health Organisation said.

At a media briefing on Monday, WHO's emergencies chief Dr Michael Ryan said that the numbers are increasing because the epidemic is developing in a number of populous countries at the same time.

Some countries have attributed their increased caseload to more testing, including India and the US But Ryan dismissed that explanation.

We do not believe this is a testing phenomenon, he said, noting that numerous countries have also noted marked increases in hospital admissions and deaths neither of which cannot be explained by increased testing.

There definitely is a shift in that the virus is now very well established, Ryan said. The epidemic is now peaking or moving towards a peak in a number of large countries.

He added the situation was definitely accelerating in a number of countries, including the US and others in South Asia, the Middle East and Africa.

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January 25,2020

Washington D.C., Jan 25: A new study conducted by a team of researchers reveals why individuals who have a history of early life adversity (ELA) are disproportionately prone to opioid addiction.

The study conducted examined how early adversities interact with factors such as increased access to opioids to directly influence brain development and function, causing a higher potential for opioid addiction.

The study was lead by UCI researchers and was published in Molecular Psychiatry.

Tallie Z. Baram, MD, PhD, the Danette Shepard Chair in Neurological Sciences at the UCI School of Medicine and one of the senior researchers for the study, was on the take that the widely known factor genetics that plays major role in addiction vulnerability, cannot be solely held responsible for the recent rise in opioid abuse.

To further clarify, the researchers simulated ELA in rats by limiting bedding and nesting materials during a short, postnatal period of time.

In female rats, this led to striking opioid addiction-like characteristics including an increased relapse- behaviour, for example.

As observed in addicted humans, the rats were willing to work very hard (pay a very high price) to obtain the drug.

Baram said: "Ultimately, we found that conditions during sensitive developmental periods can lead to vulnerability to the addictive effects of opioid drugs, especially in females, which is consistent with the prevalence of ELA in heroin-addicted women."

These findings can be used to highlight the importance given to sex differences in future ELA-related studies on opioid addiction, and in future prevention or intervention strategies being developed to address the growing opioid crisis.

The study conducted examined how early adversities interact with factors such as increased access to opioids to directly influence brain development and function, causing a higher potential for opioid addiction.

The study was lead by UCI researchers and was published in Molecular Psychiatry.

The study found that unpredictable, fragmented early life environments may lead to abnormal maturation of certain brain circuits, which profoundly impacts brain function and persists into adolescence and adulthood.

Tallie Z. Baram, MD, PhD, the Danette Shepard Chair in Neurological Sciences at the UCI School of Medicine and one of the senior researchers for the study, was on the take that the widely known factor genetics that plays major role in addiction vulnerability, cannot be solely held responsible for the recent rise in opioid abuse.

To further clarify, the researchers implanted ELA in rats by limiting bedding and nesting materials during a short, postnatal period of time.

In female rats, this led to striking opioid addiction-like characteristics including an increased relapse- behaviour, for example.

As observed in addicted humans, the rats were willing to work very hard (pay a very high price) to obtain the drug.

Baram said: "Ultimately, we found that conditions during sensitive developmental periods can lead to vulnerability to the addictive effects of opioid drugs, especially in females, which is consistent with the prevalence of ELA in heroin-addicted women."

These findings can be used to highlight the importance given to sex differences in future ELA-related studies on opioid addiction, and in future prevention or intervention strategies being developed to address the growing opioid crisis.

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