In 1996, our medical school introduced symposium-style learning that is focused on recent advances in medical science as a regular undergraduate program for 6th-year students. The goals of this program are as follows: 1) to teach that good scientific research is essential to support high-quality medical education and medical care, 2) to have students enjoy research in a way they cannot in the ordinary curriculum, and 3) to stimulate interest in research in medical students who may become researchers in the future. Although a long-term survey is needed to evaluate the effects of this kind of learning strategy, an analysis of questionnaires showed that it was effective for the intended purposes. Today, the content of medical education has become diversified, and the social demands on medicine have changed greatly. Thus, we believe it is necessary to develop an education program separately from traditional ones that are primarily oriented to transmission of knowledge.

The relationship between bone strength and bone quality in rats fed with a low-magnesium (low-Mg) diet was examined. Twenty four-week-old male Wistar rats were divided into a control group (n = 10) and a low-Mg group (n = 10). Each group was fed with a conventional diet or a low-Mg diet (Mg, 6 mg/100 g diet) for 8 weeks, respectively. After the rats were sacrificed, bone strength, bone mineral content (BMC) and three-dimensional (3D) trabecular structure of the lumbar vertebra were measured, respectively. The results showed that the values of the BMC were almost the same between the control and the low-Mg diet groups. On the other hand, the bone strength of the low-Mg diet group was significantly lower than that of the control group (p < 0.01). 3D trabecular structure analysis showed a significant decrease (p < 0.05 or 0.01) in the trabecular structure of the low-Mg diet group as compared to the control group. These findings suggest that the bone strength in this model is not affected by the BMC but is strongly affected by the trabecular structure. The low-Mg diet model is considered to be an excellent model for examining bone quality.

Three patients, who received infrarenal aorto-iliac bifurcation grafts, complained of flaccid and insensible feeling on lower extremities immediatedly after surgery. These symptoms were supposed due, in two cases, to spinal cord ischemia or, in remaining one case, to ischemic change of the peripheral nerve, In former cases, spinal cord hypoxia might be caused by interrupted blood supply through spinal artery as it was intercepted temporarily but for about three and a half hours during surgical procedures. In the latter case, cramping of the left iliac artery lasted for five and a half hours, which might result in anoxic damage of the peripheral nerve. Hyperbaric oxygenation (HBO) at two atmospheric absolute (ATA) pressure for 75min and 3 ATA for 90min were repeated everyday for them. In all cases, almost complete sensorimotor recovery was obtained after 15 to 30 instances of HBO, which was combined with physical therapy. HBO seemed to have improved early hypoxic and edematous damages of the spinal cord or peripheral nerve. As an unfavorable complication of abdominal aortic surgery, incidence of sensorimotor disturbance of the extremities is infrequent and/or unpredictable, however, once it occurs, no effective therapeutic maneuvers were developed yet. Through these clinical data, HBO should be introduced more actively for such disorders. One of the key issues to enhance the effect of HBO is that, HBO should be introduced as soon as possible once postoperative nuerologic disorders were diagnosed.

The purpose of this study was to investigate the fluctuation of the recovery period of autonomic nervous activity (ANA) after isokinetic exercise. Sixteen male subjects participated in this study after they turned in their consent forms.The subjects performed isokinetic knee extension-flexion exercise using BIODEX. We obtained the electro-cardiogram during the entire experiment. We calculated their heart rate (HR) and power spectral of R-R interval (LF is low frequency component, and HF is high frequency component. Both indexes were converted to a logarithm transformation as to lnHF and lnLF.) from pre-exercise period (PRE) and post-exercise period (POST).Some researchers reported that ΔlnHF of POST was lower and ΔLF/HF of POST was higher than those of PRE immediately after aerobic exercise; however, this study's results were in complete contrast.In conclusion, we found that the recovery periods after aerobic and isokinetic exercises of ANA are entirely different.

Patients with an aortic root pseudoaneurysm communicating to the right atrium are rare. A 67-year-old woman underwent ascending aorta and total aortic arch replacement for acute type A aortic dissection at our institute 9 years prior to the current presentation. She was transported to our emergency department with complaints of chest pain, palpitations, and cold sensation. A continuous murmur was heard at the right sternal margin. Contrast-enhanced computed tomography (CT) and ultrasonic cardiography showed a huge pseudoaneurysm at the proximal anastomotic site and an aorto-right atrial fistula. Ascending aortic replacement with concomitant direct closure of the fistula was successfully performed. The patient was discharged in good condition on the 14th postoperative day. Careful follow-up with CT is important after acute type A aortic dissection repair.

In order to study respiratory transients during exercise, we examined breath-by-breath differences between gas exchange kinetics measured at the mouth and those estimated at the alveolar level. The gas exchange data at the mouth were obtained by measurement of expired gases only (expiratory flow method) . Correction for breath-by-breath changes in lung gas stores was applied to the total gas exchange, which was obtained by subtracting expired from inspired gas volume (alveolar gas exchange method) . Constant work loads (150, 200, 250 W) and a ramp work load (30 W/min) preceded and followed by a 50 W load were generated by a computerized cycle ergometer. Best-fit first- or second-order model values for gas exchange kinetic parameters were found by the non-linear least-squares method.
1. Regardless of work intensity and forcing function, the breath-by-breath variation in gas exchange measured at the mouth was larger than the gas exchange estimated at the alveolar level, in both a non-steady state and a steady state. The variation was caused by the invalidity of assuming zero N₂ exchange at the mouth, which was attributed to changes in lung volume.
2. Vo₂ kinetics at the alveolar level were faster than those at the mouth, while the converse held for Vco₂ at the onset of constant load work, due to the effects of fluctuations in lung gas stores on the kinetics of gas exchange at the mouth. During ramp load work, Vo₂ and Vco₂ kinetics at the alveolar level were faster than those at the mouth.
3. Steady state gas exchange values at the alveolar level and at the mouth were the same during constant load work, since the lung gas stores corrections added up to small fractions of the total gas exchange when summed over the long term.
4. Consideration of both the proper end-expiratory lung volume and ventilationperfusion inhomogeneity was required in order to estimate the true alveolar gas exchange.

This paper deals with general survey of hot spring curative treatment at Higashine Spa, Yamagata Prefecture, and the effect of this spa on the capillary resistance and the variation in the blood pressure.
The results of the medical survey are summarized as follows:
1) Higashine Spa consists of saline weak common salt springs, in each of which chemical components are almost the same.
2) The visitors to this spa are inhabitants of Yamagata Prefecture, farmers being the largest in number.
3) Most of them (78%) are old men and women over 50 years of age, and the number of women are four times that of men.
4) The examination of spa visitors reveals that hypertension stands at the top. However, in most cases, the chief complaints are of rheumatic disorders in natwe and hypertension is found at the time of medical examination.
5) Those who bathe five times a day are the largest in number.
6) Those who noticed the bathing reaction are small in number. The bathing reaction may be considered as a serious thermal crisis.
7) Bathing in this hot spring increases the capillary resistance and lowers the blood pressure.
Accordingly, bathing in this spa, under a proper guidance, may be effective in the treatment of hypertension. For balneal treatment of hypertension, physicians' directions as to how and when patiens should bathe, will be necessary: unplanned bathing cannot be approved of.

The results of our general and medical survey are summarized as follows:
(A) About Shinjo Spa
1) Most of visitors to this spa are residents of Yamagata Prefecture and engaged in agriculture.
2) In age they are 20 to 50.
3) Visitors who are few in number came to this spa for the purpose of spa treatment. Most of them visit this spa for recreation.
4) Most visitors take bath 2 to 3 times a day.
5) The bathing reaction and its effect are obscure, because most visitors do not stay here long enough for observation of the effect. It is, however, verified that this spa is effective in keeping the body father warm for a long time.
(B) About Niiyama Spa
1) Most visitors are residents of Yamagata Prefecture and those from neighboring prefecture are small in number. Half of visitors are farmers.
2) Most visitors are old in age, male and female visitors are almost equal in number.
3) The larger number of visitors come here for balneotherapy of or rehabilitation from diseases, especially neuralgia, rheumatism.
4) Most visitors are conscious of the good effect of bathing, but those who are conscious of thermal crisis are relatively few in number, being 9.8% of the total number of visitors.
The authors are indebted to the Pharmaceutical Section, Sanitation Bureau, Yamagata Prefectural Office and the Sanitation Section, Shinjo City Office for assistance given to the present survey, and to Shinjo and Niiyama Spa Associations for careful cooperation.

[Purpose] The effects of experimental osteoporosis on the trabecular bone structure of the mandible in cynomolgus monkeys were examined by radiological bone morphometric analysis. [Methods] Ovariectomy (OVX) was performed on twelve 10-year-old female cynomolgus monkeys, which were fed a controlled diet for 2 years. Twelve monkeys in a sham control group were fed under the same conditions. Using a microfocus tube and computed radiography, the removed mandibular bone samples were imaged by standardized magnification radiography, and two-dimensional digital imaging data were obtained. The structural parameters, such as skeletal area, perimeter, number, complexity, continuity and anisotropy, were measured using radiological bone morphometric analysis. The bone mineral density (BMD) was measured by dual energy X-ray absorptiometry. The width of the cortical bone was measured using magnified radiographic images. [Results] There were no significant differences between the OVX and the sham control groups in the skeletal structure indicated by the skeletal volume, number, width, perimeter, complexity, continuity, separation and spacing. However, there were significant differences between the two groups in the BMD of the mandibular body, cortical bone width, anisotropy and some parameters of the skeletal continuity. Among these parameters, the difference in the thinning of the cortical bone was most significant. [Conclusions] Using two-dimensional digital radiographic image data, this study suggests that the cortical bone width is more useful than the trabecular bone structure as the morphologic parameter for diagnosis of osteoporosis in the mandibular body.