Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Four weeks of immobilisation with two types of re-mobilisation programmes (intensive concentric treadmill exercising during 6 days, and free exercising, and immobilisation without any re-mobilisation period were studied to clarify possible exercise-induced calf muscle damage especially in fast-twitch fibres used in running compared to non-immobilised rats housing freely in their cages. As markers of muscle injury, conventional histology, beta-glucuronidase (beta-GU) activity and fetal myosin heavy chain expression (MHC-d) were assessed on Days 0, 1, 3, 6 and 14 after the cast removal. Only minor focal hypercontraction, ruptures and necrosis of myofibrils, and weak inflammatory cell reactions were found in all samples examined, except in the controls. No MHC-d positive cells were found indicating absence of active regeneration after immobilisation or re-mobilisation. Minor increase in beta-GU activity was observed in all three muscles studied, but statistically significant increase was observed only in the samples of the free exercising group on Day 14 after the cast removal. To conclude, intensive concentric treadmill exercise for 6 days did not cause significantly more muscle damage than did free exercising re-mobilisation.
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PMID:Recovery from immobilisation: responses of fast-twitch muscle fibres to spontaneous and intensive exercise in rat calf muscles. 1517 11

One method of nonviral-based gene therapy is to implant microencapsulated nonautologous cells genetically engineered to secrete the desired gene products. Encapsulating the cells within a biocompatible permselective hydrogel, such as alginate-poly-L-lysine-alginate (APA), protects the foreign cells from the host immune system while allowing diffusion of nutrients and the therapeutic gene products. An important consideration is which kind of cells is the best candidate for long-term implantation. Our previous work has shown that proliferation and differentiation of encapsulated C2C12 myoblasts in vitro are significantly improved by inclusion of basic fibroblast growth factor (bFGF), insulin growth factor II (IGF-II), and collagen within the microcapsules ("enhanced" capsules). However, the effects of such inclusions on the functional status of the microcapsules in vivo are unknown. Here we found that comparing the standard with the enhanced APA microcapsules; there was no difference in the rates of diffusion of recombinant products of different sizes, that is, human factor IX (FIX, 65 kDa), murine IgG (150 kDa), and a lysosomal enzyme, beta-glucuronidase (300 kDa), thus providing a key requirement of such an immunoprotective device. Furthermore, the creatine phosphokinase activity and myosin heavy chain staining (markers for differentiation of the myoblasts) and the cell number per capsule in the enhanced microcapsules indicated a higher degree of differentiation and proliferation when compared to the standard microcapsules, thus demonstrating an improved microenvironment for the encapsulated cells. Efficacy was tested in a melanoma cancer tumor model by treating tumor induced by B16-F0/neu tumor cells in mice with myoblasts secreting angiostatin from either the standard or enhanced APA microcapsules. Mice treated with enhanced APA-microcapsules had an 80% reduction in tumor volume at day 21 compared to a 70% reduction in those treated with standard APA-microcapsules. In conclusion, enhancement of APA microcapsules with growth factors and collagen did not adversely affect their permeability property and therapeutic efficacy. However, the enhanced differentiation and viability of the encapsulated myoblasts in vivo should be advantageous for long-term delivery with this method of gene therapy.
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PMID:Enhancement of myoblast microencapsulation for gene therapy. 1647 Aug 9