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Type 2 diabetes is characterized by both peripheral insulin resistance and reduced insulin secretion by β-cells. The reasons for β-cell dysfunction in this disease are incompletely understood but may include the accumulation of toxic lipids within this cell type. We examined the role of Abca1, a cellular cholesterol transporter, in cholesterol homeostasis and insulin secretion in β-cells. Mice with specific inactivation of Abca1 in β-cells had markedly impaired glucose tolerance and defective insulin secretion but normal insulin sensitivity. Islets isolated from these mice showed altered cholesterol homeostasis and impaired insulin secretion in vitro . We found that rosiglitazone, an activator of the peroxisome proliferator–activated receptor-γ, which upregulates Abca1 in β-cells, requires β-cell Abca1 for its beneficial effects on glucose tolerance. These experiments establish a new role for Abca1 in β-cell cholesterol homeostasis and insulin secretion, and suggest that cholesterol accumulation may contribute to β-cell dysfunction in type 2 diabetes.

Despite low sensitivity, culture of periprosthetic tissue (PPT) specimens on agars and in broths has traditionally been used for the detection of causative microorganisms in patients suspected for prosthetic joint infection (PJI). The aim of this study was to evaluate the added diagnostic value of culturing PPT in blood culture bottles (BCB) over the conventional combination of standard agar and broth alone. This prospective cohort study was conducted over a 12-month period and included consecutive patients undergoing revision arthroplasty. Overall, 113 episodes from 90 subjects were studied; 45 subjects (50.0%) met the Infectious Diseases Society of America (IDSA) criteria for PJI, of whom the majority (75.6%) had an acute infection. Sensitivity and specificity of culture were assessed using IDSA criteria for PJI as gold standard. Although the increase in sensitivity from 84.44 (CI 70.54; 93.51) to 93.33% (81.73; 98.60) was not significant, added diagnostic value of culturing PPT in BCBs was demonstrated by the significantly higher number of detected pathogens in culture sets with BCBs compared to culture without BCBs (61 pathogens in conventional set versus 89 when BCBs were included for 57 PJI episodes, P = <0.0001). In 17 (29.8%) episodes, microorganisms were cultured from BCBs only, and in 9 (52.9%) of these episodes, virulent pathogens were found. This study demonstrates that PPT culture in BCBs leads to isolation of additional microorganisms, both virulent and low-virulent, which were not cultured with use of agars and broths alone. Isolation of additional causative microorganisms has serious consequences for the treatment strategy in PJI.

Prolactin is best known as the polypeptide anterior pituitary hormone, which regulates the development of the mammary gland. However, it became clear over the last decade that prolactin contributes to a broad range of pathologies, including breast cancer. Prolactin is also involved in angiogenesis via the release of pro‐angiogenic factors by leukocytes and epithelial cells. However, whether prolactin also influences endothelial cells, and whether there are functional consequences of prolactin‐induced signalling in the perspective of angiogenesis, remains so far elusive. In the present study, we show that prolactin induces phosphorylation of ERK1/2 and STAT5 and induces tube formation of endothelial cells on Matrigel. These effects are blocked by a specific prolactin receptor antagonist, del1‐9‐G129R‐hPRL. Moreover, in an in vivo model of the chorioallantoic membrane of the chicken embryo, prolactin enhances vessel density and the tortuosity of the vasculature and pillar formation, which are hallmarks of intussusceptive angiogenesis. Interestingly, while prolactin has only little effect on endothelial cell proliferation, it markedly stimulates endothelial cell migration. Again, migration was reverted by del1‐9‐G129R‐hPRL, indicating a direct effect of prolactin on its receptor. Immunohistochemistry and spectral imaging revealed that the prolactin receptor is present in the microvasculature of human breast carcinoma tissue. Altogether, these results suggest that prolactin may directly stimulate angiogenesis, which could be one of the mechanisms by which prolactin contributes to breast cancer progression, thereby providing a potential tool for intervention.

ObjectiveThe aim of this trial was to determine whether obese patients benefit from treatment with rimonabant in terms of progression of carotid atherosclerosis. Rimonabant, a selective cannabinoid-1 receptor blocker, reduces body weight and improves cardiometabolic risk factors in patients who are obese.Design, setting, patients, interventions and resultsA prospective, double-blind, placebo-controlled trial (Atherosclerosis Underlying Development assessed by Intima–media Thickness in patients On Rimonabant (AUDITOR)) randomised 661 patients with abdominal obesity and metabolic syndrome to rimonabant or placebo for 30 months of treatment. The absolute change in the average value for six segments of far wall carotid intima–media thickness from baseline to month 30 was 0.010±0.095 mm in the rimonabant group and 0.012±0.091 mm in the placebo group (p=0.67). The annualised change was an increase of 0.005±0.042 mm for the rimonabant-treated group and 0.007±0.043 mm for the placebo-treated group (p=0.45).ConclusionsThere was no difference in atherosclerosis progression between patients receiving rimonabant for 30 months and those receiving placebo for the primary efficacy measure (absolute change in carotid intima–media thickness). These findings are consistent with a similar study using coronary intravascular ultrasound and another study evaluating the occurrence of cardiovascular events. Our findings suggest that a 5% loss of body weight over a 30-month period with rimonabant is insufficient to modify atherosclerosis progression in the carotid artery in obese patients with metabolic syndrome.Clinical trial registration informationclinicaltrials.gov Identifier: NCT00228176.

Prolactin Levels and the Risk of Future Coronary Artery Disease in Apparently Healthy Men and Women Anne Q. Reuwer, MD ; Marcel ThB Twickler, MD, PhD ; Barbara A. Hutten, PhD ; Frederique W. Molema, MD ; Nicholas J. Wareham, MBBS, PhD ; Geesje M. Dallinga-Thie, PhD ; Roman L. Bogorad, PhD ; Vincent Goffin, PhD ; Mijke Smink-Bol, MD ; John J.P. Kastelein, MD, PhD ; S. Matthijs Boekholdt, MD, PhD and Kay-Tee Khaw, MBBChir From the Departments of Vascular Medicine (A.Q.R., M.Th.B.T., G.M.D.-T., J.J.P.K., S.M.B.), Clinical Epidemiology, Biostatistics and Bioinformatics (B.A.H.), and Cardiology (S.M.B.), Academic Medical Center, Amsterdam, The Netherlands; Department of Pathology (F.W.M., M.S.-B.), RUN Medical Center, Nijmegen, The Netherlands; MRC Epidemiology Unit (N.J.W.), Cambridge, United Kingdom; INSERM (R.L.B., V.G.), U845, Centre de Recherche Croissance et Signalisation, Equipe \"Prl, GH et tumeurs,\" et Université Paris Descartes, Faculté de Médecine, site Necker, Paris, France; and Institute of Public Health and Primary Care (K.-T.K.), University of Cambridge, Cambridge, United Kingdom. Correspondence to Th. B. Twickler, MD, PhD, Academic Medical Center of the University of Amsterdam, Department of Vascular Medicine (F4-111), Meibergdreef 9 1105 AZ Amsterdam, The Netherlands. E-mail T.B.Twickler{at}amc.uva.nl Received January 29, 2009; accepted June 19, 2009. Background— Prolactin is increasingly recognized to play a stimulatory role in the inflammatory response. Because inflammation is considered of crucial importance in the development of atherosclerosis, we aimed to evaluate whether prolactin levels are associated with the occurrence of coronary artery disease (CAD). Methods and Results— We performed a nested case-control study in the prospective EPIC-Norfolk cohort. Cases were apparently healthy men and women, aged 45 to 79 years, who developed fatal or nonfatal CAD (n=882). Controls remained free of CAD (n=1490). Overall, systemic prolactin levels did not differ between cases and controls, and people in the highest prolactin tertile did not have a significantly increased risk of developing future CAD (in men, odds ratio, 1.21; 95% CI, 0.92 to 1.61; in women, odds ratio, 1.12; 95% CI, 0.76 to 1.64). However, in a separate immunohistochemical study, the presence of prolactin receptors could be demonstrated in postmortem human coronary artery plaques (preliminary data). Conclusions— Elevated systemic prolactin levels do not predict CAD in the general population. However, prolactin receptors were found in human coronary artery plaques. This observation may indicate a role of prolactin within atherosclerotic plaques. More studies are needed to define the possible role of prolactin in atherosclerotic plaque development. Key Words: prolactin • inflammation • atherosclerosis • hormones • atherogenesis • coronary artery disease   CLINICAL PERSPECTIVE The online-only Data Supplement is available at http://circgenetics.ahajournals.org/cgi/content/full/CIRCGENETICS.109.853572. Home | Subscriptions | Archives | Feedback | Authors | Help | Circulation Journals Home | AHA Journals Home | Search Copyright © 2009 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. var _rsCI=\"us-lippincott\"; var _rsCG=\"0\"; var _rsDN=\"//secure-us.imrworldwide.com/\"; var _rsSE=1; var _rsSM=1.0;

Atherothrombosis is a multifactorial process, governed by an interaction between the vessel wall, hemodynamic factors and systemic atherothrombotic risk factors. Recent in vitro, human ex vivo and animal studies have implicated the hormone prolactin as an atherothrombotic mediator. To address this issue, we evaluated the anatomy and function of various microvascular beds as well as plasma atherothrombosis markers in patients with elevated prolactin levels. In this pilot study, involving 10 prolactinoma patients and 10 control subjects, sidestream dark field (SDF) imaging revealed a marked perturbation of the sublingual microcirculation in prolactinoma patients compared to control subjects, as attested to by significant changes in microvascular flow index (2.74 ± 0.12 vs. 2.91 ± 0.05, respectively; P  = 0.0006), in heterogeneity index (0.28 [IQR 0.18–0.31] vs. 0.09 [IQR 0.08–0.17], respectively; P  = 0.002) and lower proportion of perfused vessels (90 ± 4.0% vs. 95 ± 3.0%, respectively; P  = 0.016). In the retina, fluorescein angiography (FAG) confirmed these data, since prolactinoma patients more often have dilatated perifoveal capillaries. In plasma, prolactinoma patients displayed several pro-atherogenic disturbances, including a higher endogenous thrombin potential and prothrombin levels as well as decreased HDL-cholesterol levels. Prolactinoma patients are characterized by microvascular dysfunction as well as plasma markers indicating a pro-atherothrombotic state. Further studies are required to assess if prolactin is causally involved in atherothrombotic disease.

Type 2 diabetes is characterized by both peripheral insulin resistance and reduced insulin secretion by beta-cells. The reasons for beta-cell dysfunction in this disease are incompletely understood but may include the accumulation of toxic lipids within this cell type. We examined the role of Abca1, a cellular cholesterol transporter, in cholesterol homeostasis and insulin secretion in beta-cells. Mice with specific inactivation of Abca1 in beta-cells had markedly impaired glucose tolerance and defective insulin secretion but normal insulin sensitivity. Islets isolated from these mice showed altered cholesterol homeostasis and impaired insulin secretion in vitro. We found that rosiglitazone, an activator of the peroxisome proliferator-activated receptor-gamma, which upregulates Abca1 in beta-cells, requires beta-cell Abca1 for its beneficial effects on glucose tolerance. These experiments establish a new role for Abca1 in beta-cell cholesterol homeostasis and insulin secretion, and suggest that cholesterol accumulation may contribute to beta-cell dysfunction in type 2 diabetes.

Cardiovascular diseases (CVDs) account for approximately 30% of all deaths globally. The most important cause of CVD is atherothrombosis, in other words, narrowing of the arteries as a result of the deposition of cholesterol and other lipoid substances within the arterial wall. Several endocrine disorders have been linked to this pathological state. Recent clinical and experimental studies have suggested that prolactin, a pleiotropic pituitary hormone, may potentially contribute to CVD, either through direct modulation of local cellular processes within atherosclerotic plaques/thrombi and/or through influencing conventional cardiovascular metabolic risk factors. However, the precise role of prolactin in the pathology of CVD remains largely unknown. Here, the authors speculate whether prolactin-lowering treatment may become a future therapeutic approach in patients with elevated prolactin levels and concomitantly presenting with coexisting vascular disease or a significantly elevated risk for premature atherothrombotic vascular disease. Awareness of these new developments may also change our clinical opinions about therapeutic strategies in patients with prolactinomas.