Biomedical subjects

I Cook

Publications and source records attributed to I Cook.

14 recordsLinked to original sources

PubMed1995

Influence of gravity and body position on normal oropharyngeal swallowing.

The influence of gravity, if any, on pharyngeal bolus transport is unknown. The aim of the present study was to evaluate the effect of gravity and body position on the radiological and manometric events during the normal oropharyngeal swallow. In eight healthy male volunteers, we performed simultaneous videoradiography and manometry, using a manometry catheter incorporating a perfused sleeve measuring upper esophageal sphincter pressure and three solid-state transducers recording pharyngeal pressures. Swallows of 5 and 10 ml of barium were performed in three different body positions: upright, horizontal, and 30 degrees head down (inverted). Hypopharyngeal intrabolus pressure increased significantly in the horizontal and inverted positions compared with upright, P = 0.0001. This resulted in increased maximal sphincter diameters during bolus flow (P = 0.0001) and shorter duration of sphincter opening (P = 0.03). As a result, transsphincteric flow increased in the horizontal and inverted positions, P = 0.04. Total swallowing duration, oral and pharyngeal transit time, pharyngeal peristaltic amplitude and duration, the length of the bolus in the pharynx, and excursions of the hyoid and larynx were unaffected by body position. We conclude that intrabolus pressure is an important determinant of upper esophageal sphincter opening in the healthy oropharynx and that gravity does not influence pharyngeal bolus transport. The healthy upper esophageal sphincter has residual opening capacity that can be demonstrated by altering body posture.

Adult↗

PubMed1989

Rectal bleeding. Do other symptoms aid in diagnosis?

It has been shown previously that it is difficult for a general practitioner to predict anal vs. colorectal sources of bleeding in patients presenting with rectal bleeding. The aim of the present study was to determine whether there are any aspects of such a patient's history or clinical features that strongly indicate bleeding from a colorectal cancer or polyp. One hundred forty-five consecutive patients, aged 40 years and older, who had complained of rectal bleeding to a general practitioner, were referred to a specialist for full colonic investigation. Among 15 symptoms and clinical features examined, few had any statistically significant association with the source of bleeding. There was an elevated probability of colorectal cancer (21 percent) in patients who had seen blood mixed with feces. Most bowel symptoms and clinical features are not helpful in deciding whether to proceed with full colorectal assessment in patients aged 40 and older who have rectal bleeding of recent onset.

Adult↗

PubMed1987

Malaria and other 'tropical' hazards.

Explore the source record for details and available documents.

Humans↗

PubMed1986

How important is rectal bleeding in the diagnosis of bowel cancer and polyps?

Overt bleeding from the anus is a common symptom of colorectal cancer but most frequently arises from a benign anal source. The aim of this study was to determine how successfully general practitioners and gastroenterologists could differentiate anal from colorectal sources of bleeding before full colonic investigation. 145 consecutive patients aged 40 years and over who had presented to a GP with rectal bleeding of less than 6 months' duration were referred to a specialist for total colonic investigation. The source of bleeding was diagnosed as colorectal cancer in 15 patients (7 stage A, 3 stage B) and polyps in 11. Of 63 patients in whom GPs predicted an anal source of bleeding only, 11 were ultimately found to be bleeding from a colonic or rectal source. The gastroenterologists (after rigid sigmoidoscopy) predicted an anal source of bleeding in 97, in 5 of whom the source was ultimately found to be colorectal. All patients aged over 40 who present with recent rectal bleeding should be referred for full colonic investigation.

Adult↗

PubMed1984

Characterization of a pancreatic tumor containing vasoactive intestinal peptide, neurotensin, and pancreatic polypeptide.

The biochemical characteristics of a pancreatic tumor from a patient with watery diarrhea, hypokalemia, hypochlorhydria, and steatorrhea is described Plasma concentrations of vasoactive intestinal peptide (VIP) were elevated 6-fold, those of neurotensin (NT) were elevated 10-fold, and those of pancreatic polypeptide (PP) were elevated 200-fold above the normal range. The pancreatic tumor removed was found to contain high concentrations of these peptides in a similar ratio to plasma. The tumor content of NT was 6 times higher than any previously reported, but no specific symptoms could be ascribed to NT. After removal of the tumor, plasma levels of VIP, NT, and PP returned to normal, and the diarrhea disappeared. Gel chromatography of plasma and tumor extracts indicated that all of the immunoreactive PP co-eluted with standard human PP. When the tumor extract was subjected to gel chromatography and high pressure liquid chromatography, two forms of VIP were detected, the major one resembling porcine VIP and a smaller more hydrophobic form detected by C- but not N-terminally directed VIP antisera. This smaller form was not present in normal ileum. Immunoreactive NT in plasma was predominantly an N-terminal fragment. High pressure liquid chromatography of the tumor extract revealed that approximately 75% of the NT immunoreactivity consisted of N-terminal fragments. In contrast, normal ileum contained only authentic NT-(1-13). Since N-terminal fragments of NT are thought to be biologically inactive, the nature of the immunoreactive NT should be determined before attempting to assign specific clinical symptoms to NT-secreting tumors.

Adenoma, Islet Cell↗

PubMed1970