19 research outputs found
Modeling Chronic Traumatic Encephalopathy: The Way Forward for Future Discovery
Despite the extensive media coverage associated with the diagnosis of chronic traumatic encephalopathy (CTE), our fundamental understanding of the disease pathophysiology remains in its infancy. Only recently have scientific laboratories and personnel begun to explore CTE pathophysiology through the use of preclinical models of neurotrauma. Some studies have shown the ability to recapitulate some aspects of CTE in rodent models, through the use of various neuropathologic, biochemical, and/or behavioral assays. Many questions related to CTE development however remain unanswered. These include the role of impact severity, the time interval between impacts, the age at which impacts occur, and the total number of impacts sustained. Other important variables such as the location of impacts, character of impacts, and effect of environment/lifestyle and genetics also warrant further study. In this work we attempt to address some of these questions by exploring work previously completed using single and repetitive injury paradigms. Despite some models producing some deficits similar to CTE symptoms, it is clear that further studies are required to understand the development of neuropathological and neurobehavioral features consistent with CTE-like features in rodents. Specifically, acute and chronic studies are needed that characterize the development of tau-based pathology
The quest to model chronic traumatic encephalopathy: a multiple model and injury paradigm experience
Chronic neurodegeneration following a history of neurotrauma is frequently associated with neuropsychiatric and cognitive symptoms. In order to enhance understanding about the underlying pathophysiology linking neurotrauma to neurodegeneration, a multi-model preclinical approach must be established to account for the different injury paradigms and pathophysiologic mechanisms. We investigated the development of tau pathology and behavioral changes using a multi-model and multi-institutional approach, comparing the preclinical results to tauopathy patterns seen in post-mortem human samples from athletes diagnosed with chronic traumatic encephalopathy (CTE). We utilized a scaled and validated blast-induced traumatic brain injury model in rats and a modified pneumatic closed-head impact model in mice. Tau hyperphosphorylation was evaluated by western blot and immunohistochemistry. Elevated-plus maze and Morris water maze were employed to measure impulsive-like behavior and cognitive deficits respectively. Animals exposed to single blast (~50 PSI reflected peak overpressure) exhibited elevated AT8 immunoreactivity in the contralateral hippocampus at 1 month compared to controls (q = 3.96, p \u3c 0.05). Animals exposed to repeat blast (six blasts over 2 weeks) had increased AT8 (q = 8.12, p \u3c 0.001) and AT270 (q = 4.03, p \u3c 0.05) in the contralateral hippocampus at 1 month post-injury compared to controls. In the modified controlled closed-head impact mouse model, no significant difference in AT8 was seen at 7 days, however a significant elevation was detected at 1 month following injury in the ipsilateral hippocampus compared to control (q = 4.34, p \u3c 0.05). Elevated-plus maze data revealed that rats exposed to single blast (q = 3.53, p \u3c 0.05) and repeat blast (q = 4.21, p \u3c 0.05) spent more time in seconds exploring the open arms compared to controls. Morris water maze testing revealed a significant difference between groups in acquisition times on days 22â27. During the probe trial, single blast (t = 6.44, p \u3c 0.05) and repeat blast (t = 8.00, p \u3c 0.05) rats spent less time in seconds exploring where the platform had been located compared to controls. This study provides a multi-model example of replicating tau and behavioral changes in animals and provides a foundation for future investigation of CTE disease pathophysiology and therapeutic development
TRY plant trait database â enhanced coverage and open access
Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of traitâbased plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for âplant growth formâ. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and traitâenvironmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
Conservative management of a cervical ligamentum flavum hematoma: Case report
BACKGROUND: Spontaneous epidural hematoma arising from the ligamentum flavum is a rare cause of acute spinal cord compression. There are only four reports in the cervical spine literature, and all were managed with surgery. Here, we describe an acute case of a spontaneous epidural hematoma arising from the ligamentum flavum in the cervical spine successfully managed without surgery. CASE DESCRIPTION: A 69-year-old woman with a cervical spine epidural hematoma contained within the ligamentum flavum presented with paroxysmal neck pain and stiffness without a history of trauma. The magnetic resonance imaging (MRI) revealed a posterolateral epidural hematoma contained within the ligamentum flavum. As the patient was intact, she was managed conservatively with cervical orthosis. Three months later, she was symptom-free, and the hematoma resolved on the follow-up MRI study. CONCLUSION: Spontaneous epidural hematoma arising from ligamentum flavum is a rare cause of spinal cord compression. Previous reports have described success with surgical decompression. However, initial observation and conservative management may be successful as illustrated in this case
Leber congenital amaurosis associated with Chiari I malformation: Two cases and a review of the literature
Ventriculosubgaleal Shunting - A Strategy to Reduce the Incidence of Shunt Revisions and Slit Ventricles: An Institutional Experience and Review of the Literature
Background/Aims: Slit ventricles and multiple episodes of shunt failure are problematic in many infants and preterm neonates shunted for hydrocephalus. We utilized ventriculosubgaleal (VSG) shunting as the initial neurosurgical intervention in neonates with hydrocephalus associated with intraventricular hemorrhage and infants with myelomeningocele. Methods: We conducted a chart review of 21 children initially treated with a VSG shunt between November 2002 and July 2009. Patient records and imaging studies were reviewed. Demographics, case data and clinical outcome were collected. Results: Five patients (27.8%) required a revision after conversion to a ventriculoperitoneal (VP) shunt. There were 9 cases of radiographic slit ventricles (45%). Average follow-up was 59.5 months (range 12-97 months). Average time interval to shunt conversion was 81.5 days. Two patients have not required conversion to a VP shunt (one with an 8-year follow-up). To date, none of these patients has required a subtemporal window or cranial vault expansion. Conclusion: Based on our results, initial management of selected hydrocephalic infants with a VSG shunt may prove to be advantageous in the long run for these children as the number of shunt revisions and the incidence of slit ventricles are significantly less than those reported in the literature. Copyright (C) 2011 S. Karger AG, Base
Enhanced Oral Bioavailability of ÎČ-Caryophyllene in Healthy Subjects Using the VESIsorbÂź Formulation Technology, a Novel Self-Emulsifying Drug Delivery System (SEDDS)
ÎČ-Caryophyllene (BCP), a common constituent of many spice and food plants, is gaining increased attention due to recent research identifying numerous potential health benefits. Due to limited oral bioavailability observed in preclinical models, the described benefits of BCP may be maximized by using a suitable delivery system. Additionally, human pharmacokinetics (PK) remain unknown. This study evaluates the relative oral bioavailability of BCP formulated in a self-emulsifying drug delivery system (SEDDS) based on VESIsorbÂź formulation technology (BCP-SEDDS) compared to BCP neat oil. Hence, a randomized, double-blind, cross-over design, single oral dose study (100 mg BCP) in 24 healthy subjects (12 men/12 women) was performed under fasting conditions. Pharmacokinetic parameters were analyzed from individual concentration-time curves. The data show that BCP-SEDDS resulted in a 2.2/2.0-fold increase in AUC0â12h/AUC0â24h and a 3.6-fold increase in Cmax compared to BCP neat oil. Moreover, BCP was absorbed faster from BCP-SEDDS (Tmax: 1.43 h) compared to BCP neat oil (Tmax: 3.07 h). Gender analysis revealed that there is no significant difference between men and women for both the investigated formulations and all investigated PK endpoints. In conclusion, BCP-SEDDS offers a well-tolerated and effective oral delivery system to significantly enhance the oral bioavailability of BCP in humans