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621.
622.
The four colony-stimulating factors, GM-GSF, G-CSF, M-CSF and Multi-CSF, are specific glycoproteins with a likely common ancestral origin which interact to regulate the production, maturation and function of granulocytes and monocyte-macrophages. Each has been purified and produced in active recombinant form. Animal studies have shown the ability of injected CSF to increase the production and functional activity of granulocytes and macrophages in vivo and to enhance resistance to infections. These studies have led to the current extensive clinical use of CSFs to promote the formation and function of granulocytes and macrophages in a wide variety of disease situations in which there is an associated risk of serious infections. Although our knowledge of the control of haemopoiesis remains incomplete, the approaches used to develop the CSFs can be used to extend this knowledge, with the promise of the introduction into clinical medicine of additional effective therapeutic agents.  相似文献   
623.
A rapid and sensitive method for the concurrent assay of 25 ng noradrenaline, dopaine or 5HT is presented, enabling the concentration of all three amines to be measured in a single small sample (20–40 mg) of brain tissue. The method has been applied to determine the concentration of these amines in different regions of rabbit brain.  相似文献   
624.
The effect of sodium nitrite, amyl nitrite and nitroglycerin (glyceryl trinitrate) on the hemoglobin of adult erythrocytes was examined in vitro. Both amyl nitrite and nitroglycerin reacted immediately with oxyhemoglobin to effect oxidation into methemoglobin while sodium nitrite required an inductionary period (lag phase) prior to the reaction. Kinetic studies of the biomolecular rate law for each of the preceding reaction's reactionary periods (log phases) allowed rate constant calculations to be made. The values are 1.14 x 10(4) M-1 min-1, 7.45 x 10(4) M-1 min-1, and 3.50 x 10(1) M-1 min-1 for sodium nitrite, amyl nitrite and nitroglycerin, respectively. A comparison of the amyl nitrite and nitroglycerin rate constants reveals that amyl nitrite is approximately 2000-fold more toxic to oxyhemoglobin than nitroglycerin. These oxidant's effect on in vitro hemoglobin solutions are comparable since both reactions approximate to rectangular hyperbolae. Sodium nitrite reacts about 300-fold faster with oxyhemoglobin than does nitroglycerin. However, the sodium nitrite reaction proceeds in a sigmoidal fashion which makes a strict comparison between these compounds relative toxicities less clear cut.  相似文献   
625.
The proper development of the organs of the immune system is dependent on at least three factors: (1) the development of anlagen with the capacity to trap antigens and support the proliferation of lymphoid and plasma cell precursors; (2) the production by the bone marrow of lymphoid and plasma cell precursors which seed in the lymphoid organs; and (3) the thymus, which seeds reactive cells to the lymphoid organs and produces a humoral factor stimulating antigen-triggered proliferation of primitive lymphoid and plasma cells. Studies on cell population changes in the lymph nodes following thymectomy in mice confirm earlier evidence that most cells produced in the thymus do not seed to the lymphoid organs, but die locally in the thymus.  相似文献   
626.
627.
The CSF's extracted from 6-hour “in vivo” post-endotoxin mouse lung tissue and 48-hour “in vitro” lung-conditioned medium appear to be glyco-proteins, for like human urinary CSF they were inactivated by proteases and altered in charge but not inactivated by sialidase. Neither endotoxin injection nor length of in vitro incubation significantly affected the apparent S20 W (approximately 2.OS) of the bulk of the CSF in mouse lung-conditioned medium. The lower apparent molecular weight of CSF in mouse lung-conditioned medium contrasted with that of monkey lung-conditioned medium (S20 W approximately 3.3S). CSF's in both monkey and mouse lung-conditioned media exhibited a much higher apparent MW on gel nitration than one would expect from their sedimentation behavior, a characteristic generally observed with most unpurified CSF preparations. Mouse lung-conditioned medium CSF was antigenically distinguishable from other CSF's. Failure to demonstrate this form of CSF in the tissue serum or urine of normal or endotoxin-injected mice suggests that this type of CSF might normally lack in vivo significance.  相似文献   
628.
629.
Colonies of elongated fibroblast-like cells (stellate colonies) developed in agar cultures of mouse pleural cavity cells mixed with whole blood. Cultures of pleural cells alone developed only abortive clusters of round cells. The frequency of colony-forming cells in the pleural cavity was highest in neonatal mice (200/105 cells) and fell progressively with aging. Stellate colony-forming cells were not in cell cycle but were radiosensitive. In adult mice, only occasional colony-forming cells were detected in peritoneal cavity, thymic, spleen, lymph node or bone marrow cell populations. Stellate colony formation was not stimulated by the granulopoietic regulator, colony stimulating factor. The active component in whole blood required for stellate colony formation was present in plasma but not serum or washed red or white cells.  相似文献   
630.
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