Activation of Glutamate Transport Increases Arteriole Diameter in v ivo: Implications for Neurovascular Coupling.

In order to meet the energetic demands of cell-to-cell signaling, increases in local neuronal signaling are matched by a coordinated increase in local blood flow, termed neurovascular coupling. Multiple different signals from neurons, astrocytes, and pericytes contribute to this control of blood flow. Previously, several groups demonstrated that inhibition/ablation of glutamate transporters attenuates the neurovascular response. However, it was not determined if glutamate transporter activation was sufficient to increase blood flow. Here, we used multiphoton imaging to monitor the diameter of fluorescently labeled cortical arterioles in anesthetized C57/B6J mice. We delivered vehicle, glutamate transporter substrates, or a combination of a glutamate transporter substrate with various pharmacologic agents via a glass micropipette while simultaneously visualizing changes in arteriole diameter. We developed a novel image analysis method to automate the measurement of arteriole diameter in these time-lapse analyses. Using this workflow, we first conducted pilot experiments in which we focally applied L-glutamate, D-aspartate, or L-threo-hydroxyaspartate (L-THA) and measured arteriole responses as proof of concept. We subsequently applied the selective glutamate transport substrate L-THA (applied at concentrations that do not activate glutamate receptors). We found that L-THA evoked a significantly larger dilation than that observed with focal saline application. This response was blocked by co-application of the potent glutamate transport inhibitor, L-(2S,3S)-3-[3-[4-(trifluoromethyl)-benzoylamino]benzyloxy]-aspartate (TFB-TBOA). Conversely, we were unable to demonstrate a reduction of this effect through co-application of a cocktail of glutamate and GABA receptor antagonists. These studies provide the first direct evidence that activation of glutamate transport is sufficient to increase arteriole diameter. We explored potential downstream mechanisms mediating this transporter-mediated dilation by using a Ca2+ chelator or inhibitors of reversed-mode Na+/Ca2+ exchange, nitric oxide synthetase, or cyclo-oxygenase. The estimated effects and confidence intervals suggested some form of inhibition for a number of these inhibitors. Limitations to our study design prevented definitive conclusions with respect to these downstream inhibitors; these limitations are discussed along with possible next steps. Understanding the mechanisms that control blood flow are important because changes in blood flow/energy supply are implicated in several neurodegenerative disorders and are used as a surrogate measure of neuronal activity in widely used techniques such as functional magnetic resonance imaging (fMRI).

Memantine for the Treatment of Behavioral Disturbance in Unspecified Major Neurocognitive Disorder.

In this case report, we aimed to examine how the use of memantine in an elderly gentleman with unspecified major neurocognitive disorder (NCD) led to significant clinical improvement in his behavioral disturbances. After presenting to the psychiatric ward due to aggressive behavior at his assisted living facility, the patient continued to exhibit numerous disruptive and confrontational behaviors while hospitalized. Memantine was started at 5 mg daily with gradual titration up to 10 mg twice daily over the course of four weeks, with marked improvement in behavior as well as an increase in Montreal Cognitive Assessment (MoCA) score by five points after seven weeks of treatment. Given our experience and the safety profile of memantine, we conclude that memantine may have a role in the treatment of behavioral disturbances in patients with unspecified major NCD, though further research will be necessary to define this role.

The Chinese (Mandarin) instructions of the 6-minute walk test: A validation study.

BACKGROUND/OBJECTIVE: To date, a validated Chinese (Mandarin) six-minute walk test (6MWT) translated instruction is not available. Translation of the Chinese 6MWT instruction is done in an ad hoc manner within the Chinese-speaking populations. This study aimed to develop a set of valid and reliable Chinese (Mandarin) instructions of the 6MWT. METHODS: Translation was performed from the original English instruction via the recommended "Process of translation and adaptation of instruments" by the World Health Organization to generate the Chinese instructions. The Chinese instructions were tested with 52 healthy adult participants for its validity. Each participant underwent three 6MWTs and a cardiopulmonary exercise test. Randomization allowed participants to undergo the walk test in both the original English and the new Chinese instructions. Face and content validity, intra-rater and inter-rater reliability of the Chinese instructions of the 6MWT were established through the translation process. Criterion validity was established by analyzing the results of the 6MWT and cardiopulmonary exercise test. RESULTS: Intraclass correlation coefficient for inter-rater reliability was excellent ( ICC = 0 . 999 , 95% confidence interval = 0 . 996 -1.000). Similarly, the intra-rater reliability across the three raters was high (R1: ICC = 0 . 996 , 95% confidence interval ( CI )= 0 . 812 -1.000; R2: ICC = 1 . 000 , 95% CI = 0 . 994 -1.000; R3: ICC = 1 . 000 , 95% CI = 0 . 998 -1.000). The 6-min walk distances collected from the Chinese and English instructed trials correlated positively with the maximal oxygen consumption ( r = 0 . 315 , p = 0 . 023 ; r = 0 . 309 , p = 0 . 026 ). CONCLUSION: This is the first study to develop and validate the Chinese (Mandarin) instructions of the 6MWT, and the translation is as reliable and valid as the original English instructions.

Real-time in situ auto-correction of K+ interference for continuous and long-term NH4+ monitoring in wastewater using solid-state ion selective membrane (S-ISM) sensor assembly.

Potassium ions (K+) present in wastewater has caused severe interference for NH4+ monitoring, over-estimation of NH4+ concentration and ultimately leads to extra energy consumption. Past effort for enhancing the selectivity of NH4+ over K+ were oftentimes complex, costly, or compromised the selectivity and accuracy of the NH4+ ion selective membrane (ISM) sensors. This study targeted this imminent challenge by developing an integrated NH4+/K+ auto-correction solid-state ISM (S-ISM) sensor assembly combined with a data-driven model to monitor [NH4+] under different [NH4+] and [K+] concentrations. The results showed that the interference of K+ was substantially alleviated for NH4+ measurement. The accuracy was enhanced by over 70% when examined using real wastewater and energy consumption was expected to reduce by 26% for a wastewater treatment plant, especially for wastewater with high [K+]. Furthermore, the uniquely structured S-ISMs were made by embedding the ionophores in a robust polyvinyl chloride (PVC) matrix containing plasticizers and a layer of carbon nanotubes (CNT) as ion-to-electron transducer, which maintained the selectivity and accuracy of the S-ISM sensor for 4 weeks in wastewater. NH4+/K+ sensor assembly integrated with data-driven correction models poses great potential in high-efficiency and energy-saving wastewater treatment and water reuse processes.

Glutamate Transporters and Mitochondria: Signaling, Co-compartmentalization, Functional Coupling, and Future Directions.

In addition to being an amino acid that is incorporated into proteins, glutamate is the most abundant neurotransmitter in the mammalian CNS, the precursor for the inhibitory neurotransmitter γ-aminobutyric acid, and one metabolic step from the tricarboxylic acid cycle intermediate α-ketoglutarate. Extracellular glutamate is cleared by a family of Na+-dependent transporters. These transporters are variably expressed by all cell types in the nervous system, but the bulk of clearance is into astrocytes. GLT-1 and GLAST (also called EAAT2 and EAAT1) mediate this activity and are extremely abundant proteins with their expression enriched in fine astrocyte processes. In this review, we will focus on three topics related to these astrocytic glutamate transporters. First, these transporters co-transport three Na+ ions and a H+ with each molecule of glutamate and counter-transport one K+; they are also coupled to a Cl- conductance. The movement of Na+ is sufficient to cause profound astrocytic depolarization, and the movement of H+ is linked to astrocytic acidification. In addition, the movement of Na+ can trigger the activation of Na+ co-transporters (e.g. Na+-Ca2+ exchangers). We will describe the ways in which these ionic movements have been linked as signals to brain function and/or metabolism. Second, these transporters co-compartmentalize with mitochondria, potentially providing a mechanism to supply glutamate to mitochondria as a source of fuel for the brain. We will provide an overview of the proteins involved, discuss the evidence that glutamate is oxidized, and then highlight some of the un-resolved issues related to glutamate oxidation. Finally, we will review evidence that ischemic insults (stroke or oxygen/glucose deprivation) cause changes in these astrocytic mitochondria and discuss the ways in which these changes have been linked to glutamate transport, glutamate transport-dependent signaling, and altered glutamate metabolism. We conclude with a broader summary of some of the unresolved issues.

Real-Time in Situ Monitoring of Nitrogen Dynamics in Wastewater Treatment Processes using Wireless, Solid-State, and Ion-Selective Membrane Sensors.

Real-time, in situ accurate monitoring of nitrogen contaminants in wastewater over a long-term period is critical for swift feedback control, enhanced nitrogen removal efficiency, and reduced energy consumption of wastewater treatment processes. Existing nitrogen sensors suffer from high cost, low stability, and short life times, posing hurdles for their mass deployment to capture a complete picture within heterogeneous systems. Tackling this challenge, this study presents solid-state ion-selective membrane (S-ISM) nitrogen sensors for ammonium (NH4+) and nitrate (NO3-) in wastewater that were coupled to a wireless data transmission gateway for real-time remote data access. Lab-scale test and continuous-flow field tests using real municipal wastewater indicated that the S-ISM nitrogen sensors possessed excellent accuracy and precision, high selectivity, and multiday stability. Importantly, autocorrections of the sensor readings on the cloud minimized temperature influences and assured accurate nitrogen concentration readings in remote-sensing applications. It was estimated that real-time, in situ monitoring using wireless S-ISM nitrogen sensors could save 25% of electric energy under normal operational conditions and reduce 22% of nitrogen discharge under shock conditions.

Correlative imaging reveals physiochemical heterogeneity of microcalcifications in human breast carcinomas.

Microcalcifications (MCs) are routinely used to detect breast cancer in mammography. Little is known, however, about their materials properties and associated organic matrix, or their correlation to breast cancer prognosis. We combine histopathology, Raman microscopy, and electron microscopy to image MCs within snap-frozen human breast tissue and generate micron-scale resolution correlative maps of crystalline phase, trace metals, particle morphology, and organic matrix chemical signatures within high grade ductal carcinoma in situ (DCIS) and invasive cancer. We reveal the heterogeneity of mineral-matrix pairings, including punctate apatitic particles (<2 µm) with associated trace elements (e.g., F, Na, and unexpectedly Al) distributed within the necrotic cores of DCIS, and both apatite and spheroidal whitlockite particles in invasive cancer within a matrix containing spectroscopic signatures of collagen, non-collagen proteins, cholesterol, carotenoids, and DNA. Among the three DCIS samples, we identify key similarities in MC morphology and distribution, supporting a dystrophic mineralization pathway. This multimodal methodology lays the groundwork for establishing MC heterogeneity in the context of breast cancer biology, and could dramatically improve current prognostic models.

Brain endothelial cells induce astrocytic expression of the glutamate transporter GLT-1 by a Notch-dependent mechanism.

Neuron-secreted factors induce astrocytic expression of the glutamate transporter, GLT-1 (excitatory amino acid transporter 2). In addition to their elaborate anatomic relationships with neurons, astrocytes also have processes that extend to and envelop the vasculature. Although previous studies have demonstrated that brain endothelia contribute to astrocyte differentiation and maturation, the effects of brain endothelia on astrocytic expression of GLT-1 have not been examined. In this study, we tested the hypothesis that endothelia induce expression of GLT-1 by co-culturing astrocytes from mice that utilize non-coding elements of the GLT-1 gene to control expression of reporter proteins with the mouse endothelial cell line, bEND.3. We found that endothelia increased steady state levels of reporter and GLT-1 mRNA/protein. Co-culturing with primary rat brain endothelia also increases reporter protein, GLT-1 protein, and GLT-1-mediated glutamate uptake. The Janus kinase/signal transducer and activator of transcription 3, bone morphogenic protein/transforming growth factor ß, and nitric oxide pathways have been implicated in endothelia-to-astrocyte signaling; we provide multiple lines of evidence that none of these pathways mediate the effects of endothelia on astrocytic GLT-1 expression. Using transwells with a semi-permeable membrane, we demonstrate that the effects of the bEND.3 cell line are dependent upon contact. Notch has also been implicated in endothelia-astrocyte signaling in vitro and in vivo. The first step of Notch signaling requires cleavage of Notch intracellular domain by γ-secretase. We demonstrate that the γ-secretase inhibitor N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester blocks endothelia-induced increases in GLT-1. We show that the levels of Notch intracellular domain are higher in nuclei of astrocytes co-cultured with endothelia, an effect also blocked by N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester. Finally, infection of co-cultures with shRNA directed against recombination signal binding protein for immunoglobulin kappa J, a Notch effector, also reduces endothelia-dependent increases in enhanced green fluorescent protein and GLT-1. Together, these studies support a novel role for Notch in endothelia-dependent induction of GLT-1 expression. Cover Image for this issue: doi. 10.1111/jnc.13825.

Buspirone for the treatment of dementia with behavioral disturbance.

Behavioral disturbances are common but serious symptoms in patients with dementia. Currently, there are no FDA approved drugs for this purpose. There have been case reports and small case series of the use of buspirone. In this retrospective study, we review 179 patients prescribed buspirone for treatment of behavioral disturbance in dementia to better characterize the efficacy and potential side effects. All patients prescribed buspirone for behavioral disturbance due to dementia from a geropsychiatric outreach program were reviewed. Data was collected and analyzed using SPSS. One hundred-seventy-nine patients met criteria for the study with a mean age of 83.8 + 7. Alzheimer's dementia was the most common dementia (n = 61; 34.1%) followed by mixed dementia (n = 50, 27.9%) then vascular type (n = 31; 17.3%). Behavioral disturbances were mainly verbal aggression (n = 125; 69.8%), and physical aggression (n = 116; 64.8%). Using the Clinical Global Impression scale, 68.6% of patients responded to buspirone, with 41.8% being moderately to markedly improved. The mean dose of buspirone was 25.7 mg ± 12.50. Buspirone appears to be effective in treating behavioral disturbances in dementia. Future prospective and double blinded studies are needed.

A Practice-Grounded Approach for Evaluating Health in All Policies Initiatives in the United States.

OBJECTIVE: To address the social determinants of health, an increasing number of public health practitioners are implementing Health in All Policies initiatives aimed at increasing cross-sectoral collaboration and integrating health considerations into decisions made by "nonhealth" sectors. Despite the growth in practice nationally and internationally, evaluation of Health in All Policies is a relatively new field. To help inform evaluation of Health in All Policies initiatives in the United States, this study sought to develop a practice-grounded approach, including a logic model and a set of potential indicators, which could be used to describe and assess Health in All Policies activities, outputs, and outcomes. DESIGN: Methods included (a) a review of the literature on current Health in All Policies approaches, practices, and evaluations; and (b) consultation with experts with substantive knowledge in implementing or evaluating Health in All Policies initiatives. Feedback from experts was obtained through individual (n = 11) and group (n = 14) consultation. RESULTS: The logic model depicts a range of potential inputs, activities, outputs, and outcomes of Health in All Policies initiatives; example indicators for each component of the logic model are provided. Case studies from California, Washington, and Nashville highlight emerging examples of Health in All Policies evaluation and the ways in which local context and goals inform evaluation efforts. CONCLUSION: The tools presented in this article synthesize concepts present in the emerging literature on Health in All Policies implementation and evaluation. Practitioners and researchers can use the tools to facilitate dialogue among stakeholders, clarify assumptions, identify how they will assess progress, and implement data-driven ways to improve their Health in All Policies work.

Prevalence of substance misuse in new patients in an outpatient psychiatry clinic using a prescription monitoring program.

OBJECTIVE: To investigate the value of a prescription monitoring program in identifying prescription drug misuse among patients presenting to a resident physician outpatient psychiatry clinic at an academic medical center. METHOD: Participants were 314 new patients aged 18 years or older presenting to the clinic from October 2011 to June 2012. Resident physicians completed a data collection form for each participant using information from the patient interview and from the prescription monitoring program report. Prescription drug misuse was defined as having any 1 of the following 5 criteria in the prescription monitoring program report: (1) filled prescriptions for 2 or more controlled substances, (2) obtained prescriptions from 2 or more providers, (3) obtained early refills, (4) used 3 or more pharmacies, and (5) the prescription monitoring program report conflicted with the patient's report. RESULTS: At least 1 indicator of prescription drug misuse was found in 41.7% of patients. Over 69% of the patients that the residents believed were misusing prescription drugs actually met 1 of the criteria for prescription drug misuse. The prescription monitoring program report changed the management only 2.2% of the time. Patients with prior benzodiazepine use (χ(2) 1 = 17.68, P < .001), prior opioid use (χ(2) 1 = 19.98, P < .001), a personality disorder (χ(2) 1 = 7.22, P < .001), and chronic pain (χ(2) 1 = 14.31, P < .001) had a higher percentage of prescription drug misuse compared to patients without these factors. CONCLUSION: Using the prescription monitoring program to screen patients with prior benzodiazepine and opioid use, with a personality disorder, and/or with chronic pain may be useful in confirming the suspicion of prescription drug misuse identified at the initial evaluation.

Chronic intranasal oxytocin causes long-term impairments in partner preference formation in male prairie voles.

BACKGROUND: Oxytocin (OT) is a hormone shown to be involved in social bonding in animal models. Intranasal OT is currently in clinical trials for use in disorders such as autism and schizophrenia. We examined long-term effects of intranasal OT given developmentally in the prairie vole (Microtus ochrogaster), a socially monogamous rodent, often used as an animal model to screen drugs that have therapeutic potential for social disorders. METHODS: We treated voles with one of three dosages of intranasal OT, or saline, from day 21 (weaning) through day 42 (sexual maturity). We examined both social behavior immediately following administration, as well as long-term changes in social and anxiety behavior after treatment ceased. Group sizes varied from 8 to 15 voles (n = 89 voles total). RESULTS: Treatment with OT resulted in acute increases in social behavior in male voles with familiar partners, as seen in humans. However, long-term developmental treatment with low doses of intranasal OT resulted in a deficit in partner preference behavior (a reduction of contact with a familiar opposite-sex partner, used to index pair-bond formation) by male voles. CONCLUSIONS: Long-term developmental treatment with OT may show results different to those predicted by short-term studies, as well as significant sex differences and dosage effects. Further animal study is crucial to determining safe and effective strategies for use of chronic intranasal OT, especially during development.

Integrated semiconductor optical sensors for cellular and neural imaging.

We review integrated optical sensors for functional brain imaging, localized index-of-refraction sensing as part of a lab-on-a-chip, and in vivo continuous monitoring of tumor and cancer stem cells. We present semiconductor-based sensors and imaging systems for these applications. Measured intrinsic optical signals and tissue optics simulations indicate the need for high dynamic range and low dark-current neural sensors. Simulated and measured reflectance spectra from our guided resonance filter demonstrate the capability for index-of-refraction sensing on cellular scales, compatible with integrated biosensors. Finally, we characterized a thermally evaporated emission filter that can be used to improve sensitivity for in vivo fluorescence sensing.