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1.
Front Psychol ; 15: 1366617, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39015333

RESUMO

The nature and origins of addictions and of their adjunctive behaviors, as well as their chronicity, call for treatments that conceptualize and treat them as the long-term and complex processes that they are. Addictions are often comorbid with personality problems and with trauma histories. Patients suffering from these disorders often show poor engagement with treatment and high rates of relapse, possibly because available treatments have yet to address the patient suffering from addiction in a more integrated or holistic manner. In particular, comprehensive treatment models for addictive disorders - like treatments for personality disorders or trauma - are likely to require the integration of behavioral, cognitive, and emotion-focused interventions within a facilitative therapeutic relationship. However, most current treatment models, including ones which are highly effective in stabilization or behavioral change, lack one or more components of treatment that could sustain longer term recovery, wellness, and health for a higher percentage of patients. In this article, I propose approaching addictions and their treatment from the perspective of schema therapy, an integrative, developmental model with a strong track record of positive outcomes in addressing personality disorder symptoms and long-standing trauma histories, commonly comorbid with addictive disorders. In advancing this proposal, I begin by providing some background tying together addictions, attachment, and personality, suggesting they be treated simultaneously to achieve improved outcomes. Then, after briefly reviewing the leading approaches to the treatment of addictions, I introduce the idea that schema therapy is well-situated - both theoretically and practically - to address many of the shortcomings of existing treatment options. In particular, I note how addictive and co-occurring colluding behaviors are deeply intertwined with both early and continued frustration of core developmental needs. I illustrate how the addictive cycle is perpetuated through the process of schema reinforcement and through the operation of schema modes. I then demonstrate how these key terms (i.e., needs, schemas, and modes) inform the patient's assessment and case formulation, guiding treatment interventions from a strong therapeutic relationship that focuses on integrating recovery behavior change, healing dysfunctional schemas and modes, and preventing relapse.

2.
Am Surg ; : 31348241241739, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38578102

RESUMO

Tension pneumothorax (TPT) identified in the prehospital setting requires prehospital needle decompression (PHND). This study aimed to evaluate complications from PHND when it was performed without meeting clinical criteria. A retrospective review was performed of patients undergoing (PHND) from 2016 through 2022 at a level 1 trauma center. Patient data who received PHND were reviewed. Of 115 patients, 85 did not meet at least one clinical criterion for PHND. The majority of patients in this cohort 76 (89%) required a chest tube and 22 (25%) had an iatrogenic pneumothorax from PHND. 5 patients (6%) were admitted due to iatrogenic PHND. Two vascular injuries in this population were directly due to PHND and required emergency operative repair. This study shows the negative consequences of PHND when performed without clear indications. Several patients underwent unnecessary procedures with significant clinical consequences.

3.
Biol Open ; 11(8)2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-35876795

RESUMO

Formation of a properly sized and patterned embryo during gastrulation requires a well-coordinated interplay between cell proliferation, lineage specification and tissue morphogenesis. Following transient physical or pharmacological manipulations of embryo size, pre-gastrulation mouse embryos show remarkable plasticity to recover and resume normal development. However, it remains unclear how mechanisms driving lineage specification and morphogenesis respond to defects in cell proliferation during and after gastrulation. Null mutations in DNA replication or cell-cycle-related genes frequently lead to cell-cycle arrest and reduced cell proliferation, resulting in developmental arrest before the onset of gastrulation; such early lethality precludes studies aiming to determine the impact of cell proliferation on lineage specification and morphogenesis during gastrulation. From an unbiased ENU mutagenesis screen, we discovered a mouse mutant, tiny siren (tyrn), that carries a hypomorphic mutation producing an aspartate to tyrosine (D939Y) substitution in Pold1, the catalytic subunit of DNA polymerase δ. Impaired cell proliferation in the tyrn mutant leaves anterior-posterior patterning unperturbed during gastrulation but results in reduced embryo size and severe morphogenetic defects. Our analyses show that the successful execution of morphogenetic events during gastrulation requires that lineage specification and the ordered production of differentiated cell types occur in concordance with embryonic growth.


Assuntos
DNA Polimerase III , Gastrulação , Animais , DNA Polimerase III/genética , Embrião de Mamíferos , Gastrulação/genética , Camundongos , Morfogênese/genética , Mutação
4.
DNA Repair (Amst) ; 108: 103227, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34601382

RESUMO

RAD51 paralogs are key components of the homologous recombination (HR) machinery. Mouse mutants have been reported for four of the canonical RAD51 paralogs, and each of these mutants exhibits embryonic lethality, although at different gestational stages. However, the phenotype of mice deficient in the fifth RAD51 paralog, XRCC3, has not been reported. Here we report that Xrcc3 knockout mice exhibit midgestational lethality, with mild phenotypes beginning at about E8.25 but severe developmental abnormalities evident by E9.0-9.5. The most obvious phenotypes are small size and a failure of the embryo to turn to a fetal position. A knockin mutation at a key ATPase residue in the Walker A box results in embryonic lethality at a similar stage. Death of knockout mice can be delayed a few days for some embryos by homozygous or heterozygous Trp53 mutation, in keeping with an important role for XRCC3 in promoting genome integrity. Given that XRCC3 is a unique member of one of two RAD51 paralog complexes with RAD51C, these results demonstrate that both RAD51 paralog complexes are required for mouse development.


Assuntos
Proteínas de Ligação a DNA , Recombinação Homóloga , Rad51 Recombinase , Adenosina Trifosfatases/genética , Animais , Proteínas de Ligação a DNA/genética , Feminino , Camundongos , Gravidez , Rad51 Recombinase/genética
8.
Cell Rep ; 23(8): 2443-2454, 2018 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-29791854

RESUMO

Nup133 belongs to the Y-complex, a key component of the nuclear pore complex (NPC) scaffold. Studies on a null mutation in mice previously revealed that Nup133 is essential for embryonic development but not for mouse embryonic stem cell (mESC) proliferation. Using single-pore detection and average NE-fluorescence intensity, we find that Nup133 is dispensable for interphase and postmitotic NPC scaffold assembly in pluripotent mESCs. However, loss of Nup133 specifically perturbs the formation of the nuclear basket as manifested by the absence of Tpr in about half of the NPCs combined with altered dynamics of Nup153. We further demonstrate that its central domain mediates Nup133's role in assembling Tpr and Nup153 into a properly configured nuclear basket. Our findings thus revisit the role of the Y-complex in pore biogenesis and provide insights into the interplay between NPC scaffold architecture, nuclear basket assembly, and the generation of heterogeneity among NPCs.


Assuntos
Antígenos de Histocompatibilidade Menor/metabolismo , Células-Tronco Embrionárias Murinas/metabolismo , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Poro Nuclear/metabolismo , Animais , Feminino , Imageamento Tridimensional , Interfase , Masculino , Camundongos , Antígenos de Histocompatibilidade Menor/química , Complexo de Proteínas Formadoras de Poros Nucleares/química , Domínios Proteicos , Proteínas Proto-Oncogênicas/metabolismo
9.
Dev Cell ; 37(6): 488-90, 2016 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-27326926

RESUMO

The signaling pathways and cellular mechanisms that achieve alignment of dorsal and ventral midline structures remain a poorly understood aspect of vertebrate development. In this issue of Developmental Cell, Arraf et al. (2016) find a requisite role for bilaterally symmetrical BMP signaling in coordinating dorsal and ventral tissue morphogenesis.


Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Crescimento e Desenvolvimento , Animais , Embrião de Galinha , Galinhas , Modelos Biológicos , Morfogênese , Transdução de Sinais
10.
Cell Rep ; 9(2): 674-87, 2014 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-25373905

RESUMO

Sorting and degradation of receptors and associated signaling molecules maintain homeostasis of conserved signaling pathways during cell specification and tissue development. Yet, whether machineries that sort signaling proteins act preferentially on different receptors and ligands in different contexts remains mysterious. Here, we show that Vacuolar protein sorting 25, Vps25, a component of ESCRT-II (Endosomal Sorting Complex Required for Transport II), directs preferential endosome-mediated modulation of FGF signaling in limbs. By ENU-induced mutagenesis, we isolated a polydactylous mouse line carrying a hypomorphic mutation of Vps25 (Vps25(ENU)). Unlike Vps25-null embryos we generated, Vps25(ENU/ENU) mutants survive until late gestation. Their limbs display FGF signaling enhancement and consequent hyperactivation of the FGF-SHH feedback loop causing polydactyly, whereas WNT and BMP signaling remain unperturbed. Notably, Vps25(ENU/ENU) Mouse Embryonic Fibroblasts exhibit aberrant FGFR trafficking and degradation; however, SHH signaling is unperturbed. These studies establish that the ESCRT-II machinery selectively limits FGF signaling in vertebrate skeletal patterning.


Assuntos
Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Endossomos/metabolismo , Fatores de Crescimento de Fibroblastos/metabolismo , Proteínas Hedgehog/metabolismo , Polidactilia/genética , Transdução de Sinais , Proteínas de Transporte Vesicular/genética , Animais , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Extremidades/crescimento & desenvolvimento , Retroalimentação Fisiológica , Fibroblastos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Mutação , Polidactilia/metabolismo , Proteínas de Transporte Vesicular/metabolismo
11.
Curr Opin Genet Dev ; 23(4): 461-9, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23706163

RESUMO

Ventral folding morphogenesis (VFM), a vital morphogenetic process in amniotes, mediates gut endoderm internalization, linear heart tube formation, ventral body wall closure and encasement of the fetus in extraembryonic membranes. Aberrant VFM underlies a number of birth defects such as gastroschisis and ectopia cordis in human and misplacement of head and heart in mouse. Recent cell lineage-specific mouse mutant analyses identified the Bone Morphogenetic Protein (BMP) pathway and Anterior Visceral Endoderm (AVE) as key regulators of anterior VFM. Loss of BMP2 expression solely from embryonic visceral endoderm (EmVE) and the AVE blocks formation of foregut invagination, and simultaneously, aberrantly positions the heart anterior/dorsal to the head, suggesting a mechanistic link between foregut and head/heart morphogenesis.


Assuntos
Padronização Corporal/genética , Proteína Morfogenética Óssea 2/genética , Endoderma/crescimento & desenvolvimento , Morfogênese/genética , Animais , Proteína Morfogenética Óssea 2/metabolismo , Linhagem da Célula , Desenvolvimento Embrionário , Endoderma/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Cabeça/crescimento & desenvolvimento , Coração/crescimento & desenvolvimento , Humanos , Camundongos
12.
Cell Res ; 22(8): 1258-69, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22453236

RESUMO

Mutations of the CUL4B ubiquitin ligase gene are causally linked to syndromic X-linked mental retardation (XLMR). However, the pathogenic role of CUL4B mutations in neuronal and developmental defects is not understood. We have generated mice with targeted disruption of Cul4b, and observed embryonic lethality with pronounced growth inhibition and increased apoptosis in extra-embryonic tissues. Cul4b, but not its paralog Cul4a, is expressed at high levels in extra-embryonic tissues post implantation. Silencing of CUL4B expression in an extra-embryonic cell line resulted in the robust accumulation of the CUL4 substrate p21(Cip1/WAF) and G2/M cell cycle arrest, which could be partially rescued by silencing of p21(Cip1/WAF). Epiblast-specific deletion of Cul4b prevented embryonic lethality and gave rise to viable Cul4b null mice. Therefore, while dispensable in the embryo proper, Cul4b performs an essential developmental role in the extra-embryonic tissues. Our study offers a strategy to generate viable Cul4b-deficient mice to model the potential neuronal and behavioral deficiencies of human CUL4B XLMR patients.


Assuntos
Proteínas Culina/metabolismo , Embrião de Mamíferos/patologia , Desenvolvimento Embrionário , Regulação da Expressão Gênica no Desenvolvimento , Regulação Enzimológica da Expressão Gênica , Alelos , Animais , Apoptose , Cruzamentos Genéticos , Proteínas Culina/genética , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Perda do Embrião/enzimologia , Perda do Embrião/genética , Embrião de Mamíferos/metabolismo , Feminino , Pontos de Checagem da Fase G2 do Ciclo Celular , Inativação Gênica , Genótipo , Camadas Germinativas/citologia , Camadas Germinativas/metabolismo , Padrões de Herança , Pontos de Checagem da Fase M do Ciclo Celular , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação , Gravidez , Inativação do Cromossomo X
13.
Dev Cell ; 21(5): 907-19, 2011 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-22075149

RESUMO

In amniotes, ventral folding morphogenesis achieves gut internalization, linear heart tube formation, ventral body wall closure, and encasement of the fetus in extraembryonic membranes. Impairment of ventral morphogenesis results in human birth defects involving body wall, gut, and heart malformations and in mouse misplacement of head and heart. Absence of knowledge about genetic pathways and cell populations directing ventral folding in mammals has precluded systematic study of cellular mechanisms driving this vital morphogenetic process. We report tissue-specific mouse mutant analyses identifying the bone morphogenetic protein (BMP) pathway as a key regulator of ventral morphogenesis. BMP2 expressed in anterior visceral endoderm (AVE) signals to epiblast derivatives during gastrulation to orchestrate initial stages of ventral morphogenesis, including foregut development and positioning of head and heart. These findings identify unanticipated functions for the AVE in organizing the gastrulating embryo and indicate that visceral endoderm-expressed BMP2 coordinates morphogenetic cell behaviors in multiple epiblast lineages.


Assuntos
Proteína Morfogenética Óssea 2/metabolismo , Endoderma/metabolismo , Cabeça/embriologia , Coração/embriologia , Morfogênese , Animais , Proteína Morfogenética Óssea 2/deficiência , Proteína Morfogenética Óssea 2/genética , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Endoderma/citologia , Hibridização In Situ , Camundongos , Camundongos Knockout
14.
Dev Biol ; 341(1): 154-66, 2010 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-20178780

RESUMO

During vesicular transport between the endoplasmic reticulum and the Golgi, members of the TMED/p24 protein family form hetero-oligomeric complexes that facilitate protein-cargo recognition as well as vesicle budding. In addition, they regulate each other's level of expression. Despite analyses of TMED/p24 protein distribution in mammalian cells, yeast, and C. elegans, little is known about the role of this family in vertebrate embryogenesis. We report the presence of a single point mutation in Tmed2/p24beta(1) in a mutant mouse line, 99J, identified in an ENU mutagenesis screen for recessive developmental abnormalities. This mutation does not affect Tmed2/p24beta(1) mRNA levels but results in loss of TMED2/p24beta(1) protein. Prior to death at mid-gestation, 99J homozygous mutant embryos exhibit developmental delay, abnormal rostral-caudal elongation, randomized heart looping, and absence of the labyrinth layer of the placenta. We find that Tmed2/p24beta(1) is normally expressed in tissues showing morphological defects in 99J mutant embryos and that these affected tissues lack the TMED2/p24beta(1) oligomerization partners, TMED7/p24gamma(3) and TMED10/p24delta(1). Our data reveal a requirement for TMED2/p24beta(1) protein in the morphogenesis of the mouse embryo and placenta.


Assuntos
Embrião de Mamíferos/metabolismo , Morfogênese , Placenta/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Animais , Retículo Endoplasmático/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Membrana , Camundongos , Camundongos Endogâmicos C57BL , Mutação , Gravidez
15.
Dev Cell ; 14(6): 831-42, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18539113

RESUMO

Serving as the primary conduit for communication between the nucleus and the cytoplasm, nuclear pore complexes (NPCs) impact nearly every cellular process. The extent to which NPC composition varies and the functional significance of such variation in mammalian development has not been investigated. Here we report that a null allele of mouse nucleoporin Nup133, a structural subunit of the NPC, disrupts neural differentiation. We find that expression of Nup133 is cell type and developmental stage restricted, with prominent expression in dividing progenitors. Nup133-deficient epiblast and ES cells abnormally maintain features of pluripotency and differentiate inefficiently along the neural lineage. Neural progenitors achieve correct spatial patterning in mutant embryos; however, they are impaired in generating terminally differentiated neurons, as are Nup133 null ES cells. Our results reveal a role for structural nucleoporins in coordinating cell differentiation events in the developing embryo.


Assuntos
Diferenciação Celular , Neurônios/fisiologia , Poro Nuclear/química , Células-Tronco/fisiologia , Alelos , Animais , Biomarcadores/metabolismo , Diferenciação Celular/genética , Linhagem da Célula/genética , Células Cultivadas , Mapeamento Cromossômico , Cruzamentos Genéticos , Embrião de Mamíferos , Gástrula , Regulação da Expressão Gênica no Desenvolvimento , Hibridização In Situ , Camundongos , Camundongos Congênicos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Antígenos de Histocompatibilidade Menor , Mutação , Complexo de Proteínas Formadoras de Poros Nucleares/química , Complexo de Proteínas Formadoras de Poros Nucleares/genética , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Transcrição Gênica
16.
Lab Anim (NY) ; 35(10): 27-34, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17077832

RESUMO

The times they are a-changin' for GEM and the facilities that maintain them. Core facilities are expanding beyond their original conception as producers of transgenic mice to encompass a wide range of services, including research animal maintenance. In this paper, the authors describe the logistics and administration of the newly dubbed Mouse Genetics Core Facility at the Memorial Sloan-Kettering Cancer Center as a blueprint for other institutions seeking to expand and update their own transgenic cores for research in the twenty-first century.


Assuntos
Criação de Animais Domésticos/organização & administração , Pesquisa Biomédica/organização & administração , Ciência dos Animais de Laboratório/organização & administração , Ciência dos Animais de Laboratório/tendências , Camundongos Transgênicos , Criação de Animais Domésticos/métodos , Criação de Animais Domésticos/tendências , Animais , Pesquisa Biomédica/métodos , Pesquisa Biomédica/tendências , Camundongos , New York , Registros , Técnicas de Cultura de Tecidos
17.
Artigo em Inglês | MEDLINE | ID: mdl-16964911

RESUMO

We describe characterization of backscatter from tumor tissue targeted with a nanoparticle-based ultrasound contrast agent in vivo using analogs of thermodynamic quantities. We apply these waveform characteristics to detection of tumor neovasculature in tumors implanted in athymic nude mice, which were imaged using a research ultrasound scanner over a 2-hour period after injection of alpha upsilon beta3-targeted perfluorocarbon nanoparticles. Images were constructed from backscattered ultrasound using two different approaches: fundamental B-mode imaging and a signal receiver based on a thermodynamic analog (H(C)). The study shows that the thermodynamic analog is capable of detecting differences in backscattered signals that are not apparent with the B-mode approach.


Assuntos
Algoritmos , Neoplasias da Mama/diagnóstico por imagem , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Processamento de Sinais Assistido por Computador , Ultrassonografia/métodos , Animais , Linhagem Celular Tumoral , Meios de Contraste , Sistemas de Liberação de Medicamentos/métodos , Humanos , Camundongos , Camundongos Nus , Termodinâmica
18.
Arterioscler Thromb Vasc Biol ; 26(9): 2103-9, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16825592

RESUMO

OBJECTIVE: Angiogenic expansion of the vasa vasorum is a well-known feature of progressive atherosclerosis, suggesting that antiangiogenic therapies may stabilize or regress plaques. Alpha(v)beta3 integrin-targeted paramagnetic nanoparticles were prepared for noninvasive assessment of angiogenesis in early atherosclerosis, for site-specific delivery of antiangiogenic drug, and for quantitative follow-up of response. METHODS AND RESULTS: Expression of alpha(v)beta3 integrin by vasa vasorum was imaged at 1.5 T in cholesterol-fed rabbit aortas using integrin-targeted paramagnetic nanoparticles that incorporated fumagillin at 0 microg/kg or 30 microg/kg. Both formulations produced similar MRI signal enhancement (16.7%+/-1.1%) when integrated across all aortic slices from the renal arteries to the diaphragm. Seven days after this single treatment, integrin-targeted paramagnetic nanoparticles were readministered and showed decreased MRI enhancement among fumagillin-treated rabbits (2.9%+/-1.6%) but not in untreated rabbits (18.1%+/-2.1%). In a third group of rabbits, nontargeted fumagillin nanoparticles did not alter vascular alpha(v)beta3-integrin expression (12.4%+/-0.9%; P>0.05) versus the no-drug control. In a second study focused on microscopic changes, fewer microvessels in the fumagillin-treated rabbit aorta were counted compared with control rabbits. CONCLUSIONS: This study illustrates the potential of combined molecular imaging and drug delivery with targeted nanoparticles to noninvasively define atherosclerotic burden, to deliver effective targeted drug at a fraction of previous levels, and to quantify local response to treatment.


Assuntos
Inibidores da Angiogênese/administração & dosagem , Aterosclerose/metabolismo , Sistemas de Liberação de Medicamentos , Endotélio Vascular/metabolismo , Ácidos Graxos Insaturados/administração & dosagem , Integrina alfaVbeta3/metabolismo , Nanoestruturas , Neovascularização Patológica/prevenção & controle , Inibidores da Angiogênese/farmacologia , Animais , Aorta Abdominal/patologia , Aterosclerose/complicações , Aterosclerose/diagnóstico , Cicloexanos , Ácidos Graxos Insaturados/farmacologia , Hiperlipidemias/sangue , Imageamento por Ressonância Magnética , Neovascularização Patológica/etiologia , Coelhos , Sesquiterpenos
19.
J Acoust Soc Am ; 117(2): 964-72, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15759715

RESUMO

The ability to enhance specific molecular markers of pathology with ultrasound has been previously demonstrated by our group employing a nanoparticle contrast agent [Lanza et al., Invest. Radiol. 35, 227-234 (2000); Ultrasound Med. Biol. 23, 863-870 (1997)]. One of the advantages of this agent is very low echogenicity in the blood pool that allows increased contrast between the blood pool and the bound, site-targeted agent. We measured acoustic backscatter and attenuation coefficient as a function of the contrast agent concentration, ambient pressure, peak acoustic pressure, and as an effect of duty cycle and wave form shape. Measurements were performed while the nanoparticles were suspended in either whole porcine blood or plasma. The nanoparticles were only detectable when insonified within plasma devoid of red blood cells and were shown to exhibit backscatter levels more than 30 dB below the backscatter from whole blood. Attenuation of nanoparticles in whole porcine blood was not measurably different from that of whole blood alone over a range of concentrations up to eight times the maximum in vivo dose. The resulting data provide upper bounds on blood pool attenuation coefficient and backscatter and will be needed to more precisely define levels of molecular contrast enhancement that may be obtained in vivo.


Assuntos
Sangue , Meios de Contraste/farmacocinética , Nanoestruturas , Plasma , Ultrassonografia , Animais , Relação Dose-Resposta a Droga , Emulsões , Aumento da Imagem , Microbolhas , Espalhamento de Radiação , Processamento de Sinais Assistido por Computador , Suínos , Transdutores
20.
Magn Reson Med ; 53(3): 621-7, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15723405

RESUMO

Neovascularization is a critical component in the progression of malignant melanoma. The objective of this study was to determine whether alpha(nu)beta(3)-targeted paramagnetic nanoparticles can detect and characterize sparse alpha(nu)beta integrin expression on neovasculature induced by nascent melanoma xenografts ( approximately 30 mm(3)) at 1.5T. Athymic nude mice bearing human melanoma tumors were intravenously injected with alpha(v)beta(3)-integrin-targeted paramagnetic nanoparticles, nontargeted paramagnetic nanoparticles, or alpha(v)beta(3)-targeted-nonparamagnetic nanoparticles 2 hr before they were injected with alpha(v)beta(3)-integrin-targeted paramagnetic nanoparticles (i.e., in vivo competitive blockade) and imaged with MRI. Contrast enhancement of neovascularity in animals that received alpha(nu)beta(3)-targeted paramagnetic nanoparticles increased 173% by 120 min. Signal contrast with nontargeted paramagnetic nanoparticles was approximately 50% less than that in the targeted group (P < 0.05). Molecular MRI results were corroborated by histology. In a competitive cell adhesion assay, incubation of alpha(nu)beta(3)-expressing cells with targeted nanoparticles significantly inhibited binding to a vitronectin-coated surface, confirming the bioactivity of the targeted nanoparticles. The present study lowers the limit previously reported for detecting sparse biomarkers with molecular MRI in vivo. This technique may be employed to noninvasively detect very small regions of angiogenesis associated with nascent melanoma tumors, and to phenotype and stage early melanoma in a clinical setting.


Assuntos
Integrina alfaVbeta3/metabolismo , Angiografia por Ressonância Magnética , Melanoma/metabolismo , Melanoma/patologia , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Análise de Variância , Animais , Processamento de Imagem Assistida por Computador , Imuno-Histoquímica , Integrina alfaVbeta3/biossíntese , Camundongos , Nanotecnologia , Transplante de Neoplasias , Neoplasias Experimentais/irrigação sanguínea , Tamanho da Partícula
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