Biological Trace Element Research最新文献

Nalidixic acid (Nal) is a quinolone antibiotic with activity against Gram-negative bacteria and is used to treat urinary tract infections caused by microorganisms belonging to the genera Escherichia, Proteus, Shigella, Enterobacter, and Klebsiella. The complexation of this molecule with zinc and auxiliary ligands such as phenanthroline (Phen) and 2,2'-bipyridine (Bipy) could modify its pharmacological and pharmacokinetic properties. This work presents the synthesis and characterization of the ZnNal complex ([Zn(Nal)₂(H₂O)₂]·2MeOH). Its molecular structure in the solid state was determined by X-ray diffraction. The complex crystallizes in the monoclinic space group P2₁/n with Z = 2 molecules per unit cell. In the solid state, the nalidixic acid (Nal) molecule appears as its anionic form (Nal⁻), deprotonated in the carboxyl group. The complex is centrosymmetric, with the Zn(II) ion at the center of a slightly elongated octahedral geometry, equatorially coordinated to a bidentate nalidixate anion and axially to a water molecule. The study includes the evaluation of antimicrobial activity of the binary complex and its derivatives with phenanthroline (ZnNalPhen) and bipyridine (ZnNalBipy) against both ATCC strains and clinical isolates. Additionally, compound safety was assessed using the Artemia salina model. ZnNal preserves the antimicrobial potency of the free ligand while exhibiting attenuated toxicity in this model, suggesting a more favorable biocompatibility profile for potential therapeutic applications. Notably, ZnNalPhen was the only complex active against Candida strains, highlighting that coordination with 1,10-phenanthroline expanded the antimicrobial spectrum of the parent ligand Nal to include antifungal activity. Furthermore, both ternary complexes showed an improved safety profile compared to Nal alone. Besides, zinc(II) complexes can be efficiently transported by albumin, which is a key factor in their potential therapeutic application.

Iron is an essential micronutrient that influences both the nutritional value of bivalves and their cellular iron homeostasis. However, the molecular mechanisms underlying interspecific differences in iron accumulation among economically important bivalves remain unclear. Ferritin (FER), a highly conserved iron-storage protein, plays a central role in iron regulation, yet comparative studies integrating sequence, expression, and functional analysis across multiple bivalve species are still limited. To address this, we designed a multi-level comparative approach that integrates tissue iron measurements, sequence analyses, expression profiling, and in vitro recombinant-protein functional assays-offering a broader comparative assessment than previous single-species or single-method studies. Using this framework, we evaluated tissue iron content and FER expression characteristics in five commercially important bivalve species: Sinonovacula constricta, Meretrix meretrix, Crassostrea gigas, Ruditapes philippinarum, and Tegillarca granosa. Iron levels, measured by ICP-MS and colorimetric assays, were highest in S. constricta (approximately 2.5-fold higher than C. gigas) and lowest in C. gigas. Bioinformatic analyses, including sequence conservation, motif prediction, and structural modeling using AlphaFold, showed high conservation of FER proteins across the five species. FER mRNA expression quantified by qRT-PCR partially corresponded to tissue iron content, with the strongest agreement observed in S. constricta, which showed approximately 3-fold higher FER expression than C. gigas. Recombinant FER proteins expressed in Escherichia coli exhibited Fe²⁺-responsive migration patterns and iron enrichment capacities, with FER from S. constricta showing strong iron enrichment activity, approximately 2.2-fold higher than that of C. gigas. Collectively, these findings indicate that FER may be associated with interspecific variation in iron accumulation among bivalves. The high tissue iron content, elevated FER expression, and strong recombinant FER iron enrichment capacity observed in S. constricta suggest that FER may contribute to iron storage in this species. However, the inconsistent patterns observed in T. granosa and R. philippinarum indicate that iron accumulation in bivalves is likely regulated by multiple FER-dependent and FER-independent mechanisms.

Hair elemental homeostasis has emerged as a potential source of information for understanding the interactions between environmental exposure, nutrition, and neurodevelopment in autism spectrum disorder (ASD). This study characterized the multielement hair profile of Uruguayan children with ASD and neurotypical (NT) controls using a multivariate biomonitoring approach. Scalp hair samples were collected from 223 children (127 ASD and 96 NT), digested by microwave-assisted acid digestion, and analyzed by microwave-induced plasma optical emission spectrometry for the determination of Al, Ba, Ca, Cr, Fe, Mg, Mn, Ni, Pb, and Zn. Global differences were evaluated by permutation-based multivariate analysis of variance (PERMANOVA), followed by univariate analyses with false discovery rate correction and principal component analysis (PCA). Significant differences were observed between the overall hair elemental profiles of ASD and NT children (PERMANOVA, pseudo-F = 5.83, R²=0.0257, p < 0.001). Children with ASD exhibited higher hair concentrations of Al, Cr, and Pb, whereas Ba, Ca, and Mg were higher in NT controls. No significant differences were found for Fe, Mn, Ni, or Zn. Biological sex represented the strongest determinant of hair elemental profile (R²=0.081, p < 0.001), whereas dietary restrictions, psychotropic medication use, and ASD support level showed limited or no independent influence. Beyond identifying subtle alterations in elemental homeostasis associated with ASD, this work provides the first comprehensive dataset of hair elemental concentrations in Uruguayan children and establishes a baseline for future biomonitoring studies. These findings demonstrate that multielement hair analysis combined with multivariate statistics is a valuable approach for investigating elemental homeostasis in childhood.

Selenosugars are now recognized as the major end metabolites of selenium in mammals and play a central role in selenium detoxification and excretion. Since their discovery in the early 2000s, numerous studies have reported the occurrence of selenosugars in urine, tissues, and biological fluids of humans and animals. However, progress in the field has been hindered by inconsistent nomenclature, analytical limitations, and incomplete understanding of their metabolic origin and biological significance. In this position paper, we provide a comprehensive overview of the chemistry, occurrence, analysis, and metabolism of mammalian selenosugars. We propose a harmonized operational nomenclature that preserves essential structural information while facilitating communication among researchers. We critically evaluate analytical approaches used for selenosugar detection and quantification, including HPLC-ICP-MS, HPLC-ESI-MS, and NMR spectroscopy, and discuss their strengths, limitations, and appropriate applications. Based on accumulated evidence, we recommend minimum analytical criteria for reliable selenosugar identification and reporting. We further review the occurrence of naturally occurring selenosugars in humans and animals and integrate current knowledge into an updated metabolic framework. Adoption of the proposed nomenclature and analytical guidelines should improve consistency across studies and provide a foundation for future investigations into selenium metabolism and homeostasis.

We aimed to determine link between plasma metals concentration and the occurrence of fractures. We conducted a single-center prospective study at Rennes University Hospital. Two groups were compared: one with severe osteoporotic fractures (GMF) and a second with patients with pathological bone mineral density without fractures (GWF). Demographic data (sex, age, body mass index (BMI)), osteoporosis risk factors, along with a biological evaluation. Plasma concentrations of metals were assessed by ICP-MS. Bone mineral density was measured using the same device. A total of 221 patients were included (125 in the GMF and 96 in the GWF). GMF patients were older (77 ± 11 vs. 66 ± 13 years, p < 0.05) with no significant differences between the two groups in terms of sex, blood calcium, blood phosphorus, 25OH vitamin D, and PTH levels. In the overall population, ferritin levels were significantly higher in the GMF (272 ng/ml ± 276 vs. 200 ng/ml ± 227, p < 0.05), with this difference being mainly driven by the female population (GMF: 239 ng/ml ± 232 vs. GWF: 165 ng/ml ± 181, p < 0.05). Concerning metal concentrations, women in the GMF had significantly reduced concentrations of manganese and selenium (p < 0.05), while strontium levels were increased. In men, plasma concentrations of aluminum and cobalt were higher in the GMF (p < 0.05). Serum metal concentrations in patients with severe osteoporotic fractures varied according to sex. The increase in ferritin in women, and cobalt and aluminum in men, seems to be associated with the osteoporotic fractures' occurrence.

Tea consumption represents a primary dietary pathway for human exposure to heavy metals. In many countries, "tea rinsing"-the traditional practice of discarding the first infusion-is widely practiced, with some believing that this habit may reduce heavy metal intake. However, robust scientific evidence quantifying whether tea rinsing can effectively reduce heavy metal leaching and thereby mitigate associated health risks remains lacking. The study quantified the concentrations of ten elements (Pb, As, Cr, Co, Cd, Mn, Cu, Fe, Al, and Zn) in tea infusions before and after rinsing, and evaluated the mitigating effect of this practice on health risks using a probabilistic assessment. The results indicate that concentrations of Cr, Mn, Cu, Fe, and Zn decrease significantly (P < 0.05) following the first rinse. The rinsing procedure lowers the mean adult total carcinogenic risk by 36.2%, though all risk values remain within the acceptable regulatory range. Sensitivity analyses identify exposure duration and frequency as the primary drivers of these probabilistic risks. As emerges as the dominant contributor to carcinogenic risk. The findings suggest that discarding the initial tea infusion serves as a simple method to statistically reduce the intake of toxic elements from the evaluated teas.

Keshan disease (KD) is an endemic cardiomyopathy associated with selenium deficiency and distributed mainly along China's low-selenium belt. Sporadic cases continue to occur in some historically endemic areas despite elimination efforts. The national-scale ecological spatial association between KD prevalence and serum selenium levels remains unclear. This study examined their spatial association in China to support targeted prevention and long-term surveillance. Using 2020 national surveillance data, we applied ordinary Kriging interpolation with an exponential model to map selenium distribution. Global and local bivariate spatial autocorrelation analyses were conducted in GeoDa to assess spatial associations between serum selenium and KD prevalence. Kriging identified a northeast-to-southwest belt of selenium deficiency overlapping KD-endemic areas. Global bivariate autocorrelation showed weak but statistically significant negative spatial associations between serum selenium and overall KD prevalence (Moran's I = -0.047, P = 0.013) and latent Keshan disease (LKD) (Moran's I = -0.063, P = 0.002), but not chronic Keshan disease (CKD). Given the small Moran's I values, these results should be interpreted cautiously, as national-scale analysis may obscure local heterogeneity. Local analysis identified 67, 67, and 69 low-high clusters for KD, CKD, and LKD, respectively (203 in total across the three analyses). Serum selenium levels were weakly but significantly associated with KD prevalence spatial distribution in China. These findings indicate statistically detectable ecological spatial dependence, while no inference can be made regarding individual-level causality. The identified high-low clusters may be considered priority areas for targeted KD prevention and selenium monitoring.

This study explored the relationship between serum cadmium (Cd), smoking exposure, and migraine in the ELSA-Brasil cohort (2008-2010). The analysis included 2,750 participants whose serum Cd levels were measured using inductively coupled plasma mass spectrometry. Smoking exposure was assessed using self-report data of active smoking and second-hand smoke. Migraine, including definite and probable migraine, was diagnosed according to the International Classification of Headache Disorders, 3rd edition (ICHD-3). Logistic regression was used to estimate the odds of migraine across serum Cd quintiles, using the third quintile as the reference category, while linear regression examined the relationship between smoking exposure and Cd levels. Polynomial contrasts tested linear trends. Participants had a mean (SD) age of 53.2 (9.0) years and 53.1% were women. Migraine prevalence was 29.1% (including probable migraine). Individuals with migraine had slightly higher median serum Cd levels than controls [0.050 µg/L (IQR 0.035-0.077) vs. 0.048 µg/L (0.035-0.066); p = 0.021], although smoking exposure scores did not differ between groups. Smoking exposure showed a strong positive association with serum Cd concentrations (p-trend < 0.001). Participants in the highest Cd quintile had greater odds of migraine [aOR 1.51 (95% CI 1.09-2.08), p = 0.011] after adjustment for smoking exposure and sociodemographic and clinical confounders. Sex-stratified analysis yielded even stronger associations among males [aOR 1.84 (95% CI 1.07-3.16), p = 0.027]. However, in the sensitivity analysis including definite migraine cases only, this association was no longer significant [aOR: 1.14 (0.71, 1.83), p = 0.579]. Main findings suggest that Cd exposure from smoking may contribute to migraine occurrence, particularly in males. However, other sources of Cd that could influence migraine should not be disregarded, and future investigation in this field is warranted.

Raw cow milk serves as a critical nutritional resource yet may simultaneously act as a vehicle for toxic element exposure, particularly in regions where livestock management practices increase contamination risk. This study investigated the concentrations of six potentially toxic elements (PTEs), namely nickel (Ni), zinc (Zn), cadmium (Cd), copper (Cu), iron (Fe), and lead (Pb), in raw cow milk collected from 40 sites across Ranya district, Kurdistan Region of Iraq. Samples were analyzed using energy dispersive X-ray fluorescence (EDXRF) spectrometry, and human health risks were assessed through estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), and carcinogenic risk (CR) metrics across three age groups: adults, children, and infants. Detected metal concentrations followed a descending order of Zn > Fe > Ni > Cu > Pb > Cd. Several metals, including Fe, Cu, and Pb, exceeded permissible thresholds. Health risk evaluation revealed that while mean THQ and HI values for adults and children remained within acceptable boundaries, infants exhibited mean HI values surpassing the safety threshold of 1.0, indicating a genuine cumulative non-carcinogenic risk. Carcinogenic risk assessment identified Ni as the predominant concern, with CR values exceeding acceptable limits across all age groups, most markedly in infants. The elevated contamination levels observed are attributable largely to the practice of grazing livestock on unmanaged pastures and allowing consumption of water from natural, untreated sources. These findings underscore the necessity of continuous PTE surveillance in raw dairy products and the implementation of targeted public health interventions to safeguard vulnerable populations, particularly infants, within the study region.

Rare earth elements and yttrium (REE + Y) are increasingly mobilized in modern environments, affecting human physiological processes through multiple exposure pathways. Pathological biominerals, such as kidney stones, may provide valuable records of long-term elemental deposition. However, it remains unclear whether REE + Y directly inherit environmental signals or are reshaped by physiological and mineralogical processes. This study analyzed kidney stones from a high-incidence karst region in eastern Yunnan, China. The results indicate that regional hydrogeochemical background and the mineralogical pathways jointly control the REE + Y distribution of kidney stones. Fourier transform infrared spectroscopy combined with non-negative matrix factorization identified the dominant spectral components and their relative proportions in the stones. The total REE + Y load was mainly controlled by the dominant mineral phase, with the median in uric acid stones (36.4 ng/g) remaining significantly lower than in calcium-bearing stones (up to 218.2 ng/g). This study further found that increasing phosphate proportions were significantly correlated with weaker Yb anomalies and higher Lu concentrations, whereas total REE concentrations showed no significant change. Unsupervised and supervised model analyses demonstrated that REE + Y distribution patterns can reliably distinguish stones with different dominant mineral types. These results indicate that REE + Y are sensitive to biomineralization processes in kidney stones and may serve as potential tracers for apatite incorporation in calcium-bearing stones. Moreover, although human metabolism and biomineralization filter most environmental signals, the light REE-enriched patterns in calcium-bearing stones are broadly compatible with the karst hydrogeochemical background. Overall, this study reveals the REE + Y fingerprints support precise subtyping of kidney stones, serving as composite geochemical archives reflecting both environmental signals and pathological biomineralization.