Protective effect of maternal prenatal melatonin administration on rat pups born to mothers submitted to constant light during gestation

We studied the effects of adverse conditions such as constant light (LL) on the circadian rhythm of malate (MDH, EC 1.1.1.37) and lactate (LDH, EC 1.1.1.27) dehydrogenase activities of the testes of male Wistar rats on postnatal day 28 (PN28), anxiety-like behavior (elevated plus-maze test) at PN60 and sexual behavior at PN120. The rats were assigned to mother groups on day 10 of pregnancy: control (12-h light/dark), LL (light from day 10 to 21 of pregnancy), and LL+Mel (LL and sc injection to the mothers of a daily dose of melatonin, 1 mg/kg body weight at circadian time 12, from day 17 to 21 of pregnancy). LL offspring did not show circadian rhythms of MDH (N = 62) and LDH (N = 63) activities (cosinor and ANOVA-LSD Fisher). They presented a 44.7 percent decrease in open-arm entries and a 67.9 percent decrease in time (plus-maze test, N = 15, P < 0.001, Mann-Whitney U-test and Kruskal-Wallis test), an increase in mounting (94.4 percent), intromission (94.5 percent) and ejaculation (56.6 percent) latencies (N = 12, P < 0.01, Mann-Whitney U-test and Kruskal-Wallis test) and lower numbers of these events (61, 59 and 73 percent, respectively; P < 0.01, N = 12) compared to controls. The offspring of the LL+Mel group presented MDH and LDH circadian rhythms (P < 0.05, N = 50, cosinor and ANOVA-LSD Fisher), anxiety-like and sexual behaviors similar to control. These findings supported the importance of the melatonin signal and provide evidence for the protective effects of hormones on maternal programming during gestation. This protective action of melatonin is probably related to its entrainment capacity, favoring internal coupling of the fetal multioscillatory system.

New Helicoverpa armigera Hbn cell line from larval hemocyte for baculovirus studies.

A new cell line from the larval hemocytes of H. armigera was established in Grace's medium modified by adding lactalbumin hydrolysate and yeastolate (3.3g/l), and supplemented with fetal bovine serum (20%). The cell line was designated as NIV-HA-1195. The cell population at P-78 consisted mainly of epithelial-like cells (89.36%), fibroblast-like cells (8.31%) and giant cells (2.13%). The population doubling time was 96hr at P-8, 60hr at P-43. The chromosome number ranged from 45 to 200. The cell line is susceptible to the baculoviruses, Autographa californica nucleopolyhedrovirus (AcNPV), Spodoptera litura NPV and the homologous HaNPV. Isoenzyme profile and results of 16S rRNA heteroduplex analysis clearly indicated the species specificity of the new cell line.

Karyological, biochemical, and physiological aspects of Callophysus macropterus (Siluriformes, Pimelodidae) from the Solimöes and Negro Rivers (Central Amazon)

Karyological characteristics, i.e., diploid number, chromosome morphology and nucleolus organizer regions (NORs), biochemical characteristics, i.e., electrophoretic analysis of blood hemoglobin and the tissue enzymes lactate dehydrogenase (LDH), malate dehydrogenase (MDH), alcohol dehydrogenase (ADH), and phosphoglucose isomerase (PGI), and physiological characteristics, i.e., relative concentration of hemoglobin and intraerythrocytic concentrations of organic phosphates were analyzed for the species Callophysus macropterus collected from Marchantaria Island (white water system - Solimöes River) and Anavilhanas Archipelago (black water system - Negro River). Karyological and biochemical data did not reveal significant differences between specimens collected at the two sites. However, the relative distribution of hemoglobin bands I and III (I = 16.33 ñ 1.05 and III = 37.20 ñ 1.32 for Marchantaria specimens and I = 6.33 ñ 1.32 and III = 48.05 ñ 1.55 for Anavilhanas specimens) and levels of intraerythrocytic GTP (1.32 ñ 0.16 and 2.76 ñ 0.18 for Marchantaria and Anavilhanas specimens, respectively), but not ATP or total phosphate, were significantly different, indicating a physiological adaptation to the environmental conditions of these habitats. It is suggested that C. macropterus specimens from the two collecting sites belong to a single population, and that they adjusted some physiological characteristics to adapt to local environmental conditions.

Isoenzyme analyses of Malaysian Schistosoma, S. mekongi and S. japonicum by isoelectric focusing in polyacrylamide gel.

Isoenzyme patterns of adult Malaysian Schistosoma, S. mekongi and S. japonicum strains were analysed by isoelectric focusing (IEF) in polyacrylamide gel. Enzyme patterns obtained from Malaysian Schistosoma homogenates differed from those of S. mekongi and S. japonicum strains. Malaysian Schistosoma was found to differ from S. japonicum by 8 enzymes, namely phosphoglucomutase, phosphoglucoisomerase, malate dehydrogenase, acid phosphatase, hydroxy-butyrate dehydrogenase, hexokinase and alkaline phosphatase, and from S. mekongi by phosphoglucomutase, malate dehydrogenase, aldolase and alkaline phosphatase. These results and the distinct biology of the parasite suggest that Malaysian Schistosoma is a new species in the S. japonicum complex.

Metabolic studies on mycobacteria-I. Demonstration of key enzymes of glycolysis and tricarboxylic acid cycle on polyacrylamide gels.

Polyacrylamide gel electrophoresis (PAGE) technique was standardised to demonstrate some key enzymes of glycolysis, hexose mono phosphate (HMP) pathway and tricarboxylic acid cycle in slow growing mycobacteria (M. avium. M. gastri) as well as in fast growing mycobacteria (M. vaccae, M. phlei). The enzymes studied were lactate dehydrogenase (LDH) glucose-6-phosphate dehydrogenase (G6PD), aconitase, isocitrate dehydrogenase (ICD), succinic dehydrogenase (SDH), fumerase and malate dehydrogenase (MDH). All the three pathways were found to be operative in slow as well as fast growing mycobacteria. Using this technique M. leprae specific MDH activity was demonstrated in the cell free extract of M. leprae. It's (MDH) electrophoretic mobility on gels lies in the range shown by other mycobacterial species studied and was distinct from that of host MDH. It appears that PAGE offers a useful tool for metabolic characterization of M. leprae using infected tissues.