[Occupational lung diseases other than asbestos- and indium-related disease].

In our country, pneumoconiosis used to hold an overwhelmingly majority in respiratory occupational lung diseases. Although the number of pneumoconiosis cases has been decreasing certainly, new cases have been arising even today. In addition, in place of pneumoconiosis or asbestos-related diseases, occupational asthma has become the most common forms of occupational lung disease in many industrialized countries. Occupational asthma has been implicated in 9 to 15% of adult asthma in the United States. Although the environmental causes of occupational lung disease are clear, the mechanisms of the diseases are not fully understood and need to be further elucidated.

Progression of pneumoconiosis in coal miners after cessation of dust exposure: a longitudinal study based on periodic chest X-ray examinations in Hokkaido, Japan.

BACKGROUND: The progression rate of pneumoconiosis in retired coal miners over ten years has not been studied in Japan. METHODS: A retrospective longitudinal study was undertaken using chest X-rays of 1091 pneumoconiosis subjects in Hokkaido, Japan between 1985 and 2005. RESULTS: The final numbers of subjects were 207 (19% of the entry) after 1 decade and 85 (8%) after 2 decades. Sixty-two percent of 207 subjects after 1 decade and 29% of 85 showed progression in 2 decades. Thirty-one percent of ILO category 1 and 55% of category 2 subjects showed progression to complicated pneumoconiosis after 1 decade, and 6% (4 of 64) of category 1 and 6% (5 of 77) of category 2 subjects progressed to complicated pneumoconiosis during 2 decades. CONCLUSION: The progression of pneumoconiosis was observed after the cessation of dust exposure, especially during the first 10 years.

Comparison of MET-PET and FDG-PET for differentiation between benign lesions and lung cancer in pneumoconiosis.

OBJECTIVE: The aim of this study was to evaluate and compare the ability of C-11-methionine (MET) and F-18 fluoro-deoxy-D-glucose positron emission tomography (FDG-PET) to diagnose lung cancer in patients with pneumoconiosis. METHODS: Twenty-six subjects underwent both whole-body MET-PET and FDG-PET on the same day. The first group was a lung cancer group, which consisted of 15 patients, and included those with pneumoconiosis with increased nodules (13 cases), hemoptysis (1 case), and positive sputum cytology (1 case). The second group was a no-malignancy control group, consisting of 11 patients with pneumoconiosis. RESULTS: Significant correlations between nodule size and the maximum standardized uptake value (SUV(max)) of the two PET tracers were observed in the control group. The larger the nodule size, the greater were the amounts of these tracers accumulated (MET: r = 0.771, P < 0.0001; FDG: r = 0.903, P < 0.0001). The SUV(max) of MET was significantly lower than that of FDG in the pneumoconiotic nodules (P < 0.0001). Lung cancer was found in 5 of 19 nodules (two with adenocarcinoma, one with squamous cell carcinoma, one with small cell carcinoma, and one with large cell carcinoma) in the first group. As for nodules equal to or less than 3 cm in diameter, the SUV(max) of MET was significantly higher in the lung cancer than in the pneumoconiotic nodules, with 3.48 +/- 1.18 (mean +/- SE) for the lung cancer and 1.48 +/- 0.08 for the pneumoconiotic nodules (P < 0.01), similar to the SUV(max) of FDG, with 7.12 +/- 2.36 and 2.85 +/- 0.24 (P < 0.05), respectively. On the basis of the criteria for the control group, FDG and MET identified lung cancer with sensitivities of 60% and 80%, specificities of 100% and 93%, accuracies of 90% and 90%, positive predictive values of 100% and 80%, and negative predictive values of 88% and 93%, respectively. CONCLUSIONS: Our results indicate that nodules with an intense uptake of MET and FDG relative to their size should be carefully observed because of a high risk for lung cancer.

[Clinical analysis of home oxygen therapy in patients with pneumoconiosis at Iwamizawa Rosai Hospital].

Although home oxygen therapy (HOT) has become one of the standard therapies in the management of chronic respiratory failure, especially for patient with hypoxia, there are very few studies about HOT in patients with pneumoconiosis. Therefore, we clinically investigated the characteristics of 97 patients with pneumoconiosis and 30 patients with COPD on home oxygen therapy (HOT) followed at Iwamizawa Rosai Hospital during the period from 1990 to 2003. The mean survival time in patients with pneumoconiosis (42 months) by the Kaplan-Meier method was shorter than in patents with COPD (75 months). Among the patients with pneumoconiosis divided by chest radiography classification of pneumoconiosis, there was no significant difference in mean survival time. The survival time in pneumoconiosis patients with dyspnea grade IV was shorter than in patients with dyspnea grade III.

[A case of chronic pulmonary paracoccidioidomycosis].

In a 43-year-old Japanese Brazilian who came to Japan in 2001, since subjective symptoms such as cough, sputum, and dyspnea on exertion had become severe, he was referred to our hospital because of suspicion of pulmonary tuberculosis in chest radiography and CT findings. A chest radiograph of initial examination showed interstitial shadows in both lungs with nodular, infiltrative or cavitary changes. No Mycobacterium tuberculosis was found. The mycetocyte with multipolar budding resembling the steerage of a ship, which was characteristic of Paracoccidioides was observed in sputum and transbronchial lung biopsy specimens. We cultured a fungus to show dimorphism of temperature dependency, and a diagnosis of chronic lung paracoccidioidomycosis was arrived at. By administration of ITCZ 200 mg/day, the chest radiography findings and clinical manifestations were improved. This case seems to be worthy of reporting in Japan since the affected site or organ was limited to the two lungs with multiple cavitary lesions and fibrotic changes on radiographic examination, and final diagnosis was made by cytology of sputum and pathology of TBLB specimens.