Calcification Of Blood Vessels Research Articles

Modeling and objectification of blood vessel calcification with using of multiregional segmentation

In a clinical practice of the angiography, the blood vessel analysis is substantially important mainly in a sense of an objectification and modeling of the pathological spots such as the blood vessel calcifications. An amount of the calcification is commonly just estimated by naked eyes; therefore, the automatic modeling may be beneficial in a context of an extraction of the blood vessel features well representing a level of the blood vessel deterioration. In this work, we have proposed a fully automatic software environment (BloodVessCalc) for processing the blood vessel images acquired by the CT (computer tomography). The main function of the SW is the multiregional image segmentation allowing for an extraction of the physiological blood vessel location from the calcification spots. This model offers the calcium score calculation in a form of amount of the calcification. In the last part of our analysis, the predictive intervals of the average value and median for calcium score are calculated.

Vitamin K‑dependent proteins involved in bone and cardiovascular health (Review).

In postmenopausal women and elderly men, bone density decreases with age and vascular calcification is aggravated. This condition is closely associated with vitamin K2 deficiency. A total of 17 different vitamin K-dependent proteins have been identified to date. Vitamin K-dependent proteins are located within the bone, heart and blood vessels. For instance, carboxylated osteocalcin is beneficial for bone and aids the deposition of calcium into the bone matrix. Carboxylated matrix Gla protein effectively protects blood vessels and may prevent calcification within the vascular wall. Furthermore, carboxylated Gla-rich protein has been reported to act as an inhibitor in the calcification of the cardiovascular system, while growth arrest-specific protein-6 protects endothelial cells and vascular smooth muscle cells, resists apoptosis and inhibits the calcification of blood vessels by inhibiting the apoptosis of vascular smooth muscle cells. In addition, periostin may promote the differentiation, aggregation, adhesion and proliferation of osteoblasts. Periostin also occurs in the heart and may be associated with the reconstruction of heart function. These vitamin K-dependent proteins may exert their functions following γ-carboxylation with vitamin K, and different vitamin K-dependent proteins may exhibit synergistic effects or antagonistic effects on each other. In the cardiovascular system with vitamin K antagonist supplement or vitamin K deficiency, calcification occurs in the endothelium of blood vessels and vascular smooth muscle cells are transformed into osteoblast-like cells, a phenomenon that resembles bone growth. Both the bone and cardiovascular system are closely associated during embryonic development. Thus, the present study hypothesized that embryonic developmental position and tissue calcification may have a certain association for the bone and the cardiovascular system. This review describes and briefly discusses several important vitamin K-dependent proteins that serve an important role in bone and the cardiovascular system. The results of the review suggest that the vascular calcification and osteogenic differentiation of vascular smooth muscle cells may be associated with the location of the bone and cardiovascular system during embryonic development.

Calcium Crystal Deposition in Patients of Knee Osteoarthritis (OA) Using Ultrasonography and Dual Energy Computed Tomography

Purpose: Calcium Crystal Deposition is common in OA knee. This study looked for Calcium crystal deposition in Osteoarthritis knee by different methodologies which included Dual Energy Computed Tomography, Ultrasonography, Digital X-ray and Synovial fluid examination by Polarized light microscopy. Methods: 32 patients of knee OA Kellgren and Lawrence grade II and III (Sex ratio F = 21 M = 11, mean age 59.9, Range 43–76 years, mean BMI 26.7, Range BMI 16.9–40.1)were enrolled in this study. Patients with Synovial Chondromatosis were excluded. X-ray of knees was done in weight bearing position. Ultrasonography of knee joints was done by using multifrequency linear array transducer on Logiq E, GE Medical Systems Ultrasound, B mode gray scale with dynamic range of 40–50 dB, GS frequency of 11–13 MHz and GS gain of 60 dB. Knee joint was kept in maximum flexion for femoral condyle cartilage and 45 degree flexion for menisci, patellar tendon, collateral ligaments and supra patellar soft tissues. Presence of hyperechoic aggregates, intra cartilage calcifications were looked for in above mentioned sites. Femoral condylar cartilage was also looked for presence of Double / Triple contour sign. Synovial effusion was tapped in 9 patients for microscopic examination by polarized light microscopy for CPP crystals. 17 patients agreed for Dual energy computed tomography (DECT) and their right Knees were scanned for any calcifications in the joint other than the bones and Osteophytes. Results: Of X-rays of knees of 32 patients, 32 (100%) showed osteophytes, 14 (43.8%) cartilage calcification, 5 (15.6%) meniscal calcification, 16 (50%) soft tissue calcification, 1 (3.1%) blood vessel calcification, 27 (82.3%) joint space narrowing and 2 (6.3%) erosions. Ultrasonograpic finding showed osteophytes in 30 (93.8%), cartilage calcification in 24 (75%) (Double / triple contour sign in 5 (15.6%)), meniscal calcification in 30 (93.8%) soft tissue calcifications in 3 (9.4%) and erosions in 14 (43.8%). DECT images of 17 patients were observed in 17 knees in 25 sub regions and showed calcification within and around the tibio-femoral and patello-femoral joints in 15 (88.2%) knees. 41.2% had hyaline cartilage, 78.6% cruciate ligaments, 23.5% medial collateral ligament and 5.9% joint capsule calcifications. Nine patients had inflammation in the knee joint. These patients were subjected to Synovial Fluid aspiration. 4 out of these 9 showed presence of CPP crystals. Out of these 9 patients, 4 patients had meniscal calcification, 8 patients had cruciate ligament calcification, all 9 patients had cartilage calcification, and none had capsule calcification. Conclusions: Nearly all patients with KL grade II/III knee OA had calcium deposits in the knee. DECT is a more useful tool for describing calcium crystal deposition in the knee as compared to X-ray, ultrasonography and synovial fluid examination. Calcium crystal deposition by DECT was seen in 15 (88.2%) patients. All modalities are complementary to each other. While USG was better than X-Rays to show Meniscal and Cartilage calcifications DECT was particularly useful to detect Cruciate Ligament Calcifications.

Abstract P257: Between-pedigree Genome-wide Linkage Screen Identifies a Locus on Chromosome 9 Influencing Coronary Artery Calcification in the Family Heart Study

Coronary artery calcification (CAC) is the buildup of calcium deposits in the arteries leading to the heart, and is an indicator of atherosclerosis. CAC is known to have a genetic component. To identify the genes underlying CAC, a genome-wide linkage screen was performed in the Family Heart Study. There are two established loci influencing CAC identified by genome-wide association scans, at chromosome 9p21 and 6p24. However, there may be rare variants on haplotypes in the population that influence CAC. These would not be able to be identified by genome-wide association scans, but linkage scans could detect them. From the study, 2,687 individuals of European descent from 508 pedigrees with CAC scores were genotyped on the Illumina Human 1M-DuoV3 single nucleotide polymorphisms (SNP) array. CAC scores were determined by cardiac CT scan and adjusted for age, sex, and principal components before analysis. Using 484,358 common SNPs (minor allele frequency greater than 5%), common ancestry across the genome was determined for all pairs of individuals in the study. A segment of the genome was considered to be inherited from a common ancestor (identical-by-descent, IBD) if it contained more than 1,000 matching SNP genotypes over a length of at least one megabase. To test the influence of IBD at a locus on CAC, a linear mixed effects model was fit, including random effects to account for covariance due to relatedness and IBD states at each locus. All pedigrees were considered jointly in the model. Statistical significance was determined by comparing this model to one without IBD covariance via the likelihood ratio test. This model was evaluated approximately every megabase across all 22 pairs of autosomes. Since IBD states are determined solely by dense genotype data, IBD can be detected both within and between pedigrees in the study. This allows the inclusion covariance due to IBD in individuals in different pedigrees. If there is a haplotype shared across pedigrees, power to detect linkage is increased. CAC was found to have a narrow-sense heritability of 37.4% in this sample. Significant evidence of linkage was encountered at rs13293430 (chromosome 9, 31,050,747bp, LOD=3.042). When considering IBD between pedigrees, 914 pairs of individuals from different pedigrees were IBD at this position. This locus is near DDX58. Mutations in DDX58 cause Singleton-Merton syndrome, a disease characterized by calcification of blood vessels, making it an intriguing candidate gene for influence on CAC.

Interventions for metabolic bone disease in children with chronic kidney disease.

Bone disease is common in children with chronic kidney disease (CKD) and when untreated may result in bone deformities, bone pain, fractures and reduced growth rates. This is an update of a review first published in 2010. This review aimed to examine the benefits (improved growth rates, reduced risk of bone fractures and deformities, reduction in PTH levels) and harms (hypercalcaemia, blood vessel calcification, deterioration in kidney function) of interventions (including vitamin D preparations and phosphate binders) for the prevention and treatment of metabolic bone disease in children with CKD. We searched the Cochrane Kidney and Transplant Specialised Register to 8 September 2015 through contact with the Trial's Search Co-ordinator using search terms relevant for this review. We included randomised controlled trials (RCTs) comparing different interventions used to prevent or treat bone disease in children with CKD stages 2 to 5D. Data were assessed for study eligibility, risk of bias and extracted independently by two authors. Results were reported as risk ratios (RR) or risk differences (RD) with 95% confidence intervals (CI) for dichotomous outcomes. For continuous outcomes the mean difference (MD) or standardised mean difference (SMD) with 95% confidence intervals (CI) was used. Statistical analyses were performed using the random-effects model. This review included 18 studies (576 children); three new studies were added for this update. Adequate sequence generation and allocation concealment were reported in 12 and 11 studies respectively. Only four studies reported blinding of children, investigators or outcome assessors. Nine studies were at low risk of attrition bias and 12 studies were at low risk of selective reporting bias.Eight different interventions were compared. Two studies compared intraperitoneal (IP) with oral calcitriol. PTH levels were significantly lower with IP compared with oral calcitriol (1 study: MD -501.00 pg/mL, 95% CI -721.54 to -280.46) but the number of children with abnormal bone histology did not differ between treatments. Three studies compared intermittent with daily oral calcitriol. The change in mean height SDS (1 study: MD 0.13, 95% CI -0.22 to 0.48) and the percentage fall in parathyroid hormone (PTH) levels at eight weeks (1 study: MD -5.50%, 95% CI -32.37 to 21.37) and 12 months (1 study: MD -6.00% 95% CI -25.27 to 13.27) did not differ between treatments.Four studies compared active vitamin D preparations (calcitriol, paricalcitol, 1α-hydroxyvitamin D) with placebo or no specific treatment. One study reported vitamin D preparations significantly reduced PTH levels (-55.00 pmol/L, 95% CI -83.03 to -26.97). There was no significant difference in hypercalcaemia risk with vitamin D preparations compared with placebo or no specific treatment (4 studies, 103 children: RD 0.08 mg/dL, 95% CI -0.08 to 0.24). However, there was heterogeneity (I(2) = 55%) with one study showing a significantly greater risk of hypercalcaemia with intravenous (IV) calcitriol administration. Two studies (97 children) compared calcitriol with other vitamin D preparations and both found no significant differences in growth between preparations.Two studies compared ergocalciferol in patients with CKD and vitamin D deficiency. Elevated PTH levels developed significantly later in ergocalciferol treated children (1 study: hazard ratio 0.30, 95% CI 0.09 to 0.93) though the number with elevated PTH levels did not differ between groups (1 study, 40 children: RR 0.33, 95% CI 0.11 to 1.05).Two studies compared calcium carbonate with aluminium hydroxide as phosphate binders. One study (17 children: MD -0.86 SDS, 95% CI -2.24 to 0.52) reported no significant difference in mean final height SDS between treatments. Three studies compared sevelamer with calcium-containing phosphate binders. There were no significant differences in the final calcium, phosphorus or PTH levels between binders. More episodes of hypercalcaemia occurred with calcium-containing binders. One study reported no significant differences between calcitriol and doxercalciferol in bone histology or biochemical parameters. Bone disease, assessed by changes in PTH levels, is improved by all vitamin D preparations. However, no consistent differences between routes of administration, frequencies of dosing or vitamin D preparations were demonstrated. Although fewer episodes of high calcium levels occurred with the non-calcium-containing phosphate binder, sevelamer, compared with calcium-containing binders, there were no differences in serum phosphorus and calcium overall and phosphorus values were reduced to similar extents. All studies were small with few data available on patient-centred outcomes (growth, bone deformities) and limited data on biochemical parameters or bone histology resulting in considerable imprecision of results thus limiting the applicability to the care of children with CKD.

Detection and characterization of mineralo-organic nanoparticles in human kidneys.

Ectopic calcification is associated with various human diseases, including atherosclerosis, cancer, chronic kidney disease, and diabetes mellitus. Although mineral nanoparticles have been detected in calcified blood vessels, the nature and role of these particles in the human body remain unclear. Here we show for the first time that human kidney tissues obtained from end-stage chronic kidney disease or renal cancer patients contain round, multilamellar mineral particles of 50 to 1,500 nm, whereas no particles are observed in healthy controls. The mineral particles are found mainly in the extracellular matrix surrounding the convoluted tubules, collecting ducts and loops of Henle as well as within the cytoplasm of tubule-delineating cells, and consist of polycrystalline calcium phosphate similar to the mineral found in bones and ectopic calcifications. The kidney mineral nanoparticles contain several serum proteins that inhibit ectopic calcification in body fluids, including albumin, fetuin-A, and apolipoprotein A1. Since the mineralo-organic nanoparticles are found not only within calcified deposits but also in areas devoid of microscopic calcifications, our observations indicate that the nanoparticles may represent precursors of calcification and renal stones in humans.

Peripheral arterial disease: diagnostic challenges and how photoplethysmography may help.

Peripheral arterial disease (PAD) affects approximately 20% of patients aged ≥60 years.1 A GP with an average list size of 1800 patients can expect to have 50–60 patients with PAD. Ankle-brachial pressure index (ABPI), which is the ratio of the ankle to brachial systolic pressure measured by sphygmomanometer and hand-held Doppler ultrasound probe, is used to assess PAD in general practice. ABPI has been shown to have a sensitivity of 95% and specificity of 99% compared to angiographic imaging,2 however it is relatively time-consuming and requires adequately trained staff. There are limitations with ABPI in patients with diabetes, renal disease, and older people where an underestimation of disease can occur with a falsely high ratio due to the presence of incompressible calcified blood vessels. #### Clinical Question Can peripheral arterial disease be accurately diagnosed in general practice? The characteristic clinical diagnostic feature of PAD is intermittent claudication (IC), muscle pain brought on by exercise, relieved by rest and experienced in the calf with femoropopliteal disease and in the buttock, hip or thigh with aortoiliac disease. However it is sometimes difficult to distinguish clinically between claudication and leg pain from other causes such as spinal stenosis. ### ABPI methodology The first problem we face is that a significant proportion of patients in general practice who are arteriopaths are asymptomatic and ABPI has …

Structural Heterogenity of Intraluminal Content of The Prostate: A Histochemical and Ultrastructural Study

Intraluminal contents of benign and malignant prostatic tissue are associated with varying forms of acellular structures. These include corpora amylacea, prostatic calculi, and prostatic crystalloids. There are relatively few microscopy studies about the characterization of intraluminal structures from benign and malignant prostatic glands and little is known about their chemical composition. In the present study, we used a combination of special histochemical methods, immunohistochemistry, and transmission electron microscopy to characterize intraluminal contents of benign and malignant prostate glands. The study was done on 33 radical prostatectomy and four transurethral resections of prostate specimens. Histochemical methods such as von Kossa, autometallography (AMG), as well as PSA immunohistochemistry and transmission electron microscopy were performed to characterize intraluminal contents of benign and malignant prostate glands. Von Kossa staining was observed in acellular structures, corpora amylacea, prostatic calculi, and calcified blood vessels. AMG staining was observed in the lumen of small glands, in the epithelium lining prostate glands, and corpora amylacea. PSA staining showed prostatic glands with both positive and negative corpora amylacea and epithelial cells. Ultrastructural observation revealed the presence of a variety of highly heterogeneous aggregates composed of fibrillar elements that were similar to those of amyloid.

Hyperphosphatemia. The hidden killer in chronic kidney disease.

Hyperphosphatemia is a major cause of morbidity and mortality in patients with chronic kidney disease. The association between hyperphosphatemia and increased risk of death from cardiovascular disease/vascular calcification has been well established for a long time. This review explores the new aspects of pathogenesis of vascular calcification, as demonstrated by recent advances showing a recognized regulating role of phosphorus in vascular smooth muscle cell calcification. This novel mechanism may help in finding a new pharmacological therapy to reduce, or prevent blood vessel calcification. Furthermore, recent experimental and clinical studies involved in the treatment of hyperphosphatemia are reviewed in this article.

Apoptosis and calcification of vascular endothelial cell under hyperhomocysteinemia.

In recent years, it is found that increase in Hcy level in blood can directly or indirectly cause vascular endothelial cell injury and induce vascular calcification. However, the mechanism of vascular endothelial cell injury and vascular calcification has not been studied thoroughly. This paper carried out experiment for research aiming at discussing the effect and action mechanism of Hhcy on endothelial cells and vascular calcification. Firstly, human umbilical vein endothelial cells (HUVECs) were cultured and then intervened by Hcy of different concentrations (0, 0.01, 0.1, 1.0, 3.0, 5.0mmol/L) and at different action time (3, 6, 12, 24h). Then apoptosis rate and reactive oxygen were detected by flow cytometry. At the same time, the model for the culture of rat vascular calcification was set up and induced into Hhcy so as to detect the total plasma Hcy level and judge vascular calcification degree. The results showed that with the increase in Hcy concentration and extension of action period, the apoptosis rate and generation of reactive oxygen of HUVECs all significantly increased, and the differences were all statistically significant (P<0.01). In animal calcification model, mass of black particle deposition was seen after Von Kossa staining of rat vessels in calcification group. Compared with the control group, the vascular calcium content, alkaline phosphatase activity and osteocalcin content in calcification group all increased (P<0.01). The content of plasma lipid conjugated olefine from highest to lowest wasas follows: calcification plus homoetheionin, homoetheionin, and calcification group. There was no significant difference between the calcification group and control group. All these findings suggested that Hcy could induce the apoptosis of endothelial cells and its effect degree depended on its concentration and action period; Hhcy could promote the calcification of blood vessels, and its mechanism might relate with the strengthening of lipid peroxidation. The above results leave great benefits on clinical prevention works.

Calcified structures associated with human skeletal remains: Possible atherosclerosis affecting the population buried at Amara West, Sudan (1300–800 BC)

Today, cardiovascular diseases (CVDs) are the leading cause of death worldwide. Atherosclerosis, the thickening of the artery wall due to accumulating lipids, is one of the major causes. Generally assumed to be a disease of modern life-style related factors (smoking, obesity, hypertension), its history and epidemiology in the past are virtually unknown. Research on mummies from various geographic locations, time periods and socioeconomic backgrounds has revealed conclusive, albeit scant, evidence that atherosclerosis also affected past human populations. Little is known about the morphology of calcified atherosclerotic plaques that may be associated with human skeletal remains. Therefore, direct evidence of atherosclerosis from skeletal remains is largely absent. This paper presents five possible examples of calcified blood vessels which may represent atherosclerosis recovered from burials at Amara West, Sudan (1300–800BC) and reviews other potential causes of arterial calcification. Calcifications were recovered from the chest area of three middle-adult individuals as well as from the abdominal area and alongside the femur of two more. Based on morphology, anatomical location, scanning electron microscopy and radiography, they are probably calcified arterial plaques. These findings are unique in the bioarchaeological record and indicate that people have experienced atherosclerosis for at least 3000 years.

In This Issue

HomeCirculation ResearchVol. 114, No. 7In This Issue Free AccessResearch ArticlePDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessResearch ArticlePDF/EPUBIn This Issue Ruth Williams Ruth WilliamsRuth Williams Search for more papers by this author Originally published28 Mar 2014https://doi.org/10.1161/RES.0000000000000020Circulation Research. 2014;114:1069Activated Platelet Targeted Fibrinolysis (p 1083)Download figureDownload PowerPointWang et al develop a low dose, low risk thrombolytic fusion protein for busting blood clots.Thrombolytic drugs such as tissue plasminogen activator are used to breakdown blood clots in the event of a heart attack or stroke, but because these drugs act systemically, they carry a high risk of causing excessive bleeding. If such drugs could be targeted specifically to blood clots, it would both increase their potency and decrease their associated bleeding risk. Wang and colleagues therefore created a new fusion protein between a plasminogen activator and an antibody that specifically targets clot-initiating activated platelets. They found that the fusion protein inhibited platelet aggregation in culture, and maintained blood flow velocity more effectively than an equivalent dose of commercial untargeted plasminogen activator when given to mice that were induced to develop thrombi. A high dose of the commercial drug gave results similar to the fusion protein, but it dramatically increased bleeding times following tail transections. Based on the ability to the fusion protein to breakdown clots at a lower dose, without drastically increasing bleeding risk, Wang and colleagues suggest that such antibody targeted clot-busting strategies might be used not only as thrombolytic agents but also as a preventative treatment in patients at high risk of thrombosis.O-GlcNAcylation and Vascular Calcification (p 1094)Download figureDownload PowerPointHeath et al find a causative link between O-GlcNAcylation and vascular calcification in diabetes.Vascular calcification is a common complication of diabetes and is associated with an increased risk of life-threatening cardiovascular events. Determining how calcification occurs and how to prevent it are therefore major goals of current diabetes research. Previous work has shown that proteins in the calcified blood vessels of patients with diabetes exhibit high levels of a post-translational modification called O-GlcNAcylation, in which N-acetylglucosamine moieties are linked to serine or threonine residues. But whether and how O-GlcNAcylation might cause calcification was unknown. Heath and colleagues, therefore, experimentally induced O-GlcNAcylation in mouse vascular smooth muscle cells (VSMCs) and in the blood vessels of diabetic mice and found that both were subject to increased calcification. Furthermore, they found that O-GlcNAcylation directly modified AKT, a protein kinase known to promote VSMC calcification. Mutational analysis revealed that the O-GlcNAcylation occurred on threonine 430 and 479 of AKT, which in turn promoted phosphorylation of serine 473; thereby enhancing AKT activity and activating the downstream calcification pathway. Blocking O-GlcNAcylation of AKT may therefore be a novel strategy for preventing vessel calcification in diabetes, say the authors.CPVT CaM Mutants and RyR2 Channels (p 1114)Download figureDownload PowerPointHwang et al investigate how different calmodulin mutants affect ryanodine receptor 2 calcium channels.Calmodulin (CaM) is a calcium-binding protein that regulates several cell functions, including calcium sensing and calcium release from intracellular stores. Mutations in the CaM gene have been linked to cardiac arrhythmia, although different mutations cause different types of irregularity. For example, two specific CaM mutants, associated with stress-induced polymorphic ventricular tachycardia, are referred to as CPVT-CaMs, while another three associated with long QT syndrome are referred to as LQTS-CaMs. In the heart, wild type CaM binds to and inhibits the sarcoplasmic reticulum calcium channel ryanodine receptor 2 (RyR2), reducing the frequency of calcium release. Hwang and colleagues have now discovered that CPVT-CaMs bind with higher efficiency to RyR2 and that they increase rather than reduce the frequency of calcium release. LQTS-CaMs on the other hand tend not to affect RyR2 function, suggesting an alternative mechanism of arrhythmogenesis. CPVT-CaMs dysregulated RyR2 even in the presence of an 8-fold excess of wild type protein. This potency of the mutant proteins explains their dominant phenotypic effects. Altogether the results explain the distinct types of arrhythmia caused by the different CaM mutations, which in turn may help in the development of appropriate treatment strategies for carriers of the mutations. Previous Back to top Next FiguresReferencesRelatedDetails March 28, 2014Vol 114, Issue 7 Advertisement Article InformationMetrics © 2014 American Heart Association, Inc.https://doi.org/10.1161/RES.0000000000000020 Originally publishedMarch 28, 2014 PDF download Advertisement

Peptides of Matrix Gla Protein Inhibit Nucleation and Growth of Hydroxyapatite and Calcium Oxalate Monohydrate Crystals

Matrix Gla protein (MGP) is a phosphorylated and γ-carboxylated protein that has been shown to prevent the deposition of hydroxyapatite crystals in the walls of blood vessels. MGP is also expressed in kidney and may inhibit the formation of kidney stones, which mainly consist of another crystalline phase, calcium oxalate monohydrate. To determine the mechanism by which MGP prevents soft-tissue calcification, we have synthesized peptides corresponding to the phosphorylated and γ-carboxylated sequences of human MGP in both post-translationally modified and non-modified forms. The effects of these peptides on hydroxyapatite formation and calcium oxalate crystallization were quantified using dynamic light scattering and scanning electron microscopy, respectively. Peptides YGlapS (MGP1-14: YγEpSHEpSMEpSYELNP), YEpS (YEpSHEpSMEpSYELNP), YGlaS (YγESHESMESYELNP) and SK-Gla (MGP43-56: SKPVHγELNRγEACDD) inhibited formation of hydroxyapatite in order of potency YGlapS > YEpS > YGlaS > SK-Gla. The effects of YGlapS, YEpS and YGlaS on hydroxyapatite formation were on both crystal nucleation and growth; the effect of SK-Gla was on nucleation. YGlapS and YEpS significantly inhibited the growth of calcium oxalate monohydrate crystals, while simultaneously promoting the formation of calcium oxalate dihydrate. The effects of these phosphopeptides on calcium oxalate monohydrate formation were on growth of crystals rather than nucleation. We have shown that the use of dynamic light scattering allows inhibitors of hydroxyapatite nucleation and growth to be distinguished. We have also demonstrated for the first time that MGP peptides inhibit the formation of calcium oxalate monohydrate. Based on the latter finding, we propose that MGP function not only to prevent blood-vessel calcification but also to inhibit stone formation in kidney.

Nalp3 inflammasome is activated and required for vascular smooth muscle cell calcification

The calcification of blood vessels correlates with increased morbidity and mortality in patients with atherosclerosis, diabetes, and end-stage kidney disease. Increased inflammasome activation has been shown to play an important role in the pathogenesis of atherosclerosis. However, the contribution of inflammasome activation on the development of vascular calcification has not been investigated. β-Glycerophosphate (β-GP) was used as a procedure to induce extensive artery calcification in primary vascular smooth muscle cells (VSMCs). Analysis of the levels of Nalp3 inflammasome complex was performed by quantitative real-time PCR and western blotting. The effect of Nalp3 deficiency on VSMC calcification was examined after transfecting Nalp3 siRNA into cultured VSMCs. We demonstrated for the first time that the mRNA levels of Nalp3 inflammasome complex including Nalp3, ASC and caspase1 were upregulated in calcifying VSMCs, resulting in increased IL-1β secretion. Inhibition of inflammasome activation by Nalp3 RNA interference reduced IL-1β secretion and inhibited VSMC calcification. Further analysis of clinical popliteal artery specimens showed an upregulation of inflammasome complex mRNA levels (4/5) and caspase1 activity (5/5) compared with their non-calcified adjacent tissues, indicating that Nalp3 inflammasome was tightly correlated with arterial calcification disease. Our findings indicate that activation of the Nalp3-mediated inflammatory response pathway is an important venue associated with host response and pathogenesis of VSMC calcification.

Acute Abdominal Pain in an End Stage Renal Disease Patient

An 81-year-old female with history of end stage renal disease on hemodialysis presented with worsening of abdominal pain of 2 days’ duration. The pain started as a dull ache over the lower abdomen 2 months earlier, diffuse but especially prominent over the lower quadrant, and was unrelieved by analgesic medications. On physical examination her whole abdomen was diffusely tender, but the lower quadrant was extremely tender with palpable nodular lesions. Her laboratory work showed a normal amylase and lipase level along with a white cell count of 13.5K/CUMM (3.5–10.6 K/CUMM), calcium of 10.6 mg/dL (8.2–10.6 mg/dL), phosphorus of 5.9 mg/dL (2.3–5.0 mg/dL) and intact PTH 880 pg/mL (18–86 pg/mL). She had a computed tomography of the abdomen and pelvis (Figure), which showed multiple soft tissue densities in the lower quadrant of anterior abdominal wall, while the ultrasound of her abdomen (Video) revealed subcutaneous nodule with internal septations and calcified vessels. Both these findings in the setting of end stage renal disease were consistent with calciphylaxis, a rare, and often fatal, complication. Although ulceration is considered a hallmark of calciphylaxis, it can also present as non-ulcerative nodular lesions, as in our patient.1 Various putative risk factors for calciphylaxis include obesity; serum aluminum is greater than 25 ng/mL and serum calcium phosphorus product more than 70.2 Treatment is multifaceted, including strict control of secondary hyperparathyroidism, maintenance of calcium phosphate product below 55 mg2/dL2 using non-calcium containing phosphate binders, administration of intravenous sodium thiosulfate with each dialysis (6–12 weeks), and a trial of prednisone tapered over a period of a couple of weeks.1 With the above treatment, she had significant improvement of symptoms. Our case highlights the need for emergency physicians to be cognizant of this life-threatening complication in end stage renal disease patients and of the fact that calciphylaxis has different modes of presentation, among which is acute abdominal pain. Figure. Computed tomography of the abdomen and pelvis without contrast showing multiple soft tissue densities in the anterior abdominal wall (A). Calcification of blood vessels within the abdomen and pelvis was also noted (B). Video. Ultrasound of abdomen revealing subcutaneous nodule. Click here to view.(8.9M, mpg)

An unusual site for calciphylaxis: a case report

Background: Calciphylaxis is a rare condition characterized by calcification of the tunica media of small arteries with or without endovascular fibrosis, extravascular calcification and vascular thrombosis, leading to tissue ischemia and hence necrosis of tissues supplied by respective vessel. Case report: An 83-year-old lady presented with a 2-week history of rapidly progressing painful necrotic vulval lesion. This patient was being treated medically with bisphosphonates for mild hypercalcaemia secondary to a parathyroid adenoma. The diagnosis of calciphylaxis was made by biopsy of lesion, revealing extensive necrotic areas and multiple abscesses with numerous thrombosed and calcified blood vessels. Conclusions: This case shows an unusual presentation of calciphylaxis, in a patient with primary hyperparathyroidism, in the absence of end stage renal failure. The pathogenesis of the condition is still relatively unknown. Particularly of note in this case is the presentation of the lesion 9 months after the start of treatment with bisphosphonate after the relative decrease of serum parathyroid levels and serum calcium levels. This leads to the question of initiation of the pathology – did the bisphosphonate treatment have an input in initiation of the lesion? The case under review adds a new differential diagnosis to necrotic vulval lesions, other than malignancy.

The justification for application and development trends of non-conventional rodenticides in protection of alfalfa from rodents

This paper presents the harmful rodents in alfalfa in Serbia in the first decade of this century. We also review the products registered and assessed the efficiency of conventional (acute) rodenticides, anticoagulant and rodenticides based on environmentally friendly active ingredients. In addition to anticoagulants of second generation, whose mechanism of action is based on a synthesis of the factors preventing blood coagulation, in the latest of the eighties, and in early of nineties introduced products based on vitamin D3-cholecalciferol. Their mechanism of action is based on the mobilization of calcium from bone and tissue and calcification of blood vessels, kidney, liver, heart muscle leading to delays in the work of these bodies. The last decade of the last century have been recorded and products based on trace element selenium (Se), the mechanism of action is based on the replacement of thiol functional enzymes SS groups. Also presents the possibility of application of ecological cellulose product in the field. In the world, so far, cellulose based rodenticides are only registered in municipal buildings. Its mechanism of action is based on interference with the absorption of water leading to dehydration in rodents. Rodents do not develop resistance to products based on vitamin D3 and selenium, a cellulose product is favourable toxicological and eco-toxicological point.

Cochrane review: Interventions for bone disease in children with chronic kidney disease

AbstractBackgroundBone disease is common in children with chronic kidney disease (CKD) and when untreated may result in bone deformities, bone pain, fractures and reduced growth rates.ObjectivesTo investigate the benefits and harms of interventions for preventing and treating bone disease in children with CKD.Search strategyThe Cochrane Renal Group's specialised register, the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, reference lists and abstracts were searched without language restriction.Selection criteriaRandomised controlled trials (RCTs) comparing different interventions used to prevent or treat bone disease in children with CKD stages 2‐5D compared with placebo, no treatment or other agents were included. Studies examining different routes or frequency of treatment were also included.Data collection and analysisData were extracted by two authors. The random‐effects model was used and results were reported as risk ratios or risk differences for dichotomous outcomes and mean differences for continuous outcomes with 95% confidence intervals.Main resultsFifteen RCTs (369 children) were identified. Compared with oral calcitriol, intraperitoneal calcitriol significantly reduced the level of serum parathyroid hormone (PTH) but there were no significant differences in bone histology or other biochemical measures (2 RCTs). There were no significant differences detected in growth, PTH, serum calcium or phosphorus between daily versus intermittent calcitriol (3 RCTs). Vitamin D therapy significantly reduced PTH levels compared with placebo or no treatment. The number of children with hypercalcaemia did not differ significantly between groups (4 RCTs). No significant differences were detected in growth rates, bone histology or biochemical parameters between calcitriol and either dihydrotachysterol or ergocalciferol (2 RCTs). Though fewer episodes of hypercalcaemia were reported with sevelamer, no significant differences were detected in serum calcium, phosphorus and PTH levels between calcium‐containing phosphate binders and either aluminium hydroxide or sevelamer (4 RCTs).Authors' conclusionsBone disease, assessed by changes in PTH levels, is improved by all vitamin D preparations. However no consistent differences between routes of administration, frequencies of dosing or vitamin D preparations have been demonstrated. Though fewer episodes of high calcium levels occurred with the non calcium‐containing binder, sevelamer, compared with calcium‐containing binders, there were no differences in serum phosphorus and calcium overall and phosphorus values were reduced to similar extents. All RCTs were small with few data available on patient‐centred outcomes (growth, bone deformities) and limited data on biochemical parameters resulting in considerable imprecision of results thus limiting the applicability to care of children with CKD.Plain Language SummaryInterventions for bone disease in children with chronic kidney diseaseChronic kidney disease (CKD) resulting in reduced kidney function and the need for dialysis and kidney transplant is associated with abnormalities in blood calcium and phosphorus levels leading to high levels of the parathyroid hormone (PTH) and to bone disease. This may result in bone deformities, bone pain, fractures and reduced growth rates. Commonly used treatments (Vitamin D compounds and phosphate binders) aim to prevent or correct these outcomes. However these treatments may raise levels of blood calcium, allow calcium and phosphorus deposition in blood vessels and lead to early cardiovascular disease, which is known to be a problem in adults with CKD. This review identified only 15 small RCTs involving 369 children comparing different vitamin D compounds, different routes and frequencies of administration of vitamin D compounds and different phosphate binders. Only five RCTs reported on growth rates and no differences were detected between treatments. Renal bone disease, as assessed by changes in PTH levels, was improved by all vitamin D preparations regardless of preparation used or the route or frequency of administration. Fewer episodes of high blood calcium levels and lower overall serum calcium levels occurred with the non calcium‐containing binder, sevelamer, compared with calcium‐containing binders. As newer treatments for renal bone disease are developed, comparisons with the current standard therapies will be required in well designed RCTs in children using outcome measures including those of direct clinical relevance to children and their families such as rates of growth, reduction in bone fractures and bone pain and reduction in calcification in blood vessels.

Molecular determinants of extracellular matrix mineralization in bone and blood vessels

Mineralization imparts important biomechanical and other functional properties to bones and teeth. Ectopic pathologic mineralization, however, occurring in soft tissues such as blood vessels, kidneys, articular cartilage and also in body fluids, including urine and synovial fluid, is generally debilitating, often painful and typically is destructive of compromised tissue. Here we review new findings on direct molecular determinants of mineralization operating locally at the level of the extracellular matrix, with a focus on bone and blood vessels. Accumulating evidence indicates important key roles for secreted noncollagenous proteins in regulating mineralization, wherein they also contribute structurally to the scaffolding properties of the extracellular matrix. Mineral-binding proteins contain conserved acidic peptide domains (often highly phosphorylated), which bind strongly to calcium within the apatitic mineral phase of bone and calcified blood vessels to regulate crystal growth. Other recent work has underscored the importance of the small-molecule mineralization inhibitor pyrophosphate in inhibiting tissue mineralization - an inhibition released through its enzymatic cleavage by tissue-nonspecific alkaline phosphatase. Recent findings on mechanisms involved in matrix vesicle-mediated mineralization are also discussed. Mechanistic details are emerging that describe a scenario wherein the combined actions of mineral-binding noncollagenous matrix peptides/proteins within a scaffolding of collagen (and also elastin in blood vessels), phosphatases and matrix vesicles all contribute importantly to promoting or limiting mineralization.

Dietary magnesium, not calcium, prevents vascular calcification in a mouse model for pseudoxanthoma elasticum

Pseudoxanthoma elasticum (PXE) is a heritable disorder characterized by ectopic calcification of connective tissue in skin, Bruch’s membrane of the eye, and walls of blood vessels. PXE is caused by mutations in the ABCC6 gene, but the exact etiology is still unknown. While observations on patients suggest that high calcium intake worsens the clinical symptoms, the patient organization PXE International has published the dietary advice to increase calcium intake in combination with increased magnesium intake. To obtain more data on this controversial issue, we examined the effect of dietary calcium and magnesium in the Abcc6 −/− mouse, a PXE mouse model which mimics the clinical features of PXE. Abcc6 −/− mice were placed on specific diets for 3, 7, and 12 months. Disease severity was measured by quantifying calcification of blood vessels in the kidney. Raising the calcium content in the diet from 0.5% to 2% did not change disease severity. In contrast, simultaneous increase of both calcium (from 0.5% to 2.0%) and magnesium (from 0.05% to 0.2%) slowed down the calcification significantly. Our present findings that increase in dietary magnesium reduces vascular calcification in a mouse model for PXE should stimulate further studies to establish a dietary intervention for PXE.