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Biomedical subjects

M Kowada

Publications and source records attributed to M Kowada.

At least 127 records · Page 7Linked to original sources
PubMed1988

Early and late stage positron emission tomography (PET) studies on the haemocirculation and metabolism of seemingly normal brain tissue in patients with gliomas following radiochemotherapy.

Haemocirculatory and metabolic changes in seemingly normal brain tissue following radiochemotherapy including nimustine hydrochloride (ACNU) and tegafur (FT) were analyzed using oxygen-15 and fluorine-18 positron emission tomography (PET) in seven patients with gliomas. At an early stage (within one month) after radiochemotherapy, marginal increases in regional cerebral blood flow (rCBF) and cerebral blood volume (rCBV) were found contralateral to the tumour in gray matter which was apparently normal brain structure, as seen on computerized tomography (CT). The oxygen extraction fraction (rOEF) decreased significantly (p less than 0.05 by a paired-t test) from that of the pretreatment study, due to surgical decompression and radiochemotherapy. At the late stage (three to thirty-one months with a mean of thirteen months), rCBF decreased significantly from the early stage study (p less than 0.05); oxygen consumption (rCMRO2) fell in all cases significantly from the pretreatment study (p less than 0.01) and from the early stage study (p less than 0.05); consequently, rOEF remained unchanged at a level similar to the early stage study. Glucose consumption (rCMRG1) increased slightly as compared with the early stage study but failed to be restored to the level of the pretreatment study. Noteworthy was a coupling reduction of rCBF and rCMRO2--presumably, a late delayed effect of radiochemotherapy. These preliminary results indicate that with PET studies it may be possible to predict damage to normal brain tissue after radiochemotherapy.

Adolescent↗
PubMed1988

Wyburn-Mason syndrome: report of a rare case with computed tomography and angiographic evaluations.

A case of Wyburn-Mason syndrome comprising unilateral retinocephalic vascular malformations is reported in a 7-year-old girl presenting with proptosis of the left eye associated with injection of the bulbar conjunctiva. This rare congenital vascular disorder is reviewed in the literature, and in particular the neuroradiological findings are detailed in the presented case.

Cerebral Angiography↗
PubMed1988

In vitro damage of isolated DNA from two brain tumor cell lines induced by a water-soluble antitumor nitrosourea.

We report the DNA sites damaged by the antitumor drug, nimustine hydrochloride (ACNU), in highly reiterated DNA sequences of rat glioma cells. A reiterated fragment of 370 base pairs (bp), obtained after Hind III restriction endonuclease digestion of rat glioma C6 or 9L cells DNA, was divided into 167 and 203 bp by subsequent Hae III enzyme reaction. The reaction of end-labelled 167 and 203 bp fragments with ACNU resulted in scission breaks corresponding to the locations of guanine. Moreover, ACNU and subsequent piperidine hydrolysis produced more frequent breaks of the phosphodiester bonds at the guanine positions, thus forming alkali-labile sites. These results indicate that the preferred site of DNA strand scission induced by ACNU is at guanine positions.

Animals↗
PubMed1988

DNA lability induced by nimustine and ramustine in rat glioma cells.

The DNA labile sites induced by two nitrosoureas, nimustine (ACNU) and ramustine (MCNU) synthesised in Japan, have been examined in highly reiterated DNA sequences of rat glioma cells. Reiterated fragments of 167 and 203 base pairs (bp), obtained after Hind III and Hae III restriction endonuclease digestion of rat glioma cells DNA, were used as target DNA sequences to determine the labile sites. In vitro reaction with ACNU and MCNU resulted in scission products corresponding to the locations of guanine. Subsequent piperidine hydrolysis produced more frequent breaks of the phosphodiester bonds at guanine positions, thus forming alkali-labile sites.

Animals↗
PubMed1988

[A histologically-verified triple cancer--report of a rare case involving a primary brain tumor].

Histologically-verified triple cancers that include a malignant brain tumor are rare. According to the Japan Autopsy Annuals, only 8 cases since 1958 have been so far documented. A case combining a malignant melanoma, a medulloblastoma, and a thyroid cancer is herein presented, along with a review of the literature. In March, 1983, a 27-year-old female who, 7 years prior to admission, had had malignant melanoma on the right hand removed, complained of headaches and vertigo. A CT scan revealed a right cerebellar mass lesions, which subsequently proved to medulloblastoma. Three years later, a struma was found and subtotal thyroidectomy revealed a papillary adenocarcinoma.

Adenocarcinoma, Papillary↗
PubMed1988

Primary malignant astrocytoma of the cerebellum in children. Report of a case with electron microscopic and cytofluorometric DNA evaluation.

The case of a 1-year-old girl with primary malignant astrocytoma of the cerebellum is presented with special reference to ultramicroscopic study and cytofluorometric DNA analysis. The routine light microscopic study was not pathognomonic because of the immaturity of the composing cells. The glial fibrillary microfilaments characteristic of astroglial cells were confirmed by means of electron microscopy. Cytofluorometrically, the DNA histogram of this case revealed a prominent peak in the 4C region, with considerable dispersion to the 8C region, indicating the polyploidic and heterogeneic pattern of malignant tumors.

Astrocytoma↗
PubMed1988

[Analysis of DNA damage induced by nitrosourea derivatives in rat brain tumor cells using a sequencing procedure].

DNA damages caused by various anticancer nitrosourea compounds such as ACNU and MCNU were studied. Reiterated fragments of 167 and 203 base pairs (bp) were obtained after Hind III and Hae III restriction endonuclease digestion of 9L rat brain tumor DNA. The end-labeled reiterated fragments were reacted with ACNU and MCNU, which resulted in the scission breaks corresponding to the locations of guanine on an extended Maxam-Gilbert sequencing gel. Subsequent piperidine hydrolysis yielded scission products more frequently. These results indicate that nitrosoureas such as ACNU and MCNU generate DNA scission breaks and/or alkali-labile sites preferentially at the position of guanine moieties in rat brain tumor DNA.

Animals↗
PubMed1987

Positron emission tomographic evaluation of radiochemotherapeutic effect on regional cerebral hemocirculation and metabolism in patients with gliomas.

Hemocirculatory and metabolic changes in tumor regions and the remote brain structure were analyzed using oxygen-15 and fluorine-18 positron emission tomography (PET) in eight patients with gliomas after radiation and chemotherapy of 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) and N-(2-tetrahydrofuryl)-5-fluorouracil (FT-207). In the tumor regions after the radiochemotherapy, regional cerebral blood flow (rCBF) and cerebral blood volume (rCBV) varied widely and there was a tendency for oxygen consumption (rCMRO2) to fall. The change in glucose consumption (rCMRG1) was especially noteworthy with regard to clinical correlations. Six patients with decreased rCMRG1 values had 16% to 29% regressions in tumor size measured by X-ray computerized tomography (CT), and showed some period of clinical relief. In contrast, one patient with an increased rCMRG1 value had some progression of tumor growth, and there were no clinical amelioration. The hemocirculation and metabolism of the contralateral gray matter seem to fluctuate by various factors as intracranial pressure and the effectiveness of the therapy. In gliomas therapy, tumor rCMRG1 values can be a good indicator of therapeutic effectiveness.

Adolescent↗
PubMed1987

Immunosuppressive acidic protein in patients with brain tumours: a preliminary report.

The present investigation was conducted to document the serum concentrations of immunosuppressive acidic protein (IAP) in patients with intracranial tumours utilizing the single radial immunodiffusion method. Among 46 pre-operative patients, elevated serum levels of IAP were found in nine of 16 patients with gliomas, six of nine patients with metastasis, and two of 21 patients with non-glial, histologically benign intracranial tumours. The mean value of serum IAP in glial or metastatic tumours was found significantly higher than that of either non-glial or normal individuals. It was postulated that serum IAP levels could correlate with a grade of anaplasia and malignancy of the tumour. And it was also of note that serum IAP levels appeared to have a tendency to decrease in response to the treatment. In addition, serum IAP levels were found correlated with the clinical condition and course of disease as evaluated by performance status and erythrocyte sedimentation rate. Therefore, it was suggested that measurement of serum IAP could be, at least in part, useful in validating the histologic analysis of brain tumours, in following responses to treatment when used as a tumour indicator, and in monitoring the progress of the disease in patients in terms of performance status.

Adolescent↗
PubMed1987

Congenital glioblastoma of the cerebellum with cytofluorometric deoxyribonucleic acid analysis.

A case of congenital glioblastoma arising from the cerebellum is presented with special reference to microspectrophotometric deoxyribonucleic acid (DNA) analysis of the tumor cells. Seven cases of this condition are already in the literature. The prognosis is poor and most of the reported cases survive no more than 2 months. Cytofluorophotometric DNA studies were helpful in elucidating the extreme heterogeneous distribution of DNA contents of the tumor cells, suggesting a biological aggressiveness probably related to the rate of proliferation.

Brain↗
PubMed1987

Detection of DNA sites damaged by 1-(4-amino-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) using a DNA sequencing procedure.

A DNA sequencing technique was applied to the highly reiterated DNA from HeLa S3 cells in order to detect DNA damage induced by the antitumor drug, 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU). A DNA reiterated fragment of 92 base pairs (bp) was isolated by gel electrophoresis after EcoRI and EcoRI restriction endonuclease digestion. In the defined sequence of the 92 bp fragment, ACNU caused damage and modifications primarily at guanine moieties, leading to alkali-labile sites as determined by subsequent piperidine reaction on an extended Maxam-Gilbert sequencing gel. These results indicate that guanine moieties in double-stranded DNA are preferentially vulnerable to ACNU over other base moieties.

Base Sequence↗
PubMed1987

Pituitary enlargement associated with Addison's disease.

We report a case of Addison's disease with pituitary enlargement which could easily have been misinterpreted as a pituitary adenoma or other pituitary disease. Serial computed tomography following replacement therapy was essential to confirm the diagnosis.

Addison Disease↗