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

Caracterização in vitro de técnica biomagnética empregando magnetômetros 3D para avaliar tempo de trânsito esofagiano

The biomagnetic techniques use different magnetic field detectors to measure parameters of the human physiology. Those techniques present the advantage of being noninvasive and radiation free. Among them we can show up the Superconducting Quantum Interference Device (SQUID), the Current Alternate Biosusceptometry (ACB) and, more recently, the employment of anisotropic magnetoresistive sensors. Those magnetic sensors have a low cost and good sensitivity to measure different physiological parameters using magnetic markers. The biomagnetic techniques have being used successfully through study on the characteristics of the gastrointestinal tract. Recent research, the magnetoresistors were used to evaluate the transit time and localization of magnetic sources in different parts of the gastrointestinal tract. The objective of this work is the characterization, with in vitro tests, of a biomagnetic instrumentation using two 3-axis magnetoresistors arranged in a gradiometric coplanar setup to evaluate esophageal transit time, analyze and compare the results of experimental signals and the magnetic theory, as well as evaluate the instrumentation gain with use of tri-axial sensor front to the mono-axial sensor. The instrumentation is composed by two three-axis sensing magnetometers, precision power supply and amplifier electronic circuits. The sensors fixed in a coplanar setup were separate by distance of 18 cm. The sensitivity tests had been carried through using a cylindrical magnet (ø = 4 mm and h = 4 mm) of neodymium-iron-boron (grid 35). The tests were done moving the permanent magnet on the sensors parallel axis, simulating the food transit in... (Complete abstract click electronic access below)

Utilização da instrumentação virtual em Labview para criação da interface gráfica do amplificador lock-in utilizado em estudos fisiológicos a partir da comunicação via porta serial

This work presents the development of a graphical interface to the Lock-in Amplifier, which is used in physiological studies on the motility of the gastrointestinal tract in rats and signal processing. With a simple and low cost instrumentation, the resources offered by the virtual interface of LabVIEW software allows the creation of commands similar to the actual instrument that, through communication via standard serial port, transmits data between a PC and peripheral device performing specific and particular needs in the amplifier. Created for the lock-in amplifier model SR830 Stanford Research Systems, the remote manipulation gives the user greater accessibility in the process of configuration and calibration. And, since the software is installed, there is the advantage of eliminating the need of purchase new devices to upgrade the system. The commands created were made to perform six basic modifications that are used in routine of the Biomagnetism Laboratory. The instrumentation developed has the following controls: Amplitude, Frequency, Time Constant, slope low pass filter, sensitivity and offset

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)

Biosusceptometria de corrente alternada para avaliação do trânsito gastrintestinal de alimentos líquidos em ratos

The gastrointestinal tract is the main route of nutrients absorption and drugs delivery. Is important to know the parameters related to the tract, like gastric emptying and gastrointestinal transit, in order to better understand the behavior of different kind of meals or drugs passing through the GIT. Many techniques are used to study these parameters, such as manometry, scintigraphy, phenol red, activated charcoal and carbon-13 reading. However, these methods use radiation, are invasive and require animal sacrifice. As an alternative proposal, the Alternate Current Biosusceptometry (ACB), a magnetic technique, has proved to be effective for these studies with small animals, in a noninvasive way, low cost, radiation free and avoiding the animal death. Associating the ACB to magnetic micro or nanoparticles used as tracers, it is possible to observe the meal behavior inside of the GIT. Focusing meanly on liquid meals digestion, this paper had the objective to evaluate the efficiency of the ACB technique in gastric emptying and gastrointestinal transit evaluation of liquid meals in rats. To perform the experiments, magnetic nanoparticles (ferrite, MgFe2O4) were used on a 1,5 ml solution introduced by gavage on similar weight and age rats. The sensor made by 2 pairs of coils, capable of generating and detecting magnetic fields, creates a field on the interest place and when this field is in contact with the marked meal, it changes, resulting on a variation of the measured voltage. The voltage variation is analyzed and is obtained a particle concentration on the interest region. The results showed that is possible to apply the ACB technique on the GIT evaluation of liquid particles digestion, gastric emptying and meal cecum arrival time curves were obtained and from that, is possible to observe a pattern of gastrointestinal transit. Both mean process time values were acquired, proving the technique capability of ...

Avaliação gastroprotetora da epicatequina e verificação de seus mecanismos de ação

The stomach is an exceptional organ, which functions are sterilize food ingested, form the primitive bolus, digest lipids and proteins, and to store food temporarily in the gastrointestinal tract. Its capacity of digesting food without digesting itself is amazing. This fact occurs due to innumerous protective substances adjacent to the gastric mucosa. When aggressive factors overwhelm the protective factors, a lesion in the gastric mucosa is formed. Lesions that reach the lamina propria are called gastric ulcers, which are classified macroscopically as openings on the gastric wall and; microscopically, as a gastric injury characterized with epithelial desquamation, mucosal hemorrhage, glandular damage and eosinophilic infiltration. The current therapy available is effective, although it causes collateral effects, therefore researching new drugs is necessary. This work aim to evaluate the gastroprotective effect of epicatechin against gastric lesions induced by absolute ethanol and non steroidal anti-inflammatory drugs which are the main causes of this disease currently, yet we aim to study the main mechanisms of action responsible for the gastroprotective effect. The results show that epicatechin has a significant macroscopic and microscopic gastroprotective effect against gastric injuries induced by ethanol and indomethacin, acting locally by augmenting gastric mucus secretion and it also acts via antioxidant system by holding total glutathione levels. Epicatechin’s gastroprotective mechanisms depend on the activation of sulfhydryl compounds and doesn’t depend on the NO-synthase enzyme

Aplicação e viabilidade de micro-organisos potencialmente probióticos em embutido cárneo fermentado

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

Leuconostoc mesenteroides SJRP55: a potential probiotic strain isolated from Brazilian water buffalo mozzarella cheese

The probiotic potential of Leuconostoc mesenteroides subsp. mesenteroides SJRP55 isolated from water buffalo mozzarella cheese was evaluated. The microorganism presented resistance to stressful conditions that simulated the gastrointestinal tract, and to the best of our knowledge Leuconostoc mesenteroides SJRP55 was the first of this species with the ability to deconjugate bile salts. Tolerance to NaCl was temperature dependent, as well the results obtained by aggregation capacity. The strain presented good adhesion properties, β galactosidase activity, viability in fermented milk during storage, non-active against Streptococcus thermophilus and sensible to most of the tested antibiotics. Some analgesic medications inhibited the growth of the strain. Leuconostoc mesenteroides SJRP55 exhibited in vitro probiotic potential, and it can be better characterized through future in vivo tests. This bacterium presents higher functional properties compared to other studied strains, and therefore it is a potential candidate for the application as a probiotic strain, which could be used by industries in the manufacture of functional milk-based products.

Feed digestion of growing Saanen goats

Pós-graduação em Zootecnia - FCAV

Níveis e tipos de fibra dietética para suínos pesados em restrição alimentar qualitativa

Pós-graduação em Zootecnia - FCAV

Estudo dos compostos voláteis da decomposição térmica dos anti-helmínticos Albendazol e Mebendazol

The albendazole and mebendazole drugs are benzimidazole derivatives and belong to the anthelmintic class. These drugs are particularly recommended for the treatment against worms present in the gastrointestinal tract of animals and humans, by acting directly on the worm metabolism. The need for thermally study drugs is related to all the parameters that these analyzes include: presence or absence of polymorphs, possible changes in the crystallinity of the drugs, as well as the quality control during the manufacturing process thereof. In this study the thermal behavior of anthelmintic albendazole and commercial mebendazole and its recrystallisation in organic solvents, such as acetic acid and formic acid in dimethylformamide to mebendazole, and albendazole were studied using TG-DSC techniques, TG-FTIR, FTIR and XRD. TG-DSC techniques were used so it could collect information about the thermal stability of the compounds steps for thermal decomposition process and also prove its melting temperature. For recrystallization of drugs in organic solvents, the TG-DSC curves were analyzed to compare and determine that the occurrence of polymorphs. The coupled TG-FTIR technique allowed the analysis of volatile products which were released during the thermal decomposition of the commercial mebendazole. The absorption spectroscopy in the infrared region was performed to mebendazole, and albendazole in order to show the difference in functional groups of both, comparing the spectra with commercial drugs and see if there was recrystallized changes in the absorption band where the drug was recrystallized or when heated. The diffraction technique by powder X-ray method was used for comparison of the crystal structures of commercial drugs and recrystallization in organic solvents to identify changes in crystallinity both, which might suggest the formation of polymorphs

Fitogênicos ou mono e diglicerídeos associados com ácidos orgânicos em dietas para leitões recém-desmamados

Pós-graduação em Zootecnia - FCAV

Cell therapy in experimental model of inflammatory bowel disease

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Inflammatory fibroid polyp (Vanek’s polyp): a case report and literature review

Inflammatory fibroid polyp (IFP) is a benign uncommon lesion (1%-4% of gastric benign lesions), originated from the submucosa of the gastrointestinal tract. Its origin is controversial and immunohistochemical studies of lesions have largely refuted the possible vascular, neural or smooth muscle origin. Recent studies suggest a neoplastic etiology due to a mutation, in some cases, in the alpha-type platelet-derived growth factor receptor gene (PDGFRa). Our objective is to report the case of a patient aged 70 years, with gastric IFP, comparing her immunohistochemical profile with those of other studies, and a brief review of the literature.

Efeito da β-amilase e α-amilase fúngica seguido de desramificação na formação e características estruturais de amido resistente tipo 3 de batata e araruta

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)