The infeasibility of using ten-ring irradiated grafts for tracheal allotransplantation even with omentopexy

In our previous study, we demonstrated that high-dose ⁶⁰Co irradiation was able to prevent rejection of canine tracheal allografts. To determine the maximum possible length of these grafts, in the present study we attempted to transplant five-ring and ten-ring tracheal allografts in two groups of five dogs each. Either five or ten rings were excised from donor tracheas and irradiated with 100,000 cGy of ⁶⁰Co. The irradiated tracheal grafts were transplanted to replace either five- or ten-ring sections of the mediastinal tracheas removed from the recipient dogs. The grafts were covered with omental pedicles and no immunosuppressants were used. Graft incorporation was achieved in four of the five dogs in the five-ring group, and three of these dogs survived for more than 700 days. However, four of the five animals in the ten-ring group died from tracheostenosis accompanied by ischemia within 3 weeks. These findings demonstrate the impossibility of performing ten-ring tracheal allotransplantation using irradiated grafts, even with omentopexy.     

Iatrogenic Creutzfeldt–Jakob disease subsequent to dural graft: persisting risk after 1987

The first case of Creutzfeldt-Jakob disease (CJD) related to the use of a dura mater graft of cadaveric origin was identified in 1987 and this procedure is now considered as one of the main causes of iatrogenic CJD. Although the decontamination procedure for the preparation of graft material was modified, the product was withdrawn from the market in many countries a few years later and replaced by synthetic material. In this context, two patients treated in our institution developed CJD following a cadaveric dural graft performed after cerebral and lumbar trauma. Their clinical presentation, showing predominant cerebellar symptoms, late deterioration and myoclonic jerks, and a rapid disease course until death, was similar to that of previously reported cases involving the iatrogenic form. As the graft for one of the patients was performed in 1991 (several years after modification of the decontamination procedure), this fourth reported case suggests that the risk of iatrogenic CJD may have persisted in some patients treated after 1987, when grafts of cadaveric origin were totally abandoned.     

Repair and reconstruction of peripheral nerve injuries

Axonal regeneration after transection is a complex biological process. It is not merely a process of tissue repair, but rather of cellular repair of a large number of nerve cells. Regeneration involves restoration of the original morphology of each single cell, rather than proliferation. Techniques in microneurosurgical reconstruction of peripheral nerve injuries have improved over the last two decades, with subsequent improvement in functional results. Nerve autografts are now routinely used to guide the regrowth of the proximal nerves to distal nerve segments. However, the limited source of expendable cutaneous nerves restricts the use of nerve grafting techniques and is associated with significant morbidity. With extensive injuries there is an insufficient quantity of nerve autograft material to facilitate optimal repair. In future, the use of artificial conduits or nerve allografts could provide a limitless source of material to reconstruct otherwise irreparable traumatic nerve injuries. Establishment of appropriate strategies to suppress host-immune reaction or donor antigenicity would facilitate clinical allogeneic nerve transplantation. Guest lecture presented at the 69th Annual Meeting of the Japanese Orthopaedic Association in Tokyo on April 13, 1996.     

用酸蚀法提高纯钛与光固化冠桥树脂粘结强度的研究

目的：研究用酸蚀法提高钛与光固化复合树脂剪切粘结强度的可行性，并观察表面粗糙度与剪切粘结强度之间的关系。方法：采用不同浓度的酸蚀剂对钛铸件表面进行酸蚀，并与artglass光固化复合树脂进行粘结，以单纯喷砂组为对照，比较剪切粘结强度的差异。对酸蚀后及剪切试验后的金属表面进行扫描电镜观察，并测定其表面粗糙度。结果：用酸蚀法可以显著提高钛与复合树脂的粘结强度，HF浓度为4％时粘结强度最高。表面粗糙度随酸蚀剂的浓度增高而下降。结论：纯钛铸件用酸蚀法处理后可以获得较高的粘结强度，HF酸浓度以4％为宜。表面粗糙度对粘结强度不起决定性作用。     

Deltoid flap combined with fascia lata autograft for rotator cuff defects: a histologic study

The purpose of this study was to compare the histological characteristics of an autogenous fascia lata graft alone and a fascia lata graft combined with a deltoid flap in the reconstruction of rotator cuff tears. Ten New Zealand white rabbits were divided into two groups. Infraspinatus tendon defects (1 × 1 cm) were created in each animal. Reconstruction consisted of either a fascia lata graft alone or a fascia lata graft combined with a distally based deltoid flap. At 3 months, tissue harvest and histological analysis was performed. Compared to the fascia lata graft alone, there was significantly increased remodeling activity and neovascularization in the group that included a deltoid flap. Also, there was pronounced interdigitation at the graft/flap interface in the latter group. A mutually beneficial relationship may exist when an autogenous fascial graft is combined with a functional deltoid flap for reconstructing large rotator cuff defects.     

Liver and intestine transplantation

The most significant development in liver transplantation in the USA over the past year was the full implementation of the MELD- and PELD-based allocation policy in March 2002, which shifted emphasis from waiting time within broad medical urgency status to prioritization by risk of waiting list death. The implementation of this system has led to a decrease in pretransplant mortality without increasing post-transplant mortality, despite a higher severity of illness at the time of transplant.
The trend over the last few years of rapidly increasing numbers of adult living donor liver transplants was reversed in 2002 by a decline of more than 30% in the number of these procedures. In 2002, a greater percentage of women received livers from living donors (43%) than deceased donors (34%), possibly because of size considerations.
From 1993 to 2001, the waiting list increased more than sixfold, from 2902 patients to 18 047 patients. For the first time since 1993, the waiting list size decreased in 2002, dropping 6% to 16 974 candidates. The percentage of temporarily inactive liver candidates also increased from 2001, thus the net decrease in the active waiting list for 2002 was 12%. This may reflect a trend toward less pre-emptive listing practices under MELD.
Intestine transplantation remains a low-volume procedure limited to a few transplant centers and is still accompanied by significant pre- and post-transplantation risks. As this procedure matures, its application may increase to include recipients at an earlier stage of their disease with better likelihood of success.     

The “graft versus leukemia” effect under conditions of mixed chimeric hemopoiesis

The “graft versus leukemia” effect can be induced in (C57B1/6×DBA) F₁ mice by two transplantations of cell suspensions containing bone marrow cells and splenocytes of (CBA×C57B1/6) F₁ mice and an injection of cyclophosphamide. The recipients of cell allotransplants were characterized by mixed chimeric hemopoiesis. These data outline a new approach to induction of the graft versus leukemia effect, requiring no complete elimination of the recipient's hemopoiesis and characterized by a low probability of lethal graft-versus-host reaction. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 5, pp. 562–565, May, 1997     

小剂量多克隆抗体预防移植肾急性排斥反应

目的：探索能减少并发症，减轻病人经济负担，有效预防移植肾急性排斥反应的多克隆抗体的合理使用方案。方法：选择肾移植患者８０例，根据使用多克隆抗体的时间不同分３组，观察病人血ＣＤ３＋细胞数变化、急性排斥反应及并发症发生率，作前瞻性研究。结果：３组病人急性排斥反应率，术后５ｄ内ＣＤ３＋细胞数无统计学差异，而使用抗淋巴细胞免疫球蛋白（ＡＬＧ）时间较长者，术后６ｄ后ＣＤ３＋细胞数少于其他组，巨细胞病毒（ＣＭＶ）病及一般感染率明显高于其他组。结论：术后间歇使用小剂量ｔｉｅｎｔｓ′ＡＴＧ及术后连续３～６ｄ使用常规剂量ＡＬＧ是一种有效、安全、价廉的免疫抑制方案。     

先天性齿槽突裂整复术(附10例报告)

应用自体髂松质骨髓颗粒植入整复10例单侧上颌齿槽突裂,并关闭口鼻瘘。10例伤口一期愈合,术后观察3~6个月,外观改善明显,X线检查有明显骨形成,骨密度近似正常骨组织,两者间无明显界限。     

Evaluation of an aortic stent graft for use in surgery on esophageal cancer involving the thoracic aorta

Objective: The purpose of this experimental study was to investigate whether aortic stent grafting can be applied to the treatment of an esophageal cancer involving the thoracic aorta. Methods: The canine thoracic aorta was partially resected without aorta being clamped after emplacement of an endovascular stent graft. Study I; The aortic whole layer of 1 cm in length and 1/4 of the circumference was resected and was covered by a free fascia patch of the abdominal rectal muscle immediately after stent graft placement. Study II; The aortic adventitia and the outer half of the media of the same size was resected on day 3, 7,14, 21, and on day 28, after the stent graft placement. The resected portion was covered by the free fascia patch in half experimental dogs, and was uncovered in the others. Study III; The aortic adventitia and the outer half of the media of 1 cm in length and 1/2 of the circumference was resected and was uncovered on day 7 after stent graft placement. Histological examinations were performed on day 28 and at one year after aortic resection. Results: The aortic wall could be resected in all cases with no complication, except in resection of 1/2 the circumference where the aorta had become narrow. There was no difference in healing of the resected portion of the aorta between with and without fascia covering. Conclusion: An aortic endovascular stent graft could be applied to surgery for an esophageal cancer involving the aorta.