Tag: 29/3/21

Categories : ExerciseTags :

Intense Exercise Needed to Prevent Heart Changes in Space

On By ModernMedia

A study of an astronaut and an extreme long distance swimmer has shown that intense exercise is needed to prevent heart changes in space or situations of reduced weight, such as water immersion.

By comparing data from astronaut Scott Kelly’s year in space aboard the International Space Station and comparing it to information from Benoît Lecomte’s  extreme long distance swimming, which simulates weightlessness, researchers found that low-intensity exercise was not enough to counteract the effects of prolonged weightlessness on the heart.

In a sitting or standing position, gravity draws blood into the lower extremities, and removing this effect through water immersion, prolonged bed rest or zero gravity conditions causes the heart to shrink as it no longer has to pump against this effect. Researchers have used the lack of gravity in space to investigate the physiology of ageing and muscle and bone loss, and vice versa.

Researchers examined data from retired astronaut Scott Kelly’s year-long mission aboard the ISS from 2015 to 2016 and elite endurance swimmer Benoît Lecomte’s swim across the Pacific Ocean in 2018.

In this new study, researchers evaluated the effects of long-term weightlessness on the structure of the heart and to help understand whether extensive periods of low-intensity exercise can prevent the effects of weightlessness.

“The heart is remarkably plastic and especially responsive to gravity or its absence. Both the impact of gravity as well as the adaptive response to exercise play a role, and we were surprised that even extremely long periods of low-intensity exercise did not keep the heart muscle from shrinking,” said senior author Benjamin D Levine, MD, and a professor of internal medicine at UT Southwestern Medical Center and director of Texas Health Presbyterian’s Institute for Exercise and Environmental Medicine.

The research team examined medical data from Kelly’s year aboard the ISS and Lecomte’s swim across the Pacific Ocean to investigate the impact of long-term weightlessness on the heart. Water immersion is an excellent model for weightlessness since water offsets gravity’s effects, especially in the prone swimming technique used by long-distance endurance swimmers.

As part of the routine countermeasures to maintain physical fitness in space, Kelly exercised six days a week, one to two hours per day using a stationary bike, a treadmill and resistance activities. Researchers hoped Lecomte’s 159-day 2700km swim from Choshi, Japan, with almost six hours a day of swimming, would keep his heart from shrinking and weakening. Doctors performed various tests to measure the health and effectiveness of both Kelly’s and Lecomte’s hearts before, during and after each man embarked on his respective expeditions.

Both men and Lecomte lost mass from their left ventricles (Kelly 0.74 grams/week; Lecomte 0.72 grams/week). They also suffered an initial shrinkage in the diastolic diameter of their heart’s left ventricle (Kelly’s dropped from 5.3 to 4.6cm; 5 to 4.7cm for Lecomte).

Even the most sustained periods of low-intensity exercise were not enough to counteract the effects of prolonged weightlessness. Left ventricle ejection fraction (LVEF) and markers of diastolic function did not consistently change in either individual throughout their campaign.

Due to its exceptional nature, more study is required to understand how these results can be applied to the general population. 

Lecomte had cardiac MRIs from before and after his swim and analysis of these is forthcoming. These will be helpful for the researchers to further understand whether long-term effects of weightlessness are reversible. Kelly did not receive cardiac MRIs, and currently, there are no further follow up plans for him.

Source: Medical Xpress

Journal information: Circulation (2021). DOI: 10.1161/CIRCULATIONAHA.120.050418

Categories : Neurodegenerative DiseasesTags :

Green Light for New Device for MS Treatment

On By ModernMedia

The American Food & Drug Administration has approved a new device for treating gait deficits in multiple sclerosis (MS) patients.

The Portable Neuromodulation Stimulator (PoNS), generates electrical pulses on the tongue to stimulate trigeminal and facial nerves to treat motor deficits. The FDA said that for it to be available by prescription, must be part of a supervised therapeutic exercise program in MS patients 22 and older. The device was authorised through the FDA’s ‘de novo’ premarket review pathway for new devices which pose do not pose significant risks of adverse effects.

In a statement, Christopher Loftus, MD, acting director of the Office of Neurological and Physical Medicine Devices in the FDA’s Center for Devices and Radiological Health, said: “MS is one of the most common neurological diseases in young adults. Today’s authorisation offers a valuable new aid in physical therapy and increases the value of additional therapies for those who live with MS on a daily basis.”

Onset of MS symptoms, which can include difficulties with walking and balance, typically occurs between 20 and 40, with greater frequency in women.

The PoNS device electrical stimulates the dorsal surface of the patient’s tongue. A control unit is worn around the neck which sends signals to a mouthpiece which the patient keeps in place with lips and teeth. Later, usage data can be viewed by a therapist to spot “potential areas of missed or shortened sessions,” the FDA noted.

The FDA gave their approval based on two clinical studies. One involved 20 MS patients with gait deficits (half with PoNS; half with a sham device). Th FDA said that the PoNS group showed “statistically significant and clinically significant” improvement in Dynamic Gait Index (DGI) scores at 14 weeks not seen in the sham device group.

The other study, with 14 patients, showed improvements from baseline in sensory organisation task scores (but not in DGI scores) at 14 weeks. There were no serious safety or adverse effects reported.

Among the FDA’s cautions, the FDA stated that the PoNS device should not be used by patients with penetrating brain injuries, neurodegenerative diseases, oral health problems, chronic infectious diseases, unmanaged hypertension or diabetes, pacemakers, or a history of seizures.

Source: MedPage Today

Categories : New Compounds and TreatmentsTags :

Antibodies May Hold The Key to Tooth Regeneration

On By ModernMedia

It may be possible to regenerate missing teeth using monoclonal antibodies, according to a new study by scientists at Kyoto University and the University of Fukui. 

The team reported that an antibody for one gene—uterine sensitisation associated gene-1 or USAG-1—can stimulate tooth growth in mice suffering from tooth agenesis, a congenital condition. The paper was published in Science Advances. Monoclonal antibodies are often used to treat cancers, arthritis, and vaccine development.

Although the normal adult mouth has 32 teeth, about 1% of the population has more or fewer due to congenital conditions; adults with too many teeth are of interest because they could hold genetic clues to tooth regeneration.

Katsu Takahashi, one of the lead authors of the study and a senior lecturer at the Kyoto University Graduate School of Medicine, said that the fundamental molecules responsible for tooth development have already been identified.

“The morphogenesis of individual teeth depends on the interactions of several molecules including BMP, or bone morphogenetic protein, and Wnt signaling,” said Takahashi.

BMP and Wnt are also involved in the development of organs when humans are mere embryos. This means that drugs directly affecting their activity are usually avoided, as side effects could impact the entire body. The team considered the gene USAG-1, as they guessed that it could be safer to target the factors that antagonise BMP and Wnt specifically in tooth development .

“We knew that suppressing USAG-1 benefits tooth growth. What we did not know was whether it would be enough,” added Takahashi.

The scientists therefore investigated the effects of several monoclonal antibodies for USAG-1. Since USAG-1 interacts with both BMP and Wnt, many of the antibodies resulted in poor birth and survival rates of mice, showing that BMP and Wnt are important for whole body growth. However one antibody managed to disrupt the interaction of USAG-1 with BMP only.

Experimentation showed that BMP signalling is necessary for the number of teeth in mice, and a single administration was enough to generate an entire tooth. The same effects were seen in ferrets.

“Ferrets are diphyodont animals with similar dental patterns to humans. Our next plan is to test the antibodies on other animals such as pigs and dogs,” explains Takahashi.

This is the first study to show the benefits of monoclonal antibodies on tooth regeneration, and offers new alternatives to implants.

“Conventional tissue engineering is not suitable for tooth regeneration. Our study shows that cell-free molecular therapy is effective for a wide range of congenital tooth agenesis,” concluded Manabu Sugai of the University of Fukui, another author of the study.

Source: Medical Xpress

Journal information: A. Murashima-Suginami et al, Anti–USAG-1 therapy for tooth regeneration through enhanced BMP signaling, Science Advances (2021). DOI: 10.1126/sciadv.abf1798

Categories : Gender Injury & TraumaTags :

Social Plus Biological Factors Increase Knee Injuries Among Female Athletes

On By ModernMedia

Writing in the British Medical Journal, scientists have argued that the study of knee injuries in female athletes is too focused on biological factors and not enough on social factors.

It is said that female athletes experience anterior cruciate ligament (ACL) injury, at a rate three to six times higher than their male counterparts.The ACL is one of the key ligaments that helps to stabilise the knee joint. This can be a career-ending injury, and occurs most often in sports involving sudden changes of direction such as basketball.

The authors of the paper argued that much of the focus still falls on biological and hormonal factors, with little attention paid to how sex-based factors are affected by the social concept of gender and how they could influence each other.

They suggested that gendered experiences are relevant in shaping female sport participation as well as disparities in injury outcomes. They demonstrated that, over a lifetime, gendered expectations of physical abilities (eg ‘throw like a girl’), to inequitable access to funding, training, and facilities for women’s sport (eg disparities in access to weight training).

Lastly, the authors suggested there may also be differences between post-injury rehabilitation for men and women recovering from an ACL injury. These social and environmental factors play a much bigger role in how sports injuries occur than once thought, they said, urging that there should be much more weight given to these issues.

Dr Sheree Bekker from the Department for Health at the University of Bath (UK) explained: “We wanted to unpack the biases and assumptions that we were seeing in research into and practice around sports injuries in girls and women. Specifically, we wanted to challenge the increasingly pervasive idea that this is simply a problem for girls/women because they are inherently prone to injury just because of their female biology. Approaching ACL injury prevention and management from a strictly biological view can propagate sexism in sport with detrimental consequences for girls and women.”

Dr Joanne Parsons from the University of Manitoba (Canada) added: “Over 20 years of research focussed on biological traits has failed to decrease the ACL injury rate in girls and women. To make a difference, we need to approach the problem in a different way. The recent challenges that the NCAA women’s teams faced with access to adequate training equipment is a perfect example of why we have to include society’s influence when talking about injury risk for girls/women.”

Paper co-author Dr Stephanie Coen of the University of Nottingham said: “By extending the focus from individual bodies and biology to the gendered environments contextualizing ACL injury, our approach identifies new opportunities to intervene and achieve better outcomes for girls and women, with implications beyond athletes. As childhood and youth physical activity levels influence those in adulthood, the sequelae of ACL injury can be lifelong and particularly concerning for girls and women who already participate in physical activity at lower rates than boys and men. There is a wider health equity issue at stake.”

Source: Medical Xpress

Journal information: Joanne L Parsons et al, Anterior cruciate ligament injury: towards a gendered environmental approach, British Journal of Sports Medicine (2021). DOI: 10.1136/bjsports-2020-103173

Categories : COVID General InterestTags :

Pandemic Steals the Enjoyment of Terminally Ill Patients’ Last Years

On By ModernMedia

Welsh grandmother Maggie Shaftoe has a terminal brain tumour and doctors have told her she has less than two years to live.

Life with a terminal illness during the coronavirus pandemic and being in lockdown has caused difficulties for one couple making final memories.

Macmillan Cancer Support calls it an “acutely challenging time” for people living with a terminal diagnosis.

In 2017, the 63-year-old great-grandmother was diagnosed with an Anaplastic Pleomorphic Xanthoastrocytoma (APXA) brain tumour, which is very rare and most commonly occurs in children and young people with an average age for diagnosis at 12 years old. Her cancer was discovered by chance through a regular epilepsy check up and an MRI scan.

Mrs Shaftoe said that she has not seen her 11 grandchildren and great-granddaughter and she’s “just waiting for things to get back to normal”.

Together for more than 50 years, Mrs Shaftoe and her husband Chris first met as teenagers in a church choir in London. Mr Shaftoe said at this stage they “should be making the most of the time she has left and making memories with our family”.

“I think we’d like to go somewhere like Disneyland, or Lapland to see the northern lights or she’d love to go to the Cheddar Gorge,” said Mr Shaftoe, 65.

“But the pandemic has buried us in a great big hole and I don’t expect the situation to change.

“We’re noticing that Maggie’s memory is fading quite quickly now and she is getting worse day by day, and we understand what is coming,” he said.

In 2017 Mrs Shaftoe had an operation to remove the tumour and the following year had radiotherapy.

But Mr Shaftoe said this has only “delayed the inevitable” and his wife’s life expectancy “hangs on the effectiveness” of two anti-cancer drugs.

Since the operation, she has suffered difficulty with her memory, impaired speech, balance problems and is partially blind.

Doctors have told the couple that typically life expectancy for a patient with APXA would be five years.

Cancer Research UK said that the pandemic has had a “devastating impact on the lives of cancer patients”.

“Dealing with a cancer diagnosis and treatment is extremely difficult at any time, but the pandemic has added the stress of uncertainty, delays and shielding for some cancer patients,” said Martin Ledwick,  head information nurse at the charity.

Mrs Shaftoe remains positive despite the situation, saying it helps to laugh.

“If you can make a joke of something, make a joke of it,” she said, speaking during Brain Tumour Awareness month.

“You go out to make a cup of tea and you end up peeling potatoes, and come back in and wonder why I haven’t got a cup of tea – you have to laugh at silly little things.”

However managing during lockdown has been “very difficult” and mundane tasks could be a “major headache”, according to her husband, who has medical conditions of his own.

Mr Shaftoe says they now have a carer who comes for an hour each morning.

But he said: “We need more care. We have spent most of the pandemic without a carer and it has been absolutely nightmarish trying to get Maggie one.”

Macmillan Cancer Support in Wales said it has heard from many people in isolation, which makes “a challenging situation even more difficult”.

“We know this is an acutely challenging time for people with cancer, the NHS and cancer care, and particularly for people who are living with a terminal diagnosis,” said Richard Pugh, Macmillan’s head of partnerships.

Source: BBC News

Categories : Diseases, Syndromes and ConditionsTags :

Premature Death Risk Doubled for Patients With Superbug on Their Skin

On By ModernMedia

Adults middle-aged or older who carry methicillin-resistant Staphylococcus aureus (MRSA) ‘superbug’ on their skin are twice as likely to die within the next decade as people who do not, according to a study by the University of Florida (UF).

“Very few people who carry MRSA know they have it, yet we have found a distinct link between people with undetected MRSA and premature death,” said lead author Arch Mainous, PhD, a professor in the department of health services research, management and policy at UF.

The findings suggest that routine screening for undetected MRSA may be warranted in older people to prevent deaths from infection.

A third of Americans carry Staphylococcus aureus, or staph, on their skin or in nasal passages, and of these about 1% carry MRSA, the notorious antibiotic resistant staph strain.

MRSA carriers may not even be aware that they carry the bacteria unless they develop an infection or are tested for it. A quarter of people who carry MRSA without an active infection, known as colonised MRSA for at least a year, eventually develop a MRSA infection.

“MRSA can be part of normal body flora, but it can lead to infection when immune systems are compromised, especially in people who are hospitalized, have underlying disease, or after antibiotic use,” said Prof Mainous, also vice chair for research in the UF College of Medicine’s department of community health and family medicine.

According to a 2017 Centers for Disease Control and Prevention report, 119 000 Americans experienced a staph bloodstream infection and nearly 20 000 died. Hospitalised patients with colonised MRSA may be particularly vulnerable to  infection in hospital or after discharge. Among carriers, wounds, surgical incisions and use of medical devices, such as catheters, may also lead to MRSA infection.

In this study, researchers analysed data from the 2001-2004 National Health and Nutrition Examination Survey, a nationally representative study combining survey questions with laboratory testing, which includes nasal swabs for detecting MRSA.

Adjusting for risk factors including gender and ethnicity, the researchers linked data on participants ages 40-85 with data from the National Death Index to track deaths over an 11-year period.

The mortality rate among participants without MRSA was about 18% compared with 36% among those with colonised MRSA. There was no increased mortality risk for those with non-MRSA staph bacteria on their skin.

Although some states and hospital systems require MRSA testing for patients before hospital admission, policies for testing and treatment of colonised MRSA, which may include antibiotics use, vary widely betweens hospitals, Prof Mainous said.

“Without a uniform strategy, we are missing an opportunity to help prevent deaths caused by MRSA,” he said. “Maybe we should know who is carrying MRSA.”

Source: Medical-News.Net

Journal information: Mainous, A. G., et al. (2021) Methicillin-Resistant Staphylococcus Aureus Colonization and Mortality Risk Among Community Adults Aged 40-85. Journal of the American Board of Family Medicine.