The immunogenicity of Westphal lipopolysaccharides (LPS) from 2 strains of Pasteurella multocida was tested in mice. When lipopolysaccharide from P. multocida strain P-1234 (bovine source) was inoculated into CF1 or mice, less than 20 per cent of the mice survived homologous challenge infection 4 weeks later. However, 90 per cent, or more, of the CF1 or mice survived homologous challenge infection after immunization with formolized P-1234 bacteria. Sera from the CF1 mice, but not mice, formed precipitin lines against P-1234 LPS in an agar gel diffusion test.Hyperimmune sera from rabbits inoculated with formolized P-1234 bacteria passively protected more than 80 per cent of the CF1 mice against challenge infection; however, sera from rabbits inoculated with P-1234 LPS or LPS adsorbed to sheep red blood cells protected less than 20 per cent of the challenged mice.Absorption of rabbit anti-whole cell sera with LPS slightly reduced the capacity of serum to passively protect mice against challenge exposure. 相似文献
Six groups of 8 4-month-old cross-bred lambs were used to investigate the effect of daily intakes of Ostertagia larvae on skeletal growth. One group was killed at the onset as control. The remaining groups were offered a complete ruminant ration ad libitum and dosed with zero (group ALC control), 1000 (group 1), 3000 (group 2), 5000 (group 3) and 5000 (group 4) larvae of Ostertagia circumcincta per day for 12 weeks. Group 4 also received a single dose of anthelmintic (fenbendazole) on days 21, 42, 63 and 84 of infection. All sheep were killed after 14 weeks and selected bones removed for histological and chemical evaluation.None of the sheep showed obvious clinical signs of infection and mean worm egg counts were less than 400 e.p.g. Deposition of calcium in the carcase of Ostertagia infected sheep was reduced by 11, 35, 57 and 27 per cent in groups 1, 2, 3 and 4, respectively. Phosphorus deposition was similarly affected.Growth in volume of the tibia, rib and vertebra was reduced in groups 2, 3 and 4, compared to controls (ALC). There was also a reduction in the amount of ash per unit volume of bone in groups 2 and 3, mainly due to a decrease in bone matrix, although in the more severely affected animals mineralization of bone matrix was slightly reduced. Anthelmintric treatment did not prevent retardation of bone growth but it did improve the quality of the skeleton.Intakes of 1000 Ostertagia larvae per day did not significantly affect any of the bone parameters. 相似文献
The effect of oral administration of upon the testicular germinal epithelium was studied in the rat and monkey. A single oral dose of 100 or 200 mgm/kgm given to mature male rats was not effective, but five consecutive doses of 200 mgm/kgm produced marked decrease in testicular weight and complete inhibition of spermatogenesis, while the weight and histology of the prostate and seminal vesicles were not affected. Daily doses of 10 mgm/kgm for 37 weeks or five consecutive doses of 50 mgm/kgm for 1 week were ineffective in the monkey. However, when the five dose regimen was followed by single weekly doses of 50 mgm/kgm for 6 months, complete inhibition was achieved and maintained in the monkey after 8 weeks. Daily doses of 100 mgm/kgm for 6 months resulted in inhibition of spermatogenesis.Preliminary studies with AF 1890 (an analog of ) given at levels of 50 mgm/kgm for 5 days to rats resulted in complete inhibition of spermatogenesis. The activity of this analog was four times greater than . In monkeys, a daily dose of 200 mgm/kgm for 2 weeks also resulted in suppression of spermatogenesis. 相似文献
A state of immunity in against the pathogen is known to be induced by the injection of lipopolysaccharide (LPS), isolated from the homologous organism. An mixture of the LPS and whole or cell-free hemolymph from non-immunized larvae is not antibacterial. mixtures of fat body and cell-free hemolymph from non-immunized larvae, incubated at 25°C for 20 hours generated a proteinaceous antibacterial activity. The generation of this activity was enhanced by the presence in the incubation mixture of LPS and/or hemocytes from non-immunized larvae. It is suggested that LPS causes the release of a hemocyte factor(s) which acts in conjunction with or directly on the fat body resulting in an enhanced production of antibacterial factors. 相似文献
The effects of syngeneic (CBA×CBA) and allogeneic () pregnancy on immunoglobulin (Ig)-secreting cells in various maternal organs/tissues have been investigated by using the protein A plaque assay. The following organs/tissues were examined: ) spleen, ) cervical nodes, ) inguinal nodes, ) mesenteric nodes, ) paraaortic (uterus-draining) nodes, ) Peyer's patches, and ) bone marrow (femur). The changes observed were similar and of the same magnitude in all pregnant animals, irrespective of the type of mating. At mid-gestation (day 14) a distinct increase in Ig secretors was observed, predominantly in the spleen. At the end of pregnancy (day 20) the para-aortic nodes contained dramatically increased numbers of plaque forming cells. A slight increase in both IgM and IgG-secreting cells was also seen in bone marrow at the very end of pregnancy, while Peyer's patches and the nodes of neck and legs appeared to be unaffected throughout the period of gestation. 相似文献
1-p Chlorobenzyl-1H-indazol-3-carboxylic acid or was given to rats in the diet for periods of time ranging from 5–180 days. Body weight, weight and histology of the main internal organs, food consumption, serum levels of the drug and blood composition were determined. The most extensive experiment was performed in young rats treated up to 180 days with a diet containing 0.5% AF . A marked and constant reduction in the weight of the testes with inhibition of spermatogenesis was observed during the entire experiment. In rats treated for 20–80 days a reduction in the weight of the ventral prostate, seminal vesicles and levator ani was also observed with a histological picture of hyposecretion of the above-mentioned glands: These effects were no longer detected following a 180-day treatment. The influence of doses and age on the effects of was also studied on the basis of a 30-day treatment period. In young rats, effects on spermatogenesis were not separated from effects on the accessory sex organs even with the lowest doses; in mature rats, instead, the spermatogenic process was specifically inhibited even with the highest doses. AF was without effects in female rats. The toxicological tests gave no evidence of systemic toxicity of the drug. 相似文献
The kinetics of heat-induced lysis of a population of sheep red blood cells over the temperature range 42°–56°C are shown to be similar in form to the survivorship curves of multicellular organisms and are describable by the power law function, . The A parameter of the power law function is examined in this model system in an attempt to show its relationship to molecular events. Arrhenius-type plots of the A parameter are different for old populations of red blood cells compared to young populations. The plot for the old cells shows a high energy transition at 50°C. For the young ceils an activation enthalpy of 132 kcal/mole is obtained with no transition occurring at 50°C. The parameter , defined as is more directly related to the molecular basis of the temperature dependence of the lysis kinetics. The Arrhenius plots of give activation enthalpies of 42.8 and 40.4 kcal/mole for young and old cells, respectively, and activation entropies of 57.6 and 50.3 cal/mole per degree. These activation enthalpies and activation entropies appear to be in accord with a compensation law for these qualities for protein denaturation, and support the suggestion that protein denaturation is the rate-limiting step in the lysis of sheep red blood cells. 相似文献
Antisera against rabbit and human β2-microglobulin were produced in carp (). These antisera were found to be specific for β2m, and detected β2m epitopes in various vertebrates including guinea-pig, cow, mouse, rat, dog, horse, cat, sheep, goat, parrot, chicken and frog. In addition, these antisera were also inhibited by an extract from oyster. The differences between the reactivity of these two antisera and the ability of the anti-rabbit β2m to distinguish between mouse and rat β2m's suggested that the carp itself carries β2m epitopes. This hypothesis was corroborated by the ability of a variety of mammalian anti-β2m antisera to induce a mitogenic response in carp leukocytes. Finally, a rabbit antiserum against dog β2m was shown to precipitate a low molecular weight molecule from carp leukocyte extract. This molecule is likely to represent the carp homologue of mammalian β2m. 相似文献
Thymus-dependent immune functions were investigated in chickens bursectomized neonatally with colchicine solution given . Antibody responses to thymus-dependent antigens sheep red blood cells (SRBC) and human gammaglobulin (HGG) were delayed, reaching the normal level after the third antigen stimulation. Also the mitogenic responses of peripheral blood lymphocytes were preserved, and no changes in the thymic morphology were found. In contrast, antibody responses to bursa-dependent antigen were low and the switch of immunoglobulin isotypes from IgM to IgA and IgG was disturbed. It can be concluded that neonatal bursectomy with cloacal administration of colchicine does not significantly affect T celi functions, whereas B cell functions are partially deficient. 相似文献
Two experiments were conducted, one in the rat and one in man, to ascertain the effects of equicaloric loads of protein, fat, carbohydrate, and a mixture of these, on subsequent food intake. Additionally, non-caloric loads were given. In the rat, loads were administered intragastrically, and ad lib food intake was measured after various intervals. Corn-oil loads suppressed food intake less than other equicaloric loads. This suggests that calorie-for-calorie, fat does not suppress intake as much as protein or carbohydrate. Sucrose loads suppressed food intake the most after 1 hr. Mixture loads had an effect equal to the average of its components after 24–72 hr. In man, loads were given orally after a 13-hr fast. Differences between loads were minimized by suppressing olfaction with noseclips, and taste with topical anesthesia of the mouth. Consumption of test-meal presented 70 min later was measured. Also, various ratings of appetite were made. No differences were found between intakes or ratings after individual loads. But collectively, caloric loads suppressed food intake more than non-caloric loads. 相似文献
Cell-mediated immunity in the American cockroach, , was measured by counting nuclei in a transect through the mass of host hemocytes reacting against transplanted xenograft or autograft integument. Responses to xenografts () were significantly higher than control responses to autograft integument. Responses to xenografts increased with longer durations of xenograft exposure to hosts for up to eight days, then decreased by day sixteen. Responses to cockroach species from a phylogenetically graded series of donors were stronger and correlated with increasing phylogenetic distance between various donors and hosts (). 相似文献
produced relatively heat-stable, dithiothreitol-sensitive, non-precipitating antibodies with β2-electrophoretic mobility following exposure to promastigotes but no histopathological or clinical signs of infection were seen. Significant four-and two-fold increases in the mean lysozyme and protein levels respectively were found in immune sera. Immunoenzyme techniques proved the most sensitive for detection of parasite antigens in selected body organs and immunoglobulins in sera. 相似文献
Adult ovariectomized hamsters which were implanted with Silastic capsules containing estradiol benzoate (EB), progesterone (P) or nothing (Blank) were exposed to prolonged constant light (LL) with free access to running wheels. Freerunning locomotor rhythms were recorded on an event recorder. Light energy levels averaged 12.2 uwatts/cm2 or 48.3 Lux. Rhythm splitting occurred in animals given EB, given P and Blank implanted animals. Altogether, EB, P and Blank implanted animals showed some form of splitting or other rhythm anomaly such as desynchrony of endogenous oscillations. There was a high incidence () of animals showing an additional transient rhythmical component running across the split condition. The study supports the concept that a multi-oscillatory system normally generates a cohesive circadian behavioral rhythm. Estradiol appears to facilitate the synchrony of these oscillations. 相似文献
A new antispermtogenic agent is described. Following single or short-term administrations, 1-p-chlorobenzyl-1H-indazol-3-carboxylic acid, or , produced in rats a long-lasting inhibition of the spermatogenic process. In adult rats the secondary sex organs were not affected, while in young rats some weight decrease of the prostate, seminal vesicles and levator ani was observed. The interstitial tissue of the testes as well as thymus, adrenals and hypophysis were not affected. proved to be devoid of the most common pharmacological activities. 相似文献
The HA-2 agglutinin purified from haemolymph is shown to mediate the binding of sheep erythrocytes to mouse macrophages. This agglutinin appears to be wholly responsible for the adhesive activity of haemolymph, since upon chromatography of the latter through Sephadex G-200, the adhesive activity for both sheep and guinea pig erythrocytes was confined to those fractions containing the HA-2 agglutinin. The HA-1 agglutinin recovered in earlier fractions was unable to promote the adhesion of guinea pig erythrocytes to macrophages. Adsorption experiments indicated that this was due to a lack of ligand sites on the macrophage surface. These data support earlier conclusions that the HA-1 and HA-2 agglutinins have distinct binding specificities. 相似文献
A FORTRAN IV algorithm is given for determining the hydrodynamic parameters of a macromolecule in solution for any specified value of the two axial ratios (, ) of the equivalent triaxial ellipsoid model of semi-axes a ≥ b ≥ c for its gross conformation. 相似文献
To determine the effect of diet on bulimia, a treatment group of 10 bulimic women were placed for 6 weeks on a nutrient-dense diet containing no fewer than 1400 calories and free of suspected blood sugar-insulin level destabilizers. Simultaneously, a control group of 10 bulimic women were placed on a Sham Food Plan which allowed unknowing duplications of their pre-study food patterns. After three weeks they were switched to the nutrient-dense diet for the remainder of the study. No subject received psychiatric counseling. The treatment group assigned to the nutrient-dense diet ceased to binge (, sign test). The control group on the sham diet binged steadily until switched to the nutrient-dense diet, after which, all binging ceased. Subjects lost weight effortlessly (or maintained weight by choice) and have remained binge free for over 2 years. Evidence suggests that malnutrition and blood sugar-insulin level destabilizers may play a role in precipitating the bulimic condition. 相似文献
The combining site of purified Vicia villosa lectin was studied by quantitative precipitin and precipitin inhibition assays. The lectin, which specifically hemagglutinated blood group A erythrocytes nevertheless precipitated to different extents with blood group A1, A2, H, B and precursor I substances from saliva and ovarian cysts, and with different blood group substances of the same specificity indicating an interaction of the lectin with a non-blood group determinant site. The agglutinating and precipitating activities of the lectin were not strongly affected by EDTA or bivalent cations. Precipitates of Vicia villosa lectin with certain blood group glycoproteins showed unusually high solubilities as compared to other lectin glycoprotein and antigen-antibody precipitates. Inhibition assays with various monosaccharides, glycosides and oligosaccharides indicate that the Vicia villosa lectin is specific for terminal, non-reducing, α-linked dGalNAc. Of the monosaceharides tested, methyl αdGalNAc, p-NO2-phenyl αdGalNAc and dGalNAc were best. They were about 100 times better inhibitors than the corresponding dGal compounds. The most potent inhibitor was methyl αdGalNAc which was 10 times more active than dGalNAc and 18 times more potent than the β-anomer. Among disaccharides tested, dGalNAcαl → 3dGal was most active, about as potent as methyl αdGalNAc, twice as active as dGalNAcαl → 6dGal and 8 times more potent than , indicating the importance of a subterminal in the binding. was 7 times less active and the blood group A determinant was less than as active as . These findings indicate that the combining site of the Vicia villosa lectin is at least as large as the disaccharide and that the αl → 3 linkage is important in the binding. The unique nature of this site is consistent with its high specificity for a glycoprotein on cytotoxic T-lymphocytes. 相似文献
Experiments utilizing a range of bacteria of differing pathogenicities injected into larvae have shown that:1. At levels above 103 bacteria/μm hemolymph, phagocytosis is usually augmented by nodule formation.2. The cellular defenses elicited are dependent on the nature of the test bacteria.3. Non-pathogens are effectively contained and killed within nodules while pathogenic forms can escape from these structures and induce a fatal septicemia.4. Hemolymph from naive insects contains no antibacterial factors.5. Bacteriostatic and bactericidal factors can be induced in larvae by immunization with pathogens, non-pathogens or saline.These results are discussed in terms of the interaction of cellular and humoral defense reactions in the production of an integrated and complete immunoresponsiveness. 相似文献