A summary of characteristics of the first wave of new type coronavirus epidemic and potential association with tuberculosis vaccination / Az új koronavírus okozta járvány elso hullámának jellemzoi és esetleges kapcsolata a tuberkulózis elleni oltottsággal.

Összefoglaló. Bevezetés: A COVID-19-járvány az egész világon elterjedt. A járvány Európában való elso megjelenése során megfigyelheto volt, hogy a terjedés mértéke kisebb azokban az országokban, ahol a tuberkulózis elleni védekezésül kiterjedt BCG-vakcinációt végeznek. Célkituzés: A jelen munkában olyan összefüggéseket igyekeztünk feltárni, amelyek befolyásolták a járványterjedés paramétereit, különös figyelemmel a BCG-vakcinációs gyakorlatra. Módszerek: A világ összes olyan országára vonatkozóan, ahol megfelelo minoségu statisztikai adatok álltak rendelkezésünkre, vizsgáltuk a járvány terjedésének elso hullámát. A mozgóátlagolt járványgörbéken elemeztük a járvány idotartamát, a tetozés mértékét, a fertozöttek és a halálesetek egymillió lakosra vetített számát. Figyelembe vettük az országok gazdasági mutatóit (GDP, légi forgalom, a tengeri hajózás mértéke). Statisztikai analízis: A vizsgált paraméterek nem mutattak normális eloszlást, így nemparaméteres próbákkal (rangkorreláció, Kruskal-Wallis ANOVA) statisztikai kapcsolatot kerestünk a járványterjedés mértéke, a BCG-vakcináció és más paraméterek között. Eredmények: A járvány gyorsan elterjedt a világon, de mégis, február elso három hetében a terjedésben egy szünet volt megfigyelheto. A járványhullám Európában nagyjából egyszerre ért véget. A járvány által leginkább azok az országok érintettek, ahol nem alkalmaztak rendszeres BCG-vakcinációt, bár a képet bonyolítja, hogy ezek az országok gazdaságilag többnyire fejlettek. A halálozási rátában nem mutatkozott ilyen különbség. Következtetés: Statisztikailag igazolható tény, hogy a vakcinációt végzo országokból az elso hullám alatt kevesebb fertozöttet jelentettek; az ok-okozati összefüggés bizonytalan, hiszen az országok múltja, szokásai, társadalmi berendezkedése, gazdasági fejlettsége nem azonos. Eredményeink alátámasztják az összehasonlító kontaktkutatás fontosságát annak tisztázására, hogy a BCG-oltás hogyan befolyásolja az emberek vírussal szembeni érzékenységét, valamint a vírus terjesztésének, továbbadásának képességét. Orv Hetil. 2021; 162(4): 123-134. INTRODUCTION: The new type of coronavirus (SARS-CoV-2) epidemic is widespread throughout the world. During the outbreak of the pandemic in Europe it was revealed that the rate of spread was lower in countries where extensive BCG vaccination is used to protect against tuberculosis. OBJECTIVE: In the present work, we sought to explore relationships that influenced epidemic spreading parameters, with particular reference to BCG vaccination practice. METHODS: We examined the first wave of the spread of the epidemic for all countries in the world where adequate quality statistics were available. We analyzed the duration of the epidemic, the extent of the peak, the number of infected people, and the number of deaths per million inhabitants with the moving average of epidemic curves. We took into account the economic indicators of the countries (GDP, air traffic and extent of maritime shipping). STATISTICAL ANALYSIS: The examined parameters did not show a normal distribution, so we looked for a statistical relationship with non-parametric tests (rank correlation, Kruskal-Wallis ANOVA) between the extents of epidemic spread, BCG vaccination and other parameters. RESULTS: The epidemic spread rapidly around the world, but still, in the first three weeks of February, there was a pause in the spread. The first wave of epidemics ended roughly at the same time in Europe. Those countries are the most affected by the epidemic where regular BCG vaccination has not been used, although the picture is complicated by the fact that these countries are mostly economically developed. There was no such difference observable in the mortality rate. CONCLUSION: Although this work clearly demonstrates that during the first wave of the pandemic, fewer infections were reported worldwide in countries where BCG vaccination is obligatory, however, the causal relationship is uncertain, as the countries' past, customs, social organization and economic development are different. Our results support the necessity of comparative contact tracing to clarify how BCG vaccination affects people's susceptibility to this new type of coronavirus as well as their ability to spread and transmit the virus. Orv Hetil. 2021; 162(4): 123-134.

Loop F of the GABAA receptor alpha subunit governs GABA potency.

Gamma-amino butyric acid (GABA) is an abundant neurotransmitter in the CNS. GABAergic interneurons orchestrate pyramidal neurons in the cerebral cortex, and thus control learning and memory. Ionotropic receptors for GABA (GABAAR) are heteropentameric complexes of α, ß and γ integral membrane-protein subunits forming Cl- -channels operated by GABA, which are vital for brain function and are important drug targets. However, knowledge on how GABAAR bind GABA is controversial. Structural biology versus functional modelling combined with site-directed mutagenesis suggest markedly different roles for loop F of the extracellular domain of the α-subunit when complexed with GABA. Here, we report that contrary to the results of structural studies, loop F of the α-subunit controls the potency of GABA on GABAAR. We examined the effect of replacing a short, variable segment of loop F of the GABAA α5-subunit with the corresponding segment of the α2-subunit (GABAA5_LF2) and vice versa (GABAA2-LF5). When compared with their respective wild-type counterparts, GABAA5_LF2 receptors displayed enhanced sensitivity towards GABA, whilst in GABAA2-LF5 sensitivity was diminished. Mice homozygous for the genetic knock-in of the GABAA5_LF2 subunit showed a marked deficit in long- but not short-term object recognition memory. Working memory in place learning, spontaneous alternation and the rewarded T-maze were all normal. The deficit in long-term recognition memory was reversed by an α5-GABAA negative allosteric modulator compound. The data show that loop F governs GABA potency in a receptor isoform-specific manner in vitro. Moreover, this mechanism of ligand recognition appears to be operative in vivo and impacts cognitive performance.

Optical waveguide lightmode spectroscopic techniques for investigating membrane-bound ion channel activities.

Optical waveguide lightmode spectroscopic (OWLS) techniques were probed for monitoring ion permeation through channels incorporated into artificial lipid environment. A novel sensor set-up was developed by depositing liposomes or cell-derived membrane fragments onto hydrophilic polytetrafluoroethylene (PTFE) membrane. The fibrous material of PTFE membrane could entrap lipoid vesicles and the water-filled pores provided environment for the hydrophilic domains of lipid-embedded proteins. The sensor surface was kept clean from the lipid holder PTFE membrane by a water- and ion-permeable polyethylene terephthalate (PET) mesh. The sensor set-up was tested with egg yolk lecithin liposomes containing gramicidin ion channels and with cell-derived membrane fragments enriched in GABA-gated anion channels. The method allowed monitoring the move of Na(+) and organic cations through gramicidin channels and detecting the Cl(-)-channel functions of the (α5ß2γ2) GABAA receptor in the presence or absence of GABA and the competitive GABA-blocker bicuculline.

Effects of vitamin D on immune disorders with special regard to asthma, COPD and autoimmune diseases: a short review.

This paper reviews the recent data on the role of vitamin D (VD) in the genesis of various immunological disorders. It inhibits immune reactions in general, but it enhances the transcription of 'endogenous antibiotics' such as cathelicidin and defensins. VD inhibits the genesis of both Th1- and Th2-cell mediated diseases. The pleiotropic character VD-induced effects are due to the altered transcription of hundreds of genes. VD supplementation in most related studies reduced the prevalence of asthma. Th1-dependent autoimmune diseases (e.g., multiple sclerosis, Type 1 diabetes, Crohn's disease, rheumatoid arthritis and so on) are also inhibited by VD due to inhibition of antigen presentation, reduced polarization of Th0 cells to Th1 cells and reduced production of cytokines from the latter cells. VD seems to also be a useful adjunct in the prevention of allograft rejection. Last but not least, VD supplementation may be useful in the prevention or adjunct treatment of chronic obstructive pulmonary disease.

Extracellular alkalinization stimulates calcium-activated chloride conductance in cystic fibrosis human airway epithelial cells.

BACKGROUND: The pH of the airway surface liquid (ASL) plays a pivotal role in maintaining the proper function of the respiratory epithelium. In patients with cystic fibrosis (CF) acidic ASL has been observed. Thus, alkalinization of ASL itself might be beneficial in CF. The aim of this study was to investigate the role of extracellular pH (pH(o)) on the alternative Ca(2+)-activated Cl(-) channels (CaCCs) in CF airway epithelial cells. METHODS: The [Ca(2+)](i) and viability of CF airway epithelial cells (IB3-1) were assessed using Fluo-3/AM and YO-PRO-1 fluorescent dyes, respectively. Ion currents were detected in whole-cell configuration using the patch clamp technique. RESULTS: Extracellular alkalinization (pH(o) 8.2) stimulated Ca(2+) entry and inward currents in low Na(+) containing medium. The inward currents were blocked by the removal of extracellular Ca(2+), chelating cytosolic Ca(2+), as well as by the application of niflumic acid and DIDS. While Zn(2+) promoted sustained Ca(2+) entry in pH(o)-dependent manner, it inhibited the anion conductance. The low external Na(+) concentrations and alkaline pH(o) were well tolerated by the cells. CONCLUSIONS: Stimulation of CaCCs could be achieved by alkalinization of the extracellular environment in CF airway epithelial cells. Zn(2+) directly blocked, however indirectly enhanced the activity of Cl(-) conductance.

Calcium entry is regulated by Zn2+ in relation to extracellular ionic environment in human airway epithelial cells.

The extracellular pH, sodium and divalent cation concentrations influence the ATP-induced changes in cytosolic Ca(2+) concentration ([Ca(2+)](i)). This elevation of [Ca(2+)](i) and activation of Ca(2+)-dependent Cl(-) channels represent a possible therapeutic approach in cystic fibrosis (CF). We investigated the changes of [Ca(2+)](i) in different external ionic environment, and P2X purinergic receptors (P2XRs) expression in the control and CF airway epithelial cells. The parallel removal of Na(+) and alkalinization of the extracellular solution increased the amplitude of sustained ATP-induced Ca(2+) signals independent of wild-type or mutant CFTR expression. The ATP-induced Ca(2+) entry was either inhibited or stimulated by Zn(2+) depending on the extracellular Na(+) concentration. In Na(+)-free environment, Zn(2+) and other divalent cations elicited a biphasic Ca(2+) signal. Immunohistochemical data suggest that, multiple subtypes of P2XRs are expressed in these airway epithelial cells. In conclusion, Ca(2+) entry is finely regulated by external ionic environment. Therefore, we speculate that properly compiled aerosols could influence efficacy of zinc-based therapy in CF.

Simultaneous PKC and cAMP activation induces differentiation of human dental pulp stem cells into functionally active neurons.

The plasticity of dental pulp stem cells (DPSCs) has been demonstrated by several studies showing that they appear to self-maintain through several passages, giving rise to a variety of cells. The aim of the present study was to differentiate DPSCs to mature neuronal cells showing functional evidence of voltage gated ion channel activities in vitro. First, DPSC cultures were seeded on poly-l-lysine coated surfaces and pretreated for 48h with a medium containing basic fibroblast growth factor and the demethylating agent 5-azacytidine. Then neural induction was performed by the simultaneous activation of protein kinase C and the cyclic adenosine monophosphate pathway. Finally, maturation of the induced cells was achieved by continuous treatment with neurotrophin-3, dibutyryl cyclic AMP, and other supplementary components. Non-induced DPSCs already expressed vimentin, nestin, N-tubulin, neurogenin-2 and neurofilament-M. The inductive treatment resulted in decreased vimentin, nestin, N-tubulin and increased neurogenin-2, neuron-specific enolase, neurofilament-M and glial fibrillary acidic protein expression. By the end of the maturation period, all investigated genes were expressed at higher levels than in undifferentiated controls except vimentin and nestin. Patch clamp analysis revealed the functional activity of both voltage-dependent sodium and potassium channels in the differentiated cells. Our results demonstrate that although most surviving cells show neuronal morphology and express neuronal markers, there is a functional heterogeneity among the differentiated cells obtained by the in vitro differentiation protocol described herein. Nevertheless, this study clearly indicates that the dental pulp contains a cell population that is capable of neural commitment by our three step neuroinductive protocol.

Fibronectin quantification without antibodies: a bioassay for the detection of the gelatin-captured macromolecule.

We have developed a new cell-adhesion-bioassay (CAA) for the quantitative determination of fibronectin in biological fluids. The assay is based on two particular properties of fibronectin: it specifically binds to gelatin with high affinity and simultaneously it can anchor to different surface molecules of a cell. First fibronectin, derived from very different biological fluids, is purified in situ, within the wells of the microtiter plates applied for the assay, using solid surface bound gelatin. After capturing the macromolecule, it is quantified based on its cell adhesive properties. In contrast to ELISA the CAA does not require specific antibodies, and as the Jurkat cells used as indicator cells, seem to recognize fibronectin from different species equally; species specificity of the reagent plays smaller, perhaps negligible, role in the determination of the amount of the macromolecule. The CAA method may not replace fibronectin specific ELISA-s, but using its principle, improved applications, for example a capture EIA for determining fibronectin can easily be envisioned and CAA may serve as a viable alternative for EIA-s when specific antibodies are not available or when relative measurement of not only the soluble but cell surface associated fibronectin is necessary.

Potency and specificity of the pharmacological action of a new, antiasthmatic, topically administered soft steroid, etiprednol dicloacetate (BNP-166).

In the present study, the pharmacological effects of etiprednol dicloacetate (BNP-166; ethyl-17alpha-dichloroacetoxy-11beta-hydroxyandrosta-1,4-diene-3-one-17beta-carboxylate), a new soft steroid, intended to use for the treatment of asthma, were investigated in an animal model of allergen sensitized and challenged Brown Norway rats using local treatment. The examinations involved the determination of the effect of the compound on the extent of allergen induced broncho-alveolar fluid and lung tissue eosinophilia, goblet cell hyperplasia and mucus production, perivascular edema formation, and airways hyperresponsiveness. The activity of etiprednol dicloacetate was compared with that of budesonide. Using in vitro methods, the soft character of etiprednol dicloacetate was investigated together with its capability to dissociate transrepressing and transactivating properties. We found that combining all the examined parameters etiprednol dicloacetate was at least equipotent with budesonide in the animal model, but in several investigated variables it surpassed the activity of budesonide. The effect of etiprednol dicloacetate in vitro was shown to be the function of the quantity of the serum, present in the assay, it was also strongly affected by the incubation time and decreased significantly when it was preincubated with human plasma. These features are characteristics of a soft drug that is quickly inactivated in the systemic circulation. In addition, it was revealed that while the transrepressing potential of etiprednol dicloacetate remained high, its transactivating activity was greatly reduced. These data indicate that the strong local effect of the compound will very likely be accompanied with a significantly reduced systemic activity predicting favorable selectivity in the pharmacological action of etiprednol dicloacetate.

Stage-dependent effects of cell-to-cell connections on in vitro induced neurogenesis.

NE-4C, a p53-deficient, immortalized neuroectodermal progenitor cell line, was used to investigate the role and importance of cellular interactions in neural commitment and differentiation. NE-4C cells give rise to neurons and astrocytes in the presence of all-trans retinoic acid, if they can establish intercellular contacts. Aggregation per se, however, was insufficient to induce large-scale neuron formation. In the absence of RA, the majority of the aggregated cells died. For neuron formation, therefore, concerted actions of RA and cellular interaction were needed. Electron microscopic and electrophysiological studies revealed that gap junctions were formed between the cells. Persistent blockage of communication via gap junctions with gap junction blockers, however, had no effects on neuron formation. If cell-to-cell connections were disrupted on the fourth day after induction, the rate of neuron production increased significantly. The contact interactions formed between already committed progenitor cells seemed to hinder the formation of novel neurons. The process resembled the phenomenon called "lateral inhibition" first observed in the course of neurogenesis in Drosophila. Our results indicate that NE-4C cells provide a useful model system to investigate the role of contact communication during some early steps of neurogenesis.

Changes of KCl sensitivity of proliferating neural progenitors during in vitro neurogenesis.

The effects of KCl-treatment on the survival and proliferation of NE-4C self-renewing neural progenitor cells were investigated during early phases of in vitro induced neurogenesis. NE-4C cells, derived from the anterior brain vesicles of embryonic mouse (E9), divided continuously under non-inducing conditions, but acquired neuronal features within 6 days, if induced by all-trans retinoic acid (RA). During the first 2 days of induction, the cells went on proliferating and did not show signs of morphological differentiation. In this stage, the resting membrane potential of RA-induced cells adopted more negative values in comparison to non-induced ones. Despite the increased membrane polarity and K+ conductance, addition of 20-50 mM KCl failed to elicit inward Na+ currents and did not induce an increase in the intracellular Ca+ level. Long-term treatment with 25 mM KCl, on the other hand, resulted in a selective loss of cells committed to neuronal fate by both decreasing the rate of cell proliferation and increasing the rate of cell death. The data indicate that the viability and proliferation of neural progenitors are influenced by extracellular K+-level in a differentiation stage-dependent manner.