Humoral immune response to the Trypanosoma cruzi complement regulatory protein as an indicator of parasitologic clearance in human Chagas' disease

Immunoprecipitation of the purified 160-kDa complement regulatory protein of Trypanosoma cruzi by Chagas' disease patient sera was examined as a possible correlate of the complement-mediated lysis test and as an indicator of parasite clearance. The results presented demonstrate that assessment of the humoral response to this antigen is a useful indicator of parasite clearance and may be particularly helpful in the assessment of some patients for whom other serological tests produce ambiguous results.     

A comparative study on the synthesis of the natriuretic hormone dopamine in OK and LLC-PK1 cells

The Vmax values (in nmol/mg protein/15 min) for AAAD in OK cells (0.94 +/- 0.08) were found to be significantly (P < 0.01) lower than those observed in LLC-PK1 cells (4.37 +/- 0.08). However, in both cell lines decarboxylation reaction was a saturable process with similar K(m) values (OK cells = 1.1 mM (0.3, 1.8); LLC-PK1 cells = 1.8 mM (1.6, 2.1)). Contrariwise to OK cells, decarboxylation of L-DOPA to dopamine in LLC-PK1 cells followed a linear (7.6 +/- 0.1 pmol/mg protein/min) non-saturable kinetics till 120 min of incubation. The formation of dopamine from increasing concentrations of L-DOPA (10 to 500 microM) followed a non-linear kinetics in both cell lines; the process of L-DOPA decarboxylation was saturated at low concentrations of L-DOPA with an apparent K(m) value of 11 microM (0.2, 22.6) in OK cells and 27.4 microM (11.1, 43.7) in LLC-PK1 cells. The formation of dopamine in LLC-PK1 cells (Vmax = 2097 +/- 113 pmol/mg protein/6 min) was 13.7-fold that occurred in OK cells (Vmax = 153 +/- 10 pmol/mg protein/6 min). In conclusion, LLC-PK1 cells appear to be endowed with a greater ability to form dopamine from exogenous L-DOPA when compared to OK cells.     

Organisational spaces and intelligent machines: A metaphorical approach to ethics

This paper tackles the main changes that have taken place in the mechanical worldview of simple, self-regulating and intelligent machines, and studies their repercussions at the ethical and organisational level. These views of machines agree with the scientific, human-relations and postmodern proposals in organisation theory, in that they are in fact reflections on human nature which depend on metaphorical devices within which the machine metaphor is central.If we were only to govern our actions by the reflection of the inert world's irrevocable laws in our own consciousness, we would be completely unmoral, or to put it better, amoral; Good and Bad would lack meaning for us... A. Caso A System is an imaginary machine... A. Smith     

Low-dose steroids reduce flu-like symptoms at the initiation of IFNbeta-1b in relapsing-remitting MS

To determine whether low-dose prednisone reduces flu-like symptoms at the initiation of interferon beta 1-b (IFNbeta-1b), we studied 71 patients with clinically definite, relapsing-remitting multiple sclerosis who were started on IFNbeta-1b. Patients were randomized to receive prednisone plus paracetamol or only paracetamol and were monitored for side effects. Systemic side effects were minimal in the steroid group compared with the nonsteroid group during the first 15 days of treatment (p=0.005). At 3 months, both groups showed a similar frequency of flu-like symptoms. No differences in local reaction between the two groups were observed throughout the study.     

CB1 cannabinoid receptor antagonist-induced opiate withdrawal in morphine-dependent rats

Recent reports have provided evidence of a link between the endogenous brain cannabinoid system and the endogenous central opioid systems. Here we report that the selective CB1 receptor antagonist SR 141716A induced behavioral and endocrine alterations associated with opiate withdrawal in morphine-dependent animals in a dose-dependent manner and that naloxone induced an opiate withdrawal syndrome in animals made cannabinoid-dependent by repeated administration of the potent cannabinoid agonist HU-210. Additionally CB1 and mu-opioid receptor mRNAs were co-localized in brain areas relevant for opiate withdrawal such as the nucleus accumbens, septum, dorsal striatum, the central amygdaloid nucleus and the habenular complex. These results suggest that CB1 cannabinoid receptors may play a role in the neuroadaptive processes associated with opiate dependence, and they lend further support for the hypothesis of a potential role of cannabinoid receptors in the neurobiological changes that culminate in drug addiction.     

Health habits of health professionals

The conduct of medical professionals is an important educational point of reference for the many people who see and know them. Nurses and other medical workers are often role models in which their daily health habits may be imitated by their patients, family of friends. With this in mind a study, based on a previously published work in the United States (Health Practices of Nursing Students), was performed to determine, first, if the daily habits of nurses are indeed healthy and adequate to communicate a salubrious lifestyle; second, to see if this group considers themselves capable and responsible for changing those unsanitary habits that they do have. Results of the surveys of 125 subject nurses from the University of Navarra indicate that there is a great amount of consciousness regarding the danger of most unsanitary habits and the need to avoid them, although many of them remain firmly entrenched in their daily lives. The percentage of nurses who felt capable or responsible for changing unhealthy practices was low (67.5%).     

A numerical study on low and higher-order potential based BEM for 2D inviscid flows

A formal error analysis of the order of approximation of a potential based boundary element method (BEM) for two-dimensional flows is performed in order to derive consistent approximations for the potential integrals. Two higher-order approaches satisfying consistency requirements to attain second and third order convergence in the potential are selected for numerical implementation. From the formal local expansions of the potential integrals the influence coefficients are derived and evaluated analytically. In order to assess the methods accuracy, the low and higher-order methods are applied to two-dimensional steady flows around analytical foils. A numerical error analysis is done and a comparison between their theoretical and numerical asymptotic order of accuracy performed. The first author acknowledges the financial support granted by Fundação para a Ciência e a Tecnologia, Ph.D. grant PRAXISXXI/BD/2226/99. This work was done under the project PRAXIS/2/2.1/MAR/1723/95.     

Reliability-based optimum design of cable-stayed bridges

This paper presents a procedure for finding the reliability-based optimum design of cable-stayed bridges. The minimisation problem is stated as the minimisation of stresses, displacements, reliability and bridge cost. A finite-element approach is used for structural analysis. It includes a direct analytic sensitivity analysis module, which provides the structural behaviour responses to changes in the design variables. An equivalent multicriteria approach is used to solve the non-differentiable, non-linear optimisation problem, turning the original problem into the sequential minimisation of unconstrained convex scalar functions, from which a Pareto optimum is obtained. Examples are given illustrating the procedure.     

Prospective comparison of four lymphoblastoid interferon alpha schedules for chronic hepatitis C. A multivariate analysis of factors predictive of sustained response to treatment

OBJECTIVE: Interferon alpha (IFN-alpha) provides effective treatment in some patients with chronic hepatitis C. Since this drug is costly and causes potentially severe side effects, there is a need for clarification of the optimal dose regimen and treatment duration and of the predictive factors of long-term response to this therapy. DESIGN: Prospective, randomized study in patients with chronic hepatitis C. SETTING: 'Crespi' Division of Medicine and Centre for Liver Diseases, Niguarda Hospital, Milan, Italy. PATIENTS AND METHODS: One hundred and forty-two patients with chronic hepatitis C were randomized to receive IFN-alpha at a dosage of 2-4 mega units/square metre of body surface area thrice weekly for 6-12 months. Eleven baseline variables that might predict sustained response to IFN-alpha were evaluated in this series. Sustained response was defined as normalization of transaminase levels observed by the fourth month of therapy and lasting for at least 6 months after treatment withdrawal. RESULTS: According to univariate analysis, variables significantly associated with sustained response to treatment were: hepatitis C virus (HCV) genotype, treatment duration, serum HCV-RNA level and duration of hepatitis. On multivariate analysis only two of these variables were found to be independently associated with sustained response to IFN-alpha: HCV genotype (P < 0.0001) and treatment duration (P = 0.0015). In the patients infected with genotype 1b, IFN-alpha was effective only when administered at the higher dosage and for the longer period. CONCLUSION: Viral genotype and treatment duration are independently related to sustained response to IFN-alpha in patients with chronic hepatitis C. The patients infected with HCV genotype 1b should receive IFN-alpha at the higher dosage and for the longer period.     

The influence of carrageenan on the properties of low-fat frankfurters

Research was undertaken to study the technological properties of six carrageenan fractions and their usefulness as fat substitutes in frankfurter type sausages. In the first stage of the experiment hardness of gels made of 3% solutions of carrageenan preparations with different pH (5.5, 6.0 and 6.5) was evaluated. The highest F_max. values were noted in gels obtained from G-WG carrageenan (kappa I fraction). In the second stage of the study frankfurter type sausages were produced, containing 20% and 10% of fat in meat batter with or without (control) kappa I carrageenan (G-WG). Carrageenan as a fat substitute caused a reduction in cooking and storage weight losses, increased hardness, gumminess and chewiness. All frankfurters produced with carrageenan, irrespective of fat content, were characterized by significantly higher sensory evaluation scores for texture, color and taste in comparison to control sausages.