Maintenance of rat taste buds in primary culture

The differentiated taste bud is a complex end organ consisting of multiple cell types with various morphological, immunocytochemical and electrophysiological characteristics. Individual taste cells have a limited lifespan and are regularly replaced by a proliferative basal cell population. The specific factors contributing to the maintenance of a differentiated taste bud are largely unknown. Supporting isolated taste buds in culture would allow controlled investigation of factors relevant to taste bud survival. Here we describe the culture and maintenance of isolated rat taste buds at room temperature and at 37 degrees C. Differentiated taste buds can be sustained for up to 14 days at room temperature and for 3-4 days at 37 degrees C. Over these periods individual cells within the cultured buds maintain an elongated morphology. Further, the taste cells remain electrically excitable and retain various proteins indicative of a differentiated phenotype. Despite the apparent health of differentiated taste cells, cell division occurs for only a short period following plating, suggesting that proliferating cells in the taste bud are quickly affected by isolation and culture.

Waterborne typhoid fever in Dade County, Florida. Clinical and therapeutic evaluation of 105 bacteremic patients

An extensive outbreak of waterborne typhoid fever occurred in 1973 at a migrant labor camp in Dade County, Florida. Blood cultures from 105 of the 188 patients with proved or presumptive cases of typhoid fever grew Salmonella typhi. The clinical and laboratory findings in these patients were reviewed. Fever, usually with temperatures above 38.8 degrees C and of the sustained type, was a primary manifestation of disease, although a majority of the patients also complained of headache and gastroenteric symptoms. Hepatic or splenic enlargement was present in 52 per cent and 42 per cent, respectively, whereas rose spots were detected in only 13 per cent. The total leukocyte count was normal in 74 per cent, but serum levels of liver and muscle enzymes were frequently elevated. Gastrointestinal, pulmonary and neurologic complications were infrequent; circulatory failure was not observed. Defervescence in response to antibiotic therapy was variable; however, the median response among 68 patients who received chloramphenicol was two days less than that in 34 patients treated with ampicillin. There was one possible treatment failure with ampicillin. The relapse rate of 10 per cent in chloramphenicol-treated patients was not significantly greater than the 3 per cent rate among those treated with ampicillin. Serologic studies for typhoid fever were of limited diagnostic value since the titer of agglutinins was 1:160 or higher in 49 per cent of the serums obtained before treatment, and a fourfold rise in titer occurred in only 24 per cent of 57 patients studied. The serologic response to chloramphenicol treatment did not differ from that to ampicillin.