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Comparison of the cortical representation of volitional and reflexive (pharyngeal) swallowing
April 2000
AGAA853
4763
4765
IMMUNOLOGIC RESPONSE TO A NOVEL PRO BIOTIC ORGANISM IN PATmNTS WITH ACTIVE CROHN'S DISEASE. Liam O'Mahony, Jane McCarthy, Maria Feeney, Colum Dunne, Barry Kiely, Gerald C. O'Sullivan, John K. Collins, Fergus Lj Shanahan, Nui, Cork, Ireland. Background: Enteric microflora have been implicated in the pathogenesis ofCrohn's disease, prompting investigation of probiotic therapy. However, little is known of the immunologic response to probiotic organisms in Crohn's disease. This is important because Crohn' s disease is associated with increased intestinal permeability, marked serologic responses to various pathogens and non-pathogens, and loss of immunologic tolerance to enteric microflora. We reported the selection criteria for Lactobacillus salivarius (spp UCC118) as a probiotic organism and described the microbial and immunologic outcomes of feeding trials in normal subjects. Aim: to assess the secretory IgA response and systemic serologic and cytokine responses to oral L. Salivarius in active Crohn's disease. Methods: 21 consecutive patients with mild active Crohn's disease, in whom a change of therapy was considered necessary, were studied. Patients were already taking a stable dose of oral 5-ASA but were not on steroids and were offered a trial of probiotic therapy (10 10 ogranisms in yoghurt/day for 6 wks) instead of steroids. The CDAI was 175-250; those with more active disease requiring steroids or other therapy were excluded. Systemic L. salivarius l18-specific antibody was measured by microtiter plate agglutination and salivary IgA response was measured by a validated Ig-bound, organism-specific, flow cytometric assay. Cytokines were measured by ELISA. Compliance was confirmed by fecal isolation of the probiotic in all subjects. Results: In contrast to our previous results in normal subjects, a serum IgG response to the probiotic organism was evident after 3-6 weeks, becoming significantly elevated over baseline after 6 weeks (p < 0.01). There was no significant alteration in cytokine levels (IFN, IL-8, IL-lRA, sIL-6R), although those patients with an elevated TNF level had a marked reduction after probiotic feeding. A significant organism-specific salivary IgA response was evident at 3 weeks in 50% of patients. Mean CDAI was not significantly altered but 11/21 patients have not required steroids 2=2 months after probiotic therapy. Conclusion: (I) patients with active Crohn's disease have significant systemic IgG and local mucosal IgA responses to probiotic L. salivarius (UCCl18) organisms; (2) this supports the view that this probiotic strain is not in simple transit but engages the mucosal immune response; (3) in contrast to normal subjects, systemic immune responses in Crohn's disease to probiotics should be anticipated.
LOWER ESOPHAGEAL SPHINCTER RELAXATION AND ACTIVATION OF MEDULLARY NEURONS BY DIAPHRAGMATIC VAGAL NERVE STIMULATION IN THE MOUSE. Qian Sang, Raj K. Goyal, VAMClWest Roxbury, Harvard Med Sch, West Roxbury, MA. Background/Aims:Isolated relaxation of the lower esophageal sphincter (LES) is associated with gastroesophageal reflux, belching, and vomiting. Isolated LES relaxation associated with gastroesophageal reflex is often referred as transient LES relaxation (tLESR). The isolated relaxation is thought to be a vago-vagal reflex activated by gastric vagal afferents. On the other hand, swallow-induced LES relaxation that is accompanied by esophageal peristalstic contraction is also a vago-vagal reflex that is mediated by pharyngeal vagal afferents. We have reported that electrical stimulation of superior laryngeal nerve (SLN) elicit swallow associated LES relaxation and activation of neurons in certain vagal subnuclei (Sang & Goyal, 1999, Gastroenterology 116:AI074). The purpose of this study was to investigate whether electrical stimulation of abdominal vagal afferents elicited isolated LES relaxation and further to see if it activated vagal subnuclei different from that those activation by SLN stimulation. Methods:Studies were performed in anesthetized adult mice. LES pressure response to electrical stimulation of ventral subdiaphragmatic vagus (vtSDV) were recorded manometrically and activated neurons in vagal subnuclei were detected by c-fos immunohistochemical staining. Vagal subnuclei in the mouse were identified by cytoarchitectial details and special staining of serial sections of the brainstem. Results:vtSDV stimulation elicited frequency-dependent lower esophageal sphincter relaxation without evoking esophageal contractions. vtSDV stimulation induced c-fos expression in solitary subnuclei located caudal to the anterior border of the area postrema including commissural, medial and dorsomedial subnuclei. The neurons in the outer shell of area postrema and dorsal motor nucleus of vagus were also activated. Interstitial, intermediate or central solitary subnuclei or nucleus ambiguus that express c-fos on swallow associated with SLN stimulation were not activated. Conclusion:Stimulation of vtSDV causes LES relaxation and activates vagal subnuclei that are different from those activated by swallow evoked LES relaxation induced by SLN stimulation. These observations suggest that different brainstem circuits may be involved in swallow-induced and isolated lower esophageal sphincter relaxation.
4764
COMPARISON OF THE CORTICAL REPRESENTATION OF VOLITIONAL AND REFLEXIVE (PHARYNGEAL) SWALLOWING. Mark K. Kern, Ronald C. Arndorfer, James S. Hyde, Reza Shaker, Med Coli of Wisconsin, Milwaukee, WI. Cerebral activity associated with volitional swallowing has been shown to include multiple foci in both motor and non-motor cortical regions. The possible cortical involvement in reflexive/pharyngeal swallowing, mainly a brain stem mediated function, has not been studied. Aims: To characterize cerebral cortical activity associated with reflexive swallowing elicited by pharyngeal water injection and compare the findings to those of volitional swallowing. Methods: Eight asymptomatic, young subjects (age 24-37, 5 male and 3 female) were studied during six 3 minute whole brain FMRI scans using the single trial technique. During three FMRI scans, subjects were cued to volitionally swallow once every 30 seconds. In three other scans, a reflexive swallow was elicited every 30 seconds by injecting a predetermined threshold volume of water directed at the posterior pharyngeal wall through an injection port positioned manometrically 2 ern above the pharyngo-esophageal high pressure zone. Results: All subjects showed a discernible FMRI response to both reflexive and volitional swallowing. Reflexive swallowing resulted in cortical activity in sensory and motor regions. Volitional swallowing resulted in cortical activity concentrated bilaterally in the sensory and motor regions as well as the insula, the cingulate and the precuneus/cuneus. Percent change from baseline FMRI signals were not significantly different in correlated regions when comparing reflexive to volitional swallowing. Conclusions: Reflexive swallowing is associated with a cerebral cortical activity pattern different than volitional swallowing. Reflexive swallowing cortical activity is limited to the sensory/motor cortex while volitional swallowing encompasses the sensory/motor cortex, insula, cingulate and precuneus/cuneus. These additional areas may represent intent, planning, anticipation and urge associated with swallowing.
IN VITRO FERMENTATION OF DIFFERENT TYPES OF DI· ETARY FmER IN ULCERATIVE COLITIS: PRODUCTION OF BUTYRATE. Fernando Fernandez-Banares, Lourdes Fluvia, Jose M. Hernandez, Elisabet Navarro, Miquel A. Gassull, Hosp Germans Trias i Pujol, Barcelona, Spain. In a previous study we observed that a dietary fiber which yields butyrate in the colon (Plantago ovata seeds) was able to maintain remission in ulcerative colitis (UC) as compared to mesalazine (Am J Gastroenterol 1999). Recently, different studies have shown that butyrate may have an anti-inflammatory effect by modulating the release of pro-inflammatory cytokines. Aim: To assess in vitro the ability of different types of dietary fiber to yield short chain fatty acids (SCFA), especially butyrate, in patients with UC in remission. Methods: Fresh stools specimens were collected from 8 patients with UC in remission. Fecal homogenates (feces diluted 1:5 with sodium bicarbonate) were incubated under anaerobic conditions (nitrogen), at 37°C for 0, 6 and 24 h, with the different types of fiber as dry power (20 mg/ml): Fiber A, Plantago ovata seeds; Fiber B, Plantago ovata husk (POH); Fiber C, POH + Resistant starch 1 g; Fiber D, POH +Resistant starch 0.5 g. Fecal suspensions without additions served as control. The bacterial fermentation was stopped by freezing at -80°C. SCFAs were determined by GLC using a semicapilar column. Friedman s two-way analysis of variance for repeated measures was used in the statistical analysis. Results: A significant increase in total SCFA production at 6 hand 24 h was observed with all fibers as compared to basal values. Results at 6 h and 24 h are shown in the Table (a% respect to basal value; p<0.005 vs No fiber at 24 h). Butyrate levels were higher with Fiber A than with the other types of fiber (24 h: 19.6±3 vs 13.6±3, l6.2±3, l4.1±3 mmol/g, p=0.07 vs others and p=0.04 vs Fiber B; 8.3±O.8 vs 5.2±0.7, 6.5±O.9, 5.4±0.6 percent of Total SCFAs, p=O.OO6 vs others). Conclusions: Although all types of fiber studied produce in vitro similar amounts of SCFA, Plantago ovata seeds showed a higher trend to produce butyrate.
LSCFA (6hours) LSCFA (24 hours)
NoFiber
Fiber A
Fiber B
FlberC
Fiber D
231±57 300±48
626±151 1008±221
517±96 904±110
601±99 919±164
550±61 837±130
4766
Reflexive Swallow ing
AGAA853
4763
4765
IMMUNOLOGIC RESPONSE TO A NOVEL PRO BIOTIC ORGANISM IN PATmNTS WITH ACTIVE CROHN'S DISEASE. Liam O'Mahony, Jane McCarthy, Maria Feeney, Colum Dunne, Barry Kiely, Gerald C. O'Sullivan, John K. Collins, Fergus Lj Shanahan, Nui, Cork, Ireland. Background: Enteric microflora have been implicated in the pathogenesis ofCrohn's disease, prompting investigation of probiotic therapy. However, little is known of the immunologic response to probiotic organisms in Crohn's disease. This is important because Crohn' s disease is associated with increased intestinal permeability, marked serologic responses to various pathogens and non-pathogens, and loss of immunologic tolerance to enteric microflora. We reported the selection criteria for Lactobacillus salivarius (spp UCC118) as a probiotic organism and described the microbial and immunologic outcomes of feeding trials in normal subjects. Aim: to assess the secretory IgA response and systemic serologic and cytokine responses to oral L. Salivarius in active Crohn's disease. Methods: 21 consecutive patients with mild active Crohn's disease, in whom a change of therapy was considered necessary, were studied. Patients were already taking a stable dose of oral 5-ASA but were not on steroids and were offered a trial of probiotic therapy (10 10 ogranisms in yoghurt/day for 6 wks) instead of steroids. The CDAI was 175-250; those with more active disease requiring steroids or other therapy were excluded. Systemic L. salivarius l18-specific antibody was measured by microtiter plate agglutination and salivary IgA response was measured by a validated Ig-bound, organism-specific, flow cytometric assay. Cytokines were measured by ELISA. Compliance was confirmed by fecal isolation of the probiotic in all subjects. Results: In contrast to our previous results in normal subjects, a serum IgG response to the probiotic organism was evident after 3-6 weeks, becoming significantly elevated over baseline after 6 weeks (p < 0.01). There was no significant alteration in cytokine levels (IFN, IL-8, IL-lRA, sIL-6R), although those patients with an elevated TNF level had a marked reduction after probiotic feeding. A significant organism-specific salivary IgA response was evident at 3 weeks in 50% of patients. Mean CDAI was not significantly altered but 11/21 patients have not required steroids 2=2 months after probiotic therapy. Conclusion: (I) patients with active Crohn's disease have significant systemic IgG and local mucosal IgA responses to probiotic L. salivarius (UCCl18) organisms; (2) this supports the view that this probiotic strain is not in simple transit but engages the mucosal immune response; (3) in contrast to normal subjects, systemic immune responses in Crohn's disease to probiotics should be anticipated.
LOWER ESOPHAGEAL SPHINCTER RELAXATION AND ACTIVATION OF MEDULLARY NEURONS BY DIAPHRAGMATIC VAGAL NERVE STIMULATION IN THE MOUSE. Qian Sang, Raj K. Goyal, VAMClWest Roxbury, Harvard Med Sch, West Roxbury, MA. Background/Aims:Isolated relaxation of the lower esophageal sphincter (LES) is associated with gastroesophageal reflux, belching, and vomiting. Isolated LES relaxation associated with gastroesophageal reflex is often referred as transient LES relaxation (tLESR). The isolated relaxation is thought to be a vago-vagal reflex activated by gastric vagal afferents. On the other hand, swallow-induced LES relaxation that is accompanied by esophageal peristalstic contraction is also a vago-vagal reflex that is mediated by pharyngeal vagal afferents. We have reported that electrical stimulation of superior laryngeal nerve (SLN) elicit swallow associated LES relaxation and activation of neurons in certain vagal subnuclei (Sang & Goyal, 1999, Gastroenterology 116:AI074). The purpose of this study was to investigate whether electrical stimulation of abdominal vagal afferents elicited isolated LES relaxation and further to see if it activated vagal subnuclei different from that those activation by SLN stimulation. Methods:Studies were performed in anesthetized adult mice. LES pressure response to electrical stimulation of ventral subdiaphragmatic vagus (vtSDV) were recorded manometrically and activated neurons in vagal subnuclei were detected by c-fos immunohistochemical staining. Vagal subnuclei in the mouse were identified by cytoarchitectial details and special staining of serial sections of the brainstem. Results:vtSDV stimulation elicited frequency-dependent lower esophageal sphincter relaxation without evoking esophageal contractions. vtSDV stimulation induced c-fos expression in solitary subnuclei located caudal to the anterior border of the area postrema including commissural, medial and dorsomedial subnuclei. The neurons in the outer shell of area postrema and dorsal motor nucleus of vagus were also activated. Interstitial, intermediate or central solitary subnuclei or nucleus ambiguus that express c-fos on swallow associated with SLN stimulation were not activated. Conclusion:Stimulation of vtSDV causes LES relaxation and activates vagal subnuclei that are different from those activated by swallow evoked LES relaxation induced by SLN stimulation. These observations suggest that different brainstem circuits may be involved in swallow-induced and isolated lower esophageal sphincter relaxation.
4764
COMPARISON OF THE CORTICAL REPRESENTATION OF VOLITIONAL AND REFLEXIVE (PHARYNGEAL) SWALLOWING. Mark K. Kern, Ronald C. Arndorfer, James S. Hyde, Reza Shaker, Med Coli of Wisconsin, Milwaukee, WI. Cerebral activity associated with volitional swallowing has been shown to include multiple foci in both motor and non-motor cortical regions. The possible cortical involvement in reflexive/pharyngeal swallowing, mainly a brain stem mediated function, has not been studied. Aims: To characterize cerebral cortical activity associated with reflexive swallowing elicited by pharyngeal water injection and compare the findings to those of volitional swallowing. Methods: Eight asymptomatic, young subjects (age 24-37, 5 male and 3 female) were studied during six 3 minute whole brain FMRI scans using the single trial technique. During three FMRI scans, subjects were cued to volitionally swallow once every 30 seconds. In three other scans, a reflexive swallow was elicited every 30 seconds by injecting a predetermined threshold volume of water directed at the posterior pharyngeal wall through an injection port positioned manometrically 2 ern above the pharyngo-esophageal high pressure zone. Results: All subjects showed a discernible FMRI response to both reflexive and volitional swallowing. Reflexive swallowing resulted in cortical activity in sensory and motor regions. Volitional swallowing resulted in cortical activity concentrated bilaterally in the sensory and motor regions as well as the insula, the cingulate and the precuneus/cuneus. Percent change from baseline FMRI signals were not significantly different in correlated regions when comparing reflexive to volitional swallowing. Conclusions: Reflexive swallowing is associated with a cerebral cortical activity pattern different than volitional swallowing. Reflexive swallowing cortical activity is limited to the sensory/motor cortex while volitional swallowing encompasses the sensory/motor cortex, insula, cingulate and precuneus/cuneus. These additional areas may represent intent, planning, anticipation and urge associated with swallowing.
IN VITRO FERMENTATION OF DIFFERENT TYPES OF DI· ETARY FmER IN ULCERATIVE COLITIS: PRODUCTION OF BUTYRATE. Fernando Fernandez-Banares, Lourdes Fluvia, Jose M. Hernandez, Elisabet Navarro, Miquel A. Gassull, Hosp Germans Trias i Pujol, Barcelona, Spain. In a previous study we observed that a dietary fiber which yields butyrate in the colon (Plantago ovata seeds) was able to maintain remission in ulcerative colitis (UC) as compared to mesalazine (Am J Gastroenterol 1999). Recently, different studies have shown that butyrate may have an anti-inflammatory effect by modulating the release of pro-inflammatory cytokines. Aim: To assess in vitro the ability of different types of dietary fiber to yield short chain fatty acids (SCFA), especially butyrate, in patients with UC in remission. Methods: Fresh stools specimens were collected from 8 patients with UC in remission. Fecal homogenates (feces diluted 1:5 with sodium bicarbonate) were incubated under anaerobic conditions (nitrogen), at 37°C for 0, 6 and 24 h, with the different types of fiber as dry power (20 mg/ml): Fiber A, Plantago ovata seeds; Fiber B, Plantago ovata husk (POH); Fiber C, POH + Resistant starch 1 g; Fiber D, POH +Resistant starch 0.5 g. Fecal suspensions without additions served as control. The bacterial fermentation was stopped by freezing at -80°C. SCFAs were determined by GLC using a semicapilar column. Friedman s two-way analysis of variance for repeated measures was used in the statistical analysis. Results: A significant increase in total SCFA production at 6 hand 24 h was observed with all fibers as compared to basal values. Results at 6 h and 24 h are shown in the Table (a% respect to basal value; p<0.005 vs No fiber at 24 h). Butyrate levels were higher with Fiber A than with the other types of fiber (24 h: 19.6±3 vs 13.6±3, l6.2±3, l4.1±3 mmol/g, p=0.07 vs others and p=0.04 vs Fiber B; 8.3±O.8 vs 5.2±0.7, 6.5±O.9, 5.4±0.6 percent of Total SCFAs, p=O.OO6 vs others). Conclusions: Although all types of fiber studied produce in vitro similar amounts of SCFA, Plantago ovata seeds showed a higher trend to produce butyrate.
LSCFA (6hours) LSCFA (24 hours)
NoFiber
Fiber A
Fiber B
FlberC
Fiber D
231±57 300±48
626±151 1008±221
517±96 904±110
601±99 919±164
550±61 837±130
4766
Reflexive Swallow ing