Labile assembly of a tardigrade protein induces biostasis.

Tardigrades are microscopic animals that survive desiccation by inducing biostasis. To survive drying tardigrades rely on intrinsically disordered CAHS proteins, which also function to prevent perturbations induced by drying in vitro and in heterologous systems. CAHS proteins have been shown to form gels both in vitro and in vivo, which has been speculated to be linked to their protective capacity. However, the sequence features and mechanisms underlying gel formation and the necessity of gelation for protection have not been demonstrated. Here we report a mechanism of fibrillization and gelation for CAHS D similar to that of intermediate filament assembly. We show that in vitro, gelation restricts molecular motion, immobilizing and protecting labile material from the harmful effects of drying. In vivo, we observe that CAHS D forms fibrillar networks during osmotic stress. Fibrillar networking of CAHS D improves survival of osmotically shocked cells. We observe two emergent properties associated with fibrillization; (i) prevention of cell volume change and (ii) reduction of metabolic activity during osmotic shock. We find that there is no significant correlation between maintenance of cell volume and survival, while there is a significant correlation between reduced metabolism and survival. Importantly, CAHS D's fibrillar network formation is reversible and metabolic rates return to control levels after CAHS fibers are resolved. This work provides insights into how tardigrades induce reversible biostasis through the self-assembly of labile CAHS gels.

[Cardiovascular risk factors in patients with ulcerative colitis].

BACKGROUND: Given the current trends in increasing the life expectancy of patients with ulcerative colitis (UC), the study of the risk of atherothrombotic events in them requires study. For effective prevention of cardiovascular diseases, it is necessary to assess cardiovascular risk factors since the concept of their timely detection is the basic one when planning preventive measures. AIM: To assess the prevalence of cardiovascular risk factors in patients with UC. MATERIALS AND METHODS: One hundred eighty four UC patients participated in the case-control study; 56 participants were included in the control group. The studied parameters are unmodified, behavioral, and biological factors of cardiovascular risk. The study participants were surveyed, examined, measured blood pressure, height, weight, the level of total cholesterol was studied, and the lipid spectrum was analyzed in 80 patients with UC. Parametric and nonparametric statistical methods were used. RESULTS: UC patients consumed fruit less often, drank tea and coffee with sugar more often, exercised less often and experienced high levels of stress. A higher incidence of arterial hypertension in UC patients was established, even though the fact of taking glucocorticosteroids was considered. No significant differences were found in the assessment of relative and total cardiovascular risk. CONCLUSION: Risk management of cardiovascular diseases in UC patients should focus on a personalized approach and timely screening of modifiable cardiovascular risk factors with their subsequent correction. The absence of significant differences in the level of relative and total cardiovascular risk indicates a limited contribution of traditional risk factors to the development of cardiovascular diseases in UC patients.

Overall bioburden by total colony count does not predict the presence of pathogens with high clinical relevance in hospital and community environments.

BACKGROUND: Healthcare-associated infections (HAIs) affect millions of patients, increasing morbidity and mortality. Pathogens of HAIs originate from both the patient's own flora and the environment, including multi-drug-resistant organisms. AIMS: To determine the bioburden on different types of high-touch surfaces, and to identify cultures to species level and stratify strains into those of low and high clinical relevance. DESIGN: Association between bioburden and presence of pathogens of high clinical relevance (PHCR) in a tertiary care centre and urban environment. METHODS: The overall bioburden measured by total colony count (TCC) was assessed using tryptic soy agar contact plates and two selective agars to improve detection of PHCR. Isolates were routinely identified to species level using matrix-assisted laser desorption/ionization - time of flight mass spectrometry (MALDI-TOF). The definition of PHCR was based on listings outlined by the Centers for Disease Control and Prevention. FINDINGS: In total, 1431 contact plates were processed from 477 surfaces: 153 from hospitals and 324 from publicly accessible institutions or devices. At least one PHCR was identified from cultures from 73 samples. TCC was found to be poorly correlated with the presence of PHCR. CONCLUSION: TCC poorly predicted the presence of PHCR, rendering the results from environmental sampling difficult to interpret. MALDI-TOF enables the identification of large numbers of isolates from the environment at low cost. Further studies on environmental contamination should use MALDI-TOF to identify all pathogens grown.

Molecular Targets of the Hydrophobic Block of Pluronics in Cells: a Photo Affinity Labelling Approach.

PURPOSE: Pluronics are known as inhibitors of multidrug resistance thus making tumor cells sensitive to therapeutic doses of drugs. The purpose of our study consists in revealing molecular targets of the hydrophobic poly(propylene oxide) block of pluronics in living cells and the dependence of the polymers chemosensitizing efficiency upon targeting. METHODS: A photo sensitive tracer was attached to the hydrophobic poly(propylene oxide) block of 3H-labeled tert-Bu-EO-PO copolymer. The conjugate was used for treatment cells in culture. We searched for its complexes with cellular lipids or proteins using RP TLC and SDS-electrophoresis, respectively. The chemosensitizing efficiency of pluronics was evaluated by their least concentrations sufficient for MDR reversion (CMDR). RESULTS: The poly(propylene oxide) block inserts in the lipid core of plasma membrane. No preferential binding of the conjugate with any cellular protein, particularly P-gp, has been detected. FITC-labeled pluronic L61 bound to alcohol insoluble cellular targets did not participate in MDR reversion. CMDR values of 13 block copolymers have been determined. These values inversely correlated with the polymers affinity toward lipids and the ability to accelerate flip-flop. CONCLUSION: Insertion of the hydrophobic poly(propylene oxide) block of amphiphiles in the lipid core of plasma membrane and acceleration of flip-flop of lipids underlie the mechanism of MDR reversion.

[Gastroduodenal mucosa sensitivity to estrogen in ulcers complicated by hemorrhage].

Expression of alpha-receptors of estrogen (RE) in accordance to immunohistochemical (IHC) labeling in gastroduodenal mucosa cells was studied up in patients, suffering the ulcer disease and without it. In 4 patients (group I) a gastroduodenal mucosa affection was revealed, they were operated on for hemorrhage from gastroduodenal ulcers; in 3 patients (group II) gastroduodenal mucosa affection was not observed; in 4 patients (group III, control), a mammary gland cancer was diagnosed, a positive reaction on alpha-RE was noted. In groups I and II the biopsies were studied, obtained from pylorus and gastric fundus, as well as from duodenal ampula, and in a group III--obtained from the tumor. In a control group a positive labeling of nuclei was revealed in biopsies. In patients of groups I and II the alpha-RE expression by cellular nuclei was not revealed, but, the lots of positive IHC labeling of cytoplasm in glandular and stromal mucosal cells of the investigated gut were noted. Positive IHC labeling of cytoplasm for alpha-RE witnesses about sensitivity to them in norma and pathological processes. But, a trustworthy difference of alpha-RE expression by cellular nuclei was not noted. For confirmation or denial of this hypothesis further clinical and IHC investigations are needed.

[HORMONAL-GENETIC SCREENING IN PATIENTS, SUFFERING GASTRODUODENAL ULCER HEMORRHAGE].

Genetic-hormonal regulation plays a key pathophysiologic role in a blood loss on background of complicated gastroduodenal ulcer disease, but a clinical significance of some genes of compensatory steroidogenesis remains unrevealed. Examination of 63 patients, using a chain reaction with polymerase (CRP); analysis of length of restriction fragments (CRP-RFLP) and immunohistochemical investigation of gastroduodenal mucosa were performed on the base of a Sumsky Rural Clinical Hospital. Trustworthy difference of distribution of polymorphic genes ESR1 and VKORC1 in patients of both gender in presence of the ulcer hemorrhage was not revealed, excluding genotype A/A VKORC1, what trustworthy more frequently was revealed in women (p < 0.05). There was established, that intact zone of gastric fundus owes immunoreactivity towards alpha-receptors of estrogen in nuclei of epitheliocytes and stromocytes. Diagnosis of polymorphic gene VKORC1 and expression of the estrogen receptors may serve the base for pathogenetic therapy in patients with hemorrhage occurrence.

Rare case of pathological biomineralization of eye tissue.

The authors have described the case of pathological biomineralization of ocular posterior chamber. Histological examination of affected eye shells revealed inflammation, oedema, dyscirculatory violations, and signs of dystrophic calcification. Structural-phase and chemical analyses of calcification have revealed that the biomineral consists of hydroxyapatite with relatively small crystallite size and defective crystal lattice. In the described case the formation of pathological biomineral in the vision organ was initiated by penetrating wound. Eye injury might have caused a hemophthalmus and chronic inflammatory reaction in the shells, these processes eventually led to the organ subatrophy and to the development of dystrophic and necrobiotic changes in the tissues. Pathological biomineralization in the affected organ developed as a type of dystrophic calcification.Key words: eye, pathological biomineralization, hydroxyapatite.

Morphogenetic aspects of biomineralization on the background of benign prostatic hyperplasia.

Despite the considerable spread of pathological prostate inclusions their nature and significance in the development of gland pathology are not established exactly. The work includes histological research of 628 surgical biopsies of benign prostatic hyperplasia, the sections were stained with hematoxylin and eosin or Congo red, von Kossa methods. Mineral constituent of prostatoliths (5 cases) was studied by infrared spectroscopy (IRS); scanning electron microscopy with X-ray microanalysis (REMMA/EDX), transmission electron microscopy and electron diffraction (TEM/ED). The average age of the operated patients was 69,5±0,42 years old. In 88,22±1,67% of cases nodular prostatic hyperplasia was combined with diffuse or focal inflammation, engorgements of prostate gland secretion were observed in 81,76±2,97%. In the lumen of the prostate gland corpora amylacea were detected in 64,72±1,13% of cases, in 27,6±3,48% - concreations. There was a significant strong correlation between inflammation and calculi - r = 0.93 (p<0,05), inflammation and secret engorgement - r=0,95 (p<0,05), engorgement and concreations - r = 0,88 (p <0,05). TEM results show the same morphological type of prostatolith crystals and their small size (tens of nanometers), that indicates their preferential formation by direct sedimentation from the liquid phase, rather than the appearance and maturation of corpora amylacea on the surface. Based on the received data, the dominant mechanism of concrements formation is precipitation by direct sedimentation of prostate secretions, but it's not a dystrophic calcification of the corpora amylacea. Mineral component of prostatic concrements is carbonate bioapatite with a minor inclusion of other chemical elements.

Medical discourse in pathological anatomy.

The paper is devoted to the peculiarities of medical discourse in pathological anatomy as coherent speech and as a linguistic correlate of medical practice taking into account the analysis of its strategies and tactics. The purpose of the paper is to provide a multifaceted analysis of the speech strategies and tactics of pathological anatomy discourse and ways of their implementation. The main strategies of medical discourse in pathological anatomy are an anticipating strategy, a diagnosing strategy and an explaining one. The supporting strategies are pragmatic, conversational and a rhetorical one. The pragmatic strategy is implemented through contact establishing tactics, the conversational one - with the help of control tactics, the rhetorical one - with the help of attention correction tactics. The above mentioned tactics and strategies are used in the distinguishing of major, closely interrelated strategies: "the contact strategy" (to establish contact with a patient's relatives - phatic replicas of greeting and addressing) and "the strategy of explanation" (used in the practice of a pathologist for a detailed explanation of the reasons of a patient's death). The ethic aspect of speech conduct of a doctor-pathologist is analyzed.

Intrafollicular pressure of colloid thyroid gland determinate the type of folliculogenesis.

The problem of colloid pressure of influence on the thyroid gland folliculogenesis is not clear enough in the scientific literature. The purpose of this study was to investigate the mechanism of folliculogenesis in the thyroid gland under the influence of salts of heavy metals combinations on the organism. The research was conducted on 24 white adult rats. To study the dynamics of morphological changes animals were removed from experiments on 30 and 60 days. Based on the theory of thin shells and the results of morphometric study of both groups of adult rats, which were influenced by a combination of heavy metal salts, the mathematical model to determine the level of tension in the wall of follicles was deduced. As a result of the influence of combinations of heavy metal salts on the follicular apparatus thyroid hypoactivity developed, which manifested in accumulating colloid and changing its tinctorial, physical and chemical properties, reducing the height of follicular epithelium, follicles increase in diameter, which also reflected the increasing tension in the wall of the follicle. Thus, the results allow to conclude that there is a significant role of intrafollicular colloidal pressure on the process of folliculogenesis. It is determined that in the wall of the elliptic form follicle higher tension arises in longitudinal section of the ellipse, and in cross-section the tension decreases. Analyzing the research results, we can assume that the difference between peripheral and central folliculogenesis occurs because of different amounts of intrafollicular pressure, which again are derived from different functional activity of the follicular epithelium.

Effect of veratridine on the release of neurotrophic factors in nerve tissue cultures.

The depolarizing agent veratridine was shown to affect the level of neurotrophic substances in combined cultures of neonatal rat hippocampus and chick embryo spinal ganglia. In this experimental model, the level of neurotrophic factors in rat hippocampus explants increased as a result of increases in neuronal activity mediated by veratridine. The effects of these neurotrophins on neurite growth in the sensitive spinal ganglion neurons in the combined cultures were evaluated using morphometric methods. Neurite-stimulating effects were seen when veratridine was added to the nutritive medium at a concentration of 90 nM. Antibody to nerve growth factor blocked the action of veratridine. These results demonstrate a role for neuron activity as a regulatory mechanism controlling the expression of neurotrophins.

Effect of cerebral neurite-stimulating protein on morphogenesis of organotypical culture of spinal ganglia.

We have extracted a cationic protein with a molecular weight of 15,000 kdalton from the hemispheres of rat and bovine brain. Addition of the protein to the nutrient medium of the organotypical culture of chick embryo spinal ganglia results in a considerable (2-2.5 fold) increase in the growth zone of the explants. The neurite-stimulating effect of the protein is observed at a concentration of 10 ng/ml. We observed an intensive longitudinal growth of neurites, an increase in their amount per unit area, a considerable intensification of ramification, and formation of strong anastomoses, numerous dense plexuses, and arcades. Fasciculi of neurites covered with glia are formed. The cerebral neurite-stimulating protein is evidently one of the neuron-growth factors regulating development of the nervous system in the body.