Alterations In Blood Cells Research Articles

Characterization of the Biocompatibility and Mechanical Properties of Polyurea Organic Aerogels with the Vascular System: Potential as a Blood Implantable Material

Our goal was to compare the biocompatibility of Desmodur N3300-derived polyurea aerogels to that of X-MP4-T045 templated mesoporous silica aerogels. The effects of N3300 polyurea aerogels on the vascular system were evaluated by hemolysis, platelet activity, endothelial cell activity, and inflammatory responses. Aerogel morphology was examined using SEM and nano-indentation. Results indicate that N3300 aerogels do not alter blood cell or inflammatory responses and did not absorb proteins. They are compatible with endothelial cells. Overall, N3300 aerogels share similar biocompatibility as X-MP4-T045 aerogels but changes were observed in gel morphology. Therefore, N3300 aerogels may be suitable for various cardiovascular applications.

Effects of 10-GHz Microwaves on Hematological Parameters in Swiss Albino Mice and Their Modulation by Prunus avium

The objective of this study was to investigate the modulatory role of Prunus avium fruit extract (PAE) on several blood parameters after exposure to 10-GHz microwaves. Swiss albino mice from an inbred colony were selected and divided into 3 groups. Mice in group I served as the control; they were placed in a Plexiglas cage (without energizing the system) for 2 hours/day for 30 consecutive days. Group II mice were exposed to 10-GHz microwaves for 2 hours/day for 30 consecutive days. Mice in group III received PAE (500 mg/kg/body weight) orally once daily 1 hour before exposure to 10-GHz microwaves (2 hours/day) for 30 consecutive days. After 30 days of treatment, blood samples were collected from mice in all groups and analyzed. Hemoglobin, monocytes, packed cell volume, red blood cells, mean corpuscular hemoglobin concentration declined significantly (P ≤ 0.01), whereas white blood cells, lymphocytes, erythrocyte sedimentation rate, and mean corpuscular volume increased significantly (P ≤ 0.01) compared to the control group (group I). Cholesterol, alkaline phosphatase, and lipid peroxidation also increased significantly (P ≤ 0.01). Depletion in blood sugar, total protein, acid phosphatase, and glutathione levels was noted after microwave exposure compared with levels in the sham-exposed (control) mice. Histopathological alterations in blood cells also were seen. Signs of improvements in the hematological, biochemical, and histopathological parameters were recorded in group III, where PAE was supplemented before exposure. Exposure to microwaves influences hematological parameters, which could be ameliorated by the supplementation of PAE.

Alteration of peripheral blood cells in tubal ectopic pregnancy

To investigate whether mean platelet volumes and leukocyte counts are altered significantly in patients with tubal ectopic pregnancy (TEP). Retrospective analysis of mean platelet volumes and leukocyte counts of 138 TEP patients, diagnosed between 2005 and 2012, and the control group consisting of 72 pregnants was performed. Patients with TEP were further subdivided into 2 subgroups composed of 72 ruptured and 66 non-ruptured cases. Statistical analysis was performed using the Kruskal-Wallis and the Mann-Whitney U tests. Mean platelet volume was found to be larger in patients with TEP (whether ruptured or non-ruptured) when compared to controls (p = 0.007). However no significant difference could be observed between the ruptured or non-ruptured cases (p = 0.89). With respect to leukocytosis, the TEP group with tubal rupture had significantly higher white blood cell numbers when compared to the non-ruptured TEP and the control groups (p = 0.022 and p < 0.007, respectively). Mean platelet volume seems to be higher in ectopic pregnancy and this finding evokes a possible role of increased platelet activity in the pathophysiology Leukocytosis may occur more apparently in EP cases with tubal rupture. However, further prospective, controlled and with a larger sample size studies must be conducted to find clues on the correlation between the clinical entities and laboratory findings.

Alterations of haemorheological parameters in patients with Peripheral Arterial Disease

Peripheral arterial disease (PAD), is a common manifestation of systemic atherosclerosis. Advances on the development of such vascular disease have described with a number of novel risk factors. Hyperviscosity, due to alterations of blood cells and plasma components, may play a role on the pathogenesis of the disease. Aim of this study was to evaluate the possible association between hemorheological variables and PAD. The hemorheological variables [whole blood viscosity (WBV), erythrocyte deformability index (DI), plasma viscosity (PLV)] were analyzed in 90 patients and in 180 healthy subjects. WBV and PLV were measured by a Rotational Viscosimeter and DI by a filtrometer. DI and PLV were significantly different in patients as compared to controls. To investigate the possible association between these parameters and the disease we divided the study population into tertiles. At the univariate analysis, we found a significant association between the highest tertiles of PLV, of DI and the disease. A model adjusted for traditional risk factors showed an association between highest tertiles of PLV and PAD. After adjustment for confounding parameters highest tertiles of PLV remained to be significantly associated with the disease. Our data indicate that an alteration of plasma viscosity may modulate the predisposition to PAD.

A new biomarker to assess the grade of dysplasia in intraductal pancreatic mucinous neoplasms (IPMN) branch ducts

s / Pancreatology 12 (2012) 502–597 513 Results: Subcutaneously administrated cerulein in dosage of 5 and 10 mg/kg resulted in AP in rats, with significant changes in red blood cell deformability and alterations in erythrocyte aggregation. The presence of AP could be confirmed by amylase testing and histological examination. The earliest impairment of the red blood cell deformability could be observed 1 hour after cerulein administration in 10 mg/kg dosage. Conclusion: We found micro-rheological changes in cerulein-induced acute pancreatitis, showing further differences depending on the cerulein dosage and gender. Female animals had the worst rheological results, and the mortality was the highest among them. This model seems to be suitable for further comparative studies.

Gene Regulatory Networks Controlling Hematopoietic Progenitor Niche Cell Production and Differentiation in the Drosophila Lymph Gland

Hematopoiesis occurs in two phases in Drosophila, with the first completed during embryogenesis and the second accomplished during larval development. The lymph gland serves as the venue for the final hematopoietic program, with this larval tissue well-studied as to its cellular organization and genetic regulation. While the medullary zone contains stem-like hematopoietic progenitors, the posterior signaling center (PSC) functions as a niche microenvironment essential for controlling the decision between progenitor maintenance versus cellular differentiation. In this report, we utilize a PSC-specific GAL4 driver and UAS-gene RNAi strains, to selectively knockdown individual gene functions in PSC cells. We assessed the effect of abrogating the function of 820 genes as to their requirement for niche cell production and differentiation. 100 genes were shown to be essential for normal niche development, with various loci placed into sub-groups based on the functions of their encoded protein products and known genetic interactions. For members of three of these groups, we characterized loss- and gain-of-function phenotypes. Gene function knockdown of members of the BAP chromatin-remodeling complex resulted in niche cells that do not express the hedgehog (hh) gene and fail to differentiate filopodia believed important for Hh signaling from the niche to progenitors. Abrogating gene function of various members of the insulin-like growth factor and TOR signaling pathways resulted in anomalous PSC cell production, leading to a defective niche organization. Further analysis of the Pten, TSC1, and TSC2 tumor suppressor genes demonstrated their loss-of-function condition resulted in severely altered blood cell homeostasis, including the abundant production of lamellocytes, specialized hemocytes involved in innate immune responses. Together, this cell-specific RNAi knockdown survey and mutant phenotype analyses identified multiple genes and their regulatory networks required for the normal organization and function of the hematopoietic progenitor niche within the lymph gland.

Construction and phenotypic analysis of mice carrying a duplication of the major histocompatibility class I (MHC-I) locus

Copy number variation (CNV) has been associated increasingly with altered susceptibility to human disease. Large CNVs are likely to incur disease risk or resilience via predictable changes in gene dosage that are relatively straightforward to model using chromosomal engineering in mice. The classical class I major histocompatibility locus (MHC-I) contains a dense set of genes essential for innate immune system function in vertebrates. MHC-I genes are highly polymorphic and genetic variation in the region is associated with altered susceptibility to a wide variety of common diseases. Here we investigated the role of gene dosage within MHC-I on susceptibility to disease by engineering a mouse line carrying a 1.9-Mb duplication of this region [called Dp(MHC-I)]. Extensive phenotypic analysis of heterozygous (3N) Dp(MHC-I) animals did not reveal altered blood and stem cell parameters, susceptibility to high-fat diet, death by cancer, or contact dermatitis. However, several measures of disease severity in a model of atherosclerosis were improved, suggesting dosage-sensitive modulators of cardiovascular disease. Homozygous Dp(MHC-I)/Dp(MHC-I) mice demonstrated embryonic lethality. These mice serve as a model for studying the consequences of targeted gene dosage alteration in MHC-I with functional and evolutionary implications.

Does Oxidative Stress Play a Critical Role in Cardiovascular Complications of Kawasaki Disease?

The aim of the present work was to evaluate the contribution of the different reactive oxidizing species to systemic oxidative stress in the whole blood of patients with Kawasaki disease (KD). This is a rare generalized systemic vasculitis typical of the early childhood characterized by inflammation and endothelial dysfunction with a high risk for cardiovascular fatal events. We found that, compared to age-matched healthy donors, blood from KD patients showed increased production of oxygen- and nitrogen-derived species as detected by electron paramagnetic resonance (EPR) spin probing with the cyclic hydroxylamine 1-hydroxy-3-carboxy-pyrrolidine. The (•)NO pathway involvement was also confirmed by the decreased concentrations of the endogenous (•)NO synthase inhibitor asymmetric dimethyl-arginine and the increased amounts of 3-nitrotyrosine in plasma. Further, increased plasma yields of the proinflammatory enzyme myeloperoxidase were also observed. The appearance of circulating red blood cell alterations typically associated with oxidative imbalance and premature aging (e.g., decrease of total thiol content, glycophorin A, and CD47 expression, as well as increase of phosphatidylserine externalization) has also been detected. Collectively, our observations lead to hypothesize that the simultaneous oxidative and nitrative stress occurrence in the blood of KD patients may play a pathogenetic role in the cardiovascular complications often associated with this rare disease.

Central-peripheral temperature gradient: an early diagnostic sign of late-onset neonatal sepsis in very low birth weight infants

We assessed central-peripheral temperature gradient alteration for the diagnosis of late-onset neonatal sepsis and compared earliness detection of this sign with altered blood cell count and C-reactive protein. Thirty-one preterm babies (<1500 g or <32 weeks) participated in an observational prospective study. Axillary (central) and sole (peripheral) temperatures were continuously monitored with a thermal probe (ThermoTracer; Dräger Medical AGF & Co. KgaA, Lübeck, Germany) adjusting incubator air temperature for a thermal gradient <1.5°C. Central-peripheral temperature alteration was defined as a thermal gradient >2°C that could not be corrected with protocolized air temperature modifications. Proven (positive blood culture) sepsis and probable late-onset sepsis were recorded. Late-onset sepsis was diagnosed in 11 neonates (proven, 9; probable, 2). Thermal gradient alteration was present in 12 cases, in association with the onset of sepsis in 10 and concomitantly with a ductus arteriosus and stage 1 necrotizing enterocolitis in 2. Thermal gradient alteration had a sensitivity of 90.9% [95% confidence interval (CI), 62.3-98.4] and specificity of 90% (95% CI, 69.9-97.2%), and in 80% of cases, it occurred before abnormal laboratory findings. Central-peripheral temperature gradient monitoring is a feasible, non-invasive, and simple tool easily applicable in daily practice. An increase of >2°C showed a high-sensitivity and specificity for the diagnosis of late-onset sepsis.

DNA methylation changes in whole blood is associated with exposure to the environmental contaminants, mercury, lead, cadmium and bisphenol A, in women undergoing ovarian stimulation for IVF

Changes in DNA methylation may play an important role in the deleterious reproductive effects reported in association with exposure to environmental pollutants. In this pilot study, we identify candidate methylation changes associated with exposure to pollutants in women undergoing in vitro fertilization (IVF). Blood and urine were collected from women on the day of oocyte retrieval. Whole blood was analyzed for mercury and lead, and urine for cadmium using inductively coupled plasma mass spectrometry. Unconjugated bisphenol A (BPA) was analyzed in serum using high-performance liquid chromatography with Coularray detection. Participants were dichotomized as higher or lower exposure groups by median concentrations. Using the Illumina GoldenGate Methylation Cancer Panel I, DNA methylation in whole blood from 43 women was assessed at 1505 CpG sites for association with exposure levels of each pollutant. Candidate CpG sites were identified using a Diff Score >|13| (P< 0.05) and an absolute difference >10% which were confirmed using bisulfite pyrosequencing. Methylation of the GSTM1/5 promoter was increased for women with higher mercury exposure (P= 0.04); however, no correlation was observed (r= 0.17, P= 0.27). Reduced methylation was detected in the COL1A2 promoter in women with higher exposure to lead (P= 0.004), and an inverse correlation was observed (r = - 0.45, P= 0.03). Lower methylation of a promoter CpG site at the TSP50 gene was detected in women with higher BPA exposure (P= 0.005), and again an inverse correlation was identified (r = - 0.51, P= 0.001). Altered DNA methylation at various CpG sites was associated with exposure to mercury, lead or BPA, providing candidates to be investigated using a larger study sample, as the results may reflect an independently associated predictor (e.g. socioeconomic status, diet, genetic variants, altered blood cell composition). Further studies accommodating variations in these factors will be needed to confirm these associations and identify their underlying causes.

Evaluation of antioxidant activity of Ammania baccifera (L.) Whole plant extract in rats

ObjectiveTo study the effect of antioxidant activity of the ethanol extract of whole plant of Ammania baccifera, Linn (EEAB). MethodsTo investigate in rats against carbon tetrachloride (CCl4) induced erythrocyte damage. Simultaneous intraperitoneal administration of the crude extracts (600 or 800 mg/kg body weight/day) with carbon tetrachloride (1ml/kg of body weight) to rats for alternate days of two weeks protected the loss of functional integrity and membrane lipid alteration in red blood cells induced by oxidative stress. ResultsEEAB inhibited the accumulation of lipid peroxidation products in the plasma as well as maintained the activities of antioxidant enzymes such as superoxide dismutase (SOD) and catalase. The extracts further had the ability to decrease the membrane fluidity induced by carbon tetrachloride. ConclusionIt can therefore be suggested that the whole plant of Ammania baccifera, Linn possess an erythrocyte protective activity against drug induced oxidative stress. These findings also provide a rationale for further studies on isolation of active principles and its pharmacological evaluation.

Evaluation of antioxidant activity of Ammania baccifera (L.) whole plant extract in rats

ObjectiveTo study the effect of antioxidant activity of the ethanol extract of whole plant of Ammania baccifera, Linn (EEAB). MethodsTo investigate antioxidant activity of EEAB against carbon tetrachloride (CCl4) induced erythrocyte damage in rats, intraperitoneal administration of the crude extracts (600 or 800 mg/kg body weight/day) with CCl4 (1 mL/kg of body weight) was injected into rats for alternate days of two weeks. The loss of functional integrity and membrane lipid alteration in red blood cells induced by oxidative stress was observed. ResultsEEAB inhibited the accumulation of lipid peroxidation products in the plasma as well as maintained the activities of antioxidant enzymes such as superoxide dismutase and catalase. The extracts further had the ability to decrease the membrane fluidity induced by CCl4. ConclusionsIt can therefore be concluded that the whole plant of Ammania baccifera Linn possesses erythrocyte protective activity against drug induced oxidative stress. These findings also provide a rationale for further studies on isolation of active principles and its pharmacological evaluation.

Micro-rheological changes during experimental acute pancreatitis in the rat

Although microcirculatory disturbances play pivotal role in the pathomechanism of acute pancreatitis (AP), very few papers can be found which had been tested any of hemorheological parameters. The aim of our study was to analyze the hemorheological changes in cerulein-induced experimental acute pancreatitis in rat in two doses (5 and 10 μg/kg, s.c.). Male and female rats were subjected to Control group, or AP with 5 or 10 μg/kg cerulein groups. Blood samplings (lateral caudal vein) were completed before cerulein administration, and 1, 2 and 24 hours later. Hematological parameters, amylase activity, erythrocyte deformability (ektacytometry) and aggregation (light-transmission method) were tested. The presence of AP could be confirmed by amylase testing and histological examination. The earliest impairment of the red blood cell deformability could be observed 1 hour after cerulein administration in 10 μg/kg dosage. Female animals had the worst rheological results with high mortality. In conclusion, subcutaneously administrated cerulein in dosage of 5 and 10 μg/kg resulted in AP in rats, with significant changes in red blood cell deformability and alterations in erythrocyte aggregation. This model seems to be suitable for further comparative studies.

Laminin Expression Is Necessary for Maintenance of the Vascular Hematopoietic Niche

Abstract 217Laminins are heterotrimeric proteins that are the backbone for all basal laminas. They provide structural support, points for focal adhesion, and biochemical feedback for nearby cells. Laminins are found in many tissues, including bone marrow and lymphoid organs, and are detected in the discontinuous basal lamina of sinusoidal blood vessels. Laminin g1 is the predominant gamma subunit found in the bone marrow and lymphoid tissues. Here we show that the continuous expression of laminin in adulthood is necessary for viability of the vascular hematopoietic niche (sinusoidal endothelial cells). In the absence of laminin, this niche fails and hematopoiesis is impaired.To determine if sinusoidal laminin expression correlates with bone marrow failure and recovery, we used a well-established model of bone marrow failure. Wild type mice were treated with a sublethal dose of 5-fluoruracil (5-FU), and bone marrow was analyzed for disruption of sinusoid architecture and endothelial cell receptor and laminin expression. As described in other studies, shortly after treatment with 5-FU, bone marrow sinusoids became disorganized and hemorrhagic, and endothelial cells lost expression of VEGFR2. In addition, sinusoids lost their laminin-containing basal lamina. These changes correlated with bone marrow failure and onset of peripheral blood pancytopenia. As the sinusoids regained normal cytoarchitecture and VEGFR2 expression was normalized, sinusoid expression of laminin also returned to basal levels. With 5-FU-induced bone marrow failure and recovery, hematopoiesis correlated with laminin expression in the vascular hematopoietic stem cell niche.To test whether laminin expression directly affects the quality of the niche and hematopoiesis, a mutant mouse line was generated in which laminin g1 expression could be deleted by brief exposure to tamoxifen (TM). Control mice were littermates that lacked the TM-responsive Cre transgene. Prior to TM treatment, adult mutant and control mice had normal peripheral blood cell counts, and there was no evidence of gene recombination in genomic DNA samples. Adult mutant and control mice were then injected with either TM or vehicle, and the peripheral blood, bone marrow, spleen, and liver were collected after three weeks. Laminin g1 genes were deleted and laminin expression was lost in bone marrow, spleen, and liver sinusoids of only the TM-treated mutant mice. These mice also became thrombocytopenic and leukopenic. Flow cytometry showed early arrest of B-lymphocyte development within the bone marrow, bone marrow sinusoids became hemorrhagic, and the normal cytoarchitecture of the sinusoids and endothelial expression of VEGFR2 were lost. All other mouse groups were unaffected.These results suggest that continuous laminin expression is necessary for support of sinusoidal endothelial cells and the vascular hematopoietic niche. Disruption of the hematopoietic microenvironment is sufficient to alter blood cell development and release into peripheral circulation. These studies support the critical role of the microenvironment and stroma in supporting hematopoiesis. Disclosures:No relevant conflicts of interest to declare.

Aberrant Epigenetic and Genetic Marks Are Seen in Myelodysplastic Leukocytes and Reveal Dock4 as a Candidate Pathogenic Gene on Chromosome 7q

Myelodysplastic syndromes (MDS) are characterized by abnormal and dysplastic maturation of all blood lineages. Even though epigenetic alterations have been seen in MDS marrow progenitors, very little is known about the molecular alterations in dysplastic peripheral blood cells. We analyzed the methylome of MDS leukocytes by the HELP assay and determined that it was globally distinct from age-matched controls and was characterized by numerous novel, aberrant hypermethylated marks that were located mainly outside of CpG islands and preferentially affected GTPase regulators and other cancer-related pathways. Additionally, array comparative genomic hybridization revealed that novel as well as previously characterized deletions and amplifications could also be visualized in peripheral blood leukocytes, thus potentially reducing the need for bone marrow samples for future studies. Using integrative analysis, potentially pathogenic genes silenced by genetic deletions and aberrant hypermethylation in different patients were identified. DOCK4, a GTPase regulator located in the commonly deleted 7q31 region, was identified by this unbiased approach. Significant hypermethylation and reduced expression of DOCK4 in MDS bone marrow stem cells was observed in two large independent datasets, providing further validation of our findings. Finally, DOCK4 knockdown in primary marrow CD34(+) stem cells led to decreased erythroid colony formation and increased apoptosis, thus recapitulating the bone marrow failure seen in MDS. These findings reveal widespread novel epigenetic alterations in myelodysplastic leukocytes and implicate DOCK4 as a pathogenic gene located on the 7q chromosomal region.

Procoagulant properties of microparticles released from red blood cells in paroxysmal nocturnal haemoglobinuria

Thrombosis in paroxysmal nocturnal haemoglobinuria (PNH) has been suggested to be due to several pathophysiological states: a suppressed fibrinolytic system, increased leucocyte-derived tissue factor, complement (C')-mediated damage to platelets and endothelia, or increased platelet- and endothelium-derived microparticles (MPs). Because haemolytic attack is often accompanied by thrombosis in PNH, we studied the role of C'-induced release of MPs in the thrombogenesis of PNH. C' activation induced procoagulant alteration in PNH red blood cells (RBC), when assessed by thrombin generation in the presence of C'-activated PNH RBC, which was abolished by their subsequent treatment with annexin V. Significant amounts of procoagulant MPs, measured by phosphatidylserine-binding prothrombinase activity, were released from PNH RBC in association with the formation of C5b-9, but not significantly before C5b-8. Generation of procoagulant, annexin V-binding, MPs from C'-activated RBC was studied also by flow cytometry. While phorbol 12-myristate 13-acetate, an activator of protein kinase C (PKC), induced the release of MPs from normal RBC as well as PNH RBC, C'-induced release of MPs from PNH RBC was Ca(2+) -independent and not associated with the activation of PKC, calpain or caspase. Procoagulant properties of MPs released from PNH RBC could contribute to the thrombogenesis of PNH.

English

The effect of the oral administration of an aqueous suspension of Nigella sativa (50 mg/kg b.wt.) against morphological, cytological and biochemical alterations of blood cells in mice treated with carbon tetrachloride (CCl4) was studied. CCl4 was administered at a dose of 1.9 ml/kg b.wt (¼ LD50) every other day for three successive weeks. The results indicated significant changes in the haematological parameters in animals intoxicated with CCl4. Morphological and ultrastructural alterations including both nucleus and cytoplasm of peripheral blood cells were also recorded. Treatment of the animals with N. sativa improved both physiological and structural changes induced by CCl4.

Myocardial gene expression alterations in peripheral blood mononuclear cells of patients with idiopathic dilated cardiomyopathy

To assess cardiac gene expression in peripheral blood cells of patients with idiopathic dilated cardiomyopathy (IDCM) and its relationship to echocardiographic left ventricular (LV) function. A complete echocardiographic study and blood sampling were performed in 65 consecutive stable IDCM patients with LV ejection fraction (LVEF) 31.76 +/- 10.07% and chronic mild to moderate heart failure (NYHA functional class II to III) for > or =9 months. Blood samples from 19 healthy individuals were included for comparison. Transcript levels of myocardin, GATA4, alpha- and beta-myosin heavy chain (MHC), sarcoplasmic reticulum calcium ATPase 2 (SERCA2), and phospholamban were determined by quantitative real-time reverse transcription-polymerase chain reaction. Myocardin (24.88 +/- 4.93 vs. 3.98 +/- 1.12, P = 0.0048) and GATA4 (17.85 +/- 4.85 vs. 0.45 +/- 0.15, P = 0.0069 x 10(-5)) were upregulated in IDCM patients compared with controls, whereas SERCA2 (5.11 +/- 0.42 vs. 8.93 +/- 1.07, P = 0.001) was downregulated. In IDCM patients, myocardin (r = 0.279, P = 0.025), GATA4 (r = 0.314, P = 0.011), beta-MHC (r = 0.444, P=0.0002), and alpha-MHC (r = 0.272, P = 0.034) showed positive correlations, whereas SERCA2 (r = -0.264, P = 0.034) exhibited a negative correlation with LVEF. Patients with elevated LV filling pressures had lower myocardin (15.06 +/- 3.10 vs. 43.12 +/- 12.03, P = 0.048), GATA4 (8.96 +/- 2.17 vs. 34.38 +/- 12.60, P = 0.026), beta-MHC (10.59 +/- 4.05 vs. 16.43 +/- 4.91, P = 0.013), and alpha-MHC (0.27 +/- 0.08 vs. 0.79 +/- 0.20, P = 0.033) and higher SERCA2 (5.65 +/- 0.54 vs. 3.90 +/- 0.61, P = 0.037) levels. Patients with atrial fibrillation (AF) had higher SERCA2 levels compared with sinus rhythm patients (6.75 +/- 0.84 vs. 4.54 +/- 0.45, P = 0.017). Our data indicate that cardiac gene expression alterations in peripheral blood cells of IDCM patients may reflect alterations in LV function, whereas the presence of AF may be associated with increased SERCA2 levels in these patients.

Improved viscosity modeling in patients with type 2 diabetes mellitus by accounting for enhanced red blood cell aggregation tendency

Distorted wall shear stress (WSS) in patients with type 2 diabetes mellitus (T2DM) may be partly explained by an altered red blood cell aggregation tendency (RAT) on viscosity at low shear rate (SR). The present study evaluates viscosity modeling by implementation of hematocrit and RAT in patients with and without T2DM (non-T2DM). A Couette viscometer and LORCA aggregometer provided viscosity and RAT on 6 shear rates in 55 patients (46-78 yrs, 66% male, T2DM: n = 28), following informed consent. Using a K-fold cross-validation, two linear mixed models predicted by SR and Hct and by SR, Hct and RAT were compared. In non-T2DM modeling was improved in relatively low RATs (48%, p = 1.0 x 10-11) and became worse in relatively high RATs (-18%, p = 0.019). In T2DM the opposite was observed, as modeling became worse in relatively low RATs (-16%, p = 0.001) but was improved in relatively high RATs (22%, p = 0.022). In addition to confirming previous research, major differences in modeling improvement between T2DM and non-T2DM were found. Especially patients with T2DM, a high RAT and often high viscosity at low SR benefit from a more accurate viscosity modeling. Further studies should evaluate how these findings affect WSS in these patients.

Downregulation and aberrant promoter methylation of p16INK4A: A possible novel heritable susceptibility marker to retinoblastoma

RB loss has long been recognized as the causative genetic alteration underlying retinoblastoma but it is increasingly evident that other alterations are required for the tumor to develop. Therefore, we set out to identify additional inheritable susceptibility markers and new potential preventive and therapeutic targets for retinoblastoma. We focused on the p16INK4A tumor suppressor gene because of its possible role in retinoblastoma pathogenesis and its involvement in predisposition to familial cancer. p16INK4A expression was analyzed in tumor samples from retinoblastoma patients by immunohistochemistry and in peripheral blood cells from both patients and their parents by real-time quantitative reverse transcription-PCR (qRT-PCR). Since promoter methylation is a common mechanism regulating p16INK4A expression, the methylation status of its promoter was also analyzed in blood samples from patients and their parents by methylation-specific PCR. A downregulation of p16INK4A was observed in 55% of retinoblastoma patients. Interestingly, in 56% of the cases showing p16INK4A downregulation at least one of the patients' parents bore the same alteration in blood cells. Analysis of p16INK4A promoter methylation showed hypermethylation in most patients with p16INK4A downregulation and in the parents with the same alteration in p16INK4A expression. The finding that p16INK4A was downregulated both in patients and their parents suggests that this alteration could be a novel inheritable susceptibility marker to retinoblastoma. The observation that p16INK4A downregulation seems to be due to its promoter hypermethylation opens the way for the development of new preventive and therapeutic strategies using demethylating agents.