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Biomedical subjects

J Dent

Publications and source records attributed to J Dent.

At least 307 records · Page 17Linked to original sources
PubMed1977

Anal pressure studies in spinal patients.

Maximal and sphincter pressure was measured in 22 patients with spinal cord lesions and in a group of 10 controls, using perfused sleeve manometry. The mean resting pressure of the spinal patients was 63+/-8 (SEM) mm Hg, and of the control group 116+/-14 (SEM) mm Hg, P less than 0-01. When the rectum was distended by a balloon inflated with 100 ml of air a fall in anal sphincter pressure to 33+/-6 (SEM) mm Hg in the spinal group and to 78+/-10 (SEM) mm Hg in the control group was observed.

Anal Canal↗
PubMed1977

Gastrin release in response to arginine infusion.

Intravenous infusion of arginine has been reported to be a powerful stimulus of endogenous gastrin release. This response has been re-examined in 12 normal human subjects. 6 of the subjects showed a 40% or greater rise in serum gastrin, and these responses were widely scattered in time. Changes in overall mean serum gastrin were small and showed a significant (p less than 0.05) rise over mean basal levels at only one point in time which was during arginine infusion. In this study arginine infusion resulted in a much smaller and less consistent serum gastrin response than previous reports.

Adult↗
PubMed1976

Relationship of oral contraception to development of trophoblastic tumour after evacuation of a hydatidiform mole.

The need for chemotherapy for trophoblastic tumour after evacuation of a hydatidiform mole was found to be significantly increased in patients taking oral contraceptives before normal human chorionic gonadotrophin (HCG) values were obtained. Oral contraception was also found to delay the fall in HDG excretion in patients not requiring treatment with cytotoxic drugs.

Chorionic Gonadotropin↗
PubMed1976

Relationship of serum gastrin response to lower oesophageal sphincter pressure.

The role of gastrin in controlling lower oesophageal sphincter pressure (LESP) has been examined by measurement of LESP and serum gastrin response to a test protein solution and a control solution in humans. Both solutions were associated with significant (P less than 0-005) rise in LESP, but serum gastrin rose significantly (P=0-05) only after the protein solution. The rise in serum gastrin after the protein solution preceded the rise in LESP by 30 minutes. These results suggest that the lower oesophageal sphincter response to feeding may be independent of protein and is unrelated to gastrin release.

Adult↗
PubMed1976

A new technique for continuous sphincter pressure measurement.

The use of a constantly perfused side hole sensor (CPSH) for continuous measurement of maximal lower esophageal sphincter pressure (LESP) is associated with important but variable undermeasurement as a result of side hole displacement. A 5 cm long pressure sensor has been developed which measures maximal LESP continuously in the face of movement of the sphincter within the sensor length. This sensor, the perfused sleeve, is described, and validated by comparison with CPSH in man, the dog, and a model esophageal sphincter. The sleeve detects maximal LESP accurately, regardless of sphincter length, over the pressure range encountered in the lower esophageal sphincter. Continuous recording of LESP with the sleeve is unaffected by displacement that causes serious undermeasurement with CPSH.

Animals↗
PubMedDate not supplied

Utility of transesophageal echocardiography in the diagnosis of aortic conduit endocarditis in patients who have undergone the Cabrol procedure.

The Cabrol procedure is being increasingly performed in patients with aortic pathologic conditions. Transesophageal echocardiography can help in the prompt diagnosis of endocarditis in these patients. In this report we present transesophageal echocardiographic features of two patients in whom endocarditis developed after they underwent the Cabrol procedure for ascending aortic aneurysm caused by Marfan's syndrome.

Adult↗
PubMedDate not supplied

Antral compensation after proximal gastric vagotomy.

Proximal gastric vagotomy (PGV) has little impact on the normal pattern of solid gastric emptying, despite denervation of the proximal two thirds of the stomach and loss of the proximal gastric pump. In four healthy volunteers and four patients with PGV, we investigated the possible compensatory mechanisms that may come into play after proximal denervation of the stomach. We measured antropyloroduodenal motility with a 10-lumen sleeve/side-hole catheter for 180 minutes after ingestion of a dual-isotope radiolabeled mixed liquid/solid meal. Patients with PGV exhibited faster liquid emptying, but the rate of solid emptying was similar to that in healthy volunteers. The frequency of propagated antropyloric pressure wave was similar between the two groups, but patients with PGV exhibited less isolated pressure waves in the proximal antrum. The amplitude and duration of pressure waves recorded in the distal antrum were significantly increased in the PGV patients as compared to healthy volunteers. Although the pattern of propagated antral contractions and solid gastric emptying remains unchanged after PGV, there is an increase in the amplitude and duration of distal antral contractions, which may compensate for loss of proximal gastric pumping mechanisms.

Adult↗
PubMedDate not supplied

Requirements for accurate manometric recording of pharyngeal and esophageal peristaltic pressure waves.

The frequency characteristics and wave form of peristaltic pressure complexes occurring in the pharynx and esophagus of normal subjects were studied. For each of five subjects, five peristaltic waves were selected for analysis from the proximal and distal pharynx as well as the proximal, middle, and distal esophagus. Thus, 25 peristaltic waves were analyzed from each of the five regions studied, giving a total of 125 in all. After digitization of the peristaltic waves, pressure values were entered into a computer algorithm that performed a Fourier transformation to determine frequency content and wave slope. The computer analysis revealed that a frequency response flat to 5 Hz was adequate to record 98% of esophageal peristaltic waves with 98% accuracy. In contrast, recording accuracy up to 48 Hz was needed for high-fidelity recording in the pharynx. Rates of pressure change were substantially greater for pharyngeal peristaltic pressure complexes compared with esophageal peristaltic complexes. The results suggest that appropriately designed infused-catheter systems can readily meet the requirements for accurate recording of peristaltic pressure waves in the esophagus but not in the pharynx. Consequently, different instrumentation, such as an intraluminal strain gauge probe, is needed for accurate manometric recording of pharyngeal peristalsis.

Adult↗
PubMedDate not supplied

Influence of posture on transient lower oesophageal sphincter relaxation and gastro-oesophageal reflux in the dog.

The hypothesis that suppression of transient lower oesophageal sphincter relaxation (TLOSR) in recumbent postures in the dog is dependent upon the sensing of a gastric pool of liquid in proximity to the lower oesophageal sphincter was examined. Constant gastric insufflation with air (80 ml/min) was used to evoke TLOSR in unsedated, fasting animals. Oesophageal motility was monitored with a perfused manometric sleeve catheter assembly. Gastrooesophageal flow was recognized manometrically and by oesophageal pH recording. TLOSR occurred significantly less frequently in three recumbent positions (right lateral, left lateral and supine) than when the dog stood on four legs, but was more likely to be associated with acid reflux when they occurred in recumbent positions. Aspiration of the gastric pool was found to have no effect on triggering of TLOSR although it reduced the frequency with which acid reflux was associated with TLOSR. It is concluded that the low rate of occurrence of TLOSR in recumbent positions is unlikely to be explained by the presence of a gastric pool of liquid in proximity to the lower oesophageal sphincter.

Animals↗
PubMedDate not supplied

Motor mechanisms associated with slowing of the gastric emptying of a solid meal by an intraduodenal lipid infusion.

The aim of this study was to define better the motor phenomena associated with the slowing of gastric emptying by a duodenal lipid infusion. Antral, pyloric and duodenal motility were recorded in 10 healthy subjects with a manometric assembly which incorporated multiple perfused side-holes and a sleeve sensor positioned astride the pylorus. The gastric emptying of a standard solid meal and the distribution of the ingesta between the proximal and distal stomach were monitored with a radionuclide technique. A triglyceride emulsion was infused into the duodenum for 45 min once 25% of the meal had emptied. The infusion caused significant slowing in the rate of gastric emptying (P less than 0.01). This slowing in gastric emptying was associated with the suppression of pressure waves in the distal antrum (P less than 0.01) and proximal duodenum (P less than 0.01), the induction of pressure waves isolated to a narrow pyloric segment (P less than 0.01), and a redistribution of ingesta from the distal to proximal stomach. These findings suggest that pressure waves isolated to the pylorus, changes in the intragastric distribution of ingested food, and changes in proximal duodenal motility may all act in concert with changes in antral motility to regulate the gastric emptying of solids.

Adult↗
PubMedDate not supplied

Barrett's oesophagus.

Explore the source record for details and available documents.

Adenocarcinoma↗
PubMedDate not supplied

Stimulation of pyloric contractions by intraduodenal triglyceride is persistent and sensitive to atropine.

Intraduodenal lipid infusion stimulates phasic and tonic pyloric contractions and suppresses antral contractions. This study determined: (i) whether this response is sustained over 90 min; and (ii) the role of muscarinic mediation of this response. Antropyloroduodenal motility was recorded in 17 healthy volunteers with a sleeve/sidehole manometric assembly. Subjects received either a 90 min intraduodenal infusion of saline or triglyceride (20% Intralipid) at a rate of 1 mL/min; 30 min after the start of this infusion, the eight subjects who received triglyceride were given intravenous atropine 15 micrograms/kg over 30 s, followed by a maintenance infusion of 4 micrograms/kg/h until the study was completed. Intraduodenal triglyceride infusion stimulated isolated pyloric pressure waves consistently, producing a median rate of 2.4 per min after 30 min of triglyceride infusion, compared with a median rate of 0 per min pre-infusion. In intravenous saline studies, there was a reduction (P < 0.05) in the median rate of isolated pyloric pressure waves to 1.3 per min at 90 min, when compared with pyloric pressure waves at 30 min. Atropine reduced isolated pyloric pressure waves to a median rate of 0 per min, significantly different from preatropine (P < 0.01) and from intravenous saline studies (P < 0.0001). These results indicate that the phasic pyloric response to intraduodenal lipid persists during 90 min stimulation, albeit with significant attenuation. In humans, muscarinic cholinergic blockade prevents the occurrence of triglyceride stimulated localized pyloric contractions.

Adult↗