Extended space stay can alter brain structure


Long-term space missions can alter the astronaut’s brain structure, finds a study published in the New England Journal of Medicine.

The researchers compared before and after brain scans of 18 astronauts who had been in space for long durations and 16 astronauts who took shorter trips.

The scans revealed several structural changes in the brain of the astronauts, especially in those who participated in extended missions.

In 17 of the 18 astronauts who participated in long-duration flights and three of the astronauts on short-duration flights, there was a narrowing of the brain's central sulcus, a groove in the cortex near the top of the brain that separates the parietal and frontal lobes, parts of the brain that control movement of the body and higher executive function.

Another comparison of preflight and postflight MRI cine clips from high-resolution 3-D imaging of 12 astronauts from long-duration flights and six astronauts from short-duration flights also showed an upward shift of the brain and narrowing of the cerebrospinal fluid spaces at the top of the brain among the long-duration flight astronauts.

The longer an astronaut stayed in space, the symptoms appeared to worsen.

The researchers are planning to continue with their study to see if these structural changes are permanent or if they will return to normal after some time back on earth.

"Exposure to the space environment has permanent effects on humans that we simply do not understand. What astronauts experience in space must be mitigated to produce safer space travel for the public," said the lead researcher.

Glass of big c


Alcohol consumption—even light drinking—can increase the risk of several cancers, including those of the breast, colon, oesophagus, liver and head and neck, according to a statement released by the American Society of Clinical Oncology (ASCO).

Alcohol is directly responsible for 5-6 per cent of new cancers and cancer deaths globally. Yet, a vast majority of people do not consider alcohol as a risk factor, even though they recognise tobacco smoking as one.

All types of alcohol—beer, wine and hard liquor—increase the risk of developing cancer.

Women who are light drinkers have a 4 per cent increased risk of developing breast cancer. The risk is 23 per cent greater for moderate drinkers and 63 per cent greater for heavy drinkers.

Moderate drinkers (one daily drink for women and two for men) have about double the risk for cancers of the oesophagus and the oral cavity and pharynx. They also have an increased risk of cancers of the larynx and colon.

Heavy drinkers—eight or more drinks a week for women and 15 or more for men—have about five times the risk for cancers of the oesophagus and the oral cavity and pharynx and three times the risk for cancer of the larynx and double the risk for liver cancer.

"Even modest use of alcohol may increase cancer risk, but the greatest risks are observed with heavy, long-term use. Therefore, limiting alcohol intake is a means to prevent cancer. The good news is that, just like people wear sunscreen to limit their risk of skin cancer, limiting alcohol intake is one more thing people can do to reduce their overall risk of developing cancer," the lead author of the statement suggested.

Did You Know

Older women who undergo cataract surgery have a 60 per cent lower risk of death from all causes and a 37 to 69 per cent reduced risk of death from vascular, pulmonary, accidental, infectious, neurologic and cancer-related causes.
JAMA Ophthalmology

Air pollution causes bone fractures


Exposure to polluted air can increase the risk of bone fractures and loss of bone mineral density, according to a study published in The Lancet Planetary Health.

An analysis of 9.2 million older adults hospitalised for bone fractures suggests that even a slight increase in PM2.5 (a component of air pollution) concentrations would increase the risk of bone fractures in older adults.

Another analysis of 692 middle-aged, low-income adults has found that participants living in areas with higher levels of PM2.5 and black carbon had lower levels of an important calcium and bone-related hormone, and greater decreases in bone mineral density compared to those exposed to lower levels of these pollutants.

Osteoporosis is the most common reason for bone fractures among the elderly. The risk for death increases by up to 20 per cent in the year following a bone fracture, and only 40 per cent of those who had fractures regain their independence.

"Decades of careful research has documented the health risks of air pollution, from cardiovascular and respiratory diseases, to cancer, and impaired cognition, and now osteoporosis. Among the many benefits of clean air, our research suggests, are improved bone health and a way to prevent bone fractures," the study's senior author added.

Want to live longer? Get a Dog!


According to a Swedish study published in the journal Scientific Reports, dog owners have a lower risk of death from cardiovascular diseases or other causes, especially in the case of people who live alone.

The study included more than 3.4 million Swedes, aged 40 to 80, without any heart disease at the start of the study, and they were followed for 12 years.

While all dog owners had a reduced risk, dog owners who lived alone reaped the greatest benefit. They had a 33 per cent reduced risk of death and 11 per cent reduced risk of myocardial infarction compared to single non-dog owners.

Studies have shown that people who live alone have a higher risk of cardiovascular disease and death than those who live in a multi-person household. “Perhaps a dog may stand in as an important family member in the single households.”

The breed of the dog appeared to matter, too. Owning hunting type breeds like terriers, retrievers and scent hounds provided the highest benefits, while mixed breeds and toy breeds the least.

Dog owners generally tend to be physically active, which could explain the benefits seen in the study. “Other explanations include an increased well-being and social contacts or effects of the dog on the bacterial microbiome in the owner,” the senior author of the study said.

Can sex trigger cardiac arrest?

Here’s reassuring news for people who are worried that sexual activity can trigger cardiac arrests.

A study led by Dr Sumeet Chugh and published in the Journal of the American College of Cardiology finds that sexual activity rarely causes a sudden cardiac arrest.

Of the 4,557 cases studied, only 34 cases occurred during or within an hour of engaging in sex. Less than one per cent of the deaths from sudden cardiac arrest were related to sex. While rare, men were likely to suffer a cardiac arrest associated with sexual activity.

Did You Know

Children and young adults (ages 1-49) with diabetes are seven times more likely to die from sudden cardiac death and eight times more likely to die from any kind of heart disease compared to children and young adults without diabetes.
Danish study presented at the American Heart Association’s Scientific Sessions

Don’t gobble your food


If you are a fast eater, you may want to slow down!

According to a Japanese study presented at the American Heart Association's Scientific Sessions 2017, people who gobble their food are more likely to be obese and develop metabolic syndrome, a cluster of risk factors—including high blood pressure, high triglycerides, high blood sugar, low HDL cholesterol and a large waistline—linked to heart disease, diabetes and stroke.

The study was based on 642 men and 441 women, average age 51.2 years, who did not have metabolic syndrome at the onset. The participants were divided into three groups based on their usual eating speed: slow, normal and fast.

Fast eaters were almost twice as likely to develop metabolic syndrome over five years of follow up compared with normal eaters—11.6 per cent vs 6.5 per cent. The risk was 2.3 per cent for slow eaters. They were more likely to have gained weight and have higher blood glucose and larger waistline.

“Eating more slowly may be a crucial lifestyle change to help prevent metabolic syndrome. When people eat fast they tend not to feel full and are more likely to overeat. Eating fast causes bigger glucose fluctuation, which can lead to insulin resistance,” said the lead author.

Gene editing inside the body


In a medical first, US scientists have tried to edit a gene inside a patient’s body to cure a disease.

Brian Madeux, 44, has a rare genetic condition called Hunter syndrome, caused by a missing or malfunctioning enzyme that is essential to break down certain molecules. Without the enzyme, the molecules build up in the cells and can eventually cause permanent damage affecting appearance, mental development, organ function and physical abilities and lead to early death. There is no cure for Hunter syndrome, but it can be managed with enzyme replacement therapies.

Madeux already has had 26 surgeries to manage his symptoms.

The patient received billions of copies of a corrective gene to replace the mutated gene through an IV, along with a gene editing tool called Zinc Finger that cuts the abnormal DNA in a precise spot. The infusion takes only 2-3 hours.

The doctors will know whether the treatment worked in three months.

The treatment was designed by Sangamo Therapeutics.

High blood pressure redefined


The American Heart Association and the American College of Cardiology has issued new guidelines that would lower the diagnostic threshold for high blood pressure to 130/80, down from the current level of 140/90.

High blood pressure is called a “silent killer” and it can lead to heart attacks, strokes and heart failure.

The new guidelines eliminate the category of prehypertension, which was used for blood pressure readings between 120-139 mm Hg or between 80-89 mm Hg.

The blood pressure categories in the new guidelines are Normal: Less than 120/80 mm Hg; Elevated: between 120-129 and less than 80; Stage 1: 130-139 or 80-89; Stage 2: 140/ 90 mm Hg or higher and Hypertensive Crisis: higher than 180 and/or higher than 120.

As per the new guidelines, nearly half (46 per cent) of the US adult population will have high blood pressure. It is expected to triple the prevalence among men under age 45, and double among women under 45.

People who have a reading within the 130-139 range have double the risk of heart attack, stroke, heart failure and kidney failure, compared to those with normal readings. Identifying these patients and initiating interventions can help bring down blood pressure and its related risks.

According to the researchers, the new guidelines do not mean a proportionate increase in the use of medication. Medication will be prescribed for Stage I hypertension only if the patient already had a cardiovascular event, such as heart attack or stroke, or has other medical conditions that increase their risk for a cardiac event.

The study authors recommend lifestyle changes, including regular exercise, healthy diet with low salt intake, increasing potassium-rich food, losing weight, and limiting alcohol consumption as the first step for combating high blood pressure.

The new guidelines also stress the importance of using proper technique to measure blood pressure. A person's blood pressure level should be based on an average of two to three readings on at least two different occasions.

Alzheimer’s outside the brain?

Alzheimer’s disease is a brain disorder that is believed to originate in the brain. But new research published in Molecular Psychiatry questions the assumption.

The buildup of a protein called beta-amyloid is one of the hallmarks of Alzheimer's disease. A study in mice has shown that it could travel to the brain from other parts of the body.

Using a method called “parabiosis", that involves “surgically attaching two specimens together so they share the same blood supply for several months,” the researchers attached normal mice to mice that were genetically modified to carry a mutant human gene that produces high levels of the protein amyloid-beta.

In 12 months, normal mice that had been joined to genetically modified partners developed Alzheimer's disease. “Amyloid-beta protein travelled from the genetically-modified mice to the brains of their normal partners, where it accumulated and began to inflict damage.”

Their brains also had "tangles" or twisted protein strands that disrupt brain cells and eventually kill them.

Other signs of Alzheimer's including brain cell degeneration, inflammation and microbleeds were also evident.

Additionally, the ability to transmit electrical signals involved in learning and memory was also impaired even in mice that had been joined for only four months.

Apart from the brain, amyloid-beta protein is also produced in blood platelets, blood vessels and muscles.

“The blood-brain barrier weakens as we age. That might allow more amyloid beta to infiltrate the brain, supplementing what is produced by the brain itself and accelerating the deterioration."

If the findings hold true in humans, it could lead the way to drugs that could eliminate amyloid-beta protein from the body before it ever reaches the brain.

"Alzheimer's disease is clearly a disease of the brain, but we need to pay attention to the whole body to understand where it comes from, and how to stop it."

Digital pill


The US FDA has approved the first digital pill with an embedded sensor that can track if the patient has taken the medication.

Abilify MyCite is a version of the pill aripiprazole which has been approved for patients with schizophrenia, manic and mixed episodes associated with bipolar I disorder and as an add-on treatment for depression.

The pill contains a sensor that can send a message to a wearable patch, which then transmits the information to an app on the patient’s smartphone, allowing the patient to keep track of the ingestion of the medication.

Patients can also allow their doctors or family members to access the information through a web-based portal.

About the size of a grain, the sensor is made up of ingredients found in food and is activated when it comes in contact with stomach fluid. The sensor is later eliminated from the body.

The system may help enhance compliance in patients with severe mental illness.

“Being able to track ingestion of medications prescribed for mental illness may be useful for some patients. The FDA supports the development and use of new technology in prescription drugs and is committed to working with companies to understand how technology might benefit patients and prescribers,” the director of the Division of Psychiatry Products in the FDA noted.

Abilify MyCite is not approved for patients with dementia-related psychosis.

IUDs linked to lower cervical cancer risk

Women who use intrauterine devices (IUDs) for contraception may also have an added benefit—a lower risk of cervical cancer.

For the study published in Obstetrics & Gynaecology, US researchers examined data from 16 previously published studies involving 4,945 women who had cervical cancer and 7,537 women who did not.

Women who used IUDs were 36 per cent less likely to get cervical cancer compared to women who did not use them.

“The possibility that a woman could experience some help with cancer control at the same time she is making contraception decisions could potentially be very, very impactful,” the lead researcher noted.

Cervical cancer is the third most common cancer in women worldwide. The number of women diagnosed with cervical cancer is increasing steadily, especially in developing countries, where women have limited access to cervical cancer prevention measures such as the HPV vaccine or regular cervical screenings.

“A staggering number of women in the developing world are on the verge of entering the age range where the risk for cervical cancer is the highest—the 30s to the 60s. Even if the rate of cervical cancer remains steady, the actual number of women with cervical cancer is poised to explode. IUDs could be a tool to combat this impending epidemic.”

The researchers speculate that IUDs may trigger an immune response in the cervix, helping the body fight HPV infections that could lead to cervical cancer.


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The Week

Topics : #health

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