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Biomedical subjects

H Fukasawa

Publications and source records attributed to H Fukasawa.

125 records · Page 7Linked to original sources

Comparative studies on polyguanylate polymerase and polyadenylate polymerase activities in the DNA-dependent RNA polymerase I fraction from cauliflower.

The properties of poly(G) polymerase and poly(A) polymerase activities in the DNA-dependent RNA polymerase [nucleosidetriphosphate: RNA nucleotidyltransferase EC 2.7.7.6] I fraction from cauliflower (Brassica oleracea var. botrytis) were comparatively investigated. The pH optimum, the effect of ionic strength, the effect of substrate concentration on the rate of synthesis, the effect of divalent metal ion concentration, and the time course of synthesis at different temperatures were all different for the three polymerase activities. The enzyme fraction preferentially utilized denatured DNA. Synthetic poly(C) and poly(U) were more effectively utillized for the synthesis of polyguanylate and polyadenylate, respectively. Further, it was found that poly(G) and poly(A) formed in vitro by the enzyme fraction had chain length of 25-28 and 84-89 nucleotides, respectively, and that poly (adenylate-gluanylate) chain was hardly formed when ATP and GTP were added together as substrates in the same reaction medium.

Adenosine Triphosphate↗

Sequential change of the pontine shape after cerebrovascular strokes.

Pontine cross-sectional area (Ap) and its area factor (f) were correlated with the lapse of time from the onset of stroke to death in 77 autopsy cases cerebrovascular strokes. In the cases without pontine hemorrhage, the sequential change of Ap was different from that of f, which indicated that the recovery of shape lagged behind the recovery of size. The result was attributed in part to a plastic property of the edematous brain substance and was considered important in evaluating angiographical changes of the brain and some pressure cones at autopsy.

Brain Edema↗

Glial and capillary density of the pontine white matter in swelling and atrophy.

A total of 48 autopsied brains were morphometrically examined for the relation between pontine geometry and structural parameters. In each case, the numerical density of neuroglial cells Nv(G) and the linear density of capillary network Lv(C) of the pontine white matter were determined stereologically from the counts of glial nuclear profiles and capillary transections per constant area of a histological section with a constant thickness. It was revealed that in general the glial numerical density increased with advancing atrophy and decreased with increasing swelling, whereas the capillary linear density remained fairly constant especially in the advanced stage of brain swelling. Further analysis of this relation using a model of pontine geometry has made it clear that the total capillary length in the swollen white matter increases probably at the expense of the capillary caliber as swelling advances. The changes in the ratio Lv(C)/Nv(G) under pathological conditions are emphasized and possible utility of classifying stages of acute brain swelling from a viewpoint of microvascular dimension is suggested.

Adult↗

[Intracranial extradural liposarcoma in the posterior fossa--a case report (author's transl)].

A case of liposarcoma, which originated primarily in the left infraauricular area and infiltrated to the posterior fossa, was reported. The patient was a 25-year-old housewife, who was admitted because of symptoms of intracranial hypertension. She showed left facial palsy and deviation of the tongue to the left without any cerebellar signs. Neurological examinations suggested a mass lesion in the posterior fossa. Suboccipital craniectomy was performed and the tumor sized 4 X 4 X 3 cm in the extradural space was partially removed. Microscopically, the tumor consisted of lipoblasts and diagnosed as liposarcoma. Intracranial liposarcoma, whether primary or secondary, is very rare and only several cases have been reported.

Adult↗

Morphometric estimation of brain swelling and atrophy.

A morphometric method was presented to estimate brain swelling or atrophy from the geometric characteristics of the pontine cross section. The ratio of the area (A) to the perimeter squared (L2) was termed "area factor" (f) and used as a factor indicating circularity. Normal standards for the net cross-sectional area (Ap) and the area factor (f) of the pons measured on paraffin sections were 3.43 approximately 4.87 cm2 and 0.0684 approximately 0.0740, respectively. Values exceeding these ranges suggested brain edema. The pontine area factors (f) of the control cases under 60 years of age were less spread out than Ap, whereas they exhibited larger individual variations over that age presumably as a result of varying involution of the brain. A close correlation was found between Ap and water content of the cerebral white matter, except in pontine hemorrhage. The correlation was particularly marked in the group of cerebral diseases other than stroke. The longitudinal length of the basis pontis (lp) was essentially the same in the normal brain and even in the stoke group excluding pontine and cerebellar hemorrhage. In severe brain swelling the pontine longitudinal length was rather reduced.

Adult↗

Analysis of 140 consecutive autopsy cases of cerebrovascular strokes in northern Japan.

On the autopsy findings of the 140 consecutive stroke cases, some characteristics of cerebrovascular diseases in this district were discussed. Predominance of intracranial hemorrhage (cerebral hemorrhage and subarachnoid hemorrhage) over cerebral infarction was still evident. Ruptured intracranial aneurysms were demonstrated in 98% of fatal subarachnoid hemorrhage. Compared with the autopsy data of other institutions, the age of death was generally low, the median age for cerebral hemorrhage, subarachnoid hemorrhage and cerebral infarction falling in the fourth, fifth, and sixth decade, respectively. Cerebellar hemorrhage was relatively frequent, while blood dyscrasias and other symptomatic hemorrhage constituted only a small part in contrast with the report of American authors. A dominant role of hypertension in causing strokes was concluded from both the heart weight and the clinical records.

Adolescent↗

Niceritrol prevents the decrease in red blood cell 2,3-diphosphoglycerate and neuropathy in streptozotocin-induced diabetic rats.

Nerve ischemia/hypoxia has been linked to the pathogenesis of diabetic complications. Red blood cell 2,3-diphosphoglycerate is an important regulator of peripheral tissue oxygenation; however, the relationship between 2,3-diphosphoglycerate concentration and diabetic complications has not been studied in detail. This investigation focused on the relationship between red blood cell 2,3-diphosphoglycerate and diabetic neuropathy, by measuring motor nerve conduction velocity and sciatic nerve blood flow in streptozotocin-induced diabetic rats. The effect of treatment with niceritrol, a nicotinic acid derivative that acts as a vasodilator and reduces serum lipid concentrations, on 2,3-diphosphoglycerate concentration and diabetic neuropathy was also examined. Untreated diabetic rats had significantly lower concentrations of red blood cell 2,3-diphosphoglycerate, higher concentrations of serum total cholesterol and triglyceride, as well as reduced motor nerve conduction velocity and sciatic nerve blood flow, compared to untreated normal rats. Niceritrol prevented these abnormalities without correcting hyperglycemia in diabetic rats, but had no effect on these parameters in normal rats. Red blood cell 2,3-diphosphoglycerate concentration and motor nerve conduction velocity showed a positive correlation with sciatic nerve blood flow and 2,3-diphosphoglycerate, respectively. These observations suggest that ischemia/hypoxia plays an important role in the development of diabetic neuropathy, and that niceritrol has a therapeutic effect on this condition by improving endoneurial ischemia/hypoxia.

2,3-Diphosphoglycerate↗

HER-2/neu expression in ovarian clear cell carcinomas.

HER-2 /neu is a 185-kDa glycoprotein and a transmembrane receptor with tyrosine kinase activity. Its overexpression is observed in 25-30% of primary breast carcinomas and is associated with a poor clinical prognosis. Recently, the U.S. Food and Drug Administration and the Japanese Ministry of Health, Welfare, and Labor approved the use of trastuzumab (Herceptin, Genentech, South San Francisco, CA) for the treatment of patients with metastatic breast carcinomas overexpressing HER-2 /neu. Results of clinical trials with Herceptin suggest that it may prolong the survival of patients with advanced metastatic breast carcinoma. Relatively little is known concerning the relationship between HER-2 /neu status and ovarian clear cell carcinoma. If HER-2 /neu overexpression status were demonstrable in ovarian clear cell carcinoma and a clinical correlation between overexpression and prognosis could be established, a rationale for clinical use of Herceptin for this tumor could be established. Our aim was to evaluate HER-2 /neu status in ovarian clear cell carcinomas. Fifteen ovarian clear cell carcinoma cases were immunostained for HER-2 /neu using HercepTest (DAKO, Glostrup, Denmark). Overexpression of HER-2 /neu was detected in only one case. Unlike in breast carcinoma, HER-2 /neu overexpression appeared to be uncommon in ovarian clear cell carcinomas. Herceptin may thus target only a small proportion of ovarian clear cell carcinomas and be of limited clinical value for treatment of this carcinoma.

Adenocarcinoma, Clear Cell↗

Unusual widening of Virchow-Robin spaces: MR appearance.

MR in two patients with unusual widening of the Virchow-Robin spaces showed multiple cystic foci up to 2 cm in diameter along the perforating medullary arteries in the cerebral white matter, mainly in one cerebral hemisphere. These areas were of the same signal intensity as cerebrospinal fluid on all pulse sequences. In one patient, the cystic foci in the white matter were biopsied and histologically confirmed to be large Virchow-Robin spaces.

Aged↗