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Biomedical subjects

M J Collen

Publications and source records attributed to M J Collen.

At least 37 records · Page 2Linked to original sources
PubMed1993

Is there a role for upper gastrointestinal endoscopy in the evaluation of patients with occult blood-positive stool and negative colonoscopy?

OBJECTIVE: To determine the role of upper gastrointestinal endoscopy in the clinical investigation of patients with occult blood-positive and negative colonoscopy. METHODS: This is a retrospective study of 211 consecutive patients who were investigated by upper gastrointestinal endoscopy for occult blood-positive stool and negative colonoscopy. Patients were categorized into four groups: asymptomatic (n = 117), symptomatic (n = 37), severe anemia (hemoglobin < 10 g/dl) (n = 33), and incomplete (CBC not obtained or insufficient documentation regarding the presence or absence of symptoms) (n = 24). RESULTS: Eighty-eight of the 211 patients (42%) had abnormal upper gastrointestinal endoscopic findings: 43% of the "asymptomatic" group, 35% of the "symptomatic" group, 45% of the "severe anemia" group, and 42% of the "incomplete" group. The number of patients with abnormal upper gastrointestinal findings increased with age (p = 0.0002). Furthermore, there was a significant difference in upper gastrointestinal lesions between the patients who were 60 yr of age or older, and the patients less than 60 yr of age: 51% compared to 22% (p = 0.00003). All upper gastrointestinal endoscopic findings were benign, with 53 of the 88 patients (60%) having erosive gastritis. However, only 25 of those 88 patients (28%) had a lesion for which a specific treatment was available. CONCLUSIONS: Upper gastrointestinal endoscopy in patients with occult blood-positive stool and negative colonoscopy has a very low yield for significant lesions, not only from a therapeutic standpoint, but also for detection of malignant lesions. Prospective studies are needed to determine which specific groups of patients deserve further investigation.

Aged↗
PubMed1993

Utility of endoscopic retrograde cholangiopancreatography in the evaluation of idiopathic abdominal pain.

We investigated the role of endoscopic retrograde cholangiopancreatography in 86 consecutive patients with idiopathic chronic or recurrent abdominal pain. There were 18 males and 68 females with a mean age of 48 yr. Forty patients (47%) had previous cholecystectomy. Patients were divided into two groups: group I (normal serum alkaline phosphatase and total bilirubin) (n = 52), and group II (elevated serum alkaline phosphatase and/or total bilirubin) (n = 34). Pancreatograms were normal in all patients, including five with pancreas divisum. Cholangiograms were abnormal in 10 of the 34 patients in group II (30%), and in only three of the 52 patients in group I (6%) (p = 0.003). Bile duct stones were present in 18% of the patients in group II, and in none of the patients in group I (p = 0.003). Of the 40 post-cholecystectomy patients, four patients had bile duct stones and five had common bile duct dilation without stones. However, no stones were found in any post-cholecystectomy patients with normal liver tests. Of the 46 patients with gallbladder in situ, two patients with abnormal liver tests had common bile duct stones and two patients had common bile duct dilation without stones. These results indicate that, among patients with idiopathic abdominal pain, cholangiography should be performed primarily in those with abnormal liver tests; however, further investigation with pancreatography is unnecessary.

Abdominal Pain↗
PubMed1992

Biphasic solid and liquid gastric emptying in normal controls and diabetics using continuous acquisition in LAO view.

The purpose of this study was to investigate the various phases of gastric emptying using a dual-isotope liquid-solid meal ([99mTc]SC egg sandwich and [111In]DPTA in water) and continuous acquisition in the left anterior oblique view. The study groups consisted of 10 normal controls and 20 diabetics with symptoms suggestive of diabetic gastroparesis. Solid-phase emptying in both groups almost always had a lag phase followed by linear emptying. Liquid-phase emptying was biexponential in 4/10 normals and 12/20 diabetics, with a short early rapid emptying rate (mean T1/2 = 48 min in normals and 79 min in diabetics). Solid emptying was delayed in 10, normal in eight, and rapid in two diabetics. Liquid emptying was delayed in 9/10 diabetics who had delayed solid emptying. Diabetics as a group had a significantly delayed solid lag phase (P less than 0.025), rate of emptying (P less than 0.05) and percent emptying at 90 min (P less than 0.025) compared to normal controls. Diabetic liquid emptying was also significantly delayed (P less than 0.025). The second component of liquid emptying strongly correlated with the solid rate of emptying (r = 0.826 in normals and 0.855 in diabetics). Continuous acquisition of gastric emptying studies in the LAO view has allowed us to better define the various phases of solid and liquid gastric emptying.

Adolescent↗
PubMed1992

Comparison of omeprazole and ranitidine in treatment of refractory gastroesophageal reflux disease in patients with gastric acid hypersecretion.

Secretion of gastric acid and volume, serum gastrin concentration, and ambulatory 24-hr esophageal pH monitoring were evaluated prospectively in 12 patients with idiopathic gastric acid hypersecretion (basal acid output greater than 10.0 meq/hr) undergoing treatment for refractory chronic long-standing pyrosis. Treatment lasted six months and consisted of three months of ranitidine (mean 2150 mg/day, range 1200-3000 mg/day), followed by three months of omeprazole (mean 33 mg/day, range 20-60 mg/day). Both ranitidine and omeprazole significantly reduced gastric acid output (P less than 0.001) and gastric volume output (P less than 0.001) compared to a basal evaluation and resulted in complete disappearance of pyrosis. Total reflux time (percent 24 hr intraesophageal pH less than 4) was significantly reduced by ranitidine (P less than 0.02) and omeprazole (P less than 0.001) compared to basal evaluation; however, the effects of omeprazole were significantly greater than ranitidine (P less than 0.05). Omeprazole caused a significant increase in serum gastrin concentration compared to both basal and ranitidine (P less than 0.05). Endoscopically documented erosive esophagitis was present in nine of the 12 patients, and seven of the 12 patients had Barrett's epithelium. All 12 patients had complete resolution of pyrosis and healed esophagitis by six months, but no significant endoscopic regression was observed in the extent of Barrett's epithelium. No side effects occurred with these high doses of ranitidine or omeprazole. These results indicate that high-dose ranitidine and omeprazole are effective therapy for refractory gastroesophageal reflux disease. However, with omeprazole, total reflux times are reduced more than with ranitidine, often into the normal range.(ABSTRACT TRUNCATED AT 250 WORDS)

Barrett Esophagus↗
PubMed1992

Correlation between basal acid output and daily ranitidine dose required for therapy in Barrett's esophagus.

We prospectively evaluated basal gastric acid secretion in 42 consecutive patients with Barrett's esophagus to determine the optimal dose requirement for an H2-receptor antagonist in relation to the gastric acid secretory status of each patient. All patients with Barrett's esophagus had pyrosis and 31 of the 42 patients had erosive esophagitis. Mean extension of Barrett's epithelium was 6.9 cm (range 2-17 cm). Mean basal acid output for the patients with Barrett's esophagus was 8.0 +/- 5.2 meq/hr, which was significantly different compared to a group of 65 normal subjects with mean basal acid output of 3.0 +/- 2.7 meq/hr (P less than 0.001). There was no correlation between basal acid output and extension of Barrett's epithelium. All patients with Barrett's esophagus were treated with ranitidine, with 24 requiring standard-dose (300 mg/day) and 18 requiring increased doses (mean 1170 mg/day, range 600-2400 mg/day) for complete healing of esophagitis and disappearance of pyrosis. There was a significant correlation between basal acid output and daily ranitidine dose required for therapy (r = 0.52, P less than 0.001). Fifteen of the 42 patients with Barrett's esophagus (36%) had gastric acid hypersecretion. There was a significant association between gastric acid hypersecretion defined as a basal acid output of greater than 10.0 meq/hr and a requirement for increased daily ranitidine doses (greater than 300 mg/day) (P less than 0.0002). No side effects occurred with any of these high doses of ranitidine. We conclude that as a group, patients with Barrett's esophagus have significantly higher basal acid outputs than normal subjects and many require increased therapeutic doses of ranitidine.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Malignant fibrous histiocytoma metastatic to the colon presenting as a lower gastrointestinal bleed.

Primary and metastatic malignant fibrous histiocytoma of the alimentary tract is uncommon, even though it is the most frequently diagnosed malignant soft tissue tumor in adults. In this report, we describe a patient with a left gluteal malignant fibrous histiocytoma who had intermittent melena and hematochezia attributed to colon metastases, 1 yr after surgical removal of the gluteal sarcoma.

Aged↗
PubMed1991

Definition for idiopathic gastric acid hypersecretion. A statistical and functional evaluation.

Zollinger-Ellison syndrome and other gastric acid hypersecretory states in which a specific etiology is identified are defined as a basal acid output of greater than 15.0 meq/hr. To determine the level of basal acid output that defines idiopathic gastric hypersecretion, basal acid outputs were investigated in normal subjects and patients with duodenal ulcers, and functional and statistical definitions for idiopathic gastric acid hypersecretion were developed. Sixty-five normal subjects were evaluated to define idiopathic gastric acid hypersecretion on a statistical basis, and 22 patients with refractory duodenal ulcers were evaluated to define idiopathic gastric acid hypersecretion on a functional basis. Mean basal acid output for the 65 normal subjects was 3.0 +/- 2.7 meq/hr. Even though the mean basal acid output for the group of 28 normal male subjects was slightly higher than for the group of 37 normal female subjects, the groups were not significantly different. The 95% confidence interval around the mean basal acid output for all normal subjects was 2.4-3.7 meq/hr, with little difference between the male and female groups. The mean basal acid output plus two standard deviations and the mean basal acid output plus three standard deviations for the 65 normal subjects were 8.4 meq/hr and 11.1 meq/hr, respectively. Of 109 patients with active duodenal ulcers treated for eight weeks with standard doses of antisecretory medication, 22 showed no healing as documented by endoscopy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Gastric acid hypersecretion in refractory gastroesophageal reflux disease.

We prospectively evaluated gastric acid output (mEq/h), gastric volume output (ml/h), ambulatory 24-h esophageal pH monitoring, and the endoscopic appearance of the esophagus in 23 patients undergoing treatment of chronic long-standing pyrosis. Twelve of these 23 individuals (52%) remained symptomatic after 3 mo of standard antisecretory treatment with ranitidine, 150 mg twice daily. When compared with initial responders, those patients who did not experience complete symptomatic relief on therapy had significantly higher basal acid output (p less than 0.001), basal volume output (p less than 0.02), and basal upright (but not supine) reflux time (p less than 0.05). Nine of the 12 patients who did not respond to initial treatment had gastric acid hypersecretion (basal acid output greater than 10 mEq/h), and 10 of the 12 had Barrett's epithelium compared with only 1 patient in the initial-responder group (p less than 0.001). All 12 nonresponders were treated for an additional 3 mo with increased doses of ranitidine (mean, 1280 mg/day; range, 600-1800 mg/day), and complete disappearance of pyrosis occurred in 10 of the 12, although no significant endoscopic regression was observed in the extent of the underlying columnar mucosa in those with Barrett's esophagus over the 6-mo duration of the study. A significant correlation was shown between the daily ranitidine dose required to eliminate symptoms and the pretreatment basal acid output (r = 0.81, p less than 0.001); gastric acid output had to be almost totally suppressed (i.e., less than 1 mEq/h) for pyrosis to disappear completely. No side effects occurred with any of these high doses of ranitidine. We conclude that a subgroup of patients with long-standing symptomatic gastroesophageal reflux disease who do not respond to standard ulcer-healing doses of histamine2-receptor antagonists are hypersecretors of basal gastric acid and require increased acid-suppressive therapy. Many of these individuals also have underlying Barrett's epithelium.

Adolescent↗
PubMed1990

The effect of Zollinger-Ellison syndrome and omeprazole therapy on gastric oxyntic endocrine cells.

In 1983, all trials of omeprazole in humans were stopped because rats given the drug developed gastric endocrine cell hyperplasia and carcinoid tumors. Further studies in rats showed that drug-induced achlorhydria and hypergastrinemia caused these changes. Because data in humans are limited, we compared the numbers of endocrine cells, as judged by silver staining (argyrophilia), in the gastric mucosa of patients with Zollinger-Ellison syndrome, who are hypergastrinemic, and in normogastrinemic patients with idiopathic acid-peptic diseases. In addition, we analyzed the number of gastric endocrine cells in patients with Zollinger-Ellison syndrome given omeprazole for up to 3 years. Patients with Zollinger-Ellison syndrome had 15.7% +/- 6.9% argyrophil cells in biopsies of gastric oxyntic mucosa, and patients with idiopathic acid-peptic disease had 7.8% +/- 2.3% (P less than 0.01). In patients with Zollinger-Ellison syndrome, the percentage of argyrophil cells was not related to serum gastrin concentration, duration of symptoms, time since diagnosis, basal or maximal acid output, extent of tumor, or age. There was a tendency for patients with multiple endocrine neoplasia type 1 to have a greater percent of argyrophil cells than patients with sporadic Zollinger-Ellison syndrome. Considering the biopsies from both normogastrinemic and hypergastrinemic patients, there was a significant relationship between the percentage of argyrophil cells and the serum concentration of gastrin (P less than 0.01). Patients with Zollinger-Ellison syndrome given omeprazole for up to 3 years developed no significant changes in percentage of argyrophil cells, no carcinoid tumors, and no changes in serum concentrations of gastrin. The present study shows that patients with Zollinger-Ellison syndrome have an increased percentage of argyrophil cells in oxyntic mucosa and that omeprazole does not increase this percentage. In periods of up to 3 years, omeprazole had no effects on gastric morphology in patients with Zollinger-Ellison syndrome.

Adult↗
PubMed1990

Serum amylase in patients with renal insufficiency and renal failure.

Results vary with regard to the upper limits of serum amylase seen in patients with renal failure, and very little has been reported with patients with renal insufficiency not yet requiring dialysis. To determine the level of serum amylase elevation in renal insufficiency and renal failure, we determined serum amylase values in 128 subjects with creatinine clearances less than 90 ml/min. Serum amylase remained in the normal range when creatinine clearance was greater than 50 ml/min, and did not become elevated until creatinine clearance was less than 50 ml/min. The highest serum amylase recorded in the absence of acute pancreatitis was 503 IU/L (normal, less than 128 IU/L). Serum lipase and trypsin values paralleled those for serum amylase; values remained normal when creatinine clearance was greater than 50 ml/min, and were normal or elevated when creatinine clearance was less than 50 ml/min. These results indicate that elevations of serum amylase (i.e., amylase greater than 128 but less than 500 IU/L) in asymptomatic patients with impaired renal function are not evident until creatinine clearances fall below 50 ml/min, and probably do not represent acute pancreatitis.

Acute Disease↗
PubMed1989

Refractory duodenal ulcers (nonhealing duodenal ulcers with standard doses of antisecretory medication).

To evaluate possible differences between patients with refractory duodenal ulcers and those with duodenal ulcers that respond to standard doses of antisecretory medications, we determined basal acid outputs by nasogastric suction and daily smoking histories in 75 patients with endoscopically documented active duodenal ulcers. Patients were treated for at least eight weeks with standard doses of antisecretory medications and endoscopic healing or nonhealing was documented. Fifty-five patients that had complete healing of their duodenal ulcers had a mean basal acid output of 6.6 +/- 5.3 meq/hr, and 18/55 had daily cigarette smoking histories, whereas 20 patients that had nonhealing duodenal ulcers had a mean basal acid output of 20.0 +/- 9.6 meq/hr, and 8/20 had daily cigarette smoking histories. There were no significant differences between the two groups with regard to age, duodenal ulcer size, or cigarette smoking history. However, there were significant differences in male-female ratio (P less than 0.02) and in mean basal acid output (P less than 0.001), and all patients with nonhealing duodenal ulcers had basal acid outputs of greater than 10.0 meq/hr. Patients with nonhealing duodenal ulcers were treated with increased doses of ranitidine, mean 675 mg/day (range 600-1200 mg/day), and all had complete healing endoscopically documented. These results indicate that patients treated with standard doses of antisecretory medications with nonhealing duodenal ulcers have increased basal acid outputs of greater than 10.0 meq/hr, and the duodenal ulcers heal with increased doses of antisecretory medication.

Adult↗
PubMed1989

Basal gastric acid secretion in nonulcer dyspepsia with or without duodenitis.

Nonulcer dyspepsia with or without duodenitis and duodenal ulcer disease are often considered to be a spectrum of the same acid-peptic process. Some reports evaluating basal gastric acid secretion in nonulcer dyspepsia and duodenal ulcer disease have supported that impression; however, results from different studies have been mixed. In order to compare basal gastric secretory profiles in nonulcer dyspepsia and duodenal ulcer disease, we determined basal acid outputs in 66 consecutive patients with the diagnosis of nonulcer dyspepsia. All patients with nonulcer dyspepsia had at least a three-month history of epigastric abdominal pain, and all had negative upper gastrointestinal endoscopies except for 14 with duodenitis. The 66 patients with nonulcer dyspepsia were compared to 40 asymptomatic normal subjects and 114 patients with endoscopically documented duodenal ulcer disease. There was no significant difference in mean basal acid output among all 66 patients with nonulcer dyspepsia (2.9 +/- 2.7 meq/hr), the group of normal subjects (3.2 +/- 2.7 meq/hr), the 14 patients with nonulcer dyspepsia with duodenitis (3.0 +/- 2.1 meq/hr), and the 52 patients with nonulcer dyspepsia without duodenitis (2.9 +/- 2.9 meq/hr). However, mean basal acid output of the patients with duodenal ulcer disease (9.1 +/- 7.6 meq/hr) was significantly higher than all the other groups (P less than 0.001). The gastric acid secretory profiles determined in this study do not appear to support the view that nonulcer dyspepsia with or without duodenitis and duodenal ulcer disease are a spectrum of the same acid-peptide process.

Adult↗
PubMed1989

Use of endoscopic ultrasound in patients with esophageal motility disorders.

New technology has combined the endoscope with ultrasound in an effort to enhance the visualization of the gastrointestinal tract. With a modified standard endoscope that has an ultrasound transducer built into the tip, high frequency ultrasonic beams can be targeted in close proximity to existing lesions. This results in better quality resolution which enhances the evaluation of the targeted lesion. In addition, esophageal wall thickness can be evaluated and assessed as to its role in esophageal function.

Endoscopy↗
PubMed1989

Left anterior oblique projection and peak-to-scatter ratio for attenuation compensation of gastric emptying studies.

Compensation for soft-tissue attenuation is necessary for accurate quantitation of nuclear gastric emptying studies. We sought an attenuation compensation method that would require the acquisition of images from a single projection, thus allowing for continuous dynamic acquisition. We investigated the use of the left anterior oblique (LAO) projection and the peak-to-scatter ratio (P/S) method. Phantom studies indicated that the P/S was not only a function of the amount of overlying attenuating material but also a function of the activity in the small intestine. Two models for the P/S method were developed, one that considered the activity in the small intestine and one that did not. A series of 27 patients (21 for solid gastric emptying and six for liquid gastric emptying) were studied comparing the results using the geometric mean (GM) method with the two P/S methods, the LAO and the uncorrected anterior (ANT) projection. The uncorrected ANT view for solid gastric emptying underestimated the percent emptying at 60 min by approximately 7%. The P/S method did not adequately compensate for attenuation. The use of the LAO projection yielded results that were highly correlated and unbiased when compared to the GM method. Accurate estimates of liquid gastric emptying can be obtained without attenuation compensation.

Drinking↗