A multiplexed immunochemical microarray for the determination of cardiovascular disease biomarkers.

A fluorescence antibody microarray has been developed for the determination of relevant cardiovascular disease biomarkers for the analysis of human plasma samples. Recording characteristic protein molecular fingerprints to assess individual's states of health could allow diagnosis to go beyond the simple identification of the disease, providing information on its stage or prognosis. Precisely, cardiovascular diseases (CVDs) are complex disorders which involve different degenerative processes encompassing a collection of biomarkers related to disease progression or stage. The novel approach that we propose is a fluorescent microarray chip has been developed accomplishing simultaneous determination of the most significant cardiac biomarkers in plasma aiming to determine the CVD status stage of the patient. As proof of concept, we have chosen five relevant biomarkers, C-reactive protein (CRP) as biomarker of inflammation, cystatin C (CysC) as biomarker of renal failure that is directly related with heart failure, cardiac troponin I (cTnI) as already established biomarker for cardiac damage, heart fatty acid binding protein as biomarker of ischemia (H-FABP), and finally, NT-proBNP (N-terminal pro-brain natriuretic peptide), a well-established heart failure biomarker. After the optimization of the multiplexed microarray, the assay allowed the simultaneous determination of 5 biomarkers in a buffer solution reaching LODs of 15 ± 5, 3 ± 1, 24 ± 3, 25 ± 3, and 3 ± 1 ng mL-1, for CRP, CysC, H-FABP, cTnI, and NT-proBNP, respectively. After solving the matrix effect, and demonstrating the accuracy for each biomarker, the chip was able to determine 24 samples per microarray chip. Then, the microarray has been used on a small pilot clinical study with 29 plasma samples from clinical patients which suffered different CVD and other related disorders. Results show the superior capability of the chip to provide clinical information related to the disease in terms of turnaround time (1 h 30 min total assay and measurement) and amount of information delivered in respect to reference technologies used in hospital laboratories (clinical analyzers). Despite the failure to detect c-TnI at the reported threshold, the microarray technology could be a powerful approach to diagnose the cardiovascular disease at early stage, monitor its progress, and eventually providing information about an eminent potential risk of suffering a myocardial infarction. The microarray chip here reported could be the starting point for achieving powerful multiplexed diagnostic technologies for the diagnosis of CVDs or any other pathology for which biomarkers have been identified at different stages of the disease.

The evolutionarily conserved factor Sus1/ENY2 plays a role in telomere length maintenance.

Sus1 is a conserved protein involved in histone H2B de-ubiquitination and mRNA export from the nucleus in eukaryotes. Previous studies implicated Sus1 partners in genome integrity including telomere homeostasis. However, the implication of Sus1 in telomere maintenance remains largely unknown. In this study, we found that yeast Sus1 interacts physically and genetically with factors involved in telomere maintenance and its absence leads to elongated telomeres. Deletion of several of Sus1's partners also leads to longer telomeres. Our results rule out a direct role for Sus1 in recruiting telomerase subunits to telomeres. However, we observe that deletion of SUS1 leads to elongated telomeres even in the presence of mutations like sem1Δ, esc2Δ and rsc2Δ, which cause telomere shortening. We find that rsc2Δ (short telomeres) have reduced levels of mono-ubiquitinated histone H2B at lysine 123 (H2BK123ub1), whereas sus1Δ mutants or double-mutants sus1Δ rsc2Δ exhibit longer telomeres and higher H2BK123ub1 levels. These results suggest that Sus1 activity as a H2B de-ubiquitination modulator plays a role in negatively regulating telomere length. Our results provide solid evidence for a role of Sus1 in negatively regulating telomere length through the modulation of H2BK123 mono-ubiquitination and its interaction with the nuclear pore complex.

Impact of diabetes on the predictive value of heart failure biomarkers.

BACKGROUND: Patients with diabetes mellitus (DM) have an increased risk of developing heart failure (HF). Further, DM is associated with poor prognosis in patients with HF. Our aim was to determine whether DM has any impact on the predictive value of a multi-biomarker panel in patients with HF. METHODS: We included 1069 consecutive ambulatory HF patients in the study: age 66.2 ± 12.8 years, 33.5 ± 13.3 left ventricular ejection fraction, 36% diabetic patients. We measured serum concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP), high-sensitivity troponin T (hs-TnT), ST2, galectin-3, high-sensitivity C reactive protein (hs-CRP), cystatin-C, soluble transferrin receptor (sTfR), and neprilysin and followed patients for 4.9 ± 2.8 years. Primary endpoints were all-cause and cardiovascular death. RESULTS: During follow-up, 534 patients died; 283 died of cardiovascular causes. Diabetic subjects had higher mortality (57.7 vs. 45.6%, p < 0.001). NTproBNP (p = 0.07), hs-TnT (p < 0.001), galectin-3 (p < 0.001), and cystatin-C (p = 0.001) concentrations were higher in diabetic patients, whereas sTfR levels were lower (p = 0.005). There were no interactions between DM and NTproBNP, hs-TnT, galectin-3, hs-CRP, cystatin-C, sTfR, and neprilysin relative to risk prediction for all-cause or cardiovascular death. By contrast, ST2 significantly interacted with DM for all-cause (p = 0.02) and cardiovascular (p = 0.03) death. In diabetic patients, HRs for ST2 were 1.27 (95% CI 1.16-1.40, p < 0.001) and 1.23 (95% CI 1.09-1.39, p = 0.001) for all-cause and cardiovascular death, respectively. In nondiabetic patients, HRs for ST2 were 1.53 (95% CI 1.35-1.73, p < 0.001) and 1.64 (95% CI 1.31-2.05, p < 0.001) for all-cause and cardiovascular death, respectively. The multivariable Cox regression analysis showed that hs-TnT and ST2 were the only markers that were independently associated with both all-cause and cardiovascular mortality in patients with HF and diabetes. Moreover, in these patients, the combination of these two markers significantly increased discrimination as assessed by the area under the curve. CONCLUSIONS: Biomarkers used in the general population to predict the clinical course of heart failure are also useful in patients with diabetes. In these patients, among all the biomarkers analysed only hs-TnT and ST2 were independently associated with both all-cause and cardiovascular mortality.

The real-life value of ST2 monitoring during heart failure decompensation: impact on long-term readmission and mortality.

CONTEXT: Prognostic value of ST2 levels and dynamics has not been investigated in acute heart failure (AHF) using prospective real-life measurements. OBJECTIVE: The objective of this study is to investigate the prognostic value of ST2 in AHF. METHODS: ST2 levels were determined at admission (n = 182) and discharge (n = 85). Primary endpoint was the composite of all-cause death and HF rehospitalisation at one year. RESULTS: Discharge ST2 (HR 2.42 [95% CI 1.46-4], p = 0.001) and ΔST2 (HR 2.32 [95% CI 1.21-4.57], p = 0.01) but not admission ST2, remained independently prognostic for the primary endpoint after comprehensive multivariable adjustment. ST2 significantly improved prognosis stratification on top of clinical variables and NTproBNP. CONCLUSIONS: Routine clinical use of discharge ST2 and ST2 dynamics provide independent prognostic information.

ST2 pathogenetic profile in ambulatory heart failure patients.

BACKGROUND: Soluble ST2 is involved in multiple pathogenic pathways, including cardiac strain, inflammation, and myocardial necrosis with remodeling. The relative weight of ST2 and the point at which its prognostic value in heart failure (HF) is affected by different degrees of myocardial strain, inflammation, necrosis, and remodeling is unknown. METHODS AND RESULTS: We examined whether soluble ST2 levels improves HF risk stratification relative to other biomarkers representative of multiple pathogenic pathways-N-terminal pro-B-type natriuretic peptide (NT-proBNP; strain), high-sensitivity C-reactive protein (hsCRP; inflammation), and galectin-3 and high-sensitivity troponin T (hsTnT; necrosis and remodeling)-in 1,015 patients with mean left ventricular ejection fraction (LVEF) 33.5%. Mean follow-up was 4.2 ± 2.1 years. The correlation with soluble ST2 was highest with NT-proBNP (r = 0.32; P < .001) and lowest with galectin-3 (r = 0.15; P < .001). ST2 levels increased with increasing concentrations of the other biomarkers (P < .001 in all cases). During follow-up, 467 patients died. Soluble ST2 remained an independent prognosticator of risk at every tertile of each biomarker. This was observed even after adjusting for clinical parameters. CONCLUSIONS: Soluble ST2 may be regarded as a 3-in-1 prognosis biomarker in HF. ST2 provides valuable long-term risk stratification information in HF beyond that reported by other biomarkers of stretch, inflammation, necrosis, and remodeling.

Metabolic Syndrome Predicts Refractoriness to Intravenous Thrombolysis in Acute Ischemic Stroke.

BACKGROUND: Metabolic syndrome (MetS) has been associated with higher resistance to clot lysis at 24 hours after tissue plasminogen activator (tPA) administration in patients with acute ischemic stroke. We aimed to test this hypothesis at earlier time points, when neurointerventional rescue procedures may still be indicated to achieve arterial recanalization. METHODS: This is a prospective and observational study in consecutive stroke patients with MCA occlusion treated with IV tPA. MetS was diagnosed following the unified criteria of the last Joint Interim Statement 2009 participating several major organizations. The primary outcome variable was resistance to thrombolysis, defined as the absence of complete middle cerebral artery recanalization 2 hours after tPA bolus assessed by transcranial color-coded duplex or when rescue mechanical thrombectomy after IV tPA was required. Secondary outcome variables were dramatic neurological improvement (decrease in ≥10 points, or a National Institutes of Health Stroke Scale [NIHSS] score of 0-1 at 24 hours), symptomatic intracerebral hemorrhage following European-Australasian Acute Stroke Study II criteria, infarct volume at 24 hours (calculated by using the formula for irregular volumes, ABC/2), and good outcome (modified Rankin Scale score < 3) at 3 months. RESULTS: A total of 234 patients (median baseline NIHSS score 16 [10-20]) were included and 146 (62.4%) fulfilled MetS criteria. After multivariate analysis, MetS emerged as an independent predictor of resistance to thrombolysis (odds ratio = 2.2 [1.3-4.2], P = .01) and absence of dramatic neurological improvement (odds ratio = .5 [.28-.97], P = .04). In addition, MetS conferred poorer functional outcome, higher symptomatic intracerebral hemorrhage rate, and increased infarct volume, although these associations disappeared after adjustment for covariates. CONCLUSIONS: MetS predicts patients with middle cerebral artery occlusion refractory to early clot dissolution after IV tPA. This finding may help in acute clinical decision-making.

Sus1/ENY2: a multitasking protein in eukaryotic gene expression.

The purpose of this review is to provide a complete overview on the functions of the transcription/export factor Sus1. Sus1 is a tiny conserved factor in sequence and functions through the eukaryotic kingdom. Although it was discovered recently, research done to address the role of Sus1/ENY2 has provided in deep description of different mechanisms influencing gene expression. Initially found to interact with the transcription and mRNA export machinery in yeast, it is now clear that it has a broad role in mRNA biogenesis. Sus1 is necessary for histone H2B deubiquitination, mRNA export and gene gating. Moreover, interesting observations also suggest a link with the cytoplasmatic mRNP fate. Although the role of Sus1 in human cells is largely unknown, preliminary results suggest interesting links to pathological states that range from rare diseases to diabetes. We will describe what is known about Sus1/ENY2 in yeast and other eukaryotes and discuss some exciting open questions to be solved in the future.

Long-term prognostic value for patients with chronic heart failure of estimated glomerular filtration rate calculated with the new CKD-EPI equations containing cystatin C.

BACKGROUND: Correct estimation of renal function is crucial in assessing prognosis of patients with heart failure (HF). Recently, two new equations have been proposed to calculate estimated glomerular filtration rate (eGFR) with cystatin C alone or both creatinine and cystatin C. We assessed the prognostic value of eGFR estimated by these new equations in outpatients with HF. METHODS: The study included 879 patients with median age, 70.4 years; main etiology of HF ischemic heart disease, 52.7%; and median LVEF, 34%. RESULTS: eGFR estimates by the new equations correlated significantly with eGFR estimates from previous equations, with the best correlation observed between the 2 equations containing cystatin C [intraclass correlation coefficient 0.95 (95% confidence interval 0.94-0.95)]. During a median follow-up of 3.94 years, 371 patients died. The Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equations containing cystatin C were found to be best for predicting death [area under the ROC curve 0.685 for CKD-EPI-cystatin C and 0.672 for CKD-EPI-creatinine-cystatin C vs 0.632 for simplified Modification of Diet in Renal Disease Study traceable to isotope dilution mass spectrometry and 0.643 for CKD-EPI (all P < 0.001)]. The CKD-EPI-cystatin C equations also showed significantly better calibration and reclassification measurements for both integrated discrimination improvement and net reclassification improvement in predicting death (P < 0.001). Reclassification with these new equations was particularly better in the subgroup with intermediate eGFR [45-74 mL · min(-1) · (1.73 m(2))(-1)]. CONCLUSIONS: The two new CKD-EPI equations containing cystatin C are useful for HF risk stratification and show better prognostic performance than creatinine-only based eGFR equations, mostly in patients with intermediate eGFR. These equations seem appropriate for assessing prognosis of HF patients with moderate renal insufficiency.

Soluble ST2 serum concentration and renal function in heart failure.

BACKGROUND: Soluble ST2 (sST2) provides important prognostic information in patients with heart failure (HF). How sST2 serum concentration is related to renal function is uncertain. We evaluated the association between sST2 and renal function and compared its prognostic value in HF patients with renal insufficiency. METHODS AND RESULTS: Patients (n = 879; median age 70.4 years; 71.8% men) were divided into 3 subgroups according to estimated glomerular filtration rate (eGFR): ≥60 mL/min/1.73 m(2) (n = 337); 30-59 mL/min/1.73 m(2) (n = 352); and <30 mL/min/1.73 m(2) (n = 190). sST2 (rho = -0.16; P < .001), N-terminal pro-B-type natriuretic peptide (rho = -0.40; P < .001), and high-sensitivity cardiac troponin T (rho = -0.47; P < .001) inversely correlated with eGFR. All-cause mortality was the primary end point. During a median follow-up of 3.46 years, 312 patients (35%) died, 246 of them from the subgroup of 542 patients with eGFR <60 mL/min/1.73 m(2) (45%). Biomarker combination including sST2 showed best discrimination, calibration, and reclassification metrics in renal insufficiency patients (net reclassification improvement 16.6 [95% confidence interval (CI) 8.1-25; P < .001]; integrated discrimination improvement 4.2 [95% CI 2.2-6.2; P < .001]). Improvement in reclassification was higher in these patients than in the total cohort. CONCLUSIONS: The prognostic value of sST2 was not influenced by renal function. On top of other biomarkers, sST2 improved long-term prediction in patients with renal insufficiency even more than in the total cohort.

Cognitive patterns in relation to biomarkers of cerebrovascular disease and vascular risk factors.

BACKGROUND: Risk factors for vascular cognitive impairment (VCI) are the same as traditional risk factors for cerebrovascular disease (CVD). Early identification of subjects at higher risk of VCI is important for the development of effective preventive strategies. In addition to traditional vascular risk factors (VRF), circulating biomarkers have emerged as potential tools for early diagnoses, as they could provide in vivo measures of the underlying pathophysiology. While VRF have been consistently linked to a VCI profile (i.e., deficits in executive functions and processing speed), the cognitive correlates of CVD biomarkers remain unclear. In this population-based study, the aim was to study and compare cognitive patterns in relation to VRF and circulating biomarkers of CVD. METHODS: The Barcelona-AsIA Neuropsychology Study included 747 subjects older than 50, without a prior history of stroke or coronary disease and with a moderate to high vascular risk (mean age, 66 years; 34.1% women). Three cognitive domains were derived from factoral analysis: visuospatial skills/speed, verbal memory and verbal fluency. Multiple linear regression was used to assess relationships between cognitive performance (multiple domains) and a panel of circulating biomarkers, including indicators of inflammation, C-reactive protein (CRP) and resistin, endothelial dysfunction, asymmetric dimethylarginine (ADMA), thrombosis, plasminogen activator inhibitor 1 (PAI-1), as well as traditional VRF, metabolic syndrome and insulin resistance (homeostatic model assessment for insulin resistance index). Analyses were adjusted for age, gender, years of education and depressive symptoms. RESULTS: Traditional VRF were related to lower performance in verbal fluency, insulin resistance accounted for lower performance in visuospatial skills/speed and the metabolic syndrome predicted lower performance in both cognitive domains. From the biomarkers of CVD, CRP was negatively related to verbal fluency performance and increasing ADMA levels were associated with lower performance in verbal memory. Resistin and PAI-1 did not relate to cognitive function performance. CONCLUSION: Vascular risk factors, and markers of inflammation and endothelial dysfunction predicted lower performance in several cognitive domains. Specifically, cognitive functions associated with CRP are typically affected in VCI and overlap those related to VRF. ADMA indicated a dissociation in the cognitive profile involving verbal memory. These findings suggest that inflammation and endothelial dysfunction might play a role in the predementia cognitive impairment stages.

Deciphering the sex bias in housekeeping gene expression in adipose tissue: a comprehensive meta-analysis of transcriptomic studies.

BACKGROUND: As the housekeeping genes (HKG) generally involved in maintaining essential cell functions are typically assumed to exhibit constant expression levels across cell types, they are commonly employed as internal controls in gene expression studies. Nevertheless, HKG may vary gene expression profile according to different variables introducing systematic errors into experimental results. Sex bias can indeed affect expression display, however, up to date, sex has not been typically considered as a biological variable. METHODS: In this study, we evaluate the expression profiles of six classical housekeeping genes (four metabolic: GAPDH, HPRT, PPIA, and UBC, and two ribosomal: 18S and RPL19) to determine expression stability in adipose tissues (AT) of Homo sapiens and Mus musculus and check sex bias and their overall suitability as internal controls. We also assess the expression stability of all genes included in distinct whole-transcriptome microarrays available from the Gene Expression Omnibus database to identify sex-unbiased housekeeping genes (suHKG) suitable for use as internal controls. We perform a novel computational strategy based on meta-analysis techniques to identify any sexual dimorphisms in mRNA expression stability in AT and to properly validate potential candidates. RESULTS: Just above half of the considered studies informed properly about the sex of the human samples, however, not enough female mouse samples were found to be included in this analysis. We found differences in the HKG expression stability in humans between female and male samples, with females presenting greater instability. We propose a suHKG signature including experimentally validated classical HKG like PPIA and RPL19 and novel potential markers for human AT and discarding others like the extensively used 18S gene due to a sex-based variability display in adipose tissue. Orthologs have also been assayed and proposed for mouse WAT suHKG signature. All results generated during this study are readily available by accessing an open web resource ( https://bioinfo.cipf.es/metafun-HKG ) for consultation and reuse in further studies. CONCLUSIONS: This sex-based research proves that certain classical housekeeping genes fail to function adequately as controls when analyzing human adipose tissue considering sex as a variable. We confirm RPL19 and PPIA suitability as sex-unbiased human and mouse housekeeping genes derived from sex-specific expression profiles, and propose new ones such as RPS8 and UBB.

Housekeeping genes (HKG) are involved in the maintenance of essential cellular functions. They usually present constant expression levels and are relevant because of their usefulness as internal controls in gene expression studies. However, HKG can vary the gene expression profile depending on different variables such as sex, introducing errors in the experimental results. In this study, we have performed an exhaustive systematic review and applied a massive analysis of expression data to check which HKG presents this bias and which do not. The results confirm that certain classical HKG do not perform adequately as controls when analyzing human adipose tissue considering sex as a variable. We further confirm the suitability of RPL19 and PPIA as human and mouse HKG without sex bias derived from sex-specific expression profiles, and propose new ones such as RPS8 and UBB. These results will be of great use in upcoming studies where expression data need to be normalized without the inclusion of sex bias.

Hybrid Endometrial-Derived Hydrogels: Human Organoid Culture Models and In Vivo Perspectives.

The endometrium plays a vital role in fertility, providing a receptive environment for embryo implantation and development. Understanding the endometrial physiology is essential for developing new strategies to improve reproductive healthcare. Human endometrial organoids (hEOs) are emerging as powerful models for translational research and personalized medicine. However, most hEOs are cultured in a 3D microenvironment that significantly differs from the human endometrium, limiting their applicability in bioengineering. This study presents a hybrid endometrial-derived hydrogel that combines the rigidity of PuraMatrix (PM) with the natural scaffold components and interactions of a porcine decellularized endometrial extracellular matrix (EndoECM) hydrogel. This hydrogel provides outstanding support for hEO culture, enhances hEO differentiation efficiency due to its biochemical similarity with the native tissue, exhibits superior in vivo stability, and demonstrates xenogeneic biocompatibility in mice over a 2-week period. Taken together, these attributes position this hybrid endometrial-derived hydrogel as a promising biomaterial for regenerative treatments in reproductive medicine.

Biological signatures of asymptomatic extra- and intracranial atherosclerosis: the Barcelona-AsIA (Asymptomatic Intracranial Atherosclerosis) study.

BACKGROUND AND PURPOSE: Intracranial atherosclerotic disease (ICAD) remains a challenge for stroke primary and secondary prevention. Molecular pathways involved in the development of ICAD from its asymptomatic stages are largely unknown. In our population-based study, we aimed to compare the risk factor and biomarker profiles associated with intracranial and extracranial asymptomatic cerebral atherosclerosis. METHODS: The Asymptomatic Intracranial Atherosclerosis (AsIA) study cohort includes a random sample population of 933 white subjects >50 years with a moderate to high vascular risk (based on REGICOR score) and without a history of stroke (64% males; mean age, 66 years). Carotid and intracranial atherosclerosis were screened by cervical and transcranial color-coded Duplex ultrasound, being moderate to severe stenoses confirmed by MR angiography. We registered clinical and anthropometric data and created a biobank with blood samples at baseline. A panel of biomarkers involved in atherothrombogenesis was determined: C-reactive protein, asymmetric-dimethylarginine, resistin, and plasminogen activator inhibitor-1. Insulin resistance was quantified by Homeostasis Model Assessment index. RESULTS: After multinomial regression analyses, male sex, hypertension, smoking, and alcoholic habits were independent risk factors of isolated extracranial atherosclerotic disease. Diabetes and metabolic syndrome conferred a higher risk for ICAD than for extracranial atherosclerotic disease. Moreover, metabolic syndrome and insulin resistance were independent risk factors of moderate to severe ICAD but were not risk factors of moderate to severe extracranial atherosclerotic disease. Regarding biomarkers, asymmetric-dimethylarginine was independently associated with isolated ICAD and resistin with combined ICAD-extracranial atherosclerotic disease. CONCLUSIONS: Our findings show distinct clinical and biological profiles in subclinical ICAD and extracranial atherosclerotic disease. Insulin resistance emerged as an important molecular pathway involved in the development of ICAD from its asymptomatic stage.

Combined use of high-sensitivity cardiac troponin T and N-terminal pro-B type natriuretic peptide improves measurements of performance over established mortality risk factors in chronic heart failure.

BACKGROUND: Heart failure still maintains a high mortality. Biomarkers reflecting different pathophysiological pathways are under evaluation to better stratify the mortality risk. The objective was to assess high-sensitivity cardiac troponin T (hs-cTnT) in combination with N-terminal pro-B type natriuretic peptide (NT-proBNP) for risk stratification in a real-life cohort of ambulatory heart failure patients. METHODS: We analyzed 876 consecutive patients (median age 70.3 years, median left ventricular ejection fraction 34%) treated at a heart failure unit. A combination of biomarkers reflecting myocyte injury (hs-cTnT) and myocardial stretch (NT-proBNP) was used in addition to an assessment based on established mortality risk factors (age, sex, left ventricular ejection fraction, New York Heart Association functional class, diabetes, estimated glomerular filtration rate, ischemic etiology, sodium, hemoglobin, ß-blocker treatment, and angiotensin converting enzyme inhibitor or angiotensin II receptor blocker treatment). RESULTS: During a median follow-up of 41.4 months, 311 patients died. In the multivariable Cox proportional hazards model, hs-cTnT and NT-proBNP were independent prognosticators (P = .003 each). The combined elevation of both biomarkers above cut-off values significantly increased the risk of death (HR 7.42 [95% CI, 5.23-10.54], P < .001). When hs-cTnT and NT-proBNP were individually included in a model with established mortality risk factors, measurements of performance significantly improved. Results obtained for hs-cTnT compared with NT-proBNP were superior according to comprehensive discrimination, calibration, and reclassification analysis (net reclassification indices of 7.7% and 1.5%, respectively). CONCLUSIONS: hs-cTnT provides significant prognostic information in a real-life cohort of patients with chronic heart failure. Simultaneous addition of hs-cTnT and NT-proBNP into a model that includes established risk factors improves mortality risk stratification.

The population-based Barcelona-Asymptomatic Intracranial Atherosclerosis Study (ASIA): rationale and design.

BACKGROUND: Large-artery intracranial atherosclerosis may be the most frequent cause of ischemic stroke worldwide. Traditional approaches have attempted to target the disease when it is already symptomatic. However, early detection of intracranial atherosclerosis may allow therapeutic intervention while the disease is still asymptomatic. The prevalence and natural history of asymptomatic intracranial atherosclerosis in Caucasians remain unclear. The aims of the Barcelona-ASymptomatic Intracranial Atherosclerosis (ASIA) study are (1) to determine the prevalence of ASIA in a moderate-high vascular risk population, (2) to study its prognostic impact on the risk of suffering future major ischemic events, and (3) to identify predictors of the development, progression and clinical expression of this condition. METHODS/DESIGN: Cross-over and cohort, population-based study. A randomly selected representative sample of 1,503 subjects with a mild-moderate-high vascular risk (as defined by a REGICOR score ≥ 5%) and with neither a history of cerebrovascular nor ischemic heart disease will be studied. At baseline, all individuals will undergo extracranial and transcranial Color-Coded Duplex (TCCD) ultrasound examinations to detect presence and severity of extra and intracranial atherosclerosis. Intracranial stenoses will be assessed by magnetic resonance angiography (MRA). Clinical and demographic variables will be recorded and blood samples will be drawn to investigate clinical, biological and genetic factors associated with the presence of ASIA. A long-term clinical and sonographic follow-up will be conducted thereafter to identify predictors of disease progression and of incident vascular events. DISCUSSION: The Barcelona-ASIA is a population-based study aiming to evaluate the prevalence and clinical importance of asymptomatic intracranial large-artery atherosclerosis in Caucasians. The ASIA project may provide a unique scientific resource to better understand the dynamics of intracranial atherosclerosis from its early stages and to identify new potential therapeutic targets for this condition.

Rat CCl(4)-induced cirrhosis plus total portal vein ligation: a new model for the study of hyperammonaemia and brain oedema.

INTRODUCTION: Animal models used to study hyperammonaemic disorders related to chronic liver disease are unsatisfactory. These animals only develop hyperammonaemia and brain oedema when fed with diets supplemented with amonium acetate. AIM: To develop a novel experimental model of hyperammonaemia and brain oedema in CCl(4)-induced cirrhosis in rats. METHODS: Four groups were studied: rats with sham intervention (S), rats with total portal vein ligation (TPVL), cirrhotic rats (LC), and cirrhotic rats with TPVL (LC+TPVL). When ascites was diagnosed, oral glutamine challenge (OGC) test was performed. Blood, liver, lungs and brain samples were collected to quantify liver function parameters, plasmatic and cerebral ammonia, endotoxaemia, liver and brain histology, brain oedema and portosystemic shunting degree. RESULTS: LC+TPVL rats showed a significant increase in portosystemic shunting when compared with LC group and a significant derangement in liver function when compared with TPVL group. These alterations resulted in a significant increase in plasmatic and brain ammonia concentrations and a higher plasmatic endotoxaemia as compared with others. Similarly, the area under OGC curve was significantly increased in LC+TPVL group as compared with the others, and correlates with portal shunting. Low-grade brain oedema was only observed in LC+TPVL group. All cirrhotic groups showed liver regeneration nodules and type-II Alzheimer astrocytes CONCLUSION: LC+TPVL reproduce the main alterations - portosystemic shunting, plasmatic and cerebral hyperammonaemia and low-grade brain oedema - observed in cirrhotic patients with hepatic encephalopathy.

[Biomarkers for detection and prediction in acute coronary syndrome]. / Biomarcadores de detección y predicción de síndrome coronario agudo.

Diagnosis of patients with suggestive symptoms of acute coronary syndrome (ACS), in an emergency department, is problematic. Troponine or CKMB are the gold standard biochemical markers to diagnose the ACS, and the clinical practice guidelines of the various scientific societies recommend their use with the best available evidence. Other biomarkers such as myoglobin, hs-PCR and natriuretic peptides, support the diagnosis of ACS although its recognition in clinical practice guidelines has a lower level of evidence. New biomarkers with sufficient reliability would be necessary to anticipate the clinical presentation of the entity. There are biomarkers such as inflammatory cytokines, cellular adhesion molecules, acute-phase reactants, plaque destabilization and rupture biomarkers, markers of myocardial ischemia and stretch, that may provide earlier assessment of the overall risk of the patient and help identify future events. Possibly, its clinical use would decrease the number of consultations in the emergency department and help prevent future adverse effects. The objective of this review is to study the potential clinical utility of new biomarkers of risk stratification in patients with ACS, as well as deepen the knowledge of the pathophysiology of this syndrome.

Immortalized human skin fibroblast feeder cells support growth and maintenance of both human embryonic and induced pluripotent stem cells.

BACKGROUND: Feeder cells are frequently used for the early-stage of derivation and culture of human embryonic stem cell (hESC) lines. METHODS: We established a conditionally immortalized human foreskin fibroblast line that secreted basic fibroblast growth factor (bFGF). These cells were used as feeder cells for hESC culture and induced pluripotent stem (iPS) cell derivation and expansion. This conditional immortalization was performed using lentiviral vector (LV) mediated transduction of Bmi-1 and human telomerase reverse transcriptase genes and the resulting cell line was further modified by LV-mediated transduction of a secreted form of bFGF gene product. Three different laboratories have tested whether this feeder cell line could support the maintenance of four different hESC lines. RESULTS: Immortalized fibroblasts secreting stable amounts of bFGF supported the growth of all hESC lines, which remained pluripotent and had a normal karyotype for at least 10 passages. Even at high passage (p56), these modified cells, when used as feeders, could support iPS derivation and propagation. Derived iPS cells expressed pluripotency markers, had hESC morphology and produced tissue components of the three germ layers when differentiated in vitro. CONCLUSION: These modified fibroblasts are useful as a genetically-defined feeder cell line for reproducible and cost-effective culture of both hESC and iPS cells.

Efficient method for slow cryopreservation of human embryonic stem cells in xeno-free conditions.

An effective, consistent and xeno-free cryopreservation technique is crucial for any human embryonic stem cell (hESC) laboratory with future perspectives for clinical application. This study presents a new slow freezing-rapid thawing method in serum-free conditions that allows the cryopreservation of a large number of colonies without the use of a programmable freezer. To test its efficacy, this method has been compared with two established vitrification methods and applied to three different hESC lines (H9, VAL-3 and VAL-5). The method is based on an increasing concentration of dimethylsulphoxide (1.0, 1.2, 1.5 and 2.0 mol/l) with a slow or a rapid cooling system. Using this method, approximately 60 colonies per cryovial could be cryopreserved, the survival rate ranged between 15 and 68% depending on the cell line used, and the majority of the surviving colonies were grade A. Post-cryopreserved hESC have been cultured for 20 passages, re-cryopreserved and re-thawed with consistent results. After thawing, cells retained the inherent undifferentiated characteristics of hESC and growth rate curve, with a stable karyotype, telomerase activity and teratoma formation when injected into severe combined immunodeficient animals, which was comparable with the fresh lines. This method has been tested for 3 years in two different laboratories.

[Asymmetric dimethylarginine as cardiovascular risk factor]. / Dimetilarginina asimétrica como marcador de riesgo cardiovascular.

The amino acid L-arginine is the substrate for endothelial nitric oxide synthesis. The endothelium is capable of producing asymmetric dimethylargine (ADMA) (L-arginine methylated). ADMA is able to compete with L-arginine in nitric oxide (NO) production and inhibits oxide nitric synthase activity. Elevated blood levels of ADMA can block the synthesis of NO, and induce endothelial dysfunction, which may lead to the initiation and progression of atherosclerosic vascular disease. Prospective clinical studies in different patients populations suggest that ADMA is a new marker in cardiovascular disease and is to able to predict new cardiovascular events. Recently, intraindividual variations of ADMA in healthy subjects have been described. This fact induces to continue studying the diagnosis and prognosis value of this potential and novel marker of cardiovascular risk.