Recognition by toll-like receptor 2 induces antigen-presenting cell activation and Th1 programming during infection by Neospora caninum

Neospora caninum is an apicomplexan parasite responsible for major economic losses due to abortions in cattle. Toll-like receptors (TLRs) sense specific microbial products and direct downstream signaling pathways in immune cells, linking innate, and adaptive immunity. Here, we analyze the role of TLR2 on innate and adaptive immune responses during N. caninum infection. Inflammatory peritoneal macrophages and bone marrow-derived dendritic cells exposed to N. caninum-soluble antigens presented an upregulated expression of TLR2. Increased receptor expression was correlated to TLR2/MyD88-dependent antigen-presenting cell maturation and pro-inflammatory cytokine production after stimulation by antigens. Impaired innate responses observed after infection of mice genetically deficient for TLR2((-/-)) was followed by downregulation of adaptive T helper 1 (Th1) immunity, represented by diminished parasite-specific CD4(+) and CD8(+) T-cell proliferation, IFN-gamma:interleukin (IL)-10 ratio, and IgG subclass synthesis. In parallel, TLR2(-/-) mice presented higher parasite burden than wild-type (WT) mice at acute and chronic stages of infection. These results show that initial recognition of N. caninum by TLR2 participates in the generation of effector immune responses against N. caninum and imply that the receptor may be a target for future prophylactic strategies against neosporosis. Immunology and Cell Biology (2010) 88, 825-833; doi:10.1038/icb.2010.52; published online 20 April 2010

Subchondral Cystlike Lesions Develop Longitudinally in Areas of Bone Marrow Edema-like Lesions in Patients with or at Risk for Knee Osteoarthritis: Detection with MR Imaging-The MOST Study

Purpose: To assess the association of prevalent bone marrow edema-like lesions (BMLs) and full-thickness cartilage loss with incident subchondral cyst-like lesions (SCs) in the knee to evaluate the bone contusion versus synovial fluid intrusion theories of SC formation. Materials and Methods: The Multicenter Osteoarthritis study is a longitudinal study of individuals who have or are at risk for knee osteoarthritis. The HIPAA-compliant protocol was approved by the institutional review boards of all participating centers, and written informed consent was obtained from all participants. Magnetic resonance images were acquired at baseline and 30-month follow-up and read semiquantitatively by using the Whole-Organ Magnetic Resonance Imaging Score system. The tibiofemoral and patellofemoral joints were subdivided into 14 subregions. BMLs and SCs were scored from 0 to 3. Cartilage morphology was scored from 0 to 6. The association of prevalent BMLs and full-thickness cartilage loss with incident SCs in the same subregion was assessed by using logistic regression with mutual adjustment for both predictors. Results: A total of 1283 knees were included. After adjustment for full-thickness cartilage loss, prevalent BMLs showed a strong and significant association with incident SCs in the same subregion, with an odds ratio of 12.9 (95% confidence interval [CI]: 8.9, 18.6). After adjustment for BMLs, prevalent full-thickness cartilage loss showed a significant but much less important association with incident SCs in the same subregion (odds ratio, 1.4; 95% CI: 1.0, 2.0). There was no apparent relationship between severity of full-thickness cartilage loss at baseline and incident SCs. Conclusion: Prevalent BMLs strongly predict incident SCs in the same subregion, even after adjustment for full-thickness cartilage loss, which supports the bone contusion theory of SC formation. (C) RSNA, 2010

Curupira-1 and Curupira-2, two novel Mutator-like DNA transposons from the genomes of human parasites Schistosoma mansoni and Schistosoma japonicum

Transposons of the Mutator superfamily have been widely described in plants, but only recently have metazoan organisms been shown to harbour them. In this work we describe novel Mutator superfamily transposons from the genomes of the human parasites Schistosoma mansoni and S. japonicum, which we name Curupira-1 and Curupira-2. Curupira elements do not have Terminal Inverted Repeats (TIRs) at their extremities and generate Target Site Duplications (TSDs) of 9 base pairs. Curupira-2 transposons code for a conserved transposase and SWIM zinc finger domains, while Curupira-1 elements comprise these same domains plus a WRKY zinc finger. Alignment of transcript sequences from both elements back to the genomes indicates that they are subject to splicing to produce mature transcripts. Phylogenetic analyses indicate that these transposons represent a new lineage of metazoan Mutator-like elements with characteristics that are distinct from the recently described Phantom elements. Description of these novel schistosome transposons provides new insights in the evolution of transposable elements in schistosomes.

Differential diagnosis of oocysts of Hammondia-like organisms of dogs and cats by PCR-RFLP analysis of 70-kilodalton heat shock protein (HSP70) gene

Organisms of the genera Toxoplasma, Hammondia and Neospora, the Hammondia-like organisms, are closely related coccidian with similarly sized oocysts. Therefore, a diagnosis based on microscopy of oocysts in feces is not a method of choice for species identification of these important parasites. In this paper, we present a polymerase chain reaction coupled with restriction fragment length polymorphism (PCR-RFLP) method to differentially diagnose oocysts of Toxoplasma gondii from oocyst of Hammondia hammondi. Another PCR-RFLP was designed to differentiate oocysts of Hammondia heydorni from oocysts of Neospora spp. Both PCR-RFLP are based on nucleotide sequences of the Hsp70 coding gene. In conclusion, we presented two alternative molecular diagnostic assays that can be successfully applied for the differentiation of oocysts of Hammondia-like organisms shed by felids and canids.

The GABAergic system contributes to the anxiolytic-like effect of essential oil from Cymbopogon citratus (lemongrass)

Ethnopharmacological relevance: The essential oil (EO) from Cymbopogon citratus (DC) Stapf is reported to have a wide range of biological activities and is widely used in traditional medicine as an infusion or decoction. However, despite this widely use, there are few controlled studies confirming its biological activity in central nervous system. Materials and methods: The anxiolytic-like activity of the EO was investigated in light/dark box (LDB) and marble-burying test (MBT) and the antidepressant activity was investigated in forced-swimming test (FST) in mice. Flumazenil, a competitive antagonist of benzodiazepine binding and the selective 5-HT(1A) receptor antagonist WAY100635 was used in experimental procedures to determine the action mechanism of EO. To exclude any false positive results in experimental procedures, mice were submitted to the rota-rod test. We also quantified some neurotransmitters at specific brain regions after EO oral acute treatment. Results: The present work found anxiolytic-like activity of the EO at the dose of 10 mg/kg in a LDB. Flumazenil, but not WAY100635, was able to reverse the effect of the EO in the LOB, indicating that the EO activity occurs via the GABA(A) receptor-benzodiazepine complex. Only at higher doses did the EO potentiate diethyl-ether-induced sleeping time in mice. In the FST and MBT, EO showed no effect. Finally, the increase in time spent in the light chamber, demonstrated by concomitant treatment with ineffective doses of diazepam (DZP) and the EO, revealed a synergistic effect of the two compounds. The lack of activity after long-term treatment in the LDB test might be related to tolerance induction, even in the DZP-treated group. Furthermore, there were no significant differences between groups after either acute or repeated treatments with the EO in the rota-rod test. Neurochemical evaluation showed no amendments in neurotransmitter levels evaluated in cortex, striatum, pons, and hypothalamus. Conclusions: The results corroborate the use of Cymbopogon citratus in folk medicine and suggest that the anxiolytic-like effect of its EO is mediated by the GABA(A) receptor-benzodiazepine complex. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

Effect of Recombinant Bovine Somatotropin on Plasma Concentrations of Insulin-like Growth Factor I, Insulin and Membrane Integrity of Bull Spermatozoa

Contents This study aimed to evaluate the effect of the exogenous recombinant bovine somatotropin (rbST) on plasma concentrations of insulin-like growth factor I (IGF-I), insulin and semen quality of bulls. Twenty bulls (Aberdeen Angus and Brangus) were divided by breed into two groups. Placebo group was injected with NaCl 0.9% (s.c.) and treatment group with rbST (s.c., 500 mg) at days 0 and 14 of the experiment. Immediately after semen collection, blood samples were taken on days 0, 14, 28, 42 and 56 of the experiment. Semen was also collected on day 70 of the experiment. Evaluation of sperm motility was performed at pre-freezing and post-thawing stage, whereas assessment of sperm membrane integrity was performed after freezing and thawing. Analysis of data revealed that the effect of treatment and treatment-by-collection day on plasma concentrations of IGF-I and insulin was not significant. However, mean plasma concentrations of IGF-I and insulin were affected (p < 0.0001) by days of blood sampling. Effect of treatment and treatment-by-collection day on motility of spermatozoa was similar (p > 0.05) at pre-freezing and post-thawing stage. Intactness of plasmalemma and tail membrane of spermatozoa at post-thawing stage was higher (p < 0.05) in rbST-treated group than in control. In conclusion, rbST did not affect plasma concentrations of IGF-I and insulin, however, it did improve post-thaw sperm membrane integrity.

Exercise training accelerates the removal from plasma of LDL-like nanoemulsion in moderately hypercholesterolemic subjects

Objective: Exercise training improves plasma lipid profile and diminishes risk of coronary heart disease. Previously, we showed that training increases LDL plasma clearance, as tested by an artificial LDL-like nanoemulsion method, presumably by increasing LDL receptor activity. In this study, we investigated whether training could also improve LDL clearance in hypercholesterolemic subjects (HCh) that are exposed to increased risk of cardiovascular events. Methods: Twenty sedentary HCh and 20 normolipidemic (NL) sedentary volunteers were divided into four groups: 12 HCh submitted to 4-month training program, 8 HCh with no exercise program, 12 NL submitted to 4-month training and 8 NL with no exercise program. An LDL-like nanoemulsion labeled with 14C-cholesteryl ester was injected intravenously into all subjects and plasma samples were collected during 24h after injection to determine the fractional clearance rate (FCR, in h-1) by compartmental analysis. The study was performed on the first and on the last day of the 4-month study period. Results: In both, trained HCh and NL groups, training increased nanoemulsion FCR by 36% (0.0443 +/- 0.0126; 0.0602 +/- 0.0187, p=0.0187 and 0.0503 +/- 0.0203; 0.0686 +/- 0.0216, p=0.0827, respectively). After training, LDL cholesterol diminished in both HCh and NL groups. In HCh, but not in NL group, LDL susceptibility to oxidation decreased, but oxidized LDL was unchanged. In both non-trained groups FCR was the same for the last and the 4-month previous evaluation. Conclusion: In HCh, exercise training increased the removal of LDL as tested by the nanoemulsion, and this probably accounted for decreased LDL cholesterol and diminished LDL susceptibility to oxidation. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Insulin-like growth factor-1 protects preimplantation embryos from anti-developmental actions of menadione

Menadione is a naphthoquinone used as a vitamin K source in animal feed that can generate reactive oxygen species (ROS) and cause apoptosis. Here, we examined whether menadione reduces development of preimplantation bovine embryos in a ROS-dependent process and tested the hypothesis that actions of menadione would be reduced by insulin-like growth factor-1 (IGF-1). Menadione caused a concentration-dependent decrease in the proportion of embryos that became blastocysts. All concentrations tested (1, 2.5, and 5.0 mu M) inhibited development. Treatment with 100 ng/ml IGF-1 reduced the magnitude of the anti-developmental effects of the two lowest menadione concentrations. Menadione also caused a concentration-dependent increase in the percent of cells positive for the TUNEL reaction. The response was lower for IGF-1-treated embryos. The effects of menadione were mediated by ROS because (1) the anti-developmental effect of menadione was blocked by the antioxidants dithiothreitol and Trolox and (2) menadione caused an increase in ROS generation. Treatment with IGF-1 did not reduce ROS formation in menadione-treated embryos. In conclusion, concentrations of menadione as low as 1.0 mu M can compromise development of bovine preimplantation embryos to the blastocyst stage of development in a ROS-dependent mechanism. Anti-developmental actions of menadione can be blocked by IGF-1 through effects downstream of ROS generation.

Effect of recombinant human bone morphogenetic protein-7 (rhBMP-7) on the viability, proliferation and differentiation of osteoblast-like cells cultured on a chemically modified titanium surface

Aim: The aim of the present study was to assess the influence of the chemical characteristics and roughness of titanium surfaces on the viability, proliferation and differentiation of osteoblast-like cells cultured in a medium supplemented with recombinant human bone morphogenetic protein-7 (rhBMP-7). Material and methods: Osteo-1 cells were grown on titanium disks presenting with the following surfaces: (1) machined, (2) coarse grit-blasted and acid-attacked (SLA) and (3) chemically modified SLA (SLAmod) in the absence or presence of 20 ng/ml rhBMP-7 in culture medium. The viability and number of osteo-1 cells were evaluated after 24 h. Analyses of total protein content (TP) and alkaline phosphatase (AP) activity at 7, 14 and 21 days, collagen content at 7 and 21 days and mineralized matrix formation at 21 days were performed. Results: Cell viability (P=0.5516), cell number (P=0.3485), collagen content (P=0.1165) and mineralized matrix formation (P=0.5319) were not affected by the different surface configurations or by the addition of rhBMP-7 to the medium. Osteo-1 cells cultured on SLA surfaces showed a significant increase in TP at 21 days. The ALPase/TP ratio (P=0.00001) was affected by treatment and time. Conclusion: The results suggest that the addition of rhBMP-7 to the culture medium did not exert any effect on the viability, proliferation or differentiation of osteoblast-like cells grown on the different surfaces tested. All titanium surfaces analyzed allowed the complete expression of the osteoblast phenotype such as matrix mineralization by osteo-1 cells.

The essential role of toll like receptor-4 in the control of Aggregatibacter actinomycetemcomitans infection in mice

Objective: Aggregatibacter actinomycetemcomitans is an oral Gram-negative bacterium that contributes to periodontitis progression. Isolated antigens from A. actinomycetemcomitans could be activating innate immune cells through Toll-like receptors (TLRs). In this study, we evaluated the role of TLR4 in the control of A. actinomycetemcomitans infection. Material and Methods: We examined the mechanisms that modulate the outcome of A. actinomycetemcomitans-induced periodontal disease in TLR4(-/-) mice. The production of cytokines was evaluated by ELISA. The bacterial load was determined by counting the number of colony-forming units per gram of tissue. Results: The results showed that TLR4-deficient mice developed less severe periodontitis after A. actinomycetemcomitans infection, characterized by significantly lower bone loss and inflammatory cell migration to periodontal tissues. However, the absence of TLR4 facilitated the A. actinomycetemcomitans dissemination. Myeloperoxidase activity was diminished in the periodontal tissue of TLR4(-/-) mice. We observed a significant reduction in the production of tumour necrosis factor-alpha (TNF-alpha) and interleukin (IL)-1 beta in the periodontal tissue of TLR4(-/-) mice. Conclusion: The results of this study highlighted the role of TLR4 in controlling A. actinomycetemcomitans infection.

The Role of Toll-Like Receptor 2 in the Recognition of Aggregatibacter actinomycetemcomitans

Background: Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans) is a Gram-negative bacterium present in the oral cavity and is usually associated with localized aggressive periodontitis. Isolated antigens from A. actinomycetemcomitans can activate innate immune cells through Toll-like receptors (TLRs), which are molecules that recognize structural components conserved among microorganisms. In this study, we evaluate the role of TLR2 in the recognition of A. actinomycetemcomitans. Methods: Macrophages and neutrophils from knockout mice with targeted disruption of TLR2 (TLR2(-/-) mice) and wild-type mice were collected and used for the subsequent assays. The production of cytokines and chemokines was evaluated by enzyme-linked immunosorbent assay (ELISA), and the presence of apoptotic cells was determined by flow cytometry. In addition, the mechanisms that modulate the outcome of A. actinomycetemcomitans-induced periodontal disease in TLR2(-/-) mice were examined. Results: The results show that TLR2-deficient mice developed more severe periodontitis after A. actinomycetemcomitans infection, characterized by significantly higher bone loss and inflammatory cell migration to periodontal tissues. The inflammatory cell influx into the peritoneal cavities of TLR2(-/-) mice was three-fold lower than that observed for the littermate controls. A significantly diminished production of the cytokines tumor necrosis factor-alpha and interleukin-1 beta as well as the chemokine CC-ligand-5 in the peritoneal cavities of TLR2(-/-) mice was observed. In addition, a high frequency of apoptotic cells in the inflammatory exudates from TLR2(-/-) mice was observed. Phagocytosis and nitric oxide production was diminished in cells from TLR2(-/-) mice, facilitating the dissemination of the pathogen to the spleen. Conclusion: The results of this study highlight the involvement of TLR2 in recognizing A. actinomycetemcomitans and its essential role in controlling A. actinomycetemcomitans infection. J Periodontot 2009,80:2070-2019.

A new integrable model of strongly correlated electrons with Hubbard-like interaction

A new completely integrable model of strongly correlated electrons is proposed which describes two competitive interactions: one is the correlated one-particle hopping, the other is the Hubbard-like interaction. The integrability follows from the fact that the Hamiltonian is derivable from a one-parameter family of commuting transfer matrices. The Bethe ansatz equations are derived by algebraic Bethe ansatz method.