Loxosceles chapadensis (Araneae: Sicariidae): a new recluse spider species of the gaucho group from Brazil

A new species of the medically important recluse spider genus Loxosceles Heinecken & Lowe 1832 is described from the State of Bahia, Brazil. The species occurs between rocks and crevices, as well as in and around man-made structures. The new species belongs to the gaucho group, as evidenced by the spermathecal shape and color pattern. The presence of a long male palpal tibia is unusual in the gaucho group; thus, the inclusion of the new species in this group is discussed.

Impaired dendritic cell differentiation and maturation in the absence of C3

Human monocytes can be differentiated into immature dendritic cells (DCs) in the presence of serum and cytokines. One of the main functions of immature DCs is to capture and process antigens. Following maturation, they differentiate into antigen presenting cells. The role of complement in the differentiation process from monocytes towards immature DCs remains elusive. Here we demonstrate that complement 3 (C3) has a regulatory impact on the expression of specific DC surface molecules and DC-derived cytokine production during DC differentiation. We isolated human adherent peripheral blood mononuclear cells, which were cultured in the presence of GM-CSF plus IL-4 in medium supplemented with normal human serum or C3 deficient serum. The lack of C3 during DC differentiation negatively impacted the expression of C-type lectin receptor DC-SIGN, the antigen presenting molecules HLA-DR and CD1a, and the costimulatory molecules CD80 and CD86. Further, the spontaneous production of IL-6 and IL-12 was reduced in the absence of C3. Moreover, the maturation of immature DCs in response to LPS challenge was impaired in the absence of C3 as evidenced by reduced MHC-II, co-stimulatory molecule expression as well as modulated IL-12 and TNF-alpha production. Collectively, our results provide evidence for a novel role of C3 as a critical cofactor in human DC differentiation and maturation. (C) 2007 Elsevier Ltd. All rights reserved.

Mannose-binding lectin complement pathway plays a key role in complement activation by Paracoccidioides brasiliensis

Paracoccidioides brasiliensis (Pb) is a dimorphic fungal pathogen that causes paracoccidioidomycosis the most severe deep mycosis from South America Although cell mediated immunity is considered the most efficient protective mechanism against Pb infection mechanisms of innate immunity are poorly defined Herein we investigated the interaction of the complement system with high and low virulence isolates of Pb We demonstrated that Pb18 a high virulence Pb Isolate when incubated with normal human serum (NHS) induces consumption of hemolytic complement and when immobilized promotes binding of C4b C3b and C5b-C9 Both low virulence (Pb265) and high virulence (Pb18) isolates consumed C4 C3 and mannose-binding learn (MBL) of MBL-sufficient but not of MBL-deficient serum as revealed by deposition of residual C4 C3 and MBL on immune complexes and mannan However higher complement components consumption was observed with Pb265 as compared with Pb18 The suggested relationship between low virulence and significant complement activation properties of Pb isolates was confirmed by the demonstration that virulence attenuation of Pb 18 results in acquisition of the ability to activate complement Conversely reactivation of attenuated Pb18 results in loss of the ability to activate complement Our results demonstrate for the first time that Pb yeasts activate the complement system by the lectin pathway and there is an Inverse correlation between complement activating ability and Pb virulence These differences could exert an influence on Innate immunity and severity of the disease developed by infected hosts (C) 2010 Elsevier Ltd All rights reserved

Differential kinase requirement for enhancement of Fc gamma R-mediated phagocytosis in alveolar macrophages by leukotriene B(4) vs. D(4)

In alveolar macrophages, leukotriene (IT) B(4) and cysteinyl LTs (LTC(4), LTD(4) and LTE(4)) both enhance Fc gamma receptor (Fc gamma R)-mediated phagocytosis. In the present study we investigated the role of specific PKC isoforms (PKC-alpha and -delta), the MAP kinases p38 and ERK 1/2, and PI3K in mediating the potentiation of Fc gamma R-mediated phagocytosis induced by addition of leukotrienes to the AMs. It was found that exogenously added LTB(4) and LTD(4) both enhanced PKC-delta and -alpha phosphorylation during Fc gamma R engagement. Studies with isoform-selective inhibitors indicated that exogenous LTB(4) effects were dependent on both PKC-alpha and -delta, while LTD(4) effects were exclusively due to PKC-delta activation. Although both exogenous LTB(4) and LTD(4) enhanced p38 and ERK 1/2 activation, LTB(4) required only ERK 1/2, while LTD(4) required only p38 activation. Activation by both LTs was dependent on PI3K activation. Effects of endogenous LTs on kinase activation were also investigated using selective LT receptor antagonists. Endogenous LTB(4) contributed to Fc gamma R-mediated activation of PKC-alpha, ERK 1/2 and PI3K, while endogenous cysLTs contributes to activation of PKC-delta, p38 and PI3K. Taken together, our data show that the capacities of LTB(4) and LTD(4) to enhance Fc gamma R-mediated phagocytosis reflect their differential activation of specific kinase programs. (C) 2008 Elsevier Ltd. All rights reserved.

Sleep deprivation of rats: The hyperphagic response is real

Study Objectives: Chronic sleep deprivation of rats causes hyperphagia without body weight gain. Sleep deprivation hyperphagia is prompted by changes in pathways governing food intake; hyperphagia may be adaptive to sleep deprivation hypermetabolism. A recent paper suggested that sleep deprivation might inhibit ability of rats to increase food intake and that hyperphagia may be an artifact of uncorrected chow spillage. To resolve this, a palatable liquid diet (Ensure) was used where spillage is insignificant. Design: Sleep deprivation of male Sprague Dawley rats was enforced for 10 days by the flowerpot/platform paradigm. Daily food intake and body weight were measured. On day 10, rats were transcardially perfused for analysis of hypothalamic mRNA expression of the orexigen, neuropeptide Y (NPY). Setting: Morgan State University, sleep deprivation and transcardial perfusion; University of Maryland, NPY in situ hybridization and analysis. Measurements and Results: Using a liquid diet for accurate daily measurements, there was no change in food intake in the first 5 days of sleep deprivation. Importantly, from days 6-10 it increased significantly, peaking at 29% above baseline. Control rats steadily gained weight but sleep-deprived rats did not. Hypothalamic NPY mRNA levels were positively correlated to stimulation of food intake and negatively correlated with changes in body weight. Conclusion: Sleep deprivation hyperphagia may not be apparent over the short term (i.e., <= 5 days), but when extended beyond 6 days, it is readily observed. The timing of changes in body weight and food intake suggests that the negative energy balance induced by sleep deprivation prompts the neural changes that evoke hyperphagia.

Slower rescue of ER homeostasis by the unfolded protein response pathway associated with common variable immunodeficiency

Common variable immunodeficiency (CVID) is a primary immunodeficiency characterized by hypogammaglobulinemia and recurrent infections. Herein we addressed the role of unfolded protein response (UPR) in the pathogenesis of the disease. Augmented unspliced X-box binding protein 1 (XBP-1) mRNA concurrent with co-localization of IgM and BiP/GRP78 were found in one CVID patient. At confocal microscopy analysis this patient`s cells were enlarged and failed to present the typical surface distribution of IgM, which accumulated within an abnormally expanded endoplasmic reticulum. Sequencing did not reveal any mutation on XBP-1, neither on IRE-1 alpha that could potentially prevent the splicing to occur. Analysis of spliced XBP-1, IRE-1 alpha and BiP messages after LPS or Brefeldin A treatment showed that, unlike healthy controls that respond to these endoplasmic reticulum (ER) stressors by presenting waves of transcription of these three genes, this patient`s cells presented lower rates of transcription, not reaching the same level of response of healthy subjects even after 48 h of ER stress. Treatment with DMSO rescued IgM and IgG secretion as well as the expression of spliced XBP-1. Our findings associate diminished splicing of XBP-1 mRNA with accumulation of IgM within the ER and lower rates of chaperone transcription, therefore providing a mechanism to explain the observed hypogammaglobulinemia. (C) 2008 Elsevier Ltd. All rights reserved.

Differential expression of new LTA splice variants upon lymphocyte activation

Lymphotoxin alpha (LTA) is a member of the TNF cytokine superfamily, produced principally by lymphocytes. It plays an important role in immune and inflammatory responses. Many TNF superfamily members have functionally important isoforms generated by alternative splicing but alternative splicing of LTA has never been studied. The known LTA protein is encoded by a transcript containing four exons. Here we report seven new LTA splice variants, three of them evolutionary conserved. We demonstrate their presence in cytoplasmic RNA suggesting that they could be translated into new LTA isoforms. We observed that their expression is differentially regulated upon activation of peripheral blood mononuclear cells and lymphocyte subpopulations (CD4+, CD8+, and CD19+). Our data suggest that the new LTA splice variants might play a role in the regulation of the immune response. (C) 2007 Elsevier Ltd. All rights reserved.

Impaired phagocytosis by alveolar macrophages from diabetic rats is related to the deficient coupling of LTs to the Fe gamma R signaling cascade

Diabetic individuals are more susceptible to infections and this seems to be related to impaired phagocyte function. Alveolar macrophages (AMs) are the first barrier to prevent respiratory infections Leukotrienes (LTs) increase AM phagocytic activity via Fc gamma R. In this study, we compared AMs from diabetic and nondiabetic rats for phagocytosis via Fc gamma R and the roles of LTs and insulin Diabetes was induced in male Wistar rats by alloxan (42 mg/kg, i.v); macrophages were obtained by bronchoalveolar lavage and IgG-opsonised sheep red blood cells (IgG-SRBC) were used as targets. LTs were added to the AMs 5 min before the addition of IgG-SRBC. AMs were treated with a LT synthesis inhibitor (zileuton, 10 mu M), or antagonists of the LTB(4) receptor (CP105 696, 10 mu M) cys-LT receptor (MK571, 10 mu M), 30 or 20 min before the addition of IgG-SRBC, respectively. We found that the phagocytosis of IgG-SRBC by AMs from diabetic rats is impaired compared with non-diabetic rats. Treatment with the LT inhibitor/antagonists significantly reduced AM phagocytosis in non-diabetic but not diabetic rats. During the phagocytosis of IgG-SRBC LTB(4) and LTC(4) were produced by AMs from both groups. The addition of exogenous LTB(4) or LTD(4) potentiated phagocytosis similarly in both groups Phagocytosis was followed by the phosphorylation of PKC-delta. ERK and Akt This was reduced by zileuton treatment in AMs from non-diabetic but not diabetic rats The addition of insulin to AMs further increased the phagocytosis by increasing PKC-delta phosphorylation These results suggest that the impaired phagocytosis found in AMs from diabetic rats is related to a deficient coupling of LTs to the Fc gamma R signaling cascade and that insulin has a key role in this coupling An essential role for insulin in Innate immunity is suggested (C) 2010 Elsevier Ltd. All rights reserved.

Skipping of exon 30 in C5 gene results in complete human C5 deficiency and demonstrates the importance of C5d and CUB domains for stability

The deficiency of complement C5 is rare and frequently associated with severe and recurrent infections, especially caused by Neisseria spp. We observed the absence of component C5 in the serum of 3 siblings from a Brazilian family with history of consanguinity. The patients had suffered from recurrent episodes of meningitis and other less severe infections. Sera from these patients were unable to mediate hemolytic activity either by the classical or alternative pathways and presented extremely low levels of C5 protein (13, 0.9 and 1.0 mu g/ml-normal range: 45-190 mu g/ml). Hemolytic activity could be restored by the addition of purified C5 to deficient serum. Sequencing of sibling C5 cDNA revealed a homozygous 153 bp deletion that corresponds precisely to exon 30. The parents carried the same deletion but only in one allele. Sequencing of the corresponding region in the genomic DNA revealed a C to C substitution within intron 30 and, most significantly, the substitution of GAG(4028) for GAA(4028) at the 3` end of exon 30 which is most likely responsible for skipping of exon 30. The resulting in-frame deletion in the C5 mRNA codes for a mutant C5 protein lacking residues 1289-1339. These residues map to the CUB and C5d domains of the C5 alpha chain. This deletion is expected to produce a non-functional and unstable C5 protein which is more susceptible to degradation. (C) 2009 Published by Elsevier Ltd.

Methylmercury localization in Danio rerio retina after trophic and subchronic exposure: A basis for neurotoxicology

Methylmercury is a known neurotoxic organometal which affects visual functions and few studies concerns to wild fish are available. The autometallography mercury distribution in the retina of Danio rerio was mapped using light and electron microscopy. Abundant mercury deposits were found in the photoreceptor layer (outer and inner segments of the photoreceptors) and in the inner and outer nuclear layers. Occasionally, the presence of mercury deposits in plexiform layers was observed and very rarely in the ganglion cell layer. Also the occurrence of mercury deposits in cells from the disc region was observed, but not in the nerve fiber layer. An interesting difference was found between mercury accumulation in the central and peripheral regions of the retina. These results demonstrate that mercury after trophic exposure to Danio rerio is able to cross the blood-retina barrier and accumulate in the cells of the retina even under subchronic exposure. (C) 2010 Elsevier Inc. All rights reserved.

Pre-emptive epidural ketamine or S(+)-ketamine in post-incisional pain in dogs: A comparative study

Objective-To compare the pre-emptive analgesic effects of epidural ketamine or S(+)-ketamine on post-incisional hyperalgesia.Study Design-Prospective randomized study.Animals-Twenty-four mongrel dogs (1-5 years, weighing 11.9 +/- 1.8 kg).Methods-Dogs were anesthetized with propofol (5 mg/kg intravenously) and a lumbosacral epidural catheter was placed. Dogs were randomly allocated to 3 groups, each with 8 dogs. The control group (CG) was administered saline solution (0.3 mL/kg); the ketamine group (KG) ketamine (0.6 mg/kg); and the S(+)-ketamine group (SG) S(+)-ketamine (0.6 mg/kg). The final volume was adjusted to 0.3 mL/kg in all groups. Five minutes after the epidural injection a surgical incision was made in the common pad of the right hind limb and was immediately closed with simple interrupted nylon suture. Respiratory (RR) and heart (HR) rates, rectal temperature (7, sedation (S), lameness score, and mechanical nociceptive threshold by von Frey filaments were evaluated before the propofol anesthesia and at 15, 30, 45, 60, 75, and 90 minutes and then at 2, 4, 6, 8, 12, and 24 hours after epidural injection.Results-There were no differences in RR, HR, T, or S between groups. Motor blockade of the hind limbs was observed during 20 +/- 3.6 minutes in KG and during 30.6 +/- 7.5 minutes in SG (mean SD). Mechanical force applied to obtain an aversive response was higher from 45 minutes to 12 hours in KG and from 60 to 90 minutes in SG, when compared with CG.Conclusions-Pre-emptive epidural ketamine induced no alterations in RR and FIR, and reduced post-incisional hyperalgesia for a longer time than did S(+) ketamine.Clinical Relevance-Although anesthetic and analgesic potency of S(+) ketamine is twice that of ketamine, the racemic form is seemingly better for post-incisional hyperalgesia. (C) Copyright 2004 by the American College of Veterinary Surgeons.

DNA damage in lymphocytes and buccal mucosa cells of children with malignant tumours undergoing chemotherapy

The aim of the present study was to evaluate DNA damage (micronucleus) in cytokinesis-blocked lymphocytes and exfoliated buccal mucosa cells from children with malignant tumours and under chemotherapy. Micronucleated cells (MNCs) were assessed from children before and during chemotherapy. A total of 21 healthy children (controls), matched for gender and age, were used as control. The results pointed out higher frequencies of micronucleated lymphocytes in children with malignant tumour before any therapy when compared to healthy probands. Furthermore an increase of micronucleated lymphocytes during chemotherapy was detected when compared to the data obtained before chemotherapy. No statistically significant increases of MNCs were noticed in buccal mucosa cells at any of the timepoints evaluated. Taken together, these data indicate that the presence of malignant tumours may increase the frequency of DNA damage in circulating lymphocytes, these cells being more sensitive for detecting chromosome aberrations caused by anti-cancer drugs.

Comparison between procalcitonin and C-reactive protein for early diagnosis of children with sepsis or septic shock

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)