Distinctive Immunomodulatory and Inflammatory Properties of the Escherichia coli Type II Heat-Labile Enterotoxin LT-IIa and Its B Pentamer following Intradermal Administration

The type I and type II heat-labile enterotoxins (LT-I and LT-II) are strong mucosal adjuvants when they are coadministered with soluble antigens. Nonetheless, data on the parenteral adjuvant activities of LT-II are still limited. Particularly, no previous study has evaluated the adjuvant effects and induced inflammatory reactions of LT-II holotoxins or their B pentameric subunits after delivery via the intradermal (i.d.) route to mice. In the present report, the adjuvant and local skin inflammatory effects of LT-IIa and its B subunit pentamer (LT-IIaB(5)) were determined. When coadministered with ovalbumin (OVA), LT-IIa and, to a lesser extent, LT-IIaB(5) exhibited serum IgG adjuvant effects. In addition, LT-IIa but not LT-IIaB(5) induced T cell-specific anti-OVA responses, particularly in respect to induction of antigen-specific cytotoxic CD8(+) T cell responses. LT-IIa and LT-IIaB(5) induced differential tissue permeability and local inflammatory reactions after i.d. injection. Of particular interest was the reduced or complete lack of local reactions, such as edema and tissue induration, in mice i.d. inoculated with LT-IIa and LT-IIaB(5), respectively, compared with mice immunized with LT-I. In conclusion, the present results show that LT-IIa and, to a lesser extent, LT-IIaB(5) exert adjuvant effects when they are delivered via the i.d. route. In addition, the low inflammatory effects of LT-IIa and LT-IIaB(5) in comparison to those of LT-I support the usefulness of LT-IIa and LT-IIaB(5) as parenterally delivered vaccine adjuvants.

Peptide gomesin triggers cell death through L-type channel calcium influx, MAPK/ERK, PKC and PI3K signaling and generation of reactive oxygen species

Gomesin is an antimicrobial peptide isolated from hemocytes of a common Brazilian tarantula spider named Acanthoscurriagomesiana. This peptide exerts antitumor activity in vitro and in vivo by an unknown mechanism. In this study, the cytotoxic mechanism of gomesin in human neuroblastoma SH-SY5Y and rat pheochromocytoma PC12 cells was investigated. Gomesin induced necrotic cell death and was cytotoxic to SH-SY5Y and PC12 cells. The peptide evoked a rapid and transient elevation of intracellular calcium levels in Fluo-4-AM loaded PC12 cells, which was inhibited by nimodipine, an L-type calcium channel blocker. Preincubation with nimodipine also inhibited cell death induced by gomesin in SH-SY5Y and PC12 cells. Gomesin-induced cell death was prevented by the pretreatment with MAPK/ERK, PKC or PI3K inhibitors, but not with PKA inhibitor. In addition, gomesin generated reactive oxygen species (ROS) in SH-SY5Y cells, which were blocked with nimodipine and MAPK/ERK, PKC or PI3K inhibitors. Taken together, these results suggest that gomesin could be a useful anticancer agent, which mechanism of cytotoxicity implicates calcium entry through L-type calcium channels, activation of MAPK/ERK, PKC and PI3K signaling as well as the generation of reactive oxygen species. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

5-HT(1B) receptor in the suprachiasmatic nucleus of the common marmoset (Callithrix jacchus)

Serotonin (5-HT) is involved in the fine adjustments at several brain centers including the core of the mammal circadian timing system (CTS) and the hypothalamic suprachiasmatic nucleus (SCN). The SCN receives massive serotonergic projections from the midbrain raphe nuclei, whose inputs are described in rats as ramifying at its ventral portion overlapping the retinohypothalamic and geniculohypothalamic fibers. In the SCN, the 5-HT actions are reported as being primarily mediated by the 5-HT1 type receptor with noted emphasis for 5-HT(1B) subtype, supposedly modulating the retinal input in a presynaptic way. In this study in a New World primate species, the common marmoset (Callithrix jacchus), we showed the 5-HT(1B) receptor distribution at the dorsal SCN concurrent with a distinctive location of 5-HT-immunoreactive fibers. This finding addresses to a new discussion on the regulation and synchronization of the circadian rhythms in recent primates. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Clinical significance of lifetime panic disorder in the course of bipolar disorder type I

Objectives: The aim of the study was to analyze the impact of lifetime panic disorder (PD) diagnosis in a sample of patients with bipolar disorder type I (BPI), evaluating clinical and demographic variables. Methods: Ninety-five outpatients from the Bipolar Disorder Research Program at the Institute of Psychiatry of the University of Sao Paulo Medical School were enrolled. Twenty-seven BPI patients with PD were compared to 68 BPI patients without any anxiety disorders regarding clinical and demographic variables. Results: Compared to BPI patients without any anxiety disorders, patients with BPI + PD presented significantly higher number of mood episodes (18.9 +/- 13.8 vs 8.5 +/- 7.8; P < .001), depressive episodes (10.8 +/- 8.2 vs 4.6 +/- 4,8; P = .001), and manic episodes (7.4 +/- 7.3 vs 3.6 +/- 3.6; P = .008). Patients with BPI + PD had more frequently a depressive episode as their first one compared to BPI patients without anxiety disorders (94.1% vs 57.5%; P = .011). Patients with BPI + PD had more comorbidity with lifetime diagnosis of drug abuse or dependence (33.3% vs 8.8%; P = .010) and eating disorders (29.6% vs 6.0%; P = .004). Conclusions: The higher number of mood episodes in general presented by patients with BPI + PD when compared with BPI patients without any anxiety disorders, along with the higher frequencies of drug misuse and eating disorders, indicates that PD comorbidity is associated with a poorer Course and outcome of BPI. The higher frequency of depression as the onset mood episode and the higher number of manic episodes in the group with PD may have important treatment implications and should be further investigated. (C) 2009 Elsevier Inc. All rights reserved.

Structural and magnetic properties and hyperfine interaction in La(3.5)Ru(4)O(13) compound

Structural, magnetic and hyperfine interaction measurements have been carried out on the novel compound La(3.5)Ru(4)O(13) prepared under two different atmospheres (air and oxygen flow). This compound is formed in the orthorhombic structure (space group Pmmm, # 47). The coexistence of the triple-layered perovskite-type planes (quasi-2D structure) and the rutile-like slabs (1D structure) leads to interesting magnetic and electronic properties in this compound. The magnetic susceptibility of this system shows a peak at T similar to 47 K associated with antiferromagnetic interactions. The Curie-Weiss behaviour of the susceptibility provides an effective magnetic moment consistent with Ru ions in low-spin state. Perturbed angular correlation measurements carried out with (111)Cd probe in the temperature range 10-60 K reveal only quadrupole interactions and indicate the occurrence of structural distortions for T<40K. (C) 2009 Elsevier B.V. All rights reserved.

Modeling Adsorption Processes of Poly-p-phenylenevinylene Precursor and Sodium Acid Dodecylbenzenesulfonate onto Layer-by-Layer Films Using a Langmuir-type Metastable Equilibrium Model

The adsorption kinetics curves of poly(xylylidene tetrahydrothiophenium chloride) (PTHT), a poly-p-phenylenevinylene (PPV) precursor, and the sodium salt of dodecylbenzene sulfonic acid (DBS), onto (PTHT/DBS)(n) layer-by-layer (LBL) films were characterized by means of UV-vis spectroscopy. The amount of PTHT/DBS and PTHT adsorbed on each layer was shown to be practically independent of adsorption time. A Langmuir-type metastable equilibrium model was used to adjust the adsorption isotherms data and to estimate adsorption/desorption coefficients ratios, k = k(ads)/k(des), values of 2 x 10(5) and 4 x 10(6) for PTHT and PTHT/DBS layers, respectively. The desorption coefficient has been estimated, using literature values for poly(o-methoxyaniline) desorption coefficient, as was found to be in the range of 10(-9) to 10(-6) s(-1), indicating that quasi equilibrium is rapidly attained.

Isolation and characterization of four type 2 ribosome inactivating pulchellin isoforms from Abrus pulchellus seeds

Abrus pulchellus seeds contain at least seven closely related and highly toxic type 2 ribosome-inactivating pulchellins, each consisting of a toxic A-chain linked to a sugar binding B-chain. In the present study, four pulchellin isoforms (termed P I, P II, P III and P IV) were isolated by affinity, ion exchange and chromatofocusing chromatographies, and investigated with respect to toxicity and sugar binding specificity. Half maximal inhibitory concentration and median lethal dose values indicate that P I and P II have similar toxicities and that both are more toxic to cultured HeLa cells and mice than P III and P IV. Interestingly, the secondary structural characteristics and sugar binding properties of the respective pairs of isoforms correlate well with the two toxicity levels, in that P I/P II and P III/P IV form two specific subgroups. From the deduced amino acids sequences of the four isoforms, it is clear that the highest similarity within each subgroup is found to occur within domain 2 of the B-chains, suggesting that the disparity in toxicity levels might be attributed to subtle differences in B-chain-mediated cell surface interactions that precede and determine toxin uptake pathways.

Catecholase and DNase activities of copper(II) complexes containing phenolate-type ligands

Three new homodinuclear complexes containing substituted phenolate-type ligands based on the N(5)O(2) donor (2-(N,N-Bis(2-pyridylmethyl)aminomethyl)-6-(N`,N`-(2-hydroxybenzyl)(2-pyridylmethyl))aminomethyl)-4-methylphenol (H(2)L-H) were synthesized and characterized by X-ray crystallography. Potentiometric titration studies in 70% (v/v) aqueous ethanol show that all three complexes exhibit a common {Cu(II)(mu-phenoxo)(mu-OH)Cu(II)(OH)} core in solution. Kinetic studies on the oxidation reaction of 3,5-di-tert-butylcatechol revealed that the catalytic activity of the metal complexes increases toward the ligand containing an electron-donating group. In addition, these complexes also carried out DNA cleavage by hydrolytic and oxidative pathways. Copyright (C) 2010 John Wiley & Sons, Ltd.

The onset of flood basalt volcanism, Northern Parana Basin, Brazil: A precise U-Pb baddeleyite/zircon age for a Chapeco-type dacite

We report the first U-Pb baddeleyite/zircon date for a felsic volcanic rock from the Parana Large Igneous Province in south Brazil. The new date of 134.3 +/- 0.8 Ma for a hypocrystalline Chapeco-type dacite from Ourinhos (northern Parana basin) is an important regional time marker for the onset of flood basalt volcanism in the northern and western portion of the province. The dated dacite was erupted onto basement rocks and is overlain by a high-Ti basalt sequence, interpreted to be correlative with Pitanga basalts elsewhere. This new U-Pb date for the Ourinhos dacite is consistent with the local stratigraphy being slightly older than the few reliable step-heating (40)Ar/(39)Ar dates currently available for overlying high-Ti basalts (133.6-131.5 Ma). This indicates an similar to 3 Ma time span for the building of the voluminous high-Ti lava sequence of the Parana basin. On the other hand, it overlaps the (40)Ar/(39)Ar dates (134.8-134.1 Ma) available for the stratigraphically older low-Ti basalt (Gramado + Esmeralda types) and dacite-rhyolite (Palmas type) sequences from South Brazil, which is consistent with the short-lived character of this volcanism and its rapid succession by the high-Ti sequence. (C) 2010 Elsevier B.V. All rights reserved.

Sequence and Structural Analysis of the 5 ` Noncoding Region of Hepatitis C Virus in Patients With Chronic Infection

Hepatitis C virus (HCV), exhibits considerable genetic diversity, but presents a relatively well conserved 5 ` noncoding region (5 ` NCR) among all genotypes. In this study, the structural features and translational efficiency of the HCV 5 ` NCR sequences were analyzed using the programs RNAfold, RNAshapes and RNApdist and with a bicistronic dual luciferase expression system, respectively. RNA structure prediction software indicated that base substitutions will alter potentially the 5 ` NCR structure. The heterogeneous sequence observed on 5 ` NCR led to important changes in their translation efficiency in different cell culture lines. Interactions of the viral RNA with cellular transacting factors may vary according to the cell type and viral genome polymorphisms that may result in the translational efficiency observed. J. Med. Virol. 81: 1212-1219, 2009. (C) 2009 Wiley-Liss, Inc.

Accumulation of (5 ` S)-8,5 `-cyclo-2 `-deoxyadenosine in organs of Cockayne syndrome complementation group B gene knockout mice

Cockayne syndrome (CS) is a human genetic disorder characterized by sensitivity to UV radiation, neurodegeneration, premature aging among other phenotypes. CS complementation group B (CS-B) gene (csb) encodes the CSB protein (CSB) that is involved in base excision repair of a number of oxidatively induced lesions in genomic DNA in vivo. We hypothesized that CSB may also play a role in cellular repair of the DNA helix-distorting tandem lesion (5`S)-8,5`-cyclo-2`-deoxyadenosine (S-cdA). Among many DNA lesions. S-cdA is unique in that it represents a concomitant damage to both the sugar and base moieties of the same nucleoside. Because of the presence of the C8-C5` covalent bond, S-cdA is repaired by nucleotide excision repair unlike most of other oxidatively induced lesions in DNA, which are subject to base excision repair. To test our hypothesis, we isolated genomic DNA from brain, kidney and liver of wild type and csb knockout (csb(-/-)) mice. Animals were not exposed to any exogenous oxidative stress before the experiment. DNA samples were analysed by liquid chromatography/mass spectrometry with isotope-dilution. Statistically greater background levels of S-cdA were observed in all three organs of csb(-/-) mice than in those of wild type mice. These results suggest the in vivo accumulation of S-cdA in genomic DNA due to lack of its repair in csb(-/-) mice. Thus, this study provides, for the first time, the evidence that CSB plays a role in the repair of the DNA helix-distorting tandem lesion S-cdA. Accumulation of unrepaired S-cdA in vivo may contribute to the pathology associated with CS. Published by Elsevier B.V.

Biodritin microencapsulated human islets of langerhans and their potential for type 1 diabetes mellitus therapy

Background. Microencapsulation of pancreatic islets with polymeric compounds constitutes an attractive alternative therapy for type 1 diabetes mellitus. The major limiting factor is the availability of a biocompatible and mechanically stable polymer. We investigated the potential of Biodritin, a novel polymer constituted of alginate and chondroitin sulfate, for islet microencapsulation. Methods. Biodritin microcapsules were obtained using an air jet droplet generator and gelated with barium or calcium chloride. Microencapsulated rat insulinoma RINm5F cells were tested for viability using the [3-(4,5-dimetyl-thiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide] [MTT] colorimetric assay. Microencapsulated rat pancreatic islets were coincubated with macrophages derived from mouse peritoneal liquid to assess the immunomodulatory potential of the microcapsules, using quantitative real time-PCR (qPCR). Biodritin biocompatibility was demonstrated by subcutaneous injection of empty microcapsules into immunocompetent Wistar rats. Insulin secretion by microencapsulated human pancreatic islets was evaluated using an electrochemoluminescent assay. Microencapsulated human islets transplanted into chemically induced diabetic mice were monitored for reversal of hyperglycemia. Results. The metabolic activity of microencapsulated RINm5F cells persisted for at least 15 days. Interleukin-1 beta expression by macrophages was observed during coculture with islets microencapsulated with Biodritin-CaCl2, but not with Biodritin-BaCl2. No statistical difference in glucose-stimulated insulin secretion was observed between nonencapsulated and microencapsulated islets. Upon microencapsulated islet transplantation, the blood glucose level of diabetic mice normalized; they remained euglycemic for at least 60 days, displaying normal oral glucose tolerance tests. Conclusion. This study demonstrated that Biodritin can be used for islet microencapsulation and reversal of diabetes; however, further investigations are required to assess its potential for long-term transplantation.

PILZ Protein Structure and Interactions with PILB and the FIMX EAL Domain: Implications for Control of Type IV Pilus Biogenesis

The PilZ protein was originally identified as necessary for type IV pilus (T4P) biogenesis. Since then, a large and diverse family of bacterial PilZ homology domains have been identified, some of which have been implicated in signaling pathways that control important processes, including motility, virulence and biofilm formation. Furthermore, many PilZ homology domains, though not PilZ itself, have been shown to bind the important bacterial second messenger bis(3`-> 5`)cyclic diGMP (c-diGMP). The crystal structures of the PilZ orthologs from Xanthomonas axonopodis pv Citri (PilZ(XAC1133), this work) and from Xanthomonas campestris pv campestris (XC1028) present significant structural differences to other PilZ homologs that explain its failure to bind c-diGMP. NMR analysis of PilZ(XAC1133) shows that these structural differences are maintained in solution. In spite of their emerging importance in bacterial signaling, the means by which NZ proteins regulate specific processes is not clear. In this study, we show that PilZ(XAC1133) binds to PilB, an ATPase required for TV polymerization, and to the EAL domain of FiMX(XAC2398), which regulates TV biogenesis and localization in other bacterial species. These interactions were confirmed in NMR, two-hybrid and far-Western blot assays and are the first interactions observed between any PilZ domain and a target protein. While we were unable to detect phosphodiesterase activity for FimXX(AC2398) in vitro, we show that it binds c-diGMP both in the presence and in the absence of PilZ(XAC1133). Site-directed mutagenesis studies for conserved and exposed residues suggest that PilZ(XAC1133) interactions with FimX(XAC2398) and PilB(XAC3239) are mediated through a hydrophobic surface and an unstructured C-terminal extension conserved only in PilZ orthologs. The FimX-PilZ-PilB interactions involve a full set of ""degenerate"" GGDEF, EAL and PilZ domains and provide the first evidence of the means by which PilZ orthologs and FimX interact directly with the TP4 machinery. (C) 2009 Elsevier Ltd. All rights reserved.

Co/Mg/Al hydrotalcite-type precursor, promoted with La and Ce, studied by XPS and applied to methane steam reforming reactions

Catalysts` precursor of Co/Mg/Al promoted with Ce and La were tested in the steam reforming of methane (SRM). The addition of promoters was made by anion-exchange. The oxides characterization was made by X-ray Photoelectron Spectroscopy (XPS) analysis that confirmed Co(2+) species in free form on surface and interacted with Mg and Al in the form of solid solution. In the SRM with high fed molar ratio of H(2)O:CH(4) = 4:1, the catalysts showed a great affinity with water and immediately deactivated by oxidation of the active sites. In the stoichiometric ratio of H(2)O:CH(4) = 2: 1 the catalysts were active and presented low carbon deposition during the time reaction tested. Also a test with low fed molar ratio H(2)O:CH(4) = 0.5:1 was carried out to evaluate the stability of the catalysts by CH(4) decomposition and all the catalysts were stable during 6 h of reaction. Promoted catalysts presented lower carbon deposition. (C) 2009 Elsevier B. V. All rights reserved.

Cobalt catalysts derived from hydrotalcite-type precursors applied to steam reforming of ethanol

Catalysts derived from Co/Mg/Al hydrotalcite-type precursors modified with La and Ce were characterized by XANES and tested in ethanol steam reforming. The reaction data showed that, with a molar ratio of water: ethanol = 3:1 in the feed, addition of Ce and La favored acetaldehyde production. Increasing the water content (water:ethanol = 5:1) decreased the acetaldehyde formation by favoring the adsorption of water molecules on these samples, enhancing the acetaldehyde conversion. (C) 2011 Elsevier B.V. All rights reserved.