Novel Assay of Metformin Levels in Patients With Type 2 Diabetes and Varying Levels of Renal Function: Clinical recommendations

AbstractObjective: To study trough levels of metformin in serum and its intra individual variation in patients using a newly developed assay. Research Design and Methods: Trough serum levels of metformin was measured once using Liquid Chromatography Tandem Mass Spectrometry (LcMSMS) in 137 type 2 diabetes patients with varying renal function (99 men) and followed repeatedly during two months in 20 patients (16 men) with estimated GFR (eGFR) below 60 ml/min/1.73 m(2) body surface. Results: Patients with eGFR >60, 30-60, and <30 ml/min/1.73 m(2) had a median trough metformin concentration of 4.5 mumol/l (range 0.1-20.7, n=107), 7.71 mumol/l (0.12-15.15, n=21), and 8.88 mumol/l (5.99-18.60, n=9), respectively. The median intraindividual overall coefficient of variation (CV) was 29.4 % (range 9,8-74,2). Conclusions: Determination of serum metformin with the LCMSMS technique is useful in patients on metformin treatment. Few patients had values over 20 mumol/L. Metformin measurement is less suitable for dose titration

Identification of storage conditions stabilizing extracellular vesicles pre

Extracellular vesicles (EVs) play a key role in many physiological and pathophysiological processes and hold great potential for therapeutic and diagnostic use. Despite significant advances within the last decade, the key issue of EV storage stability remains unresolved and under investigated. Here, we aimed to identify storage conditions stabilizing EVs and comprehensively compared the impact of various storage buffer formulations at different temperatures on EVs derived from different cellular sources for up to 2 years. EV features including concentration, diameter, surface protein profile and nucleic acid contents were assessed by complementary methods, and engineered EVs containing fluorophores or functionalized surface proteins were utilized to compare cellular uptake and ligand binding. We show that storing EVs in PBS over time leads to drastically reduced recovery particularly for pure EV samples at all temperatures tested, starting already within days. We further report that using PBS as diluent was found to result in severely reduced EV recovery rates already within minutes. Several of the tested new buffer conditions largely prevented the observed effects, the lead candidate being PBS supplemented with human albumin and trehalose (PBS-HAT). We report that PBS-HAT buffer facilitates clearly improved short-term and long-term EV preservation for samples stored at -80°C, stability throughout several freeze-thaw cycles, and drastically improved EV recovery when using a diluent for EV samples for downstream applications

Towards a new understanding of HIV-related stigma in the era of efficient treatment- A qualitative reconceptualization of existing theory

Aim To further develop Earnshaw and Chaudoir's HIV stigma framework by describing the experiences of HIV‐related stigma among people living with viral suppression in a context where HIV is well controlled and to investigate how these experiences correspond to the stigma mechanisms of the framework. Design Qualitative study using interviews and a framework approach to analysis. Methods People living with virally suppressed HIV in Sweden were recruited through an outpatient clinic and interviewed about their experiences of social aspects of living with HIV. The interviews were audio recorded, transcribed and analysed using a framework approach. Results Fifteen participants (eight women and seven men, aged 30–64 years) were interviewed from March to September 2017. They described stigma around HIV as a barrier in many situations. Anticipated and enacted stigma were found to be more complex than is described in the existing literature. Being labelled as a person with HIV was found to be an important and persistent part of the stigma experience. Disclosure was found to be context‐related and a result of a process of negotiating and weighing the relevance of disclosing HIV, perceiving HIV as a private matter and feeling a responsibility to disclose one's HIV status to others. An important reason for nondisclosure was to avoid being labelled with HIV, which would then become their most defining feature. Conclusions The HIV stigma framework could benefit from revision for people living with virally suppressed HIV. Implications The present findings, which indicate the role of health professionals in relation to disclosure and labelling, may guide nurses and other healthcare personnel in providing counselling and support for people who live with virally suppressed HIV and experience stigma

Barriers to HIV testing as reported by individuals newly diagnosed with HIV infection in Sweden

Despite the availability of free and anonymous HIV testing almost 60% of Swedish patients are diagnosed late. Identifying predictors of different types of barriers could inform policy makers and health care of interventions to increase testing where needed. This cross-sectional study aimed to describe and analyze barriers to HIV testing as reported by Swedish patients newly diagnosed with HIV infection. N = 285 patients completed the 18-item Barriers to HIV Testing Scale - Karolinska Version. Descriptive analysis and logistic regressions were performed to assess the prevalence of barriers and to identify predictors for the different investigated barriers. Barriers to testing were reported by 60%. Approximately 67% of patients originating from Sweden, 50% from Sub-Saharan Africa and 75% from Eastern European/East Asian countries reported barriers. Patients who were younger and patients who self-initiated HIV testing, had greater odds of reporting a barrier than older individuals and those who were offered a test through screening or by a healthcare professional. To counteract barriers that still exist on an individual level, healthcare-initiated HIV testing could be offered more broadly and information about risks for transmission and effectiveness of HIV treatment still needs to be disseminated among both people born in Sweden and different migrant groups

Engineered extracellular vesicle decoy receptor-mediated modulation of the IL6 trans-signalling pathway in muscle

The cytokine interleukin 6 (IL6) is a key mediator of inflammation that contributes to skeletal muscle pathophysiology. IL6 activates target cells by two main mechanisms, the classical and trans-signalling pathways. While classical signalling is associated with the anti-inflammatory activities of the cytokine, the IL6 trans-signalling pathway mediates chronic inflammation and is therefore a target for therapeutic intervention. Extracellular vesicles (EVs) are natural, lipid-bound nanoparticles, with potential as targeted delivery vehicles for therapeutic macromolecules. Here, we engineered EVs to express IL6 signal transducer (IL6ST) decoy receptors to selectively inhibit the IL6 trans-signalling pathway. The potency of the IL6ST decoy receptor EVs was optimized by inclusion of a GCN4 dimerization domain and a peptide sequence derived from syntenin-1 which targets the decoy receptor to EVs. The resulting engineered EVs were able to efficiently inhibit activation of the IL6 trans-signalling pathway in reporter cells, while having no effect on the IL6 classical signalling. IL6ST decoy receptor EVs, were also capable of blocking the IL6 trans-signalling pathway in C2C12 myoblasts and myotubes, thereby inhibiting the phosphorylation of STAT3 and partially reversing the anti-differentiation effects observed when treating cells with IL6/IL6R complexes. Treatment of a Duchenne muscular dystrophy mouse model with IL6ST decoy receptor EVs resulted in a reduction in STAT3 phosphorylation in the quadriceps and gastrocnemius muscles of these mice, thereby demonstrating in vivo activity of the decoy receptor EVs as a potential therapy. Taken together, this study reveals the IL6 trans-signalling pathway as a promising therapeutic target in DMD, and demonstrates the therapeutic potential of IL6ST decoy receptor EVs

Systematic characterization of extracellular vesicle sorting domains and quantification at the single molecule – single vesicle level by fluorescence correlation spectroscopy and single particle imaging

Extracellular vesicles (EV) convey biological information by transmitting macromolecules between cells and tissues and are of great promise as pharmaceutical nanocarriers, and as therapeutic per se. Strategies for customizing the EV surface and cargo are being developed to enable their tracking, visualization, loading with pharmaceutical agents and decoration of the surface with tissue targeting ligands. While much progress has been made in the engineering of EVs, an exhaustive comparative analysis of the most commonly exploited EV-associated proteins, as well as a quantification at the molecular level are lacking. Here, we selected 12 EV-related proteins based on MS-proteomics data for comparative quantification of their EV engineering potential. All proteins were expressed with fluorescent protein (FP) tags in EV-producing cells; both parent cells as well as the recovered vesicles were characterized biochemically and biophysically. Using Fluorescence Correlation Spectroscopy (FCS) we quantified the number of FP-tagged molecules per vesicle. We observed different loading efficiencies and specificities for the different proteins into EVs. For the candidates showing the highest loading efficiency in terms of engineering, the molecular levels in the vesicles did not exceed ca 40–60 fluorescent proteins per vesicle upon transient overexpression in the cells. Some of the GFP-tagged EV reporters showed quenched fluorescence and were either non-vesicular, despite co-purification with EVs, or comprised a significant fraction of truncated GFP. The co-expression of each target protein with CD63 was further quantified by widefield and confocal imaging of single vesicles after double transfection of parent cells. In summary, we provide a quantitative comparison for the most commonly used sorting proteins for bioengineering of EVs and introduce a set of biophysical techniques for straightforward quantitative and qualitative characterization of fluorescent EVs to link single vesicle analysis with single molecule quantification

The Relationship Between Stigma and Health-Related Quality of Life in People Living with HIV Who Have Full Access to Antiretroviral Treatment: An Assessment of Earnshaw and Chaudoir's HIV Stigma Framework Using Empirical Data.

The aim was to empirically test the tenets of Earnshaw and Chaudoir's HIV stigma framework and its potential covariates for persons living with HIV in Sweden. Partial least squares structural equation modelling was used on survey data from 173 persons living with HIV in Sweden. Experiencing stigma was reported to a higher extent by younger persons and by women who had migrated to Sweden. As expected, anticipated stigma was related to lower Physical functioning, and internalized stigma to lower Emotional wellbeing. In contrast to that hypothesized by the HIV stigma framework, enacted stigma was not related to Physical functioning and no relationships were found between HIV-related stigma and antiretroviral adherence. These results indicate that the HIV stigma framework may need to be revised for contexts where a very high proportion of persons living with HIV are diagnosed and under efficient treatment

Reproductive health and lifestyle factors associated with health-related quality of life among perinatally HIV-infected adolescents in Uganda

Background With increased survival of perinatally HIV - infected adolescents due to antiretroviral therapy (ART), the focus of HIV care has shifted to health-related quality of life (HRQoL) as a measure of disease progression, effects of ART co-morbidity and prognosis. We assessed factors associated with better HRQoL in perinatally HIV -infected adolescents in Uganda by determining the associations between sexual and reproductive health (SRH) or lifestyle experiences on HRQoL. Methods In a cross-sectional study, data on SRH, lifestyle experiences, socio demographic factors, communication with parents on sexuality and satisfaction of SRH services in ART clinics were collected from 614 HIV perinatally infected adolescents aged 10–19 using an interviewer-administered survey questionnaire. HRQoL data were collected using the Medical Outcomes Study HIV Health Survey instrument (MOS-HIV). Factors associated with better HRQoL were analysed using multiple logistic regression. Results The mean age was 16.2 ± 2.1 years, 362 (58.8 %) were females and 210 (34.2 %) were sexually active. Adolescents on ART were twice likely to present with better physical health (AOR = 2.07, 95 % CI: 1.24–3.46) and four times more likely to present with better mental health (AOR = 3.9, 95 % CI: 2.22–6.92) than those who were not on ART. There were no statistically significant associations between SRH (ever had sex, ever been pregnant, condom use, contraceptive use) or life style factors and physical health or mental health. Those with secondary or tertiary education were more likely to present with a better mental health (AOR = 5.3, 95 % CI: 1.86–15.41) compared those who had attained primary or no education. Participants who desired to have a child in future more likely (AOR 1.7, 95 % CI: 1.05–3.00) to present with a better mental health. Lack of communication with guardians on sexuality (AOR = 0.6, 95 % CI: 0.40–0.89), or dissatisfaction with SRH services (AOR 0.34, 95 % CI: 0.18–0.62) were associated with poorer mental health. Conclusion Among perinatally HIV-infected adolescents in Uganda, being on ART was associated with better physical and mental health while lack of communication with guardians on sexuality or dissatisfaction with SRH services was associated with poor mental health. Adolescents with pregnancy intentions were more likely to have a better mental health

RNA delivery by extracellular vesicles in mammalian cells and its applications.

The term 'extracellular vesicles' refers to a heterogeneous population of vesicular bodies of cellular origin that derive either from the endosomal compartment (exosomes) or as a result of shedding from the plasma membrane (microvesicles, oncosomes and apoptotic bodies). Extracellular vesicles carry a variety of cargo, including RNAs, proteins, lipids and DNA, which can be taken up by other cells, both in the direct vicinity of the source cell and at distant sites in the body via biofluids, and elicit a variety of phenotypic responses. Owing to their unique biology and roles in cell-cell communication, extracellular vesicles have attracted strong interest, which is further enhanced by their potential clinical utility. Because extracellular vesicles derive their cargo from the contents of the cells that produce them, they are attractive sources of biomarkers for a variety of diseases. Furthermore, studies demonstrating phenotypic effects of specific extracellular vesicle-associated cargo on target cells have stoked interest in extracellular vesicles as therapeutic vehicles. There is particularly strong evidence that the RNA cargo of extracellular vesicles can alter recipient cell gene expression and function. During the past decade, extracellular vesicles and their RNA cargo have become better defined, but many aspects of extracellular vesicle biology remain to be elucidated. These include selective cargo loading resulting in substantial differences between the composition of extracellular vesicles and source cells; heterogeneity in extracellular vesicle size and composition; and undefined mechanisms for the uptake of extracellular vesicles into recipient cells and the fates of their cargo. Further progress in unravelling the basic mechanisms of extracellular vesicle biogenesis, transport, and cargo delivery and function is needed for successful clinical implementation. This Review focuses on the current state of knowledge pertaining to packaging, transport and function of RNAs in extracellular vesicles and outlines the progress made thus far towards their clinical applications