Search PubMed⌕ Search

Biomedical subjects

S Inoue

Publications and source records attributed to S Inoue.

At least 199 records · Page 11Linked to original sources

Identification of a novel polymorphism of estrogen receptor-alpha gene that is associated with calcium excretion in urine.

A novel variation of the estrogen receptor-alpha (ERalpha) gene was identified by polymerase chain reaction-single-strand conformational polymorphism (PCR-SSCP). It is one base substitution in codon 325 (CCC [allele M] to CCG [allele m]) in exon 4 of the human ERalpha gene. This substitution did not cause an amino acid change. We categorized 306 unrelated Japanese postmenopausal women into three genotypes: MM, Mm, and mm; the frequency of each genotype was 26.5%, 43.1%, and 30.4%, respectively. Then, the association of this polymorphism with bone mineral density (BMD) of lumbar spine and bone-calcium metabolic markers was studied. There was no significant difference in BMD of the lumbar spine or most of the bone metabolic markers. However, the urinary calcium (Ca) excretion ratio (u-Ca/Cre) corrected by creatinine was significantly lower in the genotype mm group compared with the genotype MM group (MM vs mm, 0.247 +/-0.158 vs 0.200 +/- 0.105; P < 0.05). We examined the relationship of restriction fragment length polymorphisms (RFLPs) (PvuII, XbaI) in intron 1 and the polymorphism in exon 4. The frequency of genotype MM was higher in the genotype PPxx, which was reported to be associated with lower BMD in the same population of Japanese postmenopausal women. The ER polymorphism identified in this study might be related to some biological mechanisms that regulate calcium metabolism.

Bone Density↗

A 10- to 13-year follow-up study of Harris-Galante type prosthesis in total hip arthroplasty.

Long-term clinical results of Harris-Galante type prosthesis in total hip arthroplasty (THA) were evaluated in 27 hip joints of 25 patients (2 men and 23 women). Seventeen joints also received bone grafting on the acetabulum. Mean follow-up period was 11 years and 3 months. Clinical out-come was evaluated using the hip score of the Japanese Orthopaedic Association, and the score was good and stable during the monitoring period. Implant stability, bone changes around the implant, and the occupancy rate of the stem in the medullary space were radiologically examined. As a result of stem, there was subsidence in 3 joints and loosening in 6. There were no cases of cup loosening. A pedestal was found in 12 joints, and 4 of them which were associated with a radiopaque line had stem loosening. Among the 21 joints without loosening, 8 had a pedestal but they were not associated with a radiopaque line. The 2 joints which developed osteolysis did not have loosening. Stem loosening was related to the stem occupancy rate in the distal part of the medullary cavity. Postoperative stem occupancy rate could be an important indicator for long-term clinical results. Stems for cementless THA should be designed to have a high occupancy rate in the distal part, and stems should also be carefully chosen to meet individual differences.

Adult↗

Non-traumatic osteonecrosis of the femoral head treated with transtrochanteric anterior rotational osteotomy combined with vascularized iliac bone grafting.

A 49-year-old Japanese man who had non-traumatic osteonecrosis of the femoral head with a wide necrotic lesion received transtrochanteric anterior rotational osteotomy combined with vascularized iliac bone grafting. After the bone graft (6 x 1.5 cm) was collected, the femoral head was anteriorly rotated by 90 degrees. A bone tunnel of 1.2 cm in diameter was prepared on the necrotic lesion adjacent to the intact area from the anterior part of the femoral neck to inside the femoral head. The bone graft was trimmed to the size of this bone tunnel, and inserted up to immediately below the articular surface. In the monitoring using T1-weighted magnetic resonance imaging (MRI), the low signal-intensity area between the bone graft and intact area had disappeared, and a high signal-intensity area on the weight-bearing portion of the femoral head had extended. With modifications on the insertion point of the bone graft, transtrochanteric anterior rotational osteotomy combined with vascularized iliac bone graft would be a useful means to preserve the femoral head in large non-traumatic osteonecrosis of the femoral head.

Bone Transplantation↗

Histological findings of bone marrow edema pattern on MRI in osteonecrosis of the femoral head.

Sequential magnetic resonance imaging (MRI) was performed on a 38-year-old woman with systemic lupus erythematosus who had received corticosteroid and had developed non-traumatic osteonecrosis of the femoral head. The initial MR finding was a band lesion on the T1-weighted image, which had been present before the onset of symptoms. At the onset of symptoms, a diffuse bone marrow edema pattern, with a low signal intensity on T1 and high signal intensity on T2-weighted images, was noted around the band lesion, extending to the femoral neck. Histopathologically, this region was found to consist of serous exudate, focal interstitial hemorrhage, and mild fibrosis, without any evidence of extension of osteonecrosis. It should be noted that extension of a low signal intensity area on MRI after the onset of hip pain may not be the result of the extension of osteonecrosis, but may represent concomitant edema due to collapse.

Adult↗

Association of estrogen receptor beta (ESR2) gene polymorphism with blood pressure.

We investigated the association between a dinucleotide (cytosine-adenine; CA) repeat polymorphism located in the flanking region of the human estrogen receptor beta (ESR2) gene and systemic blood pressure in 187 healthy postmenopausal Japanese women. The genotype was classified as "A" through "O" according to the number of these repeats from 18 to 32. When we separated the subjects into two groups-- bearing at least one "I" allele (26 CA repeats) and those who did not--we found that the former subjects had significantly higher systolic blood pressure than the latter (mean +/- SD, 146.0 +/- 25.0 vs 136.6 +/- 23.4; P = 0.032). These data suggest that genetic variation at the ESR2 locus may be associated with some determinants of blood pressure, and that there is a possible involvement of this polymorphism in causing hypertension in Japanese women.

Aged↗

Association of bone mineral density with a dinucleotide repeat polymorphism at the calcitonin (CT) locus.

Calcitonin (CT), a calcium-regulating hormone, lowers the calcium level in serum by inhibiting bone resorption. Because CT may play a role in the pathogenesis of osteoporosis, genetic variations in or adjacent to the CT gene may be associated with variations in bone mineral density (BMD). The present study examined the correlation between a dinucleotide (cytosine-adenine; CA) repeat polymorphism at the CT locus and BMD in 311 Japanese postmenopausal women (mean age, 64.1 years). Seven alleles were present in this population; each allele contained 10, 11, 16, 17, 18, 19, or 20 CA repeats. Thus, we designated the respective genotypes A10, A11, A16, A17, A18, A19, and A20. The A10 and A17 alleles were the predominant alleles in the population studied. Z scores (a parameter representing deviation from the age-specific weight-adjusted average BMD) were compared between individuals that possessed one or two alleles of each genotype and those that did not possess the allele. Subjects who possessed one or two A10 alleles had lower BMD Z scores than those who did not (lumbar 2-4 BMD Z score; -0.148 +/- 1.23 vs 0.182 +/- 1.54; P = 0.04). No significant relationships were observed between allelic status and background data or biochemical parameters. The significant association observed between BMD and genetic variations at the CT locus implies that polymorphism at this locus may be a useful marker for the genetic study of osteoporosis.

Aged↗

JTT-501, a new oral hypoglycemic agent, reverses hypertriglyceridemia in Zucker fatty and ventromedial hypothalamus-lesioned obese rats.

JTT-501 is a new oral hypoglycemic agent that is reported to be effective in insulin-resistant diabetic animal models by improving insulin resistance. It also improves hypertriglyceridemia. We investigated the mechanism of the reversal of hypertriglyceridemia in two types of obese animals using JTT-501. In Zucker fatty obese rats, an animal model of genetic obesity, fasting plasma triglyceride and glucose significantly decreased after a single daily oral dose of JTT-501 (100 mg/kg) for 7 days. In ventromedial hypothalamus (VMH)-lesioned obese rats, an animal model of nongenetic obesity, fasting plasma triglycerides significantly decreased but fasting plasma glucose levels remained unchanged after treatment with this agent. In Sprague-Dawley (SD) rats, fasting plasma triglyceride and glucose levels remained unchanged. The JTT-501-treated Zucker fatty and VMH-lesioned obese rats showed a decrease in insulin, but it was not significant, while the treated SD rats showed a significant decrease in insulin. Postheparin plasma lipoprotein lipase (LPL) increased significantly in treated Zucker fatty obese and SD rats, but did not change in VMH-lesioned obese rats. The hepatic triglyceride secretion rate (TGSR) did not change in any species treated with JTT-501. There was a negative correlation between postheparin plasma LPL and plasma triglyceride levels in Zucker fatty obese rats, while no such correlation was observed in VMH-lesioned obese or SD rats. The fractional catabolic rate (FCR) for plasma triglyceride was increased significantly by JTT-501 in both Zucker fatty and VMH-lesioned obese rats. These results suggest that JTT-501 decreases plasma triglycerides mainly by increasing postheparin plasma LPL in Zucker fatty obese rats, while it ameliorates an impairment in the ability of adipose tissue to remove triglyceride from the circulation in VMH-lesioned obese rats.

Animals↗

Severe ectopic calcification of the intestinal wall in a patient on long-term continuous ambulatory peritoneal dialysis therapy.

We report autopsy findings of a 69-year-old man on long-term CAPD therapy for 13 years who showed linear peritoneal calcification. Continuous ambulatory peritoneal dialysis (CAPD) was started in 1982. He has been administered excessive amounts of vitamin D(3) derivatives (VitD) (2.0 to 2.5 microg daily) and calcium carbonate (4 g daily) for secondary hyperparathyroidism since initiation of CAPD. In May 1995, his intact parathyroid hormone (PTH) level increased over 1,000 pg/mL. Immediately after VitD was changed from pill to liquid, the dose was increased to 5 microg daily. Although the serum calcium level remained between 4.5 and 4.9 mEq/L, and serum phosphate level was 5.0 to 7.2 mg/dL, plain abdominal radiography and computed tomography showed continuous calcification along the intestinal wall in October 1995. In spite of the continuation of CAPD therapy, he remained asymptomatic until he died of congestive heart failure in January 1997. He experienced eight episodes of peritonitis during his clinical course. Autopsy showed that numerous calcified plaques were present on the submucosal portion between the thickened serosa and the longitudinal layer of the muscularis externa. The remainder of the subserosa was fibrotic, and the small arteries had markedly thickened intima and severely narrowed lumina.

Abdominal Muscles↗

Ibotenic acid-induced lesions of the medial septum increase hippocampal membrane associated protein kinase c activity and reduce acetylcholine synthesis: prevention by a phosphatidylcholine/vitamin B12 diet.

Ibotenic acid infusion into the medial septum (MS) results in biochemical alterations in the hippocampus. The biochemical events involved in this neuronal lesion are poorly understood. We investigated the effect of a purified diet supplemented with egg phosphatidylcholine (PC) and vitamin B(12) on ibotenic acid-medicated biochemical changes in the rat hippocampus and crude synaptosomal membranes. Male Wistar rats with this MS lesion were fed a purified diet (control diet) or a purified diet supplemented with 5.7 g PC and 125 microg vitamin B(12) per 100 g (experimental diet) for 18 days. Sham-operated rats were fed the control diet. Compared with the sham-operated rats, MS-lesioned rats fed the control diet showed increased activity of membrane-bound protein kinase C (PKC), decreased activity of choline acetyltransferase, and decreased concentrations of acetylcholine in the hippocampus. The ratio of cholesterol to phospholipid in the crude synaptic membrane was lower in the lesioned rats than in the sham-operated rats, but this was not accompanied by any alteration in membrane lipid fluidity. MS-lesioned rats fed the experimental diet showed lowered PKC activity and elevated acetylcholine concentrations than did rats fed the control diet, but there were no significant effects on choline acetyltransferase activity and the lipid ratio. The ibotenic acid-mediated elevation of PKC activity was observed as early as 2 days postinjury in the control diet-fed rats but not in the experimental diet-fed rats. We propose that ibotenic acid mediates pathophysiologic actions through the activation of PKC and that PC combined with vitamin B(12) ameliorates the second messenger-mediated injury.

Journal Article↗

Atrium as a source of brain natriuretic polypeptide in patients with atrial fibrillation.

BACKGROUND: Plasma brain natriuretic polypeptide (BNP) levels have been used as biochemical markers of systolic left ventricular (LV) dysfunction. Although in vitro studies have shown the existence of BNP messenger RNA in the atria, the main production site of BNP is believed to be the ventricle. The hypothesis that the atrium could be a source of BNP was examined in patients with lone atrial fibrillation (AF), the most common type of sustained arrhythmia. METHODS AND RESULTS: We studied 16 controls and 21 patients with lone AF. Plasma samples for BNP were selectively and serially obtained from the aorta, anterior interventricular vein (AIV), and coronary sinus (CS). Atrial natriuretic polypeptide (ANP) levels were also measured to determine whether the CS samples contained significant amounts of atrial venous drainage. Of the 3 sample locations, the CS had the greatest ANP levels, confirming transcatheter sampling position accuracy. BNP levels were significantly greater in the CS than AIV in the patients with AF (279 +/- 226 v 126 +/- 97 pg/mL; P < .01). Consequently, plasma BNP levels were also greater in the patients with AF than controls (103 +/- 90 v 5 +/- 2 pg/mL; P < .001). LV ejection fraction was significantly less in patients with AF than control patients. Atrial production of BNP decreased significantly after successful DC cardioversion of AF in the 5 restudied patients (182 +/- 139 v 59 +/- 64 pg/mL; P < .05). CONCLUSION: The data suggest that AF is a condition in which BNP is produced in the atrium itself.

Adult↗

Effects of tea catechins on the ERE-regulated estrogenic activity.

Tea catechins exert many biological effects, including anticancer and antibacterial activities. Also, it is reported that some plant flavonoids exhibit estrogenic activity. In this study, we investigated estrogenic or antiestrogenic activities of catechins in HeLa cells transiently transfected with an estrogen response element (ERE)-regulated luciferase reporter and an estrogen receptor (ER) alpha or ERbeta expression vector. Catechins alone did not induce luciferase (luc) activity in either of the ERs. Addition of 17beta-estradiol (E2) plus epicatechin gallate (ECG) or epigallocatechin gallate (EGCG) at 5 x 10(-6) M resulted in significant decreases in the ERalpha-mediated luc activity compared with that of E2 alone. On the contrary, lower concentrations significantly increased the E2-induced luc activity. Similar effects were observed with tamoxifen. The ERbeta-mediated estrogenic activities were stimulated by catechins. In conclusion, some catechins, particularly EGCG, were antiestrogenic for ERalpha at higher doses, and co-estrogenic for ERalpha at lower doses and for ERbeta. The lower doses were found in human plasma after tea-drinking. In addition, some catechins may be antiendocrine disruptors because they suppressed bisphenol A-induced luc activities.

Catechin↗

Relation of lifestyle factors to metacarpal bone mineral density was different depending on menstrual condition and years since menopause in Japanese women.

OBJECTIVE: To examine whether the relation between lifestyle and metacarpal bone mineral density (BMD) varied with life-stages. DESIGN: Cross-sectional study. SETTING: Taking questionnaires related to lifestyle and examining metacarpal BMD by computed X-ray densitometry at a local health care center. SUBJECTS: Out of 750 Japanese women aged 40-69 y old who underwent screening for osteoporosis, we selected 535 healthy subjects without medical conditions or lifestyle factors known to affect bone metabolism. RESULTS: A cross-sectional comparison of BMD and years since menopause (YSM) resulted in a logarithmic regression model (BMD=2. 539-0.149xloge YSM, r2=0.418), indicating that a prominent reduction in metacarpal BMD appears up to 4-6 y after menopause. In premenopausal women with regular menstruation, those who engaged in regular physical activity during adolescence showed significantly greater BMD than those who did not. In 1-5-y postmenopausal women, those with current calcium intake of more than 800 mg/d, current milk intake greater than 900 ml/week, daily consumption of milk and/or dairy products, or frequent consumption of small fish showed significantly greater BMD. In 6-15-y postmenopausal women, those who took more than 6000 or 8000 steps/day showed significantly greater BMD. CONCLUSIONS: The relation between lifestyle and BMD differed with life-stages in Japanese women. It was suggested that to perform lifestyle modifications for the prevention of osteoporosis, life-stages should be taken into consideration. SPONSORSHIP: Grant for Research on Health Service from Ministry of Health and Welfare, Japan and grant from The National Dairy Promotion and Research Association of Japan. European Journal of Clinical Nutrition (2000) 54, 9-13

Adult↗

Anti-obesity effects of lipase inhibitor CT-II, an extract from edible herbs, Nomame Herba, on rats fed a high-fat diet.

OBJECTIVE: To investigate the inhibitory effects of CT-II, extract of Nomame Herba, on lipase activity in vitro and on obesity in rats fed a high-fat diet in vivo. DESIGN: The assay for the inhibitory effect of CT-II on lipase activity was performed by measuring released free fatty acids after the incubation of the medium with CT-II, porcine pancreatic lipase and triolein (experiment 1). In vivo experiments, lean rats or obese rats (570-718 g) were fed a high-fat diet containing 60% fat with or without CT-II for 8 weeks (experiment 2), for 14 days (experiment 3) or for 12 weeks (experiment 4), respectively. MEASUREMENT: The time course of body weight, food intake, organ weight (parametrial fat, liver, heart and kidney) and plasma parameters (triglyceride, total cholesterol, glucose, AST, ALT and insulin), fecal output of total fat and total cholesterol were measured. Hepatic histological examinations were also performed. RESULTS: CT-II inhibited the porcine lipase activity dose-dependently in vitro (experiment 1). Body and liver weight were reduced and hepatic histological examination showed an amelioration of fatty liver in CT II treated animals (experiment 2). CT-II significantly inhibited body weight gain and plasma triglyceride elevation in a dose-dependent manner, without affecting food intake in lean rats fed the high-fat diet. Elevated plasma AST and ALT were also decreased (experiment 3). When obese rats fed the high-fat diet were treated with CT-II for up to 6 months, body weight was initially reduced and thereafter weight gain was significantly suppressed. Total body fat was also significantly reduced and significant reduction of plasma AST and ALT was observed (experiment 4). CONCLUSIONS: These results demonstrated that the lipase inhibitor CT-II is effective in preventing and ameliorating obesity, fatty liver and hypertriglyceridemia in rats fed a high-fat diet.

Alanine Transaminase↗

Ion chromatographic analysis of hydronium ion using ODS modified with dodecylsulfate as the stationary phase.

The hydronium ion (H3O+), the most essential species to every field of chemistry, was successfully separated from other cations. This major goal was achieved by a HPLC approach in which a reversed-phase ODS which had been initially modified with dodecylsulfate was used as the stationary phase and an aqueous KNO3 solution was used as the mobile phase. Of all tested monovalent cations (analyte ions), the hydronium ion (H3O+) showed the highest affinity towards the stationary phase, followed by NH4+, Na+, and then Li+. The hydronium ion, after the separation, was directly detected using conductivity and the detection signal (conductivity) was in linear proportion (linear range 7.8 x 10(-4)-0.45 M; injection volume, 100 microL) to the concentration of the acid species of the tested sample. This proposed HPLC method was applicable to separate/detect H3O+ from both strong and weak acidic samples.

Journal Article↗

Elimination of atretic follicles from the mouse ovary: a TEM and immunohistochemical study in mice.

We examined numerous ovarian follicles from 32-35 d virgin mice by transmission electron microscopy and light microscopic immunohistochemistry. No macrophages were seen, but various stages of apoptotic granulosa cells were encountered. Presumably a granulosa cell or its debris in an advanced stage of apoptosis was destined to be phagocytosed by adjacent normal-looking granulosa cells. Other granulosa cells of normal appearance were seen in the region of the zona pellucida in contact with and apparently phagocytosing atrophic oocytes. Such granulosa cells were characterised by the presence of gap junctions with other cells and frequently contained annular gap junctions in the cytoplasm. To confirm the lack of involvement of macrophages in the process of follicular atresia and elimination, specially prepared ovarian sections were incubated with antimouse macrophage monoclonal antibodies (F4/80, Mac-1, Mac-2). None of the follicles examined showed positive immunoreactivity with these antibodies. Atretic follicles may shrink and eventually disappear from the ovary as a result of repeated apoptosis and phagocytosis by granulosa cells. There is no evidence for the presence or involvement of macrophages in the atretic follicles, at least in prereproductive mice as examined.

Animals↗

Histamine induces melanogenesis and morphologic changes by protein kinase A activation via H2 receptors in human normal melanocytes.

Hyperpigmentation frequently accompanies chronic or acute inflammation. A number of inflammatory mediators have been shown to stimulate melanin synthesis in human melanocytes. Although histamine is ubiquitous as an inflammatory factor, its involvement in pigmentation remains obscure. In this work, we examined the effects of histamine on cultured human melanocytes. Treatment of human melanocytes with 0.1-10 microM histamine evoked morphologic changes and increases in tyrosinase activity. The concomitant increases in melanin content of the histamine-treated melanocytes indicated an elevation of melanin synthesis by tyrosinase activation. These stimulatory effects of histamine were completely inhibited by an H2 antagonist, famotidine, whereas H1 and H3 antagonists had no inhibitory effect whatsoever. In addition, an H2 agonist, dimaprit, induced the same degree of melanogenesis as histamine at concentrations of 0.1-10 microM. We observed an increase in the intracellular cAMP contents of human melanocytes induced by histamine via the H2 receptors. We know that this cAMP accumulation and subsequent protein kinase A activation plays a critical role in histamine-induced melanogenesis, because a specific protein kinase A inhibitor, H-89, completely suppressed these stimulatory effects of histamine, and because dibutylic cAMP, a specific protein kinase A activator, stimulated human melanocytes as potently as histamine. Taken together, we show here that histamine induces melanogenesis of human cultured melanocytes by protein kinase A activation via H2 receptors.

Cell Division↗