Cadmium and lead levels in human liver and kidney samples obtained from Bursa Province

Chronic exposure to low-dose cadmium facilitated nonalcoholic steatohepatitis in mice by suppressing fatty acid desaturation

Exposure to cadmium (Cd), a toxic metal, is epidemiologically linked to nonalcoholic steatohepatitis (NASH) in humans. However, the role of Cd in NASH remains to be fully elucidated. This study employed a novel murine NASH model to investigate the effects of chronic low-dose Cd on hepatic pathology and its underlying mechanisms. NASH is characterized by lipid accumulation, extensive cell death, and persistent inflammation in the liver. We found that treatment with Cd in drinking water (10 mg/L) for 6 or 12 weeks significantly boosted hepatic fat deposition, increased hepatocyte destruction, and amplified inflammatory responses in mice, confirming that low-dose Cd can facilitate NASH development in vivo. Mechanistically, chronic Cd exposure reshaped the hepatic transcriptional landscape, with PPAR-mediated fatty acid metabolic pathways being the most significantly altered. In particular, Cd repressed fatty acid desaturation, leading to the accumulation of saturated fatty acids whose lipotoxicity exacerbated cell death and, consequently, inflammatory activation. In summary, we validated the causal effects of chronic low-dose Cd on NASH in vivo and identified the fatty acid desaturation program as a novel target for Cd to instigate hepatopathological alterations.

Changes in heavy metal levels, reproductive characteristics, oxidative stress markers and testicular apoptosis in rams raised around thermal power plant

Male reproductive dysfunction is one of the damages in the organism caused by heavy metals. In this study, it was aimed to investigate the changes in heavy metal levels in serum and testicular tissue, and serum hormone levels, epididymal spermatozoa characteristics, tissue oxidative stress levels, testicular histology and testicular apoptosis level in rams raised in remote and near regions of a thermal power plant. A total of 75 rams were divided into 3 groups according to the regions, where they were born and raised, being far [250 km distance, group 1 (control), n = 25], close (20 km distance, group 2, n = 25) and very close (10 km distance, group 3, n = 25) to the thermal power plant. The blood along with testis and epididymis tissues was taken from the animals after slaughtering. In addition, soil and water heavy metal analyzes were also performed. The highest levels of serum Al, Cr, As, Ag, Sn and testicular Al, V, Ni, Ag, Cd, Cr, As, Pb, and the lowest levels of serum Cu, testicular Cu and Zn were determined in group 3 compared to control. Soil and water heavy metal results were similar to those found in serum and testis. The lowest serum testosterone level, tissue glutathione-peroxidase and catalase activities, spermatozoon concentration, and the highest tissue malondialdehyde level, dead spermatozoon rate, Bax apoptotic protein expression level and Bax/Bcl-2 rate alongside some testicular histopathological lesions were found in group 3 in comparison to control. Significant correlations were determined between some heavy metal levels and some parameters measured. As a result, heavy metals accumulate in the soil and water in the region close to the thermal power plant. The endocrine and exocrine reproductive potentials of rams born and grown in these regions were clearly damaged by the increased testicular heavy metals due to water drank and herbs consumed.

The association between lead and cadmium co-exposure and renal dysfunction

Both cadmium (Cd) and lead (Pb) exposure can induce kidney damage. However, the effects of combined exposure to Cd and Pb on renal function at environmental levels have not been fully clarified. In this study we investigated the renal function in a Chinese population co-exposed to Cd and Pb. A total of 331 subjects (215 women and 116 men), living in either a control or a polluted area, were included in this study. Cd and Pb in blood and urine (BCd, BPb, UCd, and UPb), and kidney effect markers including urinary N-acetyl-β-D-glucosaminidase (UNAG) and estimated glomerular filtration rate (eGFR), were determined, and the association between exposure markers and renal effect biomarkers were analyzed. The exposure levels in the polluted area were significantly higher than in the control area (all p < 0.01). The eGFR of subjects in the polluted area was decreased compared with that in the control area (p < 0.01). The subjects with high BCd/BPb (BCd ≥ 2 μg/L, BPb ≥ 100 μg/L) or high UCd/UPb (UCd ≥ 3 μg/g creatinine, UPb ≥ 10 μg/g creatinine) showed higher UNAG and UALB levels compared with other subgroups (p < 0.01). The probability of having elevated UNAG in subjects with high BCd/BPb was greater than those with low BCd/BPb [odds ratio (OR) = 2.6, 95% confidence interval (CI): 1.4-4.7), low BCd/high BPb (OR =3.1, 95% CI: 1.4-6.6), and high BCd/low BPb (OR = 1.7, 95% CI: 0.9-3.2). The OR of subjects with low UCd and high UPb, high UCd and low UPb, and high UCd/UPb were 2.9 (95% CI: 1.4-5.7), 3.3 (95% CI: 1.5-7.2), and 7.7 (95% CI: 4.0-14.7), respectively, compared with those with low UCd/UPb. The risk of decrease in eGFR was also higher in subjects with high UCd/UPb than for those with low UCd/UPb (OR = 7.2, 95% CI: 0.8-62.2). Our data demonstrate that Cd and Pb exposure, alone or in combination, are associated with renal impairment. In addition, co-exposure to Pb and Cd propagates the renal tubular dysfunction compared with Cd or Pb exposure alone.

Blood lead and cadmium in age related macular degeneration in a Turkish urban population

PURPOSE

To evaluate the blood lead (Pb) and cadmium (Cd) levels in age related macular degeneration (AMD) in a turkish urban population.

METHODS

Blood Pb and Cd levels of 31 AMD patients and 24 age and gender matched controls with no sign of AMD were measured using dual atomic absorption spectrophotometer system (AAS). History of hypertension, diabetes mellitus, cigarette smoking, myocardial infarction and stroke were obtained from all subjects. Degree of AMD was grade 4 according to the Age-Related Eye Disease Study grading system. Median blood Pb and Cd levels were compared by using Students' t-test.

RESULTS

Demographic properties like smoking status, presence of diabetes mellitus or hypertension, cerebrovascular occlusion history, serum cholesterol and lipid levels were not significantly different between groups except history of ischemic heart disease (3.22% vs 25% in AMD and control groups respectively, p = .022). Overall in AMD group blood Pb level was 2.83 ± 0.15 μg/l and it was 2.63 ± 0.23 μg/l in control group (p = .36). The Cd level was 3.25 ± 0.20 μg/l in AMD group and 3.11 ± 0.25 μg/l in control group (p = .67). The mean Pb (2.38 ± 0.88 μg/l vs 2.91 ± 1.37 μg/l for AMD vs control, p = .61) and Cd levels (3.06 ± 1.34 μg/l vs 3.35 ± 1.26 μg/l for AMD vs control, p = .56) in current and previous smokers with AMD were not significantly different from those of the current and previous smokers in control group.

CONCLUSION

Blood Pb and Cd levels which reflect short term exposure were not significantly different in AMD patients and the control group. The difference was not significant either after involvement of previous or current smoker subjects.

Liver tissue trace element levels in HepB patients and the relationship of these elements with histological injury in the liver and with clinical parameters

AIM

In this study, the relationship of liver tissue trace element concentrations with hepatitis B disease and the effects of several environmental factors were analysed.

METHOD

The liver tissue concentrations of Al, Fe, Cd, Mn, Cr, Cu, Pb, Ni, Zn, Ag, and Co were evaluated in 92 patients with hepatitis B using the Inductively Coupled Plasma - Mass Spectrometry (ICP/MS) method in the analyses. The patients were divided into the following two groups: low-high Ishak histologic activity index (HAI) (0-6: Low Histologic Activity, 7-18: High Histologic Activity) and low-high fibrosis (FS) (Fibrosis 1,1,2 and Fibrosis 3,4,5,6). The metal levels were compared between the groups.

RESULTS

The Cd concentration was found to be statistically higher in the group with low HAI scores (p=0.019). The hepatic Cu concentration was found to be higher in women than in men (p=0.046). The hepatic Fe concentration was found to be higher in the group with increased FS compared to the group with decreased FS (p=0.033). Cd was found to be higher in patients who worked in positions involving exposure to heavy metals and in individuals with an ALT level above 40 IU/L (p=0.008). Several correlations have been found between the hepatic tissue metal levels in our study. In a linear regression analysis, Fe and Zn were found to be correlated with the fibrosis scores (p=<0.001 and p=0.029), and Cu was correlated with HAI (p=0.023). In the linear regression model, Ni (p=0.018) and Cr (p=0.011) were correlated with gender. There was a correlation between the hepatic Fe level and the location where hepatitis B patients were living (village/city) (p=0.001), frequency of fish consumption (p=0.045) and smoking (p=0.018) according to the linear regression analysis. Using a logistic regression analysis, Cr (p=0.029), Ni (p=0.031) and Pb (p=0.027) were found to be correlated with smoking habit, and Zn (p=0.010), Ag (p=0.026), Cd (p=0.007) and Al (p=0.005) were correlated with fish consumption.

CONCLUSION

The liver tissue trace element levels are correlated with disease activity and histologic damage in patients with HepB disease. Additionally, smoking, the environment in which the patient works and the amount of fish consumption affect the accumulation of trace elements in the liver.

Cadmium Concentration in Human Autopsy Tissues

The concentration of cadmium in human tissues obtained on the basis of autopsies of non-poisoned Polish people (n = 150), aged from 1 to 80 years, examined between 1990 and 2010, is presented. The following values were found in wet digested samples by flame atomic absorption spectrometry (FAAS) (mean ± SD, median, and range, μg/g of wet weight): brain 0.020 ± 0.031, 0.084, 0-0.120 (n = 41); stomach 0.148 ± 0.195, 0.084, 0-1.25 (n = 89); small intestine 0.227 ± 0.231, 0.130, 0-0.830 (n = 39); liver 1.54 ± 1.55, 1.01, 0.015-9.65 (n = 99); kidney 16.0 ± 13.2, 14.0, 0.62-61.3 (n = 91); lung 0.304 ± 0.414, 0.130, 0-1.90 (n = 25); and heart 0.137 ± 0.107, 0.140, 0.017-0.250 (n = 4). Additionally, results (n = 13 people, aged from 2 to 83 years, 63 samples) obtained by inductively coupled plasma optical emission spectrometry (ICP OES) between 2010 and 2015 are given. The obtained data on Cd concentration in the human body can be used to estimate the amounts occurring in "healthy" people and those occurring in cases of chronic or acute poisonings with Cd compounds, which are examined for forensic purposes or to assess environmental exposure levels.

Correlation of Cadmium and Magnesium in the Blood and Serum Samples of Smokers and Non-Smokers Chronic Leukemia Patients

It was studied that cancer-causing processes are related with the disproportions of essential and toxic elements in body tissues and fluid. The purpose of the current study was to evaluate the levels of magnesium (Mg) and cadmium (Cd) in serum and blood samples of smokers and nonsmokers who have chronic myeloid (CML) and lymphocytic (CLL) leukemia, age ranged 31-50 years. For comparative study, age-matched smokers and nonsmoker males were chosen as controls/referents. The levels of elements in patient were analyzed before any treatment by atomic absorption spectrophotometer, after microwave assisted acid digestion. The validation of the method was done by using certified reference materials of serum and blood samples. The resulted data indicated that the adult male smokers and nonsmokers have two- to fourfold higher levels of Cd in the blood and sera samples as compared to the referents (p < 0.01), whereas two- to threefold lower levels of Mg was found in blood and serum samples of both types of leukemia patients as related to referent values. The resulted data indicates significant negative correlation among Mg and Cd in leukemia patients and smoker referents. Further studies are needed to clarify the role of these elements in pathogenesis of chronic leukemia.

Low-Dose Cadmium Causes Metabolic and Genetic Dysregulation Associated With Fatty Liver Disease in Mice

Cadmium (Cd) is present in food at low levels and accumulates in humans throughout life because it is not effectively excreted. Cd from smoking or occupational exposure shows adverse effects on health, but the mechanistic effect of Cd at low dietary intake levels is poorly studied. Epidemiology studies found that nonalcoholic fatty liver disease (NAFLD), common in U.S. adults, is associated with Cd burden. In cell studies, we found that environmental low-dose Cd oxidized proteins and stimulated inflammatory signaling. However, little is known about low-dose Cd effects on liver function and associated metabolic pathways in vivo. We investigated effects of low-level Cd exposure on liver gene transcripts, metabolites, and associated metabolic pathways and function after challenging mice with Cd (10 mg/l) by drinking water. Results showed liver Cd in treated mice was similar to adult humans without occupational or smoking exposures and 10-fold higher than control mouse values. Pathway analysis of significantly altered liver genes and metabolites mapped to functional pathways of lipid metabolism, cell death and mitochondrial oxidative phosphorylation. These are well-recognized pathways associated with NAFLD. Cd-treated mice had higher liver enzymes in plasma and a trend toward fat accumulation in liver. To verify low-dose Cd-induced stimulation of cell death pathways, phosphorylation of c-Jun N-terminal kinase (JNK) was examined in cultured hepatic cells. Consistent with mouse liver data, low-dose Cd stimulated JNK activation. Together, the results show that low-dose Cd exposure causes liver function changes consistent with a role in NAFLD and possibly also nonalcoholic steatohepatitis.

Arsenic, cadmium, chromium and nickel in cancerous and healthy tissues from patients with head and neck cancer

Chronic exposure to heavy metals has long been recognized as being capable to increase head and neck cancer incidence among exposed human populations. Head and neck cancer is a significant public health issue in Tunisia. The aim of the present study was to evaluate the concentrations of As, Cd, Cr and Ni in healthy and tumor tissues of head and neck cancer patients. Metal concentrations were determined in tumor and healthy tissues of 101 head and neck cancer patients, using Atomic Absorption Spectrometry. The As, Cd, Cr, and Ni levels in tumor tissues were 3.4, 2.5, 1.3 and 1.5 times higher than those of healthy tissues (p<0.05), respectively. Tumor tissue metal levels were higher in men than in women. As and Cd levels in tumor and healthy tissue samples of patients smokers are significantly higher than those of non-smokers (p<0.05). A strong effect of cumulative smoking as expressed in the number of pack per year, and tumor tissue Cd levels were positively associated with three groups of age (<40, 51-60 and >60 years) in both never-smokers and ever-smokers (<20 and ≥20 pack per year). Healthy tissue Cd levels were negatively associated with age in those three groups of smokers. The highest Cd and Cr concentrations among both workers and non-workers were observed in tumor tissues. The Cd and Cr in tissues of farmers, bricklayers and painters were all significantly higher among the workers as compared with the non-workers group. Tissue metal levels have increased due to smoking and occupational exposure. Heavy metal exposure via tobacco smoking and occupational exposures may increase the risk of head and neck in the Tunisian population.

Diet and nutrients are contributing factors that influence blood cadmium levels

Studies suggested the intake of Cd from diet can be approximately equivalent to that from smoking. Moreover, a mutual metabolic influence between Cd and nutrients has been reported. The purpose of this study was to evaluate the relationship between blood cadmium concentration (BCdC) and food consumption, nutrients intake (Ca, Fe, Zn, vitamin C, and vitamin D), tobacco smoking, and some other variables (age, body mass index, and residence) in 243 adults living in the Italian island of Sardinia (Sassari Province). Specifically, we hypothesized that offal consumption contributes to Cd intakes and blood levels. The BCdC was quantified by graphite furnace atomic absorption spectrometry, and information on personal data was collected through questionnaires. Smoke significantly contributed to the BCdC (P < .001). Nonsmoker subjects who eat offal showed significantly higher BCdC (P = .04). Moreover, slightly higher BCdCs were also observed in nonsmoker subjects who eat rice, fish, and bread. The BCdC positively correlated with age of subjects (r = 0.144; P = .025) and offal daily intake in nonsmokers (r = 0.393; P < .001). The intake of Ca was negatively correlated (r = -0.281; P = .001) with the BCdC in females. The multiple linear regression analysis showed smoking > consumption of offal > body mass index ≈ age as the most important risk factors for the BCdC in the selected population.

Cadmium and other metal levels in autopsy samples from a cadmium-polluted area and non-polluted control areas in Japan

This study was initiated to examine accumulation of cadmium (Cd) and other metals in kidney and liver in autopsy samples and to compare the levels between those in an area with heavy Cd exposure and those in no-polluted areas in Japan. Data on Cd and other metals in kidney (cortex and medulla) and liver in 95 cases (87 women and eight men; the exposed) in a Cd-polluted area and 43 cases (21 women and 22 men; the controls) in non-polluted areas were cited from 15 previous publications to be summarized together with six unpublished cases. Cd levels in kidney cortex and medulla were significantly lower in the exposed (31.5 and 23.8 μg/g wet tissue as GM, respectively) than in the controls (82.7 and 36.4 μg/g, respectively), whereas Cd levels in liver was higher in the exposed (60.2 μg/g) than in the controls (8.1 μg/g). Exposed women had lower Cd in the cortex (29.9 μg/g) and medulla (22.7 μg/g) than exposed men (55.4 and 38.1 μg/g, respectively) as well as in cortex of control women (92.9 μg/g). Comparison with worldwide data other than Japan for non-exposed populations [19.1, 9.3, and 1.3 μg/g in cortex, medulla, and liver, respectively, as the inverse variance-weighted averages (IVWA) of GM values for each of 22 reports] suggests that the levels for the non-exposed Japanese (123.3, 33.5, and 3.9 μg/g as IVWA) tended to be higher than the levels in other countries, possibly reflecting high dietary Cd intake in the past.

Bioelements and mineral matter in human livers from the highly industrialized region of the Upper Silesia Coal Basin (Poland)

Contents of mineral substance, silica, and a range of bioelements and toxic elements (Mg, Na, K, Ca, Ba, Zn, Cr, P Al, Cd, Mn Cu, Ni, Pb, Sr, Fe) in 38 livers of donors from the Upper Silesia Coal Basin (southern Poland) are presented. Elements were determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES) with the exception of silica that was estimated colorimetrically. Concentrations, concentration variability, and correlations between selected liver components determined for the total population are related to donor age, gender, and lesion occurrence. Correlations between particular elements were found using correlation coefficient values and the Fisher transformation. Mineral substance in the livers lies in the range 0.40-5.03 wt%. With increasing donor age, mineral-matter content decreases to a minimum for the 40-60 years of age range. Microbioelement contents show a similar tendency, while microbioelements and toxic elements reach maximum contents in donors aged 60-80 years. All elements show content decreases in livers from the oldest group (>80 years). Silica contents increase with age. Variability of element contents is lowest in the older subpopulations. Livers with lesions show lower element contents and variability. The results are compared to literature data for regions of Poland assumed to be of low pollution and to data from comparable regions in Japan and Hungary. Up to our knowledge, this paper is the first work describing the total contents, as distinct from contents of selected elements, of mineral substance in human livers.

Collection of biological samples in forensic toxicology

Forensic toxicology is the study and practice of the application of toxicology to the purposes of the law. The relevance of any finding is determined, in the first instance, by the nature and integrity of the specimen(s) submitted for analysis. This means that there are several specific challenges to select and collect specimens for ante-mortem and post-mortem toxicology investigation. Post-mortem specimens may be numerous and can endow some special difficulties compared to clinical specimens, namely those resulting from autolytic and putrefactive changes. Storage stability is also an important issue to be considered during the pre-analytic phase, since its consideration should facilitate the assessment of sample quality and the analytical result obtained from that sample. The knowledge on degradation mechanisms and methods to increase storage stability may enable the forensic toxicologist to circumvent possible difficulties. Therefore, advantages and limitations of specimen preservation procedures are thoroughfully discussed in this review. Presently, harmonized protocols for sampling in suspected intoxications would have obvious utility. In the present article an overview is given on sampling procedures for routinely collected specimens as well as on alternative specimens that may provide additional information on the route and timing of exposure to a specific xenobiotic. Last, but not least, a discussion on possible bias that can influence the interpretation of toxicological results is provided. This comprehensive review article is intented as a significant help for forensic toxicologists to accomplish their frequently overwhelming mission.