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1.
The purpose of this study is to gain understanding of the relationship between ejaculation and serum testosterone level in
men. The serum testosterone concentrations of 28 volunteers were investigated daily during abstinence periods after ejaculation
for two phases. The authors found that the fluctuations of testosterone levels from the 2nd to 5th day of abstinence were
minimal. On the 7th day of abstinence, however, a clear peak of serum testosterone appeared, reaching 145.7% of the baseline
(P<0.01). No regular fluctuation was observed following continuous abstinence after the peak. Ejaculation is the precondition
and beginning of the special periodic serum testosterone level variations, which would not occur without ejaculation. The
results showed that ejaculation-caused variations were characterized by a peak on the 7th day of abstinence; and that the
effective time of anejaculation, is 7 days minimum. These data are the first to document the phenomenon of the periodic change
in serum testosterone level; the correlation between ejaculation and periodic change in the serum testosterone level, and
the pattern and characteristics of the periodic change. 相似文献
2.
观察血清基质金属蛋白酶-9（MMP-9）及血管内皮生长因子（VEGF）在实验性新西兰白兔蛛网膜下腔出血后的浓度变化,探讨它们与脑血管痉挛发生、发展及转归过程的关系,为临床诊断及治疗提供理论依据。实验结果表明血清MMP-9及VEGF的浓度变化可以作为预测蛛网膜下腔出血后脑血管痉挛的发作、判断其发展及预后的参考指标之一,为临床诊断与治疗提供依据。MMP-9及VEGF参与了蛛网膜下腔出血后的病理生理过程,与迟发性脑血管痉挛的发病机制有密切关系。 相似文献
3.
目的:了解原发性低钾型周期性麻痹患者血清肌酶学的异常改变及其规律.方法:回顾性分析42例原发性低钾型周期性麻痹患者的临床资料,探讨其血清肌酶学的异常改变及规律.结果:原发性低钾型周期性麻痹患者肌酶学各项指标普遍有不同程度升高,其中肌酸激酶(CK)升高最为突出.肌酶改变呈现一定规律.结论:血清肌酶学各项指标普遍升高且呈一定规律性,是原发性低钾型周期性麻痹的临床特征的重要组成部份. 相似文献
4.
Study on the neurotoxic effects of low-level lead exposure in rats 总被引：10，自引：0，他引：10
Objective: To investigate effects of developmental lead exposure on nitric oxide synthase (NOS) activity in different brain regions and on N-methyl-D-aspartate (NMDA) receptor mRNA expression in the hippocampus of rats. On the basis of these observations, we explored possible mechanisms by which lead exposure leads to impaired learning and memorizing abilities in children. Methods: A series of rat animal models exposed to low levels of lead during the developing period was established (drinking water containing 0.025%, 0.05% and 0.075% lead acetate). NOS activities in the hippocampus, the cerebral cortex, the cerebellum and the brain stem were determined with fluorescence measurement and levels of mRNA expression of the NMDA receptor 2A (NR2A) subunit and NMDA receptor 2B (NR2B) subunit in the rat hippocampus were measured with Retro-translation (RT-PCR). Results: There were no differences in the body weight of rat pups between any of the groups at any given time (P>0.05). The blood lead level of Pb-exposed rat pups showed a systematic pattern of change: at 14 d of age, it was lower than that at 7 d of age, then rising to the peak level at 21 d and finally falling to lower levels at 28 d. The hippocampal NOS activities of lead-exposed groups were all lower than that of the control group on the 21st and 28th day (P<0.01). NOS activities in the cerebellum of lead-exposed groups were all lower than that of the control group on the 21st and 28th day (P<0.001) and the NOS activity of the 0.025% group was significantly lower than that of the 0.05% and 0.075% groups on the 28th day (P<0.05). NOS activity in the cerebral cortex of the 0.075% group was significantly lower than that of the control, 0.025% and 0.05% groups on the four day spans (P<0.001). There was no significant difference of NOS activity in the brain stem between any lead-exposed group and the control group on the four day spans. In the 0.05% and the 0.075% groups, the level of NR2A mRNA expression was higher than that in the control group at 7 d and 14 d of age (P<0.05). In the 0.025% group, the level of NR2A was found to be higher than that in the control group at 7 d of age only (P<0.05). No significant differences were found for the levels of NR2B mRNA expression between any of the groups at any given time. Conclusions: NOS activity in the hippocampus, the cerebral cortex and the cerebellum are inhibited by lead exposure. The degree of the inhibitory effect depends on the time span of exposure and the lead concentration. Developmental low-level lead exposure was found to raise the level of NR2A mRNA expression in the hippocampus of rats. Developmental low-level lead exposure does not affect the level of NR2B mRNA expression in the hippocampus. 相似文献
5.
Thawatchai Prabsattroo Jintanaporn Wattanathorn Sitthichai Iamsaard Pichet Somsapt Opass Sritragool Wipawee Thukhummee Supaporn Muchimapura 《Journal of Zhejiang University. Science. B》2015,16(3):179-190
Aphrodisiacs are required to improve male sexual function under stressful conditions. Due to the effects of oxidative stress and dopamine on male sexual function, we hypothesized that Moringa oleifera leaves might improve male sexual dysfunction induced by stress. Therefore, the effects on various factors playing important roles in male sexual behavior, such as antioxidant effects, the suppression of monoamine and phosphodiesterase type 5 (PDE-5) activities, serum testosterone and corticosterone levels, and histomorphological changes in the testes, of a hydroethanolic extract of M. oleifera leaves were investigated. Various doses of extract including 10, 50, and 250 mg/kg body weight (BW) were given orally to male Wistar rats before exposure to 12 h-immobilization stress for 7 d. The results demonstrated that the extract showed both antioxidant and monoamine oxidase type B (MAO-B) suppression activities. At 7 d of treatment, the low dose of extract improved sexual performance in stress-exposed rats by decreasing intromission latency and increasing intromission frequency. It also suppressed PDE-5 activity, decreased serum corticosterone level, but increased serum testosterone, numbers of interstitial cells of Leydig and spermatozoa. The increased numbers of interstitial cells of Leydig and spermatozoa might have been due to the antioxidant effect of the extract. The increased sexual performance during the intromission phase might have been due to the suppression of MAO-B and PDE-5 activities and increased testosterone. Therefore, M. oleifera is a potential aphrodisiac, but further research concerning the precise underlying mechanisms is still needed. 相似文献
6.
目的:在康脑液方剂干预下观察皮质区内源性神经细胞干细胞因子(SCF)mRNA在大鼠脑缺血再灌注损伤后不同时间的表达情况。方法:成年SD大鼠,以线栓法建立大脑中动脉缺血再灌注模型,随机分为模型组、药物干预组和假手术组。原位杂交技术检测脑缺血1.5h再灌注1～14d后,脑皮质区SCFmRNA表达情况。结果:脑缺血再灌注后,药物干预组、模型组SCFmRNA的表达在皮质区均明显高于假手术组,于第7天达高峰,第14天下降。结论:药物干预后脑缺血再灌注脑皮质区SCFmRNA表达在不同时间点与模型组具备相同的表达规律,两组SCFmRNA的表达无显著性差异。 相似文献
7.
目的探讨男童血清瘦素水平与肥胖及性发育的关系。方法选择9—14岁符合单纯性肥胖标准的男性患儿34例为肥胖组,健康男性儿童32例为对照组,分别计算体重指数（BMI）、应用放射性免疫法测定血清瘦素（Leptin）水平、化学发光法测定血清雌二醇（E2）及睾酮（T）水平,用游标卡尺测量并计算睾丸体积,应用SPSS16．0软件进行组间t检验比较两组间差异,线性相关分析肥胖男童血清瘦素水平与BMI,E2及T之间的相关性。结果肥胖男童血清瘦素、雌二醇水平及BMI均较对照组儿童高,且差异有统计学意义（P〈0．01）;肥胖男童血清睾酮水平及睾丸体积均较对照组儿童低,且差异有统计学意义（P〈0．01）。肥胖男童血清瘦素水平与BMI呈正相关（r=0．69,P〈0.01）,与雌二醇呈正相关（r=0．381,P〈0.05）,与睾酮呈负相关（r=-0.347,P〈0.05）。结论肥胖男童存在瘦素抵抗现象,且有性发育不良的趋势。 相似文献
8.
Silvia Wen-Yu Lee 《International Journal of Science and Mathematics Education》2018,16(8):1409-1430
The purpose of this study was, first, to understand the item hierarchy regarding students’ understanding of scientific models and modeling (USM). Secondly, this study investigated Taiwanese students’ USM progression from 7th to 12th grade, and after participating in a model-based curriculum. The questionnaire items were developed based on 6 aspects of USM, namely, model type, model content, constructed nature of models, multiple models, change of models, and purpose of models. Moreover, 10 representations of models were included for surveying what a model is. Results show that the purpose of models and model type items covered a wide range of item difficulties. At the one end, items for the purpose of models are most likely to be endorsed by the students, except for the item “models are used to predict.” At the other end, the “model type” items tended to be difficult. The students were least likely to agree that models can be text, mathematical, or dynamic. The items of the constructed nature of models were consistently located above the average, while the change of models items were consistently located around the mean level of difficulty. In terms of the natural progression of USM, the results show significant differences between 7th grade and all grades above 10th, and between 8th grade and 12th grade. The students in the 7th grade intervention group performed better than the students in the 7th and 8th grades who received no special instruction on models. 相似文献
9.
INTRODUCTION Polychlorinated biphenyls (PCBs) are members of the halogenated hydrocarbon class of lipophilic environmental endocrine disrupters that includes the dibenzofurans and dioxins. Their appearance in the ecosystem and in the tissues from wildlife, as well as documented cases of accidental poisoning led to the banning of their manufacture in 1977 (Tilson and Kodavanti, 1997). The PCBs continue to be of concern to biologists due to reports that exposure to relatively low levels… 相似文献
10.
The effects ofpolychlorinated biphenyls (PCBs) on reproduction of adult cocks were studied by gavaging peanut oil or PCBs (Aroclor 1254, 50 mg/kg) once a week for six consecutive weeks. Physiological parameters were recorded and gonads were removed at the end of experiment for histological examination. The results showed that there was no significant difference between the control and treatment group in body weight, respiration rate, heart rate, body temperature, and the numbers of red and white blood cells. However, there was a marked decrease in the testicular weight and serum testosterone level after PCB treatment. Morphological studies manifested severe damage of the seminiferous tubules by PCB. The number of the germ cells at the different developmental stages was decreased and condensed nuclei were observed in most of these cells. This study revealed that the reproductive function of the adult cocks is sensitive to PCBs, which inhibited mainly spermatogenesis and testosterone secretion. 相似文献
11.
银杏叶愈伤组织增殖过程中生理生化特性的研究 总被引：2，自引：0，他引：2
本文系统研究了银杏叶愈伤组织培养细胞的生长周期,并对培养过程中细胞内的可溶性蛋白的含量,过氧化物酶、苯丙氨酸解氨酶活性的变化以及银杏总黄酮的含量进行了测定,以期为银杏细胞的大规模培养积累数据。 相似文献
12.
范伟荣 《金华职业技术学院学报》2013,(6):74-77
目的：探讨不同止血方法对腹腔镜卵巢囊肿剔除术后年轻患者卵巢储备功能的影响。方法：将2009年12月至2011年12月因单侧良性卵巢囊肿且年龄≤35岁的住院患者83例随机分为缝合组与电凝组．两组分别于术前、术后,1、6个月后第一次月经的第2-5天检测血清雌二醇（E：）、卵泡刺激素（FSH）及黄体生成素（LH）水平;阴道彩超检测窦卵泡数（AFC）和卵巢间质动脉血流的收缩期峰值（PSV）;以两者结合判定卵巢储备功能。结果：术前激素水平两组间差异无统计学意义（P〉0．05）;术后1、6个月E2、FSH水平与术前比较,缝合组无差异（P〉0．05）、电凝组有差异（P〈0．05）、两组间比较有统计学意义（P〈0．05）,LH水平差异无统计学意义（P〉0．05）;术后1、6个月AFC、PSV水平差异与术前比较,缝合组组内、组间均无统计学意义（P〉0．05）,电凝组组内、组间均有统计学意义;术后共发生卵巢储备功能下降者缝合组10．8％,电凝组15.2％。结论：腹腔镜下卵巢囊肿剔除术两种止血方法对卵巢储备功能均有影响,电凝止血法较单纯缝合止血法所致卵巢储备功能下降更加明显。 相似文献
13.
目的:观测尾加压素Ⅱ受体拮抗剂palosuran对阿霉素肾病大鼠尿中尾加压素Ⅱ(UrotensinⅡ;UⅡ)的影响,从而探究palosuran对微小病变肾病综合征(minimal change ne-phropathy syndrome;MCNS)的作用。方法:采用雄性Wistar大鼠80只,体重100±20g。随机选择其中10只做为健康组,其余70只大鼠尾静脉一次性注射阿霉素5mg/kg建立动物模型。注射后第7天检测大鼠24小时尿蛋白定量,若大鼠尿蛋白>30mg/24h者为MCNS模型成功,不合格者予以剔除。将合格的大鼠,随机分成2组,一组设为微小病变型肾病模型组,另一组在微小病变型肾病模型的基础上采用palosuran混入饲料中给药方法喂养,设为干预组。在实验第14、21、28天检测各组大鼠采用放射免疫法检测各组大鼠尿UⅡ的水平。结果:健康组大鼠尿UⅡ第14、21、28天检测值分别是1.46±0.18 ng/mL,1.52±0.12 ng/mL,1.54±0.43 ng/mL;模型组分别是2.49±0.11 ng/mL,4.48±0.19 ng/mL,6.56±0.27 ng/mL;干预组分别是1.95±0.1ng/mL,3.31±0.15 ng/mL,2.58±0.21 ng/mL。随着时间的延续,模型组大鼠尿UⅡ进行性升高(P<0.05),而palosuran对肾病大鼠尿UⅡ水平有明显影响,差异有显著统计意义(P<0.05)。结论:palosuran可能通过抑制UⅡ的作用而对微小病变肾病大鼠肾损害产生保护作用。 相似文献
14.
Three experiments investigated temporal generalization in humans. In Experiment 1, a peak shift effect was produced when participants
were given intradimensional discrimination training. In Experiment 2, after training with a standard S1 and generalization
testing with an asymmetrical series of durations, generalization gradients moved toward the prevailing adaptation level. In
Experiment 3, generalization gradients showed a central tendency shift and moved away from the S1 and toward the mean of the
test series (of 11 stimulus durations) after participants received training with S1 and S2 durations that in one condition
were the 2nd and 4th and in another condition were the 4th and 2nd stimuli in the series, respectively. The results were inconsistent
with an absolute account of peak shift but were consistent with an adaptation level account of peak shift. 相似文献
15.
Protection of Carassius auratus Gibelio against infection by Aeromonas hydrophila using specific immunoglobulins from hen egg yolk 总被引：3，自引：0，他引：3
Specific immunoglobulin （IgY） from egg yolk against Aeromonas hydrophila was produced by immunization of White Leghorn hens with formalin-killed whole cells of A. hydrophila. ELISA test using A. hydrophila as the coating antigen revealed that the specific antibody titer started to increase in the egg yolk at the 13th day post-immunization （P/N=2.18）, reached the peak at the 56th day （P/N= 13.82）, and remained at high level until day 133 （P/N=7.03）. The antibody was purified by saturated ammonium sulphate with a recovery rate of 63.5%. The specific IgY inhibited the growth ofA. hydrophila at a concentration of 1.0 mg/ml during the 18 h incubation. Pre-treatment of polyploid gibel carps Carassius auratus Gibelio with specific IgY had a protection rate of 60% （6/10） against challenge with A. hydrophila, while none of the fishes in the control groups receiving sterile phosphate buffered saline （PBS） or non-specific IgY survived the challenge. Treatment of fishes with the specific IgY 4 h after the challenge also had lower mortality （70%, 7/10）, a 30% reduction against the control PBS or non-specific IgY groups （10/10）. These results indicate that specific IgY antibodies could be obtained easily from hens immunized with an inactivated A. hydrophila and could provide a novel alternative approach to control of diseases in fishes caused by this organism. 相似文献
16.
AbstractThis study sought to determine if human papillomavirus (HPV) vaccination rates are associated with teaching requirements for abstinence in state sex education laws and policies. A cross-sectional analysis was conducted assessing the association between abstinence education legislation and HPV vaccination rates in adolescents (aged 13–17?years). After adjustment for insurance coverage and household income, the level of abstinence education was not significantly associated with vaccination rates. However, a higher percentage of individuals uninsured was significantly and negatively associated with the vaccination rate. This suggests that HPV vaccination rates are associated with insurance coverage, but not with the degree to which sex education laws or policies emphasize abstinence. 相似文献
17.
不同贮藏方式对小白菜中硝酸盐、亚硝酸盐的含量变化会产生影响。研究结果表明,小白菜样品在不同的贮藏方式下硝酸盐含量为保鲜!冷冻!腌制;亚硝酸盐的含量在保鲜和冷冻处理下变化不明显;腌制贮藏初期亚硝酸盐含量逐渐升高,在第9天出现"亚硝峰",其峰值远远高于保鲜和冷冻贮藏,但随着腌制时间的延长亚硝酸盐含量迅速下降;小白菜在腌制情况下其亚硝酸盐的含量最高,在腌制当天其硝酸盐含量变化不大,而亚硝酸盐含量明显增高。 相似文献
18.
大鼠脑缺血再灌注后血清NSE变化和脑病理形态学改变的研究 总被引：2，自引：0，他引：2
目的 探讨大鼠脑缺血再灌注后血清神经元特异性烯醇化酶（ Ｎｅｕｒｏ－ ＳｐｅｃｉｆｉｃＥｎｏｌａｓｅ，ＮＳＥ）水平和脑组织病理形态改变及其相关性．方法采用线栓法将健康Ｓｐｒａｇｕｅ－Ｄａｗｌｅｙ（ＳＤ）大鼠制成大脑中动脉堵塞（Ｍｉｄｄｌｅ Ｃｅｒｅｂｒａｌ Ａｒｔｅｒｙ Ｏｃｃｌｕｓｉｏｎ，ＭＣＡＯ）２ｈ再灌注模型来探讨血清ＮＳＥ和脑组织病理形态改变的关系．将９０只ＳＤ大鼠分成脑缺血 ２ ｈ再灌注后 １、 ２、３、 ４、 ５天 ５个实验组（每组１０只），每个时间点备配一个假手术组（每组６只）．观测各组血清ＮＳＥ、脑梗塞灶体积及脑组织病理形态（脑组织大体标本、光镜和电镜的病理变化）．结果①脑缺血再灌注后脑梗塞灶体积逐渐增大，第３天达高峰（ｐ＜０．０５）；②血清ＮＳＥ水平在脑缺血再灌注后逐渐升高，第３天达高峰（ｐ＜０．０５），然后逐渐下降；③血清ＮＳＥ水平与脑梗塞灶体积呈正相关（ｒ＝０．９２，ｐ＜０．００１）；④脑组织病理形态大体、光镜及电镜脑组织病理检查可见神经组织缺血坏死改变于第３天最明显，并且在第３天时缺血脑组织中中性粒细胞ＰＭＮ（Ｐｏｌｙｍｏｒｐｈｏｎｕｃｌｅａｒ Ｌｅｕｋｏｃｙｔ，ＰＭＮ）浸润最明显．结论血清Ｎ? 相似文献
19.
Susan M. McHale Ji-Yeon Kim Aryn M. Dotterer Ann C. Crouter Alan Booth 《Child development》2009,80(2):482-495
This study charted the development of gendered personality qualities and activity interests from age 7 to age 19 in 364 first- and secondborn siblings from 185 White, middle/working-class families, assessed links between time in gendered social contexts (with mother, father, female peers, and male peers) and gender development, and tested whether changes in testosterone moderated links between time use and gender development. Multilevel models documented that patterns of change varied across dimensions of gender and by sex and birth order and that time in gendered social contexts was generally linked to development of more stereotypical qualities. Associations between time with mother and expressivity and time with father and instrumentality were stronger for youth with slower increases in testosterone. 相似文献
20.
Sitthichai IAMSAARD Jaturon BURAWAT Pipatpong KANLA Supatcharee ARUN Wannisa SUKHORUM Bungorn SRIPANIDKULCHAI Nongnut UABUNDIT Jintanaporn WATTATHORN Wiphawi HIPKAEO Duriya FONGMOON Hisatake KONDO 《Journal of Zhejiang University. Science. B》2014,15(6):548-555