Neuronal regeneration after application of radiofrequency energy to collagenous tissue is affected by limb immobilization: an in vivo animal study.

Despite widespread use of radiofrequency (RF)-shrinkage, there have been no studies on the influence of RF-energy on neural elements of collagenous tissue. The purpose of this study was to examine the effect of RF-shrinkage on neural structures of capsuloligamentous tissue and the recovery of neural elements under different postoperative treatment protocols. One patellar tendon of 46 New-Zealand-White rabbits was shrunk. Six rabbits were sacrificed immediately postoperative. Twenty rabbits were not immobilized, 10 were immobilized for 3 and 10 were immobilized for 6 weeks. A monoclonal antibody, specific against a neurofilament protein, was used to detect nerves and neural structures. Staining pattern of nerve fibres was significantly altered immediately postoperative. After 3 weeks the number of nerve fibres and bundles decreased significantly in immobilized and non-immobilized limbs. The loss of nerve fibres was significantly less in immobilized limbs. At 6 weeks the number of neural elements in immobilized limbs increased to the level of untreated control tissue. In non-immobilized limbs we found no recovery of neural elements 9 weeks postoperatively. At this time the number of nerve fibres and bundles was still significantly less compared to the untreated control limbs. RF-shrinkage causes significant alteration of neural elements. Under immobilization nerve fibres and bundles reach the level of normal untreated tissue. Careful rehabilitation is important after RF-shrinkage. Not only for biomechanical reasons, but also to allow the neural elements to recover, thermally modified tissue should be protected from normal physiologic loads.     

新型脊柱固定器械的研制与临床应用

自１９８９年以来，临床应用一种新型脊柱固定器械，共６８例，其中５２例为胸腰椎骨折，１６例为椎体滑脱。经临床观察和随访，治疗效果满意。这种新型固定器械，既可行胸腰椎骨折的固定，也可行椎体滑脱的复位。根据临床需要，该器械可行压缩、撑开、成角和中立位固定。作者强调，脊柱损伤只要有手术指征，手术时机甚为重要，应早期或立即手术，有利于脊柱骨折和椎管前方骨块的复位，早期也有利于神经功能的恢复。     

Effects of melanotan II,a melanocortin agonist,on grooming and exploration in rats after repeated restraint/immobilization

2 mg/kg melanotan II (MTII, administered i.p.), a cyclic peptide analog of α-melanocyte stimulating hormone, at a single dose increased grooming in naive rats placed in an unfamiliar open-field device without changing locomotion or rearing. Male rats exposed to restraint/immobilization stress (IS) for 1 h on three consecutive days displayed increased grooming after the second stressor exposure, compared to pre-stress levels. MTII, administered to the rats after IS, enhanced the grooming response compared both to the pre- and post-stress values. The increase was greatest after the first dose and declined over the following two applications. As to the locomotion of rats in the entire experimental space, IS reduced the distance moved only after the first two stressor exposures; MTII did not influence these alterations. Locomotion in the central part of arena was not reduced by the stressor or by MTII, on the contrary, there was an increase in both groups after the third intervention. The only observed change in rearing was an increase in the MTII group after the third restraint exposure. Thus, MTII selectively increased grooming without markedly affecting the spatio-temporal structure of locomotor behavior in the open-field. The decline of MTII enhanced grooming over the three test days may be interpreted in terms of adaptation to the stressor and of the developing tolerance to the peptide.     

Activated polyurethane modified with latent thiol groups

A novel type of modified polyurethane with pendant acetylthio groups (as a latent form of thiol groups) has been proposed for the use in surface modifications with various biomolecules. The polymer was prepared via a modified variant of low-temperature bromoalkylation of urethane hard segments followed by the reaction of pendant bromoalkyl groups with thiolacetic acid in mild conditions. The extent of modification with acetylthio groups can be made as high as 0.45 mmol/g. After deprotection of acetylthio groups and reaction of the resulting thiol groups with an excess of Ellman's reagent, 0.1 nmol/cm(2) of thiol-reactive 3-carboxy-4-nitrophenyldithio groups were detected on the surface of films cast from the modified polymer. A sensitive fluorescent probe--dansyl-L-cysteine was used for the quantification of thiol-reactive groups bound to the surface. The acetylthio-modified polyurethane is sufficiently stable to withstand conditions typical for the high-temperature processing (molding, extrusion) of polyurethanes.     

小儿废用性骨质疏松与骨折

为提高对废用性骨质疏松与骨折的警惕性,探讨其防治措施,对13 例儿童因 髋关节疾病经手术、石膏固定术后1~9个月,发生废用性骨质疏松和骨折进行了回顾性分析 。结果：13例患儿15个部位发生了废用性骨折,经非手术疗法,配合药物治疗,获骨性愈合 。早期确定废用性骨质疏松的诊断,缩短不必要的肢体固定时间,尽早功能锻练,加强保护 ,避免外伤,配合内科药物疗法对防治本病有重要作用。     

Optimal immobilization of penicillinase for lon-selective electrode

Penicillin sensor was prepared by immobilizing penicillinase (Pcase) on H⁺-selective carboxylated poly (vinyl chloride) (PVC-COOH) membrane or cellulose filter membrane. The immobilization techniques are as follows. Pcase was immobilized with GTH on H⁺-selective PVC-COOH membrane or some amount of BSA was dropped on that membrane. Another method to make immobilization is to mix type I Pcase with GTH and drop on a cellulose filter membrane. According to immobilization techniques, there were some differences in response properties of enzyme electrodes, however, all electrodes responded to Pcase-resistant penicillin derivatives. Pcase immobilized on cellulose filter membrane with H⁺-selective PVC membrane eletrode was more stable and more sensitive to penicillinase-resistant penicillin derivatives than any other immobilization techniques.     

恒力法测量制动对兔髌韧带截面面积的影响

目的：介绍一种测量软组织截面面积的装置和方法。方法：用测微仪对膝关节制动前后兔髌韧带截面面积进行反复测量。结果：测微仪的变异系数在０．９％以下,制动６周后髌韧带的截面面积明显增大。结论：兔髌韧带截面面积的这种变化与组织的胶原代谢水平相关     

Rigid immobilization alters matrix organization in the injured rat medial collateral ligament.

The effects of mobilization on matrix reorganization and density after ligament injury were studied in rat medial collateral ligaments using scanning electron microscopy (SEM). Both medial collateral ligaments of 14 Sprague-Dawley rats were sharply incised transversely at their midpoint. A 1.14-mm threaded Kirschner wire was driven through the tibia and into the femur of the right leg (through the knee) to immobilize that knee at 90 degrees of flexion. Four additional rats were used as controls. The right medial collateral ligament of the control rats was exposed in the same manner as the experimental rats and the wound closed without damaging the ligament. Rats were sacrificed on the 7th and 14th days postinjury and the ligaments evaluated by SEM. The electron micrographs from this study demonstrated that early on, the tissue at the injury site is disorganized on a gross scale with large bundles of poorly organized matrix. Large "defects" were present between bundles in the substance of the ligament and appeared as holes in the ligament around the injury site. As healing progressed, the matrix in the mobilized specimens appeared to bridge the injury site more rapidly and completely with fewer "defects" and thus higher density than the immobilized specimens.