Inhibition of a viral enzyme by a small-molecule dimer disruptor.

We identified small-molecule dimer disruptors that inhibit an essential dimeric protease of human Kaposi's sarcoma-associated herpesvirus (KSHV) by screening an alpha-helical mimetic library. Next, we synthesized a second generation of low-micromolar inhibitors with improved potency and solubility. Complementary methods including size exclusion chromatography and 1H-13C HSQC titration using selectively labeled 13C-Met samples revealed that monomeric protease is enriched in the presence of inhibitor. 1H-15N HSQC titration studies mapped the inhibitor binding site to the dimer interface, and mutagenesis studies targeting this region were consistent with a mechanism where inhibitor binding prevents dimerization through the conformational selection of a dynamic intermediate. These results validate the interface of herpesvirus proteases and other similar oligomeric interactions as suitable targets for the development of small-molecule inhibitors

Testing dynamic correlations and nonlinearity in bivariate time series through information measures and surrogate data analysis

The increasing availability of time series data depicting the evolution of physical system properties has prompted the development of methods focused on extracting insights into the system behavior over time, discerning whether it stems from deterministic or stochastic dynamical systems. Surrogate data testing plays a crucial role in this process by facilitating robust statistical assessments. This ensures that the observed results are not mere occurrences by chance, but genuinely reflect the inherent characteristics of the underlying system. The initial process involves formulating a null hypothesis, which is tested using surrogate data in cases where assumptions about the underlying distributions are absent. A discriminating statistic is then computed for both the original data and each surrogate data set. Significantly deviating values between the original data and the surrogate data ensemble lead to the rejection of the null hypothesis. In this work, we present various surrogate methods designed to assess specific statistical properties in random processes. Specifically, we introduce methods for evaluating the presence of autodependencies and nonlinear dynamics within individual processes, using Information Storage as a discriminating statistic. Additionally, methods are introduced for detecting coupling and nonlinearities in bivariate processes, employing the Mutual Information Rate for this purpose. The surrogate methods introduced are first tested through simulations involving univariate and bivariate processes exhibiting both linear and nonlinear dynamics. Then, they are applied to physiological time series of Heart Period (RR intervals) and respiratory flow (RESP) variability measured during spontaneous and paced breathing. Simulations demonstrated that the proposed methods effectively identify essential dynamical features of stochastic systems. The real data application showed that paced breathing, at low breathing rate, increases the predictability of the individual dynamics of RR and RESP and dampens nonlinearity in their coupled dynamics

Zn concentrations in wheat grains along the gradient of native Zn soil availability in Serbia

Zinc (Zn) is an essential microelement for plants and also an important nutritional and health factor in humans. As a consequence of low Zn availability in soils, nearly half of the world's population suffers from Zn malnutrition. Zn deficiency has serious implications for human health (e.g. impairments in physical development, immune system, brain function and learning ability) and thus for the overall economy of a country; it is most severe in nations who depend on cereals as the main staple food. A critical Zn concentration in the whole grain for humans that depend on cereal based diets is 24 mg kg-1 dry matter. Research focused on increase of Zn content in cereals (biofortification), is the strategic priority in many countries. In Serbia however, the awareness of this problem is lacking, and no systematic survey of Zn availability in soi ls and concentrations in cereal grains has been undertaken so far. Our study included 156 grain samples of the two major bread wheat varieties (Simonida and NS 40S) collected at 89 localities throughout Serbia. We analyzed soil pH, available Zn and grain Zn concentration together by principle component analysis and multiple linear regression. Wheat varieties did not differ in ability to accumulate Zn in grains. Both soil pH and available Zn concentration were the nominally significant predictors for grain Zn concentration and explained about 12 and 9% of the encountered variation, respectively. Zn concentration below the critical limit (24 mg kg-1) was found in 58% of grain samples (values in the range 11-61 mg kg-1, median only 21.3 mg kg-1), while in only 14% of soil samples the available Zn was below the critical value (05 mg kg-1). The most severe lack of Zn in grains (below 18 mg kg-1) was observed in samples from the major production regions of bread wheat (e.g. Pancevo, Vrbas and Sremska Mitrovica). The alarming results of this survey indicate that Serbia urgently needs a strategy for Zn biofortification, primarily through a breeding program to enhance Zn efficiency as a sustainable alternative to application of Zn fertilizers

Microscale thermophoresis quantifies biomolecular interactions under previously challenging conditions

Item does not contain fulltextMicroscale thermophoresis (MST) allows for quantitative analysis of protein interactions in free solution and with low sample consumption. The technique is based on thermophoresis, the directed motion of molecules in temperature gradients. Thermophoresis is highly sensitive to all types of binding-induced changes of molecular properties, be it in size, charge, hydration shell or conformation. In an all-optical approach, an infrared laser is used for local heating, and molecule mobility in the temperature gradient is analyzed via fluorescence. In standard MST one binding partner is fluorescently labeled. However, MST can also be performed label-free by exploiting intrinsic protein UV-fluorescence. Despite the high molecular weight ratio, the interaction of small molecules and peptides with proteins is readily accessible by MST. Furthermore, MST assays are highly adaptable to fit to the diverse requirements of different biomolecules, such as membrane proteins to be stabilized in solution. The type of buffer and additives can be chosen freely. Measuring is even possible in complex bioliquids like cell lysate allowing close to in vivo conditions without sample purification. Binding modes that are quantifiable via MST include dimerization, cooperativity and competition. Thus, its flexibility in assay design qualifies MST for analysis of biomolecular interactions in complex experimental settings, which we herein demonstrate by addressing typically challenging types of binding events from various fields of life science

General practitioners’ perceptions of using virtual primary care during the COVID-19 pandemic: An international cross-sectional survey study

With the onset of COVID-19, general practitioners (GPs) and patients worldwide swiftly transitioned from face-to-face to digital remote consultations. There is a need to evaluate how this global shift has impacted patient care, healthcare providers, patient and carer experience, and health systems. We explored GPs’ perspectives on the main benefits and challenges of using digital virtual care. GPs across 20 countries completed an online questionnaire between June–September 2020. GPs’ perceptions of main barriers and challenges were explored using free-text questions. Thematic analysis was used to analyse the data. A total of 1,605 respondents participated in our survey. The benefits identified included reducing COVID-19 transmission risks, guaranteeing access and continuity of care, improved efficiency, faster access to care, improved convenience and communication with patients, greater work flexibility for providers, and hastening the digital transformation of primary care and accompanying legal frameworks. Main challenges included patients’ preference for face-to-face consultations, digital exclusion, lack of physical examinations, clinical uncertainty, delays in diagnosis and treatment, overuse and misuse of digital virtual care, and unsuitability for certain types of consultations. Other challenges include the lack of formal guidance, higher workloads, remuneration issues, organisational culture, technical difficulties, implementation and financial issues, and regulatory weaknesses. At the frontline of care delivery, GPs can provide important insights on what worked well, why, and how during the pandemic. Lessons learned can be used to inform the adoption of improved virtual care solutions and support the long-term development of platforms that are more technologically robust and secure

Cross-Cultural Validation of the Definition of Multimorbidity in the Bulgarian Language.

INTRODUCTION: Multimorbidity is a health issue with growing importance. During the last few decades the populations of most countries in the world have been ageing rapidly. Bulgaria is affected by the issue because of the high prevalence of ageing population in the country with multiple chronic conditions. The AIM of the present study was to validate the translated definition of multimorbidity from English into the Bulgarian language. MATERIALS AND METHODS: The present study is part of an international project involving 8 national groups. We performed a forward and backward translation of the original English definition of multimorbidity using a Delphi consensus procedure. RESULTS: The physicians involved accepted the definition with a high percentage of agreement in the first round. The backward translation was accepted by the scientific committee using the Nominal group technique. DISCUSSION: Some of the GPs provided comments on the linguistic expressions which arose in order to improve understanding in Bulgarian. The remarks were not relevant to the content. The conclusion of the discussion, using a meta-ethnographic approach, was that the differences were acceptable and no further changes were required. CONCLUSIONS: A native version of the published English multimorbidity definition has been finalized. This definition is a prerequisite for better management of multimorbidity by clinicians, researchers and policy makers