As the US health care system strives to function efficiently, encourage preventive and primary care, improve quality, and overcome nonfinancial barriers to care, the potential exists for community health workers to further these goals. Community health workers can increase access to care and facilitate appropriate use of health resources by providing outreach and cultural linkages between communities and delivery systems; reduce costs by providing health education, screening, detection, and basic emergency care; and improve quality by contributing to patient-provider communication, continuity of care, and consumer protection. Information sharing, program support, program evaluation, and continuing education are needed to expand the use of community health workers and better integrate them into the health care delivery system.

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BackgroundUganda’s national community health worker program involves volunteer Village Health Teams (VHTs) delivering basic health services and education. Evidence demonstrates their positive impact on health outcomes, particularly for Ugandans who would otherwise lack access to health services. Despite their impact, VHTs are not optimally supported and attrition is a growing problem. In this study, we examined the support needs and existing challenges of VHTs in two Ugandan districts and evaluated specific factors associated with long-term retention. We report on findings from a standardized survey of VHTs and exploratory interviews with key stakeholders and draw conclusions that inform efforts to strengthen and sustain community health care delivery in Uganda.MethodsA mixed-methods approach was employed through a survey of 134 individual VHT members and semi-structured interviews with six key stakeholders. Descriptive and bivariate regression analysis of quantitative survey data was performed along with thematic analysis of qualitative data from surveys and interviews. In the regression analysis, the dependent variable is 10-year anticipated longevity among VHTs, which asked respondents if they anticipate continuing to volunteer as VHTs for at least 10 more years if their current situation remains unchanged.ResultsVHTs desire additional support primarily in the forms of money (e.g. transportation allowance) and material supplies (e.g. rubber boots). VHTs commonly report difficult working conditions and describe a lack of respect from their communities and other health workers. If their current situation remains unchanged, 57% of VHTs anticipate remaining in their posts for at least 10 years. Anticipated 10-year longevity was positively associated with stronger partnerships with local health center staff and greater ease in home visiting.ConclusionsSupporting and retaining Uganda’s VHTs would be enhanced by building stronger partnerships between VHTs and other health workers and regularly providing supplies and transportation allowances. Pursuing such measures would likely improve equity in access to healthcare for all Ugandans.Electronic supplementary materialThe online version of this article (doi:10.1186/s12939-017-0619-6) contains supplementary material, which is available to authorized users.

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A new type of synthetic membrane transporter is described and shown to operate in vesicles by a relay mechanism. The transporter structure is a phosphatidylcholine derivative with a urea group appended to the end of its sn-2 acyl chain. The urea can bind a chloride ion at the membrane surface via hydrogen bonds and then relay it through the bilayer interior to an acceptor molecule located in the opposite membrane leaflet. Three phosphatidylcholine derivatives were studied and transport rates increased with transporter affinity for chloride. The results of various controls studies are consistent with an anion countertransport process using a relay mechanism and a kinetically active aggregate of two or four transporter molecules. Transport is inhibited if the transporter resides in only one leaflet of the membrane, if the bilayer is too thick, and if the counteranion is sulfate dianion. The expected favorable formulation properties of these amphiphilic compounds should facilitate efforts to transform them into tools for biomedical research and perhaps as therapeutic agents.

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The copper catalyzed azide alkyne cycloaddition is employed to modify phosphatidylcholine precursors with sn-2 acyl chains containing terminal alkyne or azide groups. Although the reactions are conducted as biphasic dispersions, the yields are essentially quantitative. Bolaamphiphiles are formed by simply clicking together two phosphatidylcholine alkyne precursors to a central bisazide scaffold. The chemistry introduces polar 1,4-triazole units into the lipophilic region of the bilayer membrane, and the bolaamphiphiles do not form stable vesicles.Bolaamphiphiles are amphiphilic compounds, containing two hydrophilic head-groups connected by a hydrophobic spacer. 1 One of the best-known families of naturally-occurring bolaamphiphiles are the archae lipids. A typical structure, shown in Figure 1, has a hydrocarbon chain that is connected by ether linkages to two zwitterionic phosphocholine head-groups. 2 These membrane-spanning, polar lipids rigidify the bilayer membrane and allow the thermophilic archae to endure temperatures in excess of 80° C and low pH. 3 Since it is difficult to produce these natural products in large amounts, several groups have investigated simplified synthetic mimics and found that they also have membrane stabilizing properties. Synthetic bolaamphiphiles with membrane-spanning macrocycles, 4 or unbranched hydrocarbon chains, 5 linking two phosphoglycerol head-groups are known to form membranes with increased melting temperatures, decreased permeation of ions and small polar molecules, and increased ordering of the membrane components. 7 Typically, these molecular designs incoporate polar functionality into the central region of a spacer that is otherwise hydrophobic. Whatever the specific functional objective, the bolaamphiphile synthesis is always a major technical challenge, especially if the molecule contains sensitive functionality such as that found in the head-groups of the common, naturally occurring, phospholipids.Our recent interest in the effects of bolaamphiphiles on membrane structure and function 8 has lead us to develop a method of producing them in large amounts from readily available starting materials. An obvious family of potential building blocks, that have pre-installed polar headgroups, are the lysophospholipids, with lysophophosphatidylcholine as the archetype example. Acylation of the sn-2 hydroxyl in lysophophosphatidylcholine with a suitably functionalized acyl chain gives a phosphatidylcholine precursor that can be dimerized to produce a bolaamphiphile. The chemistry to produce symmetric couplings includes olefin metathesis9 and Glaser oxidation;4a whereas, asymmetric cross couplings have been achieved using the Wittig reaction, nucleophilic substitution, conjugate addition, and the Diels-Alder reaction. 5c ,6 The latter reactions have also been conducted in preformed liposomal membranes. All of these synthetic procedures have drawbacks; either the yields are not extremely high or the chemistry is not compatible with all types of biomolecular functional gr...

Molecular probes with zinc(II)-(2,2'-dipicolylamine) coordination complexes associate with oxyanions in aqueous solution and target biomembranes that contain anionic phospholipids. This study examines a new series of coordination complexes with 2,6-bis(zinc(II)-dipicolylamine) phenoxide as the molecular recognition unit. Two lipophilic analogues are observed to partition into the membranes of zwitterionic and anionic vesicles and induce the transport of phospholipids and hydrophilic anions (carboxyfluorescein). These lipophilic zinc complexes are moderately toxic to mammalian cells. A more hydrophilic analogue does not exhibit mammalian cell toxicity (LD 50 >50 µg/mL), but it is highly active against the Gram-positive bacteria Staphylococcus aureus (MIC of 1 µg/mL). Furthermore, it is active against clinically important S. aureus strains that are resistant to various antibiotics including vancomycin and oxacillin. The antibiotic action is attributed to its ability to depolarize the bacterial cell membrane. The intense bacterial staining exhibited by a fluorescent conjugate suggests that this family of zinc coordination complexes can be used as molecular probes for the detection and imaging of bacteria.