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排序方式: 共有140条查询结果,搜索用时 15 毫秒
1.
Hardies SC; Martin SL; Voliva CF; Hutchison CA d; Edgell MH 《Molecular biology and evolution》1986,3(2):109-125
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M. Nordstr?m B. Lindblad H. Anderson D. Bergqvist T. Kjellstr?m 《BMJ (Clinical research ed.)》1994,308(6933):891-894
OBJECTIVE--To determine the risk of subsequent cancer in patients with deep venous thrombosis confirmed by venography. DESIGN--Follow up of all patients who had venography for suspected deep venous thrombosis during 1984-88. Patients were traced through a cancer registry up to 1 January 1991. SUBJECTS--4399 patients who had phlebography in one hospital. SETTING--General hospital in Malmö, Sweden, serving a population of 230,000. MAIN OUTCOME MEASURE--Number of cancers recorded. RESULTS--4399 patients had venography for suspected deep venous thrombosis; 604 were known to have a malignancy at the time of venography and were excluded from further analysis. 1383 had deep venous thrombosis, 150 of whom subsequently developed cancer. 182 of the 2412 patients without thrombosis developed cancer. During the first six months after venography 66 patients with thrombosis developed malignancy compared with 37 patients without thrombosis (P < 0.0001). 38 of the cancers in the deep venous thrombosis group were detected by history, physical examination, and laboratory tests. Three patients had postoperative or post-traumatic deep venous thromboses. Only two of the remaining patients would have benefited from early detection by extensive screening. After six months the incidence of cancer was identical in patients with and without thrombosis. CONCLUSION--Deep venous thrombosis is associated with a significantly higher frequency of malignancy during the first six months after diagnosis. Malignancies can be found with simple clinical and diagnostic methods and extensive screening is not required. 相似文献
4.
A major difference between the divergence patterns within the lines-1 families in mice and voles 总被引:3,自引:0,他引:3
Vanlerberghe F; Bonhomme F; Hutchison CA d; Edgell MH 《Molecular biology and evolution》1993,10(4):719-731
L1 retroposons are represented in mice by subfamilies of interspersed
sequences of varied abundance. Previous analyses have indicated that
subfamilies are generated by duplicative transposition of a small number of
members of the L1 family, the progeny of which then become a major
component of the murine L1 population, and are not due to any active
processes generating homology within preexisting groups of elements in a
particular species. In mice, more than a third of the L1 elements belong to
a clade that became active approximately 5 Mya and whose elements are >
or = 95% identical. We have collected sequence information from 13 L1
elements isolated from two species of voles (Rodentia: Microtinae: Microtus
and Arvicola) and have found that divergence within the vole L1 population
is quite different from that in mice, in that there is no abundant
subfamily of homologous elements. Individual L1 elements from voles are
very divergent from one another and belong to a clade that began a period
of elevated duplicative transposition approximately 13 Mya. Sequence
analyses of portions of these divergent L1 elements (approximately 250 bp
each) gave no evidence for concerted evolution having acted on the vole L1
elements since the split of the two vole lineages approximately 3.5 Mya;
that is, the observed interspecific divergence (6.7%-24.7%) is not larger
than the intraspecific divergence (7.9%-27.2%), and phylogenetic analyses
showed no clustering into Arvicola and Microtus clades.
相似文献
5.
Brain Quinolinic Acid in Chronic Experimental Hepatic Encephalopathy: Effects of an Exogenous Ammonium Acetate Challenge 总被引:1,自引:1,他引:0
Peter B. F. Bergqvist Melvyn P. Heyes †Mogens Bugge Finn Bengtsson 《Journal of neurochemistry》1995,65(5):2235-2240
Abstract: Elevated brain concentrations of the neurotoxin and NMDA receptor agonist quinolinic acid (QUIN) have been demonstrated in portacaval-shunted (PCS) rats, a chronic hepatic encephalopathy (HE) model. Increased brain QUIN levels have also been shown in acute hyperammonemic rats. In the present study, the plasma and brain (neocortical) QUIN levels in chronic PCS rats were investigated. The study also included a single exogenous ammonium acetate (NH4 Ac; 5.2 mmol/kg, i.p.) challenge to precipitate a reversible hepatic coma. Compared with sham-operated controls, chronic PCS rats exhibited decreased rather than increased plasma and brain QUIN levels. The plasma-to-brain QUIN ratio was not found to be altered. The NH4 Ac administration induced coma in all of the PCS rats 20–25 min after the challenge, and this coma was resolved within 60–75 min. No relevant temporal relationship between changes in brain QUIN levels and the neurological status in the PCS rats was observed. Therefore, our results do not support the contention that increased brain QUIN levels per se are involved in the pathogenesis of HE. 相似文献
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Oylum Erkus Victor CL de Jager Maciej Spus Ingrid J van Alen-Boerrigter Irma MH van Rijswijck Lucie Hazelwood Patrick WM Janssen Sacha AFT van Hijum Michiel Kleerebezem Eddy J Smid 《The ISME journal》2013,7(11):2126-2136
Maintenance of a high degree of biodiversity in homogeneous environments is poorly understood. A complex cheese starter culture with a long history of use was characterized as a model system to study simple microbial communities. Eight distinct genetic lineages were identified, encompassing two species: Lactococcus lactis and Leuconostoc mesenteroides. The genetic lineages were found to be collections of strains with variable plasmid content and phage sensitivities. Kill-the-winner hypothesis explaining the suppression of the fittest strains by density-dependent phage predation was operational at the strain level. This prevents the eradication of entire genetic lineages from the community during propagation regimes (back-slopping), stabilizing the genetic heterogeneity in the starter culture against environmental uncertainty. 相似文献
8.
Irisin was first identified in muscle cells. We detected irisin immunoreactivity in various organs of the crested porcupine (Hystrix cristata). In the epidermis, irisin immunoreactivity was localized mainly in stratum basale, stratum spinosum and stratum granulosum layers; immunoreactivity was not observed in the stratum corneum. In the dermis, irisin was found in the external and internal root sheath, cortex and medulla of hair follicles, and in sebaceous glands. Irisin immunoreactivity was found in the neural retina and skeletal muscle fibers associated with the eye. The pineal and thyroid glands also exhibited irisin immunoreactivity. 相似文献
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Malm M Bergqvist Y 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2007,846(1-2):98-104
A bioanalytical method for determination of eflornithine (DFMO) in 1000 microL human plasma has been developed and validated. DFMO and the internal standard (IS) were analysed by liquid chromatography with evaporative light-scattering detection (ELSD). Separation was performed on a Chirobiotic TAG (250 mm x 4.6 mm) column with ethanol (99.5%):0.01 mol/L acetic acid-triethylamine buffer at the rate of 25:75% (v/v) with flow rate of 1.0 mL/min. For d-DFMO in plasma the inter-assay precision was 6.5% at 75 micromol/L, 6.6% at 375 micromol/L and 5.8% at 750 micromol/L. For l-DFMO in plasma the inter-assay precision was 10.4% at 75 micromol/L, 6.5% at 375 micromol/L and 5.0% at 750 micromol/L. The lower limit of quantification (LLOQ) was determined to 25 micromol/L where the precision was 4.3% and 5.7%, respectively. 相似文献