Outcome of radiofrequency ablation for selective fetal reduction before vs at or after 16 gestational weeks in complicated monochorionic pregnancy.

OBJECTIVE: To investigate whether gestational age at intervention (< or ≥ 16 weeks) and other factors affect the risk of loss of the cotwin after selective fetal reduction using radiofrequency ablation (RFA) in monochorionic (MC) pregnancy. METHODS: This was a single-center retrospective analysis of 63 consecutive RFA procedures performed at our institution from January 2011 to October 2019 for selective fetal reduction in complicated MC pregnancies. Indications for RFA were twin reversed arterial perfusion sequence (13 cases), twin-to-twin transfusion syndrome (12 cases), twin anemia-polycythemia sequence (two cases), selective fetal growth restriction (10 cases), discordant anomalies (17 cases) and multifetal pregnancy reduction in triplets or quadruplets with a MC pair (nine cases). Twenty-six (41.3%) of these procedures were performed before and 37 (58.7%) after 16 weeks. Potential factors that could affect the risk of loss of the cotwin, including gestational age at RFA, order of multiple pregnancy, amnionicity, indication for RFA and number of ablation cycles, were assessed first by univariate analysis and then by multivariate analysis. RESULTS: There were 17 (27.0%) cotwin losses. Ablation cycles numbering four or more was the only factor among those investigated to be associated with loss of the cotwin after RFA (P = 0.035; odds ratio, 5.21), while the indication for RFA, order of multiple pregnancy, amnionicity and gestational age at RFA had no effect. Comparing RFA performed at < 16 vs ≥ 16 weeks, there was no difference in the rate of cotwin loss (23.1% vs 29.7%; P = 0.558) or preterm prelabor rupture of the membranes before 34 weeks (7.7% vs 5.4%; P = 0.853), or in the median gestational age at delivery (36.2 vs 37.3 weeks; P = 0.706). CONCLUSIONS: RFA is a promising tool for early selective fetal reduction in MC pregnancy before 16 weeks. Four or more ablation cycles is a major risk factor for cotwin loss. Careful assessment pre- and post-RFA, together with proficient operative skills to minimize the number of ablation cycles, are the mainstay to ensure that this procedure is effective and safe. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Plasma neutrophil gelatinase-associated lipocalin levels are positively associated with diabetic retinopathy in patients with Type 2 diabetes.

AIM: To assess the relationship between plasma neutrophil gelatinase-associated lipocalin (NGAL) levels and diabetic retinopathy in patients with Type 2 diabetes. METHODS: In total, 204 patients with Type 2 diabetes were investigated in this cross-sectional study. They were classified as having no diabetic retinopathy, non-proliferative diabetic retinopathy (NPDR) or proliferative retinopathy (PDR), according to the degree of diabetic retinopathy. Thus, diabetic retinopathy in the patients in this study was either NPDR or PDR. RESULTS: Plasma NGAL concentrations were significantly higher in patients with diabetic retinopathy than in those without. The mean plasma NGAL levels differed significantly according to the severity of diabetic retinopathy (no diabetic retinopathy, 120.8 ng/ml; NPDR, 217.8 ng/ml; PDR, 372.4 ng/ml; P for trend = 0.002) after adjustment for other covariates. In multivariable analysis, plasma NGAL levels were significantly associated with diabetic retinopathy (odds ratio for each standard deviation increase in the logarithmic value, 7.75; 95% confidence interval, 2.04-29.41, P = 0.003). CONCLUSION: Plasma NGAL levels were positively associated with diabetic retinopathy in patients with Type 2 diabetes.

Prevalence of levator ani muscle injury and health-related quality of life in primiparous Chinese women after instrumental delivery.

OBJECTIVES: Levator ani muscle (LAM) injury is common after first vaginal delivery, and a higher incidence is associated with instrumental delivery. This study was conducted to compare the incidence of LAM injury after forceps or ventouse extraction in primiparous Chinese women, and to study their subsequent health-related quality of life. METHODS: This prospective observational study was conducted between 1 September 2011 and 31 May 2012 in a tertiary obstetric unit. All eligible primiparous women who had undergone instrumental delivery were recruited 1 to 3 days following delivery. The subjects completed the Pelvic Floor Distress Inventory questionnaire and Pelvic Floor Impact Questionnaire, and translabial ultrasound was performed 8 weeks' postpartum to determine whether the subjects had suffered LAM injury. RESULTS: Among the 289 women who completed the study, 247 (85.5%) had ventouse extraction and 42 (14.5%) had forceps delivery. Subsequent translabial ultrasound identified a total of 58 women with LAM injury. The prevalence of LAM injury after ventouse extraction and forceps delivery was 16.6% (95% CI, 12.0-21.2%) (41/247) and 40.5% (95% CI, 25.6-55.4%) (17/42), respectively (P = 0.001). Forceps delivery was identified as a risk factor for LAM injury, with an odds ratio of 3.54. No statistically significant differences were observed between the quality of life in women who underwent ventouse extraction and those with forceps delivery or between the quality of life in women with a unilateral or bilateral LAM injury. CONCLUSIONS: In our cohort of primiparous Chinese women, 20.1% (58/289) had LAM injury after instrumental delivery, and forceps delivery was identified as the only risk factor.

Physiological serum bilirubin concentrations are inversely associated with the prevalence of cardiovascular autonomic neuropathy in patients with Type 2 diabetes.

AIMS: Although severe hyperbilirubinaemia causes kernicterus in neonates, normal to modestly elevated bilirubin concentrations have been reported to be neuroprotective. However, the relationship between serum bilirubin concentrations and cardiovascular autonomic neuropathy in patients with Type 2 diabetes is currently unknown. This study assessed the relationships between physiological serum total bilirubin concentrations and cardiovascular autonomic neuropathy in patients with Type 2 diabetes. METHODS: A total of 2991 patients with Type 2 diabetes were investigated in this cross-sectional study. Cardiovascular autonomic neuropathy was diagnosed by a cardiovascular reflex test. According to the American Diabetes Association criteria, the degree of cardiovascular autonomic dysfunction was graded into normal, early, definite and severe. Cardiovascular autonomic neuropathy was either definite or severe in the present study. An analysis of covariance after adjustment for other covariates was performed. A logistic regression model was used to assess an association of cardiovascular autonomic neuropathy with serum total bilirubin tertiles. RESULTS: Serum total bilirubin concentrations were significantly lower in subjects with cardiovascular autonomic neuropathy. The mean total bilirubin values differed significantly according to the severity of cardiovascular autonomic dysfunction (normal 13.0 µmol/l; early 12.3 µmol/l; definite 11.8 µmol/l; severe 10.1 µmol/l; P for trend < 0.001) after adjustment for other covariates. In multivariate analysis, serum total bilirubin levels were significantly associated with cardiovascular autonomic neuropathy (odds ratio 0.36; 95% CI 0.21-0.63 for the highest vs. the lowest bilirubin tertile, P < 0.001). CONCLUSIONS: Serum total bilirubin concentrations within the physiologic range are inversely associated with the prevalence of cardiovascular autonomic neuropathy in patients with Type 2 diabetes.

Serum bilirubin concentrations are positively associated with serum C-peptide levels in patients with Type 2 diabetes.

AIMS: To investigate the relationship between physiological serum total bilirubin concentrations and serum C-peptide levels in Korean patients with Type 2 diabetes. METHODS: A total of 588 patients with Type 2 diabetes were investigated in this cross-sectional study. Fasting C-peptide level, 2-h postprandial C-peptide level and ΔC-peptide (postprandial C-peptide minus fasting C-peptide) level were measured in all patients. RESULTS: Fasting C-peptide level, postprandial C-peptide level and ΔC-peptide level tended to be higher in patients with higher bilirubin concentrations. Partial correlation analysis showed that serum bilirubin levels were significantly correlated with fasting C-peptide level (r = 0.159, P < 0.001), postprandial C-peptide level (r = 0.209, P < 0.001) and ΔC-peptide level (r = 0.186, P < 0.001) after adjustment for other covariates. In the multivariate model, the association between serum bilirubin concentrations and serum C-peptide levels remained significant after adjustment for confounding factors including age, gender, familial diabetes, hypertension, hyperlipidaemia, BMI, HbA1c , duration of diabetes and associated liver function tests (fasting C-peptide level: ß = 0.083, P = 0.041; postprandial C-peptide level: ß = 0.106, P = 0.005; ΔC-peptide level: ß = 0.096, P = 0.015, respectively). CONCLUSIONS: Serum bilirubin concentrations within the physiological range were positively associated with serum C-peptide levels in patients with Type 2 diabetes.

Overexpression of acdS in petunia reduces ethylene production and improves tolerance to heat stress.

Petunia hybrida, widely grown as a bedding plant, has reduced growth and flower quality at temperatures above 30 °C (heat stress), primarily due to heat stress-induced ethylene (ET) production. The gene acdS encodes the 1-aminocyclopropane-1-carboxylate (ACC) deaminase (ACCD) enzyme, which is known for its role in reducing ET production by breaking down the ET precursor, ACC, in plant tissues. This study investigated the impact of heat stress on both 'Mirage Rose' WT petunia and its acdS-overexpressing transgenic lines. Heat stress-induced growth inhibition was observed in WT plants but not in transgenic plants. The increased stress tolerance of transgenic plants over WT plants was associated with lower ET production, ROS accumulation, higher SPAD values, water content, and relative water content. Furthermore, higher sensitivity of the WT to heat stress than the transgenic plants was confirmed by analysing ET signalling genes, heat shock transcription factor genes, and antioxidant- and proline-related genes, more strongly induced in WT than in transgenic plants. Overall, this study suggests the potential application of acdS overexpression in other floriculture plants as a viable strategy for developing heat stress-tolerant varieties. This approach holds promise for advancing the floricultural industry by overcoming challenges related to heat-induced growth inhibition and loss of flower quality.

Cocoa polyphenols suppress adipogenesis in vitro and obesity in vivo by targeting insulin receptor.

OBJECTIVE: To investigate the inhibitory effect of cocoa polyphenol extract (CPE) on adipogenesis and obesity along with its mechanism of action. METHODS AND RESULTS: 3T3-L1 preadipocytes were cultured with isobutylmethylxanthine, dexamethasone and insulin (MDI), and male C57BL/6N mice (N=44) were fed a high-fat diet (HFD) for 5 weeks with or without CPE. CPE at 100 or 200 µg ml(-1) inhibited MDI-induced lipid accumulation without diminishing cell viability. In particular, CPE reduced the protein expression levels of PPARγ and CEBPα, and blocked mitotic clonal expansion (MCE) of preadipocytes by reducing proliferating signaling pathways. This in turn attenuates lipid accumulation during the differentiation of 3T3-L1 preadipocytes. CPE effectively suppressed MDI-induced phosphorylation of extracellular signal-regulated kinase (ERK) and Akt, and their downstream signals. We then examined whether CPE regulates insulin receptor (IR), a common upstream regulator of ERK and Akt. We found that although CPE does not affect the protein expression level of IR, it significantly inhibits the activity of IR kinase via direct binding. Collectively, the results suggested that CPE, a direct inhibitor of IR kinase activity, inhibits cellular differentiation and lipid accumulation in 3T3-L1 preadipocytes. Consistently, CPE attenuated HFD-induced body weight gain and fat accumulation in obese mice fed with a HFD. We also found that HFD-induced increased fasting glucose levels remained unaffected by CPE. CONCLUSION: This study demonstrates that CPE inhibits IR kinase activity and its proliferative downstream signaling markers, such as ERK and Akt, in 3T3-L1 preadipocytes, and also prevents the development of obesity in mice fed with a HFD.

Evidence for a mechanism predisposing to intergenerational CAG repeat instability in spinocerebellar ataxia type I.

Spinocerebellar ataxia type I (SCAI) is an autosomal dominant neurodegenerative disease caused by the expansion of a CAG trinucleotide repeat on chromosome 6p. Normal alleles range from 19-36 repeats while SCA1 alleles contain 43-81 repeats. We now show that in 63% of paternal transmissions, an increase in repeat number is observed, whereas 69% of maternal transmissions showed no change or a decrease in repeat number. Sequence analysis of the repeat from 126 chromosomes reveals an interrupted repeat configuration in 98% of the unexpanded alleles but a contiguous repeat (CAG)n configuration in 30 expanded alleles from seven SCA1 families. This indicates that the repeat instability in SCA1 is more complex than a simple variation in repeat number and that the loss of an interruption predisposes the SCA1 (CAG)n to expansion.

Identification and characterization of the gene causing type 1 spinocerebellar ataxia.

Spinocerebellar ataxia type 1 (SCA1) is a neurodegenerative disorder caused by expansion of a CAG trinucleotide repeat. In this study, we describe the identification and characterization of the gene harbouring this repeat. The SCA1 transcript is 10,660 bases and is transcribed from both the wild type and SCA1 alleles. The CAG repeat, coding for a polyglutamine tract, lies within the coding region. The gene spans 450 kb of genomic DNA and is organized in nine exons. The first seven fall in the 5' untranslated region and the last two contain the coding region, and a 7,277 basepairs 3' untranslated region. The first four non-coding exons undergo alternative splicing in several tissues. These features suggest that the transcriptional and translational regulation of ataxin-1, the SCA1 encoded protein, may be complex.

Expansion of an unstable trinucleotide CAG repeat in spinocerebellar ataxia type 1.

Spinocerebellar ataxia type 1 (SCA1) is an autosomal dominant disorder characterized by neurodegeneration of the cerebellum, spinal cord and brainstem. A 1.2-Megabase stretch of DNA from the short arm of chromosome 6 containing the SCA1 locus was isolated in a yeast artificial chromosome contig and subcloned into cosmids. A highly polymorphic CAG repeat was identified in this region and was found to be unstable and expanded in individuals with SCA1. There is a direct correlation between the size of the (CAG)n repeat expansion and the age-of-onset of SCA1, with larger alleles occurring in juvenile cases. We also show that the repeat is present in a 10 kilobase mRNA transcript. SCA1 is therefore the fifth genetic disorder to display a mutational mechanism involving an unstable trinucleotide repeat.

Effect of high-dose vitamin C on oxygen free radical production and myocardial enzyme after tourniquet ischaemia-reperfusion injury during bilateral total knee replacement.

This study investigated the effects of high-dose vitamin C on oxygen free radical production and cardiac enzymes after tourniquet application and ischaemia-reperfusion injury during bilateral total knee replacement (TKR) in elderly patients. In the vitamin C (VC) group (VC group, n = 16), during surgery, patients received a priming bolus of 0.06 g/kg vitamin C with 100 ml saline followed by 0.02 g/kg vitamin C mixed with 30 ml saline, intravenously. The control group (n = 16) received no intra-operative vitamin C. In the VC group, malondialdehyde levels were lower, and arterial oxygen tension and mean blood pressure were higher, than in controls after post-operative deflation of both knee tourniquets. Troponin I levels were lower in the VC group than in controls 8 h post-operation. Administering high-dose vitamin C during bilateral TKR could prevent oxygen free radical production and a decline in arterial oxygen tension and mean blood pressure induced by ischaemia-reperfusion injury, thereby protecting the myocardium.

Muscle capillary basement membrane width in patients with vacor-induced diabetes mellitus.

Muscle capillary basement membrane width is a sensitive marker for the presence of diabetic microangiopathy. Studies have indicated that genetic factors and alterations in glucose metabolism influence muscle capillary basement membrane width. To define the role of these factors we have measured muscle capillary basement membrane thickness in controls, insulin dependent diabetics, and individuals with diabetes secondary to the ingestion of Vacor, a rat poison, which results in hyperglycemia. Hemoglobin A1 concentrations were increased in both diabetic groups, but hemoglobin A1 levels and the duration of diabetes were similar in the two diabetic groups. The muscle capillary basement membrane width was increased to a similar extent in the insulin-dependent diabetics (control, 1,781 +/- 46 vs. IDD, 2,287 +/- 144 A, P less than 0.001) and in the Vacor diabetic group (2,320 +/- 149 A, P less than 0.001). In the insulin-dependent diabetic group, 63% of the patients had a muscle capillary basement membrane width greater than two standard deviations above the mean of the controls, while in the Vacor diabetic group this figure was 56%. Despite the relatively short duration of diabetes (6.2 +/- 0.3 yr), 44% of the Vacor diabetic patients had retinopathy and 28% had proteinuria. The present study provides strong evidence that even in the absence of genetic diabetes mellitus, hyperglycemia or some other abnormality related to insulin lack can cause microvascular changes.

Increased risk of attention-deficit/hyperactivity disorder associated with exposure to organophosphate pesticide in Taiwanese children.

Attention-deficit/hyperactivity disorder (ADHD) is male predominated, and the etiology of this disorder remains unclear. Past studies have assessed the association of low-level organophosphate pesticide exposure with childhood ADHD cross-sectionally and prospectively. However, the results have been inconsistent. A first case-control study was performed to investigate the relationship between organophosphate pesticide exposure and ADHD with adjusted covariates. We recruited 97 doctor-diagnosed ADHD cases and 110 non-ADHD controls who were 4-15 years of age. Exposure was assessed using urinary levels of dialkylphosphate metabolites, which are biomarkers of OP pesticide exposure. Blood lead levels and polymorphisms of two commonly verified dopaminergic-related genes (the D4 dopamine receptor gene DRD4 and the dopamine transporter gene DAT1) were also analyzed. The sociodemographics and lifestyles of the children and of the mothers during pregnancy were collected using a questionnaire. The blood lead levels of both groups were similar (1.57 ± 0.73 vs. 1.73 ± 0.77 µg/dL, p = 0.15). Significant urinary concentration differences in one of the six dialkylphosphate metabolites, dimethylphosphate (DMP), were found between ADHD and control subjects (322.92 ± 315.68 vs. 224.37 ± 156.58 nmol/g cr., p < 0.01). A dose-response relationship was found between urinary concentrations of DMP and ADHD in both crude and adjusted analyses (p for trend<0.05). Children with higher urinary DMP concentrations may have a twofold to threefold increased risk of being diagnosed with ADHD. We report a dose-response relationship between child DMP levels and ADHD. Organophosphate pesticide exposure may have deleterious effects on children's neurodevelopment, particularly the development of ADHD.

Role of Ca2+ in alloxan-induced pancreatic beta-cell damage.

Pretreatment of rats with verapamil, a Ca(2+)-antagonist, completely prevented alloxan-induced hyperglycemia. Verapamil also abolished the inhibition of insulin secretion by alloxan and H2O2 in isolated rat pancreatic islets. H2O2 generation from alloxan was not affected by verapamil, but alloxan- and H2O2-induced DNA strand breaks were completely prevented. Treatment of beta-cells with alloxan and H2O2 caused elevation of cytosolic free Ca2+, and this increase of Ca2+ was also abolished by verapamil. These results suggest that alloxan-derived oxygen radicals may disturb intracellular Ca2+ homeostasis by increasing Ca2+ influx, which results in secondary reactions ultimately leading to DNA strand breaks and cytotoxicity of beta-cells.

Absence of mutations in human ubiquitin fusion-degradation protein gene in tetralogy of Fallot.

Congenital defects in human chromosome 22q11 deletion syndromes are associated with the 3rd and 4th pharyngeal pouch during fetal development. In the cardiovascular system, these disorders are usually apparent as conotruncal heart defects and aortic arch anomalies. UFD1L, a gene that is downregulated in dHAND-deficient mice, expressed in the mouse embryo at the branchial arch and mapped to human chromosome 22q11, has recently been strongly suspected to be responsible for the phenotypes expressed in 22q11 deletion syndromes. Its putative causal role in relevant congenital cardiovascular malformations was studied by gene dosage analysis, mutation screening and sequence analyses. Sixty cases of tetralogy of Fallot with no detectable chromosome deletion at 22q11 or 10p13 were examined, including 51 cases of simple tetralogy of Fallot, and 9 cases of tetralogy of Fallot with pulmonary atresia. None of these patients revealed deletion limited to a portion of the UFD1L gene. Although mobility shift was found by heteroduplex analysis in 24 cases at exon 4 and flanking sequences, further sequence analysis demonstrated only two silent nucleotide variations and a single nucleotide polymorphism in intron 4. Our data suggest that, although the UFD1L gene is mapped to 22q11 and is expressed during early murine development at both cardiac and cranial neural crests, it is not responsible for the majority of tetralogy of Fallot cases in humans.

Serum Cystatin C Levels are Positively Associated with Cardiovascular Autonomic Neuropathy in Patients with Type 2 Diabetes.

AIMS: Previous studies have reported that cystatin C is associated with degenerative disorder in the nervous system. However, the relationship between serum cystatin C concentrations and cardiovascular autonomic neuropathy (CAN) in patients with type 2 diabetes is currently unknown. The aim of this study was to assess the relationships between serum cystatin C levels and CAN in patients with type 2 diabetes. METHODS: A total of 357 patients with type 2 diabetes were studied in this cross-sectional study. CAN was diagnosed by a cardiovascular autonomic reflex test. According to the American Diabetes Association criteria, the degree of cardiovascular autonomic dysfunction was graded as normal, early, definite, or severe. CAN was either definite or severe in the subjects of the present study. RESULTS: Serum cystatin C concentrations were significantly higher in patients with CAN than in those without CAN. The mean cystatin C levels differed significantly according to the degree of cardiovascular autonomic dysfunction (normal, 0.78 mg/l; early, 0.79 mg/l; definite, 0.87 mg/l; severe, 0.90 mg/l; P for trend=0.021) after adjustment for other covariates. In multivariate analysis, serum cystatin C levels were significantly associated with CAN (odds ratio [OR] of each standard deviation increase in the logarithmic value, 5.25; 95% confidence interval [CI], 1.17-23.70, P=0.025). CONCLUSIONS: Serum cystatin C levels are positively associated with CAN in patients with type 2 diabetes.

Systematic mutation analysis of the catechol O-methyltransferase gene as a candidate gene for schizophrenia.

OBJECTIVE: Catechol O-methyltransferase (COMT) is involved in the degradation of catecholamine neurotransmitters. Recent linkage studies of schizophrenia and molecular studies of velocardiofacial syndrome suggest that the COMT gene might be a candidate gene for schizophrenia. METHOD: The authors systematically searched for mutations and microdeletion of the COMT gene in 177 Chinese schizophrenic patients from Taiwan; 99 comparison subjects were also studied. RESULTS: Five molecular variants were identified: c.186C > T at exon 3, c.408C > G at exon 4, c.472G > A at exon 4, c.597G > A at exon 5, and c.821-827insC at the 3' untranslated region. However, no differences in the genotype and haplotype frequencies of these molecular variants between the schizophrenic and comparison subjects were detected. Furthermore, no microdeletion was identified among the patients. CONCLUSIONS: These data suggest that the COMT gene does not play a major role in the pathogenesis of schizophrenia, and the genotypic overlap between schizophrenia and velocardiofacial syndrome was rare in this cohort.

Prevalence and parental origin in Tetralogy of Fallot associated with chromosome 22q11 microdeletion.

OBJECTIVE: Tetralogy of Fallot is a common cardiac anomaly that is associated with chromosome 22q11 microdeletion. In this study we examined the mode of transmission as well as the parental origin of microdeletion in patients with tetralogy of Fallot. METHODS: Eighty-four children with sporadic tetralogy of Fallot (40 boys and 44 girls; mean age, 34 months) were analyzed for microdeletion at chromosome 22q11 by genotype analysis, using five microsatellite markers, D22S427, D22S941, D22S944, D22S264 and D22S311, and confirmed by quantitative polymerase chain reaction, using TUPLE1 and D22S264. All parents of these subjects consented to their own participation and their child's participation in the clinical evaluation and molecular study. To provide a molecular characterization of microdeletion, we isolated DNA from the parents and typed their DNA with each of the five polymorphic markers. RESULTS: Sixty-six patients were associated with pulmonary stenosis; and 8 of these cases (12%) had microdeletion. Eighteen patients were associated with pulmonary atresia, and 6 (33%) of these cases had microdeletion. The parental origins of the 14 patients with microdeletion were paternal in 3 cases and maternal in 11 cases. The most common mode of transmission was de novo without parental hemizygosity (93%). Transmission by autosomal dominant heredity was uncommon (7%). CONCLUSIONS: Biased parental origin was consistently found in tetralogy of Fallot patients with chromosomal 22q11 microdeletion. Our results indicated a higher prevalence of microdeletion because of inheritance of maternal microdeletion (78%).

Increased vascular endothelin-1 gene expression with unaltered nitric oxide synthase levels in fructose-induced hypertensive rats.

The present study aimed to investigate whether altered expression levels of endothelin-1 (ET-1) and nitric oxide synthase (NOS) are related to the development of insulin-resistant hypertension. Male Sprague-Dawley rats were fed a fructose-rich diet for 5 weeks. Systolic blood pressure significantly increased in fructose-fed rats. While serum free fatty acid (FFA) and plasma nitrite/nitrate (NOx) levels did not significantly differ between the fructose-fed and control groups, plasma insulin and serum triglyceride (TG) concentrations significantly increased in the former. ET-1 mRNA expression in the aorta increased to 195% in fructose-fed rats. Neither the protein expression of constitutive NOS (cNOS) nor that of inducible NOS (iNOS) were significantly affected by fructose feeding. However, NOx levels in the aorta were significantly increased. These results indicate that an increased expression of vascular ET-1 may be causally related to the development of hypertension in fructose-fed rats. However, an altered role of the vascular nitric oxide (NO) pathway may not be primarily involved in the development of fructose-induced hypertension.

Determination of serum catalase activity on a centrifugal analyzer by an NADP/NADPH coupled enzyme reaction system.

We developed a simple, kinetic method for the determination of catalase activity in which i) the enzyme catalyzes the peroxidation of ethanol by hydrogen peroxide to acetaldehyde and water, and ii) the acetaldehyde so formed is rapidly oxidized to acetic acid and NADPH by the addition of an excess of NADP+ and aldehyde dehydrogenase. The rate of NADPH production was monitored at 340 nm in a COBAS centrifugal analyzer. The reaction was linear to 800 U/L or a delta A of 0.020/min. Using human serum pools containing 80 and 460 U/L of peroxidase activity, the within-run coefficients of variation (CV) were 1.9 and 1.3%, respectively. Between-run CV values were 5% for both pools. The reference range for sera from 72 males and 52 females was 23 to 158 U/L (mean + 2 SD) by log normal transformation. The activity in red cells was 600 U/g hemoglobin but did not change the reference range appreciably provided that serum without visible hemolysis was used. Preliminary observations on sera from nine patients with various pancreatic disorders showed a poor correlation between the activities of catalase (peroxidase) and amylase in serum. The reasons for this discrepancy are under investigation.