Effect of ezetimibe/simvastatin compared with atorvastatin on lipoprotein subclasses in patients with type 2 diabetes and hypercholesterolaemia.

AIM: To evaluate the effects of the usual starting and next higher doses of ezetimibe/simvastatin and atorvastatin on the cholesterol content of lipoprotein subclasses in patients with type 2 diabetes and hypercholesterolaemia. METHODS: This post hoc analysis compared the effects of treatment with ezetimibe/simvastatin 10/20 mg vs. atorvastatin 10 and 20 mg/day and ezetimibe/simvastatin 10/40 mg/day vs. atorvastatin 40 mg/day on the cholesterol content of lipoprotein subclasses in the modified intent-to-treat (mITT) population (n = 1013) and in subgroups of patients with triglyceride (TG) levels <200 mg/dl (n = 600) and >or=200 mg/dl (2.6 mmol/l) (n = 413). RESULTS: Ezetimibe/simvastatin significantly reduced low-density lipoprotein cholesterol (LDL-C) subclasses LDL(1)-C, LDL(2)-C and LDL(3)-C; real LDL-C (LDL-C(r)); intermediate-density lipoprotein cholesterol (IDL-C), IDL(1)-C, IDL(2)-C; very low-density lipoprotein cholesterol (VLDL-C), VLDL(3)-C; and remnant-like lipoprotein cholesterol (RLP-C) from baseline more than atorvastatin at all dose comparisons (p < 0.01) in the mITT population. Significant improvements were also observed in high-density lipoprotein cholesterol (HDL-C) subclass HDL(3)-C at the ezetimibe/simvastatin 10/20 mg vs. atorvastatin 20 mg and highest dose comparisons (p < 0.001) and in VLDL(1 + 2)-C at the lowest and highest dose comparisons (p < 0.001). Changes in LDL(4)-C and LDL-C subclass patterns (A, B and I) were comparable for both treatments. Generally, similar results were observed for patients with TG levels <200 and >or=200 mg/dl (2.3 mmol). For both treatments, notable differences between TG subgroups were that patients with elevated TGs had smaller reductions in LDL(2)-C, slightly smaller decreases in all IDL subclasses and greater decreases in all VLDL-C subclasses than those with lower TG levels. Frequency of pattern B was also reduced more in patients with higher TGs for both treatments. CONCLUSIONS: Ezetimibe/simvastatin reduced the cholesterol content of most lipoprotein subclasses from baseline with generally similar efficacy in patients with low and high TGs. Despite the different mechanism of action of ezetimibe, the response to ezetimibe/simvastatin and atorvastatin treatment related to these lipoprotein subclasses was generally consistent with the overall effects of these therapies on the major lipid/lipoprotein classes. The clinical significance of these results awaits further study.

Tumor necrosis factor-alpha modulates monocyte/macrophage apoprotein E gene expression.

apo E has been shown to modulate cholesterol balance in arterial wall cells. Production of apo E by macrophages in atherosclerotic plaques could thereby influence the development of the plaque lesion. Cytokines, including TNF alpha, have been identified in human lesions, therefore, we undertook a series of studies to evaluate the effect of TNF alpha on monocyte/macrophage apo E production. The addition of TNF alpha to freshly isolated human monocytes led to a four- to fivefold increase of apo E mRNA abundance. The addition of TNF alpha to fully differentiated macrophages either had no effect or modestly inhibited apo E mRNA expression. THP1 human monocytic cells also responded to TNF alpha in a phenotype-specific manner. Treatment of these cells with TNF alpha produced a dose- and time-dependent increase in apo E mRNA. This increase was reflected in apo E synthesis and was associated with inhibition of DNA synthesis, and with induction of c-fos and ICAM-1 gene expression. Cell-permanent analogues of ceramide did not reproduce TNF alpha effect on apo E, but antagonists of protein kinase C did inhibit its effect. TNF alpha induction of apo E mRNA abundance was associated with stimulation of apo E promoter-dependent gene transcription. In summary, TNF alpha stimulates apo E gene transcription, mRNA abundance, and protein synthesis in the monocyte/macrophage in a phenotype-specific manner. Such regulation could significantly modify the amount of apo E present in vessel wall lesions.

Dexamethasone modulates lipoprotein metabolism in cultured human monocyte-derived macrophages. Stimulation of scavenger receptor activity.

Human monocyte-derived macrophages (HMM) play a key role in the formation of atherosclerotic plaques by accumulating cholesteryl ester (CE) to become foam cells. HMM have receptors for native low density lipoprotein (LDL) and acetylated-LDL (ALDL), and uptake of ALDL can promote substantial cellular CE accumulation. Furthermore, macrophages specifically and saturably bind glucocorticoids, which in turn modulate numerous macrophage functions. Preincubating HMM in dexamethasone-inhibited LDL degradation (230 +/- 12 vs. 515 +/- 21 ng/mg cell protein X 18 h, P less than 0.001) but stimulated ALDL degradation (5.3 +/- 0.5 vs. 2.5 +/- 0.3 micrograms/mg X 18 h, P less than 0.01). These effects were time- and dose-dependent, occurring maximally by 24 h and with 2.5 X 10(-8) M dexamethasone. Dexamethasone increased the maximum velocity for ALDL degradation (16.2 vs. 12.0 micrograms/mg X 18 h, P less than 0.01) without changing the apparent Michaelis constant. Progesterone, 11 alpha-epicortisol, and 17 alpha-OH progesterone (a competitive antagonist of the glucocorticoid receptor) had no effect on HMM ALDL degradation, but 17 alpha-OH progesterone abolished the stimulatory action of dexamethasone. In he presence of ALDL, incorporation of [14C]oleic acid into CE was enhanced over fourfold by dexamethasone (4015 +/- 586 vs. 943 +/- 91 cpm/mg X 2 h, P less than 0.01), and HMM incubated with ALDL and dexamethasone accumulated more free cholesterol (34.6 +/- 1.9 vs. 26.2 +/- 0.8 micrograms/mg, P less than 0.02) and CE (32.8 +/- 2.3 vs. 14.8 +/- 0.8 micrograms/mg, P less than 0.002) than did macrophages without dexamethasone. In cultured human umbilical vein endothelial cells, dexamethasone did not change ALDL degradation, but reduced LDL degradation by 30% (P less than 0.001). In summary, dexamethasone inhibits LDL receptor activity by both macrophages and endothelial cells, but stimulates ALDL receptor activity only in macrophages. These observations provide evidence for the regulation of macrophage endocytic receptors by glucocorticoid hormones.

Growth-related modulation of human skin fibroblast cholesterol distribution and metabolism.

The relationship between cell growth state and the metabolism and distribution of cellular cholesterol was studied in human skin fibroblasts. Cells made quiescent by serum starvation maintained a smaller fraction of total free cholesterol in a pool susceptible to oxidation by added cholesterol oxidase compared to growing cells. The growth-related differences in the distribution of free cholesterol were magnified in cells which were preincubated in low-density lipoprotein. These latter cells hydrolyzed cholesteryl ester which had accumulated in the presence of LDL, resulting in an increased level of cellular free cholesterol after growth activation. By preincubating cells in [3H]cholesterol linoleate-labeled LDL, it could be demonstrated that activation of cell growth facilitated the appearance of LDL-derived cholesterol in a pool accessible to cholesterol oxidase. These studies suggest that onset of growth in fibroblasts leads to a redistribution of free cholesterol from intracellular to plasma membrane compartments. Furthermore, activation of cell growth in cholesterol loaded cells leads to the net conversion of cholesteryl ester to free cholesterol and most of the latter is in the plasma membrane.

Sterols and inhibitors of sterol transport modulate the degradation and secretion of macrophage ApoE: requirement for the C-terminal domain.

Macrophage-derived apoE, produced in the vessel wall, may have important effects during atherogenesis. The production of apoE by macrophages can be regulated at a transcriptional level by cellular differentiation state, cytokines and sterol loading. In addition, there are post-transcriptional and post-translational loci for regulation. We have recently identified an intermediate density cell membrane fraction in which the degradation of apoE can be modulated by sterols. Suppressing degradation of apoE in this fraction by pre-incubating cells in sterols led to enhanced apoE secretion. In this report we demonstrate that the suppressive effect of sterols on the degradation of newly synthesized apoE in this fraction depends on the presence on its C-terminal domain, by studying a macrophage cell line transfected to express a mutant form of apoE in which amino acids beyond amino acid 202 were deleted. In addition, two modulators of cellular sterol transport, progesterone and U1866A, inhibited the degradation of full-length apoE. In contrast, incubation of cells in the acyl-CoA:cholesterol acyltransferase inhibitor S58035 did not influence apoE degradation. As would be predicted based on the results of degradation assays, U1866A, but not S58035, increased the secretion of apoE from a cell line transfected to constitutively express full-length apoE cDNA. The effect of U1866A on apoE degradation, like the effect of sterol, required the presence of the apoE C-terminal domain. Our results indicate that alteration of intracellular sterol homeostasis by pre-incubation in sterols or by drugs that modify the subcellular transport of sterol, modulates the susceptibility of apoE to degradation and that this modulation requires the presence of C-terminal lipid binding domains.

Evaluation of the role of Ap1-like proteins in the enhanced apolipoprotein E gene transcription accompanying phorbol ester induced macrophage differentiation.

Differentiation of THP1 monocytes to a macrophage phenotype is accompanied by increased apolipoprotein E gene transcription. Using transfection analysis with 5' deletion mutations of the 5' control region of the apo E gene in THP1 cells, we show that the -651 to +86 chloramphenicol acetyltransferase (CAT) construct is efficiently expressed in the monocyte; as has been reported for other cell types. Further, we found that an 176 bp region between -623 to -447 was required for the induction of apolipoprotein E gene transcription during 12-O-tetradecanoylphorbol-13-acetate-induced differentiation of monocytes to macrophages. Gel-retardation patterns of the apolipoprotein E promoter region using nuclear extracts from differentiated or undifferentiated THP1 cells revealed altered binding of Ap1-like nuclear factor/s to the -620 to -583 bp region after macrophage differentiation. Mutation of an Ap1 element at position -602 abolished specific binding of Ap1-like proteins to the -620 to -583 bp fragment of the apo E gene and significantly reduced expression of a -623 to +86 apo E-CAT construct during differentiation. These data indicate that differentiation-related expression of the apolipoprotein E gene following phorbol ester stimulation is transduced by gene elements between -623 and -447. Furthermore, the data indicate that transcriptional activation of the apo E gene during macrophage differentiation is associated with induction of Ap1-like proteins which bind to the Ap1 response element present at -602 in the apolipoprotein E gene and importantly contribute to enhanced gene expression.

Early kinetics of human macrophage apolipoprotein E synthesis and incorporation of carbohydrate precursors.

Apolipoprotein E was detected in human macrophage lysates after 4-120-min pulses with [35S]methionine. Significant levels of apolipoprotein E were not found in the media until 120 min. Incorporation of N-[3H]acetylmannosamine, a sialic acid precursor, into apolipoprotein E was measurable after 120 min, whereas no [3H]mannose incorporation could be observed. These methods will be useful for examining the regulation of apolipoprotein E secretion and carbohydrate processing.

In vivo stimulation of low-density lipoprotein degradation by insulin.

The effect of insulin on low-density lipoprotein (LDL) metabolism in vivo was evaluated using the euglycemic insulin clamp technique. In seven subjects, mononuclear cells isolated after a 4-h insulin infusion degraded more 125I-labeled LDL than cells isolated after a saline infusion in six control subjects. In addition, insulin caused the accelerated disappearance of 125I-labeled LDL from plasma in subjects previously injected with autologous 125I-LDL. Infusion of saline had no such effect. These data suggest that insulin, in vivo, stimulates LDL catabolism and could thereby influence LDL cholesterol levels. Insulin-induced stimulation of LDL catabolism could account for the reduction of LDL-cholesterol levels observed in intensively treated type I diabetic patients.

Sterol efflux mediated by endogenous macrophage ApoE expression is independent of ABCA1.

Sterol efflux importantly contributes to preservation of cellular cholesterol homeostasis, and multiple pathways may be involved for mediating such efflux. Recently, an important role has been ascribed to ABCA1 in facilitating lipid efflux from cells, including macrophages, to extracellular lipid-free apolipoproteins. Macrophages are relatively unique among cells because they express apoprotein E (apoE) as a major protein product, and this endogenous expression of apoE increases sterol and phospholipid efflux from macrophages. The studies in this article were designed to test whether the sterol efflux mediated by the endogenous expression of apoE in macrophages was dependent on ABCA1 expression. These studies were facilitated by comparing apoE-expressing J774 cells (J774E(+)) with nonexpressing parental cells (J774E(-)). Sterol efflux was higher from J774E(+) cells compared with J774E(-) cells, but the increment in efflux between these cell types was not increased by induction of ABCA1 expression with cAMP. Induction of ABCA1 with cAMP, however, did increase sterol efflux to exogenously added apoA1 from both cell types. Inhibitors of ABCA1 activity significantly reduced (by 40% to 50%) sterol efflux from both J774E(+) and J774E(-) cells treated with cAMP and apoA1. This inhibitor did not, however, reduce the increment in sterol efflux due to the expression of endogenous apoE. The results of these studies indicate that the increment in sterol efflux mediated by the endogenous expression of apoE in macrophages does not depend on ABCA1 expression or activity.

Lymphocytic hypophysitis. Associated with antiparietal cell antibodies and vitamin B12 deficiency.

Lymphocytic hypophysitis has been recognized as a distinct clinicopathologic entity. It is a cause of hypopituitarism in the postpartum period and is believed to have an autoimmune pathogenesis. We treated a patient with lymphocytic hypophysitis with two unique features. First, this patient had had a prolactin level of 101 ng/mL (normal, 0 to 25 ng/mL). To our knowledge, this degree of elevation has not been previously reported and is a level that might cause confusion with prolactin-secreting pituitary adenomas. Second, this patient had positive titers for antiparietal cell antibodies in conjunction with a low vitamin B12 level and anemia. To our knowledge, this is the first report of a clinically important autoantibody to extrapituitary tissue in a living patient with lymphocytic hypophysitis.

Increased prevalence of significant coronary artery calcification in patients with diabetes.

OBJECTIVE: Coronary artery disease is the major cause of morbidity and mortality in patients with diabetes. Detection of coronary artery disease before the first myocardial infarction and before anginal symptoms will allow for strategies designed to reduce the cardiovascular event rate in this group of patients. Electron beam-computed tomography (EBCT) is a noninvasive technology for evaluating the extent of coronary artery atherosclerosis that relies on the detection of coronary artery calcium (CAC). We used EBCT to detect significant coronary artery atherosclerosis in diabetic patients without symptoms of heart disease. RESEARCH DESIGN AND METHODS: We used EBCT to evaluate calcium in the coronary arteries of 139 consecutive diabetic patients scanned over a 20-month period. The CAC scores in this group were compared with a randomly selected nondiabetic control group and a control group that was selected to match a number of established cardiovascular risk factors. RESULTS: Patients with diabetes had a significant increase in the prevalence of CAC scores > or =400 (25.9%) compared with the randomly selected (7.2%) and matched (14.4%) nondiabetic control groups. Scores in this range have been reported to be highly predictive for abnormal stress myocardial perfusion tomography and subsequent coronary events. CONCLUSIONS: Our results, therefore, indicate a substantial prevalence of significant coronary artery disease in an asymptomatic diabetic patient population compared with nondiabetic control subjects. They also suggest that EBCT may be a useful approach for selecting a group of diabetic subjects who would benefit most from additional evaluation for subclinical coronary artery disease.

Clinical evaluation of a semipermeable polymeric membrane dressing for the treatment of chronic diabetic foot ulcers.

OBJECTIVE: To evaluate the utility of a semipermeable polymeric membrane dressing for the treatment of chronic diabetic foot ulcers. RESEARCH DESIGN AND METHODS: Nineteen subjects with either insulin-dependent diabetes mellitus (IDDM) or non-insulin-dependent diabetes mellitus (NIDDM) and foot ulcers were randomly assigned to the polymeric dressing or conventional wet-to-dry saline dressings. Subjects had foot ulcer site measurements performed every 3 weeks. The subjects using conventional therapy were allowed to cross over to polymeric dressing after 2 months. RESULTS: At the end of 2 months, in the patients using the polymeric dressing, ulcer size was reduced to 35 +/- 16% of baseline. The patients on conventional therapy had an ulcer size of 105 +/- 28% of baseline (P < 0.03, polymeric vs. conventional). Patients initially treated with wet-to-dry saline were crossed over into the polymeric membrane treatment and demonstrated a decrease to 35 +/- 11% of baseline size (p < 0.02) after an additional 2 months. CONCLUSIONS: The semipermeable polymeric membrane dressing is a useful therapeutic option for treating uncomplicated chronic diabetic foot ulcers.

Effects of feeding fish oil on the properties of lipoproteins isolated from rhesus monkeys consuming an atherogenic diet.

This study examined plasma lipids and lipoproteins of rhesus monkeys fed fish oil incorporated into a highly atherogenic diet containing saturated fat and cholesterol. The animals were fed diets containing 2% cholesterol and either 25% coconut oil (group I), 25% fish oil/coconut oil (1:1; group II), or 25% fish oil/coconut oil (3:1; group III) for 12 months (n = 8/group). Adding menhaden fish oil to the diet increased plasma eicosapentaenoic acid and docosahexaenoic acid and decreased plasma linoleic acid in animals fed the fish oil containing diets. Plasma concentrations of all lipoprotein fractions were decreased in the fish oil groups. VLDL isolated from group I animals exhibited beta-mobility on agarose gels but the VLDL from groups II and III animals did not. The group I VLDL was more highly enriched in cholesteryl ester than was VLDL from groups II and III. Group I LDL had a small but significant increase in cholesteryl ester content compared to group III LDL. No differences in HDL composition were observed in the 3 groups. At least 6 times less apo E was recovered in VLDL, IDL, and LDL from group III animals than from group I animals. Assuming 1 molecule of apo B per lipoprotein particle, there were 50% fewer VLDL, IDL, and LDL particles in group III than in group I animals. Group III also had significantly lower molar ratios of apo E/apo B in VLDL, IDL, and LDL than did group I animals. When VLDL from all 3 groups were incubated with J774 macrophages at equal protein concentrations, only the VLDL from the group I animals stimulated cholesterol esterification. Thus, introducing fish oil into an atherogenic diet reduced the number of VLDL, IDL and LDL particles in plasma by as much as 50%, reduced the cholesteryl ester content of the circulating lipoprotein, and reduced the ability of the VLDL to stimulate cholesterol esterification in macrophages.

Synchronous occurrence of parathyroid carcinoma and adenoma in an elderly woman.

The simultaneous occurrence of parathyroid carcinoma and other pathologic conditions of the parathyroid on a sporadic basis is extremely rare. Parathyroid exploration in an otherwise healthy 78-year-old woman with no underlying risk factors revealed synchronous right upper parathyroid adenoma and left upper parathyroid carcinoma. The patient's modest hypercalcemia (11.5 to 12.3 mg/dl) was seemingly at variance with remarkable parathormone elevations of 30 to 70 times normal.

Low density lipoprotein receptor activity in freshly isolated human blood monocytes and lymphocytes.

Circulating human monocytes and lymphocytes were isolated by counterflow and density gradient centrifugation. Binding and degradation of low density lipoprotein (LDL) occurred predominantly in monocytes and to a much lesser extent in lymphocytes. The findings were consistent with greater LDL receptor activity in freshly isolated monocytes than lymphocytes, in keeping with differences in other cell surface receptors between these two cell types. Therefore, when freshly isolated mixed mononuclear cells are used to study LDL receptor activity in vivo in humans, careful attention needs to be given to the proportions of monocytes and lymphocytes, or alternatively, relatively pure preparations of monocytes should be used.

Thyrotropin-secreting pituitary adenoma responsive to bromocriptine therapy.

OBJECTIVE: To describe a case of a thyrotropin-secreting pituitary adenoma that responded to bromocriptine therapy by suppression of thyrotropin and tumor shrinkage. METHODS: We present the clinical course, laboratory data, and radiographic findings in a 32-year-old woman with a thyrotropin-secreting pituitary adenoma before and after treatment with bromocriptine. RESULTS: The patient's pituitary tumor was detected after she had been treated with radioactive iodine for thyrotoxicosis presumed to be due to Graves' disease. After thyroid ablation, the thyrotropin levels could not be brought into the normal range, even while the patient was receiving supraphysiologic doses of orally administered levothyroxine. Magnetic resonance imaging of the pituitary, along with hormonal workup, confirmed the diagnosis of a thyrotropin-secreting pituitary adenoma. Because the tumor was not threatening vital structures and was considered incurable by operation, medical therapy was elected. A trial of bromocriptine was initiated at 15 mg/day and increased to 30 mg/day in three divided doses. Follow-up hormonal studies showed that thyrotropin levels declined into the suppressed range, and repeated magnetic resonance imaging scans showed substantial shrinkage of the pituitary lesion. CONCLUSION: Thyrotropin-secreting tumors may respond hormonally and structurally to bromocriptine therapy. In patients with such tumors, a trial of dopamine agonists at high dose may be considered before initiation of more invasive medical treatment.

Atherosclerosis and apoprotein E. An enigmatic relationship.

In this article, we consider the role of apoprotein E in lipoprotein metabolism and especially in the metabolism of potentially atherogenic lipoproteins. Particular consideration has been given to three features of apoprotein E involvement in lipid cell interactions. Evidence implicating free cholesterol as a mediator of apoprotein E biosynthesis in cholesterol-loaded macrophages is presented. Experiments pointing to apoprotein E as the ligand promoting the interaction of beta-very-low-density lipoprotein (beta-VLDL) with macrophages are summarized. Finally, we describe the influence of fat and cholesterol fed to rhesus monkeys and baboons on the generation of hepatogenous (from isolated liver perfusates) VLDL enriched in cholesterol ester and apoprotein E. These hepatic VLDLs, none of which exhibits beta-electrophoretic mobility, promote cholesterol esterification in macrophages in proportion to their apoprotein E content. The complex role of apoprotein E in the genesis and reversal of atherosclerosis is briefly discussed.

[Injuries in pregnancy]. / Traumi in gravidanza.

From a review of the literature on this subject it emerges that around 6-7% of women are injured during the course of pregnancy. Road accidents, falls and domestic accidents are the most frequent events: it is therefore important to provide pregnant women with information to prevent such events which may endanger both maternal and fetal health.

[Postpartum depression]. / Depressione post-partum.

From a review of the literature it emerges that postnatal depression is present in 10-15% of women during the first year after birth. Some studies have showed that a higher percentage of women with problems of depression commit infanticide compared to non-depressed women. A number of studies have been performed to identify the risk factors which may be used to predict postnatal depression during pregnancy; it is important that gynecologists recognise these factors in order to prevent the onset of this pathology during the postnatal period. Another aspect which emerges from the literature is that the absence of social rituals surrounding birth in the industrialised society, in which the transition role of the new mother is not always recognised, may be an important factor in the etiology of postnatal depression.