Detergent-resistance percentage (conversion rate) of <i>E. histolytica</i> trophozoites treated with treatment solution at different times.

a<p>Treatment solution (Merck): Hydrogen peroxide 30%, cadmium 0.02 ppm, cobalt 0.02 ppm, copper 0.02 ppm, iron 0.1 ppm, nickel 0.02 ppm, lead 0.02 ppm, zinc 0.02 ppm, free Sulfuric acid 40 ppm, chlorine 0.5 ppm, phosphate 5 ppm, sulfate 2 ppm.</p>b<p>Three independent experiments were done in triplicates.</p><p>Conversion rate: percent of cells that were resistant to 0.5% SDS.</p><p>FDA: fluorescein diacetate.</p><p>S.D.: Standard deviation.</p

Ultrastructural analysis of <i>E. histolytica</i> CLS resistant to detergents.

<p>(A) Light microscopy of a CLS stained with Lugol's Iodine showing its spherical shape, multi-nucleation and partial refringence; (B, C and D) Transmission electron microscopy of CLS showing two, three and four nuclei, respectively (arrow heads). High number of cytoplasmic vacuoles are also observed; (E) and (F) Scanning electron microscopy showing the smooth surface, spherical shape and small size of the CLS. Inbox in F shows a magnification of a hole in the surface of a CLS, where overlapping fibers that resembles chitin-fibers in other organisms are observed <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0000607#pntd.0000607-Gorb1" target="_blank">[6]</a>,<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0000607#pntd.0000607-Park1" target="_blank">[7]</a>.</p

RT-PCR primers used in this work.

<p>RT-PCR primers used in this work.</p

Detection of chitin in <i>E. histolytica</i> CLS resistant to detergents by calcofluor white staining (upper panel) and a WGA-binding assay (bottom graphic).

<p>(A and B) Light and UV microscopy, respectively, of a mix culture of untreated trophozoites and CLS stained with calcofluor white. CLS is clearly differentiated from trophozoites by the spherical shape and small size. In B, blue fluorescence of CLS under UV contrasts with the absence of fluorescence in the trophozoites 20X; (C and D) Comparison of calcofluor staining of CLS (C) against an <i>E. histolytica</i> cyst isolated from human feces (D). In spite of both showing a similar blue-whitish fluorescence, staining of the surface is clearer in the cyst from human feces, whereas staining of some apparently internal structures (arrowheads), probably transporting vacuoles, is evident in the CLS (40X). In the bottom graphic, bars represent the standard deviations.</p

Gln6Pi enzyme mRNA expression levels assessed by RT-PCR in <i>E. histolytica</i> CLS resistant to detergents.

<p>Total RNA was purified from untreated trophozoites (lane a), cysts isolated from human feces (lane b) and the CLS (lane c) and RT-PCR amplified by using specific oligonucleotides for <i>E. histolytica</i> Gln6Pi gene. Clear over-expression of Gln6Pi is observed in CLS (25 folds) respect to the basal expression in untreated trophozoites. Parallel RT-PCR amplification of the ADP-ribosylating factor (ARF) for each sample was used as internal loading control.</p

Allocation of CONACYT¹ (FOMIX², FOSISS³, and FOSIB⁴) funds, by research methodology and objective (2003–2010)^*.

*<p>Amounts in millions of US dollars adjusted for purchasing power parity.</p>1<p>CONACYT: National Council on Science and Technology.</p>2<p>FOMIX: Mixed Funds.</p>3<p>FOSISS: Sectoral Fund for Research in Health and Social Security.</p>4<p>FOSIB: Sectoral Fund for Basic Research.</p

Federal Government budget for Health, R&D, and Health R&D^*.

*<p>Amounts in millions of US dollars adjusted for purchasing power parity (US$ PPP).</p>1<p>Refers to total net expenditure projected in the Expenditure Budget of the Federation for the corresponding fiscal year, Ministry of Finance (SHCP).</p>2<p>Includes the budget of Branch 12 Health, Mexican Institute of Social Security (IMSS) and Institute of Social Security for State Workers (ISSSTE) excluding the pension and retirement contributions. For 2009 and 2010 correspond to the Retirement and Pensions allocation of the branches GYN and GYR. From 2002 to 2008 corresponds to the item “old age” in the branches GYN and GYR. Data for 2000 and 2001 were taken from the Branch 19 “Contributions to Social Security” specified for each entity.</p>3<p>Includes the resources for science and technology allocated to National Council on Science and Technology (CONACYT), Ministry of Education (SEP), Ministry of Energy (SENER), Ministry of Health (including IMSS and ISSSTE), Ministry of Agriculture, Livestock, Rural Development, Fisheries and Food (SAGARPA), Ministry of Economy (SE), Ministry of Environment and Natural Resources (SEMARNAT), Office of the Mexican Attorney-General (PGR), Ministry of Communications and Transport (SCT), Ministry of National Defense (SEDENA), Secretary of Navy (SEMAR) and Ministry of Tourism (SECTUR), including own resources.</p>4<p>Refers to the resources allocated to science and technology in the Branch 12 Health, IMSS and ISSSTE, including own resources.</p><p>Sources: Based on information of CONACYT, SHCP, Central Bank of Mexico (BANXICO), and World Bank.</p

Evolution of the health research funding by research methodology.

<p>For each Sectoral Fund, the health-related projects were classified according to the methodology employed in biomedical research, clinical research, or public health research. The total amount awarded per methodology from 2003 to 2010 was estimated (A). Note that resources of Sectoral Fund for Basic Research (FOSIB) were mainly allocated to biomedical projects, whereas resources of Sectoral Fund for Research on Health and Social Security (FOSISS) were mostly directed to clinical projects. FOMIX: Mixed Funds.</p

National Council on Science and Technology (CONACYT) investment on health research.

<p>The annual evolution of resources assigned to the Mixed Funds (FOMIX), Sectoral Fund for Research on Health and Social Security (FOSISS), and Sectoral Fund for Basic Research (FOSIB) is presented. The cash amounts are in US dollars adjusted for purchasing power parity (US$ PPP).</p

Project distribution by research objectives and annual amounts funded.

<p>A: The share for each research objective (in percent) within National Council on Science and Technology (CONACYT) funds. B: Budget fluctuations for each thematic objective over the period. Research projects were classified by thematic objective considering nine categories: health determinants (1.social, economic and cultural), health conditions (2. noncommunicable diseases; 3. communicable diseases; 4. nutrition and environment; 5. violence and accidents), and actions or interventions (6. research on health policy, systems and services; 7. technological R&D; 8. basic science; and 9. traditional medicine). FOSIB: Sectoral Fund for Basic Research; FOMIX: Mixed Funds; FOSISS: Sectoral Fund for Research in Health and Social Security.</p