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Biomedical subjects

H Yoshida

Publications and source records attributed to H Yoshida.

At least 559 records · Page 31Linked to original sources
PubMed1999

Association of radial bone mineral density with CA repeat polymorphism at the interleukin 6 locus in postmenopausal Japanese women.

Twin studies have shown strong correlations between bone mass and genetic factors. Some of the genes involved could regulate bone metabolism and bone formation and resorption, all processes that determine bone mass. One candidate gene, interleukin 6 (IL-6), has been implicated in the pathogenesis of bone loss because it stimulates osteoclasts. We investigated a possible association between the CA repeat polymorphism at the IL-6 gene locus and the bone mineral density (BMD) of radial bone in 472 postmenopausal Japanese women. Genotypes were classified into six groups according to the number of CA repeats present, from 13 to 18. BMD was expressed as adjusted BMD, which was the body mass index (BMI)- and age-adjusted average BMD. The 73 women who possessed an A1 allele (134 bp, containing 18 repeats of CA) had significantly lower adjusted BMD than those participants (n = 399) who did not carry an allele of that size (mean +/- SD values, 0.294 +/- 0.064 vs 0.312 +/- 0.061 g/cm2; P = 0.0221). This result suggests that genetic variation at the IL-6 gene locus is associated with some determinants of BMD in postmenopausal women.

Adenine Nucleotides↗
PubMed1999

Differential effects of enalapril and nitrendipine on the fibrinolytic system in essential hypertension.

BACKGROUND: Impaired fibrinolysis is associated with thromboembolic complications in hypertensive patients. It has been reported that cardiovascular morbidity and mortality rates are high even after lowering the elevated blood pressure with antihypertensive drugs. The aim of this study was to assess the effect of clinically used dosages of enalapril and nitrendipine on the fibrinolytic system. METHODS: Tissue plasminogen activator antigen (tPA) and tissue plasminogen activator inhibitor-1 (PAI-1) activity were measured in 20 normotensive male subjects and 46 male patients with mild essential hypertension divided into 2 groups (22 patients treated with 5 to 10 mg enalapril once a day and 24 treated with 5 to 10 mg nitrendipine once a day) before and 3 months after drug administration. Plasma renin activity and norepinephrine concentration were also measured. RESULTS: There were no significant differences in basal characteristics between the 2 hypertensive groups. In both hypertensive groups, blood pressure was significantly reduced to a similar level after drug treatment. In the 2 hypertensive groups, plasma renin activity significantly increased after drug treatment; however, there were no significant changes in norepinephrine concentration. Before drug treatment, the 2 hypertensive groups had significantly higher tPA and higher PAI-1 activity than the normotensive subjects. In the enalapril group, there was no significant change in tPA although PAI-1 activity significantly decreased after drug treatment. In the nitrendipine group, there was no significant change in tPA although PAI-1 activity significantly increased after drug treatment. CONCLUSION: Thus enalapril improved impaired fibrinolysis but nitrendipine further aggravated fibrinolysis in essential hypertension. Considering the effect of antihypertensive drugs on the fibrinolytic system, more effective and beneficial treatment of hypertensives, especially at a high risk for thrombus formation might be selected.

Administration, Oral↗
PubMed1999

Effects of short-acting and long-acting loop diuretics on heart rate variability in patients with chronic compensated congestive heart failure.

BACKGROUND: We investigated the effects of a short-acting loop diuretic (furosemide) and a long-acting loop diuretic (azosemide) on heart rate variability, fluid balance, and neurohormonal responses in patients with mild to moderate chronic congestive heart failure. METHODS: Nineteen patients with mild to moderate chronic congestive heart failure received furosemide (40 to 60 mg/day) or azosemide (60 to 90 mg/day) for 5 days in a crossover manner. We performed time-domain and frequency-domain analyses of 24-hour Holter electrocardiographic recordings to assess heart rate variability. RESULTS: The 24-hour urinary sodium excretion was similar during the furosemide and azosemide treatment periods but was significantly greater in the first 2 hours after drug administration during furosemide treatment. Plasma renin activity and the hematocrit level increased and high-frequency power significantly decreased 2 hours after the administration of furosemide only. The standard deviation of all normal R-R intervals and the root mean square of successive differences in the R-R interval were lower with furosemide than with azosemide (P <.05). CONCLUSIONS: Furosemide, a short-acting loop diuretic, has a greater influence on heart rate variability and fluid balance than azosemide, a long-acting loop diuretic, in patients with mild to moderate chronic congestive heart failure.

Blood Pressure↗
PubMed1999

Determination of potassium flux activity of viable human erythrocytes by measuring the release-influx ratio.

A simple and convenient method to determine the K+-flux activity of viable human erythrocytes was developed. Erythrocyte suspensions were incubated at 4 degrees C for 24 h to induce K+-release (deltaKr) and then at 37 degrees C for 3 h to influx K+ into erythrocytes (deltaKi). A straight-line relationship between K+ release-influx ratio and ouabain-induced K+-efflux from erythrocytes indicated that deltaKi/deltaKr ratio or the K+-flux activity was reflected predominantly by Na+/K+-exchanging ATPase activity. Using this method, K+-flux activity of erythrocytes in the young and the aged subjects was measured. The mean deltaKi/deltaKr ratio of the aged subjects was decreased significantly. This method of measuring deltaKi/deltaKr ratio is useful for the evaluation of K+-flux activity of viable erythrocytes.

Adolescent↗
PubMed1999

Effects of clarithromycin on the metabolism of omeprazole in relation to CYP2C19 genotype status in humans.

BACKGROUND AND PURPOSE: A triple therapy with omeprazole, amoxicillin (INN, amoxicilline), and clarithromycin is widely used for the eradication of Helicobacter pylori. Omeprazole and clarithromycin are metabolized by CYP2C19 and CYP3A4. This study aimed to elucidate whether clarithromycin affects the metabolism of omeprazole. METHODS: After administration of placebo or 400 mg clarithromycin twice a day for 3 days, 20 mg omeprazole and placebo or 400 mg clarithromycin were administered to 21 healthy volunteers. Plasma concentrations of omeprazole and clarithromycin and their metabolites were determined before and 1, 2, 3, 5, 7, 10, and 24 hours after dosing. CYP2C19 genotype status was determined by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. RESULTS: Subjects were classified into three groups on the basis of PCR-RFLP analyses for CYP2C19: homozygous extensive metabolizer group (n = 6), heterozygous extensive metabolizer group (n = 11), and poor metabolizer group (n = 4). Mean area under the plasma concentration-time curves from 0 to 24 hours (AUC) of omeprazole in the homozygous extensive metabolizer, heterozygous extensive metabolizer, and poor metabolizer groups were significantly increased by clarithromycin from 383.9 to 813.1, from 1001.9 to 2110.4, and from 5589.7 to 13098.6 ng x h/mL, respectively. There were significant differences in the mean AUC values of clarithromycin among the three groups. CONCLUSION: Clarithromycin inhibits the metabolism of omeprazole. Drug interaction between clarithromycin and omeprazole may underlie high eradication rates achieved by triple therapy with omeprazole, amoxicillin, and clarithromycin.

Adult↗
PubMed1999

Sclerotherapy plus ligation versus ligation for the treatment of esophageal varices: a prospective randomized study.

BACKGROUND: We devised a new combined method of endoscopic variceal ligation and injection sclerotherapy, namely, endoscopic scleroligation, for the treatment of esophageal varices. The aim of this prospective randomized trial was to compare endoscopic scleroligation with endoscopic variceal ligation alone with regard to efficacy, complications, variceal recurrence, and survival. METHODS: Fifty-one patients with cirrhosis and esophageal varices were randomly assigned to be treated by endoscopic scleroligation (n = 25) or endoscopic variceal ligation (n = 26). In the initial session in the endoscopic scleroligation group, endoscopic injection sclerotherapy was performed with injection of 5% ethanolamine oleate around the lower esophagus to obliterate the feeding veins. This was followed by endoscopic variceal ligation from the injection site to the most orad varix. In subsequent sessions, endoscopic injection sclerotherapy was performed with 1% polidocanol. In the endoscopic variceal ligation group, that procedure was performed in all treatment sessions. RESULTS: Both methods were equally effective in achieving complete eradication of esophageal varices. Among the cases in which complete eradication was achieved, the 1- and 3-year cumulative recurrence rates in the endoscopic scleroligation group (9.5%, 22.1%) were significantly lower than those in the endoscopic variceal ligation group (61.9%, 72.2%) (p < 0.01). The survival rates and incidences of treatment-related complications have been similar among patients treated by both methods. CONCLUSIONS: Endoscopic scleroligation is superior to endoscopic variceal ligation in preventing variceal recurrence.

Aged↗
PubMed1999

Washout of small stones in the bile duct by saline infusion using a side-holed balloon catheter in patients undergoing endoscopic papillary balloon dilation.

BACKGROUND: Complete bile duct clearance of stones should be achieved in patients managed with endoscopic papillary balloon dilation. However, complete retrieval of small stones or tiny fragments sometimes proves difficult using conventional devices. METHODS: We attempted the removal of fine stone fragments by saline infusion using a specially designed retrieval balloon catheter with a blind tip and a side hole located proximal to the balloon in 14 patients. RESULTS: Using this technique, bile duct clearance was achieved in a single attempt in 13 of 14 patients; 2 attempts were required in 1 patient. Cholecystitis occurred in 2 patients with gallstones in situ after the procedure. CONCLUSIONS: Saline washout using a side-holed retrieval balloon catheter effectively cleans stones and stone fragments from the bile duct in patients treated with endoscopic papillary balloon dilation.

Aged↗
PubMed1999

Nonoperative management of blunt pancreatic injury in childhood.

PURPOSE: Nonoperative management for blunt pancreatic injury in children was performed between 1977 and 1998. The efficiency and safety of nonoperative management was examined. METHODS: Pancreatic injury was diagnosed in 20 children. The surgical indication was determined by hemodynamic instability and the management of associated injuries. Children without surgical indications were treated initially by nonoperative management. RESULTS: Nineteen of 20 children were treated initially nonoperatively, and 18 of the 19 survived. Surgical exploration was performed in only 1 child with perforation of the duodenum and bile duct. One child died of complications of total parenteral nutrition. Ultrasound scan and computed tomography scan showed pancreatic contusion in 9, laceration in 6, and injury of the main pancreatic duct (MPD) in 5. Pseudocysts were detected in 10 (5 laceration and 5 MPD injury). Pseudocysts smaller than 10 cm disappeared after nonoperative management, and those larger than 10 cm required operative management. Rupture of pseudocysts occurred in 2 children by rotating the upper torso. CONCLUSIONS: Nonoperative management of pancreatic injuries is effective in children, although careful management is required to avoid complications. Pseudocysts smaller than 10 cm were treated successfully by nonoperative management, and those larger than 10 cm required surgical management.

Child↗
PubMed1999

Comparison of vasodilator potency of adrenomedulling and proadrenomedullin N-terminal 20 peptide in human.

Adrenomedullin (ADM) and proadrenomedullin N-terminal peptide (PAMP), both of which are derived from preproadrenomedullin, are reported to have a potent hypotensive effect in animals. However, no data are available concerning the vasodilatory potency of PAMP or comparing this potency to that of ADM in human vasculature. We examined the effects of intra-arterial infusion of graded doses of ADM (1.25, 2.5, 5.0 and 7.5 pmol/min per 100 ml of tissue) and PAMP (125, 250, 500, 750 and 1000 pmol/min per 100 ml of tissue) on total forearm blood flow and forearm skin blood flow in 11 healthy subjects. ADM increased total forearm blood flow from 2.9 +/- 0.4 to 8.6 +/- 1.1 ml/min per 100 ml (p < 0.01), and skin blood flow from 0.07 +/- 0.02 to 0.14 +/- 0.03 volts (p < 0.01). In contrast to this potent vasodilatory effect, a significant rise in forearm skeletal blood flow was seen only in response to the maximum dose of PAMP (from 2.7 +/- 0.5 to 5.3 +/- 1.0 ml/min per 100 ml; p < 0.01). In addition, PAMP had no significant vasoactive effect on skin blood flow (from 0.06 +/- 0.02 to 0.09 +/- 0.03 volts; NS). In conclusion, the skeletal muscle vasodilator potency of PAMP is less than one hundredth of that of ADM in human forearm. Given its weak dilator potency, it seems unlikely that PAMP alone could significantly regulate resistance vessel tone as a circulating hormone in humans.

Adrenomedullin↗
PubMed1999

Protective effects of hochu-ekki-to, a Chinese traditional herbal medicine against murine cytomegalovirus infection.

The innate immunity against murine cytomegalovirus (MCMV) at the early phase of infection is mediated by NK cells and macrophages. We studied the effects of hochu-ekki-to (HET), a traditional Chinese herbal medicine, on the regulation of innate immunity mediated by NK cells and macrophages. We found the oral administration of HET to increase both the number of leukocytes in the spleen and liver and the splenic NK cell cytotoxicity associated with the increased induction of serum IFN-alpha/beta after an MCMV infection but it had no effect on liver NK cells. However, no differences were found in the serum IL-12, IFN-gamma, TNF-alpha and nitric oxide (NO) production in the culture of macrophages between the HET- and PBS-treated mice on day 2 after MCMV infection. In addition, HET-treated splenic and peritoneal macrophages were found to show a higher intrinsic resistance against in vitro MCMV infection than that of PBS-treated mice. Therefore, the HET-induced effects on NK cells and macrophages selectively reduced the viral load in the spleen but not in the liver at an early phase of MCMV infection. HET may thus be useful in the treatment of human cytomegalovirus infection which commonly occurs in HIV-infected AIDS patients.

3T3 Cells↗
PubMed1999

Effect of pituitary microsurgery on acromegaly complicated nephrotic syndrome with focal segmental glomerulosclerosis: report of a rare clinical case.

A case of nephrotic syndrome complicated by acromegaly is presented. The first renal biopsy specimen showed minor glomerular abnormalities with glomerular hypertrophy, corresponding with minimal change nephrotic syndrome. Corticosteroid therapy led to a partial remission, followed by frequent relapses after reduction of the drug. A diagnosis of atypical focal segmental glomerulosclerosis (FSGS) was made based on the second renal biopsy results 6 months after the first. We combined steroid therapy with the administration of an anticoagulant, cytotoxic agents, angiotensin-converting enzyme inhibitor, and low-density lipoprotein adsorption. Except for the angiotensin-converting enzyme inhibitor, these medications were not effective in terms of allowing a reduction in the high dosage of steroid, which in turn threatened progressive osteoporosis and lumbar vertebrae fracture. Administering the steroid at a moderate dosage, treatment was focused on the complicating acromegaly from pituitary microadenoma. Subcutaneous injections of octreotide acetate, a somatostatin analogue, reduced proteinuria and increased urine volume. Subsequent transsphenoidal microsurgery of the adenoma resulted in the normalization of the elevated creatinine clearance and the further reduction in steroid dosage while maintaining a remission state. This is the first reported clinical case with acromegaly followed by FSGS, and it is suggested that hypersecretion of growth hormone participates in the development and progression of glomerular disease.

Acromegaly↗
PubMed1999

Ultrasonographic criteria for diagnosis of cervical lymph node metastasis of squamous cell carcinoma in the oral and maxillofacial region.

PURPOSE: This retrospective study was done to establish an objective criterion for sonographic diagnosis of cervical lymph node metastasis of squamous cell carcinoma in the oral and maxillofacial region. PATIENTS AND METHODS: A quantitative criterion for differentiating metastatic from nonmetastatic nodes was statistically calculated using logistic regression analysis of 106 cervical lymph nodes in 41 patients. A prospective study was then conducted to ascertain the reliability of the criterion for 82 nodes in another 23 patients. RESULTS: The following equation was obtained from the retrospective study: Y = 1/(1+e(-lambda) (lambda = -7.5709 + 4.2423 X1 + 1.9354 X2 + 0.5507 X3) Y represents the predicted value; lambda, also representing a predicted value, was defined as negative for nonmetastatic and positive for metastatic nodes; X1, signifying the existence of an echogenic hilus, was defined as 0 for presence and 1 for absence; X2, signifying the internal echo pattern, was defined as 0 for homogeneous and 1 for heterogeneous; X3, signifying the minimal diameter, was the actual measured value (mm). This equation showed a sensitivity of 82%, a specificity of 91%, and an accuracy of 88% in the prospective study. CONCLUSION: The equation calculated by logistic regression analysis was a reliable criterion for diagnosing cervical lymph node metastasis.

Adult↗
PubMed1999

Case report of lymphoepithelioma-like carcinoma of the lung--lymphoid population consisting of cytotoxic T cells in resting state.

The present report describes a case of lymphoepithelioma-like carcinoma (LELC) of the lung and presents immunohistochemical and in situ hybridization (ISH) studies of the tumor. A 39-year-old Chinese woman, who was born in China and emigrated to Japan at the age of 29, suffered from a cough for 2 years and received a middle and lower lobectomy with mediastinal lymph node dissection after induction chemotherapy. The tumor consisted of undifferentiated carcinoma and areas of more differentiated squamous cell carcinoma with an intense lymphoid infiltrate. Serological studies and ISH studies showed EBV infection of the tumor. The immunophenotype of tumor-infiltrating T-lymphocytes (TITL) of the present case was examined immunohistochemically and was compared with that of an LELC case reported previously. Most CD3-positive T cells of TITL in both cases were labeled with both CD8 and TIA-1 but not with granzyme-B, indicating the TITL to be cytotoxic T lymphocytes (CTL) in the resting state. The lack of CTL activation at the tumor site might have been due to local inhibition of EBV-specific CTL responses such as T-cell anergy. Because the EBV-specific CTL derived from peripheral blood lymphocytes, in contrast to the TITL, may not be influenced by either tumor-produced suppressor factors or negative regulatory T cells, they may inhibit the hematogenous metastasis of EBV-positive LELC, possibly resulting in a better prognosis. Because LELC of the lung responded to preoperative chemotherapy in the present study, it may be useful for reducing the local tumor burden and facilitate subsequent local therapy, although the mechanism of chemosensitivity of LELC remains unknown.

Adult↗
PubMed1999

Dose-response relationships between drinking and serum tests in Japanese men aged 40-59 years.

Alcohol intake per Japanese adult has been increasing year by year. To show biological effects of drinking, the dose-response relationships between alcohol use and serum indices were analyzed in 5919 Japanese men aged 40-59 years. The subjects were classified into nine groups: a nondrinking (ND, n = 1827) group and eight drinking (1D-8D) groups, by self-reported drinking habit. The 1D (the lightest drinking, n = 699), 5D (n = 942), and 8D (the heaviest drinking, n = 46) groups consumed alcohol less than 30 g per week, 25-30 g alcohol per day, and 100 g alcohol per day or more, respectively. Ten serum indices, total cholesterol, HDL cholesterol, triglyceride, total/HDL cholesterol ratio, LDL cholesterol, gamma-glutamyl transpeptidase, aspartate aminotransferase, alanine aminotransferase, glucose, and uric acid, were used. The dose-response analysis was statistically controlled for age, body mass index, smoking, and habitual exercise, and showed that drinking, even a small amount of alcohol, always had both beneficial and adverse effects on humans. However, alcohol less than 30 g per day may be tolerable for middle-aged Japanese men, because it improved serum lipids profile but did not induce apparent liver cell damage, hyperglycemia, or hyperuricemia.

Adult↗
PubMed1999

Increased expression of inducible nitric oxide synthase and peroxynitrite in Helicobacter pylori gastric ulcer.

The role of nitric oxide in ulcer formation remains unknown. Accordingly, we assessed local expression of inducible nitric oxide synthase (NOS) and nitration of tyrosine as an indicator of peroxynitrite formation in patients with Helicobacter pylori (HP)-associated gastric ulcers compared with HP-negative ulcers. Biopsy specimens were taken from the ulcer margin and from an area remote from the ulcer portion. Inducible NOS, nitrotyrosine, and macrophage immunoreactivity were assessed immunohistochemically using a labeled streptavidin-biotin method. In HP-positive gastric ulcers, inducible NOS and nitrotyrosine immunoreactivity was frequently observed at active ulcer margins, sometimes in surface epithelial cells as well as in the lamina propria. Occasionally, inducible NOS and nitrotyrosine reactivity were found in areas remote from the lesion in cases of HP-positive ulcer and HP-related gastritis. Macrophages accumulated significantly in the margin of HP-positive ulcers. In HP-negative gastric ulcers, inducible NOS and nitrotyrosine immunoreactivity also were frequent at the ulcer margin, but no significant immunoreactivity was observed at a distance. HP eradication caused significant attenuation in inducible NOS and macrophage immunoreactivity. In conclusion, nitric oxide and peroxynitrite formation is increased in HP-infected gastric mucosa, suggesting that HP promotes nitric oxide stress.

Fluorescent Antibody Technique↗
PubMed1999

Alteration of muscle fiber composition linking to insulin resistance and hypertension in fructose-fed rats.

The aim of this study was to examine the role of muscle fiber composition in insulin resistance and the effect of a calcium channel antagonist on insulin sensitivity in fructose-induced insulin resistant and hypertensive rats. Six-week-old male Sprague-Dawley rats were fed either normal rat chow (control) or fructose-rich diet (FFR). For the last 2 weeks of a 6-week period of either diet, the rats were treated, by gavage, with gum arabic solution (control or FFR) or a dihydropyridine calcium channel antagonist, benidipine hydrochloride (3 mg/kg/day: FFR + Ca), then the euglycemic hyperinsulinemic glucose clamp technique was performed to evaluate insulin sensitivity. Blood pressure was measured weekly for 6 weeks. At the end of the glucose clamp, the soleus muscle was dissected out for determination of muscle fiber composition by ATPase methods. Blood pressure was elevated at 2 weeks after the start of fructose-rich chow feeding and persisted thereafter throughout the study. Blood pressure at the glucose clamp in the FFR was significantly higher than that in the control group (142 +/- 2 v 155 +/- 2 mm Hg, P < .01) and the calcium antagonist significantly lowered blood pressure of FFR (136 +/- 6 mm Hg for FFR +/- Ca, P < .05). The average rate of glucose infusion during glucose clamp, as a measure of insulin sensitivity (M value), was significantly lower in the FFR than in the control (15.4 +/- 0.4 v 10.9 +/- 0.6 mg/kg/min, P < .01). The calcium channel antagonist partially improved the M value compared to that of FFR (13.4 +/- 0.7 mg/kg/min in FFR +/- Ca, P < .01 compared to FFR, P < .05 compared to control). The composite ratio of type I fiber in soleus muscle was significantly decreased in FFR compared to control (81.7 +/- 1.5% v 75.0 +/- 1.7%, P < .01), and the composite ratio of type I fiber in rats treated with the calcium channel antagonist (FFR +/- Ca) recovered to the control level (79.9 +/- 1.1%, P < .05 compared to FFR). The M value was significantly correlated with the compositions of type I and type II fibers (for type I fibers, r = 0.80, P < .01; for type II fibers, r = -0.81, P < .01). These results suggest that fiber composition of skeletal muscle links insulin resistance and that a calcium channel antagonist may modulate muscle fiber composition in hypertensive animal model, fructose-fed rats.

Animals↗
PubMed1999

Role of the angiotensin type 2 receptor gene in congenital anomalies of the kidney and urinary tract, CAKUT, of mice and men.

Angiotensin type 2 receptor gene null mutant mice display congenital anomalies of the kidney and urinary tract (CAKUT). Various features of mouse CAKUT impressively mimic human CAKUT. Studies of the human type 2 receptor (AGTR2) gene in two independent cohorts found that a significant association exists between CAKUT and a nucleotide transition within the lariat branchpoint motif of intron 1, which perturbs AGTR2 mRNA splicing efficiency. AGTR2, therefore, has a significant ontogenic role for the kidney and urinary tract system. Studies revealed that the establishment of CAKUT is preceded by delayed apoptosis of undifferentiated mesenchymal cells surrounding the urinary tract during key ontogenic events, from the ureteral budding to the expansive growth of the kidney and ureter.

Animals↗