男性腿黑激素和N-乙酰-5-羟色胺血浓度的观察

在三个年龄组的中国男性中,对其血液腿黑激素和 N-乙酰-5-羟色胺进行了定量观察。血样本分别于下午4—5时和夜间0—2时,从青春期前、成年和老年三个年龄组采取。分别采用二氯甲烷和甲醇提取血液中的腿黑激素和 N-乙酰-5-羟色胺,用放射免疫法进行测定。实验结果表明,腿黑激素血水平夜间呈节律性的升高,且其血浓度的降低与年龄相关。血液中 N-乙酰-5-羟色胺的水平可能呈昼高夜低的节律性,其血浓度的高低与年龄无关。     

The Somatic Function of the Germ Nucleus in Pseudourostyla cris tat a: Asexual Reproduction and Stomatogenesis

The micronuclei of the ciliated protozoan Pseudourostyla cristata were eliminated by amputation shortly before binary fusion. The amicronucleate cell lines derived from regenerants were maintained for more than a year. They exhibited a lower viability and reduced vigor in asexual propagation. There was some improvement in the growth of the cell lines 1 mo after operation, but the growth rate remained subnormal even up to 1 yr of culture. The exact cause of the poor growth and survival in the first 3 wk after operation, whether the loss of the micronucleus or operational damage, remains to be determined. It is nevertheless clear that the micronucleus is important for subsequent asexual propagation. The amicronucleate cell lines were permanently crippled in morphogenesis, unlike the situation in Paramecium amicronucleates in which stomatogenesis returned to near-normal during asexual propagation. They always included some cells with a characteristically defective adoral zone of membranelles, reduced number of frontal-ventral-transverse cirri, and reduced body length. They were also reluctant to encyst. It is evident that the micronucleus is important for maintaining normality of the oral apparatus. It is postulated that the permanent stomatogenic crippling of amicronucleates might be related to genomic reduction in the developing macronucleus in sexual reproduction, as exhibited by other hypotrichs. The morphological defects associated with the adoral zone of membranelles may be rationalized as arising from the spreading of a zone of degeneration in the cortex affecting the left edge of the membranelles.     

Anomalous Cases of Conjugation and Spontaneous Autogamy in Stylonychia mytilus: A Note on the Asexuality of Early Conjugants

Four types of anomalous conjugation were documented in Stylonychia mytilus. Type I pairs were formed between mates of different sizes. These pairs exhibited an abnormal site of fusion in at least one of the mates, and the mates might face each other ventrally throughout conjugation instead of the normal side-by-side position. Type I pairs underwent sexual nuclear development and proceeded with the first cortical reorganization as in normal conjugants. Type II involved pairing at the anterior ends of mates with ventral surfaces facing the same direction. These pairs also underwent sexual nuclear development. Hence, aberrant orientation of the mates, and also ectopic sites of cytoplasmic fusion, if extensive, would permit sexual development. Type III pairs were united ventral-to-ventral with their anterior-left sides at the adoral zone of membranelles, and remained as such throughout conjugation. In these pairs, nuclear and cortical events were typical of the asexual development of physiological reorganization. In Type IV pairs, one mate of the pair possessed a fission furrow and developed two sets of ciliature typical of binary fission, while the other mate might undergo physiological reorganization or binary fission. Type III and Type IV pairs thus reveal the asexual state of early conjugants, which can pursue either one of the two modes of asexual cortical reorganization; these cases reinforce the notion of overlap of asexual and sexual cycles during conjugation of hypotrichs. Spontaneous autogamy was documented for the first time for this genus. The autogamonts proceeded with nuclear development and with the first cortical reorganization. Some probably underwent second and third reorganizations, as in conjugants, but accompanied by abnormalities, particularly in the stages beyond fertilization. Post-autogamous clones were nonviable except for one dubious case.     

Bloom's syndrome. Discussion of the diagnosis concerning two cases of terminal leukemia in a sibship (author's transl)

Two brothers developed acute leukemia, one at the age of 7 months and the other at the age of 14 months. Both suffered from a staturoponderal retardation and the same malformation syndrome. The karyotype carried out only on the second child revealed breaks and chromatid changes. A diagnosis of Fanconi's anaemia can be discarbed since no blood cytopenia preceded the leukemia. Finally, the diagnosis of Bloom's syndrome prevailed despite the absence of telangiectatic erythema and the atypical chromosomal anomalies.     

Hysteresis in the response of stomatal conductance in Pinus sylvestris L needles to light: observations and a hypothesis

Abstract. The response of stomatal conductance in Pinus sylvestris L. to a sequence of progressively changed photon flux densities showed hysteresis when the direction of the sequence was reversed. Hysteresis was most evident when 1 h was allowed for stabilization at a temperature of 10°C and a leaf-air vapour pressure difference of 0.5 kPa. The hysteresis was largely eliminated by a stabilization time of 2.5 h or a temperature of 20°C. Elimination of self shading also largely eliminated the hysteresis and resulted in light saturation of stomatal conductance at about 600 μE m⁻² s⁻¹ whereas with the normal grouping of fasicles light saturation was not achieved at 1750 μE m⁻² s⁻¹ even with bilateral illumination. Hysteresis was also eliminated by reduction in the maximum attainable conductance as a result of large leaf-air vapour pressure differences (> 1.8 kPa) but reducing the ambient CO₂ concentration to the compensation concentration or below had no effect on hysteresis. In addition to the hysteresis, there was a carry-over effect of the previous treatment. When the direction of the sequence of photon flux densities was changed, stomatal conductance continued to change in the direction appropriate to the previous sequence for at least 1 h. The presence of a transportable chemical intermediate is postulated, the amount or activity of which would take some time to change after a change in photon flux density. The presence of such an intermediate could account for both the sluggishness of the stomata and the carry over effect. As a result of the sluggish behaviour and carryover, in the field stomatal conductance will tend to follow the general trend in photon flux density and will be very insensitive to short term fluctuations.     

The Concept of Electroosmotically Driven Flow and Its Application to Biomimetics

1　IntroductionOneaimofthephysicsscienceresearchistodevel opfundamentalandportableconceptswhichhelpunitedifferentresearchfrontiers.Inthisrespect ,Helmholtz’selectricdoublelayer (DEL)theory ,whichwasdevel opedin 1879andrelatedtheelectricandflowparame tersforelectrokinetictransport ,isaseminal,havingprovidedaframeworkforinterpretingawiderangeofelectrokineticphenomena .DespitethesimplicityoftheEDLtheory ,whichwewilldescribeindetail,ithasprovidedachallengeformathematicianstounderstanditsimplic…     

犬蝠夜栖息地及夜栖息巢特征的初步研究

<正>大多数种类的蝙蝠不会整个晚上都进行觅食,通常在觅食期间有一段长短不一的时间停留在临时地休息,此为夜栖息行为(Hatfield,1937;Krutzsch,1954;Barbour and Davis,1969;Kunz,1973,1974;Hirshfeld et al.,1977)。蝙蝠在夜栖息地进食(Vaughan,1976;Funakoshi and Maeda,2003)、休息并消化食物(Brigham,1991;Funakoshi and Maeda,2003),甚至社会交流(Kunz,1982;Kunz and Lumsden,2003)。不同种类的蝙蝠     

通用流感疫苗研究进展

流感是一种对人类危害极大的传染病,接种疫苗被认为是预防流感的最有效手段。目前所用的流感疫苗主要是根据现行流行株的减毒或灭活病毒疫苗及基于流感血凝素和神经氨酸酶设计的重组蛋白质疫苗。但流感病毒变异大,易逃逸机体免疫监视,有效的疫苗须不断分离新流行株和不断更新疫苗免疫原。为解决这一问题,很多科学家一直在研究基于病毒高度保守性蛋白质、能够预防所有流感病毒毒株、可诱导持久保护性免疫的通用流感疫苗。我们对基于基质蛋白M2、核蛋白等的通用流感疫苗做一简要综述。     

神经元限制性沉默因子在NTera2/CloneD1细胞向神经元分化模型中表达的检测

目的:建立NTera2/CloneD1细胞向神经元分化的模型,检测神经元限制性沉默因子(NRSF)经分化培养基诱导后表达的变化。方法:收集正常培养的NTera2/CloneD1细胞及经全反式维甲酸(RA)、阿糖胞苷(AraC)、尿苷分阶段诱导共28 d的细胞,显微镜下观察诱导前后细胞的形态学变化;免疫荧光法检测NTera2/CloneD1细胞诱导前后干性标志Nestin、Sox2和成熟神经元特异性标志NF-200、β-tubulinⅢ的表达情况;应用RT-PCR和免疫荧光法对NRSF进行mRNA和蛋白水平的检测。结果:显微镜下观察到正常培养的NTera2/CloneD1细胞呈克隆样生长,经分化培养基诱导后的NTera2/CloneD1细胞表现出典型的神经元样细胞形态。免疫荧光检测表明,未诱导的NTera2/CloneD1细胞表达神经干细胞的标志Sox2、Nestin,不表达成熟神经元特异性蛋白NF-200、β-tubulinⅢ;而经RA等诱导分化的细胞则不表达Sox2、Nestin,表达NF-200、β-tubulinⅢ。RT-PCR和免疫荧光检测显示,NRSF在诱导分化后的NTera2/CloneD1细胞中的表达量显著降低。结论:建立了NTera2/CloneD1细胞向神经元分化的模型,NRSF在诱导后的NTera2/CloneD1细胞中表达量显著下调,提示NTera2/CloneD1细胞在诱导过程中可能通过下调NRSF,使受到NRSF负性调控的神经元特异性蛋白启动表达并上调,进而实现NTera2/CloneD1细胞向神经元的定向分化。     

声触诊组织定量技术鉴别诊断甲状腺微小癌的价值

目的：声触诊组织定量技术（VTQ）是一种新的弹性成像方法,能够定量、无创地评价组织硬度信息。本文的研究目的是探讨声触诊组织定量技术在鉴别诊断甲状腺微小癌（TMCs）中的应用价值。方法：应用VTQ 技术对110 例共114 个结节（最大直径≤1 cm）进行检测,获取并分析结节及周边甲状腺组织的横向剪切波速度（SWV）。利用ROC曲线对测量结果进行分析,评价VTQ技术的诊断价值并确定最佳诊断界值。结果：114 个结节中良性结节32 个（30 个为结节性甲状腺肿,2 个为腺瘤）,恶性结节82 个（均为乳头状癌）。甲状腺良性结节及周边甲状腺组织的SWV 平均值分别为（2.30± 0.49） m/s、（2.08± 0.40） m/s,恶性结节及周边甲状腺组织的SWV 平均值分别为（3.12± 0.97） m/s、（2.06± 0.46） m/s。恶性结节的SWV 值明显高于良性结节,两者之间差异具有统计学意义（t=5.911,P＜0.0001）;恶性结节与其周边甲状腺组织比较有显著差异（P＜0.0001）;而良性结节与其周边甲状腺组织无统计学差异（P＞0.05）。ROC曲线下面积为0.833,以2.30 m/s诊断界值点时,敏感度、特异度分别为90.2%、62.5%。结论：甲状腺恶性结节的SWV 值明显高于良性结节。VTQ 技术能够提供组织硬度信息,在鉴别诊断甲状腺微小癌方面具有一定的临床应用价值。