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Biomedical subjects

G Asano

Publications and source records attributed to G Asano.

At least 163 records · Page 9Linked to original sources
PubMed1987

[Different severity of brain ischemia between spontaneously hypertensive rats and Wistar-Kyoto rats induced by internal carotid infusion of arachidonic acid].

Arachidonic acid (AA) is a potent stimulator of platelet aggrgation and is known to induce endothelial cell damage and edema in the brain. An ischemic cerebral infarction model can be produced in rats by an internal carotid infusion of AA. In this study, water content, ATP and lactate in the brain and plasma prostaglandins (thromboxane B2; TXB2 and 6-keto-prostaglandin F1 alpha; 6-keto-PGF1 alpha) were measured and histological observations were made after an internal carotid infusion of AA in two strains of rats; stroke-resistant spontaneously hypertensive rat (SHRSR) and normotensive Wistar-Kyoto (WKY) rats. It is known that the blood pressure of the SHRSR begins to rise at about 8 weeks old. Throughout the study, AA was administered into the internal carotid artery under 2% fluothane anesthesia. In the first study, AA (1.7 mg/kg BW) was administered to 8- and 16-week-old rats and the length of survival was observed. In the second study, water content, ATP and lactate in the brain and plasma TXB2 and 6-keto-PGF1 alpha were measured 3 hours after AA (0.85 mg/kg BW) administration. In the third study, rats were perfusion-fixed 3 hours after the AA (1.7 mg/kg BW) infusion and cerebral arteries were observed by scanning electron microscopy (SEM). During the 6 hour observation period, there was no difference between the two groups in the number of 8-week-old rats which survived. However, the figure became significantly lower in the SHRSR at 16 weeks old. The water content in the bilateral cerebral hemispheres was significantly larger in the SHRSR than in the WKY rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Impaired intermediate-density lipoprotein triglyceride hydrolysis in familial lecithin:cholesterol acyltransferase (LCAT) deficiency.

A new lecithin:cholesterol acyltransferase (LCAT)-deficient family was found in Japan. In the proband, both LCAT activity and LCAT mass were deficient. The patient's parents, child, and sister, diagnosed as heterozygotes, had half-normal LCAT activity and LCAT mass. In the patient, an increase of intermediate-density lipoprotein (IDL, 1.006 less than d less than 1.019) fraction was observed. In postheparin plasma, both lipoprotein lipase and hepatic triglyceride lipase activities were low. Hydrolysis of [14C] triolein by human hepatic triglyceride lipase in patient IDL was decreased compared to that in IDL from normal postprandial serum. Preincubation of these IDL with normal plasma in the absence of 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB) increased the rate of hydrolysis, in the presence of DTNB, this increment was not observed. These results suggest that one cause of IDL increase in the LCAT-deficient patient might be the difficulty of hydrolysis of these lipoprotein particles by hepatic triglyceride lipase.

Adult↗
PubMed1987

Effects of polyprenoic acid on thermal injury.

This study was designed to determine the effect of polyprenoic acid on wound healing in rats after thermal injury and to compare the effect with healing in vitamin A deficient controls and in retinol-fed vitamin A deficient rats. Both polyprenoic acid and retinol visibly accelerated wound healing after thermal injury. Both enhanced the induction of platelets in the peripheral blood but neutrophils were not affected by polyprenoic acid. Histologically, in the hypo-vitamin A rat, polyprenoic acid administration increased both capillary formation and also the production of fibroblasts and collagen deposition in the wound by comparison with control vitamin A deficient animals; similar effects were produced by retinol feeding. These results indicate that both polyprenoic acid and retinol can facilitate wound healing. 3H-thymidine incorporation into dermal tissues showed that in polyprenoid-fed rats capillaries multiplied 1.3 times, epithelial cells 2.1 times, and fibroblasts 2.0 times faster than those in vitamin A-deficient animals; 3H-thymidine incorporation was greater after polyprenoid feeding than after retinol feeding. Polyprenoid thus stimulates both collagen deposition and neo-vascularization within burns, and so accelerates healing.

Animals↗
PubMed1986

Estrogen and progesterone receptors in gastric cancer.

Cancerous tissue from 86 patients with primary gastric cancer were examined for the presence of receptors for estrogen (ER) and progesterone (PgR). ER and PgR were present in 8 (15.4%) and 5 (9.6%), respectively, of 52 male patients, 9 (26.6%) and 7 (20.6%), respectively, of 34 female patients, a total of 17 (19.8%) and 12 (14.0%), respectively. One male patient (1.9%) and 4 female patients (11.8%) had both ER and PgR, and 40 male (76.9%) and 22 female patients (64.7%) showed no ER or PgR. The binding activity ranged from 6 to 200 fmol/mg protein for estradiol and from 5 to 58 fmol/mg protein for progesterone. ER- and/or PgR-positive cases were characterized grossly as Borrmann type 4, and microscopically as diffuse type with scirrhous growth pattern. The presence of ER and/or PgR in some gastric cancers indicates the possibility that sex hormonal factors are involved in these tumors.

Adult↗
PubMed1986

Early membrane damage during ischemia in rat heart.

Effects of ischemia on cell membrane of rat heart were investigated. The endothelial surface revealed the existence of ruthenium red-positive glycocalyx at the anionic site. Membrane bound enzyme as Na-K ATPase was mostly located in the inner side and pinocytotic vesicles of endothelial cell. The clumping and dispersion in glycocalyx of endothelial cells was observed in an ischemic heart and it may prove the functional disturbance of plasma membrane. A potential and functional defect with reduced activity of Na-K ATPase occurred within 1 hr of vascular ligation. The membrane dysfunction due to these molecular changes has been proved by the membrane permeability alteration as well as the intracytoplasmic localization of horseradish peroxidase as tracer.

Animals↗
PubMed1985

Primary neuroblastoma of the nasal cavity and review of literature.

Primary neuroblastoma of the nasal cavity is very rare, and it is one of the most difficult tumor to differentiate from other small round cell tumors. The present case was proved to be olfactory neuroblastoma by histological, electron microscopical and histochemical findings. This is the first case in which biogenic amines were proven by glyoxylic acid-induced fluorescence in vitro. Discussions were made on the pathological differences with adrenal neuroblastoma.

Adult↗
PubMed1984

Detection of islet cell surface antibodies by an indirect rosette assay, using islet cells and Protein A-labeled sheep red blood cells.

An indirect rosette assay for detecting islet cell surface antibodies (ICSA), the autoantibodies directed to the membranous antigens of islet cells, has been developed. In this assay, Protein A-conjugated sheep red blood cells (SRBC) were used. Both viable and fixed SRBC were available. The results obtained using this new method in insulin-dependent diabetes mellitus (IDDM) patients were not only sensitive, but also correlated with results of the indirect immunofluorescence method currently used for detecting ICSA. Furthermore, in studies of streptozotocin-treated diabetic mice or rats, the courses of ICSA appearance were successively demonstrated by this indirect rosette formation assay. Special advantages of this method are that materials are easily obtained and cost-effective, as the sample volume is small and the number of islet cells required is also small. Assays can be readily performed without a need for radioisotopic or fluorescent equipment. This method provides a reliable laboratory test for diagnosis of autoimmune diabetes mellitus.

Animals↗
PubMed1983

Mitochondrial function in canine experimental cardiac hypertrophy.

Concentric left ventricular hypertrophy was produced in puppies by coarctation banding of the aorta at age 7 weeks. Hemodynamic, morphologic and biochemical studies were carried out 18 months after the operation. Systolic blood pressure proximal to the aortic constriction was 216 +/- 16 mmHg in experimental dogs compared with 115 +/- 5 mmHg in littermate control dogs. Ejection fraction of control and experimental dogs were 59 +/- 4 and 64 +/- 7, respectively. The left ventricular end-diastolic pressure was 6.0 +/- 0.4 in control and 8.4 +/- 1.1 in experimental dogs. There was no sign of overt heart failure in the experimental dogs. Anatomical analysis of different regions of the heart indicated that LV mass in the experimental dogs was increased by about 60%. Ultrastructure of mitochondria in situ, as observed under electron microscope, was normal both in control and hypertrophic hearts. Mitochondria isolated from epicardial and endocardial regions of the stable hypertrophic hearts showed normal rates of respiration, phosphorylation, citrate synthase, and cytochrome c oxidase activities compared to those isolated from hearts of littermate control dogs. It was, therefore, concluded that mitochondrial function is adequately preserved to meet the increased demand for energy in this model of stable cardiac hypertrophy of long duration.

Animals↗
PubMed1983

Ischaemia-induced changes in canine cardiac sarcoplasmic reticulum.

Effects of myocardial ischaemia on sarcoplasmic reticulum (SR) of dog hearts were investigated. Regional ischaemia was produced by occlusion of the left circumflex artery, and a microsomal fraction enriched in vesicles of SR was isolated from subendocardium (Endo) and subepicardium (Epi) of control and ischaemic areas of the heart. No significant changes occurred in ischaemic Epi. A loss of in vitro activities (ie calcium transport and ATPase) was found for SR from ischaemic Endo which paralleled the changes in the histology of the tissue. At 5 min of coronary occlusion, Ca2+ binding and Ca2+-ATPase activities of SR from ischaemic Endo were normal. A decrease in the activities of SR was first evident at 15 min after the occlusion, decreased further at about 30 min and remained at that level at 60 min of ischaemia. The maximal rate of Ca2+ uptake did not parallel the Ca2+-binding and Ca2+-ATPase activities. The degree of cAMP-dependent phosphorylation by endogenous and exogenous protein kinase was not different between SR from control and ischaemic areas. A participatory role of SR in the ischaemic impairment of left ventricular systolic and diastolic performance is discussed.

Animals↗