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Julie A. Schmidt Georgina K. Fensom Sabina Rinaldi Augustin Scalbert Paul N. Appleby David Achaintre Audrey Gicquiau Marc J. Gunter Pietro Ferrari Rudolf Kaaks Tilman Kühn Heiner Boeing Antonia Trichopoulou Anna Karakatsani Eleni Peppa Domenico Palli Sabina Sieri Rosario Tumino Bas Bueno-de-Mesquita Antonio Agudo Maria-Jose Sánchez María-Dolores Chirlaque Eva Ardanaz Nerea Larrañaga Aurora Perez-Cornago Nada Assi Elio Riboli Konstantinos K. Tsilidis Timothy J. Key Ruth C. Travis 《International journal of cancer. Journal international du cancer》2020,146(3):720-730
Metabolomics may reveal novel insights into the etiology of prostate cancer, for which few risk factors are established. We investigated the association between patterns in baseline plasma metabolite profile and subsequent prostate cancer risk, using data from 3,057 matched case–control sets from the European Prospective Investigation into Cancer and Nutrition (EPIC). We measured 119 metabolite concentrations in plasma samples, collected on average 9.4 years before diagnosis, by mass spectrometry (AbsoluteIDQ p180 Kit, Biocrates Life Sciences AG). Metabolite patterns were identified using treelet transform, a statistical method for identification of groups of correlated metabolites. Associations of metabolite patterns with prostate cancer risk (OR1SD) were estimated by conditional logistic regression. Supplementary analyses were conducted for metabolite patterns derived using principal component analysis and for individual metabolites. Men with metabolite profiles characterized by higher concentrations of either phosphatidylcholines or hydroxysphingomyelins (OR1SD = 0.77, 95% confidence interval 0.66–0.89), acylcarnitines C18:1 and C18:2, glutamate, ornithine and taurine (OR1SD = 0.72, 0.57–0.90), or lysophosphatidylcholines (OR1SD = 0.81, 0.69–0.95) had lower risk of advanced stage prostate cancer at diagnosis, with no evidence of heterogeneity by follow-up time. Similar associations were observed for the two former patterns with aggressive disease risk (the more aggressive subset of advanced stage), while the latter pattern was inversely related to risk of prostate cancer death (OR1SD = 0.77, 0.61–0.96). No associations were observed for prostate cancer overall or less aggressive tumor subtypes. In conclusion, metabolite patterns may be related to lower risk of more aggressive prostate tumors and prostate cancer death, and might be relevant to etiology of advanced stage prostate cancer. 相似文献
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Cholecystokinin (CCK )isa polypeptidehor monecontaining 33aminoacidsresiduewithgastroin testinal,biliarandbrainactivities Itiswidelydis tributedinthevertebratecentralnervoussystem ,anditcanstimulateextensivelytheliberationofinsulinandglucagonfromtheLangerhansislets GreateffortshavebeendevotedtothesynthesisofCCK 8,itsderivativesandanalogues Amongthedifferentmethods ,theenzymaticmethodisthemosteffectiveonewithmanyadvantagesoverconventionalchemicalmethodologies :enzymespecificitysuppress essid… 相似文献
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Determination of bone mineral density by dual x-ray absorptiometry in patients with uncemented total hip arthroplasty. 总被引:9,自引:0,他引:9
Bone remodeling is an expected sequela with total hip arthroplasty (THA). Although there are several methods of estimating bone response in THA patients from radiographs, there are no accurate and generally accepted methods for quantitative determinations in vivo. In this study, we describe an application of dual x-ray absorptiometry (DXA) for measuring bone mineral content and bone mineral density in the proximal femur following THA. DXA is a noninvasive technique with minimal radiation exposure (< 5 mrem). Various aspects of measurement error (accuracy and reliability) of this application of DXA were determined in a series of studies reported here. Accuracy error (how similar are the measured and actual values) was < 1% determined in bone phantoms of four densities. Precision error (how reproducible are the measurements) was also < 1% at all four densities in the phantoms and was only slightly elevated (0.9-1.5%) in repeated measurements of implanted cadaver femora. Precision error in vivo, determined both from multiple replicates on five patients and from duplicate scans on 30 patients, was further elevated but remained < 5%. Contributions to precision error, rotation of the leg, and interoperator variability were assessed; none was found to elevate precision error appreciably. We suggest that DXA is a feasible method for quantifying bone response following THA, and will allow discrimination of small changes (> 5%) not previously measurable. 相似文献
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rCBF SPECT investigations with 99mTc-HMPAO were performed in 22 completed ischemic stroke patients on average 2.5, 16.8 and 38.0 days after stroke onset. As control group, 12 neurologically healthy volunteers were examined with the same method. The overall sensitivity of the rCBF SPECT method in the detection of cerebral blood flow abnormalities was 91%, with a specificity of 83% and an accuracy of 88%. The rCBF study was highly effective, particularly in the acute phase of the disease. Regional increased tracer uptake or a false normal 99mTc-HMPAO distribution due to the developing hyperemia mostly complicated the rCBF image interpretations in the subacute period. In the chronic phase, the spatial resolution of the SPECT system limited the detection of the continuously retracted stroke lesions. 相似文献
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Immunoglobulin G from subacute sclerosing panencephalitis brain as an immunological reagent.
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M L Weil E Norrby H H Itabashi R Wilson W W Tourtellotte D C Heiner 《Infection and immunity》1979,24(1):202-210
"Natural" hemagglutinin titers against a panel of fixed erythrocyte antigens were determined for groups of Minnesota miniature swine reared conventionally, in a specific pathogen-free facility, and in germfree isolators. Sera were assayed for hemagglutination (HA) titers by the microtiter method against 12 species of erythrocytes stabilized by treatment with pyruvic aldehyde and formaldehyde. These erythrocytes were stable for up to 2 years and gave slightly enhanced HA titers as compared to fresh, unfixed erythrocytes. Of the sera from conventional swine tested, the highest "natural" HA titers were directed towards rabbit, cat, swine dog, and burro erythrocytes (greater than 1:1,000), intermediate titers were detected against human A, B, and O, and sheep, pig, and chicken erythrocytes (1:64 to 1:1,000), whereas the lowest titers were found against ox and goat erythrocytes (less than 1:8). Titers obtained with sera from specific pathogen-free swine were 2- to 16-fold lower than those of conventional swine, but were of a similar distribution with regard to the species of erythrocyte tested. Germfree swine sera uniformly exhibited HA titers less than 1:4 against all species of erythrocytes. The majority of these hemagglutinins were immunoglobulin M class but there were some agglutinins of immunoglobulin A class and a slight amount of immunoglobulin G class. Specificity of these agglutinins was examined by absorption tests. The results are consistent with the hypothesis that natural hemagglutinins develop due to dietary or microbial antigenic stimulation, or both. 相似文献
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Panda S Kumar MS Lokabiraman S Jayashree K Satagopan MC Solomon S Rao UA Rangaiyan G Flessenkaemper S Grosskurth H Gupte MD 《Journal of acquired immune deficiency syndromes (1999)》2005,39(1):9-15
OBJECTIVES: Determining HIV prevalence in injection drug users (IDUs) and their regular sex partners in Chennai, India. METHODS: A total of 226 IDUs and their regular sex partners were enrolled during April-July 2003. After informed consent was obtained, a semistructured questionnaire was administered and serum was tested for HIV antibody. RESULTS: The HIV seroprevalence was 30% (68/226) in IDUs and 5% in their regular sex partners (11/226). While in 25% of couples only the male partner was HIV positive, 5% of the couples were concordant for HIV infection and 70% were HIV negative. Fifty-seven percent of the HIV-positive IDUs and 45% of the HIV-infected women thought that they had "no chance" or "very little chance" of getting HIV, reflecting low HIV risk perception. More than 20% IDUs reported borrowing or lending of injection equipment. In univariate analyses "sex" and "condom use" with sex workers had no bearing but "more than twice a day injecting frequency," "history of incarceration," "tattoos," "recruitment from northern part of the city," and ever-injecting drugs in drug-selling places had significant association with HIV infection in IDUs. In an adjusted model, the odds of HIV infection were 2 times higher among IDUs who had ever injected drugs in drug-selling places and 6 times higher in those who were recruited from the northern part of central Chennai. CONCLUSION: Reducing sharing of injection equipment and unsafe tattooing through targeted and environmental interventions, increasing HIV risk perception, and promoting safer sex practices among IDUs and their sex partners are urgent program needs. 相似文献
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Weigmann HJ Jacobi U Antoniou C Tsikrikas GN Wendel V Rapp C Gers-Barlag H Sterry W Lademann J 《Journal of biomedical optics》2005,10(1):14009
Penetration profiles of topically applied drugs and cosmetic products provide important information on their efficacy. The application of tape stripping in combination with UV/VIS spectroscopy is checked to determine the local position of topically applied substances inside the stratum corneum, the penetration profile. The amount of corneocytes removed with each tape strip is quantified via the particle-dependent absorption, the pseudoabsorption, in the visible spectral range. The concentration of a typical UV filter substance, 4-methylbenzylidene camphor, is determined by optical spectroscopy using the tape strips removed originally. In this case, a time-dependent increase in the absorbance must be taken into account. Laser scanning microscopic investigations confirm that the nonhomogeneous distribution of the filter substance, on the strips, can explain this spectroscopic behavior. When reaching a homogeneous distribution, the UV spectroscopic signal reflects the correct concentration. These spectroscopic values are compared with high performance liquid chromatography (HPLC) data. The values obtained with both methods for the concentrations of 4-methylbenzylidene camphor are in good agreement. The data obtained are used to illustrate the determination of a penetration profile of a UV filter substance. The results demonstrate that the described protocol is well suited to characterize, in a simple manner, topically applied substances that have a characteristic UV/VIS absorption band. 相似文献