Category Health & Medical

WHAT IS AN ORGAN TRANSPLANTATION?

Organ transplantation is a medical procedure in which an organ is removed from one body and placed in the body of a recipient, to replace a damaged or missing organ. The donor and recipient may be at the same location, or organs may be transported from a donor site to another location. Organs and/or tissues that are transplanted within the same person’s body are called autografts. Transplants that are recently performed between two subjects of the same species are called allografts. Allografts can either be from a living or cadaveric source.

Organs that have been successfully transplanted include the heart, kidneys, liver, lungs, pancreas, intestine, thymus and uterus. Tissues include bones, tendons (both referred to as musculoskeletal grafts), corneae, skin, heart valves, nerves and veins. Worldwide, the kidneys are the most commonly transplanted organs, followed by the liver and then the heart. Corneae and musculoskeletal grafts are the most commonly transplanted tissues; these outnumber organ transplants by more than tenfold.

Organ donors may be living, brain dead, or dead via circulatory death. Tissue may be recovered from donors who die of circulatory death, as well as of brain death – up to 24 hours past the cessation of heartbeat. Unlike organs, most tissues (with the exception of corneas) can be preserved and stored for up to five years, meaning they can be “banked”. Transplantation raises a number of bioethical issues, including the definition of death, when and how consent should be given for an organ to be transplanted, and payment for organs for transplantation. Other ethical issues include transplantation tourism (medical tourism) and more broadly the socio-economic context in which organ procurement or transplantation may occur. A particular problem is organ trafficking.[5] There is also the ethical issue of not holding out false hope to patients.

Transplantation medicine is one of the most challenging and complex areas of modern medicine. Some of the key areas for medical management are the problems of transplant rejection, during which the body has an immune response to the transplanted organ, possibly leading to transplant failure and the need to immediately remove the organ from the recipient. When possible, transplant rejection can be reduced through serotyping to determine the most appropriate donor-recipient match and through the use of immunosuppressant drugs.

Credit : Wikipedia 

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WHAT TYPE OF VACCINE IS R21?

Scientists behind the Oxford-AstraZeneca coronavirus shot have produced the vaccine. “This was by far a much more difficult vaccine to make work.” Adrian Hill, the Jenner Institute’s director, said in northern Tanzania on a visit to field trials of the R21/Matrix-M malaria vaccine.

While the coronavirus responsible for Covid-19 has 12 genes, Plasmodium-the parasite that causes malaria – has more than 5,000 genes. It’s an organism that infects the liver and bloodstream, infecting red blood cells.  Hill explains that R21/Matrix-M combines the R21 vaccine with a vaccine booster or adjuvant Matrix-M, which stimulates the human immune system to attack the parasite.  When an infectious mosquito feeds on a human being, it injects parasites in a form called sporozoites into the bloodstream, where they travel directly to the liver. The sporozoites divide rapidly, producing around 20,000 merozoites that rupture the liver cells and invade red blood cells.  R21 targets a circumsporozoite protein (CSP) present on the parasite’s surface during the sporozoite stage. CSP rarely mutates among the four strains of malaria parasites that infect humans. The human body does not readily react with a complete immune response to foreign proteins. The R21 focus on CSP boosted by the proprietary Novavax adjuvant- produces a more robust, better-targeted antibody response.  Clinical trials are now moving to the third phase in four countries across Africa – Mali, Tanzania, Kenya, and Burkina Faso.

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Does blue light from electronic devices damage your eyes?

Staring at your smartphone or any other digital device could speed up blindness. A study by University of Toledo in Ohio (USA) found that blue light from digital devices triggers the production of a toxic chemical that kills light-sensitive cells in our eyes. The resulting damage can speed up macular degeneration – a leading cause of vision loss.

Dr Ajith Karunarathne from the University of Toledo said: “We are being exposed to blue light continuously, and the eye’s cornea and lens cannot block or reflect it. It’s no secret that blue light harms our vision by damaging the eye’s retina.”

Macular degeneration begins with the death of photoreceptor cells (light sensitive cells) in the retina. These cells need molecules called retinal to sense light and trigger a cascade of signalling to the brain. “You need a continuous supply of retinal molecules if you want to see,” Karunarathne said.

When blue light hits our eyes, it triggers retinal to produce toxic molecules that kill off the eye’s photoreceptor cells. “Photoreceptor cells do not regenerate in the eye. When they’re dead, they’re dead for good,” Karunarathne adds.

Retinal and blue light need each other to cause their damage; either one on its own wasn’t found to kill photoreceptor cells. The researchers say that people should avoid using digital devices in the dark because this can dilate pupils and cause more blue light to enter the eyes.

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Can seaweed clean your teeth?

NEWCASTLE University scientists claim that an enzyme isolated from marine bacterium Bacillus licheniformis cuts through plaque on teeth and cleans hard-to-reach areas. Dr Nicholas Jakubovics of the university’s School of Dental Sciences said: “Plaque is made up of bacteria which join together to colonize an area in a bid to push out any potential competitors. Traditional toothpastes work by scrubbing off the plaque containing the bacteria. But that’s not always effective which is why people who religiously clean their teeth can still develop cavities.” When bacterial cells die, the DNA inside leaks out and creates a biofilm that sticks to teeth, protecting the bacteria from brushing, chemicals or even antibiotics. Bacillus licheniformis, found on the surface of seaweed, releases an enzyme which breaks up the biofilm and strips away harmful bacteria.

Researcher Prof. Burgess said: “The zyme breaks up and removes the bacteria esent in plaque and importantly, prevents build-up of plaque too. If we can contain it with’n toothpaste we would be creating a product which could prevent tooth decay. The enzyme also has huge potential in he ping keep clean medical implants such as artificial hips and speech valves which also suffer from biofilm infection.”

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What is Xray day?

November 8 is X-ray Day. X-rays were discovered in 1895 by German physicist Wilhelm Conrad Röntgen, who received the first Nobel Prize for physics in 1901, yet never tried to patent his discovery.

The X-Ray was discovered by accident, as part of an experiment, where Wilhelm was attempting to ascertain whether or cathode rays could pass through glass. Nearby there was a chemically coated screen, and from it was emanating an odd glow, and dubbed the rays causing that glow X-Rays. Why you ask? Because he didn’t know what they were, so the ubiquitous ‘X for unknown’ was utilized. They’ve been called X-Rays ever since.

So what are x-rays really? They’re energy waves of electromagnetism that act in much the same way light rays do, but with an incredibly short wavelength. 1,000 times shorter than those of light to be precise. Once he discovered them, he began experimenting extensively with them, determining what they could and couldn’t pass through, and how they could be photographed. It was through this that he discovered that lead absorbed it almost completely, and human bone would stop it, creating a new and innovative way to see what was going on inside the human body.

X-Rays were used extensively during the Balkan War to locate shrapnel, bullets, and broken bones in soldiers in the field. X-Rays were used extensively in things like shoe-fittings until it became apparent that it wasn’t all fun and games. Now they’re used for things like security at airports, material analysis, and more, but with much more attention to safety.

The best way to celebrate World Radiography Day is to research X-Rays and what they’ve done for us. Then you can sit down and try to think of all the different ways that x-rays are used in modern living.

Credit :  Days of the year

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What is pollen allergy?

Allergic reactions can happen around the year, but people who are prone to pollen allergy experience severe bouts of it during spring and summer, when trees, plants grasses, and weeds release tiny pollen particles into the air to fertilize other plants. And this particular time of the year is often referred to as the ‘allergy season.

A new research from Germany suggests that climate change is causing allergy season to last longer, as rising temperatures are causing plants to bloom earlier, and pollen from early blooming locations are travelling to later blooming locations. This means more days of itchy eyes and runny noses for people with pollen allergy.

Researchers found that certain species, such as hazel shrubs and alder trees, advanced the start of their season by up to 2 days per year, over a period of 30 years (between 1987 and 2017). Other species, which tend to bloom later in the year, such as birch and ash trees, advanced their season by 0.5 days on average each year.

The effects of climate change on the pollen season have been studied at length. It has been established that greenhouse gas emissions and weather variables, mainly air temperature, sunlight and rainfall, are affecting plant phenology – the timing of plant life-cycle events, such as flowering, fruiting and pollen production.

Pollen travels

Climate change has had a negative impact on the movement of pollen and atmospheric pollen concentration. The changing weather patterns and atmospheric circulation may spread pollen to new areas and expose people to different allergens their immune systems are unprepared for. Such pollen movement can also introduce invasive species into new environments.

 

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