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Biomedical subjects

B M Taylor

Publications and source records attributed to B M Taylor.

At least 55 records · Page 3Linked to original sources
PubMed1985

Tone of canine ileocolonic junction: topography and response to phasic contractions.

We wished to define the physiology of the canine ileocolonic sphincter (ICS) and to examine function in relation to the region's anatomy. Prolonged recordings of tone at the ICS were made from seven dogs with isolated ileocolonic loops, and the effects of ileal and colonic distension on sphincteric tone were assessed. In acute experiments, pull-through pressures were measured at the ICS, and the location of the high-pressure zone was related to the region's anatomy. Basal tone at the ICS of approximately 30 cmH2O was confirmed; tone was augmented by colonic and ileal distension. The high-pressure zone was always centered on the anatomic ICS, but it extended into the adjacent ileum and colon for a total length of 2.0 cm (range 1.5-3.0 cm). Phasic contractions contributed to the maintenance of tone at the ICS, and a coordinated pattern of phasic contractions appears to contribute to the sphincteric properties of the region.

Animals↗
PubMed1984

Gastric influences on canine small intestinal myoelectric activity.

The aim was to determine whether the canine stomach modulates interdigestive and digestive small intestinal myoelectric activity. In four conscious dogs with electrodes implanted chronically on the duodenum and jejunum, enteric myoelectric activity was recorded during fasting and after feeding a 200-g liver meal. The dogs then underwent total gastrectomy and esophagoduodenostomy, after which they were restudied. Gastrectomy did not alter the pattern of the enteric interdigestive myoelectric complexes; the occurrence, period, duration of phase III, and consistency of distal propagation of enteric IMCs remained unchanged. Gastrectomy also preserved both the postcibal inhibition of the enteric IMCs and the postcibal induction of the fed myoelectric pattern in the small bowel. However, the onset of the fed pattern occurred more promptly after gastrectomy than before gastrectomy. We concluded that the pattern of canine duodenal and jejunal interdigestive myoelectric activity was largely independent of the stomach. The more rapid onset of the fed pattern with feeding postgastrectomy may relate to more rapid entry of chyme into the small intestine.

Animals↗
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

Colonoscopic decompression for acute pseudoobstruction of the colon (Ogilvie's syndrome). Report of 22 cases and review of the literature.

This report has described a series of 22 patients who underwent colonoscopic decompression for acute pseudoobstruction of the colon and summarizes those cases previously reported in the literature. Twenty of the 22 patients (91 percent) were successfully treated by decompression initially. Fifteen patients (68 percent) were cured with the initial procedure, and 4 patients (18 percent) experienced recurrence. Overall, in 17 patients (77 percent), the pseudoobstruction resolved completely with colonoscopic decompression. Three patients (14 percent) underwent operation because of cecal dilatation refractory to colonoscopic decompression, and in one patient (4.5 percent), the colonic dilatation resolved spontaneously after a failed colonoscopy. Complications resulted in the death of one patient (4.5 percent). Our data are similar to those in the literature and indicate that colonoscopic decompression is a safe and efficacious first line of treatment for acute pseudoobstruction of the colon.

Acute Disease↗
PubMed1984

Longitudinal and radial variations of pressure in the human anal sphincter.

The pressure profile of the human anal canal integrates the effects of several separate muscles including internal and external and sphincters and the puborectalis. To define the topography of pressure along the anal canal, we developed a new probe that features four perfused side-hole channels spaced at 90 degrees circumferentially. In 18 healthy volunteers (10 women, 8 men), simultaneous four-quadrant pressures were measured at orad, mid-, and distal stations in the anal canal, at rest and during a maximum voluntary "squeeze." Anterior quadrant pressures were reduced significantly (p less than 0.001) at the orad station at rest and during maximum voluntary effort. In the midcanal, radial pressures were equal in all quadrants. Distally, pressures in the posterior quadrant were significantly lower than those in the other three quadrants. Men had longer sphincters than women, but men had higher pressures at the orad station only. Orad pressures were reduced in women who had had vaginal deliveries. We conclude that the human anal canal has marked, but consistent, radial and longitudinal variations of pressure. Based on these results, a structural and physiological explanation for their genesis is suggested. The findings may also be relevant to the development of cystoceles, rectoceles, and chronic anal fissures.

Adult↗
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 continent ileostomy device.

The feasibility of achieving fecal continence by mechanical occlusion of an end-ileostomy is explored. Accordingly, progressive stomal occlusion with an indwelling occluding device was evaluated in four healthy patients with Brooke ileostomies. Pre-occlusion clinical and physiologic tests were done, including fat balance, intestinal transit time, ileal motility and absorption, ileal compliance, ileal radiography, and ileoscopy. Progressive stomal occlusion was then employed until periods of occlusion of 5 to 8 hours were achieved after 10 to 16 weeks. Pre-occlusion tests were then repeated. Patients mastered use of the occluding device rapidly, and the device achieved reliable stomal continence in each patient. Whereas ileal capacity was small initially, intermittent occlusion resulted in a large, capacious ileal reservoir. Fasting ileal motility was increased slightly by stomal occlusion, although intestinal transit during feeding was not altered. Also, ileal absorption of glucose, electrolytes, vitamin B-12, and fat were not changed, and ileal mucosa at the site of occlusion remained intact endoscopically. The authors concluded that chronic intermittent occlusion of a Brooke ileostomy with an indwelling stomal device achieved enteric continence without impairing intestinal function.

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

Circulating prostacyclin metabolites in the dog.

The present study was designed to determine the concentration of prostacyclin (PGI2) metabolites in the blood of the dog. After a bolus i.v. dose of [11 beta-3H]PGI2 (5 micrograms/kg) into each of five dogs, blood samples were withdrawn at 0.33, 0.67, 1, 3, 5, 20, 30, 60 and 120 min postdrug administration. Plasma samples were extracted and the radioactive components were analyzed by two-dimensional thin-layer chromatography with autoradiofluorography and radio-high-performance liquid chromatography. The compounds were identified by comparing their mobility with synthetic standards; only parallel responses observed in both tests constituted positive identification. Seven metabolites were identified by these two techniques: 6-keto-prostaglandin (PG)F1 alpha; 6-keto-PGE1; 2,3-dinor-6-keto-PGF 1 alpha; 2,3-dinor-13,14-dihydro-6,15-diketo-20-carboxyl PGF 1 alpha; and 2,3,18,19-tetranor-13,14-dihydro-6,15-diketo-20-carboxyl PGF 1 alpha. Several additional compounds, both polar and nonpolar in nature, which did not co-chromatograph with any of our standards were also detected. Early samples consisted predominantly of 6-keto-PGF 1 alpha and other 20-carbon metabolites. By 30 min, the predominant metabolites were the 16- and 18-carbon dicarboxylic acids. By 60 min, 85% of the radioactivity was associated with two unidentified polar compounds. The evidence suggests that 6-keto-PGF 1 alpha probably reflects only the transient levels of freshly entering PGI2 in the circulation, whereas levels of the most polar metabolites (e.g., dihydro-diketo-carboxyl tetranor-PGF 2 alpha) may be a better measure of the overall PGI2 presence due to its longer half-life in circulation.

Animals↗
PubMed1983

Myoelectric activity and intraluminal pressure of the canine ileocolonic sphincter.

We constructed ileocolonic loops of distal ileum, ileocolonic sphincter, and proximal colon in 5 dogs; neuromuscular continuity was maintained between loop and intact bowel by a bridge of tunica muscularis. To study ileocolonic sphincter function, we recorded myoelectric activity from subserosal electrodes and intraluminal pressures from perfused catheters and a sleeve sensor. Recordings included at least one interdigestive myoelectric complex and four postprandial hours. Ileal slow waves were recorded from the loop and the ileocolonic sphincter; most interdigestive myoelectric complexes were propagated to the ileocolonic sphincter. Intraluminal pressures at the ileocolonic sphincter fluctuated phasically (mean 12.5 cycles/min) for 72% of recording time during fasting and 81% postprandially. Tonic pressures at the ileocolonic sphincter were higher during fasting (31 +/- 18 cmH2O; p less than 0.05) than postprandially (24 +/- 20 cmH2O); moreover, tonic pressures fluctuated more during fasting than after food. Tonic elevations of pressure were prolonged (mean duration 28.5 min) concomitant with arrival of phase 3 of interdigestive myoelectric complexes at the ileocolonic sphincter. Thus the ileocolonic sphincter participates in both the myoelectric and motor components of the interdigestive cycle and exhibits an intense phasic and tonic response to phase 3. The association of tonic pressure and intense phasic contractions may serve to retard and segment ileal chyme. On the other hand, the presence of rapidly propagated phasic pressures in the region may provide the basis for propulsive function. In this way, these unique motor events will facilitate two distinct functions of the region, namely the alternate retarding and forward propulsion of chyme.

Animals↗
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↗
PubMed1981

Metabolism of prostacyclin in Cynomolgus monkey.

The metabolism of prostacyclin (PGI2) in vivo was investigated in Cynomolgus monkey. Following intravenous infusion of 11-[3H]-PGI2 for three days, pooled urine was extracted with Amberlite XAD-2, then chromatographed and purified by Sephadex LH-20, and reverse phase column chromatography. Radioactive fractions were converted to appropriate derivatives for identification by gas chromatography mass spectrometry. Twelve metabolites were characterized, the major of which was 6-keto-PGF1 alpha, accounting for 13% of the urinary radioactivity. The metabolic pathways are similar to those observed earlier in the rat. The excretion of substantial amounts of unchanged 6-keto-PGF1 alpha indicated that the monkey was not able to metabolize PGI2 as avidly as the rat.

6-Ketoprostaglandin F1 alpha↗
PubMed1981

Seasonality of bipolar disorders in a forensic setting.

The authors studied 180 men who were found not guilty by reason of insanity (NGBRI) and committed to a forensic hospital for treatment. The 57 men diagnosed as bipolar disorder committed the crime for which they were found NGBRI (and which was, therefore, the result of mental illness) significantly more frequently during the 6 months August through January. The crimes committed by those in the bipolar group who were 31 years or older showed even seasonality. The crimes committed by the 123 men found NGBRI but not diagnosed as bipolar showed no seasonality. During the past 5 years on the forensic unit, the seclusion time, which was due primarily to manic behavior, was significantly higher during the 4 months December through March. These observations establish a seasonality of mania that appears age-related.

Adolescent↗
PubMed1980

Preparation of two dinor-PGI2 metabolites from 6-keto-PGF1 alpha by Mycobacterium rhodochrous.

The transformation of 6-keto-PGF1 alpha to two prostacyctin metabolites, 2,3-dinor-6-keto-PGF1 alpha (I) and 2,3-dinor-6,15-diketo-13,14-dihydro-PGF1 alpha (II) by Mycobacterium rhodochrous UC-6176 is described. The finding that the bacterium oxidized 6-keto-PGF1 alpha to the 6,15-diketo metabolite II shows that it contains 15-hydroxy prostaglandin dehydrogenase and delta 13 reductase enzyme systems.

15-Oxoprostaglandin 13-Reductase↗
PubMed1980

Tissue distribution and biliary excretion of prostacyclin metabolites in the rat.

When tritium labeled prostacyclin (PGI2) or 6-keto PGF1 alpha were injected i.v. into rats, one-third of the dose appeared in the liver after 15 min. Significant levels of radioactivity (8--16%) were also found in the small intestine. These observations plus the prominant fecal excretion of PGI2 radioactivity suggest that PGI2 and/or its metabolites undergo biliary excretion and enterohepatic recirculation. We therefore investigated PGI2 excretion and metabolite composition of the bile in bile duct cannulated rats. After a single bolus i.v. injection of 11-[3H] PGI2 into these rats, an average of 37% of the administered radioactivity was excreted in the bile within 3 hr. A number of metabolites were detected in the bile. The major metabolites were isolated and identified as 2,3-dinor-6-keto-PGF1 alpha and 13,14-dihydro-2,3-dinor-6,15-diketo-PGF1 alpha-glucuronide which each accounted for approximately one-third of the radioactivity in the bile. Other metabolites include 6-keto PGF1 alpha, 13,14-dihydro-2,3-dinor-6,15-diketo-PGF1 alpha, 13,14-dihydro-2,3-dinor-6,15-diketo-20-carboxyl PGF1 alpha and 2,3,4,5,6-pentanor-PGF1 alpha-gamma-lactone. We conclude that the liver plays a pivotal role in the inactivation and disposition of prostacyclin. The predominate metabolic pathways occurring in the liver are probably beta-oxidation and glucuronic acid conjugation.

Animals↗
PubMed1980

Radiotracer assessment of gastric mucosal permeability after hypovolemic shock.

Acute lesions of the gastroduodenal mucosa may result from gastric mucosal ischemia with subsequent cellular dysfunction, capillary leakage and increased susceptibility to mucosal damage. A new technique for measuring the effect of hypovolemic shock and gastric mucosal permeability is presented. Piglets were injected intravenously with human serum albumin labelled with 100 micro Ci of iodine-131 (131I-HSA). Serial blood and gastric samples were obtained for gamma counting during the control, hypovolemic shock and resuscitative periods. Increased gastric acid secretion and clearance of labelled serum albumin occurred after resuscitation from hypovolemic shock. The authors believe that increased capillary permeability and defective gastric mucosal cell function due to ischemia contribute to these changes.

Animals↗
PubMed1979

Absorption and penetration of dinoprost (prostaglandin F2 alpha) and dinoprost methyl ester into perfused mesenteric circulation in rats.

The absorption of dinoprost (prostaglandin F2 alpha) and its methyl ester in rat jejunum was studied. A 22-cm segment of rat jejunum was cannulated at both ends and connected to an oscillating perfusion pump system. The mesenteric vasculature supplying this isolated segment also was cannulated and perfused with Kreb's bicarbonate buffer with dextran. Solutions of 3H-dinoprost or its methyl ester were introduced into the lumen and oscillated through the segment. The disappearance of radioactivity from the lumen and the appearance of radioactivity in the vascular perfusate were monitored. The metabolite patterns in the vascular perfusate were analyzed by TLC. A lag between the time the drug disappeared from the lumen and the time it appeared in the mesenteric circulation was detected. This lag was longer for the methyl ester than for the free acid, even though the ester disappears from the lumen faster than does the free acid. Upon removal of dinoprost from the gut lumen, a gradual decrease in the amount of drug appearing in the mesenteric circulation could be detected. However, with the ester, a slight increase could be observed for approximately 0.5 hr, followed by a decrease. Metabolism by the gut wall appears to be greater for the ester than for the acid. The results suggest that, although the ester disappears from the lumen more quickly than does the acid, it actually penetrates to the blood at a slower rate and undergoes greater metabolism.

Absorption↗