Blood toxic metals and hemoglobin levels in Mexican children

Association of exposure to multiple metals with hemoglobin levels in Chinese children and adolescents

BACKGROUND

Previous studies have linked single metal to hemoglobin levels in children and adolescents; however, studies with regards to metal mixtures are still limited.

OBJECTIVE

We aimed to investigate the associations of single metal and metal mixtures with hemoglobin levels in children and adolescents.

METHODS

We conducted a cross-sectional study of 2064 children and adolescents aged 6 to 19 years in Liuzhou, China in 2018. The concentrations of 15 metals in urine were determined by inductively coupled plasma mass spectrometry. Generalized linear regression and weighted quantile sum (WQS) regression were used to estimate the associations of single metal and metal mixtures with hemoglobin levels, respectively.

RESULTS

The multivariable-adjusted β-values for the highest versus the first quartiles of urinary metal concentrations were - 1.57 (95 % confidence interval [CI]: -3.01, -0.13) for chromium, -2.47 (95 % CI: -3.90, -1.05) for nickel and 1.88 (95 % CI: 0.49, 3.28) for copper. In addition, we found a significant negative association between the WQS index and hemoglobin levels (adjusted β = -0.93, 95 % CI: -1.69, -0.19), with nickel contributing the most to the WQS index at 59.0 %. Subgroup analyses showed that exposure to urinary nickel or metal mixtures were associated with decreased hemoglobin levels in adolescents, but not in children (all Pinteration < 0.001).

CONCLUSION

Among children and adolescents, urinary chromium and nickel concentrations were associated with decreased hemoglobin levels, while copper showed a positive relationship. Moreover, a negative association was observed between exposure to metal mixtures and hemoglobin levels. These findings need to be further validated in prospective studies.

Horse Whole Blood Trace Elements from Different Sicily Areas: Biomonitoring of Environmental Risk

Horses are excellent bioindicators for the assessment of environmental pollution. The aim of this study was to evaluate the levels and potential bioaccumulation of 28 mineral elements in 75 horse whole blood samples collected from five pollution-prone areas of Sicily, Italy. A direct mercury analyzer (DMA-80) was used for Hg determination, and an inductively coupled plasma mass spectrometer (ICP-MS) for all other elements. A one-way ANOVA test, followed by Bonferroni's multiple comparison for post hoc comparison, was applied to assess statistically significant differences between mineral elements and the five experimental groups. The levels of mineral elements in hay and concentrate were below the limits set by Regulation No. 744/2012. The mineral content of whole blood samples was slightly influenced by the region of origin of the horse. p values < 0.05 were statistically meaningful. However, the concentrations of mineral elements in horses' whole blood remained within reference ranges. In conclusion, the present study shows that the mineral content does not represent a toxicological risk for the analyzed horses. In addition, the study areas did not appear to show a high mineral element contamination.

Trace Element Concentrations in Autopsied Heart Tissues from Patients with Secondary Cardiomyopathy

Cardiomyopathies (CMP) represent a significant health problem as they have a poor long-term prognosis and often require transplantation. Heavy metals are known to have cardiotoxic effects and some of them, such as cadmium (Cd), are found to be elevated in the urine and blood of individuals with heart diseases; nevertheless, direct measurement of metals (e.g. zinc (Zn) which is necessary for normal heart function), in the myocardium of individuals with CMP has not been performed. Here, we aimed to analyze the levels of a group of metals in the myocardium of the left ventricle in individuals with CMP. At the Institute of Pathology, we collected 52 samples of left ventricle post-mortem, out of which 19 subjects had been diagnosed with CMP (mean age: 72 y ± 10), and 33 subjects had not suffered from any heart disease (mean age: 67 y ± 15). We found out that individuals with CMP had a significantly higher concentrations of lead, nickel, manganese and copper than non-CMP subjects (p = 0.002, p < 0.001, p = 0.011, and p = 0.002). Interestingly, zinc was significantly lower in CMP subjects than in n-CMP individuals (p = 0.017). Our results indicated the involvement of an increased lead, nickel, copper and manganese heart load in individuals with CMP coupled with lower concentrations of zinc.

Mechanisms Associated with Cognitive and Behavioral Impairment Induced by Arsenic Exposure

Arsenic (As) is a metalloid naturally present in the environment, in food, water, soil, and air; however, its chronic exposure, even with low doses, represents a public health concern. For a long time, As was used as a pigment, pesticide, wood preservative, and for medical applications; its industrial use has recently decreased or has been discontinued due to its toxicity. Due to its versatile applications and distribution, there is a wide spectrum of human As exposure sources, mainly contaminated drinking water. The fact that As is present in drinking water implies chronic human exposure to this metalloid; it has become a worldwide health problem, since over 200 million people live where As levels exceed safe ranges. Many health problems have been associated with As chronic exposure including cancer, cardiovascular diseases, gastrointestinal disturbances, and brain dysfunctions. Because As can cross the blood-brain barrier (BBB), the brain represents a target organ where this metalloid can exert its long-term toxic effects. Many mechanisms of As neurotoxicity have been described: oxidative stress, inflammation, DNA damage, and mitochondrial dysfunction; all of them can converge, thus leading to impaired cellular functions, cell death, and in consequence, long-term detrimental effects. Here, we provide a current overview of As toxicity and integrated the global mechanisms involved in cognitive and behavioral impairment induced by As exposure show experimental strategies against its neurotoxicity.

Kindergarten indoor dust metal(loid) exposure associates with elevated risk of anemia in children

Exposure to metals and metalloids in indoor dust is associated with adverse health effects in young children, but there is limited evidence for an association with anemia, which is at high risk in children. The aim of this study was to investigate the association between exposure to multiple metal(loid)s in indoor dust in kindergartens and the risk of anemia in children. In 2021, 2165 children from 25 kindergartens in eastern China were included in the study and had their hemoglobin (Hb) measured. Indoor dust samples were collected from the children's kindergartens, and the concentrations of 11 metals and metalloids in the samples were measured using inductively coupled plasma mass spectrometry (ICP-MS). The daily exposure dose (DED) of dust was used to assess the risk of metal(loid) exposure in the children. The results showed that of the 2165 children with available data, 351 (16.2 %) met the WHO definition of anemia. In multiple linear regression and logistic regression analyses, we found that for each quartile of DED increase in Cd inhalation, child Hb levels decreased by 2.703 g/L (95 % CI: -4.055, -1.351), and the risk of anemia increased 1.602-fold (95 % CI: 1.087, 2.360). Mn ingestion was associated with increased odds of anemia [odds ratio (OR) = 1.760 (95 % CI: 1.217, 2.544)]. Interaction analysis indicated that metal(loid)s exposure effects were modified by child sex, age, and body mass index (BMI). Cluster analysis found that children at high risk of metal(loid) exposure in the school environment tended to have lower Hb levels and higher prevalence of anemia compared with those at low risk, although this was not statistically significant. These findings suggest that child school exposure to metal(loid)s in indoor dust is associated with an increased risk of developing anemia in children, modified by child sex, age, and BMI.

Environmental Metal Exposure, Neurodevelopment, and the Role of Iron Status: a Review

PURPOSE OF REVIEW

Exposure to environmental metals, like lead (Pb), manganese (Mn), and methylmercury (Me-Hg), has consistently been implicated in neurodevelopmental dysfunction. Recent research has focused on identifying modifying factors of metal neurotoxicity in childhood, such as age, sex, and co-exposures. Iron (Fe) status is critical for normal cognitive development during childhood, and current mechanistic, animal, and human evidence suggests that Fe status may be a modifier or mediator of associations between environmental metals and neurodevelopment. The goals of this review are to describe the current state of the epidemiologic literature on the role of Fe status (i.e., hemoglobin, ferritin, blood Fe concentrations) and Fe supplementation in the relationship between metals and children's neurodevelopment, and to identify research gaps.

RECENT FINDINGS

We identified 30 studies in PubMed and EMBASE that assessed Fe status as a modifier, mediator, or co-exposure of associations of Pb, Me-Hg, Mn, copper (Cu), zinc (Zn), arsenic (As), or metal mixtures measured in early life (prenatal period through 8 years of age) with cognition in children. In experimental studies, co-supplementation of Fe and Zn was associated with better memory and cognition than supplementation with either metal alone. Several observational studies reported interactions between Fe status and Pb, Mn, Zn, or As in relation to developmental indices, memory, attention, and behavior, whereby adverse associations of metals with cognition were worse among Fe-deficient children compared to Fe-sufficient children. Only two studies quantified joint associations of complex metal mixtures that included Fe with neurodevelopment, though findings from these studies were not consistent. Findings support memory and attention as two possible cognitive domains that may be both vulnerable to Fe deficiency and a target of metals toxicity. Major gaps in the literature remain, including evaluating Fe status as a modifier or mediator of metal mixtures and cognition. Given that Fe deficiency is the most common nutritional deficiency worldwide, characterizing Fe status in studies of metals toxicity is important for informing public health interventions.

Varying Doses of Rare-Earth-Metal-Based Neodymium Zirconate Zinc Sulfide Nanocomposite Disrupt Blood and Serum Parameters, as well as Markers of Oxidative Stress in the Selected Organs of Albino Mice

Despite extensive industrial use, the biocompatibility of nanocomposites has not been extensively explored. The present study was designed to report the effect of variable doses of a newly synthesized nanocomposite, Neodymium Zirconate Zinc Sulfide, on selective serum and complete blood count parameters and on the oxidative stress markers from the vital organs of albino mice. Albino mice (C57BL/6 strain, 5 weeks old) of both sexes were orally treated for 11 days, either with 10 mg (low dose) or 20 mg/mL saline/kg body weight (high dose) of Neodymium Zirconate Zinc Sulfide nanocomposite. A control group that was not treated with the nanocomposite but with saline solution was also maintained. Data analysis revealed that high-dose nanocomposite-treated male mice had significantly reduced hemoglobin concentration as compared to the control males. Female mice treated with both doses of nanocomposite had higher serum triglyceride levels than controls. High-dose-treated female mice had elevated serum cholesterol concentration compared to their saline-treated controls. Oxidative stress marker analysis from selected organs indicated that concentrations of malonaldehyde (MDA) in the kidney and liver, Superoxide dismutase (SOD) levels in the brain and catalase in the kidney of male mice treated with the nanocomposite were significantly higher than in the control group, whereas SOD in the heart, MDA in the heart and kidney and catalase levels in the kidney were significantly disrupted in female mice compared to their respective controls.

The Relationship Between Preeclampsia and Arsenic Concentration in the Peripheral Blood

Preeclampsia (PE) is a pregnancy-specific disorder, which is one of the leading causes of maternal, fetal, and neonatal death, particularly in developing countries. Arsenic (As), which is commonly found in soil and groundwater, has been associated with various complications of pregnancy, such as spontaneous abortion, hypertension, and stillbirth. Hence, the study was used to explore the relationship between PE and blood concentration of As in this study. Blood concentration of As during pregnancy was measured by inductively coupled plasma mass spectrometry (ICP-MS). The results shown that the mean blood concentration of As was gradually increased from the control group to the severe PE group (P < 0.0001). Elevated blood concentration of As was associated with the prevalence of PE (OR = 12.81, 95% CI: 2.43-67.39 and 27.55, 1.75-433.43 for middle and high vs. low). Furthermore, elevated blood concentration of As was associated with the severity of PE. Additionally, we observed that blood concentration of As was associated with the hypoproteinemia (P = 0.001, rs = 0.37). Blood concentration of As was negatively corelated with the mean corpuscular volume (MCV) (P = 0.040, rs =  - 0.23) and positively corelated with the mean corpuscular hemoglobin concentration (MCHC) (P = 0.044, rs = 0.23). Overall, our results indicated that the blood concentration of As can significantly predict the occurrence of PE. Additionally, we provided evidence that blood concentration of As may affect the occurrence of hypoproteinemia. These findings may provide some ideas for the prevention of PE and pregnancy complications.

Lead and Cadmium Bioaccumulation in Fresh Cow's Milk in an Intermediate Area of the Central Andes of Peru and Risk to Human Health

The dairy basin of the Mantaro River located in the centre of Peru faces serious anthropogenic disturbances as it receives emissions and discharges from the metallurgical mining activity located in the headwaters of the basin and milk contaminated with lead (Pb) and cadmium (Cd) endangers the environmental and human health, especially children. To measure the concentrations of Pb and Cd in milk and the dangers of their consumption in the Peruvian population, 40 milk samples were collected and quantified by atomic absorption spectrometry. The mean concentration of Pb in milk was 15 ± 2.6 µg/kg, which represented 75% of the Maximum Limit (ML), and that of Cd was 505 ± 123 µg/kg, which exceeded the ML by more than 194 times. The estimated weekly intake of Pb for people aged 2−85 years was below the Provisional Tolerable Weekly Intake (PTWI) references, determining risk coefficients (CRD) < 1. Weekly Cd intake was much higher than the PTWIs and CRDs were between 14 and 34, indicating that consumers would experience carcinogenic health effects, with children being at higher risk than adults, therefore, milk from the area is not safe for consumption. Cd would be transferred mainly through the soil (water)-grass-milk pathway, due to its presence in irrigation water and in fertilizers that contain Cd. The main pathway for Pb entry would be air-soil (water)-milk grass, from the fine particles emitted into the air by the mining-metallurgical activity, developed approximately 90 km from the study area.

Renal hypoxia-HIF-PHD-EPO signaling in transition metal nephrotoxicity: friend or foe?

The kidney is the main organ that senses changes in systemic oxygen tension, but it is also the key detoxification, transit and excretion site of transition metals (TMs). Pivotal to oxygen sensing are prolyl-hydroxylases (PHDs), which hydroxylate specific residues in hypoxia-inducible factors (HIFs), key transcription factors that orchestrate responses to hypoxia, such as induction of erythropoietin (EPO). The essential TM ion Fe is a key component and regulator of the hypoxia–PHD–HIF–EPO (HPHE) signaling axis, which governs erythropoiesis, angiogenesis, anaerobic metabolism, adaptation, survival and proliferation, and hence cell and body homeostasis. However, inadequate concentrations of essential TMs or entry of non-essential TMs in organisms cause toxicity and disrupt health. Non-essential TMs are toxic because they enter cells and displace essential TMs by ionic and molecular mimicry, e. g. in metalloproteins. Here, we review the molecular mechanisms of HPHE interactions with TMs (Fe, Co, Ni, Cd, Cr, and Pt) as well as their implications in renal physiology, pathophysiology and toxicology. Some TMs, such as Fe and Co, may activate renal HPHE signaling, which may be beneficial under some circumstances, for example, by mitigating renal injuries from other causes, but may also promote pathologies, such as renal cancer development and metastasis. Yet some other TMs appear to disrupt renal HPHE signaling, contributing to the complex picture of TM (nephro-)toxicity. Strikingly, despite a wealth of literature on the topic, current knowledge lacks a deeper molecular understanding of TM interaction with HPHE signaling, in particular in the kidney. This precludes rationale preventive and therapeutic approaches to TM nephrotoxicity, although recently activators of HPHE signaling have become available for therapy.

Exposure to heavy metals and red blood cell parameters in children: A systematic review of observational studies

BACKGROUND

Mechanistic studies show that heavy metals interfere with the hematopoietic system by inhibiting key enzymes, which could lead to anemia. However, the link between children's exposure and red blood cell (RBC) parameters has been inconsistent. We aimed to summarize evidence on human studies exploring the association between exposure to lead, mercury, cadmium, arsenic, and chromium VI and RBC parameters in children.

METHODS

Following the PRISMA guidelines, we searched PubMed, Scopus, and Web of Science databases for studies published between January 2010 and April 2022. Eligible papers included human observational studies that directly assessed exposure (internal dose) to the heavy metals under study and RBC parameters in participants aged ≤ 18 years. We excluded studies using hospital-based samples. Study quality was assessed using the National Institutes of Health's Quality Assessment Tools for Cohort and Cross-Sectional Studies. We synthesized the evidence using vote counting based on the direction of the relationship.

RESULTS

Out of 6,652 retrieved papers, we included a total of 38 (33 assessing lead, four mercury, two cadmium, and two arsenic; chromium VI was not assessed in any included paper). More than half of the studies were conducted in Asia. We found evidence of a positive relationship between lead concentration and hemoglobin (proportion of studies reporting negative relationships = 0.750; 95% Confidence Interval (CI) 0.583, 0.874) and mean corpuscular hemoglobin (0.875; 95% CI 0.546, 0.986), and a positive relationship with red cell distribution width (0.000; 95%CI 0.000, 0.379). When considering only good-quality studies (24% of the Pb studies), only the relationship with hemoglobin levels remained (0.875; 95% CI: 0.546, 0.986).

CONCLUSION

We found evidence of a negative relationship between lead concentration and hemoglobin and mean corpuscular hemoglobin and of a positive relationship with red cell distribution width in children. We also identified a need to conduct more studies in European countries. Future studies should use standardized practices and make efforts to increase study quality, namely by conducting comprehensive longitudinal studies. Our findings support the need to take further actions to limit heavy metal exposure during childhood.

Transfer of lead from soil to pasture grass and milk near a metallurgical complex in the Peruvian Andes

Milk quality is affected by the concentration of lead (Pb) in soil and pasture grasses used to raise cattle, especially in areas near mining-metallurgical complexes. In this study, the Pb content of soil and its transfer to grass and dairy milk in an area located to 20 km from the La Oroya Metallurgical Complex in Peru (altitude, >3,700 m s.a.l) was measured. Twenty soil samples (0–30 cm depth), 20 grass samples were collected, and 0.5 L of milk was obtained from 20 lactating cow in the communal cowshed. The Pb concentration (mg/kg) was quantified by flame atomic absorption spectrometry using a commercial Pb standard as quality control. The Pb average concentration in the soil, grass, and milk samples were 217.81 ± 39.48, 20.09 ± 2.83, and 0.58 ± 0.018 mg/kg (P < 0.01), respectively. The transfer factor (ratio of metal concentration) for Pb from soil to grass and from grass to milk was 0.095 and 0.031, respectively. The soil, grass, and milk samples all presented high Pb concentrations, with the milk samples containing 29-fold more Pb than the safety limit established by European regulations and were not suitable for human consumption or the manufacture of cheese, yogurt, and other derivatives. Our findings demonstrate that action to remediate these soils is critically needed.

Data on multiple regression analysis between boron, nickel, arsenic, antimony, and biological substrates in horses: The role of hematological biomarkers

The objective of this study was to evaluate the biomarkers of exposure to boron, nickel, arsenic, and antimony in an industrial region, evaluating the bioaccumulation in biological substrates and the correlation with biomarkers such as hematological parameters. Through indication of the accumulation of some minerals in the horse's biological substrates reflects environmental pollution. Moreover, an additional aim of the study was to show whether these contaminants have an influence on the hematological parameters in horses. Blood, serum, mane, and tail samples from 20 horses from an industrial area were analyzed to determine boron (B), nickel (Ni), arsenic (As), antimony (Sb) concentration. Hematological parameters (red blood cell [RBC], white blood cells [WBC], hemoglobin [Hb], hematocrit [Hct], mean corpuscular volume [MCV], mean corpuscular hemoglobin [MCH], mean corpuscular hemoglobin concentration [MCHC], platelet [PLT]) as a biomarker of blood in relation to the bioaccumulation of these elements were analyzed also. Descriptive statistical analysis was performed and single regression analysis (Pearson) and multiple regression analysis (p < 0.05) between blood factors, As, B, Ni, and Sb concentrations, and for each mineral in different substrate, respectively. Results showed a significant correlation between tail and mane concentrations with serum and blood for boron concentration (r = -1 p < 0.05). No significant correlation between sample (feed, hay, mane, tail, and water) concentrations and As, Ni, and Sb were found. A significantly negative correlation with blood parameters (r = -1 p < 0.05) was observed in Boron concentration for mane and tail. This suggests that the mane and tail may be a potential means to investigate suspected exposure to excessive levels of trace minerals.

Arsenic exposure and non-carcinogenic health effects

Inorganic arsenic (iAs) exposure is a serious health problem that affects more than 140 million individuals worldwide, mainly, through contaminated drinking water. Acute iAs poisoning produces several symptoms such as nausea, vomiting, abdominal pain, and severe diarrhea, whereas prolonged iAs exposure increased the risk of several malignant disorders such as lung, urinary tract, and skin tumors. Another sensitive endpoint less described of chronic iAs exposure are the non-malignant health effects in hepatic, endocrine, renal, neurological, hematological, immune, and cardiovascular systems. The present review outlines epidemiology evidence and possible molecular mechanisms associated with iAs-toxicity in several non-carcinogenic disorders.

Blood's Concentration of Lead and Arsenic Associated with Anemia in Peruvian Children

This exploratory, descriptive cohort study (N = 60) determined lead (Pb) and arsenic (As) blood concentrations in Peruvian children and their association with hematological parameters of iron-deficient anemia (IDA) and anthropometric measurement. The mean age of children was 10.8 months (SD = 4.7) and ranged from 3 to 24 months old. Anemia (Hb levels below 10.5 g/dL) was found in 20% of this cohort. Additionally, microcytosis (MCV < 70 fL) was present in 54%, and hypochromia (MCH < 23 pg) in 42% of the group of children. Chi-square analysis showed that 88% of the children with anemia also had microcytosis and hypochromia (p < 0.001). Pb and As were detected in 100% of the infants' blood samples, and the concentrations were significantly higher in older infants than in younger ones. Pb and As were not associated with the sex, anthropomorphic parameters, or infant hemogram changes. Infants who received iron supplementation were 87% less likely to have low Hb compared with those who did not (OR = 0.13, 95% CI = 0.02–0.88, p=0.04). Herbal tea intake was significantly associated with microcytosis and hypochromia. Our finding uncovered that hematological parameters for anemia are modified in Peruvian children with high levels of microcytosis and hypochromia. Concentrations of Pb and As were above method detection limits in all Peruvian children, but these were not associated with IDA or anthropometric measurements. A large study, including other variables, would benefit from allowing a more complex model predicting anemia in Peruvian children.

Are Titania Photocatalysts and Titanium Implants Safe? Review on the Toxicity of Titanium Compounds

Titanium and its compounds are broadly used in both industrial and domestic products, including jet engines, missiles, prostheses, implants, pigments, cosmetics, food, and photocatalysts for environmental purification and solar energy conversion. Although titanium/titania-containing materials are usually safe for human, animals and environment, increasing concerns on their negative impacts have been postulated. Accordingly, this review covers current knowledge on the toxicity of titania and titanium, in which the behaviour, bioavailability, mechanisms of action, and environmental impacts have been discussed in detail, considering both light and dark conditions. Consequently, the following conclusions have been drawn: (i) titania photocatalysts rarely cause health and environmental problems; (ii) despite the lack of proof, the possible carcinogenicity of titania powders to humans is considered by some authorities; (iii) titanium alloys, commonly applied as implant materials, possess a relatively low health risk; (iv) titania microparticles are less toxic than nanoparticles, independent of the means of exposure; (v) excessive accumulation of titanium in the environment cannot be ignored; (vi) titanium/titania-containing products should be clearly marked with health warning labels, especially for pregnant women and young children; (vi) a key knowledge gap is the lack of comprehensive data about the environmental content and the influence of titania/titanium on biodiversity and the ecological functioning of terrestrial and aquatic ecosystems.

Health effects of arsenic exposure in Latin America: An overview of the past eight years of research

Studies conducted over the past eight years in Latin America (LA) have continued to produce new knowledge regarding health impacts of arsenic (As) in drinking water. We conducted a systematic review of 92 peer-reviewed English articles published between 2011 and 2018 to expand our understanding on these health effects. Majority of the LA studies on As have been conducted in Chile and Mexico. Additional data have emerged from As-exposed populations in Argentina, Bolivia, Brazil, Colombia, Ecuador, and Uruguay. The present review has documented recent data on the biomarkers of As exposure, genetic susceptibility and genotoxicity, and risk assessment to further characterize the health effects and exposed populations. Some recent findings on the associations of As with bladder and lung cancers, reproductive outcomes, and declined cognitive performance have been consistent with what we reported in our previous systematic review article. We have found highly convincing evidence of in utero As exposure as a significant risk factor for several health outcomes, particularly for bladder cancer, even at moderate level. New data have emerged regarding the associations of As with breast and laryngeal cancers as well as type 2 diabetes. We observed early life As exposure to be associated with kidney injury, carotid intima-media thickness, and various pulmonary outcomes in children. Other childhood effects such as low birth weight, low gestational age, anemia, increased apoptosis, and decreased cognitive functions were also reported. Studies identified genetic variants of As methyltransferase that could determine susceptibility to As related health outcomes. Arsenic-induced DNA damage and alteration of gene and protein expression have also been reported. While the scope of research is still vast, the substantial work done on As exposure and its health effects in LA will help direct further large-scale studies for more comprehensive knowledge and plan appropriate mitigation strategies.

Vanadium in Biological Action: Chemical, Pharmacological Aspects, and Metabolic Implications in Diabetes Mellitus

Vanadium compounds have been primarily investigated as potential therapeutic agents for the treatment of various major health issues, including cancer, atherosclerosis, and diabetes. The translation of vanadium-based compounds into clinical trials and ultimately into disease treatments remains hampered by the absence of a basic pharmacological and metabolic comprehension of such compounds. In this review, we examine the development of vanadium-containing compounds in biological systems regarding the role of the physiological environment, dosage, intracellular interactions, metabolic transformations, modulation of signaling pathways, toxicology, and transport and tissue distribution as well as therapeutic implications. From our point of view, the toxicological and pharmacological aspects in animal models and humans are not understood completely, and thus, we introduced them in a physiological environment and dosage context. Different transport proteins in blood plasma and mechanistic transport determinants are discussed. Furthermore, an overview of different vanadium species and the role of physiological factors (i.e., pH, redox conditions, concentration, and so on) are considered. Mechanistic specifications about different signaling pathways are discussed, particularly the phosphatases and kinases that are modulated dynamically by vanadium compounds because until now, the focus only has been on protein tyrosine phosphatase 1B as a vanadium target. Particular emphasis is laid on the therapeutic ability of vanadium-based compounds and their role for the treatment of diabetes mellitus, specifically on that of vanadate- and polioxovanadate-containing compounds. We aim at shedding light on the prevailing gaps between primary scientific data and information from animal models and human studies.

Hematotoxicity of intratracheally instilled arsenic trioxide in rats

The study aimed to investigate the correlation between concentration of inhaled arsenic trioxide and dynamic changes in hematotoxicity in rats. Wistar rats were randomly divided into four study groups that were treated with saline (control) or arsenic trioxide at a low (0.1 mg/mL), medium (1 mg/mL), or high (10 mg/mL) dose by intratracheal instillation. Blood samples were collected for analysis at 6, 12, 24, 48, and 72 h after exposure. Compared with the control group, intratracheal instillation of arsenic trioxide affected hematopoietic differentiation in rats, leading to blood cell changes that were related to observation time and concentration.

Blood levels of toxic metals and rare earth elements commonly found in e-waste may exert subtle effects on hemoglobin concentration in sub-Saharan immigrants

Pollution by heavy metals and more recently by rare earth elements (REE) and other minor elements (ME) has increased due in part to their high use in technological and electronic devices. This contamination can become very relevant in those sites where e-waste is improperly processed, as it is the case in many countries of the African continent. Exposure to some toxic elements has been associated to certain hematological disorders, specifically anemia. In this study, the concentrations of 48 elements (including REE and other ME) were determined by ICP-MS in whole blood samples of sub-Saharan immigrants with anemia (n=63) and without anemia (n=78). We found that the levels of Fe, Cr, Cu, Mn, Mo, and Se were significantly higher in the control group than in the anemia group, suggesting that anemia was mainly due to nutritional deficiencies. However, since other authors have suggested that in addition to nutritional deficiency, exposure to some elements may influence hemoglobin levels, we wanted to explore the role of a broad panel of toxic and "emerging" elements in hemoglobin deficiency. We found that the levels of Ag, As, Ba, Bi, Ce, Eu, Er, Ga, La, Nb, Nd, Pb, Pr, Sm, Sn, Ta, Th, Tl, U and V were higher in anemic participants than in controls. For most of these elements an inverse correlation with hemoglobin concentration was found. Some of them also correlated inversely with blood iron levels, pointing to the possibility that a higher rate of intestinal uptake of these could exist in relation to a nutritional deficiency of iron. However, the higher levels of Pb, and the group of REE and other ME in anemic participants were independent of iron levels, pointing to the possibility that these elements could play a role in the development of anemia.