Abstract-Central sympathoexcitation is involved in the pathogenesis of salt-sensitive hypertension. We have suggested that oxidative stress in the brain modulates the sympathetic regulation of arterial pressure. Thus, we investigated whether oxidative stress could mediate central sympathoexcitation in salt-sensitive hypertension. Five-to 6-week-old male Dahl salt-sensitive rats and salt-resistant rats were fed with a normal (0.3%) or high-(8%) salt diet for 4 weeks. In urethane-anesthetized and artificially ventilated rats, arterial pressure, renal sympathetic nerve activity, and heart rate decreased in a dose-dependent fashion, when 20 or 40 mol of tempol, a membrane-permeable superoxide dismutase mimetic, was infused into the lateral cerebral ventricle. The same degree of reduction was noted in salt-sensitive and salt-resistant rats without salt loading. Salt loading significantly increased central tempol-induced reductions in arterial pressure (Ϫ29.1Ϯ4.8% versus Ϫ10.6Ϯ3.3% at 40 mol; PϽ0.01), sympathetic nerve activity (Ϫ18.7Ϯ2.0% versus Ϫ7.1Ϯ1.8%; PϽ0.01), and heart rate (Ϫ10.7Ϯ2.8% versus Ϫ2.0Ϯ0.7%; PϽ0.05) in salt-sensitive rats but not in salt-resistant rats. Intracerebroventricular diphenyleneiodonium, a reduced nicotinamide-adenine dinucleotide phosphate oxidase inhibitor, also elicited significantly greater reduction in each parameter in salt-loaded salt-sensitive rats. Moreover, salt loading increased reduced nicotinamide-adenine dinucleotide phosphate-dependent superoxide production in the hypothalamus in salt-sensitive rats but not in salt-resistant rats. In addition, reduced nicotinamide-adenine dinucleotide phosphate oxidase subunits p22 phox , p47 phox , and gp91 phox mRNA expression significantly increased in the hypothalamus of salt-loaded salt-sensitive rats. In conclusion, in salt-sensitive hypertension, increased oxidative stress in the brain, possibly via activation of reduced nicotinamide-adenine dinucleotide phosphate oxidase, may elevate arterial pressure through central sympathoexcitation. Key Words: salt-sensitive hypertension Ⅲ oxidative stress Ⅲ brain Ⅲ hypertension Ⅲ salt Ⅲ sympathetic nervous system Ⅲ Dahl rat S ubstantial findings indicate that abnormal modulation of the sympathetic nervous system may be involved in salt-induced development of hypertension in humans 1 and animals. [2][3][4][5][6] In our previous study, 2 salt loading impaired the arterial baroreceptor reflex associated with abnormal central properties in spontaneously hypertensive rats (SHRs); the sympathetic nerve activity (SNA) was less inhibited by stimulation of the aortic depressor nerve in salt-loaded SHRs. However, salt loading did not affect the SNA in Wistar-Kyoto rats. Similarly, the SNA was augmented with salt loading in Dahl salt-sensitive rats (DSs), but not in Dahl salt-resistant rats (DRs). 3 Intracerebroventricular (ICV) infusion of sodium caused sympathoexcitatory and pressor responses to a greater degree in DSs than in DRs. 4 Thus, central sympathetic activation may be involved in salt-sensitive ...

The purpose of this study was to evaluate the long-term durability of in vivo bond strengths and the morphological changes of interfaces between dentin and two adhesive systems. Class V preparations were prepared on the facial surfaces of 14 intact teeth of two monkeys and restored with a combination of Unifil Bond/Z250 or Single Bond/Z250. One year later, 10 additional teeth were restored with the same materials and the monkeys were killed after 24 h. All of the restored teeth were subjected to microtensile bond strength ( micro TBS) testing. The debonded surfaces of the dentin sides were morphologically observed using Fe-scanning electron microscopy (SEM), as were the polished cross-sections of resin-dentin interfaces. For both Unifil Bond and Single Bond, the micro TBS at 24 h was significantly higher than that at 1 yr. Fe-SEM observations of polished cross-sectioned and fractured surfaces showed that porosity within the hybrid layers produced by Single Bond increased over time. However, the interface produced by Unifil Bond revealed no noticeable changes in morphology between 24-h and 1-yr specimens. It is concluded that even though the bond strengths of both adhesive systems declined over time, the bonding interface using self-etching primers was relatively stable over time compared to the wet bonding system.

Background-Obesity is one of the major risk factors for cardiovascular disease and is often associated with increased oxidative stress and sympathoexcitation. We have already suggested that increased oxidative stress in the brain modulates the sympathetic regulation of arterial pressure in salt-sensitive hypertension, which is often associated with obesity. The present study was performed to determine whether oxidative stress could mediate central sympathoexcitation in the initial stage of obesity-induced hypertension. Methods and Results-Four-week-old male Sprague-Dawley rats were fed a high-fat (45% kcal as fat) or low-fat (10% kcal as fat) diet for 6 weeks. Fat loading elicited hypertension and sympathoexcitation, along with visceral obesity. In urethane-anesthetized and artificially ventilated rats, arterial pressure and renal sympathetic nerve activity decreased in a dose-dependent fashion when 53 or 105 mol/kg tempol, a membrane-permeable superoxide dismutase mimetic, was infused into the lateral cerebral ventricle. Central tempol reduced arterial pressure and renal sympathetic nerve activity to a significantly greater extent in high-fat diet-fed hypertensive rats than in low-fat diet-fed normotensive rats. Intracerebroventricular apocynin or diphenyleneiodonium, a reduced NADPH oxidase inhibitor, also elicited markedly greater reductions in arterial pressure and renal sympathetic nerve activity in the high-fat diet-fed rats. In addition, fat loading increased NADPH oxidase activity and NADPH oxidase subunit p22 phox , p47 phox , and gp91 phox mRNA expression in the hypothalamus. Key Words: brain Ⅲ hypertension Ⅲ obesity Ⅲ oxidative stress Ⅲ sympathetic nervous system M etabolic syndrome, a complex of highly debilitating disorders that consist of hypertension, diabetes mellitus, and dyslipidemia, is associated with the development of visceral obesity. 1 All of these features are risk factors for atherosclerosis; therefore, the metabolic syndrome results in a high incidence of cardiovascular events. Although hypertension is one of the major components of the metabolic syndrome, the mechanisms through which obesity contributes to hypertension have not been fully elucidated. Conclusions-In Clinical Perspective p 986Sympathetic activation is often associated with obesity. For example, studies using microneurography have consistently shown increased muscle sympathetic nerve activity in obese subjects. 2 Furthermore, muscle sympathetic nerve activity is closely associated with the level of abdominal visceral fat. 3 As expected, a number of studies indicated that sympathetic activation may be involved in obesity-induced hypertension. 4 In young, nondiabetic Japanese men, body mass index correlated with not only mean blood pressure but also pulse rate and plasma norepinephrine. 5 In an animal study, obese Zucker rats, which display hyperphagia-induced obesity caused by a mutation of the leptin receptor, have elevated sympathetic nerve activity and arterial pressure (AP). 6 Autonomic ganglionic blockade decreased m...

There have been several clinical studies examining the factors associated with cardiovascular disease (CVD) in patients with primary aldosteronism (PA); however, their results have left it unclear whether CVD is affected by the plasma aldosterone concentration or hypokalemia. We assessed the PA database established by the multicenter JPAS (Japan Primary Aldosteronism Study) and compared the prevalence of CVD among patients with PA with that among age-, sex-, and blood pressure-matched essential hypertension patients and participants with hypertension in a general population cohort. We also performed binary logistic regression analysis to determine which parameters significantly increased the odds ratio for CVD. Of the 2582 patients with PA studied, the prevalence of CVD, including stroke (cerebral infarction, cerebral hemorrhage, or subarachnoid hemorrhage), ischemic heart disease (myocardial infarction or angina pectoris), and heart failure, was 9.4% (stroke, 7.4%; ischemic heart disease, 2.1%; and heart failure, 0.6%). The prevalence of CVD, especially stroke, was higher among the patients with PA than those with essential hypertension/hypertension. Hypokalemia (K ≤3.5 mEq/L) and the unilateral subtype significantly increased adjusted odds ratios for CVD. Although aldosterone levels were not linearly related to the adjusted odds ratio for CVD, patients with plasma aldosterone concentrations ≥125 pg/mL had significantly higher adjusted odds ratios for CVD than those with plasma aldosterone concentrations <125 pg/mL. Thus, patients with PA seem to be at a higher risk of developing CVD than patients with essential hypertension. Moreover, patients with PA presenting with hypokalemia, the unilateral subtype, or plasma aldosterone concentration ≥125 pg/mL are at a greater risk of CVD and have a greater need for PA-specific treatments than others.

Previous studies have classified a series of nonheme iron catalysts for olefin cis-dihydroxylation by H2O2 into two groups. Complex 1, [(TPA)Fe(OTf)2], representative of Class A catalysts, forms a low-spin FeIII-OOH intermediate that gives rise to a high-valent FeV(=O)OH oxidant. The preference of this catalyst for electron-rich olefins demonstrates its electrophilic character. On the other hand, complex 2, [(6-Me3-TPA)Fe(OTf)2], representative of Class B catalysts, prefers instead to oxidize electron-deficient olefins, suggesting an oxidant with nucleophilic character. It is suggested that such a nucleophilic oxidant may be the high-spin FeIII-OOH intermediate derived from 2 or the FeIV(=O)(*OH) species derived therefrom.

The FTA card (Whatman) was assessed for its utility as a molecular epidemiological tool in collecting samples from patients with leishmaniasis in Peru because the card has a variety of merits; it is less invasive for patients and easy to handle for both physicians and other medical personnel for sample collection or diagnosis, in addition to its simplicity and easy countrywide and/or intercountry transportation for analysis.

Abstract-We reported previously that ATP2B1 was one of the genes for hypertension receptivity in a large-scale Japanese population, which has been replicated recently in Europeans and Koreans. ATP2B1 encodes the plasma membrane calcium ATPase isoform 1, which plays a critical role in intracellular calcium homeostasis. In addition, it is suggested that ATP2B1 plays a major role in vascular smooth muscle contraction. Because the ATP2B1 knockout (KO) mouse is embryo-lethal, we generated mice with vascular smooth muscle cell-specific KO of ATP2B1 using the Cre-loxP system to clarify the relationship between ATP2B1 and hypertension. The KO mice expressed significantly lower levels of ATP2B1 mRNA and protein in the aorta compared with control mice. KO mice showed significantly higher systolic blood pressure as measured by tail-cuff method and radiotelemetric method. Similar to ATP2B1, the expression of the Na 1 In the Millennium Genome Project 2 we identified single nucleotide polymorphisms located upstream or within the ATP2B1 gene as strong susceptible polymorphisms for hypertension in Japanese. Some of these findings have been replicated in individuals of European descent in the Global Blood Pressure Genetics sample and have also been validated in other studies in individuals of European descent, 3 Koreans, 4-6 and Japanese. 7 The single nucleotide polymorphisms of ATP2B1 identified in these studies showed a significant association with hypertension in various large-scale study populations with different methods, genome-wide association study in the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium and the Korean study and candidate gene analysis in our previous study. However, the functional roles of ATP2B1 in blood pressure control have not yet been proven in vivo. The ATP2B1-null mutant mouse has been reported to be embryolethal 8 ; thus, we need to make a conditional knockout (KO) mouse model of ATP2B1 using the Cre-loxP system to reveal the function of the gene. Because the ATP2B1 gene encodes one of the calcium pumps and plays an important role in contraction of bladder smooth muscle, 9 we selected vascular smooth

). Based on the discovery that artificial insertion of pre-miRNAs in introns did not hamper mRNA production and that the miRNA-harboring introns were spliced more slowly than the adjacent introns, a model was previously proposed in which Drosha crops the pre-miRNA and the two cropped fragments from the pre-mRNA are subsequently trans spliced (Y. K. Kim and V. N. Kim, EMBO J. 26:775-783, 2007). However, the molecular basis for this model was not elucidated. To analyze the molecular mechanism of intronic miRNA processing, we developed an in vitro system in which both pre-miRNA processing and mRNA splicing are detected simultaneously. Our analysis using this system showed that pre-miRNA cropping from the pre-mRNA could occur kinetically faster than splicing. Glycerol gradient sedimentation experiments revealed that part of the pre-miRNA was cofractionated with the spliceosome. Furthermore, coimmunoprecipitation experiments with an anti-Drosha antibody demonstrated that Drosha was associated not only with the cropping products but also with a Y-shaped branch intron and a Y-shaped splicing intermediate. These results provide a molecular basis for the postulated existence of a pathway in which the Microprocessor complex becomes associated with the spliceosome, pre-miRNA cropping occurs prior to splicing, and trans splicing takes place between the cropped products.MicroRNAs (miRNAs) are short, noncoding RNAs that mediate posttranscriptional gene silencing via base pairing with their target mRNAs (for reviews, see references 7, 23, and 24). The majority of miRNAs are transcribed by RNA polymerase II (31) and matured through several processing steps in both the nucleus and cytoplasm (6,30,31). Primary miRNA transcripts (pri-miRNAs) are cleaved by Drosha, an RNase III-type enzyme in the nucleus (29). Drosha functions in the context of a large protein complex, termed the Microprocessor complex, that also contains DGCR8/Pasha as well as several splicing factors (8,11,13,28). Cleavage of pri-mRNAs by the Microprocessor complex results in the production of short, stem-loop-shaped RNAs called pre-miRNAs. These RNAs are subsequently exported to the cytoplasm by exportin 5 (5, 32, 52). In the cytoplasm, pre-miRNAs are cleaved by the cytoplasmic RNase III-type enzyme Dicer (4,12,16,20,26). The cleavage reaction, referred to as dicing, yields short RNA duplexes and, subsequently, incorporation of one strand of each duplex into the RNA-induced silencing complex (21, 46). The RNA-induced silencing complex binds to its target mRNAs through base pairing with the 3Ј untranslated regions and induces translational repression, mRNA cleavage, or mRNA degradation (42,49).Most miRNAs were formerly thought to have their own transcriptional units in the intergenic regions. However, recent studies revealed that about 80% of miRNAs are encoded in the intronic regions of protein-encoding or noncoding genes in mammals (25,43) and that this number is 75% in Xenopus tropicalis (48), implying that the phenomenon of the majority of miRNAs being encode...