Long term inhibition of neointima formation in balloon-injured rat arteries by intraluminal instillation of a matrix-targeted retroviral vector bearing a cytocidal mutant cyclin G1 construct.

Restenosis from neointimal proliferation is a frequent complication of intracoronary stenting and catheter-based revascularization procedures. Currently, there is no known therapeutic strategy that has been sufficiently effective to warrant its widespread use. In the present study, the anti-proliferative properties of a matrix (collagen)-targeted retroviral vector bearing a mutant cyclin G1 (DNT 41-249) construct was evaluated in vitro and in vivo. In controlled one-month efficacy studies, the intraluminal instillation of the mutant cyclin G1 vector significantly inhibited neointima lesion formation in balloon-injured rat arteries without neointimal growth, associated necrosis or intense inflammatory reaction. Taken together, these data extend the potential utility of the matrix-targeted mutant cyclin G1 retroviral vector for management of vascular restenosis.

Inhibition of metastatic tumor growth in nude mice by portal vein infusions of matrix-targeted retroviral vectors bearing a cytocidal cyclin G1 construct.

Tumor invasion and associated angiogenesis evoke a remodeling of extracellular matrix components. Retroviral vectors bearing auxiliary matrix-targeting motifs (ie., collagen-binding polypeptides) accumulate at sites of newly exposed collagen, thus promoting tumor site-specific gene delivery. In this study, we assessed the antitumor effects of serial portal vein infusions of matrix-targeted vectors bearing a mutant cyclin G1 (dnG1) construct in a nude mouse model of liver metastasis. The size of tumor foci was dramatically reduced in dnG1 vector-treated mice compared with that in control vector- or PBS-treated animals (P = 0.0002). These findings represent a definitive advance in the development of targeted injectable vectors for metastatic cancer.

Downregulation of cyclin G1 expression by retrovirus-mediated antisense gene transfer inhibits vascular smooth muscle cell proliferation and neointima formation.

BACKGROUND: The contemporary treatment of coronary athero-occlusive disease by percutaneous transluminal coronary angioplasty is hampered by maladaptive wound healing, resulting in significant failure rates. Morbid sequelae include smooth muscle cell (SMC) hyperplasia and restenosis due to vascular neointima formation. METHODS AND RESULTS: In this study, we examined the inhibitory effects of a concentrated retroviral vector bearing an antisense cyclin G1 gene on aortic SMC proliferation in vitro and on neointima formation in vivo in a rat carotid injury model of restenosis. Retroviral vectors bearing an antisense cyclin G1 construct inhibited the proliferation of transduced aortic SMCs in 2- to 6-day cultures, concomitant with down-regulation of cyclin G1 protein expression and decreased [3H]thymidine incorporation into DNA. Morphological examination showed evidence of cytolysis, giant syncytia formation, and apoptotic changes evidenced by overt cell shrinkage, nuclear fragmentation, and specific immunostaining of nascent 3'-OH DNA ends generated by endonuclease-mediated DNA fragmentation. Pronounced "bystander effects" including neighboring cells were noted in aortic SMCs transduced with the antisense cyclin G1 vector, as determined by quantitative assays and fluorescent labeling of nontransduced cells. In an in vitro tissue injury model, the proliferation and migration of antisense cyclin G1 vector-transduced aortic SMCs were inhibited. Moreover, in vivo delivery of high-titer antisense cyclin G1 vector supernatant to the balloon-injured rat carotid artery in vivo resulted in a significant reduction in neointima formation. CONCLUSIONS: These findings represent the first demonstration of the inhibitory effects of an antisense cyclin G1 retroviral vector on nonneoplastic cell proliferation. Taken together, these data affirm the potential utility of antisense cyclin G1 constructs in the development of novel gene therapy approaches to vascular restenosis.

[Determination of ionization constants of primaquine and study of its coordination ratio with vitamin C].

Primaquine (P) has long been used as an antimalarial drug. The following formulas are derived for determination of the ionization constants of PH3+3 by pH-titration method: Ka1 = [aH + (3 - a)Cp]/[(a - 2)Cp/aH - 1] Ka3 = [(1 - a)Cp aH - Kw]/(a Cp + Kw/aH) = (1/Ka2)[(2 - a)Cp a2H - Kw aH]/(Kw/aH + a Cp) + [(1 - a) Cp aH - Kw]/(Kw/aH + a Cp) in which Kw is the ionic product of water, a is the mole ratio of HClO4 to primaquine and Cp is the total concentration of primaquine. The ionization constants of primaquine in 50% (v/v) ethanol in water determined at 25 degrees C in the ionic strength range of 5 x 10(-3)-5 x 10(-2) mol/L are: Ka1 = (3.84 +/- 2.35) x 10(-2) (attributed to the secondary ammonium group of primaquine); Ka2 = (1.50 +/- 1.17) x 10(-8) (attributed to the tertiary ammonium group); Ka3 = (2.07 +/- 0.27) x 10(-10) (attributed to the primary ammonium group). The coordination ratio of primaquine to vitamin C in the above solvent is determined by continuous variation and mole ratio methods based on pH and conductance measurements to be 1:1, indicating that the coordination compound formed in the solution is mainly a 1:1 compound.

[Familial amyloid polyneuropathy: a clinical and biopsy report].

The first case of familial amyloid polyneuropathy (FAP) in China is reported and the literature reviewed. FAP is an autosomal dominant inherited disorder that primarily affects the peripheral and autonomic nervous systems. The exact onset of the disease begins so insidiously. Because of the confusion with other neurologic disease, the diagnosis is often delayed until advanced stage. In this case, sural musculus and sural nerve biopsy confirmed the presence of amyloid. Both the patient's grandfather and his (or her) father have the like history of the disease. Colchicine or Dimethyl-Sulphoxide (DMSO) treatment may prevent the development of FAP. The prognosis is poor. Most deaths result from heart or renal failure.

[Histochemical studies of three kinds of enzymes in dentinal caries].

Aminopeptidase, acid phosphatase and nonspecific esterase in dentinal caries were investigated by histochemical method in this study. It was found that in contrast with Gram's stain, the several hydrolytic enzymes were all located within the region where bacteria invaded the dentine. This suggested that the enzymes were produced by the bacteria invading dentinal tubules. According to previous study of the functions of these enzymes, it was speculated that in the process of dentinal caries, aminopeptidase and acid phosphatase may be involved in the decomposition of structural protein of dentinal organic matrix and non-specific esterase in the decomposition of structural lipids of dentine.