Day: August 31, 2022

Categories : AllergiesTags :

A New Guideline for Pollen Food Syndrome

On By ModernMedia
Photo by Daria Shevtsova on Pexels

Pollen Food Syndrome (PFS) – also known as oral allergy syndrome or pollen food allergy syndrome – causes affected individuals to experience an allergic reaction when consuming raw plant foods, and triggers can vary depending on an individual’s pollen sensitisation, which in turn is affected by geographical location. A guideline, published in Clinical & Experimental Allergy, has been developed for the diagnosis and management of PFS.

The guideline was drafted by the British Society of Allergy & Clinical Immunology Standards of Care Committee. The correct diagnosis of PFS ensures the avoidance of a misdiagnosis of a primary peanut or tree nut allergy or confusion with another plant food allergy to non-specific lipid transfer proteins. The characteristic foods involved, and rapid-onset oropharyngeal symptoms, mean PFS can often be diagnosed from the clinical history alone. Management focuses on avoiding known trigger foods, which may appear to be simple, but can be difficult if coupled with a pre-existing food allergy, or for individuals following a vegetarian/vegan diet.

“More studies on the effect of PFS on health-related quality of life are needed to dispel the myth that because it usually manifests with mild symptoms, PFS is easily managed, and does not adversely affect the individual,” the authors wrote. “The number of foods and concern about new food triggers means dietary restrictions are often overly strict, so more research on novel treatments of PFS, including food immunotherapy, needs to be undertaken.”

Source: Wiley

Categories : Cardiovascular DiseaseTags :

A Simple Low-cost Method to Identify Aortic Valve Stenosis

On By ModernMedia
Source: CC0

In the Journal of Applied Physics, researchers developed a method to identify aortic valve stenosis using complex network analysis that is accurate, simple to use, and low-cost.

Aortic valve stenosis occurs when the aortic valve narrows, constricting blood flow from the heart through the artery and to the entire body. In severe cases, it can lead to heart failure. Identifying the condition can be difficult in remote areas because it requires sophisticated technology, and diagnoses at early stages are challenging to obtain.

“Many rural health centres don’t have the necessary technology for analysing diseases like this,” said author M.S. Swapna, of the University of Nova Gorica and the University of Kerala. “For our technique, we just need a stethoscope and a computer.”

The diagnostic tool works based on the sounds produced by the heart. The organ creates a “lub” noise as it closes the mitral and tricuspid valves, pauses as ventricular relaxation occurs and the blood fills in, then makes a second noise, “dub,” as the aortic and pulmonary valves close.

Swapna and her team used heart sound data, collected over 10 minutes, to form a graph. This was then split into sections, with each part representing with a node on the graph. If the sound in that portion of the data was similar to another section, a line was drawn between the two nodes.

In a healthy heart, the graph showed two distinct clusters of points, with many nodes unconnected. In contrast, a heart with aortic stenosis contained many more correlations and edges.

“In the case of aortic stenosis, there is no separation between the ‘lub’ and ‘dub’ sound signals,” explained Swapna.

The researchers used machine learning to examine the graphs and identify those with and without disease, achieving a classification accuracy of 100%. Their method takes the correlation of each point under consideration, making it more accurate than others that only consider the strength of the signal, and it does so in less than 10 minutes. As such, it could be useful for early-stage diagnoses.

So far, the method has only been tested with data, not in a clinical setting. The authors are developing a mobile application that could be accessed worldwide. Their technique could also be used to diagnose other conditions.

“The proposed method can be extended to any type of heart sound signals, lung sound signals, or cough sound signals,” said Swapna.

Source: American Institute of Physics

Categories : Obstetrics & GynaecologyTags :

Scientists Test A Potential New Therapy for Preeclampsia

On By ModernMedia
Pregnant with ultrasound image
Source: Pixabay

Researchers have proposed a new therapy for preeclampsia that corrects the defects identified in placental cells, and restores placental and foetal weight, which they report in the journal Redox Biology. The treatment, tested in two rodent models, successfully lowers blood pressure in the mother and resolves the characteristic preeclampsia symptoms of proteinuria and cardiovascular abnormalities.

Preeclampsia is a placental dysfunction that affects approximately 2 to 8% of pregnant women worldwide. It can have potentially complications for mother and child, and longer-term consequences for the mother. Preeclampsia symptoms are primarily arterial hypertension, proteinuria, abnormal coagulation in the placenta, cardiovascular abnormalities in the mother and foetal growth restriction. Treatments for preeclampsia are limited and mostly involve aspirin as a preventative measure, reducing the procoagulant state in the placenta and partly relieving pressure on the vascular network.

Preeclampsia is characterised by a defective placenta caused by trophoblast dysfunction. Trophoblasts are placental cells that help organise and manage the vascular network which provides the essential resources for foetal growth. At the molecular level, preeclampsia is characterised by an uncontrolled increase in oxidative stress, with excessive production of various reactive species including reactive oxygen and nitrogen species. There is a genetic component: the first gene to be identified as being implicated in the genetic forms of preeclampsia was the STOX1 transcription factor, which controls the expression of thousands of genes, especially those involved in the production of nitric oxide (NO).

In a transgenic mouse model, high accumulation of STOX1 in the placenta induced a preeclampsia-like syndrome. In preeclampsia, NO, a powerful vasodilator that promotes blood flow to the placenta, is mobilised to produce potentially toxic molecules (nitrosative stress) and its levels become insufficient in the placental vascular network, affecting trophoblast function and the vascular network and destabilising other reactive species. This creates a vicious circle and causes uncontrollable oxidative/nitrosative stress with multiple complications, also affecting maternal blood vessel cells, with potentially fatal consequences.

NO is produced by a family of enzymes known as nitric oxide synthases (NOSs). Finding a way of restoring NO production in the placenta via NOSs could represent an effective new therapy to treat preeclampsia. A years-long collaboration gave rise to a potential solution. The scientists’ research was based on trophoblasts overexpressing STOX1 and on two rodent models of preeclampsia, one mimicking early-onset forms via placental overexpression of STOX1 and the other mimicking late-onset forms by partial occlusion of the lower abdominal aorta.

The research revealed a cascade of events that ultimately led the scientists to propose a new therapy. Treating trophoblasts with BH4 (tetrahydrobiopterin, a cofactor that stabilises the NOS enzyme producing NO) corrected the defects identified in these cells, restoring production of NO rather than potentially toxic molecules. More importantly, administering BH4 to the two preclinical rodent models restored placental and foetal weight. Finally, in the early-onset STOX1 preclinical model with significant arterial hypertension and proteinuria, the BH4 treatment corrected blood pressure, excess protein in urine, and cardiovascular abnormalities in the mother. The results even suggest that the treatment may be effective in addressing the long-term effects of preeclampsia on mothers (vascular abnormalities in the brain, kidneys, heart and liver).

This research is the first step towards the development of a therapy for preeclampsia. Genetic analyses of placentas treated with BH4 showed that it corrects the expression of several genes disrupted by excess STOX1 differently than the deregulation induced by aspirin in the placenta. The scientists therefore propose that a treatment combining BH4 and aspirin could be the ultimate therapeutic solution for many cases of preeclampsia. This hypothesis needs to be validated in clinical trials.

Source: Institut Pasteur