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  • Articles  (17)
  • Human  (17)
  • Springer  (17)
  • American Institute of Physics (AIP)
  • Oxford University Press
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  • 1995-1999  (17)
  • 1999  (17)
  • Medicine  (17)
  • Physics
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  • Articles  (17)
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  • Springer  (17)
  • American Institute of Physics (AIP)
  • Oxford University Press
  • Wiley
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  • 1995-1999  (17)
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 185 (1999), S. 297-304 
    ISSN: 1432-1351
    Keywords: Key words Odor coding ; Learning ; Enhanced sensitivity ; Rabbit ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The olfactory system is faced with a particular problem – the high dimensionality and inherent unpredictability of the chemical world. Most natural odorants encountered in everyday life are complex mixtures of many different volatiles. This means that from the outset the olfactory system has to contend with a great and often unpredictable diversity of molecules, making it difficult for stable primary features of the chemical world to be mapped onto the sensory surface. One solution to such unpredictability is provided by learning. Learning confers flexibility, enabling individuals of a given species to acquire and make use of the most appropriate information in a particular environment. Two examples of this are presented: learning of maternal odors in neonatal rabbits, including evidence that the sensory surface itself may be influenced by environmental conditions so as to enhance sensitivity to molecules of particular ecological relevance, and cross-cultural human studies suggesting that experience with everyday odors influences not only the way these are evaluated, but also their perceived intensity. It is concluded that an adequate understanding of odor coding and olfactory function will not be possible without taking such experience-dependent factors into account.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Immunogenetics 49 (1999), S. 438-445 
    ISSN: 1432-1211
    Keywords: Key words PA28 ; Proteasome ; Gene structure ; Evolution ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Two proteasome activators PA28α and β, which have been implicated in antigen processing for loading class I MHC molecules, are synthesized in response to Ifn-γ. The human genes encoding these activators (PSME1 and PSME2, respectively) were analyzed by sequencing. Each gene comprised 11 exons, consistent with gene duplication during vertebrate evolution. The intron/exon organization of both genes was highly conserved, the major difference being the absence of the exon encoding the lysine and glutamic acid-rich 'KEKE' motif in PA28β. Two other genes of relevance to the immune system were located close to those for PA28 at 14q11.2 including ISGF3G, a protein involved in transcription after IFNα signalling. These sequences were also characterized.
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  • 3
    ISSN: 1432-1211
    Keywords: Key words NK cells ; Human ; Surface molecule ; Lectin superfamily ; NK gene complex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Natural killer (NK) cells constitute the third major population of lymphocytes. They possess the inherent capacity to kill various tumor and virally infected cells and mediate the rejection of bone-marrow grafts in lethally irradiated animals. A large family of NK cell receptors belong to the C-type lectin superfamily and are localized to the NK gene complex on Chromosome (Chr) 6 in the mouse and Chr 12 in the human. Genes in the NK gene complex encode type II receptors and examples include the families of NKR-P1, Ly-49, and NKG2 receptors. Examples of other C-type lectin-like NK cell receptors that occur as individual genes are CD94, CD69, and AICL. Here we report the molecular characterization and chromosomal mapping of a human lectin-like transcript (LLT1) expressed on NK, T, and B cells and localized to the NK gene complex within 100 kilobases of CD69. The cDNA encodes a predicted protein of 191 amino acid residues with a transmembrane domain near the N-terminus and an extracellular domain of 132 amino acid residues with similarity to the carbohydrate recognition domain of C-type lectins. The predicted protein of LLT1 shows 59 and 56% similarity to AICL and CD69, respectively. The predicted protein does not contain any intracellular ITIM motifs, suggesting that LLT1 may be involved in mediating activation signals.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 55 (1999), S. 349-352 
    ISSN: 1432-1041
    Keywords: Key words Ischaemic stroke ; Vinpocetine ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objectives: To determine whether vinpocetine decreases short- and long-term case fatality and proportion of dependent survivors if administered within 2 weeks of stroke onset. Methods: All published and unpublished trials were attempted to be identified using the standard search strategy of the Cochrane Collaboration Stroke Review Group, using MEDLINE searches performed with all known manufacturer code names and trade names of vinpocetine and by contacting manufacturers of vinpocetine to give information of all randomised controlled trials on vinpocetine in stroke. Researchers who participated in trials on vinpocetine in Hungary were asked for further information. Only truly randomised, unconfounded clinical trials that compared the effect of vinpocetine to either placebo or another reference treatment for acute stroke where treatment started no later than 14 days after stroke onset were eligible for inclusion. Data synthesis and analysis was performed using the Cochrane Review Manager software (RevMan version 3.0). Results: Among the identified studies on vinpocetine in stroke, only one fulfilled the selection criteria for inclusion in the review. No death occurred in the study groups and no statistically significant difference was found in dependency between the treatment and the placebo groups. No adverse effects were reported. Conclusions: Based on only one small randomised controlled unconfounded study, presently there is not enough evidence to decide whether the administration of vinpocetine does or does not decrease case fatality and dependency in acute stroke.
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  • 5
    ISSN: 1432-0878
    Keywords: Key words Apoptosis ; p53 ; Ischemia ; Enterocytes ; Proliferation ; Differentiation ; ISEL ; Glomeruli ; Mouse (Balb/c) ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Morphological changes associated with apoptosis are closely correlated with the expression of specific proteins. However, the cause-effect relationships between the expression of these proteins and DNA degradation are barely known. For studying expression of apoptosis-related proteins in relation to different degrees of DNA fragmentation, the small intestine with its spatially organized continuum of proliferation, differentiation and death is a very useful preparation. Enterocytes towards the apex of the villi become increasingly susceptible to apoptosis. Here, this ”apoptotic gradient” is used to demonstrate the presence of BAX and BCL-2 proteins in the cytoplasm of cells at the onset of apoptosis. In semithin serial sections of the small intestine, BAX, BCL-2 and DNA fragmentation were demonstrated. BAX and BCL-2 are always colocalized and only in cells with fragmented DNA. The gradient of BAX or BCL-2 staining is similar to the gradient of DNA fragmentation. Immunoreactivity for BCL-2 or BAX is most intense in cells that are prone to become apoptotic next in the course of cellular turnover but not in cells in an advanced apoptotic state, showing strongly condensed chromatin. When using the same technique on semithin sections of kidney biopsies, containing epithelia with low cellular turnover, we found DNA fragmentation mainly in the epithelial cells of the distal tubules. Similar to the situation in the enterocytes, BAX staining was confined to the cytoplasm of epithelial cells with a moderate degree of DNA fragmentation and reduced in epithelial cells with a high degree of DNA fragmentation. In contrast to the situation in the small intestine, very low levels of BCL-2 were found. The results suggest that expression of BCL-2 and BAX is related to cell damage as indicated by DNA fragmentation but not to advanced stages of cellular death, as indicated by chromatin condensation and cellular shrinkage.
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  • 6
    ISSN: 1432-0878
    Keywords: Key words Vesicle protein ; Physin ; Secretory carrier-associated membrane protein ; Vesicle-associated membrane protein ; Synaptobrevin ; Expression ; Liver ; Bovine ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The cell-type restricted expression of cytoplasmic microvesicle membrane protein isoforms may be a consequence of the functional adaptation of these vesicles to the execution of specialized processes in cells of different specialization. To characterize the expression of the vesicle protein pantophysin, an isoform of the synaptic vesicle proteins synaptophysin and synaptoporin, we have prepared and characterized antibodies useful for the immunological detection of pantophysin in vitro and in situ. Using these reagents, we show by immunoblot analyses that pantophysin expression is not homogeneous but differs significantly between various bovine tissues. Furthermore, these differences are not exactly paralleled by the expression of other vesicle proteins of the SCAMP (secretory carrier-associated membrane protein) and VAMP (vesicle-associated membrane protein) types that have previously been localized to pantophysin vesicles in cultured cells. By immunofluorescence microscopy, pantophysin expression is seen predominantly in non-neuroendocrine cells with pronounced membrane traffic. Pantophysin staining codistributes with SCAMP and VAMP immunoreactivities in most instances but differs in some. Remarkably, pantophysin staining in liver is restricted to cells surrounding sinusoids and is not detectable in hepatocytes, similar to that of the SCAMP and VAMP isoforms as detected by our reagents in tissue sections.
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  • 7
    ISSN: 1432-0878
    Keywords: Key words Mammary gland ; Differentiation ; Neoplasia ; Homeodomain ; Cancer ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  In the mouse mammary gland, homeobox gene expression patterns suggest roles in development and neoplasia. In the human breast, we now identify a family of Iroquois-class (IRX) homeobox genes. One gene, IRX-2, is expressed in discrete epithelial cell lineages being found in ductal and lobular epithelium, but not in myoepithelium. Expression is absent from associated mesenchymal adipose stroma. During gland development, expression is concentrated in terminal end buds and terminal lobules and is reduced in a subset of epithelial cells during lactation. In contrast to observations for many homeobox genes in the mouse mammary gland in which homeobox gene expression is lost on neoplastic progression, IRX-2 expression is maintained in human mammary neoplasias. Data suggest IRX-2 functions in epithelial cell differentiation and demonstrate regulated expression during ductal and lobular proliferation as well as lactation.
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  • 8
    ISSN: 1432-0878
    Keywords: Key words Cytokine ; ELISA ; FACScan ; Lipids ; Macrophage ; Monocyte ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Diabetes (type I and type II) affects approximately 13 million people in the United States. Delayed and incomplete healing of wounds can be a major problem for diabetic patients. Macrophages are an important cell in the complex process of wound repair representing the major source of cytokines throughout the wound-healing process. Cytokines mediate many of the cellular responses critical to timely wound repair. It has been suggested that diabetes impairs wound healing through disruption of local cytokine production. Our previous in vivo studies in rats demonstrated that diabetes-induced and diet-induced hyperlipidemia cause changes in macrophage phenotype and function (Iacopino 1995; Doxey et al. 1998), suggesting that alterations in macrophage cytokine profiles represent the cellular/molecular mechanism responsible for delayed wound healing. The purpose of this study was to investigate how monocyte maturation/differentiation and cytokine production were altered by serum lipids in an in vitro system using human cells. Commercially prepared purified human monocytes were cultured and exposed to serum lipids. Phenotypic analysis of differentiated macrophages was then performed by flow cytometry and fluorescent microscopy using surface antigens specific for various macrophage subsets. Selected cytokines in conditioned medium were assayed using commercial human enzyme-linked immunosorbent assay (ELISA) kits. We demonstrate that serum lipids cause an increase in monocytic differentiation leading to an inflammatory macrophage phenotype rather than a reparative/proliferative phenotype. We also show that serum lipids cause a generalized decrease in macrophage cytokine production using interleukin-1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), platelet-derived growth factor (PDGF), and transforming growth factor beta 1 (TGF-β1) as marker cytokines. Our present in vitro results using human cells confirm our previous in vivo studies in the rat and support the hypothesis that diabetes-induced hyperlipidemia alters the monocyte differentiation process resulting in changes of macrophage subsets and cytokine release at the wound site, ultimately impairing the wound-healing process.
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  • 9
    ISSN: 1432-0878
    Keywords: Key words Cultured epidermis ; Keratinocyte ; Epithelialization ; Wound healing ; Human ; Mouse (NMRI)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Sheets of cultured allogeneic human keratinocytes have been used for the treatment of burns and chronic leg ulcers but there has been no animal assay for the therapeutic action of these cultures. In order to analyze the effects of frozen cultures of human keratinocytes on wound healing, we have developed such an assay based on the rate of repair of full-thickness skin wounds in immunocompetent NMR1 mice. Reepithelialization of the control wounds, originating from the murine epithelium at the edge of the wound, occurred at a constant rate of advance of 150 µm/day. When frozen cultured human epidermal sheets were thawed at room temperature for 5–10 min and applied to the surface of the wound, the murine epithelium advanced at 267 µm/day. Most wounds treated with frozen cultures completely healed after 10 days, whereas most control wounds required 16 days. The accelerated reepithelialization did not depend on the presence of proliferative human keratinocytes in the frozen cultures. The cultures also promoted early formation of granulation tissue and laminin deposition over the surface of the wound bed. This simple assay should permit quantitative analysis of the effects on healing exerted not only by cultured cells, but also by proteins and small molecules.
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  • 10
    ISSN: 1432-0878
    Keywords: Key words Interleukin-18 ; Hyperosmotic conditions ; Epithelial cells ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Interleukin-18 is a novel multifunctional cytokine, which enhances natural killer cell activity and promotes the induction of cytokine production, including that of interferon-γ by T cells and antitumor effects. Interleukin-18 is produced by cells of several different tissues (e.g., macrophages, keratinocytes, osteoblasts, and intestinal epithelium); however, it is unclear what physiological conditions or stimuli induce interleukin-18 production. To determine physiological conditions for the production of interleukin-18, we have examined the effect of mannitol-induced hyperosmotic conditions on normal human umbilical vein endothelial cells (HUVEC) and eight established human epithelial-like cell lines (Intestine 407, Caco-2, A253, HeLa, SCC25, HT1197, ACHN, A549). Hyperosmotic conditions induced interleukin-18 immunoreactivity in all the human cell lines tested, as detected by immunocytochemistry. The enhanced interleukin-18 production was also observed when mannitol was replaced with NaCl as the inducer of hyperosmotic stress. Enzyme-linked immunosorbent assays revealed that interleukin-18 concentrations in cell extracts were significantly increased by hyperosmotic conditions. Reporter gene assays also revealed that hyperosmotic conditions stimulated transcriptional activity of the interleukin-18 promoter. These results show for the first time that hyperosmotic stress is a stimulator of interleukin-18 production in epithelial-like cells.
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  • 11
    ISSN: 1432-0878
    Keywords: Key words α1-Microglobulin ; Bikunin ; Inter-α-trypsin inhibitor ; Mast cells ; Trypstatin ; Urinary trypsin inhibitor ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  We recently reported that the rat mast cell proteinase inhibitor trypstatin is genetically identical with the second half of inter-α-trypsin inhibitor light chain (ITI-LC), also known as bikunin or urinary trypsin inhibitor (UTI). In this study, therefore, immunoreactivities of mast cells of various human tissues were examined with three antibodies, anti-human ITI-LC, anti-ITI, which recognizes mainly heavy chains or the sugar moiety of ITI, and anti-α 1-microglobulin (α1mG). ITI-LC immunoreactivity was strongly found in mast cells in the connective tissues of various organs except for those of the propria mucosae of small intestine. Neither anti-ITI antibody nor anti-α1mG antibody reacted with mast cells in various tissues. By reverse transcription-polymerase chain reaction (RT-PCR) analysis, α1mG/ITI-LC mRNA was not detected in the skin and tongue, and only weakly in small intestine, although ITI-LC immunoreactivity was strongly detected in these tissues. Furthermore, the mRNA was not expressed in cultured human mast cells. These results suggest that ITI-LC protein is stored in the granules of human connective tissue mast cells, though is not produced by them.
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  • 12
    ISSN: 1432-0878
    Keywords: Key words Osteoblasts ; Extracellular matrix ; Transforming growth factor-β1 ; Basic fibroblast growth factor ; Apert’s syndrome ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The phenotype of Apert osteoblasts differs from that of normal osteoblasts in the accumulation of macromolecules in the extracellular matrix. Apert osteoblasts increase type I collagen, fibronectin and glycosaminoglycans secretion compared with normal osteoblasts. Because the extracellular matrix macromolecule accumulation is greatly modulated by transforming growth factor-β1, we examined the ability of normal and Apert osteoblasts to secrete transforming growth factor-β1 by CCL-64 assay and to produce transforming growth factor-β1 by analysis of the mRNA expression of transforming growth factor-β1. Northern blot analysis revealed an increased amount of transforming growth factor-β1 mRNA expression in Apert osteoblasts compared with normal ones. Moreover, the level of the active transforming growth factor-β1 isoform was higher in Apert than in normal media. In pathologic cells, the increase in transforming growth factor-β1 gene expression was associated with a parallel increase in the factor secreted into the medium. The level of transforming growth factor-β1 was decreased by the addition of basic fibroblast growth factor. Transforming growth factor-β1 is controlled temporally and spatially during skeletal tissue development and produces complex stimulatory and inhibitory changes in osteoblast functions. We hypothesise that in vitro differences between normal and Apert osteoblasts may be correlated to different transforming growth factor-β1 cascade patterns, probably due to an altered balance between transforming growth factor-β1 and basic fibroblast growth factor.
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  • 13
    ISSN: 1432-0878
    Keywords: Key words Endothelin ; Endothelin receptors ; Endothelin-converting enzyme ; Ovary ; In situ hybridization ; Human ; Cynomolgus monkey
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The endothelin system is composed of three endothelin isoforms (ET-1, ET-2, and ET-3), the endothelin receptors ETA and ETB, and the endothelin-converting enzyme (ECE). Besides having a major vasoactive role, endothelins have roles in different cell types at a local level. We investigated the presence of the different components of the endothelin system in primate ovaries. Human ovaries and gonadotropin-stimulated monkey ovaries were studied using immunohistochemistry for endothelin, and in situ hybridization with probes for ET-1, ET-2, ET-3, ETA and ETB receptors, and ECE. ET-1 and ETA receptors were detected in endothelial cells and vascular smooth muscle cells, respectively, in stromal vessels adjacent to follicles and corpora lutea. ETB receptors and ET-1 were found in the endothelial cells of capillaries of corpora lutea. ECE was present in internal theca cells of secondary, de Graaf, atretic follicles, and in luteinized granulosa cells of the corpora lutea. The endothelin system components are present in or around the follicles of human and monkey ovaries. Although the components are not expressed in the same cell types, they are synthesized, mainly in follicles, by cells that are in close proximity. Thus, the endothelin system could act in a paracrine manner. ECE expression in steroid-producing cells changes its compartmentalization during follicle maturation.
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  • 14
    Electronic Resource
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    Cell & tissue research 295 (1999), S. 297-305 
    ISSN: 1432-0878
    Keywords: Key words Trophoblast ; Macrophages ; Placenta ; Cell culture ; Paracrine regulation ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract In view of the accumulating evidence for paracrine mechanisms regulating trophoblast function, we tested the hypothesis that placental macrophages affect trophoblast activity in a paracrine fashion. Trophoblast was isolated from 17 term placentas (–IP). One aliquot of cells was further immunopurified (+IP) using an HLA class I antibody. This increased the proportion of trophoblast (+IP 〉97%; –IP ∼70%) as identified by rigorous immunocytochemistry. Most (∼70%) non-trophoblast cells in –IP were macrophages. The cells were cultured for 5 days with a daily medium change. In addition, +IP cells from seven placentas were cultured with lipopolysaccharide (LPS)-stimulated or -unstimulated macrophage-conditioned media. The concentrations of lactate, trophoblast-specific hormones, human chorionic gonadotropin-β (hCG-β) and human placental lactogen (hPL), of several prostanoids and of endothelin-1 and angiotensin II were determined in the culture media. The accumulated amounts of substances released into the culture media, corrected for the greater proportion of trophoblast in +IP cultures, were on average two- to threefold higher (hCG-β: 18-fold) in +IP than in –IP, with the exception of endothelin-1,2 (no change), angiotensin II (–70%) and 6-keto-prostaglandin-F1α (–40%). [3H]leucine incorporation into the trichloroacetic acid (TCA)-precipitable pool measured on day 5 was twofold higher in +IP than in –IP. Addition of conditioned media reverted these changes. The data demonstrate that placental macrophages in culture affect trophoblast biosynthetic activity in a paracrine fashion. We conclude that macrophages are important regulators of trophoblast activity.
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  • 15
    ISSN: 1432-0878
    Keywords: Key words Cerebrovascular development and injury ; Hemangioma ; Angiogenesis ; Immunocytochemistry ; Adhesion molecules ; Conventional transmission and high-voltage electron microscopy ; Mouse (C57BL ; SJL/J) ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Blood vessels from the vasculature of mouse brains during postnatal development and from human brain tumors (hemangiomas) removed at biopsy were examined immunocytochemically by transmission electron microscopy (TEM) or high-voltage transmission electron microscopy (HVEM) to determine the expression of intercellular adhesion molecule-1 (ICAM-1). In the mouse brains, ICAM-1 was shown to be initially expressed on the luminal and abluminal endothelial cell (EC) surfaces on day 3 after birth. ICAM-1 intensity increased on the luminal EC surfaces and labeled vesiculotubular profiles (VTS, defined in the present report) between days 5 and 7. After 2 weeks and at 6 months after birth, ICAM-1 labeling was weak or absent on the luminal EC surfaces. The hemangiomas presented a strong ICAM-1 reaction product on the luminal EC surfaces of small and large blood vessels associated with the VTS, with a weaker labeling of the abluminal or adventitial aspects of larger blood vessels. TEM of vesiculovacuolar structures (VVOs) within ECs from arteries and veins also demonstrated reaction product for ICAM-1 labeling. Three-dimensional stereo-pair images in the HVEM enhanced the visualization of gold particles that were attached to the inner-delimiting membrane surfaces of EC VTS, and VVOs, respectively. These observations raise the possibility that the neonatal leukocytes and tumor cells may utilize these endothelial structures as a route across the developing and injured blood-brain barrier (BBB).
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  • 16
    ISSN: 1432-0878
    Keywords: Key words Atherosclerosis ; Culture model ; Endothelial cell ; Endothelin-1 ; Oxidized LDL ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We investigated the structural and functional properties of human umbilical vein endothelial cells (HUVECs) cultured on a two-chamber culture model system using an amnion membrane. Compared to HUVECs cultured on a plastic dish, HUVECs cultured on the model system exhibited several features similar to those of in vivo vessels, including formation of the intercellular junctional devices and expression of tight junction-associated protein ZO-1 and adherence junction-associated protein α-catenin. Furthermore, we found that HUVECs had a property of polar secretion of endothelin-1 (ET-1). About 90% of the total amount of synthesized ET-1 was found in the lower well, designated as the basal side. When HUVECs were incubated with either native low-density lipoproteins (nLDLs) or oxidized LDLs (oxLDLs) at a concentration of 100 μg/ml, ET-1 secretion was significantly increased, dependent on the cell side (apical vs basal) on which the nLDLs or oxLDLs were loaded. When the LDLs were loaded on the apical side, the secretion of ET-1 from HUVECs on the apical side was increased by 48% (nLDL) and 61% (oxLDL), whereas it was accompanied by a concomitant decrease of ET-1 on the basal side (45% by nLDLs and 38% by oxLDLs). When loaded on the basal side, however, ET-1 was increased by 23% (nLDLs) and 53% (oxLDLs) on the basal side, with a 26% simultaneous decrease of ET-1 on the opposite side for both nLDLs and oxLDLs. On the contrary, high-density lipoproteins (HDLs) inhibited ET-1 secretion from HUVECs on the opposite side of the well on which HDLs were loaded; there was a 57% decrease on the basal side when HDLs were loaded on the apical side, and a 46% decrease on the apical side when loaded on the basal side. These results indicate that modulation of ET-1 secretion from ECs by lipoproteins is virtually dependent on the place (apical vs basal) where these proteins are present. The finding that nLDLs and oxLDLs enhance ET-1 secretion by ECs in a polarized pattern suggests that ET-1 may be involved in pathophysiological processes such as atherogenesis.
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  • 17
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    Cell & tissue research 295 (1999), S. 151-158 
    ISSN: 1432-0878
    Keywords: Key words Class II MHC-positive cells ; Human leukocyte antigen-DR ; Dental pulp ; Dendritic cells ; Macrophages ; Ultrastructure ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The distribution and ultrastructure of class II major histocompatibility complex (MHC)-positive cells were investigated in human dental pulp, employing immunohistochemistry using an anti-human leukocyte antigen (HLA)-DR-monoclonal antibody. HLA-DR-immunopositive cells, appearing spindle-like or dendritic in profile, were densely distributed throughout the dental pulp. Under the electron microscope, these cells exhibited various sizes of vesicles containing clear or opaque contents, multivesicular bodies and characteristic fine tubulovesicular structures in their cytoplasm. Some reactive cells possessed coated pits and vesicles including electron-dense materials, indicating an active endocytosis. At the periphery of the pulp tissue, the HLA-DR-immunopositive cells were predominantly situated in the subodontoblastic layer, with some located in the odontoblast layer and/or predentin and extending their cytoplasmic processes into the dentinal tubules. Cell processes of these cells occasionally made contact with several odontoblast processes in the same way as the nerve fibers in the predentin. These cells never contained the typical phagosomes frequently observed in the HLA-DR-immunoreactive macrophages in the subodontoblastic layer and the pulp core. The results suggest that the HLA-DR-immunopositive cells in the odontoblast layer and/or predentin have some regulatory function on the odontoblasts under physiological conditions, in addition to their involvement in the initial defense reaction after tooth injury.
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