Homocysteine and lipoprotein (a) correlation in ischemic stroke patients

Relationship between carotid atherosclerosis and lipoprotein (a) in patients with acute ischemic stroke

Objective

This study aimed to examine the relationship between lipoprotein (a) (Lp[a]) and other blood lipid indexes and carotid artery atherosclerosis in patients with acute ischemic stroke (AIS).

Methods

A total of 2,018 patients were selected from the hospital "acute stroke intervention and secondary prevention registration database" by identifying blood fat indexes (cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and Lp[a]). Based on the results of carotid artery ultrasound examinations, the patients were divided into a "no plaque" group, comprising 400 patients, a "plaque and no stenosis" group, comprising 1,122 patients and a "carotid stenosis" group, comprising 496 patients. The relationship between Lp(a) and blood lipid indexes and carotid artery atherosclerosis was then investigated using multi-factor logistics regression analysis.

Results

There were 400 patients (19.8%) with no carotid plaque, 1,122 patients (55.6%) with plaque and no carotid stenosis and 496 patients (24.6%) with carotid stenosis. As the degree of carotid artery atherosclerosis increased, the Lp(a) level gradually increased; Lp(a) and cholesterol were identified as independent risk factors for carotid atherosclerosis.

Conclusion

Lipoprotein (a) and cholesterol are independent risk factors for patients with AIS with carotid atherosclerosis, and their levels increase with the degree of carotid artery atherosclerosis; therefore, attention should focus on levels of cholesterol and Lp(a) in acute stroke patients to control atherosclerosis effectively.

Unveiling the role of disulfidptosis-related genes in the pathogenesis of non-alcoholic fatty liver disease

Backgrounds

Non-alcoholic fatty liver disease (NAFLD) presents as a common liver disease characterized by an indistinct pathogenesis. Disulfidptosis is a recently identified mode of cell death. This study aimed to investigate the potential role of disulfidptosis-related genes (DRGs) in the pathogenesis of NAFLD.

Methods

Gene expression profiles were obtained from the bulk RNA dataset GSE126848 and the single-cell RNA dataset GSE136103, both associated with NAFLD. Our study assessed the expression of DRGs in NAFLD and normal tissues. Weighted gene co-expression network analysis (WGCNA) and differential expression analysis were employed to identify the key NAFLD-specific differentially expressed DRGs (DE-DRGs). To explore the biological functions and immune regulatory roles of these key DE-DRGs, we conducted immune infiltration analysis, functional enrichment analysis, consensus clustering analysis, and single-cell differential state analysis. Finally, we validated the expression and biological functions of DRGs in NAFLD patients using histology and RNA-sequencing transcriptomic assays with human liver tissue samples.

Results

Through the intersection of WGCNA, differentially expressed genes, and DRGs, two key DE-DRGs (DSTN and MYL6) were identified. Immune infiltration analysis indicated a higher proportion of macrophages, T cells, and resting dendritic cells in NAFLD compared to control liver samples. Based on the key DE-DRGs, Two disulfidptosis clusters were defined in GSE126848. Cluster 1, with higher expression of the key DE-DRGs, exhibited increased immune infiltration abundance and was closely associated with oxidative stress and immune regulation compared to cluster 2. High-resolution analysis of mononuclear phagocytes highlighted the potential role of MYL6 in intrahepatic M1 phenotype Kupffer cells in NAFLD patients. Our transcriptome data revealed that the expression levels of the majority of DRGs were significantly increased in NAFLD patients. NAFLD patients exhibit elevated MYL6 correlating with inflammation, oxidative stress, and disease severity, offering promising diagnostic specificity.

Conclusion

This comprehensive study provides evidence for the association between NAFLD and disulfidptosis, identifying potential target genes and pathways in NAFLD. The identification of MYL6 as a possible treatment target for NAFLD provided a novel understanding of the disease's development.

Equivalent Response Strategy for Sensing Total Biothiols in Human Serums and Living Cells Using a Hemicyanine-Based Self-Immolative Probe

Biothiols including cysteine (Cys), homocysteine (Hcy), and glutathione (GSH) are crucial in maintaining the redox balance in the body, and the metabolism and transportation of biothiols rely on the coreaction of diverse proteins and enzymes. The abnormal concentrations and metabolism of biothiols are closely associated with many diseases. However, due to the same active reaction site of the sulfydryl group in biothiols, it is inevitable to bear a confused signal of mutual influence on both nonselective detection and discriminate detection, which presents a serious challenge of accurately sensing or imaging the three biothiols. By assigning an α,β-unsaturated ketone moiety as a Michael acceptor to trigger thiols to complete the irreversible equivalent domino response processes of nucleophilic addition, olefinic bond migration, and self-immolation, a targeted strategy was rationally pointed out, and herein, a hemicyanine-based probe CyOCy was prepared as a proof of strategy demonstration. The new probe could be equivalently lit up by Cys, Hcy, GSH, and even biothiol combinations (Cys/Hcy, Cys/GSH, Hcy/GSH, or Cys/Hcy/GSH) with unified linear ranges, detection limits, and response times. The probe CyOCy has been successfully used for the accurate quantification of total biothiols in the serum samples of healthy persons and coronary heart disease patients. In addition, the probe has been applied for cell screening, exogenous biothiol imaging, and monitoring drug-induced biothiol fluctuations. The purposive thinking of this work may provide an effective avenue for the accurate sensing of multicomponent samples.

Identification and validation of disulfidptosis-associated molecular clusters in non-alcoholic fatty liver disease

Objective: Non-alcoholic fatty liver disease (NAFLD) is the most prevalent liver disease in the world, and its pathogenesis is not fully understood. Disulfidptosis is the most recently reported form of cell death and may be associated with NAFLD progression. Our study aimed to explore the molecular clusters associated with disulfidptosis in NAFLD and to construct a predictive model. Methods: First, we analyzed the expression profile of the disulfidptosis regulators and immune characteristics in NAFLD. Using 104 NAFLD samples, we investigated molecular clusters based on differentially expressed disulfidptosis-related genes, along with the related immune cell infiltration. Cluster-specific differentially expressed genes were then identified by using the WGCNA method. We also evaluated the performance of four machine learning models before choosing the optimal machine model for diagnosis. Nomogram, calibration curves, decision curve analysis, and external datasets were used to confirm the prediction effectiveness. Finally, the expression levels of the biomarkers were assessed in a mouse model of a high-fat diet. Results: Two differentially expressed DRGs were identified between healthy and NAFLD patients. We revealed the expression profile of DRGs in NAFLD and the correlation with 22 immune cells. In NAFLD, two clusters of molecules connected to disulfidptosis were defined. Significant immunological heterogeneity was shown by immune infiltration analysis among the various clusters. A significant amount of immunological infiltration was seen in Cluster 1. Functional analysis revealed that Cluster 1 differentially expressed genes were strongly linked to energy metabolism and immune control. The highest discriminatory performance was demonstrated by the SVM model, which had a higher area under the curve, relatively small residual and root mean square errors. Nomograms, calibration curves, and decision curve analyses were used to show how accurate the prediction of NAFLD was. Further analysis revealed that the expression of three model-related genes was significantly associated with the level of multiple immune cells. In animal experiments, the expression trends of DDO, FRK and TMEM19 were consistent with the results of bioinformatics analysis. Conclusion: This study systematically elucidated the complex relationship between disulfidptosis and NAFLD and developed a promising predictive model to assess the risk of disease in patients with disulfidptosis subtypes and NAFLD.

Homocysteine is associated with higher risks of ischemic stroke: A systematic review and meta-analysis

BACKGROUND

High levels of homocysteine (Hct) have been associated with great risks of ischemic stroke. However, some controversy still exists. We performed a systematic review and meta-analysis to compare the levels of Hct between patients with ischemic stroke and controls.

METHODS

We performed a systematic literature search for articles reporting Hct levels of patients with occurrence of ischemic stroke. We employed a random-effects inverse-variance weighted meta-analytical approach in order to pool standardized mean differences, with estimation of τ2 through the DerSimonian-Laird method.

RESULTS

The initial search yielded 1361 studies. After careful analysis of abstracts and full texts, the meta-analysis included data from 38 studies, which involved almost 16 000 stroke events. However, only 13 studies reported means and standard deviations for cases and controls, and therefore were used in the meta-analysis. Those studies presented data from 5002 patients with stroke and 4945 controls. Standardized mean difference was 1.67 (95% CI 1.00-2.25, P < 0.01), indicating that Hct levels were significantly larger in patients with ischemic stroke compared to controls. Between-study heterogeneity was very large (I2 = 99%), particularly because three studies showed significantly large mean differences.

CONCLUSION

This meta-analysis shows that patients with ischemic stroke have higher levels of Hct compared to controls. Whether this is a modifiable risk factor remains to be assessed through larger prospective cohorts.

Association of Paraoxonase-2 (C1053G) Gene Polymorphism with the Expression of Paraoxonase-2 Gene in Patients of Ischemic Stroke - A Pilot Study in Indian Population

Background and Objective

Oxidative stress plays an important role in atherosclerosis and ischemic stroke. Due to antioxidant properties of Paraoxonase-2, we studied the implication of Paraoxonase-2 gene polymorphism (C1053G) on expression of Paraoxonase-2 gene at mRNA level in ischemic stroke patients.

Material and Methods

40 patients of ischemic stroke and 40 age and sex-matched controls were included. Paraoxonase-2 genotypes were evaluated by Polymerase Chain Reaction and Restriction Fragment Length Polymorphism and expression of Paraoxonase-2 gene at mRNA level was determined by quantitative real time Polymerase Chain Reaction analysed as delta-CT (△CT).

Result and Discussion

The observed allele frequencies in patients for C and G allele were 0.61 and 0.39 respectively, and were 0.72 and 0.28 in control group. No significant association was found in C allele of C1053G polymorphism and ischemic stroke. The average △ CT value is significantly (p = 0.0001) higher in patients group (7.68 ± 2.0) as compared to controls (5.70 ± 1.8). We found a significant difference in the average delta-CT value (p = 0.0001), wherein down-regulated paraoxonase-2 gene expression (approximately 0.25 fold) was observed in case of patients as compared to controls. Down-regulated expression of paraoxonase-2 gene was observed in patients with GG genotype as compared to CG and CC genotypes in patients with ischemic stroke (p = 0.0001).

Conclusion

Down-regulated Paraoxonase-2 gene expression, as evidenced by low mRNA levels in GG genotype may be one of the contributory factors in the progression of ischemic stroke.

Lipoprotein (a) level as a risk factor for stroke and its subtype: A systematic review and meta-analysis

The role of lipoprotein-A [Lp (a)] as a risk factor for stroke is less well documented than for coronary heart disease. Hence, we conducted a systematic review and meta-analysis for the published observational studies in order to investigate the association of Lp (a) levels with the risk of stroke and its subtypes. In our meta-analysis, 41 studies involving 7874 ischemic stroke (IS) patients and 32,138 controls; 13 studies for the IS subtypes based on TOAST classification and 7 studies with 871 Intracerebral hemorrhage (ICH) cases and 2865 control subjects were included. A significant association between increased levels of Lp (a) and risk of IS as compared to control subjects was observed (standardized mean difference (SMD) 0.76; 95% confidence interval (CIs) 0.53-0.99). Lp (a) levels were also found to be significantly associated with the risk of large artery atherosclerosis (LAA) subtype of IS (SMD 0.68; 95% CI 0.01-1.34) as well as significantly associated with the risk of ICH (SMD 0.65; 95% CI 0.13-1.17) as compared to controls. Increased Lp (a) levels could be considered as a predictive marker for identifying individuals who are at risk of developing IS, LAA and ICH.

Endothelial Nitric Oxide Synthase (Glu298Asp) Polymorphism is Associated Significantly with Ischemic Stroke Presenting with Seizures and Altered Sensorium

Background

Endothelial nitric oxide synthase (eNOS) is an enzymatic marker whose genetic polymorphism might predispose to acute ischemic stroke (AIS) via vascular endothelial dysfunction. It has a potential role in atherosclerosis, making it a plausible risk factor for stroke. Prior studies have failed to prove a conclusive relationship between eNOS polymorphism and AIS.

Objective

The aim of this study is to find an association between the presence of eNOS polymorphism (Glu298Asp) and the risk of developing AIS.

Materials and Methods

We recruited 307 subjects including 153 AIS cases and 154 healthy controls. The eNOS (Glu298Asp) polymorphism was identified in EDTA blood by PCR amplification of the target region followed by restriction enzyme digestion, and genotyping on Agarose gel. GG, GT and TT genotypes were obtained. Statistical analysis was done using SPSS software version 20.

Results

A significant association was found between the presence of TT genotype and the risk of AIS (Odd's ratio (OR): 2.43, P-value = 0.038). There was no significant association between the TT genotype and the traditional stroke risk factors. However, the TT genotype was significantly associated with the presence of altered consciousness (OR: 5.27, 95% CI: 1.59-17.04, P-value = 0.003) and with the occurrence of seizures at presentation (OR: 7.98, 95% CI: 1.99-32.09, P-value = 0.007).

Conclusions

There is a significant association between the presence of eNOSpolymorphism (Glu298Asp) and the risk of AIS, and the TT genotype may predispose to a more severe initial presentation of ischemic stroke.

The role of B vitamins in stroke prevention

Elevated plasma levels of homocysteine (Hcy) are a recognized risk factor for stroke. This relationship represents one aspect of the debated `Hcy hypothesis'. Elevated Hcy may be an independent and treatable cause of atherosclerosis and thrombotic vascular diseases. Further observations indicate that proper dietary supplementation with B-vitamins decreases total plasma Hcy concentrations and may be an effective intervention for stroke prevention. Metabolic vitamin B₁₂ deficiency is a nutritional determinant of total Hcy and stroke risk. Genetic factors may link B vitamins with stroke severity due to the impact on Hcy metabolism of polymorphism in the genes coding for methylenetetrahydrofolate reductase, methionine-synthase, methionine synthase reductase, and cystathionine β-synthase. Several meta-analyses of large randomized controlled trials exist. However, they are not completely in agreement about B vitamins' role, particularly folic acid levels, vitamin B₁₂, and B₆, in lowering the homocysteine concentrations in people at high stroke risk. A very complex relationship exists between Hcy and B vitamins, and several factors appear to modify the preventive effects of B vitamins in stroke. This review highlights the regulating factors of the active role of B vitamins active in stroke prevention. Also, inputs for further large, well-designed studies, for specific, particularly sensitive subgroups are given.

A prospective cohort study of MTHFR C677T gene polymorphism and its influence on the therapeutic effect of homocysteine in stroke patients with hyperhomocysteinemia

BACKGROUND

Hyperhomocysteinemia (HHCY) is a risk factor for cardiovascular and cerebrovascular diseases. The C677T 5, 10-methylenetetrahydrofolate reductase (MTHFR) gene polymorphism increases homocysteine (HCY) levels. This study analyzed the relationship between C677T MTHFR polymorphism and the therapeutic effect of lowering HCY in stroke patients with HHCY.

METHODS

Baseline data were collected from stroke patients with HHCY for this prospective cohort study. The C677T MTHFR genotype was detected by polymerase chain reaction-restriction fragment length polymorphism and the therapeutic effect to reduce HCY was compared.

RESULTS

Of 200 stroke patients 162 (81.0%) completed follow-up and were evaluated. Most of them responded well to treatment (103 cases, 63.5%), but 59 (36.4%) patients were in the poor efficacy group. There was a significant difference in terms of age (P < 0.001), hypertension (P = 0.041), hyperuricemia (P = 0.042), HCY after treatment (P < 0.001), and MTHFR genotype (P < 0.001) between the poor efficacy and effective groups, with increased frequency of the TT genotype in the poor efficacy group. Logistic regression showed that the T allele was associated with poor efficacy (OR = 0.733, 95%CI: 0.693, 0.862, P < 0.001). In the codominant model the TT genotype was associated with poor outcome (OR = 0.862, 95%CI: 0.767, 0.970, P = 0.017) and this was also the case in the recessive model (OR = 0.585, 95%CI: 0.462, 0.741, P < 0.001) but there was no association between CT and TT in the dominant model.

CONCLUSIONS

The T allele and TT genotype of the MTHFR C677T polymorphism was associated with poor HCY reduction treatment efficacy in stroke patients with HHCY.

TRIAL REGISTRATION

The registration number of the clinical trial is ChiCTR1800020048. Registration date: December 12, 2018.

Association between smoking status and homocysteine levels and possible effect modification by cholesterol and oestradiol

Introduction: This study aimed to examine the association of smoking status with homocysteine levels and to determine whether the association is modified by oestradiol or cholesterol.Methods: Data (N = 4580) were obtained from National Health and Nutrition Examination Survey 2003-2004 with analysis done in 2018 on adults aged ≥20 years. The outcome was homocysteine; smoking status was the exposure variable and categorized as current, former or never smoker. Generalized linear models were used to examine the associations between smoking status and homocysteine levels, while assessing the impact of oestradiol and cholesterol.Results: After adjusting for age, sex, ethnicity, education and income level, homocysteine levels did differ by smoking status ((current smokers versus never smokers: β: 0.18 CI: 0.00, 0.36), (former smokers: β: 0.10 CI: -0.09, 0.28)). The addition of oestradiol as an interaction term in adjusted models was associated with a 16.6% increase in homocysteine levels when compared to models without the interaction term. Oestradiol but not cholesterol did moderate the association between smoking status and homocysteine levels.Discussion and conclusions: Homocysteine levels did differ across smoking status after adjusting for confounders. Oestradiol did moderate the relationship between homocysteine and smoking status.

Lipoprotein(a): An underrecognized genetic risk factor for malignant coronary artery disease in young Indians

Malignant coronary artery disease (CAD) refers to a severe and extensive atherosclerotic process involving multiple coronary arteries in young individuals (aged <45 years in men and <50 years in women) with a low or no burden of established risk factors. Indians, in general, develop acute myocardial infarction (AMI) about 10 years earlier; AMI rates are threefold to fivefold higher in young Indians than in other populations. Although established CAD risk factors have a predictive value, they do not fully account for the excessive burden of CAD in young Indians. Lipoprotein(a) (Lp(a)) is increasingly recognized as the strongest known genetic risk factor for premature CAD, with high levels observed in Indians with malignant CAD. High Lp(a) levels confer a twofold to threefold risk of CAD-a risk similar to that of established risk factors, including diabetes. South Asians have the second highest Lp(a) levels and the highest risk of AMI from the elevated levels, more than double the risk observed in people of European descent. Approximately 25% of Indians and other South Asians have elevated Lp(a) levels (≥50 mg/dl), rendering Lp(a) a risk factor of great importance, similar to or surpassing diabetes. Lp(a) measurement is ready for clinical use and should be an essential part of all CAD research in Indians.

Lipoprotein (a) as a risk factor for ischemic stroke: a meta-analysis

OBJECTIVE

Lipoprotein (a) [Lp(a)] harbors atherogenic potential but its role as a risk factor for ischemic stroke remains controversial. We conducted a meta-analysis to determine the relative strength of the association between Lp(a) and ischemic stroke and identify potential subgroup-specific risk differences.

METHODS

A systematic search using the MeSH terms "lipoproteins" OR "lipoprotein a" AND "stroke" was performed in PubMed and ScienceDirect for case-control studies from June 2006 and prospective cohort studies from April 2009 until December 20th 2014. Data from eligible papers published before these dates were reviewed and extracted from previous meta-analyses. Studies that assessed the relationship between Lp(a) levels and ischemic stroke and reported generic data-i.e. odds ratio [OR], hazard ratio, or risk ratio [RR]-were eligible for inclusion. Studies that not distinguish between ischemic and hemorrhagic stroke and transient ischemic attack were excluded. Random effects meta-analyses with mixed-effects meta-regression were performed by pooling adjusted OR or RR.

RESULTS

A total of 20 articles comprising 90,904 subjects and 5029 stroke events were eligible for the meta-analysis. Comparing high with low Lp(a) levels, the pooled estimated OR was 1.41 (95% CI, 1.26-1.57) for case-control studies (n = 11) and the pooled estimated RR was 1.29 (95% CI, 1.06-1.58) for prospective studies (n = 9). Sex-specific differences in RR were inconsistent between case-control and prospective studies. Study populations with a mean age of ≤55 years had an increased RR compared to older study populations. Reported Lp(a) contrast levels and ischemic stroke subtype significantly contributed to the heterogeneity observed in the analyses.

CONCLUSION

Elevated Lp(a) is an independent risk factor for ischemic stroke and may be especially relevant for young stroke patients. Sex-specific risk differences remain conflicting. Further studies in these subgroups may be warranted.

Metabolic interactions between hyperhomocysteinemia and endothelin-1 among Tunisian patients with acute coronary diseases

BACKGROUND

Acute coronary syndromes (ACS) are complex and polygenic diseases which are a real problem of public health. These syndromes require multidisciplinary studies to understand the pathogenesis mechanisms and metabolic interactions between different risk factors.This study aimed to explore the variation of two coronary risk parameters not mentioned by Framingham cohorts, hyperhomocysteinemia and endothelin-1 (ET-1) in Tunisian coronary and the study of the variation of these parameters based on various cardiac risk factors and metabolic relationship between them.To 157 coronary and 142 healthy subjects, the concentration of homocysteine was quantified by fluorescence polarization immunoassay; the concentration of ET-1 was measured by an analytical technique, the High Performance Liquid Chromatography (HPLC) coupled with mass spectrometry.

RESULTS

Our study showed that homocysteine and ET-1 were significantly higher in patients compared to healthy subjects (24.40 ± 12.5 μmol/L vs 7.44 ± 2.5 μmol/L p <0.00001) for homocysteine and (15.2 ± 5.3 nmol/L vs 7.1 ± 2.7 nmol/L, p <0.00001) for ET-1. On the other hand, homocysteine varies according to tobacco and diabetes while ET-1 depends on the sex, hypertension, smoking, obesity and dyslipidemia and a statistically negative correlation was shown between homocysteine and ET-1 in coronary patients (r = -0.66 p <0.00001).

CONCLUSION

The study of the variation of these two parameters in coronary patients and metabolic exploration of the relationship between homocysteine and ET-1 according to various risk factors and the interactions between themselves facilitates the decision of therapeutic treatment.

Association between the methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism and ischemic stroke in the Chinese population: a meta-analysis

PURPOSE

The association between the methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism and ischemic stroke (IS) has been extensively studied; however, the results from genetic association studies have been inconsistent even in the Chinese population. As far as we know, there was no previous meta-analysis concerning this association in the Chinese population. Therefore, the aim of our meta-analysis was to further evaluate the association in the Chinese population.

METHODS

We collected all of the relevant studies from Pubmed, OVID, Embase, Chinese Wan Fang database, CNKI, Chongqing VIP database and CBM up to August 2014. The available data was analyzed by Stata (version 12.0). We used odds ratios (ORs) and corresponding 95% confidence intervals (CIs) to present the strength of the association. Heterogeneity was evaluated by the Q-test and I(2) statistic. Different genetic models, subgroup analysis, publication bias and sensitivity analysis were used to improve the comprehensive understanding.

RESULTS

The results showed a significant association between the MTHFR gene C677T polymorphism and IS in six genetic models (additive model: OR = 1.34, 95%CI: 1.17 ∼ 1.54, p < 0.001; dominant model: OR = 1.44, 95% CI:1.26 ∼ 1.64, p < 0.001; recessive model: OR = 1.45, 95% CI: 1.15 ∼ 1.83, p = 0.001; heterozygote model: OR = 1.35, 95% CI: 1.18 ∼ 1.55, p < 0.001; homozygote model: OR = 1.80, 95% CI: 1.34 ∼ 2.41, p < 0.001; and allelic model: OR = 1.34, 95% CI: 1.17 ∼ 1.53, p < 0.001) based on the overall population, as well as subgroup analysis. In addition, the similar results were obtained in the sensitivity analysis based on studies with the high quality.

CONCLUSIONS

This meta-analysis presented a significant association between the MTHFR gene C677T polymorphism and IS, the T allele might be a risk factor for IS in the Chinese population.

Prognostic value of serum lipoprotein(a) levels in patients with acute ischemic stroke

Inflammation plays a crucial role in the pathogenesis and prognosis of stroke. This study aims to investigate the relationship between acute ischemic stroke (AIS) and lipoprotein(a) [Lp(a)] levels and to determine the prognosis value of Lp(a) to predict the functional outcome. A total of 153 patients with AIS and 120 controls were included in the study. Serum Lp(a) levels were examined in both groups. Severity of the stroke was assessed using the National Institutes of Health Stroke Scale. The modified Rankin Scale scores at discharge were determined to establish the prognosis of stroke patients. The prognostic value of Lp(a) to predict the functional outcome within the time of discharge was analyzed by logistic regression analysis, after adjusting for the possible confounders. The results indicated that the serum Lp(a) levels were significantly higher in AIS patients as compared with normal controls [303 {interquartile range (IQR) 170-529 mg/l} and 144 (IQR 66-252 mg/l), respectively; P=0.000]. In the 52 patients with an unfavorable functional outcome, serum Lp(a) levels were higher compared with those in patients with a favorable outcome [213 (IQR 143-347 mg/l) and 559 (IQR 357-845 mg/l), respectively; P=0.000]. In multivariate analysis, there was an increased risk of unfavorable outcome associated with Lp(a) levels 300 mg/l or more (odds ratio 3.12; 95% confidence interval 1.55-5.28; P=0.001) after adjusting for possible confounders. Serum Lp(a) can be considered as an independent short-term prognostic marker of functional outcome in Chinese patients with AIS even after correcting for possible confounding factors.

Analytical methods involving separation techniques for determination of low-molecular-weight biothiols in human plasma and blood

Low-molecular-weight biothiols such as homocysteine, cysteine, and glutathione are metabolites of the sulfur cycle and play important roles in biological processes such as the antioxidant defense network, methionine cycle, and protein synthesis. Thiol concentrations in human plasma and blood are related to diseases such as cardiovascular disease, neurodegenerative disease, and cancer. The concentrations of homocysteine, cysteine, and glutathione in plasma samples from healthy human subjects are approximately in the range of 5-15, 200-300, and 1-5 μM, respectively. Glutathione concentration in the whole blood is in the millimolar range. Measurement of biothiol levels in plasma and blood is thought to be important for understanding the physiological roles and biomarkers for certain diseases. This review summarizes the relationship of biothiols with certain disease as well as pre-analytical treatment and analytical methods for determination of biothiols in human plasma and blood by using high-performance liquid chromatography and capillary electrophoresis coupled with ultraviolet, fluorescence, or chemiluminescence detection; or mass spectrometry.

Detailed analysis of gene polymorphisms associated with ischemic stroke in South Asians

The burden of stroke is disproportionately high in the South Asian subcontinent with South Asian ethnicity conferring a greater risk of ischemic stroke than European ancestry regardless of country inhabited. While genes associated with stroke in European populations have been investigated, they remain largely unknown in South Asians. We conducted a comprehensive meta-analysis of known genetic polymorphisms associated with South Asian ischemic stroke, and compared effect size of the MTHFR C677T-stroke association with effect sizes predicted from homocysteine-stroke association. Electronic databases were searched up to August 2012 for published case control studies investigating genetic polymorphisms associated with ischemic stroke in South Asians. Pooled odds ratios (OR) for each gene-disease association were calculated using a random-effects model. We identified 26 studies (approximately 2529 stroke cases and 2881 controls) interrogating 33 independent genetic polymorphisms in 22 genes. Ten studies described MTHFR C677T (108 with TT genotype and 2018 with CC genotype) -homocysteine relationship and six studies (735 stroke cases and 713 controls) described homocysteine-ischemic stroke relationship. Risk association ORs were calculated for ACE I/D (OR 5.00; 95% CI, 1.17–21.37; p = 0.03), PDE4D SNP 83 (OR 2.20; 95% CI 1.21–3.99; p = 0.01), PDE4D SNP 32 (OR 1.57; 95% CI 1.01–2.45, p = 0.045) and IL10 G1082A (OR 1.44; 95% CI, 1.09–1.91, p = 0.01). Significant association was observed between elevated plasma homocysteine levels and MTHFR/677 TT genotypes in healthy South Asians (Mean difference (ΔX) 5.18 µmol/L; 95% CI 2.03–8.34: p = 0.001). Our results demonstrate that the genetic etiology of ischemic stroke in South Asians is broadly similar to the risk conferred in Europeans, although the dataset is considerably smaller and warrants the same clinical considerations for risk profiling.

Lipoprotein(a), ferritin, and albumin in acute phase reaction predicts severity and mortality of acute ischemic stroke in North Indian Patients

BACKGROUND

Inflammation plays a crucial role in the pathogenesis and prognosis of stroke. We studied the behavior of lipoprotein(a) [Lp(a)], ferritin, and albumin as acute phase reactants and their roles in the severity and mortality of stroke.

METHODS

We recruited 100 consecutive patients with acute ischemic stroke and 120 controls. Blood samples were drawn on days 1 and 7 and at both 3 and 6 months. Stroke was classified using Trial of Org 10172 in Acute Stroke Treatment classification. Stroke severity was assessed using the National Institutes of Health Stroke Scale. Prognosis at 6 months was assessed using the modified Rankin Scale, and mortality was assessed using the Kaplan-Meier analysis. Serum levels of interleukin-6 (IL-6), Lp(a), ferritin, and albumin were measured using enzyme-linked immunosorbent assay, immunoturbidimetry, and chemiluminescence commercial kits, respectively.

RESULTS

Levels of IL-6, Lp(a), and ferritin were consistently higher among cases than controls (P < .0001). Serum Lp(a) levels peaked at day 7 after stroke and tapered thereafter. Albumin levels were lower than controls on admission day and increased subsequently. In our study, Lp(a) acted as an acute phase reactant while albumin acted as a negative acute phase reactant. There was no association between Trial of Org 10172 in Acute Stroke Treatment subtype and elevated serum levels of Lp(a), albumin, and ferritin. Lp(a) and ferritin were high in patients with severe stroke. Albumin was negatively correlated with stroke severity. Serum levels of Lp(a) ≥ 77 mg/dL, albumin ≤ 3.5 g/dL, and ferritin ≥ 370 ng/dL is associated with a significantly increased risk of having a poorer outcome in stroke. Serum levels of Lp(a) >77 mg/dL and albumin <3.5 g/dL were also associated with increased mortality.

CONCLUSIONS

High levels of Lp(a) and ferritin and low levels of albumin are associated with increased severity and poorer long term prognosis of stroke. Patients with admission levels of Lp(a) >77 mg/dL and albumin <3.5 g/dL had increased mortality.

Mitochondrial mitophagic mechanisms of myocardial matrix metabolism and remodelling

High levels of homocysteine (Hcy), known as hyperhomocysteinmia (HHcy), are correlated with an increase in extracellular matrix remodelling (ECM) via the matrix metalloproteinases (MMPs) and plasminogen/plasmin system. This results in an increase deposition of collagen that leads to endothelial-myocyte (EM) and myocyte-myocyte (MM) uncoupling; the physiological consequences are a plethora of cardiovascular pathologies. Homocysteine-induced increase in intracellular and mitochondrial Ca(2+) plays an important role in increasing reactive oxygen species (ROS) within mitochondria and instigating mitophagy within the cell. This occurs via several Hcy-mitigated processes: agonizing N-methyl-d-aspartate receptor-1 (NMDA-R1), decreasing expression of peroxisome proliferator activator receptor (PPAR) [thereby increasing oxidation], impairing Ca(2+) handling via Na(+)/Ca(2+) exchanger (NCX1) and Sarco endoplasmic reticulum Ca(2+) ATPase (SERCA-2a). The end result is an increase in ROS that directly or indirectly lead to MMP activation within mitochondria or the cytoplasm. Hcy induces a mitochondrial permeability transition that allows MMPs to be released from mitochondria thereby metabolizing matrix and impairing cardiac function. Further work remains to be elucidated concerning the specific mitochondrial mitophagic mechanisms under which matrix metabolism and remodelling occurs. Moreover, the therapeutic implications of NMDA and PPAR ligands are some promise to patient.

Interaction between homocysteine and lipoprotein(a) increases the prevalence of coronary artery disease/myocardial infarction in women: a case-control study

INTRODUCTION

Our aim was to investigate the association of elevated homocysteine (Hcy) and lipoprotein(a) Lp(a) with the prevalence of coronary artery disease (CAD) and myocardial infarction (MI) and to investigate their interaction in both genders.

MATERIALS AND METHODS

955 (male/female: 578/377) consecutive patients admitted for coronary angiography were enrolled in the study. Lp(a), Hcy, vitamin B12, folic acid, MTHFR C677T polymorphism and traditional risk factors were determined.

RESULTS

619 patients had significant (≥50%) stenosis (CAD+) and 341 had MI (MI+). CAD-MI- cases (n=302) were considered as controls. Adjusted Hcy levels were significantly elevated only in the female CAD+MI+group that was related to decreased vitamin B12 levels. Lp(a) was elevated in the CAD+MI+group of both genders. Folic acid levels and MTHFR T677 allele frequency did not show significant difference. Moderate hyperhomocysteinemia (Hcy >15μmol/L) or elevated Lp(a) (>300mg/L) increased the risk of CAD (OR 2.27, CI 1.36-3.80 and OR 1.64, CI 1.03-2.61, respectively) and MI (OR 2.52, CI 1.36-4.67 and OR 1.89, CI 1.06-3.38, respectively) only in women. Only simultaneous but not isolated elevation of Hcy and Lp(a) conferred a significant, 3.6-fold risk of CAD in females and even higher (11-fold) risk in young females, which suggested an interactive effect.

CONCLUSIONS

Moderate hyperhomocysteinemia or elevated Lp(a) level associated with a risk of CAD and MI only in women. While isolated elevation of one of the two parameters represented a mild risk of CAD, their combined elevation highly increased the risk in females. No such effect was observed in males.

[Study of the intronic polymorphism of the angiotensin 1 converting enzyme among coronary Tunisians]

BACKGROUND

The acute coronary syndromes (ACS) are classified among the major causes of mortality in the industrialized countries. The increased angiotensin I converting enzyme (ACEI) activity related to a genetic polymorphism constitutes a hereditary predisposition to these syndromes.

AIM

Evaluate the ACEI activity in Tunisian patients with coronary heart disease, and investigate the association between this activity and an intronic deletion of 287 pb on the intron 16 of the ACEI gene.

PATIENTS AND METHODS

Seventy-two coronary patients and 34 control subjects are recruited for our study. ACEI activity was measured by kinetic method. The intronic deletion was identified by PCR technique.

RESULTS

An increased activity of ACEI was observed in patients compared with control subjects (84.38 ± 33.83 UI/L vs 59.06 ± 18.2 UI/L, P=10(-5)). The molecular study showed a raised relative frequency of D/D genotype (51.4%) among patients, whereas among the witnesses, I/I genotype prevailed (62%). D/D genotype is always associated with highest ACEI activity for the patients and the control subjects.

CONCLUSION

The molecular studies and the biochemical investigations of the various parameters of cardiovascular risk (including the ACEI) direct towards a better treatment.

Stroke in young in India

Stroke in young has special significance in developing countries. This is so because some etiologies like cardioembolic infections are more common than in developed countries, and the affection of economically productive group adds further to the overall disease burden. The paper discusses the burden of stroke in young and its implications in a developing country like India along with an approach to identifying different causes that are known to occur in this age group.