Recommendations for reproducibility of cerebrospinal fluid extracellular vesicle studies

Cerebrospinal fluid (CSF) is a clear, transparent fluid derived from blood plasma that protects the brain and spinal cord against mechanical shock, provides buoyancy, clears metabolic waste and transports extracellular components to remote sites in the brain. Given its contact with the brain and the spinal cord, CSF is the most informative biofluid for studies of the central nervous system (CNS). In addition to other components, CSF contains extracellular vesicles (EVs) that carry bioactive cargoes (e.g., lipids, nucleic acids, proteins), and that can have biological functions within and beyond the CNS. Thus, CSF EVs likely serve as both mediators of and contributors to communication in the CNS. Accordingly, their potential as biomarkers for CNS diseases has stimulated much excitement for and attention to CSF EV research. However, studies on CSF EVs present unique challenges relative to EV studies in other biofluids, including the invasive nature of CSF collection, limited CSF volumes and the low numbers of EVs in CSF as compared to plasma. Here, the objectives of the International Society for Extracellular Vesicles CSF Task Force are to promote the reproducibility of CSF EV studies by providing current reporting and best practices, and recommendations and reporting guidelines, for CSF EV studies. To accomplish this, we created and distributed a world‐wide survey to ISEV members to assess methods considered ‘best practices’ for CSF EVs, then performed a detailed literature review for CSF EV publications that was used to curate methods and resources. Based on responses to the survey and curated information from publications, the CSF Task Force herein provides recommendations and reporting guidelines to promote the reproducibility of CSF EV studies in seven domains: (i) CSF Collection, Processing, and Storage; (ii) CSF EV Separation/Concentration; (iii) CSF EV Size and Number Measurements; (iv) CSF EV Protein Studies; (v) CSF EV RNA Studies; (vi) CSF EV Omics Studies and (vii) CSF EV Functional Studies

Progesterone treatment shows benefit in a pediatric model of moderate to severe bilateral brain injury.

Controlled cortical impact (CCI) models in adult and aged Sprague-Dawley (SD) rats have been used extensively to study medial prefrontal cortex (mPFC) injury and the effects of post-injury progesterone treatment, but the hormone's effects after traumatic brain injury (TBI) in juvenile animals have not been determined. In the present proof-of-concept study we investigated whether progesterone had neuroprotective effects in a pediatric model of moderate to severe bilateral brain injury.Twenty-eight-day old (PND 28) male Sprague Dawley rats received sham (n = 24) or CCI (n = 47) injury and were given progesterone (4, 8, or 16 mg/kg per 100 g body weight) or vehicle injections on post-injury days (PID) 1-7, subjected to behavioral testing from PID 9-27, and analyzed for lesion size at PID 28.The 8 and 16 mg/kg doses of progesterone were observed to be most beneficial in reducing the effect of CCI on lesion size and behavior in PND 28 male SD rats.Our findings suggest that a midline CCI injury to the frontal cortex will reliably produce a moderate TBI comparable to what is seen in the adult male rat and that progesterone can ameliorate the injury-induced deficits

Trend of Age-Adjusted Rates of Pediatric Traumatic Brain Injury in U.S. Emergency Departments from 2006 to 2013

Objective: To use the 2006–2013 Nationwide Emergency Department Sample (NEDS) database to describe trends of age-adjusted rates of pediatric traumatic brain injuries (TBI) treated in U.S. emergency departments. Methods: Time trend analysis was conducted on age-adjusted rates among children ≤17 years in the U.S. The annual percent change (APC) was calculated by fitting a least squares regression to the logarithm of the rates, using the calendar year as an independent variable. Results: In males, motor-vehicle-related trauma (APC −2.5%) and severe TBI (APC −3.6%) decreased over the study time period. Conversely, concussion (APC 5.1%), unspecified head injury (APC 6.6%), fall-related TBI (APC 7.1%), and mild TBI (APC 5.9%) increased. In females, severe TBI (APC −3.3%) decreased over the study time period and concussion (APC 6.5%), unspecified head injury (APC 7.2%), fall-related TBI (APC 7.6%), and mild TBI (APC 6.8%) increased. Conclusion: The overall age-adjusted rates of pediatric TBI-related emergency department (ED) visits increased from 2006 to 2013, which is largely caused by pediatric mild TBIs, especially unspecified injury to the head (ICD-9-CM code 959.01) and concussion. In comparison, age-adjusted rates of pediatric severe TBIs decreased. A major contributing factor might be a reduced number of traffic-related head trauma

Neuroendoscopic Resection of Intraventricular Tumors and Cysts through a Working Channel with a Variable Aspiration Tissue Resector: A Feasibility and Safety Study

Pure neuroendoscopic resection of intraventricular lesions through a burr hole is limited by the instrumentation that can be used with a working channel endoscope. We describe a safety and feasibility study of a variable aspiration tissue resector, for the resection of a variety of intraventricular lesions. Our initial experience using the variable aspiration tissue resector involved 16 patients with a variety of intraventricular tumors or cysts. Nine patients (56%) presented with obstructive hydrocephalus. Patient ages ranged from 20 to 88 years (mean 44.2). All patients were operated on through a frontal burr hole, using a working channel endoscope. A total of 4 tumors were resected in a gross total fashion and the remaining intraventricular lesions were subtotally resected. Fifteen of 16 patients had relief of their preoperative symptoms. The 9 patients who presented with obstructive hydrocephalus had restoration of cerebrospinal fluid flow though one required a ventriculoperitoneal shunt. Three patients required repeat endoscopic resections. Use of a variable aspiration tissue resector provides the ability to resect a variety of intraventricular lesions in a safe, controlled manner through a working channel endoscope. Larger intraventricular tumors continue to pose a challenge for complete removal of intraventricular lesions

Dose-response effect of progesterone on learning and memory task as assessed by latency to locate the MWM platform.

<p>During Run 1 (<b>a</b>) on the acquisition phase there was a significant effect of CCI injury and all three doses of progesterone proved beneficial by decreasing the mean latency latency to find a hidden platform in the MWM compared to the CCI+ vehicle treated group. There was no clear effect of CCI injury on Run 2 (<b>b</b>) or during the reversal phase (p>0.05). * =  mean values are significantly different from sham; n = 8–9. PROG =  progesterone.</p

Immunoparalysis in Pediatric Critical Care

Although many forms of critical illness are initiated by a proinflammatory stimulus, a compensatory anti-inflammatory response can occur with systemic inflammation. Immunoparalysis, an important form of acquired immunodeficiency, affects the innate and adaptive arms of the immune system. Immunoparalysis has been associated with increased risks for nosocomial infection and death in a variety of pediatric critical illnesses. Evidence suggests that immunoparalysis is reversible with immunostimulants. Highly standardized, prospective immune monitoring regimens are needed to better understand the immunologic effects of critical care treatment regimens and to enrich clinical trials with subjects most likely to benefit from immunostimulatory therapies

Lesion reconstruction analysis of CCI rat pups treated with progesterone vs. vehicle.

<p>Mean percent (±SEM) of volumetric tissue loss at the six anterior to posterior (A/P) levels examined between groups at 4 weeks post-injury. * =  significant difference between the CCI vehicle-treated group and CCI rats given (8 or 16 mg/kg dose of) progesterone. # =  significant difference between CCI group and both sham groups regardless of progesterone dose administered (<i>p</i><0.05). Values are mean ±SEM (n = 8–9/group). PROG =  progesterone.</p

Estrogen attenuates glutamate-induced cell death by inhibiting Ca 2+ influx through L-type voltage-gated Ca 2+ channels

Estrogen-mediated neuroprotection is observed in neurodegenerative disease and neurotrauma models; however, determining a mechanism for these effects has been difficult. We propose that estrogen may limit cell death in the nervous system tissue by inhibiting increases in intracellular free Ca 2+ . Here, we present data using VSC 4.1 cell line, a ventral spinal motoneuron and neuroblastoma hybrid cell line. Treatment with 1 mM glutamate for 24 h induced apoptosis. When cells were pre-treated with 100 nM 17β-estradiol (estrogen) for 1 h and then co-treated with glutamate, apoptotic death was significantly attenuated. Estrogen also prevented glutamate-mediated changes in resting membrane potential and membrane capacitance. Treatment with either 17α-estradiol or cell impermeable estrogen did not mimic the findings seen with estrogen. Glutamate treatment significantly increased both intracellular free Ca 2+ and the activities of downstream proteases such as calpain and caspase-3. Estrogen attenuated both the increases in intracellular free Ca 2+ and protease activities. In order to determine the pathway responsible for estrogen-mediated inhibition of these increases in intracellular Introduction Glutamate has a pivotal role both in normal function of the central nervous system (CNS) and in the pathophysiology of neurodegenerative disease

Dose-response effect on Spontaneous Activity test.

<p>Mean distance travelled (<b>a</b>), mean time spent at rest (<b>b</b>), Ambulatory responses (<b>c</b>) and stereotypic responses (<b>d</b>). Although CCI had a significant effect on spontaneous activity across test days, across the group there was no observed significant effect of Lesion/Treatment. * =  significant difference from baseline within each group. Values are mean ±SEM (n = 8–9). PROG =  progesterone.</p