CDR3 Variants of the TXB2 Shuttle with Increased TfR1 Association Rate and Enhanced Brain Penetration.

Since the delivery of biologic drugs to the brain is greatly hampered by the existence of the blood-brain barrier (BBB), brain shuttles are being developed to enhance therapeutic efficacy. As we have previously shown, efficient and selective brain delivery was achieved with TXB2, a cross-species reactive, anti-TfR1 VNAR antibody. To further explore the limits of brain penetration, we conducted restricted randomization of the CDR3 loop, followed by phage display to identify improved TXB2 variants. The variants were screened for brain penetration in mice using a 25 nmol/kg (1.875 mg/kg) dose and a single 18 h timepoint. A higher kinetic association rate to TfR1 correlated with improved brain penetration in vivo. The most potent variant, TXB4, showed a 3.6-fold improvement over TXB2, which had on average 14-fold higher brain levels when compared to an isotype control. Like TXB2, TXB4 retained brain specificity with parenchymal penetration and no accumulation in other organs. When fused with a neurotensin (NT) payload, it led to a rapid drop in body temperature upon transport across the BBB. We also showed that fusion of TXB4 to four therapeutic antibodies (anti-CD20, anti-EGFRvIII, anti-PD-L1 and anti-BACE1) improved their brain exposure between 14- to 30-fold. In summary, we enhanced the potency of parental TXB2 brain shuttle and gained a critical mechanistic understanding of brain delivery mediated by the VNAR anti-TfR1 antibody.

Blood-brain barrier transport using a high affinity, brain-selective VNAR antibody targeting transferrin receptor 1.

Transfer across the blood-brain barrier (BBB) remains a significant hurdle for the development of biopharmaceuticals with therapeutic effects within the central nervous system. We established a functional selection method to identify high affinity single domain antibodies to the transferrin receptor 1 (TfR1) with efficient biotherapeutic delivery across the BBB. A synthetic phage display library based on the variable domain of new antigen receptor (VNAR) was used for in vitro selection against recombinant human TfR1 ectodomain (rh-TfR1-ECD) followed by in vivo selection in mouse for brain parenchyma penetrating antibodies. TXB2 VNAR was identified as a high affinity, species cross-reactive VNAR antibody against TfR1-ECD that does not compete with transferrin or ferritin for receptor binding. IV dosing of TXB2 when fused to human Fc domain (TXB2-hFc) at 25 nmol/kg (1.875 mg/kg) in mice resulted in rapid binding to brain capillaries with subsequent transport into the brain parenchyma and specific uptake into TfR1-positive neurons. Likewise, IV dosing of TXB2-hFc fused with neurotensin (TXB2-hFc-NT) at 25 nmol/kg resulted in a rapid and reversible pharmacological response as measured by body temperature reduction. TXB2-hFc did not elicit any acute adverse reactions, bind, or deplete circulating reticulocytes or reduce BBB-expressed endogenous TfR1 in mice. There was no evidence of target-mediated clearance or accumulation in peripheral organs except lung. In conclusion, TXB2 is a high affinity, species cross-reactive, and brain-selective VNAR antibody to TfR1 that rapidly crosses the BBB and exhibits a favorable pharmacokinetic and safety profile and can be readily adapted to carry a wide variety of biotherapeutics from blood to brain.

Inner histopathologic changes and disproportionate zone volumes in foetal growth plates following gestational hypoglycaemia in rats.

Maternal hypoglycaemia throughout gestation until gestation day (GD)20 delays foetal growth and skeletal development. While partially prevented by return to normoglycaemia after completed organogenesis (GD17), underlying mechanisms are not fully understood. Here, we investigated the pathogenesis of these changes and significance of maternal hypoglycaemia extending beyond organogenesis in non-diabetic rats. Pregnant rats received insulin-infusion until GD20 or GD17, with sacrifice on GD20. Hypoglycaemia throughout gestation increased maternal corticosterone levels, which correlated with foetal levels. Growth plates displayed central histopathologic changes comprising disrupted cellular organisation, hypertrophic chondrocytes, and decreased cellular density; expression of pro-angiogenic factors, HIF-1α and VEGF-A increased in surrounding areas. Disproportionately decreased growth plate zone volumes and lower expression of the structural protein MATN-3 were seen, while bone ossification parameters were normal. Ending maternal/foetal hypoglycaemia on GD17 reduced incidence and severity of histopathologic changes and with normal growth plate volume. Compromised foetal skeletal development following maternal hypoglycaemia throughout gestation is hypothesised to result from corticosterone-induced hypoxia in growth plates, where hypoxia disrupts chondrocyte maturation and growth plate structure and volume, decreasing long bone growth. Maternal/foetal hypoglycaemia lasting only until GD17 attenuated these changes, suggesting a pivotal role of glucose in growth plate development.

Accelerometer-Measured Physical Activity at Work and Need for Recovery: A Compositional Analysis of Cross-sectional Data.

OBJECTIVES: Previous research has shown strong associations between occupational physical activity (OPA) and need for recovery (NFR). However this research has only utilized self-reported measures of OPA which may be biased. Thus, there is a need for investigating if the previously documented association between self-reported OPA and NFR can be found when using technical measures of OPA. There is also the need to investigate whether older workers are particularly susceptible to increased NFR, since age-related declines in physical capacity mean that it is likely these workers will have a higher NFR for a given physical activity. The aim of this study was to investigate the association between technically measured OPA and NFR, and whether this relationship is modified by age. METHODS: This study utilized data from the Danish Physical Activity Cohort with Objective Measurements cohort-comprising Danish workers (n = 840) from the cleaning, manufacturing, and transportation sectors. OPA was measured by accelerometers attached to the thigh and upper back for at least one work day and classified into four physical behaviour categories (sedentary, standing, light, or moderate/vigorous). NFR was measured using a shortened version of the Danish NFR scale. Analysis was conducted using linear regression and isotemporal substitution analyses for compositional data. RESULTS: The overall association between OPA and NFR was statistically significant in the unadjusted model (P < 0.001), but not when adjusted for age, sex, occupation, and shift work (P = 0.166). Isotemporal substitution showed small but significant reductions in NFR when increasing sedentary time relative to other behaviours (adjusted: ΔNFR = -0.010 [-0.019; -0.001]). There were no significant interactions between age and OPA (P = 0.409). CONCLUSIONS: This study found significant associations between OPA and NFR, but the effect sizes were small. Reallocating 30 min to sedentary behaviours from other behaviours was associated with a reduced NFR, but the effect size may not be practically relevant. Moreover, no clear modifying effects of age were identified.

What Facilitates "Patient Empowerment" in Cancer Patients During Follow-Up: A Qualitative Systematic Review of the Literature.

Empowerment is a concept of growing importance in cancer care, but little is known about cancer patients' experiences of empowerment during follow-up. To explore this area, a qualitative systematic literature review was conducted in PubMed, CINAHL, and PsycINFO. A total of 2,292 papers were identified and 38 articles selected and included in the review. The thematic synthesis of the papers resulted in seven analytical themes being identified: empowerment as an ongoing process, knowledge is power, having an active role, communication and interaction between patients and health care professionals, support from being in a group, religion and spirituality, and gender. Very few articles explicitly explored the empowerment of cancer patients during follow-up, and the review identified a lack of attention to patients' own understandings of empowerment, a lack of specific focus on empowerment during follow-up, and insufficient attention to collective empowerment, as well as ethnic, social, and gender differences.

Danish translation of a physical function item bank from the Patient-Reported Outcome Measurement Information System (PROMIS).

BACKGROUND: The Patient-Reported Outcome Measurement Information System (PROMIS) is an assessment system that aims to provide more valid, reliable, responsive, and precise patient-reported outcome (PRO) measures than has been previously available. This paper documents the translation of the Physical Function item bank into Danish. METHODS: We followed the PROMIS standard procedure, including: 1) two independent translations, 2) back translation, 3) independent reviews of translation quality, and 4) cognitive interviews with a representative sample of the adult population from the municipality of Copenhagen. After each phase, the new information was reviewed and the Danish version of the PROMIS Physical Function items was revised, if warranted. RESULTS: Relatively few problems were related to translation in itself and such problems could be fixed by changes in item wordings to fit the Danish context. Cognitive testing revealed problem of a general issue: annoyance in case of mismatch between respondents' functional level and question difficulty, problems imagining performance on activities that the respondents did not usually do, and uncertainty whether mobility aids (e.g., canes and walkers) should be considered when performing an activity. Solutions to the more general issues would require revisions to the original items. CONCLUSIONS: The standard translation methodology was successful in eliminating problems in translation, and pointed to problems of a general issue in some of the original questions, producing translated Danish versions of the PROMIS Physical Functioning items. Translation and validation studies provide a valuable source when revising and improving PROs in a clinical setting or for research. The present paper exemplifies this with experiences from Denmark. The study describes how the use of PROs when measuring physical functioning in a Danish context can be improved-hence improving the items used for research, future trials and in clinical settings.