Antibiotic AL-87 induction of changes in the fatty acid composition of phospholipids and neutral lipids in a sensitive strain of Staphylococcus aureus 209P

Under the action of the sub-bacteriostatic concentration (0.02 microgram/ml) of antibiotic AL-87 there formed in all the fractions of phospholipids and neutral lipids of S. aureus 209P unsaturated branched fatty acids not detected in the control and the content of shorter chain saturated branched fatty acids increased. This means that there were changes leading to increased lipid fluidity. The findings showed that fatty acids of the neutral lipids and phospholipids were involved in regulation of the bacterial cell functional state and participated in this case in providing increased membrane fluidity and permeability.     

Nature of the IR spectra of intact cells of Gram-negative microorganisms

The character of changes in the infrared spectra of E. coli in the process of their mechanical disintegration has been studied. The destruction of E. coli cell structures has been shown to produce no changes in the optical density of the main analytical absorption bands in infrared spectra. This fact suggests that the infrared absorption spectra of E. coli are the sum of the spectra of all chemical components of the cell, which is confirmed by the infrared spectral study of E. coli cell-wall preparations. Similar results have been obtained in the study of the preparations of B. pertussis cell walls, protoplasts and intact cells.     

Cladocera (Crustacea) from Nicaragua

Thirty-one Cladocera taxa are recorded from lakes, rivers and ponds of Western Nicaragua. They include Alona bromelicola sp. nov. found in water accumulations in epiphytic Bromeliads. The Cladocera recorded are neotropical and circumtropical. Other invertebrates found are also listed.     

Formation of nanostructures in a plasma focus discharge

A new method for creating nanostructures in a plasma focus discharge is proposed. It is shown that the material of a micron-size dust target produced at the discharge axis efficiently evaporates and is then involved in the pinching process. After the pinch decays, the plasma expands with the thermal velocity and the evaporated dust material is deposited on the collectors in the form of fractal particles or nanoclusters organized into various structures. Such structures have a well-developed surface, which is important for various technological applications.     

An alpha class glutathione S-transferase from pike liver

Glutathione S-transferase (GST) was isolated from the Esox lucius liver and purified to the homogenous state by SDS-PAGE and isoelectrofocusing. It was found to be a homodimer with a subunit molecular weight of 25235.36 Da (HPLC-MS/MS data) and pI of about 6.4. Its substrate specificity, thermal stability, some kinetic characteristics, and optimum pH were studied. The enzyme was identified as Alpha class GST.     

3-O-methoxyimino group inhibits interactions between progestins and blood transcortin

The interactions between E- and Z-isomers of 3-O-methoxyimino-pregn-4-ene-20-one and its 17α-hydroxy derivative and transcortin from human blood were investigated. The substitution of the progesterone 3-oxo group for a 3-O-methoxyimino group was shown to diminish the affinity of the steroid for transcortin by approximately one order of magnitude irrespective of the substituent’s orientation. The data suggests that progesterone derivatives substituted thereby must have higher bioavailability compared to progesterone and must not significantly affect the biodynamics of glucocorticoid in vivo.     

Hypoxia during mammalian preimplantation development: Extreme circumstance vs. typical environment

The given paper summarizes the data on the early mammalian embryo development in culture media containing low oxygen concentration. Experimental results on in vitro modeling the hypoxia for preimplantation development are reviewed. Hypoxic conditions were shown to be available in the female reproductive tract of different mammalian species. The estimation of the embryo developing in vitro exhibits that lower oxygen level in culture media improves embryonic quality.