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Biomedical subjects

K Moritake

Publications and source records attributed to K Moritake.

At least 37 records · Page 2Linked to original sources
PubMed1996

Intraoperative monitoring with pulse Doppler ultrasonography in transsphenoidal surgery: technique application.

We describe an intraoperative use of pulse Doppler ultrasonography in transsphenoidal surgery to prevent mechanical vascular injury, particularly to the intracavernous portion of the internal carotid artery. This system is integrated by connection to a video processor. The use of Doppler sonography provided real-time measurement of arterial or venous flow velocity and source of flow by both real-time sonograms and sound frequencies. With the use of a microprobe, 1 mm in diameter, vessels located within 7 mm from the tip of the probe could be easily, rapidly, and noninvasively detected, without disturbing operative field. Furthermore, both the size and the distance of a vessel could be measured by turning the dial of Doppler signal gain from initially waxing to waning Doppler sounds, because the acoustic sounds were adjusted to the axial flow of each vessel in 0.1-mm increments. Our intraoperative monitoring enhanced operative safety with technical simplicity and reliability.

Adenoma↗
PubMed1996

Validity of B-mode ultrasonographic findings in patients undergoing carotid endarterectomy in comparison with angiographic and clinicopathologic features.

BACKGROUND AND PURPOSE: Determining factors for performing carotid endarterectomy (CEA) are the severity of carotid stenosis and the presence of plaque ulcerations. Precise detection of these factors is important. The aim of this study was to assess the applicability of using B-mode ultrasonography for diagnosing carotid lesions in patients undergoing CEA. METHODS: B-mode examinations were performed on 64 Japanese patients (68 arteries) who subsequently underwent CEA. In each case, the appearance of plaque on B-mode was classified into one of two types: heterogeneous or homogeneous; plaque echogenicity was expressed as hypoechoic, isoechoic, or hyperechoic. Surface characteristics such as ulceration also were examined, and the degree of carotid artery stenosis was calculated. The B-mode findings were compared with angiographic and pathological features. RESULTS: B-mode accurately visualized macroscopic ulceration and surface irregularity in 93.8% of the lesions examined, which was superior to angiography. Fifty-four lesions (79.4%) were of the heterogeneous type and 14 lesions (20.6%) were of the homogeneous type on B-mode. Microscopically, 57.4% of the heterogeneous-type lesions demonstrated fibrous change. The frequency of calcification was higher in the heterogeneous lesions than in the homogeneous lesions. CONCLUSION: B-mode ultrasonography findings can provide information about macroscopic and microscopic characteristics of carotid lesions.

Adult↗
PubMed1996

[Therapeutic effectiveness of combined microsurgery and radiosurgery in a patient with a huge trigeminal neurinoma].

A case of right trigeminal neurinoma extending from the cavernous sinus to the cerebellopontine angle in a 48-year-old male is reported. The patient first noticed right facial numbness in June 1993. Six months later, he experienced headaches with occasional nausea, diplopia, ataxic gait, tinnitus and dysphagia and was referred to our department on January 21, 1994. Neurological examination on admission showed multiple cranial nerve palsy from the 4th to 11th nerve on the right, and the cerebellar sign on the right. Initial CT and MRI revealed a large mass lesion extending from the right cavernous sinus to the right cerebellopontine angle. On February 16, 1994, radical resection of the tumor, except the lesion invading the cavernous sinus, was performed via a combined retroauricular and preauricular transpetrosal transtentorial approach. The histological diagnosis was neurinoma. The patient's postoperative course was uneventful and there was good clinical improvement, although the right facial numbness and mild diplopia persisted. On April 6, 1994, radiosurgery was performed with a maximum dose of 28 Gy and a marginal dose to 14 Gy to the remaining cavernous sinus lesion. Two weeks after radiosurgery, the patient achieved a complete return to his daily routine. Two-year follow-up CT and MRI showed a small residual les on in the right cavernous sinus alone. There was no evidence of tumor growth. No new neurological deficits had developed, and the patient's the double vision had resolved. Thus, the patient has been able to maintain a satisfactory level of activities of daily living. We wound like to emphasize the clinical value of the strategy used to treat this patient which combined microsurgery with subsequent radiosurgery.

Cranial Nerve Neoplasms↗
PubMed1995

Effect of nicardipine on abnormal excitability of CA3 pyramidal cells in hippocampal slices of spontaneously epileptic rats.

The effects of nicardipine, a Ca2+ channel antagonist, on the abnormal excitability of hippocampal CA3 neurons in spontaneously epileptic rats (SER), a double mutant (zi/zi, tm/tm), were examined to elucidate whether or not the abnormality was due to that of Ca2+ channels. An intracellular recording study was performed using brain slice preparations of SER 12-15 weeks of age, when SER showed both tonic convulsions and absence-like seizures. Bath application of nicardipine (10 nM) completely inhibited the depolarizing shifts lasting for 60-120 ms and accompanying repetitive firings on mossy fiber stimulation in SER. However, this drug did not affect the single action potential induced by the mossy fiber stimulation in CA3 neurons of SER and normal Wistar rats. In the CA3 pyramidal neurons of SER, the Ca2+ spikes induced by the depolarizing pulse applied in the cell in the presence of tetrodotoxin and tetraethylammonium had a different configuration from that in normal Wistar rats. Nicardipine also inhibited the Ca2+ spikes in SER CA3 neurons at a concentration (1 nM) that had no effect on those in normal Wistar rats, while the Ca2+ spikes in Wistar rat CA3 neurons were inhibited by 10 nM nicardipine. These findings suggest that the abnormal excitability of CA3 pyramidal neurons in SER might be attributed to abnormalities of the Ca2+ channels, and that the Ca2+ channel antagonist may be effective as an antiepileptic drug.

Animals↗
PubMed1995

Study of aneurysmal subarachnoid hemorrhage in Izumo City, Japan.

BACKGROUND AND PURPOSE: Estimation of the actual incidence rate of subarachnoid hemorrhage and evaluation of the treatment require the inclusion of all patients in a defined geographic area. METHODS: During 1987 through 1992 in Izumo City, Japan, we estimated the incidence rate of subarachnoid hemorrhage by including dead-on-arrival patients and by further adding the results obtained after reviewing all death certificates registered in this city in the corresponding period. In addition, we compared the management and surgical outcomes in hospitalized patients from 1987 through 1992 with outcomes from 1980 through 1986. RESULTS: During 1987 through 1992, we diagnosed 123 patients as having subarachnoid hemorrhage. The crude and the age- and sex-adjusted incidence rates using the 1990 population statistics for Japan were 25 (95% confidence interval, 21 to 30) per 100,000/y and 23 (95% confidence interval, 19 to 28) per 100,000/y for all ages, respectively; these occurrences are the highest among those reported to date. Of these patients, 8% died before receiving medical attention, 27% in the first week, and 39% at 1 month. The survival curve for 2 years improved significantly from 1980-1986 to 1987-1992 in patients with admission grades 4 and 5 (P = .035) and in operated patients with preoperative grades 1 through 3 (P = .036). However, there was little improvement in the overall management results (P = .168), possibly because patients with high risk and/or old age were admitted and/or diagnosed more often in the latter period. CONCLUSIONS: The incidence rate of subarachnoid hemorrhage is much higher than that reported so far in the literature, and despite improvement of management and surgical therapy, the actual case-fatality rate is still high, mainly because of the high mortality rate directly associated with the primary bleeding.

Adult↗
PubMed1995

Primary malignant lymphoma of the central nervous system--report of four long-term survivors.

Four of 47 patients treated between 1977 and 1993 for histologically confirmed primary malignant lymphoma of the central nervous system (non-Hodgkin's type of B-cell origin) achieved long-term survival for more than 5 years with a good quality of life. Three have remained disease-free for 9-12.5 years. The fourth achieved complete remission for more than 5 years before death from tumor recurrence. All four patients were treated with a standard therapeutic regimen, consisting of radiotherapy (50-60 Gy local and 30-40 Gy whole brain irradiation) followed by four to six courses of chemotherapy with cyclophosphamide, vincristine, adriamycin, and prednisolone at 4- to 8-week intervals. No further treatment was performed after remission had been obtained. No specific predictors for long-term survival including sex, age, tumor location, multiplicity of lesions, histology, or treatment modality was identified. All four patients showed an immediate tumor response to radiation. We recommend chemotherapy at increasing intervals as part of the post-therapeutic management of long-term, disease-free patients.

Adult↗
PubMed1995

[Intratumoral pharmacokinetics following intraarterial administration of MCNU in patients with malignant gliomas].

This clinical study was undertaken to examine intratumoral (i.t.) pharmacokinetics after intraarterial (i.a.) administration of MCNU (80mg/m2) in 5 patients with glioblastoma (GB) and 2 with anaplastic astrocytoma (AA). After resection or stereotactic biopsy of the cystic lesion, an Ommaya reservoir was placed into the tumor cavity in all patients. The distribution of MCNU in blood was compatible with a two-compartment model, and the half life of the alpha-phase and beta-phase was 4.1 minutes and 160.4 minutes, respectively. MCNU was detected in the i.t. fluid in 5 cases, 4 of GB and 1 of AA. The concentration of i.t. MCNU gradually increased during the 5 to 30 minutes after i.a. injection to a level about 20.0% of its blood concentration. However, no MCNU was detected in patients showing partial response (3 of GB and 1 of AA) or no change (1 of GB) after the i.a. infusion of MCNU during maintenance chemotherapy. These results suggests that MCNU may transfer into the tumor tissues. Further investigation is warranted.

Adolescent↗
PubMed1995

[Effects of the nitric oxide donor SIN-1 on the membrane potential of mouse neuroblastoma-rat glioma hybrid cells].

The effect of the nitric oxide donor SIN-1 on the membrane potential of cultured mouse neuroblastoma-rat glioma hybrid NG108-15 cells was investigated using the whole cell patch method. It has been reported that neurite formation can be induced in NG108-15 cells by adding of dibutyryl cyclic AMP to the culture medium. Using this system we found that SIN-1 has a selective inhibitory effect on the membrane potential of the calcium current which is concentration-dependent in the 1 mu M-100 microM range. This effect was transient and reversible, the same as seen with the calcium channel blocker nilvadipine at concentrations of 10 microM to 10 microM. At higher concentrations, ranging from 500 microM to 1 mM, however, SIN-1 also caused prolonged inhibition of the membrane potential of the sodium current. However, this effect was also reversible. These findings suggest that SIN-1 has a reversible inhibitory action on the membrane potentials of neurons.

Animals↗
PubMed1995

[The efficacy of granisetron as a prophylactic anti-emetic agent used in conjunction with MCNU and VP16 chemotherapeutic regimens in the management of a pediatric case of hypothalamic anaplastic astrocytoma].

The management of a 12-year-old boy with hypothalamic anaplastic astrocytoma is reported herein. The pediatric patient underwent a subtotal removal of his brain tumor, and subsequently received multimodal treatment comprising radiotherapy (30.6 Gy to the whole brain and 50.4 Gy to the local lesion) and immunochemotherapy with MCNU (80 mg/m2, day 1), VP 16 (50 mg/day, days 2 to 6), and interferon-beta (3 x 10(6) units/day, initiating on day 2 for 4 weeks). The immunochemotherapy was given as of 4 weeks after radiotherapy. The administration of anti-cancer drugs caused severe nausea and vomiting, the intra-carotid infusion of MCNU being particularly emetogenic. The multi-modal treatment was then discontinued for a few weeks. A partial response was obtained, and the patient subsequently received 3 courses of maintenance therapy at six-month intervals using the same protocol as for the initial immunochemotherapy. During maintenance therapy, granisetron (40 micrograms/kg) was given intravenously 30 minutes before and one day after the injection of MCNU. Owing to the anti-emetic management of this patient, there were no complications throughout the chemotherapy. The patient has now survived for more than 3 years with a good quality of life, showing a Karnofsky performance score of 90.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

[Role of nitric oxide produced by activated macrophages in their cytocidal activity against glial tumor cells].

This study investigated the role of activated macrophages (M phi) in nitric oxide (NO) production and the tumoricidal effect of NO on glioma cells. Induced peritoneal M phi were prepared 6 days following the injection of thioglycollate broth into C3H/He N (H-2 kappa) mice. M phi were activated in vitro recombinant human interferon-gamma (IFN gamma) and lipopolysaccharide (LPS) into the culture medium of the elicited M phi. Two kinds of murine malignant glioma cell lines, RSV-M glioma (H-2 kappa) and VM-glioma (H-2b) were used as targets. P815 mastocytoma cells (H-2d) were used as a control target, since they are insensitive to tumor necrosis factor-alpha, but susceptible to NO derived from M phi. L-arginine-depleted medium was used to inhibit NO-mediated cytocidal activity against tumor cells. Cytotoxicity was assayed at various effector-to-target ratios using an admixture of M phi and 1.5 x 10(4) 125I-labeled target cells 48 hours following co-culture. NO was measured in culture medium using Griess reagent, and the concentration of NO was expressed as mu mol/ml NaNO2. Peritoneal M phi induced only 10% and 15% lysis of RSV-M glioma and VM glioma cells, respective, and LPS augmented this killing activity of M phi to a maximum of 1.2 to 1.4 fold in a dose-dependent manner with dosages from 1 to 50 ng/ml. LPS demonstrated a synergistic action on M phi-mediated cytotoxicity 4 hours following pretreatment with IFN gamma. Alternatively, low doses of IFN gamma alone had no enhancing effect on M phi tumoricidal activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

[Pharmacokinetics of intratumoral interferon-gamma activity following subcutaneous administration of recombinant interferon-gamma in a patient with metastatic brain tumor derived from renal cancer].

Pharmacokinetic studies of intratumoral interferon (IFN)-gamma activity were performed 1 week and 1 month after subcutaneous (s.c.) administration of recombinant IFN-gamma (specific activity = 1 x 10(7) units/mg protein) to a patient with metastatic brain tumor in the right occipital lobe derived from primary renal cancer. The patient, a 54-year-old man, underwent total removal of the lesion on April 10, 1991, with placement of an indwelling Ommaya Reservoir in the tumor cavity. The histological diagnosis was clear-cell carcinoma. His postoperative course was uneventful. Due to detection of a new ring-like enhancing mass in the right temporal lobe on serial CT examination on May 27, radiotherapy was discontinued immediately after delivery of a total dose of 30 Gy. Recombinant IFN-gamma was then administered s.c. at a dose of 3 x 10(6) units/day for 6 weeks, and induced a partial response. During IFN-gamma therapy, IFN-gamma activity in intratumoral fluid was measured 0 min, 30 min, 90 min and 6 hours after s.c. injection of IFN-gamma. The level of IFN activity was determined by an enzyme-linked immunosorbent assay. Intra-tumoral IFN-gamma activity gradually increased, and showed the highest of measured values at 6 hours after administration, while serum IFN activity decreased rapidly with a half-life of 30 min. The patient was discharged on July 30, but died from complications of aspiration pneumonia on September 2, 1991.

Adenocarcinoma, Clear Cell↗
PubMed1995

[Glial tumor cell proliferation and immune response in the brain].

The mechanism of glial tumor cell proliferation and the immune response to glioma cells in the brain were examined both in vitro and in vivo experimental systems, using mouse malignant glioma cell line, 203-glioma. A fura-2 fluorescence image showed marked rise in the intracellular calcium ion concentration in mechanically stimulated single cells. The increased calcium spread to adjacent cells, probably due to some stimulating factor released from cells. Dye microinjection revealed no gap junction between cells. Antagonists of voltage-dependent calcium channels did not act on the calcium response. These suggest that calcium signaling in the glioma cells may be mediated via a membrane receptor but not through a gap junction. Depletion of extracellular calcium ion and addition of intracellular calcium blocker demonstrated that calcium signaling in stimulated cells may be related to both an influx of extracellular calcium and a redistribution of intracellular calcium from internal stores, whereas calcium transmission to adjacent cells may involve calcium influx alone. The splenic cytotoxic T lymphocyte (CTL) activity in intracerebral tumor-bearing hosts increased with a peak 2 weeks after tumor cell inoculation, but rapidly decreased concurrently with increased intracranial pressure. The major histocompatibility complex, MHC, class I antigen expression on tumor cells grafted intracerebrally was found to enhance markedly, resulting in an increase in susceptibility to CTL. It was suggested that there may be a positive correlation between the cell surface MHC class I antigen expression and sensitivity to CTL in glioma cells.

Animals↗
PubMed1994

Cerebellar infarctions secondary to cranio-cervical anomalies: a case report.

We report a case of cerebellar infarctions which occurred in the territories of the bilateral posterior inferior cerebellar arteries. This case was complicated with cranio-cervical anomalies composed of assimilation of the atlas, atlanto-axial dislocation, and basilar impression. The 40-year-old male patient had no detectable risk factors predisposing to atherosclerotic arterial occlusion or cardiogenic embolism, and there were no angiographic findings of atherosclerosis. It was, therefore, postulated that the cerebellar infarctions were secondary to those cranio-cervical anomalies. The developing mechanism is discussed.

Adult↗
PubMed1994

Isolated adrenocorticotrophin deficiency associated with anti-pituitary antibodies, pituitary cyst, sphenoidal cyst and pineal tumor.

This paper reports a rare case of isolated ACTH deficiency associated with anti-pituitary antibodies, pituitary cyst, sphenoidal cyst and pineal tumor. A 68-year-old man consulted our clinic for general fatigue. Laboratory data showed low plasma adrenocorticotrophin (ACTH) and cortisol levels with blunted responses to insulin-induced hypoglycemia and corticotrophin releasing factor (CRF). Urinary 17-OHCS was low but responded to ACTH-Z administration. No other pituitary functions were impaired. Antibodies to the cytoplasm of rat pituitary and the surface of GH3 cells were detected in the serum. The magnetic resonance imaging (MRI) showed a high signal intensity mass in the anterior pituitary and in the sphenoidal sinus in both T1 and T2 weighted images as well as a low signal intensity mass in a T1 weighted image of the pineal region. Transsphenoidal surgery was performed to resect the mass in the sphenoid sinus and in the pituitary. Pathological studies showed a benign cyst in the sphenoid sinus, and fibrous degeneration and decreased basophils in the pituitary. No infiltrative mononuclear cells were detected in the pituitary. Immunohistochemical studies revealed a decrease in the number of ACTH-producing cells in the pituitary. The patient was well maintained by glucocorticoid replacement without any growth of a possibly benign pineal tumor.

Adrenocorticotropic Hormone↗
PubMed1994

Intratumoral administration of tumor necrosis factor-alpha for malignant gliomas--two case reports.

Two patients with histologically verified glioblastoma multiforme and anaplastic astrocytoma were treated with four courses of intratumoral administration of human natural tumor necrosis factor-alpha (TNF) (specific activity 2.0 x 10(6) Japan reference unit [JRU]/mg protein) at intervals of 3-5 months. Each consisted of eight to 10 serial injections, ranging from 5 x 10(3) to 10(4) JRU/injection, at intervals of 3-5 days. There was no simultaneous administration of steroids. Serial neurological examinations and neuroimaging studies with computed tomography and magnetic resonance imaging demonstrated partial responses ranging from 28 and 36 months in duration. No significant TNF-related brain edema, intracerebral bleeding, or neurotoxicity occurred. Local immunotherapy with TNF may be used safely to contribute to therapeutic efficacy.

Adult↗
PubMed1994

Intraoperative use of Doppler ultrasound and endoscopic monitoring in the stereotactic biopsy of malignant brain tumors. Technical note.

An intraoperative monitoring tool is described that prevents mechanical injury to intracerebral vessels during stereotactic surgery. The method, which combines pulse Doppler ultrasonography and fiberendoscopy, allowed stereotactic biopsy to be performed without serious intracerebral bleeding in 25 patients with hypervascular malignant brain tumors, 13 with glioblastoma multiforme, five with anaplastic astrocytoma, five with metastatic tumor, and two with malignant lymphoma. The ultrasound apparatus has a built-in fast-Fourier transformation system analyzer and an improved filtering system that provide real-time measurement of blood flow velocity. The source of flow (arterial or venous) could be identified by both real-time sonography and acoustic signal frequencies. It was possible to measure the size and distance of a vessel by adjusting the Doppler signal gain dial from initially waxing to waning sounds, because the acoustic signal was adjusted to the axial flow of each vessel in 0.1-mm steps. Each of three Doppler probes (1 mm, 2 mm, and 3 mm in diameter) fit through the outer cannula of the biopsy needle. Vessels located within 7 mm from the tip of these probes could be detected easily and rapidly, so the biopsy needle could be advanced safely to the desired target in 7-mm steps. If sonograms revealed blood flow, indicating the presence of larger vessels in the intended stereotactic trajectory, the angle of the needle was changed slightly to avoid vascular injury. Because the fiberendoscope was connected to a video processor, the vessel could be visualized at a higher magnification on the video display, unless there was active bleeding. This technically simple and reliable system enhances operative safety while maintaining accuracy.

Biopsy↗
PubMed1994

Analysis of intra- and intercellular calcium signaling in a mouse malignant glioma cell line.

Intra- and intercellular calcium signaling in glioma cells was examined by mechanical stimulation of a monolayer cell line of methylcholanthrene-induced mouse ependymoblastoma, 203-glioma, with a fine round-tip glass needle. A fura-2 fluorescence image of the glioma revealed a four- to eightfold increase in the cytosolic calcium ion concentration in directly stimulated signal cells. The increased calcium spread to surrounding cells at a speed of 20 microns/sec for a distance of up to 200 microns. Calcium was transmitted between adjacent cells and even in cells up to 200 microns distant from the initially stimulated cell. Microinjection of Lucifer yellow dye showed no gap junctional communication between cells. Depletion of extracellular calcium ion inhibited both cytosolic calcium elevation and propagation to neighboring cells by mechanical stimulus. An intracellular calcium blocker, TMB-8, eliminated the cytosolic calcium mobilization in a mechanically stimulated cell, but had no effect on calcium diffusion to surrounding cells. Nifedipine and verapamil, antagonists of voltage-dependent calcium channels, did not act on the mechanically induced calcium response. This suggests that some stimulating factor may trigger transmission of calcium, which may be ejected directly from single stimulated cells and mediated via a membrane receptor but not through a gap junction. The calcium signaling in a mechanically stimulated cell may be related to both an influx and a redistribution of intracellular calcium from internal stores, while calcium propagation to neighboring cells may involve calcium influx alone.

Animals↗