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1.
Mol Pharm ; 21(2): 970-981, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38206824

RESUMO

Biodistribution tracks compounds or molecules of interest in vivo to understand a compound's anticipated efficacy and safety. Nanoparticles deliver nucleic acid and drug payloads and enhance tumor permeability due to multiple properties such as high surface area to volume ratio, surface functionalization, and modifications. Studying the in vivo biodistribution of nanoparticles documents the effectiveness and safety of nanoparticles and facilitates a more application-driven approach for nanoparticle development that allows for more successful translation into clinical use. In this study, we present a relatively simple method to determine the biodistribution of magnetic iron nanoparticles in mice. In vitro, cells take up branched amphiphilic peptide-coated magnetic nanobeads (BAPc-MNBs) like their counterparts, i.e., branched amphiphilic peptide capsules (BAPCs) with a hollow water-filled core. Both BAPc-MNBs and BAPCs have widespread applications as a nanodelivery system. We evaluated the BAPc-MNBs tissue distribution in wild-type mice injected intravenously (i.v.), intraperitoneally (i.p.), or orally gavaged to understand the biological interactions and to further the development of branched amphiphilic peptide-based nanoparticles. The magnetic nanoparticles allowed collection of the BAPc-MNBs from multiple organs by magnetic bead sorting, followed by a high-throughput screening for iron content. When injected i.v., nanoparticles were distributed widely to various organs before elimination from the system via the intestines in feces. The spleen accumulated the highest amount of BAPc-MNBs in mice administered NPs via i.v. and i.p. but not via oral gavage. Taken together, these data demonstrate that the magnetic sorting not only allowed quantification of the BAPc-MNBs but also identified the distribution of BAPc-MNBs after distinct administration methods.


Assuntos
Benzenossulfonatos , Nanopartículas de Magnetita , Nanopartículas , Camundongos , Animais , Distribuição Tecidual , Peptídeos/química , Nanopartículas/química , Nanopartículas Magnéticas de Óxido de Ferro , Nanopartículas de Magnetita/química
2.
Support Care Cancer ; 32(7): 468, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38937310

RESUMO

PURPOSE: While numerous studies underscore the benefits of early palliative care (EPC) for patients with solid tumors, its effects on patients with multiple myeloma (MM) are not as widely known. This study aims to determine the effects of EPC integration on patients with newly diagnosed symptomatic MM and the feasibility of this approach. METHODS: This prospective cohort study enrolled patients within eight weeks of diagnosis. Participants met with a palliative care team monthly for 12 months. Functional Assessment of Cancer Therapy-General (FACT-G) plus Multiple Myeloma Subscale (FACT-MM), and Hospital Anxiety and Depression Scale (HADS) were administered upon enrollment and every three months. Proportion of completed visits and assessments determined the feasibility of EPC. RESULTS: Of the twenty participants enrolled from January 2020 to November 2022, median age was 65 (range 40, 77), 15 (75%) were female, 15 (75%) were white, 65% completed assessments at six months, and 60% at 12 months. The following measures significantly improved at 12 months versus baseline: FACT-G scores increased by 15.1 points (adjusted 95% CI: 2.2-28.1, adjusted p = 0.02); Functional Well-Being scores increased by 6.0 points (adjusted 95% CI: 1.1-10.9, adjusted p = 0.01); and Pain Subscale scores increased by 3.4 points (adjusted 95% CI: 0.5-6.4, adjusted p = 0.02). Depression and anxiety scores did not significantly change over time. CONCLUSION: Functional well-being, pain experience and overall QOL improved in a cohort of patients with newly diagnosed MM after 12 months of EPC involvement. Although monthly visits seemed feasible, the findings suggest that further research is needed to explore the optimal timing of palliative care interventions in the MM trajectory. TRIAL REGISTRATION: ClinicalTrials.gov ID NCT04248244 (Registration Date: January 30, 2020).


Assuntos
Mieloma Múltiplo , Cuidados Paliativos , Humanos , Mieloma Múltiplo/terapia , Mieloma Múltiplo/psicologia , Feminino , Masculino , Cuidados Paliativos/métodos , Pessoa de Meia-Idade , Idoso , Estudos Prospectivos , Adulto , Qualidade de Vida , Estudos de Coortes , Depressão/etiologia , Ansiedade/etiologia
3.
AIDS Care ; 34(7): 839-846, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34496705

RESUMO

Young Black sexual minority men (YBSMM) represent a high-priority population for HIV prevention research. HIV testing is a critical public health tool to prevent HIV transmission and is an integral component of health care for high-priority populations. The present study uses Andersen's model of health care utilization as a framework to explore the HIV testing preferences of YBSMM and the barriers and facilitators to receiving HIV services as a means to increase regular HIV testing. A sample of 57 YBSMM (M =19 years) in Washington, DC responded to closed and open-ended questions regarding preferences for HIV testing across various venues. Approximately 61% of the sample reported a previous HIV test and 12% reported a positive result. Participants were most willing to receive free HIV testing at medical establishments and schools. Concerns for privacy were most notable for testing at churches, malls, and schools. Identified barriers to receiving HIV services included cost, stigma, privacy, and access whereas identified facilitators included low cost and support. The findings encourage integrating regular HIV testing into the health care regiment of YBSMM and increasing youth's autonomy over their sexual health.


Assuntos
Infecções por HIV , Minorias Sexuais e de Gênero , Adolescente , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Teste de HIV , Homossexualidade Masculina , Humanos , Masculino , Estigma Social
4.
Psychopathology ; 54(6): 325-334, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34407538

RESUMO

INTRODUCTION: Cognitive failures are commonplace within the general population but may be particularly heightened in those with higher levels of schizotypy. This is especially salient in the context of enduring trait and momentary state negative emotion which often contributes to increases in daily impairments, leading to a more debilitating and distracted life. Particularly, individuals with elevated levels of schizotypy may be more likely to experience cognitive failures, especially in the presence of negative trait emotion such as depression, anxiety, and stress. However, little is known about the influence of state emotion and the distinct roles that state and trait emotion may have with cognitive failures and schizotypy. METHODS: To replicate and extend previous findings, 306 (58% males) undergraduate students aged 18-50 years (M = 19.343; SD = 2.493) completed self-report measures of cognitive failures, trait and state emotion, and schizotypy. Mediation and moderation analyses were performed in SPSS to examine the potential effects of trait and state emotion on the relationship between schizotypy and cognitive failures. RESULTS: Consistent with previous findings, mood symptomology, in addition to negative affect, mediated cognitive failures in those with higher levels of schizotypy. However, in our sample, positive affect did not appear to buffer against cognitive failures. CONCLUSION: The findings of the present study suggest there may be a nuanced relationship between both negative trait and state emotions on the relationships between cognitive failures and schizotypy. Understanding the interaction of enduring versus momentary emotion on cognition as they relate to an elevated risk for developing schizophrenia-spectrum phenomena may be a point for earlier and more targeted interventions.


Assuntos
Transtornos Cognitivos , Esquizofrenia , Transtorno da Personalidade Esquizotípica , Cognição , Emoções , Feminino , Humanos , Masculino , Transtorno da Personalidade Esquizotípica/diagnóstico
5.
Clin Immunol ; 220: 108596, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32961332

RESUMO

Intestinal ischemia/reperfusion (I/R)-induced injury is an inflammatory response with significant morbidity and mortality. The early inflammatory response includes neutrophil infiltration. However, the majority of rodent studies utilize male mice despite a sexual dimorphism in intestinal I/R-related diseases. We hypothesized that sex may alter inflammation by changing neutrophil infiltration and eicosanoid production. To test this hypothesis, male and female C57Bl/6 mice were subjected to sham treatment or 30 min intestinal ischemia followed by a time course of reperfusion. We demonstrate that compared to male mice, females sustain significantly less intestinal I/R-induced tissue damage and produced significant LTB4 concentrations. Male mice release PGE2. Finally, treatment with a COX-2 specific inhibitor, NS-398, attenuated I/R-induced injury, total peroxidase level, and PGE2 production in males, but not in similarly treated female mice. Thus, I/R-induced eicosanoid production and neutrophil infiltration varies between sexes suggesting that distinct therapeutic intervention may be needed in clinical ischemic diseases.


Assuntos
Dinoprostona/imunologia , Leucotrieno B4/imunologia , Mesentério/irrigação sanguínea , Traumatismo por Reperfusão/imunologia , Caracteres Sexuais , Animais , Complemento C5a/imunologia , Citocinas/imunologia , Eicosanoides/imunologia , Feminino , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Intestino Delgado/imunologia , Intestino Delgado/patologia , Macrófagos/imunologia , Masculino , Camundongos Endogâmicos C57BL , Infiltração de Neutrófilos , Peroxidase/imunologia , Traumatismo por Reperfusão/patologia
6.
Clin Immunol ; 212: 108351, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32028020

RESUMO

The innate immune response is crucial for defense against virus infections where the complement system, coagulation cascade and natural antibodies play key roles. These immune components are interconnected in an intricate network and are tightly regulated to maintain homeostasis and avoid uncontrolled immune responses. Many viruses in turn have evolved to modulate these interactions through various strategies to evade innate immune activation. This review summarizes the current understanding on viral strategies to inhibit the activation of complement and coagulation cascades, evade natural antibody-mediated clearance and utilize complement regulatory mechanisms to their advantage.


Assuntos
Anticorpos/imunologia , Coagulação Sanguínea/imunologia , Ativação do Complemento/imunologia , Imunidade Humoral/imunologia , Imunidade Inata/imunologia , Viroses/imunologia , Vírus/patogenicidade , Animais , Humanos , Evasão da Resposta Imune/imunologia
7.
Mol Pharm ; 17(6): 2208-2220, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32324415

RESUMO

Understanding cellular uptake mechanisms of nanoparticles with therapeutic potential has become critical in the field of drug delivery. Elucidation of cellular entry routes can aid in the dissection of the complex intracellular trafficking and potentially allow for the manipulation of nanoparticle fate after cellular delivery (i.e., avoid lysosomal degradation). Branched amphiphilic peptide capsules (BAPCs) are peptide nanoparticles that have been and are being explored as delivery systems for nucleic acids and other therapeutic molecules in vitro and in vivo. In the present study, we determined the cellular uptake routes of BAPCs with and without a magnetic nanobead core (BAPc-MNBs) in two cell lines: macrophages and intestinal epithelial cells. We also studied the influence of size and growth media composition in this cellular process. Substituting the water-filled core with magnetic nanobeads might provide the peptide bilayer nanocapsules with added functionalities, facilitating their use in bio/immunoassays, magnetic field guided drug delivery, and magnetofection among others. Results suggest that BAPc-MNBs are internalized into the cytosol using more than one endocytic pathway. Flow cytometry and analysis of reactive oxygen and nitrogen species (ROS/RNS) demonstrated that cell viability was minimally impacted by BAPc-MNBs. Cellular uptake pathways of peptide vesicles remain poorly understood, particularly with respect to endocytosis and intracellular trafficking. Outcomes from these studies provide a fundamental understanding of the cellular uptake of this peptide-based delivery system which will allow for strengthening of their delivery capabilities and expanding their applications both in vitro and in vivo.


Assuntos
Peptídeos/química , Endocitose/fisiologia , Citometria de Fluxo , Microscopia Confocal , Nanopartículas/química , Espécies Reativas de Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo
8.
Am J Physiol Heart Circ Physiol ; 317(4): H732-H742, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31397167

RESUMO

Preeclampsia is a prevalent pregnancy complication characterized by new-onset maternal hypertension and inflammation, with placental ischemia as the initiating event. Studies of others have provided evidence for the importance of lymphocytes in placental ischemia-induced hypertension; however, the contributions of B1 versus B2 lymphocytes are unknown. We hypothesized that peritoneal B1 lymphocytes are important for placental ischemia-induced hypertension. As an initial test of this hypothesis, the effect of anti-CD20 depletion on both B-cell populations was determined in a reduced utero-placental perfusion pressure (RUPP) model of preeclampsia. Anti-murine CD20 monoclonal antibody (5 mg/kg, Clone 5D2) or corresponding mu IgG2a isotype control was administered intraperitoneally to timed pregnant Sprague-Dawley rats on gestation day (GD)10 and 13. RUPP or sham control surgeries were performed on GD14, and mean arterial pressure (MAP) was measured on GD19 from a carotid catheter. As anticipated, RUPP surgery increased MAP and heart rate and decreased mean fetal and placental weight. However, anti-CD20 treatment did not affect these responses. On GD19, B-cell populations were enumerated in the blood, peritoneal cavity, spleen, and placenta with flow cytometry. B1 and B2 cells were not significantly increased following RUPP. Anti-CD20 depleted B1 and B2 cells in peritoneum and circulation but depleted only B2 lymphocytes in spleen and placenta, with no effect on circulating or peritoneal IgM. Overall, these data do not exclude a role for antibodies produced by B cells before depletion but indicate the presence of B lymphocytes in the last trimester of pregnancy is not critical for placental ischemia-induced hypertension.NEW & NOTEWORTHY The adaptive and innate immune systems are implicated in hypertension, including the pregnancy-specific hypertensive condition preeclampsia. However, the mechanism of immune system dysfunction leading to pregnancy-induced hypertension is unresolved. In contrast to previous reports, this study reveals that the presence of classic B2 lymphocytes and peritoneal and circulating B1 lymphocytes is not required for development of hypertension following third trimester placental ischemia in a rat model of pregnancy-induced hypertension.


Assuntos
Pressão Arterial , Subpopulações de Linfócitos B/imunologia , Circulação Placentária , Pré-Eclâmpsia/imunologia , Animais , Anticorpos Monoclonais/farmacologia , Antígenos CD20/imunologia , Subpopulações de Linfócitos B/efeitos dos fármacos , Subpopulações de Linfócitos B/metabolismo , Modelos Animais de Doenças , Endotelina-1/metabolismo , Feminino , Retardo do Crescimento Fetal/imunologia , Retardo do Crescimento Fetal/fisiopatologia , Idade Gestacional , Imunoglobulina M/sangue , Depleção Linfocítica , Pré-Eclâmpsia/sangue , Pré-Eclâmpsia/fisiopatologia , Gravidez , Ratos Sprague-Dawley
9.
Nucleic Acids Res ; 44(18): 8704-8713, 2016 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-27325740

RESUMO

ATF4 is a pro-oncogenic transcription factor whose translation is activated by eIF2 phosphorylation through delayed re-initiation involving two uORFs in the mRNA leader. However, in yeast, the effect of eIF2 phosphorylation can be mimicked by eIF5 overexpression, which turns eIF5 into translational inhibitor, thereby promoting translation of GCN4, the yeast ATF4 equivalent. Furthermore, regulatory protein termed eIF5-mimic protein (5MP) can bind eIF2 and inhibit general translation. Here, we show that 5MP1 overexpression in human cells leads to strong formation of 5MP1:eIF2 complex, nearly comparable to that of eIF5:eIF2 complex produced by eIF5 overexpression. Overexpression of eIF5, 5MP1 and 5MP2, the second human paralog, promotes ATF4 expression in certain types of human cells including fibrosarcoma. 5MP overexpression also induces ATF4 expression in Drosophila The knockdown of 5MP1 in fibrosarcoma attenuates ATF4 expression and its tumor formation on nude mice. Since 5MP2 is overproduced in salivary mucoepidermoid carcinoma, we propose that overexpression of eIF5 and 5MP induces translation of ATF4 and potentially other genes with uORFs in their mRNA leaders through delayed re-initiation, thereby enhancing the survival of normal and cancer cells under stress conditions.


Assuntos
Fator 4 Ativador da Transcrição/metabolismo , Proteínas de Ligação a DNA/metabolismo , Fator de Iniciação 2 em Eucariotos/metabolismo , Fator de Iniciação 5 em Eucariotos/metabolismo , Iniciação Traducional da Cadeia Peptídica , Animais , Carcinogênese/patologia , Linhagem Celular Tumoral , Drosophila melanogaster/metabolismo , Fator de Iniciação 3 em Eucariotos , Fibrossarcoma/patologia , Técnicas de Silenciamento de Genes , Células HEK293 , Células HeLa , Humanos , Masculino , Espectrometria de Massas , Camundongos Nus
10.
Cogn Neuropsychiatry ; 23(1): 43-57, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29258396

RESUMO

INTRODUCTION: Research suggests that levels of schizotypy are related to cognitive and social functioning, with negative schizotypy being particularly related to deficits in verbal fluency (VF) and distinct social skills. Considering the possibility that different VF tasks may involve both shared and unique underlying processes, this study sought to examine the separate contributions of categorical and phonological forms of VF to social functioning in those with varying levels of negative schizotypy. METHODS: Face-to-face interviews were conducted in which 228 college students completed VF tasks, the SPQ-BR, and a social functioning questionnaire. RESULTS: Both phonological and categorical VF were inversely related to levels of negative schizotypy and inversely related to several social functioning domains. High and low levels of negative schizotypy groups were significantly different on elements of social engagement and interpersonal behaviour. In two instances, phonological VF appeared to moderate the relationships between negative schizotypy and specific elements of social functioning. CONCLUSIONS: These findings support a general link between verbal processing and social functioning among those with greater negative schizotypy. Possible avenues of future research are discussed.


Assuntos
Transtorno da Personalidade Esquizotípica/diagnóstico , Transtorno da Personalidade Esquizotípica/psicologia , Ajustamento Social , Estudantes/psicologia , Comportamento Verbal/fisiologia , Adolescente , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Inquéritos e Questionários , Adulto Jovem
11.
Curr Hypertens Rep ; 19(11): 87, 2017 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-29046976

RESUMO

PURPOSE OF REVIEW: Preeclampsia affects 3-4% of pregnancies with few treatment options to reduce maternal and fetal harm. Recent evidence that targeting the complement system may be an effective therapeutic strategy in prevention or treatment of preeclampsia will be reviewed. RECENT FINDINGS: Studies in humans confirm the safety and efficacy of C5 blockade in complement-mediated disorders of pregnancy, including preeclampsia. Animal models mimic the placental abnormalities and/or the maternal symptoms which characterize preeclampsia. These models in mouse and rat have defined a role for complement and its regulators in placental dysfunction, hypertension, proteinuria, endothelial dysfunction, fetal growth restriction, and angiogenic imbalance, thus informing future human studies. Targeting excessive complement activation, particularly the terminal complement complex (C5b-9) and C5a may be an effective strategy to prolong pregnancy in women with preeclampsia. Continued research is needed to identify the initiator(s) of activation, the pathways involved, and the key component(s) in the pathophysiology to allow development of safe and effective therapeutics to target complement without compromising its role in homeostasis and host defense.


Assuntos
Ativação do Complemento/fisiologia , Placenta/fisiopatologia , Pré-Eclâmpsia/fisiopatologia , Animais , Complemento C5a/fisiologia , Complexo de Ataque à Membrana do Sistema Complemento/fisiologia , Modelos Animais de Doenças , Endotélio Vascular/fisiopatologia , Feminino , Retardo do Crescimento Fetal/fisiopatologia , Homeostase , Humanos , Hipertensão/fisiopatologia , Camundongos , Neovascularização Patológica/fisiopatologia , Gravidez , Proteinúria/fisiopatologia , Ratos
12.
J Immunol ; 194(3): 1190-8, 2015 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-25539820

RESUMO

In multiple clinical conditions, including trauma and hemorrhage, reperfusion magnifies ischemic tissue damage. Ischemia induces expression of multiple neoantigens, including lipid alterations that are recognized by the serum protein, ß2-glycoprotein I (ß2-GPI). During reperfusion, binding of ß2-GPI by naturally occurring Abs results in an excessive inflammatory response that may lead to death. As ß2-GPI is critical for intestinal ischemia/reperfusion (IR)-induced tissue damage and TLR2 is one of the proposed receptors for ß2-GPI, we hypothesized that IR-induced intestinal damage and inflammation require TLR2. Using TLR2(-/-) mice, we demonstrate that TLR2 is required for IR-induced mucosal damage, as well as complement activation and proinflammatory cytokine production. In response to IR, TLR2(-/-) mice have increased serum ß2-GPI compared with wild-type mice, but ß2-GPI is not deposited on ischemic intestinal tissue. In addition, TLR2(-/-) mice also did not express other novel Ags, suggesting a sequential response. Unlike other TLRs, TLR2(-/-) mice lacked the appropriate Ab repertoire to induce intestinal IR tissue damage or inflammation. Together, these data suggest that, in addition to the inflammatory response, IR-induced injury requires TLR2 for naturally occurring Ab production.


Assuntos
Anticorpos/imunologia , Inflamação/imunologia , Inflamação/metabolismo , Mucosa Intestinal/metabolismo , Intestinos/imunologia , Traumatismo por Reperfusão/imunologia , Traumatismo por Reperfusão/metabolismo , Receptor 2 Toll-Like/metabolismo , Animais , Anticorpos/sangue , Proteínas do Sistema Complemento/imunologia , Citocinas/biossíntese , Modelos Animais de Doenças , Eicosanoides/biossíntese , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Inflamação/genética , Inflamação/patologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Intestinos/patologia , Camundongos , Camundongos Knockout , Traumatismo por Reperfusão/genética , Receptor 2 Toll-Like/genética , beta 2-Glicoproteína I/imunologia , beta 2-Glicoproteína I/metabolismo
13.
J Emerg Med ; 53(4): 458-466, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29079066

RESUMO

BACKGROUND: Injured older adults often receive delayed care in the emergency department (ED) because they do not meet criteria for trauma team activation (TTA). This is particularly dangerous for the increasing number of patients taking anticoagulant or antiplatelet (AC/AP) medication at the time of injury. OBJECTIVES: The present study examined improvements in processes of care and triage accuracy when TTA criteria include an escalated response for older anticoagulated patients. METHODS: A retrospective study was performed at a Level I trauma center. The study population (referred to as A55) included patients aged 55 years or older who were taking an AC/AP medication at the time of injury. Study periods included 11 months prior to the criteria change (Phase 1: July 2013-May 2014; n = 107) and 11 months after the change (Phase 2: July 2014-May 2015; n = 211). Differences were assessed with Kruskal-Wallis and chi-squared tests. RESULTS: More A55 patients received a full or limited TTA after criteria were revised (70% vs. 26%, p < 0.001). Undertriage was reduced from 13% to 2% (p < 0.001). The trauma center significantly decreased time to first laboratory result, time to first computed tomography scan, and total time in ED prior to admission for A55 patients arriving from the scene of injury or by private vehicle. CONCLUSION: Criteria that escalated the trauma response for A55 patients led to reductions in undertriage for anticoagulated older adults, as well as more timely mobilization of important clinical resources.


Assuntos
Anticoagulantes/efeitos adversos , Defesa Civil/métodos , Geriatria/métodos , Centros de Traumatologia/tendências , Acidentes por Quedas/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/uso terapêutico , Distribuição de Qui-Quadrado , Defesa Civil/tendências , Serviço Hospitalar de Emergência/organização & administração , Feminino , Geriatria/tendências , Humanos , Masculino , Pessoa de Meia-Idade , Meio-Oeste dos Estados Unidos , Inibidores da Agregação Plaquetária/efeitos adversos , Inibidores da Agregação Plaquetária/uso terapêutico , Sistema de Registros/estatística & dados numéricos , Centros de Traumatologia/organização & administração , Triagem/métodos , Triagem/normas
14.
Biophys J ; 111(1): 178-84, 2016 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-27410745

RESUMO

Actomyosin kinetics is usually studied in dilute solutions, which do not reflect conditions in the cytoplasm. In cells, myosin and actin work in a dense macromolecular environment. High concentrations of macromolecules dramatically reduce the amount of free space available for all solutes, which results in an effective increase of the solutes' chemical potential and protein stabilization. Moreover, in a crowded solution, the chemical potential depends on the size of the solute, with larger molecules experiencing a larger excluded volume than smaller ones. Therefore, since myosin interacts with two ligands of different sizes (actin and ATP), macromolecular crowding can modulate the kinetics of individual steps of the actomyosin ATPase cycle. To emulate the effect of crowding in cells, we studied actomyosin cycle reactions in the presence of a high-molecular-weight polymer, Ficoll70. We observed an increase in the maximum velocity of the actomyosin ATPase cycle, and our transient-kinetics experiments showed that virtually all individual steps of the actomyosin cycle were affected by the addition of Ficoll70. The observed effects of macromolecular crowding on the myosin-ligand interaction cannot be explained by the increase of a solute's chemical potential. A time-resolved Förster resonance energy transfer experiment confirmed that the myosin head assumes a more compact conformation in the presence of Ficoll70 than in a dilute solution. We conclude that the crowding-induced myosin conformational change plays a major role in the changed kinetics of actomyosin ATPase.


Assuntos
Actomiosina/metabolismo , Ficoll/farmacologia , Difosfato de Adenosina/metabolismo , Adenosina Trifosfatases/metabolismo , Trifosfato de Adenosina/metabolismo , Hidrólise/efeitos dos fármacos , Cinética
15.
Semin Diagn Pathol ; 33(1): 31-42, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26602569

RESUMO

The widespread use of abdominal ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) has resulted in an increased identification of asymptomatic pancreatic lesions. Preoperative diagnoses of pancreatic lesions can be difficult. Solid and cystic lesions and anatomic variants of normal can all mimic tumor clinically and radiologically. Newer imaging modalities have increased the likelihood of the accurate diagnosis of non-neoplastic pancreatic disease, however, despite the many advances; it still remains a challenge to differentiate rarer non-neoplastic entities and inflammatory masses from adenocarcinoma, preoperatively. Adding to the challenge is the fact that a variety of inflammatory, solid and cystic non-neoplastic lesions have significant clinical and radiological overlap with malignancies. About 5-10% of pancreatectomies performed with the primary clinical diagnosis of pancreatic carcinoma are later proved to be essentially non-neoplastic lesions. It is vital to include these non-neoplastic entities in the differential diagnosis while working up abnormal clinical and radiological pancreatic findings because it may drastically alter therapeutic options for the patients. The significance of recognizing these lesions preoperatively is to help to guide the clinical decision-making process and the avoidance of an unnecessary pancreatectomy. Examples of such entities include chronic pancreatitis, sarcoidosis, intrapancreatic accessory spleen (IPAS), lymphoid hyperplasia, lipomatous pseudohypertrophy (LPH), lymphangioma, lymphoepithelial cyst (LEC) and endometriosis.


Assuntos
Pancreatopatias/diagnóstico , Neoplasias Pancreáticas/diagnóstico , Diagnóstico Diferencial , Humanos
16.
Clin Immunol ; 160(2): 244-54, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26145788

RESUMO

The humoral innate immune system is composed of three major branches, complement, coagulation, and natural antibodies. To persist in the host, pathogens, such as bacteria, viruses, and cancers must evade parts of the innate humoral immune system. Disruptions in the humoral innate immune system also play a role in the development of autoimmune diseases. This review will examine how Gram positive bacteria, viruses, cancer, and the autoimmune conditions systemic lupus erythematosus and anti-phospholipid syndrome, interact with these immune system components. Through examining evasion techniques it becomes clear that an interplay between these three systems exists. By exploring the interplay and the evasion/disruption of the humoral innate immune system, we can develop a better understanding of pathogenic infections, cancer, and autoimmune disease development.


Assuntos
Doenças Autoimunes/imunologia , Infecções por Bactérias Gram-Positivas/imunologia , Evasão da Resposta Imune/imunologia , Imunidade Humoral/imunologia , Imunidade Inata/imunologia , Neoplasias/imunologia , Evasão Tumoral/imunologia , Viroses/imunologia , Anticorpos/imunologia , Estudos de Coortes , Proteínas do Sistema Complemento/imunologia , Humanos
18.
Lupus ; 24(12): 1335-7, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25972365

RESUMO

Toe walking is a previously unreported presentation of systemic lupus erythematosus (SLE). We describe a patient who presented with profound multisystem involvement that was preceded by one month of toe walking and multiple flexion contractures without arthritis. Her lupus is now under control after aggressive therapy, yet she continues to struggle with tendinopathy despite continued physical and occupational therapy. Lupus should be considered in the appropriate clinical context in children who have new-onset contractures due to tight tendons.


Assuntos
Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/terapia , Tendinopatia/etiologia , Caminhada , Adolescente , Feminino , Humanos , Metilprednisolona/administração & dosagem , Terapia Ocupacional/métodos , Modalidades de Fisioterapia , Tendinopatia/reabilitação , Dedos do Pé
19.
Clin Immunol ; 153(1): 228-40, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24814240

RESUMO

Ischemia, lack of blood flow, and reperfusion, return of blood flow, are a common phenomenon affecting millions of Americans each year. Roughly 30,000 Americans per year experience intestinal ischemia-reperfusion (IR), which is associated with a high mortality rate. Previous studies of the intestine established a role for neutrophils, eicosanoids, the complement system and naturally occurring antibodies in IR-induced pathology. Furthermore, data indicate involvement of a lipid or lipid-like moiety in mediating IR-induced damage. It has been proposed that antibodies recognize exposure of neo-antigens, triggering action of the complement cascade. While it is evident that the pathophysiology of IR-induced injury is complex and multi-factorial, we focus this review on the involvement of eicosanoids, phospholipids and neo-antigens in the early pathogenesis. Lipid changes occurring in response to IR, neo-antigens exposed and the role of a phospholipid transporter, phospholipid scramblase 1 will be discussed.


Assuntos
Mucosa Intestinal/metabolismo , Intestinos/patologia , Lipídeos de Membrana/metabolismo , Traumatismo por Reperfusão/metabolismo , Animais , Anticorpos/imunologia , Antígenos/imunologia , Humanos , Hipóxia/metabolismo , Intestinos/irrigação sanguínea , Intestinos/imunologia , Proteínas de Transferência de Fosfolipídeos/metabolismo , Traumatismo por Reperfusão/imunologia , Transdução de Sinais
20.
J Immunol ; 189(10): 5047-56, 2012 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-23034168

RESUMO

Intestinal ischemic events, which are followed by reperfusion, induce significant tissue damage and frequently result in multiple organ failure, with >70% mortality. Upon reperfusion, excessive inflammation leads to exacerbated tissue damage. Previous studies indicated that binding of the serum protein, ß2-glycoprotein I, to the endothelium initiates a cascade of inflammatory molecules that is required for damage. We hypothesized that peptides derived from the binding domain (domain V) of ß2-glycoprotein I would attenuate ischemia/reperfusion-induced damage and inflammation in a therapeutic manner. Using a mouse model of intestinal ischemia/reperfusion, we administered peptides either prior to ischemia or at clinically relevant time points during reperfusion and evaluated intestinal tissue damage and inflammation after 2 h of reperfusion. We demonstrate that multiple peptides attenuate injury and inflammation in a dose-dependent manner and, perhaps more significantly, are efficacious when administered up to 30 min after the onset of reperfusion. In addition, an all D-amino acid retro-inverso peptide was biologically active. Thus, the ß2-glycoprotein I-derived peptides attenuate injury and inflammation when administered in a therapeutic manner in intestinal ischemia/reperfusion injury.


Assuntos
Intestinos/imunologia , Peptídeos/farmacologia , Traumatismo por Reperfusão/imunologia , Traumatismo por Reperfusão/prevenção & controle , beta 2-Glicoproteína I/farmacologia , Animais , Modelos Animais de Doenças , Endotélio Vascular/imunologia , Endotélio Vascular/patologia , Inflamação/imunologia , Inflamação/patologia , Inflamação/prevenção & controle , Intestinos/patologia , Camundongos , Peptídeos/imunologia , Estrutura Terciária de Proteína , Traumatismo por Reperfusão/patologia , Fatores de Tempo , beta 2-Glicoproteína I/imunologia
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