1,893 research outputs found
Bronchoscopic radioisotope injection for sentinel lymph-node mapping in potentially resectable non-small-cell lung cancer
Objective: Prospective study to evaluate the feasibility of a preoperative bronchoscopic radioisotope application, followed by conventional sentinel lymph-node (SLN) identification and to investigate the occurrence and distribution of micrometastases in relation to SLN activity. Methods: Twenty patients with a mean age of 63 years and proven clinical stage T1-3 N0-1 non-small-cell lung cancer (NSCLC) were included. A dosage of 80 MBq radiolabeled technetium-99m nanocolloid was endoscopically administrated on intubated patients in the operation theatre. At thoracotomy, scintigraphic readings of both the primary tumor and hilar and mediastinal lymph-node stations were obtained with a hand-held gamma-counter. Patients underwent lung resection and mediastinal lymphadenectomy. Radiolabeled nodes were also examined separately on back-table. SLNs were defined as the hottest nodes or nodes with at least one-tenth of the radioactivity of the hottest nodes. SLNs pathologic assessment included standard examination using hematoxylin and eosin staining on step sections and immunohistochemistry (ICH) for cytokeratins. Results: Identification of SLNs was possible in 19/20 (95%) patients after bronchoscopic radioisotope application. In 7/19 (37%) patients, a unique SLN was identified, whereas in 12/19 (63%) patients, nodes from two different stations could be classified as SLNs. Metastatic nodal disease was found in 9/19 (47%) patients. ICH revealed micrometastases in 2/12 (17%) patients, initially classified nodal negative. Pathologic negative SLNs were a predictor for absence of metastatic nodal disease after mediastinal lymphadenectomy. No complication related to the procedure was observed. Conclusion: Our preliminary results suggest that preoperative bronchoscopic radioisotope injection for SLN identification is a safe and simple method, improving accuracy of SLN detection in comparison to intraoperative technique. The absence of metastases in the SLNs seems to predict a negative nodal status accuratel
Monitoring Ion Channel Function In Real Time Through Quantum Decoherence
In drug discovery research there is a clear and urgent need for non-invasive
detection of cell membrane ion channel operation with wide-field capability.
Existing techniques are generally invasive, require specialized nano
structures, or are only applicable to certain ion channel species. We show that
quantum nanotechnology has enormous potential to provide a novel solution to
this problem. The nitrogen-vacancy (NV) centre in nano-diamond is currently of
great interest as a novel single atom quantum probe for nanoscale processes.
However, until now, beyond the use of diamond nanocrystals as fluorescence
markers, nothing was known about the quantum behaviour of a NV probe in the
complex room temperature extra-cellular environment. For the first time we
explore in detail the quantum dynamics of a NV probe in proximity to the ion
channel, lipid bilayer and surrounding aqueous environment. Our theoretical
results indicate that real-time detection of ion channel operation at
millisecond resolution is possible by directly monitoring the quantum
decoherence of the NV probe. With the potential to scan and scale-up to an
array-based system this conclusion may have wide ranging implications for
nanoscale biology and drug discovery.Comment: 7 pages, 6 figure
The Second International Conference on Sentinel Node Biopsy in Mucosal Head and Neck Cancer
Background: The Second International Conference on Sentinel Node Biopsy in Mucosal Head and Neck Cancer was hosted by the Department of Otorhinolaryngology, Head and Neck Surgery of the University Hospital in Zurich, Switzerland, from September 12 to 13, 2003. The aims of this conference were to present the results of validation studies and to achieve a consensus on methodological requirements. Methods: More than 80 delegates from 20 countries attended the conference. The presented validation studies were summarized and compared with the literature. Consensus was achieved concerning requirements for lymphatic mapping and histopathologic work-up. Results: Twenty centers presented results on 379 patients with cN0 disease. Sentinel nodes were identified in 366 (97%) of 379. Of these 366, 103 (29%) were positive for occult metastasis, and 263 (71%) were negative. Of those 263 patients, 11 patients (4%) showed nodal disease not revealed by the sentinel lymph node biopsy (SNB). The negative predictive value of a negative sentinel node for the remaining neck was 96%. The consensus conference resulted in the use of a radiotracer, lymphoscintigraphy, and a handheld gamma probe for lymphatic mapping as minimal requirements. The use of conventional hematoxylin and eosin staining and immunohistochemistry for cytokeratin is mandatory. Step-sectioning of the entire node at intervals of 150μm is recommended. Conclusions: The conference attracted delegates from all over the world, thus underscoring the high interest in the topic. With regard to the presented data and the data from the literature, SNB for early oral and oropharyngeal cancer is sufficiently validated. The consensus conference resulted in the definition of minimal methodological requirements for accurate SN
Do saving promotion interventions help alleviate poverty in Sub-Saharan Africa? A systematic review and meta-analysis
Saving promotion interventions have gained momentum in international development over the recent years. Our analysis investigates whether saving promotion can effectively reduce poverty and economic hardship in Sub-Saharan Africa. In an extensive database search, 9330 records were screened and 27 randomised controlled trials on saving promotion interventions fulfilled the inclusion criteria. Robust-variance estimations of pooled effect sizes show small but significant impacts on poverty reduction, including increases in household expenditures and incomes, higher returns from family businesses, and improved food security. They also show positive impacts on more intermediate outcomes including total savings, pro-saving attitudes, financial literacy, and investments in small-scale family businesses. Our results do not show significant effects on assets, housing quality, education, or health. Findings from this analysis suggest that saving promotion schemes are highly relevant in reducing poverty in Sub-Saharan Africa, and that formal banking services in particular require adaptation to the needs of the poor
Research Directions in Network Service Chaining
Network Service Chaining (NSC) is a service deployment concept that promises increased flexibility and cost efficiency for future carrier networks. NSC has received considerable attention in the standardization and research communities lately. However, NSC is largely undefined in the peer-reviewed literature. In fact, a literature review reveals that the role of NSC enabling technologies is up for discussion, and so are the key research challenges lying ahead. This paper addresses these topics by motivating our research interest towards advanced dynamic NSC and detailing the main aspects to be considered in the context of carrier-grade telecommunication networks. We present design considerations and system requirements alongside use cases that illustrate the advantages of adopting NSC. We detail prominent research challenges during the typical lifecycle of a network service chain in an operational telecommunications network, including service chain description, programming, deployment, and debugging, and summarize our security considerations. We conclude this paper with an outlook on future work in this are
Limited value of 18F-FDG PET/CT and S-100B tumour marker in the detection of liver metastases from uveal melanoma compared to liver metastases from cutaneous melanoma
Purpose: The objective of this study was to evaluate the value of 18F-FDG PET/CT and S-100B tumour marker for the detection of liver metastases from uveal melanoma in comparison to liver metastases from cutaneous melanoma. Methods: A retrospective evaluation was conducted of 27 liver metastases in 13 patients with uveal melanoma (UM) (mean age: 56.8, range: 30-77) and 43 liver metastases in 14 patients (mean age: 57.9, range: 40-82) with cutaneous melanoma (CM) regarding size and FDG uptake by measuring the maximum standardized uptake value (SUVmax). S-100B serum tumour markers were available in 20 patients. Cytology, histology, additional morphological imaging and follow-up served as reference standard. In nine patients liver metastases were further evaluated histologically regarding GLUT-1 and S-100 receptor expression and regarding epithelial or spindle cell growth pattern. Results: Of 27 liver metastases in 6 of 13 patients (46%) with UM, 16 (59%) were FDG negative, whereas all liver metastases from CM were positive. Liver metastases from UM showed significantly (p < 0.001) lower SUVmax (mean: 3.5, range: 1.5-13.4) compared with liver metastases from CM (mean: 6.6, range: 2.3-15.3). In four of six (66.7%) patients with UM and liver metastases S-100B was normal and in two (33.3%) increased. All PET-negative liver metastases were detectable by morphological imaging (CT or MRI). S-100B was abnormal in 13 of 14 patients with liver metastases from CM. S-100B values were significantly higher (p = 0.007) in the CM patient group (mean S-100B: 10.9μg/l, range: 0.1-115μg/l) compared with the UM patients (mean: 0.2μg/l, range: 0.0-0.5μg/l). Histological work-up of the liver metastases showed no obvious difference in GLUT-1 or S-100 expression between UM and CM liver metastases. The minority (36%) of patients with UM had extrahepatic metastases and the majority (86%) of patients with CM had extrahepatic metastases, respectively. There was a close to significant trend to better survival of UM patients compared with CM patients (p = 0.06). Conclusion: FDG PET/CT and serum S-100B are not sensitive enough for the detection of liver metastases from UM, whereas liver metastases from cutaneous melanoma are reliably FDG positive and lead regularly to increased S-100B tumour markers. The reason for the lower FDG uptake in UM liver metastases remains unclear. We recommend to perform combined contrast-enhanced PET/CT in order to detect FDG-negative liver metastases from U
The influence of postgraduate qualifications on educational identity formation of healthcare professionals
Demand for postgraduate qualifications in medical education can be judged by the increase in providers worldwide over the last two decades. However, research into the impact of such courses on identity formation of healthcare professionals is limited. This study investigates the influence of such programmes on graduates’ educational identities, practices and career progression. Informed by constructivist grounded theory (CGT), semi-structured interviews were conducted with 27 graduates (2008–2012) from one postgraduate programme, who were at different stages in their careers worldwide. The audio data were transcribed and analysed using a CGT approach. Participants enrolled in award-bearing medical education courses for various intrinsic and extrinsic reasons. The findings from this study highlight their development as educators, and educational researchers, leaders and learners, as their self-efficacy in educational practices and engagement in scholarly activities increased. Graduates attributed career progression to the qualification, with many being promoted into senior positions. They also described substantial performance attainments in the workplace. The findings contribute to understanding the complexity and nuances of educational identity formation of healthcare professionals. A qualification in medical education encouraged transformational changes and epistemological development as an educator. Awareness of these findings will inform both those considering enrolment and those supporting them of potential benefits of these programmes
Search for gravitational waves associated with the InterPlanetary Network short gamma ray bursts
We outline the scientific motivation behind a search for gravitational waves
associated with short gamma ray bursts detected by the InterPlanetary Network
(IPN) during LIGO's fifth science run and Virgo's first science run. The IPN
localisation of short gamma ray bursts is limited to extended error boxes of
different shapes and sizes and a search on these error boxes poses a series of
challenges for data analysis. We will discuss these challenges and outline the
methods to optimise the search over these error boxes.Comment: Methods paper; Proceedings for Eduardo Amaldi 9 Conference on
Gravitational Waves, July 2011, Cardiff, U
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