Autonomic Regulation of Voltage-Gated Cardiac Ion Channels

Altering voltage-gated ion channel currents, by changing channel number or voltage-dependent kinetics, regulates the propagation of action potentials along the plasma membrane of individual cells and from one cell to its neighbors. Functional increases in the number of cardiac sodium channels (Na_V1.5) at the myocardial sarcolemma are accomplished by the regulation of caveolae by β adrenergically stimulated G-proteins. We demonstrate that Na_V1.5, Ca_V1.2a, and K_V1.5 channels specifically localize to isolated caveolar membranes, and to punctate regions of the sarcolemma labeled with caveolin-3. In addition, we show that Na_V1.5, Ca_V1.2a, and K_V1.5 channel antibodies label the same subpopulation of isolated caveolae. Plasma membrane sheet assays demonstrate that Na_V1.5, Ca_V1.2a, and K_V1.5 cluster with caveolin-3. This may have interesting implications for the way in which adrenergic pathways alter the cardiac action potential morphology and the velocity of the excitatory wave.     

IgE cross-reactivity between birch pollen, mugwort pollen and celery is due to at least three distinct cross-reacting allergens: immunoblot investigation of the birch-mugwort-celery syndrome

Background Allergy to celery is often associated with sensitization to birch and/or mugwort pollen. Objective and methods In a multi-centre study, sera from 23 patients suffering from type I allergy to celery and 15 patients with positive celery RAST but wo clinical sensitization were compared. To examine whether cross-reactivity between celery and mugwort pollen iticludes cross-sensitization to birch pollen allergens, we determined cross-reacting structures in birch pollen, mugwort pollen and celery by means of immunoblotting. Inhibition studies were performed by preincubation of sera with extracts of birch pollen, mugwort pollen, and celery. Results We identified three groups of proteins—homologues of Bet v I and birch profilin (Bet v 2) as well asa group of proteins with a molecular range of 46 to 60 kD—displaying IgE-cross-reactivity, which were shared by birch pollen and celery. Two of these groups of allergens (profilin and the 46 to 60 kD proteins) were also present in mugwort pollen. In this paper we demonstrate that most cross-reacting allergens present in mugwort pollen and celery can also be detected in birch pollen extract. Conclusion Therefore we propose, from a serological point of view, to extend the mugwort-celery syndrome to the birch-mugwort-celery syndrome.     

Salivary electrolytes and digitalis

The hypothesis that an increase in salivary concentration ofcertain electrolytes (Ca x K) is a sign of digitalis intoxicationwas tested in 16 untreated health volunteers, 29 digitalisedheart failure patients and four further healthy volunteers givendigoxin. Salivary electrolyte levels were raised in only abouthalf the digitalised patients and blood levels of digoxin werenot always higher in these patients than in those with normalelectrolyte concentrations. The salivary electrolyte levelsof the healthy volunteers given digoxin remained normal. Thesefindings would seem to rule out the possibility that digitalisis responsible for the changes in salivary electrolytes observedin certain cases of heart failure. A very marked correlation(P<0.00002 by Fisher's exact probability test) was found,however, between an increase in the product of salivary calciumand potassium (Ca_sal x K_sal) and the presence of clinical signsof poorly compensated heart failure. It is suggested that thismight be a result of adrenergic stimulation, which is knownto occur in heart failure, affecting the salivary glands.     

Critical review of nutrition assessment tools to measure malnutrition in chronic kidney disease

The use of the Subjective Global Assessment (SGA) and similar clinical tools for nutrition assessment is integral in the nutritional management of chronic kidney disease (CKD) patients. The present paper is a critical review of the quality of studies introducing and validating SGA‐based tools in CKD. In the CKD literature, clinical, predictive and criterion validity were investigated by a number of studies. Common limitations identified include the use of questionable statistical methods, difference in prevalence of malnutrition based on tool or administrator (i.e. dietitan, nephrologist or nurse) and use of inadequate reference tests to establish true nutrition status. The SGA appears to have the best diagnostic evidence to adequately detect the presence of abnormal nutrition status and prognostic evidence to predict poor outcome. Modified scored versions may improve clinician’s ability to detect degree of malnutrition; however, the present review indicates more work is required. Tools based on the original SGA claiming validity in CKD and potentially other clinical areas should be approached with caution. Critical evaluation of study design, reference tests and statistical methods is recommended before implementing new tools in practice.     

Use of the Acute Care Hospital Foodservice Patient Satisfaction Questionnaire to monitor trends in patient satisfaction with foodservice at an acute care private hospital

Aim:  To demonstrate how the Acute Care Hospital Foodservice Patient Satisfaction Questionnaire can be used to monitor trends in foodservice satisfaction.
Methods:  Three one-day surveys of foodservice satisfaction were conducted in 2003–05. All adult hospital inpatients with the exception of intensive care, cardiac post-operative care, labour ward and day surgery patients were eligible. The response rate was 48% (2003), 42% (2004) and 60% (2005). This took place in an acute care 440-bed private hospital. Overall foodservice satisfaction, dimensions of foodservice satisfaction (food quality, meal service quality, staff/service issues and the physical environment) and two independent statements (temperature of the hot foods, ability to choose different sized meals); satisfaction by gender, length of stay, age, diet type and appetite for 2005. Scores were calculated for overall satisfaction, four dimensions of satisfaction and two independent statements. Chi-squared analysis was used to determine the effect of gender, age, diet type and appetite on overall satisfaction. Correlation analysis was used to assess the association between overall foodservice satisfaction and length of stay.
Results:  Ratings of overall foodservice satisfaction, four dimensions of foodservice and two independent foodservice items were high, consistent with previous findings. Of the foodservice dimensions, the staff/service issues were the most positively rated and food quality the least positively rated. Patients' expectations of the foodservice were significantly associated with overall satisfaction. Quality improvement activities focused on the lowest scoring components of the questionnaire.
Conclusion:  The Acute Care Hospital Foodservice Patient Satisfaction Questionnaire can be used to determine trends in foodservice satisfaction and identify areas to target for quality improvement initiatives.