Leaf anatomical and molecular studies in Bulbophyllum section Micranthae (Orchidaceae) and their implications for systematics

Bulbophyllum section Micranthae comprises 12 species of rupicolous or epiphytic orchids occurring in forests or in open rocky fields in Cerrado/Atlantic Forest ecotones throughout South America. We examined the leaf anatomy of 14 species and compared them with molecular data (nrITS) in phylogenetic analyses. The leaves of Bulbophyllum section Micranthae are characterised by uniseriate epidermis, with periclinal external cell wall thicker than the internal, presence of epicuticular wax, stomata present only on the abaxial surface with suprastomatic chambers, and collateral vascular bundles associated with sclerenchyma fibres. Some of these characters are shared with other rupicolous Orchidaceae species, demonstrating adaptive convergence in xeromorphic habitats. We found some anatomical characteristics with phylogenetic value. Bulbophyllum section Micranthae can be separated into two lineages: those with needle-like leaves, or flat leaves. The analyses show that anatomical characters as well as molecular data may contribute to the development of phylogenetic hypotheses. © 2013 Botanical Society of Sao Paulo.

Structural and Phylogenetic Studies with MjTX-I Reveal a Multi-Oligomeric Toxin - a Novel Feature in Lys49-PLA2s Protein Class

The mortality caused by snakebites is more damaging than many tropical diseases, such as dengue haemorrhagic fever, cholera, leishmaniasis, schistosomiasis and Chagas disease. For this reason, snakebite envenoming adversely affects health services of tropical and subtropical countries and is recognized as a neglected disease by the World Health Organization. One of the main components of snake venoms is the Lys49-phospholipases A2, which is catalytically inactive but possesses other toxic and pharmacological activities. Preliminary studies with MjTX-I from Bothrops moojeni snake venom revealed intriguing new structural and functional characteristics compared to other bothropic Lys49-PLA2s. We present in this article a comprehensive study with MjTX-I using several techniques, including crystallography, small angle X-ray scattering, analytical size-exclusion chromatography, dynamic light scattering, myographic studies, bioinformatics and molecular phylogenetic analyses.Based in all these experiments we demonstrated that MjTX-I is probably a unique Lys49-PLA2, which may adopt different oligomeric forms depending on the physical-chemical environment. Furthermore, we showed that its myotoxic activity is dramatically low compared to other Lys49-PLA2s, probably due to the novel oligomeric conformations and important mutations in the C-terminal region of the protein. The phylogenetic analysis also showed that this toxin is clearly distinct from other bothropic Lys49-PLA2s, in conformity with the peculiar oligomeric characteristics of MjTX-I and possible emergence of new functionalities inresponse to environmental changes and adaptation to new preys. © 2013 Salvador et al.

Clinical manifestations and experimental studies on the spine extract of the toadfish Porichthys porosissimus

Toadfish are fish from the family Batrachoididae that are found in marine and brackish environment around the world. Among the toadfish, Porichthys genus is very common, where Porichthys porosissimus, also called Atlantic Midshipman is found in Southwest Atlantic, from Rio de Janeiro, Brazil to eastern Argentina. There was no consensus about the classification of the genus Porichthys as venomous fish because so far there are no published Studies regarding human envenomations and/or toxic activities induced in animal models. Herein, we report two conclusive envenoming in human beings caused by P porosissimus spines, with clear signs and symptoms that were very important for the development of our experimental studies. We demonstrated that the P. porosissimus spine extract, now venom, can induce nociceptive and edematogenic responses in mice as well an induction of an inflammatory response elicited by intravital microscopy and leukocyte migration. Finally, we identified in the P. porosissimus spine extract, through analysis by mass spectrometry, the presence of proteins previously detected in the venoms of other fish species and other venomous animals. We believe that based on our studies we will dismiss the non-venomous nature of this fish and clarify this issue. (C) 2014 Elsevier Ltd. All rights reserved.

On the temperature stability of extracellular hemoglobin of Glossoscolex paulistus, at different oxidation states: SAXS and DLS studies

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

Encapsulation of Local Anesthetic Bupivacaine in Biodegradable Poly(DL-lactide-co-glycolide) Nanospheres: Factorial Design, Characterization and Cytotoxicity Studies

Local anesthetic agents cause temporary blockade of nerve impulses productiong insensitivity to painful stimuli in the area supplied by that nerve. Bupivacaine (BVC) is an amide-type local anesthetic widely used in surgery and obstetrics for sustained peripheral and central nerve blockade. in this study, we prepared and characterized nanosphere formulations containing BVC. To achieve these goals, BVC loaded poly(DL-lactide-co-glycolide) (PLGA) nanospheres (NS) were prepared by nanopreciptation and characterized with regard to size distribution, drug loading and cytotoxicity assays. The 2(3-1) factorial experimental design was used to study the influence of three different independent variables on nanoparticle drug loading. BVC was assayed by HPLC, the particle size and zeta potential were determined by dynamic light scattering. BVC was determined using a combined ultrafiltration-centrifugation technique. The results of optimized formulations showed a narrow size distribution with a polydispersivity of 0.05%, an average diameter of 236.7 +/- 2.6 nm and the zeta potential -2.93 +/- 1,10 mV. In toxicity studies with fibroblast 3T3 cells, BVC loaded-PLGA-NS increased cell viability, in comparison with the effect produced by free BVC. In this way, BVC-loaded PLGA-NS decreased BVC toxicity. The development of BVC formulations in carriers such as nanospheres could offer the possibility of controlling drug delivery in biological systems, prolonging the anesthetic effect and reducing toxicity.

Infection of commercial laying hens with Salmonella Gallinarum: clinical, anatomopathological and haematological studies

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

New palladium(II) complexes with pyrazole ligands Part II. Synthesis, spectral and thermal studies, and antitumor evaluation

This study describes the synthesis, IR, (1)H, and (13)C{(1)H} NMR spectroscopic as well the thermal characterization of the new palladium(II) pyrazolyl complexes [PdCl(2)(HmPz)(2)] 1, [PdBr(2)(HmPz)(2)] 2, [PdI(2)(HmPz)(2)] 3, [Pd(SCN)(2)(HmPz)(2)] 4 {HmPz = 4-methylpyrazole}. The residues of the thermal decomposition were identified as Pd(0) by X-ray powder diffraction. From the initial decomposition temperatures, the thermal stability of the complexes can be ordered in the sequence: 1 > 2 > 4 a parts per thousand 3. The cytotoxic activities of the complexes and the ligand were investigated against two murine cancer cell lines: mammary adenocarcinoma (LM3) and lung adenocarcinoma (LP07) and compared to cisplatin under the same experimental conditions.

New palladium(II) complexes with pyrazole ligands Part I. Synthesis, spectral and thermal studies, and antitumor evaluation

The pyrazole ligand 3,5-dimethyl-4-iodopyrazole (HdmIPz) has been used to obtain a series of palladium(II) complexes (1-4) of the type [PdX(2)(HdmIPz)(2)] {X = Cl(-) (1); Br(-) (2); I(-) (3); SCN(-) (4)}. All compounds have been isolated, purified, and characterized by means of elemental analysis, IR spectroscopy, (1)H and (13)C{(1)H}-NMR experiments, differential thermal analysis (DTA), and thermogravimetry (TG). The TG/DTA curves showed that the compounds released ligands in the temperature range 137-605 A degrees C, yielding metallic palladium as final residue. The complexes and the ligand together with cisplatin have been tested in vitro by MTT assay for their cytotoxicity against two murine cancer cell lines: mammary adenocarcinoma (LM3) and lung adenocarcinoma (LP07).

Ultrastructural and quantitative studies of hemocytes in the sugarcane borer, Diatraea saccharalis (Lepidoptera: Pyralidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Structural, electronic structure and magnetic studies of SmFe1-xNixO3 (x <= 0.5)

We present the structural, electronic structure and magnetic studies of Ni doped SmFeO3. The X-ray diffraction (XRD) studies confirm the single phase nature of the samples having orthorhombic Pbnm structure and the unit-cell volume is decreasing with the increase of Ni concentration. X-ray absorption spectroscopy (XAS) studies on O K. Fe L-3.2, Ni L-3.2 and Sm M-5.4 edges of SmFe1-xNixO3 (x <= 0.5) samples along with the reference compounds revealed the homo-valence state of Fe and Ni in these materials. From magnetization studies it has been observed the materials exhibit ferromagnetic and anti-ferromagnetic sub-lattices, which are strongly dependent on the thermo-magnetic state of the system. (C) 2010 Elsevier B.V. All rights reserved.

Structural, electronic structure and magnetic studies of GdFe1-xNixO3 (x <= 0.5)

The structural, electronic structure and magnetic properties of Ni doped GdFeO3 perovskite materials have been studied. A decreasing trend in volume with the increasing Ni concentration without any structural change is confirmed from X-ray diffraction studies. The electronic structural studies show that the competing ions within the ensemble have +3 oxidation states, which includes the Gd, Fe and Ni ions, and also confirms the octahedral symmetry of the Fe/Ni ions. The magnetic properties clearly depict that the Ni doping can tailor the phase transitions arising due to temperature/field dependence having a heavy impact on spin dynamics. (C) 2012 Elsevier B.V. All rights reserved.

Experimental and theoretical studies on the enhanced photoluminescence activity of zinc sulfide with a capping agent

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

Electrocatalysis of oxidation of hydrogen on platinum ordered intermetallic phases: Kinetic and mechanistic studies

An experimentally based kinetic and mechanistic study of the hydrogen oxidation reaction (HOR) on platinum and platinum ordered intermetallic materials in acid medium is presented. RDE kinetic data were re-evaluated and complemented by Tafel plots obtained from chronoamperometric measurements. Among the materials evaluated, PtSb and PtSn exhibited markedly improved kinetic current densities and exchange current densities, compared to Pt in the same experimental conditions. It is proposed that the intermetallic phase enhanced the adsorptive characteristic of the surface sites and, as a consequence, improved the kinetics of the adsorption steps (Tafel or Heyrovsky) of the mechanism involved. (c) 2006 Published by Elsevier B.V.

Synthesis, characterization and thermal studies on solid 3-methoxybenzoate of some bivalent transition metal ions

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