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Biomedical subjects

P McCulloch

Publications and source records attributed to P McCulloch.

At least 37 records · Page 2Linked to original sources
PubMed1997

Preliminary results of the use of intraperitoneal carbon-adsorbed mitomycin C in intra-abdominal malignancy.

Eleven patients suffering from intra-abdominal malignancy were treated with various doses of intraperitoneal mitomycin C adsorbed onto activated carbon particles. Seven of the patients underwent resection of their primary gastric tumour and all developed potentially life-threatening severe complications that proved to be fatal in four patients. The pattern of complications seen in these patients was unusual in patients undergoing gastrectomy and must be presumed to be secondary to the intraperitoneal mitomycin C. Intraperitoneal mitomycin C at a dose of 25 mg and 50 mg in the presence of an anastomosis or other suture line does not appear to be safe.

Adenocarcinoma↗
PubMed1997

Emergency admission of patients to general surgical beds: attitudes of general practitioners, surgical trainees, and consultants in Liverpool, UK.

OBJECTIVES: To determine (a) whether doctors involved in the process of emergency surgical admission could agree about which patients should be admitted, (b) whether there were consistent differences between doctors in different specialty groups, and (c) whether these opinions were greatly influenced by non-clinical factors. DESIGN: Independent assessment of summarised case histories by three "expert" clinicians (two consultant surgeons and one general practitioner (GP)), by a group of 10 GPs, and by a group of 10 junior and senior surgeons. Experts, but not other observers, scored admissions both independently and as a consensus group. Observers indicated for each patient whether they would admit, would not admit, or were unsure. SETTING: An urban general hospital with teaching status. SUBJECTS: Fifty consecutive patients admitted to the general surgical unit as emergencies during 1995. MAIN OUTCOME MEASURES: Proportion of admissions considered unnecessary or uncertain: agreement between observers on these proportions: effect of social and procedural factors on the admission decision. RESULTS: Between 8 and 34% of admissions were considered unnecessary and 20-38% of unclear necessity. Agreement between the groups of clinicians was not good. GPs and consultant surgeons showed the poorest agreement (kappa = 0.08 to 0.25, 4 comparisons), and the GPs scored a higher percentage of admissions as unnecessary (34 v 8-12%). After discussion, the consensus group achieved good to very good agreement (kappa 0.61-0.84). CONCLUSIONS: Different groups of doctors vary widely in their views about the need for emergency surgical admission. Good agreement can be reached by consensus discussion. GPs are less likely than surgeons to consider emergency surgical admission necessary.

Attitude of Health Personnel↗
PubMed1997

Surgical practice is evidence based.

BACKGROUND: The quality of surgical research, and particularly the reluctance of surgeons to perform randomized controlled trials, has been criticized. The proportion of surgical treatments supported by satisfactory scientific evidence has not been evaluated previously. METHODS: A 1-month prospective audit was performed of 100 surgical inpatients admitted under two consultants in a general surgical/vascular unit at an urban teaching hospital; the main illness and interventions were agreed through group discussions in each case. The literature concerning the efficacy of each treatment was reviewed, and the evidence was categorized as: (1) supported by randomized controlled trial evidence; (2) sufficient other evidence of efficacy to make a placebo-controlled trial unethical; or (3) neither of the above. RESULTS: Of the 100 patients studied, 95 (95 per cent confidence interval (c.i.) 89-98) received treatment based on satisfactory evidence (categories 1 and 2) and, of these, 24 patients (95 per cent c.i. 17-35) received treatments based on randomized controlled trial evidence and 71 had treatments based on other convincing evidence (95 per cent c.i. 62-80). CONCLUSION: Inpatient general surgery is 'evidence based', but the proportion of surgical treatments supported by randomized controlled trial evidence is much smaller than that found in general medicine. Some reasons for this are clear, but the extent to which surgical practice needs to be reevaluated is not. Current methods for classifying and describing evidence in therapeutic studies need improvement.

Emergencies↗
PubMed1996

Randomized clinical trial of breast irradiation following lumpectomy and axillary dissection for node-negative breast cancer: an update. Ontario Clinical Oncology Group.

BACKGROUND: Breast-conservation surgery is now commonly used to treat breast cancer. Postoperative breast irradiation reduces cancer recurrence in the breast. There is still controversy concerning the necessity of irradiation of the breast in all patients. PURPOSE: We present an update of results from a randomized clinical trial designed to examine the efficacy of breast irradiation following conservation surgery in the treatment of women with axillary lymph node-negative breast cancer. The patients were enrolled from April 1984 through February 1989. Initial results were published in 1992 after a median follow-up time of 43 months. It was reported that recurrence of cancer in the breast occurred in 5.5% of the patients who received breast irradiation compared with 25.7% of those who did not. No difference in survival was detected between the two treatment groups. Now that the median patient follow-up has reached 7.6 years, the trial end points have been re-examined and an attempt has again been made to identify a group of patients at low risk for recurrence of cancer in the breast. METHODS: Eight hundred thirty-seven patients with node-negative breast cancer were randomly assigned to receive either radiation therapy (n = 416) or no radiation therapy (n = 421) following lumpectomy and axillary lymph node dissection. The cumulative local recurrence rate as a first event, distant recurrence (i.e., occurrence of metastasis) rate, and overall mortality rate for the treatment groups were described by the Kaplan-Meier method and compared with the use of the logrank test. The Cox proportional hazards model was used to adjust the observed treatment effect for the influence of various prognostic factors (patient age, tumor size, estrogen receptor level, and tumor histology) at study entry on the outcomes of local breast recurrence, distant recurrence, and overall mortality. All P values resulted from the use of two-tailed statistical tests. RESULTS: One hundred forty eight (35%) of the nonirradiated patients and 47 (11%) of the irradiated patients developed recurrent cancer in the breast (relative risk for patients in the former versus the latter group = 4.0; 95% confidence interval = 2.83-5.65; P < .0001). Ninety-nine (24%) of the patients in the former group have died compared with 87 (21%) in the latter group. Age (< 50 years), tumor size (> 2 cm), and tumor nuclear grade (poor) continued to be important predictors for local breast relapse. On the basis of these factors, we were unable to identify a subgroup of patients with a very low risk for local breast cancer recurrence. Tumor nuclear grade, as previously reported, and tumor size were important predictors for mortality. CONCLUSIONS: Breast irradiation was shown to reduce cancer recurrence in the breast, but there was no statistically significant reduction in mortality. A subgroup of patients with a very low risk for local breast recurrence who might not require radiation therapy was not identified.

Adult↗
PubMed1996

Surgical research.

Explore the source record for details and available documents.

General Surgery↗
PubMed1996

D2 gastrectomy: lessons from a prospective audit of the learning curve.

A 3-year prospective study of the learning curve for D2 gastrectomy was carried out by one surgeon beginning to perform the operation independently after intensive specialist training. Some 38 patients were treated; there were four postoperative deaths and 22 patients had complications. Postoperative morbidity decreased significantly with time (rS = -0.38, P = 0.02, 95 per cent confidence interval -0.62 to -0.07). The physiological component of POSSUM (Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity) was significantly lower in the third year (median value 15, 16 and 14 for years 1, 2 and 3, n = 31, chi 2 = 7.5, 2 d.f., P = 0.02, Kruskal-Wallis test), but the operative POSSUM scores and the number of lymph nodes found were not decreased (median operative POSSUM score 19, 18 and 21, n = 31, chi 2 = 0.2, 2 d.f., P = 0.91, Kruskal-Wallis test). The results suggest a learning curve lasting about 18-24 months or 15 to 25 procedures before a plateau is reached. Improved results were associated with changes in case selection and operative tactics but not with reduced extent of lymphadenectomy. D2 gastrectomy should be restricted to specialist centres where adequate training and supervision can be provided during the learning curve.

Female↗
PubMed1996

Induction of tumour cell shedding into effluent venous blood breast cancer surgery.

Surgeons have long been concerned that cancer may be disseminated by shedding of tumour cells into the bloodstream during surgery. Early claims that cancer operations induced an increase in the number of tumour cells shed into the circulation were subsequently discredited, and the issue has remained unresolved. We used immunocytochemistry for cytokeratins to detect tumour cells in effluent blood from breast carcinomas in 18 patients undergoing surgery. Tumour cells were detectable in 6/18 patients during surgery, in only one patient before operation and in none post-operatively (P = 0.025). Circulating cells were associated with vascular invasion within the primary tumour (P = 0.032). No cytokeratin-positive cells were found in blood from ten normal volunteers or four patients undergoing surgery for other breast conditions. These results confirm that cancer surgery in humans results in an increase in the shedding of tumour cells into the circulation. The implications for prognosis and practice should be determined by larger prospective studies.

Breast Neoplasms↗
PubMed1996

Gastric cancer.

We are gaining a clearer insight into the causes and mechanisms of gastric carcinogenesis, and may be able to reduce the incidence in the future by Helicobacter pylori eradication, perhaps in conjunction with nutritional supplements. The work required to establish this kind of prevention programme still has a long way to go. Surveillance and early detection are a key area, and current hopes rest with an increasingly low threshold for gastroscopy together with improved awareness in both patients and general practitioners. Identification of a high-risk group for surveillance would be a major advance, and may become possible due to advances in molecular biology. In terms of treatment, surgery remains the mainstay, but for useful analysis of its' efficacy, uniform and detailed pathological staging is vital. Pre-operative assessment has improved greatly in recent years, resulting in fewer nontherapeutic laparotomies, thanks to a combination of improved imaging techniques and laparoscopy. Limited endoscopic surgery is now feasible for very early disease. The extent of radical surgery remains controversial: a strong argument can be made for concentrating this kind of surgery in the hands of a limited number of specialist units who will have the numbers and the expertise to answer the outstanding questions. Chemotherapy has yet to prove its value, but there are hopes that the newest regimes may do this. Treatment results in the West remain unsatisfactory, but they have improved in the last two decades, and should be capable of considerable further improvement.

Aged↗
PubMed1995

Association between tumour angiogenesis and tumour cell shedding into effluent venous blood during breast cancer surgery.

Tumour angiogenesis is a powerful prognostic indicator in breast cancer. Shedding of tumour cells into the bloodstream is essential for haematogenous metastasis. The relation between cell shedding and angiogenesis in human cancer is not known. We studied vascular density and cell shedding in 16 women undergoing breast cancer surgery. Circulating cells were found in one patient before, in six during, and none after operation. Vascular density was related to detection of circulating tumour cells during surgery (correlation coefficient for first intraoperative sampling = 0.56, p = 0.024, 95% CI 0.08 to 0.83). Tumour cell shedding during surgery is related to vascular density; the relevance of this relation to the prognostic significance of vascular density in breast cancer merits further study.

Breast Neoplasms↗
PubMed1995

New method to evaluate the therapeutic value of lymph node dissection for gastric cancer.

The results of 1281 potentially curative resections for advanced gastric cancer performed at the National Cancer Center Hospital between 1972 and 1986 were studied using a novel approach which circumvents the stage migration phenomenon. The incidence of metastasis and the 5-year survival rate of patients with positive nodes were calculated independently for each lymph node 'station', without any reference to overall pathological nodal stage. The therapeutic value of extended lymph node dissection was estimated by multiplication of incidence of metastasis and percentage 5-year survival rate of patients with metastasis for each station. The incidence of metastasis ranged from 2.4 per cent to 66 per cent and the 5-year survival rate of affected patients from 0 to 58.7 per cent in perigastric stations, depending on the site of the primary tumour. The incidence of metastasis was between 3.0 per cent and 44.4 per cent in the second tier of nodes (n2), and the 5-year survival rate ranged from 0 per cent to 47.5 per cent. The majority of second-tier stations showed evidence of benefit from node dissection.

Gastrectomy↗
PubMed1995

Developing a course on principles of stoma care.

Hospital and community nurses may see relatively few patients with stomas and thus feel unprepared to care for them. The first short course on stoma care available in Scotland has been set up by specialist nurses to help their colleagues to understand the principles of care. The aim of the course is to produce a network of informed nursing professionals in this field.

Community Health Nursing↗
PubMed1994

Should general surgeons treat gastric carcinoma? An audit of practice and results, 1980-1985.

An audit of treatment of gastric carcinoma was conducted in a major general hospital unit in the UK over a 5-year period. In all, 206 patients (114 men, 92 women) with a mean age of 68 years were treated. Operation was performed in 150 patients; 87 underwent gastrectomy with 31 procedures appearing potentially curative. Most tumours were advanced at diagnosis: 92 were stage IV and 34 stage IIIB, with 42 tumours at earlier stages. After the 87 gastrectomies anastomotic leakage occurred in 16 patients (18 per cent) and there were 14 deaths (16 per cent). The rates of resectability, inadequate resection, anastomotic leakage and postoperative mortality varied considerably between surgeons. The 5-year survival rate was 5 per cent overall, 11 per cent after gastrectomy and 32 per cent following curative resection. The results of treatment of gastric cancer by general surgeons are poor and show marked variation between operators. The declining incidence of the disease makes prospective audit difficult. Treatment by fewer surgeons specializing in this area might improve the outcome.

Adult↗
PubMed1994

Streptokinase inhibits pulmonary tumor seeding in an animal experimental model.

One aspect of the metastatic process involves entrapment of tumor cells within the microcirculation of organs in a "fibrin-platelet mesh." We postulate that destruction of this mesh by fibrinolysis might discourage tumor seeding, thereby inhibiting metastasis. To study this hypothesis, the effect of intravenous streptokinase on pulmonary tumor seeding was examined in a rodent model. In vitro experiments demonstrated that streptokinase had no cytotoxic or cytostatic effect on the Mtln3 cell line. Pharmacokinetic studies showed that at 30,000 U/kg, streptokinase caused systemic fibrinolysis in the Fischer rat, as demonstrated by the thrombin time and fibrin plate lysis assay. Streptokinase administered at this dose, 30 min after tumor cell injection, caused a significant decrease in pulmonary tumor seeding (median 23.0 in the streptokinase-treated group vs. 67.5 in untreated controls, P < 0.0001, Mann-Whitney U-test). Analysis of fibrin degradation products in the streptokinase-treated group suggested that this effect might be secondary to fibrinolysis. The implications of these findings are discussed.

Adenocarcinoma↗
PubMed1994

Nonsurgical treatment of liver metastases.

Experimental studies demonstrate that angiotensin II and somatostatin analogues have some ability to redirect hepatic arterial blood flow toward liver metastases. Albumin microspheres and liposomes are both effective to animal models in enhancing intra-arterial drug delivery to tumor tissue. Clinical studies show that such strategies can also improve drug targeting in humans. Clinical trials of intrahepatic arterial chemotherapy demonstrate definite response and survival benefits, but toxicity can be considerable, and progression of extrahepatic disease remains an unsolved problem. Selective means of delivering radiation, biologic therapy, and thermal energy to liver metastases are possible alternative nonsurgical treatments that merit further investigation.

Animals↗