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Biomedical subjects

K Kitamura

Publications and source records attributed to K Kitamura.

At least 1,081 records · Page 60Linked to original sources
PubMed1986

Effects of ACNU and radiotherapy on malignant glioma.

A randomized clinical study of irradiation and irradiation combined with ACNU in the treatment of malignant gliomas was performed in order to determine if there was an enhancing therapeutic effect of ACNU given in addition to radiotherapy. An effect was defined as a reduction in tumor size, changes in neurological signs and performance status within 1 month after the completion of radiotherapy, or statistically improved survival times. Seventy-seven patients from 14 neurosurgical clinics were included in this validated study group. Radiotherapy with a total dose of 5000 to 6000 rads, given in 25 to 30 subdoses, was applied to the whole brain and to a generous field surrounding the tumor. Patients who were assigned to receive chemotherapy were given ACNU intravenously once or twice during radiotherapy at a dose of 100 mg/sq m of body surface area. The response rate (more than 50% reduction of the tumor size) was 13.5% in the group treated by radiotherapy alone and 47.5% in the group with radiotherapy and ACNU. The hematological toxicity was more severe in the group treated with radiotherapy and ACNU. Other toxicity was mild and acceptable. The survival rates of patients with astrocytoma grade III and glioblastoma multiforme at 36 months after the surgery were 48.9% and 0% for radiotherapy alone and 59.0% and 16.3% for radiotherapy plus ACNU, respectively. The differences between the survival curves were not significant at the p = 0.05 level. This study has demonstrated that, although the use of ACNU during radiotherapy suppressed malignant gliomas more than radiotherapy alone, the survival time was not extended significantly. It is necessary to continue to search for an effective chemotherapeutic regimen to prolong survival of patients with malignant gliomas.

Adolescent↗
PubMed1986

The stabilization of vascular smooth muscle by procaine.

Procaine acts on the cell membrane as a depolarizing agent. It inhibits K-conductance; as a consequence, the membrane is depolarized and the spike potential is readily generated by outward current pulses. This inhibition of the K-conductance of membrane induced by procaine is discussed in relation to the K channel classified by the patch clamp procedure. The authors' observations indicate that procaine acts as a stimulant rather than as a stabilizer of the membrane. Furthermore, procaine inhibits the release of Ca from the store site, with no effect on the contractile protein. This local anaesthetic agent acts not only on the surface membrane but also on the internal membrane, the sarcoplasmic reticulum. Procaine reduces mechanical activity and stabilization of vascular smooth muscles occurs.

Animals↗
PubMed1986

[Clinical studies of cefoperazone in neurosurgery].

A multicenter trial consisting of 164 institutions through out Japan, has been conducted to study the transfer of cefoperazone (CPZ) into the cerebrospinal fluid (CSF), and the clinical effectiveness of CPZ as a therapeutic or prophylactic agent in neurosurgery. The levels of CPZ in serum and CSF were determined in 96 patients. After initial dose of 2 g CPZ (intravenous drip infusion for 30 minutes), the serum level of CPZ after 1 hour was 124.5 +/- 6.6 micrograms/ml (Mean +/- S.E.), and even after 6 hours, it maintained as high as 47.8 +/- 16.6 micrograms/ml. The peak CPZ levels in CSF in patients with normal or minimal impairment in blood-CSF-barrier (BCB) (group I) and in those of localized impairment in BCB (group II) were 1.0 +/- 0.5 micrograms/ml at 2 hours and 3.0 +/- 1.8 micrograms/ml at 3 hours, respectively. The highest CSF level was seen in patients with meningitis (group III) and showed 5.0 +/- 2.4 micrograms/ml at 6 hours. After multiple dose of 2 g CPZ (intravenous drip infusion for 30 minutes), the serum kinetics of CPZ were not significantly different from those obtained after initial dose. However, the CPZ levels in CSF were higher than those observed after initial dose in all 3 groups and were higher than MIC75 against relevant pathogens for meningitis such as Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus. Moreover, in group III peak level of CPZ in CSF exceeded the MIC75 against Pseudomonas aeruginosa which is also frequently isolated from patients with meningitis in neurosurgery. As a therapeutic agent CPZ administered as sole agent was effective in 42 out of 55 cases (76.4%) in meningitis, in 78 out of 116 cases (67.2%) in pneumonia and in 36 out of 47 cases (76.6%) in urinary tract infection (UTI). Its efficacy rate against all infections treated was 72.2% (184/255). Regarding CPZ's prophylactic use, 39 out of 514 cases (7.6%) were judged as having or possibly having infections as follows; meningitis (13/514, 2.5%), pneumonia (15/514, 2.9%), UTI (2/514, 0.4%). In prophylactic use of CPZ, the incidence rates of postoperative meningitis and other central nervous system (CNS) infection following ventricular drainage and supratentorial craniotomy for aneurysm were higher than those observed in other types of operation, 12.0% (3/25) and 6.2% (8/130), respectively. Also, regarding prophylactic use of CPZ, the organisms isolated by culture from 13 cases of postoperative CNS infections included 2 strains of Staphylococcus sp., 1 strain of Serratia sp. and 3 strains of other Gram-negative bacteria (GNB).(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1986

Correlation between MR signal intensity and histologic findings in neurinomas and meningiomas of the brain.

The signal intensity of magnetic resonance imaging (MRI) was compared with the histologic findings in 20 cases of neurinoma and 18 cases of meningioma. The apparatus was a Hitachi G-10 unit (0.15 T). The pulse sequences were SR (500/32), SE (1200/60), IR (1400/400). The intensity of tumor signal, as compared with that of normal white matter signal, was divided into 9 grades. In neurinomas, the signal intensity appeared markedly low with IR and markedly high with SE sequence in the Antoni B type, while it was slightly low with IR and minimally to markedly high with SE sequence in the Antoni A type, and intermediate between Antoni A type and B type in the mixed type. In meningiomas, it appeared moderately to slightly low with IR and slightly to moderately high with SE sequence in the meningotheliomatous type, minimally low with IR and minimally to slightly high with SE sequence in the fibrous type, and intermediate as compared with the above two in the transitional type. The angiomatous type was characterized by a low intensity on SR and IR images and an iso to high intensity on SE images, while the psammomatous type showed a low intensity with all of the sequences used. We clarified that the signal intensity on MRI varied among different histologic types of neurinoma or meningioma, and correlated differences in the intensity of signals on MRI to that of histologic characteristics, such as size and shape of cells, intercellular material, intracellular biologic polymers, area of membrane surface, blood flow and calcified matter.

Adult↗
PubMed1986

[Clinicopathological study of supratentorial tumors with multipotential differentiation in childhood. Primitive neuroectodermal tumor].

Three cases of supratentorial tumor in childhood were studied clinico-pathologically in an attempt to clarify its histological character. Case 1: A 3-year-old boy. Carotid angiogram revealed avascular lesion in the left parietal lobe. Twice operations and radiotherapy were performed. Ten months after the second operation, he died. Surgical specimen at the first operation was composed mainly of round tumor cells. The tumor tissue contained many collagen fibers. At the periphery of this tissue, medulloblastomatous areas consisting of closely aggregated hyperchromatic small round cells were found. There were perivascular rosettes and Homer Wright rosettes. In part, tubular and papillary arrangement of cells was also present. Astrocytomatous and oligodendrogliomatous structures were also present. Surgical specimens at the second operation showed the predominance of sarcomatous areas consisting of spindle-shaped cells with abundant argyrophilic fibers. Case 2: A 10-year-old girl. CT scan revealed a heterogeneous enhanced mass with a cyst and calcification in the right parietal lobe. Operation and radiotherapy were performed. Twelve months after operation, she is still alive. Most of the surgical specimens showed sarcomatous structure with abundant argyrophilic fibers. In these tissues, there were medulloblastomatous and ependymomatous features. Papillary arrangement of cells was also present. In part, there was oligodendrogliomatous structure. Case 3: A 2-year-old girl. CT scan revealed a heterogeneous enhanced mass in the right frontal lobe. The tumor tissue was composed of an aggregation of undifferentiated small round cells with Homer Wright rosettes.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain Neoplasms↗
PubMed1986

[Clinicopathological study on malignant glioma--with special reference to GFAP].

In surgical specimens of 91 cases of malignant glial tumor, the correlation between the clinical malignancy of the tumors and the presence of GFA protein in the surgical specimen was examined. In anaplastic astrocytomas, 20 of 27 cases revealed positive staining of GFAP. In the cases of glioblastoma multiforme 27 of 35 cases showed GFAP positive staining. On the other hand, in medulloblastomas, all 29 cases were negative. In anaplastic astrocytomas and glioblastoma multiforms, the difference between the survival curves of GFAP positive groups and negative groups were examined. Between two groups, there was no statistical differences. In this study, the presence of GFAP was not proportional to the degree of tumor differentiation, and the GFAP staining of the tumor tissue was not a valuable examination showing the prognosis of the patient.

Adult↗
PubMed1986

[Treatment of malignant brain tumors with slowly releasing anticancer drug-polymer composites].

The purpose of this study is to present the methodology and results of a clinical trial of local chemotherapy of malignant brain tumors based on slowly-releasing anticancer drug-polymer composites. The slowly releasing drugs were prepared by combining and mutually dispersing anticancer agents with glassified monomers containing 10% polymetacrylic methyl acid and then this compound was frozen at -78 degrees C and exposed to 1 X 10(6) rad of gamma rays from cobalt 60. Thus we prepared a compound of polymers and anticancer agents. We used needle-shaped capsules of this compound. These capsules release the drug very slowly over 40 days. We administered locally to the malignant brain tumors with either slowly releasing mitomycin, slowly releasing adriamycin, slowly releasing ACNU or slowly releasing 5 Fu drugs. The following techniques were employed in implantation these capsules. Implantation into the remaining tumor wall at the time of excision. Implantation into the tumor by CT-guided stereotactic method. We implanted these drugs into tumor of 55 cases, thereafter we conducted both radiation and chemotherapy with ACNU in most patients. This method has the following advantages: It is possible to be employed to different types of anticancer agents. Both dosage and releasing time can be adjusted. It is possible to administer these capsules postoperatively by the stereotactic method. The clinical study consists of 55 patients, 20 cases of anaplastic astrocytoma, 23 cases of glioblastoma multiforme, 5 cases of oligodendroglioma, 3 cases of medulloblastoma and 4 cases of others. Survival rate estimated by Kaplan-Meier method was 47% in glioblastoma at 12 months and 91% in anaplastic astrocytoma at 18 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Agents↗
PubMed1986

Forme fruste of von Recklinghausen's disease: unilateral association of an orbital neurofibroma, a trigeminal neurinoma, and an acoustic neurinoma. Case Report.

A patient who presented with a tumor of the left ambient cistern, a left cerebellopontine angle tumor, and a left orbital tumor causing left hearing loss and left exophthalmos without café au lait spots or cutaneous neurofibromas is described. There was no family history of von Recklinghausen's disease. A cerebellopontine angle tumor removed by a suboccipital craniectomy was an acoustic neurinoma. An ambient cistern tumor was approached through a subtemporal route. A tumor arising from the trigeminal nerve was also a neurinoma. An orbital neurofibroma was excised by a frontal craniotomy with removal of the orbital roof. This rare unilateral association of neurinomas and a neurofibroma on the left side was thought to be a forme fruste of von Recklinghausen's disease, and it could be considered a presentation of a mosaic of von Recklinghausen's disease.

Adult↗