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Fibrovascular Tissue (fibrovascular + tissue)
Selected AbstractsS/e-PTFE episcleral buckling implants: An experimental and histopathologic studyJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 6 2002B. Mortemousque Abstract To investigate tissue changes induced by the implantation of a silicone band coated with expanded polytetrafluoroethylene (S/e-PTFE) used as scleral buckling, an experimental and histopathological study was performed in rabbits. The right eyes of eight rabbits were implanted for 28,85 days with S/e-PTFE. No complications were encountered in any of the eyes, so histopathological examinations could be performed. Encapsulations combined with numerous giant cells were found to be surrounding the implants in seven eyes, and deposits from the mineral salts of calcium were found in three eyes, forming granulomas possibly caused by irregularities of the implant surface. The porous structure allowed a peripheral colonization by fibrovascular tissue. Taking into account the histological results, the use of this material does not appear suitable. However, this inflammation was limited and did not merge on surrounding tissues. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 686,691, 2002 [source] Evaluation of blood vessel ingrowth in fibrin gel subject to type and concentration of growth factorsJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 9a 2009A. Arkudas Abstract Our aim was to quantitatively assess the angiogenetic effects of VEGF and bFGF immobilized in a fibrin-based drug delivery system in a suitable subcutaneous rat model. After evaluation of a suitable implantation technique (6 rats), four teflon isolation chambers containing fibrin gel matrices were implanted subcutaneously in an upside-down fashion on the back of 30 Lewis rats. The matrices consisted of 500 ,l fibrin gel with two different fibrinogen concentrations (10 mg/ml or 40 mg/ml fibrinogen) and 2 I.U./ml thrombin and contained VEGF and bFGF in five different concentrations (0 to 250 ng/ml each). At 3, 7 and 14 days after implantation, matrices were explanted and subjected to histological and morphometrical analysis. At 1 week, the volume of the fibrin clots was significantly smaller in the 100 and 250 ng/ml VEGF and bFGF groups in comparison to lower concentrated growth factors. At 1 and 2 weeks, the use of growth factors in low concentrations (25 ng/ml VEGF and bFGF) significantly increased the amount of fibrovascular tissue, average fraction of blood vessels and number of blood vessels at the matrix,host interface in comparison to growth factor-free controls. Higher concentrations were neither associated with further increase of tissue formation nor with increased sprouting of blood vessels in this model. This study demonstrates that fibrin gel-immobilized angioinductive growth factors efficiently stimulate generation of fibrovascular tissue and sprouting of blood vessels in a newly developed subcutaneous upside-down isolation chamber model with an optimum between 25 and 100 ng/ml. [source] Tissue reaction of the rabbit urinary bladder to tension-free vaginal tape and porcine small intestinal submucosaBJU INTERNATIONAL, Issue 6 2002D.M. Rabah Objectives ,To compare the histological tissue reactions of urinary bladder in close contact with polypropylene mesh tension-free vaginal tape (TVT) or porcine small intestinal submucosal (SIS) grafts, as the commercial availability of various materials has considerably simplified sling procedures for treating urinary incontinence, but erosion and infection after using artificial sling materials remain an important concern. Materials and methods ,Thirty female New Zealand rabbits were randomized to three groups, i.e. group A (TVT, 12 animals), group B (SIS, 12) and group C (surgical control, six). Through a laparotomy under anaesthesia and an aseptic technique, the bladder was approached at its dome, where a 0.5 × 1 cm piece of TVT or SIS was fixed in direct contact with the bladder wall. The control group underwent only bladder manipulation with no material applied. Half the animals in each group were killed after 6 weeks and the other half after 12 weeks. The urinary bladder was harvested and examined histologically. Results ,The grafts in both groups were characterized by dense foreign-body type reactions and were mostly attached loosely to the bladder wall by a thin layer of fibrovascular tissue. More importantly, the bladder wall reactions showed no inflammation in all 12 animals in group A (TVT) but three of them had various grades of fibrosis. There was severe transmural inflammation in one animal in group B (SIS); one rabbit had grade I and two had grade II fibrosis. The controls, as expected, showed no bladder wall reactions. Conclusion ,In this descriptive analysis of reaction types elicited on the urinary bladder by these grafts, both materials appeared to be safe. Although TVT elicited fewer and less severe adverse reactions, no statistical conclusions can be drawn. The clinical significance of these findings should emerge from long-term clinical data when they become available. [source] Pterygium surgery long term follow-upACTA OPHTHALMOLOGICA, Issue 2009T WOOD Purpose To determine if a pterygium surgical procedure consisting of minimal conjunctival removal, excision of the hypertrophic subconjunctival fibrovascular tissue, application of mitomycin 0.25 mg/ml for 1 minute combined with temporary nasal tarsorrhaphy, and postoperative dexamethasone/antibiotic drops achieved the following: safely simplified pterygium removal, controlled the early side effects of mitomycin, reduced the rate of recurrence, and eliminated the need for conjunctival transplantation. Methods Twenty eyes of 19 patients underwent the procedure with mitomycin; fifteen were primary and 5, recurrent. These were compared to a previous group of 28 eyes in 26 patients that underwent pterygium/tarsorrhaphy surgery without mitomycin; twenty had primary and 8 had recurrent pterygia. Postoperatively, all eyes in both groups were treated with dexamethasone/antibiotic drops. Results In the mitomycin group (average follow-up 25 months), 19 of 20 eyes healed uneventfully. At 12 months, there had been no recurrences in the mitomycin group. In the non-mitomycin group (average follow-up 43 months), 9 (32%) recurred within 12 months; four (44%) of these required a second procedure at an average of 9 months. At 23 and 33 months, 2 (10%) eyes treated with mitomycin presented with asymptomatic, one mm recurrences that required no additional treatment. Conjunctival healing, as reflected in the time from surgery until tarsorrhaphy opening, was significantly longer in the mitomycin group, 37 vs. 17 days (P = .001). Conclusion The described technique provided a safe and successful approach to pterygium management. [source] | ||||||||||