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C Nakagawa

Publications and source records attributed to C Nakagawa.

At least 19 recordsLinked to original sources
PubMed2006

Preventive effects of CIDR-based protocols on premature ovulation before timed-AI in Ovsynch in cycling beef cows.

Ovsynch is a program developed to synchronize ovulation for timed breeding. In this paper, the authors investigate whether controlled internal drug release (CIDR)-based protocols prevent premature ovulation before timed-artificial insemination (AI) when Ovsynch is started a few days before luteolysis in cycling beef cows. Nine beef cows at 16 days after oestrus were treated with (1) Ovsynch, i.e. gonadotropin releasing hormone (GnRH) analogue on day 0, prostaglandin (PG) F(2alpha) analogue on day 7 and GnRH analogue on day 9 with timed-AI on day 10, (n=3); (2) Ovsynch+CIDR (Ovsynch protocol plus a CIDR for 7 days from day 0, n=3), or (3) oestradiol benzoate (OB)+CIDR+GnRH (OB on day 0 in lieu of the first GnRH treatment, followed by the Ovsynch+CIDR protocol, n=3). In the Ovsynch group (1) plasma progesterone concentrations fell below 0.5 ng/mL earlier (day 5) than in both CIDR-treated groups (2) and (3), where this occurred on day 8. Plasma oestradiol-17beta concentrations peaked on day 8 in the Ovsynch group and on day 9 in both CIDR-treated groups. The dominant follicle ovulated on day 10 in the Ovsynch group and on day 11 in both CIDR-treated groups. Thus, both CIDR-based protocols prevented premature ovulation before timed-AI in Ovsynch when the protocol was started a few days before luteolysis. This reflects the fact that progesterone levels remained high until the beef cattle were treated with PGF(2alpha).

Administration, Intravaginal↗
PubMed2006

Anesthetic management for cesarean section in moyamoya disease: a report of five consecutive cases and a mini-review.

We report five consecutive cases of neuraxial anesthesia for cesarean section in women with moyamoya disease. Either epidural or combined spinal-epidural anesthesia was provided, with adequate sedation using intravenous diazepam and/or opioid(s). Hemodynamic stability and normocapnia were well maintained, except in one patient who exhibited transient hypertension and hypocapnia due to anxiety. None of the parturients suffered from neurological deficit in the intra- or postoperative period, although one patient complained of numbness in her fingers at the end of surgery, but she was not hypotensive or hypocapneic. The neonates were all in good health. The literature is reviewed on the anesthetic management for cesarean section in patients with moyamoya disease.

Adult↗
PubMed2001

Thiazolidinedione derivative improves fat distribution and multiple risk factors in subjects with visceral fat accumulation--double-blind placebo-controlled trial.

BACKGROUND: It has been clarified that visceral fat accumulation leads to atherosclerosis through multiple risk factors such as insulin resistance, glucose intolerance, hyperlipidemia and hypertension. So far, it has been reported that a thaizolidinedione derivative, troglitazone, improves the insulin resistance in subjects with diabetes, glucose intolerance and obesity. However, it has not been reported yet that troglitazone affects fat distribution in subjects concomitant with visceral fat accumulation and multiple risk factors. METHODS: Twenty-nine subjects with visceral fat accumulation who had at least two risk factors including glucose intolerance, hyperlipidemia and hypertension were investigated. They were randomly assigned to receive either 200 or 400 mg per day of troglitazone or placebo for 12 weeks. A 75 g oral glucose tolerance test (OGTT) was performed before and after the treatment for 12 weeks. Fasting plasma glucose, insulin, HbA(1c), total serum cholesterol (T-chol), triglyceride (TG), HDL-cholesterol (HDL-C), and blood pressure, as well as the number of risk factors were measured periodically during the treatment. The change of the abdominal fat distribution was evaluated using computed tomographic scanning (CT scan) at the umbilicus level. RESULTS: After the treatment for 12 weeks, the area under the curve (AUC) of plasma glucose from a 75 g OGTT decreased dose-dependently. HbA(1c) and TG decreased significantly in the high-dose troglitazone group (400 mg per day) compared with the placebo group (P<0.05). Systolic blood pressure was significantly lower in subjects with hypertension in the pooled troglitazone group than in the placebo group (P<0.05). Therefore, the number of risk factors decreased with the troglitazone treatment. The ratio of visceral fat area (VFA) to subcutaneous fat area (SFA) (V/S ratio) decreased in the troglitazone groups due to decreased VFA and increased SFA. CONCLUSION: These results suggest that thiazolidinedione derivative may be a useful drug to improve multiple risk factors by changing the fat distribution in subjects with visceral fat accumulation.

Adipose Tissue↗
PubMed2001

Adrenomedullin suppresses fMLP-induced upregulation of CD11b of human neutrophils.

In this study we investigated the effect of adrenomedullin (AM) on fMLP-mediated activation of human neutrophils. AM partially, but significantly, suppressed fMLP-induced upregulation of CD11b expression. The inhibitory effects of AM upon fMLP-induced upregulation of CD11b expression were completely blocked by CGRP [8-37], a CGRP receptor antagonist. AM significantly increased cAMP content in neutrophils and SQ-22,536, an adenylate cyclase inhibitor, and KT-5720, a PKA inhibitor, significantly blocked the inhibitory effects of AM upon fMLP-induced upregulation of CD11b expression. This study indicates that binding of AM to the CGRP receptor suppresses fMLP-induced upregulation of CD11b expression of human neutrophils by increasing intracellular cAMP levels. AM may play an important role in the regulation of inflammatory processes, especially in the binding of neutrophils to vascular endothelial cells and subsequent neutrophil emigration evident in acute pulmonary inflammation.

Adenine↗
PubMed2000

Cytokine-induced nitric oxide production inhibits mitochondrial energy production and impairs contractile function in rat cardiac myocytes.

OBJECTIVES: The present study examined whether nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) can directly inhibit aerobic energy metabolism and impair cell function in interleukin (IL)-1beta,-stimulated cardiac myocytes. BACKGROUND: Recent reports have indicated that excessive production of NO induced by cytokines can disrupt cellular energy balance through the inhibition of mitochondrial respiration in a variety of cells. However, it is still largely uncertain whether the NO-induced energy depletion affects myocardial contractility. METHODS: Primary cultures of rat neonatal cardiac myocytes were prepared, and NO2-/NO3- (NOx) in the culture media was measured using Griess reagent. RESULTS: Treatment with IL-1beta (10 ng/ml) increased myocyte production of NOx in a time-dependent manner. The myocytes showed a concomitant significant increase in glucose consumption, a marked increase in lactate production, and a significant decrease in cellular ATP (adenosine 5'-triphosphate). These metabolic changes were blocked by co-incubation with N(G)-monomethyl-L-arginine (L-NMMA), an inhibitor of NO synthesis. Sodium nitroprusside (SNP), a NO donor, induced similar metabolic changes in a dose-dependent manner, but 8-bromo-cyclic guanosine 3',5'-monophosphate (8-bromo-cGMP), a cGMP donor, had no effect on these parameters. The activities of the mitochondrial iron-sulfur enzymes, NADH-CoQreductase and succinate-CoQreductase, but not oligomycin-sensitive ATPase, were significantly inhibited in the IL-1beta, or SNP-treated myocytes. Both IL-1beta and SNP significantly elevated maximum diastolic potential, reduced peak calcium current (I(Ca)), and lowered contractility in the myocytes. KT5823, an inhibitor of cGMP-dependent protein kinase, did not block the electrophysiological and contractility effects. CONCLUSIONS: These data suggest that IL-1beta-induced NO production in cardiac myocytes lowers energy production and myocardial contractility through a direct attack on the mitochondria, rather than through cGMP-mediated pathways.

Adenosine Triphosphate↗
PubMed1999

Basic subsite theory assumptions may not be applicable to hydrolysis of cellooligosaccharides by almond beta-glucosidase.

Steady-state kinetic parameters for the hydrolysis of cellooligosaccharides by almond beta-glucosidase were evaluated at pH 5.0 and 25 degrees C in relation to the subsite theory (K. Hiromi, Biochem. Biophys. Res. Commun., 40, 1-6, 1970). The value of k0/Km decreased monotonously with increasing degree of polymerization (DP) of the substrates (DP = 2-6). Also, the Km and k0 values for cellotriose were smaller than those for cellobiose. These DP dependencies differ from those of most amylases and glucosidases studied so far, to which the subsite theory has been successfully applied. The subsite parameters could not be consistently obtained, which suggests that one or both of the two basic assumptions of the subsite theory might not be applicable to the hydrolysis of cellooligosaccharides by the enzyme. That is, the intrinsic rate of the hydrolysis may depend on the DP and/or there may be interaction between subsites for binding the glucose residues of a substrate.

Journal Article↗
PubMed1999

A case of eosinophilic myocarditis complicated by Kimura's disease (eosinophilic hyperplastic lymphogranuloma) and erythroderma.

This report describes a patient with eosinophilic myocarditis complicated by Kimura's disease (eosinophilic hyperplastic lymphogranuloma) and erythroderma. A 50-year-old man presented with a complaint of precordial pain. However, the only abnormal finding on examinatioin was eosinophilia (1617 eosinophils/microl). Three years later, the patient developed chronic eczema, and was diagnosed with erythroderma posteczematosa. One year later, a tumor was detected in the right auricule, and a diagnosis of Kimura's disease was made, based on the biopsy findings. The patient developed progressive dyspnea 6 months later and was found to have cardiomegaly and a depressed left ventricular ejection fraction (17%). A diagnosis of eosinophilic myocarditis was made based on the results of a right ventricular endomyocardial biopsy. The eosinophilic myocarditis and erythrodrema were treated with steroids with improvement of both the eosinophilia and left ventricular function.

Angiolymphoid Hyperplasia with Eosinophilia↗
PubMed1999

Steady-state inhibitory kinetic studies on the ligand binding modes of Aspergillus niger glucoamylase.

Inhibitory activities of 1-deoxynojirimycin and gluconolactone on Aspergillus niger glucoamylase were studied in relation to the subsite structure of the enzyme. Although both of these inhibitors are considered to bind at subsite 1 of the enzyme active site, 1-deoxynojirimycin showed competitive type inhibition but gluconolactone was a mixed type (or noncompetitive type) inhibitor for the hydrolysis of p-nitrophenyl alpha-D-glucoside. The former type of inhibition suggested that the main binding mode of the substrate was productive, but the latter, nonproductive. A possible way of explaining these apparent inconsistent results is to assume that the main binding mode of the substrate is productive and gluconolactone forms a nonproductive ternary complex with the enzyme and the substrate.

1-Deoxynojirimycin↗
PubMed1998

Energy metabolism after ischemic preconditioning in streptozotocin-induced diabetic rat hearts.

OBJECTIVES: The aim of this study was to compare the cardioprotective effects of preconditioning in hearts from streptozotocin-induced diabetic rats with its effects in normal rat hearts. BACKGROUND: The protective effect of ischemic preconditioning against myocardial ischemia may come from improved energy balance. However, it is not known whether preconditioning can also afford protection to diabetic hearts. METHODS: Isolated perfused rat hearts were either subjected (preconditioned group) or not subjected (control group) to preconditioning before 30 min of sustained ischemia and 30 min of reperfusion. Preconditioning was achieved with two cycles of 5 min of ischemia followed by 5 min of reperfusion. RESULTS: In the preconditioned groups of both normal and diabetic rats, left ventricular developed pressure, high energy phosphates, mitochondrial adenosine triphosphatase and adenine nucleotide translocase activities were significantly preserved after ischemia-reperfusion; cumulative creatine kinase release was smaller during reperfusion; and myocardial lactate content was significantly lower after sustained ischemia. However, cumulative creatine kinase release was less in the preconditioned group of diabetic rats than in the preconditioned group of normal rats. Under ischemic conditions, more glycolytic metabolites were produced in the diabetic rats (control group) than in the normal rats, and preconditioning inhibited these metabolic changes to a similar extent in both groups. CONCLUSIONS: The present study demonstrates that in both normal and diabetic rats, preservation of mitochondrial oxidative phosphorylation and inhibition of glycolysis during ischemia can contribute to preconditioning-induced cardioprotection. Furthermore, our data suggest that diabetic myocardium may benefit more from preconditioning than normal myocardium, possibly as a result of the reduced production of glycolytic metabolites during sustained ischemia and the concomitant attenuation of intracellular acidosis.

Adenine Nucleotides↗
PubMed1997

The mechanisms of compound 48/80-induced superoxide generation mediated by A-kinase in rat peritoneal mast cells.

This investigation was undertaken to clarify the mechanisms of superoxide anion (O2-) generation in rat peritoneal mast cells. Compound 48/80, a typical histamine liberator mediated by calcium influx, elicited O2- generation from the mast cells in a dose-dependent fashion. It was demonstrated by immunohistochemical study and Western blot analysis that the mast cells contained the 47-kDa phagocyte oxidase (p47phox) protein, which was one cytosolic component of the NADPH oxidase system. Arachidonic acid stimulated O2- generation in the mast cells, but other unsaturated fatty acids had no effect. On the other hand, 48/80-induced O2- generation was inhibited by phospholipase A2 inhibitors, such as arachidonyl trifluoromethyl ketone and manoalide. Forskolin, isoprenaline, and dibutyryl cyclic AMP inhibited the O2- generation, and KT-5720, a cyclic AMP-dependent protein kinase (A-kinase) inhibitor, markedly enhanced the O2- generation. These findings suggest that O2- is generated by a NADPH oxidase-like enzyme system in mast cells and that this enzyme system is activated by arachidonic acid released by cytosolic phospholipase A2. Thus, it is regulated by the cyclic AMP-A kinase system.

Animals↗
PubMed1997

Myocardial stretch induced by increased left ventricular diastolic pressure preconditions isolated perfused hearts of normotensive and spontaneously hypertensive rats.

OBJECTIVE: The aim of our study was to determine whether myocardial stretch (non-ischemic stress) could precondition isolated perfused hearts of both normotensive Wister-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). METHODS: The perfused hearts in Langendorff mode were subjected to 30 min of global no-flow ischemia followed by 30 min of reperfusion. Left ventricular developed pressure (LVDP) and end-diastolic pressure (LVEDP) were measured. In the control group, LVEDP was set at 10 mmHg. In the stretch group, LVEDP was increased to 30 or 60 mmHg for 5 min before 30 min of ischemia. In the ischemic preconditioning group, the hearts were exposed to two cycles of a 5-min period of ischemia before 30 min of ischemia. Myocardial lactate contents were measured at the baseline and at the end of the 60 mmHg stretch. RESULTS: Hemodynamic parameters of LVDP and LVEDP at 30 min of reperfusion improved in the stretch group (LVEDP of 60 mmHg) and the ischemic preconditioning group. Coronary flow did not decrease during the stretch. Recovery of the coronary flow during reperfusion was better in the stretch and ischemic preconditioning groups. Postischemic contractile function was better in WKY rats than in SHR. Myocardial lactate contents at the end of 60 mmHg stretch were negligible. CONCLUSIONS: Myocardial stretch induced by increasing LVEDP preconditioned isolated perfused hearts of both WKY rats and SHR, via mechanisms not involving myocardial ischemia during stretch.

Animals↗
PubMed1997

[A case of IAHS (infection associated hemophagocytic syndrome) successfully treated with etoposide].

This report details a case of infection associated hemophagocytic syndrome (IAHS). A 20-year-old female was admitted to our hospital with persistent high fever in July, 1994. Physical examination revealed high body temperature (40 degrees C), marked hepatosplenomegaly and no superficial lymph node swelling. Laboratory examination revealed leukopenia and abnormal liver function on admission. Serum ferritin levels were surprisingly elevated. The coagulation tests showed high FDP and D-dimer. Specific viral antibody titers were not elevated such as Epstein-Barr virus or Cytomegalovirus. Bone marrow examination revealed histiocytic hyperplasia with hemophagocytosis, and the histiocytes were well matured. We diagnosed IAHS. Corticosteroids were administered on the 3rd hospital day (methylprednisolone 1 g/day, 3 days), but persistent high fever and laboratory findings did not improve. So we tried etoposide (etoposide 200 mg/day, 5 days) therapy on the 13th hospital day. After administration of etoposide, she failed to recover from severe leukopenia and suffered from meningitis. We administered G-CSF, gamma-globulin and antibiotics for intensive supportive therapy. As the leukocyte count increased, her symptoms and laboratory data improved. There was no hemophagocytosis in her bone marrow before discharge. Recently, etoposide is said to be effective for reactive monocytic proliferation. Administration of etoposide was very effective for IAHS, although corticosteroids, were ineffective.

Adult↗
PubMed1996

Effect of ischemic preconditioning on mitochondrial oxidative phosphorylation and high energy phosphates in rat hearts.

The ability of ischemic preconditioning (IP) to protect the myocardium against prolonged ischemia may derive from improved energy balance. We therefore examined myocardial energy metabolism and mitochondrial oxidative phosphorylation in isolated perfused rat hearts which were either subjected (IP group), or not subjected (control group), to preconditioning prior to 30 min sustained ischemia and 30 min reperfusion. Preconditioning was achieved with two cycles of 5 min ischemia followed by 5 min reperfusion. Recovery of myocardial function was significantly greater, and creatine kinase release was significantly lower, in the IP group. Although ATP hydrolysis during the sustained ischemia remained unchanged in both groups, greater preservation of high energy phosphate (eg. ATP and CP) was observed in the IP group after reperfusion. CP content immediately after preconditioning greatly exceeded pre-ischemic values. Lactate production during the sustained ischemia was significantly lower in the IP group, suggesting a decrease in anaerobic glycolysis and a probable attenuation of intracellular acidosis. Oligomycin-sensitive mitochondrial ATPase activity in the control group was significantly decreased both after the sustained ischemia and the reperfusion, but in the IP group it did not change after the preconditioning, sustained ischemia, or reperfusion. Although atractyloside-inhibitable adenine nucleotide translocase activity was markedly decreased during sustained ischemia in both groups, its activity was significantly higher after reperfusion in the IP group. These data suggest that (1) mitochondrial ATPase contributes only slightly to ATP depletion during sustained ischemia, (2) both the CP overshoot phenomenon and the decrease in anaerobic glycolysis can be attributable to cardioprotection during the sustained ischemia, and (3) the preservation of ATPase and adenine nucleotide translocase activities may be a possible explanation for the restoration of high energy phosphates after sustained ischemia-reperfusion injury in the preconditioned hearts of rats.

Adenosine Triphosphatases↗
PubMed1996

Effects of glibenclamide and nicorandil in post-ischaemic contractile dysfunction of perfused hearts in normotensive and spontaneously hypertensive rats.

OBJECTIVE: We have demonstrated previously that nicorandil, an ATP-sensitive potassium channel opener, improved post-ischaemic contractile dysfunction of perfused hearts in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats dose-dependently. This study aimed to characterize the effect of glibenclamide, an ATP-sensitive potassium channel blocker, and nicorandil in post-ischaemic contractile dysfunction of SHR and WKY rats. METHODS: The perfused hearts were subjected to 30 min of global ischaemia and then 30 min of reperfusion. Administration of 10 or 50 mumol/l glibenclamide or of a combination of glibenclamide and 300 mumol/l nicorandil was performed for 10 min before the ischaemia. The left ventricular developed pressure and end-diastolic pressure were measured. RESULTS: Postischaemic contractile function was better in WKY rats than it was in SHR. Neither glibenclamide nor a combination of glibenclamide and nicorandil influenced the postischaemic contractile function or increased the incidence of reperfusion arrhythmias. The recoveries of coronary flow and heart rate after reperfusion were poor and the incidence of reperfusion arrhythmias was low in SHR. CONCLUSIONS: These results suggest that nicorandil improves postischaemic contractile dysfunction via a mechanism involving ATP-sensitive potassium channel opening both in SHR and in WKY rats. The hypertensive hearts were more susceptible to cardiac reperfusion dysfunction, compared with normal hearts.

Animals↗
PubMed1996

Prurigo nodularis associated with advanced gastric cancer: report of a case.

In a male Japanese patient, prurigo nodularis (PN) appeared in association with gastric cancer. The cutaneous pruriginous lesions dramatically improved soon after total gastrectomy without any treatment for the skin lesions. Peripheral eosinophilia seen before the operation also rapidly disappeared. These data suggest that some cytokines involved in gastric cancer might have played an important role in the development of PN in our patient.

Adenocarcinoma↗