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1.
A non-lethal dose of cysteamine — a radioprotective agent — when administered intraperitoneally was demonstrated to increase the susceptibility of mice to infection byPseudomonas aeruginosa. At numbers of cells (about 106) which killed 30–40 per cent of the untreated mice, the intraperitoneal treatment with 5 mg per day of cysteamine raised the mortality to 60 per cent. In contrast, the presence of 10 mg/ml of cysteamine in drinking water appeared to give some protection against the same number ofPseudomonas cells for the first three days after infection, but increased the susceptibility when the oral treatment was prolonged beyond three days. Such effects could have some significance in the study of sulfhydryl compounds as radioprotective agents.  相似文献   

2.
Summary The LD50's ofCandida albicans combined with Plurafac B26, Mulsor 224, Pluronic L62, and Polyethylene Glycol 400 Mono Laurate injected intraperitoneally into female white Swiss mice were calculated by the method ofReed &Muench. Each of the previously mentioned surface-active agent —Candida albicans combinations had a lower LD50 than theCandida albicans control.Plurafac B26 was found to intially decrease the number of leukocytes in the peritoneal cavity and thus enhance the invasiveness ofCandida albicans.  相似文献   

3.
Elimination of the non-specific binding of avidin to tissue sections   总被引:7,自引:0,他引:7  
Summary A simple procedure is described for eliminating non-specific staining with avidin—peroxidase conjugates. Murine ovaries were embedded in either paraffin wax or epoxy resin and, after blocking endogenous peroxidase activity, were treated with 10 µg/ml biotinylatedPisum sativum agglutinin. Avidin—peroxidase conjugates (5 µg/ml), diluted in standard 0.05m tris-buffered saline, pH 7.6, containing 0.139m NaCl, produced considerable background coloration and intense mast cell staining in controls without the lectin. This background diminished as the ionic strength of the buffer was raised. At 0.125m Tris-buffered saline (containing 0.347m NaCl) the background was completely unstained, with elimination of all binding to mast cells and only minimal loss of specific lectin binding.  相似文献   

4.
Summary and conclusion We have been able to establish typical characteristics of the species, in artificial culture media, of the fungus causingPosadas-Wernicke's disease. Our work is base on the study of ten strains of the fungus and on their retrocultures — obtianed by inoculation of these strains in laboratory animals — in variosu culture media, among them cornmeal agar (Emmons media) which in our opinion is a medium indispensable for the differencing and for the classification of the fungus from other agents which produce syndromes of a like nature.A revision was made of the literature of the morphology of the causal agent ofPosadas-Wernicke's disease and an analysis of the predominant and characteristic fructification of the fungus. In attention to the above facts, we think that the fungus in question should be included in the genusAleurisma Link, 1809. Therefore, admitting the validity of this genus, we believe that the name of the etiological agent ofPosadas-Wernicke's disease should be changed toAleurisma immitis, the diagnosis being justified by the microscopic study inEmmons media and completed by the forms found in a medium rich in glycides. The diagnoses is the following: Aleurisma immitis. — In substratis pauperibus gignuntur hyphis mycelicis hyalinis, septatis, satis ramosis, ramulis in angulo pene recto; aleuriis abundantissimis, valde simplicibus, centralibus et regulariter seriatis, vel apicalibus, rarissime lateralibus, sessilibus, rare pedicellatis, rectangularibus, hyalinis, aliquoties in racemis et thyrsis dispositis. Spirae saepe videntur. In substratis carbohydratis plenis, chlamydosporis intercalaribus et apicalibus abundantibus; aleuriis et spiris nec numerosis aut typicis quam in pauperibus substratis.(so called Coccidioidomycosis)  相似文献   

5.
Summary Observations on the nature, position and organs of attachment, the sucking organs, the alimentary canal and histopathology are recorded in the case of Pseudocycnus armatus (Bassett-Smith) parasitic on Indocybium guttatum (Bolch & Schn.) occurring along the South-West coast of India.  相似文献   

6.
The tritiated 1 antagonist prazosin [3H]PRZ binds specifically and with high affinity to postsynaptic adrenoceptors in membrane preparations from cerebral cortex. Since adrenoceptors are of protein nature, it was of interest of investigate the possible role of disulfide (—SS—) and sulfhydril (—SH) groups in the binding of [3H]PRZ. Pretreatment of the membranes with the disulfide and sulfhydryl reactivesdl0Dithiothreitol,l-Dithiothreitol, Dithioerythritol or 5,5-Dithiobis-(2-nitrobenzoic acid) (DTNB), alone or in combination with the alkylating agent N-Methylmaleimide (NMM), decreased specific [3HPRZ binding, with minor changes in the non-specific counts. Saturation experiments revealed that all these reagents reduced the affinity of the binding site for [3H]PRZ, as judged by theK d 25°C, but only the alkylating agent NMM and the oxydizing reagent DTNB produced in addition to the increase inK d, a decrease of the maximum binding capacity (B max). The present results provide evidence for a participation of—SS—and/or—SH groups in the recognition site of the 1-adrenoceptor of cerebral cortex.  相似文献   

7.
Large hovering flies with elongated nectar-feeding mouthparts play an important role in the pollination of South African plants. Here we describe and illustrate the pollination of two long-spurred orchids —Disa oreophila H. Bolus subsp.erecta Linder andBrownleea macroceras Sond. — by the long-proboscid flyProsoeca ganglbaueri Lichtwardt (Nemestrinidae).  相似文献   

8.
Genetic control of IgM responses to (T,G)-A — L   总被引:1,自引:1,他引:0  
The primary antibody response to aqueous immunization with a low molecular-weight lot of (T,G)-A — L (#420) was studied in congenic pairs of inbred mouse strains. Two new genetic controls were identified, both of which quantitatively regulate the production of IgM anti-(T,G)-A — L antibody. Testing of F1 and F2 progeny demonstrated that one of these genes is linked to the major histocompatibility (H-2) complex, and that high response is dominant over low response. Whether this gene is identical toIr-1A is not yet known. The other gene, designatedIg-TGAL M , is linked to the immunoglobulin heavy-chain allotype locus (Ig-1) and is expressed in a genedose dependent manner. Following secondary challenge with (T,G)-A — L 420, quantitative differences in IgG antibody response were observed inIr-1A high-responder congenics differing only at theIg-1 locus. Breeding studies, however, failed to demonstrate any linkage between this locus and the quantitative control of IgG anti-(T,G)-A — L antibody. These data demonstrate thatH-2-linked immune response genes can regulate IgM as well as IgG antibody responses, that genetic control of the IgM response to (T,G)-A — L is linked toIg-1, and that bothH-2-linked andIg-1-linked genes may simultaneously affect an IgM antibody response to the same antigen.Abbreviations used in this paper are (T,G)-A — L poly-l-(Tyr,Glu)-poly-d,l-Ala-poly-l-Lys - NMS normal mouse serum - SRBC sheep red blood cells - i.p. intraperitoneal - PBS phosphate-buffered saline - RAMG polyvalent rabbit anti-mouse globulin - 2-Me 2-Mercaptoethanol - 2-MeS 2-Me-sensitive - PFC plaque-forming cells - ABC antigen-binding cells  相似文献   

9.
Electrophoretic analysis of the developmental stages and tissues of Anopheles albimanus showed that qualitatively similar allozymes of aconitase (Acon-2) occur at all stages, and the enzyme is widespread in every larval and adult tissues. Relative heat stabilities of the allozymes were investigated by electrophoresis of heated aqueous extracts and by heating the enzyme in situ in acrylamide gels after electrophoretic separation in Tris-citrate and Tris-maleate buffer systems. The pupal aconitase in the crude extract is more stable to heat than the larval and adult enzyme. The presence of citrate ions in the gel increased the stability of aconitase to heat. Studies of substrate specificities indicated that cis-aconitic acid is the best substrate but citric acid can also serve as a substrate. Zymograms developed with isocitric acid as a substrate showed no aconitase electromorphs and produced only isocitrate dehydrogenase bands. Aconitase has a pH optimum of 8.0 and this enzyme is completely inhibited if treated in situ with ethylenediaminetetra-acetic acid (EDTA), p-chloromercuribenzoate (PCMB), and urea at concentrations higher than 5mm, 5×10–5 m, and 2 m, respectively. Acon-2100 and Acon-2105 do not respond differently to the above treatments. Genetic crosses involving a holandric translocation, pericentric inversions, visible mutants, and allozyme markers were analyzed to map the aconitase (Acon-2) locus on the left arm of chromosome 3. The gene sequence (and map distances) on 3L is centromere—esterase-8 (Est-8)—2—esterase-4 (Est-4)—25—esterase-2 (Est-2)—9—Acon-2—5—phosphoglucomutase (Pgm)—7—esterase-6 (Est-6).  相似文献   

10.
Zusammenfassung Die Doppelbrechung der Cornealinse und der Rhabdomere im Facettenauge von Calliphora erythrocephala (MEIG.) wurde untersucht.Der Gangunterschied wurde in Schnitten parallel zur Ommatidienachse gemessen. Die Differenz der Brechungsindices — die Doppelbrechung — zwischen dem außerordentlichen und dem ordentlichen Strahl ist (n en o) = 0,0012. Die Cornealinse ist ein einachsig, negativ doppelbrechender Kristall. Die optische Achse verläuft parallel zur Ommenachse.Die Kristallkegel und die Rhabdomerenkappen sind isotrop. Die Rhabdomere selbst sind anisotrop. Der Gangunterschied in den Sehstäben 1–6 (50 nm) scheint größer zu sein als im siebenten Rhabdomer (18 nm). Die Rhabdomere der siebenten und achten Sehzelle liegen jedoch genau hintereinander in einer Achse und dieTubuli sind zueinander senkrecht orientiert. Polarisationsoptisch gesehen liegen die beiden Sehstäbe in Subtraktionsstellung. Die Doppelbrechung der Rhabdomere ist (n en o) = – 0,0004.
Investigations with polarized light on the eye of Calliphora erythrocephala (Meig.)
Summary The birefringency of the corneal lens and of the rhabdomeres in the compound eye of Calliphora erythrocephala (MEIG.) was investigated.The phase difference was measured in sections parallel to the axis of the ommatidium. The difference of the refractive indices — the birefringency — between the extraordinary and the ordinary beam is (n e – n o) = –0,0012. The corneal lens is a negative birefringent crystal. Its optical axis runs parallel to the axis of the ommatidium.The crystalline cones and the extracellular distal processes of the rhabdomeres are isotropic. The rhabdomeres are anisotropic. The phase difference along the rhabdomeres No. 1–6 (50 nm) seems to be higher than in the seventh (18 nm). As rhabdomere No. 8 is situated beneath rhabdomere No. 7 and the tubules of these two rhabdomeres are perpendicularly orientated, the phase differences are partially cancelled. The birefringency of the rhabdomeres is (n en o) = –0,0004.
  相似文献   

11.
Summary Five new methods, based upon the selective oxidation of sialic acid residues with 0.4mm periodic acid in approximately 1m hydrochloric acid at 4°C for 1 h (PA*), have been devised for the simultaneous visualization of neutral sugars and either sialic acid and its side chainO-acyl variants orO-sulphate ester. In the first of these, the selective periodate oxidation—borohydride reduction—saponification—selective periodate oxidation—Thionin Schiff—saponification—borohydride reduction—periodic acid—Schiff (PA*—Bh—KOH—PA*—T—KOH—Bh—PAS) technique, sialic acids withO-acyl substituents at C7, C8 or C9 (or which have two of three side chainO-acyl substituents) stain blue while neutral sugars with periodate-sensitivevicinal diols (hexose, 6-deoxyhexose, andN-acetylhexosamine) stain magenta. The second method, the saponification—selective periodate oxidation—Thionin Schiff—saponification—borohydride reduction—periodic acid—Schiff (KOH—PA*—T—KOH—Bh—PAS), stains all sialic acids blue and neutral sugars magenta. In the third procedure, the selective periodate oxidation—Thionin Schiff—borohydride reduction—periodic acid—Schiff—saponification (PA*—T—Bh—PAS—KOH) method, sialic acids without side chain substituents (or which have anO-acyl substituent at C7) stain blue and neutral sugars stain magenta. In the fourth method, the saponification-selective periodate oxidation—borohydride reduction—Alcian Blue pH 1.0—periodic acid—Schiff (KOH—PA*—Bh—AB1.0—PAS) technique,O-sulphate esters stain aquamarine blue and neutral sugars stain magenta. In all of these techniques mixtures of the components stain in various shades of purple. Performance of the KOH—PA*—Bh—AB1.0—PAS technique without the Alcian Blue pH 1.0 step provides a method for the selective identification of neutral sugars in macromolecules that also contain sialic acids.  相似文献   

12.
In view of findings from previous studies that a chitin soluble extract (CSE) blocked adhesion of Candida albicans in vitro and in vivo and prevented thereby a short lived candidal infection in naive mice, we attempted in the present study to block by CSE the development of a persistent infection, induced in hormone-treated animals. Continuous oestrus phase was obtained in mice by repeated weekly subcutaneous injections with estradiol benzoate. Intravaginal inoculation of the hormone-treated mice with 107–1010 C. albicans cells induced a persistent candidal infection. Fifty three mice were pretreated intravaginally prior to inoculation of C, albicans with 2.5, 5.0 or 10 mg/mouse of a CSE cream and followed up for development of infection in comparison to 30 untreated animals. Twenty four hrs post fungus inoculation the infection rate among the CSE treated mice was 11–23% VS 84% among the controls; the rate increased a week later to 97% among the controls VS 41–50% among the CSE treated. Administering the CSE to the mice prior — and post-yeast inoculation (37 mice), led to increased efficacy of the treatment. The data, indicating that CSE is an effective measure for preventing persistent candidal vaginitis, may open the way to consider a similar approach for prophylaxis of vaginitis in human susceptible populations.  相似文献   

13.
Saponaria stenopetala sp.n. in Eastern Afghanistan is close toS. pachyphylla Rech. f. andS. subrosularis Rech. f.—The nearest allies ofS. makranica sp.n. from Western Pakistan and Southeastern Iran areS. kermanensis Bornm. andS. floribunda (Kar. & Kir.)Boiss.
Flora Iranicae praecursores 36–37. — Praecursores praecurrentes in Pl. Syst. Evol.139, 313–317 (1982).  相似文献   

14.
Summary The sex chromosomes of the male phasmid Isagoras schraderi Rehn comprise an X and a Y, — each with a submedian kinetochore, and one euchromatic and one heterochromatic arm. At meiosis X and Y form an unequal sex bivalent in which the euchromatic arms are terminally associated. Relatively recent reversion from the XO-XX mechanism characteristic of the Phasmidae is indicated by the presence of the euchromatic arm in both X and Y. The diploid number of the male is 34.Unequal autosomal bivalents are found at meiosis in two other species of Isagoras — Isagoras subaquiles Rehn and Isagoras sp. — and in Pseudophasma menius Westwood. The chromosome complements of these species are described.  相似文献   

15.
Summary A case of an accidental human infection caused byLeptospira ballum, following a superficial scratch on a finger of the patient while handling a white mouse is described. This mouse proved to be a urinary carrier ofLeptospira ballum.Further investigations revealed that practically all mice of the same colony voidedLeptospira ballum with the urine.On examination of other mice-breeding colonies another colony infected withL. ballum was detected; in 1941 a strain which later also proved to beL. ballum, was isolated from the urine of a white mouse.The various strains were analysed; they were serologically identical toBorg Petersen's type strain although the virulence for guinea-pigs was much less.Mice from aL. ballum-positive colony proved to have no immunity to infection with virulentL. icterohaemorrhagiae, but — with one exception — remained alive and became carriers ofL. icterohaemorrhagiae, whilstL. ballum could not be detected any more in the urine of these mice.  相似文献   

16.
Although guinea pigs are highly susceptible to experimental infection withLegionella pneumophila, mice are considered resistant. In the present study it was found that, although untreated mice resisted lethal infection with up to 107 L. pneumophila, mice treated with three divided doses of cyclophosphamide became 10–100 times more susceptible. Injection of mice with 150 mg cyclophosphamide/kg body weight 96 and 48h prior to and on the same day as intraperitoneal challenge with graded dose ofL. pneumophila resulted in markedly increased lethality. Approximately half of the mice pretreated with cyclophosphamide succumbed to 106 legionellae within 4–10 days after infection, and all treated animals given 107 bacteria died. Legionellae were readily recovered from spleen, lymph nodes, and liver of surviving mice 4–10 days after infection, but not thereafter. Sensitization of mice with Legionella antigen was evident by the lymphocyte blastogenic test in vitro, by use of spleen cells at various times after infection. Mice given graded doses ofL. pneumophila evinced enhanced responsiveness to either formalin-killed whole cell vaccine, cell-free sonicate, or purified outer membrane antigen when tested in vitro on days 3 and 5. Peak responses generally occurred 20–35 days after infection. Mice given none or one dose of cyclophosphamide and injected with legionellae showed enhanced responses on day 5 of culture in vitro, a time when spleen cells from control nonsensitized animals showed much lower responses. Surviving mice given three doses of cyclophosphamide had lower blastogenic responses, generally as low as that occurring with spleen cells from nonsensitized animals. Thus suppression of immune responses of mice by cyclophosphamide substantially increased susceptibility toL. pneumophila and depressed blastogenic responsiveness.  相似文献   

17.
Ohne ZusammenfassungBisher erschienen: Studien über die Lebenserscheinungen der Silphini. I. Silpha obscura L. Z. Morph. u. Ökol. Tiere 6, H. 2, 287 (1926). — II. Phosphuga atrata L. Z. Morph. u. Ökol. Tiere 9, H. 1/2, 271 (1927). — III. Xylodrepa quadripunctata L. Z. Morph. u. Ökol. Tiere 10, H. 2/3, 330 (1928). — IV. Blitophaga opaca L. Z. Morph. u. Ökol. Tiere 14, H. 1. 234 (1929). — V. Silpha tyrolensis Laich. Z. Morph. u. Ökol. Tiere 17, H. 1/2, 262 (1930). — VI. Blitophaga undata Müll. Z. Morph. u. Ökol. Tiere 18, H. l/2, I70 (1930). — VII. Oeceoptoma thoracica L. Z. Morph. u. Ökol. Tiere 20, H.4, 691 (1931). — VIII. Ablattaria laevigata F. Z. Morph. u. Ökol. Tiere 24, H. 2, 259 (1932). — IX. Silpha carinata Hrbst. Z. Morph. u. Ökol. Tiere 25, H. 2/3, 534 (1932). — X. Silpha tristis Illig. Z. Morph. u. Ökol. Tiere 28, H.4, 469 (1934).  相似文献   

18.
Listeria monocytogenes is a food-borne pathogen which causes mild to life threatening disease in humans. Ingestion of contaminated food delivers the pathogen to the gastrointestinal tract, where it crosses the epithelial barrier and spreads to internal organs. Type I interferons (IFN-I) are produced during infection and decrease host resistance after systemic delivery of L. monocytogenes. Here we show that mice benefit from IFN-I production following infection with L. monocytogenes via the gastrointestinal route. Intragastric infection lead to increased lethality of IFN-I receptor chain 1-deficient (Ifnar1−/−) animals and to higher bacterial numbers in liver and spleen. Compared to infection from the peritoneum, bacteria infecting via the intestinal tract localized more often to periportal and pericentral regions of the liver and less frequently to the margins of liver lobes. Vigorous replication of intestine-borne L. monocytogenes in the livers of Ifnar1−/− mice 48 h post infection was accompanied by the formation of large inflammatory infiltrates in this organ and massive death of surrounding hepatocytes. This was not observed in Ifnar1−/− mice after intraperitoneal infection. The inflammatory response to infection is shaped by alterations in splenic cytokine production, particularly IFNγ, which differs after intragastric versus intraperitoneal infection. Taken together, our data suggest that the adverse or beneficial role of a cytokine may vary with the route of infection and that IFN-I are not harmful when infection with L. monocytogenes occurs via the natural route.  相似文献   

19.
The adherence of Escherichia coli B cells to cell wall associated-agglutinin of the soil borne plant pathogen Rhizoctonia solani, was inhibited by l-fucose, l-galactose, trypsin, SDS, cycloheximide and Na2-EDTA. The coiling of the biocontrol agent Trichoderma harzianum around Rhizoctonia hyphae was prevented by SDS, cycloheximide, Na2-EDTA and methyl--l-fucoside — an inhibitor of Rhizoctonia agglutinin not metabolized by both fungi. The possible role of the agglutinin in Trichoderma-Rhizoctonia interaction is discussed.  相似文献   

20.
This paper aims at demonstrating the non-specific immunosuppression as regards thyme-dependent antigens sheep erythrocytes (SRBC) during the course of Candida albicans systemic infection.Three lots of syngeneic /BALB/c mice, 8–12 weeks of age, were used. The first normal lot was inoculated via the intraperitoneal route with a (SRBC) suspension (4×108 cells ml) in a Hank's balanced saline solution. The primary response of antibodies formed by splenic cells was measured from 4 to 8 days after inoculation using the direct plaque forming cells technique. The second lot was infected by the same route with a suspension of Candida albicans (1×107 cells). Positive retrocultures from the blood and kidneys of these infected mice were obtained. These yeasts cultivated in a Sabouraud medium were harvested after 20 h at 37 °C. Following the same methodology the immune response to SRBC was determined. The serum obtained from infected mice was transferred to a third lot of mice at different intervals during the course of the infection. The immune response to SRBC was done by the direct plaque-forming cells technique. Controls were carried out using normal donors and recipients.A suppression of the immune response was obtained as from the 2nd day of inoculation up to the 28th day. It was not possible to transfer such suppression passively by means of the serum.These results suggest that the systemic infection by Candida albicans induce a non-specific immunosuppression in the organism, already demonstrated in viral infections, bacteria, protozoaria and metazoaria in mammals.In some way, this will contribute to explain the mechanisms of immune response to Candida albicans.  相似文献   

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