Objective To explore the relevance of serum homocysteine (Hcy) level to erythrocyte and platelet parameters in patients with unstable angina pectoris (UAP). Methods Sixty patients with UAP were collected in Tongling Municipal Hospital from August 1st, 2012 to December 31st, 2015. Serum Hcy was measured by enzymatic cycling method. Erythrocyte parameters, such as red blood cell count (RBC), hemoglobin, mean corpuscular volume (MCV), coefficient of variation of red blood cell volume distribution width (RDW-CV), and platelet parameters, such as platelet count (PLT), platelet distribution width (PDW), mean platelet volume (MPV), platelet large cell ratio (P-LCR), were measured with blood cell counter. All patients were classified into UAP with hyperhomocystinemia (HHcy) group and UAP with normal Hcy group according to the level of Hcy. The data in two groups were analyzed and the relevance of serum Hcy level to erythrocyte and platelet parameters was evaluated. Results The differences in the levels of RBC, hemoglobin, MCV, PLT, PDW, MPV, P-LCR between the two groups were not statistically significant (P>0.05); while the levels of RDW-CV and the proportion of RDW-CV above the upper reference limit of patients in the UAP with HHcy group (13.81%±1.13%, 39.4%) were higher than those in the UAP with normal Hcy group (13.06%±0.97%, 4.8%), and the differences between the two groups were statistically significant (P<0.05). Correlation analysis showed that serum Hcy level of patients with UAP was significantly correlated with RDW-CV (r=0.380, P<0.01) and was not significantly correlated with other erythrocyte and platelet parameters (P>0.05). Conclusion The high level of Hcy affects red blood cell volume heterogeneity in patients with UAP, which may be one of the mechanisms of HHcy participating in the occurrence and development of UAP.
【Abstract】 Objective To find out the best method to prepare platelet-rich plasma (PRP) and to evaluate the effect of PRP gel on skin flap survival and its mechanism. Methods Totally, 72 Wistar rats (aged 12 weeks, weighing 250-300 g) were used for the experiment. The arterial blood (8-10 mL) were collected from the hearts of 24 rats to prepare PRP with three kinds of centrifuge methods: in group A, 200 × g centrifuge for 15 minutes, and 500 × g centrifuge for 10 minutes；in group B, 312 × g centrifuge for 10 minutes, and 1 248 × g centrifuge for 10 minutes；and in group C, 200 × g centrifuge for 15 minutes, and 200 × g centrifuge for 10 minutes. The platelet was counted in the whole blood, PRP, and platelet-poor plasma (PPP) to determine an ideal centrifuge. PRP, PPP, and the serum after first centrifuge were collected. The concentrations of platelet-derived growth factor BB (PDGF-BB) and transforming growth factor β1 (TGF-β1) were measured in the PRP, PPP, and serum using the enzyme-linked immunosorbent assay method, and PRP and PPP gels were prepared. The flaps of 11 cm × 3 cm in size were elevated on the back of 48 rats, which were divided into 3 groups: PRP gel (PRP group, n=16) and PPP gel (PPP group, n=16) were injected, no treatment was given in the control group (n=16). The flap survival rate was measured at 7 days. Histological and real-time PCR were used to count the inflammatory cells and blood vessel density, and to detect the expressions of vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), PDGF-AA, and PDGF-BB mRNA at 8 hours, 24 hours, 3 days, and 7 days. Results Platelet counting showed platelet in group A was the highest. ELISA evaluation showed that the concentrations of TGF-β1 and PDGF-BB were significantly higher in PRP than in PPP and serum (P lt; 0.05). The flap survival rate was 61.2% ± 9.1% in PRP group, showing significant differences (P lt; 0.05) when compared with that in PPP group (35.8% ± 11.3%) and control group (28.0% ± 5.4%). The inflammatory cells were significantly lower and the blood vessel density was significantly higher in PRP group than in PPP group and control group (P lt; 0.05). When compared with PPP group and control group, the expressions of VEGF and PDGF-BB increased at all time after operation in PRP group; the expression of EGF increased within 24 hours; and the expression of PDGF-AA increased after 3 days. There were significant differences in PDGF-AA mRNA at 3 days and 7 days, PDGF-BB mRNA at 8 hours, VEGF mRNA at 24 hours and 3 days, and EGF mRNA at 24 hours between PRP group and PPP and control groups (P lt; 0.05). Conclusion 200 × g centrifuge for 15 minutes and 500 × g centrifuge for 10 minutes is the best PRP preparation method. PRP can improve the skin flap survival by regulating the genes involved in angiogenesis.
OBJECTIVE: To investigate the expression and distribution of platelet derived growth factor receptor-beta(PDGFR-beta) in normal skin and keloid and to discuss its biological function in keloid formation. METHODS: 1. To detect the expression and distribution of PDGFR-beta in normal skin and keloid tissue by immunohistochemistry; 2. To detect the receptor expression in vitro by Flow cytometry (FCM); 3. To detect the subcellular distribution of receptor by Laser confocal microscope. RESULTS: 1. Immunohistochemistry showed that normal skin and keloid tissue were almost the same in expression but different in distribution of PDGFR-beta; 2. There was more expression of PDGFR-beta in normal fibroblasts than that in keloid fibroblasts in vitro by FCM; 3. Laser confocal microscope revealed that the PDGFR-beta concentrated on the surface of cell membrane in keloid fibroblasts, but in normal skin fibroblasts, the receptors were coagulated on the nuclear membrane and intranucleus. CONCLUSION: Compared with the fibroblasts in vivo, there was a difference of the PDGFR-beta expression in fibroblasts in vitro, more expression of PDGFR-beta in normal fibroblast than that in keloid fibroblast in vitro; and the subcellular distribution of PDGFR-beta was different in normal skin and keloid fibroblasts. The characteristics of the expression and distribution of PDGFR-beta in keloid may contribute to the formation of keloid.
Objective To investigate the ability of plateletrich plasma(PRP) combined with cells and artificial bone in accelerating the repair of bone defect. Methods The marrow stromal stem cells (MSCs) of rabbit were cultured and induced into the osteoblast-like cells in vitro. PRP was produced with low-density twice centrifugations. Forty-eight New Zealand rabbits were made 1.2 cm bilateral radius defect models and divided into 4 groups averagely at random: group A(left:PRP／MSCs／β-tricalcium phosphate(β-TCP), right: MSCs／β-TCP), group B (left:autoradius, right: PRP／MSCs／β-TCP)； group C (left:autoradius,right: MSCs／β-TCP), and group D(left:PRP／β-TCP; right:β-TCP). At 2, 6 and 12 weeks after operation， the repair of bone defect was evaluated by the generalobservation, histology, biomechanics and histomorphology. Results There was a stable platelet concentration in PRP and it was about 5.45±0.23 times of whole blood. In the aspect of bone bridge and conture of the defects, at 2 and 6 weeks, PRP／MSCs／β-TCP and MSCs／β-TCP displayed asimilar outcome and were less than auto in general sample and X-ray;at12 weeks，PRP／MSCs／β-TCP was similar to autoradius and better than MSCs／β-TCP.in the aspect of quantity and quality of bone formation，histology showed that PRP／MSCs／β-TCP and autoradius were better than MSCs／β-TCP（P＜0.05），and there was nosignificantdifference between PRP／MSCs／β-TCP and autoradius（P＞0.05）. At 2 and 6 weeks，there was no significant difference between PRP／β-TCP and β-TCP（P＞0.05）。At 12 weeks，PRP／β-TCP was better than β-TCP（P＜0.05）. In the aspect of intensity f bone formation，at 6 and 12 weeks，PRP／MSCs／β-TCP and autoradiuswere better than MSCs／β-TCP（P＜0.05）. At 6 weeks，autoradius was better than PRP／MSCs／β-TCP（P＜0.05）. At 12 weeks，there was no significant difference between PRP／MSCs／β-TCP and auto（P＞0.05）. PRP／TCP and β-TCP had no significant difference at 12 weeks（P＞0.05）. Conclusion PRP／MSCs／β-TCP demonstrated excellent ability of forming bone in experiment. PRP was most likely to accelerate the repair of bone defect through increasing the activity of proliferation and differentiationof MSCs and osteoblasts.
Objective To investigate the effects of platelet-derived growth factor(PDGF) on the expression of α-smooth muscle actin(α-SMA) of cultured human retinal pigment epithelium cells(RPE). Methods Cultured human RPE cells of the 4-6 th passages were divided into two groups: Delbecco′s modified Eagle′s medium (DMEM) and 2%DMEM (20 g/L foeta calf serum+DMEM). PDGF (0,1,50 ng/ml) was added to medium.The expression of α-SMA was detected and quantitatively analyzed by image process of immunofluorescence.Results PDGF stimulated the expression of α-SMA of human RPE cells.In group of DMEM, The rate of RPE of α-SMA expression was 40%-50% and the intension of fluorescence was 8.08 without PDGF. After stimulated by PDGF(1 ng/ml,50 ng/ml), the rates were 80% and 90% respectively, and the intension of fluorescence were 12.35 and 17.23. In 2%DMEM group, The rates of RPE of α-SMA expression were 85% without PDGF, and 95% ,100% respectively treated with PDGF (1 ng/ml,50 ng/ml). The intension of fluorescence was 14.79 without PDGF, and after stimulated by PDGF, they were 16.28 at 1 ng/ml and 21.36 at 50 ng/ml，which was 2 .7 times ber than that in DMEM group without PDGF. Conclusion PDGF could stimulate RPE cells to express α-SMA. (Chin J Ocul Fundus Dis，2003，19：201-268)
Objective To study the mechanism of compound of calcium phosphate(TCP) and platelet-rich plasma(PRP) in the treatment of femoral head necrosis.Methods The left femoral heads of 48 New Zealand white rabbits were frozen by liquid nitrogen as to make themodel of femoral head necrosis.Twenty-four rabbits were randomly chosen as theexperimental group and their femoral heads were filled with TCP/PRP. The other 24 rabbits were used as the control group and their femoral heads were filled only with TCP. They were sacrificed at 2, 4,8,12 weeks after operation. The specimens were examined with X-ray and histological study.Results At 2 weeks after operation,there was no significant difference in femoral headdensity between the two groups. Four weeks after operation, femoral head density decreased in both groups, while it decreased more in the control group. At 8,12 weeks after operation, the density of the femoral heads in both groups increased, and it was higher in the experimental group. Histology examination showed thatthere was no difference between the two groups 2 weeks after operation. The head became flat at 4 weeks. Control group had more defects. At 4,8,12 weeks, more repairs were observed in the experimental group than that in the control group. The amount and maturity of osteogenesis in experimental group were much more greaterthan those in control group．Bone histomorphometry showed that the volum of thetrabecular was larger in the experimental group (36.65%±7.22%,38.29%±4.28%，39.24%±3.42%) than that of control group(P＜0.05). Conclusion TCP/PRP does not only provide osteoblasts scaffold, butalso promotes bone formation and the head repair. TCP/PRP is a good biomaterialfor the treatment of femur head necrosis.
Objective To investigate the factors that affect platelet-rich plasma (PRP) in promoting bone regeneration and repairing. Methods Recent l iterature was reviewed, concerning the preparations of PRP, physiological mechanism and the latest appl ications in orthopedic field. Results PRP, the concentrated body of autologous platelet, was rich in platelets and was the source of autologous growth factors. Many studies had shown that PRP played an important role in promoting bone regeneration and repairing. However, a few experimental results contradicted this point. The reason might be that the biological properties of PRP were influenced by various factors, such as workmanship, vector, activation schemes, working concentration, individual difference. Conclusion The concentration and qual ity of platelet and other related factorsof PRP affect the rel iabil ity of the results and conclusions. So an efficient and stable production method of PRP should beestabl ished.
Objective To study the effect of mechanical stretch on the microenvironment of BEAS-2B on macrophage polarization and the role of polarized macrophages in the epithelial-mesenchymal transition (EMT) of BEAS-2B. Methods Using enzyme linked immunosorbent assay to detect the changes in the levels of cytokines such as interferon-γ, granulocyte-macrophage colony stimulating factor, tumor necrosis factor-α, interleukin (IL)-4, IL-6, IL-10 in the supernatant of lung epithelial cells cultured statically and mechanically stretched. The M0 macrophages (derived from THP-1) were stimulated by stretch/static conditioned medium of BEAS-2B. The surface markers of M1 (CD197) /M2 (CD206) macrophages were detected by flow cytometer. Stretch/static conditioned medium were used to stimulate the co-culture system of macrophages and BEAS-2B in the presence or absence of platelet-derived growth factor receptor inhibitor (PDGFRi), then the protein expression level of EMT makers was examined by Western blot. Results Exposure of BEAS-2B to mechanical stretch resulted in significantly higher production of the pro-M1/M2 polarized factor. The EMT of the co-culture system of M0 and BEAS-2B could be induced by stretch conditioned medium, epithelial marker cytokeratin (CK)-8 and E-cadherin were decreased, while mesenchymal marker α-smooth muscle actin, N-cadherin and vimentin were increased in stretch conditioned medium group. The expression of platelet-derived growth factor (PDGF) was significantly higher in stretch conditioned medium group. The PDGFRi can block the EMT in stretch conditioned medium group. Conclusions The lung epithelial cell supernatant induced by mechanical stretch can promote the polarization of macrophages to M1 and M2. Polarized macrophages promote EMT in human lung epithelial cells via PDGF, and blocking PDGF might attenuate the VILI-associated lung fibrosis.
Objective To investigate the effects of combined platelet-rich plasma (PRP) and arterial supercharging technique on the survival rate and functional restoration of cross-body region skin flaps in rabbits. MethodsTwelve healthy 6-month-old New Zealand White rabbits were randomly assigned to 4 groups (n=3): sham group, PRP group, anastomosis group, and combined treatment group. An axial skin flap with an area of 12 cm×6 cm on the inner side of the hind limbs of all animals were prepared, with the saphenous artery as the main blood supply. Following the ligation of both the proximal and distal ends of the saphenous artery across all groups, the sham group received no further intervention, the PRP group was subjected to PRP injection, the anastomosis group underwent in situ end-to-end anastomosis of the distal saphenous artery, and the combined treatment group received both in situ distal saphenous artery anastomosis and PRP administration. Flap survival was evaluated and recorded on postoperative days 1, 3, and 7, with survival rates calculated accordingly. On day 7, flap tissue samples were harvested for HE staining to assess basal tissue morphology. Additionally, immunohistochemical staining was conducted to detect the expression of α-smooth muscle actin (α-SMA), vascular endothelial growth factor (VEGF), and CD31 in the flap tissues. Results At postoperative day 1, no significant difference in flap survival rates were observed among the 4 groups (P>0.05). At day 3, the PRP group showed no significant difference compared to the sham group (P>0.05); however, both the anastomosis and combined treatment groups exhibited significantly higher survival rates than the sham group (P<0.05), the combined treatment group further demonstrated superior survival rates compared to both the PRP and anastomosis groups (P<0.05). At day 7, the combined treatment group maintained significantly higher survival rates than all other groups (P<0.05), while both the PRP and anastomosis groups exceeded the sham group (P<0.05). HE staining at day 7 revealed persistent inflammatory cell infiltration, sheet-like erythrocyte deposition, and disordered collagen fibers in the sham group. The PRP group showed nascent microvessel formation and early collagen reorganization, whereas the anastomosis group displayed mature microvasculature with resolved interstitial edema. The combined treatment group exhibited differentiated microvessels with densely packed collagen bundles. Immunohistochemical analysis at day 7 demonstrated significantly larger relative area percentages of α-SMA, VEGF, and CD31 positive cells in the combined treatment group compared to all other groups (P<0.05). Both the PRP and anastomosis groups also showed significantly higher values than the sham group (P<0.05). Conclusion The combination of PRP and arterial supercharging techniques significantly enhances flap healing, potentially through mechanisms involving augmented angiogenesis and improved blood supply.
ObjectiveTo review the research progress of the preparation and components of the platelet rich plasma (PRP). MethodsThe recent literature concerning the biological mechanism, preparation, and components of PRP was analyzed and summarized. ResultsThe biological function of PRP depends on a series of intricate cascade of cellular and molecular events. PRP contains different concentrations of platelets, which would release a large number of the activated molecules, and also contains a small amount of white blood cells and red blood cells. The preparation of PRP is based on platelet concentration. Different preparation techniques would lead to different platelet concentrations, recovery ratios, and components. ConclusionThere is no uniform standard for the preparation of PRP. Different preparation methods and technical parameters of PRP will get different components and different concentrations of PRP, which also provide a reference for cl inicians to select the most appropriate PRP for individual patient.