Contamination and health risks brought by arsenic, lead and cadmium in a water-soil-plant system nearby a non-ferrous metal mining area.

Heavy metal(loid)s contamination prevails in the water-soil-plant system around non-ferrous metal mining areas. The present study aimed to evaluate the heavy metal(loid)s contamination in Nandan Pb-Zn mining area (Guangxi, China). A total of 36 river water samples, 75 paired paddy soil and rice samples, and 128 paired upland soil and plant samples were collected from this area. The concentrations of arsenic (As), lead (Pb), and cadmium (Cd) in these samples were measured. Results showed that the average water quality indexes (WQIs) at the 12 sampling sites along the main river ranged from 41 to 5008, indicating the water qualities decreasing from "Excellent" to "Undrinkable". The WQIs nearby tailings or industrial park were significantly higher than those at the other sites. 34.0% and 64.5% of soil samples exceeded the risk screening values for As and Cd. The Pb and Cd concentrations in all rice samples exceeded the Chinese food safety limits by 18.7% and 82.7%, respectively. Leafy vegetables had a higher concentration of As, Pb, and Cd than other vegetables, exceeding the maximum permissible limits by 14.1%, 61.2%, and 40.0%, respectively. The biological accumulation coefficient (BAC) of Cd was the highest in rice and lettuce leaves. The hazard quotients (HQs) of As and Cd, indicating non-carcinogenic risks, were 4.15 and 1.76 in adult males, and 3.40 and 1.45 in adult females, all higher than the permitted level (1.0). The carcinogenic probabilities of As and Cd from rice and leafy vegetables consumption were all higher than 1 × 10-4. We conclude that metal(loid)s contamination of the water-soil-plant system has posed great non-carcinogenic and carcinogenic risks to the local population.

Uncovering the characteristics of the gut microbiota in patients with ischemic stroke and hemorrhagic stroke.

This study aimed to explore the gut microbiota characteristics of ischemic and hemorrhagic stroke patients. A case-control study was conducted, and high-throughput sequencing of the V4-V5 region of 16S rRNA was used to analyze the differences in gut microbiota. The results showed that Proteobacteria was significantly increased in the ischemic stroke group compared with the healthy control group, while Fusobacteria was significantly increased in the hemorrhagic stroke group. In the ischemic stroke group, Butyricimonas, Alloprevotella, and Escherichia were significantly more abundant than in the healthy control group. In the hemorrhagic stroke group, Atopobium, Hungatella, Eisenbergiella, Butyricimonas, Odonbacter, Lachnociostridium, Alistipes, Parabacteroides, and Fusobacterium were significantly more abundant than in the healthy control group. Additionally, Alloprevotella, Ruminococcus, and Prevotella were significantly more abundant in the ischemic stroke group than in the hemorrhagic stroke group. The gut microbiota of ischemic and hemorrhagic stroke patients has significant diversity characteristics. These results provide new theoretical basis for exploring the prevention and treatment of different types of stroke through gut microbiota research.

Association of lead and cadmium exposure with kidney stone incidence: A study on the non-occupational population in Nandan of China.

BACKGROUND: Environmental lead (Pb) and cadmium (Cd) pollution has been considered a risk factor in the etiology of kidney stones. However, the association between Pb and Cd exposure and kidney stone incidence has yet to be determined. OBJECTIVES: This study aimed to determine a possible the association between kidney stones with Pb and Cd exposure (alone or combined) in a non-occupational population. METHODS: Pb and Cd contaminations in soil-plant system were determined by flame atomic absorption spectrophotometry. Health risk assessment of dietary Pb or Cd intake from rice and vegetables were calculated. Kidney stones were diagnosed with urinary tract ultrasonography. Urinary cadmium (UCd) and blood lead (BPb) levels were determined by graphite-furnace atomic absorption spectrometry. Multivariate logistic regression models were constructed. RESULTS: The hazard indexes (HI) of Pb and Cd were 7.91 and 7.31. The odds ratio (OR) was 2.83 (95 %CI:1.38-5.77) in males with high BPb (BPb ≥ 100 µg/L), compared with those with low BPb (BPb＜100 µg/L). Compared to those with low BPb and low UCd (BPb＜100 µg/L and UCd＜2 µg/g creatinine), the ORs were 2.58 (95 % CI:1.17-5.70) and 3.43 (95 % CI:1.21-9.16) in females and males with high BPb and high UCd (BPb ≥100 µg/L and UCd ≥2 µg/g creatinine), respectively. The OR was 3.16 (95 % CI:1.26-7.88) in males with high BPb and low UCd (BPb ≥ 100 µg/L and UCd ＜2 µg/g creatinine), compared to those with low BPb and low UCd. CONCLUSIONS: Kidney stones incidence was increased by high Pb exposure in males, and by Pb and Cd co-exposure in males and females.

Risk factors for measles in children younger than age 8 months: A case-control study during an outbreak in Guangxi, China, 2013.

BACKGROUND: Following a period (2009-2012) during which zero measles cases were reported, a measles outbreak occurred in 2013 in Bama County, Guangxi, China, that involved more than 100 children younger than age 8 months. We aimed to identify the pitfalls and risk factors while implementing the control measures. METHODS: An outbreak investigation and a case-control study was conducted among children younger than age 8 months. The serum specimens of the study subjects and their mothers were tested for measles immunoglobulin M and immunoglobulin G. RESULTS: The attack rate was 2.3/1,000 population. The median (interquartile range) age was 18.6 months (7.9-52.8 months). The coverage of 2-dose measles-containing vaccine was only 34%. The case-control study revealed 2 independent risk factors: low education level of main caregiver (odds ratio [OR], 2.86; 95% confidence interval [CI], 1.31-6.22) and visiting a hospital 7-21 days before the date of symptoms onset (OR, 9.84; 95% CI, 4.27-22.67). The population attributable fraction of the latter was 52.8%. The mothers of the cases had nonsignificantly higher levels of immunoglobulin M and were significantly more likely to have protective levels of immunoglobulin G than those of the controls. This suggests a reactive rather than protective role of the antibody to the child's infection. CONCLUSIONS: In a near-elimination but low measles-containing vaccine coverage community, supplementary immunization activities should be emphasized for children and women who are potential future mothers. The minimum age of measles-containing vaccine should be further reduced. Hospital measles transmission must also be strictly prevented.

Glutathione-S-transferases M1 (GSTM1) and GSTT1 genotype, smoking, consumption of alcohol and tea and risk of esophageal and stomach cancers: a case-control study of a high-incidence area in Jiangsu Province, China.

To evaluate interactions between lifestyle factors and glutathione-S-transferases M1 (GSTM1) and GSTT1 genotypes with reference to development of esophageal and stomach cancers, we conducted a case-control study of 141 cases of esophageal cancer, 153 cases of stomach cancer and 223 population-based controls in Huaian City of Jiangsu Province, China. GSTM1 and GSTT1 genotypes were identified by multiplex polymerase chain reaction. The GSTM1 null genotype was associated with an increased odds ratio for esophageal cancer (2.17, 95% confidence interval=1.35-3.50), but not for stomach cancer. A combined effect was also observed between smoking and the GSTM1 null genotype with regard to esophageal risk. Tea drinking was a protective factor for both cancers, its effect being independent of the GSTT1 and GSTM1 genotypes. These findings suggest the GSTM1 polymorphism is involved in the susceptibility to esophageal cancer development, and tea consumption reduces the risk of esophageal and stomach cancers.

Genomic structure of the human beta-PIX gene and its alteration in gastric cancer.

beta-PIX, a newly identified p21-activated kinase (PAK)-interacting exchange factors (PIX), encodes a guanine nucleotide exchange factor for Rho guanosine triphosphatases. Characterization of beta-PIX gene was performed using the BAC Library method. The beta-PIX gene has 17 exons and an A/T polymorphism at the 32nd base upstream of the intron/exon junction of exon 7. The frequencies of genotypes A/T, A/A and T/T were 23.6% (13/55), 72.7% (40/55) and 3.6% (2/55), respectively; these frequencies are in Hardy-Weinberg equilibrium. Two out of 14 informative tumors (14.3%) were shown to have lost their heterozygosity at this locus, but no mutations in the remaining alleles were detected. In addition, we examined the gene-expression profile in another set of 30 gastric samples, but no significant over-expression of either the beta-PIX gene or the alpha-PIX gene was found. Though the beta-PIX gene has been speculated to potentially have tumor-related biological characteristics, the findings of the present study suggest that the involvement of beta-PIX gene in human gastric carcinogenesis is minimal.

Expression profile of EFNB1, EFNB2, two ligands of EPHB2 in human gastric cancer.

PURPOSE: We have previously reported that EPHB2 is overexpressed in gastric cancer; however, the expression profiles of its ligands, EFNB1 and EFNB2, are unknown. This study was designed to investigate the expression of EPHB2 and its ligands, EFNB1 and EFNB2, in human gastric cancer. METHODS: Semi-quantitative RT-PCR using (32)P was performed on human gastric cancer tissues and corresponding normal tissues (29 gastric cancer patients). RESULTS: EPHB2 was more highly expressed in tumor tissues than in normal tissues in 21 out of 29 (72.4%), in gastric cancer patients ( P = 0.01); EFNB1 and EFNB2 were highly expressed in 21 out of 29 (72.4%) ( P = 0.037) and 14 out of 29 (48.3%) patients, respectively. The overexpression of EPHB2 was frequently detected in both well-differentiated adenocarcinoma and poorly differentiated adenocarcinoma [10/13 (76.9%) and 9/14 (64.3%), respectively]. On the other hand, the overexpression of EFNB1 was more frequently detected in poorly differentiated adenocarcinoma than in well-differentiated adenocarcinoma [12/14 (85.7%) and 7/13 (53.8%), respectively. P =0.027]. Elevated levels of EPHB2 and EFNB1 were detected in substantial subsets of early gastric cancers. Genomic alterations to these three genes in gastric cancer specimens were either not found or rarely found except for several rare variations of EPHB2. CONCLUSIONS: These findings suggest that not only the expression of EPHB2, but the expression of its ligand EFNB1 may have some relation with the oncogenesis of gastric cancer.

EPHA2/EFNA1 expression in human gastric cancer.

The erythropoietin-producing hepatocellular (EPH)A2 receptor, tyrosine kinase, is overexpressed and phosphorylated in several types of human tumors and has been associated with malignant transformation. A recent report, however, indicated that stimulation of the EPHA2 receptor ligand, ephrinA1 (EFNA1), inhibits the growth of EPHA2-expressing breast cancer. The authors examined the expression of EPHA2 and EFNA1 using semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) in four gastric cancer cell lines and 49 primary gastric cancer samples, as well as in normal gastric tissue. EPHA2 was more highly expressed in tumor tissue than in normal tissue in 27 cases (55%). EFNA1 was overexpressed in tumor tissue in 28 cases (57%). No significant correlation was detected between the expression levels and histologic features such as tumor size, age, vessel invasion, or lymph node involvement. However, EPHA2 overexpression was more prominent in macroscopic type 3 and 4 tumors than in type 1 or 2 advanced gastric cancer. The authors observed EPHA2 expression in three of the four gastric cancer cell lines (AGS, KATO3, and MKN74) that were examined. In one cell line, TMK1, EPHA2 expression was barely detectable using northern blotting, RT-PCR, and western blotting. In contrast, EFNA1 was detected in all cell lines. In the gastric cancer cell lines that endogenously expressed EPHA2, stimulation with ephrinA1-Fc led to decreased EPHA2 protein expression and increased EPHA2 phosphorylation. Finally, the growth of EPHA2-expressing cells was inhibited by repetitive stimulation with soluble ephrinA1-Fc. Taken together, these findings suggest that EPHA2 and EFNA1 expression may influence the behavior of human gastric cancer.

Negative regulation of EphA2 receptor by Cbl.

The c-Cbl proto-oncogene product Cbl has emerged as a negative regulator of receptor and non-receptor tyrosine kinases, a function dependent on its recently identified ubiquitin ligase activity. Here, we report that EphA2, a member of Eph receptor tyrosine kinases is negatively regulated by Cbl. The negative regulation of EphA2 mediated by Cbl is dependent on the activity of EphA2, as the kinase inactive mutant of EphA2 cannot be regulated by Cbl. Moreover, a point mutation (G306E-Cbl) in TKB region of Cbl that has been reported to abolish Cbl binding to RTKs and non-receptor tyrosine kinases impaired the binding to active EphA2. The dominant negative mutant 70Z-Cbl, which has a 17-amino acids deletion in the N-boundary of the RING finger domain, defuncted negative regulatory function of Cbl to EphA2. These results demonstrate that the TKB domain and RING finger domain of Cbl are essential for this negative regulation.

hOGG1 Ser(326)Cys polymorphism and modification by environmental factors of stomach cancer risk in Chinese.

Oxidative stress is involved in many types of DNA damage, e.g., resulting in 8-hydroxyguanine adducts. Since a human counterpart exists for the yeast gene OGG1 (hOGG1) encoding an enzyme that repairs 8-hydroxyguanine, its polymorphism, Ser(326)Cys, might have potential as a genetic marker for cancer susceptibility. To investigate its association with stomach cancer risk and possible interactions with environmental factors, we conducted a case-control study of 101 stomach cancer cases and 198 controls using PCR-single-strand conformation polymorphism and a questionnaire approach. The proportional distribution of the Cys/Cys alleles did not differ between stomach cancer cases and controls, but subgroup analyses revealed that a frequent drinking habit elevated the odds ratio (OR) for stomach cancer in Cys/Cys compared to Ser/Ser and Ser/Cys carriers. The ORs with frequent consumption of pickled vegetables and meat tended to be higher in Cys/Cys than in Ser/Ser and Ser/Cys carriers, these interactions being on the borderline of statistical significance. Our findings suggest that the hOGG1 Ser(326)Cys polymorphism may alter the impact of some environmental factors on stomach cancer development. For confirmation, an additional study with a larger number of subjects is now required.

Correlation of EPHA2 overexpression with high microvessel count in human primary colorectal cancer.

Evidence suggests that the erythropoietin-producing hepatocellular (EPH) receptor tyrosine kinases (RTKs) and their ephrin (EFN) ligands are involved in human carcinogenesis. Expression of two of them, EFNA1 ligand and its receptor, EPHA2, has been proposed to contribute to tumor-induced neovascularization. Colorectal cancers were examined for expressions of EPHA2 and its ligand EFNA1 by semi-quantitative RT-PCR, and double-immunostained for EPHA2 and CD34. Microvessels in the tumors were counted. Double-staining was also performed in 25 cases of adenoma with focal cancer for comparison. Trends of overexpression of both EPHA2 and EFNA1 was found in tumor tissue compared to the corresponding normal tissue in the same specimen [22/37 (59.5%) and 25/37 (67.5%), respectively; P = 0.100 for EPHA2 and P = 0.009 for EFNA1]. Overexpression of EPHA2 and EFNA1 was noted more frequently in the early stage than in the late stage [EPHA2, 15/21 (71.4%) vs. 7/16 (43.8%), P = 0.007; EFNA1, 15/21 (71.4%) vs. 10/16 (62.5%), P = 0.007]. Both EPHA2 and EFNA1 were more frequently overexpressed in smaller tumors (less than 5 cm) than in larger tumors [EPHA2, 15/21 (71.4%) vs. 7/16 (43.8%), P = 0.017; EFNA1, 16/21 (76.2%) vs. 8/16 (50%), P = 0.001]. Tumors less than 5 cm in diameter and in stages I and II were significantly more likely to overexpress EPHA2 and EFNA1 (P = 0.001 for EPHA2, P = 0.001 for EFNA1). Microvessel counts (MVCs) after immunostaining for CD34 were significantly correlated (r = 0.343, P = 0.037) with overexpression of EPHA2. EPHA2-expressing focal cancer also surrounded microvessels in adenomas with focal cancers. These findings suggest an involvement of EPHA2 in colon carcinogenesis, mainly in stages I and II, and probably through their effect on microvessel induction.