Neutrophil infiltration is implicated in the sustained thermal hyperalgesic response evoked by allergen provocation in actively sensitized rats

It has been proposed that allergen provocation induces hyperalgesia but the involvement of immunoglobulin E and leukocytes remains poorly understood. Here, we have compared the profile of allergen-evoked thermal hyperalgesic response in both passively and actively sensitized rats, and investigated the role of leukocytes in allergen-evoked nociception. Wistar rats were passively sensitized with an intraplantar injection of immunoglobulin E anti-dinitrophenylated bovine serum albumin monoclonal antibody (0.5 microg/paw), and challenged with dinitrophenylated bovine serum albumin (0.5 microg/paw) 24 h later. Alternatively, the animals were actively sensitized with a mixture of Al(OH)3 and ovalbumin and challenged intraplantarly with ovalbumin (12 microg/paw) 14 days later. We found that the thermal hyperalgesic responses set in very rapidly and with comparable intensity in both passively and actively sensitized rats. However, while in the former group the response was shorter, peaking within 1 h and reducing thereafter, a marked plateau was observed from 1 to 6 h post-challenge in the latter group. Actively sensitized rats also had higher neutrophil influx in the plantar tissue, as attested by both myeloperoxidase activity and histological analysis. Treatment of actively sensitized rats with either fucoidin (10 mg/kg, i.v) or anti-rat neutrophil antiserum (i.p.) reduced neutrophil accumulation and the late hyperalgesic response noted from 3 to 6 h post-challenge. Thus, we conclude that though immunoglobulin E-mediated mechanisms can cause thermal hyperalgesia, components of the cellular immune reaction are crucial in order to amplify and sustain the immediate hyperalgesic response triggered by allergen, in a process dependent on neutrophil recruitment.     

Antibodies against beta2-glycoprotein I complexed with an oxidised lipoprotein relate to intima thickening of carotid arteries in primary antiphospholipid syndrome

To explore whether antibodies against beta2-glycoprotein I (beta2GPI) complexed to 7-ketocholesteryl-9-carboxynonanoate (oxLig-1) and to oxidised low-density lipoproteins (oxLDL) relate to paraoxonase activity (PONa) and/or intima media thickness (IMT) of carotid arteries in primary antiphospholipid syndrome (PAPS). As many as 29 thrombotic patients with PAPS, 10 subjects with idiopathic antiphospholipid antibodies (aPL) without thrombosis, 17 thrombotic patients with inherited thrombophilia and 23 healthy controls were investigated. The following were measured in all participants: beta2GPI-oxLDL complexes, IgG anti-beta2GPI-oxLig-1, IgG anti-beta2GPI-oxLDL antibodies (ELISA), PONa, (para-nitrophenol method), IMT of common carotid (CC) artery, carotid bifurcation (B), internal carotid (IC) by high resolution sonography. Beta2GPI-oxLDL complex was highest in the control group (p < 0.01), whereas, IgG anti-beta2GPI-oxLig1 and IgG anti-beta2GPI-oxLDL were highest in PAPS (p < 0.0001). In healthy controls, beta2GPI-oxLDL complexes positively correlated to IMT of the IC (p = 0.007) and negatively to PONa after correction for age (p < 0.03). PONa inversely correlated with age (p = 0.008). In PAPS, IgG anti-beta2GPI-oxLig-1 independently predicted PONa (p = 0.02) and IMT of B (p = 0.003), CC, (p = 0.03) and of IC (p = 0.04). In PAPS, PONa inversely correlated to the IMT of B, CC and IC (p = 0.01, 0.02 and 0.003, respectively). IgG anti-beta2GPI-oxLig-1 may be involved in PAPS related atherogenesis via decreased PON activity.     

Multilevel assessment of determinants of dental caries experience in Brazil

OBJECTIVE: To examine contextual and individual determinants of dental caries experience, documenting levels of the disease in Brazil. METHODS: The dental status of 34 550 12-year-old schoolchildren was informed by a country-wide survey of oral health comprising 250 towns and performed in 2002-2003. Indices assessing dental caries experience were compared by sociodemographic characteristics of examined children (gender, ethnic group, localization and type of school), and geographic characteristics of participating towns [the human development index (HDI), and access to fluoridated tap water]. A multilevel model fitted the adjustment of untreated caries to individual and contextual covariates. RESULTS: Better-off Brazilian regions presented an improved profile of dental health, besides having a less unequal distribution of restorative dental treatments between blacks and whites, rural and urban areas, and public and private schools. Girls [odds ratio (OR)=1.1; 95% confidence interval (CI): 1.0-1.1], blacks (OR=1.6; 95% CI: 1.5-1.7), and children studying in rural areas (OR=1.9; 95% CI: 1.7-2.0) and public schools (OR=1.7; 95% CI: 1.6-1.9) presented higher odds of having untreated decayed teeth. The multilevel model identified the fluoride status of tap water (beta=-0.3), the proportion of households linked to the water network (beta=-0.3), and the HDI (beta=-0.2), as town-level variables associated with caries levels. CONCLUSION: Dental caries experience is prone to sociodemographic and geographic inequalities. The monitoring of contrasts in dental health outcomes is relevant for programming socially appropriate interventions aimed both at overall improvements and at the targeting of resources for groups of population presenting higher levels of needs.     

Purification of adenoviral vectors using expanded bed chromatography

The increasing numbers of pre-clinical and clinical trials where recombinant adenoviral vectors are used for gene therapy and vaccination require the development of cost-effective and reproducible large scale purification strategies of the biologically active particles. Alternatives to the traditional laboratory scale CsCl density gradient ultracentrifugation method, such as fixed bed chromatography strategies, have been developed, but the yields of final recovery remain too low due mainly to the capture and concentration steps taking place before and between the chromatographic stages. In this study, a rapid and efficient scale-able purification protocol allowing to obtain concentrated, pure and bioactive adenoviral vectors was developed. This allows efficient levels of binding to the column media and vector purification without centrifugation or filtration steps. Expanded bed chromatography followed by hollow fiber concentration allows the capture of viral particles directly from cellular extracts with high efficiency and vector purification is achieved in less than one working day with a minimal amount of sample handling, thus presenting an improvement over existing processes. The overall process yield reached 32%, representing an eight-fold improvement over results reported previously, while the purity is comparable to that obtained with the CsCl method.     

Identification of clinical isolates of indole-positive and indole-negative Klebsiella spp

Biochemical methods employed to classify bacterial species have limitations and may have contributed to the taxonomic complexity recently reported for the genus Klebsiella. The objective of the present study was to apply a simple biochemical test panel to classify a collection of human Klebsiella isolates. We found that with only three additional tests, it is possible to place most isolates in a defined species. Analysis of a 512-bp sequence of the rpoB gene was used as the reference. A total of 16 conventional and 4 supplementary tests were used to evaluate 122 recent isolates identified as Klebsiella from 120 patients, isolated at the clinical laboratory of a university hospital in Minas Gerais, Brazil. Of these, 102 (84%) isolates were identified as Klebsiella pneumoniae or Klebsiella variicola, 19 (15%) as Klebsiella oxytoca, and 1 (1%) as Raoultella planticola. Enterobacterial repetitive intergenic consensus-PCR typing revealed a diversity of genotypes. rpoB gene sequencing confirmed the phenotypic identification and detected five K. variicola isolates among the K. pneumoniae/K. variicola group. Three additional tests that include growth at 10 degrees C and histamine and d-melezitose assimilation should be considered essential tests for the typing of Klebsiella isolates.     

Genetic diversity and antimicrobial resistance of enterococcal isolates from Southern region of Brazil

In the present study, a total of 455 enterococcal isolates, recovered from patients living in the city of Porto Alegre, State of Rio Grande do Sul, Brazil, during the period from July 1996 to June 1997, were identified to the species level by conventional biochemical and microbiological tests, and assayed for their susceptibilities to antimicrobial agents. The genetic diversity of antimicrobial resistant strains was evaluated by pulsed-field gel electrophoresis (PFGE) analysis of SmaI restricted chromosomal DNA. The most frequent species was Enterococcus faecalis (92.8%). Other species identified were: E. faecium (2.9%), E. gallinarum (1.5%), E. avium (1.1%), E. hirae (0.7%), E. casseliflavus (0.4%), E. durans (0.4%) and E. raffinosus (0.2%). The overall prevalence of isolates with high-level resistance (HLR) to aminoglycosides was 37.8%. HLR to gentamicin was found in 24.8%. No strains with acquired resistance to vancomycin were found. PFGE analysis showed the predominance of clonal group A, comprising strains isolated from different clinical specimens obtained from patients in three hospitals. These results suggest intra and inter-hospital dissemination of one predominant clonal group of E. faecalis isolates with HLR to gentamicin in the hospitals included in this study.     

Safety of intra-arterial autologous bone marrow mononuclear cell transplantation for acute ischemic stroke

Stroke is the third cause of death and the leading cause of disability in adult subjects. Although stroke mortality has been declining in some countries, stroke morbidity has been increasing due to the aging of population and patients improved survival. Treatment with recombinant tissue plasminogen activator (rtPA) is successful provided it is administered within 3 hours of symptoms onset, but its use is limited to about 5% of the patients with acute ischemic stroke. Furthermore, no neuroprotective agent has yet been proven effective in human clinical trials. The development of other therapeutic strategies is, therefore, warranted. The use of stem cells in animal models has led to functional improvement following stroke. Recent publications have shown that bone marrow mononuclear cells (BM-MNC) therapy through intracoronary injection is a safe procedure in patients with acute or chronic ischemic heart disease. Based on these preliminary data, there has been growing interest in the study of BM-MNC transplantation for acute ischemic stroke. We report the first case of intra-arterial autologous BM-MNC transplantation for acute ischemic stroke.