Study on environmental etiology of high incidence areas of liver cancer in China

Cost Estimations of Water Pollution for the Adoption of Suitable Water Treatment Technology

This study analyzed the cost implications of using suitable technologies and the cost of inaction when addressing water pollution. This was achieved by developing three main models for the costs (model one) and benefits (model two and model three). The first model accounts for the operational costs of adopting suitable technologies, namely the use of diatomaceous earth for textile wastewater treatment. The second model analyzed the cost of inaction through analyzing the cost of treatment for water pollution-related diseases for the affected population. The occurrence and cost of treatment for three diseases, namely diarrhea, amoebiasis and bacterial infection, were used as indicators of water pollution in the area. The third model included the contingent valuation method (CVM) data on the willingness to pay for environmental restoration of the surveyed population. The benefit–cost ratio (BCR) of the resulting data from the three models were used to highlight the economic viability of the proposed project. A BCR of (0.67) for the cost of the proposed project versus the benefits of the project on human health using data from one hospital was obtained. There is a high possibility that the real BCR would increase if more data from other hospitals or other diseases were included. The results imply that the use of D.E can be considered a good candidate for treating wastewater. To thoroughly discuss the BCR of treating wastewater from one factory, the BCR of the proposed restoration project along River Sosiani, and the value of using DE as suitable technology, more studies are needed to evaluate the unaccounted costs and benefits for accurate economic estimations of the proposed project. The outcome of the study is a framework of numbers and figures that can be presented to decision makers and policy makers as critical information when making decisions.

Monitoring the Landscape Pattern and Characteristics of Non-Point Source Pollution in a Mountainous River Basin

This study aimed to assess the relationship between the landscape patterns and non-point source (NPS) pollution distribution in Qixia County, China. The sub-basin classification was conducted based on a digital elevation model and Landsat8 satellite images. Water samples were collected from each sub-basin, andtheir water quality during the wet and dry seasons was estimated. The correlation between the landscape indices and water pollution indicators was determined by Pearson analysis. The location-weighted landscape contrast index (LWLCI) was calculated based on the "source-sink" theory. Qixia was further divided into five sections based on the LWLCI score to illustrate the potential risk of NPS pollution. The results showed that the water quality in Qixia County was generally good. Cultivated land, orchards, construction areas, and unused land were positively correlated with the water pollution index and weredesignated as the "source" landscape categories, while forests, grasslands, and water bodies, which were negatively correlated with water pollution, were the "sink" landscapes; the LWCI was high in 36.94% of the study area. In these areas, measures such as increasing vegetation buffer zones are necessary to decrease the sediment and nutrient loads carried by precipitation.

Cancer incidence in urban Shanghai, 1973-2010: an updated trend and age-period-cohort effects

Background

To provide a comprehensive overview of temporal trends in cancer incidence during 1973–2010 in urban Shanghai.

Methods

The estimated annual percent changes (EAPCs) for the whole period and for the time segments in age-standardized incidence rates (ASR) were evaluated with Joinpoint analysis. Age-period-cohort (APC) models were modeled to examine the effects of age, period and birth cohort on cancer incidence.

Results

The overall ASR decreased slightly and significantly in males (EAPC of −0.41) but increased significantly in females (EAPC of 0.57) during 1973–2010 in urban Shanghai. The incidence trend was not linear and varied by time segments. During the most recent 10 years (2001–2010), the ASR in males decreased by 1.65 % per year and stabilized in females. Incidence rates continued to decline during 1973–2010 for esophagus, stomach, and liver cancer in both sexes, as well as male lung cancer and cervix cancer. It should be noted that it was the first time to document a significant decline in lung cancer incidence among males during 1973–2010 with EAPC of −0.58 %, and a notable upward for cervix cancer since 1996 with EAPC of 8.94 %. Unfavorable trends in incidence were observed for the most common cancer sites in the 38 years period: colorectum, gallbladder & biliary tract, pancreas, kidney, bladder, brain & central nervous system (CNS), thyroid, non-Hodgkin’s lymphoma (NHL), prostate, female breast, corpus uteri, and ovary. APC analysis showed age, period and birth cohort yielded different effects by cancer sites.

Conclusions

The observed trends primarily reflect dramatic changes in socioeconomic development and lifestyles in urban Shanghai over the past four decades.

RESISTIN EFFECT ON TELOMERASE GENE EXPRESSION IN GASTRIC CANCER CELL LINE AGS

Background

Resistin, as an adipokine, has been shown to be increased in serum plasma of gastric cancer patients and suggested to be a major factor in gastric carcinogenesis. However, it is still not clear how Resistin influences gastric cancer progression. The aim of this study was to evaluate Resistin effect on cell proliferation and expression of telomerase gene in gastric cancer cell line (AGS).

Methods

In this study, the proliferating activity of AGS cells stimulated with Resistin was also evaluated by using 2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide (XTT) assay and trypan blue staining method. To investigate telomerase gene expression affected by Resistin, total RNA was extracted, cDNA was synthesized and expression of hTERT mRNA was carried out by real-time reverse transcription polymerase chain reaction.

Results

Exogenous Resistin has induced gastric cancer cells proliferation in a dose-dependent manner and could improve cell viability. Also the expression of Human Telomerase Reverse Transcriptase (hTERT) was upregulated in 24 hours, after Resistin treatment.

Conclusions

This study has shown Resistin induces exogenously gastric cancer cell proliferation and increases hTERT gene expression. These findings may clarify the role of Resistin in gastric carcinogenesis. Therefore blocking Resistin signaling and limiting its secretion may be valuable for the treatment of gastric cancer.

Geochemical environment and health problems in China

China is a very large developing country covering vast territories and having a complex natural environment. It has an enormous population and numerous endemic diseases. The total population of China is 14 x 10(8) of which 3 x 10(3) live in endemic disease-affected areas and 0.48 x 10(3) suffer from these diseases. The distribution of the endemic diseases has obvious geographical characteristics. Among the most harmful and widely distributed of the endemic diseases are Kaschin-Beck disease, Keshan disease, iodine deficiency, endemic fluorosis and hepatic carcinoma. The geographical environments have a close relationship to endemic diseases and are influenced by climate, geology, landform, soil, food and drinking water. Drinking water is the key issue, since polluted water, or water lacking in or having an excess of certain minerals and elements, as well as water containing certain organic components, has been shown to be harmful to human health. Research has shown that some diseases can be reduced or eliminated by paying attention to the way drinking water is obtained, as well as by improving the nutritional values of the food by eliminating negative components. Fifty years of research has already gone into this subject and there is still much research to be done. This paper puts forth a model of health problems related to geographical environment and the importance of continued research in this field.

Maxizyme-mediated specific inhibition on mutant-type p53 in vitro

AIM: To evaluate the specific inhibition of maxizyme directing against mutant-type p53 gene (mtp53) at codon 249 in exon 7 (AGG→AGT) in vitro.

METHODS: Two different monomers of anti-mtp53 maxizyme (maxizyme right MzR, maxizyme left MzL) and control mutant maxizyme (G⁵→A⁵) were designed by computer and cloned into vector pBSKU6 (pBSKU6MzR, pBSKU6MzL). After being sequenced, the restrictive endonuclease site in pBSKU6MzR was changed by PCR and then U6MzR was inserted into pBSKU6MzL, the recombinant vector was named pU6Mz and pU6asMz (mutant maxizyme). Mtp53 and wild-type p53 (wtp53) gene fragments were cloned into pGEM-T vector under the T7 promoter control. The ³²p-labeled mtp53 transcript was the target mRNA. Cold maxizyme transcripts were incubated with ³²p-labeled target RNA in vitro and radioautographed after denaturing polyacrylamide gel electrophoresis.

RESULTS: In cell-free systems, pU6Mz showed a specific cleavage activity against target mRNA at 37 °C and 25 mM MgCL₂. The cleavage efficiency of pU6Mz was 42%, while pU6asMz had no inhibitory effect. Wtp53 was not cleaved by pU6Mz either.

CONCLUSION: pU6Mz had a specific catalytic activity against mtp53 in cell-free system. These lay a good fundation for studying the effects of anti-mtp53 maxizyme in HCC cell lines. The results suggest that maxizyme may be a promising alternative approach for treating hepatocellular carcinoma containing mtp53.

Signal transduction of gap junctional genes, connexin32, connexin43 in human hepatocarcinogenesis

AIM

To investigate gap junctional intercellular communication (GJIC) in hepatocellular carcinoma cell lines, and signal transduction mechanism of gap junction genes connexin32(cx32),connexin43(cx43) in human hepatocarcinogenesis.

METHODS

Scarped loading and dye transfer (SLDT) was employed with Lucifer Yellow (LY) to detect GJIC function in hepatocellular carcinoma cell lines HHCC, SMMC-7721 and normal control liver cell line QZG. After Fluo-3AM loading, laser scanning confocal microscope (LSCM) was used to measure concentrations of intracellular calcium (Ca(2+))i in the cells. The phosphorylation on tyrosine of connexin proteins was examined by immunoblot.

RESULTS

SLDT showed that ability of GJIC function was higher in QZG cell than that in HHCC and SMMC-7721 cell lines. By laser scanning confocal microscopy, concentrations of intracellular free calcium (Ca(2+))i was much higher in QZG cell line (108.37 nmol/L) than those in HHCC (35.13 nmol/L) and SMMC-7721 (47.08 nmol/L) cells. Western blot suggested that only QZG cells had unphosphorylated tyrosine in Cx32 protein of 32 ku and Cx43 protein of 43 ku; SMMC-7721 cells showed phosphorylated tyrosine Cx43 protein.

CONCLUSION

The results indicated that carcinogenesis and development of human hepatocellular carcinoma related with the abnormal expression of cx genes and disorder of its signal transduction pathway, such as decrease of (Ca(2+))i, post-translation phosphorylation on tyrosine of Cx proteins which led to a dramatic disruption of GJIC.

The analysis of γ-glutamyl transpeptidase gene in different type liver tissues

AIM: To probe the value of γ-glutamyl transpeptidase (GGT) messenger RNA in monitoring canceration of liver cells and for early diagnosis of hepatocellular carcinoma (HCC), by researching the types of GGT messenger RNA (GGTmRNA) in liver tissues and peripheral blood of different hepatopathy.

METHODS: The three types of GGTmRNA (A, B, C) in liver tissues and peripheral blood from the patients with HCC, noncancerous hepatopathy, hepatic benign tumor, secondary carcinoma of liver, and healthy persons were detected by reverse-transcription polymerase chain reaction (RT-PCR).

RESULTS: (1) In normal liver tissues, type A was predominantly found (100.00%), type B was not found, type C was found occasionally (25.00%); (2) The distribution of types of GGTmRNA in liver tissues with acute hepatitis, chronic hepatitis, cirrhosis, alcoholic hepatopathy was similar as in normal liver tissues (P > 0.05), but type B was found in 3 of 18 patients with chronic hepatitis (16.67%), and also in 3 of 11 patients with cirrhosis (27.27%); (3) There was no significant difference of types of GGTmRNA between liver tissues with hepatic benign tumor, secondary carcinoma of liver and normal liver tissues (P > 0.05); (4) Type B was predominant in cancerous tissues with HCC (87.5%), the prevalence of type B in cancerous tissues was significantly higher than that in normal liver tissues (0/12) (P < 0.05), but the prevalence of type A in cancerous tissues (46.88%) was significantly lower than that in normal liver tissues (100.00%) (P < 0.05), and the prevalence of type C (6.25%) in cancerous was the same as that in normal liver tissues (25.00%) (P > 0.05). In noncancerous tissues of livers with HCC, the main types were type A and type B, the prevalence of type A (85.71%, 90.48%) and type C (14.29%, 9.52%) in noncancerous tissues of liver with HCC was similar as that in normal liver tissues (A: 100.00%; C: 25.00%) (P > 0.05), but the prevalence of type B (80.95%, 76.19%) in noncancerous tissues of livers with HCC was significantly higher than that in normal liver tissues (0/12) (P < 0.05); (5) The prevalence of type B (37.5%) in peripheral blood with HCC was higher than that in normal person (0/12) (P < 0.05). In peripheral blood, type B was found in 4 of 11 cases of HCC with serum AFP negative.

CONCLUSION: The shift of types of GGTmRNA from A to B in liver tissues may be closely related to the development of HCC, and the analysis of GGT gene may provide a useful tool for early diagnosis of HCC.

Preparation of monoclonal antibody against apoptosis-associated antigens of hepatoma cells by subtractive immunization

AIM: To elucidate the expression of the apoptosis-associated molecules in human primary hepatocellular carcinoma (HCC) cells, and prepare the monoclonal antibodies (mAb) against the apoptosis-associated antigens of HCC cells.

METHODS: Human HCC cell line HCC-9204 cells were induced apoptosis with 60 mL•L^-1 ethanol for 6 h and their morphological changes were observed by transmission electron microscope. The cell DNA fragmentations were detected by Terminal Deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay, and the cell DNA contents by flow cytometry. Ten mice were immunized with ethanol-induced apoptotic HCC-9204 cells with the method of subtractive immunization, while the other 10 mice used as the control were immunized by the routine procedures. The tail blood of all the mice were prepared after the last immunization, and the produced antibodies were determined by the immunocytochemical ABC staining. The splenic cells of the mice whose tail blood sera-HCC-9204 cells serum reactions were most different between the apoptotic and the non-apoptotic were prepared and fused with the mouse myeloma cell line SP2/0 cells. The positive antibodies were selected by ELISA assay. The fusion rates of hybridoma cells and the producing rates of antibodies were calculated. The fused cells that secreted candidate objective antibody were cloned continually with the of limited dilution method, and then selected and analyzed further by the immunocytochemical ABC staining. The chromosomes of the cloned hybridoma cells that secreted objective mAb and the mAb immunoglobulin (Ig) subtype of the prepared mAb were also determined. The molecular mass of the mAb associated antigen was analyzed by Western blot assay.

RESULTS: HCC-9204 cells treated with 60 mL•L^-1 ethanol for 6 h, manifested obvious apoptotic morphological changes, the majority of the cells were TUNEL-positive, and the sub-G1 apoptotic peak was evident. There were 2 mice in the experimental group whose tail blood serum reacted strongly with the apoptotic HCC-9204 cells, but weakly with their non-apoptotic counterparts. In the fusion rates of hybridoma cells as well as the producing rates of the antibody deseribed above, there did not show significant difference between the experimental and the control group, but weakly with non-apoptotic HCC-9204. However, the total producing rate of antibodies in the experimental group was significantly lower compared with the control (P < 0.01), and so was the producing rate of the antibodies which reacted strongly with both apoptotic and non-apoptotic HCC-9204 cells (P < 0.01). After cloned continually for several times the cell that produce mAb which reacted strongly with the nuclei of ethanol-induced apoptotic HCC-9204 cells, but very weakly with that of non-apoptotic cells was selected out. Chromosome analysis revealed that the selected cell was with the universal characteristics of the monoclonal hybridoma cells which secreted mAb, and the Ig subtype of the prepared mAb was IgG1. The molecular mass of this mAb associated antigen of was about 75 ku.

CONCLUSION: Subtractive immunization is a useful method to prepare the mAb against the apoptosis-associated antigens of cells. The expression of some molecules increases to some extent in HCC-9204 cells in the process of apoptosis induced by low-concentration ethanol. The mAb that may be against ethanol-induced apoptosis-associated antigens of HCC cells was successfully prepared and primarily identified.

Ultrasonic aspiration hepatectomy for 136 patients with hepatocellular carcinoma

AIM: To study the operative injury, post-operative complications, the hospitalization time, the post-operative survival rate of ultrasonic aspiration hepatectomy with a domestic new type of ultrasonic surgical device in comparison with that of conventional techniques of hepatectomy.

METHODS: A total 136 patients with hepatocellular carcinoma (HCC, including 12 patients in 1991 and 124 consecutive patients from July 1995 to December 2000) underwent ultrasonic aspiration in liver resection (group T) and 179 HCC patients received conventional hepatectomy during the corresponding period (group C). The results of the two groups were compared statistically.

RESULTS: There was no significant difference in the mean operation time between group T (152 ± 11 min) and C (144 ± 11 min). No operation or hospital death occurred in both groups. In group T, the mean volumes of bleeding (463 ± 15 mL) and blood transfusion (381 ± 12 mL) were markedly less than those in group C (557 ± 20 mL, and 507 ± 18 mL, respectively, P < 0.05). The mean hospitalization time of group T (8.9 ± 0.6 d) was markedly shorter than that of group C (11.7 d ± 0.6 d) (P < 0.05). The incidence of complications in group T was markedly lower than in group C, post-operative jaundice occurred in 4/136 and 31/179, respectively (P < 0.05), liver failure in 0/136 and 2/179, cholorrhea in 0/136 and 6/179, hydrothorax in 21/136 and 39/179 (P < 0.05), ascices in 9/136 and 54/179, respectively (P < 0.05). There was no significant difference in the 1-year survival rate between the two groups (P > 0.05), while the 3-year survival rate of group T (64.2%) increased markedly as compared with that of group C (55.7%) (P < 0.01).

CONCLUSION: The ultrasonic aspiration hepatectomy with a domestic new type of ultrasonic surgical device could evidently reduce the operative injury and post-operative complications, shorten the hospitalization time and prolong the survivals of HCC patients.

Anti-hepatoma activity of resveratrol in vitro

AIM: To study the anti-tumor effect of resveratrol alone and the synergistic effects of resveratrol with 5-FU on the growth of H22 cells line in vitro

METHODS: The number of cells was measured by MTT method,the morphological changes of H₂₂ cells were investigated under microscopy and electron microscopyq.

RESULTS: Resveratrol inhibited the growth of hepatoma cells line H₂₂ in a dose- and time-dependent manner. IC₅₀ of the resveratrol on H₂₂ cells was 6.57 mg·L^-1. The synergistic anti-tumor effects of resveratrol with 5-FU increased to a greater extent than for H22 cells treated with 5-FU alone (70.2% vs 28.4%)(P < 0.05). Under microscope and electron microscope, characteristics of apoptosis such as typical apoptotic bodies were commonly found in tumor cells in the drug-treated groups.

CONCLUSION: Resveratrol can suppresses the growth of H₂₂ cells in vitro, its anti-tumor activity may occur through the induction of apoptosis.

Expression of gap junction genes connexin32 and connexin43 mRNAs and proteins, and their role in hepatocarcinogenesis

AIM

To investigate the relationship between hepatocarcinogenesis and the expression of connexin32 (cx32), connexin43 (cx43) mRNAs and proteins in vitro.

METHODS

Gap junction genes cx32 and cx43 mRNA in hepatocellular carcinoma cell lines HHCC, SMMC-7721 and normal liver cell line QZG were detected by in situ hybridization (ISH) with digoxin-labeled cx32, and cx43 cDNA probes. Expression of Cx32 and Cx43 proteins in the cell lines was revealed by indirect immuno-fluorescence and flow cytometry (FCM).

RESULTS

Blue positive hybridization signals of cx32 and cx43 mRNAs detected by ISH with cx32 and cx43 cDNA probes respectively were located in cytoplasm of cells of HHCC, SMMC-7721 and QZG. No significant difference of either cx32 mRNA or cx43 mRNA was tested among HHCC, SMMC-7721 and QZG (P=2.673, HHCC vs QZG; P=1.375, SMMC-7721 vs QZG). FCM assay showed that the positive rates of Cx32 protein in HHCC, SMMC-7721 and QZG were 0.7%, 1.7% and 99.0%, and the positive rates of Cx43 protein in HHCC, SMMC-7721 and QZG were 7.3%, 26.5% and 99.1% respectively. Significant differences of both Cx32 and Cx43 protein expression existed between hepatocellular carcinoma cell lines and normal liver cell line (P=0.0069, HHCC vs QZG; P=0.0087, SMMC-7721 vs QZG). Moreover, the fluorescent intensities of Cx32 and Cx43 proteins in HHCC, SMMC-7721 were lower than that in QZG.

CONCLUSIONS

Hepatocellular carcinoma cell lines HHCC and SMMC-7721 exhibited lower positive rates and fluorescent intensities of Cx32, Cx43 proteins compared with that of normal liver cell line QZG. It is suggested that lower expression of both Cx32 and Cx43 proteins in hepatocellular carcinoma cells could play pivotal roles in the hepatocarcinogenesis. Besides, genetic defects of cx32 and cx43 in post-translational processing should be considered.

Safe upper limit of intermittent hepatic inflow occlusion for liver resection in cirrhotic rats

AIM: To evaluate the effects of varying ischemic durations on cirrhotic liver and to determine the safe upper limit of repeated intermittent hepatic inflow occlusion.

METHODS: Hepatic ischemia in cirrhotic rats was induced by clamping the common pedicle of left and median lobes after non-ischemic lobes resection. The cirrhotic rats were divided into six groups according to the duration and form of vascular clamping: sham occlusion (SO), intermittent occlusion for 10 (IO-10), 15 (IO-15), 20 (IO-20) and 30 (IO-30) minutes with 5 minutes of reflow and continuous occlusion for 60 minutes (CO-60). All animals received a total duration of 60 minutes of hepatic inflow occlusion. Liver viability was investigated in relation of hepatic adenylate energy charge (EC). Triphenyltetrazollum chloride (TTC) reduction activities were assayed to qualitatively evaluate the degree of irreversible hepatocellular injury. The biochemical and morphological changes were also assessed and a 7-day mortality was observed.

RESULTS: At 60 min after reperfusion following a total of 60 min of hepatic inflow occlusion, EC values in IO-10 (0.749 ± 0.012) and IO-15 (0.699 ± 0.002) groups were rapidly restored to that in SO group (0.748 ± 0.016), TTC reduction activities remained in high levels (0.144 ± 0.002 mg/mg protein, 0.139 ± 0.003 mg/mg protein and 0.121 ± 0.003 mg/mg protein in SO, IO-10 and IO-15 groups, respectively). But in IO-20 and IO-30 groups, EC levels were partly restored (0.457 ± 0.023 and 0.534 ± 0.027) accompanying with a significantly decreased TTC reduction activities (0.070 ± 0.005 mg/mg protein and 0.061 ± 0.003 mg/mg protein). No recovery in EC values (0.228 ± 0.004) and a progressive decrease in TTC reduction activities (0.033 ± 0.002 mg/mg protein) were shown in CO-60 group. Although not significantly different, the activities of the serum aspartate aminotransferase (AST) on the third postoperative day (POD₃) and P OD₇ and of the serum alanine aminotransferase (ALT) on POD₃ in CO-60 group remained higher than that in intermittent occlusion groups. Moreover, a 60% animal mortality rate and more severe morphological alterations were also shown in CO-60 group.

CONCLUSION: Hepatic inflow occlusion during 60 min for liver resection in cirrhotic rats resulted in less hepatocellular injury when occlusion was intermittent rather than continuous. Each period of 15 minutes was the safe upper limit of repeated intermittent vascular occlusion that the cirrhotic liver could tolerate without undergoing irreversible hepatocellular injury.