不同番茄品种对缺钙敏感性的差异

分别在苗期和果实成熟期对不同品种番茄对缺钙反应的敏感性进行了研究。钙效率的高低是衡量番茄对缺钙敏感性的重要指标。苗期聚类分析表明,33个品种可以被分为3个大类,分别是钙高效品种(7个)、钙低效品种(5个)和钙中效品种(21个),钙效率系数平均值分别为87％、49．5％和70．2％。缺钙条件下钙效率越高的品种其根部、地上部吸收和积累钙的能力越强,吸钙量越高;在正常供钙条件下,钙系数与植株的根、地上部及整株的吸钙量成显著负相关关系,表明充足供钙使钙低效品种吸钙能力增加,且增加的程度远大于钙高效品种,同时也表明钙低效品种具有在供钙充足时需钙量较大的特性。苗期钙效率与果实钙含量和果实钙效率及BER发生并不完全一致,苗期钙效率较低、果实钙含量也较低的品种BER发生率较高(No．4);而苗期钙效率较高的品种当果实钙含量较低时也可完全减少BER的发生(No．3);低钙培养对No．5品种果实钙含量无显著影响,表明该品种较耐低钙胁迫。因此,在进一步的机理研究中可以选择No．5和No．4作为耐低钙和不耐低钙的试验材料。     

正常猫的心电图分析

本组资料对戊巴比妥钠麻醉猫的肢导联和胸导联心电图数据做了统计整理,与前人的乌拉坦麻醉猫的肢导联心电图资料做了比较。并就猫与人在解剖生理上的差异造成的对心电图的影响做了分析。 总的来看,猫的心电图有其特点,但基本波型与人相似。不同的麻醉药物对猫心电图的影响似不大,但麻醉程度对心率及心电图各间期时程可产生一定影响。另外,猫心电图Q波振幅的个体差异较大。     

青年猫和老年猫视神经超微结构观察比较

目的探讨青年猫和老年猫视神经年龄相关的形态学变化及可能造成的生理影响。方法取4只青年猫(2-3岁,2-2.5kg)和4只老年猫(10-13岁,2.5-3.5kg)颅内相对应部分视神经,制作横向半薄切片和超薄切片,半薄切片用甲苯胺蓝硼砂溶液染色,光镜观察、测量视神经的直径(不含外层神经膜);超薄切片标本用醋酸和柠檬酸铅染色,电镜观察、计数视神经纤维密度、测量视神经纤维外径D(含髓鞘)和内径d(不含髓鞘),按一定分级范围算出各种直径的纤维及各种d/D比值的纤维所占百分比,分别画出直方图,对实验结果进行统计学分析并绘制纤维直径谱。结果与青年猫相比,老年猫视神经直径显著增大(P0.05);纤维数量显著下降(P0.05)。纤维直径谱分析结果显示,青、老年猫纤维直径分布范围相似,但老年猫纤维的峰直径及纤维平均直径比青年猫的显著减小(P0.05),老年猫视神经纤维的d/D比值亦明显降低。另外,老年猫视神经中部分轴突肿胀,髓鞘疏松、结构紊乱,板层脱离、空泡化,有的轴索髓鞘溶解。结论在衰老过程中,老年猫视神经纤维丢失,纤维直径减小,d/D比值下降,以及纤维髓鞘的松散解体,这些变化均可能导致视神经纤维对视觉信息的传导速度减慢,是老年个体视觉分析速度下降的重要原因。     

清醒猫与乌拉坦麻醉猫的心电图比较

本文对清醒站位、乌拉坦麻醉站位和仰卧位的猫心电图参数做了统计比较。乌拉坦麻醉可使猫心电图各波和间期时间延长,心率减慢。对各波振幅和出现率亦有不同程度影响,以11导联 Q 波变化较明显。麻醉后的不同体位对各导联图型影响不很明显。     

中国猫蛛属三新种(蜘蛛目,猫蛛科)

记述了中国湖南省猫蛛科Oxyopidae猫蛛属Oxyopes 3新种：环缘猫蛛Oxyopes annularis sp.nov.,弓缘猫蛛Oxy-opes arcuatus sp.nov.和带缘猫蛛Oxyopes balteiformis sp.nov.3新种的主要鉴别特征。环缘猫蛛,新种Oxyopes annularis sp．nov．与条纹猫蛛Oxyopes striagntus Song,1991相似,但新种腹部细长,末端特别尖细;外雌器角质化后缘拱起较宽长,呈半圆形,其前缘正中尚有两个小疣突,后者角质化后缘拱起较窄短,呈蛇头状,正中没有成对小疣突。弓形猫蛛,新种Oxyopes arcuatus sp．nov．与尖峰猫蛛Oxyopes jianfeng Song,1991相似,但新种外雌器角质化后缘弯曲呈弓形,近乎半圆,后者条状,近乎平直,仅两侧端稍有弯曲;纳精囊较大,交媾管远端细,弯曲呈圆圈,近端变粗呈漏斗形,后者交媾管粗细均匀,远端平直折向近端。不呈漏斗状。带缘猫蛛,新种Oxyopes balteiformis sp．nov．与细纹猫蛛Oxyopes macilentus L.Koch,1878相似,但新种外雌器角质化后缘呈横向带状,较宽,正中无任何突起结构,后者角质化后缘腹面正中有一个三角形突起,背面观在阴门正中有一个“T”形脊。     

中国猫蛛属一新种(蜘蛛目:猫蛛科)

记述中国湖南省猫蛛科Oxyopidac猫蛛属Oxyopes 1新种：壶瓶猫蛛Oxyopes hupingensis sp.nov.。新种不同于本属内其它种。新种与Oxyppes daksina Sherriffs,1955略相似,两者的纳精囊都处于外雌器的中线位置上,但新种在如下几方面不同于后者：交媾腔大,葫芦状;纳精囊从内向外,从后向前扭曲成“U”形;两纳精囊彼此靠近。模式标本保存于湖南师范大学生命科学学院。文中量度单位为mm。     

老虎感染猫传染性鼻-结膜炎病毒的研究

用猫肾传代细胞从发病虎的病料中分到了一株杯状病毒粒子样病毒.该病毒大小为35～39nm、无囊膜、在胞浆中病毒前体呈晶格状排列,抗乙醚、不能被 5-IUDR所抑制,能被来源于标准疫苗的猫传染性鼻-结膜炎病毒(或杯状病毒Feline calicivirus, FCV)抗血清所中和,人工感染猫出现典型的FCV感染症状.RT-PCR能扩增出与设计值相符的电泳带,PC R产物直接测序结果与Genebank发表的FCV序列比较,具有较高的同源性.系统鉴定证明所分离的这株病毒为FCV强毒株,从老虎中分到FCV在世界上尚属首次报道.     

正常猫的外周血象观察

本文报告了我国本地猫的外周血象正常值,其数据与国外学者所报道的基本一致。性别间无显著差异,但可受年龄因素的影响,其初生小猫和幼年猫的各项指标平均值,几乎均较低,随年龄增长有渐进增加趋向,达5月龄时,其数值基本上与成年猫一样。     

Excitation of cat spinal cord dorsal column fibers during stimulation of different fiber groups of cutaneous and somatic nerves

The effects of electrically stimulating different groups of nerve fibers supplying the skin and muscle on evoked potentials in cat spinal cord dorsal columns were studied. Significant differences in the configuration of dorsal column potentials recorded in response to stimulation of these nerves were found. It was shown that cutaneous nerve unmyelinated fibres were connected to unmyelinated dorsal column fibers. In addition, excitation of cutaneous C-fibers lead to activation of dorsal column fibers with the maximum conduction velocity. The somatic nerve was only connected to myelinated dorsal column fibers, and excitation of its non-myelinated fibers did not cause other types of dorsal column fibers to be activated. It is suggested that the acceleration of cutaneous signal transmission in the dorsal column system may be brought about by the necessity for rapid warning of potentially harmful stimuli.Medical Institute, Russian Federation Ministry of Public Health, Nizhny Novgorod. Translated from Neirofiziologiya, Vol. 24, No. 5, pp. 625–635, September–October, 1992.     

Mapping of tachykinins in the cat spinal cord

Using an indirect immunoperoxidase technique, the location of cell bodies and fibers containing substance P, neurokinin A and neurokinin B was studied in the cat spinal cord. The former two neuropeptides showed a widespread distribution throughout the whole spinal cord, whereas the distribution of neurokinin B was more restricted. Neurokinin A-immunoreactive structures showed a more widespread distribution and a higher density than the immunoreactive structures observed to contain substance P. In the cat spinal cord, we observed cell bodies containing neurokinin A, but no cell bodies containing neurokinin B or substance P were found. These cell bodies were located in laminae V (sacral 1 and 2 levels), VI (sacral 1 and 3), VII (lumbar 7, sacral 1 and 3, caudal 1) and X (sacral 1). Laminae I and II showed the highest density of immunoreactive fibers for each of the three tachykinins studied, being in general lamina IV who showed the lowest number of immunoreactive fibers containing substance P, neurokinin A or B. The anatomical distribution of the three tachykinins studied in the cat spinal cord indicates that the neuropeptides could be involved in the neurotransmission and/or in the neuromodulation of nociceptive information, as well as in autonomic and affective responses to pain. Moreover, the involvement of substance P, neurokinin A or B in other functions unrelated to the transmission of pain is also possible (autonomic and motor functions). The distribution of the neuropeptides studied in the cat is compared with the location of the same neuropeptides in the spinal cord of other species. The possible origin of the tachykinergic fibers in the cat spinal cord is also discussed.     

Moment-rotation responses of the human lumbosacral spinal column

The objective of this study was to test the hypothesis that the human lumbosacral joint behaves differently from L1-L5 joints and provides primary moment-rotation responses under pure moment flexion and extension and left and right lateral bending on a level-by-level basis. In addition, range of motion (ROM) and stiffness data were extracted from the moment-rotation responses. Ten T12-S1 column specimens with ages ranging from 27 to 68 years (mean: 50.6+/-13.2) were tested at a load level of 4.0 N m. Nonlinear flexion and extension and left and right lateral bending moment-rotation responses at each spinal level are reported in the form of a logarithmic function. The mean ROM was the greatest at the L5-S1 level under flexion (7.37+/-3.69 degrees) and extension (4.62+/-2.56 degrees) and at the L3-L4 level under lateral bending (4.04+/-1.11 degrees). The mean ROM was the least at the L1-L2 level under flexion (2.42+/-0.90 degrees), L2-L3 level under extension (1.58+/-0.63 degrees), and L1-L2 level under lateral bending (2.50+/-0.75 degrees). The present study proved the hypothesis that L5-S1 motions are significantly greater than L1-L5 motions under flexion and extension loadings, but the hypothesis was found to be untrue under the lateral bending mode. These experimental data are useful in the improved validation of FE models, which will increase the confidence of stress analysis and other modeling applications.     

Segmental norepinephrine and dopamine levels in cat spinal cord

Tissue levels of norepinephrine in the uninjured cat were determined by a fluorimetric or enzymatic radiometric assay technique. There were no significant differences of NE levels between the two techniques. The highest concentrations of NE were found in the cervical (.170 ug/g) and lumbar (.232 ug/g) enlargements and appear to be related to the relative amount of grey and white matter present at these levels. Dopamine levels, as determined by the enzymatic radiometric assay technique, were found to be low in those spinal segments measured (less than 0.030 ug/g). DA appears to be similarly distributed as norepinephrine in the spinal segments. Barbiturate or nitrous oxide anesthetic agents did not result in significant differences in NE determinations at cervical or thoracic segments. Variability of reported NE and DA levels from other studies appears to be related to differences in assay technique.     

Effects of 5-hydroxytryptamine on cat spinal motoneurons

The effects of 5-hydroxytryptamine (5-HT) on spinal motoneurons were examined in pentobarbital-anaesthetized cats and in nonanaesthetized decerebrate cats by intracellular recording and extracellular iontophoresis of 5-HT. 5-HT first induced a depolarization and then a long-lasting hyperpolarization (up to 60 min) with unchanged input resistance. The slow hyperpolarization was prevented by the 5-HT antagonists ketanserin (5-HT2), methysergide, and spiperone (5-HT1,2) and mimicked by the agonist (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (5-HT2). The post-spike after hyperpolarization was enhanced after application of 5-HT. A depolarization was induce by the 5-HT agonists (+/-)-8-hydroxy-(2)-(di-n-propylamino)tetralin (5-HT1A) and 1-(2-methoxyphenyl)piperazine (5-HT1). Possible mechanisms for the 5-HT-induced hyperpolarization and its intracellular medication are discussed. The present data suggest multiple effects of 5-HT on cat spinal motoneurons.