Disostosis con afectación de miembros. Hallazgosultrasonográficos en el síndromede roberts / Dysostosis with limb involvement. Ultrasonographic findings in roberts' syndrome

El síndrome de Roberts, también conocido como síndrome pseudotalidomídico(1), síndrome SC (iniciales de dos hermanos afectos) o síndrome SCfocomelia, es una rara disostosis(2) de herencia autosómica recesiva con una gran variedad de manifestaciones clínicas. De todas ellas las más características son la presencia de retraso en el crecimiento pre y postnatal, las anomalías craneofaciales y las reducciones simétricas de los miembros de diversa gravedad(3).En el estudio genético, aparecen alteraciones que afectan a la heterocromatina de las regiones pericéntricas y NOR de la mayoría de los cromosomas. Estas regiones presentan un aspecto hinchado, probablemente como resultado de la repulsión de las cromátides en estas zonas, lo que se traduce en separación prematura de los centrómeros durante la profase y la metafase(4).Esta separación prematura de los centrómeros se conoce con el nombre de efecto Roberts(4,5) (AU)

Diagnosis of pneumococcal pneumonia by polymerase chain reaction (PCR) in whole blood: a prospective clinical study.

BACKGROUND: Streptococcus pneumoniae is the leading cause of community acquired pneumonia; however, only a small proportion of cases can be detected by conventional methods. The ability of the polymerase chain reaction (PCR) test performed on whole blood samples to identify patients with pneumococcal pneumonia was investigated. METHODS: One hundred and fourteen consecutive adult patients with community acquired pneumonia were evaluated by a wide battery of diagnostic tests in order to determine the aetiology. Blood samples from these patients and 50 controls were also tested by the nested PCR test to detect selected pneumolysin gene fragments of S pneumoniae. RESULTS: The patients were divided into four groups: (1) 40 patients with pneumococcal pneumonia in 22 of whom (55%) the PCR was positive (eight of 11 with bacteraemia and 14 of 29 without); (2) 30 with pneumonia due to other pathogens in all of whom the PCR was negative; (3) 44 with pneumonia of unknown aetiology in 14 of whom (32%) PCR was positive, and (4) 50 controls in whom the PCR test was positive in two (4%). Thus, the sensitivity of the test was 55% and the specificity 100% (81% if positive PCR tests among undiagnosed patients are considered as false positive results). CONCLUSION: PCR applied to whole blood samples appears to be a sensitive and very specific diagnostic test for identifying patients with pneumococcal pneumonia with a potential application in clinical practice.

Purification and characterization of limonoate dehydrogenase from Rhodococcus fascians.

Limonoate dehydrogenase from Rhodococcus fascians has been purified to electrophoretic homogeneity by a procedure that consists of ion-exchange, hydrophobic, and affinity chromatography. The native enzyme has a molecular mass of around 128,000 Da and appears to be composed of four similar subunits (30,000 Da each). The isoelectric point is 4.9 as determined by isoelectric focusing. The homogeneous enzyme was used to determine the NH2-terminal amino acid sequence. The enzyme was purified from cells grown in either fructose or limonoate as a carbon source. Limonoate dehydrogenase activity was higher in limonoate-grown cultures. Additionally, the enzyme preparations differed in their affinity for limonoids but not for NAD+. In all cases limonoate dehydrogenase exhibited a higher catalytic rate and stronger affinity for limonoate A-ring lactone than for disodium limonoate, the limonoid traditionally used for in vitro activity assays. Our data confirm previous reports proposing that limonoate A-ring lactone is the physiological substrate for limonoate dehydrogenase. The increase in limonoate dehydrogenase activity observed in limonoate-grown cultures appears to be caused by a rise in protein levels, since chloramphenicol prevented such an effect.