Toll-like receptor activity in Recurrent Aphthous Ulceration

Toll-like receptors (TLR) are membrane proteins that recognize conserved molecules derived from bacterial, virus, fungal or host tissues. Activation of TLRs causes the production of cytokines that mediate inflammatory responses and drive T helper (Th) 1 and 2 cell development. As an exaggerated Th1 immune response is supposed to be involved in pathogenesis of Recurrent Aphthous Ulceration (RAU), we suggest that RAU patients may have an imbalance in TLR pathways. To study the function of TLR activation ex vivo, peripheral blood mononuclear cells (PBMCs) from RAU patients (n = 17) and controls (n = 17) were exposed to TLR2 [lipoteichoic acid (LTA), heat-killed Listeria monocytogenes (HKLM) and PamC3CSK4], TLR3 [Poly(I:C)], TLR4 [lipopolysaccharide (LPS)], TLR5 (flagellin) and TLR7 (imiquimod) ligands, and the time course of supernatant tumor necrosis factor-alpha (TNF-alpha) levels was quantified by enzyme-linked immunosorbent assay. In addition, serological and salivary TNF-alpha and soluble CD14 levels were quantified. The TNF-alpha produced by PBMCs in contact with each TLR ligand and autologous serum or saliva at the same time was also investigated. The data were analyzed by statistical multivariate tests. The control group had a higher response to LTA, whereas RAU had a higher response to HKLM. LTA and LPS interfered with the salivary stimulation of the RAU PBMC and HKLM with the stimulation of the control. Autologous serum was capable of inhibiting TLR2 responsiveness to LTA and enhancing LPS stimulation. Salivary and serological levels of sCD14 and TNF-alpha were not significantly different. Recurrent Aphthous Ulceration patients have an anomalous activity of the TLR2 pathway that probably influences the stimulation of an abnormal Th1 immune response.

Targeted Mutagenesis in Pathogenic Leptospira Species: Disruption of the LigB Gene Does Not Affect Virulence in Animal Models of Leptospirosis

The pathogenic mechanisms of Leptospira interrogans, the causal agent of leptospirosis, remain largely unknown. This is mainly due to the lack of tools for genetically manipulating pathogenic Leptospira species. Thus, homologous recombination between introduced DNA and the corresponding chromosomal locus has never been demonstrated for this pathogen. Leptospiral immunoglobulin-like repeat (Lig) proteins were previously identified as putative Leptospira virulence factors. In this study, a ligB mutant was constructed by allelic exchange in L. interrogans; in this mutant a spectinomycin resistance (Spc(r)) gene replaced a portion of the ligB coding sequence. Gene disruption was confirmed by PCR, immunoblot analysis, and immunofluorescence studies. The ligB mutant did not show decrease virulence compared to the wild-type strain in the hamster model of leptospirosis. In addition, inoculation of rats with the ligB mutant induced persistent colonization of the kidneys. Finally, LigB was not required to mediate bacterial adherence to cultured cells. Taken together, our data provide the first evidence of site-directed homologous recombination in pathogenic Leptospira species. Furthermore, our data suggest that LigB does not play a major role in dissemination of the pathogen in the host and in the development of acute disease manifestations or persistent renal colonization.

Impaired interhemispheric interactions in patients with major depression

Previous studies have shown that patients with major depression have an interhemispheric imbalance between right and left prefrontal and motor cortex. We aimed to investigate the interhemispheric interactions in patients with major depression using repetitive transcranial magnetic stimulation (rTMS). Thirteen patients with major depression and 14 age-matched healthy subjects participated in this study. Corticospinal excitability before and after 1 Hz rTMS (applied to the left primary motor cortex) was assessed in the left and right motor cortex and these results were compared with those in healthy subjects. There was a significant difference in the interhemispheric effects between patients with depression and healthy subjects. In healthy subjects, 1 Hz rTMS significantly decreased corticospinal excitability in the stimulated, left hemisphere and increased it in the contralateral, right hemisphere. In depressed subjects, 1 Hz rTMS also decreased corticospinal excitability in the left hemisphere; however, it induced no significant changes in corticospinal excitability in the contralateral, right hemisphere. In addition, there was a significant correlation between the degree of interhemispheric modulation and the severity of the depression as indexed by the Beck Depression Inventory scores. Our findings showing a decreased interhemispheric modulation in patients with major depression are consistent with the notion that mood disorders are associated with slow interhemispheric switching mechanisms.

Resolution of sexual dysfunction during acute treatment of major depression with milnacipran

Objective The sexual function and enjoyment questionnaire (SFEQ) was developed to assess and detect changes in sexual function in men and women. The aim of the present study was to use the SFEQ to evaluate the effects of the serotonin-noradrenaline reuptake inhibitor, milnacipran, in the treatment of depression in two culturally different populations. Methods The SFEQ was employed in two studies investigating milnacipran in the treatment of major depression: a 12-week open study in Brazil and a 6-week randomised controlled study in Europe. Results At endpoint, 61.3% (Brazil) and 78.4% (Europe) of patients had >= 50% reduction of baseline Hamilton Depression Rating (HAMD) score. All SFEQ items showed improvements in sexual function in both Studies at endpoint, 60% (Brazil) and 56% (Europe) of patients stating that their Sexual desire was as great as or greater than it had been before their depressive episode. Conclusions Milnacipran appears to improve sexual function in parallel with improvement in other symptoms of depression. The SFEQ is a sensitive instrument for measuring changes in sexual function and appears to be unaffected by Cultural differences as shown by similar findings in Brazil and Europe. Copyright (C) 2008 John Wiley & Sons, Ltd.

A randomized, double-blind clinical trial on the efficacy of cortical direct current stimulation for the treatment of major depression

Preliminary findings suggest that transcranial direct current stimulation (tDCS) can have antidepressant effects. We sought to test this further in a parallel-group, double-blind clinical trial with 40 patients with major depression, medication-free randomized into three groups of treatment: anodal tDCS of the left dorsolateral prefrontal cortex (active group-`DLPFC`); anodal tDCS of the occipital cortex (active control group-`occipital`) and sham tDCS (placebo control group-`sham`). tDCS was applied for 10 sessions during a 2-wk period. Mood was evaluated by a blinded rater using the Hamilton Depression Rating Scale (HDRS) and Beck Depression Inventory (BDI). The treatment was well tolerated with minimal side-effects that were distributed equally across all treatment groups. We found significantly larger reductions in depression scores after DLPFC tDCS [HDRS reduction of 40.4 % (+/-25.8%)] compared to occipital [HDRS reduction of 21.3 % ( +/-12.9%)] and sham tDCS [HDRS reduction of 10.4 % (+/-36.6%)]. The beneficial effects of tDCS in the DLPFC group persisted for 1 month after the end of treatment. Our findings support further investigation on the effects of this novel potential therapeutic approach - tDCS - for the treatment of major depression.

Variants in the promoter region of IKBL/NFKBIL1 gene may mark susceptibility to the development of chronic Chagas` cardiomyopathy among Trypanosoma cruzi-infected individuals

Chagas` disease, caused by Trypanosoma cruzi, is an inflammatory disorder leading to chronic Chagas cardiomyopathy (CCC). Only one third of T cruzi-infected individuals progress to CCC while the others are considered asymptomatic (ASY). The human inhibitory kappa B-like gene (KBLINFKBIL1), homologous to the I kappa B family of proteins that regulate the NF kappa B family of transcription factors, is suggested as a putative inhibitor of NFKB. We investigated two functional polymorphisms, -62A/T and -262A/G, in the promoter of IKBL by PCR-RFLP analysis in 169 patients with CCC and 76 ASY. Genotype distributions for both -62A/T and -262A/G differed between the CCC and ASY (X-2 = 7.3; P = 0.025 and X-2 = 6.8; P = 0.03, respectively). Subjects, homozygous for the -62A allele, had three-fold risk of developing CCC compared with those carrying the TT genotype (P = 0.0095; Odds Ratio [OR] = 2.9; [95% CI 1.2-7.3]). Similar trend was observed for the -262A homozygotes (P = 0.005; OR = 2.7 [95% CI 1.3-6.0]. The haplotype -262A -62A was prevalent in patients with CCC (40% versus 24%; OR 2.1 [95% C1 1.4-3.3j; Pc = 0.00 14). The I kappa BL locus itself or another critical gene in this region may confer susceptibility to the development of CCC. (C) 2007 Elsevier Ltd. All rights reserved.

Enterohormonal changes after digestive adaptation: Five-year results of a surgical proposal to treat obesity and associated diseases

Background Recent physiological knowledge allows the design of bariatric procedures that aim at neuroendocrine changes instead of at restriction and malabsorption. Digestive adaptation is a surgical technique for obesity based in this rationale. Methods The technique includes a sleeve gastrectomy, an omentectomy and a jejunectomy that leaves initial jejunum and small bowel totaling at least 3 m (still within normal variation of adult human bowel length). Fasting ghrelin and resistin and fasting and postprandial GLP-1 and PYY were measured pre- and postoperatively. Results Patients: 228 patients with initial body mass index (BMI) varying from 35 to 51 kg/m(2); follow-up: I to 5 years; average EBMIL% was 79.7% in the first year; 77.7% in the second year; 71.6% in the third year; 68.9% in the fourth year. Patients present early satiety and major improvement in presurgical comorbidities, especially diabetes. Fasting ghrelin and resistin were significantly reduced (P<0.05); GLP-1 and PYY response to food ingestion was enhanced (P<0.05). Surgical complications (4.4%) were resolved without sequela and without mortality. There was neither diarrhea nor detected malabsorption. Conclusions Based on physiological and supported by evolutionary data, this procedure creates a proportionally reduced gastrointestinal (GI) tract that amplifies postprandial neuroendocrine responses. It leaves basic GI functions unharmed. It reduces production of ghrelin and resistin and takes more nutrients to be absorbed distally enhancing GLP-1 and PYY secretion. Diabetes was improved significantly without duodenal exclusion. The patients do not present symptoms nor need nutritional support or drug medication because of the procedure, which is safe to perform.

Major histocompatibility complex (MHC) class II but not MHC class I molecules are required for efficient control of Strongyloides venezuelensis infection in mice

P>Strongyloides stercoralis is an intestinal nematode capable of chronic, persistent infection and hyperinfection of the host; this can lead to dissemination, mainly in immunosuppressive states, in which the infection can become severe and result in the death of the host. In this study, we investigated the immune response against Strongyloides venezuelensis infection in major histocompatibility complex (MHC) class I or class II deficient mice. We found that MHC II(-/-) animals were more susceptible to S. venezuelensis infection as a result of the presence of an elevated number of eggs in the faeces and a delay in the elimination of adult worms compared with wild-type (WT) and MHC I(-/-) mice. Histopathological analysis revealed that MHC II(-/-) mice had a mild inflammatory infiltration in the small intestine with a reduction in tissue eosinophilia. These mice also presented a significantly lower frequency of eosinophils and mononuclear cells in the blood, together with reduced T helper type 2 (Th2) cytokines in small intestine homogenates and sera compared with WT and MHC I(-/-) animals. Additionally, levels of parasite-specific immunoglobulin M (IgM), IgA, IgE, total IgG and IgG1 were also significantly reduced in the sera of MHC II(-/-) infected mice, while a non-significant increase in the level of IgG2a was found in comparison to WT or MHC I(-/-) infected mice. Together, these data demonstrate that expression of MHC class II but not class I molecules is required to induce a predominantly Th2 response and to achieve efficient control of S. venezuelensis infection in mice.

The macrophage-derived neutrophil chemotactic factor, MNCF: A lectin with TNF-alpha-like activities on neutrophils

The macro phage-derived neutrophil chemotactic factor (MNCF) is an alpha-galactoside-binding lectin, known to induce dexamethasone-insensitive neutrophil recruitment. We further characterized MNCF effects on neutrophils and showed that it shares with TNF-alpha the ability to delay apoptosis and to trigger degranulation. MNCF and TNF-alpha effects show similar kinetics and involve Src kinases and MAPKinases dependent pathways. They were, however, clearly distinguished, since the soluble TNF-receptor etanercept prevented TNF but not MNCF effects, while melibiose disaccharide inhibited MNCF but not TNF effects. Absorption of MNCF on detoxi-gel did not alter its properties, precluding an LPS contamination effect. By contrast, galectin-3 required LPS to activate neutrophils. Specific antibodies allowed to further demonstrate that MNCF and galectin-3 are two distinct molecules. Finally, MNCF- and IL-8-induced neutrophil activation differed by their kinetic and sensitivity to pertussis toxin. In conclusion, MNCF is a distinct neutrophil agonist, with pro-inflammatory activities involving its carbohydrate recognition domain. (C) 2008 Elsevier Inc. All rights reserved.

The insulin signaling pathway in honey bee (Apis mellifera) caste development - differential expression of insulin-like peptides and insulin receptors in queen and worker larvae

The insulin/insulin-like signaling (IIS) pathway is an evolutionarily conserved module in the control of body size and correlated organ growth in metazoans. In the highly eusocial bees, the caste phenotypes differ not only in size and several structural features but also in individual fitness and life history. We investigated the developmental expression profiles of genes encoding the two insulin-like peptides (AmILP-1 and AmILP-2) and the two insulin receptors (AmInR-1 and AmInR-2) predicted in the honey bee genome. Quantitative PCR analysis for queen and worker larvae in critical stages of caste development showed that AmILP-2 is the predominantly transcribed ILP in both castes, with higher expression in workers than in queens. Expression of both InR genes sharply declined in fourth instar queen larvae, but showed little modulation in workers. On first sight, these findings are non-intuitive, considering the higher growth rates of queens, but they can be interpreted as possibly antagonistic crosstalk between the IIS module and juvenile hormone. Analyzing AmInR-1 and AmInR-2 expression in ovaries of queen and worker larvae revealed low transcript levels in queens and a sharp drop in AmInR-2 expression in fifth instar worker larvae, indicating relative independence in tissue-specific versus overall IIS pathway activity. (C) 2008 Elsevier Ltd. All rights reserved.

Differential expression of hypoxia pathway genes in honey bee (Apis mellifera L.) caste development

Diphenism in social bees is essentially contingent on nutrient-induced cellular and systemic physiological responses resulting in divergent gene expression patterns. Analyses of juvenile hormone (JH) titers and functional genomics assays of the insulin-insulin-like signaling (IIS) pathway and its associated branch, target-of-rapamycin (TOR), revealed systemic responses underlying honey bee (Apis mellifera) caste development. Nevertheless, little attention has been paid to cellular metabolic responses. Following up earlier investigations showing major caste differences in oxidative metabolism and mitochondrial physiology, we herein identified honey bee homologs of hypoxia signaling factors, HIF alpha/Sima, HIF beta/Tango and PHD/Fatiga and we investigated their transcript levels throughout critical stages of larval development. Amsima, Amtango and Amfatiga showed correlated transcriptional activity, with two peaks of occurring in both queens and workers, the first one shortly after the last larval molt and the second during the cocoon-spinning phase. Transcript levels for the three genes were consistently higher in workers. As there is no evidence for major microenvironmental differences in oxygen levels within the brood nest area, this appears to be an inherent caste character. Quantitative PCR analyses on worker brain, ovary, and leg imaginal discs showed that these tissues differ in transcript levels. Being a highly conserved pathway and linked to IIS/TOR, the hypoxia gene expression pattern seen in honey bee larvae denotes that the hypoxia pathway has undergone a transformation, at least during larval development, from a response to environmental oxygen concentrations to an endogenous regulatory factor in the diphenic development of honey bee larvae. (C) 2010 Elsevier Ltd. All rights reserved.

Anti-aversive effects of the atypical antipsychotic, aripiprazole, in animal models of anxiety

Aripiprazole is a unique antipsychotic that seems to act as a partial agonist at dopamine D2-receptors, contrasting with other drugs in this class, which are silent antagonists. Aripiprazole may also bind to serotonin receptors. Both neurotransmitters may play major roles in aversion-, anxiety-and panic-related behaviours. Thus, the present work tested the hypothesis that this antipsychotic could also have anti-aversive properties. Male Wistar rats received injections of aripiprazole (0.1-10 mg/kg) and were tested in the open field, in the elevated plus and T mazes (EPM and ETM, respectively) and in a contextual fear conditioning paradigm. Aripiprazole (1mg/kg) increased the percentage of entries onto the open arms of the EPM and attenuated escape responses in the ETM. In the latter model, the dose of 0.1 mg/kg also decreased the latency to leave the enclosed arm, suggesting anxiolytic- and panicolytic-like properties. This dose also decreased the time spent in freezing in a contextual fear conditioning. No significant motor effects were observed at these doses. The present data support the hypothesis that aripiprazole could inhibit anxiety-related responses. Acting as a partial agonist at dopamine receptors, this drug could effectively treat schizophrenia and, in contrast with most antipsychotic drugs, alleviate aversive states.

Anxiolytic-like effect of noradrenaline microinjection into the dorsal periaqueductal gray of rats

The brain noradrenergic system has been implicated in the expression of defensive behaviors elicited by acute stress. The dorsal periaqueductal gray area (dPAG) is a key structure involved in the behavioral and cardiovascular responses elicited by fear and anxiety situations. Although there are noradrenergic terminals in the dPAG, few studies have investigated the role of noradrenaline (NA) in the dPAG on anxiety modulation. The aim of this study was to evaluate the effect of NA microinjection into the dPAG of rats subjected to two animal models of anxiety, the elevated plus-maze and the Vogel conflict test. Male Wistar rats implanted with a guide cannula aimed at the dPAG received microinjections of NA (3, 15, or 45 nmol/0.05 mu l) or artificial cerebral spinal fluid into the dPAG immediately before being exposed to the elevated plus-maze or the Vogel conflict test. NA increased the exploration of the open arms and the number of enclosed arm entries in the elevated plus-maze. The increase in open arm exploration remained significant after being subjected to an analysis of covariance using the latter variable as covariate. Moreover, the NA microinjection into the dPAG did not increase general exploratory activity of animals subjected to the open-field test, indicating that the increase in open arm exploration cannot be attributed to a nonspecific increase in exploratory activity. In the Vogel test, the NA microinjection into the dPAG increased the number of punished licks without changing the number of nonpunished licks or interfering with the tail-flick test. The results, therefore, indicate that the NA microinjection into the dPAG produces anxiolytic-like effects, suggesting its possible involvement in the anxiety modulation. Behavioural Pharmacology 20:252-259 (C) 2009 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.