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1.
The anti‐infectious activity of synbiotics against methicillin‐resistant Staphylococcus aureus (MRSA) infection was evaluated using a novel lethal mouse model. Groups of 12 mice treated with multiple antibiotics were infected orally with a clinical isolate of MRSA at an inoculum of 108 CFU on day 7 after starting the antibiotics. A dose of 400 mg/kg 5‐fluorouracil (5‐FU) was injected intraperitoneally on day 7 after the infection. A dose of 108 CFU Bifidobacterium breve strain Yakult and 10 mg of galactooligosaccharides (GOS) were given orally to mice daily with the antibiotic treatment until day 28. The intestinal population levels of MRSA in the mice on multiple antibiotics were maintained stably at 108 CFU/g of intestinal contents after oral MRSA infection and the subsequent 5‐FU treatment killed all the mice in the group within 14 days. B. breve administration saved most of the mice, but the synbiotic treatment saved all of the mice from lethal MRSA infection. The synbiotic treatment was effective for the treatment of intestinal infection caused by four MRSA strains with different toxin productions. There was a large difference among the six Bifidobacteria strains that were naturally resistant to the antibacterial drugs used. B. breve in combination with GOS is demonstrated to have valuable preventive and curative effects against even fatal MRSA infections.  相似文献   

2.
AIM: To establish whether activation of adenosine type-3 receptors (A3Rs) and inhibition of interleukin-1β-induced inflammation is beneficial in combination with antibiotic therapy to increase survival of mice challenged with anthrax spores.METHODS: DBA/2 mice were challenged with Bacillus anthracis spores of the toxigenic Sterne strain 43F2. Survival of animals was monitored for 15 d. Ciprofloxacin treatment (50 mg/kg, once daily, intraperitoneally) was initiated at day +1 simultaneously with the administration of inhibitors, and continued for 10 d. Two doses (2.5 mg/kg and 12.5 mg/kg) of acetyl-tyrosyl-valyl-alanyl-aspartyl-chloromethylketone (YVAD) and three doses (0.05, 0.15 and 0.3 mg/kg) of 1-[2-Chloro-6-[[(3-iodophenyl) methyl]amino]-9H-purin-9-yl]-1-deoxy-N-methyl-β-D- ribofuranuronamide (Cl-IB-MECA) were tested. Animals received YVAD on days 1-4, and Cl-IB-MECA on days 1-10 once daily, subcutaneously. Human lung epithelial cells in culture were challenged with spores or edema toxin and the effects of IB-MECA on phosphorylation of AKT and generation of cAMP were tested.RESULTS: We showed that the outcome of antibiotic treatment in a murine anthrax model could be substantially improved by co-administration of the caspase-1/4 inhibitor YVAD and the A3R agonist Cl-IB-MECA. Combination treatment with these substances and ciprofloxacin resulted in up to 90% synergistic protection. All untreated mice died, and antibiotic alone protected only 30% of animals. We conclude that both substances target the aberrant host signaling that underpins anthrax mortality.CONCLUSION: Our findings suggest new possibilities for combination therapy of anthrax with antibiotics, A3R agonists and caspase-1 inhibitors.  相似文献   

3.
Mice orally infected with enterohaemorrhagic Escherichia coli (EHEC) O157:H7 were used to evaluate the activity of bovine lactoferrin (bLF) and the synthetic peptide LFchimera. Groups of BALB/c mice inoculated intragastrically with EHEC O157:H7 showed chronic intestinal infection with the pathogen that persisted over 6 days and resulted in a high mortality rate (90%). LFchimera and kanamycin significantly decreased (40%) this mortality rate (P = 0.028). On the other hand, although mice administered with bLF showed an important reduction in mortality (50%), this was not statistically significant (P = 0.070). In infected and untreated mice, severe tubular necrosis, glomerular lesions, and moderate intratubular hyaline casts were found in the kidney. However, in the bLF and LFchimera groups we found a reduction in the damage and a substantial decrease in the bacterial concentration excreted in feces 48 h after infection. Furthermore, sepsis caused by EHEC was reduced by the treatments, evidenced by the fact that bacteria were not detected in the kidney or liver 72 h after infection. The results suggest the bLF and LFchimera could have potential as therapeutics in EHEC infections.  相似文献   

4.
We studied the synergistic effects of Japanese green tea extract (JGTE) and levofloxacin (LVFX) against enterohemorrhagic Escherichia coli (EHEC) infection in a gnotobiotic mouse model. Mice fed on JGTE conferred a significant degree of protection against an oral challenge with EHEC. Complete elimination of the bacteria from the mice, was however, difficult. The combination of JGTE and LVFX increased the survival rate and reduced damage to target organs. Thus, dietary supplementation with JGTE improved the therapeutic effects of antibiotic treatment. Received: 28 July 2000 / Accepted: 19 September 2000  相似文献   

5.
The aim of this study is to evaluate the therapeutic effect of the antimicrobial agents, fosfomycin (FOM), minocycline (MINO), kanamycin (KM) and norfloxacin (NFLX) in the enterohemorrhagic Escherichia coli (EHEC) infected mouse model which we established previously (Infect. Immun. 62 (1994) 3447-3453). Each of the antimicrobial agents, 1/16 LD(50), was given to the mice per os (p.o. ) or intraperitoneally (i.p.) for 3 days after bacterial inoculation and then we observed their mortality rate for 2 weeks. The mortality rates of mice administered with MINO (p.o./i.p.), KM (p.o.), NFLX (p. o./i.p.) were significantly lower than those of the control group. Both the bacterial number and VT2c level in the feces of the FOM group were lower than those of the NFLX group on day 1, but reversed on day 3. In an in vitro experiment, each of the four drugs in combination with mitomycin C (MMC) caused a more significant decrease in the bacterial number than sole MMC, and they consequently indicated the suppressive effect on the release of VT2c.  相似文献   

6.
Toxoplasma gondii is an important apicomplexan parasite of humans and other warm-blooded animals. Ponazuril is a triazine anticoccidial recently approved for use in horses in the United States. We determined that ponazuril significantly inhibited T. gondii tachyzoite production (P < 0.05) at 5.0, 1.0, or 0.1 microg/ml in African green monkey kidney cells. We used outbred female CD-1 mice to determine the efficacy of ponazuril in preventing and treating acute toxoplasmosis. Each mouse was subcutaneously infected with 1,000 tachyzoites of the RH strain of T. gondii. Mice were weighed daily, and ponazuril was administered orally in a suspension. Mice given 10 or 20 mg/kg body weight ponazuril 1 day before infection and then daily for 10 days were completely protected against acute toxoplasmosis. Relapse did not occur after prophylactic treatments were stopped. Toxoplasma gondii DNA could not be detected in the brains of these mice using polymerase chain reaction (PCR). One hundred percent of mice treated with 10 or 20 mg/kg ponazuril at 3 days after infection and then daily for 10 days were protected from fatal toxoplasmosis. Sixty percent of mice treated with 10 mg/kg ponazuril at 6 days after infection and 100% of mice treated with 20 mg/kg or 50 mg ponazuril 6 days after infection and then daily for 10 days were protected from fatal toxoplasmosis. Relapse did not occur after treatments were stopped. Toxoplasma gondii DNA was detected in the brains of some, but not all, of these mice using PCR. The results demonstrate that ponazuril is effective in preventing and treating toxoplasmosis in mice. It should be further investigated as a safe and effective treatment for this disease in animals.  相似文献   

7.
The radioprotective effect of the hydroalcoholic extract of ginger rhizome, Zingiber officinale (ZOE), was studied. Mice were given 10 mg/kg ZOE intraperitoneally once daily for five consecutive days before exposure to 6-12 Gy of gamma radiation and were monitored daily up to 30 days postirradiation for the development of symptoms of radiation sickness and mortality. Pretreatment of mice with ZOE reduced the severity of radiation sickness and the mortality at all doses. The ZOE treatment protected mice from GI syndrome as well as bone marrow syndrome. The dose reduction factor for ZOE was found to be 1.15. The optimum protective dose of 10 mg/kg ZOE was 1/50 of the LD50 (500 mg/kg). Irradiation of the animals resulted in a dose-dependent elevation in the lipid peroxidation and depletion of GSH on day 31 postirradiation; both effects were lessened by pretreatment with ZOE. ZOE also had a dose-dependent antimicrobial activity against Pseudomonas aeruginosa, Salmonella typhimurium, Escherichia coli and Candida albicans.  相似文献   

8.
The susceptibility of a fourth generation Ouh strain (Paranapanema Valley, S?o Paulo, Brazil) of Schistosoma mansoni to oxamniquine (OXA) and praziquantel (PZQ) was studied. Ten groups of 13 female albino mice each were infected with 70 cercariae per animal. These mice were medicated orally on the 50th day after infection. Five groups were given OXA doses of 0, 100, 200, 300 and 400 mg/kg (single doses) and the rest were treated with PZQ doses of 0, 100, 200, and 250 mg/kg/5 days. Each group was sub-divided: 8 animals underwent perfusion after 15 days treatment, 5 mice followed up for oviposition and their feces were tested every 15 days for miracidia hatching. The efficacy of the OXA doses of 100 and 200 mg/kg was 66% and 91.4%, respectively and for the 100 mg/kg PZQ dose it was 90.1%. The follow-up groups with 100 and 200 mg/kg of OXA and PZQ, 100 and 150 mg/kg, showed that they re-established the oviposition after a period of 60 to 75 days of treatment. The ED50 was 69.6 mg/kg OXA and 39.4 mg/kg PZQ. The results show the tolerance of the Ouh strain to a dose of 100 mg with both drugs and they appoint the need for a dose review during the follow up of the oviposition and in monitoring phenomena in the field.  相似文献   

9.
厌氧菌与兼性菌的混合感染及其治疗是目前临床上感染性疾病和抗生素治疗研究领域内的重要问题之一,本文对小鼠混合感染的动物模型甲硝哒唑与庆大霉素治疗结果显示:当脆弱类杆菌10~9CFU/ml大肠杆菌10~8CFU/ml混合感染小鼠6h后,单用甲硝哒唑治疗死亡率为9/10,脓肿率为1/10;单用庆大霉素组死亡率2/10,脓肿率为10/10;两药联用死亡率为2/10,无脓肿发生。两药联用的治疗比较:即时组基本同6h组,而12h开始治疗组死亡率达6/10。脓肿率4/6。提示应及早联合用药以阻断细菌的协同致病作用,控制感染。  相似文献   

10.
Chemotherapeutic activity of 3-(5-nitrofuryl)-7-(5-nitrofurfuryliden)-3, 3a, 4, 5, 6, 7-hexahydro-2H-indazol (compound 26) was studied on albino mice with experimental staphylococcal infection. The animals were contaminated intraperitoneally. The results of culture of the specimens of the organs of the mice killed within various terms and the values of the spleen bacterial index served as the criteria of the effectiveness. Compound 26 was administered in doses of 20, 10 and 5 mg/kg once a day for 3 days. The treatment was started simultaneously with or 24 hours after the contamination. The results showed that compound 26 in a dose 20 mg/kg (0.4 mg/mouse) possessed high chemotherapeutic activity in experimental staphylococcal infection of albino mice and could be recommended for a thorough study as a potential agent for chemotherapy of staphylococcal infection.  相似文献   

11.
The effect of Z-100, an immunomodulatory arabinomannan extracted fromMycobacterium tuberculosis, on cecal ligation and puncture (CLP)-induced sepsis in mice bearing Meth-A fibrosarcoma was investigated. When normal BALB/c mice were subjected to the CLP procedure, their mortality rate was 17%. On the other hand, an increased mortality was observed in tumor-bearing mice subjected to CLP 10 days after tumor inoculation, and then all mice died when tumor- bearing mice were subjected to CLP 20 days after tumor inoculation. However, the increased percent mortality was decreased by 50% when these mice were injected intraperitoneally with a 10 mg/kg dose of Z-100. When splenocytes (5 × 107 cells), obtained from Meth-A tumor-bearing mice 20 days after tumor inoculation, were transferred intravenously to normal mice (recipient mice), mortality of these recipient mice were increased by 62% as compared with that of the control (22%). However, no increased mortality (25%) was observed in recipient mice which were transferred with splenocytes from tumor-bearing mice injected intraperitoneally with Z-100 (10 mg/kg). In addition, suppressor cell activity was demonstrated in splenocytes from Meth-A tumor-bearing mice at 20 days after tumor inoculation using one-way mixed lymphocyte reaction. However, the suppressor cell activity was significantly decreased by the intraperitoneal administration of a 10 mg/kg dose of Z-100 (p<0.01). The increase of mortality in recipient mice by adoptive transfer of mononuclear cells (MNCs) from tumor-bearing mice was not detected when these MNCs were treated with anti-Thy 1.2 monoclonal antibody (mAb), anti-Lyt 2.2 mAb or anti-CD11b mAb, but an increase was seen with anti-Lyt 1.2 mAb or anti-immunoglobulin antiserum treated MNCs. These results suggest that the suppressor cells affect the mortality of CLP-induced sepsis and Z-100 may have a therapeutic activity against opportunistic infections in immunocompromised hosts through the regulation of suppressor T-cells.  相似文献   

12.
We tested the effects of the aqueous extract of Petiveria alliacea leaves on acute and sub-chronic toxicity, hematocrit and blood glucose level and intestinal motility of male albino NGP mice of 20 to 25 g mean weight. Treatments were in all cases doses of 1,000 and 2,000 mg/kg animal weight and a control treatment with 0.5 ml distilled water, using 10 animals per treatment and administered orally every day (5 days per week). Experimental periods were 18 and 70 days for acute and sub chronic toxicity, respectively. No mortality nor any toxicity signs could be observed. A slight but significant increase in the glucose levels during the first three weeks was observed with the 1,000 mg/kg dose but not for the higher 2,000 mg/kg dose. After administering the doses once after a starving period of six hours, no significant differences in intestinal motility could be found.  相似文献   

13.
P T Wong  W L Teo 《Jikken dobutsu》1992,41(2):247-249
Twenty percent of the Swiss albino mice administered with a single dose (60 mg/kg) of oxazepam dissolved in dimethyl sulphoxide (DMSO) died within 7 days. Similarly high mortality rate (37%) was observed in diazepam sensitive mice derived from a Swiss albino stock. In contrast, zero mortality was observed in Swiss albino mice administered with DMSO or diazepam (35 mg/kg). Mortality at 60 mg/kg diazepam was only 10%. The high mortality caused by oxazepam in Swiss albino mice seemed to be strain-related as only 7% mortality was observed with identically treated BALB/c mice. Since DMSO is the only convenient vehicle for the administration of oxazepam by injection, it is suggested that a suitable strain must be selected for experimentation in order to avoid unnecessary loss of animals.  相似文献   

14.
Withania somnifera is a medicinal plant used in the treatment of a variety of ailments in the Ayurvedic system. Alcoholic extract of the root of the plant was injected(ip) at daily doses of 200 to 1000 mg/kg body wt for 15 days starting from 24 hr after intradermal inoculation of 5 x 10(5) cells of S-180 in BALB/c mice. Solid tumor growth was monitored for 100 days. Doses of 400 mg/kg and above produced complete regression of tumor after an initial growth, the percentage of complete response (CR) increasing with increasing drug dose. A 55% CR was obtained at 1000 mg/kg drug administration, but this dose also produced some mortality among the animals. A significant increase in the volume doubling time and growth delay was seen when the drug dose was increased from 500 to 750 mg/kg body wt, but further increase in drug dose to 1000 mg/kg did not produce any significant increase in these responses. Cumulative doses of 7.5 to 10 g at daily doses of 500 or 750 mg/kg seems to produce a good response in this tumor.  相似文献   

15.
To determine whether treatment with melatonin (MLT) improves the efficiency of immunization against Venezuelan equine encephalomyelitis (VEE) virus, mice were vaccinated with TC-83 VEE virus and treated daily with MLT (1 or 5 mg/kg) starting 3 days before immunization, until 10 days after. IgM antibody titers were determined at days 7, 14, and 21 post-immunization. IL-10 levels were assayed at day 14 postvaccination. Treatment with MLT increased antibody titers 14 days after the immunization. IL-10 levels also increased with MLT treatment (1 and 5 mg/kg). Mice were challenged with live VEE virus at day 21 postimmunization, and viral titers were plaque assayed in chicken embryo fibroblasts 4 days after the infection. Following this challenge brain virus levels were significantly reduced. The results suggest that MLT treatment enhances the efficiency of mice immunization against VEE virus.  相似文献   

16.
Gastric leiomyosarcoma is a recalcitrant cancer and the chemotherapy strategy is controversial. The present study used a patient-derived orthotopic xenograft (PDOX) nude mouse model of gastric leiomyosarcoma to identify an effective therapeutic regimen to develop individualized precision medicine for this disease. The gastric leiomyosarcoma obtained from a patient was first grown in transgenic nude mice ubiquitously expressing red fluorescent protein (RFP) to stably label the tumor stroma. The RFP-expressing tumor was then passaged orthotopically in the gastric wall of non-transgenic nude mice to establish an imageable PDOX (iPDOX) model. The bright fluorescent tumor was readily imaged over time to determine drug efficacy. Four weeks after implantation, 70 PDOX nude mice were divided into 7 groups: control without treatment (n = 10); doxorubicin (DOX) (2.4 mg/kg, intraperitoneally (i.p.), once a week for 2 weeks, n = 10); gemcitabine (GEM)/ docetaxel (DOC) (GEM: 100 mg/kg, DOC: 20 mg/kg, i.p., once a week for 2 weeks, n = 10); cyclophosphamide (CPA) (140 mg/kg, i.p., once a week for 2 weeks, n = 10); temozolomide (TEM) (25 mg/kg, orally, daily for 14 consecutive days, n = 10); yondelis (YON) (0.15 mg/kg, i.v., once a week for 2 weeks, n = 10); pazopanib (PAZ) (100 mg/kg, orally, daily for 14 consecutive days, n = 10). On day 14 from initiation of treatment, all treatments except PAZ significantly inhibited tumor growth compared with untreated control (DOX: p < 0.01, GEM/DOC: p < 0.01, CPA: p < 0.01, TEM: p < 0.01, YON: p < 0.01) on day 14 after initiation. In addition, only GEM/DOC was more significantly effective than DOX (p < 0.05). GEM/DOC could regress the leimyosarcoma in the PDOX model and has important clinical potential for precision individual treatment of leiomyosarcoma patients.  相似文献   

17.
Itoh S  Katoh M  Furuhama K 《Mutation research》2002,520(1-2):133-139
The skin micronucleus test combined with irradiation due to a sunlight simulator having a spectrum almost identical to solar irradiation was used as a novel in vivo testing method for detecting or comparing the photochemical chromosome damage of quinolone antibacterial agents (quinolones). Eight-week-old male SKH1 hairless mice were orally administered once lomefloxacin (LFLX), a strong in vitro photochemical clastogen, at 25 or 50 mg/kg, followed by light irradiation at 7.9-9.4J/cm2 of ultraviolet A (UVA). Animals were killed on Days 2, 3, 4, 5 or 8 (the dosing day was designated as Day 1), and the incidence of micronucleus in the epidermis was determined. As results, LFLX at either dose caused significant increases in the micronucleus frequency, which peaked on Day 4. These changes tended to return to the control level on Day 8. Then, the micronucleus induction potential of the quinolone derivatives levofloxacin (LVFX) and clinafloxacin (CLFX) at 10, 20 or 40 mg/kg was assessed on Day 4 under the same experimental conditions as for LFLX. Although LVFX was negative even at 40 mg/kg, CFLX dose-dependently induced significant increases in micronucleus frequency at all doses. The correlation of magnitude among the three quinolones in the skin micronucleus test with light irradiation was similar to that in our previous in vitro photochemical clastogenicity study. No significant increase in micronucleus frequency was observed in any of three quinolones employed without light irradiation. In conclusion, the experimental method presented here would be a useful tool for detecting in vivo photochemical chromosome damage and for research on photochemical carcinogenesis of chemicals.  相似文献   

18.
This study was designed to investigate whether cocaine can exacerbate viral myocarditis and increase its incidence. Recent clinical evidence suggests that cocaine abuse increases the incidence of myocarditis. However, it has not been directly demonstrated that cocaine exposure enhances murine myocarditis. BALB/c mice were divided into eight groups: saline control, encephalomyocarditis virus (EMCV), 10 mg/kg cocaine (Coc-10), 30 mg/kg cocaine (Coc-30), 50 mg/kg cocaine (Coc-50), EMCV+Coc-10, EMCV+Coc-30, EMCV+Coc-50. After inoculation with EMCV, the mice were treated daily with either cocaine or saline for 90 days. Mice were euthanized at different days after EMCV inoculation. Mortality was recorded and myocarditis severity was evaluated. The mortality of the myocarditis mice treated with cocaine increased significantly, from 22% (EMCV) to 25.7% (Coc-10+EMCV), 41.4% (Coc-30+EMCV), and 51.4% (Coc-50+EMCV) (P < 0.05), respectively. The incidence and severity of inflammatory cell infiltration and myocardial lesions was higher in infected mice exposed to cocaine. Cocaine administered only before infection did not exacerbate myocarditis. Norepinephrine (NE) assay showed that cocaine exposure significantly increased myocardial NE concentration but this increase was partially inhibited in infected animals. Adrenalectomy abolished the effect of cocaine on mortality. Furthermore, propranolol, a beta-blocker, significantly decreased the enhancing effects of cocaine on myocarditis mice. In conclusion, cocaine increases the severity and mortality of viral myocarditis in mice. Increased catecholamines may be a major factor responsible for this effect.  相似文献   

19.
Bloodstream forms of Trypanosoma brucei brucei were grown over baby hamster kidney cells in minimum essential medium with various concentrations of metronidazole (Flagyl) and chloroquine. Both drugs inhibited the multiplication of the parasite in vitro. The least effective concentrations for metronidazole and chloroquine were 0.003 mg/ml and 0.0024 mg/ml, respectively. Groups of 12-day-old female CDI mice were treated with 1 of the 2 drugs at 24, 48, and 72 hr after T. brucei infection. The drugs administered stat or daily reduced the number of parasites in the mice but did not effect a cure; they prolonged the survival period of the animals. However, metronidazole (0.1 mg/kg body weight) and chloroquine (0.08 mg/kg body weight) combined and given daily for 4 consecutive days cleared the infection. No trypanosomes were detected in the blood of these mice 3 mo after treatment. The dosages for both the in vitro (metronidazole 0.003 mg/ml; chloroquine 0.0024 mg/ml) and in vivo (metronidazole 0.1 mg/kg body weight; chloroquine 0.08 mg/kg body weight) were well below those prescribed for humans.  相似文献   

20.
We examined the effect of Japanese green tea extract (JGTE) on enterohemorrhagic Escherichia coli (EHEC) O157:H7 infection in a gnotobiotic mouse model. Gnotobiotic mice inoculated with an EHEC strain developed neurologic and systemic symptoms, usually culminating in death. In contrast, none of mice receiving dietary JGTE showed clinical signs or death. This report describes the effect of JGTE, which includes the inhibition of bacterial growth in vivo. The Shiga-like toxin (SLT) level in the feces of the JGTE diet group was significantly lower than that of the control group.  相似文献   

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