Public Health

loss of motivation and Alzheimers disease progression - افسردگی مقدم بر آلزایمر

Researchers from Indiana University School of Medicine are studying why neuropsychiatric symptoms, such as apathy and irritability, appear in most Alzheimer’s disease patients before the onset of memory loss.

The study, led by Yao-Ying Ma, MD, PhD, assistant professor of pharmacology and toxicology, was recently featured in the publication Molecular Psychiatry.

The investigation focused on the nucleus accumbens, a critical brain region processing motivation. Located in the ventral striatum, this region is not studied much among Alzheimer’s disease researchers, Ma said; it’s mainly researched to understand motivational and emotional processes. Previous studies, Ma said, have shown that the volume of nucleus accumbens, like the cortical and hippocampal regions in the brain, is reduced in adults with Alzheimer’s disease.

Ma, who is relatively new to the field of Alzheimer’s disease research, has a background in drug addiction studies and synaptic communication—the process by which neurons talk to each other in the brain. Some of the neuropsychiatric symptoms among people who suffer from substance abuse—apathy, mood swings, anxiety—are also found in Alzheimer’s disease patients.

The investigation focused on the nucleus accumbens, a critical brain region processing motivation. Located in the ventral striatum, this region is not studied much among Alzheimer’s disease researchers, Ma said; it’s mainly researched to understand motivational and emotional processes. Previous studies, Ma said, have shown that the volume of nucleus accumbens, like the cortical and hippocampal regions in the brain, is reduced in adults with Alzheimer’s disease.

Ma, who is relatively new to the field of Alzheimer’s disease research, has a background in drug addiction studies and synaptic communication—the process by which neurons talk to each other in the brain. Some of the neuropsychiatric symptoms among people who suffer from substance abuse—apathy, mood swings, anxiety—are also found in Alzheimer’s disease patients.

These neuropsychiatric symptoms, however, tend to occur earlier than memory loss, but no effective treatments are available, Ma said. She emphasized that there is an urgent need to understand why those symptoms exist and how they correlate with cognitive deficits. Ma said this study identified synaptic calcium permeable receptors (CP-AMPARs) in the nucleus accumbens in an Alzheimer’s disease model. The receptor, which is normally absent in that part of the brain, gives permission for calcium to enter the neurons. This leads to an overload of calcium, which leads to a breakdown of its synaptic structure. In turn, calcium accumulation triggers a cascade of intracellular changes that can be lethal to the neuron by amplifying calcium overload via a positive feedback mechanism.

Release date: 25 April 2022
Source: Indiana University School of Medicine

Women may be less likely to go back to work after severe stroke - سکته مغزی و اشتغال

More than one-third of people who have a clot removed from a major blood vessel in the brain after a stroke return to work within three months, according to a new study from Germany. But women were half as likely to do so as men.

The study, published Thursday in the American Heart Association journal Stroke, found women and men were more likely to return to work if they were treated with a combination of mechanical blood clot removal and clot-busting medication to clear their clogged blood vessels than if they just had their clots removed.

When blood clots in the brain block a major artery, they can cause a severe stroke with the potential for serious disability, making it less likely people will return to work. Clot-caused ischemic strokes account for 87% of all strokes in the U.S. Blockages in large vessels account for 24%-46% of ischemic strokes. Stroke is the fifth-leading cause of death in the U.S. and a leading cause of disability.

Endovascular mechanical thrombectomy is a procedure that uses a slim catheter to remove a clot blocking a large blood vessel in the brain. This procedure, along with clot-busting medications, is considered standard practice for the treatment of some severe strokes.

Researchers analyzed data for 606 men and women, ages 18 to 64, in Germany who survived large vessel occlusion ischemic strokes between 2015 and 2019. Participants, all of whom worked prior to their strokes, were treated with a mechanical thrombectomy. A subset of 370 patients also received clot-busting medications. They compared those who went back to work 90 days after having a thrombectomy to those who did not return to work.

Release date: 21 April 2022
Source: American Heart Association

COVID-19 Pneumonia Increases Dementia Risk - دمانس کرونایی

A new study from the from the University of Missouri School of Medicine and MU Health Care shows patients hospitalized with COVID-19 pneumonia have a higher risk of developing dementia than those with other types of pneumonia.

A team of MU researchers pulled Cerner Real World Data from 1.4 billion medical encounters prior to July 31, 2021. They selected patients hospitalized with pneumonia for more than 24 hours. Among 10,403 patients with COVID-19 pneumonia, 312 (3%) developed new onset dementia after recovering, compared to 263 (2.5%) of the 10,403 patients with other types of pneumonia diagnosed with dementia.

Their study, “New Onset Dementia Among Survivors of Pneumonia Associated with Sevre Acute Respiratory Syndrome Coronavirus 2 Infection,” was recently published in the journal Open Forum Infectious Diseases. Part of the support for this study was provided by the National Institutes of Health. The content does not necessarily represent the official views of the funding agency. Qureshi has received consultation fees from AstraZeneca. The authors declare no other potential conflicts of interest.

Release date: 19 April 2022
Source: University of Missouri-Columbia

Intense exercise while dieting may reduce cravings for fatty food - ورزش و اشتها

In a study that offers hope for human dieters, rats on a 30-day diet who exercised intensely resisted cues for favored, high-fat food pellets.

The experiment was designed to test resistance to the phenomenon known as “incubation of craving,” meaning the longer a desired substance is denied, the harder it is to ignore signals for it. The findings suggest that exercise modulated how hard the rats were willing to work for cues associated with the pellets, reflecting how much they craved them.

While more research needs to be done, the study may indicate that exercise can shore up restraint when it comes to certain foods, said Travis Brown, a Washington State University physiology and neuroscience researcher.

“A really important part of maintaining a diet is to have some brain power—the ability to say ‘no, I may be craving that, but I’m going to abstain,’” said Brown, corresponding author on the study published in the journal Obesity. “Exercise could not only be beneficial physically for weight loss but also mentally to gain control over cravings for unhealthy foods.”

In the experiment, Brown and colleagues from WSU and University of Wyoming put 28 rats through a training with a lever that when pressed, turned on a light and made a tone before dispensing a high-fat pellet. After the training period, they tested to see how many times the rats would press the lever just to get the light and tone cue.

Release date: 21 April 2022
Source: Washington State University

Antidepressants are not associated with improved quality of life in the long run - داروهای ضدافسردگی واقعا موثرند

Among people with depression, those using antidepressants over the long term had no better physical or mental health. Over time, using antidepressants is not associated with significantly better health-related quality of life, compared to people with depression who do not take the drugs. These are the findings of a new study published this week in the open-access journal PLOS ONE by Omar Almohammed of King Saud University, Saudi Arabia, and colleagues.

It is generally well known that depression disorder has a significant impact on the health-related quality of life (HRQoL) of patients. While studies have shown the efficacy of antidepressant medications for treatment of depression disorder, these medications’ effect on patients’ overall well-being and HRQoL remains controversial.

In the new study, the researchers used data from the 2005-2015 United States’ Medical Expenditures Panel Survey (MEPS), a large longitudinal study that tracks the health services that Americans use. Any person with a diagnosis of depression disorder was identified in the MEPS files. Over the duration of the study, on average there were 17.47 million adult patients diagnosed with depression each year with two years of follow-up, and 57.6% of these received treatment with antidepressant medications.

Release date: 20 April 2022
Source: EurekAlert

Brisk walking may slow biological ageing process - ورزش کاهنده سرعت ساعت بیولوژیک

A new study of genetic data published today (Wednesday) of more than 400,000 UK adults has revealed a clear link between walking pace and a genetic marker of biological age.

Confirming a causal link between walking pace and leucocyte telomere length (LTL) – an indicator of biological age – the Leicester-based team of researchers estimate that a lifetime of brisk walking could lead to the equivalent of 16 years younger biological age by midlife.

Researchers from the University of Leicester at the National Institute for Health and Care Research (NIHR) Leicester Biomedical Research Centre studied genetic data from 405,981 middle-aged UK Biobank participants and found that a faster walking pace, independent of the amount of physical activity, was associated with longer telomere.

Telomeres are the ‘caps’ at the end of each chromosome, and hold repetitive sequences of non-coding DNA that protect the chromosome from damage, similar to the way the cap at the end of a shoelace stops it from unravelling.

Each time a cell divides, these telomeres become shorter – until a point where they become so short that the cell can no longer divide, known as ‘replicative senescence’. Therefore, scientists consider LTL a strong marker for ‘biological age’, independent from when an individual was born.

Release date: 20 April 2022
Source: University of Leicester

Air pollution linked to higher risk of COVID19 in young adults - افزایش خطر کووید19 در شرایط آلودگی هوا

Residential exposure to ambient air pollutants is linked to an elevated risk of SARS-CoV-2 infection, an observational study of young adults in Stockholm, Sweden shows. The study was conducted by researchers from Karolinska Institutet and is published in JAMA Network Open.

Since pollutants in outdoor air can increase the risk of respiratory infections such as influenza and SARS, the COVID-19 pandemic aroused fears that they could also contribute to the risk of SARS-CoV-2 infection. Studies have also shown that areas of poor air quality have more cases of COVID-19.

Researchers at Karolinska Institutet have now studied this more closely by examining the link between estimated exposure to air pollutants at home addresses and positive PCR tests for SARS-CoV-2 in young adults in Stockholm, Sweden.

Release date: 20 April 2022
Source: Karolinska Institutet

stem cell can help low back pain and spinal issues - درمان کمردرد با کمک سلول های بنیادی

Researchers from Osaka University and Kyoto University develop a stem cell-based biomaterial that can help regenerate tissue associated with low back pain and spinal issues.

Many people have experienced the struggles of dealing with low back pain. A common cause of this pain is degeneration of intervertebral disks (IVDs), which are located between the vertebrae and help give the spinal column its flexibility. Thus, IVD degeneration can lead to more serious conditions such as spinal deformity. In a recent article published in Biomaterials, a team led by researchers at Osaka University and Kyoto University demonstrated that using cartilage tissue derived from human stem cells could help prevent the loss of functionality from IVD degeneration.

The article, “Human iPS cell-derived cartilaginous tissue spatially and functionally replaces nucleus pulposus,” was published in Biomaterials.

Release date: 15 April 2022
Source: Osaka University

Exercise During Pregnancy Reduces the Risk of Type-2 Diabetes in Offspring - ورزش مادر کاهش خطر دیابت در فرزند

A new study has demonstrated that maternal exercise during pregnancy improves the metabolic health of offspring, even when the mother is obese or on a high-fat diet. Physical exercise by the mother induces the placenta to secrete the key protein SOD3, resulting in a lowered risk of diabetes for the offspring. The findings in the paper identified the mechanisms behind this process.

The results were published in the Journal Diabetes.

Release date: 14 April 2022
Source: Tohoku University

Recalled Experiences Surrounding Death More Than Hallucinations - تجربیات نزدیک مرگ فراتر از توهم

Scientific advances in the 20th and 21st centuries have led to a major evolution in the understanding of death. At the same time, for decades, people who have survived an encounter with death have recalled unexplained lucid episodes involving heightened consciousness and awareness. These have been reported using the popular—yet scientifically ill-defined—term “near-death experiences.”

The researchers on the study represent many medical disciplines, including the neurosciences, critical care, psychiatry, psychology, social sciences, and humanities, and represent many of the world’s most respected academic institutions including Harvard University, Baylor University, the University of California, Riverside, the University of Virginia, Virginia Commonwealth University, the Medical College of Wisconsin, the University Hospital Southampton, and King’s College, London.

Among their conclusions are the following:

  • Due to advances in resuscitation and critical care medicine, many people have survived encounters with death or being near-death. These people—who are estimated to comprise hundreds of millions of people around the world based on previous population studies—have consistently described recalled experiences surrounding death, which involve a unique set of mental recollections with universal themes.
  • The recalled experiences surrounding death are not consistent with hallucinations, illusions, or psychedelic drug–induced experiences, according to several previously published studies. Instead, they follow a specific narrative arc involving a perception of (a) separation from the body with a heightened, vast sense of consciousness and recognition of death; (b) travel to a destination; (c) a meaningful and purposeful review of life, involving a critical analysis of all actions, intentions, and thoughts towards others; a perception of (d) being in a place that feels like “home”; and (e) a return back to life.
  • The experience of death culminates into previously unidentified, separate subthemes and is associated with positive long-term psychological transformation and growth.
  • Studies showing the emergence of gamma activity and electrical spikes—ordinarily a sign of heightened states of consciousness on electroencephalography (EEG)—in relation to death further support the claims of millions of people who have reported experiencing lucidity and heightened consciousness in relation to death.
  • Frightening or distressing experiences in relation to death often neither share the same themes, nor the same narrative, transcendent qualities, ineffability, and positive transformative effects.

Release date: 12 April 2022
Source: NYU Grossman School of Medicine