Knowledge Update

​New York, April 11 (IANS) US doctors, including an Indian American doctor reported the first case of a human patient whose severely damaged oesophagus was reconstructed using commercially available stents and skin tissues.

After the 24-year-old man was paralysed in a car crash seven years ago, doctors struggled to repair his disrupted oesophagus.

Despite several surgeries, the defect in the oesophagus was too large to repair and it was resulting in life-threatening infection, the physicians noted in the paper published in the journal in The Lancet.

The team of doctors decided to try a technique previously tested only in animals, to reconstruct the upper oesophagus with stents and skin tissue approved by the US Food and Drug Administration.

"This is a first in human operation and one that we undertook as a life-saving measure once we had exhausted all other options available to us and the patient,” Kulwinder Dua, professor at Medical College of Wisconsin in the US. 

The doctors used metal stents as a non-biological scaffold and a regenerative tissue matrix from donated human skin to rebuild a full-thickness five cm defect in the oesophagus of the patient.

They inserted an endoscope containing a wire through the man's stomach and up through what remained of his oesophagus, leading to his mouth. 

Guided by the wire, they then inserted three stents to recreate the structure of the oesophagus and covered it with skin tissue. 

The tissue was then sprayed with a gel made from the patient's own blood, which contained natural substances to attract stem cells.

Although the doctors wanted to remove the stents about three months after the surgery, the patient refused, fearing he would not be able to eat and drink; he was also worried about possible scarring. 

Nearly four years later, doctors removed the stents after the man had trouble swallowing when a problem arose with the lower stent.

One year after that, doctors examined the man's oesophagus and found that all five layers of the oesophagus had regrown, closely resembling a normal one. 

The patient now does not need a feeding tube and also has not reported any other complications.

Swallowing tests showed full recovery and functioning was also established with oesophageal muscles able to propel water and liquid along the oesophagus into the stomach in both upright and 45 degrees sitting positions.

"The approach we used is novel because we used commercially available products which are already approved for use in the human body and hence didn't require complex tissue engineering," Dua explained.

The research including animal studies and clinical trials, are now needed to investigate whether the technique can be reproduced and used in other similar cases.

“The use of this procedure in routine clinical care is still a long way off as it requires rigorous assessment in large animal studies and phase one and two clinical trials," Dua stated.

The oesophagus is a hollow muscular tube that connects the mouth to the stomach carrying food and liquids.

​Canberra, April 11 (IANS) The number of tigers in the wild has risen for the first time in 100 years, marking a major turning point in the big cat's plight against poaching and habitat loss.

Figures collated from national surveys conducted in tiger range states and from the International Union for Conservation of Nature (IUCN), estimate the number of tigers living in the wild to be around 3,890.

That is up almost 700 animals from the 2010 figure, which estimated their numbers at 3,200, ABC reported.

Current tiger estimates across Asia are: 2,226 tigers in India, 433 in Russian Siberia, 371 in Indonesia, 250 in Malaysia, 198 in Nepal, 189 in Thailand, 106 in Bangladesh, 103 in Bhutan, more than seven in China, less than five in Vietnam, two tigers in Laos, and none in Cambodia. Data on tigers in Myanmar was not available.

The World Wildlife Fund (WWF) Australia's national manager for the species, Darren Grover welcomed the news, saying it was the first increase since the turn of the 20th century.

"That's great news. It's the first positive trend for wild tiger populations in more than 100 years," he said.

In 1900, approximately 100,000 tigers were estimated to be living in the wild.

"In those 100 years or so, we've lost around 97 percent of wild tigers," Grover said.

A WWF background document said the increase was likely the result of major changes made in India, Russia, Nepal and Bhutan, including improved survey techniques and ramped up conservation efforts.

But despite the increase, Grover said there was still a long way to go before tiger range states reached their goal of doubling the number in the wild by 2022.

In 2011, about 14 countries from across the tiger range, which extends from India across South Asia and to Far East Russia, got together in St. Petersburg in Russia and agreed to the Tx2 target.

"They took 3,200 as the number at that time, so that would mean they are aiming for a wild tiger population of around 6,400 by 2022," Grover said.

"We're on the way towards that target. We're obviously making progress, but there is still quite some way to go."

Grover said some countries, such as Malaysia, China and Thailand, were holding back efforts by failing to conduct habitat surveys.

"There is some information available on how many tigers remain in those countries, but until we do those accurate surveys, we won't know for sure," he said.

"The good thing is, most of those countries have committed to doing those surveys over the next year or so, so that will enlighten us to a more accurate figure and hopefully show that that overall number is increasing further."

He said in the meantime, tourists needed to be aware of the overseas practices threatening tigers in the wild.

"While loss of habitat has been a major reason for the decline in tiger numbers, the illegal poaching of tiger and the use of products in traditional medicines is also a major factor behind the decline in tiger populations," he said.

"We really urge people who are going to these countries, if you're in markets and you are seeing what are claimed to be tiger products, don't purchase them."

"As we like to say, there's only one place where those tiger products should be, and that's in a tiger."​

London, April 11 (IANS) In a first, researchers have shown that ribose - a sugar that is one of the building blocks of genetic material in living organisms - may have formed in ice on comets.

The genetic material of all living organisms on Earth, as well as of viruses, is made up of nucleic acids, DNA and RNA. 

Scientists have long wondered about the origin of these biological compounds. 

Some believe that the Earth was seeded by comets or asteroids that contained the basic building blocks needed to form such molecules. 

Ribose, the other key component of RNA, had never yet been detected in extraterrestrial material or created in the laboratory under “astrophysical” conditions. 

Now, by simulating the evolution of the interstellar ice making up comets in the lab, French research teams have successfully obtained ribose - a key step in understanding the origin of RNA and of life.

To obtain this result, scientists at the Institut de Chimie de Nice, University of Nice-Sophia Antipolis, in France carried out a highly detailed analysis of an artificial comet.

The astrophysicists simulated the formation of dust grains coated with ice, the raw material of comets. 

They then proposed the first realistic scenario for the formation of this key compound which had never been detected in meteorites or cometary ices until now. 

Although the existence of ribose in real comets remains to be confirmed, this discovery completes the list of the molecular building blocks of life that can be formed in interstellar ice. 

“It also lends further support to the theory that comets are the source of the organic molecules that made life possible on Earth, and perhaps elsewhere in the universe,” the authors noted in a paper published in the journal Science.​

​London, April 12 (IANS) e-cigarette smoking is increasingly promoted as a safer alternative to cigarette smoking but a team of researchers has found that e-cigarettes have immediate effects on pulmonary function in mild asthmatic young smokers.

The findings showed that e-cigarette smoking caused acute pulmonary function impairment, lasting for less than 30 minutes after smoking.

"The results show that as it happens with cigarette smoking, e-cigarette smoking has more deleterious short-term effects on asthmatics compared with healthy smokers," said Andreas Lappas from the Hellenic Cancer Society in Athens, Greece. 

In a study, published in the journal CHEST, of 54 young cigarette and e-cigarettes smokers aged 18-31, 27 had mild controlled asthma and the other 27 were healthy. 

The results suggest that measurements of airway obstruction and inflammation were worse after e-cigarette sessions and these findings were more severe in asthmatics.

"It adds to the growing body of research pointing to the dangers of e-cigarettes. Especially for asthma, further research is needed in order to assess the risks of long-term e-cigarette use," Lappas added.

The study is set to be presented at the "CHEST World Congress 2016" in Shanghai, China, on April 15-17. ​

New York, April 12 (IANS) A team of scientists has discovered six new proteins that may help reveal secrets of how humans age -- potentially unlocking new insights into diabetes, Alzheimer's disease, cancer and other ageing-related problems.

The researchers found that these tiny proteins are produced naturally in the energy-generating mitochondria -- the powerhouse in human cells -- and play key roles in metabolism and cell survival.

"The findings are an important advance that will be ripe for rapid translation into drug development for diseases of ageing," said lead researcher Pinchas Cohen from University of Southern California in the US.

The amount of each protein decreases with age, leading to onset of diseases linked to older age.

To learn further, the team used computer analysis and uncovered the genes for six new proteins which were dubbed small humanin-like peptides (SHIP).

"The newly recognised SHLP family expands the understanding of the mitochondria as an intracellular signalling organelle that communicates with the rest of the body to regulate metabolism and cell fate," Cohen explained.

After identifying the six new proteins and successfully developing antibodies to test for several of them, the researchers examined both mouse tissues and human cells to determine their abundance in different organs as well as their functions. 

The proteins were distributed quite differently among organs, suggesting that the proteins have varying functions based on where they are in the body.

The results revealed that these tiny proteins plays several big roles in our bodies' cells, from decreasing the amount of damaging free radicals and controlling the rate at which cells die to boosting metabolism and helping tissues throughout the body respond better to insulin. ​

Toronto, April 12 (IANS) An incidence of brain injury in a child can have adverse effects on the quality of relationships shared between the parent and the child, finds a study.

The findings revealed that concussion or mild traumatic brain injury (mTBI) is particularly high in the preschool years -- up to around 2 percent of children aged 0 to 5 years per year. 

"The young brain is particularly vulnerable to injury because the skull is still thin and malleable. In the months following the injury, one of the first visible signs of social difficulties in young children is a decline in their relationship with their parents," said one of the researchers, Miriam Beauchamp, professor at University of Montreal in Canada.

Given the relatively limited social and cognitive skills of preschoolers, a concussion at this age can slow the development of new abilities, for example, certain communication skills. 

“It may be due to specific neurological mechanisms, to changes in parenting, or to stress caused by the injury," said lead author Gabrielle Lalonde, doctoral student at University of Montreal.

The study published in the Journal of Neuropsycholog, aims to assess the quality of parent-child interactions six months post-injury. 

The team recruited a group of 130 children aged between 18 months and 60 months and divided them into three categories: children with concussion, children with orthopedic injury (usually a fracture or sprain of the arm or leg) but no concussion, and a control group of non-injured children. 

The results revealed that the quality of parent-child interactions of injured children following concussion was significantly reduced compared to non-injured children.

Parents should monitor behaviour changes in their child in the weeks that follow the trauma and adjust accordingly during this period.

"If, as parents, you notice the effects of the accident on your own psychological state, or behavioural changes in your child that make them interact differently and that persist more than a few weeks, you should talk to your family doctor or a neuropsychologist," Beauchamp suggested.

​Seoul, April 10 (IANS) Are you a self-obsessed person and love to click selfies? Korean researchers have found that narcissist are more likely to show selfie-posting behaviour on social networking sites such as Facebook as well as evince great interest in the feedback they receive.

A narcissistic personality is a mental disorder in which people have an inflated sense of their own importance, a deep need for admiration and a lack of empathy for others.

"Across all social media technologies, narcissists (as compared to non-narcissists) tend to engage in more self-enhancement strategies in hopes of gaining admiration," said Brenda K. Wiederhold from Virtual Reality Medical Institute, Brussels, Belgium.

According to researchers, the involvement in comments received to their own selfies and their interest in other people's selfies did not; however mean that they were more likely to provide feedback.

The authors describe the link between degree of narcissism and self-promotion through selfies published in the journal Cyberpsychology, Behaviour, and Social Networking.

Individuals with a higher degree of narcissism have a more favourable attitude towards the act of posting selfies, said Jung-Ah Lee and Yongjun Sung from Korea University found

"However, since narcissism does not completely explain selfie posting, future studies are needed to uncover additional psychological or social factors that influence selfie posting behaviour," Wiederhold added.​

​New York, April 12 (IANS) Children's exposure to higher levels of air pollution, including fine particulate matter also known as PM2.5, and impure carbon particles can most negatively impact their lung functioning, finds a new study.

The findings showed that by the time a child reaches the age of eight, his or her lungs are greatly affected by inhaling the PM2.5 that includes aerosols, smoke, fumes, dust, ash and pollen as well as black carbon. 

Also, children living the closest to major highways had the greatest reductions in their lung function.

The lung functioning of children living within 100 meters of a major roadway was on average 6 percent lower than that of children living 400 meters or more away, said the lead author Mary B. Rice, instructor at Harvard Medical School in US.

For the study, published in the American Journal of Respiratory and Critical Care, the team studied 614 children born between 1999 and 2002.

They calculated the distance from the child's home to the nearest major highway, and estimated first year of life, lifetime and prior-year exposure to PM2.5, using satellite measurements​

​Toronto, April 10 (IANS) Cancerous tumour cells expand in the human body by feeding on "bad cholesterols" found in the lipid metabolism, finds a new research.

Tumour cells grow as a result of scavenging on very low-density lipoproteins (VLDL) and low-density lipoproteins (LDL) -- commonly known as "bad cholesterol" -- in the body.

The findings of the clinical trials showed that minimising the liver's production of LDL would deprive a tumour from its constant supply and therefore reduce its possibility of growth.

Tumours not only use lipids as "building blocks" to grow, but they can regulate their host's lipid metabolism to increase production of these lipids.

The "bad cholesterol" binds to LDL receptors in the liver, the organ in charge of degrading it and excreting it from the organism as bile.

"Cancer cells need lipids to grow. They can make their own lipids or get more from the host because these cells grow so fast," explains Richard Lehner, professor at University of Alberta in Canada.

Proteins are identified as one of the key factors for this process, which may cause a decrease in the amount of LDL receptors to excrete the cholesterol.

The tumour affects these proteins to reduce clearance of cholesterol from the blood, leaving the LDL for cancer to feed off of it.

The study, published in the journal Cell Reports, explores mechanisms that can be used to reduce the malignant cells' growth.

Should these potential clinical trials prove to be effective, we could be facing an improved way to help cancer patients: eliminating the tumour, while preventing it from growing at the same time, the researchers concluded.​

London, April 13 (IANS) A team of British researchers has found that people with type 2 diabetes are at a greater risk of serious liver disease than those without the condition.

“We have shown for the first time that type 2 diabetes is an important novel risk factor that increases numbers of hospital admissions and deaths, in people with all common chronic liver diseases," said Chris Byrne, a professor at the University of Southampton. 

"Further research is now needed to determine whether all patients with type 2 diabetes should be screened for common chronic liver diseases,” he added.



The team, involving researchers from the universities of Southampton and Edinburgh, examined cases of liver diseases among people with diabetes from anonymised, securely linked hospital records and death records in Scotland over a 10-year period.

They found that most cases of liver disease in people with type 2 diabetes are not alcohol-related but caused by a build-up of fat within liver cells - a condition known as non-alcoholic fatty liver disease (NAFLD), according to a the study published recently in the Journal of Hepatology.

NAFLD is commonly linked to obesity, which is also a risk factor for type 2 diabetes.

Most people can avoid getting these conditions by following a healthy diet and taking regular exercise.

“Preventing non-alcoholic fatty liver disease by avoiding unhealthy lifestyles in both people with and without diabetes is important because it is difficult to treat the complications of this condition,” said Sarah Wild from the University of Edinburgh.

The research team found that men with type 2 diabetes are three times more likely to suffer from NAFLD than men without diabetes.

There are fewer cases of type 2 diabetes and liver disease amongst women but having type 2 diabetes increases the risk of NAFLD by five times, the study found.

People with NAFLD are more susceptible to the effects of alcohol on the liver and should avoid drinking to avoid further complications, the researchers said.​