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Biomedical subjects

J R Monson

Publications and source records attributed to J R Monson.

At least 127 records · Page 7Linked to original sources
PubMed1989

Immunological perspectives on pancreatic cancer and jaundice.

The development of techniques that permit detailed evaluation of functional aspects of the immune system has prompted a reassessment of our understanding of many tumor systems. Conspicuous in this area is the examination of malignancies associated with ineffective therapeutic strategies and poor survival patterns. Pancreatic ductal cancer is a prime example of such a system. This disease is further complicated by the frequent association with obstructive jaundice--a condition known to influence host immune responses. This review will attempt to discuss the current knowledge concerning alterations of the cellular immune system in patients suffering from pancreatic cancer. It will also contain a review of increasing attempts to achieve earlier diagnosis through the development of more efficient tumor markers. Finally, a brief resume will be presented of the relationship between the immune system and the presence of jaundice.

Biomarkers, Tumor↗
PubMed1988

The effect of indobufen on the thrombogenic potential of a Dacron prosthesis in an artificial circulation.

We have evaluated the effect of indobufen on the potential thrombogenicity of a Dacron vascular prosthesis in an artificial circulation. In a randomised double blind crossover study, ten healthy volunteers received indobufen 200 mg or placebo twice daily for one week. The artificial circulation, incorporating a 15 cm length of 8 mm Dacron graft was perfused for 60 mins with volunteer blood containing autologous 111In labelled platelets. Graft thrombogenicity was assessed by changes in platelet function, isotope labelled platelet studies and scanning electron microscopy. Platelet count fell significantly during graft perfusion (P less than 0.05) and aggregation was significantly inhibited by treatment with indobufen pre perfusion compared with the placebo group (P less than 0.02). While deposition of labelled platelets was not statistically significant, consumption of these platelets was greater in the placebo group (P less than 0.01). Field counts of adherent platelets made from scanning electron micrographs of the indobufen treated group were significantly lower (P less than 0.01) compared with the placebo group. We conclude that indobufen can reduce the thrombogenic potential of Dacron vascular grafts and suggest that it may be an effective antiplatelet agent for use following Dacron bypass surgery.

Blood Vessel Prosthesis↗
PubMed1988

Total parenteral nutrition adversely influences tumour-directed cellular cytotoxic responses in patients with gastrointestinal cancer.

The effects of total parenteral nutrition (TPN), using a lipid-based regimen, on non-specific lymphocyte function and tumour-directed cellular cytotoxicity was studied in 30 patients suffering from gastrointestinal (GI) cancer. After 7 days of TPN, augmented lymphocyte blastogenesis and production of the helper T-lymphocyte lymphokine Interleukin-2 were observed. However, over the same time period, significant impairment of basal natural killer (NK), and IL-2 activated NK activity were observed. Furthermore, lymphokine-activated killer (LAK) cell responses towards the NK resistant cell line DAUDI and the colorectal tumour cell line COLO 320, were markedly depressed. These findings have important implications for the use of this TPN regimen in GI cancer patients who might be considered for either surgical adjuvant or primary treatment with immunotherapy protocols.

Aged↗
PubMed1987

Lymphokine activated killer (LAK) cells in patients with gastrointestinal cancer.

Lymphokine activated killer (LAK) cells are a recently described cellular immune phenomenon with exciting potential for the treatment of tumours arising from solid organs. A comparison of some aspects of LAK cell precursors and LAK cell function was undertaken in 44 control subjects and 44 preoperative patients suffering from gastrointestinal cancer (20 localised and 24 advanced). Lymphokine activated killer cell precursor (natural killer (NK) cell) activity was significantly diminished in patients with advanced tumours (p less than 0.02) as was fully mature LAK cell activity against an NK resistant target cell (p less than 0.012). T-lymphocyte responses were not significantly different between the three groups. The reduced LAK cell generation was associated with a significantly diminished proliferative response of LAK precursors to stimulation with high dose IL-2 in vitro (p less than 0.012). Impaired LAK cell generation may explain the failure of adoptive cellular immunotherapy with LAK cells in some patients with advanced gastrointestinal cancer and prompts the search for means of augmenting this activity in such patients.

Aged↗
PubMed1986

Decreased interleukin-2 production in patients with gastrointestinal cancer.

Mitogen-stimulated basal and maximal interleukin-2 production has been measured in 60 control subjects and 45 patients with gastrointestinal cancer (14 localized and 31 advanced). Peripheral blood T cell subsets in these subjects were also measured. In patients with advanced gastrointestinal cancer interleukin-2 production (mean +/- s.e.m. units/ml) is impaired when compared with that of control subjects (26.5 +/- 7 versus 61.1 +/- 9, P less than 0.0001) or patients with localized cancer (26.5 +/- 7 versus 59.4 +/- 13, P less than 0.02). This cannot be restored to normal by in vitro irradiation of the lymphocytes, suggesting that the impaired function is not due to IL-2 suppressor cells. Using monoclonal antibodies the percentages of T cell subsets were similar in all groups and we therefore conclude that the reduced production of IL-2 in these patients is due to deficient helper T cell function. These results provide a rational basis for the administration of exogenous IL-2 in the future management of patients with advanced gastrointestinal cancer.

Antibodies, Monoclonal↗
PubMed1986

Immunorestorative effect of lipid emulsions during total parenteral nutrition.

This prospective in vivo cross-over study investigated the effect of Intralipid on immune responses. Twenty-three patients were randomly allocated to receive one of two alternative total parenteral nutrition (TPN) regimens for the first 7 days and the other regimen for the second 7 days. Only one of the regimens included a fat emulsion to provide 50 per cent of the calorific requirement. Immunological studies were performed on days 0, 7 and 14. These included peripheral blood T cell subsets, antibody dependent cellular cytotoxicity and basal and maximal Interleukin 2 production. All immunological parameters were significantly augmented during total parenteral nutrition using the lipid based regimen. No such change was seen during intravenous feeding with carbohydrate based TPN. It is concluded that, far from being immunosuppressive, the incorporation of a fat emulsion into a TPN regimen has immunostimulatory properties.

Adult↗
PubMed1986

Influence of intraperitoneal drains on subhepatic collections following cholecystectomy: a prospective clinical trial.

In this prospective randomized study, the influence of an intraperitoneal drain on the incidence and clinical significance of subhepatic collections occurring in patients after acute or elective cholecystectomy was assessed by ultrasound examination. A total of 112 patients entered the study, of whom 54 received a drain. There was no significant difference between the drainage and the non-drainage groups with respect to mean age or sex distribution, the number of patients in whom the gallbladder bed was formally closed (27 versus 21) nor in the number of acute cholecystectomies performed in either group (12 versus 13). Ultrasound detected 10 (18 per cent) collections in the drainage group and only one (1.8 per cent) in the non-drainage group (P less than 0.01, chi 2 test). None of the collections required any further treatment and no morbidity occurred that was directly attributable to the presence of the retained fluid. These results suggest that rather than preventing fluid collections, suction drains may predispose to the development of subhepatic collections after cholecystectomy.

Bile↗
PubMed1986

Delorme's operation: the first choice in complete rectal prolapse?

The Delorme operation has been used to treat 27 consecutive patients with complete rectal prolapse. The mean age in this group was 74 years and the average length of the prolapse was 12 cms. There was no postoperative mortality or morbidity. The follow-up ranges from 11 months to 64 months (mean 35 months) and so far there have been two recurrences. One of these has been successfully treated by a second Delorme operation. The second patient has declined further surgery. This low recurrence rate combined with the minor nature of the procedure suggests that the Delorme operation should be considered in all patients presenting with complete rectal prolapse.

Adult↗
PubMed1985

Closure of the lower end of the esophagus following esophagectomy.

Carcinoma of the middle third of the esophagus remains a major technical challenge in surgery. A speedy and safe method for dealing with the lower esophageal stump is described. After mobilization, the lower esophagus is denuded of its muscular fibers; the remaining mucosal tube is ligated and invaginated into the cardia by a pursestring suture.

Cardia↗