ISSN:0959-8278    

出版商:OVID    

年代:1995

数据来源: OVID

ISSN:0959-8278    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Epidemiological data on occupational exposure and personal use of hair dyes was reviewed with specific focus on bladder cancer and lymphoid neoplasms. At least seven cohort and 11 case-control studies included data on occupational exposure to hair dyes by hairdressers, barbers and beauticians, and their subsequent bladder cancer risk. The relative risk (RR) estimate was 1.4 (183 observedvs129 expected) for cohort studies, and in several casecontrol studies the RRs were somewhat above unity. These results are compatible with some moderate association between past professional exposure to hair dyes and subsequent bladder cancer risk, but also with errors and biases in observational epidemiological studies, particularly since allowance for smoking was lacking or inadequate in most studies. An open question is whether current occupational exposure to modern hair dyes is still related to some excess bladder cancer risk. Five case-control studies included information on personal use of hair dyes and bladder cancer risk. There was no evidence of any association. Nine cohort and eight case-control studies considering occupational exposure to hair dyes and lymphoid neoplasms were reviewed. In the cohort studies, a total of 100 lympboid neoplasms was observed compared with 84.4 expected (RR 1.2). The RR estimates were 1.5 for non-Hodgkin's lympbomas (NHL, 17 observedvs11.2 expected) and 1.1 for multiple myeloma (MM, 19 observed casesvs16.8 expected). Interpretation of case-control studies of occupational exposure is seriously hampered by the small number of exposed cases. Five case-control studies considered personal use of hair dyes and the risk of lymphoid neoplasms. Of these, three reported some association, particularly with NHL and MM. However, the RR estimates were only moderately above unity, and inadequate allowance was made for potential confounding factors, including social class and greying hair, which could be correlates of both hair dye use and lymphoid neoplasms. Further, there is little information on the biodistribution and bioavailability of potential carcinogens in hair dyes, particularly their concentrations in lymphoid tissue. These findings, therefore, require further research, particularly since they may be influenced by selective publication of positive findings (publication bias). None of the other neoplasms extensively studied, including breast, skin and lung was related to hair dye use.

ISSN:0959-8278    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Several epidemiological, clinical and experimental studies have been carried out to determine whether there is an aetiological role for schistosomiasis in the multi-stage process of bladder carcinogenesis. Lines of evidence supporting the association between bladder cancer and schistosomiasis include indications from the geographical correlation between the two conditions, the distinctive patterns of gender and age at diagnosis, the clinicopathological identity of schistosome-associated bladder cancer and the extensive experimental evidence in infected laboratory animals. Although the causative role of schistosomiasis is now accepted, various associated factors have been proposed in the induction of this particular type of cancer. While all may contribute to the carcinogenic process taking place in the infected bladder, none of these has yet been confirmed. Most attention has been directed at theories proposing possible roles for urinary chemical carcinogens, particularly tryptophan metabolites, N-nitroso compounds and of -glucuronidase, as factors that are primarily involved in the initiation of bladder carcinogenesis in areas endemic for schistosomiasis.

ISSN:0959-8278    

出版商:OVID    

年代:1995

数据来源: OVID

ISSN:0959-8278    

出版商:OVID    

年代:1995

数据来源: OVID

ISSN:0959-8278    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

To investigate the prevalence of gastritis andH. pyloriinfection among young Chinese in Henan Province, a high incidence area for oesophageal cancer in China, the gastric mucosa was examined in 194 asymptomatic subjects, aged 15–26 years, in the course of an epidemiological study of precursor lesions of oesophageal cancer. Histopathological grading of gastritis and determination ofH. pyloriinfection were performed on haematoxylineosin and Warthin-Starry stained section. An enzyme-linked immunosorbent assay was used to detect the presence of serum IgG antibodies toH. pylori.A very high prevalence of gastritis (93.8%) was found: 71 subjects (36.6%) presented with superficial gastritis (14 active), 94 (48.5%) with diffuse gastritis (92 active) and in 17 cases (8.8%) diffuse gastritis (16 active) was accompanied by focal atrophy. Silver staining detectedH. pyloriin 166 (85.6%) of the study participants. However, serological techniques identifiedH. pyloriin only 109 (56.2%).H. pyloriwas seen in all the 119 cases showing histological signs of active gastritis, in 41 of the 63 cases (65%) without activity, and also in 50% (6/12) of histologically normal subjects.H. pyloriinfection was found to be associated with a 2.5-fold higher prevalence of chronic atrophic gastritis compared with non-atrophic gastritis. A family history of stomach cancer, consumption of pickled vegetables more than twice a month, and a high monthly salt consumption (> 500 g/ month) also showed a positive association. The widespreadH. pyloriinfection early in life, together with risk factors such as high salt consumption and a general nutritional inadequacy, appeared to contribute to a higher prevalence of chronic gastritis in young adults in China compared with Western countries.

ISSN:0959-8278    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

We have conducted a cohort study of cancer risks among 140,208 Swedish farmers in order to compare their cancer risks with those of the general male population. Since there were no individual data regarding exposure to agricultural chemicals and acquiring such data was not realistic, we obtained crude and hypothetical estimates for exposure by dividing the data into time periods, year-of-birth cohorts and geographical areas. The cohort was folio wed-up in the Cancer Environment Register from 1 January 1971 either until death or until 31 December 1987. The relative risk was computed as the ratio of the observed and expected number of cases (SIR = standardized incidence ratio). A total of 15,040 cases were observedvs18,918 expected, resulting in a statistically significant decreased SIR of 0.80 (95% confidence interval: 0.78–0.81). The SIR was significantly decreased for several cancer sites, and the lowest value was found for tongue, lung, oesophagus, liver and urinary organs, which is in agreement with other studies on cancer risks among farmers. Other major cancer sites with decreased SIRs were the colon, rectum, pancreas and kidney. Lip cancer and multiple myeloma showed statistically significant increased risks. SIRs for stomach cancer, prostate cancer, skin carcinoma, malignant melanoma, tumours in connective tissue or muscle, malignant lymphomas and leukaemia were all close to unity, which is not consistent with several other studies that have shown increased risks for these sites. For malignant lymphomas the SIR increased over time, though not significantly, and was highest among younger farmers. The SIR for non-Hodgkin lymphoma was lowest in the northernmost region. This gives some support to the hypothesis that there is an association between non-Hodgkin lympboma and exposure to pesticides and other agricultural chemicals. It is of note that the SIR for multiple myeloma was significantly increased in those parts of Sweden where the use of pesticides has been less frequent and in lower amounts.

ISSN:0959-8278    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Plasma selenium and glutathione peroxidase in erythrocytes were analysed in a case-control study encompassing 164 cases with prostate cancer and 152 controls with benign prostate hyperplasia. Plasma selenium levels were divided into three groups; I > 1.17, II 1.00–1.17 and III < 1.00 μmol/l. For the 124 cases with no supplementary intake of selenium pills, the mean plasma selenium level was 0.99 (range 0.27–1.47) and for the corresponding 121 controls 1.08 (range 0.52–1.50) μmol/l, a difference which was significant (P= 0.0007). The three categories of selenium levels had odds ratios (OR) of 0.3 and a 95% confidence interval (CI) of 0.1–0.7 for group I, an OR of 0.6 and a CI of 0.3–1.1 for group II, and group III was used as the reference entity. No significant differences in levels of glutathione peroxidase in erythrocytes were found between cases and controls.

ISSN:0959-8278    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

A survey has been conducted during the past decade (starting in 1980) of reported new cases of women with breast cancer, in order to assess the interim evidence of the natural experiment of the effect of increased use of condoms on the risk of breast cancer in the US. Age-adjusted incidence rates of breast cancer (to the world standard population) per 100,000 population, and trends of changes, in percentages, were used. Prior to the 1980s, breast cancer incidence was in decline in seven out of 13 centres in the country. Following the recommendations to use condoms in ‘safer sex’ campaigns, increases of breast cancer incidence were recorded during the 1980s, as a reflection of a global phenomenon. Between the 5 year periods of 1978–82 and 1983–87, the population of the nine Surveillance, Epidemiology and End Results programme (SEER) centres (about 10% of the American population), increased by 2.9%, the number of breast cancer cases increased by 25.0%; the average annual breast cancer crude incidence rose by 21.5% (from 100.8 to 122.5 per 100,000). The increase in the average annual number of breast cancer cases during the period 1983–87 (the period of increased condom usage) was 4.5 times greater than that during the preceding period, 1978–82. During the 1980s, breast cancer trends rose significantly in the US among White women (P< 0.00001) and other ethnic groups (P< 0.005). The difference between the expected, 21%, and observed, 79%, probability of adverse effects occurring in the natural experimental trial was statistically significant (P= 0.0001). The results of the study were consistent with the conceptual framework of the hypothesis that the increase in the prevalence of condom use in the general population was most probably the primary environmental determinant of the recent rise of incidence of breast cancer. This may lend support to the argument for an alternate action of primary prevention against AIDS in the community.

ISSN:0959-8278    

出版商:OVID    

年代:1995

数据来源: OVID