RESUMO
Magnetic antiperovskites, having chiral noncollinear antiferromagnetic ordering, have shown remarkable properties that range from negative thermal expansion to anomalous Hall effects. Nevertheless, details on the electronic structure, related to the oxidation states and the octahedral center's site effects, are still scarce. Here, we show a theoretical study, based on first-principles calculations in the framework of density-functional theory (DFT), on the electronic properties associated with the nitrogen site effects on the structural, electronic, magnetic, and topological degrees of freedom. Thus, we show that the nitrogen vacancy increases the value of the anomalous Hall conductivity and retains the chiral Γ4g antiferromagnetic ordering. Moreover, we reveal, based on the Bader charges and the electronic structure analysis, the negative and positive oxidation states of the Ni- and Mn-sites, respectively. This is in agreement with the expected A3α+Bß-Xδ- oxidation states to satisfy charge neutrality in antiperovskites, but the negative charge is rare for transition metals. Finally, we extrapolate our findings on the oxidation states to several Mn3BN compounds, showing that the antiperovskite structure is an ideal platform to encounter negative oxidation states for metals sitting at the corner B-sites.
RESUMO
Oxynitride perovskites of the type ABO2N have attracted considerable attention thanks to their potential ferroelectric behavior and tunable bandgap energy, making them ideal candidates for photocatalysis processes. Therefore, in order to shed light on the origin of their ferroelectric response, here we report a complete analysis of the structural and vibrational properties of SrNbO2N and SrTaO2N oxynitrides. By employing first-principles calculations, we analyzed the symmetry in-equivalent structures considering the experimentally reported parent I4/mcm space group (with a phase a0a0c- in Glazer's notation). Based on the I4/mcm reference within the 20-atoms unit-cell, we found and studied the ensemble of structures where different octahedral anionic orderings are allowed by symmetry. Thus, by exploring the vibrational landscape of the cis- and trans-type configuration structures and supported by the ionic eigendisplacements and the Born effective charges, we explained the mechanism responsible for the appearance of stable ferroelectric phases in both anionic orderings. The latter goes from covalent-driven in the trans-type ordering to the geometrically-driven in the cis-type configuration. Finally, we found in both cases that the biaxial xy epitaxial strain considerably enhances such ferroelectric response.
RESUMO
Abstract The present paper addresses the feeding activity of Trachinotus cayennensis, collected in Lençóis Bay (1°18'S - 1°19'S; 44°51'W - 44°53'W) on the western coast of the state of Maranhão, Brazil. Sampling was conducted between June 2012 and June 2013 using driftnets with stretch mesh sizes from 95 to 100 mm. A total of 205 individuals (114 females and 91 males) were analyzed. Statistically significant differences in the sex ratio were found in June, September and December 2012. Food items were analyzed based on frequency of occurrence and volumetric method, with the subsequent calculation of the alimentary importance index. Three size groups were defined to determine possible ontogenetic changes in eating habits based on the size range of the individuals collected: I (˂ 29 cm), II (29.1 to 37.0) and III (≥ 37.1). Eleven food item categories were identified: mollusks, polychaetes, crustaceans, nematodes, insects, algae, bryozoans, ophiuroids, fishes, vegetal matter and sediments. The variety of items in the diet of T. cayennensis indicates considerable feeding plasticity and opportunistic behavior. Seasonal variations influenced the feeding pattern of the species, with greater feeding activity in the dry season. The considerable availability of resources in estuarine habitats of the western coast of Maranhão constitutes another factor that influences the feeding behavior of this species.
Resumo Atividade alimentar do pampo Trachinotus cayennensis (Cuvier 1832) (Perciformes, Carangidae) em estuários na costa ocidental do Maranhão, Brasil. O presente trabalho descreve a atividade alimentar do Trachinotus cayennensis , coletado na Baía de Lençóis (1°18'S - 1°19'S; 44°51'W - 44°53'W) na costa oeste do Maranhão. Amostragens foram realizadas entre junho de 2012 e junho de 2013, utilizando redes de emalhar à deriva com tamanho de malha de 95 a 100 mm. Foram analisados 205 indivíduos (114 fêmeas e 91 machos). Encontraram-se diferenças estatisticamente significativas na proporção sexual nos meses de junho, setembro e dezembro de 2012. Os itens alimentares foram analisados com base na frequência de ocorrência e utilizando o método volumétrico, com o subsequente cálculo do índice de importância alimentar. Três grupos de tamanho foram definidos para determinar possíveis mudanças ontogenéticas nos hábitos alimentares com base na faixa de tamanho dos indivíduos coletados: I (˂ 29 cm), II (29,1 a 37,0) e III (≥ 37,1). Foram identificadas 11 categorias de alimentos: moluscos, poliquetas, crustáceos, nematoides, insetos, algas, briozoários, ophiuro, peixes, matéria vegetal e sedimentos. A variedade de itens na dieta de T. cayennensis indica uma plasticidade alimentar considerável e um comportamento oportunista. As variações sazonais influenciaram o padrão alimentar da espécie, com maior atividade de alimentação na estação seca. A considerável disponibilidade de recursos nos habitats estuarinos da costa oeste do Maranhão constitui outro fator que exerce influência sobre o comportamento alimentar desta espécie.
Assuntos
Animais , Masculino , Feminino , Perciformes/fisiologia , Comportamento Alimentar/fisiologia , Brasil , EstuáriosRESUMO
The present paper addresses the feeding activity of Trachinotus cayennensis, collected in Lençóis Bay (1°18'S - 1°19'S; 44°51'W - 44°53'W) on the western coast of the state of Maranhão, Brazil. Sampling was conducted between June 2012 and June 2013 using driftnets with stretch mesh sizes from 95 to 100 mm. A total of 205 individuals (114 females and 91 males) were analyzed. Statistically significant differences in the sex ratio were found in June, September and December 2012. Food items were analyzed based on frequency of occurrence and volumetric method, with the subsequent calculation of the alimentary importance index. Three size groups were defined to determine possible ontogenetic changes in eating habits based on the size range of the individuals collected: I (Ë 29 cm), II (29.1 to 37.0) and III (≥ 37.1). Eleven food item categories were identified: mollusks, polychaetes, crustaceans, nematodes, insects, algae, bryozoans, ophiuroids, fishes, vegetal matter and sediments. The variety of items in the diet of T. cayennensis indicates considerable feeding plasticity and opportunistic behavior. Seasonal variations influenced the feeding pattern of the species, with greater feeding activity in the dry season. The considerable availability of resources in estuarine habitats of the western coast of Maranhão constitutes another factor that influences the feeding behavior of this species.
Assuntos
Comportamento Alimentar/fisiologia , Perciformes/fisiologia , Animais , Brasil , Estuários , Feminino , MasculinoRESUMO
The present paper addresses the feeding activity of Trachinotus cayennensis, collected in Lençóis Bay (1°18S 1°19S; 44°51W 44°53W) on the western coast of the state of Maranhão, Brazil. Sampling was conducted between June 2012 and June 2013 using driftnets with stretch mesh sizes from 95 to 100 mm. A total of 205 individuals (114 females and 91 males) were analyzed. Statistically significant differences in the sex ratio were found in June, September and December 2012. Food items were analyzed based on frequency of occurrence and volumetric method, with the subsequent calculation of the alimentary importance index. Three size groups were defined to determine possible ontogenetic changes in eating habits based on the size range of the individuals collected: I ( 29 cm), II (29.1 to 37.0) and III ( 37.1). Eleven food item categories were identified: mollusks, polychaetes, crustaceans, nematodes, insects, algae, bryozoans, ophiuroids, fishes, vegetal matter and sediments. The variety of items in the diet of T. cayennensis indicates considerable feeding plasticity and opportunistic behavior. Seasonal variations influenced the feeding pattern of the species, with greater feeding activity in the dry season. The considerable availability of resources in estuarine habitats of the western coast of Maranhão constitutes another factor that influences the feeding behavior of this species.(AU)
Atividade alimentar do pampo Trachinotus cayennensis (Cuvier 1832) (Perciformes, Carangidae) em estuários na costa ocidental do Maranhão, Brasil. O presente trabalho descreve a atividade alimentar do Trachinotus cayennensis , coletado na Baía de Lençóis (1°18S 1°19S; 44°51W 44°53W) na costa oeste do Maranhão. Amostragens foram realizadas entre junho de 2012 e junho de 2013, utilizando redes de emalhar à deriva com tamanho de malha de 95 a 100 mm. Foram analisados 205 indivíduos (114 fêmeas e 91 machos). Encontraram-se diferenças estatisticamente significativas na proporção sexual nos meses de junho, setembro e dezembro de 2012. Os itens alimentares foram analisados com base na frequência de ocorrência e utilizando o método volumétrico, com o subsequente cálculo do índice de importância alimentar. Três grupos de tamanho foram definidos para determinar possíveis mudanças ontogenéticas nos hábitos alimentares com base na faixa de tamanho dos indivíduos coletados: I ( 29 cm), II (29,1 a 37,0) e III ( 37,1). Foram identificadas 11 categorias de alimentos: moluscos, poliquetas, crustáceos, nematoides, insetos, algas, briozoários, ophiuro, peixes, matéria vegetal e sedimentos. A variedade de itens na dieta de T. cayennensis indica uma plasticidade alimentar considerável e um comportamento oportunista. As variações sazonais influenciaram o padrão alimentar da espécie, com maior atividade de alimentação na estação seca. A considerável disponibilidade de recursos nos habitats estuarinos da costa oeste do Maranhão constitui outro fator que exerce influência sobre o comportamento alimentar desta espécie.(AU)
Assuntos
Animais , Perciformes/metabolismo , Ingestão de Alimentos , Cadeia AlimentarRESUMO
Herewith, first-principles calculations based on density functional theory are used to describe the ideal magnetization reversal through polarization switching in BaCuF_{4} which, according to our results, could be accomplished close to room temperature. We also show that this ideal coupling is driven by a single soft mode that combines both polarization, and octahedral rotation. The later being directly coupled to the weak ferromagnetism of BaCuF_{4}. This, added to its strong Jahn-Teller distortion and its orbital ordering, makes this material a very appealing prototype for crystals in the ABX_{4} family for multifunctional applications. The described mechanism behaves ideally as it couples the ferroelectric and the magnetic properties naturally and it has not been reported previously.
RESUMO
Geometrical and vibrational characterization of magnesium hydroxide was performed using density functional theory. Four possible crystal symmetries were explored: P3[combining macron] (No. 147, point group -3), C2/m (No. 12, point group 2), P3m1 (No. 156, point group 3m) and P3[combining macron]m1 (No. 164, point group -3m) which are the currently accepted geometries found in the literature. While a lot of work has been performed on Mg(OH)2, in particular for the P3[combining macron]m1 phase, there is still a debate on the observed ground state crystal structure and the anharmonic effects of the OH vibrations on the stabilization of the crystal structure. In particular, the stable positions of hydrogen are not yet defined precisely, which have implications in the crystal symmetry, the vibrational excitations, and the thermal stability. Previous work has assigned the P3[combining macron]m1 polymorph as the low energy phase, but it has also proposed that hydrogens are disordered and they could move from their symmetric position in the P3[combining macron]m1 structure towards P3[combining macron]. In this paper, we examine the stability of the proposed phases by using different descriptors. We compare the XRD patterns with reported experimental results, and a fair agreement is found. While harmonic vibrational analysis shows that most phases have imaginary modes at 0 K, anharmonic vibrational analysis indicates that at room temperature only the C2/m phase is stabilized, whereas at higher temperatures, other phases become thermally competitive.
RESUMO
O estudo dos dados anatômicos é fundamental para possibilitar ao médico veterinário o reconhecimento de pequenas estruturas, como os nervos nos animais, oferecendo subsídio para construção do conhecimento do profissional principalmente em técnicas anestésicas e cirúrgicas. Para investigar e mapear os nervos do plexo braquial (nervo radial, nervo musculocutâneo, nervo ulnar, nervo mediano), nervo isquiático, nervo tibial, nervo femoral e os nervos para bloqueio paravertebral, foram utilizados um cadáver canino adulto, de peso aproximado de 8kg, e um cadáver de bezerro Holandês, de peso aproximado de 40kg. O mapeamento dos nervos é de grande importância, já que conhecer bem essas estruturas permite ao veterinário um bom desenvolvimento de suas atividades profissionais a fim de exercer funções mais complexas durante a anestesia e cirurgia veterinária, uma vez que, identificados os pontos de referência anatômicos, é possível trabalhar com mais clareza nas técnicas de bloqueios dos nervos periféricos.(AU)
Knowledge of animal anatomy is essential for the veterinarian to identify small structures such as nerves, thus providing a solid background for the professional especially for surgical and anesthetic techniques. To investigate and map the nerves of the brachial plexus (radial, musculocutaneous, ulnar, median), sciatic, tibial, femoral and the nerves for paravertebral blocking in bovine, embalmed specimens were used. One adult male dog weighing approximately 8kg and one 40kg male calf were used. Nerve mapping is fundamental due to its interdisciplinary nature, thus providing the veterinarian with a major improvement in his/her professional activities which permits allows one to perform complex tasks in anesthesia and veterinary surgery. Knowledge ofanatomical reference points increases clarity and precision in techniques involving peripheral nerve blocks.(AU)
Assuntos
Animais , Bovinos , Cães , Bovinos/anatomia & histologia , Cães/anatomia & histologia , Nervos Periféricos/diagnóstico por imagem , Anestesia Local/veterináriaRESUMO
The larval parasitoid Cotesia flavipes (Cameron) (Hymenoptera: Braconidae) is an important biological control agent of the sugarcane borer, Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae). This exotic parasitoid has been mass reared for field release since its introduction in the 1970s. Insects are exchanged between labs or introduced from the field, but without basic studies or criteria. Thus, the objective of this study was to evaluate the genetic variability of insects from six Brazilian States (São Paulo, Minas Gerais, Paraná, Goiás, Maranhão, and Alagoas) using microsatellites. Analysis of five loci using at least 22 females from each location was performed. The molecular analysis made possible to verify that four out of the five loci analyzed were polymorphic. The allele frequencies of three loci were in agreement with the Hardy-Weinberg Equilibrium for all insects of all regions. It was also observed that five alleles were exclusively presented in only two loci. The variation among and within populations was 24.65 and 75.34%, respectively. The estimated shared genotypes between the C. flavipes individuals showed that K = 2 was the most likely number of genetic groups causing the current variation, as well as high shared genotypes from these groups of the individuals. Considering all the analyzed loci, the genetic differentiation was at a moderate level. We suggest a possible mixture of biological materials based on genetic distances and the degree of structuring displayed.
Assuntos
Variação Genética , Genética Populacional , Repetições de Microssatélites , Vespas/genética , Animais , Brasil , Feminino , Frequência do Gene , Loci Gênicos , Genótipo , Mariposas , Controle Biológico de Vetores , SaccharumRESUMO
O estudo dos dados anatômicos é fundamental para possibilitar ao médico veterinário o reconhecimento de pequenas estruturas, como os nervos nos animais, oferecendo subsídio para construção do conhecimento do profissional principalmente em técnicas anestésicas e cirúrgicas. Para investigar e mapear os nervos do plexo braquial (nervo radial, nervo musculocutâneo, nervo ulnar, nervo mediano), nervo isquiático, nervo tibial, nervo femoral e os nervos para bloqueio paravertebral, foram utilizados um cadáver canino adulto, de peso aproximado de 8kg, e um cadáver de bezerro Holandês, de peso aproximado de 40kg. O mapeamento dos nervos é de grande importância, já que conhecer bem essas estruturas permite ao veterinário um bom desenvolvimento de suas atividades profissionais a fim de exercer funções mais complexas durante a anestesia e cirurgia veterinária, uma vez que, identificados os pontos de referência anatômicos, é possível trabalhar com mais clareza nas técnicas de bloqueios dos nervos periféricos.(AU)
Knowledge of animal anatomy is essential for the veterinarian to identify small structures such as nerves, thus providing a solid background for the professional especially for surgical and anesthetic techniques. To investigate and map the nerves of the brachial plexus (radial, musculocutaneous, ulnar, median), sciatic, tibial, femoral and the nerves for paravertebral blocking in bovine, embalmed specimens were used. One adult male dog weighing approximately 8kg and one 40kg male calf were used. Nerve mapping is fundamental due to its interdisciplinary nature, thus providing the veterinarian with a major improvement in his/her professional activities which permits allows one to perform complex tasks in anesthesia and veterinary surgery. Knowledge ofanatomical reference points increases clarity and precision in techniques involving peripheral nerve blocks.(AU)
Assuntos
Animais , Bovinos , Cães , Bovinos/anatomia & histologia , Cães/anatomia & histologia , Nervos Periféricos/diagnóstico por imagem , Anestesia Local/veterináriaRESUMO
Temporomandibular joint (TMJ) disorders are divided by the American Academy of Orofacial Pain into five categories. The most common ones are joint pain, as arthralgia and joint disorders, as disc displacements. An important clinical presentation of arthralgia is the painful tenderness to manual palpation or decreased pressure pain threshold (PPT). The authors conducted a study to determine the appropriate PPT value to discriminate asymptomatic TMJ individuals from those with moderate to severe arthralgia. Forty-nine individuals was evaluated and divided into groups: TMJ arthralgia, asymptomatic disc displacement and control group. Magnetic resonance images were obtained for all the groups, and algometry was performed on the TMJ lateral pole. Patients with arthralgia filled out a visual analogue scale (VAS). anova test with 1% of significance analysed the data. Specificity, sensitivity and ROC curve were also determined. Arthralgia group had significant lower PPT (mean of 1.07 kgf cm(-2) ) than the others. Asymptomatic disc displacement group (mean of 1.64 kgf cm(-2) ) has shown significant lower PPT than the control (mean of 2.35 kgf cm(-2) ). 89.66% of specificity and 70% of sensitivity were obtained when 1.36 kgf cm(-2) was applied to the TMJ (ROC area = 0.90). This value was considered to be the most appropriate to detected moderate to severe TMJ arthralgia. Indeed, the presence of disc displacement seems to significantly decrease PPT levels in asymptomatic subjects. The PPT value of 1.36 kgf cm(-2) can be used in the calibration procedures of the professionals involved with temporomandibular disorders and orofacial pain.
Assuntos
Artralgia/diagnóstico , Dor Facial/diagnóstico , Limiar da Dor , Transtornos da Articulação Temporomandibular/diagnóstico , Adolescente , Adulto , Análise de Variância , Artralgia/complicações , Artralgia/fisiopatologia , Brasil , Calibragem , Dor Facial/etiologia , Dor Facial/fisiopatologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Palpação , Valor Preditivo dos Testes , Pressão , Curva ROC , Amplitude de Movimento Articular , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Transtornos da Articulação Temporomandibular/complicações , Transtornos da Articulação Temporomandibular/fisiopatologiaRESUMO
This is the first study to examine the genetic diversity of mandacaru cactus (Cereus jamacaru P. DC.). Plants of spineless mandacaru are commonly found in gardens and parks of urban areas in northeastern Brazil. In addition to exploring their ornamental potential, morphological, and genetic characterization may contribute to the development of plant materials that can be used as a source of macromolecules of potential economic interest. The goal of this study was to estimate the genetic variability of spineless mandacaru accessions using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) molecular markers, and to characterize their morphology. Ten samples of newly emitted shoots with differentiated areolas and ribs were collected from each accession from the Cactaceous Germplasm Collection of Embrapa Agroindústria Tropical, in Fortaleza, CE. Shoot shape and aspects of spine primordia (presence, location, grouping, and size of spines) were evaluated. The morphological analysis showed that the spineless mandacaru presented spine primordia. Twenty-six RAPD and 15 ISSR primers were polymorphic. A total of 262 markers were obtained, 129 of which were polymorphic. The average polymorphism of ISSR markers was higher than that of RAPD markers. The dendrograms for both analyses showed differentiation between accessions. Nevertheless, the molecular markers detected higher levels of diversity and a different pattern of diversity than those found using morphological markers. The molecular results revealed significant genetic variability both within and between groups.
Assuntos
Cactaceae/genética , Repetições de Microssatélites , Polimorfismo Genético , Cactaceae/anatomia & histologia , Genes de Plantas , Marcadores Genéticos , Filogenia , Análise de Sequência de DNAAssuntos
Doenças do Colo/microbiologia , Úlcera Duodenal/microbiologia , Histoplasmose/complicações , Úlcera Gástrica/microbiologia , Úlcera/microbiologia , Idoso , Antifúngicos/uso terapêutico , Feminino , Histoplasmose/tratamento farmacológico , Humanos , Terapia de Imunossupressão/efeitos adversos , Itraconazol/uso terapêutico , Transplante de Fígado/efeitos adversosRESUMO
OBJECTIVES: Cis-platinum based chemotherapy agents are widely used in treatment of testicular cancer and its deleterious effects on spermatogenesis are well known. Therefore an extensive survey was undertaken to evaluate the effects of antioxidants in combination with Cis-platinum in an attempt to minimize its effects upon spermatogenic function of adult rats. METHODS: A short-term prospective study (thirteen days) including twenty-four adult male Wistar rats was performed. Animals were assigned into one of three groups (eight per group): GI-control, GII-Cis-platinum treated and GIII-Cis-platinum plus superoxide dismutase and catalase. Histological analyses included germ cell counts, germ to Sertoli cell ratios and estimation of volume density components as well as the determination of the sperm reserves. Data was examined through one-way analysis of variance at 5% level of significance. RESULTS: Germ cell numbers, germ cell to Sertoli cell ratios, organ weights (except body weight) and sperm reserves presented no differences among groups. However, the volumetric proportion of some components (tubular epithelium, tunica propria, Leydig cell nuclei and stroma) were affected (p<0.05) by treatment. The most prominent testicular component, the seminiferous epithelium was reduced (p<0.05) in Cis-platinum treated animals (GII). CONCLUSION: The use of antioxidant in association with Cis-platinum did not affect sperm production (germ cell numbers, germ to Sertoli cell ratios and sperm reserves) of adult rats. However, the deleterious effect of Cis-platinum on the seminiferous tubule epithelium was minimized by antioxidants.
Assuntos
Antineoplásicos/efeitos adversos , Antioxidantes/uso terapêutico , Cisplatino/efeitos adversos , Testículo/efeitos dos fármacos , Testículo/patologia , Animais , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos WistarRESUMO
Quantification of mucosal eosinophils and mast cells in the oviducts from 22 crossbred heifers was performed in both natural (estrus, metaestrus and diestrus) and superovulated (estrus and metaestrus) estrous cycles. The number of cells/square millimeter of mucosa was obtained through counts at different regions of the oviduct (infundibulum, ampulla, ampullary/isthmic transition and isthmus). Differences were not found (P > 0.05) among numbers of cells at the different phases of the natural estrous cycle nor between natural or superovulated cycles. When all animals were separated into two phases of the estrous cycle (estrus and metaestrus), the number of eosinophils at the ampullary/isthmic transition and isthmus was higher (P < 0.01) at the estrus cycle phase, and the number at the infundibulum was higher (P < 0.001) during the metaestrus phase than at estrus. The number of mast cells was highest at the isthmus regardless of the estrus phase, and highest at the infundibulum (P < 0.001) and ampulla (P < 0.05) during the metaestrus phase. Significant correlations were found between the number of mast cells and plasma progesterone levels at the infundibulum (P < 0.001; r = 0.69) and ampulla (P < 0.03; r = 0.51). No correlation was seen between numbers of eosinophils and mast cells, progesterone and 17β-estradiol concentrations. Therefore, the distribution of mucosal eosinophils in the oviduct of heifers is apparently not related to the circulating levels of 17β-estradiol and progesterone; however, the highest number of mast cells found at the metaestrus phase of the cycle, at least for the infundibulum and ampulla, appears to be related to the high circulating progesterone plasma levels in metaestrus phase compared to estrus phase. No differences were found between animals subjected or not to superovulation.
Assuntos
Animais , Bovinos , Eosinófilos , Estradiol/química , Estro/fisiologia , Mucosa/anatomia & histologia , Bovinos/classificaçãoRESUMO
Quantification of mucosal eosinophils and mast cells in the oviducts from 22 crossbred heifers was performed in both natural (estrus, metaestrus and diestrus) and superovulated (estrus and metaestrus) estrous cycles. The number of cells/square millimeter of mucosa was obtained through counts at different regions of the oviduct (infundibulum, ampulla, ampullary/isthmic transition and isthmus). Differences were not found (P > 0.05) among numbers of cells at the different phases of the natural estrous cycle nor between natural or superovulated cycles. When all animals were separated into two phases of the estrous cycle (estrus and metaestrus), the number of eosinophils at the ampullary/isthmic transition and isthmus was higher (P < 0.01) at the estrus cycle phase, and the number at the infundibulum was higher (P < 0.001) during the metaestrus phase than at estrus. The number of mast cells was highest at the isthmus regardless of the estrus phase, and highest at the infundibulum (P < 0.001) and ampulla (P < 0.05) during the metaestrus phase. Significant correlations were found between the number of mast cells and plasma progesterone levels at the infundibulum (P < 0.001; r = 0.69) and ampulla (P < 0.03; r = 0.51). No correlation was seen between numbers of eosinophils and mast cells, progesterone and 17β-estradiol concentrations. Therefore, the distribution of mucosal eosinophils in the oviduct of heifers is apparently not related to the circulating levels of 17β-estradiol and progesterone; however, the highest number of mast cells found at the metaestrus phase of the cycle, at least for the infundibulum and ampulla, appears to be related to the high circulating progesterone plasma levels in metaestrus phase compared to estrus phase. No differences were found between animals subjected or not to superovulation.(AU)
Assuntos
Animais , Bovinos , Mucosa/anatomia & histologia , Estradiol/química , Estro/fisiologia , Eosinófilos , Bovinos/classificaçãoRESUMO
Phenotypic characteristics, antimicrobial susceptibility, and genetic relationships were analyzed in 107 Staphylococcus aureus isolates recovered from cows with subclinical mastitis in Southeastern Brazil. Thirteen different biochemical patterns were detected among isolates. A predominant pattern represented by about 54% of the isolates was distributed among several herds. Isolates of distinct phenotypic profiles were also detected within a herd. Susceptibility to ampicillin, cefotaxime, cephalotin, chloramphenicol, erythromycin, gentamycin, kanamycin, nitrofurantoin, norfloxacin, ofloxacin, oxacillin, penicillin, rifampin, sulfamethoxazole-trimethoprim, tetracycline, trimethoprim, and vancomycin, determined by the disk diffusion method, was observed in 44.9% of isolates. On the other hand, 55.1, 7.4, and 2.8% of the strains were resistant to ampicillin/penicillin, tetracycline, and erythromycin, respectively. Genetic diversity was analyzed by pulsed-field gel electrophoresis using SmaI as the restriction enzyme. All isolates could be typed by pulsed-field gel electrophoresis, which identified 16 types and 24 subtypes. Type A and its subtypes comprised 54.2% of all isolates and were recovered from 6 of the 9 herds analyzed. Other types and subtypes were also found in multiple herds. Although multiple types and subtypes were found within a specific herd, a predominant type was frequently observed.
Assuntos
Farmacorresistência Bacteriana , Mastite Bovina/microbiologia , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/metabolismo , Animais , Brasil , Bovinos , Eletroforese em Gel de Campo Pulsado , Feminino , Fermentação , Variação Genética , Genótipo , Mastite Bovina/tratamento farmacológico , Testes de Sensibilidade Microbiana , Leite/microbiologia , Fenótipo , Staphylococcus aureus/genéticaRESUMO
Tubas uterinas de 21 novilhas mestiças Bos taurus taurus x Bos taurus indicus, em diferentes fases do ciclo estral natural (estro, metaestro e diestro) ou induzido pelo tratamento superovulatório (estro e metaestro superovulados), foram avaliadas quanto à presença de cistos intra-epiteliais e à caracterização histoquímica de seu conteúdo. Verificou-se a ocorrência de cistos intra-epiteliais nas tubas uterinas em todos os animais, mais freqüentes nas regiões do infundíbulo e ampola. Eles ocorreram nos lados direito e esquerdo, ipsi- e contralateral ao ovário ativo (folículo pré-ovulatório ou corpo lúteo), nas fases estrogênica e progesterônica do ciclo. No conteúdo cístico, houve predominância de mucinas neutras e ácidas carboxiladas, sendo as mucinas sulfatadas presentes em menor intensidade, e não se observou glicogênio. Os resultados sustentam a hipótese de que esses cistos formam-se pela fusão de luminações intracitoplasmáticas e/ou vacúolos ciliados do epitélio tubário. (AU)
Uterine tubes from 21 crossbred heifers (Bos taurus taurus × Bos taurus indicus) at different phases of the natural estrus cycle (estrus, metaestrus and diestrus) or submitted to superovulation (superovulated estrus and metaestrus) were evaluated for the presence of intraepithelial cysts and for histochemical labelling of its contents. All studied animals had intraepithelial cysts mainly in the infundibular and ampullary regions. Such cysts were present regardless of the side of the uterine tube, ipsi- or contralateral to the active ovary (preovulatory follicle or corpus luteum) or of the cycle phase (estrogenic or progesteronic). Histochemical analysis revealed that neutral and acid mucins were the major substances found within the cysts. Sulphated mucins were present in low amounts and glycogen was absent. These results suggest that these cysts are probably formed by the fusion of intracytoplasmic lumina and/or ciliated vacuoles of the uterine tube epithelium.(AU)
Assuntos
Animais , Feminino , Tubas Uterinas/fisiopatologia , Cistos/fisiopatologia , Bovinos , Cistos/epidemiologia , Tubas Uterinas/anatomia & histologiaRESUMO
Tubas uterinas de 21 novilhas mestiças Bos taurus taurus Bos taurus indicus, em diferentes fases do ciclo estral natural (estro, metaestro e diestro) ou induzido pelo tratamento superovulatório (estro e metaestro superovulados), foram avaliadas quanto à presença de cistos intra-epiteliais e à caracterização histoquímica de seu conteúdo. Verificou-se a ocorrência de cistos intra-epiteliais nas tubas uterinas em todos os animais, mais freqüentes nas regiões do infundíbulo e ampola. Eles ocorreram nos lados direito e esquerdo, ipsi- e contralateral ao ovário ativo (folículo pré-ovulatório ou corpo lúteo), nas fases estrogênica e progesterônica do ciclo. No conteúdo cístico, houve predominância de mucinas neutras e ácidas carboxiladas, sendo as mucinas sulfatadas presentes em menor intensidade, e não se observou glicogênio. Os resultados sustentam a hipótese de que esses cistos formam-se pela fusão de luminações intracitoplasmáticas e/ou vacúolos ciliados do epitélio tubário.
Assuntos
Animais , Feminino , Bovinos , Cistos/epidemiologia , Cistos/fisiopatologia , Tubas UterinasRESUMO
A total of 357 clinical Streptococcus pyogenes isolates collected between 1994 and 1999 in Rio de Janeiro city were tested for susceptibility to 10 antimicrobial drugs by agar-diffusion tests. All isolates were susceptible to penicillin, cephems, and vancomycin. High resistance rates were observed for tetracycline (43.1%) and trimethoprim/sulfamethoxazole (77.9%). Three isolates (0.8%) were resistant to erythromycin, and three exhibited intermediate susceptibility. Determination of the erythromycin MICs by the agar dilution method, showed 1.6% of erythromycin resistant isolates (the three erythromycin-resistant and the three erythromycin-intermediate isolates found by agar-diffusion test). Of the erythromycin-resistant isolates subjected to the double-disc diffusion test for erythromycin and clindamycin, three isolates expressed the iMLSB and three the M phenotype. The resistance phenotypes were confirmed by comparing the clindamycin MICs determined under normal testing conditions and those determined after induction by pre-growth in 0.06 microg/ml of erythromycin. Three ermTR and three mefA-containing isolates were detected by PCR. In strains belonging to the iMLSB phenotype, two clones were identified by PFGE following restriction with SmaI. M phenotype isolates could not be restricted with SmaI. Our results indicate a low rate of erythromycin resistance among S. pyogenes isolated in Rio de Janeiro, Brazil, and pointed to the presence of both resistance mechanisms found in streptococci.