高效液相色谱法测定孕妇血清中色氨酸及其代谢产物Kynurenine

[目的]建立一种高效液相色谱法测定孕妇血清中的色氨酸（Tyrptophan）及其代谢产物Kynurenine的方法。[方法]反相高效液相色谱法。外标法，ZORBAX Extend-C18柱，4．6mmID×250mm，流动相为甲醇：0．001mol／L磷酸二氢钾（采用PH=4）（12：88），流速1．3ml／min，检测波长245nm。[结果]色氨酸线性范围2．56～307．06μmol／L，r=0．9999；Kynurenine线性范围0．12～5．05μmol／L，r=0．9997。30例孕妇血清色氨酸为49．73±7．48μmol／L，其代谢产物KN为：0．74±0．33μmol／L。[结论]本法简便，准确，适用于临床和科研。

Helicobacter pylori and serum kynurenine-tryptophan ratio in patients with colorectal cancer

AIM: To evaluate how Helicobacter pylori(H. pylori) is able to evade the immune response and whether it enhances systemic immune tolerance against colorectal cancer.METHODS: This prospective randomized study involved 97 consecutive colorectal cancer patients and 108 cancer-free patients with extra-digestive diseases. Colorectal cancer and cancer-free patients were assigned into subgroups according to H. pylori Ig G seropositivity. Exposure to H. pylori was determined by Ig G seropositivity which was detected by enzyme linked immunoassay(ELISA). Serum neopterin levels were measured by ELISA. Serum tryptophan, kynurenine, and urinary biopterin concentrations were measured by high performance liquid chromatography. Serum nitrite levels were detected spectrophotometrically. Serum indoleamine 2,3-dioxygenase activity was estimated by the kynurenine to tryptophan ratio and by assessing the correlation between serum neopterin concentrations and the kynurenine to tryptophan ratio. The frequencies of increased serum kynurenine to tryptophan ratio of H. pylori seronegative and seropositive colorectal cancer subgroups were estimated by comparing them with the average kynurenine to tryptophan ratio of H. pylori seronegative tumor-free patients.RESULTS: Compared with respective controls, in both H. pylori seronegative and seropositive colorectal cancer patients, while serum tryptophan levels were decreased(controls vs patients; seronegative: 20.37 ± 0.89 μmol/L vs 15.71 ± 1.16 μmol/L, P < 0.05; seropositive: 20.71 ± 0.81 μmol/L vs 14.97 ± 0.79 μmol/L, P < 0.01) the kynurenine to tryptophan ratio was significantly increased(controls vs patients; seronegative: 52.85± 11.85 μmol/mmol vs 78.91 ± 8.68 μmol/mmol, P < 0.01, seropositive: 47.31 ± 5.93 μmol/mmol vs 109.65 ± 11.50 μmol/mmol, P < 0.01). Neopterin concentrations in cancer patients were significantly elevated compared with controls(P < 0.05). There was a significant correlation between serum neopterin levels and kynurenine/tryptophan in control and colorectal cancer patients groups(r s = 0.494, P = 0.0001 and r s= 0.293, P = 0.004, respectively). Serum nitrite levels of H. pylori seropositive cancer cases were significantly decreased compared with seropositive controls(controls vs patients; 26.04 ± 2.39 μmol/L vs 20.41 ± 1.48 μmol/L, P < 0.05) The decrease in the nitrite levels of H. pylori seropositive cancer patients may be attributed to excessive formation of peroxynitrite and other reactive nitrogen species.CONCLUSION: A significantly high kynurenine/tryptophan suggested that H. pylori may support the immune tolerance leading to cancer development, even without an apparent upper gastrointestinal tract disease.

大电流KYN28型高压开关柜改善温升解决方法

为解决大电流KYN28型高压开关柜温升发热问题,分析了该开关柜的温升发热机理,确定了主回路内阻、接触电阻、感应电阻3个发热源,并计算了发热的总功率。采用增大配电柜两侧散热面积、增大配电柜通风口面积、强制对流风冷、柜体内风道设计改进等措施,平衡发热功率,使散热功率大于发热的总功率。在实验室使用HZDL-WS-6300/12全自动温升试验系统进行测量,在符合标准规定的环境下,测得温升下降约10%,得到明显改善,总体结果基本符合预期。证明所提措施可以解决温升问题,并认为解决温升问题时需要结合设备运行,实时监视温升情况,以确保设备运行安全。

Inhibiting the kynurenine pathway in spinal cord injury: multiple therapeutic potentials?

Chronic induction of the kynurenine pathway（KP） contributes to neuroinflammation by producing the excitotoxin quinolinic acid（QUIN）. This has led to significant interest in the development of inhibitors of this pathway, particularly in the context of neurodegenerative disease. However, acute spinal cord injury（SCI） also results in deleterious increases in QUIN, as secondary inflammatory processes mediated largely by infiltrating macrophages, become predominant. QUIN mediates significant neurotoxicity primarily by excitotoxic stimulation of the N-methyl-D-aspartate receptor, but other mechanisms of QUIN toxicity are known. More recent focus has assessed the contribution that neuroinflammation and modulations in the KP make in mood and psychiatric disorders with recent studies linking inflammation and modulations in the KP, to impaired cognitive performance and depressed mood in SCI patients. We hypothesize that these findings suggest that in SCI, inhibition of QUIN production and other metabolites, may have multiple therapeutic modalities and further studies investigating this are warranted. However, for central nervous system-based conditions, achieving good blood-brain-barrier permeability continues to be a limitation of current KP inhibitors.

Kynurenine plays an immunosuppressive role in 2,4,6-trinitrobenzene sulfate-induced colitis in mice

BACKGROUND Inflammatory bowel disease,such as Crohn’s disease and ulcerative colitis,is characterized by chronic intestinal inflammation leading to intestinal mucosal damage.Inflammatory bowel disease causes dysregulation of mucosal T cell responses,especially the responses of CD4+T cells.Previously,we demonstrated that indoleamine-2,3-dioxygenase plays an immunosuppressive role in 2,4,6-trinitrobenzene sulfate(TNBS)-induced colitis.Although indoleamine-2,3-dioxygenase exerts immunosuppressive effects by altering the local concentration of tryptophan(Trp)and immunomodulatory Trp metabolites,the specific changes in immune regulation during colitis caused by Trp metabolites and its related enzymes remain unclear.AIM To investigate role of kynurenine 3-monooxygenase(KMO)in TNBS-induced colitis and involvement of Trp metabolites in maintenance of intestinal homeostasis.METHODS Colitis was induced in eight-week-old male KMO+/+or KMO−/−mice of C57BL/6N background using TNBS.Three days later,the colon was used for hematoxylin-eosin staining for histological grading,immunohistochemical or immunofluorescence staining for KMO,cytokines,and immune cells.Inflammatory and anti-inflammatory cytokines were measured using quantitative RT-PCR,and kynurenine(Kyn)pathway metabolites were measured by high-performance liquid chromatography.The cell proportions of colonic lamina propria and mesenteric lymph nodes were analyzed by flow cytometry.RESULTS KMO expression levels in the colonic mononuclear phagocytes,including dendritic cells and macrophages increased upon TNBS induction.Notably,KMO deficiency reduced TNBS-induced colitis,resulting in an increased frequency of Foxp3+regulatory T cells and increased mRNA and protein levels of antiinflammatory cytokines,including transforming growth factor-βand interleukin-10.CONCLUSION Absence of KMO reduced TNBS-induced colitis via generation of Foxp3+regulatory T cells by producing Kyn.Thus,Kyn may play a therapeutic role in colon protection during colitis.

Kynurenine pathway metabolism and neuroinflammatory disease

Immune-mediated activation of tryptophan（TRYP） catabolism via the kynurenine pathway（KP） is a consistent finding in all inflammatory disorders.Several studies by our group and others have examined the neurotoxic potential of neuroreactive TRYP metabolites,including quinolinic acid（QUIN） in neuroinflammatory neurological disorders,including Alzheimer＇s disease（AD）,multiple sclerosis,amylotropic lateral sclerosis（ALS）,and AIDS related dementia complex（ADC）.Our current work aims to determine whether there is any benefit to the affected individuals in enhancing the catabolism of TRYP via the KP during an immune response.Under physiological conditions,QUIN is metabolized to the essential pyridine nucleotide,nicotinamide adenine dinucleotide（NAD＋）,which represents an important metabolic cofactor and electron transporter.NAD＋ also serves as a substrate for the DNA ‘nick sensor＇ and putative nuclear repair enzyme,poly（ADP-ribose） polymerase（PARP）.Free radical initiated DNA damage,PARP activation and NAD＋ depletion may contribute to brain dysfunction and cell death in neuroinflammatory disease.

Differences of Plasma Levels of Tryptophan, Serotonin, 5-Hydroxyindole Acetic Acid, and Kynurenine between Healthy People and Patients of Major Monopolar Depression at Various Age and Gender

Background: It is not well analyzed whether there are differences in plasma levels of tryptophan (TRP) metabolites between healthy control people (HC) and patients of major monopolar depression (MMD). Methods: Ultra high-speed liquid chromatography/mass spectrometry has been used for the simultaneous determination of plasma levels of tryptophan metabolites in depressive patients. Results: There are no significant differences between plasma levels of TRP between HC and MMD. Plasma levels of TRP of HC are higher in young men, young women, old men, and old women in this order. Serotonin (5-HT) levels are higher in MMD than HC. Plasma levels of 5-HIAA of HC are also higher than those of patients of MMD. Plasma levels of kynurenine (KYN) of healthy old men and old women are higher than those of young men and old women. Plasma levels of KYN are higher in old women and young men of MMD than those of HC. Conclusion: Plasma levels of 5-HT are higher in patients of MMD than those of HC, which may suggest that use of drugs inhibiting the 5-HT transportation may increase plasma levels of 5-HT in MMD.

Kynurenine pathway of tryptophan metabolism in pathophysiology and therapy of major depressive disorder

Serotonin deficiency in major depressive disorder(MDD)has formed the basis of antidepressant drug development and was originally attributed to induction of the major tryptophan(Trp)-degrading enzyme,liver Trp 2,3-dioxygenase(TDO),by cortisol,leading to decreased Trp availability to the brain for serotonin synthesis.Subsequently,the serotonin deficiency was proposed to involve induction of the extrahepatic Trp-degrading enzyme indoleamine 2,3-dioxygenase(IDO)by proinflammatory cytokines,with inflammation being the underlying cause.Recent evidence,however,challenges this latter concept,as not all MDD patients are immune-activated and,when present,inflammation is mild and/or transient.A wide range of antidepressant drugs inhibit the activity of liver TDO and bind specifically to the enzyme,but not to IDO.IDO induction is not a major event in MDD,but,when it occurs,its metabolic consequences may be masked and overridden by upregulation of kynurenine monooxygenase(KMO),the gateway to production of modulators of immune and neuronal functions.KMO appears to be activated in MDD by certain proinflammatory cytokines and antidepressants with anti-inflammatory properties may block this activation.We demonstrate the ability of the antidepressant ketamine to dock(bind)to KMO.The pathophysiology of MDD may be underpinned by both the serotonin deficiency and glutamatergic activation mediated respectively by TDO induction and N-methyl-D-aspartate receptor activation.Inhibition of TDO and KMO should be the focus of MDD pharmacotherapy.

温和灸对IBS小鼠结肠Trp-kyn/5-HT代谢的调控机制研究

目的 观察温和灸干预对肠易激综合征模型小鼠结肠组织Trp-Kyn/5-HT限速酶表达及相关代谢物含量的影响,阐释艾灸治疗相关机制。方法 雄性清洁级C57BL/6J小鼠随机分为正常组、模型组、艾灸组、1-MT组、PCPA组,采用AWR评价小鼠内脏高敏感状态,采用LC-MS/MS法、免疫组织化学法及Real Time PCR法分别检测小鼠结肠组织Trp-Kyn/5-HT代谢物含量、Trp-Kyn/5-HT代谢限速酶IDO1、TPH1蛋白及m RNA表达。结果 与正常组相比,模型组小鼠30 mm Hg下AWR评分增高(P <0.05),结肠组织TPH1、IDO1蛋白及m RNA表达显著增高(P <0.05),5-HT含量及Kyn/Trp比值显著升高(P <0.05)。与模型组相比,艾灸组和1-MT组小鼠结肠组织IDO1蛋白表达明显下调(P <0.05),艾灸组和PCPA组小鼠结肠组织TPH1蛋白明显下调(P <0.05);1-MT组小鼠结肠组织IDO1 mRNA表达明显降低(P <0.05),PCPA组小鼠结肠组织TPH1 mRNA表达明显降低(P <0.05);艾灸组Kyn/Trp比值显著降低(P <0.05)。结论 温和灸可抑制IBS小鼠结肠过表达的IDO1及THP1蛋白活性,下调Kyn/Trp比值,可能是温和灸改善IBS模型小鼠内脏痛敏的机制之一。

Research progress of kynurenine pathway in Alzheimer's disease

The kynurenine pathway(KP)has been shown to be involved in the pathophysiology of dementia diseases.Among the dementia diseases,the neurodegenerative diseases Alzheimer's disease and cerebrovascular diseases are vascular.The highest incidence of dementia.KP activation results in the production of neuroactive metabolites,which may interfere with normal neuronal function,leading to the appearance of symptoms of cognitive impairment.This review investigated KP's involvement in the neurological diseases Alzheimer's disease and vascular dementia,suggesting that KP is a potential therapeutic target for both diseases.

KYN28A-12型中置式开关柜标准化设计研究

为满足不同厂家设备在一定范围和一定时期的通用互换使用,提升开关柜设备的运维便利性,选择目前市场上应用较多且运行相对成熟可靠的KYN28A-12型中置式开关柜开展标准化设计研究,介绍了标准化设计的目的、设计思路、输入条件和主要设计内容。重点分析了KYN28A-12型中置式开关柜的典型方案确定,对一次接口及土建接口、二次接口以及关键元件的标准化设计原则及结果进行了详细说明,在满足配网设备需求的基础上兼顾变电站中配电设备的要求,提出了统一的标准化设计方案,为后续标准化建设工作提供重要支撑。

血清IDO和KYN在溃疡性结肠炎中的临床价值研究

目的检测吲哚胺2,3-双加氧酶(IDO)和犬尿氨酸(KYN)在溃疡性结肠炎(UC)患者中的表达水平,利用受试者工作特征(ROC)曲线分析血清IDO、KYN诊断活动期UC的价值。方法 60例UC组、18例疾病对照组和20例健康对照组。采用免疫组化法检测UC组结肠黏膜中IDO的表达,ELISA法检测3组血清中IDO、KYN和C反应蛋白(CRP)水平,利用ROC曲线进行分析。结果①UC组血清中IDO和KYN水平与结肠黏膜IDO表达量呈正相关(P<0.05);②UC组患者血清IDO及KYN水平高于疾病对照组和健康对照组(P<0.05);③UC组中,活动期患者血清IDO、KYN水平高于缓解期(P<0.01),并随炎症严重程度升高而升高;④活动期UC组IDO、KYN水平与疾病活动度、CRP水平呈正相关;⑤IDO、KYN、CRP的ROC曲线下面积分别为0.976、0.856和0.864;最佳截断值分别为53.66 U/L、2.34 nmol/L和1.75 mg/ml;灵敏度分别为90.5%、78.65%和100.0%;特异度分别为94.4%、83.3%和61.1%;Youden指数分别为0.849 2、0.619 0和0.611 1。结论UC患者血清IDO和KYN水平可以作为判断UC患者炎症程度的重要指标,血清IDO、KYN和CRP水平对活动期UC有重要的诊断价值,其中IDO诊断价值高于KYN和CRP。

培元解郁方对慢性应激BALB/c小鼠的抗抑郁作用及TRY-KYN代谢途径的调节

目的:研究四逆散、天丝饮、培元解郁方的抗抑郁作用及其对血清皮质酮含量和色氨酸(TRP)-犬尿氨酸(KYN)途径关键代谢酶色氨酸2,3-双加氧酶(TDO)的影响。方法:使用束缚加噪声造成小鼠抑郁模型,采用Noldus Etho Vision XT9系统采集分析小鼠强迫游泳不动时间,采用HPLC-MS/MS技术检测血清色氨酸(TRP)、犬尿氨酸(KYN)、犬尿烯酸(KA)、喹啉酸(Q)、皮质酮(C)含量,实时荧光定量PCR检测肝组织中TDO的mRNA表达水平。结果:束缚加噪声应激5d后可以引起模型组小鼠强迫游泳不动时间延长,血清皮质酮含量增高,KYN/TRP、KYN/KA比值升高,KYN/Q比值降低。四逆散、天丝饮、培元解郁方能缩短小鼠不动时间(P<0.01),降低血清皮质酮含量(P<0.05),提高KYN/TRP、KYN/Q比值(P<0.05),降低KYN/KA比值。结论:四逆散、天丝饮、培元解郁方具有抗抑郁药物样作用,这一作用与对抗应激引发的血清皮质酮升高,抑制色氨酸-犬尿氨酸代谢途径中的神经毒性代谢产物产生并提高神经保护作用有关。

KYN28A-12型高压开关柜接地刀闸的改造

通过对KYN28-10型手车式开关柜接地刀闸隐患的分析,找出了原因,提出了解决问题的方法,保证了高压开关柜的安全可靠运行。

KYN28-10型高压开关柜存在的问题及对策

对KYN28-10型高压开关柜存在的问题进行分析,找出原因并提出应对措施,保证了高压开关柜的安全可靠运行。

培元解郁方对急性应激BALB/c小鼠的抗抑郁作用及TRP-KYN代谢途径的调节

目的:研究培元解郁方的抗抑郁作用及其对色氨酸(Tryptophan,TRP)-犬尿氨酸(Kynurenine,KYN)途径的调节。方法:急性应激造成小鼠抑郁模型,采用Noldus Etho Vision XT9系统采集分析小鼠强迫游泳不动时间,采用HPLC-MS/MS技术检测脑组织色氨酸、犬尿氨酸含量,实时荧光定量PCR检测肝组织中色氨酸2,3-双加氧酶(Tryptophan 2,3-dioxygenaes,TDO)的mRNA表达水平。结果:急性应激可以引起小鼠不动时间延长,肝组织TDO活性增高,TDO mRNA表达增多。天丝饮、培元解郁方能缩短小鼠不动时间(P<0.05),降低TDOmRNA表达数量,天丝饮尚有明显的抑制喹啉酸(Quinolinic acid,Q)作用。结论:天丝饮、培元解郁方具有抗抑郁药物样作用,这一作用可能与减少急性应激后血清皮质酮(Corticosterone,C)的含量,降低TDOmRNA的表达有关;天丝饮表现出明显的抑制神经毒性的作用可能与调节KYN代谢产物有关。

10kV避雷器直连母线的KYN柜改造

针对某变电站10kV避雷器直连母线的KYN柜改造,提出三种改造方案,并对这三种方案进行比较,以确定最佳方案,最后介绍实施过程中的注意事项。

KYN28型高压开关柜二次回路的改进

10 kV KYN28型高压开关柜使用可更换的手车式断路器和微机继电保护装置,性能良好,应用广泛。实践发现,带有防跳功能的手车式断路器,与带有分合闸监视出口回路的继电保护装置配合使用时,存在分合闸信号灯混乱的现象。提出一种二次回路改进方案,增加一个中间继电器,解决了上述问题。

KYN28A-12型6kV开关柜温升发热原因及改进措施

对KYN28A-12型6kV手车式开关柜在实际工程应用中容易发生触头温升及发热故障的危害及现状进行认真分析研究后,归纳总结了造成手车式开关柜触头发热温升的主要原因,并结合多年的化工配电管理经验,提出了一些可行、实用的预防改进措施,充分发挥了开关柜的电气性能,提高了化工供电系统的供电可靠性。

KYN36-12铠装金属式封闭开关中置柜在智能化变电站的应用

介绍KYN36-12铠装金属式封闭开关柜在智能变电站的应用,提出安装后验收检查的注意事项。