Eating almonds, walnuts may help fight colon cancer: study

Washington DC, Jun 29: Young children with narrow retinal artery diameters were more likely to develop higher blood pressure, and children with higher blood pressure levels were more likely to develop retinal microvascular impairment during early childhood, according to a new study.

The first study to show this connection in children was published today in Hypertension, an American Heart Association journal.

High blood pressure, the main risk factor for the development of cardiovascular disease (CVD), can manifest as early as childhood, and the prevalence of high blood pressure among children continues to rise. In previous studies, analysis of blood vessels in the retina has shown promise as a predictor of CVD risk among adults. In the study titled, "Retinal Vessel Diameters and Blood Pressure Progression in Children," researchers sought to predict the development of high blood pressure in children over four years based on retinal blood vessel measurements.

"Hypertension continues as the main risk factor for the development of cardiovascular diseases and mortality," says Henner Hanssen, M.D., the study's lead author and a professor in the department of sport, exercise and health at the University of Basel in Switzerland. 

"Primary prevention strategies are needed to focus on screening retinal microvascular health and blood pressure in young children in order to identify those at increased risk of developing hypertension. The earlier we can provide treatment and implement lifestyle changes to reduce hypertension, the greater the benefit for these children."

Researchers screened 262 children ages six to eight from 26 schools in Basel, Switzerland, in 2014, for baseline blood pressure and retinal arterial measurements. Both measures were taken again in 2018. Blood pressure measurements at both baseline and follow-up were performed in a sitting position after a minimum of five minutes of rest and were categorized based on the American Academy of Pediatrics' blood pressure guidelines. These guidelines utilize the same measurements as the American Heart Association/American College of Cardiology 2017 Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults.

Results from the analysis indicate: children with narrower retinal vessel diameters at baseline developed higher systolic blood pressure at follow-up; retinal vessel diameters could explain 29 -31 per cent of the changes in systolic blood pressure progression between 2014 and 2018; children with higher blood pressure levels at baseline developed significantly narrower arteriolar diameters at follow-up, depending on weight and cardiorespiratory fitness; and initial blood pressure measures explained 66-69 per cent of the change in retinal arteriolar diameter from baseline to follow-up.

"Early childhood assessments of retinal microvascular health and blood pressure monitoring can improve cardiovascular risk classification. Timely primary prevention strategies for children at risk of developing hypertension could potentially counteract its growing burden among both children and adults," said Hanssen.

Researchers noted limitations of their study include that they could not confirm blood pressure measurements over a single 24-hour period, so they would not account for "white coat" hypertension, a condition where patients have high blood pressure readings when measured in a medical setting.

Developmental stage including puberty status of each child was not accounted for in the study, as well as genetic factors or birth weight - variables that could impact blood pressure development and microvascular health.

In addition, reference values for appropriate retinal vessel diameters in children do not currently exist, so future studies are needed to determine age-related normal values during childhood.

Scientists have designed a “catch and kill” air filter which they say can trap the novel coronavirus and neutralise it instantly, an invention that may reduce the spread of COVID-19 in closed spaces such as schools, hospitals and health care facilities, as well as public transit environments like airplanes.

According to the study, published in the journal Materials Today Physics, the device killed 99.8 per cent of the novel coronavirus, SARS-CoV-2, in a single pass through its filter. It said the device, made from commercially available nickel foam heated to 200 degrees Celsius, also killed 99.9 per cent of the spores of the deadly bacterium Bacillus anthracis which causes the anthrax disease.

“This filter could be useful in airports and in airplanes, in office buildings, schools, and cruise ships to stop the spread of COVID-19,” said Zhifeng Ren, a co-author of the study from the University of Houston (UH) in the US.

“Its ability to help control the spread of the virus could be very useful for society,” Ren added.

The researchers said they are also developing a desk-top model for the device which is capable of purifying the air in an office worker’s immediate surroundings. According to the scientists, since the virus can remain in the air for about three hours, a filter that could remove it quickly was a viable plan, and with businesses reopening across the world, they believe controlling the spread in air conditioned spaces was urgent.

The study noted that the novel coronavirus cannot survive temperatures above 70 degrees Celsius, so by making the filter temperature far hotter — about 200 degree Celsius, the researchers said they were able to kill the virus almost instantly.

Ren said the nickel foam met several key requirements. “It is porous, allowing the flow of air, and electrically conductive, which allowed it to be heated. It is also flexible,” the researchers noted in a statement.But they added that nickel foam also had low resistivity, making it difficult to raise the temperature high enough to quickly kill the virus.

The researchers said they solved this problem by folding the foam, connecting multiple compartments with electrical wires to increase the resistance high enough to raise the temperature as high as 250 degrees Celsius. By making the filter electrically heated, rather than heating it from an external source, they said the the amount of heat that escaped from the filter is minimised, allowing air conditioning to function with very low strain.

When the scientists built and tested a prototype for the relationship between voltage/current and temperature, they said it satisfies the requirements for conventional heating, ventilation, and air conditioning (HVAC) systems, and could kill the coronavirus.

“This novel biodefense indoor air protection technology offers the first-in-line prevention against environmentally mediated transmission of airborne SARS-CoV-2, and will be on the forefront of technologies available to combat the current pandemic and any future airborne biothreats in indoor environments,” said Faisal Cheema, another co-author of the study from UH.

The researchers have called for a phased roll-out of the device, “beginning with high-priority venues, where essential workers are at elevated risk of exposure.” They believe the novel device will both improve safety for frontline workers in essential industries and allow nonessential workers to return to public work spaces.

COVID-19 mostly kills through an overreaction of the immune system, whose function is precisely to fight infections, say scientists who have decoded the mechanisms, symptoms, and diagnosis of the disease caused by the SARS-Cov-2 coronavirus.

In a study published in the journal Frontiers in Public Health, the researchers explained step-by-step how the virus infects the airways, multiplies inside cells, and in severe cases causes the immune defences to overshoot with a "cytokine storm".

This storm is an over-activation of white blood cells, which release too-great amounts of cytokines -- inflammation-stimulating molecules --into the blood, they said.

"Similar to what happens after infection with SARS and MERS, data show that patients with severe COVID-19 may have a cytokine storm syndrome," said study author Daishun Liu, Professor at Zunyi Medical University in China.

"The rapidly increased cytokines attract an excess of immune cells such as lymphocytes and neutrophils, resulting in an infiltration of these cells into lung tissue and thus cause lung injury," Liu said.

The researchers explained that the cytokine storm ultimately causes high fever, excessive leakiness of blood vessels, and blood clotting inside the body.

It also causes extremely low blood pressure, lack of oxygen and excess acidity of the blood, and build-up of fluids in the lungs, they said.

The researchers noted that white blood cells are misdirected to attack and inflame even healthy tissue, leading to failure of the lungs, heart, liver, intestines, kidneys, and genitals.

This multiple organ dysfunction syndrome (MODS) may worsen and shutdown the lungs, a condition called acute respiratory distress syndrome, (ARDS), they said.

This, the researchers explained, happens due to the formation of a so-called hyaline membrane -- composed of debris of proteins and dead cells -- lining the lungs, which makes absorption of oxygen difficult.

Most deaths due to COVID-19 are therefore due to respiratory failure, they said.

The researchers explained that in the absence of a specific antiviral cure for COVID-19, the goal of treatment must be to the fight the symptoms, and lowering the mortality rate through intensive maintenance of organ function.

For example, an artificial liver blood purification system or renal replacement therapy can be used to filter the blood through mechanical means, they said.

The team noted that especially important are methods to supplement or replace lung function, for example with non-invasive mechanical ventilation through a mask, ventilation through a tube into the windpipe, the administration of heated and humidified oxygen via a tube in the nose, or a heart-lung bypass.

The researchers stressed the importance of preventing secondary infections.

They noted that SARS-Cov-2 also invades the intestines, where it causes inflammation and leakiness of the gut lining, allowing the opportunistic entry of other disease-causing microorganisms.

The researchers advocate that this should be prevented with nutritional support, for example with probiotics -- beneficial bacteria that protect against the establishment of harmful ones -- and nutrients and amino acids to improve the immune defences and function of the intestine.

"Because treatment for now relies on aggressive treatment of symptoms, preventative protection against secondary infections, such as bacteria and fungi, is particularly important to support organ function, especially in the heart, kidneys, and liver, to try and avoid further deterioration of their condition," Liu added.