Background—
It is unclear what is the most efficient vector and growth factor for induction of therapeutic vascular growth in the heart. Furthermore, the histological nature of angiogenesis and potential side effects caused by different vascular endothelial growth factors (VEGFs) in myocardium have not been documented.
Methods and Results—
Adenoviruses (Ad) at 2 doses (2×10
11
and 2×10
12
viral particles) or naked plasmids (1 mg) encoding
Lac
Z control, VEGF-A
165
, or the mature, soluble form of VEGF-D (VEGF-D
ΔNΔC
) were injected intramyocardially with the NOGA catheter system into domestic pigs. AdVEGF-D
ΔNΔC
gene transfer (GT) induced a dose-dependent myocardial protein production, as measured by ELISA, resulting in an efficient angiogenic effect 6 days after the injections. Also, AdVEGF-A
165
produced high gene transfer efficacy, as demonstrated with immunohistochemistry, leading to prominent angiogenesis effects. Despite the catheter-mediated approach, angiogenesis induced by both AdVEGFs was transmural, with maximal effects in the epicardium. Histologically, strongly enlarged α-smooth muscle actin–positive microvessels involving abundant cell proliferation were found in the transduced regions, whereas microvessel density did not change. Myocardial contrast echocardiography and microspheres showed marked increases in perfusion in the transduced areas. VEGF-D
ΔNΔC
but not matrix-bound VEGF-A
165
was detected in plasma after adenoviral GT. A modified Miles assay demonstrated myocardial edema resulting in pericardial effusion with the higher AdVEGF doses. All effects returned to baseline by 3 weeks. Naked plasmid–mediated GT did not induce detectable protein production or vascular effects.
Conclusions—
Like AdVEGF-A
165
, AdVEGF-D
ΔNΔC
GT using the NOGA system produces efficient transmural angiogenesis and increases myocardial perfusion. AdVEGF-D
ΔNΔC
could be useful for the induction of therapeutic vascular growth in the heart.
Background—
For clinically relevant proangiogenic therapy, it would be essential that the growth of the whole vascular tree is promoted. Vascular endothelial growth factor (VEGF) is well known to induce angiogenesis, but its capability to promote growth of larger vessels is controversial. We hypothesized that blood flow remodels vascular growth during VEGF gene therapy and may contribute to the growth of large vessels.
Methods and Results—
Adenoviral (Ad) VEGF or LacZ control gene transfer was performed in rabbit hindlimb semimembranous muscles with or without ligation of the profound femoral artery (PFA). Contrast-enhanced ultrasound and dynamic susceptibility contrast MRI demonstrated dramatic 23- to 27-fold increases in perfusion index and a strong decrease in peripheral resistance 6 days after AdVEGF gene transfer in normal muscles. Enlargement by 20-fold, increased pericyte coverage, and decreased alkaline phosphatase and dipeptidyl peptidase IV activities suggested the transformation of capillaries toward an arterial phenotype. Increase in muscle perfusion was attenuated, and blood vessel growth was more variable, showing more sprouting angiogenesis and formation of blood lacunae after AdVEGF gene transfer in muscles with ligated PFA than in normal muscles. Three-dimensional ultrasound reconstructions and histology showed that the whole vascular tree, including large arteries and veins, was enlarged manifold by AdVEGF. Blood flow was normalized and enlarged collaterals persisted in operated limbs 14 days after AdVEGF treatment.
Conclusions—
This study shows that (1) blood flow modulates vessel growth during VEGF gene therapy and (2) VEGF overexpression promotes growth of arteries and veins and induces capillary arterialization leading to supraphysiological blood flow in target muscles.
After microbubble contrast agent injection, malignant and benign adnexal lesions behave differently in degree, onset, and duration of Doppler US enhancement.
Although overall survival is comparable with previous studies, our concern is procedure-related infections and preterm births. Close collaboration between the university hospitals is needed to ensure timely treatment, operator skills and systematic follow-up of the children.
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