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1.
J Appl Clin Med Phys ; 25(2): e14255, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38179858

RESUMO

PURPOSE: Screening mammography and digital breast tomosynthesis consist of high-resolution x-ray images to identify findings that are potentially indicative of breast cancer, enabling early detection and reduction of breast cancer mortality. Imaging artifacts can occasionally occur, sometimes due to patient-related medical devices. Because of continuous evolution of new technologies, there is potential for novel artifacts to be encountered. In this technical note, we report an unusual artifact in the screening mammogram of a patient with an Abbott HeartMate 3 left ventricular assist device (LVAD). METHODS: A 72-year-old patient with a HeartMate 3 LVAD presented to our breast imaging facility for a standard screening exam with digital breast tomosynthesis (Selenia Dimensions, Hologic Inc., Bedford, MA) and synthetic 2D images (C-view, Hologic Inc., Bedford, MA). RESULTS: Linear artifacts oriented in the anteroposterior dimension demonstrating a spatial periodicity of ∼1.4 mm were seen on all left breast images, whereas concurrent right breast images did not demonstrate any artifacts. Repeat attempts using two identical digital breast tomosynthesis units demonstrated the same artifacts. No other exam at our imaging center that day demonstrated any such artifacts. Mammogram exams performed on this patient prior to her LVAD placement did not exhibit any similar artifacts. CONCLUSION: Findings support the patient's LVAD as the underlying source of linear artifacts observed on left breast images, particularly given the proximity of the LVAD to the left breast. With the number of patients receiving LVAD placement on the rise, as well as increasing median survival rates status post LVAD implantation, recognition of this LVAD related artifact on mammography may be important.


Assuntos
Neoplasias da Mama , Coração Auxiliar , Humanos , Feminino , Idoso , Mamografia/métodos , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/cirurgia , Artefatos , Detecção Precoce de Câncer/métodos
2.
Pediatr Radiol ; 51(8): 1378-1385, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33688988

RESUMO

BACKGROUND: Abdominopelvic magnetic resonance imaging (MRI) is increasingly being used to evaluate children with abdominal pain suspected of having acute appendicitis. At our institution, these examinations are preliminarily interpreted by radiology residents, especially when performed after hours. OBJECTIVE: To determine the accuracy of preliminary reports rendered by radiology residents in this setting. MATERIALS AND METHODS: Three hundred seventy-seven pediatric abdominopelvic MRI examinations were included. The preliminary (resident) and final (attending) radiology reports were coded as diagnosing acute appendicitis or no acute appendicitis. The concordance between resident and attending radiologist interpretations was calculated. Additionally, both resident and attending reports were compared to available surgical pathology or clinical follow-up data. RESULTS: Overall concordance rate for the diagnosis of acute appendicitis was 97.1%. Concordance for verified cases of acute appendicitis was 93.4%. Concordance rates did not differ by residents' postgraduate year levels. When compared against surgical pathology or clinical follow-up data, residents demonstrated 91.2% sensitivity and 97.6% specificity. There was no statistically significant difference in the sensitivity or specificity of resident or attending radiologist interpretations. CONCLUSION: Radiology residents demonstrate high concordance with attending pediatric radiologists in their interpretations of pediatric abdominopelvic MRI for acute appendicitis. The diagnostic performances of residents and attendings were comparable.


Assuntos
Internato e Residência , Radiologia , Dor Abdominal/diagnóstico por imagem , Criança , Humanos , Imageamento por Ressonância Magnética , Radiografia , Radiologia/educação
3.
Emerg Radiol ; 27(1): 9-16, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31463805

RESUMO

PURPOSE: To determine the diagnostic accuracy of an abbreviated magnetic resonance imaging (MRI) protocol of the foot for the diagnosis of osteomyelitis in patients with acute foot infection. METHODS: This retrospective study evaluated adult patients (age 18 and over) visiting an academic medical center from 1 January 2013 to 31 December 2015 who were imaged with MRI for suspected acute pedal osteomyelitis. Examinations were performed utilizing the departmental standard protocol. All examinations were retrospectively interpreted by five radiologists under two protocols: a reference standard protocol consisting of all non-contrast sequences obtained at initial acquisition and an abbreviated protocol consisting of only coronal T1-weighted and sagittal T2-weighted fast multiplanar inversion-recovery (FMPIR) sequences. Interpretation of the two imaging subsets was separated in time by at least 6 weeks for each reader. Each examination was assigned a score to represent one of four diagnostic categories: normal; soft tissue infection without bone changes or bone changes specific to a non-infectious etiology; nonspecific bone marrow changes; or bone changes specific for osteomyelitis. Diagnostic accuracy of both protocols was determined based on clinical diagnosis and treatment of osteomyelitis, and histopathology when available. RESULTS: One hundred and two MRI examinations met inclusion criteria; participants ranged in age from 26 to 91 years, with a mean age of 59 years. Seventy examinations were performed for male participants (69%) and 32 for female participants (31%). Thirty-five had a confirmed diagnosis of osteomyelitis, while the remainder (n = 67) did not. An average of 6 non-contrast sequences was performed during each examination. The most common protocol (53/102 examinations) was comprised of the following 6 sequences: axial T1-weighted, axial fat-saturated proton density, sagittal T1-weighted, sagittal T2-weighted FMPIR, coronal T1-weighted, and coronal fat-saturated proton density. After patient positioning, the abbreviated protocol sequences (sagittal T2-weighted FMPIR and coronal T1-weighted) were performed in an average total of 8 min. The reference standard protocol required an average of 22 min to complete 6 sequences. Averaged across all readers, the AUC for the reference standard full protocol and the abbreviated protocols were 0.843 and 0.873, respectively. The difference in AUC between protocols was not statistically significant (p = 0.1297), with the abbreviated protocol showing a non-significantly greater AUC. CONCLUSIONS: An abbreviated MRI protocol, including only coronal T1-weighted and sagittal T2-weighted FMPIR images, is non-inferior to standard MRI protocol for the diagnosis of acute pedal osteomyelitis. It should be considered as a diagnostic alternative for reducing imaging time and improving patient access to MRI.


Assuntos
Pé/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Osteomielite/diagnóstico por imagem , Doença Aguda , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
4.
J Xray Sci Technol ; 28(3): 405-426, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32333575

RESUMO

BACKGROUND: High-resolution, low-noise detectors with minimal dead-space at chest-wall could improve posterior coverage and microcalcification visibility in the dedicated cone-beam breast CT (CBBCT). However, the smaller field-of-view necessitates laterally-shifted detector geometry to enable optimizing the air-gap for x-ray scatter rejection. OBJECTIVE: To evaluate laterally-shifted detector geometry for CBBCT with clinical projection datasets that provide for anatomical structures and lesions. METHODS: CBBCT projection datasets (n = 17 breasts) acquired with a 40×30 cm detector (1024×768-pixels, 0.388-mm pixels) were truncated along the fan-angle to emulate 20.3×30 cm, 22.2×30 cm and 24.1×30 cm detector formats and correspond to 20, 120, 220 pixels overlap in conjugate views, respectively. Feldkamp-Davis-Kress (FDK) algorithm with 3 different weighting schemes were used for reconstruction. Visual analysis for artifacts and quantitative analysis of root-mean-squared-error (RMSE), absolute difference between truncated and 40×30 cm reconstructions (Diff), and its power spectrum (PSDiff) were performed. RESULTS: Artifacts were observed for 20.3×30 cm, but not for other formats. The 24.1×30 cm provided the best quantitative results with RMSE and Diff (both in units of µ, cm-1) of 4.39×10-3±1.98×10-3 and 4.95×10-4±1.34×10-4, respectively. The PSDiff (>0.3 cycles/mm) was in the order of 10-14µ2mm3 and was spatial-frequency independent. CONCLUSIONS: Laterally-shifted detector CBBCT with at least 220 pixels overlap in conjugate views (24.1×30 cm detector format) provides quantitatively accurate and artifact-free image reconstruction.


Assuntos
Mama/diagnóstico por imagem , Tomografia Computadorizada de Feixe Cônico/métodos , Mamografia/métodos , Algoritmos , Neoplasias da Mama/diagnóstico por imagem , Estudos de Viabilidade , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Estudos Retrospectivos
5.
Radiology ; 291(1): 170-177, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30747595

RESUMO

Background Advances in abdominal MRI have enabled rapid, free-breathing imaging without the need for intravenous or oral contrast material. The use of MRI as the primary imaging modality for suspected appendicitis has not been previously studied. Purpose To determine the diagnostic performance of MRI as the initial imaging modality in children suspected of having acute appendicitis. Materials and Methods The study included consecutive patients 18 years of age and younger presenting with acute abdominal pain at a tertiary care institution from January 2013 through June 2016 who subsequently underwent an unenhanced MRI examination as the primary diagnostic imaging modality. Electronic medical records and radiology reports were retrospectively evaluated for the feasibility and diagnostic performance of MRI, with surgical pathology and follow-up electronic records as reference standards. Statistical analyses were performed by using simple binomial proportions to quantify sensitivity, specificity, and accuracy, and exact 95% confidence intervals (CIs) were obtained. Results After exclusions, 402 patients (median age: 13 years; interquartile range [IQR], 9-15 years; 235 female patients; 167 male patients) were included. Sedation for MRI was required in 13 of 402 patients (3.2%; 95% CI: 1.7%, 5.5%). The appendix was visualized in 349 of 402 patients (86.8%; 95% CI: 83.1%, 90%); for the remaining patients, a diagnosis was provided on the basis of secondary signs of appendicitis. The sensitivity, specificity, and accuracy of MRI as the primary diagnostic imaging modality for the evaluation of acute appendicitis were 97.9% (95 of 97; 95% CI: 92.8%, 99.8%), 99% (302 of 305; 95% CI: 97.2%, 99.8%), and 98.8% (397 of 402; 97.1%, 99.6%), respectively. Among patients with negative findings for appendicitis at MRI, an alternate diagnosis was provided in 113 of 304 patients (37.2%; 95% CI: 31.7%, 42.9%). Conclusion When performed as the initial imaging modality in children suspected of having acute appendicitis, MRI examinations had high diagnostic performance for the diagnosis of acute appendicitis and in providing alternative diagnoses. © RSNA, 2019 See also the editorial by Dillman and Trout in this issue.


Assuntos
Apendicite/diagnóstico , Imageamento por Ressonância Magnética/normas , Dor Abdominal/etiologia , Doença Aguda , Adolescente , Criança , Pré-Escolar , Estudos de Viabilidade , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Estudos Retrospectivos , Sensibilidade e Especificidade
6.
J Magn Reson Imaging ; 49(1): 239-252, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30142230

RESUMO

BACKGROUND: T1 mapping is often used in some clinical protocols. Existing techniques are limited in slice coverage, and/or spatial-temporal resolution, or require long acquisitions. Here we present a multi-slice inversion-recovery (IR) radial steady-state free precession (radSSFP) pulse sequence combined with a principal component (PC) based reconstruction that overcomes these limitations. PURPOSE: To develop a fast technique for multi-slice high-resolution T1 mapping. STUDY TYPE: Technical efficacy study done prospectively. PHANTOM/SUBJECTS: IR-radSSFP was tested in phantoms, five healthy volunteers, and four patients with abdominal lesions. FIELD STRENGTH/SEQUENCE: IR-radSSFP was implemented at 3T. ASSESSMENT: Computer simulations were performed to optimize the flip angle for T1 estimation; testing was done in phantoms using as reference an IR spin-echo pulse sequence. T1 mapping with IR-radSSFP was also assessed in vivo (brain and abdomen) and T1 values were compared with literature. T1 maps were also compared with a radial IR-FLASH technique. STATISTICAL TESTS: A two-tailed t-test was used to compare T1 values in phantoms. A repeatability study was carried out in vivo using Bland-Altman analysis. RESULTS: Simulations and phantom experiments showed that a flip angle of 20˚ was optimal for T1 mapping. When comparing single to multi-slice experiments in phantoms there were no significant differences between the means T1 values (P = 0.0475). In vivo results show that T1 maps with spatial resolution as high as 0.69 mm × 0.69 mm × 2.00 mm (brain) and 0.83 mm × 0.83 mm × 3.00 mm (abdomen) can be generated for 84 brain slices in 3 min and 10 abdominal slices in a breath-hold; T1 values were comparable to those reported in literature. The coefficients of variation from the repeatability study were 1.7% for brain and 2.5-2.7% in the abdomen. DATA CONCLUSION: A multi-slice IR-radSSFP technique combined with a PC-based reconstruction was demonstrated for higher resolution T1 mapping. This technique is fast, motion-insensitive and yields repeatable T1 values comparable to those in literature. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;49:239-252.


Assuntos
Abdome/diagnóstico por imagem , Neoplasias Abdominais/diagnóstico por imagem , Imageamento por Ressonância Magnética , Algoritmos , Encéfalo/diagnóstico por imagem , Suspensão da Respiração , Simulação por Computador , Voluntários Saudáveis , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Processamento de Imagem Assistida por Computador , Modelos Estatísticos , Imagens de Fantasmas , Análise de Componente Principal , Estudos Prospectivos , Reprodutibilidade dos Testes
7.
Mol Cell Biochem ; 456(1-2): 179-190, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30767098

RESUMO

Hyperglycaemia during pregnancy is the main reason for developing diabetes mediated vascular complications. Advanced glycation end products (AGEs) are formed due to non-enzymatic glycation of proteins, lipids and nucleic acids during hyperglycaemia. It has the potential to damage vasculature by modifying the substrate or by means of AGEs and receptor of AGE (RAGE) interaction. It has been linked with the pathogenesis of various vascular diseases including coronary heart disease, atherosclerosis, restenosis etc. This study was carried out to investigate the role of AGEs-EGR-1 pathway in gestational diabetes mellitus (GDM) vascular inflammation. Human umbilical vein endothelial cells (HuVECs) isolated from normal glucose tolerant mothers were subjected to various treatments including high glucose, silencing of early growth response (EGR)-1, blockade of protein kinase C (PKC) ß, blocking extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), and treatment with AGEs and assayed for EGR-1, tissue factor (TF) and soluble intercellular adhesion molecule (sICAM)-1. Similarly, umbilical vein endothelial cells isolated from normal and GDM mothers were assayed for EGR-1, TF, and sICAM-1. There was a significant increase in EGR-1 and TF levels in HuVECs isolated form GDM mother's umbilical cord and normal HuVECs treated with high glucose condition. This was accompanied by elevated levels of sICAM-1 in high glucose treated cells. Our results revealed AGE-mediated activation of EGR-1 and its downstream genes via PKC ßII and ERK1/2 signaling pathway. The present study demonstrated a novel mechanism of AGEs/ PKC ßII/ ERK1/2/EGR-1 pathway in inducing vascular inflammation in GDM.


Assuntos
Diabetes Gestacional/metabolismo , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Células Endoteliais da Veia Umbilical Humana/metabolismo , Sistema de Sinalização das MAP Quinases , Antígenos de Neoplasias/metabolismo , Diabetes Gestacional/patologia , Feminino , Células Endoteliais da Veia Umbilical Humana/patologia , Humanos , Molécula 1 de Adesão Intercelular/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Gravidez , Proteína Quinase C beta/metabolismo , Tromboplastina/metabolismo
9.
Gynecol Endocrinol ; 35(9): 811-814, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30964350

RESUMO

Proper vascular function is important for well-being of mother and growing fetus. VEGFTOTAL, and VEGF165b levels and its vascular endothelial complications in gestational diabetes mellitus (GDM) together with the association of inflammation and advanced glycation end products (AGEs) are less studied. VEGF165b/VEGFTOTAL (VEGF RATIO) in GDM pregnant women was investigated in this study. Plasma VEGFTOTAL was lower in GDM (17.68 ± 1.30 pg/mL) compared to non-GDM (25.69 ± 1.40 pg/mL). VEGF165b, ICAM-1, and AGEs were higher in GDM (9.9 ± 1.4 pg/mL, 201.04 ± 7.85 µg/mL, and 10.40 ± 0.98 µg/mL, respectively) and lower in non-GDM (6.47 ± 0.70 pg/mL, 174.1 ± 7.11 µg/mL, and 4.71 ± 0.39 µg/mL, respectively). Compared to non GDM (0.25 ± 0.02), VEGF RATIO was higher in GDM (0.45 ± 0.04) and correlated with -ICAM-1 (r = 0.375, p < .001) and AGEs (r = 0.199, p < .05). Tertile stratification of VEGF RATIO implied that frequency of GDM increases with increasing tertiles of VEGF RATIO (p for trend <.001). Association of VEGF RATIO with GDM was significant even after adjusting for AGEs (OR = 1.279, CI = 1.118-1.462, p < .0010) but it lost its significance when adjusted for ICAM-1 (OR = 1.006, CI = 0.995-1.017, p = .308). VEGF RATIO plays an important role in GDM in association with vascular inflammation.


Assuntos
Diabetes Gestacional/sangue , Fator A de Crescimento do Endotélio Vascular/sangue , Adulto , Glicemia/análise , Glicemia/metabolismo , Estudos de Casos e Controles , Feminino , Produtos Finais de Glicação Avançada/sangue , Humanos , Molécula 1 de Adesão Intercelular/sangue , Fragmentos de Peptídeos/sangue , Gravidez , Complicações Cardiovasculares na Gravidez/sangue , Isoformas de Proteínas/sangue , Isoformas de Proteínas/química , Fator A de Crescimento do Endotélio Vascular/química , Malformações Vasculares/sangue , Malformações Vasculares/complicações , Adulto Jovem
10.
Int J Mol Sci ; 20(13)2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-31284541

RESUMO

The process of arteriogenesis is severely compromised in patients with diabetes mellitus (DM). Earlier studies have reported the importance of Egr-1 in promoting collateral outward remodeling. However, the role of Egr-1 in the presence of DM in outward vessel remodeling was not studied. We hypothesized that Egr-1 expression may be compromised in DM which may lead to impaired collateral vessel growth. Here, we investigated the relevance of the transcription factor Egr-1 for the process of collateral artery growth in diabetic mice. Induction of arteriogenesis by femoral artery ligation resulted in an increased expression of Egr-1 on mRNA and protein level but was severely compromised in streptozotocin-induced diabetic mice. Diabetes mellitus mice showed a significantly reduced expression of Egr-1 endothelial downstream genes Intercellular Adhesion Molecule-1 (ICAM-1) and urokinase Plasminogen Activator (uPA), relevant for extravasation of leukocytes which promote arteriogenesis. Fluorescent-activated cell sorting analyses confirmed reduced leukocyte recruitment. Diabetes mellitus mice showed a reduced expression of the proliferation marker Ki-67 in growing collaterals whose luminal diameters were also reduced. The Splicing Factor-1 (SF-1), which is critical for smooth muscle cell proliferation and phenotype switch, was found to be elevated in collaterals of DM mice. Treatment of DM mice with insulin normalized the expression of Egr-1 and its downstream targets and restored leukocyte recruitment. SF-1 expression and the diameter of growing collaterals were normalized by insulin treatment as well. In summary, our results showed that Egr-1 signaling was impaired in DM mice; however, it can be rescued by insulin treatment.


Assuntos
Diabetes Mellitus Experimental/patologia , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Artéria Femoral/crescimento & desenvolvimento , Insulinas/farmacologia , Morfogênese/efeitos dos fármacos , Transdução de Sinais , Regulação para Cima/efeitos dos fármacos , Animais , Antígenos CD/metabolismo , Circulação Colateral/efeitos dos fármacos , Diabetes Mellitus Experimental/genética , Artéria Femoral/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Leucócitos/efeitos dos fármacos , Leucócitos/metabolismo , Leucócitos/patologia , Masculino , Camundongos Endogâmicos C57BL , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais/efeitos dos fármacos
11.
J Xray Sci Technol ; 27(3): 431-442, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30909268

RESUMO

OBJECTIVE: To investigate the image quality and x-ray dose associated with a transmission computed tomography (CT) component implemented within the same platform of an experimental benchtop x-ray fluorescence CT (XFCT) system for multimodal preclinical imaging applications. METHODS: Cone-beam CT scans were performed using an experimental benchtop CT + XFCT system and a cylindrically-shaped 3D-printed polymethyl methacrylate phantom (3 cm in diameter, 7 cm in height) loaded with various concentrations (0.05-1 wt. %) of gold nanoparticles (GNPs). Two commercial CT quality assurance phantoms containing 3D line-pair (LP) targets and contrast targets were also scanned. The x-ray beams of 40 and 62 kVp, both filtered by 0.08 mm Cu and 0.4 mm Al, were used with 17 ms of exposure time per projection at three current settings (2.5, 5, and 10 mA). The ordered-subset simultaneous algebraic reconstruction and total variation-minimization methods were used to reconstruct images. Sparse projection and short scan were considered to reduce the x-ray dose. The contrast-to-noise ratio (CNR) and modulation transfer function (MTF) were calculated. RESULTS: The lowest detectable concentration of GNPs (CNR > 5) and the highest spatial resolution (per MTF50%) were 0.10 wt. % and 9.5 LP/CM, respectively, based on the images reconstructed from 360 projections of the 40 kVp beam (or x-ray dose of 3.44 cGy). The background noise for the image resulting in the lowest GNP detection limit was 25 Hounsfield units. CONCLUSION: The transmission CT component within the current experimental benchtop CT + XFCT system produced images deemed acceptable for multimodal (CT + XFCT) imaging purposes, with less than 4 cGy of x-ray dose.


Assuntos
Tomografia Computadorizada de Feixe Cônico/instrumentação , Imageamento Tridimensional , Limite de Detecção , Imagem Multimodal , Imagens de Fantasmas , Doses de Radiação , Razão Sinal-Ruído
13.
Microvasc Res ; 117: 37-43, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29307595

RESUMO

Early growth response-1 (Egr-1) protein upregulation is reported in diabetes and vascular disorders. This study aims at deciphering its role in hyperglycemia induced changes of retinal endothelium. Human retinal endothelial cells (hRECs) were exposed to hyperglycemia (25mM) and normoglycemia (5.5mM). Gene silencing was done using siRNA against Egr-1. Transcript and protein level analysis of Egr-1 and gene targets were done using qPCR and immunoblotting respectively in hRECs, diabetic and nondiabetic human retina and immunofluorescence for localization in retinal sections. Hyperglycemia induced Egr-1 and vascular endothelial growth factor-A (VEGF-A) but not pigment epithelium derived factor (PEDF) in hRECs. Expression of Egr-1 repressor NGFI-A binding protein-2 (NAB-2) was unaltered. Egr-1 downstream gene targets, tissue factor (TF) and intercellular adhesion molecule-1 (ICAM-1) expression were increased in hRECs which was reduced by Egr-1 silencing in hyperglycemia. Diabetic retina, showed an increase in Egr-1, VEGF-A and gene target TF, ICAM-1 but not NAB-2 and PEDF similar to the changes seen in hyperglycemic hRECs. Hyperglycemic induction of Egr-1 and absence of NAB-2 repression in retinal endothelium, up-regulates downstream genes involved in pro-thrombotic and pro-inflammatory pathways linking Egr-1 in diabetes mediated vascular aberration of retina.


Assuntos
Retinopatia Diabética/metabolismo , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Células Endoteliais/metabolismo , Glucose/metabolismo , Hiperglicemia/metabolismo , Vasos Retinianos/metabolismo , Células Cultivadas , Retinopatia Diabética/genética , Retinopatia Diabética/fisiopatologia , Proteína 1 de Resposta de Crescimento Precoce/genética , Células Endoteliais/efeitos dos fármacos , Proteínas do Olho/metabolismo , Glucose/toxicidade , Humanos , Hiperglicemia/genética , Hiperglicemia/fisiopatologia , Molécula 1 de Adesão Intercelular/genética , Molécula 1 de Adesão Intercelular/metabolismo , Fatores de Crescimento Neural/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Vasos Retinianos/efeitos dos fármacos , Vasos Retinianos/fisiopatologia , Serpinas/metabolismo , Transdução de Sinais , Tromboplastina/genética , Tromboplastina/metabolismo , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular/metabolismo
14.
Biochim Biophys Acta ; 1862(12): 2221-2231, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27543804

RESUMO

Acetylation of proteins as a post-translational modification is gaining rapid acceptance as a cellular control mechanism on par with other protein modification mechanisms such as phosphorylation and ubiquitination. Through genetic manipulations and evolving proteomic technologies, identification and consequences of transcription factor acetylation is beginning to emerge. In this review, we summarize the field and discuss newly unfolding mechanisms and consequences of transcription factor acetylation in normal and stressed hearts. This article is part of a Special Issue entitled: The role of post-translational protein modifications on heart and vascular metabolism edited by Jason R.B. Dyck & Jan F.C. Glatz.


Assuntos
Doenças Cardiovasculares/metabolismo , Miocárdio/metabolismo , Processamento de Proteína Pós-Traducional , Fatores de Transcrição/metabolismo , Acetilação , Animais , Doenças Cardiovasculares/patologia , Humanos , Miocárdio/patologia
15.
Anal Biochem ; 528: 19-25, 2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28445706

RESUMO

Increased consumption of raw and par-boiled rice results in the formation of methylglyoxal (MG) at higher concentration and leads to complications in diabetic patients. Highly sensitive electrochemical biosensor was developed using glutathione (GSH) as a co-factor with vanadium pentoxide (V2O5) as a nano-interface for MG detection in rice samples. The Pt/V2O5/GSH/Chitosan bioelectrode displayed two well-defined redox peaks in its cyclic voltammograms for MG reduction. This occurred as two electron transfer process where MG gained two electrons from oxidized glutathione disulfide and formed hemithioacetal. The current density response of the fabricated bioelectrode was linear towards MG in the concentration range of 0.1-100 µM with the correlation coefficient of 0.99, sensitivity of 1130.86 µA cm-2 µM-1, limit of detection of 2 nM and response time of less than 18 s. The developed bioelectrode was used for the detection of MG in raw and par-boiled rice samples.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas/métodos , Análise de Alimentos/métodos , Oryza/química , Aldeído Pirúvico/análise , Quitosana/química , Glutationa/química , Limite de Detecção , Nanopartículas/química , Oxirredução , Aldeído Pirúvico/metabolismo , Propriedades de Superfície , Compostos de Vanádio/química
17.
Emerg Radiol ; 24(5): 497-503, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28374140

RESUMO

BACKGROUND AND PURPOSE: The standard head CT protocol makes detection of a temporal bone fracture difficult. The purposes of our study are to revisit the finding of air in various locations around the temporal bone as an indirect sign of fracture and determine if findings could predict fracture pattern. MATERIALS AND METHODS: We searched the radiology reports for the keyword "temporal bone fracture." We recorded the presence of air in multiple locations around the temporal bone and pneumocephalus, opacification of the mastoid air cells or the middle ear cavity, and dominant fracture pattern. Statistical analyses were performed using statistical software. RESULTS: A total of 135 patients (mean age 40 ± 20.1 years, 101 male, 34 female, range 1-91) had 152 fractures. At least one indirect finding was present in 143 (94.1%) fractures. Air was present adjacent to the styloid process in 94 (61.8%), in the temporomandibular joint in 80 (52.6%), adjacent to the mastoid process in 57 (37.5%), and along the adjacent dural venous sinus in 33 (21.7%) fractures. Mastoid opacification was present in 139 (91.4%) fractures. Opacification of the middle ear cavity was present in 121 (79.6%) fractures. A complex fracture significantly and positively correlated with pneumocephalus. CONCLUSION: In the setting of trauma, air around the temporal bone and opacification of the mastoid air cells or middle ear cavity should prompt consideration of a temporal bone fracture even if the fracture line is not visible. The presence of pneumocephalus predicts a higher chance of complex fracture pattern.


Assuntos
Pneumocefalia/diagnóstico por imagem , Fraturas Cranianas/diagnóstico por imagem , Osso Temporal/diagnóstico por imagem , Osso Temporal/lesões , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade
18.
Stroke ; 46(12): 3507-13, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26493676

RESUMO

BACKGROUND AND PURPOSE: The goal of this study is to combine temporary endovascular bypass (TEB) with a novel shear-activated nanotherapeutic (SA-NT) that releases recombinant tissue-type plasminogen activator (r-tPA) when exposed to high levels of hemodynamic stress and to determine if this approach can be used to concentrate r-tPA at occlusion sites based on high shear stresses created by stent placement. METHODS: A rabbit model of carotid vessel occlusion was used to test the hypothesis that SA-NT treatment coupled with TEB provides high recanalization rates while reducing vascular injury. We evaluated angiographic recanalization with TEB alone, intra-arterial delivery of soluble r-tPA alone, or TEB combined with 2 doses of intra-arterial infusion of either the SA-NT or soluble r-tPA. Vascular injury was compared against stent-retriever thrombectomy. RESULTS: Shear-targeted delivery of r-tPA using the SA-NT resulted in the highest rate of complete recanalization when compared with controls (P=0.0011). SA-NT (20 mg) had a higher likelihood of obtaining complete recanalization as compared with TEB alone (odds ratio 65.019, 95% confidence interval 1.77, >1000; P=0.0231), intra-arterial r-tPA alone (odds ratio 65.019, 95% confidence interval 1.77, >1000; P=0.0231), or TEB with soluble r-tPA (2 mg; odds ratio 18.78, 95% confidence interval 1.28, 275.05; P=0.0322). Histological analysis showed circumferential loss of endothelium restricted to the area where the TEB was deployed; however, there was significantly less vascular injury using a TEB as compared with stent-retriever procedure (odds ratio 12.97, 95% confidence interval 8.01, 21.02; P<0.0001). CONCLUSIONS: A novel intra-arterial, nanoparticle-based thrombolytic therapy combined with TEB achieves high rates of complete recanalization. Moreover, this approach reduces vascular trauma as compared with stent-retriever thrombectomy.


Assuntos
Arteriopatias Oclusivas/patologia , Arteriopatias Oclusivas/terapia , Procedimentos Endovasculares/métodos , Nanopartículas/administração & dosagem , Resistência ao Cisalhamento , Animais , Bovinos , Terapia Combinada , Feminino , Masculino , Nanopartículas/química , Coelhos , Resultado do Tratamento
19.
Radiology ; 277(3): 663-84, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26599926

RESUMO

This topical review on digital breast tomosynthesis (DBT) is provided with the intent of describing the state of the art in terms of technology, results from recent clinical studies, advanced applications, and ongoing efforts to develop multimodality imaging systems that include DBT. Particular emphasis is placed on clinical studies. The observations of increase in cancer detection rates, particularly for invasive cancers, and the reduction in false-positive rates with DBT in prospective trials indicate its benefit for breast cancer screening. Retrospective multireader multicase studies show either noninferiority or superiority of DBT compared with mammography. Methods to curtail radiation dose are of importance. (©) RSNA, 2015.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Mamografia/métodos , Intensificação de Imagem Radiográfica/métodos , Adulto , Detecção Precoce de Câncer , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Pessoa de Meia-Idade , Doses de Radiação , Estudos Retrospectivos
20.
Abdom Imaging ; 40(5): 1223-9, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25367814

RESUMO

PURPOSE: To analyze the effect of lobe selection, needle gauge, and number of passes on procedure outcomes in terms of specimen length and post-procedure complications. METHODS: In this HIPAA-compliant, IRB-approved retrospective study, the data from 771 ultrasound-guided adult parenchymal liver biopsies were analyzed. Post-procedure complications were assigned a 3-point rating scale. Associations between specimen length and post-procedure complications with lobe laterality, needle gauge, and number of passes were analyzed. Multivariate logistic regression models were used to analyze the likelihood for achieving a specimen length of at least 2 cm. RESULTS: Post-procedure complications were not associated with lobe laterality, needle gauge, and number of passes (p > 0.3). Specimen length was associated with the number of passes dichotomized at the study mean (p = 0.007), but not with lobe laterality or needle gauge (p > 0.2). After adjusting for lobe laterality and needle gauge, procedures with 1 or 2 passes were associated with a higher likelihood of obtaining a 2 cm or longer specimen (OR 2.469; CI 1.08-5.63, p = 0.0315) than procedures with 3 or more passes, possibly due to poorer sample quality. After adjusting for lobe laterality, an 18-gauge needle was associated with higher odds of a biopsy procedure with 1 or 2 passes (OR 3.665; CI 1.93-6.95, p < 0.0001) than a 20-gauge needle. CONCLUSIONS: Lobe laterality was not associated with specimen length or post-procedure complications. An 18-gauge needle compared to a 20-gauge needle could reduce the need for a procedure with more than 2 passes. There was no difference in post-procedure complications between the two needle sizes.


Assuntos
Biópsia por Agulha/instrumentação , Biópsia por Agulha/métodos , Fígado/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Biópsia Guiada por Imagem , Masculino , Pessoa de Meia-Idade , Agulhas , Seleção de Pacientes , Estudos Retrospectivos , Ultrassonografia de Intervenção , Adulto Jovem
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