Results of the surgical treatment of chronic atrial fibrillation

OBJECTIVE: Report clinical experience in surgical treatment of atrial fibrillation (AF) by Cox-maze procedure. METHODS: 61 patients underwent surgical treatment for AF. Two had primary AF and 59 AF secondary to heart disease (2 atrial septal defects, 57 mitral). Ages ranged from 20 to 74 years (mean = 49). There were 44 females (72%). The surgical technique employed was Cox 3 without cryoablation. The patients were follow-up in specific at patient clinics and underwent periodical ECG, exercise tests, echocardiogram and Holter monitoring. RESULTS: In-hospital mortality was 4.9% and late mortality 1.6%. A temporary pacemaker was used in 28 (46%) and a definitive in 7 patients (11.4%). On hospital discharge, AF remained in 17%; 63.9% had sinus rhythm, 6.9% atrial rhythm, 1.7% junctional rhythm, and 10.3% had pacemaker rhythm. In the last evaluation, AF was present in 19.5%; (70.5% sinus rhythm, 4% atrial rhythm, 2% atrial tachycardia, and 4% pacemaker rhythm). There was no report of thromboembolic episodes. Chronotropic response was considered adequate in 19%, intermediate in 29%, and inadequate in 42%. In Holter monitoring, the mean heart rate was 82±8 bpm, with a minimum of 57±7 bpm and maximum of 126±23 bpm, with supraventricular extrasystoles in 2.3±5.5% of the total heartbeats and ventricular extrasystoles in 0.8±0.5%. In the echocardiogram, the A wave was present in the left atrium in 87.5%. CONCLUSION: Maze procedure is effective and has acceptable surgical risk. Atrial or sinus rhythms remain stable with a small but remarkable frequency of atrial and ventricular arrhythmias. Left atrial contraction is present, although attenuated, as well as the chronotropic response to exercise.

As fontes jornalísticas na era digital: relações e encenação

Dissertação de mestrado em Ciências da Comunicação (área de especialização em Informação e Jornalismo)

Comparison between tilt-table testing results performed during different periods of the day

OBJECTIVE: To evaluate the influences of circadian variations on tilt-table testing (TTT) results by comparing the positivity rate of the test performed during the morning with that of the test performed in the afternoon and to evaluate the reproducibility of the results in different periods of the day. METHODS: One hundred twenty-three patients with recurrent unexplained syncope or near-syncope referred for TTT were randomized into 2 groups. In group I, 68 patients, TTT was performed first in the afternoon and then in the morning. In group II, 55 patients, the test was performed first in the morning and then in the afternoon. RESULTS: The TTT protocol was the prolonged passive test, without drug sensitization. Twenty-nine (23.5%) patients had a positive result in at least one of the periods. The positivity rate for each period was similar: 20 (16.2%) patients in the afternoon and 19 (15.4%) in the morning (p=1.000). Total reproducibility (positive/positive and negative/negative) was observed in 49 (89%) patients in group I and in 55 (81%) in group II. Reproducibility of the results was obtained in 94 (90.4%) patients with first negative tests but in 10 (34%) patients with first positive tests. CONCLUSION: TTT could be performed during any period of the day, and even in the 2 periods to enhance positivity. Considering the low reproducibility rate of the positive tests, serial TTT to evaluate therapeutic efficacy should be performed during the same period of the day.

Horário por turnos : análise do seu efeito numa empresa do sector industrial

O presente estudo teve por objetivo analisar os possíveis efeitos do trabalho por turnos, incluindo o turno noturno, a nível da saúde, vida familiar e social, numa empresa do sector da indústria. Foi construído um questionário que abordava questões relativas aos dados sociodemográficos, organização temporal do trabalho, qualidade do sono, exigências da tarefa e envolvimento, saúde, vida familiar e social, e posteriormente foi aplicado a uma amostra de 24 trabalhadores com idades entre os 29 e os 52 anos (41,58±5,79 anos). Os resultados mostram uma tendência para doenças como a obesidade, colesterol elevado e manifestação de sintomas relacionados com problemas digestivos nos trabalhadores que trabalham por turnos à [sic] mais anos. Antes do primeiro turno noturno o tempo de sono é bastante reduzido e fica aquém do tempo que os trabalhadores sentem que necessitam dormir para se sentirem bem. O turno da tarde é o que permite os trabalhadores ficarem com um tempo de sono mais próximo desse “ideal”. Em relação à idade, todos os trabalhadores do grupo etário mais velho manifestam interrupções do sono diurno. Também se verifica um maior descontentamento destes trabalhadores com o tempo livre para realizar atividades que tragam bem-estar. Este estudo contribui para o conhecimento da realidade do trabalho por turnos na indústria e espera-se que desperte a procura de soluções que otimizem a vida destes trabalhadores.

Diel density variation of amphipods associated with Sargassum beds from two shores of Ubatuba, Southeastern, Brazil

Densities of mobile epifaunal assemblages associated with macrophytes are very variable during the day and the activity of visually-oriented predators is thought to have an important influence on this pattern. Here we compared densities of amphipods associated with a common brown alga, Sargassum stenophyllum (Phaeophyceae), at sites contrasting in water turbidity. We expected that diel variation of amphipods would occur in a shore with clear waters (Perequê), whereas no variation was expected in a shore with turbid waters (Lamberto). Amphipod density varied during the day at both shores, with no indication of a larger variation at Perequê. Most species showed two density peaks, one at night and the other in the afternoon. These peaks occurred close the times of high tide, suggesting that tidal rhythms could influence more amphipod densities than the activity of predators. Thus, more studies are necessary to understand factors that influence short-term variation of epifaunal assemblages.

Diet of Iheringichthys labrosus (Siluriformes, Pimelodidae) in the Ibicuí River, Southern Brazil

The diet of the benthic-feeding fish Iheringichthys labrosus (Lütken, 1874) was analyzed. Samples were taken bimonthly from December 1999 to January 2002, in three sites of the Ibicuí River, a tributary of Uruguay River basin (Rio Grande do Sul, Brazil). In each sampling point the specimens were collected in lentic and lotic environments. Gillnets and trammel nets were examined every 6 hours (6h, 12h, 18h and 24h). Diet description was based on the frequency of occurrence and the volume of each food item to obtain the Alimentary Index (IAi). The average stomach fullness was adopted to detect variations in the feeding activity according to the season, the circadian rhythm and the environment. Chironomids were the most important food item, followed by mollusks, and feeding activity was highest in summer, during daylight (6h and 12h), and in the lotic environment of the second sampling point.

Seasonal and diel variation in the fish assemblage of a Neotropical delta in southern Brazil

The objective of this study was to identify the patterns of seasonal and diel variation and the most important abiotic factors that influence variation in the fish assemblage of the Delta of the Jacuí River in southern Brazil. Seventy-two samples were collected over a one year period. Water temperature was the abiotic factor with the greatest influence on the distribution of the assemblage. The structure of the assemblage exhibited significant changes in terms of species abundance and biomass during the year, with the greatest abundance and biomass being observed during the autumn. There was no significant difference between day and night in terms of abundance, but biomass was significantly greater during the night than during the day.

Hatching and larval export of the intertidal crab Neohelice granulata in Mar Chiquita coastal lagoon, Argentina

Synchronization in the events of the reproductive cycle in female Neohelice granulata Dana, 1851 were studied from samples taken weekly and biweekly from September to December 2006 in the Laguna Mar Chiquita. The timing and larval hatching and synchronicity were inferred from numbers of ovigerous females and observing the stages of embryonic development. Synchronization in larval hatching also was observed in females in experiments in dark for a period of 48 hours, at three different salinities (10, 23 and 33 ppm). In addition plankton sampling were performed in order to study larval exportation at the field and its link to the tidal and light/dark cycles. We found that ovigerous females of N. granulata have a marked synchronization in embryonic development which results in that most of berried females are close to hatching within a period of maximum tidal range (days). Within this period, there is a synchronization of hatching at a time scale of hours, governed by environmental conditions. The salinity range used in this study (10-32‰) did not affect hatching synchronicity neither time to hatch. Hatching was synchronized according to endogenous rhythms governed mainly by the tidal cycle and secondarily by the breadth of it. It is also conditioned by the light-dark cycle through an exogenous cycle, so that the hatchings would occur mostly at night high tides.

Identificació de components inclusius en alguns centres escolars d'educació infantil i primària de la comarca d'Osona

The present essay –which is a pilot study conceived to continue the research in depth in the future- is based in a comparative analysis of educational practice between five different primary and pre-school teaching centres in Osona and the educational practice in inclusive educational centres. The essay introduces the objectives of the research and the theoretical and conceptual framework in which it is based (chapter 1) in relation with the main themes and expressions which are the purpose of the study: comprensivity, inclusive school and inclusive practice. The theoretical framework is linked to the principal regulations applied in our context. The study describes the instruments and procedure analysis describes the instruments and procedure analysis which have been designed and used for a qualitative methodological approach, together with the data obtained from the analysis of five teaching centres (chapter 2). The results from the research show that the practice done in the analised schools are not totally comparable to the ones in the inclusive environment. Notwithsanding, there are some similar points, although not totally coincident, like the fact that either the analysed schools or the ones with an inclusive approach show availability and interest in improving integration of all the pupils in the school, also the teachers work together in some aspects like, evaluation of pupils with special needs, objectives and contents and activities fort he specific kind of pupils with special needs parents and the majority of the analyzed schools, like those fallowing inclusive educational approaches, try the pupils with special needs to develop their acquisition within the ordinary class with adapted material. I think, these verifications, some of them close to inclusive educational practice, could constitute a starting point to analyse our model, in order to offer a common curriculum that could respect the different styles and rhythms of acquisition of all the pupils, so that promoting a more flexible and open schooling. In conclusion, the results of this analysis, although dues to its limits, they can not be generalized, they can help to find the necessary changes to bet for a qualitative education in a school for everyone.

Renal sodium handling and nighttime blood pressure.

Blood pressure follows a circadian rhythm with a physiologic 10% to 20% decrease during the night. There is now increasing evidence that a blunted decrease or an increase in nighttime blood pressure is associated with a greater prevalence of target organ damage and a faster disease progression in patients with chronic kidney diseases. Several factors contribute to the changes in nighttime blood pressure including changes in hormonal profiles such as variations in the activity of the renin-angiotensin and the sympathetic nervous systems. Recently, it was hypothesized that the absence of a blood pressure decrease during the nighttime (nondipping) is in fact a pressure-natriuresis mechanism enabling subjects with an impaired capacity to excrete sodium to remain in sodium balance. In this article, we review the clinical and epidemiologic data that tend to support this hypothesis. Moreover, we show that most, if not all, clinical conditions associated with an impaired dipping profile are diseases associated either with a low glomerular filtration rate and/or an impaired ability to excrete sodium. These observations would suggest that renal function, and most importantly the ability to eliminate sodium during the day, is indeed a key determinant of the circadian rhythm of blood pressure.

The pineal neurohormone melatonin and its physiologic opiatergic immunoregulatory role

The pineal gland functions as a neuroendocrine transducer that coordinate the organism response to changing environmental stimuli such as light and temperature. The main and best known pineal neurohormone is melatonin that is synthesized and released in a circadian fashion with a peak during the night darkness hours. We have recently reported that melatonin exerts important immuno regulatory functions. Here we describe the astonishing property of exogenous melatonin which is able to counteract completely the depressive effect of anxiety-restraint stress and/or of corticosterone on thymus weight, andibody production and antiviral responses. This effect seems to be mediated by antigen-activated T cells via an opiatergic mechanism.

Ambulatory blood pressure measurement and antihypertensive therapy.

The traditional basis for assessing the effect of antihypertensive therapy is the blood pressure reading taken by a physician. However, several recent trials have been designed to evaluate the blood pressure lowering effect of various therapeutic agents during the patients' normal daytime activities, using a portable, semi-automatic blood pressure recorder. The results have shown that in a given patient, blood pressure measured at the physician's office often differs greatly from that prevailing during the rest of the day. This is true both in treated and untreated hypertensive patients. The difference between office and ambulatory recorded pressures cannot be predicted from blood pressure levels measured by the physician. Therefore, a prospective study was carried out in patients with diastolic blood pressures that were uncontrolled at the physician's office despite antihypertensive therapy. The purpose was to evaluate the response of recorded ambulatory blood pressure to treatment adjustments aimed at reducing office blood pressure below a pre-set target level. Only patients with high ambulatory blood pressures at the outset appeared to benefit from further changes in therapy. Thus, ambulatory blood pressure monitoring can be used to identify those patients who remain hypertensive only when facing the physician, despite antihypertensive therapy. Ambulatory monitoring could thus help to evaluate the efficacy of antihypertensive therapy and allow individual treatment.

Nuclear receptor Rev-erb alpha (Nr1d1) functions in concert with Nr2e3 to regulate transcriptional networks in the retina.

The majority of diseases in the retina are caused by genetic mutations affecting the development and function of photoreceptor cells. The transcriptional networks directing these processes are regulated by genes such as nuclear hormone receptors. The nuclear hormone receptor gene Rev-erb alpha/Nr1d1 has been widely studied for its role in the circadian cycle and cell metabolism, however its role in the retina is unknown. In order to understand the role of Rev-erb alpha/Nr1d1 in the retina, we evaluated the effects of loss of Nr1d1 to the developing retina and its co-regulation with the photoreceptor-specific nuclear receptor gene Nr2e3 in the developing and mature retina. Knock-down of Nr1d1 expression in the developing retina results in pan-retinal spotting and reduced retinal function by electroretinogram. Our studies show that NR1D1 protein is co-expressed with NR2E3 in the outer neuroblastic layer of the developing mouse retina. In the adult retina, NR1D1 is expressed in the ganglion cell layer and is co-expressed with NR2E3 in the outer nuclear layer, within rods and cones. Several genes co-targeted by NR2E3 and NR1D1 were identified that include: Nr2c1, Recoverin, Rgr, Rarres2, Pde8a, and Nupr1. We examined the cyclic expression of Nr1d1 and Nr2e3 over a twenty-four hour period and observed that both nuclear receptors cycle in a similar manner. Taken together, these studies reveal a novel role for Nr1d1, in conjunction with its cofactor Nr2e3, in regulating transcriptional networks critical for photoreceptor development and function.