Ascorbic Acid in Human Seminal Plasma: Determination and Its Relationship to Sperm Quality

The objective of the present study was to assess the ascorbic acid (AA) levels in seminal plasma of the fertile and infertile men and to investigate its relationship with sperm count, motility and normal morphology. Semen samples were provided by fertile [smoker (n = 25), nonsmoker (n = 21)] and infertile men [smoker (n = 23), nonsmoker (n = 32)]. A simplified method of reverse phase high performance liquid chromatography (RP-HPLC) procedure using UV detection was applied for the determination of seminal AA. Fertile subjects, smoker or not, demonstrated significantly higher seminal AA levels than any infertile group (p<0.01). Nonsmokers had high, but no significant, mean AA levels in their seminal plasma compared with smokers. Seminal AA in fertile and infertile (smokers or nonsmokers) males correlated significantly with the percentage of spermatozoa with normal morphology (p<0.01). Seminal AA decreased significantly in infertile men. Decrease of seminal plasma AA is a risk factor for low normal morphology of spermatozoa and idiopathic male infertility. Measurement of seminal AA in the seminal plasma of males with a history of subfertility or idiopathic infertility is necessary and can be helpful in fertility assessment.     

Malondialdehyde levels in sperm and seminal plasma of asthenozoospermic and its relationship with semen parameters

BACKGROUND: Toxic lipid peroxides are known to cause various impairments of sperm cells and may play a major role in the etiology of male infertility. We determined the level of lipid peroxidation as indicated by malondialdehyde (MDA) in the spermatozoa and seminal plasma of asthenozoospermic and normozoospermic males. METHODS: MDA of spermatozoa and seminal plasma was determined in 35 asthenozoospermic and 15 normozoospermic men by spectrofluorometry. Semen analysis was done according to the WHO standard. RESULTS: MDA concentration in the spermatozoa of asthenozoospermic was significantly higher than in normozoospermic males (0.14+/-0.059 and 0.09+/-0.04 nmol/10 x 10(6) spermatozoa respectively). The mean+/-S.D. MDA value in the seminal plasma of asthenozoospermic and normozoospermic were 1.35+/-0.42 and 1.2+/-0.3 nmol/ml seminal plasma respectively. CONCLUSIONS: Lipid peroxidation has a deleterious effect on the semen quality and MDA is an index of lipid peroxidation which may be a diagnostic tool for the analysis of infertility in the asthenozoospermic patients.     

Determination of serum amyloid P component in seminal plasma and correlations with serum hormone levels in young, healthy men

Serum amyloid P component (SAP) belongs to the pentraxin family of proteins. SAP is evolutionary conserved, and involved in amyloidosis, innate immunity, inflammation, and apoptosis. We have previously described SAP in the male reproductive tract, where it occurs in seminal fluid, on spermatozoa, and in epididymal, seminal vesicle, and prostate tissue. In the present investigation, our aim was to characterize SAP in male reproduction. In short, we developed and evaluated an immunoassay, analysed the concentration of SAP in seminal plasma and serum in samples from healthy men (N = 203), and studied hormonal regulation. SAP in seminal plasma showed a positively skewed distribution and a median concentration of 1.01 mg/L (inter quartile range [IQR] 0.56-1.65 mg/L). SAP in serum had a Gaussian distribution and a median concentration of 40.5 mg/L (IQR 34.2-49.2 mg/L). Furthermore, SAP concentrations in seminal plasma were not correlated with serum concentrations of SAP, testosterone, sex hormone-binding globulin (SHBG), the testosterone/SHBG ratio, inhibin B, or estradiol. Only a weak negative correlation was found between seminal plasma SAP and serum levels of follicle-stimulating hormone (FSH) (Spearman's rho -0.159; p = 0.023) and luteinizing hormone (LH) (Spearman's rho -0.162; p = 0.021). In conclusion, all men investigated had measurable SAP levels in seminal plasma and in serum. SAP concentrations were 40 times lower in seminal fluid than in serum, and there was no correlation between those two variables. It seems that hormonal regulation is not the major pathway regulating seminal plasma SAP, and seminal plasma SAP and serum SAP are not co-regulated.     

ABO blood group antigens of human spermatozoa

ABO blood group antigens on the membrane of human spermatozoa were investigated with the peroxidase-labelled antibody test. Spermatozoa from O secretor were incubated with saliva or seminal plasma of A and B secretors, but the specific peroxidase staining was negative. This result indicates that blood group antigens on human spermatozoa originate from spermatozoon itself, but not from seminal plasma.     

Superoxide dismutase activities of spermatozoa and seminal plasma are not correlated with male infertility

Abnormal reactive oxygen species (ROS) production is associated with defective sperm function. Superoxide dismutase (SOD) is related with the scavenging of seminal ROS. We aimed to determine the effect of SOD activities of spermatozoa and seminal plasma on sperm quality. Semen samples from infertile couples who consented to the analyses were divided into two groups: 1) normospermia (n = 20); and 2) oligoasthenozoospermia (n = 31). The SOD activities of the spermatozoa and seminal plasma were measured by determining the inhibition of pyrogallol autoxidation. The SOD activities of spermatozoa and seminal plasma in both groups were compared. The relationships between the SOD activities and the sperm qualities were determined. We noted that SOD activities of sperm/seminal plasma in both groups were nonsignificantly different (group 1 vs. 2 = 0.77 +/- 0.33/0.84 +/- 0.40 U/mg protein for sperm, and 0.66 +/- and 0.36/0.83 +/- 0.47 U/ml for seminal plasma). SOD activities of sperm/seminal plasma were positively but nonsignificantly correlated with the sperm motility (SOD of sperm = 0.0008 x motility + 0.67; SOD of seminal plasma = 0.0006 x motility + 0.81) and concentration (SOD of sperm = 0.0006 x concentration + 0.67; SOD of seminal plasma = 0.0021 x concentration + 0.73). We concluded that SOD activities of sperm and seminal plasma were nonsignificantly correlated with the seminal quality. It appears that the SOD survey is not a useful tool for determining sperm fertilization potential.     

不育症患者精浆弹性蛋白酶检测的临床意义

目的研究男性不育患者精浆中弹性蛋白酶的含量变化和临床意义,探讨其在诊断无症状性生殖道炎症中的作用;以及其对精子DNA完整性的保护作用的研究。方法收集140例不育症门诊患者的精浆标本（实验组）;按WHO标准80例诊断为弱精子症;60例为精液常数正常的不育症男性。所有患者都没有生殖道感染的症状,3个月前无抗菌治疗。采用ELISA双抗体夹心酶联免疫吸附法检测患者精浆弹性蛋白酶水平,20例生育男性作对照。采用硝酸还原酶法检测精浆一氧化氮水平;采用吖啶橙染色,计算单链DNA精子比例,对精子DNA完整性进行评估。结果1、140例不育男性患者（实验组）精浆中的弹性蛋白酶、一氧化氮（NO）浓度、精子单链DNA百分比明显高于生育男性（对照组）（P〈0．001）。2、弹性蛋白酶浓度与患者年龄（r=0．255,P〈0．01）及精液中白细胞数（r=0．569,P〈0．01）有正相关关系。3、弹性蛋白酶浓度与精液量（r=0．537,P〈0．01）及精子单链DNA比率（r=0．436,P〈0．01）呈负相关关系;与精浆NO浓度无相关关系（r=0．083,P=0．331）。结论精浆中粒细胞弹性蛋白酶检测对诊断无症状性生殖道炎症是一种可靠的筛查试验,另外,弹性蛋白酶可能对精子DNA有保护性作用。     

Protein C inhibitor in human body fluids. Seminal plasma is rich in inhibitor antigen deriving from cells throughout the male reproductive system.

An assay was developed for the measurement of human protein C inhibitor antigen (PCI) in blood plasma and other biological fluids. Both native PCI, modified inhibitor, and complexes of inhibitor with activated protein C or plasma kallikrein could be measured with the assay. Inhibitor antigen concentrations were found to be very high in seminal plasma (greater than 200 mg/liter), more than 40 times the concentration of PCI found in blood plasma. The inhibitor in seminal plasma was unable to form complexes with activated protein C. Gel filtration and immunoblotting findings indicated that the inhibitor in seminal plasma is present in a high molecular mass complex or cleaved to its modified form. As PCI antigen was absent from seminal plasma of patients with dysfunctional seminal vesicles, the seminal vesicle glands would appear to be the major source of seminal plasma PCI, a conclusion supported by immunohistochemical demonstration of the presence of PCI epitopes in the secretory epithelium of the seminal vesicles. Specific PCI immunoreactivity was also shown to be present in the testes, the epididymis glands, and the prostate, suggesting the inhibitor to have a complex or multiple function in the male reproductive system. Conclusive evidence of a local synthesis of PCI in the four male sex glands was provided by Northern blot analysis of RNA from these organs.     

男性不育患者精子形态与精浆锌和精子顶体酶活性关系的研究

目的：研究男性不育患者精子形态与精浆锌和精子顶体酶活性关系。方法455例男性不育患者分别根据年龄和精子正常形态百分率分成5组和8组,采用 Diff-Quik 染色法、改良 PRA 法和改良 Kennedy 法分别进行精子形态、精浆锌和精子顶体酶活性的检测。结果各年龄组的正常形态精子百分率和精浆锌浓度差异无统计学意义（P ＞0．05）,精子顶体酶活性在36～50岁年龄段显著降低（P ＜0．05）,其他年龄段精子顶体酶活性差异无统计学意义（P ＞0．05）。在精子正常形态百分率不同的8组中,年龄差异无统计学意义,精浆锌总量差异无统计学意义,精子顶体酶活性随着精子正常形态百分率降低而降低（r ＝0．93,P ＜0．01）。结论精子正常形态百分率不受年龄和精浆锌的影响,与精子顶体酶活性呈正相关。     

Polyamines and polyamine-metabolizing enzyme activities in human semen

The content of polyamines putrescine, spermidine and spermine as well as the activities of some polyamine-metabolizing enzymes have been analyzed from normal and pathological human semen samples. Seminal fluid from semen samples showing no apparent abnormalities in semen analyses contained about 0.2 mM of putrescine, 0.1 mM of spermidine and 3 mM of spermine. Seminal plasma was found to be an exceptionally rich source of diamine oxidase activity (EC 1.4.3.6). In addition, polyamine-synthesizing enzyme activities, S-adenosylmethionine decarboxylase and spermidine synthase, were invariably found in seminal plasma. Spermatozoa contained very low or undetectable activities of 5-adenosylmethionine decarboxylase and spermidine synthase; however, a definitive diamine oxidase activity was found also in the cellular component of the semen.The activity of diamine oxidase, and especially that of spermidine synthase, was relatively high in semen samples having low sperm density (less than 20 × 10⁶ spermatozoa per ml). With increasing number of spermatozoa there was a slight decrease in both activities, but as the sperm count exceeded 100 × 10⁶ per ml the activity of diamine oxidase and spermidine synthase sharply increased. The concentration of spermine in seminal plasma showed only minor changes in relation to the number of spermatozoa in semen, the changes being roughly opposite as compared to the changes of the enzyme activities. A significant negative correlation was found between the concentration of putrescine and the activity of diamine oxidase in seminal plasma.Several properties of diamine oxidase from human seminal plasma were found to be comparable to those of other mammalian diamine oxidases. Using radioactive putrescine as the substrate the enzyme activity was inhibited by addition of unlabelled histamine, cadaverine, spermidine and spermine. The enzyme was also powerfully inhibited by various carbonyl reagents and methylglyoxal bis-(guanylhydrazone).     

男性不育症患者精浆中miR-145 的表达水平及其临床意义

目的　探讨男性不育症患者精浆中miR-145 的表达水平及其临床意义。方法　招募2017 年1 月~ 2018 年9 月 男性不育症患者130 例和同期体检正常的生育男性50 例为正常对照组。采用实时荧光定量PCR 检测精浆中miR-145 的 表达水平,精液常规参数采用WLJY-9000 伟力彩色精子检测系统进行分析。应用ROC 曲线分析miR-145 对男性不育症 的诊断价值,采用Pearson 相关分析精浆中miR-145 表达水平与精液参数的相关性。结果　男性不育症组精浆中miR- 145 表达水平明显高于对照组（3.92±0.86 vs 1.16±0.35）,而男性不育症组精子浓度（70.24±28.60 vs 112.50±46.35） ×106/mL、精子存活率（38.40±7.60 vs 73.84±5.82）%、前向运动精子百分率（17.52±9.73 vs 46.20±5.30）% 及正常 精子形态百分率（2.60±1.42 vs 9.25±1.70）% 明显低于对照组,差异均有统计学意义（t=4.852~11.238,均P<0.01）。 ROC 曲线分析显示,精浆中miR-145 表达水平诊断男性不育症的曲线下面积（AUC）为0.864（95%CI:0.807~0.925）, 其最佳诊断截断值为2.15,敏感度和特异度分别为92.8% 和75.0%。相关分析显示,男性不育症患者精浆中miR-145 表 达水平与精子浓度、精子存活率、前向运动精子百分率均呈正相关（r=0.427,0.604,0.538,均P<0.01）。结论　精浆 中miR-145 表达水平在男性不育症患者中明显上调,且精子浓度、精子存活率、前向运动精子百分率呈正相关,有望 作为男性不育症的辅助诊断指标。     

Thermodynamic study of beta-N-acetylhexosaminidase enzyme heterogeneity in human seminal plasma

BACKGROUND: It has been suggested that the activity of beta-N-acetylhexosaminidase (Hex) in seminal plasma may be used as a biochemical marker of azoospermia. The purpose of our study was to evaluate this hypothesis using a thermodynamic procedure developed to determine total Hex activity and that of its isoenzymes in this biological fluid. METHODS: Using the substrate 3,3'-dichlorophenolsulphoftaleinil N-acetyl-beta-D-glucosaminide, a highly significant difference (p<0.001) is found between the activation energy of Hex A (41.5 kJ/mol) and of Hex B (72.3 kJ/mol), making it possible to determine the activity of these isoenzymes from the apparent activation energy of the total Hex in seminal plasma. RESULTS: A significant difference between the normozoospermic and azoospermic groups was only found for Hex A isoenzyme activity (p<0.05), although with considerable overlapping between the values of both groups. Significant partial correlations were found for the total Hex, Hex A and Hex B activities with the immobile spermatozoa count (p<0.01) and for total Hex and Hex B with the dead spermatozoa count (p<0.05). In turn, Hex A had a significant partial correlation with the live spermatozoa count (p<0.05); however, Hex activity in seminal plasma of acromosomal origin appears to be of little importance in quantitative terms. CONCLUSIONS: It was not possible to confirm that total Hex activity in seminal plasma, or even of its isoenzymes Hex A and Hex B, is a suitable biochemical marker of azoospermia (efficiency< or =67%). The thermodynamic procedure described may be a useful alternative for the study of the Hex enzyme heterogeneity in spermatozoa.     

精浆和血清抗苗勒管激素与精液参数的相关性研究

目的探讨精浆和血清抗苗勒管激素(AMH)水平与男性精子数量和活力的相关性。方法选取到广东省中山市博爱医院生殖门诊就诊的、因女性原因不孕的健康男性215例,检测精浆、血清AMH及精液参数(精子的密度、活率、活力及畸形率),测定血清性激素6项。分别以精浆和血清AMH为因变量,采用多重线性回归模型探讨其与精液参数和性激素水平的定量关系。结果 215例研究对象中,总精浆AMH中位数为0.47,四分位数为0.05~3.09pmol/次射精。血清AMH中位数为53.07,四分位数为32.32~72.20pmol/L。经过多重线性回归分析,在矫正年龄和体质量指数后,精浆AMH与精子总数、精液浓度、前向精子活动力、总精子活动力、血清抑制素B呈正相关(P0.05);与精子形态和其他血清性激素相关性比较,差异无统计学意义(P0.05);血清AMH与血清促卵泡激素呈负相关,与血清抑制素B呈正相关(P0.05);与精浆各参数和其他血清性激素相关性比较,差异无统计学意义(P0.05)。结论精浆AMH个体差异大,与精液浓度、精子总数、精子活力呈正相关,尚未发现血清AMH与其相关。     

Transcobalamin II in human seminal plasma.

Study of cobalamin-binding proteins revealed seminal plasma to be the most concentrated site of transcobalamin II in man. The next richest normal fluid, blood, has approximately one-tenth its concentration. Normal seminal unsaturated cobalamin-binding capacity averaged 15,030 +/- 7,290 pg/ml, of which 11,550 +/- 6,660 pg/ml was transcobalamin II. Transcobalamin II levels were markedly diminished in subjects lacking seminal vesicles (1520-1660 pg/ml), but not after vasectomy. This suggests that seminal vesicles are the chief source of this protein in semen. R binder concentration was increased in postvasectomy subjects (9,970 +/- 4,900 pg/ml vs. 2,980 +/- 1,370 pg/ml in normals) and varied in other patients. The endogenous cobalamin content of semen was only 88-699 pg/ml, and was carried largely by R binder rather than by transcobalamin II. The function of the unusually large seminal transcobalamin II pool in reproduction is unknown, but seems unlikely to be related solely to cobalamin transport needs, at least within the male reproductive tract itself.     

High-performance liquid chromatographic detection of lipid peroxidation in human seminal plasma and its application to male infertility

BACKGROUND: A simple and reliable high-performance liquid chromatographic (HPLC) method has been developed and validated for the analysis of malondialdehyde (MDA) in human seminal plasma. METHODS: After human seminal plasma is hydrolyzed, MDA is reacted with thiobarbituric acid (TBA) to form MDA(TBA)(2), a red-colored adduct with maximum absorbance at 532 nm. HPLC separation of the adduct in human seminal plasma was performed on a Lichrospher C(18) column. RESULTS: A mobile phase composed of 0.025 mol/l KH(2)PO(4) (pH 6.2)--methanol in the ratio 58:42 (v/v) was found to be the most suitable for this separation. Under the chromatographic conditions described, the MDA-TBA adduct had a retention time of approximately 4 min and good separation and detectability of MDA in human seminal plasma sample was obtained. The method proved to be linear calibration in the range of MDA from 0.10 to 2.50 micromol/l. The relative standard deviations of within- and between-assay for MDA analysis were 3.1% and 3.8%, respectively. The average recovery was 90.0-98.8% for the human seminal plasma samples. The method has been successfully applied to the study of the lipid peroxidation levels in the seminal plasma of male infertility. Semen samples were obtained from healthy volunteers and infertile males. Ejaculates were classified into studied subgroups and defined as: obstructive azoospermia, non-obstructive azoospermia, oligozoospermia, asthenozoospermia, oligoasthenozoospermia and oligoasthenoteratozoospermia. With the exception of obstructive azoospermic group, MDA concentrations of seminal plasma in control group had very significant difference with those in other infertile groups (P < 0.01). CONCLUSIONS: This indicated that lipid peroxidation could be harmful to male sperm and reproductive system, which may lead to male infertility.     

精液乳酸脱氢酶同工酶X在精索静脉曲张男性不育患者中的意义

目的测定精索静脉曲张患者精子乳酸脱氢酶同工酶X(LDH-X)的含量,探讨其在男性不育的应用价值。方法采用速率法检测男性不育组和生育组精浆、精子中的LDH-X活性并计算其比值;按照《WHO人类精液实验室手册》要求对精液进行常规分析。结果 95例精索静脉曲张不育组精浆LDH-X活性(926.3±58.3)U/L与60例生育组LDH-X活性(682.0±43.5)U/L比较差异有统计学意义(P<0.01),不育组精子LDH-X的活性(6.90±3.82)mU/106则小于生育组(21.1±9.2)mU/106(P<0.01),差异具有统计学意义。不育组、生育组精浆/全精子中LDH-X的比值比较差异具有统计学意义(P<0.05)。而两组的精液密度、活动率及精子活力差异无统计学意义(P>0.05)。结论精浆及精子LDH-X活性、比值能够反映精子的质量、生育功能以及对选择治疗方案和诊断不明原因的不育有一定指导意义。     

禁欲时间对精子参数及精浆生化指标的影响

目的 探讨禁欲时间对精子参数及精浆生化指标的影响.方法 采用精子形态检测系统下人工修正方法进行精子形态分析.采用精子质量检测系统进行精子密度、活力分析.精浆果糖含量、中性a糖苷酶、精浆锌、酸性磷酸酶等采用分光光度比色法测定.采用DTNB改进法检测精浆肉毒碱含量.前列腺特异性抗原(PSA)采用试剂盒进行检测.根据禁欲时间分为3组:G1(禁欲1～3d)组、G2(禁欲4～5d)组和G3(禁欲6d以上)组.结果G2组精子密度[(70.64±63.79)×106]显著高于G1组[(57.40±45.36)×106,P＜0.01],G3组精子密度[(77.00±65.43)×106]显著高于G1组[(57.40±45.36)×106]和G2组[(70.64±63.79)×106,P＜0.01];而G3组精子活力[(36.30±21.46)%]和形态正常精子百分率[(17.00±9.86)%]显著低于G1组[(40.47±20.60)%,(18.32±9.83)%,均P＜0.01].G3组果糖含量[(20.86±15.54)μmol/1次射精]显著低于G1组和G2组[(26.40±16.53)、(23.45±18.08)μmol/1次射精,P＜0.01,P＜0.05],而G3组精浆中性a-糖苷酶[(47.14±33.61)mU/1次射精]、肉毒碱[(28.31±21.87)mmol/L]、锌含量[(2.67±1.47)mmol/L]均显著高于G1组[(33.67±24.14)mU/1次射精,(20.78±16.04)mmol/L,(2.21±1.01)mmol/L]和G2组[(42.05±30.63)mU/1次射精,(24.58±19.21)mmol/L,(2.07±1.01)mmol/L](P＜0.01,P＜0.05).结论 禁欲时间影响精子参数和精浆生化指标.     

特发性少弱精患者精浆α-葡糖苷酶、锌与精子形态学参数相关性分析

目的分析特发性少弱精患者精浆α-葡糖苷酶活性、锌含量与精子形态学相关参数的相关性。方法 152例特发性少弱精患者根据形态学分析分成5组,采用计算机辅助精子分析(CASA)、Diff-Quik染色法分析精液质量、精子形态,利用速率法、PAN法及全自动生化分析仪检测精浆α-葡糖苷酶活性和锌水平。结果正常精子形态百分率在3%~4%、2%~3%、1%~2%、0%~1%4组与正常精子形态百分率≥4%比较,精浆α-葡糖苷酶活性均有显著性差异(Z分别为-2.199、-2.685、-2.827、-3.358,P0.05),其余各组之间比较差异均无统计学意义(P0.05);精浆锌水平各组比较差异无统计学意义(P0.05)。精浆α-葡糖苷酶活性与正常形态精子百分率呈正相关(P0.05),与精子畸形指数(SDI)呈负相关(P0.05),与精子头部、颈部和中段、尾部、过量残留胞浆、多重异常指数(MAI)、畸形精子指数(TZI)无明显相关性(P0.05);精浆锌水平与各项精子形态学参数均无相关性(P0.05)。结论正常精子形态百分率异常的特发性少弱精患者精浆α-葡糖苷酶活性明显低于精子形态正常的患者;精浆α-葡糖苷酶活性与正常形态精子百分率呈正相关,与SDI呈负相关,可能有利于体外受精。     

Plasma clusterin concentration is associated with longitudinal brain atrophy in mild cognitive impairment

Recent genetic and proteomic studies demonstrate that clusterin/apolipoprotein-J is associated with risk, pathology, and progression of Alzheimer's disease (AD). Our main aim was to examine associations between plasma clusterin concentration and longitudinal changes in brain volume in normal aging and mild cognitive impairment (MCI). A secondary objective was to examine associations between peripheral concentration of clusterin and its concentration in the brain within regions that undergo neuropathological changes in AD. Non-demented individuals (N = 139; mean baseline age 70.5 years) received annual volumetric MRI (912 MRI scans in total) over a mean six-year interval. Sixteen participants (92 MRI scans in total) were diagnosed during the course of the study with amnestic MCI. Clusterin concentration was assayed by ELISA in plasma samples collected within a year of the baseline MRI. Mixed effects regression models investigated whether plasma clusterin concentration was associated with rates of brain atrophy for control and MCI groups and whether these associations differed between groups. In a separate autopsy sample of individuals with AD (N = 17) and healthy controls (N = 4), we examined the association between antemortem clusterin concentration in plasma and postmortem levels in the superior temporal gyrus, hippocampus and cerebellum. The associations of plasma clusterin concentration with rates of change in brain volume were significantly different between MCI and control groups in several volumes including whole brain, ventricular CSF, temporal gray matter as well as parahippocampal, superior temporal and cingulate gyri. Within the MCI but not control group, higher baseline concentration of plasma clusterin was associated with slower rates of brain atrophy in these regions. In the combined autopsy sample of AD and control cases, representing a range of severity in AD pathology, we observed a significant association between clusterin concentration in the plasma and that in the superior temporal gyrus. Our findings suggest that clusterin, a plasma protein with roles in amyloid clearance, complement inhibition and apoptosis, is associated with rate of brain atrophy in MCI. Furthermore, peripheral concentration of clusterin also appears to reflect its concentration within brain regions vulnerable to AD pathology. These findings in combination suggest an influence of this multi-functional protein on early stages of progression in AD pathology.     

男性不育症患者精子核蛋白组型转换异常的检测与分析

目的 观察男性不育症患者精子核蛋白组型转换的异常并分析其临床意义.方法 对不育症患者用精子核蛋白组型转换半定量试剂和DNA荧光染色精子动(静)态图像分析系统进行检测分析.结果 261例患者中核蛋白组型转换异常66例,占25.3%.结论 核蛋白组型转换异常与精子密度、活力降低密切相关,是反映精子授精能力的一项指标.