RESUMO
Natural products perennially serve as prolific sources of drug leads and chemical probes, fueling the development of numerous therapeutics. Despite their scarcity, natural products that modulate protein function through covalent interactions with lysine residues hold immense potential to unlock new therapeutic interventions and advance our understanding of the biological processes governed by these modifications. Phloroglucinol meroterpenoids constitute one of the most expansive classes of natural products, displaying a plethora of biological activities. However, their mechanism of action and cellular targets have, until now, remained elusive. In this study, we detail the concise biomimetic synthesis, computational mechanistic insights, physicochemical attributes, kinetic parameters, molecular mechanism of action, and functional cellular targets of several phloroglucinol meroterpenoids. We harness synthetic clickable analogues of natural products to probe their disparate proteome-wide reactivity and subcellular localization through in-gel fluorescence scanning and cell imaging. By implementing sample multiplexing and a redesigned lysine-targeting probe, we streamline a quantitative activity-based protein profiling, enabling the direct mapping of global reactivity and ligandability of proteinaceous lysines in human cells. Leveraging this framework, we identify numerous lysine-meroterpenoid interactions in breast cancer cells at tractable protein sites across diverse structural and functional classes, including those historically deemed undruggable. We validate that phloroglucinol meroterpenoids perturb biochemical functions through stereoselective and site-specific modification of lysines in proteins vital for breast cancer metabolism, including lipid signaling, mitochondrial respiration, and glycolysis. These findings underscore the broad potential of phloroglucinol meroterpenoids for targeting functional lysines in the human proteome.
Assuntos
Produtos Biológicos , Neoplasias da Mama , Humanos , Feminino , Proteoma/química , Lisina/química , Proteômica/métodos , Floroglucinol/farmacologia , Biomimética , Produtos Biológicos/farmacologiaRESUMO
Blood glucocorticoid levels are regulated by the hypothalamo-pituitary-adrenal/interrenal axis (HPA axis in mammals, HPI axis in amphibians), and negative feedback by glucocorticoid signaling is a key player in that regulation. Glucocorticoid and mineralocorticoid receptors (GR and MR) mediate negative feedback in mammals, but little is known about nuclear receptor-mediated feedback in amphibians. Because amphibians have only one corticosteroidogenic cell type responsible for glucocorticoid and mineralocorticoid production, we hypothesized that GR knockout (GRKO) tadpoles have elevated levels of glucocorticoids and mineralocorticoids as well as axis components regulating their production. We also examined the response to stress and potential for increased aldosterone signaling in GRKO tadpoles. We found that GRKO tadpoles have severe hyperactivity of the HPI axis, namely high mRNA expression levels of pomc, cyp17a1, cyp21a2, cyp11b2, and star, and high tissue content of corticosterone, aldosterone, 17-hydroxyprogesterone, 21-deoxycortisol, and progesterone. Such aberrant HPI activity was accompanied by reduced survival after acute temperature shock and shaking stress. Like mammalian models of HPA hyperactivity, GRKO tadpoles have high MR mRNA expression levels in brain, kidney, heart, and skin and high levels of the inflammatory cytokine tnf-α and the profibrotic factor tgf-ß in kidneys. This study showed GR is critical for negative feedback to the amphibian HPI axis and for survival from acute stressors. This study also showed GRKO tadpoles exhibit altered expression/overproduction of regulators of salt-water homeostasis and associated biomarkers of kidney disease.
Assuntos
Sistema Hipotálamo-Hipofisário , Receptores de Glucocorticoides , Aldosterona/metabolismo , Animais , Corticosterona , Retroalimentação , Glucocorticoides/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Larva/metabolismo , Mamíferos/metabolismo , Sistema Hipófise-Suprarrenal/metabolismo , RNA Mensageiro/genética , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo , Xenopus/metabolismoRESUMO
Metabolic changes that correlate to cognitive changes are well-known in Alzheimer's disease (AD). Metabolism is often linked to functional changes in proteins by post-translational modifications. The importance of the regulation of transcription by acetylation is well documented. Advanced mass spectrometry reveals hundreds of acetylated proteins in multiple tissues, but the acetylome of human brain, its functional significance, and the changes with disease are unknown. Filling this gap is critical for understanding the pathophysiology and development of therapies. To fill this gap, we assessed the human brain acetylome in human brain and its changes with AD. More than 5% of the 4,442 proteins from the human brain global proteome were acetylated. Acetylated proteins were primarily found in the cytosol (148), mitochondria (100), nucleus (91), and plasma membrane (58). The comparison of the brain acetylome in controls to that of patients with AD revealed striking and selective differences in terms of its abundances of acetylated peptides/sites. Acetylation of 18 mitochondrial proteins decreased, while acetylation of two cytosolic proteins, tau and GFAP, increased. Our experiments demonstrate that acetylation at some specific lysine sites alters enzyme function. The results indicate that general activation of de-acetylases (i.e., sirtuins) is not an appropriate therapeutic approach for AD.
Assuntos
Acetilação , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Metaboloma/genética , Proteínas Mitocondriais/metabolismo , Idoso , Idoso de 80 Anos ou mais , Química Encefálica , Biologia Computacional , Feminino , Proteína Glial Fibrilar Ácida/metabolismo , Humanos , Complexo Cetoglutarato Desidrogenase/metabolismo , Lisina/metabolismo , Masculino , Processamento de Proteína Pós-Traducional , Complexo Piruvato Desidrogenase/metabolismo , Frações Subcelulares/metabolismo , Proteínas tau/metabolismoRESUMO
Tandem mass tags (TMTs) have increasingly become an attractive technique for global proteomics. However, its effectiveness for multiplexed quantitation by traditional tandem mass spectrometry (MS2) suffers from ratio distortion. Synchronous precursor selection (SPS) MS3 has been widely accepted for improved quantitation accuracy, but concurrently decreased proteome coverage. Recently, a Real-Time Search algorithm has been integrated with the SPS MS3 pipeline (RTS MS3) to provide accurate quantitation and improved depth of coverage. In this mechanistic study of the impact of exposure to hydrogen sulfide (H2S) on the respiration of swine, we used TMT-based comparative proteomics of lung tissues from control and H2S-treated subjects as a test case to evaluate traditional MS2, SPS MS3, and RTS MS3 acquisition methods on both the Orbitrap Fusion and Orbitrap Eclipse platforms. Comparison of the results obtained by the MS2 with those of SPS MS3 and RTS MS3 methods suggests that the MS3-driven quantitative strategies provided a more accurate global-scale quantitation; however, only RTS MS3 provided proteomic coverage that rivaled that of traditional MS2 analysis. RTS MS3 not only yields more productive MS3 spectra than SPS MS3 but also appears to focus the analysis more effectively on unique peptides. Furthermore, pathway enrichment analyses of the H2S-altered proteins demonstrated that an additional apoptosis pathway was discovered exclusively by RTS MS3. This finding was verified by RT-qPCR, western blotting, and TUNEL staining experiments. We conclude that RTS MS3 workflow enables simultaneous improvement of quantitative accuracy and proteome coverage over alternative approaches (MS2 and SPS MS3). Graphical abstract.
Assuntos
Sulfeto de Hidrogênio/análise , Pulmão/metabolismo , Proteoma , Proteômica/métodos , Espectrometria de Massas em Tandem/métodos , Algoritmos , Animais , Apoptose , Técnicas de Química Analítica , Feminino , Masculino , Peptídeos , Coloração e Rotulagem , SuínosRESUMO
Serum metabolomics and lipidomics are powerful approaches for discovering unique biomarkers in various diseases and associated therapeutics and for revealing metabolic mechanisms of both. Treatment with Benfotiamine (BFT), a thiamine prodrug, for one year produced encouraging results for patients with mild cognitive impairment and mild Alzheimer's disease (AD). In this study, a parallel metabolomics and lipidomics approach was applied for the first exploratory investigation on the serum metabolome and lipidome of patients treated with BFT. A total of 315 unique metabolites and 417 lipids species were confidently identified and relatively quantified. Rigorous statistical analyses revealed significant differences between the placebo and BFT treatment groups in 25 metabolites, including thiamine, tyrosine, tryptophan, lysine, and 22 lipid species, mostly belonging to phosphatidylcholines. Additionally, 10 of 11 metabolites and 14 of 15 lipid species reported in previous literature to follow AD progression changed in the opposite direction to those reported to reflect AD progression. Enrichment and pathway analyses show that significantly altered metabolites by BFT are involved in glucose metabolism and biosynthesis of aromatic amino acids. Our study discovered that multiple novel biomarkers and multiple mechanisms that may underlie the benefit of BFT are potential therapeutic targets in AD and should be validated in studies with larger sample sizes.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Biomarcadores/sangue , Metabolômica/métodos , Tiamina/análogos & derivados , Doença de Alzheimer/sangue , Estudos de Casos e Controles , Cromatografia Líquida , Humanos , Lipídeos/sangue , Espectrometria de Massas , Redes e Vias Metabólicas , Projetos Piloto , Tiamina/administração & dosagem , Tiamina/farmacologiaRESUMO
We describe here the use of label-free wide selected-ion monitoring data-independent acquisition (WiSIM-DIA) to identify proteins that are involved in the formation of tomato (Solanum lycopersicum) fruit cuticles and that are regulated by the transcription factor CUTIN DEFICIENT2 (CD2). A spectral library consisting of 11 753 unique peptides, corresponding to 2338 tomato protein groups, was used and the DIA analysis was performed at the MS1 level utilizing narrow mass windows for extraction with Skyline 2.6 software. We identified a total of 1140 proteins, 67 of which had expression levels that differed significantly between the cd2 tomato mutant and the wild-type cultivar M82. Differentially expressed proteins including a key protein involved in cutin biosynthesis, were selected for validation by target SRM/MRM and by Western blot analysis. In addition to confirming a role for CD2 in regulating cuticle formation, the results also revealed that CD2 influences pathways associated with cell wall biology, anthocyanin biosynthesis, plant development, and responses to stress, which complements findings of earlier RNA-Seq experiments. Our results provide new insights into molecular processes and aspects of fruit biology associated with CD2 function, and demonstrate that the WiSIM-DIA is an effective quantitative approach for global protein identifications.
Assuntos
Frutas/metabolismo , Proteínas de Plantas/metabolismo , Solanum lycopersicum/metabolismo , Fatores de Transcrição/metabolismo , Regulação da Expressão Gênica de Plantas , Proteômica/métodosRESUMO
Sepsis is a diagnostic and therapeutic challenge and is associated with morbidity and a high risk of death. Metabolomic and lipidomic profiling in sepsis can identify alterations in metabolism and might provide useful insights into the dysregulated host response to infection, but investigations in dogs are limited. We aimed to use untargeted metabolomics and lipidomics to characterize metabolic pathways in dogs with sepsis to identify therapeutic targets and potential diagnostic and prognostic biomarkers. In this prospective observational cohort study, we examined the plasma metabolomes and lipidomes of 20 healthy control dogs and compared them with those of 21 client-owned dogs with sepsis. Patient data including signalment, physical exam findings, clinicopathologic data and clinical outcome were recorded. Metabolites were identified using an untargeted mass spectrometry approach and pathway analysis identified multiple enriched metabolic pathways including pyruvaldehyde degradation; ketone body metabolism; the glucose-alanine cycle; vitamin-K metabolism; arginine and betaine metabolism; the biosynthesis of various amino acid classes including the aromatic amino acids; branched chain amino acids; and metabolism of glutamine/glutamate and the glycerophospholipid phosphatidylethanolamine. Metabolites were identified with high discriminant abilities between groups which could serve as potential biomarkers of sepsis including 13,14-Dihydro-15-keto Prostaglandin A2; 12(13)-DiHOME (12,13-dihydroxy-9Z-octadecenoic acid); and 9-HpODE (9-Hydroxyoctadecadienoic acid). Metabolites with higher abundance in samples from nonsurvivors than survivors included 3-(2-hydroxyethyl) indole, indoxyl sulfate and xanthurenic acid. Untargeted lipidomic profiling revealed multiple sphingomyelin species (SM(d34:0)+H; SM(d36:0)+H; SM(d34:0)+HCOO; and SM(d34:1D3)+HCOO); lysophosphatidylcholine molecules (LPC(18:2)+H) and lipophosphoserine molecules (LPS(20:4)+H) that were discriminating for dogs with sepsis. These biomarkers could aid in the diagnosis of dogs with sepsis, provide prognostic information, or act as potential therapeutic targets.
Assuntos
Lipidômica , Sepse , Animais , Biomarcadores , Cães , Humanos , Metabolômica/métodos , Estudos Prospectivos , Sepse/diagnóstico , Sepse/metabolismo , Sepse/veterináriaRESUMO
Recent studies demonstrate that α cells contribute to glucose-stimulated insulin secretion (GSIS). Glucagon-like peptide-1 receptor (GLP-1R) agonists potently potentiate GSIS, making these drugs useful for diabetes treatment. However, the role of α and ß cell paracrine interactions in the effects of GLP-1R agonists is undefined. We previously found that increased ß cell GLP-1R signaling activates α cell GLP-1 expression. Here, we characterized the bidirectional paracrine cross-talk by which α and ß cells communicate to mediate the effects of the GLP-1R agonist, liraglutide. We find that the effect of liraglutide to enhance GSIS is blunted by α cell ablation in male mice. Furthermore, the effect of ß cell GLP-1R signaling to activate α cell GLP-1 is mediated by a secreted protein factor that is regulated by the signaling protein, 14-3-3-zeta, in mouse and human islets. These data refine our understanding of GLP-1 pharmacology and identify 14-3-3-zeta as a potential target to enhance α cell GLP-1 production.
RESUMO
Abnormalities in brain glucose metabolism and accumulation of abnormal protein deposits called plaques and tangles are neuropathological hallmarks of Alzheimer's disease (AD), but their relationship to disease pathogenesis and to each other remains unclear. Here we show that succinylation, a metabolism-associated post-translational protein modification (PTM), provides a potential link between abnormal metabolism and AD pathology. We quantified the lysine succinylomes and proteomes from brains of individuals with AD, and healthy controls. In AD, succinylation of multiple mitochondrial proteins declined, and succinylation of small number of cytosolic proteins increased. The largest increases occurred at critical sites of amyloid precursor protein (APP) and microtubule-associated tau. We show that in vitro, succinylation of APP disrupted its normal proteolytic processing thereby promoting Aß accumulation and plaque formation and that succinylation of tau promoted its aggregation to tangles and impaired microtubule assembly. In transgenic mouse models of AD, elevated succinylation associated with soluble and insoluble APP derivatives and tau. These findings indicate that a metabolism-linked PTM may be associated with AD.
Assuntos
Doença de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Placa Amiloide/metabolismo , Processamento de Proteína Pós-Traducional , Ácido Succínico/metabolismo , Proteínas tau/metabolismo , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Sequência de Aminoácidos , Precursor de Proteína beta-Amiloide/genética , Animais , Autopsia , Encéfalo/metabolismo , Encéfalo/patologia , Estudos de Casos e Controles , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Humanos , Camundongos , Camundongos Transgênicos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Placa Amiloide/genética , Placa Amiloide/patologia , Agregados Proteicos , Proteólise , Proteoma/genética , Proteoma/metabolismo , Proteínas tau/genéticaRESUMO
Hypoxic adaptation mediated by HIF transcription factors requires mitochondria, which have been implicated in regulating HIF1α stability in hypoxia by distinct models that involve consuming oxygen or alternatively converting oxygen into the second messenger peroxide. Here, we use a ratiometric, peroxide reporter, HyPer to evaluate the role of peroxide in regulating HIF1α stability. We show that antioxidant enzymes are neither homeostatically induced nor are peroxide levels increased in hypoxia. Additionally, forced expression of diverse antioxidant enzymes, all of which diminish peroxide, had disparate effects on HIF1α protein stability. Moreover, decrease in lipid peroxides by glutathione peroxidase-4 or superoxide by mitochondrial SOD, failed to influence HIF1α protein stability. These data show that mitochondrial, cytosolic or lipid ROS were not necessary for HIF1α stability, and favor a model where mitochondria contribute to hypoxic adaptation as oxygen consumers.
Assuntos
Hipóxia Celular , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Peróxidos/metabolismo , Animais , Células HeLa , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Masculino , Camundongos , Mitocôndrias/metabolismo , Estabilidade Proteica , Ratos , Ratos Sprague-Dawley , Transdução de SinaisRESUMO
OBJECTIVES: To evaluate the effect of nurse case management on the treatment of older women with breast cancer. DESIGN: Randomized prospective trial. SETTING: Sixty surgeons practicing at 13 community and two public hospitals in southeast Texas. PARTICIPANTS: Three hundred thirty-five women (166 control and 169 intervention) aged 65 and older newly diagnosed with breast cancer. INTERVENTION: Women seeing surgeons randomized to the intervention group received the services of a nurse case manager for 12 months after the diagnosis of breast cancer. MEASUREMENTS: The primary outcome was the type and use of cancer-specific therapies received in the first 6 months after diagnosis. Secondary outcomes were patient satisfaction and arm function on the affected side 2 months after diagnosis. RESULTS: More women in the intervention group received breast-conserving surgery (28.6% vs 18.7%; P=.031) and radiation therapy (36.0% vs 19.0%; P=.003). Of women undergoing breast-conserving surgery, greater percentages in the case management group received adjuvant radiation (78.3% vs 44.8%; P=.001) and axillary dissection (71.4% vs 44.8%; P=.057). Women in the case management group were also more likely to receive more breast reconstruction surgery (9.3% vs 2.6%, P=.054), and women in the case management group with advanced cancer were more likely to receive chemotherapy (72.7% vs 30.0%, P=.057). Two months after surgery, higher percentages of women in the case manager group had normal arm function (93% vs 84%; P=.037) and were more likely to state that they had a real choice in their treatment (82.2% vs 69.9%, P=.020). Women with indicators of poor social support were more likely to benefit from nurse case management. CONCLUSION: Nurse case management results in more appropriate management of older women with breast cancer.
Assuntos
Neoplasias da Mama/terapia , Administração de Caso , Acessibilidade aos Serviços de Saúde , Papel do Profissional de Enfermagem , Apoio Social , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/enfermagem , Neoplasias da Mama/psicologia , Neoplasias da Mama/cirurgia , Interpretação Estatística de Dados , Feminino , Avaliação Geriátrica , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Papel do Médico , Estudos Prospectivos , Escalas de Graduação Psiquiátrica , Fatores Socioeconômicos , Fatores de Tempo , Resultado do TratamentoRESUMO
This descriptive study focuses on evaluating a three-course community health sequence that was converted to a distance learning, web-based format in 1998. The courses are part of the required curriculum for primary care nurse practitioner students and are also taken by most nurse-midwifery students in the master's degree program at the University of Texas Medical Branch School of Nursing at Galveston. All students who completed the courses between 1996 and 2000 were surveyed to determine the extent to which they have applied knowledge and skills gained through these courses in their practices. The investigators also sought to determine whether there were any differences in application to practice between students who took the traditional classroom course, students who took part of the course in the classroom and part online, and students who took the fully web-based course.A further objective was to assess the extent to which Internet resources are being used in their practice. The study results indicated that graduates are incorporating the concepts of the community health courses into their practice; there are no differences in application to practice between the three groups; and Internet resources are being used.
Assuntos
Enfermagem em Saúde Comunitária/educação , Instrução por Computador/normas , Educação a Distância/organização & administração , Educação de Pós-Graduação em Enfermagem/organização & administração , Internet/organização & administração , Profissionais de Enfermagem , Análise de Variância , Atitude do Pessoal de Saúde , Atitude Frente aos Computadores , Competência Clínica/normas , Currículo/normas , Humanos , Aprendizagem , Enfermeiros Obstétricos/educação , Enfermeiros Obstétricos/organização & administração , Enfermeiros Obstétricos/psicologia , Profissionais de Enfermagem/educação , Profissionais de Enfermagem/organização & administração , Profissionais de Enfermagem/psicologia , Papel do Profissional de Enfermagem , Pesquisa em Educação em Enfermagem , Avaliação de Processos e Resultados em Cuidados de Saúde , Avaliação de Programas e Projetos de Saúde , Inquéritos e Questionários , TexasRESUMO
Chieko's story relates in narrative form the childhood and early adult experiences of a Japanese woman who is learning to heal and rebuild her life after growing up in a violent home and ending an abusive marriage. This exemplar illustrates major processes and themes that emerged from a cross-cultural qualitative study of family violence. It also portrays universal aspects of this significant and pervasive health and social issue. This in-depth analysis and commentary on one woman's story that could have occurred almost anywhere uncovers hidden aspects contributing to the recidivism of this phenomenon. This story conveys hope for the many women and children who have no voice and for the clinicians who work with them.
Assuntos
Mulheres Maltratadas/psicologia , Isolamento Social , Maus-Tratos Conjugais/psicologia , Sobreviventes/psicologia , Saúde da Mulher , Adulto , Características Culturais , Feminino , Humanos , Japão , Narração , Direitos da MulherRESUMO
The purpose of this study was to identify and describe the personal experiences of six Japanese female volunteers who formed a support group to provide services for abused women. The interpretation of the women's stories also increased understanding about the process of forming and developing a grassroots organization to take needed action. The interpretive phenomenological approach guided the study. The findings illustrate that a group of community volunteers can identify and effectively address a significant social issue on their own initiative.
Assuntos
Atitude do Pessoal de Saúde , Mulheres Maltratadas , Participação da Comunidade/psicologia , Grupos de Autoajuda/organização & administração , Voluntários/psicologia , Serviços de Saúde da Mulher/organização & administração , Mulheres Maltratadas/educação , Mulheres Maltratadas/psicologia , Escolha da Profissão , Comunicação , Participação da Comunidade/métodos , Comportamento Cooperativo , Feminino , Identidade de Gênero , Promoção da Saúde/organização & administração , Necessidades e Demandas de Serviços de Saúde , Comportamento de Ajuda , Linhas Diretas/organização & administração , Humanos , Japão , Pesquisa Metodológica em Enfermagem , Poder Psicológico , Resolução de Problemas , Desenvolvimento de Programas , Problemas Sociais , Apoio Social , Maus-Tratos Conjugais/prevenção & controle , Maus-Tratos Conjugais/psicologia , Inquéritos e QuestionáriosRESUMO
The cysteine endopeptidase streptopain, an extracellular enzyme from pathogenic Streptococcus pyogenes, is synthesized as a precursor containing an NH2-terminal pro-sequence. The pro-sequence of streptopain was expressed in Escherichia coli and subjected to structural and functional investigation. Heat-induced denaturation of the pro-sequence studied using circular dichroism spectroscopy revealed that it forms a compact structure and represents an independently folded domain. The isolated pro-sequence exhibits high affinity towards mature streptopain and associates with its cognate enzyme by forming an equimolar complex. Refolding of denatured streptopain in the presence of pro-sequence in vitro facilitated recovery of active enzyme. Expression of the mature streptopain in E. coli either alone, or in trans with its pro-sequence as an independent polypeptide, led to the formation of insoluble protein aggregates or functionally active enzyme, respectively. These results demonstrate that the pro-sequence domain acts as an intramolecular chaperone that directs the correct folding of the mature streptopain.
Assuntos
Cisteína Endopeptidases/química , Streptococcus pyogenes/enzimologia , Sítios de Ligação , Western Blotting , Cromatografia , Dicroísmo Circular , Relação Dose-Resposta a Droga , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Escherichia coli/metabolismo , Temperatura Alta , Modelos Moleculares , Conformação Proteica , Desnaturação Proteica , Dobramento de Proteína , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Streptococcus pyogenes/metabolismo , Ressonância de Plasmônio de Superfície , Temperatura , Fatores de TempoRESUMO
PURPOSE/OBJECTIVES: To describe how nurse case managers care for older women with breast cancer. DESIGN: A randomized, prospective trial. SETTING: Thirteen community hospitals and two public hospitals in southeastern Texas. SAMPLE: 335 older women aged 60-89 years newly diagnosed with breast cancer and being cared for by 60 surgeons. Most participants were Caucasian. A total of 166 women were in the control group, and 159 were in the intervention nurse case management group. METHODS: The nurses implemented multiple nursing interventions in each nursing process phase over a period of 12 months. MAIN RESEARCH VARIABLES: Independent variables were participants' demographic characteristics, depressive symptomatology, and cognitive impairment. Nurse case management contact was a dependent variable. FINDINGS: In each nursing phase, a greater number of nurse case management contacts were made in the first quarter. Bivariate analysis illustrated statistical differences among race, income, education, and living alone with respect to the mean amount of nurse case management. Multivariate analysis revealed that age, income, living alone, and stage of cancer predicted more nurse case management contact. CONCLUSIONS: Nurse case managers may play a role in helping older women with breast cancer achieve positive health outcomes. IMPLICATIONS FOR NURSING: Based on the findings of this study, nurses can develop specific nursing interventions to meet the needs of older women with breast cancer. Nurses can use the Model of Nurse Case Management to plan and manage care for older women with breast cancer.
Assuntos
Neoplasias da Mama/enfermagem , Administração de Caso/normas , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Estudos Longitudinais , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
BACKGROUND: There are many challenges that an older woman and her family face when diagnosed with breast cancer. Utilizing community-based nurse case managers may influence the older client and her family to adapt to the many challenges associated with the diagnosis and treatment of breast cancer. PURPOSE: The purpose of this qualitative study is to describe how older breast cancer clients perceive community-based nurse case managers. From findings generated, recommendations were developed to improve the practice of community-based nurse case managers. METHOD: A randomized prospective trial to evaluate the effect of nurse case management on the treatment of 106 older women with breast cancer provided data for this content analysis. Older women (>65 years of age) newly diagnosed with breast cancer cared for by 60 surgeons practicing at 13 community and 2 public hospitals in southeast Texas were invited to participate. DISCUSSION: Community-based nurse case managers made a positive impact on older women with breast cancer by helping in managing coexisting medical conditions, providing support, providing education, giving assistance with activities of daily living (ADLs), and helping to navigate through the health care system. To increase their effectiveness, it was recommended that nurse case managers communicate well, be well educated about breast cancer, have standard gerontology nurse case management training, and integrate multiple support systems when caring for older clients with breast cancer. CONCLUSION: There are unique challenges that an older woman and her family face when diagnosed with breast cancer. Utilizing community-based nurse case managers may influence the client and her family to adapt to the many challenges associated with the diagnosis and treatment of breast cancer. Community-based nurse case managers can make a positive difference on the outcomes of older women with breast cancer.
Assuntos
Idoso/psicologia , Atitude Frente a Saúde , Neoplasias da Mama/psicologia , Administração de Caso/normas , Enfermagem em Saúde Comunitária/normas , Mulheres/psicologia , Atividades Cotidianas , Neoplasias da Mama/enfermagem , Feminino , Comportamento de Ajuda , Humanos , Avaliação das Necessidades , Papel do Profissional de Enfermagem , Pesquisa em Avaliação de Enfermagem , Pesquisa Metodológica em Enfermagem , Defesa do Paciente , Educação de Pacientes como Assunto , Pesquisa Qualitativa , Apoio Social , Inquéritos e Questionários , Texas , Saúde da MulherRESUMO
In this study, we have investigated the interactions of a Staphylococcal recombinant fibronectin-binding protein A (rFnbA) with fibronectin, fibrinogen, and fibrin. Using analytical size-exclusion chromatography, we evaluated the stoichiometry of reversible binding of FnbA to fibronectin and demonstrated that, in solution, it can accommodate at least two molecules of fibronectin. Results of ELISA experiments demonstrated that rFnbA binds with equally high affinity to both immobilized fibrinogen and fibrin. When included into a thrombin-induced fibrin polymerization reaction, rFnbA strongly inhibited fibrin assembly in a dose-dependent manner. In this study, we have shown that rFnbA can act as a substrate for coagulation factor XIIIa. Factor XIIIa catalyzes the incorporation of amine donor (dansylacadaverine) and amine acceptor (peptide patterned on the N-terminal sequence of fibronectin) synthetic probes into rFnbA, suggesting that it serves as a bifunctional substrate containing reactive glutamine and lysine residues. We have demonstrated that the reversible complex formed by rFnbA and fibronectin or rFnbA and fibrin is covalently stabilized by the transglutaminase action of factor XIIIa. Incubation of rFnbA in the presence of either of its ligands and factor XIIIa results in the introduction of intermolecular epsilon-(gamma-glutamyl)lysine isopeptide bond(s) and the formation of high molecular mass heteropolymers. These findings suggest a novel mechanism by which pathogenic Staphylococcus aureus may utilize the transglutaminase activity of factor XIIIa for attachment to soluble proteins, cell surfaces, and matrixes.
Assuntos
Adesinas Bacterianas , Proteínas de Bactérias/metabolismo , Proteínas de Transporte/metabolismo , Reagentes de Ligações Cruzadas/metabolismo , Fator XIIIa/metabolismo , Fibrina/metabolismo , Fibronectinas/metabolismo , Staphylococcus aureus/metabolismo , Aderência Bacteriana , Western Blotting , Catálise , Membrana Celular/enzimologia , Membrana Celular/metabolismo , Membrana Celular/microbiologia , Eletroforese em Gel de Poliacrilamida , Matriz Extracelular/enzimologia , Matriz Extracelular/metabolismo , Matriz Extracelular/microbiologia , Fibronectinas/sangue , Humanos , Polímeros/metabolismo , Ligação Proteica , Proteínas Recombinantes/metabolismo , Dodecilsulfato de Sódio , Staphylococcus aureus/patogenicidade , Especificidade por SubstratoRESUMO
A recombinant streptococcal C5a peptidase was expressed in Escherichia coli and its catalytic properties and thermal stability were subjected to examination. It was shown that the NH2-terminal region of C5a peptidase (Asn32-Asp79/Lys90) forms the pro-sequence segment. Upon maturation the propeptide is hydrolyzed either via an autocatalytic intramolecular cleavage or by exogenous protease streptopain. At pH 7.4 the enzyme exhibited maximum activity in the narrow range of temperatures between 40 and 43 degrees C. The process of heat denaturation of C5a peptidase investigated by fluorescence and circular dichroism spectroscopy revealed that the protein undergoes biphasic unfolding transition with Tm of 50 and 70 degrees C suggesting melting of different parts of the molecule with different stability. Unfolding of the less stable structures was accompanied by the loss of proteolytic activity. Using synthetic peptides corresponding to the COOH-terminus of human complement C5a we demonstrated that in vitro peptidase catalyzes hydrolysis of two His67-Lys68 and Ala58-Ser59 peptide bonds. The high catalytic efficiency obtained for the SQLRANISHKDMQLGR extended peptide compared to the poor hydrolysis of its derivative Ac-SQLRANISH-pNA that lacks residues at P2'-P7' positions, suggest the importance of C5a peptidase interactions with the P' side of the substrate.
Assuntos
Adesinas Bacterianas , Endopeptidases/metabolismo , Streptococcus pyogenes/enzimologia , Sequência de Aminoácidos , Sequência de Bases , Sítios de Ligação , Dicroísmo Circular , DNA Bacteriano/genética , Endopeptidases/química , Endopeptidases/genética , Precursores Enzimáticos/química , Precursores Enzimáticos/genética , Precursores Enzimáticos/metabolismo , Estabilidade Enzimática , Escherichia coli/genética , Temperatura Alta , Humanos , Hidrólise , Técnicas In Vitro , Cinética , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Desnaturação Proteica , Processamento de Proteína Pós-Traducional , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Espectrometria de Fluorescência , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Streptococcus pyogenes/genética , Especificidade por SubstratoRESUMO
Staphylococcal fibronectin-binding protein (FnbA) is a surface-associated receptor responsible for the reversible binding of bacteria to human fibronectin and fibrin(ogen). Recently we have shown that FnbA serves as a substrate for coagulation factor XIIIa and undergoes covalent cross-linking to its ligands, resulting in the formation of heteropolymers (Matsuka, Y. V., Anderson, E. T., Milner-Fish, T., Ooi, P., and Baker, S. (2003) Staphylococcus aureus fibronectin-binding protein serves as a substrate for coagulation factor XIIIa: Evidence for factor XIIIa-catalyzed covalent cross-linking to fibronectin and fibrin, Biochemistry 42, 14643-14652). Factor XIIIa also catalyzes the incorporation in FnbA of fluorescent probes dansylcadaverine and glutamine-containing synthetic peptide patterned on the NH(2)-terminal segment of fibronectin. In this study, the above probes were utilized for site-specific labeling and identification of reactive Gln and Lys residues targeted by factor XIIIa in rFnbA. Probe-decorated rFnbA samples were subjected to trypsin or Glu-C digestion, followed by separation of labeled peptides using reversed phase HPLC. Sequencing and mass spectral analyses of isolated probe-modified peptides have been employed for the identification of factor XIIIa-reactive Gln and Lys residues. Analysis of dansylcadaverine-labeled peptides resulted in the identification of one major, Gln103, and three minor, Gln105, Gln783, and Gln830, amine acceptor sites. The labeling procedure with dansyl-PGGQQIV probe revealed that Lys157, Lys503, Lys620, and Lys762 serve as amine donor sites. The identified reactive glutamine acceptor and lysine donor sites of FnbA may participate in transglutaminase-mediated cross-linking reactions resulting in the covalent attachment of pathogenic Staphylococcus aureus to human host proteins.