Anti-platelet activity of infusion of Tithonia diversifolia's leaves

Tithonia diversifolia, also known as Mexican arnica, has been used in traditional medicine to treat inflammatory refractory with absence of citotoxicity. The possible health risks associated with the consumption of ingestion of the infusion (tea) plant makes it is necessary to identify the potential pharmacological activity or toxicity to prove certain plants that are acclimated in Brazil. Considering the limited number of pharmacological studies regarding the Tithonia diversifolia, the aim of this study was evaluate the effects of this infusion in platelet aggregation. Venous blood was collected with informed consent from healthy volunteers who denied taking any medication in the previous 14 days. Whole blood was transferred into polypropylene tubes containing one-tenth of final volume of acid citrate dextrose (ACD-C; citric acid 3%, trisodium citrate 4%, glucose 2%; 1:9 v/v) and centrifuged at 200g for 15 min. Platelet rich plasma was added of wash buffer solution (NaCl 140mM, KCl 5mM, sodium citrate 12mM, glucose 10mM and saccharose 12mM; pH 6; 5:7 v/v) and centrifuged at 800g for 12 min at 20°C. Platelet pellet was gently resuspended in Krebs-Ringer solution and counts were performed on a Neubauer chamber. Aggregation assay was carried out with 400 μL of platelet suspension (1.2x10 8 platelets/mL) in a cuvette at 37°C with constant stirring. Platelet suspension was incubated for 3 min with aqueous extract infusion (0.6-20μg/mL) prior to addition of thrombin (100 mU/mL). Percentage of platelet aggregation was recorded with an aggregometer (Chrono-log Lumi-Aggregometer model 560-Ca, USA). Our results show an inhibition of thrombin induced platelet aggregation in the presence of 0.6-20 ug/mL Tithonia diversifolia infusion leaves. The Tithonia diversifolia infusion leaves inhibits thrombin induced washed platelet aggregation.

Glicerina bruta na dieta de bovinos de corte confinados: Efeito sobre o hemograma

The aim of this study was to evaluate the hemogram in cattle fed crude glycerin. 30 Nellore steers, were used for blood sampling, which were done each 28 days. The animals were confined for 103 days and were fed with five diets containing 0, 7.5, 15, 22.5 and 30% crude glycerin based on dry matter, formulated in a forage:concentrate ratio of 30:70. Corn silage was used as forage and the concentrate was composed by corn grain, soybean hulls, sunflower meal, glycerin, limestone, dicalcium phosphate and salt. The experimental design was a randomized block with five treatments. Orthogonal contrasts were used to determine the linear, quadratic, cubic effects and gliceryn treatments × the control one. There was no treatment effect (P>0,05) on blood concentrations of erythrocytes, hematocrit, basophils, eosinophils, band neutrophils and lymphocytes, but were linearly effect on the concentrations of platelets, hemoglobin and monocytes (P=0.009, P=0.001 and P=0.043, respectivelly), and cubic effect on the concentrations of total leukocytes and segmented neutrophils (P=0.008 and P=0.004, respectivelly). Diets for beef cattle, with forage:concentrate ratio of 30:70 added with crude glycerin promote changes in the erytrhogram and leucogram of these animals.

A simple procedure for the preparation of laponite and thermoplastic starch nanocomposites: Structural, mechanical, and thermal characterizations

The aim of this article is to propose advances for the preparation of hybrid nanocomposites prepared by the combination of intercalation from solution and melt-processing methods. This research investigates the effect of the laponite RDS content on the thermal, structural, and mechanical properties of thermoplastic starch (TPS). X-ray diffraction was performed to investigate the dispersion of the laponite RDS layers into the TPS matrix. The results show good nanodispersion, intercalation, and exfoliation of the clay platelets, indicating that these composites are true nanocomposites. The presence of laponite RDS also improves the thermal stability and mechanical properties of the TPSmatrix due to its reinforcement effect which was optimized by the high degree of exfoliation of the clay. Thus, these results indicate that the exfoliated TPS-laponite nanocomposites have great potential for industrial applications and, more specifically, in the packaging field. © The Author(s) 2011 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Is peripheral blood cell balanced altered by the use of fresh frozen bone block allografts in lateral maxillary ridge augmentation?

Background: The relationship between the immune response and red and white blood cell homeostasis is cited in literature, but no studies regarding the balance of these cell populations following maxillary bone-graft surgeries can be found. Aim: The aim of this study was to evaluate the possible impairments in the blood cell balance following fresh-frozen allogeneic bone-graft augmentation procedures in patients who needed maxillary reconstruction prior to implants. Material and Methods: From 33 patients elected to onlay bone grafting procedures, 20 were treated with fresh-frozen bone allografts and 13 with autologous bone grafts. Five blood samples were collected from each patient in a 6-month period (baseline: 14, 30, 90, and 180 days postsurgery), and the hematological parameters (erythrogram, leukogram, and platelets count) were accessed. Results: All evaluated parameters were within the reference values accepted as normal, and significant differences were found for the eosinophils count when comparing the treatments (30 days, p=.035) and when comparing different periods of evaluation (allograft-treated group, baseline×180 days, p≤.05 and 90×180 days, p≤.01; autograft-treated group, 30×90 days, p≤.05 and 30×180 days, p≤.05). Conclusions: Both autologous and fresh-frozen allogeneic bone grafts did not cause any impairment in the red and white blood cell balance, based on quantitative hemogram analysis, in patients subjected to maxillary reconstruction. © 2011 Wiley Periodicals, Inc.

Haematological response of curimbas Prochilodus lineatus, naturally infected with Neoechinorhynchus curemai

This study evaluated the haematological response of curimbas Prochilodus lineatus, naturally infected with Neoechinorhynchus curemai (Acanthocephala: Neoechinorhynchidae). Thirty-seven fish were captured in October 2010 from the Mogi Guaçu River, Porto Ferreira, SP, Brazil. Infected fish presented increased mean corpuscular volume of erythrocytes, and lower thrombocyte and higher monocyte counts than uninfected fish. © 2013 The Authors. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.

Platelet lysate 3D scaffold supports mesenchymal stem cell chondrogenesis: An improved approach in cartilage tissue engineering

Articular lesions are still a major challenge in orthopedics because of cartilage's poor healing properties. A major improvement in therapeutics was the development of autologous chondrocytes implantation (ACI), a biotechnology-derived technique that delivers healthy autologous chondrocytes after in vitro expansion. To obtain cartilage-like tissue, 3D scaffolds are essential to maintain chondrocyte differentiated status. Currently, bioactive 3D scaffolds are promising as they can deliver growth factors, cytokines, and hormones to the cells, giving them a boost to attach, proliferate, induce protein synthesis, and differentiate. Using mesenchymal stem cells (MSCs) differentiated into chondrocytes, one can avoid cartilage harvesting. Thus, we investigated the potential use of a platelet-lysate-based 3D bioactive scaffold to support chondrogenic differentiation and maintenance of MSCs. The MSCs from adult rabbit bone marrow (n=5) were cultivated and characterized using three antibodies by flow cytometry. MSCs (1×105) were than encapsulated inside 60μl of a rabbit platelet-lysate clot scaffold and maintained in Dulbecco's Modified Eagle Medium Nutrient Mixture F-12 supplemented with chondrogenic inductors. After 21 days, the MSCs-seeded scaffolds were processed for histological analysis and stained with toluidine blue. This scaffold was able to maintain round-shaped cells, typical chondrocyte metachromatic extracellular matrix deposition, and isogenous group formation. Cells accumulated inside lacunae and cytoplasm lipid droplets were other observed typical chondrocyte features. In conclusion, the usage of a platelet-lysate bioactive scaffold, associated with a suitable chondrogenic culture medium, supports MSCs chondrogenesis. As such, it offers an alternative tool for cartilage engineering research and ACI. © 2013 Informa UK Ltd.

Tissue-engineered blood vessel substitute by reconstruction of endothelium using mesenchymal stem cells induced by platelet growth factors

Background: Cardiovascular diseases remain leaders as the major causes of mortality in Western society. Restoration of the circulation through construction of bypass surgical treatment is regarded as the gold standard treatment of peripheral vascular diseases, and grafts are necessary for this purpose. The great saphenous vein is often not available and synthetic grafts have their limitations. Therefore, new techniques to produce alternative grafts have been developed and, in this sense, tissue engineering is a promising alternative to provide biocompatible grafts. This study objective was to reconstruct the endothelium layer of decellularized vein scaffolds, using mesenchymal stem cells (MSCs) and growth factors obtained from platelets. Methods: Fifteen nonpregnant female adult rabbits were used for all experiments. Adipose tissue and vena cava were obtained and subjected to MSCs isolation and tissue decellularization, respectively. MSCs were subjected to differentiation using endothelial inductor growth factor (EIGF) obtained from human platelet lysates. Immunofluorescence, histological and immunohistochemical analyses were employed for the final characterization of the obtained blood vessel substitute. Results: The scaffolds were successfully decellularized with sodium dodecyl sulfate. MSCs actively adhered at the scaffolds, and through stimulation with EIGF were differentiated into functional endothelial cells, secreting significantly higher quantities of von Willebrand factor (0.85 μg/mL; P < .05) than cells cultivated under the same conditions, without EIGF (0.085 μg/mL). Cells with evident morphologic characteristics of endothelium were seen at the lumen of the scaffolds. These cells also stained positive for fascin protein, which is highly expressed by differentiated endothelial cells. Conclusions: Taken together, the use of decellularized bioscaffold and subcutaneous MSCs seems to be a potential approach to obtain bioengineered blood vessels, in the presence of EIGF supplementation. © 2013 Society for Vascular Surgery.

Nanocomposite PAAm/methyl cellulose/montmorillonite hydrogel: Evidence of synergistic effects for the slow release of fertilizers

In this work, we synthesized a novel series of hydrogels composed of polyacrylamide (PAAm), methylcellulose (MC), and calcic montmorillonite (MMt) appropriate for the controlled release of fertilizers, where the components presented a synergistic effect, giving very high fertilizer loading in their structure. The synthesized hydrogel was characterized in relation to morphological, hydrophilic, spectroscopic, structural, thermal, and kinetic properties. After those characterizations, the application potential was verified through sorption and desorption studies of a nitrogenated fertilizer, urea (CO(NH2)2). The swelling degree results showed that the clay loading considerably reduces the water absorption capability; however, the hydrolysis process favored the urea adsorption in the hydrogel nanocomposites, increasing the load content according to the increase of the clay mass. The FTIR spectra indicated that there was incorporation of the clay with the polymeric matrix of the hydrogel and that incorporation increased the water absorption speed (indicated by the kinetic constant k). By an X-ray diffraction technique, good nanodispersion (intercalation) and exfoliation of the clay platelets in the hydrogel matrix were observed. Furthermore, the presence of the montmorillonite in the hydrogel caused the system to liberate the nutrient in a more controlled manner than that with the neat hydrogel in different pH ranges. In conclusion, excellent results were obtained for the controlled desorption of urea, highlighting the hydrolyzed hydrogels containing 50% calcic montmorillonite. This system presented the best desorption results, releasing larger amounts of nutrient and almost 200 times slower than pure urea, i.e., without hydrogel. The total values of nutrients present in the system show that this material is potentially viable for application in agriculture as a nutrient carrier vehicle. © 2013 American Chemical Society.

Platelet-Rich Plasma And Chronic Wounds: Remaining Fibronectin May Influence Matrix Remodeling And Regeneration Success

Background: Platelet-rich plasma has been largely used as a therapeutic option for the treatment of chronic wounds of different etiologies. The enhanced regeneration observed after the use of platelet-rich plasma has been systematically attributed to the growth factors that are present inside platelets' granules. Aim: We hypothesize that the remaining plasma and platelet-bound fibronectin may act as a further bioactive protein in platelet-rich plasma preparations. Methods: Recent reports were analyzed and presented as direct evidences of this hypotheses. Results: Fibronectin may directly influence the extracellular matrix remodeling during wound repair. This effect is probably through matrix metalloproteinase expression, thus exerting an extra effect on chronic wound regeneration. Conclusions: Physicians should be well aware of the possible fibronectin-induced effects in their future endeavors with PRP in chronic wound treatment. © 2013 International Society for Cellular Therapy.

Detecção in vitro da hepatite C (VHC) em plaquetas provenientes de indivíduoas não infectados expostas ao vírus

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Uso do curativo bio-ativo em pacientes com feridas de origem multifatorial

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Padronização das plaquetas preparadas in house para atividade do cofator da ristocetina

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Estudo da resposta de cultura utilizando-se soro bovino fetal e soro de plasma rico em plaquetas

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Potencial imunogênico dos curativos bioativos: aspectos imunhematológicos e leucoplaquetários

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Monitoramento da qualidade de hemocomponentes produzidos no Hemocecentro da FMB - UNESP

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB