Persistent damage to Enterocytozoon bieneusi, with persistent symptomatic relief, after combined furazolidone and albendazole in AIDS patients.
AIM: To investigate morphological changes in Enterocytozoon bieneusi and the duration of symptomatic relief after combination treatment with furazolidone and albendazole in AIDS patients. METHODS: Four severely immunocompromised AIDS patients with symptomatic E bieneusi infection of the gut received an 18 day course of combined furazolidone and albendazole (500 + 800 mg daily). All patients were monitored for parasite shedding in stool by light microscopy at the end of treatment and monthly during follow up. At the end of treatment, duodenal biopsy specimens obtained from three patients were studied by transmission electron microscopy by two pathologists blind to the patients' treatment or clinical outcome. Duodenal biopsy specimens obtained from one of the patients two months after completion of treatment were also studied electronmicroscopically. RESULTS: All patients had long lasting symptomatic relief, with a major decrease--or transient absence--of spore shedding in stools from completion of treatment. After treatment, changes in faecal spores were persistently found by light microscopy in all cases, and there was evidence of both a substantial decrease in the parasite load and ultrastructural damage in the parasite in all biopsy specimens. The treatment was well tolerated, and no patient had clinical or parasitological relapse during follow up (up to 15 months). CONCLUSIONS: The long lasting symptomatic relief observed in all four treated patients correlated with the persistent decrease in parasite load both in tissue and in stool, and with the morphological changes observed in the life cycle of the protozoan. These data suggest that combined treatment with furazolidone and albendazole is active against E bieneusi and may result in lasting remission even in severely immunocompromised patients. (+info)
U.S. Food and Drug Administration approval of AmBisome (liposomal amphotericin B) for treatment of visceral leishmaniasis.
In August 1997, AmBisome (liposomal amphotericin B, Nexstar, San Dimas, CA) was the first drug approved for the treatment of visceral leishmaniasis by the U.S. Food and Drug Administration. The growing recognition of emerging and reemerging infections warrants that safe and effective agents to treat such infections be readily available in the United States. The following discussion of the data submitted in support of the New Drug Application for AmBisome for the treatment of visceral leishmaniasis shows the breadth of data from clinical trials that can be appropriate to support approval for drugs to treat tropical diseases. (+info)
Activity of disulfiram (bis(diethylthiocarbamoyl)disulphide) and ditiocarb (diethyldithiocarbamate) against metronidazole-sensitive and -resistant Trichomonas vaginalis and Tritrichomonas foetus.
Clinical resistance of Trichomonas vaginalis to metronidazole is best correlated with MIC values measured under aerobic conditions. Under these conditions both disulfiram (bis(diethylthiocarbamoyl)disulphide), and its first mammalian metabolite, ditiocarb (diethyldithiocarbamate), showed high levels of activity against metronidazole-sensitive (disulfiram MIC, 0.1-0.7 microM; ditiocarb MIC, 0.3-9 microM) and -resistant (MICs 0.2-1.3 microM and 1.2-9 microM respectively) isolates. Tritrichomonas foetus was also sensitive-the MICs for seven metronidazole-sensitive isolates were 0.1-1.0 microM for disulfiram and 1.0-6.9 microM for ditiocarb; those for two highly metronidazole-resistant strains were 0.3-1.3 microM and 0.6-6 microM respectively. Under anerobic conditions most strains became highly resistant to both compounds. Surprisingly, disulfiram was consistently more active than ditiocarb. (+info)
Value of Western blotting in the clinical follow-up of canine leishmaniasis.
Specific serum antibody levels in Leishmania infantum-infected dogs treated with a combination of glucantime and allopurinol were estimated by indirect immunofluorescence and Western blotting. The sensitivity of Western blot was greater than that obtained with immunofluorescence titration. In general, both diagnostic methods concurred with the post-treatment clinical status of the animals. Clinical improvement of successfully treated dogs was related to lower immunofluorescence titers and simpler and/or less reactive immunodetection patterns in Western blotting. The recognition, by infected dogs, of certain low molecular weight antigens, particularly one of approximately 26 kDa, was restricted to pretreatment samples and a single animal in relapse thus apparently constituting an active infection marker. (+info)
Recombinant bactericidal/permeability-increasing protein (rBPI21) in combination with sulfadiazine is active against Toxoplasma gondii.
The activity of recombinant bactericidal/permeability-increasing protein (rBPI21), alone or in combination with sulfadiazine, on the intracellular replication of Toxoplasma gondii was assessed in vitro and in mice with acute toxoplasmosis. rBPI21 markedly inhibited the intracellular growth of T. gondii in human foreskin fibroblasts (HFFs). Following 72 h of exposure, the 50% inhibitory concentration of rBPI21 for T. gondii was 2.6 micrograms/ml, whereas only slight cytotoxicity for HFF cells was observed at the concentrations tested. Subsequent mathematical analyses revealed that the combination of rBPI21 with sulfadiazine yielded slight to moderate synergistic effects against T. gondii in vitro. Infection of mice orally with C56 cysts or intraperitoneally (i.p.) with RH tachyzoites resulted in 100% mortality, whereas prolongation of the time to death or significant survival (P = 0.002) was noted for those animals treated with 5 to 20 mg of rBPI21 per kg of body weight per day. Treatment with rBPI21 in combination with sulfadiazine resulted in significant (P = 0.0001) survival of mice infected i.p. with tachyzoites but not of mice infected orally with T. gondii cysts. These results indicate that rBPI21 is active in vitro and in vivo against T. gondii and that its activity is significantly enhanced when it is used in combination with sulfadiazine. To our knowledge, this is the first report of the activity of rBPI21 against a protozoan parasite. (+info)
Indolylquinoline derivatives are cytotoxic to Leishmania donovani promastigotes and amastigotes in vitro and are effective in treating murine visceral leishmaniasis.
A wide variety of biologically active compounds contain indole and quinoline nuclei. Some novel indolylquinoline derivatives were synthesized from indole by Friedel-Crafts acylation reaction. Out of the four derivatives tested, 2-(2''-acetamidobenzyl)-3-(3'-indolylquinoline) (C) had no effect on the promastigotes or amastigotes of Leishmania donovani in vitro. The remaining three analogues, 2-(2''-dichloroacetamidobenzyl)-3-(3'-indolylquinoline) (A), 2-(2''-chloroacetamidobenzyl)-3-(3'-indolylquinoline) (B), and 2-(2''-aminobenzyl)-3-(3'-indolylquinoline) (D), inhibited the growth of L. donovani promastigotes in vitro and were cytotoxic to both the promastigote and amastigote forms of the parasite. These three derivatives were also effective in eliminating L. donovani amastigotes from BALB/c mouse peritoneal macrophages in vitro. One indolylquinoline derivative [A] was used to treat established visceral leishmaniasis in BALB/c mice. This compound was significantly more effective than sodium antimony gluconate (SAG) in reducing the splenic parasite load at a much lower concentration (5% of SAG). Our results suggest that indolylquinoline derivatives may be exploited as antileishmanial agents. (+info)
What controls glycolysis in bloodstream form Trypanosoma brucei?
On the basis of the experimentally determined kinetic properties of the trypanosomal enzymes, the question is addressed of which step limits the glycolytic flux in bloodstream form Trypanosoma brucei. There appeared to be no single answer; in the physiological range, control shifted between the glucose transporter on the one hand and aldolase (ALD), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), phosphoglycerate kinase (PGK), and glycerol-3-phosphate dehydrogenase (GDH) on the other hand. The other kinases, which are often thought to control glycolysis, exerted little control; so did the utilization of ATP. We identified potential targets for anti-trypanosomal drugs by calculating which steps need the least inhibition to achieve a certain inhibition of the glycolytic flux in these parasites. The glucose transporter appeared to be the most promising target, followed by ALD, GDH, GAPDH, and PGK. By contrast, in erythrocytes more than 95% deficiencies of PGK, GAPDH, or ALD did not cause any clinical symptoms (Schuster, R. and Holzhutter, H.-G. (1995) Eur. J. Biochem. 229, 403-418). Therefore, the selectivity of drugs inhibiting these enzymes may be much higher than expected from their molecular effects alone. Quite unexpectedly, trypanosomes seem to possess a substantial overcapacity of hexokinase, phosphofructokinase, and pyruvate kinase, making these "irreversible" enzymes mediocre drug targets. (+info)
Cost-effectiveness analysis of humanitarian relief interventions: visceral leishmaniasis treatment in the Sudan.
Spending by aid agencies on emergencies has quadrupled over the last decade, to over US$6 billion. To date, cost-effectiveness has seldom been considered in the prioritization and evaluation of emergency interventions. The sheer volume of resources spent on humanitarian aid and the chronicity of many humanitarian interventions call for more attention to be paid to the issue of 'value for money'. In this paper we present data from a major humanitarian crisis, an epidemic of visceral leishmaniasis (VL) in war-torn Sudan. The special circumstances provided us, in retrospect, with unusually accurate data on excess mortality, costs of the intervention and its effects, thus allowing us to express cost-effectiveness as the cost per Disability Adjusted Life Year (DALY) averted. The cost-effectiveness ratio, of US$18.40 per DALY (uncertainty range between US$13.53 and US$27.63), places the treatment of VL in Sudan among health interventions considered 'very good value for money' (interventions of less than US$25 per DALY). We discuss the usefulness of this analysis to the internal management of the VL programme, the procurement of funds for the programme, and more generally, to priority setting in humanitarian relief interventions. We feel that in evaluations of emergency interventions attempts could be made more often to perform cost-effectiveness analyses, including the use of DALYs, provided that the outcomes of these analyses are seen in the broad context of the emergency situation and its consequences on the affected population. This paper provides a first contribution to what is hoped to become an international database of cost-effectiveness studies of health interventions during relief operations, which use a comparable measure of health outcome such as the DALY. (+info)