Modulation of cyclophosphamide activity by O 6-alkylguanine-DNA alkyltransferase

Purpose: The human medulloblastoma cell line D283 Med (4-HCR), a line resistant to 4-hydroperoxycyclophosphamide (4-HC), displays enhanced␣repair of DNA interstrand crosslinks induced by phosphoramide mustard. D283 Med (4-HCR) cells are cross-resistant to 1,3-bis(2-chloroethyl)-1-nitrosourea, but partial sensitivity is restored after elevated levels of O ⁶-alkylguanine-DNA alkyltransferase (AGT) are depleted by O ⁶-benzylguanine (O ⁶-BG). Studies were conducted to define the activity of 4-HC and 4-hydroperoxydidechlorocyclophosphamide against D283 Med (4-HCR) after AGT is depleted by O ⁶-BG. Methods: Limiting dilution and xenograft studies were conducted to define the activity of 4-HC and 4-hydroperoxydidechlorocyclophosphamide with or without O ⁶-BG. Results: The activity of 4-HC and 4-hydroperoxydidechlorocyclophosphamide against D283 Med (4-HCR) was increased after AGT depletion by O ⁶-BG preincubation. Similar studies with Chinese hamster ovary cells, with or without stable transfection with a plasmid expressing the human AGT protein, revealed that the AGT-expressing cells were significantly less sensitive to 4-HC and 4-hydroperoxydidechlorocyclophosphamide. Reaction of DNA with 4-HC, phosphoramide mustard, or acrolein revealed that only 4-HC and acrolein caused a decrease in AGT levels. Conclusions: We propose that a small but potentially significant part of the cellular toxicity of cyclophosphamide in these cells is due to acrolein, and that this toxicity is abrogated by removal of the acrolein adduct from DNA by AGT. Received: 17 February 1998 / Accepted: 20 May 1998     

应用消减免疫法初步合成抗人肝癌cDNA

目的　筛选抗人肝癌小鼠脾细胞库,初步合成ｃＤＮＡ。方法　利用消减免疫法以三株肝癌细胞系免疫Ｂａｌｂ／ｃ小鼠,免疫组化法检测免疫小鼠血清与正常成人肝组织、肝癌组织的反应性,在此基础上进一步合成抗人肝癌ｃＤＮＡ。结果　免疫小鼠未与正常肝组织发生反应,而肝癌组织染色明显;由筛选小鼠脾细胞库初步合成了抗人肝癌ｃＤＮＡ。结论　应用此法免疫初步筛选了较好的抗人肝癌脾细胞库,为以后的实验研究奠定了良好的基础。     

Aortico-pulmonary paraganglioma showing remarkable regression with cyclophosphamide

The treatment of choice for mediastinal paraganglioma is complete surgical resection. Its local recurrence, however, is very difficult to treat surgically because it usually involves important structures of the mediastinum, such as the aorta and trachea. We report a 64-year-old woman with aortico-pulmonary paraganglioma who developed local recurrence after complete resection. The recurrent tumor responded dramatically to single-agent chemotherapy with cyclophosphamide, whereas it did not respond to radiotherapy or combination chemotherapy with mitomycin C, vindesine, and cisplatin. We therefore consider that single-agent chemotherapy with cyclophosphamide could be an alternative treatment for unresectable recurrent paraganglioma. Received: November 21, 1997 / Accepted: March 18, 1999     

Effect of Oral Vs. Parenteral Cyclophosphamide on In Vitro Iga and Igg Production by Murine Peyer's Patches and Cultured Jejunal Fragments

The gut associated lymphoid tissue plays an important role in intestinal defenses, food allergy, oral tolerance, and certain intestinal diseases. This study describes the effect of either oral or parenteral cyclophosphamide on IgA and IgG production in the gut. Mice were treated with cyclophosphamide either IV or PO, and Peyer's patch cell cultures were established to evaluate mitogen induced production of IgA and IgG. To evaluate the effect of cyclophosphamide on the plasma cell rich lamina propria, segments of jejunum were cultured and overnight secretion of IgG and IgA were measured. We found, the secretion of IgA or IgG by jejunal fragments was not influenced by cyclophosphamide (IV or PO). Mitogen induced secretion of IgA and IgG by Peyer's patch cells was markedly decreased 24 hrs after drug administration, with significant recovery by day 7. Cell mixing experiments revealed that a single dose cyclophosphamide reduced the capacity of Peyer's patch B cells to secrete IgA or IgG when co cultured with normal T cells. This study demonstrates that a single dose cyclophosphamide can have profound effects on the gut immune system and that the drug has a similar effect when given either orally or parenterally.     

难治性肾病综合征环磷酰胺两种治疗方案疗效对比

为了比较环磷酰胺（CTX）大剂量冲击疗法和隔日小剂量连续给药法对难治性肾病综合征（NS）的疗效，我们对90例成人难治性NS按两种不同方案给予治疗。结果表明：两种方案治疗均能使病人24h尿蛋白量降低、血清白蛋白值升高，以CTX冲击治疗组变化更明显（P＜0．01）；冲击治疗组未出现副作用。结论：冲击治疗法明显优于小剂量连续给药法。     

低剂量环磷酰胺减轻烧伤早期全身炎症介质综合征发生的实验研究

目的探讨低剂量环磷酰胺对烧伤大鼠全身炎症介质综合征 (SIRS)的控制作用。方法以大鼠为实验动物 ,分为空白组、对照组、实验组。对照组、实验组制作 5 0 %Ⅲ°烫伤模型 ,实验组于伤后 1小时腹腔内注射低剂量环磷酰胺 (2mg/kg) ,对照组腹腔内注射等量生理盐水。分别在伤后 2h、3h、6h测量 2组血液及肝脏组织中肿瘤坏死因子 (TNF -a)的含量。喂养至动物死亡观察两组动物的生存时间。结果实验组、对照组伤后 2小时血液及肝脏内TNF -a的含量明显高于未烧伤的空白组 (P <0 0 5 )。实验组伤后 2h、3h、6h血液及肝脏内TNF -a的含量明显低于对照组 (P <0 0 5 )。实验组动物的生存时间明显延长 (P <0 0 5 )。结论低剂量环磷酰胺能够减少烧伤后炎症介质的释放 ,能减轻烧伤后SIRS的发生。     

有机螯合锌对环磷酰胺模型小鼠免疫功能的影响

采用碳粒廓清法、二硝基氟苯诱导小鼠迟发型变态反应试验法及溶血素试验法 ,观察有机螯合锌对环磷酰胺所致免疫低下模型小鼠非特异性及特异性免疫功能的影响。结果表明 ,有机螯合锌能明显增加环磷酰胺所致免疫功能低下模型小鼠的脾脏指数和胸腺指数 ,增强单核巨噬细胞的吞噬功能、迟发型超敏反应强度 ,提高溶血素水平。提示有机螯合锌能增强免疫低下小鼠的非特异免疫功能和特异性细胞免疫及体液免疫功能。     

中剂量环磷酰胺或增大环磷酰胺剂量的常规化疗联合G-CSF动员恶性肿瘤患者外周血造血祖细胞

目的　多中心临床研究糖基化的G CSF联合中剂量环磷酰胺 (Cy)或增大针对性联合化疗中Cy剂量动员自体外周血造血祖细胞的效果。方法　北京地区 4所医院 30例患者纳入方案。其中非霍奇金淋巴瘤 (NHL) 2 1例 ,霍奇金病 (HD) 1例 ,乳腺癌 7例及卵巢癌 1例。采用中剂量Cy或以增大Cy剂量为基础的针对性化疗联合G CSF动员自体外周血造血祖细胞 (APBPC)。在化疗后白细胞计数达最低值时开始应用G CSF。当白细胞升至 5 .0× 10 9 L以上时 ,用血细胞分离机采集。结果　Cy平均实际使用剂量为 3.95g(2 .3g m2 ) ;G CSF的剂量分别为 2 5 0 μg d(2 9例 ) ,5 0 0 μg d(1例 ) ,实际剂量3 1～ 6 .4 μg·kg- 1 ·d- 1 。 30例患者平均采集 2 .7次 ,其中 13例采集 2次 ,14例采集 3次 ,3例采集 4次。达到目标采集量单个核细胞≥ 6× 10 8 kg为 2 1例 (70 .0 % ) ,CD34 + 细胞≥ 2× 10 6 kg为 30例 (10 0 % ) ,CFU GM≥ 2× 10 5 kg为 2 4例中 15例 (6 2 .5 % )。 1次采集后 2 7例 (90 .0 % )、2次采集后 2 9例 (96 .7% )患者达到了CD34+ 细胞数目标采集量。结论　G CSF 2 5 0 μg d联合中剂量Cy或以增大Cy剂量为基础的针对性化疗可采集到足够数量的APBPC。     

免疫净化联合小剂量环磷酰胺冲击治疗系统性红斑狼疮的临床对照研究

目的了解免疫净化联合小剂量环磷酰胺（CTX）冲击治疗系统性红斑狼疮（SLE）的疗效。方法回顾性分析北京大学人民医院SLE患者61例，其中28例给予免疫净化联合小剂量CTX冲击治疗，33例应用小剂量CTX冲击治疗，疗程1年。CTX每2周1次，每次400mg，连续3～6个月，之后每月1次，1次400mg；联合治疗组在给予CTX前均行免疫净化1～3次，2组患者均给予常规量糖皮质激素，疗程均为1年。监测患者症状，定期检测血常规、24h尿蛋白定量、血肌酐、白蛋白、免疫球蛋白、C3、C4、ANA、抗ENA抗体及抗dsDNA抗体水平。比较治疗前和治疗后1年不同组各项指标的变化。结果小剂量CTX冲击治疗1年后患者SLEDAI评分由治疗前平均13．73分降至平均5．44分；免疫净化联合小剂量CTX冲击治疗1年后患者SLEDAI评分由治疗前平均14．37分降至平均5．17分，2组统计学差异均有显著性。另外，治疗1年后小剂量CTX组和免疫净化联合小剂量CTX冲击治疗组抗ENA抗体分别转阴18．2％和42．9％，抗dsDNA抗体分别转阴39．4％和85．7％，2组统计学差异均有显著性。结论免疫净化联合小剂量CTX冲击治疗SLE的疗效优于小剂量CTX冲击治疗，且起效快，复发率低。     

BK virus-associated viruria and viremia in a patient with lymphangioleiomyomatosis after lung re-transplantation: A case report and review of the literature on BK virus infection post-lung transplantation

The BK virus (BKV) is a member of the polyomaviridae family of DNA viruses. BKV reactivates under a highly immunosuppressed state and causes renal dysfunction. In renal transplant patients, BKV infection leads to tubular impairment and loss of transplanted kidney grafts. However, few studies have reported on the relationship between BKV and lung transplantation. Adjustment of the dosage of immunosuppressants is needed in some cases, but the treatment method has not been established.Here, we report a case of BKV-associated viruria and viremia in a patient with lymphangioleiomyomatosis (LAM) after lung re-transplantation. A 44-year-old female refractory LAM patient who had undergone lung re-transplantation 3 months earlier was diagnosed with BKV-associated viruria and viremia. Urine cytology indicated decoy cells and the urine and serum polymerase chain reaction test was positive for BKV. As scheduled after re-transplantation surgery, immunosuppressive drugs were progressively reduced. This patient was considered to have experienced spontaneous BKV-associated viremia and viruria. Review of the literature suggested that 17%–42% of BKV-associated viruria cases have been reported after lung transplantation, but cases of BKV-associated nephropathy are rarely reported. Based on the present case, doctors involved in lung transplantation should monitor patients for BKV infection. Decoy cell monitoring by urine cytology is a useful screening method in the follow-up observation after lung transplantation. Early-stage interventions may prevent BKV-associated nephropathy even in patients who have developed BKV viremia, and sirolimus can be administered to patients with histories of BKV infection if they are carefully monitored.