High resolution electron paramagnetic resonance imaging of biological samples with a single line paramagnetic label

The application of electron paramagnetic resonance imaging (EPRI) to obtain information from biological samples has been limited by the lack of ideal single line radical labels. The commonly used nitroxides exhibit multiple lines causing either hyperfine-based limitations in the maximum obtainable image resolution or hyperfine-based artifacts in the reconstructed image. The use of a novel single-line triarylmethyl paramagnetic label that enables marked enhancement in image quality and resolution is reported. This label exhibits a single line EPR spectrum that is sharp (linewidth ～60 mG in the absence of oxygen) and relatively stable in tissues. The potential of this label in enabling high resolution EPR imaging of biological samples was demonstrated in a series of phantoms and isolated biological organs such as the rat kidney. The images demonstrate that resolutions better than 100 μm could be obtained at L-band on samples of up to 20 mm in size.     

50岁以上肾移植的临床分析

自１９８９年１月～１９９５年１２月共施行同种异体尸肾移植术５５６例次，其中５０岁以上患者１８２例（３２７％），对这些患者的临床资料进行比较分析。结果显示：５０岁以上组１、３、５年的人／肾存活率分别为８３４％／７９３％、７７１％／７１１％和５４５％／４５５％，与４９岁以下组比较差异无显著性（Ｐ＞００５），急性排斥发生率并不比４９岁以下组高，并发症发生率尤其是感染发生率及致死率均高于４９岁以下组（Ｐ＜００５）。本资料说明，年龄不是肾移植的主要影响因素，感染和心血管并发症是主要的死亡原因和影响长期存活的因素。适应证的选择和术前充分透析，术后合理应用免疫抑制剂，定期复查及心、肝、肺功能的监护，是提高高龄肾移植患者长期存活的主要因素。     

Hemophagocytic syndrome and T-cell lymphoma after kidney transplantation: a case report

Lymphoma in immunocompromised transplant patients is a feared cause of morbidity and mortality. Superimposed on the lymphoma and the transplantation immunosuppression is a rare condition: hemophagocytic syndrome (HS). HS is characterized by fever, hepatosplenomegaly and lymphadenopathy, skin rashes, jaundice, coagulopathy, and phagocytosis of blood elements with pancytopenia. Here we describe a rare but fatal case of a kidney transplant patient who developed T-cell lymphoma and HS, without evidence of EBV replication. A short review of the diagnosis, treatment, and prognosis of HS is given. Received: 4 March 1997 Received after revision: 6 June 1997 Accepted: 30 June 1997     

Post-transplantation diabetes is better controlled after conversion from prednisone to deflazacort: a prospective trial in renal transplants

It is well known that long-term use of steroids plays a decisive role in the development of glucose intolerance and diabetes mellitus (DM). Deflazacort, an oxazoline derivative of prednisolone, has been introduced as a potential substitute for conventional steroids in order to ameliorate glucose intolerance. We initiated a randomized study of conversion from prednisone to deflazacort in kidney transplantation (Tx) recipients presenting with pre-Tx or post-Tx DM to ascertain whether or not the switch to deflazacort would ameliorate the diabetic state. Forty-two recipients in the conversion group were compared with 40 patients on prednisone (the control group) in a prospective manner. The dose reduction of insulin or oral blood glucose-lowering agents, the adequacy of glucose control, and the development of side effects were the criteria for evaluating outcome. In the conversion group, patients were switched to deflazacort at a dose ratio of 6 mg deflazacort to 5 mg prednisone. During the mean follow-up period of 13.2 months, neither graft dysfunction nor acute rejection developed in the conversion group. Improvement in blood glucose control in the conversion group was noted. When the conversion group was stratified into pre- or post-Tx DM, promising effects were clearly evident in the post-Tx DM patients. More than 50 % dose reduction of blood glucose-lowering agents was possible in 42.3 % of post-Tx DM patients. In conclusion, it was readily possible to control blood glucose better in post-Tx DM recipients without seriously affecting the immunosuppressive activity after conversion to deflazacort. Received: 20 August 1996 Received after revision: 25 November 1996 Accepted: 6 December 1996     

狗脊髓截除自体隐神经大网膜移植的初步观察

实验用6只狗于T13处切除脊髓8mm，局部用隐神经、大网膜移植。对照组6只狗单纯切除脊髓8mm。术后3个月、6个月实验组动物全部恢复到C／Ⅲ级功能，组织学切片见移植神经有不同程度存活，可记录到股四头肌、胫前肌电位。对照组动物仅达到0／0～A／I织功能，组织学切片见脊髓缺损处为结缔组织，诱电位波形消失。分析了影响脊髓神经功能恢复的原因。     

Chondrocyte-seeded hydroxyapatite for repair of large articular cartilage defects. A pilot study in the goat

The aim of this study was to evaluate the potential for restoration of a large cartilage defect in the goat knee with hydroxyapatite (HA) loaded with chondrocytes. Isolated chondrocytes were suspended in fibrin glue, seeded on top of the HA, and then the composite graft was implanted in the defect. After transplantation, cell behaviour, newly synthesised matrix and the HA–glue interface were assessed histologically after 2, 4, 12, 26 and 52 weeks. Special attention was paid to the incorporation process of HA in the subchondral bone and interactions between this biomaterial and the fibrin-glue–chondrocyte suspension.

Chondrocytes in the glue proved to survive the transplantation procedure and produced new metachromatically stained matrix two weeks after implantation. The glue–cell suspension had penetrated the superficial porous structure of the HA. Four weeks after surgery, islands of hyaline-like cartilage were observed at the HA–glue interface. A layer of fibrous tissue was formed surrounding the HA graft, resulting in a relatively instable fixation of the HA in the defect. This instability of the graft in the defect, possibly together with early weight bearing, resulted in a gradual loss of the newly formed hyaline cartilage-like repair tissue. Progressive resorption of the HA occurred without any sign of active bone remodelling from the host site. One year after surgery part of the defect which extended down to the cancellous bone had been predominantly restored with newly formed lamellar bone. Only small HA remnants were still present at the bottom of the original defect. Resurfacing of the joint had occurred with fibrocartilaginous repair tissue.

The absence of adequate fixation capacity of the HA near the joint space resulted in a relative instability of the graft with progressive resorption. Therefore, HA is not a suitable biomaterial to facilitate the repair of large articular cartilage defects.     

山莨菪碱防治甘油所致急性肾功能衰竭的实验研究

在１２９只ＳＤ大鼠的实验中动态观察了山莨菪碱对甘油所致急性肾功能衰竭时不同时期的Ｂｃｒ，ＢＵＮ，ｐＨ病理改变及死亡率的影响，结果表明：山莨菪碱能降低ＡＲＦ第５天大鼠死亡率以及Ｂｃｒ，ＢＵＮ水平。改善病理损害，对ＡＲＦ起到预防及治疗效果，山莨菪碱的预防效果优于治疗效果，预防是ＡＲＦ防治的关键，但山莨菪碱在治疗过程中要引起“冲刷综合征”导致洗脱性酸中毒，应引起注意。     

肾脂肪肉瘤(附三例报告及文献复习)

本文报道三例肾脂肪肉瘤,并结合文献复习,讨论了其病理,临床表现、影像学特征、诊断和治疗。     

Longitudinal study of the frequency of cytotoxic T cell precursors in kidney allograft recipients

Clonal deletion or inactivation of donor-specific alloreactive cells are important mechanisms that are believed to account for acquired immune tolerance in allograft recipients. Serial assessment of precursor cytotoxic T lymphocyte frequencies (CTLpf) by limiting dilution analysis (LDA) provides information at the clonal level on changes in the alloimmune response of graft recipients. We performed a longitudinal study of 15 cadaveric kidney recipients before and every 3 months throughout the first year after transplantation (Tx). Pre-Tx values of donor CTLpf showed high interindividual variability without a predictive value for the clinical outcome. All patients with well functioning kidneys had decreased CTLpf at 3 months post-Tx in comparison with pre-Tx values. This decrease was donor-specific in four patients and was permanent in two cases throughout the study. Most patients presented decreased anti-donor CTLpf values from 6 to 9 months, whereas a partial recovery of donor CTLpf was observed in three patients. Reversible acute rejection was diagnosed in three patients, and it was associated with a marked increase in anti-donor CTLpf, returning to pre-Tx values by 9 months post-Tx. In addition, one patient with chronic rejection displayed a transient increase in CTLpf 6 months after Tx. The results of this sequential study indicate the establishment of a state of either hyporesponsiveness or functional clonal inactivation, transient or permanent, which could facilitate allograft acceptance.     

低温保存同种心脏瓣膜活性及临床应用的研究

取正常成人心脏瓣膜３６个，置于低浓度广谱抗生素的营养液（ＲＰ－ＭＩ１６４０细胞培养液）中灭菌４８ｈ，－８０℃冰箱初冻，置于液氮中长期保存。灭菌前后瓣膜细菌培养阴性率分别为９４．３％和１００％，解冻后经光镜、电镜检查证实瓣组织细胞结构正常，组织培养葡萄糖消耗率测定示瓣组织存活良好。临床同种心脏瓣膜原位移植３例，随访６～３０个月，瓣功能良好