Changes in the activity of gamma-amino butyric acid transaminase and succinic semialdehyde dehydrogenase in the cobalt and iron experimental epileptogenic foci in the rat brain

GABA-transaminase (GABA-T) and succinic semialdehyde dehydrogenase (SSA-DH) activities were measured in the mitochondrial fractions from the cobalt- and FeCl3-induced chronic epileptogenic foci in the rat brain. Electroencephalographically, the FeCl3 epileptogenic focus remained active for a duration longer than that of the cobalt focus. In both the foci SSA-DH activity showed significant increases which were concomitant with the EEG epileptiform activity. In cobalt focus, the GABA-T activity fell whereas, in the FeCl3 focus it was unchanged. In cobalt focus fall in GABA-T activity seemed to be concomitant with EEG epileptiform discharge. The measurements of the enzyme activities in the mirror (secondary) foci showed that, except for a brief stimulation of SSA-DH activity in the mirror focus in FeCl3 epileptic animals, the enzyme activities remained unchanged. Possible significance of the observed enzymatic changes in the physiology of epileptogenic focus is discussed.     

Variation in the expression of aphidicolin-induced fragile sites in human lymphocyte cultures

Summary A correlation between specific fragile sites and cancer breakpoints has been suggested raising the question of fragile site expression as a predisposing factor in the occurrence of cancer in some persons. Before addressing the question of increased fragility among patients at high risk for cancer, we analyzed the variability of aphidicolin-induced fragile sites among nine normal persons and also among repeated samples from three of these individuals. Considerable variation in both the frequency and location of these fragile sites was observed and the data strongly suggest the significant variation of 6 of the 16 selected sites to be primarily due to sampling differences. These findings indicate that the use of fragile sites as a screening tool for patients at high risk of cancer should be carefully monitored relative to the variation inherent in both culture and individual expression.     

Seasonal distribution of Aeromonas hydrophila in river water and isolation from river fish

The seasonal distribution of Aeromonas hydrophila in water and recovery rate from live river fish was investigated. The highest isolation rates of A. hydrophila occurred in water during the late winter followed by a progressive decline in density during the summer and monsoon seasons. The organism was recovered from fish throughout the period from which it was concluded that they form a reservoir which is unrelated to their density in water. The enterotoxigenicity of some environmental strains was tested in suckling mice and rabbit ileal loop.     

The mylohyoid bridge in four population samples from India, with observations on its suitability as a genetic marker

Four adult skeletal samples from the states of Uttar Pradesh, Andhra Pradesh, and Bihar in India have been studied for the incidence of mylohyoid bridge. The incidence, varying between 2.98% and 7.14%, has been compared with frequencies reported for other populations of the world. The range of variation for Indians, as a whole, falls within the lower levels of the spectrum of worldwide variation for this trait, ranging between 0.47% for French Europeans and 33.8% observed among Plains American Indians. While noting its possible significance for clinical purposes, the suitability of the mylohyoid bridge as a population genetic marker has been discussed. It is emphasized that its use as a genetic marker in isolation of other discrete traits has serious limitations. For meaningful population definition and relationships as many discrete variants as possible ought to be utilized.     

Effect of corticosteroids on carbohydrate metabolism in Bufo melanostictus (Schneider)

A single injection of corticosterone (1 or 5 micrograms/50 g body weight) produced a significant elevation in plasma glucose, liver and muscle glycogen contents of B. melanostictus. Single but identical doses of aldosterone had no effect on plasma glucose concentration. Liver and muscle glycogen contents were however significantly augmented. Administration of 1 or 5 micrograms corticosterone and 1 microgram or 200 ng aldosterone/50 g body weight, for 15 days, caused no change in plasma glucose concentration. In all the groups receiving corticosterone or aldosterone for 15 days, liver and muscle glycogen contents significantly increased. The magnitude of increase in liver and muscle glycogen by aldosterone was marginally greater than that by corticosterone. The results suggest that both the corticosteroids may be gluconeogenic in B. melanostictus.     

Presence and activity of anammox and denitrification process in low ammonium-fed bioreactors

A combination of anammox and denitrification process was studied for 300 days in low ammonium-fed bioreactors under the support of organic carbon. Nutrient profiles, (15)N-labelling techniques and qualitative fluorescence in situ hybridization (FISH) probes were used to confirm the nitrogen removal pathways and intercompetition among different bacteria populations. About 80% of nitrogen removal was achieved throughout the study period. The results confirmed that anammox bacteria were absent in the bioreactor inoculated with anaerobic granules only but they were present and active in the central anoxic parts of biopellets in the bioreactor inoculated with mixed microbial consortium from activated sludge and anaerobic granules. It also showed that the anammox bacteria were successfully enriched in the low ammonium-fed bioreactors. Results of this study clearly demonstrated that anammox and denitrification processes could coexist in same environment and anammox bacteria were less competitive than denitrifying bacteria.     

Comparison of membrane proteins of Mycobacterium tuberculosis H37Rv and H37Ra strains

Background  

The potential causes for variation in virulence between distinct M. tuberculosis strains are still not fully known. However, differences in protein expression are probably an important factor. In this study we used a label-free quantitative proteomic approach to estimate differences in protein abundance between two closely related M. tuberculosis strains; the virulent H37Rv strain and its attenuated counterpart H37Ra.     

Subtractive differential display: a modified differential display technique for isolating differentially expressed genes

Differential display (DD) is a novel PCR-based technique, very commonly used to study differentially expressed genes at the mRNA level. In this paper we report a modified version of this technique that we have used to study the differences between the mRNA population from brain tissue of adult and old rats. We have modified the technique to enhance reproducibility and reduce false positives and redundancy. It is fast and does not require any expensive or uncommon reagent. We choose to call it as subtractive differential display as it is a differential display performed over subtracted mRNA population. We have used this protocol successfully to clone a number of age-related differentially expressed sequences from rat brain that need to be sequenced to establish the gene identity.