Modeling, histological study and pathogenetic aspects of experimental traumatic osteomyelitis

The tibial diaphysis osteotomy with limited separation of periosteum on the ends of the fragments with subsequent local infection by Staphylococcus aureus culture was conducted. In 90% of observations chronic inflammation was revealed in affected bones while morphological investigation conduction. An acute traumatic disorders of intraosseous blood circulation (the bone infarction) and local staphylococcal infection play the main role in the traumatic osteomyelitis pathogenesis.     

Mutagenic and antimutagenic activities of human whole blood, plasma and albumin

The seeds of Crepis capillaris were used to examine the mutagenic und antimutagenic properties of human whole blood, plasma, serum albumin and gamma-globulin by recording chromosomal and chromatid aberrations. The antimutagenic activity was determined by preliminary, simultaneous, and subsequent biosubstrate treatments of the seeds. The whole and twice-diluted blood, as well as plasma, induced aberrations exceeding the level of self-arbitrary mutagenesis by 3.7-5.3 and 2.6-3.1 times, respectively. When the blood was diluted to its 20% concentration, the antimutagenic efficiency of biological fluids was recorded. Human serum albumin and gamma-globulin were found to have an antimutagenic effect. In the dilutions having no antimutagenic effect, blood, plasma, and albumin showed their ability to be effectively decrease the level of induced aberrations.     

Pathology of AIDS in children

AIDS in children is a multisystem disease. The various infections, degenerative, proliferative and vascular lesions can be classified into three categories based on the known, presumed or undetermined pathogenesis. The primary lesions are due to HIV infection. The associated lesions are related to direct or indirect sequelae of HIV infection or its treatment. The third category is of lesions of undetermined pathogenesis. The pediatric pathologist plays an important role in the study and management of AIDS by demonstrating new pathologic lesions, by making the etiologic diagnosis of infection in children with AIDS, and by providing clinicopathologic correlation which leads to better understanding of the disease process and its natural history. Diagnosis of neoplastic disorders is also made by the pathologist. There is a dearth of systematic pathologic study of AIDS in children in developing countries. Although no basic differences between pathologic lesions in pediatric AIDS in Western countries, and in developing countries is expected, such a study would lead to better understanding and better management of the disorder as it affects children from the developing countries.     

Sites of alcohol and volatile anaesthetic action on GABA(A) and glycine receptors

Volatile anaesthetics have historically been considered to act in a nonspecific manner on the central nervous system. More recent studies, however, have revealed that the receptors for inhibitory neurotransmitters such as gamma-aminobutyric acid (GABA) and glycine are sensitive to clinically relevant concentrations of inhaled anaesthetics. The function of GABA(A) and glycine receptors is enhanced by a number of anaesthetics and alcohols, whereas activity of the related GABA rho1 receptor is reduced. We have used this difference in pharmacology to investigate the molecular basis for modulation of these receptors by anaesthetics and alcohols. By using chimaeric receptor constructs, we have identified a region of 45 amino-acid residues that is both necessary and sufficient for the enhancement of receptor function. Within this region, two specific amino-acid residues in transmembrane domains 2 and 3 are critical for allosteric modulation of both GABA(A) and glycine receptors by alcohols and two volatile anaesthetics. These observations support the idea that anaesthetics exert a specific effect on these ion-channel proteins, and allow for the future testing of specific hypotheses of the action of anaesthetics.     

Correlation between synthesis conditions, coherently diffracting domain size and cubic phase stabilization in barium titanate

The Constant Rate Thermal Analysis method has been used under different experimental conditions to obtain barium titanate powder of very small grain size. Both a crystallographic and a dielectric study ham been carried out on samples sintered at different temperatures. It is deduced that the formation of small coherently diffracting domains is improved by the generation of oxygen vacancies and the cubic phase stabilization depends on the coherently diffracting domain size rather than on the particle size.     

Medium and substitution pattern effects on the action of hydroxyflavones as photoprotectors against singlet molecular oxygen-mediated photooxidation of fats

The ability of mono-, di-, tri-and tetra-hydroxyflavones (7-and 3-hy-droxyflavones, 7, 8-dihydroxyflavone, baicalein and fisetin) to act as photoprotectors against singlet molecular oxygen [O²(Δ_g)]-initiated photooxidation of fats has been established by a kinetic study. The overall quenching rate constants for a series of five hydroxyflavones perfectly parallel their respective behaviour as inhibitors of the sensitized photooxidation of linoleic acid. The best antioxidative effect was exerted by 7-hydroxyflavone which does not chemically react with O²(¹Δ_g). Nevertheless for the remaining flavonoids of the series, the physical deactivation of O²(¹Δ_g) largely prevails over the chemical process. As for the cases of phenols and related hydroxy-aromatic derivatives, the ionization of the -OH group in the flavones, dramatically accelerates the rate of photooxidation. Under these conditions, the 7-hydroxyflavone also reacts effectively with O²(¹Δ_g). Given that flavonoids are natural oil components, this medium effect should be taken into account during the oil-refining process, in order to avoid the flavonoid photodestruction.