Analysis of the immunologic heterogeneity of HIV-1: I. "Arginine-glutamine trigger" in the fourth position of the central tetrapeptide of the V3 loop of gp120

This article reviews the existing knowledge base concerning the biology of spinal fusion, with the understanding that the focus is weighted toward posterolateral lumbar spinal fusion because of a relative paucity of biologic information on healing of other types of fusions. The discussion focuses first on the basic science of spinal fusion healing from the standpoint of animal modeling. Next, the discussion centers on the multitude of local factors that can affect fusion healing. Finally, the numerous systemic factors known to affect fusion healing are discussed.     

Genetic analysis of the South Altaian population of the Mendur-Sokkon village, Altai Republic

This study was a continuation of complex research on the gene pool of indigenous Siberian populations conducted at the Institute of Cytology and Genetics, Siberian Division, Russian Academy of Sciences. In the population of South Altaians from the Mendur-Sokkon village, Ust'-Kanskii raion, Altai Republic, polymorphism for the following genetic markers was studied: blood groups ABO, MNSs, Rhesus, Kell, Duffy, and P; erythrocyte acid phosphatase (AcP); phosphoglucomutase 1 (PGM1); haptoglobin (Hp); and transferrin (Tf). The genetic position of South Altaians relative to the populations of the European part of Russia, Siberia, and the Urals was estimated. It was demonstrated that the gene pool of the South Altaian population of Mendur-Sokkon possessed both Caucasoid and Mongoloid genetic characteristics, with the latter prevailing. Genetically, this population is most closely related to Mongols and Nentsis. The genetic distance between South and North Altaians was large; this agreed with earlier genetic data and confirmed anthropological and ethnographic evidence indicating that these two groups had different backgrounds and were at different stages of ethnogenesis.     

Separation of germanium and magnesium isotopes in a small electromagnetic separator

A method is described for the electromagnetic separation of germanium and magnesium isotopes in a small electromagnetic separator with a focusing angle of 180 °. The construction of an ion source and an ion collecter (isotope receiver) is considered. The ion source, which maintains a discharge in the vapor of the element to be separated, operates satisfactorily in a temperature range up to 1500 °C. The construction of the receiver permits the simultaneous collection of all the isotopes of the element to be separated. The relation of the size of the ion current, focused on the receiver, to the method of discharge in the source was investigated. During the separation of germanium isotopes the ionic current at the receiver reached 15–20 ma; during magnesium separation it was 35–40 ma. Every hour ～ 40 mg of enriched germarilum isotopes (or ～ 25 mg of enriched magnesium isotopes) was collected in the receiver's containers. The coefficient of material recovery was 2–6%. Mass-spectrometric analyses were carried out on metal samples for the enriched germanium isotopes and the compound Mgl₂ for the magnesfurn isotopes. The enrichment coefficient for germanium and magnesium lay within the limits 17–175 depending on natural diffusion and mass of the isotopes.     

A method for generating morphometric data using SEM and an automated television image analysis system for the investigation of cell borders

The traditional silver nitrate impregnation method used for visualization of cell borders does not allow the study of intercellular relationships and fails to demonstrate features of cell microrelief. It is shown that osmium tetroxide impregnation of vascular tissue, emphasizing cell border lines, and a special image analysis program for the semiautomatic system IBAS 2 can be used together for the effective analysis of the fine structure and of the cell layer. Our investigations of the aortic endothelium using this complex method have confirmed the heterogeneity of aortic endothelial cells in health and demonstrated that the endothelium of different aortic regions displays differential responses to blood pressure elevation and, further, that a major factor underlying the alterations observed in endothelial cells in disease and hypertension is the differential degree of overlap of the neighboring endothelial cells.