Cytokines and resistive breathing

The results of recent experimental studies indicating the involvement of the immune system in the control of breathing are analyzed and summarized. The hypothesis on the role of cytokines in the mechanisms of respiratory muscle fatigue and a decrease in the ventilatory sensitivity to hypercapnia during respiration with the added resistive load is justified. Possible ways of implementation of the respiratory cytokine effects are discussed.     

Heterogeneity of the Stearoyl-CoA desaturase-1 (SCD1) Gene and Metabolic Risk Factors in the EPIC-Potsdam Study

Background

Stearoyl-CoA desaturase-1 (SCD1) is an enzyme involved in lipid metabolism. In mice and humans its activity has been associated with traits of the metabolic syndrome, but also with the prevention of saturated fatty acids accumulation and subsequent inflammation, whereas for liver fat content inconsistent results have been reported. Thus, variants of the gene encoding SCD1 (SCD1) could potentially modify metabolic risk factors, but few human studies have addressed this question.

Methods

In a sample of 2157 middle-aged men and women randomly drawn from the Potsdam cohort of the European Prospective Investigation into Cancer and Nutrition, we investigated the impact of 7 SCD1 tagging-single nucleotide polymorphisms (rs1502593, rs522951, rs11190480, rs3071, rs3793767, rs10883463 and rs508384) and 5 inferred haplotypes with frequency >5% describing 90.9% of the genotype combinations in our population, on triglycerides, body mass index (BMI), waist circumference (WC), glycated haemoglobin (HbA1c), high-sensitivity C-reactive protein (hs-CRP), gamma-glutamyltransferase (GGT), alanine aminotransferase (ALT) and fetuin-A.

Results

No significant associations between any of the SNPs or haplotypes and BMI, WC, fetuin-A and hs-CRP were observed. Associations of rs10883463 with triglycerides, GGT and HbA1c as well as of rs11190480 with ALT activity, were weak and became non-significant after multiple-testing correction. Also associations of the haplotype harbouring the minor allele of rs1502593 with HbA1c levels, the haplotype harbouring the minor alleles of rs11190480 and rs508384 with activity of ALT, and the haplotype harbouring the minor alleles of rs522951, rs10883463 and rs508384 with triglyceride and HbA1C levels and GGT activities did not withstand multiple-testing correction.

Conclusion

These findings suggest that there are no associations between common variants of SCD1 or its inferred haplotypes and the investigated metabolic risk factors. However, given the results from animal models, heterogeneity of human SCD1 warrants further investigation, in particular with regard to rare variants.     

Variability of Vibrio cholerae as affected by subbacteriostatic concentrations of antibiotics

The effect of subbacteriostatic concentrations of some antibiotics on variation of the features characterizing the serovar and biovar of the cholera germ was studied on 10 strains of V. cholerae E1 Tor of the Inaba serovar having the typical properties. It was shown that even a single exposure to the subbacteriostatic concentrations of some antibiotics resulted in formations of clones differing from the parental strains by a number of significant features, such as the antigenic structure, phage lysability and enterotoxicity. The new features were inherited in a number of generations on multiplication in culture media and in sensitive animal hosts.     

Study of the evoked potentials to photic stimulation in man after deafferentiation of the visual cortex]

A study was made of evoked potentials (EP) in response to light stimulus in the occipital areas of the cortex in 28 patients with homonimous hemianopsia caused by focal affection of the optic system. EP asymmetry in the hemispheres was recorded only in case of complete homonimous hemianopsia. Reduction of response at the side of contralateral hemoanopsia was observed in affection of the optic tracts at the level of the optic cord and in case of spread of the pathological focus to the occipital lobe. In half of the cases of homonimous hemianopsia caused by affection of the optic radiation the responses were greater by amplitude at the side of the focus or were recorded only in the deafferentated occipital area.     

Dynamics of changes in the cerebral and erythrocyte ATPase activity of rats with hypoxic hypoxia]

A long-term (for 3 hours) hypoxic hypoxia was accompanied in rats by wave changes of the brain tissue Na++K+-ATPase activity. This activity decreased after a 15-minute exposure; it increased after 2 hours and fell again after a 3-hour hypoxia (decompensation period). The membrane transport enzymes of erythrocytes proved to be more resistant to hypoxia than the brain cell enzymes.     

Morpho-functional study of the brain of animals with different types of individual resistance to hypoxia

The experiments on white rats have shown that animals with distinct tolerance to hypoxia were characterized by individual metabolic changes in phylogenetically different brain structures. Adaptation to hypoxia in animals with high tolerance was associated with metabolic changes in the reticular formation and in animals with low tolerance with changes in the cerebral cortex. The experiments have shown that white rats with distinct individual tolerance to hypoxia are characterized by an inherent level of plastic metabolism in different brain structures. A correlation between brain tissue metabolism and individual tolerance of animals to hypoxia is suggested.     

Immunohistochemical and electron microscopic identification of the cells producing serotonin and prostaglandin F2 in the rat thymus

Using immunohistochemical and electron microscopic methods the presence of serotonin and prostaglandin F2 containing granules in some epithelial cells of rat thymus has been shown. The modulatory role of these hormones in the thymic immunocompetent cells production is discussed.     

Studies of Initial Stages of Biocorrosion of Steel

Initial stages of corrosion of mild steel induced by Klebsiela rhinoscleromatis BO2 were studied in various media. The effect of the microorganism was detected 8–10 h after inoculation. The number of viable cells was virtually unchanged over one month in all media, but the corrosive activity of the strain decreased. The corrosive activity of microorganisms can be determined by spectrophotometry even after incubation for only 24 h. At a low level of organic substrate, even strong colonization with microorganisms does not inevitably result in significant damage to metals.