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Biomedical subjects

T D Lewis

Publications and source records attributed to T D Lewis.

17 recordsLinked to original sources
PubMed1989

Orthotopic cardiac transplantation: evaluation with CT.

As cardiac transplantation has become widely available, computed tomography (CT) of the chest has played a useful role in the examination of patients after heart transplantation. To determine anatomic features related to the procedure, the authors evaluated 59 scans in 46 patients who had undergone orthotopic cardiac transplantation. Aortic anastomosis (seen in 98% of scans) and altered spacing between the great vessels (83%) proved to be the most common and most reliable findings. Other features including atrial anastomosis, high main pulmonary artery segment, remnant superior vena cava, and cardiac reorientation were also seen. Accurate interpretation of adenopathy, mediastinal abscess, and pericardial effusion will be enhanced in these patients through a better understanding of the cardiovascular-pericardial complex, which is afforded by CT.

Anastomosis, Surgical↗
PubMed1985

Needle embolus: a unique complication of intravenous drug abuse.

We report a unique complication of intravenous drug abuse, central embolization of a needle from a peripheral site. A heroin addict dislodged a needle into the soft tissues of the forearm during self injection. Immediate surgical attempts to visualize and remove the needle were unsuccessful. On a subsequent admission, chest radiograph showed the needle in the right mid-lung field. No attempt at removal was made.

Adult↗
PubMed1981

Disorganised electrical activity in a child with idiopathic intestinal pseudo-obstruction.

This report presents the findings of investigation of a child with idiopathic intestinal pseudo-obstruction (IIP). Functional abnormalities of the smooth muscle of the gastrointestinal tract were disclosed by electrical recordings from the gut obtained after laparotomy. In vitro analysis of tissue and ultrastructure were undertaken and a possible aetiology of the disorder in this patient based on these findings is presented.

Action Potentials↗
PubMed1981

Initiation of migrating myoelectric complexes in human subjects: role of duodenal acidification and plasma motilin.

The hypothesis that acid, emptied intermittently from the stomach during fasting, might initiate the duodenal phase of the migrating motor complex was tested in normal human subjects. In addition, the relationship between plasma motilin concentrations and the initiation of migrating motor complexes was examined. Migrating complexes occurred spontaneously in the absence of acid in the duodenal bulb and in the presence of duodenal bulb neutralization with sodium bicarbonate. Thus duodenal bulb acidification is not necessary for initiation of the duodenal phase of the migrating motor complexes. Furthermore, cyclical increases in plasma motilin concentrations were not closely correlated with the initiation of the gastric phase of maximal activity of the migrating motor complexes. However, motilin concentrations were decreased significantly following onset of the duodenal phase III. We conclude that neither duodenal acidification nor increases in motilin concentration are necessary to initiate migrating motor complexes in man.

Adult↗
PubMed1981

Changes in plasma motilin concentration in response to manipulation of intragastric and intraduoduenal contents in man.

Immunoreactive plasma motilin concentrations were studied following a variety of stimuli in 24 healthy fasting subjects. Plasma motilin was measured by a radioimmunoassay using antibody GP 71 (J. C. Brown) and natural porcine motilin as standard. Basal motilin levels ranged from undetectable to 365 pg/mL. Antral and intraduodenal infusion of 50 mL o.1 N HCl (pH 1.2) at 5 mL/min failed to alter significantly plasma motilin levels but duodenal acid infusions at 17 mL/min caused a significant increase (70.8 +/- 29.5 pg/mL, mean +/- SEM; n = 6), maximal at 40 min. Duodenal alkalinization with 50 mL 0.3 M Tris buffer (pH 8.0) infused at 5 mL/min produced no change in plasma motilin. A mixed meal did not affect plasma motilin levels. Ingestion of 60 g fat significantly increased plasma motilin (n = 13; maximal increase 150.3 +/- 43.3 pg/mL at 30 min) but duodenal infusions of fat failed to increase plasma motilin levels. These results suggest that motilin secretion induced by fat requires that the fat be present initially within the stomach for secretion to occur. We conclude that ingested fat is a potent stimulus of motilin release. As duodenal acidification (50 mL 0.1 N HCl over 10 min) induces duodenal activity resembling migrating motor complexes but does not release motilin, our data argue against the release of motilin following duodenal acidification as a trigger for the initiation of these complexes in man.

Adult↗
PubMed1981

Gastroduodenal motility in a case of dystrophia myotonica.

A 53-year-old man with dystrophia myotonica developed symptoms of a chronic intestinal motility disorder. Incoordinate small bowel contractions as well as dilated segments were observed on x-ray examination. Gastroduodenal manometry in the fasted state showed contractions of reduced amplitude. A migrating motor complex occurred in the basal state. Pentagastrin and edrophonium injections increased motility; a liquid meal was followed by a normal motor response. The maximum gastric contraction rate (after pentagastrin injection) was 3.8/min. The maximum duodenal contraction rate observed at each duodenal recording site varied between 11.0 and 18.5/min. The lowest rate at each recording site was 11.1, 11.5, 11.0, and 11.2/min, while the fastest rate was 17.6, 16.6, 18.5, and 17.6/min. These maximum rates occurred independently of the rates at adjacent sites and of the drug infusions. The gastroduodenal motor abnormality in this patient thus predominantly affects smooth muscle, with the intrinsic neurons able to release acetylcholine and the muscle capable of responding to it. The results may indicate that electrical control activity in the duodenum intermittently oscillates more rapidly than normal, and when this occurs, phase-locking is absent. We conclude that in dystrophia myotonica there may be a defect in the cell membrane, which can cause more frequent electrical oscillations of the cell; alternatively, there may be a defect in cell-to-cell coupling.

Duodenum↗
PubMed1978

Small-bowel malabsorption and gastrointestinal malignancy.

In addition to lymphoma, there is an increased incidence of gastrointestinal carcinoma in patients with malabsorption due to celiac disease. This is frequently manifested by a loss of response to gluten withdrawal. Four such cases are described: one patient had lymphoma and the other three had cancer of the esophagus, jejunum, and pancreas, respectively. The literature indicates that carcinoma of the esophagus and small bowel is particularly common in patients with celiac disease. These findings suggest that celiac disease should be considered a premalignant condition and that such patients should undergo a regular radiographic survey to detect early cancer.

Aged↗
PubMed1978

Idiopathic intestinal pseudoobstruction. Report of a case, with intraluminal studies of mechanical and electrical activity, and response to drugs.

Intraulminal recordings of motility were made from a patient with chronic idiopathic intestinal pseudoodstruction. Contractile activity was recorded from esophagus and duodenum with and without cholinergic stimulation. Electrical activity was recorded from duodenum with and without cholinergic stimulation. Contractile and electrical activities were recorded from the sigmoid colon at rest and after morphine. Gastric fundic relaxation was measured during balloon distention. This patient showed abnormalities of esophageal function similar to achalasia, while gastric fundic relation was impared, with a more rapid rise in pressure on distention than is seen in normal persons. Duodenal and colonic electric control and response activities were present on occasion. Duodenal contractions occurred in response to both bethanechol and edrophonium. Therefore, the efferent cholinergic system of the small bowel appears to be functional in this case of idiopathic intestinal pseudoobstruction. The nonardrenergic inhibitory control of esophagus and gastric fundus appears to be functioning abnormally.

Adult↗