SURE gel electrophoresis: A method for improved detection and purification of dilute nucleic acid samples.

Agarose gel electrophoresis is performed routinely by molecular biologists as both an analytical and a preparative method for characterization of nucleic acids. Gel analysis of highly dilute DNA solutions is challenging because of the limited sensitivity of detection available with conventional methods. In this study a new approach is described for concentrating samples directly within gels called SURE (successive reloading) electrophoresis. The approach involves loading of dilute samples multiple times into a single well, with each loading followed by a brief pulse of electrical current before the next sample is loaded. The procedure generates single bands created by molecular stacking that exhibit strongly enhanced signal intensities and minimal band broadening. Using optimized voltages and time intervals as many as 20 successive loadings could be performed and up to 800 µL could be loaded into a single well. Gel extraction and fluorescent quantitation demonstrated that approximately 97 % of the DNA from each loading was incorporated into the resultant band. Highly dilute DNA samples (<0.0007 ng per microliter) could be readily detected after six loadings. The method produced good results with either TAE or TBE as electrophoresis buffers, using loading dyes with or without SDS, and in both minigels and large gels.

Electrophoresis of Amplicons is a Better Method to Understand the Performance of Loop-mediated Isothermal Amplification Assay for Screening the Presence of Escherichia coli in Water.

SUMMARY: LAMP assay is widely used for detecting pathogens. We observed that the conventional and gradient polymerase chain reaction (PCR) could not detect the extracted Escherichia coli DNA; real-time PCR was able to detect up to a certain limit (10-8 bacterial dilution). At the same time, the LAMP assay could detect the bacteria at a much lower concentration (10-14 dilution). The results of the LAMP assay were evaluated using agarose gel electrophoresis and DNA binding dye (PicoGreen), but only gel electrophoresis gave reliable results. Therefore, we propose using electrophoresis-based amplicon detection to overcome the limitations of dye-based detection. We believe that this amplicon detection will go a long way in the screening of potable drinking water.

Different behavior of Ferguson plot between agarose and polyacrylamide gels.

In this study, we conducted Ferguson plot analyses using both agarose and polyacrylamide gels in native electrophoresis and SDS-PAGE. The results revealed intriguing differences in the behavior of bovine serum albumin (BSA) and other model proteins. Specifically, BSA exhibited Ferguson plot slopes that were dependent on the oligomer size in agarose native gel electrophoresis, while such size-dependent behavior was not observed in native-PAGE or SDS-PAGE. These findings suggest that Ferguson plot analysis is a suitable approach when using agarose gel under the electrophoretic conditions employed in this study. Furthermore, our investigation extended to model proteins with acidic isoelectric points and larger molecular weights, namely Ferritin and caseinolytic peptidase B (ClpB). Notably, these proteins displayed distinct Ferguson plot slopes when subjected to agarose gel electrophoresis. Intriguingly, when polyacrylamide gel was employed, ClpB exhibited multiple bands, each with its unique Ferguson plot slope, deviating from the expected behavior based on molecular size. This divergence in Ferguson plot characteristics between agarose and polyacrylamide gels points to an interesting and complex interplay between protein properties and gel electrophoresis conditions.

Serum protein electrophoresis in European mink (Mustela lutreola): reference intervals and comparison of agarose gel electrophoresis and capillary zone electrophoresis.

BACKGROUND: Knowledge of reference intervals for blood analytes, including serum protein fractions, is of great importance for the identification of infectious and inflammatory diseases and is often lacking in wild animal species. MATERIAL AND METHODS: Serum samples were obtained from European minks enrolled in the breeding program (n = 55). Agarose gel electrophoresis (AGE) and capillary zone electrophoresis (CZE) were used to separate and identify protein fractions. Albumin, α1, α2, ß, and γ-globulins fractions were identified in all mink sera by both electrophoresis methods. Reference intervals (90% CI) were determined following the 2008 guidelines of the Clinical Laboratory Standard Institute. The methods were compared using Passing-Bablok regression, Bland-Altman analysis, and Lin's concordance correlation. RESULTS: A significant bias was found between methods for α1, α2, and γ-globulin. Lin's concordance correlation was considered unacceptable for α1, α2, and ß-globulins. Differences for gender between methods were found for albumin and α2-globuins, which were higher for males than females. γ-globulins were higher for adults than young minks using both methods; however, α1 and α2-globulins were lower. CONCLUSION: Both methods are adequate for identifying serum protein disorders, but the AGE and CZE methods are not equivalent. Therefore, reference intervals for each technique are required.

Methods to Quantitatively Measure Topological Changes Induced by DNA-Binding Proteins In Vivo and In Vitro.

Agarose gel electrophoresis in the presence of chloroquine (an intercalating agent) can be used to resolve and characterize the population of topoisomers present in supercoiled plasmid DNA. Here, we describe how chloroquine gel electrophoresis can capture changes in the topoisomer distribution of plasmid DNA that bears a recognition site for a given protein, if that plasmid is isolated from cells producing the protein of interest. We also describe two complementary in vitro assays, which can be used to capture transient changes in DNA supercoiling caused when the purified protein of interest engages its recognition site. These are the topoisomerase I-mediated relaxation assay (TMRA) and the ligase-mediated supercoiling assay (LMSA). Together, these in vivo and in vitro methods allow the capture and measurement of changes in DNA topology that are triggered by DNA-binding proteins, especially those that multimerize on or spread along DNA.

A Particle Gel Assay for Detection of Intracellular Hepatitis B Virus Subviral Particles in Cultured Cells.

Chronic hepatitis B virus (HBV) infection is due to the failure of host immune system to resolve the viral infection. Accordingly, restoration or reconstitution of a functional antiviral immune response to HBV is essential to achieve durable control of HBV replication leading to a functional cure of chronic hepatitis B (CHB). Noninfectious subviral particles (SVPs), comprised of HBV surface antigen (HBsAg), are the predominant viral products secreted by HBV-infected hepatocytes. The high levels of SVPs in the circulation induce immune tolerance and contribute to the establishment of chronic HBV infection. The current standard-of-care medications for CHB efficiently suppress HBV replication but fail to reduce the levels of HBsAg in majority of treated patients. Further understanding the mechanisms underlying SVP morphogenesis, secretion and regulation by viral and host cellular factors are critical for the discovery of therapeutics that can inhibit SVP production and/or induce the degradation of HBV envelope proteins. We describe herein a protocol for intracellular SVP detection by a native agarose gel electrophoresis-based particle gel assy. The method is suitable for quantitative detection of intracellular HBV SVPs and can be applied in dissecting the molecular mechanism of SVP morphogenesis and the discovery of antiviral agents targeting SVP formation in hepatocytes.

Técnicas electroforéticas en el HYDRASYS 2. Utilidad diagnóstica en diferentes enfermedades / Electrophoretic techniques in HYDRASYS 2. Diagnostic usability in different diseases

Se presentan los resultados de la estandarización de las técnicas de electroforesis de hemoglobina (Hb), isoenzimas de la deshidrogenasa láctica (LDH) y proteinuria en el equipo Hydrasys 2, así como el estudio de pacientes atendidos en el Instituto de Hematología e Inmunología y en otros centros hospitalarios del país. Se realizó el diagnóstico de 149 portadores de hemoglobinopatías (AS, AC, b talasemia heterocigótica, variante rápida), 60 enfermos (SS, SC, CC), 24 pacientes con a talasemia o deficiencia de hierro y se cuantificó la hemoglobina fetal a 93 casos con hemoglobinopatía S. Se determinaron los valores normales de actividad e isoenzimas de LDH en la población mediante el estudio de 50 donantes de sangre. En los pacientes con anemia drepanocítica se encontró un aumento significativo de la isoenzima 1 (p= 0,000) y disminución de isoenzimas 3 (p= 0,002). Se realizó el estudio de proteínas en orina a 8 pacientes con enfermedades hematológicas que presentaron microalbuminuria al menos en 2 ocasiones, con concentraciones ³ 0,04 g/L. En 2 pacientes el resultado fue normal; en 2 se encontraron proteínas de origen tubular; y en otros 2, proteínas de origen glomerular

We present the results of the standardization of the techniques of electrophoresis of hemoglobin (Hb), lactate dehydrogenase isoenzymes (LDH) and proteinuria in HYDRASYS 2 equipment, and the study of patients treated at the Institute of Hematology and Immunology and other hospitals in the country. 149 hemoglobinopathies carriers were diagnosed (AS, AC, b thalassemia heterozygous fast variant), 60 patients (SS, SC, CC), 24 patients with athalassemia or iron deficiency. Fetal hemoglobin was quantified in 93 cases with hemoglobinopaty S. Normal values of activity and LDH isoenzymes were determined in the population through the study of 50 blood donors. In patients with sickle cell anemia we found a significant increase in isoenzyme 1 (p=0.000) and isozyme 3 decreased (p=0.002). We performed the study of proteins in urine in 8 patients with hematologic malignancies who had microalbuminuria at least 2 times, with concentrations ³ 0.04 g / L. In 2 patients the results were normal, in 2 proteins were tubular origin, and in 2, proteins of glomerular origin

Perfil eletroforético das proteínas séricas de serpentes Crotalus durissus terrificus (cascavel) criadas em cativeiro / Serum protein electrophoresis profile of the rattlesnake Crotalus durissus terrificus kept in captivity

As serpentes peçonhentas dos gêneros Bothrops e Crotalus têm sido mantidas em cativeiro visando à extração de venenos para a produção de imunobiológicos. O conhecimento da fisiologia desses animais e as alterações na concentração de proteínas e suas frações séricas são importantes para a identificação precoce de importantes enfermidades que cursam com estados de hipoproteinemia e hiperproteinemia. O objetivo do trabalho foi determinar a concentração de proteína total e o perfil eletroforético das proteínas séricas de serpentes Crotalus durissus terrificus (cascavel) criadas em cativeiro. Foram colhidas amostras de sangue da veia coccígea ventral de 21 serpentes adultas e sadias, divididas em dois grupos: Grupo 1 de 12 machos com peso médio de 588,89±193,55g, e Grupo 2 de nove fêmeas com peso médio de 708,33±194,04g. A proteína total sérica foi determinada pelo método de refratometria e a eletroforese em gel de agarose. Obtiveram-se valores da proteína total sérica (g/dL) de 4,51±0,50 para machos e de 4,82±0,72 para fêmeas, e para machos e fêmeas de 4,64±0,61. Foram identificadas pela eletroforese quatro frações protéicas (g/dL): albumina, a, b, g-globulinas e calculada a relação albumina:globulina. As serpentes fêmeas apresentaram maiores valores para as variáveis, albumina e para a relação albumina/globulina (AG) diferindo significativamente (P<0,05) do grupo de machos, porém sem significado clínico.

The poisonous snakes of the genera Crotalus and Bothrops have been kept in captivity with the purpose of extracting poison for the production of immunobiological. Knowledge of the physiology of these animals and serum proteins concentration changes are important for early identification of major diseases which lead to states of hypoproteinemia and hyperproteinemia. The objective was to determine the concentration of total protein and serum protein electrophoresis profile of Crotalus durissus terrificus (rattlesnake) in captivity. Blood samples were taken from the ventral coccygeal vein of 21 adult and healthy snakes divided into groups: Group 1 with 12 males, weighing in average 588.89±193.55g, and Group 2 with nine females, weighing in average 708.33±194.04g. The total serum concentration of protein was determined by the method of refractometry and agarose gel electrophoresis. The total protein values in the serum for females was 4.82±0.72, for males 4.51±0.50 and males and females 4.64±0.61, identified by four fractions (g/dL): albumin, a, b and g-globulin. Additionally the albumin/globulin ratio was calculated. The female snakes showed higher values for the variables, albumin and the albumin/globulin (AG) differed significantly (P<0.05) from the group of male snakes, but there was no clinical significance.

Characterization of cellulolytic activities of Bjerkandera adusta and Pycnoporus sanguineus on solid wheat straw medium / Caracterización de las actividades celulolíticas de Bjerkandera adusta y Pycnoporus sanguineus en un medio sólido de paja de trigo

Cellulolytic properties of two white rot fungi, Bjerkandera adusta and Pycnoporus sanguineus, cultivated on wheat straw agar medium, were characterized and compared. Optimal growing parameters for maximum enzyme production for both fungi were wheat straw medium pH 5 and 28ºC. B. adusta showed, on the 6th day of culture, carboxymethylcellulose (CMC)ase activity levels 1.6 times higher than maximal P. sanguineus activity, achieved on the 8th day. B. adusta supernatants also displayed higher activity levels towards xylan (3.6-fold) compared to those of P. sanguineus. However, enzymes from P. sanguineus were more robust resisting one hour incubation at high temperatures (up to 80ºC), and exhibiting activity and stability in pH range from 2 to 8. Cellulolytic activities, with molecular masses ranging from 25 to 90 kDa, from the two species were detected in zymograms.

Proteinograma sérico de veados-catingueiro (Mazama gouazoubira) criados em cativeiro obtido por eletroforese em gel de agarose e de poliacrilamida (SDS PAGE) / Serum protein concentrations of captive brown brocket deer (Mazama gouazoubira) determined by means of agarosis and sodium dodecyl sulphate-polyacrylamide (SDS-PAGE) gel electrophoresis

The serum protein concentrations of brown brocket deer (Mazama gouazoubira) obtained by agarosis gel and sodium dodecyl sulphate-polyacrylamide (SDS-PAGE) gel were determined from blood samples of ten adult healthy animals (six females and four males), monthly collected in the morning, during 12 months. The animals, maintained in individual stable and protected from noise, received ad libitum a diet of comercial ration and green roughage. Serum protein concentrations in agarosis gel revealed the presence of four protein fractions: albumin, alphaglobulin, betaglobulin, and gammaglobulin. Only serum concentrations of albumin were influenced by season, being values in spring higher than values in summer (4.15 x 3.64g/dl). Serum concentrations of albumin (4.05 x 3.75g/dl) were higher for female and alphaglobulin (0.39 x 0.53g/dl) werehigher for males. Results showed 34 proteins with molecular weights ranging from 18kD to 165kD. Significant differences between at least two seasons were found on values of 11 proteins. In conclusion, on account of the 10 animals been maintained in the same physical space and submitted to the same handling system, physiological variations, which are characteristic of this species, can be apointed as the reason of these differences.

Screening of RET gene mutations in multiple endocrine neoplasia type-2 using Conformation Sensitive Gel Electrophoresis (CSGE)

Multiple endocrine neoplasia type 2 (MEN2) is an autosomal dominant inherited tumor syndrome caused by RET proto-oncogene germline mutations (RET). Here we tested the Conformation Sensitive Gel Electrophoresis (CSGE) as a screening method for RET hot-spot mutations. Seven MEN2 families were studied by direct sequencing analysis, CSGE and Single Strand Conformational Polymorphism (SSCP). Using CSGE/SSCP, we were able to detect four out of five types of RET mutations verified by sequencing analysis: Cys620Arg, Cys634Arg, Cys634Tyr, and Met918Thr, furthermore a missense substitution at codon 648 (Val648Ile). RET polymorphisms 691 and 769 were also verified. Data obtained using CSGE/SSCP were fully concordant. We conclude that CSGE showed to be a sensitive, fast, low-cost, and simple procedure to detect RET mutations in codons which are reported as the most prevalent RET variants (~ 95 percent) in large MEN2 series. As to the Val804Met mutation, this method still needs to be optimized.

A neoplasia endócrina múltipla tipo 2 (NEM2) é uma síndrome tumoral herdada por mutações germinativas no proto-oncogene RET (RET). Analisamos a aplicação do método Eletroforese em Gel Sensível à Conformação (CSGE) no rastreamento de mutações hot spots do RET. Sete famílias com NEM2 foram rastreadas pelo seqüenciamento gênico, CSGE e análise do Polimorfismo Conformacional de Cadeia Simples (SSCP). Usando ambas as metodologias de rastreamento, identificamos quatro dos cinco tipos de mutações verificadas pelo seqüenciamento: Cys620Arg, Cys634Arg, Cys634Tyr e Met918Thr, além da variação gênica Val648Ile. Das análises englobando mutações hot spots do RET, 90,6 por cento concordaram com o seqüenciamento genético (incluindo a variação gênica Val648Ile). Polimorfismos nos códons 691 e 769 foram documentados. Os dados obtidos por CSGE/SSCP foram totalmente concordantes. Concluímos que o CSGE revelou ser metodologia sensível, rápida, de fácil execução e baixo custo no rastreamento de mutações nos códons associados à grande maioria (~ 95 por cento) dos pacientes com NEM2.

Análise da composição do matriz extracelular das camadas urotelial e muscular da bexiga de mulheres em diferentes idades / Analysis of the extracellular matriz of urothelial and muscle layers of the bladder in women at different ages

Acomplacência da bexiga depende de músculos lisos, fibras colágenas, fibras elásticas e suas relações. O objetivo deste trabalho é determinar a composição da matriz extracelular em amostras de bexigas normais através de análise bioquímica de colágeno e glicosaminoglicanos em amostras obtidas de mulheres em diferentes grupos de idade, analisando separadamente as camadas urotelial e muscular. Avaliamos 17 amostras de bexiga divididas em três grupos: infância (N=5), menacme (N=6) e pós-menopausa (N=6). As bexigas foram analisadas para concentração de GAG total e colágeno e para análise qualitativa de GAG por eletroforese em gel de agarose. Na camada muscular, não houve diferença entre os grupos tanto para GAG quanto para colágeno. Na camada urotelial, a análise da concentração de colágeno não mostrou diferença entre os grupos, mas a concentração de GAG no grupo da pós-menopausa (0.21 +- 0.12 ug de ácido hexurônico/mg de tecido seco) apresentou diferença em relação aos grupos do menacme (1.78 +- 1.62 ug de ácido hexurônico/mg de tecido seco) e da infância (2.29 +- 1.32 ug de ácido hexurônico/mg de tecido seco). Nosso trabalho concluiu que a concentração de GAG está substancialmente diminuída na cadama urotelial da bexiga de mulheres na pós-menopausa.

Bladder compliance is dependent on smooth muscle, collagen fibers, elastic fiber and their ratios. The luminal surface of the urothelium is covered by an adhering glycosaminoglycan (GAG) layer. The aim of this study was to determine the composition of the extracellular matrix (ECM) in normal samples of women bladders through biochemistry analysis of collagen and GAG on samples obtained from individuals from different age groups, analyzing separately the urothelial and muscular layers. We studied samples taken from bladders of 17 patients divided in three different groups: childhood (N=5), menacme (N=6) and menopause (N=6). Bladders were analyzed for total GAG and collagen concentration per mg dry tissue and for the contents of GAG species, as determined by agarose electrophoresis and reported as the percent of total sulfated GAG. In muscular layer, collagen and GAG concentration showed no difference between groups. In urothelial layer, collagen concentration showed no difference between groups but GAG concentration in menopause (0.21 +- 0.12 ug hexuronic acid/mg dry tissue) was different from menacme (1.78 +- 1.62 ug hexuronic acid/mg dry tissue) and childhood (2.29 +- 1.32 ug hexuronic acid/mg dry tissue). There was no difference between sulfated GAG in three groups. In conclusion, GAG concentration in urothelial layer was substantially lower in menopause women.

Rastreamento gênico da neoplasia endócrina múltipla tipo 2: experiência da Unidade de Endocrinologia Genética da USP / Genetic screening of multiple endocrine neoplasia type 2: experience of the USP Endocrine Genetics Unit

A neoplasia endócrina múltipla tipo 2 (NEM-2) é uma síndrome tumoral hereditária que compreende: carcinoma medular de tireóide, hiperparatiroidismo primário, feocromocitoma e outras doenças não-endócrinas. Desde a identificação das primeiras mutações missense no RET associadas ao NEM-2, a detecção de mutações no RET adquiriu grande impacto no tratamento clínico da NEM-2, tais como o pronto diagnóstico e tratamento do CMT. Atualmente a tireoidectomia total possibilita real cura dos casos de CMT nos quais os diagnósticos moleculares foram efetuados precocemente. Depois de identificadas as mutações no RET, os demais familiares devem ser rastreados para esta mutação utilizando-se métodos como DGGE, SSCP, enzima de restrição, seqüenciamento e mini-seqüenciamento gênico. Apresentamos uma breve revisão da nossa experiência com seqüenciamento gênico direto do RET e DGGE. Em 50 pacientes com NEM-2 analisados por ambas as técnicas, não encontramos falsos resultados, sugerindo que o DGGE é uma metodologia de rastreamento adequada para mutações no proto-oncogene RET.

Studies on prevalence of strongyloides infection in Holambra and Maceio, Brazil, by the agar plate faecal culture method

Foi feito levantamento sobre a prevalencia da infeccao por Strongyloides stercoralis em tres areas do Brasil, atraves do desenvolvimento de metodo de cultura de fezes (cultura em placa de agar). A infeccao por Strongyloides foi confirmada em 11,3 por cento de 432 pacientes examinados. A eficacia do diagnostico pela cultura em placa de agar foi de 93,9 por cento comparado com apenas 28,5 por cento e 26,5 por cento pelo metodo de Harada-Mori de cultura em papel de filtro e metodo de concentracao de fezes, quando amostras de fezes foram examinadas simultaneamente por estes tres metodos. Entre as 49 amostras positivas, aproximadamente 60 por cento foram confirmadas como positivas somente pela cultura em placa de agar. Estes resultados indicam que a cultura em placa de agar e um novo metodo sensivel para o diagnostico correto da infeccao cronica pelo Strongyloides

Molecular epidemiology of methicillin resistant Staphylococcus aureus isolated from newborns in a hospital in Rio de Janeiro, Brazil

Methicillin resistant Staphylococcus aureus (MRSA) is an organism that is frequently transmitted in hospitals and perinatal units. The MRSA is considered a public health problem in neonatology because of its strong potential for dissemination in the wards associated with high rates of morbidity and mortality. In this study we describe the bacteriological, epidemiological and molecular characteristics of MRSA isolated from anterior nares and blood cultures of newborns hospitalized in a public maternity hospital in the city of Rio de Janeiro, Brazil. The frequency of MRSA isolated from nasal swabs of newborns was 47.8 percent (43/90). The genetic analysis of MRSA strains from anterior nares, showed 8 different pulsed field gel electrophoresis patterns (PFGE). Upon analysis of PFGE patterns of the 12 MRSA strains isolated from blood cultures, 8 different patterns were observed, 9 (75 percent) strains were genetic related to nasal secretion isolates patterns. In conclusion, our data demonstrate the importance of screening of newborns for the presence of MRSA in Brazilian hospitals and the usefulness of genetic typing of these pathogen during epidemiologic studies. This should lead to a better knowledge on the significancy and spreading of MRSA in the hospitals

Método rapido para el análisis de variantes genomicas del virus del papiloma / Rapid method for variant genome analysis of papilloma virus

Se ha desarrollado un método rápido y eficiente para la extracción de ADN de virus del papiloma presente en tumores. La cantidad y la calidad del ADN extraído permitió realizar el análisis directo del genoma viral con tres enzimas de restricción. Se discute la utilidad de esta técnica para realizar estudios clínicos

Contenido de plásmidos em cepas de Azospirillum sp. / Plasmid content in Azospirillum strains

En este trabajo se describe el contenido de plásmidos de 27 cepas de A. brasilense y A. lipoferum aisladas de diferentes zonas del país y de distintas especies vegetales y se describen características de los métodos de extracción de plásmidos de alto peso molecular empleados. Casi todas las cepas presentaron entre uno y cuatro plásmidos, todos de alto peso molecular. Uno de ellos, de aproximadamente 100 Megadaltons, se encuentra en el 44% de las cepas analizadas. Aún no hay evidencias en cuanto a la información genética codificada por ellos

Crescimento homogêneo de trichomonas vaginalis em meio semi-sólido / Homogeneous growth of trichomonas vaginalis in a semi-solid culture medium

Apesar da Tricomoníase ser, geral, a doença sexualmente transmitida mais frequentemente diagnosticada, existem poucas informaçöes relacionadas a padronizaçäo de cultivo do agente etiológico em meio semi-sólido. No presente trabalho, 10 estirpes de Trichomonas vaginalis foram semeadas em meio semi-sólido de Diamaond modificado, estudando-se as concentraçöes de ágar, o inóculo e o tempo de incubaçäo que permitiam crescimento do parasita em todo o meio de cultura. Foi observado que inóculo de 10**5 ou 10**6 Trichomonas vaginalis por mililitro, concentraçäo de 0,6% de ágar e tempo de incubaçäo de 72 horas foram as condiçöes mais adequadas, para o crescimento homogêneo do referido agente, mediante a aplicaçäo da técnica do ágar-fundido

Detection of rotaviral antigen by immunoprecipitation in agarose gel

Cento e setenta e seis amostras fecais diarreicas originárias de crianças abaixo de dois anos de idade, acometidas de diarréia aguda, foram estudadas quanto à presença de antígeno de rotavírus, pela técnica de imunoprecipitaçäo em gel de agarose. A especificidade da técnica foi confirmada atavés da observaçäo do material eluído, das linhas de precipitaçäo, através da microscopia eletrônica, por coloraçäo negativa. Destas amostras, 53,4% (94/176) foram positivas pela reaçäo de dupla-difusäo (DD) e 65,3% (115/176) pela reaçäo de contraimunoeletroforese (CIEOP). Esses resultados demonstraram a utilidade dos métodos para o estudo rotineiro do antígeno viral. A diferença na positividade dos métodos näo é estatisticamente significante (p> 0,1). Erro Padräo do Total. Sugerimos, portanto, que no método de DD pode ser usado em variadas condiçöes de laboratório por sua simplicidade e baixo custo operacional

Delecoes do DNA mitocondrial no envelhecimento: efeito da disfuncao na fosforilacao oxidativa / DNA, mitocondrial deletion in aging: disfunction effect in oxidative phosphorylation

Acredita-se que o acumulo de delecoes do DNA mitocondrial (DNAmt) no envelhecimento seja devido a lesao por radicais livres. Advoga-se que um ciclo vicioso estaria envolvido: lesao do DNAmt -> defeito na cadeia respiratoria -> producao de radicais livres -> lesao do DNAmt. Se este ciclo e um fator importante, pacientes com deficiencia da funcao oxidativa apresentariam um acumulo acelerado dessas delecoes. Testamos esta hipotese atraves de tres analises: (a) comparacao dos niveis de uma delecao especifica, delecao comum (DC), em controles normais e pacientes com mitocondriopatia por mutacao do DNAmt; (b) analise da co-segregacao da DC com uma mutacao de ponto patogenica do DNAmt; (c) deteccao de delecoes multiplas por PCR (polymerase chain reaction) longo em controles e pacientes com mitocondriopatias. Observamos uma correlacao positiva entre a idade e niveis de DC em controles e pacientes...