The extent of intrauterine growth restriction determines the severity of cerebral injury and neurobehavioural deficits in rodents

Background

Cerebral Palsy (CP) is the most common physical pediatric neurodevelopmental disorder and spastic diplegic injury is its most frequent subtype. CP results in substantial neuromotor and cognitive impairments that have significant socioeconomic impact. Despite this, its underlying pathophysiological mechanisms and etiology remain incompletely understood. Furthermore, there is a need for clinically relevant injury models, which a) reflect the heterogeneity of the condition and b) can be used to evaluate new translational therapies. To address these key knowledge gaps, we characterized a chronic placental insufficiency (PI) model, using bilateral uterine artery ligation (BUAL) of dams. This injury model results in intrauterine growth restriction (IUGR) in pups, and animals recapitulate the human phenotype both in terms of neurobehavioural and anatomical deficits.

Methods

Effects of BUAL were studied using luxol fast blue (LFB)/hematoxylin & eosin (H&E) staining, immunohistochemistry, quantitative Magnetic Resonance Imaging (MRI), and Catwalk neurobehavioural tests.

Results

Neuroanatomical analysis revealed regional ventricular enlargement and corpus callosum thinning in IUGR animals, which was correlated with the extent of growth restriction. Olig2 staining revealed reductions in oligodendrocyte density in white and grey matter structures, including the corpus callosum, optic chiasm, and nucleus accumbens. The caudate nucleus, along with other brain structures such as the optic chiasm, internal capsule, septofimbrial and lateral septal nuclei, exhibited reduced size in animals with IUGR. The size of the pretectal nucleus was reduced only in moderately injured animals. MAG/NF200 staining demonstrated reduced myelination and axonal counts in the corpus callosum of IUGR animals. NeuN staining revealed changes in neuronal density in the hippocampus and in the thickness of hippocampal CA2 and CA3 regions. Diffusion weighted imaging (DWI) revealed regional white and grey matter changes at 3 weeks of age. Furthermore, neurobehavioural testing demonstrated neuromotor impairments in animals with IUGR in paw intensities, swing speed, relative print positions, and phase dispersions.

Conclusions

We have characterized a rodent model of IUGR and have demonstrated that the neuroanatomical and neurobehavioural deficits mirror the severity of the IUGR injury. This model has the potential to be applied to examine the pathobiology of and potential therapeutic strategies for IUGR-related brain injury. Thus, this work has potential translational relevance for the study of CP.

Methylprednisolone Reduces Persistent Post-ischemic Inflammation in a Rat Hypoxia-Ischemia Model of Perinatal Stroke

In perinatal stroke, the initial injury results in a chronic inflammatory response caused by the release of proinflammatory cytokines, gliosis and microglia activation. This chronic and ongoing inflammatory response exacerbates the brain injury, often resulting in encephalopathy and cerebral palsy (CP). Using a neonatal rat model of hypoxia-ischemia (HI) at postnatal day (P)7, we demonstrated that chronic inflammation is persistent and continues into the tertiary phase of perinatal stroke and can be attenuated by the administration of methylprednisolone sodium-succinate (MPSS, 30 mg/kg), a US Food and Drug Administration (FDA) approved anti-inflammatory agent. The inflammatory response was assessed by real-time quantitative PCR and ELISA for markers of inflammation (CCL3, CCL5, IL18 and TNFα). Structural changes were evaluated by histology (LFB/H&E), while cellular changes were assessed by Iba-1, ED1, GFAP, NeuN, Olig2 and CC1 immunostaining. Functional deficits were assessed with the Cylinder test and Ladder Rung Walking test. MPSS was injected 14 days after HI insult to attenuate chronic inflammation. In neonatal conditions such as CP, P21 is a clinically relevant time-point in rodents, corresponding developmentally to a 2-year-old human. Administration of MPSS resulted in reduced structural damage (corpus callosum, cortex, hippocampus, striatum), gliosis and reactive microglia and partial restoration of the oligodendrocyte population. Furthermore, significant behavioural recovery was observed. In conclusion, we demonstrated that administration of MPSS during the tertiary phase of perinatal stroke results in attenuation of the chronic inflammatory response, leading to pathophysiological and functional recovery. This work validates the high clinical impact of MPSS to treat neonatal conditions linked to chronic inflammation.

Severe-combined immunodeficient rats can be used to generate a model of perinatal hypoxic-ischemic brain injury to facilitate studies of engrafted human neural stem cells

Cerebral palsy (CP) encompasses a group of non-progressive brain disorders that are often acquired through perinatal hypoxic-ischemic (HI) brain injury. Injury leads to a cascade of cell death events, resulting in lifetime motor and cognitive deficits. There are currently no treatments that can repair the resulting brain damage and improve functional outcomes. To date, preclinical research using neural precursor cell (NPC) transplantation as a therapy for HI brain injury has shown promise. To translate this treatment to the clinic, it is essential that human-derived NPCs also be tested in animal models, however, a major limitation is the high risk of xenograft rejection. A solution is to transplant the cells into immune-deficient rodents, but there are currently no models of HI brain injury established in such a cohort of animals. Here, we demonstrate that a model of HI brain injury can be generated in immune-deficient Prkdc knockout (KO) rats. Long-term deficits in sensorimotor function were similar between KO and wildtype (WT) rats. Interestingly, some aspects of the injury were more severe in KO rats. Additionally, human induced pluripotent stem cell derived (hiPSC)-NPCs had higher survival at 10 weeks post-transplant in KO rats when compared to their WT counterparts. This work establishes a reliable model of neonatal HI brain injury in Prkdc KO rats that will allow for future transplantation, survival, and long-term evaluation of the safety and efficacy of hiPSC-NPCs for neonatal brain damage. This model will enable critical preclinical translational research using human NPCs.

Physician Executive Leadership Plus: An Approach to Business and Management Education for Medical Students

INTRODUCTION

Physicians are looked upon to lead the healthcare team, a task that has grown increasingly complex and interdisciplinary, requiring a diverse extra-clinical skillset. Physician Executive Leadership (PEL) Plus is a student-run program that uniquely utilizes both didactic and real-world project-based approaches to deliver a business and management curriculum to medical students.

METHODS

We developed and implemented PEL Plus during the 2018-19 and 2019-20 academic years, geared at first- and second-year medical students. We provide an overview of this combined didactic and project-based curriculum, in addition to evaluating if the program was efficacious in teaching the desired skillset. We assessed short-term knowledge acquisition using multiple-choice questions, and investigated student perceptions of their learning and the program using Likert scales and narrative feedback. We also investigated the influence of student demographics on performance, in order to assess the appropriateness of our target audience.

RESULTS

28 students completed PEL Plus over the two years (14 students/year). Average performance on multiple-choice questions showed statistically significant improvement after the majority of sessions. There were no statistically significant effects of demographics on performance in the majority of sessions. Students self-rated stronger understandings of lecture topics after each session, and analysis of narrative feedback demonstrated thematic categories centred on teaching style, new knowledge, lecture content/material, projects, networking, program structure, and generic statements.

DISCUSSION

PEL Plus is an innovative and effective approach to teaching business, leadership, and management skills in undergraduate medical education. Development of similar programs at other institutions will positively impact the broader medical student community.

Granulomatosis with polyangiitis masquerading as pituitary adenoma with apoplexy

Granulomatosis with polyangiitis (GPA), formerly known as Wegener's granulomatosis, is a small- and medium-vessel autoimmune vasculitis. Rare presentations of GPA can manifest as ophthalmologic and endocrinological deficits with sellar enhancement on imaging. While GPA typically presents distinct in appearance from other sellar pathologies, such as pituitary adenoma, we report the case of a 41-year-old woman with GPA of the pituitary that was initially diagnosed as pituitary macroadenoma with apoplexy and treated with two surgical resections without improvement of clinical symptoms. Pathology analysis of the second resection specimen revealed an inflammatory process consistent with GPA. After the pathologic and clinical diagnosis of GPA was established, treatment with steroid and steroid-sparing immunosuppressants resulted in improvements both on imaging and symptomatically. We discuss important aspects of the diagnosis and treatment of this rare presentation of GPA.

Rapidly progressive ACTH-dependent Cushing’s disease masquerading as ectopic ACTH-producing Cushing’s syndrome: illustrative case

BACKGROUND

Cushing’s disease (CD) remains a challenging condition to diagnose and treat. This case study highlights the challenges of diagnosing CD when faced with discrepant clinical, biochemical, and radiological findings.

OBSERVATIONS

A 62-year-old man presented with rapid evolution of symptoms, including depression, fatigue, and extreme muscle atrophy, which resulted in the patient being a wheelchair user over the course of a few months. His rapid clinical course in conjunction with hypercortisolemia in the setting of a pituitary macroadenoma involving the cavernous sinus, two large pulmonary nodules, and urine-free cortisol levels in the thousands suggested an aggressive ectopic adrenocorticotropic hormone (ACTH) source. After extensive testing ruled out CD from an ectopic source and because of the patient’s abrupt clinical deterioration, the authors concluded that the source was likely an aggressive pituitary adenoma. Therefore, the authors performed an endonasal transsphenoidal approach for resection of the pituitary adenoma involving the cavernous sinus, and the patient was scheduled for radiosurgery to control tumor progression.

LESSONS

Although extremely high levels of cortisol and ACTH are associated with ectopic Cushing’s syndrome, they may also indicate an aggressive form of CD. Suspicion should be maintained for hypercortisolemia from a pituitary source even when faced with discrepant information that may suggest an ectopic source.

Pediatric Primary Care Diagnoses Among Children with Intrauterine Opioid Exposure

BACKGROUND AND OBJECTIVES

Characterizing common concerns for children with intrauterine opioid exposure (IOE) can inform tailored primary care.

METHODS

Retrospective analysis of primary care data of children with IOE from birth to age two years within one multi-state pediatric health system. Well child care (WCC) and problem-based visit diagnoses were categorized, and descriptive statistics were tabulated.

RESULTS

Three hundred and eighty-five (385) children with IOE had 3,622 primary care visits, of which 51.4% were WCC and 48.6% were problem-based. Most frequent visit diagnoses were upper respiratory complaints (14.8% of visits), feeding difficulties (12.2%), and perinatal viral exposure (9.8%). Although visit type (WCC vs. problem-based) varied across diagnostic category, frequent utilization of both visit types were documented for several diagnoses in infancy (e.g., fussiness/colic, feeding difficulties).

CONCLUSIONS

Well child care visits for children with IOE are key opportunities for anticipatory guidance with an emphasis on problems that may contribute to acute health care utilization, particularly in early infancy.

The Robison D. Harley, MD Childhood Glaucoma Research Network International Pediatric Glaucoma Registry: The First 872 Cases

PURPOSE

To report on epidemiologic data from an international, centralized pediatric glaucoma database of 872 patients, focusing on genetic and clinically significant factors.

DESIGN

Database study utilizing retrospective analysis.

SUBJECTS

Eight hundred seventy-two children, both female and male, were included in the database. After accounting for database coding errors, data from 865 patients with pediatric glaucoma were analyzed. Number of eyes analyzed fluctuated for each variable.

METHODS

The registry is an open access, no charge, Research Electronic Data Capture database. Participating clinical centers input data with local Institutional Review Board approval and subsequently have access for research purposes. We retrospectively reviewed 872 patients, comparing demographics, family history, country, disease presentation, and Childhood Glaucoma Research Network diagnoses. Analyses for each variable were conducted in SPSS Software v.28.0. Chi-square analyses were performed for nominal data, and ordinal and continuous data were analyzed using Mann-Whitney test, analysis of variance, or Kruskal-Wallis tests with multiple comparisons.

MAIN OUTCOME MEASURES

Childhood Glaucoma Research Network glaucoma type and markers of clinical severity by country (laterality, cup-to-disc ratio [CTD], corneal diameter, opacification, edema; visual acuity [VA], intraocular pressure, Haab striae, axial length).

RESULTS

Twenty clinical sites from 10 countries entered data. Centers in the USA, India, and Iran input the most data. In the USA, open-angle glaucoma following cataract surgery was most common, while in India and Iran it was primary congenital glaucoma neonatal onset. Bilateral disease was more frequent in India and Iran compared to the USA (X2 = 50.6, P < 0.001). Clinical measures of severity were typically worse in India compared to the USA. This included increased CTD (X2 = 24.0, P = 0.002), increased corneal diameter (X2 = 8.9, P = 0.01), presence of corneal opacification (X2 = 10.7, P = 0.001), presence of corneal edema (X2 = 11.7, P < 0.001), and worse VA (U = 873.5, P < 0.001). Intraocular pressure and presence of Haab striae were not associated with country (P > 0.05), while axial length was increased in the USA by an average of 1.04 mm (U = 5787, P = 0.002).

CONCLUSIONS

This registry has potential to advance our understanding of pediatric glaucoma. Differences in family history, disease presentation, and glaucoma type suggest unique country phenotypes. Registry expansion may allow for insight into best practices for pediatric glaucoma.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.