精子冷冻环无保护剂玻璃化冷冻方法的初步研究

目的探讨精子冷冻环无保护剂玻璃化冷冻方法的可行性。方法正常精液标本上游处理后,进行常规冷冻和冷冻环无保护剂的玻璃化冷冻,复苏后分别从活力参数及电镜下超微结构等指标比较两种冷冻方法的效果。结果两种方法冷冻后精子存活率、活动率之间差异无显著性(48%∶48%;44.5%∶43.5%,P>0.05),但均较未冷冻的89%和88.5%明显下降(P<0.001)。超微结构亦较未冷冻时发生了一定的改变,但核结构基本保持完整。结论精子冷冻环无保护剂的玻璃化冷冻是一种简单、方便而行之有效的冷冻方法。     

Fluorimetric determination of activity and isoenzyme composition of N-acetyl-beta-D-hexosaminidase in seminal plasma of fertile men and infertile patients with secretory azoospermia.

BACKGROUND: The activity and isoenzyme composition of N-acetyl-beta-D-hexosaminidase (EC.3.2.1.52) in seminal plasma of fertile and infertile men have been evaluated. However, no data are available on the isoenzyme content in seminal plasma from patients with secretory azoospermia. METHODS: The activity and isoenzyme composition of seminal plasma from 15 normozoospermic controls and 18 patients with secretory azoospermia were determined by fluorimetric methods. 4-Methylumbelliferil-2-acetamido-2-deoxy-beta-D-glucopyranoside and 4-methylumbelliferil-2-acetamido-2-deoxy-beta-D-glucopyranoside-6-sulfate were used as fluorigenic substrates. Receiver-operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic efficiency of the assays. RESULTS: No significant difference was found in total enzyme activity between the two groups, while isoenzyme A activity was significantly lower (p=0.004) and the ratio between total enzyme activity and isoenzyme A activity was significantly higher (p=0.04) in azoospermic patients compared to controls. The diagnostic efficiency of these evaluations was low (< or =75.7%). CONCLUSIONS: Our findings show that the isoenzyme composition of N-acetyl-beta-D-hexosaminidase in seminal plasma from patients with secretory azoospermia is significantly different from controls, but this difference does not represent a useful marker of secretory azoospermia. The fluorimetric assays are simple and rapid methods for evaluating the isoenzyme composition.     

MPO和NAT2基因多态性与成人急性白血病易感性

目的研究髓过氧化物酶（MPO）和N-乙酰基转移酶2（NAT2）基因多态性与成人急性白血病易感性的关系.方法用1∶1配对病例-对照研究方法,收集成人急性白血病患者和对照各139例,应用聚合酶链-内切酶片段（PCR-RFLP）方法分析病例组和对照组MPO和NAT2的基因多态性,比较不同基因型与成人急性白血病易感性.结果 MPO-463A等位基因分布频率病例组低于对照组,MPO（G-463A）各基因型在病例组与对照组中的分布差异有统计学意义（χ^2=7.026,P〈0.05,OR=0.505,95%CI=0.325～0.847）.NAT2乙酰化表型频率在病例组与对照组的分布差异无统计学意义（χ^2=2.260,P〉0.05）;但NAT2＊5 481T等位基因和NAT2＊6 590A等位基因分布频率病例组高于对照组（P〈0.05）.结论 MPO与成人急性白血病易感性相关,携带MPO（G-463A）突变基因型（GA/AA）个体可降低白血病的发病风险;NAT2乙酰化表型可能与白血病的易感性无关,但NAT2＊5（C481T）、NAT2＊6（G590A）单核苷酸突变频率病例组明显高于对照组.     

Effect of partial proteolysis on the activation energy of beta-n-acetylhexosaminidase precursor and mature forms.

Using 3,3'-diclorophenolsulfoftaleinil N-acetyl-beta-D-glucosaminide as a substrate, the apparent activation energy of beta-N-acetylhexosaminidase (Hex) was determined in samples of plasma and urine, as well as in leukocyte and platelet lysates. Incubation with papain produced an increase in this thermodynamic variable for plasma Hex (precursor forms with high molecular mass) that would be caused by the proteolytic action of papain on the Hex A isoenzyme. However, digestion with papain did not significantly modify the activation energy of Hex in leukocyte and platelet lysates (mature enzymatic forms). In 11 healthy subjects and 28 patients with different renal diseases, no statistically significant differences were found with regard to the values obtained in cellular lysates for variations in the activation energy of urinary Hex, regardless of whether they presented normoalbuminuria, microalbuminuria or macroalbuminuria. These results support the hypothesis that even in patients with proteinuria, no significant amounts of plasma Hex precursor forms are found in urine samples, and the source of the enzyme activity is the kidney itself.     

Substituting human chorionic gonadotropin by gonadotropin-releasing hormone agonist to trigger final follicular maturation, during controlled ovarian hyperstimulation, results in less systemic inflammation.

BACKGROUND: To investigate the degree of systemic inflammation, as reflected by serum C-reactive protein (CRP) levels, associated with controlled ovarian hyperstimulation (COH) with human chorionic gonadotropin (hCG) or gonadotropin-releasing hormone (GnRH) agonist for the induction of final follicular maturation. DESIGN: Prospective, observational study. SETTING: An in vitro fertilization (IVF) unit of an academic medical center. PATIENTS: Twenty-four women undergoing COH and IVF with the flexible GnRH antagonist protocol were prospectively assigned to receive hCG or GnRH agonist for the induction of final follicular maturation. METHODS: Blood was drawn three times during COH for measurement of sex-steroid and CRP levels: the day on which adequate suppression was obtained (Day-0); the day of or prior to administration of hCG (Day-hCG); and (3) the day of ovum pick-up (Day-OPU). Levels were compared among the three time points in the two groups. RESULTS: No between-group differences were observed in terms of patient age, gonadotropin dosage, duration of stimulation or number of oocytes retrieved. Serum CRP levels were significantly higher on Day-OPU than on Day-hCG and Day-0, but the difference was significant only in the hCG group (p<0.03 for both). The percentage change in CRP levels after hCG administration (Day-OPU vs. Day-hCG) (96%) was higher than that after GnRH administration (23%). CONCLUSION: Administration of GnRH agonist in patients undergoing COH for IVF yields a lesser degree of systemic inflammation, as reflected by CRP levels, than hCG.     

Plasma levels of neuropeptides in Alzheimer's disease.

BACKGROUND: In the central nervous system, several neuropeptides are believed to be involved in the pathophysiology of Alzheimer's disease (AD). Indeed, previous studies have documented that glucagon-like peptide 1 (GLP-1) possesses neurotropic properties and can reduce amyloid-beta peptide levels in the brain in vivo. Moreover, the concentrations of neuropeptide Y (NPY) seem to be altered in the cerebrospinal fluid of patients with AD and in subjects with major depression. Finally, among the modifications induced by aging, a dysregulation of the ghrelin-growth hormone (GH) system has been reported. METHODS: We investigated the plasma concentrations of these neuropeptides in 14 subjects with AD. Data obtained from these patients were compared with data from an age- and weight-matched healthy group. RESULTS: No significant differences were found between the two groups in relation to plasma levels of GLP-1, NPY, ghrelin and GH. Peripheral NPY concentrations were positively correlated with ghrelin levels in both groups, and with plasma GLP-1 concentration only in controls. CONCLUSION: On the basis of our results, peripheral levels of these neuropeptides seem not to serve as biochemical markers of AD.     

Gonadotropin-releasing hormone antagonists increase follicular fluid insulin-like growth factor-I and vascular endothelial growth factor during ovarian stimulation cycles.

The aim of the present study was to investigate the effect of gonadotropin-releasing hormone (GnRH) antagonists (GnRH-ant) on follicular fluid (FF) insulin-like growth factor-I (IGF-I) and FF vascular endothelial growth factor (VEGF) levels. Sixty women undergoing assisted reproduction were randomized and assigned to two different GnRH analog regimens: GnRH agonist (GnRH-a) and GnRH-ant. FF VEGF and FF IGF-I concentrations were significantly increased in the patients treated with GnRH-ant (p < 0.001). In the same patients we observed a statistically significant reduction in serum luteinizing hormone (LH) and estradiol (E2) levels (p < 0.001 and p < 0.05, respectively), FF E2 and FF androstenedione levels (p < 0.05 and p < 0.001, respectively), as well as a reduction in the number of pregnancies although this was not statistically significant. In the GnRH-ant group, FF VEGF levels were positively correlated with FF IGF-I levels, and both were negatively correlated with serum LH levels. The increase in FF IGF-I and FF VEGF levels in women treated with GnRH-ant could be explained by a deleterious follicular environment in response to profound suppression of LH and E2 levels.     

Indices of surgical site infection risk and prediction of other adverse outcomes during hospitalization.

OBJECTIVE: To assess which adverse postsurgical outcomes are best predicted by the Study on the Efficacy of Nosocomial Infection Control (SENIC) index and the National Nosocomial Infection Surveillance system (NNIS) index. DESIGN: Prospective cohort study. SETTING: The service of general surgery at a tertiary care hospital. PATIENTS: A consecutive series of patients hospitalized for more than 1 day (n=2,989). RESULTS: The outcome best predicted by the SENIC and NNIS indices was assessed by estimating the area under the receiver operating characteristic (ROC) curve. The areas under the ROC curves for nosocomial infection and in-hospital death were higher for the NNIS index than they were for the SENIC index (P<.05). The NNIS index predicted in-hospital death better than it predicted surgical site infection (area under the ROC curve+/-SE, 0.836+/-0.022 vs 0.689+/-0.017; P=.001). CONCLUSIONS: The NNIS index is superior to the SENIC index for all adverse postsurgical outcomes. Its ability to predict in-hospital mortality is clearly better than its ability to predict surgical site infection.