Peripheral nerve grafts lacking viable Schwann cells fail to support central nervous system axonal regeneration

Summary Peripheral nerve grafts were implanted bilaterally into the diencephalon of adult hamsters. One graft segment contained both viable Schwann cells and their basal lamina tubes. The Schwann cell population in the second graft segment was killed by freezing prior to implantation. Seven weeks after graft implantations, the extracranial end of each graft segment was exposed, transected and labelled with a fluorescent tracer substance. One week after the labelling procedure each animal was perfused and the diencephalon and midbrain were examined. Ultrastructural analyses of both types of graft demonstrated the persistence of the Schwann cell-derived basal lamina tubes. Retrogradely labelled neurons were found in all cases in which an intact graft remained in place for two months, but were seen in only one case with a frozen graft. Large numbers of myelinated and unmyelinated axons were seen within the intact grafts, but no axons were found in the previously frozen grafts. These results indicate that lesioned CNS axons are able to regenerate vigorously when provided with an environment which includes viable Schwann cells. But, CNS axons regenerate less well, if at all, when Schwann cells are absent. Further, it appears that Schwann cell-derived basal lamina tubes, when isolated from their parent cells, are insufficient to initiate or sustain CNS axonal regeneration.This material is based upon work supported by the National Science Foundation under grant BNS-8416911     

Hydrogels in endovascular embolization. II. Clinical use of spherical particles

In this study we report the results of clinical experiments, obtained with spherical particles made from poly(2-hydroxyethyl methacrylate) used in the embolization of arteriovenous anastomoses, in the suppression of pulmonary haemorrhage and haemoptysis and in the occlusion of some other arteries. So far we have used these particles in the treatment of 187 patients. It must be stressed that the advantage of spherical particles consists in the simplicity of their introduction into the blood vessel through a catheter, while in the blood vessel itself the particle swells in blood still more, when compared with the particle size in saline. This results in an immediate and permanent haemostatic effect. No revascularization occurs.     

Hyper-reactivity to amphetamine in rats with dopaminergic grafts

Summary Rats with dopaminergic lesions were subsequently given grafts of dopaminergic (DA) neurons in various brain regions, and later tested for behavioral reactivity to amphetamine. Two experimental situations were used. 1) Amphetamine-induced circling behavior was measured in animals with unilateral lesion of the nigrostriatal pathway implanted with intrastriatal grafts, 2) locomotor activation by amphetamine was measured in animals with bilateral lesions and grafts in the nucleus accumbens. In both situations, behavioral overcompensation was observed after grafting. Ipsilateral circling, which is caracteristic of a unilateral lesion of the nigrostriatal pathway, gave way to contralateral circling, and locomotor activity was restored to levels above those observed for control animals. This behavioral overcompensation is a reflection of hyperreactivity of grafted animals to amphetamine: they were found to respond to much lower doses than controls and the effect of the drug lasted longer. This enhanced response does not seem to be due to post-synaptic hypersensitivity, but rather to hyper-reactivity of the grafted neurons themselves to amphetamine. The mechanism of this phenomenon, which seems to be a general property of grafted DA neurons is discussed.     

Short-termin vivo stability of endothelial-lined polyester elastomer and polytetrafluoroethylene grafts

A fibronectin substrate will significantly enhance the strength of endothelial cell attachment on grafts constructed of polyester elastomer (PE) and polytetrafluoroethylene (e-PTFE). This experiment was undertaken to determine the short-termin vivo stability of endothellum on these fibronectin coated surfaces. Eight mongrel dogs underwent bilateral carotid artery replacement with both graft materlals. All grafts were inoculated with 2,000 cells/mm² using cultured autogenous venous endothelium labelled with Indium-111-oxine. The Indium-111 label in the grafts was measured immediately prior to implantation, after 1 hour ofin vivo perfusion, and at explantation after 24 hours. The percentage of inoculated cells attached to the grafts before perfusion was simillar for both materials, 93.3±3.0% versus 92.2±7.2%, for PE and e-PTFE respectively. All grafts were patent at one hour after implantation. PE grafts were found to have 93.8±3.9 % of the attached cells present at one hour while e-PTFE grafts had only 54.5 ± 10.8 % remaining, p<.001. After 24 hours, 5/8 (62.5%) e-PTFE grafts and 2/8 (25.0 %) PE grafts remained patent, p=.13. Of the patent grafts however, endothelial cell retention was still superior on the PE grafts with 78.0±0.6% of the attached cells remaining compared to only 24.5±6.1% on e-PTFE, p<.001. Occluded PE grafts had fewer cells remaining at 24 hours than patent ones, 78.0±0.6% versus 31.1±32.8%, respectively, p=.13. Histologically, patent PE grafts demonstrated nearly confluent endothelial monolayers while e-PTFE had patches of endothelial cells surrounded by, a platelet-fibrin carpet. We conclude that short-term patency appears to be determined by the extent of endothelial retention on PE but not e-PTFE.     

The bilateral conchal cartilage graft: A new technique in augmentation rhinoplasty

The most common procedures to reconstruct a severe saddle-nose deformity are autogenous costal cartilage, iliac bone grafting, or Silastic implants. Each of them has its specific disadvantages. As an alternative solution, an autogenous bilateral conchal graft in sand-wich technique is described. A 3-layer graft for the dorsum and a 2-layer graft to support the depressed columellar-tip area grants a more natural and elastic reconstruction of the nasal framework. The conchal grafts are taken by an incision made on the preauricular surface of the ear. How to plane the curved grafts by meticulous cross-hatching and to immobilize them in the recipient area by transcutaneous suturing is demonstrated.Presented at the VIII International Congress of Plastic and Reconstructive Surgery, Montreal, Canada, June, 1983     

50例冠状动脉搭桥术的临床研究

目的：观察冠状动脉搭桥术的临床疗效。方法：选择经内科治疗仍反复心绞痛发作或不适于PTCA等治疗的冠心病人50例,均在体外循环,心脏停跳下行冠状动脉搭桥术,选用的血管桥包括大隐静脉,乳内动脉和桡动脉,共搭145根桥,平均每例2．9支桥,5例同时行室壁瘤切除或成形术。结果：治愈48例,死亡2例,48例长期随访,效果良好,结论：对有冠脉搭桥指征的病人行搭桥手术,疗效安全可靠, 远期效果好。     

Development and Validation of Scoring Indication of Surgical Clipping and Endovascular Coiling for Aneurysmal Subarachnoid Hemorrhage from the Post Hoc Analysis of Japan Stroke Data Bank

There are no scoring methods for optimal treatment of patients with aneurysmal subarachnoid hemorrhage (aSAH). We developed a scoring model to predict clinical outcomes according to aSAH risk factors using data from the Japan Stroke Data Bank (JSDB). Of 5344 patients initially registered in the JSDB, 3547 met the inclusion criteria. Patients had been diagnosed with aSAH and treated with surgical clipping or endovascular coiling between 1998 and 2013. We performed multivariate logistic regression for poor outcomes at discharge, indicated by a modified Rankin Scale (mRS) score >2, and in-hospital mortality for both treatment methods. Based on each risk factor, we developed a scoring model assessing its validity using another dataset of our institution. In the surgical clipping group, scoring criteria for aSAH were age >72 years, history of more than once stroke, World Federation of Neurological Societies (WFNS) grades II–V, aneurysmal size >15 mm, and vertebrobasilar artery (VBA) aneurysm location. In the endovascular coiling group, scoring criteria were age >80 years, history of stroke, WFNS grades III–V, computed tomography (CT) Fisher group 4, and aneurysmal location in the middle cerebral artery (MCA) and anterior cerebral artery (ACA). The rates of poor outcome of mRS score >2 in an isolated dataset using these scoring criteria were significantly correlated with our model’s scores, so this scoring model was validated. This scoring model can help in the more objective treatment selection in patients with aSAH.     

腔内血管技术在肝静脉回流障碍综合征治疗中的应用

目的：探索一种简单、安全、有效的治疗肝静脉回流障碍（Budd-Chiari)综合征的新方法。方法：在11例肝静脉回流障碍综合征患中,应用经皮穿刺下腔静脉气囊扩张成形术治疗获得成功后,有9例患同时置入血管内支架。3例肝静脉完全闭塞在下腔静脉腔内治疗术成功后1周内行肠系膜上静脉－下腔静脉间人造血管“H”型分流术。结果：11例患,除1例在腔内治疗后出现轻度心功能不全表现外,无手术并发症,术后随访6－35个月,血管内支架通畅、无移位,分流血管无血栓栓塞,门脉高压症状明显缓解,患生活质量提高。结论：腔内血管技术是肝静脉回流障碍综合征的首选治疗方法。     

电解可脱卸弹簧圈栓塞治疗颅内破裂动脉瘤的疗效及影响因素

目的：探讨电解可脱卸弹簧圈（Guglielmi detachable coil,GDC）栓塞治疗颅内破裂动脉瘤的近期疗效及相关影响因素。方法：应用GDC栓塞治疗123例157枚动脉瘤,分析动脉瘤几何形态学、病情严重程度对栓塞效果及临床治疗的影响。结果：Hunt-Hess分级Ⅰ-Ⅱ级患中,预后良好（GOS＞3分）为100％,Ⅲ、Ⅳ-Ⅴ级患中分别为95．0％、76．0％;窄颈动脉瘤完全栓塞率、大部栓塞率及部分栓塞率分别为92．4％、5．7％、1．9％,宽颈动脉瘤中分别为80．8％、13．5％、5．8％,大动脉瘤的疗效明显低于小动脉瘤。结论：动脉瘤的栓塞程度不仅与瘤颈大小有关,还受瘤体大小的影响。而临床预后与Hunt-Hess分级呈负相关。