Comparison of clinical and echocardiographic characteristics of Streptococcus bovis endocarditis with that caused by other pathogens.

The aim of our study was to compare the clinical, echographic, and prognostic features of Streptococcus bovis (S. bovis) endocarditis with those caused by other streptococci and pathogens in a large sample of patients with definite endocarditis by Duke criteria, using transesophageal echocardiography. Two hundred six patients (149 men, mean age 57 +/- 15 years) with a diagnosis of infective endocarditis formed the study population. All patients underwent multiplane transesophageal echocardiography and blood cultures. Cerebral, thoracoabdominal computed tomographic scan was performed in almost all patients (95%). All patients with S. bovis endocarditis underwent colonoscopy. Incidence of S. bovis endocarditis in our sample was 19%. Patients with S. bovis endocarditis were older than other groups. Multiple valve involvement, native valves, and large vegetations (>10 mm) were more frequent in patients with S. bovis. There was a significantly higher occurrence of embolism in the S. bovis group. Splenic embolism and multiple embolisms were significantly more frequent in patients with S. bovis. Gastrointestinal lesions, anemia, and spondylitis were observed more frequently with S. bovis endocarditis. In addition to the requirement for gastrointestinal examination for S. bovis endocarditis, our study underlines the need for systematic screening for vertebral and splenic localizations, and suggests the use of early surgery to prevent the high risk of embolism in these patients.     

Posterior reversible encephalopathy syndrome associated with Guillain-Barré syndrome: Case report and clinical management considerations

Around half of the patients with Guillain-Barré syndrome (GBS) present autonomic dysfunction requiring admission to intensive care unit in up to a quarter of patients. Treatment of GBS consists of plasma exchange (PE) and intravenous immunoglobulins (IVIG). Posterior reversible encephalopathy syndrome (PRES) consists in a reversible subcortical vasogenic brain edema caused by endothelial damage triggered by abrupt blood pressure changes. We report on a woman who presented with PRES in the course of GBS treated first with IVIG, and then with PE. The present report underlines the challenge that the clinicians face when these two rare syndromes concur. The literature is not helpful considering that both blood pressure fluctuations and IVIG are reported to be involved in the pathogenesis of PRES. In the present letter, both pathogenic mechanisms and clinical management considerations are discussed.     

Bladder spectrophotometry after intravesical Epirubicine instillations: Evaluation of future possibilities of topical bladder sensitization for PDT

Topical instillations with Epirubicine were performed in vivo in patients with macroscopically visible tumours. Within 8 h Epirubicine fluorescence could be detected in normal mucosa. After 60 to 72 h no fluorescence was detected in normal mucosa but could still be found in tumour areas, though not at a constant time interval.It is suggested that photosensitizers could be used topically provided that they are not only tumour specific but also time specific.     

Evoked potentials (EPs) in experimental allergic encephalomyelitis: a study of EP modifications during the course of a controlled disease.

24 juvenile strain 13 guinea pigs were sensitized with homologous spinal cord homogenate in complete Freund's adjuvant in order to obtain Experimental Allergic Encephalomyelitis (EAE) in the Chronic Relapsing (CR-EAE), Chronic Progressive (CP-EAE) and Acute (A-EAE) forms. Visual, Brain-Stem Acoustic, Somatosensory Evoked Potentials were recorded in these animals, prior to the sensitizing injection and during the course of the disease. The aim of our study was to observe modifications of Evoked Potentials during progression of a demyelinating disease. Latency delays of Evoked Potentials appeared 15 days after the sensitizing injection, preceding or simultaneously with clinical alterations and when demyelinated plaques were not detected in anatomical specimens.     

Validation of quantitative parameters of paraprosthetic mitral valve regurgitation of the zone of convergence by transthoracic echocardiography

The study of the convergence zone by echocardiography is a validated method of quantification of native valve mitral regurgitation. However, there is little data concerning its applications to paraprosthetic mitral regurgitation. The aim of this study was to evaluate the method in this indication. Thirty consecutive patients (21 mechanical and 9 bioprostheses) with paraprosthetic mitral regurgitation quantified by transoesophageal echocardiography were included: 4 mild, 13 moderate and 13 severe. The regurgitant volume RV) and the regurgitant surface area (RSA) were calculated by the following formulae: RV = 2 pi.r2.Va.t.alpha/180 and RSA = RV/VTI (r: mid systolic radius of the convergence zone, Va: aliasing velocity, t: regurgitation time, alpha/180: the angular correction due to parietal stress, VTI: velocity time integral of the regurgitant flow). The feasibility of the calculation of the RV and RSA was 93 and 63% respectively. There was a statistically significant correlation between the RV and transoesophageal echocardiography (r: 0.85, p < 0.001), between RSA and transoesophageal echocardiography (r: 0.67, p < 0.05) and between RV and RSA (r: 0.95, p < 0.001). When severe paraprosthetic regurgitation was defined by a RV greater than 60 ml and RSA greater than 40 mm2, the concordance between RV, RSA and transoesophageal echocardiography was 75% and 74% respectively. Therefore, the study of the convergence zone provides an accurate evaluation of paraprosthetic mitral regurgitation by transthoracic echocardiography.     

Recognition of peptide-MHC class I complexes by activating killer immunoglobulin-like receptors

Inhibitory receptors for MHC class I molecules increase the threshold of lymphocyte activation. Natural Killer (NK) cells express a large number of such inhibitory receptors, including the human killer Ig-like receptors (KIR). However, activating members of the KIR family have poorly defined ligands and functions. Here we describe the use of activating KIR tetramer reagents as probes to detect their ligands. Infection of cells with Epstein-Barr virus leads to expression of a detectable ligand for the activating receptor KIR2DS1. In this case, KIR2DS1 interacts with up-regulated peptide-MHC class I complexes on Epstein-Barr virus-infected cells in a transporter associated with antigen processing (TAP)-dependent manner. In tetramer-based cellular assays and direct affinity measurements, this interaction with MHC class I is facilitated by a broad spectrum of peptides. KIR2DS1 and its inhibitory homologue, KIR2DL1, share sensitivity to peptide sequence alterations at positions 7 and 8. These results fit a model in which activating and inhibitory receptors recognize the same sets of self-MHC class I molecules, differing only in their binding affinities. Importantly, KIR2DS1 is not always sufficient to trigger NK effector responses when faced with cognate ligand, consistent with fine control during NK cell activation. We discuss how our results for KIR2DS1 and parallel studies on KIR2DS2 relate to the association between activating KIR genes and susceptibility to autoimmune disorders.