Hypertension pulmonaire associée aux maladies du coeur gauche: quelle définition et quelle prise en charge en 2013 [Pulmonary hypertension in left heart disease: how to define it and how to manage it in 2013?].

Pulmonary hypertension is a frequent complication of left heart disease arising from a wide range of cardiac disorders and is associated with poor prognosis. Its pathophysiology is complex with both passive mechanisms of elevated filling pressures in left cavities and occasionally reactive mechanisms of arterial vasoconstriction and remodelling to interplay. This stage, called <out-of-proportions> pulmonary hypertension, further worsens the heart failure patients' prognosis but is still a matter of debate concerning the criteria to apply for its diagnosis and concerning the best way to manage it. This article gives an overview of the importance and pathophysiology of pulmonary hypertension associated with left heart disease, and discusses the challenges associated with its diagnosis and treatment.

Present aspects of immunodiagnosis of schistosomiasis

Facilitated and improved by advances in molecular biology, techniques for the immunodiagnosis of schistosomiasis, including assays based on the detection of antigens circulating in the serum and/or excreted in the urine, have now reached the stage of multi-centre trials. There is a need to complement parasitological techniques as some national programmes are becoming increasingly succesful in establishng control of the disease and the classical approach frequently fails to reveal low-intensity infection. Epidemiological survey teams in some areas have tentatively started to use serology and their experience indicates that antibody detection suffies in eradicated or controlled areas with low expected prevalence but that detection of circulating antigens is needed for assessment of the incidence of infection or reinfection in areas recently brought under control. Before reagents and procedures can be recommended for routine use of national control programmes, the assays must be standardized with sera from clinically well-characterized patients in geographically defined regions, hence emphasizing the need for a reference serum bank. Implementation of serological testing, carried out by nationsl public health laboratories using standardized testing systems, would permit valid comparisons between different areas providing support for decisions regarding national health polices.

Origen de la multicel·lularitat : una aproximació genòmica i funcional

En el present estudi s'analitza l'origen i evolució de 2 molècules claus pera entendre la multicel·lularitat dels animals: les molècules d'adhesió integrines i els factors de transcripció T-box. S’utilitzen els genomes recentment publicats de protists unicel•lulars parents propers dels animals. S’analitza l’origen i evolució d’aquests gens mitjançant anàlisi filogènic, determinació de motius funcionals i també tècniques de biologia molecular. A més, es documenta un cas de transferència gènica horitzontal des d'un eucariota cap a un procariota, fenomen poc habitual. Les principals conclusions són que tant l’adhesoma d'integrina com els gens T-box tenen un origen molt anterior als animals, en un context unicel•lular, i que després foren cooptats pel llinatge multicel•lular dels animals.

Thrombolyse de l'accident vasculaire cérébral ischémique aigu: rôles du praticien et de l'hôpital périphérique [Thrombolysis of acute ischemic cerebral vascular accident: roles of the physician and the peripheral hospital]

Thrombolysis administered intravenously within 3 hours (or within 6 hours intra-arterially) after symptoms onset improves the functional outcome of acute ischemic stroke patients. In Switzerland this treatment is only performed by specialized centers. At the level of a community hospital or a general practitioner, the management is based on the appropriate selection of patients in whom thrombolysis could be indicated, followed by their immediate transfer to a reference medical center. Because of the very short therapeutic window, specific criteria have to be used. We present the guidelines of Les Cadolles Hospital in Neuchâtel established in collaboration with the Department of Neurology of the University Hospital of Lausanne and a retrospective analysis of emergency admissions for suspected stroke at Les Cadolles between January 1st 2001 and December 31st 2002.

Genetic variability and identification of the intermediate snail hosts of Schistosoma mansoni

Studies based on shell or reproductive organ morphology and genetic considerations suggest extensive intraspecific variation in Biomphalaria snails. The high variability at the morphological and genetic levels, as well as the small size of some specimens and similarities between species complicate the correct identification of these snails. Here we review our work using methods based on polymerase chain reaction (PCR) amplification for analysis of genetic variation and identification of Biomphalaria snails from Brazil, Argentina, Uruguay and Paraguay. Arbitrarily primed-PCR revealed that the genome of B. glabrata exihibits a remarkable degree of intraespecific polymorphism. Low stringency-PCR using primers for 18S rRNA permited the identification of B. glabrata, B. tenagophila and B. occidentalis. The study of individuals obtained from geographically distinct populations exhibits significant intraspecific DNA polymorphism, however specimens from the same species, exhibit some species specific LSPs. We also showed that PCR-restriction fragment of length polymorphism of the internal transcribed spacer region of Biomphalaria rDNA, using DdeI permits the differentiation of the three intermediate hosts of Schistosoma mansoni. The molecular biological techniques used in our studies are very useful for the generation of new knowledge concerning the systematics and population genetics of Biomphalaria snails.

Improved Methods for the Diagnosis of African Trypanosomosis

The diagnosis of trypanosomosis in animals with low parasitaemia is hampered by low diagnostic sensitivity of traditional detection methods. An immunodiagnostic method based on a direct sandwich enzyme-linked immunosorbent assay (ELISA), using monoclonal antibodies, has been examined in a number of African laboratories for its suitability for monitoring tsetse control and eradication programmes. Generally, the direct sandwich ELISAs for the detection of trypanosomal antigens in serum samples have proved to be unsatisfactory with respect to diagnostic sensitivity when compared with traditional parasitological methods such as the dark ground/phase contrast buffy-coat technique. Consequently, antigen-detection systems exploiting various other direct, indirect and sandwich ELISA systems and sets of reagents are being developed to improve diagnosis. In addition, an existing indirect ELISA for the detection of antibodies has been improved and is being evaluated in the field in order to detect cattle that are or have been recently infected with trypanosomes. Developments and advantages of other diagnostic techniques, such as dip-stick assay and tests based on the polymerase chain reaction are also considered.

Regulation of horizontal gene transfer of the catabolic island ICEclc

ICEclc is a mobile genetic element found in two copies on the chromosome of the bacterium Pseudomonas knackmussii B13. ICEclc harbors genes encoding metabolic pathways for the degradation of chlorocatechols (CLC) and 2-aminophenol (2AP). At low frequencies, ICEclc excises from the chromosome, closes into a circular DNA molecule which can transfer to another bacterium via conjugation. Once in the recipient cell, ICEclc can reintegrate into the chromosome by site-specific recombination. This thesis aimed at identifying the regulatory network underlying the decisions for ICEclc horizontal transfer (HGT). The first chapter is an introduction on integrative and conjugative elements (ICEs) more in general, of which ICEclc is one example. In particular I emphasized the current knowledge of regulation and conjugation machineries of the different classes of ICE. In the second chapter, I describe a transcriptional analysis using microarrays and other experiments to understand expression of ICEclc in exponential and stationary phase. By overlaying transcriptomic profiles with Northern hybridizations and RT- PCR data, we established a transcription map for the entire core region of ICEclc, a region assumed to encode the ICE conjugation process. We also demonstrated how transcription of the ICEclc core is maximal in stationary phase, which correlates to expression of reporter genes fused to key ICEclc promoters. In the third chapter, I present a transcriptome analysis of ICEclc in a variety of different host species, in order to explore whether there are species-specific differences. In the fourth chapter, I focus on the role of a curious ICEclc-encoded TetR-type transcriptional repressor. We find that this gene, which we name mfsR, not only controls its own expression but that of a set of genes for a putative multi-drug efflux pump (mfsABC) as well. By using a combination of biochemical and molecular biology techniques, I could show that MfsR specifically binds to operator boxes in two ICEclc promoters (PmfsR and PmfsA), inhibiting the transcription of both the mfsR and mfsABC-orf38184 operons. Although we could not detect a clear phenotype of an mfsABC deletion, we discuss the implications of pump gene reorganizations in ICEclc and close relatives. In the fifth chapter, we find that mfsR not only controls its own expression and that of the mfsABC operon, but is also indirectly controlling ICEclc transfer. Using gene deletions, microarrays, transfer assays and microscopy-based reporter fusions, we demonstrate that mfsR actually controls a small operon of three regulatory genes. The last gene of this mfsR operon, orf17162, encodes a LysR-type activator that when deleted strongly impairs ICEclc transfer. Interestingly, deletion of mfsR leads to transfer competence in almost all cells, thereby overruling the bistability process in the wild-type. In the final sixth chapter, I discuss the relevance of the present thesis and the resulting perspectives for future studies.

Typing and susceptibility to penicillin of Neisseria meningitidis isolated from patients in Cuba (1993-1999)

The susceptibility to penicillin of 111 Neisseria meningitidis strains was assessed by the agar-dilution procedure and serosubtypes were determined by a whole-cell enzyme-linked immunoassay using monoclonal antibodies reagents. Thirty-five isolates showed reduced sensitivity to penicillin (MIC > or = 0.1 mg/l and <= 1 mg/l) and no resistant strains were detected. The most common phenotype was B:4:P1.15 (77.5%) and a rising trend of non-typeable and non-subtypeable strains was detected. The increase in levels of minimal inhibitory concentrations of meningococci to penicillin gives cause for concern and the increase in non-typeable and non-subtypeable isolation demand the use of molecular biology techniques for their typing.

Schistosomiasis epidemiology and control: how did we get here and where should we go?

Although a disease of great antiquity, scientific studies of schistosomiasis began only 150 years ago. The complete life-cycle was not described until just before the First World War, making it possible at last to plan proper community control programmes. Inadequate tools prevented their effective implementation until well after the Second World War when new tools became available, thanks to the newly formed World Health Organization. Molluscicides spearheaded control programmes until the late 1970s but were then replaced by the newly developed, safe drugs still used today. Whatever the method used, the initial goal of eradication was, in the light of experience and cost, gradually replaced by less ambitious targets; first to stop transmission and then to reduce morbidity. The most successful programmes combined several methods to minimise reinfection after chemotherapy. Comparisons between different programmes are difficult without using appropriate, standardised diagnostic techniques and the correct epidemiological measurements. Some examples will be presented, mainly from our studies on Schistosoma mansoni in Kenya. Drug resistance on a scale comparable with malaria has not occurred in schistosomiasis but the likely withdrawal of all drugs except praziquantel leaves its control extremely vulnerable to this potential problem. An effective, affordable vaccine for use in endemic countries is unlikely to be ready for at least 5 years, and developing strategies for its use could take a further decade or more, judging from experience with drugs and molluscicides. In the interim, by analogy with malaria, the most cost-effective approach would the use of drugs combined with other methods to stop transmission, including molluscicides. The cost of molluscicides needs to be reduced and fears allayed about their supposedly adverse ecological effects.

Kinetics of T cell-activation molecules in response to Mycobacterium tuberculosis antigens

The phenotypic features acquired subsequent to antigen-specific stimulation in vitro were evaluated by means of the kinetic expressions of CD69 and CD25 activation molecules on T lymphocytes and assayed by flow cytometry in response to PPD, Ag85B, and ferritin in PPD-positive healthy control individuals. In response to PHA, CD69 staining on both CD4+ and CD8+ T cells became initially marked after 4 h, peaked at 24 h, and quickly decreased after 120 h. For CD25, a latter expression was detected around 8 h, having increased after 96 h. As expected, the response rate to the mycobacterial antigens was much lower than that to the mitogen. Positive staining was high after 96 h for CD25 and after 24 h for CD69. CD69 expression was significantly enhanced (p < 0.05) on CD8+ as compared to CD4+ T cells. High levels were also found between 96-120 h. Regarding Ag85B, CD25+ cells were mostly CD4+ instead of CD8+ T cells. Moreover, in response to ferritin, a lower CD25 expression was noted. The present data will allow further characterization of the immune response to new mycobacterial-specific antigens and their evaluation for possible inclusion in developing new diagnostic techniques for tuberculosis as well in a new vaccine to prevent the disease.

From Naples 1963 to Rome 2013 - A brief review of how the International Research Group on Ostracoda (IRGO) developed as a social communication system

The 1st International Symposium on Ostracoda (ISO) was held in Naples (1963). The philosophy behind this symposium and the logical outcome of what is now known as the International Research Group on Ostracoda (IRGO) is here reviewed, namely ostracodology over the last 50 years is sociologically analysed. Three different and important historic moments for the scientific achievements of this domain are recognised. The first one, between about 1963-1983, is related to applied research for the oil industry as well as to the great interest in the better description of the marine environment by both zoologists and palaeontologists. Another important aspect during this period was the work by researchers dealing with Palaeozoic ostracods, who had their own discussion group, IRGPO. Gradually, the merger of this latter group with those dealing with post-Palaeozoic ostracods at various meetings improved communication between the two groups of specialists. A second period was approximately delineated between 1983 and 2003. During this time-slice, more emphasis was addressed to environmental research with topics such as the study of global events and long-term climate change. Ostracodologists profited also from the research "politics" within national and international programmes. Large international research teams emerged using new research methods. During the third period (2003-2013), communication and collaborative research reached a global dimension. Amongst the topics of research we cite the reconstruction of palaeoclimate using transfer functions, the building of large datasets of ostracod distributions for regional and intercontinental studies, and the implementation of actions that should lead to taxonomic harmonisation. Projects within which molecular biological techniques are routinely used, combined with sophisticated morphological information, expanded now in their importance. The documentation of the ostracod description improved through new techniques to visualise morphological details, which stimulated also communication between ostracodologists. Efforts of making available ostracod information through newsletters and electronic media are evoked.

Binary classification of dyslipidemia from the waist-to-hip ratio and body mass index: a comparison of linear, logistic, and CART models.

BACKGROUND: We sought to improve upon previously published statistical modeling strategies for binary classification of dyslipidemia for general population screening purposes based on the waist-to-hip circumference ratio and body mass index anthropometric measurements. METHODS: Study subjects were participants in WHO-MONICA population-based surveys conducted in two Swiss regions. Outcome variables were based on the total serum cholesterol to high density lipoprotein cholesterol ratio. The other potential predictor variables were gender, age, current cigarette smoking, and hypertension. The models investigated were: (i) linear regression; (ii) logistic classification; (iii) regression trees; (iv) classification trees (iii and iv are collectively known as "CART"). Binary classification performance of the region-specific models was externally validated by classifying the subjects from the other region. RESULTS: Waist-to-hip circumference ratio and body mass index remained modest predictors of dyslipidemia. Correct classification rates for all models were 60-80%, with marked gender differences. Gender-specific models provided only small gains in classification. The external validations provided assurance about the stability of the models. CONCLUSIONS: There were no striking differences between either the algebraic (i, ii) vs. non-algebraic (iii, iv), or the regression (i, iii) vs. classification (ii, iv) modeling approaches. Anticipated advantages of the CART vs. simple additive linear and logistic models were less than expected in this particular application with a relatively small set of predictor variables. CART models may be more useful when considering main effects and interactions between larger sets of predictor variables.

Biomphalaria spp. (Preston, 1910) snails in the municipality of Juiz de Fora, Zona da Mata Mineira mesoregion, ate of Minas Gerais, Brazil

This study focuses on the geographic distribution of the snail of the genus Biomphalaria and evaluates its infectivity by Schistosoma mansoni in 5264 specimens collected in the municipality of Juiz de Fora, Minas Gerais, Brazil. Of the 31 locations studied, 6 were reservoirs, 11 rudimentary holding ponds, 7 irrigation ditches, 5 lakes, 1 ornamental pond, and 1 waterfall. Intermediate hosts were found only in the rudimentary ponds and ditches, which were 100% positive. Using morphological and molecular analysis techniques, B. tenagophila, B. peregrina, and B. straminea were identified. This is the first report of B. stramínea in the municipality, and evaluation of its infective potential revealed susceptibility of 25.4%. Although we did not find specimens of Biomphalaria infected by S. mansoni, the data obtained indicate the presence of intermediate hosts, especially in the irrigation ditches in Juiz de Fora, and their proximity to contaminated areas.

Sensitivity and specificity of polymerase chain reaction in Giemsa-stained slides for diagnosis of visceral leishmaniasis in children

The aim of this study was to evaluate the sensitivity and specificity of polymerase chain reaction (PCR) in the detection of Leishmania DNA in archived Giemsa-stained bone marrow slides for diagnosis of visceral leishmaniasis (VL), and to compare PCR with conventional diagnostic techniques, like direct microscopy and parasite culture. Specimens of archived Giemsa-stained bone marrow slides from 91 patients with VL and from 79 controls with other diseases or conditions were studied. PCR showed the highest sensitivity (92.3%) and had good specificity (97.5%). Direct examination detected 79.1% and culture 59% of positive samples. In addition, PCR was able to detect VL in 16 of 19 patients (84.2%) with negative microscopy. PCR in Giemsa-stained bone marrow slides is a suitable tool for confirming diagnosis in patients with VL and may be useful in the diagnosis of difficult cases. Slide smears are easily stored, do not require special storage conditions such as low temperatures, and can be easily mailed to centers where PCR is available, making it an excellent option for diagnosis in the field.

Targeting Angiogenesis in Glioma - Challenges and Pitfalls

Malignant gliomas, notably glioblastoma are among the most vascularized and angiogenic cancers, and microvascular proliferation is one of the hallmarks for the diagnosis of glioblastoma. Angiogenesis is regulated by a balance of pro- and antiangiogenic signals; overexpression of VEGF and activation of its receptors, most notable VEGFR-2 and -3, results in endothelial cell proliferation and leaky vasculature. Heterogeneous perfusion and oxygenation, peritumoral edema and increased interstitial pressure are the consequence. Both endothelial and tumour cells are strongly dependent on integrin-mediated adhesion for cell proliferation, survival, migration and invasion.Strategies aiming at inhibition of cell signaling and angiogenesis, including integrin inhibitors, have been clinically investigated in gliomas over the last 5 years. Radiological responses, a decreased requirement of corticosteroids and temporary improvement in performance status have repeatedly been observed. Toxicity was mild-moderate and manageable, notably there was no evidence for a substantially increased incidence of intracranial bleeding. However definitive comparative (randomized !) investigation has failed to demonstrate improved outcome with singleagent inhibition of EGFR, or PDGFR or VEGF/VEGFRs pathways in recurrent glioblastoma. Definitive phase III trials combining the anti- VEGF monoclonal antibody bevacizumab, or cilengitide, a peptidic integrininhibitor, together with temozolomide and radiotherapy are ongoing (accrual completed).The integration of anti-angiogenic strategies in the management of malignant glioma also poses entirely new challenges in patient management: 1) Many agents are known for increasing the risk of thrombosis, embolism and intracranial bleeding. 2) Evaluation of treatment efficacy is difficult and new biomarkers of activity, including functional, metabolic or molecular imaging techniques are urgently needed. Normalization of vasculature leads to decrease in contrast enhancement without necessarily reflecting tumour shrinkage. Tumour heterogeneity, putative prognostic or predictive factors require early controlled trials, novel trial designs and endpoints.3) Activation of alternate pathways and tumour escape mechanisms may require combination of multiple agents, which is often not feasible due to regulatory restrictions and potential complex toxicities. Emerging clinical and experimental evidence suggests that anti-angiogenic drugs might need to be combined with drugs targeting tumour adaptive mechanisms in addition to cytotoxic chemotherapy and irradiation for a maximal antitumour effect.