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Biomedical subjects

H Hosokawa

Publications and source records attributed to H Hosokawa.

At least 37 records · Page 2Linked to original sources
PubMed1999

Effects of adjunctive balloon angioplasty after intravascular ultrasound-guided optimal directional coronary atherectomy: the result of Adjunctive Balloon Angioplasty After Coronary Atherectomy Study (ABACAS).

OBJECTIVES: This study was conducted to evaluate: 1) the effect of adjunctive percutaneous transluminal coronary angioplasty (PTCA) after directional coronary atherectomy (DCA) compared with stand-alone DCA, and 2) the outcome of intravascular ultrasound (IVUS)-guided aggressive DCA. BACKGROUND: It has been shown that optimal angiographic results after coronary interventions are associated with a lower incidence ofrestenosis. Adjunctive PTCA after DCA improves the acute angiographic outcome; however, long-term benefits of adjunctive PTCA have not been established. METHODS: Out of 225 patients who underwent IVUS-guided DCA, angiographically optimal debulking was achieved in 214 patients, then theywere randomized to either no further treatment or to added PTCA. RESULTS: Postprocedural quantitative angiographic analysis demonstrated an improved minimum luminal diameter (2.88 +/- 0.48 vs. 2.6 +/- 0.51 mm; p = 0.006) and a less residual stenosis (10.8% vs.15%; p = 0.009) in the adjunctive PTCA group. Quantitative ultrasound analysis showed a larger minimum luminal diameter (3.26 +/- 0.48 vs. 3.04 +/- 0.5 mm; p < 0.001) and lower residual plaque mass in the adjunctive PTCA group (42.6% vs. 45.6%; p < 0.001). Despite the improved acute findings in the adjunctive PTCA group, six-month angiographic and clinical results were not different. The restenosis rate (adjunctive PTCA 23.6%, DCA alone 19.6%; p = ns) and target lesion revascularization rate (20.6% vs. 15.2%; p = ns) did not differ between the groups. CONCLUSIONS: With IVUS guidance, aggressive DCA can safely achieve optimal angiographic results with low residual plaque mass, and this was associated with a low restenosis rate. Although adjunctive PTCA after optimal DCA improved the acute quantitative coronary angiography and quantitative coronary ultrasonography outcomes, its benefit was not maintained at six months.

Aged↗
PubMed1999

Evidence for a potential role for HDL as an important source of cholesterol in human adrenocortical tumors via the CLA-1 pathway.

CLA-1, a human homologue of rodent scavenger receptor class B1 (SR-B1), has been identified as a receptor for high density lipoprotein (HDL) and is highly expressed in the adrenal gland. Several studies have indicated that HDL might be a source of cholesterol for steroidogenesis in the adrenal gland. In this study, we show that ACTH and its second messenger cAMP stimulated CLA-1 protein expression in a human adrenocortical cell line. We also determined whether CLA-1 plays an important role in steroidogenesis by investigating CLA-1 expression levels in various adrenal tumors including the adenomas of Cushing's and Conn's syndrome. Western blot analysis showed that CLA-1 expression was much higher in the tumors of Cushing's syndrome than in non-tumor lesions of Conn's syndrome and pheochromocytoma. We were able to detect a strong CLA-1 signal in tumors of Conn's syndrome, too. On the other hand, much less CLA-1 expression was detected in Cushing's adenoma adjacent adrenal glands. The immunohistochemical analysis showed that CLA-1 was expressed in the outer region of the adrenal cortex mainly in plasma membranes of the cortical cells but not in the medulla. These findings demonstrated for the first time that ACTH increased CLA-1 protein in cultured human adrenocortical cells, and that cortisol- and aldosterone-secreting adenomas had high CLA-1 proteins in their cell surfaces.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1999

Increased hyperkinesis in noninfarcted areas during short-term follow-up in patients with first anterior acute myocardial infarction treated by direct percutaneous transluminal coronary angioplasty.

The time course and clinical significance of hyperkinetic wall motion (HWM) in a noninfarcted area in direct percutaneous transluminal coronary angioplasty (PTCA) has not been clearly demonstrated in patients with acute myocardial infarction (AMI). The objectives of this study were to examine the change in HWM during one-month follow-up after direct PTCA and determine its impact on the recovery of global left ventricular function. A total of 61 patients with first anteroseptal AMI and one vessel disease were evaluated. The paired left ventriculograms in the 30 degrees right anterior oblique view taken both at baseline and follow-up were analyzed by the centerline and area length methods. The severity of hypokinesis was expressed by mean regional wall motion (standard deviation/chord) in most hypocontractile 50% of chords respondable to left anterior descending coronary artery area and HWM by mean regional wall motion in most hypercontractile 50% of chords of noninfarcted area. HWM increased from 0.18 +/- 1.07 to 0.48 +/- 1.30 (p = 0.0608). The delta global ejection fraction (global ejection fraction at follow-up minus global ejection fraction at baseline) was correlated with both delta infarcted wall motion (infarcted wall motion at follow-up minus infarcted wall motion at baseline) and delta HWM (HWM at follow-up minus HWM at baseline) (r = 0.576, p < 0.0001, r= 0.383, p = 0.0036, respectively) during follow-up. Further, the delta global ejection fraction showed better correlation with delta (HWM + infarcted wall motion) [(HWM plus infarcted wall motion at follow-up) minus (HWM plus infarcted wall motion at baseline)] (r= 0.593, p < 0.0001). Direct PTCA resulted in the enhancement of HWVM, which contributed to the increase in the global ejection fraction with the recovery of infarcted wall motion.

Aged↗
PubMed1999

[The effect of 5-HT 2 antagonist for urinary frequency symptom on diabetes mellitus patients].

17 cases of patients with diabetes mellitus who had urinary frequency symptom for which anti-cholinergic agents proved ineffective were given Sarpogrelate Hydrochloride (Anplag), a selective 5-HT 2 receptor antagonist. Efficacy was judged using IPSS and QOL scores after 2 weeks medications, these showed that all cases had improved their urinary frequency during the days as well as the night. This was especially true for the QOL score. One time urinary volume markedly increased, but there was no statistical significance after medication in maximum flow rate and residual urine. At the same time, a separate group of 14 mainly BPH cases did not improve entirely. It is believed that reaction in the detrusor muscle with hyperreflexia of diabetes mellitus patients can reach 5-HT, and its reaction is believed to reach via the 5-HT 2 receptor. This paper is a first clinical report of making use of 5-HT 2 antagonist as hyperactive detrusor on diabetes mellitus patients.

Adult↗
PubMed1997

Cloning and characterization of a brain-specific cationic amino acid transporter.

rCAT3 (rat cationic amino acid transporter 3), a cDNA that encodes a novel member of the murine CAT family was isolated. The protein encoded by rCAT3 contained 619 amino acids, 53-58% of which were identical with those of the murine CAT family proteins previously described (mouse CAT1, CAT2a, CAT2b, and rat CAT1). Transient expression of rCAT3 and L-[14C]arginine incorporation experiments in COS7 cells verified a high affinity system y+ transporter activity of rCAT3. First, rCAT3-mediated L-[14C]arginine incorporation was time-dependent and saturable with half-saturation constant (Km) values of 103 +/- 12 microM (mean +/- S.E., n = 3). Second, the incorporation was specific for cationic amino acids as evidenced from the inhibition by L-arginine, L-lysine, and L-ornithine. Third, neither sodium nor chloride ions in the extracellular medium were required for the activity. Fourth, the incorporation was inhibited by high potassium-induced membrane depolarization. On Northern blot using RNAs from various rat tissues, the expression of rCAT3 mRNA was restricted to the brain. These results indicated a role of rCAT3 in the system y+ transporter activity in the nervous tissue.

Amino Acid Sequence↗
PubMed1997

Beta-cell hypersensitivity to glucose following 24-h exposure of rat islets to fatty acids.

Prolonged exposure of islets to fatty acids results in a lowered glucose set-point for insulin secretion. We examined the mechanism in islets cultured for 24 h with 0.25 mmol/l palmitate. As expected, insulin secretion at 2.8 and 8.3 mmol/l glucose was increased in the palmitate-treated islets as opposed to no change at 27.7 mmol/l glucose. Co-culturing with 0.05 microgram/ml Triacsin C, an inhibitor of long chain acyl-CoA synthetase, blocked this effect. Glucose utilization and oxidation showed the same pattern as insulin secretion, with the step-up for both measurements being fully manifest at 2.8 mmol/l glucose. Glucokinase Km and Vmax measured in islet extracts were unaffected by the palmitate. In contrast, hexokinase Vmax was increased by 25-35% in both the cytoplasmic and mitochondrial-bound pools. Our data suggest prolonged exposure to fatty acids increased beta-cell hexokinase activity, thereby modifying the kinetics of glucose entry into the metabolic pathway and glucose-induced insulin secretion. The cellular mediator is likely an increased level of long chain fatty acyl-CoA esters.

Animals↗
PubMed1997

Variability in frame by frame analysis of left ventricular wall motion from contrast angiograms.

BACKGROUND: Measurement of the timing of left ventricular (LV) wall motion, of asynchrony, and of diastolic function from contrast angiograms requires delineation of the endocardial border frame by frame through the cardiac cycle. This study was performed to determine the magnitude of intraobserver and interobserver variability in manual border tracing, and to measure the impact of this variability on the derived functional parameters. METHODS: The contrast ventriculograms of 25 patients with coronary artery disease (CAD) or with normal coronary arteries were analyzed frame by frame, by two observers or twice by the same observer. Motion was measured using the centerline method at each twelfth of systole and of diastole. Variability was calculated as the absolute difference between repeated measurements of: wall motion, asynchrony, and the time at which each region of the LV reached 10%, 50%, and 100% of peak contraction, and 50% of filling. RESULTS: Intraobserver and interobserver variability in wall motion were similar, and varied with time in the cycle, and with location on the LV contour. Variability was highest at end systole, when it averaged 8% of the normal mean for wall motion. Variability in timing was highest at peak contraction; however, the variability in measuring asynchrony averaged only 18 msec. CONCLUSION: Analysis of the magnitude and synchrony of regional LV wall motion through the cardiac cycle from contrast ventriculograms can be performed with reproducibility comparable to that at end systole.

Aged↗
PubMed1997

Heart disease deaths on death certificates re-evaluated by clinical records in a Japanese city.

In order to estimate the number of deaths from ischemic heart disease (IHD) in a Japanese city, we reevaluated heart disease deaths among residents aged 25-74 years by examining their clinical records. During the 2-year period from 1987 to 1988, 271 deaths among this population were attributed to heart disease. The recorded underlying cause of death was IHD in 96 cases, heart failure in 123 cases, and other heart disease in 52 cases. Re-evaluation of the cause of death yielded 57 cases of acute myocardial infarction (AMI), 85 cases of sudden death, 37 cases of heart disease other than IHD, and 63 cases of non-heart disease. In the remaining cases, there was insufficient information for evaluation. According to some autopsy studies, about 50% of sudden deaths are due to IHD. Thus, 50% of the number of sudden death cases may be added to the total number of IHD deaths. Accordingly, the total number of IHD deaths may have been 100, ie, 57 cases of AMI plus 43 cases of sudden death. The difference between the number of IHD deaths after re-evaluation and the number for which IHD was recorded as the underlying cause was small, with the former only 4% higher than the latter. The number of false-positives was equal to the number of false-negatives, and hence the number of IHD deaths recorded in this area seems to be close to the actual figure. We speculate that more accurate death certification will result in a decrease in the total number of deaths attributable to heart disease, as in 23% of deaths attributed to heart disease the underlying cause of death was not in fact heart disease.

Adult↗
PubMed1997

The effect of somatostatin analogue on glucose homeostasis in conscious dogs.

Our aim was to clarify the effect of a somatostatin analogue (octreotide) on glucose flux in conscious dogs. We monitored the effects with catheters in the portal vein, hepatic vein and femoral artery and Doppler flow probes on the portal vein and hepatic artery before and after oral glucose administration. A significant increase of portal vein plasma flow after oral glucose was completely suppressed by both 4 and 1 micrograms/kg octreotide. All doses of octreotide (4, 1 and 0.1 microgram/kg) suppressed the glucose-induced increment of arterial glucose by dose response. Only 4 micrograms/kg of octreotide slightly but significantly suppressed hepatic glucose output. Marked suppression and delayed glucose absorption by the intestine was observed after 4 micrograms/kg of octreotide. One and 0.1 microgram/kg octreotide also suppressed glucose absorption without delayed absorption. Total amounts of absorbed glucose during 3h after oral glucose were 24 +/- 11% with 4 micrograms/kg of octreotide, 37 +/- 16% with 1 microgram/kg of octreotide, and 48 +/- 8% with 0.1 microgram/ kg of octreotide, all of which were significantly less than that of the control (73 +/- 8%). Using 4 micrograms/kg of octreotide treatment, the liver took up only 5 +/- 4% of the absorbed glucose, while the liver took up 35 +/- 6% and 43 +/- 9% of the absorbed glucose with 1 and 0.1 microgram/kg of octreotide. These latter values were similar to that of the control value of 34 +/- 4%. In conclusion, we found that octreotide administered before oral glucose had a remarkable stabilizing effect on postprandial glycemic surges. Both the direct inhibitory effect of octreotide on portal vein plasma flow and impaired glucose absorption would contribute to this decreased postprandial hyperglycemia, while its suppressive effect on other hormones, such as insulin and glucagon, did not seem to influence the reduction of hyperglycemia.

Animals↗
PubMed1997

Discitis, infectious arthritis, and bacterial meningitis in a patient with pancreatic diabetes.

A 63-year-old woman with pancreatic diabetes after a total pancreatectomy and splenectomy developed discitis of the L2/3 intervertebral disk. Rapidly she also developed infectious arthritis of the left knee joint and bacterial meningitis. Aspirate from the left knee contained Enterococcus faecalis. The diagnosis of discitis is generally difficult in the initial period of disease, and patients with diabetes or splenectomy are susceptible to rapid progression of the infection. Early diagnosis of discitis using magnetic resonance imaging of the spine and treatment with antibiotics might have altered her clinical course.

Arthritis, Infectious↗
PubMed1996

Mechanism of impaired glucose-potentiated insulin secretion in diabetic 90% pancreatectomy rats. Study using glucagonlike peptide-1 (7-37).

Chronic hyperglycemia causes a near-total disappearance of glucose-induced insulin secretion. To determine if glucose potentiation of nonglucose secretagogues is impaired, insulin responses to 10(-9) M glucagonlike peptide-1 (GLP-1) (7-37) were measured at 2.8, 8.3, and 16.7 mM glucose with the in vitro perfused pancreas in rats 4-6 wk after 90% pancreatectomy (Px) and sham-operated controls. In the controls, insulin output to GLP-1 was > 100-fold greater at 16.7 mM glucose versus 2.8 mM glucose. In contrast, the increase was less than threefold in Px, reaching an insulin response at 16.7 mM glucose that was 10 +/- 2% of the controls, well below the predicted 35-40% fractional beta-cell mass in these rats. Px and control rats then underwent a 40-h fast followed by pancreas perfusion using a protocol of 20 min at 16.7 mM glucose followed by 15 min at 16.7 mM glucose/10(-9) M GLP-1. In control rats, fasting suppressed insulin release to high glucose (by 90%) and to GLP-1 (by 60%) without changing the pancreatic insulin content. In contrast, in Px the insulin response to GLP-1 tripled in association with a threefold increase of the insulin content, both now being twice normal when stratified for the fractional beta-cell mass. The mechanism of the increased pancreas insulin content was investigated by assessing islet glucose metabolism and proinsulin biosynthesis. In controls with fasting, both fell 30-50%. In Px, the degree of suppression with fasting was similar, but the attained levels both exceeded those of the controls because of higher baseline (nonfasted) values. In summary, chronic hyperglycemia is associated with a fasting-induced paradoxical increase in glucose-potentiated insulin secretion. In Px rats, the mechanism is an increase in the beta-cell insulin stores, which suggests a causative role for a lowered beta-cell insulin content in the impaired glucose-potentiation of insulin secretion.

Animals↗
PubMed1995

Attenuation of acetylcholine-induced vasoconstriction by L-arginine is related to the progression of atherosclerosis.

To determine if L-arginine, a precursor of the endothelium-derived relaxing factor, restores endothelium-dependent dilation in human coronary arteries, we studied 21 patients in whom the lumina of the coronary arteries were angiographically smooth or slightly irregular and in whom there was a constrictor response to acetylcholine (ACh) in the left anterior descending coronary artery or the circumflex coronary artery. We examined the response to intracoronary ACh before and after infusion of L-arginine by measuring coronary diameter with quantitative angiography. Intracoronary injection of ACh produced vasoconstriction in the majority of patients with coronary risk factors. The percentage diameter change in smooth segments in patients with entirely smooth coronary arteries (group 1, n = 44) from baseline was -20.7% +/- 17.4%. During systemic infusion of L-arginine, the constrictor response to ACh in these segments was significantly attenuated (-2.2% +/- 15.1% from baseline, p < 0.01, ACh alone vs ACh during L-arginine infusion). In smooth segments in patients with luminal irregularities in the other coronary arteries (group 2, n = 19), ACh produced a marked constriction (-32.5% +/- 22.5% from baseline, p < 0.05, group 1 vs group 2). Infusion of L-arginine also attenuated ACh-induced vasoconstriction in these segments (-9.7% +/- 14.1% from baseline, p < 0.01, ACh vs ACh during L-arginine infusion). In segments with irregular lumina (group 3, n = 26), ACh produced more prominent vasoconstriction. The percentage diameter change was -40.9% +/- 26.5% from baseline (p < 0.01 vs group 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗
PubMed1995

Myocardial microdialysis of salicylic acid to detect hydroxyl radical generation during ischemia.

We examined in vivo monitoring of hydroxyl radical (.OH) generation during myocardial ischemia for 30 min by occluding the left anterior descending (LAD) in dog heart using a microdialysis technique. The hydroxyl radical reacts with salicylate and generates 2,3- and 2,5-dihydroxybenzoic acids (DHBA) which can be measured electrochemically in picomole quantity by a high pressure liquid chromatography-electrochemical (HPLC-EC) procedure. When the premature ventricular contraction (PVC) occurred at almost 25 sec intervals, marked elevation of the levels of 2,3- and 2,5-DHBA was observed in the heart dialysate of 30-min ischemia. This study demonstrated the generation of .OH in the canine heart subjected to 30-min ischemic insult.

Animals↗