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This is a small pilot study using two psychological interventions aimed at maintaining health and well-being in women with metastatic breast cancer. Out of 100 women deemed eligible, 37 were randomly assigned to 4 weeks of training in self-hypnosis or to a Japanese healing method, Johrei, or to a wait-list control condition for three months. Participants were examined with quality of life and mood scales on two occasions, prior to training and again three or more months later. Most data were able to be collected on 14 participants. Following both interventions, patients were more composed and less anxious than controls. Hypnosis training increased and Johrei patients maintained energy levels. There was a positive change in anxiety levels and a general increase in other mood scores. Such results are relevant to a better quality of life. In conclusion, the participants in this pilot study appear to have benefited by not only maintaining but also often increasing their energy levels and decreasing anxiety and other debilitating emotional states that influence quality of life, health and well-being. [ABSTRACT FROM AUTHOR]

Prevalence of metabolic disturbances is higher among individuals with neurodevelopmental disorders (NDDs), yet this association has been largely overlooked. Investigation into human disease remains challenging, as a complete pathophysiological understanding relies on accurate modeling and highly controlled variables. Genetically engineered mouse models are widely used to gain insight into the biology of human NDDs, but research focus has been on behavioral and neurophysiological abnormalities. Such models not only allow for evaluating usefulness in reproducing human features, including similarities and discrepancies with rodent phenotypes, but they also represent a unique opportunity to observe and quantify novel anomalies. Here, we present the first characterization and comparison of basal metabolism in three mouse models of NDDs, namely, Down syndrome (DS; Dp(16)Yey/+ mice), 16p11.2 deletion syndrome (16pDel; 16p11.2 df/+ mice), and fragile X syndrome [FXS; Fmr1 knock-out (KO) mice] and their wild-type (WT) counterparts. Using the Comprehensive Lab Animal Monitoring System (CLAMS) coupled to EchoMRI, as well as quantification of key plasma metabolites by liquid chromatography mass spectrometry (LC-MS), our in vivo study reveals that each mouse model expresses a unique metabolic signature that is sex-specific, independent of the amount of food consumed and minimally influenced by physical activity. In particular, we identify striking differences in body composition, respiratory exchange ratio (RER), caloric expenditure (CE), and concentrations of circulating plasma metabolites related to mitochondrial function. Providing novel insight into NDD-associated metabolic alterations is an essential prerequisite for future preclinical and clinical interventions., (Copyright © 2021 Menzies et al.)

Background: Neuronal damage resulting from increased oxidative stress is important in the development of late onset/age-related Alzheimer's disease (LOAD). We have developed an oxidative stress-related mouse model of LOAD based on gene deletion of aldehyde dehydrogenase 2 (ALDH2), an enzyme important for the detoxification of endogenous aldehydes arising from lipid peroxidation. Compared to wildtype (WT) mice, the knockout (KO) mice exhibit AD-like pathologies and a progressive decline in recognition and spatial memory. This progression presumably has a morphological basis induced by oxidative damage., Objective: We performed morphometric analyses in the dorsal hippocampal CA1 region (dCA1) to determine if altered neuronal structure can help account for the progressive cognitive impairment in 3- to 12-month-old KO mice., Methods: Dendritic morphology was quantitatively analyzed by branched structured analysis and Sholl analysis following Golgi-Cox staining in WT mice (148 neurons) versus KO mice (180 neurons)., Results: The morphology and complexity of dCA1 pyramidal neurons were similar at age 3 months in WTs and KOs. However, by 6 months there were significant reductions in apical and basal dendritic length, dendrite complexity, and spine density in KO versus WT mice that were maintained through ages 9 and 12 months. Immunostaining for protein adducts of the lipid peroxidation product 4-hydroxynonenal revealed significant increases in staining in dCA1 (but not ventral CA1) by 3 months, increasing through 12 months., Conclusion: This specific and progressive increase in dCA1 oxidative damage preceded detectable synaptic trimming in KO mice, in keeping with studies showing that lesions to dorsal hippocampus primarily impair cognitive memory.

The Na + /K + -ATPase is a transmembrane ion pump that has a critical homeostatic role within every mammalian cell; however, it is vulnerable to the effects of increased oxidative stress. Understanding how expression of this transporter is influenced by oxidative stress may yield insight into its role in the pathophysiology of neurological and neuropsychiatric diseases. In this study we investigated whether increased oxidative stress could influence Na + /K + -ATPase expression in various brain regions of mice. We utilized two different models of oxidative stress: a behavioural chronic unpredictable stress protocol and the Aldh2 -/- mouse model of oxidative stress-based and age-related cognitive impairment. We identified distinct regional baseline mRNA and protein expression patterns of the Na + /K + -ATPase α1 and α3 isoforms within the neocortex, hippocampus, and brainstem of wildtype mice. Consistent with previous studies, there was a higher proportion of α3 expression relative to α1 in the brainstem versus neocortex, but a higher proportion of α1 expression relative to α3 in the neocortex versus the brainstem. The hippocampus had similar expression levels of both α1 and α3. Despite increased staining for oxidative stress in higher brain, no differences in α1 or α3 expression were noted in Aldh2 -/- mice versus wildtype, or in mice exposed to a 28-day chronic unpredictable stress protocol. In both models of oxidative stress, gene and protein expression of Na + /K + -ATPase α1 and α3 isoforms within the higher and lower brain was remarkably stable. Thus, Na + /K + -ATPase function previously reported as altered by oxidative stress is not through induced changes in the expression of pump isoforms., (Copyright © 2020 IBRO. Published by Elsevier Ltd. All rights reserved.)

Background: Dysregulated signaling in neurons and astrocytes participates in pathophysiological alterations seen in the Alzheimer's disease brain, including increases in amyloid-β, hyperphosphorylated tau, inflammation, calcium dysregulation, and oxidative stress. These are often noted prior to the development of behavioral, cognitive, and non-cognitive deficits. However, the extent to which these pathological changes function together or independently is unclear., Objective: Little is known about the temporal relationship between calcium dysregulation and oxidative stress, as some reports suggest that dysregulated calcium promotes increased formation of reactive oxygen species, while others support the opposite. Prior work has quantified several key outcome measures associated with oxidative stress in aldehyde dehydrogenase 2 knockout (Aldh2-/-) mice, a non-transgenic model of sporadic Alzheimer's disease., Methods: Here, we tested the hypothesis that early oxidative stress can promote calcium dysregulation across aging by measuring calcium-dependent processes using electrophysiological and imaging methods and focusing on the afterhyperpolarization (AHP), synaptic activation, somatic calcium, and long-term potentiation in the Aldh2-/- mouse., Results: Our results show a significant age-related decrease in the AHP along with an increase in the slow AHP amplitude in Aldh2-/- animals. Measures of synaptic excitability were unaltered, although significant reductions in long-term potentiation maintenance were noted in the Aldh2-/- animals compared to wild-type., Conclusion: With so few changes in calcium and calcium-dependent processes in an animal model that shows significant increases in HNE adducts, Aβ, p-tau, and activated caspases across age, the current findings do not support a direct link between neuronal calcium dysregulation and uncontrolled oxidative stress.

The study of late-onset (sporadic) Alzheimer's disease (LOAD) has lacked animal models where impairments develop with aging. Oxidative stress promotes LOAD, so we have developed an oxidative stress-based model of age-related cognitive impairment based on gene deletion of aldehyde dehydrogenase 2 (ALDH2). This enzyme is important for the detoxification of endogenous aldehydes arising from lipid peroxidation. Compared to wildtype (WT) mice, the knockout (KO) mice exhibit a progressive decline in recognition and spatial memory and AD-like pathologies. Here we performed morphometric analyses in the dorsal and ventral hippocampal CA1 regions (dCA1 and vCA1) as well as in overlying primary sensory cortex to determine if altered neuronal structure can help account for the cognitive impairment in 12-month old KO mice. Dendritic morphology was quantitatively analyzed following Golgi-Cox staining using 9 WT mice (108 neurons) and 15 KO mice (180 neurons). Four pyramidal neurons were traced per mouse in each region, followed by branched structured analysis and Sholl analysis. Compared to WT controls, the morphology and complexity of dCA1 pyramidal neurons from KOs showed significant reductions in apical and basal dendritic length, dendrite intersections, ends, and nodes. As well, spine density along dorsal CA1 apical dendrites was significantly lower in KO versus WT. In contrast, pyramidal arborization in the vCA1 and primary sensory cortex were only minimally reduced in KO versus WT mice. These data suggest a region-specific vulnerability to oxidative stress-induced damage and/or a major and specific reduction in synaptic input to the pyramidal neurons of the dorsal hippocampus. This is in keeping with studies showing that lesions to the dorsal hippocampus impair primarily cognitive memory whereas ventral hippocampal lesions cause deficits in stress, emotion, and affect.

Whereas many studies have examined the properties of the compromised neocortex in the first several days following ischemia, there is less information regarding the initial 12 h poststroke. In this study we examined live mouse neocortical slices harvested immediately and 12 h after a 30-min middle cerebral artery occlusion (MCAo). We compared nonischemic and ischemic hemispheres with regard to the propensity for tissue swelling and for generating spreading depolarization (SD), as well as evoked synaptic responses and single pyramidal neuron electrophysiological properties. We observed spontaneous SD in 7% of slices on the nonstroked side and 25% in the stroked side following the 30-min MCAo. Spontaneous SD was rare in 12-h recovery slices. The region of the ischemic core and surround in slices was not susceptible to SD induced by oxygen and glucose deprivation. At the neuronal level, neocortical gray matter is surprisingly unaltered in brain slices harvested immediately poststroke. However, by 12 h, the fields of pyramidal and striatal neurons that comprise the infarcted core are electrophysiologically silent because the majority are morphologically devastated. Yet, there remains a subset of diffusely distributed "healthy" pyramidal neurons in the core at 12 h post-MCAo that persist for days poststroke. Their intact electrophysiology and dendritic morphology indicate a surprisingly selective resilience to stroke at the neuronal level. NEW & NOTEWORTHY It is generally accepted that the injured core region of the brain resulting from a focal stroke contains no functioning neurons. Our study shows that some neurons, although surrounded by devastated neighbors, can maintain their structure and electrical activity. This surprising finding raises the possibility of discovering how these neurons are protected to pinpoint new strategies for reducing stroke injury.

Background: A broad literature base exists for measuring medication adherence to monotherapeutic regimens, but publications are less extensive for measuring adherence to multiple medications., Objectives: To identify and characterize the multiple medication adherence (MMA) methods used in the literature., Methods: A literature search was conducted using PubMed, PsycINFO, the International Pharmaceutical Abstracts, the Cumulative Index to Nursing and Allied Health Literature and the Cochrane Library databases on methods used to measure MMA published between January 1973 and May 2015. A two-step screening process was used; all abstracts were screened by pairs of researchers independently, followed by a full-text review identifying the method for calculating MMA. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed to conduct this systematic review. For studies that met the eligibility criteria, general study and adherence-specific characteristics and the number and type of MMA measurement methods were summarized., Results: The 147 studies that were included originated from 32 countries, in 13 disease states. Of these studies, 26 used proportion of days covered, 23 used medication possession ratio, and 72 used self-reported questionnaires (e.g., the Morisky Scale) to assess MMA. About 50% of the studies included more than one method for measuring MMA, and different variations of medication possession ratio and proportion of days covered were used for measuring MMA., Conclusions: There appears to be no standardized method to measure MMA. With an increasing prevalence of polypharmacy, more efforts should be directed toward constructing robust measures suitable to evaluate adherence to complex regimens. Future research to understand the validity and reliability of MMA measures and their effects on objective clinical outcomes is also needed., (Copyright © 2019 ISPOR–The Professional Society for Health Economics and Outcomes Research. Published by Elsevier Inc. All rights reserved.)

This article offers a historical framework for understanding changes to human perceptions and efforts to manage invasive alien plants and weeds in South Africa from the mid-nineteenth century until the present. The article argues that South African legislation and policy for managing invasive alien plants and weeds has historically been limited because people have held contradictory values about plants, many private land owners have lacked resources and have not been compelled to follow government legislation and because policy has reflected the interests of a small group of farmers or scientific experts who have had limited influence on most private land owners and traditional land users. Successful control efforts often relied on technical expertise that was applied controversially or could be implemented on government land without extensive public consultation or social conflict. The creation of a national framework for invasive alien plants through the Working for Water Programme in 1995 and National Environmental Management of Biodiversity Act (no. 10) of 2004 (NEMBA) has increased public awareness, but the Programme and NEMBA remain limited by many of the same institutional and social constraints that experts and institutions faced in the past. In conclusion, the article draws on history to provide insights to contemporary challenges., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background Nitric oxide (NO) has been heavily implicated in migraine. Nitroglycerin is a prototypic NO-donor, and triggers migraine in humans. However, nitroglycerin also induces oxidative/nitrosative stress and is a source of peroxynitrite - factors previously linked with migraine etiology. Soluble guanylyl cyclase (sGC) is the high affinity NO receptor in the body, and the aim of this study was to identify the precise role of sGC in acute and chronic migraine. Methods We developed a novel brain-bioavailable sGC stimulator (VL-102), and tested its hyperalgesic properties in mice. We also determined the effect of VL-102 on c-fos and calcitonin gene related peptide (CGRP) immunoreactivity within the trigeminovascular complex. In addition, we also tested the known sGC inhibitor, ODQ, within the chronic nitroglycerin migraine model. Results VL-102-evoked acute and chronic mechanical cephalic and hind-paw allodynia in a dose-dependent manner, which was blocked by the migraine medications sumatriptan, propranolol, and topiramate. In addition, VL-102 also increased c-fos and CGRP expressing cells within the trigeminovascular complex. Importantly, ODQ completely inhibited acute and chronic hyperalgesia induced by nitroglycerin. ODQ also blocked hyperalgesia already established by chronic nitroglycerin, implicating this pathway in migraine chronicity. Conclusions These results indicate that nitroglycerin causes migraine-related pain through stimulation of the sGC pathway, and that super-activation of this receptor may be an important component for the maintenance of chronic migraine. This work opens the possibility for negative sGC modulators as novel migraine therapies.

Background: Health-related quality of life (HRQOL) and adherence to treatment are two often inter-related concepts that have implications for patient management and care. Tuberculosis (TB) and its treatment present a major public health concern in South Africa. The study aimed to evaluate the association between HRQOL and adherence in TB patients in South Africa. Methods: Four self-reported HRQOL and one self-reported adherence measures were used in an observational longitudinal multicentre study during 6-month standard TB treatment. These included the generic Short-Form 12 items (SF-12) and European Quality of Life 5 dimensions 5 levels (EQ-5D-5L), the disease-specific St. George's Respiratory Questionnaire (SGRQ) and the condition-specific Hospital Anxiety and Depression Scale (HADS) for HRQOL. Adherence was measured by the Morisky Medication Adherence Scale 8 items (MMAS-8). The relationship between both concepts was examined in 131 patients using Spearman's rho correlations, and linear regression models. Results: HRQOL improved over 6-month TB treatment, whereas adherence mean scores stayed constant with participants attaining a medium average level. Around 76% of patients reported to be high adherers and 24% were reporting a medium or low adherence. Associations between HRQOL and adherence were mainly weak. High adherence at treatment start was positively related to improvements in anxiety and depression after 6-month treatment. The overall improvement in pain and discomfort, and psychosocial health aspects over treatment time was positively, but weakly associated with adherence at 6 months of treatment. Conclusion: A positive relationship exists between adherence and HRQOL in TB in a South African setting, but this relationship was very weak, most likely because HRQOL is affected by a number of different factors and not limited to effects of adherence. Therefore, management of TB patients should, besides adequate drug treatment, address the specific mental and psychosocial needs.

Oxidative damage resulting from increased lipid peroxidation (LPO) is considered an important factor in the development of late onset/age-related Alzheimer's disease (AD). Deuterium-reinforced polyunsaturated fatty acids (D-PUFAs) are more resistant to the reactive oxygen species-initiated chain reaction of LPO than regular hydrogenated (H-) PUFAs. We investigated the effect of D-PUFA treatment on LPO and cognitive performance in aldehyde dehydrogenase 2 (Aldh2) null mice, an established model of oxidative stress-related cognitive impairment that exhibits AD-like pathologies. Mice were fed a Western-type diet containing either D- or H-PUFAs for 18 weeks. D-PUFA treatment markedly decreased cortex and hippocampus F 2 -isoprostanes by approximately 55% and prostaglandin F 2α by 20-25% as compared to H-PUFA treatment. D-PUFAs consistently improved performance in cognitive/memory tests, essentially resetting performance of the D-PUFA-fed Aldh2 -/- mice to that of wild-type mice fed a typical laboratory diet. D-PUFAs therefore represent a promising new strategy to broadly reduce rates of LPO, and combat cognitive decline in AD., (© 2017 Federation of European Biochemical Societies.)

Hippocampus oxidative stress is considered pathogenic in neurodegenerative diseases, such as Alzheimer disease (AD), and in neurodevelopmental disorders, such as Angelman syndrome (AS). Yet clinical benefits of antioxidant treatment for these diseases remain unclear because conventional imaging methods are unable to guide management of therapies in specific hippocampus subfields in vivo that underlie abnormal behavior. Excessive production of paramagnetic free radicals in nonhippocampus brain tissue can be measured in vivo as a greater-than-normal 1/ T 1 paradigm for bridging brain subfield oxidative stress and behavior in animal models and in human patients to better manage antioxidant therapy in devastating neurodegenerative and neurodevelopmental diseases.-Berkowitz, B. A., Lenning, J., Khetarpal, N., Tran, C., Wu, J. Y., Berri, A. M., Dernay, K., Haacke, E. M., Shafie-Khorassani, F., Podolsky, R. H., Gant, J. C., Maimaiti, S., Thibault, O., Murphy, G. G., Bennett, B. M., Roberts, R. in vivo paradigm for bridging brain subfield oxidative stress and behavior in animal models and in human patients to better manage antioxidant therapy in devastating neurodegenerative and neurodevelopmental diseases.-Berkowitz, B. A., Lenning, J., Khetarpal, N., Tran, C., Wu, J. Y., Berri, A. M., Dernay, K., Haacke, E. M., Shafie-Khorassani, F., Podolsky, R. H., Gant, J. C., Maimaiti, S., Thibault, O., Murphy, G. G., Bennett, B. M., Roberts, R. In vivo imaging of prodromal hippocampus CA1 subfield oxidative stress in models of Alzheimer disease and Angelman syndrome., (© FASEB.)

Background: Little is known about the humanistic burden of small cell lung cancer (SCLC), specifically the impact on health-related quality of life (HRQoL). The aim of this systematic literature review was to explore the impact of SCLC on HRQoL and the patient reported outcomes (PROs) used to capture this impact. Methods: We conducted a systematic search of Medline®, Embase, and PsycINFO, oncology organization websites and conference proceedings within the past 10 years. Articles reporting HRQoL outcomes of SCLC patients were selected. Results: Twenty-seven eligible publications were identified. Global or overall impact on HRQoL ( n = 21) was reported most often, with considerably fewer reporting individual domains that comprise HRQoL. Results indicated that HRQoL was negatively impacted in SCLC patients in comparison to the normal population in most domains. Overall, the domains measuring physical functioning and activities of daily living were most impacted. However, results on cognitive and emotional functioning were inconclusive. The impact on HRQoL may be least in both limited disease and extensive disease (ED) SCLC patients who have responded to treatment, and greatest in ED patients who were treatment naïve. The most frequently used PROs were the EORTC QLQ-C30 core cancer instruments, the lung cancer specific module the EORTC QLQ-LC13, LCSS, and EQ-5D. Conclusion: There exists a paucity of reporting on SCLC HRQoL outcomes. This extends to the reporting of domain level scores and by patient sub-group. Greater reporting at a granular level is recommended to allow for more robust conclusions to be made.

Background: Clinical failures singularly targeting amyloid-β pathology indicate a critical need for alternative Alzheimer's disease (AD) therapeutic strategies. The mixed pathology reported in a large population of AD patients demands a multifunctional drug approach. Since activation of cAMP response element binding protein (CREB) plays a crucial role in synaptic strengthening and memory formation, we retooled a clinical drug with known neuroprotective and anti-inflammatory activity to activate CREB, and validated this novel multifunctional drug, NMZ, in 4 different mouse models of AD., Results: NMZ was tested in three mouse models of familial AD and one model of sporadic AD. In 3 × Tg hippocampal slices, NMZ restored LTP. In vivo, memory was improved with NMZ in all animal models with robust cognitive deficits. NMZ treatment lowered neurotoxic forms of Aβ in both APP/PS1 and 3 × Tg transgenic mice while also restoring neuronal plasticity biomarkers in the 3 × Tg mice. In EFAD mice, incorporation of the major genetic AD risk factor, hAPOE4, did not mute the beneficial drug effects. In a novel sporadic mouse model that manifests AD-like pathology caused by accelerated oxidative stress in the absence of any familial AD mutation, oral administration of NMZ attenuated hallmark AD pathology and restored biomarkers of synaptic and neuronal function., Conclusions: The multifunctional approach, embodied by NMZ, was successful in mouse models of AD incorporating Aβ pathology (APP/PS1), tau pathology (3xTg), and APOE4, the major human genetic risk factor for AD (EFAD). The efficacy observed in a novel model of sporadic AD (Aldh2 (-/-) ) demonstrates that the therapeutic approach is not limited to rare, familial AD genetic mutations. The multifunctional drug, NMZ, was not designed directly to target Aβ and tau pathology; however, the attenuation of this hallmark pathology suggests the approach to be a highly promising, disease-modifying strategy for AD and mixed pathology dementia.

cAMP-response element-binding protein (CREB) plays a central role in various aspects of central nervous system (CNS) function, ranging from the developmental stages to neuronal plasticity and survival in adult brain. Activation of CREB plays a crucial role in learning and memory and is at the convergence of multiple intracellular signaling cascades including CAMKII and MAPK. This review focuses on the important functions of nitric oxide (NO) in activating CREB via the NO receptor, soluble guanylyl cyclase (sGC), and production of the second messenger, cGMP. The involvement of the NO/cGMP signaling pathway in synaptic plasticity suggests several avenues for therapeutic intervention, and targeting early synaptic degeneration could be an attractive approach for the development of novel disease-modifying approaches to treat cognition and memory dysfunction in neurodegenerative diseases.

Introduction: There is a lack of agreed and established guidelines for the treatment of acute exacerbations of idiopathic pulmonary fibrosis (AE-IPF). This reflects, in part, the limited evidence-base underpinning the management of AE-IPF. In the absence of high-quality evidence, the aim of this research was to develop a clinician-led consensus statement for the definition, diagnosis and treatment of AE-IPF., Methods: A literature review was conducted to obtain published material on the definition and treatment of AE-IPF. The results of this review were circulated to an online panel of clinicians for review. Statements were then shared with ten expert respiratory clinicians who regularly treat patients with IPF. A Delphi technique was then used to develop a consensus statement for the definition, diagnosis and treatment of AE-IPF. During the first round of review, clinicians rated the clarity of each statement, the extent to which the statement should be included and provided comments. In two subsequent rounds of review, clinicians were provided with the group median inclusion rating for each statement, and any revised wording of statements to aid clarity. Clinicians were asked to repeat the clarity and inclusion ratings for the revised statements., Results: The literature review, online panel discussion, and face-to-face meeting generated 65 statements covering the definition, diagnosis, and management of AE-IPF. Following three rounds of blind review, 90% of clinicians agreed 39 final statements. These final statements included a definition of AE-IPF, approach to diagnosis, and treatment options, specifically: supportive measures, use of anti-microbials, immunosuppressants, anti-coagulants, anti-fibrotic therapy, escalation, transplant management, and long-term management including discharge planning., Conclusion: This clinician-led consensus statement establishes the 'best practice' for the management and treatment of AE-IPF based on current knowledge, evidence, and available treatments.

Background: The study of late-onset/age-related Alzheimer's disease (AD)(sporadic AD, 95% of AD cases) has been hampered by a paucity of animal models. Oxidative stress is considered a causative factor in late onset/age-related AD, and aldehyde dehydrogenase 2 (ALDH2) is important for the catabolism of toxic aldehydes associated with oxidative stress. One such toxic aldehyde, the lipid peroxidation product 4-hydroxynonenal (HNE), accumulates in AD brain and is associated with AD pathology. Given this linkage, we hypothesized that in mice lacking ALDH2, there would be increases in HNE and the appearance of AD-like pathological changes., Results: Changes in relevant AD markers in Aldh2 (-/-) mice and their wildtype littermates were assessed over a 1 year period. Marked increases in HNE adducts arise in hippocampi from Aldh2 (-/-) mice, as well as age-related increases in amyloid-beta, p-tau, and activated caspases. Also observed were age-related decreases in pGSK3β, PSD95, synaptophysin, CREB and pCREB. Age-related memory deficits in the novel object recognition and Y maze tasks begin at 3.5-4 months and are maximal at 6.5-7 months. There was decreased performance in the Morris Water Maze task in 6 month old Aldh2 (-/-) mice. These mice exhibited endothelial dysfunction, increased amyloid-beta in cerebral microvessels, decreases in carbachol-induced pCREB and pERK formation in hippocampal slices, and brain atrophy. These AD-associated pathological changes are rarely observed as a constellation in current AD animal models., Conclusions: We believe that this new model of age-related cognitive impairment will provide new insight into the pathogenesis and molecular/cellular mechanisms driving neurodegenerative diseases of aging such as AD, and will prove useful for assessing the efficacy of therapeutic agents for improving memory and for slowing, preventing, or reversing AD progression.

Objective: A patient's preference may guide their behavior and influence their willingness to take medication or undergo treatment affecting outcomes, such as health-related quality of life, or survival. The importance of understanding patient preferences within oncology is unclear and few adherence studies exist compared with other therapeutic areas., Research Design and Methods: This study was designed to review the literature regarding patient preferences, adherence and their link to outcomes specifically in the oncology setting and to propose a theoretical model. An in-depth review was conducted, using Embase, MEDLINE and Cochrane Library databases to search for published data examining patient preference, adherence and oncology-specific outcomes, from 1982-2012. Articles were reviewed independently by two authors and rated for relevance and quality. Information from high-quality articles and discussion with oncology and patient preference experts were used to identify associations between important individual concepts as a basis for a theoretical model., Results: In total, 1362 abstracts were identified. After removal of duplicates and initial review, 1269 were excluded and 93 reviewed in detail. Of these publications, 18 were deemed 'high-quality' and used to develop the final model. Variables associated with patient preference, adherence and outcome were identified. External variables included communication, treatment and mode of administration; patient beliefs and values were identified as cognitive variables; and adherence was attributed as a behavioral variable. Relationships between patient preference, adherence and clinical outcomes were established. Adverse events had a strong relationship with adherence; patient beliefs and values were identified as having a moderating effect on adherence. Adherence behavior had a direct relationship to outcomes., Conclusions: Improving our understanding of patient preference may improve clinical outcomes in oncology patients. Although the proposed theoretical model is limited, it provides a basis to develop testable hypotheses for the relationships between patient preference, adherence and outcomes specific to oncology.

Tolerance to nitrates such as nitroglycerin (GTN) is associated with oxidative stress, inactivation of aldehyde dehydrogenase 2 (ALDH2), and decreased GTN-induced cGMP accumulation and vasodilation. We hypothesized that GTN-induced inactivation of ALDH2 results in increased 4-hydroxy-2-nonenal (HNE) adduct formation of key proteins involved in GTN bioactivation, and, consequently, an attenuated vasodilator response to GTN (i.e., tolerance). We used an in vivo GTN tolerance model, a cell culture model of nitrate action, and Aldh2(-/-) mice to assess whether GTN exposure resulted in HNE adduct formation, and whether exogenous HNE affected GTN-induced relaxation and cGMP accumulation. Immunoblot analysis indicated a marked increase in HNE adduct formation in GTN-tolerant porcine kidney epithelial cells (PK1) and in aortae from GTN-tolerant rats and untreated Aldh2(-/-) mice. Preincubation of PK1 cells with HNE resulted in a dose-dependent decrease in GTN-induced cGMP accumulation, and pretreatment of isolated rat aorta with HNE resulted in dose-dependent decreases in the vasodilator response to GTN, thus mimicking GTN-tolerance. Pretreatment of aortae from Aldh2(-/-) mice with 10 μM HNE resulted in a desensitized vasodilator response to GTN. In the in vivo rat tolerance model, changes in HNE adduct formation correlated well with the onset of GTN tolerance and tolerance reversal. Furthermore, coadministration of an HNE scavenger during the tolerance induction protocol completely prevented HNE adduct formation and GTN tolerance but did not prevent the inactivation of ALDH2. The data are consistent with a novel mechanism of GTN tolerance suggesting a primary role of HNE adduct formation in the development of GTN tolerance.

Selective estrogen receptor modulators (SERMs) are effective therapeutics that preserve favorable actions of estrogens on bone and act as antiestrogens in breast tissue, decreasing the risk of vertebral fractures and breast cancer, but their potential in neuroprotective and procognitive therapy is limited by: 1) an increased lifetime risk of thrombotic events; and 2) an attenuated response to estrogens with age, sometimes linked to endothelial nitric oxide synthase (eNOS) dysfunction. Herein, three 3(rd) generation SERMs with similar high affinity for estrogen receptors (ERα, ERβ) were studied: desmethylarzoxifene (DMA), FDMA, and a novel NO-donating SERM (NO-DMA). Neuroprotection was studied in primary rat neurons exposed to oxygen glucose deprivation; reversal of cholinergic cognitive deficit was studied in mice in a behavioral model of memory; long term potentiation (LTP), underlying cognition, was measured in hippocampal slices from older 3×Tg Alzheimer's transgenic mice; vasodilation was measured in rat aortic strips; and anticoagulant activity was compared. Pharmacologic blockade of GPR30 and NOS; denudation of endothelium; measurement of NO; and genetic knockout of eNOS were used to probe mechanism. Comparison of the three chemical probes indicates key roles for GPR30 and eNOS in mediating therapeutic activity. Procognitive, vasodilator and anticoagulant activities of DMA were found to be eNOS dependent, while neuroprotection and restoration of LTP were both shown to be dependent upon GPR30, a G-protein coupled receptor mediating estrogenic function. Finally, the observation that an NO-SERM shows enhanced vasodilation and anticoagulant activity, while retaining the positive attributes of SERMs even in the presence of NOS dysfunction, indicates a potential therapeutic approach without the increased risk of thrombotic events.

Scholars studying the globalization of Australian trees have previously emphasized the rapid natural propagation of Australian trees outside of their native habitats, believing their success to be a reversal of "ecological imperialism" from the "new world" to the "old world." This article argues that the expansion of Australian trees should not be viewed as a biological phenomenon, but as the result of a long-term attempt by powerful states and state-sponsored scientists to select and breed Australian species that could grow in a variety of climates and ecological conditions. Five non-biological factors largely determined the success of these attempts to grow Australian trees: the abundance or paucity of natural forests, state power, the amount of scientific research directed to planting Australian trees, the cost of labor, and the ability to utilize hardwood timbers and bark. This paper compares the use of Australian trees in Australia, India, and South Africa to demonstrate that biology was not the determining factor in the long-term success of many Australian genera and species.

Hyperplasia of smooth muscle contributes to the thickening of the intestinal wall that is characteristic of inflammation, but the mechanisms of growth control are unknown. Nitric oxide (NO) from enteric neurons expressing neuronal NO synthase (nNOS) might normally inhibit intestinal smooth muscle cell (ISMC) growth, and this was tested in vitro. In ISMC from the circular smooth muscle of the adult rat colon, chemical NO donors inhibited [(3)H]thymidine uptake in response to FCS, reducing this to baseline without toxicity. This effect was inhibited by the guanylyl cyclase inhibitor ODQ and potentiated by the phosphodiesterase-5 inhibitor zaprinast. Inhibition was mimicked by 8-bromo (8-Br)-cGMP, and ELISA measurements showed increased levels of cGMP but not cAMP in response to sodium nitroprusside. However, 8-Br-cAMP and cilostamide also showed inhibitory actions, suggesting an additional role for cAMP. Via a coculture model of ISMC and myenteric neurons, immunocytochemistry and image analysis showed that innervation reduced bromodeoxyuridine uptake by ISMC. Specific blockers of nNOS (7-NI, NAAN) significantly increased [(3)H]thymidine uptake in response to a standard stimulus, showing that nNOS activity normally inhibits ISMC growth. In vivo, nNOS axon number was reduced threefold by day 1 of trinitrobenzene sulfonic acid-induced rat colitis, preceding the hyperplasia of ISMC described earlier in this model. We conclude that NO can inhibit ISMC growth primarily via a cGMP-dependent mechanism. Functional evidence that NO derived from nNOS causes inhibition of ISMC growth in vitro predicts that the loss of nNOS expression in colitis contributes to ISMC hyperplasia in vivo.

Although glyceryl trinitrate (GTN) has been used in the treatment of angina for many years, details of its conversion to the proximal activator (presumed to be NO or an NO congener) of soluble guanylyl cyclase (sGC) are still unclear. We reported previously that purified microsomal glutathione transferase 1 (MGST1) mediates the denitration of GTN. In the current study, we investigated in intact cells whether this enzyme also converts GTN to species that activate sGC (mechanism-based biotransformation). We utilized LLC-PK1 cells, a cell line with an intact NO/sGC/cGMP system, and generated a stable cell line that overexpressed MGST1. MGST1 in the stably transfected cells was localized to the endoplasmic reticulum, and microsomes from these cells exhibited markedly increased GST activity. Although incubation of these cells with GTN resulted in a 3-4-fold increase in GTN biotransformation, attributed primarily to an increase in formation of the 1,3-glyceryl dinitrate metabolite, GTN-induced cGMP accumulation in cells overexpressing MGST1 was not different than that observed in wild type cells or in cells stably transfected with empty vector. To determine whether overexpression of NADPH cytochrome P450 reductase might act in concert with MGST1 to generate activators of sGC, we assessed GTN-induced cGMP accumulation in MGST1-overexpressing cells that had been transiently transfected with CPR. In this case, GTN-induced cGMP accumulation was also not different than that observed in wild type cells. We conclude that although MGST1 mediates the biotransformation of GTN in intact cells, this biotransformation does not contribute to the formation of activators of sGC.

It is generally accepted that nitric oxide (NO) donors, such as sodium nitroprusside (SNP), or phosphodiesterase 5 (PDE5) inhibitors, including sildenafil, each impact human platelet function. Although a strong correlation exists between the actions of NO donors in platelets and their impact on cGMP, agents such as sildenafil act without increasing global intra-platelet cGMP levels. This study was undertaken to identify how PDE5 inhibitors might act without increasing cGMP. Our data identify PDE5 as an integral component of a protein kinase G1beta (PKG1beta)-containing signaling complex, reported previously to coordinate cGMP-mediated inhibition of inositol-1, 4, 5-trisphosphate receptor type 1 (IP(3)R1)-mediated Ca(2+)-release. PKG1beta and PDE5 did not interact in subcellular fractions devoid of IP(3)R1 and were not recruited to IP(3)R1-enriched membranes in response to cGMP-elevating agents. Activation of platelet PKG promoted phosphorylation and activation of the PDE5 fraction tethered to the IP(3)R1-PKG complex, an effect not observed for the nontethered PDE5. Based on these findings, we elaborate a model in which PKG selectively activates PDE5 within a defined microdomain in platelets and propose that this mechanism allows spatial and temporal regulation of cGMP signaling in these cells. Recent reports indicate that sildenafil might prove useful in limiting in-stent thrombosis and the thrombotic events associated with the acute coronary syndromes (ACS), situations poorly regulated with currently available therapeutics. We submit that our findings may define a molecular mechanism by which PDE5 inhibition can differentially impact selected cellular functions of platelets, and perhaps of other cell types.

Objective: Patients with chronic heart failure (CHF) often require higher doses of nitroglycerin (glyceryl trinitrate, GTN) than patients with normal cardiac function to achieve a given haemodynamic goal. Two pathways leading to biotransformation of GTN have been characterized; a high-affinity pathway operative in nanomolar concentration ranges yielding predominantly 1,2-glyceryl dinitrate (1,2-GDN), and a low-affinity pathway operative at higher, micromolar concentrations of GTN associated with a greater proportion of 1,3-GDN formation. We tested the hypothesis that, at a given GTN-induced blood pressure reduction, the CHF group would present with: (i) higher concentrations of GTN; and (ii) decreased ratios of 1,2-GDN/GTN and 1,2-GDN/1,3-GDN compared with healthy subjects (HS)., Methods: Twelve patients with CHF (left ventricular ejection fraction 20 +/- 5%, NYHA III) and nine HS were investigated during a right cardiac catheterization. GTN was titrated intravenously until mean arterial blood pressure (MAP) was reduced by 15%., Results: At arterial GTN concentrations of 27.2 [10.0-57.8] nmol l(-1) in CHF and 2.8 [2.5-3.5] nmol l(-1) in HS [median (quartile range), P<0.05 between groups], MAP and mean capillary wedge pressures were reduced similarly in both groups (approx. 15% and 65%, respectively, P = NS between groups). The ratios of 1,2-GDN/GTN and 1,2-GDN/1,3-GDN were lower in CHF (0.86 [0.28-1.58] and 5.8 [5.6-6.3]) compared with HS [1.91 (1.54-2.23) and 7.6 (7.2-10.2), P<0.05], with a negative correlation between the 1,2-GDN/1,3-GDN ratio and the arterial GTN concentrations in the CHF patients (R = -0.8, P<0.05)., Conclusion: Patients with CHF have attenuated GTN responsiveness and decreased relative formation of 1,2-GDN in comparison with HS, indicating an altered biotransformation of GTN.

Purpose: Hypoxia contributes to drug resistance in solid cancers, and studies have revealed that low concentrations of nitric oxide (NO) mimetics attenuate hypoxia-induced drug resistance in tumor cells in vitro. Classic NO signaling involves activation of soluble guanylyl cyclase, generation of cyclic GMP (cGMP), and activation of cGMP-dependent protein kinase. Here, we determined whether chemosensitization by NO mimetics requires cGMP-dependent signaling and whether low concentrations of NO mimetics can chemosensitize tumors in vivo., Experimental Design: Survival of human prostate and breast cancer cells was assessed by clonogenic assays following exposure to chemotherapeutic agents. The effect of NO mimetics on tumor chemosensitivity in vivo was determined using a mouse xenograft model of human prostate cancer. Drug efflux in vitro was assessed by measuring intracellular doxorubicin-associated fluorescence., Results: Low concentrations of the NO mimetics glyceryl trinitrate (GTN) and isosorbide dinitrate attenuated hypoxia-induced resistance to doxorubicin and paclitaxel. Similar to hypoxia-induced drug resistance, inhibition of various components of the NO signaling pathway increased resistance to doxorubicin, whereas activation of the pathway with 8-bromo-cGMP attenuated hypoxia-induced resistance. Drug efflux was unaffected by hypoxia and inhibitors of drug efflux did not significantly attenuate hypoxia-induced chemoresistance. Compared with mice treated with doxorubicin alone, tumor growth was decreased in mice treated with doxorubicin and a transdermal GTN patch. The presence of GTN and GTN metabolites in plasma samples was confirmed by gas chromatography., Conclusion: Tumor hypoxia induces resistance to anticancer drugs by interfering with endogenous NO signaling and reactivation of NO signaling represents a novel approach to enhance chemotherapy.

Many conditions adversely affecting learning, memory, and cognition are associated with reductions in forebrain acetylcholine (ACh), most notably aging and Alzheimer's disease. In the current study, we demonstrate that bilateral depletion of neocortical and hippocampal ACh in rats produces deficits in a spatial learning task and in a recently described, delayed visual matching-to-sample task. Oral administration of the novel nitrate, GT1061 (4-methyl-5-(2-nitroxyethyl) thiazole HCl), and the acetylcholinesterase inhibitor, donepezil, reversed the cognitive deficits in both memory tasks in a dose-dependent manner. GT1061 was superior in the delayed matching-to-sample task. GT1061 was absorbed rapidly after oral administration, crossed the blood brain barrier, and achieved brain concentrations that were slightly higher than those found in plasma. The activity of GT1061 was NO mimetic: soluble guanylyl cyclase (sGC) was activated, but selectivity was observed for sGC in the hippocampus relative to the vasculature; and hippocampal levels of phosphorylated ERK1/2, which is a postulated intermediary in the formation of long-term memory, were increased. The beneficial effect on visual and spatial memory task performance supports the concept that stimulating the NO/sGC/cGMP signal transduction system can provide new, effective treatments for cognitive disorders. This approach may be superior to that of current drugs that attempt only to salvage the residual function of damaged cholinergic neurons.

Although the biotransformation of organic nitrates by the cytosolic glutathione S-transferases (GSTs) is well known, the relative contribution of the microsomal GST (MGST1) to nitrate biotransformation has not been described. We therefore compared the denitration of glyceryl trinitrate (GTN) by purified rat liver MGST1 and cytosolic GSTs. Both MGST1 and cytosolic GSTs catalyzed the denitration of GTN, but the activity of MGST1 toward GTN was 2- to 3-fold higher. To mimic oxidative/nitrosative stress in vitro, we treated enzyme preparations with hydrogen peroxide, S-nitrosoglutathione, and peroxynitrite. Both oxidants and nitrating reagents increased the activity of MGST1 toward the GST substrate, 1-chloro-2,4-dinitrobenzene (CDNB) whereas these treatments inhibited GTN denitration by MGST1. Alkylation of the sole cysteine residue of MGST1 by N-ethylmaleimide markedly increased enzyme activity with CDNB as substrate but decreased the rate of GTN denitration. In aortic microsomes from GTN-tolerant animals, there was a decreased abundance of MGST1 dimers and trimers. In hepatic microsomes from GTN-tolerant animals, GTN biotransformation was unaltered whereas the rate of CDNB conjugation was doubled, suggesting that chronic GTN exposure causes structural modifications to the enzyme, resulting in increased activity to certain substrates. Collectively, these data indicate that MGST1 contributes significantly to the biotransformation of GTN and that chemical modification of the microsomal enzyme has differential effects on the catalytic activity toward different substrates.

Endothelial progenitor cells (EPCs) participate in angiogenesis and the response to chronic ischemia. Risk factors and cardiovascular disease attenuate EPC number, function, and survival. Continuous therapy with nitroglycerin (glyceryl trinitrate; GTN) is associated with increased vascular oxidative stress, leading to nitrate tolerance and endothelial dysfunction. Thus, GTN therapy may also affect EPCs. The purpose of this study was to determine whether continuous exposure to GTN in vivo or during ex vivo expansion affects the circulating number and functional characteristics of human EPCs. To determine the effects of continuous in vivo GTN exposure, EPCs isolated from 28 healthy males before and after receiving 0.6 mg/h GTN (n=17) or no treatment (n=11) for 1 week were expanded for 6 days and compared. To determine the effects of continuous ex vivo GTN exposure, EPCs isolated before randomization were expanded for 6 days in medium supplemented with 100 nM, 300 nM, or 1 microM GTN. EPCs expanded without GTN served as controls (n=10). In vivo, GTN exposure significantly increased the percentage of circulating cells expressing the EPC marker CD34 and increased the susceptibility of expanded EPCs to apoptosis but had no impact on the phenotypic differentiation or migration of EPCs. Ex vivo, GTN exposure increased apoptosis while decreasing phenotypic differentiation, migration, and mitochondrial dehydrogenase activity of EPCs, compared with EPCs expanded in the absence of GTN. Taken together, these results suggest that continuous GTN therapy might impair EPC-mediated processes, an effect that could be detrimental in the setting of ischemic cardiovascular disease.

NO is an important messenger molecule in the brain, playing an important role in learning and memory, in particular via the ERK/CREB signaling pathway. NO is also a neuroprotective agent; multiple mechanisms having been demonstrated that can contribute to cell survival as levels of antioxidants and trophic factors are reduced with aging. Small molecules that mimic the biological activity of NO, including NO donors, may thus ameliorate cognition and provide neuroprotection. Several lines of evidence have linked the neurodegeneration and dementia characteristic of Alzheimer's disease with the action of beta-amyloid protein at the alpha7-nicotinic acetylcholine receptor. The interplay of Abeta with alpha7-nicotinic ACh receptors operating via the ERK signaling cascade links the amyloid cascade and the cholinergic hypothesis in pathways that impact synaptic plasticity and memory. This interplay also provides linkages to disruption of NO/cGMP signaling in AD, and in addition, recent direct evidence has been found demonstrating that Abeta downregulates the NO/cGMP/CREB pathway. Activation of soluble guanylyl cyclase elevating cGMP in the brain represents the central element of a therapeutic approach to the treatment of AD and other neurodegenerative diseases, furthermore, evidence suggests that NO may display cGMP-independent activity and may operate via multiple biochemical signaling pathways to ensure the survival of neurons subjected to stress. GT 1061 is an NO chimera, an NO mimetic compound that contains an ancillary, synergistic pharmacophore, currently in clinical trials for Alzheimer's. NO chimeras and hybrid nitrates hold promise as therapeutics for AD with multiple sites of action.

An important component of the antianginal efficacy of glyceryl trinitrate (GTN) is attributable to its selective venodilator effect, resulting in decreased cardiac preload and myocardial oxygen demand. Tolerance to nitrates occurs during chronic exposure, and the current study assessed whether this was due to increased phosphodiesterase (PDE) activity in the venous circulation. Tolerance was induced in rats by continuous exposure to 0.4 mg/h GTN for 48 h. Tension recordings of isolated femoral artery and vein indicated that tolerance was more pronounced in femoral vein. 4-[[3,4-(Methylenedioxy)benzyl]amino]-6-chloroquinazoline (MBCQ), a selective PDE5 inhibitor, significantly decreased the EC(50) values for GTN-induced relaxation in both tolerant and nontolerant tissues, but with the greatest relative shift occurring in tolerant veins. MBCQ also increased the vasodilator potency of 1,1-diethyl-2-hydroxy-2-nitrosohydrazine (DEA/NO), a nitric oxide donor; however, cross-tolerance between DEA/NO and GTN was not observed. A significant increase in cGMP PDE activity was observed in tolerant femoral vein, whereas PDE activity was unchanged in femoral artery. Conscious rats treated with hexamethonium (30 mg/kg) to induce ganglionic blockade exhibited blunted central venous pressure (CVP) and mean arterial pressure (MAP) responses to bolus i.v. doses of GTN in GTN-tolerant animals. The cGMP PDE inhibitor zaprinast (1 mg/kg) selectively reversed the blunted CVP response to GTN in tolerant animals but had no effect on the CVP response to GTN in nontolerant animals or on the MAP response in either group. These results suggest that increased PDE5 activity in the venous circulation contributes to the altered hemodynamic response to GTN following chronic GTN exposure.

There is increasing evidence that protein function can be modified by nitration of tyrosine residue(s), a reaction catalyzed by proteins with peroxidase activity, or that occurs by interaction with peroxynitrite, a highly reactive oxidant formed by the reaction of nitric oxide with superoxide. Although there are numerous reports describing loss of function after treatment of proteins with peroxynitrite, we recently demonstrated that the microsomal glutathione S-transferase 1 is activated rather than inactivated by peroxynitrite and suggested that this could be attributed to nitration of tyrosine residues rather than to other effects of peroxynitrite. In this report, the nitrated tyrosine residues of peroxynitrite-treated microsomal glutathione S-transferase 1 were characterized by mass spectrometry and their functional significance determined. Of the seven tyrosine residues present in the protein, only those at positions 92 and 153 were nitrated after treatment with peroxynitrite. Three mutants (Y92F, Y153F, and Y92F, Y153F) were created using site-directed mutagenesis and expressed in LLC-PK1 cells. Treatment of the microsomal fractions of these cells with peroxynitrite resulted in an approximately 2-fold increase in enzyme activity in cells expressing the wild type microsomal glutathione S-transferase 1 or the Y153F mutant, whereas the enzyme activity of Y92F and double site mutant was unaffected. These results indicate that activation of microsomal glutathione S-transferase 1 by peroxynitrite is mediated by nitration of tyrosine residue 92 and represents one of the few examples in which a gain in function has been associated with nitration of a specific tyrosine residue.

It is hypothesized that chronic prenatal ethanol exposure (CPEE), via maternal ethanol administration, increases mitochondrial-directed apoptosis in the hippocampus of the term fetus that precedes loss of hippocampal CA1 pyramidal cells. To test this hypothesis, timed pregnant guinea pigs received chronic oral administration of: 4 g ethanol/kg maternal body weight/day, isocaloric-sucrose/pair-feeding or water throughout gestation. At gestational day 65 (term fetus) and postnatal day 0 (neonate), individual offspring were euthanized, and the brain was excised and dissected. CPEE, compared with the isocaloric-sucrose/pair-fed and water control groups, decreased the brain weight of the term fetus and neonate. CPEE did not alter the density of CA1 pyramidal cells in the hippocampus of the term fetus and neonate. In the term fetus, CPEE increased cytochrome c content in the cytosolic fraction of the hippocampus, altered the mitochondrial localization of cytochrome c in cells of the dorsal hippocampus, and increased the percentage of cells in the dorsal hippocampus containing activated caspase-3 and cleaved poly(ADP-ribose) polymerase. The data indicate that CPEE increases neuroapoptosis in the hippocampus of term fetus, which appears to occur via an intrinsic, mitochondrial-directed mechanism initiated by leakage of pro-apoptotic cytochrome c from mitochondria into the cytoplasm.

Nitric oxide is multifunctional messenger molecule in the brain, playing important roles including in learning and memory and in regulating the expression of trophic factors that may be reduced with aging. Small molecules that mimic the biological activity of NO, NO mimetics, will bypass cholinergic receptor activation and are anticipated to provide multiple pathways of treating and circumventing dementia in Alzheimer's disease. Activation of soluble guanylyl cyclase and cGMP formation in the brain represents one element of effective neuroprotective pathways mediated by NO. Substantial evidence suggests that NO mimetics may display cGMP-dependent and cGMP-independent activity and may operate via multiple biochemical signaling pathways, both to ensure the survival of neurons subjected to stress and also to provide cognition-enabling pathways to circumvent dementia. GT 1061 is an NO mimetic compound currently in clinical trials for Alzheimer's. A survey of current research indicates that NO mimetics will provide a combined neuroprotective and cognition-enabling approach to anti-neurodegenerative therapy.

Activation of endothelial proteinase-activated receptor 2 (PAR-2) relaxes vascular smooth muscle (VSM) and causes hypotension by nitric oxide (NO)-prostanoid-dependent and -independent mechanisms. We investigated whether endothelium-dependent hyperpolarization of VSM was the mechanism whereby resistance caliber arteries vasodilated independently of NO. VSM membrane potentials and isometric tension were measured concurrently to correlate the electrophysiological and mechanical changes in murine small caliber mesenteric arteries. In uncontracted arteries, the PAR-2 agonist, SLIGRL-NH2 (0.1 to 10 micromol/L), hyperpolarized the VSM membrane potential only in endothelium-intact arterial preparations. This response was unaltered by treatment of arteries with inhibitors of NO synthases (L-NAME), soluble guanylyl cyclase (ODQ), and cyclooxygenases (indomethacin). L-NAME, ODQ, and indomethacin also failed to inhibit SLIGRL-NH2-induced hyperpolarization and of cirazoline-contracted mesenteric arteries. However, in blood vessels that were depolarized and contracted with 30 mmol/L KCl, the effects of the SLIGRL-NH2 on membrane potential and tension were not observed. SLIGRL-NH2-induced hyperpolarization and relaxation was inhibited completely by the combination of apamin plus charybdotoxin, but only partially inhibited after treatment with the combination of barium plus ouabain, suggesting an important role for SKCa and IKCa channels and a lesser role for Kir channels and Na+/K+ ATPases in the hyperpolarization response. We concluded that activation of endothelial PAR-2 hyperpolarized the vascular smooth muscle (VSM) cells of small caliber arteries, without requiring the activation of NO synthases, cyclooxygenases, or soluble guanylyl cyclase. Indeed, this hyperpolarization may be a primary mechanism for PAR-2-induced hypotension in vivo.

GT 1061 is a novel therapeutic agent that is in Phase 1 clinical studies for Alzheimer's disease. GT 1061 is one of a family of novel nitrates that have demonstrated neuroprotective properties and cognition- and memory-enhancing properties in animal models. The prototype of this family, GT 715, has been reported effectively to dissociate the neuromodulatory and the systemic hypotensive effects of nitrates, the latter seriously limiting the therapeutic use of classical nitrates. Further data on the novel nitrates, GT 715 and GT 061, are presented in (a) the malonate-lesion rat model of excitotoxic neurodegeneration, and (b) the reversal of a scopolamine-induced cognition deficit in the Morris water task which tests spatial memory. These data exemplify and reinforce the combined neuroprotective and cognition enhancing properties observed in this family of NO mimetic therapeutic agents. NO mimetics, that mimic the biological activity of NO, will bypass cholinergic receptor activation and are anticipated to provide multiple pathways of treating and circumventing dementia. NO mimetic activation of soluble guanylyl cyclase and cGMP formation in the brain represents one element of an effective neuroprotective strategy. Substantial evidence suggests that NO mimetics may display cGMP-dependent and cGMP-independent activity and may operate via multiple biochemical signaling pathways, both to ensure the survival of neurons subjected to stress and also to provide cognition-enabling pathways to circumvent dementia, providing a combined neuroprotective and cognition-enabling approach to anti-neurodegenerative therapy.

Nitroglycerine has been used clinically in the treatment of angina for 130 years, yet important details on the mechanism of action, biotransformation, and the associated phenomenon of nitrate tolerance remain unanswered. The biological activity of organic nitrates can be said to be nitric oxide mimetic, leading to recent, exciting progress in realizing the therapeutic potential of nitrates. Unequivocally, nitroglycerine and most other organic nitrates, including NO-NSAIDs, do not behave as NO donors in the most fundamental action: in vitro activation of sGC to produce cGMP. The question as to whether the biological activity of nitrates results primarily or exclusively from NO donation will not be satisfactorily answered until the location, the apparatus, and the mechanism of reduction of nitrates to NO are defined. Similarly, the therapeutic potential of nitrates will not be unlocked until this knowledge is attained. Aspects of the therapeutic and biological activity of nitrates are reviewed in the context of the chemistry of nitrates and the elusive efficient 3e- reduction required to generate NO.