Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Diethylcarbamazine (DEC) produced an initial stimulation followed by depression of the movements of the intact worm and nerve-muscle preparation of Setaria cervi. The effective concentration of DEC was reduced to one hundredth in the nerve-muscle preparation as compared to the whole worm, suggesting that the cuticular barrier is highly effective in preventing the penetration of the drugs. The depressant effect of DEC was concentration dependent and was not reversed even after repeated changes of the bath fluid. The worms consumed 7.7 mg +/- 0.2 glucose/g wet weight/hr. The consumption of glucose was directly proportional to its motor activity; it increased during the stimulant phase with low doses of DEC and decreased during the depressant phase.
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PMID:Effect of diethylcarbamazine on Setaria cervi in vitro. 68 Sep 45

Inbred rats were thymectomized, irradiated, and reconstituted with T cell-free bone marrow cells. Thymectomized-reconstituted (B rats) and control rats were infected with Schistosoma mansoni cercariae and the number of worms recovered was determined at various times after infection. The extent of immunosuppression was assessed by two criteria: 1) response to an injection of sheep erythrocytes (plaque assay, hemagglutination, hemolysis); 2) response to schistosome antigens (passive hemagglutination). Humoral responses to worm antigens were completely suppressed in almost all instances and anti-sheep erythrocyte responses showed a more variable but always very definite depression in B rats. The number of worms in B rats was about 4 times higher than in control animals at 5 weeks and about 3 times higher at 6 weeks. In a different experiment, rats were perfused at 4, 6, and 9 weeks after infection and the number of worms was found to be consistently higher in B rats, by a factor of about 2 at 4 weeks to a factor of about 4 or 6 at subsequent times. Although B rats had more worms than controls even at 9 weeks, a slow drop in their worm burden was noticeable with time in both experiments. Moreover, the size of worms in B rats was smaller than in controls and even 9-week-old worms failed to develop to normal size and appearance and could not be shown to produce fertile eggs. These experiments show a definite involvement of the immune system in the "self-cure" phenomenon, but may at the same time suggest that other non-immune mechanisms are involved in determining the pattern of S. mansoni infection in the rat.
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PMID:The course of Schistosoma mansoni infection in thymectomized rats. 77 68

Observations were made on the development of acquired resistance to Schistosoma haematobium in the baboon following immunization with cercariae by the percutaneous route and by the transplantation of adult worms into the mesenteric veins. In the first experiment six baboons were immunized with 1000 S. haematobium cercariae given percutaneously. They were challenged with 10 000 cercariae given 73 weeks later and the results were compared with a similar infection in non-immunized animals. The results showed that the baboon can develop a strong resistance to reinfection with S. haematobium. The manifestations of the immunity were (i) the absence of any increase in egg output after challenge (ii) the substantially lower level of adult worms and eggs in the tissues of the immunized baboons compared with the challenge control animals (iii) a reduction in the egg laying capacity of the residual worms and (iv) the virtual absence of gross pathology and the mild lesions seen in the tissue sections of all the immunized animals. The depression in egg laying of the worms was confirmed by transplanting them into non-immune baboons. This experiment indicated that the non-egg-laying worms in the immune baboons were not irreversibly damaged since they survived, some even migrating to the vesical and ureteric vessels, and egg-laying was rapidly resumed after transplantation. A further experiment was designed to see if a similar degree of immunity could be produced by an adult worm infection without previous exposure to cercariae or schistosomula. The immunization dose consisted of 50-100 S. haematobium worm pairs which were transplanted into the mesenteric veins of each of six baboons and the animals were challenged percutaneously with 7000 cercariae 35-55 weeks later. There was little difference in the worm burdens of the immunized and control animals but the worms in the immunized baboons produced fewer eggs and the pathology seen in these animals was much milder than in the challenge control animals suggesting that some degree of resistance to reinfection was produced by the transplanted worms.
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PMID:Acquired resistance to Schistosoma haematobium in the baboon (Papio anubis) after cercarial exposure and adult worm transplantation. 82 26

Purebred Hampshire pigs, farrowed and maintained under conditions precluding extraneous helminth infection, were exposed to a single dose of 10,000 Ascaris suum infective eggs. The pigs were killed at intervals of 28, 41, 55, 86, 115, 145, 175, and 206 days after infection. At necropsy, no gross lesions were found in the lungs or livers of infected pigs. The worms were recovered from the small intestine, identified, counted, and fixed. The heads were excised, critical point dried, mounted en face, and examined by scanning electron microscopy. Worms 28 to 115 days old had unworn denticles that were triangular when viewed laterally but blunt when viewed tangentially. Wearing of the denticles was observed first with 145-day-old worms; wearing increased with age both in numbers of denticles affected and in degree of wear so that by 206 days after inoculation, almost all denticles in the center of the lip were worn. Worn denticles appear truncated when viewed from any angle. The denticles outside the central area were not affected by wear. The size of the denticles varies not only between specimens of the same age, but also on each specimen. However, average denticle size is directly related to the size and, accordingly, to the age of the worm. External to each denticle is a corresponding depression that we have called the denticular groove. One 28-day-old specimen had some extra denticles aligned irregularly along the lip; this irregularity gave the appearance of a double row. The denticles of the two subventral lips are similar to those of the dorsal and are equally affected by wear. There was no detectable difference in denticles of male and female worms. Since wear can now be specifically correlated with age, we conclude that the denticles are functional and become worn through use. Consequently, adult A. suum may be an even more injurious pathogen than heretofore supposed.
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PMID:Scanning electron microscopy of the lip denticiles of Ascaris suum adults of known ages. 126 37

To understand the mode of anthelmintic action of thiabendazole and methyl-[5-[[4-(2-pyridinyl)-l-piperazinyl]carbonyl]-1H-benzimidazole- 2-yl] carbamate (C.D.R.I. compound 81/470) against Nippostrongylus brasiliensis, their effect on the metabolism of reactive oxygen species in the parasite as well as in rat intestine was examined. Both drugs produced a significant depression in the levels of superoxide dismutase (SOD) and reduced glutathione (GSH) of the parasite. Release of antioxidant enzymes by the drug-treated worms was also found to be appreciably lowered. Both thiabendazole and compound 81/470 induced a depression in the levels of all five constituents of the antioxidant system of rat intestine but significant alterations were detected only in the GSH content of infected and the SOD activity of normal intestine. The production of O2- by treated intestine was, on the other hand, markedly enhanced. Increased formation of O2- by the host intestine accompanied with the reduced level of SOD and GSH in N. brasiliensis appear to have a deleterious effect on the parasite. Consequently, the drug-treated worms are unable to retain themselves in situ and are ultimately expelled. The greater effect produced on these parameters by thiabendazole compared to compound 81/470 is consistent with the relative efficacy of these anthelmintics.
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PMID:Effect of anthelmintics on the antioxidant system of Nippostrongylus brasiliensis. 173 17

Immunity in mammals to intestinal cestodes has been reviewed using the normal final host infected with the tapeworms Hymenolepis diminuta in rats and H. microstoma and H. nana in mice as a model. Primary infections up to a certain level continue to live as long the host, while most worms in infections with larger doses are destrobilated and expelled. It has been argued that concomitant immunity against a superimposed infection exists in rats and mice infected with H. diminuta and H. microstoma, respectively, and suggested that it also takes place in humans infected with Taenia spp. Immunity to secondary infections after expulsion of a primary infection occurs, but immunological memory is rather short-lived, although depression of worm growth occurs for at least two third of the rat's life. Serum antibodies have been shown to produce a direct precipitate on the surface of cestodes in vitro, but a direct effect of antibodies in vivo or the relationship with e.g. host effector cells, like mast cells and eosinophils, is unknown. It has been shown that peritoneal exudate cells from rats are able to kill H. diminuta in vitro. Very little is known about the mechanisms of tapeworms to counteract host immunological responses, but the tegumental glycoconjugates and discoidal secretory bodies are possible candidates. Passive transfer of immunity by mesenteric lymph node cells has only been successful using cells from H. nana egg-infected mice and has shown that only short-lived proliferating cells are responsible for transferring immunity. Vaccination procedures and problems are discussed with special reference to E. granulosus in dogs.
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PMID:Immunity to adult cestodes: basic knowledge and vaccination problems. A review. 184 Nov 94

Five mouse strains, CBA/J, BALB/c, C3H/HeJ, A/J, and C57Bl/6J-bg-bg, all showed similar expulsion kinetics for Nippostrongylus brasiliensis (infective dose = 500 L3). Typically, parasite recovery was maximal on day 2 in the lungs and by day 4 in the small intestine. Few worms (less than 5% infective dose) were recovered on day 14 in all strains. These same mouse strains exhibited immune depression on day 5 of infection with mesenteric lymph node cells (MLN) showing reduced (10-30% normal) IgM, IgG, and IgA responses against heterologous antigen. The intestinal mast cell numbers and tissue histamine levels were examined in CBA/J mice. Mast cell numbers increased (normal = less than 1/villous crypt unit; VCU) from day 5 and peaked on day 12 (greater than 15/VCU). Intestinal histamine levels did not completely correlate with mast cell numbers with maximum concentrations (240 +/- 73 ng/g, 2-fold over normal) reached by day 8. Histamine concentrations in the intestine returned to normal levels by day 20.
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PMID:Characterization of Nippostrongylus brasiliensis infection in different strains of mice. 235 68

Neonatal hamsters were exposed to varying doses of Necator americanus larvae and changes in the stability of the resulting worm burdens were monitored over a period of 25 weeks. No change in worm burdens was evident for the first 5 weeks of infection, irrespective of the infection intensity, but the more heavily infected groups subsequently lost worms in a density-dependent manner. Male and female hamsters lost comparable proportions of their established parasite burdens indicating that there was no host sex-linked difference in this respect. By week 15 infections had stabilized and the residual worm burdens, usually a maximum of 30 worms survived for a considerably longer period of time. Initially the percentage of male worms varied from 45% to 50% but as infection progressed male worms comprised a significantly increasing proportion of the total worm burden. By week 25 the percentage of male worms was usually in excess of 60%. The growth of infected animals was not severely affected by N. americanus, even when heavy worm burdens established initially, but a significant effect was detected particularly in week 5, prior to worm loss, when the adult worms would have been feeding on intestinal tissues and causing blood loss for a period of about 2 weeks. The most severe depression in the packed cell volume was also recorded in week 5, indicating that anaemia had been initiated in infected hamsters. Whilst, the regulation of parasite burdens in weeks 5-10 post-infection may have resulted from host immunity, the persistence of the residual worm burdens, the marked density-dependent anaemia and the subtle effect on host weight, all reflected well-documented aspects of chronic human necatoriasis.
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PMID:Necator americanus in the DSN hamster: density-dependent expulsion of adult worms during primary infection. 236 72

The relative influence of Ah vs H-2 genotype on the outcome of Trichinella spiralis (Tsp) infections of mice was examined following methylcholanthrene (MC) treatment. Female mice of four inbred strains were treated with MC and infected 24 h later with Tsp muscle larvae. The strains, with their respective major histocompatibility complex (MHC) haplotype, aryl hydrocarbon hydroxylase responsiveness (Ah phenotype) and level of susceptibility to Tsp infection, were: C3HeB/FeJ (C3), H-2k, Ahb, Tsp susceptible; C57BL/10.BR (B10.BR), H-2k, Ahb, Tsp susceptible; C57BL/10.Q (B10.Q), H-2q, Ahb, Tsp resistant; and AKR/J (AK), H-2k, Ahd, Tsp resistant. The proliferative response of splenic lymphocytes to crude Tsp L1 stage antigen was significantly depressed in all MC-treated groups, with the exception of the B10.BR strain. MC administered at 40 mg/kg impaired the ability of C3 and B10.Q mice to eliminate adult worms. At 80 mg/kg, C3 strain mice were also impaired, as well as AK strain mice. The fecundity of female worms recovered from B10 or AK strain mice was not significantly altered by MC treatment, although female worms from treated C3 mice exhibited increased fecundity on day 9 post infection. Muscle larvae burdens of MC-treated B10 and C3 mice were elevated, while those of AK strain mice were unaffected. These data suggest that with acute exposures to MC, the immunogenetic resistance or susceptibility of a given mouse strain may have a more pronounced effect on immune depression and the severity of Tsp infection than does the Ah phenotype.
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PMID:The relative importance of Ah versus H-2 genotype on Trichinella resistance following exposure to 3-methylcholanthrene. 253 39

The courses of IgG and IgM antibody levels against adult worm and microfilarial antigen were determined in isogenetic cotton rats infected quantitatively with Litomosoides carinii. Against both antigens, IgG as well as IgM, antibody levels exceeded significantly those of noninfected animals, and the IgG levels were generally higher than the IgM levels. The total antibody production was depressed transiently 8 weeks p.i. by the appearance of microfilariae in the peripheral blood. A second transient depression occurred two weeks earlier against microfilarial antigen than it occurred against adult worm antigen. At 3 different times after the infection, the amount of adsorbed antibodies was assessed on adult worms and on microfilariae, which were isolated from blood and by a specially developed method from the internal organs. The percentual distribution of microfilariae in the different organs and blood changed during patency. In spleen, kidney, and lung a continuous increase was observed, whereas in heart and liver the percentage initially increased, and then decreased. The opposite course was seen in blood. Most antibodies adsorbed on the surface of microfilariae and adult worms belonged to the IgM class. Predominantly, the antibodies were detected on organ microfilariae, particularly on those in spleen and kidney, while blood microfilariae had lower amounts of bound antibodies. Furthermore, by complement fixation, no common antigens could be detected on the surface of host cells and the different L. carinii stages.
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PMID:Antibody response against Litomosoides carinii and the distribution of bound antibodies on microfilariae from the different internal organs of cotton rats. 290 63


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