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)

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.

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.

Tryptophan metabolism in tsetse flies and the consequences of its derangement

Literature comparing salmon and wild type Glossina morsitans morsitans and that comparing tan and wild type Glossina palpalis palpalis is reviewed. New information is presented on behaviour and biochemistry of salmon and wild type G. m. morsitans. The eye color mutants result from two lesions in the tryptophan to xanthommatin pathway: lack of tryptophan oxygenase in G. m morsitans and failure to produce or retain xanthommatin in eyes (but not in testes) of G. p. palpalis. The salmon allele in G. m. morsitans is pleiotropic and profoundly affects many aspects of fly biology including longevity, reproductive capacity, vision, vectorial capacity and duration of flight, but not circadian rhythms. The tan allele in G. p. palpalis has little effect upon the biology of flies under laboratory conditions, except that tan flies appear less active than normal. Adult tsetse flies metabolize tryptophan to kynurenine which is excreted; fluctuations in activities of the enzymes producing kynurenine suggest this pathway is under metabolic control.

Influence of experimental illumination and seasonal variation on crossbreending mating in the snail Biomphalaria Glabrata

The crossbreeding activities of the Schistosoma mansoni vector snail Biomphalaria glabrata were counted in a laboratory aquarium throughout the year under two regimes of 12h light: 12h dark from 7 A., M. to 10 P. M. Mating increased significantly in Authmn and Winter and just missed a significant inverse correlation with temperature and a direct one with locomotion. Other similar experiments were carried out to compare mating under various ilumination conditions in complete daily cycle measurements. Mating counts decreased under the regimes which submited snail to a total exposure of 12h light and 12 dark during a daily cycle in the following sequence: 12h light: 12h dark alternating hourly with light gradient, 12h light: 12h dark, 1h light: 1h dark and 12h dark: 12h light. Under two constant illuminations, the mating scored less than under the previous conditions, except under 12h light. Under darkeness the mating count was lower than light conditions. There was no way to differentiate the night and day rhythms of mating on different days in each regime, except for mating under 12h light: 12 dark alternating with light gradient, constant dark and 12h dark: 12h light conditions. Mating increased in certain light and temperature conditions, in wich the intensities, should have an optimum value.

T-type Ca2+ channels, SK2 channels and SERCAs gate sleep-related oscillations in thalamic dendrites.

T-type Ca2+ channels (T channels) underlie rhythmic burst discharges during neuronal oscillations that are typical during sleep. However, the Ca2+-dependent effectors that are selectively regulated by T currents remain unknown. We found that, in dendrites of nucleus reticularis thalami (nRt), intracellular Ca2+ concentration increases were dominated by Ca2+ influx through T channels and shaped rhythmic bursting via competition between Ca2+-dependent small-conductance (SK)-type K+ channels and Ca2+ uptake pumps. Oscillatory bursting was initiated via selective activation of dendritically located SK2 channels, whereas Ca2+ sequestration by sarco/endoplasmic reticulum Ca2+-ATPases (SERCAs) and cumulative T channel inactivation dampened oscillations. Sk2-/- (also known as Kcnn2) mice lacked cellular oscillations, showed a greater than threefold reduction in low-frequency rhythms in the electroencephalogram of non-rapid-eye-movement sleep and had disrupted sleep. Thus, the interplay of T channels, SK2 channels and SERCAs in nRt dendrites comprises a specialized Ca2+ signaling triad to regulate oscillatory dynamics related to sleep.

A role for clock genes in sleep homeostasis.

The timing and quality of both sleep and wakefulness are thought to be regulated by the interaction of two processes. One of these two processes keeps track of the prior sleep-wake history and controls the homeostatic need for sleep while the other sets the time-of-day that sleep preferably occurs. The molecular pathways underlying the latter, circadian process have been studied in detail and their key role in physiological time-keeping has been well established. Analyses of sleep in mice and flies lacking core circadian clock gene proteins have demonstrated, however, that besides disrupting circadian rhythms, also sleep homeostatic processes were affected. Subsequent studies revealed that sleep loss alters both the mRNA levels and the specific DNA-binding of the key circadian transcriptional regulators to their target sequences in the mouse brain. The fact that sleep loss impinges on the very core of the molecular circadian circuitry might explain why both inadequate sleep and disrupted circadian rhythms can similarly lead to metabolic pathology. The evidence for a role for clock genes in sleep homeostasis will be reviewed here.

Thérapie cognitive et comportementale pour les hallucinations auditives résistantes au traitement neuroleptique

The aim of this study is to test the feasibility and the efficacy of a cognitive and behavior therapy manual for auditory hallucinations with persons suffering from schizophrenia in a French-speaking environment and under natural clinical conditions. Eight patients met ICD-10 criteria for paranoid schizophrenia, 2 for hebephrenic schizophrenia and 1 for schizoaffective disorder. All were hearing voices daily. Patients followed the intervention for 3 to 6 months according to their individual rhythms. Participants filled up questionnaires at pre-test, post-test and three months follow-up. The instruments were the Belief About Voice Questionnaire--Revised and two seven points scales about frequency of hallucinations and attribution of the source of the voices. Results show a decrease of voices' frequency and improvement in attributing the voices rather to an internal than to an external source. Malevolent or benevolent beliefs about voices are significantly decreased at follow-up as well as efforts at coping with hallucinations. Results should be interpreted with caution because of the small number of subjects. The sample may not be representative of patients with persistent symptoms since there is an over representation of patients with benevolent voices and an under representation of patients with substance misuse

Seasonal distribution and diel biting patterns of culicine mosquitoes in Costa Marques, Rondônia, Brazil

A study of peridomestic man-biting culicines in the Amazon Basin was conducted from January through December, 1987. Fifteen species of mosquitoes from six genera were collected by volunters in all-night human-bait indoor and outdoor collections at five hoses in and near the town of Costa Marques, Rondônia, Brazil. Culex quinquefasciatus and members of the Mansonia titillans/indubitans Group comprised 61 and 33%, respectively, of all culcines collected from human-bait outside houses and 62 and 35%, respectively, of those collected from volunteers inside houses in the town. In rural areas, Cx. quinquefasciatus was less abundant and only comprised 2 and 5% of the culcines, respectively, collected inside and outside houses. Mansonia titillans/indubitans Group comprised 75% and 86% of the culicines collected inside and outside houses, respectively, from rural residences. Culex quinquefasciatus and members of Mn. titillans/indubitans Group were more endophilic than other culcines collected. Nocturnal and seasonal biting rhythms for the more common culcines are described

Crosstalk between xenobiotics metabolism and circadian clock.

Many aspects of physiology and behavior in organisms from bacteria to man are subjected to circadian regulation. Indeed, the major function of the circadian clock consists in the adaptation of physiology to daily environmental change and the accompanying stresses such as exposition to UV-light and food-contained toxic compounds. In this way, most aspects of xenobiotic detoxification are subjected to circadian regulation. These phenomena are now considered as the molecular basis for the time-dependence of drug toxicities and efficacy. However, there is now evidences that these toxic compounds can, in turn, regulate circadian gene expression and thus influence circadian rhythms. As food seems to be the major regulator of peripheral clock, the possibility that food-contained toxic compounds participate in the entrainment of the clock will be discussed.

Quantitative genetics of sleep in inbred mice.

The timing and the organization of sleep architecture are mainly controlled by the circadian system, while sleep need and intensity are regulated by a homeostatic process. How independent these two systems are in regulating sleep is not well understood. In contrast to the impressive progress in the molecular genetics of circadian rhythms, little is known about the molecular basis of sleep. Nevertheless, as summarized here, phenotypic dissection of sleep into its most basic aspects can be used to identify both the single major genes and small effect quantitative trait loci involved. Although experimental models such as the mouse are more readily amenable to genetic analysis of sleep, similar approaches can be applied to humans.

Laboratory indicators for monitoring HIV disease

Immunological monitoring of disease progression following HIV infection and seroconversion illness, latency and AIDS, not only helps in the basic investigation of the natural history of the viral infection in man, but also can assist in prognosis and treatment of AIDS-defining illnesses. However, outside clinical trials, these tests should be selected and used in clinical practice only if they are validated as relevant and effective. The absolute CD4+ T-helper lymphocyte count, measured by flow cytometry, has emerged as the best available investigation, but needs care in sampling due to diurnal and circadian rhythms, effects of age, pregnancy, therapy, intercurrent infections and technique. Sampling should provide a baseline and trends - monthly intervals initially, then quarterly in uncomplicated cases. Thresholds may be given for counts (e.g. 200/µl) below which prophylaxis against pneumocystis pneumonia should be administered, and repeating persistently low counts (e.g. below 50/µl) is seldom helpful in practice. Serum levels of beta-2 microglobulin, neopterin and immunoglobulins rarely add information. Physicians and laboratories should have testing guidelines based on clinical audit of best practice, based in turn on scientific understanding of the immunological processes involved.