In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

[Q]: Context: Benign esophageal strictures are frequently encountered pathologies occurring due to various reasons. Repeated dilatations may be needed, particularly in resistant strictures. This study aimed to evaluate patients who underwent repeated dilatations in our clinic due to resistant esophageal strictures.', 'Sixteen patients who underwent multiple dilatations in our clinic with the diagnosis of resistant benign esophageal stricture between 2007 and 2014 were studied for age, sex, etiology, symptoms, complications, number of dilatations, and intervals between dilatations. Under general anesthesia, all patients underwent dilatation with Savary-Gilliard bougie dilators with the help of rigid esophagoscopy.', 'In 10 of the patients, stenosis was cervical, and in others it was in the thoracic esophagus. The mean dilatation performance was 4.4 (range: 3-12). In 9 patients, dilatations were performed when the patients presented with the complaint of dysphagia. Following the initial dilatation performed for dysphagia, 7 patients underwent endoscopy and dilatation 3-5 times with 1-week intervals without waiting for the development of dysphagia symptoms. These patients developed no complications, and no stenting was needed. In 5 patients, restenosis developed despite multiple dilatations, and esophageal stent placement was performed.\Question: Is recurrent dilatation in resistant benign esophageal strictures : timing significant?
[A]: Dilatations performed at frequent intervals without waiting for the symptoms of dysphagia can contribute to safer and more effective results in resistant benign esophageal strictures.

[Q]: Context: Different apoptosis pathways activate caspase-3. In a study involving 27 patients with traumatic brain injury (TBI), higher caspase-3 levels were found in contusion brain tissue resected from non-survivors than from survivors. The objective of this study was to determine whether there is an association in TBI patients between serum caspase-3 levels (thus using an easier, quicker, less expensive and less invasive procedure) and mortality, in a larger series of patients.', 'We carried out a prospective, observational and multicenter study in six Spanish Hospital Intensive Care Units including 112 patients with severe TBI. All had Glasgow Coma Scale (GCS) scores lower than 9. Patients with an Injury Severity Score (ISS) in non-cranial aspects higher than 9 were excluded. Blood samples were collected on day 1 of TBI to measure serum caspas-3 levels. The endpoint was 30-day mortality.', 'We found that non-surviving patients (n = 31) showed higher (p = 0.003) serum caspase-3 levels compared to survivors (n = 81). Kaplan-Meier survival analysis showed a higher risk of death in TBI patients with serum caspase-3 levels >0.20 ng/mL than in patients with lower concentrations (Hazard Ratio = 3.15; 95% CI = 1.40 to 7.08; P < 0.001). Multiple logistic regression analysis showed that serum caspase-3 levels > 0.20 ng/mL were associated with mortality at 30 days in TBI patients controlling for Marshall CT classification, age and GCS (Odds ratio = 7.99; 95% CI = 2.116 to 36.744; P = 0.001).\Question: Are serum caspase-3 levels and mortality associated in patients with severe traumatic brain injury?
[A]: The association between serum caspase-3 levels and mortality in TBI patients was the major novel finding of our study.

[Q]: Context: Chronic high-frequency electrical deep brain stimulation (DBS) of the subcallosal cingulate region is currently being investigated clinically as a therapy for treatment of refractory depression. Experimental DBS of the homologous region, the ventromedial prefrontal cortex (VMPFC), in rodent models has previously demonstrated anti-depressant-like effects. Our goal was to determine if structural remodeling accompanies the alterations of brain function previously observed as a result of chronic DBS.', 'Here we applied 6h of high-frequency bilateral VMPFC DBS daily to 8 9-week old C57Bl/6 mice for 5days. We investigated the "micro-lesion" effect by using a sham stimulation group (8 mice) and a control group (8 mice with a hole drilled into the skull only). Whole brain anatomy was investigated post-mortem using high-resolution magnetic resonance imaging and areas demonstrating volumetric expansion were further investigated using histology and immunohistochemistry.', 'The DBS group demonstrated bilateral increases in whole hippocampus and the left thalamus volume compared to both sham and control groups. Local hippocampal and thalamic volume increases were also observed at the voxel-level; however these increases were observed in both DBS and sham groups. Follow-up immunohistochemistry in the hippocampus revealed DBS increased blood vessel size and synaptic density relative to the control group whereas the sham group demonstrated increased astrocyte size.\Question: Does deep brain stimulation of the ventromedial prefrontal cortex cause reorganization of neuronal processes and vasculature?
[A]:
Our work demonstrates that DBS not only works by altering function with neural circuits, but also by structurally altering circuits at the cellular level. Neuroplastic alterations may play a role in mediating the clinical efficacy of DBS therapy.