Leukocyte-Poor Platelet-Rich Plasma-Derived Growth Factors Enhance Human Fibroblast Proliferation In Vitro.

BACKGROUND: Leukocyte-poor platelet-rich plasma (LP-PRP) from peripheral blood is currently used as a concentrated source of growth factors to stimulate repair at sites of soft tissue injury. Fibroblasts are primary mediators of wound healing. Thus, we aimed to assess the positive effect of LP-PRP on human fibroblast proliferation in vitro. METHODS: LP-PRP was prepared from 49 donors. The fibroblasts were seeded, and at 24 hours after seeding, 1 × 107/10 µL LP-PRP was added once to each well. The cells were harvested 10 times during study period at our planned points, and we examined cell proliferation using the water-soluble tetrazolium salt-1 assay. We collected the supernatants and measured the amount of growth factors such as platelet-derived growth factor (PDGF)-AB/BB, insulin-like growth factor-1 (IGF-1), transforming growth factor-ß1 (TGF-ß1), and vascular endothelial growth factor (VEGF), which are known to be involved in wound healing processes, by multiplex assay. RESULTS: Human fibroblasts treated with LP-PRP showed a significant increase in proliferation when compared to untreated controls (p < 0.001 at days 4, 6, and 8). Multiplex cytokine assays revealed various secretion patterns. PDGF-AB/BB appeared at early time points and peaked before fibroblast proliferation. IGF-1 and TGF-ß1 secretion gradually increased and peaked on days 4 and 6 post-treatment. The early VEGF concentration was lower than the concentration of other growth factors but increased along with cell proliferation. CONCLUSIONS: Platelets in LP-PRP release growth factors such as PDGF, IGF-1, TGF-ß1 and VEGF, and these growth factors have a promoting effect for human fibroblast proliferation, one of the important mediators of wound healing. These results suggest that growth factors derived from LP-PRP enhance the proliferation of human fibroblast.

Can a Single Sagittal Magnetic Resonance Imaging Slice Represent Whole Fatty Infiltration in Chronic Rotator Cuff Tears at the Supraspinatus?

BACKGROUND: This study aimed to investigate whether fatty infiltration (FI) measured on a single sagittal magnetic resonance imaging (MRI) slice can represent FI of the whole supraspinatus muscle. METHODS: This study retrospectively reviewed the MRIs of 106 patients (age 50-79 years) divided into three rotator cuff tear-size groups: medium, large, and massive. Fat mass and muscle mass on all T1-weighted sagittal MRI scans (FA and MA) were measured. Of the total MRI scans, the Y-view was defined as the most lateral image of the junction of the scapular spine with the scapular body on the oblique sagittal T1-weighted image. Fat mass and muscle mass seen on this Y-view single slice were recorded as F1 and M1, respectively. Fat mass and muscle mass were also assessed on MRI scans lateral and medial to the Y-view. The means of fat mass and muscle mass on these three slices were recorded as F3 and M3, respectively. Average FI ratios (fat mass/muscle mass) of the three assessment methods (F1/M1, FA/MA, and F3/M3) were compared. Intraclass correlation coefficients (ICCs) were calculated for inter- and intraobserver reliability. RESULTS: ICCs showed higher reliability (> 0.8) for all measurements. F1/M1 values were not statistically different from FA/MA and F3/M3 values (p > 0.05), except in males with medium and large tears. F3/M3 and FA/MA were not statistically different. The difference between F1/M1 and FA/MA did not exceed 2%. CONCLUSIONS: A single sagittal MRI slice can represent the whole FI in chronic rotator cuff tears, except in some patient groups. We recommend measurement of FI using a single sagittal MRI slice, given the effort required for repeated measurements.

Measurement of CT image of human cervical vertebral endplate and its significance / 吉林大学学报(医学版)

Objective To measure the morphological parameters of cervical endplate of Chinese by using computed tomography (CT)scans,and to provide an accurate morphometric basis for designing and developing the cervical disc prostheses.Methods 80 healthy subjects were scanned by CT.The parameters of each cervical vertebra from C3 to C7 were measured by CT scans including upper anteroposterior length (APLu),upper center mediolateral length (CMLu),lower anteroposterior length (APLl) and lower center mediolateral length (CMLl).These parameters were compared between genders and among different vertebral levels.Results The values of APLu, CMLu,APLl and CMLl were increased with the decreasing of cervical segment (P APLu = 0.023,P CMLu = 0.007, P APLl =0.035,P CMLl < 0.001).There was statistically significant difference in morphological parameters between genders (P < 0.05).Compared with the reported data of other different populations,the statistically significant difference in morphological parameters also existed in the study.Conclusion The study provides an accurate morphological basis for designing the suitable artificial cervical disc for Chinese population.