320 research outputs found
V559A and N822I double KIT mutant melanoma with predictable response to imatinib?
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/88125/1/j.1755-148X.2010.00822.x.pd
Management of Adverse Events Following Treatment With Anti‐Programmed Death‐1 Agents
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140047/1/onco1230.pd
Morphomics predicts response to ipilimumab in patients with stage IV melanoma
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113727/1/jso24003.pd
The gradient of the reinforcement landscape influences sensorimotor learning
© 2019 Cashaback et al. Consideration of previous successes and failures is essential to mastering a motor skill. Much of what we know about how humans and animals learn from such reinforcement feedback comes from experiments that involve sampling from a small number of discrete actions. Yet, it is less understood how we learn through reinforcement feedback when sampling from a continuous set of possible actions. Navigating a continuous set of possible actions likely requires using gradient information to maximize success. Here we addressed how humans adapt the aim of their hand when experiencing reinforcement feedback that was associated with a continuous set of possible actions. Specifically, we manipulated the change in the probability of reward given a change in motor action-the reinforcement gradient-to study its influence on learning. We found that participants learned faster when exposed to a steep gradient compared to a shallow gradient. Further, when initially positioned between a steep and a shallow gradient that rose in opposite directions, participants were more likely to ascend the steep gradient. We introduce a model that captures our results and several features of motor learning. Taken together, our work suggests that the sensorimotor system relies on temporally recent and spatially local gradient information to drive learning
Antihypertensive response to prolonged tempol in the spontaneously hypertensive rat
Antihypertensive response to prolonged tempol in the spontaneously hypertensive rat.IntroductionTempol is a permeant nitroxide superoxide dismutase (SOD) mimetic that lowers mean arterial pressure (MAP) in spontaneously hypertensive rats (SHRs). We investigated the hypothesis that the antihypertensive response entails a negative salt balance, blunting of plasma renin activity (PRA), endothelin-1 (ET-1), or catecholamines or correction of oxidative stress as indexed by 8-isoprostane prostaglandin F2α (PGF2α) (8-Iso).MethodsGroups (N = 6 to 8) of SHRs were infused for 2 weeks with vehicle or tempol (200 nmol/kg/min) or given tempol (2 mmol/L) in drinking water.ResultsTempol infusion reduced the MAP of anesthetized SHRs (150 ± 5 vs. 126 ± 6mm Hg) (P < 0.005). Oral tempol did not change the heart rate but reduced the MAP of conscious SHRs (-23 ± 6mm Hg) (P < 0.01) but not Wistar-Kyoto (WKY) rats. Tempol infusion increased the PRA (2.2 ± 0.2 vs. 5.0 ± 0.9 ng/mL/hour) (P < 0.005), did not change excretion of nitric oxide (NO) [NO2 + NO3 (NOx)], ET-1, or catecholamines but reduced excretion of 8-Iso (13.2 ± 1.4 vs. 9.6 ± 0.9 ng/24 hours; P < 0.01). Cumulative Na+ balance and gain in body weight were unaltered by tempol infusion. Tempol prevented a rise in MAP with high salt intake.ConclusionTempol corrects hypertension without a compensatory sympathoadrenal activation or salt retention. The response is independent of nitric oxide, endothelin, or catecholamines and occurs despite increased PRA. It is accompanied by a reduction in oxidative stress and is maintained during increased salt intake
Concurrent whole brain radiotherapy and bortezomib for brain metastasis
Abstract
Background
Survival of patients with brain metastasis particularly from historically more radio-resistant malignancies remains dismal. A phase I study of concurrent bortezomib and whole brain radiotherapy was conducted to determine the tolerance and safety of this approach in patients with previously untreated brain metastasis.
Methods
A phase I dose escalation study evaluated the safety of bortezomib (0.9, 1.1, 1.3, 1.5, and 1.7 mg/m2) given on days 1, 4, 8 and 11 of whole brain radiotherapy. Patients with confirmed brain metastasis were recruited for participation. The primary endpoint was the dose-limiting toxicity, defined as any ≥ grade 3 non-hematologic toxicity or grade ≥ 4 hematologic toxicity from the start of treatment to one month post irradiation. Time-to-Event Continual Reassessment Method (TITE-CRM) was used to determine dose escalation. A companion study of brain diffusion tensor imaging MRI was conducted on a subset of patients to assess changes in the brain that might predict delayed cognitive effects.
Results
Twenty-four patients were recruited and completed the planned therapy. Patients with melanoma accounted for 83% of all participants. The bortezomib dose was escalated as planned to the highest dose of 1.7 mg/m2/dose. No grade 4/5 toxicities related to treatment were observed. Two patients had grade 3 dose-limiting toxicities (hyponatremia and encephalopathy). A partial or minor response was observed in 38% of patients. Bortezomib showed greater demyelination in hippocampus-associated white matter structures on MRI one month after radiotherapy compared to patients not treated with bortezomib (increase in radial diffusivity +16.8% versus 4.8%; p = 0.0023).
Conclusions
Concurrent bortezomib and whole brain irradiation for brain metastasis is well tolerated at one month follow-up, but MRI changes that have been shown to predict delayed cognitive function can be detected within one month of treatment.http://deepblue.lib.umich.edu/bitstream/2027.42/112849/1/13014_2013_Article_928.pd
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