Day: April 14, 2021

Categories : Cardiovascular DiseaseTags :

Study Upends Preconceptions of Blood Pressure Management

On By ModernMedia

New research could change how doctors treat some patients with hypertension, as they find that low diastolic blood pressure can be benign in blood pressure management.

The study by researchers at NUI Galway, Johns Hopkins University and Harvard Medical School found no evidence that diastolic blood pressure can be harmful to patients when reduced to levels that were previously considered to be too low. High blood pressure, or hypertension, affects a quarter of men and a fifth of women. Blood pressure medications reduce both systolic and diastolic values.

Lead researcher Bill McEvoy, Professor of Preventive Cardiology at NUI Galway and a Consultant Cardiologist at University Hospital Galway, said the findings have the potential to immediately influence the clinical care of patients. The study was published in the prestigious journal Circulation.

“We now have detailed research based on genetics that provides doctors with much-needed clarity on how to treat patients who have a pattern of high systolic values – the top reading for blood pressure – but low values for the diastolic, or bottom, reading,” said Bill McEvoy, Professor of Preventive Cardiology at NUI Galway. “This type of blood pressure pattern is often seen in older adults. Old studies using less reliable research methods suggested that the risk for a heart attack began to increase when diastolic blood pressure was below 70 or above 90. Therefore, it was presumed there was a sweet-spot for the diastolic reading.”

Hypertension is a major contributor to mortality around the world, linked to heart attacks as well as brain, kidney and other diseases. It has also emerged as a risk factor for COVID severity and mortality.

Using new technologies that take into account genetic information that is unbiased, which was not the case with prior observational studies, Professor McEvoy and the international research team analysed genetic and survival data from more than 47 000 patients worldwide.

The researchers found that there is apparently no lower limit of normal for diastolic blood pressure and no evidence in this genetic analysis that diastolic blood pressure can be too low. They also found no genetic evidence of increased risk of heart disease when a patient’s diastolic blood pressure reading is as low as 50. The findings confirmed that values of the top, systolic, blood pressure reading above 120 increased the risk of heart disease and stroke. 

“Because doctors often focus on keeping the bottom blood pressure reading in the 70-90 range, they may have been undertreating some adults with persistently high systolic blood pressure,” Prof McEvoy explained. “The findings of this study free up doctors to treat the systolic value when it is elevated and to not worry about the diastolic blood pressure falling too low.

“My advice now to GPs is to treat their patients with high blood pressure to a systolic level of between 100-130mmHg, where possible and without side effects, and to not worry about the diastolic blood pressure value.” 

Source: News-Medical.Net

Journal information: Arvanitis, M., et al. (2021) Linear and Nonlinear Mendelian Randomization Analyses of the Association Between Diastolic Blood Pressure and Cardiovascular Events. Circulation. doi.org/10.1161/CIRCULATIONAHA.120.049819.

Categories : Implants and ProsthesesTags :

Neural Control of Prosthetic Ankle Can Restore Agility

On By ModernMedia
Female athlete with prosthetic leg relaxes on a sporting field. Photo by Anna Shvets from Pexels

A recent case study demonstrates that, with training, neural control of a prosthetic ankle with a powered joint can restore agility. 

Traditional prosthetic ankle joints result in slower walking and abnormal gaits due to the way they differ from normal human ankles in distributing walking loads. Autonomously controlled powered prosthetic ankles can restore additional function to users by providing the extra work involved in a natural walking gait. However, they are currently only designed to assist walking or standing, and not to tackle specialised tasks such as squatting.

“This case study shows that it is possible to use these neural control technologies, in which devices respond to electrical signals from a patient’s muscles, to help patients using robotic prosthetic ankles move more naturally and intuitively,” said corresponding author Helen Huang, Jackson Family Distinguished Professor in the Joint Department of Biomedical Engineering at NC State and UNC

“This work demonstrates that these technologies can give patients the ability to do more than we previously thought possible,” says Aaron Fleming, first author of the study and a Ph.D. candidate in the joint biomedical engineering department.

Most research on robotic prosthetic ankles has focused on autonomous control, meaning that the prosthesis handles the fine motions when the wearer decides to walk or stan.

Huang, Fleming and their collaborators sought to find out if amputees could be trained to use a neurally controlled prosthetic ankle to regain more control in the many common motions that people make with their ankles beyond simply walking.

Their powered prosthesis reads electrical signals from two residual calf muscles, which are responsible for controlling ankle motion, and converts the signals into commands for moving the prosthesis.

The researchers recruited a study participant with an amputation between the knee and the ankle, and fitted the powered prosthetic ankle on the participant and did an initial evaluation. Over two and a half weeks, the participant then had five, two-hour training sessions with a physical therapist. A second evaluation was conducted on training completion.

Having had the training, the participant was able to perform a variety of previously challenging tasks, such as going from sitting to standing without any external assistance or squatting to pick something up without compensating for the movement with other body parts. However the participant’s own stability, both self-reported and empirically measured in such tests as standing on foam, was dramatically improved.

“The concept of mimicking natural control of the ankle is very straightforward,” Huang said. “But implementation of this concept is more complicated. It requires training people to use residual muscles to drive new prosthetic technologies. The results in this case study were dramatic. This is just one study, but it shows us what is feasible.”

“There is also a profound emotional impact when people use powered prosthetic devices that are controlled by reading the electrical signals that their bodies are making,” Fleming said. “It is much more similar to the way people move intuitively, and that can make a big difference in how people respond to using a prosthesis at all.”

More participants are already undergoing the training, with the researchers expanding their testing to match. But before this technology is made more widely available, the researchers would like real-world testing, with the prosthesis being used in people’s daily routines.

“As with any prosthetic device for lower limbs, you have to make sure the device is consistent and reliable, so that it doesn’t fail when people are using it,” Huang said.

“Powered prostheses that exist now are very expensive and are not covered by insurance,” Fleming explained. “So there are issues related to access to these technologies. By attempting to restore normal control of these type of activities, this technology stands to really improve quality of life and community participation for individuals with amputation. This would make these expensive devices more likely to be covered by insurance in the future if it means improving the overall health of the individual.”

The researchers are currently working with a larger group of study participants to see how broadly applicable the findings may be.

Source: News-Medical.Net

Journal information: Fleming, A., et al. (2021) Direct continuous electromyographic control of a powered prosthetic ankle for improved postural control after guided physical training: A case study. Wearable Technologies. doi.org/10.1017/wtc.2021.2.

Categories : Mental HealthTags :

Teens at Risk of Psychopathy Struggle with Moral Judgments

On By ModernMedia

Teenagers with high levels of callous-unemotional traits demonstrate lower levels of anticipated guilt towards the possibility of committing an immoral act and struggle to judge an immoral act as a wrong one.

In the study, researchers examined the callous traits, ie the lack of empathy and disregard for the wellbeing and feelings of others, of 47 adolescents from the Portuguese Population between 15 and 18 years old. The adolescent participants viewed video animations portraying examples of moral transgressions, such as incriminating someone or keeping money that fell from someone else’s pocket. “This approach allowed us to create more realistic scenarios that happen in daily life,” explained Oscar Gonçalves, a neuroscientist at Proaction Lab and co-author of the study. 
The participants were asked how guilty they would feel if they were the ones to commit the moral transgressions and how unethical they felt those actions to be.

The study results differ from what is known about psychopaths, despite the callous-unemotional traits in adolescents being known to be precursors of psychopathy in adulthood. “Adults with psychopathic traits show low levels of anticipated guilt but consider immoral actions as wrong. However, in our study, adolescents with high CU levels show levels of guilt and judge immoral actions as less wrong,” explained first author Margarida Vasconcelos.

But evidence was found of a dissociation between moral emotions and moral judgment, that is, between the feelings of guilt and the judgment of immoral actions. “Even in adolescents with sub-clinical levels of callous-unemotional traits, this dissociation typical in psychopathy in adulthood is already happening during development,” explained study coordinator Ana Seara Cardoso.

The study’s results will “contribute to the development of a severe anti-social behavior model” and allow the “development of intervention targets, rehabilitation and early prevention of anti-social behavior,” said Cardoso.

Source: Medical Xpress

Categories : NeurologyTags :

Eye Pressure in Glaucoma not the Whole Story

On By ModernMedia

The findings of a new study in rats show that a chemical known to protect nerve cells also slows glaucoma, the leading cause of irreversible blindness.

According to the National Glaucoma Foundation, in the US, over 3 million have glaucoma, with only half being aware of the fact and more than 120 000 are blind from the disease. The World Health Organization estimates that, worldwide, over 60 million individuals suffer from glaucoma.  

Led by researchers at NYU Grossman School of Medicine, the study centred on the watery fluid inside the eye on which its function depends. In patients with glaucoma, a buildup of fluid pressure wears down cells in the eyes and the nerves connecting them to the brain.

Previous research that despite eye pressure having been controlled, the condition progressively worsened. The relationship between pressure buildup and impaired vision remains poorly understood

The new study showed that when rats ingested the compound citicoline, optic nerve signals between the brain and eye were almost fully restored. Citicoline is a major source of choline, a building block in the membranes that line nerve cells and enhance nerve cell communication. It is produced in the brain but also commercially produced.

The study confirmed that increased eye pressure levels contributes to nerve damage in glaucoma, but  it also showed that citicoline reduced vision loss in rats without reducing pressure levels.

“Our study suggests that citicoline protects against glaucoma through a mechanism different from that of standard treatments that reduce fluid pressure,” said senior author Kevin Chan, PhD, an assistant professor in the Department of Ophthalmology at NYU Langone Health. “Since glaucoma interrupts the connection between the brain and eye, we hope to strengthen it with new types of therapies.”

The findings are helping scientists better understand how glaucoma works and add to past evidence that citicoline may counter the disease, said Chan, also the director of the Neuroimaging and Visual Science Laboratory at NYU Langone. It is known that humans and rodents with glaucoma have lower than normal levels of choline in the brain, but until now, Prof Chan says, there’s been little concrete evidence of the effectiveness of choline supplements as a therapy for glaucoma or why choline occurs in lower levels in glaucoma patients.

Prof Chan and his team tested whether increasing levels of that chemical would slow or even stop the degradation of the optic nerve and other regions of the brain involved in vision. Using a comprehensive study of the eye-brain connection in glaucoma, his team found that giving rats oral doses of citicoline over a three-week period protected nerve tissues and reduced vision loss sustainably even after the treatment stopped for another three weeks.

To simulate glaucoma, the researchers used a clear gel in rats to build up eye pressure mildly without otherwise blocking their vision. Then, the team used MRI imagery to measure the structural integrity and the amount of functional and physiological activity along the visual pathway. To test the clarity of vision of each eye, the researchers tracked the rodents’ visual behaviour .

It was found that for rats with mildly elevated eye pressure, the tissues that connect the eye and brain, including the optic nerve, degraded for up to five weeks after the injury. Nerve structure breakdown in the citicoline-treated rodents slowed by up to 74%, which the researchers said indicates that the chemical had protective effects on nerve cells.

However, more research is necessary before citicoline supplements to treat glaucoma in humans, as commercial drugs have yet to be proven fully effective in clinical trials. The researchers are planning next to look into how choline protects the eye and why it is depleted in glaucoma patients.

Source: Medical Xpress

Journal information: Yolandi van der Merwe et al, Citicoline Modulates Glaucomatous Neurodegeneration Through Intraocular Pressure-Independent Control, Neurotherapeutics (2021). DOI: 10.1007/s13311-021-01033-6

Categories : COVIDTags :

FDA and CDC Justify J&J Vaccine Pause

On By ModernMedia

FDA and CDC officials recommended pausing administration of the Johnson & Johnson COVID vaccine “out of an abundance of caution,” and mainly for the benefit of clinicians to respond to associated serious events.

This comes after six cases of cerebral venous sinus thrombosis (CVST) combined with thrombocytopenia were reported in the US, all among women ages 18-48. With approximately 6.8 million doses administered in the U.S., it suggests a one-in-a-million risk. 

J&J has halted distribution of its vaccine in Europe, reportedly taking officials there by surprise. South Africa has also paused the vaccine rollout.

At a media briefing, when asked whether pausing administration of the vaccine was an “overreaction,” Acting FDA Commissioner Janet Woodcock, MD, said the aim was to provide “time for the healthcare community to learn what they needed about how to diagnose, treat, and report” such events.

FDA’s director for the Center for Biologics Evaluation and Research, Peter Marks, MD, PhD, noted that the condition involves a rare blood clot for which heparin or related anticoagulants is not the standard treatment.

“The issue with these types of blood clots is if one administered standard treatment, one can actually cause tremendous harm or the outcome can be fatal,” he said. “One needs to make sure providers are aware if they see people with low blood platelets or blood clots, to inquire about recent vaccination and act accordingly.”

The background rate of CVST is 2-14 per million in the setting of a normal platelet count, but thrombocytopenia together with abnormal clotting makes it a “pattern.” CVST symptoms also include severe headache, abdominal pain, leg pain, and shortness of breath.

Marks noted that vaccination-related headaches tend to resolve within a few days, whereas CVST symptoms could manifest over a week post-vaccination, and closer to a patient presenting to the emergency department with severe headache. No such rare events have been seen more than 3 weeks post-vaccination.

Dr Marks also said that this pause is a recommendation but does not prevent healthcare providers from providing the J&J vaccine to their patients should benefits of vaccination outweigh the risks.

“We’re not going to stop a provider from administering a vaccine,” he added. “The benefit/risk will be beneficial overall to that individual in a large majority of cases.”

Dr Marks said that while they don’t have a “definitive cause” for the adverse reactions, data from AstraZeneca on similar events in Europe, it is likely a “similar mechanism” with the J&J vaccine. An autoantibody against platelet factor 4 has recently been identified as the trigger for the reaction.
“The immune response occurs rarely after some people receive the vaccine, and that immune response leads to the activation of platelets and extremely rare blood clots,” he said.

However, Marks stopped short of calling it a “class effect,” meaning it was related to the viral vector vaccine itself. He said he wasn’t ready to make a “broad statement yet,” but “obviously it’s from the same general class of viral vectors.”

The AstraZeneca, J&J and Sputnik V vaccines all use adenovirus vectors to deliver antigens. The rate CVST for AstraZeneca was estimated by European officials to be about 5 per million doses. Though Sputnik V has no confirmed CVST cases, a recent report suggests a possibility.

Besides these, the Ebola vaccines are the only other ones to use adenovirus vectors.
Woodcock said that all US cases were in women of reproductive age, with one death and one hospitalisation, but Marks said it was not clear there was any association with hormonal contraception, which also carries a small thrombosis risk. The cases did not have any preexisting conditions which could have explained the events.

The American College of Obstetricians and Gynecologists (ACOG) noted there is no “clear phenotype” for women who may experience this complication.

“Until there is a better understanding of the frequency and impact of this finding, it will be important to encourage pregnant and postpartum women who wish to be vaccinated to receive the mRNA vaccines: Pfizer or Moderna,” said Christopher Zahn, MD, vice president for practice activities at ACOG, in a statement.

“If venous thrombosis is noted in the setting of thrombocytopenia, treatment includes intravenous immunoglobulin and other supportive care,” Dr Zahn added.

Source: MedPage Today

Categories : General InterestTags :

Wrangle Over GoFundMe For Family of Deceased Nurse

On By ModernMedia

The family of a pregnant nurse who died with COVID have yet to receive any money from a GoFundMe campaign that names them as beneficiaries.

Mary Agyapong, 28, died after giving birth in April 2020 at Luton and Dunstable Hospital, where she worked. At 35 weeks pregnant, she was admitted to hospital April 5 after having collapsed with breathing difficulties, but was discharged the same day, despite her misgivings. She was readmitted two days later with COVID symptoms. She gave birth to a daughter by Caesarean section and was then transferred to intensive care on April 8, where she died four days later.

On April 15, family friend Rhoda Asiedu set up a GoFundMe page to support “Mary’s husband, and the couple’s children… during this heavy and trying time”, and has raised more than £186 000 (R3 720 000). This money had been placed into a trust, according to her lawyers.

Ms Agyapong’s widower said he found it “surprising” he had not been involved.

Coroner Emma Whitting, at an inquest held last month, said that it was “unclear” how mother-of-two Ms Agyapong contracted COVID before her death. She then urged Prime Minister Boris Johnson to begin a public inquiry into the pandemic.

The funds raised were paid to Ms Asiedu’s legal team, Blue Trinity, who said it had been placed “on trust” for the education of Ms Agyapong’s children and that 80% would be released when they turned 21. The remaining 20% would be provided to Ms Agyapong’s widower Ernest Boateng for “maintenance and upkeep” of the children, but he had “failed to co-operate with the trustees to arrange a schedule of maintenance”.
Blue Trinity however has not responded to requests from the BBC or Mr Boateng’s legal team to see the trust documents.

“I just try to keep my head above the water,” said Mr Boateng, who is studying law. “I find it very surprising that we have not been asked or involved with this GoFundMe money – it’s beyond my understanding.”

GoFundMe stated that it was clear from the outset that the money would be placed in a trust, adding: “Our records show the wording of the page has not been changed since it launched on 15 April 2020.”

However, an archived snapshot of the webpage on 16 April found by the BBC made no reference to a trust at all. When fundraiser Ms Asiedu was contacted by the BBC, she directed media requests to her legal team.

Source: BBC News