There is not one kind of ‘good sperm’ — it depends on other qualities in the male

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In a study published in Behavioral Ecology researchers from Uppsala University show that the same type of sperm is not always the best for all male birds. Depending on how attractive or dominant you are you might be more successful with longer or shorter sperm.

Getting a big family can be a difficult business in nature. If you are a male bird, you have to work hard to secure a territory where you will find food for your chicks and convince a lady that you are both good looking enough and also will be a good dad. But getting a mating partner is not the end of the story, you also need to fertilize her eggs, preferably all of them!

For this, you will need good sperm: sperm that is good at fertilizing eggs, but not only, it also has to be BETTER than the sperm of your potential rivals, that is other males your partner might be copulating with before laying all of her eggs. This happens often in nature, because females do not want to put all of their eggs in the same basket and it might be advantageous instead to have some genetic variation among your offspring.

Determining what makes for a good or attractive male is not always easy, and measuring what makes a good sperm is even harder. Now these two important components of fertilization success are often also measured separately, and we do not really understand how they are linked.

The researchers studied this in collared flycatchers (small black and white birds), by catching close to 120 different males over 4 years, measuring their white forehead patch (used to attract females), their sperm morphology (under the microscope), and their paternity success (i.e. how many of the chicks in their nests were theirs, by analyzing the blood of over 400 six-days old nestlings).

The team found that different categories of males have different sperm morphology, depending on if they manage to secure a territory and have a social mating partner, but also on their age and attractiveness. But most interestingly, the researchers found that the type of sperm that allows them to maximize the number of nestlings they father is different for different types of males. For males that have small forehead patches and are thus less dominant and less attractive, having long sperm is beneficial. This could be because they are more exposed to sperm competition and long sperm are likely to swim faster and reach the egg first.

But longer is not always better! For more attractive males, it is quite the opposite, and having smaller sperm allows them to sire more eggs in their nest.

“Many studies have attempted to link attractiveness and sperm quality, trying to figure out if “sexier” males also have better sperm, with very inconsistent results between studies. Our study shows that what makes a good quality sperm might instead depend on how attractive, competitive, and how old a male is, so there is not one single kind of “good sperm”, and we should more often look at the full picture and actually measure which phenotypes result in the highest fertilization success”, says lead author Murielle Ålund, now researcher at Michigan State University.

 

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Testosterone Therapy: “Significant Reduction” in Heart Attack, Stroke Risks

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Large-scale Veterans Affairs database study reaffirms safety and benefits of testosterone replacement, in men.

A US Veterans Affairs database study of more than 83,000 male subjects found that men whose low testosterone was restored to normal through gels, patches, or injections had a lower risk of heart attack, stroke, or death from any cause, versus similar men who were not treated.  Rajat Barua and colleagues analyzed data collected on 83,010 male veterans with documented low total testosterone levels, dividing them into three clinical groups: those who were treated to the point where their total testosterone levels returned to normal (Group 1); those who were treated but without reaching normal (Group 2); and those who were untreated and remained at low levels (Group 3).  Importantly, all three groups were “propensity matched” so the comparisons would be between men with similar health profiles. The researchers took into account a wide array of factors that might affect cardiovascular and overall risk. The average follow-up across the groups ranged from 4.6 to 6.2 years. The sharpest contrast emerged between Group 1 (those who were treated and attained normal levels) and Group 3 (those whose low testosterone went untreated). The treated men were 56% less likely to die during the follow-up period, 24%less likely to suffer a heart attack, and 36%less likely to have a stroke.  The differences between Group 1 and Group 2 (those who were treated but did not attain normal levels) were similar but less pronounced.  The study authors conclude that: “normalization of [total testosterone] levels after [testosterone replacement therapy] was associated with a significant reduction in all-cause mortality, [myocardial infarction], and stroke.”

Sharma R, Oni OA, Gupta K, Chen G, Sharma M, Dawn B, Sharma R, Parashara D, Savin VJ, Ambrose JA, Barua RS. “Normalization of testosterone level is associated with reduced incidence of myocardial infarction and mortality in men.”  Eur Heart J. 2015 Aug 6. pii: ehv346.

Article Source: https://www.worldhealth.net/news/testosterone-therapy-significant-reduction-heart-a/

 

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New ways to conquer sleep apnea compete for place in bedroom

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Every night without fail, Paul Blumstein straps on a mask that prevents him from repeatedly waking up, gasping for air.

It’s been his routine since he was diagnosed with a condition called sleep apnea. While it helps, he doesn’t like wearing the mask.

“It’s like an octopus has clung to my face,” said Blumstein, 70, of Annandale, Virginia. “I just want to sleep once in a while without that feeling.”

It’s been two decades since doctors fully recognized that breathing that stops and starts during sleep is tied to a host of health issues, even early death, but there still isn’t a treatment that most people find easy to use.

Airway pressure masks, the most common remedy, have improved in design, getting smaller and quieter, but patients still complain about sore nostrils, dry mouths and claustrophobia.

Now, new ways of conquering sleep apnea, and the explosive snoring that comes with it, are vying for a place in the bedrooms of millions of people craving a good night’s sleep. Products range from a $350 restraint meant to discourage back sleeping to a $24,000 surgical implant that pushes the tongue forward with each breath.

Mouthpieces, fitted by dentists, work for some people but have their own problems, including jaw pain. Some patients try surgery, but it often doesn’t work. Doctors recommend weight loss, but diet and exercise can be challenging for people who aren’t sleeping well.

So far, no pills for sleep apnea exist, but researchers are working on it. One drug containing THC, the active ingredient in marijuana, showed promise in a study this year.

What is sleep apnea? In people with the condition, throat and tongue muscles relax and block the airway during sleep, caused by obesity, aging or facial structure. They stop breathing, sometimes for up to a minute and hundreds of times each night, then awake with loud gasping and snoring. That prevents them from getting deep, restorative sleep.

They are more likely than others to have strokes, heart attacks and heart rhythm problems, and they’re more likely to die prematurely. But it’s hard to tease out whether those problems are caused by sleep apnea itself, or by excess weight, lack of exercise or something else entirely.

For specialists, the first-choice, most-studied remedy remains continuous positive airway pressure, or CPAP. It’s a motorized device that pumps air through a mask to open a sleeper’s airway. About 5 million Americans have tried CPAP, but up to a third gave up during the first several years because of discomfort and inconvenience.

Martin Braun, 76, of New York City stopped using his noisy machine and awkward mask, but now he’s trying again after a car crash when he fell asleep at the wheel. “That’s when I realized, OK this is serious stuff already,” said Braun, who has ordered a quieter CPAP model.

Sleep medicine is a relatively new field. The most rigorous studies are small or don’t follow patients for longer than six months, said Dr. Alex Krist of Virginia Commonwealth University, who served on a federal guidelines panel that reviewed sleep apnea treatments before recommending against screening adults who have no symptoms.

“We don’t know as much about the benefits of treating sleep apnea as we should,” said Krist, vice-chair of the U.S. Preventive Services Task Force.

While scientists haven’t proved CPAP helps people live longer, evidence shows it can reduce blood pressure, improve daytime sleepiness, lessen snoring and reduce the number of times a patient stops breathing. CPAP also improves quality of life, mood and productivity.

With noticeable results, many CPAP users, even those like Blumstein with a love-hate relationship with their devices, persist.

Blumstein was diagnosed about 15 years ago after he fell asleep behind the wheel at a traffic light. He shared his frustrations with using a mask at a recent patient-organized meeting with the Food and Drug Administration, as did Joelle Dobrow of Los Angeles, who said it took her seven years to find one she liked.

“I went through 26 different mask styles,” she said. “I kept a spreadsheet so I wouldn’t duplicate it.”

Researchers are now focused on how to get people to use a mask more faithfully and predicting who is likely to abandon it and could start instead with a dental device.

“It’s the bane of my existence as a sleep doctor,” said Dr. James Rowley of Wayne State University in Detroit. “A lot of what sleep doctors do in the first few months after diagnosis is help people be able to use their CPAP.”

Getting it right quickly is important because of insurers’ use-it-or-lose-it policies.

Medicare and other insurers stop paying for a rented CPAP machine if a new patient isn’t using it enough. But patients often have trouble with settings and masks, with little help from equipment suppliers, according to Dr. Susan Redline of Brigham and Women’s Hospital in Boston.

All told, it can drive people toward surgery.

Victoria McCullough, 69, of Escondido, California, was one of the first to receive a pacemaker-like device that stimulates a nerve to push the tongue forward during sleep. Now, more than 3,000 people worldwide have received the Inspire implant. Infections and punctured lungs have been reported; the company says serious complications are rare.

McCullough said she asked her doctor to remove the device soon after it was activated in 2015.

“It was Frankenstein-ish. I didn’t like it at all,” McCullough said. “My tongue was just thrashing over my teeth.”

Others like the implant. “My quality of life is 100 percent better,” said Kyleene Perry, 74, of Edmonds, Washington, who got one in February after struggling with CPAP for two years. “People are saying, ‘You look so much better.’ I have a lot more energy.”

The THC pill, known as dronabinol, already is used to ease chemotherapy side effects. A small experiment in 73 people suggests it helps some but wasn’t completely effective. It may work better in combination with CPAP or other devices, said researcher David Carley of the University of Illinois at Chicago. He owns stock in Respire Rx Pharmaceuticals, which has a licensing agreement with the university for a sleep apnea pill.

As the search for better treatments continues, listening to patients will be key, said Redline.

“We are actually just treating a very tiny percentage of people effectively,” she said.

Article Source: https://medicalxpress.com/news/2018-07-ways-conquer-apnea-bedroom.html

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