Surprising bat genetic trait holds secrets of longevity

Updated 08 February 2018
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Surprising bat genetic trait holds secrets of longevity

WASHINGTON: Bats are the longest-lived mammals relative to body size, and a species called the greater mouse-eared bat lives especially long. Researchers now have unlocked some of this bat’s longevity secrets, with hints for fighting the effects of aging in people.
Scientists said on Wednesday that unlike in people and most other animals, in this bat species the structures called telomeres located at the end of chromosomes, thread-like strands inside a cell’s nucleus that carry genes determining heredity, do not shorten with age.
Only 19 mammal species are longer-lived than humans relative to body size. Eighteen of them are bats, some living more than four decades. The other is a weird African rodent called a naked mole rat.
The researchers identified two genes in the greater mouse-eared bat that may be responsible for its unique longevity adaptation. These mechanisms could be the focus of future studies on aging, with an eye toward extending healthy lifespans in people, the researchers said.
Telomeres are protective caps at the ends of chromosomes that shorten each time a cell divides. This drives the natural aging process, leading to a breakdown of cells that over time can drive tissue deterioration and eventually death.
“Studying exceptionally long-living mammals that have naturally evolved mechanisms to fight aging is an alternative way to identify the molecular basis of extended ‘health spans,’” said biologist Emma Teeling of University College Dublin in Ireland, one of the study leaders. “Bats are an exciting new model species that will enable us to identify new molecular mechanisms that drive healthy aging.”
The researchers studied 493 individual bats from four species: the greater mouse-eared bat and Bechstein’s bat, both members of the bat genus called Myotis; the greater horseshoe bat; and the common bent-wing bat. Of these, the greater mouse-eared bat had the longest lifespan, about 37 years.
The greater mouse-eared bat and the closely related Bechstein’s bat had telomeres that did not shorten with age, suggesting that Myotis bats share this characteristic. Another Myotis bat, Brandt’s bat, holds the bat longevity record of 41 years.
Based on body size, the greater mouse-eared bat would be predicted to have a maximum lifespan of four years. Its range spans from Western Europe into the Middle East. It preys on large, ground-dwelling creatures like beetles, crickets and spiders.
The research was published in the journal Science Advances.


Blood donation in the Middle East: The gift of life that is easy to give

Updated 14 June 2019
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Blood donation in the Middle East: The gift of life that is easy to give

  • World Blood Donor Day observed on June 14 to raise awareness of the life-saving importance of blood donation
  • Regular, voluntary donors are vital worldwide for adequate supply of safe blood and blood products

DUBAI: Blood donations in the Middle East have been described as “the gift of life” as the region struggles to cope with the demands posed by conflicts, humanitarian emergencies and the medical needs of a growing population.

International health experts have called on regular donors to step forward to mark World Blood Donor Day on June 14.

This year’s campaign focuses on blood donation and universal access to safe blood transfusion, and according to the World Health Organization (WHO), more donors are needed “to step forward to give the gift of life.”

Those who benefit most from blood donations include people suffering from thalassaemia, a blood disorder that affects hemoglobin and the red blood cell count, as well as victims of road accidents, cancer patients and sickle-cell disease patients.

Experts say while the Gulf Cooperation Council (GCC) countries have launched numerous initiatives to raise awareness of the lifesaving importance of blood donation, there is an increasing need across a wider region for regular donors.

“Many countries in the region face challenges in making sufficient blood available while also ensuring its quality and safety, especially during humanitarian emergencies and conflicts,” Dr. Ahmed Al-Mandhari, WHO regional director for the Eastern Mediterranean, told Arab News.

The GCC countries say they collect in total more than 10 whole blood donations per 1,000 population per year, or about 1 percent, Al-Mandhari said.

According to WHO, blood donations by 1 to 3 percent of the population are sufficient to meet a country’s needs. Even so, achieving self-sufficiency is a daunting challenge for many countries.

Al-Mandhari said that more than 90 percent of the blood is collected from voluntary, unpaid donors, aged from 18 to 44, with an increasing proportion of repeat donors. What is more, blood demand is unpredictable and even differs with each blood type. “For example O- blood can be given to patients with all blood types. But AB+ can only be given to patients with AB+,” he said.

Then there is the issue of short shelf life.

“To be ready to help patients in all hospitals, countries aim to stock usually six days’ worth of each blood type at all times,” Al-Mandhari said. “Since blood has a short shelf life — a 42-day window — and cannot be stockpiled, blood banks are forced to depend on donors to help maintain stocks.”

WHO’s most recent report on blood safety and availability points to “gaps in the key elements of national blood systems” in the Middle East.

A Saudi donor flashes the v-sign for victory as he gives blood in Jeddah. The Kingdom has one of the highest rates of repeat donors in the region. (AFP )

While GCC countries have taken steps to keep stocks at optimum levels, other countries in the Middle East are lagging behind international standards. The WHO report shows wide variations in annual blood-donation rates among countries, ranging from 0.7 per 1,000 population in Yemen to 29 per 1,000 population in Lebanon.

Al-Mandhari laid out the solution in a few easy steps: “Governments need to provide adequate resources, and put in place systems and infrastructure to increase the collection of blood from voluntary, regular unpaid blood donors, provide quality donor care, promote and implement appropriate clinical use of blood; and set up systems for oversight and surveillance across the blood-transfusion supply chain.”

On the positive side, Saudi Arabia recorded a rate of 13.8 per 1,000 population, with a healthy spread across all age groups. The country also has one of the highest rates of repeat donors (91 percent) in the region. According to the WHO report, the proportion of repeat, voluntary, non-remunerated blood donation in the Kingdom is 65.3 percent, which “will keep the prevalence of transfusion-transmissible infections among blood donors at much lower levels than in the general population.”

In recent years, Saudi health officials have introduced a number of measures to ensure adequate stocks in blood banks, including those run by the Ministry of Health and dedicated centers. These include a large facility at King Fahad Medical City (KFMC) and the country’s Central Blood Bank.

In the Kingdom, to be eligible for blood donation, donors must be aged over 17, weigh more than 50 kg, and have passed a brief medical examination. The health ministry recently launched Wateen, an app designed to ease blood-donation procedures and help ensure facilities across the Kingdom have adequate quantities of blood by 2020.

KFMC officials say that every day at least 2,000 units of blood components are needed to sustain a minimum supply for patients at the facility and other governmental and non-governmental hospitals in Riyadh. Donated blood components are essential for the management of cases involving cancer, sickle-cell disease, organ transplant, surgery, childbirth and trauma, to name just a few.

The situation is not very different in the other GCC countries, which also need more donors.

In the UAE, Dubai Blood Donation Center, which accounts for roughly half of the total blood collected in the emirates, frequently highlights the urgent need for donors. In 2018 alone, it ran 635 blood-donation campaigns, which resulted in 63,735 donors and a collection of 50,456 blood units.

While all blood types are needed, negative blood types are in greater demand due to their rarity. “There is a continuous demand for all blood types as blood lasts for only 42 days. So donors are always needed to come forward to replenish these stocks,” Dr. Mai Raouf, director of Dubai Blood Donation Center, said.

“People can donate blood every eight weeks, with each donation potentially saving up to three lives,” she told Arab News. 

Given that transfusion of blood and blood products save millions of lives every year, and the fact that “regular donors are the safest group of donors,” the importance of encouraging people to return to donate blood, rather than be one-time donors, can hardly be overemphasized, experts say.

“Without a system based on voluntary, unpaid blood donation, particularly regular voluntary donation, no country can provide sufficient blood for all patients who require transfusion,” Al-Mandhari said.

“WHO is calling on all countries in the region to celebrate and thank individuals who donate blood — and to encourage those who have not yet donated blood to start donating,” he said.