兔同种胎软骨移植的组织和细胞学观察

目的在于观察兔同种胎软骨移植后的不同时期组织和细胞学变化，为临床应用提供可靠依据。所用方法为将妊娠２６天的新鲜兔胎软骨移植到２７只成年同种家兔的面部骨膜下，在不同时期切取标本进行光镜和电镜观察。结果显示，兔胎软骨移植后的生长方式类似于一般软骨间质生长和软骨膜下生长，在移植后半年，兔胎软骨的生长有停止倾向。作者认为，新鲜胎软骨移植可以作为骨诱导材料和支架材料供临床使用。     

Anatomy and functional aspects of the rotator interval

The anatomy of the region between the supraspinatus and subscapularis tendons, called the rotator interval, was studied in 22 shoulders of 12 cadavers. Its function was then examined by sequential cutting of tendon or rotator interval structures. The rotator interval was found to be composed of parts of the supraspinatus, subscapularis, coracohumeral ligament, superior glenohumeral ligament, and glenohumeral joint capsule. A medial part composed of 2 layers was defined and distinguished from a more lateral part composed of 4 layers. The most superior 3 layers of the lateral part formed a fibrous plate. The medial part was found to primarily limit inferior translation and, to a lesser extent, external rotation. The fibrous plate of the lateral part of the rotator interval mainly limited external rotation of the adducted arm. The coracohumeral ligament played a key role in external rotation as well as in inferior translation.     

Histological changes following epidural injection of midazolam in the neonatal rabbit

Midazolam can produce antinociceptive effects when used via intrathecal or epidural routes. Neurotoxicity studies are scanty especially for neonates. The aim of this study was to carry out electron microscopic (EM) examinations in the neonatal rabbit to determine the histological effects of epidural midazolam on spinal cord. Twenty white New Zealand neonatal rabbits were randomly assigned to three groups receiving single dose of 0.9% saline (Group I; Control, n =4), 0.9% saline titrated to pH=3.9 by addition of hydrochloric acid (Group II; n =6), midazolam 250 μg·kg⁻¹ (Group III; n =12) epidurally. Half of each group were sacrificed on the second day and the remainder on the seventh day and spinal cord sections were evaluated by EM. Control group displayed normal histology on grids. Group II and II showed a variable degree of neurotoxic effects such as degeneration of vacuoles, cytoplasm and neurofilaments, disruption of myelin sheaths, lysis of cell membranes, perivascular oedema, pyknosis of nuclei. The toxic effects of acidic saline and midazolam are similar, in view of these results the epidural use of acidic midazolam (commercially available preparations) in neonates should be avoided.     

Effects of estrogen on nitric oxide synthase and histological composition in the rabbit clitoris and vagina

We investigated the functional and histological changes after oophorectomy in the rabbit clitoris and vagina to determine the mechanism responsible for the development of arousal disorder in postmenopausal women. Twenty mature female New Zealand white rabbits were randomly divided into three groups: control; oophorectomy; and estrogen replacement after oophorectomy. We compared the nitric oxide synthase (NOS) activity and the degree of expression of neuronal (nNOS) and endothelial NOS (eNOS) using biochemical and Western blot analysis in clitoral and vaginal tissues. Histological change of smooth muscle and collagen contents in those tissues were also compared using Masson's trichrome staining. NOS activity and the expression of nNOS and eNOS were significantly increased in the oophorectomized group while there was a decrease to the level of the control group in the estrogen replacement group. Histological examination showed that oophorectomy induced a significant increase in collagen and decrease in muscle content in both clitoris and vagina, while the ratio of smooth muscle content was increased significantly after the estrogen replacement. Our results clearly demonstrate that estrogen deficiency induces compensatory NOS production which may be related to decreases in muscle to collagen ratio in female rabbit genital organs.     

Technical aspects of perichondrial grafting in the rabbit

A screening process to determine the most appropriate model for the study of cartilage growth from perichondrium obtained from the rabbit's left tenth costal cartilage has resulted in the following observations: (1) best growth is achieved when fixation of the graft is secure and conformity to the recipient bed is complete; (2) immobilization enhances fixation, but permits fibrous tissue growth onto the graft, and (3) diminishing periods of immobilization enhance perichondrial growth, but have a deleterious effect on fixation.     

Histologic evaluation of human cadaveric fascia lata in a rabbit vagina model

The purpose of this study was to evaluate the histologic response of human cadaveric fascia lata after vaginal implantation. Freeze-dried, gamma-irradiated cadaveric fascia lata from three lots was implanted between the rectovaginal membrane and vaginal epithelium in New Zealand white rabbits. Rabbits were killed at 2, 4, 8, and 12 weeks after implantation. At necropsy, gross findings were described and specimens for routine cultures were taken. Histologic evaluation determined graft integrity, neovascularization, inflammatory response, and host tissue incorporation. Nine rabbits were available for histologic analysis and 14 for gross and microbiologic analysis. Vaginal erosions occurred with three grafts. The remainder were adherent to the surrounding tissues. Erosion was associated with bacterial colonization of the graft. Autolysis of one graft occurred at 4 weeks. Over time, the inflammatory response decreased and neovascularization increased; by 12 weeks, the graft collagen was replaced by host collagen. Cadaveric fascia lata serves as scaffolding for host tissue incorporation with replacement by host collagen.Oral/Poster presentation at the Annual Meeting of the Society of Gynecologic Surgeons, Orlando, Florida, March 2001.     

海水浸泡的兔髌韧带爆炸伤修复的组织学特点

目的观察海水浸泡的兔髌韧带爆炸伤修复的组织学变化。方法新西兰白兔36只,以0.9g单质猛炸药黑索今(RDX)铜壳小型爆炸装药捆绑于兔膝关节前外侧,电引爆,制作兔膝关节开放性爆炸伤并海水浸泡1h的模型。经扩创消炎,分别于第4天(n=19)和第6天(n=1)采用直接缝合法修复炸断髌韧带。分别于爆炸伤后即刻、海水浸泡1h及修复后1、2、3个月时切取爆炸震击及炸断的韧带做组织学及电镜观察。结果震击伤(n=14)显示韧带纤维扭曲、挛缩;炸断伤(n=22)显示韧带纤维断裂,成纤维细胞杂乱堆积,以Ⅰ型胶原纤维为主。海水浸泡1h后,组织水肿,以Ⅲ型胶原纤维为主。经修复后3个月,震击伤韧带已近于正常,炸断伤韧带纤维排列松散,成纤维细胞数目明显少于震击伤韧带。结论兔髌韧带爆炸伤并海水浸泡后,韧带成纤维细胞以分泌Ⅲ型胶原为主。震击伤韧带修复后3个月已恢复正常;炸断韧带缝合修复后3个月与正常韧带仍有明显差别。     

Classification and functional aspects of portal hypertension

Portal hypertension can be classified into two main groups, presinusoidal (intrahepatic and extrahepatic) and intrahepatic.Presinusoidal extrahepatic portal hypertension is unlikely to be associated with hepatocellular failure. Increased splenic flow plays a minor role in its cause. Renal cortical perfusion may be reduced.Causes of presinusoidal intrahepatic portal hypertension include schistosomiasis, myeloproliferative diseases, sarcoidosis, congenital hepatic fibrosis, chronic arsenic poisoning, and primary biliary cirrhosis. Portosystemic shunt operations are well tolerated unless there is associated hepatocellular damage.In cirrhosis, the portal hypertension is presinusoidal, sinusoidal, and postsinusoidal. The problem of bleeding esophageal varices is largely that of hepatocellular failure.The Budd-Chiari (hepatovenous obstruction) syndrome has many causes, including “congenital” webs and trauma. These may be susceptible to a surgical approach.     

Anatomical and functional aspects of the thoracic and lumbar spine

The vertebral bodies and vertebral arches show a characteristic distribution of cortical and cancellous bone. The pedicles are loaded by uniplanar bending that is reflected by the arrangement of the Corticalis. The ligaments of the vertebral column consist of longitudinal and (with exception of the lig. longitudinal anterius) horizontal/oblique segmental ligament bundles. In combination with the anulus fibrosus, the ligaments work as a kind of gear system. They regulate the process of movements of adjacent vertebral bodies in a very precise manner and control the final phase of motion. Besides maintaining the necessary amount of pretension the intervertebral disc distributes the loads uniformly onto the adjacent vertebral bodies. The intervertebral joints are important for guided motion, by restricting the extent in specific planes and directions. Because of their position, they are able to take up the shear forces and to simultaneously restrict them in different planes. The integrity of the fascia thoracolumbalis warrants the protective function of the autochthonuos muscles.     

Morphologic and functional aspects of the assessment of hand injuries

Progress achieved in surgical approach to hand injuries have called for reconsideration of earlier recommendations for expert assessment. While in the past, emphasis used to be laid on judgement of loss caused by amputation, today primary attention must be given to assessment of the individual finger which had been surgically reconstructed but has been left with impaired function. An account is given of the functional relevance that should be attributed to each of the functional elements of a hand, and reference is made to consequences from loss of functions. Some recommendations are suggested for expert assessment.     

Histological and biomechanical observations of the rabbit patellar tendon after removal of its central one-third

Using 35 Japanese white rabbits, a study was made of tissue regeneration and the mechanical properties of the patellar tendon after removal of its central one-third. After removal of the central one-third of the patellar tendon on one side, in experiment I the strength of the entire patellar tendon including the regenerated tissue was compared with that of the patellar tendon on the opposite side with the central one-third removed at the time of killing, and in experiment 2 the strength of only the regenerated tissue was compared with that of the patellar tendon on the opposite side with two-thirds of the medial and lateral sides removed at the time of death. In experiment 1, the maximum load showed no significant difference between the operated side and the control. In one-half of the cases, the strength of the operated side including the regenerated tissue was weak, suggesting weakening of the patellar tendon on the residual bilateral sides. In experiment 2, the maximum load of the regenerated tissue was significantly lower than that of the control, the former being 25% of the latter even at 6 months. Histologically, the characteristics of the cells and collagen fibers gradually approached those of normal tissue, but the crimp pattern of the collagen fibers and fibrils was evidently smaller than that of the control. These results indicate that regenerated tissue was still mechanically weak and immature at 6 months.