Transesophageal echocardiography-guided cardioversion of atrial fibrillation. Selection of a low-risk group for immediate cardioversion.

INTRODUCTION: In patients (pts) with atrial fibrillation (AF) of more than 48 hours' duration, electrical cardioversion (ECV) should only be performed after 3 weeks of effective anticoagulation. Transesophageal echocardiography (TEE) allows earlier ECV; however, despite exclusion of thrombi in the atrium and left atrial appendage (LAA), cases of thromboembolism related to ECV have been documented in AF. To define a low-risk group for cardioversion without previous anticoagulation, pts were selected for immediate ECV if no thrombi or dynamic spontaneous echo contrast (auto-contrast) were found after TEE and if LAA velocity was more than 0.25 m/sec. METHODS AND RESULTS: We performed TEE in 31 consecutive pts referred for ECV for AF of more than 48 hours' duration and without previous anticoagulation. After TEE the pts eligible for immediate ECV began anticoagulation with low molecular weight heparin (enoxaparin), subcutaneously in therapeutic doses, together with warfarin immediately before cardioversion. Enoxaparin was continued until an INR of over 2 was reached. Based on the TEE findings, the pts were divided in 2 groups: immediate ECV, group A, 20 pts with a mean age of 62 +/- 13 years, 6 female; and conventional therapy with warfarin before ECV, group B, 11 pts, mean age of 67 +/- 10 years (p < 0.05), 2 female. None of the pts in either group had mitral stenosis or previous episodes of thromboembolism. The mean transverse diameter of the left atrium in the 31 pts was 47 +/- 4.5 mm, without statistically significant differences between the 2 groups. Of the 11 pts in group B, 3 had a thrombus in the LAA, 6 dynamic spontaneous echo contrast and the remainder LAA velocities of less than 0.25 m/sec. ECV was achieved in all the pts, with no complications. Oral anticoagulation was maintained for at least a month. At one month, sinus rhythm was maintained in 75% of group A and 45% of group B (p < 0.01). CONCLUSION: In pts with AF of more than 48 hours' duration and no previous history of thromboembolism, the use of our exclusion criteria during TEE enabled stratification of a low-risk population for immediate ECV, which was accomplished effectively and safely in 2/3 of the pts. This strategy is associated with early symptomatic improvement, and may contribute to maintenance of sinus rhythm after one month, which was significantly better than in the pts who had prolonged therapy with warfarin before ECV, despite the differences found in age and left ventricular function.     

Crystallization and thermal behaviour of blends of isotactic polypropylene and hydrogenated oligo(cyclopentadiene)

The crystallization and the thermal behaviour of thin films of isotactic polypropylene/hydrogenated oligo(cyclopentadiene) of low molecular weight (iPP/HOCP) are studied using optical microscopy and differential scanning calorimetry (DSC). The spherulite growth rate, the overall crystallization rate and the equilibrium melting temperature of iPP are decreased by the addition of HOCP to iPP. This leads to the hypothesis that iPP and HOCP form a miscible blend in the amorphous phase. This hypothesis is also supported by the detection of a single blend-composition-dependent glass transition temperature of each blend as determined by DSC.     

Ultrastructural localization of human HL-A membrane antigens by use of hybrid antibodies

The localization of HL-A histocompatibility antigens at the surface of human lymphocytes in electron microscopy has been studied using hybrid antibodies to bind electron-dense particles (ferritin and plant viruses) to anti-HL-A antibody. A discontinuous distribution of the markers is observed at the cell surface, which is identical with that described for H-2 antigens on mouse lymphocytes with the same technique. Double labelling experiments suggest that the areas of the cell surface where HL-A antigens are detected contain also the heterologous lymphocyte antigens detected by an anti-thymocyte serum and that HL-A antigens are not renewed at a detectable level during the period of the labelling procedure in the areas of the cell surface which are not labelled primarily with ferritin-anti-IgG-anti-HL-A complexes. The interpretation of the discontinuous labelling of HL-A antigens with direct immunoferritin techniques is discussed.     

Prolonged waking reduces human immunodeficiency virus glycoprotein 120- or tumor necrosis factor alpha-induced apoptosis in the cerebral cortex of rats

The human immunodeficiency virus (HIV) induces neuronal death, presumably by apoptosis. This effect may be triggered by the glycoprotein 120 (HIVgp120) released by HIV when infecting a cell, and mediated by tumor necrosis factor alpha (TNF), a pro-inflammatory cytokine. Both molecules, HIVgp120 and TNF, increase sleep when administered acutely in the brain. On the other hand, sleep deprivation increases the levels of several growth factors. In this context, we challenged rats with HIVgp120 or TNF simultaneously with sleep deprivation. Our results indicate that both HIVgp120 and TNF increase neuronal death in the rat cerebral cortex, but not hippocampus, and that this effect is completely prevented by total deprivation of sleep. These results suggest that acute total deprivation of sleep protects against the HIVgp120 and TNF deleterious effects.     

Intramesosalpingeal injection of oxytocin in conservative laparoscopic treatment for tubal pregnancy: preliminary results

The objective of this study was to evaluate the efficacy of the local use of oxytocin as adjuvant treatment in conservative surgery for tubal pregnancy. The patients were 25 women with laparoscopic diagnosis of tubal pregnancy who were candidates for salpingotomy. Before salpingotomy, each patient was randomly allocated to intramesosalpingeal injection of 20 IU oxytocin diluted to 20 ml with saline solution or 20 ml saline solution. The surgeon then proceeded with salpingotomy and removal of the pregnancy according to the usual technique. The main outcome measures were bleeding during salpingotomy, ease of removal of the pregnancy, bleeding at the site of the pregnancy, and need for recourse to salpingectomy. Twelve women were randomized to the oxytocin group and 13 to the control group. Examination of the surgeons' assessments of the difficulties encountered at the different stages of surgery revealed statistically significant differences between the oxytocin group and controls in each variable. In particular, the amount of endosalpingeal bleeding after removal of the pregnancy was less in the oxytocin group. In one control patient, persistent bleeding due to incomplete trophoblast removal forced the surgeon to perform salpingectomy. Our results indicate that intramesosalpingeal injection of oxytocin facilitates the performance of conservative laparoscopic treatment for tubal pregnancy.      

Distributed controller design and performance optimization for discrete‐time linear systems

This article addresses the problem of distributed controller design for linear discrete‐time systems. The problem is posed using the classical framework of state feedback gain optimization over an infinite‐horizon quadratic cost, with an additional sparsity constraint on the gain matrix to model the distributed nature of the controller. An equivalent formulation is derived that consists in the optimization of the steady‐state solution of a matrix difference equation, and two algorithms for distributed gain computation are proposed based on it. The first method consists in a step‐by‐step optimization of said difference matrix equation, and allows for fast computation of stabilizing state feedback gains. The second algorithm optimizes the same matrix equation over a finite time window to approximate asymptotic behavior and thus minimize the infinite‐horizon quadratic cost. To assess the performance of the proposed solutions, simulation results are presented for the problem of distributed control of a quadruple‐tank process, as well as a version of that problem scaled up to 40 interconnected tanks.     

The income level and life styles: towards a law of inverse prevention?

The study of the determinants of disease-related lifestyles may be relevant for better understanding the potential of health policies. In the present work, results of the analysis of the Elche Healthy Cities Interview Survey prevalence of some disease related lifestyles (physical activity level, cigarette consumption, and alcohol intake) are presented according to economic level as measured by monthly family income, 573 people randomly selected from the town rolls were interviewed at home. No associations were found between economic level and alcohol intake or present smoking status. But, trying to stop smoking and regular exercise were more frequent behaviors in higher economic groups. The ratio of prevalence of regular exercise was 1.73 in favor of the highest economic levels. The gradient found was statistically significant (chi 2 for trend = 17.4, p less than 0.01). The results may be of relevance when implementing health policies to overcome inequalities in health: "unequal interventions" may be more adequate.     

Renal tubular acidosis in the Silver-Russell syndrome

Several patients with the Silver-Russell syndrome (SRS) attending our Genetics Clinic were diagnosed as having persistent metabolic acidosis. Since this abnormality has not been reported previously in the SRS, we reexamined 33 SRS patients to evaluate the frequency and type of metabolic acidosis, the clinical and laboratory findings, and the growth pattern in SRS patients with and without metabolic acidosis. Among them, 14 had a consistent decrease in HCO levels. Renal studies in acidotic patients showed urine pH of 5.8 and 24 h urine calcium of <2.4 mg/kg/24 h; serum creatinine, excretion of glucose, and aminoacids were normal, as were renal ultrasound and excretory urography findings. These data supported the diagnosis of renal tubular acidosis, probably type II; the patients were treated with oral bicarbonate and acidosis was corrected successfully. Clinical manifestations were similar in acidotic and non-acidotic patients. The nutritional indices at diagnosis and at last evaluation (at least 8 months after diagnosis) were abnormally low in all patients; however, acidotic patients, treated with bicarbonate, showed an improvement of nutritional status particularly in the weight/height index, although the difference between groups after follow-up did not reach statistical significance. We suggest that metabolic acidosis due to renal tubular acidosis, probably type II, may occur in children with the SRS and should be looked for and treated in all patients. © 1995 Wiley-Liss, Inc.     

Effects of rolipram on the elevated plus-maze test in rats: a preliminary study.

The objective of the present study was to assess the behavioural effects of rolipram, a specific cAMP phosphodiesterase (PDE4) inhibitor, in the elevated plus-maze (EPM) test in rats. Results showed that rolipram at the highest dose tested (0.1 mg/kg) increased the percentage of both time spent and entries into open arms, although a decrease of locomotor activity in the EPM test was also observed. In contrast, diazepam (3.0 mg/kg) exhibited the typical profile of an anxiolytic in the EPM test, increasing the percentage of time spent and entries into open arms as well as locomotor activity. A posterior statistical analysis, however, established that the effects of both rolipram and diazepam on parameters denoting anxiolytic-like activity were statistically independent from those reflecting locomotor activity reduction. Furthermore, the effects of both rolipram and diazepam were shown to be distinct from those exhibited by tricyclic antidepressant imipramine which did not show any anxiolytic-like effects in the EPM test, although a reduction of locomotor activity was also detected. Although these preliminary results suggest that rolipram may have some anxiolytic-like properties on the EPM test in rats, such an interpretation should be taken cautiously due to the observed effects on locomotor activity, which could complicate the interpretation of results from rolipram and other PDE4 inhibitors in the current test and in other anxiety animal models.