1,115 research outputs found

    Targeting Intracellular Calcium Stores Alleviates Neurological Morbidities in a DFP-Based Rat Model of Gulf War Illness

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    Gulf War Illness (GWI) is a chronic multi-symptom disorder afflicting the veterans of the First Gulf War, and includes neurological symptoms characterized by depression and memory deficits. Chronic exposure to organophosphates (OP) is considered a leading cause for GWI, yet its pathobiology is not fully understood. We recently observed chronic elevations in neuronal Ca2+ levels ([Ca2+]i) in an OP- diisopropyl fluorophosphate (DFP) based rat model for GWI. This study was aimed at identifying mechanisms underlying elevated [Ca2+]i in this DFP model and investigating whether their therapeutic targeting could improve GWI-like neurological morbidities. Male Sprague-Dawley rats (9-wks) were exposed to DFP (0.5 mg/kg, s.c, 1x-daily for 5-d) and at 3-mos post DFP exposure, behavior was assessed and rats were euthanized for protein estimations and ratiometric Fura-2 [Ca2+]i estimations in acutely dissociated hippocampal neurons. In DFP rats, a sustained elevation in intracellular Ca2+ levels occurred, and pharmacological blockade of Ca2+-induced Ca2+-release mechanisms significantly lowered elevated [Ca2+]i in DFP neurons. Significant reductions in the protein levels of the ryanodine receptor (RyR) stabilizing protein Calstabin2 were also noted. Such a post-translational modification would render RyR leaky resulting in sustained DFP [Ca2+]i elevations. Antagonism of RyR with levetiracetam significantly lower elevated [Ca2+]i in DFP neurons and improved GWI-like behavioral symptoms. Since Ca2+ is a major second messenger molecule, such chronic increases in its levels could underlie pathological synaptic plasticity that expresses itself as GWI morbidities. Our studies show that treatment with drugs targeted at blocking intracellular Ca2+ release could be effective therapies for GWI neurological morbidities

    Moving out of the Margins: Mattering and the International Student Experience

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    Deeply personal challenges confront all new students when they arrive at their college or university. Some of their core questions include: “Are we part of things; do we belong; are we central or marginal? Do we make a difference; do others care about us and make us feel we matter?” (Schlossberg, 1989, p. 6). For international students who may be marginalized by race, ethnicity, nationality, socioeconomic background or language, these questions can be particularly painful. This article recommends a new foundation for working with international students: mattering. It provides a theoretical background for the constructs of marginalization and mattering, examines their relevancy in the context of the experiences of international students, and begins to define strategies for colleges and universities to make international students feel that they do indeed matter

    Repeated low-dose organophosphate DFP exposure leads to the development of depression and cognitive impairment in a rat model of Gulf War Illness

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    Approximately 175,000 to 250,000 of the returning veterans from the 1991 Persian Gulf War exhibit chronic multi-symptom illnesses that includes neurologic co-morbidities such as depression, anxiety and cognitive impairments. Amongst a host of causative factors, exposure to low levels of the nerve agent Sarin has been strongly implicated for expression of Gulf War Illness (GWI). Nerve agents similar to pesticides are organophosphate (OP) compounds. There is evidence from civilian population that exposure to OPs such as in agricultural workers and nerve agents such as the survivors and first-responders of the Tokyo subway Sarin gas attack suffer from chronic neurological problems similar to GWI symptoms. Given this unique chemical profile, OPs are ideal to study the effects of nerve agents and develop models of GWI in civilian laboratories. In this study, we used repeated low-dose exposure to OP agent diisopropyl fluorophosphate (DFP) over a 5-day period to approximate the duration and level of Sarin exposure during the Persian Gulf War. We tested the rats at 3-months post DFP exposure. Using a battery of behavioral assays, we observed the presence of symptoms of chronic depression, anxiety and memory problems as characterized by increased immobility time in the Forced Swim Test, anhedonia in the Sucrose Preference Test, anxiety in the Elevated Plus Maze, and spatial memory impairments in the Object Location Test, respectively. Chronic low dose DFP exposure was also associated with hippocampal neuronal damage as characterized by the presence of Fluoro-Jade staining. Given that OP exposure is considered a leading cause of GWI related morbidities, this animal model will be ideally suited to study underlying molecular mechanisms for the expression of GWI neurological symptoms and identify drugs for the effective treatment of GWIs

    An Exploratory Study of Suboxone (Buprenorphine/ Naloxone) Film Splitting: Cutting Methods, Content Uniformity, and Stability

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    Suboxone films are U.S. Food and Drug Administration approved to treat opioid dependence. While the package insert states that films should not be cut, physicians often prescribe film fractions for treatment and tapering. There is no data to support this practice, and this study was initiated to evaluate cutting methods, content uniformity, and stability of split films. Suboxone 8-mg buprenorphine/2-mg naloxone films were split using four methods: 1) ruler/razor cut, 2) scissor cut, 3) fold/rip, and 4) fold/scissor cut. United States Pharmacopeia Chapter \u3c905\u3e was used to evaluate the weight variation and content uniformity of split films. The stability of split films stored in polybags was evaluated over 7 days. A stability-indicating high-performance liquid chromatography method was used for content uniformity and stability evaluation. The weight variation results were acceptable for the half films from all four cutting methods, but this was not true for the quarter films. The method of ruler/razor cut was determined most favorable and used for the content uniformity test. Based on the high-performance liquid chromatography results, the half films from the ruler/razor cut method met the passing criteria of United States Pharmacopeia Chapter \u3c905\u3e with acceptance values of 9.8 to 10.4 for buprenorphine and 8.4 to 11.5 for naloxone (≤15 is considered passing). The stability results indicated that both actives retained \u3e97.7% of initial strength. Four cutting methods were found to be acceptable for splitting Suboxone films into half but not quarter fractions. The half films from the ruler/razor cut method also passed United States Pharmacopeia Chapter \u3c905\u3e content uniformity test. Both actives remained stable for 7 days when the half films were stored in polybags at room temperature

    Chronic behavioral and cognitive deficits in a rat survival model of paraoxon toxicity

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    Organophosphate (OP) compounds, including paraoxon (POX), are similar to nerve agents such as sarin. There is a growing concern that OP agents could be weaponized to cause mass civilian causalities. We have developed a rodent survival model of POX toxicity that is being used to evaluate chronic morbidity and to screen for medical countermeasures against severe OP exposure. It is well known that the survivors of nerve gas and chronic OP exposure exhibit neurobehavioral deficits such as mood changes, depression, and memory impairments. In this study we investigated whether animals surviving severe POX exposure exhibited long-term neurological impairments. POX exposure produced overt signs of cholinergic toxicity. Rats were rescued using an optimized atropine, 2-PAM and diazepam therapy. Surviving rats were studied using established behavioral assays for identifying symptoms of depression and memory impairment 3-months after POX exposure. In the forced swim test, POX rats exhibited increased immobility time indicative of a despair-like state. In the sucrose preference test, POX rats consumed significantly less sucrose water indicating anhedonia-like condition. POX rats also displayed increased anxiety as characterized by significantly lower performance in the open arm of the elevated plus maze. Further, when tested with a novel object recognition paradigm, POX rats exhibited a negative discrimination ratio indicative of impaired recognition memory. The results indicate that this model of survival from severe POX exposure can be employed to study some of the molecular bases for OP-induced chronic behavioral and cognitive comorbidities and develop therapies for their treatment

    The use of primary dermal fibroblast cultures to evaluate type I collagen expression in the oim model mouse

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    Abstract only availableOsteogenesis imperfecta type III is a heritable disorder leading to impaired connective tissue function in type I collagen containing tissues including bone fragility, blue-grey sclera, short stature, and hearing loss. Normal type I collagen is a heterotrimeric molecule containing two pro1(I) collagen chains and a similar but genetically distinct pro2(I) collagen chain. The osteogenesis imperfecta murine (oim) model mouse produces only homotrimeric type I collagen due to a single nucleotide deletion in the COL1A2 gene resulting in a non-functional pro2(I) collagen chain. The result is expression of an abnormal type I collagen molecule which leads to the above phenotype. This study is aimed at developing a methodology whereby dermal fibroblast cultures can be utilized for a variety of assays, including type I collagen RNA and protein quantification. For genotype identification, primers flanking the site of the single nucleotide deletion allow for differentiation of wild type, heterozygous and homozygous animals at the genomic level. Upon confirmation, skin was removed from both oim and wildtype mice and the dermal layer harvested. Fibroblasts originating from the dermal layer of each genotype were then cultured and grown to confluence as separate cultures and the RNA and/or protein harvested from both cell types. Total RNA was harvested using the Qiagen RNeasy kit and used to make cDNA, which was then used in conjunction with specific PCR primers to differentiate between wildtype and oim transcripts. For protein studies, the cells were treated with ascorbic acid to maximize the production of collagen prior to harvesting. Type I collagen expression was then confirmed via a western blot using a type I collagen-specific antibody. Initial results indicate the presence of both pro1(I) and pro2(I) collagen chains from harvested wildtype dermal fibroblasts, while media harvested from oim dermal fibroblasts indicated the presence of only the pro1(I) collagen chains. These results confirm the in vivo protein expression profile seen in skin of both oim and wildtype mice is exhibited in vitro in the respective dermal fibroblast cultures. These results will allow us to quantitate pro1(I) and pro2(I) collagen mRNA and protein expression levels. Future experiments will include the quantitation of type I collagen mRNA levels using RT-PCR, as well as the use of densitometry to quantitate type I collagen protein levels by western blot analysis. This in turn promises to provide insight into the mechanism of formation of abnormal type I collagen in the oim model mouse.Life Sciences Undergraduate Research Opportunity Progra

    Development of status epilepticus, sustained calcium elevations and neuronal injury in a rat survival model of lethal paraoxon intoxication

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    Paraoxon (POX) is an active metabolite of organophosphate (OP) pesticide parathion that has been weaponized and used against civilian populations. Exposure to POX produces high mortality. OP poisoning is often associated with chronic neurological disorders. In this study, we optimize a rat survival model of lethal POX exposures in order to mimic both acute and long-term effects of POX intoxication. Male Sprague–Dawley rats injected with POX (4 mg/kg, ice-cold PBS, s.c.) produced a rapid cholinergic crisis that evolved into status epilepticus (SE) and death within 6–8 min. The EEG profile for POX induced SE was characterized and showed clinical and electrographic seizures with 7–10 Hz spike activity. Treatment of 100% lethal POX intoxication with an optimized three drug regimen (atropine, 2 mg/kg, i.p., 2-PAM, 25 mg/kg, i.m. and diazepam, 5 mg/kg, i.p.) promptly stopped SE and reduced acute mortality to 12% and chronic mortality to 18%. This model is ideally suited to test effective countermeasures against lethal POX exposure. Animals that survived the POX SE manifested prolonged elevations in hippocampal [Ca2+]i(Ca2+ plateau) and significant multifocal neuronal injury. POX SE induced Ca2+ plateau had its origin in Ca2+ release from intracellular Ca2+ stores since inhibition of ryanodine/IP3 receptor lowered elevated Ca2+ levels post SE. POX SE induced neuronal injury and alterations in Ca2+ dynamics may underlie some of the long term morbidity associated with OP toxicity

    Pharmacological Blockade of the Calcium Plateau Provides Neuroprotection Following Organophosphate Paraoxon Induced Status Epilepticus in Rats

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    Organophosphate (OP) compounds which include nerve agents and pesticides are considered chemical threat agents. Currently approved antidotes are crucial in limiting OP mediated acute mortality. However, survivors of lethal OP exposure exhibit delayed neuronal injury and chronic behavioral morbidities. In this study, we investigated neuroprotective capabilities of dantrolene and carisbamate in a rat survival model of paraoxon (POX) induced status epilepticus (SE). Significant elevations in hippocampal calcium levels were observed 48-h post POX SE survival, and treatment with dantrolene (10 mg/kg, i.m.) and carisbamate (90 mg/kg, i.m.) lowered these protracted calcium elevations. POX SE induced delayed neuronal injury as characterized by Fluoro Jade C labeling was observed in critical brain areas including the dentate gyrus, parietal cortex, amygdala, and thalamus. Dantrolene and carisbamate treatment provided significant neuroprotection against delayed neuronal damage in these brain regions when administered one-hour after POX-SE. These results indicate that dantrolene or carisbamate could be effective adjuvant therapies to the existing countermeasures to reduce neuronal injury and behavioral morbidities post OP SE survival

    Principles and Strategies for Monitoring Data Collection Integrity in a Multi-site Randomized Clinical Trial of a Behavioral Intervention

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    Although treatment fidelity strategies for enhancing the integrity of behavioral interventions have been well described, little has been written about monitoring data collection integrity. This article describes the principles and strategies developed to monitor data collection integrity of the "Stories and Music for Adolescent/Young Adult Resilience During Transplant" study (R01NR008583; U10CA098543; U10CA095861) -- a multi-site Children's Oncology Group randomized clinical trial of a music therapy intervention for adolescents and young adults undergoing stem cell transplant. The principles and strategies outlined in this article provide one model for development and evaluation of a data collection integrity monitoring plan for behavioral interventions that may be adapted by investigators and may be useful to funding agencies and grant application reviewers in evaluating proposals

    A ZERO-HOUR PHYSICAL ACTIVITY PROGRAM'S BENEFIT ON ACADEMIC ACHIEVEMENT IN ELEMENTARY AGED SCHOOL CHILDREN

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    With childhood obesity on the rise and the need for American children to be academically successful compared to peer nations, it is imperative that physical activity become part of the typical school day for all elementary aged school children. There is an understanding that physical activity not only benefits physical fitness and health, but that it positively affects children’s academic achievement. With only one-half of American children meeting the CDC’s recommendation of 60 minutes daily, the physical and cognitive effects of inactivity have been widespread and undeniable.When children engage in physical activity prior to the school day, their bodies will undergo physiological changes in regards to heart rate and increased blood flow to the brain leading to an increase in attention, focus, and positive mood thereby ultimately improving academic achievement. This quasi-experimental design studied 26 participants (13 intervention, 13 control; 3-5th grade) enrolled in an extended school program. Resting heart rates, PACER tests, and reading and math AimsWeb scores were collected before and after the exercise intervention consisting of 35-45 minutes of zero hour physical activity, 4 days a week for 5 weeks was implemented.The results from the study were assessed using two one-way between-groups analysis of covariance that compared the effectiveness of the physical activity intervention designed to improve academic achievement for both math and reading. After adjusting for pre-intervention scores, there was a significant difference in reading test scores for the zero hour physical activity intervention group F (1, 23) =6.157, p = .021 but not duplicated with math test scores F (1, 23) =.252, p=.621. A large effect size was also seen for the intervention’s reading scores with Cohen’s d =.73 for the intervention group as compared to d=.48 for the control group.Physical activity prior to the school day does positively affect academic achievement. Even the smallest positive significance should be interpreted as a triumph and certainly outweighs the potential risks of continuing down the path of physical inactivity. Educational administrators and teachers should consider the large body of evidence regarding the influence of physical activity on children’s ability to succeed in the classroom.Ph.D
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