The usefulness of mobile insulator sheets for the optimisation of deep heating area for regional hyperthermia using a capacitively coupled heating method: phantom,simulation and clinical prospective studies

Purpose: To evaluate the feasibility and efficacy of deep regional hyperthermia with the use of mobile insulator sheets in a capacitively coupled heating device.

Materials and methods: The heat was applied using an 8-MHz radiofrequency-capacitive device. The insulator sheet was inserted between the regular bolus and cooled overlay bolus in each of upper and lower side of the electrode. Several settings using the insulator sheets were investigated in an experimental study using an agar phantom to evaluate the temperature distributions. The specific absorption rate (SAR) distributions in several organs were also computed for the three-dimensional patient model. In a clinical prospective study, a total of five heating sessions were scheduled for the pelvic tumours, to assess the thermal parameters. The conventional setting was used during the first, third and fifth treatment sessions, and insulator sheets were used during the second and fourth treatment sessions.

Results: In the phantom study, the higher heating area improved towards the centre when the mobile insulator sheets were used. The subcutaneous fat/target ratios for the averaged SARs in the setting with the mobile insulator (median, 2.5) were significantly improved compared with those in the conventional setting (median, 3.4). In the clinical study, the thermal dose parameters of CEM43°CT90 in the sessions with the mobile insulator sheets (median, 1.9?min) were significantly better than those in the sessions using a conventional setting (median, 1.0?min).

Conclusions: Our novel heating method using mobile insulator sheets was thus found to improve the thermal dose parameters. Further investigations are expected.     

Lifestyle, mental health, and awareness of health among Japanese bus drivers

To examine lifestyle, mental health and awareness of health, a self-administered questionnaire survey was performed among 751 employees of a bus company in a rural city of Japan. From 597 (79.5%) respondents, we analyzed 130 male bus drivers and age-matched 130 male clerks. The questionnaire included eleven questions about lifestyle and mental health, three questions about awareness of health, and questions on personal concern about specific parts of the body or diseases, and health information they needed. Answers for lifestyle and mental health were classified into the categories of "good" or "not good" practices recommended by Breslow and Morimoto. The results were as follows; 1) Over 80 percent of subjects of both groups had good awareness of health, but bus drivers had significantly worse lifestyle with regard to nutritional intake (p < 0.05), daily walking (p < 0.001), sports (p < 0.05), and sleeping hours (p < 0.001). 2) Bus drivers had significantly greater prevalence of concern about their cardiovascular system, esophagus and gastrointestinal system, and joints and bones than clerks (p < 0.05). 3) Bus drivers had a significantly greater need for information about nutritional intake (p < 0.001), and methods for prevention of diseases (p < 0.01). From these results, the discrepancy between awareness of health and lifestyle seen in this study, especially in food intake, walking time, sports participation, and sleep, may have resulted from the bus driver's characteristics of job, for example, long and irregular working hours. Therefore, effective guidance on health and lifestyle changes to restore balance and improve their lifestyle.     

Malignancies of human thyroid tumors and dynamic magnetic resonance imaging (MRI)

Time intensity curves for gadolinium-diethylene triaminepentacetic acid (Gd-DTPA) enhanced magnetic resonance imaging (MRI), namely dynamic MRI, were determined for thyroid diseases and compared with findings of histopathologic examination. Time intensity curves for solid lesions were determined, excluding cases with secondary changes such as calcification, hemorrhage, necrosis and fibrosis. Three different patterns of time intensity curves were observed: rapid washout, delayed washout and no change. In our previous study, malignant grades of thyroid tumors were estimated immunohistochemically by epidermal growth factor receptor (EGFR) antibody. In most of malignant diseases and a few benign diseases that had marked cell proliferative activity with staining EGFR strongly, the time intensity curve displayed a delayed washout pattern, in which intensity was above 1/2-maximal value within 10 min after injection Gd-DTPA. Almost all benign diseases and a few well differentiated carcinomas displayed a rapid washout pastern, in which intensity was decreased to lower than 1/2 of peak grade within 10 min following injection and showed staining EGFR weakly. Benign diseases showing no change of time intensity curve, did not almost show aEGFR positive cell. These findings suggested that the time intensity curve obtained from dynamic MRI might indicate differentiated grades and cell proliferating activity of thyroid tumors.     

A case of acute cervical epidural hematoma mimicking medial medullary infarction complicated by arterial dissection]

A 67-year woman with hypertension rapidly noted weakness of the right upper and lower extremities with posterior cervical pain. At admission to our hospital, she showed right hemiparesis without facial palsy, and bilateral pathological reflex. Chest X-ray demonstrated enlargement of the mediastinal shadow. We suspected that she developed aortic arch dissection extending into the vertebral arteries and subsequent medial medullary infarction. However, enhanced thoracic CT, brain MRI-DWI and MRA examinations were negative. Her symptoms rapidly recovered three hours after the onset. A cervical MRI study revealed cervical epidural hematoma locating between the C3 and C6, which suppressed right side of the spinal cord. In conclusion, cervical epidural hematoma as well as medial medullary infarction complicated by the vertebral arterial dissection should be urgently explored when a patient had a sudden onset of cervical pain and hemiparesis without facial palsy.     

Changes in arousal level by differential exercise intensity

OBJECTIVE: The purpose of the present study was to investigate the influence of exercise intensity on arousal level. METHODS: Twelve subjects (22-33 years) performed a S1-S2 reaction time task consisting of warning stimulus (S1) and imperative stimulus (S2) in a control condition, and again after low, medium, and high intensity pedaling exercises. During this task, contingent negative variation (CNV) and spontaneous electroencephalogram before S1 were measured as indicators for arousal level. RESULTS: CNV amplitude after high intensity pedaling exercise was significantly smaller than after medium pedaling exercise. Compared to the control condition, relative power value of alpha waves increased after the high intensity exercise. CONCLUSIONS: These results suggested that arousal level was reduced after high intensity exercise and reached a state near optimal level after medium intensity exercise. The findings also suggested that changes in CNV amplitude by differences in exercise intensity followed an inverted-U shaped dose response curve. SIGNIFICANCE: The present study supported the view that CNV amplitude and arousal level followed an inverted-U relationship. It is concluded that differences in exercise intensity influenced arousal level.     

Motor denervation of tumors of the head and neck: changes in MR appearance.

PURPOSE: We reviewed the MR appearance of motor denervation of the third (mandibular) division of the trigeminal nerve (V3) and of the hypoglossal nerve. METHOD: Six cases of tumor of the head and neck with motor denervation were retrospectively evaluated. These comprised two patients with V3 denervation, three patients with hypoglossal nerve denervation, and one patient with both V3 and hypoglossal denervation. The observation was conducted for 6 to 44 months after onset. In denervated muscles, changes in signal intensity in T(1)- and T(2)-weighted images, degree of contrast enhancement, and volume of muscle were estimated during the follow-up period. RESULTS: In all cases of V3 denervation, the muscles showed no change in signal intensity in the T(1)-weighted images up to three months after onset. In two cases of hypoglossal denervation, the tongues appeared ipsilaterally hyperintense in the T(1)-weighted images within the first three months. In one case with V3 denervation and two cases with hypoglossal denervation, denervated muscles appeared hyperintense in the T(2)-weighted images up to three months after onset. At three months after denervation, the signal intensities of all motor-denervated areas increased in both T(1)- and T(2)-weighted images. Postcontrast T(1)-weighted images obtained within the first three months displayed contrast enhancement of all denervated muscles. In three cases of V3 denervation, the volumes of the affected muscles were reduced after the first three months. In three cases of hypoglossal denervation, the ipsilateral volume of the tongue decreased at three months after onset. CONCLUSION: Up to three months after onset, the denervated muscles appeared hyperintense in the T(2)-weighted images and contrast enhancement in postcontrast T(1)-weighted images before fatty infiltration and volume loss were apparent. Familiarity with the MR appearance of denervated muscles accompanying tumors of the head and neck is important to avoid confusion with inflammatory or neoplastic processes.