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81.
Rensink AA Otte-Höller I de Boer R Bosch RR ten Donkelaar HJ de Waal RM Verbeek MM Kremer B 《Neurobiology of aging》2004,25(1):93-103
Amyloid-beta (Abeta) deposition in the cerebral arterial and capillary walls is one of the characteristics of Alzheimer's disease and hereditary cerebral hemorrhage with amyloidosis-Dutch type. In vitro, Abeta1-40, carrying the "Dutch" mutation (DAbeta1-40), induced reproducible degeneration of cultured human brain pericytes (HBP), by forming fibrils at the cell surface. Thus, this culture system provides an useful model to study the vascular pathology seen in Alzheimer's disease. In this study, we used this model to investigate the effects of insulin on Abeta-induced degeneration of HBP, as it has been mentioned previously that insulin is able to protect neurons against Abeta-induced cell-death. The toxic effect of DAbeta1-40 on HBP was inhibited by insulin in a dose-dependent matter. Insulin interacted with Abeta and inhibited fibril formation of Abeta in a cell-free assay, as well as at the cell surface of HBP. Our data indicate that the formation of a fibril network is essential for Abeta-induced cell death in HBP. Additionally, insulin may be involved in the regulation of Abeta fibrillization in AD. 相似文献
82.
Cloning and Sequencing of a Candida albicans Catalase Gene and Effects of Disruption of This Gene 总被引:7,自引:0,他引:7
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Deborah R. Wysong Laurent Christin Alan M. Sugar Phillips W. Robbins Richard D. Diamond 《Infection and immunity》1998,66(5):1953-1961
Catalase plays a key role as an antioxidant, protecting aerobic organisms from the toxic effects of hydrogen peroxide, and in some cases has been postulated to be a virulence factor. To help elucidate the function of catalase in Candida albicans, a single C. albicans-derived catalase gene, designated CAT1, was isolated and cloned. Degenerate PCR primers based on highly conserved areas of other fungal catalase genes were used to amplify a 411-bp product from genomic DNA of C. albicans ATCC 10261. By using this product as a probe, catalase clones were isolated from genomic libraries of C. albicans. Nucleotide sequence analysis revealed an open reading frame encoding a protein of 487 amino acid residues. Construction of a CAT1-deficient mutant was achieved by using the Ura-blaster technique for sequential disruption of multiple alleles by integrative transformation using URA3 as a selectable marker. Resulting mutants exhibited normal morphology and comparable growth rates of both yeast and mycelial forms. Enzymatic analysis revealed an abundance of catalase in the wild-type strain but decreasing catalase activity in heterozygous mutants and no detectable catalase in a homozygous null mutant. In vitro assays showed the mutant strains to be more sensitive to damage by both neutrophils and concentrations of exogenous peroxide that were sublethal for the parental strain. Compared to the parental strain, the homozygous null mutant strain was far less virulent for mice in an intravenous infection model of disseminated candidiasis. Definitive linkage of CAT1 with virulence would require restoration of activity by reintroduction of the gene into mutants. However, initial results in mice, taken together with the enhanced susceptibility of catalase-deficient hyphae to damage by human neutrophils, suggest that catalase may enhance the pathogenicity of C. albicans. 相似文献
83.
dit Faute MA Laurent L Ploton D Poupon MF Jardillier JC Bobichon H 《Clinical & experimental metastasis》2002,19(2):161-168
Growth of human tumor cells as three-dimensional (3D) multicellular spheroids modifies their invasive properties. Here we study the differences in the biological features of MCF-7, a human breast cancer cell line, and its multidrug resistant variant (MDR-MCF-7) cultured as spheroids or as monolayers. Three-dimensional culture decreased the proliferative rate of both cell lines, reduced the drug sensitivity of MCF-7 cells and did not affect the resistance of MDR-MCF-7 cells. Transmission electron microscopic studies and intercellular junctions labeling showed that MCF-7 spheroids had a junctional system involving E-cadherin, tight-junctions and desmosomes. In MDR-MCF-7 cell spheroids, cell cohesion was mostly due to membrane interdigitations. MDR-MCF-7 cells, but not their parental counterpart, displayed a higher invasive potential when cultured as spheroids, as shown in the Boyden chamber assay. 3D-induced invasiveness was correlated with serine protease and plasminogen activator (PA) secretion. MCF-7 cells did not show any tendency to invade, whatever the mode of culture. These results show that 3D-cultures as spheroids distinctively altered structural features of parental and MDR-MCF-7 cells. In MCF-7 cells, 3D-culture increased cell-cell contacts and drug resistance; in MDR-MCF-7 cells, it induced invasive properties. 相似文献
84.
Verhaak CM Smeenk JM Evers AW van Minnen A Kremer JA Kraaimaat FW 《Journal of behavioral medicine》2005,28(2):181-190
The predictive value of a comprehensive model with personality characteristics, stressor related cognitions, coping and social support was tested in a sample of 187 nonpregnant women. The emotional response to the unsuccessful treatment was predicted out of vulnerability factors assessed before the start of the treatment. The results indicated the importance of neuroticism as a vulnerability factor in emotional response to a severe stressor. They also underlined the importance of helplessness and marital dissatisfaction as additional risk factors, and acceptance and perceived social support as additional protective factors, in the development of anxiety and depression after a failed fertility treatment. From clinical point of view, these results suggest fertility-related cognitions and social support should receive attention when counselling women undergoing IVF or ICSI treatment. 相似文献
85.
Immunodetection of apoptosis-regulating proteins in lymphomas from patients with and without human immunodeficiency virus infection. 总被引:5,自引:2,他引:5
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D. Schlaifer S. Krajewski S. Galoin F. Rigal-Huguet G. Laurent P. Massip J. Pris G. Delsol J. C. Reed P. Brousset 《The American journal of pathology》1996,149(1):177-185
The expression of the apoptosis-regulating genes Bcl-2, Bcl-x, Bax, Mcl-1, and p53 analyzed in 4 cases of human immunodeficiency virus (HIV)-associated Hodgkin's disease, in 36 cases of HIV-related non-Hodgkin's lymphomas (NHLs), and in 109 cases of non-HIV-related NHLs by using immunohistochemistry. HIV-associated Hodgkin's disease samples were positive for all markers. For the HIV-related NHL samples, 36, 66, 88, 100, and 94% of the cases were Bcl-2, Bcl-x, Bax, Mcl-1, and p53 were found to be expressed in 69, 65, 82, 83, and 42%, respectively. No significant differences were observed in Bax and Mcl-1 staining between HIV-unrelated NHLs of B cell and T cell types. In contrast, Bcl-2 was positive in 66/79 (83%) and 10/30 (33%) of B cell and T cell HIV-unrelated NHLs, respectively (P2 < 0.001). Peculiar patterns were observed for hairy cell leukemia (Bax+, Bcl-2+, Mcl-1-) and for anaplastic large cell lymphoma (Bax+, Mcl-1+, Bcl-2-) in HIV-unrelated NHLs. Of interest, all cases with a positive expression of Bax were also found to express either Mcl-1 and/or Bcl-2, suggesting that Mcl-1 and Bcl-2 may counteract the pro-apoptosis function of Bax in vivo by protein-protein interaction within the tumor cell, as demonstrated previously in vitro. These results suggest that apoptosis regulation may have a role in the pathogenesis of some HIV-related and HIV-unrelated NHLs. 相似文献
86.
Tissue injury and repair in the rat kidney after exposure to cisplatin or carboplatin 总被引:2,自引:0,他引:2
D Nonclercq G Toubeau G Laurent P M Tulkens J A Heuson-Stiennon 《Experimental and molecular pathology》1989,51(2):123-140
Cisplatin (cis-diamminedichloroplatinum II) has emerged as an anticancer drug of considerable value for the chemotherapy of several human neoplasms. However, this agent often causes renal toxicity, which appears to be the dose-limiting untoward effect. The present animal study was undertaken to compare, with regard to kidney injury and renal tissue repair, cisplatin and carboplatin (cis-diammine-1,1-cyclobutane dicarboxylate platinum II), a platinum derivative more recently introduced in clinics. Female Sprague-Dawley rats (four animals per group) were treated ip with cisplatin (4 or 8 mg/kg, delivered in four consecutive daily injections) or carboplatin (40 mg/kg given in one injection) and terminated 4, 7, and 21 days after drug administration. One hour prior to sacrifice, each animal received ip 200 microCi of [3H]thymidine for the measurement of DNA synthesis and cell proliferation (frequency of S-phase cells in renal tissue, determined by histoautoradiography). Cisplatin, particularly at 8 mg/kg, caused severe tubular injury (acute tubular necrosis) culminating in a long-lasting cystic tubular dilatation in the outer stripe of outer medulla. Tubular damage was followed by a sharp proliferative response, indicative of tubular regeneration. However, the proliferative activity was still above basal level at the end of the observation period, suggesting that the tissue repair process had not reached completeness 3 weeks after cisplatin administration. In contrast, carboplatin only induced focal tubular necrosis in proximal tubules. Distal and collecting tubules also showed ultrastructural evidence of hydropic degeneration after exposure to the latter drug. Renal tubular injury associated with carboplatin was followed by a mild proliferative response. From this study, we can infer that carboplatin is less nephrotoxic than cisplatin, but still causes histopathological alterations in renal tissue. Furthermore, the lesser nephrotoxicity of carboplatin has a primary origin and is not due to a more efficient tissue repair reaction. 相似文献
87.
Platteau P Laurent E Albano C Osmanagaoglu K Vernaeve V Tournaye H Camus M Van Steirteghem A Devroey P 《Human reproduction (Oxford, England)》2003,18(6):1200-1204
BACKGROUND: A pen device, similar to an insulin pen, has been recently marketed for the administration of follitropin beta in cartridges. A randomized controlled trial was performed to compare the efficacy and convenience of this pen device delivering follitropin beta with a conventional syringe delivering follitropin alpha. METHODS: A total of 200 patients needing IVF/ICSI treatment and willing to self-inject were enrolled in the study. All subjects had ovarian stimulation according to a long protocol and were randomized to the pen or the conventional syringe group during down-regulation by means of a computer-generated randomization list using random numbers. Patients were asked to fill in a daily local tolerance book after each injection. On the day of hCG the patients scored a Visual Analogue Scale (VAS) for pain and convenience. RESULTS: The average duration, total dose of recombinant FSH and number of cumulus oocyte complexes retrieved were 10.8/12.0 days (P = 0.001), 1880/2226 IU (P < 0.001) and 15.2/13.1 respectively in the pen device and conventional syringe groups; the presence of pain after the daily injection was significantly higher in the conventional syringe group (P = 0.027); the visual analogue scale score was similar for pain but significantly more convenient for the pen device (P < 0.001). The live birth rate per embryo transfer was 32.9 and 34.4% respectively in the pen device and conventional syringe groups. CONCLUSIONS: Self-injection with the pen device is safe and easy, more convenient and less painful for the patient, requires less FSH and shortens the treatment duration. 相似文献
88.
Global expression profiling of fibroblast responses to transforming growth factor-beta1 reveals the induction of inhibitor of differentiation-1 and provides evidence of smooth muscle cell phenotypic switching 总被引:1,自引:0,他引:1
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Chambers RC Leoni P Kaminski N Laurent GJ Heller RA 《The American journal of pathology》2003,162(2):533-546
89.
Discriminatory power and reproducibility of novel DNA typing methods for Mycobacterium tuberculosis complex strains
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Kremer K Arnold C Cataldi A Gutiérrez MC Haas WH Panaiotov S Skuce RA Supply P van der Zanden AG van Soolingen D 《Journal of clinical microbiology》2005,43(11):5628-5638
In recent years various novel DNA typing methods have been developed which are faster and easier to perform than the current internationally standardized IS6110 restriction fragment length polymorphism typing method. However, there has been no overview of the utility of these novel typing methods, and it is largely unknown how they compare to previously published methods. In this study, the discriminative power and reproducibility of nine recently described PCR-based typing methods for Mycobacterium tuberculosis were investigated using the strain collection of the interlaboratory study of Kremer et al. This strain collection contains 90 M. tuberculosis complex and 10 non-M. tuberculosis complex mycobacterial strains, as well as 31 duplicated DNA samples to assess reproducibility. The highest reproducibility was found with variable numbers of tandem repeat typing using mycobacterial interspersed repetitive units (MIRU VNTR) and fast ligation-mediated PCR (FLiP), followed by second-generation spoligotyping, ligation-mediated PCR (LM-PCR), VNTR typing using five repeat loci identified at the Queens University of Belfast (QUB VNTR), and the Amadio speciation PCR. Poor reproducibility was associated with fluorescent amplified fragment length polymorphism typing, which was performed in three different laboratories. The methods were ordered from highest discrimination to lowest by the Hunter-Gaston discriminative index as follows: QUB VNTR typing, MIRU VNTR typing, FLiP, LM-PCR, and spoligotyping. We conclude that both VNTR typing methods and FLiP typing are rapid, highly reliable, and discriminative epidemiological typing methods for M. tuberculosis and that VNTR typing is the epidemiological typing method of choice for the near future. 相似文献
90.