RESUMO
Background: Health sciences libraries in medical schools, academic health centers, health care networks, and hospitals have established institutional repositories (IRs) to showcase their research achievements, increase visibility, expand the reach of institutional scholarship, and disseminate unique content. Newer roles for IRs include publishing open access journals, tracking researcher productivity, and serving as repositories for data sharing. Many repository managers oversee their IR with limited assistance from others at their institution. Therefore, IR practitioners find it valuable to network and learn from colleagues at other institutions. Case Presentation: This case report describes the genesis and implementation of a new initiative specifically designed for a health sciences audience: the Medical Institutional Repositories in Libraries (MIRL) Symposium. Six medical librarians from hospitals and academic institutions in the U.S. organized the inaugural symposium held virtually in November 2021. The goal was to fill a perceived gap in conference programming for IR practitioners in health settings. Themes of the 2021 and subsequent 2022 symposium included IR management, increasing readership and engagement, and platform migration. Post-symposium surveys were completed by 73/238 attendees (31%) in 2021 and by 62/180 (34%) in 2022. Feedback was overwhelmingly positive. Discussion: Participant responses in post-symposium surveys rated MIRL highly. The MIRL planning group intends to continue the symposium and hopes MIRL will steadily evolve, build community among IR practitioners in the health sciences, and expand the conversation around best practices for digital archiving of institutional content. The implementation design of MIRL serves as a blueprint for collaboratively bringing together a professional community of practice.
Assuntos
Bibliotecas Médicas , Editoração , Humanos , Faculdades de Medicina , Comunicação , Atenção à SaúdeRESUMO
OBJECTIVE: This study uses survey research methods to gain a deeper understanding of the institutional repository (IR) landscape in medical schools and academic health centers. METHODS: Members of the Association of Academic Health Sciences Libraries (AAHSL) were surveyed about their IRs. The authors used a mixed-methods approach of a survey and qualitative content analysis to identify common themes. RESULTS: Survey results indicate that a large majority of responding medical schools and academic health centers have or are implementing an IR (35 out of 50, 70%). Of these, 60% (21 institutions) participate in an institution-wide IR rather than administer their own repositories. Much of the archived content is grey literature that has not already been published, but the percentage of original content varies greatly among institutions. The majority (57.1%) of respondent institutions are not considering an open access policy or mandate. Most institutions (71.4%) reported that repository staff are depositing materials on behalf of users. DSpace and bepress Digital Commons are the most popular repository platforms in this community. The planned enhancements that were most frequently reported were implementing a discovery layer and ORCID integration. The majority of respondents (54.3%) do not plan to migrate to a different platform in the foreseeable future. Analysis of respondent comments identified the following themes: integration, redundancy, and reporting; alternatives and exploration; uniqueness; participation; and funding and operations. CONCLUSIONS: The study results capture a view of the IR landscape in medical schools and academic health centers and help readers understand what services their peers have in place as well as their plans for future developments.
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Centros Médicos Acadêmicos/organização & administração , Armazenamento e Recuperação da Informação/estatística & dados numéricos , Bibliotecas Médicas/organização & administração , Humanos , Faculdades de Medicina/organização & administraçãoRESUMO
Objective: The paper provides a review of current practices related to evaluation support services reported by seven biomedical and research libraries. Methods: A group of seven libraries from the United States and Canada described their experiences with establishing evaluation support services at their libraries. A questionnaire was distributed among the libraries to elicit information as to program development, service and staffing models, campus partnerships, training, products such as tools and reports, and resources used for evaluation support services. The libraries also reported interesting projects, lessons learned, and future plans. Results: The seven libraries profiled in this paper report a variety of service models in providing evaluation support services to meet the needs of campus stakeholders. The service models range from research center cores, partnerships with research groups, and library programs with staff dedicated to evaluation support services. A variety of products and services were described such as an automated tool to develop rank-based metrics, consultation on appropriate metrics to use for evaluation, customized publication and citation reports, resource guides, classes and training, and others. Implementing these services has allowed the libraries to expand their roles on campus and to contribute more directly to the research missions of their institutions. Conclusions: Libraries can leverage a variety of evaluation support services as an opportunity to successfully meet an array of challenges confronting the biomedical research community, including robust efforts to report and demonstrate tangible and meaningful outcomes of biomedical research and clinical care. These services represent a transformative direction that can be emulated by other biomedical and research libraries.
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Pesquisa Biomédica/organização & administração , Comunicação Interdisciplinar , Bibliotecas Médicas/organização & administração , Serviços Técnicos de Biblioteca/organização & administração , Canadá , Humanos , Bibliotecários , Serviços de Biblioteca/organização & administração , Levantamentos de Bibliotecas , Estados UnidosRESUMO
Exposure to hypoxia elicits an increase in minute ventilation that diminishes during continued exposure (roll-off). Brainstem N-methyl-D-aspartate receptors (NMDARs) and neuronal nitric oxide synthase (nNOS) contribute to the initial hypoxia-induced increases in minute ventilation. Roll-off is regulated by platelet-derived growth factor receptor-ß (PDGFR-ß) and S-nitrosoglutathione (GSNO) reductase (GSNOR). S-nitrosylation inhibits activities of NMDAR and nNOS, but enhances GSNOR activity. The importance of S-nitrosylation in the hypoxic ventilatory response is unknown. This study confirms that ventilatory roll-off is virtually absent in female GSNOR(+/-) and GSNO(-/-) mice, and evaluated the location of GSNOR in female mouse brainstem, and temporal changes in GSNOR activity, protein expression, and S-nitrosylation status of GSNOR, NMDAR (1, 2A, 2B), nNOS, and PDGFR-ß during hypoxic challenge. GSNOR-positive neurons were present throughout the brainstem, including the nucleus tractus solitarius. Protein abundances for GSNOR, nNOS, all NMDAR subunits and PDGFR-ß were not altered by hypoxia. GSNOR activity and S-nitrosylation status temporally increased with hypoxia. In addition, nNOS S-nitrosylation increased with 3 and 15 minutes of hypoxia. Changes in NMDAR S-nitrosylation were detected in NMDAR 2B at 15 minutes of hypoxia. No hypoxia-induced changes in PDGFR-ß S-nitrosylation were detected. However, PDGFR-ß phosphorylation increased in the brainstems of wild-type mice during hypoxic exposure (consistent with roll-off), whereas it did not rise in GSNOR(+/-) mice (consistent with lack of roll-off). These data suggest that: (1) S-nitrosylation events regulate hypoxic ventilatory response; (2) increases in S-nitrosylation of NMDAR 2B, nNOS, and GSNOR may contribute to ventilatory roll-off; and (3) GSNOR regulates PDGFR-ß phosphorylation.
Assuntos
Tronco Encefálico/metabolismo , Hipóxia/metabolismo , Neurônios/metabolismo , Processamento de Proteína Pós-Traducional , S-Nitrosoglutationa/metabolismo , Álcool Desidrogenase , Animais , Tronco Encefálico/patologia , Feminino , Glutationa Redutase/genética , Glutationa Redutase/metabolismo , Hipóxia/genética , Hipóxia/patologia , Camundongos , Camundongos Knockout , Neurônios/patologia , Óxido Nítrico Sintase Tipo I/genética , Óxido Nítrico Sintase Tipo I/metabolismo , Fosforilação/genética , Receptor beta de Fator de Crescimento Derivado de Plaquetas/genética , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Receptores de N-Metil-D-Aspartato/genética , Receptores de N-Metil-D-Aspartato/metabolismoRESUMO
S-Nitrosoglutathione is an endogenous airway smooth muscle relaxant. Increased airway S-nitrosoglutathione breakdown occurs in some asthma patients. We asked whether patients with increased airway catabolism of this molecule had clinical features that distinguished them from other asthma patients. We measured S-nitrosoglutathione reductase expression and activity in bronchoscopy samples taken from 66 subjects in the Severe Asthma Research Program. We also analysed phenotype and genotype data taken from the program as a whole. Airway S-nitrosoglutathione reductase activity was increased in asthma patients (p=0.032). However, only a subpopulation was affected and this subpopulation was not defined by a "severe asthma" diagnosis. Subjects with increased activity were younger, had higher IgE and an earlier onset of symptoms. Consistent with a link between S-nitrosoglutathione biochemistry and atopy: 1) interleukin 13 increased S-nitrosoglutathione reductase expression and 2) subjects with an S-nitrosoglutathione reductase single nucleotide polymorphism previously associated with asthma had higher IgE than those without this single nucleotide polymorphism. Expression was higher in airway epithelium than in smooth muscle and was increased in regions of the asthmatic lung with decreased airflow. An early-onset, allergic phenotype characterises the asthma population with increased S-nitrosoglutathione reductase activity.
Assuntos
Aldeído Oxirredutases/metabolismo , Asma/enzimologia , Brônquios/enzimologia , Regulação Enzimológica da Expressão Gênica , Adolescente , Adulto , Biópsia , Lavagem Broncoalveolar , Broncoscopia , Estudos de Casos e Controles , Células Cultivadas , Criança , Feminino , Genótipo , Humanos , Imunoglobulina E/sangue , Imuno-Histoquímica , Interleucina-13/metabolismo , Pulmão/enzimologia , Imageamento por Ressonância Magnética , Masculino , Metabolismo , Pessoa de Meia-Idade , Músculo Liso/enzimologia , Fenótipo , Polimorfismo de Nucleotídeo Único , Adulto JovemRESUMO
OBJECTIVE: Hemoglobin α (Hb α) and endothelial nitric oxide synthase (eNOS) form a macromolecular complex at myoendothelial junctions; the functional role of this interaction remains undefined. To test if coupling of eNOS and Hb α regulates nitric oxide signaling, vascular reactivity, and blood pressure using a mimetic peptide of Hb α to disrupt this interaction. APPROACH AND RESULTS: In silico modeling of Hb α and eNOS identified a conserved sequence of interaction. By mutating portions of Hb α, we identified a specific sequence that binds eNOS. A mimetic peptide of the Hb α sequence (Hb α X) was generated to disrupt this complex. Using in vitro binding assays with purified Hb α and eNOS and ex vivo proximity ligation assays on resistance arteries, we have demonstrated that Hb α X significantly decreased interaction between eNOS and Hb α. Fluorescein isothiocyanate labeling of Hb α X revealed localization to holes in the internal elastic lamina (ie, myoendothelial junctions). To test the functional effects of Hb α X, we measured cyclic guanosine monophosphate and vascular reactivity. Our results reveal augmented cyclic guanosine monophosphate production and altered vasoconstriction with Hb α X. To test the in vivo effects of these peptides on blood pressure, normotensive and hypertensive mice were injected with Hb α X, which caused a significant decrease in blood pressure; injection of Hb α X into eNOS(-/-) mice had no effect. CONCLUSIONS: These results identify a novel sequence on Hb α that is important for Hb α/eNOS complex formation and is critical for nitric oxide signaling at myoendothelial junctions.
Assuntos
Óxido Nítrico Sintase Tipo III/metabolismo , Óxido Nítrico/metabolismo , Vasoconstrição/fisiologia , alfa-Globinas/metabolismo , Sequência de Aminoácidos , Animais , Pressão Sanguínea/fisiologia , Células Cultivadas , Simulação por Computador , Sequência Conservada , Células Endoteliais/metabolismo , Humanos , Junções Intercelulares/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Modelos Moleculares , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Miócitos de Músculo Liso/metabolismo , Óxido Nítrico Sintase Tipo III/deficiência , Óxido Nítrico Sintase Tipo III/genética , Domínios e Motivos de Interação entre Proteínas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transdução de Sinais , Resistência Vascular/fisiologia , alfa-Globinas/química , alfa-Globinas/genéticaRESUMO
BACKGROUND: Collectrin is an orphan member of the renin-angiotensin system and is a homolog of angiotensin-converting enzyme 2, sharing ≈50% sequence identity. Unlike angiotensin-converting enzyme 2, collectrin lacks any catalytic domain. Collectrin has been shown to function as a chaperone of amino acid transporters. In rodents, the renal expression of collectrin is increased after subtotal nephrectomy and during high-salt feeding, raising the question of whether collectrin has any direct role in blood pressure regulation. METHODS AND RESULTS: Using a susceptible genetic background, we demonstrate that deletion of collectrin results in hypertension, exaggerated salt sensitivity, and impaired pressure natriuresis. Collectrin knockout mice display impaired endothelium-dependent vasorelaxation that is associated with vascular remodeling, endothelial nitric oxide synthase uncoupling, decreased nitric oxide production, and increased superoxide generation. Treatment with Tempol, a superoxide scavenger, attenuates the augmented sodium sensitivity in collectrin knockout mice. We report for the first time that collectrin is expressed in endothelial cells. Furthermore, collectrin directly regulates l-arginine uptake and plasma membrane levels of CAT1 and y(+)LAT1 amino acid transporters in endothelial cells. Treatment with l-arginine modestly lowers blood pressure of collectrin knockout mice. CONCLUSIONS: Collectrin is a consequential link between the transport of l-arginine and endothelial nitric oxide synthase uncoupling in hypertension.
Assuntos
Hipertensão Renal/metabolismo , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Peptidil Dipeptidase A/genética , Enzima de Conversão de Angiotensina 2 , Animais , Arginina/metabolismo , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Feminino , Hipertensão Renal/genética , Hipertensão Renal/fisiopatologia , Rim/metabolismo , Rim/fisiopatologia , Pulmão/citologia , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Knockout , Natriurese/fisiologia , Óxido Nítrico/metabolismo , Peptidil Dipeptidase A/metabolismo , Cultura Primária de Células , Cloreto de Sódio na Dieta/farmacologia , Superóxidos/metabolismoRESUMO
INTRODUCTION: During female sexual arousal, clitoral blood flow is controlled by endothelial nitric oxide synthase (eNOS) and its product, nitric oxide (NO). The mechanisms regulating eNOS activity and NO bioavailability in the clitoris are largely unknown. AIM: To identify proteins involved in regulation of eNOS activity within the clitoris and to evaluate the effects of S-nitrosoglutathione reductase (GSNO-R) and eNOS nitrosylation/denitrosylation on clitoral blood flow. METHODS: Immunohistochemistry for eNOS, caveolin-1 (Cav1), heat shock protein-90 (Hsp90), phosphodiesterase type 5 (PDE5), GSNO-R, and soluble guanylate cyclase (sGC) was performed on human and murine clitoral tissue. Western blot analysis was performed for eNOS, phosphorylated eNOS (phospho-eNOS, Ser1177), Cav1, Hsp90, sGC, PDE5, phosphoinositide 3-kinase (PI3K), Akt (protein kinase B), and GSNO-R on protein from human clitoral tissue. A biotin switch assay was used to analyze the S-nitrosylation of eNOS, nNOS, and GSNO-R. Clitoral blood flow was measured in wild-type and GSNO-R(-/-) mice at baseline and during cavernous nerve electrical stimulation (CNES). MAIN OUTCOME MEASURES: Localization of eNOS regulatory proteins and clitoral blood flow. RESULTS: eNOS and GSNO-R co-localized to the vascular endothelium and sinusoids of human clitoral tissue. Immunohistochemistry also localized Cav1 and Hsp90 to the endothelium and PDE5 and sGC to the trabecular smooth muscle. Expression of S-nitrosylated (SNO)-eNOS and SNO-GSNO-R was detected by biotin switch assays. Wild-type control mice exhibited increased clitoral blood flow with CNES whereas GSNO-R(-/-) animals failed to show an increase in blood flow. CONCLUSIONS: Several key eNOS regulatory proteins are present in the clitoral tissue in a cellular specific pattern. S-nitrosylation of eNOS may also represent a key regulatory mechanism governing eNOS activation/deactivation since mice deficient in GSNO-R failed to increase clitoral blood flow. Additional studies are necessary to define the role of S-nitrosylation in the genital vascular response and its subsequent impact on female sexual function.
Assuntos
Clitóris/enzimologia , Óxido Nítrico Sintase Tipo III/fisiologia , Óxido Nítrico/fisiologia , Aldeído Oxirredutases/fisiologia , Animais , Caveolina 1/metabolismo , Clitóris/irrigação sanguínea , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5/metabolismo , Endotélio/metabolismo , Endotélio Vascular/metabolismo , Feminino , Guanilato Ciclase/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Camundongos Endogâmicos C57BL , Músculo Liso/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/fisiologia , Receptores Citoplasmáticos e Nucleares/metabolismo , Guanilil Ciclase SolúvelRESUMO
Decreases in arterial blood oxygen stimulate increases in minute ventilation via activation of peripheral and central respiratory structures. This study evaluates the role of endothelial nitric oxide synthase (eNOS) in the expression of the ventilatory responses during and following a hypoxic gas challenge (HXC, 10% O2, 90% N2) in freely moving male and female wild-type (WT) C57BL6 and eNOS knock-out (eNOS-/-) mice. Exposure to HXC caused an array of responses (of similar magnitude and duration) in both male and female WT mice such as, rapid increases in frequency of breathing, tidal volume, minute ventilation and peak inspiratory and expiratory flows, that were subject to pronounced roll-off. The responses to HXC in male eNOS-/- mice were similar to male WT mice. In contrast, several of the ventilatory responses in female eNOS-/- mice (e.g., frequency of breathing, and expiratory drive) were greater compared to female WT mice. Upon return to room-air, male and female WT mice showed similar excitatory ventilatory responses (i.e., short-term potentiation phase). These responses were markedly reduced in male eNOS-/- mice, whereas female eNOS-/- mice displayed robust post-HXC responses that were similar to those in female WT mice. Our data demonstrates that eNOS plays important roles in (1) ventilatory responses to HXC in female compared to male C57BL6 mice; and (2) expression of post-HXC responses in male, but not female C57BL6 mice. These data support existing evidence that sex, and the functional roles of specific proteins (e.g., eNOS) have profound influences on ventilatory processes, including the responses to HXC.
Assuntos
Hipóxia/metabolismo , Óxido Nítrico Sintase Tipo III/genética , Respiração , Animais , Feminino , Hipóxia/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Óxido Nítrico Sintase Tipo III/deficiência , Óxido Nítrico Sintase Tipo III/metabolismo , Ventilação Pulmonar , Fatores Sexuais , Volume de Ventilação PulmonarRESUMO
The roles of endothelial nitric oxide synthase (eNOS) in the ventilatory responses during and after a hypercapnic gas challenge (HCC, 5% CO2, 21% O2, 74% N2) were assessed in freely-moving female and male wild-type (WT) C57BL6 mice and eNOS knock-out (eNOS-/-) mice of C57BL6 background using whole body plethysmography. HCC elicited an array of ventilatory responses that were similar in male and female WT mice, such as increases in breathing frequency (with falls in inspiratory and expiratory times), and increases in tidal volume, minute ventilation, peak inspiratory and expiratory flows, and inspiratory and expiratory drives. eNOS-/- male mice had smaller increases in minute ventilation, peak inspiratory flow and inspiratory drive, and smaller decreases in inspiratory time than WT males. Ventilatory responses in female eNOS-/- mice were similar to those in female WT mice. The ventilatory excitatory phase upon return to room-air was similar in both male and female WT mice. However, the post-HCC increases in frequency of breathing (with decreases in inspiratory times), and increases in tidal volume, minute ventilation, inspiratory drive (i.e., tidal volume/inspiratory time) and expiratory drive (i.e., tidal volume/expiratory time), and peak inspiratory and expiratory flows in male eNOS-/- mice were smaller than in male WT mice. In contrast, the post-HCC responses in female eNOS-/- mice were equal to those of the female WT mice. These findings provide the first evidence that the loss of eNOS affects the ventilatory responses during and after HCC in male C57BL6 mice, whereas female C57BL6 mice can compensate for the loss of eNOS, at least in respect to triggering ventilatory responses to HCC.
Assuntos
Óxido Nítrico Sintase Tipo III/metabolismo , Ventilação Pulmonar/genética , Ventilação Pulmonar/fisiologia , Animais , Feminino , Hipercapnia/fisiopatologia , Hipóxia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Óxido Nítrico Sintase Tipo III/fisiologia , Respiração , Insuficiência Respiratória/fisiopatologia , Volume de Ventilação PulmonarRESUMO
Allogeneic bone marrow transplantation (BMT) is an effective therapy for hematologic malignancies. However graft-versus-host disease (GVHD) is a major limiting factor for a successful patient outcome. GVHD is a result of alloimmune responses of donor T lymphocytes attacking the recipient's cells and tissues. Chemokine receptor CCR5 plays a role in solid organ allograft rejection and mediates murine GVHD pathogenesis. Herein, we report that infiltrating lymphocytes in the skin of human acute GVHD (aGVHD) samples are predominantly CCR5(+) T cells. In addition, we characterized the features of the CCR5 expression on alloreactive T lymphocytes. We found that the CCR5(+) population exhibits the characteristics of the activated effector T cell phenotype. CCR5 expression is upregulated upon allogenic stimulation, and CCR5(+) cells are proliferating with coexpression of T cell activation markers. Furthermore, the activated T cells producing inflammatory cytokine tumor necrosis factor (TNF)alpha, interleukin (IL)-2, or interferon (IFN)-gamma, are positive for CCR5. Thus, CCR5 is a marker for GVHD effector cells and CCR5(+) T cells are active participants in the pathogenesis of human aGVHD.
Assuntos
Doença Enxerto-Hospedeiro/imunologia , Receptores CCR5/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismo , Imunologia de Transplantes/imunologia , Antígenos CD1/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/patologia , Proliferação de Células , Células Dendríticas/imunologia , Doença Enxerto-Hospedeiro/patologia , Humanos , Interferon gama/metabolismo , Interleucina-2/metabolismo , Células de Langerhans/metabolismo , Células de Langerhans/patologia , Leucócitos Mononucleares/imunologia , Lábio/patologia , Ativação Linfocitária/imunologia , Teste de Cultura Mista de Linfócitos , Pele/patologia , Linfócitos T/patologia , Fator de Necrose Tumoral alfa/metabolismoRESUMO
NO transfer reactions between protein and peptide cysteines have been proposed to represent regulated signaling processes. We used the pharmaceutical antioxidant N-acetylcysteine (NAC) as a bait reactant to measure NO transfer reactions in blood and to study the vascular effects of these reactions in vivo. NAC was converted to S-nitroso-N-acetylcysteine (SNOAC), decreasing erythrocytic S-nitrosothiol content, both during whole-blood deoxygenation ex vivo and during a 3-week protocol in which mice received high-dose NAC in vivo. Strikingly, the NAC-treated mice developed pulmonary arterial hypertension (PAH) that mimicked the effects of chronic hypoxia. Moreover, systemic SNOAC administration recapitulated effects of both NAC and hypoxia. eNOS-deficient mice were protected from the effects of NAC but not SNOAC, suggesting that conversion of NAC to SNOAC was necessary for the development of PAH. These data reveal an unanticipated adverse effect of chronic NAC administration and introduce a new animal model of PAH. Moreover, evidence that conversion of NAC to SNOAC during blood deoxygenation is necessary for the development of PAH in this model challenges conventional views of oxygen sensing and of NO signaling.
Assuntos
Hipóxia/metabolismo , Hipóxia/patologia , Artéria Pulmonar/patologia , S-Nitrosotióis/metabolismo , Transdução de Sinais , Acetilcisteína/análogos & derivados , Acetilcisteína/farmacologia , Animais , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Glutationa/análogos & derivados , Glutationa/farmacologia , Hipertensão/fisiopatologia , Hipóxia/induzido quimicamente , Camundongos , Camundongos Knockout , Óxido Nítrico Sintase Tipo III/deficiência , Óxido Nítrico Sintase Tipo III/genética , Óxido Nítrico Sintase Tipo III/metabolismo , Nitrocompostos/farmacologia , Compostos Nitrosos/química , Compostos Nitrosos/farmacologia , Oxigênio/metabolismo , Artéria Pulmonar/fisiopatologiaRESUMO
NADPH diaphorase is used as a histochemical marker of nitric oxide synthase (NOS) in aldehyde-treated tissues. It is thought that the catalytic activity of NOS promotes NADPH-dependent reduction of nitro-blue tetrazolium (NBT) to diformazan. However, it has been argued that a proteinaceous factor other than NOS is responsible for producing diformazan in aldehyde-treated tissues. We propose this is a NO-containing factor such as an S-nitrosothiol and/or a dinitrosyl-iron (II) cysteine complex or nitrosated proteins including NOS. We now report that (1) S-nitrosothiols covalently modify both NBT and TNBT, but only change the reduction potential of NBT after modification, (2) addition of S-nitrosothiols or ß- or α-NADPH to solutions of NBT did not elicit diformazan, (3) addition of S-nitrosothiols to solutions of NBT plus ß- or α-NADPH elicited rapid formation of diformazan in the absence or presence of paraformaldehyde, (4) addition of S-nitrosothiols to solutions of NBT plus ß- or α-NADP did not produce diformazan, (5) S-nitrosothiols did not promote NADPH-dependent reduction of tetra-nitro-blue tetrazolium (TNBT) in which all four phenolic rings are nitrated, (6) cytoplasmic vesicles in vascular endothelial cells known to stain for NADPH diaphorase were rich in S-nitrosothiols, and (7) procedures that accelerate decomposition of S-nitrosothiols, markedly reduced NADPH diaphorase staining in tissue sections subsequently subjected to paraformaldehyde fixation. Our results suggest that NADPH diaphorase in aldehyde-fixed tissues is not enzymatic but is due to the presence of NO-containing factors (free SNOs or nitrosated proteins such as NOS), which promote NADPH-dependent reduction of NBT to diformazan.
Assuntos
NADPH Desidrogenase/metabolismo , Óxido Nítrico Sintase/metabolismo , S-Nitrosotióis/metabolismo , Animais , Compostos Azo/metabolismo , Tronco Encefálico/química , Tronco Encefálico/efeitos dos fármacos , Tronco Encefálico/metabolismo , Cerebelo/química , Cerebelo/efeitos dos fármacos , Cerebelo/metabolismo , Formaldeído/farmacologia , Masculino , Nitroazul de Tetrazólio/metabolismo , Oxirredução , Polímeros/farmacologia , Ratos , Ratos Sprague-Dawley , Coloração e Rotulagem/métodos , Coloração e Rotulagem/normasRESUMO
OBJECTIVE: This study analyzed trends in research activity as represented in the published research in the leading peer-reviewed professional journal for health sciences librarianship. METHODOLOGY: Research articles were identified from the Bulletin of the Medical Library Association and Journal of the Medical Library Association (1991-2007). Using content analysis and bibliometric techniques, data were collected for each article on the (1) subject, (2) research method, (3) analytical technique used, (4) number of authors, (5) number of citations, (6) first author affiliation, and (7) funding source. The results were compared to a previous study, covering the period 1966 to 1990, to identify changes over time. RESULTS: Of the 930 articles examined, 474 (51%) were identified as research articles. Survey (n = 174, 37.1%) was the most common methodology employed, quantitative descriptive statistics (n = 298, 63.5%) the most used analytical technique, and applied topics (n = 332, 70%) the most common type of subject studied. The majority of first authors were associated with an academic health sciences library (n = 264, 55.7%). Only 27.4% (n = 130) of studies identified a funding source. CONCLUSION: This study's findings demonstrate that progress is being made in health sciences librarianship research. There is, however, room for improvement in terms of research methodologies used, proportion of applied versus theoretical research, and elimination of barriers to conducting research for practicing librarians.
Assuntos
Ciência da Informação , Bibliotecas Médicas/tendências , Publicações , Pesquisa/tendências , Sociedades , BibliometriaRESUMO
Neuronal and endothelial nitric oxide synthases (nNOS and eNOS respectively) play major roles in generating the nitric oxide bioactivity necessary for erectile function. S-nitrosylation has been shown to regulate NOS activity. The presence of S-nitrosylated NOS in the penis and the impact of NOS S-nitrosylation/denitrosylation on erectile function were examined. S-nitrosylated forms of NOS were identified by biotin-switch assay followed by western blot analysis. Erectile function in S-nitrosoglutathione reductase deficient (GSNO+/-) and null (GSNO-/-) mice were assessed by continuous cavernous nerve electrical stimulation (CCNES). Glutathione ethyl ester (GSHee) was used to manipulate S-nitrosylated NOS levels. Immunohistological and immunofluorescence analyses were used to identify the location of eNOS and GSNO-R in corporal tissue. eNOS and nNOS were S-nitrosylated in unstimulated penises of the mice. CCNES resulted in a time-dependent increase in eNOS S-nitrosylation with peak eNOS S-nitrosylation observed during detumescence. S-nitrosylated nNOS levels were unchanged. Intracorporal injection of GSHee reduced S-nitrosylated eNOS levels, enhancing time to maximum intracorporal pressure (ICP). eNOS and GSNO-R co-localize to the endothelium of the corpus cavernosum in the mouse and the human. ICP measurements obtained during CCNES demonstrate GSNO-R+/- and GSNO-R-/- animals cannot maintain an elevated ICP. Results suggest eNOS S-nitrosylation/denitrosylation is an important mechanism regulating eNOS activity during erectile function. GSNO-R is a key enzyme involved in the eNOS denitrosylation. The increase in eNOS S-nitrosylation (inactivation) observed with tumescence may begin a cycle leading to detumescence. Clinically this may indicate that alterations in the balance of S-nitrosylation/denitrosylation either directly or indirectly contribute to erectile dysfunction.
Assuntos
Aldeído Oxirredutases/metabolismo , Disfunção Erétil/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Ereção Peniana/fisiologia , Aldeído Oxirredutases/genética , Animais , Endotélio Vascular/metabolismo , Disfunção Erétil/genética , Masculino , Camundongos , Camundongos Knockout , Pênis/metabolismoRESUMO
S-Nitrosylation is a ubiquitous signaling process in biological systems. Research regarding this signaling has been hampered, however, by assays that lack sensitivity and specificity. In particular, iodine-based assays for S-nitrosothiols (1) produce nitrosyliodide, a potent nitrosating agent that can be lost to reactions in the biological sample being studied; (2) require pretreatment of biological samples with several reagents that react with proteins, artifactually forming or breaking S-NO bonds before the assay; and (3) are not sensitive or specific for nitrogen oxides in biological samples, reporting a wide range of different concentrations and falsely reporting NO-modified proteins, to be nitrite. These data, therefore, suggest that iodine-based assays should never be used for biological S-nitrosothiols. There are other assays that provide reasonably sensitive and accurate data regarding biological S-nitrosothiols, including assays based on mass spectrometry, spectrophotometry, chemiluminescence, fluorescence, and immunostaining. Each assay, however, has limitations and should be quantitatively complemented by separate assays. Continued improvement in assays will facilitate improved understanding of S-nitrosylation signaling.
Assuntos
Iodo , S-Nitrosotióis/análise , Animais , Humanos , Sensibilidade e Especificidade , Transdução de SinaisRESUMO
OBJECTIVE: This paper describes the Lamar Soutter Library's process and costs associated with digitizing 300 doctoral dissertations for a newly implemented institutional repository at the University of Massachusetts Medical School. METHODOLOGY: Project tasks included identifying metadata elements, obtaining and tracking permissions, converting the dissertations to an electronic format, and coordinating workflow between library departments. Each dissertation was scanned, reviewed for quality control, enhanced with a table of contents, processed through an optical character recognition function, and added to the institutional repository. RESULTS: Three hundred and twenty dissertations were digitized and added to the repository for a cost of $23,562, or $0.28 per page. Seventy-four percent of the authors who were contacted (n = 282) granted permission to digitize their dissertations. Processing time per title was 170 minutes, for a total processing time of 906 hours. In the first 17 months, full-text dissertations in the collection were downloaded 17,555 times. CONCLUSION: Locally digitizing dissertations or other scholarly works for inclusion in institutional repositories can be cost effective, especially if small, defined projects are chosen. A successful project serves as an excellent recruitment strategy for the institutional repository and helps libraries build new relationships. Challenges include workflow, cost, policy development, and copyright permissions.
Assuntos
Dissertações Acadêmicas como Assunto , Bases de Dados como Assunto , Bibliotecas Digitais/economia , Bibliotecas Médicas , Custos e Análise de Custo , Humanos , Massachusetts , Faculdades de MedicinaRESUMO
Deterioration of neuromuscular junction (NMJ) integrity and function is causal to muscle atrophy and frailty, ultimately hindering quality of life and increasing the risk of death. In particular, NMJ is vulnerable to ischemia reperfusion (IR) injury when blood flow is restricted followed by restoration. However, little is known about the underlying mechanism(s) and hence the lack of effective interventions. New evidence suggests that mitochondrial oxidative stress plays a causal role in IR injury, which can be precluded by enhancing mitochondrial protein S-nitrosation (SNO). To elucidate the role of IR and mitochondrial protein SNO in skeletal muscle, we utilized a clinically relevant model and showed that IR resulted in significant muscle and motor nerve injuries with evidence of elevated muscle creatine kinase in the serum, denervation at NMJ, myofiber degeneration and regeneration, as well as muscle atrophy. Interestingly, we observed that neuromuscular transmission improved prior to muscle recovery, suggesting the importance of the motor nerve in muscle functional recovery. Injection of a mitochondria-targeted S-nitrosation enhancing agent, MitoSNO, into ischemic muscle prior to reperfusion reduced mitochondrial oxidative stress in the motor nerve and NMJ, attenuated denervation at NMJ, and resulted in accelerated functional recovery of the muscle. These findings demonstrate that enhancing mitochondrial protein SNO protects against IR-induced denervation at NMJ in skeletal muscle and accelerates functional regeneration. This could be an efficacious intervention for protecting neuromuscular injury under the condition of IR and other related pathological conditions.
Assuntos
Proteínas Mitocondriais/metabolismo , Músculo Esquelético/patologia , Junção Neuromuscular/patologia , Estresse Oxidativo/fisiologia , Traumatismo por Reperfusão/metabolismo , Animais , Denervação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Músculo Esquelético/metabolismo , Junção Neuromuscular/metabolismo , NitrosaçãoRESUMO
Although Jun upregulation and activation have been established as critical to oncogenesis, the relevant downstream pathways remain incompletely characterized. In this study, we found that c-Jun blocks erythroid differentiation in primary human hematopoietic progenitors and, correspondingly, that Jun factors block transcriptional activation by GATA-1, the central regulator of erythroid differentiation. Mutagenesis of c-Jun suggested that its repression of GATA-1 occurs through a transcriptional mechanism involving activation of downstream genes. We identified the hairy-enhancer-of-split-related factor HERP2 as a novel gene upregulated by c-Jun. HERP2 showed physical interaction with GATA-1 and repressed GATA-1 transcriptional activation. Furthermore, transduction of HERP2 into primary human hematopoietic progenitors inhibited erythroid differentiation. These results thus define a novel regulatory pathway linking the transcription factors c-Jun, HERP2, and GATA-1. Furthermore, these results establish a connection between the Notch signaling pathway, of which the HERP factors are a critical component, and the GATA family, which participates in programming of cellular differentiation.