γTNFβ体外杀伤肿瘤细胞的研究

用ＭＰＧ吸附层析法所制备的ＨｕＩＦＮ－γ／ＨｕＴＮＦβ重组双功能杂交蛋白（简称γＴＮＦβ）［１］去处理人宫颈癌细胞株ＭＥ１８０、胃癌细胞株７９０１和肺癌细胞株Ｇ６，结果表明此杂交蛋白对这三个细胞株都有明显的杀伤作用，其杀伤率显著高于同剂量的ＩＦＮ－γ或ＴＮＦ－β；用３Ｈ－ＴｄＲ掺入法观察γＴＮＦβ在不同时间、不同剂量条件下对Ｇ６的增殖抑制，可得到同样的结论。用γＴＮＦβ与丝裂霉素Ｃ（Ｍｉｔｏ－Ｃ）一起处理胃癌７９０１细胞，结果表明在Ｍｉｔｏ－Ｃ１．０μｇ／ｍＬ浓度以下、γＴＮＦβ５０ｕ／ｍＬ浓度以下，两者具有良好的抑病协同效应。用γＴＮＦβ处理胃癌、肺癌细胞以及ｙγＴＮＦβ与化学细胞毒性药物协同抑癌尚未见有报道。本文的结果为深入研究γＴＮＦβ可能具有更有效的抗癌效应提供了实验依据。     

Retroviruses released from a human tumor xenograft in nude mice induce colony-stimulating factor (CSF) activity in human fibroblastic cells

Summary A human colony-stimulating factor (CSF)-producing tumor transplanted into athymic nude mice released retroviruses in vitro. The viruses induced CSF activity in human fibroblastic cell lines.     

桑黄菌质多糖体外抑瘤及抗环磷酰胺致突变的作用

采用MTT法研究桑黄固态发酵菌质多糖（PISPS）对肝癌细胞（HepG-2）、乳腺癌细胞（MCF-7）生长的抑制作用，测定出多糖对细胞生长的最高抑制率为59．18％、55．39%，半数抑制浓度为196.9、162．5μg／mL，且随药物浓度的增加抑制率有增大的趋势，与正常组比较作用较为显著（P〈0．05）；选用小鼠骨髓嗜多染红细胞微核试验和小鼠精子畸形试验，对多糖的抗环磷酰胺（CP）致突变作用进行评价，结果表明桑黄菌质多糖使环磷酰胺诱发的细胞微核率和精子畸形率明显降低（P〈0．01）．     

钙阻断剂与肿瘤治疗

抗药性是肿瘤化疗的最大障碍之一,具抗药性的肿瘤细胞药物外排功能很强,而钙阻断剂能抑制抗癌药物从抗药性肿癌细胞排出,导致细胞抗药性减弱,可用于肿囊化疗,有潜在的临床应用价值,但有副作用。故应寻求毒副作用小类似钙阻断剂的其他修饰物以促进肿癌化疗。     

A pyruvate kinase variant in different mouse transplanted tumors

Summary Mouse transplanted tumors, in contrast to normal tissues, contain a pyruvate kinase (PK) variant sensitive to the inhibitory action of L-cysteine and less sensitive to saturated fatty acids than the normal enzyme. In selected normal and tumor materials two fractions of PK were separated. Fraction A (20–30% (NH₄)₂SO₄ saturation) dominated in normal liver, and fraction B (50–60% (NH₄)₂SO₄ saturation) in skeletal muscles and Ehrlich ascites tumor. Only this fraction B from tumor material was sensitive to L-cysteine, and seems to contain a tumor-specific PK variant which might be considered as a marker of neoplastic transformation in a broad spectrum of mouse experimental tumors.     

蛋白酶抑制剂在肿瘤治疗中的作用研究

蛋白酶及其抑制剂是非常重要的信号分子,涉及多个关键的人体生理代谢途径,在体内受到严格的调控.蛋白酶抑制剂活性的紊乱可导致多种疾病,诸如心血管和炎症疾病、癌症和神经系统障碍等.已知蛋白酶在肿瘤细胞侵袭和转移过程中扮演着重要的角色.细胞外基质和基底膜重塑是癌细胞侵袭转移过程中的关键环节,这个过程需多个蛋白水解酶的表达和激活.蛋白酶抑制剂的应用在一定程度上可减少由蛋白酶水解引起的肿瘤细胞的侵袭和转移,且它的抑制作用具有不同程度的特异性,可以减缓肿瘤恶性发展的进程.文章对蛋白酶及其抑制剂的靶向治疗药物及临床应用研究进展进行了综述.     

Dialdehyde starch nanoparticles as antitumor drug delivery system: An in vitro, in vivo, and immunohistological evaluation

Sustaining the release of therapeutic nanoparticles in a cell-, tissue-, or disease-specific manner is a potentially powerful technology. A new drug carrier-dialdehyde starch nanoparticle (DASNP) that can sustain the loading and release of 5-fluorouracil (5-Fu) antitumor drug is reported in this study. IR spectrophotometer and 1H NMR confirmed the formation of aldehyde groups, and scan electron microscope determinations showed that the dialdehyde starch nanoparticles obtained had an average diameter of 90 nm. 5-Fu, the model drug, was conjugated into nanoparticles by aldehyde groups. These 5-Fu-binding nanoparticles significantly enhanced breast cancer cell (MCF-7) inhibition in vitro compared with free 5-Fu. After subcutaneous 0 injection in the breast tumor-loaded rats, 5-Fu-DASNP exhibited remarkable tumor-inhibitory efficacy determined by measuring tumor weight in vivo. The tumor inhibition of 5-Fu-DASNP was 61%±6%, whereas that of free 5-Fu was only 42%±4%. Bcl-2/Bax immunohistochem-istry studies indicated that 5-Fu-DASNP remarkably induced tumor tissue necrosis. These results demonstrated that the DASNP prepared in this work is a potentially effective drug carrier.     

Leptomeningeal metastasis from central nervous system tumors: A study of classification and stage in the spinal canal of 58 patients

Leptomeningeal metastasis (LM) is caused by the spread of malignant tumor cells into the subarachnoid space.However,classification and staging of LM in the spinal canal is rare in the literature.The authors reviewed the records of 58 Chinese patients with LM for clinical features,neuroimaging,and treatments.Gadolinium-enhanced magnetic resonance imaging (MRI) of brain and spinal cord were performed in all patients.Removal of intracranial tumors was performed in all patients and diagnoses were confirmed by histology.The study group consisted of 58 patients,with 29 cases presenting with intraspinal symptoms.Of the 58,8 patients underwent intraspinal tumor removal,8 received radiotherapy alone,9 received chemotherapy alone,and 34 patients received combined radiochemotherapy.We classified LM into 3 types:type L or leptomeninges LM,is subdivided into 2 subtypes (subtype LI and LII (a,b)),type N or nerve root LM is subdivided into 2 subtypes (subtype NI and NII (a,b)),and type M or mixed-type LM.We also divided LM into stages of I-IV according to the symptoms and the volume of the tumor based on spinal axial MRI.Type LI LM often occurs in patients with intracranial and intraspinal tumors found simultaneously.Patients who receive surgery for intracranial tumors may present with type N LM.Surgery is suitable for patients with NI LM and LIIb LM in stages III-IV,presenting with severe spinal symptoms.The prognosis is better for type N LM than type L LM.     

基于级联可分离空洞残差U-Net的肝脏肿瘤分割

计算机辅助肝脏肿瘤分割可减少医生工作量,提高手术成功率,因而具有重要的临床诊疗价值。为获得精确的肝脏肿瘤自动分割结果,该文结合医学影像分割领域近年新兴的U-Net模块提出了基于级联可分离空洞残差U-Net（cascaded separable and dilated residualU-Net,CSDResU-Net）的肝脏肿瘤分割方法。CSDResU-Net采用了级联操作,解决了因肿瘤在整幅图像中占比小而造成的肿瘤分割数据不平衡问题;通过在分割网络中整合残差单元、深度可分离卷积和空洞卷积,能够增加卷积核感受野并快速提取更具判别性的肝脏肿瘤图像特征,从而提高肝脏肿瘤分割精度。在国际医学图像计算和计算机辅助干预协会肝脏肿瘤分割数据库上的实验结果表明,CSDResU-Net比基线方法的Dice系数指标提升了1.3%,同时发现空洞率对分割网络的性能表现影响较大。     

陡脉冲不可逆性电击穿恶性肿瘤细胞的机理

电场的基本特性是对处于场中的物质有力的作用.在陡脉冲电场作用下,细胞膜内外表面有很强的电场分布,同时由于细胞膜的介电常数与细胞外液、细胞质的不同,从电磁场理论出发,必然有作用于细胞膜表面的电场应力.仿真计算结果表明,外加电场的作用使得细胞膜受到来自细胞外液与细胞质两个方向的压力,作用在恶性肿瘤细胞膜上的电场应力的数量级比正常细胞大1个数量级.因此,在陡脉冲电场的作用下,恶性肿瘤细胞比正常细胞具有更大的敏感性,这种电场应力的作用势必对恶性肿瘤细胞膜造成巨大的损伤,使得细胞的生存环境和遗传物质受到严重破坏,并导致细胞发生不可逆性电击穿而死亡.