Establishment and characterization of ferret cells in culture

Summary Cells derived from the brain of a 6 wk-old ferret have been subcultured over 100 times and have undergone over 400 population doublings in vitro. These cells, referred to as Mpf cells, have an absolute efficiency of colony formation in excess of 45%, exhibit a mean population doubling time of 12.5 h, possess ferret-specific antigens, and have isozymes with electrophoretic properties that are the same as those of isozymes found in ferret liver. The cells exhibit a cytopathic effect and support the synthesis of progeny virus when they are infected with the viruses of lymphocytic choriomeningitis, Newcastle disease, pseudorabies, Sindbis, vaccinia, and vesicular stomatitis. The passage level of the Mpf cells, their elapsed number of population doublings, their possession of ferret-specific antigens, and the comigration of four isozymes obtained from these cells and ferret liver define the cells as an established line of ferret cells.     

Application of (S)‐TBMB carboxylic acid‐based on‐line HPLC‐exciton CD analysis to acyclic vicinal alcohols and amino alcohols

Applications of the on‐line HPLC‐exciton CD analysis using (S)‐2‐tert‐butyl‐2‐methyl‐1,3‐benzodioxole‐4‐carboxylic acid [(S)‐TBMBC‐OH] that can simultaneously determine the enantiomeric compositions and the absolute configuration of cyclohexane‐1,2‐diols and diamines as well as acyclic vicinal diols and amino alcohols were studied. Di‐O‐ or di‐N,O‐(S)‐TBMBC derivatives of acyclic terminal vicinal diols, 2‐hydroxy‐1‐amines, and nonterminal vicinal diols gave symmetrical exciton CD spectra between enantiomers, indicating their absolute configurations. However, Di‐N,O‐(S)‐TBMBC derivatives of 2‐amino‐1‐ols did not always give symmetrical exciton CD spectra between enantiomers, but their 2‐phthalimido‐1‐O‐(S)‐TBMBC derivatives gave symmetrical exciton CD spectra, indicating their absolute configurations. All these (S)‐TBMBC derivatives were separated by normal‐phase HPLC and unequivocally determined by the on‐line HPLC‐exciton CD analysis without recourse to reference samples. Chirality 11:149–159, 1999. © 1999 Wiley‐Liss, Inc.     

The CholecystokininB Receptor Is Coupled to Two Effector Pathways Through Pertussis Toxin-Sensitive and -Insensitive G Proteins

Previous binding studies have suggested the existence of two affinity states for type B cholecystokinin receptors (CCK(B)R), which could correspond to different coupling states of the receptor to G proteins. To test this hypothesis, we have further investigated signal transduction pathways coupled to rat CCK(B)R stably transfected in Chinese hamster ovary cells. We show that CCK(B)R are coupled to two distinct transduction pathways involving two different G proteins, a pertussis toxin-insensitive/phospholipase C pathway leading to the production of inositol phosphate and arachidonic acid, and a pertussis toxin-sensitive/phospholipase A2 pathway leading to the release of arachidonic acid. We further demonstrate that the relative degree of activation of each effector pathway by different specific CCK(B)R agonists is the same, and that a specific CCK(B)R antagonist, RB213, can differentially antagonize the two signal transduction pathways elicited by these agonists. Taken all together, these data could be explained by the recently proposed theory assuming that the receptor can exist in a three-state model in which two active conformations corresponding to the complex formed by the receptor with two different G proteins coexist. According to this model, agonists or antagonists could recognize preferentially either conformation of the activated receptor, leading to variable behavior in a system containing a single receptor type.     

Establishment of a System with High Synchronous Frequency of Somatic Embryogenesis and Embryo Seedling Formation in Camellia sinensis var. assamica

The system of high synchronous frequency of somatic embryogenesis and somatic embryo seedling formation was established by means of embryonic cell hne 1 ( CL1 ) of Camellia sinensis var. assamica Kitamura. Modified MS was used as the basic medium. Cultures of CL1 was transferred to the aqueous induced medium (0.05 mg/L 2,4-D + 0.50 mg/L 6-BA) from the maintenance medium (0.1 mg/L 2,4-D + 0.5 mg/L 6-BA) for somatic embryos induction under dark condition. 28 days later, they were cultured in the liquid differentiation medium. Various kinds of somatic embryos were obtained after another 28 days. The frequency of somatic embryos was 81.5 %. Various mesh sizes of sieves were applied to collect the somatic embryos in different developmental stages which could develop to mature stage in the aqueous growth medium ( 1/2 MS + 1.0 mg/L GA3 + 0.5 mg/L 6-BA). ABA was effective to promote the formation of highly qualified somatic embryo. The mature somatic embryos sized 20 to 70 mesh had the conversion frequency 75 %. The development of somatic embryogenesis studied under a cell suspension culture system was similar to the zygotic embryogenesis.     

辽宁满族和汉族指纹白线正常值分析

本文研究了1060例 (满族：460,汉族：600;男女各半) 满族和汉族指纹白线。满族和汉族指纹白线出现率分别是7.11％和31.73％。结果表明民族间的指纹白线有他们各自的特征并做了性别和手别间差异的比较分析。     

Spatial development of the cultivation of a bone marrow stromal cell line in porous carriers

The spatial development of the cultivation of a bone marrow stromal cell line (SR-4987) in porous carriers was investigated in order to construct a three-dimensional hematopoietic culture system. Low-rate continuous agitation, 20 rpm, was an appropriate method to achieve initial adhesion of cells onto a cellulose porous beads (CPB, 100 μm pore diameter) in a spinner bottle, compared with other methods such as centrifugation and intermittent agitation. Cell growth with continuous agitation at 70 rpm after initial cell adhesion was not inferior to that at 20 rpm. A 2- and 10-fold increase in the inoculum cell concentration for CPB and another type of porous cellulose beads (Micro-cube (MC), 500 μm pore diameter) resulted in a 1.2- and 2-fold increase in final cell concentrationm, respectively. Cells attached to the MC beads and a polyester nonwoven dic (Fibra-cell (FC)) could grow and spread well on the carriers and a fibroblast-like shape was observed under scanning electron microscopy while the cells on CPB were globular. The flatness and inner surface area of these carriers may be the reason for the differences in cell morphology. This revised version was published online in July 2006 with corrections to the Cover Date.     

Tissue culture adherence and haemagglutination characteristics of Moraxella (Branhamella) catarrhalis

The haemagglutination and tissue culture adherence properties of 20 isolates of Moraxella catarrhalis obtained from the sputum of elderly patients with lower respiratory tract infections were compared with those of 20 isolates of M. catarrhalis obtained from the nasopharynx of elderly persons colonised by the organism. Eighty percent of isolates from the infected group as opposed to 5% of isolates from the colonised group haemagglutinated human erythrocytes (P < 0.001), indicating that the haemagglutinin might be a marker of pathogenicity for M. catarrhalis. There was a significant difference in the adherence to HEp-2 cells of isolates from the infected group in comparison to isolates from the colonised group (P = 0.03). Haemagglutination and tissue culture adherence properties were unrelated, indicating that separate adhesin systems are involved. The adherence of M. catarrhalis to HEp-2 cells was unaffected following pronase and trypsin treatment, however, sodium periodate pre-treatment of the bacteria significantly reduced the tissue culture adherence index, indicating that the adhesin by which the bacteria bind to HEp-2 cells may have a carbohydrate moiety. Transmission electron microscopy studies revealed that adherence of M. catarrhalis to HEp-2 cells was mediated by trypsin-resistant 'tack-/spicule-like' structures protruding from the surface of the bacteria.     

Morphology of the mechanosensory lateral line system in the Atlantic Stingray,Dasyatissabina: The mechanotactile hypothesis

The biological function of anatomical specializations in the mechanosensory lateral line of elasmobranch fishes is essentially unknown. The gross and histological features of the lateral line in the Atlantic stingray, Dasyatis sabina, were examined with special reference to its role in the localization and capture of natural invertebrate prey. Superficial neuromasts are arranged in bilateral rows near the dorsal midline from the spiracle to the posterior body disk and in a lateral position along the entire length of the tail. All dorsal lateral line canals are pored, contain sensory neuromasts, and have accessory lateral tubules that most likely function to increase their receptive field. The pored ventral canal system consists of the lateral hyomandibular canal along the disk margin and the short, separate mandibular canal on the lower jaw. The extensive nonpored and relatively compliant ventral infraorbital, supraorbital, and medial hyomandibular canals form a continuous complex on the snout, around the mouth, and along the abdomen. Vesicles of Savi are small mechanosensory subdermal pouches that occur in bilateral rows only along the ventral midline of the rostrum. Superficial neuromasts are best positioned to detect water movements along the transverse body axis such as those produced by tidal currents, conspecifics, or predators. The pored dorsal canal system is positioned to detect water movements created by conspecifics, predators, or possibly distortions in the flow field during swimming. Based upon the stingray lateral line morphology and feeding behavior, we propose the Mechanotactile Hypothesis, which states that the ventral nonpored canals and vesicles of Savi function as specialized tactile mechanoreceptors that facilitate the detection and capture of small benthic invertebrate prey. J. Morphol. 238:1–22, 1998. © 1998 Wiley-Liss, Inc.