Transformation of immortal, non-tumorigenic osteoblast-like human osteosarcoma cells to the tumorigenic phenotype by nickel sulfate

Epidemiological studies have indirectly linked compounds ofchromium, nickel and arsenic to human carcinogenesis. However,there is no evidence that metal compounds can transform humancells to the tumorigenic phenotype in culture. We show herethat exposure to 36 µM NiS0₄ for 48–96 h resultsin transformation of an immortal, non-tumorigenic, osteoblast-likecell line, HOS TE85, to the tumorigenic phenotype. Continuouspassaging following treatment leads to the formation of a fewdense foci. The cells isolated and expanded from the foci aremorphologically transformed, and form anchorage-independentcolonies of the size and abundance comparable to that formedby Kirsten murine sarcoma virus transformed HOS TE85 cells.The transformed cells from tumors in nude mice, have enhancedlevels of plasminogen activators and have lost the ability toform model bone matrix on extended culture in the presence ofascorbic acid and ß-glycerophosphate. A number ofcell lines have been established from nude mouse tumors. Cytogeneticanalysis reveals 16 marker chromosomes and an aberrant chromosome16. This is the first report of the transformation of a humancell line to tumorigenic phenotype by a metal carcinogen.     

人发角蛋白对脊髓损伤大鼠少突胶质细胞增殖分化效应的影响

目的探讨体内可降解生物材料人发角蛋白(HHK)植入急性冲击性损伤脊髓后,对神经再生过程中少突胶质细胞增殖分化效应的影响。方法采用改制Ⅱ型NYU装置,在建立大鼠急性冲击性脊髓损伤模型基础上,将经过特殊处理后能在体内降解的HHK植入大鼠脊髓损伤部位,对植入后1、4、12、26周损伤脊髓组织进行光学和电镜结构观察。结果第1周时,损伤部位可见少突胶质细胞散在分布于大量浸润的炎症细胞中;第4周时,通过Mallory's磷乌酸苏木素染色,显示HHK周边呈层包绕的增生少突胶质细胞;第12和26周主要为神经再生和髓鞘重建过程,重建中的少突胶质细胞髓鞘内出现较大的空腔,髓鞘层状分离,并形成大小不一的髓鞘小体,重建髓鞘周边可见新生的少突胶质细胞。结论在急性冲击性脊髓损伤后神经再生过程中,HHK对少突胶质细胞的增殖分化及髓鞘再生修复有积极作用,为进一步综合研究HHK对脊髓损伤修复的作用提供了实验依据。     

胸腰椎骨折椎弓根内固定治疗的疗效评定

目的 探讨轴形内固定(AF)椎弓根系统治疗胸腰椎骨折的疗效。方法 对1996～2000年采用AF系统治疗的60例胸腰椎骨折病例进行回顾总结。随访3～6年，平均4年。结果 神经功能恢复按ASIA分为A、B、C、D、E5级，其中恢复两个级差的27例，恢复一个级差的33例；与正常相比伤椎高度平均矫正95．1％，远期矫正丢失率为19．7％，伤椎固定节段上下椎间隙部分变窄，上间隙较重。结论 后路AF系统治疗胸腰椎骨折对于神经功能、伤椎高度的恢复疗效肯定，但存在内固定断裂，矫形丢失等问题，未充分植骨及内固定未及时取出是主要原因。     

螺簧多用弓装置矫治安氏Ⅱ2错(牙合)

目的:探讨采用一种新式矫治装置矫治安氏Ⅱ2错(牙合)的临床效果.方法:选自第四军医大学口腔医院正畸科门诊安氏Ⅱ2病例20例(其中男9例,女11例),平均年龄12.6岁(10～～15.8岁).矫治装置使用多用弓 唇弓,在其上套入Ni-Ti推簧,并焊上拉钩,借助Ⅱ类牵引的力值(150g～200g),推上颌磨牙向远中移动,并适当牵引下颌后牙向近中移动,最终调整磨牙关系由Ⅱ类成为Ⅰ类.术前术后摄头颅侧位x线片,测量上下磨牙的远中、近中位移.结果:经过平均4.5个月的治疗(3.4～5.8个月),上颌磨牙平均远移2.16±1.3 mm,而下颌磨牙平均向近中移动1.38±0.64 mm.最终磨牙的Ⅱ类咬合关系得到纠正.结论:NiTi螺旋弹簧多用弓装置是一种有效的改正Ⅱ类磨牙关系的治疗方法,其矫治机制是在上颌磨牙远移的基础上,下颌磨牙适当近移共同作用的结果.     

内镜下套扎与硬化夹心联合法治疗食管静脉曲张出血的研究

目的　了解套扎与硬化夹心联合法 (套扎 硬化 套扎 )能否获得优于单纯内镜下食管静脉曲张结扎 (EVL)的疗效。方法　对 98例肝硬化食管静脉曲张伴活动性出血或近期出血的患者随机采用单纯EVL或夹心法治疗 (EVL组 5 0例 ,夹心法组 4 8例 )。EVL组每条曲张静脉结扎皮圈不超过 3个 ,夹心法组每条曲张静脉结扎 2个皮圈 ,并在两个结扎点之间的曲张静脉内注射 1～ 3ml硬化剂。夹心法组 7例在首次内镜治疗时接受食管静脉造影检查。 7～ 10d重复 1次内镜治疗 ,直至静脉曲张消除。结果　 7例行静脉造影检查 ,其中 6例硬化剂在曲张静脉内滞留时间超过 4 5min。两种方法控制活动性食管静脉曲张出血 (EVB)的止血成功率相同 (10 0 .0 % ) ;两组间静脉曲张消除率相似 (夹心法组 93.8% ,EVL组 90 .2 % ,P >0 .0 5 ) ,但夹心法组一次治疗后静脉曲张消除率明显高于EVL组 (6 6 .7%比10 .0 % ,P <0 .0 0 1) ,达到消除的平均治疗次数明显减少 (1.2± 0 .4比 3.8± 1.5 ,P <0 .0 1) ,所需时间显著缩短 [(13.1± 4 .3)d比 (42 .5± 16 .7)d ,P <0 .0 1];与EVL组相比 ,夹心法组再出血率较低 (8.3%比2 8.0 % ,P <0 .0 5 ) ,随访期内静脉曲张复发率明显下降 (8.3%比 4 4 .0 % ,P <0 .0 0 5 ) ;两组间并发症发生率相似 (夹心法组 1     

Problems in the design of anticancer agents

Theoretically, two predominant paths for obtaining more selective anticancer agents may be envisaged. These are: (a) to make compounds which distribute only or preferentially in cancer cells; (b) to make compounds that are able selectively to kill or to differentiate cancer cells. Although in the last two decades research into new anticancer drugs has not produced satisfactory results, there is solid ground on which novel strategies can be developed, mainly based on a much greater biological knowledge of human tumours. This article does not review all the possible approaches that may be followed, but simply discusses some ideas and problems mainly taken from the current research of our laboratory.     

创伤性休克后血浆黏附分子的变化及不同复苏液的影响

目的　探讨创伤性休克兔中性粒细胞黏附分子CD11b、血清可溶性细胞间黏附分子(sICAM ) 1的动态变化及不同复苏液的影响。方法　 72只创伤性休克模型兔分为 6组 ,林格氏液组按失血量 2倍输入乳酸林格氏液 ,其他各组按 6ml/kg分别输入右旋糖酐 40、70 6代血浆、7.5 %氯化钠和 2 0 %白蛋白。分别采用流式细胞仪、酶联免疫吸附法检测CD11b、sICAM 1表达值。结果　各实验组休克 1hCD11b及sICAM 1表达增高 ,与对照组比较差异有显著性 (P <0 .0 5 ) ,并于12h达最高值 (林格氏液组 85 .6± 12 .1,60 9.3± 10 1.3 ;高渗盐组 77.5± 10 .3 ,5 18.5± 87.2 ;白蛋白组 78.2± 10 .7,5 2 2 .4± 88.3 ;P <0 .0 1)。高渗盐和白蛋白组 2 4、48hCD11b和sICAM 1分别为5 9 .2± 6.9,5 4.6± 5 .9;3 60 .1± 68.4,2 74.4± 40 .1;5 8.9± 6.4,5 5 .0± 5 .8;3 5 2 .6± 65 .3 ,2 70 .2±3 8.2 ,较林格氏液组 (72 .3± 10 .1,65 .8± 8.3 ;5 0 2 .6± 84.5 ,3 42 .4± 63 .1)降低 (P <0 .0 5 ) ;高渗盐和白蛋白组 (8.3 % )复苏 48h动物死亡率较林格氏液组 (4 1.7% )低 (P <0 .0 5 )。结论　创伤性休克时PMNCD11b和sICAM 1表达增加 ;采用 7.5 %氯化钠或 2 0 %白蛋白复苏时表达值及死亡率较乳酸林格氏液低。     

Effect of a segregated-care system on patients' length of stay in intensive care

The Internal Medicine Residency Program of the Raritan Bay Medical Center's Perth Amboy Division was changed in July 1987 from a full continuity-of-care system to a unit-isolation one. The authors compared patients' data from the first two months of the academic years 1986-87 and 1987-88 and were unable to observe any impact of the change on length of stay in intensive care. However, informal interviews with the house staff members indicated that the change had a positive impact on their education, because of their closer observation of the pathophysiology of individual disease states and greater enjoyment of the time spent in critical care.     

Regulation of immunoglobulin heavy-chain gene rearrangements

Summary: Regulated assembly of antigen receptor gene segments to produce functional genes is a hallmark of B‐ and T‐lymphocyte development. The immunoglobulin heavy‐chain (IgH) and T‐cell receptor β‐chain genes rearrange first in B and T lineages, respectively. Both loci require two recombination events to assemble functional genes; D‐to‐J recombination occurs first followed by V‐to‐DJ recombination. Despite similarities in overall rearrangement patterns, each locus has unique regulatory features. Here, we review the characteristics of IgH gene rearrangements such as developmental timing, deletion versus inversion, D_H gene segment utilization, ordered recombination of V_H gene segments, and feedback inhibition of rearrangement in pre‐B cells. We summarize chromatin structural features of the locus before and during recombination and, wherever possible, incorporate these into working hypotheses for understanding regulation of IgH gene recombination. The picture emerges that the IgH locus is activated in discrete, independently regulated domains. A domain encompassing D_H and J_H gene segments is activated first, within which recombination is initiated. V_H genes are activated subsequently and, in part, by interleukin‐7. These observations lead to a model for feedback inhibition of IgH rearrangements.