RESUMEN
The mechanisms of hypocalcemia, recurrent infections and hypogammaglobulinemia associated with metabolic decompensation of propionic acidemia due to propionyl-CoA carboxylase deficiency have not been defined. A 7-week-old infant with this disorder presented with severe hypocalcemia and B cell lymphopenia during an episode of metabolic acidosis and hyperammonemia. Hypocalcemia (1.1 mmol l-1) was associated with elevated serum intact parathyroid hormone (122 ng l-1), hyperphosphatemia, hypophosphaturia and hypercalcuria, indicating parathyroid hormone resistance. B cell lymphopenia (20 cells microliters-1) was associated with transient neutropenia, anemia and subsequent hypogamma-globulinemia (IgG < 294 mg dl-1, IgM < 8 mg dl-1, IgA < 8 mg dl-1), while T cells were normal. Parathyroid hormone resistance and B cell lymphopenia resolved following treatment with hemodialysis, diet and carnitine. These complications may be due to interference with parathyroid hormone renal tubular action and B cell maturation/proliferation by accumulated organic acids.
Asunto(s)
Errores Innatos del Metabolismo de los Aminoácidos/complicaciones , Linfocitos B , Linfopenia/etiología , Hormona Paratiroidea/fisiología , Propionatos/sangre , Errores Innatos del Metabolismo de los Aminoácidos/terapia , Femenino , Humanos , Hipocalcemia/etiología , Inmunoglobulinas/deficiencia , LactanteAsunto(s)
Derechos Civiles/legislación & jurisprudencia , Enfermedades Profesionales/inducido químicamente , Personal de Hospital/legislación & jurisprudencia , Exposición a Riesgos Ambientales , Humanos , Concentración Máxima Admisible , Enfermedades Profesionales/prevención & control , Estados UnidosAsunto(s)
Infección Hospitalaria/epidemiología , Infección Hospitalaria/microbiología , Infección Hospitalaria/mortalidad , Farmacorresistencia Microbiana , Infecciones por Enterobacteriaceae/epidemiología , Capacidad de Camas en Hospitales , Departamentos de Hospitales , Hospitales de Enseñanza , Humanos , Infecciones por Pseudomonas/epidemiología , Sepsis/etiología , Infecciones Estafilocócicas/epidemiología , Estados UnidosAsunto(s)
Infección Hospitalaria/epidemiología , Bacterias/efectos de los fármacos , Infección Hospitalaria/mortalidad , Infecciones por Escherichia coli/epidemiología , Gentamicinas/farmacología , Hospitales con más de 500 Camas , Hospitales de Enseñanza , Humanos , Meticilina/farmacología , Resistencia a las Penicilinas , Estaciones del Año , Sepsis/etiología , Infecciones Estafilocócicas/epidemiología , Infecciones Estreptocócicas/epidemiología , Estados UnidosRESUMEN
Optimal temperatures for the growth of bacteria and yeasts isolated from several cold-mountain habitats were determined. The lowest optimal temperatures encountered were in the 10-15 degrees C range, even though most of the isolates were obtained from sites at or near 0 degrees C.
Asunto(s)
Bacterias/crecimiento & desarrollo , Temperatura , Microbiología del Agua , Levaduras/crecimiento & desarrollo , Altitud , FríoRESUMEN
Turnover times for water passing through several Sulfolobus acidocaldarius-containing springs were determined by measuring the dilution rates of small amounts of sodium chloride that were added to the springs. Chloride was diluted out exponentially, while concentrations of the bacteria remained constant. Additionally, temperature, pH, and chemical composition of the springs also remained constant during the time that the chloride was being diluted. The springs are thus steady-state systems, and since the rates of bacterial growth must be at least equal to the chloride dilution rates, minimal doubling times for the bacterial populations can be calculated. Half-times for chloride dilution, equivalent to bacterial doubling times, were on the order of 10 to 20 h for springs ranging in volume from about 20 to 2,000 liters, but approximately 30 days for two larger springs of about 1 million liters. Formaldehyde-fixed cells of a serologically distinguishable strain of S. acidocaldarius were also added as markers to four of the smaller springs, and the dilution rates of these bacteria were compared with the chloride dilution rates. The rates agreed reasonably well, thus verifying the growth rates obtained from the chloride dilution rates. In three springs, exponential growth was studied by draining the springs and allowing them to refill with bacteria-free water. Exponential doubling times were on the order of a few hours, much more rapid than steady-state doubling times. The methods used in this work may have wider utility in aquatic environments.
Asunto(s)
Bacterias/crecimiento & desarrollo , Microbiología del Agua , Antígenos Bacterianos , Bacterias/inmunología , Técnicas Bacteriológicas , Recuento de Células , Técnica del Anticuerpo Fluorescente , Agua Dulce , Calor , Concentración de Iones de Hidrógeno , Cloruro de Sodio/análisis , Sulfuros/análisis , Azufre/análisis , Agua/análisis , WisconsinRESUMEN
Natural populations of Sulfolobus, a new genus of bacteria occurring in sulfur-rich, acid hot springs and soils, were found to oxidize large amounts of sulfur to sulfuric acid at temperatures up to 85 degrees C. These bacteria are important high-temperature geochemical agents in solfatara soils.
RESUMEN
Either DDT or polychlorinated biphenyls were added to mixed cultures containing a marine diatom and a marine green alga that were sensitive and resistant, respectively, to these organochlorine compounds. The diatom grew faster and was therefore dominant in control cultures, but its dominance diminished in treated cultures, even at concentrations of chlorinated hydrocarbons that had no apparent effect in pure cultures. Such stable pollutants could disrupt the species composition of phytoplankton communities, thereby affecting whole eco-systems.
Asunto(s)
Compuestos de Bifenilo/farmacología , Chlorophyta/efectos de los fármacos , DDT/farmacología , Plancton/efectos de los fármacos , Ecología , Fitoplancton/efectos de los fármacos , Fitoplancton/crecimiento & desarrollo , Plancton/crecimiento & desarrollo , Bifenilos Policlorados/farmacologíaRESUMEN
The growth rates of two species of marine diatoms were reduced by polychlorinated biphenyls (PCB's), widespread pollutants of the marine environment, at concentrations as low as 10 to 25 parts per billion. In contrast, a marine green alga and two species of freshwater algae were not inhibited at these or higher concentrations. The sensitivity of these species to PCB's paralleled their sensitivity to DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane].