ISSN:0959-8278    

出版商:OVID    

年代:1991

数据来源: OVID

ISSN:0959-8278    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Increases in cutaneous malignant melanoma (CMM) incidence and mortality rates have occurred in the last decades in virtually all white populations, more markedly in those which permanently (immigrants) or temporarily (tourists/vacationers) reside in very sunny areas distant from their original living environment. The strong relationship between sex and site of CMM in these upward trends (ie trunk in males, lower limbs and, more recently, trunk as well in females) points to intense intermittent ultraviolet light exposure as the cause of the CMM epidemic. In Europe the highest rates of melanoma are seen in Denmark, The Netherlands, the United Kingdom, Ireland and Germany, where many individuals have light complexion with tendency to burn. Increases of 2 to 7% per year in mortality rates appeared earlier in these countries, but were subsequently seen also in relatively low-risk areas such as southern European countries. The interpretation of data from case-control studies is, however, hampered by the difficulties in quantifying retrospectively CMM risk correlates (ie host factors, sun exposure, clothing habits, sunburns etc) in various periods during the life span.

ISSN:0959-8278    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Reports in the literature indicate that there is a change in the pattern of oesophageal cancer. This prompted us to retrospectively examine 15 years of endoscopy records in this district general hospital to identify all patients with oesophageal cancer and to determine whether data from our area were similar to other reported series. Examination of 22,789 consecutive endoscopy records identified 199 oesophageal cancer cases. Overall 50% of these were adenocarcinomas, an even higher percentage than that reported in series based on cancer registry information. The number of squamous cell carcinomas in females was noted to be rising and this was associated with an increase in the age of female patients. Female patients were also significantly older than males. The cancer origins tended to be lower in the oesophagus in males than in females. These results support a rise in the percentage of oesophageal adenocarcinomas. Absolute numbers of cancers detected rose over the 15-year study, but this was in direct proportion to the number of endoscopies carried out annually and probably reflects an increased usage of endoscopy services during the period of study.

ISSN:0959-8278    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

In a case-referent study on the possible role of selenium in human mammary carcinogenesis, serum selenium was found to be 79 ± 12 μg/1 in 66 cases and 81 ± 12 μg/1 in 93 referents. An internal trend in serum selenium was observed among cases (TNM stage I 81 ± 11 μg/1 and TNM stage II 76 ± 13 μg selenium/1), indicating disease-mediated changes. The evaluation of selenium as a risk indicator in human breast cancer was therefore restricted to TNM stage I patients (n = 36). Multiple logistic regression analyses including variables associated with selenium levels revealed no association between selenium levels and breast cancer risk.

ISSN:0959-8278    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Serum selenium concentrations were measured in 126 matched sets of cases—patients with endoscopically proven intestinal metaplasia (IM) and two different controls, matched for age (±3 years) and sex. The controls were either endoscopic controls (EC) who had endoscopically proven normal stomachs or non-endoscopic controls (NC), recruited from fracture and general surgical clinics. The cases and controls were recruited from four centres in the UK. Using a paired analysis, no significant difference was seen for IM vs EC either overall or between centres. However, these findings are compatible with reports of lower serum selenium in areas with a high risk of gastric cancer provided that selenium plays its role in the later stages of the disease.

ISSN:0959-8278    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Patients (1,643) undergoing vagotomy for peptic ulcer at York District Hospital were traced through the Office of Populations Censuses and Surveys (OPCS) and cause of mortality obtained for the 577 who had died. Expected mortality for the cohort was calculated using a years at risk calculation in 5 year bands. There was an excess risk of mortality from cancer of all sites (1.5-fold), stomach (1.6-fold), colorectum (1.7-fold), biliary tract (4.1-fold) and lung (1.6-fold). There was no excess risk or mortality from cancer of the oesophagus, pancreas and female breast. The numbers of deaths have been too few and length of follow-up too short to investigate latency. The findings are consistent with the production of carcinogens as a result of the hypoacidity following vagotomy.

ISSN:0959-8278    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Dextro (d) and laevo (l) forms of quartz dust was inoculated intranasally and subcutaneously into 2-month-old (C57 x BALB/c)F1 mice which were killed 18 months later. Both d and l quartz caused fibrosis, liver nodule formation and an enhanced incidence of lymphoma leukemia. However, the tumour incidence was significantly higher in l than in d quartz dust-treated animals. It is concluded that in addition to effects clearly independent of chirality there is evidence that the biological response to nonidentical mirror images of solid crystals may differ.

ISSN:0959-8278    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Exposure to N-nitroso-compounds and aromatic amines, xenobiotics which require an activation in order to exert their genotoxic potential, is causally associated with gastric cancer. We evaluated the capacity of microsome-containing fractions from human gastric mucosa to activate two model carcinogenic compounds. A 9,000 x g supernatant (S9) was obtained from gastric mucosal specimens and, for comparison, from human liver and aroclor-induced and non induced rat liver. The capacity of the S9 to activate N-nitrosopyrrolidine (NPY) and 2-aminofluorene (2AF) to mutagenic metabolites was tested in the Ames/Salmonella reversion assay, while dimethylnitrosamine (DMN) and aminopyrine (AP) demethylation activities were spectrophotometrically evaluated by using an enzymatic assay of the amount of formaldehyde released following the enzymatic demethylation of the corresponding substrates. Results indicate that human gastric S9 fractions may activate 2AF to a genotoxic derivative and are characterized by DMN and AP demethylase activities higher (p < 0.05) than those of human liver, when expressed in mg/protein (p < 0.05). Although the parameters evaluated can only be considered as a partial measure of the general activating capacity toward dietary and environmental procarcinogens, these results suggest that human gastric mucosa may be directly involved in the metabolic activation of these compounds to mutagenic carcinogenic species.

ISSN:0959-8278    

出版商:OVID    

年代:1991

数据来源: OVID

ISSN:0959-8278    

出版商:OVID    

年代:1991

数据来源: OVID