Dynamic Change of CD34 Level during the Survival Process of Narrow Pedicle Flap

Objective

To evaluate the dynamic change of CD34 level during the survival process of narrow pedicle flaps.

Methods

Twenty-five white pigs were randomly and equally divided into 5 experimental groups. Five different type of narrow pedicle with different length-to-width ratio were employed, and each type of narrow pedicle was covered with 5 different size random flaps and which was classified into A, B, C, D and E for 5 groups. Group A was control group. Each type narrow pedicle with 5 different skin flaps were implanted onto the back of the pigs along the midline of back with a reverse direction. A 0.3 cm×0.3 cm full thickness skin flap in the middle of distal segment was collected and on 3rd, 5th, 7th and 14th days of post-operation. The expression of CD34 was measured by immunohistochemistry and enzyme-linked immunosorbent (ELISA).

Results

Histological examination showed that with the increasing of length-to-width ratio of the narrow pedicle skin flaps, the expression of CD34 increased in the skin flaps. Increased level of CD34 was found on 3rd day post-operation, and the peak expression was found on 7th day. Persistent high level of CD34 was found until 14th day.

Conclusion

Increased CD34 level in the distal skin flap, there is the association between CD34 level and ischemia injury. Moreover, CD34 expression plays an important role during the repair processes of pedicle flaps.     

胫后动脉穿支皮瓣与吻合皮下静脉的带蒂皮瓣对四肢皮肤及软组织缺损的应用效果对比

摘要 目的：对比胫后动脉穿支皮瓣与吻合皮下静脉的带蒂皮瓣对四肢皮肤及软组织缺损的应用效果。方法：选取2017年3月到2022年3月68例四肢皮肤及软组织缺损患者,各组均为34例。所有患者均采取皮瓣修复手术,对照组患者采取胫后动脉穿支皮瓣治疗,观察组采取吻合皮下静脉的带蒂皮瓣治疗。对比临床疗效,术中出血量、等指标,最后对两组患者进行1年随访,对比其并发症发生率及1年内术后二次修复情况。结果：观察组治疗总有效率较对照组高（P＜0.05）;两组患者术中出血量、手术时间、术后VAS评分对比无明显差异,观察组住院时间、创面愈合时间明显低于对照组（P＜0.05）;两组患者术后感觉功能恢复S3级、S2级、S1级、S0级人数对比无明显差异（P＞0.05）,观察组术后感觉功能恢复S4级人数明显高于对照组（P＜0.05）;与对照组相比,观察组出现的并发症发生率、术后二次修复率低（P＜0.05）。结论：吻合皮下静脉的带蒂皮瓣修复与胫后动脉穿支皮瓣修复术相比可进一步改善疗效,缩短住院时间,有利于创面愈合、感觉功能恢复,降低远期并发症发生率及术后二次修复率,值得临床应用推广。     

裁剪带蒂回肠移植中血管蒂延长的实验研究

目的:建立结扎不同回肠血管分支的动物实验模型,即时及术后动态观察移植肠段存活和通畅情况,从动物实验的角度探讨回肠血供特征及血管蒂延长方法,为临床外科手术改善提供实验依据。方法:家兔12只,体重量2～2.5kg。麻醉、固定、备皮、切口选取等均相同,将家兔分别分为6组,根据回肠血管分支结扎处理不同,分为A、B、C、D、E、F组,每组2只。建立饲养观察表格,并于术后即刻及7天分别取末端回肠组织行HE染色,读取病理切片结果。结果:A、D实验组结果分别与C、F对照组结果不同,B、E实验组结果分别与C、F对照组结果无明显差别。结论:带一支血管蒂的移植肠段结扎远端一支二级血管肠段可存活;带二支血管蒂的移植肠段结扎远端一支一级血管肠段可存活。同时,结扎带一支血管蒂的移植肠段的一级血管不可保障肠段存活。     

The Temperature-gradient Tunnel: a Versatile Controlled Environment

A novel controlled-environment is described which permits simultaneousstudy in a single chamber of plant growth responses to a selectedrange of constant temperatures, under controlled conditionsof light intensity and relative humidity.     

Flap Removal or Flap Preservation During LASEK Surgery

The objective of this study was to evaluate the effectiveness of corneal epithelial flap removal or flap preservation during LASEK operation on myopia and to determine whether there was any accrual of benefit in either approach. From March 2006 to March 2008, some 582 patients (1,164 eyes) who presented with myopia and myopic astigmatism were treated with corrective LASEK operations. They were divided into two groups: one group underwent corneal flap-preservation while the other had the corneal flap removed. Each group comprised 582 eyes, and the data accumulated were retrospectively analyzed. Each patient was examined after 1, 3, 5, and 7 days; 2 weeks; and 1, 2, 3, 6, and 12 months after LASEK surgery to determine their post-operative visual acuity and check for complications. All eyes achieved pre-operative corrected vision 16 weeks after LASEK surgery, with no difference being observed between the two groups. However, there was a significant difference in the ophthalmalgia observed 3 days after LASEK surgery, with the flap-removal group experiencing less post-operative pain than those who had the corneal flap preserved. Furthermore, by 3 days post-operation, the observed corneal epithelial healing was significantly different: again the eyes of those who had the corneal flap removed having a faster recovery than those belonging to the corneal preservation group. In conclusion, the patients who had a flap-removal LASEK operation recorded faster recovery and suffered less ophthalmalgia, but there was no significant difference in the overall outcome in terms of post-operative optimally corrected vision or complications such as haze formation.     

The Ultramicrotome Superstage: A Versatile Aid for Section Manipulation

The design and properties of a rigid, box-like device to be placed on the knife stage of a Porter-Blum MT-2 ultramicrotome are described. This “superstage” acts as a hand and tool rest, and a wind screen for the knife boat. The superstage easily permits tight rafts of ultrathin sections to be centrally located on grids. Additionally, it aids in placing 1 μm thick sections at the same relative location on glass slides to facilitate their examination in the light microscope.     

Versatile synthesis of oligodeoxyribonucleotide-oligospermine conjugates

A protocol for the rapid, automated synthesis of oligospermine-oligonucleotide sequences is described. To this end, a protected spermine phosphoramidite derivative was synthesized in six steps from spermine and used as the fifth synthon in an oligonucleotide synthesizer. Parameters were optimized to reach greater than 95% coupling yields. Cationic oligonucleotides show enhanced hybridization and strand invasion properties, and hence are an alternative to conventional oligonucleotides for molecular biology, diagnostic and potential therapeutic applications. A multi-gram-scale synthesis of the spermine phosphoramidite allowing several hundred coupling steps takes 2-3 weeks. Oligonucleotide synthesis and purification takes approximately 3 d.     

Flap Endonuclease 1 Mechanism Analysis Indicates Flap Base Binding Prior to Threading

FEN1 cleaves 5′ flaps at their base to create a nicked product for ligation. FEN1 has been reported to enter the flap from the 5′-end and track to the base. Current binding analyses support a very different mechanism of interaction with the flap substrate. Measurements of FEN1 binding to a flap substrate show that the nuclease binds with similar high affinity to the base of a long flap even when the 5′-end is blocked with biotin/streptavidin. However, FEN1 bound to a blocked flap is more sensitive to sequestration by a competing substrate. These results are consistent with a substrate interaction mechanism in which FEN1 first binds the flap base and then threads the flap through an opening in the protein from the 5′-end to the base for cleavage. Significantly, when the unblocked flap length is reduced from five to two nucleotides, FEN1 can be sequestered from the substrate to a similar extent as a blocked, long flap substrate. Apparently, interactions related to threading occur only when the flap is greater than two to four nucleotides long, implying that short flaps are cleaved without a threading requirement.     

脊柱椎弓根螺钉生物力学研究进展

椎弓根螺钉内固定术是目前临床上治疗脊柱骨折的常用手术方式。生物力学特别是脊柱生物力学方面的研究是其内固定器设计和研制的基础,也是评价其固定的稳定性及实用价值性的具体标准。因此,运用生物力学的理论知识来全面分析脊柱的力学改变及内固定器的作用机制,对于合理使用内固定器械以取得最满意矫形和固定效果具有重要意义。但现有实验条件及实验方法依然存在缺陷。例如,所有现有的实验均为体外实验,仅能反映即可实验结果,而且不能反映椎弓根螺钉在体内的长期力学特性。因此,本文通过椎弓根螺钉的自身设计、螺钉的植入技术、椎弓根螺钉的强化以及其他辅助椎弓根螺钉稳定性的辅助系统来全面分析脊柱椎弓根螺钉的生物力学。     

A Simple and Versatile Nebulizer

The nebulizer presented in this paper is of simple and rugged construction, permits easy control of cell concentrations, prevents sedimentation of the microorganisms, and permits the cleaning of the suspension needles even during the runs and under aseptic conditions. Fluid consumptions from 10 to 25 ml per hr were obtained with rates of primary air varying from 10 to 25 liters per min. The average diameter of the droplets varied from 1.5 to 2.7 μ.     

Versatile nitrilases: Nitrile-hydrolysing enzymes

Abstract Nitrilase, which catalyses the hydrolysis of nitriles to the corresponding acids and ammonia, was originally discovered as a plant hormone indoleacetic acid-synthesising enzyme. It is expected to be useful as a catalyst in organic chemical processing, and to have versatile functions in academic and applied fields.     

RANTES生物功能的多样性

调节活化正常Ｔ细胞表达与分泌的趋化因子(ｒｅｇｕｌａｔｅｄｕｐｏｎａｃｔｉｖａｔｉｏｎｎｏｒｍａｌＴｃｅｌｌｅｘｐｒｅｓｓｅｄａｎｄｓｅｃｒｅｔｅｄ ,ＲＡＮＴＥＳ)为ＣＣ类趋化蛋白 ,具有多种不同的生物学功能。它不仅对多种细胞有趋化作用 ,还可以强烈的激活淋巴细胞 ,参与炎症反应的发生 ,调节细胞的生长和分化 ,参与ＨＩＶ的感染。1.ＲＡＮＴＥＳ及其受体ＲＡＮＴＥＳ仅含 6 8个氨基酸残基 ,其来源广泛 ,ＮＫ细胞[1] 以及γδ Ｔ细胞[2 ] 均可组成性地表达ＲＡＮＴＥＳ ;炎症反应中ＣＤ8 Ｔ细胞、上皮细胞、成纤维细胞和血小…     

经伤椎椎弓根置钉椎体内植骨对胸腰椎骨折的疗效评价

目的:对比探讨经伤椎椎弓根置钉椎体内植骨与常规跨伤椎后路复位内固定对胸腰椎骨折的治疗方法及效果.方法:选取我院近期确诊收治的66名胸腰椎骨折患者分为两组,其中实验组36名经伤椎椎弓根置钉椎体内植骨,对照组30名行常规跨伤椎后路复位内固定,随访期间对比两组患者的临床疗效(优良率),手术时间、术中血量、伤椎前高压缩比、Cobb角、椎管侵占率等 临床指标,及Frankel分级变化.结果:治疗后,所有患者的Frankel分级及生活质量均优于治疗前(P＜0.05),而两组间相比,实验组的临床疗效及指标均优于对照组(P＜0.05).结论:经伤椎椎弓根置钉椎体内植骨治疗胸腰椎骨折,符合生物力学特征,可有效改善患者的临床症状及体征,且安全性高,值得推广.     

Versatile cell surface structures of archaea

Archaea are ubiquitously present in nature and colonize environments with broadly varying growth conditions. Several surface appendages support their colonization of new habitats. A hallmark of archaea seems to be the high abundance of type IV pili (T4P). However, some unique non T4 filaments are present in a number of archaeal species. Archaeal surface structures can mediate different processes such as cellular surface adhesion, DNA exchange, motility and biofilm formation and represent an initial attachment site for infecting viruses. In addition to the functionally characterized archaeal T4P, archaeal genomes encode a large number of T4P components that might form yet undiscovered surface structures with novel functions. In this review, we summarize recent advancement in structural and functional characterizations of known archaeal surface structures and highlight the diverse processes in which they play a role.     

Versatile mercury-resistant cloning and expression vectors

Cloning vectors have been constructed employing two diverse replicons, IncQ and P15A. Both vectors confer resistance to kanamycin (Km) and mercuric ions (Hg2+). One of these vectors, pDG105, is a broad-host-range, nonconjugative, oligocopy IncQ plasmid, which is capable of transforming Escherichia coli, Acinetobacter calcoaceticus, and Pseudomonas putida. The second vector, pDG106, is a narrow-host-range, multicopy cloning vector compatible with pBR322. Both vectors contain unique cloning sites in the Km-resistance gene for HindIII, SmaI, and XhoI, as well as unique EcoRI and ScaI sites in the mer operon. Cloning into the EcoRI site in the mer operon results in the mercury "supersensitive" phenotype, easily detectable by replica plating. Insertion of the galK gene into the EcoRI site in the mer operon results in Hg2+-inducible galactokinase activity, demonstrating the application of these plasmids as regulated expression vectors.