Sexually transmitted doping: The impact of urine contamination of semen.

The high sensitivity of antidoping detection tests creates the possibility of inadvertent doping due to an athlete's unknowing ingestion of contaminated environmental sources such as dietary supplements, food, or drinks. Recently, athletes denying use of a prohibited substance have claimed that the positive antidoping tests was due to exchange of bodily fluids with a nonathlete partner using a prohibited substance. Measurement of drugs in semen is largely limited to one or very few samples due to the inaccessibility of sufficiently frequent semen samples for detailed pharmacokinetics. An emerging issue in semen drug measurements is that semen samples may contain residual urine from ejaculation left in the urethra; however, the urine content in semen samples has not been studied. In the present study, we employed concurrent creatinine measurements in urine and seminal plasma to determine the urine content of semen samples.

Serum uric acid is associated with bone health in older men: a cross-sectional population-based study.

Serum uric acid (UA) is a strong endogenous antioxidant. Since oxidative stress has been linked to osteoporosis, we examined the association between serum UA levels and bone mineral density (BMD), prevalent vertebral and nonvertebral fractures, and laboratory measures such as calcitropic hormones and bone turnover marker levels. This cross-sectional analysis consisted of 1705 community-dwelling men aged 70 years or over who participated in the baseline part of the Concord Health and Ageing in Men Project (CHAMP), a population-based study of older men in Sydney, Australia. BMD at all sites was significantly higher among men with serum UA levels above the group median than among men with UA levels below the median. In multiple regression analyses adjusted for potential confounders, serum UA remained associated with BMD at all sites (ß = 0.12 to 0.14, p < .001), serum calcium (ß = 0.11, p = .001), parathyroid hormone (ß = 0.09, p = .002), 25-hydroxyvitamin D (ß = 0.09, p = .005), and was negatively associated with urinary excretion amino-terminal cross-linked telopeptide of type 1 collagen (ß = -0.09, p = .006). Overall, serum UA accounted for 1.0% to 1.44% of the variances in BMD (R(2) = 0.10 to 0.22). In multiple logistic regression analyses, above-median serum UA levels were associated with a lower prevalence of osteoporosis at the femoral neck [odds ratio (OR) = 0.42, 95% confidence interval (CI) 0.22-0.81, p = .010) and lumbar spine (OR = 0.44, 95% CI 0.23-0.86, p = .016) and a lower prevalence of vertebral (OR = 0.62, 95% CI 0.43-0.91, p = .015) and nonvertebral (OR = 0.51, 95% CI 0.29-0.89, p = .018) fractures. In conclusion, higher serum UA levels are associated with higher BMD at all skeletal sites and with a lower prevalence of vertebral and nonvertebral fractures in older men.

A new quantitative LC tandem mass spectrometry assay for serum 25-hydroxy vitamin D.

BACKGROUND: The accurate measurement of 25-hydoxy vitamin D (25OH-D) in serum has been a challenge for many years. We developed a liquid chromatography tandem mass spectrometry (LC Tandem MS) assay for the quantitative determination of 25OH-D(2) and 25OH-D(3) in serum. The new method was compared with two widely used commercially available immunoassays. METHODS: Sample preparation involved protein precipitation with acetonitrile containing deuterated forms of the target species as internal standards. An API 5000 mass spectrometer coupled with a photoionization source was used for quantitation. The performance of the new LC Tandem MS assay was compared with a radioimmunoassay (RIA, Diasorin) and a chemiluminescence immunoassay (ECLIA, Roche Diagnostics), analysing serum obtained from 152 individuals. RESULTS: Using 100 µl of serum, the LC Tandem MS assay had a limit of quantitation of 1.3 nmol/L for both 25OH-D(2) and 25OH-D(3) with a linear response between 1.3 and 625 nmol/L and accuracy of between 95 and 124%. Intra- and inter-assay precision were ≤7% and ≤4%, respectively. Measurement of 25OH-D levels in 152 serum samples gave run averages of 71, 56 and 62 nmol/L for LC Tandem MS, ECLIA and RIA, respectively. Correlations between the various methods were: LC Tandem MS vs. RIA: r=0.931; LC Tandem MS vs. ECLIA: r=0.784; RIA vs. ECLIA: r=0.787. The LC Tandem MS method had a positive proportional bias of 26% over the RIA, whereas the ECLIA showed variable differences. CONCLUSION: The new LC Tandem MS assay is accurate and precise at physiologically relevant 25OH-D concentrations, and compares favourably with the RIA. In contrast, the ECLIA shows variable bias with the other assays tested.

Blood withdrawn through a cannula valve connector does not result in clinically significant haemolysis.

OBJECTIVE: To assess the impact of cannula valve connectors on haemolysis of blood samples drawn from newly inserted cannulae. METHODS: In a semi-blinded, randomized study paired blood samples, with and without cannula valve connector, were obtained from patients within the ED and tested for haemolysis, defined as haemolysis index of greater than 120 mg/dL. Patients were randomized as to which sample was collected first. Cannula size was standardized and vacutainer systems provided consistent draw pressures. Time taken for the tube to fill was recorded as a measure of blood flow. RESULTS: Two hundred and ninety patients were randomized, with six subsequently excluded from analysis because of samples being lost or insufficient for testing. Average patient age was 60.8 years and 52.5% were male. There were no significant differences between the randomization groups. The overall rate of haemolysis was 2.6%, being 2.8% in the valve first group and 2.5% in the no valve first group (P = 1.0). Time for collection averaged 7.7 s in the valve first group and 7.5 s in the no-valve first group (P = 0.22). Mean serum potassium level was 4.4 mmol/L in both groups (P = 0.46). The rate of hyperkalaemia was not different between valve first and no-valve first groups (12.7% and 13.7%, respectively, P = 1.0). CONCLUSION: The attachment of a cannula connector valve to a peripheral cannula prior to blood sampling is not associated with an increase in the rate of haemolysis or hyperkalaemia.

Early renal failure detection by cystatin C in Type 2 diabetes mellitus: varying patterns of renal analyte expression.

AIM: The early stages of renal failure are poorly diagnosed by current routine tests. We studied cystatin C and routine renal analyte patterns in Type 2 diabetes mellitus. METHODS: Type 2 diabetes mellitus patients (n = 48) were tested for serum cystatin C, urine albumin, haemoglobin A1c, serum creatinine, serum urea, urine creatinine, glucose, triglycerides and low density lipoproteins (LDL). Glomerular filtration rate (GFR) estimates were made using Cockroft-Gault and Modification of Diet in Renal Disease formulae. RESULTS: The cystatin C (95%CI) reference range was 0.78-0.86 mg/L. While serum cystatin C showed general correlation with routine renal tests, a plateau was observed in analytes measured against cystatin C. Cystatin C improved sensitivity led to detection of renal abnormality in 19% of patients not diagnosed by routine tests. CONCLUSIONS: Cystatin C is a more sensitive marker of renal disease in Type 2 diabetes mellitus where estimated GFR is unreported at >60 mL/min and where antihypertensive medications render microalbuminuria detection unreliable. Its incorporation into a panel of renal function tests is highly recommended.

Influence of history of heart failure on diagnostic performance and utility of B-type natriuretic peptide testing for acute dyspnea in the emergency department.

BACKGROUND: The aim of this study was to assess the impact of a history of heart failure (HF) on emergency department (ED) B-type natriuretic peptide (BNP) testing and impact of feedback of BNP level to ED physicians. METHODS: Admission BNP was measured in 143 patients (mean age 79 +/- 10 years) presenting to the ED with dyspnea. Emergency department physicians scored probability of HF as cause of dyspnea and categorized cause of dyspnea. An independent cardiologist determined cause of dyspnea after chart review. In 83 patients, ED physicians rescored and reclassified patients after BNP measurement and evaluated test utility. RESULTS: The area under the receiver operating characteristic curve for BNP diagnosis of HF cause of dyspnea was significantly worse in patients with history of HF than those without (0.74 vs 0.94, P < .01) and in those with left ventricular ejection fraction <50% (0.64 vs 0.87, P < .05). A BNP cut point of 100 pg/mL had 100% sensitivity but only 41% specificity for diagnosing acute HF, whereas a cut point of 400 pg/mL had 87% sensitivity and 76% specificity. Emergency department physicians rated BNP useful in 64% of patients, and diagnostic uncertainty was reduced from 53% to 25% (P < .001). CONCLUSION: B-type natriuretic peptide test performance for diagnosis of dyspnea cause is significantly reduced in patients with a history of HF and must be taken into consideration in the evaluation of such patients in the ED.

Laboratory results in the elderly: the Sydney Older Persons Study.

BACKGROUND: The use of laboratory intervals based on younger and healthier populations is of questionable validity in older populations. The aim of this study was to examine haematological and biochemical profiles in a sample of community-dwelling older people and to study the impact of age, disease, disability and medications. METHODS: Basic haematological and biochemical values were obtained for 338 survivors of a random sample of community-living people aged 75 years or over at time of recruitment. These values were compared to the laboratory reference intervals and the effects of age, disease, medication and disability examined. RESULTS: The distribution of the 35 parameters measured differed from those described by the laboratory reference intervals in all but four of the variables. The values showed few significant age associations but did show associations with disease, disability and drug use. CONCLUSIONS: Abnormalities identified in haematological and biochemical testing are not due to age but to age-related illnesses. This is contrary to previous studies reporting a change in haematological and biochemical parameters purely on the basis of age. In the presence of abnormalities, identification and clarification of disease states should be made.