Effect of Serotonin on Development of the Luteinizing Hormone-Releasing Hormone System in Wistar Rat Embryos

The work studied effect of serotonin on development of the system of luteinizing hormone-realizing hormone (LHRH) in rats at the prenatal period. LHRH-neurons located along its migration pathway were revealed immunocytochemically at the 18th day of embryonal development (E18 and so on) after serotonin synthesis inhibition by daily intraperitoneal injections of n-chlorophenylalanine from E11 to E17 (experimental group). In control animal group, the saline was injected. The percent content of LHRH-neurons located in the forebrain rostral part was higher in the experimental group as compared to control. The opposite quantitative ratio of neurons was observed in the more caudal (hypothalamic) area. This indicates deceleration of the LHRH-neuronal migration under conditions of serotonin deficit. Study of the LHRH-neuron differentiation showed that in the experimental group the neuron optical density correlating with the LHRH content in the cell decreased as compared to the control group both in males and in females. The size of LHRH-neurons on n-chlorophenylalanine administration decreased, but only in females. Thus, serotonin affects both migration and differentiation of LHRH-neurons.     

Structural changes induced by diethyl ether in cultured neuroblastoma cells

It has been found that the more differentiated growing cells of a neuroblastoma culture retract their neurites under the action of diethyl ether (for anesthesia) in a dose of 1.0 ml per 15 ml of culture medium for 2 h; as a result, their cytoplasm is gradually drawn into the cell bodies. Under these conditions the coefficient K, which reflects the ratio of the number of neuroblastoma cell bodies to the number of their processes and is 9.94±2.12 in the initial state, gradually increases to 19.66±1.93 (P<0.002). There is also a substantial change in the shape of the cells and a decrease in their volume. This reaction is characteristic both of relatively undifferentiated neuroblastoma cells and for more differentiated cells in various phases of individual cellular development and morphological differentiation. The data obtained create the prerequisites for a search for drugs capable of preventing the destruction of neurons under anesthesia.A. A. Bogomolets Institute of Physiology, Ukrainian Academy of Sciences, Kiev. Kiev Institute for the Advanced Training of Physicians, Ukrainian Ministry of Health. Translated from Neirofiziologiya, Vol. 24, No. 3, pp. 279–285, May–June, 1992.     

The immunological response in volunteer donors immunized with a Pseudomonas vaccine]

The trial of experimental vaccine consisting of protective protein antigens of P. aeruginosa cell wall was carried out on 114 volunteers. The vaccine proved to be faintly reactogenic and induced the formation of specific humoral immunity in 98% of the volunteers who retained a high level of anti-P. aeruginosa antibodies in their blood for up to 5 months (the term of observation after the course of immunization was over.     

The rapid differential diagnosis of bacterial and viral meningitis by using the lysozyme test]

The authors have modified the technique of the lysozyme test by adding polimixin M sulfate into the gel bacterial medium. Rapid diagnosis with the use of this test is based on different time of the appearance of the lysis areas: in bacterial meningitides the CSF lysozyme activity is detectable within 15-120 min, whereas in viral meningitides it manifests 40-50 min later or does not manifest at all. The results were found to depend on the time of the CSF collection: the earlier the CSF samples were obtained, the higher was the share of positive results.     

Effect of moderately low temperatures (-30 C to -70 C) on the permeability of erythrocyte membranes

The barrier properties of reconstituted and native erythrocyte membranes frozen to -30, -40 or -70 degrees C and stored for a month were studied. The release of markers, namely haemoglobin molecules, [14C] sucrose and K+ ions from cells and membrane structures was measured. The main changes in the barrier function of ghosts and cells have been found to be due to freeze-thawing rather than to storage conditions. Glycerol, a cryoprotectant, appeared to stabilize the barrier properties of erythrocyte membranes for haemoglobin molecules, [14C] sucrose and to a lesser extent for K+ ions. The cryoprotective effect of glycerol has been shown to be considerably greater towards erythrocytes ghosts than to native erythrocytes.