Molecular detection of a bacterial contaminant Bacillus pumilus in symptomless potato plant tissue cultures.

An aberrant random amplified polymorphic DNA (RAPD) marker in genomic DNA of tissue culture plantlets was frequently observed during a comparison of DNA fingerprints derived from potato germplasm grown in tissue culture and the field. The RAPD marker was cloned, sequenced and determined to be of bacterial origin. A bacterial contaminant was isolated from the tissue culture plants and identified as a Bacillus pumilus. A set of sequence characterised amplified region (SCAR) primers were designed from the sequence of the cloned fragment and tested for the specific detection of B. pumilus. Polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLPs) were also used to generate B. pumilus profiles specific to our isolate in order to test and confirm the sequence homology of amplified markers generated from a range of DNA samples isolated from tissue culture plants and pure isolates of B. pumilus-like bacteria.

The Junior Red Cross goes to Healthland.

An amusing reminder of earnest attempts to teach the principles of public health, Junior Red Cross Time brought plays and games about "Healthland" to schoolchildren in the 1920s. Explaining why health education became part of the mission of the Junior Red Cross raises larger issues, such as the ideology and practice of the American Red Cross in war and peace, the place of health in the moral education of children, and the transition from the activism of the Progressive Era to the markedly different social climate of the 1920s. The Junior Red Cross promoted Healthland largely because it was an innocuous concept that had been stripped of potentially controversial features to adapt it to the conservative mood of postwar America. This process of dilution mirrored the fate of the adult Red Cross, which briefly and unsuccessfully sought to reinvent itself as a national (and international) agency for the promotion of public health. The unreality of Healthland is no mere coincidence; its separation from the real world was a crucial part of its appeal to the Red Cross in the 1920s.

The use of quantitative cultures and antibody coating of bacteria to diagnose bacterial pneumonia by fiberoptic bronchoscopy.

This study uses quantitative cultures and immunofluorescent demonstration of antibody-coated bacteria to differentiate colonizing from infecting bacteria in lower respiratory secretions obtained by fiberoptic bronchoscopy. The fiberoptic bronchoscope was passed transnasally without the use of a nasotracheal tube, and a single-sheath cytology brush dipped in lower respiratory secretions served as inoculum for quantitative cultures. Secretions were also collected by aspiration through the bronchoscope side channel for fluorescent examination. None of 60 control patients had greater than 4,000 colony-forming units (CFU) per brush of a single bacterium on quantitative culture. In contrast, more than 4,000 CFU per brush were isolated from 29 of 33 episodes of clinically defined lower respiratory infection (p less than 0.001). Only 1 of 60 control patients had antibody-coated bacteria in their lower respiratory secretions, but antibody coating was demonstrated in association with 24 of 33 episodes of infection (p less than 0.001).

Use of pulmonary function tests in the management of sarcoidosis.

The literature on pulmonary function testing in sarcoidosis is critically reviewed. The results indicate that pulmonary function tests are not a reliable means for detecting the presence of parenchymal sarcoidosis, nor do they provide an accurate estimate of the extent of parenchymal disease. There are at present no known pulmonary function criteria that allow the clinician to predict the natural cause of pulmonary sarcoidosis or the response to therapy. The major value of pulmonary function testing is to assess changes in the disease course of the individual patient through sequential measurements. Currently there is no conclusive evidence that measurements of arterial blood gas tensions or pulmonary compliance add significantly to the sensitivity and specificity of the vital capacity and diffusing capacity in the management of sarcoidosis.