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排序方式: 共有2095条查询结果,搜索用时 62 毫秒
1.
Distinct genetic alterations and luminal molecular subtype in nested variant of urothelial carcinoma
2.
Joerg Lindenmann Veronika Matzi Alfred Maier Freyja-Maria Smolle-Juettner 《European journal of cardio-thoracic surgery》2007,31(2):322-324
We report a pitfall deriving from the assumption of metastatic disease based upon seemingly identical histology in a pulmonary lesion and in the esophagus. In a 60-year-old patient, cT1 esophageal squamous cell carcinoma was found. One of the two pulmonary nodules was histologically diagnosed as metastasis. When esophageal perforation occurred during palliative therapy, esophagectomy became necessary together with the right lower lobectomy for the removal of the remaining pulmonary lesion. Definitive histology showed pT1N0 cancer of the esophagus, primary esophageal sarcoma and pT4N0 bronchogenic carcinoma. The other pulmonary lesion was re-evaluated and defined as intralobar M1 of bronchogenic carcinoma. 相似文献
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Amyloid fibril formation by human stefin B: influence of pH and TFE on fibril growth and morphology.
Eva Zerovnik Miha Skarabot Katja Skerget Silva Giannini Veronika Stoka Sasa Jenko-Kokalj Rosemary A Staniforth 《Amyloid》2007,14(3):237-247
As shown before, human stefin B (cystatin B) populates two partly unfolded species, a native-like state at pH 4.8 and a structured molten globule state at pH 3.3 (high ionic strength), from each of which amyloid fibrils grow. Here, we show that the fibrils obtained at pH 3.3 differ from those at pH 4.8 and that those obtained at pH 3.3 (protofibrils) do not transform readily to mature fibrils. In addition we show that amorphous aggregates are also a source of fibrils. The kinetics of amyloid fibril formation at different trifluoroethanol (TFE) concentrations were measured. TFE accelerates fibril growth at predenaturational concentrations of the alcohol. At concentrations higher than 10%, the fibrillar yield decreases proportionately as the population of an all alpha-helical, denatured form of the protein increases. At an optimum TFE concentration, the lag and the growth phases are observed, similarly to some other amyloidogenic proteins. Morphology of the protein species at the beginning and the end of the reactions was observed using atomic force microscopy and transmission electron microscopy. Final fibril morphologies differ depending on solvent conditions. 相似文献
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7.
Veronika Apprich Joachim Spergser Renate Rosengarten Christian Stanek 《Medical mycology》2006,44(8):715-722
The effects of two dermatophytes (Microsporum gypseum and Trichophyton mentagrophytes) and four moulds (Scopulariopsis brevicaulis, Alternaria alternata, Geotrichum candidum and Penicillium spp.) on living keratinocyte cultures were examined in vitro using primary human keratinocytes. Rates of apoptosis of infected cells were determined using a colorimetric TUNEL system which detects the characteristic nuclear DNA fragmentation of apoptotic cells. The cytotoxicity of the individual fungi was tested by quantitatively measuring cytosolic enzyme lactate dehydrogenase, released upon cell lysis, in culture supernatants. Additionally, the cell structures within the infected keratinocytes in cultures were examined by scanning electron microscopy. All of the fungi exhibited high cytotoxicity, whereas the development of only the two dermatophytes and the mould Scopulariopsis brevicaulis resulted in distinctly increased apoptosis. Electron microscopy showed that all fungi studied caused similar alterations in the cell structure, with Microsporum gypseum being the most harmful. Increasing loss of cell adhesion as a consequence of a decreasing number of reticulating cell appendices and a reduced cell plasticity were the most evident alterations. 相似文献
8.
Michael M. Morlock Veronika Bonin Gerd Müller Erich Schneider 《European journal of applied physiology》1997,76(1):75-80
This study was designed to investigate the relationship between trunk muscle fatigue and associated changes in the electromyographic (EMG) signals during a dynamic iso-inertial test. Eleven subjects performed dynamic trunk flexion/extension movements against 40% maximum voluntary contraction (MVC) torque until exhaustion in a tri-axial trunk dynamometer. EMG parameters in the time and frequency domain were studied by analysing changes of the signal amplitudes and the spectral density (using the zero-crossing-rate and the median frequency). The kinematics of the movement were analysed according to the movement velocities and the deviations from the required movement plane. The flexion and extension velocities decreased from the beginning to the end of the test. Movement deviations from the sagittal plane into the frontal and transverse plane increased with increasing test duration, as did the EMG amplitude. The median frequency during periods with maximum muscle activity decreased, as did the zero-crossing-rate. The increase in amplitude and decrease in median frequency were more pronounced in the trunk flexors than in the trunk extensors. The parameters of median frequency, zero-crossing-rate and amplitude seem to be sensitive identifiers of muscle fatigue during well-controlled dynamic contractions. While the kinematic data did not yield any information on the mechanisms of the fatigue, changes in the EMG parameters demonstrated that the duration of the test was limited by the fatigue of the trunk flexors. 相似文献
9.
Parenting stress and parental bonding 总被引:2,自引:0,他引:2
Willinger U Diendorfer-Radner G Willnauer R Jörgl G Hager V 《Behavioral medicine (Washington, D.C.)》2005,31(2):63-69
Attachment experiences are thought to be important because of their implications for later development. The authors' aim with the questionnaire-based study was to investigate the differences between recalled parental bonding regarding 4 types of maternal and paternal bonding with respect to experienced parenting stress caused by child characteristics, parent attributes, and life events under the consideration of the child's gender and age. The authors gathered parental bonding behavior data with the German version of the Parental Bonding Instrument (PBI). The authors assessed parenting stress with their German version of the "Parenting Stress Index (PSI)." They found significant differences among 120 mothers grouped in the 4 maternal and the 4 paternal bonding types regarding parenting stress caused by child, maternal bonding: F(5, 113) = 4.13, p = .002, paternal bonding: F(5, 111) = 8.50, p < or = .0001, and parent characteristics, maternal bonding: F(5, 113) = 3.33, p = .008, paternal bonding: F(5, 111) = 7.80, p < or = .0001. The lowest level of parenting stress was experienced by mothers who themselves recalled the "optimal parental bonding type" with respect to the child and parental domain. The authors did not find any significant differences between the 4 maternal, F(5, 113) = 1.25, p = .29, and the 4 paternal, F(5, 111) = 1.87, p = .106, bonding types with respect to the life stress. According to the authors' findings, the representation of attachment relationships seems to have a special impact on the adult's capacity to cope with challenges and stress, either directly or indirectly as an internal working model of attachment. For the clinical practice, these findings seem to recommend the combination of both the PSI and PBI regarding the diagnostic of stressful mother-child system to plan an optimal intervention program. 相似文献
10.
Volcik KA Blanton SH Tyerman GH Jong ST Rott EJ Page TZ Romaine NK Northrup H 《American journal of medical genetics》2000,95(1):21-27
The C677T and A1298C mutations in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene are each associated with reduced MTHFR activity. The C677T mutation in the heterozygous and homozygous state correlates with increased enzyme thermolability, with homozygous mutant genotypes showing significantly elevated plasma homocysteine levels and decreased plasma folate levels. The A1298C mutation results in decreased MTHFR activity, but changes in neither homocysteine nor folate levels are associated with A1298C variant genotypes. Our study determined the frequencies of the C677T and A1298C MTHFR mutations for spina bifida (SB) cases, mothers and fathers of SB cases, and controls in Hispanics of Mexican-American descent. In addition, our subject population was further categorized as to whether the spina bifida lesion occurred as an upper or lower level defect, according to the Van Allen "multi-site closure" model. Hispanic SB cases with upper level defects and their mothers were homozygous for the C677T variant allele at a higher rate than their respective controls (OR = 1.5 [95% CI 0.8-2.9], P = 0.30; OR = 2.3 [1.1-4.8], P = 0.04, respectively), with statistically significant results seen only for the maternal homozygous genotype. Homozygosity for the A1298C mutation was seen at a higher rate only in Hispanic mothers of both upper and lower level SB cases when compared to controls, but these results were not statistically significant. Our study provides evidence that the maternal C677T MTHFR homozygous mutant genotype is a risk factor for upper level spina bifida defects in Hispanics. 相似文献