健康青少年口腔正常菌群的初步研究

本文采用非选择性培养基对22名健康青少年的唾液、沟裂菌斑、龈上菌斑及龈下菌斑中的需氧菌、兼性厌氧菌及专性厌氧菌进行了分离培养,并计算其在不同标本中占可培养菌的百分比及检出率。结果共分离到包括18个菌属的35种细菌。其中,链球菌、放线菌、奈瑟氏球菌、二氧化碳噬纤维菌、类杆菌、梭杆菌,奴卡氏菌及棒状杆菌在口腔4个部位的检出率及所占比例均较高,是健康青少年口腔中的优势菌群.通过比较还发现,其中一些菌在口腔4个部位的分布存在一定差异.本文还采用刚果红负性染色涂片法,镜下观察龈上、龈下菌斑中的螺旋体,并计算其相对比例.结果龈下菌斑中螺旋体的相对比例明显高于龈上菌斑.     

中药903口服液长期毒性实验研究

中药９０３口服液经药效学研究,表明该制剂具有良好的扶植正常菌群,调整微生态平衡,提高机体免疫能力的作用。对中药９０３口服液进行长期毒性实验研究结果证实,三种不同剂量组大白鼠给药前后的体重,血常规,主要脏器重量,肝、肾功能均无显著性差异。对４０例大鼠１１种脏器病理检查均未见药物损伤性病变。     

Function of the cytoskeleton in cells with microridges from the oral epithelium of the carp Cyprinus carpio

Superficial cells of the oral mucosal epithelium in the carp and the cytoskeleton of the epithelial cells are examined by scanning and transmission electron microscopy. Microridges are formed on the surface of the epithelium. Epithelial cells contain two types of vesicles: mucous secretory vesicles and coated vesicles. Most of the mucous vesicles are situated in the center of the cell near the Golgi apparatus. In freeze-fracture replicas, intramembranous particles are abundant in the membranes of the secretory vesicles but rare in the apical plasma membrane. Coated vesicles are situated in the apical and subapical cytoplasm. A great number of thick filaments, considered to be keratin filaments, run randomly throughout the cell to form a meshwork. Thick filaments, which are sparse in the central cytoplasm, are connected to the membranes of the secretory vesicles and other membranous organelles. A layer of closely packed thin filaments, considered to be actin filaments, is found just beneath the apical plasma membrane. Microtubules also occur in the apical cytoplasm and run almost parallel to the cell surface. Both kinds of vesicles are connected to the thin and thick filaments. Their functional significance in the regulation of membrane at the free surface is discussed.     

Analysis of effector T cells against the murine syngeneic tumor MethA in mice orally administered antitumor polysaccharide SPR-901

The growth of MethA tumor was significantly inhibited by oral administration of the -glucan SPR-901 in BALB/c (+/+) mice but not in nude mice. Mice treated orally with SPR-901 exhibited an augmentation of antigen-specific resistance against rechallenge with the tumor cells. The tumor-neutralizing activity of regional lymph node cells from MethA-bearing mice against the tumor was augmented by oral administration of SPR-901. The tumor-neutralizing activity of lymph node cells from SPR-901-treated mice mainly appeared in Lyt2+cells. Furthermore, lymphokine-activated killer activity of these cells was enhanced by administration of SPR-901. The antitumor effect of SPR-901 was abrogated in mice depleted of either L3T4+ or Lyt2+ cells, and in cyclosporin-A-treated mice. These results suggest that Lyt2+ cells are important effector cells in MethA-bearing mice orally adminstered SPR-901 and that functional exertion of both Lyt2+ and L3T4+T cells is necessary for the antitumor effect of orally administered SPR-901 in vivo.     

伤寒-鼠伤寒重组株Vi4072在小鼠中定居及血清学效果观察试验

将编码Vi抗原的基因克隆到减毒的鼠伤寒沙门氏菌中组建的基因重组株Vi4072,以3×10~8CFU一次口服感染Balb/C小鼠,4天后按7,14,21,28,35,42,49,56,63,70天的间隔收集分离小鼠的集合淋巴结,肝,脾.鉴别是否有本菌出现,并检测血清和小肠匀浆液中的vi抗体.结果表明,感染后49天仍可从脾中分离到该菌;70天仍可从血清和小肠匀浆液中测出vi抗体。     

The development of oral vaccines based on live attenuated Salmonella strains

Abstract Safe, live attenuated Salmonella strains can be produced by introducing defined non-reverting mutations into the chromosome. Such rationally attenuated strains have proved to be excellent oral vaccines in several animal species and can therefore be considered as candidate vaccines against invasive salmonellosis in both animals and man. A panel of attenuating lesions is now available from which it is possible to tailor the level of attenuation and hence produce strains with different immunogenic properties. Because of the spectrum of immune responses produced by such Salmonella vaccine strains they have been utilised extensively as vectors for delivering heterologous antigens to the mammalian immune system. We have focussed on the development of a single dose oral tetanus vaccine based on attenuated Salmonella strains expressing a non-toxic, immunogenic protein derived from tetanus toxin (fragment C). Several different expression systems have been used for fragment C and candidate vaccine strains have been constructed that are capable of protecting orally immunised mice against a lethal challenge with tetanus toxin. An oral tetanus vaccine may help to reduce the mortality rate from tetanus in the developing world by overcoming the problems associated with the implementation of vaccine programmes using the current parenteral vaccine.     

Organization of the intercellular spaces of porcine epidermal and palatal stratum corneum: a quantitative study employing ruthenium tetroxide

Previous studies have demonstrated that the intercellular spaces of the stratum corneum contain multilamellar lipid sheets with variable ultrastructure in addition to desmosomes or desmosomal remnants. The intercellular lamellae are thought to provide a permeability barrier whereas the desmosomes are responsible for cell-cell cohesion. In this study, transmission electron microscopy of RuO₄-fixed tissue was used to compare the proportions of the intercellular spaces in epidermal and palatal stratum corneum occupied by desmosomes and by different patterns of lamellae. Desmosomes are more abundant in palatal than in epidermal stratum corneum (46.9 vs 15.0% length of intercellular space). In epidermis the most frequent lamellar arrangements involve 3 (23.5%) or 6 (24.2%) lucent bands with an alternating broad-narrow-broad pattern, whereas the most frequent lamellar arrangements in palatal tissue are 2 (17.2%) or 4 (10.5%) lucent bands of uniform width. Most of the nondesmosomal portion of the intercellular space in palatal stratum corneum was dilated and had elongated lamellae at the periphery and short disorganized lamellae and amorphous electron-dense material in the interior. It is concluded that the multilamellar lipid sheets are less extensive in palatal than in epidermal stratum corneum, which could explain the greater permeability of the palate.     

Early hominid feeding mechanisms.

Three predominant influences mark the evolution of human head form: big brain, erect bipedalism, modified oral apparatus. Confusing interplay between different adaptive requirements of each feature has made explanation of skull structure extremely difficult in the past. It now seems possible to isolate each influence in early fossil forms. A model of mammalian modes of feeding adaptation is proposed in the form of a “Natural Experiment” for tighter analysis of fossil forms. Two forms of australopithecines are recognized, “gracile” and “robust.” Both had closely similar brains, both had erect bipedalism, but each had different masticatory construction. Separation of the first two similar influences isolates the adaptive differences in oral mechanics. The gracile form had a projecting oral apparatus, distinct canine and zygomatic buttresses, moderate jaw-lever development, jaw joint not unlike most higher primates, large unusual anterior teeth, moderately sized posterior teeth. The robust form had a retruded, greatly deepened oral apparatus, “dished-in” face with fused canine and zygomatic buttresses, powerful jaw-lever development, distinctively different joint construction, remarkably small anterior teeth, enormous posterior teeth. Striking evidence for extraordinary jaw movements emerges from these features in the robust form. This is strongly supported by remarkably close parallels in Ursidae: grizzly bear and giant panda.     

The identification of dimethylphenylarsine as a microbial metabolite using a simple method of chemofocusing

Candida humicola acts on benzenearsonic acid to produce dimethylphenylarsine, which was identified by mass spectroscopy following the chemofocusing of the volatile metabolite onto a mercuric chloride impregnated filter. The same technique established that trimethylarsine is the volatile metabolic product obtained from C. humicola treated with 4-NH₂-2-OHC₆H₃AsO(OH)₂ and (CH₃)₃AsO. Arsanilic acid, 4-NH₂C₆H₄AsO(OH)₂, is not metabolized to a volatile arsine.     

化学修饰提高胰岛素口服降血糖作用的研究

本文探索了用小分子化合物对胰岛素进行化学修饰,以增加口服降血糖的可能性.制备了乙酰胰岛素、琥珀酰胰岛素和半乳糖酰胰岛素.这些胰岛素不仅较好地保持了天然胰岛素的活性,而且其口服降血糖作用也较天然胰岛素明显增加,其中琥珀酰胰岛素是天然胰岛素的口服降血糖作用的二倍以上.这为口服或肛门给药的胰岛素新剂型的研制提供了科学依据.