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Biomedical subjects

P Burt

Publications and source records attributed to P Burt.

14 recordsLinked to original sources
PubMed2005

Randomized phase II study of two gemcitabine schedules for patients with impaired performance status (Karnofsky performance status </= 70) and advanced non-small-cell lung cancer.

PURPOSE: This randomized phase II study compared two treatment schedules of gemcitabine in patients with non-small-cell lung cancer (NSCLC) and impaired Karnofsky performance status (KP). Primary objectives were to record changes from baseline KP and to assess symptom palliation. Secondary objectives were overall survival, tumor response, and toxicity. PATIENTS AND METHODS: Patients with stage IIIb and IV NSCLC and KP </= 70 were randomly assigned to receive gemcitabine 1,000 mg/m(2) on days 1, 8, and 15 of each 28-day cycle (3w4) or gemcitabine 1,500 mg/m(2) on days 1 and 8 of each 21-day cycle (2w3), both for up to six cycles. KP, toxicity, and SS14 lung cancer specific questions were recorded before each cycle of treatment. Response was evaluated 4 weeks after the last cycle. RESULTS: One hundred seventy-four patients were enrolled. There was significant early attrition due to disease progression; only 61.5% of patients were alive at 2 months. There was a significant improvement in KP from baseline to pre-cycle 3 in both arms, with a trend in favor of the 3w4 regimen for duration and faster onset of improvement. Eight of the 17 quality-of-life (QOL) variables assessed showed an improvement of more than 10% between baseline and the start of the third cycle of treatment. Response rate, survival, and duration were similar in both arms. CONCLUSION: There was no significant difference between the two schedules examined in terms of improvement in KP or QOL, but there seemed to be a trend in favor of the 3w4 schedule.

Adult↗
PubMed2000

Clinical and quality of life outcomes in the first United Kingdom randomized trial of endobronchial brachytherapy (intraluminal radiotherapy) vs. external beam radiotherapy in the palliative treatment of inoperable non-small cell lung cancer.

BACKGROUND AND PURPOSE: A randomized controlled trial was designed to evaluate the clinical and quality of life (QL) outcomes of patients receiving endobronchial brachytherapy (EBT) or external beam radiotherapy (XRT) as a primary palliative treatment in advanced lung cancer. MATERIALS AND METHODS: Ninety-nine patients presenting de novo with lung cancer were randomized to receive EBT or XRT. Eleven key symptoms or clinical signs were assessed by clinicians and patient ratings using self-assessment questionnaires were obtained at the same time. The primary endpoints were a comparison of EBT and XRT for symptom relief and acute and late side-effects (palliation) and their effect on patients' functional status and patient-rated QL outcomes. A secondary objective was a comparison of clinician assessments with patient self-reported symptoms. RESULTS: Both treatments produced good levels of symptom relief. They were better for XRT at the expense of more acute morbidity. Late side-effects were similar. The functional status of patients was well maintained and changed similarly with time in both groups. XRT gave a better duration of palliation. Twenty-eight percent of XRT patients required EBT (at a median time of 304 days) whereas 51% of EBT patients subsequently had XRT (at a median of 125 days). There was a significant modest gain in median survival with initial XRT (287 vs. 250 days). When clinician and patient assessments were compared, doctors were found to underestimate the severity of breathlessness, anorexia, tiredness and nausea. CONCLUSIONS: Fractionated XRT is preferred to EBT as an initial treatment in better performance patients because it provides better overall and more sustained palliation with fewer retreatments and a modest gain in survival time. QL assessment is required in the evaluation of palliative treatments because clinicians frequently underestimate the incidence and severity of key symptoms.

Adult↗
PubMed1998

Dose intensity in small cell lung cancer.

Evidence from preclinical models and from clinical trials describing the importance of dose intensity in securing a better treatment outcome is reviewed. Recent randomized trials have shown statistically significant survival benefits with higher-dose, accelerated chemotherapy regimens with and without granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor. The novel use of peripheral blood progenitor cells contained in whole blood autotransfusions, which allow a marked increase in dose intensity of an ifosfamide/carboplatin/etoposide regimen, could provide a much easier method of delivering dose-intensive chemotherapy than previously available.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

The Value of Anatomic Staging and Other Prognostic Factors in Small Cell Lung Cancer Management: A View of European Studies.

The need to include simple laboratory indices and performance status evaluation in treatment decision making has been shown by multivariate analyses. The conventional limited-stage extensive-stage division of prognostic groups no longer provides sufficient information. Indeed, some patients in the limited-stage group have a poor prognosis and about one quarter of patients in the extensive-stage group have a better prognosis when information from performance status and pretreatment biochemistry is taken into account. There is no rational clinical need for elaborate staging procedures, eg, computed tomography scanning or bone marrow examination, in the majority of patients with small cell lung cancer. Adequate information for defining prognostic groups can be obtained by using performance status, lactate dehydrogenase, and other biochemical tests such as sodium, alkaline phosphatase, and albumin. Thereby the cost to the patient of unnecessary burdensome investigations and to health care could both be reduced.

Journal Article↗
PubMed1994

Therapy for small cell lung cancer using carboplatin, ifosfamide, etoposide (without dose reduction), mid-cycle vincristine with thoracic and cranial irradiation.

The aim of this study was to assess the efficacy and toxicity of intensive chemotherapy, administered without dose reduction, with cranial and thoracic radiotherapy given when possible as a single fraction in small cell lung cancer. 87 patients were eligible on the basis of good performance status, normal or near normal biochemistry and clinical staging, 73 limited and 14 extensive stage, computed tomography scanning was not mandatory. Six cycles of carboplatin, ifosfamide and etoposide with vincristine on day 15 at 4 weekly intervals were planned. Dosages were not reduced in response to myelosuppression. Prophylactic cranial irradiation (PCI) as a single fraction after the first cycle and thoracic irradiation (when possible as a single fraction) following the third cycle were delivered. Seventy-two per cent of patients completed the protocol. Complete response rate was 55% and 26% of patients had a partial response. The median nadirs of neutropenia were 0.5 x 10(9)/l and thrombocytopenia 14 x 10(9)/l, with 6% probable treatment-related deaths. Performance status and dyspnoea improved markedly to normal or near normal levels following the second course. Brain metastases occurred in 13% of patients. The median survival was 16.2 months with a 2-year survival of 31% (95% confidence interval, 24-41%) for a minimum follow-up of 26 months. These results compare favourably with other combined modality studies, using multiple radiotherapy fractions with cisplatin-based combinations and dosage reduction for patients staged in more anatomical detail. The toxicity spectrum and efficacy data could lead to the use of this chemotherapy regimen with haematopoietic growth factors and, in the future, peripheral blood progenitor cell rescue.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Neurological and cognitive impairment in long-term survivors of small cell lung cancer.

Despite its effectiveness in reducing the rate of brain metastases, the role of prophylactic cranial irradiation (PCI) in the management of small cell lung cancer (SCLC) remains controversial because of concern about radiation-induced neurological morbidity. In order to evaluate morbidity and its impact on quality of life 64 patients surviving > or = 2 years in remission were recalled for assessment. 52 had received PCI. Most of the patients were well: 95% had performance status < or = 1 and nine out of 37 neurological examinations were abnormal. On neuropsychometric testing, only 19% of patients performed at the level expected for their age and intellectual ability on all four tests used. Fifty-four per cent of patients were impaired on two or more of the tests, suggesting a significant degree of measurable cognitive dysfunction. The number of patients who had not received PCI was insufficient for comparative analysis with the number who had, but among those treated with PCI, patients receiving 8 Gy in 1 fraction appeared less impaired than those receiving higher radiation doses in multiple fractions. The study showed that neuropsychometric testing is acceptable to patients, can be administered by non-psychologists in the clinic and is sensitive to otherwise undetected deficits of cognitive function in this patient population. Prospective evaluation of PCI should include neuropsychometric testing.

Adult↗
PubMed1994

Propofol and seizures.

It is now clear that "seizure activity", excitatory phenomena, and/or a disorder of muscle tone are potential complications of the use of propofol. Whether this "seizure activity" is primarily, secondarily, or not at all a cerebral cortical event is still to be elucidated. Clearly propofol does have anticonvulsant activity, and also clearly it can produce an involuntary movement disorder, in certain patients, under certain conditions. Propofol is not the first anaesthetic drug to be implicated in the causation of seizures or abnormal movements nor indeed the first to appear to have anti-convulsant and proconvulsant activity (e.g. Althesin). While propofol has undoubtedly proved a very useful drug, the problem of convulsive phenomena creates a degree of background concern about its use. More needs to be known about the mechanism of this complication and any risk factors involved in determining who may have a seizure after propofol. In the clinical setting, the reporting of seizures possibly related to propofol should include--medical history, including personal or family history of epilepsy and movement disorders; a history of previous anaesthetics and whether propofol was used; regular medications; use of drugs or alcohol; history of chemical dependency; emotional state prior to induction; presence of hyperventilation or fever; a description of the alleged seizure, including rate of administration of propofol and amount given, time of onset of seizure in relation to time of drug administration, speed of onset of signs, quality of the abnormal movements, part of body involved, duration, any indication of a postictal state, any cardiovascular changes which may have accompanied the seizure, and any other possible triggers for the reaction such as other drugs used, including premedication; post seizure investigations including temperature, blood sugar, electrolytes, arterial gas analysis, neurological examination, EEG and CT scan. These actions and these investigations concerning propofol should not be delayed. It would appear appropriate to recommend to patients who experience apparent convulsive phenomena after propofol that they not be re-exposed to the drug.

Adult↗
PubMed1994

Intensive combined-modality therapy in small cell lung cancer.

Combination ifosfamide/carboplatin/etoposide (ICE) chemotherapy and ICE plus mid-cycle vincristine (VICE) are reviewed. Thoracic radiotherapy and prophylactic cranial irradiation given as single fractions in the majority of patients have been intercalated with VICE in the later studies. The patient populations have not been intensively staged with computed tomography, etc, but do have reasonable Karnofsky performance status ratings and biochemical screens. A policy of no dose reduction over six courses of VICE chemotherapy has been followed in three consecutive studies of 166 patients. The minimum length of follow-up is 26 months and the 2-year survival rate is > or = 30%. Hematopoietic growth factor support in an attempt to overcome the considerable myelosuppression with VICE therapy is currently being evaluated.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Intensive therapy for small-cell lung cancer using carboplatin alternating with cisplatin, ifosfamide, etoposide, mid-cycle vincristine, and radiotherapy.

Forty patients with small-cell lung cancer (31 patients with limited-stage [LS] disease, and nine patients with extensive-stage [ES] disease but of good performance status) have been treated with an intensive therapy composed of carboplatin alternating with cisplatin, ifosfamide, and etoposide with vincristine on day 14 of each carboplatin cycle. A maximum of six cycles were administered at 3 weekly intervals after the cisplatin combination and 4 weekly after the carboplatin combination. Prophylactic cranial irradiation was given with the first cycle of chemotherapy and thoracic irradiation with the third cycle. The median nadir for neutrophils was 0.47 x 10(9)/L and for platelets, 40 x 10(9)/L. Chemotherapy dosages were not reduced in response to myelosuppression, but treatment was delayed to allow blood count recovery. Sixty-eight percent of patients received all six cycles of chemotherapy, and there were four deaths associated with treatment-related neutropenia. Twenty-eight patients (70%) achieved a complete response (CR) when assessed 1 month after the end of treatment, and a further five patients (12.5%) had a partial response (PR). Median duration of CR was 16 months and of PR, 8 months. Cerebral metastases occurred in 20% of all patients and was the apparent sole site of relapse in 11% of the CR patients. The median survival of the total group was 14 months with an actual 2-year survival of 30% and a minimum follow-up of 28 months.

Adult↗
PubMed1990

Weight loss and change in resting metabolic rate.

The relation between change in resting metabolic rate (RMR) and change in fat-free mass (FFM) after weight loss is not well understood and is often inappropriately expressed in kilocalories per unit of FFM. We measured RMR and FFM in 35 obese patients enrolled in a conservative weight-loss program. RMR per kilogram FFM was not different after weight loss. However, the regression of delta RMR on delta FFM revealed that the decline in RMR tended to be greater than could be accounted for by loss of FFM. At initial test and retest, body fat (Fat) was not a predictor of RMR after FFM had been taken into account but delta Fat significantly contributed to the prediction of delta RMR when added to the equation after delta FFM. Thus, people losing larger amounts of weight had declines in RMR greater than could be accounted for by loss of FFM. Self-reported age of onset of obesity was not related to delta RMR.

Adipose Tissue↗
PubMed1980

A disparity gradient limit for binocular fusion.

Ever since Panum, it has been commonly assumed that there is an absolute disparity limit for binocular fusion. It is now found that nearby objects modify this disparity limit. This result sheds new light on several enigmatic phenomena in stereopsis.

Form Perception↗
PubMed1980

Modifications of the classical notion of Panum's fusional area.

It is generally believed that there is an absolute disparity limit for binocular fusion; objects with disparities within this limit, known as Panum's fusional area, will appear fused and single, while objects with disparities outside the limit appear double. It is demonstrated, however, that the disparity gradient, rather than the disparity magnitude, dictates binocular fusion when several objects occur near one another in the visual field. The disparity gradient is defined as the difference between the disparities of neighboring objects divided by their angular separation. If this ratio exceeds a critical value (approximately 1) then fusion does not occur, even though the absolute disparities of the individual objects may be well within the classical Panum's area. This discovery leads to the reinterpretation of several enigmatic phenomena in stereopsis, including Panum's limiting case.

Humans↗