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Biomedical subjects

J F Bishop

Publications and source records attributed to J F Bishop.

At least 55 records · Page 3Linked to original sources
PubMed1996

Concurrent radiotherapy and continuous ambulatory infusion 5-fluorouracil in advanced head and neck cancer.

Patients with locally advanced stage 3 or 4 recurrent squamous cell carcinoma of the head and neck received 5-fluorouracil (5-FU) 200 or 300 mg/m2/day by prolonged ambulatory infusion concomitantly with radiotherapy (60-66 Gy) to the primary site and neck nodes in 30-33 fractions at five fractions per week, boosting to smaller volumes after 60 Gy. Of 39 patients, the complete response rate was 82% (95% CI: 67-93%). The estimated percentage without failure at 2 years was 59% (S.E. 8%) and at 4 years was 50% (S.E. 8%). Estimated head and neck cancer specific survival was 64% (S.E. 8%) at 2 years and 52% (S.E. 8%) at 4 years. Acute toxicities included moist desquamation in 49% and dry desquamation in 28%, confluent mucositis in 56% and patchy mucositis in 44%. Late effects, more than 6 months after completing treatment, assessed in 35 patients, included severe salivary dysfunction in 3 patients and moderate in 21, severe osteonecrosis in 4 patients and moderate toxicity in subcutaneous tissues in 13, skin in 3 and mucosa in 2 patients. It is feasible to give continuous 5-FU concurrently with radiotherapy in locally advanced or recurrent head and neck cancer, albeit with increased toxicity. The response rate and survival obtained in this trial justify further investigation of the combined treatment in a randomised trial.

Adult↗
PubMed1996

Carboplatin dosing based on measurement of renal function--experience at the Peter MacCallum Cancer Institute.

BACKGROUND: Carboplatin is used in treating many types of cancer. Because renal excretion is the major variable determining the pharmacokinetics of this drug, a dosing formula based on glomerular filtration rate (GFR) has been proposed and is being increasingly used in carboplatin dosing. This method of dosing is critically dependent on accurate measurement of GFR. AIMS: To report the experience at a single major oncology centre of carboplatin dosing based on GFR, and comparisons of different methods of measuring renal function for use in this dosing method. METHODS: An initial group of patients (n = 24) was studied where GFR was measured by Cr51EDTA clearance and compared to Tc99mDTPA clearance, measured 24 hour urine creatinine clearance and the Cockcroft and Gault formula. The carboplatin area under the plasma concentration versus time curve (AUC) was calculated using total platinum measured in a single blood sample assayed by flameless atomic absorption spectrophotometry. A subsequent patient group (n = 16) was then studied using Tc99mDTPA clearance to measure GFR. RESULTS: Carboplatin dosing using Cr51EDTA clearance to measure GFR was accurate (< 25% difference between planned and measured AUC) in 87% of samples. Estimation of renal function using the Cockcroft and Gault formula correlated with Cr51EDTA clearance only in patients with GFR < 100 mL/minute. The measured 24 hour urine creatinine clearance did not correlate with Cr51EDTA clearance. Using Tc99mDTPA clearance to measure GFR, carboplatin dosing was accurate in 81% of samples. Across a GFR range of 42-239 mL/minute, the Cr51EDTA and Tc99mDTPA clearance were closely correlated (r = 0.98, slope of regression line = 1.02). CONCLUSIONS: Carboplatin dosing using a pharmacological formula based on GFR produces accurate targeting of the carboplatin AUC. Tc99mDTPA clearance can be used to measure GFR instead of Cr51EDTA clearance, which is both more convenient and has potential cost savings. Estimates of renal function using the Cockcroft and Gault formula or measured 24 hour creatinine clearance are insufficiently accurate to use for carboplatin dosing.

Antineoplastic Agents↗
PubMed1996

Phase II trial of a 3-hour infusion of paclitaxel in previously untreated patients with advanced non-small-cell lung cancer.

PURPOSE: To determine the antitumor activity and toxicity of paclitaxel administered as a 3-hour infusion in patients with advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Fifty-one patients with advanced measurable or assessable NSCLC and performance status 0 to 2 who had not received prior chemotherapy were treated with paclitaxel 175 mg/m2 over 3 hours with premedication. Cycles were repeated every 3 weeks for a maximum of nine cycles. Most patients had prior radiotherapy (57%), extrathoracic metastatic disease (65%), and measurable disease (75%). Twenty-two percent had previously untreated stage III disease. RESULTS: The objective response rate was five of 51 (10%; 95% confidence interval, 3% to 21%). No subgroup with a higher response rate could be identified. There were no complete responses (CRs) and all responses lasted less than 5 months. Treatment was well tolerated with brief World Health Organization (WHO) grade IV neutropenia in only 16% of patients. Grade III/IV myalgia/athralgia occurred in 22% of patients. No significant hypersensitivity reactions occurred. CONCLUSION: The antitumor activity of this dose and schedule appears inferior to that reported in previously published phase II trials in NSCLC that used higher doses of paclitaxel infused over 24 hours, although confidence intervals for response overlap. Determining the optimal dose and schedule for using paclitaxel in NSCLC requires further investigation, and these results should caution against using shorter infusions outside appropriate clinical trials.

Adult↗
PubMed1996

Does it matter how remission is achieved in acute leukemia?

Patients fail to be cured of acute myeloid leukemia (AML) because they develop absolute or relative resistance to antileukemic drugs such as ara-C (cytarabine) or because they die of complications of bone marrow failure. The Australian Leukemia Study Group (ALSG) has been investigating strategies to improve leukemia control by changing the methods of induction treatment. High-dose ara-C (HIDAC) may overcome ara-C resistance in leukemic blasts, and it has been used as a successful salvage regimen and in postremission therapy. The data from ALSG suggest that a dose-effect relationship exists for ara-C in AML, that the use of HIDAC prolongs remission duration and disease-free survival and that it is tolerable when used as initial induction therapy in patients with de novo AML. A fundamental question still to be answered in ongoing clinical trials is: When should AML treatment be optimally intensified--during the induction phase, immediately after remission, or after 2 to 3 months of preparative regimens, as in some transplantation programs?

Acute Disease↗
PubMed1995

A phase I and pharmacokinetics study of prolonged ambulatory-infusion carboplatin.

A total of 18 patients received 6-week ambulatory infusions of carboplatin in groups at dose levels of 14, 28, 35 and 42 mg/m2 per day. The dose-limiting toxicity was myelosuppression. At 42 mg/m2, three of four patients had WHO grade 4 and one of four had grade 3 neutropenia, whereas two patients had grade 3 thrombocytopenia. At 35 mg/m2, two of five patients had grade 3 neutropenia, whereas one had grade 4 and two had grade 3 thrombocytopenia. Non-hematological toxicities were predominantly gastrointestinal, with 3 of 18 patients experiencing grade 3 emesis. Total and ultrafiltrable platinum (UFPt) were assayed by flameless atomic absorption spectrometry in weekly and post-infusion plasma and urine samples. In plasma, levels of total platinum increased throughout the infusion, and the protein binding slowly increased from 60% platinum bound at week 1 to 90% bound by week 4. Although the UFPt level reached a steady state within 1 week, the concentration did not increase with the dose level, remaining at a mean value of 0.58 +/- 0.24 microM. Renal excretion of platinum accounted for 70 +/- 12% of the dose at steady state. There was a high inter-patient variability in both total body clearance of UFPt (range, 83-603 ml/min) and renal clearance (range, 67-390 ml/min). A terminal elimination half-life of 13-27 h was noted for post-infusion UFPt. Neutropenia was linearly related to the total daily carboplatin dose, but neither neutropenia nor thrombocytopenia could be related to steady-state UFPt or the UFPt area under the concentration-time curve (AUC). The recommended dose for phase II studies is 28 mg/m2 per day.

Adult↗
PubMed1995

Unilateral injury of posterior parietal cortex and spatial learning in hooded rats.

The influences of bilateral or unilateral injuries within the posterior parietal cortex (PPC) upon spatial learning in a water maze were examined in three experiments. Place-learning and response-learning were investigated in a four-alley 'Greek-cross' shaped water maze with extra-maze visual cues available. No differences were detected on any of several measures sensitive to learning between the lesion groups on the place-learning task. Microanalysis of behavior within trials revealed that animals with either bilateral or right unilateral PPC injuries committed significantly more total errors, initial alley entrance ('reference memory') errors, and re-entry ('working memory') errors in the response-learning paradigm than did either the control or left PPC-injured rats. No differences were detected between the latter two groups on these measures. Unilateral lesions resulted in asymmetrical placing responses ipsilateral to the injury 10 days after surgery whereas bilateral injuries resulted in asymmetrical placing with mixed directionality. The acquisition of the response-learning problem in the absence of visual cues was studied on animals prepared with unilateral lesions and housed post-operatively either in isolation or in a 'complex environment.' In the absence of visual cues both right and left PPC-injured rats committed more errors than sham controls, and differential post-surgical housing did not attenuate these impairments. These same animals were trained on the landmark navigation task. Although no differences appeared between the lesion groups, a generalized but transient facilitation of learning was observed in animals housed in the 'complex' environment. Unilateral injuries placed in sham controls failed to disturb retention of the landmark navigation strategy. Because none of the PPC-injured animals were deficient in the landmark task, a result which is contrary to observations in other laboratories, the influence of post-surgical recovery interval upon acquisition of the landmark navigation strategy was explored. Animals were prepared with right PPC injuries and trained following either a 5 or 35 day recovery interval. Only those animals limited to the short recovery interval proved to have a spatial deficit in the landmark task. It is concluded that injuries in the PPC of either hemisphere disturb egocentric spatial functions. However, animals with left PPC injuries are able to compensate by using allocentric visual cues if they are available. It is due to the special role played by the right PPC in complex visuospatial functions that animals with this injury are unable to compensate.

Animals↗
PubMed1995

Scheduling of chemotherapy and radiotherapy in locally advanced non-small cell lung cancer.

In scheduling chemotherapy and radiotherapy for locally advanced non-small cell lung cancer (NSCLC), chemotherapy can be given pre-radiotherapy or concurrently as a single agent or in combination. Optimal scheduling has yet to be established. Optimal pre-radiotherapy for NSCLC requires further development but cisplatin with vinblastine, vindesine, etoposide or navelbine appear the best currently available. A number of new drugs show potential for enhancing radiation effects. Concurrent chemotherapy and radiotherapy has been tested in a number of experimental tumours in cell culture. In these systems cisplatin, carboplatin, 5-fluorouracil, mitomycin-C and other agents appear to improve cell kill compared to chemotherapy alone. Mouse xenograft models allow the study of various concurrent drug and radiation schedules including the effect of radiation with cisplatin, carboplatin, paclitaxel and gemcitabine. In these systems, cisplatin in divided doses shows optimal enhancement with fractionated radiotherapy. There are a number of drug candidates for concurrent chemotherapy and radiotherapy programs. Clinical studies in head and neck cancer, esophageal cancer, small cell lung cancer and NSCLC show promising results with concurrent chemotherapy and radiotherapy. Cisplatin given daily with radiotherapy improved survival in NSCLC compared to cisplatin given weekly with radiotherapy or to radiotherapy alone. To study the toxicity of radiation and concurrent carboplatin, we have studied 170 patients with unresectable locally advanced NSCLC in a 4-arm randomized trial. An analysis of the first 100 patients entered revealed significantly more neutropenia (P < 0.0001) and thrombocytopenia (P < 0.004) with the combined modality arms. Esophagitis was worse on all three experimental arms but was significantly more prolonged with accelerated radiotherapy arms.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

The spectrum of 5-fluorouracil cardiotoxicity.

OBJECTIVE: To report three cases of cardiotoxicity related to the administration of 5-fluorouracil (5-FU) in patients with cancer. CLINICAL FEATURES: Three patients with gastrointestinal malignancies were being treated with combined radiotherapy and chemotherapy regimens. Two patients developed myocardial ischaemia and the other a ventricular arrhythmia in association with 5-FU administration. INTERVENTION AND OUTCOME: All patients survived the cardiac event. No patient was rechallenged with 5-FU. Radiotherapy was continued, achieving a good tumour response. CONCLUSION: Cardiotoxicity is rarely reported with 5-FU. The cardiac events can be life threatening. It is difficult to predict which patients will be affected. Clinicians need to be aware of this potential toxicity and monitor patients appropriately.

Adenoma↗
PubMed1994

Platelet support and the use of cytokines.

Severe thrombocytopenia and clinical bleeding remain major clinical problems in leukemic patients undergoing remission induction and those receiving high dose chemotherapy. Prophylactic platelet transfusions have made a major impact on hemorrhagic deaths over the last 20 years. The effectiveness of platelet transfusions is influenced by a number of clinical factors including the status of the spleen, prior bone marrow transplantation, the presence of disseminated intravascular coagulation and the presence of HLA antibodies. Optimal platelet transfusion therapy requires that transfusions be monitored routinely by post-transfusion counts and that a refractory group be clearly defined. The cytokine granulocyte colony stimulating factor (G-CSF) has not had a clinically significant impact on thrombocytopenia. Granulocyte-macrophage colony stimulating factor (GM-CSF) also probably has little clinical relevance, although in a randomized study, thrombocytopenia was worse in GM-CSF-treated patients. Interleukin-3 (IL-3) can increase platelet count and has the potential to protect against thrombocytopenia in patients receiving chemotherapy. This hypothesis is currently being tested in on-going clinical trials.

Adult↗
PubMed1994

Alternate 5' exons in the rat brain-derived neurotrophic factor gene: differential patterns of expression across brain regions.

Brain-derived neurotrophic factor (BDNF) enhances the survival of dopaminergic neurons and protects them from neurotoxins in vitro. This trophic factor might thus be of therapeutic value for the treatment of Parkinsonian syndromes. The rat BDNF gene consists of several upstream noncoding exons that are alternatively spliced to a common coding exon. To investigate BDNF 5' exons expressed in the adult rat brain, we subjected RNA from cerebellum to 5'-RACE analysis and compared the resulting clones to previously reported 5' exon sequences from rat brain and hippocampus. In addition to known 5' exons, we isolated a BDNF transcript with a novel 5' sequence representing yet another alternate upstream exon in this gene. Quantitative PCR analysis of BDNF mRNAs containing each of the five upstream exons indicated that each of the alternate transcripts is most abundant in the hippocampus, intermediate in the substantia nigra and cerebellum and least abundant in the striatum. However, the magnitude of these differences in expression varied considerably suggesting that BDNF gene transcription in the mature brain is regulated by alternate promoters that are differentially active across regions.

Alternative Splicing↗
PubMed1994

The roles of patient and observer assessments in anti-emetic trials.

The endpoints assessed by both patients and nurses were compared in three anti-emetic studies. In a parallel subjects study, there was no significant difference between the patients' and nurses' assessment of the number of vomiting episodes, but the duration of vomiting, the severity and duration of nausea, and the side-effects of the anti-emetic were given higher scores by the nurses. In two cross-over studies, the patients recorded more vomiting episodes than the nurses, while the nurses recorded more anxiety and sedation than the patients. This resulted in the patients detecting a difference between the side-effects of the anti-emetics being compared that was not apparent from the nurses' forms. Many of the differences reflect differences in the timing and frequency of data collection. Nurses collected data regularly during the assessment period whereas patients reported their experiences only at the completion of 24 h. Both assessments provide useful perspectives on the study outcomes.

Cross-Over Studies↗
PubMed1994

A randomised double blind crossover study of domperidone and prochlorperazine suppositories for controlling emesis in outpatients receiving chemotherapy.

Patients receiving outpatient chemotherapy, without cisplatin, were randomised to receive four doses of either domperidone 60 mg or prochlorperazine 25 mg suppositories every 4 h, starting 30 min before the chemotherapy. They were crossed over for the next chemotherapy cycle. To enable analysis of 100 patients who had received identical chemotherapy in each course, 136 patients were randomised. Patients experienced a higher grade of nausea on domperidone (P = 0.05). Only 18% of patients vomited on domperidone and 14% on prochlorperazine, but the number of vomits was higher on domperidone (P = 0.003) and the duration was significantly increased (P = 0.02). Patients experienced significantly more diarrhoea on domperidone (P < 0.0001), although it was predominantly mild. Patients were significantly more sedated on prochlorperazine on the second course (P = 0.006), but not on the first course (P = 0.9). More patients preferred their second course (P < 0.0001), and were significantly less anxious (P = 0.0002). Patients reported tolerating their treatment similarly for both antiemetics, but more patients preferred prochlorperazine (P = 0.003), mainly due to reductions in nausea and vomiting and other side-effects, particularly diarrhoea.

Adult↗
PubMed1994

The influence of induction chemotherapy dose and dose intensity on the duration of remission in acute myeloid leukemia. Australian Leukemia Study Group.

The aim of this study was to assess the influence of dose and dose intensity (DI) of induction and consolidation chemotherapy on relapse rates in 264 de novo patients with acute nonlymphocytic leukemia (ANLL). Patients were randomised to receive cytosine arabinoside (ARAC) 100 mg/m2 continuous infusion for 7 days and daunorubicin (DNR) 50 mg/m2 IV day 1-3 (7-3) or the same drugs with the addition of etoposide 75 mg/m2 IV days 1-7 (7-3-7). Cox proportional hazards regression models were used throughout to identify prognostic factors, including dose delivery parameters, influencing the rate of relapse. Of 152 patients who achieved a complete remission (CR), 104 have relapsed with a median duration of CR of 15.8 months. Actual dose delivered was prospectively documented. Cox regression analysis identified the most significant prognostic factors jointly influencing duration of CR as performance status groups (p < 0.0001), percentage peripheral blasts (p = 0.0015), 7-3-7 arm (p = 0.0075), age < 40 years (p = 0.022) and induction dose ARA-C plus DNR (p = 0.029). In this analysis patients randomized to the 7-3-7 arm had an estimated 43% reduction in the relapse rate and each 10% reduction of doses ARA-C and DNR was associated with an estimated 45% increase in the relapse rate. The number of induction courses, delays in treatment and induction dose intensity did not significantly influence the duration of CR nor did any of the consolidation treatment parameters.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

The incidence and prognostic significance of mutations in codon 13 of the N-ras gene in acute myeloid leukemia.

To determine the incidence and prognostic significance of mutation in the N-ras gene in de novo acute myeloid leukemia (AML) we performed an analysis of bone marrow smears from 219 patients with de novo AML treated between 1984 and 1986 and followed for at least six years. DNA extracted from bone marrow smears taken at diagnosis was screened for the presence of mutations in codons 12 and 13 of exon 1 by using the polymerase chain reaction to insert an Hph1 restriction enzyme site into DNA. Presumptive mutations were confirmed by direct sequencing. Mutations were detected in a total of 26 patients (12%); in nine patients (4%) in codon 12 only, in ten patients (5%) in codon 13 only, and in seven patients (3%) in both codons. Mutations in codon 12 or codon 13 were not associated with any clinical features. Mutations in codon 12 had no prognostic significance but mutations in codon 13 were associated with an increased remission rate, a more durable remission, and a significantly prolonged survival which appeared to be independent of other prognostic factors.

Base Sequence↗
PubMed1994

Radiation and carboplatin combined-modality therapy in non-small cell lung cancer.

Previously untreated patients with stages I to IV, N0-3, M0 unresectable non-small cell lung cancer were randomized to arm I (conventional radiotherapy [RT], 60 Gy in 30 fractions over 6 weeks), arm II (accelerated RT, 60 Gy in 30 fractions over 3 weeks), arm III (conventional RT, as in arm I, plus carboplatin 70 mg/m2/d on days 1 to 5 during treatment weeks 1 and 5), or arm IV (accelerated RT, as in arm II, plus carboplatin 70 mg/m2/d on days 1 to 5 of week 1 only). An intensive analysis of toxicity in the first 92 patients entered revealed significantly more neutropenia (P < .0001) and thrombocytopenia (P = .004) in the combined-modality arms. Esophagitis was worse on arms II, III, and IV, but was more prolonged in the accelerated RT arms. Overall, however, the treatment on all study arms was well tolerated.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

Effect of toremifene on antipyrine elimination in the isolated perfused rat liver.

Toremifene is a triphenylethylene antioestrogen with significant antitumor activity. It is structurally very similar to tamoxifen. Both drugs undergo extensive hepatic metabolism, and tamoxifen is known to inhibit hepatic mixed-function oxidases (MFO). Using the isolated perfused rat-liver model, we investigated the effect of toremifene on the elimination of antipyrine, a standard marker of MFO activity. Perfusate consisted of 20% red cells in a modified Krebs-Henseleit buffer, and 80 ml was recirculated at 14 ml/min for 3 h. High but clinically relevant steady-state toremifene levels of 3 and 10 micrograms/ml were achieved using bolus plus constant infusion into the reservoir. Elimination of 2.5 mg antipyrine was not inhibited by steady-state toremifene, but methanol (maximal perfusate concentration, 1.29%), the vehicle used for toremifene administration, caused a statistically significant increase in the antipyrine elimination half-life (mean, 1.4 +/- 0.2 h for controls vs 2.2 +/- 0.3 h for methanol; P < 0.05, n = 4). Whereas the methanol had no apparent effect on liver viability as assessed by bile flow and perfusate back-pressure, toremifene at a steady-state concentration of 10 micrograms/ml caused a statistically significant decrease in bile flow (value at 180 min, 0.22 +/- 0.05 ml/h as compared with 0.52 +/- 0.06 ml/h in the methanol control; P < 0.05) and a statistically significant increase in perfusate back-pressure (value at 180 min, 17.5 +/- 1.8 cm vs 11.0 +/- 2.6 cm in the methanol control; P < 0.05). Therefore, toremifene used at high doses can impair liver function in the isolated perfused rat liver, but it does not have any effect on antipyrine elimination.

Animals↗