WHO RHN Network

The WHO European Office for Investment for Health and Development (Venice Office) works in the thematic areas of health equity, social and economic determinants of health, and investment for health in the context of the 2030 Agenda for Sustainable Development and the European Programme of Work. Within the WHO Venice Office, the the Regions for Health Network (RHN) works to place health and well-being high on the key political agendas, and advocates the needs of local and subnational authorities at the regional and international levels. RHN has been launched in 1993 to help regions to accelerate the delivery of improved population health, and currently has 34 members. It has developed over the decades into a forum that creates synergies between regions and stakeholders in the field of health (mutual learning); strengthens cooperation/collaboration between regional and local actors and international health institutions; increases understanding of the functioning of regional and local health systems; promotes the exchange of experience, and mutual learning. RHN positions itself at the forefront of innovative approaches and aims at becoming a cutting-edge network ready to capture and disseminate effective approaches, policies and strategies that improve population health at the regional level of governance. In past years, RHN has spearheaded collaborative efforts amongst cross-border regions, on different topics, and with technical guidance from WHO. These efforts have led to joint initiatives, publications, study trips, project collaboration and periodic and structured exchanges of experiences.

In Vitro Calcification of Bioprosthetic Heart Valves: Test Fluid Validation on Prosthetic Material Samples

Calcification is a major failure mode of bioprosthetic heart valves. So far, cost and time saving in vitro analyses of calcification potentials are unreliable, mostly due to superficial or spontaneous precipitation of the applied fluids. In this study, we developed a near-physiological non-spontaneously precipitating fluid for an accelerated in vitro calcification assessment, and validated it by analyzing the calcification potential of two prosthetic materials within two reference-tests. The first test focused on the comparison of four calcification fluids under dynamic contact with n=12 commercial bovine pericardium patches. The second one focused on the validation of the most appropriate fluid by analyzing the calcification potential of pericardium vs. polyurethane. The patches were mounted in separate test compartments and treated simultaneously with the respective fluids at an accelerated test frequency. Calcification propensity and progression were detected macroscopically and microscopically. Structural analyses of all deposits indicated hydroxyapatite by X-ray powder diffraction, which is also most commonly observed in vivo. Histological examination by von Kossa staining showed matrix internal and superficial calcifications, depending on the fluid composition. The present study reveals promising results towards the development of a meaningful, cost and time saving in vitro analysis of the calcification potential of bioprosthetic heart valves.

Biomimetic multilayer coatings deliver gentamicin and reduce implant-related osteomyelitis in rats

Implant-related infections like periprosthetic joint infections (PJI) are still a challenging issue in orthopedic surgery. In this study, we present a prophylactic anti-infective approach based on a local delivery of the antibiotic gentamicin. The local delivery is achieved via a nanoscale polyelectrolyte multilayer (PEM) coating that leaves the bulk material properties of the implant unaffected while tuning the surface properties. The main components of the coating, i.e. polypeptides and sulfated glycosaminoglycans (sGAG) render this coating both biomimetic (matrix mimetic) and biodegradable. We show how adaptions in the conditions of the multilayer assembly process and the antibiotic loading process affect the amount of delivered gentamicin. The highest concentration of gentamicin could be loaded into films composed of polypeptide poly-glutamic acid when the pH of the loading solution was acidic. The concentration of gentamicin on the surface could be tailored with the number of deposited PEM layers. The resulting coatings reveal a bacteriotoxic effect on Staphylococcus cells but show no signs of cytotoxic effects on MC3T3-E1 osteoblasts. Moreover, when multilayer-coated titanium rods were implanted into contaminated medullae of rat tibiae, a reduction in the development of implant-related osteomyelitis was observed. This reduction was more pronounced for the multifunctional, matrix-mimetic heparin-based coatings that only deliver lower amounts of gentamicin.

In Vitro Calcification of Bioprosthetic Heart Valves: Investigation of Test Fluids

Calcification is a major reason for the failure of bioprosthetic heart valves. Therefore, several attempts towards an accelerated in vitro model were undertaken in order to provide a cost- and time-saving method for the analysis of calcification processes. Due to the problem of superficial or spontaneous precipitation, which occurred in the fluids applied, we focused our study on the development of a near-physiological calcification fluid. The desired fluid should not precipitate spontaneously and should neither promote nor inhibit calcification. Eleven different fluid compositions were tested without contact to potentially calcifying materials. Crucial factors regarding the fluid properties were the ionic product, the ionic strength, and the degree of supersaturation concerning dicalciumphosphate-dihydrate, octacalciumphosphate, and hydroxyapatite. The fluids were kept in polyethylene bottles and exposed to a slight vibration within a durability tester at 37 °C. The precipitation propensity was monitored optically and colorimetrically. A structural analysis of the deposits was carried out by x-ray powder diffraction and IR-spectroscopy, which showed the development of the crystal phases that are relevant in vivo. Only two of the fluids did not precipitate. Resulting from the computations of the effective fluid contents, the saturation degree concerning dicalciumphosphate-dihydrate seems to be the key factor for spontaneous precipitation.

A simplified method for treating Graves' disease with radioactive 131I

We reviewed the medical records of 53 patients treated in 1986 for Graves' disease with moderate doses of 131I. The cumulative incidence of hypothyroidism at 3 and 12 months after therapy was 38 and 80%, respectively. The hyperthyroidism, however, was rapidly cured and only 4(7.5%) patients required a second dose of 131I. In a separate study of 21 patients with Graves' disease, we determined that the 4-hour 123I uptake measurement was as reliable as the standard 24-hour test for supporting the diagnosis of hyperthyroidism. We also demonstrated that the 4-hour uptake accurately predicted the 24-hour uptake. Based on these findings and a review of the literature, we believe that either a 4 or 24-hour 123I uptake study followed by the administration of a fixed dose of 131I (10 or 15 mCi) provides a convenient and cost-effective method for treating Graves' disease.