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.     

Positive autoradiographic findings in brains of four MS patients

Autoradiography of brain slices from 4 multiple sclerosis (MS) and 9 control patients was performed. After 6 weeks of exposure the exact picture of the white matter appeared on the X-ray films in all cases with MS, but only in one of the controls. The high level of autoradiographic signal from MS white matter suggests that an abnormal accumulation of radioactive trace elements takes place within the brains of MS victims.     

A Drosophila melanogaster hobo-white+ vector mediates low frequency gene transfer in D. virilis with full interspecific white+ complementation

Transformation of a Drosophila virilis white mutant host strain was attempted using a hobo vector containing the D. melanogaster mini-white⁺ cassette (H[w⁺, hawN]) and an unmodified or heat shock regulated hobo transposase helper. Two transformant lines were recovered with the unmodified helper (HFL1), one containing only the white⁺ marked vector, and a sibling line containing the vector as well as an HFL1 helper integration. An approximate total transformation frequency of 1% is deduced. A high frequency of wing and eye morphology mutants were also observed, suggesting that hobo may have mobilized a related element in D. virilis. The data reaffirms a relatively low transformation vector activity for the hobo transposon in D. virilis; however, nearly full interspecific expression of the white⁺ marker supports its possible function in other species as well.     

Diffusion Weighting by the Trace of the Diffusion Tensor within a Single Scan

The anisotropy of the water diffusion tensor inside brain causes contrast in diffusion images, which depends on the relative orientation of the diffusion gradients and the subject. Because the trace of a tensor is invariant upon rotation, measurement of this trace can reduce the orientation effect. A family of imaging pulse sequences is presented in which the signal intensity is weighted by the trace of the diffusion tensor in a single scan. The methods are demonstrated for chicken gizzard in several orientations with respect to the gradient frame of reference, and for ischemic injury in cat brain after middle cerebral artery occlusion. The sensitivity of the techniques to the presence of background gradients is measured and discussed in detail. As a result, pulse sequences are suggested that provide reliable diffusion constants in both homogeneous and inhomogeneous magnetic fields. The efficiency of the techniques for clinical application is also evaluated.     

白发与黑发的微量元素分析

本文应用EPM-810Q电子探针,对53例35～60岁健康成年人白发与黑发(指长在同一部位、相邻单根白发与黑发),进行微量元素分析,结果表明:白发中Mg、Al、Cd、Ca、Cr、Mn、Fe、Se微量元素含量明显小于黑发,而Cu、Zn、Pb元素含量大于黑发。以上差异有显著性意义(P<0.001),并对上述差异进行了讨论。     

A trace element preparation increases antitumor activity in mice

A trace element preparation (Béres Drops Plus, BDP) produced immunomodulatory effects in previous in vitro and in vivo experiments. Here, C57B1/6 inbred mice were transplanted with either Lewis lung tumor or with B16 melanoma. BDP was given intraperitoneally a. before transplantation; b. after transplantation or c. after the removal of the primary tumor. As a result, BDP pretreatment could slow down the tumor progression by decreasing the number and the volume of metastases as well as the proportion of mice with metastases without influencing the growth of the primary tumors. Furthermore, BDP treatment improved the immunological activity of the tumor-bearing host, too. These preliminary data suggest that the parenteral administration of the practically non-toxic BDP could help to control tumor progression in experimental models.     

Short-lasting conditioned stimulus applied to the middle cerebellar peduncle elicits delayed conditioned eye blink responses in the decerebrate ferret

In delay eye blink conditioning, the conditioned stimulus (CS) ends at the time of the unconditioned stimulus (US). If the CS duration is decreased, there will be a 'trace' period with no ongoing CS before the onset of the US. During this period some neural activity has to continue after the CS offset to: (i) permit association between the CS and the US; and (ii) elicit a conditioned response appearing after the CS offset. In this study we test the role of the cerebellum in maintaining CS activity required for eliciting a conditioned response after the CS offset. Decerebrate ferrets were trained in a delay conditioning paradigm with an electrical stimulation of the forelimb as CS and of the periorbital area as US. The conditioned responses in the upper eyelid were monitored with electromyographical techniques. In well-trained animals, test CSs of short duration down to 0.2 ms were applied to the forelimb or the middle cerebellar peduncle, while the interstimulus interval between CS onset and US onset was kept constant at 300 ms. Test CSs of short duration applied to the forelimb elicited conditioned responses. More importantly, also a short-lasting CS to the middle cerebellar peduncle could elicit conditioned responses. The results indicate that precerebellar CS pathways are not required for maintaining the neural activity that elicits conditioned responses after the CS offset. It is suggested that neurons maintaining such activity are located in the cerebellum, either the cortex alone or the cortex and the deep nuclei.     

苣荬菜无机元素的分析

目的:分析苣荬菜中的无机元素.方法:采用美国Varian Spectra A30型原子吸收分光光度计测定.结果:表明苣荬菜中含有丰富的人体必需的无机元素.结论:苣荬菜有较高的开发利用价值.     

测试居民区住宅外鼠密度的可行性研究

目的塑料地板胶制鼠迹板测试居民区住宅外鼠密度可行性。方法在居民区住宅外分3种生境进行试验,次日观察鼠迹板阳性率、损坏率和丢失率。结果普通地面平均损坏率为49．1％,楼梯、外长廊为16．3％,楼顶、露台损坏率为10．0％。经秩和检验,普通地面与另外2种生境之间的鼠迹板损坏差别有统计学意义（U=5．72和6．37,P〈0．001）,而楼梯、外长廊与楼顶、露台之间比较鼠迹板损坏差别无统计学意义（U=0．97,P〉0．05）。结论鼠迹板适合监测鼠情,测试居民区外环境鼠密度有待研究。