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Biomedical subjects

M Guelrud

Publications and source records attributed to M Guelrud.

At least 19 recordsLinked to original sources
PubMed1996

Endoscopic retrograde cholangiopancreatography in children.

In the past two decades, the possibility to visualize the biliary tree and the pancreatic duct using endoscopic retrograde cholangiopancreatography (ERCP) has substantially influenced evaluation and treatment of adult patients with suspected pancreaticobiliary disease. Development of pediatric duodenoscopes, expansion of indications for the procedure in children, and availability of newly skilled pediatric endoscopists have resulted in an increasing number of these procedures being performed in children. Operative endoscopic procedures are also applicable to children and adolescents; techniques such as endoscopic sphincterotomy, biliary drainage, common bile duct stone and pancreatic duct stone extraction, implantation of endoprosthesis, and pancreatic pseudocyst drainage are beginning to be used in children, with an overall success rate similar to that seen in adult patients. Techniques, indications, complications, and diagnostic and therapeutic applications of ERCP in the pediatric population are defined.

Biliary Tract Diseases↗
PubMed1994

Prevalence of Helicobacter pylori in neonates and young infants undergoing ERCP for diagnosis of neonatal cholestasis.

This study was carried out to determine the prevalence of Helicobacter pylori infection in 20 neonates and young infants from lower socioeconomic background undergoing endoscopic retrograde cholangiopancreatography (ERCP) examination for diagnosis of neonatal cholestasis. One young asymptomatic infant (5%) who was breast-feeding with complementary formula had H. pylori infection. Endoscopy showed a normal appearing mucosa and histology demonstrated mild superficial acute gastritis. A follow-up gastroscopy performed 14 months after the initial study showed normal histology without evidence of H. pylori, suggesting that the infection was transient. Nineteen (95%) of the 20 mothers had H. pylori infection, including the mother with the infant positive for H. pylori. All mothers had gastritis on biopsy specimens. Despite the high prevalence of H. pylori in the mothers, infection in neonates and young infants was uncommon.

Biopsy↗
PubMed1992

The effect of vasoactive intestinal polypeptide on the lower esophageal sphincter in achalasia.

Vasoactive intestinal polypeptide (VIP) is one of the main neurotransmitters implicated in the relaxation of the lower esophageal sphincter (LES). The effect of exogenous VIP on LES motor activity was determined by esophageal manometry. LES pressure (LESP) and LES relaxation were compared in four healthy volunteers and in six patients with achalasia. The effects of intravenous doses of 1.5, 3, and 5 pmol.kg-1.min-1 of VIP were compared with placebo. Neither placebo nor 3 and 5 pmol.kg-1.min-1 of VIP produced any effect on esophageal motility in healthy volunteers. In achalasia the three doses of VIP caused a dose-dependent decrease in LESP with a significant improvement in LES relaxation. A dose of 5 pmol.kg-1.min-1 produced a maximal decrease of 51% in LESP. A beta-adrenergic agonist, isoproterenol, caused a decrease in LESP both in healthy volunteers and in patients with achalasia without improving LES relaxation. In summary, intravenous VIP improved LES relaxation and caused a decrease in LESP in patients with achalasia without affecting LESP in healthy volunteers, indicating that the LES muscle in achalasia is supersensitive to VIP. The current study suggests that a selective damage in the noncholinergic nonadrenergic innervation of the esophagus is in part responsible for the motor alteration seen in these patients. The findings and the inability of isoproterenol to improve LES relaxation despite decreasing LESP support a role in VIP as a indicator of LES relaxation.

Adolescent↗
PubMed1991

Transcutaneous electrical nerve stimulation decreases lower esophageal sphincter pressure in patients with achalasia.

Vasoactive intestinal peptide (VIP) is believed to be an inhibitory neurotransmitter responsible for lower esophageal sphincter (LES) relaxation. In patients with achalasia the concentration of VIP and the number of VIP-containing nerve fibers are reduced or absent. It has been suggested that the response to low-frequency transcutaneous electrical nerve stimulation (TENS) may be mediated by a nonadrenergic noncholinergic pathway in which the release of VIP is responsible for the smooth muscle relaxation. The present study was designed to evaluate the effect of TENS on LES pressure and on VIP plasma concentrations in six patients with achalasia (five female, one male). TENS was performed daily during one week for 45-min sessions with a pocket stimulator that delivered low-frequency pulses (6.5 Hz), at 10 pulses/sec of 0.1-msec duration at intensities of 10-20 mA until rhythmic flexion of the fingers was obtained without producing pain. LES pressure and VIP levels were obtained before TENS, after the first 45-min session, and after a week of daily stimulation. After 45-min, TENS produced a significant reduction (P less than 0.01) in LES resting pressure from the mean value 56 +/- 6.4 mm Hg to 42.3 +/- 6.4 mm Hg; with LES relaxation improvement from 50.6 +/- 3% to 63.1 +/- 3.2% (P less than 0.01). After one week of daily TENS, an additional reduction in LES resting pressure (40.3 +/- 4 mm Hg) was observed (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

High vasoactive intestinal polypeptide plasma levels in patients with Barrett's esophagus.

We have evaluated the correlation between vasoactive intestinal polypeptide (VIP) plasma concentration and severity of gastroesophageal reflux in patients with Barrett's esophagus and the possible differences in the VIP values of these patients compared with healthy volunteers. We also evaluated the relation between VIP plasma concentration and lower esophageal sphincter (LES) pressure in 24 patients with Barrett's esophagus. The mean VIP plasma concentration in 14 patients with severe gastroesophageal reflux was 25.6 +/- 0.75 pg/ml, significantly higher than the mean value observed in 10 patients with moderate reflux (18.9 +/- 0.67 pg/ml) (p less than 0.01). The mean LES resting pressure was significantly lower in the group of patients with severe gastroesophageal reflux than that observed in patients with moderate reflux (3 +/- 0.64 and 10.3 +/- 0.69 mm Hg, respectively; p less than 0.01). The mean VIP plasma concentration in 11 healthy volunteers (20.6 +/- 0.65 pg/ml) was significantly lower than the mean value observed in the subgroup of patients with severe gastroesophageal reflux (p less than 0.01). VIP values in patients with moderate reflux were not significantly different from those observed in our volunteers. There was a significant correlation between LES pressure and VIP plasma level (r = -0.9253; p less than 0.01). In conclusion, it is possible that the decreased LES resting pressure observed in patients with Barrett's esophagus and severe gastroesophageal reflux may be due to impairment of the VIPergic innervation, resulting in an increased local VIP release with possible overflow to peripheral plasma.

Adult↗
PubMed1991

The effect of transcutaneous nerve stimulation on sphincter of Oddi pressure in patients with biliary dyskinesia.

Vasoactive intestinal polypeptide (VIP) has been postulated as a neuropeptide with inhibitory neurotransmitter activity in nonadrenergic noncholinergic pathways. Transcutaneous electric nerve stimulation (TENS) relaxes the lower esophageal sphincter in patients with achalasia. Such response is accompanied by a 30% increase in VIP concentrations in the systemic circulation. Since the sphincter of Oddi (SO) receives a very dense VIP nerve supply, we evaluate the effect of TENS on SO motor activity and on VIP plasma concentrations in patients with biliary dyskinesia and in healthy volunteers. TENS was performed with a pocket stimulator for 45 min. SO pressure and VIP levels were obtained before and after 45 min of TENS. In patients with SO dyskinesia, TENS produced a significant decrease in SO pressure from 80.1 +/- 11.9 mm Hg to 58.3 +/- 9.7 mm Hg p less than 0.01); this was accompanied by a significant increase in VIP plasma levels from 21.1 +/- 0.5 pg/ml to 32.6 +/- 1.5 pg/ml (p less than 0.01). In healthy volunteers, TENS did not produce significant changes in SO pressure. However, a significant increase in VIP plasma values was observed (p less than 0.01). No significant changes in amplitude, duration and frequency of SO phasic contractions were observed in either of the two groups evaluated. We conclude that, in patients with SO dyskinesia, TENS decreases SO basal pressure, possibly by a direct action of the released VIP in the systemic circulation. In healthy volunteers, TENS increases VIP plasma values without significant effect on SO basal pressure. These findings suggest that the response to TENS may be mediated by VIP. It is also possible that the alterations seen in patients with biliary dyskinesia may be due to impairment of the VIP nerve supply at the level of the SO.

Adult↗
PubMed1990

Sphincter of Oddi manometry in healthy volunteers.

In this study we describe in detail the characteristics of sphincter of Oddi motor function in a large group of healthy subjects. Studies were obtained in 50 healthy volunteers. The findings showed a sphincter of Oddi segment that had a basal pressure of 14.8 +/- 6.3 mm Hg (X +/- SD). Phasic contractions were superimposed on the basal pressure. They had an amplitude of 119.7 +/- 32 mm Hg, a duration of 4.7 +/- 1 sec, and a frequency of 5.7 +/- 1.2 contractions/min. In 40 subjects the propagation sequence of phasic contractions could be evaluated and were simultaneous in 53%, antegrade in 35%, and retrograde in 11% of the waves. In 20 subjects, pressure measurements done at the common bile duct sphincter waves. In 20 subjects, pressure measurements done at the common bile duct sphincter were similar to those obtained at the pancreatic duct sphincter. In 10 subjects, pressure values obtained at the common bile duct sphincter within a week were similar. Our study should help to establish standards for normal manometric values of the sphincter of Oddi and emphasizes the importance of having a healthy volunteer group from which to obtain the normal values of sphincter of Oddi motor function.

Adult↗
PubMed1988

Effect of nifedipine on sphincter of Oddi motor activity: studies in healthy volunteers and patients with biliary dyskinesia.

The effect of nifedipine on sphincter of Oddi (SO) motor activity was determined by endoscopic manometry. Sphincter of Oddi pressures and motor function were compared in 21 healthy volunteers and in 9 patients with SO dyskinesia. The effects of sublingual doses of 10 or 20 mg of nifedipine were compared with placebo. Neither placebo nor 10 mg of nifedipine produced any effect on SO motor activity. In healthy volunteers 20 mg of nifedipine produced a moderate but significant decrease in basal SO pressure from 12.0 to 6.7 mmHg as well as in the amplitude, duration, and frequency of phasic contractions. In patients with SO dyskinesia 20 mg of nifedipine also resulted in a significant but more profound decrease of the basal SO pressure from 47.1 to 17.3 mmHg as well as in a decrease of amplitude, duration, and frequency of the phasic contractions. Neither placebo nor 10 or 20 mg of nifedipine has any effect on the sequence of phasic contractions. In summary, nifedipine may have a possible therapeutic role in the treatment of SO dyskinesia.

Adult↗
PubMed1988

Papillary stenosis.

The present state of papillary stenosis is reviewed. ERCP manometry has become the most important means of evaluating sphincter of Oddi dynamics. Pressure measurements in the sphincter segment appear useful to differentiate patients with sphincter of Oddi dysfunction from patients with an organic stenosis. The author's experience with sphincter of Oddi manometry, with endoscopic sphincterotomy and hydrostatic balloon dilation of the sphincter of Oddi, and the results of an international inquiry, are presented.

Ampulla of Vater↗
PubMed1987

Endoscopic cholangiopancreatography in the infant: evaluation of a new prototype pediatric duodenoscope.

The usefulness of a new pediatric duodenoscope PJF in the diagnosis of neonatal cholestasis was studied in 23 infants with ages ranging from 19 to 150 days. In 22 of 23 infants the papilla was cannulated. In 13 of 14 neonates (93%) with neonatal hepatitis, the common bile duct was opacified and biliary atresia was excluded. In one of two neonates with choledochal cyst, the common bile duct was demonstrated. In six of seven neonates (86%) with biliary atresia, only the pancreatic duct was demonstrated and the diagnosis was suspected. Although absence of a common bile duct opacification does not rule out biliary atresia, ERCP with the new duodenoscope proved to be most useful in the diagnosis of normal biliary tree and served to avoid unnecessary surgery in most infants with neonatal cholestasis.

Biliary Atresia↗
PubMed1987

Late results in patients with Schatzki ring treated by endoscopic electrosurgical incision of the ring.

In 17 ambulatory patients with severe intermittent dysphagia an endoscopic electrosurgical radial incision of a Schatzki ring was made with a modified straight retractable sphincterotome. The incision was successfully accomplished with immediate relief of dysphagia in all patients. Fourteen patients remain asymptomatic with a mean follow-up of 46 months after the first treatment. Three patients required a second incision and they have been asymptomatic for more than 24 months. There was one mild bleeding episode. Endoscopic electrosurgical incision of the Schatzki ring is an effective therapeutic modality in selected patients.

Adult↗