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Clinics ; 74: e1132, 2019. tab, graf
Article in English | LILACS | ID: biblio-1019702


OBJECTIVE: To describe and analyze a new protocol for the extraction of platelet-rich plasma (PRP) for use in clinical practice and compare this technique with methods that have been previously described in the medical literature. METHODS: We extracted PRP from 20 volunteers using four different protocols (single spin at 1600 ×g, single spin at 600 ×g, double spin at 300 and 700 ×g, and double spin at 600 and 900 ×g). In another group of 12 individuals, we extracted PRP with our new technique (named 'turn down-turn up') consisting of a double spin (200 ×g and 1600 ×g) closed system using standard laboratory equipment (including an ordinary benchtop centrifuge), where the blood remained in the same tube during all processes, reducing the risk of contamination. Platelet counts adjusted to baseline values were compared using analysis of covariance (ANCOVA). RESULTS: Using the four previously described protocols (mentioned above), we obtained concentrations of platelets that were 1.15-, 2.07-, 2.18-, and 3.19-fold greater than the baseline concentration, respectively. With the turn down-turn up technique, we obtained a platelet count that was 4.17-fold (95% confidence interval (CI): 3.09 to 5.25) greater than the baseline platelet count (p=0.063 compared with the double spin at 600 and 900 ×g method). The total cost of the disposable materials used in the extraction process was less than US$10.00 per individual. CONCLUSION: In the present study, we described a simple and safe method for obtaining PRP using low-cost devices.

Humans , Male , Adult , Middle Aged , Centrifugation/methods , Clinical Laboratory Techniques/methods , Platelet-Rich Plasma , Platelet Count , Time Factors , Centrifugation/economics , Centrifugation/standards , Reproducibility of Results , Cost-Benefit Analysis , Clinical Laboratory Techniques/economics , Clinical Laboratory Techniques/standards
Rev. Soc. Bras. Med. Trop ; 52: e20180505, 2019. tab, graf
Article in English | LILACS | ID: biblio-1041570


Abstract INTRODUCTION: The microscopic examination of microhematocrit tubes (mHCT) has been proposed as the gold standard for acute and congenital Chagas disease diagnosis. We compared different mHCT methodologies detecting T. cruzi parasites in the blood. METHODS: The rotating method, water mount, and immersion oil methods were compared for their suitability, sensitivity, and specificity. RESULTS: The rotating method was easier, faster, and more sensitive than the others with 100% specificity. CONCLUSIONS: The rotating method is feasible for laboratory technicians with standard training in microscopic techniques and is recommended for the diagnosis of acute Chagas disease in primary health care facilities.

Humans , Animals , Trypanosoma cruzi/isolation & purification , Centrifugation/methods , Chagas Disease/diagnosis , Parasitemia/diagnosis , Capillary Tubing , Hematocrit/methods , Sensitivity and Specificity , Chagas Disease/parasitology , Chagas Disease/blood , Parasitemia/parasitology , Clinical Laboratory Services
J. oral res. (Impresa) ; 7(9): 406-411, ene. 2, 2018. tab
Article in English | LILACS | ID: biblio-1121133


Introduction: the habit of smoking alters the bone healing process, a problem to consider in oral surgery. objective: to evaluate the bone healing of dental alveoli with PRP obtained using single or double centrifugation in smokers. methodology: extraction of mandibular third molars was performed in a study population divided into smoking group (A), which had PRP applied with the protocol using a single centrifugation step (P1C) in the alveolus of tooth 38 and the protocol of double centrifugation (P2C) in alveolus of tooth 48; a smoking group(B), to whom no PRP was applied; and a non-smokers group (C) to whom PRP was applied obtained using P1C and P2C protocol. radiographic examination was performed at 8, 30 and 60 days post procedure. results: thirty patients met the criteria, 57 percent were female. when evaluating bone healing between the group of smokers and non-smokers, statistically significant differences were observed in the non-smoking group at 30 and 60 days, showing better results with the P2C protocol (p<0.005). statistically significant differences were found at 30 and 60 days (p<0.005), both with the P1C and P2C when comparing bone healing of group A and B. conclusions: bone healing in the alveoli of mandibular third molars that which PRP applied was higher in non-smoking patients, compared with the group of smokers. bone healing was better in patients smokers to whom PRP was applied than those without PRP treatment. regarding the method of obtaining PRP, bone healing was better when a double centrifugation protocol (P2C) was applied.

Humans , Male , Female , Adolescent , Adult , Young Adult , Bone Regeneration , Tooth Socket , Platelet-Rich Plasma , Smokers , Molar, Third , Tobacco Use Disorder/complications , Tooth Extraction , Centrifugation/methods , Colombia
Pesqui. vet. bras ; 37(3): 215-220, Mar. 2017. tab, graf, ilus
Article in Portuguese | LILACS, VETINDEX | ID: biblio-842060


O plasma rico em plaquetas (PRP) consiste em uma alta concentração de plaquetas em um pequeno volume de plasma, sendo, em média, quatro vezes maior que a concentração sérica. O uso de PRP é justificado pela alta concentração de fatores de crescimento presentes em grânulos no interior das plaquetas, que possuem diversas funções como proliferação celular, quimiotaxia, angiogênese e diferenciação celular, que ampliam o poder de reparação tecidual. Há diversos protocolos para obtenção do PRP em equinos descritos na literatura, dentre os quais destacam-se os de dupla centrifugação, os automatizados e os filtros. Há diferenças substanciais no conteúdo do PRP dependendo do seu método de obtenção, principalmente no que se diz respeito à quantidade de leucócitos, plaquetas e concentração de fatores de crescimento. Sendo assim, o objetivo deste estudo foi comparar a utilização do concentrado de plaquetas obtido por protocolo de dupla centrifugação e o obtido pelo filtro E-PET (Equine Platelet Enhancement Therapy), levando-se em consideração a concentração plaquetária e leucocitária final, a quantificação de fatores de crescimento (TGFß e PDGF-BB) e a facilidade de realização entre tais métodos. Utilizou-se nove animais para a obtenção de PRP por dupla centrifugação e através do filtro E-PET, não havendo diferença estatística (p>0,05) entre os métodos de obtenção em relação à concentração plaquetária e leucocitária, entretanto, houve diferença estatística (p=0,002; p=0,004, respectivamente) em relação a concentração de TGFß e PDGF-BB. Dessa forma, concluiu-se que o filtro E-PET mostrou-se um método mais efetivo, sendo possível sua utilização à campo, além de proporcionar uma maior concentração de fatores de crescimento TGFß e PDGF-BB.(AU)

The platelet-rich plasma (PRP) consists of a high concentration of platelets in a small volume of plasma, four times greater (average) than the serum concentration. The use of PRP is justified by the high concentration of growth factors present in granules in the platelets, which have several functions such as cell proliferation, chemotaxis, angiogenesis and differenciation, which extend the power of tissue repair. There are several protocols to obtain PRP in horses described in the literature, among which are highlighted the double centrifugation, automated and filters. There are substantial differences in the PRP content depending on its method of production, especially when it concerns the amount of leukocytes, platelets and concentration of growth factors. Thus, the aim of this study was to compare the use of platelet concentrates obtained by double centrifugation protocol and obtained by the filter E-PET (Equine Platelet Enhancement Therapy) taking into account the platelet and leukocyte final concentration, the quantification of growth factors (TGFß and PDGF-BB) and the facility to do those methods. Nine horses were used to obtain PRP by double centrifugation and through the E-PET filter, with no statistical difference (p>0.05) between the methods relative to the platelet and leukocyte concentration; however, there was statistical difference (p=0.002 and p=0.004 respectively) compared with the concentration of TGFß and PDGF-BB. It was concluded that the E-PET filter proved to be a more effective method possible to use in the field and to provide a higher concentration of growth factors (TGFß and PDGF-BB).(AU)

Animals , Centrifugation/methods , Horses/blood , Platelet-Rich Plasma , Proto-Oncogene Proteins c-sis , Transforming Growth Factors
Arq. neuropsiquiatr ; 74(10): 816-822, Oct. 2016. tab, graf
Article in English | LILACS | ID: lil-796832


ABSTRACT Objective To define how to best handle cerebrospinal fluid (CSF) specimens to obtain the highest positivity rate for the diagnosis of malignancy, comparing two different methods of cell concentration, sedimentation and cytocentrifugation. Methods A retrospective analysis of 411 CSF reports. Results This is a descriptive comparative study. The positive identification of malignant CSF cells was higher using the centrifuge than that using the Suta chamber (27.8% vs. 19.0%, respectively; p = 0.038). Centrifuge positively identified higher numbers of malignant cells in samples with a normal concentration of white blood cells (WBCs) (< 5 cells/mm3) and with more than 200 cells/mm3, although this was not statistically significant. There was no lymphocyte loss using either method. Conclusions Cytocentrifugation positively identified a greater number of malignant cells in the CSF than cytosedimentation with the Suta chamber. However, there was no difference between the methods when the WBC counts were within the normal range.

RESUMO Objetivo Definir qual a melhor forma de concentrar amostras de LCR para obter maior porcentagem de positividade para o diagnóstico de infiltração neoplásica. comparando dois métodos diferentes de concentração de células, sedimentação e citocentrifugação. Métodos Análise retrospectiva de 411 laudos de LCR. Resultados Estudo comparativo descritivo. A identificação de células neoplásicas no LCR foi mais elevada quando usada a citocentrífuga do que a câmara de Suta (28% vs 19,0%, respectivamente; p = 0,038). Centrifugação identificou maior número de células neoplásicas em amostras com concentração de células < 5 células/mm3 e superior a 200 células/mm3, embora não significativo. Não houve perda de linfócitos usando qualquer um dos métodos. Conclusões A citocentrifugação identificou um número maior de células malignas no LCR do que a sedimentação com a câmara de Suta. No entanto, não houve diferença entre os métodos quando as contagens de leucócitos estavam dentro do intervalo normal.

Humans , Male , Female , Infant , Child, Preschool , Child , Adolescent , Adult , Young Adult , Centrifugation/instrumentation , Centrifugation/methods , Central Nervous System Neoplasms/cerebrospinal fluid , Reference Standards , Reference Values , Specimen Handling/instrumentation , Specimen Handling/methods , Time Factors , Leukemia/cerebrospinal fluid , Cerebrospinal Fluid/cytology , Predictive Value of Tests , Reproducibility of Results , Retrospective Studies , Leukocyte Count
Einstein (Säo Paulo) ; 14(3): 391-397, July-Sept. 2016. tab, graf
Article in English | LILACS | ID: lil-796967


ABSTRACT Objective: To evaluate growth factors and cytokines in samples of platelet-rich plasma obtained by three different centrifugation methods. Methods: Peripheral blood of six individuals with no hematological diseases, aged 18 to 68 years, was drawn to obtain platelet-rich plasma, using the open method and commercial columns by Medtronic and Biomet. The products obtained with the different types of centrifugation were submitted to laboratory analysis, including pro-inflammatory cytokines and chemokines by flow cytometry assays, the concentration of fibroblast growth factors-2 (FGF-2) and transforming growth factor-beta1 (TGF-β1). Results: The diverse separation methods generated systematically different profiles regarding number of platelets and leukocytes. The Medtronic system yielded a product with the highest concentration of platelets, and the open method, with the lowest concentration of platelets. The results of cytokine analysis showed that the different types of centrifugation yielded products with high concentrations of interleukin 8, interleukin 1β. The open system resulted in a product with high levels of interleukin 6. Other cytokines and chemokines measured were similar between systems. The product obtained with the open method showed higher levels of TGF-β1 in relation to other systems and low FGF-2 levels. Conclusion: The formed elements, growth factors and cytokines in samples of platelet-rich plasma varied according to the centrifugation technique used.

RESUMO Objetivo: Avaliar fatores de crescimento e citocinas em amostras de plasma rico em plaquetas obtidas por três diferentes métodos de centrifugação. Métodos: Foi coletado sangue periférico de seis indivíduos, sem doença hematológica, com idades entre 18 e 68 anos, para obtenção de plasma rico em plaquetas, utilizando o método aberto e sistemas comerciais das empresas Medtronic e Biomet. Os produtos obtidos com os diferentes tipos de centrifugação foram submetidos às análises laboratoriais, incluindo citocinas próinflamatórias e quimiocinas, por meio de ensaios de citometria de fluxo, concentração do fator de crescimento fibroblástico-2 (FGF-2) e fator de crescimento transformador-beta1 (TGF-β1). Resultados: As diferentes centrifugações geraram perfis sistematicamente diferentes referentes ao número de plaquetas e de leucócitos. O sistema da Medtronic originou produto com a maior concentração de plaquetas, e o método aberto com a menor concentração de plaquetas. Os resultados da análise de citocinas demonstraram que os diferentes tipos de centrifugação originaram produtos com elevadas concentrações de interleucina 8 e interleucina 1β. O sistema aberto resultou em produto com elevados níveis de interleucina 6. As demais citocinas e quimiocinas mensuradas foram similares entre os sistemas. O produto obtido com o método aberto apresentou níveis superiores de TGF-β1 em relação aos demais sistemas e reduzidos níveis de FGF-2. Conclusão: Os elementos figurados, fatores de crescimento e citocinas, em amostras de plasma rico em plaquetas, variaram conforme a técnica de centrifugação utilizada.

Humans , Adolescent , Adult , Middle Aged , Aged , Young Adult , Cytokines/analysis , Intercellular Signaling Peptides and Proteins/analysis , Platelet-Rich Plasma/chemistry , Centrifugation/methods , Cytokines/blood , Interleukins/analysis , Interleukins/blood , Chemokines/analysis , Chemokines/blood , Intercellular Signaling Peptides and Proteins/blood , Rotator Cuff Injuries/surgery
Mem. Inst. Oswaldo Cruz ; 111(6): 411-413, June 2016. graf
Article in English | LILACS | ID: lil-784251


In cell culture, cell structures suffer strong impact due to centrifugation during processing for electron microscope observation. In order to minimise this effect, a new protocol was successfully developed. Using conventional reagents and equipments, it took over one week, but cell compression was reduced to none or the lowest deformation possible.

Animals , Aedes/ultrastructure , Dengue Virus/ultrastructure , Microscopy, Electron, Transmission/methods , Aedes/virology , Cell Culture Techniques , Centrifugation/methods , Chlorocebus aethiops , Fixatives , Indicators and Reagents , Vero Cells/ultrastructure
Clinics ; 70(2): 120-125, 2/2015. tab, graf
Article in English | LILACS | ID: lil-741425


OBJECTIVES: To explore the microendoscopic discectomy technique and inclusion criteria for the treatment of recurrent lumbar disc herniation and to supply feasible criteria and technical notes to avoid complications and to increase the therapeutic effect. METHODS: A consecutive series of 25 patients who underwent posterior microendoscopic discectomy for recurrent lumbar disc herniation were included. The inclusion criteria were as follows: no severe pain in the lumbar region, no lumbar instability observed by flexion-extension radiography and no intervertebral discitis or endplate damage observed by magnetic resonance imaging. All patients were diagnosed by clinical manifestations and imaging examinations. RESULTS: Follow-up visits were carried out in all cases. Complications, such as nerve injuries, were not observed. The follow-up outcomes were graded using the MacNab criteria. A grade of excellent was given to 12 patients, good to 12 patients and fair to 1 patient. A grade of excellent or good occurred in 96% of cases. One patient relapsed 3 months after surgery and then underwent lumbar interbody fusion and inner fixation. The numerical rating scale of preoperative leg pain was 7.4± 1.5, whereas it decreased to 2.1±0.8 at 7 days after surgery. The preoperative Oswestry disability index of lumbar function was 57.5±10.0, whereas it was 26.0±8.5 at 7 days after surgery. CONCLUSION: In these cases, microendoscopic discectomy was able to achieve satisfactory clinical results. Furthermore, it has advantages over other methods because of its smaller incision, reduced bleeding and more efficient recovery. .

Humans , Centrifugation/methods , Leukocytes, Mononuclear/metabolism , Transfection/methods , Cell Survival/physiology , Leukocytes, Mononuclear/cytology , RNA Interference/physiology , RNA, Small Interfering/genetics
Reprod. clim ; 30(2): 67-69, maio-ago. 2015. ilus
Article in Portuguese | LILACS | ID: biblio-973026


A azoospermia é definida como a ausência de espermatozoide no líquido seminal ejaculado pelo homem depois de aplicada a técnica de centrifugação em pelo menos duas amostras. Dada a importância de um diagnóstico correto da análise seminal para os casais, toda amostra que não apresentar espermatozoides no exame a fresco deve seguir em avaliação laboratorial. Com isso, o presente estudo tem como objetivo analisar os resultados de centrifugação de uma alíquota do sêmen ejaculado ou de todo o volume ejaculado de pacientes com diagnóstico de azoospermia para determinar qual o melhor método a ser empregado na análise seminal para esse grupo de pacientes.

The azoospermia is defined as the absence of sperm in the ejaculate by the seminal fluid man after centrifugation technique conducted in at least two samples. Given the importance of a correct diagnosis of the seminal analysis for couples, all sample no sperm present in fresh examination should follow in laboratory tests. Thus the present study aims to analyze the results of a spin rate of ejaculate or all of the ejaculate volume of patients with azoospermia to determine the best method to be used in semen analysis for this group of patients.

Male , Humans , Azoospermia/diagnosis , Semen Analysis/methods , Centrifugation/methods
Article in English | IMSEAR | ID: sea-163079


Aim: To study the presence of indoor mycoflora in A/c Buses to know the commuters risk of exposure to fungal spores. Place and Duration: Chennai Mofussil Bus Terminus (CMBT), Koyambedu, Chennai, India. Study was conducted from November 2011 to April 2012. Methodology: Airborne fungi from 50 A/c buses were studied using Reuter Centrifugal Sampler (Biotest, Germany), fungi from the surfaces of air vents through swab sample and bus seats by rubbing sterile petridishes on the seats. Sabourauds Dextrose Agar (SDA) was used for the isolation of fungi from different buses. The collected data were statistically analyzed. Results: A total of 38 species classified in 21 genera were recorded. Among which, Zygomycetes was represented by 4 species, Ascomycetes and Coelomycetes by single species each and the remaining belongs to Hyphomycetes. The genus, Aspergillus was represented by maximum number of species (11 species) followed by Penicillium (5 species). A total average of 713 CFU/m3 of air was recorded within the buses. Aspergillus niger was the first dominant fungi in the order of dominance followed by Chrysonilia sitophila, Alternaria alternata and Aspergillus flavus in that order. From the surface of bus seats, Aspergillus niger, A. flavus, Rhizopus stolonifer and A. japonicus were recorded as dominant. However, different mycofloral composition was recorded from air vents. Cladosporium chlorocephalum and Curvularia lunata dominated the surface of air vents. Conclusion: The study demonstrates the presence of potential fungal species which pose exposure risk to the immune compromised commuters.

Air Conditioning , Air Microbiology , Air Pollution, Indoor/adverse effects , Air Pollution, Indoor/analysis , Aspergillus niger/isolation & purification , Centrifugation/methods , Environmental Exposure , Fungi/isolation & purification , Humans , Motor Vehicles , Prevalence , Risk
Rev. Inst. Med. Trop. Säo Paulo ; 51(3): 163-167, May-June 2009. tab
Article in English | LILACS | ID: lil-517100


The purpose of this study was to evaluate the influence of variables in a flotation technique for the recovery of Toxocara canis eggs from soil. The trials were done under standardized conditions on one gram of previously sterilized soil samples contaminated with 200 eggs of T. canis. The following variables were evaluated in serial steps: sieving; type of wash; time of stirring; resuspension of sediment; solution flotation. Centrifuge-flotation in sodium nitrate (d = 1.20 g/cm3) was adopted as an initial technique, using Tween 80 (0.2%) and decinormal sodium hydroxide as solutions for washing the samples. Ten tests were done to compare the variables, using counting in triplicate. The sieving of the material reduced significantly the recovery of eggs (p < 0.001) and the number of eggs recovered was higher when the sediment was resuspended (p < 0.05). After standardization, flotation solutions sodium chloride, zinc sulfate, sodium dichromate, magnesium sulfate, and sodium nitrate (d = 1.20g/cm3) were compared. The best results were obtained by using zinc sulfate solution. In conclusion, the chances of recovering T. canis eggs from samples using flotation solutions can be increased by washing of soil twice using distilled water, and resuspension of sediment. On the other hand, the sieving procedure can drastically reduce the number of eggs.

Com o objetivo de avaliar a influência de variáveis na técnica de centrífugo-flutuação para a recuperação de ovos de Toxocara canis em solo, amostras de solo foram previamente esterilizadas e divididas em alíquotas de um grama e contaminadas com 200 ovos. Após contaminação, foram comparadas, em etapas seriadas, as variáveis: filtragem, tipo de lavagem e ressuspensão do material. Como ponto de partida, utilizou-se técnica com lavagem de solo em Tween 80 (0,2%) e solução de hidróxido de sódio 0,1N; ressuspensão; e centrífugo-flutuação em solução de nitrato de sódio (d = 1,20 g/cm3). Os ovos recuperados foram contados com 10 repetições e três leituras para cada repetição. A filtragem reduziu significativamente a recuperação de ovos em relação ao material não filtrado (p < 0,001), enquanto o número de ovos foi significativamente maior quando da ressuspensão do material (p < 0,05). Após padronização, as soluções de cloreto de sódio, dicromato de sódio, nitrato de sódio, sulfato de zinco, sulfato de magnésio foram comparadas. O sulfato de zinco mostrou os melhores resultados. Dessa forma, as chances de recuperação de ovos de T. canis podem ser ampliadas com um processo duplicado de lavagem do solo com água destilada e ressuspensão do sedimento, sendo que a filtragem reduz consideravelmente o número de ovos.

Animals , Soil/parasitology , Toxocara canis/isolation & purification , Centrifugation/methods , Parasite Egg Count/methods , Time Factors
Rev. Inst. Med. Trop. Säo Paulo ; 49(3): 135-138, May-June 2007. tab
Article in English | LILACS | ID: lil-454759


Progressive disseminated histoplasmosis (PDH) is an increasingly common cause of infection in patients with acquired immune deficiency syndrome (AIDS). We report 21 cases of PDH associated with AIDS diagnosed by lysis-centrifugation blood culture method. The most prevalent clinical findings were fever, weight loss, respiratory symptoms, and mucocutaneous lesions. Chest roentgenogram showed diffuse pulmonary infiltrates in 13 of 21 patients (62 percent). Brochoalveolar fluid has yelded positive culture in four patients only in medium with cycloheximide.

Histoplasmose progressiva disseminada (HPD) tem aumentado e é causa comum de infecção em pacientes com síndrome da imunodeficiência adquirida (Aids). Relatamos 21 casos de HPD associado com Aids diagnosticada pela técnica de hemocultivo por lise-centrifugação. Os achados clínicos mais prevalentes foram febre, perda de peso, sintomas respiratórios e lesões mucocutâneas. Raios X de tórax mostrou infiltrados pulmonares difusos em 13 dos 21 pacientes (62 por cento). Amostras de lavado broncoalveolar foram positivos em apenas 4 pacientes através de meio com cicloheximida.

Humans , Male , Female , Adult , AIDS-Related Opportunistic Infections/diagnosis , Blood/microbiology , Fungemia/diagnosis , Histoplasma/isolation & purification , Histoplasmosis/diagnosis , AIDS-Related Opportunistic Infections/microbiology , Culture Techniques , Centrifugation/methods , Fungemia/microbiology , Histoplasma/classification , Histoplasmosis/microbiology
Braz. j. vet. res. anim. sci ; 44(6): 435-440, 2007. tab, graf
Article in English | LILACS | ID: lil-510476


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.

Animals , Male , Female , Dogs , Platelet Activation/physiology , Centrifugation/classification , Centrifugation/statistics & numerical data , Centrifugation/methods , Centrifugation/veterinary , Platelet Aggregation , Platelet-Rich Plasma/metabolism
São Paulo; s.n; 2003. 81 p. tab, graf.
Thesis in Portuguese | LILACS | ID: lil-333575


A inativação dos microrganismos pelo processo de irradiação é influenciada por vários fatores, entre eles a composição química e o estado físico do substrato e a atmosfera envolvente. Amostras de hambúrguer de carne bovina contaminadas com um inóculo composto por três diferentes cepas de E. coli O157:H7 foram expostas à irradiação gama com doses entre zero e 5,0 kGy. A influência de dois níveis de gordura (10 por cento e 20 por cento), dois tipos de condimentos (sal e pimenta ou mistura de condimentos especial para produtos cárneos) e o tipo de embalagem (normal ou vácuo) na inativação deste patógeno foi investigada. Amostras irradiadas não inoculadas foram submetidas à análise sensorial...

Animals , Cattle , Escherichia coli O157 , Food Irradiation , Food Microbiology , Food Quality , Radiation Tolerance , Bacteriological Techniques , Centrifugation/methods , Food Samples , Meat , Microbiological Techniques
Rev. chil. tecnol. méd ; 22(1): 993-997, jul. 2002. ilus, tab
Article in Spanish | LILACS | ID: lil-342345


Mediante el uso de un método simple de sedimentación-centrifugación se detectaron estadios evolutivos de enteroparásitos de probable origen humano en 37 muestras de cursos de aguas de diversas localidades de Chile, entre los años 1994 y 1997. En 34 de las 37 muestras estudiadas (91,7 porciento) se observaron elementos parasitarios. La especie parasitaria mas frecuentemente hallada fue Giardia sp (97,0 porciento). Otros protozoos detectados fueron: Entamoeba coli(79,0 porciento), Endolimax nana(73,5 porciento) y Entamoeba histolytica(30,4 porciento). Con relación a los helmintos, se detectaron huevos de Hymenolepis nana en una muestra (3,0 porciento) y larvas de nematodes en el 79,4 porciento. El método de sedimentación-centrifugación descrito permitió pesquisar diversos estadios evolutivos de enteroparasitos de probable origen humano demostrándose contaminación de los cursos de aguas estudiados

Water Pollution/analysis , Eukaryota , In Vitro Techniques , Centrifugation/methods , Formaldehyde , Sedimentation , Water , Water Samples
Rev. chil. infectol ; 19(3): 167-173, 2002. ilus, tab
Article in Spanish | LILACS | ID: lil-326039


El diagnóstico rápido de microorganismos presentes en fluidos corporales estériles es de gran importancia clínica. La tinción de Gram constituyela principal herramienta para el diagnóstico de estas infecciones, pero la sensibilidad de está técnica varía segín el tipó de muestray la carga bacteriana presente en ella. La concentración de la muestra previa a la tinción, mejora el rendimiento pero requiere volúmenes significativos de la muestra. La citocentrifugación resulta útilya que requiere de escaso volumen de muestra y permite obtener preparaciones uniformemente concentradas. Con el objetivo de evaluar la cito centrifugación en el diagnóstico de fluidos corporales, se estudiaron 52 muestras de fluidos de cavidades estériles recividas en el Laboratorio de Urgencia del Servicio de Laboratorios Clínicos de la Red de Salud UC. Las muestras fueron separadas para centrifugación convencional (CC) a 3000 rpm por 5 minutos (centrifuga Jouan CR3i r) y para citocentrifugación (CT) a 2000 rpm por 10 minutos (Citocentrifuga Cytospin Shandon Inc r). Del sedimento obtenido por CC se realizó un frotis para tición de Gram y cultivo. De la CT se obtuvo una mono capa celular concentrada en un área de 6 mm de diámetro para tinción de Gram. Ambos frotis fueron leídos por el mismo observador. De las 52 muestras analizadas, 18 fueron sugerentes de infección clínica. La sensibilidad para CT v CC fue de 89 por ciento y 61 por ciento, respectivamente. La especificidad fue de 100 por ciento para ambas técnicas. En una evaluación cuantitativa de la celularidad de las muestras, se observó un aumento de los leucocitos en la CT con respecto a CC. Estos resultados muestran que la CT puede ser de gran ayuda en el diagnóstico rápido de las infecciones de fluidos corporales con baja carga bacteriana. Presenta una mayor sensibilidad y facilita la visualización de bacterias, especialmente en muestras con bajo recuento celular

Humans , Centrifugation/methods , Body Fluids/microbiology , Clinical Laboratory Techniques , Culture Media , Sensitivity and Specificity
Säo Paulo; s.n; 2002. 164 p. tab, graf.
Thesis in Portuguese | LILACS | ID: lil-317082


O comportamento das enzimas xilose redutase (XR) e xilitol desidrogenase (XDH) da levedura Candida guilliermondii FTI 20037 foi avaliado durante a produçäo de xilitol a partir de hidrolisado hemicelulósico de bagaço de cana-de-açúcar, em sistema descontínuo alimentado. Foram empregadas diferentes concentrações de xilose no meio fermentado (S0) e no meio de alimentaçäo (Si), controles de pH e aeraçäo. Os experimentos foram conduzidos no fermentador BIOFLO III com volume útil de 1,25 1, a 30ºC e 300rpm. Utilizando-se planejamento estatístico e metodologia de superfície de resposta foi possível verificar que o S0 e Si säo significativas sobre a atividade da XR a um nível de 95 por cento de confiança...

Enzyme Activators , Food Additives , Food Technology , In Vitro Techniques , Sweetening Agents , Xylitol , Xylose , Centrifugation/methods , Culture Media , Spores, Fungal/growth & development , Fermentation/physiology
Lecta-USF ; 18(1): 65-73, jan.-jun. 2000. tab, graf
Article in Portuguese | LILACS | ID: lil-299886


Foram analisadas, para comparação qualitativa, 75 amostras fecais pelos métodos de centrífugo-flutuação em sulfato de zinco e centrífugo-sedimentação em formol-éter, preconizados respectivamente por Faust e cols. e pr Ritchie. Nesse último utilizou-se como alternativa o acetato de etila. Os dados obtidos demostraram que a técnica proposta por Ritchie mostra-se mais sensível à detecção de cistos de protozoários e igualmente sensível a ovos pouco densos de helmintos do que a técnica proposta por Faust e cols. Apresenta ainda outras vantagens como fixação do material, menor tempo de preparação, execução simples, análise microscópica que pode ser realizada algum tempo após a preparação, custo equivalente e maior concentração de organismos. O acetato de etila, quando comparado com o éter etílico na técnica de Ritchie, demonstrou ser um bom substituto, pois além de apresentar a mesma eficácia na concentração de formas parasitárias, é um produto mais adequado para trabalhos em laboratórios.

Ether , Feces , Diagnostic Techniques and Procedures , Centrifugation/methods , Eukaryota , Parasitic Diseases , Laboratory Chemicals/administration & dosage
Rev. Hosp. Matern. Infant. Ramon Sarda ; 19(2): 60-6, 2000. tab, graf
Article in Spanish | LILACS | ID: lil-278648


El manejo y pronóstico perinatal de los embarazos de alto riesgo se basa principalmente en la estimación certera de la madurez pulmonar fetal. Objetivos. 1) Principal: evaluar la concordancia entre el Conteo de Cuerpos Lamelares (CCL) en Líquido Amniótico (LA) y el Test de Clements. 2) Secundario: evaluar la capacidad operativa del CCL en LA como predictor de madurez pulmonar fetal. Material y métodos. El estudio incluyó 111 casos de muestras de LA de embarazadas de edades gestacionales entre 30 y 42 semanas (media 36,1 semanas; DS 3,7). Se realizaron los cuatro tests que el laboratorio efectúa rutinariamente para evaluar maduración pulmonar: Test de Clements, Test de Freer (Ft50), Foam Stability Index (FSI) y Lectura Espectrofotométrica a 600 nm. A cada una de las muestras se le efectuó el CCL según técnica. Resultados. Se calcularon los siguientes Indices Diagnósticos: Prevalencia del Clements Positivo, Prevalencia del Clements Negativo, Falsos Positivos, Falsos Negativos, Sensibilidad y Especificidad. Se calculó la Eficiencia Pronóstica: Valor Predictivo de la Prueba Positiva, Valor Predictivo de la Prueba Negativa, Eficiencia de la Prueba, Razones de Verosimilitud Positiva y Negativa y Errores Pronósticos Positivo y Negativo. Conclusiones. El CCL contrastado con los tests biofísicos para madurez pulmonar demostró un moderado grado de correlación, elevada concordancia y eficiencia pronóstica, por lo que hemos incluido este test junto con nuestros parámetros para madurez pulmonar por su confiabilidad en conteos mayores de 30.000/mm3 y menores de 10.000/mm3 (esto obviaría el uso del IndiceL/E Lecitina/Esfingomielina, cromatografía), pero siempre acompañado de perfil tradicional. Además es un test rápido, de bajo costo, que requiere pequeño volumen de muestra y un instrumental accesible a la mayoría de los laboratorios de plaza.

Humans , Pregnancy , Amniotic Fluid , Prenatal Diagnosis/methods , Fetal Organ Maturity/physiology , Pregnancy, High-Risk , Lung/embryology , Respiratory Distress Syndrome, Newborn/prevention & control , Centrifugation/methods , Health Services Statistics
Acta cir. bras ; 15(supl.2): 63-4, 2000. ilus
Article in Portuguese | LILACS | ID: lil-282436


O objetivo deste trabalho foi avaliar a permeabilidade da membrana mitocondrial em animais submetidos a pré-condicionamento isquêmico, isquemia e reperfusão seguido de hepatectomia a 70 por cento. Foram utilizados 30 ratos Wistar divididos em 3 grupos de 10: Grupo Controle (fc), Grupo Isquêmico (fi) e Grupo Pré-condicionado (fp). Após o procedimento cirúrgico os animais foram sacrificados para a remoção do remanescente hepático (30 por cento) do qual foram isoladas as mitocôndrias para a realização dos estudos de permeabilidade da membrana mitocondrial interna através do intumescimento osmótico. Foi observado um aumento significativo do intumescimento osmótico mitocondrial do grupo fi em relação aos grupos fc e fp, sugerindo uma possível participação de espécies reativas do oxigênio no processo.

Animals , Rats , Liver/blood supply , Ischemia/physiopathology , Ischemic Preconditioning , Mitochondria, Liver/physiology , Reperfusion Injury/physiopathology , Centrifugation/methods , Hepatectomy , Permeability/radiation effects , Rats, Wistar