In silico evaluation of the Eucalyptus transcriptome

The expressed sequence tags (ESTs) produced in the Forests project provide an invaluable opportunity to assess the Eucalyptus transcriptome. Besides providing information on the different proteins produced by this plant, it is possible to infer gene expression profiles because non-normalized cDNA libraries were used. The EST frequency from any gene is correlated to the transcript levels in the tissues from which the cDNA libraries were constructed. The goal of this work was to identify Eucalyptus genes that showed either differential expression pattern or were ubiquitously expressed in the tissues sampled in the Forests project. Six robust statistical tests and very restrictive rules were applied to gain confidence in the in silico data aiming to avoid false positives. Several genes with interesting expression profiles were identified and some of them were validated by RT-PCR

Eucalyptus ESTs involved in the production of 9-cis epoxycarotenoid dioxygenase, a regulatory enzyme of abscisic acid production

Abscisic acid (ABA) regulates stress responses in plants, and genomic tools can help us to understand the mechanisms involved in that process. FAPESP, a Brazilian research foundation, in association with four private forestry companies, has established the FORESTs database (https://forests.esalq.usp.br). A search was carried out in the Eucalyptus expressed sequence tag database to find ESTs involved with 9-cis epoxycarotenoid dioxygenase (NCED), the regulatory enzyme for ABA biosynthesis, using the basic local BLAST alignment tool. We found four clusters (EGEZLV2206B11.g, EGJMWD2252H08.g, EGBFRT3107F10.g, and EGEQFB1200H10.g), which represent similar sequences of the gene that produces NCED. Data showed that the EGBFRT3107F10.g cluster was similar to the maize (Zea mays) NCED enzyme, while EGEZLV2206B11.g and EGJMWD2252H08.g clusters were similar to the avocado (Persea americana) NCED enzyme. All Eucalyptus clusters were expressed in several tissues, especially in flower buds, where ABA has a special participation during the floral development process

N-glycosylation in sugarcane

A N-glicosilaçäo é uma das principais modificações pós-tradicionais, sendo responsável por alterações na conformaçäo, estabilidade e conseqüentemente na funcionalidade de proteínas em eucariotos. Com a finalidade de melhor compreender a via de N-glicosilaçäo em plantas foi realizada uma prospecçäo no banco de seqüências expressas do projeto genoma da cana de açúcar (SUCEST). Foram identificadas noventa seqüências cujos produtos gênicos apresentam alto grau de similaridade com enzimas envolvidas na biossíntese e processamento de N-glicanos. Dos vinte e três genes da via de N-glicosilaçäo previamente descritos em diferentes espécies, vinte e um foram detectados em cana de açúcar.

Cardiomiopatia arritimogênica do ventrículo direito. Valor preditivo da dispersäo do intervalo QT para avaliaçäo de risco arritmogênico e de morte súbita / Arrhythmogenic cardiomyopathy of the right ventricle. Predictive value of QT interval dispersion to assess arrhythmogenic risk and sudden death

OBJECTIVE: To determine in arrhythmogenic right ventricular cardiomyopathy the value of QT interval dispersion for identifying the induction of sustained ventricular tachycardia in the electrophysiological study or the risk of sudden cardiac death. METHODS: We assessed QT interval dispersion in the 12-lead electrocardiogram of 26 patients with arrhythmogenic right ventricular cardiomyopathy. We analyzed its association with sustained ventricular tachycardia and sudden cardiac death, and in 16 controls similar in age and sex. RESULTS: (mean +/- SD). QT interval dispersion: patients = 53.8+/-14.1ms; control group = 35.0+/-10.6ms, p=0.001. Patients with induction of ventricular tachycardia: 52.5+/-13.8ms; without induction of ventricular tachycardia: 57.5+/-12.8ms, p=0.420. In a mean follow-up period of 41+/-11 months, five sudden cardiac deaths occurred. QT interval dispersion in this group was 62.0+/-17.8, and in the others it was 51.9+/-12.8ms, p=0.852. Using a cutoff > or = 60ms to define an increase in the degree of the QT interval dispersion, we were able to identify patients at risk of sudden cardiac death with a sensitivity of 60 percent, a specificity of 57 percent, and positive and negative predictive values of 25 percent and 85 percent, respectively. CONCLUSION: Patients with arrhythmogenic right ventricular cardiomyopathy have a significant increase in the degree of QT interval dispersion when compared with the healthy population. However it, did not identify patients with induction of ventricular tachycardia in the electrophysiological study, showing a very low predictive value for defining the risk of sudden cardiac death in the population studied.

Síndrome de Brugada: observaçöes sobre a evoluçä de um caso / The Brugada syndrome: outcome of one case

The Brugada syndrome is a rare condition, and due to its mutating manner of presentation it may be difficult to diagnose. We report one case and discuss the diagnostic aspects and the clinical outcome of one patient with characteristic findings of this syndrome. These findings are especially defined by J-ST elevation in the right leads of serial electrocardiographic records, wide oscillations of J points and ST segments during 24-hour Holter monitoring, and nocturnal sudden death. We stress the importance of the Holter monitor findings for diagnostic complementation. Through this method it is possible to establish a correlation between vigil activities and sleep and the variability of the degree of impairment in ventricular repolarization.

Bradarritmias na sala de emergência / Bradyarrhythmias in the emergency room

Tem sido reconhecido, há muito tempo, que o ritmo cardíaco extremamente lento é capaz de produzir sintomas severos. As bradiarritmias sintomáticas implicam em distúrbios da função sinusal, da condução AV, ou de ambos. As causas dessas anormalidades podem ser classificadas, de uma maneira ampla em: 1) distúrbios intrínsecos, 2) distúrbios extrínsecos, ou 3) distúrbios funcionais reflexos mediados neuralmente. A disfunção do nódulo sinusal (ou doença do nódulo sinusal) compreende um espectro de arritmia do nódulo sinusal e/ou atriais, que resultam em períodos intermitentes ou persistentes de batimentos cardíacos inapropriados, lentos ou rápidos. Distúrbios da condução AV abrangem desde alentecimento da condução AV, à falta intermitente da transmissão do impulso, até completa falha da condução. Na maioria dos casos, a estimulação cardíaca artificial substituiu a terapia farmacológica no tratamento de pacientes com bradiarritmia sintomática. A disfunção dos MP, em pacientes dependentes do mesmo, representa também uma importante causa de períodos intermitentes de ritmo cardíaco lento sintomático

Síncope: Avaliação diagnóstica e conduta / Syncope: Diagnostic assessment and procedure

Este artigo tem como finalidade oferecer aos clínicos uma atualização sobre síncope, suas causas, mecanismos fisiopatológicos envolvidos bem como as condutas terapêuticas atuais. Consideraçöes especiais serão dirigidas à síncope cardio-neurogênica, sua importância clínica e as diversas opçöes atuais de tratamento. Discutiremos as indicaçöes e metodologias utilizadas no teste de inclinação, bem como a sua utilidade para a definição das diversas formas de apresentação da síncope cardio-neurogênica.

Avaliação das arritmias ventriculares na cardiopatia isquêmica / Assessment of ventricular arrhytthmias in ischemic cardiopathy

As arritmias cardíacas nas fases iniciais do infarto do miocárdio estão relacionadas principalmente ao processo de base (isquemia). Existe uma significativa variabilidade na ocorrência e frequência de taquicardia ventricular não sustentada pós-IAM. Os efeitos da isquemia nas propriedades eletrofisiológicas do músculo cardíaco são inúmeras e complexas. A identificação de pacientes com risco para alta mortalidade e morbidade pós-infarto permite uma base racional para se individualizar estratégias diagnósticas e terapêuticas. A estratificação de risco pode oferecer valiosas informaçöes sobre os mecanismos de risco e, desse modo, aumentar o nosso entendimento dos processos patológicos envolvidos. O uso de testes não invasivos para predizer eventos arrítmicos pós-IAM cresceu significativamente.

Modificaçäo do nódulo sinusal via cateter por energia de radiofreqüência em pacientes com taquicardia sinusal inapropriada. Avaliaçäo dos resultados imediatos e tardios / Sinus node modification by catheter using radiofrequency current in a patient with inappropriate sinus tachycardia. Evaluation of early and late results

Säo apresentados os resultados imediatos e tardios, observados com a modificaçäo do nódulo sinusial via cateter, usando-se energia de radiofreqüência, em portadora de taquicardia sinusal inapropriada. O procedimento normalizou os níveis de freqüência cardíaca nas 24h seguintes e após seis seis meses, mostrando-se, portanto,efetivo e seguro. Apesar da reduçäo da freqüência cardíaca a níveis normais, houve manutençäo dos sintomas apresentados pela paciente, sugerindo que näo säo decorridos, exclusivamente, do processo taquicárdico.

Taquicardia sinusal inapropriada: análise espectral dos ciclos R-R normais / Inapropriate sinus tachycardia: spectral analysis of normal R-R cycles

OBJETIVOS: avaliar o perfil autonômico da taquicardia sinusal inapropriada (TSI) por análise espectral da variabilidade da frequência cardíaca (VFC). PACIENTES E MÉTODOS: foram estudados 05 pacientes (pts), três masculinos, idade média global de 25ñ 8 anos. todos foram submetidos a Holter-24 hs, determinando-se, nos registros, os ciclos cardíacos médios (CC - ms) e os seguintes componentes espectrais da VFC por método autoregressivo: energia total do espectro (ETE - ms2), componente de baixa frequência (CBF -ms2 - 0,04-0, 15 Hz), de alta frequência (CAF -ms2 - 0,15-0,40 Hz) e relaçöes entre CBF/CAF. Definiram-se os valores médios de todas as variáveis analisadas para as 24hs, para a vigília (V-10-18 hs) e sono (S-24-08hs). A dinâmica vigília/sono foi avaliada através de unidades normalizadas (un), representando o valor relativo do CBF e CAF em proporção a ETE menos o componente de muito baixa frequência. Os resultados foram comparados com os mesmos de um grupo controle (C) de 10 pts normais, idade sexo semelhantes e expressos pela média e 01 DP. RESULTADOS: CCM24hs - C: ... fórmulas ... CONCLUSÖES: os resultados observados indicam que a TSI cursa com depressão dos componentes espectrais da VFC consequentes a um aumento relativo da atividade simpática e baixa reatividade vagal. Os achados poderão ser responsáveis pela perpetuação do estado arrítmico observado, indicando haver nesta condição quador disautonômico bem definível.

Associação entre prolapso valvar mitral e doença ventricular direita arritmogênica / Association between Mitral Valve Prolapse and Arrhythmogenic Right Ventricular Disease

PURPOSE: To evaluate some features of ventricular arrhythmias in patients with mitral valve prolapse. METHODS: We studied 25 patients (female: 19; mean age: 37 +/- 13 years) with ventricular arrhythmias, mitral valve prolapse and normal ventricular function. All patients underwent a 24h Holter and high resolution ECG (HRECG). The Qtc intervals were measured in lead II (normal < 0.44 s). In order to define the possible origin of the ventricular focus, the morphology of the ectopic beats were analysed in leads I, II, aVF, V1 using the following criteria: 1) LBBB morphology with left axis deviation in the frontal plane (FP): origin at the inflow tract of the right ventricle (RV); 2) LBBB morphology with right axis deviation in the FP: origin at the outflow tract of the RV; 3) RBBB morphology with left axis deviation in the FP: origin at the posterior region of the left ventricle (LV). RBBB morphology with right axis deviation in the FP: origin at the anterior region of the LV. RESULTS: Twenty three (92) patients showed > 720 isolated ventricular ectopic beats/24 h. Paired ventricular response was detected in 18 (72) patients and non-sustained VT in 15 (60). HRECG was positive in six (24) patients and Qtc interval was prolonged in 13 (52). RV was the site of origin of the ventricular ectopic beats in 85 of the patients (outflow: 85; inflow: 15). Only five (20) patients had arrhythmias from the LV. CONCLUSION: There was a high incidence of ventricular arrhythmias with a low incidence of positive HRECG tests, suggesting that the mechanisms of the arrhythmias do not correlate with slow intramyocardial conduction. It was noted a strong association between mitral valve prolapse, arrhythmogenic right ventricular disease and Qtc prolongation. It is possible that in some of this patients the finding could represent a global myocardial disease.

Efeitos do sotalol sobre o eletrocardiograma de alta resoluçäo avaliados por ensaio duplo-cego cruzado randomizado / Effects of sotalol over signal-averaged electrocardiogram: a randomized double-blind crossover trial

A presente investigaçäo teve por objetivo avaliar os efeitos do Sotalol sobre o eletrocadiograma de alta resoluçäo (ECGAR), em uma populaçäo com arritmia ventricular idiopática. Foi estudado um grupo de 12 pacientes submetidos a um ensaio clínico do tipo duplo-cego cruzado e randomizado, para avaliaçäo da eficácia da droga. Foram obtidos ECGAR em condiçöes de controle (C), uso de placebo (P) e de droga (D). confrontando os resultados entre as três situaçöes e a eficácia medicamentosa. No vetor-magnitude foram analisados os seguintes parâmetros: voltagem média dos 40ms terminais do complexo QRS filtrado (VM - normal > 20 µV), duraçäo dos sinais de baixa amplitude < 40 µV no final da ativaçäo (SBA - normal < 38ms) e duraçäo total do complexo QRS filtrado (DQRS - normal < 114.0ms). Em funçäo da resposta terapêutica, os pacientes foram divididos em responsivos (G1) e näo-responsivos (G2). Näo foram observadas diferenças estatisticamente significativas entre C e P. No grupo I, composto por 5 pacientes (42 'por cento' de eficácia), näo foram observadas diferenças significativas nas 3 variáveis avaliadas entre as condiçöes de P e D. No grupo II, composto por 7 pacientes, ocorreram modificaçöes nos SBA, cujos valores no P estavam em 24.80 ñ 7.60ms e passando com D para 29.10 ñ 14.76ms (p<0,01). Em 5 dos 7 pacientes deste grupo (71 'por cento'), prolongam-se no pós-droga os SBA, numa média de 11.20 ñ 4.80ms, com significância estatística em relaçäo ao placebo (p<0,04). Frente aos resultados observados com os SBA, foram obtidos sensibilidade de 71'por cento', especificidade de 86 'por cento', valor preditivo positivo de 83 'por cento' e negativo de 75 'por cento' para definir a populaçäo responsiva à droga. Concluiu-se que na populaçäo estudada, o Sotalol, quando efetivo, nço produziu modificaçöes significativas nos parâmetros do ECGAR. Um incremento médio dos SBA de 11.2 ñ 4.8ms, por influência da droga, associou-se a uma ausência de resposta terapêutica.

Efficácia das drogas antiarrítmicas. Proposta para uma nova forma de avaliação baseada nos efeitos farmacológicos horários / Antiarrhythmic drug effectiveness. Proposal for a new approach based on pharmacological hourly effects

PURPOSE--To use a new approach in order to assess the antiarrhythmic drugs, based in the hourly autonomic effects and antiarrhythmic efficacy of sotalol. METHODS--Sixteen patients were evaluated in a randomized double-blind placebo-controlled study. Patients were classified in group 1 (anti-arrhythmic efficacy) and group 2 (no antiarrhythmic efficacy). The following parameters were analyzed: 1) clinical variables as age, gender, cardiac disease and ventricular ectopies density; 2) drug effects on pNN50 in 24-hour and on mean hourly cardiac cycle length; 3) percentage of hourly ventricular ectopies distribution and its correlation with pNN50 and with mean hourly cardiac cycle length in all patients; 4) drug effects on mean hourly cardiac cycle length in groups 1 and 2; 5) correlation between hourly pNN50 and ventricular ectopies density after sotalol administration in groups 1 and 2; 6) hourly drug efficacy in groups 1 and 2 and correlation with pNN50. RESULTS--Efficacy of the drug was present in 8 (50) patients. Sotalol significantly increased 24-hour pNN50 (placebo 5.01 +/- 2.02; after drug, 11.70 +/- 5.59-p < 0.001), also increasing mean hourly cardiac cycle length during the day and night, in all patients (placebo 758.25 +/- 75.68 ms; after drug 967.71 +/- 80.17 ms-p < 0.000). It was noted that patients under placebo had different autonomic tonus; group 1 showed higher sympathetic activity as compared to group 2. Hourly drug efficacy was seen in 23 of 24-hour recordings in group 1 while it was not seen at any time in group 2. CONCLUSION--Sotalol significantly increased parasympathetic cardiac activity. The anti-arrhythmic response was related to the autonomic tonus seen before and after drug administration.

Terapia ablativa do flutter atrial tipo I com radiofreqüência / Type I Atrial Flutter Ablation Therapy with Radiofrequency

PURPOSE--To present initial experience on radiofrequency (RF) ablation of atrial flutter (AFL) guided by anatomic and electrophysiologic parameters. METHODS--Eight patients (six males), mean-age of 42 +/- 17.5 years with chronic type I AFL (mean cycle length of 251 +/- 14.3 msec, range 240 to 280 msec) were undergone to RF catheter ablation applied between inferior vena cava (IVC) and tricuspid annulus (TA). Two had persistent and two the paroxysmal form. Two had surgical corrected congenital heart disease (atrial septal defect in 2 and ventricular septal defect in 1). Four had systolic dysfunction and 2, an atrial tachycardia associated with the AFL. RESULTS--Areas of slow conduction represented by fractionated potentials were recorded between IVC and TA in all patients. RF ablation was successful in 8/8 patients (100). The mean number of RF applications was 9.2 +/- 6.2 (4-24). The successful ablation site was located in the isthmus between IVC and TA in seven patients and in the lateral wall in the patient with ASD. Successful sites had an early atrial activation preceding the atrial electrogram (range from -65 to -82 ms). In one patient the RF energy was successfully delivered between the atriotomy scar (AS) and IVC. After three months follow-up six remained free of recurrent AFL. One pt had type 1 AFL recurrence and one with ASD had a type II AFL. The Type II AFL was successfully ablated between AS and IVC. CONCLUSION--Fractionated potentials were commonly observed between IVC and T; AFL ablation can be guided by anatomic landmarks or electrophysiologic parameters; electrograms recorded at successful sites were early and never fractionated; the long-term evaluation must be analyzed prospectively.

O eletrocardiograma de alta resolução da onda P em pacientes com história de fibrilação atrial paroxística / The P-Wave Signal-Averaged Electrocardiogram in Patients with Episodes of Paroxysmal Atrial Fibrillation

PURPOSE--To study by using the signal-averaged P wave, the atrial activation of patients with documented episodes of paroxysmal atrial fibrillation (PAF). METHODS--This study enrolled a total of 20 patients with documented episodes of paroxysmal atrial fibrillation (males 14; mean age 58.4 +/- 10.6 years). The signal-averaged P wave was recorded with a Corazonix Predictor II system. The total P wave duration was determined from the combined filtered x,y,z vector-magnitude and used for analysis. The results were compared with a normal group of 10 patients, matched in age. RESULTS--In the control group, the total P wave duration ranged from 120.0 to 135.0 (mean = 128.3 +/- 5.8) ms. In the group of PAF, the total P wave duration ranged from 118.0 to 168.5 (mean = 151.5 +/- 13.7) ms (p < 0.000). Sixteen (80) of this patients showed a P wave duration > 140.0 ms. With a cut < 140.0 ms for the normal atrial activation, the sensitivity was 76, specificity was 100, positive and negative predictive value were 100 and 60 respectively for the method detected patients with PAF. CONCLUSION--Patients with PAF showed a prolonged signal-averaged P wave duration and should be differentiated by this method from the normal population.