Examen clínico y maniobra de valsalva en la insuficiencia cardíaca / Clinical examination and the Valsalva maneuver in heart failure

La evaluación de la congestión en pacientes con insuficiencia cardíaca y fracción de eyección reducida (ICFEr) resulta relevante y estrechamente vinculada al curso clínico. El agregado del comportamiento de la presión arterial durante la maniobra de Valsalva en la cabecera del paciente (VAL) podría mejorar la evaluación clínica de congestión cuando la comparamos con los niveles de NT-proBNP y la estimación de la presión media en la aurícula izquierda por Doppler cardíaco, como subrogantes de congestión. Se realizó un examen clínico con el VAL, un examen de laboratorio y un Doppler cardíaco en 69 pacientes ambulatorios con insuficiencia cardíaca y fracción de eyección ≤ 40% en ritmo sinusal. El score de Framingham ≥ 2 (SFr ≥ 2) se empleó para evaluar congestión clínica. VAL fue clasificado como normal o anormal, el NT-proBNP como bajo (< 1000 pg/ml) o alto (≥ 1000 pg/ml) y la relación entre la velocidad del llenado ventricular rápido y la velocidad del Doppler tisular (E/e') como baja < 15 o alta ≥ 15. Se halló que 13/27 pacientes con SFr ≥ 2 tenían NT-proBNP alto (sensibilidad 62%, especificidad 70% y razón de verosimilitud positiva [LR+] de 2.08, p = 0.01). El agregado del VAL al SFr ≥ 2 mejoró la exactitud diagnóstica (sensibilidad 100%, especificidad 64% y LR+ 2.8 p = 0.0004). Comparado con la E/e', SFr ≥ 2 con VAL anormal mostró sensibilidad 86%, especificidad 56% y LR + 1.86 (p = 0.03). En conclusión, el agregado del comportamiento de la presión durante la maniobra de Valsalva podría mejorar la evaluación clínica de la congestión en la insuficiencia cardíaca.

Congestion in heart failure patients with reduced ejection fraction (HFrEF) is relevant and closely linked to the clinical course. Bedside blood pressure measurement during the Valsalva maneuver (Val) added to clinical examination may improve the assessment of congestion when compared to NT-proBNP levels and left atrial pressure (LAP) estimation by Doppler echocardiography, as surrogate markers of congestion in HFrEF. A clinical examination, LAP and blood tests were performed in 69 HFrEF ambulatory patients with left ventricular ejection fraction ≤ 40% and sinus rhythm. Framingham Heart Failure Score (HFS) was used to evaluate clinical congestion; Val was classified as normal or abnormal, NT-proBNP was classified as low (< 1000 pg/ml) or high (≥ 1000 pg/ml) and the ratio between Doppler early mitral inflow and tissue diastolic velocity was used to estimate LAP and was classified as low (E/e'< 15) or high (E/e' ≥ 15). A total of 69 patients with HFrEF were included; 27 had a HFS ≥ 2 and 13 of them had high NT-proBNP. HFS ≥ 2 had a 62% sensitivity, 70% specificity and a positive likelihood ratio of 2.08 (p=0.01) to detect congestion. When Val was added to clinical examination, the presence of a HFS ≥ 2 and abnormal Val showed a 100% sensitivity, 64% specificity and a positive likelihood ratio of 2.8 (p = 0.0004). Compared with LAP, the presence of HFS ≥ 2 and abnormal Val had 86% sensitivity, 54% specificity and a positive likelihood ratio of 1.86 (p = 0.03). In conclusion, an integrated clinical examination with the addition Valsalva maneuver may improve the assessment of congestion in patients with HFrEF.

Effects and Mechanisms of Radiofrequency Ablation of Renal Sympathetic Nerve on Anti-Hypertension in Canine / Efeitos e Mecanismos da Denervação Simpática Renal por Radiofrequência na Anti-Hipertensão em Cães

Abstract Background: Radiofrequency ablation of renal sympathetic nerve (RDN) shows effective BP reduction in hypertensive patients while the specific mechanisms remain unclear. Objective: We hypothesized that abnormal levels of norepinephrine (NE) and changes in NE-related enzymes and angiotensinconverting enzyme 2 (ACE2), angiotensin (Ang)-(1-7) and Mas receptor mediate the anti-hypertensive effects of RDN. Methods: Mean values of systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) were assessed at baseline and follow-up. Plasma and renal norepinephrine (NE) concentrations were determined using highperformance liquid chromatography with electrochemical detection, and levels of NE-related enzyme and ACE2-Ang(1-7)- Mas were measured using real time PCR, Western blot and immunohistochemistry or Elisa in a hypertensive canine model fed with high-fat diet and treated with RDN. The parameters were also determined in a sham group treated with renal arteriography and a control group fed with normal diet. Results: RDN decreased SBP, DBP, MAP, plasma and renal NE. Compared with the sham group, renal tyrosine hydroxylase (TH) expression was lower and renalase expression was higher in the RDN group. Compared with the control group, renal TH and catechol-o-methyl transferase (COMT) were higher and renalase was lower in the sham group. Moreover, renal ACE2, Ang-(1-7) and Mas levels of the RDN group were higher than those of the sham group, which were lower than those of the control group. Conclusion: RDN shows anti-hypertensive effect with reduced NE and activation of ACE2-Ang(1-7)-Mas, indicating that it may contribute to the anti-hypertensive effect of RDN.

Resumo Fundamentos: A denervação simpática renal por radiofrequência (DSR) mostra redução eficaz da pressão arterial (PA) de pacientes hipertensos, ainda que os mecanismos específicos permaneçam obscuros. Objetivo: Fizemos a hipótese de que níveis alterados de noradrenalina (NA) e mudanças nas enzimas relacionadas à NA e enzima conversora de angiotensina 2 (ECA-2), angiotensina (Ang)-(1-7) e receptor Mas são mediadores dos efeitos antihipertensivos da DSR. Métodos: Foram avaliados os valores médios de pressão arterial sistólica (PAS), pressão arterial diastólica (PAD) e pressão arterial média (PAM) no início e durante o seguimento. Foram medidas as concentrações plasmática e renal de noradrenalina (NA) por cromatografia líquida de alta eficiência com detecção eletroquímica, e os níveis de enzima relacionada à NA e ECA2-Ang-(1-7)-Mas através de PCR em tempo real, Western blot e imunohistoquímica ou Elisa em um modelo canino de hipertensão que recebeu ração rica em gordura e foi tratado com DSR. Os parâmetros também foram determinados em um grupo de cirurgia simulada submetido à arteriografia renal e em um grupo controle que recebeu dieta normal. Resultados: DSR causou diminuição da PAS, PAD, PAM e das concentrações plasmática e renal de NA. Em comparação ao grupo placebo, a expressão da tirosina hidroxilase (TH) renal foi menor e a da renalase foi maior no grupo DSR. Em comparação ao grupo controle, os níveis de TH renal e de catecol-o-metil-transferase (COMT) foram maiores e os de renalase foram menores no grupo cirurgia simulada. Além disso, os níveis renais de ECA2, Ang-(1-7) e Mas foram maiores no grupo DSR do que no grupo cirurgia simulada, que, por sua vez, foram menores do que no grupo controle. Conclusões: A DSR mostra efeitos anti-hipertensivos com redução da NA e ativação da ECA2-Ang-(1-7)-Mas, o que indica que pode contribuir com o efeito anti-hipertensivo da DSR.

Producción y evaluación del antígeno recombinante TES-30 de Toxocara canis para el inmunodiagnóstico de toxocariasis / Production and evaluation of the recombinant antigen TES-30 of Toxocara canis for the immunodiagnosis of toxocariasis

Introducción. Toxocara canis es un nematodo patógeno de cánidos que accidentalmente puede ser transmitido a los humanos. A pesar de la importancia de la serología para el diagnóstico de esta zoonosis, los kits diagnósticos usan antígenos crudos de excreción-secreción, en su mayoría glucoproteínas que no son específicas de especie, por lo cual pueden presentarse reacciones cruzadas con anticuerpos generados contra otros parásitos. Objetivos. Producir el antígeno recombinante TES-30 de T. canis y evaluarlo para el inmunodiagnóstico de la toxocariasis. Materiales y métodos. Se clonó el gen que codifica TES-30 en el vector de expresión pET28a (+), usando oligonucleótidos de cadena sencilla unidos mediante reacción en cadena de la polimerasa (PCR). La proteína rTES-30 se purificó por cromotografia de afinidad (Ni 2+ ). La reacción serológica de rTES-30 se evaluó mediante immunoblot . Teniendo en cuenta que no existe una prueba de referencia , se observó el comportamiento del antigeno en comparación con la prueba de rutina para el inmunodiagnóstico de la toxocariasis, es decir, la técnica ELISA convencional con antígenos de excreción-secreción. Resultados. El rTES-30 se produjo a partir de un cultivo de Escherichia coli LB, con un rendimiento de 2,25 mg/l y 95 % de pureza. La concordancia de la reacción entre el immunoblot rTES-30 y la ELISA convencional, fue de 73 % (46/63) y de 100 % con los 21 sueros no reactivos. De los 21 sueros con diagnóstico de otras parasitosis, 19 fueron reactivos con ELISA, mientras que tan solo siete fueron positivos con el immunoblot rTES-30. La concordancia entre la ELISA y el immunoblot fue moderada (índice kappa de 0,575; IC 95% 0,41-0,74). Conclusiones. Los datos presentados respaldan la utilidad del immunoblot r TES-3 0 para la confirmación de los posibles positivos por ELISA, no solo en los estudios epidemiológicos, sino también, como candidato para el desarrollo de pruebas diagnósticas de la toxocariasis ocular en Colombia.

Introduction: Toxocara canis is a pathogenic nematode of canines which can be accidentally transmitted to humans. Although serology is the most important diagnostic tool for this zoonosis, diagnostic kits use crude excretion/secretion antigens, most of them being glycoproteins which are not species-specific and may cross-react with antibodies generated against other parasites. Objectives: To produce the rTES-30 recombinant antigen of Toxocara canis and evaluate it in the immunodiagnosis of toxocariasis. Materials and methods: The gene that codes for TES-30 was cloned in the expression vector pET28a (+) using single-stranded oligonucleotides united by PCR. The protein rTES-30 was purified by Ni 2+ affinity chromotography. Seroreactivity of rTES-30 was evaluated by immunoblot. Given that there is no gold standard test, the behaviour of the antigen was compared with the method that is routinely used to immunodiagnose toxocariasis, i.e., the conventional ELISA technique using excretion/secretion antigens. Results: The rTES-30 was produced from an Escherichia coli LB culture which yielded 2.25 mg/L of the antigen with a purity of 95%. The results obtained showed 73% (46/63) concordance of reactivity between the rTES-30 immunoblot and the conventional ELISA, and 100% concordance with the non-reactive sera (21). Nineteen of the 21 sera positive for other parasitoses reacted with ELISA, while only seven of these were positive with the rTES-30 immunoblot. Concordance between the ELISA and the immunoblot was moderate (kappa coefficient: 0.575; 95% CI: 0.41- 0.74). Conclusions: The data presented show the potential of the rTES-30 inmunoblot for confirmation of possible ELISA positives, not only in epidemiological studies, but also as a candidate for the development of diagnostic tests for ocular toxocariasis in Colombia.

Avaliação dos eixos ECA / ANG II / AT1 e ECA-2 / ANG (1-7) / MAS em fibroblastos de gengiva e ligamento periodontal humanos estimulados por IL-1ß e sua contribuição na produção e regulação de citocinas e quimiocinas / Evaluation ACE /ANG II /AT1 and ACE-2 /ANG (1-7) /MAS axis in gingival and periodontal ligament human fibroblasts stimulated with IL-1ß and its contribution in the production of cytokines and chemokines

O Sistema renina-angiotensina (SRA) tem sido relatado como um importante modulador de processos inflamatórios e imunológicos, incluindo a doença periodontal (DP). Estudos sugerem neste sistema um eixo alternativo (ECA-2 /ANG(1-7) /MAS) que atuaria como um contra-regulador de efeitos mediados pelo clássico eixo (ECA /ANGII /AT1). Sabe-se que bactérias periodontopatogênicas, como a Porphyromonas gingivalis (Pg), possuem componentes bioativos de membrana (ex. lipopolissacarídeos-LPS) capazes de induzir uma forte resposta imune no hospedeiro devido à liberação de citocinas nas células, entre elas Interleucina (IL)- 1ß. Neste contexto, fibroblastos são as células mais abundantes nos tecidos periodontais e possuem em sua superfície celular receptores necessários para o reconhecimento da invasão bacteriana, ativando cascatas intracelulares, que levam à produção de citocinas. O objetivo deste estudo foi verificar se os eixos ECA/ ANGII/ AT1 e ECA-2/ ANG(1-7)/ MAS contribuem para a produção e/ ou regulação de citocinas inflamatórias (CI) por fibroblastos de gengiva humana (HGF) e ligamento periodontal humano (HPLF) estimulados por IL-1ß. Após o pré-tratamento com Losartan e Ang (1-7) ou silenciamento mediado por RNA de interferência (RNAi) de AT1, HGF e HPLF foram estimulados por IL-1ß por 3 horas (RNAm) ou 24 horas (proteína). Expressão de RNAm para AT1, MAS, ECA, ECA-2, IL-1ß, TNF-α, IL-6, IL-8, IL-10, TGF-ß, CXCL12, RANK-L e OPG foram avaliados por RT-qPCR e das proteínas IL-6, IL-8, ECA e ECA-2 por ELISA. Foi realizado também Western Blot para detecção de AT1 e ECA nos extratos celulares e dosagem de nitrito no sobrenadante das culturas. Ambos os subtipos de fibroblastos mostraram aumento da expressão de RNAm para AT1, IL-1ß, IL-6, IL-8, TNF-α e OPG, quando estimulados por IL-1ß. No entanto, apenas em HPLF foi observado aumento para MAS, ECA e TGF-ß. Losartan e Ang (1-7) não modularam o transcrito, a secreção de CI e nem a produção de nitrito no sobrenadante das culturas, tanto em HGF como em HPLF. O silenciamento do receptor AT1 reduziu a secreção de IL-6 e IL-8 induzida por IL-1ß em cultura de HGF e HPLF e aumentou a expressão gênica de OPG somente em HGF. Estes resultados sugerem que o silenciamento de AT1, mas não o bloqueio farmacológico deste receptor pelo antagonista Losartan, em HGF e HPLF, pode controlar a produção de IL-6 e IL-8, que por sua vez contribuem para a patogênese periodontal.(AU)

The renin-angiotensin system (RAS) has been reported as an important modulator of inflammatory and immune responses, including periodontal disease (PD). Studies suggest an alternative axis as part of this system (ACE-2 / ANG (1-7) / MAS) that would act as counter-regulatory to the classical axis (ECA / ANGII / AT1). It is known that periodontal bacteria such as Porphyromonas gingivalis (Pg) have bioactive components in their membrane (such as lipopolysaccharide-LPS) capable of inducing a strong immune response in the host due to the release of cytokines in cells, including interleukin (IL) - 1ß. In this regard, fibroblasts are the most abundant cells in periodontal tissues and receptors needed for the recognition of bacterial invasion by activating intracellular cascades that lead to cytokine production. The aim of this study was to determine whether the axes ACE / ANGII / AT1 and ACE-2 / ANG (1-7) / MAS contribute to the production and / or regulation of inflammatory cytokines (IC) by fibroblasts of human gingiva (HGF) and human periodontal ligament (HPLF) stimulated IL-1ß. After pre-treatment with Losartan, Ang (1-7) or silencing mediated by RNA interference (RNAi) of AT1, HGF and HPLF were stimulated by IL-1ß for 3 hours (RNAm) or 24 hours (protein). Expression mRNA for AT1, MAS, ACE, ACE-2, IL-1ß, TNF-α, IL-6, IL-8, IL-10, TGF-ß, CXCL12, RANK-L and OPG was assessed by RT- qPCR and proteins IL-6, IL-8, ACE and ACE-2 by ELISA. Western Blot for the detection of AT1 and ECA and dosage of nitrite was also performed. Experiments stimulated by IL-1ß showed a positive control for gene expression AT1, IL-1ß, IL-6, IL-8, TNF-α and OPG in HGF and HPLF and MAS, ACE and TGF-ß only HPLF. Losartan and Ang (1-7) did not modulate the transcription and secretion of IC and no nitrite production in the culture supernatant of HGF and HPLF. The silencing AT1 reduced IL-6 secretion and IL-8 induced by IL- ß in cultured HGF and HPLF and increased OPG gene expression only HGF. These results suggest that silencing AT1, but not pharmacological blockade of this receptor by Losartan in HPLF and HGF, can control the production of IL-6 and IL-8, which in turn contribute to the pathogenesis of periodontal disease.(AU)

Relationship between Myocardial Extracellular Space Expansion Estimated with Post-Contrast T1 Mapping MRI and Left Ventricular Remodeling and Neurohormonal Activation in Patients with Dilated Cardiomyopathy

OBJECTIVE: Post-contrast T1 values are closely related to the degree of myocardial extracellular space expansion. We determined the relationship between post-contrast T1 values and left ventricular (LV) diastolic function, LV remodeling, and neurohormonal activation in patients with dilated cardiomyopathy (DCM). MATERIALS AND METHODS: Fifty-nine patients with DCM (mean age, 55 +/- 15 years; 41 males and 18 females) who underwent both 1.5T magnetic resonance imaging and echocardiography were enrolled. The post-contrast 10-minute T1 value was generated from inversion time scout images obtained using the Look-Locker inversion recovery sequence and a curve-fitting algorithm. The T1 sample volume was obtained from three interventricular septal points, and the mean T1 value was used for analysis. The N-Terminal pro-B-type natriuretic peptide (NT-proBNP) level was measured in 40 patients. RESULTS: The mean LV ejection fraction was 24 +/- 9% and the post-T1 value was 254.5 +/- 46.4 ms. The post-contrast T1 value was significantly correlated with systolic longitudinal septal velocity (s'), peak late diastolic velocity of the mitral annulus (a'), the diastolic elastance index (Ed, [E/e']/stroke volume), LV mass/volume ratio, LV end-diastolic wall stress, and LV end-systolic wall stress. In a multivariate analysis without NT-proBNP, T1 values were independently correlated with Ed (beta = -0.351, p = 0.016) and the LV mass/volume ratio (beta = 0.495, p = 0.001). When NT-proBNP was used in the analysis, NT-proBNP was independently correlated with the T1 values (beta = -0.339, p = 0.017). CONCLUSION: Post-contrast T1 is closely related to LV remodeling, diastolic function, and neurohormonal activation in patients with DCM.

Alteraciones de la hemostasia en el síndrome drepanocítico / Hemostasis alterations in sickle cell syndrome

El síndrome drepanocítico (SD) comprende un grupo de anemias hemolíticas hereditarias de tipo multisistémico asociadas a la hemoglobina S. Los pacientes que padecen este síndrome tienen un mayor riesgo, en comparación con individuos sanos, de presentar accidentes cerebrovasculares, hipertensión pulmonar, necrosis avascular de articulaciones, síndrome torácico agudo y complicaciones durante el embarazo, asociados a un estado de hipercoagulabilidad inducido por alteraciones en los diferentes componentes de la hemostasia, que incluyen la activación del endotelio y de los sistemas plaquetario, de la coagulación y de la fibrinólisis. Esta revisión resume las alteraciones en la hemostasia reportadas en los pacientes con SD, en los cuales se ha demostrado: mayor interacción de células endoteliales con leucocitos, hematíes y plaquetas; aumento de la expresión de proteínas de adhesión, como el factor von Willebrand y sus multímeros de alto peso molecular; aumento de la adhesión y la agregación plaquetaria y de la expresión de proteínas en sus membranas. En el sistema de coagulación se ha detectado aumento en la expresión del factor tisular (FT) en micropartículas derivadas de diferentes células, aumento de marcadores de activación de este sistema, entre estos los fragmentos 1.2 de la protrombina y los complejos trombina-antitrombina y una disminución de las proteínas C y S que actúan como anti-coagulantes. Adicionalmente, se han encontrado aumentados los marcadores de activación del sistema fibrinolítico como los dímeros D y los complejos plasmina/antiplasmina. Todas estas manifestaciones favorecen la aparición de complicaciones trombóticas, implicadas en el deterioro de la calidad de vida de los pacientes. Se recomienda implementar en el diagnóstico y seguimiento de esta enfermedad, la determinación de variables del sistema hemostático, con el fin de identificar alteraciones en etapas tempranas y aplicar terapias que puedan prevenir complicaciones trombóticas.

Sickle cell syndrome (SCS) includes a group of congenital hemolytic anemias associated to the presence of hemoglobin S, which is characterized by acute pain episodes and progressive damage of different organs. Some patients with sickle cell syndrome have shown, when compared with healthy individuals, an increased risk of presenting stroke, pulmonary hypertension, avascular necrosis of joints, acute chest syndrome and pregnancy complications, associated to a hypercoagulable state induced by alterations in different components of hemostasis, such as changes that include activation of the endothelium, platelet activity, coagulation and fibrinolytic systems. This paper compiles hemostasis disorders, associated with thrombotic manifestations, reported until now in sickle cell syndrom. These patients have an increase in activation markers of the coagulation system, such as prothrombin fragment 1.2, thrombin-antithrombin complex, etc., depletion of natural anticoagulant proteins, abnormal activation of the fibrinolytic system and increased tissue factor expression. Similarly, abnormal expression of glycoproteins and increased adhesion and platelet aggregation have been reported. All these alterations produce a hypercoagulable state, which induces, among other things, the appearance of thrombotic complications. In view of the importance of controlling the different complications that can occur in patients with sickle cell syndrome, we recommend the implementation, in diagnosis and monitoring studies, of the evaluation of the different components of the hemostatic system, identifying alterations at an early stage and applying effective treatments to prevent thrombotic complications.

The five-point Likert scale for dyspnea can properly assess the degree of pulmonary congestion and predict adverse events in heart failure outpatients

OBJECTIVES: Proper assessment of dyspnea is important in patients with heart failure. Our aim was to evaluate the use of the 5-point Likert scale for dyspnea to assess the degree of pulmonary congestion and to determine the prognostic value of this scale for predicting adverse events in heart failure outpatients. METHODS: We undertook a prospective study of outpatients with moderate to severe heart failure. The 5-point Likert scale was applied during regular outpatient visits, along with clinical assessments. Lung ultrasound with ≥15 B-lines and an amino-terminal portion of pro-B-type natriuretic peptide (NT-proBNP) level >1000 pg/mL were used as a reference for pulmonary congestion. The patients were then assessed every 30 days during follow-up to identify adverse clinical outcomes. RESULTS: We included 58 patients (65.5% male, age 43.5±11 years) with a mean left ventricular ejection fraction of 27±6%. In total, 29.3% of these patients had heart failure with ischemic etiology. Additionally, pulmonary congestion, as diagnosed by lung ultrasound, was present in 58% of patients. A higher degree of dyspnea (3 or 4 points on the 5-point Likert scale) was significantly correlated with a higher number of B-lines (p = 0.016). Patients stratified into Likert = 3-4 were at increased risk of admission compared with those in class 1-2 after adjusting for age, left ventricular ejection fraction, New York Heart Association functional class and levels of NT-proBNP >1000 pg/mL (HR = 4.9, 95% CI 1.33-18.64, p = 0.017). CONCLUSION: In our series, higher baseline scores on the 5-point Likert scale were related to pulmonary congestion and were independently associated with adverse events during follow-up. This simple clinical tool can help to identify patients who are more likely to decompensate and whose treatment should be intensified. .

Clinical and pathological correlations of C4d immunostaining and its infl uence on the outcome of kidney transplant recipients / Correlações clinico-patológicas da marcação de C4d e sua influência na evolução de receptores de transplante renal

INTRODUCTION: C4d is a marker of antibody-mediated rejection (ABMR) in kidney allografts, although cellular rejection also have C4d deposits. OBJECTIVE: To correlate C4d expression with clinico-pathological parameters and graft outcomes at three years. METHODS: One hundred forty six renal transplantation recipients with graft biopsies by indication were included. C4d staining was performed by paraffin-immunohistochemistry. Graft function and survival were measured, and predictive variables of the outcome were determined by multivariate Cox regression. RESULTS: C4d staining was detected in 48 (31 percent) biopsies, of which 23 (14.7 percent) had diffuse and 25 (16 percent) focal distribution. Pre-transplantation panel reactive antibodies ( percentPRA) class I and II were significantly higher in C4d positive patients as compared to those C4d negative. Both glomerulitis and pericapillaritis were associated to C4d (p = 0.002 and p < 0.001, respectively). The presence of C4d in biopsies diagnosed as no rejection (NR), acute cellular rejection (ACR) or interstitial fibrosis/ tubular atrophy (IF/TA) did not impact graft function or survival. Compared to NR, ACR and IF/TA C4d-, patients with ABMR C4d+ had the worst graft survival over 3 years (p = 0.034), but there was no difference between ABMR versus NR, ACR and IF/TA that were C4d positive (p = 0.10). In Cox regression, graft function at biopsy and high percentPRA levels were predictors of graft loss. CONCLUSIONS: This study confirmed that C4d staining in kidney graft biopsies is a clinically useful marker of ABMR, with well defined clinical and pathological correlations. The impact of C4d deposition in other histologic diagnoses deserves further investigation.

INTRODUÇÃO: A fração do complemento C4d é um marcador de rejeição mediada por anticorpos (RMA) em aloenxertos renais, embora na rejeição celular também se observem depósitos de C4d. OBJETIVOS: Correlacionar a expressão de C4d com parâmetros clínicopatológicos e a evolução do enxerto renal em três anos. MÉTODOS: Foram incluídos 146 receptores de transplante renal com biópsias por indicação. A marcação de C4d foi feita por imuno-histoquímica em parafina. Foram medidas a função e a sobrevida do enxerto e determinadas as variáveis preditivas de sua evolução por meio de modelo de regressão de Cox. RESULTADOS: A marcação positiva para C4d foi detectada em 48 (31 por cento) biópsias, das quais 23 (14,7 por cento) tinham marcação difusa e 25 (16 por cento), focal. A reatividade contra painel ( por centoPRA) de classe I e II pré-transplante foi significativamente maior nos pacientes C4d+ quando comparada aos C4d-. Tanto glomerulite quanto pericapilarite foram associadas com C4d (p = 0,002 e p < 0,001, respectivamente). A presença de C4d em biópsias sem rejeição (SR), rejeição celular aguda (RCA) ou fibrose intersticial/atrofia tubular (FI/AT) não teve impacto na função ou na sobrevida do enxerto. Comparados a indivíduos com SR, RCA e FI/AT C4d-, pacientes com RMA C4d+ tiveram pior sobrevida do enxerto em 3 anos (p = 0,034), mas não houve diferença entre RMA versus SR, RCA e FI/AT C4d+ (p = 0,10). Na regressão de Cox, função do enxerto no momento da biópsia e por centoPRA alto foram preditores de perda do enxerto. CONCLUSÕES: A pesquisa de C4d em biópsias do enxerto renal é útil para identificar RMA, com correlações clínicopatológicas bem definidas. O impacto do C4d em outros diagnósticos histológicos necessita de investigação adicional.

Structural analysis of human respiratory syncytial virus P protein: identification of intrinsically disordered domains

Human Respiratory Syncytial Virus P protein plus the viral RNA, N and L viral proteins, constitute the viral replication complex. In this report we describe that HRSV P protein has putative intrinsically disordered domains predicted by in silico methods. These two domains, located at the amino and caboxi terminus, were identified by mass spectrometry analysis of peptides obtained from degradation fragments observed in purified P protein expressed in bacteria. The degradation is not occurring at the central oligomerization domain, since we also demonstrate that the purified fragments are able to oligomerize, similarly to the protein expressed in cells infected by HRSV. Disordered domains can play a role in protein interaction, and the present data contribute to the comprehension of HRSV P protein interactions in the viral replication complex.

Clinical correlation of multiple biomarkers for risk assessment in patients with acute coronary syndrome.

OBJECTIVE: Biochemical markers are useful for the prediction of future cardiovascular events in patients with non-ST-segment elevation acute coronary syndrome (ACS). The independent as well as the combined prognostic value of elevated troponin-T, high-sensitivity C-reactive protein (hs-CRP), and N-terminal pro-brain natriuretic peptide (NT-pro-BNP) on the Thrombolysis In Myocardial Infarction (TIMI) risk score and on the short-term prognosis were evaluated in a cohort of ACS patients. METHODS AND RESULTS: In an unselected, heterogeneous group of 80 patients with ACS (i.e., unstable angina [USA] or non-ST-elevation myocardial infarction [NSTEMI]), the levels of troponin-T, hs-CRP, and NT-pro-BNP were analyzed. The correlation between elevation of different biomarkers with TIMI risk score and their impact on 30-day major adverse cardiac events was sought. The levels of hs-CRP were significantly higher in patients who had angina as their predominant complaint (3.67 mg/dl vs. 1.67 mg/dl: p < 0.01), while levels of NT-pro-BNP was higher in those patients who had any element of heart failure at presentation (2616.39 pg/ml vs. 1068.3 pg/ml; p < 0.01). Troponin-T was highest in patients who had an element of both heart failure and angina at presentation (p < 0.01). The TIMI risk score expectedly had a positive and strong correlation with elevated troponin-T, but had no correlation with elevation of hs-CRP and NT-pro-BNP in isolation. However, when any two biomarkers were elevated, the patients were in the intermediate risk group as per TIMI risk score irrespective of troponin-T-elevation. When all the three biomarkers were elevated, the risk equaled the high-risk category of TIMI risk score. Elevated hs-CRP (3.40 mg/dl vs. 1.38 mg/dl; p < 0.001) and troponin-T (2.37 ng/ml vs. 1.23 ng/ml; p < 0.001) at baseline correlated independently with the occurrence of re-ischemia, while elevated NT-pro-BNP alone correlated significantly with the development of heart failure within 30 days of follow-up (4247.76 pg/ml vs. 1210.86 pg/ml; p < 0.01). The highest risk of death from any cardiovascular cause within 30 days of follow-up was significantly higher when all the three biomarkers were elevated. CONCLUSION: The use of NT-pro-BNP, hs-CRP, and troponin-T in combination appears to add critical prognostic insight to the assessment of patients with ACS.

Diagnosis of acute humoral rejection using immunofluorescence in renal allograft biopsies- one step towards better understanding!

Immunofluorescence (IF) studies are important diagnostic tool in understanding pathogenesis involved in graft injury. Acute humoral rejection (AHR) associated with circulating donor-specific cytotoxic antibodies, is a poor prognosticator for graft survival. It can be diagnosed by staining for C4d antibody using indirect IF technique. C4d staining required to diagnose AHR was made mandatory for reporting renal allograft biopsies in 7th Banff conference. We present 2 years experience of IF studies using C4d polyclonal antibody on 546 renal allograft biopsies belonging to two groups of patients; 464 from group A (tolerance induction protocol) and 82 from group B (controls). We observed C4d focal positivity in 4 (0.9%) biopsies from group A and 4 (4.9%) from group B. We conclude that it is advisable to collect simultaneous core biopsy samples for IF studies and light microscopy to give better definition of allograft injury and thereby support in clinical management.

Activation of Intrarenal Complement System in Mouse Model for Chronic Cyclosporine Nephrotoxicity

PURPOSE: Local activation of the complement system plays a role in target organ damage. The aim of our study was to investigate the influence of cyclosporine (CsA)- induced renal injury on the complement system in the kidney. MATERIALS AND METHODS: Mice fed a low salt (0.01%) diet were treated with vehicle (VH, olive oil, 1mL/kg/day) or CsA (30mg/kg/day) for one or four weeks. Induction of chronic CsA nephrotoxicity was evaluated with renal function and histomorphology. Activation of the complement system was assessed through analysis of the expression of C3, C4d, and membrane attack complex (MAC), and the regulatory proteins, CD46 and CD55. CsA treatment induced renal dysfunction and typical morphology (tubulointerstitial inflammation and fibrosis) at four weeks. RESULTS: CsA-induced renal injury was associated with increased the expression of C3, C4d, and MAC (C9 and upregulation of complement regulatory proteins (CD 46 and CD55). Immunohistochemistry revealed that the activated complement components were mainly confined to the injured tubulointerstitium. CONCLUSION: CsA-induced renal injury is associated with activation of the intrarenal complement system.

Peritubular Capillary C4d Deposition in Chronic Allograft Dysfunction

Peritubular capillary (PTC) C4d staining represents a marker for acute humoral rejection, however, the impact of positive staining on chronic allograft dysfunction has received little attention. Ninety-three renal allograft biopsies from 93 patients were selected from a total of 174 renal allograft biopsies, which were obtained 6 months or more after transplantation (median: 89 months). Fresh frozen renal tissue was stained with monoclonal antibody against C4d. Sixteen of 93 biopsies showed C4d staining in PTC. C4d staining was positive in 40% of acute rejection cases (n=15) and 21% of chronic rejection cases (n=24). When the samples were divided according to C4d positivity, the C4d (+) group had a higher proportion of acute rejection than the C4d (-) group. However, no significant difference was observed between the two groups in terms of the prevalence of chronic rejection. Degrees of histological injury including tubulitis, interstitial inflammation and interstitial fibrosis were not significantly different between C4d (+) and C4d (-) groups. However, the 2-year graft survival rate after biopsy was lower in the C4d (+) group than in the C4d (-) group (24.8% versus 59.0%, p=0.1255). C4d staining in PTC is associated with late acute rejection, but not with chronic rejection based on conventional morphologic criteria in patients with chronic allograft dysfunction.

Menores niveles de angiotensina (1-7) en pacientes hipertensos esenciales con genotipo ECA deleción/deleción / Lower levels of angiotensin (1-7) in hypertensive patients with the deletion/deletion ace genotype

Una menor actividad de enzima convertidora de angiotensina I, genéticamente determinada en aproximadamente un 40 por ciento en humanos , determinaría mayores niveles de Ang (Ang) II, lo que no ha sido observado. Sin embargo, no se conoce lo que ocurre en este contexto con los niveles de Ang (1-7), un péptido con acciones vasodilatadores y antiproliferativas antogónicas a las que ejerce Ang II. Hipótesis: los niveles de este péptido pudieran elevarse en presencia de niveles más bajos de ECA (sujetos homocigotos ECA II) en relación con los pacientes homocigotos ECA DD (con ECA genéticamente más lata). Métodos: se estudiaron 18 pacientes hipertensos esenciales homocigotos sin tratamiento (9 ECA DD y 9 ECA II). Se determinó actividad de ECA y niveles de angiotensinas II y (1-7) plasmáticos. Resultados (promedio ± 12,9 ng/ml vs 69,6 ± 8,4 ng/ml). Sin embargo los niveles de Ang (1-7) fueron 4 veces más elevados en los pacientes hipertensos con genotipo ECA II (58,2 ±18,8 ng/ml vs 14,5 ± 3,3 ng/ml, p <0,05). Conclusión: La presencia de mayor actividad de ECA determinada genéticamente, se asocia con menores niveles plasmáticos de Ang (1-7). Este fenómeno pudiera estar mediado por diferente actividad de ECA y/o de endopeptidasa neutra y ayudaría a explicar algunos fenómenos patogénicos asociados a la presencia del alelo D en humanos.

Utilidad del fragmento 1 + 2 de protrombina y del dímero de fibrina en la detección de hipercoagulabilidad en pacientes obstétricos con factores de riesgo de trombosis / Usefulness of 1 + 2 prothrombin fragment and of dimer of fibrin in detecting hyporcoagulability in obstetricial patients with thrombosis risk

La cuantificación del fragmento 1+2 de protrombina se hizo por método inmunoenzimático en 75 mujeres (55 embarazas y 20 post-cesárea) y el dímero D por determinación semicuantitativa mediante aglutinación en placa en 97 casos (77 embarazadas y 20 post-cesárea). El fragmento 1+2 se encontró significativamente elevado en el 85 por ciento de los casos, sin embargo no mostró tener utilidad predictiva de enfermedad tromboembólica. La cuantificación del dímero D no fue detectada en 40 casos, en 33 fluctuó entre 500 y 1000 ng/ml y en los 24 restantes fue superior a los 2000 ng/ml. Valores mayores a 1000 ng/ml fueron observados en el 78 por ciento de las que tenían antecedentes de enfermedad tromboembólica, en las de cesárea 60 por ciento, en el 37 por ciento de las hipertensas y en 23 por ciento de las diabéticas. El dímero D que en el 59 por ciento de las embarazadas y puérperas registró valores superiores a 500 ng/ml tiene valor predictivo, ya que en 24 casos que cursaban con más de 2000 ng/ml, el 25 por ciento presentaron ETE y/o anormalidades de la coagulación sugestivos de actividad trombótica. Estos hallazgos no fueron observados en la 73 mujeres evaluadas que tuvieron dD negativo o < de 1000 ng/ml

NMR and molecular dynamics studies of tachykinins: conformation of the C-terminal pentapeptide of substance P(SP7-11).

Substance P belongs to the tachykinin family of neuropeptides which exhibit diverse pharmacological activity. The conformation of Phe1-Phe2-Gly3-Leu4-Met5-NH2 the C-terminal pentapeptide of substance P (SP7-11) has been studied by NMR and molecular dynamics (MD) methods. NMR studies were carried out both in DMSO-d6 and 95% H2O. Based on the observed chemical shifts, 3JNH alpha coupling constants, temperature coefficients of chemical shifts of NH resonances and the pattern of inter- and intraresidue NOE's, a predominantly extended backbone conformation has been deduced for the peptide in both DMSO and H2O. MD calculations carried out in vacuo indicate that the global minimum energy conformation of the molecule is folded with an intramolecular hydrogen bond between the protonated N-terminal and the C-terminal CONH2 group. The simulation shows that beta-turns are energetically unfavourable, while alpha-helices are seen to be unstable for the peptide. gamma-Bends at either Gly3 or Leu4 are the most preferred ones. Simulations carried out in DMSO as well as in water show a preference for a nearly extended conformation.

Effect of different oral anticoagulant intensities on prothrombin fragment 1 + 2 in Thai patients with mechanical heart valve prostheses.

The minimal intensity of oral anticoagulant required for antithrombotic protection in patients with a mechanical heart valve is still debatable, and that of the Westerner may not be directly applied to Thai patients. Our preliminary clinical review suggested that International Normalized Ratio (INR) 2-3 might be enough but it needs further supporting evidence. Therefore, we studied the effect of different anticoagulant intensities, expressed as INR, on the in vivo coagulation activation by measuring prothrombin fragment 1 + 2 (F1 + 2) in 116 patients with mechanical heart valve replacements. The patients had received warfarin for not less than one month with different intensities. The mean +/- S.D. of F1 + 2 level in 30 normal controls was 0.7 +/- 0.17 nmol/L. After excluding two outliers, the maximum linear correlation between INR and F1 + 2 was -0.658 (p < 0.001) when only patients whose intensities were lower than INR3 were taken into account. Adding more data from the patients having higher intensities decreased the correlation coefficient. The patients were subsequently classified by INR values in the range INR 1.1-1.9, 2-3 and 3.1-4.2. The F1 + 2 in each group was 0.6 +/- 0.30, 0.28 +/- 0.13 and 0.24 +/- 0.13 nmol/L respectively. The F1 + 2 in the first group did not differ from normal (p = 0.119) but was higher than the others (p = 0.000). The latter two groups had no difference between them (p = 0.112). Hence, from the laboratory point of view, we did not see additional benefit in the reduction of thrombin activation by the anticoagulant intensities higher than the range INR 2-3. The evidence supported that this therapeutic range might be enough for Thai patients with mechanical heart valves.

V3 peptide enzyme immunoassay for serotyping HIV-1 infected pregnant Thais.

Previous molecular epidemiological studies show that at least 2 subtypes of HIV-1 circulate in Thailand. HIV-1 subtype B or Thai genotype B was associated with an early epidemic and was prevalent in intravenous drug users. Meanwhile, HIV-1 subtype E or Thai genotype A was becoming widespread among heterosexuals. We studied the HIV subtypes of 161 HIV-1 seropositive pregnant women. Of these, 143 pregnant patients (88.8%) tested positive for subtype E alone and 8 women (5.0%) had evidence of infection with subtype B alone. There was serologic evidence of infection with a mixture of subtypes in 7 women while the infecting subtype could not be identified in the remaining 3 women. This result agrees with previous information that subtype E predominates in Thai heterosexuals.

Characterization of poly- and monoclonal antibodies to physalis mottle (tymo) virus.

Polyclonal antibodies were raised against the Physalis mottle virus (PhMV) and its denatured coat protein (PhMV-P). Analysis of the reactivity of the polyclonal antibodies with tryptic peptides of PhMV-P in dot-blot assays revealed that many of the epitopes were common to intact virus and denatured coat protein. Five monoclonal antibodies to the intact virus were obtained using hybridoma technology. These monoclonal antibodies reacted well with the denatured coat protein. Epitope analysis suggested that probably these monoclonal antibodies recognize overlapping epitopes. This was substantiated by epitope mapping using the CNBr digest of PhMV-P in western blots. All the five monoclonals recognized the N-terminal 15 K fragment. Attempts to further delineate the specific region recognized by the monoclonals by various enzymatic cleavages resulted in the loss of reactivity in all the cases. The results indicate that these monoclonals probably recognize epitopes within the N-terminal 15 K fragment of the coat protein.