Relation Between Cellular Repolarization Characteristics and Critical Mass for Human Ventricular Fibrillation

INTRODUCTION: The critical mass for human ventricular fibrillation (VF) and its electrical determinants are unclear. The goal of this study was to evaluate the relationship between repolarization characteristics and critical mass for VF in diseased human cardiac tissues. METHODS AND RESULTS: Eight native hearts from transplant recipients were studied. The right ventricle was immediately excised, then perfused (n = 6) or superfused (n = 2) with Tyrode's solution at 36 degrees C. The action potential duration (APD) restitution curve was determined by an S1-S2 method. Programmed stimulation and burst pacing were used to induce VF. In 3 of 8 tissues, 10 microM cromakalim, an ATP-sensitive potassium channel opener, was added to the perfusate and the stimulation protocol repeated. Results show that, at baseline, VF did not occur either spontaneously or during rewarming, and it could not be induced by aggressive electrical stimulation in any tissue. The mean APD at 90% depolarization (APD90) at a cycle length of 600 msec was 227+/-49 msec, and the mean slope of the APD restitution curve was 0.22+/-0.08. Among the six tissues perfused, five were not treated with any antiarrhythmic agent. The weight of these five heart samples averaged 111+/-23 g (range 85 to 138). However, after cromakalim infusion, sustained VF (> 30 min in duration) was consistently induced. As compared with baseline in the same tissues, cromakalim shortened the APD90 from 243+/-32 msec to 55+/-18 msec (P < 0.001) and increased the maximum slope of the APD restitution curve from 0.24+/-0.11 to 1.43+/-0.10 (P < 0.01). CONCLUSION: At baseline, the critical mass for VF in diseased human hearts in vitro is > 111 g. However, the critical mass for VF can vary, as it can be reduced by shortening APD and increasing the slope of the APD restitution curve.     

PARANEOPLASTIC PEMPHIGOID-PEMPHIGUS? SUBEPIDERMAL BULLOUS DISEASE WITH PEMPHIGUS-LIKE DIRECT IMMUNOFLUORESCENCE

Background. Paraneoplastic pemphigus is a recently described variant of pemphigus, in which classic immunologic features of pemphigus are associated with subepidermal erythema multiforme-like bullae. Case Reports. Two patients with underlying malignant neoplasm had a bullous disease, which had clinical and histologic features suggestive of bullous pemphigoid while direct immunofluorescence revealed intercellular deposits of IgG and C3 throughout the malpighian layer of epidermis, a pattern usually diagnostic for pemphigus. Indirect immunofluorescence studies were negative. One mg/kg/day prednisone was enough to cure the eruption in a couple of weeks without any recurrence. Conclusions. The disease differs from the recently reported paraneoplastic pemphigus and from other bullous diseases associating circulating pemphigus-like antibodies with clinical, histologic, and often even immunologic features of bullous pemphigoid.     

Granulomatous hypersensitivity to Schistosoma mansoni EGG antigens in human schistosomiasis. IV. A role for prostaglandin-induced inhibition of in vitro granuloma formation

The prostaglandins (PG) are known to regulate immune cell function(s) and participate in the progression of both acute and chronic inflammatory reactions. Using an in vitro model of Schistosoma mansoni egg-induced hypersensitivity granulomas, we have delineated the role of immune complexes (IC) in the induction and release of PG and their inhibitory effects on granuloma development. The hypersensitivity-type granuloma reaction to soluble egg antigen (SEA) was examined using a model of in vitro granuloma formation. Our results show that granuloma formation was dramatically suppressed by the addition to the granuloma cultures of IC, PGE¹, PGE², while PGF₂ alpha had no significant effect. The inhibition of the PG function was achieved by the introduction of anti-PG antibodies that blocked suppression of granuloma formation. It appears in this model system that IC may inhibit the activity of granuloma formation by stimulating the monocyte-macrophage lineage to release inhibitory mediators. Our results suggest that the prostaglandins E series may be important in the generation and maintenance of suppression of the granulomatous inflammatory response to S. mansoni egg antigens.     

Conformation and dynamics of the chemotactic peptide formyl-L-methionyl-L-leucyl-L-phenylalanine in solution

Several conformational and dynamic features of the chemotactic peptide formyl-L-methionyl-L-leucyl-L-phenylalanine in solution have been delineated by investigations of NMR and IR spectroscopic parameters. Both 1D and 2D NMR experiments have been performed for detection of scalar and dipolar proton-proton connectivities, whereas ¹³C and ¹H relaxation parameters have been interpreted in terms of molecular dynamics. The main conformation appeared to be unfolded with the three hydrophobic side chains extending in divergent directions with respect to the backbone. The existence of relatively weak inter-molecular hydrogen bonds was demonstrated, involving the formamide end group, with increase in the hydrophobicity of the external surface.     

BLASTOMYCOSIS-LIKE PYODERMA (PYODERMA VEGETANS) RESPONDING TO ANTIBIOTICS AND TOPICAL DISODIUM CHROMOGLYCATE

Background. Blastomycosis-like pyoderma is a disorder of uncertain etiology that has been described in association with a variety of underlying conditions, including inflammatory and neoplastic pathologic conditions and in association with a primary immunodeficiency state. The response to therapy, antibiotics in particular, is said to be variable or poor. Methods. We examined two patients with blastomycosis-like pyoderma in whom no underlying pathologic or immunologic abnormalities were found. We treated them with antibiotics according to bacterial resistance tests. In the second case topical disodium chromoglycate was added. Results. Treatment cleared or markedly improved the lesions. Conclusions. Antibiotic treatment guided by susceptibility tests is recommended. The addition of topical disodium chromoglycate may be useful.     

Evaluation of Postinfarction Viable Myocardium at Jeopardy by Dobutamine Echocardiography and Myocardial Contrast Echocardiography

Both myocardial contrast echocardiography (MCE), obtained by intracoronary injection of sonicated Ioxaglate, and dobutamine echocardiography (DE) were performed before and after percutaneous transluminal coronary angioplasty (PTCA) in a patient with recent myocardial infarction, an occluded infarct related artery (IRA) and collateral flow. An opposite response to low and high dose dobutamine (increase and decrease in regional contractility, respectively) suggested the presence of viable myocardium at jeopardy in the infarcted area. This myocardial area was exclusively perfused by collateral circulation (demonstrated by MCE) supplied by an angiographically normal left coronary artery. After PTCA, right coronary artery flow was re-established and angiographically demonstrated collateral flow disappeared. MCE showed a normal right coronary artery perfusion bed and relevant overlap areas after left coronary MCE injection. Dobutamine echocardiography performed after PTCA demonstrated persistence of viability, but disappearence of myocardial ischemia.     

Carcinoembryonic Antigen as a Monitor in Breast Cancer

ABSTRACT: Carcinoembryonic antigen (CEA) levels were serially determined in 125 patients with breast cancer in order to study the diagnostic and prognostic use of serum CEA levels before and/or after surgery and during treatment with hormonal and chemotherapy. Serum CEA levels were elevated in 15.5% of nonmetastatic patients. Carcinoembryonic antigen increased according to stage (TNM classification); and a direct relationship between positive CEA levels and subsequent recurrence was found. After a three-year postoperative interval a 50% survival rate was exhibited in CEA-positive patients vs an 88% survival rate in those patients found to be CEA negative. There is a definite correlation between the trend of serial CEA values and the response to therapy and the development of metastases despite the fact that metastases occurred in CEA-negative patients. Therefore CEA assay is a useful and simple adjuvant test of monitoring metastatic and nonmetastatic breast cancer.     

A population survey of bowel habits in urban Swiss men

The aim of this study was to determine the prevalence of symptomsrelated to constipation in urban Swiss men and to identify associatedsociodemographic factors and health habits. A sample of 773men aged between 35 and 74 years randomly selected from theGeneva population answered a questionnaire on bowel habits duringa personal interview in a mobile epidemiological unit. ‘Constipation’was reported by more than 6% of subjects, difficulties in stoolevacuation by approximately 5% and less than three stools perweek by approximately 2%. These symptoms appeared less prevalentin subjects with post-baccalaureate education (the excess prevalenceof self-reported constipation, difficulty in stool evacuationand frequent daily defecation was greater than 5%). Smokerswere more likely to have a frequency of 3–7 stools perweek and were less affected by frequent daily defecation. Self-reportedconstipation was more prevalent in subjects with a higher dietaryfibre intake. No statistically significant effects of age, nationality,dietary fat or physical activity were observed. These resultsare consistent with national surveys in US populations. Factorsrelated to socioeconomic status or education may be a causeof constipation in men, but they still need to be elucidated.     

Syntactic comprehension in Broca's aphasic Spanish-speakers: null effects of word order

The syntactic and nonsyntactic strategies used for understanding sentences by Spanish-speaking Broca's aphasic patients in off-line tasks were analysed. It is emphasized that given the characteristics of syntax in Spanish, such as its flexibility (greater freedom in the order of constituents), the function of the direct object with the preposition a (to) and the effect of determiners, research with Spanish-speaking patients will allow for a characterization of specific disorders that cannot be generalized on the basis of research conducted in other languages. A linguistic instrument was applied to 10 Broca's aphasic patients. A forced choice task was used in which the patient listened to 190 different reversible sentences and was asked to select one of four options presented on a plate; each option contained a pair of animals performing a specific act and only one option was correct. The results showed significant differences in the use of syntactic and nonsyntactic strategies. Broca's aphasic patients used only morpho-syntactic marks with high cue validity. No significant effects of word order were found. These findings imply the existence of specific off-line linguistic mechanisms that influence the comprehension in non-fluent aphasic patients.