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Biomedical subjects

H L Young

Publications and source records attributed to H L Young.

At least 37 records · Page 2Linked to original sources
PubMed1991

Oxygenation in the stomach and the effect of truncal vagotomy.

A Clark polarographic oxygen electrode allowed detailed mapping of tissue oxygen (PtO2) levels on the anterior surface of the stomach in five patients undergoing cholecystectomy. No significant difference in mean PtO2 was detectable between greater and lesser curvatures. A significant difference in mean PtO2 was detected between the body of the stomach and the pylorus (Mann-Whitney, P less than 0.01). The effect of truncal vagotomy on PtO2 was evaluated in six patients undergoing this procedure for duodenal ulceration. Mean postvagotomy stomach PtO2 levels (46 +/- 12 mmHg) were significantly lower (Wilcoxon test, P less than 0.001) than prevagotomy levels (59 +/- 14 mmHg). Truncal vagotomy did not have any significant effect on small intestinal PtO2. This work provides the first objective evidence of the relatively diminished tissue oxygenation in the gastric antrum and pyloric region, and confirms blood flow studies of the effects of vagotomy.

Adult↗
PubMed1990

Stress in surgeons.

A sample of 1000 members of the Association of Surgeons of Great Britain and Ireland was circulated with a postal questionnaire relating to their occupational stressors, their type A coronary-prone behaviour and their mental health. Six hundred and seventy-two (67 per cent) useable forms were returned anonymously. The major individual stressors were: (1) the interference of the job with personal life, (2) general administration, and (3) the number of patients in clinics. Type A behaviour was similar to that of other professional groups. Surgeons showed mean scores significantly higher than the general population on two subscales of the mental health index (free-floating anxiety and hysterical anxiety). The findings for the few female surgeons (2 per cent) were similar to those in men but they did not exhibit raised free-floating anxiety levels.

Adult↗
PubMed1990

Intraoperative tissue oximetry in the human gastrointestinal tract.

Tissue oxygen tension was measured using a modified Clark oxygen electrode in the gastrointestinal tract of 33 patients undergoing laparatomy. The electrode, which incorporated a thermistor, had a linear response to oxygen tension (r = 0.995, p less than 0.001). The patients were all maintained on an inspired oxygen concentration of 33 +/- 3% and had a mean arterial oxygen tension (PaO2) of 124.9 +/- 31.9 mm Hg. Tissue oxygen tension measurements (mm Hg, mean +/- SD) were recorded from the serosal surfaces of the stomach (46.3 +/- 15.4), mid-ileum (36 +/- 9.7), terminal ileum (33.5 +/- 11.5), cecum (30.3 +/- 7.4), transverse colon (38.5 +/- 10), descending colon (29.3 +/- 11), and sigmoid colon (39.2 +/- 7.7) and tended to increase with increasing PaO2 (r = 0.70, p less than 0.001). Arterial occlusion resulted in a gradual decrease in tissue oxygen tension. It is concluded that intraoperative tissue oxygen tension measurement is feasible, and that the technique may have clinical applications in the assessment of intestinal viability.

Adult↗
PubMed1989

A multicenter trial of the use of the proteolytic enzyme inhibitor aprotinin in colorectal surgery.

Animal studies have demonstrated the value of the proteolytic enzyme inhibitor, aprotinin, in reducing collagen breakdown and improving the healing of experimental colonic anastomoses. A double-blind, multicenter, prospective trial has evaluated the use of aprotinin in the prevention of anastomotic leakage in patients. Two hundred sixteen patients undergoing colonic resection and anastomosis were studied. Patients were randomized to receive either aprotinin or placebo intravenously, peroperatively, and for the first three postoperative days. Anastomotic integrity was assessed clinically and by Hypaque enema on the tenth postoperative day. Although the use of aprotinin was not associated with a significant overall decrease in anastomotic leakage rates, in 95 patients undergoing anterior resection, leakage rates in those receiving aprotinin (clinical 10.8 percent; radiologic 32.4 percent) were lower than in those receiving placebo (17.2 percent and 43.1 percent, respectively). An apparent adverse association was noted, however, in patients undergoing left hemicolectomy or sigmoid colectomy who received aprotinin.

Anastomosis, Surgical↗
PubMed1988

Local depot methylprednisolone injection for painful anal Crohn's disease.

Treatment, by local depot methylprednisolone injection, of severe anal pain in Crohn's disease not associated with overt sepsis is reported. It has given dramatic relief in 5 patients, but has not been successful in 2 patients where anal disease was in continuity with severe rectal involvement. Treatment has been effective for greater than 1 yr, and no complication of the technique has been found on regular follow-up. When compared with previous attempts at treatment, the beneficial results attained with methylprednisolone injection suggest that the effect is more than a placebo response. Careful patient selection to exclude overt sepsis or severe rectal disease is recommended before proceeding to steroid injection.

Adult↗
PubMed1987

Tissue oxygen tension as a predictor of colonic anastomotic healing.

Inadequate blood flow causing tissue hypoxia can result in failure of anastomotic healing. Tissue oxygen tension (ptO2) measurement has been used to predict anastomotic leakage in animals, but its use in humans has not been described previously. A Clark-type oxygen electrode was used to measure ptO2 on the colon of 50 patients undergoing colonic resection and anastomosis. Baseline ptO2 levels were lowest on the descending colon (31.8 +/- 7.4 mmHg, mean +/- SD) and tended to increase at all sites with increasing arterial paO2 (r greater than .76, P less than .001). Perianastomotic ptO2 levels were predictive of subsequent anastomotic leakage when they were less than either 20 mmHg; 50 percent of the preresection ptO2; 15 percent of the arterial paO2; or 40 percent of the ptO2 at a control site (ileum). It is concluded that perioperative ptO2 measurements are of value in the prediction of anastomotic leakage.

Adult↗
PubMed1987

Spleen size in patients with inflammatory bowel disease. Does it have any clinical significance?

The finding that splenic atrophy is associated with a high complication rate in colitis has led to a long-term, prospective study of spleen size in inflammatory bowel disease. The spleen has been measured in 116 patients undergoing laparotomy for inflammatory bowel disease--80 Crohn's disease and 36 ulcerative colitis--from 1975 to 1985. Small spleen size, of lesser degree than that of classic splenic atrophy, is associated with presurgery disease complications as well as infective problems after surgery. Spleen size was not related to site or extent of disease, or to recurrence, but the wide range of spleen size seen in inflammatory bowel disease, comparable to that seen in malignancy suggests that more sophisticated tests of splenic function might show a closer correlation with disease patterns.

Body Height↗
PubMed1987

Low-cost video equipment for surgical teaching.

Recent developments in video-camera technology have resulted in the camcorder, a portable light-weight camera with an integral videorecorder, which, with standard VHS tapes, has been used for surgical teaching purposes. It also provides a simple, relatively inexpensive method for recording of operative technique, particularly out of hours.

Education, Medical↗
PubMed1986

Colonic healing: a role for polymorphonuclear leucocytes and oxygen radical production.

Using a model of 'reperfusion injury' as a mechanism of oxygen radical (OR) production in vivo, we have demonstrated that superoxide (O2-) is the major source of damage. Inhibition of its production from polymorphonuclear leucocytes (PMNs) by aprotinin, a protease inhibitor, or by scavenging with superoxide dismutase (SOD), resulted in reduced oxidation of of tissue glutathione (P less than 0.002). Colonic healing after anastomosis was also improved by aprotinin as measured by histology (P less than 0.05), breaking energy (P less than 0.001), breaking strength (P = 0.02), and by hydroxyproline content (P = 0.01). Allopurinol, although inhibiting glutathione oxidation, had no effect on PMN leucocyte OR production and did not protect against histological damage. These data demonstrate that PMNs endogenous to the tissue or attracted there as a result of trauma are the source of OR production in 'reperfusion'. Their inhibition improves colonic healing.

Animals↗
PubMed1985

Mechanism of protection against "reperfusion injury" by aprotinin. Roles of polymorphonuclear leucocytes and oxygen radicals.

We have proposed that reperfusion injury results from the overproduction of reactive oxygen metabolites by PMN as a result of increased sensitivity to oxygen during the low oxygen phase. Aprotinin was demonstrated to inhibit this overproduction and also radical production evoked by chemotactic peptide, 50% inhibitions occurring in the range 5-20 microM. Over this range, no effect on cell viability was observed. This inhibitory effect may provide a scientific basis for the protective effect of aprotinin in reperfusion induced injury.

Aprotinin↗
PubMed1985

Colonic anastomotic healing and oxygen tension.

Using a Clark oxygen electrode and a 133Xe clearance technique, tissue oxygen tension (T02) and blood flow have been determined in the small and large bowel of a rabbit experimental model. The predictive value of perianastomotic T02 in colonic anastomoses was determined, healing being assessed by leakage rate, tensile strength and hydroxyproline content. The effect of suture technique on colonic perianastomotic T02 has also been studied. Colonic and small intestinal T02 correlated with blood flow (r = 0.93). Basal colonic blood flow and oxygen tension were significantly lower than in the small intestine (P less than 0.01). Interrupted and continuous suture techniques decreased colonic perianastomotic T02, although mean T02 in the continuous group was significantly lower than in the interrupted group (P less than 0.01). The leakage rate was 10 per cent (1/10) for anastomoses constructed with a perianastomotic T02 above 55 mmHg compared with 100 per cent (10/10) if less than 25 mmHg (P less than 0.001). Perianastomotic T02 correlated with breaking energy (P less than 0.001), breaking strength (P less than 0.01) and hydroxyproline content (P less than 0.05).

Animals↗
PubMed1985

Plasma lactic dehydrogenase activities in men during bed rest with exercise training.

Peak oxygen uptake (peak VO2) and basal total activity of lactic dehydrogenase (LDH-T) and its five isoenzymes were measured in seven men, 19-21 years old, before, during, and after three 2-week bed rest (BR) periods, each separated by 3-week recovery periods. For 1 h X d-1 during BR, they performed isometric (250 kcal X -1) leg exercise, or no exercise. LDH-T was reduced (p less than 0.05) with all three regimens by day 10 of BR, but the decrease occurred at different rates. The earliest significant (p less than 0.05) reduction in LDH-T with the no-exercise regimen was associated with the greatest decrease in peak VO2 of 12.3%; isotonic exercise was next with a peak VO2 decrease of 9.2%; finally, isometric exercise had the least decrease in peak VO2 at 4.8%. Irrespective of the exercise regimen during BR, the increases in isoenzyme activities occurred mainly in LDH-1 and LDH-2 (heart subunits). Isometric (aerobic) muscular strength training appears to maintain skeletal muscle integrity and, perhaps, oxygen uptake capacity better during bed rest than isotonic exercise training. Reduced hydrostatic pressure during bed rest, however, ultimately overrides effects of both moderate isometric and isotonic exercise training (metabolism) in the resulting decrease in LDH-T.

Adult↗
PubMed1984

Characterisation of the under-agarose method for quantifying migration of highly purified human monocytes.

Optimal conditions governing migration towards chemotactic agent (MTCA) and random migration of purified human monocytes under agarose have been determined. These include an incubation period of 20 h, use of blood group AB pooled human serum, 0.75% agarose type I, pH between 6.8 and 7.2 and performance in 35 mm Falcon plastic petri dishes. A discontinuous Percoll density gradient was used to give monocyte purity of 83 +/- 10% and viability 97-99%. The use of highly purified monocytes was found to be essential, as increasing lymphocyte: monocyte ratio caused inhibition of migration.

Blood Physiological Phenomena↗
PubMed1984

In situ vein bypasses to distal tibial and limited outflow tracts for limb salvage.

To better define the limits of tibial reconstruction with saphenous vein bypass, we have analyzed our experience with the in situ vein valve incision technique in 83 cases of bypasses to the ankle or foot and 13 cases of bypasses to discontinuous tibial vessels. Bypasses to the ankle and foot had a 36-month cumulative patency rate of 70.4%. No statistical difference was noted with the use of small-caliber veins. The length of the bypass did not prejudice the long-term patency rate. Discontinuous tibial vessels can be used satisfactorily as an outflow tract for limb salvage.

Adult↗
PubMed1983

Effect of intravenous aprotinin (Trasylol) on the healing of experimental colonic anastomoses in the rabbit.

A randomized controlled trial to assess the effect of intravenously administered Trasylol on the healing of experimental colonic anastomoses in the rabbit has been performed. Before undergoing a standard left colonic resection and anastomosis, the animals received intravenous Trasylol (80,000 KIU). Postoperatively 160,000 KIU were given in divided doses per day for 3 days. Control animals received saline placebo. The mean bursting pressure of the anastomoses in the Trasylol-treated group was 47.7 +/- 3.0 mm Hg compared with 37.5 +/- 3.3 mm Hg for the control group (p less than 0.05). The mean difference in collagen content of the anastomosis compared to the resected specimen was +1.25 +/- 0.50 micrograms/mg and -1.02 +/- 0.47 microgram/mg for Trasylol and placebo, respectively (p less than 0.005). In this model intravenous Trasylol produces a significant elevation of the bursting pressure and a significant improvement in the collagen content of the anastomosis. This may be the result of collagenase inhibition.

Animals↗
PubMed1983

Collagenase inhibition in the healing colon.

A randomized controlled trial was performed to assess the effect of intravenous aprotinin (Trasylol) on the healing of experimental colonic anastomoses in the rabbit following a standard left colonic resection anastomosis. Assessment of tensile strength was by means of both bursting pressure and breaking strength. Those animals subjected to bursting pressure assessment received intravenous aprotinin 80 000 KIU (kallikrein inhibitory units) at the time of anaesthesia, and postoperatively 160 000 KIU per day given in divided doses for three days. Control animals received saline placebo. A further group of animals received a lower loading and maintenance aprotinin dose (40 000 KIU and 60 000 KIU per day respectively) with control animals receiving saline. Breaking strength was employed as the means of assessment. The mean bursting pressures were 47.7 +/- 2.9 mmHg and 37.5 +/- 3.4 mmHg for aprotinin and controls respectively (P less than 0.05). The mean difference in collagen content of the anastomosis compared to the resected specimen was +1.25 +/- 0.50 microgram/mg and -1.02 +/- 0.47 microgram/mg for aprotinin and placebo groups (P less than 0.005). The mean breaking strength in the aprotinin group was 169.6 +/- 74.5 g and 110.0 +/- 65.9 g for the saline group (P less than 0.02). The mean difference in collagen content of the anastomosis compared to the resected specimen was +0.95 +/- 0.69 microgram/mg and -1.5 +/- 0.78 microgram/mg for the aprotinin and saline groups respectively (P less than 0.05). The significant elevation of both bursting pressure and breaking strength assessments, with a significant improvement in the collagen content of the anastomoses, may be the result of collagenase inhibition following the use of intravenous aprotinin in the experimental model.

Animals↗