Changes in practice of breast cancer radiotherapy 1998–2002: An Australasian survey

In order to assess the impact on radiation oncology practice of the publication of evidence-based guidelines for technical aspects of therapeutic radiation for breast cancer, the Radiation Oncology Expert Advisory Group of the National Breast Cancer Centre conducted two postal surveys of radiation oncologists practising in Australia and New Zealand. Results from a survey conducted in 1998, prior to distribution of the guidelines, have been published previously. This article reports on results from a survey undertaken in 2002 and contains data from 102 respondents who manage women with breast cancer. The results show several important changes in practice since 1998, including increased use of CT scanning in breast cancer treatment planning and increased use of immobilization devices for patient treatment. There is also evidence of increased attention to technical aspects of treatment planning that reduce the potential risk of treatment toxicity. The influence of the guidelines, the wider availability of modern equipment and results from landmark clinical trials on change in radiation therapy practice is discussed.     

What is Essential Tremor?

Classic essential tremor is a clinical syndrome of action tremor in the upper limbs (at least 95 % of patients) and less commonly the head, face/jaw, voice, tongue, trunk, and lower limbs, in the absence of other neurologic signs. However, the longstanding notion that essential tremor is a monosymptomatic tremor disorder is being challenged by a growing literature describing associated disturbances of tandem walking, personality, mood, hearing, and cognition. There is also epidemiologic, pathologic, and genetic evidence that essential tremor is pathophysiologically heterogeneous. Misdiagnosis of essential tremor is common because clinicians frequently overlook other neurologic signs and because action tremor in the hands is caused by many conditions, including dystonia, Parkinson disease, and drug-induced tremor. Thus, essential tremor is nothing more than a syndrome of idiopathic tremulousness, and the challenge for researchers and clinicians is to find specific etiologies of this syndrome.     

Magnetic resonance thermometry of flowing blood

Blood temperature is a key determinant of tissue temperature and can be altered under normal physiological states, such as exercise, in diseases such as stroke or iatrogenically in therapies which modulate tissue temperature, such as therapeutic hypothermia. Currently available methods for the measurement of arterial and venous temperatures are invasive and, for small animal models, are impractical. Here, we present a methodology for the measurement of intravascular and tissue temperature by magnetic resonance imaging (MRI) using the lanthanide agent TmDOTMA^? (DOTMA, tetramethyl‐1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetraacetic acid; Tm, thulium). The approach makes use of phase‐sensitive imaging measurements, combined with spectrally selective excitation, to monitor the temperature‐dependent shift in the resonance of proton nuclei associated with water and with methyl groups of TmDOTMA^?. Measurements were first made in a flow phantom modelling diastolic blood flow in the mouse aorta or inferior vena cava (IVC) and imaged using 7‐T preclinical MRI with a custom‐built surface coil. Flowing and static fluid temperatures agreed to within 0.12°C for these experiments. Proof‐of‐concept experiments were also performed on three healthy adult mice, demonstrating temperature measurements in the aorta, IVC and kidney following a bolus injection of contrast agent. A small (0.7–1°C), but statistically significant, higher kidney temperature compared with the aorta (p  = 0.002–0.007) and IVC (p  = 0.003–0.03) was shown in all animals. These findings demonstrate the feasibility of the technique for in vivo applications and illustrate how the technique could be used to explore the relationship between blood and tissue temperature for a wide range of applications.     

Immunoglobulin-like domain containing receptor 1 mediates fat-stimulated cholecystokinin secretion

Cholecystokinin (CCK) is a satiety hormone produced by discrete enteroendocrine cells scattered among absorptive cells of the small intestine. CCK is released into blood following a meal; however, the mechanisms inducing hormone secretion are largely unknown. Ingested fat is the major stimulant of CCK secretion. We recently identified a novel member of the lipoprotein remnant receptor family known as immunoglobulin-like domain containing receptor 1 (ILDR1) in intestinal CCK cells and postulated that this receptor conveyed the signal for fat-stimulated CCK secretion. In the intestine, ILDR1 is expressed exclusively in CCK cells. Orogastric administration of fatty acids elevated blood levels of CCK in wild-type mice but not Ildr1-deficient mice, although the CCK secretory response to trypsin inhibitor was retained. The uptake of fluorescently labeled lipoproteins in ILDR1-transfected CHO cells and release of CCK from isolated intestinal cells required a unique combination of fatty acid plus HDL. CCK secretion secondary to ILDR1 activation was associated with increased [Ca²⁺]_i, consistent with regulated hormone release. These findings demonstrate that ILDR1 regulates CCK release through a mechanism dependent on fatty acids and lipoproteins and that absorbed fatty acids regulate gastrointestinal hormone secretion.     

Vilanterol trifenatate,a novel inhaled long-acting beta2 adrenoceptor agonist,is well tolerated in healthy subjects and demonstrates prolonged bronchodilation in subjects with asthma and COPD

Vilanterol (VI; GW642444M) is a novel inhaled long-acting β2-agonist with inherent 24 h activity in vitro in development as a combination with the inhaled corticosteroid fluticasone furoate for both COPD and asthma. These studies were conducted to determine the safety, tolerability, pharmacodynamics and pharmacokinetics of VI in healthy subjects and subjects with mild to moderate persistent asthma and moderate to severe COPD.Single doses of VI (25–100 μg) were given once daily to subjects with asthma and COPD and repeat doses once daily for 14 days to healthy subjects. Adverse events (AEs), vital signs, ECGs, pharmacodynamic endpoints, FEV₁ and VI plasma pharmacokinetics (AUC, Cmax and Tmax) were determined following dosing.VI (25–100 μg) was well tolerated. The incidence and severity of AEs were comparable to placebo. Following VI administration there were no clinically significant abnormalities in vital signs, 12-lead ECG, Holter ECG, blood glucose or potassium. There were no statistically significant effects on QTc of single and repeat VI doses up to 50 μg; some differences were seen following the 100 μg VI dose after single and repeat dose in healthy subjects and single dose in asthmatic subjects. All VI doses produced increases in FEV₁ from as early as 5 min after dosing which were maintained up to 24 h post-dose in subjects with asthma and COPD. In all subjects VI was rapidly absorbed (healthy subjects median Tmax at 5 min; asthma and COPD subjects median Tmax at 10 min) with systemic exposure increasing in an approximately dose proportional manner across the VI dose range. Marginal accumulation was seen on repeat dosing.Single doses of inhaled VI in subjects with asthma and COPD and repeat doses in healthy subjects were well tolerated with no clinically significant unwanted systemic effects. VI produced a rapid and prolonged bronchodilation over 24 h suggesting the potential for once daily administration.