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Pluripotent stem cell‐derived kidney organoids hold great promise as a potential auxiliary transplant tissue for individuals with end‐stage renal disease and as a platform for studying kidney diseases and drug discovery. To establish accurate models, it is crucial to thoroughly characterize the morphological features and maturation stages of the cellular components within these organoids. Nephrons, the functional units of the kidney, possess distinct morphological structures that directly correlate with their specific functions. High spatial resolution imaging emerges as a powerful technique for capturing ultrastructural details that may go unnoticed with other methods such as immunofluorescent imaging and scRNA sequencing. In our study, we have applied software capable of seamlessly stitching virtual slides generated from electron microscopy, resulting in high‐definition overviews of tissue slides. With this technology, we can comprehensively characterize the development and maturation of kidney organoids when transplanted under the renal capsule of mice. These organoids exhibit advanced ultrastructural developments upon transplantation, including the formation of the filtration barrier in the renal corpuscle, the presence of microvilli in the proximal tubule, and various types of cell sub‐segmentation in the connecting tubule similarly to those seen in the adult kidney. Such ultrastructural characterization provides invaluable insights into the structural development and functional morphology of nephron segments within kidney organoids and how to advance them by interventions such as a transplantation. Research HighlightsHigh‐resolution imaging is crucial to determine morphological maturation of hiPSC‐derived kidney organoids. Upon transplantation, refined ultrastructural development of nephron segments was observed, such as the development of the glomerular filtration barrier. [ABSTRACT FROM AUTHOR]

Background: This study investigated the clinical value of adding the sFlt-1/PlGF ratio to the spot urine protein/creatinine ratio (PCr) in women with suspected pre-eclampsia. Methods: This was a prospective cohort study performed in a tertiary referral centre. Based on the combination of PCr (< 30) and sFlt-1/PlGF (≤38) results, four groups were described: a double negative result, group A−/−; a negative PCr and positive sFlt-1/PlGF, group B−/+; a positive PCr and negative sFlt-1/PlGF, group C+/−; and a double positive result, group D+/+. The primary outcome was the proportion of false negatives of the combined tests in comparison with PCr alone in the first week after baseline. Secondary, a cost analysis comparing the costs and savings of adding the sFlt-1/PlGF ratio was performed for different follow-up scenarios. Results: A total of 199 women were included. Pre-eclampsia in the first week was observed in 2 women (2%) in group A−/−, 12 (26%) in group B−/+, 4 (27%) in group C+/−, and 12 (92%) in group D+/+. The proportion of false negatives of 8.2% [95% CI 4.9–13.3] with the PCr alone was significantly reduced to 1.6% [0.4–5.7] by adding a negative sFlt-1/PlGF ratio. Furthermore, the addition of the sFlt-1/PlGF ratio to the spot urine PCr, with telemonitoring of women at risk, could result in a reduction of 41% admissions and 36% outpatient visits, leading to a cost reduction of €46,- per patient. Conclusions: Implementation of the sFlt-1/PlGF ratio in addition to the spot urine PCr, may lead to improved selection of women at low risk and a reduction of hospital care for women with suspected pre-eclampsia. Trial registration: Netherlands Trial Register (NL8308). [ABSTRACT FROM AUTHOR]

Introduction: Proliferative glomerulonephritis manifests in a range of renal diseases and is characterized by the influx of inflammatory cells into the glomerulus. Heparan sulfate (HS) is an important (co-)receptor for binding of chemokines, cytokines and leukocytes to the endothelial glycocalyx, a thick glycan layer that covers the inside of blood vessels. During glomerulonephritis, HS in the glomerular endothelial glycocalyx plays a central role in chemokine presentation and oligomerization, and in binding of selectins and integrins expressed by leukocytes. We hypothesize that distinct endothelial HS domains determine the binding of different chemokines. In this study we evaluated the interaction of three pro-inflammatory chemokines (CXCL1, CXCL2 and CCL2) with mouse glomerular endothelial cells (mGEnC-1) in ELISA in competition with different HS preparations and anti-HS single chain variable fragment (scFv) antibodies specific for distinct HS domains. Results: HS appeared to be the primary ligand mediating chemokine binding to the glomerular endothelial glycocalyx in vitro. We found differential affinities of CXCL1, CXCL2 and CCL2 for HS in isolated mGEnC-1 glycocalyx, heparan sulfate from bovine kidney or low molecular weight heparin in competition ELISAs using mGEnC-1 as a substrate, indicating that chemokine binding is affected by the domain structure of the different HS preparations. Blocking of specific HS domains with anti-HS scFv antibodies revealed a domain-specific interaction of the tested chemokines to HS on mGEnC-1. Furthermore, chemokines did not compete for the same binding sites on mGEnC-1. Conclusion: CXCL1, CXCL2 and CCL2 binding to the glomerular endothelial glycocalyx appears differentially mediated by specific HS domains. Our findings may therefore contribute to the development of HS-based treatments for renal and possibly other inflammatory diseases specifically targeting chemokine-endothelial cell interactions. [ABSTRACT FROM AUTHOR]

Summary: We evaluated the value of VFA in the identification of vertebral fractures using a retrospective study and a meta-analysis. Performance of VFA was adequate in the meta-analysis although this was not demonstrated in our centre. We recommend checking the performance of VFA tools before exclusively relying on this tool. Introduction: Vertebral fractures are traditionally diagnosed using conventional radiographs of the spine. Vertebral fracture assessment (VFA) has been advocated as an alternative tool in the diagnosis of these fractures. Methods: We conducted a retrospective study as well as a systematic review and a meta-analysis to evaluate the performance of VFA compared to conventional spinal radiography in patients who had sustained a fracture and thus at risk for osteoporosis. A risk of bias analysis was also performed. Results: The diagnostic study included 542 patients (25% male) with fractures. The sensitivity of low-radiation VFA to detect a patient with a vertebral fracture ≥ Genant grade 2 was 0.77 and its specificity 0.80. Two hundred ninety-seven (55%) patients had ≥1 and 135(25%) ≥3 unevaluable vertebrae. The systematic review identified 16 studies including a total of 3238 subjects (19% male) with a mean age range of 45 to 74 years. Seven studies had a low risk of bias and 9 had an intermediate risk, mainly due to not consecutively including patients. The pooled sensitivity of VFA to detect a patient with a vertebral fracture ≥Genant grade 2 was 0.84 (95% CI, 0.72-0.92) and specificity 0.90 (95% CI, 0.84-0.94). Conclusions: Our findings from the meta-analysis suggest an adequate performance of VFA for the detection of vertebral fractures. However, we could not demonstrate these findings in our center, especially the specificity. Our data advocate caution with exclusively relying on VFA in the assessment of vertebral fractures without identifying performance and potential limitations of the technique. [ABSTRACT FROM AUTHOR]

Objective: Acromegaly is a rare disease caused by excess growth hormone (GH) production by the pituitary adenoma. The skeletal complications of GH and IGF-1 excess include increased bone turnover, increased cortical bone mass and deteriorated microarchitecture of trabecular bone, associated with a high risk of vertebral fractures in the presence of relatively normal bone mineral density (BMD). We aimed to evaluate tissue-level properties of bone using impact microindentation (IMI) in well-controlled patients with acromegaly aged ≥18 years compared to 44 controls from the outpatient clinic of the Centre for Bone Quality. Design and methods: In this cross-sectional study, bone material strength index (BMSi) was measured in 48 acromegaly patients and 44 controls with impact microindentation using the osteoprobe. Results: Mean age of acromegaly patients (54% male) was 60.2 years (range 37.9–76.5), and 60.5 years (range 39.8–78.6) in controls (50% male). Patients with acromegaly and control patients had comparable BMI (28.2 kg/m2 ± 4.7 vs 26.6 kg/m2 ± 4.3, P = 0.087) and comparable BMD at the lumbar spine (1.04 g/cm2 ± 0.21 vs 1.03 g/cm2 ± 0.13, P = 0.850) and at the femoral neck (0.84 g/cm2 ± 0.16 vs 0.80 g/cm2 ± 0.09, P = 0.246). BMSi was significantly lower in acromegaly patients than that in controls (79.4 ± 0.7 vs 83.2 ± 0.7; P < 0.001). Conclusion: Our data indicates that tissue-level properties of cortical bone are significantly altered in patients with controlled acromegaly after reversal of long-term exposure to pathologically high GH and IGF-1 levels. Our findings also suggest that methods other than DXA should be considered to evaluate bone fragility in patients with acromegaly. [ABSTRACT FROM AUTHOR]

Background: Coronary artery disease (CAD) is common in asymptomatic chronic dialysis patients and plays an important role in their poor survival. Early identification of these high-risk patients could improve treatment and reduce mortality. Abdominal aortic calcification (AAC) has previously been associated with CAD in autopsy studies. Since the AAC can be quantified easily using a lateral lumbar X-ray we hypothesized that the extent of AAC as assessed on a lateral lumbar X-ray might be predictive of the presence of significant CAD in dialysis patients.Methods: All patients currently enrolled in the ICD2 trial without a history of CABG or a PCI with stent implantation were included in this study. All patients underwent CT-angiography (CTA) and a lateral X-ray of the abdomen. AAC on X-ray was quantified using a previously validated scoring system whereupon the association between AAC and the presence of significant CAD was assessed.Results: A total of 90 patients were included in this study (71% male, 67 ± 7 years old). Forty-six patients were found to have significant CAD. AAC-score was significantly higher in patients with CAD (10.1 ± 4.9 vs 6.3 ± 4.6 (p < 0.05). Multivariate regression analysis revealed that AAC score is an independent predictor for the presence of CAD with a 1,2 fold higher risk per point increase (p < 0.01). The AAC score has a sensitivity of 85% and a specificity of 57% for the presence of significant CAD.Conclusion: This study shows that abdominal aortic calcification as assessed on a lateral lumbar X-ray is predictive for the presence of significant coronary artery disease in asymptomatic dialysis patients. This simple, non-invasive and cheap screening method could contribute to early identification of patients eligible for further screening of CAD.Trial Registration: NTR948 , registered 10-4-2007 ; ISRCTN20479861 , registered 2-5-2007. [ABSTRACT FROM AUTHOR]

Summary: In this study, we demonstrate a high prevalence of secondary factors in patients with a recent fracture independently of bone mineral density (BMD). Our results suggest that patients with a recent fracture should be screened for secondary factors for bone fragility regardless of BMD values. Introduction: Secondary factors for bone fragility are common in patients with osteoporosis who have sustained a fracture. The majority of fragility fractures occurs, however, in patients with osteopenia, and it is not known whether secondary factors may contribute to fracture risk in these patients or in those with normal BMD. Methods: Prospective cohort study evaluating the prevalence of secondary factors for bone fragility in consecutive patients referred to our fracture liaison service from June 2012 to June 2014 after a recent fracture. Results: Seven hundred nine patients were included, 201 (28 %) with osteoporosis, 391 (55 %) with osteopenia and 117 (17 %) with normal BMD. Mean age was 66.0 ± 9.8 years, 504 (73 %) were women and 390 (57 %) had one or more underlying secondary factor. Evaluation of clinical risk factors using fracture risk assessment tool (FRAX) identified 38 % of patients with ≥1 secondary factor including smoking (18 %), excessive alcohol use (12 %), glucocorticoid use (12 %) and rheumatoid arthritis (3 %). Laboratory investigations revealed chronic kidney disease in 13 %, monoclonal gammopathy also in 13 % and primary or secondary hyperparathyroidism in 1 and 6 %, respectively. Secondary factors for bone fragility were equally prevalent in patients with osteoporosis, osteopenia or normal BMD. Conclusions: Our findings demonstrate a high prevalence of secondary factors for bone fragility in patients who have sustained a recent fracture, independently of BMD. The significant number of documented factors, which were treatable, suggest that patients who sustained a fracture should be screened for secondary factors for bone fragility regardless of BMD values to optimise secondary fracture prevention. [ABSTRACT FROM AUTHOR]

Despite excellent short-term graft survival after renal transplantation, the long-term graft outcome remains compromised. It has become evident that a combination of sustained alloreactivity and calcineurin-inhibitor- (CNI-) related nephrotoxicity results in fibrosis and consequently dysfunction of the graft. New immunosuppressive regimens that can minimize or eliminate side effects, while maintaining efficacy, are required to improve long-term graft survival. In this perspective mesenchymal stromal cells (MSCs) are an interesting candidate, since MSCs have immunosuppressive and regenerative properties. The first clinical trials with MSCs in renal transplantation showed safety and feasibility and displayed promising results. Recently, the first phase II studies have been started. One of the most difficult and challenging aspects in those early phase trials is to define accurate endpoints that can measure safety and efficacy of MSC treatment. Since both graft losses and acute rejection rates declined, alternative surrogate markers such as renal function, histological findings, and immunological markers are used to measure efficacy and to provide mechanistic insight. In this review, we will discuss the current status of MSCs in renal transplantation with a focus on the endpoints used in the different experimental and clinical studies. [ABSTRACT FROM AUTHOR]

Aims Atrial fibrillation (AF) is common in dialysis patients and is associated with increased morbidity and mortality. The pathophysiology may be related to common risk factors for both AF and renal disease or to dialysis-specific factors. The purpose of this study was to determine whether and how AF onset relates to the dialysis procedure itself. Methods All dialysis patients enrolled in the implantable cardioverter defibrillator-2 (ICD-2) trial until January 2012, who were implanted with an ICD, were included in this study. Using the ICD remote monitoring function, the exact time of onset of all AF episodes was registered. Subsequently, this was linked to the timing of dialysis procedures. Results For the current study, a total of 40 patients were included, follow-up was 28±16 months, 80% male, 70±8 years old. A total of 428 episodes of AF were monitored in 14 patients. AF onset was more frequent on the days of haemodialysis (HD) (p<0.001) and specifically increased during the dialysis procedure itself ( p=0.04). Patients with AF had a larger left atrium (p<0.001) and a higher systolic blood pressure before and after HD (p<0.001). Conclusion This study provides insight in the exact timing of AF onset in relation to the dialysis procedure itself. In HD patients, AF occurred significantly more often on a dialysis day and especially during HD. These findings might help to elucidate some aspects of the pathophysiology of AF in dialysis patients and could facilitate early detection of AF in these high-risk patients. [ABSTRACT FROM AUTHOR]

Aims/hypothesis: Incretin-based therapies improve glycaemic control in patients with type 2 diabetes. In animal models of diabetes, glucagon-like peptide-1 receptor agonists (GLP-1RAs) increase beta cell mass. GLP-1RAs are also evaluated in non-diabetic individuals with obesity and cardiovascular disease. However, their effect on beta cell mass in normoglycaemic conditions is not clear. Here, we investigate the effects of the GLP-1RA liraglutide on beta cell mass and function in normoglycaemic mice. Methods: C57BL/6J mice were treated with the GLP-1RA liraglutide or PBS and fed a control or high-fat diet (HFD) for 1 or 6 weeks. Glucose and insulin tolerance tests were performed after 6 weeks. BrdU was given to label proliferating cells 1 week before the animals were killed. The pancreas was taken for either histology or islet isolation followed by a glucose-induced insulin-secretion test. Results: Treatment with liraglutide for 6 weeks led to increased insulin sensitivity and attenuation of HFD-induced insulin resistance. A reduction in beta cell mass was observed in liraglutide-treated control and HFD-fed mice at 6 weeks, and was associated with a lower beta cell proliferation rate after 1 week of treatment. A similar reduction in alpha cell mass occurred, resulting in an unchanged alpha to beta cell ratio. In contrast, acinar cell proliferation was increased. Finally, islets isolated from liraglutide-treated control mice had enhanced glucose-induced insulin secretion. Conclusions/interpretation: Our data show that GLP-1RA treatment in normoglycaemic mice leads to increases in insulin sensitivity and beta cell function that are associated with reduced beta cell mass to maintain normoglycaemia. [ABSTRACT FROM AUTHOR]

Endothelial cells in different microvascular segments of the kidney have diverse functions and exhibit differential responsiveness to disease stimuli. The responsible molecular mechanisms are largely unknown. We previously showed that during hemorrhagic shock, VCAM-1 protein was expressed primarily in extraglomerular compartments of the kidney, while E-selectin protein was highly induced in glomeruli only (van Meurs M, Wulfert FM, Knol AJ, de Haes A, Houwertjes M, Aarts LPHJ, Molema G. Shock 29: 291-299, 2008). Here, we investigated the molecular control of expression of these endothelial cell adhesion molecules in mouse models of renal inflammation. Microvascular segment-specific responses to the induction of anti-glomerular basement membrane (anti-GBM), glomerulonephritis and systemic TNF-α treatment showed that E-selectin expression was transcriptionally regulated, with high E-selectin mRNA and protein levels preferentially expressed in the glomerular compartment. In contrast, VCAM-1 mRNA expression was increased in both arterioles and glomeruli, while VCAM-1 protein expression was limited in the glomeruli. These high VCAM-1 mRNA/low VCAM-1 protein levels were accompanied by high local microRNA (miR)-126 and Egfl7 levels, as well as higher Ets1 levels compared with arteriolar expression levels. Using miR-reporter constructs, the functional activity of miR-126 in glomerular endothelial cells could be demonstrated. Moreover, in vivo knockdown of miR-126 function unleashed VCAM-1 protein expression in the glomeruli upon inflammatory challenge. These data imply that miR-126 has a major role in the segmental, heterogenic response of renal microvascular endothelial cells to systemic inflammatory stimuli. [ABSTRACT FROM AUTHOR]

South Asian immigrants in western societies exhibit a high burden of diabetes and subsequent vascular complications. Diabetic vascular complications are associated with vascular inflammation. We hypothesize that enhanced complement activation is involved. Therefore, levels of complement C3 and SC5b-9 – the soluble end product of complement activation – in a group of 200 South Asians were compared with an age- and sex-matched control group of native Caucasians. In addition, the association between complement levels and albuminuria, an indicator of renal damage and a cardiovascular risk marker, was assessed in the diabetic South Asian group. Compared with native Caucasians, South Asians had significantly higher levels of both serum C3 and plasma SC5b-9, even when only non-diabetic South Asians were considered. Diabetic South Asians had significantly higher C3 levels compared with non-diabetic South Asians. In diabetic South Asians, higher levels of SC5b-9 were associated with an increased prevalence of albuminuria (odds ratio 5·4, 95% confidence interval 1·8–15·8). These results suggest that enhanced complement activation is part of the unfavourable cardiovascular risk profile in South Asians. [ABSTRACT FROM AUTHOR]

Cardiovascular disease is the major cause of mortality in type 2 diabetes mellitus. The criteria for the selection of those asymptomatic patients with type 2 diabetes who should undergo cardiac screening and the therapeutic consequences of screening remain controversial. Non-invasive techniques as markers of atherosclerosis and myocardial ischaemia may aid risk stratification and the implementation of tailored therapy for the patient with type 2 diabetes. In the present article we review the literature on the implementation of non-invasive vascular tools and cardiac imaging techniques in this patient group. The value of these techniques as endpoints in clinical trials and as risk estimators in asymptomatic diabetic patients is discussed. Carotid intima–media thickness, arterial stiffness and flow-mediated dilation are abnormal long before the onset of type 2 diabetes. These vascular tools are therefore most likely to be useful for the identification of ‘at risk’ patients during the early stages of atherosclerotic disease. The additional value of these tools in risk stratification and tailored therapy in type 2 diabetes remains to be proven. Cardiac imaging techniques are more justified in individuals with a strong clinical suspicion of advanced coronary heart disease (CHD). Asymptomatic myocardial ischaemia can be detected by stress echocardiography and myocardial perfusion imaging. The more recently developed non-invasive multi-slice computed tomography angiography is recommended for exclusion of CHD, and can therefore be used to screen asymptomatic patients with type 2 diabetes, but has the associated disadvantages of high radiation exposure and costs. Therefore, we propose an algorithm for the screening of asymptomatic diabetic patients, the first step of which consists of coronary artery calcium score assessment and exercise ECG. [ABSTRACT FROM AUTHOR]

Generation of angiotensin II (Ang II) contributes to the pathogenesis of cardiovascular diseases. Owing to the existence of high levels of Ang II within the kidney, blockade of the intrarenal Ang II levels may be important since long term outcome seems not only to be related to blood pressure per se. This was a prospective, randomized, double-blind, placebo-controlled study, with crossover design. We examined in 13 patients with mild to moderate hypertension the specific systemic and renal blocking properties of two different Ang II receptor blockers during a wide range of Ang II concentrations, 24?h post dose. The effects were evaluated after 4 weeks treatment with candesartan cilexetil (16?mg OD), losartan (50?mg OD) and placebo using clearance techniques. Candesartan reduced the 24?h blood pressure better than losartan (138*/87±12/8 vs 145/89±12/7?mmHg,*P<0.05 vs losartan) and placebo. Despite the lower blood pressure, candesartan attenuated the Ang II-induced response on ERPF and RVR markedly better than losartan or placebo. The GFR decreased, as expected, with placebo, but remained stable with candesartan. The present study demonstrates that in hypertensive patients candesartan and to a lesser degree losartan are effective in blocking the systemic and renal effects of Ang II during a wide range of Ang II infusion rates. Interestingly, 24?h post dose, candesartan effectively diminished the change in ERPF as well as GFR. This sustained renal effect of candesartan may be of importance, especially in pathophysiological circumstances in which (high renal levels of) Ang II contributes to cardiovascular damage.Journal of Human Hypertension (2004) 18, 857-863. doi:10.1038/sj.jhh.1001769 Published online 9 September 2004 [ABSTRACT FROM AUTHOR]

Abstract Background Recent evidence indicates that remnant lipoprotein particles (RLPs) may play a role in atherosclerosis. Remnant lipoprotein particles have been suggested to be the most atherogenic particles among the triglyceride-rich lipoproteins. In particular, these triglyceride-rich particles were identified as an independent risk factor for cardiovascular diseases (CVD) in women. Postmenopausal hormone replacement therapy (HRT) beneficially affects lipid profile, although total triglyceride levels often increase. Evidence on the effects of HRT on RLPs is limited. We determined whether 3 months’ treatment of postmenopausal women with Tibolone or conjugated oestrogens combined with medroxyprogesterone acetate (CEE + MPA) affects RLP-cholesterol (RLP-C). Materials and methods One hundred and five healthy postmenopausal women were randomized to either 2·5 mg of Tibolone, 0·625 mg of CEE + 2·5 mg of MPA or placebo. At baseline and after 3 months the lipid profile was determined. For assessment of RLP-C we used an immunoseparation-based method. Results Treatment with CEE + MPA significantly reduced RLP-C (-0·03 mmol L-1 , P -value = 0·01) and appeared to increase triglycerides (0·15 mmol L-1 , P -value = 0·20) compared with placebo. Tibolone did not significantly change RLP-C (-0·01 mmol L-1 , P -value = 0·35) and significantly decreased triglycerides (-0·35 mmol L-1 , P -value = 0·004). Conclusions Treatment of postmenopausal women with conjugated oestrogens and medroxyprogesterone acetate reduced RLP-C, without a reduction in total triglycerides, whereas Tibolone did affect triglyceride levels, but not RLP-C. These observations may be relevant for explaining the effect of HRT on cardiovascular risk in healthy postmenopausal women. [ABSTRACT FROM AUTHOR]

Aims/hypothesis. Patients with diabetes are characterised by endothelial dysfunction and cardiovascular mortality. In particular endothelium-derived nitric oxide has emerged as a first line mechanism against atherosclerosis. Hyperglycaemia causes oxygen radical stress but has also been associated with endothelial nitric oxide synthase uncoupling, both lead to decreased nitric oxide-availability. We recently showed that folate reverses eNOS uncoupling in vitro. Therefore we hypothesise that folate improves endothelial function in Type II (non-insulin-dependent) diabetes mellitus in vivo. Methods. Using forearm plethysmography, we evaluated the effect of local, intra-arterial administration of 5-methyltetrahydrofolate (5-MTHF, the active form of folic acid, 1 µg/100 ml FAV/min) on forearm blood flow in 23 patients with Type II diabetes and 21 control subjects, matched for age, sex, blood pressure, body mass index, weight and smoking habits. Serotonin as a stimulator of nitric oxide-dependent vasodilation and sodium nitroprusside as a stimulator of endothelium-independent vasodilation were infused. Results. Serotonin-induced vasodilation was blunted (53±30 vs 102±66 M/C%, p<0.005) and nitroprusside-induced vasodilation was mildly reduced (275±146 vs 391±203 M/C%, p<0.05) in patients with Type II diabetes compared to control subjects. 5-MTHF improved nitric oxide-mediated vasodilation (from 53±30 to 88±59 M/C%, p<0.05) in patients with Type II diabetes mellitus. As expected, 5-MTHF had no effect on forearm blood flow in control subjects. Conclusion/interpretation. These data imply that folate can be used to improve nitric oxide status and to restore endothelial dysfunction in patients with Type II diabetes. Our results provide a strong rationale for the initiation of studies that investigate whether supplementation with folic acid prevents future cardiovascular events in this patient group. [ABSTRACT FROM AUTHOR]

The article examines the relationship between endothelial function and some common disorders in insulin resistance syndrome (IRS). The increased delivery of free fatty acids to the liver upregulates the production of very-low-density lipoprotein and increase their triglyceride content. The individual characteristics of IRS should be considered when considering improvement in endothelial function as a treatment target for the condition.

Abstract Background Intravenous iron supplementation is used widely in haemodialysis patients. However, nontransferrin-bound iron (NTBI), which increases after intravenous supplementation of ferric saccharate, has been suggested to act as a catalytic agent in oxygen radical formation in vitro and may thus contribute to endothelial impairment in vivo . Materials and methods In 20 healthy volunteers the effect of 100 mg ferric saccharate infusion was investigated. Vascular ultrasound was used to assess endothelium-dependent vasodilatation at baseline, and 10 and 240 min after ferric saccharate infusion. Whole blood was collected to measure NTBI and in vivo radical formation was assessed by electron spin resonance. A time-control study was performed using saline infusion. Results Infusion of ferric saccharate induces a greater than fourfold increase in NTBI, as well as a transient, significant (P < 0·01) reduction of flow-mediated dilatation 10 min after infusion of ferric saccharate, when compared with saline. The generation of superoxide in whole blood increased significantly 10 and 240 min after infusion of ferric saccharate by, respectively, 70 and 53%. Conclusions Iron infusion at a currently used therapeutic dose for intravenous iron supplementation leads to increased oxygen radical stress and acute endothelial dysfunction. [ABSTRACT FROM AUTHOR]

IRS is a complex disease consisting of a clustering of metabolic disorders, of which hyperglycaemia, hyper-insulinaemia and dyslipidaemia are the most important. Endothelial dysfunction plays an important role in the pathogenesis of atherosclerosis. The effects of hyperinsulinaemia seem to depend on lipidaemia and glycaemia. Hyperglycaemia and hyperlipidaemia have detrimental effects on endothelial function in the fasting as well as the postprandial states. In both situations, the generation of ROS and vasoactive molecules plays a major role in interfering with the atheroprotective endothelium-dependent NO system. Treatment of IRS in regard to endothelial function should be focused initially on lifestyle improvement, such as stopping smoking and eating a balanced diet containing antioxidant vitamins, folic-acid, L-arginine and long-chain omega-3 unsaturated FA. Strict glucose control has shown to improve endothelial function and decrease microvascular complications. However, macrovascular complications, in line with endothelial functional improvement, have so far been reduced only when treatment was focused on other characteristics of the IRS syndrome, in particular dyslipidaemia. Other relevant treatments include ACE inhibitors and thiazolidinediones, and probably tetrahydrobiopterin and folic acid supplementation. Future studies should address the effects of therapeutic neovascularization on endothelial dysfunction. [ABSTRACT FROM AUTHOR]

The relation between plasma lipoprotein composition and renal apolipoprotein deposition was studied in nephrotic rats in which stable renal function had been monitored for 7 months after a single low dose of adriamycin (ADR, 3 mg/kg). Proteinuria was observed 3 weeks after ADR and increased progressively up to about 0.5 g/day (versus 0.07 g/day in controls; < 0.001), while the creatinine clearance remained stable at about 80% of control values. Hypercholesterolaemia was observed 6 weeks after ADR, and increased progressively up to 7.0±1.0 mmol/l (versus 2.3±0.1 mmol/l in controls; <0.001). Cholesterol was primarily located in LDL2 and HDL2 lipoproteins. Plasma apolipoprotein (apo) A-I increased by more than 400% in the nephrotic rats (/><0.001). Apo B and apo E increased by about 60% (P<0.01), whereas apo A-IV remained unchanged. Focal sclerotic lesions in glomeruli had an incidence of 50±10% in ADR rats versus 2±1% in controls (P<0.001). Immunohistochemistry revealed apo A-I and apo A-IV in the visceral epithelium. Apo E immunoreactivity and lipid deposits were observed in focal glomerular sclerotic lesions of ADR rats. Neither apolipoproteins nor lipids were detected in glomeruli of controls. Proximal tubular localization of apolipoproteins was extensive for apo A-I, apo A-IV and apo E, but no differences were observed in tubular deposition of apolipoproteins between ADR and control rats. Chronic proteinuria induced by a single low dose of ADR in rats is a promising model to study the alleged pathogenetic role of hyperlipidaemia in relation to mesangial apolipoprotein E and lipid deposition in the deterioration of renal function and morphology in the nephrotic syndrome. [ABSTRACT FROM PUBLISHER]

Endothelium derived nitric oxide (NO) plays a major role in cardiovascular homeostasis. It has important anti-atherosclerotic properties which include regulation of vasomotor tone and vessel wall permeability, suppression of leucocyte adhesion to the endothelial surface, inhibition of platelet aggregation, and inhibition of vascular smooth muscle cell migration and proliferation. The important role of NO in the cardiovascular system is highlighted by key observations in animal models. Inhibition of endothelial NO synthase (eNOS), the enzyme that catalyses endothelial NO synthesis, accelerates atherogenesis. Similarly, genetic deletion of eNOS in mice leads to hypertension, defective vascular remodelling, vascular thrombosis, and enhanced leucocyte-endothelial cell interactions. In humans, all major cardiovascular risk factors, including hypercholesterolaemia, hypertension, diabetes, and smoking, have been associated with endothelial dysfunction, characterised by impaired NO bioavailability.

Despite excellent short-term graft survival after renal transplantation, the long-term graft outcome remains compromised. It has become evident that a combination of sustained alloreactivity and calcineurin-inhibitor- (CNI-) related nephrotoxicity results in fibrosis and consequently dysfunction of the graft. New immunosuppressive regimens that can minimize or eliminate side effects, while maintaining efficacy, are required to improve long-term graft survival. In this perspective mesenchymal stromal cells (MSCs) are an interesting candidate, since MSCs have immunosuppressive and regenerative properties. The first clinical trials with MSCs in renal transplantation showed safety and feasibility and displayed promising results. Recently, the first phase II studies have been started. One of the most difficult and challenging aspects in those early phase trials is to define accurate endpoints that can measure safety and efficacy of MSC treatment. Since both graft losses and acute rejection rates declined, alternative surrogate markers such as renal function, histological findings, and immunological markers are used to measure efficacy and to provide mechanistic insight. In this review, we will discuss the current status of MSCs in renal transplantation with a focus on the endpoints used in the different experimental and clinical studies. [ABSTRACT FROM AUTHOR]

The systemic pro-inflammatory state present in patients with rheumatoid arthritis (RA) accelerates the progression of atherosclerosis through chronic endothelial activation. Uncoupling of endothelial nitric oxide synthase plays a central role in the amplification of oxidative signalling pathways that chronically activate and, ultimately, injure the endothelium. Recent studies indicate that the resultant loss of endothelial integrity in patients with RA may also involve defects in the vascular regenerative potential provided by circulating endothelial progenitor cells (EPC). This is most likely the consequence of endothelial cell dysfunction in the bone marrow stroma, which hampers the mobilisation of these EPC to the circulation. In addition, mediators of systemic inflammation in RA can affect a second pathway of vascular regeneration. Under normal circumstances, myeloid CD14+ cells can adopt a pro-angiogenic phenotype that plays a key role in vascular remodelling and collateral formation. However, the chronic systemic inflammation observed in patients with RA may skew the differentiation of bone marrow and circulating CD14+ cells in such a way that these cells lose their capacity to support collateral formation, increasing the risk of cardiovascular disease. Taken together, in patients with RA, the impaired capacity of circulating cells to support vascular regeneration may comprise a novel pathway in the development of premature atherosclerosis. [ABSTRACT FROM PUBLISHER]