Maximizing Polysaccharides and Phycoerythrin in Porphyridium purpureum via the Addition of Exogenous Compounds: A Response-Surface-Methodology Approach.

Phycoerythrin and polysaccharides have significant commercial value in medicine, cosmetics, and food industries due to their excellent bioactive functions. To maximize the production of biomass, phycoerythrin, and polysaccharides in Porphyridium purpureum, culture media were supplemented with calcium gluconate (CG), magnesium gluconate (MG) and polypeptides (BT), and their optimal amounts were determined using the response surface methodology (RSM) based on three single-factor experiments. The optimal concentrations of CG, MG, and BT were determined to be 4, 12, and 2 g L-1, respectively. The RSM-based models indicated that biomass and phycoerythrin production were significantly affected only by MG and BT, respectively. However, polysaccharide production was significantly affected by the interactions between CG and BT and those between MG and BT, with no significant effect from BT alone. Using the optimized culture conditions, the maximum biomass (5.97 g L-1), phycoerythrin (102.95 mg L-1), and polysaccharide (1.42 g L-1) concentrations met and even surpassed the model-predicted maximums. After optimization, biomass, phycoerythrin, and polysaccharides concentrations increased by 132.3%, 27.97%, and 136.67%, respectively, compared to the control. Overall, this study establishes a strong foundation for the highly efficient production of phycoerythrin and polysaccharides using P. purpureum.

Functional characterization of obscure puffer ToNK-lysin: A novel immunomodulator possessing anti-bacterial and anti-inflammatory properties.

NK-lysins are one of the most abundant antimicrobial peptides produced by cytotoxic T lymphocytes (CTLs) and natural killer cells (NKs), and identified as a new class of intrinsically disordered proteins, playing critical roles in the cell-mediated cytotoxicity response, as well as immunomodulatory and antimicrobial activities upon a significant range of pathogens. In the present study, an NK-lysin was identified from Obscure puffer Takifugu obscurus (ToNK-lysin). The open reading frame of ToNK-lysin sequence spans 423 bp, encoding a peptide with 140 amino acids which shares a moderate residue identity (18%-60%) with NK-lysin of mammals and other teleost species. Phylogenetic analysis revealed that ToNK-lysin was most closely related to NK-lysins from the Pleuronectiformes (Bastard halibut Paralichthys olivaceus and Pacific halibut Hippoglossus stenolepis). Comprehensive computational analysis revealed that ToNK-lysin have substantial level of intrinsic disorder, which might be contribute to its multifunction. The transcripts of the ToNK-lysin were detected in multiple examined tissues and most abundant in gills. After bacterial and Poly I:C challenge, the transcriptional levels of ToNK-lysin were significantly up-regulated in the head kidney, liver and spleen at different time points. The recombinant ToNK-lysin showed significant antibacterial activity against Vibrio harveyi and Escherichia coli, and the ToNK-lysin treatment not only reduced the bacterial loads in liver and head kidney, but also alleviated the pathogen-mediated upregulation of immune-related genes. In addition, the co-incubation with rToNK-lysin protein remarkably degraded bacterial genomic DNA, suggesting the potential mechanism of ToNK-lysin against microbes. These results suggest that ToNK-lysin possess antibacterial and immunoregulatory function both in vivo and in vitro, which may allow it a potential applicability to the aquaculture industry.

Changes in nitrosohemachrome lead to the discoloration of spiced beef during storage.

The discoloration of spiced beef during storage is a severe problem that limits the shelf life of products. This study explored the associations between discoloration and pH, water, lipid oxidation, and protein oxidation. Electron paramagnetic resonance and UV-Vis spectroscopy illustrated that the pigment of spiced beef was a pentacoordinate mononitrosylheme compound and its conjugated structure changed during storage. The low-field NMR and magnetic resonance imaging results showed that the mobility of water increased, and the water content decreased with the extension of storage time. Multivariate analysis showed that color attributes were negatively correlated with oxidation. The oxidation of nitrosohemachrome was the primary reason for the lightness (L*) and redness (a*) decline in spiced beef. In addition, water loss exerted a promotion function in the oxidation process. This study provides valuable information on maintaining the quality of spiced beef during storage.

Comparison of two kinds of peroxyl radical pretreatment at chicken myofibrillar proteins glycation on the formation of Nε-carboxymethyllysine and Nε-carboxyethyllysine.

During meat processing, two typical advanced glycation end products (AGEs), Nε-carboxymethyllysine (CML) and Nε-carboxyethyllysine (CEL), are generated by free radical induction. However, the impact of peroxyl radicals on myofibrillar proteins (MPs) glycosylation and CML and CEL formation is scarcely reported. In this study, two peroxyl radicals called ROO· and LOO· derived from AAPH (2,2'-azobis (2-methylpropionamidine) dihydrochloride) and linoleic acid were exposed prior to the Maillard reaction (glucosamine incubation at 37 °C for 24 h). Levels of AGEs (CML/CEL), protein oxidation (sulfhydryl/carbonyl), free amino group, surface hydrophobicity, zeta potential, particle size, intrinsic fluorescence intensity and secondary structure were determined. Together with Pearson's correlation, the assumption that free radicals promote MPs oxidation and glycation, alter the aggregation behavior and structure modification, leading to AGEs promotion has been built. In addition, the effect of dose-dependency of peroxyl radical on AGEs has also been established with different effects of peroxyl radical induction.

Association of sonographic features and clinicopathologic factors of papillary thyroid microcarcinoma for prevalence of lymph node metastasis: a retrospective analysis.

OBJECTIVE: The objective of the study was to develop an association between clinicopathologic and sonographic features of patients with papillary thyroid microcarcinoma and the prevalence of lymph node metastasis. METHODS: Clinicopathologic and sonographic features of 415 patients of papillary thyroid microcarcinoma with (n = 102) or without (n = 313) lymph node metastasis were retrospectively reviewed. The thickness of the lymph node ≥ 6 mm with intra-lymph nodal occupying lesions considered lymph node metastasis. Also, it was considered metastasis if lymph node perfusion or blood flow defect was found with any thickness size. Univariate following multivariate analysis was performed for the prediction of sonographic features and clinicopathologic factors for the prevalence of lymph node metastasis. RESULTS: Male gender (p = 0.041), age < 45 years (p = 0.042), preoperative calcitonin > 65 pg/ mL (p = 0.039), nodule size > 5 mm in diameter (p = 0.038), bilaterality (p = 0.038), tumor capsular invasion (p = 0.048), cystic change (p = 0.047), and hyper vascularity (p = 0.049) of thyroid nodules were associated with lymph node metastasis. Also, thyroid nodules 5 mm and more in diameter may have high aggressiveness. CONCLUSION: These data helped the surgeon for individualized treatment in thyroid carcinoma and avoid unnecessary prophylactic surgery of the lymph node.

Association of sonographic features and clinicopathologic factors of papillary thyroid microcarcinoma for prevalence of lymph node metastasis: a retrospective analysis

ABSTRACT Objective: The objective of the study was to develop an association between clinicopathologic and sonographic features of patients with papillary thyroid microcarcinoma and the prevalence of lymph node metastasis. Subjects and methods: Clinicopathologic and sonographic features of 415 patients of papillary thyroid microcarcinoma with (n = 102) or without (n = 313) lymph node metastasis were retrospectively reviewed. The thickness of the lymph node ≥ 6 mm with intra-lymph nodal occupying lesions considered lymph node metastasis. Also, it was considered metastasis if lymph node perfusion or blood flow defect was found with any thickness size. Univariate following multivariate analysis was performed for the prediction of sonographic features and clinicopathologic factors for the prevalence of lymph node metastasis. Results: Male gender ( p = 0.041), age < 45 years ( p = 0.042), preoperative calcitonin > 65 pg/ mL ( p = 0.039), nodule size > 5 mm in diameter ( p = 0.038), bilaterality ( p = 0.038), tumor capsular invasion ( p = 0.048), cystic change ( p = 0.047), and hyper vascularity ( p = 0.049) of thyroid nodules were associated with lymph node metastasis. Also, thyroid nodules 5 mm and more in diameter may have high aggressiveness. Conclusion: These data helped the surgeon for individualized treatment in thyroid carcinoma and avoid unnecessary prophylactic surgery of the lymph node.

Retraction Note: Ultrasound versus temporal artery biopsy in patients with Giant cell arteritis: a prospective cohort study.

An amendment to this paper has been published and can be accessed via the original article.

LncRNA-GAS5 regulates PDCD4 expression and mediates myocardial infarction-induced cardiomyocytes apoptosis via targeting MiR-21.

The present study was designed to investigate whether and how lncRNA-GAS5 regulates cardiomyocyte apoptosis in MI. MI rat model was established by the left anterior descending (LAD) coronary artery ligation. MI model was further evaluated by biomarkers detection and TUNEL, HE and Masson staining. The roles of lncRNA-GAS5 on hypoxia/reoxygenation (H/R)-induced cardiomyocytes survival, cell cycle arrest, and apoptosis were examined by MTT and flow cytometry in rat heart-derived H9c2 cells. Western blot was used to determine the effect of GAS5 on the expression of apoptosis-associated proteins and PI3 K/AKT signaling pathway. The direct bindings of GAS5 to miR-21 and miR-21 to PDCD4 were measured by dual-luciferase reporter assay or RNA immunoprecipitation. Decreased expressions of GAS5 and PDCD4 as well as increased miR-21 level were observed in the hearts of MI-modeled rat, accompanying with morphologically myocardial cell injury, as well as collagen deposition and fibrosis, and elevated levels of cTnl, CK, CK-MB and LDH. In the cell model, the knockdown of GAS5 promoted cell survival, prevented cell cycle arrest and inhibited cell apoptosis while the overexpression of GAS5 showed the opposite effects. GAS5 was found to downregulate miR-21 and the effects of GAS5 were attenuated by miR-21 mimics. GAS5 positively regulated PDCD4 expression by functioning as a sponge of miR-21 in H/R model. Moreover, GAS5 stimulated PDCD4 and suppressed PI3 K/AKT signal pathway. LncRNA-GAS5 regulates PDCD4 expression to mediate MI-induced cardiomyocyte apoptosis via targeting miR-21, suggesting that GAS5 could be a therapeutic target for MI.

Dynamic changes of the bacterial communities in roast chicken stored under normal and modified atmosphere packaging.

This study systematically investigated the dynamic changes in bacterial communities in roast chicken in normal and modified atmosphere packaging (MAP). The samples were stored under normal atmosphere and 40%/60% CO2 /N2 MAP conditions for 28 days at 4 °C. Changes in the number and type of microorganisms in roast chicken during storage were defined via cultural and 16S rDNA sequencing techniques. More Bacteroides, Chryseobacterium, Lactobacillus, and Acinetobacter than other bacteria were initially found in roast chicken. With normal packaging, Pseudomonas rapidly multiplied and became the main spoilage organism in roast chicken after 7 days, with a relative abundance of >90% of the entire bacterial flora. With MAP, due to the high salt content, Halomonas became the main spoilage organism in roast chicken by the middle of the storage period (14 days). Between days 21 and 28 of storage, Pseudomonas gradually became the main spoilage organism in roast chicken, but its relative abundance was much lower in MAP than in normal packaging, followed by Lachnospiraceae (NK4A136 group) and Altererythrobacter. Our research shows that the microbes in roast chicken mainly originated from the processing environment and operators. The combination of MAP with a low storage temperature could effectively improve the quality and safety of roast chicken meat. PRACTICAL APPLICATIONS: This research showed the dynamic changes in the bacterial community of roast chicken stored under normal and modified atmosphere packaging (MAP). Microorganisms in roast chicken are mainly obtained from the processing environment and operators. Combining MAP with storage at low temperatures can effectively improve the quality and safety of roast chicken.

Purification and identification of antioxidant peptides from duck plasma proteins.

The antioxidant peptides extracted from duck plasma hydrolysate (DPH) was investigated. The antioxidant activity of DPH, which was isolated and purified via ultrafiltration, size exclusion chromatography, and reversed-phase high-performance liquid chromatography, was evaluated using its free radical scavenging ability. Nano-liquid chromatography-tandem mass spectrometry was conducted to identify the DPH fractions with the highest antioxidant ability. Seven novel peptides: LDGP, TGVGTK, EVGK, RCLQ, LHDVK, KLGA, and AGGVPAG (400.43, 561.63, 431.48, 260.14, 610.71, 387.47, and 527.57 Da, respectively) were identified and synthesized using a solid-phase peptide produce to evaluate their antioxidant activities. Of these, EVGK exhibited the highest Fe2+ chelating ability (16.35%), and RCLQ presented the highest reducing power, 2,2-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt scavenging activity, and 1,1-diphenyl-2-picrylhydrazyl scavenging rate (0.62, 274.83 mM TE/mg, and 95.12%, respectively). Our results indicated that DPH possessed antioxidant capabilities and could be used to obtain antioxidant peptides, thus adding economic value to duck blood.

Effects of Cooking Methods and Tea Marinades on the Formation of Heterocyclic Amines and Benzo[a]pyrene in Grilled Drumsticks.

ABSTRACT: The effects of different grilling methods and tea marinades on the formation of heterocyclic amines (HCAs) and benzo[a]pyrene (BaP) in grilled chicken drumsticks were investigated. This study showed that both the grilling method and type of charcoal used in charcoal grilling had a significant effect on the formation of HCAs and BaP. The total content of HCAs and BaP detected in drumsticks was the lowest under electric roasting, at 7.25 and 0.04 ng/g, respectively; thus, the electric grill can be used as an alternative grilling method to meet consumer demands for safety. The free radical scavenging ability of tea infusion was significantly higher than that of spice infusion. The white tea marinade significantly increased radical scavenging activity and prevented formation of HCAs and BaP more than the green tea marinade; thus, tea marinade can be applied to flavoring as a pretreatment to preserve the quality of meat and to decrease the generation of HCAs and BaP during cooking.

Heterocyclic amines in braised chicken may mainly infiltrate from reused marinade during braising, instead of thermic generation.

BACKGROUND: Sauce braised meat products are popular in Asia, although their complicated processing may lead to potential safety risks. Especially, how hazardous compounds are formed during their preparation is still unclear. In the present study, braised chicken breasts, which are a typical Chinese sauce braised meat product, were used to investigate the formation of heterocyclic amines (HCAs) during heat treatment. RESULTS: Precursor content (creatine and reducing sugar), HCA level and temperature were measured in different parts of the chicken breast at each processing stage. The results obtained showed that the increasing trends of total HCA content in different parts of chicken breast were not the same. Only total HCA content in the skin (4.93 ± 0.80 ng g-1 ) increased significantly after deep-frying. During braising, total HCA level in the skin was high (12.1-14.3 ng g-1 ) and relatively stable. However, total HCA content in pectoralis major muscle (3.90-7.40 ng g-1 ) and pectoralis minor muscle (1.44-5.31 ng g-1 ) was much lower than in the skin, and increased steadily with braising time. CONCLUSION: Braising is the main factor which affects HCA level in braised chicken. Combining the results of temperature and precursor content, a possible explanation for the large amount of HCAs in braised chicken is the gradual infiltration from reused marinade, instead of thermic generation. © 2019 Society of Chemical Industry.

Formation of Nϵ-Carboxymethyllysine and Nϵ-Carboxyethyllysine in Prepared Chicken Breast by Pan Frying.

The objective of this work was to investigate the effects of pan frying on the formation of two typical advanced glycation end products (AGEs) named Nϵ-carboxymethyllysine (CML) and Nϵ-carboxyethyllysine (CEL) in prepared chicken breast. The marinated chicken breast was pan fried for 1 to 6 min, and then protein, fat, moisture, carbonyl, sulfhydryl, thiobarbituric acid reactive substances, chroma (a*, b*, L*), absorbance at 294 and 420 nm, and AGE (CEL) levels were measured once a minute. Pearson's correlation was determined and indicated that moisture was significantly negatively correlated with Maillard reaction and AGEs (P < 0.05), fat and protein contents were significantly positively correlated with AGEs (P < 0.05), and a* values were positively correlated with Maillard reaction and CEL (P < 0.05). Protein and lipid oxidation played an important role on the correlation of AGEs. In conclusion, Maillard reaction and oxidation reaction are two important factors affecting AGE formation.

Ultrasound versus temporal artery biopsy in patients with Giant cell arteritis: a prospective cohort study.

BACKGROUND: Diagnosis of giant cell arteritis by temporal artery biopsy is time-consuming and visual loss lies in the first week after its diagnosis. The purpose of the study was to test the hypothesis that ultrasound can reduce the risk of overdiagnosis and overtreatment in giant cell arteritis. METHODS: Data regarding physical/ clinical features examinations, temporal artery biopsy examinations, ultrasound findings, and magnetic resonance imaging examinations of 980 suspected patients for giant cell arteritis were included in the study. Decision curve analysis was applied to get a beneficial score for selected diagnostic modalities. Cost analysis was performed for each patient. RESULTS: Fewer numbers of false positive giant cell arteritis results were reported under physical/ clinical features examinations following ultrasound detection than physical/clinical features examinations following temporal artery biopsy examinations (45 vs. 127, p < 0.0001). The working area that detects giant cell arteritis at least one time for physical/ clinical features examinations following ultrasound detection and physical/ clinical features examinations following temporal artery biopsy examinations were 0-91% and 0-86%. No significant difference for true negative results between magnetic resonance imaging and physical and clinical features examinations following ultrasound detection (p = 0.007). Physical and clinical features examinations following ultrasound detection were less expensive method than physical/ clinical features examinations following temporal artery biopsy examinations (14,023 ± 982 ¥/patient vs. 18,551 ± 1231 ¥/patient, p < 0.0001) and MRI. CONCLUSION: Physical and clinical features examinations following ultrasound are recommended for diagnosis of patients with suspected giant cell arteritis.

Content, causes and analysis of heterocyclic amines in Chinese traditional braised chicken.

Braised chicken is a popular traditional chicken product in China with a special and complicated culinary method. However, there has been little research focused on the food safety problems caused by hazardous compounds in braised chicken. In this study, the contents of heterocyclic amines (HCAs) in representative braised chicken samples were determined. Total HCAs in braised chicken were relatively high (6.20-27.7 ng g-1), and aminoimidazoazaarenes (AIAs) took a large proportion (54.0-86.4%). 2-Amino-3-methylimidazo[4,5-f]quinoline (IQ) was found in all samples with a high level (2.72-13.5 ng g-1), whilst 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was low (0.14-0.41 ng g-1). 9H-pyrido[3,4-b]indole (Norharman) and 1-methyl-9H-pyrido[3,4-b]indole (Harman) were main components in aminocarbolines (ACs). So the potential safety risk in braised chicken caused by high HCAs content should be paid attention. Principal component analysis (PCA) was used to analyse and visualise the differences of HCAs levels among braised chicken samples. The result indicated that the differences among these samples were significant, but there were no obvious similarities between samples produced in the same regions. Moreover, there were rare significant positive correlations between chemical components (including moisture, fat, protein, creatine and free amino acids) and hazardous compounds. Considering PCA and correlation analysis results, these parameters may play a major role in the HCAs levels in Chinese traditional braised chicken.

Polymorphism of CONNEXIN37 gene is a risk factor for ischemic stroke in Han Chinese population.

BACKGROUND: Stroke has a high fatality and disability rate, and is one of the main burdens to human health. It is thus very important to identify biomarkers for the development of effective approaches for the prevention and treatment of stroke. Connexin37 is an anti-inflammatory cytokine and is involved in chronic inflammation and atherosclerosis. Recent studies have found that CONNEXIN37 gene variations are associated with atherosclerosis diseases, such as coronary heart disease and stroke, but its association with stroke in distinct human populations remains to be determined. We report here the analysis of the association of the single nucleotide polymorphisms (SNPs) of CONNEXIN37 with ischemic stroke in Han Chinese population. METHODS: Two SNPs of CONNEXIN37 gene were analyzed in 385 ischemic stroke patients and 362 hypertension control patients using ligase detection reaction (LDR) method. RESULTS: Logistic regression analysis demonstrated that, AG and GG genotypes of SNP rs1764390 and CC genotype of rs1764391 of CONNEXIN37 were associated with an increased risk of ischemic stroke, and that G allele of rs1764390 is a risk factor for ischemic stroke. Further, we found that SNP rs1764390 and SNP rs1764391 in CONNEXIN37 were associated with ischemic stroke under additive/dominant model, and recessive/dominant model, respectively. CONCLUSION: Our results indicate that CONNEXIN37 gene polymorphism is an ischemic stroke risk factor in Northern Han Chinese.

Targeting the middle region of CP4-EPSPS protein for its traceability in highly processed soy-related products.

Transgenic components in genetically modified organisms consist not only of the transgenic genes, but also the transgenic protein. However, compared with transgenic DNA, less attention has been paid to the detection of expressed protein, especially those degraded from genetically modified soybean after food processing. In this study, the full length 5-enolpyruvyl-shikimate-3-phosphate synthase (CP4-EPSPS, 47.6 kD) protein was probed with the SC-16 (S19-R33) and the DC-16 (D219-K233) polyclonal antibodies in immunoblots. Both antibodies were able to detect the full length CP4-EPSPS and its residues in soy powder made from Roundup-Ready soybeans after heating and microwaving treatments which also reduced the molecular weight of the protein to 45.8 and 38.7 kD, respectively. Taken together the immunoblot results suggest that the middle region of the CP4-EPSPS protein possessed better stability than its N-terminal during thermal processing. This deduction was further validated by autoclave treatment, where a 37.4 kD residue of the protein was recognized by DC-16. A similar result was obtained in processed smoked sausage containing Roundup Ready soybean protein isolate (as an extender). The additional use of a further polyclonal antibody CK-17 (C372-K388), showed that compared with only the one signal for CP4-EPSPS detected by the SC-16 and CK-17 antibodies, the DC-16 middle region antibody detected four signals for CP4-EPSPS from five market sourced soy protein concentrates. Taken together, the study suggested that the middle region of CP4-EPSPS was more useful than the N- and C-terminal for tracing transgenic CP4-EPSPS protein and its remnants in highly processed soy-related products.

Genetic Variant of Kalirin Gene Is Associated with Ischemic Stroke in a Chinese Han Population.

INTRODUCTION: Ischemic stroke is a complex disorder resulting from the interplay of genetic and environmental factors. Previous studies showed that kalirin gene variations were associated with cardiovascular disease. However, the association between this gene and ischemic stroke was unknown. We performed this study to confirm if kalirin gene variation was associated with ischemic stroke. METHODS: We enrolled 385 ischemic stroke patients and 362 controls from China. Three SNPs of kalirin gene were genotyped by means of ligase detection reaction-PCR method. Data was processed with SPSS and SHEsis platform. RESULTS: SNP rs7620580 (dominant model: OR = 1.590, p = 0.002 and adjusted OR = 1.662, p = 0.014; additive model: OR = 1.490, p = 0.002 and adjusted OR = 1.636, p = 0.005; recessive model: OR = 2.686, p = 0.039) and SNP rs1708303 (dominant model: OR = 1.523, p = 0.007 and adjusted OR = 1.604, p = 0.028; additive model: OR = 1.438, p = 0.01 and adjusted OR = 1.476, p = 0.039) were associated with ischemic stroke. The GG genotype and G allele of SNP rs7620580 were associated with a risk for ischemic stroke with an adjusted OR of 3.195 and an OR of 1.446, respectively. Haplotype analysis revealed that A-T-G,G-T-A, and A-T-A haplotypes were associated with ischemic stroke. CONCLUSIONS: Our results provide evidence that kalirin gene variations were associated with ischemic stroke in the Chinese Han population.

ARHGEF10 gene polymorphism is closely associated with the risk of ischemic stroke in Northern Han Chinese population.

Stroke is a common disease with high mortality and morbidity. It is of high importance to identify biomarkers of stroke. Rho guanine nucleotide-exchange factor(GEF) 10 (ARHGEF10) gene polymorphism has been found to be associated with various human diseases, but its correlation with stroke remains unknown. This study aims to evaluate the potential association of the single nucleotide polymorphisms (SNPs) of ARHGEF10 with ischemic stroke (IS) in northern Han Chinese population. Three SNPs of ARHGEF10 gene were analyzed in 385 IS patients and 362 hypertension control patients using the ligase detection reaction (LDR) method. Logistic regression analysis demonstrated that GG genotypes of SNP rs2280887 were associated with an increased risk of IS in dominant, recessive, and additive models. Moreover, SNP rs9657362 and SNP rs4480162 were significantly associated with IS in dominant and additive models. These results indicate that ARHGEF10 gene polymorphisms may affect IS risk in northern Han Chinese.

Single-Nucleotide Polymorphism rs17611 of Complement Component 5 Shows Association with Ischemic Stroke in Northeast Chinese Population.

BACKGROUND: Complement component 5 (C5) has been described to play an important role in the development and progression of atherosclerosis and cardiovascular disease. Our aim was to determine whether genetic variation of C5 was associated with ischemic stroke (IS) in northeast Chinese population. METHODS: We used a case-control study involving 386 IS patients and 386 non-IS controls from a rural population and determined the genotypes of five polymorphisms (rs12237774, rs17611, rs4837805, rs7026551, and rs1017119) of C5 gene by Snapshot single-nucleotide polymorphism genotyping assays to assess any links with IS. RESULTS: In univariate analysis, rs17611 was significantly associated with IS in the additive model, the dominant model, and recessive model (additive p 0.031, dominant p 0.034, and recessive p 0.027). After adjustment for Binary Logistic Regression, rs17611 polymorphism was still significant in three models (adjusted odds ratio (OR) = 1.306, 95% confidence interval (CI) = 1.069-1.595, p-value = 0.009 in an additive model; OR = 1.378, 95% CI = 1.024-1.856, p-value = 0.035 in a dominant model; and OR = 1.511, 95% CI = 1.048-2.18, p-value = 0.027 in a recessive model). CONCLUSION: In this sample of patients, genetic variation of rs17611 in C5 is associated with higher prevalence of IS.