Platelet concentration of plateletrich plasma from dogs, obtained through three centrifugation speeds

The platelets release at least 4 growth factors (Platelet Derived Growth Factor. â1 and â2 Transforming Growth Factors and Insulin-like Growth Factor) which are responsible for the migration and activation of cells that will start the reparation of soft tissues and bones. The Platelet Rich Plasma is an autogenous source for Growth Factors, obtained by platelet concentration by centrifuging total blood. This study aimed the comparison of platelet concentrations in plasma centrifuged in three different centrifugation speeds (1300, 1600 e 3200rpm), for the production of platelet rich plasma. Blood was drowned from 15 dogs, 40ml of each, and these were divided into four groups and centrifuged at 800rpm. Then the first group was centrifuged at 1300rpm, the second at 1600rpm, the third at 3200rpm and the last was used as control, named plasma. The mean percentage increase in the platelet concentration for each technique was: 1300 –183%, 1600 – 210% and 3200 – 222%. But in centrifugation at 3200rpm, platelets presented altered morphology and different sizes in every sample studied, which was understood as severe cell damage. It was concluded that the best technique for the preparation of the platelet rich plasma in dogs consisted of the previous centrifugation of the blood at 800rpm for ten minutes, and then the plasma should be separated. This plasma is then submitted to a second centrifugation of 1600rpm for 10 minutes, and the platelet poor plasma is separated and discharged.

Plaquetas liberam ao menos quatro fatores de crescimento ( Fator de Crescimento derivado de Plaquetas, Fatores de transformação de crescimento â1 and â2 e Fator de crescimento semelhante a insulina) responsáveis pela migração e ativação de células que iniciarão os processos de reparação de tecidos moles e ossos. O Plasma Rico em Plaquetas é fonte autógena de fatores de crescimento, obtida pela concentração das plaquetas através de centrifugação de sangue total. Este estudo visa a comparação das concentrações plaquetárias no plasma obtidas por três diferentes velocidades de centrifugação (1300,1600 e 3200 rpm), para produção de Plasma Rico em Plaquetas. 40 ml de sangue total foram retirados de cada animal, divididos em quatro grupos, e centrifugados inicialmente a 800 rpm. A seguir, as amostras do primeiro grupo foram centrifugadas a 1300 rpm, as do Segundo a 1600 rpm, as do terceiro a 3200 rpm e as do quarto grupo foram usadas como controle, denominadas plasma. O aumento médio da porcentagem na concentração de plaquetas para cada técnica foi: 1300- 183%, 1600 - 210% e 3200 - 222%. No entanto, a centrifugação a 3200 rpm, as plaquetas apresentaram a morfologia alterada e tamanhos diferentes em cada amostra estudada, que foram compreendidas como danos celulares severos. Como conclusão deste estudo, obteve-se que a melhor técnica para a preparação do plasma rico em plaquetas de cães consiste na centrifugação precedente do sangue em 800 rpm por dez minutos, separando o plasma, sendo este submetido a uma segunda centrifugação de 1600 rpm por 10 minutos, separando e desprezando o plasma pobre em plaquetas.

Spin doctors: new innovations for centrifugal apheresis.

The preparation of plasma from blood has a long history dating back to the early 1900s when the concept of blood washing replaced the traditional blood letting. Over the next 57 years landmark discoveries such as centrifugal and membrane filtration systems led to different and rapid plasma, solute, and cell separation. These were not singular events but rather events influenced by the converging chemical, physiological, and engineering advances that have characterized the latter half of the 20th century. These events have led to entire new fields of biomedical research. The biotechnology for on-line plasma separation and plasma treatment has opened a new era, expanding the application of extracorporeal technology to modern therapeutic medicine. The association of biochemical or cellular abnormalities with various disease states provides the rationale for therapeutic plasma exchange (the removal of large amounts of patient's plasma, alone or with replacement with crystalloid) and therapeutic cytopheresis (removal of cellular elements). The purpose of this review is to provide a historical picture of the innovative ideas of the spin doctors and their devices, which predate the centrifugal blood and cell separators commonplace to any hospital or blood bank worldwide. The emphasis is to define the historical events and their impacts on the development of centrifugal devices and apheresis technologies.

Concentration of sputum by cytocentrifugation for preparation of smears for detection of acid-fast bacilli does not increase sensitivity of the fluorochrome stain.

To evaluate the usefulness of cytocentrifugation for detection of acid-fast bacilli (AFB) in sputum specimens, we compared this method to a traditional concentration method for the preparation of smears. A total of 844 sputum specimens (from 579 patients) of adequate volume that were submitted for detection of mycobacteria were evaluated. A portion of each specimen was used for cytocentrifugation; the remainder was processed by our decontamination-concentration protocol (2% sodium hydroxide-N-acetyl-L-cysteine; centrifugation at 3,600 x g for 15 min) for preparation of smears and culture. All smears were stained with auramine O. Ninety-four cultures from 46 patients gave positive results, and AFB were seen in one or both smears from 53 specimens; 3 of the latter specimens (positive by both smear methods) were culture negative. Of the 50 AFB smear-positive and culture-positive specimens, 46 were smear positive by traditional concentration, and 47 were positive by the cytocentrifugation smear (P, not significant). Cultures of all specimens that were smear positive by only one method grew nontuberculous mycobacteria. The routine use of cytocentrifugation for concentrating sputum specimens increases the cost of smear preparation but does not increase detection of AFB by auramine O staining; however, it would be useful in handling emergent requests for AFB smears.

The effect of the addition of methylene blue on the fatigue strength of Simplex P bone-cement.

To aid in cement removal during revision arthroplasty, it has been proposed to add methylene blue to bone cement to provide contrast between the cement and bone. However, it is essential that the fatigue strength of the cement not be reduced by the addition of the methylene blue. The effect of adding 1 mL of an aqueous 1% solution of methylene blue to one pack of Simplex P prepared in the standard fashion (uncentrifuged) was studied. We also measured the fatigue properties of centrifuged Simplex P with three different methylene blue preparations. We studied adding 1 mL of an aqueous 1% solution of methylene blue, 0.5 g of methylene blue powder, and 0.1 mL of a 10% solution of methylene blue per pack of Simplex P bone cement. Adding 1 mL of a 1% methylene blue solution to 40 g of Simplex P without centrifuging the cement after mixing produced a cement with a mean fatigue life comparable to the uncentrifuged Simplex P without the methylene blue. However, the fatigue data scatter was higher for the uncentrifuged methylene blue preparation. The optimum methylene blue impregnated cement preparation was produced by adding 1 mL of a 1% methylene blue solution to 40 g of Simplex P powder, mixing with chilled monomer, and centrifuging for 60 s. Sterile 1 mL vials of 1% methylene blue solution are available in the operating room.(ABSTRACT TRUNCATED AT 250 WORDS)