To investigate whether the abnormality of short-latency somatosensory evoked potentials (SSEPs) in patients with focal brain lesions is enhanced by different stimulus frequencies, the median nerve at the wrist in 10 normal subjects and 12 patients with cortical (frontal, central and parietal) lesions was stimulated electrically at 1.3－18.3Hz. Normal subjects had decreased frontal P22－N30 and parietal P27 amplitudes at high (12.3 and 18.3 Hz) stimulus frequencies, whereas the N20 amplitude was relatively preserved. Dissociated loss of frontal P22－N30 occurred in patients with frontal lesions, but the preserved parietal components had characteristics similar to those of the non-affected side or of normal subjects at the various stimulus rates, which is evidence of an independent pathway for forming the frontal components. A N20 amplitude decrease occurred at high stimulus rates in the patients with central lesions, probably because of disturbed synaptic transmission. A paradoxical amplitude increase occurred at the high stimulus rates in patients with parietal lesions, which is indicative of inhibitory function loss in the sensory cortex or thalamo-cortical networks. In conclusion, change in the stimulus frequency is a useful method for detecting sensory process alteration in patients with focal cortical lesions.

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Pulmonary hypertension is one of the lethal complications in the antiphospholipid syndrome due to chronic recurrence of embolism or thrombosis. We experienced a 19-year-old man suffering from severe chronic thromboembolic pulmonary hypertension (CTEPH) caused by primary antiphospholipid syndrome. According to the guideline, pulmonary thromboendarterectomy was decided on after combined therapy with warfarin, beraprost and oxygen inhalation had not been effective enough to improve severe CTEPH. By an operation, the mean pressure of the pulmonary artery was decreased from 50 mmHg to 16 mmHg, while his New York Heart Association (NYHA) functional class classification significantly improved from class Ⅲ to class Ⅰ. We concluded that pulmonary thromboendarterectomy could dramatically improve hemodynamic indices, NYHA functional status and quality of life in patients with CTEPH.

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We report preoperative virtual images reconstructed from three-dimensional fast advanced spin echo (3D-FASE) and evaluate the cause of a trigeminal neuralgia due to an epidermoid tumor. A 60-year-old man had a 3-year-history of atypical trigeminal neuralgia in the left V2 region accompanied by a hypesthesia in the cheek. Neuroimaging demonstrated an epidermoid tumor in the left cerebellopontine cistern. As the preoperative virtual images reconstructed from 3D-FASE images indicated that the superior cerebellar artery compressed the trigeminal nerve at the root entry zone, we carried out total removal of the tumor and microvascular decompression of the trigeminal nerve. It was possible to visualize the fine structures around the trigeminal nerve, because an epidermoid tumor shows a high intensity mass on 3D-FASE images. The simulated 3D images were useful in deciding upon the additional microvascular decompression surgery for trigeminal neuralgia after total removal of the epidermoid tumor.

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We report a tailored temporal lobectomy for surgical treatment of medically intractable temporal lobe epilepsy. Surgery was conducted on 30 patients with temporal lobe epilepsy, 15 of whom required intracranial electrode placement. A precise skin incision had to be designed when subdural electrodes were placed, taking into consideration the electrodes' size and where they should be placed. Drawing of the Sylvian line and Rolandic line using Taylor's method on the patient's scalp provided useful information to determine the place of craniotomy. Fundamental surgical techniques and tips are described, including how to open the inferior horn after minimal removal of the lateral temporal cortex, and the introduction of a newly developed needle electrode combined with the ring type for recording electrocorticography from the exposed hippocampal surface. Twenty-three patients with mesial temporal epilepsy were treated surgically and the surgical results of 20 patients followed-up for more than one year (mean 44 months) were analyzed. Eighteen patients (90%) were seizure free (Engel classⅠ), and 2 patients were categorized as having a significant seizure reduction (class Ⅲ). Despite the good surgical results to date, further follow-up is needed to evaluate the long-term surgical effects.

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The methods for assessing VDT workload based on individual capabilities are necessary to evaluate general fatigue by VDT work. We have developed a new computer program for assessing data entry performance of each individual. Four healthy male volunteers conducted a data entry task at their own pace using this program under a controlled environment. They performed the task for 30 minutes twice with 10 minutes rest between them. As a result, the average number of inputs was 133.2 characters/min in the first task and 129.1 characters/min after taking the rest. The error rate was 8.6% and 10.6% in each task. This program was useful to evaluate their data entry performance. We also reported our concern with a drop in nasal skin temperature that was observed during these VDT tasks.

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Most organic solvents used in the workplace are mixed solvents consisting of several components. It is therefore very important to know the equilibrated vapor concentrations in order to control the work environment. In this study, the vapor-liquid equilibrium for multicomponent organic solvents is estimated by introducing the activity coefficients, which are calculated with the UNIFAC (Universal Quasichemical Functional Group Activity Coefficient) model. For two-component solvents, that is, the toluene-methanol and o-xylene-methanol systems, the calculated values of the vapor fraction and the equilibrated vapor concentrations are in good agreement with the reference ones. For three- or four-component solvents that are used as thinners, the calculated values are also generally in good agreement with the reference ones.

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Formaldehyde is a flammable, colorless and readily polymerized gas at ambient temperature, and is one of the major pollutants in indoor air. Medical students during their dissection course are exposed to formaldehyde, whose exposure is recently considered to be one of the causes of multiple chemical sensitivity. To understand the system that produces exposures and to plan for implementing control options, this study examined formaldehyde exposures that occurred in the gross anatomy laboratory. Formaldehyde in air was sampled by an active 2,4-dinitrophenylhydrazine (DNPH)-silica gel cartridge, extracted with acetonitrile and analyzed with an high performance liquid chromatograph-ultraviolet (HPLC-UV) detector. The geometric mean formaldehyde concentration was 20〜93 ppb in the anatomy laboratory before starting the anatomy dissecting. After beginning the dissecting, however, the highest geometric mean concentrations were 1012〜1380 ppb. Significant differences were observed during the exposed period for symptoms of "unusual thirst", "burning eyes", "itchy eyes", "bad feeling", "fatigue", etc. in comparison with the non-exposed period. These results show that medical schools should take more concrete measures to reduce exposure to formaldehyde.

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Gas productions in illegal dumping sites and waste landfills have caused serious problems. The gas production was induced by bacterial flora inhabited soils. In order to construct a culture independent evaluation system of the soil bacteria, bacterial communities were analyzed quantitatively and qualitatively, about 16 soil samples at 4 sites, both using culture and culture-independent methods. The real time PCR method was developed for counting total bacterial number. Sequencing analysis of 16S rDNA amplified by a direct PCR method revealed that non-spore forming sulfate reducing bacteria and sulfur-oxidizing bacteria were detected at a similar frequency at an illegal dumping site near mountains. On the other hand, spore-forming sulfate reducing bacteria and Clostridium sp. were mainly detected in deep samples at reclaimed landfills from the sea, whereas sulfur-oxidizing bacteria was hardly detected. The result regarding sulfate-reducing bacteria was confirmed also by an anaerobic culture method. Culture-independent molecular analyses of soil bacteria would give us useful information for prediction of gas production and for the evaluation of soil equilibrium.

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The occupational safety and health management system (OSHMS) has been introduced into many companies and factories in Japan. However, there are certain factories that are considering the introduction of OSHMS, while other factories are not interested in it. In the factories which have introduced OSHMS, occupational health activities are still insufficient. Passage by which OSHMS was introduced into Japan and a basic way to advance OSHMS is described in this paper. In addition, for OSHMS to spread to many companies in the future, and to achieve good results, the themes and prospects which should be examined are described. The themes shown in this paper are as follows: risk assessment, revision of the law and regulation, system auditing, individual management of safety and health rules, evaluation of the low concentration exposure influence, appropriate job suitability system, training of the expert, the support organization, supporting small and medium-sized scale factories.

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University of Occupational and Environmental Health (UOEH) conducts three courses in post-graduate education of occupational health (OH). Graduates of UOEH who have already received a basic education in OH can participate in any course and are trained to play an appropriate role as an occupational physician (OP). We operate the training program to provide practical knowledge and skills as well as to encourage interest in occupational health and to promote a further understanding of the role of the OP. In this study we evaluated changes in attitude of participants and the effectiveness of our program by an anonymous questionnaire. The subjects were all 19 participants of the 3-month program conducted between September 2003 and February 2004 as a part of the postgraduate education following several years of clinical experience. They were expected to be occupational physicians with a clinical specialty. The data were collected from questionnaires handed out at the beginning and the end of the program. The questionnaire included 8 items on the attitude toward occupational health. The subjects answered the questions according to a scale of 1 to 7. Data analysis was performed using the unpaired t-test by SPSS. The results suggested that our training program had a positive effect on trainees. Interest in occupational practice (P ＜ 0.05) and willingness to act as a full-time occupational physician in a large company (P ＜ 0.05) increased significantly. When considering the positive correlation between willingness to act as an OP and interest in a field that has some overlap between the speciality and occupational health, it was thought that developing a vision as an OP with respect to their career was important for training. However, in some clinical fields it may be difficult to define a relationship between the clinical speciality and occupational health. Understanding the role of an OP (P ＜ 0.05) and self-confidence in playing an appropriate role as an OP (P ＜ 0.05) also showed significant improvement. On the other hand, fourteen of the trainees (74%) did not have enough confidence to play a role as an OP even after completion of the program. In this study, the questionnaire we used was anonymous and did not include items concerning various attributes of the subjects. Therefore it was not possible to analyze changes of attitude at the individual level. We recognize the need to improve the program and are preparing a new version of the educational program with emphasis on understanding company organization activities and practical skills for problem solving. Opportunities to consider association between clinical speciality and occupational health are also included in this new version. We hope that the new program will further encourage trainees.

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The purpose of this study was to clarify the learning of the students who participated in an elderly person simulation experience study. We analyzed the aspects of the students' understanding of an elderly person and the role of a caregiver using the records maintained by the students during their simulation experience study. Based on the results, the students' understanding of an elderly person was classified under six categories, that is, 1) the physical phenomena of aging, 2) the effect of physical phenomena on the activities of daily living (ADL), 3) influence of the vital functions on an elderly person's physical function and health, 4) the effect on the mental state, 5) the constraint on the other persons, and 6) the change in the social status and relationships. The role of a caregiver was classified under two categories ; that is, 1) the activities and role of the caregiver, and 2) the adjustment to the environment. In this study, the students perceived not only the physical difficulties but also the emotional and sensitivity levels of the aged. In conclusion, it is thought that the elderly simulation program is effective in developing a better understanding of the physical state of the elderly as well as the importance of providing them with support.

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