Biomarkers of toxicity in Clarias gariepinus exposed to sublethal concentrations of polycyclic aromatic hydrocarbons

Physiological, biochemical and histological indices in Clarias gariepinus broodstock, and teratogenic indices in embryos exposed to sublethal concentrations of naphthalene, phenanthrene and pyrene were investigated in 2014 using a static-renewal bioassay protocol. Phenanthrene (1.41 mg l^?1) was the most toxic, followed by pyrene (1.53 mg l^?1) and naphthalene (7.21 mg l^?1), based on 96 h LC50 values. Hepatosomatic indices were significantly higher in naphthalene- and pyrene-treated males compared with solvent controls, whereas fecundity in females was significantly lower by factors of 2.4 (naphthalene), 2.8 (phenanthrene) and 2.4 (pyrene), compared with controls. Catalase levels were lower in female phenanthrene-treated fish compared with controls. Histological alterations observed in PAH-treated fish include oedema, inflammatory cells, epithelial lifting and hyperplasia in the gills, vacuolation, haemosiderin pigments and sinusoidal congestion in the liver, and degenerated zona radiata in the ovary. Teratogenic effects were not observed, as evidenced by the lack of histological alterations in embryos spawned from pre-exposed broodstock. Sex-specific responses and the utility of biomarkers at cellular and individual levels of organisation are therefore demonstrated for holistic evaluations of polycyclic aromatic hydrocarbons in ecotoxicological studies.     

Microbiological aspects of enteric dysbacteriosis in patients of different age groups, visiting outpatient clinics of Moscow

The analysis of the intestinal microflora in 2,378 patients of different age revealed changes in the state of enteric microflora in all examined patients. In the maximum percent of cases a decrease in the amount of bifidobacteria was observed in children of up to 1 month old and in the amount of lactobacilli, in children aged 6 - 14 years. In patients of all age groups the representatives of such facultative microflora as Staphylococcus aureus or fungi of the genus Candida dominated. The highest proportion of isolated staphylococci was characteristic of children in the first year of life. In the highest percent of cases a decrease in the amount of Escherichia coli with typical properties was observed in persons over 65 years old. Other enterobacteria were most often isolated from adults aged 56 - 65, but the percentage of their isolation was 1.5 times lower than that of Candida. The conclusion was made that the treatment of patients with quantitative and qualitative disturbances of normal enteric microflora needed individual approach in each concrete case with due regard to the patient's age.     

Herpetomonas roitmani (Fiorini et al., 1989) N. Comb.: A Trypanosomatid with a Bacterium-like Endosymbiont in the Cytoplasm

The trypanosomatid previously described as Crithidia roitmani is characterized here at the ultrastructural and biochemical levels. The data indicates that the parasite belongs to the Herpetomonas genus, and we therefore suggest the flagellate to be denominated as Herpetomonas roitmani n. comb. Cladistic analysis of isoenzyme data generated by eight different enzymes showed that the parasite presented a distinct banding pattern and could be grouped with some Herpetomonas spp., but not with Crithidia spp., used as reference strains. Accordingly, when the parasites were grown for longer periods in Roitman's defined medium, expontaneous differentiation from promastigotes to opisthomastigotes (typical of the Herpetomonas genus) occurred. Transmission electron microscopy revealed the presence of bacterium-like endosymbionts in the cytoplasm of all evolutive forms of the parasite. All morphological alterations characteristic of endosymbiont-bearing trypanosomatids could be observed.     

Certain problems in developing the Automated Control System for the "Sanitary-Epidemiologic Service" of the Uzbek SSR

The main difficulties of using the subsystem "Records, Accounts and Analysis of Morbidity in Infectious Diseases", developed by the Republican Information and Computing Center of the Ministry of Health of the Byelorussian SSR for integration into the automated control system, under conditions of the Uzbek SSR lied in the fact that the number of the coupons of Recond Forms 171-BM for computers, several times exceeding that used in the Byelourssian SSR, had to be previously handled manually and in a short time.     

Effect of dye quality and the method of preparing a Schiff reagent on the staining intensity and DNA-fuchsin absorption spectra in performing the Feulgen reaction

Dependence of the staining and absorption spectra of DNA-fuchsin on the dye quality and modes of preparation of the Schiff-reagent was studied. It is shown that many dyes supplied by different producers do not suit the purposes of quantitative cytochemical investigations. Before use the absorption spectra of the DNA-fuchsin must be taken using the standard object. The use of dyes possessing a multi-peak absorption curve should be avoided.     

Multidrug resistance p-glycoprotein inhibits the antiapoptotic action of mitochondria-targeted antioxidant SkQR1

Mitochondria-targeted antioxidants of the SkQRI family, being accumulated in energized mitochondria, protect cells from oxidative stress by increasing the level of reduced glutathione and decreasing the cell-damaging effect induced by hydrogen peroxide. Using various human transformed cell lines and SkQR1 (a fluorescent member of the SkQ family), we show that SkQR1 is ejected from chemotherapy-resistant cells by P-glycoprotein--one of the main transport proteins determining multidrug resistance typical for many neoplastic cells. It is also shown that SkQR1 ejection is neutralized by P-glycoprotein inhibitors (verapamil and pluronic L61). In experiments on K562 cells, it was found that the subline sensitive to chemotherapy is protected by SkQR1 from apoptotic action of hydrogen peroxide. Protection of the resistant subline occurs only after inhibition of P-glycoprotein.     

Antibiotic resistance and putative origin of Staphylococcus aureus and Klebsiella strains isolated from the children with intestinal dysbacteriosis

The results of the statistical treatment of data on the analyses of 766 children, the residents of Moscow, for dysbacteriosis are presented; of these children, 34 were aged up to 1 month and 732, from 1 month to 1 year. This study revealed that in the fist year of life in children with dysbacteriosis the dominating bacterial species were S. aureus, bacteria of the genus Klebsiella and fungi of the genus Candida. From the intestine of children aged up to 1 month S. aureus and Klebsiella were isolated more often than from children aged up to 1 year. The results of the study of antibioticograms demonstrated that 21.6% of S. aureus strains and 74.4% of Klebsiella strains were multiresistant to antibiotics. Taking into account the fact that multiresistance to antibiotics was characteristic of hospital strains, the suggestion was made that the isolated strains were of hospital origin and such strains could colonize the intestine of children in maternity hospitals.     

<Emphasis Type="Italic">Staphylococcus simulans</Emphasis> recombinant lysostaphin: Production,purification, and determination of antistaphylococcal activity

Staphylococcus simulans lysostaphin is an endopeptidase lysing staphylococcus cell walls by cleaving pentaglycine cross-bridges in their peptidoglycan. A synthetic gene encoding S. simulans lysostaphin was cloned in Escherichia coli cells, and producer strains were designed. The level of produced biologically active lysostaphin comprised 6-30% of total E. coli cell protein (depending on E. coli M15 or BL21 producer) under batch cultivation conditions. New methods were developed for purification of lysostaphin without affinity domains and for testing its enzymatic activity. As judged by PAGE, the purified recombinant lysostaphin is of >97% purity. The produced lysostaphin lysed cells of Staphylococcus aureus and Staphylococcus haemolyticus clinical isolates. In vitro activity and general biochemical properties of purified recombinant lysostaphin produced by M15 or BL21 E. coli strains were identical to those of recombinant lysostaphin supplied by SigmaAldrich (USA) and used as reference in other known studies. The prepared recombinant lysostaphin represents a potential product for development of enzymatic preparation for medicine and veterinary due to the simple purification scheme enabling production of the enzyme of high purity and antistaphylococcal activity.