Geographical distribution of risk factors and incidence of invasive cervical cancer in south east China.
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Carcinoma, Squamous Cell↗
Biomedical subjects
S Z Yu
Publications and source records attributed to S Z Yu.
Green-tea consumption and risk of stomach cancer: a population-based case-control study in Shanghai, China.
The effect of drinking Chinese green tea on the risk of stomach cancer was evaluated in a population-based case-control study conducted in Shanghai, China, from October 1991 to December 1993. Eligible cases were incident cases of primary stomach cancer diagnosed during the study period among residents of Hongkou district and Nanhui county aged under 80 years. Controls were selected from the same street or commune where the case resided and were matched to the cases on age (within three years) and gender. A total of 711 cases and 711 matched controls, more than 90 percent of the eligible subjects, completed the interview. Information was obtained on the types of tea used, age when habitual tea drinking started, frequency of new batches of tea leaves used per day, number of cups brewed from each batch, total duration of drinking for each batch, strength and temperature of the tea consumed. Statistical analysis was based on modelling through conditional logistic regression. After adjusting for age, gender, place of residence, education, birthplace, alcohol consumption, and cigarette smoking, the odds ratio (OR) comparing drinkers of green tea with nondrinkers was 0.71 (95 percent confidence interval = 0.54-0.93). The adjusted OR decreased with increasing number of new batches of the green tea consumed each day (P value trend = 0.006). With the largest series of stomach cancer cases to date, this study found green-tea consumption associated with lower risk of stomach cancer. Among drinkers of green tea, the risk of stomach cancer did not depend on the age when habitual green-tea drinking started. Green tea may disrupt gastric carcinogenesis at both the intermediate and the late stages.
Adult↗
Trichomonas vaginalis and cervical cancer. A prospective study in China.
The relationship between Trichomonas vaginalis infection and cervical cancer was investigated prospectively in a cohort of 16,797 women aged 25 years or more who were followed from 1974 to 1985 within the framework of a cervical screening program in Jingan, China. Personal interviews were conducted by trained interviewers when the women first entered the screening program. At initial screening, 421 (2.51%) women had a positive cytologic diagnosis of T. vaginalis infection. Ninety-nine incident cases of pathologically confirmed squamous cell carcinoma were identified from the cohort, with a total of 140,018 person-years of observation. T. vaginalis infection was found to contribute to the risk of cervical cancer, as determined by crude estimates and after adjustment for potential confounding effects. In a multiple proportional hazards model, the relative risk for cervical cancer was 3.3 (95% confidence interval: 1.5 to 7.4) among women with T. vaginalis infection. Furthermore, in the multivariate analysis, increased risk of cervical cancer was associated with the following factors: number of extramarital sexual partners of both the subjects and their spouses, cigarette smoking, and irregular menstruation. Having a large number of negative Pap smears was associated with lower risk. This study suggests that there might be an association between T. vaginalis infection and the risk of cervical cancer, but only 4 to 5% of cervical cancer in Chinese women may be attributable to T. vaginalis infection.
Adult↗
[The prospective research of risk factors of primary liver cancer in Nanhui County, Shanghai].
Based on a prospective study including a population size of eighty thousand in Nanhui County, the risk factors of primary liver cancer in Nanhui County were found as follows: history of hepatitis (OR 1.03, 95%CL 1.02-1.04), the length of drinking pond & ditch water (OR 1.16, 95% CL 1.02-1.32) and the length of drinking river water (OR 1.25, 95% CL 1.09-1.43). The length of drinking shallow well water (OR 0.65, 95% CL 0.59-0.73) and deep well water (including tap water, OR 0.20, 95% CL 0.16-0.25) seemed to be the protective factors of PLC. These data are useful for PLC prevention and to identify the high-risk individuals in Nanhui County.
Adult↗
Spectrum of liver disease and duck hepatitis B virus infection in a large series of Chinese ducks with hepatocellular carcinoma.
The striking difference in the geographical distribution of liver cancer in ducks raised the question of whether duck hepatitis B virus (DHBV), like mammalian hepadnaviruses, could be an oncogenic agent. Hepatocellular carcinomas (HCCs) have been found only in domestic ducks in Qidong, China, where hepatitis B virus infection and aflatoxin B1 (AFB1) are both risk factors and where a high frequency of human HCCs has been reported. To date, the study of liver pathology occurring in Chinese ducks has been hampered by the small number of samples available. We describe here a series of 59 Chinese brown duck livers that were collected in Qidong more than 20 years ago and formalin fixed. Thirty-six HCCs, which ranged from well-differentiated trabecular to highly anaplastic type, were identified in relatively young ducks (average age, 3.3 years). Several unique features not previously reported, such as tumor giant cells, tumor necrosis, tumor thrombi in blood vessels, and inactive cirrhosis, were observed. Bile ductule proliferation, known to be a prominent feature of AFB1 exposure in ducks, was present in 86% of livers. Using polymerase chain reaction (PCR) and two primer pairs, located within conserved portions of the DHBV S and C genes, we demonstrated the presence of DHBV DNA in 23 of 34 HCCs analyzed (68%). The spectrum of liver pathology that we report in brown ducks from Qidong was never observed in Pekin ducks of the same age chronically infected with DHBV and followed under controlled conditions outside China, suggesting that causative factors other than virus infection may be involved in duck liver carcinogenesis observed in this area.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Duck hepatitis B virus infection, aflatoxin B1 and liver cancer in domestic Chinese ducks.
The oncogenicity of Duck hepatitis B virus (DHBV) is unclear since hepatocellular carcinomas (HCCs) have been reported only in domestic ducks in Qidong, an area of China where hepatitis B virus (HBV) and aflatoxin B1 (AFB1) are risk factors for liver cancer in man. In order to better define the association between DHBV infection, AFB1 and HCC we analysed a series of 16 duck liver samples collected from local farms in Qidong. HCC was found in eight and cirrhosis in one of these samples. Furthermore bile duct proliferation, characteristic of AFB1 exposure in ducks and other animal species, was found in these ducks. Integration of DHBV DNA into cellular DNA was observed in only one out of four DHBV positive HCCs, indicating that viral integration is not prerequisite for tumour development. In four remaining HCCs the polymerase chain reaction (PCR) failed to show any DHBV DNA suggesting that liver tumours do occur in polymerase chain reaction (PCR) failed to show any DHBV DNA suggesting that liver tumours do occur in these ducks in the absence of DHBV infection. In addition, AFB1-DNA adducts were detected by hplc-immunoassay in one such DHBV-negative tumour. In summary we demonstrate that risk factors other than DHBV, including AFB1 exposure, may be important in duck liver carcinogenesis in Qidong.
Aflatoxin B1↗
[A study on HLA-Dr expression of brain tumor cells and mononuclear cell subsets infiltrating in these tumors].
Fourty-four primary brain tumors were studied by immunohistochemistry. 29 (67.2%) expressed HLA-Dr. The incidence and number of tumor cells positive for HLA-Dr correlated with the histological type of brain tumor and increased with the degree of malignancy. The mononuclear cells infiltrating in these tumors were mostly CD45ROT cells and macrophages. The former consisted mainly of CD4 and CD8 subsets. The numbers of CD45RO+ and CD8+ T cells in HLA-Dr-group were more than any of the HLA-Dr+, +2, +3 groups. The numbers of CD4 subset and macrophages were not affected by the level of HLA-Dr expression. These results suggest that the HLA-Dr expressed by brain tumor cells selectively inhibit CD8 subset which participates in immunoreaction against brain tumors in situ.
Adolescent↗
[Risk analysis of combination effects of risk factors for primary liver cancer].
Combination effects of major risk factors for primary liver cancer (PLC) was evaluated by generalized relative risk model to examine the adequacy of the multiplicative structure for describing the effects of them and to estimate their relative risk (RR) and population attributable risk (PAR). The results suggested combination effects of hepatitis B virus (HBV) infection and drinking pond-ditch water tended to be multiplicative, and that of aflatoxin B1 (AFB1) contamination and HBV infection and drinking pond-ditch water to be additive. The relative importance of these factors of PLC based on their RR and PAR was HBV infection, drinking pond-ditch water, and AFB1 contamination in proper order. Recognition of the mode of the combination effects of relevant risk factors was important for the causal explanation and public health practice.
Aflatoxin B1↗
[An immunohistochemical study of Ki-67 expression of brain tumor cells and mononuclear cell subsets infiltrating these tumors].
Fifty-one brain tumors were studied by immunohistochemical methods. The densities of CD45RO+, CD4(OPD4) and CD8 T cells infiltrating the tumors showed negative correlation with the tumor size and positive correlation with the density of macrophages. The density of Ki-67+ tumor cells rose along with the increase in tumor malignancy and showed positive correlation with the tumor size and negative correlation with the density of CD4 T cells. The CD4/CD8 ratio was 0.853, far lower than the normal ratio and there was also positive correlation between their densities. The above results suggest that the level of Ki-67 expression can objectively reflect the proliferative rate and malignant grade of brain tumors. The CD45RO+, CD4 and CD8 T cells infiltrating brain tumors are able to directly inhibit tumor growth. The macrophages take part indirectly in the immunoresponse against brain tumors by influencing CD4 and CD8 T cells. Brain tumors may inhibit the proliferation and immune function of the CD4 subset.
Adolescent↗
[Modelling the general relative risk models in case-control studies of primary hepatocellular carcinoma].
This paper was to analyse the effect of risk factors of primary hepatocellular carcinoma (PHC). The analysis was carried on using the family of relative risk functions to asses which scale could better explain the risk structure underlying the data. The results showed that the risk factors of PHC in south area of China were HBV infection, family history of PHC, drank pond-ditch water, while the risk factors of PHC in north area were HBV infection, family history of PHC, history of hepatitis, drank alcohol. The results suggested that the combined effect of risk factors was near to multiplicative. Being able to discriminate between risk structures has important implications on causal interpretation and public health practice.
Carcinoma, Hepatocellular↗
Scavenging effects of tetramethylpyrazine on active oxygen free radicals.
The scavenging effects of tetramethylpyrazine (ligustrazine, Lig) isolated from Ligusticum wallichii Franch on active oxygen free radicals were studied using spin trapping technic and chemiluminescence methods. The scavenging rate of superoxide anion (O2-.) by Lig (25 mg.ml-1) was 100% in xanthine/xanthine oxidase (Xan/XO) system, and that of hydroxyl radical (OH-.) was 44% in Fenton's reaction. The scavenging rate of lipid peroxyl radical (LOO-.) by Lig (25 mg.ml-1) was 80% in peroxidizing microsome system. It is possible that Lig scavenged O2-. by catalyzing its spontaneous dismutation. The results showed that Lig had strong effects of scavenging cyotoxic oxygen free radicals (O2-., LOO-., OH-.).
Animals↗
[Immunohistochemical observations on 67 hemangioblastomas].
67 hemangioblastomas of three histological types were observed utilizing immunohistochemical methods. It was found that endothelia were positive for FVIII pericytes positive for desmin and stromal cells positive for NSE. All these cells expressed vimentin without significant difference. The difference in expression of the 4 antigens stated above was also not significant between the three cell types. These facts suggest that all the cells may have originated from primitive angiogenic mesenchymal cells and the three types of hemangioblastomas are different in morphology but have identical histogenesis. The cells positive for GFAP, S-100 and ACT are all astrocytes enveloped or buried in hemangioblastomas.
Cerebellar Neoplasms↗
[The activities of 3 enzymes in serum and cerebrospinal fluid for diagnosis of tuberculous meningitis].
The adenosine deaminase (ADA), lysozyme (LZM) and lactate dehydrogenase (LDH) of serum and cerebrospinal fluid (CSF) were determined in 36 patients with tuberculous meningitis (TBM), 47 patients with non-tuberculous meningitis (N-T-BM) and 20 patients with non-central nervous system diseases(control group). The results showed that the assessment of serum and CSF ADA and LZM activity may be helpful to the differential diagnosis between TBM and N-TBM.
Adenosine Deaminase↗
Somatosensory evoked potentials in patients with cerebral hemorrhage and infarct. Correlation with CT, clinical data and their prognostic significance on limb function.
Somatosensory evoked potentials (SEP) arising from median nerve stimulation were recorded in 102 patients with unilateral cerebral hemorrhage or infarct located in basal ganglion, internal capsule, thalamus or cerebral lobe. Of them 42 cases were followed up and reexamined with SEPs. Three types of SEPs were observed: 1) absence of all SEPs components, 39 cases; 2) slight to moderate abnormalities of SEPs, 37 cases; 3) symmetric and normal SEPs, 26 cases. The total abnormal rate of SEPs was 76.5%. There were no definite correlations between abnormal SEPs and lesion location, size and lesion nature. The diagnosis of cerebral vascular disease might be obtained more directly and precisely by CT scan than by SEPs. However, SEPs may serve as an objective neurophysiologic means in assessing the neurological function of the affected limb, in which their abnormalities and severity are of great value to evaluate the probability and the degree of sensorimotor functional rehabilitation of the limb. When SEPs are absent, the recovery of the limb functions may be very poor no matter whether it is hemorrhage or infarct regardless of its lesion size and location.
Adult↗
[The aflatoxins and liver cancer in Guangxi, China].
The AFB1 intake and the AFM1 excretion of 81 households in 10 villages, Guanxi were investigated using the ELISA method. The results showed that there was positive correlation between PLC mortality and AFB1 intake from corn and peanut oil, but not from rice. The results of stepwise regression showed that main factors were AFB1 intake of males, AFM1 excretion of females and consumption of corn. The results showed that aflatoxins were correlated with mortality rates of liver cancer. Further investigation needs to be carried out in case-control and cohort studies.
Aflatoxin B1↗
A case-control study of dietary and nondietary risk factors for breast cancer in Shanghai.
A case-control study of breast cancer (186 cases, 186 population, and 186 hospital controls) was conducted in Shanghai, China, between 1982 and 1984. This population has a high daily caloric intake (population control mean, 2394 kcal) and low percentage of calories from fat (22.7%) compared to Western populations. Cases have a significantly greater daily caloric intake than controls, primarily because of increased consumption of monounsaturated fat for which the relative risk is 1.89 for the highest compared to the lowest quintile (P = 0.02). This finding requires cautious interpretation but seems worthy of further study in populations with similar dietary practices.
Breast Neoplasms↗
[Laboratory study on the relationship between drinking water and hepatoma--quantitative evaluation using hepatic gamma-GT method].
One to two-month-old male Fischer 344 (F-344) rats were used in this investigation. The experiment was devised simulating the Two-stage Hepatocarcinogenesis Model described by Pitot. Quantitative stereological method was applied to evaluate the gamma-GT enzyme altered foci (EAF) in examined liver slides. The results showed that pond-ditch water had an enhancement effect on the expression of gamma-GT in the livers of male F-344 rats, where as well water had no such effect. When AFB1 was given alone to the male F-344 rats after partial hepatectomy, there was no effect on gamma-GT, if it was followed by pond-ditch water the rats would express high frequency of EAF. In this experiment the effect of organochlorinated pesticide DDT on hepatic gamma-GT was also studied. It showed a strong influence on the quantity and size of EAF.
Aflatoxin B1↗
An analysis of epidemic factors in cervical cancer by conditional logistic regression model.
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Carcinoma in Situ↗