[Evaluation of potential renal acid load for estimating the health effects of drinking water].

There is a lack of a reliable comprehensive evaluation indicator to access the health effects of drinking water. In recent years, scholars established an indicator to evaluate the comprehensive effect of drinking water on the body's acid-base balance. This indicator came from the potential renal acid load (PRAL) of food and named the potential renal acid load of drinking water. It included several typical anions and cations which are widely found in drinking water. This article reviewed the application, advantages, and disadvantages of PRAL in accessing the effect of drinking water on body acidbase metabolism.

[The relationship between soluble silicate acid in drinking water and food and human health].

Silicon was once considered a biologically inert element, but recent research has shown its value for human health.Soluble silicic acid is the available form of silicon in human body. This paper reviews the absorption, distribution and metabolic characteristics of dietary soluble silicic acid in human body, as well as its relationship with human health.Available data show that it has lots of supporting evidences that dietary soluble silicic acid can prevent osteoporosis, maintain vascular health, improve the symptoms of Alzheimer's disease and multiple sclerosis.Its unique crosslinking ability and antagonism to toxic aluminum play a crucial role. In the early stage of human life, there is a strong demand for silicon, and the level of silicon in the aged is generally reduced, suggesting that pregnant women and old people should pay attention to the intake of soluble silicic acid. It is suggested to strengthen the basic and applied research on dietary soluble silicic acid,and gradually establish the relevant nutrition and hygiene standards.

[The blood lead level and its relationship with behavior in school-age children from rural areas of Chongqing].

Objective: To explore the blood lead level and its relationship with behavior in school-age children from rural areas of Chongqing. Methods: A total of 697 students from grades 3 to 6 in the fall semester of 2014 from 14 rural townships in one district of Chongqing was selected by using the random cluster sampling method. Blood were sampled to analyze the lead level. Neurobehavioral tests were performed to determine their personal cognitive and memory ability. Questionnaires and physical examinations were administered to obtain the information of confounding factors. All students were divided into Q1-Q4 groups according to the quartile of their blood lead level. The relationship between the blood lead level and behavior was analyzed by multivariate logistic regression model and restricted spline regression model. Results: The mean age of 697 students was (10.07±1.36) years old, and the median (interquartile range) of their blood lead level was 44.31 (35.42) µg/L. Multivariate logistic regression model showed that after adjusting for age, gender, body mass index and maternal culture level, compared with Q1 group, the OR (95%CI) values of high digit symbol substitution test (DSST) scores and high overall memory quotient (MQ) scores in Q3 group were 1.65 (1.01-2.70) and 2.10 (1.21-3.62), and the OR (95%CI) value of high long term memory (LTM) scores in Q4 group was 0.53 (0.31-0.92). The results of the restricted spline regression model showed that the dose-response curves between the blood lead level and MQ/LTM test scores were both parabolic (P<0.05). Conclusion: The blood lead level of school-age children from rural areas of Chongqing is the same as that from other areas of China, but slightly higher than that from other areas of Chongqing. Children with higher blood lead level have poor long-term memory ability.

[The association between aflatoxin exposure and primary hepatocellular carcinoma risks: a case-control study in Chongqing].

Objective: To investigate the association between aflatoxin exposure and primary hepatocellular carcinoma (PHC) development. Methods: From December 2013 to May 2016, we selected 214 patients newly diagnosed with PHC as cases, and 214 patients as controls from three hospitals in Chongqing. Cases were confirmed with PHC diagnosis standard. And cases caused by clear reasons such as drug-induced liver injury, alcoholic liver damage, fatty liver and gallstones etiology, were excluded. Controls were included with no cancer and no digestive system disease, and recruited simultaneously with cases. Cases and controls were frequency-matched (1∶1) by same gender and age (±3 years). Peripheral blood and random urine samples were collected and analyzed for serum HBsAg status by biochemistry analyzer, and serum AFB(1)-ALB adduct and urinary AFB(1)-N(7)-GUA adduct by ELISA. Basic information, living habits and history of disease for patients were obtained by questionnaires. We used wilcoxon rank sum test to compare the median of serum AFB(1)-ALB adduct and urinary AFB(1)-N(7)-GUA adduct in cases and controls. Logistic regression analyses were performed to assess risk factors for PHC, and synergism index (S) of aflatoxin with other factors was estimated by the method of Andersson. Results: There was no significant difference in age between PHC cases (50.74±9.67) years and controls (51.15±9.90) years. Logistic regression showed that the odds ratio of HBV infection for PHC development was 46.3 (95% CI: 23.3-88.0). There was a significant difference in median concentrations of serum AFB(1)-ALB adduct (cases vs controls: 146.23 vs 74.42 ng/g albumin, P<0.001), but no difference in median concentrations of urinary AFB(1)-N(7)-GUA adduct was observed (cases vs controls: 0.17 vs 0.14 ng/mg creatinine, P<0.210). The odd ratios for PHC risk after adjustment were 1.9 (95%CI: 1.1-3.4) for AFB(1)-ALB adduct, and 2.1 (95%CI: 1.0-4.2) for AFB(1)-N(7)-GUA adduct. Moreover, we observed a positive interaction of aflatoxin exposure with HBV, alcohol drinking, and diabetes. The S was 4.7 (95%CI: 2.8-7.9), 3.5 (95%CI: 1.0-12.0), and 12.4 (95%CI: 1.8-84.2), respectively for serum AFB(1)-ALB adduct with each of the three factors mentioned, and was 1.9 (95%CI:1.1-3.1), 2.0 (95%CI: 1.1-3.6), and 2.0 (95%CI: 1.1-3.6), respectively for urinary AFB(1)-N(7)-GUA adduct with each of the three factors mentioned. Conclusion: HBV was still the main risk factor, and AFB(1) exposure was also an independent risk factor for PHC in Chongqing. There was a positive interaction of aflatoxin with HBV, alcohol drinking, and diabetes.

Blocking the mitochondrial permeability transition pore with cyclosporine-A can restore cardioprotection of ischemic postconditioning in hypercholesterolemic rat heart.

OBJECTIVE: Ischemic postconditioning (IPO) reduces lethal reperfusion injury under normal conditions, but its effectiveness is blocked by hypercholesterolemia (HC). This study aims to determine whether blocking the mitochondrial permeability transition pore (mPTP) with cyclosporine-A (CsA) can restore cardioprotection of IPO in hypercholesterolemic rat heart. MATERIALS AND METHODS: Isolated rat hearts underwent 30 min global ischemia and 120 min reperfusion. Postconditioning protocol was induced by six cycles of 10s ischemia and 10s reperfusion at the onset of the reperfusion. CsA (0.5 µM or 5 µM) was administered 15 minutes before ischemia. Myocardial infarct size was estimated by triphenyltetrazolium chloride (TTC) staining. Cardiomyocyte apoptosis was assessed by TUNEL staining and creatine kinase-MB (CK-MB) was analyzed from coronary effluent. RESULTS: In normocholesterolemia (NC) groups, infarct size, cardiomyocyte apoptosis rate and release of CK-MB were significantly reduced after IPO. These reductions were completely abolished by HC, as evidenced by a similar infarct size, cardiomyocyte apoptosis rate and release of CK-MB observed between IPO-HC group and control-NC group, but were restored by IPO combinated with CsA treatment. However, CsA treatment alone could not restore cardioprotection in a state of HC. CONCLUSIONS: Ischemic postconditioning, blocked by hypercholesterolemia may due to the excessive opening of the mPTP. Inhibiting of the mPTP with CsA is able to reverse this loss of cardioprotection.

The protective effect of fasudil pretreatment combined with ischemia postconditioning on myocardial ischemia/reperfusion injury in rats.

OBJECTIVE: Ischemic postconditioning (IPO) and pharmacological pretreatment may reduce myocardial necrosis and apoptosis during ischemia/reperfusion. This study aimed to determine the protective effect of fasudil pretreatment combined with IPO on myocardial ischemia/reperfusion injury in rats and explore the possible mechanisms. MATERIALS AND METHODS: The SD rats were induced by intraperitoneal injection of fasudil hydrochloride (1 or 10 mg/kg) 60 min before the initiation of ischemia, while the control rats were given the same volume of saline. The hearts were hung on the Langendorff perfusion apparatus and underwent 30 min global ischemia and 120 min reperfusion. The IPO protocol was induced by six cycles of 10 sec ischemia and 10 sec reperfusion at the onset of reperfusion. The hemodynamic changes were measured, myocardial infarct size was determined by triphenyltetrazolium chloride (TTC) staining, cardiomyocyte apoptosis was detected by TUNEL staining, lactate dehydrogenase (LDH) was analyzed from coronary effluents, phosphorylation of Akt and eNOS, as well as expression of Bcl-2 and Bax were measured by western blotting analysis. RESULTS: The high-dose fasudil (10 mg/kg) pretreatment group and IPO group significantly improved post-ischemia cardiac function, reduced myocardial infarct size, attenuated cardiomyocyte apoptosis, decreased the release of LDH, increased expression of phospho-Akt, phospho-eNOS and Bcl-2, and reduced expression of Bax compared with the control group (p < 0.05). In addition, the high-dose fasudil pretreatment combined with IPO group could further improved post-ischemia cardiac function, reduced myocardial infarct size, attenuated cardiomyocyte apoptosis, decreased the release of LDH, increased expression of phospho-Akt, phospho-eNOS and Bcl-2, and reduced expression of Bax compared with the single treatment groups (p < 0.05). CONCLUSIONS: The combination of high-dose fasudil pretreatment and IPO had a synergistic protective effect on myocardial ischemia/reperfusion injury, which was mediated via upregulating the PI3K/Akt/eNOS pathway, increasing expression of antiapoptotic Bcl-2, and decreasing expression of proapoptotic Bax.

Determination of DNA with cetyltrimethylammonium bromide by the measurement of Resonance Light Scattering.

A simple assay of DNA was developed based on the measurements of enhanced signals of Resonance Light Scattering (RLS) of cetyltrimethylammonium bromide (CTMAB) by DNA. The enhanced RLS signals, measured by simultaneously scanning the excitation and emission monochromators of a common spectrofluorometer with lambda ex = lambda em, was optimized for the DNA assay with CTMAB. On the conditions of pH 2.21 and ionic strength 0.002, the enhanced RLS intensity at 470.0 nm, delta I, was found to be proportional to the concentration of DNA in the range 0-2.5 micrograms/ml if 1.5 x 10(-5) M CTMAB was used. Limits of determination for calf thymus DNA and fish sperm DNA were 4.9 ng/ml and 9.2 ng/ml, respectively. Synthetic samples were determined with the recovery ratio ranging from 93.2% to 105.1%, and the RSD is lower than 2.7%.

Total internal reflected resonance light scattering determination of chlortetracycline in body fluid with the complex cation of chlortetracycline-europium-trioctyl phosphine oxide at the water/tetrachloromethane interface.

A highly selective method of chlortetracycline (CTC) is proposed on the basis of the measurements of total internal reflected resonance light scattering (TMR-RLS) at water/tetrachloromethane (H20/CCl4) interfaces. In the pH range of 7.54-8.14, the interaction of the binary complex of Eu(III)/CTC in the presence of trioctyl phosphine oxide (TOPO) occurs at the H20/CCl4 interface, resulting in greatly enhanced TIR-RLS signals with the maximum peak located at 340 nm. The enhanced TIR-RLS intensity is in proportion to the CTC concentration in the range 0.98 to approximately 20.0 x 10(-7) mol/L. The limit of detection is 9.8 x 10(-9) mol/L. Synthetic samples and body fluid samples including human urine, human serum, and fresh milk were determined with the recovery of 95.4-106.4% and RSD of 2.9-3.9%.

[Inhibitory effects of N-(4-hydroxylphenol) retinamide on transformed human bronchial epithelial cells in vitro and reconstructed human bronchial epithelium in vivo].

Precancerous lesion is one of most important steps in tumorigenesis. It has been shown that retinoids have reliable effects on controlling many kinds of animal tumor and malignant tumor cell lines in vitro, but there is no laboratory report on the biological effect of retinoids on the precancerous lesion of human lung cancer. In this study the methods including of cell serum-free culture, precancerous model of human bronchial epithelium reconstructed in rat trachea/xenotransplanted in nude mice, flowcytometry, immunohistochemistry, TUNEL and pathological observation have been used to study the biological effects of N-(4-hydroxylphenol) retinamide (4-HPR), one new kind of retinoids, on transformed human bronchial epithelial cells in vitro and premalignant human bronchial epithelium in vivo. The results showed that in the study in vitro, the proliferation of transformed human bronchial epithelial cells, the ratio of cells in S phase, and the percentage of cells that positively react to antibody Ki-67 and mpm-2 were inhibited, but apoptotic cells were induced significantly by 4-HPR exposure. At the experiment in vivo, both growth rates and precancerous grades of the reconstructed human bronchial epithelium were reduced, and apoptotic cells were also observed in epithelium after 4-HPR treatment. The results suggested that 4-HPR is one of hopeful chemopreventive medicines to lung cancer.

[Toxicity of chongqing acid fogwater on rabbit alveolar macrophages in vitro].

We collected acid fogwater on a fogday and observed its toxic effects on rabbits' pulmonary alveolar macrophages (AM) in vitro. The fogwater was diluted into 4 concentrations: 1, 1/10, 1/100, and 1/1000 of the original fogwater and the exposure time was 12 hours. The results showed that both the AM's viability and the phagocytic capacity were depressed significantly, but the AM's lysosomal enzyme--acid phosphatase activity was found to be stimulated to increase. All these changes were directly correlated with the degree of pollution of the fogwater. Of these three toxicity indices, the most sensitive one was the change of AM's phagocytic capacity.