(1/270) Effect of cerivastatin sodium, a new inhibitor of HMG-CoA reductase, on plasma lipid levels, progression of atherosclerosis, and the lesional composition in the plaques of WHHL rabbits.
1. The aim of this study was to examine whether cerivastatin sodium, a new inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, affects the lesional composition of spontaneously developed atherosclerosis due to hypercholesterolaemia and delays progression of the lesions. 2. We administered cerivastatin to 2-month-old WHHL rabbits, a low-density lipoprotein receptor-deficient animal model, at a dose of 0.6 mg kg(-1) day(-1) for 32 weeks. We examined the plasma lipid levels, the severity of atherosclerosis, and composition of atherosclerotic lesions. Lesional composition was determined using immunohistostaining for macrophages and smooth muscle cells, and Azan-Mallory staining for collagen fibres and extracellular lipid deposits. 3. Compared to the control group, the plasma cholesterol levels were decreased in the treated group by 39% (12.7+/-0.6 mmol L(-1) versus 20.9+/-1.0 mmol L(-1), P<0.001). Atherosclerosis was suppressed by about 37% as measured by the thickness of the aortic lesions (158+/-13 microm versus 250+/-15 microm, P<0.001), and by 28% as measured by coronary stenosis (62.7+/-11.4 versus 86.9+/-12.2, P<0.05). In the cerivastatin group, regarding the per cent areas of lesional components in the lesion area, the macrophages (21.0+/-1.5% versus 27.9+/-1.9%, P<0.01) and extracellular lipid deposits (3.2+/-0.4% versus 5.1+/-0.4%, P<0.001) were decreased in the aortic lesions, and the per cent area of macrophages in the coronary lesions was also decreased (4.9+/-1.4% versus, 11.6+/-2.4%. P<0.05). The per cent area of smooth muscle cells and collagen fibres did not significantly decrease. 4. These results indicate that cerivastatin contributed to the plaque stabilization and delayed progression of early atherosclerosis in young WHHL rabbits, in addition to the potent hypolipidemic effects. (+info)
(2/270) Xanthogranulomatous oophoritis--a case report.
This is a case of a 25 year old unmarried women who presented with intermittent fever and lower abdominal pain. Laparotomy revealed a large cystic left sided tuboovarian mass adherent to surrounding structures and containing foul smelling fluid. Microscopy showed extensive replacement of the ovary by a chronic inflammatory exudate composed predominantly of foamy macrophages. (+info)
(3/270) Symptomatic Rathke's cleft cyst coexisting with central diabetes insipidus and hypophysitis: case report.
We describe a 48-year-old female with acute onset of central diabetes insipidus followed by mild anterior pituitary dysfunction. Magnetic resonance imaging (MRI) revealed enlargement of the hypophysis-infundibulum accompanied by a cystic component. She underwent a transsphenoidal exploration of the sella turcica. Histological examination showed foreign body type xanthogranulomatous inflammation in the neurohypophysis which might have been caused by rupture of a Rathke's cleft cyst. The MRI abnormalities and anterior pituitary dysfunction improved after a short course of corticosteroid administration, but the diabetes insipidus persisted. The histological findings in this case indicated the site of RCC rupture and the direction of the progression of RCC induced neurohypophysitis and adenohypophysitis. (+info)
(4/270) Characterization of a novel cellular defect in patients with phenotypic homozygous familial hypercholesterolemia.
Familial hypercholesterolemia (FH) is characterized by a raised concentration of LDL in plasma that results in a significantly increased risk of premature atherosclerosis. In FH, impaired removal of LDL from the circulation results from inherited mutations in the LDL receptor gene or, more rarely, in the gene for apo B, the ligand for the LDL receptor. We have identified two unrelated clinically homozygous FH patients whose cells exhibit no measurable degradation of LDL in culture. Extensive analysis of DNA and mRNA revealed no defect in the LDL receptor, and alleles of the LDL receptor or apo B genes do not cosegregate with hypercholesterolemia in these families. FACS((R)) analysis of binding and uptake of fluorescent LDL or anti-LDL receptor antibodies showed that LDL receptors are on the cell surface and bind LDL normally, but fail to be internalized, suggesting that some component of endocytosis through clathrin-coated pits is defective. Internalization of the transferrin receptor occurs normally, suggesting that the defective gene product may interact specifically with the LDL receptor internalization signal. Identification of the defective gene will aid genetic diagnosis of other hypercholesterolemic patients and elucidate the mechanism by which LDL receptors are internalized. (+info)
(5/270) Severe hyperlipidemia in apolipoprotein E2 homozygotes due to a combined effect of hyperinsulinemia and an SstI polymorphism.
More than 90% of patients with type III hyperlipoproteinemia are homozygous carriers of the apolipoprotein (apo) E*2 allele. The great majority of these apoE2(Arg158-->Cys) homozygotes in the general population, however, are normolipidemic. Apparently, expression of the hyperlipidemic state requires additional genetic and/or environmental factors, suggesting a multifactorial etiology. To elucidate these additional risk factors, we analyzed normolipidemic and hyperlipidemic apoE2 homozygotes. Hyperinsulinemia was observed in 27 of 49 apoE2 homozygotes and associated with elevated lipid levels: hyperinsulinemic apoE2 homozygotes had type III hyperlipoproteinemia 6 times more often than apoE2 homozygotes with normal insulin levels (odds ratio 6.2, P=0.02). We screened the normolipidemic and hyperlipidemic apoE2 homozygotes for common variants in candidate genes involved in lipolysis-the APOA1-C3-A4 gene cluster, lipoprotein lipase, and hepatic lipase-and analyzed for associations with the expression of hyperlipidemia. In the hyperinsulinemic group, the 7 carriers of the SstI polymorphism (S2) in the APOC3 gene displayed severely elevated VLDL cholesterol (P(insulin by SstI)<0.001) and VLDL triglyceride (P(insulin by SstI)<0.01) and low levels of HDL (P(insulin by SstI)<0.02). In the normoinsulinemic group, no such relation of the SstI polymorphism with hyperlipidemia was observed. These data provide the first evidence for a combined effect of hyperinsulinemia and the SstI polymorphism on the expression of hyperlipidemia in apoE2 homozygotes. (+info)
(6/270) Extensive intracranial xanthoma associated with type II hyperlipidemia.
Xanthomas are associated with a spectrum of medical conditions, most commonly disorders of lipid storage and lipid metabolism. They occur primarily in the subcutaneous tissues, especially along the Achilles tendon and the extensor tendons of the hands. Intracranial xanthomas are extremely rare. We present a case of an extensive xanthoma of the temporal bone in a patient with hyperlipidemia. (+info)
(7/270) Massive xanthomatosis and altered composition of atherosclerotic lesions in hyperlipidemic mice lacking acyl CoA:cholesterol acyltransferase 1.
Inhibitors of acyl CoA:cholesterol acyltransferase (ACAT) have attracted considerable interest as a potential treatment for atherosclerosis. Currently available inhibitors probably act nonselectively against the two known ACATs. One of these enzymes, ACAT1, is highly expressed in macrophages in atherosclerotic lesions, where it contributes to foam-cell formation. In this study, we examined the effects of selective ACAT1 deficiency in two mouse models of atherosclerosis. In the setting of severe hypercholesterolemia caused by deficiency in apoE or the LDL receptor (LDLR), total ACAT1 deficiency led to marked alterations in cholesterol homeostasis and extensive deposition of unesterified cholesterol in the skin and brain. Bone marrow transplantation experiments demonstrated that ACAT1 deficiency in macrophages was sufficient to cause dermal xanthomas in hyperlipidemic LDLR-deficient mice. ACAT1 deficiency did not prevent the development of atherosclerotic lesions in either apoE-deficient or LDLR-deficient mice, despite causing relatively lower serum cholesterol levels. However, the lesions in ACAT1-deficient mice were atypical in composition, with reduced amounts of neutral lipids and a paucity of macrophages in advanced lesions. Although the latter findings may be associated with increased lesion stability, the marked alterations in cholesterol homeostasis indicate that selectively inhibiting ACAT1 in the setting of severe hyperlipidemia may have detrimental consequences. (+info)
(8/270) Absence of ACAT-1 attenuates atherosclerosis but causes dry eye and cutaneous xanthomatosis in mice with congenital hyperlipidemia.
Acyl-CoA:cholesterol acyltransferase (ACAT) catalyzes esterification of cellular cholesterol. To investigate the role of ACAT-1 in atherosclerosis, we have generated ACAT-1 null (ACAT-1-/-) mice. ACAT activities were present in the liver and intestine but were completely absent in adrenal, testes, ovaries, and peritoneal macrophages in our ACAT-1-/- mice. The ACAT-1-/- mice had decreased openings of the eyes because of atrophy of the meibomian glands, a modified form of sebaceous glands normally expressing high ACAT activities. This phenotype is similar to dry eye syndrome in humans. To determine the role of ACAT-1 in atherogenesis, we crossed the ACAT-1-/- mice with mice lacking apolipoprotein (apo) E or the low density lipoprotein receptor (LDLR), hyperlipidemic models susceptible to atherosclerosis. High fat feeding resulted in extensive cutaneous xanthomatosis with loss of hair in both ACAT-1-/-:apo E-/- and ACAT-1-/-:LDLR-/- mice. Free cholesterol content was significantly increased in their skin. Aortic fatty streak lesion size as well as cholesteryl ester content were moderately reduced in both double mutant mice compared with their respective controls. These results indicate that the local inhibition of ACAT activity in tissue macrophages is protective against cholesteryl ester accumulation but causes cutaneous xanthomatosis in mice that lack apo E or LDLR. (+info)