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S Nishio

Publications and source records attributed to S Nishio.

At least 91 records · Page 5Linked to original sources
PubMed1999

Distribution of brainstem somatosensory evoked potentials following upper and lower limb stimulation.

OBJECTIVE: Because somatosensory evoked potentials (SEP) to lower limb stimulation have not been recorded from the brainstem to the extent that upper limb SEPs have been studied, we compared brainstem recordings in response to both median nerve (MN) and posterior tibial nerve (PTN)stimulation. METHODS: SEPs were recorded directly from the dorsal surface of the brainstem in four patients with fourth ventricle tumors. RESULTS: Following MN stimulation, medullary SEPs were characterized by a major negativity (N1) preceded by a small positivity (P1) and followed by a large positivity (P2). In the pons, triphasic waves with predominant negativity were obtained. With PTN stimulation, similar medullary SEPs with a P1'-N1'-P2' configuration and pontine SEPs with a triphasic waveform were obtained. CONCLUSIONS: Since the distribution of PTN SEP was identical to that of MN SEP, PTN SEPs are thought to be generated by mechanisms similar to those for MN SEP. Thus, the P1' and N1' of medullary SEP would be generated by the dorsal column fibers that terminate in the nucleus, with P2' possibly arising postsynaptically in the nucleus. The triphasic PTN SEP from the pons reflects an axonal potential generated in the medial lemniscal pathway.

Adult↗
PubMed1999

Combination therapy with irinotecan and cisplatin as neoadjuvant chemotherapy in locally advanced cervical cancer.

To evaluate the response rate and toxicity of the combination of irinotecan (CPT-11) and cisplatin in a neoadjuvant setting, a phase II study was conducted regarding the regimen of this combination in patients with locally advanced cervical cancer. Eligibility included patients with previously untreated stage Ib2, IIb, or IIIb squamous cell carcinoma with good performance status. CPT-11 (60 mg m(-2)) was administered intravenously on days 1, 8 and 15, followed by cisplatin (60 mg m(-2)) given intravenously on day 1. Treatment was repeated every 4 weeks for a total of two or three cycles. Among 23 eligible patients (median age: 59 years), three showed complete response (13%), 15 showed partial response (65%), for an overall response rate of 78% (95% confidence interval 58-90%). Stable disease was observed in four cases (17%) and progressive disease in one (4%). The median time to failure and median survival time have not yet been reached. Of the 52 treatment cycles administered, diarrhoea and grade 3 or 4 neutropenia were observed in 10% and 75% respectively. There were no therapy-related deaths. The combination of CPT-11 with cisplatin is a promising regimen for neoadjuvant chemotherapy in locally advanced cervical cancer. The toxicities of this regimen are well tolerated.

Adult↗
PubMed1999

Immunohistochemical expression of trk receptor proteins in focal cortical dysplasia with intractable epilepsy.

Focal cortical dysplasia (FCD), which is often associated with intractable epilepsy, is a form of abnormal structure of the cerebral cortex caused by a disorder of normal neocortical development. In such cerebral lesions obtained from four patients (two male, two female; average age 32.3 years at operation), the immunohistochemical expression of Trk receptors, which interact with neurotrophins and result in both growth and maturational changes in neuronal cells, was investigated in relation to the possible histogenesis of these lesions. In all cases, a derangement of the cortical laminar structure, dysplastic cytomegalic neurones, and large round balloon cells were the characteristic histological features. Immunohistochemically, the TrkA expression was localized in large dysplastic cytomegalic neurones, and TrkB expression was observed in large dysplastic and relatively small neuronal cells within the affected cortex. Although the exact roles of neurotrophins and their receptors in the pathogenesis of FCD remain uncertain, its development might be governed by such neurotrophic influences, and thus possibly prevent the death of abnormal neuronal cells. In addition, Trk receptors in FCDs may also play a role in establishing in the intrinsic epileptogenicity of FCDs.

Adult↗
PubMed1999

Histologic evaluation of spermatic veins in patients with varicocele.

BACKGROUND: Information concerning varicocele is limited in spite of its clinical importance. This study intends to clarify anatomical features of varicocele. METHODS: Spermatic veins were obtained from varicocele patients at surgery. Areas of two distinct portions (extracellular matrix and smooth muscle) were measured by a micro computer imaging device image analysis system on histologic slides with Masson trichrome stain. In addition, we evaluated the shape and arrangement of the smooth muscle fibers by a scanning electron microscope (SEM). RESULTS: Masson trichrome stain revealed that grade of varicocele partly correlated with thickness of the wall and with amount of the smooth muscle fibers. In the patients with grade 3 varicocele, SEM examination showed marked hypertrophy of longitudinal smooth muscle fibers, which were discriminated clearly from the inner circular fibers. CONCLUSIONS: This study indicated that morphological changes occurred in the muscle layers of varicoceles in the worst grade of varicocele. These structural changes which result from abnormal venous blood circulation may cause development of varicocele, resulting in male infertility.

Adolescent↗
PubMed1999

Changes in urinary output during laparoscopic adrenalectomy.

OBJECTIVE: To better understand the physiological effects of pneumoperitoneum, by examining changes in urinary output during gaseous and gasless laparoscopic adrenalectomy. PATIENTS AND METHODS: Laparoscopic adrenalectomy was performed with gas in six patients and without in three. Urinary output was measured during insufflation and after desufflation. RESULTS: In all patients who received gas, the urinary output was significantly decreased during insufflation and significantly increased after desufflation. However, there were no changes in urinary output in patients who did not receive gas. CONCLUSION: For the safety of laparoscopic surgery it is important to recognise that oliguria occurs during pneumoperitoneum, although the changes in urinary output caused no complications in renal function.

Adrenalectomy↗
PubMed1999

Pituitary abscess secondary to isolated sphenoid sinusitis.

Intracranial complications from isolated sphenoid sinusitis are rare but nevertheless demonstrate both a high morbidity and mortality. We herein report a case of a pituitary abscess secondary to sphenoid sinusitis in a 12-year-old boy. This patient presented with an acute onset of moderate fever and headache, followed by progressive right ptosis. An emergency endoscopic endonasal sphenoidotomy with sinus drainage and postoperative antibiotic therapy resulted in a satisfactory recovery.

Brain Abscess↗
PubMed1999

Hypothermia-induced ischemic tolerance.

Delayed resistance to ischemic injury can be induced by a variety of conditioning stimuli. This phenomenon, known as delayed ischemic tolerance, is initiated over several hours or a day, and can persist for up to a week or more. The present paper describes recent experiments in which transient hypothermia was used as a conditioning stimulus to induce ischemic tolerance. A brief period of hypothermia administered 6 to 48 hours prior to focal ischemia reduces subsequent cerebral infarction. Hypothermia-induced ischemic tolerance is reversed by 7 days postconditioning, and is blocked by the protein synthesis inhibitor anisomycin. Electrophysiological studies utilizing in vitro brain slices demonstrate that hypoxic damage to synaptic responses is reduced in slices prepared from hypothermia-preconditioned animals. Taken together, these findings indicate that transient hypothermia induces tolerance in the brain parenchyma, and that increased expression of one or more gene products contributes to this phenomenon. Inasmuch as hypothermia is already an approved clinical procedure for intraischemic and postischemic therapy, it is possible that hypothermia could provide a clinically useful conditioning stimulus for limiting injury elicited by anticipated periods of ischemia.

Animals↗
PubMed1999

Human chorionic gonadotrophin in CSF, not serum, predicts outcome in germinoma.

OBJECTIVES: Some intracranial germinomas, which may contain syncytiotrophoblastic giant cells (STGCs), are associated with a mildly to moderately increased human chorionic gonadotropin (HCG) concentration in serum, and patients with such germinomas are thus treated more aggressively than those with "pure" germinoma. However, the patients with germinoma and detectable HCG in CSF but not in serum have been classified and treated similarly to those with "pure" germinomas. The outcome of these patients and the relevance of HCG in the CSF were analysed. METHODS: The outcomes of patients with germinoma and increased serum HCG concentration (n=7) were compared with those of patients having detectable HCG titre in the CSF but not in the serum (n=5). RESULTS: Both groups in our series received similar treatments and also showed similar recurrence rates. The 40% recurrence rate in the group with HCG only in CSF did not correspond to the rate typical for "pure" germinoma: these tumours would be expected to have a better outcome. An additional patient whose CSF HCG were raised without increased serum HCG at recurrence is presented. CONCLUSIONS: It is recommended that patients with an increased HCG concentration in CSF should be considered to have "HCG producing germinoma", and they should be treated and followed up accordingly.

Adolescent↗
PubMed1999

[Clinical experience of image-guided neurosurgery with a frameless navigation system (StealthStation)].

We have applied the frameless navigation system (StealthStation) to various neurosurgical procedures to examine its usefulness. The system consists of a UNIX based workstation that creates triplanar and 3-dimensional images; an infrared optical digitizer with camera array; a reference-light-emitting diode (LED) array (e.g., reference array); and pointer probe modified by the addition of LEDs. This system was used to assist in placing a minimal skin incision and craniotomy in 4 cases, to determine the tumor/brain interface in 2 cases, to target the subcortical lesion in one case, and to correlate bony structure with a skull base tumor in 3 cases. The combined use with magnetic source imaging of the somatosensory cortex allowed a fast orientation of eloquent areas in 2 cases with peri-Rolandic tumor. This system, thus, was proved to be a useful adjunct to open-tumor biopsy or resection.

Adult↗
PubMed1999

[Intracranial primitive neuroectodermal tumor in an infant: a case report].

A 2-month-old girl with a supratentorial primitive neuroectodermal tumor (PNET), which extended into the skull, is herein presented. The patient underwent total removal of the tumor and also received a course of postoperative chemotherapy. After a follow-up period of 12 months, the infant is alive without recurrence. Histologically, the tumor was composed of poorly differentiated neuroectodermal cells, and these neoplastic cells showed a mild immunohistochemical reaction for GFAP and synaptophysin, and a moderate reactivity for neuron specific enolase and vimentin. In addition, a moderate level of immunoreactivity for HBA71 antigen (p30/32M1C2), which is the product of the M1C2 gene and is found in peripheral PNETs but not in central PNETs, was noted in many neoplastic cells. Although this tumor was located intracranially, it may be classified as a peripheral PNET.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

[Surgical treatment for intractable epilepsy: update and future].

For successful surgical treatment of intractable epilepsy, identification of the epileptogenic area and functional cortex, by using the intracranial electrodes such as subdural and depth electrodes, is important. Since 1994, via chronic subdural electrodes recording, we performed anterior temporal lobectomy with hippocampectomy for 18 patients with temporal lobe epilepsy. For 10 patients with extratemporal lobe epilepsy, cortical resection of the epileptogenic cortex was performed. For the epileptogenic cortex overlapping with functional area, we added the multiple subpial transection. Favorable postoperative seizure outcome was obtained in most of the patients. Although non-invasive presurgical evaluation modalities such as MRI, video-EEG monitoring, MEG, and FDG-PET are useful in the diagnosis of epilepsy, it is impossible to localize precisely the exact epileptogenic zone and functional cortex.

Electrodes, Implanted↗
PubMed1999

[Usefulness of T2* weighted magnetic resonance image in the diagnosis of head injury on chronic stage].

T2* weighted gradient echo image has heightened diagnostic sensitivity to hemorrhage, which is attributed to magnetic susceptibility-induced static field inhomogeneities arising from paramagnetic blood breakdown products such as hemosiderin, which shorten T2*. We examined 4 cases of head injury in chronic stage by T2* weighted images and assessed the clinical application of this sequence for diagnosis of the intracranial lesion. All patients underwent CT scan on acute stage and long-term follow up was performed. In all cases, abnormally low signals in the brain and subarachnoid space were more conspicuous with the T2* weighted image than with any of the conventional sequences. In 2 cases with diffuse axonal injury, of which lesions were not detected on acute stage CT scan, hypointensity area was clearly demonstrated in the cerebral peduncle and corpus callosum on T2* weighted images. Selection of T2* weighted image into the routine MR examination of patients with chronic stage of the head injury is recommended.

Adult↗
PubMed1999

[Temporal lobe epilepsy associated with old intracerebral hemorrhage due to capillary telangiectasis in the temporal lobe: case report].

A case of 45-year-old female, who presented with temporal lobe epilepsy was reported. The patient was found to have old intracerebral hemorrhage due to capillary telangiectasis in the temporal lobe. On the intraoperative electrocorticography, frequent paroxysmal activities were recorded independently both on the medial and lateral aspects of the temporal lobe. Even after resection of the lateral temporal lobe, frequent paroxysmal discharges were noted on the hippocampus. Histologically, there are astrogliosis and hemosiderin deposits in the white matter around the telangiectasis and the old hematoma. It is postulated that the hippocampus gained secondary epileptogenicity.

Adult↗
PubMed1999

Analysis of urinary concentrations of calcium phosphate crystal-associated proteins: alpha2-HS-glycoprotein, prothrombin F1, and osteopontin.

It has been reported that prothrombin F1 and osteopontin (OPN) have strong inhibitory effects on calcium oxalate crystallization and are produced in stone-forming kidneys in animal models. It is important to evaluate urinary concentrations of these proteins for patients with renal stones and healthy control subjects. Urinary macromolecules were collected from nine healthy individuals, nine stone-formers, and five patients with primary hyperparathyroidism (HPT). Each 50-mg aliquot of urinary macromolecules was mixed with calcium phosphate solution, and calcium phosphate crystal-precipitated proteins (alpha2-HS-glycoprotein, prothrombin F1, and OPN) were obtained. The proteins were analyzed by anion-exchange chromatography. Furthermore, OPN levels in whole urine from 18 healthy individuals, 31 stone-formers, and two patients with HPT were measured using a new enzyme immunoassay system. The elution peaks for prothrombin and OPN were significantly smaller for the stone-formers and patients with HPT, compared with the healthy control subjects. Urinary concentrations of OPN assessed using the enzyme-linked immunosorbant assay were significantly lower for stone-formers. Lower urinary excretion of prothrombin F1 and OPN by stone-formers might be one of the reasons for stone formation.

Adult↗
PubMed1999

[Schizencephaly: clinical and MRI features].

We report the clinical and neuroimaging features of 4 cases with schizencephaly. Case 1 had bilateral schizencephaly with open-lip on the right and closed-lip on the left. Case 2 had unilateral schizencephaly with closed-lip on the left and subcortical heterotopia on the right. Case 3 had unilateral schizencephaly with closed-lip on the left. Case 4 had bilateral closed-lip schizencephaly. Although all cases except for Case 3 had bilateral lesions, neurodevelopmental outcome was generally good; Case 1 and 3 had mild hemiparesis. All patient have epilepsy which are well-controlled with antiepileptic drugs. Thus, the clinical presentation of schizencephaly, even if bilateral lesions, are quite variable.

Adolescent↗
PubMed1998

Primitive neuroectodermal tumors.

The primitive neuroectodermal tumors (PNETs) of Hart and Earle constitute an important fraction of pediatric brain tumors that are clinically characterized by their aggressive behavior. In 1983, Rorke expanded the term "PNET" to include all small cell embryonal neoplasms of neuroectodermal origin, regardless of the location of the tumor. More recently, Dehner also proposed the terms "central" and "peripheral" PNETs, and the provocative concept of "PNET" has now come to encompass a diverse group of tumors in both the central and peripheral nervous systems. The acronym "PNET" has thus become a confusing and controversial term in the diagnosis and classification of pediatric embryonal tumors. We reviewed ten papers concerning the various aspects of PNETs.

Journal Article↗