Identificação e fatores de virulência de Candida spp isoladas da cavidade bucal de transplantados renais do hospital universitário Onofre Lopes em Natal-RN

Despite Candida species are often human commensals isolated from various oral sites such as: tongue, cheek and palatal mucosa plus subgingival region, there are some properties linked to the organism commonly known as virulence factors which confer them the ability to produce disease. Oral candidiasis is one of the main oral manifestations reported in literature related to kidney transplant patients. The objectives of the present study were to identify and investigate virulence factors of yeasts isolated from the oral cavity of kidney transplant recipients admitted at the Hospital Universitário Onofre Lopes, in Natal RN. Seventy Candida species isolated from 111 kidney transplant recipients were investigated in this study. Identification of the isolates was performed by using the evidence of germ tube formation, hypertonic broth, tolerance to grow at 42°C, micromorphology and biochemical profiles. We observed a high rate of isolation of yeasts from the oral cavity of kidney transplant recipients (63.1%) being C. albicans was the most prevalent species. Oral candidiasis was diagnosed in 14.4% of transplant recipients. We evaluated virulence properties of the isolates regarding to: biofilm formation on polystyrene microplates as well as XTT reduction, adherence to acrylic resin and human buccal epithelial cells and proteinase activity. Most isolates were able to form biofilm by the method of adhesion to polystyrene. All isolates of Candida spp. remained viable during biofilm formation when analyzed by the method of XTT reduction. The number of CFU attached to the acrylic resin suggested high adherence for C. parapsilosis. C. albicans isolates showed higher median adherence to human buccal epithelial cells than non-C. albicans Candida isolates. Nevertheless, this difference was not statistically significant. C. dubliniensis showed low ability to adhere to plastic and epithelial cells and biofilm formation. Proteolytic activity was observed for all the isolates investigated, including the unique isolate of C. dubliniensis. There was a statistically significant association between proteinase production and the presence of oral candidiasis. Studies related to oral candidiasis in renal transplant recipients are limited to clinical and epidemiological data, but investigations concerning Candida spp. virulence factor for this group of individuals are still scarce. We emphasize the importance of studies related to virulence factors of yeasts isolated from this population to contribute to the knowledge of microbiological aspects of oral candidiasis

The influence of temperature of three adhesive systems on bonding to ground enamel

This study evaluated the microtensile bond strength test (mu T), micromorphology of resin-enamel interface (RET) and etching patterns (EP) promoted by the etch-and-rinse adhesive, Prime&Bond NT (PB), and two self-etching adhesives, Clearfil SE Bond (SE) and Adper Prompt L-Pop (APR), to ground bovine enamel surfaces' when applied at temperatures of 5 degrees C (C), 40 degrees C (H) and 20 degrees C (R). Materials and Methods. Sixty-three bovine incisors were randomly divided into nine experimental groups (n=7) according to adhesive systems and temperatures. The buccal enamel surfaces were flattened with 600-grit SiC paper and abraded with a diamond bur under water-cooling. The adhesive systems were applied according to the manufacturer's instructions. After the restorative procedures, the specimens were sectioned into five slabs. Four slabs were prepared for mu T and one for interface analysis. For etching pattern analysis, the remaining 16 bovine enamel fragments were used (n=2). The adhesives were applied and the surfaces were rinsed with organic solvents after application. The specimens for RET and EP analysis were prepared for SEM analysis. Results. No significant differences among the adhesives were found at R temperature. However, at 5 degrees C, PB and APR presented lower bond strength than SE. At H temperature, higher bond strength was observed for PB than for APR and SE. At C and H temperature, formation of the interdiffusion zone was impaired and the treated enamel surfaces presented an undefined EP.

Micromorphologic assessment of CVD (chemical vapor deposition) and conventional diamond tips and their cutting effectiveness

The aim of this study was to compare the micromorphology of CVD diamond tips coupled to ultrasound with conventional high speed diamond tips after cavity preparations, and to measure the width and depth of the cavities obtained. Two hundred bovine teeth were divided into 20 subgroups. Each of the diamond tips (10 CVD and 10 conventional) were used to prepare 10 standardized cavities, using an apparatus that controlled the time (t: 27 s), speed (5.3 mm/s) and load (0.012 KGF) of the tip against the teeth during preparation. The unused and the used (after one, five and 10 preparations) tips were analyzed by scanning electronic microscopy. The images were randomly assessed by 3 examiners with regard to the presence or absence of micromorphologic alterations. Cavity measurements were made after visualization under a stereoscopic microscope. Cavity widths and depths were analyzed by the ANOVA Factorial test (p < 0.05). The CVD diamond tips presented less wear than the conventional tips after all the cavity preparations performed, but produced shallower cavities that were equivalent in width to those made by conventional tips after the fifth preparation. CVD diamond tips may be suggested as an alternative to conventional diamond tips due to their conservative preparation and greater longevity.

Multiple pleurograms in Chamaecrista moench (Leguminosae, caesalpinioideae)

According to the literature, the seeds of Chamaecrista lack pleurograms and have pitted testas aligned in vertical lines. Preliminary observations have revealed that these small structures consist of superficial alterations of the testa that are coloured differently to the rest of the seed coat and stand out as pits. However, no anatomical inspection has yet determined the precise composition of these pits. The present work examined the morphology, surface micromorphology, anatomy, and histochemistry of the seed coat of mature seeds of C. desvauxii var. latistipula, C. flexuosa, and C. nictitans var. patellaria in order to elucidate the structural nature of the seed coat pits. For this, seed coats were studied using scanning electron microscopy and light microscopy. Structural modifications were examined in the seed coats of the studied species, and variations were noted in the mucilaginous layer, in the thickness of the palisade layer, and in the presence of larger hypodermic cells. Based on the anatomical features observed, and comparing these with published data on pleurograms in the Caesalpinioideae, it was determined that the structures referred to previously as tegumental pits on Chamaecrista seeds are actually small and numerous pleurograms, reported here for the first time. (c) 2008 The Linnean Society of London.

A macro- and micromorphological survey of floral and extrafloral nectaries in the epiphytic cactus Rhipsalis teres (Cactoideae: Rhipsalideae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Roughness of Human Enamel Surface Submitted to Different Prophylaxis Methods

The purpose of this in vitro study was to evaluate alterations in the surface roughness and micromorphology of human enamel submitted to three prophylaxis methods. Sixty-nine caries-free molars with exposed labial surfaces were divided into three groups. Group I was treated with a rotary instrument set at a low speed, rubber clip and a mixture of water and pumice; group II with a rotary instrument set at a low speed, rubber cup and prophylaxis paste Herjos-F (Vigodent S/A Industria e Comercio, Rio de Janeiro, Brazil); and group III with sodium bicarbonate spray Profi II Ceramic (Dabi A dante Indtistrias Medico Odontologicas Ltda, Ribeirao Preto, Brazil). All procedures were performed by the same operator for 10 s, and samples were rinsed and stored in distilled water. Pre and post-treatment surface evaluation was completed using a surface profilometer (Perthometer S8P Marh, Perthen, Germany) in 54 samples. In addition, the other samples were coated with gold and examined in a scanning electron microscope (SEM). The results of this study were statistically analyzed with the paired t-test (Student), the Kruskal-Wallis test and the Dunn (5%) test. The sodium bicarbonate spray led to significantly rougher surfaces than the pumice paste. The use of prophylaxis paste showed no statistically significant difference when compared with the other methods. Based on SEM analysis, the sodium bicarbonate spray presented an irregular surface with granular material and erosions. Based on this study, it can be concluded that there was an increased enamel stuface roughness when teeth were treated with sodium bicarbonate spray when compared with teeth treated with pumice paste.

Gênese de solos derivados de rochas ultramáficas serpentinizadas no sudoeste de Minas Gerais

Os solos derivados de rochas serpentinizadas ou serpentinitos constituem um grupo especial de solos em toda superfície terrestre. de caráter ultramáfico, ou seja, rochas com mais de 70 % de minerais máficos (ferromagnesianos), os serpentinitos apresentam uma mineralogia pobre em sílica e escassa em Al, sendo, no entanto, muito enriquecida em Mg. São poucos os estudos sobre a morfologia, mineralogia, gênese e classificação dos solos desenvolvidos de tais rochas. em ambiente tropical úmido no sudoeste de Minas Gerais, na zona do greenstone belt do Morro de Ferro, em superfícies geomórficas jovens, três perfis de solos representativos dessa paisagem sobre rochas serpentinizadas foram caracterizados por meio de descrições macro e micromorfológicas, análises granulométricas, químicas e por mineralogia de raios X das frações argila e silte. Complementarmente, para acompanhamento da alteração geoquímica dos horizontes do solo, foram feitas microanálises das seções delgadas por EDRX. Os solos foram classificados como Chernossolo Háplico Férrico típico, Cambissolo Háplico eutroférrico léptico e Neossolo Regolítico eutrófico típico e, embora situados num clima que favorece o rápido intemperismo, do ponto de vista morfológico e mineralógico, mostraram-se similares aos solos derivados de rochas serpentinizadas das regiões subtropicais e temperada. No processo de formação de solo, a evolução da trama segue a seguinte seqüência: alteração da rocha ® trama frâgmica ® trama porfírica com cavidades ® trama porfírica aberta por coalescência de cavidades. O processo de argiluviação é evidente e se dá em dois estádios distintos: argiluviação primária, que ocorre nas fendas e cavidades que se formam por alteração de rocha, e argiluviação secundária, verificada na porosidade mais aberta e evoluída da coalescência das cavidades. Os solos apresentam mineralogia pouco comum para solos tropicais, com presença de minerais primários de fácil decomposição até mesmo na fração argila, com destaque para o talco, clorita trioctaedral e ocorrência limitada de tremolita, sendo esta última abundante na fração silte. Óxidos de Fe, caulinita e os interestratificados de clorita-esmectita e de clorita-vermiculita completam a assembléia mineralógica. A tendência de evolução é para B textural ou para B nítico com mineralogia 1:1 e alto conteúdo de óxidos de Fe. Nas fases iniciais de alteração, os alteromorfos já apresentam composição química similar aos agregados do solo, com forte perda de Mg, Ca e Si e acúmulo relativo de Al e Fe. Nas três situações estudadas, ocorreu um rejuvenescimento superficial por erosão diferencial, que acumulou material grosseiro e removeu os finos, contribuindo para o incremento da relação textural.

Qualidade de um sistema latossolo-argissolo como receptor de efluentes no município de Lins(SP)

Este trabalho objetivou caracterizar um sistema de solos, evidenciando a propriedades que possam esclarecer sua dinâmica e contribuir para a definição de critérios que condicionem a aptidão destes solos como receptores de efluentes. Trata-se de uma área experimental de estudos, contígua à Estação de Tratamento de Esgoto do município de Lins (SP), onde o efluente é gerado a partir do tratamento de esgoto por sistema de lagoas de estabilização. Os solos, situados ao longo de uma vertente com ligeira inclinação, foram caracterizados por meio de análises, morfológica, granulométrica, química, mineralógica e micromorfológica, realizadas em amostras coletadas em cinco trincheiras em toposseqüência. Os solos são desenvolvidos a partir dos sedimentos arenosos da Formação Adamantina (Grupo Bauru) e constituem um sistema Latossolo - Argissolo onde a transição Bw - Bt ocorre lateralmente do topo para a base da vertente. Foram identificadas três fases pedogenéticas nesta associação de solos. A primeira, argiluviação e adensamento de partículas, responsável pela formação dos horizontes texturais, foi superposta pelos processos de latossolização e hidromorfismo, atuantes na dinâmica atual destes solos. Análises micromorfológicas mostraram tratar-se de solos com intensa porosidade, caracterizada pelo empilhamento dos grãos do esqueleto quartzoso amplamente predominante e pelo arranjo entre os microagregados granulares. A permeabilidade é ainda favorecida pela intensa ação da mesofauna. Os solos são distróficos e compostos por caulinita e óxidos de Fe na fração argilosa. Por constituírem um sistema frágil, a disposição de quaisquer tipos de resíduos nestes solos requer o monitoramento constante de suas propriedades, tanto para a manutenção, quanto para a recuperação da qualidade desta cobertura pedológica.

Micromorfologia do solo e sua relação com atributos físicos e hídricos

O objetivo deste trabalho foi avaliar a relação entre atributos micromorfológicos e físicos de um Latossolo Vermelho eutroférrico, sob cultivo de cana-de-açúcar. As amostras de solo foram coletadas nos pontos de cruzamento de uma malha, com intervalos regulares de 10 m, perfazendo um total de 100 pontos, nos horizontes A1 e AB. Os altos valores da densidade do solo, microporosidade e resistência do solo à penetração, e os baixos valores da macroporosidade, porosidade total e condutividade hidráulica do solo saturado, principalmente no horizonte AB, indicaram compactação confirmada pela análise de imagens (micromorfologia).

Isolation of Malassezia pachydermatis and M. sympodialis from the external ear canal of cats with and without otitis externa

The objective of this study was to determine the presence of Malassezia spp. in the external ear canal of cats with and without otitis. Forty-five animals were studied, 20 with and 25 without otitis externa (OE). Cerumen or secretion from external ear canal samples was cultured on modified Mycosel agar and sterile olive oil was added to the surface of the medium before specimen seeding. The isolates were analysed for macro- and micromorphology and identified by catalase tests and on the basis of growth on Tween 20, 40, 60 and 80. Malassezia spp. were isolated from 15 out of 20 (75%) animals with otitis and from 7 out of 25 (28%) cats without OE; the difference between the two groups was statistically significant (P <= 0.05). Malassezia pachydermatis and M. sympodialis were isolated from 60% (12/20) and 40% (8/20) of cats with otitis, respectively, with no significant difference in the frequency of isolation between the two species. In the microflora of the healthy ear canal M pachydermatis was significantly more common (6/25, 24%) than M sympodialis (1/25, 4%). The present investigation confirms that M sympodialis can also act as an actiological agent of feline OE, and if commercial veterinary laboratories do not use media with added lipids for the isolation of Malassezia spp., this might lead to false-negative results.

Morphology and histoenzymology of eosinophilic granulocytes in the circulating blood of the turtle (Chrysemys dorbignih)

The studies on the characterization of eosinophils and neutrophils/ heterophils of turtles are contradictory. Some authors have pointed out the existence of two distinct cell types: eosinophils and heterophils. Other authors have proposed that eosinophils and heterophils may be the same cells in different stages of maturation. These interpretations are based only on a morphological analysis. In the blood of the turtle (Chrysemys dorbignih), a South American freshwater species, there are two types of granulocytes with eosinophilic staining pattern: the first with round cytoplasmic granules and the second with ellipsoidal cytoplasmic granules. In the present study by using histoenzymological methods for the analyses of enzymological cellular content, we found that the cells with round cytoplasmic granules were positive for nonspecific esterase and the cells with ellipsoidal granules were positives for acid phosphatase, alkaline phosphatase, nonspecific esterase and peroxidase. The results show that these cells are distinct cells and that the cells with ellipsoidal cytoplasmic granules have the same histoenzymological characteristics as the neutrophils/heterophils of mammalians and other vertebrates.

Mouse extensor digitorum longus and soleus show distinctive ultrastructural changes induced by veratrine

We investigated whether veratrine (5 μl, 10 ng/kg) injected into the mouse extensor digitorum longus (EDL) (fast-twitch) and soleus (SOL) (slow-twitch) muscles provokes distinctive ultrastructural disturbances 15, 30 and 60 min later. The mitochondria in SOL were affected earlier (within 15 min) than in EDL. Swelling of the sarcoplasmic reticulum terminal cisternae was more marked in EDL than in SOL and caused distortion of sarcomeres so that fragmentation of myofilaments was more pronounced in EDL. Hypercontracted sarcomeres were seen mainly in SOL and veratrine caused infoldings of the sarcolemma only in this muscle. In both muscles, the T-tubules remained unaffected and by 60 min after veratrine most of the above alterations had reverted to normal. Pretreatment with tetrodotoxin prevented the alterations induced by veratrine. This suggests that most of the alterations resulted from the enhanced influx of Na+ into muscle fibers. These results emphasize the importance of considering the type of muscle when studying the action of myotoxic agents.

The thrombocyte aggregation process in the turtle Phrynopys hilarii (Chelonia). An ultrastructural study

This study investigates the thrombocyte aggregation process in the South American fresh water turtle (Phrynopys hilarii) using electron microscopy. Blood was taken from surgically exposed lateral neck vessels often turtles Phrynopys hilarii during the spring and summer seasons, when the mean temperature is 37°C. Blood samples were fixed with Karnovsky solution for processing by transmission electron microscopy. The turtle thrombocytes were spindle-shaped with lobulated nuclei. Prominent vesicles and canaliculi were found throughout the cytoplasm. The cytoplasm organelles showed an agranular endoplasmatic reticulum, Golgi complex near the centrioles and scattered free ribosomes. These cells are similar to bird thrombocytes but distinct from fish and frog thrombocytes. Blood clotting time was 5 min ± 30 sec measured by the Lee and White method. Structural alterations resulting from the aggregation process occurred after activation. Thrombocytes developed numerous filopodial projections, an increased number of vacuoles and changed from spindle to spherical shape. P. hilarii thrombocytes have different morphologic characteristics compared to other non-mammalian vertebrate cells. These cells can participate in the aggregation process, as observed in birds.

Is the number of antennal plate organs (sensilla placodea) greater in hygienic than in non-hygienic Africanized honey bees?

Hygienic behavior is a desirable trait in honey bees (Apis mellifera L.), as hygienic bees quickly remove diseased brood, intermpting the infectious cycle. Hygienic lines of honey bees appear to be more sensitive to the odors of dead and diseased honey bee brood, and Africanized honey bees are generally more hygienic than are European honey bees. We compared the number of sensilla placodea, antennal sensory structures involved in the perception of odor, in 10 bees from each of six hygienic and four non-hygienic colonies of Africanized honey bees. The sensilla placodea of three of the terminal segments (flagellomeres) of the right antenna of each bee were counted with a scanning electron microscope. There were no significant differences in the mean numbers of sensilla placodea between the hygienic and non-hygienic bees, though the variance was higher in the hygienic group. Flagellomere 4 had significantly more sensilla placodea than flagellomeres 6 and 8. However, there was no significant difference between the other two flagellomeres. As hygienic bees are capable of identifying dead, injured, or infested brood inside a capped brood cell, sensilla placodea probably have an important role in enabling worker bees to sense sick brood. However, we did not find greater numbers of this sensory structure in the antennae of hygienic, compared to non-hygienic Africanized honey bees.

Characterization and environmental interpretation of a floodplain Holocene paleosoil: Implications for paleohydrological reconstructions in the Upper Paraná River, Brazil

Alluvial paleosoil horizons from the 3 to 4 m high banks of the Paraná River were used to reconstruct the palaeoenvironmental history and palaeohydrological regime of the river. The bank consists of a Middle to Late Holocene sequence of sandy to silty clay layers of overbank deposits. The paleosoil horizon is located to a depth of 1.95 m from the top of the bank and is recognized as a guide horizon throughout the floodplain of the Upper Paraná River floodplain. Analyses of organic matter (δ13C and humic/fulvic acids), palynology (pollen and charcoal fragments), magnetic susceptibility, micromorphology, x-ray diffraction and 14C dating were conducted for samples from two representative profiles of the study area. Two phases were characterized in the history of the river: 1) An older phase, of stability in fluvial hydrology (stasis) with low frequency of floods, which produced conditions for soil development (14C 1700 ± 70 yr. BP). At this period, the predominance of herbaceous vegetation (determinated by pollen and δ13C analyses) suggests a climate less humid than the present one, and 2) A second phase, when climate changed to the present conditions of humidity (annual rain fall of 1600 rum) and characterized by the predominance of C3 plants. Under this new hydrological regime, the river developed an agradational floodplain, with a depositional sedimentary rate of 1.2 mm.y-1. © 2006 Gebrüder Borntraeger.