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21.
Monoclonal antibodies specific for Leishmania tropica. I. Characterization of antigens associated with stage- and species-specific determinants 总被引:8,自引:0,他引:8
Four monoclonal antibodies (T-1 through T-4), which were produced to membrane-enriched preparations of Leishmania tropica major promastigotes, reacted specifically with the members of L. tropica complex. The antibodies T-1 and T-4 react exclusively with L. t. major and L. t. minor. The remaining two monoclonal antibodies bind, in addition, to L. t. aethiopica and weakly to L. mexicana amazonensis. No significant cross-reactivity was observed with L. donovani, L. braziliensis braziliensis, and Trypanosoma cruzi. Antibodies T-1, T-2, and T-4 were found to be specific for the promastigote stage (insect) of L. tropica. Antibody T-3 reacts with both the amastigote and promastigote stages of the parasite. All of the monoclonal antibodies react with cell surface components on intact promastigotes. The protein antigens containing the species-specific determinants recognized by each of the four antibodies were identified by radioimmunoprecipitation of solubilized 125I-labeled L. t. major promastigotes. A single 50 kilodalton protein is recognized by clone T-4. T-1 recognized two high m.w. proteins (100 and 200 kilodaltons). These two antigens plus an additional protein of lower m.w. (70 kilodaltons) are also immunoprecipitated by the antibodies T-2 and T-3, demonstrating that species-specific determinants are present on several different cell surface proteins of L. t. major. 相似文献
22.
Samples of the perivitelline fluid in the polar pockets of preblastoderm Drosophila embryos were analyzed with an electron microprobe, and the results compared with analyses of adult hemolymph. The concentrations of sodium, magnesium, calcium, chlorine, and phosphorus are about the same in these two fluids; but potassium and sulfur are three to four times higher in perivitelline fluid. Moreover, the concentrations of these elements in the anterior and posterior pockets of the same embryos were compared. The former five elements seem to be about 10% more concentrated in the anterior pocket; but the latter two show no significant difference between pockets. 相似文献
23.
The ontogeny of strombid behavior was studied by observing thebehavior of Strombus maculatus veligers collected from the planktonand reared past metamorphosis to adults, and by observing juvenilestrombids collected in the field. Complete adult modal actionpatterns (MAP's) associated with locomotion, feeding, and rightingof overturned shells are performed by S. maculatus juvenilesimmediately after metamorphosis. There are changes in the frequencyof the use of certain MAP's which are associated with variationsin shell shape and size. The unique strombid escape response to molluscivorous gastropods(Conns spp.) is not released until juvenile S. maculatus arethree weeks past metamorphosis and two millimeters in shelllength. At that stage, the complete response is released uponthe first encounter with a predator. Experience with a predatordoes not seem to lower the age or size criteria. During ontogeny there is a trend toward an increasing complexityof behavior which is paralleled by an increasing complexityof neural structure and general morphology. There are majorsteps in the ontogeny of strombid behavior which probably coincidewith neural and morphological stages. 相似文献
24.
SYNOPSIS. The iguanid lizard Basiliscus basiliscus in Panama is parasitized by Plasmodium basilisci and P. achiotense sp. nov. P. basilisci in this host is characterized by schizonts containing 4–14 merozoites, with schizonts parasitizing proerythrocytes containing more merozoites than those in erythrocytes. Asexual parasites lack cytoplasmic projections, while mature gametocytes are round or oval with regular margins.
P. achiotense is characterized by the combination of prominently pigmented, large schizonts containing 36–56 merozoites and oval or round gametocytes which are about 1/3 larger than those of P. basilisci.
EE-schizonts of P. basilisci were observed commonly in thrombocytes and occasionally in lymphocytes, and appeared early in experimental infections induced by blood inoculation. 相似文献
P. achiotense is characterized by the combination of prominently pigmented, large schizonts containing 36–56 merozoites and oval or round gametocytes which are about 1/3 larger than those of P. basilisci.
EE-schizonts of P. basilisci were observed commonly in thrombocytes and occasionally in lymphocytes, and appeared early in experimental infections induced by blood inoculation. 相似文献
25.
26.
SYNOPSIS. Plasmodium balli sp. nov. is described from Anolis lionotus and A. poecilopus of central Panama.
Large, elongate gametocytes and segmenters containing up to 100 merozoites are produced by P. balli. Proerythrocytes and normoblasts are more commonly parasitized than erythrocytes. Pigment is uncommon, but when present consists of a minute dot. Hypertrophy, distortion and lysis of host cell nuclei may result from parasitization of immature blood cells by gametocytes, while enucleated host cells are common. 相似文献
Large, elongate gametocytes and segmenters containing up to 100 merozoites are produced by P. balli. Proerythrocytes and normoblasts are more commonly parasitized than erythrocytes. Pigment is uncommon, but when present consists of a minute dot. Hypertrophy, distortion and lysis of host cell nuclei may result from parasitization of immature blood cells by gametocytes, while enucleated host cells are common. 相似文献
27.
The Control of Color in Mammals 总被引:1,自引:0,他引:1
SYNOPSIS. Recent advances in the biology of mammalian pigmentationare reviewed.Particular attention is given to emerging informationon the integration of pigmentary events occurring at differentlevels of biological organization within mammalian skin andhair. The structural and functional significance of keratinocytesand melanocytes as components of mammalian epidermal melaninunits is viewed from this perspective. New evidence on the natureof genetic, developmental, endocrine, and radiation influenceson performance of melanocytes and the establishment of pigmentarypatterns is summarized. 相似文献
28.
The fixing-staining mixture consisted of 1 part of 2% aqueous OsO4 and 3 parts of 3% Nal in distilled water. Fresh lungs were cut into 2 mm slices and immersed in this solution for 24 hr at room temperature. Controls were fixed in buffered OsO4 alone. Selective staining of type II alveolar cells was shown by the OsOt-NaI mixture but was absent in the controls. No additional staining of the sections was required, and the selectivity was readily observable in either paraffin or Araldite sections by light microscopy and in Araldite sections by electron microscopy 相似文献
29.
Partitioning of respiratory flow resistance in man 总被引:9,自引:0,他引:9
30.