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H I Morrison  P R Band  R Gallagher  J Spinelli  D T Wigle 《CMAJ》1984,131(9):1069-1071
A total of 64 cases of pleural mesothelioma were reported in British Columbia between 1973 and 1980, 54 in males and 10 in females. There was a significant (p less than 0.05) increase in the incidence among males. The overall incidence rates were 4.9 and 0.9 per million person-years for males and females respectively. The age distribution of the cases was roughly exponential up to age 70 years. Almost all of the cases were clustered in Cowichan Valley, Capital and Greater Vancouver counties, where there was a high level of shipbuilding activity 30 to 40 years ago. The increased incidence in males may be related to this activity, which involved exposure to asbestos.  相似文献   

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Background: A recent decline in breast cancer incidence rates has been reported in the United States and in Europe. This decrease has been partly attributed to the reduced use of hormone replacement therapy (HRT). No study in Europe has detailed recent breast cancer incidence trends both by hormonal receptor status and mode of detection at an individual level. Methods: We examined trends in breast cancer incidence rates in the French administrative area of Loire-Atlantique between 1991 and 2007, by age, mode of detection, histological subtype, estrogen/progesterone receptor (ER/PR) status and grade. Annual age-standardized breast cancer incidence rates were estimated using the Loire-Atlantique and Vendée Cancer Registry data. Annual percentage changes (APCs) were estimated using an age-adjusted Poisson regression model. Results: Incidence rates of breast cancer increased 3.5% per year in 1991–2003, dropped ?4.3% per year in 2003–2006 and increased in 2007 (9.1%). Stratified analyses by age groups showed that the decrease concerned predominantly women aged 50–64 years, whereas an increasing proportion of cancers detected by organized screening was observed in this age group. Among these women, the decline of incidence particularly concerned positive estrogen and progesterone receptor tumors, lobular subtype tumors, and low-grade tumors. Conclusion: The drop in breast cancer incidence rates observed between 2003 and 2006 in women 50–64 years old was greater for ER+PR+ tumors. During the same period, the incidence of breast cancers diagnosed by organized screening increased. These patterns appear consistent with an impact of the reduced use of HRT.  相似文献   

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Recent trends in the biochemistry of surfactin   总被引:49,自引:0,他引:49  
The name surfactin refers to a bacterial cyclic lipopeptide, primarily renowned for its exceptional surfactant power since it lowers the surface tension of water from 72 mN m−1 to 27 mN m−1 at a concentration as low as 20 μM. Although surfactin was discovered about 30 years ago, there has been a revival of interest in this compound over the past decade, triggered by an increasing demand for effective biosurfactants for difficult contemporary ecological problems. This simple molecule also looks very promising as an antitumoral, antiviral and anti-Mycoplasma agent. Structural characteristics show the presence of a heptapeptide with an LLDLLDL chiral sequence linked, via a lactone bond, to a β-hydroxy fatty acid with 13–15 C atoms. In solution, the molecule exhibits a characteristic “horse saddle” conformation that accounts for its large spectrum of biological activity, making it very attractive for both industrial applications and academic studies. Surfactin biosynthesis is catalysed non-ribosomally by the action of a large multienzyme complex consisting of four modular building blocks, called the surfactin synthetase. The biosynthetic activity involves the multicarrier thiotemplate mechanism and the enzyme is organized in structural domains that place it in the family of peptide synthetases, a class of enzymes involved in peptidic secondary-metabolite synthesis. The srfA operon, the sfp gene encoding a 4′-phosphopantetheinyltransferase and the comA regulatory gene work together for surfactin biosynthesis, while the gene encoding the acyltransferase remains to be isolated. Concerning surfactin production, there is no indication whether the genetic regulation, involving a quorum-sensing mechanism, overrides other regulation factors promoted by the fermentation conditions. Knowledge of the modular arrangement of the peptide synthetases is of the utmost relevance to combinatorial biosynthetic approaches and has been successfully used at the gene level to modify the surfactin template. Biosynthetic and genetic rationales have been described for building variants. A fine study of the structure/function relationships associated with the three-dimensional structure has led to the recognition of the specific residues required for activity. These studies will assist researchers in the selection of molecules with improved and/or refined properties useful in oil and biomedical industries. Received: 9 October 1998 / Received revision: 29 January 1999 / Accepted: 31 January 1999  相似文献   

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Excess weight afflicts the majority of the US adult population. Research suggests that the role of primary care physicians in reducing overweight and obesity is essential; moreover, little is known about self-care of obesity. This report assessed the secular trends in the care of overweight and investigated the secular association between obesity with care of overweight in primary care and self-care of overweight. Cross-sectional evaluation of the National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and the Continuous NHANES (1999-2008) was employed; the total sample comprised 31,039 nonpregnant adults aged 20-90 years. The relationship between diagnosed overweight, and directed weight loss with time and obesity was assessed. Despite the combined secular increase in the prevalence of overweight and obesity (BMI >25.0 kg/m(2)) between 1994 and 2008 (56.1-69.1%), there was no secular change in the odds of being diagnosed overweight by a physician when adjusted for covariates; however, overweight and obese individuals were 40 and 42% less likely to self-diagnose as overweight, and 34 and 41% less likely to self-direct weight loss in 2008 compared to 1994, respectively. Physicians were also significantly less likely to direct weight loss for overweight and obese adults with weight-related comorbidities across time (P < 0.05). Thus, the surveillance of secular trends reveals that the likelihood of physician- and self-care of overweight decreased between 1994 and 2008 and further highlights the deficiencies in the management of excess weight.  相似文献   

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Cancer control encompasses the whole spectrum from prevention and early diagnosis to treatment and palliation. The key to the future of cancer control will be to establish multidisciplinary approaches to each type of cancer across this spectrum. For primary prevention this requires some understanding of the causes of each cancer. Although understanding of the aetiology of cancer has greatly improved, prospects for the primary prevention of many common cancers remain remote. Other approaches currently under evaluation include chemoprevention and the use of biomarkers (discussed last week). The identification of predisposing genes for some of the common cancers may have a considerable impact on the ability to recognise those at risk. Overall, however, mortality trends indicate that reduction of smoking remains the main priority for cancer prevention in the United Kingdom. For primary care teams, brief interventions to reduce smoking are likely to achieve the greatest benefit. This should be seen as part of broader policies aimed at achieving change in the whole population. The government must acknowledge its major responsibility to cancer prevention by banning all forms of advertising and promotion of tobacco.  相似文献   

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A rapid decline in fertility took place in Suriname between 1962 and 1974, and then stopped. While this sudden stabilization is surprising, it is not unusual. Similar trends have occurred in some Caribbean and Latin American countries. This article analyzes the post-1960 trend in fertility in Suriname and seeks to determine whether the 1962-74 fertility decline resulted from changes in socioeconomic conditions or was caused by the activities of the Suriname Family Planning Association. The measures used are the general fertility rate, the total fertility rate by ethnic group as well as by 5-year age groups, and gross and net reproduction rates by ethnic group. All the measures point to a rapid continuing decline of fertility between 1962 and 1974, followed by a rise. The data suggest that major socioeconomic changes had already been under way for some years, when fertility started to fall in 1962. The Suriname Family Planning Association was not founded until 1968, which implies that the organization did not start the decrease. However, once the organization was founded, it continually expanded its activities and made an obvious contribution to the use of contraceptives that increased significantly in the 1970s. It is concluded that the drop in fertility resulted from the process of modernization along with the rapid increase in the use of contraceptives.  相似文献   

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The majority of current biotechnological applications are of microbial origin, and it is widely appreciated that the microbial world contains by far the greatest fraction of biodiversity in the biosphere. Because of their biotech impact, numerous efforts are being undertaken worldwide, with an ultimate goal to deliver new usable substances of microbial origin to the marketplace. However, the direct isolation of microbes always revealed that the majority are not amenable to be cultured and no representatives for many major microbial phyla have been thus far characterized. Therefore, the knowledge on new microbes and/or genomic information thereof, or from their communities, will pose an enormous potential to provide industry with novel products and processes based on the use of microbial resources, and contribute to and extend the basic mechanistic knowledge on the functioning of organisms. The present review highlights some examples and advances in the exploration of the genetic reservoir of (un)cultured microbes for industrial applications.  相似文献   

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Incidence and survival rates were estimated for all white and black women in metropolitan Atlanta with a new diagnosis of in situ or invasive cervical carcinoma between 1975 and 1986. During this period, the average annual age-adjusted incidence (per 100,000) of in situ lesions declined from 51.4 to 25.6 among whites and from 102.2 to 34.6 among blacks. The average annual age-adjusted incidence rate of invasive cervical cancer decreased from 11.8 to 8.2 for whites and from 33.0 to 26.7 for blacks. Although the black-to-white ratio of carcinoma in situ incidence rates declined progressively over time, the excess of invasive cancer among blacks did not decrease. The five-year cumulative survival percentages by stage for whites and blacks, respectively, were 99.1 and 99.1 for in situ carcinoma, 92.2 and 80.5 for locally invasive carcinoma, 49.2 and 40.5 for regionally invasive carcinoma and 3.1 and 3.4 for cases with distant metastases. No improvements in stage at diagnosis of invasive cancer or stage-specific survival rates were observed during this period.  相似文献   

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