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31.
A mouse model of hepatocellular carcinoma: ectopic expression of fibroblast growth factor 19 in skeletal muscle of transgenic mice 下载免费PDF全文
Nicholes K Guillet S Tomlinson E Hillan K Wright B Frantz GD Pham TA Dillard-Telm L Tsai SP Stephan JP Stinson J Stewart T French DM 《The American journal of pathology》2002,160(6):2295-2307
Most mouse models of hepatocellular carcinoma have expressed growth factors and oncogenes under the control of a liver-specific promoter. In contrast, we describe here the formation of liver tumors in transgenic mice overexpressing human fibroblast growth factor 19 (FGF19) in skeletal muscle. FGF19 transgenic mice had elevated hepatic alpha-fetoprotein mRNA as early as 2 months of age, and hepatocellular carcinomas were evident by 10 months of age. Increased proliferation of pericentral hepatocytes was demonstrated by 5-bromo-2'-deoxyuridine incorporation in the FGF19 transgenic mice before tumor formation and in nontransgenic mice injected with recombinant FGF19 protein. Areas of small cell dysplasia were initially evident pericentrally, and dysplastic/neoplastic foci throughout the hepatic lobule were glutamine synthetase-positive, suggestive of a pericentral origin. Consistent with chronic activation of the Wingless/Wnt pathway, 44% of the hepatocellular tumors from FGF19 transgenic mice had nuclear staining for beta-catenin. Sequencing of the tumor DNA encoding beta-catenin revealed point mutations that resulted in amino acid substitutions. These findings suggest a previously unknown role for FGF19 in hepatocellular carcinomas. 相似文献
32.
Stéphanie Chasseigneaux Stéphane Haïk Isabelle Laffont-Proust Olivier De Marco Martine Lenne Jean-Philippe Brandel Jean-Jacques Hauw Jean-Louis Laplanche Katell Peoc’h 《Neuroscience letters》2006
A valine to isoleucine mutation at residue 180 was identified in a French patient with Creutzfeldt-Jakob disease (CJD). The mutation is located in the close vicinity of one of the two N-glycosylation sites of the cellular prion protein (PrPC). Western blot analysis revealed accumulation in the brain of the pathogenic proteinase K-resistant PrP (PrPSc) isoform with the notable absence of the diglycosylated band. The mutant protein expressed in CHO cells was correctly glycosylated, suggesting that the atypical glycosylation pattern of PrPSc was not due to the mutation at position 180. These results suggest that the diglycosylated form of the mutant PrP180I prevents its conversion into the pathogenic mutant form PrPSc180I, supporting a central role of N-linked glycan chains in the PrP conversion process. 相似文献
33.
What and where in human audition: selective deficits following focal hemispheric lesions 总被引:8,自引:0,他引:8
Clarke S Bellmann Thiran A Maeder P Adriani M Vernet O Regli L Cuisenaire O Thiran JP 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2002,147(1):8-15
A sound that we hear in a natural setting allows us to identify the sound source and localize it in space. The two aspects
can be disrupted independently as shown in a study of 15 patients with focal right-hemispheric lesions. Four patients were
normal in sound recognition but severely impaired in sound localization, whereas three other patients had difficulties in
recognizing sounds but localized them well. The lesions involved the inferior parietal and frontal cortices, and the superior
temporal gyrus in patients with selective sound localization deficit; and the temporal pole and anterior part of the fusiform,
inferior and middle temporal gyri in patients with selective recognition deficit. These results suggest separate cortical
processing pathways for auditory recognition and localization.
Electronic Publication 相似文献
34.
A. Gratas-Delamarche J. Mercier M. Ramonatxo J. Dassonville C. Préfaut 《European journal of applied physiology》1993,66(1):25-30
Summary The aim of this study was to determine whether the greater ventilation in children at rest and during exercise is related to a greater CO2 ventilatory response. The CO2 ventilatory response was measured in nine prepubertal boys [10.3 years (SD 0.1)] and in 10 adults [24.9 years (SD 0.8)] at rest and during moderate exercise (
CO2 = 20 ml·kg–1·min–1) using the CO2-rebreathing method. Three criteria were measured in all subjects to assess the ventilatory response to CO2: the CO2 sensitivity threshold (Th), which was defined as the value of end titalPCO2 (P
ETCO2) where the ventilation increased above its steady-state level; the reactivity slope expressed per unit of body mass (SBM), which was the slope of the linear relation between minute ventilation (
E) andP
ETCO2 above Th; and the slope of the relationship between the quotient of tidal volume (V
T) and inspiration time (t
I) andP
ETCO2 (V
T ·t
I
–1 ·P
ETCO2
–1) values above Th. The
E,V
T, breathing frequency (f
R), oxygen uptake (
O2), and CO2 production (
CO2) were also measured before the CO2-rebreathing test. The following results were obtained. First, children had greater ventilation per unit body weight than adults at rest (P<0.001) and during exercise (P<0.01). Second, at rest, onlyV
T ·t
I
–1 ·P
ETCO2
–1 was greater in children than in adults (P<0.001). Third, during exercise, children had a higher SBM (P < 0.02) andV
T ·t
I
–1 ·P
ETCO2
–1 (P<0.001) while Th was lower (P<0.02). Finally, no correlation was found between
E/
CO2 and Th while a significant correlation existed between
E/
CO2 and SBM (adults,r=0.79,P<0.01; children,r=0.73,P<0.05). We conclude that children have, mainly during exercise, a greater sensitivity of the respiratory centres than adult. This greater CO2 sensitivity could partly explain their higher ventilation during exercise, though greater CO2 production probably plays a role at rest. 相似文献
35.
Z. Taoutaou P. Granier B. Mercier J. Mercier S. Ahmaidi C. Prefaut 《European journal of applied physiology》1996,73(5):465-470
We investigated the effects of passive and partially active recovery on lactate removal after exhausting cycle ergometer exercise in endurance and sprint athletes. A group of 14 men, 7 endurance-trained (ET) and 7 sprint-trained (ST), performed two maximal incremental exercise tests followed by either passive recovery (20 min seated on cycle ergometer followed by 40 min more of seated rest) or partially active recovery [20 min of pedalling at 40% maximal oxygen uptake (
O2max) followed by 40 min of seated rest]. Venous blood samples were drawn at 5 min and 1 min prior to exercise, at the end of exercise, and during recovery at 1, 2, 3, 4, 5, 6, 8, 10, 15, 20, 30, 40, 50, 60 min post-exercise. The time course of changes in lactate concentration during the recovery phases were fitted by a bi-exponential time function to assess the velocity constant of the slowly decreasing component (2) expressing the rate of blood lactate removal. The results showed that at the end of maximal exercise and during the 1st min of recovery, ET showed higher blood lactate concentrations than ST. Furthermore, ET reached significantly higher maximal exercise intensities [5.1 (SEM 0.5) W · kg–1 vs 4.0 (SEM 0.3) W · kg–1,P < 0.05] and
O2max [68.4 (SEM 1.1) ml · kg–1 · min–1 vs 55.5 (SEM 5.1) ml · kg–1 · min–1,P < 0.01]. There was no significant difference between the two groups during passive recovery for 2 During partially active recovery, 2 was higher than during passive recovery for both groups (P < 0.001), but ET recovered faster and sooner than ST (P < 0.05). Compared to passive recovery, the 2 measured during partially active recovery was increased threefold in ET and only 1.5-fold in ST. We concluded that partially active recovery potentiates the enhanced ability to remove blood lactate induced by endurance training. 相似文献
36.
The collagen family represents the most abundant protein in animals. Type IV collagen ([alpha 1 (IV)]2 alpha 2 (IV)) differs from the other types in several respects and particularly in its distribution, being strictly limited to the basement membranes. Alterations in the structure and functions of basement membranes are observed in a number of diseases, such as tumoral angiogenesis and diabetic nephropathy. This article reviews current structural and pathophysiological knowledge concerning type IV collagen. 相似文献
37.
F. Anselme K. Collomp B. Mercier S. Ahmaïdi Ch. Prefaut 《European journal of applied physiology》1992,65(2):188-191
Summary The aim of this study was to specify the effects of caffeine on maximal anaerobic power (W
max). A group of 14 subjects ingested caffeine (250 mg) or placebo in random double-blind order. TheW
max was determined using a force-velocity exercise test. In addition, we measured blood lactate concentration for each load at the end of pedalling and after 5 min of recovery. We observed that caffeine increasedW
max [964 (SEM 65.77) W with caffeine vs 903.7 (SEM 52.62) W with placebo;P<0.02] and blood lactate concentration both at the end of pedalling [8.36 (SEM 0.95) mmol · l–1 with caffeine vs 7.17 (SEM 0.53) mmol · l–1 with placebo;P<0.011 and after 5 min of recovery [10.23 (SEM 0.97) mmol · l–1 with caffeine vs 8.35 (SEM 0.66) mmol · l–1 with placebo;P<0.04]. The quotient lactate concentration/power (mmol · l–1 · W–1) also increased with caffeine at the end of pedalling [7.6 · 10–3 (SEM 3.82 · 10–5) vs 6.85 · 10–3 (SEM 3.01 · 10–5);P<0.01] and after 5 min of recovery [9.82·10–3 (SEM 4.28 · 10–5) vs 8.84 · 10–3 (SEM 3.58 · 10–5);P<0.02]. We concluded that caffeine increased bothW
max and blood lactate concentration. 相似文献
38.
39.
Monosomy 9q and trisomy 16q in a case of congenital solitary infantile myofibromatosis 总被引:1,自引:0,他引:1
Sirvent N Perrin C Lacour JP Maire G Attias R Pedeutour F 《Virchows Archiv : an international journal of pathology》2004,445(5):537-540
Although infantile myofibromatosis (IM) is the most common fibrous proliferation of infancy, many aspects of this benign lesion have not been explored. IM histogenesis is still poorly understood, despite immunohistochemical staining and ultrastructural features that suggest a myofibroblastic origin. IM diagnosis is often made difficult by the predominance of small primitive spindle cells over myofibrobasts and the presence of intravascular growth. Genetic information is scarce, with only one karyotyped case. Here we describe a case of solitary IM discovered at birth in an otherwise healthy girl. The tumor was well circumscribed, arranged in nodules and made up of ovoid cells without atypia, in a myxoid background. Immunohistochemical evaluation indicated a myofibroblastic differentiation. The cytogenetic and fluorescence in situ hybridization analyses revealed an abnormal chromosome 9, derived from an unbalanced whole-arm translocation between chromosomes 9 and 16. On both chromosomes, the breakpoints were located in the pericentric heterochromatic region. This clonal abnormality has not been reported in other tumors and is different from the chromosome 6q deletion reported in the single previous reported IM karyotype. 相似文献
40.
Lefrère JJ Lerable J Mariotti M Bogard M Thibault V Frangeul L Loiseau P Bouchardeau F Laperche S Pawlotsky JM Cantaloube JF Biagini P de Lamballerie X Izopet J Defer C Lepot I Poveda JD Dussaix E Gerolami V Halfon P Buffet-Janvresse C Férec C Mercier B Marcellin P Martinot-Peignoux M Gassain M 《Journal of virological methods》2000,85(1-2):117-124
The aim of this study was to determine whether multicentre quality controls for the detectability of viral genomes could contribute to the improvement of diagnostic performance in the participating laboratories. The study was carried out during two successive rounds, during which 18 laboratories specialized in nucleic acid testing analyzed, through a polymerase chain reaction (PCR) assay, a common panel of GB virus C (GBV-C)/hepatitis G virus (HGV) RNA-positive and -negative samples. During the first round, the laboratories used either an 'in-house' PCR procedure or a partly standardized commercial test. After decoding the results of the first round, the procedures of the participating laboratories were compared in order to establish a consensus procedure deduced from those of the laboratories which provided the best results. During the second round, each participating laboratory could use the resulting consensus procedure, or its own procedure, or both. The results of this quality control study indicated that, whatever method used, even specialized and trained laboratories may give false-negative or false-positive results. The commercial assay did not guarantee a systematic high quality level of results. The striking heterogeneity of results observed among laboratories using the same commercial assay confirm that molecular biology methods need skilled technicians. The results of this quality control study suggest that full standardization of viral genome detection, including all steps of the procedure, is necessary and that the laboratories performing PCR should participate in repeated quality control studies, whatever technique is being used. 相似文献