Tag: 8/12/21

Categories : Cancer Obstetrics & GynaecologyTags :

After a Pregnancy, Natural Killer Cells Suppress Tumours

On By ModernMedia
Source: Anna Hecker on Unsplash

After a pregnancy, breast cells call in Natural Killer T (NKT) cells as reinforcements to prevent tumours from arising, according to a study published in Cell Reports. This finding from the lab of Associate Professor Camila dos Santos at Cold Spring Harbor Laboratory (CSHL) illuminates a new way in which pregnancy reduces the risk of breast cancer.

Two lines of defence exist in the immune system: the innate response, which involves immune cells that attack any foreign molecule they encounter, and the adaptive response, which consists of immune cells that respond specifically to calls for help. NKT cells are a unique subset of cells that are present throughout the body which can participate in both responses. 

CSHL graduate student Amritha Varshini Hanasoge Somasundara said that after a pregnancy: “There is an increase in this specific [NKT] cell type, and only in the mammary gland. We don’t see the expansion everywhere else in the body, even though NKT cells are present everywhere else in the body.”

The team sought to uncover the reason behind the larger number of NKT cells were doing in the breast tissue. Hanasoge discovered that in mice, breast epithelial cells, which line lactation ducts, produce a specific protein called CD1d after pregnancy. If the cells did not present CD1d, no increase in NKT cells was seen in the tissue; the epithelial cells became cancerous and grew into tumours. Hanasoge and dos Santos think that CD1d molecules are calling in NKT cells to monitor the epithelial cells in the breast tissue after pregnancy. If they become cancerous, the NKT cells can quickly kill them to prevent tumour growth.

The team’s findings establish a novel link between pregnancy and the immune system in preventing breast cancer. They want to know how these findings can be translated into humans and what other factors may influence an abundance of NKT cells in breast tissue, such as aging and menopause, which are both associated with increased breast cancer risk.

Discussing the results, Associate Professor dos Santos said: “One of the hypotheses that we are working on now is: do pregnancies later on in life bring in the same expansion of the same subtypes of immune cells as pregnancies that took place early in life?”

Source: Cold Spring Harbor Laboratory

Categories : Immune SystemTags :

How Immune Cells Fight Infection Using Body Fat

On By ModernMedia
T lymphocyte. Credit: NIH/NIAID

A new study from the University of East Anglia and Quadram Institute sheds light on how our immune cells make use of body fat to fight infection. The research, published today in Nature Communications, could lead to new approaches to treating people with bacterial infections.

The work could one day help treat infections in vulnerable and older people, the researchers said. The team studied Salmonella bacteria and tracked fatty acid movement and consumption in live stem cells. They then examined the immune response to Salmonella bacterial infection, by analysing liver damage.

They uncovered how blood stem cells respond to infection, by acquiring high energy fatty acids from the body’s fat stores. In the bone marrow where blood stem cells are resident, infection signals drive adipocytes to release their fat stores as fatty acids into the blood.

And they identified that these high energy fatty acids are then taken up by blood stem cells, effectively feeding the stem cells and enabling them to make millions of Salmonella-fighting white blood cells. The researchers also identified the mechanism by which the fatty acids are transferred and discusses the potential impact this new knowledge could have on future treatment of infection.

Dr Stuart Rushworth, from UEA’s Norwich Medical School, said: “Our results provide insight into how the blood and immune system is able to respond to infection.

“Fighting infection takes a lot of energy and fat stores are huge energy deposits, which provide the fuel for the blood stem cells to power up the immune response.

“Working out the mechanism through which this ‘fuel boost’ works gives us new ideas on how to strengthen the body’s fight against infection in the future.”

Dr Naiara Beraza, from the Quadram institute, said: “Our results allow us to understand how our immune system uses fat to fuel the response to infection. Defining these mechanisms will enable us to develop new therapeutics to treat infections in the liver.”

Source: University of East Anglia

Categories : Cardiovascular Disease PaediatricsTags :

Cholesterol Screening Recommended for Children with Autism

On By ModernMedia
Phot by Ben Wicks on Unsplash

Physicians have recommended that children with autism spectrum disorder (ASD) receive screening for abnormally high or low cholesterol levels at least once during their childhood, since ASD is a risk factor for cardiovascular disease in both children and adults.

The recommendation stemmed from a recent study, published in Translational Psychiatry, that found reduced levels of high density lipoprotein cholesterol (HDL-C) in individuals from families with two or more children with ASD. Additionally, they found reduced or elevated levels of other lipids, apolipoprotein A1 (ApoA1) and apolipoprotein B (ApoB). Individuals with low HDL-C levels or ApoA1 levels had lower adaptive functioning than other individuals with ASD.

“This latest research is part of our ongoing work to understand some of the co-occurring conditions with ASD,” said Elaine Tierney, MD, a child and adolescent psychiatrist with Kennedy Krieger Institute. “Our work indicates that lipids are abnormal in many individuals with ASD. Our findings, in addition to studies that show an increase in heart disease in individuals with ASD, lead us to recommend that children with ASD be screened for abnormal total and HDL cholesterol levels. We hope our work underscores the importance of cholesterol screening and raises awareness for families in the ASD community.”

Previously, Dr Tierney and colleagues identified that Smith-Lemli-Opitz Syndrome (SLOS), a genetic condition of impaired cholesterol biosynthesis, is associated with autism. This led to a recommendation that all children with ASD be screened for SLOS if they exhibit some of its characteristics, such as slow growth, microcephaly, mental retardation and other birth defects, although the severity of this rare disease can vary.

Source: Kennedy Krieger Institute

Categories : Addiction Mental HealthTags :

Use of Electronic Devices Linked to Depression and Anxiety

On By ModernMedia
Photo by Tracy le Blanc from Pexels
Photo by Tracy le Blanc from Pexels

In a study published in Addiction Biology, researchers uncovered significant associations between use of electronic devices and signs of depression and anxiety, as well as cigarette smoking and alcohol drinking. The team also found certain genetic variants that were linked with these traits.

A review of studies on smartphone addiction found that anxiety and depression were commonly mediated mental health problems. A wide range of physical health sequelae was also associated with smartphone addiction. Furthermore, there was an association between smartphone addiction and neurological disorders.

The study included data on hundreds of thousands of individuals from the UK Biobank. Three indicators of use of electronic devices were included in the study: TV watching, computer using, and computer playing.

Their findings suggested that electronic devices use was associated with common mental traits and provided new clues for understanding genetic architecture of mental traits.

The authors wrote that the study’s findings suggest that reducing time spent using electronic devices may help reduce mental health burdens. 

Source: Wiley

Categories : COVID HospitalsTags : 1 Comment

Netcare Reports Less Severe COVID in Fourth Wave

On By ModernMedia
Image by Quicknews

In a news release by Netcare, the company’s CEO Dr Richard Friedland said that more than three weeks after the discovery of the new Omicron variant in South Africa, data across its hospitals and primary healthcare facilities are demonstrating important early trends.

“Having personally seen many of our patients across our Gauteng hospitals, their symptoms are far milder than anything we experienced during the first three waves,” commented Dr Friedland.

“Approximately 90% of COVID patients currently in our hospitals require no form of oxygen therapy and are considered incidental cases. While we fully recognise that it is still early days, if this trend continues, it would appear that with a few exceptions of those requiring tertiary care, the fourth wave can be adequately treated at a primary care level.”

Rates of community transmission and hospital admission possibly decoupled
During the first three waves, the rate of hospital admissions rose in tandem with the rate of community transmission (the number of people testing positive). Dr Friedland noted that, in the first three waves of the pandemic, Netcare treated 126 000 COVID patients across its 49 acute hospitals, of which 55 000 (44%) patients required admission and 26% of these patients were treated in High Care and Intensive Care (ICU). Significantly, all COVID patients admitted were sick and required some form of oxygen therapy. The high admission rate, as well as the high percentage of patients requiring ICU or High Care indicates the severity of cases during the first three waves.

“As of today we have 337 COVID positive patients admitted (72% in the Gauteng area and 18% in KwaZulu-Natal). Of these patients approximately 10% (33 patients) are on some form of oxygenation versus 100% in the first three waves. Eight of these patients (2%) are being ventilated and of these, two are primary trauma cases that are also COVID positive.”

Netcare’s policy is to test all patients for COVID before or on admission. Patients admitted for other primary diagnoses or surgical procedures who test positive for COVID] but do not require any form of oxygenation are considered to be incidental COVID cases, which currently accounts for 90% of COVID cases now in Netcare hospitals.

“During the first three waves, when the overall community positivity rate breached 26% across South Africa, we were inundated with COVID admissions to hospital. Within Netcare we had over 2000 COVID patients in hospitals during the first wave, over 2 250 patients in hospital during the second wave and over 3000 patients in hospital during the third wave. At present the 337 patients represent a fraction compared to previous waves,” said Dr Friedland.

“The very rapid rise in community transmission as compared to previous waves may partially explain this relatively low hospital admission rate. However, there does appear to be a decoupling in terms of the rate of hospital admissions at this early stage in the evolution of the fourth wave,” suggested Dr Friedland.

Majority of patients unvaccinated
Dr Friedland added that of a total of 800 COVID positive patients that were admitted since 15 November, 75% of patients were unvaccinated. Netcare has seen seven deaths over this period in this group of patients, of which four may be ascribed to COVID. These four patients were 58 to 91 years of age and had significant co-morbidities. Of these patients, three were not vaccinated.

Dr Friedland observed that COVID patients admitted since 15 November are on average younger than those seen during the first three waves. Over 71% are under 50, with an average age of 38.5. This compares to only 40% below 50 in the first three waves, with an average age of 54.

Virtually all patients have presented with mild to moderate flu-like symptoms, including a blocked or runny nose, headache and a scratchy or sore throat and have been treated symptomatically.

Dr Friedland reiterated that the best way to support South Africa remains to take COVID extremely seriously and to be as cautious as ever.