Alginate-chitosan systems: In vitro controlled release of triamcinolone and in vivo gastrointestinal transit

The aim of this study was to develop multiparticulate therapeutic systems of alginate (AL) and chitosan (CS) containing triamcinolone (TC) to colonic drug delivery. Multiparticulate systems of AL-CS, prepared by a complex coacervation/ionotropic gelation method, were characterized for morphological and size aspects, swelling degree, encapsulation content and efficiency, in vitro release profile in different environments simulating the gastrointestinal tract (GIT) and in vivo gastrointestinal transit. The systems showed suitable morphological characteristics with particle diameters of approximately 1.6 mm. In simulated gastric environment, at pH 1.2, the capsules presented low degree of swelling and in vitro release of drug. A higher swelling degree was observed in simulated enteric environment, pH 7.5, followed by erosion. Practically all the drug was released after 6 h of in vitro assay. The in vivo analysis of gastrointestinal transit, carried out in rats, showed that the systems passed practically intact through the stomach and did not show the same profile of swelling observed in the in vitro tests. It was possible to verify the presence of capsules in the colonic region of GIT. The results indicate that AL-CS multiparticulate systems can be used as an adjuvant for the preparation of therapeutic systems to colonic delivery of drugs. (C) 2010 Elsevier Ltd. All rights reserved.

Progression of nephropathy after islet of langerhans transplantation in alloxan-induced diabetic rats

We studied the effects of islet of Langerhans transplantation (IT) on the kidney lesions of rats with alloxan-induced diabetes. Forty-five inbred male Lewis rats were randomly assigned to 3 experimental groups: group Gl included 15 non-diabetic control rats (NC), group GIT included 15 alloxan-induced diabetic rats (DC), and group III included 15 alloxan-induced diabetic rats that received pancreatic islet transplantation prepared by nonenzymatic method from normal donor Lewis rats and injected into the portal vein (IT). Each group was further divided into 3 subgroups of 5 rats which were sacrificed at 1, 3, and 6 months of follow-up, respectively. Clinical and laboratorial parameters were recorded in the mentioned periods in the 3 experimental groups. For histology, the kidneys of all rats of each subgroup were studied and 50 glomeruli and 50 tubules of each kidney were analyzed using light microscopy by two different investigators in a double blind study. The results showed progressive glomerular basement membrane thickening (GBMT), mesangial enlargement (ME), and Bowman's capsule thickening (BCT) in the 3 experimental groups throughout the follow-up. These alterations were significantly more severe in DC rats at 6 months when compared to NC rats (p < 0.01). However, the degree of GBMT, ME, and BCT observed in DC rats was not statistically different from IT rats at 1, 3, and 6 months. In addition, Armanni-Ebstein lesions of the tubules (AE) and tubular lumen protein (PRO) observed in DC rats were also observed in IT rats all over the study. These lesions were never present in NC rats. We conclude that IT did not prevent progression of kidney lesions in alloxan-induced diabetic rats within 6 months after transplantation.

An in vitro growth inhibition test for measuring the potency of Leptospira spp. Sejroe group vaccine in buffaloes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tamanho relativo dos órgãos internos de zebuínos sob alimentação restrita e Ad libitum

Os efeitos do nível nutricional e da raça sobre o tamanho relativo dos órgãos internos foram estudados. Sessenta e três machos não-castrados, sendo 16 da raça Gir, 16 Guzerá, 16 Mocho de Tabapuã e 15 da raça Nelore, com idade média de 24 meses e pesos vivos médios iniciais de 376,4; 357,6; 362,0; e 368,6 kg, respectivamente, foram usados. Os animais de cada raça foram divididos, aleatoriamente, em cinco categorias. Uma categoria foi abatida imediatamente (AB); três categorias receberam ad libitum ração contendo 50% de concentrado na matéria seca (categoria 1, 2 e 3), em baias individuais; e uma categoria recebeu a mesma ração, em quantidade restrita, suprindo níveis de proteína e energia 15% acima da mantença (AR). Os animais das categorias 1, 2 e 3 foram abatidos ao atingirem pesos vivos individuais de 405, 450 e 500 kg, respectivamente. No abate, o peso de corpo vazio (PCVZ) foi determinado e os pesos dos órgãos internos e víscera foram registrados. Não houve diferenças entre raças nos pesos de fígado, baço, intestinos delgado e grosso, rúmen-retículo, omaso, estômagos e trato gastrintestinal (TGI), quando expressos em 100 kg de PCVZ. A restrição alimentar não influiu nos pesos do coração e dos pulmões, mas reduziu o peso do fígado e os componentes do TGI.

Broiler breeder trace mineral nutrition and feeding practices on embryo progeny development

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Magnetic images of pharmaceutical dosage forms in the human gastrointestinal tract

Oral administration with solid dosage forms is a common route in the drug therapy widely used. The drug release by the disintegration process occurs in several gastrointestinal tract (GIT) regions. AC Biosusceptometry (ACB) was originally proposal to characterize the disintegration process of tablets in vitro and in the human stomach, through changes in magnetic signals. The aim of this work was to employ a multisensor ACB system to monitoring magnetic tablets and capsules in the human GIT and to obtain the magnetic images of the disintegration process. The ACB showed accuracy to quantify the gastric residence time, the intestinal transit time and the magnetic images allowed to visualize the disintegration of magnetic formulations in the GIT. The ACB is a non-invasive, radiation free technique, completely safe and harmless to the volunteers and had demonstrated potential to evaluate pharmaceutical dosage forms in the human gastrointestinal tract. © 2005 IEEE.

Gastrointestinal cytomegalovirus disease in renal transplant recipients: A case series

The purpose of this article was to report a series of 23 renal transplant recipients with histologically proven and immunohistochemically confirmed cytomegalovirus (CMV) lesions in the gastrointestinal tract (GIT) and to assess the risk factors associated with severe disease/mortality. CMV patients (n=23) were allocated into two groups: those who died (n=6) and those considered cured (n=17). Overall mortality rate was 26% (6/23). Initial symptoms suggestive of lower GIT involvement were observed in all death cases and in 35.3% of those cured (p=0.01). Enterorrhagia was seen in 83.3% of the patients who died. Death risk increased twofold (RR 2 [1.13-3.52], p=0.01) when symptoms of lower GIT involvement were initially observed and sixfold when enterrohagia was present (RR 6 [1.1-35.9], p=0.001). Among death cases, mean time at diagnosis was significantly more distant (2002±2.9×2008±1.6, p=0.04). The difference in mortality rates seen as service practices changed along the years demonstrates the importance of early diagnosis. © 2011 John Wiley & Sons A/S.

Avaliação da atividade de contração e evaziamento gástrico em ratos gastretomizados por biosusceptometria AC

Pós-graduação em Biologia Geral e Aplicada - IBB

Biosusceptometria de corrente alternada para avaliação de esvaziamento gástrico e trânsito gastrintestinal

Pós-graduação em Biologia Geral e Aplicada - IBB

Análise experimental de copolímero na estabilidade primária de implantes osseointegráveis: avaliação microscópica em ratos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A biosusceptometria AC aplicada à tecnologia farmacêutica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Sistema multiparticulado magnético: desenvolvimento e avaliação In Vivo através da biossusceptometria AC

Pós-graduação em Ciências Farmacêuticas - FCFAR

Perfil tecnológico e funcional de cepas probióticas em leite fermentado

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação de parâmetros farmacêuticos em comprimidos matriciais empregando a técnica de Biosusceptometria AC

Oral administration is widely accepted route for drug delivery and solid dosage forms are commonly employed. The variation of absorption profiles along the human gastrointestinal tract (GIT) and the ability to target drugs by adequate dosage forms to distinct sites is the challenge in the pharmaceutical development of solid dosage forms. AC Biosusceptometry (ACB) is a technique that deserves consideration due to its features, accuracy of results and versatility. The purpose of this work was to evaluate, by employing the AC Biosusceptometer, the rate of swelling of systems matrices consisting of hydrophilic polymer (hydroxypropyl methyl cellulose) and magnetic material. Matrices tablets were evaluated in vitro to a more detailed analysis of kinetics of swelling, in addition to the study and application of mathematical models to correlate the magnetic area variation and the water uptake. All the procedures for qualitative and quantitative analysis of digital signals as well as the magnetic images processing were performed in MatLab® (Mathworks Inc.). ACB technique proved to be useful towards estimating the swelling properties of hydrophilic matrices in vitro, showing a promising capacity for further analyses involving dissolution test and in vivo studies, supporting their innovative potential pharmaceutical applications

Avaliação do efeito da gastrectomia na motilidade e no esvaziamento gástrico em ratos por biosusceptometria de corrente alternada

The study of gastrointestinal tract (GIT) functions is necessary due to the increasing number of pathologies associated with it. Directly influencing the quality of life, the gastrointestinal tract provides a number of parameters that, when analyzed, allow us to describe its dysfunctions. Thus, many techniques can be combined to obtain these properties related to the GIT. However, these techniques are often invasive, require surgery, catheter insertion, or to build a temporal model of these functions, require the sacrifice of animals in a series of data collection. The technique used in this study has the advantage of having a low operating cost, being free of ionizing radiation, non-invasive and is known as biosusceptometry AC (BAC), used to evaluate the properties of the GI tract by monitoring the position and concentration of materials magnetically marked. The sensor consists of two pairs of coils, one reference and one for detection. A fixed base line separates the sensing and reference coils, and also functions as support for the instrumentation. It is also important to note that the detection coils are arranged in a first order (subtraction) gradiometric way. The objective of this study was to analyze the effects of gastrectomy in gastric emptying and gastrointestinal transit time of solid food in rats using a BAC system associated with magnetic markers. To realize this study was constructed a dedicated BAC sensor, built to analyze these GIT properties. Data acquisition was obtained by aligning the magnetic sensor with the stomach and colon of the animal at pre-determined intervals. Thus, when approaching the magnetic material of the sensor, the balance created between the two sides of the sensor is broken. This imbalance can be measured, digitized and acquired. Tracer was used as a ration magnetically marked with ferrite... (Complete abstract click electronic access below)