398 research outputs found

    Extensive spontaneous plasticity of corticospinal projections after primate spinal cord injury.

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    Although axonal regeneration after CNS injury is limited, partial injury is frequently accompanied by extensive functional recovery. To investigate mechanisms underlying spontaneous recovery after incomplete spinal cord injury, we administered C7 spinal cord hemisections to adult rhesus monkeys and analyzed behavioral, electrophysiological and anatomical adaptations. We found marked spontaneous plasticity of corticospinal projections, with reconstitution of fully 60% of pre-lesion axon density arising from sprouting of spinal cord midline-crossing axons. This extensive anatomical recovery was associated with improvement in coordinated muscle recruitment, hand function and locomotion. These findings identify what may be the most extensive natural recovery of mammalian axonal projections after nervous system injury observed to date, highlighting an important role for primate models in translational disease research

    Tumor Necrosis Factor Alpha Mediates GABAA Receptor Trafficking to the Plasma Membrane of Spinal Cord Neurons In Vivo

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    The proinflammatory cytokine TNFα contributes to cell death in central nervous system (CNS) disorders by altering synaptic neurotransmission. TNFα contributes to excitotoxicity by increasing GluA2-lacking AMPA receptor (AMPAR) trafficking to the neuronal plasma membrane. In vitro, increased AMPAR on the neuronal surface after TNFα exposure is associated with a rapid internalization of GABAA receptors (GABAARs), suggesting complex timing and dose dependency of the CNS's response to TNFα. However, the effect of TNFα on GABAAR trafficking in vivo remains unclear. We assessed the effect of TNFα nanoinjection on rapid GABAAR changes in rats (N = 30) using subcellular fractionation, quantitative western blotting, and confocal microscopy. GABAAR protein levels in membrane fractions of TNFα and vehicle-treated subjects were not significantly different by Western Blot, yet high-resolution quantitative confocal imaging revealed that TNFα induces GABAAR trafficking to synapses in a dose-dependent manner by 60 min. TNFα-mediated GABAAR trafficking represents a novel target for CNS excitotoxicity

    Diversity in Secondary Metabolites Including Mycotoxins from Strains of <i>Aspergillus </i>Section <i>Nigri </i>Isolated from Raw Cashew Nuts from Benin, West Africa

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    <p>In a previous study, raw cashew kernels were assayed for the fungal contamination focusin on strains belonging to the genus Aspergillus and on aflatoxins producers. These sample showed high contamination with Aspergillus section Nigri species and absence o aflatoxins. To investigate the diversity of secondary metabolites, including mycotoxins, th species of A. section Nigri may produce and thus threaten to contaminate the raw cashe kernels, 150 strains were isolated from cashew samples and assayed for their productio of secondary metabolites using liquid chromatography high resolution mass spectrometr (LC-HRMS). Seven species of black Aspergilli were isolated based on morphological an chemical identification: A.Tubingensis (44%), A. niger (32%), A. brasiliensis (10%), A. carbonariu (8.7%), A. luchuensis (2.7%), A. aculeatus (2%) and A. aculeatinus (0.7%). Fro these, 45 metabolites and their isomers were identified. Aurasperone and pyranonigrin A produced by all species excluding A. aculeatus and A. aculeatinus, were most prevalen and were encountered in 146 (97.3%) and 145 (95.7%) isolates, respectively. Three mycotoxin groups were detected: fumonisins (B2 and B4) (2.7%) ochratoxin A (13.3%), an secalonic acids (2%), indicating that these mycotoxins could occur in raw cashew nuts Thirty strains of black Aspergilli were randomly sampled for verification of species identit based on sequences of β-Tubulin and calmodulin genes. Among them, 27 isolates wer positive to the primers used and 11 were identified as A. niger, 7 as A.Tubingensis, 6 as A carbonarius, 2 as A. luchuensis and 1 as A. welwitschiae confirming the species names a based on morphology and chemical features. These strains clustered in 5 clades in A. sectio Nigri. Chemical profile clustering also showed also 5 groups confirming the speciespecific metabolites production.</p

    The in- or exclusion of non-breast cancer related death and contralateral breast cancer significantly affects estimated outcome probability in early breast cancer

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    A wide variation of definitions of recurrent disease and survival are used in the analyses of outcome of patients with early breast cancer. Explicit definitions with details both on endpoints and censoring are provided in less than half of published studies. We evaluated the effects of various definitions of survival and recurrent disease on estimated outcome in a prospectively determined cohort of 463 patients with primary breast cancer. Outcome estimates were determined both by the Kaplan–Meier and a competing risk method. In- or exclusion of contralateral breast cancer or non-disease related death in the definition of recurrent disease or survival significantly affects estimated outcome probability. The magnitude of this finding was dependent on patient-, tumour-, and treatment characteristics. Knowledge of the contribution of non-disease related death or contralateral breast cancer to estimated recurrent disease rate and overall death rate is indispensable for a correct interpretation and comparison of outcome analyses

    The impact of bone marrow sparing on organs at risk dose for cervical cancer: a Pareto front analysis

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    Background and purpose: To quantify the increase in bladder and rectum dose of a bone marrow sparing (BMS) VMAT strategy for primary treatment of locally advanced cervical cancer (LACC).Materials and methods: Twenty patients with stage IB-IVA cervical cancer were selected for this study. The whole Pelvic Bones (PB) was taken as substitute for bone marrow. For every patient, Pareto-optimal plans were generated to explore the trade-off between rectum, bladder, and PB mean dose. The PB mean dose was decreased in steps of 1 Gy. For each step, the increase in rectum and bladder mean dose was quantified. The increase in mean dose of other OAR compared to no BMS was constrained to 1 Gy.Results: In total, 931 plans of 19 evaluable patients were analyzed. The average [range] mean dose of PB without BMS was 22.8 [20.7-26.2] Gy. When maximum BMS was applied, the average reduction in mean PB dose was 5.4 [3.0-6.8] Gy resulting in an average mean PB dose of 17.5 [15.8-19.8] Gy. For 2 Gy, >3 Gy, >4 Gy, and >5 Gy for 19/19, 13/19, 5/19, and 1/19 patients, respectively.Conclusion: Based on the comprehensive three-dimensional Pareto front analysis, we conclude that 2-5 Gy BMS can be implemented without a clinically relevant increase in mean dose to other OAR. If BMS is too dominant, it results in a large increase in mean dose to other OAR. Therefore, we recommend implementing moderate BMS for the treatment of LACC patients with VMAT.Biological, physical and clinical aspects of cancer treatment with ionising radiatio

    Plan-library supported automated replanning for online-adaptive intensity-modulated proton therapy of cervical cancer

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    Background: Intensity-modulated proton therapy is sensitive to inter-fraction variations, including density changes along the pencil-beam paths and variations in organ-shape and location. Large dayto-day variations are seen for cervical cancer patients. The purpose of this study was to develop and evaluate a novel method for online selection of a plan from a patient-specific library of prior plans for different anatomies, and adapt it for the daily anatomy. Material and methods: The patient-specific library of prior plans accounting for altered target geometries was generated using a pretreatment established target motion model. Each fraction, the best fitting prior plan was selected. This prior plan was adapted using (1) a restoration of spot-positions (Bragg peaks) by adapting the energies to the new water equivalent path lengths; and (2) a spot addition to fully cover the target of the day, followed by a fast optimization of the spot-weights with the reference point method (RPM) to obtain a Pareto-optimal plan for the daily anatomy. Spot addition and spot-weight optimization could be repeated iteratively. The patient cohort consisted of six patients with in total 23 repeat-CT scans, with a prescribed dose of 45 Gy(RBE) to the primary tumor and the nodal CTV. Using a 1-plan-library (one prior plan based on all motion in the motion model) was compared to choosing from a 2-plan-library (two prior plans based on part of the motion). Results: Applying the prior-plan adaptation method with one iteration of adding spots resulted in clinically acceptable target coverage (V95% 95% and V107% 2%) for 37/46 plans using the 1-planlibrary and 41/46 plans for the 2-plan-library. When adding spots twice, the 2-plan-library approach could obtain acceptable coverage for all scans, while the 1-plan-library approach showed V107% > 2% for 3/46 plans. Similar OAR results were obtained. Conclusion: The automated prior-plan adaptation method can successfully adapt for the large day-today variations observed in cervical cancer patients

    Molecular Classification of Grade 3 Endometrioid Endometrial Cancers Identifies Distinct Prognostic Subgroups

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    Our aim was to investigate whether molecular classification can be used to refine prognosis in grade 3 endometrial endometrioid carcinomas (EECs). Grade 3 EECs were classified into 4 subgroups: p53 abnormal, based on mutant-like immunostaining (p53abn); MMR deficient, based on loss of mismatch repair protein expression (MMRd); presence of POLE exonuclease domain hotspot mutation (POLE); no specific molecular profile (NSMP), in which none of these aberrations were present. Overall survival (OS) and recurrence-free survival (RFS) rates were compared using the Kaplan-Meier method (Log-rank test) and univariable and multivariable Cox proportional hazard models. In total, 381 patients were included. The median age was 66 years (range, 33 to 96 y). Federation Internationale de Gynecologie et d'Obstetrique stages (2009) were as follows: IA, 171 (44.9%); IB, 120 (31.5%); II, 24 (6.3%); III, 50 (13.1%); IV, 11 (2.9%). There were 49 (12.9%) POLE, 79 (20.7%) p53abn, 115 (30.2%) NSMP, and 138 (36.2%) MMRd tumors. Median follow-up of patients was 6.1 years (range, 0.2 to 17.0 y). Compared to patients with NSMP, patients with POLE mutant grade 3 EEC (OS: hazard ratio [HR], 0.36 [95% confidence interval, 0.18-0.70]; P=0.003; RFS: HR, 0.17 [0.05-0.54]; P=0.003) had a significantly better prognosis; patients with p53abn tumors had a significantly worse RFS (HR, 1.73 [1.09-2.74]; P=0.021); patients with MMRd tumors showed a trend toward better RFS. Estimated 5-year OS rates were as follows: POLE 89%, MMRd 75%, NSMP 69%, p53abn 55% (Log rank P=0.001). Five-year RFS rates were as follows: POLE 96%, MMRd 77%, NSMP 64%, p53abn 47% (P=0.000001), respectively. In a multivariable Cox model that included age and Federation Internationale de Gynecologie et d'Obstetrique stage, POLE and MMRd status remained independent prognostic factors for better RFS; p53 status was an independent prognostic factor for worse RFS. Molecular classification of grade 3 EECs reveals that these tumors are a mixture of molecular subtypes of endometrial carcinoma, rather than a homogeneous group. The addition of molecular markers identifies prognostic subgroups, with potential therapeutic implications
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