Disopyramide: a review of its pharmacological properties and therapeutic use in treating cardiac arrhythmias.

Disopyramide is a new antiarrhythmic drug with a pharmacological profile of action similar to that of quinidine and procainamide. In a few controlled therapeutic trails and a large number of uncontrolled studies in patients with arrhythmias, often following a myocardial infarction, disopyramide has been relatively effective (more so in ventricular than in atrial arrhythmias) and usually well tolerated. In treating premature atrial and ventricular contractions, the best-studied area of its therapeutic use, disopyramide was superior to a placebo and of similar efficacy to but better tolerated than quinidine; the drop-out rate due to adverse effects of the disopyramide group (10%) being less than one-third that of the quinidine group (36%). In an open ward setting, disopyramide used prophylactically after myocardial infarction appeared to reduce both the incidence of reinfarction and the mortality rate, while in patients treated in coronary care units although the incidence of reinfarction was lower with disopyramide than with a placebo, the mortality rate was not significantly different. Further well-designed trials with adequate numbers of patients are needed before the routine use of disopyramide in infarct patients treated in either setting can be justified. Comparative studies are also required to determine if disopyramide has advantages over other antiarrhythmic agents in this area of use. Side-effects with disopyramide are usually a result of its anticholinergic activity, a dry mouth and difficulty in urination being the most common. Like other antiarrhythmic agents, disopyramide exerts a negative inotropic action on cardiac muscle, and development of acute heart failure has been reported. Development of worsening of heart block and hypotension have also occurred. Disopyramide is largely excreted unchanged and dosage should be reduced in patients with impaired renal function, in accordance with creatinine clearance values.     

Evaluating the feasibility of lantibiotics as an alternative therapy against bacterial infections in humans

Since the commercialization and ubiquitous use of antibiotics in the 20th century, there has been a steady increase in the number of reports on resistant bacteria. In recent years, this situation has become even more dramatic. The relatively slow development of new drugs, especially those with novel modes of action on target bacteria, is not paired with the rapid rate of resistance appearance. Lantibiotics form a group of antimicrobial peptides of bacterial origin with a dual mechanism of action not shared by other therapeutic compounds in use. They have a high potency to inhibit diverse (multidrug resistant) bacteria, combined with a low tendency to generate resistance. These properties make lantibiotics attractive candidates for clinical applications. This paper discusses some of the most recent results obtained in lantibiotic clinical application, paying special attention to the pharmacokinetic and pharmacodynamic properties they display. The objective of this paper is to give insight into the actual clinical applicability of lantibiotics and to point to the unexplored aspects that should be addressed in future research. The authors feel that lantibiotics could increase the number of second line antibiotics for systemic use in the future; however, further research is still needed before this is possible.     

Detection of muramyl dipeptide-sensing pathway defects in patients with Crohn's disease

BACKGROUND AND AIMS: Crohn's disease is strongly associated with double mutations in NOD2/CARD15. Three common mutations (Arg702Trp, Gly908Arg, Leu1007fs) impair innate immune responses to bacterial muramyl dipeptide. Rare NOD2 variants occur, but it is difficult to both identify them and assess their functional effect. We assessed the true frequency of defective muramyl dipeptide sensing in Crohn's disease and developed a rapid diagnostic assay. MATERIALS AND METHODS: An ex vivo assay was established and validated based on muramyl dipeptide stimulation of peripheral blood mononuclear cell cytokine production. Muramyl dipeptide-induced enhancement of interleukin (IL)-8 secretion and synergistic increase in lipopolysaccharide-induced IL-1beta secretion were studied. Assay results were compared with NOD2 genotype status (3 common mutations and rare variants) in 91 individuals including a prospective cohort of 49 patients with Crohn's disease. RESULTS: The assay was highly sensitive and specific for detection of profound defects in muramyl dipeptide sensing caused by double NOD2 mutations (IL-8 P = 0.0002; IL-1beta P = 0.0002). Disease state, active inflammation, or concurrent use of immunosuppressive medication did not influence results. Healthy NOD2 heterozygotes had modest impairment of muramyl dipeptide induced IL-8 secretion (P = 0.003). Only 1 of 7 patients with Crohn's disease with both a common mutation and a rare variant had a profound muramyl dipeptide-sensing defect. CONCLUSIONS: Profound defects in muramyl dipeptide sensing were found in 10% of patients with Crohn's disease. Defects were caused exclusively by inherited mutations in NOD2. The ex vivo assay has multiple potential applications as a clinical diagnostic tool to distinguish patients with muramyl dipeptide-sensing defects and for research investigation.     

Partner, Learn, Progress: a conceptual model for continuous clinical education

In practice disciplines, such as nursing, learning can be maximised through experience located in the clinical setting. However, placement in the clinical setting does not automatically mean that the learner's professional practice will improve. Experiences in 'real-life' settings need to be effectively facilitated to obtain the desired outcomes. This paper through the discussion of 'Partner, Learn, Progress' details a conceptual model for promoting learning in the clinical context. 'Partner' refers to the positive association between the learner and the experienced clinician that engenders trust. It occurs on a personal level in the context of a broader social and political environment. 'Learn' refers to the process whereby the experienced clinician is able to assist the learner make sense of theoretical knowledge or knowledge that has previously been 'distal' to their practice to be integrated into their immediate practice. The clinician requires to be cognisant of the learner's existing knowledge level so that the activities and accompanying discussion assist in making connections between theory and practice. Learning incorporates mutual collaboration whereby the learner is able to practise the application of knowledge in a safe context and make their own connections. The further exploration of meanings through experiences, feelings, attitudes leads the learner to 'progress': the development of knowledge. Such a conceptual model provides a framework for educators and supervisors of clinical learning to educate and learn from the next generation of nurses that will lead the nursing profession into the future.     

Students' perception of the psycho-social clinical learning environment: an evaluation of placement models

Nursing is a practice based discipline. A supportive environment has been identified as important for the transfer of learning in the clinical context. The aim of the paper was to assess undergraduate nurses' perceptions of the psychosocial characteristics of clinical learning environments within three different clinical placement models. Three hundred and eight-nine undergraduate nursing students rated their perceptions of the psycho-social learning environment using a Clinical Learning Environment Inventory. There were 16 respondents in the Preceptor model category, 269 respondents in the Facilitation model category and 114 respondents in the clinical education unit model across 25 different clinical areas in one tertiary facility. The most positive social climate was associated with the preceptor model. On all subscales the median score was rated higher than the two other models. When clinical education units were compared with the standard facilitation model the median score was rated higher in all of the subscales in the Clinical Learning Environment Inventory. These results suggest that while preceptoring is an effective clinical placement strategy that provides psycho-social support for students, clinical education units that are more sustainable through their placement of greater numbers of students, can provide greater psycho-social support for students than traditional models.     

Modulation of dendritic cell phenotype and function in an in vitro model of the intestinal epithelium

A network of dendritic cells (DC) can be detected in close proximity to the epithelial cells overlying Peyer's patches in the gut. Intestinal DC show distinct phenotypes as compared to DC from the systemic lymph nodes (relatively low MHC and costimulatory molecules and high IL-10 and TGFbeta) and may play a role in maintaining tolerance to enteric antigens. We show that a similar phenotype is induced in the presence of a polarised epithelial cell monolayer in vitro. Monocyte-derived DC were co-cultured with Caco-2 intestinal epithelial monolayers for 24 h. Co-culture resulted in DC with reduced expression of MHC class II, CD86, and CD80, and poor T cell stimulatory capacity. Cytokine profiles showed reduced levels of inflammatory cytokine production, and co-cultured DC were less sensitive to stimulation via Toll-like receptors (TLR2, 4, and 6) as a result of increased levels of autocrine TGFbeta production. However, phenotypic changes in co-cultured DC could not be blocked by removal of apoptotic cells or addition of anti-TGFbeta antibodies, suggesting that other soluble factors are involved in DC modulation. Thus, polarised epithelial cell monolayers create a 'tolerogenic' environment which modulates the activity of DC. These results highlight the regulatory importance of the epithelial microenvironment at mucosal surfaces.     

Association study of IL2/IL21 and FcgRIIa: significant association with the IL2/IL21 region in Scandinavian coeliac disease families

The first genome-wide association study performed in a UK coeliac disease (CD) case-control cohort revealed association with a linkage disequilibrium block containing the KIAA1109/Tenr/IL2/IL21 genes. Also recently, an association with a non-synonymous polymorphism in FcgammaRIIa (CD32a) was reported in CD with an unusually strong P-value. We aimed to replicate the reported associations with the single nucleotide polymorphisms rs13119723 A>G and rs6822844 G>T in the KIAA1109/Tenr/IL2/IL21 region and rs1801274 G>A in the FcgammaRIIa gene in a family sample consisting of 325 Swedish/Norwegian families using the robust transmission disequilibrium test. The family sample used in this study included 100 families with two or more children affected by CD and 225 families with one affected child. We could confirm significant association between the polymorphisms rs13119723 A>G and rs6822844 G>T located in the KIAA1109/Tenr/IL2/IL21 region and CD (P-value 0.001 and 0.002, respectively). However, we found no association with the FcgammaRIIa rs1801274 G>A polymorphism (P-value=0.3). In conclusion, our results support the KIAA1109/Tenr/IL2/IL21 region as a true CD susceptibility region.