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Biomedical subjects

A Zama

Publications and source records attributed to A Zama.

34 records · Page 2Linked to original sources
PubMed1994

[A juvenile case of radiation-induced meningioma two years after radiation for craniopharyngioma].

The patient was a 7-year-old boy who received radiation therapy of 50 Gy after total gross removal of a craniopharyngioma. After two years a follow up CT scan showed a new enhanced lesion in the right temporal tip within the previous irradiation field. Total removal of the tumor was performed and its histological examination showed it to be an atypical meningioma. This atypical meningioma satisfied Cahan's criteria. So we diagnosed this atypical meningioma as radiation-induced meningioma. Immunohistochemically this meningioma stained for Vimentin. An electron-microscopical examination showed neither desmosome nor interdigitation. The score of Ki-67 and BrdU-L. I. was very small. Compared with previously reported juvenile radiation-induced meningioma, the latency was very short. The patient received growth hormone (GH) replacement therapy. We suspected relation between GH replacement therapy and short latency. He was discharged without any new neurological deficits and we haven't detected tumor recurrence for two years.

Child↗
PubMed1993

Delayed brain hemorrhage associated with prophylactic whole brain irradiation for pediatric malignant brain tumor: a case report.

Intraparenchymal hemorrhage in the left frontal lobe suddenly occurred in a 7-year-old girl who had undergone partial removal of an undifferentiated brain stem glioma and received craniospinal (30 Gy) and posterior fossa booster (20 Gy) irradiation at the age of 20 months. The brain hemorrhage was thought to be delayed irradiation effect. Follow-up neuro-imaging at age 9 years showed two more small occult chronic and subacute hemorrhages in the brain. The possibility of repeated hemorrhage as a delayed reaction to brain irradiation is emphasized.

Brain Neoplasms↗
PubMed1993

Small gliomas: clinicopathological study.

The clinicopathological characteristics of small gliomas were investigated in nine patients with gliomas less than 2 cm in diameter. The tumor histology and proliferative activity were also examined. Three tumors occurred in the white matter and six at the corticomedullary junction. Histological diagnosis, Daumas-Duport's grading, bromodeoxyuridine labeling index, and proliferating cell nuclear antigen counts were well correlated. Most small gliomas were histologically benign, localized, and removable if not in eloquent areas of the brain. However, some cases showed high-grade glioma and invasive character at the early stage, resulting in a poor outcome.

Adolescent↗
PubMed1992

Suprasellar germinomas; relationship between tumour size and diabetes insipidus.

The clinical and neuro-endocrinological aspects of 17 suprasellar germinoma patients treated between 1972-1991 are reported. Surgical extirpation was not initially attempted, but all patients received irradiation with or without a biopsy. Sixteen of those have led useful lives with appropriate hormonal replacement therapy during a mean follow up of 8 years. Seven tumours at diagnosis were less than 2 cm in diameter (type 1), nine tumours more than 2 cm (type 2), and one double midline tumour was of unknown size. All 7 type 1 patients required 1-deamino-8-D-arginine-vasopressin (DDAVP) to control diabetes insipidus (DI), but only 2 of the 9 type 2 patients have needed DDAVP since completion of the treatment. Patients with smaller tumours required more DDAVP following tumour disappearance, than those with larger tumours. The prognostic indicators for the post-treatment course of DI and retarded growth appeared to be the tumour size and the age at diagnosis. We also emphasize the absence of metastasis in unoperated cases and the use of tumour markers as a diagnostic criterion which obviates surgical acquisition of tissue to make the diagnosis. Possible reasons are discussed and the literature reviewed.

Adolescent↗
PubMed1991

Three-dimensional observations on microvascular growth in rat glioma using a vascular casting method.

The microvascular growth of ethylnitrosourea-induced rat glioma was observed using vascular casting and scanning electron microscopy (SEM). Light microscopy showed central necrosis and marginal invasive tumor cell growth with increased vascularity, and suggested that adopted pre-existing circulation was dominant in the inoculated brain tumors. In SEM, numerous buds or nodular protrusions and a few large and tortuous vessels along the tumor margin were seen at the early stage. In the intermediate stage, microaneurysms, buds with septum formation and anastomotic arches appeared, and these tumor vessels became more tortuous and larger, and extended as the tumor grew. Several "potato-shaped" huge vessels and linear nodular large vessels also appeared. In the late stage, glomeruli appeared and potato-shaped huge vessels increased in number. The neovascularization and microvascular growth of the tumors was characterized by three patterns: (a) growth of the parent vessels forming buds, (b) vascular growth in a meshwork formation producing glomeruli, and (c) vascular enlargement without a definite pattern creating potato-shaped huge vessels. The tumor vessels gradually lost their natural three-dimensional structure.

Animals↗
PubMed1989

Large dose fraction radiotherapy in the treatment of glioblastoma.

Twenty-four adults with glioblastoma multiforme (astrocytoma, grade 4) underwent postoperative large dose fraction radiotherapy (LDFR; 5 Gy twice weekly) with Linac X-rays. The outcome in this group was compared with that of 26 patients who received conventional fractionated radiotherapy (CFR; 2 Gy 5 times weekly). The time, dose, and fractionation (TDF) factor was about 100 in both groups. The survival rates following LDFR and CFR were, respectively, 63% vs 65% at 1 year; 36% vs 8% at 2 years; 17% vs 4% at 3 years; and 4% vs 0% at 5 years. Although the survival curve for LDFR was superior to that for CFR, the difference was not statistically significant. Autopsies of nine LDFR and 13 CFR patients showed no residual tumor in one case and no cases, respectively; small residual tumor in three cases in each group; extensive coagulation necrosis of the tumor and surrounding brain tissue in one LDFR and four CFR patients; tumor proliferation in three LDFR and four CFR cases; and mixed glioblastoma and fibrosarcoma in one LDFR and two CFR patients. These results suggest that maximum tumor removal followed by LDFR may offer a better prognosis for patients with glioblastoma than that offered by surgery plus CFR.

Adult↗
PubMed1989

[Histopathologic changes and tumor cell kinetics after hyperthermia and/or radiation therapy in a rat glioma model: bromodeoxyuridine (BUdR) labelling index].

Single and combined treatment of interstitial microwave hyperthermia (HT) and radiation therapy (RT) were delivered to rat glioma models. The animal model tumors were induced by intracerebral inoculation of a small piece of G-XII glioma tissue to 6-8 week-old rats. Heating to about 44 degrees C at the surface of the inserting antenna using a 2450 MHz microwave was carried on for 30 minutes. A single dose of 800 r to the whole head was delivered by deep X-ray apparatus. In combined treatment, heating immediately preceded irradiation. Following treatment, animals were sacrificed at 1, 3, 6, 12, 24, 48, 72 and 96 hours. BUdR was administered intraperitoneally 1 hour before sacrifice. Microscopically, in HT, tumor cells became eosinophilic and separated from each other. Some of them were necrotic. Macrophage infiltration in tumor tissue was recognized after 72 hours. BUdR labelling indices were less than 1% till 24 hours had passed, then became 25% at 48 hours, nearly equal to that of the control animals. In RT, ballooning of the tumor cells was prominent, and some of the tumors became necrotic. Lymphocyte infiltration of the tumor tissue was occasionally seen. BUdR labeling indices decreased slowly; less than 10% in 24 hours, but continued until 96 hours had passed. Combined treatment of HT and RT showed addictive effect of histological changes and suppression of tumor cell growth.

Animals↗
PubMed1988

[Effect of hyperthermia in combination with radiation therapy in a rat glioma model].

Rat glioma model was used to evaluate the effect of hyperthermia with and without radiation therapy. The animal model was induced by left frontal burr hole opening and inoculation of a small piece of G-XII glioma tissue to 6- to 8-week-old rats. The therapeutical experiments were given 10-14 days after inoculation of the tumor. Interstitial heating at 44 and 45 degrees C at the surface of the inserting probe using 2450 MHz microwave was delivered for 30 minutes. Deep X-ray whole head irradiation of 800 R using Stabilipan 2 (Siemens) was given just after the hyperthermia therapy. The survival of treated animals of hyperthermia, radiation, and combination of hyperthermia and radiation was significantly superior to that of non-treated control group. There was no significant difference of survival among the treated groups, though median survival was longest in the group of combination therapy of hyperthermia and radiation. Large tumors developed at the time of death in all the control and the treated animals. Histological examination showed some tendencies of macrophage infiltration in tumor tissue of hyperthermia therapy.

Animals↗
PubMed1986

Clinical pathology of primitive gliomas in the cerebrum.

To clarify the biological features of primitive gliomas in the cerebrum and clearly distinguish them from malignant or anaplastic gliomas and glioblastomas, we studied eight cases clinically and pathologically. Our evaluations included immunohistochemical and electron microscopic observations. We divided the patients into two groups, children and young adults. Most tumours appeared as ring-like, enhanced masses on computed tomography and avascular or ring-like, vascular masses on angiography. Macroscopically, the tumours were well demarcated and contained cysts. Occassionally we found tumour dissemination. Microscopically, the tumours were composed of small, round cells without remarkable structural features. Ependymal, astroglial, and oligodendroglial differentiation was evident, in varying proportions; tumours in which the differentiated areas constituted more than half of the mass were classified as poorly differentiated gliomas. By these criteria, this series comprised four undifferentiated and four poorly differentiated gliomas. Cell anaplasia and polymorphism were rare in both undifferentiated and differentiated areas of the tumours. Immunohistochemical and electron microscopic examinations also revealed glial differentiation. These primitive gliomas appear to be biologically similar, but not identical, to cerebellar medulloblastomas. In this series, five patients died because of recurrence or dissemination. Whole brain and spinal irradiation should be considered after total or subtotal surgical removal.

Adolescent↗
PubMed1986

Diagnosis of germinal neoplasm in the thalamus and basal ganglia.

Germinal neoplasms originating in the thalamus and basal ganglia were histologically verified by stereotactic biopsies in five cases and by other methods in three cases. Immunoperoxidase staining was performed on the tumors using antibodies against human chorionic gonadotropin and placental alkaline phosphatase. The presence of human chorionic gonadotropin was demonstrated in one germinoma and two mixed tumors, but not in three germinomas. Placental alkaline phosphatase was demonstrated to be present in four germinomas and one mixed tumor. Stereotactic biopsy specimens can be studied immunohistochemically, and the placental isoenzyme of alkaline phosphatase appears to be a new tumor marker for germinoma.

Adolescent↗
PubMed1982

A suprasellar embryonal carcinoma producing alpha-fetoprotein and human chorionic gonadotropin; treated with combined chemotherapy followed by radiotherapy.

A case of primary suprasellar embryonal carcinoma that produced alpha-fetoprotein and human chorionic gonadotropin in a 12-year-old girl is reported. Partial removal of the tumor and cis-platinum-based combined chemotherapy followed by local radiotherapy resulted in a definite regression of the tumor and improvement from clinical signs and symptoms. After these treatments, the concentrations of alpha-fetoprotein and human chorionic gonadotropin in both serum and cerebrospinal fluid decreased to undetectable levels. Serum basic fetoprotein, another tumor marker, can be a tool for evaluating the clinical course following postoperative chemotherapy.

Bleomycin↗
PubMed1978

Prazosin and clonidine for moderately severe hypertension.

In a single-blind comparative study of the cases of 30 moderately hypertensive patients, clonidine hydrochloride and prazosin hydrochloride had similar effectiveness in lowering blood pressure. Neither agent had significant effects on the renin-aldosterone axis. Addition of polythiazide to prazosin and chlorthalidone to clonidine notably increased the antihypertensive effect of both drugs. Serum cholesterol levels were observed to decrease when prazosin and clonidine were given and to rise when the diuretics were added to the regimen. The patients treated with clonidine were troubled by side effects, particularly drowsiness and dry mouth. Prazosin was better tolerated, with side effects tending to diminish with time. The "first-dose" effect was seen in two patients given prazosin, but it did not limit treatment. Both diuretics induced notable hypokalemia.

Adult↗