Background: Enamel matrix derivative placed in the backs of rats induces numerous eosinophilic round bodies (ERBs) and hard tissue. ERBs were analyzed by matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and by database analysis. Subsequently, a seven-amino-acid sequence was identified, and an artificial oligopeptide was synthesized with its sequence. The present experiment was carried out to clarify whether or not the peptide induces hard tissue formation in vivo.Methods: Synthetic oligopeptide was injected into the backs of 15 rats. After injection, the tissues were excised at various times and prepared for light and immune-light microscopy.Results: A white lump was macroscopically observed in each rat back 14 days after injection of 7.5 and 15 mg/mL synthetic oligopeptide, and endochondral ossification and bone formation were microscopically observed in one rat back 14 days after injection of 15 mg/mL synthetic oligopeptide.Conclusions: The synthetic oligopeptide is pure, 1,118 dalton, and apparently low-toxicity. It seems to produce hard tissues, such as cartilage and bone tissue.

The outstanding feature of the drift of population observed in our country of late is understood in terms of the population exodus from rural areas into urban or industrial areas, which brings about. a conspicuous decrease in rural population especially in that of the younger working age bracket. with a view to clarifying an aspect of such wide-ranging migration of population, a study was made in the three remote mountain villages in the Chilbu District, where people are living on an extremely low economic level Investigation conducted for eacch respective economic level revealed an even. abnormally advanced decrease in the population of such younger generation, far advanced than in average rural areas. Thus the unfavorable topogra-phical conditions, lack of cultivating lands, low income, etc.were considered to be responsible for the acceleration of such population exodus. Attention was also drawn to the fact that not only the surplus labor power but even many of the eldest sons. who are the successors to their fathers' occupations are turning to urban areas for employ-ment, threatening the possibility of the replenishment of agricultural labor power and the development of agricultural economics, as well as the future reproduction of population in rural areas.

Three essential factors of the sympathetic nervous functions, sympathetic nervous tone (β-, α-secretion), adrenoceptor sensitivity (β-, α-sensitivity) and adrenergic manifestations, were assessed integratedly by the sequential administration of specific adrenoceptor agonists and blockers. The examination procedures were designed to provide all parameters under the blockade of the autonomic regulation without affecting the basic sympathetic nervous functions.
Decrease in β- and α-secretion associated with the increase in β- and α-sensitivity in patients with diabetic neuropathy, idiopathic orthostatic hypotension and cervical radiation myelopathy were exactly compatible with the autonomic dysfunctions of them and convinced the validity of the methods. Synchronized firings of the sympathetic nerves of the cardiovascular system and harmonized regulation of the adrenoceptor sensitivity were shown by the positive correlations between β- and α-secretion and between β- and α-sensitivity, respectively. Negative correlations between “secretion” and “sensitivity” over wide ranges of these parameters suggested that the concept of denervation hypersensitivity was not specific for patients with organic autonomic neuropathies but was commonly avairable for usual subjects in proportion to the sympathetic nervous tone of the individual subject.

Between January, 1975 and June, 1990, 67 patients underwent surgical treatment for infective endocarditis at our hospital. Of 67 patients, 27 patients showed active endocarditis at the time of operation. In these 27 patients, 20 had active endocarditis of the native valve (NVE), and the seven had active prosthetic valve endocarditis (PVE). The interval between onset of infective endocarditis and operation ranged from 7 to 252 days (mean, 36 days). In the operative results, 3 of 20 patients (15%) with NVE and 2 of 5 patients (40.0%) with PVE died before discharge from the hospital. According to analysis of preoperative hemodynamic state and bacteriological data, the determinant factors of operative mortality and morbidity were preoperative NYHA functional classification, the interval between onset of infection and operation, and annular destruction (annular abscess). Patient's age, preoperative renal function, positive blood culture, the site of infection, and positive culture or stain of the surgically excised valve did not play an important role to determine operative mortality and morbidity. It is our conclusion that all patients with infective endocarditis who develop progressive congestive heart failure and echocardigraphical extravalvular infection despite medical treatment, should have prompt valve replacement.

One hundred and thirty cases of closed mitral commissurotomy were followed for up to 25 years and 10 months. There was no operative death, but 31 cases died during the follow-up period. Eight cases died suddenly of unknown cause, 7 due to heart failure, 5 due to thromboembolism, 4 on reoperation, and 6 due to other reasons. In the 7 cases who died of heart failure late after commissurotomy, 3 cases refused reoperation. Each of the remaising 4 cases were not operated on because of associated severe liver dysfunction, left ventricular dysfunction plus pulmonary hypertension, respiratory failure due to bronchial asthma, and unknown reasons, respectively. The actuarial survival rate was 93.6% 10 years after surgery, and 72.2% 20 years after surgery. Forty-two cases had reoperation with a mean interval of 12 years and 6 months. Reoperation-free survival rate was 88.7% 10 years after the first operation and 42.8% 20 years after the first operation. Incidence of major thromboembolism was 1.25%/patient-year. Thromboembolism and sudden death of unknown cause constituted the leading cause of late death and played a key role in long term results. Cardiac event-free survival rate was 65.7% 10 years after surgery and 32.6% 20 years after surgery. From these results it was concluded that the clinical limitations of the effectiveness of closed mitral commissurotomy was around ten years after surgery. We believe that these findings provide useful information for percutaneous transvenous mitral ommissurotomy.

The results of pulmonary function tests (PFTs) given to those inhabitants in the western part of Kanagawa Prefecture who visited our hospital for medical examinations between April 1991 and March 1992 were studied comparatively, with their occupation, age, sex, environmental factors and smoking habits taken into account. For this purpose, the subjects totaling 1, 322 were classified into three groups-those who live in the hilly area, those who live in the suburban area and those who live in the coastal area. In the present study, the results of the four PFT items-FVC, FEV 1.0%, FVC and FEV 1.0%-were checked. Careful examination brought into relief the startling fact that many aged people, non-farmers and nonsmokers in the suburban subject group have impaired pulmonary function. It is said that because of the Tokyo-Nagoya expressway and many other motorways, the air in the suburban area is fouled up with exhaust gas to a greater extent than in the other two areas. Although our finding alone could not identify the cause of impaired pulmonary function definitely, air pollution was thought to be a culprit. Further investigation should be made into the living conditions of the examinees. Moreover, environmental monitoring and data analysis have to be carried out in the future.

A 51-year-old man developed a high fever with congestive heart failure after treatment for his dental caries and was admitted to our hospital. Transesophageal echocardiogram showed severe aortic regurgitation with a bicuspid aortic valve where vegetation and perforation was identified on its leaflets. Infective endocarditis caused by Streptococcus constellatus was diagnosed by blood culture. A computed tomography scan of the chest showed enlargement of his ascending aorta with a maximum diameter of 5.0cm. After treatment with antibiotics and diuretics for 60 days, he underwent surgical treatment for his aortic valve and ascending aorta. After excising the diseased aortic leaflets with vegetation, a mechanical prosthetic valve (Carbomedicus 23mm) was implanted. His ascending aorta was also replaced separately with a woven Dacron tube graft. There was an anomalous origin of the right coronary artery which was detached from the ascending aortic wall as a button and was implanted on the tube graft. Histologically the aortic wall showed disappearance of elastic fibers with myxomatous degeneration in the media. Immunohistochemical staining also revealed that matrix metalloproteinase-2 (MMP-2) was strongly expressed in the aortic media. The postoperative course was uneventful and he was discharged on the 37th postoperative day.

  A 4–year trial of an undergraduate medical care education program for smoking cessation with the participation of simulated patients is described. Simulated medical care with the participation of simulated patients is thought to motivate medical students to learn clinical skills for smoking cessation. However, simulated medical care for smoking cessation is difficult to plan when both the medical students and the simulated patients are nonsmokers.