Functional complementation of a yeast knockout strain by Schistosoma mansoni Rho1 GTPase in the presence of caffeine, an agent that affects mutants defective in the protein kinase C signal transduction pathway

In a previous study, the Schistosoma mansoni Rho1 protein was able to complement Rho1 null mutant Saccharomyces cerevisiae cells at restrictive temperatures and under osmotic stress (low calcium concentration) better than the human homologue (RhoA). It is known that under osmotic stress, the S. cerevisiae Rho1 triggers two distinct pathways: activation of the membrane 1,3-beta-glucan synthase enzymatic complex and activation of the protein kinase C1 signal transduction pathway, promoting the transcription of response genes. In the present work the SmRho1 protein and its mutants smrho1E97P, smrho1L101T, and smrho1E97P, L101T were used to try to clarify the basis for the differential complementation of Rho1 knockout yeast strain by the human and S. mansoni genes. Experiments of functional complementation in the presence of caffeine and in the presence of the osmotic regulator sorbitol were conducted. SmRho1 and its mutants showed a differential complementation of the yeast cells in the presence of caffeine, since smrho1E97P and smrho1E97P, L101T mutants showed a delay in the growth when compared to the yeast complemented with the wild type SmRho1. However, in the presence of sorbitol and caffeine the wild type SmRho1 and mutants showed a similar complementation phenotype, as they allowed yeast growth in all caffeine concentrations tested.

Adherence of Abiotrophia defectiva and Granulicatella species to fibronectin: is there a link with endovascular infections?

During a 6-year period, we isolated three Abiotrophia defectiva, six Granulicatella adiacens and two G. 'para-adiacens' strains from clinical specimens. All A. defectiva strains were isolated from immunocompetent patients with endovascular infections, whereas the Granulicatella spp. strains were isolated from immunosuppressed patients with primary bacteremia. As the capacity of bacteria to adhere to the host extracellular matrix (ECM) has been implicated in the pathogenesis of endovascular infection, we investigated the ability of A. defectiva and Granulicatella spp. isolates to bind different ECM components immobilized in microtiter plates. Adherence tests showed a strong attachment of A. defectiva strains to fibronectin, whereas Granulicatella spp. strains were not adherent. The poor adherence of Granulicatella spp. strains to the ECM could be correlated with a lower propensity to induce endocarditis.

Presence of alternative lengthening of telomeres mechanism in patients with glioblastoma identifies a less aggressive tumor type with longer survival.

Patients with glioblastoma (GBM) have variable clinical courses, but the factors that underlie this heterogeneity are not understood. To determine whether the presence of the telomerase-independent alternative lengthening of telomeres (ALTs) mechanism is a significant prognostic factor for survival, we performed a retrospective analysis of 573 GBM patients. The presence of ALT was identified in paraffin sections using a combination of immunofluorescence for promyelocytic leukemia body and telomere fluorescence in situ hybridization. Alternative lengthening of telomere was present in 15% of the GBM patients. Patients with ALT had longer survival that was independent of age, surgery, and other treatments. Mutations in isocitrate dehydrogenase (IDH1mut) 1 frequently accompanied ALT, and in the presence of both molecular events, there was significantly longer overall survival. These data suggest that most ALT+ tumors may be less aggressive proneural GBMs, and the better prognosis may relate to the set of genetic changes associated with this tumor subtype. Despite improved overall survival of patients treated with the addition of chemotherapy to radiotherapy and surgery, ALT and chemotherapy independently provided a survival advantage, but these factors were not found to be additive. These results suggest a critical need for developing new therapies to target these specific GBM subtypes.

The presence of qacA/B gene in Brazilian methicillin-resistant Staphylococcus aureus

A total of 74 methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from three government hospitals in 2002 and 2003 were examined concerning the distribution of qacA/B gene, which is the determinant of resistance to quaternary ammonium compounds largely employed in hospital disinfection. By polymerase chain reaction the qacA/B gene was found in 80% of the isolates, which is a significant result considering it is the first time that qacA/B gene is being reported for Brazilian MRSA strains and it is presented at a high rate.

Association of the presence of residual anti-Toxoplasma gondii IgM in pregnant women and their respective family groups in Miracema, Northwest Rio de Janeiro, Brazil

The seroprevalence of toxoplasmosis in 832 pregnant women in Miracema, Rio de Janeiro, was determined and 75.1% (625) and 2.0% (17) were anti-Toxoplasma gondii IgG and IgM positive, respectively. Out of the 17 IgM positive pregnant women, only one had low avidity IgG corresponding to the acute phase of the infection. All the other women presented with high avidity IgG and also presented with residual IgM anti-T. gondii. Of this sample, 106 received home visits (this includes 11 family nuclei of pregnant women with residual IgM anti-T. gondii, 68 nuclei of only IgG positive pregnant women and 27 nuclei of pregnant women with no antibodies to anti-T. gondii), resulting in 267 individuals visited. Out of these 267 individuals, 21 were positive for IgG and IgM anti-T. gondii and were candidates for the IgG avidity test. All of them presented with high avidity IgG and residual IgM. Five of these IgM+ individuals were (5/238; 2.1%) relatives of IgM negative pregnant women. The other 16 (16/29; 55.2%) were relatives of IgM+ pregnant women who were positive for residual IgM anti-T. gondii. This association was statistically significant (p = 0.0000). The analysis presented herein raises questions regarding the presence of residual IgM anti-T. gondii such as genetic determinants or even constant antigenic stimuli for the same family cluster.

Postmortem circulation: a new model for testing endovascular devices and training clinicians in their use.

The development of new medical devices, such as aortic valves, requires numerous preliminary studies on animals and training of personnel on cadavers before the devices can be used in patients. Postmortem circulation, a technique used for postmortem angiography, allows the vascular system to be reperfused in a way similar to that in living persons. This technique is used for postmortem investigations to visualize the human vascular system and to make vascular diagnoses. Specific material for reperfusing a human body was developed recently. Our aim was to investigate whether postmortem circulation that imitates in vivo conditions allows for the testing of medical materials on cadavers. We did this by delivering an aortic valve using minimally invasive methods. Postmortem circulation was established in eight corpses to recreate an environment as close as possible to in vivo conditions. Mobile fluoroscopy and a percutaneous catheterization technique were used to deliver the material to the correct place. Once the valve was implanted, the heart and primary vessels were extracted to confirm its position. Postmortem circulation proved to be essential in several of the cadavers because it helped the clinicians to deliver the material and improve their implantation techniques. Due to the intravascular circulation, sites with substantial arteriosclerotic stenosis could be bypassed, which would have been impossible without perfusion. Although originally developed for postmortem investigations, this reperfusion technique could be useful for testing new medical devices intended for living patients.

Innovation strategies in the presence of technology markets: evidence from spanish innovative firms

The development of markets for technology has eased the acquisition of technology and reshaped the innovation strategies of firms that we classify as producers of innovations or as imitators. Innovative activities of firms include research, acquisition of technology and downstream activities. Within an industry, firms producing innovations tend to conduct more research and downstream activities than those imitating innovations. Acquisition of technology is equally important for both. To implement innovation strategies, firms producing innovations require both the capability to scan the external environment for technology and the capability to integrate new technology. Firms producing innovations require both, while firms imitating innovations require scan capabilities only

The Presence of Precursors of Benign Pre-B Lymphoblasts (Hematogones) in the Bone Marrow of a Paediatric Patient with Cytomegalovirus Infection

Hematogones are normal B-lymphoid precursors that multiply in the bone marrow of small children and of adults with ferropenic anaemia, neuroblastoma or idiopathic thrombocytopenic purpura. They are not normally found in peripheral blood, and the immunophenotype is virtually indistinguishable from that of B lymphoblasts. We discuss the case of a 3-month infant with an active cytomegalovirus infection, with hepatitis and pancytopenia associated with 13% hematogones in the bone marrow

Improving prediction of recanalization in acute large-vessel occlusive stroke.

BACKGROUND: Recanalization in acute ischemic stroke with large-vessel occlusion is a potent indicator of good clinical outcome. OBJECTIVE: To identify easily available clinical and radiologic variables predicting recanalization at various occlusion sites. METHODS: All consecutive, acute stroke patients from the Acute STroke Registry and Analysis of Lausanne (2003-2011) who had a large-vessel occlusion on computed tomographic angiography (CTA) (< 12 h) were included. Recanalization status was assessed at 24 h (range: 12-48 h) with CTA, magnetic resonance angiography, or ultrasonography. Complete and partial recanalization (corresponding to the modified Treatment in Cerebral Ischemia scale 2-3) were grouped together. Patients were categorized according to occlusion site and treatment modality. RESULTS: Among 439 patients, 51% (224) showed complete or partial recanalization. In multivariate analysis, recanalization of any occlusion site was most strongly associated with endovascular treatment, including bridging therapy (odds ratio [OR] 7.1, 95% confidence interval [CI] 2.2-23.2), and less so with intravenous thrombolysis (OR 1.6, 95% CI 1.0-2.6) and recanalization treatments performed beyond guidelines (OR 2.6, 95% CI 1.2-5.7). Clot location (large vs. intermediate) and tandem pathology (the combination of intracranial occlusion and symptomatic extracranial stenosis) were other variables discriminating between recanalizers and non-recanalizers. For patients with intracranial occlusions, the variables significantly associated with recanalization after 24 h were: baseline National Institutes of Health Stroke Scale (NIHSS) (OR 1.04, 95% CI 1.02-1.1), Alberta Stroke Program Early CT Score (ASPECTS) on initial computed tomography (OR 1.2, 95% CI 1.1-1.3), and an altered level of consciousness (OR 0.2, 95% CI 0.1-0.5). CONCLUSIONS: Acute endovascular treatment is the single most important factor promoting recanalization in acute ischemic stroke. The presence of extracranial vessel stenosis or occlusion decreases recanalization rates. In patients with intracranial occlusions, higher NIHSS score and ASPECTS and normal vigilance facilitate recanalization. Clinical use of these predictors could influence recanalization strategies in individual patients.

Esophageal leaks repaired by a muscle onlay approach in the presence of mediastinal sepsis.

BACKGROUND: Nineteen patients were evaluated after closure of intrathoracic esophageal leaks by a pediculated muscle flap onlay repair in the presence of mediastinal and systemic sepsis. METHODS: Intrathoracic esophageal leaks with mediastinitis and systemic sepsis occurred after delayed spontaneous perforations (n = 7) or surgical and endoscopic interventions (n = 12). Six patients presented with fulminant anastomotic leaks. Seven patients had previous attempts to close the leak by surgery (n = 4) or stenting (2) or both (n = 1). The debrided defects measured up to 2 x 12 cm or involved three quarters of the anastomotic circumference and were closed either by a full thickness diaphragmatic flap (n = 13) or a pediculated intrathoracically transposed extrathoracic muscle flap (n = 6). All patients had postoperative contrast esophagography between days 7 and 10 and an endoscopic evaluation 4 to 6 months after surgery. RESULTS: There was no 30-day mortality. During follow-up (4 to 42 months), 16 patients (84%) revealed functional and morphological restoration of the esophagointestinal integrity without further interventions. One patient required serial dilatations for a stricture, and 1 underwent temporary stenting for a persistent fistula; both patients had normal control endoscopy during follow-up. A third patient requiring permanent stenting for stenosis died from gastrointestinal bleeding due to stent erosion during follow-up. CONCLUSIONS: Intrathoracic esophageal leaks may be closed efficiently by a muscle flap onlay approach in the presence of mediastinitis and where a primary repair seems risky. The same holds true for fulminant intrathoracic anastomotic leaks after esophagectomy or other surgical interventions at the gastroesophageal junction.

Presence of maternal anti-HBs antibodies does not influence hepatitis B vaccine response in Brazilian neonates

Recently, it was suggested that maternal hepatitis B surface antigen antibodies (anti-HBs) acquired transplacentally could play a negative role in newborn infants' immune response to the hepatitis B vaccine. We compared the hepatitis B virus (HBV) vaccine response in infants born to mothers previously vaccinated against HBV (n = 91) to infants born to mothers who were not previously vaccinated (n = 221). All newborn infants received three intramuscular doses (10 μg) of HBV vaccine (Butang®) at 0,1 and six months. The first dose was administered at the maternity hospital within 12 h of birth. The geometric mean titres of anti-HBs were not different among newborn infants born to mothers who were anti-HBs-negative (492.7 mIU/mL) and anti-HBs-positive (578.7 mIU/mL) (p = 0.38). Eight infants did not respond to the HBV vaccine. Of them, six were born to anti-HBs-negative mothers and two were born to mothers with anti-HBs titres less than 50 mlU/mL. Despite the mother's anti-HBs-positive status, our data show a good immunogenicity of the Brazilian HBV recombinant vaccine in neonates.

The presence of Helicobacter pylori in the liver depends on the Th1, Th17 and Treg cytokine profile of the patient

The hypothesis that Helicobactermight be a risk factor for human liver diseases has arisen after the detection of Helicobacter DNA in hepatic tissue of patients with hepatobiliary diseases. Nevertheless, no explanation that justifies the presence of the bacterium in the human liver has been proposed. We evaluated the presence of Helicobacterin the liver of patients with hepatic diseases of different aetiologies. We prospectively evaluated 147 patients (106 with primary hepatic diseases and 41 with hepatic metastatic tumours) and 20 liver donors as controls. Helicobacter species were investigated in the liver by culture and specific 16S rDNA nested-polymerase chain reaction followed by sequencing. Serum and hepatic levels of representative cytokines of T regulatory cell, T helper (Th)1 and Th17 cell lineages were determined using enzyme linked immunosorbent assay. The data were evaluated using logistic models. Detection of Helicobacter pylori DNA in the liver was independently associated with hepatitis B virus/hepatitis C virus, pancreatic carcinoma and a cytokine pattern characterised by high interleukin (IL)-10, low/absent interferon-γ and decreased IL-17A concentrations (p < 10-3). The bacterial DNA was never detected in the liver of patients with alcoholic cirrhosis and autoimmune hepatitis that are associated with Th1/Th17 polarisation. H. pylori may be observed in the liver of patients with certain hepatic and pancreatic diseases, but this might depend on the patient cytokine profile.

DRB1*03:01 haplotypes: differential contribution to multiple sclerosis risk and specific association with the presence of intrathecal IgM bands.

BACKGROUND Multiple sclerosis (MS) is a multifactorial disease with a genetic basis. The strongest associations with the disease lie in the Human Leukocyte Antigen (HLA) region. However, except for the DRB1*15:01 allele, the main risk factor associated to MS so far, no consistent effect has been described for any other variant. One example is HLA-DRB1*03:01, with a heterogeneous effect across populations and studies. We postulate that those discrepancies could be due to differences in the diverse haplotypes bearing that allele. Thus, we aimed at studying the association of DRB1*03:01 with MS susceptibility considering this allele globally and stratified by haplotypes. We also evaluated the association with the presence of oligoclonal IgM bands against myelin lipids (OCMB) in cerebrospinal fluid. METHODS Genotyping of HLA-B, -DRB1 and -DQA1 was performed in 1068 MS patients and 624 ethnically matched healthy controls. One hundred and thirty-nine MS patients were classified according to the presence (M+, 58 patients)/absence (M-, 81 patients) of OCMB. Comparisons between groups (MS patients vs. controls and M+ vs. M-) were performed with the chi-square test or the Fisher exact test. RESULTS Association of DRB1*03:01 with MS susceptibility was observed but with different haplotypic contribution, being the ancestral haplotype (AH) 18.2 the one causing the highest risk. Comparisons between M+, M- and controls showed that the AH 18.2 was affecting only M+ individuals, conferring a risk similar to that caused by DRB1*15:01. CONCLUSIONS The diverse DRB1*03:01-containing haplotypes contribute with different risk to MS susceptibility. The AH 18.2 causes the highest risk and affects only to individuals showing OCMB.

Presence of virulence factors in Enterococcus faecalis and Enterococcus faecium susceptible and resistant to vancomycin

Despite the increasing importance of Enterococcus as opportunistic pathogens, their virulence factors are still poorly understood. This study determines the frequency of virulence factors in clinical and commensal Enterococcus isolates from inpatients in Porto Alegre, Brazil. Fifty Enterococcus isolates were analysed and the presence of the gelE, asa1 and esp genes was determined. Gelatinase activity and biofilm formation were also tested. The clonal relationships among the isolates were evaluated using pulsed-field gel electrophoresis. The asa1, gelE and esp genes were identified in 38%, 60% and 76% of all isolates, respectively. The first two genes were more prevalent in Enterococcus faecalis than in Enterococcus faecium, as was biofilm formation, which was associated with gelE and asa1 genes, but not with the esp gene. The presence of gelE and the activity of gelatinase were not fully concordant. No relationship was observed among any virulence factors and specific subclones of E. faecalis or E. faecium resistant to vancomycin. In conclusion, E. faecalis and E. faecium isolates showed significantly different patterns of virulence determinants. Neither the source of isolation nor the clonal relationship or vancomycin resistance influenced their distribution.