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1.
In n previous report dealing with the pathology of bovine fascio-liasis the author described an unknown cell type in the epithelium of bile ducts. The histological and histochemical investigations published in this paper suggest that the cell may be considered a globule leukocyte. Globule leukocytes are rare in uninfected livers but are occurring in abundance in main bile ducts of cattle with spontaneous fascioliasis and also in small perilobular ducts in dicrocoeliasis. Liver fluke infection causes an increase in the population of subepithelial mast cells. Mast cell and globule leukocyte present similarities In their cytochemical properties. However, at low pH toluldinc blue shows a stronger but Alcian blue a weaker affinity for mast cells than for globule leukocytes.  相似文献   
2.
The bacterial flagellum is composed of more than 20 different proteins. The filament, which constitutes the major extracellular part of the flagellum, is built up of approximately 20,000 FliC molecules that assemble at the growing distal end of the filament. A capping structure composed of five FliD molecules located at the tip of the filament promotes polymerization of FliC. Lack of FliD leads to release of the subunits into the growth medium. We show here that FliD can be successfully used in bacterial surface display. We tested various insertion sites in the capping protein, and the optimal region for display was at the variable region in FliD. Deletion and/or insertion at other sites resulted in decreased formation of flagella. We further developed the technique into a multihybrid display system in which three foreign peptides are simultaneously expressed within the same flagellum, i.e., D repeats of FnBPA from Staphylococcus aureus at the tip and fragments of YadA from Yersinia enterocolitica as well as SlpA from Lactobacillus crispatus along the filament. This technology can have biotechnological applications, e.g., in simultaneous delivery of several effector molecules.  相似文献   
3.
Sex-steroid-sensitive stromal cells and oviduct differentiation   总被引:1,自引:0,他引:1  
The chick oviduct differentiates during sexual maturation before the age of 20 weeks. In the present work we used immunohistochemistry to study sexual maturation associated progesterone receptor (PR) expression in the chick oviduct as an indication of progesterone sensitivity. Since the PR is estrogen inducible protein, its expression also reflects the effects of endogenous estrogens. Thus PR expression can be used as a marker for action and sensitivity of cells to these sex steroids. In the luminal epithelium and mesothelium (peritoneal epithelium) the PR was expressed in high concentrations from the time before hatching (the constitutive PR). The PR was not detectable in stromal cells of immature chicks. At the age of 7-10 weeks the PR was detected in submucosal but not in mucosal stromal cells (the inductive PR). The appearance of these PR-expressing cells was associated with an increase in luminal epithelial cell proliferation. At the age of 14-16 weeks the mucosal plicae increased in height and the PR-expressing stromal cells were seen in the center of these mucosal plicae. There were also areas in the mucosal plicae where a large number of stromal cells expressing the PR were seen in the mucosal layer. Thereafter the size of the oviduct increased rapidly and the gland formation commenced. In the fully matured oviduct (over 18 weeks of age) virtually all stromal cells both in mucosa and submucosa expressed the PR. It is concluded that the PR expression in the luminal epithelium and mesothelium was constitutive (independent of sexual maturation). In stromal cells this was expressed during sexual maturation (probably induced by endogenous estrogen) and was associated with histological changes in the oviduct. We propose that direct effects of estrogen and progesterone in the oviduct growth and glandular formation are mediated through these stromal cells.  相似文献   
4.
5.
The garnet-type phase Li7La3Zr2O12 (LLZO) attracts significant attention as an oxide solid electrolyte to enable safe and robust solid-state batteries (SSBs) with potentially high energy density. However, while significant progress has been made in demonstrating compatibility with Li metal, integrating LLZO into composite cathodes remains a challenge. The current perspective focuses on the critical issues that need to be addressed to achieve the ultimate goal of an all-solid-state LLZO-based battery that delivers safety, durability, and pack-level performance characteristics that are unobtainable with state-of-the-art Li-ion batteries. This perspective complements existing reviews of solid/solid interfaces with more emphasis on understanding numerous homo- and heteroionic interfaces in a pure oxide-based SSB and the various phenomena that accompany the evolution of the chemical, electrochemical, structural, morphological, and mechanical properties of those interfaces during processing and operation. Finally, the insights gained from a comprehensive literature survey of LLZO–cathode interfaces are used to guide efforts for the development of LLZO-based SSBs.  相似文献   
6.
The influence of different estrogen and/or progesterone treatments on concentrations of A and B forms of progesterone receptor (PR-A and PR-B) in the different cell types of chick oviduct was studied. A semiquantitative immunohistochemical assay for cellular PR concentrations was developed using a computer-assisted image analysis system. The staining intensity of nuclear PR in the basal layer of epithelial cells, glandular, smooth muscle and mesothelial cells was analysed separately using two monoclonal antibodies, PR6 and PR22. The measured concentrations of PR varied between different cell types and from cell to cell. A significant decrease in PR concentration, as noted by a decrease in staining intensity, was observed in all cell types studied 2 or 6 h after a single injection of progesterone with or without simultaneous estrogen administration. The decrease was also verified with immunoblotting and an immunoenzymometric assay (IEMA) for chicken PR. After down-regulation the concentration of PR recovered to the control level within 48 h after progesterone or estrogen administration. Estrogen administration alone was observed to cause changes in the concentration of PR-A only, having little or no effect on PR-B concentration depending on the cell type studied.

These findings indicate that estrogen and progesterone cause cell-specific changes not only to the total concentration of PR but also to the cellular ratio of PR-A and PR-B.  相似文献   

7.
Electron absorption and equilibrium of the Schiffs bases prepared between pyridoxal 5′-phosphate (PLP) and dodecylamine (DODA) or some other shorter chain amines have been studied in nonionic and cationic micellar solutions with various pH of the bulk solution. In the presence of the nonionic (Triton X-100) micelles the Schiffs bases formed between PLP and DODA were embedded into the micelles because the absorption occured at 335 nm, indicative of the nonpolar milieu. This absorption was constant at pH 5–10. At pH 3–5, the tautomeric form absorbing at 415 nm appeared. This resembles the titration of glycogen phosphorylate or that of Schiffs bases in methanol. Short chain amines absorbed at 415 nm, which is typical of Schiffs bases in aqueous solutions. Tryptophan also absorbed first at 415 nm but the absorption changed to 325 nm with a half-time of ~20 min. This was interpreted as being due to formation of the cyclic structure catalysed by micelles. The pH-dependent equilibrium constant of the reaction between PLP and DODA in Triton X-100 solution had a maximum at pH9, the value being 3500 M?1, about ten times greater than the value of ethylamine at the same pH. Spectral properties of PLP-DODA imines in the cationic micelles (cetyltrimethylammonium bromide) resembled those in the nonionic micelles, except that at low pH the absorption peak in the 415 nm region did not appear. The equilibrium constant of PLP-DODA had maximum at pH 9, the value being as high as 118000 M?1. Different properties of nonionic and cationic micelles and the design of micellar model systems of PLP enzymes are discussed.  相似文献   
8.
9.
The photosynthetic activity of different algal communities at the outer edge of an Equisetum fluviatile L. stand in an oligotrophic lake (Pääjärvi, in southern Finland) was investigated. Production by the algal communities was measured simultaneously using a modified 14C-method, and the results were related to the volume of algae and the available irradiance. The relative production rate (P/B quotient) of phytoplankton was ca. 3 × that of epiphyton and ca. 20 × that of epipelon. Epiphyton productivity remained almost constant although the algal volume varied greatly, suggesting that the surface layer of the algal community was mainly responsible for the photosynthetic activity. In the littoral area (at 1 m depth) primary production/m2 of lake surface by phytoplankton, epiphyton and epipelon was similar but in the littoriprofundal area (2–4 m) phytoplankton production was twice that of epipelon. Primary productivity of epiphyton and epipelon/m2 of substratum was about equal to phytoplankton productivity/m3 of water at the same irradiance. This relation provided a means of estimating the relative contributions of the different algal communities to the total algal production in the lake.  相似文献   
10.
Summary The distribution of substance P (SP) immunofluorescence was investigated in the Gasserian ganglion, ophthalmic nerve and in the anterior segment of the rabbit eye. About one third of the nerve cell bodies in the Gasserian ganglion exhibited SP immunofluorescence, which was also observed in some nerve fibres of the ophthalmic nerve. In the cornea, some SP-positive iris contained numerous nerve fibres with SP immunofluorescence. In the sphincter area such fibres were circular, while the orientation of the SP fibres was radial in the dilator muscle. Both in the iris and in the ciliary body, the largest vessels were surrounded by nerves exhibiting SP immunofluorescence. A few nerve fibres also appeared in the stroma of the ciliary processes.  相似文献   
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