Self-pulsation at 480 GHz from a two-color discrete mode laser diode

A discrete mode Fabry-Pérot laser is designed and fabricated to achieve two-color lasing. We demonstrate beating between the two laser modes and self-pulsation at 480 GHz

Inverse scattering approach to multiwavelength Fabry-Pérot laser design

A class of multiwavelength Fabry-Pérot lasers is introduced where the spectrum is tailored through a patterning of the cavity effective index. The cavity geometry is obtained using an inverse scattering approach and can be designed such that the spacing of discrete Fabry-Pérot lasing modes is limited only by the bandwidth of the inverted gain medium. A specific two-color semiconductor laser with a mode spacing in the THz region is designed, and measurements are presented demonstrating the simultaneous oscillation of the two wavelengths. The nonperiodic effective index profile of the particular two-color device considered is shown to be related to a Moiré or superstructure grating

Anorexia nervosa and Wernicke-Korsakoff syndrome: a case report

<p>Abstract</p> <p>Introduction</p> <p>Wernicke's encephalopathy is an acute, potentially fatal, neuropsychiatric syndrome resulting from thiamine deficiency. The disorder is still greatly under-diagnosed, and failure to promptly identify and adequately treat the condition can lead to death or to the chronic form of the encephalopathy - Korsakoff's syndrome. Wernicke's encephalopathy has traditionally been associated with alcoholism but, in recent years, there has been an increase in the number of clinical settings in which the disorder is observed.</p> <p>Case presentation</p> <p>We report the case of a 45-year-old Caucasian woman who arrived at the emergency room presenting signs of marked malnutrition and mental confusion, ataxic gait and ophthalmoplegia. Main laboratory test findings included low serum magnesium and megaloblastic anemia. Brain magnetic resonance imaging revealed increased T2 signal in the supratentorial paraventricular region, the medial regions of the thalamus and the central and periaqueductal midbrain. The diagnosis of Wernicke's encephalopathy was made at once and immediate reposition of thiamine and magnesium was started. The patient had a long history of recurrent thoughts of being overweight, severe self-imposed diet restrictions and self-induced vomiting. She had also been drinking gin on a daily basis for the last eight years. One day after admittance the acute global confusional state resolved, but she presented severe memory deficits and confabulation. After six months of outpatient follow-up, memory deficits remained unaltered.</p> <p>Conclusion</p> <p>In this case, self-imposed long-lasting nutritional deprivation is thought to be the main cause of thiamine deficiency and subsequent encephalopathy, but adjunct factors, such as magnesium depletion and chronic alcohol misuse, might have played an important role, especially in the development of Korsakoff's syndrome. The co-morbidity between eating disorders and substance abuse disorders has emerged as a significant health issue for women, and the subgroup of patients with anorexia nervosa who also misuse alcohol is probably at a particular risk of developing Wernicke-Korsakoff syndrome. The present case report highlights this relevant issue.</p

Malignant spinal cord compression: a retrospective audit of clinical practice at a UK regional cancer centre

Malignant Spinal Cord Compression (MSCC) is a particularly challenging area of cancer care where early diagnosis and expert multiprofessional care and rehabilitation, are paramount in optimising quality of life. This audit reports data collected retrospectively over a period of 12 months on patients with MSCC referred to the West of Scotland Cancer Centre (n=174). It was carried out to build on the work of the Clinical Resource and Audit Group (CRAG) and to examine current practice for symptom assessment, multiprofessional care and rehabilitation of patients with MSCC admitted to the cancer centre. Areas of concern include poor assessment of pain, the poor ambulatory status of patients on admission and the lack of clear plans for mobilisation and rehabilitation for the majority of patients. Recommendations include the development of regional guidelines for referral, treatment and rehabilitation, and the development of a pathway of care for use in all care settings across the region, together with improvements for use in patient information, staff education, audit and research. These are now being taken forward through the West of Scotland Cancer Network with dedicated funding from Macmillan Cancer Relief

Prognostic scores in brain metastases from breast cancer

<p>Abstract</p> <p>Background</p> <p>Prognostic scores might be useful tools both in clinical practice and clinical trials, where they can be used as stratification parameter. The available scores for patients with brain metastases have never been tested specifically in patients with primary breast cancer. It is therefore unknown which score is most appropriate for these patients.</p> <p>Methods</p> <p>Five previously published prognostic scores were evaluated in a group of 83 patients with brain metastases from breast cancer. All patients had been treated with whole-brain radiotherapy with or without radiosurgery or surgical resection. In addition, it was tested whether the parameters that form the basis of these scores actually have a prognostic impact in this biologically distinct group of brain metastases patients.</p> <p>Results</p> <p>The scores that performed best were the recursive partitioning analysis (RPA) classes and the score index for radiosurgery (SIR). However, disagreement between the parameters that form the basis of these scores and those that determine survival in the present group of patients and many reported data from the literature on brain metastases from breast cancer was found. With the four statistically significant prognostic factors identified here, a 3-tiered score can be created that performs slightly better than RPA and SIR. In addition, a 4-tiered score is also possible, which performs better than the three previous 4-tiered scores, incl. graded prognostic assessment (GPA) score and basic score for brain metastases (BSBM).</p> <p>Conclusion</p> <p>A variety of prognostic models describe the survival of patients with brain metastases from breast cancer to a more or less satisfactory degree. However, the standard brain metastases scores might not fully appreciate the unique biology and time course of this disease, e.g., compared to lung cancer. It appears possible that inclusion of emerging prognostic factors will improve the results and allow for development and validation of a consensus score for broad clinical application. The model that is based on the authors own patient group, which is not large enough to fully evaluate a large number of potential prognostic factors, is meant to illustrate this point rather than to provide the definitive score.</p

Whole brain radiotherapy with radiosensitizer for brain metastases

<p>Abstract</p> <p>Purpose</p> <p>To study the efficacy of whole brain radiotherapy (WBRT) with radiosensitizer in comparison with WBRT alone for patients with brain metastases in terms of overall survival, disease progression, response to treatment and adverse effects of treatment.</p> <p>Methods</p> <p>A meta-analysis of randomized controlled trials (RCT) was performed in order to compare WBRT with radiosensitizer for brain metastases and WBRT alone. The MEDLINE, EMBASE, LILACS, and Cochrane Library databases, in addition to Trial registers, bibliographic databases, and recent issues of relevant journals were researched. Significant reports were reviewed by two reviewers independently.</p> <p>Results</p> <p>A total of 8 RCTs, yielding 2317 patients were analyzed. Pooled results from this 8 RCTs of WBRT with radiosensitizer have not shown a meaningful improvement on overall survival compared to WBRT alone OR = 1.03 (95% CI0.84–1.25, p = 0.77). Also, there was no difference in local brain tumor response OR = 0.8(95% CI 0.5 – 1.03) and brain tumor progression (OR = 1.11, 95% CI 0.9 – 1.3) when the two arms were compared.</p> <p>Conclusion</p> <p>Our data show that WBRT with the following radiosentizers (ionidamine, metronidazole, misonodazole, motexafin gadolinium, BUdr, efaproxiral, thalidomide), have not improved significatively the overall survival, local control and tumor response compared to WBRT alone for brain metastases. However, 2 of them, motexafin- gadolinium and efaproxiral have been shown in recent publications (lung and breast) to have positive action in lung and breast carcinoma brain metastases in association with WBRT.</p