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Biomedical subjects

J Suzuki

Publications and source records attributed to J Suzuki.

At least 631 records · Page 35Linked to original sources
PubMed1987

[Report on successful surgery of cavernous angioma in the dorsal part of the pons--usefulness of MRI in diagnosis].

A case with cavernous angioma which was located in the dorsal of the pons was cured surgically. A 16-year-old male was admitted with complaints of right motor and sensory disturbance. On neurological examination, the patient had right hemiparesis and hemiparesthesia, and right cerebellar signs. X-ray CT scan demonstrated a high density mass in the pons. Carotid and vertebral angiograms showed no abnormality. T1 and T2 weighted MRI clarified the pontine mass not as a tumor but a hematoma. Then, from the age of the patient, his clinical course, follow up X-ray CT and MRI findings, it was considered that a pontine lesion must have been an angioma with hemorrhage. Therefore, the operation was performed in an attempt to removal the hematoma and the mass of abnormal vessels in the dorsal part of the pons. Histological examination of the surgical specimen revealed abnormal vessels as a cavernous angioma. The postoperative course was uneventful.

Adolescent↗
PubMed1987

[Cerebral blood flow in moyamoya disease].

Regional cerebral blood flow in forty cases of moyamoya disease was investigated by intravenous 133Xe injection method. Twenty-one cases were children and other nineteen were adults. No or only slight neurological deficit were found at the CBF studies. CBF was calculated by initial slope index. For investigation of the relation between hemispheric blood flow and age, the regression curve was calculated and that with highest correlation was chosen. In normal group, the relationship between hemispheric CBF and age was correlated to following equation: y = 146.5-58.4 log x (r = -0.903). In contrast, in moyamoya disease, it was correlated to following equation: log y = 2.04-0.23 log x (r = -0.730). It can be said that CBF of the whole brain in moyamoya disease is below normal. The distribution of the rCBF was characteristic in moyamoya disease. There are low CBF values in the frontal and temporal lobes and relatively high values in the occipital lobes as compared with normal CBF distribution. These results are thought to indicate the importance of blood circulation to the brain from the vertebro-basilar arterial system. Moreover a comparison of these CBF results with the six stages of basal moyamoya seen angiographically was investigated in child cases. As the stage of moyamoya disease progressed, the hemispheric CBF decreased gradually and the distribution of blood flow gradually changed from a predominance of flow to the frontal lobes to a predominance of flow to the occipital lobes.

Adolescent↗
PubMed1987

[Correlation with lipid peroxidation, brain energy metabolism and brain edema in cerebral ischemia].

In order to unravel possible involvement of free radical reactions and lipid peroxidation in the ischemic cell damage, chemiluminescence, energy metabolism, water content and concentrations of Na+, K+ were measured with time, using highly ischemic whole brain models of rats. The amount of chemiluminescence value increased gradually with the ischemic load, and did markedly with recirculation of the blood flow. In the analysis of the intensity of chemiluminescence by wavelengths (the chemiluminescence spectroanalysis), the peaks were observed at 480, 520-530, 570, 620-640 and 680-700 nm. These wavelengths were taken to suggest the release of energy (luminescence) associated with the transition of singlet oxygen to the grounded state during the breakdown of the lipid hydroperoxide. When vitamin E was added on the brain homogenate in vitro, the luminescence was inhibited markedly for all the wavelengths mentioned above. With regard to the kinetics of energy metabolism, a short 5-minutes ischemic loading delayed recovery of adenine nucleotide after recirculation of the blood flow, and permitted ATP level to regain up to only about 60% of the pre-loading level. In case of the 5-minutes ischemic load, the cortical water content began to increase at 5 minutes after recirculation of the blood flow and showed sign of recovery in 30 minutes. The time-course increases in the cortical water content following recirculation of the blood flow well corresponded with the time-course changes in the amount of chemiluminescence value. And there seemed to be presented as the causes of ischemic cerebral edema not only the ATP-dependent lowering of activities of Na+, K+-ATPase, etc. by the free radicals, reinforced of the blood flow.

Adenine Nucleotides↗
PubMed1987

[Effect of septal lesions on the hippocampal EEG and behavior during DRL learning in the rabbit].

We had reported that hippocampal high frequent activity at 8-10 Hz (alpha-burst) appeared during approach and lever press with the progress of DRL learning. In this study, effect of bilateral septal lesions on hippocampal EEG (especially on alpha-burst) and behavior during 10 second DRL learning was investigated in thirteen rabbits. Using the atlas of Sawyer et al., bipolar electrodes were implanted chronically in bilateral septum at coordinates of A 1-2, L 1 and D 10-11 and dorsal hippocampus at P 3-5, L 4-6 and D 7-8. Septal lesion was made by using 8-mA DC currents for 15-50-sec period enough to abolish hippocampal theta activity. DRL learning was performed after septal lesions in five rabbits. In this group, acquisition of learning was disturbed and rhythmic slow activity of the hippocampus was markedly reduced. However, movement itself was not disturbed. Although hippocampal activity recovered gradually with the progress of session, alpha-burst was not observed by the 70th session. In eight rabbits, septal lesions were made after completion of DRL learning which required 40-50 sessions. In this group, the preservation of DRL learning was disturbed and relearning was not completed by the 30th session after septal lesions. Hippocampal rhythmic activity was remarkably reduced and alpha-burst was disappeared. But, voluntary movement itself was not altered. There are several theories concerning with hippocampal rhythmic slow activity. Some author emphasized that hippocampal rhythmic activity appeared at the time of voluntary movement and it had close relation to voluntary movement.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

[A case of von Hippel-Lindau disease showing only spinal cord symptoms].

A rare case of von Hippel-Lindau disease showing only spinal cord symptoms is reported. This 18-year-old boy was admitted to our clinic because of urinary disturbance, slowly progressive muscle weakness and sensory disturbance of his body and four extremities. Myelography demonstrated an expanding spinal cord and a figure of complete block of contrast medium at the lower cervical level. Dilated syrinx below the level of Th-3 was shown by delayed scan (19 hr.) of metrizamide CT myelography. These findings suggest that metrizamide could pass through the cord substance from the subarachnoid space into a syrinx cavity. Contrast enhancement CT scan revealed a slightly high density mass lesion at the level of Th-1 and a more marked tumor stain at the level of C-5 and 6. Syringo-subarachnoid shunt was done but the spinal intramedullary tumors were so deeply situated in the spinal cord that total removal of them was abandoned. The pathological diagnosis was hemangioblastoma. There were also a hemangioma at the right retina and multiple small tumor stains in the cerebellum, but they presented no clinical symptoms.

Adolescent↗
PubMed1987

[Results in oligodendroglioma: postoperative radiotherapy combined with chemotherapy].

The retrospective analysis of 39 cases of supratentorial oligodendroglioma included the years 1965 - 84. The 5-year and 10-year survival rates were 73.1% and 32.2%, respectively. Although oligodendrogliomas were benign tumor, the 10-year survival rate was not good. Recurrence of tumor appeared in 9 cases and some cases were noticed about 10 years after the treatment. So, long term follow-up is important for oligodendrogliomas. Our treatment for oligodendrogliomas was surgical removal and postoperative radiochemotherapy (radiation + ACNU + FT-207 + PSK) for several years. The previous cases who had only subtotal removal of tumor showed short survival time. On the other hand, the cases treated with postoperative radiotherapy or radiochemotherapy showed relatively good results.

Adolescent↗
PubMed1987

[Spontaneous arteriovenous fistula of the external carotid artery treated by a detachable balloon--a case report].

Spontaneous arterio-venous fistula (AVF) of the external carotid system is very rare. We successfully treated such a case by the detachable balloon method. The patient, a 2-year-and-9-month-old female who has no history of trauma had a pulsating mass at her right retroauricular region six months after birth. On admission to our clinic she was neurologically free except the pulsating mass (2 X 3 cm) with bruit and thrill. Selective right external carotid angiography revealed a high-flow simple AVF from internal maxillary artery to jugular vein. The normal blood flow of both the external and internal carotid system was decreased. Under local anesthesia, non-detachable balloon catheter was inserted to the internal maxillary artery by the transfemoral approach and inflated at the proximal side of the orifice of AVF until the vascular murmur in the neck disappeared. The balloon catheter was then exchanged with a detachable balloon catheter (Debrun, No. 9) which was inflated by silicone (0.4 ml), and was detached successfully. Follow-up angiography 1 year after the treatment revealed no recurrence of the fistula and almost branches of external carotid artery such as middle meningeal artery, occipital artery, superficial temporal artery and facial artery were clearly seen.

Arteriovenous Fistula↗
PubMed1987

[Cerebral protective effect of flunarizine in a canine model of cerebral ischemia].

Recently there is the hypothesis proposing that ischemic brain damage is associated with intracellular accumulation of calcium (Ca++). Therefore a variety of experiments have been carried out to investigate whether a Ca++-entry blocker was able to protect against brain damage caused by ischemia. The purpose of the present experiment is to study the protective effects of a Ca++ antagonist, flunarizine, on cerebral ischemia. In this experiment fifteen dogs were subjected to ischemia, using the "canine model of the completely ischemic brain regulated with a perfusion method" in which the cerebral blood flow (CBF) can be fully regulated. Five animals served as untreated controls, ten received treatment with flunarizine (1 mg/kg in five dogs and 3 mg/kg in five dogs, respectively). This agent was administered intravenously 20 minutes prior to the production of ischemia, when cerebral blood flow was reduced to one-tenth its normal value while monitoring CBF by means of a laser-Doppler flow meter. After one hour CBF was restored and the recovery of electrical activity of the brain and the degree of brain swelling were observed for three hours. At the end of the experiments, the degree of extravasation of Evans blue in the excised brain was examined. With regard to the recovery of EEG, no recovery of EEG was seen subsequent to recirculation except one dog in the control group. Whereas in the groups treated with flunarizine, remarkable recovery of EEG was found following recirculation in a dose dependent fasion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

[Breeding and growth of the inbred strain of seizure-prone Mongolian gerbils (Meriones unguiculatus)].

Recently a Mongolian gerbil has become a useful laboratory animal, while little of the basic data are known about the breeding and growth of this laboratory rodent. In our animal center, an inbred strain of the seizure prone gerbil has been produced and kept these ten years. The data on the breeding and growth of the animal were obtained and described as following in the present paper. The mean life span was 26 +/- 14 month old for males and 27 +/- 13 month old for females. The mean body weight of the Mongolian gerbils at 16 weeks of age was 72 +/- 5.6 g for males and 62 +/- 7.3 g for females. The mean litter size at birth was 4.8 +/- 1.7 head. (range; 1-9) More newborn pups were born in the warm seasons (March-October) than the cold seasons (November-February). The mean rate of weaning was 80.2%. The man litter size was relatively constant in each generation.

Animals↗
PubMed1987

[Pseudoaneurysm of the cortical artery associated with chronic subdural hematoma--a consideration on traumatic middle cerebral artery aneurysm].

A 62-year-old man was admitted to our hospital, since chronic subdural hematoma was showed after he complained of mild headache and nausea. Two years ago he had head trauma at the left parietal region after drinking. On admission there was no paresis and mild choked disc is detected. Computed tomography with contrast enhancement showed abnormal enhancement and left chronic subdural hematoma. Cerebral angiography showed an aneurysm of the angular artery. Operation was done and the aneurysm was trapped. Aneurysmal wall was histologically a pseudoaneurysm. Post-operative result was good. We considered the relationship between the cortical pseudoaneurysm and chronic subdural hematoma. We reviewed the traumatic middle cerebral artery aneurysm in the literature, 56 cases.

Chronic Disease↗
PubMed1987

[Regional cerebral blood flow in children--normal value and regional distribution of cerebral blood flow in childhood].

The changes in CBF and rCBF through the entire age range include the rapid period in childhood was reported. Sixteen children between the ages of 1 and 15 and 14 adults were studied. These 30 subjects were either volunteers of out-patients without CT and EEG abnormalities. rCBF was measured by the 133Xe intravenous injection method using Varmet rCBF analyzer. Ther relationship between age and CBF, the correlation coefficient was calculated based on the regression equations and the regression curve with the highest correlation was chosen. For the analysis of rCBF, he mean rCBF values (ISI) of 3 channels corresponding to the frontal, temporal, parietal and occipital lobes were expressed as a percentage of the hemispheric CBF. The hemispheric blood flow (ISI and CBF gray) of children less than 5 years of age was approximately twice that found in adults. This value decreased rapidly with age and in the 10-15 years the blood flow was approximately 1.3-fold that of adults. Thereafter, there was a slow decrease and a negative correlation with age was found. The decrease showed the correlation on the following equations; y = 146.5 - 58.5 log x. (r = -0.903) for ISI and log y = 2.26 - 0.29 log x. (r = -0.881) for CBF gray, which was statistically significant. In contrast, the CBF white showed a slightly higher value in the 1-2 years old children, but thereafter the CBF did not show a notable decreases with age. Through the entire age range, a best fit for the Fw values was found with : y = 18.3 + 37.5/x. (r = 0.798), which was also statistically significant.

Adolescent↗
PubMed1986

Combined effect of ACNU and 5-FU on rat glioma cells in spheroids and monolayer cultures.

Combined effects of ACNU and 5-Fu on rat glioma clone-6 cells grown exponentially as monolayers and in multicell spheroids (500-600 micron in diameter) were analyzed by the colony-forming assay. Cells in spheroids with central necroses were more sensitive to ACNU than cells in monolayer, although a large fraction of the cells in these spheroids was resistant to 5-Fu. The effect of ACNU was enhanced by the combined treatment with 5-Fu for cells in both spheroids and monolayers, and was more remarkable when 5-Fu was administered 24 hr prior to ACNU treatment. The enhancement was mainly due to a decrease in the number of spheroid-cells resistant to 5-Fu. Isobologram analysis indicated that the enhancement was supra-additive when a low concentration of 5-Fu was combined with a high concentration of ACNU. It is suggested that a low dose of 5-Fu combined with a high dose of ACNU may preferentially kill more cells in solid tumors.

Animals↗
PubMed1986

Evaluation of the analgesic effects of capsaicin using a new rat model for tonic pain.

An animal model for tonic pain has been produced by means of injecting monosodium urate crystals into a knee joint of rat hind paws in order to evaluate the analgesic effects of various drugs and analgesic methods and to elucidate the physiology of tonic pain. This model allows for stable and long-term behavioural changes due to tonic pain followed by complete recovery without tissue damages. It is advantageous in allowing for objective and quantitative evaluation of the effects of analgesics and should prove useful in research on pain and the development of pain therapy techniques. Using this model, the analgesic effects of capsaicin was evaluated when administered to the neonatal rat or locally to peripheral nerves. In both cases, significant analgesic effects were obtained.

Analgesics↗