Nitrite and Nitrate Analyses: A Clinical Biochemistry Perspective

Ellis, Graham; Adatia, Ian; Yazdanpanah, Mehrdad; Makela, Sinikka K.

doi:10.1016/s0009-9120(98)00015-0

Cited by 243 publications

(228 citation statements)

References 376 publications

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“…Better analytical tools are required in clinical diagnosis, monitoring of food quality and pollution control because none of the established protocols meet all requisites we demand of an analytical assay: simplicity, sensitivity, selectivity, low detection limit, reproducibility and fast response time [1][2][3][4].…”

Section: Introductionmentioning

confidence: 99%

“…A good example are the colorimetric tests strips routinely used for detecting nitrite in urine, which may correlate well with urinary tract infections. But despite being easy-to-use, quick and inexpensive, results provided by the indicator strips are merely qualitative as they are obtained by visual comparison to a color chart [2]. Nitrite quantification in plasma and blood has been gaining an increasing value in biomedical research.…”

Section: Introductionmentioning

confidence: 99%

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Construction of effective disposable biosensors for point of care testing of nitrite

Monteiro

Rodrigues

Gonçalves

et al. 2015

Talanta

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In this paper we aim to demonstrate, as a proof-of-concept, the feasibility of the mass production of effective point of care tests for nitrite quantification in environmental, food and clinical samples. Following our previous work on the development of third generation electrochemical biosensors based on the ammonia forming nitrite reductase (ccNiR), herein we reduced the size of the electrodes' system to a miniaturized format, solved the problem of oxygen interference and performed simple quantification assays in real samples. In particular, carbon paste screen printed electrodes (SPE) were coated with a ccNiR/carbon ink composite homogenized in organic solvents and cured at low temperatures. The biocompatibility of these chemical and thermal treatments was evaluated by cyclic voltammetry showing that the catalytic performance was higher with the combination acetone and a 40 °C curing temperature.The successful incorporation of the protein in the carbon ink/solvent composite, while 2 remaining catalytically competent, attests for ccNiR's robustness and suitability for application in screen printed based biosensors.Because the direct electrochemical reduction of molecular oxygen occurs when electroanalytical measurements are performed at the negative potentials required to activate ccNiR (ca. -0.4 V vs Ag/AgCl), an oxygen scavenging system based on the coupling of glucose oxidase and catalase activities was successfully used. This enabled the quantification of nitrite in different samples (milk, water, plasma and urine) in a straightforward way and with small error (1 -6%). The sensitivity of the biosensor towards nitrite reduction under optimized conditions was 0.55 A M -1 cm -2 with a linear response range 0.7 -370 µM.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Construction of effective disposable biosensors for point of care testing of nitrite

Monteiro

Rodrigues

Gonçalves

et al. 2015

Talanta

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“…About 10 mL venous blood was aspirated before and after exercise treadmill test in the morning for measuring F2-isoprostane level with competitive enzyme-linked immunoassay (ELISA kit, Oxford Biomedical Research Inc., Rochester Hills, MI) [25][26][27] and NO were measured with Griess reagent and spectrophotometry, as previously described. 28,29 Treatment with any cardiovascular medications was discontinued for at least 24 hours and fasting at least 12 hours at night before exercise treadmill test in the morning.…”

Section: Study Protocolmentioning

confidence: 99%

“…The aim of this study was to evaluate the effects of shortterm low-intensity exercise training on various clinical parameters as well as molecular parameters, such as plasma F2-isoprostane (an accurate and specific marker of ROS) [25][26][27] and plasma nitrite and nitrate production (the marker of NO) 28,29 in patients with AMI.…”

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confidence: 99%

Effect of Short-Term Low-Intensity Exercise Training on Association of Oxygen Free Radicals and Nitric Oxide Production in Patients with Acute Myocardial Infarction

et al. 2013

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Oxygen, although is highly required for living, can be toxic because it can be easily changed into oxygen free radicals (reactive oxygen species, ROS) and generates oxidative stress. [1][2][3][4][5] This oxidative stress will cause endothelial lesion and will be responded by endothelial cells through nitric oxide (NO) response and immunological response pathway. 6-8 The immunological response begins by increasing cytokines production, activated coagulation factors, and reactivation of platelet in acute thrombotic process. However, acute thrombotic process, which is an initial part of protective mechanism to fix the lesion, often change to become continuous process because of abundance oxidative stress, and then generates various levels of acute coronary syndromes. 3,5 Several studies showed that acute exercise on treadmill test with high intensity Bruce protocol increased oxidative stress because of ROS. 9,10 On the contrary, acute exercise also increased production of NO because of the increment effect of shear stress on endothelial cells. 6,9-15 But, regular exercise Keywords ► acute coronary syndrome ► atherosclerosis ► cardiovascular risk factors ► myocardial infarction ► oxidative stress ► nitric oxide ► cardiac markers ► exercise AbstractModerate-to-high intensity of exercise training within 2 to 3 months decreases oxygen free radicals (reactive oxygen species, ROS) and increases nitric oxide (NO) in outpatients with myocardial infarction. There is no data about the association of ROS and NO after short-term low-intensity exercise training within 5 days in patients hospitalized with acute myocardial infarction (AMI). A total of 32 male patients with AMI were randomized into two groups: 15 patients with short-term low-intensity exercise training within 5 days formed the training group and 17 patients without such exercise training formed the control group. All patients performed exercise treadmill test with modified Bruce protocol before and after the study. F2-isoprostane and NO concentration of the training group increased slightly after modified Bruce exercise treadmill test. Compared with the control group, NO of the training group was also slightly higher. Baseline NO and uric acid were negative predictor variables for F2-isoprostane in all patients hospitalized with AMI, and triglyceride was a positive predictor variable. After the study, physical capacity of the training group was higher; but heart rate and systolic blood pressure were lower significantly. This study showed that short-term low-intensity exercise training for patients hospitalized with AMI did not change ROS and NO productions, but it improved physical capacity and lowered heart rate and systolic blood pressure. NO was negative predictor variable for F2-isoprostane in controlling ROS changes in dynamic compensation mechanism.

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“…Unfortunately, the clinically relevant biomarker for nitrate /nitrite exposure, high methemoglobin level in the blood, provides only imprecise evidence of exposure prior to and during the MHG episode as it is a temporary elevation that the body begins to excrete quickly (Hartman, 1982;Mbanugo et al, 1990;Stolwijk, 1995 ). Urinalysis also provides only minimal information concerning excretion amount and, possibly, rate (Ellis et al, 1998 ). Further, Romanian public health authorities do not Determine current methemoglobin levels to reflect on possible past levels and current exposures.…”

Section: Subjectsmentioning

confidence: 99%

Exposure methodology and findings for dietary nitrate exposures in children of Transylvania, Romania

Zeman

Vlad²,

Kross

2002

J Expo Sci Environ Epidemiol

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Aims: The primary focus of this exposure assessment work involved developing an exposure model and determining a numerical point estimate of the amount of biologically relevant nitrate / nitrite exposure that occurred for each child in the study. This assessment was done in support of two epidemiological studies. The first study was an epidemiological cohort study ( three cohorts based on nitrate / nitrite exposure ) that explored the relationship between high nitrate / nitrite exposure and neuropsychological development. The second study was a nested case / control study ( cases of methemoglobinemia versus disease -free controls ) that sought to explore the relationship between MHG and various risk factors for the disease. Methods: This work uses both dietary survey and environmental sampling and modeling in order to develop two point estimates of nitrate exposure in milligrams per kilogram per day of nitrite ( the biologically active form of the hemoglobin -oxidizing agent ) for the first 6 months of the child's life ( 2 -months -of -age and 6 -months -of -age point estimates ). Methodologies included proxy interviews of primary caregivers, review of existing medical and environmental sampling and analysis. Results: Exposure to nitrate -nitrogen ( with final calculations converted to the biologically active form of the toxin, nitrite ) was categorized as high, medium, and low as determined from the distribution of the data derived from final exposure calculations at both the 2 -months -of -age point estimate and at the 6 -months -of -age point estimate. These tertiles correspond to !1.5 mg / kg / day nitrite -nitrogen for high -exposure individuals, < 1.5 -!0.1 mg / kg / day for medium -exposure individuals, and < 0.1 mg / kg / day for low -exposure individuals. Analyses illustrate that over 90% of the nitrate exposure occurred through the consumption of liquids ( water ) at the 2 -months -of -age point estimate while at the 6 -months -of -age point estimate, a 10 -fold change in the amount of solid consumables occurred. Conclusions: Final exposure calculations were well differentiated into three tertiles based on a point estimate of average daily intake of nitrite in milligrams per kilogram body weight per day at roughly 2 and 6 months of age. These categories of exposure, based on the exposure model point estimate, correspond well with the exposure estimates as estimated only on the basis of cohort status and their corresponding nitrate / nitrite well water levels. Comparisons of these two sets of data illustrate that following the MHG incident, Cohort II shifted places with Cohort I to become the high -exposure cohort. Further, the predictive ability of the exposure assessment in regard to the outcome of MHG was estimated using a Likelihood Ratio and Pearson's Crosstab analysis. This was performed on the 2 -month -of -age point estimate. Likelihood Ratio and Pearson's chi -square were 39.40 and 33.74, respectively, with a probability of achieving these fits by chance alone of < 0.0001. This indicates clearl...

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Nitrite and Nitrate Analyses: A Clinical Biochemistry Perspective

Cited by 243 publications

References 376 publications

Construction of effective disposable biosensors for point of care testing of nitrite

Construction of effective disposable biosensors for point of care testing of nitrite

Effect of Short-Term Low-Intensity Exercise Training on Association of Oxygen Free Radicals and Nitric Oxide Production in Patients with Acute Myocardial Infarction

Exposure methodology and findings for dietary nitrate exposures in children of Transylvania, Romania

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