Category: Diseases, Syndromes and Conditions

Categories : Diseases, Syndromes and Conditions VaccinesTags :

A New Way to Vaccinate Against Diarrhoeal Diseases: ‘Bribe’ the Bacteria

On By ModernMedia
Scanning electron micrograph image of E. Coli bacteria. Credit: NIH

Scientists have found that pairing specific diets with disease-causing bacteria can create lasting immunity in mice without the costs of developing sickness, revealing a new potential vaccination strategy. Their findings, published in Science Advances, may lead to new vaccines that could promote immunity for those with diarrhoeal diseases and possibly other infections.

The body takes one of two defence strategies against bacterial infections: kill the intruders or impair the intruders but keep them around. If the body chooses to impair the bacteria, then the disease can occur without the diarrhoea, but the infection can still be transmitted – also known as asymptomatic carriage.

“We discovered that immunisation against diarrhoeal infections is possible if we allow the bacteria to retain some of its disease-causing behaviour,” says senior author Professor Janelle Ayres at Salk Institute. “This insight could lead to the development of vaccines that could reduce symptoms and mortality, as well as protect against future infections.”

In 2018, Ayres’ lab looked at how dietary interventions can create an asymptomatic infection, which Ayres calls a cooperative, asymptomatic relationship between bacteria and host. They discovered that an iron-rich diet enabled mice to survive a normally lethal bacterial infection without ever developing signs of sickness or disease. The high-iron diet increased unabsorbed glucose in the mice’s intestines, which the bacteria could feast on. The excess glucose served as a ‘bribe’ for the bacteria, keeping them full and incentivised to not attack the host.

This process produced long-term asymptomatic infection with the bacteria, leading the researchers to believe that the adaptive immune system (which ‘remembers’ infections) may be involved.

“Being able to generate lasting immunity against bacteria like C. rodentium or E. coli has not been possible using established vaccination strategies. We wanted to figure out what mechanism was sustaining this lasting immunity, so we could use that mechanism to create an impactful solution to these diarrheal diseases,” says first author Grischa Chen, a former postdoctoral researcher in Ayres’ lab.

The researchers moved to figure out how the body suppresses infection symptoms, whether infection without symptoms can create long-term immunity, and whether that immunity is reproducible as a vaccination strategy.

The team compared mice with iron-rich and normal diets after C. rodentium infection to find whether the diet impacted symptomless infection. Immediately after infection, mice fed an iron-rich diet had no symptoms whereas mice fed a normal diet did have symptoms. All mice were then put on a normal diet to see whether the asymptomatic infection would last.

Mice without functional adaptive immune systems, regardless of whether they had ever been on an iron-rich diet, could not continue maintaining a cooperative relationship with the bacteria. Although the iron-rich diet suppressed symptoms immediately after infection, the adaptive immune system was required for lasting cooperation. Importantly, the mice with functional adaptive immune systems had the disease without any symptoms, with lasting immunity, as demonstrated by survival upon reinfection after a month.

Ayres and team concluded that an iron-rich diet alone can prevent bacteria from creating deadly symptoms in mice during active infection. But a functional adaptive immune system is required for immunity against future infection in the absence of dietary supplementation.

Some bacterial strains, if mutated enough, don’t cause symptoms. To test whether such bacteria could produce lasting immunity, the team repeated their iron-diet versus normal-diet experiment in mice, but this time using bacteria that could cause disease and bacteria that could not cause disease. They found that only mice that received disease-causing, unmutated bacteria were able to support immunity upon reinfection.

The scientists note that this is only a preliminary study and people shouldn’t consume large amounts of iron after reading it. They also hope their insights will provide a basis for future research in humans and the creation of a vaccination regiment that protects and prevents against diarrhoeal illness.

Source: Salk Institute

Categories : Diseases, Syndromes and ConditionsTags :

‘Indian Hedgehog’ – a Protein That Drives Chronic Kidney Disease

On By ModernMedia
Photo by Robina Weermeijer on Unsplash

Researchers studying mice to investigate scarring in kidneys and hearts have found that it is driven by a protein called Indian Hedgehog (IHH), which is produced and released by a subset of cells in aged and injured kidneys. They published their findings in the journal Science Translational Medicine.  

The researchers believe that IHH could become a potential target for therapies to treat chronic kidney disease (CKD) – a condition that affects 10% of the world’s population.  

Risk factor

CKD is a term used to cover any form of kidney disease that continues for more than a few months. It can affect people of any age, but older people are more likely to experience some level of CKD.  

While CKD primarily causes damage to kidneys, it is also a major risk factor for accelerated cardiovascular disease and premature death.  

Progressive fibrosis – scarring of the kidneys – is a common feature in all CKD, but the mechanism underlying this connection is not fully understood.  

Reduced scarring

A team from the University of Edinburgh identified a subset of epithelial cells that produce IHH and are only present within aged or injured mouse kidneys. They showed that these cells produced IHH in response to being activated by the protein TNF – a well-recognised driver of inflammation.   

When blocking the actions of TNF or IHH in mouse models of kidney scarring, the team found that scar production in the kidney was reduced and kidney function was also better preserved. Increased levels of scarring in the heart also returned to normal levels.   

Blocking pathway

In humans, the team showed that circulating IHH levels were significantly raised in patients with CKD. Patients with cardiovascular disease also had higher levels of IHH than those without cardiac problems. 

The findings offer hope that blocking the TNF/IHH signalling pathway could improve both kidney and heart fibrosis problems – the leading cause of morbidity and mortality in patients with CKD. 

There is a major unmet need for better treatments to halt the progressive kidney scarring and cardiovascular problems which affect so many patients with CKD. I’m excited at the potential of this work, and the new insights to be gained into the role of IHH as a major driver of multi-organ fibrosis, which we hope can be a first step on the road towards better treatments for patients.

Dr David Ferenbach, MRC Senior Clinical Fellow at the University of Edinburgh

Source: University of Edinburgh

Categories : Cardiovascular Disease Diseases, Syndromes and ConditionsTags :

Even Modest Drop in Kidney Function is Linked to Greater Health Risks

On By ModernMedia
Photo by Robina Weermeijer on Unsplash

A Canadian study of more than 8 million adults suggests that even a modest loss of kidney function is associated with increased health risks. The study, published in The BMJ, could lead to better approaches to prevent chronic kidney disease and related conditions, particularly in younger adults.

“The dogma is that healthy, young adults don’t need to worry about kidney function unless it drops to around 50% of the normal level, but our research suggests that even a more modest 20–30% drop may have consequences and we may want to have earlier conversations about prevention and monitoring,” explained senior author Dr Manish Sood at the University of Ottawa.

The research team used health records from 2008 to 2021 for every Ontario, Canada adult aged 18–65 who had at least one blood test for kidney function, but no history of kidney disease. They found that 18% of those in the 18–39 age group had kidney function that was modestly below normal levels, but not low enough to be diagnosed with chronic kidney disease. Individuals in this ‘grey zone’ faced a modestly increased risk of kidney failure, death and cardiovascular events.

For example, in young adults (age 18–39), a 20–30% loss in kidney function was associated with a 1.4-fold increase in death, 1.3-fold increase in a cardiac event and a 6-fold increase in the risk of kidney failure. The absolute risk of any of these events was still low at less than 2 per 1000.

“Thankfully, the absolute risk for any one individual with kidney function in this grey zone is low, but when we look at the whole population, the impact could be quite significant,” said co-senior author Dr Greg Knoll, senior scientist, nephrologist and Head of the Department of Medicine at The Ottawa Hospital and the University of Ottawa. “We need further research to confirm these findings and then see if we can reduce the risk through lifestyle modification.”

While the blood creatine test for kidney function is relatively inexpensive and readily available, the researchers are not suggesting routine testing for all individuals at this time. However, if an individual has had a kidney test that shows a modest reduction in function, it could prompt consulting health care provider. All individuals can also reduce their risk of kidney disease by eating a healthy diet with lower salt, exercising regularly and limiting alcohol intake.

Dr. Sood and his colleagues previously developed the Project BigLife Chronic Kidney Disease calculator to help individuals calculate their kidney disease risk and see the impact of lifestyle changes. The calculator will continue to be refined as new research arises.  

Source: EurekAlert!

Categories : Diseases, Syndromes and Conditions GeneticsTags :

Food Poisoning Bacteria Species Swap Pathogenic Genes

On By ModernMedia
Escherichia coli. Image by CDC on Unsplash

Researchers have identified how pathogenic genes in some Providencia spp., which have gained attention as causes of food poisoning as well as enterohaemorrhagic Escherichia coli. O157 and Salmonella, are transferred within bacterial cells. Their findings are expected to provide new insights into the identification of infection routes of Providencia spp. and the establishment of preventive methods for food poisoning.

Recently, Providencia spp. which have been detected in patients with gastroenteritis, and similar to enterohemorrhagic Escherichia coli. O157 and Salmonella spp., have been attracting attention as causative agents of food poisoning. For children with low immunity, food poisoning can be lethal as it causes severe symptoms such as diarrhoea and dehydration, so clarifying the source of infection and pathogenic factors of Providencia spp., and establishing preventive methods are urgent issues worldwide.

A joint research group led by Professor Shinji Yamasaki, Dr Sharda Prasad Awasthi, a Specially Appointed Lecturer, and graduate student Jayedul Hassan from the Graduate School of Veterinary Science, Osaka Metropolitan University, determined how the pathogenic genes in some Providencia spp. such as Providencia alcalifaciens and Providencia rustigianii are transferred within bacterial cells of genus Providencia. The group has also elucidated that the pathogenic genes of Providencia rustigianii are also transferred to other bacterial cells belonging to Enterobacteriaceae.

Professor Yamasaki concluded, “This achievement is expected to provide new insights into the identification of infection routes of Providencia spp. and the establishment of preventive methods for food poisoning.”

Source: Osaka Metropolitan University

Categories : Diseases, Syndromes and Conditions PaediatricsTags :

18th & 19th Century Grannies Protected Their Grandchildren from Infectious Diseases

On By ModernMedia
Photo by CDC on Unsplash

While grandmothers today have a popular image of spoiling their grandchildren with treats, in premodern times they also acted as healthcare providers. To find out more, University of Turku researchers looked at historical data on childhood mortality from infectious diseases in the 18th and 19th century in Finland. The study, which is published in the journal Proceedings of the Royal Society B, found that grandmothers decreased all-cause and cause-specific mortality of children.

In historical and in several contemporary societies, children with living grandmothers are more likely to survive into adulthood, but the mechanism behind this effect remains poorly known.

As childhood infections have been a leading cause of death in children under the age of 5 years, the researchers aimed to investigate whether the effect of grandmothers on childhood survival was related to providing knowledge in childcare, particularly during critical times such as epidemics. One way for grandmothers to do so could be by encouraging vaccine uptake or earlier vaccination against childhood infections, as has been observed in some contemporary populations.

Researchers first studied the effects of grandmothers on children’s cause-specific mortality, using historical records of five causes of death: smallpox, measles, pulmonary infections, diarrhoeal deaths, and accidents. The large multigenerational dataset of pre-industrial Finnish families included 9705 individuals from 12 parishes across Finland, where the survival of individuals until the of age 15 years was monitored from 1761 to 1900. In the second part of the study, the researchers determined whether increased survival against the childhood infection smallpox was mediated by vaccination. To this end, they used 1594 vaccination records from two rural parishes and matched them to their individual family histories.

The results show that grandmothers decreased all-cause mortality, an effect which was mediated through improved survival from smallpox, pulmonary and diarrhoeal infections, but not from measles or accidents. However, the researchers found no evidence of increased or earlier vaccination between children with or without grandmothers.

“Our results show that the grandmother’s presence protected against some childhood infections, which could indicate that in historical Finnish society, the assistance provided by grandmothers in childcare was likely an important factor in ensuring the survival of children,” says study lead author, Doctoral Researcher Susanna Ukonaho.

Grandmothers in contemporary societies

Although grandmother care provided health benefits in many historical societies, these benefits may no longer be relevant in contemporary societies. The progress in healthcare during the 20th century especially in high-income countries likely decreased the role of grandmothers. However, some studies indicate that grandmothers improve childhood survival in several contemporary middle- and low-income countries.

“The type of benefits that grandmothers provide may vary depending on cultural contexts and individual circumstances. Even though in many societies grandmothers are no longer essential for childhood survival, their efforts in childcare remain valuable for the well-being of the whole family,” says Ukonaho.

Source: University of Turku

Categories : Diseases, Syndromes and ConditionsTags :

Oestriol Shown to Reverse Cortex Damage from MS in Mouse Model

On By ModernMedia
Source: Pixabay CC0

Treating a mouse model of multiple sclerosis with the pregnancy hormone oestriol reversed the breakdown of myelin in the brain’s cortex, a key region affected in multiple sclerosis, according to a new UCLA Health study.

In multiple sclerosis, inflammation spurs the immune system to strip away the protective myelin coating around nerve fibres in the brain’s cortex, hampering electrical signals sent and received by the brain. Atrophy of the cortex in MS patients is associated with permanent worsening of disability, such as cognitive decline, visual impairment, weakness and sensory loss.

No currently available treatments for MS can repair damage to myelin. Instead, these treatments target inflammation to reduce symptom flare-ups and new nerve tissue scarring. Previous UCLA-led research found that oestriol, a type of oestrogen hormone produced in pregnancy, reduced brain atrophy and improved cognitive function in MS patients.

In the new study, researchers treated a mouse model of MS with oestriol and found that it prevented brain atrophy and induced remyelination in the cortex, indicating that the treatment can repair damage caused by MS, rather than just slow the destruction of myelin.

This is the first study to identify a treatment that could repair myelin in the cortex, undoing some of the damage caused by MS.

Source: University of California – Los Angeles Health Sciences

Categories : Diseases, Syndromes and Conditions Injury & TraumaTags :

Autistic Adults Have Higher Risks of Injury and Disease

On By ModernMedia
Photo by Andrew Neel on Unsplash

A large-scale registry study found that older autistic adults have a significantly higher risk of injury, especially self-inflicted, and physical conditions such as type 2 diabetes, anaemia, heart failure and COPD. The findings were published in The Lancet Healthy Longevity.

“We found an increased disease burden in middle-aged and older autistic adults, both men and women, irrespective of the presence of intellectual disability,” says Shengxin Liu, doctoral student at Karolinska Institutet. “Our findings point up the need to improve the support and care of older autistic adults.”

In the population-based study, the KI researchers linked different national registers and compared the risk for five types of injury and 39 age-related physical conditions in people over the age of 45. Of the four million-plus people born between 1932 and 1967, 1930 women and 3361 men had an autism diagnosis. For each physical condition, they evaluated the 25-year cumulative incidence and the relative risk in autistic people compared with non-autistic people of the same sex and age.

Seven-fold risk of self-harm

Autistic people had a higher risk of four of five studied injures, for which self-harm accounted for the greatest risk increase, followed by poisoning, falls and other physical injuries.

“The risk of self-harm was worryingly high, a full seven times higher than in non-autistic people,” says Liu. “Reasons behind this remain largely unknown. One possible contributing factor could be mental health conditions that commonly co-occur with autism, such as anxiety and depression.”

The researchers also found a risk increase for 15 physical conditions. For example, autistic people had three times the risk of anaemia and glucose dysregulation and almost double the risk of heart failure, type 2 diabetes, and COPD (chronic obstructive pulmonary disease).

Multiple contributory factors

“We now need to find out the cause of these associations and how they are affected by factors such as biology, age when diagnosed with autism, psychotropic treatment and psychosocial environment,” says the study’s last author Mark Taylor, senior researcher at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet. “But most importantly, researchers, health services and policymakers need to cooperate to make sure that older autistic adults have a better quality of life.”

Since this was an observational study, no causal relationships can be ascertained, and the researchers were not able to take into account variables such as socioeconomic status. Furthermore, given that the study used Swedish registers, it is difficult to make generalisations to other countries.

Source: Karolinska Institutet

Categories : Diseases, Syndromes and ConditionsTags :

How the Influenza Virus Hijacks Our Cells’ Mechanisms

On By ModernMedia
Photo by Andrea Piacquadio on Unsplash

Influenza epidemics, caused by influenza A or B viruses, result in acute respiratory infection. New research published in published in the journal PNAS has identified how the influenza A virus manages to penetrate cells to infect them. By attaching itself to a receptor on the cell surface, it hijacks the iron transport mechanism to start its infection cycle. By blocking the receptor involved, the researchers were also able to significantly reduce its ability to invade cells. These results highlight a vulnerability that could be exploited to combat the virus.

Influenza viruses represent a major risk to human and animal health. Their potential for mutation makes them particularly elusive. ”We already knew that the influenza A virus binds to sugar structures on the cell surface, then rolls along the cell surface until it finds a suitable entry point into the host cell. However, we did not know which proteins on the host cell surface marked this entry point, and how they favoured the entry of the virus,” explains study leader Mirco Schmolke, Associate Professor at University of Geneva (UNIGE).

A receptor as a key to infection

The scientists first identified cell surface proteins present in the vicinity of the viral haemagglutinin, the protein used by the influenza A virus to enter the cell. One of these proteins stood out: transferrin receptor 1. This acts as a revolving door transporting iron molecules into the cell, which are essential for many physiological functions.

“The influenza virus takes advantage of the continuous recycling of the transferrin receptor 1 to enter the cell and infect it,” explains first author Béryl Mazel-Sanchez, a former post-doctoral researcher in Mirco Schmolke’s lab. “To confirm our discovery, we genetically engineered human lung cells to remove the transferrin receptor 1, or on the contrary to overexpress it. By deleting it in cells normally susceptible to infection, we prevented influenza A from entering. Conversely, by overexpressing it in cells normally resistant to infection, we made them easier to infect.”

Inhibiting this mechanism

The research team then succeeded in reproducing this mechanism by inhibiting the transferrinreceptor 1 using a chemical molecule. ”We tested it successfully on human lung cells, on human lung tissue samples and on mice with several viral strains,” says Béryl Mazel-Sanchez. ”In the presence of this inhibitor, the virus replicated much less. However, in view of its potentially oncogenic characteristics, this product cannot be used to treat humans.” On the other hand, anti-cancer therapies based on the inhibition of the transferrin receptor are under development and could also be interesting in this context.

”Our discovery was made possible thanks to the excellent collaboration within the Faculty of Medicine as well as with the University Hospitals of Geneva (HUG) and the Swiss Institute of Bioinformatics (SIB),” the authors add. In addition to the transferrin receptor 1, scientists have identified some 30 other proteins whose role in the influenza A entry process remains to be deciphered. It is indeed likely that the virus uses a combination involving other receptors. ”Although we are still far from a clinical application, blocking the transferrin receptor 1 could become a promising strategy for treating influenza virus infections in humans and potentially in animals.”

Source: Université de Genève

Categories : Diseases, Syndromes and ConditionsTags :

Nonalcoholic Fatty Liver Disease Comes with an Increased Infection Risk

On By ModernMedia
Source: CC0

A Swedish study of more than 12 000 patients with nonalcoholic fatty liver disease (NAFLD) revealed a significantly increased risk of severe infections requiring hospital admission. The study was published in Clinical Gastroenterology and Hepatology.

NAFLD is considered a manifestation of the metabolic syndrome in the liver and with the global rise in obesity, NAFLD has emerged as the most common chronic liver disease affecting around one quarter of all adults worldwide. Being such a wide-spread disease, it has also become the fastest growing cause of end-stage liver disease, primary liver cancer and liver transplantation. In recent years, NAFLD is increasingly viewed as a multifaceted disease affecting multiple organ systems.

In the ESPRESSO study, involving 12 133 individuals with biopsy-proven NAFLD, and 57 516 matched controls from the general population, NAFLD was associated with a 71% higher risk for severe infections requiring hospital admission. The researchers found that individuals with NAFLD exhibited the same spectrum of infection sites as compared with the general population – with respiratory and urogenital tract infections being the two most common sites of infection.

“Our work is important as the first nationwide study assessing the risk of infections in individuals diagnosed with NAFLD”, says lead author Dr Fahim Ebrahimi, MD, MSc, postdoctoral researcher at Karolinska Institutet and gastroenterologist at Clarunis University Center for Gastrointestinal and Liver Diseases in Basel, Switzerland. “Our findings highlight the importance of NAFLD as a multisystem disorder that increases the risk of infections independent from other underlying risk factors such as diabetes mellitus.”

Risk differences for infections

The researchers were intrigued by previous experimental studies that suggested that NAFLD is associated with impaired function of several immune cells which may lead to higher susceptibility towards various viral, bacterial, and fungal infections. “The liver plays a significant role in the human immune system with immune cells, such as macrophages (Kupffer cells) and lymphocytes, constituting up to 20% of all liver cells”, adds Dr. Ebrahimi. “We were surprised to find that the risk of severe infections was increased even in people with simple fatty liver disease without evidence of any liver inflammation or fibrosis. However, when individuals had evidence of the inflammatory subtype nonalcoholic steatohepatitis (NASH), or had developed fibrosis, they were at even higher risks with the highest risks among those with cirrhosis.”

“The absolute risk difference at 20 years after NAFLD diagnosis was 17.3%, equal to one extra severe infection in every 6 patients with NAFLD, therefore, our findings underline the importance of early diagnosis and treatment to reverse the disease at all stages”, says corresponding author Jonas F Ludvigsson, paediatrician at Örebro University Hospital, and professor at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet.

“To date, clinical guidelines on NAFLD have not yet included specific recommendations for preventing and managing infections”, says Dr Ebrahimi. “Based on our results, prevention of infections should become one of the main public health efforts to tackle NAFLD associated morbidities.”

Source: Karolinksa Insitutet

Categories : Diseases, Syndromes and ConditionsTags :

Gauteng Cholera Deaths Rise as Government Sets up Field Hospital

On By ModernMedia

As of Sunday, reports indicate that 23 people have died so far in the recent cholera outbreak in Hammanskraal, a direct result of the town’s neglected water sanitation infrastructure. A further 48 have been hospitalised, with six emergency field tents being set up to prop up the overburdened Jubilee Hospital, which has seen 215 patients since 19 May, as reported in the most recent Gauteng Department of Health bulletin.

The temporary field hospital has been set up to immediately attend to cases of dehydration, supplying oral rehydration solution (IRS) as well as intravenous fluids. More critical patients are taken to Tshwane hospitals.

The Gauteng Department of Health also notes that as of Friday, 27 of the 75 confirmed cholera cases had recovered and been discharged. The Gauteng Department of Education has said that it will intensify efforts to supply schools in Hammanskraal with clean drinking water.

South Africa’s most serious outbreak of cholera in recent history was from November 2008, when a massive cholera outbreak occurred in Zimbabwe and spread to South Africa. Within the first 5 months of the outbreak, more than 73 000 cases and 3500 deaths (case fatality rate of >4.7%) had been reported, and it spread to South Africa through Musina. Between 15 November 2008 and 30 April 2009, a total of 12 706 cases of cholera were reported by the National Department of Health. Of the total number of cases, 1114 (9.0%) were laboratory-confirmed cases, and 65 deaths (case fatality rate of 0.5%) were recorded. In this outbreak, microbial analysis published in the Journal of Infectious Diseases found the emergence of antimicrobial resistance in Vibrio cholerae 01 strains.

The National Institute of Communicable Diseases has posted guidelines [PDF] for the management of suspected cholera chases.