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1.
Systematic dose- and time-response trials were first conducted to determine a treatment regimen with cambdendazole (CBZ, 2-[4′-thiazolyl]-5-isopropoxycarbonylaminobenzimidazole) that would be therapeutically effective against adult Trichinella spiralis in experimentally-infected mice. CBZ proved to be highly effective against adult Trichinella in a 3-day treatment course during the enterai phase of experimental trichinellosis. When treatment began 72 h after the mice were inoculated with parasites, the number of adult worms recovered from the host intestine was greatly reduced by twice-daily oral doses of CBZ at 25 mg kg?1 body wt. The efficacy of the divided daily oral dosage treatment regimen that was effective against adult T. spiralis during the enteral phase of infection was then tested during the parenteral phases of trichinellosis. Gavage administration of CBZ at 25 mg kg?1bis m die for 3 consecutive days during the invasive (days 14–16) and encystment (days 28–30) phases of infection significantly reduced (29 and 90 %, respectively) the number of larvae subsequently recovered from the host musculature on day 44 postinoculation.  相似文献   

2.
Trichinellosis is a serious disease with no satisfactory treatment. We aimed to assess the effect of myrrh (Commiphora molmol) and, for the first time, thyme (Thymus vulgaris L.) against enteral and encysted (parenteral) phases of Trichinella spiralis in mice compared with albendazole, and detect their effect on inducible nitric oxide synthase (iNOS) expression. Oral administration of 500 mg/kg of myrrh and thyme led to adult reduction (90.9%, 79.4%), while 1,000 mg/kg led to larvae reduction (79.6%, 71.3%), respectively. Administration of 50 mg/kg of albendazole resulted in adult and larvae reduction (94.2%, 90.9%). Positive immunostaining of inflammatory cells infiltrating intestinal mucosa and submucosa of all treated groups was detected. Myrrh-treated mice showed the highest iNOS expression followed by albendazole, then thyme. On the other hand, both myrrh and thyme-treated groups showed stronger iNOS expression of inflammatory cells infiltrating and surrounding encapsulated T. spiralis larvae than albendazole treated group. In conclusion, myrrh and thyme extracts are highly effective against both phases of T. spiralis and showed strong iNOS expressions, especially myrrh which could be a promising alternative drug. This experiment provides a basis for further exploration of this plant by isolation and retesting the active principles of both extracts against different stages of T. spiralis.  相似文献   

3.
Effects of environmental temperature on Trichinella spiralis-infected mice were studied. Groups of mice were acclimated to temperatures of 8–10 C, 20–25 C, and 36 C for a period of 5 days and then were exposed to 100 infective juveniles of T. spiralis via stomach intubation. After being maintained at the above temperatures for 5 days, they were examined for adult worms. Results indicate that mice maintained at 36 C tend to harbor significantly higher numbers of adults and that there is a direct relationship between temperature and worm number. Effects of mouse strain differences on these results were also examined. Of those strains tested, inbred Swiss albino mice proved to be superior hosts for T. spiralis.  相似文献   

4.
The immune response of mice to the nematode Trichinella spiral's was markedly altered when the infection was superimposed upon an existing infection with Nematospiroides dubius. The expulsion of a primary infection of T. spiralis was delayed in such mice, and the worms persisted for at least 4 weeks longer than they did in control mice. The degree to which expulsion was suppressed was related to the number of N. dubius present. It would appear that both adult and larval stages of N. dubius can exert a suppressive effect, since the expulsion of T. spiralis was affected within days of a super-imposed (i.e., larval) N. dubius infection. When adult N. dubius were removed from mice 4 days before infection with T. spiralis, the mice expelled the latter parasite within the normal time, indicating that recovery from the suppressive effects of concurrent infection occurred rapidly. Concurrent infection with N. dubius appeared to affect both the afferent and efferent arms of the immune response to T. spiralis, since sensitization by, and memory of, prior infection were impaired and the expression of acquired immunity was inferior to that of controls.  相似文献   

5.
Helminth infection induces production of a large amount of immunoglobulin E (IgE) to nonhelminth antigens. Although such “irrelevant” IgE is a major proportion of total IgE in the host, its biological significance remains unclear. Therefore, I examined protective activity against Trichinella spiralis in mice with high levels of IgE by repeated injections of anti-dansyl IgE monoclonal antibody or Nippostrongylus brasiliensis infection. Injected anti-dansyl IgE occupied IgE receptors on mast cells in naive mice. Protective activity against T. spiralis, determined with number of muscle larvae 5 weeks after infection, was impaired in mice treated with anti-dansyl IgE. The impaired protection was found in mice treated with anti-dansy IgE 7 and 14 days after infection, but not 21 and 28 days after infection, indicating that IgE-dependent protection operates at an early stage after infection. In the next experiments, mice were infected with N. brasiliensis 4 weeks before T. spiralis infection to obtain high levels of IgE. The protective activity against T. spiralis was decreased by N. brasiliensis infection. On the other hand, protection against T. spiralis was comparable in IgE-deficient SJA/9 mice and in anti-IgE-treated BALB/c mice with or without N. brasiliensis infection, suggesting that impairment of protection is dependent on IgE. These results indicate that the high levels of irrelevant IgE are beneficial for helminths and, alternatively, that anti-helminth IgE antibodies are protective for hosts. In addition, the impaired protection was found in IgE high-responder mice but not in low-responder mice, suggesting that protection against T. spiralis is controlled by IgE responsiveness in the host.  相似文献   

6.
Trichinosis is a parasitic zoonosis caused by the nematode Trichinella spiralis. Anthelmintics are used to eliminate intestinal adults as well as tissue-migrating and encysted larvae. This study aimed to investigate the effects of ivermectin and myrrh obtained from the aloe-gum resin of Commiphora molmol on experimental trichinosis. Ninety albino mice were orally infected with 300 T. spiralis larvae. Drugs were tested against adult worms at day 0 and day 5 and against encysted larvae on day 15 and day 35 post-infection (PI). Mature worms and encysted larvae were counted in addition to histopathological examination of muscle specimens. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), total protein, albumin, globulin, urea, and creatinine values were estimated. Significant reductions in mean worm numbers were detected in ivermectin treated mice at day 0 and day 5 PI achieving efficacies of 98.5% and 80.0%, while efficacies of myrrh in treated mice were 80.7% and 51.5%, respectively. At days 15 and 35 post-infection, ivermectin induced significant reduction in encysted larval counts achieving efficacies of 76.5% and 54.0%, respectively, while myrrh efficacies were 76.6% and 35.0%, respectively. AST, ALT, urea, and creatinine levels were reduced, while total proteins were increased in response to both treatments compared to their values in the infected non-treated mice. Ivermectin use for controlling T. spiralis could be continued. Myrrh was effective and could be a promising drug against the Egyptian strains of T. spiralis with results nearly comparable to ivermectin.  相似文献   

7.
Trichinellosis is a serious food-borne parasitic disease with serious community health effects, mainly causing muscle damage with no recent approved treatment. This study aimed to assess the therapeutic effect of gallic acid (GA) as a potent antioxidant against the encysted phase of Trichinella spiralis in male (BALB/c) mice alone or combined with albendazole (ALB) and to detect their synergistic effects on the histology and ultrastructure of skeletal and cardiac muscles and some biochemical blood analyses. Forty male mice were randomly divided into five groups (8 mice/group). 1st group: the negative control received only distilled water, 2nd group: the positive control (infected control group without treatment), 3rd group: infected group plus treatment with ALB (50 mg Kg−1 orally), and 4th group: infected group and then treated with GA (30 mg Kg−1 orally) and finally 5th infected group treated with a combination of both ALB and GA. Aspartate and Alanine aminotransferase, Lactate dehydrogenase, alkaline phosphatase, C-reactive protein, Interleukin-4 and Creatine kinase were used as biochemical markers of hepatic and cardiac toxicity and inflammation. Malondialdehyde level, catalase, superoxide dismutase, and glutathione peroxidase were evaluated in heart tissue homogenates beside histological and ultra-structural examination of heart and skeletal muscles beside parasitological analyses. Results showed that the reduction % of Trichinella sp. larvae g−1 in muscles of the group treated with the combination of GA and ALB showed overall reduction percentages. Oral administration of 30 mg kg1 of GA led to infection reduction of T. spiralis than ALB treated group. Both administration of ALB beside GA showed the best treatment group that resulted in high infection reduction besides amelioration of both biochemical markers and restoration of histological and ultrastructures to normal state. In conclusion, GA is highly effective against T. spiralis which could be a promising alternative antioxidant drug and the GA effect was higher in the case of combination with ALB. This experiment provides a basis for further exploration of potent activities of other antioxidants against different phases of T. spiralis and the reduction of any health hazards prospectively.  相似文献   

8.
Adoptive transfer of immunity with day 8 mesenteric lymph node cells (MLNC) taken from NIH mice after a chemically abbreviated infection of 3 days duration was as effective as transfer with cells taken from mice which had received an uninterrupted infection. Using a surgical transplantation technique it was demonstrated that adult T. spiralis were not capable of stimulating cells effective upon adoptive transfer. The potent immunogenicity of the early stages of infection was emphasized by data showing that very low numbers of muscle larvae were efficient in stimulating effective mediator cells. Neither the time at which MLNC were taken for transfer after transplantation of adult worms nor the age of adult worms transplanted affected the failure of this life cycle stage to stimulate cells capable of mediating worm expulsion. It is proposed that expulsion of T. spiralis from the gut may be achieved by more than one effector mechanism, and that early and late intestinal stages stimulate these mechanisms differentially.  相似文献   

9.
The immune correlate of host resistance induced by reinfection of Trichinella spiralis remains unclear. In this study, we investigated immune correlates between the resistance and serum IgG antibody level, CD23+ IgM+ B cells, and eosinophil responses induced by T. spiralis reinfection. Mice were primarily infected with 10 or 100 T. spiralis larvae (10 TS, 100 TS), respectively, and after 4 weeks, they were challenge infected with 100 T. spiralis larvae (10–100 TS, 100-100 TS). Upon challenge infections, 10–100 TS mice induced significantly higher levels of T. spiralis-specific total IgG antibody responses in sera and antibody secreting cell responses in spleens compared to 100-100 TS mice, resulting in significantly reduced worm burdens in 10–100 TS mice (60% and 70% reductions for adult and larvae, respectively). Higher levels of eosinophils were found in mice primarily infected with 10 TS compared to those of 100 TS at week 8 upon challenge. CD23+ IgM+ B cells were found to be increased significantly in mice primarily infected with 10 TS. These results indicate that primary infection of 10 larvae of T. spiralis, rather than 100 larvae, induces significant resistance against reinfection which closely correlated with T. spiralis-specific IgG, eosinophil, and CD23+ IgM+ B cell responses.  相似文献   

10.
Trypanosoma musculi infections were given to mice of different strains before, at the same time, and after an infection with 400 Trichinella spiralis. Examined parameters of the host response to T. spiralis were worm rejection, antifecundity responses, development of immunological memory, and muscle larvae burden. After dual infection, each mouse strain showed characteristic effects on resistance to T. spiralis. This was due to a dynamic interaction between the genes controlling rejection of T. spiralis and those influencing T. musculi growth. C3H mice develop high trypanosome parasitemias. This impairs worm expulsion and the development of memory to T. spiralis when Trypanosoma infections take place on the same day or 7 days before. The C57B1/6 mouse develops low parasitemias and T. musculi infections on the same day, or 7 days before T. spiralis, delaying worm rejection only slightly despite the overall weak capacity of B6 mice to expel worms. NFR-strain mice are strong responders to T. spiralis and also develop low parasitemias. Trypanosome infections on the same day, or after T. spiralis, produce a delay in worm rejection; the former is comparable to C3H mice. However, NFR mice alone showed enhanced rejection of worm when T. musculi infections preceded T. spiralis by 7 days. An unusual feature of C3H mice was that T. musculi infections 7 days before T. spiralis increased antifecundity responses at the same time that worm expulsion was inhibited. Trypanosome infections can therefore modulate distinct antihelminth immune responses in different directions simultaneously. The different outcomes of dual infections compared with single infections provides another selective mechanism by which genetic polymorphisms can be established and maintained in the vertebrate host.  相似文献   

11.
The therapeutic effect of allopurinol was studied in an experimental Trypanosoma cruzi infection (Chagas disease) in outbred IVIC-NMRI and inbred C57B1/6J mice intraperitoneally inoculated with the parasites 2–6 days before drug treatment. Allopurinol protected against T. cruzi infection. This effect was evidenced by highly significant reductions in both parasitemias and mortality rates and increased survival time in allopurinol-treated animals compared with untreated infected mice. Allopurinol protected effectively when administered in 10 daily doses of 32–64 mg/kg body wt/day injected intraperitoneally. Using direct methods, parasitemia remained undetectable for at least 310 days. An indirect method, subinoculation to susceptible mice, showed a few circulating trypanosomes which decreased greatly in number after a second schedule of allopurinol treatment; finally no trypanosomes were detectable 275 days after treatment initiation. Allopurinol also induced a strong trypanostatic effect when tested in vitro on five different Trypanosoma cruzi strains (optimal inhibitory concentration: 3 μg/ml). These results suggest that allopurinol protects mice with acute Chagas infection by a direct trypanostatic effect. The low toxicity of this drug suggests its use in more chronic experimental Chagas infections.  相似文献   

12.
The intestinal phase of Trichinella spiralis and of Trichinella sp. isolated in the Arctic were compared in experimental animals. Reproductive capacity, pathogenicity, distribution, and persistence of adults in the small intestine, morphological measurements, and release of newborn larvae in vitro were examined. Numerous passages of 40 days each for T. spiralis and the Trichinella sp. isolate in mice did not affect reproductive capacity, distribution of adults in the small intestine, and size of worms. Reproductive capacity index for T. spiralis, I = 151.27 ± 27.30 was significantly higher compared to the Trichinella sp. isolate index, I = 63.46 ± 19.34. The Trichinella sp. isolate was more pathogenic to mice and wild rodents compared to T. spiralis during the intestinal phase. Both parasites were located in the anterior part of the small intestine but the position of T. spiralis adults (P = 17.08) differed from position of the Trichinella sp. isolate adults (P = 23.46) in the small intestine. Intestinal phase of T. spiralis was longer (20 days) compared to the Trichinella sp. isolate (15 days) but sex ratios (:♂) were similar for both parasites. T. spiralis females released significantly higher numbers of larvae in vitro/24 hr compared to the Trichinella sp. isolate. Release of larvae was continuous during the intestinal phase and the average fecundity for T. spiralis was 335 larvae/female and for the Trichinella sp. isolate 114 larvae/female. Adults of T. spiralis and the Trichinella sp. isolate were morphologically indistinguishable and did not differ in size. A comparative index for the intestinal phase is proposed for comparison of any Trichinella spp. isolates and standard T. spiralis.  相似文献   

13.
The effects of concurrent infection with Toxoplasma gondii on the host-parasite relationship in trichinosis were studied. Infected mice showed a delay in expulsion of Trichinella spiralis adults from the gut. Persisting adult female worms were fecund but the numbers of larvae recovered from the muscles were not increased. Increased resistance to the systemic phase of trichinosis was shown by reduced numbers of muscle larvae after intravenous injection of newborn larvae in animals with toxoplasmosis as compared with control mice. There were no differences in small bowel pathology of trichinous mice with and without toxoplasmosis but inflammation around muscle cysts of T. spiralis was reduced in mice with toxoplasmosis. The eosinophilia which normally develops in mice with trichinosis was suppressed by concurrent toxoplasmosis. Trichinella infection did not alter the numbers of T. gondii cysts recovered from the brain 4 weeks after infection. It is suggested that the delay in expulsion of adult worms, decrease in muscle inflammation around T. spiralis cysts, and inhibition of eosinophilia result from immune suppression, while the reduction in numbers of muscle larvae after intravenous injection of newborn larvae reflects enhanced nonspecific resistance to infection in toxoplasmosis.  相似文献   

14.
Three nitroimidazole compounds were tested for trypanocidal activity against early (3-day) T. brucei TREU 667 infections. Compound 1 (1-methyl-2-carbamoyl-oxy-methyl-5-nitroimidazole) at both 5 and 20 mg/kg given as four daily doses was ineffective, while Compound 2 (3-(1-methyl-5-nitroimidazole-2-yl)-3α, 4,5,6,7, 7α-hexahydro-1, 2-benz-isoxazole) at 4 × 80 mg/kg and Compound 3 (3-(1-methyl-5-nitroimidazole-2-yl)-4, 5-hexamethylene-Δ2-isoxazoline) at 4 × 20 mg/kg both elicited a permanent cure. When tested against late (21-day) infections of T. brucei 667 neither Compound 2 nor Compound 3 given singly, or in various combinations was effective in that parasitaemias returned rapidly in nearly all mice.When the trypanocidal drug ‘Berenil’ was administered followed by the Compound 3, the majority of the mice with a 21-day infection of T. brucei TREU 667 or T. brucei LUMP 1001 were cured permanently. When ‘Berenil’ alone was used the mice usually relapsed within a few weeks of treatment. The isolate used affected the outcome of the treatment. Higher dosages of ‘Berenil’ followed by Compound 3 were required to cure infections with T. brucei LUMP 1001 than with T. brucei TREU 667.The importance of these findings in the treatment of human sleeping sickness with central nervous system involvement is discussed.  相似文献   

15.
Male albino mice were infected orally with 400 ± 10 excysted Trichinella spiralis larvae. Skeletal muscle resting membrane potentials were recorded from the tibialis anterior muscles of infected and uninfected mice on the following days postinfection (PI): 1–15, 18, 20, 24, 28, 30–60 (at 5-day intervals), 90, 120, 150, and 180. The membrane potentials were significantly (P < 0.05) lower in infected muscle (82 vs 85 mV) on Day 30 PI. On Days 60, 90, 120, 150, and 180 PI the mean membrane potential in infected muscle (62 mV) was about 23 mV lower than the mean for uninfected muscle (85 mV) and this difference was highly significant (P < 0.001). These findings are discussed in relationship to other physiological alterations known to occur in skeletal muscles infected with T. spiralis larvae.  相似文献   

16.
The effects of concurrent primary infection of the rat with Eimeria nieschulzi and Trichinella spiralis on the number of oocysts of E. nieschulzi shed by the host and on the number, distribution, and fecundity of adult T. spiralis were analyzed. When rats were initially infected with E. nieschulzi followed 9 days later by infection with T. spiralis there occurred a significant decrease in the total numbers of adult worms in the small intestine, a significant shift in the position of these worms along the length of the small gut, a decrease in the fecundity of adult female worms, and a decrease in muscle parasitism when compared with rats infected with T. spiralis alone. When rats were initially infected with T. spiralis, followed 9 days later by infection with E. nieschulzi, there occurred a significant decrease in the numbers of oocysts shed over 24 hr on Days 7, 9, and 11 postinfection below that seen with rats infected only with Eimeria. These changes are discussed in terms of the enteropathophysiologic lesions and enteric inflammation known to occur during infections with these two parasites.  相似文献   

17.
Trichinellosis is one of the most important food-borne parasitic zoonoses throughout the world. Because infected pigs are the major source of human infections, and China is becoming the largest international producer of pork, the development of a transmission-blocking vaccine to prevent swine from being infected is urgently needed for trichinellosis control in China. Our previous studies have demonstrated that specific Trichinella spiralis paramyosin (Ts-Pmy) and Ts-87 antigen could provide protective immunity against T. spiralis infection in immunized mice. Certain protective epitopes of Ts-Pmy and Ts-87 antigen have been identified. To identify more Ts-Pmy protective epitopes, a new monoclonal antibody, termed 8F12, was produced against the N-terminus of Ts-Pmy. This antibody elicited significant protective immunity in mice against T. spiralis infection by passive transfer and was subsequently used to screen a random phage display peptide library to identify recognized epitopes. Seven distinct positive phage clones were identified and their displayed peptides were sequenced. Synthesized epitope peptides conjugated to keyhole limpet hemocyanin were used to immunize mice, four of which exhibited larval reduction (from 18.7% to 26.3%, respectively) in vaccinated mice in comparison to the KLH control. To increase more effective protection, the epitope 8F7 that was found to induce the highest protection in this study was combined with two other previously identified epitopes (YX1 from Ts-Pmy and M7 from Ts-87) to formulate a multi-epitope vaccine. Mice immunized with this multi-epitope vaccine experienced a 35.0% reduction in muscle larvae burden after being challenged with T. spiralis larvae. This protection is significantly higher than that induced by individual-epitope peptides and is associated with high levels of subclasses IgG and IgG1. These results showed that a multi-epitope vaccine induced better protective immunity than an individual epitope and provided a feasible approach for developing a safer and more effective vaccine against trichinellosis.  相似文献   

18.
A full-length cDNA encoding Trichinella spiralis paramyosin (Ts-Pmy) was cloned by immunoscreening a cDNA library of the adult T. spiralis worm. Ts-Pmy cDNA consists of 2655 bp that encode 885 amino acids. The recombinant protein (rTs-Pmy) was expressed and purified by Ni-affinity chromatography. Western blot analysis showed that rTs-Pmy could be recognized by sera from T. spiralis-infected humans, swine, rabbits, and mice. Immunolocalization demonstrated that Ts-Pmy was abundant on the surface of T. spiralis larvae. BALB/c mice vaccinated with rTs-Pmy demonstrated 36.2% reduction in muscle larvae burden following T. spiralis larvae challenge. Vaccination of the mice with rTs-Pmy resulted in a high level of specific anti-Ts-Pmy IgG antibodies and generated a Th1/Th2 mixed type of immune response, with Th2 predominant. These studies showed that rTs-Pmy induced protective immunity in mice and could be considered as a potential vaccine candidate for trichinellosis.  相似文献   

19.
The effects of BCG (Bacillus Calmette-Guérin, i.e., attenuated Mycobacterium bovis) on the host-parasite relationship in murine trichinosis were examined. A total of 2 × 107 colony forming units of BCG given iv 1 week prior to Trichinella spiralis infection delayed the expulsion of adult worms from the gut. The suppression of adult worm elimination was proportional to the dose of BCG given. This finding was associated with a reduction in the degree of partial villous atrophy induced in the small bowel by T. spiralis. Adult female worms were fecund when they were examined 1, 2, and 3 weeks after infection of mice with T. spiralis. Despite the prolongation of fecund adult worms in the gut, there were no significant differences in muscle larval counts 4 and 6 weeks after infection. When newborn larvae were cultivated in vitro and injected iv, there was a significant 25% reduction in larval numbers recovered from the muscles of BCG-treated mice 4 weeks later. The administration of BCG had no effect on the inflammatory reaction around larvae in the muscles 4 and 6 weeks after infection. It is concluded that BCG alters the host-parasite relationship producing retention of adult worms in the gut, reduction in the severity of partial villous atrophy, and increased nonspecific resistance to the systemic larval phase of this parasite.  相似文献   

20.
Our previous studies showed that immunization with recombinant paramyosin from Trichinella spiralis (rTs-Pmy) formulated with Freund’s adjuvant significantly reduced larval burden in mice after T. spiralis larval challenge. Since Freund’s adjuvant is toxic and not a suitable adjuvant for clinical vaccine trials, we evaluated the ability of the adjuvants Montanide ISA206 and ISA720 to stimulate immune responses during rTs-Pmy immunization and to enhance protective immunity. The results revealed that immunization of BALB/c mice with rTs-Pmy formulated with either ISA206 or ISA720 triggered Th1 and Th2 immune responses similar to those produced by the conventional Freund’s adjuvant formulation and also provided a similar level of protection against T. spiralis larval challenge. This indicates that the recombinant Ts-Pmy formulated with Montanide ISA206 or ISA720 may be an effective and safety vaccine strategy for trichinellosis.  相似文献   

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