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1.
J Pediatr Surg ; 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38879401

RESUMO

BACKGROUND: Childhood obesity is a devastating disease process disproportionately affecting minority and low-income populations. Though bariatric surgery leads to durable weight loss and reversal of multiple obesity-related comorbidities, only a small fraction of pediatric patients undergoes the procedure. We sought to identify factors associated with non-completion in a pediatric bariatric surgery program. METHODS: Retrospective review of consecutive patients ≤18-years-old referred to an academic adolescent bariatric surgery program between 2017 and 2022 (n = 20 completers, 40 non-completers) was completed. Demographics and medical and psychosocial histories were summarized by completion status. RESULTS: Of the 33% (20/60; 85% female, 30% racial minorities) who successfully completed the program, the median age was 16 years [IQR 16, 17]. The median age of non-completers was 16 years [IQR 15, 17] (55% female, 56% racial minorities). Non-completion was associated with male gender (15% of completers vs 45% of non-completers, p = 0.022), neighborhood income <150% poverty level (0 completers vs 17.5% of non-completers, p = 0.047), and presence of environmental or family stressors (22% of completers vs 65% of non-completers, p = 0.008). Though not statistically significant, non-completers tended to be racial minorities (p = 0.054). CONCLUSIONS: Non-completion of the bariatric surgery pathway was more prevalent among male patients from lower-income neighborhoods with significant environmental or family stressors. These patients also tended to be racial and ethnic minorities. The findings underscore the need for further investigation into barriers to pediatric bariatric surgery. LEVEL OF EVIDENCE: Level III.

2.
J Pediatr Hematol Oncol ; 45(8): e984-e987, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37565829

RESUMO

Understanding the molecular landscape of papillary thyroid carcinoma (PTC), the most common thyroid cancer in children, creates additional therapeutic approaches. RET gene rearrangements are observed in pediatric PTC, and selective inhibition of RET is now possible with specific tyrosine kinase inhibitors designed to target diverse RET -activating alterations. We present a 13-year-old female with metastatic PTC, clinically resistant to radioactive iodine, and found to harbor a NCOA4-RET fusion. She responded to selpercatinib treatment with the elimination of supplemental oxygen need, marked reduction in pulmonary nodules and mediastinal lymphadenopathy, and biomarker decline. The response was maintained despite 2 dose reductions for possibly related weight gain.


Assuntos
Neoplasias da Glândula Tireoide , Adolescente , Feminino , Humanos , Rearranjo Gênico , Radioisótopos do Iodo/uso terapêutico , Coativadores de Receptor Nuclear/genética , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Proteínas Proto-Oncogênicas c-ret/genética , Câncer Papilífero da Tireoide/tratamento farmacológico , Câncer Papilífero da Tireoide/genética , Neoplasias da Glândula Tireoide/tratamento farmacológico , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/patologia , Fatores de Transcrição/genética
3.
Diabetes Res Clin Pract ; 203: 110876, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37595843

RESUMO

AIMS: To examine the impact of pregnancy on microvascular and cardiovascular measures in women with youth-onset T2D. METHODS: Microvascular and cardiovascular measures were compared in in a cohort of 116 women who experienced a pregnancy of ≥ 20 weeks gestation and 291 women who did not among women in the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study. RESULTS: Cox regression models adjusted for participant characteristics at baseline including age, race/ethnicity, household income, diabetes duration, HbA1c (>6%), and BMI, demonstrated those who experienced pregnancy had 2.76 (1.38-5.49; p = 0.004) fold increased risk of hyperfiltration (eGFR ≥ 135 ml/min/1.73 m2), compared to those without a pregnancy. No differences were observed in rates of retinopathy (48.9% vs. 41.1%) or neuropathy (23.3% vs. 16.3%) in women who experienced pregnancy vs. women who did not, respectively. In fully adjusted models, pregnancy did not impact changes in echocardiographic or arterial stiffness compared to changes in women who were never pregnant. CONCLUSIONS: These results indicate that pregnancy increases the risk of hyperfiltration in women with youth-onset T2D, but not other micro or macrovascular complications. The rates of vascular complications are very high in youth-onset T2D potentially obscuring micro- and macrovascular changes attributable to pregnancy. CLINICAL TRIAL INFORMATION: ClinicalTrials.gov numbers,NCT01364350andNCT02310724.


Assuntos
Doenças Cardiovasculares , Diabetes Mellitus Tipo 2 , Adolescente , Feminino , Humanos , Gravidez , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/complicações , Diabetes Mellitus Tipo 2/complicações , Coração , Fatores de Risco
4.
Nat Commun ; 14(1): 3278, 2023 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-37311757

RESUMO

Environmental factors may alter the fetal genome to cause metabolic diseases. It is unknown whether embryonic immune cell programming impacts the risk of type 2 diabetes in later life. We demonstrate that transplantation of fetal hematopoietic stem cells (HSCs) made vitamin D deficient in utero induce diabetes in vitamin D-sufficient mice. Vitamin D deficiency epigenetically suppresses Jarid2 expression and activates the Mef2/PGC1a pathway in HSCs, which persists in recipient bone marrow, resulting in adipose macrophage infiltration. These macrophages secrete miR106-5p, which promotes adipose insulin resistance by repressing PIK3 catalytic and regulatory subunits and down-regulating AKT signaling. Vitamin D-deficient monocytes from human cord blood have comparable Jarid2/Mef2/PGC1a expression changes and secrete miR-106b-5p, causing adipocyte insulin resistance. These findings suggest that vitamin D deficiency during development has epigenetic consequences impacting the systemic metabolic milieu.


Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , MicroRNAs , Deficiência de Vitamina D , Humanos , Animais , Camundongos , Diabetes Mellitus Tipo 2/genética , Células-Tronco Hematopoéticas , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/genética , Vitamina D
5.
Pediatrics ; 150(6)2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36373280

RESUMO

BACKGROUND: The childhood obesity epidemic has grown exponentially and is known to disproportionately affect minority groups. Successful treatment of this complex health issue requires a multidisciplinary approach including metabolic and bariatric surgery (MBS) for qualifying pediatric patients. This study examines current national trends in pediatric bariatric surgery from 2010 to 2017 using the National Inpatient Sample. METHODS: This study analyzed MBS among pediatric patients <19 years old using weighted discharge data from 2010 to 2017. The primary outcome was national procedure rates. Secondary analyses included procedure type, demographics, BMI, comorbidities, length of stay, and complication rates. RESULTS: From 2010 to 2017, annual bariatric procedure rates increased from 2.29 to 4.62 per 100 000 (P < .001). Laparoscopic sleeve gastrectomy outpaced Roux-en-Y gastric bypass and laparoscopic adjustable gastric band over time (0.31-3.99 per 100 000, P < .0001). The mean age was stable over time 18.10-17.96 (P = .78). The cohort was primarily female (76.5% to 75.4%), white (54.0% to 45.0%), and privately-insured (59.9% to 53.4%). Preoperative BMI increased from 2010 to 2017 (P < .001), whereas number of obesity-related comorbidities was stable (P > .05). Length of stay was <2 days (2.02-1.75, P = .04) and in-hospital complication rates were low (7.2% to 6.45%, P = .88). CONCLUSIONS: Pediatric MBS is underutilized nationally with disproportionately lower rates among minority groups. Despite incremental progress, further investigation into the racial and social determinants that limit access to pediatric weight loss surgery is critical.


Assuntos
Cirurgia Bariátrica , Derivação Gástrica , Laparoscopia , Obesidade Mórbida , Obesidade Infantil , Humanos , Criança , Feminino , Adulto Jovem , Adulto , Obesidade Mórbida/epidemiologia , Obesidade Mórbida/cirurgia , Obesidade Mórbida/complicações , Redução de Peso , Obesidade Infantil/epidemiologia , Obesidade Infantil/cirurgia , Obesidade Infantil/complicações , Cirurgia Bariátrica/efeitos adversos , Cirurgia Bariátrica/métodos , Derivação Gástrica/métodos , Resultado do Tratamento , Estudos Retrospectivos
6.
J Clin Endocrinol Metab ; 103(6): 2309-2318, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29697830

RESUMO

Context: Little is known about reproductive function in girls with youth-onset type 2 diabetes. Objectives: To characterize girls with irregular menses and effects of glycemic treatments on menses and sex steroids in the Treatment Options for Type 2 Diabetes in Youth (TODAY) study. Design: Differences in demographic, metabolic, and hormonal characteristics between regular- vs irregular-menses groups were tested; treatment group (metformin with or without rosiglitazone, metformin plus lifestyle) effect on menses and sex steroids over time in the study was assessed. This is a secondary analysis of TODAY data. Setting: Multicenter study in an academic setting. Patients: TODAY girls not receiving hormonal contraception and those at least 1-year postmenarche were included. Irregular menses was defined as three or fewer periods in the prior 6 months. Results: Of eligible participants with serum measurement of sex steroids (n = 190; mean age, 14 years), 21% had irregular menses. Those with irregular vs regular menses had higher body mass index (BMI) (P = 0.001), aspartate aminotransferase (AST) (P = 0.001), free androgen index (P = 0.0003), and total testosterone (P = 0.01) and lower sex hormone-binding globulin (SHBG) (P = 0.004) and estradiol (P = 0.01). Differences remained after adjustment for BMI. There was no treatment group effect on menses or sex steroids at 12 or 24 months, and no association of sex steroids was seen with measures of insulin sensitivity or secretion. Conclusions: Menstrual dysfunction is common in girls with recently diagnosed type 2 diabetes and associated with alterations in sex steroids, SHBG, and AST but not with alteration in insulin sensitivity or ß-cell function and did not improve with 2 years of antihyperglycemic treatment.


Assuntos
Diabetes Mellitus Tipo 2/complicações , Resistência à Insulina/fisiologia , Distúrbios Menstruais/complicações , Adolescente , Androgênios/sangue , Aspartato Aminotransferases/sangue , Índice de Massa Corporal , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Quimioterapia Combinada , Estradiol/sangue , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Hipoglicemiantes/uso terapêutico , Estilo de Vida , Distúrbios Menstruais/sangue , Metformina/uso terapêutico , Rosiglitazona/uso terapêutico , Globulina de Ligação a Hormônio Sexual/metabolismo , Testosterona/sangue
7.
PLoS One ; 8(1): e54625, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23349943

RESUMO

Multiple epidemiological studies link vitamin D deficiency to increased cardiovascular disease (CVD), but causality and possible mechanisms underlying these associations are not established. To clarify the role of vitamin D-deficiency in CVD in vivo, we generated mouse models of diet-induced vitamin D deficiency in two backgrounds (LDL receptor- and ApoE-null mice) that resemble humans with diet-induced hypertension and atherosclerosis. Mice were fed vitamin D-deficient or -sufficient chow for 6 weeks and then switched to high fat (HF) vitamin D-deficient or -sufficient diet for 8-10 weeks. Mice with diet-induced vitamin D deficiency showed increased systolic and diastolic blood pressure, high plasma renin, and decreased urinary sodium excretion. Hypertension was reversed and renin was suppressed by returning chow-fed vitamin D-deficient mice to vitamin D-sufficient chow diet for 6 weeks. On a HF diet, vitamin D-deficient mice had ~2-fold greater atherosclerosis in the aortic arch and ~2-8-fold greater atherosclerosis in the thoracic and abdominal aorta compared to vitamin D-sufficient mice. In the aortic root, HF-fed vitamin D-deficient mice had increased macrophage infiltration with increased fat accumulation and endoplasmic reticulum (ER) stress activation, but a lower prevalence of the M1 macrophage phenotype within atherosclerotic plaques. Similarly, peritoneal macrophages from vitamin D-deficient mice displayed an M2-predominant phenotype with increased foam cell formation and ER stress. Treatment of vitamin D-deficient mice with the ER stress reliever PBA during HF feeding suppressed atherosclerosis, decreased peritoneal macrophage foam cell formation, and downregulated ER stress proteins without changing blood pressure. Thus, we suggest that vitamin D deficiency activates both the renin angiotensin system and macrophage ER stress to contribute to the development of hypertension and accelerated atherosclerosis, highlighting vitamin D replacement as a potential therapy to reduce blood pressure and atherosclerosis.


Assuntos
Aterosclerose/metabolismo , Hipertensão/metabolismo , Deficiência de Vitamina D/metabolismo , Vitamina D/metabolismo , Animais , Aorta Abdominal/metabolismo , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Aterosclerose/complicações , Aterosclerose/fisiopatologia , Dieta Hiperlipídica , Estresse do Retículo Endoplasmático , Humanos , Hipertensão/complicações , Hipertensão/fisiopatologia , Macrófagos/metabolismo , Camundongos , Camundongos Knockout , Receptores de LDL/genética , Receptores de LDL/metabolismo , Vitamina D/administração & dosagem , Vitamina D/genética , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/fisiopatologia
8.
J Biol Chem ; 287(46): 38482-94, 2012 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-23012375

RESUMO

Cardiovascular disease is the leading cause of morbidity/mortality in patients with type 2 diabetes mellitus (T2DM), but there is a lack of knowledge about the mechanism(s) of increased atherosclerosis in these patients. In patients with T2DM, the prevalence of 25-hydroxy vitamin D (25(OH)D) deficiency is almost twice that for nondiabetics and doubles the relative risk of developing cardiovascular disease compared with diabetic patients with normal 25(OH)D. We tested the hypothesis that monocytes from vitamin D-deficient subjects will have a proatherogenic phenotype compared with vitamin D-sufficient subjects in 43 patients with T2DM. Serum 25(OH)D level inversely correlated with monocyte adhesion to endothelial cells even after adjustment for demographic and comorbidity characteristics. Vitamin D-sufficient patients (≥30 ng/ml 25(OH)D) had lower monocyte endoplasmic reticulum (ER) stress, a predominance of M1 over M2 macrophage membrane receptors, and decreased mRNA expression of monocyte adhesion molecules PSGL-1, ß(1)-integrin, and ß(2)-integrin compared with patients with 25(OH)D levels of <30 ng/ml. In vitamin D-deficient macrophages, activation of ER stress increased adhesion and adhesion molecule expression and induced an M2-predominant phenotype. Moreover, adding 1,25(OH)(2)D(3) to vitamin D-deficient macrophages shifted their phenotype toward an M1-predominant phenotype with suppressed adhesion. Conversely, deletion of the vitamin D receptor in macrophages from diabetic patients activated ER stress, accelerated adhesion, and increased adhesion molecule expression. The absence of ER stress protein CCAAT enhancer-binding protein homologous protein suppressed monocyte adhesion, adhesion molecule expression, and the M2-predominant phenotype induced by vitamin D deficiency. Thus, vitamin D is a natural ER stress reliever that induced an antiatherogenic monocyte/macrophage phenotype.


Assuntos
Aterosclerose/patologia , Diabetes Mellitus Tipo 2/metabolismo , Retículo Endoplasmático/metabolismo , Macrófagos/citologia , Monócitos/citologia , Vitamina D/metabolismo , Adulto , Idoso , Antígenos CD18/biossíntese , Adesão Celular , Diferenciação Celular , Estudos Transversais , Feminino , Humanos , Integrina beta1/biossíntese , Masculino , Glicoproteínas de Membrana/biossíntese , Pessoa de Meia-Idade , Fenótipo , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo
9.
J Nucl Med ; 50(11): 1873-80, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19875645

RESUMO

UNLABELLED: This article describes the evaluation of the radiopharmaceutical (64)Cu-CB-TE2A-c(RGDyK) ((64)Cu-RGD) as an imaging agent for osteolytic bone metastases and their associated inflammation by targeting of the alpha(v)beta(3) integrin on osteoclasts and the proinflammatory cells involved at the bone metastatic site. METHODS: The (64)Cu-RGD radiotracer was evaluated in the transgenic mouse expressing Tax (Tax(+)), which spontaneously develops osteolytic tumors throughout the vertebrae and hind limbs, using biodistribution studies and small-animal PET/CT. Histologic analysis was also performed on Tax(+) mouse tails, using hematoxylin and eosin and tartrate-resistant acid phosphatase to confirm the presence of osteolytic bone lesions and the presence of osteoclasts, respectively. Additionally, a proof-of-principle study was conducted with a small group of Tax(+) animals presenting with osteolytic lesions. These animals were treated with the bisphosphonate zoledronic acid and imaged with (64)Cu-RGD to determine whether this radiopharmaceutical was sensitive enough to detect a response to the bisphosphonate therapy. RESULTS: Biodistribution studies using (64)Cu-RGD demonstrated that Tax(+) mice between the ages of 6 and 12 mo had a greater accumulation of activity in their tail vertebrae than did the wild-type (WT) cohort (P = 0.013). Additionally, Tax(+) mice between the ages of 6 and 12 mo had significantly more tracer activity associated with their tail vertebrae than did Tax(+) mice older than 12 mo (P = 0.003), suggesting that earlier bone metastases cause an increased recruitment of alpha(v)beta(3)-expressing cells. Small-animal PET/CT with (64)Cu-RGD was conducted on Tax(+) and WT mice. On the basis of standardized uptake value analysis, Tax(+) mice had approximately 2-fold more tail-associated activity than did WT animals (P = 0.0157). Additionally, decreases in uptake were observed in the tails of Tax(+) mice after treatment with the osteoclast inhibitor zoledronic acid, and histologic analysis of Tax(+) mouse-tail vertebrae revealed the presence of Tax(+) tumor cells, osteoclasts, and proinflammatory cells within the bone microenvironment. CONCLUSION: Together, these data suggest that (64)Cu-RGD has the potential to effectively image osteolytic bone metastases and monitor the physiologic changes in the bone metastatic microenvironment after osteoclast-inhibiting bisphosphonate therapy.


Assuntos
Neoplasias Ósseas/diagnóstico , Neoplasias Ósseas/secundário , Osteólise/complicações , Osteólise/diagnóstico , Receptores de Vitronectina/metabolismo , Animais , Neoplasias Ósseas/complicações , Neoplasias Ósseas/metabolismo , Radioisótopos de Cobre/química , Diagnóstico Diferencial , Difosfonatos/uso terapêutico , Regulação Neoplásica da Expressão Gênica , Produtos do Gene tax/metabolismo , Humanos , Leucemia de Células T/diagnóstico , Camundongos , Mieloma Múltiplo/diagnóstico , Oligopeptídeos/química , Oligopeptídeos/metabolismo , Osteoclastos/patologia , Osteólise/metabolismo , Osteólise/patologia , Tomografia por Emissão de Pósitrons , Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/metabolismo , Cauda , Tomografia Computadorizada por Raios X , Resultado do Tratamento
10.
J Nucl Med ; 48(2): 311-8, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17268030

RESUMO

UNLABELLED: Bone diseases are often a result of increased numbers of osteoclasts, or bone-resorbing cells. Bone metastases are a significant cause of morbidity in many types of cancer. An imaging agent targeting osteoclasts, which are upregulated in osteolytic lesions, may facilitate earlier follow-up in patients with osteolytic or mixed bone metastases. Osteoclasts express high levels of alpha(v)beta3 integrin, to which peptides containing the Arg-Gly-Asp (RGD) sequence are known to bind. We proposed that radiolabeled RGD peptides could be used to detect osteoclasts in lytic bone lesions. METHODS: The cross-bridged macrocyclic chelator 4,11-bis(carboxymethyl)-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane (CB-TE2A) was conjugated to c(RGDyK) for radiolabeling with 64Cu (t(1/2), 12.7 h; beta+, 17.4%; E(beta+ max), 656 keV; beta-, 39%; E(beta- max), 573 keV). The in vitro affinity of Cu(II)-CB-TE2A-c(RGDyK) for alpha(v)beta3 and alpha(v)beta5 was evaluated in a heterologous competitive binding assay. Ex vivo uptake was examined in osteoclasts prepared from bone marrow macrophages. As a proof of principle, biodistribution and imaging studies were performed on parathyroid hormone (PTH)-induced osteolysis in the calvarium. RESULTS: Cu-CB-TE2A-c(RGDyK) was shown to have a 30-fold higher affinity for alpha(v)beta3 than for alpha(v)beta5. Osteoclasts were shown to specifically take up (64)Cu-CB-TE2A-c(RGDyK). However, bone marrow macrophages showed only nonspecific uptake. PTH treatment increased calvarial uptake of 64Cu-CB-TE2A-c(RGDyK), compared with uptake in mice receiving a sham treatment. In addition, calvarial uptake correlated linearly with the number of osteoclasts on the bone surface. CONCLUSION: These results suggest that 64Cu-CB-TE2A-c(RGDyK) selectively binds alpha(v)beta3 on osteoclasts and may potentially be used to identify increased numbers of osteoclasts in osteolytic bone diseases such as osteolytic bone metastasis and inflammatory osteolysis.


Assuntos
Oligopeptídeos , Osteoclastos/diagnóstico por imagem , Osteólise/induzido quimicamente , Osteólise/diagnóstico por imagem , Hormônio Paratireóideo , Compostos Radiofarmacêuticos , Animais , Biotina , Western Blotting , Células da Medula Óssea/metabolismo , Radioisótopos de Cobre , Meia-Vida , Integrinas/metabolismo , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Tomografia por Emissão de Pósitrons , Distribuição Tecidual , Vitronectina
11.
Nucl Med Biol ; 33(2): 227-37, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16546677

RESUMO

INTRODUCTION: Overexpression of matrix metalloproteinases (MMPs), particularly MMP-2 and MMP-9, has been correlated with poor prognosis in several cancer types including lung, colon and breast. Noninvasive detection of MMP expression might allow physicians to better determine when more aggressive cancer therapy is appropriate. The peptide CTT (CTTHWGFTLC) was identified as a selective inhibitor of MMP-2/9 that inhibits the growth of MDA-MB-435 human breast cancer xenografts. METHODS: CTT was conjugated with the bifunctional chelator DOTA (1,4,7,10-tetraazacyclotetradecane-N,N',N'',N'''-tetraacetic acid) for radiolabeling with (64)Cu (t(1/2)=12.7 h, 17.4% beta(+), 39% beta(-)), a radionuclide suitable for positron emission tomography (PET). In vitro affinity was determined in a fluorogenic substrate assay. Tumor gelatinase targeting was evaluated in both biodistribution and microPET imaging studies. RESULTS: Cu(II)-DOTA-CTT inhibited hMMP-2 (EC(50)=8.7 microM) and mMMP-9 (EC(50)=18.2 microM) with similar affinity to CTT (hMMP-2 EC(50)=13.2 microM; mMMP-9 EC(50)=11.0 microM). In biodistribution and microPET imaging studies, (64)Cu-DOTA-CTT was taken up by MMP-2/9-positive B16F10 murine melanoma tumors. Subsequently, imaging studies using (64)Cu-DOTA-CTT were performed on MDA-MB-435 tumor-bearing mice. With zymography, tumor MMP-2/9 expression in this model was shown to be inconsistent, resulting in microPET detection of the MDA-MB-435 tumor in only 1 of 24 imaged mice. Following limited imaging success, (64)Cu-DOTA-CTT was shown to have poor in vivo stability. CONCLUSIONS: Despite some evidence for selective uptake of (64)Cu-DOTA-CTT by gelatinase-expressing tumors, the low affinity for MMP-2 and MMP-9 and in vivo instability make this an inadequate radioligand for in vivo tumor evaluation.


Assuntos
Biomarcadores Tumorais/metabolismo , Modelos Animais de Doenças , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Melanoma/metabolismo , Melanoma/secundário , Oligopeptídeos/fisiologia , Animais , Linhagem Celular Tumoral , Masculino , Melanoma/diagnóstico por imagem , Taxa de Depuração Metabólica , Camundongos , Camundongos Endogâmicos C57BL , Compostos Organometálicos , Cintilografia , Compostos Radiofarmacêuticos/farmacocinética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
12.
Clin Cancer Res ; 10(24): 8674-82, 2004 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-15623652

RESUMO

PURPOSE: Somatostatin receptors (SSTr) are expressed on many neuroendocrine tumors, and several radiotracers have been developed for imaging these types of tumors. For this reason, peptide analogues of somatostatin have been well characterized. Copper-64 (t(1/2) = 12.7 hours), a positron emitter suitable for positron emission tomography (PET) imaging, was shown recently to have improved in vivo clearance properties when chelated by the cross-bridged tetraazamacrocycle 4,11-bis(carboxymethyl)-1,4,8,11-tetraazabicyclo(6.6.2)hexadecane (CB-TE2A) compared with 1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid (TETA). EXPERIMENTAL DESIGN: CB-TE2A and TETA were conjugated to the somatostatin analogue tyrosine-3-octreotate (Y3-TATE) for evaluation of CB-TE2A as a bifunctional chelator of 64Cu. The in vitro affinity of each compound for SSTr was determined using a homologous competitive binding assay. In vivo characteristics of both radiolabeled compounds were examined in biodistribution and microPET studies of AR42J tumor-bearing rats. RESULTS: Cu-CB-TE2A-Y3-TATE (Kd = 1.7 nmol/L) and Cu-TETA-Y3-TATE (Kd = 0.7 nmol/L) showed similar affinities for AR42J derived SSTr. In biodistribution studies, nonspecific uptake in blood and liver was lower for 64Cu-CB-TE2A-Y3-TATE. Differences increased with time such that, at 4 hours, blood uptake was 4.3-fold higher and liver uptake was 2.4-fold higher for 64Cu-TETA-Y3-TATE than for 64Cu-CB-TE2A-Y3-TATE. In addition, 4.4-times greater tumor uptake was detected with 64Cu-CB-TE2A-Y3-TATE than with 64Cu-TETA-Y3-TATE at 4 hours postinjection. MicroPET imaging yielded similar results. CONCLUSIONS: CB-TE2A appears to be a superior in vivo bifunctional chelator of 64Cu for use in molecular imaging by PET or targeted radiotherapy due to both improved nontarget organ clearance and higher target organ uptake of 64Cu-CB-TE2A-Y3-TATE compared with 64Cu-TETA-Y3-TATE.


Assuntos
Quelantes , Radioisótopos de Cobre , Compostos Organometálicos/síntese química , Neoplasias Pancreáticas/tratamento farmacológico , Compostos Radiofarmacêuticos/síntese química , Animais , Ligação Competitiva , Quelantes/química , Quelantes/metabolismo , Cobre/química , Cobre/metabolismo , Técnicas In Vitro , Compostos Organometálicos/química , Compostos Organometálicos/farmacocinética , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/metabolismo , Compostos Radiofarmacêuticos/química , Compostos Radiofarmacêuticos/farmacocinética , Ratos , Ratos Endogâmicos Lew , Relação Estrutura-Atividade , Distribuição Tecidual , Tomografia Computadorizada de Emissão , Células Tumorais Cultivadas
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