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Biomedical subjects

J S Chapman

Publications and source records attributed to J S Chapman.

At least 55 records · Page 3Linked to original sources
PubMed1978

Radiographic manifestations of pulmonary Mycobacterium kansasii infections.

The radiographic characteristics of 187 pristine cases of pulmonary Mycobacterium kansasii infection are reviewed. The cases were selected from a total of 309 patients with two positive sputum cultures. All but three of the 187 patients had pulmonary disease. The progenitive focus of disease almost always involved the upper lobes, the right side (72%) more often than the left (50%). Upper lobe disease began posterior to the trachea in every case. Only one patient had disease that originated in an atypical location, that is, in the superior segment of the right lower lobe. The most frequent radiographic abnormality was cavitation (96% of diseased patients). The classical description of a thin walled cavity (or cavities) occurred in 33% of patients. A cicatricial reaction was common (two-thirds of cases). About 63% of patients had endobronchial spread. The likelihood of endobronchial disease decreased as the distance from the progenitive focus increased. Pleural effusions and adenopathy were rare. In an individual case, it is not possible to differentiate between pulmonary M. tuberculosis and M. kansasii infections.

Adolescent↗
PubMed1977

Persistence of Mycobacterium tuberculosis in sputum without chest roentgenographic evidence of active disease.

Mycobacterium tuberculosis has been isolated consistently from sputum over an 11-year period in an asymptomatic 64-year-old man whose chest radiographs show evidence of healed primary tuberculosis (Ranke complex) but no evidence of parenchymal disease. A lymph node-bronchial fistula associated with the Ranke complex is the likely site of active tuberculosis; however, repeated examinations of the upper and lower respiratory tract have been normal. We attribute the persistence of infection in our patient to erratic usage of antituberculous drugs.

Humans↗
PubMed1976

International Kveim histology trial.

An histological analysis of Kveim-test biopsies performed on a total of 306 patients including those with sarcoidosis, Crohn's disease, tuberculosis, and collagen disease is presented. Five main Kveim suspensions, "antigens," were used in the survey, Colindale K 12, Lot 5, Marburg 2 and 3, Commonwealth Serum Laboratory (CSL) early batches, 001/2/3 and late batches, 005/6. The biopsies were read blind by two observers (overall agreement 75%), the nature of the antigen and disease later disclosed, and the finding statistically analysed. It was agreed that focal epithelioid-cell collections remain as the essential criteria for the diagnosis of Kveim positivity. Diffuse epithelioid cells, Langhans' giant cells, lymphocytes, and necrosis are associated with focal epithelioid cells and hence Kveim positivity. Steroids were found to inhibit Kveim positivity. Observer disagreements were mainly due to difficulties in distinguishing macrophages from true epithelioid cells. We conclude that doubtful cells should be ignored in deciding Kveim positivity. Lymph-node-derived Kveim antigens were the most sarcoid-specific. They were more granulogenic and produced more necrosis, despite also producing the most foreign material. It is recommended that validation of new Kveim antigens must include adequate testing on patients with Crohn's disease, as the more nonspecific antigens were shown to give equal positive rates in sarcoidosis and Crohn's disease.

Adult↗
PubMed1975

Pneumoconiosis among the activated-carbon workers.

The prevalence of respiratory symptoms and chest radiographic and spirometric abnormalities was assessed among 397 employees of an activated carbon plant. Definite radiographic findings of pneumoconiosis, consisting of p-type, rounded opacities in the lower lung fields without firbosis or coalescence, were present in 9.6% of men and were related to cumulative dust exposure. Lesser degrees of radiographic abnormality suggesting pneumoconiosis were present in 11% of men and 2% of women. Spirometric values were substantially lower in blacks than in whites. However, cumulative dust exposure was not an important determinant of pulmonary function in either race. Review of lung biopsy speciments that had been obtained previously in two employees revealed extensive carbon depositiion but minimal associated fibrosis. Prolonged inhalation of activated carbon dust leads to pulmonary deposition of carbon and raciographic signs of pneumoconiosis; such deposition has little, if any, effect on respiratory symptoms or pulmonary function.

Adult↗
PubMed1975

The effect of metal ions on the atypical mycobacteria: growth and colony coloration.

The effect of 30 metal ions on growth and colony color has been evaluated for 215 isolates of "atypical" mycobacteria and 5 isolates of Mycobacterium tuberculosis. Of the total number of ions tested, ten proved to have a variable effect on growth and eight induced specific changes in colony coloration. Although both effects could be generally related to the Runyon grouping system, neither procedure proved to be practical or specific for differential identification of individual species. Spectrophotometric analyses of acetone extracts were made from representative strains of "atypical" mycobacteria, grown in the presence (test) or absence (control) of metal ions, in an attempt to determine the chemical nature of metal ion induced color changes in colonies of these organisms. Induced colors were not extractable with organic solvents, indicating that these colors are not lipid associated. In all cases where applicable (chromogenic strains) the naturally occurring carotenoid pigments were found to be unaffected, in their spectral properties, by the presence of metal ions even though the natural yellow color was frequently masked by the ion induced colors. The close association of metal ion induced colors with acetone nonextractable cell components suggests the presence of reduced metal ions or the formation of metal hydroxides. The apparent presence of several metal ion reductase systems and their physiological implications are discussed.

Metals↗