Junichi Ishihara

Early diagnosis of tuberculosis by fibreoptic bronchoscopy

We carried out a retrospective study of the methods used to achieve an early diagnosis of 67 patients with pulmonary tuberculosis treated at our institute between 1984 and 1989. Sputum bacteriology was positive in 56 of the 67 patients, 22 were positive on microscopical examination of smears and on culture and 34 on culture alone. The 11 patients with negative sputum bacteriology were all diagnosed by fibreoptic bronchoscopy. In addition, 21 of the 34 smear-negative/culture-positive patients were examined by fibreoptic bronchoscopy and the initial diagnosis was made in 7 of these. Thus the initial diagnosis was made by sputum bacteriology in 49 cases and by fibreoptic bronchoscopy in 18 cases. The median number of days between obtaining a specimen and starting therapy was 7 days for sputum microscopy, 41 days for sputum culture, 7 days for microscopic examination of bronchoscopy specimens, 51 days for culture of the same and 19 days for biopsy. Fibreoptic bronchoscopy is therefore useful for the diagnosis of cases of tuberculosis in which tubercle bacilli are not detected in sputum and, in some instances, for an earlier diagnosis of smear-negative/culture-positive patients.

Detection of cytotoxicity of freshly obtained lymphocytes and of lymphocytes activated with recombinant interleukin II (rIL-2) against lung cancer cells lines by Human Tumor Clonogenic Assay (HTCA)☆

The cytotoxicity of freshly obtained human peripheral blood lymphocytes and lymphocytes activated with human recombinant interleukin II (rIL-2) was evaluated against lung cancer cell lines by the human tumor clonogenic assay. Colony formation of all human lung cancer cell lines, PC-1, 3, 6, 7, 9, 13 and 14 were suppressed by lymphocytes activated with 100 units/ml of human rIL-2 for 72 hr. However, the degree of the suppression of colony formation by lymphocytes activated with rIL-2 was different for each cell line. The per cent inhibition of colony formation obtained by HTCA correlated well with the per cent cytolysis obtained by 51Cr-release assay for all cell lines. HTCA provides a very useful tool for the detection of cytotoxicity of lymphocytes against clonogenic tumor cells.

Human Tumor Clonogenic Assay for Carcinoma of the Lung

The human tumor clonogenic assay (HTCA) has potential value for studies of both the chemosensitivity and biology of human tumors. However, many technical problems including low plating efficiencies and the preparation of sufficient numbers of viable cells remain. In this study, an improved method for disaggregation of solid tumors increased the yield of single cells. Consequently, more than 10 anticancer drugs could be tested in 94 of 168 specimens (56%). Removal of peripheral blood lymphocytes from cell suspensions derived from effusions also improved colony formation. Adequate growth for sensitivity testing (greater than 30 colonies/plate) was obtained in 122 cases (73%), inadequate growth for drug evaluation (5-29 colonies/plate) in 29 cases (17%), and no colony formation (less than 5 colonies/plate) in 17 cases (10%) of the 168 viable samples. The cloning efficiencies of cells derived from primary tumors (median 0.015%) were higher than those of cells derived from metastatic tumors (0.012%), and they varied with the location of the metastatic site. Cloning efficiencies varied markedly from specimen to specimen, and were unaffected by tumor histology, grade of differentiation, patient age, stage of disease, or prior chemotherapy. The HTCA is promising as a potential tool for studying the biology of tumors.

The different effects of recombinant human tumor necrosis factor on rat fibrosarcoma sublines.

SummaryThe antitumor effect of recombinant human tumor necrosis factor (rH-TNF) on two clones of rat fibrosarcoma with different metastatic potential to lymph nodes was examined. The colony formation of clone A, which has high metastatic potential, was completely inhibited by continuous exposure to rH-TNF at 50 U/ml. In contrast, colony formation of clone G, which has low metastatic potential, was not inhibited by high concentrations of rH-TNF (10,000 U/ml). The inhibitory effect of rH-TNF on colony formation by clone A was also observed with a 1-h exposure to rH-TNF. This effect was time and concentration dependent, as determined by the colony assay, 3H-thymidine uptake assay, and 51Cr-release assay. 3H-thymidine and 3H-uridine uptake per cell of clone A exposed to rH-TNF was not decreased. This suggests that the mechanisms of the antitumor effect of rH-TNF were not due to inhibition of DNA and RNA synthesis of tumor cells. In vivo growth and lymph node metastases of clone A inoculated i.p. to Donryu strain rats were completely suppressed by 14 consecutive i.p. injections of 105 or 106 U/kg per day of rH-TNF. On the other hand the growth of clone G was not influenced by rH-TNF administration.