Effect of electrode impedance in improved buffer amplifier for bioelectric recordings

We analysed the effects of electrode impedance on the transfer response of a one-stage improved buffer amplifier. The electrode DC resistance (R(d)) modifies the one-stage buffer transfer response. We found a limit electrode resistance (R(d(lim))) which depends on the transfer damping factor (epsilon). If R(d) is lower than 86.5 komega, the transfer response of the buffer fulfils American Heart Association (AHA) recommendations, but when R(d) is greater than R(d(lim)) it must be cautiously weighed up because its influence in the transfer response becomes appreciable. The maximum R(d) that can be driven by the buffer is 1.2 Momega. Higher values do not fulfil AHA recommendations. Therefore, electrodes with higher impedance should not be used with this kind of buffer. In contrast, when this buffer is used to build in an instrumentation amplifier (IA) for bipolar recording, the common-mode rejection ratio (CMRR) is sensitive to the electrode type used.     

Hyperprolactinemia in patients on antipsychotic drugs causes ADP-stimulated platelet activation that might explain the increased risk for venous thromboembolism: pilot study

Recently, an increased risk of venous thromboembolism in patients on antipsychotic drugs has been reported, but the molecular etiology is still unknown. Most antipsychotic drugs act as dopamine antagonists, and some of them cause hyperprolactinemia. Hyperprolactinemia has recently been found to cause increased platelet activation via potentiating ADP effects on human platelets. We assessed prolactin values as well as ADP-stimulated and thrombin receptor activator 6-stimulated expression of the platelet activation marker P-selectin in 20 consecutive patients under therapy with antipsychotic drugs. We detected a significant correlation between prolactin values and ADP-stimulated P-selectin expression on platelets in patients on antipsychotic drugs, revealing a significant higher platelet stimulation in hyperprolactinemic patients on antipsychotic drugs than in normoprolactinemic controls. Therefore, hyperprolactinemia might be the yet unknown acquired risk factor in patients on antipsychotic drugs explaining the increased risk for venous thromboembolism in these patients.     

Influence of lidocaine on ouabain-induced inotropic response in rat atria

In this paper we demonstrated that lidocaine broadens the therapeutic range of ouabain action having a protective effect on ouabain-induced toxicity on rat atria. The lidocaine effect on therapeutic ouabain action was associated with the increase in the sensitivity of Na(+)-K(+)-ATPase related to a decreased in the equilibrium dissociation constant (K(d)) of high affinity binding sites. Lidocaine suppressed the ouabain-induced tonotropic effect and arrhythmias, decreasing the number of low affinity binding sites (B(max)) without changes in K(d). Blockade of Na(+)-Ca(2+) exchange with KB-R7943 or dual Na(+)-Ca(2+) channel with flunarizine, mimicked lidocaine effect increasing ouabain therapeutic action, extending its concentration range tolerated, delaying the onset of contracture. Lidocaine itself triggered negative inotropic response at high concentration. This effect was increased in the presence of flunarizine and verapamil but not by the inhibition of calcium/calmodulin with W-7. The mechanism underlying the lidocaine-induced negative inotropic response, appears to be different that underlying the positive inotropic effect on ouabain action. This study provides evidence that lidocaine can interact with the same or similar binding sites for ouabain in rat atrial tissue, providing a protective effect on ouabain-induced changes in contractility. The contribution of Na(+)-Ca(2+) exchange and/or Ca(2+) overload on lidocaine effect is discussed.     

Development and application of the mania rating guide (MRG)

In this article we present the development and application of the Mania Rating Guide (MRG), a semi-structured interview. This guide was created in order to assist the filling of three mania Scales: Mania Rating Scale, Bech-Rafaelsen Mania Scale and Clinician-Administered Rating Scale for Mania. The MRG consists of twenty-one Psychopathological Dimensions, that correspond to the Items of the original Scales, and are structured in Questions. The guide was applied to fifteen manic patients admitted in the Psychiatric Unit of the Clinical Hospital of Porto Alegre. A psychiatrist interviewed them using the MRG, and the interviews were videotaped. Afterwards, three independent raters scored the Mania scales based on the films. The impression of the raters was that the MRG allows not only to easily score all the Items of the Scales but also to cover the wide spectrum of the symptomatological presentation of a manic syndrome.     

Expression and immunogenicity of the major house dust mite allergen Der p 1 following DNA immunization

The mite protein Der p 1 is a major trigger of allergy and atopic asthma world-wide, and thus, a good vaccine candidate for allergy prevention. Since it is a cysteine protease, the catalytic effects of Der p 1 vaccination may be unpredictable. One approach to reduce this risk is to vaccinate with DNA encoding enzymatically inactive forms of Der p 1. Here we show that Der p 1 DNA without its native pre-pro sequences potently induced Der p 1-specific antibodies, as long as its pre-sequence was substituted by another leader sequence. Without any pre-pro sequence, the same DNA fragment was well expressed but failed to induce significant level of anti-Der p 1 antibodies, without further boosting by protein.     

Chitosan nanoparticles containing plasmid DNA encoding house dust mite allergen,Der p 1 for oral vaccination in mice

Our previous studies indicated that intramuscular (i.m.) immunisation with full length Der p 1 cDNA induced significant humoral response to the left domain (approximately corresponding to amino acids 1-116) but not to the right domain (approximately corresponding to amino acids 117-222) of Der p 1 allergen. This study explored the use of chitosan-DNA nanoparticles for oral immunisation to induce immune responses specific to both the left and right domains of Der p 1. DNA constructs pDer p 1 (1-222) and pDer p 1 (114-222) were complexed with chitosan and delivered orally followed by an i.m. injection of pDer p 1 (1-222) 13 weeks later. Such approach has successfully primed Th1-skewed immune responses against both domains of Der p 1. This strategy could be further optimised for more efficacious gene vaccination for full length Der p 1.     

Health organizations from the perspective of complex care system

The construction of new practices of care presupposes a new look for the health organizations. The objective of this text is to interpret the complexity theme in health and in Nurse fields in the care systems perspective, in order to promote a reflection of the practices of care in the health organizations context. The complex thought brings a new way to conceive the action and the human condition under different perspectives. It appears as a possibility for the visualization of a care system as a complex system in your structures and properties, in the movements of interretroactions in the organizational spaces and in possible auto-organizers processes. It is hoped a transforming action of the health organizations that considers the ambiguities, the uncertainties and the contemporary social dynamics for a healthier living.     

Caretaking as articulation work: the effects of taking up responsibility for a child with asthma on labor force participation

A well-established quantitative literature has documented the financial toll for women's caretaking. Still, we do not know much about the process by which women end up taking on an extensive caretaking role and what they do on a daily basis. Based on in-depth interviews with a convenience sample of fifty caretakers of school aged children with asthma and nine health professionals in the USA, this study examines how health professionals socialize mothers into an intensive caretaking role for their children with asthma, how mothers negotiated and perform that role, and the impact of care work on their labor force participation. Care providers assign broad caretaking tasks that require further articulation work to get the job done. Although mothers care for their children in varied ways, caring for a child with a chronic disease remains a time-consuming activity. Mothers pay a price for the indeterminate nature of articulation work by scaling back their involvement in the paid labor force.     

The Socio-economic Impact of Bariatric Surgery

Introduction

A recurring argument for bariatric surgery is cost savings due to sustained weight loss and reductions in comorbidities. However, studies prompting this argument tend to focus only on health care costs, and in some of them, cost changes after surgery have been modelled. The aim of this study was to generate real-world evidence on the socio-economic impact of bariatric surgery, by evaluating the effect on both direct and indirect costs.

Materials and Methods

Using real-world data from national registries, predictions of health care costs, social transfer payments and income were performed for a surgically treated individual and compared to those for a similar but non-surgically treated individual 3 years before and after surgery. Secondly, the relative risks for health care costs, social transfer payments and income of a surgical group compared with a non-surgical group were estimated. The non-surgical group was defined as being eligible for bariatric surgery but not undergoing it.

Results

Bariatric surgery was associated with higher, but insignificantly so, health care costs, primarily due to an increase in somatic inpatient services. A significant decrease in costs of drugs was seen, especially for anti-diabetic medication. Bariatric surgery had a slight positive effect on social transfer payments and no significant effect on income.

Conclusions

There are no cost savings of bariatric surgery in the short run. Further real-world evidence over a longer period of time is needed to examine whether the higher health care costs will eventually be counterbalanced, making bariatric surgery a profitable intervention in a socio-economic perspective.

     

Study protocol to a nationwide prospective cohort study on return to gainful occupation after stroke in Denmark 1996 - 2006

Background  

Successful return to work is regarded as one of the most important outcome factors for working-age post stroke patients. The present study will estimate the effect of various predictors on the odds of returning to work after stroke. Nearly twenty thousand 20-57 year-old stroke patients in Denmark who were gainfully occupied prior to the stroke will be included in the study.