Hexavalent chromium and stomach cancer: a systematic review and meta-analysis

Evaluation of Health Risks Associated with Potential Toxic Elements in Selected Vegetables Consumed in the Western Black Sea Region of Turkey

Vegetables with useful phytochemicals, vitamins, protein, carbohydrates, and minerals are nutritional sources and play an important role in the prevention of many chronic diseases. However, vegetables are contaminated with potentially toxic elements caused by anthropogenic and natural activities. Therefore, this study is the first attempt to analyze 14 potentially toxic elements in some of the most consumed vegetables in Kastamonu province located in the Western Black Sea Region of Turkey by using an ICP-OES for the evaluation of the potential human health risks of adults due to potentially toxic elements via ingestion. The concentrations (μg/kg, dw) of Fe, Al, Sr, Mn, Zn, Ti, Cu, Ni, Pb, V, As, Cr, Cd, and Co analyzed in sixty-nine samples belonging to thirty-six different vegetable types varied from 3995 to 968073, 569 to 616664, 2730 to 144287, 843 to 51417, 268 to 34344, Collapse

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Affiliation(s)

Aydan Altıkulaç Muğla Sıtkı Koçman University, Ula Ali Koçman Vocational School, 48640 Ula, Muğla, Turkey
Şeref Turhan Kastamonu University, Department of Physics, Faculty of Science, 37150 Kastamonu, Turkey
Ergin Murat Altuner Kastamonu University, Department of Biology, Faculty of Science, 37150 Kastamonu, Turkey
Barış Şekeroğlu Kastamonu University, Department of Physics, Faculty of Science, 37150 Kastamonu, Turkey
Aslı Kurnaz Kastamonu University, Department of Physics, Faculty of Science, 37150 Kastamonu, Turkey

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High-efficient nickel-doped lignin carbon dots as a fluorescent and smartphone-assisted sensing platform for sequential detection of Cr(VI) and ascorbic acid

Using lignin as a raw material to prepare fluorescent nanomaterials represents a significant pathway toward the high-value utilization of waste biomass. In this study, Ni-doped lignin carbon dots (Ni-LCDs) were rapidly synthesized with a yield of 63.22 % and a quantum yield of 8.25 % using a green and simple hydrothermal method. Exploiting the inner filter effect (IFE), Cr(VI) effectively quenched the fluorescence of the Ni-LCDs, while the potent reducing agent ascorbic acid (AA) restored the quenched fluorescence, thus establishing a highly sensitive fluorescence switch sensor platform for the sequential detection of Cr(VI) and AA. Importantly, the integration of a smartphone facilitated the portability of Cr(VI) and AA detection, enabling on-site, in-situ, and real-time monitoring. Ultimately, the developed fluorescence and smartphone-assisted sensing platform was successfully applied to detect Cr(VI) in actual water samples and AA in various fruits. This study not only presents an efficient method for the conversion and utilization of waste lignin but also broadens the application scope of the CDs in the field of smart sensors.

An umbrella review of the evidence associating occupational carcinogens and cancer risk at 19 anatomical sites

Occupational exposure to carcinogens of increasing cancer risk have been extensively suggested. A robust assessment of these evidence is needed to guide public policy and health care. We aimed to classify the strength of evidence for associations of 13 occupational carcinogens (OCs) and risk of cancers. We searched PubMed and Web of Science up to November 2022 to identify potentially relevant studies. We graded the evidence into convincing, highly suggestive, suggestive, weak, or not significant according to a standardized classification based on: random-effects p value, number of cancer cases, 95% confidence interval of largest study, heterogeneity between studies, 95% prediction interval, small study effect, excess significance bias and sensitivity analyses with credibility ceilings. The quality of meta-analysis was evaluated by AMSTAR 2. Forty-eight articles yielded 79 meta-analyses were included in current umbrella review. Evidence of associations were convincing (class I) or highly suggeastive (class II) for asbestos exposure and increasing risk of lung cancer among smokers (RR = 8.79, 95%CI: 5.81-13.25 for cohort studies and OR = 8.68, 95%CI: 5.68-13.24 for case-control studies), asbestos exposure and increasing risk of mesothelioma (RR = 4.61, 95%CI: 2.57-8.26), and formaldehyde exposure and increasing risk of sinonasal cancer (RR = 1.68, 95%CI: 1.38-2.05). Fifteen associations were supported by suggestive evidence (class III). In summary, the current umbrella review found strong associations between: asbestos exposure and increasing risk of lung cancer among smokers; asbestos exposure and increasing risk of mesothelioma; and formaldehyde exposure and higher risk of sinonasal cancer. Other associations might be genuine, but substantial uncertainty remains.

The Impact of Exposure to Hexavalent Chromium on the Incidence and Mortality of Oral and Gastrointestinal Cancers and Benign Diseases: A Systematic Review of Observational Studies, Reviews and Meta-Analyses

Background: Limited evidence suggests a possible connection between natural or occupational exposure to chromium and an increased risk of gastrointestinal cancer. The main objective of this study is to investigate the literature regarding chromium exposure and gastrointestinal health issues (i.e., cancer). Methods: A systematic literature search was performed using PubMed, Google Scholar and ScienceDirect. Included observational studies were assessed for their risk of bias. Results: 16 observational studies and 7 reviews and meta-analyses met the inclusion criteria. Most of the studies investigated gastric and hepatocellular cancer, followed by colorectal, oral, esophageal and pancreatic cancer. There is a limited amount of evidence regarding non-malignant gastrointestinal diseases. Chromium exposure is suspected to increase gastric and colorectal cancer risks. We did not find any convincing indications for increases in oral, esophageal and hepatocellular cancer. Pancreatic, gallbladder and extrahepatic bile ducts carcinogenesis is likely not associated with chromium exposure. Conclusion: We found weak evidence that chromium exposure is associated with gastric and colorectal cancer. Our review also highlights the existing controversial evidence regarding oral, esophageal and hepatocellular cancer, as well as the gap in studies investigating small intestinal cancer and non-malignant gastrointestinal health issues.

Maternal vitamin D in pregnancy and infant's gut microbiota: a systematic review

Background

An infant's gut microbiome plays a vital role in their health, and various factors can impact their gut microbiota composition. This review aimed to summarize the current knowledge regarding the associations between maternal prenatal supplementation with vitamin D and the composition of infants' gut microbiota.

Method

A comprehensive systematic search was done on Web of Science, Scopus, PubMed, ScienceDirect, and Google Scholar databases without date restrictions until December 2022 using relevant keywords. All relevant original articles in English were eligible for the present review.

Results

Eight articles (two mice, three randomized clinical trials, and three cohort studies) were included in this review. The included mice studies reported that maternal prenatal vitamin D supplementation significantly affects the offspring's gut microbiome composition (such as enhancing the abundance of colonic Bacteroides). Moreover, the included cohort studies revealed a significant association between maternal supplementation with vitamin D during pregnancy and the infant's gut microbiome. However, one-third of clinical trials indicated that vitamin D levels in utero could influence the colonization of the microbial community in the infant's gut.

Conclusion

The findings of this review revealed that maternal vitamin D supplementation during pregnancy was linked to an infant's gut microbiome and could impact their gut microbiota composition. However, more studies are warranted to confirm these results.

Influence of Garlic on the Glycemic Control and Lipid Profile in Animals with Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-analysis

Nonalcoholic fatty liver disease is the hepatic sign of metabolic syndrome. Here, we aimed to assess the effects of garlic and its major components on fasting plasma glucose, fasting insulin, and lipid profile levels in animal models of nonalcoholic fatty liver disease. A systematic search in PubMed, Scopus, ProQuest, and Web of Science was performed. After the screening process and data extraction, the pooled effect sizes were estimated using a random-effect model and stated as standardized mean differences and a 95% confidence interval. Out of 839 reports, 22 articles were included in the present study. The pooled results revealed that garlic and its components significantly decreased fasting plasma glucose (standardized mean difference: - 0.77, 95% confidence interval: - 1.42 to - 0.12, I2 : 58.85%), fasting insulin (standardized mean difference: - 1.88, 95% confidence interval: - 3.07 to - 0.69, I2 : 70.42%), serum triglyceride (standardized mean difference: - 1.01, 95% confidence interval: - 1.43 to - 0.59, I2 : 61.41%), cholesterol (standardized mean difference: - 1.00, 95% confidence interval: - 1.39 to - 0.60, I2 : 52.12%), and low-density lipoprotein cholesterol (standardized mean difference: - 0.98, 95% CI: - 1.63 to - 0.32, I2 : 71.58%) and increased high-density lipoprotein cholesterol (standardized mean difference: 1.05, 95% confidence interval: 0.52 to 1.58, I2 : 59.39%) levels. The type of animal, nonalcoholic fatty liver disease induction model, kind and duration of intervention, study model, and risk of bias were detected as possible sources of heterogeneity across studies. We conclude that garlic and its major components have a favorable impact on glycemic control and lipid profile in diet-induced nonalcoholic fatty liver disease animal models.

A review on chromium health hazards and molecular mechanism of chromium bioremediation

Living beings have been devastated by environmental pollution, which has reached its peak. The disastrous pollution of the environment is in large part due to industrial wastes containing toxic pollutants. The widespread use of chromium (Cr (III)/Cr (VI)) in industries, especially tanneries, makes it one of the most dangerous environmental pollutants. Chromium pollution is widespread due to ineffective treatment methods. Bioremediation of chromium (Cr) using bacteria is very thoughtful due to its eco-friendly and cost-effective outcome. In order to counter chromium toxicity, bacteria have numerous mechanisms, such as the ability to absorb, reduce, efflux, or accumulate the metal. In this review article, we focused on chromium toxicity on human and environmental health as well as its bioremediation mechanism.

The concentration of potentially toxic elements (PTEs) in Iranian rice: a dietary health risk assessment study

In the present study, six potentially toxic elements (PTEs), including chromium (Cr), arsenic (As), cadmium (Cd), lead (Pb), copper (Cu), and nickel (Ni), were determined in 41 domestic rice samples collected from Tehran using ICP-OES (inductively coupled plasma-optical emission spectrometry). The mean concentration of Cd, As, Cu, Pb, Cr, and Ni was found as 0.014 ± 0.01, 0.018 ± 0.005, 2.15 ± 1.84, 0.42 ± 0.31, 0.1 ± 0.16, and 0.48 ± 0.36 mg kg-1, respectively. Possible risks due to ingestion of PTEs via rice consumption for children and adults were assessed by Monte Carlo simulation. The 50th percentile of estimated Cr intake for children through domestic rice consumption exceeded the maximum tolerable daily intake. There was only a potential non-carcinogenic risk for single Cr exposure for children. The 95th percentile of the estimated hazard index (HI) for children and adults was 4.34 and 1.05, indicating a potential non-carcinogenic risk related to multiple PTE exposure. The lifetime cancer risk (ILCR) values derived from Cr, Ni, As, and Cd exposure exceeded the threshold value, indicating a carcinogenic risk due to PTEs' exposure. The deterministic assessment demonstrates that the Tehran population may be at risk through domestic rice consumption. This study indicates that risk related to the exposure to multiple PTEs through the consumption of rice in adults and children in Tehran is recognized as an important issue, thus supporting the importance of cumulative analysis of the risk of exposure to PTEs through food. Finally, national strategic environmental assessment and technological solutions for monitoring and protecting freshwater, soil, waste management, and chemicals as a global concern policy are needed for public health.

Biogeochemical behaviour and toxicology of chromium in the soil-water-human nexus: A review

Chromium (Cr) affects human health if it accumulates in organs to elevated concentrations. The toxicity risk of Cr in the ecosphere depends upon the dominant Cr species and their bioavailability in the lithosphere, hydrosphere, and biosphere. However, the soil-water-human nexus that controls the biogeochemical behaviour of Cr and its potential toxicity is not fully understood. This paper synthesizes information on different dimensions of Cr ecotoxicological hazards in the soil and water and their subsequent effects on human health. The various routes of environmental exposure of Cr to humans and other organisms are also discussed. Human exposure to Cr(VI) causes both carcinogenic and non-carcinogenic health effects via complicated reactions that include oxidative stress, chromosomal and DNA damage, and mutagenesis. Chromium (VI) inhalation can cause lung cancer; however, incidences of other types of cancer following Cr(VI) exposure are low but probable. The non-carcinogenic health consequences of Cr(VI) exposure are primarily respiratory and cutaneous. Research on the biogeochemical behaviour of Cr and its toxicological hazards on human and other biological routes is therefore urgently needed to develop a holistic approach to understanding the soil-water-human nexus that controls the toxicological hazards of Cr and its detoxification.

Serum cobalt and chromium concentration following total hip arthroplasty: a Bayesian network meta-analysis

The present systematic review investigated the concentration of chromium (Cr) and cobalt (Co) in serum in patients who have undergone total hip arthroplasty (THA). The first outcome of interest was to investigate the mean concentration in serum of Cr and Co using different material combinations and to verify whether their concentrations change significantly using different patterns of head and liner in THA. The second outcome of interest was to investigate whether the time elapsed from the index surgery to the follow-up, BMI, sex, and side exert an influence on the mean concentration of Cr and Co in serum in patients who have undergone THA. The following material combinations were investigated (head-liner): Ceramic-Co Cr (CoCr), CoCr-CoCr, CoCr-Polyethylene, CoCr high carbide-CoCr high carbide. Data from 2756 procedures were retrieved. The mean length of follow-up was 69.3 ± 47.7 months. The ANOVA test evidenced good comparability in age, length of follow-up, BMI, and sex (P > 0.1). In patients who have undergone THA, the mean concentration in the serum of Co ranged between 0.5 µg/L and 3.5 µg/L, and the mean concentration of Cr from 0.6 to 2.6 µg/L. The difference in the concentration of Co and Cr in serum is strictly related to the implant configuration, with the coupling CoCr-CoCr showing the highest and CoCr-Polyethylene showing the lowest concentration. Patient characteristics, BMI, sex, side and the time elapsed from the index surgery to the last follow-up did not exert a significant influence on the concentration of Co and Cr in serum in patients who have undergone total hip arthroplasty (THA).

Insights into the evolution of Cr(VI) species in long-term hexavalent chromium contaminated soil

Compare to the content of Cr(VI), the distribution of specific Cr(VI) species in soil is rarely paid attention to, which may lead to an inaccurate environmental risk assessment of Cr(VI) contaminated soil or inability to meet stringent requirement for soil remediation. Herein, to reveal the primary mechanisms and factors controlling the evolution of Cr(VI) species in soil, the distribution of Cr(VI) and Cr(III) species in soils with different particle sizes and textures was systematically investigated by using a modified sequential extraction procedure and spectroscopy characterizations (e.g., SEM-EDS mapping). The results show that a significant proportion of Cr(VI) can be captured by minerals containing exchangeable calcium ions and metal oxide hydrates in the soil, forming a relatively stable adsorbed Cr(VI). Also, a small fraction of Cr(VI) can precipitate as calcium chromate with free calcium ion which is the most stable Cr(VI) species in the soil. The majority of Cr(VI) discharged into soil tends to be reduced by ferrous ions or minerals containing ferrous ions with a product of Fe(III)-Cr(III) coprecipitate. Therefore, the speciation of Cr in the soil is closely correlated to Fe and Ca. After the equilibrium of adsorption, precipitation, and reduction reactions of Cr(VI), the rest of Cr(VI) retains as the form of its original water-soluble state in soil. The evolution of Cr(VI) species and the content of specific Cr species in soil are mainly determined by the contents of iron, exchangeable calcium ions and metal oxide hydrates, which effect the Cr(VI) reduction, precipitation and adsorption, respectively.

Development of a reporting guideline for systematic reviews of animal experiments in the field of traditional Chinese medicine

OBJECTIVE

In recent years, there are several systematic reviews published on animal experiments of Traditional Chinese medicine (TCM). PRISMA (preferred reporting items for systematic reviews and meta-analysis) guidelines provide a guarantee for significantly improving the reporting quality of systematic reviews (SRs) and meta-analysis (MAs) to a certain extent; however, there are still certain defects found in the quality of SRs/MAs of animal experiments of TCM. It has been found that especially, the descriptions of the rationale and animal characteristics of TCM interventions are inadequate. As a result, we have developed a novel reporting guideline for SRs/MAs of animal experimental in the field of TCM (PRISMA-ATCM) to overcome these problems.

METHODS

PRISMA-ATCM reporting guidelines were formed by analyzing both the status and quality of published SRs/MAs of animal experiments and consulting experts in the related fields, and then by Delphi consultation, consensus meeting and revision.

RESULTS

Among the 27 items on the PRISMA checklist, Title (1), Structured summary (2), Rationale (3), Objectives (4), Protocol and registration (5), Eligibility criteria (6), Data items (11), Planned methods of analysis (14), Study characteristics (18), Summary of evidence (24), Limitations (25), and Funding (27) have been extensively revised and expanded, to specifically include the details about TCM intervention and animal characteristics. In addition, illustrative examples and explanations have been provided for each item.

CONCLUSION

PRISMA-ATCM could markedly improve the quality SRs/MAs of animal experiments in the field of TCM.

Effects of Alkali on Water Soluble Hexavalent Chromium in Ordinary Portland Cement

Due to the toxicity and mobility of chromium, the disposal of chromium-containing waste is a pressing issue. Co-processing of chromium-containing waste in a cement kiln is currently one of the most effective methods. However, the presence of water-soluble hexavalent chromium (Cr(VI)) in cement limits the use of this method. In this study, Na₂CO₃ was used to simulate alkali in industrial raw materials to investigate the pattern of influence of alkali content on water-soluble hexavalent chromium. The mechanisms associated with the oxidation and dissolution of chromium were investigated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma emission spectrometry (ICP-OES). The proportion of Cr(VI) in the clinker detected by XPS increased rapidly with increasing alkali content. In the cement slurry system, alkali promotes more hexavalent chromium leaching by influencing pH and other ion concentrations (Ca²⁺, SO₄²⁻). Therefore, the addition of alkali to either the raw meal or to the cement slurry system will favour an increase in the water-soluble Cr(VI) content. This study may provide theoretical guidance for the preparation and use of clinkers containing chromium.

Environmental factors associated with gastric carcinogenesis

PURPOSE OF REVIEW

Gastric cancer is one of the leading causes of cancer-related deaths globally. Several modifiable environmental factors have been linked to gastric carcinogenesis but in many cases, evidence is either weak or fragmented. In this review, we interrogate the latest evidence implicating environmental factors in the development of gastric cancer.

RECENT FINDINGS

We are writing this review at a time when technological advancements are enabling scientists to effectively conduct large epidemiological studies with better tools for exposure estimations. We have highlighted risk factors that do not yet have enough evidence to be included as definite carcinogens in the International Agency for Research on Cancer monographs but have the potential for inclusion in the near future. Considered in our review are the links between gastric cancer and exposure to biomass smoke, particulate matter, occupational hazards and water contamination.

SUMMARY

This review illustrates the need for vigilance as evidence linking gastric cancer to various environmental factors is mounting. Many of these factors are modifiable, allowing for preventive strategies that could further decrease the global burden of gastric cancer.

Ultrasound Image-Guided Nerve Block Combined with General Anesthesia under an Artificial Intelligence Algorithm on Patients Undergoing Radical Gastrectomy for Gastric Cancer during and after Operation

This study was aimed at investigating the location of gastric cancer by using a gastroscope image based on an artificial intelligence algorithm for gastric cancer and the effect of ultrasonic-guided nerve block combined with general anesthesia on patients undergoing gastric cancer surgery. A total of 160 patients who were undergoing gastric cancer surgery from March 2019 to March 2021 were collected as the research objects, and the convolutional neural network (CNN) algorithm was used to segment the gastroscope image of gastric cancer. The patients were randomly divided into a simple general anesthesia group of 80 cases and a transversus abdominis plane block combined with rectus abdominis sheath block combined with the general anesthesia group of 80 cases. Then, compare the systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) at the four time points T0, T1, T2, and T3. The times of analgesic drug use within 48 hours after operation and postoperative adverse reactions were recorded. The visual analog scale (VAS) scores were also recorded at 4 h, 12 h, 24 h, and 48 h. The results show that the image quality after segmentation is good: the accuracy of tumor location is 75.67%, which is similar to that of professional endoscopists. Compared with the general anesthesia group, the transversus abdominis plane block combined with the rectus sheath block combined with the general anesthesia group had fewer anesthetics, and the difference was statistically significant (P < 0.05). Compared with the general anesthesia group, SBP, DBP, and HR were significantly reduced at T1, T2, and T3 in the transverse abdominis plane block combined with rectus sheath block and general anesthesia group (P < 0.05). Compared with the simple general anesthesia group, the VAS scores of the transversus abdominis plane block combined with rectus sheath block combined with the general anesthesia group decreased at 4 h, 12 h, and 24 h after surgery, and the difference was statistically significant (P < 0.05). The number of analgesics used in transversus abdominis plane block combined with the rectus sheath block combined with the general anesthesia group within 48 hours after operation was significantly less than that in the general anesthesia group, and the difference was statistically significant (P < 0.05). The average incidence of adverse reactions in the nerve block combined with the general anesthesia group was 2.5%, which was lower than the average incidence of 3.75% in the general anesthesia group. In summary, the CNN algorithm can accurately segment the lesions in the ultrasonic images of gastric cancer, which was convenient for doctors to make a more accurate judgment on the lesions, and provided a basis for the preoperative examination of radical gastrectomy for gastric cancer. Ultrasonic-guided nerve block combined with general anesthesia can effectively improve the analgesic effect of radical gastrectomy for gastric cancer, reduced intraoperative and postoperative adverse reactions and analgesic drug dosage, and had a good effect on postoperative recovery of patients. The combined application of these two methods can further improve the precision treatment of gastric cancer patients and accelerate postoperative recovery.

Curcumin and rheumatoid arthritis: A systematic review of literature

BACKGROUND

Curcumin is a natural polyphenol and the main compound from the rhizome of Turmeric (Curcuma longa) and other Curcuma species. It has been widely used for different medical purposes, such as improvement of pain and inflammatory conditions in various diseases.

PURPOSE

This systematic review was aimed to assess all studies regarding the efficacy of the pure form of curcumin (unformulated curcumin) on rheumatoid arthritis (RA).

METHODS

The comprehensive search of the literature was done until September 2020 on the MEDLINE, Embase, Scopus and Web of Knowledge databases. Out of 2079 initial records, 51 articles (13 in vitro and 37 animal and one human) were met our inclusion criteria.

RESULTS

Most studies have shown the curative effects of curcumin on clinical and inflammatory parameters of RA and reported different mechanisms; inhibition of mitogen-activated protein kinase family, extracellular signal-regulated protein kinase, activator protein-1 and nuclear factor kappa B are the main mechanisms associated with the anti-inflammatory function of curcumin in RA. The results of the only human study showed that curcumin significantly improved morning stiffness, walking time and joint swelling.

CONCLUSION

In conclusion, curcumin seems to be useful, and it is recommended that more human studies be performed to approve the cellular and animal results and determine the effective and optimal doses of curcumin on RA patients.

Resveratrol and Markers of Polycystic Ovary Syndrome: a Systematic Review of Animal and Clinical Studies

Polycystic ovary syndrome (PCOS) is a common disorder affecting childbearing-age women, and is associated with reproductive and metabolic disturbances. The present study aimed to systematically review current animal studies and randomized placebo-controlled clinical trials (RCT) regarding the effects of resveratrol, a natural polyphenolic compound, on PCOS features. PubMed, Scopus, Web of Knowledge, and Google Scholar were comprehensively searched until December 2020. All original animal articles and RCTs evaluating the effects of resveratrol on PCOS were eligible for the review. Out of 289 initial records, eight animal studies and three RCTs met our inclusion criteria. Most of the included animal studies reported beneficial effects of resveratrol on the histomorphological features, sex hormones and gonadotropins, glycemic control, inflammation, and oxidative stress. Resveratrol also ameliorated ovarian volume, high-quality oocyte rate, high-quality embryo rate, androgens and gonadotropins concentrations, angiogenic factors levels, and endoplasmic reticulum stress in PCOS patients. Upregulation of sirtuin-1 was an examined mechanism proposed for some observed effects of resveratrol. The current literature is limited to conclude the beneficial effects of resveratrol on the management of PCOS. Although, according to the promising results of the animal studies and limited RCTs, resveratrol might be an effective phytochemical in PCOS control, especially regarding hormonal and reproductive abnormalities. More mechanistic studies and RCTs are warranted to obvious whether resveratrol can be prescribed in the clinical situation.

Ipomoea staphylina Attenuates Potassium Dichromate-Induced Nephrotoxicity in Wistar Rats via Antioxidant and Antiapoptotic Effects

Occupational and environmental exposure to chromium compounds leads to nephrotoxicity to humans and animals due to the overproduction of ROS. Our study was aimed to demonstrate the shielding effect of hydroethanolic extract of Ipomoea staphylina (HEIS) bark on male Wistar rats challenged with potassium dichromate (K2Cr2O7). Division of animals was done in 4 groups' viz., normal control, K2Cr2O7 control, K2Cr2O7+HEIS (100 mg/kg), and K2Cr2O7+HEIS (200 mg/kg). Except for the normal control group, other groups were challenged with a single dose (subcutaneous) of K2Cr2O7 (15 mg/kg) and then treated with HEIS (100 and 200 mg/kg) for 1 week. It was observed that animals treated with K2Cr2O7 showed a notable increase in serum creatinine, blood urea, and BUN and dwindles in protein level. These changes were significantly reversed after a 1-week treatment with HEIS (100 and 200 mg/kg). Moreover, HEIS (100 and 200 mg/kg) showed a remarkable improvement in the activity of antioxidant enzymes (GPx, CAT, and SOD) and decreased the levels of TNF-α and IL-1β in the kidney. Furthermore, treatment with HEIS (100 and 200 mg/kg) notably decreased the activity of caspase-3 and improved the level of HO-1 especially in the K2Cr2O7+ HEIS (200 mg/kg) group. Also, the histopathological study of the kidney supported the protective effects of HEIS. Hence, HEIS bark holds a notable protective effect against K2Cr2O7-induced nephrotoxicity in rats.

Exposição potencial a baixas doses de cromo por via oral e mortalidade por câncer de estômago na população do interior do Estado de São Paulo, Brasil

Resumo: Concentrações de cromo total entre 0,45 e 110µg/L têm sido detectadas, no Sistema Aquífero Bauru (SAB) no Estado de São Paulo, Brasil, excedendo, algumas vezes, o padrão de qualidade adotado pela legislação brasileira, que é de 50μg/L. Segundo a Companhia Ambiental do Estado de São Paulo (CETESB), parte do cromo é composta pela forma hexavalente [Cr(VI)], que apresenta controversas evidências quanto à carcinogenicidade por via oral. Este artigo tem como objetivo avaliar o efeito da exposição ao Cr(VI) em baixas doses na mortalidade por câncer gástrico da população entre 15 e 75 anos ou mais, que consumiu água do SAB, no período entre 2004 e 2015. Foi realizado um estudo ecológico em 326 municípios situados no Planalto Ocidental Paulista e que usam água do SAB. As associações foram estimadas pelo modelo de regressão linear, utilizando-se indicadores de exposição ao cromo (proxy) e razão de mortalidade padronizada (RMP) para as neoplasias gástricas como variável resposta. O Índice de Desenvolvimento Humano Municipal (IDHM) foi empregado para controlar possíveis diferenças socioeconômicas da população investigada. A RMP estimada para o câncer gástrico correspondeu a 79% dos óbitos esperados, sendo que o risco foi menor nos municípios que têm água tratada pela Companhia de Saneamento Básico do Estado de São Paulo (SABESP), com especial atenção para a população feminina (β = -0,146; IC95%: -0,270; -0,021; p = 0,022). Embora os dados da pesquisa sejam limitados, em 77 (23,6%) dos municípios avaliados, houve aumento do risco de câncer gástrico. Dentre esses, quase 70% se abastecem de manancial subterrâneo, associado às bacias hidrográficas com anomalias geoquímicas de Cr(VI).

Cobalt–Chromium Dental Alloys: Metal Exposures, Toxicological Risks, CMR Classification, and EU Regulatory Framework

During the 20th century, metal alloys have assumed an important role as restorative materials. Among existing examples, cobalt–chromium (Co–Cr) alloys increasingly began to be used in medicine and especially in dentistry. Their success is mainly due to their mechanical properties such as stiffness, strength and corrosion resistance, thus allowing a high biocompatibility. There are quite meaningful data on the corrosion and toxicity of Co–Cr alloys for their use in restorative materials such as dental prostheses. Toxicological studies following Co and Cr exposures in the oral cavity are more difficult to conduct because there are many different situations leading to the release of metal ions and wear particles. Furthermore, the links between exposure and the appearance of local or systemic toxicity are not automatic. Since 2017, the European Union (EU) regulatory framework for Co–Cr alloys has been undergoing profound changes. A new EU Medical Devices Regulation (MDR) (2017/745) will be applied in May 2021 with the need to consider that Co metal is a new carcinogenic, mutagenic and toxic to reproduction (CMR) substance. On 18 February 2020, the 14th Adaptation to Technical Progress (ATP14) to the Classification, Labelling and Packaging (CLP) regulation was published, including the harmonised classification for Co metal as a CMR 1B substance. In this context, the use of Co might be forbidden if the medical devices are invasive and as soon as they include more than 0.1% (m/m) Co. This review provides a specific overview on Co–Cr dental alloys in terms of metal ions and wear particles release, toxicological risks, and the actual and new EU regulatory framework.

Adsorption of Cr (VI) onto micro- and nanoparticles of palygorskite in aqueous solutions: Effects of pH and humic acid

Palygorskite is a mineral widely applied for the removal of potentially toxic trace elements from the environment. This study aimed to identify the influence of pH (3, 4, 5, and 6) and humic acid (200 mg L^-1) addition on the adsorption of hexavalent chromium (Cr (VI)) ions by the microparticles and nanoparticles of palygorskite. Therefore, the mineral was prepared as the micron- and nano-sized particles saturated with Ba²⁺ ions, and finally used in adsorption experiments. The results indicated that regardless of the mineral size, Cr(VI) adsorption was enhanced by increasing the contact time from 5 to 2880 min and the equilibrium conditions achieved after 1440 min from the beginning of experiments. With increasing the pH values from 3 to 6, the adsorption efficiency of Cr(VI) decreased significantly, and the highest rate of removal (64%) was found at pH = 3. The pseudo-second-order model best described the kinetics of Cr(VI) adsorption onto both micro- and nanoparticles of palygorskite. Also, the experimental data showed maximum consistency with the data calculated by the Freundlich isotherm model. The two processes of film and pore diffusion were recognized as the main mechanisms that controlled the adsorption of Cr(VI) by palygorskite microparticles and nanoparticles. A comparison of the maximum adsorption capacity of Cr(VI) in different treatments followed the order of nanoparticles > humic acid > humic acid + nanoparticles ≈ humic acid + microparticles > microparticles. Accordingly, the adsorption capacities of "palygorskite nanoparticles" and "humic acid" for Cr(VI) ions were 3.7 and 3.2 times higher than that of palygorskite microparticles, respectively. Moreover, the adsorption capacities observed in the simultaneous application of humic acid with palygorskite microparticles and nanoparticles were 20% and 45% lower than those without humic acid, respectively. To conclude, palygorskite nanoparticles were found to have a significant adsorption capacity for Cr(VI) ions, which is negatively affected by rise in the pH of the aqueous matrix.

An adverse outcome pathway for small intestinal tumors in mice involving chronic cytotoxicity and regenerative hyperplasia: a case study with hexavalent chromium, captan, and folpet

Small intestinal (SI) tumors are relatively uncommon outcomes in rodent cancer bioassays, and limited information regarding chemical-induced SI tumorigenesis has been reported in the published literature. Herein, we propose a cytotoxicity-mediated adverse outcome pathway (AOP) for SI tumors by leveraging extensive target species- and site-specific molecular, cellular, and histological mode of action (MOA) research for three reference chemicals, the fungicides captan and folpet and the transition metal hexavalent chromium (Cr(VI)). The gut barrier functions through highly efficient homeostatic regulation of SI epithelial cell sloughing, regenerative proliferation, and repair, which involves the replacement of up to 10¹¹ cells per day. This dynamic turnover in the SI provides a unique local environment for a cytotoxicity mediated AOP/MOA. Upon entering the duodenum, cytotoxicity to the villous epithelium is the molecular initiating event, as indicated by crypt elongation, villous atrophy/blunting, and other morphologic changes. Over time, the regenerative capacity of the gut epithelium to compensate declines as epithelial loss accelerates, especially at higher exposures. The first key event (KE), sustained regenerative crypt proliferation/hyperplasia, requires sufficient durations, likely exceeding 6 or 12 months, due to extensive repair capacity, to create more opportunities for the second KE, spontaneous mutation/transformation, ultimately leading to proximal SI tumors. Per OECD guidance, biological plausibility, essentiality, and empirical support were assessed using modified Bradford Hill considerations. The weight-of-evidence also included a lack of induced mutations in the duodenum after up to 90 days of Cr(VI) or captan exposure. The extensive evidence for this AOP, along with the knowledge that human exposures are orders of magnitude below those associated with KEs in this AOP, supports its use for regulatory applications, including hazard identification and risk assessment.

Processes of chromium (VI) migration and transformation in chromate production site: A case study from the middle of China

The migration and redox transformation processes of toxic Cr(VI) in the upper and deep soil of chromate-polluted site are of great importance for the environmental risk control and soil remediation. In this study, soils from surface to deep (around 30-60 m) and the groundwater in a typical abandoned chromate production plant site which has experienced decades of contamination were both sampled and analyzed. The results show that the soil in the leaching workshop of Cr(VI), dichromate transformation workshop and chromium slag dumping ground exhibits severe contamination of chromium and the pollution has extended to the groundwater, causing serious pollution in groundwater too. The vertical migration and transformation of Cr(VI) in the soil layer are mainly affected by the soil permeability, organic matter content and the amount of water passing through the soil layer. During the downward migration, Cr(VI) tends to be retained by the clay layer and further accumulates around the depth of 5-10 m where the concentrations of both hexavalent and total Cr reach maximum values, and then continues to diffuse from the accumulation layer towards the deeper soil. Accompanying with the reduction of Cr(VI) by organic matter in the soil, the Cr(III) exists at various depths. When the depth is below the groundwater level of saturated aquifer, the distribution of chromium in the soil and groundwater reaches leaching and redox equilibrium due to the long-term interaction between the soil and groundwater.

Metal-Metal Hip Prosthesis and Kidney Cancer: Assumed Role of Chromium and Cobalt Overload

Patient: Female, 68-year-old

Final Diagnosis: Bilateral renal carcinoma

Symptoms: Bleeding of renal track • discomfort

Medication: —

Clinical Procedure: Cancer nodule removal • prosthesis replacement • radiotherapy

Specialty: Neurology • Orthopedics and Traumatology

Chromium Pollution in European Water, Sources, Health Risk, and Remediation Strategies: An Overview

Chromium is a potentially toxic metal occurring in water and groundwater as a result of natural and anthropogenic sources. Microbial interaction with mafic and ultramafic rocks together with geogenic processes release Cr (VI) in natural environment by chromite oxidation. Moreover, Cr (VI) pollution is largely related to several Cr (VI) industrial applications in the field of energy production, manufacturing of metals and chemicals, and subsequent waste and wastewater management. Chromium discharge in European Union (EU) waters is subjected to nationwide recommendations, which vary depending on the type of industry and receiving water body. Once in water, chromium mainly occurs in two oxidation states Cr (III) and Cr (VI) and related ion forms depending on pH values, redox potential, and presence of natural reducing agents. Public concerns with chromium are primarily related to hexavalent compounds owing to their toxic effects on humans, animals, plants, and microorganisms. Risks for human health range from skin irritation to DNA damages and cancer development, depending on dose, exposure level, and duration. Remediation strategies commonly used for Cr (VI) removal include physico-chemical and biological methods. This work critically presents their advantages and disadvantages, suggesting a site-specific and accurate evaluation for choosing the best available recovering technology.

Metal Element Detection and Carcinogenicity Risk Assessment of PM2.5 Samples

The objective of the present study was to conduct metal element analysis and carcinogenicity risk assessment of particulate matter with an aerodynamic diameter <2.5 μm (PM_2.5 ) from Shenzhen and Taiyuan. Samples of PM_2.5 were collected in Shenzhen and Taiyuan during the yeas 2017 and 2018. Ten heavy metal elements were detected by inductively coupled plasma mass spectrometry. Health risk was assessed using the recommended US Environmental Protection Agency model. Metal elements found in PM_2.5 samples from Shenzhen included (in decreasing order of concentration) Al, Pb, Mn, Cr, Cu, V, As, Ni, Cd, and Co. Metal elements found in Taiyuan included (in decreasing order of concentration) Al, Mn, Pb, Cr, Cu, As, Ni, V, Cd, and Co. There were significant differences in Pb, Mn, Al, As, and Ni levels between Shenzhen and Taiyuan (p < 0.05); but the remaining element levels did not show significant differences between the 2 cities. Risk-assessment data showed higher total risk from 5 carcinogenic metal elements in Taiyuan (3.79 × 10^-4 ) compared to Shenzhen (2.44 × 10^-4 ): Cr had the highest carcinogenicity risk (>10^-4 ), followed by As, Ni, and Cd (10^-6  ~ 10^-4 ), and Pb had the lowest risk (<10^-6 ). The results indicated that some of the metal elements in PM_2.5 samples from Shenzhen and Taiyuan pose a carcinogenicity risk; further research and measures for prevention and control should be considered. Environ Toxicol Chem 2020;39:1273-1276. © 2020 SETAC.

[General and particular issues of etiopathogenesis of peptic ulcer and gastric cancer: current status of the problem]

The development of peptic ulcer (PU) and gastric cancer (GC) is the result of the interaction of various internal and external factors. Moreover, if the role ofHelicobacter pylori(H. pylori) in the development of diseases of the stomach is fully established, the significance of many other factors continues to be discussed. Serious controversy is caused by the participation of various strains ofH. pyloriin the development of PU and GC. First of all, these are Vac- and Cag-positive strains ofH. pylori. The role of genetic human polymorphism in the development of this pathology is debatable. Especially the interleukin genes and necrotizing tumor factor alpha. The role of environmental factors in the formation of PU and GC is not fully understood. So, the role of alcohol, occupational hazards and drugs in the development of these diseases continues to be discussed. Further study of risk factors for various diseases of the stomach will optimize their prevention and treatment. The review presents a modern view of individual issues in the pathogenesis of PU and GC.

Dietary natural methylxanthines and colorectal cancer: a systematic review and meta-analysis

Some evidence suggests that caffeine, theophylline, and theobromine, as natural methylxanthines (MTXs), possess anti-cancer effects.

The First-Row Transition Metals in the Periodic Table of Medicine

In this manuscript, we describe medical applications of each first-row transition metal including nutritional, pharmaceutical, and diagnostic applications. The 10 first-row transition metals in particular are found to have many applications since there five essential elements among them. We summarize the aqueous chemistry of each element to illustrate that these fundamental properties are linked to medical applications and will dictate some of nature’s solutions to the needs of cells. The five essential trace elements—iron, copper, zinc, manganese, and cobalt—represent four redox active elements and one redox inactive element. Since electron transfer is a critical process that must happen for life, it is therefore not surprising that four of the essential trace elements are involved in such processes, whereas the one non-redox active element is found to have important roles as a secondary messenger.. Perhaps surprising is the fact that scandium, titanium, vanadium, chromium, and nickel have many applications, covering the entire range of benefits including controlling pathogen growth, pharmaceutical and diagnostic applications, including benefits such as nutritional additives and hardware production of key medical devices. Some patterns emerge in the summary of biological function andmedical roles that can be attributed to small differences in the first-row transition metals.