Changes in the level of acetylcholinesterase of Nematospiroides dubius and Trichostrongylus colubriformis following paralysis by levamisole in vivo

Acetylcholinesterase (acetylcholine acetylhydrolase; EC 3.1.1.7) levels of Nematospiroides dubius from laboratory mice and Trichostrongylus colubriformis from lambs have been measured. The anthelmintic levamisole (leavo isomer of 2,3,5,6-tetrahydro-6-phenylimidazo-(2,1b)-thiazole (Tetramizole)) did not affect the level of acetylcholinesterase in N. dubius in vivo but caused a reduction in the level of the enzyme in T. colubriformis following paralysis in vivo. The effect of levamisole on acetylcholinesterase in the nematodes is explained in terms of the differing roles of the enzyme in these two species.     

Radio-chemo-immunotherapy (CCNU plus Levamisole) for treatment of metastatic brain tumors

Summary Thirty-one patients with metastatic brain tumors were treated with Radiotherapy (RT) and CCNU or with RT, CCNU and Levamisole (LMS) in a randomized clinical trial. Twenty-seven were evaluable. All patients were submitted to whole brain radiation (50 ± 5 Gy) and CCNU (130 mg/ m² p. o. every 8 weeks). 15 also received Levamisole (2.5 mg/ kg p.o. daily for 3 weeks in the first month, for 2 weeks in the second, and then once a week monthly until progression). Primary tumor was predominantly lung cancer (22/27) and brain lesions were generally multiple (24/27). The overall response rate was 35% in the RT plus CCNU treated group and 38% in the RT plus CCNU plus LMS treated group. The median survival time was similar and not statistically different in both groups (7 versus 6 months). No important side effects were observed either in the RT + CCNU or in the RT + CCNU + LMS treated groups. The absence of combined depression of T-cell levels and responsiveness of lymphocytes to mitogens suggests that thymus dependent immunity could be improved by LMS administration. However, such improvement had no impact on duration of survival in patients with metastatic brain tumors.     

Kinetics of β-glycerophosphate-induced endochondral mineralization In vitro. Calcium accumulation,alkaline phosphatase activity,and effects of levamisole

Summary Isolated mesenchymal limb bud cells from day-12 mouse embryos grown at high density in organoid culture at the medium/air interphase differentiate into chondrocytes and form cartilage nodules. Upon addition of -glycerophosphate (-GP), cartilage undergoes endochondral mineralization. This -GP-induced mineralization was investigated by measuring the calcium content in the cultures and the activity of alkaline phosphatase (AP) in the cell mass and the medium. Calcium incorporation depended on the amount of -GP added. After continuous treatment, mineralization began on day 8 of the culture period and increased linearly until day 15. In long-term cultures, periodical treatment for 6 days caused an increase in mineralization the older the cultures were, but the slope of increase was proportionately less steep. Treatment at the latest period on days 19–24 resulted in a markedly reduced mineralization. After short-term treatment (48 hours), mineralization increased also the older the cultures were and proceeded during further cultivation in -GP-free medium. This kinetic behavior indicates a dependency of mineralization on cartilage maturation in this in vitro system. AP activity increased enormously and nearly logarithmically in the cell mass in -GP-free medium, whereas -GP treatment inhibited this drastic increase. In the medium, considerable activities of AP were also measurable from day 10 onward. It increased in -GP-free medium up to day 14, but was diminished after mineralization had been induced. Levamisole inhibited AP activity dose dependently when added directly to the enzyme-containing medium (100% inhibition at 10^-3 M). Added to the cultures from day 7 to 14, it partially inhibited AP activity and mineralization at 5×10^-5 M; mineralization was totally inhibited at 10^-3 M, but AP activity was still present. This high concentration was cytotoxic, as revealed ultrastructurally and by GAG estimation. This in vitro system comprises cartilage development and maturation, -GP-inducible endochondral mineralization, and final degenerative changes; it may be an appropriate model for investigations on endochondral mineralization.     

A phase I study of 5-fluorouracil, leucovorin and levamisole

 Purpose: The activity of 5-fluorouracil (5-FU) against colon cancer is enhanced by leucovorin and the combination of 5-FU and levamisole has activity in the adjuvant treatment of colonic malignancies. The combination of 5-FU with both leucovorin and levamisole may provide additional benefit in the treatment of colon cancer. Methods: A phase I study to assess qualitative and quantitative toxicities of this three-drug combination and to determine a dose for further phase II testing was undertaken. The role of levamisole as an immunomodulator was also assessed. Results: A group of 38 patients with incurable etastatic malignancies received 119 cycles of treatment at eight dose levels. 5-FU (375 mg/m² per day) and leucovorin (200 mg/m² per day) were administered intravenously (days 1–5). Levamisole was administered orally (days 1–3 and 15–17) at doses from 30 to 470 mg/m² per day. Patients received both 5FU/leucovorin and 5-FU/leucovorin/levamisole in random order for their initial two cycles. All subsequent treatments were with the three-drug combination. Toxicities included nausea, vomiting, stomatitis, thrombocytopenia and granulocytopenia. Diarrhea was the dose-limiting toxicity at 470 mg/m² per day levamisole. The addition of levamisole resulted in more toxicity than 5-FU and leucovorin alone. No clinical responses were seen with this regimen. The addition of levamisole resulted in more immunomodulation than 5-FU and leucovorin alone as evidenced by release of neopterin from monocytes. Conclusion: With this schedule and dose of 5-FU and leucovorin, the maximum tolerated dose of levamisole was 354 mg/m². However, given the lack of response and the absence of dose-dependent immunomodulation, this may not be the appropriate dose for further phase 11 studies. Received: 20 October 1995 / Accepted: 16 June 1996     

左旋咪唑对细粒棘球蚴感染小鼠不同时期T细胞亚群的影响

目的探讨左旋咪唑（LMS）对细粒棘球蚴感染鼠的免疫调节作用和对病程转归的影响。方法昆明种小鼠腹腔接种细粒棘球蚴，建立感染动物模型。在感染后2、4、8、12、16、20周，未治疗组和实验组分别给予生理盐水和左旋咪唑（25mg／kg），连续7d，测定各组小鼠脾指数、胸腺指数及囊重，运用流式细胞术（FCM）测定小鼠脾CD4^＋和CD8^＋T细胞百分率及CD4^＋／CD8^＋比值的动态变化。另设8只未接种小鼠为健康对照。结果生理盐水组小鼠感染2周时CD4^＋、CD8^＋T细胞百分率显著高于健康对照组（P〈0．01）），随后CD4^＋T细胞的百分率逐渐降低，CD8^＋T细胞的百分率逐渐增高，至感染后16周和20周，CD4^＋T细胞、CD8^＋T细胞的百分率及CD4^＋／CD8^＋比值与健康对照组比较差异仍具有显著性（P〈0．01）。与生理盐水组小鼠相比，左旋咪唑组小鼠在感染2周时CD4^＋、CD8^＋T细胞的百分率明显增高，与健康组小鼠相比有统计学意义（P〈0．01）；在感染16周和20周时脾指数升高，CD4^＋T细胞百分率上升，CD8^＋T细胞的百分率下降，CD4^＋／CD8^＋比值升高，平均囊重下降，与生理盐水组比较差异均有显著性（P〈0．01）。结论左旋咪唑对细粒棘球蚴感染小鼠有免疫调节作用，在感染后期可升高小鼠脾指数，使CD4^＋T细胞及CD8^＋T细胞比例恢复正常，机体的细胞免疫功能增强，从而减缓细粒棘球蚴的增殖。     

Strategic use of moxidectin or closantel in combination with levamisole in the control of nematodes of sheep in the highlands of central Kenya

The strategic use of moxidectin or closantel in combination with levamisole (LEV) to control gastrointestinal nematodes of sheep in the highlands of central Kenya was examined. Thirty Corriedale female lambs aged between 6 and 8 months were assigned to three treatment groups of ten lambs each. The three groups of lambs were set stocked on separate paddocks for the entire study period of 12 months. Lambs in Group 1 were dewormed strategically with moxidectin at 0.2 mg/kg body weight and those in Group 2 with closantel at 10 mg/kg body weight together with LEV at 7.5 mg/kg body weight. These strategic treatments were given 3 weeks after the onset of both the short and long rains and at the end of the long rainy season. The third group of lambs remained untreated (control group). Nematode infections in the treated groups of lambs and larval infectivity for the pastures on which the lambs were grazing were well controlled compared with the untreated control group. This resulted in higher weight gains and packed cell volume (PCV) in the treated lambs compared with the untreated lambs. These parameters were comparable between the lambs treated with moxidectin and those treated with closantel plus LEV. The estimated monitory benefit per animal from the control of gastrointestinal nematodes using moxidectin or closantel in combination with LEV when compared with animals in the control group were US dollars 26 and 25, respectively. It was concluded that worm control strategies for sheep in the study area, which are based on anthelmintic treatments during the rainy seasons, are effective. Due to the extended period during which pastures remain infective in the high rainfall central highlands of Kenya, anthelmintics with sustained action such as moxidectin or closantel may be most effective. On farms where resistance to the commonly used benzimidazoles or LEV groups of anthelmintics has developed, moxidectin or closantel may be used in helminth control programs for sheep.     

Anti-proliferative effect of levamisole on human myeloma cell lines in vitro

Levamisole has been employed as an immunomodulatory agent in conjunction with 5-fluorouracil in the treatment of colon cancer relapse. At high doses, levamisole has been shown to have both anti-cancer and immunosuppressive activities. In vitro, levamisole has been shown to potentiate the anti-proliferative effect of 5-fluorouracil in several types of tumor cell lines; however, its mechanism of cytotoxic action and its molecular targets in cells remains to be elucidated. Here, the effect of levamisole on the proliferative response of the human multiple myeloma cell lines RPMI 8226 and U266B1 was studied in vitro. Treatment of both lines with varying concentrations of levamisole for 48 and 72?h in culture resulted in a significant inhibition of proliferation (unstimulated) in a dose-dependent manner, as assessed by an 3-[(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide dye assay. Furthermore, measurements of cell viability (using a trypan blue dye exclusion assay) clearly showed that the levamisole was cytotoxic. The preliminary evaluation of the mechanism of this cytotoxic effect revealed that this drug induced apoptosis in the myeloma cells, as evidenced by increases in the levels of DNA fragmentation, release of cytochrome c into the cytoplasm, and the activation of caspase-3 activity in the cells. The results of these studies strongly suggest that levamisole could be a potent anti-myeloma agent and might be considered in the treatment of multiple myeloma in the future.     

孕期干预阻断乙肝病毒母婴垂直传播效果评价

目的　探讨孕期干预治疗阻断乙型肝炎病毒母婴垂直传播的效果。方法　将 6 0例 HBs Ag/ HBe Ag阳性孕妇分成治疗组 31例 ,对照组 2 9例。治疗组均在孕 2 6周起开始注射乙肝免疫球蛋白 (HBIG)及外用左旋咪唑涂布剂 ,采用 EL ISA法检测孕妇和新生儿血清 HBs Ag、HBAb、Hbe Ag、HBe Ab、HBc Ab,用 PCR电泳和 RT-PCR法测定 HBV- DNA及全长型和顿挫性转录体。分析母婴之间乙肝病毒分子水平上的关系。结果　新生儿外周血中 HBs Ag阳性者 2例 ,宫内感染率为 6 .4 5 %。对照组 4例 ,宫内感染率 13.7%。与对照组比较差异有显著性。 (P<0 .0 1) ,两组都有超过一半的患儿携带顿挫型病毒转录体。结论　携带 HBV孕妇于孕晚期给 HBIG和左旋咪唑涂布剂联合治疗后 ,可有效降低婴儿 HBs Ag和 HBV- DNA携带率     

GC法测定盐酸左旋咪唑片的含量

目的:建立GC法测定盐酸左旋咪唑片中盐酸左旋咪唑的含量。方法:毛细管气相色谱法,以联苯胺为内标。结果:线性范围0.5～2.5mg/ml;r=0.9991。回收率为99.4%,RSD=0.74%。结论:方法简便,精确,重现性好,可很好地控制盐酸左旋咪唑的内在质量。