Beta-adrenergic mechanism of the radio-protective effect of isoproterenol in a mammalian cell culture

A specific beta-agonist, isoproterenol, increased the intracellular content of cyclic AMP and decreased the radiosensitivity of Chinese hamster fibroblasts. Beta-antagonist, propranolol, blocked the manifestation of the effect of isoproterenol. Isoproterenol did not affect either the intracellular level of cyclic AMP or the radiosensitivity of B-82 cells which had no beta-adrenoreceptors.     

Risk Factors for Death in 632 Patients with Sickle Cell Disease in the United States and United Kingdom

Background

The role of pulmonary hypertension as a cause of mortality in sickle cell disease (SCD) is controversial.

Methods and Results

We evaluated the relationship between an elevated estimated pulmonary artery systolic pressure and mortality in patients with SCD. We followed patients from the walk-PHaSST screening cohort for a median of 29 months. A tricuspid regurgitation velocity (TRV)≥3.0 m/s cuttof, which has a 67–75% positive predictive value for mean pulmonary artery pressure ≥25 mm Hg was used. Among 572 subjects, 11.2% had TRV≥3.0 m/sec. Among 582 with a measured NT-proBNP, 24.1% had values ≥160 pg/mL. Of 22 deaths during follow-up, 50% had a TRV≥3.0 m/sec. At 24 months the cumulative survival was 83% with TRV≥3.0 m/sec and 98% with TRV<3.0 m/sec (p<0.0001). The hazard ratios for death were 11.1 (95% CI 4.1–30.1; p<0.0001) for TRV≥3.0 m/sec, 4.6 (1.8–11.3; p = 0.001) for NT-proBNP≥160 pg/mL, and 14.9 (5.5–39.9; p<0.0001) for both TRV≥3.0 m/sec and NT-proBNP≥160 pg/mL. Age >47 years, male gender, chronic transfusions, WHO class III–IV, increased hemolytic markers, ferritin and creatinine were also associated with increased risk of death.

Conclusions

A TRV≥3.0 m/sec occurs in approximately 10% of individuals and has the highest risk for death of any measured variable.

The study is registered in ClinicalTrials.gov with identifier

{"type":"clinical-trial","attrs":{"text":"NCT00492531","term_id":"NCT00492531"}}NCT00492531     

Visual mechanisms of recognition of vanishing figures

The acuity test Landolt C's with a complex contour imitating various kinds of high-pass spatial frequency filtering generated as a printed visual acuity charts with a grey background were studied with regard to recognition thresholds. Comparisons were made for recognition thresholds with different complex contours. When the vanishing optotypes are out of focus, their image on the retina fades rapidly into the grey background, rendering them invisible rather than merely blurred as in the standard chart. The data obtained confirm that the recognition distance depends on physical property of complex contour profile and show the importance of the Landolt C spatial frequency spectrum for recognition of different types of the complex contour.     

Receptor-mediated endocytosis and nuclear transport of a transfecting DNA construct

A soluble construct consisting of a plasmid carrying the gene of the SV40 large T-antigen and an insulin-poly-L-lysine conjugate is able to selectively transfect PLC/PRF/5 human hepatoma cells which possess insulin receptors. Transfection can be efficiently competed by excess free insulin. To examine intracellular transport of the construct, it was fluorescently labeled and its accumulation on and in cells visualized by video-enhanced microscopy and quantitative confocal laser scanning microscopy. After 2 h at 37 degrees C, the labeled construct was found predominantly in intracellular acidic compartments, with a substantial portion of fluorescence localized both near and in the cell nucleus. Binding, endocytosis, and nuclear localization of the labeled conjugate could all be competed by excess free insulin, thus indicating that entry of the conjugate into cells was specifically mediated by the insulin receptor.     

Photoperiodic reaction in the beet webworm Loxostege sticticalis L. (Pyraloidea, Crambidae) from eastern and western parts of its Eurasian range

The beet webworm, Loxostege sticticalis L., is a very dangerous polyphagous insect pest whose outbreaks periodically occur in southern Russia and northern China. The aim of our work was to describe the photoperiodic response of beet webworm populations from western (Krasnodar Territory and Rostov Province) and eastern [Buryatia and China (Hebei Province)] parts of the pest range. The insects were reared under constant photoperiods of 12–18 h and constant temperatures of 19–25°C. Incidence of diapause at different photoperiods did not show any considerable geographic differences, and the critical day length at which 50% of prepupae arrested their development was about 14–15 h in all the populations studied at experimental temperatures. The results obtained agree with the hypothesis on the existence of an area (or areas) where the pest survives during adverse periods and wherefrom it spreads when an outbreak begins (Saulich et al., 1983; Goryshin et al., 1986). Presumably, the larger part of the pest native habitats (to the north of the steppe zone) is occupied by temporary populations, incapable of surviving for long periods without an inflow of migrants from more southerly steppe regions.     

Antitumor efficacy of Auger electron emitter <Superscript>111</Superscript>In delivered by modular nanotransporter into the nuclei of cells with folate receptor overexpression

A new modular nanotransporter (MNT) for the delivery of anticancer agents into the nuclei of cells with folate receptor overexpression was created. An effective method for acceding labeling of this MNT with Auger electron emitter ¹¹¹In has been developed. A significant therapeutic effect was observed after a single intratumoral injection of the new ¹¹¹In-labeled MNT to mice grafted with human cervical carcinoma characterized by folate receptor overexpression.     

Comparative antibiotic sensitivity of different species of staphylococci isolated from humans]

A total of 206 strains of various staphylococcal species isolated from various sources were studied with respect to their sensitivity to 18 antibiotics. The number of strains poly-resistant to the antibiotics was almost the same among Staph. aureus and Staph. epidermidis, i. e. 54.8 and 51.3 per cent respectively. The coagulase-negative and mannitol-negative variants of Staph. aureus and Staph. epidermidis possessing high biological activity (10-14 properties) were resistant to more antibiotics as compared to the low active strains.