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H Sano

Publications and source records attributed to H Sano.

At least 469 records · Page 26Linked to original sources
PubMed1992

Expression of Fos-like immunoreactivity by yohimbine and clonidine in the rat brain.

To elucidate the role of alpha 2-adrenoceptors in transcriptional control in the rat brain, we localized the Fos-like immunoreactivity (Fos-LI) induced by alpha 2-adrenoceptor agonists and by an antagonist. Injections of yohimbine (5 mg/kg, i.p.) into rats led to the induction of Fos-LI in areas with a dense alpha 2-adrenoceptor binding such as the locus coeruleus, the bed nucleus of stria terminalis, the central nucleus of amygdaloid complex, the paraventricular nucleus, the nucleus tractus solitarius, and ventrolateral medulla oblongata. Clonidine (500 micrograms/kg, i.p.) suppressed the Fos expression by yohimbine in these nuclei, and clonidine (100 micrograms/kg, i.p.) or guanabenz (4 mg/kg, i.p.) induced Fos-LI in oxytocin neurons in the paraventricular and supraoptic nuclei in the hypothalamus. Thus, the alpha 2-adrenoceptor is involved in transcriptional control via Fos expression in neurons related to autonomic and other functions.

Animals↗
PubMed1992

Glycogen storage disease type III with muscle involvement: reappraisal of phenotypic variability and prognosis.

A review of the case histories of 19 Japanese patients with enzymatically proven glycogen storage disease (GSD) III who developed muscular symptoms at various ages illustrates the phenotypic variability of this disease. There seem to be 4 subgroups of GSD III with muscle involvement according to the clinical symptoms. The first group of patients is characterized by the childhood onset of muscle weakness and hepatic disorders. The second group of patients develops muscular symptoms in adult years while the liver symptoms start in childhood. The third group includes the patients whose muscle weakness started in adult years long after liver symptoms in childhood had disappeared. The fourth group shows only muscular symptoms as adults without any sign or history of liver dysfunction since childhood. The prognosis for each subgroup seems to be different; however, none of them appears to be better than that for GSD I, as has been suggested previously.

Female↗
PubMed1992

Pre-treatment of a human T-lymphoblastoid cell line with L-asparaginase reduces etoposide-induced DNA strand breakage and cytotoxicity.

The effect of L-asparaginase (L-asp) pre-treatment on etoposide-induced DNA strand breakage and cytotoxicity was investigated. In a T-lymphoblastoid cell line, Molt 4, etoposide-induced DNA strand breaks, DNA-protein cross-links and cytotoxicity were reduced by pre-treatment with L-asp for 15 hr, but it did not cause these changes in a promyelocytic-leukemia cell line, HL-60, which is less sensitive than Molt 4 to L-asp. However, pre-treatment of Molt 4 cells with L-asp did not significantly alter the accumulation of [3H]-etoposide. Cell-cycle analyses showed an increase in G1-phase cells, a significant decrease in both S-phase cells and G2/M-phase cells pre-treated with L-asp in Molt 4 cells, but L-asp exposure did not result in any significant changes in HL-60 cells. On the other hand, L-asp pre-treatment did not affect topoisomerase-I (Topo-I) inhibitor, camptothecin (CPT)-induced DNA strand breaks or toxicity in Molt 4 cells. Our data imply that a decrease in S- and G2/M-phase cells following L-asp treatment may explain the reduction of etoposide-induced DNA lesions and cytotoxicity in Molt 4 cells, since topoisomerase-II (Topo-II) content or activity is a function of cellular proliferation status.

Asparaginase↗
PubMed1992

Comparison of thallium-201 and technetium-99m teboroxime myocardial single photon emission tomography with coronary arteriography.

Myocardial single photon emission tomography (SPET) using technetium-99m teboroxime (teboroxime) was studied and the results compared with those of thallium-201(thallium) SPET and coronary arteriography in 19 patients. Resting teboroxime SPET was performed initially. Two hours later, exercise teboroxime SPET was performed. Exercise ergometer tests for both teboroxime and thallium were carried out in a supine position. The levels of exercise achieved for both tests were similar. Agreement for the identification of myocardial segments between thallium SPET and teboroxime SPET was 147/171(86%) (NS). When a significant stenosis was defined as greater than or equal to 75% or greater than or equal to 50%, agreement between two radiopharmaceuticals for the detection of diseased vessels was 89% (NS, k = 0.601) or 88% (NS, k = 0.713), respectively. In only 2/19 cases were inferior and posterior segments (3/171) difficult to interpret in teboroxime SPET due to hepatic activity. Thus, teboroxime SPET with a short data acquisition time resulted in a rapid completion for each study and had a good correlation with thallium SPET.

Adult↗
PubMed1992

Polyphosphoinositide metabolism in hypertrophic rat heart.

The accumulations of inositol-1,4,5-trisphosphate (IP3) and inositol-1,3,4,5-tetrakisphosphate (IP4) after hormonal stimulation may have a physiological role, possibly by alteration of Ca2+ levels in cardiac tissue. But the accumulation of inositol polyphosphate in a pathophysiological condition has not been studied. We investigated phosphatidylinositol-4,5-bisphosphate (PIP2) metabolism in hypertrophic cardiac myocytes, and clarified that the accumulations of IP3, IP4 and diacylglyceride after stimulation with norepinephrine were significantly enhanced in isolated myocytes from spontaneously hypertensive rat heart. Phospholipase C activity increased with age in SHRSP heart cells. These data suggest that PI turnover pathways, which can be mediated by both phosphatidylinositol-4,5-bisphosphate and diacylglyceride, may play an important role in development of hypertrophy in the hearts of rats with spontaneous hypertension.

Animals↗
PubMed1992

Dentin thickness, hardness, and Ca-concentration vs bond strength of dentin adhesives.

The relationship between the tensile bond strength (TBS) and three dentin characteristics: remaining dentin thickness (RDT), Ca-concentration, and hardness, were investigated. Sixty-two extracted bovine incisors, divided into four groups, were prepared using 600-grit SiC paper to create flat dentinal surfaces. The materials tested in this study consisted of three commercially available and one experimental dentin bonding systems. The TBS and modes of failure were determined after storage for 24 h in 37 degrees C water. Then RDT, Ca-concentration, and hardness were measured. Data were statistically compared with TBS of each group. The mean bond strength of the commercial materials ranged from 2.5 +/- 0.9 MPa to 7.7 +/- 2.8 MPa. Correlations with Ca-concentration and RDT varied, depending on the product. The bond strength of the experimental material was 9.2 +/- 4.4 MPa and significantly correlated with RDT and hardness. With two of the dentin bonding agents, specimens showed a high number of cohesive fractures in dentin, 40% to 82%. It was concluded that the variability of TBS was influenced by dentinal characteristics in three of the four materials tested.

Adhesiveness↗
PubMed1992

Circadian variation in plasma homovanillic acid level during and after alcohol withdrawal in alcoholic patients.

Alcohol withdrawal symptoms in alcoholics were objectively evaluated and classified into three groups according to the severity of their symptoms, and circadian variation in their plasma homovanillic acid (HVA) concentrations was determined at three different intervals after cessation of drinking. The subjects studied were 19 male alcoholic patients and five age-matched healthy male volunteers. Circadian variation in plasma HVA was compared between each patient group and the control group by two-way ANOVA. In the sympathetic overactivity (SO) group comprising nine patients and in the clouding of sensorium (CS) group comprising five patients, plasma HVA concentrations on the 2nd and 3rd day and on the 6th and 7th day after cessation of drinking were low but recovered almost normal levels on the 21st and 22nd postcessation day. The delirium tremens group (DT) comprising five patients, however, showed significantly higher plasma HVA than the control group except on the 6th and 7th postcessation day. The higher plasma HVA in the DT group indicates that there is some sort of preparatory state whereby dopamine metabolism is involved in the appearance of hallucinations at alcohol withdrawal and can possibly be used as a predictor of otherwise hardly predictable delirium tremens.

Adult↗
PubMed1992

Magnesium supplementation prevents the development of alcohol-induced hypertension.

The effect of chronic alcohol administration on blood pressure was investigated in 7-week-old Wistar rats. Tail-cuff blood pressure was significantly higher in rats who received 15% ethanol in drinking water than in control rats. Intracellular free calcium concentration of lymphocytes was increased, while magnesium concentration of erythrocyte, aorta, and skeletal muscle and erythrocyte ouabain-sensitive 22Na efflux rate constant (Kos) were decreased in alcohol-induced hypertensive rats but not in control rats. Extracellular fluid volume was also increased in alcohol-administered rats. Oral magnesium supplementation (1% MgO in rat chow) attenuated the development of alcohol-induced hypertension accompanied by increased magnesium concentration of erythrocyte, aorta, skeletal muscle, and Kos and decreased intraerythrocyte sodium concentration. Norepinephrine half-life time of the heart and spleen was also increased in magnesium-supplemented rats. Blood pressure significantly correlated positively with intracellular calcium concentration and extracellular fluid volume, negatively with magnesium concentration of erythrocyte, aorta, skeletal muscle, and Kos. These results suggest that increased intracellular calcium, which was partly due to magnesium depletion and suppressed sodium pump activity, and expanded body fluid volume had a possible role in the development of alcohol-induced hypertension. It is also suggested that oral magnesium supplementation had a hypotensive effect on alcohol-induced hypertension possibly through decreased intracellular sodium concentration caused by an activation of sodium pump and decreased sympathetic nervous activity.

Animals↗
PubMed1992

In vivo cyclooxygenase expression in synovial tissues of patients with rheumatoid arthritis and osteoarthritis and rats with adjuvant and streptococcal cell wall arthritis.

Cyclooxygenase (COX), or prostaglandin (PG) H synthase, plays a role in inflammatory diseases, but very limited data exist on the regulation of COX in vivo. We, therefore, studied the in vivo expression of COX in synovia from patients with rheumatoid arthritis (RA) and osteoarthritis (OA), as well as joints of rats with streptococcal cell wall (SCW) and adjuvant arthritis. Extensive and intense intracellular COX immunostaining, which correlated with the extent and intensity of mononuclear cell infiltration, was observed in cells throughout RA synovia. Significantly less or equivocal staining was noted in OA and normal human synovia. Similarly, COX immunostaining was equivocal in the joints of normal and arthritis-resistant F344/N rats. In contrast, high level expression developed rapidly in euthymic female Lewis (LEW/N) rats throughout the hindlimb joints and overlying tissues including skin, preceding or paralleling clinically apparent experimental arthritis. COX was expressed in the joints of athymic LEW.rnu/rnu rats 2-4 d after injection of SCW or adjuvant but was not sustained. Physiological doses of antiinflammatory glucocorticoids, but not progesterone, suppressed both arthritis and COX expression in LEW/N rats. These observations suggest that, in vivo, (a) COX expression is upregulated in inflammatory joint diseases, (b) the level of expression is genetically controlled and is a biochemical correlate of disease severity, (c) sustained high level up-regulation is T cell dependent, and (d) expression is down-regulated by antiinflammatory glucocorticoids.

Animals↗
PubMed1992

Local secretion of corticotropin-releasing hormone in the joints of Lewis rats with inflammatory arthritis.

Corticotropin-releasing hormone (CRH), the principal regulator of the hypothalamic-pituitary-adrenal axis, is also secreted in peripheral inflammatory sites, where it acts as a local proinflammatory agent. Arthritis-susceptible LEW/N rats have profoundly deficient hypothalamic CRH responses to inflammatory stimuli and other stressors. Arthritis-resistant F344/N rats, on the other hand, have a robust increase in hypothalamic CRH in response to the same stimuli. Contrasting with these hypothalamic CRH responses, we now show that CRH expression is markedly increased in the joints and surrounding tissues of LEW/N rats with streptococcal cell wall- and adjuvant-induced arthritis, whereas it is not increased in similarly treated F344/N rats and is only transiently increased in congenitally athymic nude LEW.rnu/rnu rats. Glucocorticoid treatment suppressed, but did not eliminate, CRH immunoreactivity in the joints of LEW/N rats. CRH mRNA was present in inflamed synovia, as well as in spinal cord, and inflamed synovia also expressed specific CRH-binding sites. We compared CRH expression in inflamed joints with another well-characterized proinflammatory neuropeptide, substance P (SP), and found that SP immunoreactivity paralleled that of CRH. In summary, although LEW/N rats have deficient hypothalamic CRH responses to inflammatory stimuli compared with F344/N rats, they express relatively high levels of CRH at the site of inflammation. Analogous to SP, CRH may be delivered to the inflammatory site by peripheral nerves and/or synthesized at the inflammatory site. These data provide further support for the concept that CRH not only triggers the pituitary-adrenal antiinflammatory cascade, but also functions as an antithetically active local mediator of acute and chronic inflammatory arthritis. These data also illustrate the complex interrelationships of the nervous, endocrine, immune, and inflammatory systems.

Animals↗
PubMed1992

The studies of cell damaging and cell growth factors which induce cardiomyopathy.

We demonstrated that phosphatidylinositide-specific phospholipase C (PLC) activity was greater in cardiomyopathic hamster hearts (BIO 14.6 and BIO 53.58) then in hamster controls (F1b). Inositol trisphosphate (IP3) production was markedly greater in both of the cardiomyopathic hamsters, BIO 14.6 and BIO 53.58. We have also determined the sarcoplasmic reticulum (SR) function of heart. Calcium uptake into SR markedly increased in BIO 14.6. On the other hand, it significantly decreased in BIO 53.58 compared with F1b. It is well known that IP3 stimulates calcium release from SR. In BIO 14.6, calcium release from SR stimulated by IP3 increased, but its effect decreased in BIO 53.58 compared with F1b. These results suggest that PI response may produce high intracellular calcium levels in both BIO 14.6 and BIO 53.58 myocytes. In addition, in the BIO 53.58 hamster the sarcoplasmic reticulum deteriorate in function. It was concluded from these results that a prolonged high intracellular calcium level may lead to the death of BIO 53.58 myocytes. The expression of angiotensinogen mRNA was observed in the hamster heart. There was no differences in its expression level between F1b, BIO 14.6 and BIO 53.58. There was no effect of ages on its expression in these hamster hearts. We have also determined the distribution of angiotensinogen in these hamsters. At 4 weeks of age, the immunohistochemical study revealed that angiotensinogen was widely distributed in subendocardium in these hamsters. There was no difference in its distribution between F1b, BIO 14.6 and BIO 53.58. But at 20 weeks old of age its immunoreactivity decreased in BIO 53.58.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensinogen↗
PubMed1992

Phosphatidylinositol and inositolphosphatide metabolism in hypertrophied rat heart.

The accumulation of both Inositol-(1,4,5)-trisphosphate (IP3) and Inositol-(1,3,4,5)-tetrakisphosphate (IP4) after hormonal stimulation has a physiological role, possibly in altering Ca2+ levels in cardiac tissue. However, the accumulation of inositol polyphosphate under pathophysiological conditions has not been studied. In our experiments the metabolism of phatidylinositol and IP3 in cardiac myocytes as investigated. It was shown that basal levels of cytosolic phosphatidylinositol specific phospholipase C (PI-PLC), phosphatidylinositol-(4,5)-bisphosphate specific phospholipase C (PIP2-PLC) activities markedly increased in stroke-prone spontaneously hypertensive rats (SHRSP) with age compared with age matched Wistar Kyoto rats (WKY). IP3 kinase and IP3 phosphatase activities also increased in SHRSP hearts with age. Their activities increased in WKY, but to a lesser extent than in SHRSPs. These data suggest that a PI turnover pathway such as the phosphatidylinositol 4,5-bisphosphate-IP3-Ca2+ pathway or the diacylglyceride-protein kinase C pathway may have an important role in the development of hypertrophy in SHRSP heart.

Animals↗
PubMed1992

Combined effects of diet and cold exposure on insulin responsiveness to glucose and tissue responsiveness to insulin in sheep.

Hyperglycemic clamp and hyperinsulinemic euglycemic clamp techniques were used to investigate effects of diet and cold exposure on insulin responsiveness to glucose and tissue responsiveness and sensitivity to insulin in adult rams. The sheep were fed a high-concentrate diet (80% concentrate and 20% roughage) and a high-roughage diet (20% concentrate and 80% roughage), both 70% above the ME requirement for maintenance, and were exposed to a thermoneutral environment (20 degrees C) and a cold environment (0 degrees C) for 2 wk. The estimated ME intake was greater (P < .01) for the high-concentrate diet than for the high-roughage diet. In the hyperglycemic clamp experiment, the ratio of the plasma insulin increment to the glucose infusion rate (insulin responsiveness to glucose) was lower during cold exposure than in the thermoneutral environment in sheep fed the high-concentrate diet but was unchanged in sheep fed the high-roughage diet. In the hyperinsulinemic euglycemic clamp experiment, the glucose infusion rate (tissue responsiveness to insulin) was higher (P < .01) for the high-concentrate diet than for the high-roughage diet, and it was also higher (P < .01) during cold exposure than in the thermoneutral environment, indicating that tissue responsiveness to insulin was intensified in sheep fed the high-concentrate diet during cold exposure associated with the higher energy intake. These results suggest that both reduced insulin responsiveness and enhanced tissue responsiveness to insulin in sheep exposed to cold were dependent on the type of diet.

Animal Feed↗
PubMed1992

[The effect of aging on observation in hearing in the same individuals over a 5 year period].

The purpose of this study was to investigate the process of changes in hearing of pure tones with aging. Among individuals who had undergone thorough medical examination for the purpose of annual health-checks, 293 males (586 ears) whose hearing level had been examined for five years or more were enrolled in this study. Cases having conductive deafness or known sensori-neural deafness were excluded. Since the most typical change with aging is observed at 8 kHz, the investigation was carried out only on hearing at 8 kHz. Hearing level increasingly declined with advancing age. Hearing distribution for young subjects showed a peak in the normal hearing level range. This peak decreased with aging, and another peak appeared at 50 dB. Investigation of differences in hearing in the individuals over the five years showed that most subjects had a hearing level difference of 0 dB up to 54 years of age. From 55 years old onward, however, the difference was 5 dB. This indicates that gradual deterioration of hearing level with aging occurs most frequently. On the other hand, in some subjects, deafness progressed faster. Thirty-four and a half percent of the subjects had deteriorations of 20 dB or more in a single year during the entire observation period. A deterioration of 20 dB or more was noted in 4% of the young and 8% of the elderly. Such rapid progression of deafness was believed to be involved in formation of the 50 dB peak in the hearing distribution.

Adult↗
PubMed1992

[Influence of environmental temperature (cold exposure) on nasal resistance].

Changes in nasal resistance were examined in 33 healthy subjects in order to investigate the physiological reactions of nasal mucosa to cold exposure. Each examinee was exposed to changes in room temperature from 25 degrees C to 15 degrees C with the same humidity in an artificial atmosphere chamber, regulated by an environmental control unit. Nasal resistance was measured by means of the active-anterior method using a rhinomanometer MPR-2200. The same experiments were repeated on different dates in all 18 subjects. The results can be summarized as follows. 1) The average value of nasal resistance significantly increased after room temperature was decreased from 25 degrees C to 15 degrees C. 2) Patterns of nasal resistance responses to cold exposure were classified into two types. One type was increased nasal resistance after cold exposure and the other was maintenance of resistance despite cold exposure. Each individual manifested a different pattern in experiments carried out on different dates. 3) The nasal resistance value in the chamber at 25 degrees C was significantly higher in winter than in summer, and the increase in nasal resistance in response to cold exposure was significantly larger in summer than in winter. This result was assumed to be due to cold adaptation of the nasal mucosa in winter. 4) Heart rate decreased significantly with cold exposure. However, changes of heart rate in response to cold exposure did not correlate with changes in nasal resistance. No correlation between changes in nasal resistance in response to cold exposure and orthostatic loading, which was carried out after the cold exposure experiment, was detected. 5) A nasal cycle was observed in 7 (14%) of the 33 cases. In 6 of these total nasal resistance was maintained despite cold exposure.

Adult↗
PubMed1992

ES-242-2, -3, -4, -5, -6, -7, and -8, novel bioxanthracenes produced by Verticillium sp., which act on the N-methyl-D-aspartate receptor.

Verticillium sp. SPC-15898 was found to produce novel metabolites, designated ES-242-2-(-)8, which were structurally related to ES-242-1. These compounds were isolated from the culture broth and the physico-chemical and biochemical properties were examined. ES-242-2-(-)8 inhibited [3H]thienyl cyclohexypiperidine ([3H]TCP) binding to rat crude synaptic membranes (CSM) with IC50 values of 0.116, 2.9, ca. 2.9, 25.3, 1.0, 59, 24, and 13 microM, respectively. None of these compounds showed inhibitory effects against the binding of [3H]kainate to its receptor, which is another subtype of the excitatory amino acid receptor.

Animals↗
PubMed1992

ES-242-1, a novel compound from Verticillium sp., binds to a site on N-methyl-D-aspartate receptor that is coupled to the channel domain.

A novel compound, ES-242-1, which binds to a site on N-methyl-D-aspartate (NMDA) receptor that is coupled to the channel domain, was isolated from the culture broth of a fungus, Verticillium sp. SPC-15898. ES-242-1 inhibited the [3H]thienyl cyclohexylpiperidine ([3H]TCP) binding to rat crude synaptic membrane fractions with an IC50 value of 116 nM, but did not inhibit the [3H]kainate binding to its receptor, which is another subtype of the excitatory amino acid receptor.

Animals↗