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 64 Cu. 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 (K d ؍ 1.7 nmol/L) and Cu-TETA-Y3-TATE (K d ؍ 0.7 nmol/L) showed similar affinities for AR42J derived SSTr. In biodistribution studies, nonspecific uptake in blood and liver was lower for 64 Cu-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 64 Cu-TETA-Y3-TATE than for 64 Cu-CB-TE2A-Y3-TATE. In addition, 4.4-times greater tumor uptake was detected with 64 Cu-CB-TE2A-Y3-TATE than with 64 Cu-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 64 Cu for use in molecular imaging by PET or targeted radiotherapy due to both improved nontarget organ clearance and higher target organ uptake of 64 Cu-CB-TE2A-Y3-TATE compared with 64 Cu-TETA-Y3-TATE.
Background:Interactions between environmental conditions and monocyte phenotype are critical for the development of vascular complications in diabetes. Results: Modulation of ER stress by vitamin D controls monocyte/macrophage phenotype and vascular adhesion. Conclusion: Vitamin D is a natural ER stress reliever that promotes an anti-inflammatory monocyte/macrophage phenotype. Significance: Vitamin D is a potential therapy to reduce vascular complications in diabetics.
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.
Copper-64, a positron emitter suitable for positron emission tomography (PET), demonstrates improved in vivo clearance when chelated by the cross-bridged tetraazamacrocycle CB-TE2A compared to TETA. Good in vivo clearance was also observed for 64Cu-CB-TE2A conjugated to a peptide, which converts one coordinating carboxylate pendant arm to an amide. To better understand the in vivo stability of peptide- conjugated CB-TE2A, cross-bridged monoamides were synthesized. Crystal structures of natCu(II)-CB-TEAMA and natCu(II)-CB-PhTEAMA revealed hexadentate, distorted octahedral coordination geometry. In vivo biodistribution showed clearance of all 64Cu-radiolabeled cross-bridged monoamides from liver and bone marrow such that uptake at 24 h was <10% of uptake at 30 min. In contrast, >60% of 30 min uptake from 64Cu-TETA was retained in these tissues at 24 h. Clearance of 64Cu-cross-bridged monoamides from nontarget organs suggests good in vivo stability, thus supporting the use of CB-TE2A as a bifunctional chelator without modifications to the macrocycle backbone.
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 a v b 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 1 ), 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 1 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 1 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 1 mice between the ages of 6 and 12 mo had a greater accumulation of activity in their tail vertebrae than did the wildtype (WT) cohort (P 5 0.013). Additionally, Tax 1 mice between the ages of 6 and 12 mo had significantly more tracer activity associated with their tail vertebrae than did Tax 1 mice older than 12 mo (P 5 0.003), suggesting that earlier bone metastases cause an increased recruitment of a v b 3 -expressing cells. Small-animal PET/CT with 64 Cu-RGD was conducted on Tax 1 and WT mice. On the basis of standardized uptake value analysis, Tax 1 mice had approximately 2-fold more tail-associated activity than did WT animals (P 5 0.0157). Additionally, decreases in uptake were observed in the tails of Tax 1 mice after treatment with the osteoclast inhibitor zoledronic acid, and histologic analysis of Tax 1 mouse-tail vertebrae revealed the presence of Tax 1 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. Bone metastases are a debilitating form of metastases causing severe bone pain, hypercalcemia, and pathologic bone fracture, and in some cases paralysis. Although the number of Americans living with bone metastases is unknown, it is estimated that at least 25% of those who die of cancer have them at the time of death (1). Bone metastases are classified as either osteoblastic or osteolytic lesions. The former results from the stimulation and proliferation of osteoblasts and culminates in the formation of excess bone. Conversely, osteolytic lesions are caused by the vicious cycle of bidirectional interactions between tumor cells and osteoclasts. In this cycle, i...
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 β-cell function and did not improve with 2 years of antihyperglycemic treatment.
Repeat Fundus Exam (N=367) Sex (% Female) 452 (64.6%) 236 (64.3%) Race/ Ethnicity Hispanic 278 (39.7%) 146 (39.7%) Non-Hispanic Black 227 (32.5%) 126 (34.3%) Non-Hispanic White 143 (20.5%) 71 (19.3%) Other 51 (7.3%) 24 (6.5%) Age at baseline (years) 14.0 (± 2.0) 13.7 (± 2.0) Diabetes Duration (years) 4.9 (± 1.5) 4.9 (± 1.5) Mean BMI (kg/m 2 ) 34.9 (± 7.6) 34.7 (± 7.8) Mean HbA1c (%) 6.0 (± 0.7) 6.0 (± 0.8) Blood Pressure Mean Systolic BP (mm Hg) 113.2 (± 10.9) 112.6 (± 10.7) Mean Diastolic BP (mm Hg) 66.7 (± 8.2) 66.6 (± 8.1) Cholesterol Mean LDL (mg/dL) 85 (± 24.8) 84 (± 24.2) Mean HDL (mg/dL) 38.7 (± 8.6) 38.7 (± 8.8) Mean Triglycerides (mg/dL) 93.5 [27/0, 823.0] 89 [30.0, 623.0] Mean Fasting C-Peptide (ng/mL) 3.6 [0.9, 11.1] 3.5 [0.9, 9.6] Mean Fasting Glucose (mg/dL) 103.0 [70.0, 269.0] 103 [70.0, 210.0] Comorbidities (%) Hypertension 132 (18.8%) 69 (18.8%) ACR ≥30mg/g 54 (7.7%) 28 (7.6%) ACR ≥300mg/g 10 (1.4%) 7 (1.9%) Medications (%) History of any hypertensive medication 32 (4.6%) 22 (6.0%) History of any lipid lowering medication 6 (0.8%) 5 (1.4%) Ever Smoked (%) 27 (3.8%) 9 (2.5%) Data are mean (± std), median [IQR], or n (%).
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