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Biomedical subjects

Ernest Cutz

Publications and source records attributed to Ernest Cutz.

At least 19 recordsLinked to original sources

Activated mucosal mast cells differentiate eosinophilic (allergic) esophagitis from gastroesophageal reflux disease.

OBJECTIVES: To evaluate the utility of activated mucosal mast cells (MC) in the differential diagnosis of eosinophilic esophagitis (EE) and gastroesophageal reflux disease (GERD). METHODS: Intraepithelial eosinophils and MC were quantified in esophageal biopsies from 25 children with EE, 22 children with GERD and 22 controls. MCs were identified by immunohistochemistry for MC tryptase, whereas MC activation status was evaluated by immunohistochemistry for immunoglobulin E (IgE) and by electron microscopy. RESULTS: Esophageal biopsies from patients with EE showed higher intraepithelial eosinophil counts (55 +/- 27.5 vs 6.9 +/- 9.7, P < 0.0001) and MC counts (26.3 +/- 12.7 vs 7.8 +/- 8.9, P < 0.0001) than those from patients with GERD. Almost all EE biopsies (24 of 25 patients; 96%) contained IgE-bearing cells compared with 9 of 22 (41%) GERD biopsies (P < 0.001). GERD biopsies with intraepithelial eosinophil counts >7/high-power field (suggesting an allergic component) contained IgE-bearing cells in 6 of 7 (86%) cases compared to 3 of 15 (20%) cases with eosinophil counts <7/h.p.f (P < 0.01). No intraepithelial eosinophils, MC or IgE-positive cells were present in controls. Electron microscopy confirmed the presence of intraepithelial MC and changes in cytoplasmic granules indicative of MC and eosinophil activation. CONCLUSIONS: Intraepithelial MC counts and IgE-bearing cells may help to differentiate EE and GERD and to define a subset of GERD patients in which an allergic component is present. The findings support a role for a MC-mediated hypersensitivity reaction in the pathogenesis of EE.

Adolescent↗

Novel mitochondrial DNA mutations associated with myopathy, cardiomyopathy, renal failure, and deafness.

Patients with mitochondrial disease usually manifest multisystemic dysfunction with a broad clinical spectrum. When the tests for common mitochondrial DNA (mtDNA) point mutations are negative and the mtDNA defects are still hypothesized, it is necessary to screen the entire mitochondrial genome for unknown mutations in order to confirm the diagnosis. We report an 8-year-old girl who had a long history of ragged-red fiber myopathy, short stature, and deafness, who ultimately developed renal failure and fatal cardiac dysfunction. Respiratory chain enzyme analysis on muscle biopsy revealed deficiency in complexes I, II/III, and IV. Whole mitochondrial genome sequencing analysis was performed. Three novel changes: homoplasmic 15458T > C and 15519T > C in cytochrome b, and a near homoplasmic 5783G > A in tRNA(cys), were found in the proband in various tissues. Her mother and asymptomatic sibling also carry the two homoplasmic mutations and the heteroplasmic 5783G > A mutation in blood, hair follicles, and buccal cells, at lower percentage. The 5783G > A mutation occurs at the T arm of tRNA(cys), resulting in the disruption of the stem structure, which may reduce the stability of the tRNA. 15458T > C changes an amino acid serine to proline at a conserved alpha-helix, which may force the helix to bend. These two mutations may have pathogenic significance. This case emphasizes the importance of pursuing more extensive mutational analysis of mtDNA in the absence of common mtDNA point mutations or large deletions, when there is a high suspicion of a mitochondrial disorder.

Abnormalities, Multiple↗

Pulmonary neuroendocrine cells, airway innervation, and smooth muscle are altered in Cftr null mice.

The amine- and peptide-producing pulmonary neuroendocrine cells (PNEC) are widely distributed within the airway mucosa of mammalian lung as solitary cells and innervated clusters, neuroepithelial bodies (NEB), which function as airway O2 sensors. These cells express Cftr and hence could play a role in the pathophysiology of cystic fibrosis (CF) lung disease. We performed confocal microscopy and morphometric analysis on lung sections from Cftr-/- (null), Cftr+/+, and Cftr+/- (control) mice at developmental stages E20, P5, P9, and P30 to determine the distribution, frequency, and innervation of PNEC/NEB, innervation and cell mass of airway smooth muscle, and neuromuscular junctions using synaptic vesicle protein 2, smooth muscle actin, and synaptophysin markers, respectively. The mean number of PNEC/NEB in Cftr-/- mice was significantly reduced compared with control mice at E20, whereas comparable or increased numbers were observed postnatally. NEB cells in Cftr null mice showed a significant reduction in intracorpuscular nerve endings compared with control mice, which is consistent with an intrinsic abnormality of the PNEC system. The airways of Cftr-/- mice showed reduced density (approximately 20-30%) of smooth muscle innervation, decreased mean airway smooth muscle mass (approximately 35%), and reduced density (approximately 20%) of nerve endings compared with control mice. We conclude that the airways of Cftr-/- mice exhibit heretofore unappreciated structural alterations affecting cellular and neural components of the PNEC system and airway smooth muscle and its innervation resulting in blunted O2 sensing and reduced airway tonus. Cftr could play a role in the development of the PNEC system, lung innervation, and airway smooth muscle.

Animals↗

Mechanical stretch-induced serotonin release from pulmonary neuroendocrine cells: implications for lung development.

Pulmonary neuroendocrine cells (PNEC) produce amine (serotonin, 5-HT) and peptides (e.g., bombesin, calcitonin) with growth factor-like properties and are thought to play an important role in lung development. Because physical forces are essential for lung growth and development, we investigated the effects of mechanical strain on 5-HT release in PNEC freshly isolated from rabbit fetal lung and in the PNEC-related tumor H727 cell line. Cultures exposed to sinusoidal cyclic stretch showed a significant 5-HT release inhibitable with gadolinium chloride (10 nM), a blocker of mechanosensitive channels. In contrast to hypoxia (Po2 approximately 20 mmHg), stretch-induced 5-HT release was not affected by Ca2+-free medium or nifedipine (50 microM), excluding the exocytic pathway. In H727 cells, stretch failed to release calcitonin, a peptide stored within dense core vesicles (DCV), whereas hypoxia caused massive calcitonin release. 5-HT released by mechanical stretch is derived predominantly from the cytoplasmic pool, because it is rapid ( approximately 5 min) and is releasable from early (20 days of gestation) fetal PNEC containing few DCV. Both mechanical stretch and hypoxia upregulated expression of tryptophan hydroxylase, the rate-limiting enzyme of 5-HT synthesis. We conclude that mechanical strain is an important physiological stimulus for the release of 5-HT from PNEC via mechanosensitive channels with potential effects on lung development and resorption of lung fluid at the time of birth.

Animals↗

Lineage development in a patient without goblet, paneth, and enteroendocrine cells: a clue for intestinal epithelial differentiation.

We report a patient who presented with severe enterocolitis and apparent absence of Paneth, goblet, and enteroendocrine lineages from the small bowel and colon. The absorptive enterocyte seemed to be normal morphologically and functionally. Because normal enterocytes were present, we hypothesized that this patient had a developmental block in the differentiation of a common stem cell precursor for Paneth, goblet, and neuroendocrine lineages. By using antibodies to protein markers of each cell line, including some that are expressed early in the differentiation process, we aimed to study lineage development in this patient. From our data, we surmise that there may be a two-step process in lineage commitment. The stem cell may commit to an absorptive cell or a granule-containing cell. The daughter cell that is committed to the granule lineage then further commits to a goblet, enteroendocrine, or Paneth cell lineage.

Adolescent↗

Alveolar capillary dysplasia: a six-year single center experience.

UNLABELLED: Alveolar capillary dysplasia is a fatal disorder of the lung that requires lung biopsy for diagnosis. We reviewed the course of patients with alveolar capillary dysplasia following implementation of an early lung biopsy strategy between 1997-2002. We performed immunohisto-chemical studies on all tissue specimens. We diagnosed 7 cases of alveolar capillary dysplasia. We diagnosed 6/7 cases of alveolar capillary dysplasia pre-mortem by early lung biopsy. Median time between admission and lung biopsy was 6.5 days. All patients survived lung biopsy but died following withdrawal of active therapy after confirmation of the tissue diagnosis. In 1 patient we demonstrated histological findings of alveolar capillary dysplasia and congenital acinar dysplasia. Two patients were first cousins. One patient underwent pulmonary angiography with rapid filling of the pulmonary veins before passage of contrast through the capillary bed. Five patients were supported with extracorporeal membrane oxygenation and 2/5 patients survived decannulation. During the same period 8 patients required ECMO for acute hypoxic respiratory failure. Four out of 8 were diagnosed with alveolar capillary dysplasia. CONCLUSIONS: Early lung biopsy was performed with low risk and high diagnostic yield for alveolar capillary dysplasia. Alveolar capillary dysplasia occurs frequently in neonates who require ECMO support for refractory pulmonary hypertension. We have added an additional familial case and suggest a novel angiographic finding.

Biopsy↗

Nosocomial transmission of congenital tuberculosis in a neonatal intensive care unit.

Congenital tuberculosis is uncommon, and nosocomial transmission from a congenitally infected infant to another infant has not been reported in the English literature. We report an investigation of 2 infants with tuberculosis who were cared for in the same neonatal intensive care unit. Isolates from both infants were genetically indistinguishable. Transmission between the 2 infants was likely due to contaminated respiratory equipment.

Cross Infection↗

Expression of epithelial sodium channel alpha-subunit mRNAs with alternative 5'-untranslated regions in the developing human lung.

In preparation for birth, lung epithelia must switch from net fluid secretion, required for lung development, to net absorption, which prepares the lungs for postnatal gas exchange. The apical membrane amiloride-sensitive epithelial Na channel (ENaC) is the rate-limiting step for Na+ and fluid absorption. Expression of alpha-ENaC mRNA has been detected in human lung as early as the embryonic stage of development. However, humans express multiple transcripts for alpha-ENaC, containing differing 5'-untranslated regions (UTR) with unknown effects on protein translation, and different ontogenies for individual transcripts could provide a novel mechanism for developmental regulation of ENaC function. To assess the relative expression of the two most abundant alpha-ENaC transcripts (alpha-ENaC1 and alpha-ENaC2) during lung development, we performed nonradioactive in situ hybridization using probes specific to the alternative 5'-UTRs. Both transcripts were expressed throughout intrauterine lung development (8 to 40 wk gestation), and expression was localized to the surface epithelial cells of the conductive and respiratory airways in both ciliated cells and nonciliated Clara cells. alpha-ENaC mRNA expression was also identified in the serous cells of the submucosal glands surrounding the proximal airways. In the mature prenatal lung, subsets of alveolar type II (ATII) cells expressed one or both of the alpha-ENaC transcripts. Our observations demonstrate that a developmentally regulated switch between alpha-ENaC 5'-UTR variants is not the trigger by which the developing human lung becomes a fluid-absorbing organ at birth, that individual ATII cells express neither, one, or both of the alpha-ENaC transcripts, and that the overall expression is linked to epithelial cell differentiation and lung maturation.

5' Untranslated Regions↗

Gastrointestinal cancers and neurofibromatosis type 1 features in children with a germline homozygous MLH1 mutation.

Heterozygous germline DNA mismatch repair gene mutations are typically associated with hereditary nonpolyposis colorectal cancer. The molecular hallmark of this syndrome is high-frequency microsatellite instability in the tumors. Rare childhood cases with homozygous or compound heterozygous DNA mismatch repair gene mutations have a described predisposition to leukemia, lymphoma, and brain tumors but not to gastrointestinal cancer. We have now characterized a family in which 2 children with a homozygous germline DNA mismatch repair gene mutation developed early-onset gastrointestinal cancers. The 11-year-old proband had café-au-lait macules and developed metastatic duodenal adenocarcinoma that arose in a tubulovillous adenoma. His 9-year-old sister with café-au-lait macules and axillary freckling presented with malignant colon polyps. A 6-year-old sister with café-au-lait macules, hairy nevi, and a plexiform neurofibroma of the tongue has no malignancies to date. The family history did not fulfill the Amsterdam criteria for hereditary nonpolyposis colorectal cancer, but 2 relatives in their 60s had gastric cancer and colorectal cancer, whereas the parents, who are first cousins, remain cancer free. The proband's metastatic duodenal cancer and his sister's malignant colon polyps had high-frequency microsatellite instability but had detectable MLH1, MSH2, and MSH6 proteins by immunohistochemistry. Because some germline DNA mismatch repair gene deficiencies are associated with apparently intact immunohistochemical DNA mismatch repair gene expression in tumors, we proceeded to DNA sequencing, which showed that all 3 children had a germline homozygous MLH1 missense mutation (exon 18, codon 687, CGG-->TGG), whereas both parents were heterozygous for this mutation.

Adaptor Proteins, Signal Transducing↗

Neonatal enteropathies: defining the causes of protracted diarrhea of infancy.

The underlying causes of chronic diarrhea beginning early in life are increasingly well defined. Infectious and post-infectious enteropathies and food sensitive/allergic enteropathy account for the majority of cases. Recent attention has focused on characterizing defined entities, which cause protracted diarrhea in infants and young children. Disorders of intestinal ion transport usually present at birth following a pregnancy complicated by polyhydramnios. Intestinal mucosal biopsies show normal architect with intact villus-crypt axis. Neonatal enteropathies, by contrast, are characterized by blunting of the villi. These include microvillus inclusion disease, tufting enteropathy, autoimmune enteropathy and IPEX syndrome - and it is these conditions that are the subject of the current review.

Autoimmune Diseases↗

Colonic expression of MUC2, MUC5AC, and TFF1 in inflammatory bowel disease in children.

BACKGROUND: The quantity and quality of mucins are affected in inflammatory bowel disease (IBD) both because of a reduction in the number of goblet cells and a decrease in the number of sugar residues per oligosaccharide side chain. Alteration in the types of mucins and aberrant location may contribute to the underlying pathology by affecting the mucus barrier function or may instead be a response to inflammation. The authors used the periodic acid-Schiff/Alcian blue stain to distinguish neutral and acidic mucins, and used specific antibodies to the mature goblet cell mucin MUC2, MUC2 core antigen, foveolar cell mucin MUC5AC, and gastric trefoil factor (TFF1), to characterize their presence and distribution in colonic tissue sections from patients with IBD. RESULTS: Both core and mature MUC2 were expressed in all colonic goblet cells from patients with ulcerative colitis (UC) and Crohn disease and from healthy controls. MUC5AC and TFF1, which are not normally expressed by colonic tissue, also were expressed in scattered goblet cells, coexpressing with MUC2. In areas of goblet cell depletion, MUC2 was present in cytoplasmic granules of flattened, cuboidal, nongoblet-cell-like surface cells. The staining was more intense and homogenous with the MUC2 core antibody, suggesting expression of relatively immature mucin. Some of these cells also coexpressed MUC5AC but to a lesser extent. These findings are not unique to IBD but were also found in other types of intestinal inflammation. CONCLUSION: The study confirms earlier observations that MUC2 is the major colonic mucin in IBD. It appears in two forms: mature MUC2 in goblet cells and immature MUC2 especially in secretory granules of cells that are not phenotypically goblet cells. MUC5AC and TFF1 expression in goblet cells is common in IBD and other inflammatory conditions of the colon. These changes may represent a nonspecific repair function of the colon cells to compensate for damage to barrier function.

Adolescent↗

Innervation of pulmonary neuroendocrine cells and neuroepithelial bodies in developing rabbit lung.

We investigated the development of innervation of the pulmonary neuroendocrine cell (PNEC) system composed of single cells and organoid cell clusters, neuroepithelial bodies (NEB) in rabbit fetal and neonatal lungs. To visualize the nerve fibers and their contacts with PNECs/NEBs, we used confocal microscopy and multilabel immunohistochemistry (IHC) with pan-neural marker, synaptic vesicle protein 2 (SV2), and serotonin (5-HT) as markers for PNECs/NEBs, and smooth muscle actin or cytokeratin to identify airway landmarks. The numbers and distribution of PNEC/NEB at different stages of lung development (E16, 18, 21, 26, and P2) and the density of innervation were quantified. First PNECs immunoreactive for 5-HT were identified in primitive airway epithelium at E18 as single cells or as small cell clusters with or without early nerve contacts. At E21 a significant increase in the number of PNECs with formation of early innervated NEB corpuscules was observed. The overall numbers of PNECs/NEBs and the density of mucosal, submucosal, and intercorpuscular innervation increased with progressing gestation and peaked postnatally (P2). At term, the majority of NEBs and single PNECs within airway mucosa possessed neural contacts. Such an extensive and complex innervation of the PNEC system indicates a multifunctional role in developing lung and during neonatal adaptation.

Animals↗

Sudden infant death syndrome and unclassified sudden infant deaths: a definitional and diagnostic approach.

The definition of sudden infant death syndrome (SIDS) originally appeared in 1969 and was modified 2 decades later. During the following 15 years, an enormous amount of additional information has emerged, justifying additional refinement of the definition of SIDS to incorporate epidemiologic features, risk factors, pathologic features, and ancillary test findings. An expert panel of pediatric and forensic pathologists and pediatricians considered these issues and developed a new general definition of SIDS for administrative and vital statistics purposes. The new definition was then stratified to facilitate research into sudden infant death. Another category, defined as unclassified sudden infant deaths, was introduced for cases that do not meet the criteria for a diagnosis of SIDS and for which alternative diagnoses of natural or unnatural conditions were equivocal. It is anticipated that these new definitions will be modified in the future to accommodate new understanding of SIDS and sudden infant death.

Humans↗

Expression of functional nicotinic acetylcholine receptors in neuroepithelial bodies of neonatal hamster lung.

Pulmonary neuroepithelial bodies (NEB) are presumed airway chemoreceptors involved in respiratory control, especially in the neonate. Nicotine is known to affect both lung development and control of breathing. We report expression of functional nicotinic acetylcholine receptors (nAChR) in NEB cells of neonatal hamster lung using a combination of morphological and electrophysiological techniques. Nonisotopic in situ hybridization method was used to localize mRNA for the beta 2-subunit of nAChR in NEB cells. Double-label immunofluorescence confirmed expression of alpha 4-, alpha 7-, and beta 2-subunits of nAChR in NEB cells. The electrophysiological characteristics of nAChR in NEB cells were studied using the whole cell patch-clamp technique on fresh lung slices. Application of nicotine ( approximately 0.1-100 microM) evoked inward currents that were concentration dependent (EC50 = 3.8 microM; Hill coefficient = 1.1). ACh (100 microM) and nicotine (50 microM) produced two types of currents. In most NEB cells, nicotine-induced currents had a single desensitizing component that was blocked by mecamylamine (50 microM) and dihydro-beta-erythroidine (50 microM). In some NEB cells, nicotine-induced current had two components, with fast- and slow-desensitizing kinetics. The fast component was selectively blocked by methyllcaconitine (MLA, 10 nM), whereas both components were inhibited by mecamylamine. Choline (0.5 mM) also induced an inward current that was abolished by 10 nM MLA. These studies suggest that NEB cells in neonatal hamster lung express functional heteromeric alpha 3 beta 2, alpha 4 beta 2, and alpha 7 nAChR and that cholinergic mechanisms could modulate NEB chemoreceptor function under normal and pathological conditions.

Acetylcholine↗

Expression of Hoxb-5 during human lung development and in congenital lung malformations.

BACKGROUND: We have previously shown that the Hox gene Hoxb-5 is necessary for normal mouse lung branching morphogenesis. Abnormal Hoxb-5 regulation causes specific alterations in airway branching. We hypothesized that Hoxb-5 is similarly involved in human lung branching morphogenesis, and is abnormally expressed in bronchopulmonary sequestration (BPS) and congenital cystic adenomatoid malformation (CCAM), both of which are congenital lung malformations with abnormal airway development. METHODS: The temporal, spatial, and cellular expression of the Hoxb-5 protein was evaluated in normal human lung and BPS and CCAM tissue using Western blot analysis and immunocytochemistry. RESULTS: The expression of Hoxb-5 during human lung development showed strong similarities to that during mouse lung development. Western blots showed high Hoxb-5 protein levels in the pseudoglandular period (PSG), decreased but sustained levels in the canalicular period (CAN), and negligible levels during the alveolar period (ALV). Immunocytochemistry showed Hoxb-5 protein expression in mesenchymal cells around branching airways in the pseuodglandular period, subepithelial fibroblast localization (especially at airway branch points) in the CAN and minimal expression in the ALV. In BPS and CCAM tissue, Hoxb-5 protein levels were increased compared to age- and developmentally-matched lung tissue, and were more similar to the PSG and CAN with Hoxb-5-positive cells in mesenchyme surrounding abnormally branched airways. CONCLUSIONS: Hoxb-5 expression during human lung branching morphogenesis, which is similar to that observed in mouse lung development, indicates that it plays a role in controlling airway patterning. This notion is supported by results from BPS and CCAM tissue, in which Hoxb-5 is maintained in a manner typical of an earlier developmental stage and is associated with development of abnormal lung tissue.

Bronchopulmonary Sequestration↗