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Biomedical subjects

S Nishio

Publications and source records attributed to S Nishio.

At least 163 records · Page 9Linked to original sources
PubMed1995

Inhibition of restenosis by beraprost sodium (a prostaglandin I2 analogue) in the atherosclerotic rabbit artery after angioplasty.

We examined the effect of beraprost sodium (BPS), a stable prostaglandin I2 (PGI2) analogue, on restenosis after balloon angioplasty in the atherosclerotic artery in rabbits. Regional atherosclerosis was induced in the femoral artery of New Zealand white rabbits by balloon deendothelialization and 2% cholesterol diet. After establishment of atheroma in the femoral artery, angioplasty was performed. In all, 65 rabbits were assigned to the following six subcutaneous drug treatment groups: control group (n = 13, saline 0.25 ml/kg); BPS low-dose group (n = 11, BPS 50 micrograms/kg twice daily); BPS high-dose group (n = 12, BPS 100 micrograms/kg twice daily); 2-day BPS high-dose group (n = 11, BPS 100 micrograms/kg twice daily for 2 days after angioplasty); aspirin (ASA) group (n = 10, ASA 30 mg once daily); and BPS+ASA group (n = 8, BPS 50 micrograms/kg twice daily plus ASA 30 mg once daily). Administration of each drug was started 30 min before balloon angioplasty and was continued until 4 weeks thereafter, except in the 2-day BPS high-dose group. Re-examination 4 weeks after the angioplasty showed significant (p < 0.05) preservation of the luminal diameter in the BPS high-dose and 2-day BPS high-dose groups (1.30 +/- 0.15 and 1.25 +/- 0.09 mm, respectively) as compared with that in the control group (0.83 +/- 0.10 mm); however, the luminal diameter in the BPS low-dose, ASA, and BPS+ASA groups (0.94 +/- 0.18, 1.06 +/- 0.11, and 1.05 +/- 0.15 mm, respectively) was not significantly different from that in the control group.

Administration, Oral↗
PubMed1995

Beneficial effects of beraprost sodium, a stable prostacyclin analogue, in diabetic cardiomyopathy.

We examined whether beraprost sodium (beraprost), a stable prostacyclin analogue, prevented cardiomyopathy in diabetic rats in vivo. Diabetes was induced by a bolus injection of streptozotocin in rat-tail vein. Four weeks after the induction of diabetes, the animals were treated with beraprost (30 micrograms/kg/day, p.o.) for 4 weeks until they were used for the measurement of hemodynamics, electrocardiogram (ECG), and plasma creatine phosphokinase (CK) activity. Nontreated diabetic rats have lower mean blood pressure, heart rate, left ventricular systolic pressure, and peak positive dP/dt at basal levels compared to age-matched normal rats. All of these changes were not improved in beraprost-treated rats. The left ventricular end-diastolic pressure and ST/R ratio in the ECG were significantly increased in diabetic rats. These parameters were significantly improved by beraprost compared with nontreated diabetic rats. Additionally, beraprost significantly suppressed the elevation of plasma CK activity as compared with that in non-treated diabetic rats. Changes in peak positive dP/dt in response to isoproterenol were attenuated in nontreated diabetic rats as compared with age-matched normal rats and beraprost-treated diabetic rats. These results suggest that beraprost is capable of preventing diabetic cardiomyopathy without affecting hyperglycemic condition.

Administration, Oral↗
PubMed1995

Pharmacokinetic study of valproic acid sustained-release preparation in patients undergoing brain surgery.

Pharmacokinetics of valproic acid sustained-release preparation (VPA-SR) were studied in nine patients undergoing surgery for brain tumor. Total (t) and free (f) serum concentrations were analyzed in samples drawn during the day of brain surgery and compared with levels from a postoperative day. The area under the curve (AUCt) and clearance (CLt) of the total concentration did not differ on these occasions. In contrast, statistically significant differences were observed in AUCf and CLf between the two occasions; increased AUCf and decreased CLf were observed on the day of surgery. A significant relation was found between the average free fraction (AUCf/AUCt on operation day per AUCf/AUCt on postoperative day) and estimated blood loss during operation (r = 0.82; p < 0.001). In addition, a significant relation was found between simple free fraction and the intraoperative albumin level in serum (r = -0.68; p < 0.001). These findings indicate that the increased VPA free concentration is due to low serum albumin level secondary to blood loss and that there has been a decrease in intrinsic clearance during operation.

Adolescent↗
PubMed1995

Primary intracranial squamous cell carcinomas: report of two cases.

Two cases of primary intracranial squamous cell carcinomas are reported. The first patient is a 57-year-old man with an epidermoid carcinoma in the right cerebellopontine angle, having histological features that indicated malignant transformation in a benign epidermoid cyst. The second patient is a 42-year-old man in whom squamous cell carcinoma arose in a pre-existing middle fossa dermoid cyst 9 years after the initial surgical resection. The literature on primary intracranial squamous cell carcinomas is reviewed, and the clinical features and histological pathogenesis for the occurrence of this unique condition are discussed.

Adult↗
PubMed1995

Acquired Chiari I malformation and syringomyelia associated with bilateral chronic subdural hematoma. Case report.

The authors report a case of bilateral chronic subdural hematoma in a 25-year-old woman who had occipital and neck pain. Magnetic resonance imaging revealed progressive caudal descent of the cerebellar tonsils (acquired Chiari I malformation) and a large eccentric syrinx in the spinal cord from the C3-T7 levels. Spontaneous disappearance of the chronic subdural hematomas resulted in radiographic resolution of both lesions, as well as clinical improvement. Theories of syringomyelia formation, the relationship to acquired Chiari I malformation, and the implications of this case are discussed.

Adult↗
PubMed1995

[Clean intermittent catheterization in neurogenic bladder patients with vesicoureteral reflux].

BACKGROUND: For neurogenic bladder (NGB) patients with vesicoureteral reflux (VUR), renal deterioration constitutes a primary threat to survival. Although anti-reflux surgery for those patients was reported to be effective, the efficacy of clean intermittent catheterization (CIC) in such patients still remains to be clarified. METHODS: Sixteen neurogenic bladder patients with VUR were treated with CIC. Eight of them had spina bifida and 3 had radical hysterectomy for uterine cancer. Other 5 patients had spinal cord injury, spondyrocace, measles encephalopathy, and 2 unknown diseases, respectively. Hyperactive bladder was noted in 11 patients, whereas hypoactive bladder was noted in 3. Three patients were not evaluated. RESULTS: VUR was improved in only 3 patients (3 ureters), whose VUR grades were not more than III. Nine patients (13 ureters) had to have antireflux surgery. Although 3 of them needed bladder augmentation afterwards, the success rate of the antireflux surgery was 84.6%. CONCLUSION: We concluded that CIC alone was not effective to control VUR in neurogenic bladder patients. Nevertheless, CIC remained a good treatment option when VUR was managed surgically.

Adult↗
PubMed1995

[Approximation of uroflowmetrograms using micturition model].

One hundred and two uroflowmetric curves obtained from adult men were approximated to investigate the individual micturition quantitatively. We obtained a differential equation under the hypothesis that the factors concerned with micturition are the vesical pressure as the driving force and inertia of urine, friction resistance and elasticity of urethra as resistance. Using one of the solutions of this differential equation, we could approximate the uroflowmetric curves for normal and abnormal micturition. Furthermore, we could describe the calculated vesical pressure curve from the differential equation. There was a lag in the phase of the calculated vesical pressure curve against the uroflowmetric curve, which was considered to appear according to the resistance due to both inertia of urine and elasticity of urethra. The mean value of the difference of the calculated vesical pressure during micturition in normal cases was larger than that in abnormal cases. This suggests that it is necessary to maintain a high vesical pressure during micturition in abnormal cases, to maintain a small difference of the vesical pressure. In conclusion, we approximated the uroflowmetric curves, described the calculated vesical pressure curves and estimated them quantitatively.

Adult↗
PubMed1995

Comparison of magnetoencephalography, functional MRI, and motor evoked potentials in the localization of the sensory-motor cortex.

To clarify the topographical relationship between peri-Rolandic lesions and the central sulcus, we carried out presurgical functional mapping by using magnetoencephalography (MEG), functional magnetic resonance imaging (f-MRI), and motor evoked potentials (MEPs) on 5 patients. The sensory cortex was identified by somatosensory evoked magnetic fields using MEG (magnetic source imaging (MSI)). The motor area of the hand region was identified using f-MRI, during a hand squeezing task. In addition, transcranial magnetic stimulation localized the hand motor area on the scalp, which was mapped onto the MRI. In all cases, the sensory cortex was easily identified by MSI and the results of MSI correlated well with the findings obtained by the intraoperative recording of somatosensory evoked potentials. In contrast, the motor cortex could not be localized by f-MRI due to either the activated signal of the large cortical vein or the lack of any functional activation in the area of peri-lesional edema. MEPs were also unable to localize the entire motor strip. Therefore, at present, MSI is considered to be the most reliable method to localize peri-Rolandic lesions [corrected].

Adult↗
PubMed1994

Induction of Cu,Zn-superoxide dismutase after cortical contusion injury during hypothermia.

To determine the effect of hypothermia on superoxide injury after cerebral contusion, the induction of Cu,Zn-superoxide dismutase was examined 6 h after contusion in rats using Northern blotting. Cu,Zn-superoxide dismutase gene expression increased at the periphery of the contusion, which may indicate the severity of the superoxide stimulus. This increase was preserved after contusion under hypothermia, which may show that superoxide injury is still severe although brain edema is decreased.

Animals↗
PubMed1994

Malignant lymphoma of the scalp at the site of a previous blunt trauma: report of two cases.

We describe two cases with malignant lymphoma presented as scalp tumors. Both patients had slowly growing subcutaneous lymphoma masses in the scalp after head trauma. In the first case, the scalp lymphoma presented as a recurrent disease during complete remission of her systemic lymphoma after chemotherapy. In the second case, the tumor involved the scalp, subjacent skull, and intracranial space without systemic manifestation. These cases represent examples of a possible relationship between head trauma and the development of between head trauma and the development of tumors involving the brain and its coverings.

Aged↗
PubMed1994

Telescience testbed experiments for biomedical studies: fertilization potential recording of amphibian eggs using tele-manipulation under stereoscopic vision.

The telescience testbed experiments were carried out to test and investigate the tele-manipulation techniques in the intracellular potential recording of amphibian eggs. Implementation of telescience testbed was set up in the two separated laboratories of the Tsukuba Space center of NASDA, which were connected by tele-communication links. Manipulators respective for a microelectrode and a sample stage of microscope were moved by computers, of which command signals were transmitted from a computer in a remote control room. The computer in the control room was operated by an investigator (PI) who controlled the movement of each manipulator remotely. A stereoscopic vision of the microscope image were prepared by using a head mounted display (HMD) and were indispensable to the intracellular single cell recording. The fertilization potential of amphibian eggs was successfully obtained through the remote operating system.

Animals↗
PubMed1994

Choroidal fissure cyst in the temporal horn associated with complex partial seizure.

We describe two cases presenting with small cysts in the choroidal fissure of the temporal horn (choroidal fissure cyst). Both patients manifested solely complex partial seizure. On magnetic resonance imaging, the signal intensity of the cyst was identical to that of the cerebrospinal fluid, and the underlying hippocampus was compressed by the cyst. Since the cyst was thought to be of a neuroepithelial type, and therefore of benign nature, surgical intervention was avoided since satisfactory medical control of the seizures was obtained.

Adult↗
PubMed1994

Beraprost sodium protects occlusion/reperfusion injury in the dog by inhibition of neutrophil migration.

1. The effects of beraprost sodium (beraprost) on myocardial infarct size in an anesthetized open-chest canine model of regional myocardial ischemia and reperfusion were investigated. 2. Administration of beraprost (300 ng/kg/min, intravenously) to dogs 45 min after left circumflex coronary artery occlusion until 105 min after reperfusion resulted in a significant reduction in infarct size. 3. The values of control and beraprost treated infarct size expressed as a percentage of the total left ventricle were 15 +/- 3% and 4 +/- 2%, respectively. 4. Reperfusion arrhythmia, plasma creatine phosphokinase (CK) and lactate dehydrogenase (LDH) level were significantly suppressed by treatment with beraprost. 5. By histological examination, beraprost proved to reduce neutrophil migration in the ischemic myocardium after 5 h reperfusion. 6. Therefore, it is suggested that the cytoprotective effect of beraprost during myocardial ischemia and reperfusion may be the consequence of the inhibition of neutrophil migration.

Animals↗
PubMed1994

Microcystic meningioma: clinicopathological features of 6 cases.

The clinical and morphological features of 6 patients with unusual meningiomas with extensive microcystic formation are presented. There were 4 males and 2 females, ranging in age from 30 to 64 years. The clinical and neuro-imaging features of these tumours were identical with those of meningiomas in general. Morphological examinations disclosed that the tumour cells in 4 cases had many ultrastructural characteristics in common with the arachnoid cap cells, viz. prominent and complex interdigitation of the fine cytoplasmic processes, many desmosomes, and intracytoplasmic microfilaments. In contrast, the tumour cells of 2 cases had characteristic structures in common with trabecular arachnoid cells, viz. stellate in shape, a small number of intracytoplasmic filaments, relatively thick cytoplasmic processes, and occasional desmosomes. The tumour cells in these 2 cases were considered to recapitulate the subarachnoid structure and showed microcystic appearance. Although the histogenesis of microcysts in meningiomas is considered not to be uniform, the biological behaviour of these 6 tumours corresponded to those of meningiomas in general.

Adult↗
PubMed1994

Experimental analysis of brain surface elastance in cats.

Brain surface elastance, defined as the pressure needed to compress the cortex 3 mm, was measured using the ophthalmodynamometer in six cats using three burr holes (frontal, parietal, and occipital) on each side. An intracranial mass was then used to compress the right side for 3 hours, and cardiac arrest was induced after the mass was removed. Elastance was measured four times: before insertion of the mass, 10 and 70 minutes after removal of the mass, and 60 minutes after cardiac arrest. The results showed that: brain surface elastance does not change between sides, but varies among regions with the parietal region having the highest elastance; elastance increases after compression by an intracranial mass, but not after cardiac arrest; and stiff brain tends to restore poorly. Elastance is apparently increased by the formation of edema. Measuring brain elastance may be useful in predicting brain restoration subsequent to removal of mass lesions.

Animals↗
PubMed1994

[Clinical results of percutaneous pyeloplasty for ureteropelvic junction obstruction: 5 years follow-up].

We performed percutaneous endopyeloplasty on 20 patients between February, 1988 and July, 1993. Eighteen patients had primary and two had secondary ureteropelvic junction (UPJ) obstructions. There were 15 female and 5 male patients, whose ages ranged from 14 to 77, with an average of 43.6. The length of the follow-up after pyeloplasty ranged from 4 to 69 months with an average of 28.7 months. Among the 20 patients, there were 4 high insertion type cases, a bifid renal pelvis in one case and one case combined with a renal stone. Incisions were made with a hook-shaped cold knife and Ono's transpelvic extraureteral approach was used in most patients. Catheters were placed at the upper and the lower of renal pelvis in the patient with a bifid renal pelvis. In the case with a renal stone, pyeloplasty was successively performed after percutaneous nephrolithotomy in a single session. An endopyelotomy stent (14 Fr) was indwelled for 6 weeks in all patients except one. All patients had a low grade fever and abdominal pain for a few days after their operations, but there were no major complications. In nineteen patients (95%), the symptoms improved and their obstructive patterns disappeared or improved during follow-up. Complete ureteral stricture was found in one case at the removal of the stent and open pyeloplasty was performed. Percutaneous endopyeloplasty is a safe and useful technique, but further evaluation and/or better techniques are needed for avoiding recurrence of obstruction.

Adolescent↗