Antidiphtheria immunity in children after immunization with adsorbed DPT vaccine and ADPT-M toxoid

Antidiphtheria immunity in children aged 3-15 years was evaluated, depending on their age, the vaccinal preparation chosen for immunization and the immunization schedule. Adsorbed DPT vaccine was shown to have a higher immunological activity in comparison with adsorbed DT toxoid with reduced antigen content. The relationship between the tension of antidiphtheria antitoxic immunity in children and the possibility of the formation of the clinical forms of diphtheria with different severity in the patients was established. Children aged 4-6 years were considered to be a group of high risk in diphtheria morbidity, as it was among the children of this group that toxic and subtoxic forms of diphtheria were most often registered (44.9 +/- 7.1% of the examinees); in addition, a high proportion of children seronegative to this infection (26,3 +/- 2.2%) was observed in this group.     

Evenly tritium-labeled peptides and their in vivo and in vitro biodegradation

Biologically active peptides evenly labeled with tritium were used for studying the in vitro and in vivo biodegradation of the peptides. Tritium-labeled peptides with a specific radioactivity of 50-150 Ci/mmol were obtained by high temperature solid phase catalytic isotope exchange (HSCIE) with spillover tritium. The distribution of the isotope label among all amino acid residues of these peptides allows the simultaneous determination of practically all possible products of their enzymatic hydrolysis. The developed analytical method includes extraction of tritium-labeled peptides from organism tissues and chromatographic isolation of individual labeled peptides from the mixture of degradation products. The concentrations of a peptide under study and the products of its biodegradation were calculated from the results of liquid scintillation counting. This approach was used for studying the pathways of biodegradation of the heptapeptide TKPRPGP (Selank) and the tripeptide PGP in blood plasma. The pharmacokinetics of Selank, an anxiolytic peptide, was also studied in brain tissues using the intranasal in vivo administration of this peptide. The concentrations of labeled peptides were determined, and the pentapeptide TKPRP, tripeptide TKP, and dipeptides RP and GP were shown to be the major products of Selank biodegradation. The study of the biodegradation of the heptapeptide MEHFPGP (Semax) in the presence of nerve cells showed that the major products of its biodegradation are the pentapeptide HFPGP and tripeptide PGP. The enkephalinase activity of blood plasma was studied with the use of evenly tritium-labeled [Leu]enkephalin. A high inhibitory effect of Semax on blood plasma enkephalinases was shown to arise from its action on aminopeptidases. The method, based on the use of evenly tritium-labeled peptides, allows the determination of peptide concentrations and the activity of enzymes involved in their degradation on a tg scale of biological samples both in vitro and in vivo.     

Evenly tritium labeled peptides in study of peptide in vivo and in vitro biodegradation

Biologically active peptides evenly labeled with tritium were used for studying the in vitro and in vivo biodegradation of the peptides. Tritium-labeled peptides with a specific radioactivity of 50–150 Ci/mmol were obtained by high temperature solid phase catalytic isotope exchange (HSCIE) with spillover tritium. The distribution of the isotope label among all amino acid residues of these peptides allows the simultaneous determination of practically all possible products of their enzymatic hydrolysis. The developed analytical method includes extraction of tritium-labeled peptides from organism tissues and chromatographic isolation of individual labeled peptides from the mixture of degradation products. The concentrations of a peptide under study and the products of its biodegradation were calculated from the results of liquid scintillation counting. This approach was used for studying the pathways of biodegradation of the heptapeptide TKPRPGP (Selank) and the tripeptide PGP in blood plasma. The pharmacokinetics of Selank, an anxiolytic peptide, was also studied in brain tissues using the intranasal in vivo administration of this peptide. The concentrations of labeled peptides were determined, and the pentapeptide TKPRP, tripeptide TKP, and dipeptides RP and GP were shown to be the major products of Selank biodegradation. The study of the biodegradation of the heptapeptide MEHFPGP (Semax) in the presence of nerve cells showed that the major products of its biodegradation are the pentapeptide HFPGP and tripeptide PGP. The enkephalinase activity of blood plasma was studied with the use of evenly tritium labeled [Leu]enkephalin. A high inhibitory effect of Semax on blood plasma enkephalinases was shown to arise from its action on aminopeptidases. The method, based on the use of evenly tritium-labeled peptides, allows the determination of peptide concentrations and the activity of enzymes involved in their degradation on a μg scale of biological samples both in vitro and in vivo.     

Increased Expression of Several Mitochondrial Genes in Human and Monkey B-Cell Non-Hodgkin Lymphomas

Mitochondrial genes overexpressed in human and monkey B-cell non-Hodgkin lymphomas (B-NHLs) were sought via subtraction hybridization, cloning, and differential screening of the resulting cDNA libraries. The cDNAs of mitochondrial genes constituted an appreciable proportion of all lymphoma-specific cDNAs. Lymphomogenesis was associated with upregulation of a set of mitochondrial genes, which varied with lymphoma type but always included NADHIV. A possible association between upregulation of certain mitochondrial genes and cell malignant transformation is discussed.     

Degradation of the ACTH(4-10) analog Semax in the presence of rat basal forebrain cell cultures and plasma membranes

Summary. Here a new approach of the elucidation of paths of proteolytic biodegradation of physiologically active peptides, based on the use of a peptide with isotopic label at all amino acid residues and the enrichment of HPLC samples with unlabeled peptide fragments in UV-detectable concentration, has been proposed. The method has been applied for the investigation of degradation dynamics of the neuroactive heptapeptide MEHFPGP (Semax) in the presence of plasma membranes, and cultures of glial and neuronal cells obtained from the rat basal forebrain. The splitting away of ME and GP, and formation of pentapeptides are the predominant processes in the presence of all tested objects, whereas the difference in patterns of resulting peptide products for glial and neuronal cells has been detected. In conclusion, the approach applied allows analyzing physiologically active peptide concentrations in biological tissues and degradation pathways of peptides in the presence of targets of their action.     

Influence of regulatory genes of type 1 human immunodeficiency virus on proliferation and differentiation of murine embryonic stem cells

Spontaneous formation of embryoid bodies and subsequent differentiation of some cells into cardiomyocytes were demonstrated on murine embryonic stem cells of R1 line. The lines of embryonic stem cells were obtained that had been transfected with genetic constructs carrying expressing regulatory genes of the human immunodeficiency virus tat and nef and "green protein" gene (GFP). The transfection of embryonic stem cells with the gene tat stimulated their proliferative activity, while this activity decreased in the cells transfected with the gene nef. The time necessary for the formation of embryoid bodies by all lines of transfected cells was similar to that in the control cells. In the cultures of cells transfected with nef and tat, the number of embryoid bodies and the percentage of embryoid bodies with contracting cardiomyocytes were higher and lower than in the control, respectively. Thus, an inverse correlation was observed between the effects of regulatory genes of the human immunodeficiency virus on proliferation and differentiation embryonic stem cells.