Enzymatic colorimetric method for the determination of inorganic phosphorus in serum and urine.

The performance of an enzymatic colorimetric method for the determination of inorganic phosphorus in serum and urine is described. Phosphate ions react with inosine in the presence of purine nucleoside phosphorylase to form hypoxanthine; this is oxidized by xanthine oxidase to uric acid with production of hydrogen peroxide. The latter is determined with the aid of the chromogen system peroxidase/4-aminophenazone/N-ethyl-N-(3-methylphenyl)-N'-acetyl- ethylenediamine, the coloured product being measured at 555 nm. This series of reactions is completed in 5 min at 37\ub0C. The test is linear up to 240 mg/l. Analytical recovery in serum averaged 101.2 \ub1 1.2% and in urine 101.9 \ub1 3.2%. Within-run and between-run precision studies in serum and urine samples gave CVs 64 4.54% (at 22.0 mg/l). Results obtained by this method agree (r = 65 0.983) with the molybdate UV and molybdenum blue methods. Interference by endogenous substances, including organic phosphate, was negligible

Commutability of calibration and control materials for serum lipase

Background: To effectively assess and correct for intermethod variability, calibration and control materials (CCMs) must show the same intermethod behavior as patient sera, i.e., they must be commutable. We describe the commutability of selected CCMs for lipase assays, the impact of noncommutability of CCMs in normalizing patient results, and characteristics of reagents that affect assay specificity and commutability. Methods: Lipase was measured in 98 patient sera and in 29 commercial CCMs, with 2 commercial methods using different substrates and with 4 experimental methods using 1,2-o-dilauryl-rac-glycero-3-glutaric acid-(6\u2032-methylresorufin) ester as substrate and colipase as cofactor, but differing in the stabilizing proteins used and in the size of the substrate micelles. Results: The noncommutability rate, i.e., the frequency of aberrant intermethod behavior of CCMs in comparison with patient sera, was 27% for liquid CCMs and 47% for lyophilized CCMs. The normalized residuals, measuring the degree of noncommutability, were -2.3 to 2.4 for CCMs with "normal" lipase activity, and -3.5 to 21.7 for CCMs with higher lipase activity. Recalculation of patient results with CCMs as calibrators decreased or increased the original bias according to whether the CCMs were commutable. Conclusions: For the lipase methods in this study, the frequency of noncommutability of CCMs is affected by assay-specific characteristics, including size of substrate micelles and the presence or absence of added proteins

N-terminal proB-type natriuretic peptide (NT-proBNP) concentrations in elite rugby players at rest and after active and passive recovery following strenuous training sessions

BACKGROUND: The serum biomarker N-terminal proB-type natriuretic peptide (NT-proBNP), a cleaved fragment of the brain natriuretic peptide (BNP) precursor (amino acids 1-76), is accepted as a standard marker for evaluating and monitoring cardiac injury characterized by myocardial wall stress. Strenuous exercise may generate transitory ischemia, myocardial stress and diastolic left ventricular dysfunction, possibly inducing increased concentrations of NT-proBNP. A purported caveat to prolonged strenuous exercise is based on evidence for biochemical and structural signs of heart dysfunction in recreational athletes after continuous exertion. METHODS: We compared NT-proBNP levels in three groups of physically fit subjects: top-level rugby players, professional soccer players and healthy controls. NT-proBNP concentrations were measured at rest and after an intensive training session followed by two different recovery strategies (passive or active). RESULTS: A comparison of the three samples showed that NT-proBNP concentrations in the rugby players were lower than those in controls at rest and were similar to those in professional soccer players. Elevated post-training NT-proBNP levels were unaffected by the type of recovery. The relatively high NT-proBNP levels after active recovery when psychophysical stress is higher, because of cycling and cold water immersion, suggest that not only endurance exercise, but also strenuous, stressful short exercise can induce an increase in NT-proBNP concentrations. CONCLUSIONS: In this sample of professional athletes, NT-proBNP was low at rest, and the increase after physical exercise was physiological

Oxidative stress and antioxidant status in patients with erectile dysfunction

Introduction. Erectile dysfunction (ED) is increasingly recognized as a public health problem. The interaction between nitric oxide and reactive oxygen species is one of the important mechanisms implicated in the pathophysiological process of ED. Plasma contains various antioxidant components to prevent free-radical injury. Aim. The aim of this study was to determine and compare the oxidative and antioxidant status of peripheral venous blood in patients with ED of arteriogenic and non-arteriogenic origin. Methods. Oxidative stress and antioxidant status were assessed in 40 patients with ED and 20 healthy controls. Main Outcome Measures. Plasma reactive oxygen metabolite (ROM) concentrations were measured as an indicator of oxidative stress, and plasma total antioxidant status (TAS) to indicate antioxidant defense. Results. Plasma ROM concentrations were higher (349.75 +/- 53.35 standard deviation [SD] U.Carr vs. 285.43 +/- 25.58 U.Carr, P < 0.001) and plasma TAS lower (0.54 +/- 0.16 SD mmol/L vs. 0.94 +/- 0.28 SD mmol/L, P < 0.0001) in patients with arteriogenic ED in comparison to those in patients with non-arteriogenic ED. Plasma ROM and TAS in controls were not significantly different from those in non-arteriogenic ED. Conclusions. This observation may be useful to better understand and distinguish arteriogenic from non-arteriogenic ED using laboratory tests. In addition, our findings provide important support for an antioxidant therapy to try to correct oxidative stress in arteriogenic ED patients. Barassi A, Colpi GM, Piediferro G, Dogliotti G, Melzi D'Eril GV, and Corsi MM. Oxidative stress and antioxidant status in patients with erectile dysfunction

Genetic control of chemokines in severe human internal carotid artery stenosis

Background and purpose: Atherosclerosis is an inflammatory disease. Chemokines and chemokine receptors are known to be involved in atherogenesis. Common single nucleotide polymorphisms (SNPs) affect transcription in response to inflammatory stimuli. The aim of this study was to evaluate the correlations between MCP-1, RANTES, SDF-1, CCR2, and CCR5 gene polymorphisms with increased risk of internal carotid artery (ICA) stenosis. Methods: Hundred and twelve patients, consecutively recruited for ICA occlusive disease, and 282 controls were genotyped for MCP-1-2518G, RANTES-403A, CCR5D32, CCR2 V64I, and SDF-1-801A polymorphisms. Results: The frequency of the SDF-1A allele was significantly different between cases and controls: 0.32 vs. 0.20, respectively (OR 1.81; 95% CI 1.25\u20132.60; p = 0.007). The frequency of the RANTES-403G allele was significantly higher in patients with stenosis >70% (OR, 2.45; 95% CI 1.12\u20135.71; p = 0.015). No significant differences were observed with the other polymorphisms. Conclusion: The reported results seem to correlate the polymorphisms of the genes encoding for SDF-1, RANTES with pathogenesis and progression of ICA occlusive disease. Although suggestive, these results need confirmation in prospective cross-sectional studies

The role of inflammation in patients with intraductal mucinous neoplasm of the pancreas and in those with pancreatic adenocarcinoma

Background: There are very few data regarding inflammation in patients with intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. Aim: To evaluate the circulating concentrations of placental growth factor (PlGF), transforming growth factor-alpha (TGF-\u3b1), transforming growth factor-beta 1 (TGF-\u3b21), tumour necrosis factor receptor 1 (TNF-R1) and matrix metalloproteinase-2 (MMP-2) in patients with IPMNs and in those with pancreatic adenocarcinomas. Patients and Methods: Sixty-nine patients were enrolled: 23 (33.3%) had IPMNs and 46 (66.7%) had histologically confirmed pancreatic adenocarcinomas. Thirteen healthy subjects were also studied. PlGF, TGF-\u3b1, TGF-\u3b21, TNF-R1 and MMP-2 were determined using commercially available kits. Results: TNF-R1 (p=0.003) was the only protein significantly different among the three groups. Conclusion: Serum TNF-R1 was elevated in patients with IPMNs and in those with pancreatic adenocarcinomas, suggesting a high apoptotic activity in both groups of patients studied

Changes in lipid profile in response to three different protocols of whole-body cryostimulation treatments

Systemic cryostimulation is useful treatment, both in sport and medicine, during which human body is exposed to very low, cryogenic temperature (below -100 \ub0C). Although there exists some evidence of its beneficial effect in biological regeneration, so far it has not been unequivocally determined if the positive effect of repeated stimulations depends on their number in a series. The aim of this research was to estimate the influence of 5, 10 and 20 sessions of 3. min-long exposures to cryogenic temperature (-130 \ub0C) on the lipid profile in physically active men. Sixty-nine healthy volunteers participated in the study. The blood samples were taken in the morning, after overnight fasting, before the first cryostimulation session, and the following morning after the last one (5th,10th, 20th). In serum specimens the concentration of total cholesterol (TCh), HDL cholesterol and triglicerydes were determined using enzymatic methods. LDL cholesterol level was calculated using Friedewald formula. The changes in lipid profile (LDL decrease with simultaneously HDL increase) occurred after at least 10 sessions of cryostimulation