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991.
Nicola Tannenbaum 《American anthropologist》1984,86(4):927-942
Sahlins's "Chayanov's Rule"–the more consumers each worker has to support the more work each worker does-has characterized Chayanov's analysis for most anthropologists. I examine the relationship between the consumer/worker ratio and product per worker for the Shan community of Thongmakhsan in northwestern Thailand. Since there is no systematic relationship between these variables even when the population is divided into production strategy groups, I go on to examine the relationship between Sahlins's "Chayanov's Rule" and Chayanov's own analysis. In conclusion I raise the issue of the continuing identification of Chayanov with "Chayanov's Rule" and consider a number of possible reasons for this. 相似文献
992.
Activation of granulocyte cytotoxic function by purified mouse colony-stimulating factors 总被引:15,自引:0,他引:15
A F Lopez N A Nicola A W Burgess D Metcalf F L Battye W A Sewell M Vadas 《Journal of immunology (Baltimore, Md. : 1950)》1983,131(6):2983-2988
Highly purified mouse colony-stimulating factors (CSF) were tested for their effect on neutrophil cytotoxic function in a homologous antibody-dependent cell-mediated cytotoxicity (ADCC) assay in which TNP-coupled mouse thymoma cells coated with mouse anti-TNP antibodies were used as targets, and purified normal mouse bone marrow neutrophils or induced peritoneal neutrophils were used as effector cells. Biochemically pure granulocyte-macrophage (GM)- and granulocyte (G)-CSF enhanced the cytotoxic activity of neutrophils obtained from both sources, allowing them to kill target cells at low antibody concentrations. Furthermore, GM- and G-CSF showed an additive effect, suggesting either the presence of separate receptors for GM- and G-CSF or of separate subsets of neutrophils. Induced peritoneal neutrophils showed a higher level of basal cytotoxic activity than did bone marrow neutrophils, suggesting neutrophil activation in vivo, but both reached similar levels of cytotoxicity upon maximal stimulation with CSF. In addition, CSF was found to be cross-reactive between mouse and human species in their enhancement of neutrophil cytotoxicity. By testing purified mouse CSF on human neutrophils, it could be shown that G-CSF and GM-CSF are functionally distinct molecules, because only G-CSF enhanced ADCC by human neutrophils. These experiments show that the purified factors that control the production of neutrophils by progenitor cells in vitro also activate differentiated neutrophils to carry out their cytotoxic activity in a more effective manner. 相似文献
993.
Marcella Maddaluno Gianluca Grassia Maria Vittoria Di Lauro Antonio Parisi Francesco Maione Carla Cicala Daniele De Filippis Teresa Iuvone Angelo Guglielmotti Pasquale Maffia Nicola Mascolo Armando Ialenti 《PloS one》2012,7(10)
Bindarit, a selective inhibitor of monocyte chemotactic proteins (MCPs) synthesis, reduces neointimal formation in animal models of vascular injury and recently has been shown to inhibit in-stent late loss in a placebo-controlled phase II clinical trial. However, the mechanisms underlying the efficacy of bindarit in controlling neointimal formation/restenosis have not been fully elucidated. Therefore, we investigated the effect of bindarit on human coronary smooth muscle cells activation, drawing attention to the phenotypic modulation process, focusing on contractile proteins expression as well as proliferation and migration. The expression of contractile proteins was evaluated by western blot analysis on cultured human coronary smooth muscle cells stimulated with TNF-α (30 ng/mL) or fetal bovine serum (5%). Bindarit (100–300 µM) reduced the embryonic form of smooth muscle myosin heavy chain while increased smooth muscle α-actin and calponin in both TNF-α- and fetal bovine serum-stimulated cells. These effects were associated with the inhibition of human coronary smooth muscle cell proliferation/migration and both MCP-1 and MCP-3 production. The effect of bindarit on smooth muscle cells phenotypic switching was confirmed in vivo in the rat balloon angioplasty model. Bindarit (200 mg/Kg/day) significantly reduced the expression of the embryonic form of smooth muscle myosin heavy chain, and increased smooth muscle α-actin and calponin in the rat carodid arteries subjected to endothelial denudation. Our results demonstrate that bindarit induces the differentiated state of human coronary smooth muscle cells, suggesting a novel underlying mechanisms by which this drug inhibits neointimal formation. 相似文献
994.
995.
996.
C Grillo S M Vallee G Piroli B S McEwen A F De Nicola 《The Journal of steroid biochemistry and molecular biology》1992,42(5):515-520
Type I corticosteroid receptors were determined in cytosol from hippocampus (HIPPO) and amygdala (AMYG), using [3H]aldosterone (ALDO), [3H]dexamethasone (DEX) or the mineralocorticoid antagonist [3H]ZK 91587 as ligands. Incubations with the first two compounds also contained the pure glucocorticoid RU 28362 to block type II receptors. Binding of the three ligands was comparable in cytosol from HIPPO and it was slightly higher for [3H]DEX in AMYG. However, after heat-induced receptor transformation, binding to DNA-cellulose was observed for [3H]ALDO-receptor complex obtained from HIPPO or AMYG, whereas it was negligible for [3H]ZK 91587. Receptors charged with [3H]DEX or [3H]ALDO showed similar retention on DNA-cellulose columns in the case of the AMYG, while binding to the polynucleotide was higher for [3H]ALDO in the HIPPO. Finally, only [3H]ALDO was taken up to a significant extent in purified cell nuclei prepared from slices of HIPPO and AMYG previously incubated with the three ligands. It is concluded that binding of a natural agonist steroid may be a prerequisite for type I receptor transformation and translocation from the cytoplasm into the nuclear fraction. DEX binding to type I receptors resembles a partial agonist with antagonist properties, whereas antagonists such as ZK 91587 are bound and retained in cytoplasm, without further translocation. 相似文献
997.
Light stimulates the betaxanthin accumulation in Celosia plumosa. The induction is partially reversed by far-red and inhibited by actinomycin D, puromycin, salicylaldoxime and 2,4-dinitrophenol, while 3-(3,4-dichlorophenyl)-1,1-dimethylurea has an inhibitory effect only when photosynthesis is operative. In darkness betaxanthins synthesis is promoted by kinetin. 相似文献
998.
Pietro Dri Barbara Bisiacchi Rita Cramer Paolo Bellavite Giuseppina de Nicola Pierluigi Patriarca 《Molecular and cellular biochemistry》1978,22(2-3):159-166
Summary The oxidative response to phagocytosis by chicken polymorphonuclear leucocytes was investigated as compared to guinea pig polymorphonuclear leucocytes.The polymorphs from both species respond to phagocytosis with an increased oxygen consumption, an increased generation of O2
– and H2O2, and an increased oxidation of glucose through the hexose monophosphate shunt. The rate of oxygen consumption, and generation of O2
– and H2O2 by phagocytosing chicken polymorphonuclear leucocytes is considerably lower than with phagocytosing guinea pig polymorphonuclear leucocytes. By contrast, the extent of hexose monophosphate shunt stimulation in chicken polymorphs is comparable to that of guinea pig polymorphs. Evidence is presented suggesting that H2O2 is preferentially degraded in chicken cells through the glutathione cycle, whereas catalase and myeloperoxidase are the two main H2O2 degrading enzymes in guinea pig cells.The 20,000 g fraction of the postnuclear supernatant of chicken polymorphs contains a cyanide-insensitive NADPH oxidizing activity which is stimulated during phagocytosis. Similar properties for the NADPH oxidizing activity of guinea pig polymorphs have been previously reported.It is concluded that the metabolic burst of phagocytosing chicken polymorphonuclear leucocytes is qualitatively similar to that of guinea pig polymorphonuclear leucocytes, but the latter cells are more active in all the biochemical parameters that have been measured. The difference in the H2O2 degradation pathways between the two species is accounted for by the lack of myeloperoxidase and catalase in chicken polymorphs. 相似文献
999.
The effect of inhibiting adenosine-metabolizing enzymes on sperm fertilizing ability was studied to investigate a possible role for endogenously generated adenosine in the regulation of capacitation. The compounds used have been shown to be effective inhibitors of the relevant enzymes in similarly incubated mouse sperm suspensions. Inhibition of 5′-nucleotidase activity with α,β-methylene adenosine 5′-diphosphate (AMPCP), to reduce available endogenous adenosine, caused a dose-dependent inhibition of the fertilizing ability of partially capacitated spermatozoa, which was significant with 100 and 250 μM AMPCP. Conversely, inhibition of adenosine deaminase with 100 nM coformycin, to increase available endogenous adenosine, promoted the fertilizing ability of partially capacitated spermatozoa when the fertilization rate of control suspensions was low. However, coformycin had no effect on sperm suspensions with moderate fertilizing ability, and it inhibited fertilizing ability when added to capacitated spermatozoa. These data are consistent with a promotion of the early stages of capacitation by endogenously generated adenosine and suggest that sensitivity to adenosine changes as capacitation proceeds. Because the majority of adenosine-metabolizing enzyme activity resides in or is directed toward the extracellular compartment in such suspensions, these effects of adenosine may be mediated at the outer surface of the cell. By interacting with receptors on adenylate cyclase, externally produced adenosine could modulate intracellular levels of cyclic adenosine monophosphate (cAMP), thereby influencing fertilizing ability. 相似文献
1000.
Kokkonen Nicola Laine Anna M. Männistö Elisa Mehtätalo Lauri Korrensalo Aino Tuittila Eeva-Stiina 《Ecosystems》2022,25(7):1601-1618
Ecosystems - Climate change and the related increases in evapotranspiration threaten to make northern peatlands drier. The carbon sink function in peatlands is based on the delicate balance between... 相似文献