血管植入神经移植段修复神经缺损的实验研究

54只大白鼠随机分三组，用不同方法修复坐骨神经缺损，术后60天和90天取材，作电生理、组织学和电镜观察的比较，结果表明：游离神经移植＋血管植入方法和带血管蒂神经移植效果同样好，二者均显著优于单纯游离神经移植。     

Morphology of hydrogel implants used for refractive keratoplasty

The pathology of 14 keratophakia procedures in nine nonhuman primates using various hydrogel lenses as donor lenticles is presented. The lenses were treated as if they were human donor corneas using currently practiced keratophakia procedures. This included microkeratome resection of the recipient cornea, staining of the lenses before cryolathing and, in most instances, lathing according to a modified computer program after which the lenses were inserted into the previously dissected recipient lamellar bed. There was no histologic evidence of an inflammatory reaction to the hydrogels. The major pathologic feature was the presence of activated keratocytes lining the dissected intrastromal pockets.     

Controlled Synthesis and Characterization of Poly[ethylene‐block‐(L,L‐lactide)]s by Combining Catalytic Ethylene Oligomerization with “Coordination‐Insertion” Ring‐Opening Polymerization

Model poly[ethylene‐block‐(L ,L ‐lactide)] (PE‐block‐PLA) block copolymers were successfully synthesized by combining metallocene catalyzed ethylene oligomerization with ring‐opening polymerization (ROP) of L ,L ‐lactide (LA). Hydroxy‐terminated polyethylene (PE‐OH) macroinitiator was prepared by means of ethylene oligomerization on rac‐dimethyl‐silylen‐bis(2‐methyl‐benz[e]indenyl)‐zirconium(IV)‐dichloride/methylaluminoxane (rac‐MBI/MAO) in presence of diethyl zinc as a chain transfer agent, and subsequent in situ oxidation with synthetic air. Poly[ethylene‐block‐(L ,L ‐lactide)] block copolymers were obtained via ring‐opening polymerization of LA initiated by PE‐OH in toluene at 100 °C mediated by tin octoate. The formation of block copolymers was confirmed by ¹H NMR spectroscopy, fractionation experiments, thermal behavior, and morphological characterization using AFM and light microscopy techniques.

     

Histopathology and clinical behavior of polysulfone intracorneal implants in the baboon model. Polysulfone lens implants

The authors performed 13 myopic intracorneal polysulfone implants in a baboon model using two different implant designs. In the initial series, they used eight lenticules 5 to 6 mm in diameter with a central thickness greater than 0.15 mm. These failed 6 days to 6 months after surgery. The second series of five implants 4 to 5 mm in diameter with a thinner central thickness and improved edge design was better tolerated initially, but only two of five corneas remained clear 27 months after surgery. Clinical failure was associated with corneal neovascularization and opacification posterior to the implant or aseptic necrosis of the cornea overlying the implant. In most eyes, the anterior stroma was hypocellular anterior to the implant. Numerous vacuolated keratocytes and scattered eosinophils were detected posterior to the implant. In one case, lipid deposition was confirmed posterior to the lenticule. The authors conclude that solid polysulfone intrastromal implants are not biocompatible with the baboon cornea.     

Delayed corneal wound healing following radial keratotomy

Four human corneal specimens obtained 5 to 47 months following radial keratotomy were evaluated by correlative microscopy. Repeat radial keratotomies had been performed in two cases. We documented gaping keratotomy incisions, epithelial plugs, and epithelial-lined incisions. In all cases, Bowman's layer was malapposed with slight to moderate fibroblastic activity at the incision sites. Epithelial and endothelial radial ridges were seen in two cases. No endothelial damage was seen under the radial incisions. The morphological evaluation of these specimens show the potential for a poor wound-healing response when corneas with previous corneal surgery and/or pathologic states undergo radial keratotomy.     

3，4－二甲氧基苯甲酰哌嗪衍生物的合成及其正性肌力作用初探

作者对新型正性肌力药维司力农（Ｖａｓｎａｒｉｎｏｎｅ，即ＯＰＣ－８２１２）结构进行改造，合成了十二个３，４－二甲氧基苯甲酰哌嗪新衍生物（ＴＭ－１～ＴＭ－１２），其结构经红外光谱、质谱、核磁共振氢谱及元素分析确证。将目标化合物ＴＭ－１、ＴＭ－２及中间体（３）（ＶＰＡ）作药理试验，结果显示它们对豚鼠离体心房均有正性肌力作用，其中ＯＰＣ－８２１２及ＶＰＡ与二甲亚砜对照有显著性差异（Ｐ＜０．０５）。进一步的药理试验正在进行中。     

Electron microscopic features of never-worn soft contact lenses: deposits or artifacts?

Since scanning electron microscopy (SEM) is commonly used to evaluate hydrophilic lens deposits, it is important to know what artifacts are induced by the various techniques used to process the lenses. We performed scanning electron microscopy (SEM) using never-worn lenses with hydrations from 38.6% to 71%. Each lens was taken from its vial of factory-sealed, sterile-preserved saline and processed for SEM examination using liquid CO2, freon critical point drying, or air drying with or without alcohol dehydration. The lenses revealed abnormal surface structures occasionally resembling deposits reported on worn soft contact lenses. Varying degrees of gas pockets and surface wrinkling were seen. Individual polymers and lens hydration reacted differently to the various techniques of processing. Of the four methods evaluated, air drying without alcohol dehydration induced the least artifacts.     

Alloplastic implants for the correction of refractive errors

Convex-shaped, hydrophilic lenticles of various water content were implanted into microkeratome-dissected corneal pockets in a baboon model. Freshly trephined, cryolathed, and factory-lathed hydrogels were evaluated for periods exceeding 15 months, documenting clinical response, corneal curvature shifts, and morphologic features. Previously implanted hydrogels were subsequently removed, documenting the reversibility of the procedure while allowing the corneas to return to their preoperative condition. Various alloplastic materials were then reimplanted into the same intrastromal pockets. Medium and high water content lenses produced good results without affecting the recipient cornea, whereas thick or low water content materials extruded or produced severe anterior segment inflammation. The use of medium and high water content, convex-shaped lenticles for the correction of aphakia is possible using current techniques.