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Biomedical subjects

R R Dozois

Publications and source records attributed to R R Dozois.

At least 127 records · Page 7Linked to original sources
PubMed1985

Motility of the small intestine after proctocolectomy and ileal pouch-anal anastomosis.

Though the mechanisms of continence after proctocolectomy and ileal pouch-anal anastomosis have been studied, functions of the small intestine have received little attention. However, frequent stools and urgency plague some patients who are otherwise quite continent. Motility of the jejunum and ileum was assessed in eight patients with ulcerative colitis who were studied 4 to 24 months after proctocolectomy and ileal pouch-anal anastomosis; these findings were compared to those in six healthy volunteers. Continuous manometric recordings from the small bowel were obtained in both groups for 16 to 23 hours of fasting; postprandial recordings were made for 6 hours following a mixed meal (800 kcal, 20% protein, 40% fat, 40% carbohydrate) in the ileoanal patients. The duration, velocity of propagation, and periodicity of the migrating motor complex did not differ between the groups (P greater than 0.05). Discrete bursts of clustered contractions were recorded from all of the controls and in five of eight patients. Likewise, we recorded from all controls and five of eight patients large amplitude, prolonged waves of pressure which propagated distally. However, in controls these large amplitude waves were confined to the terminal ileum, but in patients these were detected in the jejunoileum, up to 125 cm proximal to the ileal pouch. We conclude that jejunoileal motility is not greatly altered by proctocolectomy with ileal pouch-anal anastomosis. However, the appearance of the large amplitude, rapidly propagating waves in the proximal jejunoileum after operation may be a response to increased storage within and distention of the distal bowel.

Adult↗
PubMed1985

Ileal "J" pouch-anal anastomosis. Clinical outcome.

One hundred eighty-eight patients undergoing abdominal colectomy with distal mucosal proctectomy and endorectal ileal pouch-anal anastomosis were reviewed to assess long-term functional results and to identify factors that might influence them. There was no postoperative mortality, but 10 patients (5.3%) required permanent ileostomy because of postoperative complications or the development of unsuspected Crohn's disease. Immediate postoperative complications, including pelvic sepsis, small bowel obstruction requiring surgery, anastomotic stricture, and ileostomy dysfunction, were observed in 11%, 9%, 14% and 9% of patients, respectively. No males were impotent but nine (9%) developed retrograde ejaculation. Pouchitis occurred in 8% of patients. Among 157 patients assessed at least 60 days after ileostomy closure (mean +/- SD, 375 +/- 216 days), all evacuated their neorectum spontaneously, and stool frequency was 6.0 +/- 2.6 daily and 1.2 +/- 1.3 nightly. While continence was generally good, 2.5% of patients during waking hours and 4.5% during sleep had occasional frank soilage. Moreover, seepage was noted in 25 and 47% of patients during daytime and nighttime, respectively. Both stool frequency and degree of continence improved with time. Patients less than 50 years of age and those with polyposis coli had fewer stools and better continence than those older than 50 or those with ulcerative colitis. It is concluded that ileal "J" pouch-anal anastomosis can be performed safely and will provide acceptable anorectal function without late deterioration.

Adolescent↗
PubMed1984

The endorectal ileal pouch-anal anastomosis. Current clinical results.

One hundred thirteen patients with either chronic ulcerative colitis (108 patients) or familial polyposis coli (five patients) received an ileal J pouch-anal anastomosis after sphincter-saving proctocolectomy. There were no postoperative deaths. Leaks (radiologic and/or clinical) from the pouch or ileoanal anastomosis occurred in 14 per cent of patients. Small-bowel obstruction, requiring operative correction, occurred in 7 per cent and 3 per cent, respectively, of patients after either proctocolectomy or closure of the loop ileostomy. All 66 patients whose diverting ileostomy had been closed for at least three months could defecate spontaneously and their mean (+/- SE) stool frequency per 24 hours was 9.0 +/- 1 at one month and 5.9 +/- at 12 months. Major fecal incontinence was observed in 3 per cent of patients, and two patients eventually required a permanent ileostomy. The ileal J pouch-anal anastomosis has become our procedure of choice in selected patients who require proctocolectomy.

Adolescent↗
PubMed1984

Influence of sigmoid resection on progression of diverticular disease of the colon.

The surgeon is frequently confronted with the problem of how much colon to resect when operating on patients with colonic diverticulosis or diverticulitis. Two questions arise: will diverticulosis progress in the proximal colon if only the sigmoid is removed, and will diverticulitis recur in the more proximal diverticula? To evaluate these potential problems, the histories were reviewed of 61 patients who had elective sigmoid resection for diverticular disease and who had barium enema examinations before operation, early during the postoperative period, and at least five years later. Progression of diverticulosis was noted in only nine (14.7 per cent) patients on repeat barium-enema examination five to nine years after resection; the progression was noted to be minimal in all nine. Seven patients (11.4 per cent) had signs and symptoms of recurrent diverticulitis. Only three patients demonstrated progression of diverticulosis and recurrent diverticulitis. We see no benefit in resecting all of the diverticula-bearing colon after adequate sigmoid resection, as there is minimal progression in the diverticular process and the risk of recurrence is low.

Adult↗
PubMed1984

Toxic megacolon: ultimate fate of patients after successful medical management.

The clinical course and ultimate outcome in 38 patients with toxic megacolon who were successfully treated nonoperatively has been reviewed. Thirty-two patients had ulcerative colitis and 6 had Crohn's disease. Follow-up was complete and ranged from 3 to 22 years (average 13 years). Eleven of 38 patients (29 percent) eventually suffered second episode of fulminant acute colitis or recurrent toxic megacolon. Ultimately, a total of 18 patients (47 percent) underwent colon resection, which was performed on an emergency or urgent basis in 15 patients. A modified Visick classification was employed to assess the long-term results of medical therapy in the entire group, in patients showing improvement within 48 or 72 hours, in patients 30 years or younger, in patients whose initial presentation of inflammatory bowel disease was toxic megacolon, and in patients with ulcerative colitis as opposed to Crohn's disease. The results were equally poor for all subgroups, and they have strengthened our opinion that medical management of toxic megacolon should be regarded almost exclusively as preparation for imminent surgery.

Adolescent↗
PubMed1984

Canine interdigestive and postprandial gallbladder motility and emptying.

The objectives of this study were to characterize intraluminal gallbladder pressure during fasting and postprandially and to determine the relationships between its intraluminal pressure and emptying. Conscious dogs, with chronic indwelling gallbladder and duodenal catheters to measure pressures and infuse nonabsorbable markers, were used to quantify intraluminal pressures and emptying of gallbladder contents and bile into the duodenum during interdigestive and postprandial periods. During the interdigestive period, a brief rise in intragallbladder pressure followed by the flow of bile and 20% of gallbladder marker into the duodenum occurred only during phase II (a period of irregular duodenal contractility preceded by absent duodenal activity, phase I, and followed by a period of regular duodenal contractility, phase III). We suggest that intragallbladder pressure increased secondary to contraction of the gallbladder against a closed sphincter of Oddi and its decline to base line was accompanied by sphincter relaxation, partial gallbladder emptying, and flow of bile into the duodenum. Postprandially, intragallbladder pressure transiently increased and was followed by an isotonic phase lasting 74 +/- 12 min that ended with the onset of rhythmic large-amplitude pressure elevations that continued for 5.1 +/- 1.6 h. Gallbladder emptying was most rapid during the first 30 min postprandially and was completed by 2 h. Thereafter, large-amplitude gallbladder pressure elevations may prevent gallbladder filling and divert hepatic bile into the duodenum until return of the fasting pattern.

Animals↗
PubMed1984

Prognostic factors in pancreatic abscess.

Pancreatic abscess is a highly lethal sequela of pancreatitis. The purpose of this study was to identify clinical and laboratory factors associated with the antecedent episode of pancreatitis or at the time of manifestation of a pancreatic abscess and factors related to its treatment that might have prognostic significance. The records of 66 consecutive patients with pancreatic abscess seen between 1966 and 1980 were reviewed. Factors adversely affecting survival included: severity of precipitating pancreatitis (p less than 0.03); sepsis and pulmonary dysfunction (p less than 0.05); and persistent postoperative sepsis (p less than 0.001). All four patients who were treated nonsurgically died. Of 62 patients treated surgically, 80% experienced serious complications, 31% required reoperations, and 40% died. No single surgical procedure, including marsupialization, proved to be superior. Surgical drainage offers the only possibility of survival for patients with pancreatic abscess. More thorough elimination of all focuses of infection is required, however, to reduce the high morbidity and mortality rates associated with persistent postoperative sepsis.

Abscess↗
PubMed1983

Straight ileoanal anastomosis v ileal pouch--anal anastomosis after colectomy and mucosal proctectomy.

The postoperative results of 50 patients who underwent straight ileoanal anastomosis after total colectomy and mucosal proctectomy were compared with those of 74 patients who underwent ileal pouch--anal anastomosis. No deaths occurred. Of the straight ileoanal anastomoses, 32% failed because of sepsis or diarrhea and necessitated abdominal ileostomy; only 1.3% failed in the pouch-anal group (P less than .05). Stool frequency among patients followed up for three months or more (straight ileoanal, n = 30; pouch-anal, n = 33) was less in the pouch-anal group (mean +/- SEM, 7 +/- 1 stools per 24 hours) than in the straight ileoanal group (11 +/- 1/24 hr, P less than .01). Major nocturnal incontinence was also less in the pouch-anal group than in the straight ileoanal group (0% v 20%), and patient satisfaction was better, as measured on a scale of 1 (very poor functional result) to 10 (excellent result) (pouch-anal score, 9; straight ileoanal score, 6; P less than .02). We concluded that ileal pouch-anal anastomosis resulted in less diarrhea, better continence, and an improved quality of life when compared with straight ileoanal anastomosis.

Adult↗
PubMed1983

A canine model for the study of gastric secretion and emptying after a meal.

Our aim was to develop a chronic canine model that would serve for the simultaneous measurements of postprandial gastric secretion and emptying by a double-marker dilution technique without artificially interfering with intragastric pH. A constant duodenal perfusion of a nonabsorbable marker allowed determination of luminal flow and total recovery of a second marker ingested with a meal. By calculating the amount of meal marker remaining in the stomach and its dilution (by repeat gastric sampling), we could determine the volume of gastric contents. Acid concentration in gastric samples was measured by titration ex vivo, and gastric acid content was calculated by multiplying the volume of gastric contents by titratable acidity. In this model, net acid gain at each sampling interval indicates acid output. Acid and volume losses are equivalent to duodenal acid load ad emptying rate, respectively. The method has been validated by virtually abolishing the endogenous secretion of acid (by intravenous infusion of cimetidine) and the calculation of known volumes and concentrations of acid exogenously instilled in the animal's stomach. Our results indicate that this is an accurate and practical method for the physiologic measurement of postprandial gastric function in dogs. Further, these studies substantiate the validity of the assumptions upon which the human double-marker method was based.

Animals↗
PubMed1983

Adenocarcinoma of the rectum arising in a hamartomatous polyp in a patient with Peutz-Jeghers syndrome.

The malignant potential of the hamartomatous polyps in Peutz-Jeghers syndrome has been debated. Although this is a very rare event, these polyps can undergo carcinomatous transformation, as demonstrated by this report of a 37-year-old man with well-documented Peutz-Jeghers syndrome who developed an invasive grade 2 adenocarcinoma on the surface of a hamartomatous polyp in the rectum.

Adenocarcinoma↗
PubMed1983

Surgical treatment of recurrent peptic ulcer disease.

One hundred twenty patients in whom recurrent peptic ulcer developed after various surgical procedures for primary duodenal ulcer were operated on at the Mayo Clinic between 1970 and 1975. The postoperative mortality rate was 3.3% for all cases, 0.9% for elective cases, and 23% for the 13 patients who required emergency surgical care. The mean hospital stay was 13 days, and postoperative complications developed in 25 patients (20%). Approximately 70% of the patients had excellent or good results, whereas the rest had significant postoperative sequelae, including 8.4% (9 patients) in whom rerecurrent ulceration developed. When remedial surgery for recurrent ulcer consisted of vagotomy and distal subtotal gastrectomy (35 patients) after previous vagotomy and drainage procedure (21 patients), subtotal gastrectomy (three patients), vagotomy and hemigastrectomy (eight patients), or gastroenterostomy alone (three patients), there were no operative deaths, 74% of 27 patients available for at least a 5-year follow-up had excellent or good results, and rerecurrent ulceration developed in only one patient. These results indicate that vagotomy and resection is a satisfactory operation for recurrent peptic ulcer and that the long-term results after this operation compare favorably with those reported for cimetidine therapy.

Adult↗
PubMed1983

A clinico-physiological comparison of ileal pouch-anal and straight ileoanal anastomoses.

The ileal pouch-anal anastomosis improves clinical results after colectomy and mucosal proctectomy compared to the straight ileoanal anastomosis. The question was what physiologic changes brought about by the pouch led to the improvement. Among 124 patients who had had ileoanal anastomosis, 25 volunteered for a detailed clinicophysiologic evaluation. Fourteen had had the ileal pouch-anal operation a mean of 8 months previously, and 11 had the straight ileoanal operation a mean of 25 months previously. Both groups of patients had satisfactory anal sphincter resting pressures (mean +/- SEM, pouch = 68 +/- 8 cm H2O, straight = 65 +/- 9 cm H2O, p greater than 0.05) and neorectal capacities (pouch = 278 +/- 26 ml, straight = 233 +/- 36 ml, p less than 0.05), and all could evacuate spontaneously. However, the pouch patients had a more distensible neorectum (delta V/delta P pouch = 9.5 +/- 1.3 ml/cm H2O, straight = 4.9 +/- 0.9 ml/cm H2O, p less than 0.05) and smaller amplitude neorectal contractions (pouch = 36 +/- 5 cm H2O, straight = 90 +/- 13 cm H2O; p less than 0.05). We concluded that the pouch-anal anastomosis increased the distensibility of the neorectum and decreased its propulsive drive, and so improved clinical results.

Adult↗
PubMed1983

Factors influencing metabolism of arachidonic acid in guinea pig gastric mucosa.

The metabolism of [14C]arachidonic acid in whole homogenates of gastric corpus mucosa in the guinea pig was characterized. Identity of labeled products was validated by comigration against standards in multiple chromatographic systems and by selective synthesis inhibition. At near-physiological conditions, homogenates converted arachidonic acid to the cyclooxygenase products prostaglandins F2, E2, and D2, 6-keto-prostaglandin F1 alpha, and thromboxane B2 (in descending order of magnitude) and to a lipoxygenase product cochromatographing with 12-hydroxyeicosatetraenoic acid. However, dramatic qualitative and quantitative changes in this product profile were noted with relatively small changes in incubation temperature, substrate concentration, and especially pH. Whole homogenates generated more prostaglandin and in different proportions than did the microsomal fraction from an equal mass of mucosa. No catabolism of prostaglandin products was observed in whole homogenates. Tissue preparation and storage also influenced prostaglandin synthesis activity. These in vitro observations may have important implications for future studies of prostaglandin generation in small gastric mucosal biopsies.

6-Ketoprostaglandin F1 alpha↗
PubMed1983

Duodenal prostaglandin synthesis and acid load in health and in duodenal ulcer disease.

We sought to test the hypothesis that duodenal ulcer disease results from an imbalance between duodenal acid load, an injurious force, and mucosal prostaglandin generation, a protective factor. Ten patients with duodenal ulcer and 8 healthy controls were studied. The duodenal acid load after an amino acid soup was quantified by a double-marker technique. Mucosal biopsy specimens were taken endoscopically from the duodenal bulb before and after the test meal. Prostaglandin synthesis activity was measured by incubating biopsy homogenates in excess [14C]arachidonic acid. Although mean duodenal acid load was higher in duodenal ulcer, ranges overlapped. Neither the qualitative nor quantitative profile of mucosal prostaglandin synthesis activities differed significantly between test groups. Prostaglandin synthesis activities, however, tended to increase post cibum in controls, but change little or decrease in duodenal ulcer. Only by comparing the responses with a meal of both parameters together (duodenal acid load and the change in prostaglandin synthesis activities) was there complete or nearly complete separation of duodenal ulcer from controls. Greatest discrimination was observed with prostacyclin (6-keto-PGF1 alpha). We conclude that in health, mucosal prostaglandin generation in the duodenum is induced post cibum in relation to duodenal acid load; this may be a physiologic example of adaptive cytoprotection. In duodenal ulcer there may be a defect in such a mechanism.

Adult↗
PubMed1983

Predicting outcome after endorectal ileoanal anastomosis.

The aim of this study was to determine whether anorectal manometry could predict clinical outcome after closure of a diverting ileostomy made at the time of colectomy, mucosal proctectomy and endorectal ileoanal anastomosis for chronic ulcerative colitis. Twenty-two patients were studied, 6 with ileoanal anastomosis and 16 with ileal pouch-anal anastomosis. Resting anal sphincter pressures and pressure-volume curves (compliance) of the neorectum were assessed before the diverting ileostomy was closed and results were correlated with frequency and leakage of stools 1 month after closure. Before stomal closure, the mean (+/- standard error of the mean) resting sphincteric pressure was 44 +/- 5 cm H2O, while neorectal compliance was 2.3 +/- 0.3 ml/cm H2O. One month later daily stool frequency was 12 +/- 1, while severe leakage occurred in four patients during the day and in eight at night. The greater the sphincteric pressure and the compliance, the fewer were the number of stools per day (p less than 0.01). When pressure and compliance were considered together as an index of anorectal function, the correlation of stool frequency and leakage was even stronger (p less than 0.001). The authors conclude that anorectal manometry can predict early clinical outcome after ileoanal anastomosis.

Adolescent↗
PubMed1983

Development and application of methodology for assessing the role of lysosomes in experimental ulcerogenesis in the guinea pig.

In order to determine if lysosomes are causally involved in gastric ulcerogenesis, we (a) systematically characterized homogenization techniques and assay conditions for measurement of lysosomal enzymes in guinea pig gastric mucosa, and (b) assessed the relationship among histamine-induced gastric erosions, lysosomal enzyme activities, and the integrity of lysosomal membranes. We developed procedures that yielded tissue homogenates of gastric mucosa in which a majority of cells had been disrupted, but at least two-thirds of the lysosomes were preserved. We also demonstrated that two lysosomal enzymes from gastric mucosa, N-acetyl-beta-glucosaminidase and beta-glucuronidase, had acid pH optima and activities that were linear with time, mucosal protein, and substrate concentration, and exhibited Michaelis-Menten kinetics. Moreover, using isopycnic centrifugation of light mitochondrial fractions on continuous and discontinuous sucrose gradients, we showed that Triton WR-1339, a non-ionic detergent known to accumulate in hepatic cells, also accumulates in gastric mucosal cell lysosomes, causing a decrease in their density and an increase in their fragility. Finally, we found no correlation between histamine-induced gastric erosions and the integrity of gastric mucosal cell lysosomes; pretreatment of guinea pigs with Triton WR-1339 increased the fragility of gastric cell lysosomes, but did not enhance the ulcerogenic effect of histamine. Our findings do not support a role for gastric cell lysosomes in histamine-induced gastric mucosal injury.

Acetylglucosaminidase↗