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Biomedical subjects

D Cunningham

Publications and source records attributed to D Cunningham.

At least 145 records · Page 8Linked to original sources
PubMed1996

Measurement of plasma 5-fluorouracil by high-performance liquid chromatography with comparison of results to tissue drug levels observed using in vivo 19F magnetic resonance spectroscopy in patients on a protracted venous infusion with or without interferon-alpha.

PURPOSE: To measure plasma 5-fluorouracil (5-FU) levels using high-performance liquid chromatography (HPLC) and compare the findings to the tissue metabolism of 5-FU evaluated using 19F magnetic resonance spectroscopy (MRS), during a protracted venous infusion (PVI) with or without interferon-alpha. METHODS: Patients receiving PVI 5-FU (300 mg/m2/day) with or without interferon-alpha (5 x 10(6) units 3 times per week), had 2 weekly plasma 5-FU levels evaluated using reverse-phase ion-pairing HPLC. These samples were drawn just prior to the patient undergoing MRS using a 1.5T Siemens Magnetom whole body magnetic resonance system with a 16 cm surface coil placed over normal liver or metastatic tumour. Semi-quantitated MRS values were compared with the plasma 5-FU levels using linear regression analysis. Data were available from patients given interferon-alpha with PVI 5-FU from day 1 or at the point of 5-FU refractory disease. RESULTS: A total of 30 patients were studied. Plasma 5-FU concentrations while on a protracted venous infusion varied from <25 ng/ml (0.192 mu M) to 25,000 ng/ml (192 mu M). A high plasma 5-FU concentration was associated with an increase in patient toxicity. Patients given interferon-alpha with 5-FU had higher median plasma 5-FU levels higher than patients on 5-FU alone (6138 vs. 218 ng/ml; p = 0.03). There was no correlation between the plasma 5-FU concentration and tumour response. A comparison of the plasma 5-FU data to the MRS studies in normal liver revealed a positive correlation between plasma 5-FU and liver catabolite signal (r = 0.68; p = 0.016) but a negative correlation with the log plasma 5-FU concentration and 5-FU liver signal (r = -0.63; p = 0.022). The patients experiencing toxicity, in addition to having a higher plasma 5-FU concentration did not exhibit a liver 5-FU signal, while the reverse was true for those having no toxicity. CONCLUSIONS: Plasma 5-FU levels may show greater interpatient variation when given as a protracted venous infusion. Levels of 5-FU correlated with treatment toxicity but not with anti-tumour activity. The addition of interferon-alpha to 5-FU increases plasma 5-FU levels. MRS findings suggest patients with low plasma 5-FU levels have higher 5-FU levels in normal liver tissue than in those with higher plasma levels.

Antimetabolites, Antineoplastic↗
PubMed1996

'Tomudex' (ZD1694): a novel thymidylate synthase inhibitor with clinical antitumour activity in a range of solid tumours. 'Tomudex' International Study Group.

BACKGROUND: Anti-metabolites such as methotrexate (MTX) and 5-fluorouracil (5-FU) have been used clinically for many years. Although their effects are partly due to thymidylate synthase (TS) inhibition, they also have non-specific, non TS effects on RNA and purine synthesis. Direct and specific TS inhibitors therefore presented an attractive research target. Collaborative research between the Institute of Cancer Research and Zeneca Pharmaceuticals led to the design of specific folate based quinazoline TS inhibitors. ZD1694 ('Tomudex'), the first of these drugs reaching advanced clinical development, is currently completing phase III studies. DESIGN: Eight phase II trials were carried out using 'Tomudex', 3.0 mg/m2, given as a short 15-minute infusion 3-weekly. RESULTS: 'Tomudex' demonstrates activity in a range of tumour types, most notably advanced colorectal and breast cancer (objective response rate 26%) and has acceptable toxicity: the most common WHO grade 3 and 4 adverse events were self-limiting reversible increases in liver transaminases, transient leucopenia, diarrhoea, nausea and vomiting and tiredness or malaise. Mucositis/stomatitis, alopecia and skin toxicity were notable for their low incidence and mild intensity. CONCLUSIONS: 'Tomudex' represents the successful culmination of a rational drug design programme, and shows promise as a new cytotoxic for the treatment of colorectal cancer. Further studies in other tumour types are planned.

Adult↗
PubMed1996

Optimum anti-emetic therapy for cisplatin induced emesis over repeat courses: ondansetron plus dexamethasone compared with metoclopramide, dexamethasone plus lorazepam.

BACKGROUND: This study was undertaken to compare the efficacy and tolerability of ondansetron plus dexamethasone (O + D) with metoclopramide plus dexamethasone plus lorazepam (M + D + L) over three consecutive courses of cisplatin chemotherapy. PATIENTS AND METHODS: This was an international, multicentre, double-blind, double-dummy, parallel group study. O+D patients were randomised to receive ondansetron 8 mg intravenously (i.v.) plus dexamethasone 20 mg i.v. prior to cisplatin (50-100 mg/m2) chemotherapy. On the following 4 days they were treated with ondansetron 8 mg bd orally and dexamethasone 4 mg bd orally. M + D + L patients were randomised to receive metoclopramide 3 mg/kg i.v., dexamethasone 20 mg i.v. and lorazepam 1.5 mg/m2 i.v. (max 3 mg) prior to cisplatin chemotherapy and a further dose of metoclopramide 3 mg/kg i.v. approximately 2 hours following the first dose of metoclopramide. Treatment for the following 4 days was metoclopramide 40 mg tds and dexamethasone 4 mg bd orally. Two hundred and thirty-seven patients were recruited into the study (117 patients received O + D and 120 received M + D + L). RESULTS: On the first course chemotherapy, O + D was significantly superior to the M + D + L regimen for complete control of emesis (days 1-5, 54% versus 37%, respectively, P = 0.014). This was maintained over the three treatment cycles; 38% of O + D and 20% of M + D + L patients remained free of emesis (P = 0.003). Maintenance of control of nausea grade as none or mild on days 1-5 over the three courses was significantly better in the O + D group (48%) than in the M + D + L (26%, P = 0.003). The most commonly occurring adverse events in the O + D group were constipation (25%) and headache (19%). In the M + D + L group drowsiness (38% of patients), malaise/fatigue (16% of patients), constipation (13% of patients), anxiety (11% of patients) and dizziness (10% of patients) were the most commonly reported adverse events. Extrapyramidal symptoms were reported by 20% of patients in the M + D + L group. Despite the inclusion of lorazepam, 14% of patients in the M + D + L group were withdrawn from the study due to extrapyramidal symptoms, which in the opinion of the investigators, were probably or almost certainly related to study medication. CONCLUSION: This study show that O + D is significantly more effective and better tolerated than M + D + L for the control of emesis and nausea over a series of three courses of cisplatin chemotherapy.

Adult↗
PubMed1996

Optic neuropathy following simulation of orbital hemorrhage in the nonhuman primate.

The goal of the study was to determine, using a nonhuman primate (NHP) model, the minimum duration of elevated intraocular pressure (IOP) (induced by an inflated catheter) necessary to produce significant visual system deficits. In Old World monkeys (Macaca mulatta), a catheter was placed retrobulbarly in one orbit and inflated with saline for either 180 min (10 monkeys) or 240 min (six monkeys subjects). Baseline color fundus photographs, monochromatic photography, fluorescein angiography, and IOP measurements were performed preoperatively and at either 2, 4, or 6 weeks postoperatively on both eyes of each monkey prior to killing and histological analysis. Optic neuropathy was demonstrated in eight of these NHPs. In the two most severe cases (240 min inflation condition), complete nerve fiber atrophy with central retinal artery occlusion was observed. Sector nerve fiber atrophy, extending from the temporal disc to beyond the macula, was noted in the other six monkeys, five of which were in the 180 min inflation condition. Thus, optic neuropathy, sufficient to produce visual loss, was noted following increased IOP (> or = 50 mm Hg) for 180 min or 240 min. These data emphasize the need for timely intervention to mitigate the potential detrimental effects of retrobulbar hemorrhage when it occurs in humans.

Animals↗
PubMed1996

Radiographic interpretation by nurse practitioners in a minor injuries unit.

OBJECTIVE: To compare nurse practitioners with senior house officers (SHOs) for their ability to request and interpret correctly a limited range of x ray views of patients attending a minor injuries unit. DESIGN: Retrospective analysis of case records. METHODS: 150 accident and emergency (A&E) records with x ray requests were randomly selected from the SHOs' first, second, and third 2-month period of their 6-month appointments; 150 record cards were randomly selected from a nearby minor injuries unit over the same period. Copies of the records were reviewed blind and a decision made as to whether x ray requests were appropriate; x ray interpretation was compared with that of a consultant radiologist. RESULTS: 106 x rays were taken on the MIU patients (71%) and 124 on the A&E patients (83%). There was no statistically significant differences in the ability of the nurse practitioners and the SHOs to request and interpret appropriate x rays. In both groups the decision to carry out an x ray was considered appropriate in 70% of patients; x rays were positive in about one third. The sensitivity of radiological interpretation was 93% in both groups, and there were 2% missed positives. CONCLUSIONS: Appropriately trained nursae practitioners are at least as good as SHOs in recognising the need for an x ray and are as competent in their interpretation.

Adolescent↗
PubMed1996

Noninvasive monitoring of tumor metabolism using fluorodeoxyglucose and positron emission tomography in colorectal cancer liver metastases: correlation with tumor response to fluorouracil.

PURPOSE: To investigate and measure the metabolism of colorectal cancer liver metastases using 18F-fluorodeoxyglucose positron emission tomography (FDG PET), before and during the first month of chemotherapy. The findings were compared with tumor outcome conventionally assessed using changes in tumor size. PATIENTS AND METHODS: Patients with colorectal cancer liver metastases were treated with fluorouracil (5FU) as a protracted venous infusion (300 mg/m2/d), with or without interferon-alpha 2b for two 10-week blocks separated by a 2-week break. Before and at 1 to 2 and 4 to 5 weeks on treatment, FDG PET scans were performed. Patients fasted, were injected intravenously with FDG (50 to 100 MBq), and scanned using a large-area positron camera; the image data was processed such that regions of interest could be identified. The results were expressed as a ratio of FDG uptake in the tumor and normal liver (T:L) or as a semiquantitative standardized uptake value (SUV). These measures were compared with the tumor dimensions measured on a computed tomographic (CT) scan performed at 12 weeks from commencement of chemotherapy. RESULTS: Twenty patients were studied; however, two did not have assessable liver metastases. Objective partial responses were observed in 11 of 18 patients. A total of 27 metastatic lesions were assessable. Pretreatment T:L ratios and SUVs did not correlate with tumor response, although response was associated with lower 1- to 2-week (1.84 v 2.17; t=2.667; P < .02) and 4- to 5-week (1.36 v 2.28; t=5.02; P < .001) T:L ratios, and 4- to 5-week (3.57 v 4.95; t=2.492; P < .05) SUVs. Expressed as a percent of the baseline values of the T:L ratio, responding lesions had a greater reduction in metabolism (67% v 99%; t=7.53; P < .001). The 4- to 5-week T:L ratio was able to discriminate response from nonresponse both in a lesion-by-lesion and overall patient response assessment (sensitivity 100%; specificity 90% and 75%, respectively). CONCLUSION: Positron emission tomography used to evaluate the uptake of FDG in tumors yields data that correlate with the antitumor effect of chemotherapy in patients with liver metastases from colorectal cancer.

Antimetabolites, Antineoplastic↗
PubMed1996

ZD1694: A novel thymidylate synthase inhibitor with substantial activity in the treatment of patients with advanced colorectal cancer. Tomudex Colorectal Study Group.

PURPOSE: Tomudex (ZD1694; Zeneca Ltd, Macclesfield, United Kingdom) appears to have a favorable toxicity profile (defined in phase I studies) and antitumor activity in a broad range of epithelial tumors. We report here the results of a large phase II study of Tomudex in advanced colorectal cancer (CRC). PATIENTS AND METHODS: One hundred seventy-seven patients were entered onto the study between October 1992 and September 1993. Patients were required to have advanced CRC without prior chemotherapy (adjuvant chemotherapy was permissible) and at least one measurable lesion. Tomudex (ZD1694) was administered at a dose of 3 mg/m2 intravenously once every 3 weeks in the absence of toxicity or disease progression. Patients were assessed for objective response, progression, and survival. RESULTS: Of 177 patients entered onto the study, 5% had received prior adjuvant chemotherapy and 83% had liver metastases. Objective responses were seen in 26% of patients (95% confidence interval, 19% to 33%; four complete responses [CRs] and 41 partial responses [PRs]) while median time to progression was 4.2 months and median survival 9.6 months. All sites were audited, and responses were reviewed by an independent panel. Common toxicities included mild reversible transaminitis, nausea and vomiting, and asthenia or flu-like symptoms, and World Health Organization (WHO) grade 3 and 4 leukopenia and diarrhea were seen in 6% and 9.8% of patients, respectively. Stomatitis and alopecia were common. CONCLUSION: In this large multicenter phase II study of patients with advanced CRC, interesting activity was seen (objective response rate, 26%). In addition, Tomudex has an acceptable toxicity profile and a convenient dosing schedule (single intravenous injection every 3 weeks) and thus appears to offer real potential as a novel agent for the treatment of patients with advanced CRC.

Adult↗
PubMed1996

Randomized trial assessing the addition of interferon alpha-2a to fluorouracil and leucovorin in advanced colorectal cancer. Colorectal Cancer Working Party of the United Kingdom Medical Research Council.

PURPOSE: To determine the effects of interferon alpha-2a (IFN alpha) on the efficacy and toxicity of fluorouracil (FUra) and leucovorin (LV) in patients with advanced colorectal cancer. PATIENTS AND METHODS: Two hundred sixty chemotherapy-naive patients were randomized to FUra/LV alone or FUra/LV plus IFN alpha. All patients received: LV 200 mg/m2 intravenous (IV) infusion over 2 hours, then FUra 400 mg/m2 i.v. bolus plus 400 mg/m2 i.v. infusion over 22 hours, all repeated on day 2. Treatment was every 2 weeks for up to 12 cycles. Patients randomized to IFN alpha received 6 x 10(6) IU subcutaneously every 48 hours throughout. Objective response (OR) and toxicity were assessed conventionally; in addition, palliative benefit and adverse effects were assessed using quality-of-life (QoL) questionnaires. RESULTS: There were no differences in OR rate, progression-free survival, or overall survival. OR rates in assessable patients were as follows: FUra/LV alone (n = 104), complete or partial response (OR) = 27%, no change (NC) = 34%; FUra/LV/IFN alpha (n = 101), OR = 28%, NC = 30%. Median survival was 10 months in both arms. Dose-limiting FUra toxicities were not significantly increased by co-administration of IFN alpha, and the delivered FUra dose-intensity was not significantly reduced. However, QoL was adversely affected: patients on IFN alpha were less likely to report improvement in pretreatment physical and psychologic symptoms, and more likely to report new or worsening symptoms. CONCLUSION: IFN alpha, at a dose that impaired QoL, did not improve the efficacy of FUra/LV. The power of this trial is sufficient to exclude with 95% confidence a benefit of 15% in OR or 10 weeks in median survival. Accordingly, we cannot recommend the use of IFN alpha as a clinical modulator of FUra/LV in the treatment of advanced colorectal cancer.

Adult↗
PubMed1996

Comparison of interferon tolerance after autologous bone marrow or peripheral blood stem cell transplants for myeloma patients who have responded to induction therapy.

Interferon (INF) has been incorporated as part of maintenance therapy after high dose treatment in order to make remissions more durable. In this study we have compared peripheral blood stem cell transplant (PBSCT) versus autologous bone marrow transplant (ABMT) with respect to INF tolerance. Thirty nine PBSCT patients have been compared to 37 ABMT patients for INF tolerance. This is followed by a comparison of 15 PBSCT patients versus 21 ABMT patients for engraftment details, response and survival. INF was started at a median of 61 days in the PBSCT and 58 days in the ABMT patients (P = NS). It was well tolerated in both groups without a significant difference in toxicity in the two arms. Engraftment was more rapid in the PBSCT patients with platelet recovery being significantly faster. Response and survival showed a favourable trend for ABMT patients though statistical significance was not reached and the cost of PBSCT was 12% cheaper. We were thus able to conclude that PBSCT grafts were as durable and could tolerate INF just as well as ABMT. Engraftment was more rapid and the procedure of PBSCT was also cheaper. Further studies with a larger group of patients will be required before comments on the efficacy of treatment can be made.

Adult↗
PubMed1996

Inflammation of solar keratoses following systemic 5-fluorouracil.

Several cutaneous reactions have been reported following systemic 5-fluorouracil (5-FU) for the treatment of malignancies. We report three patients with marked inflammation of the solar keratoses following continuous infusion of 5-FU for solid tumours. This side-effect with 5-FU, only previously reported in three other cases, was beneficial as most solar keratoses cleared following the inflammatory reaction. The reasons why 5-FU should be selectively taken up by solar keratoses are discussed.

Aged↗
PubMed1995

Sepsis reduces isoflurane MAC in a normotensive animal model of sepsis.

Patients with sepsis often require anaesthesia for surgical procedures. Anaesthesia can be unpredictable and the most haemodynamically stable agents are used. No data are available for the minimum alveolar concentration (MAC) requirements in such patients or in animal models of sepsis. We have characterized the effect of sepsis on the MAC of isoflurane in a normotensive rodent model of sepsis. The minimum inhibitory concentration (MIC) of isoflurane to an identical stimulus was determined for rodents subjected to caecal ligation and perforation (CLP n = 8), or sham laparotomy (n = 7). The calculated MAC of isoflurane was reduced in the septic animals compared with the sham animals (MAC of isoflurane, CLP = 0.8%, sham = 1.4% P < 0.003). No statistical differences were found in the haemodynamic variables measured in either group. Isoflurane leads to haemodynamic stability during anaesthesia in this animal model of sepsis. However, the MAC requirement for isoflurane is reduced by sepsis.

Anesthetics, Inhalation↗
PubMed1995

Regenerated hair cells in the European starling: are they more resistant to kanamycin ototoxicity than original hair cells?

Previous work from our laboratory [Marean et al. (1993) Hear. Res. 71, 125-136] has shown that a 10 day dose of 200 mg/kg/day kanamycin produced damage to the basal 34% of the starling basilar papilla. We also observed that repeating the dosing schedule following a 4 month survival period resulted in significantly less damage to the regenerated auditory epithelium. The present study investigated whether or not this apparent resistance was the result of a tendency for regenerated hair cells to be less susceptible to kanamycin ototoxicity, or if other, systemic factors may be involved. Eight European starlings were given subcutaneous injections of 200 mg/kg/day kanamycin for 10 days. Serum levels of kanamycin were measured at the time of sacrifice for all birds, and the basilar papillae of all birds were examined by scanning electron microscopy (SEM). Two of these birds (Group 1) were sacrificed immediately following the dosing period. Two of the birds were allowed to survive for 60 days (Group 2). Two of the birds were redosed with 200 mg/kg/day for 10 days after 60 days survival (Group 3). Finally, two birds were redosed with 250 mg/kg/day until serum levels of kanamycin were the same as Group 1 when sacrificed (> 9 micrograms/ml). The SEM results showed that the regenerated auditory epithelium of the birds dosed a second time sustained less damage compared to previously untreated ears, even though the dosing regimen was the same (Group 3 versus Group 1). The regenerated auditory epithelium of birds dosed a second time sustained the same damage as previously untreated animals when the dosage was increased to attain similar serum levels (Group 4 versus Group 1). These results suggest metabolic changes occur in the starling in response to the initial dose of kanamycin which do not necessarily involve changes in hair cell resistance to ototoxicity.

Animals↗
PubMed1995

A single-blind, randomised, vehicle-controlled dose-finding study of recombinant human granulocyte colony-stimulating factor (lenograstim) in patients undergoing chemotherapy for solid cancers and lymphoma.

This study evaluated the effect of glycosylated recombinant human granulocyte colony-stimulating factor (rHuG-CSF; lenograstim) on neutrophil granulocyte counts and on cells of other haematopoietic lineages in 66 patients with solid cancer or lymphoma who received myelosuppressive chemotherapy. Beginning 1 day after completion of chemotherapy, patients received lenograstim (at dosages of 0.5, 2, 5 or 10 micrograms/kg) or vehicle subcutaneously once daily for 14 consecutive days. Compared with vehicle, lenograstim significantly accelerated neutrophil recovery after chemotherapy in a dose-dependent manner. Mean neutrophil counts recovered to > 1.0 x 10(9) cells/l by day 13 in the vehicle group compared with days 11, 10, 8 and 7 in the 0.5, 2, 5 and 10 micrograms/kg lenograstim groups, respectively. Doses of 0.5 and 2 micrograms/kg of lenograstim had a significant effect on the duration of neutropenia (< 1.0 x 10(9) cells/l), the area under the absolute neutrophil count (ANC) curve and the time to ANC nadir. The dose of 5 micrograms/kg additionally decreased the total area of neutropenia and gave the narrowest range of values for all neutrophil parameters, while the 10 micrograms/kg dose brought no added benefit. A dose-response effect of lenograstim on time to neutrophil recovery was observed both for patients who received chemotherapy on a single day (n = 35) and for those who received chemotherapy over several days (n = 29). Based on these findings, a dose of 5 micrograms/kg/day was chosen for further trials.

Adjuvants, Immunologic↗