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Biomedical subjects

N C Bird

Publications and source records attributed to N C Bird.

23 records · Page 2Linked to original sources
PubMed1987

Applied potential tomography. A new noninvasive technique for measuring gastric emptying.

Applied potential tomography is a new, noninvasive technique that yields sequential images of the resistivity of gastric contents after subjects have ingested a liquid or semisolid meal. This study validates the technique as a means of measuring gastric emptying. Experiments in vitro showed an excellent correlation between measurements of resistivity and either the square of the radius of a glass rod or the volume of water in a spherical balloon when both were placed in an oval tank containing saline. Altering the lateral position of the rod in the tank did not alter the values obtained. Images of abdominal resistivity were also directly correlated with the volume of air in a gastric balloon. Profiles of gastric emptying of liquid meals obtained using applied potential tomography were very similar to those obtained using scintigraphy or dye dilution techniques, provided that acid secretion was inhibited by cimetidine. Profiles of emptying of a mashed potato meal using applied potential tomography were also very similar to those obtained by scintigraphy. Measurements of the emptying of a liquid meal from the stomach were reproducible if acid secretion was inhibited by cimetidine. Thus, applied potential tomography is an accurate and reproducible method of measuring gastric emptying of liquids and particulate food. It is inexpensive, well tolerated, easy to use, and ideally suited for multiple studies in patients, even those who are pregnant.

Colloids↗
PubMed1986

Antiprotease capacity in acute pancreatitis.

Serial measurements of circulating antiproteases were carried out on 42 consecutive patients admitted with acute pancreatitis. In the 7 days following admission the serum levels of alpha 1 antitrypsin (alpha 1 AT), alpha 1 antichymotrypsin (alpha 1 ACT) and the trypsin inhibitory capacity (TIC) increased by more than 300 per cent. The serum concentration of alpha 2 macroglobulin (alpha 2 M) alone showed a decline which was most profound in those patients with severe acute pancreatitis. Initial experience of fresh frozen plasma as a source of extrinsic antiproteases in severe acute pancreatitis is that it fails to prevent the decline in alpha 2 M or increase the already elevated TIC of the patients' serum.

Acute Disease↗
PubMed1984

Controlled trial of the Grassi (pH) intraoperative test for completion of proximal gastric vagotomy.

Forty-eight patients undergoing PGV for duodenal ulcer were randomized to Grassi test (24) or no test (24). Operations were performed by surgeons who were Fellows of the Royal College of Surgeons trained in the technique of PGV and every effort was made to complete the vagotomy if the test was positive. Patients were assessed by standard pentagastrin test preoperatively and postoperatively. The two groups were closely matched for age (Grassi 48, non-Grassi 43), sex (Grassi 20 males; non-Grassi, 21 males), preoperative BAO (6.4 +/- 1.2 S.E.M. millimols hydrogen ions per hour and 6.6 +/- 0.9 S.E.M. millimols hydrogen ions per hour) and preoperative PAO (45.5 +/- 2.1 S.E.M. millimols hydrogen ions per hour and 40.5 +/- 2.6 S.E.M. millimols hydrogen ions per hour). Postoperatively, the BAO was 1.2 +/- 0.4 S.E.M. millimols hydrogen ions per hour for the Grassi group and 0.8 +/- 0.2 S.E.M. millimol hydrogen ions per hour. The postoperative PAO (pg) for the Grassi group was 19.1 +/- 0.9 S.E.M. millimols hydrogen ions per hour and for the non-Grassi group, it was 19.5 +/- 1.9 S.E.M. millimols hydrogen ions per hour. The mean reduction in PAO (pg) were 57.0 +/- 4.3 per cent for the Grassi group and 51 +/- 4 per cent for the non-Grassi group, but two patients in the non-Grassi group had a reduction of less than 10 per cent, one of whom has had recurrent symptoms at three months. Eight Grassi and four non-Grassi patients had reductions of greater than 65 per cent. The mean operating was 110.0 +/- 6.8 minutes for the Grassi patients and 87.0 +/- 3.1 for the non-Grassi patients.

Adult↗