Eric P Wartchow | University of Colorado Denver (original) (raw)
Papers by Eric P Wartchow
Microscopy and Microanalysis, 2013
Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indi... more Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.
JACC. Clinical electrophysiology, 2018
The purpose of this study was to assess the phenotype of Filamin C (FLNC) truncating variants in ... more The purpose of this study was to assess the phenotype of Filamin C (FLNC) truncating variants in dilated cardiomyopathy (DCM) and understand the mechanism leading to an arrhythmogenic phenotype. Mutations in FLNC are known to lead to skeletal myopathies, which may have an associated cardiac component. Recently, the clinical spectrum of FLNC mutations has been recognized to include a cardiac-restricted presentation in the absence of skeletal muscle involvement. A population of 319 U.S. and European DCM cardiomyopathy families was evaluated using whole-exome and targeted next-generation sequencing. FLNC truncation probands were identified and evaluated by clinical examination, histology, transmission electron microscopy, and immunohistochemistry. A total of 13 individuals in 7 families (2.2%) were found to harbor 6 different FLNC truncation variants (2 stopgain, 1 frameshift, and 3 splicing). Of the 13 FLNC truncation carriers, 11 (85%) had either ventricular arrhythmias or sudden car...
Molecular Genetics and Metabolism
Cardiac dysfunction is a common phenotypic manifestation of primary mitochondrial disease with mu... more Cardiac dysfunction is a common phenotypic manifestation of primary mitochondrial disease with multiple nuclear and mitochondrial DNA pathogenic variants as a cause, including disorders of mitochondrial translation. To date, five patients have been described with pathogenic variants in MRPL44, encoding the ml44 protein which is part of the large subunit of the mitochondrial ribosome (mitoribosome). Three presented as infants with hypertrophic cardiomyopathy, mild lactic acidosis, and easy fatigue and muscle weakness, whereas two presented in adolescence with myopathy and neurological symptoms. We describe two infants who presented with cardiomyopathy from the neonatal period, failure to thrive, hypoglycemia and in one infant lactic acidosis. A decompensation of the cardiac function in the first year resulted in demise. Exome sequencing identified compound heterozygous variants in the MRPL44 gene including the known pathogenic variant c.467 T > G and two novel pathogenic variants. We document a combined respiratory chain enzyme deficiency with emphasis on complex I and IV, affecting heart muscle tissue more than skeletal muscle or fibroblasts. We show this to be caused by reduced mitochondrial DNA encoded protein synthesis affecting all subunits, and resulting in dysfunction of complex I and IV assembly. The degree of oxidative phosphorylation dysfunction correlated with the impairment of mitochondrial protein synthesis due to different pathogenic variants. These functional studies allow for improved understanding of the pathogenesis of MRPL44-associated mitochondrial disorder.
American Journal of Respiratory Cell and Molecular Biology
European Respiratory Journal, 2020
Pulmonary interstitial glycogenosis (PIG) was first defined as a distinct neonatal interstitial l... more Pulmonary interstitial glycogenosis (PIG) was first defined as a distinct neonatal interstitial lung disease of unknown aetiology that presents in neonates and young infants with mild to severe hypoxic lung disease [1]. Characterised clinically by unexplained respiratory distress and cyanosis with an onset during early infancy, PIG was primarily defined by the presence of distinct and unusual-appearing cells contained within the interstitium that were characterised by a widened interstitium containing variable numbers of immature-appearing, polygonal-to-spindle shaped cells, which may contribute to impaired gas exchange. The most unique feature of PIG cells is the widespread presence of non-membrane bound, periodic acid-Schiff stain-positive, mono-particulate glycogen in the cytoplasm, for which the disease was named ("glycogenosis") [1]. By ultrastructure, PIG cells are considered primitive due to the presence of only sparse organelles and a lack of specific features that indicate differentiation towards any well-characterised pulmonary cell line, including lymphocytes or macrophages [1]. Observations from this landmark paper led to subsequent studies that further characterised PIG, using the presence of these novel and atypical appearing cells as the pathognomonic diagnostic hallmark [2-5]. Although initially considered a distinct disease, recent studies have identified histologic evidence of PIG in association with diverse cardiopulmonary disorders, including childhood interstitial lung disorders, congenital heart disease, bronchopulmonary dysplasia, congenital airway malformations, pulmonary hypertension, neuroendocrine cell hyperplasia of infancy and congenital lobar emphysema [2-5]. Long-term outcomes for infants with histologic findings of PIG are highly variable and may be linked with the severity of the underlying disease process associated with PIG histology; however, fatal cases have been reported even in the absence of other known primary diagnoses [2-5]. Clinical, imaging, bronchoscopic and genetic findings are not specific for PIG and diagnosis still requires lung biopsy.
.................................................................................................... more ............................................................................................................................ ii ACKNOWLEDGMENTS ....................................................................................................... iv TABLE OF CONTENTS ......................................................................................................... v LIST OF TABLES ................................................................................................................... vii LIST OF FIGURES ................................................................................................................. viii
Blood, 2019
Aging and chronic inflammation are independent risk factors for the development of atherothrombos... more Aging and chronic inflammation are independent risk factors for the development of atherothrombosis and cardiovascular disease. We hypothesized that aging-associated inflammation promotes the development of platelet hyperreactivity and increases thrombotic risk during aging. Functional platelet studies in aged-frail adults and old mice demonstrated that their platelets are hyperreactive and form larger thrombi. We identified tumor necrosis factor α (TNF-α) as the key aging-associated proinflammatory cytokine responsible for platelet hyperreactivity. We further showed that platelet hyperreactivity is neutralized by abrogating signaling through TNF-α receptors in vivo in a mouse model of aging. Analysis of the bone marrow compartments showed significant platelet-biased hematopoiesis in old mice reflected by increased megakaryocyte-committed progenitor cells, megakaryocyte ploidy status, and thrombocytosis. Single-cell RNA-sequencing analysis of native mouse megakaryocytes showed signi...
Journal of clinical pathology, 2015
A growing body of evidence suggests a role for altered epithelial barrier function in the pathoph... more A growing body of evidence suggests a role for altered epithelial barrier function in the pathophysiology of eosinophilic oesophagitis (EoE), but few have described the epithelial structure during inflammation. The purpose of this study was to define ultrastructural features of active, inactive EoE and control subject's oesophageal epithelia. We prospectively enrolled patients undergoing diagnostic upper endoscopy for evaluation of EoE. Mucosal pinch biopsies were obtained from the distal oesophagus and processed for routine histology and electron microscopic assessment. Clinical features of enrolled subjects were analysed and subjects were divided into four groups: normal, gastroesophageal reflux disease (GERD), inactive EoE and active EoE. Representative photomicrographs of the basal and superficial epithelia were reviewed for abnormalities. Desmosomes were quantified on the surface of epithelia three to four prickle-cell layers above the basal layer. Twenty-nine paediatric ca...
Microscopy and Microanalysis, 2017
Primary ciliary dyskinesia (PCD) is a congenital disease of the respiratory airways characterized... more Primary ciliary dyskinesia (PCD) is a congenital disease of the respiratory airways characterized by abnormal cilia structure and function. Clinical symptoms of the disease may include situs inversus, bronchiectasis, and chronic upper and lower airway infections. Transmission electron microscopic (TEM) evaluation of ciliary ultrastructure and genetic testing are the two most important components of the multimodal approach used in the diagnosis of this disease and are the only two techniques which can positively confirm a diagnosis in children under the age of 5 years old. Unlike the continuous search for PCD-associated genetic variants, few attempts been made to similarly improve the performance of the TEM analysis of ciliary biopsies. In this thesis, enhancement of the TEM examination by implementation of single-axis electron tomography for improved visualization of ciliary fine structure is explored. The analytic validity (technical performance of the test), clinical validity (power of the test to detect disease), and clinical utility (probability the test will result in improved patient outcomes) of the technique are evaluated through a multi-reader study comparing the 3D tomographic technique to conventional TEM. The study presents an analysis and discussion of data designed to thoroughly assess the role of single-axis 3D tomography in a clinical electron microscopic laboratory. The 3D iv technique is shown to be equal to conventional electron microscopy in recognizing disease. Readers report enhanced visualization of the inner dynein arms, a key ultrastructural feature within cilia for the identification of a specific PCD variant. The proportion of cases reported as inconclusive is reduced when comparing the 3D technique to the 2D technique, particularly in cases with suboptimal tissue available for evaluation. These findings have clinical relevance and prove the ability to perform single-axis 3D tomography can be a valued enhancement to the conventional 2D electron microscopic technique. The form and content of this abstract are approved. I recommend its publication. Approved: Mark. A. Lovell v DEDICATION This thesis is dedicated to my family. Each person listed on this page has a played a key role in the culmination of this project. My parents, Judy and Paul Wartchow, created an environment which nurtured a curious and independent young mind and allowed me to cultivate a lifelong interest in science. My wife Heidi has been motivating, understanding, and patient throughout the entire process. Our son, Connor, was a young man when this project began and has been a constant source of inspiration. Our daughters, Abigail and Shelby and their beautiful families, as well as my siblings, Keri and Josh, have provided me with continuous encouragement. I am grateful to each of you. vi ACKNOWLEDGEMENTS I am deeply indebted to many teachers, advisors, and colleagues who made this project possible. Dr. Josephine Taylor at Stephen F. Austin State University was the first to show me the amazing beauty of our world when viewed through the lens of an electron microscope. My colleagues in the Electron Microscopy Laboratory at Children's Hospital Colorado have provided valuable input and at times accepted additional responsibilities, allowing me to complete the Clinical Science graduate program while maintaining my position on our team. The contribution made by patients with Primary Ciliary Dyskinesia and their families is significant. The sacrifice of their time and energy to participate in a clinical study is admirable and allows the continued progress of our knowledge and understanding of this disease. Most importantly, I would like to acknowledge Dr. Gary Mierau. If there is one person with whom I should share any achievement I have enjoyed in my academic and professional career it is Gary. He has been a teacher, a mentor, and a friend for many years. I will never fully understand why he took a chance on me, but his dedication to my success has never wavered. I will be forever grateful for the knowledge and opportunities he has so generously and humbly provided.
Pediatric Pulmonology, 2018
Marijuana use has risen dramatically over the past decade. Over this same time period, pediatric ... more Marijuana use has risen dramatically over the past decade. Over this same time period, pediatric hospitals have seen an increase in presentation of adolescents with acute respiratory symptoms after recent marijuana inhalation. We report a case series of three adolescent males with significant findings of bilateral pulmonary nodules and ground glass opacities on chest imaging associated with recent marijuana inhalation. Lung biopsies in two of the three patients confirmed silica‐induced pneumoconiosis. The third patient was diagnosed with acute hypersensitivity pneumonitis without lung biopsy. Improvement in clinical symptoms and lung function testing were noted in two of three patients after marijuana inhalation cessation. This case series highlights the variety of severe pulmonary presentations in adolescents following recent marijuana inhalation. Future studies are required to assess whether these presenting pulmonary complications are from direct marijuana exposure or indirect associations with marijuana inhalation injuries.
Tanycytic ependymoma is the rarest variant of ependymoma and occurs primarily in the spinal cord.... more Tanycytic ependymoma is the rarest variant of ependymoma and occurs primarily in the spinal cord. Intracranial cases are even rarer. Only 9 ventricular and 5 subcortical tanycytic ependymoma have been reported in the literature. Amongst the 9 ventricular cases, only one tumor arose from the third ventricle. We report here another case of tanycytic ependymoma arising from the third ventricle completed with immunohistochemical, ul- trastructural, and molecular pathology study. The patient was a 44 year-old male who presented with headache, nausea and visual disturbances of a few months duration. Neuroradiological findings showed a well-defined mass arising from the posterolateral wall of third ventricle. Histologically the tumor was composed of monotonous spindle cells arranged in fascicles without definitive perivascular rosettes. The tumor cells were diffusely positive for glial fibrillary acidic protein and epithelial membrane antigen, showed faint immunoreactivity for synaptophysi...
Ultrastructural pathology
Zellweger spectrum disorders (ZSD) are rare autosomal recessive inherited metabolic disorders and... more Zellweger spectrum disorders (ZSD) are rare autosomal recessive inherited metabolic disorders and include severe (Zellweger syndrome) and milder phenotypes [neonatal adrenoleukodystrophy and infantile Refsum disease (IRD)]. ZSD are characterized by impaired peroxisomal functions and lack of peroxisomes detected by electron microscopy (EM). ZSD are caused by mutations in any of the 14 PEX genes. Patients with ZSD commonly demonstrate nonspecific hepatic symptoms within the first year, often without clinical suspicion of ZSD. Thus, recognition of pathologic findings in the liver is critical for the early diagnosis. We herein demonstrate the histologic and ultrastructural features in liver biopsies in the early and advanced phases from a 16-year-old male with IRD. The initial biopsy at 5 months of age showed a lack of peroxisomes by EM, and this finding played a critical role in the early diagnosis. In contrast, the second biopsy at 14 years of age, after long-term diet therapy, demons...
International journal of clinical and experimental pathology, 2015
Pediatric primary "small round blue cell" tumors in the CNS represent several entities,... more Pediatric primary "small round blue cell" tumors in the CNS represent several entities, some more common than others. Ewing sarcoma/peripheral primitive neuroectodermal tumor (ES/pPNET) is rare and must be distinguished from other tumors such as medulloblastoma [1, 2], atypical rhabdoid/teratoid tumor, ependymomal tumors, metastatic sarcomas, hematologic malignancies, and other mimics. Although therapy for ES/pPNET is effective, it brings severe side effects, including cardiac toxicity, making correct recognition important [3]. As small blue cell tumors look similar, diagnosis often depends on special stains, immunohistochemistry, and molecular techniques. While the combination of membranous immunohistochemical reactivity for CD99 with cytoplasmic glycogen provides effective screening, demonstration of characteristic translocations of EWSR1 (chromosome 22) or FUS (chromosome 16) by fluorescent in situ hybridization (FISH) can confirm the diagnosis. We are reporting three p...
International journal of clinical and experimental pathology, 2014
Tanycytic ependymoma is the rarest variant of ependymoma and occurs primarily in the spinal cord.... more Tanycytic ependymoma is the rarest variant of ependymoma and occurs primarily in the spinal cord. Intracranial cases are even rarer. Only 9 ventricular and 5 subcortical tanycytic ependymoma have been reported in the literature. Amongst the 9 ventricular cases, only one tumor arose from the third ventricle. We report here another case of tanycytic ependymoma arising from the third ventricle completed with immunohistochemical, ultrastructural, and molecular pathology study. The patient was a 44 year-old male who presented with headache, nausea and visual disturbances of a few months duration. Neuroradiological findings showed a well-defined mass arising from the posterolateral wall of third ventricle. Histologically the tumor was composed of monotonous spindle cells arranged in fascicles without definitive perivascular rosettes. The tumor cells were diffusely positive for glial fibrillary acidic protein and epithelial membrane antigen, showed faint immunoreactivity for synaptophysin ...
International Journal of Clinical and Experimental Pathology, 2016
Adult polyglucosan body disease (APBD) is a rare neurologic disease characterized clinically by p... more Adult polyglucosan body disease (APBD) is a rare neurologic disease characterized clinically by progressive upper and lower motor neuron dysfunction, neurogenic bladder, distal sensory loss, cerebellar dysfunction and dementia, while histologically featured by diffuse accumulation of polyglucosan bodies throughout the nervous system and in other organs. In some cases, this entity has been proved to be associated with reduced activity of glycogen branching enzyme and mutations of GBE1. We are reporting here a case of adult polyglucosan body disease with an atypical clinical presentation and imaging features that mimic a low-grade glioma. On enzymatic studies, there was reduced activity of glycogen branching enzyme in muscle but normal glycogen content. We also identified a heterozygous consensus splice site variant in intron 5 (c.691+2T>C) and a homozygous variant of unknown significance (c.-35dupC). Our case illustrates the possible clinical, imaging, pathologic, and genetic dive...
Ultrastructural Pathology
ABSTRACT Background: Although the role of electron microscopy is diminishing in several areas of ... more ABSTRACT Background: Although the role of electron microscopy is diminishing in several areas of adult pathology, it remains an essential tool for the study of pediatric liver biopsies. Methods: Clinical charts, histologic slides and EM materials of native liver biopsies from patients <1 year old (1991–2017) were reviewed. Results: 677 biopsies were performed on 353 males and 324 females. This study presents the concrete numbers for both the indications and the diseases, and describes the role of EM. EM was performed on 24.7% of liver biopsies and demonstrated key pathologic findings in 10 cases (6%), which led to the appropriate biochemical and/or genetic testing to confirm the diagnoses. The cases included five cases of glycogen storage disease with characteristic findings with cytoplasmic glycogen accumulation, two cases of mitochondrial disorder with pleomorphic mitochondria with crystalloid inclusions and one case each of Niemann-Pick Disease with abundant myelinosomes, Alpha-1 antitrypsin deficiency with deposits in the endoplasmic reticulum and infantile Refsum disease with trilamellar inclusions and lack of peroxisomes. In this study, we describe the detailed histologic and EM findings of each case . Conclusion: EM played an important screening and diagnostic role in the challenging cases and was also used to rule out detectable pathologic conditions.
JIMD reports, Jan 14, 2018
We describe two cases of neonatal onset interstitial lung disease eventually diagnosed as mucopol... more We describe two cases of neonatal onset interstitial lung disease eventually diagnosed as mucopolysaccharidosis type I (MPS I). In both cases, evaluation led to lung biopsy, pathology review, and identification of glycogen deposition. Pulmonary interstitial glycogenosis (PIG) was considered as a clinical diagnosis in case one; however, further review of electron microscopy (EM) was more consistent with MPS I rather than PIG. Both cases were confirmed to have MPS I by enzyme and molecular analysis. Neonatal interstitial lung disease is an atypical presentation for MPS I which is likely under-recognized. Diagnosis through clinical guidelines and a multidisciplinary approach had a major impact on patient management. The diagnosis of MPS I prompted timely initiation of enzyme replacement therapy (ERT) and the patients ultimately underwent hematopoietic stem cell transplantation (HSCT) to improve symptomatic outcomes. In addition to treatment, immediate precautionary recommendations were...
Microscopy and Microanalysis, 2013
Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indi... more Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.
JACC. Clinical electrophysiology, 2018
The purpose of this study was to assess the phenotype of Filamin C (FLNC) truncating variants in ... more The purpose of this study was to assess the phenotype of Filamin C (FLNC) truncating variants in dilated cardiomyopathy (DCM) and understand the mechanism leading to an arrhythmogenic phenotype. Mutations in FLNC are known to lead to skeletal myopathies, which may have an associated cardiac component. Recently, the clinical spectrum of FLNC mutations has been recognized to include a cardiac-restricted presentation in the absence of skeletal muscle involvement. A population of 319 U.S. and European DCM cardiomyopathy families was evaluated using whole-exome and targeted next-generation sequencing. FLNC truncation probands were identified and evaluated by clinical examination, histology, transmission electron microscopy, and immunohistochemistry. A total of 13 individuals in 7 families (2.2%) were found to harbor 6 different FLNC truncation variants (2 stopgain, 1 frameshift, and 3 splicing). Of the 13 FLNC truncation carriers, 11 (85%) had either ventricular arrhythmias or sudden car...
Molecular Genetics and Metabolism
Cardiac dysfunction is a common phenotypic manifestation of primary mitochondrial disease with mu... more Cardiac dysfunction is a common phenotypic manifestation of primary mitochondrial disease with multiple nuclear and mitochondrial DNA pathogenic variants as a cause, including disorders of mitochondrial translation. To date, five patients have been described with pathogenic variants in MRPL44, encoding the ml44 protein which is part of the large subunit of the mitochondrial ribosome (mitoribosome). Three presented as infants with hypertrophic cardiomyopathy, mild lactic acidosis, and easy fatigue and muscle weakness, whereas two presented in adolescence with myopathy and neurological symptoms. We describe two infants who presented with cardiomyopathy from the neonatal period, failure to thrive, hypoglycemia and in one infant lactic acidosis. A decompensation of the cardiac function in the first year resulted in demise. Exome sequencing identified compound heterozygous variants in the MRPL44 gene including the known pathogenic variant c.467 T > G and two novel pathogenic variants. We document a combined respiratory chain enzyme deficiency with emphasis on complex I and IV, affecting heart muscle tissue more than skeletal muscle or fibroblasts. We show this to be caused by reduced mitochondrial DNA encoded protein synthesis affecting all subunits, and resulting in dysfunction of complex I and IV assembly. The degree of oxidative phosphorylation dysfunction correlated with the impairment of mitochondrial protein synthesis due to different pathogenic variants. These functional studies allow for improved understanding of the pathogenesis of MRPL44-associated mitochondrial disorder.
American Journal of Respiratory Cell and Molecular Biology
European Respiratory Journal, 2020
Pulmonary interstitial glycogenosis (PIG) was first defined as a distinct neonatal interstitial l... more Pulmonary interstitial glycogenosis (PIG) was first defined as a distinct neonatal interstitial lung disease of unknown aetiology that presents in neonates and young infants with mild to severe hypoxic lung disease [1]. Characterised clinically by unexplained respiratory distress and cyanosis with an onset during early infancy, PIG was primarily defined by the presence of distinct and unusual-appearing cells contained within the interstitium that were characterised by a widened interstitium containing variable numbers of immature-appearing, polygonal-to-spindle shaped cells, which may contribute to impaired gas exchange. The most unique feature of PIG cells is the widespread presence of non-membrane bound, periodic acid-Schiff stain-positive, mono-particulate glycogen in the cytoplasm, for which the disease was named ("glycogenosis") [1]. By ultrastructure, PIG cells are considered primitive due to the presence of only sparse organelles and a lack of specific features that indicate differentiation towards any well-characterised pulmonary cell line, including lymphocytes or macrophages [1]. Observations from this landmark paper led to subsequent studies that further characterised PIG, using the presence of these novel and atypical appearing cells as the pathognomonic diagnostic hallmark [2-5]. Although initially considered a distinct disease, recent studies have identified histologic evidence of PIG in association with diverse cardiopulmonary disorders, including childhood interstitial lung disorders, congenital heart disease, bronchopulmonary dysplasia, congenital airway malformations, pulmonary hypertension, neuroendocrine cell hyperplasia of infancy and congenital lobar emphysema [2-5]. Long-term outcomes for infants with histologic findings of PIG are highly variable and may be linked with the severity of the underlying disease process associated with PIG histology; however, fatal cases have been reported even in the absence of other known primary diagnoses [2-5]. Clinical, imaging, bronchoscopic and genetic findings are not specific for PIG and diagnosis still requires lung biopsy.
.................................................................................................... more ............................................................................................................................ ii ACKNOWLEDGMENTS ....................................................................................................... iv TABLE OF CONTENTS ......................................................................................................... v LIST OF TABLES ................................................................................................................... vii LIST OF FIGURES ................................................................................................................. viii
Blood, 2019
Aging and chronic inflammation are independent risk factors for the development of atherothrombos... more Aging and chronic inflammation are independent risk factors for the development of atherothrombosis and cardiovascular disease. We hypothesized that aging-associated inflammation promotes the development of platelet hyperreactivity and increases thrombotic risk during aging. Functional platelet studies in aged-frail adults and old mice demonstrated that their platelets are hyperreactive and form larger thrombi. We identified tumor necrosis factor α (TNF-α) as the key aging-associated proinflammatory cytokine responsible for platelet hyperreactivity. We further showed that platelet hyperreactivity is neutralized by abrogating signaling through TNF-α receptors in vivo in a mouse model of aging. Analysis of the bone marrow compartments showed significant platelet-biased hematopoiesis in old mice reflected by increased megakaryocyte-committed progenitor cells, megakaryocyte ploidy status, and thrombocytosis. Single-cell RNA-sequencing analysis of native mouse megakaryocytes showed signi...
Journal of clinical pathology, 2015
A growing body of evidence suggests a role for altered epithelial barrier function in the pathoph... more A growing body of evidence suggests a role for altered epithelial barrier function in the pathophysiology of eosinophilic oesophagitis (EoE), but few have described the epithelial structure during inflammation. The purpose of this study was to define ultrastructural features of active, inactive EoE and control subject's oesophageal epithelia. We prospectively enrolled patients undergoing diagnostic upper endoscopy for evaluation of EoE. Mucosal pinch biopsies were obtained from the distal oesophagus and processed for routine histology and electron microscopic assessment. Clinical features of enrolled subjects were analysed and subjects were divided into four groups: normal, gastroesophageal reflux disease (GERD), inactive EoE and active EoE. Representative photomicrographs of the basal and superficial epithelia were reviewed for abnormalities. Desmosomes were quantified on the surface of epithelia three to four prickle-cell layers above the basal layer. Twenty-nine paediatric ca...
Microscopy and Microanalysis, 2017
Primary ciliary dyskinesia (PCD) is a congenital disease of the respiratory airways characterized... more Primary ciliary dyskinesia (PCD) is a congenital disease of the respiratory airways characterized by abnormal cilia structure and function. Clinical symptoms of the disease may include situs inversus, bronchiectasis, and chronic upper and lower airway infections. Transmission electron microscopic (TEM) evaluation of ciliary ultrastructure and genetic testing are the two most important components of the multimodal approach used in the diagnosis of this disease and are the only two techniques which can positively confirm a diagnosis in children under the age of 5 years old. Unlike the continuous search for PCD-associated genetic variants, few attempts been made to similarly improve the performance of the TEM analysis of ciliary biopsies. In this thesis, enhancement of the TEM examination by implementation of single-axis electron tomography for improved visualization of ciliary fine structure is explored. The analytic validity (technical performance of the test), clinical validity (power of the test to detect disease), and clinical utility (probability the test will result in improved patient outcomes) of the technique are evaluated through a multi-reader study comparing the 3D tomographic technique to conventional TEM. The study presents an analysis and discussion of data designed to thoroughly assess the role of single-axis 3D tomography in a clinical electron microscopic laboratory. The 3D iv technique is shown to be equal to conventional electron microscopy in recognizing disease. Readers report enhanced visualization of the inner dynein arms, a key ultrastructural feature within cilia for the identification of a specific PCD variant. The proportion of cases reported as inconclusive is reduced when comparing the 3D technique to the 2D technique, particularly in cases with suboptimal tissue available for evaluation. These findings have clinical relevance and prove the ability to perform single-axis 3D tomography can be a valued enhancement to the conventional 2D electron microscopic technique. The form and content of this abstract are approved. I recommend its publication. Approved: Mark. A. Lovell v DEDICATION This thesis is dedicated to my family. Each person listed on this page has a played a key role in the culmination of this project. My parents, Judy and Paul Wartchow, created an environment which nurtured a curious and independent young mind and allowed me to cultivate a lifelong interest in science. My wife Heidi has been motivating, understanding, and patient throughout the entire process. Our son, Connor, was a young man when this project began and has been a constant source of inspiration. Our daughters, Abigail and Shelby and their beautiful families, as well as my siblings, Keri and Josh, have provided me with continuous encouragement. I am grateful to each of you. vi ACKNOWLEDGEMENTS I am deeply indebted to many teachers, advisors, and colleagues who made this project possible. Dr. Josephine Taylor at Stephen F. Austin State University was the first to show me the amazing beauty of our world when viewed through the lens of an electron microscope. My colleagues in the Electron Microscopy Laboratory at Children's Hospital Colorado have provided valuable input and at times accepted additional responsibilities, allowing me to complete the Clinical Science graduate program while maintaining my position on our team. The contribution made by patients with Primary Ciliary Dyskinesia and their families is significant. The sacrifice of their time and energy to participate in a clinical study is admirable and allows the continued progress of our knowledge and understanding of this disease. Most importantly, I would like to acknowledge Dr. Gary Mierau. If there is one person with whom I should share any achievement I have enjoyed in my academic and professional career it is Gary. He has been a teacher, a mentor, and a friend for many years. I will never fully understand why he took a chance on me, but his dedication to my success has never wavered. I will be forever grateful for the knowledge and opportunities he has so generously and humbly provided.
Pediatric Pulmonology, 2018
Marijuana use has risen dramatically over the past decade. Over this same time period, pediatric ... more Marijuana use has risen dramatically over the past decade. Over this same time period, pediatric hospitals have seen an increase in presentation of adolescents with acute respiratory symptoms after recent marijuana inhalation. We report a case series of three adolescent males with significant findings of bilateral pulmonary nodules and ground glass opacities on chest imaging associated with recent marijuana inhalation. Lung biopsies in two of the three patients confirmed silica‐induced pneumoconiosis. The third patient was diagnosed with acute hypersensitivity pneumonitis without lung biopsy. Improvement in clinical symptoms and lung function testing were noted in two of three patients after marijuana inhalation cessation. This case series highlights the variety of severe pulmonary presentations in adolescents following recent marijuana inhalation. Future studies are required to assess whether these presenting pulmonary complications are from direct marijuana exposure or indirect associations with marijuana inhalation injuries.
Tanycytic ependymoma is the rarest variant of ependymoma and occurs primarily in the spinal cord.... more Tanycytic ependymoma is the rarest variant of ependymoma and occurs primarily in the spinal cord. Intracranial cases are even rarer. Only 9 ventricular and 5 subcortical tanycytic ependymoma have been reported in the literature. Amongst the 9 ventricular cases, only one tumor arose from the third ventricle. We report here another case of tanycytic ependymoma arising from the third ventricle completed with immunohistochemical, ul- trastructural, and molecular pathology study. The patient was a 44 year-old male who presented with headache, nausea and visual disturbances of a few months duration. Neuroradiological findings showed a well-defined mass arising from the posterolateral wall of third ventricle. Histologically the tumor was composed of monotonous spindle cells arranged in fascicles without definitive perivascular rosettes. The tumor cells were diffusely positive for glial fibrillary acidic protein and epithelial membrane antigen, showed faint immunoreactivity for synaptophysi...
Ultrastructural pathology
Zellweger spectrum disorders (ZSD) are rare autosomal recessive inherited metabolic disorders and... more Zellweger spectrum disorders (ZSD) are rare autosomal recessive inherited metabolic disorders and include severe (Zellweger syndrome) and milder phenotypes [neonatal adrenoleukodystrophy and infantile Refsum disease (IRD)]. ZSD are characterized by impaired peroxisomal functions and lack of peroxisomes detected by electron microscopy (EM). ZSD are caused by mutations in any of the 14 PEX genes. Patients with ZSD commonly demonstrate nonspecific hepatic symptoms within the first year, often without clinical suspicion of ZSD. Thus, recognition of pathologic findings in the liver is critical for the early diagnosis. We herein demonstrate the histologic and ultrastructural features in liver biopsies in the early and advanced phases from a 16-year-old male with IRD. The initial biopsy at 5 months of age showed a lack of peroxisomes by EM, and this finding played a critical role in the early diagnosis. In contrast, the second biopsy at 14 years of age, after long-term diet therapy, demons...
International journal of clinical and experimental pathology, 2015
Pediatric primary "small round blue cell" tumors in the CNS represent several entities,... more Pediatric primary "small round blue cell" tumors in the CNS represent several entities, some more common than others. Ewing sarcoma/peripheral primitive neuroectodermal tumor (ES/pPNET) is rare and must be distinguished from other tumors such as medulloblastoma [1, 2], atypical rhabdoid/teratoid tumor, ependymomal tumors, metastatic sarcomas, hematologic malignancies, and other mimics. Although therapy for ES/pPNET is effective, it brings severe side effects, including cardiac toxicity, making correct recognition important [3]. As small blue cell tumors look similar, diagnosis often depends on special stains, immunohistochemistry, and molecular techniques. While the combination of membranous immunohistochemical reactivity for CD99 with cytoplasmic glycogen provides effective screening, demonstration of characteristic translocations of EWSR1 (chromosome 22) or FUS (chromosome 16) by fluorescent in situ hybridization (FISH) can confirm the diagnosis. We are reporting three p...
International journal of clinical and experimental pathology, 2014
Tanycytic ependymoma is the rarest variant of ependymoma and occurs primarily in the spinal cord.... more Tanycytic ependymoma is the rarest variant of ependymoma and occurs primarily in the spinal cord. Intracranial cases are even rarer. Only 9 ventricular and 5 subcortical tanycytic ependymoma have been reported in the literature. Amongst the 9 ventricular cases, only one tumor arose from the third ventricle. We report here another case of tanycytic ependymoma arising from the third ventricle completed with immunohistochemical, ultrastructural, and molecular pathology study. The patient was a 44 year-old male who presented with headache, nausea and visual disturbances of a few months duration. Neuroradiological findings showed a well-defined mass arising from the posterolateral wall of third ventricle. Histologically the tumor was composed of monotonous spindle cells arranged in fascicles without definitive perivascular rosettes. The tumor cells were diffusely positive for glial fibrillary acidic protein and epithelial membrane antigen, showed faint immunoreactivity for synaptophysin ...
International Journal of Clinical and Experimental Pathology, 2016
Adult polyglucosan body disease (APBD) is a rare neurologic disease characterized clinically by p... more Adult polyglucosan body disease (APBD) is a rare neurologic disease characterized clinically by progressive upper and lower motor neuron dysfunction, neurogenic bladder, distal sensory loss, cerebellar dysfunction and dementia, while histologically featured by diffuse accumulation of polyglucosan bodies throughout the nervous system and in other organs. In some cases, this entity has been proved to be associated with reduced activity of glycogen branching enzyme and mutations of GBE1. We are reporting here a case of adult polyglucosan body disease with an atypical clinical presentation and imaging features that mimic a low-grade glioma. On enzymatic studies, there was reduced activity of glycogen branching enzyme in muscle but normal glycogen content. We also identified a heterozygous consensus splice site variant in intron 5 (c.691+2T>C) and a homozygous variant of unknown significance (c.-35dupC). Our case illustrates the possible clinical, imaging, pathologic, and genetic dive...
Ultrastructural Pathology
ABSTRACT Background: Although the role of electron microscopy is diminishing in several areas of ... more ABSTRACT Background: Although the role of electron microscopy is diminishing in several areas of adult pathology, it remains an essential tool for the study of pediatric liver biopsies. Methods: Clinical charts, histologic slides and EM materials of native liver biopsies from patients <1 year old (1991–2017) were reviewed. Results: 677 biopsies were performed on 353 males and 324 females. This study presents the concrete numbers for both the indications and the diseases, and describes the role of EM. EM was performed on 24.7% of liver biopsies and demonstrated key pathologic findings in 10 cases (6%), which led to the appropriate biochemical and/or genetic testing to confirm the diagnoses. The cases included five cases of glycogen storage disease with characteristic findings with cytoplasmic glycogen accumulation, two cases of mitochondrial disorder with pleomorphic mitochondria with crystalloid inclusions and one case each of Niemann-Pick Disease with abundant myelinosomes, Alpha-1 antitrypsin deficiency with deposits in the endoplasmic reticulum and infantile Refsum disease with trilamellar inclusions and lack of peroxisomes. In this study, we describe the detailed histologic and EM findings of each case . Conclusion: EM played an important screening and diagnostic role in the challenging cases and was also used to rule out detectable pathologic conditions.
JIMD reports, Jan 14, 2018
We describe two cases of neonatal onset interstitial lung disease eventually diagnosed as mucopol... more We describe two cases of neonatal onset interstitial lung disease eventually diagnosed as mucopolysaccharidosis type I (MPS I). In both cases, evaluation led to lung biopsy, pathology review, and identification of glycogen deposition. Pulmonary interstitial glycogenosis (PIG) was considered as a clinical diagnosis in case one; however, further review of electron microscopy (EM) was more consistent with MPS I rather than PIG. Both cases were confirmed to have MPS I by enzyme and molecular analysis. Neonatal interstitial lung disease is an atypical presentation for MPS I which is likely under-recognized. Diagnosis through clinical guidelines and a multidisciplinary approach had a major impact on patient management. The diagnosis of MPS I prompted timely initiation of enzyme replacement therapy (ERT) and the patients ultimately underwent hematopoietic stem cell transplantation (HSCT) to improve symptomatic outcomes. In addition to treatment, immediate precautionary recommendations were...