Polymeric biomaterials composed of extracellular matrix components possess osteoconductive capacity that is essential for bone healing. The presence of collagen and the ability to undergo physicochemical modifications render these materials a suitable alternative in bone regenerative therapies. The objective of this study was to evaluate the osteogenic capacity of collagen-based matrices (native and anionic after alkaline hydrolysis) made from bovine intestinal serosa (MBIS). Twenty-five animals underwent surgery to create a cranial defect to be filled with native and anionic collagen matrixes, mmineralized and non mineralized. The animals were killed painlessly 6 weeks after surgery and samples of the wound area were submitted to routine histology and morphometric analysis. In the surgical area there was new bone formation projecting from the margins to the center of the defect. More marked bone neoformation occurred in the anionic matrices groups in such a way that permitted union of the opposite margins of the bone defect. The newly formed bone matrix exhibited good optical density of type I collagen fibers. Immunoexpression of osteocalcin by osteocytes was observed in the newly formed bone. Morphometric analysis showed a greater bone volume in the groups receiving the anionic matrices compared to the native membranes. Mineralization of the biomaterial did not increase its osteoregenerative capacity. In conclusion, the anionic matrix exhibits osteoregenerative capacity and is suitable for bone reconstruction therapies.
Objective To analyze whether passive inhalation of cigarette smoke causes morphological, structural, and functional changes in kidneys of rats. Methods Wistar rats, aged eight weeks, weighing on average 260g, were divided into Control Group and Smoking Group. Each group was subdivided into four groups of ten animals for morphofunctional analysis, in a period of seven and 28 days. The Smoking Group was exposed to smoke of 40 cigarettes per day, at certain times and in automated equipment for cigarette burning, called smoking machine (SM-MC-01). After the exposure period, urine and blood samples were collected for the functional analyses, and the kidneys were dissected and submitted to histological procedures for morphoquantitative analyses. Results After exposure of animals of the Smoking Group, the following were observed: lower weight gain; lower water and feed intake; decreased renal weight, diameter, and volume; reduction in cortical thickness and glomerular volume density; decrease in glomerular and capsular diameter; increase in mesangial density; decreased urine volume; increased levels of glucose, serum creatinine and microalbuminuria; decreased urinary creatinine levels and creatinine clearance rate. Conclusion Passive smoking negatively influences renal morphology and glomerular filtration rate, with effects similar to those described in the literature regarding active smoking.
Objective: To determine whether passive smoking causes morphological and structural changes in the arcuate arteries of rats exposed for 7 to 28 days. Methods: Wistar rats aged eight weeks and weighing 260g on average were allocated to a Control or a Smoker Group. Groups were further divided into 4 groups containing 5 animals each. Morphological-functional analysis of the right kidneys was carried out after 7 and 28 days of exposure to the smoke of 40 cigarettes per day. Cigarettes were burned at set times using automated cigarette-burning equipment ("Smoking Machine" -SM-MC-01). At the end of each exposure period, the kidneys were dissected and submitted to histological processing for morphological and quantitative analysis. Results: Exposure to cigarette smoke for 7 days led to a decrease in inner vascular diameter. Decreased thickness of the vascular tunica media was observed after exposure for 28 days. Increased thickness of the tunica adventitia, increased total vascular wall thickness, increased total vascular diameter and qualitative increase in collagen deposition were observed. Vascular volume increased after 28 days of exposure. Conclusion: Passive smoking has a negative impact on renal vasculature.
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