Neuroglobina: nuevo miembro de la familia de las globinas / Neuroglobin: a novel member of the globin family

Durante mucho tiempo se asumió que la hemoglobina y la mioglobina eran las únicas globinas de los vertebrados. En el año 2000 se descubrió un tercer tipo de globina, que sobre la base de su ubicación preferencial en el sistema nervioso fue denominada neuroglobina. Aunque aún se desconoce su función específica, se han planteado varias hipótesis entre las que se destaca la que sugiere que puede destoxificar las especies reactivas del oxígeno y el nitrógeno. Otros estudios proponen que es parte de una cadena de transducción de señales que transmite el estado redox de la célula o que inhibe la apoptosis. Aunque algunas funciones son más probables que otras, aún no se ha establecido definitivamente cuál es la función fisiológica de la neuroglobina en los vertebrados. No obstante, no hay dudas de que esta globina tiene una función esencial, conservada y que es beneficiosa para las neuronas

For a long time, it was taken for granted that hemoglobin and mioglobin were the only vertebrate globins. In 2000, a third type of globins was discovered on the basis of its preferential location in the nervous system and it was called neuroglobin. Although its specific function is still unknown, a number of hypotheses has been put forward, mainly the one suggesting that it may detoxify the reactive oxygen species and the nitrogen. On the other hand, other studies state that neuroglobin is part of a signal transduction chain that transmits the redox state of the cell or inhibits apoptosis. Though some functions are more probable than others, the real physiological function of neuroglobin in vertebrae has not been finally established. Nevertheless, this globin has undoubtedly an essential preserved function that is useful for neurons

Histopathological changes in experimental cholera with a non toxigenic non- O1 non-O139 Vibrio cholerae strain isolated from Kolkata, India.

This study was conducted to understand the pathophysiological changes in experimental rabbit ileal loop model using the Vibrio cholerae strain non-O1non-O139, isolated as sole pathogen from clinically diagnosed cholera patients in Kolkata. Significant amount of haemorrhagic fluid accumulation was observed in all the test loops of rabbit model where the strain of V.cholerae was inoculated as compared to control loops. Microscopic examination of the accumulated fluid showed the presence of erythrocytes and pus cells. Histology revealed structural alteration of the villous epithelium with inflammatory cells infiltration in all the layers of the gut mucosa including the nerve plexus region. Preliminary observation with a haemagglutinin protease extracted from the non-O1 non-O139 strain, was also studied in different concentrations in the same animal model which showed similar type of macroscopic and microscopic response in the ileal loops as seen with the original strain. The results highlight that along with other pathways, inflammatory cells and the enteric neurons have an important role in the pathophysiology of diarrhoea and the isolated protease may be the probable virulence factor in initiating the disease process in this non-O1non-O139 strain induced cholera.

Are viable Mycobacterium leprae present in lepromatous patients after completion of 12 months' and 24 months' multi-drug therapy?

A study was carried out to determine whether or not viable bacilli persist in MB patients treated with 12-month and 24-month multidrug therapy (MDT). In the first group, 60 untreated lepromatous patients who had an initial average bacterial index (BI) of 3+ or more were enrolled. At the completion of 12 months of MDT, skin biopsies were obtained and M. leprae concentrate was inoculated into the footpads of five thymectomized and irradiated (T900r) mice. Rees technique was used for the mouse footpad (MFP) experiment. Harvesting was done it the 6th, 9th and 12th months. Out of the 60 biopsies inoculated into mouse footpads to check the viability of bacilli, 2 skin biopsies (3.3%) showed significant growth and 10 (16%) showed equivocal growth. 27 patients also had nerve biopsies tested for growth in MFP studies. None of the inoculated nerve biopsies showed significant multiplication in the MFP experiments. However, 4 biopsies (14%) showed equivocal growth. In the second group, 20 patients had skin biopsies and 10 had nerve biopsies done at the end of 24 doses of MDT in order to test the viability of bacilli; none of the skin or nerve biopsies from these patients showed any growth. This study showed that M. leprae present in the tissues after 24 doses of MDT are not viable and the drug schedule of 24 doses is adequate to treat leprosy patients, irrespective of their BI. However, a small (3.3%) percentage of the patients with a high BI harbour viable bacteria in the skin after 12 doses of treatment. Since a large majority of the patients (38 patients) who had a high initial BI responded well to the treatment, it is important to find out the reason for the lack of response in two patients. One of the reasons may be the presence of drug-resistant strains. It is important to follow up on these patients for a longer duration to ascertain whether or not they would relapse.

Synaptophysin and neurofilament expression in neurons infected with dengue virus

The expression of two genes encoding the neuronal specific proteins synaptophysin and high molecular weigh neurofilaments was investigated in primary cell cultures of embryonic mouse brain infected with dengue virus type 2, using immunocytochemistry and Western blot analysis with monoclonal antibodies. The viral infection leads to a 20-fold induction in the expression of the mentioned synaptogenesis-related proteins. These results suggest a correlation between virus infection and neuropathology of immature neurons in vivo