Azadirachta indica acts as a pro‐oxidant and modulates cell cycle associated proteins during DMBA/TPA induced skin carcinogenesis in mice

The present study was designed to determine the modulatory effect of aqueous Azadirachta indica leaf extract (AAILE) on cell cycle–associated proteins during two‐stage skin carcinogenesis in mice. Considering the dual role of reactive oxygen species in cancer and its chemoprevention, the levels of lipid peroxidation (index of peroxidative damage) were also determined. Skin tumours were induced by topical application of 7,12‐dimethylbenz(a)anthracene (DMBA) as a carcinogen followed by the repetitive application of 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) as a promoter. Skin tumours obtained in the DMBA/TPA group exhibited enhanced expression of proliferating cell nuclear antigen (PCNA, index of proliferation), p21 and cyclin D1, with no alterations in p53 expression in comparison to the control group. Tumours in AAILE + DMBA/TPA group exhibited low PCNA and cyclin D1 expression and enhanced expression of p53 and p21 in comparison to the DMBA/TPA group. The skin tumours obtained in the AAILE + DMBA/TPA group exhibited high lipid peroxidation levels in comparison to the tumours obtained in the DMBA/TPA group. The observations of the present study suggest that AAILE behaves as a pro‐oxidant in the tumours, thereby rendering them susceptible to damage, which eventually culminates into its anti‐neoplastic action. Also, cell cycle regulatory proteins may be modulated by AAILE and could affect the progression of cells through the cell cycle. Copyright © 2012 John Wiley & Sons, Ltd.     

Inheritance study of the little finger length

An attempt has been made to see whether the length of the little finger (based upon its approach to the last interphalangeal joint of the ring finger) follows any hereditary pattern in its transmission. For this 100 biological families along with their offsprings have been analysed. Results show that heredity certainly plays a role for this trait.Forms the part of Ph. D. Thesis.     

A theoretical study of the structures of (Gly-Pro-Leu)n and (Gly-Leu-Pro)n

Theoretical conformation studies have been carried out for the polytripeptides (Gly-Pro-Leu)n and (Gly-Leu-Pro)n and the Fourier transforms of the structures have been calculated. X-ray powder patterns of these polymers had indicated that both these polymers take up coiled-coil triple-helical structures, but in the case of (Gly-Pro-Leu)n it was not clear whether the triple helix is formed by three parallel polypeptide chains or by a single chain folding back on itself (Scatturin et al 1975). Our studies show that both the polytripeptides can take up stereochemically satisfactory triple-helical structures with three parallel chains. There is also very good agreement between the calculated intensity distribution and that of the observed X-ray pattern, in each case.     

The Gene-Duplication Problem: Near-Linear Time Algorithms for NNI-Based Local Searches

The gene-duplication problem is to infer a species supertree from a collection of gene trees that are confounded by complex histories of gene-duplication events. This problem is NP-complete and thus requires efficient and effective heuristics. Existing heuristics perform a stepwise search of the tree space, where each step is guided by an exact solution to an instance of a local search problem. A classical local search problem is the {tt NNI} search problem, which is based on the nearest neighbor interchange operation. In this work, we 1) provide a novel near-linear time algorithm for the {tt NNI} search problem, 2) introduce extensions that significantly enlarge the search space of the {tt NNI} search problem, and 3) present algorithms for these extended versions that are asymptotically just as efficient as our algorithm for the {tt NNI} search problem. The exceptional speedup achieved in the extended {tt NNI} search problems makes the gene-duplication problem more tractable for large-scale phylogenetic analyses. We verify the performance of our algorithms in a comparison study using sets of large randomly generated gene trees.     

Phosphoinositides of sheep platelets plasma membranes.

Phospholipid composition of sheep blood platelets and its various plasma membrane fractions have been analyzed. Based on their flotation rates in discontinuous sucrose density gradient centrifugation, three membrane fractions were isolated. 5'-Nucelotidase and alkaline phosphatase were distributed nearly equally in all the three membrane fractions. However these membrane fractions showed differences in the distribution of phosphatidyl ethanolamine, phosphatidyl choline and phosphoinositides. Phosphatidyl ethanolamine was predominant in fraction I (11.05 micrograms PLP/mg protein) while phosphatidyl choline was predominant in fractions II and III (110.10 and 68.30 micrograms PLP/mg protein respectively). Phosphatidyl inositol (Ptd-InsP) was equally distributed in all three membrane fractions. However, both Ptd-InsP and phosphatidyl inositol 4,5-bisphosphate were about 4-fold higher in fraction II (73.55 and 89.89 micrograms PLP/mg protein respectively).     

Synthesis and properties of (6,7-dimethoxy-4-coumaryl)alanine: a fluorescent peptide label.

The synthesis of racemic and l-(6,7-dimethoxy-4-coumaryl)alanine (Dmca) is described and some spectral and physicochemical properties are reported. The utility of Dmca as a highly sensitive and specific label for the quantitative detection of synthetic peptides in HPLC and in minimal essential media (MEM) is also described.     

DELAYED URIC ACID ACCUMULATION IN PLASMA PROVIDES ADDITIONAL ANTI-OXIDANT PROTECTION AGAINST IRON-TRIGGERED OXIDATIVE STRESS AFTER A WINGATE TEST

Reactive oxygen species are produced during anaerobic exercise mostly by Fe ions released into plasma and endothelial/muscle xanthine oxidase activation that generates uric acid (UA) as the endpoint metabolite. Paradoxically, UA is considered a major antioxidant by virtue of being able to chelate pro-oxidative iron ions. This work aimed to evaluate the relationship between UA and plasma markers of oxidative stress following the exhaustive Wingate test. Plasma samples of 17 male undergraduate students were collected before, 5 and 60 min after maximal anaerobic effort for the measurement of total iron, haem iron, UA, ferric-reducing antioxidant activity in plasma (FRAP), and malondialdehyde (MDA, biomarker of lipoperoxidation). Iron and FRAP showed similar kinetics in plasma, demonstrating an adequate pro-/antioxidant balance immediately after exercise and during the recovery period (5–60 min). Slight variations of haem iron concentrations did not support a relevant contribution of rhabdomyolysis or haemolysis for iron overload following exercise. UA concentration did not vary immediately after exercise but rather increased 29% during the recovery period. Unaltered MDA levels were concomitantly measured. We propose that delayed UA accumulation in plasma is an auxiliary antioxidant response to post-exercise (iron-mediated) oxidative stress, and the high correlation between total UA and FRAP in plasma (R-Square = 0.636; p = 0.00582) supports this hypothesis.