|An Immunohistochemical Study of Feline Myocardial Fibrosis. |
Aupperle H, Baldauf K, März I
J Comp Pathol
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The aim of the present study was to investigate the pathology of feline myocardial fibrosis. The hearts from 40 cats with myocardial fibrosis were compared with the hearts from 25 normal cats. Clinical data were available in 11 cases. Hearts with myocardial fibrosis were hypomotile and there were hyperechoic areas in the ventricular wall on echocardiography. The presence of myocardial fibrosis was correlated significantly with hypertrophy of the ventricles, atrial dilation and angiosclerosis. Immunohistochemical studies demonstrated that normal feline cardiomyocytes expressed matrix metalloproteinase (MMP)-2, MMP-9, MMP-14, tissue inhibitor of matrix metalloproteinase (TIMP)-2 and transforming growth factor (TGF)-β2. Fibroblasts in normal hearts expressed only TIMP-2. In the hearts with myocardial fibrosis, expression of MMP-2, TIMP-3 and TGF-β2 by cardiomyocytes was significantly increased, but TIMP-2 expression was diminished. Fibroblasts in the affected hearts showed expression of MMP-14 in several cases. These findings suggest that a complex fibrotic remodelling of the feline myocardium occurs in this disease and that cardiomyocytes are involved in this process.Copyright © 2010 Elsevier Ltd. All rights reserved.
|High prevalence of ST131 isolates producing CTX-M-15 and CTX-M-14 among extended-spectrum-beta-lactamase-producing Escherichia coli isolates from Canada. |
Peirano G, Richardson D, Nigrin J, McGeer A, Loo V, Toye B, Alfa M, Pienaar C, Kibsey P, Pitout JD
Antimicrob Agents Chemother
1327-30. Epub 2010 Jan 4.
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Phenotypic and genotypic methods were used to characterize extended-spectrum-beta-lactamase (ESBL)-producing Escherichia coli isolated in 2007 from 11 different Canadian medical centers. Of the 209 ESBL-producing E. coli isolates tested, 148 (71%) produced CTX-M-15, 17 (8%) produced CTX-M-14, 5 (2%) produced CTX-M-3, and 1 produced CTX-M-27. Overall, 96 (46%) of the ESBL producers belonged to clonal complex ST131, with the highest prevalence in Brampton, Calgary, and Winnipeg. ST131 is an important cause of community onset urinary tract infections due to ESBL-producing E. coli across Canada.Testo completo dell'articolo
|Urinary biomarkers predict brain tumor presence and response to therapy. |
Edward R Smith, David Zurakowski, Ali Saad, R Michael Scott, Marsha A Moses
Clinical cancer research : an official journal of the American Association for Cancer Research
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PURPOSE: A major difficulty in treating brain tumors is the lack of effective methods of identifying novel or recurrent disease. In this study, we have evaluated the efficacy of urinary matrix metalloproteinases (MMP) as diagnostic biomarkers for brain tumors. EXPERIMENTAL DESIGN: Urine, cerebrospinal fluid, and tissue specimens were collected from patients with brain tumors. Zymography, ELISA, and immunohistochemistry were used to characterize the presence of MMP-2, MMP-9, MMP-9/neutrophil gelatinase-associated lipocalin (NGAL), and vascular endothelial growth factor (VEGF). Results were compared between age- and sex-matched controls and subjected to univariate and multivariate statistical analyses. RESULTS: Evaluation of a specific panel of urinary biomarkers by ELISA showed significant elevations of MMP-2, MMP-9, MMP-9/NGAL, and VEGF (all P 0.001) in samples from brain tumor patients compared with controls. Multiplexing MMP-2 and VEGF provided superior accuracy compared with any other combination or individual biomarker. Receiver-operating characteristics curves for MMP-2 and VEGF showed excellent discrimination. Immunohistochemistry identified these same proteins in the source tumor tissue. A subset of patients with longitudinal follow-up revealed subsequent clearing of biomarkers after tumor resection. CONCLUSION: We report, for the first time, the identification of a panel of urinary biomarkers that predicts the presence of brain tumors. These biomarkers correlate with presence of disease, decrease with treatment, and can be tracked from source tissue to urine. These data support the hypothesis that urinary MMPs and associated proteins are useful predictors of the presence of brain tumors and may provide a basis for a novel, noninvasive method to identify new brain tumors and monitor known tumors after treatment.
|Involvement of MMPs in the outward remodeling of collateral mesenteric arteries. |
Tara L Haas, Jennifer L Doyle, Matthew R Distasi, Laura E Norton, Kevin M Sheridan, Joseph L Unthank
American journal of physiology. Heart and circulatory physiology
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Persistent elevation in shear stress within conduit or resistance arteries causes structural luminal expansion, which serves to normalize shear stress while maintaining increased flow to the downstream vasculature. Although it is known that this adaptation involves cellular proliferation and remodeling of the extracellular matrix, the specific cellular events underlying these responses are poorly understood. Matrix metalloproteinases (MMPs) contribute to extensive remodeling of the extracellular matrix in conduit vessels and vein grafts exposed to high flow. However, involvement of MMPs in remodeling of small muscular collateral arteries, which are exposed to less severe increases in shear stress, has not been tested. We utilized an established model of outward remodeling in mesenteric collateral arteries to determine whether MMPs were upregulated during the remodeling response and to test whether MMP activity was required for luminal expansion. By 4 days, MMP-2 and membrane type 1 MMP (MT1-MMP), but not MMP-9, protein levels were significantly elevated in collateral arteries, as assessed by gelatin zymography and immunostaining. MMP-2 and MT1-MMP proteins, together with their respective transcriptional activators c-Jun and Egr-1 were localized predominantly to the smooth muscle layer of the collateral arteries. The general MMP inhibitor doxycycline prevented luminal expansion of collateral arteries but did not affect the endothelial cell proliferative or medial growth responses. In conclusion, this study provides evidence that MMP-2 and MT1-MMP are upregulated in collateral arteries exposed to elevated shear stress and that MMP activity is essential for the full remodeling response that leads to outward luminal expansion.