Do bisphosphonates reduce early micromotion and Periprosthetic bone loss in total knee arthroplasty? A review of the evidence

Early micromotion of implant components and periprosthetic bone loss in patients undergoing total knee arthroplasty are thought to contribute to late aseptic loosening. In the pursuit of longer implant survival, the administration of bisphosphonates may be advocated as a means to buffer implants against microinstability and periprosthetic bone loss. A bibliographic search identified one metaanalysis and two randomised controlled trials dealing with this topic. Current evidence supports the hypothesis that the inhibiting effects of bisphosphonates on bone resorption reduce implant micromotion and periprosthetic bone loss at the one-year follow-up. Tested bisphosphonates include clodronate, pamidronate and alendronate. However, a decline in periprosthetic BMD is observed at the three-year follow-up following a sixmonth course of bisphosphonate administration. Length of follow-up in available studies is currently too short to determine whether bisphosphonates increase the longevity of implants. Furthermore, the optimal dose, modality and length of bisphosphonate administration have yet to be determined.     

大黄素和小剂量雌激素合用对去卵巢大鼠骨质疏松的预防作用

目的观察大黄素和小剂量雌激素联合应用对去卵巢大鼠骨质疏松的预防作用.方法3月龄大鼠双侧卵巢去除术后预防用药90 d.用骨组织形态计量学方法,测定大鼠胫骨近端松质骨静态参数和动态参数,观察骨物理生长指标、血清生化指标和器官指数.结果大黄素90 mg·kg-1·d-1和己烯雌酚5 μg·kg-1·d-1联合应用可抑制去卵巢大鼠的破骨细胞活性,完全对抗其骨转化率增高和骨量丢失的骨质疏松症状,与己烯雌酚30 μg·kg-1·d-1的作用相当,且降低己烯雌酚对子宫和肝脏的刺激作用.结论大黄素和小剂量己烯雌酚联合应用可预防去卵巢大鼠骨质疏松.     

移植人羊膜细胞对大鼠创伤性脑损伤的实验研究

目的 探究大鼠TBI后脑内移植人羊膜细胞（HACs）对大鼠运动功能的影响。方法 HACs经分离、Hoechst33342标记后重悬调整细胞浓度为10^5/μl；采用改进的Feeney自由落体法打击大鼠脑皮层后肢运动区域，损伤后24h经微量注射器和立体定向仪将Hoechst33342标记的HACs 10μl分别移植于挫伤灶中心和挫伤灶边缘；在TBI后的28d内采用钉板平衡木行走测试大鼠运动功能变化，运动功能检测结束后取出脑组织行组织学检测。结果 治疗组滑落脚步数明显少于对照组（P〈0．05）；移植的HACs呈蓝色荧光；部分移植HACs可见MAP-2阳性表达。结论 移植HACs使大鼠TBI后运动功能明显改善。     

Particulate endocytosis mediates biological responses of human mesenchymal stem cells to titanium wear debris.

Continual loading and articulation cycles undergone by metallic (e.g., titanium) alloy arthroplasty prostheses lead to liberation of a large number of metallic debris particulates, which have long been implicated as a primary cause of periprosthetic osteolysis and postarthroplasty aseptic implant loosening. Long-term stability of total joint replacement prostheses relies on proper integration between implant biomaterial and osseous tissue, and factors that interfere with this integration are likely to cause osteolysis. Because multipotent mesenchymal stem cells (MSCs) located adjacent to the implant have an osteoprogenitor function and are critical contributors to osseous tissue integrity, when their functions or activities are compromised, osteolysis will most likely occur. To date, it is not certain or sufficiently confirmed whether MSCs endocytose titanium particles, and if so, whether particulate endocytosis has any effect on cellular responses to wear debris. This study seeks to clarify the phenomenon of titanium endocytosis by human MSCs (hMSCs), and investigates the influence of endocytosis on their activities. hMSCs incubated with commercially pure titanium particles exhibited internalized particles, as observed by scanning electron microscopy and confocal laser scanning microscopy, with time-dependent reduction in the number of extracellular particles. Particulate endocytosis was associated with reduced rates of cellular proliferation and cell-substrate adhesion, suppressed osteogenic differentiation, and increased rate of apoptosis. These cellular effects of exposure to titanium particles were reduced when endocytosis was inhibited by treatment with cytochalasin D, and no significant effect was seen when hMSCs were treated only with conditioned medium obtained from particulate-treated cells. These findings strongly suggest that the biological responses of hMSCs to wear debris are triggered primarily by the direct endocytosis of titanium particulates, and not mediated by secreted soluble factors. In this manner, therapeutical approaches that suppress particle endocytosis could reduce the bioreactivity of hMSCs to particulates, and enhance long-term orthopedic implant prognosis by minimizing wear-debris periprosthethic osteolysis.     

直肠癌切除前后腹腔冲洗液脱落细胞学对比研究

目的研究直肠癌术中腹腔多次冲洗，对于降低患者腹腔内脱落癌细胞阳性率的临床意义。方法对63例直肠癌患者术中腹腔冲洗分6次进行，肿瘤切除前3次，切除后3次；将6次腹腔冲洗液行常规病理学涂片细胞学检查结果进行对比。结果肿瘤切除前，全组患者腹腔冲洗液脱落癌细胞均呈阳性表达。肿瘤切除后第1次腹腔冲洗液脱落癌细胞阳性40例，第2次阳性33例，第3次阳性13例。肿瘤切除后第1次冲洗液的脱落癌细胞阳性结果与切除后第2次冲洗液阳性结果比较，P〉0.05，差异无统计学意义；但第3次冲洗液的脱落癌细胞阳性结果与第2次比较，P〈0.01，差异有统计学意义。结论对直肠癌患者进行术中多次腹腔冲洗可降低腹腔内脱落癌细胞的阳性率。     

Bone and joint alterations in acromegaly

Growth hormone (GH) is fundamental for the maintenance of bone mass and metabolism both during childhood and in adulthood. This effect is due to a complex interaction between circulating GH and IGF-I produced peripherally. In vitro data and experimental animal models have clarified many of the regulatory mechanisms underlying the characteristic skeletal changes occurring in acromegaly. This review focuses on the effects of GH excess on bone metabolism and mass in acromegalic patients and, in particular, on the influence of factors such as hypogonadism, gender, age and therapy on bone metabolism and arthropathy.     

手术治疗胸腰椎结核合并后凸畸形

目的:探讨单切口双入路椎弓根系统内固定、后外侧植骨同期病灶清除、椎间植骨治疗胸腰椎结核合并后凸畸形的疗效。方法:对78例胸腰椎结核合并后凸畸形患者采用单切口双入路行后外侧植骨椎弓根系统内固定,同期病灶清除、椎间植骨治疗,观察患者症状及截瘫改善情况,后凸畸形矫正情况及植骨融合情况。结果:所有患者症状均明显改善,48例合并截瘫的患者中,25例完全恢复正常,7例ASIA分级改善1￣3级;植骨均在术后6个月￣1年融合,治愈率52.08%,好转率14.58%。后凸Cobb角平均矫正28.7°,随访1.4￣6.5年,平均2.6年,后凸角平均丢失2.9°。结论:单切口双入路后外侧椎弓根系统内固定同期病灶清除、椎间植骨可恢复脊柱的即刻稳定性,有利于植骨融合,后凸畸形矫正满意。     

Gastrointestinal stromal tumours: a regular origin in the muscularis propria, but an extremely diverse gross presentation

Background Gastrointestinal stromal tumours (GISTs) are thought to arise from the interstitial cells of Cajal (ICCs). ICCs form a network surrounding the myenteric plexus and between-muscle fibres of the muscularis propria of the tubular GI tract. The cell of origin of so-called extra-gastrointestinal stromal tumours (EGISTs) is not known.Aim and methods To study the diversity of gross presentation of GISTs and to critically assess the incidence of EGISTs and their relationship to mural GISTs, a total of 200 neoplasms with typical morphologic and immunohistochemical features of GISTs were reviewed, looking for any degree of association with the muscularis propria of the gut wall.Results There were 130 gastric (65%), 9 duodenal (4.5%), 48 small intestinal (24%), 9 colorectal (4.5%), 1 appendiceal (0.5%) and 3 unclassifiable GISTs (1.5%). Fourteen cases (7%) were initially submitted as EGISTs (four mesenteric, four omental, one pararectal/prostatic, one pelvic/Douglas, one perivesical, one located between root of mesentery and tail of pancreas, one involving the mesentery, omentum and abdominal wall extensively and one located between liver and stomach). After critical re-evaluation of surgical reports and remote clinical history and a careful search for residual muscular tissue from the gut wall in the tumour pseudocapsule (in some cases supported by desmin immunoreactivity), it was possible to reclassify most of these cases (11/14) as either GISTs with extensive extramural growth resulting in loss of contact to the external muscle coat of the gut (8/14) or as metastases from an inoperable GIST (2/14) or from a previously resected deceptively benign tumour (1/14).Conclusion EGISTs are probably rarer than previously reported (1.5% or less in this study). We concluded that most so-called EGISTs represent apparent EGISTs that should have arisen from the outermost muscle coat, but have lost their contact to the point of origin due to extensive extramural growth pattern. From a surgical point of view, it is crucial to document and mark any focal attachment or adhesions to the gut wall noticed during surgery for an apparent EGIST. In contrast to most other neoplasms, GISTs should be defined by virtue of any degree of association with the muscularis propria (no matter how minimal), but not by localisation of the bulk of the tumour.     

MBP对PBMC产生IFN-γ和NO的影响

目的探讨T细胞非特异性活化在CNS脱髓鞘性疾病中的作用。方法分离实验性自身免疫性脑脊髓炎(EAE)易感性BALB/c小鼠外周血单个核细胞(PBMC),采用体外细胞培养方法在体外与碱性髓鞘蛋白(MBP)共培养,测定培养上清液中IFN-γ、NO水平。结果经MBP刺激的PBMC产生IFN-γ[(43.83±6.06)pg/mL]和NO[(180.76±20.75)μmol/L]明显增加,与对照组产生的IFN-γ[(28.52±2.18)pg/mL]和NO[(95.61±13.09)μmol/L]相比差异有统计学意义(P<0.01)。结论在CNS脱髓鞘性疾病发病过程中,活化的T细胞、单核细胞等分泌致炎细胞因子和其他有害物质增多。