277 research outputs found
Pretreatment Effects on the Uptake/Retention Kinetics of L-Dopa in Harding-Passey Melanoma
Malignant melanoma cells possess a unique biochemical pathway that converts L-3,4-dihydroxyphenylalanine (L-dopa) to the biopigment melanin. Selective cytotoxic incorporation of exogenous L-dopa into melanoma cells in vivo may provide a means of designing specific chemotherapeutic agents useful in the treatment of this disease. Using the Harding-Passey murine melanotic tumor model, a preferential uptake of [3H]L-dopa by the tumor was characterized. Following pretreatment of the tumor-bearing mice with nonradioactive L-dopa, a significant enhancement (p < 0.01) of [3H]L-dopa incorporation and retention into melanoma for a period of 24h was observed, when compared with the concomitant tissue distribution and clearance of radioactivity in the control animals. This finding suggests that by initial pretreatment of melanoma with nonradioactive L-dopa, the subsequent selective accumulation of [3H]L-dopa in tumor may provide a useful tool in testing new modalities of therapy in malignant melanoma
Organizational Mortality of Small Firms: The Effects of Entrepreneurial Age and Human Capital
This paper addresses the issue of internal determination of organizational outcomes. It is argued that in small and simply structured organizations a considerable proportion of the variance in organizational activities and outcomes is associated with individuals. In particular, the paper uses human capital theory to derive hypotheses about individual determinants of organizational mortality. These hypotheses are tested with event-history data of firm registrations and de-registrations in a West German region. The hypotheses are corroborated by the data, but the effects may nonetheless be due to processes linking individual characteristics with organizational performance other than those suggested by the human capital approach
'Caught Between a Rock and a Hard Place': Anti-discrimination Legislation in the Liberal State and the Fate of the Australian Disability Discrimination Act
This article offers a critical analysis of some of the practical implications for disabled people of the Disability Discrimination Act of 1992. Specifically, it raises questions about politics and the role of the law as an instrument of social change?taking greater account of the interests of disabled people?on the one hand, and of the reliance of the social model of disability on a strategy based upon legal rights on the other. The article also suggests that the constraining effects of Australia's constitutional protections of rights and its federal system of government hinder the mildly progressive elements of the Disability Discrimination Act. To illustrate this, the paper employs empirical evidence to suggest that these effects have been exacerbated by the passage of the Human Rights Legislation Amendment Act in 1999
Epidural Hematoma Following Cervical Spine Surgery.
STUDY DESIGN: A multicentered retrospective case series.
OBJECTIVE: To determine the incidence and circumstances surrounding the development of a symptomatic postoperative epidural hematoma in the cervical spine.
METHODS: Patients who underwent cervical spine surgery between January 1, 2005, and December 31, 2011, at 23 institutions were reviewed, and all patients who developed an epidural hematoma were identified.
RESULTS: A total of 16 582 cervical spine surgeries were identified, and 15 patients developed a postoperative epidural hematoma, for a total incidence of 0.090%. Substantial variation between institutions was noted, with 11 sites reporting no epidural hematomas, and 1 site reporting an incidence of 0.76%. All patients initially presented with a neurologic deficit. Nine patients had complete resolution of the neurologic deficit after hematoma evacuation; however 2 of the 3 patients (66%) who had a delay in the diagnosis of the epidural hematoma had residual neurologic deficits compared to only 4 of the 12 patients (33%) who had no delay in the diagnosis or treatment (P = .53). Additionally, the patients who experienced a postoperative epidural hematoma did not experience any significant improvement in health-related quality-of-life metrics as a result of the index procedure at final follow-up evaluation.
CONCLUSION: This is the largest series to date to analyze the incidence of an epidural hematoma following cervical spine surgery, and this study suggest that an epidural hematoma occurs in approximately 1 out of 1000 cervical spine surgeries. Prompt diagnosis and treatment may improve the chance of making a complete neurologic recovery, but patients who develop this complication do not show improvements in the health-related quality-of-life measurements
Broad phenotypic spectrum in familial adenomatous polyposis; from early onset and severe phenotypes to late onset of attenuated polyposis with the first manifestation at age 72
<p>Abstract</p> <p>Background</p> <p>Familial adenomatous polyposis (FAP) is typically characterized by multiple colonic polyps and frequent extracolonic features. Whereas the number of colonic polyps has been linked to the <it>APC </it>gene mutation, possible genotype-phenotype correlations largely remain to be defined for the extracolonic manifestations.</p> <p>Methods</p> <p>Full genomic sequencing combined with multiplex ligation-dependent probe amplification was used to identify <it>APC </it>gene mutations, which were correlated to the clinical presentations.</p> <p>Results</p> <p>10 novel <it>APC </it>gene mutations were identified in 11 families. A broad spectrum of extracolonic manifestations was identified in most of these individuals. Two sisters with an insertion in codon 528 (c.1582_1583insGC) both showed severe phenotypes with classical polyposis, upper gastrointestinal polyps and thyroid cancer. A woman with a 3'<it>APC </it>mutation (c.5030_5031insAA) developed colon cancer at age 72 as the first manifestation of attenuated FAP.</p> <p>Conclusion</p> <p>With an increasing number of FAP families diagnosed, a broad and variable tumor spectrum and a high frequency of extracolonic manifestations are gradually recognized. We report novel <it>APC </it>mutations and present two FAP cases that suggest familial aggregation of thyroid cancer and demonstrate the need to consider attenuated FAP also among elderly patients with colon cancer.</p
Behavioural activation by mental health nurses for late-life depression in primary care: a randomized controlled trial
Background: Depressive symptoms are common in older adults. The effectiveness of pharmacological treatments and the availability of psychological treatments in primary care are limited. A behavioural approach to depression treatment might be beneficial to many older adults but such care is still largely unavailable. Behavioural Activation (BA) protocols are less complicated and more easy to train than other psychological therapies, making them very suitable for delivery by less specialised therapists. The recent introduction of the mental health nurse in primary care centres in the Netherlands has created major opportunities for improving the accessibility of psychological treatments for late-life depression in primary care. BA may thus address the needs of older patients while improving treatment outcome and lowering costs.The primary objective of this study is to compare the effectiveness and cost-effectiveness of BA in comparison with treatment as usual (TAU) for late-life depression in Dutch primary care. A secondary goal is to explore several potential mechanisms of change, as well as predictors and moderators of treatment outcome of BA for late-life depression.
Methods/design: Cluster-randomised controlled multicentre trial with two parallel groups: a) behavioural activation, and b) treatment as usual, conducted in primary care centres with a follow-up of 52 weeks. The main inclusion criterion is a PHQ-9 score > 9. Patients are excluded from the trial in case of severe mental illness that requires specialized treatment, high suicide risk, drug and/or alcohol abuse, prior psychotherapy, change in dosage or type of prescribed antidepressants in the previous 12 weeks, or moderate to severe cognitive impairment. The intervention consists of 8 weekly 30-min BA sessions delivered by a trained mental health nurse.
Discussion: We expect BA to be an effective and cost-effective treatment for late-life depression compared to TAU. BA delivered by mental health nurses could increase the availability and accessibility of non-pharmacological treatments for late-life depression in primary care.
Trial registration: This study is retrospectively registered in the Dutch Clinical Trial Register NTR6013on August 25th 2016.
© 2017 The Author(s)
Use of homework by mental health case managers in the rehabilitation of persistent and recurring psychiatric disability
The case for strategic international alliances to harness nutritional genomics for public and personal health
Nutrigenomics is the study of how constituents of the diet interact with genes, and their products, to alter phenotype and, conversely, how genes and their products metabolise these constituents into nutrients, antinutrients, and bioactive compounds. Results from molecular and genetic epidemiological studies indicate that dietary unbalance can alter gene-nutrient interactions in ways that increase the risk of developing chronic disease. The interplay of human genetic variation and environmental factors will make identifying causative genes and nutrients a formidable, but not intractable, challenge. We provide specific recommendations for how to best meet this challenge and discuss the need for new methodologies and the use of comprehensive analyses of nutrient-genotype interactions involving large and diverse populations. The objective of the present paper is to stimulate discourse and collaboration among nutrigenomic researchers and stakeholders, a process that will lead to an increase in global health and wellness by reducing health disparities in developed and developing countrie
An in vitro method of alcoholic liver injury using precision-cut liver slices from rats
MedPerf : Open Benchmarking Platform for Medical Artificial Intelligence using Federated Evaluation
Medical AI has tremendous potential to advance healthcare by supporting the evidence-based practice of medicine, personalizing patient treatment, reducing costs, and improving provider and patient experience. We argue that unlocking this potential requires a systematic way to measure the performance of medical AI models on large-scale heterogeneous data. To meet this need, we are building MedPerf, an open framework for benchmarking machine learning in the medical domain. MedPerf will enable federated evaluation in which models are securely distributed to different facilities for evaluation, thereby empowering healthcare organizations to assess and verify the performance of AI models in an efficient and human-supervised process, while prioritizing privacy. We describe the current challenges healthcare and AI communities face, the need for an open platform, the design philosophy of MedPerf, its current implementation status, and our roadmap. We call for researchers and organizations to join us in creating the MedPerf open benchmarking platform
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