A role for genomic instability in cellular radioresistance?

Summary Inherent cellular radioresistance plays a critical role in the failure of radiotherapy. Although the consequences of radioresistance are well known, the molecular, biological, and cellular bases of radioresistance remain a mystery. We propose that genomic instability, the increased rate of acquisition of alterations in the mammalian genome, can directly modulate cells' sensitivity to radiation. In particular, destabilization of chromosomes occurring as a consequence of genomic instability may result in enhanced plasticity of the genome. This increased plasticity of the genome allows cells to better adapt to changes in local environment(s) during tumor progression, or improve cell survival following exposure to DNA damage encountered during radiotherapy protocols, thereby contributing to radioresistant cell populations found in tumors both before and after radiotherapy.     

Biological activity of tissue flaps in the treatment of complicated irradiation wounds

Within the last ten years, 79 patients were treated for 114 chronically contaminated, intractable irradiation wounds using various methods of the modern plastic surgery. Radical excision of the devitalised contaminated tissue has been impracticable in 25 cases due to the risk of life-threatening complications or significant functional loss. Different types of flaps such as cutaneous, fasciocutaneous, musculocutaneous, split muscle, isolated vascularised fascia and greater omentum have been used. Despite the incomplete excision, 84% of wounds healed primarily. The essential factor for good wound healing seems to be the biologic activity (BA) of the flap's deep tissue layer that directly contacts the wound bed. BA includes density of the vascular net, ability of neovascularisation, plasticity and specific immunological capacities. It seems to be possible to classify the flaps according to the BA level. Tissue defects in which the chances for radical debridement are poor need the highest BA level in the flap reconstruction.Presented to the European Congress on Wound Healing and Skin Physiology, Bochum, Germany, 1992     

胫后侧逆行岛状筋膜蒂皮瓣修复踝周围软组织缺损

总结１９９３年５月－１９９８年８月,应用胫后侧二种逆行岛状筋膜蒂皮瓣多向转位修复踝部周围皮肤缺损的临床效果。利用胫后动脉肌间隙的穿动脉,腓动脉肌间隙支,腓动脉外踝支与腓肠浅动脉广泛吻合,设计胫后侧两种筋膜蒂皮瓣。     

Endoscopic vs conventional hernia repair from an immunologic point of view

Background: In this study we tried to estimate the local surgical trauma in patients undergoing endoscopic or conventional hernia repair via the changes in peripheral blood T cell subpopulations (i.e., T-helper 1 (TH1) and TH2 cells), recently shown to be recruited differentially to inflammatory sites. Methods: Cells were identified flow-cytometrically by intracellular cytokine staining on a single cell level in 30 patients undergoing conventional (Shouldice) or total extraperitoneal patch (TEPP) hernia repair. Results: The TH1 cells decreased postoperatively in Shouldice patients on an average of 20.8–31.4%, whereas in TEPP patients only a minor decline (mean, 7.8–9.2%) was observed. The TH2 cells did not change significantly in TEPP patients, and a small increase (mean, 7.7%) was detected in Shouldice patients. Conclusions: Our results suggest that the postoperative reduction in TH1 cells reflects local surgical trauma and can be helpful in evaluating different surgical procedures. When conventional and endoscopic hernia repair were compared, the latter proved less traumatizing. Received: 18 March 1998/Accepted: 24 July 1998     

A simplified laparoscopic technique for mesh placement in ventral hernia repair

The use of a large synthetic mesh for laparoscopic repair of significant ventral abdominal wall defects may be accompanied by technical difficulties resulting from improper orientation and positioning of the mesh over the defect. We suggest a technique based on initial fixation of the mesh center to the central point of the defect, and subsequent centrifugal attachment of the mesh to the abdominal wall. This technique is advantageous because it leads to precise orientation and positioning of the synthetic patch and to significant reduction of the time needed for its reinforcement over and around the defect. Received: 25 September 1998/Accepted: 27 November 1998     

Spatiotemporal progress of nerve regeneration in a tendon autograft used for bridging a peripheral nerve defect

We have previously shown that a tendon autograft from the rat tail can support regeneration across a gap in the continuity of the rat sciatic nerve. In this study, we characterized the spatiotemporal progress of regeneration in such a graft bridging a 10-mm defect in the sciatic nerve of the rat. Regeneration was assessed 7, 10, 14, or 18 days postoperatively, by immunocytochemistry for axons, Schwann cells, and macrophages and histochemistry for blood vessels. Axonal regrowth into the grafts showed an initial delay period of 6.8 days, whereafter axons grew at a rate of 1.0 mm/day. Schwann cells grew into the grafts from both the proximal and distal nerve segments, proximally just ahead of the axonal front. Macrophages were initially preferentially located at the periphery of the grafts, but gradually increased inside the grafts. Blood vessels entered the grafts from both the proximal and distal aspects of the severed nerve. The onset of vascularization appeared to coincide with axonal regeneration into the grafts.     

严重颅眶损伤的特点和救治

目的探讨严重颅眶损伤的特点和救治。方法回顾分析1990年1月～1997年12月收治的32例严重颅眶损伤患者的临床资料。结果32例严重颅眶损伤的临床特点为：脑损伤局限．意识障碍较轻,嗅神经、视审经损伤多见,脑脊液漏发生率高,颅眶畸形严重。结论应重视院前急救,尽早转送专科医院．除清除颅内血肿外,应注重视神经损伤、脑脊液漏和颅眶畸形手术处理．积极治疗并发症,有利于视神经功能的恢复,并能有效预防脑脊液漏引起的颅内感染．改善面部外观。     

Effects of interleukin-1, tumor necrosis factor-β, and forskolin on tissue plasminogen activator activity in human osteoblastic osteosarcoma cells

Summary The effects of interleukin-1 (IL-1), forskolin, and tumor necrosis factor (TNF-) on tissue plasminogen activator (t-PA) activity were studied in the human osteoblastic osteosarcoma cell line, G292. t-PA activity was measured in the cell media using the chromogenic substrate, S-2251. After a 24 hour incubation period, IL-1 increased t-PA in a dose-dependent manner. The effect of IL-1 at 10.0 U/ml was partially inhibited in the presence of indomethacin. Forskolin (1.0 M) increased t-PA activity after 24 hours with the effects of combined treatment of IL-1 (1.0 U/ml, 10.0 U/ml) and forskolin being apparently additive in nature. TNF- (10^-8–10^-7 M) also produced increased t-PA activity in the cell medial after a 24 hour incubation period. These results suggest that the cytokines, IL-1 and TNF-, can increase t-PA activity in G292 cells and that there is both a cAMP-dependent as well as a cAMP-independent pathway involved in the regulation of this osteoblastic cell function.     

Retropublic colpourethropexy with transabdominal anterior and/or posterior repair for the treatment of genuine stress urinary incontinence and genital prolapse

A new operative technique combining retropublic colpourethropexy with transabdominal internal anterior and/or internal posterior repair for the treatment of genuine stress incontinence (GSI) and genital prolapse is described in 75 cases. The overall success rate in correcting GSI was 92.0%, with a 94.8% success rate in the primary surgical group (n=58) and an 82.4% in the secondary group (n=17). Average follow-up has been 1.31 years (range 6 weeks–6 years). There was a 3.4% incidence of residual prolapse. Nine patients also underwent concomitant colpourethropexy. Overall surgical complications include febrile morbidity 4/75 (5.3%), wound infection 1/75 (1.3%), deep vein thrombosis 1/75 (1.3%) and partial ureteric obstruction 1/75 (1.3%). There were no statistically significant changes in multichannel urodynamic studies preoperatively and at 1 year following surgery. Onethird (2/6) of the GSI failures had low MUCP (<20 cm H₂O) prior to surgery and continued so at 1 year follow-up.EDITORIAL COMMENT: Genital prolapse is often present in patients who have GSI. If an operation is performed to correct the GSI, and those areas of weakness in the pelvic support system that are contributing to the genital prolapse are not treated, the genital prolapse will become more severe. In the operation which has been described, the colpopexy sutures will correct any cystourethrocele, and the removal of the wedge of tissue from the anterior superior vaginal wall will correct the cystocele. The removal of the wedge of tissue from the posterior superior vaginal wall will reduce the redundancy of the posterior vaginal fornix, but a culdeplasty of the Moschcowitz or Halban type is recommended to treat or prevent an enterocele and to place the vaginal apex in the hollow of the sacrum. Any coexistent rectocele must always be treated vaginally. If it is not treated, it will appear to be more advanced following elevation of the anterior vaginal wall by retropubic urethropexy and the anterior repair which has been recommended.Genital prolapse is best treated by a vaginal approach. When one must une an abdominal approach, ancillary procedures such as the authors have described should be considered. A bulbous upper vagina is ideal for childbearing but if the apical support system and vaginal wall is weakened it is predisposed to prolapse. If the surgeon, in operating for genital prolapse, which involves the upper vagina, will taper the vaginal apex and support it by obliteration of the cul-desac and shortening and reattachment of the uterosacralcardinal complex, postoperative prolapse will be less likely to recur.     

First experiences with HLA-matched corneal grafts in high risk cases

In highly vascularized corneas the number of graft failures caused by irreversible rejections is higher than in non- or slightly vascularized corneas. The importance of antigen compatibility is demonstrated, especially in these high risk cases.Ten highly vascularized corneas were grafted with HLA-matched donor material; only one reversible rejection was seen in this group.Nine non- or slightly vascularized corneas were grafted with donor material chosen at random. Retrospective HLA matching was performed. Three irreversible rejections were seen in this group. The number of HLA incompatibilities was high.