骨细胞的功能：生物学研究和机理探讨

骨细胞（osteocyte）是在矿化骨基质内名副其实的骨的细胞（bonecell）。通过细胞突触，骨细胞彼此相连，很可能也与骨髓中某些细胞相接，从而形成三维细胞网络。从骨的超微结构看，骨细胞处于很理想的位置，可以担当骨生理的重要调节因子。然而，由于骨细胞处于矿化骨基质深层，对其功能了解甚少。但随着新技术方法的应用，就有可能对这种成骨细胞系中的终末分化细胞进行深入研究，人们也由此对骨细胞的兴趣大增。骨细胞被认为是骨的机械应力感受器，它有可能参与骨重建。骨细胞能分泌具有调节成骨细胞功能的硬骨素（sclerostin）。一种能降低肾脏磷回吸收的激素——调磷因子FGF23也主要源白骨细胞。随着我们对骨细胞了解的深入，清楚显示，骨细胞不仅能影响局部骨转换活性，而且对全身矿物质的体内平衡也有多种功能。因此，对骨细胞的研究，可以为代谢性骨病的治疗探索新的途径。     

微创锁定加压接骨板内固定治疗胫骨骨折

臀肌挛缩症的手术治疗方法较多,我们采用大转子后上方双侧小“S”微创切口,每侧切口长约2~3 cm,对挛缩组织进行切断,广泛松解,重症患者行臀中小肌“Z”形延长,松解髋关节囊,并行屈膝屈髋、交叉架腿、划圈征等各项指标评价,配合术后早期功能锻炼治疗,效果满意,1997-2005年8月,共收治2 518例患者,重点研究讨论其病因、分类及治疗。1临床资料1·1诊断臀肌挛缩症的诊断包括病史,特别是婴儿期臀部反复肌肉注射史,特有的外“八”字步态,并膝下蹲困难,站立时的尖臀征,快步行走或跑步时呈跳步征。臀部触诊时可触及索带硬块,划圈征、二郎腿试验及平…     

Coagulation screening before epidural analgesia in pre-eclampsia

A questionnaire survey of current practice at a small cross-section of obstetric units, covering 22% of all United Kingdom deliveries, revealed a marked lack of standard practice regarding requests for coagulation screens on pre-eclamptic patients who require epidural procedures. A retrospective audit was therefore carried out on 434 coagulation screens requested for pre-eclamptic patients in whom epidural analgesia might have been considered. Borderline abnormalities of coagulation were found in only 10 patients (2%). Platelet counts of less than 150 x 10(9)/litre were present in 28% of cases. 'Significant' thrombocytopenia (less than 100 x 10(9)/litre) and all coagulation abnormalities were only encountered in severe pre-eclampsia (diastolic blood pressure of greater than 110 mmHg and proteinuria of + + or greater). Furthermore, coagulation abnormality was always associated with a reduced platelet count (mean, 97 x 10(9)/litre). This study would therefore support anaesthetic practice which restricted any requests for coagulation testing to severe pre-eclamptic patients only. For these patients first line testing could be limited to a platelet count.     

平阳霉素对HeLa细胞的大分子生物合成及超微结构的影响

作者用同位数前体参入法及透射与扫描电镜研究了平阳霉素(博莱霉素A_5)对HeLa细胞大分子生物合成及超微结构的影响。结果显示:平阳霉素能抑制HeLa细胞DNA,RNA和蛋白质的生物合成,对DNA的抑制作用强,ID_(50DNA)为42.77μg/ml。表现为:染色质减少,核内电子密度低,核仁分离及“核仁帽”形成,细胞表面微绒毛消失或变形,最终导致质膜破裂等。作者认为,细胞膜是否为此类药物作用的靶位值得进一步研究。     

转TrkC基因神经干细胞移植对脊髓损伤的治疗作用

目的 研究转酪氨酸激酶C（tyrosine kinase C，TrkC）基因神经干细胞（neural stem cells，NSCs）移植治疗脊髓损伤的作用。方法 60只SD大鼠随机分成正常对照组（A组）、脊髓半切组（B组）、NSCs移植组（C组）、NSCs移植＋神经营养素（NT）-3局部使用（D）组、转TrkC基WNSCs移植组（E组）和转TrkC基因NSCs移植＋NT-3局部使用组（F组），每组10只。脊髓损伤后第9天进行细胞移植。各组大鼠在细胞移植后2个月，行体感诱发电位（SEP）和运动诱发电位（MEP）检查以及脊髓运动功能（BBB）评分。结果 细胞移植后2个月SEP和MEP发生潜伏期和峰峰波幅以及右后肢BBB评分的恢复均以下组最佳，与其他各组比较，差异有统计学意义（P＜ 0．05，0．01）。结论在局部给予的NT-3作用下，转TrkC基因NSCs能较好地促进损伤脊髓功能的恢复。     

不同组织来源临床肿瘤主要细胞周期素表达类型的研究

目的观察人类主要细胞周期素（Cyclin D1、E、A、B1）在临床肿瘤细胞中表达特征并进行分类，探讨其对临床肿瘤分类的可行性及潜在意义。方法用流式细胞术（FCM）双参数法半定量检测161例恶性肿瘤手术切除标本细胞中Cyclin D1、E、A、B1表达，根据不同Cyclin在细胞周期中的作用及其异常表达特征，将肿瘤细胞主要Cyclin表达分为不同类型。结果细胞周期外Cyclin（D1）及周期内Cyclins（E、A、B1）在临床肿瘤细胞中表达无组织差异性（P〉0．05）。其异常表达大致可归为5种类型：Ⅰ型Cyclin（D1、E、A、B1）均高表达；Ⅱ型Cyclin D1低表达，Cyclin（E、A、B1）不同形式高表达；Ⅲ型Cyclin D1不表达，Cyclin（E、A、B1）不同形式高表达；Ⅳ型Cyclin D1不表达，Cyclin（E、A、B1）不同形式低表达；V型Cyclin（D1、E、A、B1）均不表达；再根据各型中不同周期内Cyclin的优势表达分为相应不同的亚型。a亚型：Cyclin（E、B1）表达为主；b亚型：CyclinE表达为主；c亚型：Cyclin B1表达为主；d亚型：Cyclin（E、A、B1）表达为主。肿瘤细胞主要Cyclin表达类型及相应亚型分布无组织来源的差异性（P〉0．05）。结论主要Cyclins表达类型可以作为不同组织来源肿瘤分类的依据，可能是体现不同肿瘤细胞周期破坏共同特征较为客观分类方法。     

Lower limb blocks for children

Femoral and lateral cutaneous nerve of the thigh blocks have been performed in a group of 50 children; the method has not previously been described in paediatric practice. The technique was judged to have been successful in 48 (96%) of the children. There were no early or late complications. It is concluded that these blocks are easy to perform, even in small children and infants, and that they can produce reliable postoperative analgesia for a variety of orthopaedic and plastic procedures.     

Induction of apoptosis in human hepatocarcinoma SMMC-7721 cells in vitro by flavonoids from Astragalus complanatus

Aim of the study

Flavonoids extracted from the seeds of Astragalus complanatus R.Br. reduce the proliferation of many cancer cells. The present study was carried out to evaluate the effects of these flavonoids from Astragalus complanatus (FAC) on human hepatocarcinoma cell viability and apoptosis and to investigate its mechanisms of action in SMMC-7721 cells.

Materials and methods

Cell viability was measured using the MTT assay. To detect apoptotic cells, SMMC-7721 cells treated with FAC were stained with Hoechst 33258 and subjected to agarose gel electrophoresis. Quantitative detection of apoptotic cells was performed by flow cytometry. The effects of FAC on apoptosis and cell cycle regulatory genes and proteins in SMMC-7721 cells were examined using an S series apoptosis and cell cycle gene array and Western blot analysis.

Results

The growth of SMMC-7721 and HepG2 cells was inhibited by treatment with FAC. Cell death induced by FAC was characterized by nuclear condensation and DNA fragmentation. Moreover, the cell cycle was arrested in the G0/G1 and S phases in FAC-treated SMMC-7721 cells. A sub-G1 peak with reduced DNA content was also formed. The activity of caspase-3 was significantly increased following FAC treatment. Microarray data indicated that the expression levels of 76 genes were changed in SMMC-7721 cells treated with FAC: 35 genes were up-regulated and 41 were down-regulated. Western blot analysis showed that caspase-3, caspase-8, Bax, P21, and P27 protein levels in SMMC-7721 cells were increased after 48 h of FAC treatment, while cyclinB1, cyclinD1, CDK1, and CDK4 protein levels were decreased.

Conclusions

These results suggest that FAC may play an important role in tumor growth suppression by inducing apoptosis in human hepatocarcinoma cells via mitochondria-dependent and death receptor-dependent apoptotic pathways.