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Biomedical subjects

N W Read

Publications and source records attributed to N W Read.

At least 253 records · Page 14Linked to original sources
PubMed1983

Differences in anorectal manometry between patients with haemorrhoids and patients with descending perineum syndrome: implications for management.

Anorectal manometry was carried out at rest, during balloon distension of the rectum and during rectal infusion of saline in 19 patients with haemorrhoids, 30 patients with descending perineum syndrome and 21 controls. Basal and squeeze pressures were significantly higher in patients with haemorrhoids than patients with the descending perineum syndrome. A lower rectal volume was required to inhibit internal sphincter tone in patients with descending perineum syndrome compared with control subjects or patients with haemorrhoids. During rectal infusion of saline basal and peak anal pressures in patients with the descending perineum syndrome were lower than in haemorrhoid patients. Peak rectal pressure was abnormally high in both groups. These differences in anorectal function suggest that despite a similar presentation, the two conditions have a different pathogenesis. Moreover, inappropriate anal sphincter stretch or mucosal excision in patients with descending perineum syndrome may lead to severe incontinence.

Anal Canal↗
PubMed1983

The cutaneo-anal reflex: a useful index of neuropathy?

Recent studies have suggested that the latency of the cutaneo-anal reflex is prolonged in idiopathic faecal incontinence, suggesting neuropathic damage to the external anal sphincter. Electrical responses were recorded from the external anal sphincter following stimulation of the ipsilateral and contralateral perianal skin in normal subjects and patients with idiopathic faecal incontinence. Ipsilateral stimulation gave rise to shorter latencies of the earliest responses to stimulation compared with contralateral stimulation (P less than 0.001). When care was taken to compare results obtained by stimulating the skin on corresponding sides of the sphincter, the latency of both the early and late components of the cutaneo-anal reflex in incontinent patients was not significantly different from that in control subjects. The durations of the motor unit potentials, obtained by conventional electromyography, were prolonged in incontinent patients, indicating that they have external sphincter neuropathy. The data support the suggestion that external sphincter neuropathy in idiopathic faecal incontinence is due to a stretch injury to the pudendal nerve, and indicate that measurement of the latency of the cutaneo-anal reflex may be an inadequate means of demonstrating nerve damage in patients with idiopathic faecal incontinence.

Action Potentials↗
PubMed1983

The role of partial denervation of the puborectalis in idiopathic faecal incontinence.

Recent studies have suggested that patients with idiopathic faecal incontinence have neuropathic damage to the external and sphincter and pelvic floor musculature, though no direct assessment of puborectalis function has been made in intact man. Obstetric trauma and chronic straining at stool are thought to be possible causes for damage to the puborectalis nerve supply. In this study the motor unit potential duration in the external sphincter and puborectalis was measured by conventional electromyography in incontinent patients and two groups of continent patients who strained at stool. Our results confirm that incontinent patients had significant neuropathic damage to the puborectalis and the external sphincter compared with controls. Patients with the descending perineum syndrome, who were continent, showed partial denervation of the external sphincter and puborectalis, though the degree of abnormality in puborectalis was less than that in incontinent patients. Finally, patients with constipation showed neurogenic abnormalities in the external anal sphincter but not in the puborectalis. The findings suggest that partial denervation of the external sphincter can occur independently of partial denervation of the puborectalis in patients who strain at stool but if severe changes are present in both muscles, the patient is likely to be incontinent.

Action Potentials↗
PubMed1983

Relationship between small bowel transit time and absorption of a solid meal. Influence of metoclopramide, magnesium sulfate, and lactulose.

The times taken for a radiolabeled solid meal to empty from the stomach and terminal ileum and the absorption of the components of that meal were measured in 14 patients with terminal ileostomies under control conditions and after administration of either lactulose (40 g) or metoclopramide (20 mg tds), or magnesium sulfate (0.1 g/kg body weight). Absorption of each of the components of the meal was determined by chemical analysis of the ileostomy effluent. The radioisotope proved an excellent marker for the delivery of fat, protein, and carbohydrate residues. All three agents significantly reduced the time taken for the meal to empty from the ileum. This was associated with significant reductions in the absorption of fat, carbohydrate, protein, water, and electrolytes in the case of lactulose and magnesium sulfate. Although metoclopramide reduced transit time to the same degree as the other agents, its effect on absorption of fat, fluid, and electrolytes was much less, and absorption of protein and carbohydrate was unaffected. We therefore conclude that, although agents that accelerate postprandial transit of a meal may diminish absorption of the component of that meal in the small bowel, the extent to which this occurs cannot be predicted by a knowledge of transit kinetics alone and depends on the means by which transit is altered. The action of lactulose on the small intestine causes fluid and fat losses, sufficient to result in diarrhea and steatorrhea in a normal subject.

Adult↗
PubMed1983

The effects of atropine and secoverine on gastric secretion and motility in the mouse isolated stomach.

The isolated perfused stomach of the mouse was used to study the effect of atropine and secoverine on bethanechol-induced gastric acid secretion and gastric motility. Both atropine and secoverine inhibited cholinergically induced gastric acid secretion and gastric motility. Inhibition of gastric acid secretion by atropine and secoverine occurred at a similar dose-range (10(-9) and 2 X 10(-9) M). Secoverine inhibited bethanechol-induced hypermotility at doses (10(-11) M and above) that were lower than those of atropine (2 X 10(-9) M and above) required to produce this effect. Secoverine, unlike atropine markedly inhibited gastric motility at lower doses than those which affected secretion.

Animals↗
PubMed1983

Oral domperidone: double blind comparison with placebo in irritable bowel syndrome.

Symptom scores, stool data, and the transit of a standard, solid meal were measured in 25 patients with irritable bowel syndrome during baseline conditions and after four weeks treatment with placebo and domperidone in the form of a double-blind cross-over trial. All patients had previously undergone a comprehensive series of diagnostic investigations and had failed to respond to dietary supplementation with coarse wheat bran (10-30 g daily). Compared with placebo treatment, domperidone had no significant effect on gastric emptying, small bowel or whole gut transit times, stool weight, frequency, or consistency. Most symptoms improved significantly with both placebo and domperidone treatments, compared with the baseline period, but there was no significant difference between placebo and domperidone for any of the symptoms. Abdominal distension, however, was reported on more days per week during domperidone treatment (p = 0.02). The findings in this study do not support the use of domperidone in the management of irritable bowel syndrome.

Administration, Oral↗
PubMed1983

Psychological stress and the passage of a standard meal through the stomach and small intestine in man.

Gastric emptying half-time and mouth to caecum transit time of a solid meal were measured in eight normal volunteers, once during a period of psychological stress and again during a period of relative calm. No consistent or significant effect on gastric emptying was observed, but mouth to caecum transit times were faster in all subjects and this difference was highly significant (p<0.01).

Adult↗
PubMed1983

Irritable bowel syndrome: relationship of disorders in the transit of a single solid meal to symptom patterns.

The time taken for a solid meal to pass through the stomach, small intestine, and colon was measured in 61 patients with irritable bowel syndrome, subdivided according to their presenting symptoms, and in 53 healthy volunteers. Small bowel transit times were significantly shorter in patients who complained predominantly of diarrhoea (3.3 +/- 0.3 vs 4.2 +/- 0.2 h; p = 0.01; n = 21) and significantly longer in patients who complained predominantly of constipation (5.4 +/- 0.3 vs 4.2 +/- 0.2 h; p less than 0.01; n = 23) or pain and distension (5.4 +/- 0.4 vs 4.2 +/- 0.2 h; p less than 0.01; n = 17) compared with controls. Whole gut transit times were shorter in patients who complained of diarrhoea (35 +/- 5 vs 53 +/- 4 h; p less than 0.01), and longer in patients with constipation (87 +/- 13 vs 53 +/- 4 h; p less than 0.05) compared with controls. No significant differences in gastric emptying rates were shown between any of the patient groups and normal controls. Thirty-four patients reported pain, particularly in the right iliac fossa, during the meal transit test, and in 25 of these (74%), the onset of the pain was associated with the arrival of residues of the test meal in the caecum. Our results indicate that irritable bowel syndrome should be considered a disease of the small intestine as well as the colon.

Adult↗
PubMed1983

The use of conventional electromyography to assess external sphincter neuropathy in man.

Conventional electromyography was used to measure motor unit potential duration in the external anal sphincter in normal subjects and patients with idiopathic faecal incontinence. The results revealed a direct correlation between age and mean motor unit potential duration in control subjects, but no differences between age-matched male and female subjects. Patients with faecal incontinence exhibited prolongation of mean motor unit potential duration compared with matched controls. This technique provided useful quantitative data on reinnervation within the anal sphincter, complementing the results of single fibre electromyography.

Action Potentials↗
PubMed1983

Speculations on the role of motility in the pathogenesis and treatment of diarrhoea.

Comparatively little attention has been given to the role of gastrointestinal motility in the pathogenesis and treatment of diarrhoea. Here the relationship between motor activity and absorption in the small intestine has been assessed, as has that between small intestinal secretion and motility, and between colonic salvage and motility. It is suggested that diarrhoea should be considered as a disturbance of intestinal flow, involving disturbances in both motility and transport. The role of antimotility agents (particularly opiate-like agents such as loperamide) is reviewed. The most successful antidiarrhoeal agents are those that combine a reversal of epithelial secretion with an action on motility.

Animals↗
PubMed1983

Effect of gastrointestinal intubation on the passage of a solid meal through the stomach and small intestine in humans.

The effect of a gastrointestinal tube on the passage of a radiolabeled solid meal through the stomach and small intestine was investigated in 22 healthy volunteers using the gamma camera and breath hydrogen analysis. Gastric emptying was significantly retarded in 12 subjects, who had an intestinal tube in situ compared with 10 control subjects, who were not intubated (t 1/2 = 1.5 +/- 0.1 vs. 1.2 +/- 0.1 h; p less than 0.02). On the other hand, colonic filling was significantly accelerated in the intubated subjects (onset: 1.2 +/- 0.2 vs. 2.9 +/- 0.4 h; p less than 0.001; t 1/2: 4.1 +/- 0.3 vs. 5.6 +/- 0.5 h; p less than 0.001). Values for small bowel residence were significantly reduced in the intubated subjects (5.3 +/- 0.5 vs. 6.5 +/- 0.6 food hours; p less than 0.001). Paired studies, carried out in an additional 11 normal subjects, confirmed that small bowel transit time was significantly shortened during intestinal intubation in the same individuals (2.0 +/- 0.3 vs. 3.6 +/- 0.4 h). These results suggest that intubating the gastrointestinal tract may profoundly affect its function.

Adult↗
PubMed1983

Use of anorectal manometry during rectal infusion of saline to investigate sphincter function in incontinent patients.

Anal and rectal pressures and external sphincter electromyogram were recorded continuously during rectal infusion of 1.5 L saline in 18 normal subjects and 37 patients who complained of diarrhea and fecal incontinence. All subjects exhibited a pattern of regular fluctuations in anorectal pressure and electromyogram. All except 1 of the normal subjects were able to retain 1500 ml saline without leakage, and their pressure record comprised simultaneous rectal contractions, internal sphincter relaxations, and external sphincter contractions. None of the incontinent patients were able to retain 1500 ml saline without leakages, and leakages always coincided with the peaks of rectal pressure. Two manometric patterns were observed. Fifty-nine percent of incontinent patients exhibited a pattern of contractions of similar profile occurring throughout the anorectum. This finding was associated with low basal sphincter pressures, an easily inhibited anal sphincter tone, an obtuse anorectal angle, and a funnel-shaped configuration to the anal canal. These results suggested that, in this group, the internal sphincter was weak and easily inhibited so that the whole anorectum behaved as one fluid-filled compartment recording contractions of the external sphincter. The remaining 41% of incontinent patients exhibited a normal pattern of anorectal pressure fluctuations and had normal maximum basal pressures, although maximum squeeze pressures, rectoanal inhibitory reflex, and anorectal angles were abnormal. Peak rectal pressures were abnormally high in this group during saline infusion, suggesting that abnormally strong rectal contractions may play a role in the incontinence in this group.

Adult↗
PubMed1983

Differences in anal sphincter function and clinical presentation in patients with pelvic floor descent.

Perineal descent is found in patients with idiopathic fecal incontinence and patients with the descending perineum syndrome, who have little or no incontinence but present with a symptom pattern that suggests obstructed defecation. To investigate why patients with perineal descent present in different ways, manometric, radiologic, and neurophysiologic studies were performed in 53 patients with radiologically proven perineal descent and 34 control subjects. Thirty-two patients exhibited incontinence to rectally infused saline, while 21 patients presented with obstructed defecation but exhibited no incontinence. Both patient groups exhibited similar degrees of perineal descent on straining and increases in the motor unit potential duration of the external anal sphincter, indicative of neuropathic damage. Both groups had an abnormal rectoanal inhibitory reflex and an abnormal anorectal angle, though the latter was more obtuse in idiopathic fecal incontinence. However, although patients with incontinence had lower maximum basal and maximum squeeze sphincter pressures than normal, these values were normal in patients with obstructed defecation. Our findings suggest that perineal descent and neuropathy are not necessarily associated with incontinence as long as sphincter pressures remain normal.

Action Potentials↗
PubMed1982

A prospective study of the effect of haemorrhoidectomy on sphincter function and faecal continence.

The effect of haemorrhoidectomy on anal sphincter manometry and continence to faeces and rectally infused saline was investigated in 24 unselected patients with third-degree haemorrhoids. Haemorrhoidectomy resulted in the abolition of ultra-slow waves and significant decreases in basal and squeeze pressures, though these were reduced to normal values from abnormally high levels. Pressures remained at normal levels up to a year after surgery. An association was found between mucous soiling following surgery and an abnormally low postoperative squeeze pressure. There was no alteration in the function of the recto-anal inhibitory reflex following surgery. Only two patients developed incontinence to rectally infused saline for the first time following surgery. The addition of four-finger dilatation of the anal canal to the operative procedure did not cause any significant differences in sphincter manometry.

Adult↗
PubMed1982

A report of five patients with large-volume secretory diarrhea but no evidence of endocrine tumor or laxative abuse.

The purpose of this paper is to report five patients with chronic secretory diarrhea (maximum stool volume greater than 1 liter per day, duration 6 weeks to 8 years) in whom we could find no evidence of an endocrine tumor or of surreptitious laxative ingestion. All except one had severe hypokalemia. There was apparent improvement after treatment with prednisone in two patients and loperamide in one. The diarrhea resolved spontaneously in three patients and has undergone several temporary remissions in one patient. The last patient died after a severe unremitting illness. Extensive investigations failed to establish the etiology, but intestinal perfusion (carried out in four of the five patients) revealed secretion or abnormally low absorption of water and electrolytes in the jejunum and abnormally low absorption in the colon. The management of patients with chronic watery diarrhea is discussed.

Adult↗
PubMed1982

Effects of loperamide on anal sphincter function in patients complaining of chronic diarrhea with fecal incontinence and urgency.

We have investigated the effect of loperamide (4 mg tds) on the continence to a standard volume of rectally infused saline and anorectal manometry in 26 patients complaining of chronic diarrhea complicated by fecal incontinence and severe urgency. Each patient was treated for one week with loperamide (4 mg tds) and for one week with an identical placebo in a double-blind cross-over trial. Our results showed that as well as its established effects of improving stool consistency and reducing stool weight, frequency and episodes of incontinence and severe urgency, loperamide also significantly improved continence to a standard volume of rectally infused saline. This action was associated with an increase in the maximum basal sphincter pressure, an increase in the rectal volume required to abolish recovery of the rectoanal inhibitory reflex, and a reduction in rectal compliance. These results suggest that loperamide may have a specific action on the anal sphincter, which may aid continence in patients who complain of diarrhea and fecal incontinence.

Adult↗
PubMed1982

Ano-rectal activity in man during rectal infusion of saline: a dynamic assessment of the anal continence mechanism.

1. Anal and rectal pressures and the external anal sphincter electromyogram were recorded in eighteen normal subjects at rest and during rectal infusion of 1500 ml. saline at a rate of 60 ml./min. 2. During saline infusion, the recordings described a pattern of regular relaxations of the internal sphincter associated with contractions of the rectum and the external anal sphincter. The frequency of ano-rectal pressure fluctuations increased as the infusion progressed. 3. The peaks in rectal pressure were always lower than the lowest anal pressure in all normal subjects tested. 4. External sphincter contractions only occurred in association with 60% of internal anal sphincter relaxations and did not prevent the maximum decrease in anal pressure. These observations suggest that phasic contraction of the external anal sphincter does not play a major role in maintaining continence.

Anal Canal↗