Search PubMed⌕ Search

Biomedical subjects

T Tsubokawa

Publications and source records attributed to T Tsubokawa.

At least 109 records · Page 6Linked to original sources
PubMed1990

Facilitated growth of transplanted raphe cells in hydrocephalic interstitial edema.

Fetal raphe cells were transplanted into the anterior corpus callosum (CC) of serotonin (5-HT)-denervated hydrocephalic rats. The levels of 5-HT and its metabolite, 5-hydroxyindoleacetic acid (5-HIAA), were measured in the anterior and posterior parts of the CC at 1-2, 5-6, and 7-8 weeks posttransplantation. The 5-HT and 5-HIAA levels in the anterior part were restored to their maximum within 5-6 weeks posttransplantation in both hydrocephalic and nonhydrocephalic rats. In contrast, the 5-HT and 5-HIAA levels in the posterior part continued to increase for the period beyond 5-6 weeks posttransplantation. The longer time course of the restoration in the posterior part may reflect the time for fiber growth from the site of transplantation to remote brain areas. Hydrocephalic rats showed slightly higher levels of 5-HT (154.4%) and 5-HIAA (159.5%) in the anterior part, and markedly higher levels of 5-HT (254.8%) and 5-HIAA (388.7%) in the posterior part at 5-6 weeks posttransplantation, compared with nonhydrocephalic rats. These results imply favorable effects of interstitial edema associated with hydrocephalus on the survival of transplanted raphe cells and fiber outgrowth.

Animals↗
PubMed1990

Spinal cord responses to feline transcranial brain stimulation: evidence for involvement of cerebellar pathways.

The physiological characteristics of spinal cord responses recorded from the spinal epidural space of the cat to transcranial brain stimulation were studied, in comparison with the spinal cord responses to direct stimulation of the motor cortex or cerebellum. The conduction velocity of the initial wave of the responses to transcranial brain stimulation (122.3 +/- 16.3 m/sec mean +/- SD, n = 5) was much faster than the conduction velocity of the initial wave of the responses to motor cortex stimulation (68.3 +/- 14.7, n = 5) and similar to the conduction velocity of the initial wave of the responses to cerebellar stimulation (120.2 +/- 16.2, n = 5). Furthermore, the conduction velocity of any component in the subsequent polyphasic waves at any intensity was not similar to the conduction velocity of the initial wave of the responses to motor cortex stimulation. All components of the responses to motor cortex stimulation disappeared after intercollicular transection. In contrast, the initial wave of the responses to cerebellar stimulation and transcranial brain stimulation remained unaffected by intercollicular transection. The initial wave caused by anodal transcranial brain stimulation was eliminated by ablation of the cerebellum. However, cathodal transcranial brain stimulation sometimes can produce an initial wave that can be eliminated only by transection at the medullospinal junction. The initial wave of the responses to cerebellar stimulation was largest in amplitude when the vicinity of the dentate nucleus was stimulated. These results suggest that responses to activation of the cerebellum, rather than corticospinal neurons arising from the motor cortex, represent a major component of the spinal cord responses to transcranial brain stimulation in cats. The data obtained indicate that it is difficult to activate the motor cortex selectively by transcranial brain stimulation in cats.

Animals↗
PubMed1990

Quantitative evaluation of hemiparesis with corticomyographic motor evoked potential recorded by transcranial magnetic stimulation.

Corticomyographic motor evoked potentials (MEP) activated by transcranial magnetic stimulation of the motor cortex provide clinicians with an opportunity to evaluate corticospinal motor systems quantitatively and noninvasively. Threshold, amplitude, and latency of the corticomyographic MEP, however, are variable between subjects mainly because current directions and intensities induced by magnetic stimulation cannot be determined precisely due to anatomical variations of subjects. The variability of corticomyographic MEPs has limited the use of corticomyographic MEP for evaluating mild changes in corticospinal motor function. In the present study, we used an internal standard to assess hemiplegia, expressing relative amplitude, latency, and threshold of responses on the paretic side as a function of responses elicited from the intact side (%MEP). Neurological function of paretic muscles, as determined by a muscle maneuver test (MMT), clearly correlated to %MEP threshold, amplitude, and latency. Since corticomyographic MEP are similar when recorded from symmetrical sites on two extremities of normal subjects, %MEP provided a sensitive measure of mild hemiparesis. The %MEP approach revealed abnormal MMT scores of 3 or 4 more frequently than did standard MEP approaches. %MEP amplitude was more sensitive to mild hemiparesis than %MEP latency or %MEP threshold. Since magnetic stimulation with a safe intensity range cannot reliably produce corticomyographic MEP in severely paretic muscles with MMT scores of 2 or less, the MEP appears to be most useful for evaluating mild hemiparesis. This technique should expand significantly the clinical usefulness of corticomyographic MEP in neurosurgical practice.

Adolescent↗
PubMed1990

Effects of interstitial edema on brain cell transplantation.

Fetal raphe cells were transplanted into the anterior part of the corpus callosum of serotonin denervated hydrocephalic rats using a cell suspension method. Hydrocephalus was induced by intracisternal injection of kaolin. The survival of the transplanted cells and fiber outgrowth were evaluated according to the level of serotonin and its metabolite, hydroxyindoleacetic acid, using high-performance liquid chromatography with electrochemical detection in the anterior and posterior parts of the corpus callosum 1-2, 5-6, and 7-8 weeks after transplantation. The results suggest favorable effects of interstitial edema associated with hydrocephalus on the survival of transplanted raphe cells and fiber outgrowth.

Animals↗
PubMed1990

Intra-arterial ACNU chemotherapy employing 20% mannitol osmotic blood-brain barrier disruption for malignant brain tumors.

The clinical effects and problems of intra-arterial water-soluble antitumor nitrosourea (ACNU) therapy following osmotic blood-brain barrier modification are discussed. Twenty-one patients with malignant brain tumors were divided into two groups. Group 1 consisted of 16 patients treated by operation, irradiation, and two or more courses of intracarotid infusion of ACNU 100 mg/body (1.7-2.2 mg/kg) following 20% mannitol 200 ml (1.3-1.6 ml/sec) (7 grade 4 astrocytomas, 5 grade 3 astrocytomas, and 4 others). Group 2 consisted of five patients treated by operation, irradiation, and repeated intracarotid infusion of ACNU 100 mg/body alone (grade 4 astrocytoma). The 2-year survival rate in Group 1 was 79% (11 of 14 cases followed up for longer than 2 years) and the 3-year survival rate was 67%. Five of seven grade 4 astrocytoma patients (71%) in Group 1 survived for more than 1 year 6 months, whereas four of five grade 4 astrocytoma in Group 2 died within 1 year 6 months. The measurement of the ACNU concentration in tumor tissues and blood in 11 brain tumors, after intracarotid infusion of ACNU with blood-brain barrier disruption, showed peak values in the tumor tissues of 3.02-32.53 micrograms/gm (mean, 9.67 micrograms/gm), about three to five times as high as that in blood in most cases. This method used in Group 1 appears to be relatively safe without permanent neurological deficits and offers a potential therapeutic effect when used in combination with appropriate premedication in suitable patients.

Adolescent↗
PubMed1990

Epithelial cyst of the fourth ventricle. Case report.

A case of epithelial cyst in the fourth ventricle of a 4-year-old child is described. A single epithelial layer with a clear basement membrane lining the cyst wall was observed. There were no prominent histological findings to suggest a pathogenesis for this cyst based on immunohistochemical or ultrastructural studies; however, the cyst fluid contained significant amounts of carcinoembryonic antigen. It is considered that the epithelial layer lining the cyst wall was possibly of endodermal origin.

Brain Diseases↗
PubMed1990

[Chemotherapy with ACNU and radiation therapy in malignant glioma in cerebral hemisphere of adult].

54 cases of malignant gliomas in adults localized in cerebral hemisphere including the location of basal ganglia and corpus callosum in 26% were survived over one month and followed more than 2 years after operation for 10 years recently. Histologically they had 40 cases of glioblastoma multiforme and 14 cases of anaplastic astrocytoma. All malignant gliomas were given an operation and radiation, classifying 4 groups due to chemotherapeutic methods; Group I (20 cases) was treated by intraarterial infusion of ACNU with 20% mannitol. The others were Group II (8 cases) treated by intraarterial infusion of ACNU only, Group III (13 cases) by intravenous infusion of ACNU only and Group IV (13 cases) by no chemotherapy. Post-operative survival rates in the malignant gliomas of Group I were that 1 year survival rate was in 16 out of 20 cases (80%), 2 years in 55%, and 5 years in 25%. In glioblastoma multiforme, 1 year survival rate of Group I was recognized in 70% and 2 years in 36%, a little better than the other treatments. 2 year survival rate of other treatments demonstrated 17% in Group II, 25% in Group III, and 11% in Group IV. CT findings of glioblastoma multiforme in Group I showed no rest tumor in 4 cases and one case of CR, and 3 cases of PR in the follow up study of 10 cases with rest tumor on CT after operation. There were no permanent complications except for temporary mild neurological deficit in 7% of Group I improving within 2 to 3 days after intraarterial infusion of ACNU and 20% mannitol. It is suggested that chemotherapy of Group I by intraarterial infusion of ACNU and 20% mannitol demonstrated a little better therapeutic efficacy than the other Groups, at least within 2 years after operation.

Adult↗
PubMed1990

[MCNU delivery into malignant brain tumor and normal brain tissue by intravenous or intraarterial infusion].

In 13 Fischer 344 rats transplanted intracerebrally with 9 L gliosarcoma, 13 normal Fischer 344 rats and 4 clinical cases of malignant glioma, a new water-soluble nitrosourea (MCNU) was given and the concentration was measured in blood, tumor tissues, normal brains around the tumors and normal hemispheres by intravenous or intraarterial infusion of MCNU. At 5 min. after administration of MCNU 20 mg/kg (4-5 mg/body) in 9 L gliosarcoma bearing Fischer rats, mean MCNU concentration in the blood was not different between 20 micrograms/ml intravenous and 23 micrograms/ml intraarterial administrations whereas that in the tumor tissues by intracarotid infusion of MCNU was 40 +/- 14.4 micrograms/g which was about two times as much as 22.9 +/- 8.13 micrograms/g by intravenous infusion of MCNU. Mean MCNU concentration of normal brains around tumor tissues was 2.49 micrograms/g in intravenous and 8.95 micrograms/g in intracarotid infusion. MCNU concentration of tumor tissues in 4 cases of malignant gliomas was higher by intracarotid administration than by intravenous administration compared to that in the blood. Maximum tumor/blood ratio of MCNU was 1.94 in intracarotid administration for the malignant glioma. It is suggested that intraarterial administration was more useful than intravenous infusion as an administration route for malignant brain tumors.

Animals↗
PubMed1989

Congenital unilateral hydrocephalus.

An 848-g infant delivered after a 30-week gestation had been diagnosed by ultrasonic examination as having a unilateral ventriculomegaly from the 29th week of gestation. Computerized tomography (CT) demonstrated a greatly dilated right lateral ventricle with no apparent space-occupying lesion within the ventricle and no passage of the contrast medium (metrizamide) through the foramen of Monro. The child was diagnosed as having unilateral hydrocephalus due to congenital obstruction of the foramen and underwent a ventriculoperitoneal shunt operation on day 49 (37 weeks and 5 days of amended gestation age; 1,420 g body weight). The postoperative course was uneventful and the patient was discharged on day 126 with no marked developmental retardation. Angiography carried out at 8 months postpartum revealed displacement and hypoplasia of the deep cerebral veins. The pathogenesis and treatment of unilateral hydrocephalus are discussed.

Female↗
PubMed1989

Fructose-added glycerol (Glyceol) for therapy of elevated intracranial pressure: analysis of the side effects of long-term administration in a multi-institutional trial.

The effects of long-term administration of fructose-added glycerol solution (Glyceol): 10% glycerol, 5% fructose, 0.9% sodium chloride; 600-2000 ml/d intravenously for 7-63 d) were evaluated in a multi-institutional trial involving 1346 cases. Improvement of the neurological signs and symptoms of elevated intracranial pressure was recognized by responsible physicians in close association with the administration of Glyceol (75.1%). The intracranial pressure measured directly also decreased in most cases following the administration of Glyceol (81.2%). No significant changes were observed in serum electrolytes and osmolarity at the end of the long-term administration. Unfavourable changes in clinical conditions which were considered very likely or suspected to be due to the long-term administration of Glyceol were recorded in 2 cases (0.1%) or 13 cases (1.0%), respectively. Most of these changes were abnormalities of serum electrolytes. It appeared, however, that the abnormalities of serum electrolytes may be readily correctable, and rarely induced if standard care of the serum water-electrolyte balance is carried out and unless too large doses are employed. Other changes appeared to be related more to preexistent complications and/or the administration of other drugs, rather than to the administration of Glyceol alone. Thus, administration of Glyceol appeared feasible for the therapy of elevated intracranial pressure over the long term.

Adult↗
PubMed1989

Regional disparity in the vascular response to subarachnoid hemorrhage--relationship between alteration of the concentration of eicosanoids and electron microscopic findings.

In an attempt to document the apparent regional disparity of the vascular response to subarachnoid hemorrhage (SAH), the authors measured the concentrations of eicosanoids in various arterial segments corresponding to alterations observed on electron microscopy, using cats with experimentally produced SAH. The level of thromboxane B2 was elevated in both the arterial walls and cerebral cortices, particularly in the latter, on day 7 after SAH production. The 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) levels in the SAH group were decreased in the basilar and pial arteries after the production of SAH. The mean concentration of 6-keto-PGF1 alpha in the cerebral cortices showed only slight, erratic changes. Ultrastructural observations revealed that the vessels of smaller diameter, such as the pial vessels, underwent more marked spastic changes than did those of larger diameter. These results suggest that the ischemic events following SAH may have been induced by vasospasm and increased coagulability caused by changes in the concentrations of arachidonic acid metabolites in arteries of relatively small diameter.

6-Ketoprostaglandin F1 alpha↗
PubMed1989

[Therapeutic efficacy of intracarotid infusion of 20% mannitol with ACNU in Fischer rats with intracerebrally implanted 9L gliosarcoma].

The purpose of this study was to investigate the therapeutic effect of intracarotid infusion of 20% mannitol with ACNU chemotherapy in Fischer 344 rats with intracerebrally implanted 9L gliosarcoma, compared with giving them only ACNU intraperitoneally. Thirty 9L gliosarcoma bearing Fischer 344 rats were evaluated in the following 3 groups. Group I: control (no treatment); group II: treated by ACNU 20 mg/kg intraperitoneally on the 7th day after implantation of 9L gliosarcoma cells; group III: treated by intracarotid infusion of 20% mannitol 3.1 ml/min. and with the same dose of ACNU as in group II. Mean survival time after the inoculation of tumor cells into the brain was 15.1 days (group I), 21.8 days (group II) and 27.9 days (group III). In group II all tumor-bearing Fischer rats died within 24 days after inoculation of tumor cells, whereas in group III 5 out of 6 rats survived more than 25 days after them. Group III evidenced necrosis and degenerative findings with vacuole and microcyst without vascular proliferation in tumor tissues more than group II on the 7th day after ACNU treatment for the experimental brain tumor. On the 7th day after ACNU treatment of each group, BrdU labeling index was calculated in order to evaluate tumor proliferation. The Mean BrdU labeling index in tumor cells of group III demonstrated 7.5%, against 14.5% (about one half) in group II. From our experimental study of survival time and BrdU labeling index, it is suggested that osmotic blood brain barrier disruption chemotherapy by intracarotid infusion of 20% mannitol and ACNU was more effective than simple treatment by intraperitoneal injection of ACNU in the Fischer rats with intracerebrally implanted 9L gliosarcoma.

Animals↗
PubMed1989

[Diagnostic value of neuron specific enolase (NSE) in the cerebrospinal fluid of malignant brain tumor with intrathecal metastasis].

Neuron specific enolase (NSE) in the cerebrospinal fluid (CSF) and serum of 54 cases of brain tumors, in the tumor tissues of 10 brain tumors and in the cyst fluids of 7 brain tumors was measured by radioimmunoassay with NSE measurement kit (Eiken Chemistry co.) NSE values in the cerebrospinal fluid of 35 malignant brain tumors showed abnormal increase higher than 10 ng/ml in 17 cases (about 50%) of them, whereas all of benign cases were lower than 10 ng/ml. The means and standard deviations of NSE in the cerebrospinal fluid of malignant tumors were 20.63 +/- 20.78 ng/ml in the astrocytoma grade 3 and 4, 19.73 +/- 15.5 ng/ml in the medulloblastoma and 12.4 +/- 8.9 ng/ml in the germ cell tumor. NSE values in the CSF of 12 brain tumors with intrathecal metastasis were 28.0 +/- 18.9 ng/ml (mean +/- SD) showing about three times as much as those without intrathecal metastasis. There was significant difference between these groups (p less than 0.01). All cyst fluids including in 7 cases of brain tumors demonstrated high values of NSE even if they were benign tumor and their NSE values in CSF were normal. NSE values of brain tumor tissues had no correlation with malignancy, but were higher in the periphery of the tumors than in the center. NSE values of CSF in brain tumors might be changed in relation with the improvement or deterioration on clinical state and CT. It might be suggested that the measurement of NSE in the CSF had significance as a monitor of therapeutic efficacy and prognosis for the brain tumors.

Animals↗
PubMed1989

[Percutaneous ethanol injection of parathyroid adenoma under US guidance].

A patient with post-operative recurrent parathyroid adenoma was treated with percutaneous injection of absolute ethanol under ultrasonographic guidance. Serum calcium and PTH level were both successfully normalized, while recurrent nerve palsy was encountered as side effect. Six months later, she was suffered from hyperparathyroidism again, because of local tumor recurrence. Her recurrent nerve palsy was cured at that time. This technic could be a simple and non-invasive alternative for the conventional surgical procedure, but the indication for larger adenomas like this case should be carefully considered.

Adenoma↗
PubMed1989

[Delayed radiation necrosis of the temporal lobe following radiation therapy of maxillary carcinoma].

A case of delayed radiation necrosis following radiation therapy for maxillary carcinoma was reported. The diagnosis of this case for the radiation necrosis was clinically suggestive and established by the pathological findings of autopsy. This 66 year-old man had been treated by the partial resection for the right maxillary carcinoma with chemotherapy (pepleomycin 110 mg, adriamycin 20 mg). Pre- and postoperatively total dose of 5040 rads were irradiated with cobalt therapy during 42 days at a dose of 180 rads and 5 times in a week through two ports at 8 x 8 cm field including right orbital region. Three years 7 months after radiation therapy he complained of disorientation, recent memory disturbance and slight left hemiparesis. On enhanced CT irregular ring enhanced mass lesion was seen in left temporal lobe inside the radiation field with extensive low density over temporal lobe on plain CT. MR imaging demonstrated that T 1-weighted spin echo images with a 50-msec repetition time (TR) and 22-msec echo time (TE) had irregular low signal intensity and extensive high signal intensity combined with partially low intensity in the central area on T2 weighted spin echo images with 2300 msec TR and 100 msec TR. There were not appeared vascular obstruction and stenosis on right carotid angiogram. He improved remarkably on clinical symptoms and CT by treating of dexamethasone and osmotic diuretics, but died of pneumonia.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗