Analysis of Implantation in Assisted Reproduction Through the Use of Serial Human Chorionic Gonadotropin Measurements

Purpose: Our purpose was to examine implantation of singleton pregnancies achieved following various assisted reproductive technologies (ARTs) through the appearance and rising titers of serum human chorionic gonadotropin (hCG) levels. Methods: A total of 114 singleton pregnancies resulting from in vitro fertilization and intrauterine insemination was analyzed. Patients were divided into five groups according to the type of ovarian stimulation protocol [gonadotropin stimulation with/without the use of gonadotropin-releasing hormone agonist (GnRHa), long protocol, or flare-up technique] and to the day of embryo transfer (day 2 or day 3 after oocyte retrieval). Serial serum hCG levels were measured between 10 and 25 days after fertilization and log-transformed. Linear regression analyses were performed and extrapolated to hCG = 10 mIU/ml (hCG ₁₀ ), which was used as an estimate of detectable implantation. The slopes of the regression lines were used to estimate the rising speed of hCG. Results: There were no significant differences in the days of hCG in maternal serum to reach 10 mIU/ml (implantation) or in the slopes of the regression lines for all five studied groups. Conclusions: The appearance of hCG in maternal serum was used to assess the time of clinically detectable implantation. Furthermore, because hCG production is a marker of trophoblastic activity, its serum doubling time was used as an indicator of embryo quality. Results showed that in various ART protocols with and without GnRHa, there were no significant differences in implantation time or embryo quality. Embryo development in early pregnancy follows a preprogrammed-timing schedule and depends mainly on the embryonic age of the health, successfully implanted conceptus.     

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.     

Effect of temperature in focal ischemia of rat brain studied by 31P and 1H spectroscopic imaging

³¹P, ¹H and lactate spectroscopic imaging was used to evaluate the effects of hypothermia on focal cerebral ischemia produced by middle cerebral artery occlusion. The effects on high energy phosphate metabolism, pH, lactate and NAA were investigated in 24 spontaneously hypertensive rats subjected to either permanent or transient ischemia. Under either normothermic (37.5°C) or hypothermic (32°C) conditions, with permanent 6-h occlusion, there was little difference between groups in either the NMR measurements or the volume of infarction. In animals that underwent 3 h of ischemia followed by 12 h of reperfusion, the ischemic changes in lactate, pH, NAA, and high-energy phosphate returned toward control values, and there was a protective effect of hypothermia (infarct volume of 211 ± 26 and 40 ± 14 mm³ in normothermic and hypothermic groups, respectively). Thus, hypothermia did not ameliorate the changes in lactate, pH, NAA, or high energy phosphate levels occurring during ischemia, however, during reperfusion there was an improvement in both the recovery of these metabolites and pathological outcome in hypothermic compared with normothermic animals.     

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.