Coronavirus pandemic and the Slovak medical faculties.

The Covid-19 pandemic has fully opened the debate on the complexity of the problem, which goes far beyond medical and epidemiological analyzes and proposals, although these are key to the decisions of leaders in the decisive sphere. Critical situations always force us to look for new methods. This is also indicated by paradigmatic changes in the overall functioning and position of medical faculties in Slovakia and abroad (1,2,3). The adaptation of the faculty administration at the time of this crisis is admirable in many respects and essential for the long-term societal struggle with the pandemic. (Ref. 3). Keywords: COVID-19, Coronavirus 2019, pandemic, public health, medical faculties in Slovakia.

Psychomotor performance and subjective symptoms at low level toluene exposure.

OBJECTIVES: Possible effects of long term occupational exposure to toluene below the level of 100 ppm on psychomotor performance and subjective symptoms were investigated in a cross sectional approach. METHODS: From German rotogravure printing plants 278 male workers, mean age 39.8 years, mean duration of employment 14.9 years, were examined. A mean lifetime weighted average exposure (LWAE) of 45.1 ppm toluene in ambient air was found for 154 exposed workers (rotogravure printing area), with a mean current exposure of 24.7 ppm. The corresponding data for a second group of 124 workers with very low exposure (endprocessing area) had LWAE of 9.3 ppm and a current exposure of 3.3 ppm toluene. Psychomotor performance (steadiness, line tracing, aiming, tapping, and peg board) and subjective symptoms were examined. RESULTS: No significant differences between the two exposure groups were found by analysis of variance (ANOVA). By stepwise linear regression analyses there were weak associations of LWAE with one performance variable and two symptoms scales, but the results were not significant after correction for the alpha error. Psychomotor performance was mostly affected by age (maximum explained variance up to 13%), and handedness (up to 9%), whereas subjective symptoms are mostly affected by anxiety (up to 38%). CONCLUSIONS: The weak associations between long term exposure to toluene should be used to indicate further longitudinal investigations. The results of this cross sectional study show no obvious dose response relation for psychomotor functions and subjective symptoms among workers exposed to toluene at a current exposure level of 1-88 ppm.

Subjective symptoms due to solvent mixtures, dioxin, and toluene: impact of exposure versus personality factors.

In this study, we analyse the impact of personality factors on the frequency of self-reported symptoms for workers under different exposure conditions. Reported symptoms may depend on the level and type of exposure, as well as on personality factors such as trait anxiety of the worker or his general sensitivity with regard to the environment. The employed data stems from three studies: The first study contains information of 60 workers who suspected to be exposed to polychlorined dibenzodioxins and dibenzofuranes (Lifetime Weighted Average Exposure, LWAE, as an index for contact with the substances). The second study concerns 40 workers who are exposed to different concentrations of solvent mixtures in paint manufacturing (LWAE of total hydrocarbons about 10 ppm). The third study includes repeated measurements of two subgroups of workers from rotogravure printing plants who are exposed to different concentrations of toluene: a "high" exposure group (n = 129, LWAE about 46 ppm, current exposure 25 ppm) and a "low" exposure group (n = 96, LWAE for toluene about 9 ppm, current exposure 3 ppm). Trait anxiety, environmental sensitivity, and self-reported symptoms are measured by validated questionnaires and age as well as verbal intelligence are controlled. To determine the effect of the individual characteristics and the different exposures on self-reported symptoms, frequency analyses and variance analyses are conducted and linear models are fitted. For all analyses, trait anxiety explains the highest share of the variance. If there is no effect of the exposure on the reported symptoms (dioxin and low-level toluene study), trait anxiety seems to have a larger explanatory power in comparison with those studies where the exposure has an effect on the reported symptoms (solvent-mixture and high-level toluene study). Neurotoxicological risk analysis has to account for the detected dependence of self-reported symptoms on personality traits: assessments for elevated symptoms should not only be linked to the intensity of exposure but also related to benchmarks derived from the normal variability of personality factors.

Association of biochemical and subjective indicators of drinking habits with performance on different neurobehavioral tasks.

The present paper outlines the association of biochemical and subjective indicators of alcohol consumption. Due to its relevance as a potential confounding variable in occupational neurotoxicology, both sources of information about drinking habits were related to neurobehavioral test performance. A sample of 308 rotogravure printers and control subjects from a cross-sectional longitudinal study in various German printing plants was studied. Duration of employment was 4 months to 44 years (mean = 14.9, sd = 9.67). Mean age was 38.4 years (range 21 - 60). From venous blood samples three parameters considered to be sensitive for increased consumption of alcohol were used. They were carbohydrate-deficient transferrin (CDT), gamma glutamyl transferase (GGT), and mean cell volume (MCV). During the medical interview subjects with any chronic liver disease were identified and excluded from data analysis. Additionally, information about weekly consumption of alcohol was assessed and transformed to grams per day (g/d) values. Neurobehavioral testing included simple reaction time (SPES version), switching attention, symbol digit substitution, and digit span (EURONEST version). Additionally, a questionnaire of neurotoxic complaints was administrated. Other covariates, i.e. verbal ability, history of solvent exposure, and age were controlled. GGT and CDT were elevated in 10.5% and 6.6% of the population. 3.5% of the subjects reported daily consumption higher than 60 gram. There were positive correlations of CDT and GGT with the subjective indicator of drinking habits. The magnitude of these relationships were low, but the associations were significant. MCV was not correlated with subjective reports of drinking habits, but it showed convergent correlations with CDT and GGT. Comparison of these two parameters with performance on neurobehavioral tasks yielded only one negative association, i.e. between the memory-loaded tasks factor and GGT. CDT and subjective estimation of alcohol consumption were not related to any cognitive function tested in this study. Especially, the digits-backward task was negatively correlated with increased GGT.

Proteinases of Trichomonas vaginalis: antibody response in patients with urogenital trichomoniasis.

Immunoprecipitation combined with electrophoresis in gelatin-polyacrylamide gels was successfully used for detection of antibodies against numerous proteinases of Trichomonas vaginalis in infected patients. The method proved to be highly specific as anti-proteinase antibodies were absent in women with negative cultivation of T. vaginalis and no history of trichomoniasis. Sera of 71% and vaginal washes of 86% patients with trichomoniasis were positive for these antibodies. In vaginal washes, but not in sera, antibodies were partly complexed with proteinases, possibly of trichomonad origin. It was also shown that serum antibodies as well as local anti-proteinase antibodies persisted for weeks after patients had been cured.

Vaginal leukocyte characteristics in urogenital trichomoniasis.

Morphological and functional characteristics of vaginal exudate leukocytes were examined in 47 patients with urogenital trichomoniasis. Electron microscopic morphology, viability, phagocytosis of Candida albicans blastospores and ability to undergo respiratory burst in the iodonitrotetrazolium reductase test were evaluated in these cells. Vaginal inflammatory leukocytes were almost exclusively polymorphonuclear neutrophils, and their concentration was positively correlated (r = 0.58; p less than 0.001) with the number of trichomonads in the exudate. Median leukocyte viability reached 39% and both phagocytic and tetrazolium reductase activities of these cells were significantly reduced in comparison with those of circulating polymorphonuclear leukocytes. Patients with a clinical picture of severe mucosal inflammation had significantly higher vaginal exudate leukocyte concentrations and viability than those without inflammatory signs. The possible role of vaginal leukocytes in the pathogenesis of urogenital trichomoniasis is discussed.

Proteinases in Trichomonas vaginalis and Tritrichomonas mobilensis are not exclusively of cysteine type.

High molecular weight proteinases of Trichomonas vaginalis (with apparent Mr values 142 and greater than 220 kDa) and Tritrichomonas mobilensis (Mr 67, 86, 104 and 120 kDa), optimally active at pH8, were analysed in gelatin-containing polyacrylamide gels. All of these proteinases were resistant to serine-, aspartic- as well as cysteine proteinase inhibitors. Both proteolytic bands in T. vaginalis and two proteinases in T. mobilensis (67 and 104 kDa) were inhibited by EDTA and EGTA suggesting that they belong to the metallo-proteinase class. The 67 kDa proteinase of T. mobilensis was inhibited also by o-phenanthroline. The other two bands of T. mobilensis (86, 120 kDa) were not classified to any proteinase group since they appeared to be resistant to the chelating agents tested in this study.

Cell-associated and extracellular proteolytic activity of an oral flagellate, Trichomonas tenax.

Proteolytic activities in crude extracts and culture filtrates from Trichomonas tenax were determined using hide powder azure as substrate and the proteinase profiles in both samples were analysed in SDS-polyacrylamide gels containing copolymerized gelatin. The enzyme activity in the crude extract was detected over a broad pH range and was strongly activated by dithiothreitol, mainly in the pH range 5-8, and inhibited by cysteine proteinase inhibitors. Extracellular enzyme activity in culture filtrates was SH-dependent and increased continuously during incubation of the cell suspension, suggesting proteinase release. A total of seven distinct proteolytic bands could be detected in crude preparations. Three of these, with apparent Mr values 35,000, 45,000 and 56,000 and a pH optimum of 4-7, were SH-dependent and their inhibitory sensitivities were characteristic for cysteine proteinases. The 45,000 and 56,000 proteinases probably corresponded to those found in the culture filtrates. Proteolytic bands with apparent Mr 76,000, 87,000, 102,000 and 270,000 and pH optima in the alkaline region, pH 8-9, were independent of SH groups and were inhibited by a chelating agent EDTA, suggesting that they belong to the metalloproteinase family.

Degradation of collagen types I, III, IV and V by extracellular proteinases of an oral flagellate Trichomonas tenax.

Proteinases secreted by an axenic strain of Trichomonas tenax were active against native types I, III, IV and V collagens when evaluated by polyacrylamide gel electrophoresis. Degradation of all four collagen types was temperature dependent. Basement membrane type IV collagen was digested most effectively. An inhibition of all collagenolytic activities by a specific inhibitor of cysteine proteinases, E-64, and activation by a reducing agent, dithiothreitol, indicated the involvement of cysteine proteinases of the oral flagellate in the cleavage of collagen.

Proteolytic activity in Tritrichomonas mobilensis.

Cell extracts of an entero-invasive protozoon of squirrel monkeys, Tritrichomonas mobilensis, contained relatively high proteolytic activity, measured on hide powder azure (HPA). Multiple proteinase forms, optimally active at pH 5-7, were detected by electrophoretic analysis in gelatin-containing polyacrylamide gels. Three major proteinase bands of apparent low molecular weights, Mr 18, 23 and 30 kDa, were seen on gels. Inhibition-activation studies suggest that only cysteine proteinases were involved in HPAase and gelatinolytic activities of T. mobilensis cell extracts.

[Urogenital trichomoniasis and vaginal mycosis in female offenders--a repeat study 20 years later]. / Urogenitálna trichomoniáza a vaginálna mykóza u delikventných zien--opakovaná stúdia po 20 rokoch.

The prevalence of urogenital trichomoniasis and vaginal mycosis in 698 female prison inmates in Bratislava was compared with the occurrence of the diseases recorded twenty years ago. The occurrence rate of urogenital trichomoniasis (40.97%) was only slightly reduced compared to the sixties (59.17%), yet it was still five times higher than in the current population. The occurrence rate of vaginal mycosis is much lower in delinquent women (2.3%) than in other women. Trichomonas vaginalis was most frequently present in the age group of 20-29 years (44.67%). All patients with urogenital trichomoniasis were cured with nitroimidazoles. The first treatment was successful in 98.25%, the second treatment with the same dose had a 100% efficacy. Repeated examination of 84 women after two months did not confirm the possibility of intramural infection.

[The occurrence of protozoa in the intestinal microflora of laboratory mice]. / Výskyt prvokov v crevnej mikroflóre laboratórnych mysí.

The intestinal content of 216 white SPF laboratory mice was examined for the presence of protozoa. 153 (70.8%) were found to be positive. The following protozoa species were determined: Trichomonas muris in 31.5%, Trichomonas sp. in 29.6%, Chilomastix becentourti in 18.5%, Octomitus intestinalis in 7.8%, Giardia muris in 6.9%, Spironucleus muris in 4.1%, and Entamoeba muris in 14.8%. The given species occurred in the mice either individually or, in the majority of cases, combined infections involving 2-5 species were recorded. Young mice transferred from the breeding station were but rarely colonized, and that only by a small number of protozoa. They contract infection from older animals in the animal room. (Tab. 3, Ref. 11.).

Adherence and surface properties of Tritrichomonas mobilensis, an intestinal parasite of the squirrel monkey.

Adherence properties of the potentially enteropathogenic Tritrichomonas mobilensis were studied in vitro. Axenically cultivated trichomonads readily attached to isolated intestinal epithelial cells and mucus of the squirrel monkey. The kinetics and nature of T. mobilensis cytadherence were microscopically evaluated in cell-suspension assay using Chinese hamster ovary (CHO) cells and in microplate hemagglutination assay with human erythrocytes. Adherence of the parasites to target cells was concentration- and time-dependent; it was inhibited by sialic acid (N-acetylneuraminic or N-glycolylneuraminic acid) and sialyllactose. Neither trypsinization of the flagellates nor their exposure to low temperature (4 degrees C) affected their cytadherence capacities. The data indicate the presence of adhesin(s) with lectin properties on T. mobilensis. Agglutination of live protozoa by animal and plant lectins with various carbohydrate-binding specificities as well as the occurrence of an electron-dense cell coat on plasma membrane suggest marked glycosylation of the parasite surface.

Specific parasitism of purified vaginal epithelial cells by Trichomonas vaginalis.

Human vaginal epithelial cells (VECs) from vaginal swabs obtained from normal women or from patients with trichomoniasis were purified, and VEC parasitism by Trichomonas vaginalis was examined. Trichomonads bound equally well to live or dead VECs, and up to 20% of VECs were parasitized. Trichomonal cytadherence of human VECs was time, temperature, and pH dependent. Saturation binding levels of live trichomonads to VECs gave approximately 2 organisms adherent to parasitized VEC. No differences in cytadherence levels were detected by different isolates to VECs from the same patient compared with adherence to VECs from normal individuals. Trypsinized, live T. vaginalis organisms failed to recognize VECs. A ligand assay identified four adhesin candidates, and only organisms without a prominent immunogen on the surface (negative phenotype) cytadhered to VECs and synthesized the adhesins, confirming the results of a recently published report by us on adherence to HeLa cell monolayers (J. F. Alderete and G. E. Garza, Infect. Immun. 56:28-33, 1988). These data show the ability of T. vaginalis to parasitize human vaginal epithelial cells in a specific receptor-ligand manner.

Differential susceptibility of fresh Trichomonas vaginalis isolates to complement in menstrual blood and cervical mucus.

The ability of complement in human menstrual blood and cervical mucus to kill Trichomonas vaginalis was compared with that of complement in serum, and 95 fresh trichomonal isolates obtained from vaginal wash material were evaluated for susceptibility to complement immediately after isolation. Only serum and menstrual blood with haemolytic activity produced total cytolysis of T vaginalis. The cytolytic abilities of these fluids were totally inactivated by treatment with heat or edetic acid (EDTA), which confirms the role of complement in cytolysis. Most cervical mucus samples had no detectable trichomonal cytotoxic properties. The cytotoxic activity in the remaining samples was not due to complement, as it was heat stable. Fresh isolates of T vaginalis and subpopulations of fresh isolates differed in their susceptibility or resistance to complement mediated lysis in serum. Resistance to complement did not remain stable after trichomonads were grown in vitro.

Fewer Trichomonas vaginalis organisms in vaginas of infected women during menstruation.

The aims of the present study were to count Trichomonas vaginalis organisms recovered from the vaginas of patients with trichomoniasis, and to obtain data concerning changes in sizes of trichomonal populations during the menstrual cycle. In about 80% of symptomatic as well as symptomless patients, more than 1 x 10(5) parasites per ml could be obtained from vaginal washes. During menstruation, however, the number of trichomonads decreased appreciably, with subsequent increases within three to six days after bleeding. The results indicated that sufficient numbers of fresh trichomonads may be obtained from vaginal washes for biochemical and molecular experiments and also confirm the previously reported trichomonocidal effect of menstrual blood complement in vivo.

Phenotypes and protein-epitope phenotypic variation among fresh isolates of Trichomonas vaginalis.

Fresh isolates of Trichomonas vaginalis were examined for reactions to a panel of five monoclonal antibodies (MAbs). Four MAbs (C20A3, DM126, DM116, and C55) were to distinct surface immunogens and one MAb (L64) was to a cytoplasmic component. The fresh isolates were evaluated by indirect immunofluorescence (IF), immunoblotting, and radioimmunoprecipitation. IF assay with C20A3 MAb gave isolates which were homogeneous nonstaining (negative [Neg] phenotype) and isolates which were heterogeneous staining and nonstaining (positive [Pos] and Neg phenotype, respectively) organisms. Immunoblotting and radioimmunoprecipitation assays revealed that surface phenotypic heterogeneity among isolates with C20A3 MAb was due to the presence or absence of the immunogen from the parasite surface. IF assay with DM126 MAb also gave Pos and Neg phenotypes among parasites of some isolates. All of the isolates were always Neg phenotype with DM116 and C55 MAbs. The occurrence of Neg phenotype organisms with DM126, DM116, and C55 was due to epitope inaccessibility to their respective MAbs and not to the absence of the immunogen from trichomonal membranes. All isolates possessed the cytoplasmic protein recognized by L64 MAb. Paired isolates (taken 5 to 6 days apart) from 24 women were also studied. Four of the 24 paired isolates (16%) had different phenotype distributions at the two timepoints for C20A3. Fresh isolates also underwent phenotypic variation during in vitro growth and multiplication, as determined with C20A3. Also, 7 of the 24 paired isolates demonstrated dramatic changes in the accessibility of DM126 MAb to epitope binding. Lastly, 55 (90%) of 60 serum samples from patients with trichomoniasis evaluated in this study possessed antibody to the C20A3 reactive molecule. The data show that the fresh T. vaginalis isolates were predominantly Neg phenotype and confirm the occurrence of protein and epitope phenotypic variation for major immunogens among fresh isolates of the pathogenic human trichomonads.

Immunotherapeutic effect of the lactobacillus vaccine, Solco Trichovac, in trichomoniasis is not mediated by antibodies cross reacting with Trichomonas vaginalis.

According to the producers of the lactobacillus vaccine, Solco Trichovac, its therapeutic effect in trichomoniasis is achieved by antibodies that are induced by the vaccination and cross react with Trichomonas vaginalis. Common antigens of Lactobacillus acidophilus from Solco Trichovac vaccine and T vaginalis were therefore sought by three different seroreactions. Immune serum against Lacidophilus obtained by vaccinating two healthy human volunteers and two rabbits with the original Solco Trichovac vaccine, as well as hyperimmune rabbit antiserum to T vaginalis, were tested with each of the two micro-organisms. No evidence of antigenic similarity between L acidophilus and T vaginalis was obtained with either serum in any of the three serological tests. A non-specific immunostimulatory effect therefore seems to be a more probable explanation of the mode of action of Solco Trichovac vaccine.