Ultrastructure of Pollen Grains from Forced and Unforced Shrubs of Common Lilac

Forcing makes possible to induce plant flowering independently of the season. In lilac, high temperature is the factor that breaks deep dormancy. The deepest dormancy occurs between the end of October and the end of December. Depending on the depth of dormancy, the starting temperatures required for forcing are 37°C in November, 31°C in December, and 25°C in January–March. Under natural conditions, the temperature inducing the inflorescence bud breaking is 6°C, whereas 9°C and 13°C or more allow inflorescence elongation and flowering, respectively (Kronenberg, 1994). In the present work, the effect of high temperature at the beginning of the forcing cycle on the structure of developing pollen grains of common lilac was investigated. Pollen grains from the outdoor-grown (control) shrubs showed no signs of degeneration. They were spherical, three-colpate to colporoidate, and bicellular, and contained large numbers of lipid bodies. High temperatures at the early forcing cycle (November) resulted in the degeneration of most microspores. The first signs of degeneration (cytoplasm plasmolysis) were observed at the tetrad stage and in mature anthers; the microspores consisted only of the outer and inner sporopolenin layers.     

HSP90 mRNA在胃癌和大肠癌中表达的研究

目的为探讨胃癌和大肠癌细胞HSP90 mRNA表达的特点.方法利用核酸原位杂交技术,对79例胃肠癌组织进行检测.结果表明HSP90 mRNA在胃癌和大肠癌中的阳性率分别为55.56%(15/27)和69.23%(36/52).mRNA表达与病理类型、分化程度和有否淋巴结转移有相关性.结论 HSP90 mRNA在胃肠癌中有较高表达,检测HSP90 mRNA可以作为提示预后的重要临床指标.     

叶绿体小分子量热激蛋白介绍

本文对叶绿体小分子量热激蛋白的研究进行了简要的回顾和总结.叶绿体小分子量热激蛋白是热激蛋白超家族的成员,具有3个特殊的保守区域;当植物遇到热胁迫时,叶绿体小分子量热激蛋白能够保护光合系统Ⅱ和类囊体膜;初步分析了叶绿体小分子量热激蛋白与植物的耐热性和耐冷性关系以及其分子伴侣功能.     

甜椒细胞质小分子量热激蛋白基因(CaHSP18)的cDNA克隆与表达

用RT-PCR和RACE-PCR技术,从热激处理的甜椒叶片总RNA中扩增出了细胞质小分子量热激蛋白(sHSP)全长779 bp的cDNA基因序列,包含一个480 bp开放阅读框,编码159个氨基酸.Southern杂交结果表明在甜椒基因组中有该基因的小的多基因家族.Northern结果显示该基因在甜椒根、茎、叶中的表达受热激和低温的诱导.原核表达分析表明该基因在高温以及低温条件下可以提高大肠杆菌的生存能力.     

Effects of weak laser radiation (632.8 nm) on isolated mouse immune cells

The dose dependence of in vitro effects of low-intensity radiation of a He-Ne laser (632.8 nm, 0.2 mW/cm²) on the functional activity of peritoneal macrophages and lymphocytes of mouse spleen was studied. The exposure of isolated cells was varied from 5 to 180 s. If the exposure did not exceed 60 s, stimulation of secretory activity was observed: increased production of interleukin 2, interferon γ, and interleukin 6 in lymphocytes; increased production of tumor necrosis factor α, nitric oxide, and interleukin 6 in macrophages; and enhanced activity of natural killer cells. A longer exposure (up to 180 s) either had no effect on the synthesis of certain cytokines (interleukin 2 in lymphocytes and interleukin 6 in macrophages) or inhibited it, which was expressed in decreased production of interleukin 6 and interferon γ in lymphocytes and nitric oxide in macrophages, as well as in suppression of the activity of natural killer cells. Conversely, the production of interleukin 3 decreased after a short-term exposure but increased after 180-s irradiation. The high sensitivity of cells to extremely weak laser light also manifested itself as a considerable increase in expression of the inducible heat shock protein 70; this effect was observed at all doses studied, including the 5-s exposure. In contrast, expression of the heat shock protein 90 slightly decreased after irradiation of cells with laser light.     

量子点荧光技术标记肿瘤细胞中HSP的应用研究

目的探讨量子点荧光技术对人肾癌细胞株(ACHN)中不同HSP进行标记的可行性应用。方法利用量子点的荧光特性,免疫细胞化学方法检测体外培养的ACHN细胞中量子点特异性标记的HSP70、HSP90、HSPgp96的表达情况。结果共聚焦荧光显微镜下可见ACHN细胞中HSP70、HSP90、HSPgp96均有明显表达,呈现均匀分布的橙红色强荧光,且量子点在持续激发30分钟后无荧光淬灭发生。结论量子点荧光标记技术能够对不同HSP进行标记,且与传统的标记方法相比具有显著优点,可作为一种新型的检测技术应用于科研及临床标记检测中。     

Indicators of physiological stress and the elaboration of sexual traits in the collared flycatcher

Stress may have consequences for the evolution of condition-dependentsexual traits. For example, stress may be related to sexualtraits through immune function, and sexual traits can reflecthow individuals bear the costs of stress-mediated immunosuppression.However, male traits may be directly associated with stress,and such traits would then indicate stress tolerance. Here,we present initial results for the relationship between physiologicalstress estimated by the levels of heat shock proteins (HSP60and HSP70) and heterophil/lymphocyte ratio and the elaborationof sexual traits, such as forehead and wing patch size and songfeatures in the collared flycatcher Ficedula albicollis. Malesproducing longer and more versatile songs had significantlyhigher levels of HSP70, but other traits were unrelated to stress.In general, effect sizes for the relationship between stressand sexual traits had broad confidence intervals and variedbetween being small and medium effects. Immunoglobulin levels,leukocyte abundance, haemoparasite prevalence, male age, anddate and time effects did not affect the relationship betweenstress and sexual traits. These preliminary results, servinga basis for further experimental studies indicate that the relationshipbetween sexual traits and stress does not seem to be strong,but stress may partially constrain the expression of some sexualtraits.     

Effects of corticotropin-releasing hormone on proopiomelanocortin derivatives and monocytic HLA-DR expression in patients with septic shock

Little is known about interactions between immune and neuro-endocrine systems in patients with septic shock. We therefore evaluated whether the corticotropin-releasing hormone (CRH) and/or proopiomelanocortin (POMC) derivatives [ACTH, β-endorphin (β-END), β-lipotropin (β-LPH), α-melanocyte stimulating hormone (α-MSH) or N-acetyl-β-END (Nac-β-END)] have any influences on monocyte deactivation as a major factor of immunosuppression under septic shock conditions. Sixteen patients with septic shock were enrolled in a double-blind, cross-over and placebo controlled clinical study; 0.5 μg/(kg_bodyweight h) CRH (or placebo) were intravenously administered for 24 h. Using flow cytometry we investigated the immunosuppression in patients as far as related to the loss of leukocyte surface antigen-DR expression on circulating monocytes (mHLA-DR). ACTH, β-END immunoreacive material (IRM), β-LPH IRM, α-MSH and Nac-β-END IRM as well as TNF-α and mHLA-DR expression were determined before, during and after treatment with CRH (or placebo). A significant correlation between plasma concentration of α-MSH and mHLA-DR expression and an inverse correlation between mHLA-DR expression and TNF-α plasma level were found. Additionally, a significant increase of mHLA-DR expression was observed 16 h after starting the CRH infusion; 8 h later, the mHLA-DR expression had decreased again. Our results indicate that the up-regulation of mHLA-DR expression after CRH infusion is not dependent on the release of POMC derivatives. From the correlation between plasma concentration of α-MSH and mHLA-DR expression, we conclude that in patients with septic shock the down-regulation of mHAL-DR expression is accompanied by the loss of monocytic release of α-MSH into the cardiovascular compartment.