Biomedical subjects

K Kiya

Publications and source records attributed to K Kiya.

At least 55 records · Page 3Linked to original sources

PubMed1993

Malignant astrocytoma with extracranial metastases: a case report.

A 41-year-old man was referred to this hospital after being diagnosed as suffering from malignant astrocytoma. In spite of two operations and subsequent chemoradiation therapy, the patient died 20 months after the onset of disease. At autopsy, the authors found skin invasion of tumor at left temporal region, softening of the brain and subarachnoid hemorrhage at the base of the brain. Yellowish-white bulging lesions were found at the bottom of left lung, diaphragm and parietal pleura. Histologically, primary lesion showed features of anaplastic malignant astrocytoma. Subarachnoid dissemination was noted at the base of the brain and in the spinal canal. Invasion into the vessels were observed both at the primary site and at the base of the brain. Glial fibrillary acidic protein positive spindle-shaped tumor cells proliferation was seen in the metastatic lesions. This case was diagnosed as malignant astrocytoma with remote extracranial metastases.

Adult↗

PubMed1993

[Peduncular hallucination in brain stem cavernous angioma: a case report].

A case of brain stem cavernous angioma associated with peduncular hallucination is reported. A 68-year-old man was admitted with complaints of left sensory disturbance. On the evening of the first hospital day, he developed vividly formed hallucinations. The hallucinations were accompanied by sleep disturbance and agitation. At approximately 2:00 am, he began to feel as though he could see his daughter watching television in a room. At one point he saw vivid pictures. MRI revealed a round mass with a mixed signal intensity core surrounded by a low signal intensity rim in the right brain stem. On the 10th hospital day, there were no hallucinations. On October 12th suboccipital craniectomy was performed and cavernous angioma and the surrounding hematoma was partially removed. Soon after that the patient was discharged with improvement of both ocular movement and left-sided sensory disturbance.

Aged↗

PubMed1993

[Venous thrombosis after closed head injury: a report of two cases presenting as intracranial hypertension].

Although sinus thrombosis occurs owing to various causes, sinus thrombosis after closed head injury is rarely reported. The authors encountered 2 cases with sinus thrombosis in whom intracranial hypertension occurred after closed head injury. In case 1, left abducens and oculomotor palsy developed as a false localizing sign, together with symptoms of intracranial hypertension 10 days after head injury. Using angiography, we made a diagnosis of stenosis of the superior sagittal sinus. Since the symptoms were aggravated under conservative treatment, V-P shunt was performed, but impaired vision was not improved. In case 2, symptoms of intracranial hypertension occurred 10 days after head injury. We performed magnetic resonance angiography (MRA) and made a diagnosis of stenosis of the bilateral transverse sinuses. The symptoms improved under conservative treatment. The use of conventional angiography has been the most reliable for a diagnosis of sinus thrombosis, but MRA will become useful from now on. For diagnosis, it is important to suspect sinus thrombosis after closed head injury. Surgical decompression is required for patients in whom symptoms are aggravated under conservative treatment.

Child↗

PubMed1993

[Pharmacokinetics and antitumor activity of MX2, a new morpholino anthracycline in brain tumor intracerebral transplanted in rats].

Pharmacokinetics and antitumor activity of MX2.HCl (MX2), a new morpholino anthracycline, were investigated in rats transplanted 9L gliosarcoma cells in the brain. (1) Pharmacokinetics: AUC of MX2 in the brain tumors which received intracarotid and intravenous injection of 2mg/kg of MX2 were 117.50 and 55.94 micrograms.hr/g, respectively. AUC of the brain tissue was 1.38-3.90 micrograms.hr/g. (2) Antitumor activity: The inhibition of cell growth at the concentration of 0.1 micrograms/ml was 73.1% with MTT assay. The mean survival time in tumor-bearing rats after intracarotid and intravenous injection of 2mg/kg of MX2 prolonged significantly. Therefore, it seems that MX2 will become an efficacious drug for the treatment of malignant glioma.

Animals↗

PubMed1993

[Study on three patients with malignant glioma showing tumor reduction during maintenance therapy with MCNU].

Tumor regression occurred in three of 19 patients (15.8%) with malignant glioma during maintenance therapy using MCNU. In two patients, the tumor reduced 5 and 8 months after the initial treatment, respectively. In the remaining patient, though the maintenance therapy was interrupted for a while and consequently the tumor size increased, readministration of MCNU reduced the tumor size two months later. Therefore, since the antitumor activity of MCNU against malignant glioma seems to require a certain time depending on the case, it is recommended that MCNU be given as maintenance therapy for at least half a year.

Adult↗

PubMed1992

Effect of intracarotid infusion of etoposide with angiotensin II-induced hypertension on the blood-brain barrier and the brain tissue.

This study investigated the effects of the intracarotid infusion of etoposide in combination with angiotensin II (AT II)-induced hypertension on the blood-brain barrier (BBB) and brain tissue in rats. Eighty rats were divided into five groups: Group 1, intravenous infusion of AT II to increase arterial blood pressure; Group 2, intracarotid infusion of etoposide at 22.5 mg/m2 for 10 minutes; Group 3, intracarotid infusion of etoposide at 75.0 mg/m2 for 10 minutes; Group 4, intracarotid infusion of etoposide at 75.0 mg/m2 for 20 minutes; Group 5, intracarotid infusion of etoposide at 75.0 mg/m2 for 10 minutes with AT II-induced hypertension. Evans blue staining of the brain was used as a monitor of BBB disruption. Mean arterial blood pressure over the experimental period in Group 1 increased from 86.3 +/- 1.3 mmHg (mean +/- SEM) to 139.0 +/- 2.4 mmHg, and Group 5 from 85.9 +/- 1.8 mmHg to 137.3 +/- 2.4 mmHg. None of the animals in Group 1 and 2 showed any obvious neurological change, while all the animals in Group 3, 4 and 5 exhibited diminished activity as their sole neurological change throughout the course of the experiment. Slight evidence of BBB disruption was seen in only 25% of the animals in Group 1. Significant BBB disruption was found in the animals in Group 2, 3, 4 and 5. No histological change was observed in any animal in Group 1 and 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗

PubMed1992

Penetration of etoposide into human malignant brain tumors after intravenous and oral administration.

Penetration of etoposide into the cerebrospinal fluid, brain tumor, and brain tissue after intravenous administration was investigated in patients presenting with malignant brain tumors. A relatively low dose (55-65 mg/m2) was used to compare intravenous with oral administration. High-performance liquid chromatography with fluorescence detection was used to evaluate drug levels. Plasma and cerebrospinal fluid levels of etoposide after oral administration (50-150 mg/day) were also studied so as to determine the adequate oral dose for the treatment of malignant brain tumors. The peak plasma concentration after intravenous administration ranged from 7.01 to 10.47 micrograms/ml, varying in proportion to the injected dose, whereas that after oral administration was lower, namely, 1.44-4.99 micrograms/ml, and was unstable when the oral dose was 150 mg daily. The peak cerebrospinal fluid level following either intravenous or oral administration was much lower than the plasma concentration and was influenced by the peak plasma level and the sampling site. The etoposide concentration in cerebrospinal fluid taken from the subarachnoid space and ventricle of patients displaying no tumor invasion and of those presenting with meningeal carcinomatosis and in cerebrospinal fluid taken from the dead space after tumor resection was 0.7% +/- 0.5%, 3.4% +/- 1.0%, and 7.2% +/- 8.5%, respectively, of the plasma concentration. Serial oral administration did not result in the accumulation of etoposide in cerebrospinal fluid. The tumor concentration (1.04-4.80 micrograms/g) was 14.0% +/- 2.9% of the plasma level after intravenous administration, was related to the injected dose, and was approximately twice the concentration detected in the brain tissue. Therefore, a relatively low dose of etoposide injected intravenously penetrates the brain tumor at an efficacious concentration. Our results indicate than an oral dose of 100 mg etoposide be given for malignant brain tumors, as limited penetration of the drug into the intracranial region was observed.

Administration, Oral↗

PubMed1992

Ganglioglioma of the optic pathway. A case report.

A case of ganglioglioma of the optic pathway associated with congenital exophthalmos and strabismus is presented. Since the tumor extended from the right optic nerve to the right geniculate body, it was diagnosed as an optic glioma before operation. However, optic nerve biopsy showed that the lesion was a ganglioglioma. Although a literature review yielded two previous cases of ganglioglioma of the optic pathway, this is the first case in which the tumor involved the whole optic pathway.

Adolescent↗

PubMed1992

Intracranial germ-cell tumor with synchronous lesions in the pineal and suprasellar regions: report of six cases and review of the literature.

The features of intracranial germ-cell tumor with synchronous lesions in the pineal and suprasellar regions (GCTSPS) in six patients were investigated. GCTSPS accounted for 12.8% of all germ-cell tumors (GCT) in our brain tumor study group. In all cases, the initial symptoms were attributable to the suprasellar lesion, and symptoms due to the pineal GCT developed only after admission. Five of the six cases were histologically diagnosed as germinoma. In all cases, tumors of both regions disappeared after irradiation, resulting in no recurrence for an average of 55.3 months. Our experience and reports in the literature suggest that GCTSPS is highly sensitive to radiation in most cases, although some reports indicated that recurrence is frequent after radiation therapy alone. It is suggested that histological diagnosis in one of the GCTSPS lesions is undertaken to make a plan for the following treatment.

Adolescent↗

PubMed1992

Intracranial metastasis from a spinal cord primitive neuroectodermal tumor: case report.

A patient with intracranial seeding from a spinal cord primitive neuroectodermal tumor with ependymal differentiation is presented. The first and second stages of intracranial dissemination were well controlled by a combination of irradiation and chemotherapy. The authors review previously published cases and discuss the possible mechanism of seeding from the spinal cord to the intracranial region.

Adolescent↗

PubMed1992

[Pineocytomas; clinicopathological evaluation of 4 cases].

Clinicopathological evaluation of pineocytoma was performed in 4 patients. The subjects, 2 males and 2 females, ranged in age from 17 to 40. All the patients were clinically found to have the symptom of increased intracranial pressure on a monthly basis, but none of them were found to have dorsal midbrain dysfunction symptoms such as Parinaud's sign or Argyll Robertson pupil. Diagnostic imaging produced heterogeneous pictures indicating calcifications and cyst in 2 patients and homogeneous pictures of the tumor parenchyma in the other 2 patients. Histologically, the former cases were found to have many pineal-sand-like calcifications. Median sagittal MR images demonstrated expansive growth of pineocytoma. Quadrigeminal plates which kept their shapes were observed in 2 patients. Craniotomy was performed in all cases, removing the tumor totally in 2 patients. Radiation therapy was given to 3 patients, resulting in complete remission, but radiosensitivity varied according to cases. During the follow-up period of 12 to 42 months, one patient died of peritonitis caused by shunt infection. No recurrence of the tumor was seen in any of the patients. The incidence of pineocytoma was very low. Further evaluation of the tumor involving many cases is advisable.

Adolescent↗

PubMed1992

A case of scalp cavernous hemangioma simulating sinus pericranii.

The authors report a case of cavernous hemangioma in the occipital region, which resembled sinus pericranii, protruded in the recumbent posture. A 28-year-old male was admitted with a chief complaint of an occipital fluctuating mass, 5cm in diameter, accompanied by slight pain. The skull X-P was normal. A direct puncture revealed that the lesion was a blood cyst. A cystogram by percutaneous needle puncture revealed paramedian blood pooling with some draining veins but did not show any transcranial communicating vessels. A T2 weighted MR image demonstrated a well demarcated high intensity lesion just beneath the corium. The subtotally removed specimen turned out to be a cavernous hemangioma. We discerned a conceptual confusion of pseudosinus pericranii with scalp cavernous hemangioma, based on the literature review. And we propose that scalp cavernous hemangioma, even if it changes its size according to posture, should not be simply designated as sinus pericranii.

Adult↗

PubMed1991

Glutathione and cellular response of ACNU-resistant rat glioma sublines to drugs and radiation.

Three ACNU-resistant sublines (R1, R3 and R12) from rat glioma 9L cells showed cross-resistance to vinblastine, adriamycin, and VP-16. Among these, the R3 subline also acquired radioresistance under aerobic conditions. Total glutathione levels in these sublines were elevated 2- to 3-fold. Treatment of the cells with BSO, a specific inhibitor of GSH synthesis, resulted in decreased intracellular total glutathione levels in all 4 cell lines to about 10% of control levels. However, sensitivity to radiation or to chemicals did not change accordingly. Treatment of 9L cells with OTZ, a precursor of cysteine, resulted in a rise in intracellular GSH levels but it did not correlate with sensitivity to X-ray or to ACNU. These results suggest that, in terms of cellular sensitivity to radiation or ACNU, total glutathione level alone cannot serve as a predictive indicator.

Animals↗

PubMed1991

Outcome of primary central nervous system lymphoma--a study of 32 patients.

The outcomes in 32 cases of histologically diagnosed primary central nervous system lymphoma were investigated. The 1-, 2-, and 5-year survival rates were 54, 36, and 8%, respectively. Good outcome was indicated by extensive surgical removal with 50-Gy irradiation and lower ages. 61% of patients receiving radiation therapy suffered recurrence within 1 year. The incidence of multiple lesions increased at recurrence. These lesions were almost all remote from the initial site in the brain, occurring more frequently in the central part of the supratentorial regions near the ventricle. Multiple lesions recurred more rapidly than single lesions. Longer survival times were indicated by a long tumor-free period after initial treatment. Extensive surgical removal results in long survival times for patients with a localized single tumor in the early stage. Radiochemotherapy should be given as part of the initial treatment.

Adolescent↗

PubMed1991

Intraventricular hemangiopericytoma--case report.

A very rare large intraventricular hemangiopericytoma occurred in a 41-year-old male with a 2-month history of headache and paresthesia of the right shoulder and arm. The tumor was partially removed, followed by 50 Gy local Linac irradiation given over 6 weeks. Four months later the residual tumor demonstrated a marked decrease in size and vascularity. The residual tumor was totally removed with less operative bleeding than at the initial operation. This is the first reported case of hemangiopericytoma located in the trigone of the lateral ventricle.

Adult↗

PubMed1991

[Establishment of ACNU-resistant rat gliosarcoma cell lines and their characteristics].

One of the most serious problems in cancer chemotherapy is the acquired drug resistance of tumor cells. In order to investigate the mechanism of acquired resistance to 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU), nine resistant cells were isolated from rat gliosarcoma 9L cells and characterized. ACNU-resistant cells were easily isolated after a single treatment even with low-dose ACNU (5 micrograms/ml). However, in spite of repeatedly high-pressure dose of ACNU, more than 30 fold increase to parental 9L cell resistance was not achieved. At this time, further increase in selection pressure resulted in cell death. The resistant ratios of these resistant cells were stable in the absence of ACNU for more than 1 year. Luria and Delbrück's fluctuation test indicated that the appearance of ACNU-resistant cells occurred spontaneously at a rate of (4.40-8.02) x 10(-7)/cell/generation. In karyotypic analysis, the mode was higher in the resistant cells than in 9L cells, but a homogeneously staining region or double minute chromosome, which was considered to be a result of gene amplification, was not observed. In growth kinetics, all the resistant cells except R1 and R12 cells had higher saturation density and plating efficacy than parental 9L cells. These findings seemed to be due to cellular modification associated with ACNU resistance.

Animals↗

PubMed1991

Cross-resistance patterns in ACNU-resistant glioma sublines in culture.

Three ACNU-resistant clones (R1, R3, and R12) were isolated from 9L rat glioma cells under selection pressure of ACNU in vitro. The authors have investigated the mechanisms of resistance and characteristics of these clones at the cellular level by studying cross-resistance patterns to chemical and physical agents. Although these resistant sublines showed complete cross-resistance to methyl-chloroethylnitrosourea (MCNU), no cross-resistance was observed for other alkylating agents, while each of the resistant sublines showed partial cross-resistance to structurally dissimilar toxic agents (vinblastine, Adriamycin, and VP-16). No difference in ACNU uptake was observed between 9L and R3 cells, and resistance patterns among alkylating agents suggested that the mechanism of ACNU resistance was specific to bifunctional nitrosoureas. Based on a transport study, this multidrug resistance could be explained by reduced intracellular uptake of these drugs, but there seemed little possibility that membrane P-glycoprotein, which usually is observed in typical multidrug-resistant cells, was expressed in these ACNU-resistant cells because enhanced drug efflux was not found in ACNU-resistant sublines. Significant collateral sensitivity to L-asparaginase indicated that ACNU might disturb the asparagine synthetic pathways by its mutagenic action. The increased level of total glutathione in the resistant sublines may be one mechanism of radiation or ACNU resistance.

Animals↗

PubMed1991

Hypersensitivity of rat glioma sublines with acquired ACNU resistance to L-asparaginase.

Cell lines resistant to 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3- (2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) show a high degree of collateral sensitivity to L-asparaginase. The mechanism for this phenomenon was investigated by comparing the nutritional requirements and asparagine synthetase activity of the resistant sublines to those of parent cells. Nine ACNU-resistant sublines were isolated from rat glioma 9L cells after incubation with various concentrations of ACNU in Ham's F-12 medium. The 9L cells grew independently of asparagine, developing well in asparagine-deficient Dulbecco's modified Eagle's medium. In contrast, the growth rates of all nine ACNU-resistant sublines decreased under the same conditions and required the addition of 10(-4) M asparagine for maximum growth. Asparagine synthetase activity in the ACNU-resistant cells was much lower than in the 9L cells, suggesting that the requirement for asparagine in the resistant sublines was due to reduced activity of this enzyme. A growth-inhibition assay showed that the ACNU-resistant sublines were more sensitive to L-asparaginase than 9L cells by up to 2 x 10(5)-fold. These results suggest that L-asparaginase therapy has the potential to become a new approach for treating acquired ACNU resistance.

Animals↗