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We report a method for characterizing the focussing laser beam exiting the objective in a laser scanning microscope. This method provides the size of the optical focus, the divergence of the beam, the ellipticity and the astigmatism. We use a microscopic-scale knife edge in the form of a simple transmission electron microscopy grid attached to a glass microscope slide, and a light-collecting optical fibre and photodiode underneath the specimen. By scanning the laser spot from a reflective to a transmitting part of the grid, a beam profile in the form of an error function can be obtained and by repeating this with the knife edge at different axial positions relative to the beam waist, the divergence and astigmatism of the postobjective laser beam can be obtained. The measured divergence can be used to quantify how much of the full numerical aperture of the lens is used in practice. We present data of the beam radius, beam divergence, ellipticity and astigmatism obtained with low (0.15, 0.7) and high (1.3) numerical aperture lenses and lasers commonly used in confocal and multiphoton laser scanning microscopy. Our knife-edge method has several advantages over alternative knife-edge methods used in microscopy including that the knife edge is easy to prepare, that the beam can be characterized also directly under a cover slip, as necessary to reduce spherical aberrations for objectives designed to be used with a cover slip, and it is suitable for use with commercial laser scanning microscopes where access to the laser beam can be limited. [ABSTRACT FROM AUTHOR]

Evaluates the effect of surgery plus tamoxifen and tamoxifen alone on women aged over 70 years with operable breast cancer. Treatment failure of women taking tamoxifen alone; Hazard ratio; Increase in overall mortality among breast cancer patients taking tamoxifen alone.

Background: Evidence for improved exercise tolerance or relief of breathlessness by short term use of oxygen before or after exercise in patients with chronic obstructive pulmonary disease (COPD) is scant, and guidelines for this treatment are lacking despite widespread provision in the UK.Methods: The effect of oxygenation either before or after exercise on perception of breathlessness and walk distance was studied in a group of patients with moderate to severe COPD (mean forced expiratory volume in 1 second (FEV(1)) 34% of predicted, mean 6 minute walk distance on air 283 m), all of whom desaturated by at least 4% on submaximal exercise. Oxygen (28%) or air was delivered double blind and in random order, either for 5 minutes before a standard 6 minute walk test (n=34) or for 5 minutes following the end of the test (n=18). Exercise tolerance was measured as the distance achieved and breathlessness was assessed using visual analogue scales (VAS) which were scored before and after exercise and during recovery.Results: No increase in mean walk distance after oxygen (288 v 283 m) and no improvement in mean breathlessness scores (58 v 54 mm) or recovery times occurred with oxygen taken either before (177 v 184 seconds) or after exercise (182 v 151 seconds).Conclusions: This group of patients with COPD derived no physiological or symptomatic benefit from oxygen breathed for short periods before or after submaximal exercise. Domiciliary oxygen should only be prescribed for such patients if they have shown objective evidence of benefit on exercise testing. [ABSTRACT FROM AUTHOR]

Objectives Financial stress has been identified as a barrier to antiretroviral adherence, but only in resource- limited settings. Almost half of HIV-infected Australian adults earn no regular income and, despite highly subsidised antiretroviral therapy and universal health care, 3% of HIV-infected Australians cease antiretroviral therapy each year. We studied the relationship between financial stress and treatment adherence in a resource-rich setting. Methods Out-patients attending the HIV clinic at St Vincent's Hospital between November 2010 and May 2011 were invited to complete an anonymous survey including questions relating to costs and adherence. Results Of 335 HIV-infected patients (95.8% male; mean age 52 years; hepatitis coinfection 9.2%), 65 patients (19.6%) stated that it was difficult or very difficult to meet pharmacy dispensing costs, 49 (14.6%) reported that they had delayed purchasing medication because of pharmacy costs, and 30 (9.0%) reported that they had ceased medication because of pharmacy costs. Of the 65 patients with difficulties meeting pharmacy costs, 19 (29.2%) had ceased medication vs. 11 (4.1%) of the remaining 270 patients ( P < 0.0001). In addition, 19 patients (5.7%) also stated that it was difficult or very difficult to meet travel costs to the clinic. Treatment cessation and interruption were both independently associated with difficulty meeting both pharmacy and clinic travel costs. Only 4.9% had been asked if they were having difficulty paying for medication. Conclusions These are the first data to show that pharmacy dispensing and clinic travel costs may affect treatment adherence in a resource-rich setting. Patients should be asked if financial stress is limiting their treatment adherence. [ABSTRACT FROM AUTHOR]

This study, involving a cohort of 1284 evaluable patients, validates the American Joint Committee on Cancer (AJCC) proposal for the introduction of ulceration of primary cutaneous melanoma as an independent prognostic factor of survival. In univariate analyses, ulceration (Hazard Ratio (HR) 1.983; P<0.0001; 95% Confidence Intervals (CI) 1.692–2.325) was a predictor of worse overall survival. In multivariate analyses, ulceration (HR 1.302; P=0.022; (95% CI: 1.039–1.633) retained its prognostic significance for survival independent of tumour thickness (HR 1.101; P<0.0001; 95% CI: 1.055–1.150); mitotic activity (HR 1.039; P=0.005; 95% CI: 1.012–1.067); and age (HR 1.009; P=0.006; 95% CI: 1.003–1.016). Ulceration lost its significance in a subgroup analysis of 256 patients with clinically apparent regional lymph node metastases to the number of lymph nodes involved (HR 1.15; P=0.004; 95% CI:1.047–1.263). Ulceration is prognostically significant in the tumour but not the nodal classification of melanoma, with mitotic activity the second most important prognostic factor after tumour thickness. [Copyright &y& Elsevier]

Focuses on medical-related issues in Great Britain. Effectiveness of hyperbaric oxygen in multiple sclerosis; Desensitization of patients developing urticaria or asthma; Role of immunological deficiency in cancer occurring in organ transplant recipients.

Presents a letter to the editor about rates of gonorrhoea and chlamydia in black ethnic groups.

Aims: Breast cancer has been considered a more indolent disease in the elderly compared to younger women. The aim of this trial was to test the hypothesis that tamoxifen alone would provide adequate control of breast cancer over the normal expectation of life of an elderly woman, thereby sparing them surgery. Methods: Patients with operable invasive breast cancer aged over 70 were randomized to either tamoxifen alone, 40 mg daily, or surgery plus the same dose of tamoxifen. As the tumour was still in situ in half the patients, the first change of management (COM) was taken to signal primary treatment failure in place of recurrence-free interval. Overall and breast cancer mortality was compared in the two groups. Results: Between 1984 and 1992, 455 patients with operable disease were randomized into the trial. This analysis is based on a median follow-up of 12.3 years. The COM-free interval was significantly shorter in the tamoxifen-alone group (hazard ratio (HR) = 2.80 (95 per cent confidence interval (CI) = 2.09–3.74)) as was the progression-free interval (HR = 4.42(95 per centCI = 3.33–5.87)). For surgery-plus-tamoxifen patients the most frequent intervention was hormonal therapy (51 per cent) whereas for tamoxifen-alone patients it was surgery (64 per cent). The greater hazard ratio for progression-free interval compared to COM-free interval is due to a delay in changing management once patients in the tamoxifen-alone group had evidence of progression. Overall mortality and mortality from breast cancer were significantly increased in the tamoxifen-alone group compared to the surgery-plus-tamoxifen group, HR = 1.3 (95 per cent CI = 1.05–1.61) and HR = 1.75 (95 per cent CI = 1.18–2.59), respectively. Stratification of overall mortality by age and tumour size suggested that patients aged 70–72 or with T3 tumours had an increased mortality when treated with tamoxifen alone compared to surgery-plus-tamoxifen, HR = 2.00 (... [ABSTRACT FROM AUTHOR]