Stabilization of Peptide Vesicles by Introducing Inter-Peptide Disulfide Bonds

PURPOSE: Previously, we have shown that the amphiphilic oligopeptide SA2 (Ac-Ala-Ala-Val-Val-Leu-Leu-Leu-Trp-Glu-Glu-COOH) spontaneously self-assemble into nano-sized vesicles in aqueous environment. Relative weak individual intermolecular interactions dominate such oligopeptide assemblies. In this study we aimed at improving the stability of such peptide vesicles by covalently crosslinking the oligopeptide vesicles using disulfide bonds. Two and three cysteines were introduced in the SA2 peptide sequence to allow crosslinking (Ac-Ala-Cys-Val-Cys-Leu-(Leu/Cys)-Leu-Trp-Glu-Glu-COOH). RESULTS: Upon disulfide formation the crosslinked vesicles remained stable under conditions that disrupted the non-crosslinked peptide vesicles. The stabilized vesicles were more closely examined in terms of particle size (distribution) using atomic force microscopy, cryogenic electron microscopy, as well as dynamic light scattering analysis, showing an average particle radius in number between 15 and 20 nm. Using entrapment of calcein it was shown that intermolecular crosslinking of peptides within the vesicles did not affect the permeability for calcein. CONCLUSION: Introduction of cysteines into the hydrophobic domain of the SA2 amphiphilic oligopeptides is a feasible strategy for crosslinking the peptide vesicles. Such small crosslinked oligopeptide vesicles may hold promise for drug delivery applications

Identification of Genes Directly Involved in Shell Formation and Their Functions in Pearl Oyster, Pinctada fucata

Mollusk shell formation is a fascinating aspect of biomineralization research. Shell matrix proteins play crucial roles in the control of calcium carbonate crystallization during shell formation in the pearl oyster, Pinctada fucata. Characterization of biomineralization-related genes during larval development could enhance our understanding of shell formation. Genes involved in shell biomineralization were isolated by constructing three suppression subtractive hybridization (SSH) libraries that represented genes expressed at key points during larval shell formation. A total of 2,923 ESTs from these libraries were sequenced and gave 990 unigenes. Unigenes coding for secreted proteins and proteins with tandem-arranged repeat units were screened in the three SSH libraries. A set of sequences coding for genes involved in shell formation was obtained. RT-PCR and in situ hybridization assays were carried out on five genes to investigate their spatial expression in several tissues, especially the mantle tissue. They all showed a different expression pattern from known biomineralization-related genes. Inhibition of the five genes by RNA interference resulted in different defects of the nacreous layer, indicating that they all were involved in aragonite crystallization. Intriguingly, one gene (UD_Cluster94.seq.Singlet1) was restricted to the ‘aragonitic line’. The current data has yielded for the first time, to our knowledge, a suite of biomineralization-related genes active during the developmental stages of P.fucata, five of which were responsible for nacreous layer formation. This provides a useful starting point for isolating new genes involved in shell formation. The effects of genes on the formation of the ‘aragonitic line’, and other areas of the nacreous layer, suggests a different control mechanism for aragonite crystallization initiation from that of mature aragonite growth

The importance of multidisciplinary teamwork and team climate for relational coordination among teams delivering care to older patients

Aim To identify predictors of relational coordination among professionals delivering care to older patients. Background Relational coordination is known to enhance quality of care in hospitals. The underlying mechanisms, however, remain poorly understood. Design This cross-sectional study was part of a larger evaluation study examining the opportunity to prevent loss of function in older patients due to hospitalization in the Netherlands. Methods This study was performed in spring 2010 among team members delivering care to older hospitalized patients (192 respondents; 44% response rate) in one hospital. Relational coordination was measured by the Relational Coordination survey; team climate by the Team Climate Inventory and questions were asked about participation in multidisciplinary team meetings and disciplines represented in these meetings. To account for the hierarchical structure, a multilevel analysis was performed. Results Correlation analysis revealed a positive relationship among being female, being a nurse and relational coordination; medical specialists showed a negative relationship. The number of disciplines represented during multidisciplinary team meetings and team climate were positively related with relational coordination. The multilevel analysis showed a positive relationship between the number of disciplines represented during multidisciplinary team meetings and team climate with relational coordination. Conclusions The enhancement of team climate and attendance of diverse professionals during multidisciplinary team meetings are expected to improve relational coordination. Furthermore, this study underscores the importance of enhancing relational coordination between medical specialists and other professionals

The importance of relational coordination for integrated care delivery to older patients in the hospital

AimThis study investigated relational coordination among professionals providing healthcare to hospitalized older patients and assessed its impact on integrated care delivery. BackgroundPrevious studies have shown that relational coordination is positively associated with the delivery of acute, emergency and trauma care. The effect of relational coordination in integrated care delivery to hospitalized older patients remains unknown. MethodsThis cross-sectional study was part of an examination of integrated care delivery to hospitalized older patients. Data were collected using questionnaires distributed to hospital professionals (192 respondents; 44% response rate). ResultsAfter controlling for demographic variables, regression analyses showed that relational coordination was positively related to integrated care delivery (=0.20; P0.05). Relational coordination was lower among professionals in the same discipline, and higher between nurses and others than between medical specialists and others. Relational coordination and integrated care delivery were significantly higher in geriatrics than in other units (both P0.001). ConclusionsThe enhancement of relational coordination among healthcare professionals is positively associated with integrated care delivery to older patients. Implications for nursing managementRelational coordination should be improved between medical specialists and others and higher levels of relational coordination and integrated care delivery should be achieved in all hospital units

Chronically ill patients’ self-management abilities to maintain overall well-being: what is needed to take the next step in the primary care setting?

BACKGROUND: Although widespread problems in patient–professional interaction and insufficient support of patients’ self-management abilities have been recognized, research investigating the relationships among care quality, productive interaction, and self-management abilities to maintain overall well-being is lacking. Furthermore, studies have revealed differences in these characteristics among certain groups (e.g., less-educated and older patients). This longitudinal study thus aimed to identify relationships among background characteristics, quality of care, productivity of patient–professional interaction, and self-management abilities to maintain overall well-being in chronically ill patients participating in 18 Dutch disease management programs. METHODS: This longitudinal study included patients participating in 18 Dutch disease management programs. Surveys were administered in 2011 (T1; n = 2191 (out of 4693), 47 % response rate) and 2012 (T2: n = 1722 (out of 4350), 40 % response rate). A total of 1279 patients completed questionnaires at both timepoints (T1 and T2) (27 % response rate). Self-management abilities to maintain well-being were measured using the short (18-item) version of the Self-Management Ability Scale (SMAS-S), patients’ perceptions of the productivity of interactions with health care professionals were assessed with the relational coordination instrument and the short (11-item) version of the Patient Assessment of Chronic Illness Care (PACIC-S) was used to assess patients’ perceptions of the quality of chronic care delivery. RESULTS: Perceived and objective quality of care and the productivity of patient–professional interaction were found to be related to patients’ self-management abilities to maintain overall well-being. These abilities were related negatively to and significantly predicted by low educational level, single status, and older age, despite the mediating role of productive interaction in their relationship with patients’ perceptions of care quality. CONCLUSIONS: These findings suggest that patient–professional interaction is not yet sufficiently productive to successfully protect against the deterioration of self-management abilities in some groups of chronically ill patients, although such interaction and high-quality care are important factors in such protection. Improvement of the quality of chronic care delivery should thus always be accompanied by investment in high-quality communication and patient–professional relationships. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12875-015-0340-8) contains supplementary material, which is available to authorized users