Sunny Zhang | Unb - Academia.edu (original) (raw)

Papers by Sunny Zhang

Research paper thumbnail of The Desire of Infertile Patients for Multiple Births

Obstetrical & Gynecological Survey, 2004

To determine the proportion of infertile women who prefer a multiple birth over a singleton, pati... more To determine the proportion of infertile women who prefer a multiple birth over a singleton, patient characteristics associated with this desire, and patient knowledge about the risks of multiple births. Design: Prospective analysis. Setting: Academic university hospital-based infertility center and private general gynecology clinic. Patient(s): Four hundred sixty-four female patients with infertility who presented for their initial visit. Main Outcome Measure(s): Demographic characteristics, infertility history, desire regarding multiple births, knowledge of the risks of multiple births, and goals of infertility evaluation and treatment were determined by using a 41-question survey. Univariate analysis was performed to assess patient characteristics associated with the desire for multiple births. Independent factors associated with this desire were assessed by multivariable logistic regression analysis. Result(s): 20.3% of women desired multiples over a singleton gestation. Nulliparity, lower family income, younger patient age, prior evaluation for infertility, longer duration of infertility, and lack of knowledge regarding risks of twin gestations were associated with this desire. Only nulliparity and lower family income were independently associated. Conclusion(s): A sizable minority of infertility patients prefers a multiple birth as their treatment outcome. Patient education may be an effective strategy to reduce the incidence of twin and higher-order multiple pregnancies. (Fertil Steril 2004;81:500 -4.

Research paper thumbnail of The desire of infertile patients for multiple births

Fertility and Sterility, 2004

To determine the proportion of infertile women who prefer a multiple birth over a singleton, pati... more To determine the proportion of infertile women who prefer a multiple birth over a singleton, patient characteristics associated with this desire, and patient knowledge about the risks of multiple births. Design: Prospective analysis. Setting: Academic university hospital-based infertility center and private general gynecology clinic. Patient(s): Four hundred sixty-four female patients with infertility who presented for their initial visit. Main Outcome Measure(s): Demographic characteristics, infertility history, desire regarding multiple births, knowledge of the risks of multiple births, and goals of infertility evaluation and treatment were determined by using a 41-question survey. Univariate analysis was performed to assess patient characteristics associated with the desire for multiple births. Independent factors associated with this desire were assessed by multivariable logistic regression analysis. Result(s): 20.3% of women desired multiples over a singleton gestation. Nulliparity, lower family income, younger patient age, prior evaluation for infertility, longer duration of infertility, and lack of knowledge regarding risks of twin gestations were associated with this desire. Only nulliparity and lower family income were independently associated. Conclusion(s): A sizable minority of infertility patients prefers a multiple birth as their treatment outcome. Patient education may be an effective strategy to reduce the incidence of twin and higher-order multiple pregnancies. (Fertil Steril 2004;81:500 -4.

Research paper thumbnail of The desire of infertility patients for multiple gestations—do they know the risks

Fertility and Sterility, 2002

Fertility and Sterility, Volume 78, Issue null, Pages S67, September 2002, Authors:Ginny L Ryan;S... more Fertility and Sterility, Volume 78, Issue null, Pages S67, September 2002, Authors:Ginny L Ryan;Sunny Zhang; Anuja Dokras; Bradley J Van Voorhis. ... Ginny L Ryan ,; Sunny Zhang ,; Anuja Dokras ,; Bradley J Van Voorhis. Full Text; PDF. No abstract is available. ...

Research paper thumbnail of Preservation of the saphenous vein during inguinal lymphadenectomy decreases morbidity in patients with carcinoma of the vulva

Cancer, 2000

Traditional inguinal lymphadenectomy includes the removal of a portion of the saphenous vein. The... more Traditional inguinal lymphadenectomy includes the removal of a portion of the saphenous vein. The authors hypothesized that preserving the saphenous vein would decrease morbidity without affecting treatment outcome. A retrospective review of 83 patients with carcinoma of the vulva who underwent inguinal lymphadenectomy between 1990-1998 was performed. Postoperative short term and long term complications were evaluated. A total of 139 inguinal dissections were performed in 83 patients. The saphenous vein was preserved in 62 patients and ligated in 77 patients. The clinical characteristics of the patients, the operating time, and the estimated blood loss were not significantly different between the two groups. The incidence rate of short term complications including fever, seroma, phlebitis, lymphocyst, and deep venous thrombosis also was similar. Cellulitis occurred in 39% of the patients who underwent vein ligation compared with 18% of the patients who underwent a vein-sparing procedure (P = 0.006). Short term (< 6 months) lower extremity lymphedema occurred in 70% of the vein-ligated group compared with 32% of the vein-spared group (P < 0. 001). Chronic edema (>/= 2 years) was present in only 3% of the patients who underwent saphenous vein preservation compared with 32% of those who underwent vein ligation (P = 0.003). Chronic lymphedema in the vein-spared group was observed in only one patient who received postoperative radiation. Overall, individuals with preservation of the saphenous vein were less likely to develop complications (56% vs. 23%; P < 0.001). There was no difference in the rate of incidence of recurrent disease between the two groups. Preservation of the saphenous vein during inguinal lymphadenectomy reduces both the short term and long term postoperative complications without affecting treatment outcome. The saphenous vein should be preserved routinely in patients undergoing inguinal lymphadenectomy.

Research paper thumbnail of Preservation of the saphenous vein during inguinal lymphadenectomy decreases morbidity in patients with carcinoma of the vulva

Cancer, 2000

Traditional inguinal lymphadenectomy includes the removal of a portion of the saphenous vein. The... more Traditional inguinal lymphadenectomy includes the removal of a portion of the saphenous vein. The authors hypothesized that preserving the saphenous vein would decrease morbidity without affecting treatment outcome. A retrospective review of 83 patients with carcinoma of the vulva who underwent inguinal lymphadenectomy between 1990-1998 was performed. Postoperative short term and long term complications were evaluated. A total of 139 inguinal dissections were performed in 83 patients. The saphenous vein was preserved in 62 patients and ligated in 77 patients. The clinical characteristics of the patients, the operating time, and the estimated blood loss were not significantly different between the two groups. The incidence rate of short term complications including fever, seroma, phlebitis, lymphocyst, and deep venous thrombosis also was similar. Cellulitis occurred in 39% of the patients who underwent vein ligation compared with 18% of the patients who underwent a vein-sparing procedure (P = 0.006). Short term (< 6 months) lower extremity lymphedema occurred in 70% of the vein-ligated group compared with 32% of the vein-spared group (P < 0. 001). Chronic edema (>/= 2 years) was present in only 3% of the patients who underwent saphenous vein preservation compared with 32% of those who underwent vein ligation (P = 0.003). Chronic lymphedema in the vein-spared group was observed in only one patient who received postoperative radiation. Overall, individuals with preservation of the saphenous vein were less likely to develop complications (56% vs. 23%; P < 0.001). There was no difference in the rate of incidence of recurrent disease between the two groups. Preservation of the saphenous vein during inguinal lymphadenectomy reduces both the short term and long term postoperative complications without affecting treatment outcome. The saphenous vein should be preserved routinely in patients undergoing inguinal lymphadenectomy.

Research paper thumbnail of Angiotensin AT1B Receptor Mediates Calcium Signaling in Vascular Smooth Muscle Cells of AT1A Receptor-Deficient Mice

Our studies on angiotensin II receptor subtype 1A (AT1A) knockout mice define how endogenous rece... more Our studies on angiotensin II receptor subtype 1A (AT1A) knockout mice define how endogenous receptors other than AT1A receptors stimulate changes in cytosolic calcium concentration ([Ca2+]i) in cultured aortic vascular smooth muscle cells (VSMCs). Wild-type cells have a 1.7 ratio of AT1A/AT1B receptor mRNA as determined by semiquantitative reverse transcriptase-polymerase chain reaction. Mutant cells express AT1B receptor mRNA but not that for the AT1A receptor. In wild-type cells with AT1A present, Ang II (10(-7) mol/L) produces a characteristic rapid peak increase in [Ca2+]i of 150 to 180 nmol/L, followed by a plateau phase characterized by a sustained 70 to 80 nmol/L increase in [Ca2+]i. An unexpected finding was that the magnitude and time-dependent pattern of [Ca2+]i changes produced by Ang II were similar in cells that lacked AT1A receptors but possessed AT1B receptors. The response in mutant cells indicates effective coupling of an Ang II receptor to one or more second messenger systems. The similarity of response patterns between cells with and without AT1A receptors suggests that non-AT1A receptors are functionally linked to similar signal transduction pathways in mutant cells. The fact that mutant and wild-type cells exhibit similar patterns of calcium mobilization and entry supports the notion that AT1A and non-AT1A receptors share common signal transduction pathways. The AT2 receptor ligands PD-123319 and CGP-42112 do not alter Ang II effects in either VSMC type, suggesting a paucity of AT2 receptors and/or an absence of their linkage to [Ca2+]i pathways. The nonpeptide AT1 receptor blocker losartan antagonizes Ang II-induced [Ca2+]i increases in both cell groups, supporting mediation by native AT1B receptors and effective coupling of this subtype to second messenger systems leading to calcium entry and mobilization. Our results demonstrate that Ang II causes calcium signaling in AT1A-deficient VSMCs that is mediated by an endogenous losartan-sensitive AT1B receptor.

Research paper thumbnail of Apolipoprotein E Deficiency Leads to Cutaneous Foam Cell Formation in Mice

Journal of Investigative Dermatology, 1995

Apolipoprotein E deficiency leads to familial dysbetalipoproteinemia characterized by increases i... more Apolipoprotein E deficiency leads to familial dysbetalipoproteinemia characterized by increases in serum lipid levels, atherosclerosis, and cutaneous xanthoma. Apolipoprotein E is synthesized in many tissues in the body, including the epidermis. In the present study, we determined whether transgenic mice deficient in apolipoprotein E develop cutaneous xanthoma and the effect of dietary fat intake on these lesions. We also determined whether apolipoprotein E-deficient mice have abnormalities in cutaneous barrier function or stratum corneum structure. Homozygous apolipoprotein E-deficient mice (-/-) fed a high-fat diet displayed a diffuse inflammatory infiltrate in the dermis surrounding fat droplets in macrophages. In homozygous mice (-/-) fed a low-fat diet, similar lesions were seen but they tended to be focal and less prominent. In heterozygous mice (+/-) fed the high-fat diet, a few inflammatory cells were present in the dermis but foam cells were not seen. Control mice (+/+) fed a high-fat diet displayed scattered inflammatory cells in the dermis. Heterozygous mice (+/-) fed a low-fat diet were similar to control mice (+/+) fed a low-fat diet. The extent of foam cell formation correlated directly with the degree of atherosclerosis. There were no abnormalities in permeability-barrier function or stratum corneum structure in apolipoprotein E-deficient mice. Thus, the lack of apolipoprotein E production in the epidermis does not appear to lead to any detectable abnormality in structure or function of the stratum corneum. However, lack of apolipoprotein E leads to cutaneous foam cell formation, presumably secondary to disturbances in lipoprotein metabolism.

Research paper thumbnail of Nerve Regeneration and Cholesterol Reutilization Occur in the Absence of Apolipoproteins E and AI in Mice

Journal of Neurochemistry, 2002

Abstract: Apolipoproteins have been implicated in the salvage and reutilization of myelin cholest... more Abstract: Apolipoproteins have been implicated in the salvage and reutilization of myelin cholesterol during Wallerian degeneration and the subsequent nerve regeneration. Current evidence suggests that myelin cholesterol complexes with apolipoproteins E and A-I to form lipoproteins that are taken up via low-density lipoprotein receptors on myelinating Schwann cells. We recently reported, however, that apolipoprotein E is not required for nerve regeneration or reutilization of myelin cholesterol. We have now investigated nerve regeneration and the reutilization of cholesterol in mutant mice deficient in both apolipoproteins E and A-I. Morphologic examination of nerves 4 and 12 weeks after crush injury revealed that regeneration proceeded at a normal rate in the absence of these apolipoproteins. Autoradiography of regenerating nerves indicated that prelabeled myelin lipid was reutilized in the regenerating myelin. 3-Hydroxy-3-methylglutaryl-CoA reductase, the rate-limiting enzyme in cholesterol synthesis, was down-regulated in the regenerating nerves, indicative of cholesterol uptake via lipoproteins. Prelabeled myelin cholesterol was present in lipoprotein fractions isolated from crushed nerves of mutant mice. These data suggest that there is considerable redundancy in the process of cholesterol reutilization within nerve, and that apolipoproteins other than apolipoproteins E and A-I may be involved in the recycling of myelin cholesterol.

Research paper thumbnail of Hepatic clearance of chylomicron remnants m mice lacking apoprotein E

Biochimica Et Biophysica Acta (bba) - Lipids and Lipid Metabolism, 1994

Control and apoprotein E-deficient mice generated by gene targeting in embryonic stem cells were ... more Control and apoprotein E-deficient mice generated by gene targeting in embryonic stem cells were fed a fat load containing 3H-labeled retinol and the absorbed radioactivity present in the plasma, liver, and carcass measured 6 h later. The radioactivity in the plasma of the apoprotein E-deficient mice was several fold higher than in control animals, but it accounted for less than l/5 of the absorbed radioactivity. In both groups of animals most of the absorbed radioactivity was recovered in the livers. These findings indicate that in apoprotein E-deficient mice chylomicron remnants can be taken up by the liver by a process that does not require the mediation of apoprotein E.

Research paper thumbnail of Paradoxical enhancement of atherosclerosis by probucol treatment in apolipoprotein E-deficient mice

Journal of Clinical Investigation, 1997

Dietary administration of probucol (0.5%, wt/wt) efficiently reduced total plasma cholesterol lev... more Dietary administration of probucol (0.5%, wt/wt) efficiently reduced total plasma cholesterol levels in apolipoprotein E-deficient mice (apoE-/-) by 40%, with decreases in high density lipoprotein (HDL) and apoAI by 70 and 50%, respectively. Paradoxically, however, aortic atherosclerotic plaques in the probucol-treated apoE-/- mice formed more rapidly than in the untreated apoE-/- mice, and the lesions were two to four times larger and more mature regardless of sex, age, and genetic background (P < 10(-)6). Histologically, lesions in probucol-treated mice contained increased fibrous materials and cells other than foam cells, and were commonly associated with focal inflammation and aneurysmal dilatation. Probucol treatment also accelerated lesion development in apoE+/- mice fed an atherogenic diet, indicating that the adverse effect is not dependent on the complete absence of apoE. Furthermore, mice lacking apoE and apoAI have plasma lipoprotein profiles very similar to the probucol-treated apoE-/- mice, but do not have accelerated plaque development. Thus, the enhanced atherosclerosis in the probucol-treated animals is unlikely to be caused by the reduction of HDL and apoAI levels. Our data indicate that a reduction in plasma cholesterol caused by probucol does not necessarily lead to an antiatherogenic effect.

Research paper thumbnail of Generation of Mice Carrying a Mutant Apolipoprotein E Gene Inactivated by Gene Targeting in Embryonic Stem Cells

Proceedings of The National Academy of Sciences, 1992

We have inactivated the endogenous apolipoprotein E (apoE) gene by using gene targeting in mouse ... more We have inactivated the endogenous apolipoprotein E (apoE) gene by using gene targeting in mouse embryonic stem (ES) cells. Two targeting plasmids were used, pJPB63 and pNMC109, both containing a neomycin-resistance gene that replaces a part of the apoE gene and disrupts its structure. ES cell colonies targeted after electroporation with plasmid pJPB63 were identified by the polymerase chain reaction (PCR) followed by genomic Southern analysis. Of 648 G418-resistant colonies analyzed, 9 gave a positive signal after PCR amplification, and 5 of them were confirmed as targeted by Southern blot analysis. The second plasmid, pNMC109, contains the negatively selectable thymidine kinase gene in addition to the neomycin-resistance gene. After electroporation with this plasmid, 177 colonies resistant both to G418 and ganciclovir were analyzed; 39 contained a disrupted apoE gene as determined by Southern blotting. Chimeric mice were generated by blastocyst injection with 6 of the targeted lines. One of the lines gave strong chimeras, three of which transmitted the disrupted apoE gene to their progeny. Mice homozygous for the disrupted gene were produced from the heterozygotes; they appear healthy, even though they have no apolipoprotein E in their plasma.

Research paper thumbnail of Spontaneous Hypercholesterolemia and Arterial Lesions in Mice Lacking Apolipoprotein E

Science, 1992

Apolipoprotein E (apoE) is a ligand for receptors that clear remnants of chylomicrons and very lo... more Apolipoprotein E (apoE) is a ligand for receptors that clear remnants of chylomicrons and very low density lipoproteins. Lack of apoE is, therefore, expected to cause accumulation in plasma of cholesterol-rich remnants whose prolonged circulation should be atherogenic. ApoE-deficient mice generated by gene targeting were used to test this hypothesis and to make a mouse model for spontaneous atherosclerosis. The mutant mice had five times normal plasma cholesterol, and developed foam cell-rich depositions in their proximal aortas by age 3 months. These spontaneous lesions progressed and caused severe occlusion of the coronary artery ostium by 8 months. The severe yet viable phenotype of the mutants should make them valuable for investigating genetic and environmental factors that modify the atherogenic process.

Research paper thumbnail of Targeted Modification of the Apolipoprotein B Gene Results in Hypobetalipoproteinemia and Developmental Abnormalities in Mice

Proceedings of The National Academy of Sciences, 1993

Familial hypobetalipoproteinemia is an autosomal codominant disorder resulting in a dramatic redu... more Familial hypobetalipoproteinemia is an autosomal codominant disorder resulting in a dramatic reduction in plasma concentrations of apolipoprotein (apo) B, cholesterol, and β-migrating lipoproteins. A benefit of hypobetalipoproteinemia is that mildly affected individuals may be protected from coronary vascular disease. We have used gene targeting to generate mice with a modified Apob allele. Mice containing this allele display all of the hallmarks of human hypobetalipoproteinemia: they produce a truncated apoB protein, apoB70, and have markedly decreased plasma concentrations of apoB, β-lipoproteins, and total cholesterol. In addition, the mice manifest several characteristics that are occasionally observed in human hypobetalipoproteinemia, including reduced plasma triglyceride concentrations, fasting chylomicronemia, and reduced high density lipoprotein cholesterol. An unexpected finding is that the modified Apob allele is strongly associated with exencephalus and hydrocephalus. These mice should help increase our understanding of hypobetalipoproteinemia, atherogenesis, and the eitiology of exencephalus and hydrocephalus.

Research paper thumbnail of Nerve Regeneration Occurs in the Absence of Apolipoprotein E in Mice

Journal of Neurochemistry, 1993

Abstract: The concentration of apolipoprotein E (apoE), a high-affinity ligand for the low-densit... more Abstract: The concentration of apolipoprotein E (apoE), a high-affinity ligand for the low-density lipoprotein receptor, increases dramatically in peripheral nerve following injury. This endoneurial apoE is thought to play an important role in the redistribution of lipids from the degenerating axonal and myelin membranes to the regenerating axons and myelin sheaths. The importance of apoE in nerve repair was examined using mutant mice that lack apoE. We show that at 2 and 4 weeks following sciatic nerve crush, regenerating nerves in apoE-deficient mice were morphologically similar to regenerating nerves in control animals, indicating that apoE is not essential for peripheral nerve repair. Moreover, cholesterol synthesis was reduced in regenerating nerves of apoE-deficient mice as much as in regenerating nerves of control animals. These results suggest that the intraneural conservation and reutilization of cholesterol following nerve injury do not require apoE.

Research paper thumbnail of Diet-induced atherosclerosis in mice heterozygous and homozygous for apolipoprotein E gene disruption

Journal of Clinical Investigation, 1994

... Sunny H. Zhang, Robert L. Reddick, Bryan Burkey,* and Nobuyo Maeda Department of Pathology, S... more ... Sunny H. Zhang, Robert L. Reddick, Bryan Burkey,* and Nobuyo Maeda Department of Pathology, School ofMedicine, University ofNorth Carolina at Chapel Hill, North Carolina ... Paired Student t tests were performed for the plasma lipidlevels before and 12 wk after diet feeding. ...

Research paper thumbnail of Differential Expression of the α1 Type VIII Collagen Gene by Smooth Muscle Cells from Atherosclerotic Plaques of Apolipoprotein-E-Deficient Mice

Journal of Vascular Research, 2000

We have investigated the morphology, growth and gene expression of smooth muscle cell (SMC) cultu... more We have investigated the morphology, growth and gene expression of smooth muscle cell (SMC) cultures derived from advanced atherosclerotic plaques and from non-plaque-containing aorta of individual apolipoprotein-E-deficient mice. The initial outgrowth of cells was faster from plaques (P) than from non-plaque segments (NP), but the cells in P cultures divided more slowly than NP cells in subcultures. By the 6th passage, the general growth pattern, morphology, ploidy and response to mitogenic factors of the cells were no longer consistently different in P and NP cultures. However, by the use of differential display, several transcripts were identified that were differentially expressed in three independent pairs of P and NP cultures. One of the transcripts, from a type VIII collagen gene, was elevated in all the P cultures compared to their NP counterparts even at the 40th passage. The alpha1 type VIII collagen transcripts were also readily detectable by RT-PCR in freshly dissected plaques, but not in the normal parts of aortas from the apolipoprotein-E-deficient mice. In situ hybridization showed that the transcripts were limited to the fibrous cap of plaques. Thus, SMCs from atherosclerotic plaques produce type VIII collagen and this differential expression continues when the cells are maintained in tissue culture.

Research paper thumbnail of Aortic atherosclerotic plaque injury in apolipoprotein E deficient mice

Atherosclerosis, 1998

The acute platelet response and chronic smooth muscle cell (SMC) proliferation following aortic i... more The acute platelet response and chronic smooth muscle cell (SMC) proliferation following aortic injury in apolipoprotein E-deficient mice was investigated. The purpose of this study was to evaluate whether thrombus formation would occur following plaque injury, to determine the type of thrombus that developed, and to evaluate SMC proliferation. Aortic injury was performed by squeezing the aorta between forceps. The response to injury reflects the findings primarily associated with plaque disruption. An attempt was made to exclude the use of injured vascular segments that showed marked injury to the media to minimize the effects that medial SMCs may have in thrombus formation. Acute and chronic experiments following injury were terminated at 30 min and at 2 weeks, respectively. Injury in normal and heterozygous mice and nonplaque injury in apolipoprotein E-deficient mice were accompanied by endothelial denudation. In apolipoprotein E-deficient mice, plaque injury, which released plaque contents, foam cells and fragments of foam cells, was followed by thrombus formation that contained degranulating platelets mixed with fibrin. Large platelet-fibrin aggregates were in close contact with disrupted plaques and were mixed with foam cell debris. In addition, small thrombi were in nonplaque areas following plaque disruptions. These thrombi were not associated with injury to the media and most likely represent a heightened thrombogenicity associated with plaque disruption. At 2 weeks following injury, a thickened neointima was present in both wild type and mutant mice. Lipid filled cells were seen only in the media but not in the intima of apo E −/−vessels at 2 weeks. The results suggest that plaque injury in homozygous apolipoprotein E-deficient mice promotes platelet-fibrin thrombus formation and that these thrombi are primarily associated with disrupted plaque contents. The results also suggest that the platelet response and SMC proliferation induced by aortic injury are not altered by hyperlipidemia caused by apolipoprotein E deficiency.

Research paper thumbnail of In vivo cholesterol kinetics in apolipoprotein E-deficient and control mice

The in vivo total body cholesterol transport of homozygous apoE-deficient (-/-) and control (+/+)... more The in vivo total body cholesterol transport of homozygous apoE-deficient (-/-) and control (+/+) mice was evaluated by compartmental analysis of plasma cholesterol decay. Body cholesterol fractional catabolic rates of chow fed mutants were less (-/-, 0.17 +/- 0.02; +/+, 0.51 +/- 0.06 day-1) and body cholesterol contents greater (-/-, 68 +/- 5; +/+, 48 +/- 5 mumol) than controls. The body cholesterol expansion of the chow-fed mutant was extracellular with at least half in plasma. Cholesterol transport, i.e., the mass entering, moving through, and exiting the body each day, was similar (-/-, 6.9 +/- 0.7; +/+, 8.5 +/- 0.9 mumol/day) for homozygotes and controls on chow, and both tripled with cholesterol feeding. Differing from controls, however, mutants had considerable expansions of plasma and body cholesterol (-/-, 166 +/- 21; +/+, 59 +/- 11 mumol) with increments in peripheral tissue cholesterol contents. Cholesterol feeding increased control hepatic cholesterol without a change in plasma, whereas mutants had large increments in plasma cholesterol with no change in liver. Consistent with impaired hepatic uptake of cholesterol, mutants had much slower plasma clearance of lipoprotein cholesterol, as well as slower transfer to catabolic pools than normals. Treatment of homozygotes with lovastatin doubled both plasma cholesterol concentration and body cholesterol transport indicating the importance of apoE-dependent cell cholesterol transfer in synthetic down-regulation with this agent. These data indicate that mice lacking apoE have lower affinity hepatic uptake of plasma remnant cholesterol.(ABSTRACT TRUNCATED AT 250 WORDS)

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Research paper thumbnail of The Desire of Infertile Patients for Multiple Births

Obstetrical & Gynecological Survey, 2004

To determine the proportion of infertile women who prefer a multiple birth over a singleton, pati... more To determine the proportion of infertile women who prefer a multiple birth over a singleton, patient characteristics associated with this desire, and patient knowledge about the risks of multiple births. Design: Prospective analysis. Setting: Academic university hospital-based infertility center and private general gynecology clinic. Patient(s): Four hundred sixty-four female patients with infertility who presented for their initial visit. Main Outcome Measure(s): Demographic characteristics, infertility history, desire regarding multiple births, knowledge of the risks of multiple births, and goals of infertility evaluation and treatment were determined by using a 41-question survey. Univariate analysis was performed to assess patient characteristics associated with the desire for multiple births. Independent factors associated with this desire were assessed by multivariable logistic regression analysis. Result(s): 20.3% of women desired multiples over a singleton gestation. Nulliparity, lower family income, younger patient age, prior evaluation for infertility, longer duration of infertility, and lack of knowledge regarding risks of twin gestations were associated with this desire. Only nulliparity and lower family income were independently associated. Conclusion(s): A sizable minority of infertility patients prefers a multiple birth as their treatment outcome. Patient education may be an effective strategy to reduce the incidence of twin and higher-order multiple pregnancies. (Fertil Steril 2004;81:500 -4.

Research paper thumbnail of The desire of infertile patients for multiple births

Fertility and Sterility, 2004

To determine the proportion of infertile women who prefer a multiple birth over a singleton, pati... more To determine the proportion of infertile women who prefer a multiple birth over a singleton, patient characteristics associated with this desire, and patient knowledge about the risks of multiple births. Design: Prospective analysis. Setting: Academic university hospital-based infertility center and private general gynecology clinic. Patient(s): Four hundred sixty-four female patients with infertility who presented for their initial visit. Main Outcome Measure(s): Demographic characteristics, infertility history, desire regarding multiple births, knowledge of the risks of multiple births, and goals of infertility evaluation and treatment were determined by using a 41-question survey. Univariate analysis was performed to assess patient characteristics associated with the desire for multiple births. Independent factors associated with this desire were assessed by multivariable logistic regression analysis. Result(s): 20.3% of women desired multiples over a singleton gestation. Nulliparity, lower family income, younger patient age, prior evaluation for infertility, longer duration of infertility, and lack of knowledge regarding risks of twin gestations were associated with this desire. Only nulliparity and lower family income were independently associated. Conclusion(s): A sizable minority of infertility patients prefers a multiple birth as their treatment outcome. Patient education may be an effective strategy to reduce the incidence of twin and higher-order multiple pregnancies. (Fertil Steril 2004;81:500 -4.

Research paper thumbnail of The desire of infertility patients for multiple gestations—do they know the risks

Fertility and Sterility, 2002

Fertility and Sterility, Volume 78, Issue null, Pages S67, September 2002, Authors:Ginny L Ryan;S... more Fertility and Sterility, Volume 78, Issue null, Pages S67, September 2002, Authors:Ginny L Ryan;Sunny Zhang; Anuja Dokras; Bradley J Van Voorhis. ... Ginny L Ryan ,; Sunny Zhang ,; Anuja Dokras ,; Bradley J Van Voorhis. Full Text; PDF. No abstract is available. ...

Research paper thumbnail of Preservation of the saphenous vein during inguinal lymphadenectomy decreases morbidity in patients with carcinoma of the vulva

Cancer, 2000

Traditional inguinal lymphadenectomy includes the removal of a portion of the saphenous vein. The... more Traditional inguinal lymphadenectomy includes the removal of a portion of the saphenous vein. The authors hypothesized that preserving the saphenous vein would decrease morbidity without affecting treatment outcome. A retrospective review of 83 patients with carcinoma of the vulva who underwent inguinal lymphadenectomy between 1990-1998 was performed. Postoperative short term and long term complications were evaluated. A total of 139 inguinal dissections were performed in 83 patients. The saphenous vein was preserved in 62 patients and ligated in 77 patients. The clinical characteristics of the patients, the operating time, and the estimated blood loss were not significantly different between the two groups. The incidence rate of short term complications including fever, seroma, phlebitis, lymphocyst, and deep venous thrombosis also was similar. Cellulitis occurred in 39% of the patients who underwent vein ligation compared with 18% of the patients who underwent a vein-sparing procedure (P = 0.006). Short term (< 6 months) lower extremity lymphedema occurred in 70% of the vein-ligated group compared with 32% of the vein-spared group (P < 0. 001). Chronic edema (>/= 2 years) was present in only 3% of the patients who underwent saphenous vein preservation compared with 32% of those who underwent vein ligation (P = 0.003). Chronic lymphedema in the vein-spared group was observed in only one patient who received postoperative radiation. Overall, individuals with preservation of the saphenous vein were less likely to develop complications (56% vs. 23%; P < 0.001). There was no difference in the rate of incidence of recurrent disease between the two groups. Preservation of the saphenous vein during inguinal lymphadenectomy reduces both the short term and long term postoperative complications without affecting treatment outcome. The saphenous vein should be preserved routinely in patients undergoing inguinal lymphadenectomy.

Research paper thumbnail of Preservation of the saphenous vein during inguinal lymphadenectomy decreases morbidity in patients with carcinoma of the vulva

Cancer, 2000

Traditional inguinal lymphadenectomy includes the removal of a portion of the saphenous vein. The... more Traditional inguinal lymphadenectomy includes the removal of a portion of the saphenous vein. The authors hypothesized that preserving the saphenous vein would decrease morbidity without affecting treatment outcome. A retrospective review of 83 patients with carcinoma of the vulva who underwent inguinal lymphadenectomy between 1990-1998 was performed. Postoperative short term and long term complications were evaluated. A total of 139 inguinal dissections were performed in 83 patients. The saphenous vein was preserved in 62 patients and ligated in 77 patients. The clinical characteristics of the patients, the operating time, and the estimated blood loss were not significantly different between the two groups. The incidence rate of short term complications including fever, seroma, phlebitis, lymphocyst, and deep venous thrombosis also was similar. Cellulitis occurred in 39% of the patients who underwent vein ligation compared with 18% of the patients who underwent a vein-sparing procedure (P = 0.006). Short term (< 6 months) lower extremity lymphedema occurred in 70% of the vein-ligated group compared with 32% of the vein-spared group (P < 0. 001). Chronic edema (>/= 2 years) was present in only 3% of the patients who underwent saphenous vein preservation compared with 32% of those who underwent vein ligation (P = 0.003). Chronic lymphedema in the vein-spared group was observed in only one patient who received postoperative radiation. Overall, individuals with preservation of the saphenous vein were less likely to develop complications (56% vs. 23%; P < 0.001). There was no difference in the rate of incidence of recurrent disease between the two groups. Preservation of the saphenous vein during inguinal lymphadenectomy reduces both the short term and long term postoperative complications without affecting treatment outcome. The saphenous vein should be preserved routinely in patients undergoing inguinal lymphadenectomy.

Research paper thumbnail of Angiotensin AT1B Receptor Mediates Calcium Signaling in Vascular Smooth Muscle Cells of AT1A Receptor-Deficient Mice

Our studies on angiotensin II receptor subtype 1A (AT1A) knockout mice define how endogenous rece... more Our studies on angiotensin II receptor subtype 1A (AT1A) knockout mice define how endogenous receptors other than AT1A receptors stimulate changes in cytosolic calcium concentration ([Ca2+]i) in cultured aortic vascular smooth muscle cells (VSMCs). Wild-type cells have a 1.7 ratio of AT1A/AT1B receptor mRNA as determined by semiquantitative reverse transcriptase-polymerase chain reaction. Mutant cells express AT1B receptor mRNA but not that for the AT1A receptor. In wild-type cells with AT1A present, Ang II (10(-7) mol/L) produces a characteristic rapid peak increase in [Ca2+]i of 150 to 180 nmol/L, followed by a plateau phase characterized by a sustained 70 to 80 nmol/L increase in [Ca2+]i. An unexpected finding was that the magnitude and time-dependent pattern of [Ca2+]i changes produced by Ang II were similar in cells that lacked AT1A receptors but possessed AT1B receptors. The response in mutant cells indicates effective coupling of an Ang II receptor to one or more second messenger systems. The similarity of response patterns between cells with and without AT1A receptors suggests that non-AT1A receptors are functionally linked to similar signal transduction pathways in mutant cells. The fact that mutant and wild-type cells exhibit similar patterns of calcium mobilization and entry supports the notion that AT1A and non-AT1A receptors share common signal transduction pathways. The AT2 receptor ligands PD-123319 and CGP-42112 do not alter Ang II effects in either VSMC type, suggesting a paucity of AT2 receptors and/or an absence of their linkage to [Ca2+]i pathways. The nonpeptide AT1 receptor blocker losartan antagonizes Ang II-induced [Ca2+]i increases in both cell groups, supporting mediation by native AT1B receptors and effective coupling of this subtype to second messenger systems leading to calcium entry and mobilization. Our results demonstrate that Ang II causes calcium signaling in AT1A-deficient VSMCs that is mediated by an endogenous losartan-sensitive AT1B receptor.

Research paper thumbnail of Apolipoprotein E Deficiency Leads to Cutaneous Foam Cell Formation in Mice

Journal of Investigative Dermatology, 1995

Apolipoprotein E deficiency leads to familial dysbetalipoproteinemia characterized by increases i... more Apolipoprotein E deficiency leads to familial dysbetalipoproteinemia characterized by increases in serum lipid levels, atherosclerosis, and cutaneous xanthoma. Apolipoprotein E is synthesized in many tissues in the body, including the epidermis. In the present study, we determined whether transgenic mice deficient in apolipoprotein E develop cutaneous xanthoma and the effect of dietary fat intake on these lesions. We also determined whether apolipoprotein E-deficient mice have abnormalities in cutaneous barrier function or stratum corneum structure. Homozygous apolipoprotein E-deficient mice (-/-) fed a high-fat diet displayed a diffuse inflammatory infiltrate in the dermis surrounding fat droplets in macrophages. In homozygous mice (-/-) fed a low-fat diet, similar lesions were seen but they tended to be focal and less prominent. In heterozygous mice (+/-) fed the high-fat diet, a few inflammatory cells were present in the dermis but foam cells were not seen. Control mice (+/+) fed a high-fat diet displayed scattered inflammatory cells in the dermis. Heterozygous mice (+/-) fed a low-fat diet were similar to control mice (+/+) fed a low-fat diet. The extent of foam cell formation correlated directly with the degree of atherosclerosis. There were no abnormalities in permeability-barrier function or stratum corneum structure in apolipoprotein E-deficient mice. Thus, the lack of apolipoprotein E production in the epidermis does not appear to lead to any detectable abnormality in structure or function of the stratum corneum. However, lack of apolipoprotein E leads to cutaneous foam cell formation, presumably secondary to disturbances in lipoprotein metabolism.

Research paper thumbnail of Nerve Regeneration and Cholesterol Reutilization Occur in the Absence of Apolipoproteins E and AI in Mice

Journal of Neurochemistry, 2002

Abstract: Apolipoproteins have been implicated in the salvage and reutilization of myelin cholest... more Abstract: Apolipoproteins have been implicated in the salvage and reutilization of myelin cholesterol during Wallerian degeneration and the subsequent nerve regeneration. Current evidence suggests that myelin cholesterol complexes with apolipoproteins E and A-I to form lipoproteins that are taken up via low-density lipoprotein receptors on myelinating Schwann cells. We recently reported, however, that apolipoprotein E is not required for nerve regeneration or reutilization of myelin cholesterol. We have now investigated nerve regeneration and the reutilization of cholesterol in mutant mice deficient in both apolipoproteins E and A-I. Morphologic examination of nerves 4 and 12 weeks after crush injury revealed that regeneration proceeded at a normal rate in the absence of these apolipoproteins. Autoradiography of regenerating nerves indicated that prelabeled myelin lipid was reutilized in the regenerating myelin. 3-Hydroxy-3-methylglutaryl-CoA reductase, the rate-limiting enzyme in cholesterol synthesis, was down-regulated in the regenerating nerves, indicative of cholesterol uptake via lipoproteins. Prelabeled myelin cholesterol was present in lipoprotein fractions isolated from crushed nerves of mutant mice. These data suggest that there is considerable redundancy in the process of cholesterol reutilization within nerve, and that apolipoproteins other than apolipoproteins E and A-I may be involved in the recycling of myelin cholesterol.

Research paper thumbnail of Hepatic clearance of chylomicron remnants m mice lacking apoprotein E

Biochimica Et Biophysica Acta (bba) - Lipids and Lipid Metabolism, 1994

Control and apoprotein E-deficient mice generated by gene targeting in embryonic stem cells were ... more Control and apoprotein E-deficient mice generated by gene targeting in embryonic stem cells were fed a fat load containing 3H-labeled retinol and the absorbed radioactivity present in the plasma, liver, and carcass measured 6 h later. The radioactivity in the plasma of the apoprotein E-deficient mice was several fold higher than in control animals, but it accounted for less than l/5 of the absorbed radioactivity. In both groups of animals most of the absorbed radioactivity was recovered in the livers. These findings indicate that in apoprotein E-deficient mice chylomicron remnants can be taken up by the liver by a process that does not require the mediation of apoprotein E.

Research paper thumbnail of Paradoxical enhancement of atherosclerosis by probucol treatment in apolipoprotein E-deficient mice

Journal of Clinical Investigation, 1997

Dietary administration of probucol (0.5%, wt/wt) efficiently reduced total plasma cholesterol lev... more Dietary administration of probucol (0.5%, wt/wt) efficiently reduced total plasma cholesterol levels in apolipoprotein E-deficient mice (apoE-/-) by 40%, with decreases in high density lipoprotein (HDL) and apoAI by 70 and 50%, respectively. Paradoxically, however, aortic atherosclerotic plaques in the probucol-treated apoE-/- mice formed more rapidly than in the untreated apoE-/- mice, and the lesions were two to four times larger and more mature regardless of sex, age, and genetic background (P < 10(-)6). Histologically, lesions in probucol-treated mice contained increased fibrous materials and cells other than foam cells, and were commonly associated with focal inflammation and aneurysmal dilatation. Probucol treatment also accelerated lesion development in apoE+/- mice fed an atherogenic diet, indicating that the adverse effect is not dependent on the complete absence of apoE. Furthermore, mice lacking apoE and apoAI have plasma lipoprotein profiles very similar to the probucol-treated apoE-/- mice, but do not have accelerated plaque development. Thus, the enhanced atherosclerosis in the probucol-treated animals is unlikely to be caused by the reduction of HDL and apoAI levels. Our data indicate that a reduction in plasma cholesterol caused by probucol does not necessarily lead to an antiatherogenic effect.

Research paper thumbnail of Generation of Mice Carrying a Mutant Apolipoprotein E Gene Inactivated by Gene Targeting in Embryonic Stem Cells

Proceedings of The National Academy of Sciences, 1992

We have inactivated the endogenous apolipoprotein E (apoE) gene by using gene targeting in mouse ... more We have inactivated the endogenous apolipoprotein E (apoE) gene by using gene targeting in mouse embryonic stem (ES) cells. Two targeting plasmids were used, pJPB63 and pNMC109, both containing a neomycin-resistance gene that replaces a part of the apoE gene and disrupts its structure. ES cell colonies targeted after electroporation with plasmid pJPB63 were identified by the polymerase chain reaction (PCR) followed by genomic Southern analysis. Of 648 G418-resistant colonies analyzed, 9 gave a positive signal after PCR amplification, and 5 of them were confirmed as targeted by Southern blot analysis. The second plasmid, pNMC109, contains the negatively selectable thymidine kinase gene in addition to the neomycin-resistance gene. After electroporation with this plasmid, 177 colonies resistant both to G418 and ganciclovir were analyzed; 39 contained a disrupted apoE gene as determined by Southern blotting. Chimeric mice were generated by blastocyst injection with 6 of the targeted lines. One of the lines gave strong chimeras, three of which transmitted the disrupted apoE gene to their progeny. Mice homozygous for the disrupted gene were produced from the heterozygotes; they appear healthy, even though they have no apolipoprotein E in their plasma.

Research paper thumbnail of Spontaneous Hypercholesterolemia and Arterial Lesions in Mice Lacking Apolipoprotein E

Science, 1992

Apolipoprotein E (apoE) is a ligand for receptors that clear remnants of chylomicrons and very lo... more Apolipoprotein E (apoE) is a ligand for receptors that clear remnants of chylomicrons and very low density lipoproteins. Lack of apoE is, therefore, expected to cause accumulation in plasma of cholesterol-rich remnants whose prolonged circulation should be atherogenic. ApoE-deficient mice generated by gene targeting were used to test this hypothesis and to make a mouse model for spontaneous atherosclerosis. The mutant mice had five times normal plasma cholesterol, and developed foam cell-rich depositions in their proximal aortas by age 3 months. These spontaneous lesions progressed and caused severe occlusion of the coronary artery ostium by 8 months. The severe yet viable phenotype of the mutants should make them valuable for investigating genetic and environmental factors that modify the atherogenic process.

Research paper thumbnail of Targeted Modification of the Apolipoprotein B Gene Results in Hypobetalipoproteinemia and Developmental Abnormalities in Mice

Proceedings of The National Academy of Sciences, 1993

Familial hypobetalipoproteinemia is an autosomal codominant disorder resulting in a dramatic redu... more Familial hypobetalipoproteinemia is an autosomal codominant disorder resulting in a dramatic reduction in plasma concentrations of apolipoprotein (apo) B, cholesterol, and β-migrating lipoproteins. A benefit of hypobetalipoproteinemia is that mildly affected individuals may be protected from coronary vascular disease. We have used gene targeting to generate mice with a modified Apob allele. Mice containing this allele display all of the hallmarks of human hypobetalipoproteinemia: they produce a truncated apoB protein, apoB70, and have markedly decreased plasma concentrations of apoB, β-lipoproteins, and total cholesterol. In addition, the mice manifest several characteristics that are occasionally observed in human hypobetalipoproteinemia, including reduced plasma triglyceride concentrations, fasting chylomicronemia, and reduced high density lipoprotein cholesterol. An unexpected finding is that the modified Apob allele is strongly associated with exencephalus and hydrocephalus. These mice should help increase our understanding of hypobetalipoproteinemia, atherogenesis, and the eitiology of exencephalus and hydrocephalus.

Research paper thumbnail of Nerve Regeneration Occurs in the Absence of Apolipoprotein E in Mice

Journal of Neurochemistry, 1993

Abstract: The concentration of apolipoprotein E (apoE), a high-affinity ligand for the low-densit... more Abstract: The concentration of apolipoprotein E (apoE), a high-affinity ligand for the low-density lipoprotein receptor, increases dramatically in peripheral nerve following injury. This endoneurial apoE is thought to play an important role in the redistribution of lipids from the degenerating axonal and myelin membranes to the regenerating axons and myelin sheaths. The importance of apoE in nerve repair was examined using mutant mice that lack apoE. We show that at 2 and 4 weeks following sciatic nerve crush, regenerating nerves in apoE-deficient mice were morphologically similar to regenerating nerves in control animals, indicating that apoE is not essential for peripheral nerve repair. Moreover, cholesterol synthesis was reduced in regenerating nerves of apoE-deficient mice as much as in regenerating nerves of control animals. These results suggest that the intraneural conservation and reutilization of cholesterol following nerve injury do not require apoE.

Research paper thumbnail of Diet-induced atherosclerosis in mice heterozygous and homozygous for apolipoprotein E gene disruption

Journal of Clinical Investigation, 1994

... Sunny H. Zhang, Robert L. Reddick, Bryan Burkey,* and Nobuyo Maeda Department of Pathology, S... more ... Sunny H. Zhang, Robert L. Reddick, Bryan Burkey,* and Nobuyo Maeda Department of Pathology, School ofMedicine, University ofNorth Carolina at Chapel Hill, North Carolina ... Paired Student t tests were performed for the plasma lipidlevels before and 12 wk after diet feeding. ...

Research paper thumbnail of Differential Expression of the α1 Type VIII Collagen Gene by Smooth Muscle Cells from Atherosclerotic Plaques of Apolipoprotein-E-Deficient Mice

Journal of Vascular Research, 2000

We have investigated the morphology, growth and gene expression of smooth muscle cell (SMC) cultu... more We have investigated the morphology, growth and gene expression of smooth muscle cell (SMC) cultures derived from advanced atherosclerotic plaques and from non-plaque-containing aorta of individual apolipoprotein-E-deficient mice. The initial outgrowth of cells was faster from plaques (P) than from non-plaque segments (NP), but the cells in P cultures divided more slowly than NP cells in subcultures. By the 6th passage, the general growth pattern, morphology, ploidy and response to mitogenic factors of the cells were no longer consistently different in P and NP cultures. However, by the use of differential display, several transcripts were identified that were differentially expressed in three independent pairs of P and NP cultures. One of the transcripts, from a type VIII collagen gene, was elevated in all the P cultures compared to their NP counterparts even at the 40th passage. The alpha1 type VIII collagen transcripts were also readily detectable by RT-PCR in freshly dissected plaques, but not in the normal parts of aortas from the apolipoprotein-E-deficient mice. In situ hybridization showed that the transcripts were limited to the fibrous cap of plaques. Thus, SMCs from atherosclerotic plaques produce type VIII collagen and this differential expression continues when the cells are maintained in tissue culture.

Research paper thumbnail of Aortic atherosclerotic plaque injury in apolipoprotein E deficient mice

Atherosclerosis, 1998

The acute platelet response and chronic smooth muscle cell (SMC) proliferation following aortic i... more The acute platelet response and chronic smooth muscle cell (SMC) proliferation following aortic injury in apolipoprotein E-deficient mice was investigated. The purpose of this study was to evaluate whether thrombus formation would occur following plaque injury, to determine the type of thrombus that developed, and to evaluate SMC proliferation. Aortic injury was performed by squeezing the aorta between forceps. The response to injury reflects the findings primarily associated with plaque disruption. An attempt was made to exclude the use of injured vascular segments that showed marked injury to the media to minimize the effects that medial SMCs may have in thrombus formation. Acute and chronic experiments following injury were terminated at 30 min and at 2 weeks, respectively. Injury in normal and heterozygous mice and nonplaque injury in apolipoprotein E-deficient mice were accompanied by endothelial denudation. In apolipoprotein E-deficient mice, plaque injury, which released plaque contents, foam cells and fragments of foam cells, was followed by thrombus formation that contained degranulating platelets mixed with fibrin. Large platelet-fibrin aggregates were in close contact with disrupted plaques and were mixed with foam cell debris. In addition, small thrombi were in nonplaque areas following plaque disruptions. These thrombi were not associated with injury to the media and most likely represent a heightened thrombogenicity associated with plaque disruption. At 2 weeks following injury, a thickened neointima was present in both wild type and mutant mice. Lipid filled cells were seen only in the media but not in the intima of apo E −/−vessels at 2 weeks. The results suggest that plaque injury in homozygous apolipoprotein E-deficient mice promotes platelet-fibrin thrombus formation and that these thrombi are primarily associated with disrupted plaque contents. The results also suggest that the platelet response and SMC proliferation induced by aortic injury are not altered by hyperlipidemia caused by apolipoprotein E deficiency.

Research paper thumbnail of In vivo cholesterol kinetics in apolipoprotein E-deficient and control mice

The in vivo total body cholesterol transport of homozygous apoE-deficient (-/-) and control (+/+)... more The in vivo total body cholesterol transport of homozygous apoE-deficient (-/-) and control (+/+) mice was evaluated by compartmental analysis of plasma cholesterol decay. Body cholesterol fractional catabolic rates of chow fed mutants were less (-/-, 0.17 +/- 0.02; +/+, 0.51 +/- 0.06 day-1) and body cholesterol contents greater (-/-, 68 +/- 5; +/+, 48 +/- 5 mumol) than controls. The body cholesterol expansion of the chow-fed mutant was extracellular with at least half in plasma. Cholesterol transport, i.e., the mass entering, moving through, and exiting the body each day, was similar (-/-, 6.9 +/- 0.7; +/+, 8.5 +/- 0.9 mumol/day) for homozygotes and controls on chow, and both tripled with cholesterol feeding. Differing from controls, however, mutants had considerable expansions of plasma and body cholesterol (-/-, 166 +/- 21; +/+, 59 +/- 11 mumol) with increments in peripheral tissue cholesterol contents. Cholesterol feeding increased control hepatic cholesterol without a change in plasma, whereas mutants had large increments in plasma cholesterol with no change in liver. Consistent with impaired hepatic uptake of cholesterol, mutants had much slower plasma clearance of lipoprotein cholesterol, as well as slower transfer to catabolic pools than normals. Treatment of homozygotes with lovastatin doubled both plasma cholesterol concentration and body cholesterol transport indicating the importance of apoE-dependent cell cholesterol transfer in synthetic down-regulation with this agent. These data indicate that mice lacking apoE have lower affinity hepatic uptake of plasma remnant cholesterol.(ABSTRACT TRUNCATED AT 250 WORDS)

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