29 Feb

Medical News Today: Overweight, obesity linked to poorer memory for young adults

It is well established that being overweight can raise the risk of diabetes, heart disease and stroke. But according to a new study, it may also have consequences for cognitive health; researchers found that young adults who were overweight or obese had poorer episodic memory than their healthy-weight peers.
[An overweight man trying to think]
Young adults who are overweight or obese may have poorer episodic memory, new research suggests.

Study coauthor Dr. Lucy Cheke, of the Department of Psychology at the University of Cambridge in the UK, and colleagues publish their findings in The Quarterly Journal of Experimental Psychology.

According to the Centers for Disease Control and Prevention (CDC), around 69% of American adults aged 20 and older are overweight or obese, putting them at greater risk for numerous health problems, including high blood pressure, heart disease, type 2 diabetes and some types of cancer.

Increasingly, researchers have found that excess weight may also impact brain health. Last September, for example, Medical News Today reported on a study that linked overweight and obesity in midlife to earlier onset of Alzheimer’s disease.

“While the physical health impacts of obesity are increasingly well understood, recent research indicates that there may be a significant psychological element to the obese syndrome,” the authors note, “with proposals that cognitive deficits may occur both as a result of obesity and potentially as a causal factor in its emergence.”

Higher BMI linked to poorer performance on memory test

To further investigate this link, Dr. Cheke and colleagues enrolled 50 young adults aged 18-35 to their study, which investigated how body mass index (BMI) may influence episodic memory – the ability to recall past events.

All participants had a BMI of 18-51; a BMI of 18-25 was deemed healthy, 25-30 was considered overweight and 30 or over was classified as obese.

Subjects were required to complete a memory test called the “Treasure-Hunt Task,” which involved hiding a number of objects around complex scenery – such as a desert with palm trees – on a computer screen over a 2-day period. Participants were then asked to recall which objects they had hidden and when and where they hid them.

Compared with participants who had a healthy BMI, the team found that those whose BMI fell into the categories of overweight or obese had a poorer performance on the memory task, with performance worsening as BMI increased.

The researchers say their findings indicate that a higher BMI may lead to structural and functional changes in the brain that reduce the ability to form and recall episodic memories.

What is more, the team says reduced episodic memory as a result of higher BMI may also have a negative impact on a person’s ability to adhere to a healthy diet.

Dr. Cheke explains:

“We’re not saying that overweight people are necessarily more forgetful, but if these results are generalizable to memory in everyday life, then it could be that overweight people are less able to vividly relive details of past events – such as their past meals. Research on the role of memory in eating suggests that this might impair their ability to use memory to help regulate consumption.

In other words, it is possible that becoming overweight may make it harder to keep track of what and how much you have eaten, potentially making you more likely to overeat.”

The authors note that their study was small and preliminary, so further research is warranted to confirm the findings and determine whether they may apply to older adults who are overweight or obese.

Still, the team believes the study brings us a step closer to gaining a better understanding of the psychological factors that may drive obesity.

“By recognizing and addressing these psychological factors head-on,” notes study coauthor Dr. Jon Simons, also of the Department of Psychology at Cambridge, “not only can we come to understand obesity better, but we may enable the creation of interventions that can make a real difference to health and well-being.”

Earlier this month, a study reported by MNT found that a person’s health behavior and obesity risk may be influenced by their neighborhood.

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Source: medicalnewstoday

29 Feb

Medical News Today: Gum disease bacteria linked to esophageal cancer

In a new study, researchers propose for the first time that Porphyromonas gingivalis – the bacterium behind gum disease – could be a risk factor for esophageal cancer.
Esophagus in neon model
The researchers found levels of P. gingivalis were significantly higher in the cancerous tissue of ESCC patients than in surrounding tissue or tissue of normal controls.

The researchers, from the University of Louisville (UofL), KY, and Henan University of Science and Technology in Luoyang, China, report their findings in the journal Infectious Agents and Cancer.

According to the Centers for Disease Control and Prevention (CDC), every year, around 15,000 people in the US are diagnosed with esophageal cancer – a cancer that starts in the esophagus or gullet, the muscular tube that moves food from the throat into the stomach.

The lining of the esophagus is made of two kinds of cell, which is why there are two main types of esophageal cancer: esophageal adenocarcinoma and esophageal squamous cell carcinoma (ESCC). ESCC is more common in developing countries.

Known risk factors for esophageal cancer include chemical exposure, diet, heredity and age – all factors already common to many other cancers.

The cancer is hard to diagnose in the early stages. For many patients, the cancer develops rapidly after diagnosis and the prognosis is not good.

For their study, the team tested tissue from 100 patients with ESCC and 30 patients who did not have the disease (the controls).

They tested samples taken from three types of esophageal tissue: cancerous tissue, non-cancerous tissue adjacent to cancerous tissue and normal tissue from the controls.

Bacterium present in 61% of cancerous tissue samples

The team found P. gingivalis was present in 61% of cancerous tissue samples and only 12% of adjacent tissue samples. They found none in the normal tissue samples.

Fast facts about esophageal cancer

  • The risk for developing esophageal cancer increases with age
  • Less than 15% of cases are in people younger than 55
  • The disease is three to four times more common in men than women.

Learn more about esophageal cancer

Co-senior author Huizhi Wang, assistant professor of oral immunology and infectious diseases at the UofL School of Dentistry, says:

“These findings provide the first direct evidence that infection could be a novel risk factor for ESCC, and may also serve as a prognostic biomarker for this type of cancer.”

He notes that if these findings are confirmed, then it could mean that eradication of a common oral bacterium could help reduce the significant number of people who develop ESCC.

To detect P. gingivalis in the tissue samples, the researchers measured expression of lysine-gingipain, an enzyme unique to the bacterium. They also looked for DNA traces of the bacterial cell.

They found levels of both the enzyme and the bacterial DNA were significantly higher in the cancerous tissue of ESCC patients than in surrounding tissue or tissue of normal controls.

The team found that levels of P. gingivalis measures were in line with levels of other measures, such as extent of cancer cell differentiation, metastasis (extent of spread) and overall survival rate.

Speculating on possible explanations, Prof. Wang offers two. Either ESCC cells are a “preferred niche” for the bacterium to thrive in, or infection with the bacterium somehow spurs the development of the cancer.

If the reason is that the cancer cells offer the bacterium a niche, then simple antibiotics could be a way forward for treatment. Another approach could be to use genetic technology to target the bacterium and ultimately eliminate the cancer cells.

Prof. Wang says should further studies actually prove that P. gingivalis causes ESCC, then the implication would be enormous, and:

“It would suggest that improving oral hygiene may reduce ESCC risk; screening for P. gingivalis in dental plaque may identify susceptible subjects; and using antibiotics or other antibacterial strategies may prevent ESCC progression.”

Meanwhile, Medical News Today recently learned about another study that shows patients with chronic kidney disease who also have severe gum disease have a higher risk of death than chronic kidney disease patients with healthy gums.

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Source: medicalnewstoday

29 Feb

Medical News Today: 'IVF chip' helps capture images of sperm fusing with egg

Every mammal on this planet starts in the same way: a sperm encounters an egg and fuses with it. This process is familiar to every eighth grade biology student, and pictures of the event can be found in every biology text book. However, despite this ubiquity, the detailed mechanics of the process itself is still somewhat of a mystery.
sperm fusing with egg
The researchers filmed the gradual fusing of a mouse sperm cell with a mouse’s egg cell; these images show over 100 minutes of the sperm cell slowly being assimilated into the membrane and the cytoplasm of the egg cell.
Image credit: Benjamin Ravaux

Now, new techniques – featuring an “IVF chip” – presented recently at the Biophysical Society’s 60th annual meeting in Los Angeles, CA, promise to reveal new insights into how a single sperm cell fuses with an egg cell.

The researchers hope the new techniques will help us better understand the causes of infertility and improve treatments.

At the meeting, Benjamin Ravaux, a physics graduate student at the Ecole Normale Supérieure de Paris in France, described how, using the “completely new approach,” he and his colleagues captured high-resolution images of the events that unfold at the membrane of the egg cell during mammalian fertilization.

Ravaux says the “IVF chip” is a “unique tool to observe the cascade of molecular and membrane events occurring during the fertilization process,” under conditions that mimic what happens in nature.

The idea and design of the device are the product of expertise in biophysics and fertilization and assisted reproduction technologies (ART) – including in vitro fertilization (IVF).

At the heart of the new approach is an “IVF chip” – a microfluidic device made from an electronic chip comprising several layers of silicon polymer sealed on a glass slide.

The design of the chip allows a sperm cell to be held in the bottom layer with an egg cell held above it, inside an “egg cup.” At the bottom of the egg cup is a tiny opening, with a width of about 30 microns (roughly half the width of human hair).

Images of fertilization ‘as it occurs’

When inserted in the lower layer of the chip, a sperm cell swims through the opening and fuses with the egg held in the egg cup.

The chip is compatible with confocal microscopy and other imaging systems, allowing the researchers to capture high-resolution images and movies of the fertilization process as it occurs.

The images show what happens to the sperm cell when it encounters the membrane of the egg cell. They show the two cells merging their membranes over time and the sperm cell gradually sinking into the egg cell.

The scientists also saw how the DNA in the sperm was assimilated into the egg’s cytoplasm – the fluid surrounding the nucleus of the egg cell.

Ravaux explains that the new technique offers scientists the chance to investigate an area of reproductive biology that has remained largely unexplored due to lack of tools.

The IVF chip is different to what has been tried before because it allows scientists to observe what happens when just one sperm cell fuses with an egg. Other attempts to do this have had to settle with observing multiple sperm cells coming into contact with the membrane of the egg cell.

Ravaux says the technique could be combined with other approaches – such as fluorescent antibodies or genetically modified animals – to offer new insights into the membrane events of the sperm-meets-egg process. He concludes:

“An enhanced understanding of the molecular and physical mechanisms responsible for fertilization could ultimately lead to better methods to diagnose the causes of infertility, and improved personalized medicine treatments.”

From a study published recently, Medical News Today learned how scientists in China have created functioning sperm from stem cells, raising hope that the approach may one day be used to treat male infertility.

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Source: medicalnewstoday

29 Feb

Medical News Today: Could tarantula venom help fight pain?

Tarantula venom may be good for us after all, says research being presented at the Biophysical Society’s 60th Annual Meeting in Los Angeles, CA. It seems that individual peptide toxins could be useful as painkillers.
[tarantula venom pain killer]
Green tarantula venom could hold the key to new types of pain control.
Image credit: Henriques, University of Queensland.

If a human gets bitten by certain spiders, snakes or cone snails, the venomous toxins can be potent enough to kill or, at least, cause a serious reaction.

Meanwhile, millions of people worldwide live with chronic and neuropathic pain, which current treatments only partially relieve. The existing therapies can also cause severe drowsiness or other sleep problems and can be highly addictive.

Researchers have therefore been hunting down potential candidates that could offer a better solution. They are also seeking a greater understanding of exactly how molecules act to reduce pain.

New and alternative painkillers could improve the quality of life of many people who experience chronic pain.

As part of this effort, a team from the University of Queensland in Brisbane, Australia has been investigating ProTx-II, a peptide toxin found in the venom of the Peruvian green velvet tarantula, Thrixopelma pruriens.

Characteristics of ProTx-II include high potency and selectivity to inhibit the pain sensation receptor. These factors, the team says, make it an ideal candidate as a future painkiller.

Scientists already knew that ProTx-II binds to the pain receptor located within the membrane of neuronal cells. What has remained unclear, however, is where the binding takes place, or what role the cell membrane plays in inhibiting the activity of ProTx-II.

How does ProTx-II inhibit the pain receptor?

To find out more, the researchers have been looking at the structure, the membrane-binding properties and the inhibitory activity of ProTx-II and a number of analogs.

They used nuclear magnetic resonance (NMR) spectroscopy to collect 3D evidence that enabled them to examine the structure and its role in inhibiting the pain receptor.

The scientists wanted to find out how the peptide and the neuronal cell membrane interact. They also hoped to identify the molecular properties of the peptide that interacted with and inhibited the pain receptor. To do this, they used surface plasmon resonance and fluorescence methodologies, as well as molecular simulations.

The results indicate that the cell membrane plays an important part in enabling ProTx-II to inhibit the pain receptor. The neuronal cell membranes attract the peptide to the neurons, intensifying its concentration close to the pain receptors. The peptide then locks in the right orientation to allow maximum interaction with the target.

This is the first study to describe the importance of the membrane-binding properties of ProTx-II for its potency as an inhibitor of Nav 1.7, an important pain receptor.

Sónia Troeira Henriques, senior research officer at the University of Queensland’s Institute for Molecular Bioscience, explains that finding out more about how this toxin works could help with the design of new pain therapeutics.

Medical News Today asked Henriques if other creatures could offer the same benefits.

She told us:

“Many toxins have been isolated from venoms from several creatures, e.g. cone snails, spiders, anenome, etc., and have been found to bind to pain sensation receptors. A very famous case is the toxin Prialt, or Ziconotide, that is a marketed drug used as analgesic and it was first identified in a cone snail.”

Apart from Nav 1.7, the cell membrane contains other channels that are implicated in a number of physiological processes, such as muscle and nerve relaxation, blood pressure regulation and sensory transduction.

Since these functions are associated with various disorders, the researchers hope their discoveries will reveal new targets for treating neuromuscular disease, neurological disorders and inflammatory and neuropathic pain.

They are now working on new toxins with greater affinity for the cell membrane and reduced side effects.

Two venomous spiders found in the US include the black widow and the brown recluse, mostly in the Southern and Western or Midwestern states. While rarely causing death, a bite can cause symptoms ranging from a rash to difficulty breathing and high blood pressure. Bites will need medical attention.

MNT reported last year on other research showing that venom from spiders could block pathways to reduce pain.

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Source: medicalnewstoday

29 Feb

Medical News Today: Turmeric: Health Benefits, Nutritional Information

Turmeric is a perennial plant of the ginger family, native to southwest India. Turmeric is commonly consumed in powder form and used as a spice.

To make turmeric powder, the leaves of the plant are boiled for 30-45 minutes, dried in ovens and then ground into a deep orange-yellow powder. Turmeric powder is a common spice used in Indian and Pakistani cuisine. It is a major component of curry and can also be used for dyeing cloth.

There are three naturally occurring phytochemicals in turmeric: curcumin, demethoxycurcumin and bisdemothoxycurcumin, together referred to as curcuminoids.

This MNT Knowledge Center feature is part of a collection of articles on the health benefits of popular foods. It provides a nutritional breakdown of turmeric and an in-depth look at its possible health benefits, how to incorporate more turmeric into your diet and any potential health risks of consuming turmeric.

Nutritional breakdown of turmeric

Turmeric root and powder.
Turmeric has been used in Ayurvedic and Chinese medical practice to treat multiple health issues.

According to the USDA National Nutrient Database, one tablespoon of turmeric powder contains 29 calories, 0.9 grams of protein, 0.3 grams of fat and 6.3 grams of carbohydrates (including 2 grams of fiber and 0.3 grams of sugar).1

That same 1 tablespoon serving provides 26% of your daily manganese needs, 16% of iron, 5% of potassium and 3% of vitamin C.

Turmeric has traditionally been used in Ayurvedic and Chinese medicine to treat inflammatory conditions, skin diseases, wounds, digestive ailments and liver conditions.

Possible benefits of consuming turmeric

Curcumin is the active substance in turmeric believed to be the source of its many health benefits. Curcumin is also responsible for turmeric’s distinctly earthy, slightly bitter and peppery flavor.

Digestion

Curcumin may help improve digestion by stimulating the gallbladder to produce bile. A double-blind, placebo-controlled study showed that turmeric reduced bloating and gas in people suffering from indigestion. The German Commission E, a group that determines which herbs can safely be prescribed in Germany, has approved the use of turmeric for digestive problems.2

Inflammation

Curcumin lowers the levels of two enzymes in the body that cause inflammation, which may indicate that consuming turmeric would be helpful in treating many inflammatory conditions.2

Inflammation is a common thread that links the following conditions:

Curcumin shows promise as a natural anti-inflammatory treatment and is currently being tested in phase 2 and 3 clinical trials.3

In a clinical study on curcumin’s effects on arthritis, 50 patients were given curcumin daily for 3 months. An increase in walking performance and distance was observed, as well as decreased inflammation levels.3

Curcumin has also been shown to be effective for inflammatory bowel diseases, such as Crohn’s disease and ulcerative colitis. In multiple studies, people with inflammatory bowel diseases who were given curcumin supplements experienced a reduction in symptoms.3

Heart health

Platelets in the blood.
Turmeric may reduce the risk of blood clot formation by preventing platelets from clumping together.

Turmeric has been shown to prevent blood platelets from clumping together, which may decrease the risk of blood clot formation. Early studies suggest that turmeric may help prevent the build-up of plaque in the arteries. In animal studies, turmeric extract lowered LDL (bad) cholesterol and prevented further accumulation.2

However, in a human study where participants were given 4 grams of curcumin per day, cholesterol levels were not improved.2

The anti-inflammatory properties of turmeric benefit cardiovascular health. Some studies have found that turmeric’s antioxidant and anti-inflammatory properties have produced the following effects in animal models:3

  • Reduced body weight
  • Lowered triglyceride synthesis
  • Increased basal metabolic rate
  • Increased fatty acid oxidation
  • Improved insulin sensitivity.

All of these effects would lower the risk of heart disease. The findings of these studies need to be replicated in humans before turmeric is used as a form of treatment, however.


On the next page, we look at further potential health benefits associated with turmeric, along with ways of incorporating more into your diet and possible health risks.

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Source: medicalnewstoday

28 Feb

Medical News Today: A lesson in paying attention from a brown bat

Our ability to focus solely on relevant sensory information is a skill that we all take for granted. Research into where in the brain this talent resides is scant. New research using bats, published in Proceedings of the National Academy of Sciences, digs a little deeper.
[Big brown bat]
New research using bats gives an intriguing insight into how mammals focus their attention.

For the entirety of our waking lives, our senses are bombarded by sensory stimulation.

It is easy to forget how much information flows through our senses every second of the day; our brains are so astute at presenting our consciousness with only the information that is important to us.

For instance, as you read this, you are probably seated. Your nether regions are nested against a chair, and your body weight is pushing down on your buttocks.

When you focus on this fact, you can feel the weight bearing down on your gluteus maximus. But before this was brought to your attention, that information was far from your focus.

Perhaps, if you are lucky, and you strain your ears, you can hear some distant birds. Until you consciously listen for them, however, their songs are as good as absent.

The mammalian brain is excellent at prioritizing inputs to ensure that the world is presented to us in a way that we can handle. If we were to focus on every single item that our senses detected, we would surely go mad.

Researchers at Johns Hopkins University have made new discoveries in the brains of bats that help us to understand how mammals pay such laser-guided attention.

Bats and sonar

Bats hunt by making sounds, then listening to them as they bounce back off any objects in front of them. This incredible use of sonar allows them to hunt during the darkest hours, a time when insects are off their guard and they can hunt in relative safety.

To use echolocation, the bats must be able to distinguish the echoes that their vocalizations make among a field of extraneous noise, including other bats’ calls and their echoes, insects, trees, aircraft and cars.

Lead author Melville J. Wohlgemuth, a postdoctoral fellow in the Krieger School of Arts and Sciences’ Department of Psychological and Brain Sciences, says:

“The bat brain has developed special sensitivities that allow it to pick out sounds from the environment that are pertinent to the animal. We were able to uncover these sensitivities because we used the perfect stimulus – the bat’s own vocalizations.”

Wohlgemuth and co-author Cynthia F. Moss, a Johns Hopkins professor and neuroscientist, set out to understand which sounds bats deemed important enough to pay attention to; they wanted to discover what kind of noise would be of enough interest to make the bats orient toward the sound.

Brain scans and the superior colliculus

The researchers used five big brown bats (Eptesicus fuscus), playing them a selection of different sounds while monitoring the activity in a specific section of their midbrain known as the superior colliculus.

The superior colliculus (SC) is known to play a role in collating sensory information and issuing the correct motor response, for instance, moving away from a threatening sound or toward one that sounds like food.

The researchers played bats a series of sounds, from natural vocalizations produced during a hunt, to white noise, and a selection of sounds ranging between the two extremes. All of the noises were equal in amplitude, bandwidth and duration.

The team found that the sensorimotor neurons in the ventral region of the SC responded to all of the sounds that were played, artificial or bat-based; however, neurons in the dorsal sensory regions of the SC only responded to natural bat-produced hunting sounds.

The following video from Johns Hopkins explains the experiment:

[embedded content]

Relevance to human attention

Because mammalian brains have great inter-species similarities, these findings are probably relevant for the human brain, too. The superior colliculus is known to be involved in directing eye movements in humans; Medical News Today asked Wohlgemuth whether the results might have implications for visual attention as well as sound, and he said:

“The superior colliculus is a multimodal structure that uses visual, auditory and somatosensory information to control orienting motor responses.

I believe that the results we found for auditory selectivity do indeed apply to other sensory systems, such as selecting a stimulus for visual orientation.”

MNT asked Wohlgemuth whether he will continue his research into this most fascinating of mammals. He next plans to investigate bats while hunting prey items; his “future experiments will involve examining how the bat processes the actual sensory information being used for target tracking.”

This fascinating and, at first, intractable area of neuroscience may soon yield more of its secrets. MNT recently covered research on the effect of flame retardants on children’s attention spans.

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Source: medicalnewstoday

28 Feb

Medical News Today: A little alcohol in pregnancy puts future generations at risk

Even a small dose of alcohol during pregnancy can increase the risk of alcoholism in the next three generations, according to a study published in Alcoholism: Clinical and Experimental Research.
[pregnant woman with wine]
Drinking during pregnancy can have a lifelong impact on offspring.

Previous studies have shown that alcohol use and related disorders pose a significant threat to global health. Exposure to moderate amounts of alcohol in utero or during early life puts humans at greater risk for alcohol abuse in adolescence and adulthood.

Factors affecting teen drinking habits are varied and complex. They include the desire to engage in risk-taking and rebellious behavior, as well as the wish to impress and to sustain popularity among peers.

Alcohol exposure can begin early, during pregnancy, through breastfeeding or when participating in festive occasions. One study shows that 39% of 8-10-year-old children in Pennsylvania had drunk or sipped alcohol.

The contexts in which alcohol is consumed have been linked to the quantities and rates of consumption, affecting the decision to partake of a glass of wine with dinner or indulge in a binge-drinking session.

Scientists have found a significantly higher rate of alcohol use disorder among adolescents born to mothers who consumed three or more drinks when pregnant, compared with those whose mothers did not drink.

An increased propensity to drink is thought to be linked to prenatal alcohol exposure (PAE) altering the neurophysiological response to the challenge of alcohol.

Between 10-15% of American women are estimated to drink some alcohol during pregnancy.

Just four glasses can affect offspring

Nicole Cameron, assistant professor of psychology at Binghamton University in New York, and colleagues collaborated with Michael Nizhnikov, of South Connecticut University, to investigate the effects of alcohol consumption during pregnancy on alcohol-related behavior in future generations.

To examine the effect, they gave pregnant rats the equivalent of one glass of wine each day for 4 consecutive days, during the rat equivalent of the second trimester in humans.

They then tested young offspring of both genders for water or alcohol consumption over two subsequent generations, to find out if rats whose mothers or grandmothers had consumed alcohol while pregnant were more likely to consume it themselves.

To evaluate sensitivity to alcohol, they looked at the righting reflex, or the ability to return the body to its default position, in this case, from lying down to standing up.

Adolescent male rats received a high dose of alcohol, which rendered them unresponsive and drunk on their backs. The team measured how long it took the rats to recover their senses and get back on their four paws.

Results showed that rats whose mothers or grandmothers consumed the equivalent of one glass of wine four times during the pregnancy, were more likely to have a preference for alcohol themselves, and their sensitivity to alcohol was altered compared with those who had not been exposed.

This implies that if a mother drinks even a small amount during pregnancy, there is a greater chance that her children and grandchildren will become alcoholic.

Cameron told Medical News Today:

“Alcohol is a dirty drug that may affect multiple systems. We have selected this period of exposure because, in rats, many important developments take place at that time including dopaminergic axons from the midbrain reaching the cortical plate and the development of GABAergic neurons in cortical layer IV. Since the cortex plays a principal role in mediating ethanol-induced effects, these two events are particularly important in the study of alcohol sensitivity and abuse.”

Other studies into the effects of alcohol exposure during pregnancy have focused on fetuses that were directly exposed or on cellular activity over multiple generations, but they have not looked at alcohol-related behaviors over the second or third generation.

The next step will be to identify how this effect passes through the generations by looking at the effects of alcohol on the genome and epigenome, which are the molecules that control gene translation.

MNT reported recently that the very first drink a person experiences will cause a neurological change in the brain.

When we asked Cameron whether she would expect the same effect to manifest more strongly in someone who was exposed during pregnancy, she replied: “Yes, because the brain is developing, I expect the effect to be more potent in the fetus.”

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Source: medicalnewstoday

27 Feb

Medical News Today: Antisense drug for Huntington's looks promising

A drug that could target the cause of Huntington’s disease has been safely and effectively tested in mice and monkeys, and human trials will follow. The progress is due to be presented at the 68th Annual Meeting of the American Academy of Neurology.
[man in wheelchair]
Huntington’s disease is a debilitating condition that affects motor, cognitive and emotional function.

Huntington’s disease (HD) is a rare, hereditary condition that causes uncontrolled movements, cognitive and emotional difficulties and, eventually, death.

HD passes from parent to child through a mutation in the huntingtin gene (HTT mRNA). This mutation leads to the production of a huntingtin (Htt) protein, and this causes the disease.

A child whose parent has the mutated gene will have a 50% chance of inheriting the mutation. Everyone who has it will eventually develop the disease.

While tetrabenazine was approved by the Food and Drug Administration (FDA) in 2008 to treat Huntington’s chorea, the involuntary writhing movements that are symptomatic of the disease, there is so far no way of curing or preventing HD.

Antisense drug IONIS-HTTRx delays onset and reverses symptoms

IONIS-HTTRx is an antisense drug that inhibits the production of the huntingtin protein by “silencing” the gene.

Studies so far have indicated that antisense drugs can help to delay progression of the disease and can reverse the disease phenotype.

In one mouse model, motor deficits improved within a month of beginning the treatment, and, 2 months after treatment termination, they were restored to normal.

Another mouse study indicated an improvement 8 weeks after starting treatment, and this continued for at least 9 months after stopping the treatment.

In monkeys, an antisense drug caused reductions in the huntingtin gene and protein throughout the central nervous system, at levels that depended on the dose.

A 50% reduction of cortical huntingtin levels was observed in monkeys, correlating with 15-20% reduction in the caudate nucleus of the brain. The caudate nucleus is located in the basal ganglia, which plays a key role in sensorimotor coordination.

Further tests in mice and monkeys suggest that IONIS-HTTRx is well tolerated, with no dose-limiting side effects. 

Next step: phase 1/2a clinical study

The next step is to trial the drug in humans. A phase 1/2a clinical study is now under way.

The drug is administered in four doses at monthly intervals. As antisense drugs do not cross the blood-brain barrier, IONIS-HTTRx is injected into the cerebral spinal fluid via an intrathecal injection in the lumbar space.

The researchers will evaluate the safety and tolerability of the drug at different doses. They will also characterize the drug pharmacokinetics and examine the effects of the therapy on specific biomarkers and clinical outcomes. 

Clinical study principal investigator Dr. Blair R. Leavitt, of the University of British Columbia in Vancouver, Canada, says:

“It is very exciting to have the possibility of a treatment that could alter the course of this devastating disease. Right now we only have treatments that work on the symptoms of the disease.”

However, Dr. Leavitt notes that it will still be several years before the drug will be ready for use in human clinical practice.

Medical News Today reported last year that a new understanding of the effect of HD on DNA could lead to future breakthroughs in the search for a cure.

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Source: medicalnewstoday

27 Feb

Medical News Today: Dried plums could protect against radiation-induced bone loss

Eating dried plums may protect against bone loss caused by ionizing radiation, claims a new study published in the journal Scientific Reports.
[Dried plums]
Dried plums could protect against bone loss caused by ionizing radiation, according to new research.

Study coauthor Dr. Nancy Turner, of the Department of Nutrition and Food Science at Texas A&M University, and colleagues say their findings may have important implications for individuals heavily exposed to ionizing radiation.

These include cancer patients undergoing radiotherapy, astronauts, radiation workers and victims of nuclear accidents.

“Bone loss caused by ionizing radiation is a potential health concern for those in occupations or in situations that expose them to radiation,” Dr. Turner explains.

“The changes in remodeling activity caused by exposure to radiation can lead to impaired skeletal integrity and fragility both in animals and human radiotherapy patients.”

In humans, bone loss can lead to osteoporosis – a disease in which the bones become more brittle, fragile and more vulnerable to breakage. It is estimated that osteoporosis is responsible for more than 8.9 million fractures worldwide each year.

For the study, the researchers set out to investigate a number of strategies that they believed could tackle the underlying mechanisms that contribute to ionizing radiation-related bone damage, such as radiation-induced oxidative stress.

Dried plums reduced gene expression linked to bone breakdown

The team tested a number of different antioxidant and anti-inflammatory interventions on mice that were exposed to ionizing radiation, assessing the effects the interventions had on the expression of genes linked to the breakdown of bone, as well as their effects on bone loss.

The interventions included a cocktail consisting of five different antioxidants (ascorbic acid, N-acetyl cysteine, L-selenomethionine, dihydrolipoic acid and vitamin E), dihydrolipoic acid, ibuprofen and dried plum.

The team found that dried plum was most effective for reducing expression of the genes Nfe2l2, Rankl, Mcp1, Opg and TNF-α, which are related to the breakdown of bone. Dried plum was also most effective for preventing later bone loss induced by ionizing radiation.

While the researchers are unable to explain the exact reasons why dried plums appear to protect bones from damage caused by ionizing radiation, they note that the fruit contains a number of polyphenols – including gallic acid, caffeoyl-quinic acids, coumaric acid and rutin – that have antioxidant and anti-inflammatory properties.

“Dried plums contain biologically active components that may provide effective interventions for loss of structural integrity caused by radiotherapy or unavoidable exposure to space radiation incurred over long-duration spaceflight,” says Dr. Turner, adding:

“From this study, we can conclude that inclusion of dried plums in the diet may prevent the skeletal effects of radiation exposures either in space or here on Earth.”

Last year, Medical News Today reported on another study from Dr. Turner and colleagues that suggested eating dried plums may help lower the risk of colon cancer.

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Source: medicalnewstoday

27 Feb

Gene Abnormality May Be Key to Down Syndrome, Scientists Say

Gene Abnormality May Be Key to Down Syndrome, Scientists Say

News Picture: Gene Abnormality May Be Key to Down Syndrome, Scientists Say

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THURSDAY, Feb. 25, 2016 (HealthDay News) — Researchers say they’ve discovered a genetic abnormality that affects brain development in people with Down Syndrome, and they say this finding might lead to new treatments.

“This discovery of the genetic changes that alter communication within the brain uncovered a completely new target for therapies in the brains of people with [Down syndrome],” study co-leader Tarik Haydar, associate professor of anatomy and neurobiology at Boston University School of Medicine, said in a university news release.

His research team compared the activity of genes in different areas of the brain in people with Down syndrome as they grew from infants to adults.

They found that the development of white matter — which insulates of brain nerve fibers — changes as people with Down syndrome move from childhood to adulthood.

These changes are due to specific development defects in brain cells that form white matter, and result in slower nerve transmission, the researchers said.

The researchers said the finding was unexpected, given that the standard theory is that changes leading to intellectual disability all happen before birth in Down syndrome.

“These findings may allow researchers to design strategies to promote brain functioning and improve quality of life,” Haydar added.

The results may also prove important for other development disabilities, such as autism, according to the researchers.

Down syndrome, the most common genetic cause of intellectual disability, occurs in about one in every 691 live births. The disorder affects about 400,000 Americans, researchers said.

The study will be published in the March 16 issue of the journal Neuron.

— Robert Preidt

MedicalNews
Copyright © 2016 HealthDay. All rights reserved.

SOURCE: Boston University School of Medicine, news release, Feb. 25, 2016

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Source: MediciNet