Methods for the Study of the Zebrafish Maxillary Barbel

Barbels are skin sensory appendages found in fishes, reptiles and amphibians. The zebrafish, Danio rerio, develops two pairs of barbels- a short nasal pair and a longer maxillary pair. Barbel tissue contains cells of ectodermal, mesodermal and neural crest origin, including skin cells, glands, taste buds, melanocytes, circulatory vessels and sensory nerves. Unlike most adult tissue, the maxillary barbel is optically clear, allowing us to visualize the development and maintenance of these tissue types throughout the life cycle. This video shows early development of the maxillary barbel (beginning approximately one month post-fertilization) and demonstrates a surgical protocol to induce regeneration in the adult appendage (>3 months post-fertilization). Briefly, the left maxillary barbel of an anesthetized fish is elevated with sterile forceps just distal to the caudal edge of the maxilla. A fine, sterile spring scissors is positioned against the forceps to cut the barbel shaft at this level, establishing an anatomical landmark for the amputation plane. Regenerative growth can be measured with respect to this plane, and in comparison to the contralateral barbel. Barbel tissue regenerates rapidly, reaching maximal regrowth within 2 weeks of injury.Techniques for analyzing the regenerated barbel include dissecting and embedding matched pairs of barbels (regenerate and control) in the wells of a standard DNA electrophoresis gel. Embedded specimens are conveniently photographed under a stereomicroscope for gross morphology and morphometry, and can be stored for weeks prior to downstream applications such as paraffin histology, cryosectioning, and/or whole mount immunohistochemistry. These methods establish the maxillary barbel as a novel in vivo tissue system for studying the regenerative capacity of multiple cell types within the genetic context of zebrafish.     

Improvement of protoplast culture protocols for Beta vulgaris L. (sugar beet)

Summary The effects of NaCl, feeder cells and the embedding of protoplasts in calcium alginate have been investigated in an attempt to improve culture conditions of recalcitrant sugar beet (Beta vulgaris L.) mesophyll protoplasts. While the use of NaCl in all instances proved detrimental to protoplast development, the other two treatments had clear beneficial effects. Minimum plating densities, necessary to sustain cell division, could be reduced to <5% (<4000 protoplasts / ml) of the control levels and plating efficiencies could be significantly enhanced by approx. 10 fold. Plants could still be regenerated from soft calli derived from mesophyll protoplasts cultured under the modified conditions at a frequency of 20–30 %. In particular, the use of alginate is considered of potentially great importance for the further application of beet protoplasts for other aims e.g. asymmetric hybridization.     

Orientation of Small Specimens for Cryosectioning

A simple technique is introduced to achieve symmetrically oriented frozen sections of small specimens such as young fish or frog larvae. Small samples are especially difficult to orient if they are already frozen to the chuck in a freezing microtome. Orientation of the sample in a mold filled with embedding medium prior to freezing permits sectioning as well as easy labeling and storage of the specimens. The use of a stereo microscope during orientation is optional.     

植物石蜡切片包埋、修蜡过程的改进

传统的石蜡切片包埋、修蜡操作过程耗时费力。采用金属框替代纸质包埋盒进行组织包埋,将蜡块冷水冷却改为自然冷却,趁蜡块未完全变硬之前进行快速修整。该方法不仅提高了实验效率,而且修出的蜡块工整一致,同时对后面的切片过程无任何影响。     

A Quick Embedding Method for Light and Electron Microscopy of Textile Fibers

A quick embedding method employing UV polymerization reactions has been devised for embedding fibers in acrylic and meth-acrylate media. The resultant thin, flat embed-dings are suitable for both light and electron microscopy.     

Histochemical and immunohistochemical protocols for routine biopsies embedded in Lowicryl resin

We describe a novel method that allows reliable detection of in situ hybridization signals in thin sections of plastic embedded embryos. Sections from plastic embedded embryos are thinner and have superior histological quality compared to paraffin, gelatin, agarose embedded sections or cryosections; however, plastic resin traditionally has not been used as an embedding medium following in situ hybridization because of loss of signal. When signal is detected with alkaline phosphatase and NBT/BCIP, the resulting colored precipitate is subject to fading when samples are exposed to organic compounds. The colored precipitate can be redeposited by repeating the NBT/BCIP reaction following plastic sectioning. This recolorization shows no loss of specificity, because signal is detected only where the anti-digoxigenin/alkaline phosphatase conjugated antibody is bound to the riboprobe. Strong signals can be detected without recolorization; however, weaker signals require the recolorization step. This novel method of re-depositing colored precipitate after processing and sectioning allows accurate determination of the location of gene expression and study of this expression in high quality histological sections of early chick embryos.     

Resin Embedding for Quantitative Immunoelectron Microscopy. A Comparative Computerized Image Analysis

Quantitative immunoelectron microscopy (QIEM) is dependent on the reliability of preparative techniques for both efficient immunolabeling and consistent quantitative results among series of immunostained sections. The present study compared Lowicryl K4M and Epon embedding after identical fixation and dehydration of rat somatotrophic secretory granules. Labeling intensity, diameter, roundness, uptake of uranyl acetate, and gray value were measured with computer assisted image analysis. Lowicryl-embedded granules showed the highest labeling densities after conventional fixation and Progressively Lowering Temperature (PLT) dehydration, but values were not consistent in a series of immunostained sections. A lower but more uniform level of immunostaining was seen in Eponembedded sections when tissue was cryofixed and physically dehydrated. Gray value measurements from micrographs from both embedding media confirmed the better contrast of Epon sections and the different reliefs of the granule surfaces. This study emphasizes the importance of complete comparisons of preparative techniques for QIEM for reliability and reproducibility.     

双切口双侧钢板治疗SchazkerV, VI型骨折的疗效分析

目的：探讨双切口双侧钢板法与传统手术治疗SchazkerV、VI 型骨折的临床疗效及安全性。方法：回顾性分析2007 年6 月 -2012 年6 月在我院行手术治疗的50 例SchazkerV、VI型骨折患者的病历资料,根据手术方法不同将患者分为治疗组及对照组。 治疗组25 例采用双切口双侧钢板治疗,对照组25 例采用锁定钢板内固定治疗。观察并比较两组的临床疗效及膝关节功能评分 变化。结果：治疗组住院时间、TPA、PSA、并发症发生率均低于对照组,差异有统计学意义(t=-2.889、-2.220、-2.377、4.348,P<0.05); 治疗后两组Rasmussen 分级优良率均高于治疗前(P<0.05),治疗组优良率高于对照组(P<0.05)。结论：采用双切口双钢板内固定术 治疗SchatzkerV、VI型胫骨平台骨折患者的临床疗效明显优于传统手术方法,可以显著降低术后并发症的发生率及住院时间。     

浮针埋线联合推拿疗法对神经根型颈椎病疗效及对颈椎活动度、生理曲度变化的影响

摘要 目的：探讨与分析浮针埋线联合推拿疗法对神经根型颈椎病疗效及对颈椎活动度、生理曲度变化的影响。方法：2019年2月到2021年6月选择在本院诊治的神经根型颈椎病患者105例作为研究对象,根据1：1简单分配原则把患者分为浮针组53例与对照组52例。对照组给予推拿治疗,浮针组在对照组治疗的基础上给予浮针埋线治疗,两组都治疗观察21 d,记录患者颈椎活动度、生理曲度变化情况。结果：治疗后浮针组的总有效率为98.1 %,与对照组的86.5 %相比有明显提高（P<0.05）。浮针组与对照组治疗后的颈椎活动度评分明显低于治疗前,浮针组与对照组相比也明显降低（P<0.05）。浮针组与对照组治疗后的疼痛视觉模拟评分法（VAS）评分明显低于治疗前,颈椎日本骨科协会评估治疗分数（JOA）评分明显高于治疗前,治疗后浮针组与对照组对比也有明显差异（P<0.05）。浮针组与对照组治疗后的颈椎生理曲度明显高于治疗前,浮针组也明显高于对照组（P<0.05）。结论：浮针埋线联合推拿疗法在神经根型颈椎病患者的应用能促进缓解疼痛,改善颈椎功能,能提高治疗疗效,改善患者的颈椎活动度,还可促进颈椎生理曲度恢复正常。     

多酶共固定化的研究进展

固定化酶技术是现代生物催化的核心技术。过去几十年里,固定化酶技术的研究主要集中在单酶固定化。近年来,多酶共固定化由于具有可增加反应的局部浓度、提高反应收率等优点而得到研究者的广泛关注。本文根据国内外研究现状并结合本实验研究从多酶非特异性共价共固定化、非特异性非共价共固定化、非共价包埋固定化以及位点特异性固定化四个方面阐述多酶固定化方法的研究进展,并分析和展望了其在工业上的应用前景。