Nephrolithiasis Associated with Nephrocalcinosis Is Primarily Composed of Carbonate Apatite.

INTRODUCTION: This study was designed to determine the mineral composition of calculi in nephrocalcinosis with nephrolithiasis, diagnose the underlying disease, and monitor the course of renal function in patients with nephrocalcinosis-nephrolithiasis. METHODS: Renal calculi extruded in a series of 8 patients with nephrocalcinosis were analysed using Fourier transmission infrared spectrometry. In 4 patients, next-generation sequencing using a nephrocalcinosis-nephrolithiasis panel was performed to determine the nature of the underlying disease. In addition, longitudinal analysis of renal function was performed in all patients. RESULTS: Seven patients revealed carbonate apatite as the sole constituent of renal calculi. One patient showed a mixed composition of dicalcium phosphate dihydrate/carbonate apatite at first analysis yet in subsequent episodes also had calculi composed of pure carbonate apatite. Further molecular analysis displayed distal renal tubular acidosis in 2 of 4 patients who consented to sequencing. No known genetic defect could be found in the other two cases. In line with prior reports, decline of renal function was dependent on underlying disease. Distal renal tubular acidosis revealed a progressive course of renal failure, whereas other causes showed stable renal function in long term analysis. CONCLUSION: Nephrocalcinosis with nephrolithiasis is a rare condition with heterogeneous aetiology. Yet mineral composition of renal calculi predominantly consisted of pure carbonate apatite. This uniform finding is similar to subcutaneous calcifications of various origins and might propose a general principle of tissue calcification. Progressive decline of renal function was found in distal renal tubular acidosis, whereas other conditions remained stable over time.

Evaluation of toothpastes for treating root carious lesions - a laboratory-based pilot study.

BACKGROUND: Root caries is preventable and can be arrested at any stage of disease development. The aim of this study was to investigate the potential mineral exchange and fluorapatite formation within artificial root carious lesions (ARCLs) using different toothpastes containing 5,000 ppm F, 1,450 ppm F or bioactive glass (BG) with 540 ppm F. MATERIALS AND METHODS: The crowns of each extracted sound tooth were removed. The remaining roots were divided into four parts (n = 12). Each sample was randomly allocated into one of four groups: Group 1 (Deionised water); Group 2 (BG with 540 ppm F); Group 3 (1,450 ppm F) and Group 4 (5,000 ppm F). ARCLs were developed using demineralisation solution (pH 4.8). The samples were then pH-cycled in 13 days using demineralisation solution (6 h) and remineralisation solution (pH 7) (16 h). Standard tooth brushing was carried out twice a day with the assigned toothpaste. X-ray Microtomography (XMT) was performed for each sample at baseline, following ARCL formation and after 13-day pH-cycling. Scanning Electron Microscope (SEM) and 19F Magic angle spinning nuclear magnetic resonance (19F-MAS-NMR) were also performed. RESULTS: XMT results showed that the highest mineral content increase (mean ± SD) was Group 4 (0.09 ± 0.05), whilst the mineral content decreased in Group 1 (-0.08 ± 0.06) after 13-day pH-cycling, however there was evidence of mineral loss within the subsurface for Groups 1, 3 and 4 (p < 0.05). SEM scans showed that mineral contents within the surface of dentine tubules were high in comparison to the subsurface in all toothpaste groups. There was evidence of dentine tubules being either partially or completely occluded in toothpaste groups. 19F-MAS-NMR showed peaks between - 103 and - 104ppm corresponding to fluorapatite formation in Groups 3 and 4. CONCLUSION: Within the limitation of this laboratory-based study, all toothpastes were potentially effective to increase the mineral density of artificial root caries on the surface, however there was evidence of mineral loss within the subsurface for Groups 1, 3 and 4.

Identifying spatial influence of urban elements on road-deposited sediment and the associated phosphorus by coupling Geodetector and Bayesian Networks.

Elevated particles and phosphorus washed from road-deposited sediment (RDS) are noteworthy causes of eutrophication in urban water bodies. Identifying how urban elements (e.g., dwellings, roads) spatially influence RDS and the associated phosphorus can help pinpoint the primary management areas for RDS pollution and therefore effectively mitigate this problem. This study investigated spatial influence of urban elements on RDS build-up load and phosphorus load in Hanyang district of Wuhan city in central China. Bayesian Networks (BNs), combined with geographical detector (Geodetector) and correlation analysis, were applied to quantify spatial association between kernel density of urban elements, RDS build-up load and phosphorus load in RDS. Results showed that (1) areas with higher density of factories related elements usually had elevated level of RDS build-up load, aluminum-bound phosphorus (Al-P), occluded phosphorus (Oc-P), organophosphorus (Or-P). Higher load of RDS associated iron-bound phosphorus (Fe-P) and apatite phosphorus (Ca-P) usually occurred where dwellings, catering, and entertainment related elements were concentrated. (2) Urban elements mainly showed positive correlation with RDS build-up load, Fe-P, Ca-P, De-P (detrital apatite phosphorus), while they chiefly showed negative correlation with Ex-P (exchangeable phosphorus), Al-P, Oc-P, and Or-P. Bus stations, dwellings, and factories related elements had relatively strong determinant power over spatial stratified heterogeneity of RDS and RDS-associated phosphorus. (3) Geodetector and correlation analysis could boost factors filtering and construction of network structures in the process of developing BNs models. The developed BNs resulted in sound prediction of <150 µm RDS build-up load and phosphorus load, given that the prediction accuracy of models ranged from 0.532 to 0.657. These findings demonstrate that urban elements are useful spatial predictors of RDS pollution, and coupling Geodetector and BNs is promising in RDS pollution prediction and supporting urban nonpoint source pollution management.

Bone fragment or bone powder? ATR-FTIR spectroscopy-based comparison of chemical composition and DNA preservation of bones after 10 years in a freezer.

Freezing bone samples to preserve their biomolecular properties for various analyses at a later time is a common practice. Storage temperature and freeze-thaw cycles are well-known factors affecting degradation of molecules in the bone, whereas less is known about the form in which the tissue is most stable. In general, as little intervention as possible is advised before storage. In the case of DNA analyses, homogenization of the bone shortly before DNA extraction is recommended. Because recent research on the DNA yield from frozen bone fragments and frozen bone powder indicates better DNA preservation in the latter, the aim of the study presented here was to investigate and compare the chemical composition of both types of samples (fragments versus powder) using ATR-FTIR spectroscopy. Pairs of bone fragments and bone powder originating from the same femur of 57 individuals from a Second World War mass grave, stored in a freezer at - 20 °C for 10 years, were analyzed. Prior to analysis, the stored fragments were ground into powder, whereas the stored powder was analyzed without any further preparation. Spectroscopic analysis was performed using ATR-FTIR spectroscopy. The spectra obtained were processed and analyzed to determine and compare the chemical composition of both types of samples. The results show that frozen powdered samples have significantly better-preserved organic matter and lower concentrations of B-type carbonates, but higher concentrations of A-type carbonates and stoichiometric apatite. In addition, there are more differences in the samples with a low DNA degradation index and less in the samples with a high DNA degradation index. Because the results are inconsistent with the current understanding of bone preservation, additional research into optimal preparation and long-term storage of bone samples is necessary.

A Potassium Based Fluorine Containing Bioactive Glass for Use as a Desensitizing Toothpaste.

Potassium releasing bioactive glasses (BAGs) may offer improved relief for dentine hypersensitivity compared to conventional sodium containing BAGs by releasing K+ ions for nerve desensitization and occluding dentinal tubules to prevent fluid flow within dentinal tubules. Potassium oxide was substituted for sodium oxide on a molar basis in a fluoride containing BAG used in toothpastes for treating dentine hypersensitivity. The BAG powders were then immersed in an artificial saliva at pH 7 and tris buffer and the pH rise and ion release behavior were characterized by ICP-OES and ISE. The potassium and sodium containing BAGs were characterized by XRD, DSC, FTIR and NMR. Both BAGs presented amorphous diffraction patterns and the glass transition temperature of the potassium glass was higher than that of the sodium glass. The 31P MAS-NMR spectra indicated a peak at 2.7 ppm corresponding to apatite and a small peak at -103 ppm indicated crystallization to fluorapatite. Both BAGs dissolved and formed apatite at similar rates, although the dissolution of the potassium glass was slightly slower and it released less fluoride as a result of partial nanocrystallization to fluorapatite upon quenching. The potassium release from the potassium ions could potentially result in nerve deactivation when used in toothpastes.

Multi-tissue stable carbon and nitrogen isotope models for dietary reconstruction: Evaluation using a southern African farming population.

OBJECTIVES: Multi-tissue stable isotope models to reconstruct past diets (Froehle, Kellner, & Schoeninger, 2012; Kellner & Schoeninger, 2007) have lacked data from a heavily C4 -dependent population. Using new data from southern African agriculturalists, published models are evaluated for accuracy in dietary reconstruction and applicability to isotopically diverse diets. Additionally, isotopic variation between tooth enamel and bone apatite, which are often treated as isotopically equivalent, is investigated. MATERIALS AND METHODS: δ13 Cbone apatite , δ13 Ctooth enamel , δ13 Ccollagen , and δ15 Ncollagen values for 51 adult southern African agriculturalists are presented. Bivariate (linear) and multivariate (cluster analysis, discriminant function analysis) models are recreated including these data, and the resulting dietary reconstructions evaluated against what we know of archaeological diets. RESULTS: Δ13 Ccollagen-enamel (5.67 ± 1.66‰) is significantly larger than Δ13 Ccollagen-bone apatite (4.77 ± 1.42‰) and are significantly different from each other (Mann Whitney U-Test, p = 0.0). δ13 Cbone apatite and δ13 Ctooth enamel were uncorrelated (R2 = 0.24). The agriculturalists consumed highly variable and heterogeneous diets, (mean δ13 Cbone apatite = -6.25 ± 2.49‰, δ13 Ctooth enamel = -2.88 ± 2.48‰, δ13 Ccollagen = -8.65 ± 2.16‰, δ15 Ncollagen = 10.05 ± 1.9‰). Multi- and bi-variate models under-estimate the probable contribution of C3 energy sources, and recreation of cluster analysis results in a significant reduction in the parsimony of the dietary clusters derived in Froehle et al., 2012. CONCLUSION: Bone apatite and tooth enamel are distinct biominerals, and their δ13 C values should not be treated as equivalent. Multiple tissue isotopes provide valuable insight into diet that cannot be achieved with single tissues, but current models are limited by the lack of isotopic diversity in the data on which they are based.

Papillary Ductal Plugging is a Mechanism for Early Stone Retention in Brushite Stone Disease.

PURPOSE: Mechanisms of early stone retention in the kidney are under studied and poorly understood. To date attachment via Randall's plaque is the only widely accepted theory in this regard, which is best described in idiopathic calcium oxalate stone formers. Brushite stone formers are known to have distinct papillary morphology relative to calcium oxalate stone formers. As such we sought to determine whether stone attachment mechanisms in such patients may be similarly unique. MATERIALS AND METHODS: Patients undergoing percutaneous and or ureteroscopic procedures for stone removal consented to endoscopic renal papillary examination and individual stone collection. Each removed stone was processed using micro computerized tomography to assess the 3-dimensional microstructure and the minerals contained, and search for common structural features indicative of novel mechanisms of early growth and attachment to renal tissue. RESULTS: A total of 25 intact brushite stones were removed from 8 patients and analyzed. Video confirmed attachment of 13 of the 25 stones with the remainder believed to have been accidently dislodged during the procedure. Microscopic examination by light and computerized tomography failed to show evidence of Randall's plaque associated with any stone containing brushite. Conversely each brushite stone demonstrated microstructural evidence of having grown attached to a ductal plug formed of apatite. CONCLUSIONS: Three-dimensional analysis of small brushite stones suggests overgrowth on ductal apatite plugs as a mechanism of early stone growth and retention. Such findings represent what is to our knowledge the initial supporting evidence for a novel mechanism of stone formation which has previously been hypothesized but never verified.

Dietary inferences through stable isotope analysis at the Neolithic and Bronze Age in the southern Caucasus (sixth to first millenium BC, Azerbaijan): From environmental adaptation to social impacts.

OBJECTIVES: Subsistence strategies are of great interest for understanding how prehistoric societies adapted to their environment. This is particularly the case for the southern Caucasus where relationships have been shown with the northern Caucasus and Mesopotamia since the Neolithic and where societies are alternately described as sedentary and mobile. This article aims, for the first time, to characterize human diets and their evolution using biochemical markers, from the Neolithic to the Bronze Age (sixth-first millenium BC), at Mentesh Tepe, a site in the middle Kura valley in Azerbaijan. MATERIALS AND METHODS: The data set belongs to 40 humans, 32 domestic and wild animals, and 42 charred seeds discovered in situ and perfectly dated. Stable isotope analyses were performed, including (a) δ13 Cco and δ15 N for animal and human bone collagens and for seeds, and (b) δ13 Cap for human bone apatite. RESULTS: Almost all the data (25/31) suggest an increased contribution of cereals, lentils, and freshwater fish during the Neolithic, whereas afterwards, until the Late Bronze Age, all individuals consumed more animal proteins from their livestock. None of the biological criteria (age at death and sex) and burial types (mass/single graves) were found to be related to a specific diet over time. Comparisons with other isotopic data from contemporary sites in Georgia argue in favor of a wide variety of dietary sources in the vicinity of the Kura valley and for highly mobile populations. Clear evidence of millet consumption has only been found for the Late Bronze Age.

Estimated depth of apatite and collagen degradation in human dentine by sequential exposure to sodium hypochlorite and EDTA: a quantitative FTIR study.

AIM: To characterize chemical degradation of the principal constituents of dentine after exposure to NaOCl and EDTA using Infrared Spectroscopy (ATR-FTIR). METHODOLOGY: Ground dentine particles, from extracted permanent human molars, were passed through sieves of 38 to 1 000 µm to provide six size ranges. Portions (250 mg) of each size range were reacted with 5 mL of 2.5% NaOCl for 2-10 min; or 17% EDTA for 5-1440 min. Powders larger than 75 µm were also sequentially exposed to NaOCl/EDTA/NaOCl each for 10 min. All experiments were repeated five times. Reacted and unreacted powders were washed and dried. Particles larger than 75 µm were then reground. FTIR spectra of unground and reground reacted particles enabled assessment of particle surface versus bulk chemistry, respectively, plus estimation of reaction depth. Changes in the ratio of the 1 640 cm-1 collagen: 1 010 cm-1 phosphate peak height or its inverse were obtained. These were used to estimate surface and bulk fraction reacted and thus depth to which collagen or phosphate was reduced following immersion in NaOCl or EDTA, respectively. The data were analysed descriptively. RESULTS: Surface collagen fraction declined by ~40% within 2 min of NaOCl exposure, and plateaued at ~60% between 6-10 min. Bulk spectra showed average depth of collagen loss at 10 min was 16 ± 13 µm. Ten minute EDTA exposure caused ~60% loss of surface phosphate. Average depth of phosphate loss was 19 ± 12 µm and 89 ± 43 µm after 10 and 1 440 min EDTA immersion, respectively. Sequential NaOCl/EDTA immersion yielded a 62 ± 28 µm thick phosphate-depleted surface. Sequential NaOCl/EDTA/NaOCl treatment resulted in approximately 85 µm of collagen loss. CONCLUSIONS: Data revealed the sequential depletion of collagen by NaOCl and apatite by EDTA in dentine, simultaneously exposing the other moieties. Alternate exposure to NaOCl and EDTA therefore enhances the depth of erosion.

[Etiological factors for calculus-associated seminal vesiculitis: Analysis of calculus composition in 6 cases].

OBJECTIVE: To explore the etiological factors for calculus-associated seminal vesiculitis by analyzing the composition of seminal vesicle calculus samples. METHODS: This retrospective study included 6 cases of recurrent hematospermia diagnosed with seminal vesicle calculus by non-contrast pelvic CT. The patients were aged 28 to 69 years, with persistent or recurrent hematospermia for 3 months to 6 years, and 5 of them with a history of acute urethritis. All the patients underwent seminal vesiculoscopy, which confirmed calculus-associated seminal vesiculitis. The calculus samples were obtained with a spiral dislodge and their composition was determined with a second-generation infrared calculus composition analyzer. The patients were followed up for 2 to 12 weeks postoperatively, during which non-contrast pelvic CT was employed for observation of recurrent calculus in the reproductive tract. RESULTS: Pelvic CT scanning indicated recurrence of seminal vesicle calculus in 3 cases at 12 weeks postoperatively, of which, 2 were accompanied with recurrent hematospermia, both observed at 4 weeks after operation. As for the composition of the calculus, the infrared calculus composition analyzer revealed struvite (magnesium ammonium phosphate hexahydrate) in 5 cases and a mixture of calcium oxalate dihydrate, calcium oxalate monohydrate, and carbonate apatite in the other one. CONCLUSIONS: Seminal vesicle calculi are most commonly composed of struvite, and infection is the main etiological factor for calculus-associated seminal vesiculitis.

Mineral Depositions of Calcifying Skin Disorders are Predominantly Composed of Carbonate Apatite.

Subcutaneous calcifications can lead to complications, including pain, inflammation, ulceration and immobilization. Studies on the pathophysiology of mineral compositions and effective treatment modalities are limited. We therefore studied 14 patients with subcutaneous calcifications. Mineral material was collected and analysed by Fourier transform infrared spectrometry. Blood analyses were run to evaluate systemic alterations of mineral metabolism. Carbonate apatite (CAP) was found to be the single constituent in the majority of patients (n = 9, 64.3%), 3 cases (21.4%) had a composition of CAP and calcium oxalate dihydrate and one case had a combination of CAP and magnesium ammonium phosphate, whereas CAP was the major component in all 4 cases. Only one case showed predominantly calcium oxalate. Thus, CAP was found to be the only or predominant component in most cases of subcutaneous calcifications. Chemical analyses of the mineral compositions may aid in the development of new treatment regimes to improve the solubility of mineral components and to decrease extraosseous calcifications.

From solvent-free microspheres to bioactive gradient scaffolds.

A solvent-free microsphere sintering technique was developed to fabricate scaffolds with pore size gradient for tissue engineering applications. Poly(D,L-Lactide) microspheres were fabricated through an emulsification method where TiO2 nanoparticles were employed both as particulate emulsifier in the preparation procedure and as surface modification agent to improve bioactivity of the scaffolds. A fine-tunable pore size gradient was achieved with a pore volume of 30±2.6%. SEM, EDX, XRD and FTIR analyses all confirmed the formation of bone-like apatite at the 14th day of immersion in Simulated Body Fluid (SBF) implying the ability of our scaffolds to bond to living bone tissue. In vitro examination of the scaffolds showed progressive activity of the osteoblasts on the scaffold with evidence of increase in its mineral content. The bioactive scaffold developed in this study has the potential to be used as a suitable biomaterial for bone tissue engineering and hard tissue regeneration.

High-precision (34) S/(32) S measurements in vertebrate bioapatites using purge-and-trap elemental analyser/isotope ratio mass spectrometry technology.

RATIONALE: In ecological studies, the sulfur isotope compositions (δ(34) S values) of soft tissues (e.g. hair, skin, nail, muscle, collagen) allow the determination of both past and present-day living environments of organisms. However, technical limitations have so far prevented reliable sulfur isotope analyses of minerals having low sulfur content, such as bioapatite, which is the crystalline component of skeletal tissues. The development of 'purge-and-trap' technology in elemental analysers recently demonstrated new possibilities to solve some of those technical difficulties. METHODS: We have used a VarioPYROcube elemental analyser (EA) equipped with 'purge-and-trap' technology, interfaced in continuous flow mode to an Isoprime 100 isotope ratio mass spectrometer, to measure the sulfur isotope compositions of bioapatite samples. We first characterised a working calibrated material of chemical composition close to those of our samples, the low-S bearing phosphorite BCR32, against the two δ(34) SV-CDT reference-calibrated materials, NBS-127 and IAEA-SO-5. We have confirmed a δ(34) SV-CDT value of +18.4‰ (1σ = 0.5; n = 18) in agreement with the previously published value. Using BCR32 as a compositional and isotopic reference material, we have then measured the δ(34) SV-CDT values of various bioapatite tissues (bone, dentine and enamel) from both modern and fossil vertebrates living in different environments (marine, freshwater and terrestrial). RESULTS: Our results demonstrate the capacity of this analytical setup to measure the δ(34) SV-CDT values of low-S bioapatite samples (0.14 to 1.19 wt%) with a good analytical precision (1σ = 0.5; n = 14). Our results also show that the δ(34) SV-CDT values of modern and fossil vertebrate bioapatites allow discrimination between marine environments and freshwater or terrestrial ones. CONCLUSIONS: Sulfur isotope analysis of bioapatite has great potential to track the living environment of extinct vertebrates for which only fossilised bones or teeth have been preserved. Copyright © 2016 John Wiley & Sons, Ltd.

Ca L2,3-edge XANES and Sr K-edge EXAFS study of hydroxyapatite and fossil bone apatite.

Upon burial, the organic and inorganic components of hard tissues such as bone, teeth, and tusks are subjected to various alterations as a result of interactions with the chemical milieu of soil, groundwater, and presence of microorganisms. In this study, simulation of the Ca L 2,3-edge X-ray absorption near edge structure (XANES) spectrum of hydroxyapatite, using the CTM4XAS code, reveals that the different symmetry of the two nonequivalent Ca(1) and Ca(2) sites in the unit cell gives rise to specific spectral features. Moreover, Ca L 2,3-edge XANES spectroscopy is applied in order to assess variations in fossil bone apatite crystallinity due to heavy bacterial alteration and catastrophic mineral dissolution, compared to well-preserved fossil apatite, fresh bone, and geologic apatite reference samples. Fossilization-induced chemical alterations are investigated by means of Ca L 2,3-edge XANES and scanning electron microscopy (SEM) and are related to histological evaluation using optical microscopy images. Finally, the variations in the bonding environment of Sr and its preference for substitution in the Ca(1) or Ca(2) sites upon increasing the Sr/Ca ratio is assessed by Sr K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy.

[Composition of 359 kidney stones from the East region of Algeria]. / Détermination de la composition de 359 calculs du haut appareil urinaire collectés dans la région Est-algérien.

PURPOSE: Determine stones composition of the upper urinary tract in the eastern region of Algeria. METHODS: Our study focuses on a set of 359 stones of the upper urinary tract collected between January 2007 and December 2012 at hospitals in the eastern region of Algeria and analyzed by Fourier transform infrared spectroscopy. RESULTS: The male/female ratio was only 1.32. Calcium oxalate prevailed in 68.5% of stones and 49.3% of nuclei, mainly as whewellite (51.8% of stones and 37.9% of nuclei vs 16.7% and 11.4% respectively for weddellite). Carbapatite prevailed in 15% of stones and 29.8% of nuclei. The struvite, identified in 11.1% of calculi, prevailed in 3.9% of stones and 3.1% of nuclei. Among purines, uric acid prevailed with frequencies quite close to 8.9% and 7% respectively in the stone and in the nucleus while the ammonium urate prevailed in only 0.3% of stones and 3.3% of nuclei. The cystine frequency was 3.6% in both stone and nucleus. The frequency of stone with umbilication was 26.2%. Whewellite was the main component of umbilicated stones with Randall's plaque. CONCLUSION: Our results suggest that stones of the urinary tract in the Algerian east region resemble those observed in industrialized countries. Some features such as stones location, the whewellite prevalence, the frequencies of main components in both the stone and the nucleus as well as the formation of stones on renal papilla confirm this trend. LEVEL OF EVIDENCE: 4.

[Epidemiological study on urinary stones in the region of Fez and the risk of recurrence]. / Étude épidémiologique sur les calculs urinaires dans la région de Fès et sur le risque de récidive.

OBJECTIVE: In Morocco, few works on morpho-constitutional analysis of urinary calculi have been published, especially for patients in the region of Fez. This work aims to make a retrospective epidemiological study on the nature of urinary calculi with patients from the region of Fez and control the urine of the same patients after a period of three months to report on the risk of recurrence. METHOD AND PATIENTS: Urinary stones were collected mostly in the nephrology service and urology service at the Hassan II Hospital in Fez. These calculations after being dried for 24 hours at room temperature underwent a morphological analysis, followed by infrared spectroscopic analysis Fourier transform. After a period of about three months, morning urine of the same patients was analyzed by crystalluria to control the presence of crystals that reflect a risk of recurrence. RESULTS: In our series of 123 samples, the age of patients ranges from 2-79 years. The prevalence was higher for men with a sex ratio of 1.3. The results of the analysis calculations showed that 61% were formed of calcium oxalate and 15% of uric acid and 25% of stones were carbapatite, struvite, cystine… The study by crystalluria urine revealed the presence of the crystals in 69% of patients' nephrolithiasis. CONCLUSION: The results of our study are conformed to the series of results in other regions of Morocco regarding the predominance of calcium oxalate stones. The presence of crystals in the urine of 69% of patients may indicate other recurrences. LEVEL OF EVIDENCE: 4.

Effect of dynamic three-dimensional culture on osteogenic potential of human periodontal ligament-derived mesenchymal stem cells entrapped in alginate microbeads.

BACKGROUND AND OBJECTIVE: Bioreactors are devices that efficiently create an environment that enables cell cultures to grow in a three-dimensional (3D) context mimicking in vivo conditions. In this study, we investigate the effect of dynamic fluid flow on the osteogenic potential of human mesenchymal stem cells obtained from periodontal ligament and entrapped in alginate microbeads. MATERIAL AND METHODS: After proper immunophenotyping, cells were encapsulated in barium alginate, cultured in 3D static or 3D dynamic conditions represented by a bioreactor system. Calcein-AM/propidium iodide staining was used to assess cellular viability. Quantitative real-time polymerase chain reaction was used to analyze the expression of osteogenic markers (Runx2 and COL1). Alizarin Red S staining and the Fourier transform infrared spectroscopy were used to assess mineral matrix deposition. RESULTS: Optimal encapsulation procedure, in terms of polymer pumping rate, distance from droplet generator to the gelling bath and atomizing airflow was assessed. Cell viability was not affected by encapsulation in alginate microbeads. Bioreactor cell exposure was effective in anticipating osteogenic differentiation and improving mineral matrix deposition. CONCLUSION: For the first time human mesenchymal stem cells obtained from periodontal ligaments encapsulated in alginate microbeads were cultured in a bioreactor system. This combination could represent a promising strategy to create a cell-based smart system with enhanced osteogenic potential useful for many different dental applications.

Renal and prostate stones composition in alkaptonuria: a case report.

Alkaptonuria is a genetic disorder characterized by an accumulation of homogentisic acid due to an enzymatic defect of homogentisate 1,2 dioxygenase. The homogentisic acid is excreted exclusively by both glomerular filtration and tubular secretion leading to the renal parenchyma being exposed to high concentrations of homogentisic acid. The alkaptonuric patients are at higher risk of renal stones (and of prostate stones for males), usually in the later stages of the disease. We describe the case of a 51-year-old man whose renal and prostate stones were analyzed by X-ray diffraction and infrared spectroscopy, respectively. We review the cases of alkaptonuria (AKU) patients reported in the literature for whom the composition of kidney or prostate stones was assessed with physical or chemical techniques. In this paper, we also discuss the advantages and drawbacks of the different methodologies.

Diet and gender in the Tiwanaku colonies: Stable isotope analysis of human bone collagen and apatite from Moquegua, Peru.

OBJECTIVES: Gender and other facets of social identity play important roles in the organization of complex societies. This study reconstructs dietary practices within the Middle Horizon (AD 500-1000) Tiwanaku colonies in southern Peru to increase our knowledge of gendered patterns of consumption within this early expansive state. METHODS: We use stable isotope analysis of 43 human bone samples representing 14 females, 20 males, 8 juveniles, and 1 indeterminate individual recovered from burial excavations at the sites of Rio Muerto and Omo in the Moquegua Valley. Data are contextualized by comparisons with previously published Tiwanaku isotope data from the period. RESULTS: Our results find mean values of δ(13) Capatite = -7.3 ± 1.6% (N = 36, 1SD), δ(13) Ccollagen = -12.3 ± 1.5% (N = 43, 1SD), and δ(15) Ncollagen = 8.4 ± 1.6% (N = 43, 1SD). Between the sexes, Mann-Whitney U tests demonstrate significant differences in δ(13) Ccollagen (U = 74, P = 0.021), but no differences in δ(13) Capatite (U = 58, P = 0.095) or δ(15) Ncollagen (U = 116, P = 0.755) values. CONCLUSIONS: These data indicate relatively high C4 plant consumption among the Tiwanaku colonies, and support paleobotanical and archaeological evidence that maize (Zea mays) was the staple crop. Dietary values are similar overall between the sexes, but significantly higher δ(13) Ccollagen values in males is consistent with a model of gendered norms of consumption similar to that of the later Inca (AD 1438-1533), where males consumed more maize than females, often in the form of beer (chicha). Results provide new insights on social dynamics within the Tiwanaku colonies and suggest the increased importance maize consumption for males during the Tiwanaku expansion.

Dark-field transmission electron microscopy of cortical bone reveals details of extrafibrillar crystals.

In a previous study we showed that most of the mineral in bone is present in the form of "mineral structures", 5-6nm-thick, elongated plates which surround and are oriented parallel to collagen fibrils. Using dark-field transmission electron microscopy, we viewed mineral structures in ion-milled sections of cortical human bone cut parallel to the collagen fibrils. Within the mineral structures we observe single crystals of apatite averaging 5.8±2.7nm in width and 28±19nm in length, their long axes oriented parallel to the fibril axis. Some appear to be composite, co-aligned crystals as thin as 2nm. From their similarity to TEM images of crystals liberated from deproteinated bone we infer that we are viewing sections through platy crystals of apatite that are assembled together to form the mineral structures.