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Biomedical subjects

N Kita

Publications and source records attributed to N Kita.

At least 37 records · Page 2Linked to original sources

[Studies on the nontuberculous lung mycobacteriosis in Japan. (Report of the study in the year 1987 and 1988 of the Mycobacteriosis Research Group of the Japanese National Chest Hospitals)--pulmonary infection caused by Mycobacterium kansasii has begun to appear in all over Japan including north Japan Hokkaido].

UNLABELLED: In this study, the Mycobacteriosis Research Group of the Japanese National Chest Hospitals (MRG) presents the reports of study years 1987 and 1988. As reported previously**, pulmonary infection caused by Mycobacterium kansasii occurred principally in South-West Japan (prefectures South-West of Tokyo) and did not appear in North Japan. However, this disease appeared in 1987 and 1988 in Hokkaido (Sapporo Hospital). Accordingly, we may say the disease occurs all over Japan. This is a noteworthy finding newly recognized in the study years. The prevalence rate of nontuberculous lung mycobacteriosis was determined as 2.92 or 2.78 in 1987 and as 2.02 or 1.91 in 1988 per 100,000 population per year. The estimated rates based on the ratio of nontuberculous lung mycobacteriosis against active lung tuberculosis and based on the ratio of nontuberculous lung mycobacteriosis against culture-positive lung tuberculosis well agreed with each other. COMMENT: In this country, chest physicians customarily report their cases of nontuberculous mycobacteriosis including lung tuberculosis, because the payment of treatment for patients with tuberculosis is free. Because of this custom, tuberculosis statistics surely contain cases of nontuberculous mycobacteriosis. Caution about this has been paid in calculating the prevalence rate. From the study year 1987, the MRG chairman moved from Michio Tsukamura, The National Chubu Hospital, to Nobuhiko Kita, The National Kinki Chuo Hospital.

Humans↗

Asbestosis: high-resolution CT-pathologic correlation.

High-resolution computed tomography (HRCT) was performed in seven inflated and fixed postmortem lungs from seven asbestos-exposed patients with pathologically proved asbestosis. The parenchymal abnormalities seen at in vitro HRCT included thickened intralobular lines (n = 7), thickened interlobular lines (n = 7), pleural-based opacities (n = 7), parenchymal fibrous bands (n = 5), subpleural curvilinear shadows (n = 4), ground-glass appearance (n = 4), traction bronchiectasis (n = 4), and honeycombing (n = 2). The thickened intralobular lines were shown histologically to be due to peribronchiolar fibrosis. Thickened interlobular lines were due mainly to interlobular fibrotic thickening in four lungs and edema in three. The peribronchiolar fibrosis was most severe in the subpleural lung regions, creating curvilinear line shadows and pleural-based areas of opacity. Some subpleural fibrosis extended proximally along the bronchovascular sheath to create bandlike lesions. Areas of ground-glass appearance on HRCT scans were shown to be the result of mild alveolar wall and interlobular septal thickening due to fibrosis or edema. Postmortem HRCT findings were similar to premortem HRCT findings and correlated well with the pathologic findings of asbestosis.

Aged↗

Radiographic type p pneumoconiosis: high-resolution CT.

High-resolution computed tomography (CT) was performed in 90 patients with pneumoconiosis who had small rounded opacities on radiographs. The CT appearances of radiographic type p small rounded opacities in 55 patients were compared with the appearances of type q and r opacities. Radiographic type p pneumoconiosis on high-resolution CT scans was characterized by tiny binary branching structures or a gathering of a few dots. In 21 of the 55 patients, nonperipheral, small areas of low attenuation with a central dot were found. On the basis of CT-pathologic correlation in two postmortem specimens, these tiny opacities and areas of low attenuation corresponded to irregular fibrosis around and along the respiratory bronchioles and to focal-dust emphysema, respectively. Focal emphysema was most commonly found in pneumoconiosis with p-type changes and can be identified with high-resolution CT scanning. The addition of high-resolution CT to chest radiography is useful in achieving more accurate categorization of the lesions.

Humans↗

Diffuse panbronchiolitis: evaluation with high-resolution CT.

High-resolution computed tomography (CT) was performed in 20 patients with diffuse panbronchiolitis. Images of abnormal peripheral lung were classified into four types: small nodules around the end of bronchovascular branchings (CT type I), small nodules in the centrilobular area connected with small branching linear opacities (CT type II), nodules accompanied by ring-shaped or small ductal opacities connected to proximal bronchovascular bundles (CT type III), large cystic opacities accompanied by dilated proximal bronchi (CT type IV). CT classifications were compared with radiographic classifications and clinical stages of the disease. The comparison revealed that the classification based on CT findings reflected the clinical stages and pathologic process of diffuse panbronchiolitis. The authors conclude that high-resolution CT is useful in the evaluation of both the location and severity of the lesions.

Adult↗

Studies on the epidemiology of nontuberculous mycobacteriosis in Japan.

The epidemiology of mycobacterial disease in Japan changed considerably over the period 1971 to 1984. During this time, the incidence of pulmonary disease caused by Mycobacterium tuberculosis has steadily declined; disease caused by M. avium complex has remained stable; disease caused by M. kansasii has increased considerably; and, for the first time, substantial numbers of cases caused by M. szulgai, M. fortuitum, M. chelonae, and M. nonchromogenicum have been reported. From 1981 to 1984 the incidence of pulmonary nontuberculous mycobacterioses (NTM) was estimated at 1.73 +/- 0.25 cases per 100,000 population per year; of these, M. avium complex constituted 1.29 +/- 0.24 and M. kansasii 0.34 +/- 0.11 per 100,000 per year. The prevalence of the NTM was relatively high in southwestern Japan (industrialized, warm climate) and low in northern Japan (rural, cold).

Age Factors↗

A study of the taxonomy of the Mycobacterium nonchromogenicum complex and report of six cases of lung infection due to Mycobacterium nonchromogenicum.

In numerical classification, four species of the Mycobacterium nonchromogenicum complex, Mycobacterium nonchromogenicum, M. terrae, M. novum, and M. triviale, formed one cluster. These four species appeared to be reduced to one species, Mycobacterium nonchromogenicum. Furthermore, relationships between the species were numerically analyzed by using the hypothetical median organism pattern. The results showed that the M. nonchromogenicum complex can be divided into two subgroups: M. nonchromogenicum and the other three. These two subgroups were differentiated from each other by scores based on two or more positive reactions in the following three characteristics: resistance to bleomycin (5 microgram/ml); heat-stable acid phosphatase activity; nicotinamidase or pyrazinamidase activity or both activities. M. nonchromogenicum gave two or three positive reactions among these three, and M. terrae, M. novum, and M. triviale gave two or three negative reactions. Three cases of lung infection due to M. nonchromogenicum, as well as three other cases of probable lung infection due to M. nonchromogenicum, were observed in this study. Only one organism isolated from one doubtful case was M. terrae. Up to now, M. nonchromogenicum was considered a nonpathogen. It was shown, however, that this organism causes lung infection in humans.

Acid Phosphatase↗