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Biomedical subjects

W J Hogan

Publications and source records attributed to W J Hogan.

At least 55 records · Page 3Linked to original sources
PubMed1996

Initiation of esophageal secondary peristalsis by slow fluid infusion in the opossum: effect of hydrochloric acid.

We investigated the mechanisms of slow fluid infusion-induced secondary peristalsis and the effects of hydrochloric acid on this response. In 13 chronically esophagostomized opossum, acidic and neutral barium sulfate were infused into the distal esophagus at a rate of 1.1 ml/min, while recording the esophageal dimension by videofluoroscopy and esophageal intraluminal pressure concurrently. The effects of atropine, tetrodotoxin, capsaicin, and bilateral cervical vagotomy on the response to slow fluid infusion were examined. Acidic barium initiated secondary peristalsis more frequently and at shorter latency with less increase of preperistaltic intraesophageal pressure than neutral barium (P < 0.05). Atropine abolished secondary peristalsis initiated by neutral barium. For acidic barium, atropine decreased the incidence of secondary peristalsis, increased the latency for initiation of secondary peristalsis, and initiated secondary peristalsis more distally (P < 0.05). Tetrodotoxin or vagotomy and capsaicin abolished activation of secondary peristalsis. We concluded that secondary peristalsis can be stimulated in response to slow distension by minute amounts of fluid. This peristalsis is atropine and capsaicin sensitive and vagally mediated. The presence of acid significantly lowers the threshold for stimulation of secondary peristalsis induced by slow fluid distension. This effect seems to be atropine resistant.

Animals↗
PubMed1996

Coordination of deglutitive vocal cord closure and oral-pharyngeal swallowing events in the elderly.

OBJECTIVE: The temporal relationship between deglutitive glottic closure, oropharyngeal bolus transit and other biomechanical swallowing events was studied in 10 healthy elderly subjects by concurrent transnasal videolaryngoscopy, videofluoroscopy, intraluminal pharyngeal manometry and submental electromyography. The results were compared with those of a similar study in a group of young healthy volunteers published previously. RESULTS: Overall, the coordination of various deglutitive biomechanical events in the elderly group was found to be similar to that in the young. However, subtle differences were documented. Contrary to historical young controls, where the onset of the bolus movement from the mouth toward the pharynx invariably occurred after the vocal cords reached their maximum adduction, in the elderly this relationship was variable. In all swallows of two subjects it occurred 0.41 +/- 0.2 s after, and in another two it occurred 0.08 +/- 0.06 s before the maximal vocal cord adduction. Six subjects showed interchanging patterns. Except for the above-mentioned changes, the onset of vocal cord adduction in the elderly also preceded all other studied events, similar to previously published data in the young. In the elderly, the total duration between onset of vocal cord adduction and their complete reopening (2.47 +/- 0.1 s) was similar to that in the young. CONCLUSION: Although subtle alterations occur in the coordination of deglutitive vocal cord closure and oropharyngeal bolus transit in some elderly people, the overall coordination between airway protection and the transit aspect of the oral-pharyngeal phase of swallowing is preserved in the elderly.

Aged↗
PubMed1996

Barrett's ulcer: the clinical significance today.

OBJECTIVES: The present day clinical significance and natural history of Barrett's esophageal ulcer are compared with those reported originally by Barrett. METHODS: Records of patients with Barrett's ulcers followed by the Gastroenterology Service at the Medical College of Wisconsin were reviewed to assess the natural history of the ulcers in patients with Barrett's esophagus. RESULTS: The histories of 14 patients with ulcers in Barrett's esophagus were reviewed. Average follow-up was 5 yr. Ulcers occurred in both short and long segment Barrett's and responded poorly to therapy. Dysplasia occurred in eight patients, and carcinoma developed in two. CONCLUSIONS: Barrett's ulcers occur today and are difficult to manage, as they were 45 yr ago. Complications today, especially dysplasia and carcinoma, are different than those reported by Barrett (life-threatening hemorrhage, esophageal perforation, and stenosis.)

Anti-Ulcer Agents↗
PubMed1995

Esophagopharyngeal distribution of refluxed gastric acid in patients with reflux laryngitis.

BACKGROUND & AIMS: A variety of otolaryngological abnormalities have been attributed to the contact of gastroesophageal refluxate with respective structures of the aerodigestive tract. The aim of this study was to determine and compare the pharyngoesophageal distribution of gastric acid refluxate between patients with proven laryngitis attributed clinically to gastroesophageal reflux and three control groups. METHODS: An ambulatory 24-hour simultaneous three-site pharyngoesophageal pH monitoring technique was used to measure reflux parameters in the pharynx, proximal esophagus, and distal esophagus. RESULTS: Between-group comparison showed no significant difference in the reflux parameters in the distal esophagus between the studied groups. A significantly higher percentage of distal reflux episodes reached the proximal esophagus in the laryngitis group than in the control groups (P < 0.01), and the number of pharyngeal reflux episodes and time of acid exposure were significantly higher in the laryngitis group than in the control groups (P < 0.001). CONCLUSIONS: Compared with normal controls and patients with gastroesophageal reflux disease, pharyngeal reflux of gastric acid is significantly more prevalent and the ratio of proximal to distal esophageal acid reflux episodes is significantly increased in patients with posterior laryngitis. Simultaneous three-site ambulatory pharyngoesophageal pH monitoring may provide supporting evidence when the diagnosis of reflux-induced aerodigestive tract lesions is considered.

Adult↗
PubMed1995

Use of corticosteroids in the prevention of post-ERCP pancreatitis.

BACKGROUND: Pancreatitis frequently complicates diagnostic and therapeutic ERCP. A variety of causes have been implicated. A number of different agents have been used, without success, in an attempt to prevent pancreatitis. METHODS: In the current study, 824 patients with a history of iodine sensitivity were given preprocedure corticosteroid therapy (651 oral steroids and 173 intravenous steroids) in an attempt to prevent allergic reactions. These patients were retrospectively studied in an attempt to determine if corticosteroid administration prevents ERCP-related pancreatitis. Two control groups were used for comparison, including 1000 patients during the same study period (Control Group I) and 1954 patients from the Midwest Pancreaticobiliary Group (Control Group II). RESULTS: There was a significant difference in the overall incidence of post-ERCP pancreatitis in the corticosteroid treated group (4.6%) compared with either control group (Control Group I = 7.4% and Control Group II = 9.1%). Of those patients undergoing therapeutic ERCP, results were even more significant in favor of the steroid-treated group (5.2%) compared with Control Group I (9.7%) and Control Group II (11.2%). CONCLUSIONS: These results demonstrate that the administration of corticosteroids prior to ERCP results in a decreased incidence of post-ERCP pancreatitis. A prospective, randomized, controlled trial is warranted.

Acute Disease↗
PubMed1995

Treatment of pancreatic pseudocysts with ductal communication by transpapillary pancreatic duct endoprosthesis.

BACKGROUND: Endoscopic treatment of pancreatic pseudocysts via cystenterostomy has been recognized as a successful treatment option in carefully selected patients. Pancreatic transpapillary stenting as an alternative treatment option in patients with pancreatic pseudocysts directly communicating with the main duct has received little consideration. The aim of the current study was to assess the safety and utility of transpapillary pancreatic endoprosthesis in the treatment of communicating pseudocysts. METHODS: Twenty-one patients underwent placement of 33 transpapillary endoprostheses for the treatment of symptomatic pancreatic pseudocysts. All pseudocysts communicated with the main pancreatic duct and ranged in size from 3 to 9 cm (mean 6 cm). Eight patients had associated pancreatic duct strictures. RESULTS: Stent placement was successful in all cases: 13 directly into the pseudocyst, 8 beyond the stricture but not into the pseudocyst. Initial resolution of pseudocysts was seen in 17 patients, with 16 patients free of pseudocyst recurrence at mean follow-up of 37 months. All patients with associated strictures were treated successfully. Factors predictive of success included presence of strictures, size of pseudocyst greater than or equal to 6 cm, location in the body of the pancreas, and duration of pseudocyst less than 6 months. Complications included one episode of mild pancreatitis. CONCLUSIONS: Endoscopic treatment of symptomatic pancreatic pseudocysts with ductal communication by transpapillary pancreatic duct stenting is a safe, effective modality and should be considered a first line therapy.

Adult↗
PubMed1995

A comparison of nonionic versus ionic contrast media: results of a prospective, multicenter study. Midwest Pancreaticobiliary Study Group.

BACKGROUND: Pancreatitis is one of the most common complications associated with ERCP. Multiple factors have been implicated for this potentially serious complication. Numerous suggestions for minimizing risks at ERCP have been offered, one of which is to use nonionic, low osmolarity contrast agents for pancreatic injection. Results of previous studies comparing different contrast media have been inconclusive. METHODS: To evaluate the role contrast material plays in the development of post-ERCP pancreatitis, the Midwest Pancreaticobiliary Group performed a prospective double-blind controlled study. A total of 1,979 consecutive ERCP patients were enrolled, and 1,659 patients with pancreatic duct injections were divided into subgroups according to the complexity of the ERCP. Post-ERCP pancreatitis was compared between similar groups. Patients were randomized to receive injections of nonionic, low osmolarity contrast or standard ionic contrast media. RESULTS: The overall incidence of post-procedural pancreatitis was 10.2%. Those with diagnostic ERCP had the lowest incidence at 5.6%. Therapeutic procedures (12.3%) and sphincter of Oddi manometry (15.2%) had higher rates. Those injected with standard (ionic) contrast had an incidence of 10.4% and after injection with lower osmolar (nonionic) contrast, there was a 10% post-procedural pancreatitis rate. CONCLUSIONS: Patients with more complex procedures develop pancreatitis more frequently. The use of low osmolar (nonionic) contrast media does not decrease the incidence of post-ERCP pancreatitis.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed1994

Characterization and quantification of a pharyngo-UES contractile reflex in cats.

We characterized and quantified a reflex from the pharyngeal mucosa to the upper esophageal sphincter (UES). Seventeen cats were decerebrated, and the pharynx was exposed by opening the cricothyroid ligament. UES motor activity was assessed by recording electromyographic (EMG) activity from the pharyngeal constrictors, i.e., the thyropharyngeus (TP) and cricopharyngeus (CP). The pharyngeal mucosa was stimulated by touch or pressure. Both stimuli activated contraction of the CP primarily when applied to the naso-, laryngo-, or hypopharynx, but pressure was more effective. The anteromedial portion of the hypopharynx was the most sensitive zone, but there was no strong stimulus-response relationship. The reflex response to a 1-s stimulus occurred at a delay of 0.46 +/- 0.06 s and lasted 4.5 +/- 0.5 s. This pharyngo-UES reflex was blocked by anesthesia of the mucosa or transection of the glossopharyngeal or pharyngoesophageal nerves but not the vagus nerves. In contrast, the esophago-UES contractile reflex was not blocked by anesthesia of the pharyngeal mucosa or transection of the glossopharyngeal nerves but was blocked by transection of either the vagus or pharyngoesophageal nerves. We concluded that the pharyngo-UES contractile reflex was activated by pharyngeal mucosal mechanoreceptors whose afferent limb was the glossopharyngeal nerve and whose efferent limb was the pharyngoesophageal branch of the vagus nerve.

Animals↗
PubMed1994

Gastroesophageal reflux disease as a likely cause of "idiopathic" subglottic stenosis.

The cause of subglottic stenosis (SGS) is unknown for a subgroup of patients in which there is a female predominance. Seven women ranging in age from 39 to 66 years developed symptomatic and progressive SGS. Six of the 7 patients failed to respond to all measures of conservative and radical surgical intervention. After recent thorough evaluation for gastroesophageal reflux disease (GERD) followed by medical management for such, these 6 patients have stabilized and have responded to surgical management. The seventh patient recently presented with SGS, was evaluated and treated for GERD, and has not required any surgical management. This study suggests that GERD laryngitis may be pertinent in the development of SGS. Medical management of GERD thus appears vital to successful treatment of idiopathic SGS.

Adult↗
PubMed1993

Determinants of intrabolus pressure during esophageal peristaltic bolus transport.

Previous manometric studies of esophageal fluid bolus transport in humans have generally ignored the hydrodynamic distinction between intrabolus pressure and pressure within the lumen-occluded, contracting esophageal segment. In this study we obtained concurrent esophageal videofluoroscopic and intraluminal manometric recordings in supine normal volunteers using different bolus volumes and viscosities and abdominal compression. Intrabolus pressure increased with bolus volume, viscosity, and abdominal compression. Esophageal diameter increased with larger bolus volumes, and this increase was correlated with increases in intrabolus pressure. Intrabolus pressure was highest in the bolus tail. Peak intraluminal pressures > 20 mmHg above basal intrabolus pressure almost invariably were associated with effective peristalsis, whereas values of this pressure differential < 20 mmHg frequently were associated with ineffective peristalsis and retrograde bolus escape. Intrabolus pressure can serve as an important indicator of the forces resisting peristaltic transport and the occurrence of ineffective bolus transport.

Abdomen↗
PubMed1993

Effect of aging and bolus variables on pharyngeal and upper esophageal sphincter motor function.

Effect of aging, bolus volume, temperature, and consistency on the pharyngeal peristalsis, as well as the effect of aging on the upper esophageal sphincter (UES) resting pressure and its response to esophageal distension by air and balloon, were studied in 14 young and 12 healthy elderly volunteers. In both age groups there was no significant volume or temperature effect on amplitude, duration, or velocity of the pharyngeal peristalsis. Compared with water swallows, mashed potato swallows resulted in a significant increase in the amplitude and duration of the hypopharyngeal peristaltic pressure wave (P < 0.05). For water swallows, the amplitude and duration of the peristaltic pressure wave in the hypopharynx were significantly increased in the elderly compared with the young group (P < 0.01). UES resting pressure in the elderly measured 43 +/- 5 (SE) mmHg and was significantly less than that of the young (71 +/- 8 mmHg; P < 0.01). Magnitude of the UES pressure decrease because of esophageal distension by air, as well as magnitude of its pressure increase because of esophageal balloon distension, was similar among young and elderly. 1) Contrary to common expectations, the parameters of the pharyngeal peristaltic pressure wave do not deteriorate in the elderly in their seventh and eighth decade. 2) Compared with the young, hypopharyngeal pressure wave amplitude and duration are significantly increased in the elderly. This increase could be caused by an adaptation response to a pharyngeal outflow compromise. 3) Pharyngeal peristaltic pressure wave amplitude and duration, but not its velocity, are modulated by the bolus consistency. This modulatory mechanism is preserved in the elderly. 4) Although UES resting pressure is significantly decreased in the elderly, its pressure response to esophageal distension by air and balloon is preserved.

Adult↗
PubMed1993

Effect of age and bolus variables on the coordination of the glottis and upper esophageal sphincter during swallowing.

We studied 1) the effect of age and bolus variables on a) the coordination of deglutitive vocal cord adduction and upper esophageal sphincter (UES) relaxation and b) the duration of deglutitive vocal cord adduction; 2) the effect of the presence of a manometric catheter across the UES on the deglutitive glottal function; and 3) the temporal relationship between deglutitive vocal cord closure and swallow-induced apnea. We studied 10 young (23 +/- 2 yr) and 10 healthy elderly (73 +/- 2 yr) volunteers by concurrent videoendoscopy, UES manometry, respirography, and submental surface electromyography. In both groups the onset of vocal cord adduction preceded the onset of UES relaxation, deglutitive apnea, and submental electromyogram swallowing signal. In both groups, bolus volume and temperature did not have any significant effect on the duration of deglutitive vocal cord adduction. In both young and elderly volunteers, water swallows, compared with dry swallows, significantly shortened the interval between the onset of deglutitive vocal cord adduction and the onset of UES relaxation. In conclusion, coordination between deglutitive glottal and UES function, as well as the duration of deglutitive vocal cord adduction, is preserved in the elderly. Bolus volume and temperature do not have a modulatory effect on the duration of vocal cord closure, but water swallow shortens the interval between the onset of glottal closure and UES relaxation. This shortened interval may contribute to the safety of the airway during swallowing of liquid volumes.

Adult↗
PubMed1992

Esophagoglottal closure reflex: a mechanism of airway protection.

Abrupt esophageal distention occurs commonly during gastroesophageal reflux, thereby generating a circumstance favorable to esophagopharyngeal regurgitation and laryngeal aspiration of gastric refluxate. The aims of the present study were to examine the glottal response to esophageal distention by air and regional esophageal distention by a balloon. Fifteen healthy volunteers (age, 25 +/- 5 years) were studied while they were in an upright position. Using concurrent videoendoscopy and manometry, glottal and upper esophageal sphincter (UES) responses to abrupt esophageal distention by air injection (10-60 mL) and balloon distention (1.5, 2.0, and 2.5 cm) were recorded simultaneously. In addition, 6 subjects were studied with concurrent synchronized videofluoroscopy. Results showed that esophageal distention by air at a threshold volume of 10-60 mL caused vocal cord closure. The UES response to this threshold volume was variable. Volumes larger than the threshold value caused complete UES relaxation and belching. In addition to vocal cord closure, belching was accompanied by anterior movement of the glottis. On videofluoroscopy, the hyoid bone moved anteriorly in association with belching, but not with vocal cord closure without belching. Proximal esophageal distention by the balloon also provoked vocal cord closure. This response was less consistent for balloon distention in the middle and distal esophagus. It is concluded that (a) esophageal distention by either air or a balloon evokes a glottal closure mechanism, thereby suggesting the existence of an esophagoglottal reflex; (b) this reflex is elicited most easily by distention of the proximal esophagus; (c) glottal and UES responses to esophageal distention are independent from each other; and (d) the esophagoglottal closure reflex may play an important role in preventing laryngeal aspiration of acid due to gastroesophageal reflux accompanied by acid regurgitation into the pharynx.

Adult↗
PubMed1992

Alteration of the upper esophageal sphincter belch reflex in patients with achalasia.

Some patients with achalasia have been reported to develop airway obstruction from a massively air-distended esophagus, which may represent an abnormality in the upper esophageal sphincter belch reflex. When questioned carefully, 95% of our achalasia patients reported difficulty with belching. The upper esophageal belch reflex in 23 consecutive achalasia patients and 12 healthy controls was studied using an upper esophageal sphincter sleeve manometry catheter and rapid injection of 20-50 mL of air into the midesophagus. Compared with normal subjects, achalasia patients were significantly less likely to have an esophageal belch for all volumes tested and were more likely to have an increase rather than a decrease in upper esophageal sphincter pressure in response to air injection. This study systematically documents that many achalasia patients have an alteration in the upper esophageal sphincter belch reflex that may be a contributory mechanism for some of the chest and upper airway symptoms reported by some patients during acute esophageal distension.

Adolescent↗