Why Does Hunger Vanish When You Ignore It Long Enough?

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Why Does Hunger Vanish When You Ignore It Long Enough?

Credit: WAYHOME studio/Shutterstock

Why is it that when you’re tremendously hungry, you’re able to forget about it if you’re in the middle of an intriguing activity, such as reading a good book?

It’s almost as if you’re able to ignore those hunger pangs until your task is complete, at which point the hunger can hit you hard.

Such a question might seem straightforward, but the answer is actually quite complex and perplexing, dietitians told Live Science. [Why Do Your Teeth Feel Weird After Eating Spinach?]

When a person is hungry, a cascade of triggers notifies the brain that the body needs food. One of those triggers is a hormone called ghrelin — “the only mammalian substance that has been shown to increase appetite and food intake when delivered to humans,” according to a 2006 review in thejournal Physiology and Behavior.

Most of the body’s supply of ghrelin is created in the stomach and duodenum (the first part of the small intestine). Once made, ghrelin can cross the blood-brain barrier and target certain parts of the brain, stimulating hunger, according to the review.

Moreover, ghrelin is with us 24/7: its levels drop as we eat, and rise before meals, reaching concentrations high enough to stimulate hunger, according to the review.

However, a curious finding shows that ghrelin isn’t the be-all and end-all of hunger pangs.

In a 2016 study in the journal Clinical Nutrition, 59 obese adults participated in an eight-week-long program in which they fasted every other day. (They ate sparingly on the “fast” days, and ate freely on alternate days.) But after measuring the participant’s ghrelin levels, the researchers found that “hunger was not related to ghrelin concentrations … at any point,” they wrote in the study.

In other words, when people fasted, their levels of ghrelin increased. But for unknown reasons, these people didn’t report feeling hungrier than usual.

“It’s interesting because the subjective “How hungry are you?” doesn’t really match up with what we measure clinically,” Colleen Tewksbury, a bariatric program manager at Penn Medicine, who was not involved with the review or the study, told Live Science.

So, why is it that people can basically ignore their hunger pangs? One idea, based on anecdotal observations, is that intense activities can distract people from their hunger, said Leah Groppo, a clinical dietician at Stanford Health Care in Palo Alto, California.

“If you’re really distracted, oftentimes people are able to lose that sense of hunger,” Groppo told Live Science. “Then, over time it [the feelings of hunger] will diminish because you’re still hyper-focused on something else.”

However, if you’re surrounded by enough cues to remind you of your hunger — say, you’re reading a novel but you’re by the kitchen, and the smell of dinner is wafting through the air — then you’ll likely remember how hungry you are.

Original article on Live Science.

Child Born with HIV is Virtually Virus-Free for 9 Years, Without Meds

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Child Born with HIV is Virtually Virus-Free for 9 Years, Without Meds

Child Born with HIV is Virtually Virus-Free for 9 Years, Without Meds
An illustration of the HIV virus in the blood stream.

Credit: Sebastian Kaulitzki | Shutterstock.com

A child in South Africa who was born with HIV has been virtually free of the virus for nearly nine years now and didn’t take anti-HIV drugs for most of that time, according to a new report of the case.

The child was treated with HIV medications early in life, but has not received anti-HIV drugs for eight and a half years, according to the researchers, who reported the case today (July 24) at an international AIDS conference in Paris.

The researchers hope that by studying this child, they may gain a better understanding of how a person’s body can, in some cases, control HIV without the use of daily drugs. Such further research may potentially lead to new, long-acting treatments for the disease. [27 Devastating Infectious Diseases]

“Further study is needed to learn how to induce long-term HIV remission in infected babies,” Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), said in a statement. “However, this new case strengthens our hope that by treating HIV-infected children for a brief period beginning in infancy, we may be able to spare them the burden of life-long therapy” and the health consequences of long-term HIV infection, Fauci said.

The South African child was diagnosed with HIV in 2007 at 32 days old. The child was enrolled in a study, funded by NIAID, that aimed to test the effects of early HIV treatment. Children in the study were randomly assigned to receive antiretroviral therapy (ART) drugs either immediately after their HIV diagnosis, or only once they showed symptoms of the disease.

The child in the new report received ART drugs immediately after diagnosis and continued receiving them for 40 weeks. After the treatment stopped, the researchers could no longer detect HIV in the child’s blood; and follow-up tests showed that the child remained healthy and HIV-free in the years following the treatment.

When the child was nine and a half years old, the researchers conducted rigorous testing to determine if HIV was present anywhere in the child’s body. They used very sensitive test, and found that a tiny proportion of the child’s immune cells contained the virus, but the virus was dormant. The researchers otherwise found no evidence of HIV — standard tests could not detect the virus and the child had no symptoms.

This isn’t the first time that early HIV treatment has led to apparent remission in a child. In 2013, researchers reported the case of a baby born with HIV in Mississippi who was treated with anti-HIV drugs just 30 hours after birth. In that case, the baby remained apparently HIV-free for more than two years without drug treatment, until the virus reappeared in her blood. In 2015, researchers in France reported the case of an HIV-positive child who began treatment at 3 months of age, but later stopped treatment and remained HIV-free more than 11 years later.

It’s not exactly clear why some children may be able to live so long without needing ongoing HIV treatment. It’s thought that early treatment with anti-HIV drugs may prevent the virus from establishing reservoirs, or “hiding places,” in the body, which allow the virus to reemerge when treatment stops.

It’s also likely that the South African child has other, innate factors that contributed to that person’s HIV remission, the researchers said. Among the 143 infants who received the same treatment — 40 weeks of ART immediately after diagnosis — the average length of remission was about 30 weeks, according to the Washington Post. Some children in the study were in remission for more than two years, but no others went as long as the 8.5 years that was seen in the current case.

“By further studying the child, we may expand our understanding of how the immune system controls HIV replication,” said study co-author Caroline Tiemessen, head of cell biology at South Africa’s National Institute for Communicable Diseases (NICD) in Johannesburg.

The U.S. National Institutes of Health is currently conducting a trial to test whether giving ART to HIV-infected babies within 48 hours of birth leads to long-term control of the virus after treatment is stopped.

Original article on Live Science.

Anorexia: Causes, Symptoms & Treatment

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Anorexia: Causes, Symptoms & Treatment

Credit: Christos Georghiou/Shutterstock

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

This article is for informational purposes only, and is not meant to offer medical advice.

This Is How a Woman Died from a Tick-Borne Disease Without a Tick Bite

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This Is How a Woman Died from a Tick-Borne Disease Without a Tick Bite

This image shows a Lone Star tick, which is thought to spread a virus similar to the severe fever with thrombocytopenia syndrome virus.

Credit: CDC

A woman in Japan died last year from a tick-borne disease — but she was never bitten by a tick.

Instead, investigators believe the woman became infected with a disease called severe fever with thrombocytopenia syndrome through a bite from a stray cat, according to The Japan Times. (Essentially, the cat was bitten by an infected tick, got infected and then passed that virus on to the woman.)

But what is severe fever with thrombocytopenia syndrome, and is it odd for a tick-borne disease to cut ticks out of the equation?

Severe fever with thrombocytopenia syndrome is caused by a virus of the same name: severe fever with thrombocytopenia syndrome virus, or SFTSV, according to the Centers for Disease Control and Prevention. The virus is spread primarily through ticks.

If you haven’t heard of SFTSV, it may be because no cases of the disease have been reported in the United States; rather, infections have been reported only in Asia. [10 Important Ways to Avoid Tick Bites]

SFTSV is considered an emerging infectious disease, and researchers are still learning about it, said Dr. Amesh Adalja, an infectious-disease specialist and a senior associate at the Johns Hopkins Center for Health Security, who was not involved in the Japanese woman’s case.

Suspected cases of the infection started to emerge in the mid-2000s, and scientists first isolated the virus in a lab in 2010, Adalja told Live Science.

An increase in diagnoses of SFTSV doesn’t necessarily mean that the virus is becoming more common, Adalja noted. Rather, doctors may be more aware of the disease and know to look for it, leading to the increase in documented cases.

The tick-borne virus causes general flu-like symptoms, including fever, headache, and aches and pains, Adalja said. But these common symptoms can be caused by a number of diseases. A cluster of cases in China in 2007, for example, was thought at one point to be caused by a form of typhus spread by mites or a bacterial infection spread by ticks, he said.

As the disease progresses, however, it can cause changes in a person’s blood, Adalja said. “Thrombocytopenia,” for example, means that a person doesn’t have enough platelets in their blood. Platelets help blood clot, so having fewer platelets can lead to bleeding problems. The virus can also lower the levels of white blood cells, which are cells that help the body fight infections, he said. [27 Devastating Infectious Diseases]

Eventually, SFTSV can lead to multiple-organ failure, Adalja said, meaning that various organs in the body shut down. Studies suggest that up to 30 percent of people who get the virus die, he noted.

Currently, there are no specific treatments for SFTSV, Adalja said. Instead, doctors treat the patients through supportive care.

Because there haven’t been any documented cases of SFTSV in the U.S., the disease isn’t something a doctor would normally look for, Adalja said. However, he added that the virus is similar to another infection that’s emerged stateside in recent years: the Heartland virus.

The Heartland virus is also a tick-borne disease, and studies have found that the two viruses are genetically related, Adalja said. In fact, animals infected with the Heartland virus may make antibodies for SFTSV, he said. A 2013 study, for example, found SFTSV antibodies in animals including sheep, goats and deer in Minnesota; it’s possible that the animals made the antibodies in response to the Heartland virus.

Mammal-to-mammal transmissions of SFTSV have been reported before, Adalja said. In 2012, researchers reported human-to-human transmission of SFTSV in China, he said. And a review of the virus published in the journal The Lancet in 2014 suggests that human-to-human transmission of SFTSV is possible.

“It’s not surprising” that the virus can be spread without a tick, Adalja said. “It’s not the main mechanism [of spreading], but it can happen.” If a virus is in an animal’s blood or body fluid and a person comes into contact with that blood or body fluid, the virus can spread, he said.

Originally published on Live Science.

Scientists Erase Heart Disease Defect in Human Embryos

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Scientists Erase Heart Disease Defect in Human Embryos

This sequence of images shows the development of human embryos after they were injected with a gene-correcting enzyme and sperm from a donor with a genetic mutation known to cause a type of heart disease.

Credit: OHSU

Editor’s Note: This story was updated on Aug. 2 at 5:00 p.m. E.T.

A group of scientists in Oregon has successfully modified the genes of embryos using CRISPR, a cut-and-paste gene-editing tool, in order to correct a genetic mutation known to cause a type of heart defect.

The experiments, which were described today (Aug. 2) in the journal Nature, were conducted by biologist Shoukhrat Mitalipov and colleagues at Oregon Health & Science University in Portland. Mitalipov conducted the experiments on dozens of single-celled embryos, which were discarded before they could progress very far in development, MIT Technology Review reported last week when the results were initially leaked. This is the first time that scientists in the United States have used this approach to edit the genes of embryos.

The CRISPR/Cas9 gene-editing system is a simple “cut and replace” method for editing precise spots on the genome. CRISPRS are long stretches of DNA that are recognized by molecular “scissors” called Cas9; by inserting CRISPR DNA near target DNA, scientists can theoretically tell Cas9 to cut anywhere in the genome. Scientists can then swap a replacement gene sequence in the place of the snipped sequence. The replacement sequence then gets automatically incorporated into the genome by natural DNA repair mechanisms.

In 2015, a group in China used CRISPR to edit several human embryos that had severe defects, though none were allowed to gestate very long before being discarded. The Chinese technique led to genetic changes in some, but not all of the cells in the embryos, and CRISPR sometimes snipped out the wrong place in the DNA.

The new results are a major advance compared with earlier efforts. In the new experiments, scientists eliminated the off-target effects of CRISPR/cas9.

The team used dozens of embryos that were created for in vitro fertilization (IVF), using the sperm of men who had a severe genetic defect. The sperm contained a single copy of the gene MYBPC3, which confers a risk of sudden death and heart failure due to thickening of the heart muscle known as hypertrophic cardiomyopathy.

In the new experiment, the team used Crispr/Cas9 to snip DNA at the location of the defective MYBPC3 gene in the fertilized eggs. Most of the embryos naturally repaired the break in the DNA by substituting the normal version of the gene, which originated in the egg. About two-thirds of the embryos did not contain the mutated version of the gene; and the team also eliminated the risk that some, but not all, of the cells in the embryos contained the edited genes.

In general, editing the germ line — meaning sperm, eggs or embryos — has been controversial, because it means permanently changing the DNA that is passed on from one generation to the next. Some scientists have called for a ban on germ-line editing, saying the approach is incredibly risky and ethically dubious.

However, a National Academy of Sciences report published earlier this year suggested that embryo editing could be ethical in the case of severe genetic diseases, assuming the risks could be mitigated.

Originally published on Live Science.

Editor’s Note: This story was updated to include additional information from the recently published journal article on the technique.

Rare Conjoined Bat Twins Found in Brazil

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Rare Conjoined Bat Twins Found in Brazil


The corpses of rare conjoined bats found in Brazil have given scientists a closer look into a phenomenon that has only ever been recorded twice before.When Marcelo Rodrigues Nogueira, a postdoctoral researcher in biology at the State University of Northern Rio de Janeiro first saw the bat twins, he was “completely astonished,” he wrote in an email to Live Science. “I have handled many bats [in my career], some with very impressive morphological characters (and bats are very special in this respect!), but none [were as] surprising as these twins.” [See Photos of the Rare Conjoined Bats Found in Brazil]

Only two other pairs of conjoined bat twins have been reported in the scientific literature, one in 1969 and another in 2015. 

Although it’s not known exactly what causes identical twins to be conjoined, the phenomenon is known to occur when a fertilized egg splits too late. If an egg splits four to five days after being fertilized, two separate identical twins will form. If, however, the splitting doesn’t occur until 13 to 15 days after fertilization, the fertilized egg will only separate partially, and the twins will be conjoined.

The researchers first became aware of the conjoined bats after the animals were donated to the Laboratory of Mastozoology at the Rural Federal University of Rio de Janeiro. No one from Nogueira’s team, which includes embryologists Nadja Lima Pinheiro and Adriana Ventura from the Area of Embryology at the Rural Federal University of Rio de Janeiro, saw the twins right when they were found. Because of this, the scientists, aren’t certain if the twins were stillborn or if they had died shortly after birth.

These conjoined bat twins, found under a mango tree in southeastern Brazil in 2001, were either stillborn or died shortly after birth.

These conjoined bat twins, found under a mango tree in southeastern Brazil in 2001, were either stillborn or died shortly after birth.

Credit: Dr. Nadja L. Pinheiro

The bats, found under a mango tree in southeastern Brazil in 2001, are dicephalic parapagus conjoined twins, which means they’re oriented side by side with their whole trunks conjoined. X-rays revealed that the twins’ spines form a “Y” shape, with two separate columns of vertebrae branching off at the lower back. Ultrasound images also revealed two hearts of equal size that researchers suspect are separate, the scientists said.

Since most bats have only one pup per litter, finding even nonconjoined bat twins is rare. In the five years Daniel Urban, a postdoctoral research associate in evolutionary developmental biology at the University of Illinois at Urbana-Champaign, has been studying bats, he’s only ever seen a single pup flying around or hanging onto its mother, he told Live Science. Urban was the lead author of the 2015 study on conjoined bat twins that was published in the journal Acta Chiropterologica.

It’s even harder to find bat twins that are conjoined. But this doesn’t mean conjoined twins are rarer in bats than in any other mammals, according to Scott Pedersen, a professor of biology and microbiology at South Dakota State University, who was not involved in the new study. It’s just that humans find out about conjoined bats less often than they find out about other conjoined animals, he told Live Science in an email. [Image Gallery: Evolution’s Most Extreme Mammals]

Even if conjoined bats are alive when they are born, it’s likely that they’ll die soon after, because their bodies can’t sustain them, Pedersen said. Bats also tend to live in places humans aren’t located, which means even if a person were to venture into a bat’s domain, the person would need to find the conjoined bats before they degraded or were scavenged.

This is only made more unlikely by the fact that bats are nocturnal, said Urban. If a mother gives birth to conjoined bats during the day, it will likely be in a protected roost, which means people wouldn’t see them. She may give birth while she’s out in the open, but that would occur only at night, when the twins would be obscured by darkness, Urban said.

“If you combine all these factors together, it’s amazing we even have any [conjoined bat twins],” he added.

This X-ray shows that the spines of these conjoined bat twins are joined at their lower backs.

This X-ray shows that the spines of these conjoined bat twins are joined at their lower backs.

Credit: Laboratório de Radiografias, Divisão de Vertebrados, Museu Nacional – UFRJ

Although little is known about the organs of the recently discovered conjoined bat twins, the researchers have opted not to use any invasive methods to further investigate the animals’ bodies.

“It’s so rare and precious that you find something like this, you don’t want to do any type of destructive sampling to look further. You’re, of course, very curious about it, but they’re a one-shot deal so, for the most part, they’re held onto until the future where a newer technology will allow us to pursue it further without completely damaging what we already have,” Urban said.

The new study was published online June 16 in the journal Anatomia Histologia Embryologia.

Original article on Live Science.