Tag: 3/11/21

Categories : Cancer Diseases, Syndromes and ConditionsTags :

Treating Cancer with the Toxoplasma Gondii Parasite

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Source: National Cancer Institute on Unsplash

Scientists have discovered that Toxoplasma gondii, a parasite known to cause illness in pregnant women and immunocompromised patients, could potentially enhance the treatment of various types of tumours.

The parasite Toxoplasma gondii is a single-celled opportunistic protozoan capable of infecting a broad range of warm-blooded animals and has been reported in nearly one-third of the world’s human population. It has a number of health effects, including a strong link to schizophrenia and has even been associated with increased suicide attempts in mothers.

While many treatments have been able to treat tumours and prolong the lives of patients, there is a need to further enhance these. In the study, published in the Journal for ImmunoTherapy Cancer, scientists found that the commonly found parasite  is able to sensitise ‘cold’  tumours, that is, tumours unlikely to trigger a strong immune response, to immune checkpoint blockade therapy.

The researchers believe that this finding could have broader therapeutic implications for many types of cancers.

T. gondii has to live inside the cells of its host and secretes numerous proteins to counter the host’s immune defences and to facilitate their own invasion and colonisation of the host cells. The researchers first built a T. gondii mutant strain with limited growth and disease-causing ability, but which is also able to manipulate the host immune system.

By directly injecting this mutant parasite into solid tumours, it induces inflammatory responses in those tumours and even in tumours located in a distant location in the mouse body. The researchers further demonstrated that this treatment approach has made tumours more responsive to treatment with immune checkpoint inhibitors.

This dual treatment significantly extended the survival of mice and reduced tumour growth in mouse models of melanoma, Lewis lung carcinoma, and colon adenocarcinoma.

Dr Hany Elsheikha, Associate Professor in the School of Veterinary Medicine and Science at the University of Nottingham, and one of the lead authors of the study, said: “The use of a mutant version of Toxoplasma gondii in the treatment of certain tumours in mice models has been previously reported. What makes this study different is the confirmation that intratumoural injection with mutant Toxoplasma gondii strain boosts antitumour immunity and the effectiveness of checkpoint inhibition therapy.

“These are significant findings and are relevant to future tumour therapy. The marked reduction in tumour size and the significant improvement in the survival of mice that received this novel combinational therapy is promising but should be interpreted with caution as further research is needed.”

Source: University of Nottingham

Categories : VaccinesTags :

UN Urges Group B Streptococcus Vaccine to Protect Babies

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Photo by William-Fortunato on Pexels

There is an urgent need for vaccines against Group B streptococcus, a major cause of preterm births, disability and infant mortality worldwide, according to a UN-backed report published on Wednesday.

Group B streptococcus (GBS) is a gram-positive bacteria that colonises the gastrointestinal and genitourinary tract. It can be transmitted in utero, is linked to around 150 000 infant deaths each year, more than half a million preterm births and significant long-term disability.

The report by the World Health Organization (WHO) and the London School of Hygiene & Tropical Medicine (LSHTM) updates 2017 estimates, and reveals that the global burden of GBS is far higher than was previously recognised.

“This new research shows that Group B strep is a major and underappreciated threat to newborn survival and wellbeing, bringing devastating impacts for so many families globally,” said Dr Phillipp Lambach, Medical Officer from WHO’s Immunization, Vaccines and Biologicals department.

The report is the first to quantify the major contribution of GBS to preterm births, and to neurological impairments such as cerebral palsy, hearing and vision loss, that can occur following infection.

Around 15% of all pregnant women worldwide, nearly 20 million annually, carry the GBS bacterium in their vagina, which can then spread to a foetus, or to newborns during labour. At present, GBS disease prevention in newborns is by administering antibiotic prophylaxis to women during labour, if the bacterium is detected during pregnancy.

However, significant health risks remain, as this intervention is unlikely to prevent most GBS-associated stillbirths, preterm births, or GBS disease that occurs later after birth.

“It is difficult to describe the breadth or depth of the grief when your child dies, or the accompanying guilt, and how it changes you, your family, and your relationships forever,” said Debbie Forwood, whose daughter Ada was stillborn after she developed a GBS infection.

Vaccine development urged
GBS burden is highest in low and middle-income countries, where screening and treatment are most challenging to implement, with regions such as sub-Saharan Africa having the highest rates of maternal GBS.
Now is the time for action, said Joy Lawn, an LSHTM Professor who contributed to the report.  While several candidate GBS vaccines are in development, none are yet available despite decades in the pipeline. The report calls for stepping up development of an effective GBS vaccine that could be administered to expectant mothers during routine pregnancy checkups.

The partners estimate more than 50 000 GBS-related deaths, and over 170 000 pre-term births, could be avoided if over 70 per cent of pregnant women were vaccinated.

Such protection could also be highly cost-effective, they added.  Net benefits from a year of maternal vaccinations could reach as high as $17 billion, accruing over several years, provided doses are affordably priced. For Ms. Forwood, this would be a bittersweet development.

“Only a GBS vaccine could have saved Ada.  When a vaccine can be widely rolled out, I will weep and scream with the unfairness that it came too late for her, and for all the other babies who are needlessly suffering and dying every year that it is delayed,” she said.

“But I will also weep with joy that in the future, many more will live, and their families will be saved from the living hell that is the death of a child.”

Source: UN News

Categories : NeurologyTags :

Scientists Discover New Type of Neuron in the Retina

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Source: Daniil Kuzelev on Unsplash

University of Utah scientists have discovered a new type of neuron in the retina, which will help fill in our understanding of how sensory information is relayed.

In the central nervous system a complex network of neurons communicate with each other to relay sensory and motor information. In this chain of communication, a type of neuron called interneurons serve as intermediaries . A research team led by Ning Tian, PhD, identified a previously unknown type of interneuron in the mammalian retina. Their findings were published in the journal PNAS.

This discovery is a major step forward for the field as scientists strive to build a better understanding of the central nervous system by identifying all classes of neurons and their connections.

“Based on its morphology, physiology, and genetic properties, this cell doesn’t fit into the five classes of retinal neurons first identified more than 100 years ago,” said Dr Tian. “We propose they might belong to a new retinal neuron class by themselves.”

The research team called their discovery the Campana cell after its shape, which resembles a hand bell. Campana cells relay visual signals from both types of light-sensing rod and cone photoreceptors in the retina, however their exact purpose is the subject of ongoing research. Experiments revealed that Campana cells remain activated for an unusually long time – as long as 30 seconds – in response to a 10 millisecond light flash stimulation.

“In the brain, persistent firing cells are believed to be involved in memory and learning,” said Dr Tian. “Since Campana cells have a similar behaviour, we theorise they could play a role in prompting a temporal ‘memory’ of a recent stimulation.”

Source: University of Utah

Categories : AgeingTags :

Inflammatory Markers Found in Socially Isolated Older Adults

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New research from the US has found that older adults who experienced social isolation had higher blood levels of interleukin-6 and C-reactive protein, two markers of inflammation that can have long-term negative impacts for the health of individuals as they age.

Social isolation is a risk factor for morbidity and mortality comparable to well-established risk factors including smoking, hypertension, and a sedentary lifestyle. The specific biological mechanisms that connect social isolation to morbidity and mortality remain unclear. 

The study, published in the Journal of the American Geriatrics Society, used data from the National Health and Aging Trends Study (NHATS), which included a nationally representative sample of 4648 Medicare beneficiaries aged 65 years and older. The researchers defined social isolation with a multi-domained typology that considers living arrangement, core discussion network, religious attendance, and social participation
The authors noted that clinical and social interventions that address social isolation among older adults may influence biological processes such as inflammation, as well as their potentially negative effects.

Credit: JAGS

“Our findings demonstrate an important association between social isolation and biological processes. This work is a step in the journey to disentangle the mechanisms by which social isolation leads to higher levels of morbidity and mortality,” said lead author Thomas K.M. Cudjoe, MD, MPH, of Johns Hopkins School of Medicine. “My hope is that investigators incorporate objective measures of social isolation and biological markers in future longitudinal studies so that we might continue to advance our understanding of these complex biopsychosocial interactions.”

Source: Wiley

Categories : Metabolic DisordersTags :

1 in 20 People with Diabetes Achieve Remission on Their Own

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In Scotland, about one in 20 people diagnosed with type 2 diabetes achieve remission from the disease, according to research appearing in PLOS Medicine. This suggests people are achieving remission outside of research trials and without bariatric surgery. Recognition of individuals in remission, following their progress, and understanding better the factors linked to remission could result in improved initiatives to help others.

In 2019 there were an estimated 463 million people with diabetes in the world, 90–95% of whom have type 2 diabetes. Ageing populations, growing obesity and sedentary lifestyles are increasing these numbers. The likelihood of achieving remission after 15% weight loss has been shown to be mainly determined by the duration of diabetes, with responders having better beta‐cell function at baseline.

Some people with type 2 diabetes have achieved remission after bariatric surgery, or after taking part in a research trial of a very low-calorie diet, but it is unknown how many people in the general population are in remission. Mireille Captieux at the University of Edinburgh and colleagues used a Scottish national register of people with type 2 diabetes to estimate the number of people in remission in 2019 and described the characteristics of those in remission and not in remission.

Of 162 316 patients aged > 30 who were eligible for the analysis, 7710 (5%) were in remission in 2019. Individuals in remission tend to have not previously taken glucose lowering medication; have lost weight since their diagnosis; be older; have lower blood sugar levels at diagnosis; or have had bariatric surgery. This finding helps to establish a baseline for future studies, and could also help clinicians identify patients with whom to discuss remission and weight loss.

Captieux added, “We have been able to show, for the first time, that 1 in 20 people in Scotland with type 2 diabetes achieve remission. This is higher than expected and indicates a need for updated guidelines to support clinicians in recognising and supporting these individuals.”

Source: EurekAlert!

Categories : COVIDTags :

Hopes Dashed for Ciclesonide as COVID Treatment

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Source: PIxabay/CC0

Despite high hopes, the first placebo controlled trial of inhaled steroids for COVID suggests that ciclesonide, an inhaled and nasal steroid drug commonly used for asthma and rhinitis, does not help young healthy people with COVID and respiratory symptoms improve earlier.

The study, published in the BMJ, was motivated by research showing that ciclesonide, which is safe, inexpensive and widely available, could decrease viral replication of SARS-Cov2 in mouse models of COVID. A randomised, double-blind, placebo-controlled trial of inhaled ciclesonide was designed to evaluate the resolution of symptoms in adults with COVID presenting with respiratory symptoms.

“Based on my experience treating asthma, I thought it made sense to see if it would decrease the lung inflammation in patients with COVID early in the disease, as lung disease has an important impact for patients and is a major effect of the virus,” explained Dr Nicole Ezer, the first and lead author of the study, who is a lung specialist and a researcher in the Translational Research in Respiratory Diseases Program at the RI-MUHC. “In addition, we felt it was important to study a drug for COVID that has a very good safety profile and could be used in high, middle and low-income countries safely to reduce respiratory symptoms. Access to affordable medications is very important to decrease disparities in health outcomes across the world.”

The importance of placebo control
From Sept. 15, 2020 to June 8, 2021, the study recruited 215 symptomatic adults and randomly assigned them to either inhaled and intranasal ciclesonide or inhaled and intranasal placebo for 14 days. Participants were asked to complete a survey online on the day of enrollment and on six other occasions until day 14, with a follow-up survey at day 29.

Based on the assumption that treatment would be most effective if given early in the disease process, participants were recruited within five days of a positive PCR test result for SARS-CoV-2 and symptom onset and received the treatment at home by commercial courier. No vaccinated participants were included in the trial.

No significant difference was seen between the intervention and control group. After seven days of treatment, 40% taking ciclesonide had no more fever and respiratory symptoms, vs 35% taking placebo. At day 14, these figures amounted to 66% in the ciclesonide group compared with 58% in the placebo group.

Those results are disappointing, especially since two recent open label studies had raised hopes in the scientific community that inhaled steroids could alleviate respiratory symptoms associated with COVID, and one study demonstrated efficacy of dexamethasone in admitted patients with COVID.

“The previously published studies had a major limitation: they were open label with no placebo. Other studies have shown that inhalers have a strong placebo effect,” explained the study’s senior author, Dr Emily McDonald, associate professor of medicine at McGill University. “Here’s a strong reminder that any study of a medication, in particular of inhalers, needs to be controlled with a placebo before we rush to recommend them.”

In spite of the study’s outcome, researchers still believe there is potential for the treatment of COVID with inhaled steroids.

“It’s still possible that inhaled steroids might be beneficial for older at-risk populations,” said Dr Ezer, who is also an assistant professor of medicine at McGill University. “We need more research focused on older adults and people who are high-risk, but those studies must have a placebo arm to make sure they aren’t coming to a false conclusion of benefit.”

Source: McGill University