Parental caregivers' perception of their transition from hospital to home in children with cerebral palsy who have undergone orthopedic surgery.

PURPOSE: Evaluate parental perception of the quality of discharge teaching, readiness for discharge, and the impact of these on post discharge coping difficulty and resource utilization in children with cerebral palsy (CP) following surgery. DESIGN AND METHODS: Prospective cohort study conducted from September 2017-March 2021 at a pediatric academic medical center. Demographics were collected pre-operatively. Parents completed the Readiness for Hospital Discharge Scale (RHDS) and Quality of Discharge Teaching Scale (QDTS) within four hours of discharge. Four weeks post-discharge, parents completed the Post-discharge Coping Difficulty Scale (PDCDS). Utilization of healthcare resources were extracted from the electronic health record for 90 days post-operatively. Associations among demographics, RHDS, QDTS, PDCDS and resource utilization were assessed using general linear models; PDCDS's open-ended questions were analyzed using directed content analysis. RESULTS: 114 parental caregivers participated. Post discharge coping was significantly associated with additional resource utilization: length of stay (p = 0.046), readmissions (p = 0.001), emergency department visits (p = 0.001), clinic calls (p = 0.001) and unplanned clinic visits (p = 0.006). PDCDS was negatively correlated with the QDTS Quality of Teaching Delivered subscale (r = -0.32; p = 0.004) and three of five RHDS subscales: 1) Child's Personal Status (r = -0.24; p = 0.02); 2) Knowledge (r = -0.30; p = 0.005); and 3) Coping Ability (r = -0.39; p < 0.001). Four themes explicated parental coping difficulties. CONCLUSION: Parents experiencing coping difficulties were more likely to have difficulty managing their child's care needs at home and required additional health care resources. PRACTICE IMPLICATIONS: Recognizing that parents' readiness for discharge may not reflect their coping abilities post-discharge requiring nurses to coordinate pre- and post-discharge education and support services.

In Vivo Imaging of the Programmed Death Ligand 1 by 18F PET.

Programmed death ligand 1 (PD-L1) is an immune regulatory ligand that binds to the T-cell immune check point programmed death 1. Tumor expression of PD-L1 is correlated with immune suppression and poor prognosis. It is also correlated with therapeutic efficacy of programmed death 1 and PD-L1 inhibitors. In vivo imaging may enable real-time follow-up of changing PD-L1 expression and heterogeneity evaluation of PD-L1 expression across tumors in the same subject. We have radiolabeled the PD-L1-binding Affibody molecule NOTA-ZPD-L1_1 with 18F and evaluated its in vitro and in vivo binding affinity, targeting, and specificity. Methods: The affinity of the PD-L1-binding Affibody ligand ZPD-L1_1 was evaluated by surface plasmon resonance. Labeling was accomplished by maleimide coupling of NOTA to a unique cysteine residue and chelation of 18F-AlF. In vivo studies were performed in PD-L1-positive, PD-L1-negative, and mixed tumor-bearing severe combined immunodeficiency mice. Tracer was injected via the tail vein, and dynamic PET scans were acquired for 90 min, followed by γ-counting biodistribution. Immunohistochemical staining with an antibody specific for anti-PD-L1 (22C3) was used to evaluate the tumor distribution of PD-L1. Immunohistochemistry results were then compared with ex vivo autoradiographic images obtained from adjacent tissue sections. Results: NOTA-ZPD-L1_1 was labeled, with a radiochemical yield of 15.1% ± 5.6%, radiochemical purity of 96.7% ± 2.0%, and specific activity of 14.6 ± 6.5 GBq/µmol. Surface plasmon resonance showed a NOTA-conjugated ligand binding affinity of 1 nM. PET imaging demonstrated rapid uptake of tracer in the PD-L1-positive tumor, whereas the PD-L1-negative control tumor showed little tracer retention. Tracer clearance from most organs and blood was quick, with biodistribution showing prominent kidney retention, low liver uptake, and a significant difference between PD-L1-positive (percentage injected dose per gram [%ID/g] = 2.56 ± 0.33) and -negative (%ID/g = 0.32 ± 0.05) tumors (P = 0.0006). Ex vivo autoradiography showed excellent spatial correlation with immunohistochemistry in mixed tumors. Conclusion: Our results show that Affibody ligands can be effective at targeting tumor PD-L1 in vivo, with good specificity and rapid clearance. Future studies will explore methods to reduce kidney activity retention and further increase tumor uptake.

Pharmacological properties of MK-3207, a potent and orally active calcitonin gene-related peptide receptor antagonist.

Calcitonin gene-related peptide (CGRP) has long been hypothesized to play a key role in migraine pathophysiology, and the advent of small-molecule antagonists has clearly demonstrated a clinical link between blocking the CGRP receptor and migraine efficacy. 2-[(8R)-8-(3,5-Difluorophenyl)-10-oxo-6,9-diazaspiro[4.5]dec-9-yl]-N-[(2R)-2'-oxo-1,1',2',3-tetrahydrospiro[indene-2,3'-pyrrolo[2,3-b]pyridin]-5-yl]acetamide (MK-3207) represents the third CGRP receptor antagonist to display clinical efficacy in migraine trials. Here, we report the pharmacological characterization of MK-3207, a potent and orally bioavailable CGRP receptor antagonist. In vitro, MK-3207 is a potent antagonist of the human and rhesus monkey CGRP receptors (K(i) = 0.024 nM). In common with other CGRP receptor antagonists, MK-3207 displays lower affinity for CGRP receptors from other species, including canine and rodent. As a consequence of species selectivity, the in vivo potency was assessed in a rhesus monkey pharmacodynamic assay measuring capsaicin-induced changes in forearm dermal blood flow via laser Doppler imaging. MK-3207 produced a concentration-dependent inhibition of dermal vasodilation, with plasma concentrations of 0.8 and 7 nM required to block 50 and 90% of the blood flow increase, respectively. The tritiated analog [3H]MK-3207 was used to study the binding characteristics on the human CGRP receptor. [3H]MK-3207 displayed reversible and saturable binding (K(D) = 0.06 nM), and the off-rate was determined to be 0.012 min(-1), with a t(1/2) value of 59 min. In vitro autoradiography studies on rhesus monkey brain slices identified the highest level of binding in the cerebellum, brainstem, and meninges. Finally, as an index of central nervous system penetrability, the in vivo cerebrospinal fluid/plasma ratio was determined to be 2 to 3% in cisterna magna-ported rhesus monkeys.

A novel radioligand for glycine transporter 1: characterization and use in autoradiographic and in vivo brain occupancy studies.

INTRODUCTION: In an effort to develop agents to test the NMDA hypofunction hypothesis of schizophrenia, benchmark compounds from a program to discover potent, selective, competitive glycine transporter 1 (GlyT1) inhibitors were radiolabeled in order to further study the detailed pharmacology of these inhibitors and the distribution of GlyT1 in brain. We here report the in vitro characterization of [35S](S)-2-amino-4-chloro-N-(1-(4-phenyl-1-(propylsulfonyl)piperidin-4-yl)ethyl)benzamide ([35S]ACPPB), a radiotracer developed from a potent and selective non-sarcosine-derived GlyT1 inhibitor, its use in autoradiographic studies to localize (S)-2-amino-6-chloro-N-(1-(4-phenyl-1-(propylsulfonyl)piperidin-4-yl)ethyl)benzamide (ACPPB) binding sites in rat and rhesus brain and for in vivo occupancy assays of competitive GlyT1 inhibitors. METHODS: Functional potencies of unlabeled compounds were characterized by [14C]glycine uptake into JAR (human placental choriocarcinoma) cells and synaptosomes. Radioligand binding studies were performed with tissue homogenates. Autoradiographic studies were performed on tissue slices. RESULTS: ACPPB is a potent (Kd=1.9 nM), selective, GlyT1 inhibitor that, when radiolabeled with [35S], is a well-behaved radioligand with low nondisplaceable binding. Autoradiographic studies of rat and rhesus brain slices with this ligand showed that specific binding sites were plentiful and nonhomogeneously distributed, with high levels of binding in the brainstem, cerebellar white matter, thalamus, cortical white matter and spinal cord gray matter. In vivo studies demonstrate displaceable binding of [35S]ACPPB in rat brain tissues following iv administration of this radioligand. CONCLUSIONS: This is the first report of detailed anatomical localization of GlyT1 using direct radioligand binding, and the first demonstration that an in vivo occupancy assay is feasible, suggesting that it may also be feasible to develop positron emission tomography tracers for GlyT1.