Lymphoid Neogenesis in Murine Cardiac Allografts Undergoing Chronic Rejection

Lymphoid neogenesis is the process by which ectopic lymphoid accumulations that resemble lymph nodes arise in nonlymphoid tissues. Such lymphoid accumulations, known as tertiary lymphoid organs (TLO), are observed in chronic autoimmunity and they propagate immune pathology by setting up local antigen presenting sites. Whether lymphoid neogenesis occurs in transplanted organs and contributes to rejection is not well understood. To begin to address this question, we retrospectively analyzed 319 murine cardiac allografts for microscopic evidence of lymph-node-like structures. We found 78 allografts that had either classical TLO, characterized by discrete T- and B-cell zones and high endothelial venules (HEV) expressing peripheral node addressin (PNAd) (n = 34), or PNAd(+) HEV without organized lymphoid accumulations (n = 44). These changes were present in both short- and long-lived allografts and were invariably associated with rejection. Importantly, they occurred in 78% of allografts undergoing chronic rejection (n = 85) but in only 7% of allografts undergoing primarily acute rejection (n = 184). These findings indicate that, like autoimmunity, alloimmunity is associated with lymphoid neogenesis in the target organ and suggest a role for local T-cell activation in chronic allograft rejection.     

Allopeptide-Specific CD4+ T Cells Facilitate the Differentiation of Directly Alloreactive Graft-Infiltrating CD8+ T Cells

To investigate the mechanism of CD4(+) T-cell help during the activation and differentiation of directly alloreactive CD8(+) T cells, we examined the development of obliterative airways disease (OAD) following transplantation of airways into fully mismatched recipient mice deficient in CD4(+) T cells. BALB/c trachea allografts became fibrosed significantly less frequently in B6 CD4(-/-) recipients as compared to wildtype controls. Furthermore, class I-directed cytotoxicity failed to develop in the absence of CD4(+) T cells. The infiltration of graft tissue by primed L(d)-specific directly alloreactive 2C CD8(+) T cells was not found to depend on the presence of CD4(+) T cells. Nevertheless, graft-infiltrating 2C CD8(+) T cells failed to express CD69 and granzyme B when CD4(+) T-cell help was unavailable. Importantly, reconstitution of B6 CD4(-/-) recipient mice with graft peptide-specific TCR-Tg CD4(+) T cells (OT-II or TEa) capable of recognizing antigen only on recipient APC allowed for full expression of CD69 and granzyme B by the directly alloreactive CD8(+) T cells and restored the capacity of recipients to reject their allografts. These results demonstrate that indirectly alloreactive CD4(+) T cells ensure the optimal activation and differentiation of graft-infiltrating directly alloreactive CD8(+) T cells independent of donor APC recognition.     

胚胎颅骨骨膜移植修复髋关节软骨大面积缺损

１９９０年５月～１９９４年４月，对４２例（４７个髋）关节软骨全厚缺损患者采用冷冻保存胚胎颅骨骨膜移植进行修复，其中１４例股骨头骨质Ⅳ期坏死者，同时施行带旋髂深血管蒂髂骨植骨。对３４例（３８个髋）进行了２年～６年（平均４０个月）随访。结果表明，按照吴之康髋关节人工置换术后疗效评定标准，优良２５例，很好５例，好３例，尚可１例。认为，与自体移植物修复关节软骨大面积缺损相比，这种方法无附加损伤，具有移植材料、形态与股骨头相似等特点，是治疗髋关节软骨大面积缺损的一种有效方法。     

The Cellular Lesion of Humoral Rejection: Predominant Recruitment of Monocytes to Peritubular and Glomerular Capillaries

Accumulation of inflammatory cells within capillaries is a common morphologic feature of humoral renal allograft rejection and is most easily appreciated if it occurs in glomeruli. The aim of our study was to determine the amount and composition of immune cells within glomeruli and peritubular capillaries (PTC) in cellular and humoral allograft rejection. Immunofluorescent double-labeling for CD31 and CD3 or CD68 was used for phenotyping and enumerating immune cells within glomeruli and PTC. The major findings are: (1) accumulation of immune cells in PTC is far more common than it would be anticipated based on the assessment by conventional histology; (2) it is not the absolute number of immune cells accumulating within capillaries, but rather the composition of the intracapillary cell population that distinguishes humoral rejection from cellular rejection and (3) in C4d positive biopsies a predominantly monocytic cell population accumulates not only within glomeruli but also within PTC. The median value of monocyte/T-cell ratio within PTC was 2.3 in C4d positive biopsies but only 1 (p = 0.0008) in C4d negative biopsies. Given their prominent presence within capillaries and their extensive biological versatility monocytes might contribute to the capillary damage observed in acute and chronic allograft rejection.     

Anterior lumbar fusion using a hybrid interbody graft

Summary This is a radiographic report of 40 patients (20 men, 20 women) who underwent anterior lumbar interbody fusions (73 levels) utilizing a “hybrid” interbody graft composed of femoral cortical allograft (FCA) bone and iliac crest cancellous autograft bone. The average age at surgery was 38 years (range 17–64 years), and follow-up averaged 1.4 years (range 1.0–2.4 years). Nineteen of the patients had undergone previous lumbar surgery. Thirty-two patients (63 levels) underwent anterior fusion combined with some type of posterior fixation, and eight patients (10 levels) had no posterior fixation. Types of posterior fixation included: for 20 patients (36 levels) Steffee variable screw placement fixation, for 10 patients (23 levels) translaminar facet screws (TFS), for 1 patient (3 levels) Knodt rods and for 1 patient (1 level) facet screws. Based on the persistence of lucent lines at the graft-host interface, three patients (one level each) were felt to have non-unions at their latest follow-ups at 1.4, 1.5 and 2.0 years, respectively. Two of these patients had no posterior fixation, and the other had TFS fixation. The overall fusion rate was 96% (70 of 73 levels). The fusion rate for all levels treated with posterior fixation was 98% compared with 75% for those without fixation. Intervertebral disc heights (IVDH) were measured on all films and corrected for magnification with computer assistance. On average, the IVDH was increased postoperatively but returned to preoperative values at follow-up. IVDH loss was independent of the type of instrumentation used. No complications arose from the use of the hybrid graft. Incorporation of the allograft portion of the graft is slow and was felt to be complete in only 7 of the 73 levels at follow-up. We conclude that the hybrid interbody graft technique is a safe and reliable method for performing anterior lumbar interbody fusions and should be combined with some type of posterior fixation. Long-term follow-up will be required to assess the behaviour of the allograft until incorporation is complete.     

小型猪胰腺移植急性排斥反应模型的实验研究

目的　建立小型猪胰腺移植动物模型 ,探索早期诊断急性排斥反应的方法。方法　 4 0只猪随机配对行胰腺移植 2 0次 ,将供胰所带的血管与受体髂血管吻合 ,所带小段十二指肠与空肠吻合 ,术中监测平均动脉压、中心静脉压及血气。术后测定受体的血淀粉酶、血糖 ,监测外周血免疫指标 ,彩色多普勒检测供胰血流及超声引导下活检、组织病理检查。结果　移植手术成功率为 90 % ,受体平均动脉压在吻合血管开放后有明显下降 ,与血流开放前差异有显著性 (P <0 0 5 ) ,输血有助于手术成功 ,受体术后平均存活 (12 6± 2 3)d。外周血免疫学监测指标早于供胰的组织病理改变 ,两者的改变均早于急性排斥反应的临床表现。结论　小型猪适用于胰腺移植模型的建立 ,加强术中循环功能的管理、及时输血有利于受体成活 ;超声引导下穿刺活检供胰的组织病理学检查与监测外周血免疫指标均适于早期诊断急性排斥反应     

股骨远端复杂骨折的手术治疗

目的探讨股骨远端严重粉碎骨折有效治疗方法. 方法在动物实验基础上,我们于2001年3月～2002年8月,应用AO髁支持钢板及自行设计翼状解剖型钢板内固定与同种异体骨移植治疗股骨远端复杂骨折26例,均为AO/ASIF分类中33C3.3.采用AO技术,术中平均植骨46 g. 结果术后24例伤口Ⅰ期愈合,2例伤口感染经换药愈合.24例4～11个月达到骨性愈合,2例过早负重致固定失败而再次手术.随访7～25个月,平均14个月,根据Shelbourne and Brueckmann膝关节功能评定标准,优5例,良18例,可1例,差2例,优良率为88.5%. 结论翼状解剖型钢板远端螺钉孔为长椭圆形且有连续钉孔,适合于严重粉碎骨折;翼状解剖型钢板及髁支持钢板内固定与充分植骨是治疗股骨远端复杂骨折较理想的方法,同种异体骨可以取代自体髂骨植骨.     

冷冻异体手指复合组织移植后的骨关节病变观察

目的 研究自体Mu甲皮瓣游离移植包裹冷冻异体手指骨－关节－肌腱－腱鞘复合组织再造Mu，手指后，异体指骨关节病变发生的特点。方法 应用X线片和病理活检方法，对16例植入11个月－15年6个月，平均4年5个月的病变异体骨关节进行观察和评价。结果 异体骨关节病变过程可分早期（＜2年），中期（2－10年）和晚期（＞10年）。X线摄片分别显示软骨下骨虫蛀样缺损，骨关节吸收脱位和毁损。所有的病变骨关节中未见炎性细胞浸润，异体肌腱内见肌腱样细胞生长。结论 异体指骨关节病变严重程度与病程有关，其表现类似于失神经关节病变（Charcot关节病）。异体肌腱可长期存活。     

The difficult primary hip

Hip arthroplasty is a common orthopaedic procedure with proven long-term success and reliable results. A wide range of associated conditions may affect the outcome of the arthroplasty and the surgeon has to keep these in mind when planning the surgery. In this article, such situations are discussed and recommendations are drawn from the evidence available in literature.