胸液胆固醇对胸膜腔积液渗漏性的鉴别诊断价值

目的探讨胸液胆固醇浓度（Pch）及胸液与血清中胆固醇浓度（Sch）的比值（P／Sch）对胸膜腔积液渗漏性的鉴别诊断价值。方法检测154例胸腔积液患者Pch、Sch、胸液乳酸脱氢酶（PLDH）、血清乳酸脱氢酶（SLDH）、胸液蛋白质（Pprot）、血清蛋白质（Sprot）；并计算出P／Sch、胸液与血清蛋白比值（P／Sprot）、胸液与血清乳酸脱氢酶比值（P／SLDH）。分别研究Pch和P／Sch对胸膜腔积液渗漏性诊断的敏感性和特异性，并与Light标准等进行比较。结果Pch和P／Sch对胸膜腔积液渗漏性诊断的敏感性分别为91.5％和96.1％，特异性分别为87.5％和95.8％。P／Sch对胸膜腔积液渗漏性诊断的敏感性高于PLDH和P／Sprot(P＜0.05)，特性性高于Light标准和P／Sprot（P＜0.05）。结论Pch及P／Sch对胸膜腔积液的渗漏性具有很高的鉴别诊断价值。     

胸腔积液胆固醇对胸腔积液性质的判定价值

目的：通过测定胸腔积液（胸水）中胆固醇（Pch）以判定胸水的性质。方法：回顾性研究148例诊断明确且为单一因素所致胸水患者的Pch、胸水乳酸脱氢酶活性（PLDH）、胸水蛋白（Pprot）、血清蛋白（Sprot）值及胸水与血清总蛋白的比值（P/Sprot）,按病因分为漏出液组、结核性胸膜炎（TB）组、炎症组和恶性胸水组,比较各组Pch、PLDH、Pprot、P/Sprot值的差异,及Pch、PLDH、P/Sprot诊断胸水渗漏性的价值。结果：漏出液组Pch、PLDH、Pprot、P/Sprot低于渗出液各组相应值（P<0.001）。取Pch 1.25 mmol/L作为诊断渗、漏出液的临界值,Pch、PLDH、P/Sprot、Pch联合PLDH对胸水渗出液诊断的敏感性分别为92.1.%、71.9%、86.8%和97.4%,特异性分别为100%、100%、97%和100%,总有效率分别为93.9%、78.4%、90.5%、98.0%。结论：Pch是胸水中相对稳定的参数,其检测简单易行,对胸水渗漏性具有较高的诊断价值,可为Light标准的一个重要补充。     

腺苷脱氨酶检测在胸腔积液诊断中的临床价值

目的探讨腺苷脱氨酶（ADA）活性测定在胸腔积液诊断和抗结核疗效观察中的临床价值。方法对临床明确诊断的120例住院患者胸水和血清标本用氨显色法在日立7180生化仪测定其ADA活性值。结果结核性胸腔积液组ADA活性为（54．91±11．24）U／L,明显高于癌性胸腔积液组（19．25±9．73）U／L及炎性胸腔积液组（16．49±7．61）U／L,差异有统计学意义（P〈0．05）。ADA诊断结核性胸腔积液的敏感性为93．2％（41／44）,特异性为97．6％（81／83）。结核性胸腔积液患者ADA活性治疗前（54．91±11．24）U／L与治疗后（9．12±6．24）U／L比较,差异有统计学意义（P〈0．05）。结论ADA可作为结核核性与非结核胸腔积液的重要鉴别指标之一及结核性胸膜炎患者病情进展监测的良好指标。     

腺苷脱氨酶与癌胚抗原检测在胸腔积液诊断中的价值

目的分析腺苷脱氨酶（ADA）与癌胚抗原（CEA）检测在胸腔积液诊断和鉴别诊断中的应用价值。方法对46例自2008年9月～2009年6月我院经治有胸腔积液症状的患者检测胸腔积液和血清ADA、CEA水平,对不同疾病组结果分析比较。结果结核性胸腔积液组ADA为（43.00&#177;13.82）U/L,CEA的含量为（1.25&#177;1.22）μg/L;恶性胸腔积液组A-DA为（17.57&#177;6.20）U/L,CEA为（293.74&#177;197.50）μg/L。结核性胸腔积液组ADA含量较恶性胸腔积液组明显增高（P〈0.01）,恶性胸腔积液组CEA含量较结核性胸腔积液组明显增高（P〈0.01）。胸腔积液ADA（pADA）/血清ADA（sADA）及胸腔积液CEA（pCEA）/血清CEA（sCEA）比值,结核性胸腔积液组（2.69&#177;0.83、1.05&#177;0.89）与恶性胸腔积液组（0.87&#177;0.22、9.47&#177;5.91）相比有显著性差异（P〈0.01）,pADA及pCEA判断结核性胸腔积液的临界值分别为：39U/L、pCEA〈5μg/L,恶性胸腔积液的敏感性为95%、特异性为99.8%。结论胸腔积液腺苷脱氨酶与癌胚抗原测定对结核性胸腔积液和恶性胸腔积液的诊断具有重要价值。     

腺苷脱氨酶及其同工酶对结核性腹水的诊断价值

目的 研究联合检测腺苷脱氨酶（ADA）及其同工酶对结核性腹水的诊断和鉴别诊断价值。方法 建立ADA同工酶的分离检测方法。同步检测10例结核性腹水和57例非结核性腹水患者的腹水ADA总活性和同工酶,分析结核和非结核性腹水ADA总活性和同工酶谱型的差异。结果 结核性腹水中ADA活性明显高于非结核性腹水,以30U／L为界值诊断结核的敏感性和特异性分别为80％和100％。ADA同工酶Ⅱ（ADAⅡ）仅结核性腹水为阳性,诊断结核的敏感性为90％。ADA总活性和同工酶对结核性腹水具有互补诊断价值。结论 ADA总活性及其同工酶对结核性腹水均有重要诊断价值,二者联合检测可进一步提高对结核性腹水的诊断水平。     

Specificity of adenosine deaminase inhibitors

The specificity of the potent adenosine deaminase inhibitors deoxycoformycin (covidarabine), coformycin and erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA), has been assessed in Ehrlich ascites tumor cells in vitro and in cultured mouse lymphoma L5178Y cells. EHNA is both less potent an inhibitor of adenosine deaminase than deoxycoformycin, and is less specific. High concentrations of deoxycoformycin and EHNA inhibit all pathways of purine ribonucleotide synthesis, and inhibit the conversion of inosinate to adenine and guanine nucleotides. These drugs also inhibit purified adenylate deaminase, but inhibition of this enzyme in intact cells can only be detected at high rates of deamination of adenylate. Deoxycoformycin potentiates the toxicity of adenine against cultured cells.     

支气管肺泡灌洗液腺苷脱氨酶对肺结核诊断的临床价值探讨

目的：探讨支气管肺泡灌洗液（BALF）中腺苷脱氨酶（ADA）浓度对肺结核诊断的临床价值。方法74例疑似肺结核患者,在行纤维支气管镜检查时留取BALF,采用酶法测定BALF其中的ADA浓度。74例患者根据最终确诊结果分为两组：结核组33例,非结核组41例。结果结核组BALF中ADA平均浓度为（20±3）U/L,非结核组为（4±2）U/L,前者明显高于后者,两者差异有统计学意义（P〈0.01）。结论检测BALF中ADA浓度对肺结核具有很高的诊断和鉴别诊断价值。     

Primary structure of bovine adenosine deaminase

Derivatized bovine adenosine deaminase is used in enzyme replacement therapy and as an adjunct to gene therapy against severe combined immunodeficiency syndrome. Although a gene sequence is known for human adenosine deaminase, the structure of the bovine enzyme has not been characterized. Structure studies using mass spectrometry are reported here that evaluate sequence, processing, post-translational modifications and the extent of homology between the human protein and its therapeutic surrogate.     

Activity of ectonucleotidases and adenosine deaminase in rats exposed to cigarette smoke

Cigarette smoke is a complex mixture of various toxic substances that are capable of initiating oxidative damage and promoting blood platelet alterations. In this study, we investigated the activities of the ectoenzymes NTPDase (ectonucleoside triphosphate diphosphohydrolase, CD39) and 5′-nucleotidase (CD73) in platelets as well as adenosine deaminase (ADA) in the plasma of rats exposed to aged and diluted sidestream smoke during 4 weeks. The rats were divided into two groups: I (control) and II (exposed to smoke). After the exposure period, blood was collected and the platelets and plasma were separated for enzymatic assay. The results demonstrated that NTPDase (with ATP as substrate) and 5′-nucleotidase (AMP as substrate) activities were significantly higher in group II (p?<?0.05) as compared to group I, while no significant difference was observed for NTPDase with ADP as substrate. The ADA activity was significantly reduced in group II (p?<?0.05) as compared with group I. Platelet aggregation was significantly increased in group II (p?<?0.05) as compared with group I. We suggest that these alterations in the activity of enzymes from the purinergic system are associated with an increase in platelet aggregation. However, our study has demonstrated that the organism tries to compensate for this enhanced aggregation by increasing hydrolysis of AMP and reducing hydrolysis of adenosine, a potent inhibitor of aggregation and an important modulator of vascular tone.     

Study on the inhibition of adenosine deaminase

4(R)-(1-Hydroxyethyl)-5-methyl-1-beta-D-ribofuranosylimidazole (10), which contains only the asymmetric alcohol center of the diazepinol ring of the adenosine deaminase inhibitor coformycin (12), is a much less potent inhibitor of the enzyme but still binds to the enzyme about as tightly as the normal substrate.     

Degradation of adenosine by extracellular adenosine deaminase in the rat duodenum

1. Extracellular degradation of adenosine by adenosine deaminase was studied in the rat duodenum using high performance liquid chromatography (HPLC) and pharmacological techniques. 2. Relaxant responses to adenosine (1-10 microM) were potentiated in a concentration-dependent manner by erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA) and deoxycoformycin, both of which are inhibitors of adenosine deaminase. 3. Breakdown of adenosine, determined by HPLC, due to incubation with segments of rat duodenum was inhibited by both EHNA and deoxycoformycin. Cytosolic sources of adenosine deaminase were excluded. 4. Relaxant responses to adenosine were also potentiated by the adenosine transport inhibitor dilazep, which did not inhibit adenosine deaminase activity. 5. The extracellular adenosine deaminase activity (4 units/g tissue) was high compared with activity previously determined in other organs.     

Antinociceptive and anti-inflammatory properties of an adenosine kinase inhibitor and an adenosine deaminase inhibitor

Spinal administration of an adenosine kinase inhibitor, alone or in combination with an adenosine deaminase inhibitor, produces antinociception in inflammatory pain tests. In the present study, we examined the antinociceptive and anti-inflammatory effects produced by the peripheral (intraplantar) administration of 5'-amino-5'-deoxyadenosine (an adenosine kinase inhibitor), 2'-deoxycoformycin (an adenosine deaminase inhibitor), and combinations of both agents in the carrageenan-induced thermal hyperalgesia and paw oedema model in the rat. When injected in the ipsilateral paw immediately prior to carrageenan injection, both agents produced antinociception only at the highest dose (1 micromol), whereas a reduction in paw swelling was evident at a lower dose (300 nmol). Significant augmentation in both the antinociceptive and anti-inflammatory effects was seen when 5'-amino-5'-deoxyadenosine and 2'-deoxycoformycin were co-administered in equimolar doses at all dose levels. Both effects were mediated via activation of adenosine receptors, as indicated by blockade by an adenosine receptor antagonist. When administered into the contralateral paw, 1 micromol 5'-amino-5'-deoxyadenosine+1 micromol 2'-deoxycoformycin produced prominent antinociception, indicating a systemic drug activity. There was only a modest reduction in paw oedema in the carrageenan-injected (ipsilateral) paw, suggesting that much of this activity was locally mediated. Reversal of systemic effects on thermal thresholds by an intrathecal adenosine receptor antagonist implicates a spinal site of action in this instance. An ipsilateral administration of 1 micromol 5'-amino-5'-deoxyadenosine, but not 1 micromol 2'-deoxycoformycin, reduced carrageenan-induced c-Fos expression in the spinal dorsal horn, and this was further reduced by the peripheral co-injection of the two agents. These results provide evidence for a predominantly spinal antinociceptive effect and a predominantly peripheral anti-inflammatory effect produced by inhibitors of adenosine kinase and adenosine deaminase.     

Modulating effect of adenosine deaminase on function of adenosine A1 receptors

AIM: To study the modulating effect of adenosine deaminase (ADA) on the adenosine A1 receptor (A1R) in HEK293 cells stably expressing the human A1R. METHODS: cDNA was amplified by RT-PCR using total RNA from human embryo brain tissue as the template. The PCR products were subcloned into the plasmid pcDNA3 and cloned into the plasmid pcDNA3.1. The cloned A1R cDNA was sequenced and stably expressed in HEK293 cells. The modulating effect of adenosine deaminase on A1R was studied by using [3H]DPCPX binding assay and an intracellular calcium assay. RESULTS: HEK293 cells stably expressing human A1R were obtained. Saturation studies showed that the K(D) value and B(max) value of [3H]DPCPX were 1.6+/-0.2 nmol/L and 1.819+/-0.215 nmol/g of protein respectively, in the absence of ecto-ADA respectively, and 1.3+/-0.2 nmol/L and 1.992+/-0.130 nmol/g of protein in the presence of ecto-ADA respectively, suggesting that the K(D) value and B(max) value of [3H]DPCPX were unaffected by ecto-ADA. In the case of [3H]DPCPX competition curves obtained from intact cells or membranes, A1R agonist CCPA/[3H]DPCPX competition curve could be fitted well to a one-site model in the absence of ecto-ADA and a two-site model in the presence of ecto-ADA with a K(H) value of 0.74 (0.11+/-4.8) nmol/L (intact cells) or 1.8 (0.25+/-10) nmol/L (membrane) and a K(L) value of 0.94 (0.62+/-1.41) micromol/L (intact cells) or 0.77 (0.29+/-0.99) micromol/L (membrane). The K(L) value is not significantly different from the IC50 value of 0.84(0.57+/-1.23) micromol/L (intact cells) or 0.84 (0.63+/-1.12) micromol/L (membrane) obtained in the absence of ecto-ADA. Similar results were obtained from the CPA/[3H]DPCPX competition curve in the absence or presence of ecto-ADA on intact cells or membranes. Intracellular calcium assay demonstrated that the EC50 value of CPA were 10 (5+/-29) nmol/L and 94 (38+/-229) nmol/L in the presence or absence of ecto-ADA, respectively. CONCLUSION: A1R stably expressed in the HEK293 cells display a low affinity for agonists in the absence of ADA and high and low affinities for agonists in the presence of ADA. The presence of ADA may promote the signaling through the adenosine A1 receptor in HEK293 cells.     

Inhibition of adenosine deaminase by azapurine ribonucleosides.

We have synthesized several 8-azapurine nucleosides as inhibitors of adenosine deaminase. The presence of a nitrogen on the imidazole ring decreased the Ki value for nebularine by 100-fold but did not lower the Ki value for coformycin. Evaluation of these compounds in a MOLT-4 growth assay revealed that 2-azacoformycin was as effective as 2'-deoxycoformycin in potentiating growth inhibition by 2'-deoxyadenosine. The azapurine nucleosides merit further study as antitumor agents.     

胸腔积液中腺苷脱氨酶的临床检测意义分析

目的探讨胸腔积液中腺苷脱氨酶的临床检测意义。方法选择本院结核性胸腔积液患者共35例,作为结核组：同时选择本院肿瘤性胸腔积液患者共30例,作为肿瘤组。取两组患者胸腔积液,测定腺苷脱氨酶活性。结果结核组胸腔积液中腺苷脱氨酶活性显著高于肿瘤组,差异有统计学意义（P〈0．05）;结核组胸腔积液中腺苷脱氨酶阳性检出率显著高于肿瘤组,差异有统计学意义（P〈0．05）。结论胸腔积液患者中行胸腔积液腺苷脱氨酶活性检测有助于结核性胸腔积液和肿瘤性胸腔积液鉴别诊断,检测意义重要,值得借鉴。     

Properties of adenosine deaminase from cultured endothelial cells]

Cultivated calf aortic endothelial cells (line BZEz-7) show a remarkable activity of adenosine deaminase with a Vmax of 1.8 pmol/cell.min-1. The kM is about 160 mumol. The localization of the enzyme was determined intracellularly. The ADA is only of minor importance for the regulation of the adenosine uptake of endothelial cells. Their significance for the control of the immune system is discussed.