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OBJECTIVE: Although multidisciplinary clinics improve outcomes in chronic limb-threatening ischemia (CLTI), their role in addressing socioeconomic disparities is unknown. Our institution treats patients with CLTI at both traditional general vascular clinics and a multidisciplinary Limb Preservation Program (LPP). The LPP is in a minority community, providing expedited care at a single facility by a consistent team. We compared outcomes within the LPP with our institution's traditional clinics and explored patients' perspectives on barriers to care to evaluate if the LPP might address them. METHODS: All patients undergoing index revascularization for CLTI from 2014 to 2023 at our institution were stratified by clinic type (LPP or traditional). We collected clinical and socioeconomic variables, including Area Deprivation Index (ADI). Patient characteristics were compared using χ2, Student t, or Mood median tests. Outcomes were compared using log-rank and multivariable Cox analysis. We also conducted semi-structured interviews to understand patient-perceived barriers. RESULTS: From 2014 to 2023, 983 limbs from 871 patients were revascularized; 19.5% of limbs were treated within the LPP. Compared with traditional clinic patients, more LPP patients were non-White (43.75% vs 27.43%; P < .0001), diabetic (82.29% vs 61.19%; P < .0001), dialysis-dependent (29.17% vs 13.40%; P < .0001), had ADI in the most deprived decile (29.38% vs 19.54%; P = .0061), resided closer to clinic (median 6.73 vs 28.84 miles; P = .0120), and had worse Wound, Ischemia, and foot Infection (WIfI) stage (P < .001). There were no differences in freedom from death, major adverse limb event (MALE), or patency loss. Within the most deprived subgroup (ADI >90), traditional clinic patients had earlier patency loss (P = .0108) compared with LPP patients. Multivariable analysis of the entire cohort demonstrated that increasing age, heart failure, dialysis, chronic obstructive pulmonary disease, and increasing WIfI stage were independently associated with earlier death, and male sex was associated with earlier MALE. Ten traditional clinic patients were interviewed via convenience sampling. Emerging themes included difficulty understanding their disease, high visit frequency, transportation barriers, distrust of the health care system, and patient-physician racial discordance. CONCLUSIONS: LPP patients had worse comorbidities and socioeconomic deprivation yet had similar outcomes to healthier, less deprived non-LPP patients. The multidisciplinary clinic's structure addresses several patient-perceived barriers. Its proximity to disadvantaged patients and ability to conduct multiple appointments at a single visit may address transportation and visit frequency barriers, and the consistent team may facilitate patient education and improve trust. Including these elements in a multidisciplinary clinic and locating it in an area of need may mitigate some negative impacts of socioeconomic deprivation on CLTI outcomes.
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BACKGROUND: The prevalence of chronic limb-threatening ischemia (CLTI) has increased alongside rising rates of diabetes mellitus (DM). While diabetic patients with CLTI have worse outcomes compared to patients without diabetes, conflicting data exist on the relationship between the severity of DM and CLTI outcomes. Close inspection of the relationship between DM severity and outcomes in CLTI may benefit surgical decision-making and patient education. METHODS: We retrospectively reviewed patients who received endovascular intervention or surgical bypass for CLTI at our multidisciplinary Limb Preservation Program from 2013 to 2019 to collect patient characteristics using Society for Vascular Surgery (SVS) reporting standards, arterial lesion characteristics from recorded angiograms, and outcomes, including survival, amputation, wound healing, and revascularization patency. Controlled DM was defined as SVS Grade 1 (controlled, not requiring insulin) and Grade 2 (controlled, requiring insulin), while uncontrolled DM was defined as SVS Grade 3 (uncontrolled), and DM severity was assessed using preoperative hemoglobin A1c (HgbA1c) values. Product-limit Kaplan-Meier was used to estimate survival functions. Univariable Cox proportional hazards analyses guided variable selection for multivariable analyses. RESULTS: Our Limb Preservation Program treated 177 limbs from 141 patients with DM. Patients with uncontrolled DM were younger (60.44 ± 10.67 vs. 65.93 ± 10.89 years old, P = 0.0009) and had higher HgbA1c values (8.97 ± 1.85% vs. 6.79 ± 1.10%, P < 0.0001). Fewer patients with uncontrolled DM were on dialysis compared to patients with controlled DM (15.6% vs. 30.9%, P = 0.0278). By Kaplan-Meier analysis, DM control did not affect time to mortality, limb salvage, wound healing, or loss of patency. However, multivariable proportional hazards analysis demonstrated increased risk of limb loss in patients with increasing HgbA1C (hazard ratio (HR) = 1.96 [1.42-2.80], P < 0.0001) or dialysis dependence (HR = 15.37 [3.44-68.73], P = 0.0003), increased risk of death in patients with worsening pulmonary status (HR = 1.70 [1.20-2.39], P = 0.0026), and increased risk of delayed wound healing in patients who are male (HR = 0.48 [0.29-0.79], P = 0.0495). No independent association existed between loss of patency with any of the variables we collected. CONCLUSIONS: Patients with uncontrolled DM, as defined by SVS reporting standards, do not have worse outcomes following revascularization for CLTI compared to patients with controlled DM. However, increasing HgbA1c is associated with a greater risk for early amputation. Before revascularization, specific attention to the level of glycemic control in patients with DM is important, even if DM is "controlled." In addition to aggressive attempts at improved glycemic control, those with elevated HgbA1c should receive careful education regarding their increased risk of amputation despite revascularization. Future work is necessary to incorporate the severity of DM into risk models of revascularization for the CLTI population.
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Diabetes Mellitus , Procedimentos Endovasculares , Doença Arterial Periférica , Humanos , Masculino , Pessoa de Meia-Idade , Idoso , Feminino , Isquemia Crônica Crítica de Membro , Controle Glicêmico , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento , Isquemia/diagnóstico por imagem , Isquemia/cirurgia , Doença Arterial Periférica/diagnóstico por imagem , Doença Arterial Periférica/terapia , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/epidemiologia , Procedimentos Cirúrgicos Vasculares/efeitos adversos , Salvamento de Membro , Insulina , Procedimentos Endovasculares/efeitos adversosRESUMO
Peripheral artery disease (PAD) is classified as the narrowing or complete occlusion of the lower extremity arteries due to atherosclerosis. The risk of developing PAD increases with increased age and risk factors such as smoking, diabetes, hypertension, and hypercholesterolemia. Current treatment for PAD involves lifestyle and symptom management, statin and antiplatelet therapy, and/or surgical interventions to improve quality of life with varying efficacy. PAD affects approximately 5 to 6 percent of the global population, with this global burden continuing to increase. Despite the increase in disease prevalence, no gold standard functional diagnostic tool has been established for enabling early detection of the disease, appropriate medical management, and prediction of adverse outcomes for PAD patients. The visualization and quantification of the physiological consequences of PAD are possible by way of nuclear imaging: specifically, via scintigraphy, single-photon emission computed tomography (SPECT), and positron emission tomography (PET) imaging. These non-invasive modalities, when combined with targeted radionuclides, possess utility for detecting functional perfusion deficits and provide unique insight into muscle tissue- and vascular-level characteristics of PAD patients. This review discusses the past, present, and emerging applications of hybrid nuclear imaging modalities in the evaluation and monitoring of patients with PAD.
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Extremidade Inferior , Doença Arterial Periférica , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada de Emissão de Fóton Único , Humanos , Doença Arterial Periférica/diagnóstico por imagem , Doença Arterial Periférica/diagnóstico , Extremidade Inferior/diagnóstico por imagem , Extremidade Inferior/irrigação sanguínea , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Tomografia por Emissão de Pósitrons/métodosRESUMO
OBJECTIVES: The treatment for chronic limb-threatening ischemia (CLTI) has changed dramatically in the last few decades with a shift toward an endovascular-first approach and aggressive revascularization to achieve limb salvage. As the size of the CLTI population and intervention rates increase, patients will continue to experience technical failure (TF). Here, we describe the natural history of patients after TF of endovascular intervention for CLTI. METHODS: We conducted a retrospective cohort study of patients with CLTI who attempted endovascular intervention or bypass at our multidisciplinary limb salvage center from 2013 to 2019. Patient characteristics were collected according to the Society for Vascular Surgery's reporting standards. Primary outcomes included survival, limb salvage, wound healing, and revascularization patency. Product-limit Kaplan-Meier estimated survival functions for these outcomes, and between-group comparisons were made using Mantel-Cox log-rank nonparametric tests. RESULTS: We identified 242 limbs from 220 unique patients who underwent primary bypass (n = 30) or attempted endovascular intervention (n = 212) at our limb salvage center. Endovascular intervention was a TF in 31 (14.6%) limbs. After TF, 13 limbs underwent secondary bypass and 18 limbs were managed medically. Patients who experienced TF tended to be older (P < .001), male (P = .003), current tobacco users (P = .014), have longer lesions (P = .001), and have chronic total occlusions of target arteries (P < .001) as compared with those who experienced technical success. Furthermore, the TF group had worse limb salvage (P = .047) and slower wound healing (P = .028), but their survival was not different. Survival, limb salvage, and wound healing were not different in patients who received secondary bypass or medical management after TF. The secondary bypass group was older (P = .012) and had a lower prevalence of tibial disease (P = .049) than the primary bypass group and trended toward decreased survival, limb salvage, and wound healing (P = .059, P = .083, and P = .051, respectively). CONCLUSIONS: Increased age, male sex, current tobacco use, longer arterial lesions, and occluded target arteries are associated with TF of endovascular intervention. Limb salvage and wound healing are relatively poor after TF of endovascular intervention, but survival appears comparable with patients who experience technical success. Secondary bypass may not always rescue patients after TF, though our sample size limits statistical power. Interestingly, patients who received a secondary bypass after TF trended toward decreased survival, limb salvage, and wound healing compared with primary bypass.
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Procedimentos Endovasculares , Doença Arterial Periférica , Humanos , Masculino , Isquemia Crônica Crítica de Membro , Resultado do Tratamento , Estudos Retrospectivos , Fatores de Risco , Procedimentos Endovasculares/efeitos adversos , Doença Arterial Periférica/diagnóstico por imagem , Doença Arterial Periférica/terapia , Amputação Cirúrgica , Isquemia/diagnóstico por imagem , Isquemia/etiologia , Isquemia/cirurgia , Salvamento de Membro , Grau de Desobstrução VascularRESUMO
OBJECTIVES: The objective of this study was to translate a deep learning (DL) approach for semiautomated analysis of body composition (BC) measures from standard of care CT images to investigate the prognostic value of BC in pediatric, adolescent, and young adult (AYA) patients with lymphoma. METHODS: This 10-year retrospective, single-site study of 110 pediatric and AYA patients with lymphoma involved manual segmentation of fat and muscle tissue from 260 CT imaging datasets obtained as part of routine imaging at initial staging and first therapeutic follow-up. A DL model was trained to perform semiautomated image segmentation of adipose and muscle tissue. The association between BC measures and the occurrence of 3-year late effects was evaluated using Cox proportional hazards regression analyses. RESULTS: DL-guided measures of BC were in close agreement with those obtained by a human rater, as demonstrated by high Dice scores (≥ 0.95) and correlations (r > 0.99) for each tissue of interest. Cox proportional hazards regression analyses revealed that patients with elevated subcutaneous adipose tissue at baseline and first follow-up, along with patients who possessed lower volumes of skeletal muscle at first follow-up, have increased risk of late effects compared to their peers. CONCLUSIONS: DL provides rapid and accurate quantification of image-derived measures of BC that are associated with risk for treatment-related late effects in pediatric and AYA patients with lymphoma. Image-based monitoring of BC measures may enhance future opportunities for personalized medicine for children with lymphoma by identifying patients at the highest risk for late effects of treatment. KEY POINTS: ⢠Deep learning-guided CT image analysis of body composition measures achieved high agreement level with manual image analysis. ⢠Pediatric patients with more fat and less muscle during the course of cancer treatment were more likely to experience a serious adverse event compared to their clinical counterparts. ⢠Deep learning of body composition may add value to routine CT imaging by offering real-time monitoring of pediatric, adolescent, and young adults at high risk for late effects of cancer treatment.
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Composição Corporal , Aprendizado Profundo , Linfoma , Adolescente , Criança , Humanos , Progressão da Doença , Linfoma/diagnóstico por imagem , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Masculino , Feminino , Modelos de Riscos Proporcionais , Valor Preditivo dos TestesRESUMO
OBJECTIVE: Drug-coated balloons (DCB) and drug-eluting stents (DES) have been rapidly adopted for femoropopliteal endovascular interventions due to their favorable patency rates. It is unclear whether choice of using drug coated devices versus bare metal stents (BMS) or plain balloon angioplasty (POBA) as primary treatment in femoropopliteal disease is mostly associated with patient-level factors, safety concerns, or by operator preferences. This study sought to evaluate factors associated with their use in a contemporary dataset. METHODS: All femoropopliteal lesions treated with endovascular interventions between 2016 and 2019 from the Vascular Quality Initiative registry were included. For each procedure, a primary treatment was identified based on the following hierarchy: DES > DCB > BMS > POBA. A hierarchical logistic regression model predicting DCB or DES use included patient-level characteristics, key events (period after Centers for Medicare and Medicaid Services reimbursement change, January 2018 [vs before] and period after Katsanos meta-analysis December 2018 [vs before]), and random effects for site and operator. Operator-level variability for DCB and DES use was summarized with an adjusted median odds ratio (MOR). RESULTS: A total of 57,753 femoropopliteal endovascular procedures were included. Poor functional status (odds ratio [OR], 0.92; 95% confidence interval [CI], 0.90-0.94), prior anticoagulant use (OR, 0.92; 95% CI, 0.87-0.97), higher Rutherford classification (OR, 0.86; 95% CI, 0.84-0.88), chronic kidney disease stage 4 or 5 (OR, 0.92; 95% CI, 0.86-0.98), and the period after the Katsanos meta-analysis publication (OR, 0.3; 95% CI, 0.29-0.32) were associated with a lower odds of DCB or DES use; whereas female sex (OR, 1.12; 95% CI,1.08-1.17), prior lesion treatment (OR, 1.17; 95% CI, 1.11-1.22), diabetes (OR, 1.07; 95% CI, 1.02-1.12), Trans-Atlantic Inter-Society Consensus class B (OR, 1.16; 95% CI, 1.09-1.24) and C (OR, 1.2; 95% CI, 1.12-1.28), and the period after the Centers for Medicare and Medicaid Services reimbursement change (OR, 1.08; 95% CI, 1.03-1.14) were associated with a higher odds of DCB or DES use. Significant variability in use was found across operators (adjusted MOR, 2.70; 95% CI, 2.55-2.85) and centers (adjusted MOR, 2.89; 95% CI, 2.50-3.27). CONCLUSIONS: DCB or DES use in femoropopliteal disease demonstrates wide variability across operators and is linked strongly with external factors, followed by anatomic lesion characteristics and a history of previous interventions. Future work needs to focus on tailoring DCB or DES use to patient and lesion characteristics and to develop appropriate use guidelines integrating these factors.
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Angioplastia com Balão , Stents Farmacológicos , Doença Arterial Periférica , Idoso , Feminino , Humanos , Estados Unidos , Artéria Poplítea , Doença Arterial Periférica/diagnóstico por imagem , Doença Arterial Periférica/terapia , Medicare , Artéria Femoral/cirurgia , Angioplastia com Balão/efeitos adversos , Resultado do Tratamento , Materiais Revestidos Biocompatíveis , Grau de Desobstrução VascularRESUMO
OBJECTIVES: The objective of this study was to use computed tomography (CT) imaging to quantify chemotherapy-induced changes in body composition (BC) in pediatric, adolescent, and young adult (AYA) patients with lymphoma and to compare image-derived changes in BC measures to changes in traditional body mass index (BMI) measures. METHODS: Skeletal muscle (SkM), subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) volumes were manually segmented using low-dose CT images acquired from a 10-year retrospective, single-site cohort of 110 patients with lymphoma. CT images and BMI percentiles (BMI%) were acquired from baseline and first therapeutic follow-up. CT image segmentation was performed at vertebral level L3 using 5 consecutive axial CT images. RESULTS: CT imaging detected significant treatment-induced changes in BC measures from baseline to first follow-up time points, with SAT and VAT significantly increasing and SkM significantly decreasing. BMI% measures did not change from baseline to first follow-up and were not significantly correlated with changes in image-derived BC measures. Patients who were male, younger than 12 years old, diagnosed with non-Hodgkin's lymphoma, and presented with stage 3 or 4 disease gained more adipose tissue and lost more SkM in response to the first cycle of treatment compared to their clinical counterparts. CONCLUSIONS: Standard of care CT imaging can quantify treatment-induced changes in BC that are not reflected by traditional BMI assessment. Image-based monitoring of BC parameters may offer personalized approaches to lymphoma treatment for pediatric and AYA patients by guiding cancer treatment recommendations and subsequently enhance clinical outcomes. KEY POINTS: ⢠Standard of care low-dose CT imaging quantifies chemotherapy-induced changes in body composition in pediatric, adolescent, and young adults with lymphoma. ⢠Body mass index could not detect changes in body composition during treatment that were quantified by CT imaging. ⢠Pediatric and AYA patients who were male, younger than 12 years old, and diagnosed with non-Hodgkin's lymphoma, and presented with stage 3 or 4 disease gained more adipose tissue and lost more skeletal muscle tissue in response to the first cycle of treatment compared to their clinical counterparts.
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Antineoplásicos , Linfoma não Hodgkin , Linfoma , Adolescente , Composição Corporal , Criança , Feminino , Humanos , Linfoma/diagnóstico por imagem , Linfoma/tratamento farmacológico , Linfoma não Hodgkin/diagnóstico por imagem , Linfoma não Hodgkin/tratamento farmacológico , Masculino , Estudos Retrospectivos , Padrão de Cuidado , Tomografia Computadorizada por Raios X/métodos , Adulto JovemRESUMO
BACKGROUND: Although exercise is often prescribed for the management of cardiovascular diseases, a non-invasive imaging approach that quantifies skeletal muscle physiology and correlates with patients' functional capacity and cardiovascular fitness has been absent. Therefore, we evaluated the potential of lower extremity single photon emission computed tomography (SPECT)/CT perfusion imaging as a non-invasive correlate to exercise tolerance and cardiovascular fitness. METHODS: Patients (n = 31) undergoing SPECT/CT myocardial perfusion imaging underwent additional stress/rest SPECT/CT imaging of the lower extremities. CT-based image segmentation was used for regional quantification of perfusion reserve within the tibialis anterior, soleus, and gastrocnemius muscles. Metabolic equivalents (METs) at peak exercise and heart rate recovery (HRR) after exercise were recorded. RESULTS: Peak METs were significantly associated with perfusion reserve of tibialis anterior (p = 0.02), soleus (p = 0.01) and gastrocnemius (p = 0.01). HRR was significantly associated with perfusion reserve of the soleus (p = 0.02) and gastrocnemius (p = 0.04) muscles. Perfusion reserve of the tibialis anterior (40.6 ± 20.2%), soleus (35.4 ± 16.7%), and gastrocnemius (29.7 ± 19.1%) all significantly differed from each other. CONCLUSIONS: SPECT/CT imaging provides regional quantification of skeletal muscle perfusion reserve which is significantly associated with exercise tolerance and cardiovascular fitness. Future application of SPECT/CT may elucidate the underlying skeletal muscle adapations to exercise therapy in patients with cardiovascular diseases.
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Tolerância ao Exercício , Extremidade Inferior/irrigação sanguínea , Músculo Esquelético/diagnóstico por imagem , Imagem de Perfusão do Miocárdio/métodos , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único/métodos , Idoso , Sistema Cardiovascular , Exercício Físico , Teste de Esforço , Feminino , Frequência Cardíaca , Hemodinâmica , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Compostos Organofosforados , Compostos de Organotecnécio , PerfusãoRESUMO
BACKGROUND: High resolution 3D T1 mapping is important for assessment of diffuse myocardial fibrosis in left atrium or other thin-walled structures. In this work, we investigated a fast single-TI 3D high resolution T1 mapping method that directly transforms a 3D late gadolinium enhancement (LGE) volume to a 3D T1 map. METHODS: The proposed method, T1-refBlochi, is based on Bloch equation modeling of the LGE signal, a single-point calibration, and assumptions that proton density and T2* are relatively uniform in the heart. Several sources of error of this method were analyzed mathematically and with simulations. Imaging was performed in phantoms, eight swine and five patients, comparing T1-refBlochi to a standard spin-echo T1 mapping, 3D multi-TI T1 mapping, and 2D ShMOLLI, respectively. RESULTS: The method has a good accuracy and adequate precision, even considering various sources of error. In phantoms, over a range of protocols, heart-rates and T1 s, the bias ±1SD was -3 ms ± 9 ms. The porcine studies showed excellent agreement between T1-refBlochi and the multi-TI method (bias ±1SD = -6 ± 22 ms). The proton density and T2* weightings yielded ratios for scar/blood of 0.94 ± 0.01 and for myocardium/blood of 1.03 ± 0.02 in the eight swine, confirming that sufficient uniformity of proton density and T2* weightings exists among heterogeneous tissues of the heart. In the patients, the mean T1 bias ±1SD in myocardium and blood between T1-refBlochi and ShMOLLI was -9 ms ± 21 ms. CONCLUSION: T1-refBlochi provides a fast single-TI high resolution 3D T1 map of the heart with good accuracy and adequate precision.
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Cardiomiopatias/diagnóstico por imagem , Meios de Contraste/administração & dosagem , Átrios do Coração/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Compostos Organometálicos/administração & dosagem , Algoritmos , Animais , Cardiomiopatias/patologia , Simulação por Computador , Estudos de Viabilidade , Feminino , Fibrose , Átrios do Coração/patologia , Humanos , Imageamento por Ressonância Magnética/instrumentação , Masculino , Pessoa de Meia-Idade , Modelos Cardiovasculares , Método de Monte Carlo , Imagens de Fantasmas , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Sus scrofaRESUMO
The steroid receptor coactivator 1 (SRC1) regulates key metabolic pathways, including glucose homeostasis. SRC1(-/-) mice have decreased hepatic expression of gluconeogenic enzymes and a reduction in the rate of endogenous glucose production (EGP). We sought to determine whether decreasing hepatic and adipose SRC1 expression in normal adult rats would alter glucose homeostasis and insulin action. Regular chow-fed and high-fat-fed male Sprage-Dawley rats were treated with an antisense oligonucleotide (ASO) against SRC1 or a control ASO for 4 wk, followed by metabolic assessments. SRC1 ASO did not alter basal EGP or expression of gluconeogenic enzymes. Instead, SRC1 ASO increased insulin-stimulated whole body glucose disposal by ~30%, which was attributable largely to an increase in insulin-stimulated muscle glucose uptake. This was associated with an approximately sevenfold increase in adipose expression of lipocalin-type prostaglandin D2 synthase, a previously reported regulator of insulin sensitivity, and an approximately 70% increase in plasma PGD2 concentration. Muscle insulin signaling, AMPK activation, and tissue perfusion were unchanged. Although GLUT4 content was unchanged, SRC1 ASO increased the cleavage of tether-containing UBX domain for GLUT4, a regulator of GLUT4 translocation. These studies point to a novel role of adipose SRC1 as a regulator of insulin-stimulated muscle glucose uptake.
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Inibidores Enzimáticos/uso terapêutico , Intolerância à Glucose/tratamento farmacológico , Resistência à Insulina , Músculo Esquelético/efeitos dos fármacos , Coativador 1 de Receptor Nuclear/antagonistas & inibidores , Oligodesoxirribonucleotídeos Antissenso/uso terapêutico , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/enzimologia , Tecido Adiposo/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Dieta Hiperlipídica/efeitos adversos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Intolerância à Glucose/etiologia , Intolerância à Glucose/metabolismo , Transportador de Glucose Tipo 4/agonistas , Transportador de Glucose Tipo 4/química , Transportador de Glucose Tipo 4/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/agonistas , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Oxirredutases Intramoleculares/genética , Oxirredutases Intramoleculares/metabolismo , Lipocalinas/agonistas , Lipocalinas/genética , Lipocalinas/metabolismo , Fígado/efeitos dos fármacos , Fígado/enzimologia , Fígado/metabolismo , Masculino , Músculo Esquelético/metabolismo , Coativador 1 de Receptor Nuclear/genética , Coativador 1 de Receptor Nuclear/metabolismo , Fosfoenolpiruvato Carboxiquinase (GTP)/genética , Fosfoenolpiruvato Carboxiquinase (GTP)/metabolismo , Prostaglandina D2/sangue , Prostaglandina D2/metabolismo , Domínios e Motivos de Interação entre Proteínas , Proteólise/efeitos dos fármacos , Ratos Sprague-DawleyRESUMO
Advancements in congenital heart surgery have heightened the importance of durable biomaterials for adult survivors. Dystrophic calcification poses a significant risk to the long-term viability of prosthetic biomaterials in these procedures. Herein, we describe the natural history of calcification in the most frequently used vascular conduits, expanded polytetrafluoroethylene grafts. Through a retrospective clinical study and an ovine model, we compare the degree of calcification between tissue-engineered vascular grafts and polytetrafluoroethylene grafts. Results indicate superior durability in tissue-engineered vascular grafts, displaying reduced late-term calcification in both clinical studies (p < 0.001) and animal models (p < 0.0001). Further assessments of graft compliance reveal that tissue-engineered vascular grafts maintain greater compliance (p < 0.0001) and distensibility (p < 0.001) than polytetrafluoroethylene grafts. These properties improve graft hemodynamic performance, as validated through computational fluid dynamics simulations. We demonstrate the promise of tissue engineered vascular grafts, remaining compliant and distensible while resisting long-term calcification, to enhance the long-term success of congenital heart surgeries.
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Prótese Vascular , Calcinose , Ovinos , Animais , Estudos Retrospectivos , Calcinose/cirurgia , Materiais Biocompatíveis , PolitetrafluoretilenoRESUMO
BACKGROUND: Perfusion deficits contribute to symptom severity, morbidity, and death in peripheral artery disease (PAD); however, no standard method for quantifying absolute measures of skeletal muscle perfusion exists. This study sought to preclinically test and clinically translate a positron emission tomography (PET) imaging approach using an atherosclerosis-targeted radionuclide, fluorine-18-sodium fluoride (18F-NaF), to quantify absolute perfusion in PAD. METHODS AND RESULTS: Eight Yorkshire pigs underwent unilateral femoral artery ligation and dynamic 18F-NaF PET/computed tomography imaging on the day of and 2 weeks after occlusion. Following 2-week imaging, calf muscles were harvested to quantify microvascular density. PET methodology was validated with microspheres in 4 additional pig studies and translated to patients with PAD (n=39) to quantify differences in calf perfusion across clinical symptoms/stages and perfusion responses in a case of revascularization. Associations between PET perfusion, ankle-brachial index, toe-brachial index, and toe pressure were assessed in relation to symptoms. 18F-NaF PET/computed tomography quantified significant deficits in calf perfusion in pigs following arterial occlusion and perfusion recovery 2 weeks after occlusion that coincided with increased muscle microvascular density. Additional studies confirmed that PET-derived perfusion measures agreed with microsphere-derived perfusion measures. Translation of imaging methods demonstrated significant decreases in calf perfusion with increasing severity of PAD and quantified perfusion responses to revascularization. Perfusion measures were also significantly associated with symptom severity, whereas traditional hemodynamic measures were not. CONCLUSIONS: 18F-NaF PET imaging quantifies perfusion deficits that correspond to clinical stages of PAD and represents a novel perfusion imaging strategy that could be partnered with atherosclerosis-targeted 18F-NaF PET imaging using a single radioisotope injection. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03622359.
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Músculo Esquelético , Doença Arterial Periférica , Animais , Humanos , Músculo Esquelético/diagnóstico por imagem , Perfusão , Doença Arterial Periférica/diagnóstico por imagem , Tomografia por Emissão de Pósitrons/métodos , Fluoreto de Sódio , SuínosRESUMO
Following myocardial infarction (MI), maladaptive upregulation of matrix metalloproteinase (MMP) alters extracellular matrix leading to cardiac remodeling. Intramyocardial hydrogel delivery provides a vehicle for local delivery of MMP tissue inhibitors (rTIMP-3) for MMP activity modulation. We evaluated swine 10-14 days following MI randomized to intramyocardial delivery of saline, degradable hyaluronic acid (HA) hydrogel, or rTIMP-3 releasing hydrogel with an MMP-targeted radiotracer (99mTc-RP805), 201Tl, and CT. Significant left ventricle (LV) wall thinning, increased wall stress, reduced circumferential wall strain occurred in the MI region of MI-Saline group along with left atrial (LA) dilation, while these changes were modulated in both hydrogel groups. 99mTc-RP805 activity increased twofold in MI-Saline group and attenuated in hydrogel animals. Infarct size significantly reduced only in rTIMP-3 hydrogel group. Hybrid SPECT/CT imaging demonstrated a therapeutic benefit of intramyocardial delivery of hydrogels post-MI and reduced remodeling of LA and LV in association with a reduction in MMP activation.
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Hidrogéis , Infarto do Miocárdio , Animais , Hidrogéis/uso terapêutico , Metaloproteinases da Matriz/uso terapêutico , Miocárdio , Suínos , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada por Raios X , Remodelação Ventricular/fisiologiaRESUMO
Vascular calcification contributes to morbidity and poor clinical outcomes for patients with peripheral artery disease; however, the traditional assessment of the calcium burden using computed tomography (CT) imaging or angiography represents already established disease. In the present report, we describe a 69-year-old man with chronic limb-threatening ischemia who had undergone positron emission tomography/CT imaging with fluorine-18 sodium fluoride to evaluate the relationship between baseline levels of positron emission tomography-detectable active vascular microcalcification and CT-detectable calcium progression 1.5 years later. CT imaging at follow-up identified progression of existing lesions and the formation of new calcium in multiple arteries that had demonstrated elevated fluorine-18 sodium fluoride uptake 1.5 years earlier.
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BACKGROUND: Positron emission tomography (PET)/computed tomography (CT) imaging with fluorine-18 (18F)-sodium fluoride (NaF) provides assessment of active vascular microcalcification, but its utility for evaluating diabetes mellitus (DM)- and chronic kidney disease (CKD)-induced atherosclerosis in peripheral arterial disease (PAD) has not been comprehensively evaluated. This study sought to use 18F-NaF PET/CT to quantify and compare active microcalcification on an artery-by-artery basis in healthy subjects, PAD patients with or without DM, and PAD patients with or without CKD. Additionally, we evaluated the contributions of DM, CKD, statin use and established CT-detectable calcium to 18F-NaF uptake for each lower extremity artery. METHODS: PAD patients (n = 48) and healthy controls (n = 8) underwent lower extremity 18F-NaF PET/CT imaging. Fused PET/CT images guided segmentation of arteries of interest (i.e., femoral-popliteal, anterior tibial, tibioperoneal trunk, posterior tibial, and peroneal) and quantification of 18F-NaF uptake. 18F-NaF uptake was assessed for each artery and compared between subject groups. Additionally, established calcium burden was quantified for each artery using CT calcium mass score. Univariate and multivariate analyses were performed to evaluate DM, CKD, statin use, and CT calcium mass as predictors of 18F-NaF uptake in PAD. RESULTS: PAD patients with DM or CKD demonstrated significantly higher active microcalcification (i.e., 18F-NaF uptake) for all arteries when compared to PAD patients without DM or CKD. Univariate and multivariate analyses revealed that concomitant DM or CKD was associated with increased microcalcification for all arteries of interest and this increased disease risk remained significant after adjusting for patient age, sex, and body mass index. Statin use was only associated with decreased microcalcification for the femoral-popliteal artery in multivariate analyses. Established CT-detectable calcium was not significantly associated with 18F-NaF uptake for 4 out of 5 arteries of interest. CONCLUSIONS: 18F-NaF PET/CT imaging quantifies vessel-specific active microcalcification in PAD that is increased in multiple lower extremity arteries by DM and CKD and decreased in the femoral-popliteal artery by statin use. 18F-NaF PET imaging is complementary to and largely independent of established CT-detectable arterial calcification. 18F-NaF PET/CT imaging may provide an approach for non-invasively quantifying vessel-specific responses to emerging anti-atherogenic therapies or CKD treatment in patients with PAD.
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Objective: Peripheral artery disease (PAD) is associated with increased risk of nonhealing ulcers, amputation, and mortality due to occlusive atherosclerotic plaques. Computed tomography (CT) imaging detects vascular calcification in PAD; however, quantitative vessel-by-vessel analysis of calcium burden in the feet of PAD patients has not been assessed. This study sought to perform quantitative analysis of vessel-specific calcium burden and examine the patient-level determinants of foot calcium burden in PAD patients. Approach: PAD patients (n = 41) were prospectively enrolled and underwent CT imaging of the lower extremities. Manual segmentation of the medial plantar, lateral plantar, and dorsalis pedis arteries was performed. CT image Hounsfield units (HUs) were obtained for each artery to quantify vessel-by-vessel calcium mass using a cutoff value of ≥130 HU. Univariate analyses were performed to evaluate patient-level determinants of calcium burden for each foot artery. STROBE guidelines were used for reporting of data. Results: Univariate analyses revealed that body mass index, diabetes mellitus (DM), and chronic kidney disease (CKD) were significant determinants of foot calcium burden in PAD patients. Image analysis demonstrated that PAD patients with DM had significantly higher calcium mass for the medial plantar (p = 0.005), lateral plantar (p = 0.039), and dorsalis pedis (p = 0.001) arteries compared with PAD patients without DM. Innovation: This is the first study to use CT imaging to quantify vessel-specific calcium burden in the feet of patients with PAD and evaluate the patient-level determinants of foot calcium burden in the setting of PAD. Conclusion: CT imaging quantifies vessel-specific calcification in the feet of PAD patients, which is exacerbated with concomitant DM, CKD, and/or obesity.
Assuntos
Diabetes Mellitus , Doença Arterial Periférica , Insuficiência Renal Crônica , Humanos , Cálcio , Doença Arterial Periférica/diagnóstico por imagem , Doença Arterial Periférica/complicações , Extremidade Inferior , Insuficiência Renal Crônica/diagnóstico por imagem , Insuficiência Renal Crônica/complicações , Tomografia Computadorizada por Raios X , TomografiaRESUMO
OBJECTIVES/HYPOTHESIS: Partially decellularized tracheal scaffolds have emerged as a potential solution for long-segment tracheal defects. These grafts have exhibited regenerative capacity and the preservation of native mechanical properties resulting from the elimination of all highly immunogenic cell types while sparing weakly immunogenic cartilage. With partial decellularization, new considerations must be made about the viability of preserved chondrocytes. In this study, we propose a multimodal approach for quantifying chondrocyte viability for airway tissue engineering. METHODS: Tracheal segments (5 mm) were harvested from C57BL/6 mice, and immediately stored in phosphate-buffered saline at -20°C (PBS-20) or biobanked via cryopreservation. Stored and control (fresh) tracheal grafts were implanted as syngeneic tracheal grafts (STG) for 3 months. STG was scanned with micro-computed tomography (µCT) in vivo. STG subjected to different conditions (fresh, PBS-20, or biobanked) were characterized with live/dead assay, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and von Kossa staining. RESULTS: Live/dead assay detected higher chondrocyte viability in biobanked conditions compared to PBS-20. TUNEL staining indicated that storage conditions did not alter the proportion of apoptotic cells. Biobanking exhibited a lower calcification area than PBS-20 in 3-month post-implanted grafts. Higher radiographic density (Hounsfield units) measured by µCT correlated with more calcification within the tracheal cartilage. CONCLUSIONS: We propose a strategy to assess chondrocyte viability that integrates with vivo imaging and histologic techniques, leveraging their respective strengths and weaknesses. These techniques will support the rational design of partially decellularized tracheal scaffolds. LEVEL OF EVIDENCE: N/A Laryngoscope, 133:512-520, 2023.
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Condrócitos , Engenharia Tecidual , Animais , Camundongos , Condrócitos/transplante , Engenharia Tecidual/métodos , Bancos de Espécimes Biológicos , Microtomografia por Raio-X , Camundongos Endogâmicos C57BL , Traqueia/cirurgia , Traqueia/transplante , Alicerces TeciduaisRESUMO
Microcomputed tomography (microCT) angiography is an invaluable resource to researchers. New advances in this technology have allowed for high-quality images to be obtained of micro-vasculature and are high-fidelity tools in the field of organ transplantation. In this model of orthotopic liver transplantation (OLT) in mice, microCT affords the opportunity to evaluate allograft anastomosis in real time and has the added benefit of not having to sacrifice study animals. The choice of contrast, as well as image acquisition settings, create a high-definition image, which gives researchers invaluable information. This allows for evaluation of the technical aspects of the procedure as well as potentially evaluating different therapeutics over an extended duration of time. In this protocol, we detail an OLT model in mice in a stepwise fashion and finally describe a microCT protocol that can give high-quality images, which aid researchers in in-depth analysis of solid organ transplantation. We provide a step-by-step guide for liver transplantation in a mouse, as well as briefly discuss a protocol for evaluating the patency of the graft through microCT angiography.
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Transplante de Fígado , Camundongos , Animais , Transplante de Fígado/métodos , Microtomografia por Raio-X , Angiografia , Angiografia por Tomografia Computadorizada , Anastomose CirúrgicaRESUMO
BACKGROUND: Positron emission tomography (PET)/computed tomography (CT) imaging can detect changes in arterial inflammation, but has not been used to evaluate chemotherapy-induced venous inflammation or assess risk for venous thromboembolism (VTE) in pediatric oncology. Therefore, the purpose of this study was to evaluate the prognostic value of fluorine-18-fluorodeoxyglucose PET/CT imaging of venous inflammation for predicting VTE occurrence in the 12 months after lymphoma diagnosis in pediatric, adolescent, and young adult patients. METHODS: Pediatric, adolescent, and young adult patients with lymphoma diagnoses (n=71) who underwent whole-body PET/CT imaging at initial staging of disease and first therapeutic follow-up were retrospectively evaluated for serial changes in lower extremity venous uptake of fluorine-18-fluorodeoxyglucose. PET/CT images were used to segment and quantify serial changes in fluorine-18-fluorodeoxyglucose uptake for veins of interest (ie, popliteal and femoral). Incidence of VTE was assessed for 12 months after lymphoma diagnosis. RESULTS: PET/CT detected a significantly higher inflammatory response in the femoral (P=0.012) and popliteal (P=0.013) veins of patients who experienced a VTE event compared with those who remained VTE free in the 12 months after diagnosis. The area under the curve values for receiver operator characteristics analyses were 0.76 (femoral vein) and 0.77 (popliteal vein) based on incidence of VTE occurrence. Univariate analyses demonstrated that PET/CT-derived changes in femoral (P=0.008) and popliteal (P=0.002) vein inflammation were significantly associated with VTE-free survival at 12 months after diagnosis. CONCLUSIONS: Fluorine-18-fluorodeoxyglucose PET/CT imaging detects treatment-induced venous toxicity that may provide insight into risk of VTE events in pediatric and adolescent and young adult patients with lymphoma.