Publications by authors named "William Buchta"

27 Publications

  • Page 1 of 1

Dynamic CRMP2 Regulation of CaV2.2 in the Prefrontal Cortex Contributes to the Reinstatement of Cocaine Seeking.

Mol Neurobiol 2020 Jan 29;57(1):346-357. Epub 2019 Jul 29.

Department of Neuroscience, Medical University of South Carolina (MUSC), 410C Basic Sciences Building, 173 Ashley Avenue, Charleston, SC, 29425, USA.

Cocaine addiction remains a major health concern with limited effective treatment options. A better understanding of mechanisms underlying relapse may help inform the development of new pharmacotherapies. Emerging evidence suggests that collapsin response mediator protein 2 (CRMP2) regulates presynaptic excitatory neurotransmission and contributes to pathological changes during diseases, such as neuropathic pain and substance use disorders. We examined the role of CRMP2 and its interactions with a known binding partner, CaV2.2, in cocaine-seeking behavior. We employed the rodent self-administration model of relapse to drug seeking and focused on the prefrontal cortex (PFC) for its well-established role in reinstatement behaviors. Our results indicated that repeated cocaine self-administration resulted in a dynamic and persistent alteration in the PFC expression of CRMP2 and its binding partner, the CaV2.2 (N-type) voltage-gated calcium channel. Following cocaine self-administration and extinction training, the expression of both CRMP2 and CaV2.2 was reduced relative to yoked saline controls. By contrast, cued reinstatement potentiated CRMP2 expression and increased CaV2.2 expression above extinction levels. Lastly, we utilized the recently developed peptide myr-TAT-CBD3 to disrupt the interaction between CRMP2 and CaV2.2 in vivo. We assessed the reinstatement behavior after infusing this peptide directly into the medial PFC and found that it decreased cue-induced reinstatement of cocaine seeking. Taken together, these data suggest that neuroadaptations in the CRMP2/CaV2.2 signaling cascade in the PFC can facilitate drug-seeking behavior. Targeting such interactions has implications for the treatment of cocaine relapse behavior.
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http://dx.doi.org/10.1007/s12035-019-01711-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6980501PMC
January 2020

Tuberculosis Screening, Testing, and Treatment of U.S. Health Care Personnel: Recommendations from the National Tuberculosis Controllers Association and CDC, 2019.

MMWR Morb Mortal Wkly Rep 2019 May 17;68(19):439-443. Epub 2019 May 17.

The 2005 CDC guidelines for preventing Mycobacterium tuberculosis transmission in health care settings include recommendations for baseline tuberculosis (TB) screening of all U.S. health care personnel and annual testing for health care personnel working in medium-risk settings or settings with potential for ongoing transmission (1). Using evidence from a systematic review conducted by a National Tuberculosis Controllers Association (NTCA)-CDC work group, and following methods adapted from the Guide to Community Preventive Services (2,3), the 2005 CDC recommendations for testing U.S. health care personnel have been updated and now include 1) TB screening with an individual risk assessment and symptom evaluation at baseline (preplacement); 2) TB testing with an interferon-gamma release assay (IGRA) or a tuberculin skin test (TST) for persons without documented prior TB disease or latent TB infection (LTBI); 3) no routine serial TB testing at any interval after baseline in the absence of a known exposure or ongoing transmission; 4) encouragement of treatment for all health care personnel with untreated LTBI, unless treatment is contraindicated; 5) annual symptom screening for health care personnel with untreated LTBI; and 6) annual TB education of all health care personnel.
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http://dx.doi.org/10.15585/mmwr.mm6819a3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6522077PMC
May 2019

Supercontinuum-laser diffuse reflectance spectroscopy in conjunction with an extended Kubelka-Munk model-a methodology for determination of temperature-dependent quantum efficiency in highly scattering and fluorescent media.

Appl Opt 2019 Apr;58(10):2438-2445

Temperature-dependent diffuse reflectance measurements on Cr-doped -alumina monoliths have been performed using supercontinuum-laser illumination and -laser heating. These measurements have been interpreted using an extended Kubelka-Munk (K-M) model describing diffuse-light propagation in highly scattering and fluorescent media to assess the temperature dependence of fluorescence quantum efficiency. Analysis of experimental results has provided a qualitative understanding of the temperature-dependent conditions for model applicability and also suggests methods for using supercontinuum-laser diffuse reflectance spectroscopy for detection of unknown fluorescent dopants.
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http://dx.doi.org/10.1364/AO.58.002438DOI Listing
April 2019

A Photoactivatable Botulinum Neurotoxin for Inducible Control of Neurotransmission.

Neuron 2019 03 28;101(5):863-875.e6. Epub 2019 Jan 28.

Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA. Electronic address:

Regulated secretion is critical for diverse biological processes ranging from immune and endocrine signaling to synaptic transmission. Botulinum and tetanus neurotoxins, which specifically proteolyze vesicle fusion proteins involved in regulated secretion, have been widely used as experimental tools to block these processes. Genetic expression of these toxins in the nervous system has been a powerful approach for disrupting neurotransmitter release within defined circuitry, but their current utility in the brain and elsewhere remains limited by lack of spatial and temporal control. Here we engineered botulinum neurotoxin B so that it can be activated with blue light. We demonstrate the utility of this approach for inducibly disrupting excitatory neurotransmission, providing a first-in-class optogenetic tool for persistent, light-triggered synaptic inhibition. In addition to blocking neurotransmitter release, this approach will have broad utility for conditionally disrupting regulated secretion of diverse bioactive molecules, including neuropeptides, neuromodulators, hormones, and immune molecules. VIDEO ABSTRACT.
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http://dx.doi.org/10.1016/j.neuron.2019.01.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6524650PMC
March 2019

Experimental characterization and physics-based modeling of the temperature-dependent diffuse reflectance of plasma-sprayed NdZrO in the near to short-wave infrared.

Appl Opt 2018 Sep;57(27):7782-7792

Supercontinuum-laser illumination in conjunction with CO-laser heating has been implemented to measure the near to short-wave infrared (970-1660 nm) diffuse reflectance of plasma-sprayed NdZrO as a function of temperature. Owing to the broadband nature of this experimental technique, the diffuse reflectance of plasma-sprayed NdZrO has been measured at many wavelengths and has been shown to decrease with increasing temperature. A physics-based model for diffuse reflectance predicated on the crystal/electronic band structure of highly scattering semiconductor materials has been constructed to interpret the results of these measurements. Baseline materials characterization has also been performed to assist in the development of crystal/electronic band structure-optical property relationships that could be useful for the design of next-generation environmental barrier coatings. This characterization has included ambient and non-ambient x-ray diffraction as well as room-temperature, integrating-sphere diffuse reflectance spectroscopy.
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http://dx.doi.org/10.1364/AO.57.007782DOI Listing
September 2018

Chemogenetic Manipulations of Ventral Tegmental Area Dopamine Neurons Reveal Multifaceted Roles in Cocaine Abuse.

J Neurosci 2019 01 16;39(3):503-518. Epub 2018 Nov 16.

Brain Health Institute, Rutgers University, Piscataway, New Jersey 08854.

Ventral tegmental area (VTA) dopamine (DA) neurons perform diverse functions in motivation and cognition, but their precise roles in addiction-related behaviors are still debated. Here, we targeted VTA DA neurons for bidirectional chemogenetic modulation during specific tests of cocaine reinforcement, demand, and relapse-related behaviors in male rats, querying the roles of DA neuron inhibitory and excitatory G-protein signaling in these processes. Designer receptor stimulation of G signaling, but not G signaling, in DA neurons enhanced cocaine seeking via functionally distinct projections to forebrain limbic regions. In contrast, engaging inhibitory G signaling in DA neurons blunted the reinforcing and priming effects of cocaine, reduced stress-potentiated reinstatement, and altered behavioral strategies for cocaine seeking and taking. Results demonstrate that DA neurons play several distinct roles in cocaine seeking, depending on behavioral context, G-protein-signaling cascades, and DA neuron efferent targets, highlighting their multifaceted roles in addiction. G-protein-coupled receptors are crucial modulators of ventral tegmental area (VTA) dopamine neuron activity, but how this metabotropic signaling impacts the complex roles of dopamine in reward and addiction is poorly understood. Here, we bidirectionally modulate dopamine neuron G-protein signaling with DREADDs (designer receptors exclusively activated by designer drugs) during a variety of cocaine-seeking behaviors, revealing nuanced, pathway-specific roles in cocaine reward, effortful seeking, and relapse-like behaviors. G and G stimulation activated dopamine neurons, but only G stimulation robustly enhanced cocaine seeking. G inhibitory signaling reduced some, but not all, types of cocaine seeking. Results show that VTA dopamine neurons modulate numerous distinct aspects of cocaine addiction- and relapse-related behaviors, and point to potential new approaches for intervening in these processes to treat addiction.
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http://dx.doi.org/10.1523/JNEUROSCI.0537-18.2018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6335749PMC
January 2019

Restoration of Kv7 Channel-Mediated Inhibition Reduces Cued-Reinstatement of Cocaine Seeking.

J Neurosci 2018 04 10;38(17):4212-4229. Epub 2018 Apr 10.

Department of Neuroscience,

Cocaine addicts display increased sensitivity to drug-associated cues, due in part to changes in the prelimbic prefrontal cortex (PL-PFC). The cellular mechanisms underlying cue-induced reinstatement of cocaine seeking remain unknown. Reinforcement learning for addictive drugs may produce persistent maladaptations in intrinsic excitability within sparse subsets of PFC pyramidal neurons. Using a model of relapse in male rats, we sampled >600 neurons to examine spike frequency adaptation (SFA) and afterhyperpolarizations (AHPs), two systems that attenuate low-frequency inputs to regulate neuronal synchronization. We observed that training to self-administer cocaine or nondrug (sucrose) reinforcers decreased SFA and AHPs in a subpopulation of PL-PFC neurons. Only with cocaine did the resulting hyperexcitability persist through extinction training and increase during reinstatement. In neurons with intact SFA, dopamine enhanced excitability by inhibiting Kv7 potassium channels that mediate SFA. However, dopamine effects were occluded in neurons from cocaine-experienced rats, where SFA and AHPs were reduced. Pharmacological stabilization of Kv7 channels with retigabine restored SFA and Kv7 channel function in neuroadapted cells. When microinjected bilaterally into the PL-PFC 10 min before reinstatement testing, retigabine reduced cue-induced reinstatement of cocaine seeking. Last, using cFos-GFP transgenic rats, we found that the loss of SFA correlated with the expression of cFos-GFP following both extinction and re-exposure to drug-associated cues. Together, these data suggest that cocaine self-administration desensitizes inhibitory Kv7 channels in a subpopulation of PL-PFC neurons. This subpopulation of neurons may represent a persistent neural ensemble responsible for driving drug seeking in response to cues. Long after the cessation of drug use, cues associated with cocaine still elicit drug-seeking behavior, in part by activation of the prelimbic prefrontal cortex (PL-PFC). The underlying cellular mechanisms governing these activated neurons remain unclear. Using a rat model of relapse to cocaine seeking, we identified a population of PL-PFC neurons that become hyperexcitable following chronic cocaine self-administration. These neurons show persistent loss of spike frequency adaptation, reduced afterhyperpolarizations, decreased sensitivity to dopamine, and reduced Kv7 channel-mediated inhibition. Stabilization of Kv7 channel function with retigabine normalized neuronal excitability, restored Kv7 channel currents, and reduced drug-seeking behavior when administered into the PL-PFC before reinstatement. These data highlight a persistent adaptation in a subset of PL-PFC neurons that may contribute to relapse vulnerability.
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http://dx.doi.org/10.1523/JNEUROSCI.2767-17.2018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5963852PMC
April 2018

Temperature-dependent diffuse reflectance spectroscopy of plasma-sprayed Cr-doped α-alumina using supercontinuum laser illumination and CO laser heating.

Appl Opt 2017 Sep;56(27):7618-7628

This study presents results for the high-temperature (up to 1550 K) optical properties of polycrystalline Cr-doped α-alumina materials. Diffuse reflectance spectra in the wavelength range of 510-840 nm are presented as a function of temperature to illustrate changes to the optical behavior of these materials including a previously unreported thermally activated splitting of the U-band absorption (A4→T4) in octahedrally coordinated Cr. Measurements were made using a unique laser-based approach for high-temperature solid-state spectroscopy, involving front-side supercontinuum laser illumination and back-side CO laser heating. This approach required development of samples that could withstand related thermal stresses, and measurements were made on plasma-sprayed, Cr-doped α-alumina monoliths. Measured spectra are interpreted, in part, using published optical spectra for ruby; agreement between results here with those obtained using more traditional methods serves to validate the measurement methods used for this work.
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http://dx.doi.org/10.1364/AO.56.007618DOI Listing
September 2017

Dopamine terminals from the ventral tegmental area gate intrinsic inhibition in the prefrontal cortex.

Physiol Rep 2017 Mar;5(6)

Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina

Spike frequency adaptation (SFA or accommodation) and calcium-activated potassium channels that underlie after-hyperpolarization potentials (AHP) regulate repetitive firing of neurons. Precisely how neuromodulators such as dopamine from the ventral tegmental area (VTA) regulate SFA and AHP (together referred to as ) in the prefrontal cortex (PFC) remains unclear. Using whole cell electrophysiology, we measured intrinsic inhibition in prelimbic (PL) layer 5 pyramidal cells of male adult rats. Results demonstrate that bath application of dopamine reduced intrinsic inhibition (EC: 25.0 mol/L). This dopamine action was facilitated by coapplication of cocaine (1 mol/L), a blocker of dopamine reuptake. To evaluate VTA dopamine terminals in PFC slices, we transfected VTA dopamine cells of rats in vivo with Cre-dependent AAVs to express channelrhodopsin-2 (ChR2) or designer receptors exclusively activated by designer drugs (DREADDS). In PFC slices from these animals, stimulation of VTA terminals with either blue light to activate ChR2 or bath application of clozapine-N-oxide (CNO) to activate Gq-DREADDs produced a similar reduction in intrinsic inhibition in PL neurons. Electrophysiological recordings from cells expressing retrograde fluorescent tracers showed that this plasticity occurs in PL neurons projecting to the accumbens core. Collectively, these data highlight an ability of VTA terminals to gate intrinsic inhibition in the PFC, and under appropriate circumstances, enhance PL neuronal firing. These cellular actions of dopamine may be important for dopamine-dependent behaviors involving cocaine and cue-reward associations within cortical-striatal circuits.
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http://dx.doi.org/10.14814/phy2.13198DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5371565PMC
March 2017

Proficiency in identifying, managing and communicating medical errors: feasibility and validity study assessing two core competencies.

BMC Med Educ 2016 Sep 2;16(1):233. Epub 2016 Sep 2.

Division of Preventive, Occupational, and Aerospace Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.

Background: Communication skills and professionalism are two competencies in graduate medical education that are challenging to evaluate. We aimed to develop, test and validate a de novo instrument to evaluate these two competencies.

Methods: Using an Objective Standardized Clinical Examination (OSCE) based on a medication error scenario, we developed an assessment instrument that focuses on distinctive domains [context of discussion, communication and detection of error, management of error, empathy, use of electronic medical record (EMR) and electronic medical information resources (EMIR), and global rating]. The aim was to test feasibility, acceptability, and reliability of the method.

Results: Faculty and standardized patients (SPs) evaluated 56 trainees using the instrument. The inter-rater reliability of agreement between faculty was substantial (Fleiss k = 0.71) and intraclass correlation efficient was excellent (ICC = 0.80). The measured agreement between faculty and SPs evaluation of resident was lower (Fleiss k = 0.36). The instrument showed good conformity (ICC = 0.74). The majority of the trainees (75 %) had satisfactory or higher performance in all six assessed domains and 86 % found the OSCE to be realistic. Sixty percent reported not receiving feedback on EMR use and asked for subsequent training.

Conclusion: An OSCE-based instrument using a medical error scenario can be used to assess competency in professionalism, communication, using EMRs and managing medical errors.
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http://dx.doi.org/10.1186/s12909-016-0755-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5010770PMC
September 2016

Cumulative Faults with Serial Testing for Latent Tuberculosis in Low-Risk Populations.

Ann Am Thorac Soc 2016 07;13(7):1187-8

3 Mayo Clinic Rochester, Minnesota.

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http://dx.doi.org/10.1513/AnnalsATS.201603-213LEDOI Listing
July 2016

Applying quality improvement methods in a hyperbaric oxygen program: reducing unnecessary glucose testing.

Undersea Hyperb Med 2016 Jul-Aug;43(4):427-435

Division of Preventive, Occupational and Aerospace Medicine, Mayo Clinic, Rochester, Minnesota, U.S.

Objective: To describe the implementation of a quality improvement (QI) project that aimed at improving and standardizing glucose checks on patients with diabetes undergoing hyperbaric oxygen (HBO₂) therapy.

Methods: This is a prospective cohort study. Following the Model for Improvement, nurses and physicians ran several Plan-Do-Study-Act (PDSA) cycles over a four-month period, with multiple iteration and testing changes. They developed and implemented a nurse-led protocol that was tested prospectively.

Results: Compared to the pre-protocol baseline (N = 332), glucose checks per session guided by the protocol decreased by 37.7% (2.84 vs. 1.77 per session, P⟨0.001). Compliance with the new protocol was higher than compliance with the existing protocol (97.3% to 84.2%, P⟨0.001). There were no cases of a symptomatic hypoglycemic event after the implementation of the protocol.

Conclusions: A quality improvement project implemented by a multidisciplinary team in a hyperbaric practice was feasible and has improved the management of diabetic patients undergoing HBO₂ therapy. Considering how the hyperbaric community values the culture of safety and considering the feasibility of this project, more QI training and projects in hyperbaric programs should be performed.
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November 2017

The incidence of hypoglycemia during HBO2 therapy: A retrospective review.

Undersea Hyperb Med 2015 May-Jun;42(3):191-6

Background: Hypoglycemia is concerning in patients with diabetes undergoing hyperbaric oxygen (HBO2) therapy. We aimed to estimate the incidence, risk factors and a pretreatment glucose threshold of HBO2-associated hypoglycemia.

Methods: We retrospectively evaluated a patient cohort undergoing HBO2 therapy. We calculated the area under the curve (AUC) and odds ratio (OR) with 95% confidence interval (CI) adjusting for patients' age, gender, diabetes type, insulin use, body mass index, hemoglobin A1c and HBO2 treatment time.

Results: During 77 months, 3,136 HBO2 sessions were performed on patients with diabetes. In-chamber glucose was higher than pre-HBO2 glucose in 1,708/3,136 sessions (54%). The incidence of hypoglycemia (defined as ≤ 70 mg/dL) during or immediately after HBO2 treatment was 1.5% (0.8-2.1%). Hypoglycemia that was symptomatic or severe was rare. A glucose value pre-HBO2 of 150 mg/dL best predicted the risk of subsequent hypoglycemia (AUC 0.80; 95% CI, 0.75-0.86). Type 1 diabetes was independently associated with increased risk of hypoglycemia (OR 3.69; 95% CI, 1.67, 8.19) whereas insulin use was not.

Conclusions: In patients with diabetes undergoing HBO2, severe hypoglycemia is rare and occurs more frequently in Type 1 diabetes. Pre-HBO2 glucose values may be used to predict subsequent hypoglycemia and reduce the need for routine glucose monitoring during and after HBO2.
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July 2015

Chronic cocaine disrupts mesocortical learning mechanisms.

Brain Res 2015 Dec 20;1628(Pt A):88-103. Epub 2015 Feb 20.

Neurobiology of Addiction Research Center (NARC), Medical University of South Carolina, Charleston, SC 29425, USA. Electronic address:

The addictive power of drugs of abuse such as cocaine comes from their ability to hijack natural reward and plasticity mechanisms mediated by dopamine signaling in the brain. Reward learning involves burst firing of midbrain dopamine neurons in response to rewards and cues predictive of reward. The resulting release of dopamine in terminal regions is thought to act as a teaching signaling to areas such as the prefrontal cortex and striatum. In this review, we posit that a pool of extrasynaptic dopaminergic D1-like receptors activated in response to dopamine neuron burst firing serve to enable synaptic plasticity in the prefrontal cortex in response to rewards and their cues. We propose that disruptions in these mechanisms following chronic cocaine use contribute to addiction pathology, in part due to the unique architecture of the mesocortical pathway. By blocking dopamine reuptake in the cortex, cocaine elevates dopamine signaling at these extrasynaptic receptors, prolonging D1-receptor activation and the subsequent activation of intracellular signaling cascades, and thus inducing long-lasting maladaptive plasticity. These cellular adaptations may account for many of the changes in cortical function observed in drug addicts, including an enduring vulnerability to relapse. Therefore, understanding and targeting these neuroadaptations may provide cognitive benefits and help prevent relapse in human drug addicts.
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http://dx.doi.org/10.1016/j.brainres.2015.02.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4739740PMC
December 2015

CRF-R2 and the heterosynaptic regulation of VTA glutamate during reinstatement of cocaine seeking.

J Neurosci 2014 Jul;34(31):10402-14

Medical University of South Carolina, Charleston, South Carolina 29425

Stress can reinstate cocaine seeking through an interaction between the stress hormone corticotropin releasing factor (CRF) and glutamate release onto dopamine neurons in the ventral tegmental area (VTA). To better understand the underlying causes, synaptic mechanisms were investigated in brain slices from rats. In control tissue, EPSCs displayed concentration-dependent, bimodal responses to CRF potentiation at low concentrations (3-100 nm) and attenuation at higher concentrations (300 nm). EPSC potentiation and attenuation were mediated by CRF-R1 and CRF-R2 receptor subtypes, respectively, localized to presynaptic terminals. The CRF-R2 attenuation was blocked by the GABA-B receptor antagonist CGP55843. Additional recordings of GABA-A IPSCs showed CRF-R2 activation-facilitated presynaptic release of GABA, suggesting that CRF-R2 may regulate glutamate release via heterosynaptic facilitation of GABA synapses. After chronic cocaine self-administration and extinction training, the sensitivity of glutamate and GABA receptors was unchanged. However, the ability of CRF-R2 agonists to depress EPSCs and potentiate IPSCs was diminished. After yohimbine plus cue reinstatement, the actions of CRF-R2 on GABA and glutamate release were reversed. CRF-R2 activation increased EPSCs as a result of a reduction of tonic GABA-dependent inhibition. After reinstatement, application of the A1 adenosine antagonist 1,3-dipropyl-8-cyclopentylxanthine increased GABA tone to inhibit the CRF-R2 action. Blockade of GABA-B receptors prevented both the CRF-R2 increase in EPSCs and the attenuation produced by 1,3-dipropyl-8-cyclopentylxanthine. These studies demonstrate that presynaptic CRF-R1/R2 tightly regulate glutamate transmission in the VTA via a concerted, heterosynaptic manner that may become altered by stress-related pathologies, such as addiction.
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http://dx.doi.org/10.1523/JNEUROSCI.0911-13.2014DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4115144PMC
July 2014

Research doesn't support mandatory influenza vaccination.

Authors:
William G Buchta

WMJ 2012 Jun;111(3):96

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June 2012

Serotonin transporter inhibition attenuates l-DOPA-induced dyskinesia without compromising l-DOPA efficacy in hemi-parkinsonian rats.

Eur J Neurosci 2012 Sep 5;36(6):2839-48. Epub 2012 Jul 5.

Behavioral Neuroscience Program, Department of Psychology, Binghamton University, 4400 Vestal Parkway East, Binghamton, NY 13902-6000, USA.

Long-term dopamine replacement therapy with l-DOPA in Parkinson's disease often leads to the development of abnormal involuntary movements known as l-DOPA-induced dyskinesia. Growing evidence suggests that, following dopamine cell loss, serotonin neurons acting as surrogates for dopaminergic processes take up l-DOPA, convert it to dopamine and release it in an unregulated fashion that precipitates dyskinesia. Although most studies have focused on serotonin 5-HT(1) receptor stimulation as an antidyskinetic strategy, targeting the serotonin transporter modulation of dopamine activity has been overlooked. Therefore, in the current study, selective serotonin reuptake inhibitors were tested for their ability to reduce l-DOPA- and apomorphine-induced dyskinesia. In Experiments 1 and 2, hemi-parkinsonian rats were primed with l-DOPA until stable dyskinesia developed. Rats in Experiment 1 were administered the selective serotonin reuptake inhibitors paroxetine, citalopram or fluoxetine, followed by l-DOPA. Abnormal involuntary movements and forepaw adjusting steps were recorded to determine the effects of these compounds on dyskinesia and motor performance, respectively. Brains were collected on the final test day, after which striatal and raphe monoamines were examined via high-performance liquid chromatography. In Experiment 2, dyskinesias were measured after selective serotonin reuptake inhibitors and apomorphine. Serotonin reuptake inhibitors dose-dependently attenuated l-DOPA- but not apomorphine-induced dyskinesia, and preserved l-DOPA efficacy. Neurochemically, serotonin transporter inhibition enhanced striatal and raphe serotonin levels and reduced its turnover, indicating a potential mechanism of action. The present results support targeting serotonin transporters to improve Parkinson's disease treatment and provide further evidence for the role of the serotonin system in l-DOPA's effects.
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http://dx.doi.org/10.1111/j.1460-9568.2012.08202.xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3445783PMC
September 2012

Is an occupational examination superior to an occupational health history alone for preplacement screening in health care settings?

J Occup Environ Med 2012 Mar;54(3):276-9

Mayo Clinic Division of Preventive, Occupational and Aerospace Medicine, Department of Medicine, Mayo Clinic, Rochester, MN 55901, USA.

Objectives: To determine whether preplacement recommendations following an occupationally focused medical history is different from those following an occupational consultation.

Methods: This was a retrospective cohort study of 172 applicants to our institution.

Results: Following provider review of occupational history survey alone, none of the applicants had restrictions recommended. In comparison, only 163 applicants (94.7%) were recommended to be hired without restrictions following provider review of the same patient's occupational history and examination (P = 0.0078).

Conclusion: A well-designed questionnaire is useful for screening applicants for preplacement examinations and assures sufficient detail to allow for a large proportion of individuals to proceed to employment without an occupational examination. However, in this study, a small but statistically significant portion (5%) of applicants required occupational examinations for appropriate work recommendations.
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http://dx.doi.org/10.1097/JOM.0b013e318246f1b7DOI Listing
March 2012

Preemployment screening for tuberculosis in a large health care setting: comparison of the tuberculin skin test and a whole-blood interferon-γ release assay.

J Occup Environ Med 2011 Mar;53(3):290-3

Oklahoma State Department of Health Public Health Laboratory, Oklahoma City, OK, USA.

Objective: Determine the performance of an interferon-γ release assay in a health care occupational surveillance program.

Methods: From January 11, 2005, through January 31, 2006, all new employees (n = 652) undergoing standard, preemployment evaluation at Mayo Clinic, Rochester, Minnesota were evaluated for tuberculosis using a standard process of symptom screening combined with tuberculin skin test (TST) and QuantiFERON-TB Gold test (QFT-G).

Results: Comparing the results of QFT-G directly to TST, QFT-G showed an overall agreement of 92.5%.

Conclusions: False-positive TST were the most significant issue affecting agreement, and in a low-tuberculosis prevalence population, the need for an effective strategy offering low false-positive results may be best met by combining the TST with QFT-G.
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http://dx.doi.org/10.1097/JOM.0b013e31820c91c5DOI Listing
March 2011

Hyperbaric oxygen therapy for chronic refractory osteomyelitis of the sternum.

Ann Thorac Surg 2010 May;89(5):1661-3

Division of Cardiovascular Diseases, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.

This report describes a 32-year-old woman with chronic refractory osteomyelitis of the sternum after multiple surgical procedures including a sternotomy with underlying colonic interposition that was successfully managed with hyperbaric oxygen therapy. The clinical course is reviewed, and the complexities of this diagnosis are then discussed, including a brief review of the mechanisms of management with hyperbaric oxygen therapy.
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http://dx.doi.org/10.1016/j.athoracsur.2009.10.018DOI Listing
May 2010

The prevention and treatment of pertussis.

Manag Care Interface 2007 Feb;20(2):43-6

Division of Primary Care Internal Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.

Since 2004, more than 25,000 cases of pertussis have been reported in the United States each year. Symptoms in adults range from mild cough to severe persistent cough with posttussive emesis. The characteristic paroxysmal cough (whoop) may be absent, and the diagnosis is often missed, especially when the cough is mild. The most useful diagnostic test to confirm pertussis is a polymerase chain reaction assay of a nasopharyngeal swab sample. Patients are infectious for three weeks from the cough onset. Antibiotic treatment, preferably with macrolide antibiotics, is indicated during this time for pertussis treatment and prophylaxis. In 2005, two new acellular pertussis vaccines were licensed: one (Boostrix) for patients aged 10 to 18 years and another (Adacel) for patients aged 11 to 64 years.
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February 2007

Telemedicine applications in occupational medicine.

Minn Med 2006 Nov;89(11):46-8

Mayo Clinic, USA.

Telemedicine combines telecommunication technology and medicine to increase access to health care services for patients living in remote areas and enhance the efficiency of delivering that care. This article describes the results of a Mayo Clinic pilot study on the use of telemedicine in an occupational medicine clinic for Mayo Clinic employees and their dependents. The study involved 21 patients who came for initial evaluations for work-related problems or injuries, follow-up visits, visits for acute problems such as low-back pain, and periodic health evaluations. It found that patients and providers were comfortable with the technology after a short training session and satisfied with the outcomes of the visits. More rigorous research evaluating the applications of telemedicine in occupational health care is needed.
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November 2006
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