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Comment by Dr. Krishna Kumari Challa on June 24, 2017 at 7:00am

Comment by Dr. Krishna Kumari Challa on June 24, 2017 at 6:01am

Hormones made by brain...

Bones give us structural support to out bodies. We all know that. Apart from that function, bones also make hormones. Do you know this fact?

Yes, there’s so much going on between bone and brain and all the other organs, it has become one of the most prominent tissues being studied at the moment.

At least four bone hormones found working in living systems, recent studies show, and there could be more. Scientists have only just begun to decipher what this messaging means for health. But cataloging and investigating the hormones should offer a more nuanced understanding of how the body regulates sugar, energy and fat, among other things.

Of the hormones on the list of bones’ messengers — osteocalcin, sclerostin, fibroblast growth factor 23 and lipocalin 2 — the last is the latest to attract attention. Lipocalin 2, which bones unleash to stem bacterial infections, also works in the brain to control appetite, physiologist Stavroula Kousteni of Columbia University Medical Center and colleagues reported in the March 16 Nature.

After mice eat, their bone-forming cells absorb nutrients and release a hormone called lipocalin 2 (LCN2) into the blood. LCN2 travels to the brain, where it gloms on to appetite-regulating nerve cells, which tell the brain to stop eating, a recent study suggests.

Geneticist Gerard Karsenty of Columbia University Medical Center found that osteocalcin — made by osteoblasts — helps regulate blood sugar. Osteocalcin circulates through the blood, collecting calcium and other minerals that bones need. When the hormone reaches the pancreas, it signals insulin-making cells to ramp up production, mouse experiments showed. Osteocalcin also signals fat cells to release a hormone that increases the body’s sensitivity to insulin, the body’s blood sugar moderator, Karsenty and colleagues reported in Cell in 2007. If it works the same way in people, Karsenty says, osteocalcin could be developed as a potential diabetes or obesity treatment.

Comment by Dr. Krishna Kumari Challa on June 23, 2017 at 7:13am

Comment by Dr. Krishna Kumari Challa on June 23, 2017 at 6:41am

Metagenomic sequencing study:

The test is the brainchild of researchers at the  University of California, San Francisco, led by neurologist Michael Wilson, biochemist Joseph DeRisi and infectious disease expert Charles Chiu. The group uses genetic-sequencing technology to identify mystery illnesses in people with encephalitis or meningitis (inflammation of the meninges, the membranes around the brain and spinal cord). This so-called metagenomic test analyzes all the DNA and RNA found in a sample of cerebrospinal fluid (meta means “beyond” in Greek). So any DNA or RNA that does not belong to the patient—including that from viruses, bacteria, parasites or fungi—shows up in the results.

Done correctly, metagenomic testing could radically change the way infections of the brain are diagnosed. An element of circular logic underlies most standard infectious disease tests. Doctors order individual tests for each bug they suspect might be causing the problem. But how do they know what is causing the problem if they have not yet done the test? Metagenomic sequencing, in contrast, casts the broadest possible net, which allows it to pick up unexpected or previously unknown pathogens. Scientists and doctors are looking at everything at once, which has the potential of replacing the myriad of lab tests with a single test.

Genetic sequencing of Cerebro-spinal fluid hailed as an advance over standard procedures for diagnosing brain infections

Comment by Dr. Krishna Kumari Challa on June 21, 2017 at 9:41am

Potent Inhibitor of Drug-Resistant HIV-1 Strains Identified from the Medicinal Plant Justicia gendarussa

Justicia gendarussa, a medicinal plant collected in Vietnam, was identified as a potent anti-HIV-1 active lead from the evaluation of over 4500 plant extracts. Bioassay-guided separation of the extracts of the stems and roots of this plant led to the isolation of an anti-HIV arylnaphthalene lignan (ANL) glycoside, patentiflorin A (1). Evaluation of the compound against both the M- and T-tropic HIV-1 isolates showed it to possess a significantly higher inhibition effect than the clinically used anti-HIV drug AZT. Patentiflorin A and two congeners were synthesized, de novo, as an efficient strategy for resupply as well as for further structural modification of the anti-HIV ANL glycosides in the search for drug leads. Subsequently, it was determined that the presence of a quinovopyranosyloxy group in the structure is likely essential to retain the high degree of anti-HIV activity of this type of compounds. Patentiflorin A was further investigated against the HIV-1 gene expression of the R/U5 and U5/gag transcripts, and the data showed that the compound acts as a potential inhibitor of HIV-1 reverse transcription. Importantly, the compound displayed potent inhibitory activity against drug-resistant HIV-1 isolates of both the nucleotide analogue (AZT) and non-nucleotide analogue (nevaripine). Thus, the ANL glycosides have the potential to be developed as novel anti-HIV drugs.

http://pubs.acs.org/doi/abs/10.1021/acs.jnatprod.7b00004

Comment by Dr. Krishna Kumari Challa on June 17, 2017 at 9:10am

Quantum communication...

A successful quantum communication network will rely on the ability to distribute entangled photons over large distances between receiver stations. So far, free-space demonstrations have been limited to line-of-sight links across cities or between mountaintops. Scattering and coherence decay have limited the link separations to around 100 km. Yin et al. used the Micius satellite, which was launched last year and is equipped with a specialized quantum optical payload. They successfully demonstrated the satellite-based entanglement distribution to receiver stations separated by more than 1200 km. The results illustrate the possibility of a future global quantum communication network.

http://science.sciencemag.org/content/356/6343/1140

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Scientists have solved a centuries-old mystery of "bright nights" - an unusual glow that appears in the sky after dark and lets observers see distant mountains, read a newspaper or check their watch.

Researchers suggest that when waves in the upper atmosphere converge over specific locations on Earth, it amplifies naturally occurring airglow, a faint light in the night sky that often appears green due to the activities of atoms of oxygen in the high atmosphere.

Normally, people do not notice airglow, but on bright nights it can become visible to the naked eye, producing the unexplained glow detailed in historical observations.

Modern observations of bright nights from Earth are practically nonexistent light pollution. Even devoted airglow researchers have never seen a true bright night.

However, even before the advent of artificial lighting, bright nights were rare and highly localised.

Researchers could see bright night events reflected in airglow data from the Wind Imaging Interferometer (WINDII), an instrument once carried by NASA's Upper Atmosphere Research Satellite (1991-2005).

They searched for mechanisms that would cause airglow to increase to visible levels at specific locations.

Airglow comes from emissions of different colors of light from chemical reactions in the upper reaches of the atmosphere. The green portion of airglow occurs when light from the sun splits apart molecular oxygen into individual oxygen atoms.

When the atoms recombine, they give off the excess energy as photons in the green part of the visible light spectrum, giving the sky a greenish tinge.

To find factors that would cause peaks in airglow and create bright nights, researchers searched two years of WINDII data for unusual airglow profiles.

They identified 11 events where WINDII detected a spike in airglow levels that would be visible to the human eye, two of which they describe in detail in the study.

Finally, the researchers matched up the events with the ups and downs of zonal waves, large waves in the upper atmosphere that circle the globe and are impacted by weather.

Comment by Dr. Krishna Kumari Challa on June 15, 2017 at 2:17pm

Update on flourescent light treatment of babies with jaundice  ...

Update

Preemies aren’t the only babies at risk for jaundice. About 60 percent of full-term infants also develop the condition. Severe cases can cause brain damage if untreated. But today, some researchers warn that light therapy, now widely used, may not work for babies whose bilirubin levels are very high. And studies have begun to suggest a link between the therapy and certain childhood cancers . Though the risk of developing cancer is small, doctors should be cautious about prescribing the treatment, researchers wrote in 2016 in Pediatrics.

Phototherapy may slightly increase the risk of cancer in infancy, although the absolute risk increase is small. This risk should be considered when making phototherapy treatment decisions, especially for infants with bilirubin levels below current treatment guidelines.

A.C. Wickremasinghe et al. Neonatal phototherapy and infantile cancer. Pediatrics. Vol. 137, June 2016, e20151353. doi: 10.1542/peds.2015-1353.

Comment by Dr. Krishna Kumari Challa on June 14, 2017 at 8:10am

In a study published in Nature Medicine, researchers have confirmed that the targeted removal of senescent cells can delay the development of osteoarthritis in mice. This research was been led by Dr. Kim Chaekyu of the Johns Hopkins University School of Medicine, who is now at the Ulsan National Institute of Science and Technology (UNIST), and Dr. Jeon Ok Hee of the Johns Hopkins University School of Medicine. In the study, the research team describe a drug candidate that alleviates age-related degenerative joint conditions such as osteoarthritis by selectively destroying senescent cells. Their findings suggest that the selective removal of old cells from joints could reduce the development of post-traumatic osteoarthritis and allow new cartilage to grow and repair joints. 

Local clearance of senescent cells attenuates the development of post-traumatic osteoarthritis and creates a pro-regenerative environment

https://www.nature.com/nm/journal/v23/n6/full/nm.4324.html

Comment by Dr. Krishna Kumari Challa on June 11, 2017 at 9:32am

Contageous Vaccines! Future Perfect! Yes, you read it right!

When enough people get vaccinated, infectious diseases can’t spread easily and everyone benefits from herd immunity. 

But it’s hard to reach enough people for this to happen, especially in areas with poor public health infrastructure. So scientists are taking a leaf from the virus playbook. They’re devising vaccines and antiviral therapies that can spread from host to host.

These transmissible vaccines will likely first be used in animals that carry diseases that can infect people. Some may use a weakened version of the virus, or attach a piece of the pathogen to a benign virus. Other treatments are aimed at people who are already infected and will prey on the virus dwelling in their cells.

It’s early days for these kinds of vaccines and therapies, and scientists still have to show that they are effective and safe to use in wildlife or people. But they could tamp down the spread of HIV and other contagious diseases, and immunize people who would not otherwise be protected. Plus this strategy would be cheaper than vaccinating everyone by hand.

In some countries the vaccine for polio is given as an injection that carries dead poliovirus. But there’s another form of the vaccine that is taken by mouth and uses a weakened—but live—version of the virus. This version can briefly spread to other people before dying out. The World Health Organization has relied on the oral polio vaccine for its efforts to wipe out the disease worldwide.

But there is a drawback. Rarely, the live vaccine can mutate enough to revert back to its virulent form. The oral polio vaccine carries three strains of the virus, one of which has been eradicated in the wild but is also most likely to cause this problem. The WHO is switching to a vaccine that has only the two safer strains.

Many vaccines use live but weakened versions of the virus, including those for measles and chicken pox. The process that disables the virus so it can’t cause sickness also makes it less able to spread.

But it’s likely that some of these vaccines are still a little bit transmissible. This hasn’t been studied in depth, though. When these vaccines are designed, the focus is on making sure they can’t make people sick. 

If we did intentionally design transmissible vaccines, they might be more likely than regular vaccines to revert. That’s because they reach more people and have a chance to replicate and make new generations. That means more chances for mutations and evolution. One way around this would be to make a live vaccine that is only weakly transmissible. This vaccine would only spread a little bit before dying out. This kind of vaccine wouldn’t be able to eradicate a disease, but fewer people would need to be directly vaccinated. A weakly transmissible vaccine would still make a major dent in disease outbreaks.

Source: Popsci

Comment by Dr. Krishna Kumari Challa on June 1, 2017 at 5:08am

We all know that light travels faster than sound. That is why we see lightening first and then hear the sound of thunder later. Light travels roughly 800,000 times as fast as sound.

But an interesting thing about meteors is you can hear the sound and see their light at the same time! How is this possible? Now scientists explained the mystery...

The sound waves aren’t coming from the meteor itself, atmospheric scientists Michael Kelley of Cornell University and Colin Price of Tel Aviv University propose April 16 in Geophysical Research Letters. As the leading edge of the falling space rock vaporizes, it becomes electrically charged. The charged head produces an electric field, which yields an electric current that blasts radio waves toward the ground. As a type of electromagnetic radiation, radio waves travel at the speed of light and can interact with metal objects near the ground, generating a whistling sound that people can hear.

Just 0.1 percent of the radio wave energy needs to be converted into sound for the noise to be audible as the meteor zips by, the researchers estimate. This same process could explain mysterious noises heard during the aurora borealis, or northern lights. Like meteors, auroras have been known to emit radio wave bursts.

On the electrophonic generation of audio frequency sound by meteors

 http://onlinelibrary.wiley.com/doi/10.1002/2017GL072911/abstract

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