E-cigarettes can damage DNA, up cancer risk

Agencies
August 21, 2018

Washington, Aug 21: E-cigarettes -- often touted as a safer alternative to cigarette smoking -- may modify the DNA in the oral cells of users, potentially increasing the risk of cancer.

Introduced to the market in 2004, e-cigarettes are handheld electronic devices that heat a liquid, usually containing nicotine, into an aerosol that the user inhales.

Different flavours of liquids are available, including many that appeal to youth, such as fruit, chocolate and candy.

The popularity of e-cigarettes continues to grow worldwide, but the long-term effects of e-cigarette usage, commonly called "vaping," are unknown.

"We want to characterise the chemicals that vapers are exposed to, as well as any DNA damage they may cause," said Romel Dator, who presented the study in the US at the 256th National Meeting & Exposition of the American Chemical Society (ACS).

According to a 2016 report by the US Surgeon General, 13.5 per cent of middle school students, 37.7 per cent of high school students and 35.8 per cent of young adults (18 to 24 years of age) have used e-cigarettes, compared with 16.4 per cent of older adults (25 years and up).

"It's clear that more carcinogens arise from the combustion of tobacco in regular cigarettes than from the vapor of e-cigarettes," said Silvia Balbo, from the University of Minnesota in the US.

"However, we don't really know the impact of inhaling the combination of compounds produced by this device. Just because the threats are different doesn't mean that e-cigarettes are completely safe," said Balbo.

To characterise chemical exposures during vaping, researchers recruited five e-cigarette users.

They collected saliva samples before and after a 15-minute vaping session and analysed the samples for chemicals that are known to damage DNA.

To evaluate possible long-term effects of vaping, the team assessed DNA damage in the cells of the volunteers' mouths.

The researchers used mass-spectrometry-based methods they had developed previously for a different study in which they evaluated oral DNA damage caused by alcohol consumption.

Researchers identified three DNA-damaging compounds, formaldehyde, acrolein and methylglyoxal, whose levels increased in the saliva after vaping.

Compared with people who do not vape, four of the five e-cigarette users showed increased DNA damage related to acrolein exposure.

The type of damage, called a DNA adduct, occurs when toxic chemicals, such as acrolein, react with DNA. If the cell does not repair the damage so that normal DNA replication can take place, cancer could result.

The researchers plan to follow up this preliminary study with a larger one involving more e-cigarette users and controls.

They also want to see how the level of DNA adducts differs between e-cigarette users and regular cigarette smokers.

"Comparing e-cigarettes and tobacco cigarettes is really like comparing apples and oranges. The exposures are completely different," Balbo said.

"We still don't know exactly what these e-cigarette devices are doing and what kinds of effects they may have on health, but our findings suggest that a closer look is warranted," he said.

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Agencies
June 11,2020

The World Health Organisation (WHO) Director-General Tedros Adhanom Ghebreyesus said that more research needs to be done to better understand the extent to which COVID-19 is being spread by people who don't show symptoms.

"Since early February, we have said that asymptomatic people can transmit COVID-19, but that we need more research to establish the extent of asymptomatic transmission," the WHO chief said at a virtual press conference from Geneva on Wednesday, Xinhua news agency reported.

"That research is ongoing, and we're seeing more and more research being done," he added.

Saying that the world has been achieving a lot in knowing the new virus, the WHO chief told reporters that "there's still a lot we don't

"WHO's advice will continue to evolve as new information becomes available," he said.

Tedros stressed that the most critical way to stop transmission is to find, isolate and test people with symptoms, and trace and quarantine their contacts.

"Many countries have succeeded in suppressing transmission and controlling the virus doing exactly this," Tedros said.

Meanwhile, Michael Ryan, executive director of WHO Health Emergencies Program, said Wednesday that the COVID-19 pandemic is still evolving.

"If we look at the numbers... this pandemic is still evolving. It is growing in many parts of the world," he said. "We have deep concerns that health systems of some countries are struggling, under a huge strain and require our support, our help and our solidarity."

He said "each and every country has a different combination of risks and opportunities, and it's really down to national authorities to carefully consider where they are in the pandemic."

In Europe, the risk issue now are about travels and the opening of the schools, around risk management, mass gathering, surveillance and contact tracing, said the WHO official.

In Southeast Asian countries, where to a great extent transmissions have been under control, governments are more concerned about the re-emergence of clusters, while in South America, the issue of PPE for health workers has not gone away, said Ryan.

As regards Africa, Ryan said the death rates have been very low in the past week, but the health system can be overwhelmed, as it would have to cope with other diseases such as malaria.

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Agencies
March 11,2020

With the sales of chicken and mutton going down due to the coronavirus scare, it is the humble 'Kathal' (jackfruit) is emerging as an acceptable alternative.

'Kathal' is now selling at ₹120 per kilogram -- an increase of more than 120 per cent over the normal ₹50 per kilogram.

The jackfruit, in fact, is now priced higher than chicken which is selling at ₹80 per kilogram due to poor demand.

"It is better having a 'Kathal' biryani instead of a mutton biryani. It tastes reasonably good. The only problem is that 'Kathal' has been sold out in the vegetable market and is difficult to find," said Purnima Srivastava whose family savours non-vegetarian food on a regular basis.

The corona scare has hit poultry business so hard and the Poultry Farm Association recently organized a Chicken Mela in Gorakhpur to dispel the misconception that birds are carriers of the deadly virus.

"In fact, we gave away plateful of chicken dishes for Rs 30 to encourage people to savour the delicacies. We cooked one thousand kilograms of chicken for the Mela and the entire stock was sold out," said Vineet Singh, head of the Poultry Farm Association.

However, the Mela did not do much to dispel the fears about chicken, mutton or fish consumption amid the virus outbreak.

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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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