- Email: [email protected]
298 Altered Expression of Contractile Regulatory Proteins in Patients With Refractory Idiopathic Gastroparesis
gastroparesis. The majority of cases of gastroparesis are either idiopathic or a result of complications of diabetes. To date there has been no comprehensive analysis of the pathological and molecular changes that occur in idiopathic gastroparesis patients. Based largely on data obtained from rodent models it has been proposed that diabetic gastroparesis may in part be caused by loss of cKit (CD117) positive ICCs. Aims: 1) To determine if changes in contractile or regulatory proteins could be contributing to impaired contractility in patients with idiopathic gastroparesis. 2) To determine if loss of cKit positive ICCs is also a feature of idiopathic gastroparesis. Methods: A prospective clinical, pathological and molecular gastrointestinal neuromuscular registry was established. Informed consents were obtained and full thickness antral biopsy samples were collected from 9 non-diabetic patients (undergoing bariatric weight loss surgery) that exhibited no symptoms of gastroparesis and from 10 non-diabetic subjects with idiopathic gastroparesis refractory to treatment. A portion of the biopsy was used for pathological analysis, the remainder was collected in RNAlater and the smooth muscle layers were dissected free of submucosal and mucosal layers. mRNA was isolated from the smooth muscle and analyzed by quantitative reverse transcriptase (RT)PCR. Results: Our analysis revealed that smooth muscle from idiopathic gastroparesis subjects had decreased expression of mRNAs encoding contractile regulatory proteins, such as smooth muscle myosin heavy chain and smooth muscle myosin light chain kinase. Conversely, these subjects exhibited greater than 3-fold higher levels of p21-activated kinase (PAK1) as compared to controls. No change in cKit expression was observed in subjects with idiopathic gastroparesis as compared to control subjects. Conclusions: Our findings suggest that idiopathic gastroparesis is associated with decreased contractile protein expression. Moreover, as pathologically elevated PAK1 expression has been associated with increased myosin light chain phosphatase activity, this would be expected to further attenuate contractility. Unchanged cKit expression in samples from idiopathic gastroparesis subjects would suggest that decreased expression of cKit and loss of ICCs may be a unique feature of diabetic gastroparesis. Together these studies suggest that changes in contractile regulatory proteins likely contribute to the dysmotility seen in patients with idiopathic gastroparesis.
Effectiveness of Gastric Electrical Stimulation in Gastroparesis: Results From a Large Prospectively Collected Database of a National Gastroparesis Registry Thomas L. Abell, Richard W. McCallum, Kevin P. May, Laura Wilson, Henry P. Parkman, William L. Hasler, Kenneth L. Koch, William J. Snape, John O. Clarke, Linda Anh B. Nguyen, Irene Sarosiek, Gianrico Farrugia, Jorge Calles-Escandon, James Tonascia, Linda A. Lee, Frank A. Hamilton, Pankaj J. Pasricha Introduction. The use of gastric electrical stimulation (GES) for treating gastroparesis is controversial, despite several randomized controlled trials. Given difficulties in conducting placebo-controlled trials for surgical procedures, we utilitzed prospectively collected data from patients enrolled in the Gastroparesis Clinical Research Consortium (GPCRC) registries, some with GES implanted, to evaluate its effectiveness. Methods. We studied idiopathic or diabetic gastroparesis or gastroparesis-like symptoms patients followed in the NIDDK GpCRC who had completed at least 48 week follow-up, with or without insertion of a GES device at any time during this period. Patients were seen every 16 weeks and treated by physicians at 6 academic medical centers. Prospectively collected registry data included detailed histories, validated symptom questionnaires, psychological distress measures and gastric emptying results. Improvement at 48 weeks was evaluated by: absolute change, any improvement, and improvement ‡ 1-point drop, in the Gastroparesis Cardinal Symptom Index (GCSI). Logistic regression compared the odds of GES improvement, whether or not a GES device was implanted, and was reported by unadjusted, adjusted and propensity-adjusted models. Results. Of a total of 688 patients, 54 patients were excluded because GES had been in place at enrollment in the registry. Of the remaining 634, 92 (14.5%) had GES placed after registry enrollment; 48-week data from these patients were compared to 48-week data from the remainder (control group) who never had GES. 38% of patients with GES were diabetic and 54% idiopathic, proportions not different from those without GES. Patients with GES had more delayed gastric emptying at 4 hours (30.9 vs. 21.8; p=0.002), were sicker (46.7% graded as having severe gastroparesis vs. 20.9% in the controls); p<0.001, with worse PAGIQOL (2.2. vs. 2.7; p <0.001) as well as GCSI scores (3.8 vs. 3.0). After 48 weeks, GCSI scores in patients with GES improved by an average of 0.9 compared with 0.3 in controls (p<0.0001) with 43.6% showing improvement of at least 1 point compared with 24.7% in controls (p= 0.004). The odds ratio for improvement with GES, adjusting for baseline differences, was 2.35 (p=0.01) and using a kernel-weighted propensity score, 2.47 (p= 0.007). Conclusions. In this observational study in multiple practice settings for managing gastroparesis patients, 15% required GES therapy and were significantly more likely to show clinically meaningful improvement at 48 weeks than those without GES treatment. Causal effects analysis using propensity score matching supports the use of GES and emphasize its efficacy for symptomatic patients with gastroparesis not responding to standard medical approaches. We encourage further research in targeting GES for gastroparesis patients, including properly designed randomized trials.
299 Diabetic and Idiopathic Gastroparesis Is Associated With Loss of Antral Interstitial Cells of Cajal and CD206 Positive Macrophages Cheryl E. Bernard, Madhusudan Grover, Simon J. Gibbons, Henry P. Parkman, Thomas L. Abell, William J. Snape, Pankaj J. Pasricha, William L. Hasler, Linda A. Lee, Richard W. McCallum, Irene Sarosiek, Linda Anh B. Nguyen, Kenneth L. Koch, James Tonascia, Frank A. Hamilton, Michael L. Kendrick, K. Robert Shen, Todd A. Kellogg, Travis J. McKenzie, KMarie Reid Lombardo, Gianrico Farrugia, GpCRC Consortium Background: Previous studies on biopsies from the gastric body of patients with diabetic gastroparesis have shown loss of interstitial cells of Cajal (ICC) and a correlation between the number of CD206+ (alternatively activated) macrophages and ICC numbers in diabetic gastroparesis. In murine models of diabetic gastroparesis, CD206+ macrophages were found to be protective against cell injury with the most profound loss of ICC occurring in the antrum. Human gastric full thickness biopsies are collected under the aegis of the NIH Gastroparesis Clinical Research Consortium (GpCRC) to help understand the etiology of gastroparesis and develop better therapeutic strategies to treat gastroparesis. Aim: To investigate histological changes in the antrum in patients with gastroparesis. Methods: Biopsies of the gastric antrum were obtained from 7 idiopathic (IG) and 11 diabetic (DG) gastroparetic patients undergoing implantation of a gastric stimulator and from 4 controls without gastroparesis. 12 µm sections were cut from fixed tissue and stained for H&E, Trichrome to assess fibrosis, PGP9.5, nNOS, VIP and SP to assess enteric nerves, Tyrosine hydroxylase (TH) to assess extrinsic innervation, Kit to assess ICC, CD45 to assess immune cells and CD206 to assess alternatively activated macrophages. A change of >25% and <50% of each marker within the myenteric plexus or muscle layers was classified as mild, 50-75% as moderate and greater than 75% as severe. Results: Table one shows the histological findings (numbers represent number of patients with an abnormality, arrows indicate decrease or increase). The most significant finding in both DG and IG was a loss of ICC and CD206+ macrophages in 10/11 patients with DG and 6/7 of patients with IG. In DG, 7 had a moderate loss of ICC and 3 had severe loss; and for CD206+ macrophages 9 had moderate loss and 1 severe. In IG, 1 had a moderate loss of ICC and 5 had severe loss; and for CD206+ macrophages all 6 had moderate loss. Histological abnormalities in smooth muscle and enteric nerves were less frequently found in this cohort. Conclusion: As in the gastric body, the major cellular defect found in the antrum of DG and IG is a loss of ICC. However, unlike the human gastric body, the loss of CD206+ macrophages was much more pronounced in the antrum, consistent with what was found in mouse models of DG. These results point towards an interaction between macrophages and ICC and suggest both may be future therapeutic targets to treat gastroparesis. Supported by DK74008 and DK73983. Table 1
297 Brainstem Dopamine Regulates Gastric Tone and Motility Luca Toti, R. Alberto Travagli Gastrointestinal (GI) dysfunctions, such as gastroparesis, are prodromic to Parkinson's disease (PD). Upper GI functions are modulated by neurons in the dorsal motor nucleus of the vagus (DMV); recently, we reported a monosynaptic dopaminergic connection between the substantia nigra pars compacta (SNpc) and the dorsal vagal complex (DVC), activation of which modulates gastric tone and motility via dopamine (DA)-1 receptors. The effects of DVC application of DA on gastric tone and motility, however, have not been characterized. Gastric tone and motility were recorded in anaesthetized rats using strain gauges sewn onto the anterior gastric wall. DA (0.1pmoles-10nmoles/60nL; N=10-16) microinjected in the left DVC decreased tone and motility in both the corpus (at 1pmole, tone: -98±28mg; at 0.3nmoles motility: -30±7% of baseline) and in the antrum (at 1pmole, tone: -179±42mg; at 0.3nmoles motility: -26±6% of baseline, respectively; P<0.05 for all). Equivalent doses of DA induced a larger decrease in antrum compared to corpus tone, while motility was affected similarly. The effects of DA microinjections on tone and motility were vagallymediated since they were blocked by ipsilateral vagotomy (N=4). The DA-induced decrease in tone and motility were mediated via activation of DA2 receptors, since fourth ventricular administration of the DA2 antagonist, L741626 (45nmoles), but not administration of the DA1 antagonist, SCH23390 (45nmoles), prevented the response to DA microinjection (N= 7 for both antagonists). DVC application of the dopamine uptake inhibitor, benztropine (100nmoles, N=5), increased tone (168± 38 and 152±25mg) and motility (39±12 and 63±17% of baseline) in corpus and antrum, respectively. The excitatory effects of benztropine were antagonized by pretreatment with SCH23390 (N=5), but while motility was inhibited by benztropin + SCH23390, there was no reversal of effects on tone by benztropin following blockade of DA1. Our data indicate that the dopaminergic innervation of the DVC modulates gastric tone and motility differentially: application of exogenous DA induces inhibitory effects on gastric motility and tone, these effects are mediated via DA2 receptors. Application of the DA uptake inhibitor benztropin, conversely, reveals a tonically active, excitatory, DA1mediated input that modulates gastric motility. We would like to suggest that this latter pathway is involved in the reduced gastric motility observed in PD. Sponsored by MJFF for Parkinson's disease
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Altered Expression of Contractile Regulatory Proteins in Patients With Refractory Idiopathic Gastroparesis Brian P. Herring, April M. Hoggatt, Muhammad Idrees, Anita Gupta, Attila Nakeeb, Jennifer N. Choi, Thomas V. Nowak, Joel Wittles, John M. Wo
Oropharyngeal pH Testing Is Not Predictive of Reflux Associated Laryngeal Symptoms: A Prospective Pilot Study Diana Jaiyeola, Rena Yadlapati, Christopher Adkins, Andrew J. Gawron, Michael I. Ellenbogen, Bruce K. Tan, Stephanie Shintani-Smith, Michiel Bove, Caroline Price, Alcina K. Lidder, John E. Pandolfino
Significance: Gastroparesis is a stomach motility disorder characterized by delayed gastric emptying without any evidence of physical obstruction. Gastric emptying requires the coordinated activity of stomach smooth muscle cells (SMCs), interstitial cells of Cajal (ICC) and neurons. Defects in any of these cell types could thus contribute to the pathology of
Introduction: Confirming that oropharyngeal reflux symptoms are related to physiologic reflux disease is challenging. The Restech Dx-pH probe is a minimally invasive nasopharyngeal catheter for the detection of oropharyngeal pH in liquid or aerosolized droplets. Normative
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Effectiveness of Gastric Electrical Stimulation in Gastroparesis: Results From a Large Prospectively Collected Database of a National Gastroparesis Registry Thomas L. Abell, Richard W. McCallum, Kevin P. May, Laura Wilson, Henry P. Parkman, William L. Hasler, Kenneth L. Koch, William J. Snape, John O. Clarke, Linda Anh B. Nguyen, Irene Sarosiek, Gianrico Farrugia, Jorge Calles-Escandon, James Tonascia, Linda A. Lee, Frank A. Hamilton, Pankaj J. Pasricha Introduction. The use of gastric electrical stimulation (GES) for treating gastroparesis is controversial, despite several randomized controlled trials. Given difficulties in conducting placebo-controlled trials for surgical procedures, we utilitzed prospectively collected data from patients enrolled in the Gastroparesis Clinical Research Consortium (GPCRC) registries, some with GES implanted, to evaluate its effectiveness. Methods. We studied idiopathic or diabetic gastroparesis or gastroparesis-like symptoms patients followed in the NIDDK GpCRC who had completed at least 48 week follow-up, with or without insertion of a GES device at any time during this period. Patients were seen every 16 weeks and treated by physicians at 6 academic medical centers. Prospectively collected registry data included detailed histories, validated symptom questionnaires, psychological distress measures and gastric emptying results. Improvement at 48 weeks was evaluated by: absolute change, any improvement, and improvement ‡ 1-point drop, in the Gastroparesis Cardinal Symptom Index (GCSI). Logistic regression compared the odds of GES improvement, whether or not a GES device was implanted, and was reported by unadjusted, adjusted and propensity-adjusted models. Results. Of a total of 688 patients, 54 patients were excluded because GES had been in place at enrollment in the registry. Of the remaining 634, 92 (14.5%) had GES placed after registry enrollment; 48-week data from these patients were compared to 48-week data from the remainder (control group) who never had GES. 38% of patients with GES were diabetic and 54% idiopathic, proportions not different from those without GES. Patients with GES had more delayed gastric emptying at 4 hours (30.9 vs. 21.8; p=0.002), were sicker (46.7% graded as having severe gastroparesis vs. 20.9% in the controls); p<0.001, with worse PAGIQOL (2.2. vs. 2.7; p <0.001) as well as GCSI scores (3.8 vs. 3.0). After 48 weeks, GCSI scores in patients with GES improved by an average of 0.9 compared with 0.3 in controls (p<0.0001) with 43.6% showing improvement of at least 1 point compared with 24.7% in controls (p= 0.004). The odds ratio for improvement with GES, adjusting for baseline differences, was 2.35 (p=0.01) and using a kernel-weighted propensity score, 2.47 (p= 0.007). Conclusions. In this observational study in multiple practice settings for managing gastroparesis patients, 15% required GES therapy and were significantly more likely to show clinically meaningful improvement at 48 weeks than those without GES treatment. Causal effects analysis using propensity score matching supports the use of GES and emphasize its efficacy for symptomatic patients with gastroparesis not responding to standard medical approaches. We encourage further research in targeting GES for gastroparesis patients, including properly designed randomized trials.
299 Diabetic and Idiopathic Gastroparesis Is Associated With Loss of Antral Interstitial Cells of Cajal and CD206 Positive Macrophages Cheryl E. Bernard, Madhusudan Grover, Simon J. Gibbons, Henry P. Parkman, Thomas L. Abell, William J. Snape, Pankaj J. Pasricha, William L. Hasler, Linda A. Lee, Richard W. McCallum, Irene Sarosiek, Linda Anh B. Nguyen, Kenneth L. Koch, James Tonascia, Frank A. Hamilton, Michael L. Kendrick, K. Robert Shen, Todd A. Kellogg, Travis J. McKenzie, KMarie Reid Lombardo, Gianrico Farrugia, GpCRC Consortium Background: Previous studies on biopsies from the gastric body of patients with diabetic gastroparesis have shown loss of interstitial cells of Cajal (ICC) and a correlation between the number of CD206+ (alternatively activated) macrophages and ICC numbers in diabetic gastroparesis. In murine models of diabetic gastroparesis, CD206+ macrophages were found to be protective against cell injury with the most profound loss of ICC occurring in the antrum. Human gastric full thickness biopsies are collected under the aegis of the NIH Gastroparesis Clinical Research Consortium (GpCRC) to help understand the etiology of gastroparesis and develop better therapeutic strategies to treat gastroparesis. Aim: To investigate histological changes in the antrum in patients with gastroparesis. Methods: Biopsies of the gastric antrum were obtained from 7 idiopathic (IG) and 11 diabetic (DG) gastroparetic patients undergoing implantation of a gastric stimulator and from 4 controls without gastroparesis. 12 µm sections were cut from fixed tissue and stained for H&E, Trichrome to assess fibrosis, PGP9.5, nNOS, VIP and SP to assess enteric nerves, Tyrosine hydroxylase (TH) to assess extrinsic innervation, Kit to assess ICC, CD45 to assess immune cells and CD206 to assess alternatively activated macrophages. A change of >25% and <50% of each marker within the myenteric plexus or muscle layers was classified as mild, 50-75% as moderate and greater than 75% as severe. Results: Table one shows the histological findings (numbers represent number of patients with an abnormality, arrows indicate decrease or increase). The most significant finding in both DG and IG was a loss of ICC and CD206+ macrophages in 10/11 patients with DG and 6/7 of patients with IG. In DG, 7 had a moderate loss of ICC and 3 had severe loss; and for CD206+ macrophages 9 had moderate loss and 1 severe. In IG, 1 had a moderate loss of ICC and 5 had severe loss; and for CD206+ macrophages all 6 had moderate loss. Histological abnormalities in smooth muscle and enteric nerves were less frequently found in this cohort. Conclusion: As in the gastric body, the major cellular defect found in the antrum of DG and IG is a loss of ICC. However, unlike the human gastric body, the loss of CD206+ macrophages was much more pronounced in the antrum, consistent with what was found in mouse models of DG. These results point towards an interaction between macrophages and ICC and suggest both may be future therapeutic targets to treat gastroparesis. Supported by DK74008 and DK73983. Table 1
297 Brainstem Dopamine Regulates Gastric Tone and Motility Luca Toti, R. Alberto Travagli Gastrointestinal (GI) dysfunctions, such as gastroparesis, are prodromic to Parkinson's disease (PD). Upper GI functions are modulated by neurons in the dorsal motor nucleus of the vagus (DMV); recently, we reported a monosynaptic dopaminergic connection between the substantia nigra pars compacta (SNpc) and the dorsal vagal complex (DVC), activation of which modulates gastric tone and motility via dopamine (DA)-1 receptors. The effects of DVC application of DA on gastric tone and motility, however, have not been characterized. Gastric tone and motility were recorded in anaesthetized rats using strain gauges sewn onto the anterior gastric wall. DA (0.1pmoles-10nmoles/60nL; N=10-16) microinjected in the left DVC decreased tone and motility in both the corpus (at 1pmole, tone: -98±28mg; at 0.3nmoles motility: -30±7% of baseline) and in the antrum (at 1pmole, tone: -179±42mg; at 0.3nmoles motility: -26±6% of baseline, respectively; P<0.05 for all). Equivalent doses of DA induced a larger decrease in antrum compared to corpus tone, while motility was affected similarly. The effects of DA microinjections on tone and motility were vagallymediated since they were blocked by ipsilateral vagotomy (N=4). The DA-induced decrease in tone and motility were mediated via activation of DA2 receptors, since fourth ventricular administration of the DA2 antagonist, L741626 (45nmoles), but not administration of the DA1 antagonist, SCH23390 (45nmoles), prevented the response to DA microinjection (N= 7 for both antagonists). DVC application of the dopamine uptake inhibitor, benztropine (100nmoles, N=5), increased tone (168± 38 and 152±25mg) and motility (39±12 and 63±17% of baseline) in corpus and antrum, respectively. The excitatory effects of benztropine were antagonized by pretreatment with SCH23390 (N=5), but while motility was inhibited by benztropin + SCH23390, there was no reversal of effects on tone by benztropin following blockade of DA1. Our data indicate that the dopaminergic innervation of the DVC modulates gastric tone and motility differentially: application of exogenous DA induces inhibitory effects on gastric motility and tone, these effects are mediated via DA2 receptors. Application of the DA uptake inhibitor benztropin, conversely, reveals a tonically active, excitatory, DA1mediated input that modulates gastric motility. We would like to suggest that this latter pathway is involved in the reduced gastric motility observed in PD. Sponsored by MJFF for Parkinson's disease
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Altered Expression of Contractile Regulatory Proteins in Patients With Refractory Idiopathic Gastroparesis Brian P. Herring, April M. Hoggatt, Muhammad Idrees, Anita Gupta, Attila Nakeeb, Jennifer N. Choi, Thomas V. Nowak, Joel Wittles, John M. Wo
Oropharyngeal pH Testing Is Not Predictive of Reflux Associated Laryngeal Symptoms: A Prospective Pilot Study Diana Jaiyeola, Rena Yadlapati, Christopher Adkins, Andrew J. Gawron, Michael I. Ellenbogen, Bruce K. Tan, Stephanie Shintani-Smith, Michiel Bove, Caroline Price, Alcina K. Lidder, John E. Pandolfino
Significance: Gastroparesis is a stomach motility disorder characterized by delayed gastric emptying without any evidence of physical obstruction. Gastric emptying requires the coordinated activity of stomach smooth muscle cells (SMCs), interstitial cells of Cajal (ICC) and neurons. Defects in any of these cell types could thus contribute to the pathology of
Introduction: Confirming that oropharyngeal reflux symptoms are related to physiologic reflux disease is challenging. The Restech Dx-pH probe is a minimally invasive nasopharyngeal catheter for the detection of oropharyngeal pH in liquid or aerosolized droplets. Normative
S-65
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