In vitro short-term effects of SMS 201 -995, bromocriptine and TRH on growth hormone cell morphology from human pituitary adenomas

This study reports, by immunocytochemistry. ultrastructure and morphometry, the in vitro effects of SMS 201-995 (10 nhl), bromocriptine ( 1 pM) and TRH (10 pM) on the morphology of cells from two acromegalic patient atlenomas containing immunoreactive growth hormone (GH). By electron microscopy. one tumor presented numerous large secretory granules (densely granulated growth hormone cell adenoma) while they were scarce and small in the other (sparsely granulated growth hormone cell adenoma); fibrous bodies could be seen in the specimen and in vitro. ln the sparsely granulated growth hormone cell adenoma. TRH produced an increase in endoplasmic reticulum surface density compared to the other cultures. Bromocriptine increased the number and decreased the secretory granule diameters, while SMS 201-995 produced no significant changes in the same time. In the densely granulated growth hormone cell adenoma, the three substances increased the number of granules. TRH increased the mitochondrial volume density and endoplasmic reticulum surface density (with respect to the other cultures). SMS 201-995 decreased the mitochondrial and lysosome volume densities and endoplasmic reticulum surface density. We conclude that 1) TRH produces in cultured cells of both adenoma types an increase in cellular activity. 2) In cultured sparsely granulated growth hormone adenoma cells, bromocriptine has a stronger inhibitory effect than SMS 201-995. In cultured densely granulated growth hormone cells adenoma, bromocriptine has smaller inhibitory effect than SMS 201-99.

Molecular epidemiology and antimicrobial resistance of Clostridium difficile in a national geriatric hospital in Costa Rica

Background: the epidemiology of Clostridium difficile infections (CDI) is changing rapidly worldwide; knowledge on the genotypes of C. difficile circulating in specialized geriatric hospitals and their resistance to antibiotics is scarce or non-existent. Methods: prospective study of the molecular epidemiology of CDI, conducted in a national geriatric hospital in Costa Rica for a period of 11 months. Results: the study patients exhibited a diverse range of comorbidities, but none were associated with CDI. Polyclonality, including three new ribotypes, and a high level of resistance to antibiotics were determined by analysing the 32 isolates obtained in these cases. Despite the diversity in strains observed, the most frequent types were NAP6/RT002 and NAP2/RT001. NAP9/RT017 was associated with community acquisition. Nineteen types of antimicrobials were used before the onset of diarrhoea in the patients; no particular genotype was associated with the onset of infection or severity. Conclusion: based on the abundance of strain types observed and their resistance to antibiotics in this geriatric hospital, these results contribute to a better overall understanding of the epidemiology of CDI worldwide, and to surveillance programmes targeting geriatric populations.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Centro de Investigación en Enfermedades Tropicales (CIET)UCR::Vicerrectoría de Docencia::Salud::Facultad de Microbiologí