Microinjection With Nanoparticles to Deliver Drugs in Prenatal Lung Explants - A Pilot Study for Prenatal Therapy in Congenital Diaphragmatic Hernia.

BACKGROUND: Fetoscopic endoluminal tracheal occlusion (FETO) improves the survival rate in fetuses with severe congenital diaphragmatic hernia (CDH). We hypothesize that prenatal therapies into the trachea during FETO can further improve outcomes. Here, we present an ex vivo microinjection technique with rat lung explants to study prenatal therapy with nanoparticles. METHODS: We used microsurgery to isolate lungs from rats on embryonic day 18. We injected chitosan nanoparticles loaded with fluorescein (FITC) into the trachea of the lung explants. We compared the difference in biodistribution of two types of nanoparticles, functionalized IgG-conjugated nanoparticles (IgG-nanoparticles) and bare nanoparticles after 24 h culture with immunofluorescence (IF). We used IF to mark lung epithelial cells with E-cadherin and to investigate an apoptosis (Active-caspase 3) and inflammatory marker (Interleukin, IL-6) and compared its abundance between the two experimental groups and control lung explants. RESULTS: We detected the presence of nanoparticles in the lung explants, and the relative number of nanoparticles to cells was 2.49 fold higher in IgG-nanoparticles than bare nanoparticles (p < 0.001). Active caspase-3 protein abundance was similar in the control, bare nanoparticles (1.20 fold higher), and IgG-nanoparticles (1.34 fold higher) groups (p = 0.34). Similarly, IL-6 protein abundance was not different in the control, bare nanoparticles (1.13 fold higher), and IgG-nanoparticles (1.12 fold higher) groups (p = 0.33). CONCLUSIONS: Functionalized nanoparticles had a higher presence in lung cells and this did not result in more apoptosis or inflammation. Our proof-of-principle study will guide future research with therapies to improve lung development prenatally. LEVELS OF EVIDENCE: N/A TYPE OF STUDY: Animal and laboratory study.

Imaging Cancer in Neuroradiology.

Neuroimaging plays a pivotal role in the diagnosis, management, and prognostication of brain tumors. Recently, the World Health Organization published the fifth edition of the WHO Classification of Tumors of the Central Nervous System (CNS5), which places greater emphasis on tumor genetics and molecular markers to complement the existing histological and immunohistochemical approaches. Recent advances in computational power allowed modern neuro-oncological imaging to move from a strictly morphology-based discipline to advanced neuroimaging techniques with quantifiable tissue characteristics such as tumor cellularity, microstructural organization, hemodynamic, functional, and metabolic features, providing more precise tumor diagnosis and management. The aim of this review is to highlight the key imaging features of the recently published CNS5, outlining the current imaging standards and summarizing the latest advances in neuro-oncological imaging techniques and their role in complementing traditional brain tumor imaging and management.

Skull base infections, their complications, and management.

OBJECTIVE: Our review aims to summarize the current literature on skull base infections (SBIs) and retrospectively analyze any such cases encountered at our institution. DESIGN: A literature search was conducted using online databases PubMed, MEDLINE, and ResearchGate with the terms "skull base osteomyelitis," "temporal bone osteomyelitis," "skull base infections," "necrotizing otitis media," and "SBO". References from the resulting manuscripts were reviewed for relevant articles. A search of our electronic health records using the same key terms was also performed to identify patients with a tissue biopsy-confirmed diagnosis of skull base infections. Patients with an indeterminate diagnosis or inaccessible/poor imaging were excluded. SETTING: A level one trauma and major tertiary academic medical center. PARTICIPANTS: All patients treated at the University of California Davis Health System with a confirmed diagnosis of skull base infections from January 2005 to November 2020. MAIN OUTCOME MEASURES: Imaging results, symptoms, treatment, morbidity, and mortality. RESULTS: Our literature search yielded 59 articles ranging from 1982 to 2021. A retrospective search of our electronic health records identified two cases of skull base infections. CONCLUSION: Skull base infections have no pathognomonic findings. A multimodal approach with computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine is necessary to characterize the disease process in addition to a biopsy for definitive diagnosis. Other diagnoses can mimic SBI on imaging, such as nasopharyngeal carcinoma and inflammatory pseudotumor. Culture-guided antimicrobial treatment and surgery are mainstay therapies. Other adjuvant strategies currently lack the robust evidence necessary to characterize their risks and benefits.

Multimodal neuroimaging in pediatric type 1 diabetes: a pilot multisite feasibility study of acquisition quality, motion, and variability.

Type 1 diabetes (T1D) affects over 200,000 children and is associated with an increased risk of cognitive dysfunction. Prior imaging studies suggest the neurological changes underlying this risk are multifactorial, including macrostructural, microstructural, and inflammatory changes. However, these studies have yet to be integrated, limiting investigation into how these phenomena interact. To better understand these complex mechanisms of brain injury, a well-powered, prospective, multisite, and multimodal neuroimaging study is needed. We take the first step in accomplishing this with a preliminary characterization of multisite, multimodal MRI quality, motion, and variability in pediatric T1D. We acquire structural T1 weighted (T1w) MRI, diffusion tensor MRI (DTI), functional MRI (fMRI), and magnetic resonance spectroscopy (MRS) of 5-7 participants from each of two sites. First, we assess the contrast-to-noise ratio of the T1w MRI and find no differences between sites. Second, we characterize intervolume motion in DTI and fMRI and find it to be on the subvoxel level. Third, we investigate variability in regional gray matter volumes and local gyrification indices, bundle-wise DTI microstructural measures, and N-acetylaspartate to creatine ratios. We find the T1-based measures to be comparable between sites before harmonization and the DTI and MRS-based measures to be comparable after. We find a 5-15% coefficient of variation for most measures, suggesting ~150-200 participants per group on average are needed to detect a 5% difference across these modalities at 0.9 power. We conclude that multisite, multimodal neuroimaging of pediatric T1D is feasible with low motion artifact after harmonization of DTI and MRS.

Altered Development of Amygdala-Connected Brain Regions in Males and Females with Autism.

Altered amygdala development is implicated in the neurobiology of autism, but little is known about the coordinated development of the brain regions directly connected with the amygdala. Here we investigated the volumetric development of an amygdala-connected network, defined as the set of brain regions with monosynaptic connections with the amygdala, in autism from early to middle childhood. A total of 950 longitudinal structural MRI scans were acquired from 282 children (93 female) with autism and 128 children with typical development (61 female) at up to four time points (mean ages: 39, 52, 64, and 137 months, respectively). Volumes from 32 amygdala-connected brain regions were examined using mixed effects multivariate distance matrix regression. The Social Responsiveness Scale-2 was administered to assess degree of autistic traits and social impairments. The amygdala-connected network exhibited persistent diagnostic differences (p values ≤ 0.03) that increased over time (p values ≤ 0.02). These differences were most prominent in autistics with more impacted social functioning at baseline. This pattern was not observed across regions without monosynaptic amygdala connection. We observed qualitative sex differences. In males, the bilateral subgenual anterior cingulate cortices were most affected, while in females the left fusiform and superior temporal gyri were most affected. In conclusion, (1) autism is associated with widespread alterations to the development of brain regions connected with the amygdala, which were associated with autistic social behaviors; and (2) autistic males and females exhibited different patterns of alterations, adding to a growing body of evidence of sex differences in the neurobiology of autism.SIGNIFICANCE STATEMENT Global patterns of development across brain regions with monosynaptic connection to the amygdala differentiate autism from typical development, and are modulated by social functioning in early childhood. Alterations to brain regions within the amygdala-connected network differed in males and females with autism. Results also indicate larger volumetric differences in regions having monosynaptic connection with the amygdala than in regions without monosynaptic connection.

Autoimmune disease of head and neck, imaging, and clinical review.

Autoimmune disease of the head and neck (H&N) could be primary or secondary to systemic diseases, medications, or malignancies. Immune-mediated diseases of the H&N are not common in daily practice of radiologists; the diagnosis is frequently delayed because of the non-specific initial presentation and lack of familiarity with some of the specific imaging and clinical features. In this review, we aim to provide a practical diagnostic approach based on the specific radiological findings for each disease. We hope that our review will help radiologists expand their understanding of the spectrum of the discussed disease entities, help them narrow the differential diagnosis, and avoid unnecessary tissue biopsy when appropriate based on the specific clinical scenarios.

Bilateral external auditory canal masses following repair of ruptured abdominal aortic aneurysm and open decompressive exploratory laparotomy for compartment syndrome: A rare case of spontaneous bilateral otorrhagia.

Very few cases of spontaneous otorrhagia (SO) following nonotolaryngologic surgery have ever been reported in surgical literature and none in radiographic. Of the surgical cases reported, SO occurred in the perioperative period following laparoscopic surgeries in the Trendelenburg position. We report the first case of spontaneous bilateral otorrhagia which presented as bilateral external auditory canal masses following endovascular surgery and open decompressive laparotomy in a 60-year-old male with a prior history of hypertension and smoking. We seek to inform radiologists that SO can present on neck imaging as external auditory canal masses as a complication of nonotolaryngologic surgery away from the imaged field of view.

MR imaging findings of a rare pediatric parotid tumor: Mammary analogue secretory carcinoma.

We present magnetic resonance imaging findings of an 11-year-old girl with a mammary analogue secretory carcinoma (MASC) of the parotid gland. MASC is a recently described tumor of the salivary glands that is genetically and histologically similar to secretory breast carcinoma. To date, a few cases have been reported in the pediatric population, with limited information of its imaging characteristics. We suggest that decreased T2 signal of the solid component of the MASC representing cellular components with associated complex cystic parts may be a helpful imaging finding and can make a substantial contribution in differentiating this new entity from other rare pediatric parotid masses. Although there are no characteristic imaging findings at this time, MASC should be considered in the differential of salivary gland tumors in the pediatric population as well.

A Comprehensive Review of Cross-Sectional Imaging of the Nasolacrimal Drainage Apparatus: What Radiologists Need to Know.

OBJECTIVE. The purpose of this study is to provide a comprehensive review of the radiographic anatomy and cross-sectional imaging findings of the full gamut of nasolacrimal drainage apparatus diseases, highlighting imaging findings from the different nasolacrimal drainage apparatus surgeries, posttreatment complications, and potential imaging pitfalls. CONCLUSION. Radiologists play a critical role in guiding the management of nasolacrimal drainage apparatus diseases and should be familiar with the anatomy and characteristic imaging findings of commonly encountered nasolacrimal drainage apparatus abnormalities and surgeries.

Age-related mortality in abusive head trauma.

BACKGROUND: Abusive head trauma (AHT) peaks during early infancy and decreases in toddler years. Infants and toddlers experience different injuries, possibly impacting the risk of mortality. We aimed to evaluate the association of age with mortality. METHODS: We conducted a retrospective study of AHT hospitalizations in 2000, 2003, 2006, 2009, and 2012 from the Kid's Inpatient Claims Database. An accidental head trauma cohort was included to hypothesize that the association between age and mortality is unique to abuse. A nested multivariable logistic regression was used to perform the analysis. RESULTS: Children aged 2 years to 4 years experienced higher mortality than those younger than 2 years (22% vs. 10%, p < 0.0001; adjusted odds ratio [OR], 1.6; 95% confidence interval [CI], 1.1-2.2). The presence of subarachnoid hemorrhage (OR, 1.9; 95% CI, 1.3-2.9), cerebral edema (OR, 4.0; 95% CI, 2.9-5.4), and retinal hemorrhage (OR, 1.9; 95% CI, 1.5-2.5) were associated with an increase risk in mortality. Children younger than 2 years experienced more fractures and hemorrhage (subdural, subarachnoid, retinal) while children aged 2 years to 4 years encountered more internal injuries and cerebral edema.In children with accidental head trauma, those aged 2 years to 4 years have a lower mortality compared with those younger than 2 years (OR, 0.4; 95% CI, 0.3-0.6). Among children younger than 2 years, AHT and accidental trauma had comparable risk of mortality (OR, 0.9; 95% CI, 0.6-1.3). However, among those aged 22 years to 4 years, AHT had a higher risk of mortality than accidental trauma (OR, 3.3; 95% CI, 2.1-5.1). CONCLUSION: There is a considerable risk of mortality associated with age at diagnosis in children with AHT.Children younger than 2 years and those aged 2 years to 4 years present with different types of injuries. The high risk of mortality in the children aged 2 years to 4 years is unique to AHT. Efforts should be made to increase awareness about the risk of mortality and identify factors that can aide in a timely accurate diagnosis. LEVEL OF EVIDENCE: Prognostic and epidemiological study, level III.

Claudin 1 Is Highly Upregulated by PKC in MCF7 Human Breast Cancer Cells and Correlates Positively with PKCε in Patient Biopsies.

Recent studies provide compelling evidence to suggest that the tight junction protein claudin 1, aberrantly expressed in several cancer types, plays an important role in cancer progression. Dysregulation of claudin 1 has been shown to induce epithelial mesenchymal transition (EMT). Furthermore, activation of the ERK signaling pathway by protein kinase C (PKC) was shown to be necessary for EMT induction. Whether PKC is involved in regulating breast cancer progression has not been addressed. The PKC activator 12-O-tetradecanoylphorbol 13-acetate (TPA) was used to investigate the effect of PKC activity on claudin 1 transcription and protein levels, subcellular distribution, and alterations in EMT markers in human breast cancer (HBC) cell lines. As well, tissue microarray analysis (TMA) of a large cohort of invasive HBC biopsies was conducted to investigate correlations between claudin 1 and PKC isomers. TPA upregulated claudin 1 levels in all HBC cell lines analyzed. In particular, a high induction of claudin 1 protein was observed in the MCF7 cell line. TPA treatment also led to an accumulation of claudin 1 in the cytoplasm. Additionally, we demonstrated that the upregulation of claudin 1 was through the ERK signaling pathway. In patient biopsies, we identified a significant positive correlation between claudin 1, PKCα, and PKCε in ER+ tumors. A similar correlation between claudin 1 and PKCε was identified in ER- tumors, and high PKCε was associated with shorter disease-free survival. Collectively, these studies demonstrate that claudin 1 and the ERK signaling pathway are important players in HBC progression.

MicroRNA-200b regulates distal airway development by maintaining epithelial integrity.

miR-200b plays a role in epithelial-to-mesenchymal transition (EMT) in cancer. We recently reported abnormal expression of miR-200b in the context of human pulmonary hypoplasia in congenital diaphragmatic hernia (CDH). Smaller lung size, a lower number of airway generations, and a thicker mesenchyme characterize pulmonary hypoplasia in CDH. The aim of this study was to define the role of miR-200b during lung development. Here we show that miR-200b-/- mice have abnormal lung function due to dysfunctional surfactant, increased fibroblast-like cells and thicker mesenchyme in between the alveolar walls. We profiled the lung transcriptome in miR-200b-/- mice, and, using Gene Ontology analysis, we determined that the most affected biological processes include cell cycle, apoptosis and protein transport. Our results demonstrate that miR-200b regulates distal airway development through maintaining an epithelial cell phenotype. The lung abnormalities observed in miR-200b-/- mice recapitulate lung hypoplasia in CDH.

FUS-regulated RNA metabolism and DNA damage repair: Implications for amyotrophic lateral sclerosis and frontotemporal dementia pathogenesis.

Cytoplasmic inclusion of RNA binding protein FUS/TLS in neurons and glial cells is a characteristic pathology of a subgroup of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Dysregulation of RNA metabolism caused by FUS cytoplasmic inclusion emerges to be a key event in FUS-associated ALS/FTD pathogenesis. Our recent discovery of a FUS autoregulatory mechanism and its dysregulation in ALS-FUS mutants demonstrated that dysregulated alternative splicing can directly exacerbate the pathological FUS accumulation. We show here that FUS targets RNA for pre-mRNA alternative splicing and for the processing of long intron-containing transcripts, and that these targets are enriched for genes in neurogenesis and gene expression regulation. We also identify that FUS RNA targets are enriched for genes in the DNA damage response pathway. Together, the data support a model in which dysregulated RNA metabolism and DNA damage repair together may render neurons more vulnerable and accelerate neurodegeneration in ALS and FTD.

ALS-associated FUS mutations result in compromised FUS alternative splicing and autoregulation.

The gene encoding a DNA/RNA binding protein FUS/TLS is frequently mutated in amyotrophic lateral sclerosis (ALS). Mutations commonly affect its carboxy-terminal nuclear localization signal, resulting in varying deficiencies of FUS nuclear localization and abnormal cytoplasmic accumulation. Increasing evidence suggests deficiencies in FUS nuclear function may contribute to neuron degeneration. Here we report a novel FUS autoregulatory mechanism and its deficiency in ALS-associated mutants. Using FUS CLIP-seq, we identified significant FUS binding to a highly conserved region of exon 7 and the flanking introns of its own pre-mRNAs. We demonstrated that FUS is a repressor of exon 7 splicing and that the exon 7-skipped splice variant is subject to nonsense-mediated decay (NMD). Overexpression of FUS led to the repression of exon 7 splicing and a reduction of endogenous FUS protein. Conversely, the repression of exon 7 was reduced by knockdown of FUS protein, and moreover, it was rescued by expression of EGFP-FUS. This dynamic regulation of alternative splicing describes a novel mechanism of FUS autoregulation. Given that ALS-associated FUS mutants are deficient in nuclear localization, we examined whether cells expressing these mutants would be deficient in repressing exon 7 splicing. We showed that FUS harbouring R521G, R522G or ΔExon15 mutation (minor, moderate or severe cytoplasmic localization, respectively) directly correlated with respectively increasing deficiencies in both exon 7 repression and autoregulation of its own protein levels. These data suggest that compromised FUS autoregulation can directly exacerbate the pathogenic accumulation of cytoplasmic FUS protein in ALS. We showed that exon 7 skipping can be induced by antisense oligonucleotides targeting its flanking splice sites, indicating the potential to alleviate abnormal cytoplasmic FUS accumulation in ALS. Taken together, FUS autoregulation by alternative splicing provides insight into a molecular mechanism by which FUS-regulated pre-mRNA processing can impact a significant number of targets important to neurodegeneration.

Axial 3D gradient-echo imaging for improved multiple sclerosis lesion detection in the cervical spinal cord at 3T.

INTRODUCTION: In multiple sclerosis (MS), spinal cord imaging can help in diagnosis and follow-up evaluation. However, spinal cord magnetic resonance imaging (MRI) is technically challenging, and image quality, particularly in the axial plane, is typically poor compared to brain MRI. Because gradient-recalled echo (GRE) images might offer improved contrast resolution within the spinal cord at high magnetic field strength, both without and with a magnetization transfer prepulse, we compared them to T2-weighted fast-spin-echo (T2-FSE) images for the detection of MS lesions in the cervical cord at 3T. METHODS: On a clinical 3T MRI scanner, we studied 62 MS cases and 19 healthy volunteers. Axial 3D GRE sequences were performed without and with off-resonance radiofrequency irradiation. To mimic clinical practice, all images were evaluated in conjunction with linked images from a sagittal short tau inversion recovery scan, which is considered the gold standard for lesion detection in MS. Two experienced observers recorded image quality, location and size of focal lesions, atrophy, swelling, and diffuse signal abnormality independently at first and then in consensus. RESULTS: The number and volume of lesions detected with high confidence was more than three times as high on both GRE sequences compared to T2-FSE (p < 0.0001). Approximately 5 % of GRE scans were affected by artifacts that interfered with image interpretation, not significantly different from T2W-FSE. CONCLUSIONS: Axial 3D GRE sequences are useful for MS lesion detection when compared to 2D T2-FSE sequences in the cervical spinal cord at 3T and should be considered when examining intramedullary spinal cord lesions.

Superficial temporal artery calcification in patients with end-stage renal disease: Association with vascular risk factors and ischemic cerebrovascular disease.

BACKGROUND AND PURPOSE: Extracranial superficial temporal artery (STA) calcification is an unusual finding seen in patients with chronic kidney disease and has unknown ramifications with respect to intracranial ischemic disease. We sought to determine the association between the risk factors for vascular calcification and this rare phenomenon, in patients with chronic renal failure, and to assess the coexistence of cerebral ischemia. MATERIALS AND METHODS: Medical records and laboratory data on risk factors for vascular calcification were retrospectively retrieved for 453 patients with a discharge diagnosis of end-stage renal disease (ESRD). CT head examinations were reviewed to identify and associate STA calcification with 1) risk factors for the vascular calcification, 2) intracranial artery calcification, and 3) cerebral ischemia (white matter and/or cortical ischemic changes). RESULTS: STA calcification was present in 9.9% (45/453) of the studied cohort. The prevalence of cerebral ischemia was 24.4% (11/45) in patients with STA calcification and 9.3% (38/408) in patients without it. Diabetes mellitus (OR: 2.56, 95% CI: 1.059-6.208; P=0.037) was independently associated with the risk of STA calcification. The risk of cerebral ischemia, however, was not related to STA calcification (P=0.221). CONCLUSION: The presence of diabetes mellitus is important in describing the risk of STA calcification in patients with ESRD, whereas age, gender, hypertension, serum calcium, serum phosphate, or serum hemoglobin levels are not. The risk of cerebral ischemia is not related to STA calcification but has the strongest association with diabetes mellitus.

miR-34 miRNAs provide a barrier for somatic cell reprogramming.

Somatic reprogramming induced by defined transcription factors is a low-efficiency process that is enhanced by p53 deficiency. So far, p21 is the only p53 target shown to contribute to p53 repression of iPSC (induced pluripotent stem cell) generation, indicating that additional p53 targets may regulate this process. Here, we demonstrate that miR-34 microRNAs (miRNAs), particularly miR-34a, exhibit p53-dependent induction during reprogramming. Mir34a deficiency in mice significantly increased reprogramming efficiency and kinetics, with miR-34a and p21 cooperatively regulating somatic reprogramming downstream of p53. Unlike p53 deficiency, which enhances reprogramming at the expense of iPSC pluripotency, genetic ablation of Mir34a promoted iPSC generation without compromising self-renewal or differentiation. Suppression of reprogramming by miR-34a was due, at least in part, to repression of pluripotency genes, including Nanog, Sox2 and Mycn (also known as N-Myc). This post-transcriptional gene repression by miR-34a also regulated iPSC differentiation kinetics. miR-34b and c similarly repressed reprogramming; and all three miR-34 miRNAs acted cooperatively in this process. Taken together, our findings identified miR-34 miRNAs as p53 targets that play an essential role in restraining somatic reprogramming.

Single-dose thymoglobulin induction in living-donor renal transplantation.

BACKGROUND: The use of Thymoglobulin induction therapy in living-donor renal transplantation remains controversial. We aimed to evaluate outcomes in living-related donor (LRD) and living unrelated donor (LURD) renal transplants with Thymoglobulin induction. MATERIAL/METHODS: We retrospectively analysed the outcome of all Thymoglobulin induced living-donor renal transplants performed at our centre from 2002 to 2010. RESULTS: We reviewed 100 living-donor renal transplants (LRD=60; LURD=40) who received thymoglobulin induction (single dose, 1.5 mg/kg bodyweight) with a mean follow-up of 52.6 ± 31.9 months. Although baseline characteristics of the LRD and LURD groups were similar, differences were noted for recipient age, gender, and HLA-matching. Overall, the estimated 5-year patient survival was 92% and graft survival, 83%. The 1- and 5-year patient survival rates were 97.4% and 90.7% for LRD and 98.3% and 92.2% for LURD (P=0.79), respectively. Cumulative graft survival (LRD vs. LURD) rates were 93% vs. 95% after 1 year and 80% vs. 88% after 5 years (P=0.53). Kidney graft function was comparable for both the groups. Acute rejection was observed in 17% LRD and 35% LURD patients (P=0.035). Further, 10% of the patients experienced delayed graft function (LRD 11% vs. LURD 8%; P=NS). Rates of cytomegalovirus (CMV) infection (10%), polyomavirus infection (5%), malignancy (4%), and lymphoproliferative disorder (0%) were low, with no differences between the 2 groups. CONCLUSIONS: Single-dose thymoglobulin induction in living-donor renal transplantation was associated with high patient and graft survival without increasing the risk of infections or malignancy and without significant differences between LRD and LURD patients.

MR enterography findings of inflammatory bowel disease in pediatric patients.

OBJECTIVE: The purpose of this article is to illustrate and describe the characteristic MR enterography findings in children with inflammatory bowel disease (IBD) and to present MR enterography as the first-choice imaging modality in this setting. CONCLUSION: Given its high sensitivity and specificity for IBD and lack of ionizing radiation, MR enterography is a valuable technique for examining children with IBD.