Cut-off values of immunological tests to identify patients at high risk of severe lupus nephritis

Cut-off values for anti-dsDNA, anti-nucleosome and anti-C1q antibodies tests and for complement-mediated hemolytic activity (CH50) were explored to identify patients with high risk of developing severe lupus nephritis (LN). Forty-one patients with confirmed systemic lupus erythematosus (SLE) were identified; their levels for the three antibodies and complement had been measured on a same serum sample. These patients were classified based on the presence of renal involvem ent; sixteen had active proliferative LN. With the cut-off values accepted in the laboratory for SLE diagnosis (anti-dsDNA > 100 UI/ml, anti-nucleosome > 50 U/ ml or CH50 < 190 UCH50%) no significant differences were found between patients with and without LN. Anti-C1q > 40 U/ml showed a statistically significant association with LN and had 80% of specificity. Cut-off values for LN identified by Receiver Operating Characteristic curves (ROC) were higher for anti-dsDNA (> 455 IU/ml) and anti-nucleosome (>107 U/ml), lower for CH50 (< 150 UCH50%) and, for anti-C1q (> 41 U/ml) coincided with the cut-off values accepted for SLE. Anti-C1q > 134 U/ml had a 92% of specificity, 56% of sensibility and was associated with a fifteen-fold increased risk of LN. The simultaneous presence of anti-nucleosome > 107 U/ml and anti-C1q > 134 U/ml was associated with a 27-fold higher probability for LN. According to these results, the cut-off values used to detect SLE activity could be inadequate to identify patients at high risk of severe LN.

Se exploraron valores de corte para los ensayos de anti-ADNdc, anti-nucleosoma, anti-C1q y complemento hemolítico total (CH50) capaces de identificar los casos con mayor riesgo de nefritis lúpica (NL) grave. Se seleccionaron 41 pacientes ≥ 16 años con lupus eritematoso sistémico (LES) confirmado que tenían titulados los niveles de los tres anticuerpos y CH50, en una misma muestra de suero. Fueron clasificados según presencia de compromiso renal; 16 presentaron formas proliferativas de NL activa. Con los valores de corte aceptados por el laboratorio para el diagnóstico de LES (anti-ADNdc > 100 UI/ml, anti-nucleosoma > 50 U/ml o un CH50 < 190 UCH50%) no se encontraron diferencias significativas entre casos con y sin NL. Un anti-C1q > 40 U/ml tuvo una especificidad del 80% y mostró una asociación estadísticamente significativa con NL. Al aplicar curvas Receiver Operating Characteristic (ROC) para NL, se identificaron valores de corte más altos para anti-ADNdc (> 455 IU/ml) y anti-nucleosoma (> 107 U/ml), más bajo para CH50 (< 150 UCH50%) y para el anti-C1q (> 41 U/ml) coincidió con el aceptado para diagnóstico de LES. Un anti-C1q > 134 U/ml presentó una sensibilidad del 56%, una especificidad del 92% y se asoció con quince veces más riesgo de NL. La presencia simultánea de anti-C1q > 134 U/ml y anti-nucleosoma > 107 U/ml se asoció 27 veces más riesgo de NL. De acuerdo a estos resultados los valores de corte empleados para actividad en pacientes con LES podrían resultar inadecuados para identificar pacientes con mayor riesgo de NL grave.

Are 30 minutes of rest between two incremental shuttle walking tests enough for cardiovascular variables and perceived exertion to return to baseline values?

Objective: To verify whether 30 minutes of rest between two incremental shuttle walking tests (ISWT) are enough for cardiovascular variables and perceived exertion to return to baseline values in healthy subjects in a broad age range. Method: The maximal exercise capacity of 334 apparently healthy subjects (age ≥18) was evaluated using the ISWT. The test was performed twice with 30 minutes of rest in between. Heart rate (HR), arterial blood pressure (ABP), dyspnea, and leg fatigue were evaluated before and after each test. Subjects were allocated to 6 groups according to their age: G1: 18-29 years; G2: 30-39 years; G3: 40-49 years; G4: 50-59 years; G5: 60-69 years and G6: ≥70 years. Results: All groups had a good performance in the ISWT (median >90% of the predicted distance). The initial HR (HRi) of the second ISWT was higher than the first ISWT in the total sample (p<0.0001), as well as in all groups (p<0.0001). No difference was observed in the behavior of ABP (systolic and diastolic) and dyspnea between the two tests, but this difference occurred for leg fatigue (greater before the second ISWT) in G1 (p<0.05). Most subjects (58%) performed better in the second test. Conclusion: 30 minutes of rest between two ISWTs are not enough for all cardiovascular variables and perceived exertion to return to baseline values. However, this period appears to be sufficient for blood pressure and performance to recover in most subjects. .

Leishmania, Babesia and Ehrlichia in urban pet dogs: co-infection or cross-reaction in serological methods?

INTRODUCTION: The present study was designed to assess the occurrence of co-infection or cross-reaction in the serological techniques used for detecting the anti-Leishmania spp., -Babesia canis vogeli and -Ehrlichia canis antibodies in urban dogs from an area endemic to these parasites. METHODS: The serum samples from dogs were tested for the Babesia canis vogeli strain Belo Horizonte antigen and Ehrlichia canis strain São Paulo by immunofluorescence antibody test (IFAT) and by anti-Leishmania immunoglobulin G (IgG) antibody detection to assess Leishmania infection. We used the following four commercial kits for canine visceral leishmaniasis: ELISA, IFAT, Dual Path Platform (DPP) (Bio Manguinhos(r)/FIOCRUZ/MS) and a rK39 RDT (Kalazar Detect Canine Rapid Test; Inbios). RESULTS : Of 96 serum samples submitted to serological assays, 4 (4.2%) were positive for Leishmania as determined by ELISA; 12 (12.5%), by IFAT; 14 (14.6%) by rK39 RDT; and 20 (20.8%), by DPP. Antibodies against Ehrlichia and Babesia were detected in 23/96 (23.9%) and 30/96 (31.2%) samples, respectively. No significant association was identified between the results of tests for detecting Babesia or Ehrlichia and those for detecting Leishmania (p-value>0.05). CONCLUSIONS: In the present study, we demonstrated co-infection with Ehrlichia or Babesia and Leishmania in dogs from Minas Gerais (Brazil); we also found that the serological tests that were used did not cross-react. .

Anticuerpos antinucleosoma frente a marcadores inmunológicos convencionales en el diagnóstico de la actividad del lupus eritematoso sistémico / Anti-nucleosome antibodies against conventional Immunological markers in the diagnosis of SLE activity

OBJETIVOS: examinar el perfil de anticuerpos en pacientes con lupus eritematoso sistémico y establecer la correlación entre los niveles de anticuerpos y la actividad de la enfermedad y de la nefritis lúpica. MÉTODOS: en 213 pacientes con lupus eritematoso sistémico, atendidos de forma consecutiva, se determinaron los anticuerpos anti-DNA de doble cadena (DNAdc), antinucleosoma (Nu), anti-Sm, anti-RNP, anti-Ro, anti-La y anti-Scl-70 por ensayo inmunoadsorbente ligado a enzima (ELISA), el C3 y el C4. La actividad de la enfermedad fue evaluada por el índice SLEDAI-2K, sin la contribución de anti-DNAdc, C3 ni C4. Los niveles de anticuerpos, el complemento y la actividad del lupus eritematoso sistémico fueron correlacionados. RESULTADOS: los niveles de todos los anticuerpos resultaron superiores significativamente en los pacientes en fase activa de la enfermedad con respecto a los que se hallaban en la fase inactiva. Los coeficientes de correlación de Spearman más altos con la puntuación de SLEDAI-2K correspondieron a los anti-Nu y anti-DNAdc (p= 0,856 y p= 0,616, respectivamente, p < 0,001 para ambos). Las áreas bajo de la curva (AUC) del análisis COR de la actividad del LES fueron en orden decreciente para los anti-Nu= 0,948, anti-DNAdc= 0,810, anti-RNP= 0,705, C4= 0,704, anti-Sm= 0,703, C3= 0,688, anti-Scl-70= 0,611, anti-La= 0,601 y anti-Ro= 0,593; y de la actividad renal para los anti-Nu= 0,845, anti-DNAdc= 0,755, C4= 0,694, C3= 0,670, anti-Sm= 0,641, anti-RNP= 0,630, anti-Scl-70= 0,611, anti-Ro= 0,593 y anti-La= 0,567. CONCLUSIÓN: los anticuerpos anti-Nu mostraron una capacidad discriminatoria excelente para la actividad del LES y de la actividad renal lúpica, superior a la de los anti-DNAdc y el resto de los marcadores.

OBJECTIVES: to examine the profile of antibodies in patients with systemic lupus erythematosus and establish the correlation between antibody levels and disease activity, and lupus nephritis. METHODS: anti-double stranded DNA (dsDNA), antinucleosoma (Nu), anti-Sm, anti-RNP, anti-Ro, anti-La, and anti-Scl-70 antibodies by enzyme-linked immunosorbent assay (ELISA) as well as C3 and C4 were determined in 213 patients with systemic lupus erythematosus who were treated consecutively. Disease activity was assessed by the SLEDAI 2K-index, without the contribution of anti-dsDNA, C3 or C4. The levels of antibodies, complement and activity of systemic lupus erythematosus were correlated. RESULTS: the levels of antibodies turned out to be remarkably higher in patients in the active phase of the disease compared to those who were in the inactive phase. The higher Spearman correlation coefficients with SLEDAI-2K score corresponded to the anti-Nu and anti-dsDNA (p = 0.856 and p = 0.616, respectively, p <0.001 for both). The areas under the ROC curve analysis of the activity of systemic lupus erythematosus were in descending order as follows: anti-Nu = 0.948; anti-dsDNA = 0.810; anti-RNP = 0.705; C4 = 0.704; anti-Sm = 0.703; C3 = 0.688; anti-Scl-70 = 0.611; = 0.601 anti-La. Anti-Ro = 0.593; and renal activity for anti-Nu = 0.845; anti-dsDNA = 0.755; C4= 0.694; C3 = 0.670; anti-Sm = 0.641; anti-RNP = 0.630; anti-Scl-70 = 0.611; anti-Ro = 0.593 and anti-La = 0.567. CONCLUSION: the anti-Un exhibit excellent activity discriminating capacity of SLE lupus and renal activity, higher than the anti-dsDNA and other markers.

El papel de los anticuerpos anti-cromatina, antiC1qy las fracciones del complemento unidas a célulasen el diagnóstico precoz de actividad lúpica / Role of Anti-chromatin, anti-C1q and cell bound complement activation products in the early diagnosis of Systemic Lupus Erythematosus disease activity

Actualmente se percibe una necesidad apremiante en la identificación y validación debiomarcadores que reflejen tempranamente el inicio de actividad lúpica o que se conviertanen predictores de la misma. La actividad clínica del lupus eritematoso sistémico (LES) esondulante a lo largo del tiempo y la actividad subyacente persistente lleva a daño tisular.Este daño es reflejo de cambios irreversibles en la función y estructura orgánica, por loque la prevención, más que el tratamiento, debería ser la meta de cualquier terapia enLES y así lograr disminuir la morbimortalidad y los costos directos e indirectos causadospor la enfermedad. Es necesario encontrar biomarcadores no invasivos de actividadlúpica que no solo permitan tomar de forma oportuna decisiones terapéuticas, sino quetambién se correlacionen con los desenlaces clínicos y sean útiles en los ensayos clínicos,permitiendo acortar el tiempo del desarrollo de estos estudios. Este artículo pretendebuscar la evidencia que se tiene con respecto a los nuevos biomarcadores existentes paraactividad de la enfermedad en LES y su utilidad actual y futura, enfatizando en la necesidadde buscar nuevas moléculas que permitan un diagnóstico más precoz de la actividad de laenfermedad.

There is a need for the identification and validation of biomarkers that reflect the early onset of lupus activity or may be predictors of this. The clinical activity of systemic lupus erythematosus (SLE) fluctuates over time and the underlying activity leads to persistent tissue damage. This damage is a reflection of irreversible changes in the function and organic structure, so prevention, rather than treatment, should be the goal of any therapy in SLE.This will reduce morbidity, mortality, direct and indirect costs caused by the disease. It is necessary to find biomarkers of lupus activity that not only allow making treatment decisions in the short term, but also to correlate with clinical outcomes. These could also be useful in clinical trials and may shorten the duration of these studies. This article aims to find evidence on new biomarkers for SLE disease activity, and their current and future use. Emphasis will be made on the need to find new molecules for an early diagnosis of disease activity.

Influencia de las modificaciones epigenéticasocasionadas por el consumo de cigarrillos en relación con la disminución del hueso alveolar-revisión de la literatura / Epigenetic influence of changes caused by cigarette consumption in relation to the bone reduction alveolar-literature review

La epigenética hoy en día constituye uno de los temas de mayor interés en el campo científico, debido a la relación que se ha encontrado con cambios fenotípicos, siendo la metilación del ADN y la desacetilación de las histonas los principales eventos que la caracterizan. A su vez, se ha evidenciado en una amplia gama de patologías. Es por esto, que los factores que inducen estos cambios epigenéticos pueden ser ambientales (como el cigarrillo) o hereditarios. Hay que destacar que entre las alteraciones en las que se ha visto involucrada a la epigenética se encuentra disminución en la cantidad y calidad del hueso en el complejo maxilar-mandíbula, los cuales, a su vez son considerados parámetros de vital importancia en tratamientos odontológicos rehabilitadores. El objetivo de la presente investigación realizar una revisión a la literatura actualizada con el propósito de describir la influencia de las modificaciones epigenéticas ocasionadas por el consumo de cigarrillos y su asociación con la resorción ósea alveolar.

In the present time, the epigenetics is one of the topics with most interest on the scientific field, due to the relationship that has been found with phenotypic changes, been epigenetic´s main event the DNA methylation and the Histone acetylation, that at the same time have been evidenced on a great quantity of pathologies. Because of this, the epigenetics changes are induced by environmental (like smoking) and hereditary factors. Is worth to mention, that among the alterations on which the epigenetic has been related is found the decrease en the quality and quantity of the bone on the maxillary-mandibular complex, which are also consider important parameters for successful dental rehabilitators treatments. A current bibliographic revision was made with the purpose of describe the influence of epigenetic´s modifications involved on the smoking in relationships with the of the alveolar bone loss.

Anticorpos antinucleossomo e síndrome antifosfolipídica: estudo observacional / Antinucleosome antibodies and primary antiphospholipid syndrome: an observational study

OBJETIVO: Avaliar a associação entre a presença de anticorpos antinucleossomo (anti-NCS) e a síndrome antifosfolipídica primária (SAFP) e o posterior desenvolvimento de lúpus eritematoso sistêmico (LES). MATERIAIS E MÉTODOS: Trinta e seis mulheres com o diagnóstico de SAFP foram avaliadas prospectivamente para manifestações de doenças reumáticas autoimunes e para a presença de anticorpos antifosfolípides, anticorpos antinucleares e anti-NCS/cromatina. RESULTADOS: Após um período médio de seguimento de 45,7 meses, anticorpos anti-NCS/cromatina foram detectados em apenas uma paciente (2,8%), que desenvolveu manifestações de LES tais como poliartrite, linfopenia, neurite óptica, lesões compatíveis com esclerose múltipla em substância branca cerebral e perfil de autoanticorpos altamente sugestivo de LES. CONCLUSÃO: A frequência de anticorpos anti-NCS/cromatina é baixa em pacientes com SAFP, e sua presença pode associar-se ao desenvolvimento de manifestações de LES.

OBJECTIVE: To study the association of anti-nucleosome (anti-NCS) antibodies in primary antiphospholipid syndrome (APS) and the development of systemic lupus erythematosus (SLE) during follow-up. MATERIALS AND METHODS: Thirty-six women with primary APS were evaluated prospectively for clinical features of systemic autoimmune diseases and for the presence of antiphospholipid antibodies, antinuclear antibodies and anti-NCS/chromatin antibodies. RESULTS: After a mean follow-up period of 45.7 months, anti-NCS/chromatin antibodies were detected in only one patient (2.8%), who developed features of SLE including polyarthritis, lymphopenia, optic neuritis, multiple sclerosis-like lesions, and an autoantibody profile suggestive of SLE. CONCLUSION: The frequency of anti-NCS/chromatin antibodies in primary APS patients is very low, and they may be associated with the development of SLE manifestations.

Expression of HMGB1 and HMGN2 in gingival tissues, GCF and PICF of periodontitis patients and peri-implantitis

High mobility group chromosomal protein B1 (HMGB1) and N2 (HMGN2), two members of High mobility group (HMG) family, play important role in inflammation. The purposes of this study were to investigate the expression of HMGB1 and HMGN2 in periodontistis. The expression of HMGB1 and HMGN2 mRNA in gingival tissues and gingival crevicular fluid (GCF) in chronic periodontitis (CP), generalized aggressive periodontitis (G-AgP) patients and healthy subjects was detected by real-time PCR. The protein level of HMGB1 and HMGN2 in peri-implant crevicular fluid (PICF), peri-implant crevicular fluid of peri-implantitis (PI-PICF) and normal patients was determined by Western blotting. Furthermore, IL-1â, IL-6, IL-8, TNF-á and HMGB1 levels in GCF, PI-PICF and healthy-PICF samples from different groups were determined by ELISA. HMGN2 expression was increased in inflamed gingival tissues and GCF from CP and G-ApG groups compared to control group. HMGB1 expression was the highest in the gingival tissues and GCF from CP patients and was accompanied by increased concentrations of IL-1â, IL-6, IL-8 proinflammaory cytokines. To our knowledge, this is the first study reporting that the expression of HMGB1 and HMGN2 was increased in the gingival tissues and GCF in CP and G-AgP and the PICF in PICF. Our data suggest that HMGB1 may be a potential target for the therapy of periodontitis and PI.

Apoptosis in pulp elimination during physiological root resorption in human primary teeth

Pulp samples of 50 healthy human teeth with indication for extraction were examined to evaluate the role of apoptosis in pulp elimination during physiological root resorption. Two groups were formed: a test group (n=30) composed of pulp samples of primary teeth with physiological root resorption and a control group (n=20) composed of pulp samples of permanent maxillary third molars. Morphological evidence of apoptosis as well as in situ detection of cellular DNA fragmentation by TUNEL assay and detection of internucleosomal pattern of fragmentation of the genomic DNA by electrophoresis were observed. The apoptotic index of the primary tooth group was significantly higher than that of the permanent tooth group (51.01 ± 0.52 versus 25.32 ± 0.68) (p<0.001). TUNEL reaction showed intense and diffuse labeling in the pulp samples of primary teeth, which were discrete in the controls. Intense DNA internucleosomal fragmentation, a specific pattern for apoptosis, was observed in primary tooth pulps DNA by electrophoresis, in the permanent tooth pulps this pattern fragmentation of the genomic DNA for apoptosis were not present. These results seem to indicate a role of apoptosis in pulp elimination during the physiological root resorption of human primary teeth.

Cinqüenta amostras de polpas de dentes humanos hígidos com indicação para extração foram estudadas a fim de verificar a participação da apoptose na eliminação pulpar durante a reabsorção radicular fisiológica. As amostras foram divididas em 2 grupos: um grupo de estudo composto por 30 polpas de dentes decíduos hígidos com reabsorção radicular fisiológica, e um grupo controle composto por 20 polpas de terceiros molares superiores hígidos. Evidências morfológicas de apoptose, bem como detecção in situ da fragmentação do DNA genômico via reação de TUNEL e também a detecção do padrão internucleossômico de fragmentação do DNA genômico via eletroforese foram observados. O índice apoptótico foi maior no grupo de dentes decíduos (51,01 ± 0,52) quando comparado ao grupo de dentes permanentes (25,32 ± 0,68) (p<0,001). Quanto à reação de TUNEL, houve intensa marcação positiva para fragmentação do genoma no grupo de estudo, o que ocorreu de maneira discreta nos controle. A eletroforese do DNA genômico mostrou fragmentação internucleossômica, em um padrão específico de apoptose nas amostras de dentes decíduos o que não ocorreu no grupo de dentes permanentes. Estes achados parecem indicar a apoptose como um mecanismo importante na eliminação do tecido pulpar durante a reabsorção radicular fisiológica de dentes decíduos humanos.

Pesquisa de anticorpos antinucleossoma em lúpus eritematoso sistêmico / Detection of antinucleosome antibodies in systemic lupus erythematosus

OBJETIVOS: determinar a freqüência dos anticorpos antinucleossoma (AN) em lúpus eritematoso sistêmico (LES) e avaliar a associação desses anticorpos com a atividade de doença. MÉTODOS: estudo de corte transversal em que foram estudados pacientes com diagnóstico de LES baseado nos critérios do Colégio Americano de Reumatologia. Utilizou-se o SLEDAI como instrumento de avaliação de atividade de doença. A pesquisa de anticorpos AN foi realizada pela técnica de ELISA (INOVA Diagnostics Inc). Pacientes com diagnóstico de miosite e esclerose sistêmica (ES) foram também estudados para avaliação da performance do teste. RESULTADOS: foram estudados 82 pacientes com LES, sendo 81 do sexo feminino, com idade média de 35 ± 11,7 anos. Anticorpos AN foram detectados em 48 pacientes com LES (58,5 por cento), em três pacientes com miosite (21,4 por cento) e em dois pacientes com ES (14,2 por cento), o que determinou sensibilidade e especificidade de 58,5 por cento e 82,14 por cento, respectivamente. Considerando-se um ponto de corte em 40 U, os anticorpos AN foram detectados em 44 pacientes com LES (53,65 por cento), em dois pacientes com miosite (13,33 por cento) e em um paciente com ES (6,66 por cento), o que determinou sensibilidade e especificidade de 53,65 por cento e 90 por cento, respectivamente. Não se observou correlação dos títulos dos anticorpos AN e a atividade de doença (SLEDAI), embora tenha sido observada correlação entre anti-DNA e escore de SLEDAI nessa mesma população (r = 0,42; p < 0,005). CONCLUSÕES: No presente estudo, observaram-se moderada sensibilidade e alta especificidade dos anticorpos AN para o diagnóstico de LES. No entanto, não se verificou associação desses anticorpos com os parâmetros de atividade da doença, sugerindo que a pesquisa de tais anticorpos seria de valor limitado na prática reumatológica.

OBJECTIVE: to determine the frequency of antinucleosome (AN) antibodies in systemic lupus erythematosus (SLE) and their association with disease activity. METHODS: cross-sectional study to evaluate patients with diagnosis of SLE based on the American College of Rheumatology criteria. SLEDAI score was used as a disease activity index. AN antibodies were tested by ELISA (INOVA Diagnostics Inc). Systemic sclerosis (SSc) and myositis patients were also studied to determine the diagnostic performance of the ELISA system. RESULTS: a total of 82 SLE patients, 81 female, mean age 35 ± 11.7 years were included in the study. AN antibodies were positive in 48 SLE samples (58.5 percent), three with myositis (21.4 percent) and two with SSc (14.2 percent), determining a sensitivity and specificity of AN antibodies for the diagnosis of SLE of 58.5 percent and 82.14 percent, respectively. Utilizing a cut off of 40 U, test was positive in 45 SLE samples (53.65 percent), two with myositis (13.33 percent) and one with SSc (6.66 percent), determining a sensitivity and specificity of AN antibodies for the diagnosis of SLE of 53.65 percent and 90 percent, respectively. There were no correlation between AN antibodies and SLEDAI scores. On the other hand, it was observed a positive correlation between anti-DNA antibodies and disease activity (r = 0.42; p < 0.005). CONCLUSIONS: in the present study it was demonstrated a high specificity and moderate sensitivity of AN antibodies for the diagnosis of SLE. However, the lack of association with disease activity suggests that it has limited value in rheumatologic practice.

Detecção de anticorpos antinucleossomos em soros com diferentes padrões de imunofluorescência em células HEp2 / Detection of antinucleosome antibodies in sera with different patterns of immunofluorecence in HEp 2 cells

Objetivo: Este trabalho tem como objetivo a detecçãode anticorpos antinucleossomos em soros positivoscom diferentes padrões de fluorescência para anticorposantinucleares. Métodos: Até recentemente, não se dispunha de metodologia para a detecção destes anticorpos. Atravésda técnica de imunofl uorescência indireta (IFI) emcélulas HEp2 para a análise de fatores antinucleares(FAN) e ensaios de ELISA (ORGENTEC diagnostika GmbH, Mainz, Alemanha) para detecção de ANucls, realizou-se pesquisa em 61 soros obtidos na rotina de laboratório clínico. A detecção de anticorpos anti-DNAn foi realizado por IFI no tripanossomo Crithidia luciliae (DTS, Randburg, R.S.A) e anti-ENA por ELISA (Hemagen, São Paulo, Brasil). Resultados: Do total de soros pesquisados, 80,3 foram positivos e 19,7 negativos para o FAN, com diferentes padrões de fluorescência. Todos os FANs negativos não apresentaram ANucls. Das amostras positivas, 57 foram também positivas para ANucls. Com relação aos padrões de fluorescência o padrão homogêneo mostrou 91,6 de positividade, pontilhado grosso 91, pontilhado fi no denso 50, centromérico e nucleolar 0. A concomitância de ANucls e anti-DNAn ocorreu em 8 e anti-ENA com ANucls em 28,5. Conclusão: Pôde-se concluir que ANucls detectados em 57 dos casos de FAN positivo ocorreram de forma isolada ou concomitante com outros auto anticorpos antinucleares (DNAn e ENA). Finalmente, este trabalho demonstra que o conceito prático de que ANucls ocorre apenas com padrão homogêneo não corresponde à realidade

Anticorpos antinucleossomo em pacientes com lúpus eritematoso sistêmico juvenil / Antinucleosome antibodies in patients with juvenile systemic lupus erythematosus

Este estudo teve por objetivos avaliar a positividade do anticorpo antinucleossomo (anti-Ncs) no LES juvenil, sua associação com manifestações e atividade da doença e compará-lo ao anticorpo anti-DNA. A pesquisa dos anticorpos anti-Ncs e anti-DNA foi realizada em 74 pacientes com LESJ e 64 controles. Os anti-Ncs e anti-DNA demonstraram sensibilidade / The aims of this study were to evaluate the positivity of antinucleosome antibodies (Anti-Ncs) in SLE children, their association to disease manifestations and activity, and to compare them to anti-DNA antibodies. Anti-Ncs and anti-DNA were tested on 74 JSLE patients and 64 controls...

Análisis molecular del proceso de transcripción de genes en eucariontes / Molecular analysis of genome transcription in eukaryotes

El proceso de transcripción es altamente regulado en el que intervienen la RNA polimerasa y varios factores adicionales. La enzima RNA polimerasa II contiene entre 8 y 14 subunidades y es la enzima que transcribe los RNA que codifican para proteínas. La subunidad mayor de la RNA polimerasa II contiene en su región carboxilo terminal un dominio denominado CTD que consiste en repeticiones de un heptapépido, el cual es fundamental para la regulación de la transcripción. El proceso de transcripción consiste de tres etapas, iniciación, elongación y terminación. A pesar que la RNA polimerasa II es una enzima multimérica, no puede reconocer los promotores e iniciar la transcripción en forma específica. Para iniciar la transcripción en forma específica requiere de factores adicionales, denominados factores generales de transcripción, los cuales se denominan TFIIA, TFIIB, TFIID, TFIIE, TFIIF y TFIIH. Estos factores y la RNA polimerasa II se ensamblan sobre el promotor en forma secuencial, o preensamblados con la RNA polimerasa II. Los genes son activados en respuesta a señales fisiológicas, llevada a cabo por los activadores de la transcripción, los que se unen a secuencias intensificadoras que están ubicadas río arriba del sitio de iniciación. Para la activación de la transcripción, además de los activadores, se requiere de un complejo MED, el cual puede encontrarse libre o bien unido al CTD de la RNA polimerasa II. El DNA se encuentra compactado dentro del núcleo por historias, las cuales presentan un impedimento físico para que se forme un complejo de iniciación sobre el promotor. Existen enzimas que poseen la capacidad de modificar las historias, que se denominan acetilasas, las cuales acetilan el dominio aminoterminal de las historias, provocando una inestabilidad en el nucleosoma, lo cual permite que se forme un complejo de preiniciación de la transcripción. También existen factores que son capaces de desplazr los nucleosomas para permitir la unión de la RNA polimerasa II y sus factores al promotor

Nematosomes or nucleolus-like bodies in the pineal gland of the opussum: diurnal rhythmicity

A morfologia dos corpos citoplasmáticos grânulo-filamentosos conhecidos como nematosomas, ou corpos semelhantes a nucléolos foi estudada ao microscópico eletrônico em pinealócitos do gambá (Didelphis albiventris, Lund). Foram feitas também contagens destas estruturas en pineais de animais sacrificados em diferentes tempos ao longo de um período de 24 horas (claro/escuro = 12/12) com o objetivo de se verificar a existência de ritmicidade. As contagens näo mostraram diferença significativa entre o número de nematosomas obtido as 15 e as 3 horas, mas houve um aumento significativo de duas vyezes entre 3 e 9 horas, caracterizando a existência de um ritmo de 24 horas com um pico no início do período de luz. Este resultado indica que os nematosomas dos pinealócitos do gambá säo estruturas dinâmicas, tendo sido sugerido que eles poderiam funcionar como armazenadores ciclicos de substâncias que seriam liberadas periodicamente na matriz citoplasmática para atender requisitos metabólicos rítmicos dos pinealócitos

Mg2+ - dependent ATPase activity investigated in heterochromatin, euchromatin and nucleoli of Triatoma infestans

Foram demonstradas ATPases dependentes de Mg2+ com procedimentos citoenzimatológicos, a nível da microscopia de luz na eucromatina e nucléolo, mas näo na heterocromatina de núcleos poliplóides de ninfas, durante o desenvolvimento de Triatoma infestans. A nível da microscopia eletrônica, a eucromatina näo exibe o produto da reaçäo, um achado que é atribuído a ligeiras diferenças na metodologia quando comparado com aqueles da microscopia luz. Presume-se que as ATPases detectadas na eucromatina estejam relacionadas com as atividades de transcriçäo

Aspects of active chromatin in chromosomes displaying loops/scaffold configuration: high-resolution autoradiography

Cromossomos profásicos apresentando a configuraçäo "loops/scaffold" foram obtidos em espalhamentos de células do sangue periférico humano de indivíduos normais e afetados. Observou-se uma distinta classe de alças condensadas formando um corpo cromatínico de diâmetro variável. Essas alças säo intensamente dobradas, têm nucleossomos alterados, apresentam fibrilas laterais e fragmentam-se formando anéis. Estas fibrilas incorporam 5 3H uridina, como demonstrado por autoradiografia de alta resoluçäo. As alteraçöes dos nucleossomos foram explicadas pela remoçäo de histonas sendo os anéis indicativos de seqüências repetitivas do DNA