Immunology

A selection of interesting papers that were published in the two months before our press date in major journals most likely to report significant results in immunology.     

白细胞介素—2新的功能位点及其中枢镇痛作用

白细胞介素－２（ＩＬ－２）不仅是重要的免疫调节因子，而且还具有重要的中枢调节作用。本实验以钾离子透入引起大鼠甩尾反应为指标，发现侧脑室注射ＩＬ—２能显著提高动物痛阈，并能被纳洛酮所阻断，表示ＩＬ－２的中枢镇痛作用可能与阿片受体有关。利用基因定位突变技术获得的无免疫活性ＩＬ－２实查体仍具有中枢镇痛作用，表明ＩＬ—２分子上发挥镇痛和免疫调节作用的功能位点是相互独立的。纳洛酮能够阻断ＩＬ—２的中枢镇痛作用，而不能影响ＩＬ—２增殖ＣＴＬＬ－２细胞的作用，提示ＩＬ－２发挥镇痛和免疫调节作用可能通过不同的受体途径。ＩＬ－２分子中第４５位Ｔｙｒ残基突变为Ｖａｌ后，虽仍保留了免疫活性，但丧失了镇痛功能，表示４５位Ｔｙｒ残基是ＩＬ—２发挥中枢镇痛功能的关键残基之一。我们推测ＩＬ—２的镇痛功能位点可能在ＩＬ—２分子中第４５位Ｔｙｒ残基附近区域。     

Detection of mutations in the p53 gene in human head and neck carcinomas by single strand conformation polymorphism analysis.

Using the polymerase chain reaction (PCR)-based single strand conformation polymorphism (SSCP) analysis, we have examined the highly conserved regions of the p53 gene in 58 biopsy samples of head and neck tumors. Mutations were found in 13/58 (23%) tumor specimens, but not in 6 normal tissues. Ten of 13 mutations were due to single base changes and the remaining 3 were 1- or 8-base deletion mutants. These mutations were clustered in exons 5 and 7 and resulted in amino acid changes. Our results seem to indicate that mutations in the p53 gene contribute to a significant number of cases of the head and neck tumors including 20% of nasopharyngeal carcinoma biopsies. The relationship of Epstein-Barr virus or human papillomavirus and p53 gene mutations in this group of cancers was also analyzed and discussed.     

应用激光技术治疗痔—附1376例报告

本文较详细地介绍了应用激光技术即用CO_2及Nd:YAG激光手术刀治疗各种类型痔的临床观察。我院自1988年应用CO_2及Nd,YAG(以下简称激光手术刀)的技术治疗各种痔1376例均取得满意的治疗效果,治愈率达100％,并对有关问题进行探讨。     

脑血管病患者血清IgE型免疫复合物的检测

本文用胶固素酶联免疫吸附试验检测了１６例缺血性脑血管病（ＩＣＤ）患者，１４例出血性脑血管病（ＨＣＤ）患者和２０例健康正常人的血清ＩｇＥ型循环免疫复合物（ＣＩＤ）水平。结果显示ＩＣＤ组和ＨＣＤ组ＩｇＥ－ＣＩＣ水平明显高于正常组（分别为Ｐ＜０．００１和Ｐ＜０．０５）。ＩＣＤ组与ＨＣＤ组间没有显著差异（Ｐ＞０．０２）。提示脑血管病的发生与ＩｇＥ－ＣＩＣ的形成有关。     

Structure-activity relationships for inhibition of papain by peptide Michael acceptors.

Two series of peptidyl Michael acceptors, N-Ac-L-Phe-NHCH2CH = CH-E with different electron withdrawing groups (E = CO2CH3, 1a; SO2CH3, 1b; CO2H, 1c; CN, 1d; CONH2, 1e; and C6H4-p-NO2, 1f) and R-NHCH2CH = CHCOOCH3 with different recognition and binding groups (R = N-Ac-D-Phe, 2a; N-Ac-L-Leu, 3a; N-Ac-L-Met, 4a; PhCH2CH2CO, 5a; PhCO, 6a), were synthesized and evaluated as inactivators against papain. It was found that the inhibition of papain by peptidyl Michael acceptors is a general phenomenon and that the intrinsic chemical reactivity of the E group in the Michael acceptors has a direct effect on the kinetics of the inactivation process as reflected in k2/Ki. At pH 6.2, the reactivity of papain toward the Michael acceptors is about 283,000-fold higher than the reactivity of the model thiol 3-mercaptopropionate. This large increase in reactivity is attributable to at least 2 factors; one is the low apparent pKa of Cys-25 of papain, and the other is the recruitment of catalytic power by specific enzyme-substrate interactions. The unexpectedly high reactivity of 1c (E = COOH) was rationalized by proposing a direct interaction of the acid group with His-159 in the active site of papain. The unexpected inactivity of 1f (E = C6H4-p-NO2) as a Michael acceptor and its very powerful competitive inhibition of papain were rationalized by molecular graphics which showed the nitrophenyl moiety rotated out of conjugation with the olefin and interacting instead with the hydrophobic S1' region of papain. A plot of log (k2/Ki) for 1a-6a vs log (kcat/Km) for analogous R-Gly-p-NA substrates was linear (r = 0.98) with slope of 0.83, suggesting that binding energy from specific enzyme-ligand interactions can be used to drive the self-inactivation reaction to almost the same extent as it is used to drive catalysis.     

Coronary permeability and left ventricular function following thrombolytic therapy

We study 40 patients, 55 +/- 7 years old with acute myocardial infarction treated early by thrombolytic therapy (20 STK and 20 rt-PA). All patients were angiographically studied in the following conditions: 1) baseline, before initiating therapy. 2) Three hours after treatment. 3) Twenty four hours later. 4) Before discharge. The infarct related artery was patent 24 hours after treatment in 31 patients (78%); five of them were patent before treatment, and we observed an early reperfusion in 20 patients (57%) and late reperfusion in 6 patients (17%). The number of patients with angiographic evidence of intraluminal thrombus decreased progressively through conditions while the grade TIMI of coronary perfusion increased in the absence of reocclusion. Final regional wall motion of infarct related myocardial zones and their degree of recovery were significantly higher in recanalized patients, as compared with non-reperfused patients. Similarly, left ventricular functional recovery was higher in patients with antegrade of collateral flow to the infarct area, as compared with totally occluded patients.     

儿童阻塞性睡眠呼吸暂停低通气综合征的治疗

目的探讨儿童阻塞性睡眠呼吸暂停低通气综合征(obstructive sleep apnea hypopnea syndrome，OSAHS)患儿的治疗方法和疗效观察。方法经多道睡眠监测(polysomnography，PSG)确诊的4～12岁OSAHS患儿59例：扁桃体切除和(或)经口内镜(内窥镜，下同)引导下腺样体刮除54例；选择长期正压通气治疗(continue positive airway pressure，CPAP)2例；保守治疗3例。采用儿童OSAHS生活质量调查表(quality of life for children with obstructive sleep apnea 18 items，OSA-18)对患儿进行治疗前后的随访。结果围手术期无术后出血、急性呼吸道梗阻发生。随访12～18个月，手术患儿无鼻咽闭锁、咽鼓管功能障碍、腺样体残留等并发症；OSA-18调查评分显示：治疗后76．3％(45例)的患儿生活质量总体指标，88．1％(52例)的患儿睡眠呼吸障碍，67．8％(40例)的患儿身体症状得到显著改善。长期CPAP治疗的有效治疗压力在5．6～7．8cm H2O左右。3例保守治疗者略有改善。结论手术切除引起上气道阻塞的肥大的扁桃体和(或)腺样体是儿童OSAHS有效的治疗手段之一，纤维鼻咽镜检查、头颅侧位X线摄片有助于手术适应证的确定。经口内镜引导下腺样体刮除术具有直视下操作，视野清晰，切除彻底，可避免损伤周围重要结构的特点。