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1.  In vivo gene therapy for hyperlipidemia: phenotypic correction in Watanabe rabbits by hepatic delivery of the rabbit LDL receptor gene. 
Journal of Clinical Investigation  1995;95(2):768-773.
Elevations of plasma total or LDL cholesterol are major risk factors for cardiovascular disease. Efforts directed at preventing and treating cardiovascular disease have often focused on reducing the levels of these substances in the blood. The Watanabe Heritable Hyperlipidemic Rabbit, which has exceedingly high plasma cholesterol levels resulting from an LDL receptor deficiency, provides an excellent animal model for testing new treatments. A recombinant adenoviral vector containing the rabbit LDL receptor cDNA was administered to Watanabe rabbits. Plasma total cholesterol levels in the treated animals were reduced from 825.5 +/- 69.8 (mean +/- SD) to 247.3 +/- 61.5 mg/dl 6 d after infusion. These animals also demonstrated a 300-400% increase in plasma levels of HDL cholesterol and apo AI 10 d after treatment. As a result, the LDL:HDL ratio exhibited a dramatic decrease. Because only the rabbit LDL receptor gene was used for treatment, the results strongly suggest that the elevations of plasma HDL cholesterol and apo AI were secondary to a reduction in plasma total cholesterol in the treated animals. These results suggest an inverse relationship between plasma LDL and HDL cholesterol levels and imply that reduction of LDL cholesterol levels may have a beneficial effect on plasma HDL cholesterol.
PMCID: PMC295550  PMID: 7860759
2.  Preeclampsia is associated with abnormal expression of adhesion molecules by invasive cytotrophoblasts. 
Journal of Clinical Investigation  1993;91(3):950-960.
In normal human pregnancy, invasion of the uterus and its arterial system by cytotrophoblasts extends through the entire decidua and the adjacent third of the myometrium. Our previous work showed that during the first trimester of pregnancy, invasion is accompanied by a marked change in the expression of cell adhesion molecules by invasive cytotrophoblasts. In the pregnancy disorder preeclampsia, cytotrophoblast invasion is limited to the superficial decidua, and few arterioles are breached. The purpose of this study was to determine whether cytotrophoblast expression of adhesion molecules in this disorder is also abnormal. Placental bed biopsy specimens from normal pregnancies and those complicated by preeclampsia were stained with anti-integrin antibodies. The results showed that adhesion molecule switching by invasive cytotrophoblasts is abnormal in preeclampsia, which suggests that this subpopulation of trophoblast cells fails to differentiate properly. A likely result is that the delicate balance of adhesive interactions that normally permit cytotrophoblast invasion is tipped in favor of those which restrain this process, with the net effect of shallow uterine invasion.
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PMCID: PMC288047  PMID: 7680671
3.  Epitope mapping of the von Willebrand factor subunit distinguishes fragments present in normal and type IIA von Willebrand disease from those generated by plasmin. 
Journal of Clinical Investigation  1987;79(2):524-531.
A small but consistent proportion of the von Willebrand factor (vWF) in normal plasma is composed of 189, 176, and 140 kD fragments cleaved from the 225 kD subunit. A monoclonal antibody map of vWF, based on the reactivity of individual antibodies with cyanogen bromide and tryptic fragments of known carboxy and/or amino termini, showed that in normal and IIA von Willebrand disease (vWD) plasmas the 140 kD fragment was derived from the amino-terminal region, whereas the 176 kD fragment was derived from the carboxy-terminal region of the subunit. In type IIA vWD, however, the fragments comprised a greater proportion of circulating vWF. In contrast, plasmin cleaved a 176 kD fragment from the amino terminus and a 145 kD fragment from the carboxy terminus of the subunit. Species similar to these plasmin-cleaved fragments were demonstrated in plasmas from four patients treated with fibrinolytic agents, but not in IIA vWD.
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PMCID: PMC424117  PMID: 2433308
4.  Independent modulation of von Willebrand factor and fibrinogen binding to the platelet membrane glycoprotein IIb/IIIa complex as demonstrated by monoclonal antibody. 
Journal of Clinical Investigation  1985;76(5):1950-1958.
In this study we have used two new monoclonal antibodies, designated LJP5 and LJP9, as well as a previously described one, AP2, all specific for the platelet membrane glycoprotein (GP)IIb/IIIa complex. None of them reacted with dissociated GPIIb or GPIIIa. The monovalent Fab fragment of both LJP5 and LJP9 bound to unstimulated platelets in a saturable manner, but binding was markedly decreased after platelets had been incubated at 37 degrees C in the absence of added extracellular calcium. The binding of LJP9 was not affected by AP2, but was blocked by excess LJP5. On the contrary, the binding of LJP5 was blocked in the presence of both AP2 and LJP9. Thus, these antibodies bound to distinct epitopes of GPIIb/IIIa. At saturation, the binding to unstimulated platelets was between 2.41 and 10.9 X 10(4) molecules/platelet for LJP5 and between 3.47 and 9.1 X 10(4) molecules/platelet for LJP9 (range of 11 and 10 experiments, respectively). Binding increased up to 50% after thrombin stimulation. The estimated association constant, Ka, was 2.7 X 10(7) M-1 for LJP5 and 3.85 X 10(7) M-1 for LJP9. Both LJP5 and LJP9 partially inhibited the association of 45Ca2+ with the surface of unstimulated platelets. Moreover, both antibodies blocked the binding of von Willebrand factor (vWF) to stimulated platelets, whereas only LJP9, but not LJP5, blocked fibrinogen binding. LJP9 was also a potent inhibitor of platelet aggregation, whereas LJP5 was without effect in this regard. The results of the present study demonstrate that independent modulation of vWF and fibrinogen binding to stimulated platelets can be attained with monoclonal antibodies directed against distinct epitopes of GPIIb/IIIa.
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PMCID: PMC424250  PMID: 2414325
5.  Characterization of human platelet vasopressin receptors. 
Journal of Clinical Investigation  1985;76(5):1857-1864.
Using tritiated arginine-8-vasopressin [3H]AVP, vasopressin-specific binding sites were detected on human platelet membranes. One class of high-affinity binding sites was characterized with an equilibrium dissociation constant of 1.01 +/- 0.06 nM and a maximal binding capacity of 100 +/- 10 fmol/mg of protein (n = 12). Highly significant correlations were found between the relative agonistic (r = 0.87, P = 0.002) or antagonistic (r = 0.99, P = 0.007) vasopressor activities of a series of 13 AVP structural analogues and their relative abilities to inhibit [3H]AVP binding to platelet receptors whereas no such relationship existed when antidiuretic activities were considered (r = 0.28, P = 0.47). AVP did not stimulate cyclic AMP production of human platelets; on the contrary, high AVP concentrations (10(-6) M) inhibited cyclic AMP production measured in basal and prostaglandin E1-stimulated conditions. AVP caused intact platelet aggregation with a half-maximal aggregation (EC50) of 28 +/- 2 nM. This effect was more potently reversed by the specific vascular antagonist d(CH2)5Tyr(Me)AVP (pA2 = 8.10 +/- 0.23) than by the specific renal antagonist d(CH2)5IleuAlaAVP (pA2 = 6.67 +/- 0.12). The pA2 values of these two antagonists in platelets are in close agreement with the pKi values obtained in competition experiments (respectively 8.59 and 6.93) and with pA2 values reported in the literature for their in vivo antivasopressor activity (respectively 8.62 and 6.03). The observation that human platelets bear AVP receptors belonging to the vascular class suggests that platelet receptors can be used to further explore the role of vasopressin in cardiovascular homeostasis.
PMCID: PMC424226  PMID: 2997293
6.  Human factor VIII procoagulant protein. Monoclonal antibodies define precursor-product relationships and functional epitopes. 
Journal of Clinical Investigation  1985;76(1):117-124.
The human Factor VIII procoagulant protein (VIII:C) purified from commercial Factor VIII concentrate consisted of a polypeptide doublet of 80,000 mol wt, a 92,000-mol wt polypeptide, and additional polypeptides of up to 188,000 mol wt. Thrombin digests contained a doublet of 72,000 mol wt, as well as 54,000- and 44,000-mol wt fragments. Proteolysis studies of purified VIII:C using thrombin and activated protein C have suggested that the 92,000- and 80,000 (or 72,000)-mol wt polypeptides comprise activated VIII:C. We have now used seven monoclonal antibodies raised against purified VIII:C to construct a preliminary epitope map of these VIII:C polypeptides. The specific VIII:C polypeptides with which the monoclonal antibodies reacted were determined by immunoblotting of VIII:C onto nitrocellulose sheets after reduced NaDodSO4-polyacrylamide gel electrophoresis. A minimum of five distinct epitopes were defined by these monoclonal anti-VIII:C antibodies. Identification of polypeptides bearing these epitopes allowed localization of distinct thrombin cleavage sites to the 92,000- and 80,000-mol wt chains, helped define polypeptide chain precursor-product relationships, and suggested that both the 92,000- and 80,000-mol wt polypeptides are necessary for VIII:C function. These data and their interpretation are consistent with the published description of the complete primary structure of VIII:C and its thrombin cleavage products. The 92,000- and 80,000-mol wt chains have been located at the amino- and carboxy-terminal ends of the molecule, respectively.
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PMCID: PMC423722  PMID: 2410456

Results 1-7 (7)