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Results for “Functional differentiation”

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PubMed1980

[An immunohistochemical study of HCG and HPL on functional differentiation of human chorionic villi (author's transl)].

The enzyme-labeled antibody method was used to examine the localized distribution and variation by gestation week of HCG and HPL in placenta of 44 cases. 1) HCG: Electron microscopy revealed HRP reaction products in cisterna and membrane of perinuclear spaces and endoplasmic reticulum of syncytial cell (S-cell), but not in surface of S-cell microvilli or in Langhans' cell (L-cell). HRP reaction products in S-cell were more appreciable during 5th-12th weeks of gestation in syncytial sprouts, junction of villi with decidua, and rami or ramuli chorii, and fewer after 12th weeks. 2) HPL: Electron microscopy revealed reaction products in nuclear membrane and membrane of endoplasmic reticulum and Golgi complex, but not in surface of S-cell microvilli or L-cell. Reaction products in S-cell were noted from 8th gestation week, and most appreciably in 16th-18th gestation weeks preceding peak HPL concentration in serum. This indicates HPL exists in S-cell in the from of Pre. Pro-HPL.

Chorionic Gonadotropin↗
PubMed1977

Functional differentiation of B lymphocytes in congenital agammaglobulinemia. II. Immunochemical analysis of the in vitro primary immune response.

Cultures of peripheral blood lymphocytes (PBL) in which specific hemolytic plaque-forming cells (HcPFC) had been induced were labeled with 14C-amino acids. Antigen-specific products in the culture supernatants were characterized by using indirect immune precipitation in conjunction with specific immunoabsorbents and/or gel filtration followed by SDS-polyacrylamide gel electrophoresis. After 5 days of culture with antigen (sheep red blood cells or ovalbumin) newly synthesized IgM and specific IgM antibody were demonstrated in culture supernatants from normal donors and from four out of five patients with congenital agammaglobulinemia (cAgamma). Secreted products bound specifically to antigen and pretreatment of labeled supernatants with anti-mu and anti-L chain antisera, but not with anti-gamma antiserum, prevented binding. Typical mu- and L chains constituted only a proportion of the anigen-binding peptides recognized by the anti-mu reagents. Induction of IgM antibody synthesis was dependent on the presence of antigen and was correlated with the generation of HcPFC. No major differences between the antigen-induced products of cAgamma and normal PBL were observed. These findings suggest that in the absence of terminal B cell differentiation in vivo, certain patients with cAgamma possess precursor cells that can respond to antigen in vitro with the synthesis of specific humoral products, including IgM antibody.

Absorption↗
PubMed1995

Functional differentiation of adult neural circuits from a single embryonic network.

The stomatogastric nervous system (STNS) of adult lobsters and crabs generates a number of different rhythmic motor patterns which control different regional movements of the foregut. Since these output patterns are generated by discrete neural networks that, in the adult, are well characterized in terms of synaptic and cellular properties, this system constitutes an ideal model for exploring the mechanisms underlying the ontogeny of neural network organization. The foregut and its rhythmic motor patterns were studied in in vitro STNS nerve-muscle preparations of the embryo and different larval stages of the lobster Homarus gammarus. The development of Homarus comprises a long embryonic stage in ovo followed by three pelagic larval stages prior to the onset of benthic life. During these stages the foregut itself develops slowly from a simple ectodermal invagination that occurs in the embryo. During successive larval stages it progressively acquires all the specialized structures and shape of the adult foregut. In contrast, the STNS is morphologically recognizable at early embryonic stages. In all recorded stages the STNS spontaneously expresses rhythmic motor activity. During development, this activity is progressively restructured, beginning with a single rhythmic motor pattern in the embryo where all the stomodeal muscles are strongly coordinated. In subsequent stages, however, this single pattern is progressively subdivided to give rise eventually to the three discrete rhythmic motor patterns characteristic of the adult STNS. Our data suggest that rather than a dismantling of redundant embryonic and larval neural networks, the different adult networks emerge as a progressive partitioning of discrete circuits from a single embryonic network.

Animals↗
PubMed1994

Differential function of dendritic cells isolated from blood and lymph nodes.

Dendritic cells (DC) isolated from the lymph nodes or spleens of mice and pulsed with contact sensitizers or protein antigens stimulate primary proliferative responses by syngeneic T cells and responses to alloantigens in the mixed leucocyte reaction (MLR). Using enriched human peripheral blood DC, we attempted to stimulate primary immune responses to contact sensitizers by autologous lymphocytes in vitro. No significant proliferation above background levels or CD69 expression (an early activation antigen on lymphocytes) was detected despite using a wide range of donors, chemicals, antigens and cell concentrations. Culture of DC for up to 5 days in vitro in the presence of phytohaemagglutinin (PHA)-conditioned culture supernatants, or recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) also failed to induce primary proliferative responses to contact sensitizers. Comparisons were made between blood and lymph node DC from mice to explore whether the lack of stimulation was the result of differences between mouse and human DC or between DC isolated from different tissues. DC from lymph nodes stimulated primary responses to contact sensitizers in both blood and lymph node lymphocytes whereas blood DC did not stimulate responses. Both lymph node and blood DC stimulated an allogeneic MLR, although blood DC were less efficient than those from lymph node. The data show that DC from different tissues exhibit variable functional activity. DC from blood and lymph nodes were examined to determine whether surface antigen expression is related to functional activity. Murine blood DC expressed similar levels of LFA-1, LECAM-1 and CD44 compared with lymph node DC but lower levels of MHC class II, B7 and ICAM-1. These results may therefore have important implications for antigen processing and presentation in cells from different tissue compartments.

Allergens↗
PubMed1994

Differential functional activity of 5-hydroxytryptamine receptor ligands and beta adrenergic receptor antagonists at 5-hydroxytryptamine1B receptor sites in Chinese hamster lung fibroblasts and opossum renal epithelial cells.

Functional activity of 5-hydroxytryptamine (5-HT) receptor ligands and beta adrenergic receptor antagonists was studied at 5-HT1B receptor sites in Chinese hamster lung (CHL) fibroblasts by measuring two cellular responses: inhibition of forskolin-stimulated cyclic AMP formation and potentiation of basic fibroblast growth (BFGF) induced mitogenesis. A good correlation was found between the potency of agonists to inhibit forskolin-induced cyclic AMP formation and their potency to potentiate bFGF-induced thymidine incorporation in CHL fibroblasts. Potent agonist activity was measured with 5-methoxy-3,1,2,3,6-tetrahydro-4-pyidinyl- 1H-indole (RU 24,969), 5-carboxamidotryptamine (5-CT), 3-(1,2,5,6)-tetrahydro-4-pyridyl-5-pyrrolo(3,2-b)pyril-5-one (CP 93,129) and 5-HT, whereas sumatriptan displayed weak agonist activity at concentrations different from its binding affinity for 5-HT1B binding sites. In contrast to the observed 5-HT1B receptor-mediated agonist activity in opossum kidney cells for metergoline and the beta adrenergic receptor antagonists: cyanopindolol, 4-(3-tert-butyl-amino-2-hydroxypropoxy)-indole-2 carbonic acid isopropyl ester (SDZ 21,009), isamoltane, (-)-propranolol and (-)-pindolol, antagonist activity at 5-HT1B receptor sites was yielded in CHL fibroblasts in accordance with the reported observations at rat brain 5-HT1B receptors. Methiothepin was the only compound that antagonized both the opossum kidney cell and CHL fibroblast 5-HT1B receptor-mediated responses although the antagonist effect was more pronounced in CHL fibroblasts.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1976

Functional differentiation of the FSH-synthesizing cells in the pars distalis of the fetal pituitary gland of the rat.

The onset of FSH synthesis in the embryonic pituitary gland of the rat was studied by a peroxidase-labelled antibody method. The first FSH-containing cells appeared on the 20th day of embryonic life. From that day onwards, FSH cells increased rapidly in number. It was found that in adult animals some pituitary cells reacted with both anti-HCG and anti-FSH sera, indicating the simultaneous presence of LH and FSH in the same cell.

Animals↗
PubMed1979

Role of surface IgM and IgD in the functional differentiation of human B lymphocytes: effect of papain treatment.

Short-term treatment of normal human B lymphocytes with low concentrations of papain resulted in selective and reversible removal of sIgD determinants, whereas HLA and Ia-like antigens, sIgM as well as receptors for E, C3, and FcIgG were unaffected. When studied for their capacity to generate antigen-specific direct PFC, papain-treated (delta-) B cells were highly sensitive to inactivation by even low concentrations of antigen. In addition, these cells were impaired in their ability to cooperate normally with T-helper cells or their humoral product(s).

B-Lymphocytes↗
PubMed1979

Functional differentiation of T cell precursors. I. Parameters of carrier-specific tolerance in murine helper T cell precursors.

Irradiated mice reconstituted with bone marrow from sheep gamma-globulin- (SGG) tolerant syngeneic donors display reduced IgG responsiveness to challenge with trinitrophenylated (TNP)-SGG compared with recipients of normal marrow. This effect is SGG-specific and is due neither to suppressor T cells nor to antigen carryover. "Helper T cell precursor tolerance" can be induced with as little as 40 micrograms tolerogen (SGG). Unlike mature helper T cells, these precursors show both a rapid induction and rapid waning patterns, suggesting a high rate of turnover. Our results imply that marrow helper T cell precursors bear antigen-specific receptors and that the T cell repertoire must be at least partially generated before residence in the thymus.

Animals↗
PubMed1997

[Effects of functional differentiation within home care on the quality of care--from the client's viewpoint].

In home care nursing work is redesigned by differentiated practice (= skill mix) and specialization. The aim of this redesign is efficient use of staff, and maintenance or improvement of quality of care. In this article the effects of differentiated practice and specialization are studied in respect of quality of care. The perspective of the client was taken as the starting point. Quality of care was defined as the discrepancy between clients' expectations and perceptions of several aspects of care. The effects of work redesign were determined on the basis of a comparison between an experimental (n = 103) and a control group (n = 108). Data-analysis showed hardly any differences. Possible explanations are the premature status of the projects and the fact that clients are usually (very) satisfied. The margin in which differences between the experimental and the control group should occur is therefore very small. However, by means of this approach a detailed picture can be obtained of the subjective standard clients use to judge the quality of care.

Aged↗
PubMed1992

Expression of growth hormone receptor by immunocytochemistry in rat molar root formation and alveolar bone remodeling.

Growth hormone (GH) may regulate tooth formation and bone remodeling associated with tooth eruption. This study reports the distribution of growth hormone receptor/binding protein in developing rat molars and adjacent alveolar bone by immunocytochemistry using well-characterized anti-growth hormone receptor monoclonal antibodies. These tissues represent an excellent model for studying the ontogenic changes that occur in odontogenic and osteogenic cells, as these cells are found in linear arrays displaying the various stages of morphological and functional differentiation, and differentiated function. Immunoreactivity was first seen in precementoblasts in contact with the epithelial root sheath, and preodontoblasts. However, growth hormone receptor immunoreactivity was associated primarily with the cytoplasm of odontogenic and osteogenic cells forming their respective matrices. Thus, cementoblasts and odontoblasts at sites of new matrix formation showed intense immunoreactivity whereas cementocytes and mature odontoblasts at later stages of tooth development were nonreactive. Osteoblasts engaged in intramembranous ossification in the alveolar bone were positive, although osteocytes and endosteal cells were immunonegative. Osteoclasts at sites of alveolar bone remodeling resorption were also immunopositive. These patterns of receptor expression parallel the ontogenic sequences of odontogenic and osteogenic cells and suggest that GH promotes the functional state of these cells. Our results also imply that GH may influence differentiation or differentiated functions associated with odontogenesis, osteogenesis, and bone remodeling independent of systemic insulin-like GF-I.

Alveolar Process↗
PubMed2006

[Bone and bone related biochemical examinations. Bone and collagen related metabolites. Regulatory mechanisms of osteoclast differentiation and function].

Osteoclast differentiation is tightly regulated by osteoblasts. Osteoblasts express two cytokines, macrophage colony-stimulating factor (M-CSF) and receptor activator of NF-kappaB ligand (RANKL), essential for osteoclast differentiation. Osteoclast precursors firstly differentiate into mononuclear osteoclasts in response to M-CSF and RANKL. Nuclear factor of activated T cells 1 (NFATc1) is a transcription factor, which is involved in the determination of osteoclast differentiation. The mononuclear osteoclast then fuses each other to form the multinucleated cell. Dendritic cell-specific transmembrane protein (DC-STAMP) plays an important role in the fusion of mononuclear osteoclasts. Osteoclasts recognize bone and form ruffled borders and clear zones on the bone surface (polarization). Polarizing osteoclasts construct active vascular transportation systems to resorb bone efficiently. RANK-TRAF6 (TNF receptor-associated factor 6) -mediated signals key roles in both osteoclast differentiation and function. In this article, I will review the recent findings on osteoclast differentiation and function.

Animals↗
PubMed1999

Osteoclast differentiation factor acts as a multifunctional regulator in murine osteoclast differentiation and function.

Osteoclast differentiation factor (ODF), a novel member of the TNF ligand family, is expressed as a membrane-associated protein by osteoblasts/stromal cells. The soluble form of ODF (sODF) induces the differentiation of osteoclast precursors into osteoclasts in the presence of M-CSF. Here, the effects of sODF on the survival, multinucleation, and pit-forming activity of murine osteoclasts were examined in comparison with those of M-CSF and IL-1. Osteoclast-like cells (OCLs) formed in cocultures of murine osteoblasts and bone marrow cells expressed mRNA of RANK (receptor activator of NF-kappaB), a receptor of ODF. The survival of OCLs was enhanced by the addition of each of sODF, M-CSF, and IL-1. sODF, as well as IL-1, activated NF-kappaB and c-Jun N-terminal protein kinase (JNK) in OCLs. Like M-CSF and IL-1, sODF stimulated the survival and multinucleation of prefusion osteoclasts (pOCs) isolated from the coculture. When pOCs were cultured on dentine slices, resorption pits were formed on the slices in the presence of either sODF or IL-1 but not in that of M-CSF. A soluble form of RANK as well as osteoprotegerin/osteoclastogenesis inhibitory factor, a decoy receptor of ODF, blocked OCL formation and prevented the survival, multinucleation, and pit-forming activity of pOCs induced by sODF. These results suggest that ODF regulates not only osteoclast differentiation but also osteoclast function in mice through the receptor RANK.

Acid Phosphatase↗
PubMed1987

Induction of cytotoxic capacity by recombinant gamma interferon in human myelomonocytic leukaemia cell lines.

We have investigated the ability of human recombinant gamma interferon (IFN-gamma) to induce functional differentiation in three human myelomonocytic cell lines U937, RC2A, and ML-2. Treatment with IFN-gamma induced natural killer (NK) cell like cytotoxicity against K-562 cells in ML-2 and RC2A but not in U937. U937 and RC2A displayed a spontaneous antibody-dependent cell-mediated cytotoxicity (ADCC), which against nucleated target cells was significantly increased in U937 but not in RC2A after treatment with IFN-gamma. ML-2 did not display ADCC against nucleated targets either before or after IFN-gamma treatment, but lysed efficiently antibody-coated erythrocytes. All three cell lines displayed enhanced ADCC against erythrocytes after IFN-gamma treatment. Spontaneous phagocytosis of erythrocytes was seen in U937, and this was enhanced by IFN-gamma treatment, while ML-2 and RC2A were phagocytically inactive before and after treatment with IFN-gamma. The differentiated functions induced by IFN-gamma treatment in this panel of phenotypically closely related cell lines offers an interesting model for further studies on the IFN-gamma regulated gene expression. Moreover, the increased cytolytic capacity after exposure to IFN-gamma might have implications on the use of IFN-gamma for treatment of myelomonocytic malignancies. In such cases, IFN-gamma might even increase the aggressiveness of the tumour.

Antibody-Dependent Cell Cytotoxicity↗