Acceptability of a Personal Contact Intervention among People Living with Dementia: Might Baseline Contact Matter?

Our study aimed to explore how perceived baseline contact may influence acceptability of Connecting Today, a personal contact intervention, among people living with dementia. We aimed to generate hypotheses for testing in future studies. This was a sub-group analysis of pilot study data. Fifteen people living with mild to moderate dementia participated in Connecting Today. We explored how perceptions of intervention acceptability may differ in groups reporting weekly contact (n = 8) compared with groups reporting monthly/unknown (n = 7) contact at baseline. Measures of acceptability included a treatment perceptions and preferences questionnaire, and the number of and reasons for non-consent, missing data, and study withdrawal. We used descriptive statistics and content analysis. In visits one and two, a larger proportion (85.7-100%) of low baseline contact participants reported feeling better, and indicated that the visits helped them and were easy "mostly" or "a lot", compared with the high baseline contact group (37.5-62.5%). Most missing data (71%) and all study withdrawals occurred in the high baseline contact group. Scheduled in-person visits with family, friends, or a volunteer may appeal to residents in care homes who have few existing opportunities for routine, one-on-one visits with others. Hypotheses generated should be tested in future studies.

Music Connects Us: Development of a Music-Based Group Activity Intervention to Engage People Living with Dementia and Address Loneliness.

There is a need for intervention research to understand how music-based group activities foster engagement in social interactions and relationship-building among care home residents living with moderate to severe dementia. The purpose of this conceptual paper is to describe the design of 'Music Connects Us', a music-based group activity intervention. Music Connects Us primarily aims to promote social connectedness and quality of life among care home residents living with moderate to severe dementia through engagement in music-making, supporting positive social interactions to develop intimate connections with others. To develop Music Connects Us, we adapted the 'Music for Life' program offered by Wigmore Hall in the United Kingdom, applying an intervention mapping framework and principles of engaged scholarship. This paper describes in detail the Music Connects Us program, our adaptation approach, and key adaptations made, which included: framing the project to focus on the engagement of the person living with dementia to ameliorate loneliness; inclusion of student and other community-based musicians; reduced requirements for care staff participation; and the development of a detailed musician training approach to prepare musicians to deliver the program in Canada. Description of the development, features, and rationale for Music Connects Us will support its replication in future research aimed to tests its effects and its use in clinical practice.

Protein aging: truncation of aquaporin 0 in human lens regions is a continuous age-dependent process.

The human lens is ideal for the study of macromolecular aging because cells in the centre, along with their constituent proteins, are present for our entire lives. We examined the major membrane protein, aquaporin 0 (AQP0), in regions of the lens formed at different times during our lifespan, to determine if similar changes could be detected and if they were progressive. Membrane fractions from three concentric lens regions were examined by SDS-PAGE coupled with densitometry, and Western blotting, to assess the time course of truncation. The overall extent of modification was also examined by MALDI mass spectrometry of the undigested proteins. In all regions, AQP0 became progressively more truncated, specifically by the loss of a 2kDa intracellular C-terminal peptide. The proteolysis increased steadily in all regions such that half of the AQP0 in the barrier region (that part of the lens formed immediately after birth) had been cleaved by age 40-50. MALDI mass spectrometry revealed that in all regions, AQP0 not only was shortened, it also became progressively more heterogeneous with age. Since the lens interior is devoid of active enzymes, it is very likely that the cleavage of AQP0 is chemically induced. We speculate that the loss of this C-terminal peptide 'spacer' may allow occlusion of AQP0 pores on the cytoplasmic face of the fibre cell membranes. Once a significant proportion of AQP0 has been cleaved, this occlusion may contribute to the formation of the lens permeability barrier that develops at middle age.

MALDI tissue profiling of integral membrane proteins from ocular tissues.

MALDI tissue profiling and imaging have become valuable tools for rapid, direct analysis of tissues to investigate spatial distributions of proteins, potentially leading to an enhanced understanding of the molecular basis of disease. Sample preparation methods developed to date for these techniques produce protein expression profiles from predominantly hydrophilic, soluble proteins. The ability to obtain information about the spatial distribution of integral membrane proteins is critical to more fully understand their role in physiological processes, including transport, adhesion, and signaling. In this article, a sample preparation method for direct tissue profiling of integral membrane proteins is presented. Spatially resolved profiles for the abundant lens membrane proteins aquaporin 0 (AQP0) and MP20, and the retinal membrane protein opsin, were obtained using this method. MALDI tissue profiling results were validated by analysis of dissected tissue prepared by traditional membrane protein processing methods. Furthermore, direct tissue profiling of lens membrane proteins revealed age related post-translational modifications, as well as a novel modification that had not been detected using conventional tissue homogenization methods.

The outer membrane usher forms a twin-pore secretion complex.

The PapC usher is an outer membrane protein required for assembly and secretion of P pili in uropathogenic Escherichia coli. P pilus biogenesis occurs by the chaperone/usher pathway, a terminal branch of the general secretory pathway. Periplasmic chaperone-subunit complexes target to the PapC usher for fiber assembly and secretion through the usher to the cell surface. The molecular details of pilus biogenesis at the usher, and protein secretion across the outer membrane in general, are unclear. We studied the structure and oligomeric state of PapC by gel filtration, dynamic light scattering, and electron microscopy and image analysis. Two-dimensional crystals of wild-type PapC and a C-terminal deletion mutant of PapC were produced by reconstituting detergent purified usher into E.coli lipids. PapC formed a dimer both in detergent solution and in the phospholipid bilayer. Cryo-electron microscopy revealed that the usher forms a twin-pore complex. Removal of the C-terminal domain did not change the basic shape of the PapC molecule, but altered the dimeric association of the usher, suggesting that the C terminus forms part of the dimerization interface. The overall molecular size (11 nm), pore size (2 nm), and twin-pore configuration of PapC resemble that of the Tom40 complex, a mitochondrial outer membrane protein translocase.

Bartonella chomelii sp. nov., isolated from French domestic cattle (Bos taurus).

Two strains of bacteria isolated from the blood of French domestic cows were found to be similar to Bartonella species on the basis of phenotypic characteristics. Genotypic analysis based on sequence comparison of the 16S rRNA and citrate synthase (gltA) genes and on DNA-DNA hybridization showed that the two isolates represent a distinct and new species of Bartonella. Moreover, the phylogenetic analysis inferred from comparison of 16S rRNA and gltA sequences demonstrated that the new Bartonella species is related to other ruminant-derived Bartonella species. The name Bartonella chomelii is proposed for the new species. The type strain of Bartonella chomelii sp. nov. is A828T (=CIP 107869T=CCUG47497T).