Why women develop heart disease later than men decoded

Agencies
October 6, 2017

Toronto, Oct 6: Women have a heart health advantage over men as the interplay between female ovarian hormones and a circadian "clock" molecule protects their cardiac health as they age, a study has found.

The findings, published in the journal Cardiovascular Research, could help prevent heart disease as we grow older.

In earlier studies, researchers from University of Guelph in Canada found that heart attacks were worse for males than for females of similar age.

The study also uncovered a time-of-day effect: heart attacks in males were more severe during sleep.

This led to the idea that the circadian mechanism - tiny clocks in all of our body's cells which regulate our 24-hour day and night processes - might work differently in male and female hearts.

To test that possibility, the researchers studied old mice with a genetic "clock" mutation that desynchronises the circadian mechanism.

"We think of these CLOCK mice as a genetic model of shift work," said Tami Martino, from University of Guelph.

"Surprisingly, ageing male CLOCK mice developed heart disease, but female CLOCK mice did not," said Martino.

Researchers discovered that female heart cells are actually different from those of males.

Cardiolipins in CLOCK male hearts look like those in humans with heart disease, Martino said.

The CLOCK males also had worse cardiac glucose and energy profiles. By contrast, CLOCK female hearts had a healthy cardiolipin profile and better energy, researchers said.

However, the advantage for CLOCK females was lost when the ovaries were removed, a clear sign that hormones such as oestrogen protect the heart even when the circadian mechanism is disturbed, Martino said.

The findings may lead to clinical benefits for women and men, researchers added.

"Maintaining good circadian rhythms is important for achieving healthier and longer lives," Martino said.

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Agencies
January 11,2020

Europe, Jan 11: Researchers have revealed the people who drink tea at least three times a week have healthy years of life and longer life expectancy.

The research was published in the European Journal of Preventive Cardiology, a journal of the European Society of Cardiology (ESC).

Dr Xinyan Wang, who is the author of the study, said: "Habitual tea consumption is associated with lower risks of cardiovascular disease and all-cause death. The favourable health effects are the most robust for green tea and for long-term habitual tea drinkers."
The analysis that was conducted included about 100,902 participants of the China-PAR project2 with no history of heart attack, stroke, or cancer.

Participants were classified into two groups: Habitual tea drinkers and never or non-habitual tea drinkers and followed-up for a median of 7.3 years.

The analyses estimated that 50-year-old habitual tea drinkers would develop coronary heart disease and stroke 1.41 years later and live 1.26 years longer than those who never or seldom drank tea. Compared with never or non-habitual tea drinkers, the habitual tea consumers had a 20 per cent lower risk of incident heart disease and stroke, 22 per cent lower risk of fatal heart disease and stroke, and 15 per cent decreased risk of all-cause death.

The potential influence of changes in tea drinking behaviour was suspected in a subset of 14,081 participants with assessments at two-time points. The average duration between the two surveys was 8.2 years, and the median follow-up after the second survey was 5.3 years.

Habitual tea drinkers who maintained their habit in both surveys had a 39 per cent lower risk of incident heart disease and stroke, 56 per cent lower risk of fatal heart disease and stroke, and 29 per cent decreased risk of all-cause death compared to consistent never or non-habitual tea drinkers.

Senior author Dr Dongfeng Gu said: "The protective effects of tea were most pronounced among the consistent habitual tea drinking group. Mechanism studies have suggested that the main bioactive compounds in tea, namely polyphenols, are not stored in the body long-term. Thus, frequent tea intake over an extended period may be necessary for the cardioprotective effect."

In a subanalysis by type of tea, drinking green tea was linked with approximately 25 per cent lower risks for incident heart disease and stroke, fatal heart disease and stroke, and all-cause death. However, no significant associations were observed for black tea.
Dr Gu noted that a preference for green tea is unique to East Asia.

Two factors may be at play. First, green tea is a rich source of polyphenols which protect against cardiovascular disease and its risk factors including high blood pressure and dyslipidaemia. Black tea is fully fermented and during this process, polyphenols are oxidised into pigments and may lose their antioxidant effects. Second, black tea is often served with milk, which previous research has shown may counteract the favourable health effects of tea on vascular function.

Gender-specific analyses showed that the protective effects of habitual tea consumption were pronounced and robust across different outcomes for men, but only modest for women. Dr Wang said: "One reason might be that 48 per cent of men were habitual tea consumers compared to just 20 per cent of women. Secondly, women had a much lower incidence of, and mortality from, heart disease and stroke. These differences made it more likely to find statistically significant results among men."

She said: "The China-PAR project is ongoing, and with more person-years of follow-up among women the associations may become more pronounced."

In conclusion, the authors have found that randomised trials are required to validate the results and to illustrate nutritional guidelines and advice for lifestyle.

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Agencies
May 14,2020

COVID-19 mostly kills through an overreaction of the immune system, whose function is precisely to fight infections, say scientists who have decoded the mechanisms, symptoms, and diagnosis of the disease caused by the SARS-Cov-2 coronavirus.

In a study published in the journal Frontiers in Public Health, the researchers explained step-by-step how the virus infects the airways, multiplies inside cells, and in severe cases causes the immune defences to overshoot with a "cytokine storm".

This storm is an over-activation of white blood cells, which release too-great amounts of cytokines -- inflammation-stimulating molecules --into the blood, they said.

"Similar to what happens after infection with SARS and MERS, data show that patients with severe COVID-19 may have a cytokine storm syndrome," said study author Daishun Liu, Professor at Zunyi Medical University in China.

"The rapidly increased cytokines attract an excess of immune cells such as lymphocytes and neutrophils, resulting in an infiltration of these cells into lung tissue and thus cause lung injury," Liu said.

The researchers explained that the cytokine storm ultimately causes high fever, excessive leakiness of blood vessels, and blood clotting inside the body.

It also causes extremely low blood pressure, lack of oxygen and excess acidity of the blood, and build-up of fluids in the lungs, they said.

The researchers noted that white blood cells are misdirected to attack and inflame even healthy tissue, leading to failure of the lungs, heart, liver, intestines, kidneys, and genitals.

This multiple organ dysfunction syndrome (MODS) may worsen and shutdown the lungs, a condition called acute respiratory distress syndrome, (ARDS), they said.

This, the researchers explained, happens due to the formation of a so-called hyaline membrane -- composed of debris of proteins and dead cells -- lining the lungs, which makes absorption of oxygen difficult.

Most deaths due to COVID-19 are therefore due to respiratory failure, they said.

The researchers explained that in the absence of a specific antiviral cure for COVID-19, the goal of treatment must be to the fight the symptoms, and lowering the mortality rate through intensive maintenance of organ function.

For example, an artificial liver blood purification system or renal replacement therapy can be used to filter the blood through mechanical means, they said.

The team noted that especially important are methods to supplement or replace lung function, for example with non-invasive mechanical ventilation through a mask, ventilation through a tube into the windpipe, the administration of heated and humidified oxygen via a tube in the nose, or a heart-lung bypass.

The researchers stressed the importance of preventing secondary infections.

They noted that SARS-Cov-2 also invades the intestines, where it causes inflammation and leakiness of the gut lining, allowing the opportunistic entry of other disease-causing microorganisms.

The researchers advocate that this should be prevented with nutritional support, for example with probiotics -- beneficial bacteria that protect against the establishment of harmful ones -- and nutrients and amino acids to improve the immune defences and function of the intestine.

"Because treatment for now relies on aggressive treatment of symptoms, preventative protection against secondary infections, such as bacteria and fungi, is particularly important to support organ function, especially in the heart, kidneys, and liver, to try and avoid further deterioration of their condition," Liu added.

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News Network
July 9,2020

Washington, Jul 9: Ayurvedic practitioners and researchers in India and the US are planning to initiate joint clinical trials for Ayurveda formulations against the novel coronavirus, the Indian envoy here has said.

In a virtual interaction with a group of eminent Indian-American scientists, academicians, and doctors on Wednesday, Indian Ambassador to the US Taranjit Singh Sandhu said the vast network of institutional engagements have brought scientific communities between the two countries together in the fight against Covid-19.

 “Our Institutions have also been collaborating to promote Ayurveda through joint research, teaching and training programs. Ayurvedic practitioners and researchers in both the countries are planning to initiate joint clinical trials of Ayurvedic formulations against Covid-19,” Sandhu said.

“Our scientists have been exchanging knowledge and research resources on this front,” he said.

The Indo-US Science Technology Forum (IUSSTF) has always been instrumental in promoting excellence in science, technology, and innovation through collaborative activities.

To address Covid-19-related challenges, the IUSSTF had given a call to support joint research and start-up engagements. A large number of proposals are being reviewed on fast track mode by the experts on both the sides, he said.

“Indian pharmaceutical companies are global leaders in producing affordable low-cost medicines and vaccines and will play an important role in the fight against this pandemic,” Sandhu said.

According to the ambassador, there are at least three ongoing collaborations between Indian vaccine companies with US-based institutions.

These collaborations would be beneficial not just to India and the US, but also for the billions who would need to be vaccinated against Covid-19 across the world, he noted.

Asserting that innovation will be the key driver in pandemic response and recovery, he said tech-companies and start-ups have already begun to take the lead in this direction.

"Telemedicine and telehealth will evolve as will other digital platforms across sectors," he said.

Noting that there has been a longstanding collaboration between India and the US in the health sector, he said scientists have been working together in several programs to understand important diseases at the basic and clinical level.

Many such programs have been focused on translational research to develop new therapeutics and diagnostics.

There are over 200 ongoing NIH funded projects in India involving 20 institutions from NIH network and several eminent institutions in India engaged in a wide spectrum of research areas to create health care solutions, the senior diplomat said.

The collaboration under Vaccine Action Program (VAP) resulted in the development of ROTAVAC vaccine against rotavirus which causes severe diarrhea in children.

The vaccine was developed by an Indian company (Bharat Biotech) at an affordable cost. It has been commercialised and introduced in the Expanded Program on Immunisation.

Development of many other vaccines such as TB, Influenza, Chikungunya are also in progress under the VAP, he said.

 “As I speak, the VAP meeting is in progress where experts from both countries are deeply engaged in technical discussions to expedite development of Covid-19 vaccine,” Sandhu said in his remarks.

During the interaction, the eminent experts appreciated India's handling of the Covid-19 pandemic and offered their valuable suggestions and best practices in this regard.

They shared their ideas on deepening the knowledge partnership between India and the US.

The experts who took part in the interaction, were drawn from wide-ranging fields including artificial intelligence, quantum information science, biomedical engineering, robotics, mechanical engineering, earth and ocean science, virology, physics, astrophysics, and health sciences.

Prominent among those who attended the virtual interaction were Subhash Kak Regents Professor at Oklahoma State University, Dr Vijay Kuchroo, Samuel L Wasserstrom Professor of Neurology at Harvard Medical School, Dr Ashish M Kamat, Professor of Urology at MD Anderson Cancer Center, Ashutosh Chilkoti, Alan L Kaganov Professor of Biomedical Engineering and Chair of the Department of Biomedical Engineering at Duke University; and Prof Manu Prakash, a professor in Department of Bioengineering at Sandford University, among others.

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