Update on the Diagnostic Pitfalls of Autopsy and Post-Mortem Genetic Testing in Cardiomyopathies

Inherited cardiomyopathies are frequent causes of sudden cardiac death (SCD), especially in young patients. Despite at the autopsy they usually have distinctive microscopic and/or macroscopic diagnostic features, their phenotypes may be mild or ambiguous, possibly leading to misdiagnoses or missed diagnoses. In this review, the main differential diagnoses of hypertrophic cardiomyopathy (e.g., athlete’s heart, idiopathic left ventricular hypertrophy), arrhythmogenic cardiomyopathy (e.g., adipositas cordis, myocarditis) and dilated cardiomyopathy (e.g., acquired forms of dilated cardiomyopathy, left ventricular noncompaction) are discussed. Moreover, the diagnostic issues in SCD victims affected by phenotype-negative hypertrophic cardiomyopathy and the relationship between myocardial bridging and hypertrophic cardiomyopathy are analyzed. Finally, the applications/limits of virtopsy and post-mortem genetic testing in this field are discussed, with particular attention to the issues related to the assessment of the significance of the genetic variants.     

Feasibility of fishmeal replacement by shrimp head silage protein hydrolysate in Nile tilapia (Oreochromis niloticus L) diets

This study provides information on the use of shrimp head silage protein hydrolysate (SPH) as an alternative protein source for tilapia feeding. Six diets (28% protein, 12% lipid) were prepared where fishmeal protein was replaced at levels of 0 (control), 10, 15, 20, 25 and 30% with the hydrolysate. The diets were supplied to Nile tilapia fry (338 mg initial weight) stocked in plastic recirculating 20 l tanks (10 animals per tank), with three replicates per treatment. After an 8 week experimental period, fish fed the diets containing 10 and 15% SPH showed significantly better performance in terms of final body weight, weight gain (%), mean daily weight gain (mg day^?1), specific growth ratio and feed conversion ratio than those fed the control diet (fishmeal as protein source) and higher‐SPH diets. It is concluded that shrimp head hydrolysate is a promising alternative protein source for tilapia feeding, improving growth ratio at dietary inclusion levels as high as 15%. In addition, the diets with added shrimp silage protein were well accepted by the fish, which avidly consumed the feed during the experiment. © 2002 Society of Chemical Industry     

Mining data from intensive care patients

In this paper we describe the application of data mining methods for predicting the evolution of patients in an intensive care unit. We discuss the importance of such methods for health care and other application domains of engineering. We argue that this problem is an important but challenging one for the current state of the art data mining methods and explain what improvements on current methods would be useful. We present a promising study on a preliminary data set that demonstrates some of the possibilities in this area.     

Robustness of VS-MRAC with respect to unmodelled dynamics and external disturbances

A variable structure model reference adaptive controller (VS-MRAC) using only input and output measurements was recently proposed and shown to be globally asymptotically stable with superior transient behaviour and disturbance rejection properties. In this paper a singular perturbation approach is used in order to establish the robustness of the controller in the presence of unmodelled dynamics (parasitics) and disturbances. We develop a new Lyapunov-based technique to analyse the overall system and show that for sufficiently small parasitics the system remains stable and the output error is small in some sense.     

Chronic liver disease in Peru: role of viral hepatitis

Autologous or glutaraldehyde treated bovine pericardial valved patch was utilized for widening of the right ventricular outflow tract in 20 patients with tetralogy of Fallot (autologous pericardium group in 10 patients and bovine pericardium group in 10). Pericardial valve function of the both materials was evaluated by postoperative cardiac catheterization performed 1 year after the operation. There were no significant differences in pulmonary arterial and right ventricular pressures, and right ventricular ejection fraction and end-diastolic volume between the 2 groups. Pulmonary angiogram in the autologous pericardium group patients demonstrated the pulmonary regurgitation (PR) of grade 1 in 5 patients, grade 2 in 4 and grade 3 in 1. On the other hand, 1, 3 and 6 patients in the bovine pericardium group demonstrated no-PR, grade 1 PR and grade 2 PR, respectively. It was concluded that there were no significant differences between autologous and glutaraldehyde treated bovine pericardium as a material of valved patch for widening of the right ventricular outflow tract of tetralogy of Fallot.     

A computational study of LP-based heuristic algorithms for two-dimensional guillotine cutting stock problems

In this paper we develop and compare several heuristic methods for solving the general two-dimensional cutting stock problem. We follow the Gilmore-Gomory column generation scheme in which at each iteration a new cutting pattern is obtained as the solution of a subproblem on one stock sheet. For solving this subproblem, in addition to classical dynamic programming, we have developed three heuristic procedures of increasing complexity, based on GRASP and Tabu Search techniques, producing solutions differing in quality and in time requirements. In order to obtain integer solutions from the fractional solutions of the Gilmore-Gomory process, we compare three rounding procedures, rounding up, truncated branch and bound and the solution of a residual problem. We have coded and tested all the combinations of algorithms and rounding procedures. The computational results obtained on a set of randomly generated test problems show their relative efficiency and allow the potential user to choose from among them, according to the available computing time. Rceived: January 9, 2001 / Accepted: December 10, 2001     

An iterative penalty method for the finite element solution of the stationary Navier-Stokes equations

The objective of this paper is to analyse an iterative procedure for the finite element solution of the Stokes and Navier-Stokes stationary problems. For the latter case, the usual condition on the viscosity and the data that ensures uniqueness is assumed. The method is based on the iterative imposition of the incompressibility condition via penalization. Theoretical and numerical results show that this constraint can be approximated iteratively within the same iterative loop used to deal with the nonlinear term of the equations. Two particular iterative schemes are analysed, namely those based on the Picard and Newton-Raphson algorithms.     

WO3 pillar-type and helical-type thin film structures to be used in microbatteries

In the present study WO₃ thin films were deposited by sputtering onto ITO glass, W/ITO and Si substrates by using the glancing angle deposition (GLAD) technique, with the objective of applying these materials in electrochemical intercalation devices. The thin films microstructure and electrochemical behavior were determined through scanning electron microscopy (SEM) and cycling at constant current with potential limitation. By mainly adjusting the substrate holder speed rotation, pillar-type and helical-type structures were obtained under high and low speed rotation levels, respectively. The electrochemical results showed that the best charge capacity performance was obtained for the WO₃/W/ITO films with pillar-type structures, which are more porous.     

A study of the impact of instability on relative permeability and capillary pressure

Because of the rapid changes in saturation which take place in the immediate vicinity of a displacement front, it is not possible to estimate relative permeabilities over the entire saturation range of interest when using the external-drive method. It is demonstrated in this study that this limitation can be removed, if data from an unstabilized and/ or unstable displacement are used. Furthermore, it is shown that use of such data is permissible, provided: (a) saturation profiles and pressure gradients in both phases can be measured directly; (b) the external-drive theory is modified to account for the existence of capillary pressure gradients; and (c) the analysis is carried out from a Lagrangian rather than a Eulerian point of view.A comparison of relative permeabilities obtained by using the Lagrangian method with those obtained using the conventional (without capillary pressure term) and the modified (with the capillary pressure term) Eulerian methods was undertaken to demonstrate the effect of the neglect of the capillary pressure term on relative permeabilities. Also investigated in this study was the impact of instability on the relative permeability and capillary pressure curves for unstable displacements and the effect of instability on the saturation profiles, fractional flow curves and the residual oil saturation. In addition, the effect of instability on the residual oil saturation was studied.