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1.
Pediatr Dev Pathol ; 27(1): 67-76, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37771167

RESUMEN

Lymphoma is the fourth most common tumor to display placental metastasis. This study aimed to report a case of high-grade lymphoma involving the placenta and review the literature on lymphomas metastatic to the placenta. A systematic review was performed following the PRISMA guidelines, using the keywords "lymphoma" AND "placenta." All case reports and case series on lymphoma infiltrating the placenta were collected. Eight cases from 7 studies, including the present case, were synthesized. The mean patient age is 29.5 years. The clinical presentation is non-specific. Hematologic derangements included cytopenias or cytoses, and elevated prothrombin time. The mean gestational age (GA) when a diagnosis of lymphoma was rendered is 27 weeks. Five cases presented with either lymphadenopathy or visceral masses on imaging. Four of these cases eventually led to maternal demise. The mean GA when the fetus was delivered is 31 3/4 weeks. Grossly, most placentas had non-specific findings. Leukemic infiltrates were mostly seen within intervillous spaces. Intravillous infiltrates were associated with high-grade lymphomas, resulting in either maternal demise or stillborn fetuses. This study suggests that the placenta has mechanisms to guard against malignancies; however, these defense mechanisms are not foolproof and may be breached by tumor cells.


Asunto(s)
Linfoma , Neoplasias , Enfermedades Placentarias , Embarazo , Femenino , Humanos , Adulto , Lactante , Placenta/patología , Enfermedades Placentarias/patología , Neoplasias/patología , Feto/patología , Linfoma/diagnóstico , Linfoma/patología
2.
Prehosp Emerg Care ; 28(2): 200-208, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-36730082

RESUMEN

OBJECTIVE: The objective of this study was to determine the effect of transitioning from direct laryngoscopy (DL) to video laryngoscopy (VL) on endotracheal intubation success overall and with enhanced precautions implemented during the COVID-19 pandemic. METHODS: We examined electronic transport records from Mayo Clinic Ambulance Service, a large advanced life support (ALS) provider serving rural, suburban, and urban areas in Minnesota and Wisconsin, USA. We determined the success of intubation attempts when using DL (March 10, 2018 to December 19, 2019), VL (December 20, 2019 to September 29, 2021), and VL with an enhanced COVID-19 guideline that restricted intubation to one attempt, performed by the most experienced clinician, who wore enhanced personal protective equipment (April 1 to December 18, 2020). Success rates at first attempt and after any attempt were assessed for association with type of laryngoscopy (VL vs DL) after adjusting for patient age group, patient weight, use of enhanced COVID-19 guideline, medical vs trauma patient, and ALS vs critical care clinician. A secondary analysis further adjusted for degree of glottic visualization. RESULTS: We identified 895 intubation attempts using DL and 893 intubation attempts using VL, which included 382 VL intubation attempts using the enhanced COVID-19 guideline. Success on first intubation attempt was 69.2% for encounters with DL, 82.9% overall with VL, and 83.2% with VL and enhanced COVID-19 protocols (DL vs overall VL: p < 0.001; COVID-19 vs non-COVID VL: p = 0.86). In multivariable analysis, use of VL was associate with higher odds of successful intubation on first attempt (odds ratio, 2.28; 95%CI, 1.73-3.01; p < 0.001) and on any attempt (odds ratio, 2.16; 95%CI, 1.58-2.96; p < 0.001) compared with DL. Inclusion of glottic visualization in the model resulted in a nonsignificant association between laryngoscopy type and successful first intubation (p = 0.41) and a significant association with the degree of glottic visualization (p < 0.001). CONCLUSIONS: VL is designed to improve glottic visualization. The use of VL by a large, U.S. multistate ALS ambulance service was associated with increased odds of successful first-pass and overall attempted intubation, which was mediated by better visualization of the glottis. COVID-19 protocols were not associated with success rates.


Asunto(s)
COVID-19 , Servicios Médicos de Urgencia , Laringoscopios , Humanos , COVID-19/epidemiología , Servicios Médicos de Urgencia/métodos , Intubación Intratraqueal/métodos , Laringoscopía/métodos , Pandemias , Grabación en Video
3.
Anesth Analg ; 2023 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-38009837

RESUMEN

Obesity is often considered a contraindication to extracorporeal membrane oxygenation (ECMO) candidacy due to technical challenges with vascular access, higher cardiac output requirements, and known associations between obesity and overall increased morbidity and mortality due to chronic health conditions. However, a growing body of literature suggests that ECMO may be as safe and efficacious in both obese and nonobese patients. This scoping review provides a synthesis of the available literature on the outcomes of obese patients supported with (1) venovenous (VV)-ECMO in acute respiratory distress syndrome (ARDS) not due to coronavirus disease 2019 (COVID-19), (2) VV-ECMO in ARDS due to COVID-19, (3) venoarterial (VA)-ECMO for all indications, and (4) studies combining data of patients supported with VA- and VV-ECMO. A librarian-assisted search was performed using 4 primary electronic medical databases (PubMed, Web of Science, Excerpta Medica database [Embase], and Cochrane Library) from January 2003 to March 2023. Articles that reported outcomes of obese patients requiring ECMO support were included. Two reviewers independently screened titles, abstracts, and full text of articles to determine eligibility. Data extraction was performed using customized fields established a priori within a systematic review software system. A total of 354 publications were imported for screening on titles and abstracts, and 30 studies were selected for full-text review. A total of 26 publications met the inclusion criteria: 7 on VV-ECMO support in non-COVID-19 ARDS patients, 6 on ECMO in COVID-19 ARDS patients, 8 in patients supported with VA-ECMO, and 5 combining both VA- and VV-ECMO data. Although the included studies are limited to retrospective analyses and display a heterogeneity in definitions of obesity and comparison groups, the currently available literature suggests that outcomes and complications of ECMO therapy are equivalent in obese patients as compared to nonobese patients. Hence, obesity as measured by body mass index alone should not be considered an exclusion criterion in the decision to initiate ECMO.

4.
Chemistry ; 27(68): 17240-17254, 2021 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-34608688

RESUMEN

We present a mechanistic study on the formation of an active ligand layer over Pd(111), turning the catalytic surface highly active and selective in partial hydrogenation of an α,ß-unsaturated aldehyde acrolein. Specifically, we investigate the chemical composition of a ligand layer consisting of allyl cyanide deposited on Pd(111) and its dynamic changes under the hydrogenation conditions. On pristine surface, allyl cyanide largely retains its chemical structure and forms a layer of molecular species with the CN bond oriented nearly parallel to the underlying metal. In the presence of hydrogen, the chemical composition of allyl cyanide strongly changes. At 100 K, allyl cyanide transforms to unsaturated imine species, containing the C=C and C=N double bonds. At increasing temperatures, these species undergo two competing reaction pathways. First, the C=C bond become hydrogenated and the stable N-butylimine species are produced. In the competing pathway, the unsaturated imine reacts with hydrogen to fully hydrogenate the imine group and produce butylamine. The latter species are unstable under the hydrogenation reaction conditions and desorb from the surface, while the N-butylimine adsorbates formed in the first reaction pathway remain adsorbed and act as an active ligand layer in selective hydrogenation of acrolein.

5.
Angew Chem Int Ed Engl ; 60(30): 16349-16354, 2021 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-34008906

RESUMEN

We present a mechanistic study on the formation and dynamic changes of a ligand-based heterogeneous Pd catalyst for chemoselective hydrogenation of α,ß-unsaturated aldehyde acrolein. Deposition of allyl cyanide as a precursor of a ligand layer renders Pd highly active and close to 100 % selective toward propenol formation by promoting acrolein adsorption in a desired configuration via the C=O end. Employing a combination of real-space microscopic and in-operando spectroscopic surface-sensitive techniques, we show that an ordered active ligand layer is formed under operational conditions, consisting of stable N-butylimine species. In a competing process, unstable amine species evolve on the surface, which desorb in the course of the reaction. Obtained atomistic-level insights into the formation and dynamic evolution of the active ligand layer under operational conditions provide important input required for controlling chemoselectivity by purposeful surface functionalization.

6.
Mol Pharmacol ; 97(1): 2-8, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31704717

RESUMEN

The thyrotropin (TSH) receptor (TSHR) signals via G proteins of all four classes and ß-arrestin 1. Stimulation of TSHR leads to increasing cAMP production that has been reported as a monotonic dose-response curve that plateaus at high TSH doses. In HEK 293 cells overexpressing TSHRs (HEK-TSHR cells), we found that TSHR activation exhibits an "inverted U-shaped dose-response curve" with increasing cAMP production at low doses of TSH and decreased cAMP production at high doses (>1 mU/ml). Since protein kinase A inhibition by H-89 and knockdown of ß-arrestin 1 or ß-arrestin 2 did not affect the decreased cAMP production at high TSH doses, we studied the roles of TSHR downregulation and of Gi/Go proteins. A high TSH dose (100 mU/ml) caused a 33% decrease in cell-surface TSHR. However, because inhibiting TSHR downregulation with combined expression of a dominant negative dynamin 1 and ß-arrestin 2 knockdown had no effect, we concluded that downregulation is not involved in the biphasic cAMP response. Pertussis toxin, which inhibits activation of Gi/Go, abolished the biphasic response with no statistically significant difference in cAMP levels at 1 and 100 mU/ml TSH. Concordantly, co-knockdown of Gi/Go proteins increased cAMP levels stimulated by 100 mU/ml TSH from 55% to 73% of the peak level. These data show that biphasic regulation of cAMP production is mediated by Gs and Gi/Go at low and high TSH doses, respectively, which may represent a mechanism to prevent overstimulation in TSHR-expressing cells. SIGNIFICANCE STATEMENT: We demonstrate biphasic regulation of TSH-mediated cAMP production involving coupling of the TSH receptor (TSHR) to Gs at low TSH doses and to Gi/o at high TSH doses. We suggest that this biphasic cAMP response allows the TSHR to mediate responses at lower levels of TSH and that decreased cAMP production at high doses may represent a mechanism to prevent overstimulation of TSHR-expressing cells. This mechanism could prevent chronic stimulation of thyroid gland function.


Asunto(s)
AMP Cíclico/metabolismo , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/metabolismo , Receptores de Tirotropina/metabolismo , Transducción de Señal/efectos de los fármacos , Tirotropina/administración & dosificación , Relación Dosis-Respuesta a Droga , Regulación hacia Abajo , Dinamina I/genética , Dinamina I/metabolismo , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/antagonistas & inhibidores , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/genética , Técnicas de Silenciamiento del Gen , Células HEK293 , Humanos , Toxina del Pertussis/administración & dosificación , Receptores de Tirotropina/genética , Transducción de Señal/genética , Arrestina beta 2/genética , Arrestina beta 2/metabolismo
7.
J Surg Res ; 251: 94-99, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32114214

RESUMEN

BACKGROUND: Venous thromboembolism (VTE) affects an estimated 350,000 to 600,000 individuals and causes approximately 100,000 deaths annually in the United States. Postoperative VTE is a core measure reported by The American College of Surgeons' National Surgical Quality Improvement Program (NSQIP). The objective of this research was to assess the validity of VTE events reported by NSQIP. MATERIALS AND METHODS: This is a retrospective analysis using NSQIP data from January 2006 through December 2018 and the electronic health record system data from five adult hospitals in the Johns Hopkins Health System. We included patients aged 18 years and older with a VTE event identified in our NSQIP data set. The main outcome measure was the proportion of valid VTE events, defined as concordant between the NSQIP data set and medical chart review for clinical documentation. RESULTS: Of 474 patients identified in our NSQIP database with a VTE, 26 (5.5%) did not meet the strict NSQIP definition of VTE. Nine had a preoperative history of DVT and no new postoperative event, seven had a negative workup for VTE, six had a peripheral arterial thrombus, two did not receive or refused therapy, one had an aortic thrombus, and one had a venous thrombosis in a surgical flap. CONCLUSIONS: We identified a considerable number of surgical patients misclassified as having a VTE in NSQIP, when did not truly. This highlights the need to improve definition specificity and standardize processes involved in data extraction, validation, and reporting to provide unbiased data for use in quality improvement.


Asunto(s)
Complicaciones Posoperatorias , Mejoramiento de la Calidad/normas , Tromboembolia Venosa , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
8.
Phys Chem Chem Phys ; 22(27): 15696-15706, 2020 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-32618972

RESUMEN

A mechanistic study on interaction of a chiral modifier - (R)-(+)-1-(1-naphthylethylamine) (R-NEA) - with a single crystalline Pt(111) surface is reported. The details of the adsorption geometry of individual R-NEA molecules and their intermolecular interactions are addressed by combination of infrared reflection absorption spectroscopy (IRAS) and scanning tunneling microscopy (STM). The spectroscopic observations suggest that the molecules are tilted with respect to the underlying metal substrate with the long axis of the naphthyl ring being parallel and the short axis tilted with respect to the surface. In the medium coverage range, formation of directed 3-5 membered chains was observed by STM for the first time, which points to intermolecular bonding between individual molecules and might account for an unusual tilted adsorption geometry deduced from the IR spectra. Based on the STM images revealing the atomic structure of the Pt grid close to the R-NEA chains, we propose the adsorption configuration of NEA fitting both the IRAS and STM data. The obtained results suggest that this strong intermolecular interaction energetically stabilizes the tilted adsorption geometry of the naphthyl ring, which otherwise would be expected to lie flat on the metal to maximize the dispersive interactions. At the coverage close to saturation, R-NEA builds a self-assembled overlayer with hexagonal symmetry, exhibiting intermolecular distances larger than in the directed chains.

9.
Int J Mol Sci ; 21(18)2020 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-32911689

RESUMEN

In this review, we summarize the evidence against direct stimulation of insulin-like growth factor 1 receptors (IGF1Rs) by autoantibodies in Graves' orbitopathy (GO) pathogenesis. We describe a model of thyroid-stimulating hormone (TSH) receptor (TSHR)/IGF1R crosstalk and present evidence that observations indicating IGF1R's role in GO could be explained by this mechanism. We evaluate the evidence for and against IGF1R as a direct target of stimulating IGF1R antibodies (IGF1RAbs) and conclude that GO pathogenesis does not involve directly stimulating IGF1RAbs. We further conclude that the preponderance of evidence supports TSHR as the direct and only target of stimulating autoantibodies in GO and maintain that the TSHR should remain a major target for further development of a medical therapy for GO in concert with drugs that target TSHR/IGF1R crosstalk.


Asunto(s)
Oftalmopatía de Graves/patología , Receptor IGF Tipo 1/inmunología , Receptores de Tirotropina/metabolismo , Autoanticuerpos/inmunología , Oftalmopatía de Graves/inmunología , Humanos , Ácido Hialurónico/metabolismo , Receptor Cross-Talk/inmunología , Receptor IGF Tipo 1/metabolismo , Receptores de Somatomedina , Receptores de Tirotropina/inmunología
10.
J Biol Chem ; 292(37): 15434-15444, 2017 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-28743746

RESUMEN

The thyroid gland secretes primarily tetraiodothyronine (T4), and some triiodothyronine (T3). Under normal physiological circumstances, only one-fifth of circulating T3 is directly released by the thyroid, but in states of hyperactivation of thyroid-stimulating hormone receptors (TSHRs), patients develop a syndrome of relative T3 toxicosis. Thyroidal T4 production results from iodination of thyroglobulin (TG) at residues Tyr5 and Tyr130, whereas thyroidal T3 production may originate in several different ways. In this study, the data demonstrate that within the carboxyl-terminal portion of mouse TG, T3 is formed de novo independently of deiodination from T4 We found that upon iodination in vitro, de novo T3 formation in TG was decreased in mice lacking TSHRs. Conversely, de novo T3 that can be formed upon iodination of TG secreted from PCCL3 (rat thyrocyte) cells was augmented from cells previously exposed to increased TSH, a TSHR agonist, a cAMP analog, or a TSHR-stimulating antibody. We present data suggesting that TSH-stimulated TG phosphorylation contributes to enhanced de novo T3 formation. These effects were reversed within a few days after removal of the hyperstimulating conditions. Indeed, direct exposure of PCCL3 cells to human serum from two patients with Graves' disease, but not control sera, led to secretion of TG with an increased intrinsic ability to form T3 upon in vitro iodination. Furthermore, TG secreted from human thyrocyte cultures hyperstimulated with TSH also showed an increased intrinsic ability to form T3 Our data support the hypothesis that TG processing in the secretory pathway of TSHR-hyperstimulated thyrocytes alters the structure of the iodination substrate in a way that enhances de novo T3 formation, contributing to the relative T3 toxicosis of Graves' disease.


Asunto(s)
Procesamiento Proteico-Postraduccional , Receptores de Tirotropina/agonistas , Transducción de Señal , Tiroglobulina/metabolismo , Células Epiteliales Tiroideas/metabolismo , Tirotropina/metabolismo , Triyodotironina/biosíntesis , Animales , Proteínas de Unión al Calcio/agonistas , Proteínas de Unión al Calcio/genética , Proteínas de Unión al Calcio/metabolismo , Quinasa de la Caseína I/genética , Quinasa de la Caseína I/metabolismo , Línea Celular , Células Cultivadas , Proteínas de la Matriz Extracelular/agonistas , Proteínas de la Matriz Extracelular/genética , Proteínas de la Matriz Extracelular/metabolismo , Enfermedad de Graves/sangre , Enfermedad de Graves/metabolismo , Enfermedad de Graves/patología , Halogenación , Humanos , Ratones Endogámicos C57BL , Ratones Noqueados , Fosforilación , Proteínas Serina-Treonina Quinasas/química , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Ratas , Receptores de Tirotropina/genética , Receptores de Tirotropina/metabolismo , Células Epiteliales Tiroideas/citología , Células Epiteliales Tiroideas/patología , Tirosina/metabolismo , Regulación hacia Arriba
11.
J Pharmacol Exp Ther ; 364(1): 38-45, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29089368

RESUMEN

Recently, we showed that TSH-enhanced differentiation of a human preosteoblast-like cell model involved a ß-arrestin 1 (ß-Arr 1)-mediated pathway. To study this pathway in more detail, we sought to discover a small molecule ligand that was functionally selective toward human TSH receptor (TSHR) activation of ß-Arr 1. High-throughput screening using a cell line stably expressing mutated TSHRs and mutated ß-Arr 1 (DiscoverX1 cells) led to the discovery of agonists that stimulated translocation of ß-Arr 1 to the TSHR, but did not activate Gs-mediated signaling pathways, i.e., cAMP production. D3-ßArr (NCGC00379308) was selected. In DiscoverX1 cells, D3-ßArr stimulated ß-Arr 1 translocation with a 5.1-fold greater efficacy than TSH and therefore potentiated the effect of TSH in stimulating ß-Arr 1 translocation. In human U2OS-TSHR cells expressing wild-type TSHRs, which is a model of human preosteoblast-like cells, TSH upregulated the osteoblast-specific genes osteopontin (OPN) and alkaline phosphatase (ALPL). D3-ßArr alone had only a weak effect to upregulate these bone markers, but D3-ßArr potentiated TSH-induced upregulation of ALPL and OPN mRNA levels 1.6-fold and 5.5-fold, respectively, at the maximum dose of ligands. Furthermore, the positive allosteric modulator effect of D3-ßArr resulted in an increase of TSH-induced secretion of OPN protein. In summary, we have discovered the first small molecule positive allosteric modulator of TSHR. As D3-ßArr potentiates the effect of TSH to enhance differentiation of a human preosteoblast in an in vitro model, it will allow a novel experimental approach for probing the role of TSH-induced ß-Arr 1 signaling in osteoblast differentiation.


Asunto(s)
Diferenciación Celular/efectos de los fármacos , Descubrimiento de Drogas/métodos , Osteoblastos/efectos de los fármacos , Receptores de Tirotropina/agonistas , Tirotropina/farmacología , Regulación Alostérica/efectos de los fármacos , Regulación Alostérica/fisiología , Animales , Células CHO , Diferenciación Celular/fisiología , Línea Celular Tumoral , Células Cultivadas , Cricetinae , Cricetulus , Ensayos Analíticos de Alto Rendimiento/métodos , Humanos , Osteoblastos/fisiología , Receptores de Tirotropina/fisiología , Células Epiteliales Tiroideas/efectos de los fármacos , Células Epiteliales Tiroideas/metabolismo , Tirotropina/análogos & derivados
12.
Bioelectromagnetics ; 39(3): 173-189, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29418010

RESUMEN

Exposures to radiofrequency (RF) energy above 6 GHz are characterized by shallow energy penetration, typically limited to the skin, but the subsequent increase in skin temperature is largely determined by heat transport in subcutaneous layers. A detailed analysis of the energy reflection, absorption, and power density distribution requires a knowledge of the properties of the skin layers and their variations. We consider an anatomically detailed model consisting of 3 or 4 layers (stratum corneum, viable epidermis plus dermis, subcutaneous fat, and muscle). The distribution of absorbed power in the different tissue layers is estimated based on electrical properties of the tissue layers inferred from measurements of reflected millimeter wavelength energy from skin, and literature data for the electrical properties of fat and muscle. In addition, the thermal response of the model is obtained using Pennes bioheat equation as well as a modified version incorporating blood flow rate-dependent thermal conductivity that provides a good fit to experimentally-found temperature elevations. A greatly simplified 3-layer model (Dermis, Fat, and Muscle) that assumes surface heating in only the skin layer clarifies the contribution of different tissue layers to the increase in surface skin temperature. The model shows that the increase in surface temperature is, under many circumstances, determined by the thermal resistance of subcutaneous tissues even though the RF energy may be deposited almost entirely in the skin layer. The limits of validity of the models and their relevance to setting safety standards are briefly discussed. Bioelectromagnetics. 39:173-189, 2018. © 2018 Wiley Periodicals, Inc.


Asunto(s)
Exposición a la Radiación/efectos adversos , Ondas de Radio/efectos adversos , Piel/efectos de la radiación , Absorción de Radiación , Humanos , Piel/citología , Temperatura Cutánea/efectos de la radiación
13.
Pharmacol Res ; 124: 1-8, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28720519

RESUMEN

Fatigue affects most cancer patients and has numerous potential causes, including cancer itself and cancer treatment. Cancer-related fatigue (CRF) is not relieved by rest, can decrease quality of life, and has no FDA-approved therapy. Thyrotropin-releasing hormone (TRH) has been proposed as a potential novel treatment for CRF, but its efficacy against CRF remains largely untested. Thus, we tested the TRH analog, taltirelin (TAL), in mouse models of CRF. To model fatigue, we used a mouse model of chemotherapy, a mouse model of radiation therapy, and mice bearing colon 26 carcinoma tumors. We used the treadmill fatigue test to assess fatigue-like behavior after treatment with TAL. Additionally, we used wild-type and TRH receptor knockout mice to determine which TRH receptor was necessary for the actions of TAL. Tumor-bearing mice displayed muscle wasting and all models caused fatigue-like behavior, with mice running a shorter distance in the treadmill fatigue test than controls. TAL reversed fatigue-like behavior in all three models and the mouse TRH1 receptor was necessary for the effects of TAL. These data suggest that TAL may be useful in alleviating fatigue in all cancer patients and provide further support for evaluating TAL as a potential therapy for CRF in humans.


Asunto(s)
Fatiga/tratamiento farmacológico , Nootrópicos/uso terapéutico , Hormona Liberadora de Tirotropina/análogos & derivados , Animales , Antimetabolitos Antineoplásicos/efectos adversos , Línea Celular Tumoral , Neoplasias del Colon/complicaciones , Neoplasias del Colon/patología , Modelos Animales de Enfermedad , Fatiga/etiología , Femenino , Fluorouracilo/efectos adversos , Rayos gamma/efectos adversos , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores de Hormona Liberadora de Tirotropina/genética , Hormona Liberadora de Tirotropina/uso terapéutico
15.
FASEB J ; 28(8): 3446-55, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24723693

RESUMEN

Thyrotropin (TSH) activation of the TSH receptor (TSHR), a 7-transmembrane-spanning receptor (7TMR), may have osteoprotective properties by direct effects on bone. TSHR activation by TSH phosphorylates protein kinases AKT1, p38α, and ERK1/2 in some cells. We found TSH-induced phosphorylation of these kinases in 2 cell lines engineered to express TSHRs, human embryonic kidney HEK-TSHR cells and human osteoblastic U2OS-TSHR cells. In U2OS-TSHR cells, TSH up-regulated pAKT1 (7.1±0.5-fold), p38α (2.9±0.4-fold), and pERK1/2 (3.1±0.2-fold), whereas small molecule TSHR agonist C2 had no or little effect on pAKT1 (1.8±0.08-fold), p38α (1.2±0.09-fold), and pERK1/2 (1.6±0.19-fold). Furthermore, TSH increased expression of osteoblast marker genes ALPL (8.2±4.6-fold), RANKL (21±5.9-fold), and osteopontin (OPN; 17±5.3-fold), whereas C2 had little effect (ALPL, 1.7±0.5-fold; RANKL, 1.3±0.6-fold; and OPN, 2.2±0.7-fold). ß-Arrestin-1 and -2 can mediate activatory signals by 7TMRs. TSH stimulated translocation of ß-arrestin-1 and -2 to TSHR, whereas C2 failed to translocate either ß-arrestin. Down-regulation of ß-arrestin-1 by siRNA inhibited TSH-stimulated phosphorylation of ERK1/2, p38α, and AKT1, whereas down-regulation of ß-arrestin-2 increased phosphorylation of AKT1 in both cell types and of ERK1/2 in HEK-TSHR cells. Knockdown of ß-arrestin-1 inhibited TSH-stimulated up-regulation of mRNAs for OPN by 87 ± 1.7% and RANKL by 73 ± 2.4%, and OPN secretion by 74 ± 10%. We conclude that TSH enhances osteoblast differentiation in U2OS cells that is, in part, caused by activatory signals mediated by ß-arrestin-1.


Asunto(s)
Arrestinas/fisiología , Osteoblastos/efectos de los fármacos , Tirotropina/fisiología , Neoplasias Óseas/patología , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica , Células HEK293 , Humanos , Proteínas de Neoplasias/fisiología , Osteoblastos/citología , Osteopontina/metabolismo , Osteosarcoma/patología , Fosforilación , Proteínas Quinasas/metabolismo , Procesamiento Proteico-Postraduccional , Interferencia de ARN , ARN Interferente Pequeño/farmacología , Receptores de Tirotropina/fisiología , Proteínas Recombinantes de Fusión , Transducción de Señal/fisiología , Tirotropina/farmacología , beta-Arrestina 1 , Arrestina beta 2 , beta-Arrestinas
18.
J Ultrasound Med ; 34(7): 1-41, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26112617

RESUMEN

The mechanical index (MI) has been used by the US Food and Drug Administration (FDA) since 1992 for regulatory decisions regarding the acoustic output of diagnostic ultrasound equipment. Its formula is based on predictions of acoustic cavitation under specific conditions. Since its implementation over 2 decades ago, new imaging modes have been developed that employ unique beam sequences exploiting higher-order acoustic phenomena, and, concurrently, studies of the bioeffects of ultrasound under a range of imaging scenarios have been conducted. In 2012, the American Institute of Ultrasound in Medicine Technical Standards Committee convened a working group of its Output Standards Subcommittee to examine and report on the potential risks and benefits of the use of conditionally increased acoustic pressures (CIP) under specific diagnostic imaging scenarios. The term "conditionally" is included to indicate that CIP would be considered on a per-patient basis for the duration required to obtain the necessary diagnostic information. This document is a result of that effort. In summary, a fundamental assumption in the MI calculation is the presence of a preexisting gas body. For tissues not known to contain preexisting gas bodies, based on theoretical predications and experimentally reported cavitation thresholds, we find this assumption to be invalid. We thus conclude that exceeding the recommended maximum MI level given in the FDA guidance could be warranted without concern for increased risk of cavitation in these tissues. However, there is limited literature assessing the potential clinical benefit of exceeding the MI guidelines in these tissues. The report proposes a 3-tiered approach for CIP that follows the model for employing elevated output in magnetic resonance imaging and concludes with summary recommendations to facilitate Institutional Review Board (IRB)-monitored clinical studies investigating CIP in specific tissues.


Asunto(s)
Acústica , Modelos Teóricos , Guías de Práctica Clínica como Asunto , Presión , Ultrasonografía/normas , Animales , Seguridad de Equipos , Humanos , Estados Unidos , United States Food and Drug Administration
19.
Am J Orthod Dentofacial Orthop ; 147(5 Suppl): S232-3, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25925653

RESUMEN

The American Board of Orthodontics was established in 1929 and is the oldest specialty board in dentistry. Its goal is to protect the public by ensuring competency through the certification of eligible orthodontists. Originally, applicants for certification submitted a thesis, 5 case reports, and a set of casts with appliances. Once granted, the certification never expired. Requirements have changed over the years. In 1950, 15 cases were required, and then 10 in 1987. The Board has continued to refine and improve the certification process. In 1998, certification became time limited, and a renewal process was initiated. The Board continues to improve the recertification process.


Asunto(s)
Certificación/métodos , Ortodoncia/normas , Consejos de Especialidades/normas , Certificación/historia , Competencia Clínica/normas , Educación Continua en Odontología , Educación de Posgrado en Odontología , Historia del Siglo XX , Humanos , Ortodoncia/educación , Ortodoncia/historia , Consejos de Especialidades/historia , Estados Unidos
20.
J Cell Physiol ; 229(6): 743-51, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24129818

RESUMEN

We showed previously that proliferating human islet-derived de-differentiated cells (DIDs) exhibit many characteristics of mesenchymal stem cells. Dispersed DIDs can be induced by serum deprivation to undergo mesenchymal-to-epithelial transition and aggregate into epithelial cell clusters (ECCs). Conversely, ECCs can be induced to disperse and undergo epithelial-to-mesenchymal transition (EMT) by re-addition of mammalian sera. In this study, we show that platelet-derived growth factor BB (PDGF-BB) mimics and mediates serum-induced ECCs' dispersal accompanied by accumulation of cytoplasmic ß-catenin and a decrease in the levels of insulin and glucagon mRNAs. Moreover, we show that PDGF-BB-induced dispersal of ECCs is a more general phenomenon that occurs also with bone marrow mesenchymal stem cells (BM-MSCs) and dermal fibroblasts (DFs). In DIDs, BM-MSCs, and DFs, PDGF decreased the levels of DKK1 mRNA, suggesting involvement of the Wnt signaling pathway. PDGF-BB stimulated a significant increase in S473 phosphorylation of Akt and the PI3K specific inhibitor (PIP828) partially inhibited PDGF-BB-induced ECC dispersal. Lastly, the PDGF-receptor (PDGF-R) antagonist JNJ-10198409 inhibited both PDGF-BB--and serum-induced ECC dispersal. Epidermal growth factor (EGF), which shares most of the PDGF signaling pathway, did not induce dispersal and only weakly stimulated Akt phosphorylation. Our data suggest that PDGF-BB mediates serum-induced DIDs dispersal, correlated with the activation of the PI3K-Akt pathway.


Asunto(s)
Movimiento Celular/fisiología , Células Epiteliales/fisiología , Células Secretoras de Insulina/fisiología , Páncreas/citología , Proteínas Proto-Oncogénicas c-sis/farmacología , Becaplermina , Movimiento Celular/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica/fisiología , Humanos , Células Secretoras de Insulina/citología , Fosforilación , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas Recombinantes/farmacología
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