Effect of concanavalin A on the level of sulfhydryl groups in thymocytes

Fluorescein mercury acetate (FMA), a fluorescent probe, is used for the investigation of SH-groups of thymocytes' plasma membrane. It is found that mitogenic lectin Con A decreases the amount of membrane SH-groups and increases the fluorescence polarization degree of FMA (PFMA). The value of PFMA increases also during the incubation of cells with potassium ferricyanide and H2O2 but it decreases in the presence of NADH. The analysis of the data permits a conclusion that the thymocyte activation by Con A results in the selective oxidation of certain SH-groups with the formation of disulphide cross-linking between the plasma membrane receptors bound with the lectin molecules.     

Modifying effect of deep hypoxia on neutron-irradiated mice

Deep hypoxia was shown to influence the survival of animals, the state of the small intestine mucosa and the haemopoietic system. DMF (LD50/30) was 2.49 and 1.66 with X- and neutron radiation, respectively. As to haemopoietic stem cells X-irradiated in vivo, D0 was 0.96 +/- 0.04 Gy (control) and 2.82 +/- 0.14 Gy (anoxia). With neutron irradiation, D0 was 0.44 +/- 0.01 Gy and 0.8 +/- 0.03 for the control and experimental animals respectively.     

Effect of neurotensin on pancreatic function in man

The effect of neurotensin on submaximally-stimulated hepatobiliary and pancreatic secretion was studied in 6 healthy subjects. An intravenous infusion of neurotensin 1.4 ± 0.3 pmol/kg/min, designed to reproduce plasma neurotensin immunoreactivity levels within the physiological range, produced a significant increase in pancreatic bicarbonate output. Plasma concentrations of pancreatic polypeptide rose by 83 ± 16 pmol/l and were associated with a small reduction in trypsin, but no significant change in bilirubin outputs.     

Fine mechanisms of the interaction of silver nanoparticles with the cells of Salmonella typhimurium and Staphylococcus aureus

Silver nanoparticles possess antibacterial effect for various bacteria; however mechanisms of the interaction between Ag-NPs and bacterial cells remain unclear. The aim of our study was to obtain direct evidence of Ag-NPs penetration into cells of Gram-negative bacterium S. typhimurium and Gram-positive bacterium S. aureus, and to study cell responses to Ag-NPs. The Ag-NPs (most 8–10 nm) were obtained by gas-jet method. S. typhimurium (7.81 × 10⁷ CFU), or S. aureus (8.96 × 10⁷ CFU) were treated by Ag-NPs (0.05 mg/l of silver) in orbital shaker at 190 rpm, 37 °C. Bacteria were sampled at 0.5, 1, 1.5, 2, 5 and 23 h of the incubation for transmission electron microscopy of ultrathin sections. The Ag-NPs adsorbed on outer membrane of S. typhimurium and cell wall of S. auereus; penetrated and accumulated in cells without aggregation and damaging of neighboring cytoplasm. In cells of S. aureus Ag-NPs bound with DNA fibers. Cell responses to Ag-NPs differed morphologically in S. typhimurium and S. aureus, and mainly were presented by damage of cell structures. The cytoplasm of S. aureus became amorphous, while S. typhimurium showed lumping and lysis of cytoplasm which led to formation of “empty” cells. Other difference was fast change of cell shape in S. typhimurium, and late deformation of S. aureus cells. The obtained results showed how different could be responses induced by the same NPs in relatively simple prokaryotic cells. Evidently, Ag-NPs directly interact with macromolecular structures of living cells and are exert an active influence on their metabolism.     

Characterization and the broad cross‐species applicability of 20 anonymous nuclear loci isolated from the Taiwan Hwamei (Garrulax taewanus)

We isolated 20 anonymous nuclear loci (8556 bp in total) from the Taiwan Hwamei (Garrulax taewanus), an endemic songbird of Taiwan. A panel of nine to 15 individuals with unknown relationship was used to characterize polymorphism of these loci. We identified 46 single nucleotide polymorphic sites (SNPs) in 15 polymorphic loci. Frequency of SNPs was one per every 186 bp in average. Nucleotide diversity, θ, ranged from 0.00054 to 0.00371 per locus. We also tested cross‐species applicability of these loci on 17 species from eight different passerine families. All 20 loci could be successfully amplified (ranged from one to 16 species, mean = 7.9 species).     

Effect of low-intensity He-Ne laser irradiation on rat mesenteric microcirculation

Changes in microcirculation during low-intensity He-Ne laser irradiation were studied by measurement of blood vessels and lymphangions' diameter in anesthetized rat mesentery using method of videomicroscopy in vivo. We demonstrated that the red coherent light induced a significant increase in contractility of vessels' smooth muscle cells. The flow decreased in the mesenteric microvessels during H2O2-mediated oxidant stress was restored after He-Ne laser irradiation.