Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0007095 (carcinoid)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The pulmonary neuroendocrine cell (PNEC) system consists of solitary cells and distinctive cell clusters termed neuroepithelial bodies (NEB) localized in the airway epithelium. PNEC/NEB express a variety of bioactive substances, including amine (serotonin, 5HT) and neuropeptides. We have previously shown that NEB cells are O(2) sensors expressing nicotinamide adenine diphosphate oxidase complex and O(2) sensitive K(+) channel. Recently, we demonstrated expression of functional cystic fibrosis transmembrane conductance regulator (CFTR) and Cl(-) conductances in NEB cells of rabbit neonatal lung. Because PNEC/NEB are sparsely distributed and difficult to study in native lung, we investigated small-cell lung carcinoma (SCLC) and carcinoid tumor cell lines (tumor counterparts of normal PNEC/NEB) as models for PNEC/NEB. SCLC (H146, H345) and carcinoid (H727) cell lines express neuroendocrine cell markers, including chromogranin A, neural cell adhesion molecule (N-CAM), 5HT, and tryptophan hydroxylase. We report that H146, H345, and H727 express CFTR messenger RNA (reverse transcription polymerase chain reaction) and protein (immunoblotting) and possess functional CFTR Cl(-) conductance, demonstrated by an iodide efflux assay inhibitable by transfection with antisense CFTR. Using an immunoassay to quantitate 5HT secretion, we also show that downregulation of CFTR abolishes hypoxia-induced 5HT release, and reduces secretory response to high potassium. Our findings suggest that CFTR may modulate neurosecretory activity of PNEC/NEB possessing O(2) sensor function. We propose that these tumor cell lines may be useful models for investigating the role of CFTR in PNEC/NEB functions in health and disease.
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PMID:Cystic fibrosis transmembrane conductance regulator modulates neurosecretory function in pulmonary neuroendocrine cell-related tumor cell line models. 1239 14

Vitamin B-12 deficiency, most commonly due to pernicious anemia, can cause intramedullary hemolysis. The pathogenesis is thought to be due to increased membrane rigidity and reduced red blood cell elasticity, which predisposes the patient to hemolysis and microangiopathic hemolytic anemia. In this article, we discuss a Russian engineer who worked aboard a petroleum tanker that presented from his ship with profound B-12 deficiency, microangiopathic anemia, elevated lactate dehydrogenase levels, low haptoglobin, and reticulocyte count in the setting of normal renal and neurologic function. The patient traveled around the world seven months of the year for work and had occupational exposure to fluorinated hydrocarbons. Extensive diagnostic work-up, including endoscopic biopsy, and a radio-labeled octreotide scan was performed. The patient was found to have autoimmune gastritis and a gastric carcinoid tumor. With assistance from his global health insurance provider and a local hospital near his hometown in Russia, care was coordinated to be transitioned there with a plan for repeat endoscopy and mapping biopsies to determine the extent of his tumor burden. This study adds to the now growing base of literature describing this atypical presentation of pernicious anemia with normal neurologic function and underscores the importance of screening for B-12 deficiency in these patients. It also highlights the increased risk of gastric carcinoids in patients with autoimmune gastritis. With the collaboration of different medical specialists, the full gamut of medical technology was utilized in the care of the patient. This included in vitro diagnostics, advanced endoscopic tools, pathology, and radio-isotope based imaging studies.
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PMID:Hemolytic Anemia and Gastric Carcinoid in a Russian Seafarer: Highlighting the Role of Diagnostic Technologies in Modern Clinical Practice. 3025 11