Present situation of medical care for foreigners at medical facilities in Chiba City]

OBJECTIVE: The number of foreigners residing in Japan has increased during the past decade. The aim of this survey was to clarify the present situation and the disadvantages in the medical care for foreigners. METHODS: In October 1997, we mailed a questionnaire to all clinics and hospitals in Chiba City. The questionnaire included questions regarding the number of foreign patients who visited during the past three months, the proportion of patients who have any health insurance, procedures for handling foreign patients, and the disadvantages in medical care for them. RESULTS: Of the 210 respondents (183 clinics and 27 hospitals), 133 facilities (63.3%) provided medical care for foreign patients during the past three months, and 187 (89.0%) during the past year. In 102 facilities (76.7%), the number of foreign patients was fewer than 10 during the past three months. The mean number of foreign patients was 13.8 per facility (12.2 per clinic, and 23.5 per hospital). Of these foreign patients, 68.6% had any health insurance. In 172 facilities (81.9%), foreign patients were accepted in the same way as the Japanese. The main disadvantages in medical care for foreigners were difficulty in understanding because of communication problems, and default in payment of medical expenses for the foreigners with no health insurance. In 154 facilities (73.3%), no special preparation to communicate with foreign patients was provided, and few facilities could understand foreign languages except for English. In 20 facilities, fees for medical care had been left unpaid by foreign patients during the past year, and the total outstanding amount was about 23,800,000 yen. CONCLUSION: In Chiba City, many medical facilities provide medical care for foreign patients. This study suggests that support for communication with foreigners and compensation for default in medical expenses are necessary.     

Development of a possible nonmammalian test system for radiation-induced germ-cell mutagenesis using a fish, the Japanese medaka (Oryzias latipes).

To develop a specific-locus test (SLT) system for environmental mutagenesis using vertebrate species other than the mouse, we first established a tester stock of the fish medaka (Oryzias latipes) that is homozygous recessive at three loci. The phenotypic expression of these loci can be easily recognized early in embryonic development by observation through the transparent egg membrane. We irradiated wild-type males with 137Cs gamma-rays to determine the dose-response relationships for dominant lethal and specific-locus mutations induced in sperm, spermatids, and spermatogonia. Through observation of 322,666 loci in control offspring and 374,026 loci in offspring obtained from 0.64-, 4.75-, or 9.50-Gy-irradiated gametes, specific-locus mutations were phenotypically detected during early development. These putative mutations, designated "total mutation," can be recognized only in embryos of oviparous animals. The developmental fate of these mutant embryos was precisely followed. During subsequent embryonic development, a large fraction died and thus was unavailable for test-crossing, which was used to identify "viable mutations." Our medaka SLT system demonstrates that the vast majority of total mutations is associated with dominant lethal mutations. Thus far only one spontaneous viable mutation has been observed, so that all doubling calculations involving this endpoint carry a large error. With these reservations, however, we conclude that the quantitative data so far obtained from the medaka SLT are quite comparable to those from the mouse SLT and, hence, indicate the validity of the medaka SLT as a possible nonmammalian test system.     

Quantitative measurement of the basilar arterial flow in the dog-electromagnetic flow-meter study of the extra-and intracranial arterial occlusion (author's transl)]

Recent advances in microneurosurgery have markedly improved the result of surgical treatment of aneurysm and arteriovenous malformation in the posterior cranial fossa. However, more precise study on hemodynamics of the vertebro-basilar system may be necessary for further progress in treatment of the vascular lesions. From this point of view, the authors studied the basilar arterial flow of the dog by means of an electromagnetic flow-meter and the flow probe which was specially devised by the authors. (1) The ratio of absolute value of the mean basilar flow to the total brain weight was calculated, and the flow rate was expressed in ml/100 g brain/min. Mean value was 7.1 ml/100 g brain/min under normocapnea. (2) The effect of occlusion of the common carotid, of the external carotid, of the intracranial internal carotid, and of the extracranial internal carotid on the basilar flow was less remarkable in this order. (3) Under normocapnea, occlusion of the unilateral common carotid artery produced 115% increase in the basilar arterial flow. Bilateral common carotid occlusion resulted in 312% increase of the flow, demonstrating a remarkable ability of compensation of the basilar artery through the circle of Willis and leptomeningeal anastomoses. Under hypercapnea, unilateral common carotid occlusion was followed by 81% increase in the basillar flow. Occlusion of both common carotids caused 230% increase in the basilar flow. Percent increase in the basilar flow after unilateral or bilateral common carotid occlusion under normocapnea was significantly larger than under hypercapnea (p less than 0.05 and p less than 0.01 respectively). It may be supposed that under normacapnea the increased basilar flow following bilateral common carotid occlusion may compensate the decrease in total cerebral blood flow due to carotid occlusion. However, the compensatory rise in the basilar flow under hypercapnea may be not enough to supply the dilated vascular bed in the carotid and basilar territories. There might be even a risk of deficiency of blood supply in the territory of the basilar artery, if the vascular resistance in the carotid area could become less than that in the basilar. The significance of CO2 inhalation therapy for ischemic cerebral lesion was discussed. (4) After the both common carotid arteries were occluded, the basilar aretry was clamped temporarily. Following release of basilar occlusion, reactive hyperemia was observed in the basilar flow. Magnitude and duration of the reactive hyperemia increased progressively depending on duration of the basilar occlusion to some extent. The phenomenon may be best explained by a progressive accumulation of vasodilating metabolities in the ischemic area. (5) Unilateral vertebral occlusion caused 37% decrease in the basilar flow. Bilateral vertebral occlusion resulted in reverse of the basilar flow, averaging 61% of the original value in flow rate. (6) Occlusion of the unilateral subclavian artery produced "subclavian steal phenomenon"...     

Thallium-201 single photon emission tomography of intracranial angiomas

We herein describe thallium-201 single photon emission tomography (T1-201 SPECT) findings in three cases with intracranial angioma. One of the lesions which was associated with chronic encapsulated intracerebral hematoma showed moderate accumulation of T1-201, but, others demonstrated no accumulation. The usefulness and limitations of T1-201 SPECT in differential diagnosis of intracranial mass lesions are discussed.     

Real-time monitoring of glutamate following fluid percussion brain injury with hypoxia in the rat

In the present study, extracellular glutamate (Glu) was monitored in real time using an enzyme electrode biosensor following traumatic brain injury (TBI) either with or without inducing hypoxia in the rat. We also measured the cortical contusion volume at 3 days after insult by staining with 2,3,5-triphenyltetrazolium chloride (TTC). Male Sprague-Dawley rats (300-400 g) were anesthetized and then subjected to lateral fluid percussion (FP) brain injury of moderate severity (3.5-4.0 atm), using the Dragonfly device model (no. HPD-1700). The experimental animals were divided into four groups. Group 1 (n = 10) was subjected to TBI only, group 2 (n = 10) to TBI followed by 20 min of moderate hypoxia (FiO2: 10%), group 3 (n = 4) to 20 min of moderate hypoxia without TBI, and group 4 (n = 4) to sham. Seventy-two hours after the insults, the animals were sacrificed, their brains were stained with TTC, and the lesion volumes were calculated. A surge in the extracellular Glu concentration occurred immediately after TBI in groups 1 and 2. There was no significant difference between the two groups. Group 2 showed a prolonged efflux of Glu during hypoxia ( < 0.05). In group 3, Glu continued to show a mild increase. The cortical contusion volume in group 2 was significantly larger than that in group 1. To evaluate the possible involvement of apoptosis in groups 1 and 2, separate rats were sacrificed under the same procedures after 1, 6, 24, and 72 h after insult (n = 2/group). Immunohistochemical analysis demonstrated an increased number of both the cysteine protease caspase-3-positive cells at 24 h and TUNEL-positive cells at 72 h in group 2. These results suggest that TBI with moderate hypoxia induced the prolonged efflux of Glu, which thus resulted in more cortical damage due to necrosis and apoptosis.     

Early Experiences of Haemostasis on Brain Tumour Surgery with Argon Plasma Coagulation (APC)

Summary  Objective. We first applied a novel haemostatic strategy involving Argon Plasma Coagulation (APC), an innovative no-touch electrocoagulation technique in which a high-frequency alternating current is delivered to the tissue through ionized argon gas, to brain tumour surgery, and report its usefulness and limitations.  Methods. The APC system we used comprised an APC 300 developed by ERBE Elektromedizin GmbH, Germany. We applied APC to 13 brain tumours in 12 patients (5 meningiomas, 4 sarcomas, 2 glioblastomas, and 2 pituitary adenomas). To avoid unnecessary thermal injury to the tissue as much as possible, power/gas flow settings of 20 and 40 W were used. The impact time was varied individually but was around several seconds per one impact. The argon jet (1.5–4.5 L/min) clears a field of pooled blood and evenly conducts electrical energy to the target tissue. A thin and flexible probe particularly increased the usefulness of APC for haemostasis on deep-seated skull base tumour operations under a microscope.  Conclusion. All patients were successfully treated and satisfied with the surgical results without any complications due to APC. APC appears to be an excellent alternative strategy for achieving haemostasis on vascular-rich brain tumour surgery, and may be valuable for the management of patients with coagulation defects.     

Glial-derived growth factor signaling pathway in infantile hypertrophic pyloric stenosis

BACKGROUND/PURPOSE: Glial-derived growth factor (GDNF), which is the ligand of RET is reported to be essential for the development of enteric nervous system. A GDNF knockout mouse model has shown that the gastric region is a critical passing site between GDNF-RET-independent neuroblasts (colonizing the esophagus) and GDNF-RET-dependent neuroblasts (colonizing the small and large bowel). The earliest GDNF site of production is the mesenchyme and the outer smooth muscle cell (SMC) layer of the developing bowel. In the mature gastrointestinal tract the presence of GDNF is restricted to enteric glial cells. The aim of this study was to investigate the expression of GDNF and RET in infantile hypertrophic pyloric stenosis (IHPS). METHODS: Full-thickness muscle biopsy specimens were obtained from 8 IHPS patients at pyloromyotomy and from 8 age-matched controls without gastrointestinal disease. Indirect immunohistochemistry was performed using avidin-biotin-peroxidase complex method with anti-GDNF and anti-RET antibodies. Quantitative analysis was performed using sandwich-type enzyme-linked immunosorbent assay (ELISA) for GDNF. RESULTS: GDNF- and RET-positive nerve fibers were absent or markedly reduced in IHPS compared with controls. GDNF was expressed strongly by smooth muscle cells of both muscular layers in IHPS, whereas no GDNF expression was detected in pyloric muscle of controls. The quantity of total GDNF in IHPS was significantly higher than in controls (P < .01). CONCLUSIONS: The lack or markedly decreased number of GDNF-positive nerve fibers in IHPS supports the hypothesis of a selective immaturity of the enteric glia in the muscular layers in IHPS. The strong expression of GDNF in smooth muscle cells in IHPS and the increased levels of GDNF in IHPS suggest a compensatory mechanism by which the smooth muscle cells continue to produce GDNF until maturation of the enteric glial cells occurs.