Author: IGIHE

{The quest to develop a cure for HIV has long been plagued by a seemingly simple question: How do doctors determine if someone is cured? The virus has a knack for lying dormant in immune cells at levels undetectable to all but the most expensive and time-consuming tests.}

Scientists at the University of Pittsburgh’s Graduate School of Public Health announced in Nature Medicine that they’ve created a test sensitive enough to detect “hidden” HIV, and yet is faster, less labor-intensive and less expensive than the current “gold standard” test.

The new Pitt test also revealed that the amount of virus lurking dormant in people who appear to be nearly cured of HIV is about 70-fold larger than previous estimates.

“Globally there are substantial efforts to cure people of HIV by finding ways to eradicate this latent reservoir of virus that stubbornly persists in patients, despite our best therapies,” said senior author Phalguni Gupta, Ph.D., professor and vice chair of Pitt Public Health’s Department of Infectious Diseases and Microbiology. “But those efforts aren’t going to progress if we don’t have tests that are sensitive and practical enough to tell doctors if someone is truly cured.”

HIV spreads by infecting CD4+ T cells, which are a type of white blood cell that plays a major role in protecting the body from infection. Antiretroviral therapies to treat HIV have advanced to the point that people with HIV can have the virus so well-controlled that they could have as little as one infectious virus per million CD4+ T cells.

However, the majority of HIV DNA integrated into these cells is defective, meaning it wouldn’t cause infection anyway. Once HIV therapy is working, it becomes critical to determine if the HIV DNA being detected by a test could actually create more virus and cause the person to relapse if therapy is stopped. Therefore, the test must be able to show that the virus it detects can replicate — typically by growing the virus from the sample.

To date, the best test available to do this is called a “quantitative viral outgrowth assay,” or Q-VOA. This test has many drawbacks: It may provide only a minimal estimate of the size of the latent HIV reservoir; requires a large volume of blood; and is labor-intensive, time-consuming and expensive.

Gupta’s team developed a test that they call TZA. It works by detecting a gene that is turned on only when replicating HIV is present, thereby flagging the virus for technicians to quantify.

The TZA test produces results in one week compared to the two weeks needed using the Q-VOA, and at a third of the cost. It also requires a much smaller volume of blood and is less labor-intensive.

“Using this test, we demonstrated that asymptomatic patients on antiretroviral therapy carry a much larger HIV reservoir than previous estimates — as much as 70 times what the Q-VOA test was detecting,” said Gupta. “Because these tests have different ways to measure HIV that is capable of replicating, it is likely beneficial to have both available as scientists strive toward a cure.”

Because of its low cell requirement, the TZA also may be useful for quantification of replication-competent HIV-1 in the pediatric population, as well as in the lymph nodes and tissues where the virus persists.

Source:Science Daily

{The visual cortex, the human brain’s vision-processing centre that was previously thought to mature and stabilize in the first few years of life, actually continues to develop until sometime in the late 30s or early 40s, a McMaster neuroscientist and her colleagues have found. Kathryn Murphy, a professor in McMaster’s department of Psychology, Neuroscience and Behaviour, led the study using post-mortem brain-tissue samples from 30 people ranging in age from 20 days to 80 years.}

Her analysis of proteins that drive the actions of neurons in the visual cortex at the back of the brain recasts previous understanding of when that part of the brain reaches maturity, extending the timeline until about age 36, plus or minus 4.5 years.

The finding was a surprise to Murphy and her colleagues, who had expected to find that the cortex reached its mature stage by 5 to 6 years, consistent with previous results from animal samples and with prevailing scientific and medical belief.

“There’s a big gap in our understanding of how our brains function,” says Murphy. “Our idea of sensory areas developing in childhood and then being static is part of the challenge. It’s not correct.”

The research appears May 29 in The Journal of Neuroscience.

Murphy says treatment for conditions such as amblyopia or “lazy eye,” for example, have been based on the idea that only children could benefit from corrective therapies, since it was thought that treating young adults would be pointless because they had passed the age when their brains could respond.

Though the research is isolated to the visual cortex, it suggests that other areas of the brain may also be much more plastic for much longer than previously thought, Murphy says.

Source:Science Daily

{If the mother is stressed over a longer period of time during pregnancy, the concentration of stress hormones in amniotic fluid rises, as proven by an interdisciplinary team of researchers from the University of Zurich. Short-term stress situations, however, do not seem to have an unfavorable effect on the development of the fetus.}

The feeling of constantly being on edge, always having to take care of everything, not being able to find a balance: If an expectant mother is strongly stressed over a longer period of time, the risk of the unborn child developing a mental or physical illness later in life — such as attention deficit hyperactivity disorder (ADHD) or cardiovascular disease — increases. The precise mechanism of how stress affects the baby in the womb is not yet been completely clarified. In cooperation with the University Hospital Zurich and the Max Planck Institute Munich, researchers of the University of Zurich have discovered that physical stress to the mother can change the metabolism in the placenta and influence the growth of the unborn child.

Stress hormone affects the growth of the fetus

When stressed, the human body releases hormones to handle the higher stress, such as the so-called corticotropin-releasing hormone (CRH), which results in an increase in stress hormone cortisol. This mechanism also persists during pregnancy, and the placenta, which supplies the fetus with nutrients, can also emit stress hormone CRH. As a result, a small amount of this hormone enters the amniotic fluid and fetal metabolism. Animal studies have shown that this hormone can boost the development of the unborn child: Unfavorable growth conditions in the woman lead to an increased release of the hormone, thereby improving the chances of survival in case of a premature birth. Under certain circumstances, however, this increase can also have negative consequences: “An excessive acceleration of growth may occur at the expense of the proper maturation of the organs,” says Ulrike Ehlert, psychologist and program coordinator.

{{Short-term stress — no effect}}

How does mental stress to the mother affect the release of stress hormones in the placenta? The research team tested 34 healthy pregnant women, who took part in amniocentesis within the scope of prenatal diagnostics. Such a test constitutes a stress situation for the expectant mother as her body secretes cortisol in the short term. To determine whether the placenta also releases stress hormones, the researchers compared the cortisol level in the mother’s saliva with the CRH level in the amniotic fluid — and determined that there was no connection: “The baby obviously remains protected against negative effects in case of acute, short-term stress to the mother,” Ehlert concludes.

{{Longer-term stress can be measured in amniotic fluid}}

The situation of the results regarding prolonged stress is completely different, as was determined using questionnaires for diagnosing chronic social overload: “If the mother is stressed for a longer period of time, the CRH level in the amniotic fluid increases,” says Pearl La Marca-Ghaemmaghami, psychologist and program researcher. This higher concentration of stress hormone in turn accelerates the growth of the fetus. As a result, the effect of the hormone on growth is confirmed, as has been observed in animals such as tadpoles: If their pond is on the verge of drying out, CRH is released in tadpoles, thereby driving their metamorphosis. “The corticotropin-releasing hormone CRH obviously plays a complex and dynamic role in the development of the human fetus, which needs to be better understood,” La Marca-Ghaemmaghami summarizes.

{{Strengthening mental resources with specialized help}}

The psychologists advise pregnant women who are exposed to longer-term stress situations to “seek support from a therapist to handle the stress better.” Stress during pregnancy cannot always be avoided, however. “A secure bond between the mother and child after the birth can neutralize negative effects of stress during pregnancy,” La Marca-Ghaemmaghami says.

Source:Science Daily

{We have always been told that exercising regularly, getting at least seven hours of sleep every night, eating low-calorie diet and not smoking would help us live longer but there’s something else we need to add to the list.}

According to a study by English researchers, making love regularly can help you live longer, a report on Psychology Today claims.

To arrive at this conclusion, the researchers surveyed the sexual frequency of 918 reasonably healthy male in a Welsh village called Caerphilly.

The men were between the ages of 45 to 59 when the study started and the researchers checked back with the men a decade later.

Ten years later, 150 out of the 918 men had died – 67 from heart attack and 83 from other causes.

After the researchers correlated the sexual frequency of the men as reported in the original survey, the researchers found that men who have sex just once a month were less likely to live longer than men who had sex twice a week.

What are your thoughts about the research? Do you believe having more sex can make you live longer?

Source:Elcrema