The use of pharmacokinetic and pharmacodynamic end points to determine the dose of AQ4N, a novel hypoxic cell cytotoxin, given with fractionated radiotherapy in a phase I study

BACKGROUND

AQ4N (1,4-bis[[2-(dimethylamino)ethyl] amino]-5,8-dihydroxyanthracene-9, 10-dione bis-N-oxide dihydrochloride) is a prodrug which is selectively activated within hypoxic tissues to AQ4, a topoisomerase II inhibitor and DNA intercalator.

PATIENTS AND METHODS

In the phase I study, 22 patients with oesophageal carcinoma received an i.v. infusion of AQ4N (22.5-447 mg/m(2)) followed, 2 weeks later, by further infusion and radiotherapy. Pharmacokinetics and lymphocyte AQ4N and AQ4 levels were measured after the first dose. At 447 mg/m(2), biopsies of tumour and normal tissue were taken after AQ4N administration.

RESULTS

Drug-related adverse events were blue discolouration of skin and urine, grade 2-3 lymphopenia, grade 1-3 fatigue, grade 1-2 anaemia, leucopenia and nausea. There were no drug-related serious adverse events (SAEs). Three patients had reductions in tumour volume >50%, nine had stable disease. Pharmacokinetics indicated predictable clearance. Plasma area under the curve (AUC) at 447 mg/m(2) exceeded AQ4N concentrations in mice at therapeutic doses and tumour biopsies contained concentrations of AQ4 greater than those in normal tissue. Tumour concentrations of AQ4 exceeded in vitro IC(50) values for most cell lines investigated.

CONCLUSIONS

No dose-limiting toxic effects were observed and a maximum tolerated dose was not established. Tumour AQ4 concentrations and plasma AUC at 447 mg/m(2) exceeded active levels in preclinical models. This dose was chosen for future studies with radiotherapy.

A multicentre longitudinal observational study of changes in self reported health status in people with Parkinson's disease left untreated at diagnosis

BACKGROUND

The issue of when to start treatment in Parkinson's disease (PD) remains controversial. Some favour treatment at diagnosis while others opt for a "wait and watch" policy. The effect of the latter policy on the self reported health status of people with PD is unknown.

AIMS

To record self reported health status through longitudinal use of a validated PD specific questionnaire (PDQ-39) in untreated PD patients in multiple centres in the UK. To compare patients who were left untreated with those who were offered treatment during follow-up.

METHODS

A multicentre, prospective, "real life" observational audit based study addressing patient reported outcomes in relation to self reported health status and other sociodemographic details.

RESULTS

198 untreated PD were assessed over a mean period of 18 months. During two follow-up assessments, the self reported health status scores in all eight domains of the PDQ-39 and the overall PDQ-39 summary index worsened significantly (p<0.01) in patients left untreated. In a comparative group in whom treatment was initiated at or soon after diagnosis, there was a trend towards improvement in self reported health status scores after treatment was started.

CONCLUSIONS

This study addresses for the first time self reported health status, an indicator of health related quality of life, in untreated PD. The findings may strengthen the call for re-evaluation of the policy to delay treatment in newly diagnosed patients with PD.

An improved resolution structure of the human beta common receptor involved in IL-3, IL-5 and GM-CSF signalling which gives better definition of the high-affinity binding epitope

X-ray diffraction has been used to produce and refine a model of the extracellular domains of the beta common cytokine receptor. A minor improvement in resolution has resulted in improved electron-density maps, which have given a clearer indication of the position and stabilization of the key residues Tyr15, Phe79, Tyr347, His349, Ile350 and Tyr403 in the elbow region between domain 1 and domain 4 of the dimer-related molecule.

Whole body MR imaging: Applications in oncology

This article reviews technique and clinical applications of whole body MR imaging as a diagnostic tool in cancer staging. In particular the article reviews its role as an alternative to scintigraphy (bone scan and PET) in staging skeletal spread of disease, its role in assessing total tumour burden, its role in multiple myeloma and finally its evolving non oncologic role predominantly assessing total body composition.

Ethics of evidence based medicine in the primary care setting

Evidence based medicine has had an increasing impact on primary care over the last few years. In the UK it has influenced the development of guidelines and quality standards for clinical practice and the allocation of resources for drug treatments and other interventions. It has informed the thinking around patient involvement in decision making with the concept of evidence based patient choice. There are, however, concerns among primary care clinicians that evidence based medicine is not always relevant to primary care and that undue emphasis placed on it can lead to conflict with a clinician's duty of care and respect for patient autonomy. In this paper we consider the impact of evidence based medicine on primary care, and the ethical implications of its increasing prominence for clinicians and managers in primary care.

Clinical Trials Update: CAPRICORN, COPERNICUS, MIRACLE, STAF, RITZ-2, RECOVER and RENAISSANCE and cachexia and cholesterol in heart failure. Highlights of the Scientific Sessions of the American College of Cardiology, 2001

This is a synopsis of presentations made at the American College of Cardiology (ACC) in 2001 summarising recent research developments relating to heart failure. Clinical studies of particular interest to physicians with an interest in heart failure and its prevention are reviewed. The COPERNICUS trial lends further support to the use of the beta-blocker, carvedilol, in severe heart failure and the CAPRICORN trial to its use in patients with post-infarction left ventricular systolic dysfunction. The MIRACLE study reinforces the evidence from three smaller trials that cardiac resynchronisation therapy is an effective treatment for the relief of symptoms in patients with severe heart failure and cardiac dyssynchrony. The STAF trial casts further doubt on the wisdom of cardioversion as a routine strategy for the management of chronic atrial fibrillation. The RITZ-2 trial suggests that an intravenous, non-selective endothelin antagonist is effective in improving haemodynamics and symptoms and possibly in reducing morbidity in severe heart failure. Observational studies in heart failure suggest that a moderate excess of body fat and elevated blood cholesterol may be desirable in patients with heart failure, challenging the current non-evidenced-based vogue for cholesterol lowering therapy in heart failure. The RENAISSANCE and RECOVER outcome studies of etanercept, a tumour necrosis factor (TNF) receptor analogue that blocks the effect of TNF, were stopped because of lack of evidence of benefit shortly after the ACC.

Diabetes knowledge--are patients getting the message?

Diabetes knowledge in a multi-ethnic population was assessed in 161 insulin treated diabetic patients using a 21-point multiple choice questionnaire translated into the appropriate languages. Our data showed a significant difference in diabetes knowledge related to ethnicity, being less in Asians and Afro-Caribbeans groups compared to Caucasians. In all groups there was a negative correlation with age, with older adults achieving lower scores. Gender and duration of disease did not appear to influence knowledge scores. This information has implications for the way in which we deliver our diabetes educational programme to ethnic minority groups and the elderly.

The Medical Interaction Process System (MIPS): an instrument for analysing interviews of oncologists and patients with cancer

The increase in communication skills training for doctors has led to the need for more effective means of evaluation. Analysis of video and audiotaped consultations using systems of interaction analysis can provide the trainee with in-depth feedback about their communication skills. Most interaction process systems were designed for use in primary care and recent research has questioned the applicability of these systems in medical specialties such as oncology. We describe the development of a new instrument, the Medical Interaction Process System (MIPS) for use in teaching communication skills and empirical research in medical encounters, particularly, between doctors and patients with cancer. A comparison of the MIPS and comparable behaviour categories of another widely used system (the Roter Interaction Analysis System) was made to test convergent validity. Pearson correlation coefficients suggested a good level of concurrence between the two systems. Intercoder reliability tests were carried out between two coders at two separate time periods. Both of these indicated good reliability for the majority of categories. The two major advantages of the MIPS over other coding systems are: (1) the system allows for sequential and parallel coding, thus avoiding major coding conflicts and (2) the design of the coding sheet results in a multidimensional view of the consultation without data loss. We believe that the MIPS yields useful information for teaching doctors communication skills and also provides an objective method for evaluating the effectiveness of communication skills courses.

Thyroid adenocarcinoma in a bald eagle (Haliaeetus leukocephalus)

Thyroid adenocarcinoma was diagnosed in an adult bald eagle (Haliaeetus leukocephalus) with clinical signs of weakness manifested by inability to fly. Physical examination at the time of admission revealed dried blood in the pharynx and glottis and the presence of pharyngeal trichomonads. Radiographs revealed a large soft tissue mass in the area of the left coracoid and clavicular bones. One month following successful treatment for trichomoniasis, the bird suffered an acute episode of tracheal hemorrhage and died. Necropsy revealed a large mass within the interclavicular air sac. The histologic features were consistent with thyroid adenocarcinoma. This is the first report of thyroid neoplasia in a member of the order Falconiformes.

Relationship between histamine and physiological changes during the early response to nasal antigen provocation

To investigate the temporal relationships of mediator release and physiological changes during the early response to allergen, we challenged allergic individuals intranasally with antigen and followed their responses. This was done by using small filter paper disks to challenge one nostril and collect secretions from both the challenged and the contralateral nostril, thus enabling us to evaluate the nasonasal reflex. There was a significant increase in sneezing after allergen challenge that peaked within 2 min and returned to baseline. The weights of nasal secretions as well as nasal symptoms increased immediately and remained significantly elevated for 20 min in both nostrils. Nasal airway resistance increased slowly, reaching its peak at approximately 6 min after challenge on the ipsilateral side, but it did not change on the contralateral side. Histamine levels peaked 30 s after removal of the allergen disk on the side of challenge, whereas albumin levels peaked after those of histamine. Lactoferrin paralleled the increase in secretion weights and occurred in both nostrils. Increasing doses of antigen produced dose-dependent increases in all parameters, whereas control challenges produced no response. These studies describe a human model for the evaluation of the allergic response that is capable of simultaneously measuring mediator release and the physiological response, including the nasonasal reflex. This model should prove useful in studying the mechanism of allergic rhinitis in humans.