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Biomedical subjects

A Nohara

Publications and source records attributed to A Nohara.

At least 19 recordsLinked to original sources

A novel method for measuring human hepatic lipase activity in postheparin plasma.

The objective of this study was to establish a hepatic lipase (HL) assay method that can be applied to automatic clinical analyzers. Seventy-four hyperlipidemic subjects (men/women 45/29) were recruited. Lipase activity was assayed measuring the increase in absorbance at 546 nm due to quinonediimine dye production. Reaction mixture R-1 contained 50 mM Tris-HCl (pH 9.5), 0.5 mM glycerol-1,2-dioleate, 0.4% (unless otherwise noted) polyoxyethylene-nonylphenylether, 3 mM ATP, 3 mM MgCl(2), 1.5 mM CaCl(2), monoacylglycerol-specific lipase, glycerol kinase, glycerol-3-phosphate oxidase, 0.075% N,N-bis-(4-sulfobutyl)-3-methylaniline-2 Na, peroxidase, ascorbic acid oxidase. Reaction mixture R-2 contained 50 mM Tris-HCl (pH9.5), 0.15% 4-aminoantypirine. Automated assay for activity was performed with a Model 7080 Hitachi analyzer. In the lipase assay, 160 microl of R-1 was incubated at 37 degrees C with 3 microl of samples for 5 min, and 80 microl of R-2 was added. Within-run coefficient of variations was 0.9-1.0%. Calibration curve of lipase activity was linear (r = 0.999) between 0 and 320 U/l. Analytical recoveries of purified HL added to plasma were 96.6-99.8%. HL activity in postheparin plasma measured in this method had a closer correlation with HL mass by a sandwich ELISA (r = 0.888, P < 0.0001) than those in the conventional method using [(14)C-]triolein (r = 0.730, P < 0.0001). This assay method for HL activity can be applied to an automatic clinical analyzer.

Adult↗

Course of damage to the hallux over 5 years after forefoot resection arthroplasty in rheumatoid arthritis patients.

A retrospective study of 34 feet from 20 consecutive patients with rheumatoid arthritis was performed to investigate the development of damage to the hallux over 5 years after forefoot resection arthroplasty. Radiographically we analysed changes in two valgus angles and the interphalangeal joint (IP) damage of the hallux. These parameters were measured preoperatively, 12 months postoperatively, and at the latest follow-up. Although the average HVA (between the first metatarsal and the proximal phalanx) significantly decreased from 38.7 degrees preoperatively to 8.66 degrees postoperatively, the angle increased to 23.0 degrees during the first 12 months following surgery. Further deterioration of the angle at the last follow-up was not detected (25.3 degrees ; P=0.252). The average IPV (between the proximal phalanx and the distal phalanx) angle significantly increased from 6.65 degrees preoperatively to 12.1 degrees 12 months postoperatively and thereafter slightly increased to 13.3 degrees at the latest follow-up. The average of the Sharp/van der Heijde score of the IP joint significantly increased from 5.71 preoperatively to 8.58 12 months postoperatively and thereafter slightly increased to 9.65 at the latest follow-up. The deterioration and destruction process of the hallux after resection arthroplasty occurred soon after surgery, and the progression of the deformity was temporary.

Adult↗

Relationship of lipoprotein lipase and hepatic triacylglycerol lipase activity to serum adiponectin levels in Japanese hyperlipidemic men.

OBJECTIVE: The aim of this study was to determine how lipoprotein lipase (LPL) and hepatic triacylglycerol lipase (HTGL) activity relate to serum adiponectin levels. RESEARCH DESIGN AND METHODS: Fifty-five hyperlipidemic Japanese men were recruited for this study. LPL and HTGL activity in post-heparin plasma (PHP) was measured using Triton X-100 emulsified-[14C] triolein. The remaining activity in the presence of 1M NaCl was defined as HTGL activity. Serum adiponectin levels were determined by an enzyme-linked immunosorbent assay system. RESULT: LPL activity had a positive relationship with HDL2, but had no relation with HDL3, while HTGL had positive relationship with HDL3, but had no relationship with HDL2. LPL activity showed a positive relationship [r = 0.345, p = 0.010] to serum adiponectin levels, while and HTGL activity showed an inverse relationship [r = - 0.365 p = 0.006]. Multiple regression analysis with LPL and HTGL as dependent variables and age, BMI, serum adiponectin and the homeostasis model assessment of insulin resistance (HOMA-IR) as independent variables showed LPL and HTGL's association to adiponectin did not persist after adjustments for these covariants. However, the association of LPL activity to HOMA-IR was found to persist after adjustments of age, BMI, and serum adiponectin. CONCLUSIONS: There was a co-linearity between insulin sensitivity and adiponectin as well as insulin sensitivity and LPL/HTGL activity.

Aged↗

Circulating matrix metalloproteinases and their inhibitors in premature coronary atherosclerosis.

To investigate the clinical significance of circulating matrix metalloproteinases (MMPs) and their tissue inhibitos (TIMPs) in patients with premature coronary atheroscrelosis, we studied 53 consecutive male patients with angiographically defined premature (<65 years) and stable coronary artery disease. Plasma levels of MMP-2, MMP-3, MMP-9, TIMP-1, and TIMP-2 were determined in peripheral blood by a sandwich enzyme immunoassay, and the results were compared with those from 133 age-matched control males. There were significant differences in all the MMPs and TIMPs (p<0.001) between patients and controls. In the patient group, the levels of MMP-9 (mean +/- SD (ng/ml) 27.2 +/- 15.2/21.8 +/- 15.2) and TIMP-1 (130.4 +/- 55.7/94.5 +/- 26.3) were significantly higher, and the levels of MMP-2 (632.5 +/- 191.6/727.6 +/- 171.4), MMP-3 (53.1 +/- 31.2/79.6 +/- 29.9), and TIMP-2 (24.7 +/- 15.2/35.4 +/- 16.4) were significantly lower than those of controls. We found significant positive correlation between plasma MMP-9 levels and low-density lipoprotein (LDL)-cholesterol levels (Rs = 0.168, p = 0.022), and significant negative correlation between plasma MMP-9 levels and high-density lipoprotein (HDL)-cholesterol levels (Rs = -0.164, p = 0.026) by Spearman rank correlation test. In contrast, plasma MMP-2 (Rs = 0.181, p = 0.014) and MMP-3 (Rs = 0.260, p = 0.0004) levels were positively correlated with HDL-cholesterol levels. TIMP-2 levels were negatively correlated with total cholesterol (Rs = -0.197, p = 0.007) and LDL-cholesterol (Rs = -0.168, p=0.022) levels. These results suggest that the circulating levels of MMPs and TIMPs are altered in patients with premature coronary atherosclerosis and that plasma lipoprotein cholesterol levels correlate with these, possibly as a result of the lipoprotein-vessel wall interactions.

Biomarkers↗

Effect of common methylenetetrahydrofolate reductase gene mutation on coronary artery disease in familial hypercholesterolemia.

Familial hypercholesterolemia (FH) is an autosomal dominant disorder characterized by primary hypercholesterolemia and premature coronary artery disease (CAD). However, the development of CAD in FH shows considerable interindividual variations. Elevated levels of plasma homocysteine have been recognized as independent risk factors for CAD. A 5,10-methylenetetrahydrofolate reductase (MTHFR) gene mutation (valine [V] was substituted for alanine [A]) has been reported to be associated with elevated levels of plasma homocysteine in mutant homozygotes (i.e., VV). We studied 199 consecutive male heterozygous FH patients, 99 with and 100 without CAD. In the CAD group, genotype VV and V alleles were significantly more frequent than in the non-CAD group (15% vs 7% in genotypes [p = 0.035] and 0.41 vs 0.30 in alleles [p = 0.017]). The mean ages at onset in the CAD group were 50, 51, and 43 years for genotypes AA, AV, and VV, respectively (p <0.05); the age of onset of CAD in genotype VV was significantly lower than in the other 2 genotypes. Kaplan-Meier survivor curves indicated that the development of CAD was significantly accelerated by MTHFR mutation, probably in a gene dose-dependent manner. Furthermore, only MTHFR genotype VV was shown to be an independent predictor of the early onset of CAD in a stepwise multiple regression analysis. The mean plasma homocysteine levels of genotype VV were significantly higher than those of the other 2 genotypes. Thus, the MTHFR mutation appears to accelerate the onset of CAD through elevation of plasma homocysteine levels in male heterozygous patients with FH.

Adult↗

Plasma homocysteine level and development of coronary artery disease.

BACKGROUND: The plasma level of homocysteine is an independent risk factor for atherosclerotic vascular disease. The relationship between plasma homocysteine level and the onset of coronary artery disease (CAD) has not been established. OBJECTIVE: To investigate the relationship between plasma homocysteine level and the age at which CAD was diagnosed. METHODS: Fifty-seven male patients aged < or = 65 years (mean age 53 years) with angiographically proven symptomatic CAD seen consecutively and 138 age-matched male control subjects (mean age 52 years) free from atherosclerotic vascular disease were studied. They were divided into two subgroups, a group of younger subjects (aged < or = 55 years) and a group of older subjects (aged 56-65 years). RESULTS: Plasma homocysteine levels in CAD patients significantly exceeded those of control subjects (means 13.4 versus 10.6 nmol/ml, P = 0.0002). Plasma homocysteine level of subjects in younger CAD group was significantly higher than that of subjects in older CAD group (15.0 versus 11.3 nmol/ml, P = 0.03), and age and logarithmically transformed plasma homocysteine level exhibited a significant negative correlation (r = -0.28, P = 0.03) for subjects in CAD group. Among control subjects, members of our two age subgroups had similar plasma homocysteine levels. Younger CAD patients had significantly higher plasma homocysteine levels than did younger controls (15.0 versus 10.4 nmol/ml, P < 0.0001). However, for older groups there was no significant difference between plasma homocysteine levels in CAD patients and controls (11.3 versus 10.9 nmol/ml). Multiple regression analysis showed that only logarithmically transformed plasma homocysteine level was a significant predictor for age of onset of CAD. CONCLUSION: An elevated level of plasma homocysteine is more important in the development of premature CAD than it is in that of late-onset CAD among men.

Adult↗

Prolactin stimulates mitogen-activated protein kinase in human leiomyoma cells.

The effects of prolactin (PRL) on proliferation of cultured human uterine leiomyoma-derived smooth muscle cells (SMC) and its mechanism of action were investigated. PRL stimulated DNA synthesis and the expression of PRL receptor was identified by ribonuclease protection assay. Moreover, the regulation of mitogen-activated protein (MAP) kinase by PRL in leiomyoma-derived SMC was investigated. PRL stimulated MAP kinase activity, as detected by 32P incorporation into MAP-2, in a dose-dependent manner. PRL also rapidly stimulated MAP kinase phosphorylation as detected by in vivo phosphorylation using 32P labeling and phosphotyrosine immunoblotting. These results suggest that PRL stimulates the proliferation of human leiomyoma cells via the MAP kinase cascade.

Calcium-Calmodulin-Dependent Protein Kinases↗

Reversibility in blood-brain barrier, microcirculation, and histology in rat brain after decompression.

To examine the changes in blood-brain barrier (BBB), cerebral microcirculation, and histology from 15 min to 72 h after decompression, 90 rats were exposed to experimental compression to 6 atm abs air for 90 min and subsequent rapid decompression. The disruption of BBB was examined by Evans blue extravasation. The cerebral microcirculation was demonstrated by perfusion with India ink. The area stained with Evans blue and the regions of defective filling with India ink, observed immediately after decompression decreased in size with time and were undetectable 3-24 h after decompression. The edematous brain tissue with enlarged perivascular space and darkly stained nerve cells also decreased to the uncompressed control level 1-24 h after decompression. These reversible dysbaric changes, however, reappeared 48-72 h after decompression. The different mechanisms, the physicochemical effects of microbubbles, and the maturation phenomenon after temporary brain ischemia induced by dysbaric microbubbles may be involved in the brain damage after decompression sickness.

Animals↗

The role of mitogen-activated protein kinase in oxytocin-induced contraction of uterine smooth muscle in pregnant rat.

Oxytocin causes the rapid tyrosine phosphorylation of mitogen-activated protein (MAP) kinase in both human and rat puerperal uterine myometrial cultured cells. The potential role of the MAP kinase pathway in oxytocin action was investigated with the specific MAP kinase kinase (MEK) inhibitor, PD98059. Oxytocin stimulation of the tyrosine phosphorylation of MAP kinase in both human and rat cultured puerperal uterine cells was abolished by pretreatment of the cells with MEK inhibitor in a dose-dependent manner. Although MEK inhibitor had no effect on oxytocin-induced intracellular Ca2+ mobilization in either pregnant human or pregnant rat uterine cells, it partly inhibited oxytocin-induced pregnant rat uterine contraction in a dose-dependent manner. These results suggest that MAP kinase pathway may have some important roles in oxytocin-induced uterine contraction.

Animals↗