腹腔镜手术治疗粘连性肠梗阻的疗效及安全性研究

目的：探讨腹腔镜粘连松解术治疗粘连性肠梗阻（AIO）的疗效，减少再梗阻率。方法：将120 例AIO 患者随机分为两组，每 组60 例，开腹组实施开腹手术，腹腔镜组实施腹腔镜粘连松解术，观察两组术后恢复及并发症发生情况，对再梗阻危险因素进行 Logistic 回归分析。结果：腹腔镜组术中失血量（73.48± 9.32）mL，少于开腹组的（207.45± 33.21）mL（P<0.05）；腹腔镜组手术、术后 镇痛、下床活动、肠恢复蠕动、肛门恢复排气、拔除尿管及住院时间分别为（69.15± 10.13）min、（14.67± 7.23）h、（27.14± 7.04）h、 （3.11± 0.96）d、（3.24± 1.02）d、（3.37± 1.23）d、（7.95± 3.05）d，均短于开腹组的（83.84± 9.24）min、（27.38± 8.02）h、（36.23± 5.87） h、（4.05± 1.35）d、（4.35± 1.74）d、（5.02± 2.13）d、（10.35± 3.71）d（P<0.05)；腹腔镜组并发症发生率、再梗阻率分别为10.00%、 10.00%，均低于开腹组的33.33%、40.00%（P<0.05)；多因素Logistic 回归分析显示开腹手术、手术时间≥ 60 min 是再梗阻发生的独 立危险因素。结论：腹腔镜手术治疗AIO 疗效优于开腹手术，而且并发症与再梗阻率低。     

Pituitary Secretory Granule Topography: Influence of Different Electron Microscopic Preparation Procedures on the Surface of Epon Sections

Human, rat and mouse pituitary tissues have been examined electron microscopically in transmission (TEM), scanning-transmission (STEM) and scanning (SEM) modes for the surface appearance of the secretory granules in tissue sections. Cryofixed and cryosectioned tissue showed only slightly protruding granule profiles which had a smooth surface. Cryofixed, freeze-dried and Epon embedded pituitaries, on the other hand, demonstrated swollen and furrowed surfaces over the granules after contact with water. This topography could also be seen after glutaraldehyde fixation but less after post-fixation in OsO₄. The surface alterations in the sections of pituitary secretory granules are thought to be due to differences in the homogeneity of the resin infiltration, leaving resin-free openings where water can enter. It also seems probable that the Epon resin is more influenced by water than has been previously assumed, based on the findings of efficient elimination of osmium from the granules after incubation of tissue sections in water for only 10 min.     

Purification of Neuronal Cell Surface Proteins and Generation of Epitope-Specific Monoclonal Antibodies Against Cell Adhesion Molecules

To establish a procedure for the purification of a broad spectrum of cell surface proteins, three separate methods based on different principles were compared with the aid of four marker proteins. Membrane preparation by sedimentation-flotation centrifugation, temperature-induced phase separation with Triton X-114, and lectin affinity chromatography were used separately as well as in combination. The two-step procedure of membrane preparation and lectin affinity chromatography provided by far the best enrichment of cell surface marker proteins. This result was further substantiated by screening greater than 6,600 hybridoma cultures that originated from mice that had been immunized with protein fractions obtained by different purification protocols. In addition, it was found that solubilized glycoproteins used as immunogens led to many more cell surface-specific monoclonal antibodies than glycoproteins immobilized on lectin-agarose beads. Three monoclonal antibodies that recognize distinct epitopes of cell adhesion molecules (CAMs) were isolated. Monoclonal antibody C4 bound to a detergent-labile epitope of G4 (neuron-glia CAM). Monoclonal antibody D1 recognized specifically nonreduced neural CAM (N-CAM) with intact disulfide bridges, and monoclonal antibody D3 recognized only the 180-kilodalton isoform of N-CAM. Because of these specificities, these monoclonal antibodies promise to be useful tools for the elucidation of the structural organization of adhesion molecules.     

CELL SURFACE ALTERATIONS BY TAXOL ASSOCIATED WITH ABNORMAL MORPHOGENESIS IN THE CHICK EMBRYO

The anticancer drug taxol brings about its biological effects by altering the stability of microtubules. We have examined the effects of taxol on early morphogenesis in chick embryos culturedin vitro. Taxol induced various abnormalities in the developing nervous system, heart and somites as well as general retardation of development. SEM studies revealed that taxol treatment leads to dramatic alterations in the embryonic cell surfaces. Time-course experiments demonstrated that the action of taxol is very rapid and becomes evident within a few minutes at the ultrastructural level. Taxol thus throws embryonic cell adhesion and motility out of balance. This appears to be the major cause of abnormal morphogenesis in taxol-treated embryos.     

Zosteric acid and salicylic acid bound to a low density polyethylene surface successfully control bacterial biofilm formation

The active moieties of the anti-biofilm natural compounds zosteric (ZA) and salicylic (SA) acids have been covalently immobilized on a low density polyethylene (LDPE) surface. The grafting procedure provided new non-toxic eco-friendly materials (LDPE-CA and LDPE-SA) with anti-biofilm properties superior to the conventional biocide-based approaches and with features suitable for applications in challenging fields where the use of antimicrobial agents is limited. Microbiological investigation proved that LDPE-CA and LDPE-SA: (1) reduced Escherichia coli biofilm biomass by up to 61% with a mechanism that did not affect bacterial viability; (2) significantly affected biofilm morphology, decreasing biofilm thickness, roughness, substratum coverage, cell and matrix polysaccharide bio-volumes by >80% and increasing the surface to bio-volume ratio; (3) made the biofilm more susceptible to ampicillin and ethanol. Since no molecules were leached from the surface, they remained constantly effective and below the lethal level; therefore, the risk of inducing resistance was minimized.     

Meloidogyne incognita Surface Antigen Epitopes in Infected Arabidopsis Roots

Surface-coat epitopes of Meloidogyne incognita were detected in root tissues of Arabidopsis thaliana during migration and feeding site formation. A whole-mount root technique was used for immunolocalization of surface coat epitopes in A. thaliana, with the aid of a monoclonal antibody raised specifically against the outer surface of infective juveniles of M. incognita. The antibody, which was Meloidogyne-specific, recognized a fucosyl-bearing glycoprotein in the surface coat. During migration in host tissues the surface coat was shed, initially accumulating in the intercellular spaces next to the juvenile and later at cell junctions farther from the nematode. Upon induction of giant cell formation, the antibody bound to proximally located companion cells and sieve elements of the phloem.     

Tuning cellular responses to BMP-2 with material surfaces

Bone morphogenetic protein 2 (BMP-2) has been known for decades as a strong osteoinductive factor and for clinical applications is combined solely with collagen as carrier material. The growing concerns regarding side effects and the importance of BMP-2 in several developmental and physiological processes have raised the need to improve the design of materials by controlling BMP-2 presentation. Inspired by the natural cell environment, new material surfaces have been engineered and tailored to provide both physical and chemical cues that regulate BMP-2 activity. Here we describe surfaces designed to present BMP-2 to cells in a spatially and temporally controlled manner. This is achieved by trapping BMP-2 using physicochemical interactions, either covalently grafted or combined with other extracellular matrix components. In the near future, we anticipate that material science and biology will integrate and further develop tools for in vitro studies and potentially bring some of them toward in vivo applications.