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Comment by Dr. Krishna Kumari Challa on April 12, 2018 at 8:17am

Scientists here say Dog is a biodiversity enemy

According to a new study, Canis lupus familiaris (dog, for short) is  an ‘invasive’ species in many ecosystems! Like the Japanese kudzu vine or the infamous Lantana, dogs are a non-native introduced species that are wreaking havoc on the ecological balance of many sensitive ecosystems. Now, a study by researchers from the Ashoka Trust for Research in Ecology and the Environment explores the effect of free-ranging dogs, or strays, on their surroundings in India.

Previous studies have shown that domesticated dogs have imperilled 188 threatened species of animals and caused 11 mass extinctions, globally! Domestic dogs have been considered as invasive mammalian predators. After cats and rodents, they are the third most damaging invasive predators.

In countries like India, where the population of stray dogs are surging by the day without checks and bounds by a governing body, these dogs turn feral—a state in which they are neither truly wild not truly domesticated. “Unlike cats and rats which perhaps target smaller sized animals, feral dogs can target a larger range of prey size as predators as they can hunt in packs. Their impacts are as detrimental as cats and rats, though cats and rats have reported higher extinction for biodiversity.

The study shows that the threat from dogs on wildlife is real and could come in the way of conservational efforts. So, what can we do to curb this conflict? Managing dog population is the key, say the researchers.

 The researchers opine that in order to protect local wildlife and ensure a good quality of life for dogs, carefully planned population control programs should be implemented near protected forest areas.

Domesticated dogs are adding a new dimension to the threats many species of wildlife are already facing due to habitat loss, deforestation, encroachment, etc. Man’s best friend is turning out to be biodiversity’s biggest enemy, as this research shows.

https://zslpublications.onlinelibrary.wiley.com/doi/abs/10.1111/acv...

Comment by Dr. Krishna Kumari Challa on April 10, 2018 at 3:03pm

Eating very hot chillies might trigger reversible cerebral vasoconstriction syndrome — a temporary narrowing of arteries in the brain.

His is the first known instance of reversible cerebral vasoconstriction syndrome — a temporary narrowing of arteries in the brain — to be tied to eating a hot pepper, researchers report April 9 in British Medical Journal Case Reports. Such narrowed arteries can lead to severe pain called “thunderclap headaches” and are often associated with pregnancy complications or illicit drug use.

During a hot-pepper-eating contest, the man ate a chili dubbed the Carolina Reaper, named by Guinness World Records as the hottest pepper in the world. The Carolina Reaper is over 200 times as spicy as a jalapeño. About a minute later, he reported experiencing splitting headaches that came and went over two days before he sought treatment.

Initial tests failed to find anything out of the ordinary. But a CT scan of blood vessels in the man’s brain showed severely narrowed arteries. After treatment, including hydration and pain medication, the headaches stopped. When the researchers imaged his brain five weeks later, the arteries had returned to their normal size.

 http://casereports.bmj.com/content/2018/bcr-2017-224085

Comment by Dr. Krishna Kumari Challa on April 5, 2018 at 8:40am

Cancer is a dreaded disease. And chemotherapy has its pitfalls but becomes unavoidable sometimes. But how about making chemotherapy more safer and effective?

That is exactly what researchers at the Indian Institute of Technology Kanpur have proposed - a new model for the transport of anti-cancer drugs to human brain tumours using liposomes—a small sac-like structure that transports nutrients in our cells. 

Liposomes, like our cell membranes, are made of molecules called phospholipids. In a cell membrane, these molecules are arranged into two layers. However, in a liposome, the two layers meet to form a hollow sphere filled with water. In this study, the researchers propose to replace the water in the empty area with anti-cancer drug molecules—a technique they claim improves transport of the drug molecules—to create a nanosized drug delivery system.

Besides, the lipid layer in the liposomes acts as a protective coat and prevents the anti-cancer drug from affecting healthy cells. Since these liposomes are in the bloodstream, they circulate for longer and collect at the tumour site, helping more of the drug reach their target cells. This approach causes less damage to the healthy cells of the body.

There is another aspect of tumours that makes it hard to use anti-cancer drugs in treatment without damaging the surrounding healthy cells. Tumorous cancer cells vary in their organisation, function and structure, making it difficult for drugs to target them specifically.  Also, the veins and arteries that supply blood to a tumour, twist and coil, making it more difficult to administer the anti-cancer drug into a tumour. Since the endothelial cells present in the tumour blood vessels are widely spaced out, drugs tend to leak out into the interstitial spaces between the cells, reducing the efficacy of the drugs.

The researchers analysed the structure of blood vessels of the cancerous brain tissue using dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) by taking multiple snapshots of the tumor vasculature over a period of time and comparing them. Using this data, they predicted the transport, accumulation and efficacy of the chemotherapeutic drug in a tumour with computational fluid dynamics—a branch of fluid mechanics that uses numerical analysis and data structures to solve and analyse problems that involve fluid flows. They also predicted the distribution of the drug in a tumour. “With the help of this model, we can predict the preferential deposition of chemotherapeutic drugs inside a tumour, thus predicting the healing of a tumour for a specific patient, provided we have the initial medical images of that patient".

The results of the study showed that a high amount of the anti-cancer drug Doxorubicin, which was not encapsulated by a liposome, accumulated in the interstitial spaces between tumour cells. This accumulation could potentially cause adverse side-effects like swelling, reddening and peeling of skin from the hands and feet. In contrast, the liposome-encapsulated drug remained inside a tumour for a longer time. They also found that the high concentration of liposome-coated drug aggregated at the tumour site and increased the therapeutic efficiency of the liposomal anticancer drug.

Medical imaging of the tumours helps predict the deposition of the anti-cancer drug in a tumour for a patient and look for chemotherapeutic drug options that could better suit him/her. This ability also allows doctors to develop a specific chemotherapeutic approach for each patient, based on the structure of their brain tumour and the blood vessels surrounding it.

http://biomechanical.asmedigitalcollection.asme.org/article.aspx?ar...

Comment by Dr. Krishna Kumari Challa on March 14, 2018 at 9:36am

World renowned physicist Stephen Hawking has died at the age of 76.

He died peacefully at his home in Cambridge in the early hours of Wednesday, his family said.

The Briton was known for his work with black holes and relativity, and wrote several popular science books including A Brief History of Time.

At the age of 22 Prof Hawking was given only a few years to live after being diagnosed with a rare form of motor neurone disease.

Comment by Dr. Krishna Kumari Challa on March 14, 2018 at 9:01am

Newer drugs make hepatitis C-positive kidneys safe for transplant

Improved antivirals could help expand the number of organs available for donation

People who received kidneys from donors infected with hepatitis C did not become ill with the virus, thanks to treatment with newer drugs that can cure the disease, a small study reports.

Ten patients not previously infected with hepatitis C took doses of powerful antiviral medications before and after receiving the transplants. None of the patients developed chronic infections, researchers report online March 6 in the Annals of Internal Medicine. The finding could help make more kidneys available for transplants.

C. Durand et al. Direct-acting antiviral prophylaxis in kidney transplantation from .... Annals of Internal Medicine. Published online March 6, 2018. doi:10.7326/M17-2871.

Comment by Dr. Krishna Kumari Challa on March 12, 2018 at 6:55am

Space travel changes your DNA. How much of that is permanent?

When Scott Kelly came back from his 342-day mission on International Space Station, the initial findings revealed that his telomeres lengthened in space, but shortened in just two days following his return to Earth. These findings suggest that genetic changes are temporary and DNA returns to normal after the passage of some time. NASA used two astronauts, Mark and Scott Kelly, since they were twins and shared the same DNA, this made things easier for the space agency to find out the differences or in other word how space affected human body. 

While it’s possible for the DNA differences to be a temporary effect on the human body, NASA’s findings reveal otherwise. Approximately 7 percent of Scott Kelly’s DNA changed while he was in space. So, 7 percent of his DNA was altered permanently, while the remaining 93 percent reverted to normal as his body adapted to living on Earth.

Comment by Dr. Krishna Kumari Challa on March 11, 2018 at 7:20am

Comment by Dr. Krishna Kumari Challa on March 2, 2018 at 9:18am

According to new research diabetes could be five  separate types.

The results, published in The Lancet Diabetes and Endocrinology, showed the patients could be separated into five distinct clusters.

• Cluster 1 - severe autoimmune diabetes is broadly the same as the classical type 1 - it hit people when they were young, seemingly healthy and an immune disease left them unable to produce insulin
• Cluster 2 - severe insulin-deficient diabetes patients initially looked very similar to those in cluster 1 - they were young, had a healthy weight and struggled to make insulin, but the immune system was not at fault
• Cluster 3 - severe insulin-resistant diabetes patients were generally overweight and making insulin but their body was no longer responding to it
• Cluster 4 - mild obesity-related diabetes was mainly seen in people who were very overweight but metabolically much closer to normal than those in cluster 3
• Cluster 5 - mild age-related diabetes patients developed symptoms when they were significantly older than in other groups and their disease tended to be milder

This new classification makes treatment better and scientists think treating these groups differently would produce better outcomes.

Comment by Dr. Krishna Kumari Challa on February 10, 2018 at 9:22am

Lichens redefined...

For 150 years, scientists believed lichen were defined by a symbiotic relationship between a fungus and algae. The fungus provides structure and support for the organism, while the algae produces food through photosynthesis. However, researchers recently discovered that certain lichen have an additional fungus in the mix. This threesome was revealed after a team set out to explain what made one type of lichen toxic versus another that was seemingly identical.

Lichens may be a symbiosis of three organisms!

http://science.sciencemag.org/content/early/2016/07/20/science.aaf8287

Comment by Dr. Krishna Kumari Challa on February 10, 2018 at 8:50am

Sunday, 11 February, is the International Day of Women and Girls in Science.

In order to achieve full and equal access to and participation in science for women and girls, and further achieve gender equality and the empowerment of women and girls, the United Nations General Assembly adopted resolution A/RES/70/212 declaring 11 February as the International Day of Women and Girls in Science.

http://www.un.org/en/events/women-and-girls-in-science-day/

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