Access to Difficult-to-reach Population Subgroups: A Family Midwife Based Home Visiting Service for Implementing Nutrition-related Preventive Activities - A Mixed Methods Explorative Study.

Health and social inequality are tightly linked and still pose an important public health problem. However, vulnerable and disadvantaged populations are difficult to reach for health-related interventions. Given the long-lasting effects of an adverse, particular nutrition-related, intrauterine and neonatal environment on health development (perinatal programming), an early and easy access is essential for sustainable interventions. The goal of this explorative study was therefore to elucidate whether an existing access of family midwives (FMs) to families in need of support could be an option to implement effective public health and nutrition interventions. To that end three research objectives were formulated: (1) to determine whether a discernible impact of home visits by FMs can be described; (2) to identify subgroups among these families in need of more specific interventions; (3) to determine how relevant nutrition-related topics are for both FMs and the supported families. For addressing these objectives a mixed methods design was used: Routine documentation data from 295 families visited by a family midwife (FM) were analyzed (secondary analysis), and structured expert interviews with FMs were conducted and analyzed. Study reporting followed the STROBE (STrengthening the Reporting of OBservational studies in Epidemiology) statement. Based on the FMs reports, a significant improvement (p < 0.001) regarding psycho-social variables could be determined after the home visits. Single mothers, however, seemed to benefit less from the FMs service compared to their counterparts (p = 0.015). Nutritional counseling was demanded by 89% of the families during the home visits. In addition, nutrition-related topics were reported in the interviews to be of high interest to both families and the FMs. Based on the obtained results it is concluded that FMs home visits offer a promising access to vulnerable and disadvantaged families for implementing nutrition-related preventive activities.

A new fluorescence resonance energy transfer pair and its application to oligonucleotide labeling and fluorescence resonance energy transfer hybridization studies.

We describe two new fluorescence resonance energy transfer (FRET) compatible labels, their covalent linkage to oligonucleotides, and their use as donor and acceptor, respectively, in FRET hybridization studies. The dyes belong to the cyanine dyes, and water solubility is imparted by a phosphonate which represents a new solubilizing group in DNA labels. They were linked to amino-modified synthetic oligonucleotides via oxysuccinimide (OSI) esters. The studies performed include binding assays, determinations of molecular distances, homogeneous competitive assays, and limits of detection, which are in the order of 5 pmol/L for a 15-mer.

Set of fluorochromophores in the wavelength range from 450 to 700 nm and suitable for labeling proteins and amino-modified DNA.

We describe the synthesis, purification, and spectral properties of new dyes and reactive labels. They absorb in the visible range between 450 and 700 nm and display analytically useful fluorescence. They were made amino-reactive by esterification with N-hydroxysuccinimide (NHS). The resulting oxysuccinimide (OSI) esters were covalently linked to the amino groups of human serum albumin (HSA) or certain DNA oligomers. Except for dyes 9 and 13, they contain one reactive group only in order to avoid cross linking of biomolecules. Labeling of amino-modified biomolecules was performed by standard protocols, and the labeled proteins and oligonucleotides were separated from the unreacted dye by gel chromatography using Sephadex G25 as the stationary phase in the case of proteins, and reversed-phase HPLC in the case of DNA oligomers. The dyes also have been used as donor-acceptor pairs in fluorescence energy transfer systems and in energy transfer cascades.

Time-resolved luminescence energy transfer immunobinding study using a ruthenium-ligand complex as a donor label.

A novel immunosystem is described that exploits the effect of luminescence energy transfer from a luminescently labeled antigen to a fluorescent antibody. A luminescent ruthenium-ligand complex (D-455) with absorption/emission maxima at 456/639 nm, respectively, was employed as the donor label, and a squaraine-type cyanine label (636/655 nm), as the fluorescent acceptor label. Specifically, the system human serum albumin (HSA)/anti-HSA was studied. HSA was labeled with the donor dye D-455, and anti-HSA was labeled with the acceptor dye A-631. On formation of the antigen-antibody complex, energy transfer occurs. The radiationless energy transfer affects both the decay time of D-455 and the intensities of the emissions of both D-455 and A-631. The decay time of around 500 ns of D-455 allows frequency-domain measurements in the low kilohertz range and therefore can be based on the use of conventional optoelectronics. This also suggests gated measurements to be performed. The major difference from existing HSA immunosystems is the use of a slow decaying ruthenium-ligand complex as the donor and of a long-wave emitting cyanine acceptor dye having a high quantum yield and a decay kinetics that is governed by the rate of energy transfer from the slow decaying donor.