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Biomedical subjects

D L Wingate

Publications and source records attributed to D L Wingate.

At least 91 records · Page 5Linked to original sources
PubMed1983

Habitual rumination: a benign disorder.

Nine patients who habitually ruminated after meals underwent clinical tests and psychological questioning. Barium meal radiography showed no abnormalities. In one patient oesophageal manometry detected an abnormally large gastric pressure wave 20 minutes after food. Although four patients had family psychiatric histories and three histories of overdose, anorexia nervosa, and mild reactive depression, none had any present serious psychiatric disorder. Behavioural therapy to reduce rumination was successful in one patient. Most patients responded to reassurance that the habit was harmless. Since the condition is a distinct clinical syndrome it may be recognised early with minimal investigations if doctors are aware of its existence.

Adolescent↗
PubMed1983

Complex clocks.

Periodic activity of the digestive tract is now a well-recognized phenomenon. Some years ago, it was proposed that this was controlled by a single "clock" at a distance from the gut, but subsequent study has shown that this explanation was inadequate. "Black box" analysis of available data suggests a new model which requires multiple clocks; this model is proposed as being consistent with current knowledge of the system.

Animals↗
PubMed1983

Receiving, decoding and noise limiting systems for a new pressure-sensitive ingestible radio telemetric capsule.

A new pressure-sensitive radiotelemetric capsule for recording intraluminal pressures within the human gastrointestinal tract has been developed; this capsule employs a pulsed mode of operation. Data recording as a pulse train greatly simplifies problems encountered hitherto in this field, but has produced the requirement for a decoding system which, on tape replay, will reproduce the original pressure change. A system is described here which, in addition to producing an analogue signal from the recorded pulse train, will also eliminate artefacts due to either spurious radio signals or variations in magnetic tape transport speed; it also provides a sensitive and accurate indication of transient signal loss.

Capsules↗
PubMed1983

The effects of motilin on periodic myoelectric spike activity in intact and transected canine small intestine.

The effects of motilin infusions on periodic myoelectric spike activity were studied in conscious dogs with an intact small intestine and in dogs with established jejunal Thiry-Vella loops (T-V loops). Myoelectric activity was recorded from chronically implanted electrodes on the intact intestine, the anastomosed intestine and on the jejunal T-V loop. During fasting, migrating myoelectric complexes (m.m.c.s) were present in the intact and anastomosed intestine and in the T-V loop; in the latter, intervals between m.m.c.s were significantly shorter (P less than 0.05). Infusion of motilin induced premature m.m.c.s in the intact and anastomosed intestine, reducing the interval between successive m.m.c.s (P less than 0.05). In contrast, in the T-V loop, motilin significantly reduced the number of m.m.c.s (P less than 0.01) and the interval between two m.m.c.s was prolonged. After an infusion of motilin, the number of m.m.c.s in the intact and anastomosed intestine was significantly reduced (P less than 0.01), with a corresponding increase in the intervals between m.m.c.s; no further changes were observed in the T-V loop. These results demonstrate that m.m.c.s are induced by motilin in the proximal gut, suggesting a humoral mechanism for m.m.c. initiation in this region. In contrast, the genesis of m.m.c.s in jejunal T-V loops is delayed by motilin.

Action Potentials↗
PubMed1983

Central representation and opioid modulation of gastric mechanoreceptor activity in the rat.

The effects of gastric distension on single-unit activity recorded from the dorsal vagal nucleus in the rat medulla have been studied using microelectrodes in anesthetized animals. Out of 97 units studied, 64 responded to gastric distension in one of four characteristic ways. It was possible to modify these gastric distension responses by iontophoretic application of Leu-enkephalin and naloxone. The predominant effect was diminution of the centrally recorded gastric distension response by Leu-enkephalin. These studies show it is possible to modulate the central representation of gastric mechanoreceptor activity by an opioid peptide that is common to both the gut and the brain. It is suggested these studies provide evidence that opiate effects on the gastrointestinal tract are mediated centrally as well as peripherally.

Action Potentials↗
PubMed1983

Cholecystokinin octapeptide and gastric mechanoreceptor activity in rat brain.

Extracellular unitary recordings were made from neurons in the rat dorsal vagal nucleus, and the response of these neurons to iontophoretically applied cholecystokinin octapeptide (CCK-OP) and proglumide (a novel CCK antagonist) was studied. The effect of CCK-OP and proglumide on the response of the neurons to gastric distension was also studied. Seventy-four percent (n = 39) of the neurons studied were excited by CCK-OP. It was not possible to antagonize the response to CCK-OP with proglumide. CCK-OP was also found to be an effective modulator of the response to gastric distension; the effects were diverse ("on" responses were augmented; "off" and "transient" responses were diminished) but were always the same within each characteristic pattern of response to distension. These results provide supporting evidence for CCK-OP, a peptide common to both brain and gut, acting in the role of a neural modulator in the control of the gastrointestinal tract. It is possible to speculate that the potent effect of CCK-OP on neuronal excitability and on the central representation of gastric mechanoreceptor activity may well substantiate the role of CCK-OP as a central regulator of feeding behavior.

Action Potentials↗
PubMed1983

Experience with the 'Triple Test' in pancreatic disease.

The results of the secretin-pancreozymin test, duodenal aspirate cytology and hypotonic duodenography (the Triple Test), performed during a single duodenal intubation in patients with pancreatic or ampullary carcinoma, chronic pancreatitis and non-pancreatic disease were analysed retrospectively. Thirty-five of 36 carcinoma patients and all 11 chronic pancreatitis patients had an abnormal result. One hundred and sixteen of 170 non-pancreatic disease patients had a normal result. It would appear that the Triple Test (TT) may be a useful screening test for pancreatic disease.

Cholecystokinin↗
PubMed1982

Sustained mental stress alters human jejunal motor activity.

The effect of prolonged mental stress on upper small bowel motility was studied in 11 healthy, medical students using a pressure-sensitive radio-pill. During eight hours of continuous observation, subjects were stressed for four hours with a modified dichotomous listening test. During the first two hours of stress, inhibition of fasting motor complexes occurred and this effect was marked in the seven subjects who showed an appreciable cardiovascular response to stress.

Adult↗
PubMed1982

Patterns of small intestinal motility in duodenal ulcer patients before and after vagotomy.

Prolonged (18-24 hours) recordings of the pattern of small intestinal motor activity have been made, using radiotelemetry, in seven patients before surgery for chronic duodenal ulcer, seven after truncal vagotomy, and four with persistent post-vagotomy diarrhoea. There was no difference in the pattern of fasting cyclical activity between the three groups but the duration of feeding activity after a standard meal was reduced in asymptomatic truncal vagotomy patients compared with duodenal ulcer controls (p less than 0 . 05). In patients with post-vagotomy diarrhoea, the duration of the feeding pattern was further reduced compared with the asymptomatic post-vagotomy patients (p less than 0 . 001). It is suggested that altered emptying of food from the stomach in these patients together with duodenal receptor insensitivity is the probable explanation of these changes.

Adult↗
PubMed1982

Gastric emptying as a determinant of the oral glucose tolerance test.

Intraindividual variation in the results of repeated oral glucose tolerance tests in normal subjects is well recognized but incompletely explained. The present studies show that such variation can be produced by ingestion of the glucose solution during different phases of the normal fasting activity cycle of the upper gut. Such variation is not seen when glucose is administered intraduodenally during the same phases of activity. Gastric emptying shows similar variation with the activity cycle; larger volumes of solution were emptied from the stomach during activity than quiescence, thus presenting greater quantities of glucose solution to the small intestine for absorption. Metoclopramide and hyoscine butylbromide, drugs known to influence the rate of gastric emptying, reduced the variation in the glucose tolerance test. The data suggest na possible use of the glucose tolerance test for the assessment of gastric emptying.

Activity Cycles↗
PubMed1981

Purgative abuse associated with reversible cachexia, hypogammaglobulinaemia, and finger clubbing.

Laxative abuse may cause systemic and metabolic changes, but cachexia has not been reported as a predominant feature. A patient with finger clubbing and extreme wasting recovered when senna intake was stopped and nutritional care provided. A diagnosis had been made of acquired common variable hypogammaglobulinaemia with absence of circulating B lymphocytes. The immunological abnormalities were corrected after senna intake was stopped and lean body mass restored.

Agammaglobulinemia↗
PubMed1981

Oral hyoscine butylbromide does not alter the pattern of small intestinal motor activity.

1. Continuous recording of proximal jejunal motility of conscious healthy subjects was made following ingestion of 200 mg hyoscine butylbromide (ten times the recommended therapeutic dosage). 2. There was no detectable modification of fasting or postprandial motor activity, although the therapeutic potency of the standard intravenous dose was confirmed.

Administration, Oral↗
PubMed1981

Effects of intestinal secretagogues and distension on small bowel myoelectric activity in fasted and fed conscious dogs.

1. Defined jejunal segments were perfused with solutions of bile salts and of ricinoleic acid during fasting and after feeding in two groups of conscious dogs, one with the segment in continuity, and the other with a Thirty-Vella loop. Myoelectric activity was recorded from chronically implanted electrodes on the jejunal segment and also from the proximal and distal in situ bowel.2. The results in both groups were identical. During fasting, migrating complexes were present in the segment, but were replaced by intermittent spike activity during chenodeoxycholate without and with ricinoleic acid perfusion. After food, when migrating complexes were replaced by intermittent spike activity, none of the solutions produced any consistent effect.3. In fasted animals, low levels of distension (15 mmHg) interrupted the migrating complexes in the segment and induced intermittent spike activity which was similar to that seen with the secretagogues. The migrating complexes in the main bowel continued during distension. In fed animals, spike activity increased in the segment during distension at 25 mmHg and decreased in the main bowel. In both groups, distension of the segment to pressures between 37.5 and 50 mmHg abolished spike activity both in the distended segment and the main bowel in fasted and fed states, and, in fasted dogs, migrating complexes were also abolished.4. These results demonstrate that the inhibitory intestino-intestinal reflex is mediated through extrinsic nerves and does not require an intact myenteric plexus, whereas the altered myoelectric activity induced by secretagogues is a local effect and does not spread to adjacent bowel through either intrinsic or extrinsic neural pathways. It seems likely that the local motor effect of secretagogues is a result of net secretion, producing distension to pressures below the threshold required to activate the intestino-intestinal reflex.

Action Potentials↗