Analysis the effect of different centrifugal conditions on the results of coagulation / 国际检验医学杂志

Objective To verify the effect of different centrifugal conditions on coagulation and ascertain the optimum centrifugal time for coagulation testing in the laboratory .Methods Navy General hospital check‐up and hospitalized patients were divided into three groups which were conventional group ,standard group and speed up the group respectively according the different centrifuga‐tion conditions .The platelet poor plasma (PPP) was harvested in the three different groups .The PT ,INR ,FIB and APT T were tested and the results were compared and analyzed .Samples with different platelets were centrifuged in normal condition or standard condition ,after that ,the residual platelet in plasma was detected .Results There was no significant difference of the PT ,INR ,FIB and APT T results among the routine group ,speed group and the standard group .The results of PPP was qualified 100% in samples which platelets were less than 500 × 109 /L with routine conditions and standards of centrifugal conditions .However ,the qualified result of PPP was dropped to 64% in those samples which platelets were higher than 500 × 109 /L with routine and standards of centrifugal conditions .Conclusion The conventional centrifugation conditions can meet clinical routine coagulation testing require‐ments ,the special types of coagulation assays or the samples which platelets count are more than 500 × 109 /L should centrifuge in accordance with the requirements of the CLSI centrifugal processing .

Expressão de metaloproteinases de matriz e PCNA em úlceras de córnea profundas, induzidas em coelhos, tratadas com plasma rico em plaquetas / Expression of matrix metalloproteinases and PCNA in deep corneal ulcers induced in rabbits, treated with platelet-rich plasma

O objetivo deste estudo foi avaliar a influência do plasma rico (PRP) e pobre (PPP) em plaquetas na proliferação celular e expressão de metaloproteinases de matriz (MMPs), durante a reparação de úlceras corneais profundas. Foram utilizadas 45 coelhas, distribuídas em 3 grupos (G) experimentais (n=15), designados como grupos PRP (GR), PPP (GP) e Controle (GC), de acordo com o tratamento. Todos os animais foram submetidos à indução cirúrgica unilateral de úlcera corneal. No GR e GP, o sangue autólogo foi centrifugado, utilizando-se protocolo padronizado, e foram confeccionados os colírios de PRP e PPP, e instilados cinco vezes ao dia. No GC, foi utilizado colírio lubrificante. Cada grupo foi subdividido (n=5), segundo o momento final de avaliação, sendo 4 (M4), 7 (M7) e 30 dias (M30). As córneas dos animais foram processadas para avaliação morfológica e imuno-histoquímica para PCNA, MMP1, MMP2, MMP9, MT1-MMP e TIMP1. No M4, os níveis de MMP2 foram maiores no GP e GR, sendo que, no M7, esse comportamento foi observado apenas no GP. No M30, no GR, verificou-se maior número de células epiteliais e marcação para MMP1 que o GP. No GR, a proliferação celular foi maior no M4 que nos demais momentos, e a marcação para MMP2 foi maior no M4 que no M30. O PRP estimula a proliferação celular na fase inicial (M4) do tratamento quando comparado aos demais momentos, diferentemente dos demais tratamentos. O uso de colírios de plasma rico e pobre em plaquetas influencia a expressão de metaloproteinases de matriz envolvidas no processo de reparação corneal.

The aim of this study was to evaluate the influence of platelet-rich (PRP) and poor (PPP) plasma in cell proliferation and matrix metalloproteinases (MMPs) expression during the repair of deep corneal ulcers. Forty-five female rabbits were distributed in 3 experimental groups (G) (n = 15), referred to as PRP (GR), PPP (GP) and Control (GC) groups, in accordance with the treatment. All animals underwent surgical induction of unilateral corneal ulcer. PRP and PPP eye drops were made by using centrifuged blood through standardized protocol, and instilled five times a day. In GC, lubricant eye drops were used. Each group was subdivided (n = 5) according to the final time point, 4 (M4), 7 (M7) and 30 days (M30). The animals' corneas were processed for morphological and immunohistochemical analysis for PCNA, MMP1, MMP2, MMP9, MT1-MMP and TIMP1. In M4, the levels of MMP2 were higher in GP and GR, and in M7, this behavior was only observed in the GP. In M30, more epithelial cells and MMP1 expression were found in GR than GP. In GR, cell proliferation was higher in M4 than at other time points and MMP2 expression was higher in M4 than M30. The PRP stimulates cell proliferation in the early phase (M4) of treatment when compared to other time points, different from other treatments. The use of eye drops of platelet-rich and poor plasma influences the expression of matrix metalloproteinases involved in the corneal repair process.

Effect of bovine bone (Bio-Oss(R)) and platelet rich plasma, platelet poor plasma on sinus bone graft in rabbit

Maxillary sinus lift and bone graft are used to reconstruct atrophic maxilla molar area for endosseous dental implants. Many different grafting materials and techniques can be used for maxillary sinus bone graft. Bio-Oss(R) has been proposed as bone substitute and successfully utilized as osteoconductive filler. Platelet rich plasma (PRP) is an autologous material with many growth factors, such as PDGF, TGF-beta, IGF, VEGF, facilitating bone healing process. And Platelet poor plasma (PPP) is the by-product in procedure of producing PRP. Six rabbits were used as experimental animal. Both maxillary sinus were grafted with Bio-Oss(R) and PRP, and Bio-Oss(R) and PPP. Rabbits were sacrificed at 4, 8 and 12 weeks. The grafting sites were evaluated by histomorphometric analysis. As a result, using PRP showed excellent bone formation in the early stage, but no further significant effect after that. In late stage, the ability of bone formation of using PRP was even worse than using PPP. The further studies need to be considered in this case.

Effects of Platelet Supernatants on the Proliferation of Fibroblast and the Wound Healing in the Rabbit

The academic, clinical and economic impacts of active approaches to wound care remain undetermined because wound healing occurs through a complex interaction of enzymatic cascades and a cellular module of interdependent components. Platelet-derived wound healing factors, which are released from the platelet alpa-granule, are currently recognized as the main element in wound healing process. This study is aimed at determining whether the human platelet supernatants including various growth factors would improve the wound healing process in vitro and in vivo studies. Platelet supernatants or platelet poor plasma was added to cultured skin fibroblasts and also applied on 8 mm diameter full thickness defects on rabbit ears(4.0-4.5 kg, New Zealand white rabbit). For the determination of cell growth, DNA and collagen synthesis were measured with [3H]-thymidine and [3H]-proline incorporation. For the determination of wound healing, three full thickness defects were made on each rabbit ear and the subjects were divided into 3 groups: control group treated with normal saline(n = 10), platelet supernatants treated group(n = 10), platelet poor plasma treaed group(n = 10). Histologic sections crossing the center of the wound were obtained on the 7th day after the operation. The diameter of wound gap was subsequently measured with a calibrated lens micrometer and the area of new graulation was measured with an image analyzing system. The results were as follows: 1. The platelet supernatants group revealed a significant increment in the DNA and collagen synthesis as compared to that of the platelet poor plasma group(p< 0.05). DNA synthesis and collagen synthesis of cultured fibroblasts in the platelet poor plasma group were significantly increased as compared to the control groups(p< 0.05). 2. The wound diameters were significantly decreased in the platelet supernatants group and new granulation tissues recovered the wound intensively in the platelet supernatants group as well, as compared to the control or platelet poor plasma group(p< 0.05). These results suggested that the platelet supernatants increases proliferation and collagen synthesis of fibroblasts and virtually promotes the wound healing process. As platelet supernatants is safe and cost effective and can be obtained by a simple method, it may be clinically useful as a source of growth factors.