Histological characterization of cellular types during Scinax fuscovarius oogenesis (Lutz) (Anura, Hylidae)

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

Surface morphology and optical characterization of OC1 OC6-PPV films

We report optical and morphological properties of poly(2-methoxy-5-hexyloxy-p-phenylenevinylene) (OC1OC6-PPV) films processed by casting, spin-coating (SC) and Langmuir-Blodgett (LB) techniques. The absorption spectra are practically the same, with an absorption maximum at approximately at 500 nm. For the photoluminescence (PL) spectra at low temperature (T=10K), a small but significant difference was noted in the cast film, in comparison with the LB and SC films. The zero-phonon transition shifted from 609 nm for the LB film to 615 and 621 nm for the SC and cast films, respectively. At room temperature, the PL spectra are similar for all films, and blue shifted by ca. 25 nm in comparison with the spectra at low temperature due to thermal disorder. Using atomic force microscopy (AFM) we inferred that the distinctive behavior of the cast film, probably associated with structural defects, is related to the large thickness of this film. The surface roughness, which was surprisingly higher for the LB film, apparently played no role in the emission properties of OC1OC6-PPV films.

A natural triploid in Trichomycterus davisi (Siluriformes, Trichomycteridae): mitotic and meiotic characterization by chromosome banding and synaptonemal complex analyses

Within a total of 50 analyzed specimens a male individual of Trichomycterus davisi has been recorded with 81 chromosomes including 60 metacentric, 18 submetacentric and three subtelocentric chromosomes. When compared with diploid individuals (2n = 54) and the morphological standard of chromosomes, this male is a triploid with 3 = 81 chromosomes. Since staining with silver nitrate indicates three active nucleolar organizer regions (NORs), the three NOR- bearing chromosomes in this individual are genetically active. Analysis of the synaptonemal complex (SC) by electronic microscopy shows that there is an incomplete pairing of the third set of chromosomes in the triploid individual.

Identification and characterization of Colletotrichum spp. affecting fruit after harvest in Brazil

Colletotrichum spp. cause anthracnose in various fruits post-harvest and are a particularly important problem in tropical and subtropical fruits. The disease in fruits of avocado, guava, papaya, mango and passion fruit has been reported to be caused by C. gloeosporioides, and in banana by C. musae. In subtropical and temperate crops such apple, grape, peach and kiwi, the disease is caused by C. acutatum. The variation in pathogenic, morphological, cultural and molecular characteristics of Brazilian isolates of Colletotrichum acutatum Simmonds and isolates from post-harvest decays of avocado, banana, guava, papaya, mango and passion fruit was evaluated. The fruits were inoculated with mycelium of C. acutatum, Colletotrichum spp. and C. musae on a disc of potato dextrose agar. The morphological, cultural and molecular characteristics studied were conidia morphology, colony growth at different temperatures, colony coloration and PCR with primers CaInt2 and ITS4 for C. acutatum and CgInt and ITS4 for C. gloeosporioides. C. acutatum was pathogenic to avocado, guava, papaya, mango and passion fruit, but it was not pathogenic to banana. The morphological, cultural and molecular studies indicated that the avocado, papaya, mango and passion fruit isolates were C. gloeosporioides. The natural guava isolate was identified as C. acutatum, which had not been found previously to produce anthracnose symptoms on guava in Brazil.

Characterization of the cellular component of polymorphous low-grade adenocarcinoma by immunohistochemistry and electron microscopy

In order to characterize the cellular component of the polymorphous low-grade adenocarcinoma (PLGA) of the salivary gland, a morphological and immunohistochemical study was carried out. Thirty cases of PLGA were studied by light microscopy and immunohistochemistry and five cases by transmission electron microscopy (TEM). The expression of cytokeratins (CKs) 7,8,10,13,14,18,19, vimentin and muscle-specific actin (MSA) was investigated through the streptavidin-biotin method. The majority of tumor cells stained for vimentin, CKs 8,18 and 7. CK 14 was positive in most cells of the papillary and trabecular sub-types. Although the expression of CKs 8,18 and 14 varied among the tumors sub-types, a straight relationship between each histologic pattern and the CK expression could not be delineated. MSA was reactive in only three tumors while CKs 10 and 13 were not detected in any tumor studied. The absence of MSA and the expression of CKs 8,18 and 7, in most of the tumor cells, lead to the hypothesis that myoepithelial cells are not the major cellular component of the PLGA. TEM revealed cells exhibiting microvilli and variable amounts of secretory granules, some of them suggesting an excretory activity. The presence of CKs 8, 18 and 7, added to the secretory granules, indicates that PLGA originates from cells located at the acinar-intercalated duct junction. (C) 1999 Elsevier B.V. Ltd. All rights reserved.

Characterization of PLGA microparticles as a drug carrier for 3-ethoxycarbonyl-2H-benzofuro[3,2-f]-1-benzopyran-2-one. Ultrastructural study of cellular uptake and intracellular distribution

Here we describe the application of microparticles (MPs) for the delivery and release of the drug a benzopsoralen. We also evaluated the intracellular distribution and cellular uptake of the drug by using an encapsulation technique for therapeutic optimization. MPs containing the compound 3-ethoxycarbonyl-2H-benzofuro[3,2-f]-1-benzopyran-2-one (psoralen A) were prepared by the solvent evaporation technique, and parameters such as particle size, drug encapsulation efficiency, effect of the encapsulation process on the drug's photochemistry, zeta potential, external morphology, and < i > in vitro release behavior were evaluated. The intracellular distribution of MPs as well as their uptake by tissues were monitored. Size distribution studies using dynamic ligh scattering and scanning electron microscopy revealed that the MPs are spherical in shape with a diameter of 1.4 mu m. They present low tendency toward aggregation, as confirmed by their zeta potential (+10.6 mV). The loading efficiency obtained was 75%. As a consequence of the extremely low diffusivity of the drug in aqueous medium, the drug release profile of the MPs in saline phosphate buffer (pH 7.4) was much slower than that obtained in the biological environment. Among the population of peritoneal phagocytic cells, only macrophages were able to phagocytose poly-d,l-lactic-co-glycolic acid (PLGA) MP. The use of psoralen A in association with ultraviolet light (360 nm) revealed morphological characteristics of cell damage such as cytoplasmic vesiculation, mitochondria condensation, and swelling of both the granular endoplasmatic reticulum and the nuclear membrane. These results indicate that PLGA MP could be a promising delivery system for psoralen in connection with ultraviolet irradiation therapy (PUVA).

Active planar waveguides based on sol-gel Er3+-doped SiO2-ZrO2 for photonic applications: Morphological, structural and optical properties

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

Structural and ultrastructural characterization of the embryonic development of Pseudoplatystoma spp. hybrids

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

Synthesis, Characterization, Anisotropic Growth and Photoluminescence of BaWO4

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Alternatives for the Treatment of Schistosomiasis: Physico-Chemical Characterization of an Inclusion Complex Between Praziquantel and Hydroxypropyl-beta-Cyclodextrin

"Alternatives for the Treatment of Schistosomiasis: Physico-Chemical Characterization of an Inclusion Complex Between Praziquantel and Hydroxypropyl-beta-Cyclodextrin". Praziquantel (PZQ) is the drug of choice commonly used for the treatment of shistosomiasis. However, it has low aqueous solubility, which could limit its bioavailability in the body. To circumvent these features, an inclusion complex with hydroxypropyl-beta-cyclodextrin (HP-beta-CD) was prepared. Thus, the objective of this work was to prepare and characterize the PZQ/HP-beta-CD inclusion complex. Morphological, spectroscopic, and calorimetric analysis showed the first signs of the guest/host interaction. The complexation kinetic analysis was used to determine the kinetic constant and, besides that, it was possible to establish the time consumed to reach equilibrium. Using the solubility isotherm, it was observed that the interaction with HP-beta-CD increased 2.4 fold the aqueous solubility of plain PZQ. In vitro cytotoxicity tests, using fibroblast cells, evidenced no toxicity for these cells at the concentrations tested. These results demonstrated that there is a potential use of PZQ in formulations with HP-beta-CD.

Early Development and Putative Primordial Germ Cells Characterization in Dogs

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

Micro-raman spectroscopic characterization of a CR-39 detector

Characterization by micro-Raman spectroscopy of polymeric materials used as nuclear track detectors reveals physico-chemical and morphological information on the material's molecular structure. In this work, the nuclear track detector poly(allyl diglycol carbonate), or Columbia Resin 39 (CR-39), was characterized according to the fluence of alpha particles produced by a 226Ra source and chemical etching time. Therefore, damage of the CR-39 chemical structure due to the alpha-particle interaction with the detector was analyzed at the molecular level. It was observed that the ionization and molecular excitation of the CR-39 after the irradiation process entail cleavage of chemical bonds and formation of latent track. In addition, after the chemical etching, there is also loss of polymer structure, leading to the decrease of the group density C-O-C (∼888 cm-1), CH=CH (∼960 cm -1), C-O (∼1110 cm-1), C-O-C (∼1240 cm -1), C-O (∼1290 cm-1), C-O (∼1741 cm -1), -CH2- (∼2910 cm-1), and the main band -CH2- (∼2950 cm-1). The analyses performed after irradiation and chemical etching led to a better understanding of the CR-39 molecular structure and better comprehension of the process of the formation of the track, which is related to chemical etching kinetics. Copyright © 2013 Society for Applied Spectroscopy.

Anatomopathological characterization of placentas from HIV+ patients associated with p24 expression

INTRODUCTION: The study of placentas from pregnant human immunodeficiency virus (HIV) positive women has become the subject of numerous studies in the literature. Morphological, viral, immune and inflammatory placental aspects have been analyzed in order to grasp the vertical transmission of the virus. OBJECTIVE: To identify the most frequent findings in the placentas by associating them with a viral antigen and correlating them with the infection of newborns. MATERIAL AND METHODS: Thirty-five placentas from HIV- positive pregnant women were pathologically and immunohistochemically analyzed with the use of p24 antibody in the period from 1992 to1997 in accordance with the routine laboratory testing from the Anatomopathological Department - Hospital Universitário Antônio Pedro - Universidade Federal Fluminense (APD/HUAP/UFF). RESULTS: The microscopic alterations detected in all cases, including those with vertical transmission, were arteriopathy in the fetal blood circulation, chorioamnionitis, perivillous fibrin deposition, syncytial knotting, villous edema and villous immaturity. No specific macroscopic or histopathological changes were found in these placentas. The neonatal infection was observed in five cases. Vertical transmission was identified in two out of five placentas that had low weight for the respective stage of pregnancy. Immunohistochemical analysis revealed 14 positive cases, two of which showed vertical transmission. The viral protein was not identified in 10 out of 14 placentas from patients who had been medicated with zidovudine (AZT). CONCLUSION: Our study has contributed to the anatomopathological investigation into placentas from HIV-positive patients, although p24 expression per se did not allow a definite and early diagnosis of the vertical transmission.

The genetic characterization of myrmelachista roger assemblages (hymenoptera: formicidae: formicinae) in the atlantic forest of southeastern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ethanolic extract of Mimosa caesalpiniifolia leaves: Chemical characterization and cytotoxic effect on human breast cancer MCF-7 cell line

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