Reducing oxygen levels may cure jet lag: study

October 21, 2016

Jerusalem, Oct 21: Reducing oxygen levels in an aeroplane cabin may help combat jet lag in travellers, suggests a new study which found that variation in oxygen levels can reset circadian clocks of mice and help them adapt eating, sleeping and running habits to the new time faster.

jetlagPresently, light, food and temperature are the best known cues that can influence circadian rhythms.

Lead author Gad Asher, scientist at the Weizmann Institute of Science in Israel, and his colleagues studied that changing the concentration of oxygen in cells by just 3 per cent, twice a day, will synchronise mouse cells to a circadian rhythm.

They suspected protein HIF1a was the link between oxygen and the circadian clock because HIF1a plays both a role in oxygen homeostasis in cells.

They found that cells with low HIF1a levels will not synchronise in response to oxygen variations.

"It was extremely exciting to see that even small changes in oxygen levels were sufficient to efficiently reset the circadian clock," said Asher.

Researchers further explored oxygen's effect on circadian rhythms with jetlag experiments. Just like humans, mice are prone to jetlag after a sudden shift in daylight hours.

Mice were first left to eat, sleep and run on their wheels in air-controlled environments.

Altering oxygen levels alone did not change their circadian rhythms but once mice experienced a six-hour jump ahead in daylight hours, varying oxygen levels could help them adapt their eating, sleeping and running habits to the new time faster.

They also saw that a small drop in oxygen levels 12 hours before the six-hour daylight shift, or two hours afterwards, put the mice back on their circadian schedules faster and this too was dependent on HIF1a levels.

Presently, commercial airliners pressurise cabins to the same air density of a city 6,000-8,000 feet above sea level.

This low-pressure saves wear and tear on the airplane, but enough passengers suffer from airsickness in response to this drop in oxygen levels that some airlines are considering ways to increase the pressure on flights.

Researchers noted that passengers may feel better with higher pressurised cabins during flights, but may also lose a potential advantage of recovering from jetlag.

Understanding how oxygen influences the circadian clock goes beyond jetlag. Cardiovascular disease, COPD, shift work sleep disorder, and other common health problems can result in tissues with low oxygen levels.

"We show that oxygen works in mammals, specifically rodents, but it will be interesting to test whether oxygen can reset the clock of bacteria, plants, flies and additional organisms," said Asher.

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News Network
March 5,2020

Bergen, Mar 5: Divorce of parents may impact the academics of children negatively, suggests a new study.

According to the study, parental divorce is associated with a lower grade point average (GPA) among adolescents, with a stronger association seen in teens with more educated mothers.

The study was published in the journal PLOS ONE.

Children and adolescents with divorced or separated parents are known to do less well in school than adolescents with nondivorced parents and to be less well-adjusted, on average, across a spectrum of physical and mental health outcomes.

In the new study, researchers used data from the youth@hordaland study, a population-based survey of adolescents aged 16-19 conducted in the spring of 2012 in Hordaland County, Norway.

19,439 adolescents were invited to participate and 10,257 agreed; of those, 9,166 are included in the current study.

Overall, adolescents with divorced parents had a 0.3 point lower GPA (standard error 0.022, p<0.01) than their peers.

Controlling for parental education reduced the effect by 0.06 points to 0.240 (SE 0.021, p<0.01). This heterogeneity was predominantly driven by maternal education levels, the researchers found.

After controlling for paternal education and income measures, divorce was associated with a 0.120 point decrease in GPA among adolescents whose mothers had a secondary school education level; a 0.175 point decrease when mothers had a Bachelor's level education; and a 0.209 point decrease when mothers had a Master's or PhD level education (all estimates relative to adolescents with a mother who had a basic level of education, such as ISCED 0-2).

Due to the cross-sectional structure of the study, researchers could not investigate specific changes between pre- and post-divorce family life, and future studies are needed to investigate potential mechanisms (such as reduced parental monitoring or school-involvement) which might drive this finding.

Nonetheless, this study provides new evidence that the negative association between divorce and teens' GPA is especially strong in families with more educated mothers.

"Among Norwegian adolescents, parental divorce was hardly associated with GPA among youth whose parents have low educational qualifications. In contrast, among adolescents with educated or highly educated mothers, divorce was significantly associated with lower GPA," said the authors.

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News Network
May 13,2020

California, May 13: A fasting-mimicking diet could be more effective at treating some types of cancer when combined with vitamin C, suggests a new study conducted by the scientists from USC and the IFOM Cancer Institute in Milan.

In studies on mice, researchers found that the combination delayed tumour progression in multiple mouse models of colorectal cancer; in some mice, it caused disease regression. The results were published in the journal Nature Communications.

"For the first time, we have demonstrated how a completely non-toxic intervention can effectively treat an aggressive cancer," said Valter Longo, the study senior author and the director of the USC Longevity Institute at the USC Leonard Davis School of Gerontology and professor of biological sciences at the USC Dornsife College of Letters, Arts and Sciences.

"We have taken two treatments that are studied extensively as interventions to delay ageing-- a fasting-mimicking diet and vitamin C -- and combined them as a powerful treatment for cancer," added Longo.

The researchers said that while fasting remains a challenging option for cancer patients, a safer, more feasible option is a low-calorie, plant-based diet that causes cells to respond as if the body were fasting.

Their findings suggest that a low-toxicity treatment of fasting-mimicking diet plus vitamin C has the potential to replace more toxic treatments.

Results of prior research on the cancer-fighting potential of vitamin C have been mixed. Recent studies, though, are beginning to show some efficacy, especially in combination with chemotherapy.

In this new study, the research team wanted to find out whether a fasting-mimicking diet could enhance the high-dose vitamin C tumour-fighting action by creating an environment that would be unsustainable for cancer cells but still safe for normal cells.

"Our first in vitro experiment showed remarkable effects. When used alone, fasting-mimicking diet or vitamin C alone reduced cancer cell growth and caused a minor increase in cancer cell death. But when used together, they had a dramatic effect, killing almost all cancerous cells," said Longo.

Longo and his colleagues detected this strong effect only in cancer cells that had a mutation that is regarded as one of the most challenging targets in cancer research.

These mutations in the KRAS gene signal the body is resisting most cancer-fighting treatments, and they reduce a patient's survival rate. KRAS mutations occur in approximately a quarter of all human cancers and are estimated to occur in up to half of all colorectal cancers.

The study also provided clues about why previous studies of vitamin C as a potential anticancer therapy showed limited efficacy. By itself, a vitamin C treatment appears to trigger the KRAS-mutated cells to protect cancer cells by increasing levels of ferritin, a protein that binds iron.

But by reducing levels of ferritin, the scientists managed to increase vitamin C's toxicity for the cancer cells. Amid this finding, the scientists also discovered that colorectal cancer patients with high levels of the iron-binding protein have a lower chance of survival.

"In this study, we observed how fasting-mimicking diet cycles are able to increase the effect of pharmacological doses of vitamin C against KRAS-mutated cancers," said Maira Di Tano, a study co-author at the IFOM, FIRC Institute of Molecular Oncology in Milan, Italy.

"This occurs through the regulation of the levels of iron and of the molecular mechanisms involved in oxidative stress. The results particularly pointed to a gene that regulates iron levels: heme-oxygenase-1," added Tano.

The research team's prior studies showed that fasting and a fasting-mimicking diet slow cancer's progression and make chemotherapy more effective in tumour cells while protecting normal cells from chemotherapy-associated side effects. The combination enhances the immune system's anti-tumour response in breast cancer and melanoma mouse models.

The scientists believe cancer will eventually be treated with low-toxicity drugs in a manner similar to how antibiotics are used to treat infections that kill particular bacteria, but which can be substituted by other drugs if the first is not effective.

To move toward that goal, they say they needed to first test two hypotheses: that their non-toxic combination interventions would work in mice, and that it would look promising for human clinical trials.

In this new study, they said that they've demonstrated both. At least five clinical trials, including one at USC on breast cancer and prostate cancer patients, are now investigating the effects of the fasting-mimicking diets in combination with different cancer-fighting drugs.

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Agencies
July 5,2020

The deadly coronavirus that entered India while there was still nip in the air has beaten rising mercury, humid conditions, unique Indian genome and has entered monsoon season with more potency as fresh cases are only breaking all records in the country.

India recorded a single-day spike of record 24,850 new coronavirus cases on Sunday, taking its total tally to 6.73 lakh corona-positive cases.

Top Indian microbiologists were hopeful in March that after the 21-day lockdown, as summer approaches, the rise in temperature would play an important role in preventing the drastic spread of COVID-19 virus in India.

Several virologists hinted that by June this year, the impact of COVID-19 would be less than what it appeared in March-April.

The claims have fallen flat as the virus is mutating fast, becoming more potent than ever.

According to experts, the novel coronavirus is a new virus whose seasonality and response to hot humid weather was never fully understood.

"The theory was based on the fact that high temperatures can kill the virus as in sterilisation techniques used in healthcare. But these are controlled environment conditions. There are many other factors besides temperature, humidity which influence the transmission rate among humans," Dr Anu Gupta, Head, Microbiologist and Infection Control, Fortis Escorts Heart Institute, told IANS.

There is no built-up immunity to COVID-19 in humans.

"Also, asymptomatic people might be passing it to many others unknowingly. New viruses tend not to follow the seasonal trend in their first year," Gupta emphasized.

Globally, as several countries are now experiencing hot weather, the World Health Organization (WHO) reported a record hike in the number of coronavirus cases, with the total rising by 2,12,326 in 24 hours in the highest single-day increase since COVID-19 broke out.

So far over 11 million people worldwide have tested positive for the disease which has led to over 5,25,000 deaths, according to data from Johns Hopkins University. The US remained the worst-hit country with over 28 lakh cases, followed by Brazil with 15.8 lakh.

According to Sandeep Nayar, Senior Consultant and HOD, Respiratory Medicine, Allergy & Sleep Disorders, BLK Super Speciality Hospital in New Delhi, whether temperature plays a role in COVID-19 infection is highly debated.

One school of thought said in the tropical regions of South Asia, the virus might not thrive longer.

"On the other hand, another school of thought has found that novel Coronavirus can survive in a hot and humid environment and tropical climate does not make a difference to the virus. According to them, this is what distinguishes the novel coronavirus from other common viruses, which usually wane in hot weather," stressed Nayar.

Not much has been studied in the past and no definite treatment or vaccine is available to date.

"Every day, new properties and manifestation of the disease come up. As of now, the only way to prevent this monster is by taking appropriate precautions. Hand hygiene, social distancing, cough etiquette and face masks definitely reduce spread of COVID-19 infection," Nayar told IANS.

Not just top Indian health experts, even Indian-American scientists had this theory in mind that sunshine and summer may ebb the spread of the coronavirus.

Ravi Godse, Director of Discharge Planning, UPMC Shadyside Pennsylvania in the US told IANS in April: "In the summer, the humidity can go up as well, meaning more water drops in the air. If the air is saturated with water and somebody sneezes virus droplets into such air, it is likely that the droplets will fall to the ground quicker, making them less infectious. So the short answer is yes, summer/sunshine could be bettera.

According to Dr Puneet Khanna, Head of Respiratory Medicine and Pulmonology, Manipal Hospital, Delhi, COVID-19 death rates are not too different in tropical countries but since the disease affected them late it was yet to show its peak in these areas.

"The virus can survive well in hot and humid countries and this is proven now," he stressed.

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