As the president of this congress of the Japanese Association of Rural Medicine, I would like to address you on some aspects of my contribution to the community from the viewpoint of agricultural medicine and rural health in the Tokachi district. The aspects of my contribution could be divided into three parts; one is relating to Farmer's lung, the next is to fatty liver, one of the important problems found by our physical check-up center, and the third is relating to reforms of the hospital management so as to meet the needs of the community with regard to medical care.
Farmer's lung is in my line since I have made a specialty of respiratory medicine. When I came to Obihiro 18 years ago, farmer's lung was prevailing. Farmers were in fear of the lung disease. I took it upon myself to cope with the epidemic. Group examinations for farmer's lung were initiated. We learned what state farmers were in and what should be done by way of prevention. Nowadays, farmer's lung is rare in this district.
As regards fatty liver, we have analyzed this pathophysiological aspect of steatosis of the liver with relation to obesity and hyperinsulinemia. In persons with fatty liver, significantly high blood levels of insulin after the glucose tolerance test was recognized. Hyperinsulinemia is well known as a risk factor for morbidity leading death. Fatty liver should be considered to be among high-risk factors for deadly diseases.
Thirdly about our hospital. Obihiro Kousei Hospital has been contributing so much to the Tokachi district. As the director of the hospital responsible for regional health care, I have encouraged our staff members to take good care of patients who visited our hospital. I have also endeavored to ameliorate our system to provide quick emergency care. The number of patients rushed to our emergency ward has been increasing as a result.
Finally, we would like to thank all the participants in the 51st Congress of the Japanese Association of Rural Medicine in Obihiro city.

Fifty cases of spontaneous pneumothorax treated in our hospital between 1988 and 1993 were reviewed. Forty-three cases were males and 7 cases were females. Treatments were broken down into rest cure for 11 cases and chest tube drainage for 39 cases. Of the chest tube drainage therapy cases, 30 could attained complete remission, but the remaining 9 cases required thoracotomy. In either case, the recurrence rates after the first pneumothorax and second attacks were 39% and 36%, respectively.
Stature and roentgenologically determined lung sizes were also examined in 34 male patients with spontaneous pneumothorax in comparison with those of 30 healthy men, who were age-matched control subjects. Among the significant findings was that the patients were much taller than the controls. The lungs were also significantly elevated in the patients compared with those of the controls. These results indicate that the patients liable to spontaneous pneumothorax are tall with their lungs housed high in the thorax compared to the ordinary people.

Prognostic facfors were examined in 71 patients receiving home oxygen therapy under the direction of our hospital between 1984 and 1994. In 25 patients who had undergone right catheterization, relationships between pulmonary hemodynamics and prognosis were also discussed. Mean pulmonary arterial pressure (P_PA) were correlated negatively with PaO₂. This indicated that hypoxic pulmonary vasoconstriction was the major cause of pulmonary hypertention in these patients. Pulmonary hypertention was revealed in 80% of the patients with P_PA ≥20 Torr and in 52% of the patients with P_PA ≥25 Torr. Acute hemodynamic effects of low-flow oxygen administration were investigated in 17 patients. PPA decreased significantly from 25.5 Torr to 23.5 Torr after oxygen administration and pulmonary arteriolar resistance (PAR) decreased from 243 dynes ·ses ·cm^-5 to 225 dynes·sec·cm^-5, but this change was not significant.
In patients with pulmonary fibrosis and sequelae of tuberculosis, the survival rates were lower than that of the patients with pulmonary emphysema. The median survival time (MST) for patients with cor pulmonale was significantly lower than that for those without cor pulmonale. When background factors were compared between the group with % home stay≥90% and % home stay<90%, there were no significant differences in observation periods, arterial blood gases and spirometry. The factors influencing % home stay were considered to be an important subject in addition to improving the survival rate.

We treated 472 patients with lung cancer from 1983 though 1993. Of the total number of the cases, early lung cancer accounted for 31 caces (6.6%), 6 of the hilar and 25 of the peripheral type. Of the 6 hilar type early lung cancer cases, 3 cases were detected by mass screening (2 cases were detected by sputum cytology). On the other hand, of the 25 cases of the peripheral type early lung cancer, 10 cases were detected by mass screening. All the 10 peripheral type early lung cancer cases detected by mass screening were detected by chest roentogenography. The 5-year survival rates for the hilar and peripheral type early lung cancer were 100% and 94.4%, respectively. For the improvement of prognosis of lung cancer, every effort should be made to detect lung cancer at an early stage. Careful lung cancer screening such as sputum cytology and bronchoscopy in a highrisk group and modern techniques such as helical X-ray CT are recommended for the increase in the detection of early lung cancer.

From April 1983 through March 1993, 10, 767 women underwent health examinations at the Health Care Center in Obihiro Kosei Hospital. Cervical smears were taken from theuterine cervix for cervical cancer screening. One hundred and six women had abnormal results, greater than class III. Those patients who were diagnosed as having carcinoma numbered 10 (0.09%). Of the cervical carcinomas found, 1 was frankly invasive (adenocarcinoma Ib); 3, microinvasive (2; squamous cell carcinoma and 1; co-existence of adenocarcinoma and squamous cell carcinoma); and 6, carcinomas in situ (squamous cell carcinoma).

From January 1981 through December 1986, 27, 513 individuals consisting of 17, 918 males and 9, 595 females underwent health examinations at Health Care Center in Obihiro Kosei Hospital. 14.2% of healthy and asymptomatic men and 29.1% of healthy and asymptomatic women had microscopic hematuria (one or more RBCs per HPF).
To evaluate the clinical significance of microhematuria, about one third of patients with asymptomatic microhematuria who had undergone complete urological examination were reviewed.
Genitourinary neoplasms were found in 0.21%(8 bladder cancers, 2 prostatic cancers and 1 renal cell cancer). The incidence of cancers increases proportionate to increase in age, furthermore, lesions were found more commonly in men than in women. We could find no relationship between the degree of hematuria and the cause. The results suggest that patients with asymptomatic microhematuria should undergo urological examinations.