419 research outputs found

    VHL Type 2B gene mutation moderates HIF dosage in vitro and in vivo

    Get PDF
    Von Hippel-Lindau (VHL) disease is caused by germline mutations in the VHL tumor suppressor gene, with Type 2B missense VHL mutations predisposing to renal cell carcinoma, hemangioblastoma, and pheochromocytoma. Type 2B mutant pVHL is predicted to be defective in hypoxia inducible factor (HIF)-α regulation. Murine embryonic stem (ES) cells in which the endogenous wild-type Vhl gene was replaced with the representative Type 2B VHL hotspot mutation R167Q (Vhl2B/2B) displayed preserved physiologic regulation of both HIF factors with slightly more normoxic dysregulation of HIF-2α. Differentiated Vhl2B/2B-derived teratomas over-expressed the joint HIF targets Vegf and EglN3 but not the HIF-1α-specific target Pfk1 and displayed a growth advantage over Vhl-/--derived teratomas, suggestive of a tight connection between perturbations in the degree and ratio of HIF-1α and HIF-2α stabilization and cell growth. Vhl2B/2B mice displayed mid-gestational embryonic lethality, while adult Vhl2B/+ mice exhibited susceptibility to carcinogen-promoted renal neoplasia compared with wild-type littermates at twelve months. Our experiments support a model in which the representative Type 2B R167Q mutant pVhl produces a unique profile of HIF dysregulation, thereby promoting tissue-specific effects on cell growth, development, and tumor predisposition

    Recovery of visual fields in brain-lesioned patients by reaction perimetry treatment

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The efficacy of treatment in hemianopic patients to restore missing vision is controversial. So far, successful techniques require laborious stimulus presentation or restrict improvements to selected visual field areas. Due to the large number of brain-damaged patients suffering from visual field defects, there is a need for an efficient automated treatment of the total visual field.</p> <p>Methods</p> <p>A customized treatment was developed for the reaction perimeter, permitting a time-saving adaptive-stimulus presentation under conditions of maximum attention. Twenty hemianopic patients, without visual neglect, were treated twice weekly for an average of 8.2 months starting 24.2 months after the insult. Each treatment session averaged 45 min in duration.</p> <p>Results</p> <p>In 17 out of 20 patients a significant and stable increase of the visual field size (average 11.3° ± 8.1) was observed as well as improvement of the detection rate in the defective visual field (average 18.6% ± 13.5). A two-factor cluster analysis demonstrated that binocular treatment was in general more effective in augmenting the visual detection rate than monocular. Four out of five patients with a visual field increase larger than 10° suffered from hemorrhage, whereas all seven patients with an increase of 5° or less suffered from infarction. Most patients reported that visual field restoration correlated with improvement of visual-related activities of daily living.</p> <p>Conclusion</p> <p>Rehabilitation treatment with the Lubeck Reaction Perimeter is a new and efficient method to restore part of the visual field in hemianopia. Since successful transfer of treatment effects to the occluded eye is achieved under monocular treatment conditions, it is hypothesized that the damaged visual cortex itself is the structure in which recovery takes place.</p

    Adjuvant nivolumab for stage III/IV melanoma: Evaluation of safety outcomes and association with recurrence-free survival

    Get PDF
    Background Several therapeutic options are now available in the adjuvant melanoma setting, mandating an understanding of their benefit €'risk profiles in order to make informed treatment decisions. Herein we characterize adjuvant nivolumab select (immune-related) treatment-related adverse events (TRAEs) and evaluate possible associations between safety and recurrence-free survival (RFS) in the phase III CheckMate 238 trial. Methods Patients with resected stage IIIB-C or IV melanoma received nivolumab 3 mg/kg every 2 weeks (n=452) or ipilimumab 10 mg/kg every 3 weeks for four doses and then every 12 weeks (n=453) for up to 1 year or until disease recurrence, unacceptable toxicity, or consent withdrawal. First-occurrence and all-occurrence select TRAEs were analyzed within discrete time intervals: from 0 to 3 months of treatment, from &gt;3-12 months of treatment, and from the last dose (regardless of early or per-protocol treatment discontinuation) to 100 days after the last dose. Possible associations between select TRAEs and RFS were investigated post randomization in 3-month landmark analyses and in Cox model analyses (including a time-varying covariate of select TRAE), within and between treatment groups. Results From the first nivolumab dose to 100 days after the last dose, first-occurrence select TRAEs were reported in 67.7% (306/452) of patients. First-occurrence select TRAEs were reported most frequently from 0 to 3 months (48.0%), during which the most common were pruritus (15.5%) and diarrhea (15.3%). Most select TRAEs resolved within 6 months. There was no clear association between the occurrence (or not) of select TRAEs and RFS by landmark analysis or by Cox model analysis within treatment arms or comparing nivolumab to the ipilimumab comparator arm. Conclusion Results of this safety analysis of nivolumab in adjuvant melanoma were consistent with its established safety profile. In the discrete time intervals evaluated, most first-occurrence TRAEs occurred early during treatment and resolved. No association between RFS and select TRAEs was evident. Trial registration number NCT02388906

    Adjuvant nivolumab versus ipilimumab (CheckMate 238 trial): Reassessment of 4-year efficacy outcomes in patients with stage III melanoma per AJCC-8 staging criteria

    Get PDF
    Nivolumab was approved as adjuvant therapy for melanoma based on data from CheckMate 238, which enrolled patients per American Joint Committee on Cancer version 7 (AJCC-7) criteria. Here, we analyse long-term outcomes per AJCC-8 staging criteria&nbsp;compared with AJCC-7 results to inform clinical decisions for patients diagnosed per AJCC-8

    The key challenges of discussing end-of life stroke care with patients and families: a mixed-methods electronic survey of hospital and community healthcare professionals

    Get PDF
    Background: Communication between professionals, patients and families about palliative and end-of-life care after stroke is complex and there is a need for educational resources in this area. Methods: To explore the key learning needs of healthcare professionals, a multidisciplinary, expert group developed a short electronic survey with open and closed questions, and then distributed it to six UK multiprofessional networks and two groups of local clinicians. Results: A total of 599 healthcare professionals responded. Educational topics that were either definitely or probably needed were: ensuring consistent messages to families and patients (88%); resolving conflicts among family members (83%); handling unrealistic expectations (88%); involving families in discussions without them feeling responsible for decisions (82%); discussion of prognostic uncertainties (79%); likely mode of death (72%); and oral feeding for 'comfort' in patients at risk of aspiration (71%). The free-text responses (n = 489) and 82 'memorable' cases identified similar themes. Conclusion: Key topics of unmet need for education in end-of-life care in stroke have been identified and these have influenced the content of an open access, web-based educational resource

    Challenges and Opportunities in Finfish Nutrition

    Get PDF
    Much of the criticism leveled at aquaculture (e.g., dependency on animal-derived feedstuffs, nutrient-laden effluent discharges, and increased organic contamination in edible products) can be traced to the feeds in use. Accordingly, finfish nutritionists are being challenged to formulate feeds that not only meet the nutritional requirements of livestock but also minimize production costs, limit environmental impacts, and enhance product quality. These challenges not only add considerable complexity to finfish nutrition but also afford opportunities to avoid some of the mistakes made by other industries in the past. From a review of the current status of finfish nutrition with respect to major nutrient classes, we comment on future opportunities and promising avenues of research. Alternative protein sources, specifically those derived from marine bycatch, plants, and microbes, are discussed, as well as methods to facilitate their implementation in finfish feeds. Dietary lipid, its role in fish bioenergetics and physiology, and quality of aquaculture products is reviewed with special emphasis on alternative lipid sources and finishing diets. Carbohydrates and fiber are discussed in terms of nutrient-sparing, least-cost diet formulation and digestive physiology. Micronutrients are reviewed in terms of current knowledge of requirements and, along with other dietary immunostimulants, are given further consideration in a review of nutriceuticals and application in finfish feeds. The status of nutritional research in new aquaculture species is also outlined. By integrating classical approaches with emerging technologies, dietary formulations, and species, finfish nutritionists may identify means to increase production efficiency and sustainability and provide for the continued success of aquaculture

    Fatty acid metabolism in marine fish: Low activity of fatty acyl Δ5 desaturation in gilthead sea bream ( Sparus aurata ) cells

    Get PDF
    Marine fish are known to have an absolute dietary requirement for C20 and C22 highly unsaturated fatty acids. Previous studies using cultured cell lines indicated that underlying this requirement in marine fish was either a deficiency in fatty acyl Δ5 desaturase or C18-20 elongase activity. Recently, Ghioni et al. (Biochim. Biophys. Acta, 1437, 170-181, 1999) presented evidence that in turbot cells there was low activity of C18-20 elongase whereas Δ5 desaturase had high activity. In the present study, the fatty acid desaturase/elongase pathway was investigated in a cell line (SAF-1) from another carnivorous marine fish, sea bream. The metabolic conversions of a range of radiolabelled polyunsaturated fatty acids that comprised the direct substrates for Δ6 desaturase ([1-14C]18:2n-6 and [1-14C]18:3n-3), C18-20 elongase ([U-14C]18:4n-3), Δ5 desaturase ([1-14C]20:3n-6 and [U-14C]20:4n-3) and C20-22 elongase ([1-14C]20:4n-6 and [1-14C]20:5n-3) were utilized. The results showed that fatty acyl Δ6 desaturase in SAF-1 cells was highly active and there was substantial C18-20 elongase and C20-22 elongase activities. A deficiency in the desaturation/elongation pathway was clearly identified at the level of the fatty acyl Δ5 desaturase which was very low, particularly with 20:4n-3 as substrate. In comparison, the apparent activities of Δ6 desaturase, C18-20 elongase and C20-22 elongase were approximately 94-fold, 27-fold and 16-fold greater than that for Δ5 desaturase towards their respective n-3 polyunsaturated fatty acid substrates. The evidence obtained in the SAF-1 cell line is consistent with the dietary requirement for C20 and C22 highly unsaturated fatty acids in the marine fish, the sea bream, being primarily due to a deficiency in fatty acid Δ5 desaturase activity
    corecore