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This study assessed the composition of single-use face mask materials, quantified the concentration of phthalate esters in masks and evaluated associated inhalation exposure risk. All the mask samples, including 12 surgical and four N95/P1/P2 masks, were identified to be made of polypropylene, with polyethylene terephthalate present in the N95/P1/P2 masks. Di-methyl phthalate, di-n-butyl phthalate, di-ethyl phthalate, di-isobutyl phthalate and di(2-ethylhexyl) phthalate were frequently detected and their concentration summed up 55 ± 35 ~ 1700 ± 140 ng per surgical mask and 2300 ± 150 ~ 5200 ± 800 ng per N95/P1/P2 mask. Our simulation experiment suggested a mean loss of 13 - 71% of phthalate mass depending on compounds, during 5-hour wearing of these masks. This resulted in an estimated daily intake of individual compounds no higher than 20 ng/kg/day for adults and 120 ng/kg/day for toddlers, which were at least 80 times lower compared to relevant tolerable daily intake values. Two interventional trials were conducted where a volunteer wore a mask for four hours and urine samples were collected before and after the mask wearing. No obvious increase was observed for the urinary concentration of any phthalate metabolite, indicating minimal contribution to overall exposure to phthalate esters.

Urinary analyte data has to be corrected for the sample specific dilution as the dilution varies intra- and interpersonally dramatically, leading to non-comparable concentration measures. Most methods of dilution correction utilized nowadays like probabilistic quotient normalization or total spectra normalization result in a division of the raw data by a dilution correction factor. Here, however, we show that the implicit assumption behind the application of division, log-linearity between the urinary flow rate and the raw urinary concentration, does not hold for analytes which are not in steady state in blood. We explicate the physiological reason for this short-coming in mathematical terms and demonstrate the empirical consequences via simulations and on multiple time-point metabolomic data, showing the insufficiency of division-based normalization procedures to account for the complex non-linear analyte specific dependencies on the urinary flow rate. By reformulating normalization as a regression problem, we propose an analyte specific way to remove the dilution variance via a flexible non-linear regression methodology which then was shown to be more effective in comparison to division-based normalization procedures. In the progress, we developed several, easily applicable methods of normalization diagnostics to decide on the method of dilution correction in a given sample. On the way, we identified furthermore the time-span since last urination as an important variance factor in urinary metabolome data which is until now completely neglected. In conclusion, we present strong theoretical and empirical evidence that normalization has to be analyte specific in dynamically influenced data. Accordingly, we developed a normalization methodology for removing the dilution variance in urinary data respecting the single analyte kinetics.

This cross-sectional study explores the relationships between children's F(-) exposure from drinking groundwater and urinary F(-) concentrations, combined with dental fluorosis (DF) in the Main Ethiopian Rift (MER) Valley. We examined the DF prevalence and severity among 491 children (10 to 15 years old) who are life-long residents of 33 rural communities in which groundwater concentrations of F(-) cover a wide range. A subset of 156 children was selected for urinary F(-) measurements. Our results showed that the mean F(-) concentrations in groundwater were 8.5 ± 4.1 mg/L (range: 1.1-18 mg/L), while those in urine were 12.1±7.3 mg/L (range: 1.1-39.8 mg/L). The prevalence of mild, moderate, and severe DF in children's teeth was 17%, 29%, and 45%, respectively, and the majority (90%; n=140) of the children had urinary F(-) concentrations above 3 mg/L. Below this level most of the teeth showed mild forms of DF. The exposure-response relationship between F(-) and DF was positive and non-linear, with DF severity tending to level off above a F(-) threshold of ~6 mg/L, most likely due to the fact that at ~6 mg/L the enamel is damaged as much as it can be clinically observed in most children. We also observed differential prevalence (and severity) of DF and urinary concentration, across children exposed to similar F(-) concentrations in water, which highlights the importance of individual-specific factors in addition to the F(-) levels in drinking water. Finally, we investigated urinary F(-) in children from communities where defluoridation remediation was taking place. The lower F(-) concentration measured in urine of this population demonstrates the capacity of the urinary F(-) method as an effective monitoring and evaluation tool for assessing the outcome of successful F(-) mitigation strategy in relatively short time (months) in areas affected with severe fluorosis.

The aim of this review is to evaluate the impact of sleep on breast cancer risk. Given the supposed protective role played by melatonin in breast cancer, it is interesting to study the effect of sleep, which is the moment of melatonin synthesis. Articles were extracted from the PUBMED database between 2000 and 2012 with the following keywords "sleep duration", "sleep quality", "breast cancer risk" and "melatonin". In total, 10 articles were selected. Most prospective cohort studies found a decrease in the risk of breast cancer varying from 38 to 72% for "long sleepers". Furthermore, a meta-analysis of the studies assessing the link between breast cancer risk and urinary concentration of 6-sulfatoxy-melatonin (6MT), which is melatonin's main metabolite, found a 34% decrease for patients with the highest 6MT concentration. Even though other studies are necessary to confirm these results, it seems already adequate to detect sleep disorders and to try to treat them.

EPO and α-MSH prevent ischemia/reperfusion-induced down-regulation of AQPs and sodium transporters in rat kidney. Background Ischemia-induced acute renal failure (ARF) is known to be associated with significant impairment of urinary concentrating ability and down-regulation of renal aquaporins (AQPs) and sodium transporters in rats. We tested whether treatment with erythropoietin (EPO) or α-melanocyte-stimulating hormone (α-MSH) in combination with EPO reduces the renal ischemia/reperfusion (I/R) injury and prevents the down-regulation of renal AQPs and major sodium transporters. Methods I/R-induced ARF was established in rats by 40-minute temporary bilateral obstruction of renal arteries, and rats were kept in metabolic cages for urine measurements. After 2 or 4 days following EPO and/or α-MSH treatment, kidneys were removed to determine the expression levels of AQPs and sodium transporters by semiquantitative immunoblotting. Results Rats with ARF showed significant renal insufficiency, increased urine output, and high fractional excretion of urinary sodium. Consistent with this, immunoblotting and immunocytochemistry revealed that the kidney expression of AQPs (AQP-1, -2 and -3) and sodium transporters [Na,K-ATPase, rat type 1 bumetanide-sensitive Na-K-2Cl cotransporter (BSC-1), Na/H exchanger type 3 (NHE3), and thiazide-sensitive sodium chloride cotransporter (TSC)] in ARF rats was significantly decreased compared to sham-operated control rats. In contrast, EPO treatment at the time of ischemia of rats with ARF significantly prevented the ischemia-induced down-regulation of renal AQPs and sodium transporters and in parallel improved the urinary concentrating capability and renal sodium reabsorption. Importantly, similar effects were observed following the initiation of EPO or α-MSH treatment 4 hours after the onset of ischemia injury. Moreover, the combination of EPO with α-MSH potentiated the beneficial effects of single compound treatment. Conclusion EPO and/or α-MSH treatment significantly prevent I/R-induced injuries such as urinary-concentrating defects and down-regulation of renal AQPs and sodium transporters.

Concentrations of serum or urinary type IV collagen, determined by sandwich enzyme immunoassay, were significantly elevated in diabetics compared to controls (P less than .01). Serum or urinary levels of type IV collagen were significantly increased in patients with microangiopathy compared to those without microvascular disease (P less than .05). Serum type IV collagen levels were also augmented in diabetics who showed an increased albumin index for 1 year. Serum levels of type IV collagen were not affected by any conditions of metabolic control. The measurement of serum or urinary type IV collagen may be a useful indicator for monitoring the development of diabetic microangiopathy, especially in early diabetic nephropathy.

The adsorption in humans of nitrofurantoin from seven suppository bases was studied using urinary excretion measurements. Rectal absorption was poorer than GI absorption. The administration of 400 mg of nitrofurantoin in a polyethylene glycol-polysorbate 80 suppository base and in a polyethylene glycol-silica suppository based provided an adequate urinary concentration of nitrofurantoin. Persons who cannot tolerate orally administered nitrofurantoin due to gastric upset could receive nitrofurantoin therapy rectally.

Cinoxacin, an orally administered synthetic antimicrobial agent, is highly effective in the treatment of urinary tract infections caused by most urinary tract pathogens. Its high prolonged urinary concentration, low incidence of adverse reactions, low fecal concentration, infrequent induction of resistant bacterial strains, and broad antimicrobial spectrum are valuable attributes. Its efficacy for prolonged low-dose preventive therapy of frequently recurring infections adds to this new drug's importance.

Groups of 15 male and 15 female rats were fed diet containing 0 (control), 1, 5 or 10% carnauba wax or 10% cellulose powder for 13 wk and groups of five rats of each sex were given these treatments, except the 1% carnauba wax, for 2 or 6 wk. Rats given 10% carnauba wax or 10% cellulose consumed more food than the controls but showed no differences in body weight, an effect attributed to the dilution of the diet by non-nutrient test materials. The study showed no treatment-related differences in body weights, water intakes, haematological values, serum-enzyme activities, urinary concentration and 'dilution' tests, organ weights or histological findings. The no-untoward-effect level for carnauba wax in the diet was 10%, which represented a mean intake of approximately 8.8 and 10.2 g/kg body weight/day in males and females, respectively.

The renal excretion of cystathionine is not age-dependent when related to body surface. Regarding the urinary creatinine concentration as reference, the excretion of cystathionine in adults is lower than in infants and children. However, this is probably due to a higher urinary concentration of creatinine in adults compared to that in children. Premature infants excrete more cystathionine in their urine than mature infants. The same is true for premature infants on a methionine-enriched formula compared to premature infants on a low methionine formula.

We have analyzed the histotopography of the renal medulla of the rat in terms of cycles and separations. Cycles are pathways by which solute leaving the medulla in an ascending structure (AVR, AHL) is returned to a deeper medullary level. Separations are based on spatial incontiguity and special characteristics of the interstitium and blood supply. The two concepts are complementary: the compartmentalization resulting from separations imparts specificity to the cycles. Structural lateral heterogeneity, consisting in distinct domains organized around vascular bundles, is present in one form or another in all three medullary zones. Such compartmentalization probably leads to heterogeneity in interstitial solute concentrations, a state of affairs inconsistent with the requirements of a "central core". In all such considerations of exchanges between compartments, the lack of a unitary interstitium must be borne in mind. Instead, three general types of interstitium may be distinguished: corresponding roughly to those of the OS and VB, the interbundle region of the IS, and the IM. Among the histotopographic features of the renal medulla not usually included in models of the urinary concentrating mechanism but likely to have functional significance are the association of CD with completely distinct populations of AVR and AHL in the OM and IM; a clear-cut separation throughout the medulla between cycles involving long loops and those involving short loops; the lack of an effective countercurrent association between ascending and descending limbs of short loops in the IS; and a pronounced separation of the venous drainage of the IM from that of the OM.

The etiopathogenesis of uric acid, sodium acid urate, and ammonium acid urate uroliths in non-Dalmatian dogs appears to be a complex phenomenon. It may involve one or more pathologic and/or physiologic processes acting independently or in concert to increase urinary concentration of lithogenic substances that result in initiation, growth, and retention of urate uroliths. Increased urine uric acid concentration and/or urinary excretion of uric acid appear to be primary predisposing factors in urate lithogenesis. Specific disorders resulting in hyperuricuria may involve abnormalities of increased synthesis, diminished biodegradation, and/or enhance excretion of uric acid. In addition, ammonium ion, hydrogen ion, and other organic and inorganic urine constituents appear to have major influences on urate urolith formation. Unfortunately, many specific disorders of uric acid metabolism and other factors promoting or inhibiting urate urolith formation remain poorly characterized in the majority of non-Dalmatian dogs with urate urolithiasis. Growing awareness of the significance of urate uroliths in non-Dalmatian dogs should encourage further investigation into the identification, characterization, and quantitation of parameters influencing urate lithogenesis. Results of such studies are required for development of practical and effective strategies for treatment and prevention of canine urate urolithiasis.

This communication describes the use of droperidol in methamphetamine poisoning. Droperidol antagonizes the central stimulatory effects of amphetamines producing a person who is indifferent to environmental stimuli, calm and cooperative. Coupled with an acid diuresis, causing a fivefold increase in the urinary concentration of methamphetamine and recovery of 66% of the ingested drug, a seriously intoxicated patient showed rapid improvement.

Yellow 2G was fed to rats at dietary levels of 0 (control), 100, 1000 or 10,000 ppm for 13 wk. The colouring was decolorized in the caecum, but the colourless product turned red on exposure to the air. No adverse effects were seen in the rate of body-weight gain, or in the results of haematological examinations, serum chemistry, renal cell excretion and urinary concentration tests. No gross or micropathological effects were detected which could be attributed to the colouring. There were isolated changes in the weights of kidney, small intestine, adrenal glands and testes in rats receiving 1000 or 10,000 ppm Yellow 2G but these were not considered to be related to treatment. The caeca were enlarged in rats fed a diet containing 10,000 ppm. The no-adverse-effect level suggested is 1000 ppm (or approximately 80 mg/kg/day), a level 2000 times the expected human intake.

The aim of our study was to check whether any real gain is attained by determining the output of a urinary solute in relation to the output of creatinine, or whether it is sufficient to express the solute output in relation to the 24-h volume of urine, i.e . in conventional form as concentration in urine. The 24-h output of creatinine and the 24-h urinary volume were determined in 35 patients, with observation times varying from 7 to 41 days. All patients were on a mixed diet with intakes of creatine varying from day to day. A statistical method for the comparison of differences between coefficients of variation was worked out and applied. This method yielded a t value of −1.59 with 34 degrees of freedom; i.e ., the variations in creatinine output were of the same order as the variations of the 24-h urinary output. Judging from the present material it seems safe to conclude that in individuals on a mixed diet no advantage is gained by expressing the output of solutes in relation to creatinine output, and that the simpler expression in terms of urinary concentration is sufficient.

Summary Six extensively burnt patients with h˦moglobinuria and established or impending renal failure are described. In the last four, permanent renal damage and anuria were averted by the induction of a solute diuresis with either polyvinylpyrrolidone or mannitol. A solute diuresis exerts its effect by increasing the distal tubule urinary flow and by reducing urinary concentration, thus permitting the excretion of toxic products of blood destruction without renal damage.

An appreciation of the factors controlling the radiopacity of the urine during intravenous urography has followed the careful study of the hydration of the patient and the dose and nature of the contrast agent. The value of preliminary dehydration has been confirmed. The suspicion that it was not always effective, led to an evaluation of the use of Lypressin (Anti-Diuretic Hormone) in urography. It is found that A.D.H. increases the urinary concentration of the contrast medium and therefore improves the quality of the pyelogram. This improvement is most marked when there has been limited dehydration.

Urines of athletes were collected after a cross-country and concentrated. After a chromatographic separation on a DEAE-cellulose column, two fractions are isolated in the gamma range, the γ g -globulin and the γ l -globulin. The urinary γ g is similar to the serum γ g and the γ l -globulin appears with a sedimentation constant of 1.4 S. The urinary concentration of the latter rises notably after physical exertion.

Summary Serum and urinary phenylbutazone (PBZ) concentrations were measured for eight Thoroughbred mares following four daily oral doses and one IV dose of PBZ per mare. Urine flow was estimated from urinary creatinine concentration. The serum PBZ concentration significantly correlated with the urinary concentration, but only about half of the variation in serum PBZ concentrations was explained by the linear relationship with urinary PBZ concentration (R 2 =0.48). Correlation of serum PBZ concentration with urinary PBZ excretion, which was estimated using urinary creatinine concentration, over half of the variation in serum PBZ concentrations: (R 2 =0.60).

The use of dehydration in patients undergoing intravenous urography remains widespread, despite evidence that it may be dangerous and despite lack of evidence of any effect on the urinary concentration of contrast media. In total, 100 patients were studied, having been allocated randomly into two groups, one of which had undergone dehydration, the other group being normally hydrated. No significant difference in the quality of the urograms was detected. It is suggested that the practice of dehydration in preparation is unnecessary and should no longer be undertaken.

Paired intravenous pyelograms were compared in each of twelve patients with and without overnight fluid deprivation. Urinary concentration of contrast medium and calyceal detail were significantly improved with dehydration. Short-term fluid deprivation is of value even in large-dose urography for patients with adequate renal function.