The Controllability Beliefs Scale used with carers of people with intellectual disabilities: psychometric properties

Background Beliefs about the controllability of behaviour have been consistently shown to be important in understanding the responses of carers to the challenging behaviour of people with intellectual disabilities (IDs). This paper reports the reliability and validity of the Controllability Beliefs Scale (CBS), a 15‐item measure of beliefs regarding the controllability of challenging behaviour when used with carers of people with IDs. Methods Two hundred and sixty‐four carers of people with IDs completed the CBS, 74 people also completed the Modified Attributional Style Questionnaire and the Self‐Injury Behavioural Understanding Questionnaire scale to determine concurrent and convergent validity and 34 people completed the scale twice within a 2‐ to 4‐week period to determine test–retest reliability. Results The scale has a two‐factor structure and has adequate internal reliable. The scale is significantly correlated with the controllability, internality and stability items from the Modified Attributional Style Questionnaire, showed expected associations with behavioural and internal emotional understanding items from the Self‐Injury Behavioural Understanding Questionnaire. The scale has good test–retest reliability. Conclusions The data support use of the CBS in clinical practice and research to assess carers' beliefs regarding challenging behaviour of people with IDs.     

Factors determining early pregnancy loss in singleton and multiple implantations

BACKGROUND: The incidence of first trimester pregnancy loss is much lower in IVF twin pregnancies than in IVF singleton pregnancies. The objective of this study was to determine which embryonic and maternal factors contribute to this finding. METHODS: Retrospective data analysis of the outcome of 1593 pregnancies after day 3 double-embryo transfer (DET) after IVF or ICSI treatment. RESULTS: Of 1148 single implantations at 6 weeks, 936 (81.5%) were ongoing pregnancies. Of 445 multiple implantations at 6 weeks, 354 (79.6%) were ongoing multiple pregnancies, 80 (17.9%) were ongoing singleton pregnancies and 11 (2.5%) ended in a spontaneous abortion. Total pregnancy loss was 18.5 and 2.5% (P < 0.001) in singleton and twin gestations, respectively. Loss per gestational sac was 18.5 and 11.46% (P < 0.001), respectively. Determinants contributing to the continuation of gestation beyond 6 weeks were young maternal age, possibility to cryopreserve embryos and short GnRH agonist flare-up stimulation protocol. Whereas factors promoting multiple implantation at 6 weeks of gestation were young maternal age, high cumulative embryo score (CES), male infertility, long stimulation protocol and thick endometrium. CONCLUSIONS: Although multiple implantation at 6 weeks is predominantly determined by (morphological) embryo quality, the continuation of pregnancy beyond 6 weeks becomes more dependent on the combination of genetic and developmental potential of the embryo(s) and an optimal uterine milieu.     

Separation of adeno-associated virus type 2 empty particles from genome containing vectors by anion-exchange column chromatography

Adeno-associated virus (AAV) empty capsids typically co-purify with genome containing AAV2 vectors purified by column chromatography. This study describes a method to remove empty capsids from genome containing vector particles by anion exchange chromatography. The separation is based on the slightly less anionic character of empty particles compared to vectors. Detailed methods to achieve AAV2 vector purification and particle separation using cation exchange resin POROS 50HS followed by anion exchange resin Q-Sepharose^xl are described. Chromatographic separation of AAV2 particles was achieved using gradients based on sodium acetate and ammonium acetate, and was optimal at pH 8.5. Efficient removal of particle surface nucleic acid impurities was found to be important to achieve good particle separation. In a large scale experiment performed using partially purified vector containing a mixture of 1.56 × 10¹⁴ vg and 2.52 × 10¹⁵ empty capsids as a starting material, the optimized anion exchange chromatography method resulted in a vector peak of 1.15 × 10¹⁴ vg containing 0.25 × 10¹⁴ empty capsids, corresponding to 74% vector yield and 86-fold reduction in empty capsids in the vector product.     

High throughput ranking of recombinant avian scFv antibody fragments from crude lysates using the Biacore A100

Advances in molecular evolution strategies have made it possible to identify antibodies with exquisite specificities and also to fine-tune their biophysical properties for practically any specified application. Depending on the desired function, antibody/antigen interactions can be long-lived or short-lived and, therefore, particular attention is needed when seeking to identify antibodies with specific reaction-rate and affinity properties. Surface plasmon resonance (SPR) biosensors routinely generate sensitive and reliable kinetic data from antibody/antigen interactions for both therapeutic and diagnostic applications. However, many kinetic-based screening assays require rigorous sample preparation and purification prior to analysis. To ameliorate this problem, we developed a rapid and reliable assay for characterising recombinant scFv antibody fragments, directly from crude bacterial lysates. Ninety-six scFv antibodies derived from chickens immunised with C-reactive protein (CRP) were selected by phage display and evaluated using the Biacore A100 protein interaction array system. Antibodies were captured from crude bacterial extracts on the sensor chip surface and ranked based on the percentage of the complex left (% left) after dissociation in buffer. Kinetic rate constants (k(a) and k(d)) and affinity (K(D)) data were obtained for six clones that bound monomeric CRP across a broad affinity range (2.54 x 10(-8) to 3.53 x 10(-10) M). Using this assay format the A100 biosensor yielded high quality kinetic data, permitting the screening of nearly 400 antibody clones per day.     

Recurrence of Upper Extremity Deep Vein Thrombosis Secondary to COVID-19

Infection with SARS-CoV-2 leading to COVID-19 induces hyperinflammatory and hypercoagulable states, resulting in arterial and venous thromboembolic events. Deep vein thrombosis (DVT) has been well reported in COVID-19 patients. While most DVTs occur in a lower extremity, involvement of the upper extremity is uncommon. In this report, we describe the first reported patient with an upper extremity DVT recurrence secondary to COVID-19 infection.