Search

Gangliosides form an important class of receptor lipids containing a large oligosaccharide headgroup whose ability to self-organize within lipid membranes results in the formation of nanoscopic platforms. Despite their biological importance, the molecular basis for the nanoscopic segregation of gangliosides is not clear. In this work, we investigated the role of the ganglioside headgroup on the nanoscale organization of gangliosides. We studied the effect of the reduction in the number of sugar units of the ganglioside oligosaccharide chain on the ability of gangliosides GM 1 , GM 2 , and GM 3 to spontaneously self-organize into lipid nanodomains. To reach nanoscopic resolution and to identify molecular forces that drive ganglioside segregation, we combined an experimental technique, Förster resonance energy transfer analyzed by Monte-Carlo simulations offering high lateral and trans-bilayer resolution with molecular dynamics simulations. We show that the ganglioside headgroup plays a key role in ganglioside self-assembly despite the negative charge of the sialic acid group. The nanodomains range from 7 to 120 nm in radius and are mostly composed of the surrounding bulk lipids, with gangliosides being a minor component of the nanodomains. The interactions between gangliosides are dominated by the hydrogen bonding network between the headgroups, which facilitates ganglioside clustering. The N-acetylgalactosamine sugar moiety of GM 2 , however, seems to impair the stability of these clusters by disrupting hydrogen bonding of neighboring sugars, which is in agreement with a broad size distribution of GM 2 nanodomains. The simulations suggest that the formation of nanodomains is likely accompanied by several conformational changes in the gangliosides, which, however, have little impact on the solvent exposure of these receptor groups. Overall, this work identifies the key physicochemical factors that drive nanoscopic segregation of gangliosides., (Copyright © 2021 Biophysical Society. Published by Elsevier Inc. All rights reserved.)

Nutrition and health claims (NHCs) are a powerful tool that influence consumers' final decision on the choice of food products. The purposes of this repeated cross-sectional study were to (i) assess the prevalence of pre-packaged food products containing nutrition and health claims among different food categories, (ii) to determine the type of NHCs labelled on the examined food products, and (iii) to evaluate the trend in the use of NHCs in comparison to the 2012 survey. The survey was conducted immediately before the full enforcement of the new national legislation on NHCs in 2020. It comprised 3141 pre-packaged food products from 10 product categories. In total, 21.2% of food products contained any claim (19.4% contained any nutrition claim; 8.2% contained any health claim). In comparison to the 2012 survey, we observed a rising trend in the presence of NHCs; the use of nutrition claims on food products increased three times and the use of health claims increased 1.3 times in the 2020 survey. Bearing in mind that NHCs are a powerful tool guiding consumers' food purchase decisions, NHCs should be supported by precise legislation and strict surveillance by the public health authorities.

Spike glycoprotein is essential for the reproduction of the SARS-CoV-2 virus, and its inhibition using already approved antiviral drugs may open new avenues for treatment of patients with the COVID-19 disease. Because of that we analyzed the inhibition of SARS-CoV-2 spike glycoprotein with FDA-approved antiviral drugs and their double and triple combinations. We used the VINI in silico model of cancer to perform this virtual drug screening, showing HIV drugs to be the most effective. Besides, the combination of cobicistat-abacavir-rilpivirine HIV drugs demonstrated the highest in silico efficacy of inhibiting SARS-CoV-2 spike glycoprotein. Therefore, a clinical trial of cobicistat-abacavir-rilpivirine on a limited number of COVID-19 patients in moderately severe and severe condition is warranted., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 The Authors.)

Two algorithms for calculating overlaps between CIS (or TDDFT) type excited state wave functions are presented, one based on an expansion of overlap determinants into level 2 minors (OL2M) and the other based on an expansion of the wave functions into natural transition orbitals (ONTO). Both algorithms are significantly faster than previously available algorithms, with the ONTO algorithm reducing the cost of a single overlap element calculation by a factor of the square of the number of occupied orbitals in the system. The algorithm exhibits orders of magnitude faster calculations for large systems and significantly increases the size of systems for which TDDFT based nonadiabatic dynamics simulations can be performed. The OL2M algorithm is substantially slower for a single overlap matrix element but becomes preferred when overlaps between large numbers of states are required. Additionally, we test the accuracy of approximate overlaps calculated using truncated wave functions and show that truncation can lead to large errors in the overlaps. Lastly, we provide examples of applications for wave function overlaps outside the context of nonadiabatic dynamics.

Introduction: Medical studies bring many stressful activities to students. Prolonged stress can make adverse effects to mental health and lead to further professional burnout., Objective: The aim of this study was to assess the association of stress impact and adverse effects of medical studies with psychological distress among medical students., Methods: The cross sectional study was conducted on 367 fourth-year medical students of the Faculty of Medicine in Belgrade, by means of the anonymous questionnaire, containing: socio-demographic data, self-reported health status and stressful influences of studying activities. Mental health status was estimated by General Health Questionnaire (GHQ-12)., Results: More than 50% of students perceive frequent feeling of psychic tension, and one third has problems with insomnia. Nearly one-half of students assessed their general stress level as moderate or high. Exams were estimated as high stressor in 63.1% of all students. Stressful effects of communication with teaching staff were reported by one quarter of the examinees. The scores of GHQ-12 were above the threshold in 55.6% of all students. Mental health problems among students were most significantly associated with stressful experience during exams and contacts with teaching staff., Conclusion: Academic stress makes great influence on mental health of medical students. Reduction of stress effects should be directed to optimization of the examination process and improvement of communication skills.

Objective: We investigated the effects of bisoprolol and losartan on subjects with essential hypertension, by conducting heart rate variability (HRV) analysis of ECG signals. Our intention was to establish the set of linear and nonlinear heart rate variability parameters, which could be used as a noninvasive markers in the treatment of hypertension., Materials and Methods: Sixty subjects with essential hypertension included in this study were divided in two groups. During the four weeks medical treatment, the first group was administered with daily oral dose of 5 mg of bisoprolol and the second with daily oral dose of 50 mg of losartan. We recorded ECG signals, and performed HRV analysis of consecutive RR time intervals, before and after a month of pharmacological therapy., Results: IN THE CASE OF BISOPROLOL, STATISTICALLY THE MOST SIGNIFICANT CHANGES OF HRV PARAMETERS WERE: TP (1814.1 ± 1731.3 ms(2) vs. 761.3 ± 725.0 ms(2), P < 0.0001), RR (870.2 ± 105.7 ms vs. 1027.2 ± 150.0 ms, P < 0.0001), HR (70.81 ± 8.42 bp/min vs. 60.10 ± 9.52 bp/min, P < 0.0001). In the case of losartan, the most significant changes were: SDNN (43.16 ± 17.27 ms vs. 237.98 ± 118.54 ms, P = 0.002), rmSDD (27.09 ± 18.27 ms vs. 46.82 ± 37.71 ms, P = 0.003), SD2 (55.18 ± 20.6 vs. 70.67 ± 26.12, P < 0.019) and DF2 (0.69 ± 0.21 vs. 0.86 ± 0.25, P < 0.014)., Conclusion: Effects of bisoprolol and losartan were especially manifested among the set of linear HRV parameters. As a consequence of effect of losartan, we singled out the nonlinear parameters SD2 and DF2.

The WHO International Classification of Functioning, Disability and Health (ICF) provides a coherent view of health from a biological, individual and social perspective. This view may be defined both as multi- and interdisciplinary management of one's functioning and health. This new classification is currently being assessed in multiple centres in 32 countries, on 12 health conditions. The Institute of Hygiene and Medical Ecology, School of Medicine, University of Belgrade, is one of them, serving as the centre where the classification is being tested in obese population. The objective of this paper is to provide information needed for further development and practical application of this classification in various health conditions. The new language of ICF is an exciting landmark event for preventive medicine and rehabilitation. It may lead to a stronger position of rehabilitation within the medical community, change multiprofessional communication and improve communication between patients and health professionals.

It is shown that the dielectric response of Ba(0.77)Sr(0.23)TiO(3) nanoparticles at temperatures below 200 K has a frequency and temperature dependence in agreement with the Debye theory with a single relaxation time, which exhibits the Arrhenius law. By contrast, at temperatures above 210 K the dielectric response exhibits a broad range of relaxation times characteristic of relaxor-ferroelectrics. We suggest that the single relaxation time at low temperature originates from a frustration effect, in analogy with frustrated antiferromagnetism.

Introduction: The prevalence of obesity is rising to epidemic proportions at the alarming rate in both developed and underdeveloped countries around the world. Current prevalence data from individual national studies suggest that the obesity prevalence in the European countries ranges from 10% to 20% for men, and 10% to 25% for women. Health consequences of obesity imply both a number of fatal and non-fatal health problems (out of which the most common are cardiovascular problems, non-insulin dependent diabetes mellitus, cancers), and also a wide spectrum of psychological consequences from diminished self-esteem to clinical depression. Causal relationship between obesity and many chronic diseases is evidence-based. At the same time, there are marked differences in research data regarding causal obesity-depression relationship. Several studies have found no direct association between obesity and depression, while in others the prevalence of depression in obese patients was up to 50%. Gender, obesity grade, socioeconomic status and asking for professional help are named as moderators and mediators of this relationship. Among recommended screening methods, BDI-II is the most frequently used in the adult outpatient departments., Objective: The aim of the study was to determine possible risk factors of depression in adult obese patients treated for obesity. Gender, obesity and education level as well as marital status were analyzed as possible moderators of depression-obesity relationship., Method: The research included 267 patients, 38.0 +/- 14.6 years of age, who referred to the Outpatient Nutrition Department for dietetic consultation or nutritional medical therapy. Nutritional status was assessed by BMI (kg/m2), calculated from measured values of body weight and height according to WHO recommendations. An estimate of the existence and/or depression level was investigated by Beck Depression Inventory--self-administered questionnaire recommended for use in Serbian population., Results: The results revealed higher average BDI score values in obese patients (F(267,1) = 6.014, p = 0.015) in comparison to their non-obese counterparts. In addition, the percentage of depressive obese patients was significantly higher (55.1%, chi2(267.1) = 22.64, p < 0.001). There was significant correlation of BMI and BDI scores (r = 0.246, p < 0.001). The number of women with depression was significantly higher in comparison to men (chi2(267.1) = 4.261, p = 0.039). Women also had higher average BDI score (p = 0.003). MANOVA showed that BDI score was influenced by gender (F(267.1) = 8.936, p = 0.030) and nutritional status (F(267.1) = 6.115, p = 0.014), but combined effect of the above-mentioned moderators was not significant., Conclusion: Depression is ten times more frequent in obese patients undergoing the obesity treatment vs. general population and, therefore, screening for depression is needed. Special attention should be paid to women and more obese patients due to higher incidence of depression in these groups.

Max Josef von Pettenkofer was one of the leading personalities in the world of medicine in the 19th century. He was the founder of the modern science of hygiene. In his experimental work, he was involved in the research of problems dealing with the relationship between human beings and the environment, including such topics as soil and air pollution, water supply, sewage water management, room ventilation and heating, as well as the function of clothing and the cleanliness of homes and streets. Pettenkofer also studied the onset, the course, and the consequences of infectious diseases, such as cholera and typhus. He realised the great economic value of public health and emphasised that personal preventive measures should be supplemented with the improvement of factors in communal and work environments. His efforts lead to hygiene becoming a part of medical studies in 1865. The Institute for Hygiene at the School of Medicine in Munich was established in 1879. It was constructed according to his drawings and was considered to be the most modern institute for hygiene in the world. Since hygiene was a subject on the school curriculum in the German Empire in 1882, Pettenkofer became the Chairman of Hygiene in Berlin in 1885. Research institutions established by Pettenkofer and the fact that many of his students became professors of hygiene speak about the importance of his work. One of his students was professor Milan Jovanović Batut, founder of the Institute for Hygiene at the School of Medicine in Belgrade.

The purpose of this study was to present 11 patients operated on owing to rare forms of peripheral arterial embolism at the Institute for Cardiovascular Diseases of the Serbian Clinical Center over a period of 20 years. Three patients were operated on owing to a foreign body embolism, two owing to a septic embolism, three owing to emboli that originated from malignant tissues, two owing to an embolization from cardiac myxoma, and one owing to an embolism from a myxomatous atrial septal defect. The preoperative evaluation included clinical examination, laboratory findings, and electrocardiography; in the majority of cases, ultrasonography and angiography were performed. Surgical treatment included foreign body extraction in three cases; thromboembolectomy in seven cases, and artery resection and saphenous graft interposition in one patient with septic embolism. In addition, three cardiosurgical procedures were done: aortic valve replacement in the patient with a septic embolism and tumor excision in patients with atrial myxoma. In addition to the usual clinical signs of acute limb ischemia, in the rare forms of arterial embolism, the presence of certain uncommon clinical symptoms was also observed. The early results of vascular surgical treatment were very good in all patients. Further follow-up revealed a poor prognosis in patients with malignant arterial embolism.