Plasmid and serological differences between Edwardsiella ictaluri strains.

Several studies have shown that isolates of Edwardsiella ictaluri obtained from infected channel catfish in the southeastern United States harbor two cryptic plasmids, designated pCL1 (5.7 kb) and pCL2 (4.9 kb). These isolates appear to be serologically homogeneous. To extend these studies, we focused our analyses on two isolates of nonictalurid origin. Plasmid analyses of a danio isolate showed that it harbored plasmids which were similar if not identical to pCL1 and pCL2. This strain was also serologically indistinguishable from those isolated from channel catfish. In contrast, a green knife fish (GNF) isolate harbored four plasmids with relative mobilities of 6.0, 5.7, 4.1, and 3.1 kb. Southern blot analyses indicated that only the 5.7- and 4.1-kb plasmids strongly hybridized under high-stringency conditions to probes specific for pCL1 and pCL2, respectively. The GNF isolate showed minimal reactivity when reacted with polyclonal antiserum prepared against a channel catfish isolate. However, polyclonal antiserum to the GNF isolate strongly reacted with the GNF isolate in both surface fluorescence and agglutination reactions. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analyses of cell lysates showed that the protein banding patterns of the strains compared were similar. However, Western blots of proteinase K-digested cell extracts showed that O antigen of the GNF isolate was antigenically distinct from the O antigen of the other isolates. These studies indicate that there are different serotypes of E. ictaluri and suggest that plasmid and serological analyses of future isolates of E. ictaluri can be used to determine whether structurally distinct strains are emerging in major channel catfish aquaculture areas.

Long-term brightness variations of neptune and the solar cycle modulation of its albedo.

The visual brightness and albedo of Neptune vary periodically during the 11-year solar cycle with an amplitude of 4%, anticorrelated with the variation of solar ultraviolet output. A seasonal trend in color suggests that Neptune, like Uranus, may have a slightly reddened pole.

Pneumothorax reconsidered.

The condition of pneumothorax is re-examined, and a working classification is presented. The present concepts about the mechanisms of production of a pneumothorax are examined and a new approach to the condition is presented. A new system of pneumothorax drainage is described.

Report on a child with stricture following foreign body of long duration in the bronchus. Discussion on the management of bronchial foreign bodies.

A case report and the management of a 10-year-old girl who had inhaled a foreign body into the right intermediate bronchus at some unknown (but certainly not recent) time previously is given. A stricture at the site of the impaction of the foreign body was found. The excision of the stricture and repair of the bronchus with pericardium is described together with a 3-year follow-up report. The diagnosis and immediate management of foreign bodies in the bronchus are discussed and the importance of differentiating organic and non-organic foreign bodies is stressed. The management of bronchial strictures is discussed as is the result obtained in the above reported case.

The intravenous urodynamogram.

Modifications to the intravenous urogram are described. It is suggested that the time has come to rationalise the standard procedure. If an evaluation of the lower urinary tract is required, the voiding films may be modified to provide an intranvenous urodynamogram. If an evaluation of the upper urinary tract is directed at a specific question, then the number of spot-films can often be reduced.

The arts of percussion and auscultation of the chest re-examined.

Clinical teaching of percussion and auscultation is examined critically, and it is suggested that there is confusion on the subject both in textbooks and in the minds of clinicians and students. Percussion should be viewed more in terms of 'feel' than 'sound', and thus a classification of 'hard', 'intermediate' and 'soft' dullness is introduced. As regards auscultation, a plea is made for differentiation between obstructed and non-obstructed consolidation of lobes, a point recognized by some clinicians, but not enunciated with clarity by teachers. The differences between the clinical findings in obstructive consolidation of the upper and lower lobes are discussed. The importance of distinguishing between tracheal and bronchial breathing is emphasized.

Lung biopsy with local anesthesia: report on 100 cases with the use of a recently introduced technique.

A new technique for taking lung, pleural, and pericardial samples, under local anesthesia if required, is described. In the series presented in this article there have been no deaths, and complications which have been discussed are minimal. The experience gained in the use of this technique confirms that it is safe and provides a very high percentage of success in obtaining the required samples.