31 resultados para Annual ring


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Cerebral tuberculomas constitute a major differential diagnosis of cerebral toxoplasmosis in human immunodeficiency virus (HIV)-infected patients in developing countries. We report the case of a 34-year old woman co-infected with HIV and possible disseminated tuberculosis (hepatitis, lymphadenopathy, and pleural effusion) who presented a large and solitary intracranial mass lesion. Despite extensive diagnostic efforts, including brain, ganglionar, and liver biopsies, no definitive diagnosis was reached. However, a trial with first-line antituberculous drugs led to a significant clinical and radiological improvement. Atypical presentations of cerebral tuberculomas should always be considered in the differential diagnosis of intracranial mass lesions in HIV-infected patients and a trial with antituberculous drugs is a valuable strategy to infer the diagnosis in a subset of patients.

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OBJECTIVE: To describe a surgical procedure utilizing a malleable bovine pericardium ring in mitral valve repair and clinical and echodopplercadiographic results. METHODS: Thirty-two (25 female and 7 male) patients, aged between 9 and 66 (M=36.4±17.2) years, were studied over a 16-month period, with 100% follow-up. In 23 (72%) of the patients, the mitral approach was the only one applied; 9 patients underwent associated operations. The technique applied consisted of measuring the perimeter of the anterior leaflet and implanting, according to this measurement, a flexible bovine pericardium prosthesis for reinforcement and conformation of the posterior mitral annulus, reducing it to the perimeter of the anterior leaflet with adjustment of the valve apparatus. RESULTS: The patient survival ratio was 93.8%, with 2 (6.2%) fatal outcomes, one from unknown causes, the other due to left ventricular failure. Only one reoperation was performed. On echodopplercardiography, 88% of the patients had functional recovery of the mitral valve (50% without and 38% with mild insufficiency and no hemodynamic repercussions). Of four (12%) of the remaining patients, 6% had moderate and 6% had seigre insufficiency. Twenty-eight percent of class II patients and 72% of class III patients passed into classes I (65%), II (32%), and III (3%), according to NYHA classification criteria. CONCLUSION: Being flexible, the bovine pericardium ring fit perfectly into the valve annulus, taking into account its geometry and contractility. Valve repair was shown to be reproducible, demonstrating significant advantages during patient evolution, which did not require anticoagulation measures.

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Mitral valvuloplasty is efficient for repairing mitral valve disease with few complications. In some cases, obstruction of the left ventricular outflow tract may occur due to systolic anterior motion of the mitral valve. We report the case of a patient with this complication and a pressure gradient between the left ventricle and the aorta of 130 mm Hg after mitral valvuloplasty with implantation of a Gregori's ring. The management was clinical with suspension of the vasoactive drugs and introduction of a beta-blocker. Two years after the surgery, the patient is asymptomatic and has a normal life.

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Background: Ruthenium (Ru) tetraamines are being increasingly used as nitric oxide (NO) carriers. In this context, pharmacological studies have become highly relevant to better understand the mechanism of action involved. Objective: To evaluate the vascular response of the tetraamines trans-[RuII(NH3)4(Py)(NO)]3+, trans-[RuII(Cl)(NO) (cyclan)](PF6)2, and trans-[RuII(NH3)4(4-acPy)(NO)]3+. Methods: Aortic rings were contracted with noradrenaline (10−6 M). After voltage stabilization, a single concentration (10−6 M) of the compounds was added to the assay medium. The responses were recorded during 120 min. Vascular integrity was assessed functionally using acetylcholine at 10−6 M and sodium nitroprusside at 10−6 M as well as by histological examination. Results: Histological analysis confirmed the presence or absence of endothelial cells in those tissues. All tetraamine complexes altered the contractile response induced by norepinephrine, resulting in increased tone followed by relaxation. In rings with endothelium, the inhibition of endothelial NO caused a reduction of the contractile effect caused by pyridine NO. No significant responses were observed in rings with endothelium after treatment with cyclan NO. In contrast, in rings without endothelium, the inhibition of guanylate cyclase significantly reduced the contractile response caused by the pyridine NO and cyclan NO complexes, and both complexes caused a relaxing effect. Conclusion: The results indicate that the vascular effect of the evaluated complexes involved a decrease in the vascular tone induced by norepinephrine (10−6 M) at the end of the incubation period in aortic rings with and without endothelium, indicating the slow release of NO from these complexes and suggesting that the ligands promoted chemical stability to the molecule. Moreover, we demonstrated that the association of Ru with NO is more stable when the ligands pyridine and cyclan are used in the formulation of the compound.

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The activity pattern of the small sand lizard, Liolaemus occipitalis Boulenger, 1885, was investigated in the coastal sand dunes at Quintão beach (Palmares do Sul, southern, Brazil), between September 1998 and August 1999. The results showed that L. occipitalis is active all along the year, but with variations in its daily and seasonal activity patterns associated to climatic changes in the habitat. Lizard activity pattern was distributed as follows: under the sand, burrowed (73%), under vegetation (14%), dislocation (7%) and basking (6%). Mean habitat temperatures (air and substrate) were significantly different. The results indicate that L. occipitalis is a thigmothermic and heliothermic species that regulates its body temperature through behavioral mechanisms, and that thermoregulation is mainly associated with substrate.

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The foraging activity of Geotrigona mombuca Smith, 1863 was studied under natural conditions aiming to verify the influence of seasonal changes on daily flight activity and annual cycle of the colony. Daily flight activity was monitored for a year based on the observation and counting of foragers leaving and entering the hive, as well as the kind of material transported and meteorological factors such as day time, temperature and relative humidity. The influence of seasonal changes was evidenced by alterations on daily rhythm of flight activity and by differences on transportation of food resources, building material and garbage. These data indicate that forager behavior is related to daily microclimate conditions and it is synchronized with the requirements of colony annual cycle, which determines an intense pollen collection in the summer. Thus, the recomposition of the intranidal population in spring and summer can be ensured, which is characterized both for a higher intensity of flight activity and increase in garbage and resin transport, as well as the swarming process in the spring. In this way, an action targeting the preservation or management of the species in a natural environment should consider that survival and reproduction of the colony depends greatly on the amount of available pollen in late winter.

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ABSTRACT Atlantirivulus riograndensis (Costa & Lanés, 2009) is a fish registered to the basin of Patos lagoon and the adjacent coastal plains in southern states of Rio Grande do Sul and Santa Catarina, Brazil, found in shallow water courses with that have large quantities of aquatic vegetation and forest edges. The objective of this study was to investigate the reproductive strategy and tactics of this species including the sex ratio, the length at first maturity, spawning type, fecundity and the possible associations among reproduction and abiotic factors. Sampling of specimens occurred in perennial wetlands within the Banhado dos Pachecos wildlife refuge, in the city of Viamão, state of Rio Grande do Sul, Brazil, which is a conservation unit that belongs to an area of environmental protection in the Pampa Biome. The capture of 30 A. riograndensis specimens per month occurred from January to December of 2012. A total of 188 females and 172 males were captured and the total sex ratio was 1:1 in the sampled population. Sexual maturity of the species occurs after 13.59 and 11.92 mm (SL) for females and males, respectively. Both a multiple spawning and a long reproductive period (since August to March) were confirmed by the presence of post-ovulatory follicles that were observed through histological analysis and the values of the gonadosomatic index in females considered spawning capable. The average absolute fecundity of the species is of 19.33 (± 6.18) vitellogenic oocytes in mature ovaries. No significant relationship was found between mean GSI and the abiotic data. Reproductive tactics presented by A. riograndensis indicate a species with an opportunistic reproductive strategy, following the pattern of other species of the Rivulidae family.

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The present investigation is related to the frequency of infection and to the gross and microscopic lesions associated to the presence of trichurid worms in 50 ring-necked pheasants (Phasianus colchicus) from backyard flocks in the state of Rio de Janeiro, Brazil. In the investigated birds, the overall infection rate was of 74%, with the presence of Eucoleus perforans with 72% of prevalence and 21.2 of mean intensity, in the esophageal and crop mucosa and rarely in the junction of the proventriculus and esophagus, E. annulatus with 2% and 3 in the crop mucosa, Capillaria phasianina, with 12% and 4.3 in the cecum and small intestine and Baruscapillaria obsignata, for the first time referred in this host, with 2% and 1 in the small intestine. Clinical signs were absent. The gross lesions observed in the crop and esophagus of 14 (38.9%) pheasants parasitized with E. perforans were thickening, small nodules, congestion, and petechial haemorrhages in the mucosa. These birds presented a mean infection of 37.5 and a range of infection of 10-82. The microscopic lesions revealed chronic esophagitis with diffuse inflammatory process in the lamina propria characterized mostly by a mononuclear cell infiltrate and also with the presence of granulocytes. In the case of the parasitism of pheasants with C. phasianina, the gross lesions were absent; microscopic lesions were characterized by chronic typhlitis with mononuclear infiltrate. Gross and microscopic lesions were absent in the pheasants parasitized with E. annulatus and B. obsignata.

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A series of ring substituted 3-phenyl-1-(1,4-di-N-oxide quinoxalin-2-yl)-2-propen-1-one derivatives were synthesized and tested for in vitro leishmanicidal activity against amastigotes of Leishmania amazonensis in axenical cultures and murine infected macrophages. Structure-activity relationships demonstrated the importance of a radical methoxy at position R3', R4' and R5'. (2E)-3-(3,4,5-trimethoxy-phenyl)-1-(3,6,7-trimethyl-1,4-dioxy-quinoxalin-2-yl)-propenone was the most active. Cytotoxicity on macrophages revealed that this product was almost six times more active than toxic.

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Field capacity (FC) is a parameter widely used in applied soil science. However, its in situ method of determination may be difficult to apply, generally because of the need of large supplies of water at the test sites. Ottoni Filho et al. (2014) proposed a standardized procedure for field determination of FC and showed that such in situ FC can be estimated by a linear pedotransfer function (PTF) based on volumetric soil water content at the matric potential of -6 kPa [θ(6)] for the same soils used in the present study. The objective of this study was to use soil moisture data below a double ring infiltrometer measured 48 h after the end of the infiltration test in order to develop PTFs for standard in situ FC. We found that such ring FC data were an average of 0.03 m³ m- 3 greater than standard FC values. The linear PTF that was developed for the ring FC data based only on θ(6) was nearly as accurate as the equivalent PTF reported by Ottoni Filho et al. (2014), which was developed for the standard FC data. The root mean squared residues of FC determined from both PTFs were about 0.02 m³ m- 3. The proposed method has the advantage of estimating the soil in situ FC using the water applied in the infiltration test.

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Tannery sludge contains high concentrations of inorganic elements, such as chromium (Cr), which may lead to environmental pollution and affect human health The behavior of Cr in organic matter fractions and in the growth of cowpea (Vigna unguiculata L.) was studied in a sandy soil after four consecutive annual applications of composted tannery sludge (CTS). Over a four-year period, CTS was applied on permanent plots (2 × 5 m) and incorporated in the soil (0-20 cm) at the rates of 0, 2.5, 5.0, 10.0, and 20.0 Mg ha-1 (dry weight basis). These treatments were replicated four times in a randomized block design. In the fourth year, cowpea was planted and grown for 50 days, at which time we analyzed the Cr concentrations in the soil, in the fulvic acid, humic acid, and humin fractions, and in the leaves, pods, and grains of cowpea. Composted tannery sludge led to an increase in Cr concentration in the soil. Among the humic substances, the highest Cr concentration was found in humin. The application rates of CTS significantly increased Cr concentration in leaves and grains.

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Many forested areas have been converted to intensive agricultural use to satisfy food, fiber, and forage production for a growing world population. There is great interest in evaluating forest conversion to cultivated land because this conversion adversely affects several soil properties. We examined soil microbial, physical, and chemical properties in an Oxisol (Latossolo Vermelho distrófico) of southern Brazil 24 years after forest conversion to a perennial crop with coffee or annual grain crops (maize and soybeans) in conventional tillage or no-tillage. One goal was to determine which soil quality parameters seemed most sensitive to change. A second goal was to test the hypothesis that no-tillage optimized preservation of soil quality indicators in annual cropping systems on converted land. Land use significantly affected microbial biomass and its activity, C and N mineralization, and aggregate stability by depth. Cultivated sites had lower microbial biomass and mineralizable C and N than a forest used as control. The forest and no-tillage sites had higher microbial biomass and mineralizable C and N than the conventional tillage site, and the metabolic quotient was 65 and 43 % lower, respectively. Multivariate analysis of soil microbial properties showed a clear separation among treatments, displaying a gradient from conventional tillage to forest. Although the soil at the coffee site was less disturbed and had a high organic C content, the microbial activity was low, probably due to greater soil acidity and Al toxicity. Under annual cropping, microbial activity in no-tillage was double that of the conventional tillage management. The greater microbial activity in forest and no-tillage sites may be attributed, at least partially, to lower soil disturbance. Reducing soil disturbance is important for soil C sequestration and microbial activity, although control of soil pH and Al toxicity are also essential to maintain the soil microbial activity high.