Composition and distribution of elements and ultrastructural topography of a human cardiac calculus

Strontium isotope ratios in kidney stones reveal the environmental implications for humans in Beijing, China

Kidney stones are a common disease that threatens human health on a global scale and are closely related to the contemporary environment. The strontium isotope ratio (⁸⁷Sr/⁸⁶Sr) has been widely used to trace the migration of ancient humans through bones and teeth, which recorded their bioavailable Sr from the environment. However, no ⁸⁷Sr/⁸⁶Sr data for kidney stones have been reported. Therefore, this study explored the Sr content of kidney stones and reported their ⁸⁷Sr/⁸⁶Sr data for the first time to reflect the environmental implications for humans; 66 calcium oxalate kidney stones collected in Beijing were measured for calcium (Ca), magnesium (Mg) and strontium (Sr) content to explore Sr distribution behavior in kidney stones, and 17 samples were tested for strontium isotopes. Ca and Mg had a joint effect on the Sr content of kidney stones, with magnesium having a stronger effect, whereas ⁸⁷Sr/⁸⁶Sr values were unaffected by these elements. The ⁸⁷Sr/⁸⁶Sr values of kidney stones ranged from 0.709662 to 0.710990, within the range of environmental soil and water in Beijing. Drinking water and surface soils (representing food sources) mainly contributed to the bioavailable Sr of kidney stones, while sea spray and dust storm did not. This study is the first to report ⁸⁷Sr/⁸⁶Sr values for kidney stones. Evidence of Sr isotope ratios in kidney stones reveals environmental implications for humans and bioavailable Sr sources, demonstrating a great potential of Sr isotope ratios at the intersection of life and environmental sciences.

Composition and spatial distribution of elements and isotopes of a giant human bladder stone and environmental implications

The composition and spatial distribution of minerals, trace elements, as well as carbon and nitrogen isotopes from the outer crust to inner nucleus of a 20-year old giant human bladder stone comprising thirteen layers were intensively investigated. Calcium oxalate monohydrate (COM) was found to concentrate in the inner and middle layers, struvite was concentrated in middle and outer layers, and fluorapatite occurred in almost all layers. The spatial distribution of minerals has the potential to provide preliminary knowledge regarding the long-term urine composition, or even the physiological condition of the patient. The stable carbon isotope ratio (δ¹³C) and stable nitrogen isotope ratio (δ¹⁵N) were measured in each layer and significant correlation was found between δ¹³C with calcium oxalate monohydrate content and between δ¹⁵N and struvite content. Nearly constant values of -23.2‰ and 7.1‰ for δ¹³C and δ¹⁵N, respectively, were found in the organic components of the stone. Both isotope ratios indicate a long-term fixed diet consisting mainly of C3 plants, such as rice and wheat, for the 20-year time period of the stone formation. In addition, eighteen elements (Ca, P, Mg, K, Na, Al, Fe, Zn, Pb, Cu, Sr, Ba, Ti, V, Cr, Ni, Mn and Co) were measured in all the layers. The trace elements Al, Fe, Cu, Zn, Pb, Sr, Ba and Ti showed a similar spatial distribution pattern from the outer crust to the inner core. Although there were complex correlations between elements and minerals, Factor Analysis suggests that the occurrence of these elements in stones may be mainly the result of environmental exposure to metals during the formation of the stone, indicating that urinary stones may serve as potential long-term biomonitors. In particular, Ni and Cr showed a distinct distribution pattern in the stone, which may relate to human metabolic activities.

Spectral and morphological classification of different chronic and acute Taiwanese gallstones via FTIR, SEM and ESEM-EDX microanalyses

BACKGROUND

Gallstone disease is one of the leading upper gastrointestinal surgical problems in different countries.

AIMS

To analyze the chronic gallstones and acute gallbladder sludge retrieved from 36 Taiwanese patients.

METHODS

FTIR microspectroscopy was used to classify the types of gallstones, and an ESEM-EDX microanalysis was first applied to determine the microstructural features and elemental compositions of the various gallstones. Bacteria presented on the surface of gallstones were also detected by SEM.

RESULTS

Four types of gallstones were obtained from these 36 Taiwanese patients: calcium bilirubinate (CaBR) stones (30.6%), cholesterol stones (19.4%), mixed stones including 6 subtypes (47.2%), and acute gallbladder sludge (2.8%) made of CaBR and protein/insoluble biomaterials. Bacteria imprints and bacterial discharges or bacterial biofilms were also found on the surface of gallstones and acute sludge under a SEM observation. ESEM-EDX results revealed that calcium was found to be the main constituent of all of the types of stones except cholesterol stones, and aluminum was also presented in most of the stones and sludge samples. Chloride was only detected in the acute gallbladder sludge.

CONCLUSION

FTIR spectra, morphological features, and elemental compositions of the acute gallbladder sludge were different from those of the chronic gallstones.

Dual-Energy Computed Tomography Gemstone Spectral Imaging: A Novel Technique to Determine Human Cardiac Calculus Composition

OBJECTIVE

Understanding the chemical composition of any calculus in different human organs is essential for choosing the best treatment strategy for patients. The purpose of this study was to assess the capability of determining the chemical composition of a human cardiac calculus using gemstone spectral imaging (GSI) mode on a single-source dual-energy computed tomography (DECT) in vitro.

METHODS

The cardiac calculus was directly scanned on the Discovery CT750 HD FREEdom Edition using GSI mode, in vitro. A portable fiber-optic Raman spectroscopy was also applied to verify the quantitative accuracy of the DECT measurements.

RESULTS

The results of spectral DECT measurements indicate that effective Z values in 3 designated positions located in this calculus were 15.02 to 15.47, which are close to values of 15.74 to 15.86, corresponding to the effective Z values of calcium apatite and hydroxyapatite. The Raman spectral data were also reflected by the predominant Raman peak at 960 cm for hydroxyapatite and the minor peak at 875 cm for calcium apatite.

CONCLUSIONS

A potential single-source DECT with GSI mode was first used to examine the morphological characteristics and chemical compositions of a giant human cardiac calculus, in vitro. The CT results were consistent with the Raman spectral data, suggesting that spectral CT imaging techniques could be accurately used to diagnose and characterize the compositional materials in the cardiac calculus.