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OBJECTIVE--To confirm or refute reports that vasectomy may increase the risk of cancers of the testis and prostate. DESIGN--Computerised record linkage study of cohort of men with vasectomy and comparison of cancer rates with those in the whole Danish population; manual check of all records of patients with testicular and prostate cancer diagnosed within the first year of follow up. SETTING--Denmark 1977-89. SUBJECTS--Cohort of 73,917 men identified in hospital discharge and pathology registers as having had a vasectomy for any reason during 1977-89. MAIN OUTCOME MEASURES--Observed incidences of testicular, prostate, and other cancers up to the end of 1989. RESULTS--The overall pattern of cancer incidence in the study cohort was similar to that expected nationally. No increased incidence in testicular cancer was observed (70 cases; standardised morbidity ratio 1.01 (95% confidence interval 0.79 to 1.28)). The incidence during the first year of follow up was also close to that expected (nine cases; standardised morbidity ratio 0.80 (0.36 to 1.51)). The incidence of prostate cancer was not increased (165 cases; standardised morbidity ratio 0.98 (0.84 to 1.14)). CONCLUSIONS--The incidence of testicular cancer in men with vasectomy is no higher than in other men. Vasectomy does not cause testicular cancer and does not accelerate the growth or diagnosis of pre-existing testicular neoplasms. Data concerning a causal relation between vasectomy and prostate cancer were inconclusive. 相似文献
184.
This comparative study explores how low temperatures affect the mortality and growth of first generation hatchery-reared progeny
of subarctic populations of Arctic charr (Salvelinus alpinus L.) and European whitefish (Coregonus lavaretus L.). Replicate fish groups where held under simulated natural light regimes (70°N) at three constant temperatures (1, 3 and
6°C). The mortality of Arctic charr was low (≤1.4%) at all temperature treatments, whereas the mortality of whitefish increased
with decreasing temperature from 6% at 6°C to 33% at 1°C. The Arctic charr exhibited higher growth rates than whitefish at
all three temperature regimes. All groups of Arctic charr increased in weight, whereas whitefish held at 1°C did not gain
weight throughout the experimental period of 133 days. Arctic charr exhibited a large intraspecific variability in growth
leading to large variations in size-structure, whereas whitefish in contrast showed very homogenous growth and size-structure
patterns; a dissimilarity probably related to species-specific differences in antagonistic behaviour. Evidently, Arctic charr
are more cold water adapted than whitefish and are able to maintain growth at extremely low temperatures. Arctic charr thus
appear to be the most suitable species for aquaculture at low water temperatures. 相似文献
185.
The possibility of using intense sound as an acoustic barrier for downstream migrating smolt of the Atlantic salmon ( Salmo salar ) was studied by observing, the reactions of smolt to 10 and 150 Hz sounds in a small river. At the observation site the river branched into a main course and a minor channel, the latter rejoining the main stream after 30 m. The sound sources were positioned at the lower end of the channel. The number of smolt re-entering the mam stream at the lower end of the channel was recorded during alternating periods with and without sound. Intense 150 Hz sound had no observable effects on the smolt, even at intensities 114 dB above the hearing threshold at this frequency. At intensities above 1.0. 10−2 ms−2 the 10 Hz sound was an effective deterrent for the smolt, which turned and left the channel at the upstream branching point. 相似文献
186.
The induction of polydactyly in mouse embryos heterozygous for Hemimelia-extra toe (Hmx) is associated with aberrant outgrowth of the developing autopod on day 12 of gestation. We have quantitated the rate of DNA synthesis and the activity of cAMP-phosphodiesterase (PDE) that is characteristic of the prospective polydactylous region. Mid-stage 18 hind-limb buds were labeled with [3H]dThd either in situ using whole embryo culture, or as isolated preaxial autopod fragments cultured on a membrane substratum. The mean specific activities of incorporation were compared for normal (+/+) and mutant (Hmx/+) genotypes. A significant (P less than or equal to 0.01) 19% increase, peculiar to the prospective polydactylous region, was measured after 4 hours in embryo culture. The same increment was detected after 4 hours in organ culture, but was amplified linearly to 55% when incubation was extended to 20 hours. During this period, continuous exposure to 1.0 mM IBMX (3-isobutyl-1-methyl xanthine), an inhibitor of cAMP-PDE activity, "slowed down" the rate of DNA synthesis to untreated +/+ proportions. When cAMP-PDE activity was assayed in uncultured autopods, a significant (P less than or equal to 0.01) 18% increase was detected within the prospective polydactylous region specifically on stage 18 of gestation. This is the developmental phase during which polydactylous outgrowth is induced in situ. Thus, uncontrolled cAMP-PDE activity may, in part, provoke the enhanced rate of cell proliferation. 相似文献
187.
Plakoglobin, or an 83-kD homologue distinct from beta-catenin, interacts with E-cadherin and N-cadherin 总被引:24,自引:14,他引:10 下载免费PDF全文
E- and N-cadherin are members of a family of calcium-dependent, cell surface glycoproteins involved in cell-cell adhesion. Extracellularly, the transmembrane cadherins self-associate, while, intracellularly, they interact with the actin-based cytoskeleton. Several intracellular proteins, collectively termed catenins, have been noted to co-immunoprecipitate with E- and N-cadherin and are thought to be involved in linking the cadherins to the cytoskeleton. Two catenins have been identified recently: a 102-kD vinculin-like protein (alpha-catenin) and a 92-kD Drosophila armadillo/plakoglobin-like protein (beta-catenin). Here, we show that plakoglobin, or an 83-kD plakoglobin-like protein, co-immunoprecipitates and colocalizes with both E- and N-cadherin. The 83-kD protein is immunologically distinct from the 92-kD beta-catenin and, because of its molecular mass, likely represents the cadherin-associated protein called gamma-catenin. Thus, two different members of a plakoglobin family associate with N- and E-cadherin and, together with the 102-kD alpha-catenin, appear to participate in linking the cadherins to the actin-based cytoskeleton. 相似文献
188.
S Valla K Frydenlund D H Coucheron K Haugan B Johansen T J?rgensen G Knudsen A Str?m 《Applied and environmental microbiology》1992,58(6):1980-1985
All reported natural isolates of the marine fish pathogen Vibrio salmonicida contain plasmids, and in another marine fish pathogen, Vibrio anguillarum, it has been shown that a plasmid is important for expression of virulence by the organism. To study the function of the plasmids in V. salmonicida, we developed a gene transfer system based on the plasmid RSF1010 replicon. The gene transfer system was used to construct a plasmid-free strain, and this strain was found to behave similarly to the wild type in a fish pathogenicity test based on intraperitoneal injection of the bacteria. We were unable to detect any other phenotypic differences between the two strains. It could therefore be concluded that at least in the V. salmonicida strain tested, extrachromosomal DNA is not required for expression of virulence. 相似文献
189.
Ståle Knudsen 《Ethnos》2018,83(3):505-520
ABSTRACTThis study focuses on the corporate social responsibility (CSR) work the Austrian energy company OMV pursued as it constructed a gas power plant on the shores of the Black Sea. I argue that neither social movement theory nor CSR theory fully explain what happened in this case. Environmental protests quickly became embedded in local politics and national identity figurations, and the CSR work by the company was transformed and domesticated by local actors. While agency and power was thus distributed, various actors also shared a common language, tapping into a globally circulating discourse that has gained traction in Turkey with the current neoliberal policies. The way CSR was played out and negotiated in this case meant that social capital and equity were construed as issues of concern, while environmental issues were downplayed. Thus, in the process, the double bind between the growth economy and ecologies of survival was effectively reproduced. 相似文献
190.