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991.
A rapid, sensitive method has been developed to detect antibody-antigen complexes on “Western blots.” The methods of H. Towbin, T. Staehlin, and J. Gordon were used to separate and blot the antigens onto nitrocellulose. The remaining sites of attachment were blocked and the nitrocellulose was washed with polyoxyethylenesorbitan monolaurate (Tween 20). The blot was then reacted with the antiserum or hybridoma supernate to be tested. After the antigen-antibody reaction was completed, the blot was washed and treated with anti-antibody which has been conjugated to alkaline phosphatase. The alkaline phosphatase was detected by the reduction of the tetrazolium salt to diformazan by the hydrogen ions released in the formation of indigo by the reaction of the phosphatase on the indoxyl phosphate. The advantages of this method over previously described techniques are (1) use of Tween 20 allows the blot to be stained with Coomassie blue, (2) the substrates of the alkaline phosphatase reaction are stable for long periods of time, (3) the reaction products form an intense blue color which does not fade, (4) the resolution is extremely good with little to no band broadening, (5) the reaction is sensitive to picogram quantities of antigen, and (6) the reaction is quantitative.  相似文献   
992.
993.
994.
Fractions containing macrophage migration inhibition factor (MIF) and leucocyte migration inhibition factor (LIF) were obtained using Sephadex G-200 filtration from supernatant fluids of human lymphocyte cultures stimulated by PHA. The fractions were tested for the ability to affect migration and phagocytic activity of target cells. Peripheral blood leucocyte migration capacity was inhibited by the fraction with the molecular mass of 60,000-70,000 D (LIF), while migration activity of mouse peritoneal exudate cells was suppressed by the fraction with the molecular mass of 20,000-30,000 D (MIF). MIF- and LIF-containing fractions increased almost three-fold Fc-receptor-mediated phagocytic activity of neutrophils.  相似文献   
995.
Several phenotypic and functional defects have been described within the residual T-lymphocyte population of patients with B-cell chronic lymphocytic leukemia (B-CLL), particularly in those in the more advanced stages of the disease. In this study, we review these abnormalities and discuss their possible effects on the course of the illness. Particular emphasis is devoted to the role of interleukin 2 (IL-2) in B-CLL. Evidence is provided that the IL-2 released by B-CLL T-lymphocytes may be utilized by the neoplastic B-cell clone that expresses the IL-2 receptor and that decreased availability of IL-2 may play a contributory role in some of the T-cell defects encountered in B-CLL.  相似文献   
996.
The isolation of spirochaetes from the rat caecum   总被引:1,自引:1,他引:0  
Spirochaetes indigenous to the conventional rat caecum were cultivated on agar medium using selective isolation techniques. The 27 axenic isolates represented four morphological types of spirochaetes differing in cell size, cell coiling pattern and number of protoplasmic flagella.  相似文献   
997.
Plasma concentrations of adrenaline and noradrenaline were measured at rest from cannulated fish and following net capture. Adrenaline and noradrenaline concentrations in capture-stressed fish averaged 36,740 pmol l-1 and 38,860 pmol l-1 respectively, whereas resting values were less than 200 pmol l-1 for both amines. Erythrocyte swelling and raised blood lactate were evident in stressed fish. In vitro effects of 5 mmol l-1 adrenaline on erythrocyte suspensions suggested that the catecholamine had a direct effect on erythrocyte volume. The significance of these results is discussed in relation to the oxygen transport properties of the blood.  相似文献   
998.
Antigen inoculated intratracheally (IT) into animals can induce primary immune responses and selectively recruit specific T cells to the lung. In the current study, the role of alveolar macrophages (AM) in these two responses was investigated. Antigen-pulsed bronchoalveolar cells (BAC) inoculated IT into guinea pigs generated a population of immune T cells that proliferated in vitro on reexposure to antigen-pulsed macrophages (M?). The possibility that antigen-pulsed donor BAC shed antigen that was subsequently processed and presented by host M? was ruled out by genetic experiments. Thus, peritoneal exudate lymphocytes (PEL) from (2 X 13)F1 guinea pigs primed with antigen-pulsed BAC from strain 2 animals responded preferentially to antigen-pulsed strain 2 M? rather than to antigen-pulsed strain 13 M?. In a second set of studies, antigen-pulsed BAC inoculated IT into guinea pigs selectively recruited antigen-specific T cells to the lung. Genetic experiments verified that inoculated BAC were the source of the antigen-presenting cells responsible for selective recruitment. Thus, antigen-pulsed strain 2 BAC inoculated IT recruited a greater proportion of (2 X 13)F1 T cells that recognized antigen in the context of strain 2 M? than F1 T cells that recognized antigen on strain 13 M?. Taken together, these studies suggest that AM contribute to the regulation of pulmonary immunity by both inducing T lymphocyte immunity and selectively recruiting specific T cells to the lung.  相似文献   
999.
Studies on larval population densities and adult emergence rates of the Brugian filariasis vectors Mansonia bonneae Edwards and Ma. dives Schiner were conducted in freshwater swamp forest bordering the Sadong River, Serian District, Sarawak, East Malaysia, during 1984-85. Three species of aquatic host-plants in the Family Araceae were identified as supporting immature stages of the Ma. bonneae/dives complex. Proportions of positive plants were 4.7%, 6.5% and 3.4% with 6.4 +/- 2.6, 7.3 +/- 2.8 and 10.1 +/- 1.1 larvae per positive plant, respectively, for the plant species Homalomena cordata Schott, H. rostrata Griffiths and Hydrostemma motleyi (Hook. f.) Mabberley. These data indicate no significant preferences between the three types of host-plant. Detailed monitoring of the host-plant H. cordata revealed no significant monthly fluctuations in larval density per plant nor the proportion of positive plants. 11.6% of larvae were Ma. dives and 88.4% were Ma. bonneae. Mean daily yields of Ma. bonneae/dives adults per square metre of H. cordata vegetated water surface were 0.45 males plus 0.57 females during the wet season (December-February) compared with 0.2 males plus 0.31 females during the dry season (June-August). Thus output of adults per plant was approximately halved, and suitable breeding areas were further reduced, during the dry season. By extrapolation from these rates, a crude mean estimate for productivity of Ma. bonneae/dives females is 1.6 million per hectare per annum in swamp forest habitats vegetated with any of the host-plants studied.  相似文献   
1000.
MATING FREQUENCY AND FECUNDITY IN INSECTS   总被引:8,自引:0,他引:8  
1. The paper summarizes the published evidence on the relation between mating frequency and fecundity in insects. There is experimental evidence of varying quality for 63 species and non-experimental evidence for about 60.
2. Repeated mating may be universally necessary for full fecundity and fertility in female insects (in species in which the females normally mate more than once).
3. The evidence is remarkably poor. We need more properly designed experiments (and not just observations of natural variation), with sufficient sample sizes and statistics, and measurements of the fecundities and fertilities of singly and multiply mated females, when the multiple matings are separated by many days or weeks. Most of the existing experiments of this sort are defective in some way.
4. In species with greater total fecundity and longevity, multiple mating may be more likely to enhance fertility than in species with small fecundity and short life span.
5. Females in naturally monandrous species do not show increased fecundity or fertility with repeated mating, whereas females of polyandrous species do.
6. There is no obvious connexion between paternal investment, in so far as we know about it, and the increase of fecundity by repeated mating.
7. There is a small tendency for females to breed more quickly and be shorter lived if they mate repeatedly.  相似文献   
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