Comparative analysis of two-dimensional electrophoresis maps (2-DE) of Helicobacter pylori from Brazilian patients with chronic gastritis and duodenal ulcer: a preliminary report

Helicobacter pylori is a bacterium recognized as the major cause of peptic ulcer and chronic gastritis. Recently, a proteome-based approach was developed to investigate pathogenic factors related to H. pylori. In this preliminary study, H. pylori strains were isolated from gastric biopsies of patients with chronic gastritis and duodenal ulcers. A partial proteomic analysis of H. pylori strains was performed by bacterial lyses and proteins were separated by two-dimensional gel electrophoresis (2-DE). A comparative analysis was performed to verify a differential protein expression between these two 2-DE maps. These data should be useful to clarify the role of different proteins related to bacterial pathogenesis. This study will be completed using a larger number of samples and protein identification of H. pylori by MALDI-TOF mass spectrometry.

Immunoblotting analyses using two-dimensional gel electrophoresis of Trypanosoma cruzi excreted-secreted antigens

Trypanosoma cruzi trypomastigotes excrete-secrete a complex mixture of antigenic molecules. This antigenic mixture denominated trypomastigote excreted-secreted antigens contains a 150-160 kDa band that shows excellent performance in Chagas' disease diagnosis by immunoblotting. The present study partially characterized by two-dimensional gel electrophoresis the immunoreactivity against the 150-160kDa protein using sera samples from chagasic patients in different phases of the disease. Trypomastigote excreted-secreted antigen preparations were subjected to high-resolution two-dimensional (2D) gel electrophoresis followed by immunoblotting with sera from chagasic and non-chagasic patients. The 150-160kDa protein presented four isoforms with isoelectric focusing ranging from 6.2 to 6.7. The four isoforms were recognized by IgM from acute phase and IgG from chronic phase sera of chagasic patients. The 150-160kDa isoform with IF of approximately 6.4 became the immunodominant spot with the progression of the disease. No cross-reactivity was observed with non-chagasic or patients infected with Leishmania sp. In this study we provide basic knowledge that supports the validation of trypomastigote excreted-secreted antigens for serological diagnosis of Chagas' disease.

Evaluation of a computer model to simulate water table response to subirrigation

The objective of this work was to evaluate the water flow computer model, WATABLE, using experimental field observations on water table management plots from a site located near Hastings, FL, USA. The experimental field had scale drainage systems with provisions for subirrigation with buried microirrigation and conventional seepage irrigation systems. Potato (Solanum tuberosum L.) growing seasons from years 1996 and 1997 were used to simulate the hydrology of the area. Water table levels, precipitation, irrigation and runoff volumes were continuously monitored. The model simulated the water movement from a buried microirrigation line source and the response of the water table to irrigation, precipitation, evapotranspiration, and deep percolation. The model was calibrated and verified by comparing simulated results with experimental field observations. The model performed very well in simulating seasonal runoff, irrigation volumes, and water table levels during crop growth. The two-dimensional model can be used to investigate different irrigation strategies involving water table management control. Applications of the model include optimization of the water table depth for each growth stage, and duration, frequency, and rate of irrigation.

Interactions of juvenile Lumbricus terrestris with adults and their burrow systems in a two-dimensional microcosm

The objective of this work was to evaluate interactions of Lumbricus terrestris juveniles with adults and with inherited burrow systems. An experiment was set up using a two dimensional Evans' boxes microcosm. Adult L. terrestris were added to 16 boxes (one individual per box) and kept in darkness at 17ºC along with eight unoccupied boxes for two months. The adult L. terrestris were removed from eight randomly selected boxes, and L. terrestris juveniles were added (one juvenile per box), composing three treatments with eight replicates: 1, with an adult in an inherited burrow (ABJ); 2, alone in an inherited burrow (BJ); and 3, alone in a previously uninhabited box (J). The proportion of juveniles occupying adult burrows observed was significantly different in treatments ABJ (48%) and BJ (75%). The mean mass of juveniles at experimental termination differed significantly among treatments and was greater in treatment J (4.04±0.39 g) in comparison to the BJ (3.09±0.93 g) and ABJ treatments (2.13±0.64 g). Results suggest a negative influence of both the presence of an adult and its burrow system on juvenile growth. Intraspecific competition partially explained this, but further investigation is required to examine how an inherited environment (i.e. burrow) could negatively affect the growth of juveniles.

Specificity and selectivity improvement in doping analysis using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry

Comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry was used for the identification of forty doping agents. The improvement in the specificity was remarkable, allowing the resolution of analytes that could not be done by one-dimensional chromatographic systems. The sensitivity observed for different classes of prohibited substances was clearly below the value required by the World Anti-Doping Agency. In addition time-of-flight mass spectrometry gives full spectrum for all analytes without any interference from the matrix, resulting in selectivity improvements. These results could support the implementation of an exhaustive monitoring approach for hundreds of doping agents in a single injection.

Solving Schrödinger equation for two dimensional potentials using supersymmetry

The formalism of supersymmetric Quantum Mechanics can be extended to arbitrary dimensions. We introduce this formalism and explore its utility to solve the Schrödinger equation for a bidimensinal potential. This potential can be applied in several systems in physical and chemistry context , for instance, it can be used to study benzene molecule.

Strain and strain rate by two-dimensional speckle tracking echocardiography in a maned wolf

The measurement of cardiovascular features of wild animals is important, as is the measurement in pets, for the assessment of myocardial function and the early detection of cardiac abnormalities, which could progress to heart failure. Speckle tracking echocardiography (2D STE) is a new tool that has been used in veterinary medicine, which demonstrates several advantages, such as angle independence and the possibility to provide the early diagnosis of myocardial alterations. The aim of this study was to evaluate the left myocardial function in a maned wolf by 2D STE. Thus, the longitudinal, circumferential and radial strain and strain rate were obtained, as well as, the radial and longitudinal velocity and displacement values, from the right parasternal long axis four-chamber view, the left parasternal apical four chamber view and the parasternal short axis at the level of the papillary muscles. The results of the longitudinal variables were -13.52±7.88, -1.60±1.05, 4.34±2.52 and 3.86±3.04 for strain (%), strain rate (1/s), displacement (mm) and velocity (cm/s), respectively. In addition, the radial and circumferential Strain and Strain rate were 24.39±14.23, 1.86±0.95 and -13.69±6.53, -1.01±0.48, respectively. Thus, the present study provides the first data regarding the use of this tool in maned wolves, allowing a more complete quantification of myocardial function in this species.

An alternative finite element formulation for determination of streamlines in two-dimensional problems

It is well known that the numerical solutions of incompressible viscous flows are of great importance in Fluid Dynamics. The graphics output capabilities of their computational codes have revolutionized the communication of ideas to the non-specialist public. In general those codes include, in their hydrodynamic features, the visualization of flow streamlines - essentially a form of contour plot showing the line patterns of the flow - and the magnitudes and orientations of their velocity vectors. However, the standard finite element formulation to compute streamlines suffers from the disadvantage of requiring the determination of boundary integrals, leading to cumbersome implementations at the construction of the finite element code. In this article, we introduce an efficient way - via an alternative variational formulation - to determine the streamlines for fluid flows, which does not need the computation of contour integrals. In order to illustrate the good performance of the alternative formulation proposed, we capture the streamlines of three viscous models: Stokes, Navier-Stokes and Viscoelastic flows.

Performance of two-dimensional Doppler echocardiography for the assessment of infarct size and left ventricular function in rats

Although echocardiography has been used in rats, few studies have determined its efficacy for estimating myocardial infarct size. Our objective was to estimate the myocardial infarct size, and to evaluate anatomic and functional variables of the left ventricle. Myocardial infarction was produced in 43 female Wistar rats by ligature of the left coronary artery. Echocardiography was performed 5 weeks later to measure left ventricular diameter and transverse area (mean of 3 transverse planes), infarct size (percentage of the arc with infarct on 3 transverse planes), systolic function by the change in fractional area, and diastolic function by mitral inflow parameters. The histologic measurement of myocardial infarction size was similar to the echocardiographic method. Myocardial infarct size ranged from 4.8 to 66.6% when determined by histology and from 5 to 69.8% when determined by echocardiography, with good correlation (r = 0.88; P < 0.05; Pearson correlation coefficient). Left ventricular diameter and mean diastolic transverse area correlated with myocardial infarct size by histology (r = 0.57 and r = 0.78; P < 0.0005). The fractional area change ranged from 28.5 ± 5.6 (large-size myocardial infarction) to 53.1 ± 1.5% (control) and correlated with myocardial infarct size by echocardiography (r = -0.87; P < 0.00001) and histology (r = -0.78; P < 00001). The E/A wave ratio of mitral inflow velocity for animals with large-size myocardial infarction (5.6 ± 2.7) was significantly higher than for all others (control: 1.9 ± 0.1; small-size myocardial infarction: 1.9 ± 0.4; moderate-size myocardial infarction: 2.8 ± 2.3). There was good agreement between echocardiographic and histologic estimates of myocardial infarct size in rats.

Comparison of diffusion models for description of osmotic dehydration of radish slices dipped in brine

ABSTRACT This paper aims at describing the osmotic dehydration of radish cut into cylindrical pieces, using one- and two-dimensional analytical solutions of diffusion equation with boundary conditions of the first and third kind. These solutions were coupled with an optimizer to determine the process parameters, using experimental data. Three models were proposed to describe the osmotic dehydration of radish slices in brine at low temperature. The two-dimensional model with boundary condition of the third kind well described the kinetics of mass transfers, and it enabled prediction of moisture and solid distributions at any given time.

Subclinical Ventricular Dysfunction Detected by Speckle Tracking Two Years after Use of Anthracycline

Background: Heart failure is a severe complication associated with doxorubicin (DOX) use. Strain, assessed by two-dimensional speckle tracking (2D-STE), has been shown to be useful in identifying subclinical ventricular dysfunction. Objectives: a) To investigate the role of strain in the identification of subclinical ventricular dysfunction in patients who used DOX; b) to investigate determinants of strain response in these patients. Methods: Cross-sectional study with 81 participants: 40 patients who used DOX ±2 years before the study and 41 controls. All participants had left ventricular ejection fraction (LVEF) ≥55%. Total dose of DOX was 396mg (242mg/ms2). The systolic function of the LV was evaluated by LVEF (Simpson), as well as by longitudinal (εLL), circumferential (εCC), and radial (εRR) strains. Multivariate linear regression (MLR) analysis was performed using εLL (model 1) and εCC (model 2) as dependent variables. Results: Systolic and diastolic blood pressure values were higher in the control group (p < 0.05). εLL was lower in the DOX group (-12.4 ±2.6%) versus controls (-13.4 ± 1.7%; p = 0.044). The same occurred with εCC: -12.1 ± 2.7% (DOX) versus -16.7 ± 3.6% (controls; p < 0.001). The S’ wave was shorter in the DOX group (p = 0.035). On MLR, DOX was an independent predictor of reduced εCC (B = -4.429, p < 0.001). DOX (B = -1.289, p = 0.012) and age (B = -0.057, p = 0.029) were independent markers of reduced εLL. Conclusion: a) εLL, εCC and the S’ wave are reduced in patients who used DOX ±2 years prior to the study despite normal LVEF, suggesting the presence of subclinical ventricular dysfunction; b) DOX was an independent predictor of reduced εCC; c) prior use of DOX and age were independent markers of reduced εLL.

Prenatal diagnosis of Beckwith-Wiedemann syndrome by two- and three-dimensional ultrasonography

Beckwith-Wiedemann syndrome is a genetic syndrome characterized by macroglossia, omphalocele, fetal gigantism and neonatal hypoglycemia. The authors report a case of Beckwith-Wiedemann syndrome diagnosed in a 32-year-old primigravida in whom two-dimensional ultrasonography revealed the presence of abdominal wall cyst, macroglossia and polycystic kidneys. Three-dimensional ultrasonography in rendering mode was of great importance to confirm the previous two-dimensional ultrasonography findings.

Comparison of Two- and Three-dimensional Ultrasonography in the Evaluation of Lesion Level in Fetuses with Spina Bifida

Purpose To evaluate the precision of both two- and three-dimensional ultrasonography in determining vertebral lesion level (the first open vertebra) in patients with spina bifida. Methods This was a prospective longitudinal study comprising of fetuses with open spina bifida who were treated in the fetal medicine division of the department of obstetrics of Hospital das Clínicas of the Universidade de São Paulo between 2004 and 2013. Vertebral lesion level was established by using both two- and three-dimensional ultrasonography in 50 fetuses (two examiners in each method). The lesion level in the neonatal period was established by radiological assessment of the spine. All pregnancies were followed in our hospital prenatally, and delivery was scheduled to allow immediate postnatal surgical correction. Results Two-dimensional sonography precisely estimated the spina bifida level in 53% of the cases. The estimate error was within one vertebra in 80% of the cases, in up to two vertebrae in 89%, and in up to three vertebrae in 100%, showing a good interobserver agreement. Three-dimensional ultrasonography precisely estimated the lesion level in 50% of the cases. The estimate error was within one vertebra in 82% of the cases, in up to two vertebrae in 90%, and in up to three vertebrae in 100%, also showing good interobserver agreement. Whenever an estimate error was observed, both two- and three-dimensional ultrasonography scans tended to underestimate the true lesion level (55.3% and 62% of the cases, respectively). Conclusions No relevant difference in diagnostic performance was observed between the two- and three-dimensional ultrasonography. The use of three-dimensional ultrasonography showed no additional benefit in diagnosing the lesion level in the fetuses with spina bifida. Errors in both methods showed a tendency to underestimate lesion level.

BEM/FEM non-linear model applied to transient analysis with viscous damping

In this article a two-dimensional transient boundary element formulation based on the mass matrix approach is discussed. The implicit formulation of the method to deal with elastoplastic analysis is considered, as well as the way to deal with viscous damping effects. The time integration processes are based on the Newmark rhoand Houbolt methods, while the domain integrals for mass, elastoplastic and damping effects are carried out by the well known cell approximation technique. The boundary element algebraic relations are also coupled with finite element frame relations to solve stiffened domains. Some examples to illustrate the accuracy and efficiency of the proposed formulation are also presented.

A spheroid-based 3-D culture model for pancreatic cancer drug testing, using the acid phosphatase assay

Current therapy for pancreatic cancer is multimodal, involving surgery and chemotherapy. However, development of pancreatic cancer therapies requires a thorough evaluation of drug efficacy in vitro before animal testing and subsequent clinical trials. Compared to two-dimensional culture of cell monolayer, three-dimensional (3-D) models more closely mimic native tissues, since the tumor microenvironment established in 3-D models often plays a significant role in cancer progression and cellular responses to the drugs. Accumulating evidence has highlighted the benefits of 3-D in vitro models of various cancers. In the present study, we have developed a spheroid-based, 3-D culture of pancreatic cancer cell lines MIAPaCa-2 and PANC-1 for pancreatic drug testing, using the acid phosphatase assay. Drug efficacy testing showed that spheroids had much higher drug resistance than monolayers. This model, which is characteristically reproducible and easy and offers rapid handling, is the preferred choice for filling the gap between monolayer cell cultures and in vivo models in the process of drug development and testing for pancreatic cancer.