A new methodology was developed to measure spatial variations in chondrocyte/matrix structural parameters and chondrocyte biosynthetic activity in articular cartilage. This technique is based on the use of a laser scanning confocal microscope that can "optically" section chemically fixed, unembedded tissue. The confocal images are used for morphometric measurement of stereologic parameters such as cell density (cells/mm3), cell volume fraction (%), surface density (l/cm), mean cell volume (micron3), and mean cell surface area (micron2). Adjacent pieces of tissue are simultaneously processed for conventional liquid emulsion autoradiography, and a semiautomated grain counting program is used to measure the silver grain density at regions corresponding to the same sites used for structural measurements. An estimate of chondrocyte biosynthetic activity in terms of grains per cell is obtained by dividing the value for grain density by that for cell density. In this paper, the newly developed methodology was applied to characterize the zone-specific behavior of adult articular cartilage in the free-swelling state. Cylinders of young adult bovine articular cartilage were labelled with either [3H]proline or [35S]sulfate, and chondrocyte biosynthesis and structural parameters were measured from the articular surface to the tidemark. The results showed that chondrocytes of the radial zone occupied twice the volume and surface area of the chondrocytes of the superficial zone but were 10 times more synthetically active. This efficient and unbiased technique may prove useful in studying the correlation between mechanically induced changes in cell form and biosynthetic activity within inhomogeneous tissue as well as metabolic changes in cartilage due to ageing and disease.
In this study, we investigated the depth-dependent metabolic and structural responses of adult articular cartilage to large-strain, static, unconfined compression. Changes in cell biosynthetic activity and several morphometry-based structural parameters (cell density, cell volume fraction, cell surface-area density, mean cell surface area, and mean cell volume) were measured at eight sites representing different depth-zones between the articular surface and the cartilage/bone border. In addition, local axial strain in the superficial, transitional, upper radial, and lower radial zones was estimated on the basis of the change in cell density values. Static compression of articular cartilage revealed a highly heterogeneous deformation profile through the depth of the sample as well as zone-specific changes in biosynthetic activity, as reflected by incorporation of [3H]proline. The axial strains in the top layers were greater than the applied surface-to-surface strain, whereas axial strains adjacent to the cartilage/bone border were significantly less than the applied strain. Zonal changes in cell density and axial strain that occurred during static compression correlated well with alterations in metabolic activity. These coordinated changes between cell biosynthesis and cartilage structure suggest that zone-specific variations in mechanical stimuli could be responsible for spatially varied patterns of cartilage metabolic activity under load.
A restrictive-deferred hydration combined with preemptive norepinephrine infusion during radical cystectomy and urinary diversion significantly reduced the postoperative complication rate and hospitalization time.
General anesthesia with epidural analgesia was associated with a reduced risk of clinical cancer progression. However, no significant difference was found between general anesthesia plus postoperative ketorolac-morphine analgesia and general anesthesia plus intraoperative and postoperative thoracic epidural analgesia in biochemical recurrence-free survival, cancer-specific survival, or overall survival.
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