RESUMO
This study aimed to investigate the antiproteinuric and hyperkalemic mechanisms activated by dual renin-angiotensin system (RAS) blockade in renovascular hypertensive rats (2-kidney 1-clip model [2K-1C]). Six weeks after clipping the left renal artery or sham operation (2K), rats were treated with losartan, enalapril, or both drugs for two weeks. We found that 2K-1C rats displayed higher tail-cuff blood pressure (BP), increased non-clipped kidney Ang II concentration, and more pronounced urinary albumin excretion than 2K. BP was decreased by the treatment with either enalapril or losartan, and the combination of both drugs promoted an additional antihypertensive effect in 2K-1C rats. Renal Ang II content and albuminuria were reduced by either enalapril or losartan in monotherapy and restored to control levels by dual RAS blockade. Albuminuria in 2K-1C rats was accompanied by downregulation of the glomerular slit protein podocin, reduction of the endocytic receptors megalin and cubilin, and a marked decrease in the expression of the ClC-5 chloride channel, compared to 2K animals. Treatment with losartan and enalapril in monotherapy or combination increased the expression of podocin, cubilin, and ClC-5. However, only the combined therapy normalized podocin, cubilin, and ClC-5 protein abundance in the non-clipped kidney of 2K-1C rats. Renovascular hypertensive 2K-1C rats had a lower concentration of plasma potassium compared to 2K rats. Single RAS blockade normalized potassium plasma concentration, whereas 2K-1C rats treated with dual RAS blockade exhibited hyperkalemia. Hypokalemia in 2K-1C rats was accompanied by an increase in the cleaved activated forms of α-ENaC and γ-ENaC and the expression of ß-ENaC. Combined RAS blockade but not monotherapy significantly reduced the expression of these ENaC subunits in 2K-1C rats. Indeed, double RAS blockade reduced the abundance of cleaved-α-ENaC to levels lower than those of 2K rats. Collectively, these results demonstrate that the antiproteinuric effect of dual RAS blockade in 2K-1C rats is associated with the restored abundance of podocin and cubilin, and ClC-5. Moreover, double RAS blockade-induced hyperkalemia may be due, at least partially, to an exaggerated downregulation of cleaved α-ENaC in the non-clipped kidney of renovascular hypertensive rats.
RESUMO
Members of the trochoidean genus Margarella (Calliostomatidae) are broadly distributed across Antarctic and sub-Antarctic ecosystems. Here we used novel mitochondrial and nuclear gene sequences to clarify species boundaries and phylogenetic relationships among seven nominal species distributed on either side of the Antarctic Polar Front (APF). Molecular reconstructions and species-delimitation analyses recognized only four species: M. antarctica (the Antarctic Peninsula), M. achilles (endemic to South Georgia), M. steineni (South Georgia and Crozet Island) and the morphologically variable M. violacea (=M. expansa, M. porcellana and M. pruinosa), with populations in southern South America, the Falkland/Malvinas, Crozet and Kerguelen Islands. Margarella violacea and M. achilles are sister species, closely related to M. steineni, with M. antarctica sister to all these. This taxonomy reflects contrasting biogeographic patterns on either side of the APF in the Southern Ocean. Populations of Margarella north of the APF (M. violacea) showed significant genetic variation but with many shared haplotypes between geographically distant populations. By contrast, populations south of the APF (M. antarctica, M. steineni and M. achilles) exhibited fewer haplotypes and comprised three distinct species, each occurring across a separate geographical range. We hypothesize that the biogeographical differences may be the consequence of the presence north of the APF of buoyant kelps - potential long-distance dispersal vectors for these vetigastropods with benthic-protected development - and their near-absence to the south. Finally, we suggest that the low levels of genetic diversity within higher-latitude Margarella reflect the impact of Quaternary glacial cycles that exterminated local populations during their maxima.
Assuntos
Gastrópodes/classificação , Gastrópodes/genética , Filogeografia , Animais , Regiões Antárticas , Teorema de Bayes , DNA/genética , DNA Mitocondrial/genética , Filogenia , Polimorfismo Genético , América do Sul , Especificidade da Espécie , Fatores de TempoRESUMO
Reactive dyes are one of the major pollutants in textile wastewater and a concern because they are not easily degraded by conventional wastewater treatments. Heterogeneous photocatalysis has been considered an effective option for treating wastewater containing those dyes. This research work assesses the photocatalytic degradation of reactive dyes using UV irradiation and pure or impregnated ZnO. In addition to photocatalysis, separate photolysis and adsorption experiments were conducted but showed low efficiency. The dye degradation was monitored by UV-Vis spectroscopy and mineralization was determined by total organic carbon (TOC) analyses. Total color removal was achieved after 30 min of irradiation using pure ZnO. The Black 5 dye photocatalytic decolorization reaction followed first-order kinetics, while Yellow 145, Red 4 and Blue 21 dyes followed zero-order kinetics. TOC removals in the range of 70-80% were achieved after 240 min of individual photocatalytic treatment with ZnO. The performance of each photocatalyst was also compared when the four dyes were mixed together and the order of efficiency in the mineralization process was as follows: Fe/ZnO > ZnO > Co/ZnO. This result was explained by the crystal field theory.
Assuntos
Corantes/química , Raios Ultravioleta , Poluentes Químicos da Água/química , Purificação da Água/métodos , Óxido de Zinco/química , Catálise , Estrutura Molecular , Processos FotoquímicosRESUMO
Current challenges in adhesive dentistry include over-hydrophilic bonding formulations, which facilitate water percolation through the hybrid layer and result in unreliable bonded interfaces. This study introduces nanogel-modified adhesives as a way to control the material's hydrophobic character without changing the basic monomer formulation (keeping water-chasing capacity and operatory techniques unaltered). Nanogel additives of varied hydrophobicity were synthesized in solution, rendering 10- to 100-nm-sized particles. A model BisGMA/HEMA solvated adhesive was prepared (control), to which reactive nanogels were added. The increase in adhesive viscosity did not impair solvent removal by air-thinning. The degree of conversion in the adhesive was similar between control and nanogel-modified materials, while the bulk dry and, particularly, the wet mechanical properties were significantly improved through nanogel-based network reinforcement and reduced water solubility. As preliminary validation of this approach, short-term micro-tensile bond strengths to acid-etched and primed dentin were significantly enhanced by nanogel inclusion in the adhesive resins.
Assuntos
Nanopartículas/química , Cimentos de Resina/química , Condicionamento Ácido do Dente/métodos , Bis-Fenol A-Glicidil Metacrilato/química , Canfanos/química , Química Farmacêutica , Resinas Compostas/química , Colagem Dentária , Dentina/ultraestrutura , Adesivos Dentinários/química , Módulo de Elasticidade , Humanos , Interações Hidrofóbicas e Hidrofílicas , Teste de Materiais , Metacrilatos/química , Maleabilidade , Polimerização , Poliuretanos/química , Solubilidade , Estresse Mecânico , Temperatura , Resistência à Tração , Fatores de Tempo , Temperatura de Transição , Viscosidade , Água/químicaRESUMO
OBJECTIVES: Oxidative stress and inflammation induce the expression of heme oxygenase-1, which produces carbon monoxide (CO), and nitric oxide synthase, which produces nitric oxide (NO). Exhaled CO and NO levels are elevated in asthmatic patients and are decreased after corticosteroid treatment, suggesting that they may be useful as noninvasive markers of airway inflammation. STUDY DESIGN: We measured forced expiratory volume in the first second, PC(20), and exhaled CO and NO levels in 29 children (18 boys, mean age 11.5 +/- 0.53 years) with asthma of different severity and 40 nonsmoking children without asthma (21 boys, mean age 8.1 +/- 0.35 years). We also studied whether upper respiratory tract infections were associated with elevated exhaled CO. RESULTS: Exhaled CO levels (ppm) were significantly higher (2.17 +/- 0.21) in children with persistent asthma compared with those in children with infrequent episodic asthma (1.39 +/- 0.18, P <.05) and healthy children (1.01 +/- 0.12, P <.001). The CO levels in children with infrequent episodic asthma and the normal control group, however, were not different. In contrast, exhaled NO levels (ppb) were higher in children with persistent asthma (24.2 +/- 5.9, P <.001) and infrequent episodic asthma (14.5 +/- 3.73, P <.05) than in normal subjects (5.1 +/- 0.24), but no significant difference was seen between the 2 asthmatic groups. In healthy children with upper respiratory tract infections (n = 12), exhaled CO concentrations were significantly elevated (2.16 +/- 0.33) during the acute symptomatic phase. No correlation was found between exhaled CO and forced expiratory volume in the first second or PC(20). CONCLUSIONS: Noninvasive measurement of exhaled CO may provide complementary data for assessment of asthma control in children. However, elevated CO levels are nonspecific and may be found in association with an acute viral illness.
Assuntos
Asma/diagnóstico , Monóxido de Carbono/análise , Asma/metabolismo , Testes Respiratórios , Testes de Provocação Brônquica , Criança , Estudos Transversais , Feminino , Volume Expiratório Forçado , Heme Oxigenase (Desciclizante)/metabolismo , Humanos , Masculino , Óxido Nítrico/análise , Estresse Oxidativo , Infecções Respiratórias/metabolismoRESUMO
A 3rd species of the flea genus Polygenis Jordan was added to the U.S. fauna by extension of known range from Mexico into New Mexico. Eleven males and 24 females of P. martinezbaezi Vargas were reared from a rodent nest, probably that of a yellow-nosed cotton rat, Sigmodon ochrognathus Bailey.
Assuntos
Ectoparasitoses/veterinária , Sigmodontinae/parasitologia , Sifonápteros , Animais , Ectoparasitoses/parasitologia , Feminino , Masculino , New Mexico , RatosRESUMO
Os autores relatam o caso de um paciente de 30 anos, branco, sexo masculino, que desenvolveu abdome agudo obstrutivo, cujo diagnostico, apos laparotomia, revelou a presença de uma intussuscepçao ileocecal, a qual, desfeita manualmente, evidenciou massa tumoral esferica de 5 cm de diametro em ileo terminal, tendo a biopsia de congelaçao revelado neoplasia maligna pouco diferenciada. Foi realizada hemicolectomia a direita e ressecçao de segmento de ileo terminal com ileo transverso-anastomose termino-lateral em dois planos, com evoluçao pos-operatoria sem intercorrencias. O exame histologico anatomopatologico, bem como posterior estudo imunohistoquimico, mostraram tratar-se de linfoma tipo "T" primario de ileo. A investigaçao posterior ao ato cirurgico, mostrou ausencia de acometimento neoplasico em linfonodos, medula ossea e outros sitios. O paciente foi encaminhado para tratamento complementar quimioterapico, com boa evoluçao. Os autores enfatizam a baixa frequencia dessa patologia como primaria de ileo terminal 1,2,3, bem como a surpreendente evoluçao do paciente, que ate o presente momento nao apresentou outra manifestaçao da doença em outros locais, embora tenha completado um ano de evoluçao
Assuntos
Humanos , Masculino , Adulto , Abdome Agudo , Doenças do Íleo , Obstrução Intestinal , Intussuscepção , Linfoma de Células TRESUMO
A prospective study of children undergoing open heart surgery with cardiopulmonary bypass showed that many of them produced autoantibodies. No association was found between these antibodies, including anticardiolipin antibodies, and the occurrence of postpericardiotomy syndrome.
Assuntos
Autoanticorpos/biossíntese , Ponte Cardiopulmonar , Síndrome Pós-Pericardiotomia/imunologia , Adolescente , Anticorpos Anticardiolipina/análise , Criança , Pré-Escolar , Humanos , Lactente , Músculo Liso/imunologia , Estudos Prospectivos , Reticulina/imunologiaRESUMO
Seven species of mites were recovered from 133 Brazilian free-tailed bats, Tadarida brasiliensis, and 94 big brown bats, Eptesicus fuscus, from February through November 1990 in colonies that shared roosting space in east-central Alabama. The macronyssid Chiroptonyssus robustipes (Ewing) was the most common mite on T. brasiliensis (964 mites, 87% of bats infested) and on E. fuscus (109 mites, 29% of bats infested). However, C. rubustipes normally is a specific parasite of T. brasiliensis. The macronyssids Steatonyssus ceratognathus (Ewing) and S. occidentalis (Ewing) were recovered from both species of bats in low numbers. S. ceratognathus is not a typical parasite of either species of bat, but S. occidentalis normally is specific to E. fuscus. Predictably, S. occidentalis was most frequently collected from E. fuscus (16 mites, 9% of bats infested), but two specimens were recovered from T. brasiliensis. Five specimens of the laelapid Androlaelaps casalis (Berlese) (a mite that is frequently associated with rodents) and one specimen of the myobiid mite Ewingana (Doreyana) longa (Ewing) (a specific ectoparasite of T. brasiliensis) were also recovered from T. brasiliensis. Singletons of the rosensteiniids Mydopholeus sp. and Nycteriglyphites pennsylvanicus Fain, Lukoschus & Whitaker were the only additional mites collected from E. fuscus; both of these mites have previously been collected from bats or their guano but are recorded here from Alabama for the first time. With respect to ectoparasite cross-infestations, E. fuscus appears to be at greater risk from sharing roots with T. brasiliensis. This is highlighted by the comparatively large numbers of C. robustipes that occurred on E. fuscus and the low numbers of S. occidentalis on T. brasiliensis. Although mites were the only arthropods recovered from bats in this study, a separate survey in 1991 revealed that the bat bug Cimex adjunctus Barber infested some other colonies of T. brasiliensis and E. fuscus in Alabama.
Assuntos
Quirópteros/parasitologia , Infestações por Ácaros/veterinária , Alabama , Animais , Feminino , Masculino , Infestações por Ácaros/parasitologia , ÁcarosAssuntos
Traumatismos Craniocerebrais/imunologia , Infecções/etiologia , Ferimentos não Penetrantes/imunologia , Adolescente , Formação de Anticorpos , Bacteriófago phi X 174/imunologia , Criança , Pré-Escolar , Traumatismos Craniocerebrais/complicações , Toxoide Diftérico/imunologia , Humanos , Lactente , Toxoide Tetânico/imunologia , Ferimentos não Penetrantes/complicaçõesRESUMO
Anesthetized golden lion tamarins (Leontopithecus rosalia rosalia), a highly endangered species, were examined for ectoparasites by brushing the fur and swabbing the ears. Ectoparasites recovered from the fur included four species of immature ticks (Amblyomma spp.), three species of chiggers (Euschoengastia sp., Microtrombicula brennani and Speleocola tamarina), and one species of follicular mite (Rhyncoptes anastosi). Ectoparasites do not seem to be of particular significance to the health of the golden lion tamarin; this may in part result from grooming.
Assuntos
Ácaros e Carrapatos/isolamento & purificação , Callitrichinae/parasitologia , Animais , BrasilRESUMO
Um caso de fistula carotidocavernosa tratado por oclusao endovascular, utilizando-se sonda de Fogarty, e relarado. A simplicidade, eficiencia e detalhes tecnica sao discutidos.
Assuntos
Fístula , Neurocirurgia , Doenças das Artérias Carótidas , Fístula , Neurocirurgia , Doenças das Artérias CarótidasRESUMO
A sindrome da sela vazia tem despertado grande interesse nao so dos neurocirurgioes e neurologistas como tambem dos endocrinologistas. Os autores fazem a analise do seu material, constituido de dez casos, num periodo de tres anos, investigados nos servicos de Neurocirurgia da Universidade Federal do Rio de Janeiro, chamando atencao para os seus principais aspectos, a luz dos conhecimentos atuais.