1. Association between index finger and ring finger length ratios and polymorphism of homeobox A11 gene locus among Ningxia college students
Meng-Yi YANG ; Shi-Bo NIU ; Jing ZHANG ; Jie DANG ; Zhan-Bing MA ; Hong LU ; Zheng-Hao HUO
Acta Anatomica Sinica 2024;55(1):62-66
Objective To investigate the association between the index finger and ring finger length ratio (2D ∶ 4D) and of four loci (rs6461992‚ rs6968828‚ rs7801581‚ rs17427875) polymorphism of homeobox (HOX) A11 gene among Ningxia college students. Methods Digit camera was used to collect frontal hand photos of 667 Han college students (348 males and 319 females) from Ningxia province; Image analysis software was used to mark the anatomical points and measure finger lengths of the index and ring fingers of both hands; multiplex PCR was used to detect each locus polymorphisms of HOXA11 gene; statistical software was used to compare and analyze the differences and associations of 2D ∶4D and gene polymorphisms between different genders. Results Among Ningxia Han college students‚ both left hand and right hand 2D ∶ 4D were significantly higher in females than those of in males (all P< 0. 05)‚ and there were no significant sex differences in right-left hand 2D ∶4D; the genotypes and allele frequencies of rs7801581 locus of HOXA11 gene differed significantly between genders (all P < 0. 05)‚ and none of the other locus polymorphisms showed any significant sex differences; only female left hand 2D ∶4D was significantly associated with rs6461992 locus genotype in the relationship between 2D ∶4D and HOXA11 polymorphisms (P<0. 05). Conclusion There were significant sex differences in 2D ∶ 4D among Han college students in Ningxia‚ and the rs6461992 locus polymorphism of HOXA11 gene may be associated with the formation of 2D ∶4D in females.
2.Association between index-ring finger length ratio and polymorphisms of 6 phalange-bone development related genes
Meng-Yi YANG ; Shi-Bo NIU ; Jing ZHANG ; Liang PENG ; Jie DANG ; Zhan-Bing MA ; Hong LU ; Zheng-Hao HUO
Acta Anatomica Sinica 2024;55(2):181-187
Objective To investigate the association of 13 single nucleotide polymorphism(SNP)sites in 6 phalange-bone development related genes[fibroblast growth factor receptor 2(FGFR2),indian hedgehog signaling molecule(IHH),Msh homeobox 1(MSX1),Runx family transcription factor 2(RUNX2),SRY-box transcription factor 9(SOX9),Wnt family member 5A(WNT5A)]with human index-ring finger length ratio(2D∶4D).Methods Digital cameras were used to take frontal photographs of the hands of 731 college students(358 males and 373 females)in Ningxia,and image analysis software was used to mark anatomical points and measure finger lengths of index(2th)and ring(4th);genotyping of 13 SNP sites(rs1047057,rs755793,rs41258305,rs3731881,rs3100776,rs12532,rs3821949,rs45585135,rs3749863,rs1042667,rs12601701,rs1829556,rs3732750)for 6 genes by multiplex PCR;One-Way ANOVA or independent sample t-test indirectly assessed the association between 2D∶4D and 13 SNP sites.Results Both left and right hand 2D∶4D were significantly higher in females than males in Ningxia college students(all P<0.01);no statistically significant differences in genotype and allele frequencies of the 13 SNP sites among different sexes(all P>0.05);among different sexes,male left hand 2D∶4D was significantly associated with the genotype of SOX9 gene rs12601701 site(P<0.05)and right hand 2D∶4D was significantly associated with the genotype of WNT5A gene rs1829556 site(P<0.05);the female right hand 2D∶4D was significantly associated with the MSX1 gene rs12532(P<0.01)and rs3821949(P<0.05)sites genotypes.Conclusion SOX9(rs12601701),WNT5A(rs1829556)and MSX1(rs12532 and rs3821949)gene polymorphisms may be associated with the formation of 2D∶4D in Ningxia population.
3.Incidence of postoperative complications in Chinese patients with gastric or colorectal cancer based on a national, multicenter, prospective, cohort study
Shuqin ZHANG ; Zhouqiao WU ; Bowen HUO ; Huining XU ; Kang ZHAO ; Changqing JING ; Fenglin LIU ; Jiang YU ; Zhengrong LI ; Jian ZHANG ; Lu ZANG ; Hankun HAO ; Chaohui ZHENG ; Yong LI ; Lin FAN ; Hua HUANG ; Pin LIANG ; Bin WU ; Jiaming ZHU ; Zhaojian NIU ; Linghua ZHU ; Wu SONG ; Jun YOU ; Su YAN ; Ziyu LI
Chinese Journal of Gastrointestinal Surgery 2024;27(3):247-260
Objective:To investigate the incidence of postoperative complications in Chinese patients with gastric or colorectal cancer, and to evaluate the risk factors for postoperative complications.Methods:This was a national, multicenter, prospective, registry-based, cohort study of data obtained from the database of the Prevalence of Abdominal Complications After Gastro- enterological Surgery (PACAGE) study sponsored by the China Gastrointestinal Cancer Surgical Union. The PACAGE database prospectively collected general demographic characteristics, protocols for perioperative treatment, and variables associated with postoperative complications in patients treated for gastric or colorectal cancer in 20 medical centers from December 2018 to December 2020. The patients were grouped according to the presence or absence of postoperative complications. Postoperative complications were categorized and graded in accordance with the expert consensus on postoperative complications in gastrointestinal oncology surgery and Clavien-Dindo grading criteria. The incidence of postoperative complications of different grades are presented as bar charts. Independent risk factors for occurrence of postoperative complications were identified by multifactorial unconditional logistic regression.Results:The study cohort comprised 3926 patients with gastric or colorectal cancer, 657 (16.7%) of whom had a total of 876 postoperative complications. Serious complications (Grade III and above) occurred in 4.0% of patients (156/3926). The rate of Grade V complications was 0.2% (7/3926). The cohort included 2271 patients with gastric cancer with a postoperative complication rate of 18.1% (412/2271) and serious complication rate of 4.7% (106/2271); and 1655 with colorectal cancer, with a postoperative complication rate of 14.8% (245/1655) and serious complication rate of 3.0% (50/1655). The incidences of anastomotic leakage in patients with gastric and colorectal cancer were 3.3% (74/2271) and 3.4% (56/1655), respectively. Abdominal infection was the most frequently occurring complication, accounting for 28.7% (164/572) and 39.5% (120/304) of postoperative complications in patients with gastric and colorectal cancer, respectively. The most frequently occurring grade of postoperative complication was Grade II, accounting for 65.4% (374/572) and 56.6% (172/304) of complications in patients with gastric and colorectal cancers, respectively. Multifactorial analysis identified (1) the following independent risk factors for postoperative complications in patients in the gastric cancer group: preoperative comorbidities (OR=2.54, 95%CI: 1.51-4.28, P<0.001), neoadjuvant therapy (OR=1.42, 95%CI:1.06-1.89, P=0.020), high American Society of Anesthesiologists (ASA) scores (ASA score 2 points:OR=1.60, 95% CI: 1.23-2.07, P<0.001, ASA score ≥3 points:OR=0.43, 95% CI: 0.25-0.73, P=0.002), operative time >180 minutes (OR=1.81, 95% CI: 1.42-2.31, P<0.001), intraoperative bleeding >50 mL (OR=1.29,95%CI: 1.01-1.63, P=0.038), and distal gastrectomy compared with total gastrectomy (OR=0.65,95%CI: 0.51-0.83, P<0.001); and (2) the following independent risk factors for postoperative complications in patients in the colorectal cancer group: female (OR=0.60, 95%CI: 0.44-0.80, P<0.001), preoperative comorbidities (OR=2.73, 95%CI: 1.25-5.99, P=0.030), neoadjuvant therapy (OR=1.83, 95%CI:1.23-2.72, P=0.008), laparoscopic surgery (OR=0.47, 95%CI: 0.30-0.72, P=0.022), and abdominoperineal resection compared with low anterior resection (OR=2.74, 95%CI: 1.71-4.41, P<0.001). Conclusion:Postoperative complications associated with various types of infection were the most frequent complications in patients with gastric or colorectal cancer. Although the risk factors for postoperative complications differed between patients with gastric cancer and those with colorectal cancer, the presence of preoperative comorbidities, administration of neoadjuvant therapy, and extent of surgical resection, were the commonest factors associated with postoperative complications in patients of both categories.
4.Incidence of postoperative complications in Chinese patients with gastric or colorectal cancer based on a national, multicenter, prospective, cohort study
Shuqin ZHANG ; Zhouqiao WU ; Bowen HUO ; Huining XU ; Kang ZHAO ; Changqing JING ; Fenglin LIU ; Jiang YU ; Zhengrong LI ; Jian ZHANG ; Lu ZANG ; Hankun HAO ; Chaohui ZHENG ; Yong LI ; Lin FAN ; Hua HUANG ; Pin LIANG ; Bin WU ; Jiaming ZHU ; Zhaojian NIU ; Linghua ZHU ; Wu SONG ; Jun YOU ; Su YAN ; Ziyu LI
Chinese Journal of Gastrointestinal Surgery 2024;27(3):247-260
Objective:To investigate the incidence of postoperative complications in Chinese patients with gastric or colorectal cancer, and to evaluate the risk factors for postoperative complications.Methods:This was a national, multicenter, prospective, registry-based, cohort study of data obtained from the database of the Prevalence of Abdominal Complications After Gastro- enterological Surgery (PACAGE) study sponsored by the China Gastrointestinal Cancer Surgical Union. The PACAGE database prospectively collected general demographic characteristics, protocols for perioperative treatment, and variables associated with postoperative complications in patients treated for gastric or colorectal cancer in 20 medical centers from December 2018 to December 2020. The patients were grouped according to the presence or absence of postoperative complications. Postoperative complications were categorized and graded in accordance with the expert consensus on postoperative complications in gastrointestinal oncology surgery and Clavien-Dindo grading criteria. The incidence of postoperative complications of different grades are presented as bar charts. Independent risk factors for occurrence of postoperative complications were identified by multifactorial unconditional logistic regression.Results:The study cohort comprised 3926 patients with gastric or colorectal cancer, 657 (16.7%) of whom had a total of 876 postoperative complications. Serious complications (Grade III and above) occurred in 4.0% of patients (156/3926). The rate of Grade V complications was 0.2% (7/3926). The cohort included 2271 patients with gastric cancer with a postoperative complication rate of 18.1% (412/2271) and serious complication rate of 4.7% (106/2271); and 1655 with colorectal cancer, with a postoperative complication rate of 14.8% (245/1655) and serious complication rate of 3.0% (50/1655). The incidences of anastomotic leakage in patients with gastric and colorectal cancer were 3.3% (74/2271) and 3.4% (56/1655), respectively. Abdominal infection was the most frequently occurring complication, accounting for 28.7% (164/572) and 39.5% (120/304) of postoperative complications in patients with gastric and colorectal cancer, respectively. The most frequently occurring grade of postoperative complication was Grade II, accounting for 65.4% (374/572) and 56.6% (172/304) of complications in patients with gastric and colorectal cancers, respectively. Multifactorial analysis identified (1) the following independent risk factors for postoperative complications in patients in the gastric cancer group: preoperative comorbidities (OR=2.54, 95%CI: 1.51-4.28, P<0.001), neoadjuvant therapy (OR=1.42, 95%CI:1.06-1.89, P=0.020), high American Society of Anesthesiologists (ASA) scores (ASA score 2 points:OR=1.60, 95% CI: 1.23-2.07, P<0.001, ASA score ≥3 points:OR=0.43, 95% CI: 0.25-0.73, P=0.002), operative time >180 minutes (OR=1.81, 95% CI: 1.42-2.31, P<0.001), intraoperative bleeding >50 mL (OR=1.29,95%CI: 1.01-1.63, P=0.038), and distal gastrectomy compared with total gastrectomy (OR=0.65,95%CI: 0.51-0.83, P<0.001); and (2) the following independent risk factors for postoperative complications in patients in the colorectal cancer group: female (OR=0.60, 95%CI: 0.44-0.80, P<0.001), preoperative comorbidities (OR=2.73, 95%CI: 1.25-5.99, P=0.030), neoadjuvant therapy (OR=1.83, 95%CI:1.23-2.72, P=0.008), laparoscopic surgery (OR=0.47, 95%CI: 0.30-0.72, P=0.022), and abdominoperineal resection compared with low anterior resection (OR=2.74, 95%CI: 1.71-4.41, P<0.001). Conclusion:Postoperative complications associated with various types of infection were the most frequent complications in patients with gastric or colorectal cancer. Although the risk factors for postoperative complications differed between patients with gastric cancer and those with colorectal cancer, the presence of preoperative comorbidities, administration of neoadjuvant therapy, and extent of surgical resection, were the commonest factors associated with postoperative complications in patients of both categories.
5.Analysis of success rate of organoid construction of nasopharyngeal carcinoma by first-day suspension method.
Hui Min HUO ; Xi YAO ; Yong Jing LAI ; Wei LU ; Chun Lei LIU ; Zhong Heng HUANG ; Zheng Bo WEI ; Ying XIE
Chinese Journal of Otorhinolaryngology Head and Neck Surgery 2023;58(3):250-255
Objective: To investigate the efficacy of the first-day suspension method for improving the success rate of construction of nasopharyngeal carcinoma-patient derived organoids (NPC-PDO). Methods: The tumor samples of 14 nasopharyngeal carcinoma(NPC) patients, i.e.,13 males and 1 female, with a mean age of 43.0±12.0 years old, were collected from the Affiliated Tumor Hospital of Guangxi Medical University and the First Affiliated Hospital of Guangxi Medical University from January 2022 to July 2022. The tumor samples of 3 patients were digested into single cell suspension and divided into 2 groups, for comparing the efficacy of NPC-PDO construction by the direct inoculation method and the first-day suspension method. The remaining 11 patients were randomized to receive either the direct inoculation method or the first-day suspension method for NPC-PDO construction. The diameter and the number of spheres of NPC-PDO constructed by the two methods were compared by optical microscope; the 3D cell viability detection kit was used to compare the cell viability; the survival rates were compared by trypan blue staining; the success rates of the two construction methods were compared; the number of cases which could be successfully passaged for more than 5 generations and were consistent with the original tissue by pathological examination was counted; and the dynamic changes of cells in suspension overnight were observed by live cell workstation. The independent sample t-test was applied to compare the measurement data of the two groups, and the chi-square test was used to compare the classification data. Results: Compared with the direct inoculation, the diameter and the number of spheres of NPC-PDO constructed by the first-day suspension method were increased, with a higher cell activity, and the success rate of construction was obviously improved (80.0% vs 16.7%, χ2=4.41, P<0.05). In the suspension state, some of the cells aggregated and increased their ability to proliferate. Conclusion: The first-day suspension method can improve the success rate of NPC-PDO construction, especially for those whose original tumor sample size is small.
Male
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Humans
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Female
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Adult
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Middle Aged
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Nasopharyngeal Carcinoma
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China
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Microscopy
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Organoids
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Nasopharyngeal Neoplasms
6. Digit ratio in men with schizophrenia
Shi-Bo NIU ; Meng-Yi YANG ; Yu XU ; Jie DANG ; Zhan-Bing MA ; Zheng-Hao HUO ; Hong LU ; Shi-Bo NIU ; Meng-Yi YANG ; Yu XU ; Jie DANG ; Zhan-Bing MA ; Zheng-Hao HUO ; Hong LU
Acta Anatomica Sinica 2023;54(4):473-476
Objective To investigate the relationship between digit ratio and schizophrenia in men from Ningxia Han nationality. Methods Using anthropometry, digital camera was used to obtain finger photographs of both hands of 216 male subjects (nonnal control; 116, schizophrenia patient; 100). The anatomical points were marked and the length of each finger of both hands were measured by computer image analysis software (Image-Pro Plus 6 . 0 ) . Differences of the mean digit ratio of left and right hand 2D:3D, 2D:4D, 2D:5D, 3D:4D, 3D:5D, 4D:5D between the control group and the patient group were compared. The correlation between 2D :4D and onset age in the patient group were analyzed. Results Except for left and right hand 3D :4D, digit ratios in patient group were significantly higher than those in control group (2D :4D and 3D :5D in both hands, right hand 3D :5D, p all<0. 001; 2D :3D and 4D :5D, left hand 3D :5D, P<0. 0 1 ) . Compared with the control group (left hand; 1%, right hand; 1%) , the percentage of 2D:4D Ss 1 were significantly higher ( P<0. 05) in the patient group (left hand; 6% , right hand; 7%). There were no conelations between 2D :4D mean value and onset age in patients group (P>0. 05). Conclusion Digit ratio is related to the occurrence of schizophrenia in Ningxia Han male.
7. Association between hydroxysteroid dehydrogenases gene family single-nucleotide polymorphisms and digit ratio
Fan LI ; Zhan-Bing MA ; Jing ZHANG ; Meng-Yi YANG ; Yuan WANG ; Qian MA ; Hong LU ; Zheng-Hao HUO ; Jie DANG ; Fan LI ; Zhan-Bing MA ; Jing ZHANG ; Meng-Yi YANG ; Yuan WANG ; Qian MA ; Hong LU ; Zheng-Hao HUO ; Jie DANG
Acta Anatomica Sinica 2023;54(2):208-215
Objective To investigate the association between 8 single-nucleotide polymorphisms (SNPs) of hydroxysteroid dehydrogenase (HSD) gene family and human digit ratio (2D ∶ 4D). Methods Randomly selected 808 college students (400 males and 408 females) as subjects, the digit ratio of left and right fingers were measured and calculated using computer image software. Eight SNPs (rs1000283, rs2236903, rs5479, rs56303414, rs676387, rs4445895, rs2066474, rs8190478) in HSD11B and HSD17B gene families were genotyped by multiplex PCR. The association between 2D ∶4D and different genotypes was analyzed by One-Way ANOVA. Results Female left hand(L)2D ∶ 3D, L2D ∶4D, L3D ∶4D, right hand(R)2D ∶4D, R2D ∶5D were significantly higher than male (P<0. 05). The genotype frequency of rs2236903 (HSD11B1) was significantly different between male and female (P < 0. 05). A good linkage disequilibrium was found between rs1000283and rs2236903 of HSD11B1 gene, rs5479 and rs56303414 of HSD11B2 gene, but there was no statistical difference in frequency between male and female students(P>0. 05). The genotypes frequency of the 8 SNPs were not significantly associated with digit ratio (2D ∶4D) in both males and females (P>0. 05). Conclusion There are significant gender differences in digit ratio in Ningxia Han college students, but there is no correlation between digit ratio and 8 SNPs in HSD11B and HSD17B gene families, suggesting that HSD11B and HSD17B gene families may have nothing to do with the formation of human digit ratio.
8.Inverted U-Shaped Associations between Glycemic Indices and Serum Uric Acid Levels in the General Chinese Population: Findings from the China Cardiometabolic Disease and Cancer Cohort (4C) Study.
Yuan Yue ZHU ; Rui Zhi ZHENG ; Gui Xia WANG ; Li CHEN ; Li Xin SHI ; Qing SU ; Min XU ; Yu XU ; Yu Hong CHEN ; Xue Feng YU ; Li YAN ; Tian Ge WANG ; Zhi Yun ZHAO ; Gui Jun QIN ; Qin WAN ; Gang CHEN ; Zheng Nan GAO ; Fei Xia SHEN ; Zuo Jie LUO ; Ying Fen QIN ; Ya Nan HUO ; Qiang LI ; Zhen YE ; Yin Fei ZHANG ; Chao LIU ; You Min WANG ; Sheng Li WU ; Tao YANG ; Hua Cong DENG ; Jia Jun ZHAO ; Lu Lu CHEN ; Yi Ming MU ; Xu Lei TANG ; Ru Ying HU ; Wei Qing WANG ; Guang NING ; Mian LI ; Jie Li LU ; Yu Fang BI
Biomedical and Environmental Sciences 2021;34(1):9-18
Objective:
The relationship between serum uric acid (SUA) levels and glycemic indices, including plasma glucose (FPG), 2-hour postload glucose (2h-PG), and glycated hemoglobin (HbA1c), remains inconclusive. We aimed to explore the associations between glycemic indices and SUA levels in the general Chinese population.
Methods:
The current study was a cross-sectional analysis using the first follow-up survey data from The China Cardiometabolic Disease and Cancer Cohort Study. A total of 105,922 community-dwelling adults aged ≥ 40 years underwent the oral glucose tolerance test and uric acid assessment. The nonlinear relationships between glycemic indices and SUA levels were explored using generalized additive models.
Results:
A total of 30,941 men and 62,361 women were eligible for the current analysis. Generalized additive models verified the inverted U-shaped association between glycemic indices and SUA levels, but with different inflection points in men and women. The thresholds for FPG, 2h-PG, and HbA1c for men and women were 6.5/8.0 mmol/L, 11.0/14.0 mmol/L, and 6.1/6.5, respectively (SUA levels increased with increasing glycemic indices before the inflection points and then eventually decreased with further increases in the glycemic indices).
Conclusion
An inverted U-shaped association was observed between major glycemic indices and uric acid levels in both sexes, while the inflection points were reached earlier in men than in women.
Aged
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Asian Continental Ancestry Group
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Blood Glucose/analysis*
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China/epidemiology*
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Cohort Studies
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Diabetes Mellitus/blood*
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Female
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Glucose Tolerance Test
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Glycated Hemoglobin A/analysis*
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Glycemic Index
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Humans
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Male
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Middle Aged
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Uric Acid/blood*
9.Study of the mechanism underlying the effect of SOCS3 rs4969170 A/G polymorphism on the occurrence of insulin resistance in chronic hepatitis C patients.
Fang LI ; Yingying ZHENG ; Cuiping SHAO ; Xiaohong FAN ; Lifen WANG ; Na HUO ; Haiying LU ; Chihong WU ; Xiaoyuan XU
Chinese Journal of Hepatology 2015;23(3):171-174
OBJECTIVETo study the mechanism underlying the effect of the SOCS3 rs4969170 A/G alleles on the occurrence of insulin resistance (IR) in patients with chronic hepatitis C.
METHODSThe promoter region of the SOCS3 gene was amplified by PCR,and luciferase expression vectors were constructed and transfected into HepG2,Huh7 cell lines.The relative luciferase activity of each expression vector was assessed by the dual luciferase reporter gene assay system.Western blotting was used to detect SOCS3 protein expression in PBMCs from groups of patients with the rs4969170 AA and AG genotypes.The state of IR in eight patients was evaluated by determining their HOMA-IR.
RESULTSThe pGL3-A, PGL3-G and pGL3-control vectors showed significantly different luciferase expression in the HepG2 cells (0.121 00 ± 0.022 07,0.027 00+/-0.012 49 and 0.043 33 ± 0.005 51; F =48.068, P=0.001) and in the Huh7 cell lines (0.164 70 ± 0.007 10,0.027 33 ± 0.017 04 and 0.033 67 ± 0.014 98; F =115.137, P=0.001). The expression of SOCS3 protein was significantly higher in the rs4969170 AA genotype group than in the AG genotype group (1.22 ± 0.40 vs. 0.30 ± 0.19; t =4.149, P=0.006).The IR index of patients with the rs4969170 AA genotype and the AG genotype was 4.11 ± 2.62 and 1.47 ± 1.01 respectively.There were three patients with IR in the rs4969170 AA genotype group and one in the rs4969170 AG group. There was no statistically significant difference between the two genotype groups (t=1.881, P=0.109).
CONCLUSIONSThe SOCS3 rs4969170 A haplotype may enhance transcriptional activity of the gene promoter to regulate gene expression, thereby increasing intracellular SOCS3 protein level and ultimately interfering with insulin signaling and causing IR in patients with chronic hepatitis C.
Cell Line, Tumor ; Genes, Reporter ; Genotype ; Haplotypes ; Hepatitis C, Chronic ; Humans ; Insulin Resistance ; Luciferases ; Polymorphism, Single Nucleotide ; Suppressor of Cytokine Signaling 3 Protein ; Suppressor of Cytokine Signaling Proteins
10.MreBCD-associated Cytoskeleton is Required for Proper Segregation of the Chromosomal Terminus during the Division Cycle of Escherichia Coli.
Yu-Jia HUO ; Ling QIAO ; Xiao-Wei ZHENG ; Cheng CUI ; Yuan-Fang MA ; Feng LU
Chinese Medical Journal 2015;128(9):1209-1214
BACKGROUNDIn prokaryotic organisms, the mechanism responsible for the accurate partition of newly replicated chromosomes into daughter cells is incompletely understood. Segregation of the replication terminus of the circular prokaryotic chromosome poses special problems that have not previously been addressed. The aim of this study was to investigate the roles of several protein components (MreB, MreC, and MreD) of the prokaryotic cytoskeleton for the faithful transmission of the chromosomal terminus into daughter cells.
METHODSStrain LQ1 (mreB::cat), LQ2 (mreC::cat), and LQ3 (mreD::cat) were constructed using the Red recombination system. LQ11/pLAU53, LQ12/pLAU53, LQ13/pLAU53, LQ14/pLAU53, and LQ15/pLAU53 strains were generated by P1transduction of (tetO) 240 -Gm and (lacO) 240 -Km cassettes from strains IL2 and IL29. Fluorescence microscopy was performed to observe localization pattern of fluorescently-labeled origin and terminus foci in wild-type and mutant cells. SOS induction was monitored as gfp fluorescence from PsulA-gfp in log phase cells grown in Luria-Bertani medium at 37°C by measurement of emission at 525 nm with excitation at 470 nm in a microplate fluorescence reader.
RESULTSMutational deletion of the mreB, mreC, or mreD genes was associated with selective loss of the terminus region in approximately 40% of the cells within growing cultures. This was accompanied by significant induction of the SOS DNA damage response, suggesting that deletion of terminus sequences may have occurred by chromosomal cleavage, presumably caused by ingrowth of the division septum prior to segregation of the replicated terminal.
CONCLUSIONSThese results imply a role for the MreBCD cytoskeleton in the resolution of the final products of terminus replication and/or in the specific movement of newly replicated termini away from midcell prior to completion of septal ingrowth. This would identify a previously unrecognized stage in the overall process of chromosome segregation.
Chromosome Segregation ; genetics ; physiology ; Cytoskeleton ; metabolism ; Escherichia coli ; genetics ; metabolism

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