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Biomedical subjects

P Robinson

Publications and source records attributed to P Robinson.

At least 217 records · Page 12Linked to original sources

Ultrasound and HIDA: scanning in evaluating bile leaks after cholecystectomy.

Ultrasound and 99Tcm-HIDA scanning were compared in the evaluation of postoperative biliary leakage after cholecystectomy. In thirty-five patients the abdomen was scanned and imaged on the first postoperative day. Isotope activity in the right upper quadrant and whole abdomen was determined to obtain an activity ratio. Ultrasonography was also performed. Accumulation of 99Tcm-HIDA in the gall bladder bed or over the surface of the liver was regarded as evidence of a bile leak. Eleven patients had abnormal 99Tcm-HIDA images (activity ratios of 0.20-0.77, mean 0.51) but only five patients had loculated fluid on ultrasound scanning. Twenty-four patients had normal 99Tcm-HIDA images (activity ratios of 0-0.17, mean 0.21), but fifteen of these had loculated fluid on ultrasound scanning. We conclude that bile leaks occur in 30% of patients following cholecystectomy and are best detected by 99Tcm scanning rather than ultrasonography.

Adult↗

Mission critical.

Explore the source record for details and available documents.

Computers↗

Some limitations of the radioisotope bone scan in patients with metastatic prostatic cancer. A subanalysis of EORTC trial 30853. The EORTC Urological Group.

This article reviews the serial bone scans of 149 of 327 patients entered into a randomized prospective trial comparing orchidectomy versus zoladex and flutamide in patients with metastatic prostatic cancer. Attention is drawn to the difficulty of evaluating the response rate and of the importance of tumor load in determining survival. The use of sequential bone scans once the diagnosis of metastatic disease has been confirmed is of questionable value as the scans are expensive and contribute little to the further management of the patient in the absence of symptoms requiring relief.

Antineoplastic Combined Chemotherapy Protocols↗

Inhibition of intravascular platelet aggregation by endothelium-derived relaxing factor: reversal by red blood cells.

Studies were performed to determine whether endothelium-derived relaxing factor (EDRF) can inhibit platelet aggregation within the vascular lumen, and if so, whether the inhibition persists in the presence of red blood cells (RBCs). Canine femoral arteries mounted in an organ bath were perfused with physiologic saline solution to which acetylsalicylic acid was added to block prostacyclin formation. During contraction with phenylephrine, addition of acetylcholine to the perfusing solution to evoke EDRF release relaxed the vessel wall. Washed human platelets labeled with 14C-5-hydroxytryptamine were added to the perfusing solution, and activated by thrombin infused via a branch vessel. The perfusate was collected downstream and centrifuged; the fraction of 14C-5-hydroxytryptamine appearing in the supernatant reflected the degree of platelet activation. Stimulation of EDRF release with acetylcholine inhibited 14C-5-hydroxytryptamine release. Hemoglobin (Hb) (10(-5) mol/L) blocked vascular relaxation and platelet-inhibition. RBCs at a hematocrit of 10% (treated with echothiophate to block erythrocyte cholinesterase) did not prevent relaxation but reversed the platelet inhibition. Lower hematocrits did not completely block the inhibition. Thus, erythrocyte Hb may modulate the inhibition of intraluminal platelet aggregation by EDRF.

Animals↗

Neuroradiological and neuropsychological assessment in anorexia nervosa.

Seventeen patients with anorexia nervosa were examined by computed tomography (CT) and psychometry and compared with ten normal control subjects. The patients were found to have enlarged external cerebrospinal fluid spaces compared to controls. No differences were found in ventricular size and X-ray absorption density measurements between patients and controls. The patients performed abnormally on the symbol digit test, the scores of which displayed a significant negative correlation with the CT scan changes.

Adolescent↗

Placebo-controlled trial of misoprostol in cystic fibrosis.

Seventeen children with cystic fibrosis were studied in a 6-week double-blind, placebo-controlled, crossover trial to determine the efficacy of misoprostol, 100 micrograms, four times a day, in improving fat absorption in patients already on pancreatic enzyme therapy. In those patients who had greater than 90% absorption on enzyme therapy alone, no further significant increase in absorption was achieved with misoprostol administration. Those patients who had absorption of less than 90% on standard enzyme therapy showed a significant improvement with misoprostol administration (p less than 0.01). One patient had a significant elevation in the eosinophil count during the period of misoprostol administration, but there were no significant changes in any other hematological or biochemical parameter. Misoprostol appears to be of benefit to those children with cystic fibrosis who have residual malabsorption on standard enzyme therapy.

Alprostadil↗

A complex component modulating immune-deficient cells in leprosy patients leading to loss of viability of Mycobacterium leprae--a possible vaccine.

Macrophages from peripheral blood of leprosy patients, both multi-bacillary and paucibacillary are unable to kill phagocytosed Mycobacterium leprae due to their inability to produce superoxide (O2-) and hydroxyl radicals (OH.). The macrophages from healthy individuals are able to kill M. leprae along with release of O2- and OH. radicals. The deficiency in the macrophages of both types of leprosy patients is removed by activation of these cells when exposed to a culture supernatant obtained after stimulation of peripheral blood mononuclear cells from the same patients with delipidified cell components of M. leprae which are most likely cell wall proteins. The activation of macrophages also leads to recognition of whole live M. leprae as an antigen by cells from lepromatous patients. This activation of the phagocytes by delipidified cell components is blocked by cyclosporin A, indicating the possible role of several steps involved in immune activation of cells. The observations thus indicate the significant ability of delipidified cell components to eliminate the deficiencies in the macrophages from leprosy patients and restore them to behave like the cells from healthy individuals. Considering all these, it is suggested that delipidified cell components could be potential modulators, and are probably capable of functioning as a vaccine for leprosy.

Adjuvants, Immunologic↗

Systemic factors are trophic in bypassed rat small intestine in the absence of luminal contents.

Mucosal histology, crypt cell proliferation and brush border enzymes were measured in rats with varying degrees of jejunoileal bypass, in order to compare the effect of systemic and luminal factors on adaptive growth and differentiation (brush border enzymes) in small intestinal epithelium. Eighty five percent jejunoileal bypass caused a functional short gut; in intestine remaining in continuity there were significant increases in segmental weight, villus area and crypt depth, compared with sham operated controls and 25% jejunoileal bypass rats. Despite villus cell hyperplasia in 85% bypass rats, mucosal sucrase and alkaline phosphatase fell in jejunum and remained low in ileum, while leucine amino peptidase rose in ileum. There was a significant fall in villus area (p less than 0.01) and crypt cell production (p less than 0.001) in self emptying loops of 25% bypass rats not exposed to luminal contents compared with control segments of sham operated rats. In contrast, self emptying loops of 85% bypass rats were not atrophied despite the much greater distance from luminal nutrients; the villus area (p less than 0.01) and crypt cell production (p less than 0.005) were higher than in 25% bypass rats, and at least as great as in sham operated rats. These results indicate that adaptive hyperplasia has a variable effect on expression of brush border enzymes which might reflect villus cell immaturity. The atrophic effect of diversion of luminal contents can be counteracted by systemic growth factors released as part of the adaptive response; thus systemic growth factors are not dependent on a permissive effect of luminal contents.

Adaptation, Physiological↗

Human alveolar type II cells: stimulation of DNA synthesis by insulin and endothelial cell growth supplement.

Proliferation of type II cells is important for the recovery of the alveolar epithelium after acute lung injury. However, the factors that regulate the proliferation of human type II cells are unknown. Human alveolar type II cells were isolated from resected lung by dissociation with porcine pancreatic elastase and crystalline trypsin and purified by density-gradient centrifugation and serial differential adherence. The purity of the type II cells in the final adherent preparation was 84.4 +/- 1.1% type II cells by alkaline phosphatase and 87.7 +/- 2.8% by cytokeratin (n = 7). The medium MCDB-151 with 0.4% fetal bovine serum (FBS) was used to demonstrate the stimulatory effect of individual growth factors. Under these conditions, thymidine incorporation was stimulated by insulin, epidermal growth factor, endothelial cell growth supplement (ECGS), and acidic and basic fibroblast growth factors. Cholera toxin did not stimulate thymidine incorporation. The most effective stimulation was by the combination of insulin and ECGS. The incorporation of bromodeoxyuridine was used to identify the proportion of cells that were active in DNA synthesis. Insulin and ECGS increased the percentage of cells that incorporated bromodeoxyuridine from 8.5 +/- 1.3% to 21.3 +/- 2.4% (n = 6). Mitotic figures were seen in smears prepared from cultures incubated with insulin and ECGS. This observation was confirmed by electron microscopy, which demonstrated type II cells in metaphase. Increasing the concentration of FBS or human serum in the culture medium to 10% decreased the stimulatory effect of insulin and ECGS.(ABSTRACT TRUNCATED AT 250 WORDS)

Bromodeoxyuridine↗

An antigenic complex that restores ability in leprosy patients to kill Mycobacterium leprae--the probable molecular events identified by in vitro experiments.

The delipidified cell components of Mycobacterium leprae (DCC) obtained as an insoluble material was presented as an antigen by the macrophages of lepromatous leprosy patients. This resulted in in vitro lymphocyte proliferation and production of lymphokines, like IL-2 and IFN-gamma. This DCC induced culture supernatant was capable of activating patient macrophages through changes induced in the membrane, as monitored by same specific markers, before and after exposure to the supernatant. The activated macrophages could recognise M. leprae as an antigen to initiate cell mediated immunity and also recognise the bacilli as a pathogen to produce superoxide leading to the killing of phagocytosed M. leprae. Based on these observations, it is indicated that DCC could be a potent immunomodulatory restoring in the phagocytes of leprosy patients to kill M. leprae like normal resistant individuals.

Antigen-Presenting Cells↗