Retinal changes induced by treatment with vincristine and vinblastine

The mitosis-inhibiting Vinca-alkaloids vincristine sulphate and vinblastine sulphate were injected into the vitreous body. This treatment resulted in ultrastructural changes in the retina within an hour. The retinal nerve cells showed a marked increase in the number of cell organelles, including the 100 Å filaments found in their perikarya. The microtubules disappeared and crystalloid structures appeared within an hour. The axons became distended by accumulated cell organelles, usually surrounding a crystalloid. The synaptic bodies, especially the presynaptic ones, often contained crystalloids, and showed a transient increase in the number of synaptic vesicles. The inner segments of the photoreceptor cells showed similar ultrastructural alterations, and, in addition, stacks of membranous structures. The outer segments decreased in length, and only rudiments of these structures remained one week after the intravitreal injection. The non-pigmented epithelial cells and the Müller's neuroglial cells also showed marked structural alterations.These ultrastructural changes are consistent with the biochemical and fluorescence microscopic observations that vincristine and vinblastine both inhibit the intracellular flow of cell constituents, as previously demonstrated to be the case with colchicine. It is proposed that the structural changes in the individual cells reflect the drug-induced imbalance between the inhibited intracellular transport and the continued formation of the cell constituents characteristic of the afflicted cell.This study was supported by grants from M. Bergwalls Stiftelse, W. and M. Lundgrens Stiftelse, H. Hiertas Stiftelse, Swedish Medical Research Council (B 72-12 X-2543-04 A) and the Swedish National Cancer Society (265 - B 70-02 X).     

均匀设计法优化长春碱分子印迹聚合物的制备工艺

目的:优化长春碱分子印迹聚合物的制备工艺。方法:采用均匀设计法,考察因素包括功能单体甲基丙烯酸(MAA)的用量、交联剂乙二醇二甲基丙烯酸酯(EDMA)的用量以及致孔剂(溶剂),评价指标为对模板分子长春碱(VLB)的吸附率。结果:当VLB用量为0.1 mmol时,MAA和EDMA的用量分别为0.4 mmol、1.6 mmol,致孔剂为乙腈,在此条件下制备的长春碱分子印迹聚合物,对长春碱的吸附率为88.20%。并采用红外光谱、扫描电镜对聚合物结构进行表征。结论:用均匀设计法优化聚合反应的过程参数,方法可行,结果可靠,制备的聚合物对模板分子VLB表现出特异的亲和性。     

长春花中长春碱含量测定方法的研究

研究了薄层扫描法及薄层－紫外分光光度法测定长春花中长春碱含量的两种方法,在硅胶Ｆ２５４－ＣＭＣ－Ｎａ碱性板上（ＮａＯＨ浓度为０．１ｍｏｌ／Ｌ）,以氯仿－甲醇－石油醚（９：１：５）为展开剂,分离了长春花提取液中长春碱和长春新碱等１４种成分。前法采用双波长薄层扫描,λｓ＝２８０ｎｍ,λＲ＝３５０ｎｍ,线性范围在２￣１０μｇ。后法采用薄层分离后,样品带用甲醇洗脱后,紫外分光光度法测定含量。后法在５￣２５     

Influence of vinblastine on DNA parameters and multidrug resistance in renal cell carcinoma in vitro

The purpose of this study was to investigate how the vinca alkaloid vinblastine influences DNA parameters and the mechanisms of multidrug resistance in renal cell carcinoma. After exposing cell cultures of human renal carcinoma to progressively increasing concentrations of vinblastine the cell lines were examined by flow cytometric DNA analysis to assess the S-phase and G₂/M-phase fraction and by a modified MTT assay. It was shown that the exposed cells became P-glycoprotein-positive by staining the cells with a monoclonal antibody (JSB-1). The flow cytometric analysis revealed, with prolonged vinblastine exposure, correlated increases in the S-phase and G₂/M-phase fractions (P = 0.0001). When vinblastine-free medium was used for culturing, the changed DNA characteristics returned to their original values. Comparing the DNA parameters with the IC₅₀ (concentration when cell growth is inhibited by 50%) we found a strong correlation between these parameters (P = 0.0001). In conclusion, DNA analysis of long-term vinblastine exposure may provide insight into events leading to multidrug resistance. Furthermore, analysis of the DNA profile might also be an important investigation before planning therapy with vinblastine for renal cell carcinoma. Received: 24 January 1997 / Accepted: 18 September 1997     

Long-term memory: disruption by inhibitors of protein synthesis and cytoplasmic flow

Colchicine (60 micrograms/kg), an inhibitor of axoplasmic transport, administered subcutaneously to mice had no detectable effect on retention when given shortly after active avoidance training, nor did a pretraining injection of anisomycin (ANI) have an amnesic effect. However, when ANI was administered shortly prior to training and colchicine was administered after training, retention performance was impaired. The amnesic effect was dependent on the time at which colchicine was administered. The amnesic effect was also obtained when ANI was combined with either vinblastine (6 micrograms/kg) or podophyllotoxin (3 micrograms/kg), drugs that inhibit axoplasmic transport. Intracerebral injections of colchicine (60 ng to 60 pg) caused amnesia in subjects pretreated with ANI, but not in subjects pretreated with saline. Lumicolchicine, an isomer of colchicine, which has similar central nervous system effects but has a low binding affinity for microtubule protein, did not impair retention in ANI pretreated mice. It is suggested that axonal transport of recently synthesized protein is required for long-term memory storage.     

Effect of inhibition of dynein function and microtubule-altering drugs on AAV2 transduction

Over the past decade, adeno-associated (AAV) virus has emerged as an important vector for gene therapy. As a result, understanding its basic biology, including intracellular trafficking, has become increasingly important. Here, we describe the effect of inhibiting dynein function or altering the state of microtubule polymerization on rAAV2 transduction. Overexpression of dynamitin, resulting in a functional inhibition of the minus-end-directed microtubule motor protein dynein, did not inhibit transduction. Equally, treatment of cells with nocodazole, or concentrations of vinblastine that result in the disruption of microtubules, had no significant effect on transduction. In contrast, high concentrations of Taxol and vinblastine, resulting in microtubule stabilization and the formation of tubulin paracrystals respectively, reduced rAAV2 transduction in a vector-dose-dependent manner. These results demonstrate that AAV2 can infect HeLa cells independently of dynein function or an intact microtubule network.     

Role of target and effector cell structures in natural killer-mediated cytotoxicity

Summary An analysis of target and effector cell structures involved in thein vitro natural killer (NK)-mediated cytotoxicity has been performed. The degree of surface expression of transferrin receptor (TR) was only in part correlated with that of cell lysis. Moreover, the lysis could not be blocked by treating target cells with two anti-TR monoclonal antibodies. Finally, cell lines poorly affected by NK cells express TR only at the cytoplasmic level. As to the effector cells, the integrity of cytoskeleton components (especially microtubules) was found to be essential for the occurrence of cell lysis. In fact, vinblastine, an anti-microtubule agent, was able to significantly reduce the percentage cell lysis. This effect was not due to a selective depletion in NK cells induced by the drug. It is concluded that the mechanisms underlying NK activity are complex and involve both target and effector cell structures. This work was supported by a grant from theConsiglio Nazionale delle Ricerche (CNR), Roma, Italy,Progetto Finalizzato ‘Oncologia’ (contract n№ 85.02190.44).     

Salvage chemotherapy for non Hodgkin's lymphoma of unfavourable histology with a combination of CCNU and vinblastine

Twenty patients with relapsed or refractory, intermediate or high grade non Hodgkin's lymphoma were treated with a combination of CCNU and vinblastine. Complete responses occurred in four patients (20 per cent), partial responses in eight (40 per cent), for an overall response rate of 60 per cent. The regimen was more effective in patients with high grade lymphoma, absence of constitutional symptoms, better response to prior treatment. Duration of response was 4, 8, 16, 30 months for complete responders; 2, 2, 6, 6, 6, 8, 9, 14 months for partial responders. This combination regimen seems at least as effective as most of other regimens utilized in salvage treatment of non Hodgkin's lymphomas, with a very acceptable toxicity.     

Non-AIDS-related Kaposi's sarcoma: A single-institution experience

AIM: To evaluate the outcomes and potential prognostic factors in patients with non-acquired immunodeficiency syndrome (AIDS)-related Kaposi’s sarcoma (KS).METHODS: Patients with histologically proven non-AIDS-related KS treated with systemic chemotherapy were included in this retrospective analysis. In some cases, the human herpes virus 8 status was assessed by immunohistochemistry. The patients were staged according to the Mediterranean KS staging system. A multivariable model was constructed using a forward stepwise selection procedure. A P value < 0.05 was considered statistically significant, and all tests were two-sided.RESULTS: Thirty-two cases were included in this analysis. The average age at diagnosis was 70 years, with a male/female ratio of approximately 2:1. Eighty-four percent of the cases had classic KS. All patients received systemic chemotherapy containing one of the following agents: vinca alkaloid, taxane, and pegylated liposomal doxorubicin. Ten patients (31.5%) experienced a partial response, and a complete response was achieved in four patients (12.4%) and stable disease in sixteen cases (50%). Two patients (6.2%) were refractory to the systemic treatment. The median progression-free survival (PFS) was 11.7 mo, whereas the median overall survival was 28.5 mo. At multivariate analysis, the presence of nodular lesions (vs macular lesions only) was significantly related to a lower PFS (hazard ratio: 3.09; 95%CI: 1.18-8.13, P = 0.0133).CONCLUSION: Non-AIDS-related KS appears mostly limited to the skin and is well-responsive to systemic therapies. Our data show that nodular lesions may be associated with a shorter PFS in patients receiving chemotherapy.     

Isolation and Characterization of Antineoplastic Alkaloids from Catharanthus Roseus L. Don. Cultivated in Egypt

Vinblastine and vincristine (the antileukemic agents) were isolated, in a pure form, from Catharanthus roseus L. Don., cultivated in Egypt, by several chromatographic techniques. Five modified methods for the preparation of total alkaloids were carried out. All the isolated mixtures were evaluated by HPLC and HPTLC analyses. The antineoplastic alkaloids; vinblastine and vincristine, were isolated by the use of vacuum liquid chromatographic column on silica gel : aluminium oxide (1:1) mixed bed vacuum liquid chromatography (VLC), Charcoal column, and finally purified by centrifugally accelerated radial chromatography (Chromatotrone).