微囊化大鼠肝细胞移植的组织学研究

目的 研究微囊化大鼠肝细胞腹腔移植后的存活情况以及组织学改变。方法 用二步法胶原酶门－腔静脉灌注法分离Wistar大鼠肝细胞,用Percoll梯度分离液纯化,海酸钠－氯化钡法微囊化包裹肝细胞,分别行腹腔注射移植,将纯化的肝细胞移植至SD大鼠体内（第1组）、微囊化包裹的肝细胞移植至SD大鼠体内（第2组）及Wistar大鼠体内（第3组）,观察移植后各组不同时间肝细胞存活率及其组织学变化。结果 （1）移植后第4、7d,各组间肝细胞存活率的差异均有显著性（P＜0.01）;移植后第14d,第2组与经3组间肝细胞存活率的差异无显著性;（2）移植后第4d开始,微囊周围出现纤维增生现象,第2组较第3组明显。结论 微囊化可为移植的肝细胞提供免疫屏蔽作用,从而提高肝细胞移植的存活率;微囊周围纤维增生可影响肝细胞的存活率。     

真皮替代物移植后的血管化过程及组织学变化的实验研究

目的了解不同种类真皮替代物移植后的血管化过程及组织学变化。方法将21只SD大鼠根据其皮下埋植不同的真皮替代物分为猪脱细胞真皮基质(sADM)组、人脱细胞真皮基质(hADM)组及人工真皮(Integra)组。于埋植后2、3、4、7、10、14、21、30、60、90、120、150、180d行移植物大体观察,采用免疫组织化学法观察移植物的血管化过程及组织学变化。结果大体观察术后各组大鼠创口周围皮肤无明显红肿及炎性反应,切口愈合良好,移植物与创面接触紧密。90d后各组移植物不易从体表触及。180d时,部分移植物面积缩小、厚度变薄甚至难以辨认。组织学观察移植术后2d起可见成纤维细胞、中性粒细胞、淋巴细胞等侵入移植物内,3d时与受床组织连接处可见长入的新生毛细血管芽。30—60d,移植物内形成丰富的血管网。150d后近似正常真皮结构。180d后部分移植物有不同程度吸收退化。结论3种真皮替代物移植后均能很快建立与受床组织的血液循环,并长时间存留于创面,但有一定程度的吸收退化。     

Preserved vascular homograft for revascularization of pediatric liver transplant: a clinical, histological, and bacteriological study.

BACKGROUND: Arterial or venous homografts are frequently implanted for vascular reconstruction in orthotopic liver transplantation (OLT). When fresh vascular homografts (VH) from the same donor were not available, VH from another donor preserved at 4 degrees C in Terasaki (Ter) solution (modified lymphocyte culture medium) were used. METHODS: The clinical results after implantation of Ter-stored VH versus fresh VH in the revascularization of pediatric OLT were studied retrospectively. Short- and long-term follow-up of vascular patency was carried out by doppler ultrasonography in each case. A histological and bacteriological study of nonimplanted VH stored at 4 degrees C in saline (Sal), Ter and University of Wisconsin (UW) solutions for various time periods (days 0-28) was also undertaken. RESULTS: Between 1989 and 1996, 21 iliac arteries and 21 iliac veins preserved in Ter solution (mean preservation time: 8 days; range 1-26) and 100 fresh VH (68 arteries and 32 veins) (preservation time: 8 hr, range 4-21) were used in pediatric OLT. Thrombosis rates were 0 of 21 for stored arteries vs. 7 of 68 (10%) for fresh arteries (NS) and 3 of 21 (14%) for stored veins vs. 3 of 32 (9%) for fresh veins (NS). Actuarial graft survival rates were similar in both groups. Histological analysis of stored, nonimplanted VH invariably showed endothelial destruction within 24-48 hr after procurement. The bacteriological study showed contamination rates of 14 of 25 (56%) for Sal-stored VH, 5 of 25 (20%) for UW, and 1 of 19 (5%) for Ter (Sal vs. UW and Sal vs. Ter: P<0.01; UW vs. Ter: NS). CONCLUSIONS: Ter-preserved cadaveric VH could be safely used in OLT despite early destruction of endothelium.     

A sequential study of histological and immunological changes in the skin after allogenic bone marrow transplantation

Histological and immunopathological studies were performed on serial skin biopsies from thirteen recipients of allogenic and two recipients of autologous bone marrow transplants. Marked dermoepidermal infiltration with Leu 2a+ (OKT8+) phenotype cells was found in two patients with severe graft-versus-host disease, but the infiltration did not precede clinical onset of the graft-versus-host disease. Absence of Langerhans cells was noted during the early posttransplant period in recipients of both allogenic and autologous transplantation. Intercellular epidermal staining with anti-DR was observed in three cases, without relation to graft-versus-host disease.     

同种异体带瓣大血管移植后钙含量的改变及其意义

目的 探讨同种异体带瓣大血管移植后钙含量的改变及其意义。方法 分为实验组、对照组和同基因组3组。分别于术后2、4、8、12、16周测定CD25和CD40的表达，光镜和电镜观察移植物并测定钙含量。与对照组和同基因组进行比较。结果 对照组CD25和CD40表达水平的高峰在移植后2周，此后逐渐回落，12周后维持在低水平。CsA组在移植后2～4周的表达明显低于对照组（P〈0．01），但8周后的表达水平与对照组差异无统计学意义（P〉0．05）。对照组的钙含量从4周开始升高，此后逐渐升高，在12周达到高峰并进入平台期。CsA组的钙含量显著低于对照组（P〈0．01）。实验组的内皮细胞脱落和-平滑肌细胞的坏死情况较对照组轻。结论 移植后钙含量的变化与免疫排斥互为因果，互相影响。     

Clinical outcome after coronary artery revascularization and lung transplantation

BACKGROUND: Presence of coronary artery disease (CAD) in otherwise eligible lung transplant candidates is considered a contraindication to lung transplantation. We reviewed the clinical outcome of our experience in lung transplant recipients with operable coronary artery disease and normal left ventricular function. METHODS: Medical records of all transplant recipients with coronary artery disease were reviewed. Data analyzed include demographics, coronary angiograms, coronary artery revascularization procedure, and clinical outcome after lung transplantation. RESULTS: Between April 1992 and August 2001, 354 lung transplant procedures were performed. Eighteen patients (5%) had significant CAD (greater than 50% stenoses). Six male patients (mean age 59 years) underwent percutaneous transluminal coronary angioplasty/stent and after lung transplantation all were discharged after a median hospital stay of 8.5 days. All recipients are alive at a median follow-up time of 14.5 months after their transplant. Twelve male patients (mean age 58 years) had combined coronary artery bypass grafting and lung transplantation. All recipients were discharged after a median hospital stay of 16 days. Nine recipients are alive at a median follow-up time of 7.5 months after transplant. One-year survival by the Kaplan-Meier method is 88% for the 18 patients with coronary artery disease who underwent revascularization and lung transplantation. CONCLUSIONS: Despite the traditional criteria of excluding all eligible transplant candidates due to coronary artery disease, coronary revascularization in select candidates with favorable anatomy and normal left ventricular function can allow patients to undergo lung transplantation with acceptable outcomes.     

Stability changes after cryosurgery in long tubular bones in correlation to histological results: an animal trial

Study question  Pathologic bone fractures in cryosurgery of bone tumors have been described in literature. This study utilizing a sheep model should prove the possible reduction of potential fracture while using a new miniature cryoprobe minimizing tissue damage and providing accurate control of the ablation process. Furthermore, postoperative histological changes should be investigated and the results correlated with the stability trials. Methods  In 24 sheep, ablation of the femur and the tibial bone on one side was carried out. Ablation of the right femur was limited to an area of 2 cm² with single cortical bone, whereas at the left tibia the whole proximal tibial plateau was included. The other side served as a control entity without cryoablation. After a period of 2, 4, and 6 months postoperative investigation of bending resistance of the femoral bone and of compression resistance of the tibial bone as well as histological findings were done in eight animals each. Results  After 2 months there was a significant difference (P < 0.05) regarding compression resistance between the treated and the contralateral tibia, whereas the bending resistance in the treated femur was slightly lower than on the contralateral side. After 4 and 6 months the cryo-treated part showed a tendency towards weakness. Histological findings showed bone necrosis with slight beginning repair after 2 months. Four and six months later, bone necrosis still existed with increasing development of woven bone and conversion into lamellar bone. Discussion  A thorough control of the freezing process and the low iatrogenous weakening of the bone due to placing the probe when modern miniature cryoprobes are used can minimize the risk of pathological postoperative fractures. However, at least 2 months after operation there is histological proof of bone healing with appropriate reduction of bone stability, which should be considered for the clinical application of this new technique.     

Impaired tubular reabsorption of magnesium after renal transplantation

Tubular reabsorption of magnesium (TRMg) was calculated from the values of plasma ultrafiltrable Mg and urinary Mg in 36 patients with transplanted kidneys. The study revealed a defect in TRMg in all investigated patients. The lowest TRMg values were found in patients with poor function of the transplanted kidneys. TRMg increased in relationship with the increment in glomerular filtration rate, nevertheless in the majority of the cases the TRMg values did not reach the values of healthy individuals.     

Pin-Hole changes after external fixation of tubular bone

Summary K-wire-pin-induced changes in cortical bone were studied in the intact rabbit tibiofibular bone. Using a bilateral external fixator two pairs of pins were applied under compression (10 kp), under distraction (10 kp), and in a neutralization sense. After defined intervals the pin-holes were investigated macroscopically and radiologically. Reactive and resorptive changes were present in 101 of 576 (17.5%) pin-holes, infection in 13 (2.3%) pin-holes. Changes were significantly more frequent in the distal pin-holes. The appearance of the pin-holes was not influenced by the type of external fixation used nor did the occurrence depend on the duration of metal implantation.

---

Zusammenfassung Es wird über experimentelle Untersuchungen im Bereich von Bohrdrahtaustrittsstellen am Kaninchenröhrenknochen berichtet. Hierfür wurde in die intakte Tibia ein Rahmenfixateur mit zwei Bohrdrahtpaaren unter axialer Kompression (10 kp), Distraktion (10 kp) und ohne Vorspannung als Neutralisationsrahmen eingebracht. Nach definierten Zeiträumen wurden die Bohrlöcher makroskopisch und radiologisch untersucht. Bei 101 von 576 Bohrlöchern (17,5%) fanden sich resorptive oder reaktive Knochenveränderungen. 13 Bohrlöcher (2.3%) waren manifest infiziert. Die Knochenveränderungen waren statistisch zu sichernd gehäuft an den distalen Bohrlöchern zu sehen. Die Häufigkeit der Veränderungen an den Bohrkanälen war weder von der Fixationstechnik noch von der Dauer der Implantationszeit der Bohrdrähte abhängig.

     

Substitution of an extensive defect of tissues after resection of the sternum in tumors

An original method of substitution of great defect of the soft tissues and osteochondral part of the chest wall after resection of the sternum for a malignant tumor is described. Operations were made on 4 patients. Favorable results were noted in all the patients. The terms of follow-up were from 6 to 25 months.     

Pin-hole changes after external fixation of tubular bone

K-wire-pin-induced changes in cortical bone were studied in the intact rabbit tibiofibular bone. Using a bilateral external fixator two pairs of pins were applied under compression (10 kp), under distraction (10 kp), and in a neutralization sense. After defined intervals the pin-holes were investigated macroscopically and radiologically. Reactive and resorptive changes were present in 101 of 576 (17.5%) pin-holes, infection in 13 (2.3%) pin-holes. Changes were significantly more frequent in the distal pin-holes. The appearance of the pin-holes was not influenced by the type of external fixation used nor did the occurrence depend on the duration of metal implantation.     

Functional and histological changes after myoblast injections in the porcine rhabdosphincter

OBJECTIVE: Transurethral ultrasound-guided injection of autologous myoblasts has recently been shown to cure urinary stress incontinence. In the present study, the dose-dependent changes in maximal urethral closure pressures after application of myoblasts were investigated in a porcine animal model. METHODS: Myoblast cultures were grown from a porcine muscle biopsy. The biopsy was enzymatically dissociated by using a modified cell dispersion technique. Single myoblasts in suspension were manually collected with a micropipette under microscopic control. Next a clonal myoblast culture was prepared. Before the cells were applied, fluorescence labelling (PKH) was used to assess integration of the injected myoblasts into the rhabdosphincter. With the help of a transurethral ultrasound probe (23 F, 11 MHz) and a special injection system, the myoblasts were injected into the rhabdosphincter of five pigs under direct sonographic control. Into two different areas of the rhabdosphincter, increasing different cell counts were injected (total volume 1.5 ml). At each area, 10 depots of 150 microl volume were injected all along the rhabdosphincter. The following cell counts were used: 1.5 x 10(6), 2.1 x 10(6), 4.2 x 10(6) (low range) 5.69 x 10(6), 8.1 x 10(6), 1.13 x 10(7), 1.6 x 10(7) (mid range) 2.26 x 10(7), 4.4 x 10(7), and 7.8 x 10(7) (high range). To avoid possible cell rejection, we immunosuppressed the pigs with daily cortisone (1g Solu Dacortin) because allogenic myoblasts were used. Urethral pressure profiles (UPPs) were measured before and 3 wk postoperatively before the pigs were put to sleep. The lower urinary tract was removed in all pigs for histological analysis. RESULTS: Histological examination of the specimens revealed that the injected cells had survived at the injection site and had formed new myofibres. Overall the UPP curves revealed dose-dependent changes. Statistically significant increased pressure values of up to more than 300% could be observed in all cases in which higher concentrations of cells had been applied. Increases were also noted in mid range concentrations although not to such a high extent (approximately 150%). Pressure values had even diminished (approximately 50%) after injecting the three lowest concentrations (1.5 x 10(6), 2.1 x 10(6), 4.2 x 10(6)). CONCLUSIONS: The present results show that the effects after application of myoblasts into the rhabdosphincter are dose-dependent.