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81.
82.
The roles of honey bee queen mandibular pheromone and colony congestion in the inhibition of swarming were investigated. Two colony siz.es were used: small, congested colonies and large, uncongested colonies. Both groups of colonies were treated with various dosages of the five-component, synthetic queen mandibular pheromone in the spring, and the extent and timing of swarming were followed. Most treatment groups received pheromone or a solvent blank (control) on a stationary slide; one group of the congested colonies received a pheromone treatment via an aerosol spray. The pheromone was not effective at delaying swarming in the congested colonies at any dosage applied on slides, but the aerosol spray-treated colonies swarmed significantly later in the season than the control colonies. The uncongested, pheromone-treated colonies exhibited a dose-dependent delay in swarming, with the highest dosage colonies swarming almost four weeks later than the control colonies. These results indicate an interaction between congestion and pheromone in the control of honey bee reproduction. While congestion may in itself be a factor stimulating swarming, these results are consistent with the interpretation that colony congestion reduces the transmission of queen pheromone within the nest, thereby removing the queen 's pheromone-based inhibition of queen rearing and subsequent swarming by workers.  相似文献   
83.
84.
Pooled sera from CBA/J mice infected for greater than or equal to 16 weeks with the blood fluke Schistosoma mansoni were immunoaffinity purified using soluble schistosome egg antigens (SEA) coupled to Sepharose 4B. The bound and then eluted fraction was shown to contain only immunoglobulins and to have anti-SEA activity. These anti-SEA antibodies stimulated proliferation of lymph node cells from mice infected with S. mansoni for 8, 12, or greater than or equal to 16 weeks but not from uninfected mice. The cells stimulated by anti-SEA antibodies were nylon wool adherent, Thy-1.2+, L3T4+, Lyt-2-lymphocytes. Immunoglobulins without anti-SEA activity isolated from the sera of syngeneic uninfected mice were not stimulatory for cells from normal or infected animals. Thus the responding T cells appear to be stimulated by the idiotypes expressed on the syngenic anti-SEA antibodies. These data present evidence for anti-idiotypic cellular reactions in murine schistosomiasis that could play important immunoregulatory roles in this disease.  相似文献   
85.
Mice exposed to 35 cercariae of the human helminth Schistosoma mansoni develop chronic (greater than 16wk) infections characterized by immunoregulation of their cell-mediated granulomatous responses to schistosome eggs. Evidence was sought regarding the possible development of anti-idiotypic responses against the responses to soluble egg antigens (SEA). Sera were collected from CBA/J mice with chronic S. mansoni infections. Multiclonal idiotypic, anti-SEA antibody (id) was prepared from these pooled sera by affinity chromatography on an SEA immunoadsorbent column. Analysis of the id preparations by polyacrylamide gel electrophoresis demonstrated that this material contained only immunoglobulin heavy and light chains. A modified reverse plaque-forming cell (PFC) assay was developed to quantify anti-idiotypic (anti-id) PFC in spleen cell preparations from infected and age-matched control CBA/J mice. Expression of anti-id PFC began 2 to 3 wk after onset of egg production and continued throughout the course of infection. Positive selection of anti-id-reactive spleen cells by panning cell preparations from chronic mice on id-coated plates resulted in an enrichment of anti-id PFC in the id-adherent population. Conversely, the number of PFC reactive with SEA (id-producing PFC) was lowered by panning on id-coated plates. These data demonstrate the occurrence of anti-id responses during schistosomiasis mansoni. It is possible that such an immunoregulatory mechanism could play an important role in how an animal modulates the granulomatous response that leads to the formation of pathologic lesions and in the maintenance of this chronic infection.  相似文献   
86.
Summary Within 24 h after the initial phagocytotic uptake of freshly isolated (from host tissue) symbiotic algae (Symbiodinium microadriaticum) by the endodermal cells of the polyp (scyphistoma) stage of the jellyfish Cassiopeia xamachana, the algal population was observed to decline despite evidence of algal cell division. Analyses of the frequency of phago-lysosome fusion as an indicator of possible attempts of the host to digest the algae indicated that, although phago-lysosome fusion did occur, the low frequency of occurrence is inconsistent with the interpretation that the animals digested the algae. Animal cell lysosomes were located predominantly at the apices of the endodermal cells, and the symbiotic algae were transported toward the bases of the endodermal cells.Within 3 days after initial infection, most endodermal cells with algae ceased to be phagocytotically active (with respect to the uptake of carmine particles). Many of these endodermal cells soon migrated into the mesoglea to become what are traditionally referred to as amoebocytes. Within amoebocytes the algae proliferated. The onset of strobilation by the scyphistomae was directly correlated with the increase in the algal population within these amoebocytes.  相似文献   
87.
A program has been written to run on a pocket computer (Sharp PC-1500) that can be used at the bedside to predict the nutritional requirements of patients with a wide range of clinical conditions. The predictions of the program showed good correlation with measured values for energy and nitrogen requirements. The program was used, with good results, in the management of over 100 patients needing nutritional support. The calculation of nutritional requirements for each patient individually facilitates more appropriate treatment and may also produce financial savings when compared with administration of a standard feeding regimen to all patients.  相似文献   
88.
Egg-induced granulomas formed in mice with chronic Schistosoma mansoni infection are smaller than those which develop during early (8-week) infection. Adoptive transfer of spleen cells from chronically infected mice (15–25 week), which displayed modulated granulomas, to 6-week-infected recipients effectively suppressed active granuloma formation in the recipients by 8 weeks after infection. Pretreatment of these suppressive spleen cells with anti-Thy 1.2 serum and complement eliminated their suppressive capacity. Administration of cyclophosphamide (CY) (20 mg/kg, 3 times/week for 3 weeks) to 12- to 15-week-infected mice reversed modulation of granuloma formation resulting in larger granulomas at 15 weeks. This abrogation of suppression was reflected in the spleens of the CY-treated mice, as seen by the inability of their spleen cells to adoptively transfer suppression to 6-week-infected mice. This regimen of CY treatment did not significantly alter anti-schistosome egg antigen hemagglutinating antibody titers. It is reasoned that the modulation of granuloma formation observed during chronic schistosomiasis mansoni is in part dependent upon a T lymphocyte and a CY-sensitive spleen cell.  相似文献   
89.
A crude preparation of Schistosoma mansoni soluble egg antigen (SEA) was subjected to affinity chromatography with concanavalin A (Con A) bound to Sepharose 4B. The resulting Con A fractions (bound and unbound) were characterized with sodium dodecyl sulfate (SDS) gel electrophoresis, immunoelectrophoresis, immunodiffusion, and lymphocyte blastogenesis techniques. In the fraction that did not bind to Con A there were at least two distinct antigens, and there were also at least two distinct antigens in the fractions that did bind to Con A. With SDS polyacrylamide gel electrophoresis, at least 20 distinct protein bands (Coomassie blue staining) and three glycoprotein bands (PAS reactive) were present in the unbound fractions from Con A chromatography. The bound fractions separated into at least six distinct glycoproteins with SDS electrophoresis. Although both the bound and unbound fractions contained precipitating antigens, only the bound fractions were capable of eliciting lymphocyte blastogenic responses.  相似文献   
90.
Parasites of two small fish species from a Ramsar wetland in South Africa were studied in 2014–2015. The cichlid Pseudocrenilabrus philander (Weber, 1897) was parasitised by the copepod Lernaea cyprinacea Linnaeus, 1758, the monogenean Gyrodactylus thlapi Christison, Shinn & van As, 2005 and four gryporhynchid metacestode (Cyclophyllidea) species: Paradilepis scolecina (Rudolph, 1819), Paradilepis maleki Khalil, 1961, Neogryporhynchus lasiopeius Baer & Bona, 1960 and Valipora campylancristrota (Wedl, 1855). The cyprinid Enteromius paludinosus (syn. Barbus paludinosus) (Peters, 1852) was infected with the monogenean parasites Dogielius intorquens Crafford, Luus-Powell & Avenant-Oldewage, 2012, Dactylogyrus teresae Mashego, 1983, and three Dactylogyrus spp. These results represent several new locality as well as host records and further contribute information on the parasitic diversity in the Barberspan Ramsar wetland.  相似文献   
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