人参皂甙Rb1阻止大鼠局灶性脑缺血细胞凋亡和诱导NAIP表达

人参皂甙Rb1(GRb1)是人参中一个最重要的有效成分(人参属五加科中一属),能减少大鼠暂时性脑缺血梗塞面积和改善神经功能缺失症状,这种神经保护作用的机制不完全清楚。本实验研究GRb1的神经保护作用是否与防止神经元凋亡和调控神经元凋亡抑制蛋白(NAIP)的表达有关。通过阻塞大鼠大脑中动脉建立局灶性脑缺血模型,再灌注开始后立即给予腹腔注射GRb1(40mg/kg)。具有神经功能缺失的大鼠被随机分成2组:缺血组和GRb1组,每个组根据再灌注时间(3h,12h,1d,2d,3d,5d,10d,n=4/每时间点)分为亚组。正常大鼠和假手术组做为对照组。TUNEL标记分析凋亡细胞,用免疫组织化学的方法检测NAIP的表达。结果显示再灌注3h凋亡细胞数量开始升高,24h达高峰,后下降,但再灌注10d的凋亡细胞数量显著高于对照组(P<0.01)。与缺血组相比,GRb1各亚组的凋亡细胞数减少,但再灌注12h至3d,其差异具有统计学意义。在对照组,NAIP弱或阴性的免疫反应广泛出现在脑实质神经元。再灌注3h,NAIP阳性细胞增加,12h时达高峰,后下降。再灌注5d,NAIP阳性细胞数量比对照组少(P<0.05)。NAIP阳性神经元出现缺血性改变如扇形或三角形,纹状体星形胶质细胞强表达NAIP。在GRb1组,NAIP阳性细胞数量从再灌注12h到10d,显著高于缺血组。本实验结果提示大鼠局灶性脑缺血时,GRb1能减少细胞凋亡,其机制可能与增加NAIP的表达有关。     

Increased cyclin D3 expression significantly correlates with p27 nuclear positivity in gastrointestinal stromal tumors

Gastrointestinal stromal tumors, the most common mesenchymal tumors of the gastrointestinal tract, are characterized by strong expression of c-Kit protein. Recently, it has been shown that gastrointestinal stromal tumors may also contain alterations of genes involved in the regulation of cell cycle. In this study, we evaluate the prevalence and clinical significance of cyclin D1 and D3, Ki-67, p27, and retinoblastoma protein expression in a group of 50 human gastrointestinal stromal tumors selected from the files of the Moffitt Cancer Center. Tissue sections from each case were subjected to immunostaining using the avidin-biotin complex method. Cyclin D1 nuclear positivity was detected in 21 of 50 (42%) and cyclin D3 in 24 of 50 (48%) cases. p27 high immunoreactivity and negative or decreased retinoblastoma protein expression were identified in 33 of 50 (66%) gastrointestinal stromal tumors. In 19 of 50 (38%) tumors, Ki-67 had high labeling index. Direct correlation was observed between cyclin D3 and p27 expression (P < .0001), and between cyclin D1 and retinoblastoma protein (P = .03). Coexpression of cyclin D3 and p27 was demonstrated by immunofluorescence. The p27 protein expression inversely correlated with tumor size (P = .004), but was not correlated with tumor grade (P = .12). Ki-67 directly correlated with both tumor size (P = .03) and tumor grade (P = .008). We report a direct correlation between cyclin D3 and p27 expression in gastrointestinal stromal tumors. Additional alterations in cyclin D1, Ki-67, and retinoblastoma protein expression indicate a disregulated cell cycle in these tumors.     

Cytogenetics of a new cytotype of African Mus (subgenus Nannomys) minutoides (Rodentia, Muridae) from Kenya: C- and G- banding and distribution of (TTAGGG) n telomeric sequences

We present the results of a cytogenetic study on Mus (Nannomys) minutoides from Kenya by means of C- and G- banding and in-situ fluorescence hybridization (FISH) to localize the telomeric sequences. The karyotype is characterized by the occurrence of several Rb chromosomes Rb(1.X), Rb(1.Y). Rb(2.17), Rb(3.13), Rb(4.10), Rb(5.11), Rb(6.7), Rb(8.12), not previously described for this species. This finding suggests a high level of chromosomal diversification, which means it is possible to consider this cytotype as a new, well-differentiated, chromosomal lineage within the subgenus. The C-banding of the metaphases illustrated conspicuous blocks of centromeric heterochromatin at the paracentromeric regions of all telocentric chromosomes. Centromeric heterochromatin is not visible on all biarmed chromosomes. Following hybridization with telomeric probes, bright interstitial telomeric sequence (ITS) fluorescence signals are evident at the pericentromeric area of all Rb chromosomes, with the exception of Rb(2.17). Considering the localization of the C-positive heterochromatin and of the telomeric sequences, the events leading to the Kenyan cytotype from an all-telocentric condition probably included two steps: first, fusion without loss of heterochromatin and pericentromeric telomeric sequences; second, the reduction of the C-positive satellite DNA followed by the amplification of telomeric sequences in the C-negative paracentromeric region of Rb chromosomes. The presence of a single Rb(2.17) without ITS indicates possible variations of this mechanism.     

高效液相色谱法测定三七伤药片中3组分的含量

目的建立以高效液相色谱法测定三七伤药片中三七皂苷R1和人参皂苷Rg1、Rb1含量的方法。方法色谱柱为VP-ODS(150mm×4.6mm,5μm),使用梯度洗脱系统,流动相为乙腈-水(0~20min(20∶80),20~26min(40∶60),26~35min(20∶80)),流速为1.0mL.min-1,柱温为室温,检测波长为203nm。结果三七皂苷R1的线性范围为0.261~7.83μg(r=0.9999),平均回收率为(101.12±2.03)%(RSD=2.1%);人参皂苷Rg1的线性范围为0.6025~18.075μg(r=0.9997),平均回收率为(97.22±3.33)%(RSD=1.9%);人参皂苷Rb1的线性范围为0.5375~16.125μg(r=0.9996),平均回收率为(100.71±2.4)%(RSD=1.6%)。结论该法可用于测定三七伤药片中三七皂苷R1、人参皂苷Rg1、Rb1的含量。     

高效液相色谱法同时测定姜参胶囊中人参皂苷Rg_1、Re的含量

目的:建立以高效液相色谱法同时测定姜参胶囊中人参皂苷Rg1、Re含量的方法。方法:色谱柱为Kromasil C18,流动相为乙腈-0.05%磷酸溶液(21∶79),检测波长为203nm,流速为1.0mL.min-1。结果:人参皂苷Rg1、Re进样量分别在0.502~4.016μg(r=0.9997)、1.090~8.720μg范围内呈良好的线性关系(r=0.9998);平均回收率分别为98.8%(RSD=1.24%)、99.4%(RSD=1.68%)。结论:本法操作简便、快速、准确可靠,可用于姜参胶囊的质量控制。     

HPLC测定复方血栓通滴丸中人参皂苷Rg1的含量

目的建立复方血栓通滴丸中人参皂苷Rg1的含量测定方法。方法采用C18（10μm，250mm×4．6mm）柱，流动相为乙腈-0．05％磷酸溶液（21：79），流速：1．5ml／min，检测波长：203nm。结果人参皂苷Rg1在3．2～32μg线性关系良好，平均回收率人参皂苷Rg1为96．58％，RSD为2．11％。结论本法操作简便，结果稳定，重现性好，可作为质量控制方法。     

The protective effects of ginsenosides on human erythrocytes against hemin-induced hemolysis.

Panax ginseng has been used in traditional Chinese medicine to enhance stamina and capacity to deal with fatigue and physical stress. Many reports have been devoted to the effects of ginsenosides on many in vitro or in vivo experimental systems. The major aim of this work is to investigate the protective effects of 12 individual ginsenosides including Rb1, Rb3, Rc, Rd, Re, Rg1, Rg2, Rg3, Rh1, Rh2, R1 and pseudoginsenoside F11, together with the central structures of aforementioned ginsenosides, 20(S)-protopanaxadiol (PD) and 20(S)-protopanaxatriol (PT), on hemin-induced hemolysis of human erythrocytes. This is because hemin can induce hemolysis by accelerating the potassium leakage, dissociating skeletal proteins and prohibiting some enzymes in the membrane of erythrocyte. Thus, the structure-activity-relationship (SAR) between ginsenosides and protective effects has been screened in this in vitro experimental system. It is found that Rh2 and Rg3 intensify hemolysis in the presence of hemin, and initiate hemolysis even in the absence of hemin. All the other ginsenosides protect human erythrocytes against hemin-induced hemolysis more or less. The overall sequence is Rc>Rd>Re approximately Rb1>Rg1 approximately Rh1>Rb3 approximately Rg2 approximately R1 approximately F11 approximately PT. In addition, the protective effects of PD and PT have been detected, and found that PD promotes hemolysis appreciably, whereas PT protects erythrocytes efficiently. Moreover, the protective effects of PT ginsenosides are similar to PT itself, and the protective effects of PD ginsenosides vary remarkably, demonstrating that the positions of the sugar moieties make the protective activities of ginsenosides complicated. Especially, sugar moiety at 20-position is critical for PD ginsenosides to inhibit hemolysis, whereas hydroxyl group at 3-position is important for PT ginsenosides. The present result may be useful for understanding the SAR of ginsenosides.     

Tumor suppressor genes: new pathways in gynecological cancer

The Retinoblastoma (Rb-1) and p53 genes appear to play an important role in controlling cell division, and mutations in Rb-1 and p53 have been reported widely in non-gynecological cancers. Unlike other cancer-related genes, which become activated during carcinogenesis, it is the loss of wild type p53 and Retinoblastoma protein (RB) function that is thought to contribute to cancer development. These genes therefore, have been called tumor suppressor genes since normal function appears to be necessary for negative control of cell growth. Several viral oncoproteins have been shown to interact with RB and p53. It seems likely that the formation of these complexes inactivates the cellular protein resulting in an overall effect similar to somatic mutation of the Rb-1 or p53 genes. The HPV16 transforming proteins E7 and E6 complex with protein products of Rb-1 and p53, respectively. In HPV positive anal and cervical tumors the normal function of RB and p53 may be inhibited by these viral proteins and so mutation within the RB-1 and p53 gene coding sequences would not appear to be a necessary step in the genesis of these tumors. However, in HPV negative tumors from the same tissues, loss of wild type Rb-1 and p53 activity may only be achieved by somatic mutation of these genes.     

Ginseng and ginsenoside Rg3, a newly identified active ingredient of ginseng, modulate Ca2+ channel currents in rat sensory neurons

There is increasing evidence that ginseng influences pain modulation. In spite of extensive behavior studies, the detailed mechanism of ginseng actions at the cellular level and the identity of the active substance have not been elucidated yet. Whole-cell patch-clamp recordings were used to examine the modulation of high-voltage-activated Ca2+ channel currents by ginseng total saponins and its various individual ginsenosides in rat dorsal root ganglion neurons. Application of ginseng total saponins suppressed Ca2+ channel currents in a dose-dependent manner. Occlusion experiments using selective blockers revealed that ginseng total saponins could modulate L-, N-, and P-type currents. The co-application of ginseng total saponins and the gamma-opioid receptor agonist, D-Ala(2), N-MePhe(4), Gly(5)-ol-enkephalin (DAMGO), produced non-additive effects in most cells tested and each effect was significantly relieved by a depolarizing prepulse. Overnight treatment of cells with pertussis toxin profoundly reduced the inhibition. Furthermore, we now report that ginsenoside Rg3, among the major fractions of ginseng saponins, is a newly identified active component for the inhibition. These results suggest that the modulation of Ca2+ channels by ginseng total saponins, in particular by ginsenoside Rg3, could be part of the pharmacological basis of ginseng-mediated antinociception.     

Neuroprotective effects of ginseng total saponin and ginsenosides Rb1 and Rg1 on spinal cord neurons in vitro

Spinal cord injury is a major cause of disability and results in many serious physical, psychological, and social difficulties. Numerous studies have shown that traumatic spinal cord injuries (SCI) lead to neuronal loss and axonal degeneration in and around the injury site that cause partial disability or complete paralysis. An important strategy in the treatment of SCI is to promote neuron survival and axon outgrowth, making possible the recovery of neural connections. Using an in vitro survival assay, we have identified ginsenosides Rb1 and Rg1, extracted from ginseng root (Panax ginseng C. A. Meyer), as efficient neuroprotective agents for spinal cord neurons. These compounds protect spinal neurons from excitotoxicity induced by glutamate and kainic acid, as well as oxidative stress induced by H(2)O(2). The neuroprotective effects are dose-dependent. The optimal doses are 20-40 microM for ginsenosides Rb1 and Rg1. The effects are specific for Rb1 and Rg1, since a third ginsenoside, Re, did not exhibit any activity. Ginseng has been used for thousands of years in the treatment of neurological disorders and other diseases in Asia. Ginsenosides Rb1 and Rg1 represent potentially effective therapeutic agents for spinal cord injuries.