Factors predicting 6-month retention among people with opioid use disorders accessing outpatient methadone maintenance therapy in Tshwane, South Africa

Background. In South Africa (SA), increasing illicit opioid use and associated health challenges can be managed with opioid substitution therapy (OST), such as methadone, if the recommended dose and duration of use are prescribed. The Community Oriented Substance Use Programme (COSUP) provides free methadone to patients with opioid use disorder in Tshwane, SA, on need-based criteria.Objectives. To determine selected sociodemographic and substance use treatment factors associated with retention for at least 6 months among participants receiving methadone as part of OST in COSUP.Methods. This was a retrospective cohort study using secondary data of patients treated with methadone at 8 COSUP sites. The factors associated with at least 6 months’ retention for 575 participants from December 2016 to September 2018 were analysed.Results. There were 91.3% males, 86.4% South Africans and 85.9% black Africans, with a median age of 30 years. At baseline, the majority were injecting heroin (55.5%) and were provided with free methadone (59.3%). The median dose of methadone at 6 months or on leaving the programme was 20 mg; 38.4% of participants were retained for at least 6 months. Of those not retained, the median duration on methadone was 56 days, whereas for those retained for at least 6 months, the median number of days on methadone were 254. After adjusting for sex and age, participants receiving methadone doses <50 mg had lower odds of being retained (0 - 20 mg: adjusted odds ratio (aOR) 0.25; p=0.002; 95% confidence interval (CI) 0.10 - 0.61; >20 - 40 mg: aOR 0.20; p<0.001; 95% CI 0.08 - 0.49) than those administered ≥50 mg. Participants who received free methadone had 3.75 the odds of being retained than those buying it themselves (p<0.001; 95% CI 2.47 - 5.70). Participants treated in the inner city had 5.19 the odds of being retained than those in a suburban setting (p<0.001; 95% CI 2.99 - 9.03). Compared with black African participants, white participants had 3.39 the odds of being retained (p=0.001; 95% CI 1.64 - 7.00). Injecting heroin users had 0.63 the odds of being retained (p=0.032; 95% CI 0.41 - 0.96).Conclusions. To maximise retention on OST, methadone should be free, with maintenance doses >50 mg. Reasons for lower retention among participants from periurban settings, those who inject and those from previously disadvantaged racial groups need to be explored, and findings used to inform programming

Complementarity and Scientific Rationality

Bohr's interpretation of quantum mechanics has been criticized as incoherent and opportunistic, and based on doubtful philosophical premises. If so Bohr's influence, in the pre-war period of 1927-1939, is the harder to explain, and the acceptance of his approach to quantum mechanics over de Broglie's had no reasonable foundation. But Bohr's interpretation changed little from the time of its first appearance, and stood independent of any philosophical presuppositions. The principle of complementarity is itself best read as a conjecture of unusually wide scope, on the nature and future course of explanations in the sciences (and not only the physical sciences). If it must be judged a failure today, it is not because of any internal inconsistency.Comment: 29 page

AMCIS 2022 Awards Luncheon

This is a video recording and PDF document with the AMCIS 2022 Awards Ceremony

Primary skeletal muscle cells cultured on gelatin bead microcarriers develop structural and biochemical features characteristic of adult skeletal muscle

A primary skeletal muscle cell culture, in which myoblasts derived from newborn rabbit hindlimb muscles grow on gelatin bead microcarriers in suspension and differentiate into myotubes, has been established previously. In the course of differentiation and beginning spontaneous contractions, these multinucleated myotubes do not detach from their support. Here, we describe the development of the primary myotubes with respect to their ultrastructural differentiation. Scanning electron microscopy reveals that myotubes not only grow around the surface of one carrier bead but also attach themselves to neighbouring carriers, forming bridges between carriers. Transmission electron microscopy demonstrates highly ordered myofibrils, T-tubules and sarcoplasmic reticulum. The functionality of the contractile apparatus is evidenced by contractile activity that occurs spontaneously or can be elicited by electrostimulation. Creatine kinase activity increases steadily until day 20 of culture. Regarding the expression of isoforms of myosin heavy chains (MHC), we could demonstrate that from day 16 on, no non-adult MHC isoform mRNAs are present. Instead, on day 28 the myotubes express predominantly adult fast MHCIId/x mRNA and protein. This MHC pattern resembles that of fast muscles of adult rabbits. In contrast, primary myotubes grown on matrigel-covered culture dishes express substantial amounts of non-adult MHC protein even on day 21. To conclude, primary myotubes grown on microcarriers in their later stages exhibit many features of adult skeletal muscle and characteristics of fast type II fibers. Thus, the culture represents an excellent model of adult fast skeletal muscle, for example when investigating molecular mechanisms of fast-to-slow fiber type transformatio

Online assessment of cognitive functioning across the adult lifespan using the eCOGTEL:A reliable alternative to laboratory testing

As the population ages, risks for cognitive decline threaten independence and quality of life of older adults. Classically, psychological assessment tools that evaluate cognitive functioning are administered in face-to-face laboratory sessions, which are time- and resource-consuming. The present study set out to examine whether the eCOGTEL—an online adaptation of the Cognitive Telephone Screening Instrument (COGTEL; Kliegel et al. in J Psychol 141(2):147–170, 2007)—represents a reliable measure of cognitive performance in adulthood. Therefore, an age-stratified adult lifespan sample of 253 participants (aged 19–86 years) completed a face-to-face assessment in the laboratory and a self-administered online version, at their homes. A second, independent sample of 176 younger adults (aged 19–30 years) performed a test–retest assessment of the eCOGTEL. Results showed strong correlations between overall cognitive scores assessed online and in the laboratory, as well as a high test–retest reliability. Further, comparable data distributions between both assessment modes underline the feasibility of the eCOGTEL across the adult lifespan and particularly in older age. Our findings thereby indicate that the eCOGTEL can reliably measure cognitive performance across the lifespan at reduced costs, which may help detecting individuals at risk of developing age-related cognitive decline. Due to these strengths, the eCOGTEL represents a valuable contemporary approach for the resource-efficient online assessment of cognition, which may benefit a broad array of fundamental and applied research fields, such as clinical and organizational psychology. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10433-021-00667-x

Controlled assembly of SNAP-PNA-fluorophore systems on DNA templates to produce fluorescence resonance energy transfer

The SNAP protein is a widely used self-labeling tag that can be used for tracking protein localization and trafficking in living systems. A model system providing controlled alignment of SNAP-tag units can provide a new way to study clustering of fusion proteins. In this work, fluorescent SNAP-PNA conjugates were controllably assembled on DNA frameworks forming dimers, trimers, and tetramers. Modification of peptide nucleic acid (PNA) with the O6-benzyl guanine (BG) group allowed the generation of site-selective covalent links between PNA and the SNAP protein. The modified BG-PNAs were labeled with fluorescent Atto dyes and subsequently chemo-selectively conjugated to SNAP protein. Efficient assembly into dimer and oligomer forms was verified via size exclusion chromatography (SEC), electrophoresis (SDS-PAGE), and fluorescence spectroscopy. DNA directed assembly of homo- and hetero-dimers of SNAP-PNA constructs induced homo- and hetero-FRET, respectively. Longer DNA scaffolds controllably aligned similar fluorescent SNAP-PNA constructs into higher oligomers exhibiting homo-FRET. The combined SEC and homo-FRET studies indicated the 1:1 and saturated assemblies of SNAP-PNA-fluorophore:DNA formed preferentially in this system. This suggested a kinetic/stoichiometric model of assembly rather than binomially distributed products. These BG-PNA-fluorophore building blocks allow facile introduction of fluorophores and/or assembly directing moieties onto any protein containing SNAP. Template directed assembly of PNA modified SNAP proteins may be used to investigate clustering behavior both with and without fluorescent labels which may find use in the study of assembly processes in cells

Epistemic and Ontic Quantum Realities

Quantum theory has provoked intense discussions about its interpretation since its pioneer days. One of the few scientists who have been continuously engaged in this development from both physical and philosophical perspectives is Carl Friedrich von Weizsaecker. The questions he posed were and are inspiring for many, including the authors of this contribution. Weizsaecker developed Bohr's view of quantum theory as a theory of knowledge. We show that such an epistemic perspective can be consistently complemented by Einstein's ontically oriented position

Isosbestic points in the spectral function of correlated electrons

We investigate the properties of the spectral function A(omega,U) of correlated electrons within the Hubbard model and dynamical mean-field theory. Curves of A(omega,U) vs. omega for different values of the interaction U are found to intersect near the band-edges of the non-interacting system. For a wide range of U the crossing points are located within a sharply confined region. The precise location of these 'isosbestic points' depends on details of the non-interacting band structure. Isosbestic points of dynamic quantities therefore provide valuable insights into microscopic energy scales of correlated systems.Comment: 16 pages, 5 figure