BACKGROUND AND OBJECTIVES: Coronary flow reserve (CFR) is the capability of coronary arteriolar bed to dilate in response to increased cardiac metabolic demand. Nocorandil, a hybrid of ATP-sensitive K+ channel opener and nitrates, causes coronary vasodilation of both epicardial and resistance vessels. We investigated the feasibility and safety of nicorandil as compared to adenosine in the measurement of CFR using a Doppler guide wire. SUBJECTS AND METHODS: We measured CFR in 26 consecutive patients (mean age 52+/-19 years, M:F=16:10) during coronary intervention with a 0.014-inch Doppler guide wire. We recorded the baseline average peak velocity (APV) and the hyperemic APV induced by intracoronary adenosine or nicorandil. The heart rate, mean aortic pressure and the time interval from maximal APV to baseline APV were also recorded. RESULTS: There were no significant differences between APV, diastole/systole velocity ratio and CFR induced by adenosine and those induced by nicorandil (44.4 +/- 17.3 vs 45.5 +/- 17.6, p=0.78, 1.59 +/- 0.51 vs 1.57 +/- 0.52 p=0.78, 2.22 +/- 0.89 vs 2.27 +/- 0.94, p=0.36). The CFR and diastole/systole velocity ratio induced by nicorandil showed a strong positive linear correlation with those by adenosine (r2=0.77, p=0.0001, r2=0.83, p=0.0001). Adenosine significantly decreased the heart rate as compared to nicorandil =-25.5 +/- 9.7 vs -8.7 +/- 4.9 bpm, p=0.001). There were no differences in the changes of mean aortic pressure between adenosine and nicorandil (-7 +/- 9 vs -2 +/- 3 mmHg, p=0.17). Nicorandil prolonged the time interval from maximal APV to baseline APV compared to adenosine (194 +/- 62 vs 37 +/- 12 sec, p=0.001). CONCLUSION: Nicorandil is feasible and safe for use in measuring CFR using a Doppler guide wire and may replace adenosine.
Adenosine* ; Arterial Pressure ; Blood Flow Velocity ; Heart Rate ; Humans ; Nicorandil* ; Nitrates ; Ultrasonography ; Vasodilation

Nitrate - was an indicator on sanitary quality for drinking water. Basing on foreign documents and results in the own country researches, this paper introduced some discussions on the concentration of nitrate in drinking water as a sanitary standard.
Sanitary Engineering ; water ; Nitrates

The average incidence/case/year of Ha Bac nitrate and chemical factory during two years (2002-2003) was 1.38 incidence/case/year (2002) and 1.63 incidence/case/year (2003). The diseases were high incidence as follows: odonto-maxial-facial disease, ear-nose-throat disease. Workers with I health level and II health level were the highest: 70.33% (2002) and 65.05% (2003). The rate of workers with III health level were very high and tend to increase, remained the rate of workers with V health level.
Health ; Nitrates ; Chemical Industry

Coronary spasm may be induced by a variety of physiologic and pharmacologic stimuli but specific receptor blockade has not been consistently shown to prevent the attacks. Most patients with variant angina respond well to treatment with calcium antagonists and nitrates. A small proportion of patients are refractory to this therapy. We report a case of the patient with a 9-year-history of variant angina who has been refractory to high doses of calcium antagonists and nitrates. The repeated addition of clonidine was consistently effective in abolishing both symptoms and objective evidence of myocardial ischemia in this particular patient.
Calcium ; Clonidine* ; Humans ; Myocardial Ischemia ; Nitrates ; Spasm

Biological denitrification is the most widely used technology for nitrate removal in wastewater treatment. Conventional denitrification requires long hydraulic retention time, and the nitrate removal efficiency in winter is low due to the low temperature. Therefore, it is expected to develop new approaches to enhance the denitrification process. In this paper, the effect of adding different concentrations of Fe₃O₄ nanoparticles on the denitrification catalyzed by Pseudomonas stutzeri was investigated. The maximum specific degradation rate of nitrate nitrogen improved from 18.0 h⁻¹ to 23.7 h⁻¹ when the concentration of Fe₃O₄ increased from 0 mg/L to 4 000 mg/L. Total proteins and intracellular iron content also increased along with increasing the concentration of Fe₃O₄. RT-qPCR and label-free proteomics analyses showed that the relative expression level of denitrifying genes napA, narJ, nirB, norR, nosZ of P. stutzeri increased by 55.7%, 24.9%, 24.5%, 36.5%, 120% upon addition of Fe₃O₄, and that of denitrifying reductase Nap, Nar, Nir, Nor, Nos increased by 85.0%, 147%, 16.5%, 47.1%, 95.9%, respectively. No significant difference was observed on the relative expression level of denitrifying genes and denitrifying reductases between the bacteria suspended and the bacteria adhered to Fe₃O₄. Interestingly, the relative expression level of electron transfer proteins of bacteria adhered to Fe₃O₄ was higher than that of the bacteria suspended. The results indicated that Fe₃O₄ promoted cell growth and metabolism through direct contact with bacteria, thereby improving the denitrification. These findings may provide theoretical support for the development of enhanced denitrification.
Aerobiosis ; Denitrification ; Nitrates ; Nitrogen ; Pseudomonas stutzeri/genetics*

The denitrifier method is widely used as a novel pretreatment method for the determination of nitrogen and oxygen isotope ratios as it can provide quantitative and high-sensitivity measurements. Nevertheless, the method is limited by relatively low measurement accuracy for δ18O. In this study, we analyzed the factors influencing the accuracy of δ18O determination, and then systematically investigated the effects of dissolved oxygen concentrations and nitrate sample sizes on estimates of the δ15N and δ18O of nitrate reference materials. The δ18O contraction ratio was used to represent the relationship between the measured difference and true difference between two reference materials. We obtained the following main results: (1) a gas-liquid ratio of 3:10 (v/v) in ordinary triangular flasks and a shaking speed of 120 r/min produced an optimal range (1.9 to 2.6 mg/L) in the concentration of dissolved oxygen for accurately determining δ18O, and (2) the δ18O contraction ratio decreased as nitrate sample size decreased within a certain range (1.0 to 0.1 μmol). Our results suggested that δ18O contraction is influenced mainly by dissolved oxygen concentrations in pure culture, and provided a model for improving the accuracy of oxygen isotope analysis.
Denitrification ; Nitrates/analysis* ; Oxygen Isotopes/analysis*

OBJECTIVE: To investigate if salivary nitrate correlates to the daily psychological stress and anxiety in a group of human subjects. METHODS: The convenient sample recruitment method was employed; data from seventy three subjects were analyzed. The Perceived Stress Scale (PSS) and Hamilton Anxiety Rating Scale (HAM-A) inventories were used to determine stress and anxiety scores respectively. Salivary nitric oxide was measured through nitrate (NOx) levels using the Griess reaction method. RESULTS: Although stress and anxiety were correlated. No significant correlation exists between salivary nitrate and daily psychological stress and anxiety in the study's participants. CONCLUSION: While all previous studies focused NOx levels in acute stress models. This is the first study to investigate the correlation between salivary nitrates and daily psychological stress and anxiety. Although stress and anxiety were correlated, there is no correlation between salivary nitrates and daily psychological stress and anxiety. Further studies are required to investigate this correlation using other biological samples such as plasma.
Anxiety* ; Equipment and Supplies ; Humans ; Nitrates ; Nitric Oxide* ; Plasma ; Stress, Psychological

OBJECTIVE: To construct a modABC gene knockout strain of Proteus mirabilis and explore the effect of modABC gene deletion on biological characteristics of Proteus mirabilis. METHODS: Fusion PCR was used to obtain the fusion gene of modABC and the kanamycin-resistant gene Kn, which was ligated with the suicide vector pCVD442 and transduced into Proteus mirabilis. The modABC gene knockout strain of Proteus mirabilis was obtained after homologous recombination with the suicide vector. PCR and Sanger sequencing were used to identify genomic deletion of modABC gene in the genetically modified strain. The concentration of molybdate in the wild-type and gene knockout strains was determined using inductively coupled plasma mass spectrometry (ICP-MS), and their survival ability in LB medium was compared under both aerobic and anaerobic conditions. RESULTS: PCR and sanger sequencing confirmed genomic deletion of modABC gene in the obtained Proteus mirabilis strain. The concentration of intracellular molybdenum in the modABC gene knockout strain was 1.22 mg/kg, significantly lower than that in the wild-type strain (1.46 mg/kg, P < 0.001). Under the aerobic condition, the modABC gene knockout strain grown in LB medium showed no significant changes in survival ability compared with the wild-type strain, but its proliferation rate decreased significantly under the anaerobic condition and also when cultured in nitrate-containing LB medium under anaerobic condition. CONCLUSION Homologous recombination with the suicide vector can be used for modABC gene knockout in Proteus mirabilis. modABC gene participates in molybdate uptake and is associated with anaerobic growth of Proteus mirabilis in the presence of nitrate.
Humans ; Gene Deletion ; Nitrates ; Proteus mirabilis/genetics* ; Gene Knockout Techniques

Homeostasis is a dynamic balance process of self-regulating. Biological systems remain stable through adapting to changing external conditions to maintain normal life activities. Homeostatic medicine is the science of studying homeostasis of human molecules, cells, organs and the whole body. It is a comprehensive discipline based on maintaining homeostasis to keep human health and assist for diseases prevention and diagnoses. Homeostatic medicine focuses on the whole body and on the role of homeostasis in health and disease, which is expected to provide new ideas and strategies for maintaining health as well as diagnosing and treating diseases. Nitric oxide (NO) plays an important role in the control of multisystem homeostasis. Nitrate is an important substance in regulating NO homeostasis through the nitrate-nitrite-NO pathway. Sialin, nitrate transporter which is located in the cell membrane and cytoplasm, mediates multiple cellular biological functions. The nitrate-nitrite-NO pathway and sialin-mediated biological functions play an important role in the regulation of body homeostasis.
Humans ; Nitrates/metabolism* ; Nitrites/metabolism* ; Homeostasis ; Nitric Oxide

No data are available on the association of serum uric acid and vasospastic angina (VSA) which has endothelial dysfunction as a possible pathophysiologic mechanism. Low uric acid level might cause adverse outcomes in VSA in connection with endothelial dysfunction. We enrolled 818 VSA patients whose uric acid level was measured at admission. Patients were categorized according to tertiles of uric acid level: group I, ≤ 4.8 mg/dL; group II, 4.9–5.9 mg/dL; and group III, ≥ 6.0 mg/dL. Primary outcome was major adverse cardiac events (MACEs), defined as a composite of cardiac death, acute myocardial infarction (MI), ischemic stroke, coronary revascularization, and rehospitalization for angina. Median follow-up duration was 49.2 months. Median uric acid values were 4.1 mg/dL for group I, 5.4 mg/dL for group II, and 6.7 mg/dL for group III. In the overall population, group II had a significantly lower incidence of MACE compared to group I (47 [17.1%] vs. 66 [24.6%]; hazard ratio [HR], 1.52; 95% confidence interval [CI], 1.02–2.26; P = 0.040) and a tendency of lower incidence of MACEs compared to Group III (47 [17.1%] vs. 62 [22.5%]; HR, 1.44; 95% CI, 0.98–2.13; P = 0.067). Among group I patients, those who received nitrates had a higher incidence of MACEs than those without nitrate therapy (P < 0.001). Low uric acid level was associated with adverse clinical outcomes, while high uric acid level had a trend toward an increase in it. Use of nitrate in patients with low uric acid level might have adverse effects on clinical outcomes of VSA.
Death ; Follow-Up Studies ; Humans ; Incidence ; Myocardial Infarction ; Nitrates ; Stroke ; Uric Acid*