Effect of some antitubercular drugs on the calmodulin content ofMycobacterium tuberculosis

The effect of the antitubercular drugs isoniazid (10 μg/ml), ethambutol (10 μg/ml), rifampicin (0.5 μg/ml) and streptomycin (1 μg/ml) on the calmodulin like protein (CAMLP) content ofMycobacterium tuberculosis H₃₇R_v andM. tuberculosis H₃₇R_a was investigated. The drugs were added to actively growing cells at their mid log phase of growth (14 days) and after 12 more hours of incubation, CAMLP was estimated. In both the mycobacteria, all the four antitubercular drugs CAMLP.     

Lectin-functionalized microchannels for characterizing pluripotent cells and early differentiation

Embryonic stem (ES) cells are capable of proliferating and differentiating to form cells of the three embryonic germ layers, namely, endoderm, mesoderm, and ectoderm. The utilization of human ES cell derivatives requires the ability to direct differentiation to specific lineages in defined, efficient, and scalable systems. Better markers are needed to identify early differentiation. Lectins have been reported as an attractive alternative to the common stem cell markers. They have been used to identify, characterize, and isolate various cell subpopulations on the basis of the presentation of specific carbohydrate groups on the cell surface. This article demonstrates how simple adhesion assays in lectin-coated microfluidic channels can provide key information on the interaction of lectins with ES and definitive endoderm cells and thereby track early differentiation. The microfluidic approach incorporates both binding strength and cell surface receptor density, whereas traditional flow cytometry only incorporates the latter. Both approaches are examined and shown to be complementary with the microfluidic approach providing more biologically relevant information.     

<Emphasis Type="Italic">n</Emphasis>-Dimensional cube and simplex: A glimpse into the concept of multi-dimensional spaces

A close study of a square and a cube helps in extrapolating the concepts of vertex, edge and face to higher dimensions. Recurrence relationships have been heuristically arrived at, with the help of which high school students could be taught to calculate iteratively the number of vertices, edges, faces, etc of cube-like objects and simplexes of higher dimensions.     

Seasonal variations in markers of stress and oxidative stress in rats

High ambient temperature has been reported to increase oxidative stress by increasing lipid peroxidation and decreasing antioxidant defence in transition dairy cows. It is also known to cause an increase in plasma cortisol levels in goats, European hedgehog and human volunteers. High levels of glucocorticoids have been reported to decrease blood glutathione and erythrocyte superoxide dismutase activity in rats. Although institutional animal houses in research laboratories of developed countries maintain animals in air-conditioned rooms at constant temperature, the same is not true of animal houses in the developing countries especially those belonging to smaller institutions and this could affect the results of the experiments being conducted on these animals. The present research study was done to assess the effects of seasonal variations on the status of erythrocyte oxidative damage, antioxidant defence and plasma cortisol levels in adult female Wistar rats. Rats were kept in their home cages and were left in non-air-conditioned procedure rooms in two different seasons, Hot season (March-May) and Cool season (June to September). Erythrocyte Thiobarbituric acid reactive substances and plasma cortisol levels were significantly increased in rats exposed to high ambient temperature and humidity of the hot season as compared to the rats of the cool season. Erythrocyte reduced glutathione levels, erythrocyte glutathione peroxidase and superoxide dismutase activities were significantly decreased in the hot season group of rats. The results of our experiments showed that exposure of adult female Wistar rats to high ambient temperature and humidity of the hot season increases neuroendocrine stress, oxidative stress and decreases antioxidant defence in them.     

Doubly-terminated two-variable lossless ladder networks

In this paper necessary and sufficient conditions are derived for a two-variable positive real function to be the driving-point impedance of certain classes of doubly-terminated lossless ladder networks. Specifically, two classes of networks are studied: (a) the class of networks in which the lossless structure is a cascade of p₁- and p₂-variable two-ports, each two-port having its transmission zeros at the origin and/or at infinity; (b) the class of networks in which the lossless structure is a lowpass or highpass ladder network with series arms having p₁- and p₂-type elements in series and shunt arms having the p₁- and p₂-type elements in parallel. It is indicated that via suitable transformations of the variables, conditions for many other types of ladder structures can be derived.     

Cerebrospinal fluid free sialic acid and aspartate transaminase levels in meningitis

Background  Sialic acid (SA) is a nine carbon sugar derived from mannosamine and pyruvate. High levels of sialic acid and aspartate transaminase (AST) levels in cerebrospinal fluid have been described in pyogenic meningitis (PM) compared to tubercular meningitis (TBM). Objectives  To evaluate the levels of CSF free SA in PM and TBM and to assess the correlation between CSF free SA and CSF glucose or total protein levels. Patients and Methods  A total of 122 subjects were studied and divided into children and adults. Further, these have been subdivided into controls, PM and TBM. CSF free SA was estimated by thiobarbituric acid assay of Warren and AST by Reitmann and Frankel method. Results  CSF free SA and AST levels in children and adults were significantly high in PM (p<0.001) as compared to TBM and controls. Conclusion  A very high CSF free SA and AST were found to be characteristic of PM, making them useful parameters to differentiate PM from TBM.     

Self-assessed intelligence: Inter-ethnic,rural–urban,and sex differences in Malaysia

The present study examined inter-ethnic, rural–urban, and sex differences in self-assessed intelligence (SAI) in a Malaysian general population sample. In total, 633 individuals varying in rural or urban location, ethnicity (Malay, Kadazan, and Bajau), and sex (women versus men) provided their self-assessed overall intelligence and ten multiple intelligences. In general, results of a series of univariate analyses of variance showed that urban participants tended to have higher SAI than their rural counterparts and that men reported higher SAI than women. There was also a significant main effect of ethnicity, with Malays generally having lower estimates than Bajaus and Kadazans, respectively. There were few significant interactions between ethnicity, urban–rural location, and sex. These data present the first concurrent investigation of ethnic, rural–urban, and sex differences in SAI, and are discussed in relation to previous theoretical discussions of SAI.