Additive-manufactured paper-PMMA hybrid microfluidic chip for simultaneous monitoring of creatinine and pH in artificial urine.

Nowadays, kidney dysfunction is a common health issue due to the modernized lifestyle. Even though medications are commercially available to treat kidney diseases, early diagnosis is crucial and challenging. Clinically, measuring urine creatinine and pH has gained significant interest as a way to diagnose kidney diseases early. In the present work, we attempted to develop a low-cost, robust, accurate and naked-eye colorimetric method to determine both creatinine levels and pH variations in artificial urine samples using a simple 3D-printed hybrid microfluidic device. Creatinine was detected by the incorporation of the traditional Jaffe test onto the hybrid paper-PMMA microfluidic device and pH (4-8) was measured by a simple anthocyanin test. Notably, the tests were established without employing any sophisticated or costly instrument clusters. The developed 3D-printed microfluidic probe showed a limit of detection (LOD) of 0.04 mM for creatinine over a concentration range of 1-10 mM, with a regression coefficient (R2) of 0.995 in laboratory conditions. Interestingly, the experimental data obtained with artificial urine exhibited a wide linear range from 0.1 mM to 5 mM under different pH values ranging from 4 to 8 in the presence of matrices commonly found in urine samples other than proteins, indicating the potential use of this method in pre-clinical analysis. Since the wide linear range of urine creatinine in artificial urine samples falls well below the clinically relevant concentrations in humans (0.07-0.27 mM), the developed lab-on-chip device is further suitable for clinical evaluation with proper ethical clearance. This 3D-printed hybrid microfluidic colorimetry-based creatinine detection and pH indicator platform can be beneficial in the healthcare sector due to the on-site testing capability, cost-effectiveness, ease of use, robustness, and instrument-free approach.

Long-term Association of Periodontitis With Decreased Kidney Function.

RATIONALE & OBJECTIVE: Previous studies have yielded inconclusive findings regarding the relationship between periodontitis and kidney function. We sought to investigate whether periodontitis is associated with subsequent decreases in kidney function (reductions in estimated glomerular filtration rate [eGFR] and increased urinary albumin-creatinine ratio [UACR]) in the general population. STUDY DESIGN: Population-based cohort study. SETTING & PARTICIPANTS: We used baseline and 11-year follow-up data from 2,297 and 1,512 adult participants, respectively, in the Study of Health in Pomerania (SHIP). Age range was limited to 20 to 59 years to avoid the potential influence of tooth loss. EXPOSURES: Periodontal status defined by periodontal pocket probing depth (PPD) and clinical attachment level. Mean levels and the percentage of sites ≥ 3mm was determined for either all sites (PPD) or interproximal sites (clinical attachment level). All PPDs≥4mm were summed to calculate the total PPD. OUTCOMES: GFR estimated from serum creatinine and serum cystatin C (eGFRcr-cys). Moderately increased albuminuria defined as UACR>30mg/g. ANALYTICAL APPROACH: Adjusted linear and logistic mixed regression models. RESULTS: At baseline and follow-up, average eGFRcr-cys was 118.3 and 105.0mL/min/1.73m2, respectively. Using mixed models, no consistently significant associations between periodontitis variables and eGFRcr-cys were detected. Long-term changes in UACR were inconsistently associated with periodontitis measures. After imputation of missing data, associations were either attenuated or no longer detectable. LIMITATIONS: Because periodontal assessments were performed using a partial recording protocol, periodontal disease severity estimates might have been underestimated, resulting in attenuated effect estimates. CONCLUSIONS: We found no consistent evidence for an association between periodontitis and decreased kidney function. In contrast to previous studies, these results do not support the hypothesis that periodontitis is an important risk factor for chronic kidney disease.

Assessing the impact of inadequate hydration on isotope-GFR measurement.

Guidelines state that patients undergoing isotope glomerular filtration rate (GFR) tests should maintain adequate hydration, but pragmatically these tests can coincide with procedures requiring the patient not to eat or drink ('nil-by-mouth') for up to 12 hours beforehand. This study investigated the impact of a 12-hour nil-by-mouth regime on GFR measurement. Twelve healthy volunteers were recruited from our institution. Exclusion criteria included diabetes mellitus, being under 18 years of age and pregnancy. Isotope GFR measurements were carried out on these volunteers twice. One of the tests adhered strictly to the British Nuclear Medicine Society (BNMS) guidelines for GFR measurement and the other test was carried out after the volunteers had refrained from eating or drinking anything for 12 hours. The order of these tests was randomly assigned. The results show that after a nil-by-mouth regime, participants' average absolute GFR fell from 108 ml/min to 97 ml/min (p < .01), while normalised GFR fell from 97 ml/min/1.73 m2 to 88 ml/min/1.73m2 (p < .01). Serum creatinine rose from 68 mmol/L to 73 mmol/L (p < .05). There were no changes in blood pressure, serum hydration markers or bio-impedance measured fluid status. Urine analysis showed statistically significant increases in urea, creatinine and osmolality levels after the nil-by-mouth regime. The results highlight the importance of following current guidelines recommending fluid intake during the procedure. Practitioners should consider what other outpatient appointments are being scheduled concurrently with a GFR test.

Development of a fast method for simultaneous determination of hippuric acid, mandelic acid, and creatinine in urine by capillary zone electrophoresis using polymer multilayer-coated capillary.

This paper reports the development of a fast separation method employing capillary zone electrophoresis for the simultaneous determination of hippuric acid, mandelic acid, and creatinine in samples of urine using a coated capillary. The background electrolyte was composed of 10 mmol L-1 tris(hydroxymethyl)aminomethane and 30 mmol L-1 2-hydroxy-isobutyric acid at pH 3.6. The internal standard was 3,5-dihydroxybenzoic acid. Separations were performed in a fused silica capillary (32 cm total length, 8.5 cm effective length, and 50 µm internal diameter) coated with crosslinked hydroxypropyltrimethyl ammonium chloride chitosan and κ-carrageenan. Direct UV detection was performed at a wavelength of 200 nm. Samples and standards were injected hydrodynamically (-50 mbar, 3 s) using the short-end injection procedure. The electrophoretic system was operated under constant voltage of 30 kV with positive polarity on the injection side. The separation time for hippuric acid, mandelic acid, and creatinine was less than 70 s. The evaluation of some analytical parameters of the method for the three analytes showed good linearity (R 2 > 0.99), limit of detections of 0.21 to 0.63 mg L-1, inter-day precision better than 3.0% (peak area), and recovery in the range of 98 to 106%. The method developed was applied in the analysis of the three analytes in urine samples. Graphical Abstract New method using capillary zone electrophoresis for analysis of creatinine, hippuric acid and mandelic acid in urine.

Association Between Periodontitis and Low-Grade Albuminuria in Non-Diabetic Adults.

BACKGROUND/AIMS: The objective of the present study was to evaluate the clinical association between periodontitis and a high urinary albumin/creatinine ratio (UACR) in individuals without diabetes mellitus. METHODS: Data from the Korean National Health and Nutrition Examination Survey were used for this analysis. A high UACR was defined as UACR≥3.9 mg/g for men and UACR≥7.5 mg/g for women. The WHO community periodontal index (CPI) was used to define periodontitis and assess its severity. RESULTS: The numbers of participants without and with periodontitis were 3,046 and 8,571, respectively. The UACR values were higher in participants with periodontitis than in those without periodontitis. Logistic regression showed that the OR for a high UACR with the presence of periodontitis was 1.14 (P=0.044) on multivariate analysis. CPI score was positively associated with UACR. CONCLUSIONS: Periodontitis was associated with UACR in the non-diabetic participants in this study. Therefore, participants with periodontitis should be closely monitored for UACR, which can function as an early marker for renal injury.

Urinary bisphenol A is associated with dysregulation of HPA-axis function in pregnant women: Findings from the APrON cohort study.

BACKGROUND: Bisphenol A (BPA) is associated with dysregulation of hypothalamic-pituitary-adrenal (HPA) axis activity in rodents, but evidence in humans is lacking. OBJECTIVE: To determine whether BPA exposure during pregnancy is associated with dysregulation of the HPA-axis, we examined the association between urinary BPA concentrations and diurnal salivary cortisol in pregnant women. Secondary analyses investigated whether the association between BPA and cortisol was dependent on fetal sex. METHODS: Diurnal salivary cortisol and urinary BPA were collected during pregnancy from 174 women in a longitudinal cohort study, the Alberta Pregnancy Outcomes and Nutrition (APrON) study. Associations between BPA and daytime cortisol and the cortisol awakening response (CAR) were estimated using mixed models after adjusting for covariates. RESULTS: Higher concentrations of total BPA uncorrected for urinary creatinine were associated with dysregulation of the daytime cortisol pattern, including reduced cortisol at waking, ß=-.055, 95% CI (-.100, -.010) and a flatter daytime pattern, ß=.014, 95% CI (.006, .022) and ß=-.0007 95% CI (-.001, -.0002) for the linear and quadratic slopes, respectively. Effect sizes in creatinine corrected BPA models were slightly smaller. None of the interactions between fetal sex and BPA were significant (all 95% CI's include zero). CONCLUSIONS: These findings provide the first human evidence suggesting that BPA exposure is associated with dysregulation of HPA-axis function during pregnancy.

Fractional Urinary Fluoride Excretion (FUFE) of 3-4 year children in the Gaza Strip.

UNLABELLED: A positive association between dental fluorosis prevalence and fluoride (F) concentration in drinking waters has been detected in Gaza Strip. Total Daily Fluoride Retention (TDFR), and Fractional Urinary Fluoride Excretion (FUFE) indicate F body burden; important in assessing fluorosis risk in susceptible age groups. OBJECTIVE: 1, To determine and compare Daily Urinary Fluoride Excretion (DUFE) and FUFE of 3-4-year-olds living in lower (< 0.7), moderate (0.7-1.2) or higher (> 1.2 ) ppm F tap water areas; 2, To determine any relationship between i, DUFE and tap water F; ii, DUFE and Total Daily Fluoride Intake (TDFI); iii, TDFI and TDFR. METHODS: 24-hour urine and tap water samples were collected from 216 children exposed to lower (n = 81), moderate (n = 72), or higher (n = 63) tap water F. ANOVA with Tukey's Test and Pearson's correlation were used to examine differences in mean DUFE and FUFE and relationships between variables. RESULTS: Mean drinking water F was 0.11(sd 0.17), 0.14 (sd 0.28) and 0.38 (sd 0.63) ppmF respectively. Differences (p < 0.0001) in mean DUFEs (0.17 (sd 0.13), 0.25 (sd 0.15) and 0.38 (sd 0.23) mg/day respectively) and mean FUFEs (48 (sd 39)%, 47 (sd 31)% and 63(sd 76)%) were found (p < 0.05). Significant (p < 0.0001) positive correlations were found between DUFE and tap water F; DUFE and TDFI, and; TDFI and TDFR. CONCLUSION: DUFEs of children drinking waters with 0.11 and 0.14ppm F, represented low F usage. The group drinking 0.38ppm F water represented optimal F usage. The weak significant positive association of DUFE with home tap water F suggests low validity for tap water F in estimating F exposure.

The 10:00-11:00 pm urine cortisol/creatinine ratio. An alternative to late-night salivary cortisol for the diagnosis of Cushing's syndrome.

The aim of this study was to investigate interchangeability of two tests to diagnose Cushing's syndrome. We compared 10:00-11:00 PM urinary free cortisol/creatinine ratio (UFC/Cr) with late night 11:00 PM salivary cortisol (LNSC) in normal and obese controls vs. patients with Cushing's syndrome. Mean UFC/Cr did not differ between 69 normal and 62 obese controls (9.9 ± 7.9 vs. 9.7 ± 9.3) whereas 116 Cushing's patients had significantly higher values (277.0 ± 318.0; z: -11.1 and -10.2, respectively; p < 0.001). LNSC was 1.9 ± 1.2 nmol/l in 44 normal and 2.5 ± 1.6 in 45 obese subjects with no differences between them, but was significantly higher in 47 Cushing's patients (24.8 ± 23.3; z: -7.22 and -6.96, respectively, p < 0.001). Comparison of UFC/Cr and LNSC in samples obtained simultaneously showed that UFC/Cr was 12.0 ± 8.7 ng cortisol/mg creatinine in 34 normal, 12.3 ± 8.9 in 40 obese and 319.5 ± 333.4 in 35 CS subjects (p < 0.001 vs. normal and obese), whereas LNSC was 1.8 ± 1.2 nmol/l in normal, 2.6 ± 1.7 in obese and 24.6 ± 17.4 in CS patients (p < 0.001 vs. normal and obese); ROC curves showed comparable high sensitivity and specificity figures for the diagnosis of CS. We concluded that UFC/Cr test is easy to perform, readily available in routine laboratories, has high sensitivity and specificity, and offers a valuable alternative to LNSC in the study of Cushing's syndrome.

Plasma, salivary and urinary cortisol levels following physiological and stress doses of hydrocortisone in normal volunteers.

BACKGROUND: Glucocorticoid replacement is essential in patients with primary and secondary adrenal insufficiency, but many patients remain on higher than recommended dose regimens. There is no uniformly accepted method to monitor the dose in individual patients. We have compared cortisol concentrations in plasma, saliva and urine achieved following "physiological" and "stress" doses of hydrocortisone as potential methods for monitoring glucocorticoid replacement. METHODS: Cortisol profiles were measured in plasma, saliva and urine following "physiological" (20 mg oral) or "stress" (50 mg intravenous) doses of hydrocortisone in dexamethasone-suppressed healthy subjects (8 in each group), compared to endogenous cortisol levels (12 subjects). Total plasma cortisol was measured half-hourly, and salivary cortisol and urinary cortisol:creatinine ratio were measured hourly from time 0 (between 0830 and 0900) to 5 h. Endogenous plasma corticosteroid-binding globulin (CBG) levels were measured at time 0 and 5 h, and hourly from time 0 to 5 h following administration of oral or intravenous hydrocortisone. Plasma free cortisol was calculated using Coolens' equation. RESULTS: Plasma, salivary and urine cortisol at 2 h after oral hydrocortisone gave a good indication of peak cortisol concentrations, which were uniformly supraphysiological. Intravenous hydrocortisone administration achieved very high 30 minute cortisol concentrations. Total plasma cortisol correlated significantly with both saliva and urine cortisol after oral and intravenous hydrocortisone (P <0.0001, correlation coefficient between 0.61 and 0.94). There was no difference in CBG levels across the sampling period. CONCLUSIONS: An oral dose of hydrocortisone 20 mg is supraphysiological for routine maintenance, while stress doses above 50 mg 6-hourly would rarely be necessary in managing acute illness. Salivary cortisol and urinary cortisol:creatinine ratio may provide useful alternatives to plasma cortisol measurements to monitor replacement doses in hypoadrenal patients.

Nicardipine infusion for hypotensive anesthesia during orthognathic surgery has protective effect on renal function.

PURPOSE: Hypotensive anesthesia may adversely affect renal function. The purpose of this study was to evaluate the renoprotective effect of nicardipine in patients undergoing orthognathic surgery under hypotensive anesthesia. MATERIALS AND METHODS: In this double-blinded randomized controlled study, healthy patients undergoing orthognathic surgery were enrolled to evaluate renal function during and after hypotensive anesthesia. The predictor variable was the agent, nicardipine vs remifentanil, used to maintain mean arterial pressure at 50 to 65 mm Hg. Primary outcome variables were renal function markers and secondary outcome variables were hemodynamic data, which were measured before hypotension, 2 hours after hypotension, 1 hour postoperatively (t3), and 24 hours postoperatively. Linear mixed model was used to analyze repeatedly measured data. RESULTS: Forty-six patients were randomly allocated to receive remifentanil (R group; n = 23) or nicardipine (N group; n = 23). The renal tubular function marker, urinary N-acetyl-1-ß-D-glucosaminidase (NAG), was lower at t3 in the N group than in the R group (P = .014). In the N group, fractional excretion of sodium was significantly higher at t3 compared with baseline (P < .0001). The 2 groups did not show any differences in estimated creatinine clearance and serum cystatin C. CONCLUSION: Subclinical and reversible renal dysfunction appears during hypotensive anesthesia in patients undergoing orthognathic surgery. Continuous infusion of nicardipine attenuated the increase in NAG, which is a marker of renal tubular injury, during hypotensive anesthesia with desflurane and remifentanil.

Renal excretion of fluoride after fluoride mouth rinses in children.

AIM: This study was conducted to determine if there was an increase in the urinary excretion of fluoride, after the use of fluoride mouth rinses in children. MATERIALS AND METHODS: The sample consisted of 58 children aged 5-8 years, randomly selected, residents in non-fluoridated water areas. Urine samples were collected prior to mouthwash and also 2 hours after use. The control sample, which received no treatment, consisted of 16 children of equivalent age and from the same community. Urinary excretion of fluoride was analysed by determining the pH, creatinine, F- ion and fluoride (mg)/creatinine (g) (F/Cr) ratio in urine. Results In the studied sample, the mean F/Cr ratio before fluoride mouth rinse was 0.26 mg/g and it rose to 1.58 mg/g 2 hours after mouth rinse. This difference of 1.33 mg/g was statistically highly significant (p<.001). In the control group no significant changes occurred. The average 2 hours afterward F/Cr ratios were 0.29 and 0.27 respectively (p=0.426). CONCLUSION: After the use of a fluoride mouthwash, in children, there is a statistically significant increase of fluoride ion in urine, which can be attributed to the application of this product.

Development of a reference interval for urinary ammonia-to-creatinine ratio in feline patients.

BACKGROUND: Disruption of acid-base homeostasis can lead to many clinical problems. Ammonia excretion by the kidneys is critical to maintaining acid-base homeostasis through bicarbonate production. Measurement of ammonia excretion may help determine if the kidneys are properly functioning in maintaining acid-base balance. Reference intervals are essential tools for clinical decision-making but do not currently exist for urinary ammonia-to-creatinine ratio (UACR) in feline patients. OBJECTIVE: This study aimed to generate a reference interval (RI) for UACR in healthy adult cats. METHODS: The study used samples from client-owned adult healthy cats that presented to the University of Florida Primary Care and Dentistry service (n = 92). Physical examination, serum biochemistry, urinalysis, urine ammonia, and creatinine concentrations were measured. Cats were excluded if there were significant abnormalities in their urinalysis or biochemistry panel. The RI for UACR was calculated according to the recommendation of the American Society for Veterinary Clinical Pathology. The UACR was evaluated for correlation with serum bicarbonate, weight, age, and sex. RESULTS: The RI for UACR was 3.4-20.7 with 90% confidence intervals for the lower and upper limits of (3.0-3.7) and (16.0-23.7), respectively. No significant correlation with age, sex, or weight was found. There was no discernable relationship between serum bicarbonate and UACR. CONCLUSIONS: Establishing an RI for UACR in healthy adult cats will allow further studies to determine if changes in UACR are observed during specific disease states.

Urine multi-index intelligent detection based on polymer/paper hybrid microfluidic biochip for hyperuricemia monitoring.

Hyperuricemia (HUA) has gradually become a public health burden as an independent risk factor for a variety of chronic diseases. Herein, a user-friendly point-of-care (POC) detection system (namely "Smart-HUA-Monitor") based on smartphone-assisted paper-based microfluidic is proposed for colorimetric quantification of HUA urinary markers, including uric acid (UA), creatinine (CR) and pH. The detection limits of UA and CR were 0.0178 and 0.5983 mM, respectively, and the sensitivity of pH were 0.1. The method was successfully validated in artificial urine samples and 100 clinical samples. Bland-Altman plots showed a high consistency between µPAD and the testing instruments (HITACHI 7600 Automatic Analyzer, URIT-500B Urine Analyzer and AU5800B automatic biochemical analyzer) in hospital. Smart-HUA-Monitor provides an accurate quantitative, rapid, low-cost and reliable tool for the monitoring and early diagnosis of HUA urine indicators.

Frequencies of chromosomal aberrations and related biochemical parameters in welders.

Stainless steel welders are exposed to heavy filler metals. We evaluated the concentration of these metals in whole blood and urine, and the relevant biochemical parameters in relation to the total chromosomal aberrations (CAs), chromatid-type (CTA-type, CTAs) and chromosome-type (CSA-type, CSAs), in 117 welders and control individuals. Statistically higher concentrations of the total Cr, Ni and Mn were observed in whole blood and urine of welders, and the concentrations were higher in welders who smoked. On the contrary, concentrations of urinary heavy metals Cr and Mn adjusted for creatinine were significantly higher in the control groups. A statistically higher frequency of total CAs was observed in the whole group of welders, and also in the non-smoking welders, as compared to controls. The frequency of total CAs significantly correlated with the concentration of Cr, Ni and Mn in whole blood (R=0.61, P˂0.0001, R=0.33, P˂0.0001 and R=0.66, P˂0.0001, respectively), with urinary concentrations of Ni and Mn (R=0.27, P=0.003 and R=0.28, P=0.003, respectively) and with urinary concentrations of Cr, Ni and Mn adjusted for creatinine (R=0.22, P=0.029, R=0.26, P=0.005 and R=0.20, P=0.030, respectively). Likewise, the frequency of CTA-types significantly correlated with the concentration of Cr and Mn in whole blood (R=0.31, P=0.0007 and R=0.34, P=0.0002). The frequency of CSA-types significantly correlated with concentrations of Cr, Ni and Mn in whole blood (R=0.43, P˂0.0001, R=0.38, P˂0.0001 and R=0.46, P˂0.0001, respectively). The statistically higher values of serum creatinine and total bilirubin were detected in all welders, as well as in smokers when compared to the corresponding controls. The exposure to heavy metals in welders increased the frequencies of CAs and altered the balance between urinary excretion of heavy metals and their possible accumulation.

Association between water consumption from polycarbonate containers and bisphenol A intake during harsh environmental conditions in summer.

With the exception of polycarbonate (PC) baby bottles, little attention has been paid to bisphenol A (BPA) intake from packaged water consumption (PC water dispensers), especially during summer weather conditions. We determined the magnitude and variability of urinary BPA concentrations during summer in 35 healthy individuals largely relying upon PC packaged water to satisfy their potable needs. We used liquid chromatography-tandem mass spectrometry to measure urinary BPA concentrations. A questionnaire was administered in July/August and a spot urine sample was collected on the same day and 7 days after the completion of the interview (without intervention). Linear regression was performed to assess the association of variables, such as water consumption from different sources, on urinary BPA levels for the average of the two urine samples. A significant positive association (p = 0.017) was observed between PC water consumption and urinary BPA levels in females, even after adjusting for covariates in a multivariate regression model. The geometric mean of daily BPA intake back-calculated from urinary BPA data was 118 ng · (kg bw)(-1) · day(-1), nearly double the average intake levels observed in biomonitoring studies worldwide. High urinary BPA levels were partially ascribed to summer's high PC water consumption and weather characteristics (high temperatures, >40 °C; very high UV index values, >8), which could be causing BPA leaching from PC. It is suggested that PC-based water consumption could serve as a proxy for urinary BPA, although the magnitude of its relative contribution to overall daily intake requires further investigation.

Effect of subchronic zinc toxicity on rat salivary glands and serum composition.

BACKGROUND: Zinc plays an important role in a wide variety of metabolic processes in animal systems. The role of zinc in preservative treatment, fungicidal action and medicine, and addition of supplementary zinc have increased the probability of zinc toxicity, specially the chronic type. It is known that the composition and quantity of saliva influence the oral health. Regarding people's exposure to zinc in routine life and the importance of saliva, our purpose was to investigate the effects of oral zinc intoxication on secretory function in rat salivary glands and also on serum composition. METHODS: In this study, there were five groups of female rats. Four groups received zinc acetate dehydrate through their drinking water. After 3 months of experiment, the chemical characteristics and flow rate of saliva and weight of salivary glands were determined. The effects of zinc on hematological and chemical factors of plasma were assessed too. RESULTS: Flow rate of submandibular glands was significantly lower in experimental groups and there were significant changes in Na(+), Ca(2+) and K(+) concentration both in saliva and in plasma. The serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, glucose levels in the plasma and urine creatinine levels were also altered in experimental groups in comparison with the control group. CONCLUSION: Our results show that zinc toxicity will affect the quantity and quality of saliva probably through changes in the various neurologic pathways to the salivary glands or effects on acinar cells of the salivary glands. Furthermore, our results showed that zinc toxicity will affect the liver and renal function.

Dental composite fillings and bisphenol A among children: a survey in South Korea.

AIMS: Bisphenol A (BPA)-based dental composites have commonly been used to fill dental cavities or seal pits and fissures on teeth. However, epidemiological evidence with regard to the BPA exposure from dental composites among children has rarely been reported. This study investigated whether there is a relationship between the BPA concentration in urine and the presence of composite restorations and sealants among South Korean children. METHODS: Oral examinations and urine sample analyses were conducted on a total of 495 children aged 8-9 years. We classified the participants into four groups by the number of resin composites and sealant surfaces (0, 1-5, 6-10 and 11+). RESULTS: BPA concentrations in urine were higher in children with 11 or more surfaces restored with sealants and resin composites than in those with zero restored surfaces, although no difference was seen in the group with 1-10 surfaces. After adjusting for gender and age, the urinary BPA concentration in children with 11 or more resin composite surfaces was 2.67 µg/g creatinine, which was higher than the concentration found in those with no filling surfaces (P < 0.01). CONCLUSIONS: Having many dental composite filling surfaces on teeth may increase the urinary BPA concentration in children.

Renal fluoride excretion in children following topical application of fluoride varnish.

AIM: To demonstrate that the application of dental fluoride varnishes in children increases urinary fluoride excretion. MATERIALS AND METHODS: From a randomly assembled group of 42 children aged between 5 and 8 years, residing in a community with non-fluoridated water, spot urinary samples were taken before the topical application of dental fluoride varnish and 2 hours afterwards. In an age-matched control group of 16 children from the same community, who received no treatment, samples were taken the same way. The urinary excretion of fluoride was analysed by determining fluoride ion (F-) level and fluoride/creatinine (F/Cr) ratio in the urine. RESULTS: In the study group, the average pre- and post-treatment F/Cr ratios were 0.42 and 1.38 mg/g, respectively (p < .001). No significant changes were observed in the control group, which received no treatment. The average 2 hours afterward F/Cr ratios were 0.29 and 0.27 respectively (p = 0.426). CONCLUSION: The topical application of dental fluoride varnish leads to a significant increase in urine F-, which is attributable to the application of the product.

[Health risk assessment of exposure to metals in the workers of the steel foundry and in the general population of Taranto (Italy)]. / Valutazione del rischio per la salute do esposizione a elementi metallici nei lavoratori del siderurgico e nella popolazione generale di Taranto (Italia).

OBJECTIVE: To study the urinary excretion of As, Cr, Mn, Co, Ni, Cu, Zn, Cd, Sn, Ba, Hg, Pb, Sb in workers at the Taranto integrated-cycle steel foundry and in subjects from the general population of Taranto, to assess the health risk posed by occupational exposure and environmental exposure, respectively, to these metals. MATERIALS AND METHODS: The study included 49 steel foundry workers (exposed), working in the minerals and agglomerates pools, steel processing plants 1 and 2 and maritime plants, and 50 subjects belonging to the general population of Taranto resident at various distances from the factory (controls), randomly selected from the exposed subjects and controls enrolled in previous research conducted in 2005. A questionnaire was administered to all participants, enquiring into general characteristics, lifestyle, diet, and any medical conditions. Informed written consent to take part in the study was obtained from all subjects before enrolment. The results of environmental monitoring performed in 2005 in the workers' sectors, consisting of determining As, Cr, Mn, Ni, Cu, Zn, Cd and Pb in the respirable dust, revealed by both samplers applied in fixed positions and personal samplers, were considered. Urine samples were obtained from all participants on a Friday, to determine As and Cr by AAS and all the other metal elements by a multielement technique with ICP-MS. Urinary creatinine was also determined to make any necessary adjustments. All urine analyses were performed in 2005 within one month of urine collection. RESULTS: In the respirable dust, As and Cd were always within the LOD, whereas Cr, Mn, Ni, Cu and Pb were 1-2 orders of magnitude below the respective TLV-TWA of the ACGIH. Mn was the only metal element that presented significantly higher urinary concentrations in exposed subjects as compared to controls, although the values in both groups were in any case within the Italian reference range. Co, Cu, Zn, Sn and Sb showed significantly higher urinary concentrations in controls than in the exposed subjects, while there were no differences in As, Cr, Cd, Ba, Hg and Pb between the two groups. Ni was within the LOD in the 60% of the subjects in the two groups. Multiple stepwise regression showed a dependence of Cr on age, of As on the number of days since the last meal of mollusks and crustaceans, of Zn on the consumption of mollusks, and of Cd and Pb on smoking expressed as the number of pack/year. DISCUSSION: The research did not reveal higher urinary excretion of the metal elements in the steelworkers than in the subjects from the general population of Taranto resident at different distances from the factory, except for Mn, that was anyway within the reference range. This allows us to consider that there is no relevant health risk posed by occupational exposure to metal elements in the steelworkers, nor by environmental exposure to the same elements in the residents of the city of Taranto. In particular, no pollution of the living environment by metal elements of industrial origin was demonstrated, whereas other non occupational factors seem to condition the intake of these metal elements.