59 research outputs found
Independent Orbiter Assessment (IOA): Analysis of the hydraulics/water spray boiler subsystem
The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items (PCIs). To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results for the Orbiter Hydraulics/Water Spray Boiler Subsystem. The hydraulic system provides hydraulic power to gimbal the main engines, actuate the main engine propellant control valves, move the aerodynamic flight control surfaces, lower the landing gear, apply wheel brakes, steer the nosewheel, and dampen the external tank (ET) separation. Each hydraulic system has an associated water spray boiler which is used to cool the hydraulic fluid and APU lubricating oil. The IOA analysis process utilized available HYD/WSB hardware drawings, schematics and documents for defining hardware assemblies, components, and hardware items. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Of the 430 failure modes analyzed, 166 were determined to be PCIs
Evaluation of gastrointestinal transit in clinical practice: position paper of the American and European Neurogastroenterology and Motility Societies
Disorders of gastrointestinal (GI) transit and motility are common, and cause either delayed or accelerated transit through the stomach, small intestine or colon, and affect one or more regions. Assessment of regional and/or whole gut transit times can provide direct measurements and diagnostic information to explain the cause of symptoms, and plan therapy.Recently, several newer diagnostic tools have become available. The American and European Neurogastroenterology and Motility Societies undertook this review to provide guidelines on the indications and optimal methods for the use of transit measurements in clinical practice. This was based on evidence of validation including performance characteristics, clinical significance, and strengths of various techniques. The tests include measurements of: gastric emptying with scintigraphy, wireless motility capsule, and 13 C breath tests; small bowel transit with breath tests, scintigraphy, and wireless motility capsule; and colonic transit with radioopaque markers, wireless motility capsule, and scintigraphy. Based on the evidence, consensus recommendations are provided for each technique and for the evaluations of regional and whole gut transit. In summary, tests of gastrointestinal transit are available and useful in the evaluation of patients with symptoms suggestive of gastrointestinal dysmotility, since they can provide objective diagnosis and a rational approach to patient management.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79321/1/j.1365-2982.2010.01612.x.pd
Treatment of gastroparesis: a multidisciplinary clinical review
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75594/1/j.1365-2982.2006.00760.x.pd
Transcriptomic signatures reveal immune dysregulation in human diabetic and idiopathic gastroparesis
Abstract
Background
Cellular changes described in human gastroparesis have revealed a role for immune dysregulation, however, a mechanistic understanding of human gastroparesis and the signaling pathways involved are still unclear.
Methods
Diabetic gastroparetics, diabetic non-gastroparetic controls, idiopathic gastroparetics and non-diabetic non-gastroparetic controls underwent full-thickness gastric body biopsies. Deep RNA sequencing was performed and pathway analysis of differentially expressed transcripts was done using Ingenuity®. A subset of differentially expressed genes in diabetic gastroparesis was validated in a separate cohort using QT-PCR.
Results
111 genes were differentially expressed in diabetic gastroparesis and 181 in idiopathic gastroparesis with a log2fold difference of | ≥ 2| and false detection rate (FDR) < 5%. Top canonical pathways in diabetic gastroparesis included genes involved with macrophages, fibroblasts and endothelial cells in rheumatoid arthritis, osteoarthritis pathway and differential regulation of cytokine production in macrophages and T helper cells by IL-17A and IL-17F. Top canonical pathways in idiopathic gastroparesis included genes involved in granulocyte adhesion and diapedesis, agranulocyte adhesion and diapedesis, and role of macrophages, fibroblasts and endothelial cells in rheumatoid arthritis. Sixty-five differentially expressed genes (log2fold difference | ≥ 2|, FDR < 5%) were common in both diabetic and idiopathic gastroparesis with genes in the top 5 canonical pathways associated with immune signaling. 4/5 highly differentially expressed genes (SGK1, APOLD1, CXCR4, CXCL2, and FOS) in diabetic gastroparesis were validated in a separate cohort of patients using RT-PCR. Immune profile analysis revealed that genes associated with M1 (pro inflammatory) macrophages were enriched in tissues from idiopathic gastroparesis tissues compared to controls (p < 0.05).
Conclusions
Diabetic and idiopathic gastroparesis have both unique and overlapping transcriptomic signatures. Innate immune signaling likely plays a central role in pathogenesis of human gastroparesis.https://deepblue.lib.umich.edu/bitstream/2027.42/145193/1/12920_2018_Article_379.pd
Transcriptomic signatures reveal immune dysregulation in human diabetic and idiopathic gastroparesis
Abstract
Background
Cellular changes described in human gastroparesis have revealed a role for immune dysregulation, however, a mechanistic understanding of human gastroparesis and the signaling pathways involved are still unclear.
Methods
Diabetic gastroparetics, diabetic non-gastroparetic controls, idiopathic gastroparetics and non-diabetic non-gastroparetic controls underwent full-thickness gastric body biopsies. Deep RNA sequencing was performed and pathway analysis of differentially expressed transcripts was done using Ingenuity®. A subset of differentially expressed genes in diabetic gastroparesis was validated in a separate cohort using QT-PCR.
Results
111 genes were differentially expressed in diabetic gastroparesis and 181 in idiopathic gastroparesis with a log2fold difference of | ≥ 2| and false detection rate (FDR) < 5%. Top canonical pathways in diabetic gastroparesis included genes involved with macrophages, fibroblasts and endothelial cells in rheumatoid arthritis, osteoarthritis pathway and differential regulation of cytokine production in macrophages and T helper cells by IL-17A and IL-17F. Top canonical pathways in idiopathic gastroparesis included genes involved in granulocyte adhesion and diapedesis, agranulocyte adhesion and diapedesis, and role of macrophages, fibroblasts and endothelial cells in rheumatoid arthritis. Sixty-five differentially expressed genes (log2fold difference | ≥ 2|, FDR < 5%) were common in both diabetic and idiopathic gastroparesis with genes in the top 5 canonical pathways associated with immune signaling. 4/5 highly differentially expressed genes (SGK1, APOLD1, CXCR4, CXCL2, and FOS) in diabetic gastroparesis were validated in a separate cohort of patients using RT-PCR. Immune profile analysis revealed that genes associated with M1 (pro inflammatory) macrophages were enriched in tissues from idiopathic gastroparesis tissues compared to controls (p < 0.05).
Conclusions
Diabetic and idiopathic gastroparesis have both unique and overlapping transcriptomic signatures. Innate immune signaling likely plays a central role in pathogenesis of human gastroparesis.https://deepblue.lib.umich.edu/bitstream/2027.42/145193/1/12920_2018_Article_379.pd
Electrogastrography: a document prepared by the gastric section of the American Motility Society Clinical GI Motility Testing Task Force
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71439/1/j.1365-2982.2003.00396.x.pd
The assessment of regional gut transit times in healthy controls and patients with gastroparesis using wireless motility technology
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71453/1/j.1365-2036.2009.04162.x.pd
W1313 Wireless Capsule Quantification of Region-Specific Gastrocolonic Response and Sleep Inhibition of Colon Motor Activity in Unprepared Colons of Humans with Normal Colon Transit
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