Fluorescence microscopy applied to intracellular transport by microtubule motors

Long-distance transport of many organelles inside eukaryotic cells is driven by the dynein and kinesin motors on microtubule filaments. More than 30 years since the discovery of these motors, unanswered questions include motor–organelle selectivity, structural determinants of processivity, collective behaviour of motors and track selection within the complex cytoskeletal architecture, to name a few. Fluorescence microscopy has been invaluable in addressing some of these questions. Here we present a review of some efforts to understand these sub-microscopic machines using fluorescence.     

X-ray spectroscopy and imaging of selenium in living systems

Background

Selenium is an essential element with a rich and varied chemistry in living organisms. It plays a variety of important roles ranging from being essential in enzymes that are critical for redox homeostasis to acting as a deterrent for herbivory in hyperaccumulating plants. Despite its importance there are many open questions, especially related to its chemistry in situ within living organisms.

Association of Endogenous Testosterone with Lipid and Blood Glucose Profiles in Elderly Men with Angiographically Proven Cardiovascular Disease of Nadia and Murshidabad District,West Bengal

Testosterone is commonly known for its role in the regulation of reproductive physiology in men. Epidemiologic studies suggest that endogenous testosterone levels may be implicated in cardiovascular diseases (CVDs). Our study aimed to investigate the relationship between serum total testosterone (TT) levels and lipid profile as well as fasting blood glucose (FBG) levels in male patients ranging from 40 to 70 years old with angiographically proven CVDs from Nadia and Murshidabad district of West Bengal, India. These data were compared with the normal men with no CVD history. We observed a significantly low serum TT levels in CVD patient group compared to the normal group. Among CVD patients, a significant (p < 0.05) negative association was found between serum TT and total cholesterol, triglyceride, low density lipoprotein and very low density lipoprotein, whereas a significant positive correlation (p < 0.05) was found between serum TT and high density lipoprotein. We also observed a highly significant negative correlation between TT and FBG levels in CVD patient group. Thus, in these two densely populated district of West Bengal with poor socio-economic condition, low levels of serum TT in elderly men is associated with CVD that appear together with an atherogenic lipid milieu that may be involved in the pathogenesis of CVD. Results further indicate that low serum TT might have a role in the development of hyperglycemia as evidenced from high FBG level in elderly men.     

Evaluation of adaptability to different seasons in goat breeds of semi-arid region in India through differential expression pattern of heat shock protein genes

The present study was conducted to examine differential expression pattern of HSP genes and adaptability in Indian goat breeds of semi-arid region. The study was conducted in five animals from each breed viz. Barbari, Sirohi, and Jhakrana during winter, thermo-neutral and summer seasons. The respiratory rate (RR) and rectal temperature (RT) of the goats were recorded at 09:00 h during the study period. The blood samples were collected for RNA isolation, cDNA synthesis, and quantitative analysis of HSP genes expression by quantitative RT-PCR. The RR increased significantly (p < 0.01) during summer as compared to winter and thermo-neutral season however, RT did not change (p > 0.05) during different seasons. The expression of HSP genes was significantly (p < 0.01) increased during summer (high THI) as compared to thermo-neutral season in all the goat breeds. Among HSPs, only HSP90 was upregulated (p < 0.01) in Jhakrana goats during winter as compared to thermo-neutral season. The deviation in expression of HSP genes during summer and winter with respect to thermo-neutral season was minimum in Barbari goats. Therefore, it can be concluded that Barbari goats possessed better adaptability during summer and winter as compared to Sirohi and Jhakrana goats in semi-arid climatic conditions of India.     

Pentacyclic triterpenoids and sterols from seven species of mangrove

The isolation of pentacyclic triterpenoids from seven species of fresh mangrove leaves using a simple and rapid method is described. The leaves were homogenized using chloroform—methanol and the extract was diluted with water to precipitate out triterpenoids which were separated into neutral and acidic fractions. These were analysed by gas-liquid chromatography as acetyl and trimethylsilyl ether derivatives on a 3% OV-17 column. Sterols were isolated from the chloroform layer by preparative thin layer chromatography and were analysed by gas-liquid chromatography as their trimethylsilyl ether derivatives on a 3% OV-17 column. The triterpenoids found were α-amyrin, β-amyrin, lupeol, oleanolic acid and ursolic acid in most of the samples. Sterols found in all the samples were cholesterol, campesterol, stigmasterol, sitosterol and stigmast-7-en-3β-ol. Retention indices of the triterpenoids and sterols have been determined.     

Occurrence of N-cyano alkaloids in asian Strychnos species

The isolation of N-cyano-sec.-pseudostrychnine and N-cyano-sec.-pseudobrucine from the leaves of Strychnos wallichiana Steud. ex. DC. is reported. N-Cyano-sec.-pseudostrychnine and a N-cyano-sec.-pseudo-colubrine have been found among the alkaloids obtained from the stem bark of S. ignatii Berg.     

Alkaloids and iridoids from Strychnos nux-vomica fruits

The alkaloid mixtures present in the fruit pericarp and fruit pulp of Strychnos nux-vomica L. are qualitatively very similar to that found in the seeds. In addition to alkaloids previously known to occur in this plant, small amounts of 4-hydroxystrychnine and the new base N-methyl- sec.-pseudo-β-colubrine have been isolated. Cantleyine, which is a non-indolic base and an artefact, has also been obtained. The iridoid mixture in the fruit pulp is predominantly loganin with small amounts of related compounds, including the biogenetically important secologanin.     

Effect of superparasitism on the development,sex ratio and progeny ofBracon greeni Ashmead

Résumé Bracon greeni Ashmead est un ectoparasite larvaire de la noctuelleEublemma amabilis Moore, prédatrice sur laquiers en Inde. L'effet de superparasitisme sur le développement, le sex ratio et la descendance du parasite ont été étudiés en détail. Le pourcentage de développement du parasite décro?t quand le nombre de parasites développés par h?te augmente. La période de développement, de l'œuf à l'éclosion de l'adulte, est de 10, 85 jours et ce délai est un peu plus court quand l'h?te est fortement superparasité. La taille de la femelle adulte décro?t avec l'augmentation du nombre de parasites développés par h?te. Il y a prédominance du sexe femelle chez le parasite. Le superparasitisme ne para?t avoir que peu d'action sur le taux sexuel. Quand plus de trois parasites se partagent un seul h?te, la longévité de l'adulte et la fécondité du parasite sont réduits. De tels individus sont mauvais voiliers et inactifs dans leur comportement.