Vitamin B6 and colorectal cancer:Current evidence and future directions

Colorectal cancer remains the third most common cancer in both women and men worldwide.Identifying modifiable dietary factors is crucial in developing primary prevention strategies.Vitamin B6 is involved in more than 100 coenzyme reactions,and may influence colorectal cancer risk in multiple ways including through its role in one-carbon metabolism related DNA synthesis and methylation and by reducing inflammation,cell proliferation,and oxidative stress.Observational studies of dietary or dietary plus supplementary intake of vitamin B6 and colorectal cancer risk have been inconsistent with most studies reporting nonsignificant positive or inverse associations.However,published studies of plasma pyridoxal 5'-phosphate(the active form of vitamin B6) levels consistently support an approximately 30%-50% reduction in risk of colorectal cancer comparing high with low concentrations.The reasons for the discrepancy in the results between dietary-based and plasma-based studies remain unresolved.Other unresolved questions include the effects of vitamin B6 intake in early life(i.e.,childhood or adolescence) and of suboptimal vitamin B6 status on colorectal cancer risk,whether the associations with vitamin B6 differ across molecular subtypes of colorectal cancer,and whether the vitamin B6-colorectal cancer association is modified by genetic variants of one-carbon metabolism.

Influence of folic acid and vitamin B12 combined therapy on plasma Hcy, inflammatory factor levels and blood vessels endothelial function in patients with vascular dementia and type H hypertension

Objective:To investigate influence of folic acid and vitamin B12 combined therapy on plasma homocysteine (Hcy) level, blood vessels endothelial function and inflammatory factors in patients with vascular dementia and type H hypertension.Methods:100 cases of patients with vascular dementia and type H hypertension accorded with the inclusion criteria were selected as research objects. They were randomly divided as the control group and the therapeutic group, 50 cases each. For control group, Enalapril tablets were administered by mouth for treatment. For therapeutic group, folic acid and vitamin B12 treatment were provided on the basis of treatment for control group. Treatments were continued for 12 weeks. Plasma Hcy levels, inflammatory factors [(interleukin-6 (IL-6), interleukin-8 (IL-8) and hypersensitive C reaction protein (hs-CRP)], blood vessels endothelial function indexes variation in patients before and after treatment were observed and detected.Results:Plasma Hcy, IL-6, IL-8 and hs-CRP levels in two groups of patients after treatment were significantly decreased comparing with the same group before treatment, and the above index levels in therapeutic group after treatment were significantly lower than control group (P<0.05);For comparison of blood vessels endothelial function indexes in the patients, NO levels in two groups after treatment were increased in various degrees, and endothelin-1 (ET-1) were decreased. The differences between levels of the two indexes in therapeutic group before and after treatment were significant, and levels after treatment in therapeutic group were significantly better than in control group (P<0.05). While variations of the differences in control group before and after treatment were not significant (P>0.05);After treatment, diastolic pressure and systolic pressure in the two groups of patients were significantly improved comparing with before treatment (P<0.05). However, after treatment, the differences of levels between therapeutic group and control group were not significant (P>0.05). MMSE score in therapeutic group after treatment was significantly higher than before treatment, and significantly higher than in control group (P<0.05).Conclusions: Combined therapy of folic acid and vitamin B12 for treating vascular dementia with type H hypertension could effectively decrease plasma Hcy and inflammatory factor levels, and improve blood vessels endothelial function and dementia degree on patients. It has certain clinical value which deserves to be promoted.

Vitamin B12 deficiency in dialysis patients:risk factors,diagnosis,complications,and treatment:A comprehensive review

Vitamin B12 deficiency is a significant concern among patients with end-stage renal disease undergoing dialysis.However,there hasn’t been extensive research conducted on this particular patient group.The reported incidence rates vary widely,ranging from 20%to 90%,reflecting the complexity of its diagnosis.Dialysis patients often face multiple nutritional deficiencies,including a lack of essential vitamins,due to factors such as dietary restrictions,impaired absorption,and nutrient loss during dialysis.Diagnosing vitamin B12 deficiency in these patients is challenging,and addressing it is crucial to prevent complications and improve their overall quality of life.This review paper delves into the available body of evidence on vitamin B12 deficiency in dialysis patients,examining the contributing risk factors,diagnostic challenges,potential complications,and available treatment options.It provides a well-rounded perspective on the topic,making it a valuable resource for researchers,healthcare practitioners,and policymakers interested in addressing the nutritional needs of dialysis patients.

Post-Marketing Surveillance of Fixed Dose Combination of Methylcobalamin, Alpha Lipoic Acid, Folic Acid, Biotin, Benfotiamine &Vitamin B6-Nutripathy for the Management of Peripheral Neuropathy

Background: Peripheral neuropathy is a commonly encountered troublesome condition which is often disabling & worsens when left untreated. Traditional neuropathic pain medications primarily provide symptomatic relief;however, the pathogenesis of nerve damage remains unresolved. Extensive literature survey reveals that patients with peripheral neuropathy experience significant benefits with the use of B-vitamins like methylcobalamin (B12), folic acid (B9), biotin (B7), benfotiamine (B1) and pyridoxine (B6). The other well documented antineuropathic agents include alpha lipoic acid, glutathione, omega fatty acids, myoinositol, certain trace elements, etc. Materials and Methods: A multicentre, prospective, open-label, non-comparative clinical study was carried out in 497 patients with peripheral neuropathy. A fixed dose combination of methylcobalamin, alpha lipoic acid (ALA), folic acid, biotin, benfotiamine & vitamin B6 capsule was orally administered once daily for 12 weeks. Results: Treatment led to significant reduction from baseline score in various neuropathy symptoms from the 4th week itself. After 12 weeks of treatment, the mean pain score declined by 78.0%, numbness by 92.1% and muscle weakness by 96.9%. Also, there was 96.0% & 99.2% reduction in tingling & burning sensation respectively. No serious adverse events were reported.Conclusion: The current study confirms that fixed dose combination of methylcobalamin, ALA, folic acid, biotin, benfotiamine & vitamin B6 is effective & well tolerated in the management of peripheral neuropathy.

乳铁素B的抗菌活性及其影响因素

乳铁素B是牛乳铁蛋白经胃蛋白酶酶解后得到的最重要的抗菌肽,具有较强抗菌活性. 研究表明,乳铁素B对大肠杆菌的最小抑菌质量浓度为0.5 mg/mL,对金黄色葡萄球菌的最小抑菌浓度为0.4 mg/mL;葡萄糖、蔗糖、麦芽糖、牛血清白蛋白(BSA)、尿素、硫酸铵在0～10 mg/mL,乳糖、可溶性淀粉在0～4 mg/mL的质量浓度范围内,对乳铁素B的抗菌活性影响不大;当NaCl或KCl的浓度为25～100 mmol/L,MgCl2或CaCl2的浓度为1.0～5.0 mmol/L时,乳铁素B的抗菌活性就会大大降低;随着缓冲盐浓度和有机酸浓度(25～100 mmol/L)的增大,乳铁素B的抗菌活性呈下降趋势,且在微碱性环境下乳铁素B表现出较强的抗菌活力.

Long-term metformin therapy and vitamin B12 deficiency: An association to bear in mind

To date,metformin remains the first-line oral glucose-lowering drug used for the treatment of type 2 diabetes thanks to its well-established long-term safety and efficacy profile.Indeed,metformin is the most widely used oral insulinsensitizing agent,being prescribed to more than 100 million people worldwide,including patients with prediabetes,insulin resistance,and polycystic ovary syndrome.However,over the last decades several observational studies and meta-analyses have reported a significant association between long-term metformin therapy and an increased prevalence of vitamin B12 deficiency.Of note,evidence suggests that long-term and high-dose metformin therapy impairs vitamin B12 status.Vitamin B12(also referred to as cobalamin)is a water-soluble vitamin that is mainly obtained from animal-sourced foods.At the cellular level,vitamin B12 acts as a cofactor for enzymes that play a critical role in DNA synthesis and neuroprotection.Thus,vitamin B12 deficiency can lead to a number of clinical consequences that include hematologic abnormalities(e.g.,megaloblastic anemia and formation of hypersegmented neutrophils),progressive axonal demyelination and peripheral neuropathy.Nevertheless,no definite guidelines are currently available for vitamin B12 deficiency screening in patients on metformin therapy,and vitamin B12 deficiency remains frequently unrecognized in such individuals.Therefore,in this“field of vision”article we propose a list of criteria for a cost-effective vitamin B12 deficiency screening in metformin-treated patients,which could serve as a practical guide for identifying individuals at high risk for this condition.Moreover,we discuss additional relevant topics related to this field,including:(1)The lack of consensus about the exact definition of vitamin B12 deficiency;(2)The definition of reliable biomarkers of vitamin B12 status;(3)Causes of vitamin B12 deficiency other than metformin therapy that should be identified promptly in metformin-treated patients for a proper differential diagnosis;and(4)Potential pathophysiological mechanisms underlying metformin-induced vitamin B12 deficiency.Finally,we briefly review basic concepts related to vitamin B12 supplementation for the treatment of vitamin B12 deficiency,particularly when this condition is induced by metformin.

Plasma Accumulations of Vitamin B6 from an Oral Dose in a New Reversible Model for Mouse Gut Injury and Regeneration

Chemically based rodent models are used to assess the positive effects promoted by foods and gut microbiota on gut health. Lectins with enzymatic activity, such as type 2 ribosome-inactivating proteins, might also prove useful for exploring these issues. Sub-lethal doses of the lectin nigrin from Sambucus nigra L. to mice promoted reversible derangement of gut epithelium by induction of apoptosis of transit amplifying cells of the small intestine crypts in a time-dependent course. The present work seeks to study vitamin B6 accumulation in plasma from an oral bolus in a mouse nigrin model. 24 h after sub-lethal nigrin b treatment, there was clear body weight reduction associated to a notable increase in Evan’s blue stain accumulation in excised small intestine, an increase in myeloperoxidase activity, and a near 50% reduction in plasma accumulation of vitamin B6. Histological analysis of small intestine sections of nigrin b-treated animals also revealed significant derangement of intestinal crypts. Seventy two hours after nigrin b treatment, stain uptake decreased and vitamin B6 accumulation was almost restored despite villi derangement. Large intestine crypts were scarcely or not at all affected. Eight days after nigrin b treatment, vitamin B6 uptake and intestinal crypt structure had fully recovered. The nigrin b mice model supports the view that, under these conditions, the carrier-mediated vitamin B6 uptake component of the small intestine crypts is probably the most active when the vitamin is administered orally as a bolus. The findings provide insights into the suitability of the present mice model for nutritional or drug absorption studies in conditions of partially altered or injured intestinal mucosa.

Fast Determination of Vitamin B₂Based on Molecularly Imprinted Electrochemical Sensor

Under the condition of weak acidity of pH 5.2, a sensitive vitamin B2 electrochemical sensor based on molecularly imprinted nonconducting polymer of o-aminophenol by potentiostatic polymerization in the presence of template(vitamin B2) on a glassy carbon electrode was prepared, and its performance was studied. The sensor exhibited good sensitivity and selectivity to VB2. The detection limit went down to 2.3851nM, and a linear relationship between the current incremental and the concentration was found in the range of 10~120nM. And the sensor could use in detection of VB2 real sample for a long time and show good reproducibility. The average recovery rate to VB2 was 98.41%.

B→O血型转换批量制备通用型红细胞的研究

目的建立B→O血型转换红细胞(通用型红细胞)批量制备工艺,为临床提供通用型红细胞制品。方法用不同pH值的缓冲液对1个使用单位(200ml)的B型红细胞进行预处理。在专门设计的转型密闭处理系统中,用α半乳糖苷酶对B型红细胞表面B抗原进行酶解,并检测酶解后红细胞ABO血型抗原及结构、功能。结果酶解前用pH4.2缓冲液预处理组上清游离Hb含量显著低于pH2.8缓冲液处理组;经α半乳糖苷酶(100Uml红细胞)在pH5.6,26℃条件下酶解60min,红细胞B型抗原被完全清除,转换为O型;红细胞形态、变形性、ATP、2,3DPG、胆固醇含量、乙酰胆酐酯酶活性、渗透脆性、pH、上清游离Hb、K+、Na+含量与对照组(正常红细胞)比较差异无显著意义,均在正常范围。结论建立了B→O血型转换通用型红细胞的批量制备工艺。通用型红细胞结构、功能、形态均正常,细菌、热原实验合格。

神经胶质瘤中缓激肽B_(2)受体的表达水平与病理级别的相关性

目的分析神经胶质瘤中缓激肽B2受体表达水平与病理分级的相关关系,为缓激肽及其类似物的临床应用提供实验依据.方法采用神经胶质瘤患者术后标本,用H&E染色进行神经胶质瘤的病理诊断及分级,用免疫组化法和Western Blot法测定不同病理分级的神经胶质瘤中缓激肽B2受体的表达水平.结果H&E染色显示26例神经胶质瘤中Ⅰ级为9例,Ⅱ级为9例,Ⅲ级为8例,Ⅳ级为0例.胶质瘤边缘水肿带不表达缓激肽B2受体,B2受体位于胶质瘤细胞.Western Blot结果显示在三组不同病理分级的神经胶质瘤中,B2受体表达水平为Ⅰ级与Ⅱ级(39480.88±5119.96对51354.25±6168.77,n=8,t=2.447,P＜0.05),Ⅰ级与Ⅲ级(39480.88±5119.96对73032.13±8802.71,n=8,t=7.710,P＜0.001),Ⅱ级与Ⅲ级(51354.25±6168.77对73032.13±8802.71,n=8,t=5.704,P＜0.001);神经胶质瘤中缓激肽B2受体表达水平与其病理分级Ⅰ级～Ⅲ级呈显著正相关(r=0.895,P＜0.001),呈Ⅰ级＜Ⅱ级＜Ⅲ级状况.免疫组化法显示在三组不同病理分级的神经胶质瘤中,B2受体阳性区域面积占切片面积的百分比值为Ⅰ级与Ⅱ级(3.54%±1.51%对8.47%±3.45%,n=8,t=3.698,P＜0.01),Ⅰ级与Ⅲ级(3.54%±1.51%对15.94%±1.68%,n=8,t=15.562,P＜0.001),Ⅱ级与Ⅲ级(8.47%±3.45%对15.94%±1.68%,n=8,t=5.505,P＜0.001);神经胶质瘤中缓激肽B2受体阳性区域面积占切片面积的百分比值与其病理分级Ⅰ级～Ⅲ级呈显著正相关(r=0.878,P＜0.001),呈Ⅰ级＜Ⅱ级＜Ⅲ级状况.结论神经胶质瘤B2受体表达水平与其病理分级Ⅰ级～Ⅲ级呈显著正相关,提示利用缓激肽及其类似物开放血肿瘤屏障的疗效差异可能与B2受体表达水平有关.

Voltammetric Determination of Vitamin B6 at Glassy Carbon Electrode Modified with Gold Nanoparticles and Multi-Walled Carbon Nanotubes

In this work, the gold nanoparticles (Au NPs)/multi-walled carbon nanotubes (MWCNTs) composite film modified glassy carbon electrode (GCE) was fabricated, and scanning electron microscopy (SEM) was used to investigate the assemble process of the composite film. In pH 7.0 PBS, a oxidation peak of the vitamin B6 (VB6) was only observed at composite film modified electrode. Under the optimized conditions, the current intensity was linear with the concentrations of VB6 in the range of 1.59 to 102.74 μg●mL–1 with a detection limit of 0.53 μg●mL–1 (S/N = 3). The modified electrode had been applied in medication analysis, and obtained good results.

Association of Serum Folate and Vitamin B_(12) Concentrations with Obesity in Chinese Children and Adolescents

Objective This study aimed to evaluate the associations of serum folate and/or vitamin B12 concentrations with obesity among Chinese children and adolescents.Methods A cross-sectional study was conducted including 3,079 Chinese children and adolescents,aged 6 to 17 years,from Jiangsu,China.Anthropometric indices,such as,children's body mass index(BMI),BMI z-scores,waist circumference,and waist-to-height ratio were utilized.Multivariable linear regression and generalized additive models were used to investigate the associations of serum folate and vitamin B12 levels with anthropometric indices and odds of obesity.Results We observed that serum vitamin B12 concentrations were inversely associated with all anthropometric indices and the odds of general obesity[odds ratio(OR)=0.68;95%confidence interval(CI)=0.59,0.78]and abdominal obesity(OR=0.68;95%CI=0.60,0.77).When compared to participants with both serum vitamin levels in the two middle quartiles,those with both serum folate and vitamin B12 levels in the highest quartile were less prone to general(OR=0.31,95%CI=0.19,0.50)or abdominal obesity(OR=0.46,95%CI=0.31,0.67).Conversely,participants with vitamin B12 levels in the lowest quartile alongside folate levels in the highest quartile had higher odds of abdominal obesity(OR=2.06,95%CI=1.09,3.91).Conclusion Higher serum vitamin B12 concentrations,but not serum folate concentrations,were associated with lower odds of childhood obesity.Children and adolescents with high levels of vitamin B12 and folate were less likely to be obese.

Diagnostic value of gamma-glutamyltransferase/aspartate aminotransferase ratio, protein induced by vitamin K absence or antagonist II, and alpha-fetoprotein in hepatitis B virus-related hepatocellular carcinoma

BACKGROUND Researchers have investigated the diagnostic value of protein induced by vitamin K absence or antagonist II (PIVKA-II) and alpha-fetoprotein (AFP) in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), and obtained abundant clinical diagnostic data. However, PIVKA-II and AFP have unsatisfactory specificity and sensitivity in the diagnosis of early-stage HBV-related HCC. Gamma-glutamyltransferase (γ-GT) and aspartate aminotransferase (AST) are common biomarkers for evaluating liver function, and we hypothesized that the γ-GT/AST ratio in combination with PIVKA-II and AFP would improve the diagnosis of early-stage HBV-related HCC. AIM To evaluate the diagnostic value of γ-GT/AST ratio alone or in combination with PIVKA-II and AFP in HBV-related HCC. METHODS Serum levels of γ-GT, AST, PIVKA-II, and AFP were detected and analysed in 176 patients with HBV-related HCC and in 359 patients with chronic hepatitis B. According to tumour size and serum level of HBV DNA, HBV-related HCC patients were divided into the following categories: Early-stage HCC patients, HCC patients, HBV DNA positive (HBV DNA+) HCC patients, and HBV DNA negative (HBV DNA-) HCC patients. Receiver-operating characteristic (ROC) curves were used to analyse and compare the diagnostic value of the single and combined detection of various biomarkers in different types of HBV-related HCC. RESULTS Tumour size was positively correlated with serum levels of PIVKA-II and AFP in HCC patients (r = 0.529, aP < 0.001 and r = 0.270, bP < 0.001, respectively), but there was no correlation between tumour size and the γ-GT/AST ratio (r = 0.073, P = 0.336). The areas under the receiver-operating characteristic curves (AUROCs) of the γ-GT/AST ratio in early-stage HCC patients, HBV DNA+ HCC patients and HBV DNA- HCC patients were not significantly different from that in the total HCC patients (0.754, 0.802, and 0.705 vs 0.779, respectively;P > 0.05). When PIVKA-II was combined with the γ-GT/AST ratio in the diagnosis of earlystage HCC, HCC, and HBV DNA+ HCC, the AUROCs of PIVKA-II increased, with values of 0.857 vs 0.835, 0.925 vs 0.913, and 0.958 vs 0.954, respectively. When AFP was combined with the γ-GT/AST ratio in the diagnosis of early-stage HCC, HCC, HBV DNA+ HCC, and HBV DNA- HCC, the AUROCs of AFP increased, with values of 0.757 vs 0.621, 0.837 vs 0.744, 0.868 vs 0.757, and 0.840 vs 0.828, respectively. CONCLUSION The γ-GT/AST ratio may be better than PIVKA-II and AFP in the diagnosis of early-stage HBV-related HCC, and its combination with PIVKA-II and AFP can improve the diagnostic value for HBV-related HCC.

华支睾吸虫卵黄前体蛋白B基因的识别、序列分析和克隆表达

为识别和克隆华支睾吸虫新基因 ,对华支睾cDNA质粒文库进行随机筛选并测序 ,并利用在线生物信息学工具进行序列分析 ,识别华支睾吸虫未知基因 ,同时根据PGEX -4T- 1多克隆位点及未知基因的序列设计引物 ,PCR扩增目的基因 ,并构建原核重组质粒。结果发现了CsvpB基因 ,其完整阅读框含 76 2个碱基 ,编码 2 5 4个氨基酸 ,理论分子量为 2 7. 7kDa。序列分析表明 ,CsvpB蛋白与其它物种的卵黄前体蛋白有较高的同源性 ,所构建的重组原核表达质粒PGEX- 4T- 1 vpB经PCR、双酶切及测序证实与目标基因相符。

Relationship of serum folic acid and vitamin B12 contents with maternal endothelial injury and placental ischemia hypoxia in patients with preeclampsia

Objective:To investigate the relationship of serum folic acid and vitamin B12 contents with maternal endothelial injury and placental ischemia hypoxia in patients with preeclampsia. Methods:A total of 76 puerperae with preeclampsia who gave birth in this hospital between March 2016 and October 2017 were selected as the preeclampsia group, and 100 healthy puerperae who gave birth in this hospital during the same period were selected as the normal control group. The differences in serum contents of folic acid, vitamin B12, endothelial injury indexes and oxidative stress indexes were compared between the two groups 24 h before delivery. Pearson test was used to assess the intrinsic relationship of serum folic acid and vitamin B12 contents with the disease severity in puerperae with preeclampsia.Results:Serum folic acid and vitamin B12 contents of preeclampsia group were lower than those of control group;endothelial injury markers sEng, sFlt-1, ET-1 and TM contents were higher than those of control group whereas ADM content was lower than that of control group;oxidative stress indexes AOPPs and LHP contents were higher than those of normal control group whereas T-AOC content was lower than that of control group. The Pearson test showed that serum folic acid and vitamin B12 contents in puerperae with preeclampsia were directly correlated with vascular endothelial injury and placental ischemia hypoxia.Conclusion: There is folic acid and vitamin B12 deficiency in patients with preeclampsia, and it can aggravate the vascular endothelial injury and placental ischemia hypoxia.

露螽属四种昆虫Cy tb基因序列及系统进化研究(直翅目,露螽科)

研究了露螽属4种昆虫线粒体细胞色素b基因(Cytb)的部分序列,分析了核苷酸序列组成与变异及氨基酸差异。在得到的4 32bp序列中,A +T约占6 6 9% ,其中10 2个核苷酸位点发生了变异(约2 3 8% ) ,从每个氨基酸密码子来看,第3位点的A +T含量较高,为79 7%。Cytb基因编码的14 4个氨基酸由19种氨基酸组成,有12个发生了变异,占氨基酸总数的8 33% ,其中亮氨酸(Leu)与苯丙氨酸(Phe)的含量较高,谷氨酸(Glu)、赖氨酸(Lys)与精氨酸(Arg)的含量较低,无半胱氨酸(Cys)。以日本纺织娘和中华螽斯为外群构建的NJ分子系统树显示,镰尾露螽与齿尾露螽是分化较晚的类群,其次是瘦露螽,黑角露螽是分化较早的类群。

Metabolic syndrome:A review of the role of vitamin D in mediating susceptibility and outcome

Despite the well-recognised role of vitamin D in a wide range of physiological processes,hypovitaminosis is common worldwide(prevalence 30%-50%) presumably arising from inadequate exposure to ultraviolet radiation and insufficient consumption.While generally not at the very low levels associated with rickets,hypovitaminosis D has been implicated in various very different,pathophysiological processes.These include putative effects on the pathogenesis of neoplastic change,inflammatory and demyelinating conditions,cardiovascular disease(CVD) and diabetes.This review focuses on the association between hypovitaminosis D and the metabolic syndrome as well as its component characteristics which are central obesity,glucose homeostasis,insulin resistance,hypertension and atherogenic dyslipidaemia.We also consider the effects of hypovitaminosis D on outcomes associated with the metabolic syndrome such as CVD,diabetes and non-alcoholic fatty liver disease.We structure this review into 3 distinct sections; the metabolic syndrome,vitamin D biochemistry and the putative association between hypovitaminosis D,the metabolic syndrome and cardiovascular risk.

一种新的B-Snake算法在目标轮廓跟踪中的应用

用Snake算法跟踪移动目标时,有时会产生目标轮廓与背景中另一些物体靠近的现象,如果不加约束,那么一些控制点将可能因被吸引到背景边缘而产生错误。另外,目标产生移动或旋转时,因轮廓控制点会产生交叉而导致轮廓跟踪失败。为克服此类问题,提出了一种新的有效的目标跟踪算法,可以跟踪静止或运动目标的2维轮廓曲线。该算法先利用三次B样条曲线连接控制点,以初始化物体的边界,然后通过Snake最小能量函数把控制点吸引到轮廓的边界。在Snake跟踪算法中,由于是采用和下一点相连向量与控制中心相连向量的夹角正弦值的正负来避免控制点的交叉,而控制中心的位置则通过αβγ滤波能有效地估计出来,因而能准确地跟踪运动的目标。该算法运用到静止的或移动的头部轮廓跟踪的实验证明,该算法不仅对目标轮廓跟踪具有较好的效果,且运算时间短、复杂度低。

重组人BAFF_(134～285)的克隆及在大肠杆菌中的高效表达

目的克隆人TNF家族的B细胞激活因子(BcellactivatingfactortotheTNFfamily,BAFF)胞外区cDNA,并进行高效表达和纯化。方法提取人新鲜扁桃体组织总RNA,经RTPCR扩增编码人BAFF胞外区134～285氨基酸残基cDNA,经序列测定后,克隆至pQE80L载体中,并转化大肠杆菌DH5α,经IPTG诱导表达及Ni2+NTA柱层析纯化目的蛋白,最后经SDSPAGE和Westernblot检测。结果RTPCR扩增得到了459bp的cDNA片段,序列分析与GenBank中报道的编码人BAFF134～285的cDNA序列一致,SDSPAGE及Westernblot证实表达蛋白确实为6×HisBAFF134～285融合蛋白,并存在于包涵体中。结论利用大肠杆菌可高效表达rhBAFF134285,为进一步研究其生物学活性奠定了基础。

Effects of folic acid and vitamin B12 adjuvant therapy on serum inflammatory cytokines, Hcy and NT-proBNP in elderly patients with coronary heart disease and chronic heart failure

Objective:To investigate the effect of folic acid combined with vitamin B12 supplementation with conventional drugs on the levels of serum inflammatory factors, Hcy and NT-proBNP in elderly patients with chronic heart failure.Methods:89 elderly patients with chronic heart failure were randomly divided into control group (n=47) and observation group (n=42) based on the random data table. The control group was given diuretics, ACEI andβ receptor inhibitor group of three categories of drugs combined treatment, on this basis, the observation group supplemented by folic acid tablets and vitamin B12 treatment, both groups were treated for 8 weeks. The levels of TNF-α, hs-CRP and visfatin, Hcy and NT-proBNP were measured before and after treatment in both groups.Results: There was no significant difference in TNF-α, hs-CRP, visfatin, Hcy and NT-proBNP between the control group and the observation group before treatment. After treatment, the levels of TNF-α, hs-CRP, visfatin, Hcy and NT-proBNP in the two groups decreased significantly ,the difference was significant, the level of the above indexes of the observation group after treatment was significantly lower than that of the control group ,the difference was statistically significant.Conclusion: Folic acid combined with vitamin B12 can reduce the levels of serum inflammatory factors, Hcy and NT-proBNP in elderly patients with coronary heart disease and heart failure, which has certain clinical value.