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Biomedical subjects

S F Phillips

Publications and source records attributed to S F Phillips.

At least 37 records · Page 2Linked to original sources
PubMed1998

Effects of an irritable bowel syndrome educational class on health-promoting behaviors and symptoms.

OBJECTIVE: The degree to which patient education in the areas of diet, exercise, and stress management can improve symptoms of irritable bowel syndrome (IBS) through healthier lifestyle behaviors is unknown. The aim of this study was to determine the effects of outpatient education on the short and long term outcomes, and the association between health-promoting behaviors and symptoms. METHODS: Pender's Health Promotion Model provided the theoretical framework. The study had a prospective longitudinal design. A consecutive sample of 52 adult outpatients with IBS attended a structured class that taught health-promoting modifications of lifestyle. Participants completed the Health-Promoting Lifestyle Profile (HPLP) and selected items from a Bowel Disease Questionnaire (BDQ) before the class and 1 month and 6 months later. Spearman rank correlations were used to assess the association between HPLP and symptom scores. Wilcoxon rank sum tests compared changes in scores versus their baseline values. RESULTS: Response rates at 1 and 6 months were 75% and 83%, respectively. Results revealed significant 1- and 6 month-improvements in pain and Manning symptoms (p < 0.01) and in some HPLP scores (exercise at 1 month, p < 0.05; stress management at 6 months, p < 0.01). Significant associations were found between some, but not all, HPLP and symptom scores over time. CONCLUSION: A structured IBS educational class for patients with IBS improved symptoms and some health-promoting behaviors. However, relationships among specific behaviors and specific symptoms did not consistently correspond with this improvement.

Adult↗
PubMed1998

Duodenal motility in fasting dogs: humoral and neural pathways mediating the colonic brake.

We have previously described a negative feedback loop that inhibits duodenal motility when nutrients are infused into the ileum and colon. In the present study, we examined the role of extrinsic innervation and plasma levels of peptide YY (PYY) in mediating this phenomenon. We perfused neurally intact (n = 5 dogs) or extrinsically denervated (n = 6 dogs) isolated loops of proximal colon with isomolar NaCl or a mixed-nutrient solution at 2 and 6 ml/min for 4 h during fasting or for 2 h beginning 15 min after a meal. Both rates of infusion with NaCl prolonged the cycle length of the duodenal migrating motor complex (MMC) in the group with neurally intact loops but not in the group with extrinsically denervated loops. Nutrient infusions increased the MMC cycle length in both groups. Integrated plasma concentrations of PYY were increased by nutrients but not by NaCl in both groups. These data suggest that increased volumes and unabsorbed nutrients in the proximal colon alter proximal small bowel motility. Volume-induced effects are mediated via extrinsic nerves, whereas nutrient-induced effects may be mediated by humoral factors, such as plasma PYY.

Animals↗
PubMed1998

Rectal tone, distensibility, and perception: reproducibility and response to different distensions.

Increasing interest is focusing on the role of intestinal tone, distensibility, and mechanosensation in the genesis of abdominal symptoms. Experimental approaches usually feature balloon distension of the bowel with measurements of perception, tone, and compliance and/or elastance; however, the methodologies are standardized incompletely. We examined the reproducibility of repeated assessments of sensory perception, basal tone, and compliance and/or elastance of the rectum during distension. We also evaluated the response to inflations that varied in regard to control of pressure or volume, pattern of distension, and rate of inflation. Five healthy volunteers were studied under two separate protocols. The first featured a series of experiments on each of 5 days; the other consisted of 2 separate days of study. Repeated distensions evoked reproducible responses of sensation and compliance and/or elastance on a single day, providing a conditioning distension preceded them. Day-to-day variability was also sufficiently small to allow valid comparisons to be made on different days in healthy persons. The configuration of the distension profile (phasic, staircase, or ramp) and the rate of inflation (from 1 to 40 ml/s) had little effect on distensibility or perception. Perceptions were sometimes transient and sometimes constant, but no relationship was found between these temporal features and the magnitude of the stimulus. These observations help provide a basis as to how the responses to rectal distension can be best studied.

Adult↗
PubMed1998

Scintigraphic measurement of regional gastrointestinal transit in the dog.

Scintigraphic techniques can measure sequentially gastric emptying, small bowel transit, and colonic transit in humans, and comparable methods for experimental studies in animals would be useful. We developed such a method in dogs and examined the effects of prokinetic drugs on regional transit. Two isotopes were given to fasting dogs. Polystyrene pellets labeled with 99mTc were mixed in a can of dog food and 111In- labeled pellets were given in a gelatin capsule coated with a pH-sensitive polymer, designed to dissolve in the distal bowel. Gamma camera images were obtained for up to 24 h. Prokinetic drugs were given by intravenous injection. Duplicate baseline studies showed good agreement in seven dogs. In a second group (n = 4), intra- and interanimal variabilities were established. Two novel prokinetic drugs (AU-116 and AU-130) accelerated small bowel and colonic transit. A simple noninvasive method for measuring whole gut transit in dogs was developed and validated. Two new prokinetics accelerated small bowel and colonic transit.

Administration, Oral↗
PubMed1997

Dexpanthenol enemas in ulcerative colitis: a pilot study.

OBJECTIVE: To test the hypothesis that topical administration of pantothenic acid, a precursor of coenzyme A, might result in increased tissue levels of coenzyme A, improvement of fatty acid oxidation, and amelioration of ulcerative colitis. MATERIAL AND METHODS: In an open-label pilot study, three patients with active left-sided ulcerative colitis received nightly enemas that contained 1,000 mg of dexpanthenol for 4 weeks. Before and after the study, patients submitted stool specimens for short-chain fatty acid analysis and urine collections for measurement of pantothenic acid and dicarboxylic acids; they also underwent flexible sigmoidoscopy for procurement of biopsy specimens for histologic examination and measurement of colonic coenzyme A activity. A clinical disease activity index and histologic disease activity index were used to assess response. RESULTS: Despite increases in urinary pantothenic acid, no significant changes were found in colonic tissue coenzyme A concentrations, fecal short-chain fatty acid concentrations, or urinary dicarboxylic acid concentrations. Moreover, no significant changes in clinical or histologic disease activity were noted. Although stool frequency and rectal bleeding remained unchanged, all patients noted increased abdominal cramping, and one patient had an increased extent of disease. CONCLUSION: Topically administered dexpanthenol seems to be absorbed, but at the dose used in this study, it did not influence concentrations of colonic coenzyme A activity, fecal short-chain fatty acids, or clinical response in patients with active left-sided ulcerative colitis.

Administration, Topical↗
PubMed1997

Increased eosinophil granule proteins in gut lavage fluid from patients with inflammatory bowel disease.

OBJECTIVE: To explore the potential role of eosinophils in the pathogenesis of inflammatory bowel disease (IBD). DESIGN: We measured the concentrations of eosinophil granule proteins-namely, major basic protein, eosinophil peroxidase, eosinophil cationic protein, and eosinophil-derived neurotoxin-in gut lavage fluid. MATERIAL AND METHODS: Ten healthy persons and 17 patients with IBD (9 with Crohn's disease and 8 with ulcerative colitis) underwent gut lavage. Each study subject submitted an early specimen when lavage effluent became liquid and a late specimen when the output became clear. The concentrations of the granule proteins were measured by immunoassay. RESULTS: The median concentrations of eosinophil-derived neurotoxin and eosinophil cationic protein were significantly higher in patients with IBD than in control subjects for both early and late lavage specimens. Excretion of eosinophil peroxidase was also significantly higher in patients with IBD than in the healthy control subjects, but only in the early specimens. No differences were noted in the concentrations of any of the proteins between patients with ulcerative colitis and those with Crohn's disease. CONCLUSION: Concentrations of eosinophil granule proteins were increased in whole gut lavage fluid from patients with IBD in comparison with healthy control subjects. These results encourage further studies of the role of eosinophils in the pathogenesis of IBD.

Adult↗
PubMed1997

Rapid gastric emptying in patients with functional diarrhea.

OBJECTIVE: To analyze our experience in patients with chronic diarrhea by using a noninvasive transit study that measures gastric emptying as well as small bowel and colonic transit. MATERIAL AND METHODS: Results from 94 consecutive transit tests, for which diarrhea was the main indication, were reviewed and correlated with the final classification of patients as having an organic or nonorganic disorder. RESULTS: Sixty patients were considered to have a nonorganic cause of diarrhea, of whom 15 had previously undergone cholecystectomy. The other 34 patients were considered to have diarrhea on the basis of an organic diagnosis. Gastric emptying was more often rapid in patients with a nonorganic cause (P < 0.05), but not if cholecystectomy had been performed previously. Small bowel transit was fast more often in patients with organic diarrhea than in those with no organic cause of the diarrhea (P < 0.05); colonic transits showed no significant differences among groups. CONCLUSION: The findings implicate a motor abnormality of the upper gut, rapid gastric emptying, as a pathophysiologic mechanism of functional bowel disorders with diarrhea. The results imply that additional prospective observations should be worth-while.

Adult↗
PubMed1997

Pharmacological modulation of rectal tone alters perception of distention in humans.

OBJECTIVE: Drugs can alter perception of balloon distention of the GI tract. It has been proposed that the mechanism by which this occurs is through effects on visceral afferent pathways. Our hypothesis was that modulation of rectal tone will also influence the perception of rectal balloon distention. METHODS: Fasting and postprandial rectal tone, compliance, and perception of rectal distention were measured in 25 healthy subjects, using a five-armed, parallel, single-blinded study design. Each subject received either glucagon, nitroglycerin, clonidine, yohimbine, or saline. RESULTS: Rectal tone, but not compliance, influenced perception as measured by balloon distention of the rectum (r = 0.6, p = 0.002). Glucagon, nitroglycerin, and clonidine reduced and yohimbine increased fasting tone compared with saline. Compliance and postprandial tone were similar in all groups. Yohimbine increased rectal perception of distention. CONCLUSIONS: Tone is one of the factors that influences the sensory perception of balloon distention in the human rectum. Alpha2-adrenergic agents, a nitric oxide donor, and glucagon altered fasting rectal tone, but postprandial tone was similar after administration of each agent.

Adult↗
PubMed1996

Changing referral patterns for surgical treatment of ulcerative colitis.

OBJECTIVE: To determine whether referral patterns for surgical treatment among patients with chronic ulcerative colitis have changed in recent years, especially in view of the introduction of a new operation, the ileal pouch-anal anastomosis (IPAA). MATERIAL AND METHODS: Between January 1976 and December 1986, 981 patients underwent proctocolectomy at Mayo Clinic Rochester. Brooke ileostomy (N = 300), colectomy with ileorectal anastomosis (N = 33), proctocolectomy with Kock pouch (N = 180), or ileal pouch-anal anastomosis (IPAA) (N = 468) was performed. The indications for surgical intervention were categorized as emergent or elective, the latter including intractability, cancer, and cancer prophylaxis. For analysis, the duration from diagnosis of disease to operation, indications for surgical treatment, and types of operation were subdivided into pre-IPAA era (before 1981) and post-IPAA era (from 1981 onward) for the entire group and for distant versus local patients. RESULTS: More continence-preserving operations were done in 1981 and thereafter (76%) than before 1981 (46%). In the later segment of the study period in comparison with before 1981, fewer operations were done for emergent reasons (4% versus 8%) and a greater percentage of operations were done for elective indications, especially intractability (74% versus 61%). With the advent of IPAA in 1981, patients underwent operation sooner after the diagnosis was made (7.4 years versus 8.6 years before 1981). A smaller proportion of patients underwent operation for cancer prophylaxis during 1981 through 1986 (19%), however, than before 1981 (28%). CONCLUSION: Referral patterns for surgical treatment of patients with ulcerative colitis have changed in recent years--patients are being referred for operation sooner, before complications develop that necessitate emergent procedures. Although the changed referral pattern may be due to the availability of IPAA, other factors may also have a role.

Adult↗
PubMed1996

Colonic motility in health and disease.

Being the final pathway for chyme and digestive residues, the colorectum influences bowel function critically. The most important and relevant symptoms of colonic dysfunction are diarrhea, constipation, urgency, and pain. Despite the effects of many investigators, over several decades, the motor physiology of the human colon is still relatively obscure. Most is known about patterns of colonic transit. In practice, measurements of transit are the best characterized and most widely available tests of colonic motor function. Colonic hypersensitivity, implying an abnormality of afferent signaling, is assuming greater importance in the pathophysiology of conditions as common as IBS and inflammatory bowel disease.

Colon↗
PubMed1996

Methods for studying intestinal sensitivity and compliance: in vitro studies of balloons and a barostat.

The aim of this study was to compare in vitro various methods for recording intestinal sensitivity and compliance. Relationships between volume and pressure were determined in segments of penrose tubing and pig gut ("artificial intestine') using pressure increments of 2 mmHg (0-24 mmHg). We tested two direct methods of distension of the entire segments (by syringe inflation and the Mayo barostat); we also used three different balloon devices for indirect distension (a 10 cm polyethylene barostat bag, a 10 cm latex condom balloon and a 6 cm latex condom balloon). Maximal distending diameters of the recording systems were measured by injecting from 0 to 160 mL of air. The elastic properties of the balloons were also tested by distensions in air and in rigid tubes. All recording systems accurately detected a lesser compliance of the penrose drain as compared to pig gut. In absolute terms, only the compliance measured with a polyethylene barostat bag distended with a syringe was not different from the compliance of the segment as measured directly. The bellows of our barostat and the latex balloons had significant intrinsic compliances which interfered with the recorded pressure-volume curves. On the other hand, highly compliant plastic bags recorded most faithfully the compliance of artificial gut and that of non-compliant rigid tubes. For comparable volumes of distension, external diameters were larger with the 6 cm latex balloon than with the 10 cm latex balloon or the 10 cm polyethylene barostat balloon. A polyethylene bag distended with a non-compliant air injector (syringe) reflected most accurately the pressure-volume relationships of tubular structures. The different maximal diameters assumed by the three distending devices may explain, in part, why lower volumes of distension are required to elicit symptoms with smaller distending balloons in vivo.

Animals↗
PubMed1996

How well does stool form reflect colonic transit?

BACKGROUND: Watery stools are equated with rapid and hard stools with slow intestinal transit; however, the relation between stool form and transit through specific regions of the gut is not clear cut. In addition, more information is needed on interindividual variability of these measurements. AIM: To examine the relations between stool form and gastric emptying, small bowel and colonic transit. METHODS: Regional gut transit was assessed scintigraphically and segmental colonic transit was also quantified by radio-opaque markers. On two occasions, 32 healthy volunteers (12 men, 20 women) were studied, women during the follicular and luteal phases of menstruation, men twice within a similar four week period. Diets were standardised and stool form was recorded on a seven point scale. RESULTS: Women had significant harder stools; hard stools were correlated significantly with slow transit and loose stools with fast transit through the colon. CONCLUSIONS: Stool form could not be related to gastric emptying or small bowel transit.

Colon↗
PubMed1996

Variability of gastrointestinal transit in healthy women and men.

BACKGROUND AND AIMS: Measurements of gastrointestinal transit are made in clinical and research gastroenterology, yet their intrinsic variability is not well characterised. In particular, an influence of hormones on transit has been proposed as the basis for gastrointestinal symptoms that vary with the menstrual cycle. Our aims were to quantify individual differences in transit during the menstrual cycle in healthy women and to compare these with the intrinsic variability in healthy men. METHODS: On two occasions, whole gut transit was assessed scintigraphically and colonic transit quantified by radio-opaque markers. Thirty two healthy volunteers (12 women, 20 men) were studied, women during the follicular and luteal phases, men twice within a similar four week period. Diets and exercise were standardised prior to and during both studies. RESULTS: Colonic transit was significantly faster in men, and postlag gastric emptying was also more rapid; other indices of regional transit were not different between the sexes. Total colonic transit time was equally well reflected by the scintigraphic and radio-opaque marker methods. Important intraindividual differences were noted in both sexes. The variances in our samples predicted an 80% chance of detecting (with 95% confidence) a mean effect of menstrual hormones on transit that was in the same range as the intrinsic variation in men. CONCLUSIONS: Colonic transit was faster in men than in women. Although group means in the two studies were almost identical, single assessments of transit in subjects sometimes exhibited considerable variability, implying broad biological variations. Given this intrinsic variability, the influence of menstrual hormones on gastrointestinal transit must be small and of doubtful clinical significance.

Adult↗
PubMed1996

Constipation and fecal incontinence in the elderly population.

OBJECTIVE: To describe the assessment and management of constipation and fecal incontinence in elderly patients. DESIGN: We reviewed pertinent publications in the recent medical literature and outlined effective management strategies for constipation and fecal incontinence in the geriatric population. RESULTS: Constipation can be classified into two syndromes--functional constipation and rectosigmoid outlet delay. Evaluation consists of elicitation of a detailed history, directed physical examination, and selected laboratory tests. Management involves nonpharmacologic (such as exercise and fiber) and pharmacologic measures. Fecal incontinence in elderly patients can be due to stool impaction, medications, dementia, or neuromuscular dysfunction. Management options include modification of contributing disorders, pharmacologic therapy, and behavioral techniques. CONCLUSION: Constipation and fecal incontinence are common and often debilitating conditions in elderly patients. Management should be highly individualized and dependent on cause, coexisting morbidities, and cognitive status.

Aged↗