Urine drug-testing tampering approaches: Turkish probationers.

The growing numbers of individual and social problems associated with drug abuse necessitate new approaches in drug-testing systems. Equally, drug abusers may attempt to invalidate drug testing using different methods such as adulteration, dilution and substitution. This study aims to investigate tampering methods commonly used by Turkish substance-using probationers and evaluate their effects on toxicological drug-testing results. Initially, probationer urinary screening test results and laboratory substitution documents were evaluated to investigate the dilution and substitution attempt. Additionally, an experimental study was carried out by using readily available household products (bleach, vinegar, drain opener, eye drops) for adulteration. The effect of these agents was investigated for 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH), amphetamine and 3,4-methylenedioxymethamphetamine (MDMA). It was determined that probationers preferred unbranded products (syringes, nylon bottles, etc.) for urine substitution. To detect dilution, screening test results were evaluated along with creatinine values. The variability of mean creatinine values can change the rate of the before-negative and after-positive ratio. For adulteration method, the high amounts of bleach provided false-negative results for THC-COOH and amphetamine, but spiking in any concentration of bleach affected MDMA results, causing a slight increase. Vinegar did not affect the THC-COOH and amphetamine results. However, false-negative results were observed for MDMA, with high amounts of vinegar-spiked urine samples. Drain opener was added in large quantities, and false-negative results were observed for all analytes. Visine eye drops did not have any effect on THC-COOH or amphetamine, but a high quantity of eye drops had a slight decreasing effect for MDMA.

Analysis of renal stones by capillary isotachophoresis.

An analytical method for the determination of the composition of renal stones by capillary isotachophoresis with conductometric detection was developed. Using different leading/terminating electrolyte systems, the qualitative and quantitative analysis of organic compounds (urate, xanthate, oxalate) and inorganic ions (phosphate, Ca(2+), Mg(2+), Na(+), NH(4)(+)) species commonly present in mixed renal stones in three separate steps can be carried out with limits of detection about 10 µmol/L. The developed method was validated by the analysis of real samples and can be used for urinary calculi classification. In addition, it was verified that this method can also be employed for the determination of the above mentioned analytes in some other samples (bones, teeth) concerning apatite biominerals (fluoro-, carbonate-, chloro-apatite).

Quantification of carbonate by gas chromatography-mass spectrometry.

Carbon dioxide and carbonates are widely distributed in nature, are constituents of inorganic and organic matter, and are essential in vegetable and animal organisms. CO(2) is the principal greenhouse gas in the atmosphere. In human blood, CO(2)/HCO(3)(-) is an important buffering system. Quantification of bicarbonate and carbonate in inorganic and organic matter and in biological fluids such as blood or blood plasma by means of the GC-MS technology has been impossible so far, presumably because of the lack of suitable derivatization reactions to produce volatile and thermally stable derivatives. Here, a novel derivatization reaction is described for carbonate that allows for its quantification in aqueous alkaline solutions and alkalinized plasma and urine. Carbonate in acetonic solutions of these matrices (1:4 v/v) and added (13)C-labeled carbonate for use as the internal standard were heated in the presence of the derivatization agent pentafluorobenzyl (PFB) bromide for 60 min and 50 °C. Investigations with (12)CO(3)(2-), (13)CO(3)(2-), (CH(3))(2)CO, and (CD(3))(2)CO in alkaline solutions and GC-MS and GC-MS/MS analyses under negative-ion chemical ionization (NICI) or electron ionization (EI) conditions of toluene extracts of the reactants revealed formation of two minor [i.e., PFB-OCOOH and O=CO(2)-(PFB)(2)] and two major [i.e., CH(3)COCH(2)-C(OH)(OPFB)(2) and CH(3)COCH=C(OPFB)(2)] carbonate derivatives. The latter have different retention times (7.9 and 7.5 min, respectively) but virtually identical EI and NICI mass spectra. It is assumed that CH(3)COCH(2)-C(OH)(OPFB)(2) is formed from the reaction of the carbonate dianion with two molecules of PFB bromide to form the diPFB ester of carbonic acid, which further reacts with one molecule of acetone. Subsequent loss of water finally generates the major derivative CH(3)COCH=C(OPFB)(2). This derivatization reaction was utilized to quantify total CO(2)/HCO(3)(-)/CO(3)(2-) (tCO(2)) in human plasma and urine by GC-MS in the NICI mode by selected ion monitoring of the anions [M-H](-) of CH(3)COCH=C(OPFB)(2) at m/z 461 for the endogenous species and m/z 462 for the internal standard (13)CO(3)(2-). Oral intake of the carboanhydrase inhibitor drug acetazolamide by two healthy volunteers resulted in temporary increased excretion of tCO(2) in the urine. The method is specific for carbonate, accurate, sensitive and should be applicable to various matrices including human fluids and environmental samples.

Food mineral composition and acid-base balance in rabbits.

BACKGROUND: Alkali-rich diets are often recommended in human medicine to prevent the pathological consequences of nutritional acid load in conditions of impaired renal function. AIM OF THE STUDY: This study was undertaken in rabbits as common laboratory animals for basic medical research to explore the impact of high versus low dietary alkali intake on systemic acid-base balance and renal control in a typical herbivore. METHODS: Male rabbits (2.3-4.8 kg) were kept in a metabolism cage. The 24h urine and arterial blood samples were analysed for acid-base data. The metabolic CO2 production was measured to calculate alveolar ventilation. Three randomized groups of animals were fed ad libitum with rabbit chow providing sufficient energy but variable alkali load, assessed by the ashes' cation-anion difference. RESULTS: The average daily nutritional alkali load (+/- SEM) was 67.1 +/- 2.2 mEq x kg(-1) (N = 58) in the group on high, 45.4 +/- 2.5 mEq x kg(-1) (N = 31) in the group on normal and 1.7 +/- 0.5 mEq x kg(-1) (N = 11) in the group on low alkali food. Respective mean arterial base excess values (BE) were 1.4 +/- 0.3 mM, 0.3 +/- 0.4 mM and 0.0 +/- 0.3 mM, being significantly higher on high alkali food (P < 0.05) than in the other groups. Arterial PCO2, alveolar ventilation and metabolic CO2 production were not significantly different between groups. On normal and high-alkali chow, an alkaline urine (pH(u) > 8.0) with 18-20 mmol x kg(-1) bicarbonate/carbonate was excreted daily, typically containing an insoluble precipitate of 35-60% carbonate. On low-alkali diet, the mean pH(u) decreased to 6.26 +/- 0.14, due to a strong reduction of daily excreted soluble bicarbonate and precipitated carbonate to 1.2 +/- 0.6 and 0.7 +/- 0.2 mmol x kg(-1), respectively. Thereby, nearly complete fractional base reabsorption of 97.8 +/- 0.7 % was reached. CONCLUSION: Herbivore nutritional alkali-load elicited large rates of renal base excretion including precipitates, to which the urinary tract of the rabbits appeared to be adapted. Dietary base variations were more accurately reflected in the urine than by the blood acid-base status. A strongly base-deficient diet exerted maximum impact on renal base saving mechanisms, implying a critical precondition for growing susceptibility to metabolic acidosis also in the rabbit.

Fiberoptic infrared spectroscopy: a novel tool for the analysis of urine and urinary salts in situ and in real time.

OBJECTIVES: To use infrared fiberoptic spectroscopy for the analysis of urinary salts in real time and with no sample processing; and to assess the practical role of this method for the quantitative measurement of the composition of urine and for the diagnosis of urolithiasis in patients. METHODS: Urine samples were obtained from two groups of patients: 24 patients with stone formation after shock wave lithotripsy and 24 normal subjects of similar age. Infrared absorption measurements were performed in real time, using infrared transmitting silver halide fibers. The absorption data were compared with the infrared absorption spectra of aqueous solutions prepared in our laboratory, with known concentrations of known urinary salts. The results were used for the study of the chemical composition of these salts in the urine samples and for a quantitative analysis of the concentration of the salts. RESULTS: We determined the composition of the stones in 20 of the 24 patients on the basis of the characteristic absorption peaks for the oxalates, carbonates, urates, and phosphates observed in their urinary samples. Using the method mentioned above, we found the concentration of different salts in urine with an average error of 20%. CONCLUSIONS: Fiberoptic infrared spectroscopy could be used as a new diagnostic tool for detecting different urinary salts in urine, finding their chemical composition, and determining their concentrations, without any sample preparation.

Analysis of anion constituents of urine by inorganic capillary electrophoresis.

Inorganic capillary electrophoresis (ICE) is a new separations technology which melds the technique of classical electrophoresis with the separations approach of ion chromatography. Matrices which have been difficult to deal with using ion chromatography have proven amenable to analysis by ICE. The simultaneous analysis of weak acid anions, oxalate and citrate and inorganic anions, chloride, sulfate, nitrate, phosphate and carbonate in diluted urine was achieved using ICE. The determination of the oxyanions of arsenic (i.e. arsenite and arsenate) in urine was also performed.

Renal net acid and electrolyte excretion in an experimental model of hypochloremic metabolic alkalosis in sheep.

Renal electrolyte and net acid excretion were characterized during generation and maintenance of hypochloremic metabolic alkalosis in a ruminant model. Two phases of renal response with regard to sodium and net acid excretion were documented. An initial decrease in net acid excretion was attributable to increase in bicarbonate excretion with associated increase in sodium excretion. As the metabolic disturbance became more advanced, a second phase of renal excretion was observed in which sodium and bicarbonate excretion were markedly decreased, leading to increase in net acid excretion and development of aciduria. Throughout the metabolic disturbance, chloride excretion was markedly decreased; potassium excretion also decreased. These changes were accompanied by increase in plasma renin and aldosterone concentrations. There was apparent failure to concentrate the urine optimally during the course of the metabolic disturbance, despite increasing plasma concentration of antidiuretic hormone.

Effect of dietary anion composition on acid-induced hypercalciuria in the adult rat.

The effects of replacing dietary carbonate (0.3 meq/g diet) by sulfate (SO4) or chloride (Cl) on urinary calcium (Ca) excretion were investigated in the adult male rat. When anion substitutions were made by manipulating Ca and Mg salts, urinary Ca excretion was significantly higher in the SO4 and Cl groups, the Cl-induced calciuria being twice that of the SO4 group. Replacement of carbonate by chloride was associated with higher net acid excretion. Replacement by SO4 promoted an equivalent excretion of acid, if apparent absorption of anion is taken into account. When substitutions were made by manipulating magnesium, sodium and potassium but not Ca salts, urinary Ca excretion and net acid excretion were higher in both fixed anion groups. In this second study, absorption of anion in the Cl and SO4 groups was not different (54 and 59%, respectively). Feeding either Cl or SO4 raises urinary Ca to a similar extent when equivalent changes in acid-base balance are induced. The excessive calciuria, ascribed by others to the formation of CaSO4 complexes in the urine, is not manifest when net acid excretion is significantly increased.

Applicability of biosuppressin as an urease-inhibitor.

Prevention of the formation of struvite and carbonate-apatite calculi, which rapidly increase in size and tend to recur, is of prime importance. One of the urease inhibitors, hydroxycarbamide, was studied in vitro. The results are favourable and justify further studies aimed at the local application of the inhibitor.

Preservation of urinary postprandial alkaline tide despite inhibition of gastric acid secretion.

Ingestion of food leads to a rise in urinary pH. This phenomenon is commonly known as "postprandial alkaline tide" and is generally attributed to acid secretion in the stomach. To examine this hypothesis, we studied the changes of urinary pH, H+ concentration, PCO2, and bicarbonate in nine healthy volunteers with and without histamine H2 receptor blockade, using cimetidine and placebo medication. Postprandial alkaline tide persisted and was even exaggerated during treatment with cimetidine. Preservation of postprandial urinary alkaline tide, despite the expected inhibition of gastric acid secretion by cimetidine, tends to exclude a causal relation between alkaline tide and gastric acid secretion.

[Prevention of urinary calculi with covalitin and by general measures]. / Prophylaxie médicamenteuse avec Covalitin et générale de l'urolithiase.

The prophylaxis of the urinary lithiasis by means of drugs (alkalinisants, Eisemberg's syrup, allopurinol, etc.) obtains a very good result against uric acid and urate stones. The prevention of stones of oxalates, phosphates, carbonates, etc. is possible by trichlormethiazide (if hypercalciuria is present) and especially by a new drug, the Covalitin. Naturally diet and hydrotherapy. Decalogue for the stone's prophylaxis is done.

[Age related effects of furosemide in the rat]. / Altersabhängige Wirkungen von Furosemid bei Ratten

Furosemide (6 mg/kg i.p.) increases the renal excretion of water, osmotic active substances, sodium and chloride in 5 to 33 day old rats more than in adults. The dose-response-relations are the same in rats of all age groups: 6 mg/kg of furosemide i.p. are very effective, an increase in dose to 30-60 mg/kg i.p. is not followed by a significantly higher efficacy. The increase in the renal excretion of potassium, hydrogen ions, ammonium and hydrogen carbonate by furosemide is also small in young rats.