Is the combination of fat grafts and platelet rich plasma effective in rats?

ABSTRACT PURPOSE: To investigate if the association of fat grafts and platelet-rich plasma (PRP) improves graft viability in female rats. METHODS: This is an experimental, randomized and blinded study, which involved 47 rats. Fat was harvested from the inguinal region and grafted to the cranial region. The experimental group consisted of PRP-enriched fat grafts (n=22) whilst the control group consisted of fat graft only (n=25). After a 100-day period, the animals were euthanised and the fat grafts were analyzed using scores from 0 (absent) to 4 (abundant), in optical microscopy by two independent and blinded pathologists. RESULTS: Regarding fat graft cell viability, the PRP group scored moderate/abundant in 63% of cases and the fat graft only group scored absent/slight in 72% of cases (p=0.03). The PRP group also presented lower fat necrosis scores when compared to the fat graft only group (p=0.03). Tumors (dermoid cysts) within the fat grafts were observed in three animals in which the grafts were mixed with PRP. CONCLUSION: Platelet-rich plasma improves the viability and integration of fat grafts in rats, but more studies are needed to fully understand the exact mechanisms that lead to this improvement and assess the safety of the method for use in humans.

Effects of Lipokit® centrifugation on morphology and resident cells of adipose tissue / Efectos de la centrifugación de Lipokit® sobre la morfología y las células residentes del tejido adiposo

The aim of adipose tissue engineering is creating autologus vascularized fat tissue to be used for practical soft tissue reconstruction in human clinic. Unfortunately, in practice, long-term results of fat transplantation are often untrustworthy and unreliable, to overcome this problem different many lipoinjection techniques developed in the last 20 years. Centrifuge is a fundamental stepin the preparation of adipose tissue. We focused on some cell markers especially MSCs markers and histological structural properties after with lipokit centrifugation and without lipokit centrifugation of adipose tissue obtained by liposuction by this new technique. Adipose tissue was taken by liposuction and separates to two portions. One of them is centrifugated by Lipokit machine (C+) has a micro filter and the other is not (C-). After centrifugation smear slides and paraffin sections were prepared from these tissues. These slides were stained with H&E and Toluidine Blue. Paraffin sections were immunohistochemically stained with CD34, von Willebrand Factor, CD73, CD90 and CD105. Smear preparations showed a continuous three dimensional plasma membrane appearance of adipocytes. C+ and C- showed expression of CD34, von Willebrand Factor, CD73, CD90, CD105. C+ seems to have more free cells expressing than C-. While passing the filter of Lipokit, large adipocytes and connective tissue parts disintegrate and thus increases the surface area of lipoaspirate. Lipokit® machine release the group cells which are necessary for angiogenesis and they become more freely to construct angiogenesis.

El objetivo de la ingeniería del tejido adiposo es la creación de tejido graso vascularizado autólogo para ser utilizado en clínica humana para la reconstrucción de tejido blando. Desafortunadamente en la práctica, los resultados a largo plazo del trasplante de grasa son poco fiables y no seguros; para superar este problema, se han desarrollado en diferentes países, en los últimos 20 años, variadas técnicas de lipoinyección. La centrifugación es un paso fundamental en la preparación del tejido adiposo. Nos hemos centrado en algunos marcadores, especialmente, de células precursoras mesenquimales y propiedades histológicas estructurales después de la centrifugación mediante Lipokit y sin la centrifugación por Lipokit del tejido adiposo obtenido mediante liposucción. El tejido adiposo fue tomado por liposucción y se separó en dos porciones. Una se centrifugó mediante el sistema Lipokit (C +), con un microfiltro y la otro no (C-). Después de centrifugación, muestras del frotis y secciones de parafina se prepararon a partir de estos tejidos. Los frotis se tiñeron con H&E y azul de toluidina. Las secciones de parafina se tiñeron inmunohistoquímicamente con CD34, factor de von Willebrand, CD73, CD90 y CD105. Las preparaciones de los frotis mostraron una apariencia tridimensional continua de la membrana plasmática de los adipocitos. Tanto en C+ y C- se observó la expresión de CD34, factor de von Willebrand, CD73, CD90 y CD105. En C+ parecen expresarse más células libres que en C-. Cuando se utilizó el filtro de Lipokit, los adipocitos grandes y partes del tejido conectivo se desintegraron, por lo tanto aumentó el área de superficie de lipoaspirado. El sistema Lipokit® libera los grupos celulares que son necesarios para la angiogénesis y se hacen más libres para promoverla.

Prognostic significance of skin and subcutaneous fat sequestration of parasites in severe falciparum malaria.

Intradermal blood smear, histopathologic and immunohistologic studies were performed in severe malaria (n=10) and uncomplicated malaria (n=10) patients during positive parasitemia and within 6 hours after negative parasitemia by finger prick smears. Intradermal blood smears showed asexual forms and intraleukocytic pigments when finger prick blood smears showed negative results; however intradermal blood smear did not indicate disease severity within 6 hours after negative parasitemia by finger prick. Histopathologic findings showed 15 fold higher parasitized red blood cells sequestered in vessels of subcutaneous fatty tissue in severe malaria than in uncomplicated malaria (p<0.001) and may indicate disease severity. A panel of polyclonal antibodies against cytokines applied to skin biopsies clearly detected a higher titer against tumor necrosis factor-alpha (TNFalpha) and interleukin-10 (IL-10) in dermal vessels and stratum granulosum respectively, in severe malaria compared with uncomplicated malaria. Results of the study suggest that histopathology and immunohistology of skin and subcutaneous fatty tissue may indicate prognostic severity of malaria and may be associated with focal accumulation of cytokines.