A comparison of the excretion rate of endogenous purine derivatives in the urine of Bos indicus and Bos taurus steers

Estimates of microbial crude protein (MCP) production by ruminants, using a method based on the excretion of purine derivatives in urine, require an estimate of the excretion of endogenous purine derivatives (PD) by the animal. Current methods allocate a single value to all cattle. An experiment was carried out to compare the endogenous PD excretion in Bos taurus and high-content B. indicus ( hereafter, B. indicus) cattle. Five Holstein - Friesian ( B. taurus) and 5 Brahman (> 75% B. indicus) steers ( mean liveweight 326 +/- 3.0 kg) were used in a fasting study. Steers were fed a low-quality buffel grass (Cenchrus ciliaris; 59.4 g crude protein/kg dry matter) hay at estimated maintenance requirements for 19 days, after which hay intake was incrementally reduced for 2 days and the steers were fasted for 7 days. The excretion of PD in urine was measured daily for the last 6 days of the fasting period and the mean represented the daily endogenous PD excretion. Excretion of endogenous PD in the urine of B. indicus steers was less than half that of the B. taurus steers ( 190 mu mol/kg W-0.75. day v. 414 mu mol/kg W-0.75. day; combined s.e. 37.2 mu mol/kg W-0.75. day; P< 0.001). It was concluded that the use of a single value for endogenous PD excretion is inappropriate for use in MCP estimations and that subspecies-specific values would improve precision.

Speciation of arsenic metabolites in the urine of occupational workers and experimental rats using an optimised hydride cold-trapping method

A hydride cold-trapping technique was developed and optimised for the measurement of urinary arsenic metabolites. The analytical precision of the method was found to be 6.1, 4.0 and 4.8% (n = 5) for inorganic arsenic (As-i), monomethylarsonate (MMA) and dimethylarsinate (DMA), respectively, with recoveries close to 100%, The detection limits were 1.0, 1.3 and 3 ng for As-i, MMA and DMA, respectively. The method was then used to analyse urine samples obtained from three groups of workers for occupational exposure in three companies where copper chrome arsenate was used for timber treatment. The results were compared with those for a normal control group of laboratory workers. Arsenic and its metabolites were also measured in experimental rats given 5 mg As kg(-1) body mass by oral gavage in the form of sodium arsenite, calcium arsenite or sodium arsenate. Occupational workers showed a significantly higher excretion of As-i, Up to two fold increases of urinary As-i excretion in rats compared with control rats were also observed in animals dosed with various forms of arsenicals. The method is suitable for the measurement of arsenic metabolites in urine of both humans and experimental animals.

Measurement of total phospholipids in urine of patients treated with gentamicin

Aims The excretion of phospholipids in urine may be a marker of the early renal toxicity of the aminoglycoside antibiotics. Urinary phospholipids are formed in myeloid bodies which develop in the lysosomes of proximal tubules during treatment with the aminoglycosides, and overflow into the urine. Methods Published assays were modified in order to measure the total phospholipid concentrations in human urine. Phospholipids were extracted from freeze-dried urine samples, digested in concentrated sulphuric acid, and the inorganic phosphorus content determined by complexing with ammonium molybdate and measuring the absorbance at 820 nm. Ten septicaemic patients treated with gentamicin for 5-7 days had significantly higher urine phospholipid concentrations than 10 healthy untreated control subjects (P<0.0001). There was a negative Linear relationship between phospholipid excretion and creatinine clearance (r(2) = 0.71). Results In 34 patients with acute pyelonephritis, increased phospholipid concentrations were observed prior to treatment compared with healthy controls (P<0.001) and did not alter during treatment with gentamicin. However, the phospholipid concentrations decreased significantly after treatment was completed (P<0.03). Conclusions These studies suggest that urinary phospholipids may indicate early aminoglycoside toxicity but with poor specificity, as many of the infections being treated may themselves be associated with phospholipiduria.

Cadmium levels in the lung, liver, kidney cortex, and urine samples from Australians without occupational exposure to metals

The authors undertook this study to assess levels of cadmium exposure in the general population. Samples of lung, liver, and kidney were obtained from 61 cadavers (43 males, 18 females; 2-89 yr of age, mean age = 38.5 yr) who died from accidental causes and who were subject to postmortem examinations at the John Tonge Centre for Forensic Sciences, Queensland Health Scientific Services, Brisbane, Australia, in 1997 and 1998. Samples of bladder urine were also obtained from 22 cadavers. Tissue and urine samples were analyzed for cadmium, zinc, and copper with inductively coupled plasm (ICP) mass spectrometry. The overall mean values for cadmium in the lung, liver, and kidney cortex samples were 0.13, 0.95, and 15.45 mug/gm wet tissue weight. The average renal cadmium level in subjects with high lung-cadmium levels (n = 13) was 6 mug/gm wet tissue weight higher than that of similarly aged subjects who had medium lung-cadmium levels (n = 30). In females, the average level of cadmium in the liver was 74% greater than in males, and the average liver cadmium in females with high lung-cadmium levels was 100% higher than in males in the same age range who had the same high lung-cadmium levels. Renal cadmium accumulation tended to be greater in females than in males who were in the same age range and who had similar lung-cadmium levels, a result that suggested that there was a higher absorption rate of cadmium in females. The mean value for a urinary cadmium excretion of 2.30 mug/gm creatinine was found in a subset of samples that had a mean age of 39 yr and a renal cortex cadmium concentration of 18.6 mug/gm wet tissue weight. Urinary cadmium excretion rates were correlated more strongly with lung and kidney cadmium content than with age or liver cadmium levels. The results suggest that urinary cadmium excretion may be increased in smokers and could provide some estimate of body cadmium burdens in future Australian epidemiological studies.

Porphyrin profiles in blood and urine as a biomarker for exposure to various arsenic species

A sensitive method using HPLC with fluorescence detection has been established for the measurement of porphyrins in biological materials. The assay recoveries were 88.0 +/- 1.8% for protoporphyrin IX in the blood, and ranged from 98.3 +/- 2.7% to 111.1 +/- 7.4% for various porphyrins in the urine. This method was employed to investigate the altered porphyrin profiles in rats after a single dose of various arsenicals including soluble sodium arsenate and sodium arsenite, and the relatively insoluble calcium arsenite, calcium arsenate and arsenic-contaminated soils at dose rates of 5 mg/kg or 0.5 mg/kg body weight. Porphyrin concentrations increased within 24-48hr after the arsenic treatment in blood and urine. Protoporphyrin IX is the predominant porphyrin in the blood. In rats administered 5 mg As(III)/kg body weight, protoporphyrin IX concentration elevated to 123% of them control values in rats, 24 hr after the treatment. Higher increases were recorded in the urinary protoporphyrin IX (253% at 24 hr; 397% on day 2), uroporphyrin (121% at 24 hr; 208% on day 2) and coproporphyrin 111 (391% at 24 hr; 304% on day 2), while there was no significant increase (109% on day 3) observed in the urinary coproporphyrin I excretion. In rats administered 5 mg As(V)/kg, urinary excretion of protoporphyrin IX, uroporphyrin, coproporphyrin Ill and coproporphyrin I elevated to the maximum levels by 48 hr with the corresponding percentage values compared to the control being 177%, 158%, 224% and 143%, respectively. In rats dosed with 5 mg As(III)/kg, the increases (expressed as % of the control values) of protoporphyrin IX in the blood were in the order: sodium arsenite (144%) > sodium arsenate (125%) greater than or equal to calcium arsenite (123%) > calcium arsenate. In contrast, there was no significant increase of protoporphyrin K when the six arsenic-contaminated cattlei dip soils and nine copper chrome arsenate (CCA-contaminated) soils were administered to the rats. Probable explanations are discussed.

Effect of nutrition level and diets on creatinine excretion by sheep

In this experiment, creatinine (C) excretion by sheep was measured when they were fed different diets at different levels of intake. Creatinine excretion was not affected by the level of feed intake or the addition of salt to lucerne-based diets. However, differences between individual animals were significant. Creatinine excretion was significantly affected by diets, which were formulated by combining different amounts of lucerne chaff, oaten chaff and sorghum. It was also found that there were significant diurnal changes in the ratios of purine derivatives to creatinine (PD:C) in 3 hourly urine samples when the animals were fed either once or twice daily, but the average value for the PD:C ratio of any two urine samples taken 12 h apart was close to the daily mean. The results of this experiment suggest that if separate determination of the creatinine excretion by individual animals is made and the average value of the ratio of PD:C in two spot urine samples taken 12 h apart is used to predict PD excretion by spot urine sampling, microbial nitrogen flow can be estimated more accurately than when a fixed value of creatinine excretion is used for all animals and only a single urine sample is taken. (c) 2005 Elsevier B.V. All rights reserved.

Urinary excretion of cadmium among Torres Strait Islanders (Australia) at risk of elevated dietary exposure through traditional foods

This study explored urinary cadmium levels among Torres Strait Islanders in response to concerns about potential health impact of high levels of cadmium in some traditional seafood (dugong and turtle liver and kidney). Cadmium levels were measured by inductively coupled mass spectrometry in de-identified urine samples collected during general screening programs in 1996 in two communities with varying dugong and turtle catch statistics. Statistical analysis was performed to identify links between cadmium levels and demographic and background health information. Geometric mean cadmium level among the sample group was 0.83 mu g/g creatinine with 12% containing over 2 mu g/g creatinine. Cadmium level was most strongly associated with age (46% of variation), followed by sex (females > males, 7%) and current smoking status (smokers > non-smokers, 4.7%). Adjusting model conditions suggested further positive associations between cadmium level and diabetes (p = 0.05) and residence in the predicted higher exposure community (p = 0.07). Positive correlations between cadmium and body fat in bivariate analysis were eliminated by control for age and sex. This study found only suggestive differences in cadmium levels between two communities with predicted variation in exposure from traditional foods. However, the data indicate that factors linked with higher cadmium accumulation overlap with those of renal disease risk (i.e. older, females, smokers, diabetes) and suggest that levels may be sufficient to contribute to renal pathology. More direct assessment of exposure and health risks of cadmium to Torres Strait Islanders is needed given the disproportionate level of diet-related disease and the cultural importance of dugong and turtle. This study highlights the need to consider social and cultural variation in exposure and to de. ne "safe'' cadmium levels during diabetes given its rising global prevalence.

Determination of pindolol enantiomers in human plasma and urine by simple liquid-liquid extraction and high-performance liquid chromatography

A simple method for the measurement of pindolol enantiomers by HPLC is presented. Alkalinized serum or urine is extracted with ethyl acetate and the residue remaining after evaporation of the organic layer is then derivatised with (S)-(-)-alpha-methylbenzyl isocyanate. The diastereoisomers of derivatised pindolol and metoprolol (internal standard) are separated by high-performance liquid chromatography (HPLC) using a C-18 silica column and detected using fluorescence (excitation lambda: 215 nm, emission lambda: 320 nm). The assay displays reproducible linearity for pindolol enantiomers with a correlation coefficient of r(2) greater than or equal to 0.998 over the concentration range 8-100 ng ml(-1) for plasma and 0.1-2.5 mu g ml(-1) for urine. The coefficient of variation for accuracy and precision of the quality control samples for both plasma and urine are consistently

Leaking urine in Australian women: Prevalence and associated conditions

The paper aims to (1) assess the prevalence of leaking urine and to (2) explore associations between leaking urine and a variety of other symptoms, conditions, surgical procedures and life events in three large cohorts of Australian women, who are participants in the Australian Longitudinal Study on Women's Health. Young women aged 18-23 (N = 14,000), mid-age women, 45-50 (N 13,738) and older women, 70-75 (N = 12,417), were recruited randomly from the national HIC/Medicare database. Leaking urine was reported by approximately one in eight young women [estimated prevalence 12.8% (95% CI: 12.2-13.3)] and one in three mid-age women [36.1% (CI: 35.2-37.0)] and older women [35.0% (CI: 34.1-35.9)]. Leaking urine was significantly associated with parity, conditions which increase the pressure on the pelvic floor such as constipation and obesity, past gynecological surgery and conditions which can impact on bladder control. The study showed that fewer than half the women had sought help for the problem and that younger women were less likely to be satisfied with the help available for this problem. Strategies for continence promotion, including opportunistic raising of the issue at the time of cervical screening and pregnancy care are suggested, so that the health and social outcomes of untreated chronic incontinence in women might be improved.

Leaking urine: Prevalence and associated factors in Australian women

The Women's Health Australia project provided the opportunity to examine the prevalence of leaking urine and associated variables in three large cohorts of Australian women 18-23 years of age (young N = 14,761), 45-50 (mid-age N = 14,070), and 70-75 (older N = 12,893). The proportion of women reporting leaking urine was 12.8% (95% CI: 12.2-13.3), 36.1% (35.2-37.0), and 35% (34.1-35.9) in each of the three cohorts, respectively. Logistic regression analysis showed significant associations between leaking urine and parity in the young and mid-age women, and between leaking urine and constipation, other bowel symptoms, body mass index, and urine that burns or stings in all three groups. in the mid-age and older cohorts, women who reported having both hysterectomy and prolapse repair, or prolapse repair alone, were also more likely to report leaking urine. Lower scores on the physical and mental component summary scores of the medical outcomes survey short form (36 items) questionnaire suggest lower quality of life among women who report leaking urine, compared with those who do not. (C) 1999 Wiley-Liss,Inc.

Excretion of ammonia by Lucilia cuprina larvae suppresses immunity in sheep

Attempts to immunise sheep against natural infestations by Lucilia cuprina larvae have not been effective. Yet it is known that the larvae excrete the immunosuppressant ammonium bicarbonate. The effect of larval ammonium and nonionic ammonia on immunopathobiology was evaluated in 12 infested sheep. The concentration of ammonium in veins draining infested sites was measured in another group of four sheep. Mean jugular unionized ammonia concentration increased 3.5 to 5.6 times above pre-infested control levels. Mean venous ammonium concentrations draining infested sites were 13 times higher than pre-infested jugular or carotid levels. Increases in jugular ammonia concentrations correlated with increased number of larvae, area of infestation, earlier death, neutropenia, eosinopenia, lymphocytopenia, large declines in serum globulins and zinc, and large rises in toxic neutrophils. The high concentrations of toxic unionized ammonia in blood directly permanently damaged neutrophils and lymphocytes and depressed serum globulin production. The results show that the ammonium from the excreta of larvae of L. cuprina may be highly immunosupressive. (C) 1997 Elsevier Science B.V.

Valproic acid has temporal variability in urinary clearance of metabolites

The reasons for the intra- and interindividual variability in the clearance of valproic acid (VPA) have not been completely characterized. The aim of this study was to examine day-night changes in the clearance of 3-oxo-valproate (3-oxo-VPA), 4-hydroxy-valproate (4-OH-VPA), and valproic acid glucuronides under steady state. Six diurnally active healthy male volunteers ingested 200 mg sodium valproate 12 hourly, at 0800 and 2000, for 28 days. On the last study day, two sequential 12-h urine samples were collected commencing at 2000 the evening before. Plasma samples were obtained at the end of each collection. Following alkaline hydrolysis, urine was analyzed for concentrations of VPA, 3-oxo-VPA, and 4-OH-VPA. A separate aliquot was assayed for creatinine (CR). The plasma concentrations of VPA, 3-oxo-VPA, 2-en-VPA, and CR were determined. The analysis of VPA and its metabolites was performed by CC-MS. There was an increase in plasma 3-oxo-VPA concentration at 0800, sampling as compared to 2000 sampling (p < .05). The urinary excretion of 3-oxo-VPA and VPA glucuronides were decreased between 2000 and 0800, compared to between 0800, and 2000, by 30% and 50% respectively (p < .05). These results indicate a nocturnal decrease in renal clearance of 3-oxo-VPA rather than a decrease in the beta -oxidation of VPA at night. These differences were not explained by differences between the sampling periods in CR excretion. These results indicate the importance of collecting samples of 24-h duration when studying metabolic profiles of VPA.

Rearrangement of diflunisal acyl glucuronide into its beta-glucuronidase-resistant isomers facilitates transport through the small intestine to the colon of the rat

Many non-steroidal anti-inflammatory drugs (NSAIDs) which form acyl glucuronide conjugates as major metabolites have shown an antiproliferative effect on colorectal tumors. This study assesses the extent to which rearrangement of an acyl glucuronide metabolite of a model NSAID into beta -glucuronidase-resistant isomers facilitates its passage through the small intestine to reach the colon. Rats were dosed orally with diflunisal (DF), its acyl glucuronide (DAG) and a mixture of rearrangement isomers (iso-DAG) at 10 mg DF equivalents/kg. The parent drug DF appeared in plasma after all doses, with maximum concentrations of 20.5 +/- 2.5, 28.8 +/- 8.3 and 11.0 +/- 1.6 mug DF/ml respectively, obtained at 3.8 +/- 0.3, 3.6 +/- 1.8 and 7.5 +/- 0.9 hr after the DF, DAG and iso-DAG doses respectively. At 48 hr, 16.2 +/- 3.3, 19.8 +/- 0.8 and 42.9 +/- 10.1% of the doses respectively were recovered in feces, with less than or equal to 1% remaining in the intestine. About half of each dose was recovered as DF and metabolites in 48 hr urine: for DF and DAG doses, the majority was in the first 24 hr urine. whereas for iso-DAG doses, recoveries in the first and second 24 hr periods were similar. The results show that hydrolysis of both DAG and iso-DAG, and absorption of liberated DF, occur during passage through the gut, but that these processes occur more slowly and to a lesser degree for iso-DAG. The intrinsic hydrolytic capacities of various intestinal segments (including contents) towards DAG and iso-DAG were obtained by incubating homogenates under saturating concentrations of DAG/iso-DAG at 37 degreesC. Upper small intestine, lower small intestine, caecum and colon released 2400, 3200, 9200 and 22800 mug DF/hr/g tissue plus contents respectively from DAG substrate, and 18, 10, 140 and 120 mug DF/hr/g tissue plus contents respectively from iso-DAG substrate. The much greater resistance of iso-DAG to hydrolysis appears attributable to its resistance to beta -glucuronidases. The data suggest that in rats dosed with DF, DAG excreted in bile would be substantially hydrolysed in the small intestine and liberated DF reabsorbed, but that portion which rearranges to iso-DAG would likely reach the colon. (C) 2001 Elsevier Science Inc. All rights reserved.

Too wet to exercise? Leaking urine as a barrier to physical activity in women

Leaking urine Is frequently mentioned (anecdotally) by women as a barrier to physical activity. The aim of this paper was to use results from the Australian Longitudinal Study on Women's Health (ALSWH) to explore the prevalence of leaking urine in Australian women, and to ascertain whether leaking urine might be a barrier to participation for women. More than 41,000 women participated in the baseline surveys of the ALSWH in 1996. More than one third of the mid-age (45-50 years) and older (70-75) women and 13% of the young women (18-23) reported leaking urine. There was a cross-sectional association between leaking urine and physical activity, such that women with more frequent urinary leakage were also more likely to report low levels of physical activity. More than one thousand of those who reported leaking urine at baseline participated in a follow-up study in 1999. Of these, more than 40% of the mid-age women (who were aged 48-53 in 1999), and one in seven of the younger (21-26 years) and older (73-79 years) women reported leaking urine during sport or exercise. More than one third of the mid-age women and more than one quarter of the older women, but only 7% of the younger women said they avoided sporting activities because of leaking urine. The data are highly suggestive that leaking urine may be a barrier to physical activity, especially among mid-age women. As current estimates suggest that fewer than half of all Australian women are adequately active for health benefit, health professionals could be more proactive in raising this issue with women and offering help through non-invasive strategies such as pelvic floor muscle exercises.

Urine D-arabinitol/L-arabinitol ratio in diagnosing Candida infection in patients with haematological malignancy and HIV infection

Adult patients with hematologic malignancies along with HIV infected patients were prospectively studied to determine the performance of urine D-arabinitol/L-arabinitol (DA/LA) ratio in diagnosing invasive candidiasis. Ten evaluable febrile neutropenic patients had proven invasive candidiasis and elevated DA/LA ratios were found in 5. Invasive candidiasis with normal DA/LA ratios was most frequently due to Candida krusei infection. This Candida species is a non-producer of arabinitol. Only 4 of 81 febrile neutropenic patients given either antifungal prophylaxis or empiric antifungal treatment had elevated DA/LA ratios. Only 1 of 15 HIV positive patients with either oropharyngeal or esophageal candidiasis had elevated DA/LA ratios. Widespread use of fluconazole prophylaxis in bone marrow transplantation patients at the study hospital has led to an increased prevalence of C. krusei infection. This is the likely reason for the low sensitivity of the test in proven and suspected invasive Candida infections reported here. (C) 2002 Elsevier Science Inc. All rights reserved.