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1.
RNA ; 27(6): 676-682, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33762403

RESUMEN

Circular (circ) RNA expression vectors are used as a method of identifying and characterizing RNA sequences that harbor internal ribosome entry site (IRES) activity. During the course of developing a vector series tailored for IRES discovery, we found evidence for the occurrence of trans-spliced mRNAs arising when sequences with promoter activity were embedded between the upstream CTD and downstream NTD exons of the pre-mRNA. These trans-spliced products regenerate the same open reading frame expected from a circRNA and can lead to false-positive signals in screens relying on circRNA expression vectors for IRES discovery. Our results caution against interpretations of IRES activity solely based on results obtained from circRNA expression vectors.


Asunto(s)
Sitios Internos de Entrada al Ribosoma , ARN Circular/metabolismo , Trans-Empalme , Animales , Expresión Génica , Vectores Genéticos/genética , Humanos , Regiones Promotoras Genéticas , Precursores del ARN/genética
2.
Cell Mol Life Sci ; 78(19-20): 6709-6719, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34559254

RESUMEN

Eukaryotic initiation factor (eIF) 4F plays a central role in the ribosome recruitment phase of cap-dependent translation. This heterotrimeric complex consists of a cap binding subunit (eIF4E), a DEAD-box RNA helicase (eIF4A), and a large bridging protein (eIF4G). In mammalian cells, there are two genes encoding eIF4A (eIF4A1 and eIF4A2) and eIF4G (eIF4G1 and eIF4G3) paralogs that can assemble into eIF4F complexes. To query the essential nature of the eIF4F subunits in normal development, we used CRISPR/Cas9 to generate mouse strains with targeted ablation of each gene encoding the different eIF4F subunits. We find that Eif4e, Eif4g1, and Eif4a1 are essential for viability in the mouse, whereas Eif4g3 and Eif4a2 are not. However, Eif4g3 and Eif4a2 do play essential roles in spermatogenesis. Crossing of these strains to the lymphoma-prone Eµ-Myc mouse model revealed that heterozygosity at the Eif4e or Eif4a1 loci significantly delayed tumor onset. Lastly, tumors derived from Eif4e∆38 fs/+/Eµ-Myc or Eif4a1∆5 fs/+/Eµ-Myc mice show increased sensitivity to the chemotherapeutic agent doxorubicin, in vivo. Our study reveals that eIF4A2 and eIF4G3 play non-essential roles in gene expression regulation during embryogenesis; whereas reductions in eIF4E or eIF4A1 levels are protective against tumor development in a murine Myc-driven lymphoma setting.


Asunto(s)
Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas/genética , Factor 4F Eucariótico de Iniciación/genética , Animales , Femenino , Regulación de la Expresión Génica/genética , Heterocigoto , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Subunidades de Proteína/genética , Espermatogénesis/genética
3.
Nucleic Acids Res ; 48(17): 9521-9537, 2020 09 25.
Artículo en Inglés | MEDLINE | ID: mdl-32766783

RESUMEN

Hippuristanol (Hipp) is a natural product that selectively inhibits protein synthesis by targeting eukaryotic initiation factor (eIF) 4A, a DEAD-box RNA helicase required for ribosome recruitment to mRNA templates. Hipp binds to the carboxyl-terminal domain of eIF4A, locks it in a closed conformation, and inhibits its RNA binding. The dependencies of mRNAs for eIF4A during initiation is contingent on the degree of secondary structure within their 5' leader region. Interest in targeting eIF4A therapeutically in cancer and viral-infected settings stems from the dependencies that certain cellular (e.g. pro-oncogenic, pro-survival) and viral mRNAs show towards eIF4A. Using a CRISPR/Cas9-based variomics screen, we identify functional EIF4A1 Hipp-resistant alleles, which in turn allowed us to link the translation-inhibitory and cytotoxic properties of Hipp to eIF4A1 target engagement. Genome-wide translational profiling in the absence or presence of Hipp were undertaken and our validation studies provided insight into the structure-activity relationships of eIF4A-dependent mRNAs. We find that mRNA 5' leader length, overall secondary structure and cytosine content are defining features of Hipp-dependent mRNAs.


Asunto(s)
Regiones no Traducidas 5' , Resistencia a Antineoplásicos/genética , Factor 4A Eucariótico de Iniciación/genética , Esteroles/farmacología , Sistemas CRISPR-Cas , Línea Celular Tumoral , Resistencia a Antineoplásicos/efectos de los fármacos , Factor 4A Eucariótico de Iniciación/antagonistas & inhibidores , Factor 4A Eucariótico de Iniciación/metabolismo , Humanos , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Mutación , Ribosomas/genética , Ribosomas/metabolismo
4.
Proc Natl Acad Sci U S A ; 116(16): 7857-7866, 2019 04 16.
Artículo en Inglés | MEDLINE | ID: mdl-30940748

RESUMEN

Protein synthesis is essential for cell growth, proliferation, and survival. Protein synthesis is a tightly regulated process that involves multiple mechanisms. Deregulation of protein synthesis is considered as a key factor in the development and progression of a number of diseases, such as cancer. Here we show that the dynamic modification of proteins by O-linked ß-N-acetyl-glucosamine (O-GlcNAcylation) regulates translation initiation by modifying core initiation factors eIF4A and eIF4G, respectively. Mechanistically, site-specific O-GlcNAcylation of eIF4A on Ser322/323 disrupts the formation of the translation initiation complex by perturbing its interaction with eIF4G. In addition, O-GlcNAcylation inhibits the duplex unwinding activity of eIF4A, leading to impaired protein synthesis, and decreased cell proliferation. In contrast, site-specific O-GlcNAcylation of eIF4G on Ser61 promotes its interaction with poly(A)-binding protein (PABP) and poly(A) mRNA. Depletion of eIF4G O-GlcNAcylation results in inhibition of protein synthesis, cell proliferation, and soft agar colony formation. The differential glycosylation of eIF4A and eIF4G appears to be regulated in the initiation complex to fine-tune protein synthesis. Our study thus expands the current understanding of protein synthesis, and adds another dimension of complexity to translational control of cellular proteins.


Asunto(s)
Glicosilación , Iniciación de la Cadena Peptídica Traduccional , Línea Celular Tumoral , Factor 4G Eucariótico de Iniciación/química , Factor 4G Eucariótico de Iniciación/metabolismo , Humanos , Modelos Moleculares , Neoplasias/química , Neoplasias/metabolismo , Proteínas de Unión a Poli(A)/química , Proteínas de Unión a Poli(A)/metabolismo , ARN Mensajero/química , ARN Mensajero/metabolismo
5.
J Hand Surg Am ; 47(10): 1020.e1-1020.e5, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-34373134

RESUMEN

Digital papillary adenocarcinoma (DPA) is a rare and aggressive tumor arising from the eccrine sweat glands. It is found on the hands and feet and most commonly occurs on the volar and distal finger tips. In this report, we describe a DPA in a 45-year-old woman who presented with a slowly enlarging mass on the dorsal aspect of her proximal ring finger. This report shows that DPA may clinically present as a relatively benign-appearing mass and in an atypical location. Surgical excision, followed by histologic and immunohistochemical evaluations of even benign-appearing digital masses, is important because this is the only way a DPA can be diagnosed.


Asunto(s)
Adenocarcinoma Papilar , Neoplasias Óseas , Neoplasias de las Glándulas Sudoríparas , Adenocarcinoma Papilar/patología , Adenocarcinoma Papilar/cirugía , Neoplasias Óseas/patología , Glándulas Ecrinas/patología , Femenino , Dedos/patología , Dedos/cirugía , Mano/patología , Mano/cirugía , Humanos , Persona de Mediana Edad , Neoplasias de las Glándulas Sudoríparas/patología , Neoplasias de las Glándulas Sudoríparas/cirugía
6.
Surg Endosc ; 34(7): 2980-2986, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-31482352

RESUMEN

BACKGROUND: Adnexal surgery is believed to be more complex in patients with prior hysterectomy; however, there is little data regarding surgical outcomes. Understanding of individualized risks improves counseling, informed consent, and preoperative planning. METHODS: We performed a retrospective cohort study with a control group; we evaluated 744 patients undergoing laparoscopic adnexal surgery at an academic tertiary care center from 2011 to 2015. Comparisons were made using Chi square, Fisher's exact, or Wilcoxon-rank sum tests. We used log-binomial regression to calculate risk ratio and 95% confidence interval. RESULTS: Patients with prior hysterectomy were more likely to have intraoperative or postoperative complications at the time of laparoscopic adnexal surgery when compared to patients without prior hysterectomy [17.7% vs. 10.2%, p = 0.02, risk ratio (RR) 1.7, 95% confidence interval (CI) 1.1-2.7]. Patients with prior hysterectomy were four times more likely to have intraoperative complications (3.2% vs. 0.8%, p = 0.047, RR 4.0, 95% CI 1.1-14.7), and five times more likely to have conversion to laparotomy (5.6% vs. 1.1%, p = 0.004, RR 5.0, 95% CI 1.8-14.0). Patients with prior hysterectomy were more likely to need additional procedures, including lysis of adhesions (69.4% vs. 26.0%, p < 0.001), ureterolysis (15.3% vs. 4.8%, p < 0.001), and cystoscopy (28.2% vs. 8.1%, p < 0.001). They had longer operative time [101.5 min (IQR 59.5-135.0) vs. 78.0 min (IQR 53.0-109.0, p < 0.001)], and were less likely to have outpatient surgery (56.5% vs. 84.8%, p < 0.01). Postoperative complications were also more common (15.3% vs. 9.4%, p = 0.046). CONCLUSIONS: Patients with prior hysterectomy were 70% more likely to have a complication at the time of laparoscopic adnexal surgery than patients without hysterectomy. Increased risk of complications in subsequent adnexal surgery may influence the informed consent process or decisions regarding ovarian conservation. Awareness of potential need for additional surgical procedures may guide availability of equipment, choice of operating site, or referral to an advanced pelvic surgeon.


Asunto(s)
Enfermedades de los Anexos/cirugía , Histerectomía , Complicaciones Intraoperatorias/etiología , Laparoscopía/métodos , Complicaciones Posoperatorias/etiología , Anexos Uterinos/cirugía , Adulto , Estudios de Casos y Controles , Conversión a Cirugía Abierta , Femenino , Humanos , Histerectomía/métodos , Laparoscopía/efectos adversos , Laparotomía/efectos adversos , Persona de Mediana Edad , Oportunidad Relativa , Tempo Operativo , Estudios Retrospectivos , Adherencias Tisulares/etiología , Resultado del Tratamiento , Uréter/cirugía
7.
J Am Chem Soc ; 141(32): 12891-12900, 2019 08 14.
Artículo en Inglés | MEDLINE | ID: mdl-31310112

RESUMEN

Rocaglates are a family of natural products isolated from the genus Aglaia which possess a highly substituted cyclopenta[b]benzofuran skeleton and inhibit cap-dependent protein synthesis. Rocaglates are attractive compounds due to their potential for inhibiting tumor cell maintenance in vivo by specifically targeting eukaryotic initiation factor 4A (eIF4A) and interfering with recruitment of ribosomes to mRNA. In this paper, we describe an intercepted retro-Nazarov reaction utilizing intramolecular tosyl migration to generate a reactive oxyallyl cation on the rocaglate skeleton. Trapping of the oxyallyl cation with a diverse range of nucleophiles has been used to generate over 50 novel amidino-rocaglate (ADR) and amino-rocaglate derivatives. Subsequently, these derivatives were evaluated for their ability to inhibit cap-dependent protein synthesis where they were found to outperform previous lead compounds including the rocaglate hydroxamate CR-1-31-B.


Asunto(s)
Amidinas/farmacología , Antineoplásicos/farmacología , Factor 4A Eucariótico de Iniciación/antagonistas & inhibidores , Compuestos Heterocíclicos de 4 o más Anillos/farmacología , Amidinas/síntesis química , Animales , Antineoplásicos/síntesis química , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales , Compuestos Heterocíclicos de 4 o más Anillos/síntesis química , Humanos , Ratones , Modelos Químicos , Estructura Molecular , Células 3T3 NIH , Relación Estructura-Actividad
8.
Diabetes Obes Metab ; 21(10): 2274-2283, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31168889

RESUMEN

AIMS: While recent cardiovascular safety trials (CVST) concerning newer diabetes medications included mostly white participants, results are being generalized to all races in recent guidelines. This raises a controversial question regarding the appropriateness of applying CVST data to black patients with type 2 diabetes. MATERIALS AND METHODS: We searched for randomized trials comparing diabetes medications to placebo in type 2 diabetes and investigated three- or four-point major adverse cardiovascular events (MACE). Data concerning black patients were then extracted. As the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) updated their recommendations for patients with established cardiovascular risk based on the CVST showing cardiovascular benefit, we performed a sensitivity analysis by including those trials only. RESULTS: A total of 11 trials were included, investigating a glucagon-like peptide-1 receptor agonist (GLP-1RA) in five, a sodium-glucose co-transporter-2 inhibitor (SGLT-2i) in two and dipeptidyl peptidase-4 inhibitors (DPP-4i) in four. Of the 102 416 participants enrolled in the included trials, only 4601 were black (4.5%). Pooled results showed no significant difference in the incidence of MACE among diabetes medications (GLP-1RA, SGLT-2i or DPP-4i) and placebo in black patients with type 2 diabetes (relative risk [RR] [95% CI], 0.94 [0.77,1.16]). Restricting the analysis to different classes of diabetes medication, the results remained non-significant. Restricting the analysis to CVST with significant outcomes, the results remained non-significant (RR [95% CI], 0.97 [0.68,1.39]). CONCLUSIONS: Given that black patients with type 2 diabetes were not well represented in CVSTs and such trials were underpowered to evaluate racial differences, it remains unclear whether GLP-1RAs or SGLT-2is would reduce cardiovascular risk in such patients, and additional studies targeting black patients are urgently needed.


Asunto(s)
Enfermedades Cardiovasculares , Diabetes Mellitus Tipo 2 , Receptor del Péptido 1 Similar al Glucagón/agonistas , Hipoglucemiantes/uso terapéutico , Inhibidores del Cotransportador de Sodio-Glucosa 2/uso terapéutico , Negro o Afroamericano/estadística & datos numéricos , Enfermedades Cardiovasculares/complicaciones , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/prevención & control , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/epidemiología , Inhibidores de la Dipeptidil-Peptidasa IV/uso terapéutico , Humanos , Estados Unidos
9.
Cell Mol Life Sci ; 74(9): 1681-1692, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28004147

RESUMEN

Biotherapeutics have revolutionized modern medicine by providing medicines that would not have been possible with small molecules. With respect to cancer therapies, this represents the current sector of the pharmaceutical industry having the largest therapeutic impact, as exemplified by the development of recombinant antibodies and cell-based therapies. In cancer, one of the most common regulatory alterations is the perturbation of translational control. Among these, changes in eukaryotic initiation factor 4F (eIF4F) are associated with tumor initiation, progression, and drug resistance in a number of settings. This, coupled with the fact that systemic suppression of eIF4F appears well tolerated, indicates that therapeutic agents targeting eIF4F hold much therapeutic potential. Here, we discuss opportunities offered by biologicals for this purpose.


Asunto(s)
Antineoplásicos/farmacología , Descubrimiento de Drogas , Factor 4F Eucariótico de Iniciación/antagonistas & inhibidores , Animales , Transformación Celular Neoplásica/metabolismo , Transformación Celular Neoplásica/patología , Factor 4F Eucariótico de Iniciación/metabolismo , Humanos , Virus Oncolíticos/efectos de los fármacos , Virus Oncolíticos/metabolismo , Biosíntesis de Proteínas/efectos de los fármacos
10.
RNA ; 21(10): 1826-33, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26286746

RESUMEN

MicroRNAs (miRNAs) are short noncoding RNAs that regulate gene expression through partial complementary base-pairing to the 3' untranslated region (UTR) of target mRNAs. Inhibition of translation initiation has been identified as an early event of miRNA-mediated gene repression, but the underlying mechanistic details of this process are not well understood. Recently, eukaryotic initiation factor (eIF) 4AII was identified as a critical modulator of miRNA activity with depletion of this factor alleviating miRNA-mediated gene repression. Using the CRISPR/Cas9-editing system, we generated a novel cell line in which expression of eIF4AII was eliminated. The absence of eIF4AII does not affect cell viability, proliferation, or global mRNA translation. Importantly, we show that eIF4AII is dispensable for miRNA-mediated gene silencing.


Asunto(s)
Factor 4A Eucariótico de Iniciación/fisiología , Silenciador del Gen/fisiología , MicroARNs/fisiología , Animales , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Ratones , Células 3T3 NIH
11.
Biochim Biophys Acta ; 1849(7): 781-91, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25234619

RESUMEN

Protein synthesis is an essential cellular process that is highly responsive to extra- and intracellular cues such as mitogens, growth signals, nutrient and energy status, and stress. Much regulation of translation is directed towards initiation, more specifically the ribosome recruitment phase which requires the eukaryotic initiation factor (eIF) 4F complex to prepare the mRNA for the incoming 40S ribosome (and associated factors). As many commonly deregulated signaling pathways found in cancers converge to influence protein synthesis, targeting factors involved in translation initiation is a viable anti-neoplastic strategy that has demonstrated success in pre-clinical settings. Furthermore, transcripts that are particularly sensitive to fluctuations in levels of the eIF4F complex are often associated with oncogenic characteristics (eg proliferation, survival, and angiogenesis) and their translational output appears to be preferentially reduced when eIF4F is inhibited. In particular, the enzymatic subunit of the eIF4F complex, eIF4A, has been extensively explored as a druggable target with several natural products identified as potent and selective inhibitors. In this review, we discuss the cellular regulation of eIF4A activity and its potential as a therapeutic target. This article is part of a Special Issue entitled: Translation and Cancer.


Asunto(s)
Inhibidores Enzimáticos/uso terapéutico , Factor 4A Eucariótico de Iniciación/antagonistas & inhibidores , Proteínas de Neoplasias/antagonistas & inhibidores , Neoplasias/tratamiento farmacológico , ARN Helicasas/antagonistas & inhibidores , Animales , Factor 4A Eucariótico de Iniciación/genética , Factor 4A Eucariótico de Iniciación/metabolismo , Humanos , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Neoplasias/enzimología , Neoplasias/genética , Neoplasias/patología , ARN Helicasas/genética , ARN Helicasas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN Neoplásico/genética , ARN Neoplásico/metabolismo , Subunidades Ribosómicas Pequeñas de Eucariotas/genética , Subunidades Ribosómicas Pequeñas de Eucariotas/metabolismo
12.
J Cancer Educ ; 31(3): 602-4, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-25877466

RESUMEN

The quality and accuracy of health content posted on YouTube varies widely. To increase dissemination of evidence-based gynecologic cancer information to US YouTube users, the Centers for Disease Control and Prevention (CDC) sponsored two types of advertisements: (1) pre-roll videos that users had to watch for at least 5 s before seeing a video they selected and (2) keyword-targeted listings that appeared in search results when users entered terms related to gynecologic cancer. From July 2012 to November 2013, pre-roll videos were shown 9.2 million times, viewed (watched longer than the mandatory 5 s) 1.6 million times (17.6 %), and cost $0.09 per view. Keyword-targeted listings were displayed 15.3 million times, viewed (activated by users) 59,766 times (0.4 %), and cost $0.31 per view. CDC videos in advertisements played completely in 17.0 % of pre-roll video views and 44.4 % of keyword-targeted listing views. Advertisements on YouTube can disseminate evidence-based cancer information broadly with minimal cost.


Asunto(s)
Publicidad , Neoplasias de los Genitales Femeninos/prevención & control , Internet/estadística & datos numéricos , Aprendizaje , Medios de Comunicación Sociales/estadística & datos numéricos , Grabación en Video/estadística & datos numéricos , Femenino , Humanos
14.
Clin Orthop Relat Res ; 473(11): 3477-83, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26290344

RESUMEN

BACKGROUND: The thumb trapeziometacarpal joint is one of the most common sites of arthritic degeneration prompting specialty care. Surgical treatment algorithms are based on radiographic arthritic progression. However, the pain and disability attributable to trapeziometacarpal arthritis do not correlate with arthritic stage, and depression has independently predicted poorer self-rated hand function both at baseline and after treatment in patients' atraumatic hand conditions. QUESTIONS/PURPOSES: (1) Does thumb trapeziometacarpal osteoarthritis impact both self-perceived general health and hand function? (2) Do depression and other comorbid conditions differentially impact patient-rated hand function based on the presence or absence of symptomatic trapeziometacarpal arthritis? (3) How do disease-specific, patient demographics and comorbid conditions impact self-reported hand function in patients with trapeziometacarpal osteoarthritis? METHODS: This cross-sectional study compared patients with symptomatic trapeziometacarpal osteoarthritis (n = 47) with matched control subjects without a symptomatic hand condition (n = 47). All participants self-reported medical (including depression) and musculoskeletal comorbidities and completed the SF-36 and the Michigan Hand Questionnaire (MHQ). Bivariate statistical analyses contrasted the patients with trapeziometacarpal osteoarthritis to control subjects. Linear regression modeling determined the impact of subject demographic data, comorbidity burden, and examination findings on total MHQ scores in patients with trapeziometacarpal arthritis. RESULTS: Patients with scored trapeziometacarpal osteoarthritis indicated poorer perceived general health on the SF-36 categories of limitations resulting from physical health (52 ± 29 versus 71 ± 31, mean difference 19 [95% confidence interval {CI}, 7-31], p = 0.003) and limitations resulting from emotional problems (50 ± 27 versus 67 ± 50, mean difference 17 [95% CI, 3-33], p = 0.022) compared with control subjects. Self-reported depression was associated with worse hand function (total MHQ score) in patients with trapeziometacarpal arthritis (69 ± 20 versus 49 ± 22: mean difference -20 [95% CI, -5 to-36], p = 0.012) but not in control patients (90 ± 13 versus 84 ± 20: mean difference -5 [95% CI, -8 to 19], p = 0.404). In multivariate modeling, depression (ß -20, [95% CI, -5 to -34], p = 0.009) and upper extremity comorbidities (ß -25, [95% CI, -10 to -40], p = 0.002) were both associated with reduced total MHQ scores in patients with trapeziometacarpal osteoarthritis, and those factors accounted for 34% of the variance in the MHQ score. CONCLUSIONS: When interpreting patient-rated hand disability in patients presenting with symptomatic trapeziometacarpal osteoarthritis, scores should be interpreted after accounting for the presence of depression and upper extremity comorbidities. LEVEL OF EVIDENCE: Level III, prognostic study.


Asunto(s)
Artralgia/diagnóstico , Artritis/diagnóstico , Articulaciones Carpometacarpianas/fisiopatología , Autoinforme , Pulgar/fisiopatología , Anciano , Artralgia/epidemiología , Artralgia/fisiopatología , Artralgia/psicología , Artritis/epidemiología , Artritis/fisiopatología , Artritis/psicología , Distribución de Chi-Cuadrado , Comorbilidad , Costo de Enfermedad , Estudios Transversales , Depresión/epidemiología , Depresión/psicología , Femenino , Estado de Salud , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Missouri/epidemiología , Análisis Multivariante , New York/epidemiología , Dimensión del Dolor , Percepción , Valor Predictivo de las Pruebas , Factores de Riesgo , Índice de Severidad de la Enfermedad
15.
J Transl Med ; 12: 340, 2014 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-25491597

RESUMEN

BACKGROUND: Aldosterone synthase inhibition provides the potential to attenuate both the mineralocorticoid receptor-dependent and independent actions of aldosterone. In vitro studies with recombinant human enzymes showed LCI699 to be a potent, reversible, competitive inhibitor of aldosterone synthase (K i = 1.4 ± 0.2 nmol/L in humans) with relative selectivity over 11ß-hydroxylase. METHODS: Hormonal effects of orally administered LCI699 were examined in rat and monkey in vivo models of adrenocorticotropic hormone (ACTH) and angiotensin-II-stimulated aldosterone release, and were compared with the mineralocorticoid receptor antagonist eplerenone in a randomized, placebo-controlled study conducted in 99 healthy human subjects. The effects of LCI699 and eplerenone on cardiac and renal sequelae of aldosterone excess were investigated in a double-transgenic rat (dTG rat) model overexpressing human renin and angiotensinogen. RESULTS: Rat and monkey in vivo models of stimulated aldosterone release predicted human dose- and exposure-response relationships, but overestimated the selectivity of LCI699 in humans. In the dTG rat model, LCI699 dose-dependently blocked increases in aldosterone, prevented development of cardiac and renal functional abnormalities independent of blood pressure changes, and prolonged survival. Eplerenone prolonged survival to a similar extent, but was less effective in preventing cardiac and renal damage. In healthy human subjects, LCI699 0.5 mg selectively reduced plasma and 24 h urinary aldosterone by 49 ± 3% and 39 ± 6% respectively (Day 1, mean ± SEM; P < 0.001 vs placebo), which was associated with natriuresis and an increase in plasma renin activity. Doses of LCI699 greater than 1 mg inhibited basal and ACTH-stimulated cortisol. Eplerenone 100 mg increased plasma and 24 h urinary aldosterone while stimulating natriuresis and increasing renin activity. In contrast to eplerenone, LCI699 increased the aldosterone precursor 11-deoxycorticosterone and urinary potassium excretion. CONCLUSIONS: These results provide new insights into the cardiac and renal effects of inhibiting aldosterone synthase in experimental models and translation of the hormonal effects to humans. Selective inhibition of aldosterone synthase appears to be a promising approach to treat diseases associated with aldosterone excess.


Asunto(s)
Angiotensinógeno/fisiología , Citocromo P-450 CYP11B2/antagonistas & inhibidores , Modelos Animales de Enfermedad , Corazón/efectos de los fármacos , Riñón/efectos de los fármacos , Renina/fisiología , Investigación Biomédica Traslacional , Animales , Método Doble Ciego , Eplerenona , Haplorrinos , Corazón/fisiopatología , Humanos , Imidazoles/farmacología , Riñón/fisiopatología , Masculino , Placebos , Piridinas/farmacología , Ratas , Ratas Sprague-Dawley , Ratas Transgénicas , Espironolactona/análogos & derivados , Espironolactona/farmacología
16.
Clin Orthop Relat Res ; 472(4): 1190-7, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24249530

RESUMEN

BACKGROUND: There are a variety of postoperative immobilization and therapy options for patients with basal joint arthritis. Although prior systematic reviews have compared surgical procedures used to treat basal joint arthritis, none to our knowledge compares therapy protocols for this condition, which are considered an important part of the treatment. QUESTIONS/PURPOSES: (1) We sought to determine whether differences in the length and type of postoperative immobilization affect clinical results after basal joint arthritis surgery. (2) We also compared specific therapy protocols that were prescribed. (3) Finally, we evaluated published protocols to determine when patients were released to full activity to see whether these appeared to affect clinical results. METHODS: A systematic review of English-language studies in the PubMed and Cochrane databases was performed. Studies were then reviewed to determine what postoperative immobilization and therapy protocols the authors used and when patients were released to full activities. A total of 19 studies were identified using the search criteria. RESULTS: All but one of the studies included a postoperative period of immobilization in either a cast or splint. Immobilization time varied depending on whether Kirschner wires were used for the surgery and whether an implant was placed. Postoperative therapy protocols also varied but followed three general patterns. Some therapy protocols involved teaching patients a home exercise program only, whereas some authors described routine referral to a therapist. The third group consisted of studies in which patients were only referred for therapy if the physicians determined it was necessary during followup. Many studies did not give a specific time for full return to activity and instead described a gradual transition to full activity after immobilization was discontinued. Because of the variability and small numbers, no conclusive recommendations could be made on any of the three study questions. CONCLUSIONS: Comparative, multicenter studies comparing different immobilization and therapy protocols after the surgical treatment of basal joint arthritis would be helpful for both surgeons and therapists looking to refine their treatment protocols.


Asunto(s)
Artritis/cirugía , Articulaciones Carpometacarpianas/cirugía , Fijación de Fractura , Procedimientos Ortopédicos/métodos , Modalidades de Fisioterapia , Hueso Trapecio/cirugía , Artritis/fisiopatología , Fenómenos Biomecánicos , Hilos Ortopédicos , Articulaciones Carpometacarpianas/fisiopatología , Moldes Quirúrgicos , Fijación de Fractura/instrumentación , Humanos , Procedimientos Ortopédicos/efectos adversos , Procedimientos Ortopédicos/instrumentación , Cuidados Posoperatorios , Recuperación de la Función , Férulas (Fijadores) , Factores de Tiempo , Hueso Trapecio/fisiopatología , Resultado del Tratamiento
17.
J Man Manip Ther ; 22(4): 220-9, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25395830

RESUMEN

OBJECTIVES: Spinal manual therapy (SMT) is commonly used for treatment of musculoskeletal pain in the neck, upper back, or upper extremity. Some authors report a multi-system effect of SMT, including peripheral alterations in skin conductance and skin temperature, suggesting that SMT may initiate a sympathetic nervous system (SNS) response. The focus of this evidence-based review and meta-analysis is to evaluate the evidence of SNS responses and clinically relevant outcomes following SMT to the cervical or thoracic spine. METHODS: A SYSTEMATIC SEARCH USED THE TERMS: 'manual therapy', 'SMT', 'spinal manipulation', 'mobilization', 'SNS', 'autonomic nervous system', 'neurophysiology', 'hypoalgesia', 'pain pathophysiology', 'cervical vertebrae', 'thoracic vertebrae', 'upper extremity', and 'neurodynamic test'. Data were extracted and within-group and between-group effect sizes were calculated for outcomes of skin conductance, skin temperature, pain, and upper extremity range of motion (ROM) during upper limb neurodynamic tests (ULNTs). RESULTS: Eleven studies were identified. Statistically significant changes were seen with increased skin conductance, decreased skin temperature, decreased pain, and increased upper extremity ROM during ULNT. DISCUSSION: A mechanical stimulus at the cervical or thoracic spine can produce a SNS excitatory response (increased skin conductance and decreased skin temperature). Findings of reduced pain and increased ROM during ULNT provide support to the clinical relevance of SMT. This evidence points toward additional mechanisms underlying the therapeutic effect of SMT. The effect sizes are small to moderate and no long-term effects post-SMT were collected. Future research is needed to associate peripheral effects with a possible centrally-mediated response to SMT.

18.
J Hand Surg Am ; 38(6): 1084-90, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23578439

RESUMEN

PURPOSE: One goal in repairing zone 1 flexor digitorum profundus (FDP) injuries is to create a tendon-bone construct strong enough to allow early rehabilitation while minimizing morbidity. This study compares an all-inside suture repair technique biomechanically with pull-out suture and double-suture anchor repairs. METHODS: Repairs were performed on 30 cadaver fingers. In all-inside suture repairs (n = 8), the FDP tendon was attached to bone with two 3-0 Ethibond sutures and tied over the dorsal aspect of distal phalanx. Pull-out suture repairs (n = 8) were performed with 2-0 Prolene suture and tied over a dorsal button. There were 2 suture anchor repair groups: Arthrex Micro Corkscrew anchors preloaded with 2-0 FiberWire suture (n = 7) and Depuy Micro Mitek anchors preloaded with 3-0 Orthocord suture (n = 7). Repair constructs were tested using a servohydraulic materials testing system and loaded until the repair lost 75% of its strength. RESULTS: There were no statistically significant differences in tensile stiffness, ultimate load, or work to failure between the repairs. Failure mode was suture stretch and gap formation greater than 2 mm at the repair site for all pull-out suture repairs and for 7 of 8 all-inside suture repairs. Two of the Arthrex Micro Corkscrew repairs and 5 of the Depuy Micro Mitek repairs failed by anchor pull-out. CONCLUSIONS: This cadaveric biomechanical study showed no difference in tensile stiffness, ultimate load, and work to failures between an all-inside suture repair technique for zone 1 FDP repairs and previously described pull-out suture and suture anchor repair techniques. The all-inside suture technique also has the advantages of avoiding an external button and the cost of anchors. Therefore, it should be considered as an alternative to other techniques. CLINICAL RELEVANCE: This study introduces a new FDP reattachment technique that avoids some of the shortcomings of current techniques.


Asunto(s)
Traumatismos de los Dedos/cirugía , Anclas para Sutura , Técnicas de Sutura , Traumatismos de los Tendones/cirugía , Fenómenos Biomecánicos , Humanos , Tereftalatos Polietilenos , Suturas , Resistencia a la Tracción
19.
Health Promot Pract ; 14(5): 656-62, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23720533

RESUMEN

Donated media placements for public service announcements (PSAs) can be difficult to secure, and may not always reach intended audiences. Strategies used by the Centers for Disease Control and Prevention's (CDC) Screen for Life: National Colorectal Cancer Action Campaign (SFL) to obtain donated media placements include producing a diverse mix of high-quality PSAs, co-branding with state and tribal health agencies, securing celebrity involvement, monitoring media trends to identify new distribution opportunities, and strategically timing the release of PSAs. To investigate open-ended recall of PSAs promoting colorectal cancer screening, CDC conducted 12 focus groups in three U.S. cities with men and women either nearing age 50 years, when screening is recommended to begin, or aged 50-75 years who were not in compliance with screening guidelines. In most focus groups, multiple participants recalled exposure to PSAs promoting colorectal cancer screening, and most of these individuals reported having seen SFL PSAs on television, in transit stations, or on the sides of public buses. Some participants reported exposure to SFL PSAs without prompting from the moderator, as they explained how they learned about the disease. Several participants reported learning key campaign messages from PSAs, including that colorectal cancer screening should begin at age 50 years and screening can find polyps so they can be removed before becoming cancerous. Donated media placements can reach and educate mass audiences, including millions of U.S. adults who have not been screened appropriately for colorectal cancer.


Asunto(s)
Neoplasias Colorrectales/diagnóstico , Detección Precoz del Cáncer , Promoción de la Salud/organización & administración , Medios de Comunicación de Masas/economía , Anciano , Centers for Disease Control and Prevention, U.S. , Servicios de Salud Comunitaria/organización & administración , Femenino , Grupos Focales , Promoción de la Salud/economía , Humanos , Masculino , Persona de Mediana Edad , Características de la Residencia , Factores Socioeconómicos , Factores de Tiempo , Estados Unidos
20.
Cell Rep ; 42(10): 113223, 2023 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-37805921

RESUMEN

Pre-mRNA splicing is surveilled at different stages by quality control (QC) mechanisms. The leukemia-associated DExH-box family helicase hDHX15/scPrp43 is known to disassemble spliceosomes after splicing. Here, using rapid protein depletion and analysis of nascent and mature RNA to enrich for direct effects, we identify a widespread splicing QC function for DHX15 in human cells, consistent with recent in vitro studies. We find that suboptimal introns with weak splice sites, multiple branch points, and cryptic introns are repressed by DHX15, suggesting a general role in promoting splicing fidelity. We identify SUGP1 as a G-patch factor that activates DHX15's splicing QC function. This interaction is dependent on both DHX15's ATPase activity and on SUGP1's U2AF ligand motif (ULM) domain. Together, our results support a model in which DHX15 plays a major role in splicing QC when recruited and activated by SUGP1.


Asunto(s)
Empalme del ARN , Empalmosomas , Humanos , ARN/metabolismo , ARN Helicasas/genética , ARN Helicasas/metabolismo , Precursores del ARN/genética , Precursores del ARN/metabolismo , Empalme del ARN/genética , Factores de Empalme de ARN/genética , Factores de Empalme de ARN/metabolismo , Empalmosomas/metabolismo , Factor de Empalme U2AF/metabolismo
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