Tag: 11/11/24

Categories : Implants and Prostheses Skeletal SystemTags : Leave a comment

Study Identifies Hip Implant Materials with Lowest Risk of Revision

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Photo by DanR on Flickr

Hip implants with a delta ceramic or oxidised zirconium head and highly crosslinked polyethylene liner or cup had the lowest risk of revision during the 15 years after surgery, a new University of Bristol-led study has found. The research could help hospitals, surgeons and patients to choose what hip implant to use for replacement surgery.

The aim of the study, which appears in PLOS Medicine, was to establish hip implant materials at risk of revision. This would help orthopaedic surgeons, and patients, and to improve shared decision making before surgery by identifying hip implants with the lowest risk of revision.

The researchers analysed the UK’s National Joint Registry (NJR) data from 1 026 481 hip replacement patients carried out in the NHS and private sectors in England and Wales for up to 15 years after initial hip replacement operations (between 2003 to 2019). 

After reviewing hip implants from the NJR data, the research team found the risk of revision following a hip replacement is influenced by the type of material used in the bearing surface. Bearing surfaces are the moving parts of an artificial hip joint that glide against each other during activity.

The data indicated that hip implants with a delta ceramic or oxidised zirconium head and highly crosslinked polyethylene liner or cup had the lowest risk of revision throughout the 15 years following hip replacement surgery.

These findings were confirmed when the research team investigated the specific reasons for revision hip replacements being performed.  The data also showed 20 869 (2%) of hip replacement patients had to undergo revision after the initial surgery.

Senior author Dr Erik Lenguerrand, Senior Lecturer in Medical Statistics and Quantitative Epidemiologist in the Bristol Medical School: Translational Health Sciences (THS), said: “Our research has found the risk of hip replacement revision depends on the hip implant materials used in the original surgery.  The lowest risk of revision are from implants with delta ceramic or oxidised zirconium head and a highly crosslinked polyethylene (HCLPE) liner or cup.

“Further research is needed to find out the association of implant materials with the risk of rehospitalisation, re-operation other than revision, mortality and the cost-effectiveness of these materials.”

Michael Whitehouse, Professor of Trauma and Orthopaedics at Bristol Medical School: THS, and senior clinical lead for the paper, explained: “Our study has used data from one of the largest registries in the world that includes all public and private health care sectors in England and Wales. This means that the data is more generally applicable than that available previously, which was limited by broad groupings of implant types or much smaller study size. It highlights the importance of considering the whole structure that is created when implants are put together to make up a hip replacement rather than focusing on individual components.

“Our findings will help hospitals, surgeons and patients to choose hip implants and combinations of them with the lowest risk of revision following an initial hip replacement operation.”

Tim Wilton, Medical Director of the National Joint Registry (NJR), added: “We are always delighted when the data from the NJR can be used by researchers to produce important research of this kind which gives meaningful analysis to guide surgeons and patients in their decisions. An important value of the NJR data is that it allows researchers a unique insight to assess the long-term performance of different hip implant materials.

“By tracking the combinations of materials used and subsequent revision rates, this research highlights the role of implant material choice in surgical outcomes. This ensures that the materials used can be optimised for longevity and patient health. Surgeons would be well advised to study these findings carefully in relation to the implant choices they make, and to use the information in pre-operative discussions with their patients. As the demand for joint replacements continues to rise, this insight can be invaluable in reducing revision surgery.”

The research was not a randomised controlled trial and therefore it was not possible to control all factors that can influence the risk of revision.

The categorisation of hip implants used as part of hip replacements is often broad in national joint replacement surgery registries and does not fully show differences in revision risks associated within the different types of implant materials grouped together.

Source: University of Bristol

Categories : GastrointestinalTags : Leave a comment

Gut Health Signals could Transform Arthritis Treatment

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Gut Microbiome. Credit Darryl Leja National Human Genome Research Institute National Institutes Of Health

Changes in the gut microbiome before rheumatoid arthritis is developed could provide a window of opportunity for preventative treatments, new research suggests.

Bacteria associated with inflammation is found in the gut in higher amounts roughly 10 months before patients develop clinical rheumatoid arthritis, according to a longitudinal study by researchers at the University of Leeds. 

This new research might give us a major opportunity to act sooner to prevent rheumatoid arthritis.

Dr Christopher Rooney, Leeds Institute of Medical Research

Previous research has linked rheumatoid arthritis to the gut microbiome, which is the ecosystem of microbes in your intestines. But this new study, published in the Annals of the Rheumatic Diseases, reveals a potential intervention point. 

Lead researcher Dr Christopher Rooney, NIHR Academic Clinical Lecturer at the University of Leeds and Leeds Teaching Hospitals NHS Trust, said: “Patients at risk of rheumatoid arthritis are already experiencing symptoms such as fatigue and joint pain, and they may know someone in their family who has developed the disease. As there is no known cure, at-risk patients often feel a sense of hopelessness, or even avoid getting tested.  

“This new research might give us a major opportunity to act sooner to prevent rheumatoid arthritis.” 

Major opportunity for treatment

Funded by Versus Arthritis, the longitudinal study was conducted on 19 patients at risk of rheumatoid arthritis, with samples taken five times during a 15-month period.  

Five of these patients progressed to clinical arthritis, and the research showed they had gut instability with higher amounts of bacteria including Prevotella, which is associated with rheumatoid arthritis, about ten months before progression. The remaining 14, whose disease didn’t progress, had largely stable amounts of bacteria in their gut. 

Potential treatments that the researchers want to test at the 10-month window include changes to diet like eating more fibre, taking prebiotics or probiotics, and improving dental hygiene to keep harmful bacteria from periodontal disease away from the gut. 

The exact relationship between gut inflammation and rheumatoid arthritis development remains unclear. In a small number of patients within the study, the gut changes occurred before there were any changes to the joints observed by a rheumatologist, but more research is needed to determine whether these influence each other. 

Although bacteria is associated with rheumatoid arthritis, the researchers want to make it clear that there is no evidence this is contagious. 

Lucy Donaldson, director for research and health intelligence at Versus Arthritis, said: “At Versus Arthritis, we welcome the findings of this study which could give the clinicians of the future a crucial window of opportunity to delay – or even prevent – the onset of rheumatoid arthritis. This success is testament to the dedication of UK researchers who are working to personalise treatment and prevent chronic conditions that have significant impacts on a person’s ability to work, raise families and live independently.” 

The study initially took data from 124 individuals who had high levels of CCP+, an antibody that attacks healthy cells in the blood, which indicates risk of developing rheumatoid arthritis. The researchers compared their samples to 22 healthy individuals and seven people who had a new rheumatoid arthritis diagnosis.  

The findings from this larger group showed that the gut microbiome was less diverse in the at-risk group, compared to the healthy control group. 

The longitudinal study, which took samples from 19 patients over 15 months, revealed the changes in bacteria at ten months before progression to rheumatoid arthritis. 

The Leeds research team will now carry out an analysis of treatments that have already been trialled, to inform future testing of treatments at this potential 10-month intervention point. 

Source: University of Leeds

Categories : Mental Health NeurologyTags : Leave a comment

Bilateral Magnetic Stimulation of the Brain Improves Symptoms of Depression

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By Baburov – Own work, CC BY-SA 4.0, Link

A type of therapy that involves applying a magnetic field to both sides of the brain has been shown to be effective at rapidly treating depression in patients for whom standard treatments have been ineffective.

Our accelerated approach means we can do all of the sessions in just five days, rapidly reducing an individual’s symptoms of depression

Valerie Voon

The treatment – known as repetitive transcranial magnetic stimulation (TMS) – involves placing an electromagnetic coil against the scalp to relay a high-frequency magnetic field to the brain.

Around one in 20 adults is estimated to suffer from depression. Although treatments exist, such as anti-depressant medication and cognitive behavioural therapy (‘talking therapy’), they are ineffective for just under one in three patients.

One of the key characteristics of depression is under-activity of some regions (such as the dorsolateral prefrontal cortex) and over-activity of others (such as the orbitofrontal cortex (OFC)).

Repetitive transcranial magnetic stimulation applied to the left side of the dorsolateral prefrontal cortex (an area at the upper front area of the brain) is approved for treatment of depression in the UK by NICE and in the US by the FDA. It has previously been shown to lead to considerable improvements among patients after a course of 20 sessions, but because the sessions usually take place over 20-30 days, the treatment is not ideal for everyone, particularly in acute cases or where a person is suicidal.

In research published in Psychological Medicine, scientists from Cambridge, UK, and Guiyang, China, tested how effective an accelerated form of TMS is. In this approach, the treatment is given over 20 sessions, but with four sessions per day over a period of five consecutive days.

The researchers also tested a ‘dual’ approach, whereby a magnetic field was additionally applied to the right-hand side of the OFC (which sits below the dorsolateral prefrontal cortex).

Seventy-five patients were recruited to the trial from the Second People’s Hospital of Guizhou Province in China. The severity of their depression was measured on a scale known as the Hamilton Rating Scale of Depression.

Participants were split randomly into three groups: a ‘dual’ group receiving TMS applied first to the right- and then to the left-hand sides of the brain; a ‘single’ group receiving sham TMS to the right-side followed by active TMS applied to the left-side; and a control group receiving a sham treatment to both sides. Each session lasted in total 22 minutes.

There was a significant improvement in scores assessed immediately after the final treatment in the dual treatment group compared to the other two groups. When the researchers looked for clinically-relevant responses – that is, where an individual’s score fell by at least 50% – they found that almost half (48%) of the patients in the dual treatment group saw such a reduction, compared to just under one in five (18%) in the single treatment group and fewer than one in 20 (4%) in the control group.

Four weeks later, around six in 10 participants in both the dual and single treatment groups (61% and 59% respectively) showed clinically relevant responses, compared to just over one in five (22%) in the control group.

Professor Valerie Voon from the Department of Psychiatry at the University of Cambridge, who led the UK side of the study, said: “Our accelerated approach means we can do all of the sessions in just five days, rapidly reducing an individual’s symptoms of depression. This means it could be particularly useful in severe cases of depression, including when someone is experiencing suicidal thoughts. It may also help people be discharged from hospital more rapidly or even avoid admission in the first place.

“The treatment works faster because, by targeting two areas of the brain implicated in depression, we’re effectively correcting imbalances in two import processes, getting brain regions ‘talking’ to each other correctly.”

The treatment was most effective in those patients who at the start of the trial showed greater connectivity between the OFC and the thalamus (an area in the middle of the brain responsible for, among other things, regulation of consciousness, sleep, and alertness). The OFC is important for helping us make decisions, particularly in choosing rewards and avoiding punishment. Its over-activity in depression, particularly in relation to its role in anti-reward or punishment, might help explain why people with depression show a bias towards negative expectations and ruminations.

Dr Yanping Shu from the Guizhou Mental Health Centre, Guiyang, China, said: “This new treatment has demonstrated a more pronounced – and faster – improvement in response rates for patients with major depressive disorder. It represents a significant step forward in improving outcomes, enabling rapid discharge from hospitals for individuals with treatment-resistant depression, and we are hopeful it will lead to new possibilities in mental health care.”

Dr Hailun Cui from Fudan University, a PhD student in Professor Voon’s lab at the time of the study, added: “The management of treatment-resistant depression remains one of the most challenging areas in mental health care. These patients often fail to respond to standard treatments, including medication and psychotherapy, leaving them in a prolonged state of severe distress, functional impairment, and increased risk of suicide.

“This new TMS approach offers a beacon of hope in this difficult landscape. Patients frequently reported experiencing ‘lighter and brighter’ feelings as early as the second day of treatment. The rapid improvements, coupled with a higher response rate that could benefit a broader depressed population, mark a significant breakthrough in the field.”

Just under a half (48%) of participants in the dual treatment group reported local pain where the dual treatment was applied, compared to just under one in 10 (9%) of participants in the single treatment group. However, despite this, there were no dropouts.

For some individuals, this treatment may be sufficient, but for others ‘maintenance therapy’ may be necessary, with an additional day session if their symptoms appear to be worsening over time. It may also be possible to re-administer standard therapy as patients can then become more able to engage in psychotherapy. Other options include using transcranial direct current stimulation, a non-invasive form of stimulation using weak electrical impulses that can be delivered at home.

The researchers are now exploring exactly which part of the orbitofrontal cortex is most effective to target and for which types of depression.

The research was supported by in the UK by the Medical Research Council and by the National Institute for Health and Care Research Cambridge Biomedical Research Centre.*

Reference
Cui, H, Ding, H & Hu, L et al. A novel dual-site OFC-dlPFC accelerated repetitive transcranial magnetic stimulation for depression: a pilot randomized controlled study. Psychological Medicine; 23 Oct 2024; DOI: 10.1017/S0033291724002289

*A full list of funders is available in the journal paper.

Source: University of Cambridge. The original text of this story is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Note: Content may be edited for style and length.

Categories : COVID Immune SystemTags : Leave a comment

SARS-CoV-2 Hijacks Three Key Proteins in the Complement System

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SARS-CoV-2 viruses (yellow) infecting a human cell (blue). Photo by CDC on Pexels

Researchers at the Medical University of Vienna and the Medical University of Innsbruck discovered that SARS-CoV-2 hijacks three important host proteins that dampen the activity of the complement system, a key component of early antiviral immunity. This significantly impairs viral clearance which may affect the course of both acute COVID infections and post-COVID sequelae. The study was recently published in the journal Emerging Microbes & Infections.

An early and effective immune response is crucial for resolving viral infections and preventing post-infectious complications. The complement system, a pivotal element of antiviral immunity, is a cascade of proteins found in the bloodstream and at mucosal sites, such as the respiratory tract. Activated through three different pathways, complement facilitates the clearance of virus particles by directly inducing their destruction (lysis). To prevent bystander damage to host cells, complement is rapidly inactivated by a set of host molecules referred to as complement regulatory proteins. The new study led by Anna Ohradanova-Repic and colleagues from the Center for Pathophysiology, Infectiology and Immunology at the Medical University of Vienna in collaboration with the team of Heribert Stoiber from the Institute of Virology at the Medical University of Innsbruck shows that SARS-CoV-2 hijacks three of these regulatory proteins, CD55, CD59 and Factor H, and thereby successfully shields itself from complement-mediated lysis.

Hijacking host proteins for effective complement resistance

By propagating SARS-CoV-2 in human cells the researchers discovered that the virus particles acquire the cellular proteins CD55 and CD59. Further experiments showed that SARS-CoV-2 also binds to Factor H, another complement regulatory protein that is primarily found in the bloodstream. Confronting the virus particles with active complement revealed that they are partially resistant to complement-mediated lysis. By removing CD55, CD59 and Factor H from the virus surface or inhibiting their biological functions, the researchers could successfully restore complement-mediated clearance of SARS-CoV-2.

“Through hijacking these three proteins, SARS-CoV-2 can evade all three complement pathways, resulting in reduced or delayed viral clearance by the infected host,” Anna Ohradanova-Repic, the leader of the study explains. Because complement is intricately linked with other components of the immune system, this not only affects virus elimination but can also cause significant inflammation, a core feature of both severe COVID-19 and Long COVID. “Uncovering immune evasion mechanisms that allow the virus to linger within the host for longer, deepen our understanding of the acute and long-term impacts of SARS-CoV-2 infection,” says first author Laura Gebetsberger.

Source: Medical University of Vienna

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An Unexpected Effect Unlocks New Treatment Option for Prostate Cancer

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Credit: Darryl Leja National Human Genome Research Institute National Institutes Of Health

An international research team led by MedUni Vienna may have found a new cancer treatment strategy – by activating a pathway which normally promotes cancer. Unexpectedly, this turned out to not only slow tumour growth, but also stimulates the immune system to combat tumour cells. The results of the study have just been published in Molecular Cancer.

The scientific team focused its investigations on the GP130 signalling pathway, which researchers expect to have a major potential in the fight against cancer. The signalling pathway, which is mediated by the protein GP130, plays a central role in cell communication and influences the activity of the transcription factor STAT3, which in turn is associated with the development and spread of tumours. Accordingly, blocking the GP130 signalling pathway is currently seen as a great hope in cancer medicine. Yet the current study proves the opposite: tumour growth can be slowed down not by inhibiting but by activating the GP130 signalling pathway in prostate cells.
 
New hope, especially for aggressive tumours

To achieve these new findings, the researchers investigated genetically modified mice in which GP130 was specifically activated in the prostate. “This allowed us to directly observe the reduction in tumour growth in the cell,” reports Lukas Kenner (Clinical Department of Pathology, MedUni Vienna), who led the study together with Stefan Rose-John (Biochemical Institute, University of Kiel). The results were further backed up by analyses of tissue samples from prostate cancer patients. This showed that high GP130 values correlate with a better survival rate. At the same time, extensive molecular analyses were carried out, including gene expression profiling.

“Our research provides exciting new evidence that the activation of GP130 in prostate cells not only slows tumour growth, but also stimulates the immune system to actively fight the cancer cells,” says Lukas Kenner, summarising the significance of the results, which will now be confirmed in further studies. The research work opens up a promising new therapeutic option, particularly for aggressive prostate cancer, which is still difficult to treat.

Source: Medical University of Vienna