全喉切除术后食管语康复实践

目的总结喉全切除术食管发声训练和效果。方法对我院自1998年6月～2003年6月的59例喉癌、下咽癌全喉切除术后患者,进行食管发声康复训练。结果53例(89.8%)获得不同程度的发声功能,46例无喉者的言语水平接近正常喉言语水平,他们的最大发音时程较长、听距较远,言语可懂度高,较流利;7例发音效果差,但言语可懂度仍高;不能发声者仅6例。结论与其它发声重建相比,食管发声能很快学会发基本音,并具有发声成功率高、发声质量良好等优点。     

Systemic autoimmune disease induced by dendritic cells that have captured necrotic but not apoptotic cells in susceptible mouse strains

Systemic lupus erythematosus (SLE) is an autoimmune disorder of a largely unknown etiology. Anti-double-stranded (ds) DNA antibodies are a classic hallmark of the disease, although the mechanism underlying their induction remains unclear. We demonstrate here that, in both lupus-prone and normal mouse strains, strong anti-dsDNA antibody responses can be induced by dendritic cells (DC) that have ingested syngeneic necrotic (DC/nec), but not apoptotic (DC/apo), cells. Clinical manifestations of lupus were evident, however, only in susceptible mouse strains, which correlate with the ability of DC/nec to release IFN-gamma and to induce the pathogenic IgG2a anti-dsDNA antibodies. Injection of DC/nec not only accelerated disease progression in the MRL/MpJ-lpr/lpr lupus-prone mice but also induced a lupus-like disease in the MRL/MpJ-+/+ wild-type control strain. Immune complex deposition was readily detectable in the kidneys, and the mice developed proteinuria. Strikingly, female MRL/MpJ-+/+ mice that had received DC/nec, but not DC/apo, developed a 'butterfly' facial lesion resembling a cardinal feature of human SLE. Our study therefore demonstrates that DC/nec inducing a Th1 type of responses, which are otherwise tightly regulated in a normal immune system, may play a pivotal role in SLE pathogenesis.     

Acrylic‐Based Polyurethane/Silica Hybrids Prepared by Acid‐Catalyzed Sol–Gel Process: Structure and Mechanical Properties

Summary: Silica sols were first prepared based on different ratios of tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) by an acid‐catalyzed sol–gel process, and then incorporated into acrylic‐based polyurethanes. The structures and morphologies of silicone‐oxo clusters were studied by ²⁹Si NMR, SAXS, and scanning electron microscopy (SEM), whereas the mechanical properties of polyurethane/silica hybrids were characterized by DMA and tensile tests. The silicone‐oxo clusters in both silica sol and polyurethane hybrids became denser and larger at a higher molar ratio of TEOS/MTES and higher silica content, and the silica‐oxo clusters of polyurethane/silica hybrids even became more compact and larger than those of silica sols, increasing the elastic modulus and tensile strength of polyurethane/silica hybrids.

Typical structure of silica sol prepared from the hydrolysis and condensation of TEOS and MTES with acid as the catalyst.     

Protective levels of diphtheria-neutralizing antibody induced in healthy volunteers by unilateral priming-boosting intranasal immunization associated with restricted ipsilateral mucosal secretory immunoglobulin a

Subunit intranasal vaccines offer the prospect of inducing combined systemic-mucosal immunity against mucosally transmitted infections such as human immunodeficiency virus. However, although human studies have demonstrated the induction of active immunity, secretory immunoglobulin A (sIgA) responses are variable, and no study has demonstrated protection by accepted vaccine-licensing criteria as measured by direct toxin-neutralizing activity. Using the genetically inactivated mutant diphtheria toxoid CRM(197) in a bioadhesive polycationic polysaccharide chitosan delivery system, we found that a single nasal immunization was well tolerated and boosted antitoxin neutralizing activity in healthy volunteers, which could be further boosted by a second immunization. The neutralizing activity far exceeded accepted protective levels and was equivalent to that induced by standard intramuscular vaccine and significantly greater than intranasal immunization with CRM(197) in the absence of chitosan. A striking but unexpected observation was that although unilateral intranasal immunization induced circulating antitoxin antibody-secreting cells, a nasal antitoxin sIgA response was seen only after the second immunization and only in the vaccinated nostril. If these data are reproduced in larger studies, an intranasal diphtheria vaccine based on CRM(197)-chitosan could be rapidly licensed for human use. However, a restricted sIgA response suggests that care must be taken in the priming-boosting strategy and clinical sampling techniques when evaluating such vaccines for the induction of local mucosal immunity.     

小径微孔聚氨酯人工血管的顺应性

由激光测微器、压力传感器、A／D卡、微电脑和循环回路等组成的装置测定了小径人工血管的径向顺应性，由微注射器、压力传感器等组成的装置测定了体积顺应性，轴向顺应性由体积顺应性和径向顺应性计算出。体积顺应性，径向顺应性和轴向顺应性都随血管材料弹性的增大、盐／胶比的增加（孔隙率）和浸渍层数（血管壁厚度）的减小而增大。PU血管的外周模量与径向模量分别由径向顺应性。轴向顺应性计算，外周模量与径向模量之比值接近1，即两模量大小与变形方向无关。外周模量与径向模量随血管材料弹性和盐／胶比增加而变小。但管壁厚度对其的影响不大。通过合理选择更具弹性的PU材料（Chro佳，PCU1500次之），最佳盐／胶比例（6：1）以及控制浸渍层数（4～6层），可以制备出顺应性接近天然血管的小径人工血管。     

Characterization of cortical neuron outgrowth in two- and three-dimensional culture systems

To improve the ability of regeneration by grafting living cells or by adding growth factor to a lesion site, it is important to find good biomaterials for neuron survival and regeneration. This study focused on two- and three-dimensional cultures in a matrix using biomaterials such as agarose, collagen, fibrin, and their mixtures, because these are considered to be suitable biomaterials for neuron outgrowth. Cortical neurons were dissected from E17 rat embryos and cultured in agarose gel, collagen gel, fibrin glue, and mixtures of collagen and fibrin. Results showed that neurons cultured in collagen gel and fibrin glue had longer periods of survival (more than 3 weeks) and better neurite extension than those observed in agarose gels. As to the survival rate according to the MTT and lactate dehydrogenase assays, fibrin glue was the most suitable biomaterial for neuron survival among the biomaterials examined. With two-dimensional fibrin plating, neuron cells exhibited cell aggregation and stress fibers, but the same results were not observed with collagen gel. There were no differences in neurite extension and survival in the mixtures of collagen and fibrin. The results suggest that collagen and fibrin can provide a suitable substrate for a three-dimensional culture matrix for neuronal survival and differentiation.     

Molecular cloning and mutagenesis of a DNA locus involved in lipooligosaccharide biosynthesis in Haemophilus somnus

Haemophilus somnus undergoes antigenic and structural phase variation in its lipooligosaccharide (LOS). A gene (lob-1) containing repetitive 5'-CAAT-3' sequences that may, in part, contribute to phase variation was cloned and sequenced (T. J. Inzana et al., Infect. Immun. 65:4675-4681, 1997). We have now identified another putative gene (lob-2A) immediately upstream from lob-1. Lob-2A contained homology to several LOS biosynthesis proteins of the family Pasteurellaceae and the LgtB and LgtE galactosyltransferases of Neisseria meningitidis and N. gonorrhoeae. Unlike lob-1, lob-2A contained 18 to 20 5'-GA-3' repeats 141 bp upstream of the termination codon as determined by PCR amplification of DNA from individual colonies. Twenty repeats were most common, but when 19 5'-GA-3' repeats were present a stop codon would occur 1 bp after the last 5'-GA-3' repeat. A 630-bp SalI-BsgI fragment within lob-2A was deleted, and a kanamycin resistance (Km(r)) gene was inserted into this site to create pCAATDeltalob2A. Following electroporation of pCAATDeltalob2A into H. somnus 738, several allelic exchange mutants were isolated. The LOS electrophoretic profile of one mutant, strain 738-lob2A1::Km, was altered, and the phase variation rate was reduced but phase variation was not eliminated. A variant with 19 5'-GA-3' repeats in lob-2A had an LOS profile similar to that of 738-lob2A1::Km, suggesting that lob-2A was turned off in this phase. Nanoelectrospray mass spectrometry (nES-MS) and nuclear magnetic resonance spectroscopy showed that 738-lob2A1::Km was deficient in the terminal betaGal(1-3)betaGlcNAc residue present in parent strain 738. Mutant 738-lob2A1::Km was significantly more sensitive to the bactericidal action of normal bovine serum and was less virulent in mice than was parent strain 738. When H. somnus 129Pt was electrotransformed with shuttle vector pLS88 containing lob-2A, its LOS electrophoretic profile was modified and additional N-acetylhexosamine residues were present, as determined by nES-MS analysis. These results indicated that lob-2A may be an N-acetylglucosamine transferase involved in LOS biosynthesis and phase variation and that LOS structure is important to H. somnus virulence.     

Effect of IL-5, glucocorticoid, and Fas ligation on Bcl-2 homologue expression and caspase activation in circulating human eosinophils

IL-5 is a potent eosinophil viability-enhancing factor that has been strongly implicated in the pathogenesis of IgE-mediated inflammation in vivo. Recently published data have suggested that IL-5 (and related cytokines) may act by altering the expression of the anti-apoptotic regulator Bcl-2 or its homologues, but this is controversial. The behaviour of the recently described pro-apoptotic cysteine proteases (caspases) in eosinophils after IL-5 treatment has not been explored. We examined the effect of IL-5 on the expression of four major Bcl-2 homologues, as well as on the expression/activation of key members of the caspase cell death cascade in cultured circulating human eosinophils. The effect of relevant inducers of eosinophil apoptosis (glucocorticoid and Fas ligation) on these regulatory proteins was also examined. We observed baseline expression of the anti-apoptotic Mcl-1 and pro-apoptotic Bax proteins in immunoblots of eosinophil lysates, but not Bcl-x, Bcl-2. IL-5 treatment had the effect of maintaining this basal level of expression over time without altering the balance of Bcl-2 homologues. The (upstream) caspase 8 and (downstream) caspase 3 proenzymes were detected in eosinophils at baseline, and were processed during spontaneous and stimulated eosinophil death. IL-5 completely blocked caspase processing in spontaneous and dexamethasone-induced cell death, and significantly slowed processing during Fas ligation. Our data do not support the theory that IL-5 acts by altering the balance of anti-apoptotic and pro-apoptotic Bcl-2 homologues, but suggest that it may act by regulating activation of the caspase cell death cascade.