Influence of Flat Occlusal Splint on Stresses Induced on Implants for Different Fixed Prosthetic Systems.

OBJECTIVE: The flat occlusal plate has been recommended to reduce stress concentration in implant prosthesis treatments. The purpose was to investigate the influence of the occlusal splint on three-element implant-supported fixed prosthesis. MATERIALS AND METHODS: A three-dimensional virtual model was created consisting of a cortical and spongy bone block simulating the region from first premolar to the maxillary first molar using two HE or MT implants (4 x 11mm) with Ti and/or Y-TZP abutments. The second premolar was the pontic of the prosthesis. The three-element fixed prosthesis with a zirconia infrastructure and Y-TZP coating were cemented, in addition to using a flat occlusal splint made of acrylic resin in the region. Combined axial and oblique loads of 100N and 300N were applied. RESULTS: The tensile stresses on MT implant bone tissue produced values of 4-19% lower than those of HE implants. The lowest differences were observed for oblique loading with an occlusal splint, with a 4% (Ti-Y-TZP) and 9% (Ti-Ti) decrease. When the compressive stresses were evaluated, HE implants produced lower values than MT implants. CONCLUSION: A significant increase was observed in the oblique loading stresses in the absence of occlusal splints, regardless of the applied load.

Situação epidemiológica da brucelose bovina no Distrito Federal / Epidemiological status of bovine brucellosis in the Federal District, Brazil

Realizou-se um estudo para caracterizar a situação epidemiológica da brucelose bovina no Distrito Federal (DF). No total foram amostrados 2.019 animais, provenientes de 278 propriedades. Em cada propriedade visitada aplicou-se um questionário epidemiológico para verificar o tipo de exploração e as práticas de criação e sanitárias que poderiam estar associadas ao risco de infecção pela doença. O protocolo utilizado foi o da triagem com o teste do antígeno acidificado tamponado e a confirmação dos positivos com o teste do 2-mercaptoetanol. O rebanho foi considerado positivo quando pelo menos um animal foi reagente às duas provas sorológicas. A prevalência no DF foi de 2,5 por cento [1,0-5,1 por cento] para propriedades e de 0,16 por cento [0,04-0,28 por cento] para animais. Em razão dos resultados encontrados, que permitem pensar em estratégias de erradicação, recomenda-se que o DF intensifique o diagnóstico de brucelose, tanto na forma de testes sorológicos sistemáticos como pela introdução de mecanismos de detecção rápida em laticínios, em ambos os casos a fim de aumentar o número de propriedades certificadas como livres da doença e melhorar a sensibilidade do sistema de vigilância ativa.

A study to characterize the epidemiological status of brucellosis was carried out in the Federal District of Brazil. A total of 2,019 serum samples from 278 herds were collected. In each herd, it was applied an epidemiological questionnaire focused on herd traits as well as husbandry and sanitary practices that could be associated with the risk of infection. The serum samples were screened for antibodies against Brucella spp. by the Rose-Bengal Test (RBT), and all positive sera were re-tested by the 2-mercaptoethanol test (2-ME). The herd was considered positive if at least one animal was positive on both RBT and 2-ME tests. Herd prevalence was estimated as 2.5 percent [1.0-5.1 percent] whereas animal prevalence was 0.16 percent [0.04-0.28 percent]. Given these results, that may warrant the implementation of eradication strategies, there is a case for intensifying the serological testing in the Federal District, coupled with the introduction of rapid detection methods by the dairy industries, with a view to increasing the number of accredited free herds and improving the sensitivity of the surveillance system..

Estudo anatomopatológico e imuno-histoquímico de carcinoma renal metastático em um bovino / Anatomopathological and immunohistochemical studies of metastatic renal carcinoma in a cow

O presente relato descreve um caso de carcinoma renal metastático em uma vaca mestiça de seis anos de idade com histórico de emagrecimento progressivo, tosse e dificuldade de locomoçäo. Ao exame clínico, foram observados cifose, secreçäo catarral nas narinas e estertores à auscultaçäo pulmonar. A palpaçäo retal foi detectada uma grande massa de consistência firme, caudal ao rim direito. A laparotomia paralombar direita confirmou a presença dessa massa no pólo caudal do rim direito. Devido a impossibilidade da exérese, optou-se pela eutanásia. A necropsia, observou-se uma massa de 50cm de diâmetro, de aproximadamente quatro quilogramas, com superfície lisa, bem vascularizada de consistência firme, coloraçäo esbranquiçada, que rangia ao corte e apresentava-se aderida às alças do intestino grosso. Os linfonodos mediastinais e alguns linfonodos mesentéricos apresentavam-se aumentados de volume, de consistência firme e esbranquiçados e os pulmöes apresentavam nódulos de tamanhos variados e com características similares àquelas da massa renal. Histologicamente, a neoplasia apresentava características de carcinoma de padräo tubular. Pela imuno-histoquímica foi detectada positividade para os seguintes marcadores tumorais: vimentina (V-9), cytokeratin-7, CD68, 35betaH11, CEA poli e RCC ("renal cell carcinoma"), confirmando a origem renal do processo neoplásico

Regulatory studies of L-glutamate dehydrogenase from Trypanosoma cruzi epimastigotes.

1. The specific activity of NADP-dependent L-glutamate dehydrogenase (GDH) from T. cruzi epimastigotes increased from 0.7 at early log-phase to 1.4 mumol/min/mg of protein at the stationary phase. 2. When T. cruzi cells were incubated in the presence of L-glutamate (0.08%), the GDH had a specific activity of 2.2, much higher than that of cells incubated in the presence of D-glucose (0.08%), which was 1.2 mumol/min/mg of protein. 3. The specific activity of NADP-dependent GDH from cells incubated in the presence of L-glutamate did not vary when the cells were treated with cycloheximide (100 ng/ml) or chloramphenicol (0.5 mg/ml). 4. The activity of the NAD-dependent GDH did not change in any of the situations described above. 5. AMP, ADP, ATP, citrate, isocitrate, oxaloacetate, fructose-1,6-diP, pyruvate, L-proline and L-arginine did not have any effect on the NADP-linked GDH activity. Product inhibition studies were done on the latter GDH activity.

Evidence for three respiratory terminals in Trypanosoma cruzi epimastigotes.

The respiration of T. cruzi epimastigotes was studied using KCN (1 mM) and NaN3 (5 mM) as inhibitors and glucose (33 mM) as substrate. NaN3 inhibits 18% and KCN 58% of the oxygen uptake when T. cruzi cultures enter the stationary phase. The azide-inhibition pattern closely follows endogenous respiration pattern throughout the different growth phases. Titration of the oxygen uptake with cyanide and azide, with the results treated as Dixon plots, indicated the presence of: a) one respiratory terminal sensitive to both cyanide and azide; b) another cyanide-sensitive but azide-insensitive; c) a third insensitive to both inhibitors. Ethidium bromide (5 micrograms/ml) treatment caused the disappearance of the azide-sensitive terminal in the stationary phase.

Incorporation of ammonium in amino acids by Trypanosoma cruzi.

Ammonium ions were incorporated into L-glutamate and alpha-ketoglutarate in epimastigote forms of Trypanosoma cruzi through the following enzymatic systems: NADPH and NADH-dependent glutamate dehydrogenase, NADPH-dependent glutamate synthase, L-glutamine synthetase and NADH-dependent glutamate synthase in order of decreasing specific activity (mumoles of product formed/min/mg protein). The pH optima and Km's for the glutamate dehydrogenase system were determined. Disc electrophoresis showed the presence of cathodic bands of GDH activity, which were highly dependent on NADP+.