PHARMACOLOGICAL AND MECHANISTIC STUDIES OF UREQUINONA, A MOLECULE FROM ROOTS OF PENTALINON ANDRIEUXII MUELL-ARG THAT HEALS MURINE LEISHMANIA MEXICANA INFECTION.

In this work we tested both the in vitro and in vivo anti-Leishmania mexicana activity of a molecule we originally identified in the root of Pentalinon andrieuxii Muell-Arg, a plant that is widely used in Mayan traditional medicine. The chemical name of this molecule is 24-methylcholesta-4-24(28)-dien-3-one, but for simplicity's sake, we assigned the short and trivial name of urequinona that will be used throughout this work. It induces necrosis and apoptosis of promastigotes cultured in vitro and extensive ultrastructural damage of amastigotes. It also induces production of Interleukin (IL)-2 and interferon (IFN)-γ by splenic cells from infected and urequinona treated mice stimulated in vitro with parasite antigen (Ag) but inhibits the production of IL-6 and IL-12p70 by bone-marrow-derived macrophages (BMM) infected in vitro and then treated with urequinona. It also induces activation of transcription factors such as NFkB and AP-1 (NFkB/AP-1) in RAW reporter cells. We also developed a novel pharmaceutical preparation of urequinona encapsulated in hydroxyethyl cellulose for dermal application that significantly reduced (P < 0.05) experimentally induced ear lesions of C57BL/6 mice. We conclude the preparation containing this molecule is a good candidate for a novel anti-leishmanial drug's preparation.

Decanethiol functionalized silver nanoparticles are new powerful leishmanicidals in vitro.

We evaluated, for the first time, the leishmanicidal potential of decanethiol functionalized silver nanoparticles (AgNps-SCH) on promastigotes and amastigotes of different strains and species of Leishmania: L. mexicana and L. major isolated from different patients suffering from localized cutaneous leishmaniasis (CL) and L. mexicana isolated from a patient suffering from diffuse cutaneous leishmaniasis (DCL). We recorded the kinetics of promastigote growth by daily parasite counting for 5 days, promastigote mobility, parasite reproduction by CFSE staining's protocol and promastigote killing using the propidium iodide assay. We also recorded IC50's of promastigotes and amastigotes, therapeutic index, and cytotoxicity by co-culturing macrophages with AgNps-SCH or sodium stibogluconate (Sb) used as reference drug. We used Sb as a reference drug since it is used as the first line treatment for all different types of leishmaniasis. At concentrations 10,000 times lower than those used with Sb, AgNps-SCH had a remarkable leishmanicidal effect in all tested strains of parasites and there was no toxicity to J774A.1 macrophages since > 85% were viable at the concentrations used. Therapeutic index was about 20,000 fold greater than the corresponding one for Sb treated cells. AgNps-SCH inhibited > 80% promastigote proliferation in all tested parasites. These results demonstrate there is a high leishmanicidal potential of AgNps-SCH at concentrations of 0.04 µM. Although more studies are needed, including in vivo testing of AgNps-SCH against different types of leishmaniasis, they can be considered a potential new treatment alternative.

17Beta-estradiol increases Leishmania mexicana killing in macrophages from DBA/2 mice by enhancing production of nitric oxide but not pro-inflammatory cytokines.

We have previously shown that female DBA/2 mice are significantly more resistant to Leishmania mexicana compared with males. Here, we have analyzed the effect of 17beta-estradiol (E(2)) on function and cytokine production in male and female DBA/2 macrophages in vitro. We show that E(2) increases NO production and parasite killing in L. mexicana-infected male and female DBA/2 macrophages without increasing production of pro-inflammatory cytokines. These data indicate that E(2) may enhance leishmanicidal activity in macrophages by directly regulating production of NO.

Serotypes of Vibrio cholerae non-O1 isolated from water supplies for human consumption in Campeche, México and their antibiotic susceptibility pattern.

The presence of Vibrio cholerae non-O1 in water supplies for human consumption in the city of Campeche and rural locality of Bécal was investigated. V. cholerae non-O1 was detected in 5.9% of the samples obtained in deep pools of Campeche. Studies conducted in Bécal and neighbourhood of Morelos in Campeche indicated that collected samples harbored V. cholerae non-O1 in 31.5% and 8.7% respectively. There was a particular pattern of distribution of V. cholerae non-O1 serotypes among different studied regions. Accordingly, V. cholerae non-O1 serotype O14 predominated in the deep pools of Campeche and together with V. cholerae non-O1, O155 were preferentially founds in samples taken from intradomiciliary faucets in the neighbourhood of Morelos. Samples from Bécal predominantly presented the serotype O112. 60% and 53.8% of all studied strains of V. cholerae non-O1 proved to be resistant to ampicillin and carbenicillin. 3.1%, 7.7% and 6.2% presented resistant to doxycycline, trimethoprim-sulfamethoxazole and erythromycin respectively. The study showed the necessity of performing a strong epidemiologic surveillance for emergence and distribution of V. cholerae non-O1.

[Sanitary quality of water for human consumption a in rural community of Mexico]. / Calidad sanitaria del agua para consumo humano en una comunidad rural de México.

The purpose of this study was to evaluate the quality of water for human consumption in Bécal, rural community of México. The presence of total and fecal coliforms, as well as aerobic plate counts in differents places of the water distribution network, in intradomiciliary deep pools and rainwater cistern system were investigated. Results from this set of experiments suggest the existance of local social and environmental factors that open the way for water contamination with organic material in the water sources studied. We demonstrated the necessity of performing a careful sanitary control and proper handling of water for human consumption through programs of systematic surveillance of the water supplies in order to provide good quality water to the population of this rural community. Additionally, it is necessary to perform educational programs about procedures for preservation of hygiene with special reference to prevention of gastrointestinal diseases.

Vaccination of C57BL/6 mice against cutaneous leishmaniosis. Kinetics of antibody synthesis and induction of cellular responses.

In this report, the effectiveness of vaccination of C57BL/6 mice and its association to long term production of IgG anti-Leishmania, delayed type hypersensitivity response (DTH) and the enlargement of the spleen associated to hyperplasia or parasite visceralization were studied. Mice were vaccinated with Leishmania-membrane antigens incorporated into liposomes, and two weeks later, animals received a homologous challenge with living amastigotes. Antibody levels were weekly recorded during 18 weeks after immunization. It was concluded that this vaccine induces disease-resistance in C57BL/6 mice and this effect correlates with the production of IgG anti-Leishmania, but not with the induction of a DTH or lymphoid hyperplasia.

CD4+, CD8+ and CD4- CD8- T cell-subsets can confer protection against Leishmania m. mexicana infection

We studied the role of CD4+, CD8+, CD4- CD8- T cells and IgG anti-Leishmania after infection or vaccination in the CBA/ca mouse. Mice were either infected with L. m. mexicana promastigotes or vaccinated with parasite-membrane antigens incorporated into liposomes. Successfully vaccinated mice were used as cell-donors in adoptive transfer experiments. Naive, syngeneic recipients received highly-enriched CD4+, CD8+ or CD4- CD8- T cells from those two set of donors and challenged with live parasites. Our results showed that, both CD4+ and CD8+ T cells from infected or vaccinated donors conferred significant disease-resistance to naive recipients. In addition, adoptive transfer of CD4- CD8- T cells from vaccinated donors significantly delayed lesion growth in recipient mice. We concluded that vaccination of CBA mice correlates with the induction of protective CD4+, CD8+ and CD4- CD8- T cells and the synthesis of IgG anti-Leishmania.

CD4+, CD8+ and CD4- CD8- T cell-subsets can confer protection against Leishmania m. mexicana infection.

We studied the role of CD4+, CD8+, CD4- CD8- T cells and IgG anti-Leishmania after infection or vaccination in the CBA/ca mouse. Mice were either infected with L. m. mexicana promastigotes or vaccinated with parasite-membrane antigens incorporated into liposomes. Successfully vaccinated mice were used as cell-donors in adoptive transfer experiments. Naive, syngeneic recipients received highly-enriched CD4+, CD8+ or CD4- CD8- T cells from those two set of donors and challenged with live parasites. Our results showed that, both CD4+ and CD8+ T cells from infected or vaccinated donors conferred significant disease-resistance to naive recipients. In addition, adoptive transfer of CD4- CD8- T cells from vaccinated donors significantly delayed lesion growth in recipient mice. We concluded that vaccination of CBA mice correlates with the induction of protective CD4+, CD8+ and CD4- CD8- T cells and the synthesis of IgG anti-Leishmania.

[Sanitary quality of water supply for human consumption in Campeche]. / Calidad sanitaria de los suministros de agua para consumo humano en Campeche.

This paper presents data of a study undertaken to know the sanitary features of water supply (deep pools) for human consumption in the city of Campeche, Mexico. Levels of intestinal bacteria (total and fecal coliforms) were monitored, as well as heterotrophic plate counts and the surroundings of each deep pool were inspected. Each water supply was monitored three times from January to July, 1993 and presented unacceptable levels of heterotrophic plate counts and coliforms which is a strong evidence of fecal contamination of animal or human origin. These findings are a clear indication of unacceptable contamination of water supply for human consumption which requires an improvement and systematic inspection in order to provide good quality water to the population of Campeche.