Monthly Archives: June 2017

Western Men See Drop in Sperm Counts, But The Cause Is Still Unknown

Sperm counts among men in Western countries have dropped considerably in the last several decades, according to a new study.

Researchers analyzed information from 185 previous studies involving a total of more than 42,000 men in 50 countries. These men had all given semen samples for research, but typically not for reasons related to fertility problems. For example, some were college students, or were men who were undergoing health screenings before entering military service.

The results showed that, from 1973 to 2011, there was a decline of more than 50 percent in sperm counts among men living in North America, Europe, Australia and New Zealand.

The researchers said that they cannot determine from their data what might have caused the decline, but it could be related to environmental or lifestyle factors. The findings are concerning, not only because men’s sperm counts are linked with their chances of conceiving a child, but also because poor sperm counts have been linked with a number of other poor health outcomes, including an increased risk of early death. [Trying to Conceive: 12 Tips for Men]

“Given the importance of sperm counts for male fertility and human health, this study is an urgent wake-up call for researchers and health authorities around the world to investigate the causes of the sharp ongoing drop in sperm count, with the goal of prevention,” Dr. Hagai Levine, lead author of the study and head of the Environmental Health Track at the Hebrew University-Hadassah Braun School of Public Health and Community Medicine in Israel, said in a statement.

Although previous research had suggested there has been a decline in men’s sperm count in recent years, the question of whether sperm counts are really dropping remained controversial. The new study is broader and more rigorous in design than previous research, and took into account factors that might explain drops in sperm count, such as age and the method of semen collection, the researchers said.

The researchers did not find a similar decline in sperm counts among men living in South America, Asia and Africa. But they noted that there have been fewer studies on sperm counts on men living in these areas, so it’s possible that there has been a decline that has gone undetected, the researchers said.

Some factors that have been linked with lower sperm counts include chemical exposures in the womb, exposures to pesticides, smoking, stress and obesity.

“Thus, a decline in sperm count might be considered as a ‘canary in the coal mine’ for male health across the lifespan,” the researchers wrote in their paper, published July 25 in the journal Human Reproduction Update. “Our report of a continuing and robust decline should, therefore, trigger research into its causes,” they said.

Fat Glue Inspired By Patch Beating Hearts

A new glue inspired by slug slime can mend a broken heart.

The adhesive, described today (July 27) in a new study in the journalScience, sticks to wet surfaces, including the surface of a beating heart. It isn’t toxic to cells, which gives it an advantage over many surgical glues. It’s not available in operating rooms just yet — its developers say that could take years — but it could potentially be approved much more quickly for applications such as closing skin wounds.

The slug-inspired glue is “very stretchy and very tough,” said Jianyu Li, a postdoctoral researcher at Harvard University’s Wyss Institute for Biologically Inspired Engineering and the lead author of the study. Li and his colleagues applied the adhesive to a blood-soaked, beating pig heart and found that it worked better than any other surgical glue on the market.

The inspiration for the glue came from Arion subfuscus, a large and slimy species of slug found in North America and western Europe. These slugs excrete a sticky, yellow-orange slime that adheres well to wet surfaces. [7 Cool Technologies Inspired by Nature]

That characteristic intrigued Li and his colleagues, and they set to work making an artificial version of the slime. The key, Li told Live Science, is that the slime is made up of long, straight chains of molecules called polymers, which are also bound to each other — a phenomenon called cross-linking. Cross-linking makes materials strong, but the slug slime has the added advantage of having two types of cross-link bonds. Some were covalent bonds, which means they hold molecules together by sharing electrons. Others were ionic bonds, meaning one molecule hands over its electrons to another. These “hybridized” cross-links make the slug mucus both tough and stretchy, Li said.

The team mimicked this structure using artificial polymers layered onto what they called a “dissipative matrix.” The polymers provide the sticking power, Li explained, while the dissipative-matrix layer acts like a shock absorber: It can stretch and deform without rupturing.

To test the glue, the researchers applied it to pig skin, cartilage, arteries, liver tissue and hearts — including hearts that were inflated with water or air and covered in blood. The material proved extremely stretchable, expanding 14 times its original length without ever breaking loose from the liver tissue. When used to patch a hole in a pig heart, the adhesive maintained its seal even when it was stretched to twice its original length tens of thousands of times, at pressures exceeding normal human blood pressure.

The researchers even applied the adhesive to the beating heart of a real pig and found that the adhesion to the dancing, bloody surface was about eight times as strong as the adhesion of any commercially available surgical glue.

The glue was also tested in a living rat: The researchers simulated an emergency surgery by slicing the rats’ liver tissue and then patching the wound with either the glue or a standard blood-staunching product called Surgiflo. They found that the new adhesive was as good atstopping the blood flow as the standard glue; the rats treated with the new glue experienced no additional hemorrhaging up to two weeks after the surgery. The Surgiflo-treated rats, however, sometimes suffered from tissue death and scar tissue, the researchers reported. The rats treated with the slime-inspired glue did not experience these side effects.

Whether the new glue makes it to the operating room depends on much more extensive clinical testing, Li said, but the adhesive could make its debut as a new method of dressing external wounds on a shorter timeline than that.

“We have a company working on trying to push our material to clinical applications, and we have a patent pending,” Li said.

Anorexia Following Causes, Symptoms & Treatment

Anorexia nervosa involves an extreme obsession with limiting food intake and weight that can end up taking over a person’s life. It is defined as a perceived intense need to drastically limit food intake to produce weight loss.

Anorexia is often thought to affect mostly women. “There is evidence that this is the case, but also conflicting information that boys are equally anorexic but it goes unnoticed and underreported,” said Jeanette Raymond, a licensed psychologist. Anorexia affects 0.9 percent of American women, according to the National Association of Anorexia Nervosa and Associated Disorders (ANAD). From 5 to 10 percent of people diagnosed with anorexia are male, according to the University of Pittsburgh.

Anorexia is not really about food, according to the Mayo Clinic. People with anorexia are looking for a way to cope with emotional problems, so they try to find something in their life they can control. Food is something that is a constant in a person’s life, so it can be controlled.

As with many mental-health conditions, the exact causes of anorexia are difficult to pinpoint. Scientific research has helped to narrow down the field of likely causes, such as metabolism, psychological issues and genetics.

“There are clear genetic risk factors for eating disorders,” said Dr. James Greenblatt, chief medical officer at Walden Behavioral Care in Waltham, Massachusetts. “As the increase of genetic vulnerability becomes more evident, genetic researchers around the world are looking to identify specific genetic markers.”

“Family studies have consistently demonstrated that anorexia nervosa runs in families,” Cynthia Bulik wrote in her study, “The Genetics of Anorexia Nervosa,” published in 2007 in the journal Annual Review of Nutrition.

If anorexia is caused (or at least heavily influenced) by genetics, people with the disease could be treated using information discovered in their genes, according to Price Foundation Candidate Gene Project.

Clinicians have found patterns in psychological issues with patients who have eating disorders, according to the ANAD. These signs include perfectionism, a need to be liked, a need for attention, a lack of self-esteem and high family expectations.

Factors involving the family that may trigger anorexia, according to Raymond, include the following:

  • overpowering mothers
  • mothers who need their daughters to take care of their emotional needs
  • separation anxiety
  • lack of parental attunement during a phase of development when appearance is important to the child
  • lack of connection with the father at that same crucial stage of development

Dr. Walter Kaye of the University of California, San Diego, an eating-disorder researcher, thinks too much blame has been placed on thin fashion models and other media images.

“People have long been blaming families and the media, but eating disorders are biological illnesses, and better treatments will come from more biologically based approaches,” Kaye told Scientific American Mind magazine in June 2008.

There are two types of anorexia: the restricting type and the binge-eating/purging type, according to the University of Pittsburgh. The most obvious sign of anorexia is not eating, or restricting the amount of food one eats. People with anorexia may avoid meals or may refuse to eat around other people. They may lie about how much they have eaten, withdraw from family or friends and stay home instead of going to social events. They often become moody, depressed, obsessive about their weight and disinterested in the things they once enjoyed.

There can be other, sneakier ways a person with anorexia can control calorie intake. For example, some will exercise excessively to burn calories, according to the National Institutes of Health. They may cut portions into tiny pieces and move them around on their plate, contemplating every bite. They may go to the bathroom immediately following meals.

Binge eating and purging are behaviors usually associated with bulimia — another eating disorder — but they can also be symptoms of anorexia. Some people with anorexia may eat massive amounts of food in a short amount of time. Afterward, to get rid of the food, the person may purge by using laxatives, diuretics or enemas, or by vomiting, according to the National Association for Anorexia and Associated Disorders (ANAD).

Because food is fuel for the body, restricting food intake can cause drastic changes. Major weight loss is the most noticeable change, but inside, the body deteriorates quite quickly. According to the Mayo Clinic, malnutrition leads to:

  • heart problems
  • constipation
  • low blood pressure
  • osteoporosis
  • swelling in the arms and legs
  • abnormal blood counts
  • loss of menstruation
  • dehydration
  • insomnia

While someone with anorexia may say they are trying to look better, the disease will often cause a person’s looks to deteriorate. Hair will turn brittle or may even fall out, fingers turn blue, skin becomes dry and a soft layer of hair will grow all over the skin. Fatigue from anorexia can also leave the person pale, with large circles under the eyes.

Not everyone who dies of anorexia dies from starvation. One in five anorexia deaths is by suicide, according to ANAD.

While anorexia and bulimia are both eating disorders, and some symptoms overlap, they are not interchangeable. Anorexia mostly involves not eating, or limiting food intake for long periods of time, resulting in weight loss beyond what is considered healthy (15 percent or more below the normal weight for the person’s age and height, according to NIH). On the other hand, people with bulimia tend to maintain a normal body weight but control their food intake in a cycle of binging and purging.

A person can suffer from both disorders at the same time or separately throughout their lives. About 40 percent of bulimia patients often have first had a diagnosis of anorexia, according to the University of Pittsburgh.

Only one in 10 men and women with eating disorders receive treatment, according to ANAD, and eating disorders kill more people than any other mental illness.

Because anorexia can cause so many problems in the body, the first step in recovery is to treat the symptoms. For example, first steps can include getting the person hydrated and on medication that can help with heart arrhythmias caused by the lack of nourishment.

Once the symptoms have been addressed, action will be taken to help the person gain weight while addressing the psychological issues underlying the disease. Therapy, antidepressants or other psychiatric medications and hospitalization are all possible treatments for anorexia.

“The duration and severity of anorexia determines the treatment options,” Raymond said. The least-severe cases respond to cognitive behavioral therapy, a type of “talk therapy” that enables patients to develop healthy boundaries and a sense of control outside of refusing food. Group therapy and family therapy are also helpful. Because mother-daughter issues are often a trigger for anorexia, therapy often entails treatment to make it safe for the girl to separate and make relationships outside the family, she said.

Raymond also noted that antidepressants might have only short-term success if underlying psychiatric issues are not addressed. Often, the anorexia will persist and become more severe, Raymond said.

Additional treatments for anorexia do not seem to be on the horizon, experts say. “Although there are more research studies on eating disorders, there are currently no new clinical treatments available. The new research demonstrates abnormalities in brain structure and neurochemical functions among individuals with eating disorders. However, the research has not been translated into any new clinical treatments yet,” Greenblatt said.

Even after a person is on the road to recovery from an eating disorder, they may relapse. A relapse and a simple slip are two different things, though. “To differentiate between a slip and a relapse, a slip is engaging in a behavior/behaviors, but then getting back on track,” said Bonnie Brennan, senior clinical director of adult services at Eating Recovery Center Denver and a certified eating disorder specialist. “A relapse, however, is a pattern of slips that indicates returning to eating behaviors.”

Also, it’s important to note that people can relapse because they are trying to solve some other kind of problem – such as a medical procedure. For example, if they need to fast before a procedure, Brennan explains. What for some can be an innocent behavior, can be a trigger that can turn into something dangerous.

Signs of a relapse, according to Brennan, can include:

  • spending a lot of time thinking about food – including how much the person is eating and how they can get rid of it
  • dropping weight
  • re-engaging in eating disorder behaviors (i.e. restricting, purging, over exercising)
  • saying “it’s just this one time”
  • increased irritability, becoming more anxious, depressed, not engaging in things that normally would feel good
  • turning down social invitations
  • difficulty engaging in work and school

Scientists Editing the Human Embryo Here’s Why Baby Designer Is the Way Out

The announcement by researchers in Portland, Oregon that they’ve successfully modified the genetic material of a human embryo took some people by surprise.

With headlines referring to “groundbreaking” research and “designer babies,” you might wonder what the scientists actually accomplished. This was a big step forward, but hardly unexpected. As this kind of work proceeds, it continues to raise questions about ethical issues and how we should we react.

For a number of years now we have had the ability to alter genetic material in a cell, using a technique called CRISPR.

The DNA that makes up our genome comprises long sequences of base pairs, each base indicated by one of four letters. These letters form a genetic alphabet, and the “words” or “sentences” created from a particular order of letters are the genes that determine our characteristics.

Sometimes words can be “misspelled” or sentences slightly garbled, resulting in a disease or disorder. Genetic engineering is designed to correct those mistakes. CRISPR is a tool that enables scientists to target a specific area of a gene, working like the search-and-replace function in Microsoft Word, to remove a section and insert the “correct” sequence.

In the last decade, CRISPR has been the primary tool for those seeking to modify genes – human and otherwise. Among other things, it has been used in experiments to make mosquitoes resistant to malaria, geneticallymodify plants to be resistant to disease, explore the possibility ofengineered pets and livestock, and potentially treat some human diseases (including HIV, hemophilia and leukemia).

Up until recently, the focus in humans has been on changing the cells of a single individual, and not changing eggs, sperm and early embryos – what are called the “germline” cells that pass traits along to offspring. The theory is that focusing on non-germline cells would limit any unexpected long-term impact of genetic changes on descendants. At the same time, this limitation means that we would have to use the technique in every generation, which affects its potential therapeutic benefit.

Earlier this year, an international committee convened by the National Academy of Sciences issued a report that, while highlighting the concerns with human germline genetic engineering, laid out a series ofsafeguards and recommended oversight. The report was widely regarded as opening the door to embryo-editing research.

That is exactly what happened in Oregon. Although this is the first study reported in the United States, similar research has been conducted in China. This new study, however, apparently avoided previous errors we’ve seen with CRISPR – such as changes in other, untargeted parts of the genome, or the desired change not occurring in all cells. Both of these problems had made scientists wary of using CRISPR to make changes in embryos that might eventually be used in a human pregnancy. Evidence of more successful (and thus safer) CRISPR use may lead to additional studies involving human embryos.

First, this study did not entail the creation of “designer babies,” despite some news headlines. The research involved only early stage embryos, outside the womb, none of which was allowed to develop beyond a few days.

In fact, there are a number of existing limits – both policy-based and scientific – that will create barriers to implanting an edited embryo to achieve the birth of a child. There is a federal ban on funding gene editing research in embryos; in some states, there are also total bans on embryo research, regardless of how funded. In addition, the implantation of an edited human embryos would be regulated under thefederal human research regulations, the Food, Drug and Cosmetic Actand potentially the federal rules regarding clinical laboratory testing.

Beyond the regulatory barriers, we are a long way from having the scientific knowledge necessary to design our children. While the Oregon experiment focused on a single gene correction to inherited diseases, there are few human traits that are controlled by one gene. Anything that involves multiple genes or a gene/environment interaction will be less amenable to this type of engineering. Most characteristics we might be interested in designing – such as intelligence, personality, athletic or artistic or musical ability – are much more complex.

Second, while this is a significant step forward in the science regarding the use of the CRISPR technique, it is only one step. There is a long way to go between this and a cure for various disease and disorders. This is not to say that there aren’t concerns. But we have some time to consider the issues before the use of the technique becomes a mainstream medical practice.

Taking into account the cautions above, we do need to decide when and how we should use this technique.

Should there be limits on the types of things you can edit in an embryo? If so, what should they entail? These questions also involve deciding who gets to set the limits and control access to the technology.

We may also be concerned about who gets to control the subsequent research using this technology. Should there be state or federal oversight? Keep in mind that we cannot control what happens in other countries. Even in this country it can be difficult to craft guidelines that restrict only the research someone finds objectionable, while allowing other important research to continue. Additionally, the use of assisted reproductive technologies (IVF, for example) is largely unregulated in the U.S., and the decision to put in place restrictions will certainly raise objections from both potential parents and IVF providers.

Moreover, there are important questions about cost and access. Right now most assisted reproductive technologies are available only to higher-income individuals. A handful of states mandate infertility treatment coverage, but it is very limited. How should we regulate access to embryo editing for serious diseases? We are in the midst of awidespread debate about health care, access and cost. If it becomes established and safe, should this technique be part of a basic package of health care services when used to help create a child who does not suffer from a specific genetic problem? What about editing for nonhealth issues or less serious problems – are there fairness concerns if only people with sufficient wealth can access?

So far the promise of genetic engineering for disease eradication has not lived up to its hype. Nor have many other milestones, like the 1996cloning of Dolly the sheep, resulted in the feared apocalypse. The announcement of the Oregon study is only the next step in a long line of research. Nonetheless, it is sure to bring many of the issues about embryos, stem cell research, genetic engineering and reproductive technologies back into the spotlight. Now is the time to figure out how we want to see this gene-editing path unfold.