Day: September 2, 2021

Categories : Skeletal SystemTags :

Insights into Stiffness Prognosis of Knee Replacements

On By ModernMedia
Phot by Nino Liverani on Unsplash

A new study could help physicians better manage patients who experience debilitating stiffness after they undergo knee replacement surgery.

Researchers at Hospital for Special Surgery (HSS) in New York City presented their findings at the American Academy of Orthopaedic Surgeons (AAOS) 2021 annual meeting

Stiffness after knee replacement surgery, or total knee arthroplasty (TKA), is a rare but frustrating complication, affecting between 1% and 7% of patients who receive the artificial joints. “Why some people and not others experience limited range of motion after TKA is unknown,” said Ioannis Gkiatas, MD, PhD, an orthopedic surgeon at the University of Ioannina, in Greece, and the first author of the new study.

“The goal of the study was to see if we can help physicians predict how patients will do following the revision surgery, using information gathered before and after the procedure, to shape their postoperative treatment plans,” said Dr. Gkiatas. The work was conducted under the supervision of Peter K. Sculco, MD, hip and knee surgeon at HSS, who is leading a large, ongoing study of patient outcomes after revision TKA for reduced range of motion after index TKA.

The researchers followed 19 men and women who underwent revision TKA at HSS to try to improve stiffness in patients with prior TKA. Patients underwent range of motion testing before the procedure and at six weeks, six months and one year after the operation.

The range of motion of healthy knees ranges from full extension (0 degrees) through the sitting position (90 degrees) to kneeling (approximately 140 degrees). All patients gained an average of 28 degrees of motion after the revision surgery. The benefit mostly appeared in the first six weeks after the operation, then gradually tapered off over time.

Patients with the least restricted mobility had the greatest gains from the revision surgery. Patients who could able to bend their affected knee more than 82 degrees before TKA revision had an 80 percent chance of maintaining that level of mobility, or gaining flexibility in the joint, after the operation and throughout the follow-up period.

However, two-thirds of patients whose range of motion was less than 64 degrees prior to surgery experienced regression in that mobility during the study, never attaining the 82-degree threshold.

“Although 82 degrees doesn’t seem much more than 64 degrees, for the patient it’s a significant difference. With 82 degrees you can perform the basic activities of everyday life,” Dr Gkiatas said. “With these new data, if at six weeks a patient reaches 82 degrees of motion in their knee, we can say they have an 80 percent chance of at least maintaining this range of motion one year after surgery.” 

The study results provide surgeons with the information needed to educate patients with stiff TKA on expected range of motion outcomes after revision surgery: Less than 60 degrees is a poor prognostic finding. Additionally, when patients return for their six-week appointment after revision TKA, and have less than 82 degrees of motion, additional pharmacologic or manual knee manipulation treatments should be done since this patient is at a high risk for range of motion regression and inferior clinical outcome at one-year post-revision.

Source: EurekaAlert!

Categories : COVIDTags :

New Antiviral Drug for COVID to Be Trialled in SA

On By ModernMedia
Source: CDC

Codivir, a new antiviral drug with promising effects against COVID, will be trialled in South Africa.

Following on from the phase I study’s successful completion, Code Pharma, a Dutch pharmaceutical company developing Codiviir, is starting phase II double-blind controlled study in Spain, Brazil, South Africa and Israel.

Codivir is a short synthetic 16 amino-acid peptide, originally derived from HIV peptides. Code Pharma discovered the peptide’s direct antiviral effect against SARS-CoV-2 after in vitro studies at the British virology research laboratory, Virology Research Services in London.

Codivir was tested in a phase I trial in São Paulo, Brazil, where researchers found that Codivir had a high safety profile while significantly suppressing viral replication in most of the fully assessed patients. All treated patients recovered quickly and no side effects often associated with COVID infections were seen. The results also indicated that Codivir might have a similar beneficial effect on other RNA viruses such as influenza.

Lead researchers from the Department of Medicine at Hadassah Medical Center, Dr Yotam Kolben and Dr Asa Kesler said the antiviral drug had potential for improving the current therapies for COVID.

“The pre-clinical data and the results of the clinical trial support the safety of Codivir administration in humans and suggest its significant anti-COVID effect,” the researchers said.

Professor Shlomo Maayan, director of the Infectious Disease division at the Barzilai Medical Center, said Codivir had a very good safety profile and an impressive antiviral effect, both in the lab and in the phase I clinical trials.

“We eagerly await the results of the double-blind studies using Codivir. It may be a breakthrough in the field of antiviral therapy for COVID patients,” said Prof Maayan.

Source: Biospace

Categories : Mental HealthTags :

Impacts of Sleep Deprivation Linger a Week Later

On By ModernMedia
Photo by Mert Kahveci on Unsplash

A Polish study found that, after a week-long recovery from sleep deprivation, only reaction speed is restored to baseline levels while other functions are still lacking.

The negative impacts of sleep deficiency are well known, and include deficits in attention and memory, increased risk of car accidents, heart problems, and other medical issues. However, while some research has addressed recovery after chronic sleep deprivation, it has been unclear how much time is needed to fully recover from prolonged periods of deficient sleep.

To shed more light on this topic, Jeremi Ochab of the Jagiellonian University in Kraków and colleagues conducted a small study, published in PLOS ONE, with several healthy adults who underwent 10 days of purposeful sleep restriction followed by seven recovery days with unrestricted sleep. Participants completed the study in their normal day-to-day environments, wearing wrist sensors to track sleep and activity. Daily electroencephalography (EEG) monitored their brain activity, and they answered daily questions (Stroop tasks) to measure reaction times and accuracy.

After 7 days of recovery, the participants had not yet returned to their baseline performance on most measures of functioning. These included several EEG measures of brain activity, rest-versus-activity patterns captured by wrist sensors, and accuracy on Stroop tasks. Only their reaction times had recovered to baseline levels.

While the researchers note that it is difficult to compare these results with other studies that employed different methods, the findings contribute new insights into recovery from chronic sleep loss. Future research could include more participants, investigate longer recovery periods, and determine in what order different functions return to normal.

The authors added: “The investigation of the recovery process following an extended period of sleep restriction reveal that the differences in behavioural, motor, and neurophysiological responses to both sleep loss and recovery.”

Source: SciTech Daily

Categories : Medical Research & TechnologyTags :

New Prosthetic Arm Restores Normal Movements

On By ModernMedia
A prosthetic arm being fitted. Source: This is Engineering on Unsplash

Researchers have developed a bionic arm for patients with upper-limb amputations that allows wearers to think, behave and function like a person without an amputation.

The arm combines three important functions – intuitive motor control, touch and grip kinaesthesia, the intuitive feeling of opening and closing the hand. The developers, led by Clevelend Clinic, published their findings in Science Robotics.

“We modified a standard-of-care prosthetic with this complex bionic system which enables wearers to move their prosthetic arm more intuitively and feel sensations of touch and movement at the same time,” said lead researcher Paul Marasco, PhD, associate professor  in Cleveland Clinic Lerner Research Institute’s Department of Biomedical Engineering. “These findings are an important step towards providing people with amputation with complete restoration of natural arm function.”

The system is the first to test all three sensory and motor functions in a neural-machine interface simultaneously in a prosthetic arm. The neural machine interface sends impulses from the brain to the arm and sensory information back to the brain.

“Perhaps what we were most excited to learn was that they made judgments, decisions and calculated and corrected for their mistakes like a person without an amputation,” said Dr Marasco. “With the new bionic limb, people behaved like they had a natural hand. Normally, these brain behaviors are very different between people with and without upper limb prosthetics.
The researchers tested their new bionic limb on two study participants with upper limb amputations who had previously undergone targeted sensory and motor reinnervation -procedures that establish a neural-machine interface by redirecting amputated nerves to remaining skin and muscles. 

In targeted sensory reinnervation, touching the skin with small robots activates sensory receptors that enable patients to perceive the sensation of touch. In targeted motor reinnervation, when patients think about moving their limbs, the reinnervated muscles communicate with a computerised prosthesis to move in the same way. Additionally, small, powerful robots vibrate kinesthetic sensory receptors in those same muscles which helps prosthesis wearers feel that their hand and arm are moving. The new prosthetic arm feels grip movement sensation, touch on the fingertips, and is controlled intuitively by thinking. Cameras lets the computer see the prosthetic’s position.

While wearing the advanced prosthetic, participants performed tasks reflective of basic, everyday behaviours that require hand and arm functionality, which were compared to people with traditional prosthetics and people without amputations.

According to Dr Marasco, because the limb lacks sensation, people with traditional prosthetics behave differently than people without an amputation when performing tasks. For example, traditional prosthesis wearers must constantly watch their prosthetic while using it, and have difficulty correcting for the correct amount of force needed.

The researchers could see that the study participants’ brain and behavioural strategies changed to match those of a person without an amputation. They no longer needed to watch their prosthesis, they could locate things without looking, and they could more effectively correct mistakes.

“Over the last decade or two, advancements in prosthetics have helped wearers to achieve better functionality and manage daily living on their own,” said Dr. Marasco. “For the first time, people with upper limb amputations are now able to again ‘think’ like an able-bodied person, which stands to offer prosthesis wearers new levels of seamless reintegration back into daily life.”

Source: Cleveland Clinic

Categories : CancerTags :

Humans Still Beat AI in Breast Cancer Screening

On By ModernMedia
Source: National Cancer Institute

A review in The BMJ finds that humans still seem to beat AI when it comes to the accuracy of spotting possible cases of breast cancer during screening.

At this point, there is a lack of good quality evidence to support a policy of replacing human radiologists with artificial intelligence (AI) technology when screening for breast cancer, the researchers concluded.

A leading cause of death for among women the world over, mammography screening is a high volume, repetitive task for radiologists, and some cancers are not picked up.

Previous research has suggested that AI systems outperform humans and might soon be used instead of experienced radiologists. However, a recent review of 23 studies highlighted evidence gaps and concerns about the methods used.

To address this uncertainty, researchers reviewed 12 studies carried out since 2010. They found that, overall, the methods used in the studies were of poor quality, with low applicability to European or UK breast cancer screening programmes.

Three large studies involving nearly 80 000 women compared AI systems with the clinical decisions of the original radiologist. Of these, 1878 had screen detected cancer or interval cancer (cancer diagnosed in-between routine screening appointments) within 12 months of screening.

The majority (34 out of 36 or 94%) of AI systems in these three studies were less accurate than a single radiologist, and all were less accurate than the consensus of two or more radiologists, which is the standard practice in Europe.

In contrast, five smaller studies involving 1086 women reported that all of the AI systems evaluated were more accurate than a single radiologist. However, these were at high risk of bias and not replicated in larger studies.

In three studies, AI used as a pre-screen to triage which mammograms need to be examined by a radiologist and which do not screened out 53%, 45%, and 50% of women at low risk but also 10%, 4%, and 0% of cancers detected by radiologists.

The authors point to some study limitations such as excluding non-English studies, as well as the fast pace of AI development. Nevertheless, stringent study inclusion criteria along with rigorous and systematic evaluation of study quality suggests their conclusions are robust.

As such, the authors said: “Current evidence on the use of AI systems in breast cancer screening is a long way from having the quality and quantity required for its implementation into clinical practice.”

They added: “Well designed comparative test accuracy studies, randomized controlled trials, and cohort studies in large screening populations are needed which evaluate commercially available AI systems in combination with radiologists in clinical practice.”

Source: Medical Xpress

Categories : Metabolic DisordersTags :

GPs Should Aim for Diabetes Remission Through Weight Loss

On By ModernMedia
Photo by i yunmai on Unsplash

A large-scale review of clinical evidence concluded that achieving ‘remission’ for people with type 2 diabetes through dietary approaches and weight loss should be the primary treatment goal of GPs and healthcare practitioners.

Corresponding author Dr Duane Mellor at Aston University said: “Accounting for all the evidence, our review suggests remission should be discussed as a primary treatment goal with people living with type 2 diabetes. There are multiple dietary approaches that have been shown to bring about T2DM remission though at present meal replacements offer the best quality evidence. Low carbohydrate diets have been shown to be highly effective and should also be considered as a dietary approach for remission.”

Lead author, Dr Adrian Brown, UCL Division of Medicine said: “Traditionally T2DM has focussed on managing a person’s blood glucose with medication, however the approach doesn’t address the underlying causes of T2DM. There is now a growing body of research that shows losing significant weight, 10-15kg, either through weight loss surgery or dietary approaches, can bring about type 2 diabetes remission (non-diabetic blood sugar levels).”

Expert reviewers analysed over 90 research papers covering international clinical trials and clinical practice data of dietary methods used to treat T2DM. Their findings were published in the Journal of Human Nutrition & Dietetics.

The study found that meal-replacement diets helped 36% people successfully achieve remission, while low carbohydrate diets were able to help 17.6 % of people achieve and maintain remission for at least two years. People who lost the most weight and kept the weight off using both of these dietary approaches were able to stay in remission.

Calorie restricted and Mediterranean diets were somewhat less effective, with only about 5% of people on calorie restricted diets and 15% of people on a Mediterranean diet staying in remission after one year.

There were multiple definitions of ‘remission’: one is a return to non-diabetic blood sugar levels (glycated haemoglobin less than 48mmol/mol), without diabetes drugs. Other definitions however say weight (especially fat around the midsection) must be lost to achieve remission, and others allow medication to be used.

Some reports also suggested low-carbohydrate diets can normalise blood sugar levels even without weight loss, since carbohydrates cause blood sugar levels to rise. A low-carbohydrate diet means reduced blood sugar, leading to improved blood sugar control. However, if weight is lost without blood glucose being non-diabetic, the authors are suggesting this should instead be called mitigation, as the underlying mechanisms of T2DM are not being addressed.

Dr Brown said: “The evidence is clear that the main driver of remission remains the degree of weight loss a person achieved. Therefore, for those not achieving weight loss but achieving a non-diabetic blood glucose we are suggesting this isn’t remission per se, but rather ‘mitigation’ of their diabetes.”

The review concluded that while weight loss seems to best predict remission success, it assumes fat loss from the pancreas and liver. Future studies should compare how these diets work for different ethnic groups, as T2DM can occur at different body weights in different ethnic groups.

Dr Mellor added: “Not everyone will be able to achieve remission, but people who are younger (less than 50), male, have had type 2 diabetes for less than six years and lose more weight are more likely to be successful.”

Source: Ashton University