Antimicrobial resistance of Shiga toxin (verotoxin)-producing Escherichia coli O157:H7 and non-O157 strains isolated from humans, cattle, sheep and food in Spain

A total of 722 Shiga toxin-producing Escherichia coli (STEC) isolates recovered from humans, cattle, ovines and food during the period from 1992 to 1999 in Spain were examined to determine antimicrobial resistance profiles and their association with serotypes, phage types and virulence genes. Fifty-eight (41%) out of 141 STEC O157:H7 strains and 240 (41%) out of 581 non-O157 STEC strains showed resistance to at least one of the 26 antimicrobial agents tested. STEC O157:H7 showed a higher percentage of resistant strains recovered from bovine (53%) and beef meat (57%) than from human (23%) and ovine (20%) sources, whereas the highest prevalence of antimicrobial resistance in non-O157 STEC was found among isolates recovered from beef meat (55%) and human patients (47%). Sulfisoxazole (36%) had the most common antimicrobial resistance, followed by tetracycline (32%), streptomycin (29%), ampicillin (10%), trimethoprim (8%), cotrimoxazole (8%), chloramphenicol (7%), kanamycin (7%), piperacillin (6%), and neomycin (5%). The multiple resistance pattern most often observed was that of streptomycin, sulfisoxazole, and tetracycline. Ten (7%) STEC O157:H7 and 71 (12%) non-O157 strains were resistant to five or more antimicrobial agents. Most strains showing resistance to five or more antimicrobial agents belonged to serotypes O4:H4 (4 strains), O8:H21 (3 strains), O20:H19 (6 strains), O26:H11 (8 strains eae-beta1), O111:H- (3 strains eae-gamma2), O118:H- (2 strains eae-beta1), O118:H16 (5 strains eae-beta1), O128:H- (2 strains), O145:H8 or O145:H- (2 strains eae-gamma1), O157:H7 (10 strains eae-gamma1), O171:H25 (3 strains), O177:H11 (5 strains eae-beta1), ONT:H- (3 strains/1 eae-beta1) and ONT:H21 (2 strains). Interestingly, most of these serotypes, i.e., those indicated in bold) were found among human STEC strains isolated from patients with hemolytic uremic-syndrome (HUS) reported in previous studies. We also detected, among non-O157 strains, an association between a higher level of multiple resistance to antibiotics and the presence of the virulence genes eae and stx(1). Moreover, STEC O157:H7, showed an association between certain phage types, PT21/28 (90%), PT23 (75%), PT34 (75%), and PT2 (54%), with a higher number of resistant strains. We conclude that the high prevalence of antimicrobial resistance detected in our study is a source of concern, and cautious use of antibiotics in animals is highly recommended.     

Prenatal ontogenetic history of the principal neurons of the neocortex of the cat (Felis domestica) a golgi study

Summary The individual prenatal ontogenetic history of the horizontal neurons (the Cajal-Retzius cells) of layer I, the Martinotti neurons of layer VI, the pyramid-like neurons (the polymorphous or spindle cells) of layer VI, and the pyramidal neurons of layer V of the cat neocortex have been investigated. These neurons undergo, in the course of prenatal ontogenesis, a series of significant changes in their dendritic and axonic arborizations resulting in their complete structural transformation. Some of these changes have led to the appearance of new types of neurons quite different from the original in their morphological features as wells as in the territory of distribution of their axons. The horizontal neurons of layer I (superficial plexiform layer) come to assume the morphological characteristics of Cajal-Retzius cells late in prenatal ontogenesis. Also, the pyramid-like neurons of layer VI (deep plexiform layer) acquire the features of polymorphous (spindle) neurons of layer VI late in prenatal neocortical ontogenesis.Certainly, the resulting functional transformations that these neuronal changes cause are important and of great significance in the understanding of the organization of the mammalian neocortex. In the course of prenatal ontogenesis the following occur: the horizontal neurons of layer I lose their axonic connections with layer VI and acquire an increasing relevance in the structural organization of layer I; the pyramid-like neurons of layer VI lose their axonic and dendritic connections with layer I and undergo pronounced regressive changes in their dendritic and axonic arborizations; and the Martinotti neurons lose their axonic connections with layer I and also undergo regressive changes in their dendritic arborizations. In addition, the structural-functional interrelationships among these three neurons, which are quite prominent during early neocortical ontogenesis, fade away in the course of late prenatal ontogenesis and possibly disappear altogether by the time of birth in the cat. These three neurons are the basic neuronal elements of the early, precallosal organization (the primordial neocortical organization) of the mammalian neocortex. Phylogenetically, these three types of neurons are very old ones and have been described in the cerebral cortices of amphibians and reptiles. Therefore, it is not surprising that the early, precallosal organization of the mammalian neocortex should resemble the structural organization of the reptilian (general cortex) neocortex.It is postulated in this communication that these neuronal transformations are the result of a restructuring in the organization of the mammalian neocortex which follows the arrival of the callosal fibers and of a new type of corticipetal fibers at the pyramidal plate. this restructuring represents a transformation of the fibrillary-neuronal structure of the mammalian neocortex from its early, precallosal (reptilian) organization into a more distinctly mammalian one. The mammalian neocortical organization is characterized by the sequential maturation of several strata of true pyramidal neuronal systems. In the course of prenatal ontogenesis the fibrillar and neuronal elements of the early, precallosal neocortical organization lose progressively their relevance in the structural organization of the mammalian neocortex while the new pyramidal neuronal systems acquire an increasing relevance in it.Supported by Grant HD-03298 and by General Research Support Grant FR-05392 from the General Research Branch, National Institutes of Health.     

Encuesta nacional sobre valoración de la actividad de los médicos internos residentes en los servicios de urgencias españoles

Introduction

The care activity of internal resident doctors is common to practically all medical and surgical training programs; however, there are no national data available regarding the situation of this activity from the perspective of the resident. The present study has sought to collect the opinion of the resident internal physicians on the health care performance and the teaching character that links them to their corresponding emergency departments, in the following areas: overall training value, appreciation of the workload, characteristics of the morning rotation, supervision or tutoring, etc.

A functional survey of the enhancer activity of conserved non-coding sequences from vertebrate Iroquois cluster gene deserts

Recent studies of the genome architecture of vertebrates have uncovered two unforeseen aspects of its organization. First, large regions of the genome, called gene deserts, are devoid of protein-coding sequences and have no obvious biological role. Second, comparative genomics has highlighted the existence of an array of highly conserved non-coding regions (HCNRs) in all vertebrates. Most surprisingly, these structural features are strongly associated with genes that have essential functions during development. Among these, the vertebrate Iroquois (Irx) genes stand out on both fronts. Mammalian Irx genes are organized in two clusters (IrxA and IrxB) that span >1 Mb each with no other genes interspersed. Additionally, a large number of HCNRs exist within Irx clusters. We have systematically examined the enhancer activity of HCNRs from the IrxB cluster using transgenic Xenopus and zebrafish embryos. Most of these HCNRs are active in subdomains of endogenous Irx expression, and some are candidates to contain shared enhancers of neighboring genes, which could explain the evolutionary conservation of Irx clusters. Furthermore, HCNRs present in tetrapod IrxB but not in fish may be responsible for novel Irx expression domains that appeared after their divergence. Finally, we have performed a more detailed analysis on two IrxB ultraconserved non-coding regions (UCRs) duplicated in IrxA clusters in similar relative positions. These four regions share a core region highly conserved among all of them and drive expression in similar domains. However, inter-species conserved sequences surrounding the core, specific for each of these UCRs, are able to modulate their expression.     

B-1 cells are pivotal for in vivo inflammatory giant cell formation

The mechanisms that govern giant cell (GC) formation in inflammatory, neoplastic and physiologic conditions are far from being understood. Here, we demonstrate that B-1 cells are essential for foreign-body GC formation in the mouse. GCs were analysed on the surface of glass cover slips implanted into the subcutaneous tissue of the animals. It was demonstrated that GCs are almost absent on cover slips implanted into the subcutaneous tissue of BALB/c or CBA/N X-linked immunodeficient mice. As these animals do not have B-1 cells in the peritoneal cavity, they were reconstituted with B-1 cells obtained from cultures of adherent mouse peritoneal cells. Results showed that in B-1-reconstituted animals, the number of GCs on the implant surface surpassed the values obtained with preparations from wild animals. In animals selectively irradiated (pleural and peritoneal cavities) to deplete these cavities of B-1 cells, GCs were also not formed. Enriched suspensions of B-1 cells grown in culture were labelled with [(3)H]-tymidine and injected into the peritoneal cavity of naive mice before implantation of glass cover slips. After 4 days, about 17% of mononuclear cells had their nuclei labelled, and almost 70% of GCs had one or more of their nuclei labelled when analysed by histoautoradiographic technique. A few GCs expressed an immunoglobulin M when analysed by immunostaining and confocal microscopy. Overall, these data demonstrate that B-1 cells are pivotal in the mechanisms of foreign-body GC formation in the mouse.     

Heterogeneity of structural abnormalities in the 7q31.3 approximately q34 region in myeloid malignancies

Abnormalities in the long arm of chromosome 7 are a frequent chromosomal aberration in myeloid disorders. Most studies have focused on the analysis of del(7q), demonstrating the presence of several minimal deleted regions in 7q22 approximately q31. By contrast, few studies in myeloid disorders have been devoted to the analysis of translocations, either balanced or unbalanced, involving 7q. In this study, we used fluorescence in situ hybridization (FISH) to characterize the 7q31.3 approximately q34 region (markers D7S480-D7S2227) in patients with deletion or translocation of 7q. A total of 910 cases of myeloid disorders were studied by conventional cytogenetics. Fifty-eight (6%) patients had structural aberrations of 7q. FISH studies were carried out in the 27 patients with involvement of 7q31 approximately q34: 14 cases had an acute myelogenous leukemia and 13 cases had a myelodysplastic syndrome. FISH analysis revealed the existence of high complexity in the 7q31.3 approximately q34 region in patients with unbalanced translocations. No breakpoints in 7q31.3 approximately q34 were found in the cases with deletion or balanced translocation. Nevertheless, studies of unbalanced translocations showed several breakpoints in markers D7S480-D7S2227, which delineate a commonly altered region. The complexity of 7q rearrangements suggests that a synergy of different genetic factors, rather than the alteration of a single tumor suppressor gene, could be involved in the pathogenesis of del(7q) in myeloid disorders.     

Design and development of a digital stethoscope encapsulation for simultaneous acquisition of phonocardiography and electrocardiography signals: the SmartHeart case study

Abstract

The stethoscope is a major symbol of modern medicine. It is used for diagnosis of different conditions and enables physicians to listen to internal body sounds. Electrocardiography was only introduced in medicine in the beginning of the twentieth century. Today measuring heart’s electrical activity is also fundamental cardiac diseases diagnosis. Although performed with independent devices, requiring physician and patient presence in the same physical space, in combination they enhance cardiovascular assessment. In this paper, a digital stethoscope encapsulation was designed, adding new functionality to this advanced medical device. Today wired and wireless communications enable different medical devices to share data and information, over long distances. Using low-cost hardware technologies, the encapsulation will add the ability to acquire and transmit via Bluetooth the Electrocardiographic activity, determined in the same cardiac focus and synchronised with the Phonocardiographic sound recordings. Several encapsulation concepts were developed and prototyped using 3D printing. They were easily fitted to the digital stethoscope and tested in a hospital environment for ergonomics, acoustic and electric signals acquisition. The best concept was chosen with the help of a physician’s opinion and the final prototype performance was very satisfactory.