To clarify the role of bronchus-associated lymphoid tissue (BALT) in the delayed-type hypersensitivity (DTH) reaction in the lung, we examined immunohistochemically the dynamic changes of the cell type structure of BALT in rats with DTH reaction induced by secondary injection of BCG.
The lymphocyte subpopulations of BALT were determined with the indirect immuno peroxidase technique, using monoclonal antibodies and antirat immunoglobulin subclass-antibodies reacting with T-cell subpopulations and each surface Ig subclass B-cell.
The structure of the normal rat-BALT was similar to that of the rabbit or Peyer's patch of the rat, except that the development of germinal centers in the follicular area was not found in most of the BALT.
The induction of DTH reaction increased both the size of BALT and the number of germinal centers in follicular area in the early stage of the reaction, and subsequently resulted in granuloma formation in the parafollicular area in association with the development of granulomatous changes within the lungs. In the BALT, the ratio of W3/25-positive T-cells (T helper) to OX8-positive T-cells (T nonhelper) increased by 2.6 in the early stage of the reaction but decreased by 0.5 in the late stage (five weeks). On the other hand, in the early stage, the surface (s) IgM-positive B-cells and sIgA-positive B-cells increased in most compartments of BALT and within parafollicular area, in particular in the surrounding regions of highendothelial venules.
Therefore, the numbers of OX6-positive cells (Ia-positive cells) markedly increased in all area of BALT in the early stage. These increases suggest the involvement of not only B-cells but also activated T-cells and activated macrophages in BALT.
In addition, the fluctulation of immunoglobulin levels in bronchoalveolar lavage fluid was greater than that in serum.
These findings indicate that the changes of T-cell and B-cell subpopulations in BALT are closely associated with DTH reaction, and BALT modify the local immune response in the lung by cell-mediated immunity as well as humoral immunity.

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Results of the susceptibility testing of Mycobacterium avium complex strains to antituberculosis drugs have been shown to correlate with clinical efficacy of antituberculosis drugs in causing the conversion of sputum culture.Low minimal inhibitory concentrations of rifampicin, ethambutol, and isoniazid have correlated with the negative conversion of sputum culture (Table 1).This finding suggests that antituberculosis drugs are effective in the treatment of the disease caused by the M. avium complex.It has been shown furthermore that the susceptibility testing using the Ogawa egg medium should be read at 2 weeks after incubation.

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A study was conducted of the clinical features and bronchoscopic findings of 16 cases with tracheobronchial tuberculosis experienced over a 5 year period from 1981 at Nihon University Hospital.
Age of patient ranged from the twenties to seventies, and as 14 out of 16 cases were female, a high incidence of this disease in female was found to be characteristic in our study.The right upper lobar bronchus was found to be the most frequent location of the disease in our cases, whereas no difference in its frequency between the right and left sides of the bronchus was noted.Various types of bronchial lesions, such as the solitary, skip and continuous types, were observed by bronchoscopy.The most frequent subjective symptoms were coughing, sputum and pyrexia, and objective findings were crackling and wheezing.
The bronchoscopic findings were classified according to Ono's classification of types I to IV.Five cases were type III (ulcers with granulations) and 4 cases were type N (scar formation with stenosis).Accordingly, and the fact shows that a number of cases were diagnosed endoscopically in advanced stage.In addition, 6 cases were mixed types such as types II+III, III+IV and VI+I.Through chemotherapy using anti-tuberculous agents, the endoscopic findings improved satisfactorily, although the efficacy of corticosteroid was doubtful for the prevention of bronchial stenosis.
From the clinical study of our 16 cases, we speculate that tracheobronchial tuberculosis is not an independent disease but is rather a disease spreading mainly from a pulmonary tuberculous focus through the bronchus.

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Two regimens of chemotherapy for pulmonary tuberculosis were compared: -6RHS (continuing treament for further 6 months after the nagative conversion of sputum by culture) and 6RHZ (duration of treatment was 6 months irrespective of the duration of sputum negativity). As shown in Table 6, there was no relapse among 52 patients treated with-6RHS regimen, and one (1.4%) among 71 patients treated with 6RHZ during the first two years after the cessation of chemotherapy, and the difference in the relapse rate was not statistically significant. All patients mentioned above were sensitive to both rifampicin and isoniazid, not complicated with diabetes mellitus and/or tuberculous empyema, and treatment was completed without interruption or if any within 2 weeks.
The authors reviewed results of all short-course chemotherapy studies hitherto been carried out in the author's hospital from the stand point of the duration of culture negativity. All 741 patients who satisfied the above three conditions were divided into the two groups by the regimen of chemotherapy with and without PZA. As shown in Fig.2, the relapse rate in the first 2 years after the cessation of chemotherapy was 0% (0 out of 4 cases with PZA) and 8.3% (1 out of 12 cases without Z) in cases with negativity for 4 months or less;0.9% (1 out of 109 cases with Z) and 5.7% (5 out of 87 cases without Z) in cases with negativity for 5 months;and no relapse was seen in both groups in cases with negativity for 6 months and more. The fact indicates that there was no significant difference in the relapse rate during the first two years after the cessation of chemotherapy between cases treated with and without PZA when the duration of culture negativity was the same.
It is recommended to decide the duration of chemotherapy based on the duration of culture negativity, preferably 6 months or more.

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It is said that miliary tuberculosis has recently been increasing, and there are several reports on cases presenting ARDS-like acute respiratory insufficiency leading to death. In our hospital, 14 out of 15 such cases experienced in recent years have recovered, and we examined possible factors involved therein with particular emphasis on diagnosis and treatment.
[Subject]
Study subjects are 15 cases of our inpatients, and the diagnosis was confirmed bacteriologically and/or histologically in 14 cases, and by the response to chemotherapy in one case.
[Results]
These 15 cases were composed of 9 males and 6 females, and 9 were in the age group 60-69, and the average age was 57.9 years. Past history and family history of tuberculosis were recognized in 5 cases (33%) each, and underlying diseases were pulmonary carcinoma, rheumatoid arthritis (RA), silicosis, hepatocirrhosis, cardiac insufficiency, etc. Pregnancy was considered to be a disposition in one case. No definite relation was seen with profession of cases. Most frequent symptoms were pyrexia (87%), next cough (40%) and dyspnea (33%). Period of time from admission to diagnosis averaged 7.3 days. Diagnosis made at the first examination was miliary tuberculosis, pneumonia, cardiac insufficiency and meningitis in 5 (50%), 3 (30%), 1 (10%), and 1 (10%) out of 10 cases, respectively. Chest X-ray revealed typical bilateral lung diffuse micro-nodular pulmonary shadows and atypical shadows in 11 (73%) and 4 (27%) cases, respectively. Tuberculin reaction was negative in 8 and doubtful in 2 cases and positive in only 3 (23%) out of 12 cases tested. As approaches to positive diagnosis, tubercles were found from bone marrow cell block in 7 (58%) out of 12 cases examined, TBLB was positive in 3 out of 6 cases, and funduscopy revealed choroidal tubercles in 5 out of 12 cases. Sputum smear and gastric smear were positive in 2 (14%) and 1 of 14 cases, respectively, and none was positive on urine. Cases treated with combined use of 3-4 antituberculous drugs and some steroid preparations represented 60% (9 cases) of 15 cases. Excluding one case died 4 hours after admission, all other 14 cases (93%) were cured.
[Discussion and conclusion]
Aggravation of general condition due to delayed diagnosis, and exacerbation of tuberculosis due to single use of steroid preparation, have been pointed out as major causes of death from miliary tuberculosis. If the onset of the disease is ARDS-like acute respira tory insufficiency, its prognosis is usually serious. In our subjects, miliary tuberculosis is suspected on admission, it took only 7.3 days on the average for its positive diagnosis. A certain less-invasive tests are important for early positive diagnosis when general condition of the patient is considered. In this connection, it is worth while to mention that examination of bone marrow cell block and funduscopy succeeded in proving tubercles in 83% of the cases. For those cases presenting acute respiratory insufficiency, early use of steroid preparations together with antituberculous agents led to an improvement of Pao2 as high as more than 10 mmHg or more in 8.2 days on the average. In miliary tuberculosis, both early diagnosis and treatment are needed, and combined use of some steroid preparations is useful for the treatment of the complicated acute respiratory insufficiency.

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Cases of infections due to M. asiaticum, M. shimoidei and M. simiae and bacteriologic characteristics useful for identifying these organisms are reviewed.
M. simiae can not be identified only by a positive niacin test, because there are a few strains of Mycobacterium avium-M.intracellulare complex which show a positive niacin reaction. In laboratory tests, key characters for identifying M. simiae are the following three: 1) strongly positive niacin production;2) tolerance to 0.2% picric acid in a modified Sauton agar medium, in which sodium glutamate is substituted for asparagine; 3) utilization of succinate as carbon source in the presence of ammonical nitrogen. The latter two characteristics are originally characteristic for rapidly growing mycobacteria. However, only M. simiae is an exceptional case of slowly growing mycobacteria.With these characteristics, M. simiae is identified without employing serological testing.

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A newly developed DNA probe for Mycobacterium avium and M. intracellulare (Gen-Probe^®;Gen-robe Corp., San Diego, Calif.U.S.A.) was evaluated for its applicability for identification and classification of M.avium complex (MAC), using reference strains of serovars 1 to 28.The DNA probe for M.avium was found to hybridize to ribosomal RNA of MAC belonging to serovars1-6, 8-11, and 21, showing the % hybridization values of 33.7 to 43.3%.On the other hand, the DNA probe for M.intracellulare hibridized to the MAC belonging to serovars 7, 12-20, and 25 at the level of 30.3 to 35.9%.The organisms of MAC belonging to serovars 22-24 and 26-28 failed to bind any of the two DNA probes at the% hybridization rate greater than 10%, which is a borderline for positivity of specific hybridization.Therefore, on the basis of the extent of specific hybridization with the Gen-Probe^®MAC is thought to be divided into three groups;the organisms belonging to M.avium (serovars, 1-6, 8-11 and 21), those belonging to M.intracellulare (serovars, 7, 12-20 and 25), and those differentiated from the above two species.The Gen-Porbe Diagnostic System for MAC using the DNA probes was confirmed to be very useful from the viewpoints of accuracy and reproducibility of the data and easiness and rapidness of the assay procedures.

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