Urinary stones as a novel matrix for human biomonitoring of toxic and essential elements.

Monitoring of body burden of toxic elements is usually based on analysis of concentration of particular elements in blood, urine and/or hair. Analysis of these matrices, however, predominantly reflects short- or medium-term exposure to trace elements or pollutants. In this work, urinary stones were investigated as a matrix for monitoring long-term exposure to toxic and essential elements. A total of 431 samples of urinary calculi were subjected to mineralogical and elemental analysis by infrared spectroscopy and inductively coupled plasma mass spectrometry. The effect of mineralogical composition of the stones and other parameters such as sex, age and geographical location on contents of trace and minor elements is presented. Our results demonstrate the applicability of such approach and confirm that the analysis of urinary calculi can be helpful in providing complementary information on human exposure to trace metals and their excretion. Analysis of whewellite stones (calcium oxalate monohydrate) with content of phosphorus <0.6 % has been proved to be a promising tool for biomonitoring of trace and minor elements.

Identification of new endocrine disruptive transthyretin ligands in polluted waters using pull-down assay coupled to non-target mass spectrometry.

Surface and treated wastewater are contaminated with highly complex mixtures of micropollutants, which may cause numerous adverse effects, often mediated by endocrine disruption. However, there is limited knowledge regarding some important modes of action, such as interference with thyroid hormone (TH) regulation, and the compounds driving these effects. This study describes an effective approach for the identification of compounds with the potential to bind to transthyretin (TTR; protein distributing TH to target tissues), based on their specific separation in a pull-down assay followed by non-target analysis (NTA). The method was optimized with known TTR ligands and applied to complex water samples. The specific separation of TTR ligands provided a substantial reduction of chromatographic features from the original samples. The applied NTA workflow resulted in the identification of 34 structures. Twelve compounds with available standards were quantified in the original extracts and their TH-displacement potency was confirmed. Eleven compounds were discovered as TTR binders for the first time and linear alkylbenzene sulfonates (LAS) were highlighted as contaminants of concern. Pull-down assay combined with NTA proved to be a well-functioning approach for the identification of unknown bioactive compounds in complex mixtures with great application potential across various biological targets and environmental compartments.

Association of minor and trace elements with mineralogical constituents of urinary stones: a hard nut to crack in existing studies of urolithiasis.

The role of metals in urinary stone formation has already been studied in several publications. Moreover, urinary calculi can also be used for assessing exposure of humans to minor and trace elements in addition to other biological matrices, for example, blood, urine, or hair. However, using urinary calculi for biomonitoring of trace elements is limited by the association of elements with certain types of minerals. In this work, 614 samples of urinary calculi were subjected to mineralogical and elemental analysis. Inductively coupled plasma mass spectrometry and thermo-oxidation cold vapor atomic absorption spectrometry were used for the determination of major, minor, and trace elements. Infrared spectroscopy was used for mineralogical analysis, and additionally, it was also employed in the calculation of mineralogical composition, based on quantification of major elements and stoichiometry. Results demonstrate the applicability of such an approach in investigating associations of minor and trace elements with mineralogical constituents of stones, especially in low concentrations, where traditional methods of mineralogical analysis are not capable of quantifying mineral content reliably. The main result of this study is the confirmation of association of several elements with struvite (K, Rb) and with calcium phosphate minerals, here calculated as hydroxylapatite (Na, Zn, Sr, Ba, Pb). Phosphates were proved as the most important metal-bearing minerals in urinary calculi. Moreover, a significantly different content was also observed for Fe, Zr, Mo, Cu, Cd, Se, Sn, and Hg in investigated groups of minerals. Examination of such associations is essential, and critical analysis of mineral constituents should precede any comparison of element content among various groups of samples.

First data on uranium uptake in three nototheniid fishes from Antarctica (James Ross Island).

Recent studies have confirmed historic atmospheric deposition of uranium in Antarctica, with a steep and significant increase in levels deposited since the 1980s in Antarctic Peninsula ice core samples. To date, however, there has been little or no attention paid to uranium in the Antarctic food web. Here, we present results for uranium content in scales of three common nototheniid species (Trematomus bernacchii, Gobionotothen gibberifrons, Notothenia coriiceps) from coastal waters off James Ross Island (Antarctic Peninsula). While mean total uranium levels (mean ±â€¯SD) were low and similar between species (N. coriiceps 0.08 µg g-1 ± 0.01, T. bernacchii 0.17 µg g-1 ± 0.10; G. gibberifrons 0.11 µg g-1 ± 0.04), linear regressions against standard length indicated bioaccumulation in T. bernacchii (ANOVA, F = 7.8349, P = 0.0076). We suggest this may be the result of dietary specialisation on prey with calcareous shells that accumulate uranium. To the best of our knowledge, this paper provides the first quantitative baseline data on uranium levels in coastal Antarctic nototheniids. While the low levels recorded are unlikely to represent a threat within the food chain, we suggest that further long-term trophic studies (including stable isotope analysis) are needed, recognising that the feeding ecology of individual species (and even individuals) can have a strong effect on overall trends.

Prediction of percent body fat in adult males using dual energy x-ray absorptiometry, skinfolds, and hydrostatic weighing.

The purpose of this study was to compare the prediction of percent body fat (%FAT) by dual energy x-ray absorptiometry (DXA), skinfolds (SF), and hydrostatic weighing (HW) in adult males. Subjects were 35 adult male Caucasians (mean +/- SD; age: 39.1 +/- 14.0 yr, height: 180.6 +/- 5.3 cm, weight: 81.0 +/- 11.1 kg). %FAT, determined by HW with residual volume determined via O2 dilution, served as the criterion. DXA %FAT was determined by the Norland XR-26 (XR-26) bone densitometer and by the SF equations of Jackson and Pollock (JP) (1978), and Lohman (LOH) (1981). Criterion referenced validation included analyzing mean (+/- SD) %FAT values using a one-way ANOVA for significance, comparison of mean differences (MD), correlations (r), standard error of estimates (SEE), and total errors (TE). Significant differences were found between means of each method. The r (0.91) and SEE (3.0 %FAT) for DXA compare favorably with the established SF methods of JP and LOH for predicting %FAT; however, DXA demonstrated the largest MD (3.9 %FAT) and TE (5.2 %FAT). Regression analysis yields HW = 0.79* DXA + 0.56. The results do not support earlier research that found no significant difference between HW and DXA %FAT in males. The study suggests the density of the fat-free body (DFFB) is not constant, and that the variation in bone mineral content affects the DFFB, which contributes to the differences between DXA and HW %FAT. We recommend further research to identify inconsistencies between manufacturers of DXA equipment in prediction of %FAT in males.

A comparison of methods to predict minimal weight in high school wrestlers.

The purpose of this study was to compare the accuracy of body fat determinations and subsequent calculation of minimal weight (MW) by dual energy x-ray absorptiometry (DEXA), bioelectrical impedance (BIA), near-infrared photospectometry (NIR), and anthropometry (LOHMAN). Necessitated by mandatory state minimal weight testing, the methods were cross-validated on 95 Wisconsin high school wrestlers (mean +/- SD; age: 15.1 +/- 1.2 yr, height: 170.4 +/- 7.1 cm, weight: 63.4 +/- 9.8 kg). MW, defined as fat-free body/0.93, determined by hydrostatic weighing (HW) and residual volume via O2 dilution, served as the criterion. The validity of the four selected MW predictions were evaluated against HW by examining mean differences (MD), standard deviation differences (SDD), correlations (r), standard error of estimate (SEE), and total errors (TE). Statistically significant differences were shown between the methods and the criterion by t-tests; however, these were clinically small in Lohman (0.6 kg) and BIA (0.9 kg). TE ranged from 2.25 kg (Lohman) to 6.03 kg (NIR). The results indicated that Lohman skinfold equation provided the most accurate prediction of MW, demonstrating the highest correlation (0.972), lowest MD (0.6 kg), lowest SEE (2.12 kg), and lowest TE (2.25 kg) of the methods evaluated.

Cross-validation of methods to predict body fat in African-American and Caucasian collegiate football players.

Eight skinfold (SF) equations and bioelectrical impedance analysis (BIA) were cross-validated in 71 Division IA college football players. Criterion percent body fat (%FAT) was determined by hydrostatic weighing (HW) and computed from body density (BD) for African Americans (n = 28) and Caucasians (n = 43). Results were analyzed by method, with position and race effects examined simultaneously using a two-way ANOVA. Analysis included computation of mean difference (MD), correlation (r), standard error of estimate (SEE), and total error (TE). Skinfolds had MDs ranging from -1.8 to 2.9%, correlations from .85 to .93, SEEs from 2.3 to 3.2%, and TEs from 2.3 to 4.2%. Bioelectrical impedance analysis was significantly different from HW and yielded the highest MD (3.8%), lowest correlation (r = .78), highest SEE (3.9%), and highest TE (5.4%). The Jackson and Pollock (1978) SF equation provided the most valid prediction of HW-determined %FAT in a racially mixed sample of college football players, demonstrating the highest correlation, lowest SEE and TE, and an intercept and slope not significantly different than 0.0 and 1.0, respectively.

SLAP lesions: a retrospective multicenter study.

A retrospective analysis of 530 glenohumeral arthroscopies performed by three independent Belgian arthroscopists revealed the presence of 32 SLAP lesions, which represents an incidence of 6%. Since this is exactly the same percentage as found by Snyder et al., we report our data in this article. We classified 23 of the SLAP lesions using Snyder's classification, 7 needed the additional classification of Maffet et al., and 2 lesions were considered to be anatomic variations; 53% of the lesions were of type II. Concerning the mechanism of injury, we found comparable percentages of traction (22%) and compression (28%) injury as reported by Snyder, but also a high number (25%) of overhead sports activities as described by Andrews et al. Associated lesions were in close accordance with Snyder's data, but a relatively low incidence of rotator cuff injuries (10%) was present. Comparison of treatment regimens showed that the same percentage of lesions (34%) was fixed arthroscopically in both series. Only SLAP II, IV, and V lesions must be considered as unstable and in need of fixation. We confirm that patients' complaints and clinical symptoms are vague and inconsistent. Imaging, using computed tomographic arthrography or magnetic resonance, was performed in a minority of cases. Advantages and pitfalls of both techniques are discussed. Anatomic variations causing an extra-large sublabral hole are shown, and we warn about potential diagnostic and therapeutic errors in these cases.

Characteristics and performance of male citizen cross-country ski racers.

Forty-three male citizen or recreational cross-country (X-C) ski racers (aged 31 +/- 4.4 years) were tested to determine their weight (BW) and percent body fat (BF), maximal oxygen uptake (VO2max), quadriceps (Quad), hamstrings (Ham) and upper body (UBS) isokinetic strength (60 degrees, 180 degrees, 240 degrees/s), and Quad endurance. In addition, skiers filled out a questionnaire to determine their skiing experience and to see what other activities they participated in. All these variables were run through a stepwise regression procedure to see which characteristics best predicted performance in a 10 km X-C ski race. The relatively high VO2max of 56.6 ml O2/kg/min and low BF of 10.1% indicate this group to be a very fit subset of the general population. All the skiers were active in other sports on a year-round basis. Of the variables studied, UBS, VO2max, and Quad strength were all significant determinants of 10 km race performance, yielding a multiple R of 0.78. Quad endurance, Ham strength, BW, BF, and experience did not significantly contribute toward the prediction of performance. It is felt that a proper training program for the citizen X-C skier should strive to maximize upper body strength as well as one's aerobic capacity.