Comparative studies of the preparation of immunoliposomes with the use of two bifunctional coupling agents and investigation of in vitro immunoliposome-target cell binding by cytofluorometry and electron microscopy

The two coupling agents SPDP (N-succinimidyl-3-(2-pyridyldithio)propionate) and SATA (N-succinimidyl-S-acetylthioacetate) were compared in their efficiency and feasibility to couple monoclonal antibodies (Abs) via thioether linkage to liposomes functionalized by various lipophilic maleimide compounds like Full-size image methyl ester (MP-PL), N-(3-maleimidopropionyl)phosphatidylethanolamide (MP-PE), Full-size image methyl ester (EMC-PL), and N-(6-maleimidocaproyl)phosphatidylethanolamine (EMC-PE). The composition of the liposomes was soy phosphatidylcholine (SPC), cholesterol, maleimide compounds and -tocopherol (1:0.2:0.02:0.01, mol parts), plus N4-oleylcytosine arabinoside (NOAC) as cytostatic prodrug (0.2 mol parts) and a new, lipophilic and highly fluorescent dye N,N′-bis(1-hexylheptyl)-3,4:9,10-perylenebis(dicarboximide) (BHPD, 0.006 mol parts). From the maleimide derivatives MP-PL was the most effective in terms of preservation of the coupling activity in dependence of liposome storage. The coupling of the monoclonal A B8-24.3 (mouse IgG2b, MHC class I, anti H-2kb) and IB16-6 (rat IgG2a, anti B16 mouse melanoma) to the drug carrying liposomes was more effective and easier to accomplish with SATA as compared to SPDP. Coupling rates of 60–65% were obtained with SATA at molar ratios of 12 SATA:1 Ab:40 maleimide spacer groups on the surface of one liposome. The highest coupling rates with SPDP were obtained at the ratio of 24 SPDP:1 Ab:40 liposomal maleimide groups, with an Ab binding efficiency of only 20–25%. The optimal in vitro binding conditions to specific target cells (EL4 for B8-24.3-liposomes and B16-F10 for IB16-6-liposomes) were determined by cytofluorometric measurement of the liposomal BHPD fluorescence with SATA linked Abs. Optimal immunoliposome binding to specific epitopes on the target cells was achieved with 1–2 Ab molecules coupled to one liposome, with immunoliposome concentrations of 20–130 nM and with a small incubation volume of 0.3–0.4 ml. The specificity of the binding of B8-24.3-liposomes to EL4 target cells was visualized by scanning electron microscopy. Antibody mediated endocytic uptake of immunoliposomes could be demonstrated by transmission electron microscopy

Governing human resources for health in a global context - the case of the Republic of Malawi

Bredehorst M. Governing human resources for health in a global context - the case of the Republic of Malawi. Bielefeld: Universität Bielefeld; 2015.Background: At the beginning of the new millennium, Malawi receives international attention for its Human Resources for Health (HRH) crisis, together with 57 other developing countries identified in the World Health Report 2006. Poverty-related diseases including HIV/AIDS have added to the workload and perpetuated attrition from the Malawian health workforce. After president H.K. Banda’s 30 years of autocratic rule ended in 1994, the health labour market has also become increasingly international. Opportunities have opened up to find work and better payment either abroad or with private and non-governmental organisations. By 2009, a large-scale intervention of international donors is underway to re-strengthen HRH as a basis for delivering an essential health package to the Malawian population and reducing poverty. Starting from the idea of sustainable development that has evolved since the Rio Declaration 1994, the underlying assumption of this study is that qualified health work can be seen as a common-pool resource system. Commons theory suggests that self-organization and rule-setting by relevant actors could help to balance the appropriation and (re)production of a resource in a circumscribed system. This study investigates how the cooperation of Malawian and international employers can be regulated to achieve a well-performing and sustainable health workforce. Methodology: Malawi has been selected as the research site for a country case study based on qualitative and quantitative, primary and secondary data. A field research phase of six months in 2009 has been used for collecting text documents and statistics, and for conducting 25 expert interviews. Secondary data has been analysed to reconstruct the historically grown structures and conditions of HRH and international cooperation. Interview data has first been subjected to thematic analysis, with themes deducted from the UNDP capacity development framework. Relevant findings feed into an institutional analysis (Oakerson 2003; Ostrom 2005), looking at strategies, norms and rules applied to HRH in Malawi. The focus is on the district health system as an action arena, but other linked arenas are also considered. Results: The HRH system in Malawi shows warning signs of depletion, as reproduction through training cannot meet the domestic demand and compensate for attrition. Expectations to revert this trend are focused on the government and the Christian Health Association of Malawi (CHAM) as those who have historically been in charge of securing the availability of different cadres of health workers. At the same time, the appropriators of HRH (organisations acting as employers or contractors) have multiplied and diversified. This group is characterized by striking asymmetries regarding their dependence on HRH, their financial and technological endowments and their autonomy in decision making. International actors’ entry to and exit from the system is weakly regulated. As for the level of the health district, three basic strategies of international aid agencies emerge: (1) direct implementation of health-related activities, (2) implementation through the District Health Office as a governmental structure, (3) implementation through other Malawian organisations or consultants. Although HRH is a cross-cutting issue in health service provision, the interview statements hardly convey explicit rules concerning the inter-organisational cooperation on HRH appropriation and/or reproduction. Concepts of staff supervision and professional development continue to be geared towards control and hierarchy. Even when it comes to the zonal or national level, the special features of HRH - such as individual decision-making and mobility of health workers, their socio-cultural embeddedness and their capacity to organize – only begin to be addressed. Discussion: Human resources largely meet the economic attributes of a common-pool resource, namely subtractability, indivisibility and limited excludability. As such, it appears promising to apply governance concepts to HRH which have originally been devised for sustaining natural resources. However, compared against the sustainability criteria named in commons theory, the findings for Malawi (together with the political developments since 2009) do not give rise to optimism. New forms of governance in this field are likely to be inhibited by the degree of deterioration of the HRH system and the existing incentive structures, the difficulties of monitoring, a lack of trust and reciprocity among the different actors and low levels of autonomy from external forces. At the same time, the study has revealed some potential points of intervention if collective rule setting at the level of the health district is to be enabled, involving local and global, governmental and non-governmental actors. Political decentralisation appears to have reached a new phase in Malawi, with the local elections finally conducted in 2014. The district assemblies and the Zonal Health Support Offices may take responsibilities with regard to monitoring and conflict resolution in the HRH system. The increasing frequency of strikes among health workers also underlines the need for clearer regulative frameworks at the constitutional level in Malawi, providing for new actor constellations and a new understanding of HRH

Immobilized stem–loop structured probes as conformational switches for enzymatic detection of microbial 16S rRNA

We have designed and evaluated novel DNA stem–loop structured probes for enzymatic detection of nucleic acid targets. These probes constitute a novel class of conformational switches for enzymatic activity, which in the absence of a target sterically shield an affinity label and upon hybridization of the target to the recognition sequence that forms the loop of the probe restore accessibility of the label for the binding of a reporter enzyme. Analysis of probe characteristics revealed stem stability as the most important parameter governing detection functionality, while other factors such as the length of linker molecules attaching the label to the stem–loop structure and the nature of the solid support proved to be less critical. Apparently, the bulky nature of the reporter enzyme facilitates shielding of the label in the absence of the target, thereby conferring considerable structural tolerance to the conformational switch system. The stem–loop structured probes allow sensitive detection of unlabeled nucleic acid targets. Employing a microtiter assay format, 4 ng of bacterial 16S ribosomal RNA corresponding to 8 fmol could be detected, which can be compared favorably with current immobilized molecular beacon concepts based on fluorescence detection

Correlates of depressive symptoms among Latino and Non-Latino White adolescents: Findings from the 2003 California Health Interview Survey

BACKGROUND: The prevalence of depression is increasing not only among adults, but also among adolescents. Several risk factors for depression in youth have been identified, including female gender, increasing age, lower socio-economic status, and Latino ethnic background. The literature is divided regarding the role of acculturation as risk factor among Latino youth. We analyzed the correlates of depressive symptoms among Latino and Non-Latino White adolescents residing in California with a special focus on acculturation. METHODS: We performed an analysis of the adolescent sample of the 2003 California Health Interview Survey, which included 3,196 telephone-interviews with Latino and Non-Latino White adolescents between the ages of 12 and 17. Depressive symptomatology was measured with a reduced version of the Center for Epidemiologic Studies Depression Scale. Acculturation was measured by a score based on language in which the interview was conducted, language(s) spoken at home, place of birth, number of years lived in the United States, and citizenship status of the adolescent and both of his/her parents, using canonical principal component analysis. Other variables used in the analysis were: support provided by adults at school and at home, age of the adolescent, gender, socio-economic status, and household type (two parent or one parent household). RESULTS: Unadjusted analysis suggested that the risk of depressive symptoms was twice as high among Latinos as compared to Non-Latino Whites (10.5% versus 5.5 %, p < 0.001). The risk was slightly higher in the low acculturation group than in the high acculturation group (13.1% versus 9.7%, p = 0.12). Similarly, low acculturation was associated with an increased risk of depressive symptoms in multivariate analysis within the Latino subsample (OR 1.54, CI 0.97–2.44, p = 0.07). Latino ethnicity emerged as risk factor for depressive symptoms among the strata with higher income and high support at home and at school. In the disadvantaged subgroups (higher poverty, low support at home and at school) Non-Latino Whites and Latinos had a similar risk of depressive symptoms. CONCLUSION: Our findings suggest that the differences in depressive symptoms between Non-Latino Whites and Latino adolescents disappear at least in some strata after adjusting for socio-demographic and social support variables

Recombinant phospholipase A1 (Ves v 1) from yellow jacket venom for improved diagnosis of hymenoptera venom hypersensitivity

<p>Abstract</p> <p>Background</p> <p>Hymenoptera venoms are known to cause life-threatening IgE-mediated anaphylactic reactions in allergic individuals. Proper diagnosis of hymenoptera venom allergy using venom extracts is severely affected by molecular cross-reactivities. Although non-glycosylated marker allergens would facilitate the identification of the culprit venom, the major allergen phospholipase A1 (Ves v 1) from yellow jacket venom (YJV) remained unavailable so far.</p> <p>Methods</p> <p>Expression of Ves v 1 as wild type and enzymatically inactivated mutant and Ves v 5 in insect cells yielded soluble proteins that were purified via affinity chromatography. Functionality of the recombinant allergens was assessed by enzymatic and biophysical analyses as well as basophil activation tests. Diagnostic relevance was addressed by ELISA-based analyses of sera of YJV-sensitized patients.</p> <p>Results</p> <p>Both major allergens Ves v 1 and Ves v 5 could be produced in insect cells in secreted soluble form. The recombinant proteins exhibited their particular biochemical and functional characteristics and were capable for activation of human basophils. Assessment of IgE reactivity of sera of YJV-sensitized and double-sensitized patients emphasised the relevance of Ves v 1 in hymenoptera venom allergy. In contrast to the use of singular molecules the combined use of both molecules enabled a reliable assignment of sensitisation to YJV for more than 90% of double-sensitised patients.</p> <p>Conclusions</p> <p>The recombinant availability of Ves v 1 from yellow jacket venom will contribute to a more detailed understanding of the molecular and allergological mechanisms of insect venoms and may provide a valuable tool for diagnostic and therapeutic approaches in hymenoptera venom allergy.</p

Challenges of audit of care on clinical quality indicators for hypertension and type 2 diabetes across four European countries

BACKGROUND: The purpose of the study was to measure clinical quality by doing an audit of clinical records and to compare the performance based on clinical quality indicators (CQI) for hypertension and type 2 diabetes across seven European countries: Estonia, Finland, Germany, Hungary, Italy, Lithuania and Spain. METHODS: Two common chronic conditions in primary care (PC), hypertension and type 2 diabetes, were selected for audit. The assessment of CQI started with a literature review of different databases: Organization for Economic Co-operation and Development, World Health Organization, European Commission European Community Health Indicators, US National Library of Medicine. Data were collected from clinical records. RESULTS: Although it was agreed to obtain the clinical indicators in a similar way from each country, the specific data collection process in every country varied greatly, due to different traditions in collecting and keeping the patients' data, as well as differences in regulation regarding access to clinical information. Also, there was a huge variability across countries in the level of compliance with the indicators. CONCLUSIONS: Measurement of clinical performance in PC by audit is methodologically challenging: different databases provide different information, indicators of quality of care have insufficient scientific proof and there are country-specific regulations. There are large differences not only in quality of health care across Europe but also in how it is measured.EU primecare project was funded under the European Commission’s 7th Framework Programme (grant no. 241595).S

Recommendations for the primary prevention of atherosclerotic cardiovascular disease in primary care: a systematic guideline review

IntroductionThis study systematically reviews and synthesizes recommendations from national and international clinical practice guidelines (CPGs) regarding the primary prevention of atherosclerotic cardiovascular disease (ASCVD) in adults in primary care settings.MethodsCPGs were retrieved from MEDLINE, Trip, guideline repositories, and websites of guidelines-producing societies. Two reviewers independently screened the guidelines for eligibility, assessed their quality, and extracted study characteristics and relevant recommendations for further consistency analysis. Recommendations, with their strength and evidence level, were thematically coded and clustered around clinical questions using ATLAS.ti.ResultsWe included 26 CPGs from which we extracted 581 recommendations on risk assessment, non-pharmacological, and pharmacological interventions. Twenty-one guidelines (81%) were rated as having “very good” methodological quality. We categorized the recommendations into 124 clusters. Forty-four clusters (35%) included consistent recommendations, but only four of them (3%) included highly consistent recommendations. These clusters emphasized avoiding routine prescriptions of nicotinic acid, aspirin, and fibrates for primary ASCVD prevention alone, and recommending 20 mg/day of atorvastatin for high-risk ASCVD patients. The recommendations also highlighted the importance of adhering to a Mediterranean-type diet, patient-centered counseling, and standardized risk assessment for patients over the age of 40.DiscussionThis review underscores the heterogeneity in primary ASCVD prevention recommendations and the importance of personalized strategies for at-risk individuals.Systematic review registrationPROSPERO, CRD42023394605, available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023394605