In Vitro and In Vivo Evaluation of Magnetic Floating Dosage Form by Alternating Current Biosusceptometry.

Floating controlled systems seek to extend the gastric retention time (GRT) of solid pharmaceutical forms by sustaining buoyancy in the stomach without affecting gastric emptying rates. This investigation aimed to evaluate a magnetic floating drug delivery system (MFDDS) under diverse physiological conditions (pressure and viscosity) using an Alternating Current Biosusceptometry (ACB) system by conducting assessments in vitro and in vivo. For in vitro experiments, MFDDSs were placed under different pressures (760, 910, and 1060 mmHg) and viscosities (1, 50, 120, and 320 mPa·s) for evaluation of floating lag time (FLT).

Gastric plication surgery changes gastrointestinal and metabolic parameters in an obesity-induced high-fat diet model.

Background: Obesity treatment includes less invasive procedures such as gastric plication (GP) surgery; however, its effects on gastrointestinal (GI) motility parameters are underestimated. We aimed to verify the metabolic and gastrointestinal effects of GP surgery in the rat obesity model.

Methods: A high-fat diet-induced obesity was used.

Classification of gastric emptying and orocaecal transit through artificial neural networks.

Classical quantification of gastric emptying (GE) and orocaecal transit (OCT) based on half-life time T$ _{50} $, mean gastric emptying time (MGET), orocaecal transit time (OCTT) or mean caecum arrival time (MCAT) can lead to misconceptions when analyzing irregularly or noisy data. We show that this is the case for gastrointestinal transit of control and of diabetic rats. Addressing this limitation, we present an artificial neural network (ANN) as an alternative tool capable of discriminating between control and diabetic rats through GE and OCT analysis.

2D Quantitative Imaging of Magnetic Nanoparticles by an AC Biosusceptometry Based Scanning Approach and Inverse Problem.

The use of magnetic nanoparticles (MNPs) in biomedical applications requires the quantitative knowledge of their quantitative distribution within the body. AC Biosusceptometry (ACB) is a biomagnetic technique recently employed to detect MNPs in vivo by measuring the MNPs response when exposed to an alternate magnetic field. The ACB technique presents some interesting characteristics: non-invasiveness, low operational cost, high portability, and no need for magnetic shielding.

New device for active gastric mechanical stimulation.

Background: Gastroparesis is a chronic stomach disorder and effective treatment is the aim of different strategies. Alternative therapies consist of an electrical stimulation of the stomach to evoke a response in the gastric activity. We present the development and in vivo application of an electromagnet system to induce a mechanical stimulus in the stomach aiming for gastric contractile responses.

Inflammatory lesions and brain tumors: is it possible to differentiate them based on texture features in magnetic resonance imaging?

Background: Neuroimaging strategies are essential to locate, to elucidate the etiology, and to the follow up of brain disease patients. Magnetic resonance imaging (MRI) provides good cerebral soft-tissue contrast detection and diagnostic sensitivity. Inflammatory lesions and tumors are common brain diseases that may present a similar pattern of a cerebral ring enhancing lesion on MRI, and non-enhancing core (which may reflect cystic components or necrosis) leading to misdiagnosis.

Gastrointestinal motility and morphology in mice: Strain-dependent differences.

Background: BALB/c and C57BL/6 mice are widely used in biomedical research; however, the differences between strains are still underestimated. Our aims were to develop an experimental protocol to evaluate the duodenal contractility and gastrointestinal transit in mice using the Alternating Current Biosusceptometry (ACB) technique and to compare gastrointestinal motor function and morphology between BALB/c and C57BL/6 strains.

Methods: Male mice were used in experiments (a) duodenal contractility: animals which had a magnetic marker surgically fixed in the duodenum to determine the frequency and amplitude of contractions and (b) gastrointestinal transit: animals which ingested a magnetically marked chow to calculate the Oro-Anal Transit Time (OATT) and the Fecal Pellet Elimination Rate (FPER).

A lung image reconstruction from computed radiography images as a tool to tuberculosis treatment control.

Background: Background: Tuberculosis (TB) is an infectious lung disease with high worldwide incidence that severely compromises the quality of life in affected individuals. Clinical tests are currently employed to monitor pulmonary status and treatment progression. The present study aimed to apply a three-dimensional (3D) reconstruction method based on chest radiography to quantify lung-involvement volume of TB acute-phase patients before and after treatment.

Computed tomography-based volumetric tool for standardized measurement of the maxillary sinus.

Volume measurements of maxillary sinus may be useful to identify diseases affecting paranasal sinuses. However, literature shows a lack of consensus in studies measuring the volume. This may be attributable to different computed tomography data acquisition techniques, segmentation methods, focuses of investigation, among other reasons.

Gastrointestinal disorders after immunosuppression: an experimental model to evaluate the influence of monotherapy on motility parameters.

What is the central question of this study? The aim was to propose an animal model for investigating the effects of immunosuppressive monotherapy on gastrointestinal motility using a non-invasive biomagnetic technique. What is main finding and its importance? In our experimental study, immunosuppressive drugs currently in use accelerated gastric emptying whilst increasing the frequency and amplitude of gastric contractions after treatment, except for Mycophenolate and azathioprine. Alternating current biosusceptometry is a useful tool to evaluate side-effects of drugs on the gastrointestinal tract, which will help in understanding the symptoms and improving clinical management of patients.

Homogeneous Canine Chest Phantom Construction: A Tool for Image Quality Optimization.

Digital radiographic imaging is increasing in veterinary practice. The use of radiation demands responsibility to maintain high image quality. Low doses are necessary because workers are requested to restrain the animal.

Construction of pediatric homogeneous phantoms for optimization of chest and skull radiographs.

Objectives: To develop two pediatric patient-equivalent phantoms, the Pediatric Chest Equivalent Patient (PCEP) and the Pediatric Skull Equivalent Patient (PSEP) for children aged 1 to 5 years. We also used both phantoms for image quality evaluations in computed radiography systems to determine Gold Standard (GS) techniques for pediatric patients.

Methods: To determine the simulator materials thickness (Lucite and aluminum), we quantified biological tissues (lung, soft, and bone) using an automatic computational algorithm.

Wavelet-based algorithm to the evaluation of contrasted hepatocellular carcinoma in CT-images after transarterial chemoembolization.

Background: Hepatocellular carcinoma is a primary tumor of the liver and involves different treatment modalities according to the tumor stage. After local therapies, the tumor evaluation is based on the mRECIST criteria, which involves the measurement of the maximum diameter of the viable lesion. This paper describes a computed methodology to measure through the contrasted area of the lesions the maximum diameter of the tumor by a computational algorithm.

Erythromycin versus neomycin in the treatment of hepatic encephalopathy in cirrhosis: a randomized double-blind study.

Background: Hepatic encephalopathy (HE) is a severe complication in patients with hepatic cirrhosis, which causes numerous hospital admissions and deaths. Antibiotics are the best options in HE treatment, but head-to-head comparisons between these drugs are scarce. Erythromycin combines the antimicrobial effect and prokinetic properties in the same drug, but it has never been used in HE treatment.

A novel device with 36 channels for imaging and signal acquisition of the gastrointestinal tract based on AC biosusceptometry.

The alternate current biosusceptometry (ACB) is a biomagnetic technique used to study some physiological parameters associated with gastrointestinal (GI) tract. For this purpose it applies an AC magnetic field and measures the response originating from magnetic marks or tracers. This paper presents an equipment based on the ACB which uses anisotropic magnetoresistive (AMR) sensors and an inexpensive electronic support.

Magnetoresistive sensors in a new biomagnetic instrumentation for applications in gastroenterology.

Anisotropic Magnetoresistive (AMR) sensors shows a new possibility to detect magnetic fields produced by magnetic particles present in the gastrointestinal (GI) tract. A system that uses excitation and detection of magnetic field was developed using AMR sensor. A magnetic flux concentrator was also studied to increase the sensitivity of AMR in this work.

A novel biomagnetic instrumentation with four magnetoresistive sensors to evaluate gastric motility.

A novel instrumentation using anisotropic magnetoresistive (AMR) sensors associated with magnetic coils excitation was developed to evaluate gastrointestinal tract motility parameters. The susceptometer has four sensors that were used to measure the gastric activity contractions (GAC) in anaesthetized dogs, its performance was evaluated by manometry with good results.

Gastrointestinal transit and disintegration of enteric coated magnetic tablets assessed by ac biosusceptometry.

The oral administration is a common route in the drug therapy and the solid pharmaceutical forms are widely used. Although much about the performance of these formulations can be learned from in vitro studies using conventional methods, evaluation in vivo is essential in product development. The knowledge of the gastrointestinal transit and how the physiological variables can interfere with the disintegration and drug absorption is a prerequisite for development of dosage forms.