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New insight into mechanisms of predeglutitive aspiration in patients with oropharyngeal dysphagia
AGAA407
April 2000
2115
2117
CLONING AND EXPRESSION OF THE GUINEA PIG VASOACTIVE INTESTINAL POLYPEPTIDE RECEPTOR-I. Jianjing Xue, Fedias L. Christofi, Helen 1. Cooke, The Ohio State Univ, Columbus, OH. Vasoactive intestinal peptide (VIP) is a neuroendocrine mediator found in the central and peripheral nervous systems. Diverse actions of VIP are mediated by subtypes of VIP/pituitary adenylate cyclase-acivating polypeptide (PACAP) receptors including VIP/PACAP z, VIPz/PACAP3 and the natriuretic peptide clearance receptor, NPR-C. The purpose of this study was two-fold: I) to identify whether VIP/PACAPz receptor transcripts and protein were expressed in the mucosa of guinea pig distal colon and 2) to clone and sequence this receptor so that high fidelity antisense oligonucleotides could be designed for future use in this species. Total RNA was isolated from mucosal scrapings of distal colon. Northern analysis revealed transcripts around 1.9 kb and 2.6 kb. An aliquot of total RNA was removed for reverse transcription. Polymerase chain reaction (PCR) was used to amplify the eDNA using primers representing areas of homology for this receptor in rats and humans. Pairs of sense and antisense primers included sequences from exon I, which contains the translation initiation codon, and exon 5 (450 bp), exons 3 and 9 (766 bp), exons 9 and 12-13 (314 bp) and exons 7 and 13, which contains the termination codon (600 bp). PCR resulted in overlapping segments that allowed detection of the entire coding region of the VIP/PACAPz receptor. The cloned receptor consisted of 1371 bp beginning at the translation initiation codon to the termination codon and had 83% and 84% homology with the rat and human, respectively. The amino acid sequence encoded a protein of 456 amino acids with 81% and 83% homology with the rat and human, respectively. Laser confocal immunolluoresce imaging analysis detected the expression of VIP/PACAPz receptors in crypt epithelial cells and in submucosal neurons treated with rabbit antiserum to the epitope encompassing amino acids 191 to 222 in the first extracellular loop. The presence ofVIP/PACAP2 receptor transcripts and their translational products in the mucosa suggests a role for these receptors in the function of epithelial cells or their innervation. Supported by NIH Grants: DK37240 (HJC) and DK44179 (FC).
INTRABOLUS PRESSURE GRADIENT LOCALIZES PATHOLOGICAL CONSTRICTIONS IN THE UPPER ESOPHAGEAL SPHINCTER (UES) DURING FLOW. Anupam Pal, Rohan BH Williams, Ian JS Cook, James G_ Brasseur, Mechanical Engineering, Pennsylvania State Univ, University Park, PA; Gastroenterology, St George Hosp, Univ of NSW, Sydney, Australia; Penn State Univ, University Park, PA. As the bolus is propelled through the UES, pressure drops rapidly in the direction of flow in response to frictional resisting force. ~ The rate of axial pressure .== 1 drop, or intrabolus presf:'-'· IU'/ . sure GRADIENT (ibpG), is sensitive to the degree of ~ constriction. We hypothe- - 00. pIIIit:nto. sized that ibpG provides useful diagnostic measures 1IIl' (mm 1t~ 1 of restricted UES opening. AIM: To identify patterns in ibpG that correlate with UES bolus motion and pathological disruption to flow. METHOD: Highresolution high-fidelity perfused manometry (10 sideholes, I ern spaced, Dentsleeve, Inc.) of swallows (2, 5, 10, 20ml, barium) concurrent with videofluoroscopy in 7 healthy controls and 7 patients with restrictive UES opening (4 Zenker's, 2 CP bars, I CP stenosis). Pressure was displayed as space-time isocontours and the intrabolus pressure domain determined from video. Time-local and time-averaged spatial variations in pressure were calculated. Magnitudes and locations of max ibpG were quantified for each swallow and correlated with the location of the pathological restriction and mid point of the UES. RESULTS: Trans-UES intrabolus pressure always decreased inferiorly (figure). Average and maximum ibpG for patients (dashed line) were significantly higher (p=0.OOO8) than controls (solid line). Maximum ibpG increased with bolus volume in both groups. The location of maximum ibpG in the patients correlated closely with the location of the pathological restriction (r=0.71). DISCUSSION: The correlations show that ibpG reflects forces that both drive and resist bolus motion. In patients maximum ibpG identifies precisely the location of the UES constriction. We hypothesize that ibpG may identify pathological constrictions that are difficult to discern radiologically.
2116 NEW INSIGHT INTO MECHANISMS OF PREDEGLUTITIVE ASPIRATION IN PATIENTS WITH OROPHARYNGEAL DYSPHAGIA. Eytan Bardan, Caryn Easterling, Terilynn Nitschke, Karrylyn Kais, Reza Shaker, Chaim Sheba Med Ctr, Herzlia, Israel; MCW Dysphagia Institute, Med Coli of Wisconsin, Milwaukee, WI; Speech Pathology, VAMC, Milwaukee, WI; Froedtert Hosp, Milwaukee, WI. Although predeglutitive aspiration has generally been attributed to oral pharyngeal sensory deficit and dyscoordination, the exact mechanism responsible has not been clearly elucidated. Reflexive pharyngeal swallow (R) and pharyngoglottal closure reflex (P) have been suggested to prevent predeglutitive aspiration by closing the airway and clearing the pharynx from premature sudden spill of oral content. Aims: Determine the integrity, as well as the threshold volume of liquid required to trigger these two reflexes in patients suffering from predeglutitive aspiration. Methods: We studied 8 patients (ages 32-85 yrs) with predeglutitive aspiration, (7 CVA, I radiation injury) diagnosed by modified barium swallow studies, and 7 healthy controls without deglutitive aspiration. We used a concurrent videoendoscopic and manometric technique. Glottal function was continually recorded by videoendoscopy. Pharyngeal rellexes were stimulated by injection of room temperature blue colored water directed posteriorly through a side hole on a flat manometric catheter 2cm above the manometrically determined UES high pressure zone. We started with 0.1 ml and increased the volume by 0.1 ml increments until either the pharyngoglottal reflex or pharyngeal reflexive swallow were triggered, or the injected water entered the airway without triggering either of the reflexes. Results: Neither pharyngoglottal reflex nor reflexive pharyngeal swallow could be triggered in any patient with injection of volumes as high as .96:±.13ml. At this volume the colored water entered the laryngeal vestibule and trachea without triggering a pharyngoglottal reflex or pharyngeal swallow. In 4 patients, entry of colored water into the trachea triggered a cough reflex. In the control group, the pharyngoglottal closure reflex was activated with a threshold volume of .3:±.07ml and pharyngeal swallow by .6:±.05ml. Conclusions: Pharyngoglottal closure reflex and reflexive pharyngeal swallow are absent in patients with predeglutitive aspiration. This finding offers a mechanistic explanation for some of the swallow related aspiration commonly observed in dysphagic patients.
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2118 ADVERSE EFFECT OF SMOKING ON PHARYNGO-UPPER ESOPHAGEAL SPHINCTER CONTRACTILE REFLEX (PUCR) AND REFLEXIVE PHARYNGEAL SWALLOW (RPS): CENTRAL OR PERIPHERAL MECHANISM? Kulwinder S. Dua, Zhumei Sui, Candy Hoffmann, Reza Shaker, Med Coli of WI, Milwaukee, WI. Introduction: In an earlier study we showed that smoking adversely affects the triggering of PUCR and RPS. Aim: To determine if the adverse effect of smoking on PUCR and RPS is local and/or systemic in origin. Methods: We studied 10 nonsmokers (33:±6 yr) and 9 smokers (34:±8 yr) in an upright position. Smokers were studied before and after smoking two cigarettes and in another session, after applying nicotine patch for 10 hr during which they abstained from smoking. Blood nicotine levels were drawn before and after smoking and after nicotine patch. Nonsmokers were studied before and after simulated smoking of unlit cigarettes. To monitor UES pressure and determine the threshold volume for triggering the above reflexes, we used a sleeve assembly (UES Dentsleeve) that incorporated a pharyngeal injection port oriented posteriorly. PUCR and RPS were evaluated for rapid and slow water injection using previously described methods. Results: The threshold volume for triggering PUCR and RPS increased significantly after smoking two cigarettes. No such increase was noted after nicotine patch despite peak blood nicotine levels being similar (after smoking 41, after nicotine patch 40 ng/ml, p=0.9)_ Conclusions: Smoking adversely affects the triggering of PUCR and RPS_ The adverse effect of smoking on PUCR and RPS is due to its local effect on the pharyngeal receptors and not the effect of nicotine on the central control mechanism of these reflexes.
Threshold volume forPUCR & RPS (ml mean±SE)
Reflex PUCR RPS
PIR
P/R
P/R
P/R
P/R
P/R
PIR
P/R -/-
PIs
-1-
.],
.t .
.]:
.t .
-/-
.t .
Cntrls
+/+
+/+
+/+
+/+
+/+
+/+
+/+
Nonsmoker (Simul.) Pre Post 0.15±0.02 0.3±0.03 0.46±0.05 097+008
0.16±0.02 0.32±0.03 0.48±0.04 0.1±0.09
Smokers (smoking! Nicotine) Pre Post Nic.Patch 0.4±0.05*j 0.77±0.2* 0.8±0.06. 1.4±0.1
0.7±0.09j 0.83±0.1 1.4±0.1t 1.7±0.2
0.3±0.0_ 0.7±0.2oo
O.9±O.h 1.7±03
Injection Rapid Slow Rapid Slow
'p=0.005 smokers vsnonsmokers; jp=0.03 post vspresmoking; oop=0.02 nicotine vsnonsmoker; .p<0.05 smoker vs nonsmoker, tp=0.038 post vs presmoking; "'p<0.05 nicotine vs nonsmoker; +p=0.003 post smoking vsnicotine
April 2000
2115
2117
CLONING AND EXPRESSION OF THE GUINEA PIG VASOACTIVE INTESTINAL POLYPEPTIDE RECEPTOR-I. Jianjing Xue, Fedias L. Christofi, Helen 1. Cooke, The Ohio State Univ, Columbus, OH. Vasoactive intestinal peptide (VIP) is a neuroendocrine mediator found in the central and peripheral nervous systems. Diverse actions of VIP are mediated by subtypes of VIP/pituitary adenylate cyclase-acivating polypeptide (PACAP) receptors including VIP/PACAP z, VIPz/PACAP3 and the natriuretic peptide clearance receptor, NPR-C. The purpose of this study was two-fold: I) to identify whether VIP/PACAPz receptor transcripts and protein were expressed in the mucosa of guinea pig distal colon and 2) to clone and sequence this receptor so that high fidelity antisense oligonucleotides could be designed for future use in this species. Total RNA was isolated from mucosal scrapings of distal colon. Northern analysis revealed transcripts around 1.9 kb and 2.6 kb. An aliquot of total RNA was removed for reverse transcription. Polymerase chain reaction (PCR) was used to amplify the eDNA using primers representing areas of homology for this receptor in rats and humans. Pairs of sense and antisense primers included sequences from exon I, which contains the translation initiation codon, and exon 5 (450 bp), exons 3 and 9 (766 bp), exons 9 and 12-13 (314 bp) and exons 7 and 13, which contains the termination codon (600 bp). PCR resulted in overlapping segments that allowed detection of the entire coding region of the VIP/PACAPz receptor. The cloned receptor consisted of 1371 bp beginning at the translation initiation codon to the termination codon and had 83% and 84% homology with the rat and human, respectively. The amino acid sequence encoded a protein of 456 amino acids with 81% and 83% homology with the rat and human, respectively. Laser confocal immunolluoresce imaging analysis detected the expression of VIP/PACAPz receptors in crypt epithelial cells and in submucosal neurons treated with rabbit antiserum to the epitope encompassing amino acids 191 to 222 in the first extracellular loop. The presence ofVIP/PACAP2 receptor transcripts and their translational products in the mucosa suggests a role for these receptors in the function of epithelial cells or their innervation. Supported by NIH Grants: DK37240 (HJC) and DK44179 (FC).
INTRABOLUS PRESSURE GRADIENT LOCALIZES PATHOLOGICAL CONSTRICTIONS IN THE UPPER ESOPHAGEAL SPHINCTER (UES) DURING FLOW. Anupam Pal, Rohan BH Williams, Ian JS Cook, James G_ Brasseur, Mechanical Engineering, Pennsylvania State Univ, University Park, PA; Gastroenterology, St George Hosp, Univ of NSW, Sydney, Australia; Penn State Univ, University Park, PA. As the bolus is propelled through the UES, pressure drops rapidly in the direction of flow in response to frictional resisting force. ~ The rate of axial pressure .== 1 drop, or intrabolus presf:'-'· IU'/ . sure GRADIENT (ibpG), is sensitive to the degree of ~ constriction. We hypothe- - 00. pIIIit:nto. sized that ibpG provides useful diagnostic measures 1IIl' (mm 1t~ 1 of restricted UES opening. AIM: To identify patterns in ibpG that correlate with UES bolus motion and pathological disruption to flow. METHOD: Highresolution high-fidelity perfused manometry (10 sideholes, I ern spaced, Dentsleeve, Inc.) of swallows (2, 5, 10, 20ml, barium) concurrent with videofluoroscopy in 7 healthy controls and 7 patients with restrictive UES opening (4 Zenker's, 2 CP bars, I CP stenosis). Pressure was displayed as space-time isocontours and the intrabolus pressure domain determined from video. Time-local and time-averaged spatial variations in pressure were calculated. Magnitudes and locations of max ibpG were quantified for each swallow and correlated with the location of the pathological restriction and mid point of the UES. RESULTS: Trans-UES intrabolus pressure always decreased inferiorly (figure). Average and maximum ibpG for patients (dashed line) were significantly higher (p=0.OOO8) than controls (solid line). Maximum ibpG increased with bolus volume in both groups. The location of maximum ibpG in the patients correlated closely with the location of the pathological restriction (r=0.71). DISCUSSION: The correlations show that ibpG reflects forces that both drive and resist bolus motion. In patients maximum ibpG identifies precisely the location of the UES constriction. We hypothesize that ibpG may identify pathological constrictions that are difficult to discern radiologically.
2116 NEW INSIGHT INTO MECHANISMS OF PREDEGLUTITIVE ASPIRATION IN PATIENTS WITH OROPHARYNGEAL DYSPHAGIA. Eytan Bardan, Caryn Easterling, Terilynn Nitschke, Karrylyn Kais, Reza Shaker, Chaim Sheba Med Ctr, Herzlia, Israel; MCW Dysphagia Institute, Med Coli of Wisconsin, Milwaukee, WI; Speech Pathology, VAMC, Milwaukee, WI; Froedtert Hosp, Milwaukee, WI. Although predeglutitive aspiration has generally been attributed to oral pharyngeal sensory deficit and dyscoordination, the exact mechanism responsible has not been clearly elucidated. Reflexive pharyngeal swallow (R) and pharyngoglottal closure reflex (P) have been suggested to prevent predeglutitive aspiration by closing the airway and clearing the pharynx from premature sudden spill of oral content. Aims: Determine the integrity, as well as the threshold volume of liquid required to trigger these two reflexes in patients suffering from predeglutitive aspiration. Methods: We studied 8 patients (ages 32-85 yrs) with predeglutitive aspiration, (7 CVA, I radiation injury) diagnosed by modified barium swallow studies, and 7 healthy controls without deglutitive aspiration. We used a concurrent videoendoscopic and manometric technique. Glottal function was continually recorded by videoendoscopy. Pharyngeal rellexes were stimulated by injection of room temperature blue colored water directed posteriorly through a side hole on a flat manometric catheter 2cm above the manometrically determined UES high pressure zone. We started with 0.1 ml and increased the volume by 0.1 ml increments until either the pharyngoglottal reflex or pharyngeal reflexive swallow were triggered, or the injected water entered the airway without triggering either of the reflexes. Results: Neither pharyngoglottal reflex nor reflexive pharyngeal swallow could be triggered in any patient with injection of volumes as high as .96:±.13ml. At this volume the colored water entered the laryngeal vestibule and trachea without triggering a pharyngoglottal reflex or pharyngeal swallow. In 4 patients, entry of colored water into the trachea triggered a cough reflex. In the control group, the pharyngoglottal closure reflex was activated with a threshold volume of .3:±.07ml and pharyngeal swallow by .6:±.05ml. Conclusions: Pharyngoglottal closure reflex and reflexive pharyngeal swallow are absent in patients with predeglutitive aspiration. This finding offers a mechanistic explanation for some of the swallow related aspiration commonly observed in dysphagic patients.
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2118 ADVERSE EFFECT OF SMOKING ON PHARYNGO-UPPER ESOPHAGEAL SPHINCTER CONTRACTILE REFLEX (PUCR) AND REFLEXIVE PHARYNGEAL SWALLOW (RPS): CENTRAL OR PERIPHERAL MECHANISM? Kulwinder S. Dua, Zhumei Sui, Candy Hoffmann, Reza Shaker, Med Coli of WI, Milwaukee, WI. Introduction: In an earlier study we showed that smoking adversely affects the triggering of PUCR and RPS. Aim: To determine if the adverse effect of smoking on PUCR and RPS is local and/or systemic in origin. Methods: We studied 10 nonsmokers (33:±6 yr) and 9 smokers (34:±8 yr) in an upright position. Smokers were studied before and after smoking two cigarettes and in another session, after applying nicotine patch for 10 hr during which they abstained from smoking. Blood nicotine levels were drawn before and after smoking and after nicotine patch. Nonsmokers were studied before and after simulated smoking of unlit cigarettes. To monitor UES pressure and determine the threshold volume for triggering the above reflexes, we used a sleeve assembly (UES Dentsleeve) that incorporated a pharyngeal injection port oriented posteriorly. PUCR and RPS were evaluated for rapid and slow water injection using previously described methods. Results: The threshold volume for triggering PUCR and RPS increased significantly after smoking two cigarettes. No such increase was noted after nicotine patch despite peak blood nicotine levels being similar (after smoking 41, after nicotine patch 40 ng/ml, p=0.9)_ Conclusions: Smoking adversely affects the triggering of PUCR and RPS_ The adverse effect of smoking on PUCR and RPS is due to its local effect on the pharyngeal receptors and not the effect of nicotine on the central control mechanism of these reflexes.
Threshold volume forPUCR & RPS (ml mean±SE)
Reflex PUCR RPS
PIR
P/R
P/R
P/R
P/R
P/R
PIR
P/R -/-
PIs
-1-
.],
.t .
.]:
.t .
-/-
.t .
Cntrls
+/+
+/+
+/+
+/+
+/+
+/+
+/+
Nonsmoker (Simul.) Pre Post 0.15±0.02 0.3±0.03 0.46±0.05 097+008
0.16±0.02 0.32±0.03 0.48±0.04 0.1±0.09
Smokers (smoking! Nicotine) Pre Post Nic.Patch 0.4±0.05*j 0.77±0.2* 0.8±0.06. 1.4±0.1
0.7±0.09j 0.83±0.1 1.4±0.1t 1.7±0.2
0.3±0.0_ 0.7±0.2oo
O.9±O.h 1.7±03
Injection Rapid Slow Rapid Slow
'p=0.005 smokers vsnonsmokers; jp=0.03 post vspresmoking; oop=0.02 nicotine vsnonsmoker; .p<0.05 smoker vs nonsmoker, tp=0.038 post vs presmoking; "'p<0.05 nicotine vs nonsmoker; +p=0.003 post smoking vsnicotine