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Biomedical subjects

H Fukasawa

Publications and source records attributed to H Fukasawa.

At least 91 records · Page 5Linked to original sources
PubMed1991

Drug Stimulated DNA Cleavage Mediated by Cauliflower Topoisomerase II.

We have investigated cauliflower (Brassica oleracea) topoisomerase II with respect to its interaction with DNA and demonstrate that the enzyme shares the characteristics of topoisomerase II purified from a variety of phylogenetically remote organisms. In the presence of the 2-nitroimidazole Ro 15-0216, cauliflower topoisomerase II-mediated DNA cleavage is extensively stimulated (approximately 20-fold) only at a site recognized as a major cleavage site for the enzyme in the absence of drug. The conservation of the enzyme's DNA specificity in the presence of Ro 15-0216 is in contrast to the effect exerted by traditional topoisomerase II inhibitors, which cause enzyme-mediated cleavage to take place at a multiple number of DNA sites. Ro 15-0216 may therefore prove useful as a tool in the elucidation of the enzyme's DNA interaction sites and its involvement in nucleic acid metabolism in plant cells.

Journal Article↗
PubMed1991

Attenuated neuropathology by nilvadipine after middle cerebral artery occlusion in rats.

We investigated the effects of nilvadipine, a calcium antagonist, on cerebral ischemia in rats. Under halothane anesthesia, 30 rats had a 3-0 nylon suture introduced through the extracranial internal carotid artery to occlude the left middle cerebral artery. Nilvadipine was dissolved in polyethylene glycol 400. Immediately following occlusion, group 1 rats (n = 10) were treated subcutaneously with vehicle and group 2 and 3 rats were treated with 1.0 (n = 10) and 3.2 (n = 10) mg/kg nilvadipine, respectively. Perfusion fixation was performed 24 hours later, and the histopathologic outcomes were quantified. In group 1 infarct volume was 28.2 +/- 11.4% of the total cerebral volume; in groups 2 and 3 infarct volumes were 25.5 +/- 11.6% (NS) and 13.9 +/- 9.2% (p less than 0.05 different from group 1), respectively. Nilvadipine decreased ischemic neuronal injury in a dose-dependent manner and may be of use in the treatment of cerebral ischemia.

Animals↗
PubMed1991

[A case of adult pilocytic astrocytoma in the right temporal lobe].

A case of adult pilocytic astrocytoma in the right temporal lobe is reported here. The patient was a twenty-four year old man, who came to the neurological division of our hospital on October 6, 1987 because of repeated consciousness-loss attacks accompanied with uncinate fit. He had no neurological deficits. However, an EEG revealed spike-and-wave complexes in the right temporal region, and a CT scan showed a small cystic lesion in the right temporal lobe. A diagnosis of psychomotor seizure was made, and the administration of anticonvulsants was started. The incidence of attack then decreased, but after approximately two years of drug therapy the attacks increased again. A CT scan was again performed, and revealed that the lesion in the right temporal lobe was enlarging. Also a noticeable enhanced lesion, identified as a mural nodule was found in the post-contrast enhancement study. A brain tumor was then suspected, and he was admitted to the neurosurgical division on October 11, 1989. He had no neurological deficits on admission. An MRI showed a low intensity lesion in the T1 weighted image, and a high intensity lesion in the T2 weighted image. A cystic lesion with a marked enhanced mural nodule was also found in the base of the right temporal lobe, according to the Gd enhancement study. Perifocal edema was not recognized. Cerebral angiography showed no positive findings. Positron emission tomography (PET), using H2(15)O, revealed low perfusion at or around the lesion, and PET using [11C]-methionine revealed an accumulation of methionine at the lesion. A diagnosis of low-grade glioma was made, and a right temporal craniotomy, for the purpose of totally removing the tumor was performed on October 26, 1989.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[A case of aortoduodenal fistula following radiotherapy of retroperitoneal metastatic disease].

A new case of aortoduodenal fistula was added to the five cases previously reported in the literature, in which malignancy and/or its treatments could be implicated. This 67 year-old woman, six years previously had been placed on a therapy including irradiation on the pelvis for cancer of uterine cervix. For this time she underwent a radiotherapy completed in a total dose of 55.6 Gy combined with hyperthermia and chemotherapy for retroperitoneal metastatic disease with excellent response. Three months later she had hematemesis followed by melena and deteriorated to hemorrhagic shock. Emergent aortography detected contrast extravasation from the aorta with subsequent opacification of the duodenum, and immediate intraaortic balloon occlusion was done, but she died soon thereafter. Postmortem examination revealed the fistula from the aorta just above the bifurcation to a 2 by 1.5 cm. area of the posterior wall of the third portion of the duodenum. Accentuated arteriosclerosis in locally irradiated portion of the aorta, obstruction of small arteries from organized thrombus and hyaline necrosis in the wall of the fistulous tract were defined without evidence of tumor invasion. Based upon the findings of the patient reported herein, radiation might be another possible etiologic factor in aortoduodenal fistula, as well as tumor invasion per se.

Aged↗
PubMed1990

Therapeutic effects of hyperbaric oxygenation on acute focal cerebral ischemia in rats.

The effects of hyperbaric oxygenation on acute focal cerebral ischemia in rats were investigated. All rats suffered 4-hour middle cerebral artery occlusion. Nontreated controls had a 27.9% +/- 5.5% infarct volume, and a left/right hemispheric volume ratio of 109% +/- 3%. Animals treated between 2.5 and 3.5 hours following occlusion had an 18.1% +/- 9.7% infarct volume (p less than 0.01), and a 105% +/- 3% left/right hemispheric volume ratio (p less than 0.001). In conclusion, at least until 4 hours following an ischemic insult, hyperbaric oxygenation reduces ischemic neuronal injury and brain edema following middle cerebral artery occlusion in rats treated between 2.5 and 3.5 hours following occlusion.

Animals↗
PubMed1989

Effects of lipolytic and antilipolytic agents on glycerol and free fatty acid release from isolated adipocytes of normal and diabetic rats.

Isolated adipocytes from severely diabetic rats exhibited hypersensitivity to epinephrine at low concentrations (0.05-0.1 microM) on lipolysis, compared with isolated adipocytes from normal and mildly diabetic rats. Hypersensitivity to dibutyryl cyclic AMP and theophylline at concentrations from 0.05 to 0.50 mM was not observed in adipocytes of severely diabetic rats. Insulin could not exert an inhibitory effect on epinephrine-induced lipolysis in adipocytes of severely diabetic rats. In isolated adipocytes from normal rats, hyperosmolarity due to the combination of 50 mM glucose and 100 mM sodium chloride only had an inhibitory effect on 0.25 microM epinephrine-induced lipolysis. Ten mM beta-hydroxybutyrate did not inhibit lipolysis caused by epinephrine although any lipolysis stimulated by epinephrine, dibutyryl cyclic AMP and theophylline was inhibited by insulin. Our present findings may partly explain insulin resistance in the severely diabetic state and the pathogenesis of the absence of ketosis in hyperglycemic hyperosmolar conditions.

3-Hydroxybutyric Acid↗
PubMed1989

[A case of malignant ovarian tumor complicated by pregnancy, from the standpoint of tumor marker and quality of life].

It has been reported that malignant ovarian tumor is complicated in a ratio of one to 25,000 pregnancies. In the present study, a 22-year-old, nulliparous woman was presented, who had had her right ovary extirpated for serous cystadenoma (low potential for malignancy) and had undergone chemotherapy previously. Seven years later, she was subjected to celiotomy in the fourth month of gestational age because of left ovarian tumor. Intraoperative work-up disclosed a mucinous cystadenoma (low potential for malignancy) of stage Ia (FIGO). Left salpingo-oophorectomy and omentectomy were undertaken, and fetus-bearing uterus was preserved for the sake of the patient. Serum CA 19-9, with a preoperative level of 106.7 U/ml, fell exponentially into the normal range one month after the operation, and she successfully gave birth to a baby at term. After that, combination chemotherapy was instituted against an elevated level of CA 19-9, and she has been in remission while caring for her child.

Adult↗
PubMed1988

Efficacy of glucose, ouabain and an aldose reductase inhibitor on 2-[3H] myo-inositol uptake by human, rat and rabbit erythrocytes.

Myo-inositol uptake by erythrocytes from humans, rabbits and rats was studied with an isotope technique. In human erythrocytes, the inhibitory effect on myo-inositol uptake was stronger with glucose than with ouabain. However, an aldose reductase inhibitor (ONO-2235, 100 microM) or insulin (200 microU/ml) failed to correct the decrease in myo-inositol uptake in packed RBC, produced by either 10 mM glucose or 2mM ouabain. Ten mM ouabain had an inhibitory effect on myo-inositol uptake in all species, but an inhibitory effect was not observed with 20 mM glucose in rabbit erythrocytes. The results suggest that myo-inositol uptake by erythrocytes may be dependent on the active transport system via sodium-ATPase and that erythrocytes may not be a suitable model to monitor the possible effect of an aldose reductase inhibitor on myo-inositol concentrations in other tissues concerned with diabetic complications.

Aldehyde Reductase↗
PubMed1986

[Computer-aided macroscopic morphometry of the brain--estimation of the volume and surface area of the cerebral cortex].

A computer-aided morphometric method is described for evaluating the volumes and surface areas of brain structures from cut-surface images. This method consists of representing the topographical features of the cut surface as line drawings of closed curves and computing the magnitude of three-dimensional object from measurements made on two-dimensional sections. After fixation in 15% formalin for at least two weeks, the supratentorial brain is cut coronally at intervals of d (approximately 10 mm). The thicknesses of the extreme anterior and posterior slices are measured (d',d"). All the cut surfaces are numbered (1 less than or equal to i less than or equal to n), photographed, printed at a constant magnification of about 1.5, and the anatomical locations are specified on each print. The boundary lines of the main structures are classified into several categories: the cortical line, subcortical line, ventricular line, etc. Each of the classified line is reduced to a set of simple closed curves and entered into the computer in digitized form. The perimetric lengths as well as encircled areas of the constituent figures are computed and the classified totals of the boundary length and area of brain structures are determined for individual cut surfaces. At the same time, the data are processed to be displayed on CRT as lines of different colors according to the classification. The cerebral cortical volume is estimated from the series of its cut-surface using the trapezoidal rule.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral Cortex↗
PubMed1986

[A case of pineocytoma presenting with symptoms like normal pressure hydrocephalus].

A pineocytoma in an old man, whose initial symptoms resembled a normal pressure hydrocephalus, is reported. This 67-year-old man gradually became uncommunicative and difficult to walk alone in three months. Just before visiting our clinic, his family also noticed his nocturnal urinary incontinence. CT scan on admission disclosed tumor in the posterior wall of the third ventricle, and subsequent hydrocephalus. This oval, isodense tumor was homogeneously enhanced after the injection of contrast medium on CT scan. The vertebral angiography showed a mass in the pineal region with no vascular staining. Ventricular drainage, the opening pressure of which was 100 mmH2O, could not offer cytological verification of the tumor. By the infratentorial supracerebellar approach, the tumor was successfully extirpated, and the post-operative course was uneventful. The microscopic study revealed the nature of this tumor to be well compatible with that of a pineocytoma.

Aged↗
PubMed1985

Effects of a fructose-rich diet and the aldose reductase inhibitor, ONO-2235, on the development of diabetic neuropathy in streptozotocin-treated rats.

Streptozotocin-diabetic rats were maintained on a 72% fructose diet for 4 weeks and some were treated with an aldose reductase inhibitor (either alrestatin: 0.9 g . kg-1 . day-1 or ONO-2235: 50 mg . kg-1 . day-1). Fructose feeding significantly influenced the development of impaired motor nerve conduction velocity in the diabetic rats and this effect was positively correlated with sorbitol accumulation in the sciatic nerve of diabetic rats maintained on a fructose-rich diet. Treatment with ONO-2235, a new aldose reductase inhibitor, prevented both slowing of motor nerve conduction velocity and elevation of nerve sorbitol concentration. On the other hand, erythrocyte sorbitol levels were significantly correlated to those of the sciatic nerve (r = 0.86, p less than 0.001) and the retina (r = 0.91, p less than 0.001) in these animals. Thus, our findings suggest that increased polyol pathway activity may be related to the pathogenesis of diabetic neuropathy and erythrocyte sorbitol concentrations may prove a useful indicator for the presence of diabetic complications.

Aldehyde Reductase↗
PubMed1985

Computed tomography of cerebral infarction along the distribution of the basal perforating arteries. Part I: Striate arterial group.

Computed tomographic (CT) manifestations of cerebral infarction along the distribution of the basal perforating arteries were reviewed in correlation with cerebral angiography. Infarcts in the territories of perforators were demonstrated individually based on knowledge of their three-dimensional distribution as demonstrated by microangiography of cadavers. In Part I of the study, the areas supplied by the medial (MSA) and lateral striate arteries (LSA) were examined. Infarction along the branches of the MSA usually involved the antero-inferior portion of the corpus striatum, immediately posterolateral to the most inferior part of the frontal horn of the lateral ventricle. Infarcts along the branches of the LSA abutted the territory of the MSA posteriorly and superiorly and involved the posterolateral region of the corpus striatum. Clinical and neuroradiological correlations are discussed.

Cadaver↗
PubMed1985

Computed tomography of cerebral infarction along the distribution of the basal perforating arteries. Part II: Thalamic arterial group.

Computed tomographic (CT) manifestations of cerebral infarction along the distribution of the basal perforating arteries were reviewed and correlated with cerebral angiography. Infarcts in the territories of perforators were demonstrated individually based on knowledge of their three-dimensional distribution as shown by microangiography of cadavers. In Part II of the study, the posterior areas supplied by the thalamic arteries were examined. Infarcts in the area supplied by the thalamotuberal arteries involved the anterior pole of the thalamus; those in the area of the thalamoperforate arteries involved the medial portion of the thalamus, along the lateral wall of the third ventricle; those in the area of the thalamogeniculate arteries involved the posterolateral portion of the thalamus; and those in the area of the choroidal arteries of the lateral ventricle involved the most posterolateral and dorsolateral portions of the thalamus. Clinical and neuroradiological correlations are discussed.

Arteries↗