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Nigenda G, Orozco E, Guzmán M, Mora G, Lockett L, Pacheco C. The role of priority programmes in the provision of health services in the state of Oaxaca, Mexico. Health Policy 1998; 43:125-39. [PMID: 10177614 DOI: 10.1016/s0168-8510(97)00092-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
An assessment of the performance of five priority health programmes (basic sanitation, tuberculosis, vaccination, acute respiratory infections and acute diarrheal diseases) was carried out using ethnographic techniques in the region of La Cañada in the state of Oaxaca, Mexico. The region presents a large percentage of Indian and peasant population living in extreme poverty and health care is mainly provided by the Ministry of Health. Both characteristics of the population and the health services are used to analyze the performance of the programmes. With access to abundant resources, vaccination and diarrheal disease programmes have been highly successful in involving the population and achieving their operative targets. Consequently this capacity to concentrate resources results in a lack of resources for other programmes. Despite partial successes, all programmes face serious operational difficulties demonstrating, in turn, the lack of capacity of health services to respond to the specific demands of local populations. The information presented is relevant for the discussion of selective versus comprehensive PHC.
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Báez-Camargo M, Gharaibeh R, Riverón AM, de la Cruz Hernández F, Luna JP, Gariglio P, Chávez P, Orozco E. Gene amplification in Entamoeba histolytica. INVASION & METASTASIS 1997; 16:269-79. [PMID: 9371226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We show here data suggesting that Entamoeba histolytica, the protozoan responsible for human amebiasis, presents DNA amplification in a fashion similar to that described for transformed mammalian cells. By transmission electron microscopy (TEM), we found linear, circular and concentric circular DNA molecules exhibiting the main events of the unscheduled DNA amplification process. Loops were formed after the recombination of two nonadjacent DNA regions, and bubbles appeared from the recombinant strands without involving the looped-out sequences. Bubbles grew up and underwent further replication rounds to produce a nested set of partially replicated circles. Multicircle complexes were also formed from putative replication origin without recombination of distant DNA regions. Clones derived from the strain HM1:IMSS exhibited different DNA contents, suggesting DNA amplification. The parental clone A and its daughter clone C2 differed in rDNA gene copy numbers, but this was observed only when total DNA was separated by pulse field gel electrophoresis, and no significant differences were detected in nuclear DNA. The dissection of the events observed by TEM led us to propose an onion skin model for gene amplification in E. histolytica.
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Nigenda-López G, Orozco E, Leyva R. [Motives for non-vaccination: critical review of the international literature, 1950-1990]. Rev Saude Publica 1997; 31:313-20. [PMID: 9515270 DOI: 10.1590/s0034-89101997000300015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Many countries have acknowledged that vaccination programs call for a mastery of technical and organizational elements if they are to become accessible to the population. One of these elements has been greatly underestimated: the participation of populations and their motivations. Experiences in several countries are here analysed, on the basis of a bibliographic revision of the period 1950-1990. Results show that existing studies vary in their conceptual and methodological focuses, according to the region in which research was carried out and to the kind of researcher involved. This fact is to be explained by the posture, common among researchers, of believing that they know in depth the subjective determinants of the behavior of the societies to which they belong. Based on this, they only use methodologies that allow them to arrive at a superficial understanding regarding the response of populations to the offer of vaccines.
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Orozco E, Gharaibeh R, Riverón AM, Delgadillo DM, Mercado M, Sánchez T, Gómez Conde E, Vargas MA, López-Revilla R. A novel cytoplasmic structure containing DNA networks in Entamoeba histolytica trophozoites. MOLECULAR & GENERAL GENETICS : MGG 1997; 254:250-7. [PMID: 9150258 DOI: 10.1007/s004380050413] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We report here the presence of cytoplasmic DNA arranged in networks in the trophozoites of the human parasite Entamoeba histolytica. Cytoplasmic DNA was detected in live trophozoites in a structure that we called EhkO, using the fluorescent dye acridine orange, and by in situ hybridization to trophozoites with a rDNA probe. The EhkO was found in the axenically grown clones A, L6 (strain HMI:IMSS) and MAVax (strain MAV) and in the polyxenically grown clone MAVpx (strain MAV). Bacteria present in MAVpx did not cross hybridize with the DNA probe neither in in situ hybridization or in Southern blot experiments. Autoradiography of metabolically [3H]thymidine-labeled trophozoites showed the presence of EhkO, and an EhkO-enriched fraction, purified from a nuclei-free extract and examined by light microscopy, exhibited [3H]thymidine incorporation into this structure. DNA was purified from the EhkO and enriched nuclear fractions and analyzed by transmission electron microscopy. The EhkO fraction contained DNA networks resembling those of trypanosome kDNA, whereas nuclear DNA was present mainly as linear molecules and some circles. Our findings imply that E. histolytica may be taxonomically more closely related to the Trypanosomatidae than previously suspected.
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Báez-Camargo M, Sánchez T, Solis F, Rodríguez MA, Contreras G, Chávez P, Riverón AM, Orozco E. Cytoplasmic DNA in Entamoeba histolytica: its biological significance. Arch Med Res 1997; 28:5-9. [PMID: 9078580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We report a study on the DNA organization in Entamoeba histolytica using a ribosomal DNA probe. The rDNA genes were found forming mers which were separated in a typical ladder pattern by pulse field electrophoresis. DNA rosette structures were visualized through electron microscopy in DNA eluted from bands recognized by the ribosomal probe. The in situ hybridization experiments using a DNA probe suggested that the rDNA genes are portioned between the nucleus and a cytoplasmic structure. These findings provide new data on DNA organization in E. histolytica and open the question concerning the presence of a novel organelle in this eukaryotic parasite.
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Hidalgo ME, Sánchez R, Pérez DG, Rodríguez MA, García J, Orozco E. Molecular characterization of the Entamoeba histolytica enolase gene and modelling of the predicted protein. FEMS Microbiol Lett 1997; 148:123-9. [PMID: 9084139 DOI: 10.1111/j.1574-6968.1997.tb10277.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Entamoeba histolytica obtains its energy mainly from glucose fermentation. Enzymes involved in this pathway could be potential targets for antiparasite drugs. Here we report the molecular characterization of the E. histolytica enolase gene (Ehenl-I), which in a single copy is located on the 1.6 Mb chromosome. It is transcribed into a 1.4 kb mRNA which starts 13 nucleotides upstream of the ATG start codon. The sequence TATAAG, at -31, interacted with nuclear proteins suggesting that it has a TATA box function. Protein modelling allowed us to identify a putative specific region that differs from human enolase and could be a good target for the design of novel drugs against E. histolytica.
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De Menezes Feitosa L, Salgado LM, Rodríguez MA, Vargas MA, Orozco E. Phenotype variability and genetic polymorphism in Entamoeba histolytica clonal populations. Arch Med Res 1997; 28 Spec No:27-9. [PMID: 9033000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Hernández R, Luna-Arias JP, Orozco E. Comparison of the Entamoeba histolytica TATA-binding protein (TBP) structure with other TBP. Arch Med Res 1997; 28 Spec No:43-5. [PMID: 9033007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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59
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De Menezes LF, Rodríguez MA, Vargas MA, Salgado LM, Orozco E. Effect of bacterial association on the phenotype and genotype of an Entamoeba histolytica clonal population. INVASION & METASTASIS 1997; 17:176-88. [PMID: 9778590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
Abstract
A several-times-cloned population of Entamoeba histolytica trophozoites (clone MAVIII) was cultured under axenic (MAVIIIax), monoxenic (MAVIIImx) and polyxenic (MAVIIIpx) conditions. Clones MAVIIIax and MAVIIImx presented similar virulence in vitro, but differed in their virulence in vivo, whereas MAVIIIpx trophozoites were neither virulent in vitro or in vivo. The MAVIII clones maintained their zymodeme and exhibited three unusual glucose phosphate isomerase bands, absent in other E. histolytica strains studied. Similar patterns were shown by the three MAVIII clones in the signature of a 482-bp DNA fragment from the M17 gene (which encodes for a variable immunodominant antigen), obtained by low stringency single specific primer PCR technique. However, MAVIII clones displayed genotypic variability in the patterns obtained by the random amplified polymorphic DNA technique using total DNA as template. Results suggest that monomorphism is kept in certain regions of the genome, mainly in those carrying protein encoding genes, but a high polymorphism is present in total DNA of cloned trophozoites cultured under different conditions, confirming the plasticity of the E. histolytica genome.
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Rodríguez MA, García-Pérez RM, Orozco E. Subcellular location of the pyruvate: ferredoxin oxidoreductase from Entamoeba histolytica. Arch Med Res 1997; 28 Spec No:89-90. [PMID: 9033024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Castro R, Eroza E, Orozco E, Manca MC, Hernández JJ. [Management strategies in HIV/AIDS at the family level]. SALUD PUBLICA DE MEXICO 1997; 39:32-43. [PMID: 9092096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
OBJECTIVE To identify the critical points of the trajectories of the families of persons with AIDS which may serve as a basis to develop educational and support programs. THEORY AND METHODS A qualitative investigation was conducted in 1995 in Ciudad Netzahualcóyotl, State of Mexico, Mexico. Rapid Assessment Procedures (RAP) were applied to determine the social, economic, demographic and cultural context of persons with HIV/AIDS in the community. Forty-six in-depth interviews were applied to persons with AIDS, their families and people from their social networks. RESULTS The main aspects of the family response to the HIV/ AIDS are characterized, and it is demonstrated that it is possible to identify critical points in such a response which can be targeted through specific interventions. In Ciudad Netzahualcóyotl, a context of poverty, a migrating tradition, and gender social relations are the basis of the acceptance or rejection of persons with AIDS. The main finding refers to the ambiguos attitude, ranging from rejection to support, displayed by family members of persons with AIDS. This pattern varies according to the history and specific conditions of each family. CONCLUSIONS Specific health interventions are proposed to support families with one or more persons with AIDS.
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Flores E, Riveron AM, Báez-Camargo M, Orozco E. Identification of putative linear and circular DNA molecules in the Entamoeba histolytica molecular karyotype. Arch Med Res 1997; 28 Spec No:5-7. [PMID: 9032992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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63
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Orozco E, Báez-Camargo M, Riveron AM, Gharibeh R, Gariglio P, de la Cruz Hernández F, Chávez P. A model for unscheduled DNA replication in Entamoeba histolytica trophozoites. Arch Med Res 1997; 28 Spec No:24-6. [PMID: 9032999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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64
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García-Rivera G, Avila A, Ayala P, Arroyo R, Rigothier MC, Orozco E. Identification and location of the cell-binding domain in the 112 kDa adhesin gene of Entamoeba histolytica. Arch Med Res 1997; 28 Spec No:164-5. [PMID: 9033055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Báez-Camargo M, Riveron AM, Flores E, Orozco E. Organization of Entamoeba histolytica ribosomal and structural genes in PFGE. Arch Med Res 1997; 28 Spec No:8-10. [PMID: 9032993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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66
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Delgadillo DM, Rodriguez M, Sanchez T, Orozco E. In situ location of the Ehredox and 16S rDNA genes in Entamoeba histolytica trophozoites. Arch Med Res 1997; 28 Spec No:11-3. [PMID: 9032994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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67
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Hidalgo ME, Orozco E. Structural characterization of the Entamoeba histolytica enolase gene promoter. Arch Med Res 1997; 28 Spec No:46-8. [PMID: 9033008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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68
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De Dios Bravo G, Luna-Arias JP, Gariglio P, Chávez P, Orozco E. Localization of a retinoblastoma-like protein in Entamoeba histolytica. Arch Med Res 1997; 28 Spec No:21-3. [PMID: 9032998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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69
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Gharaibeh R, Chávez P, Orozco E. A comparison in the ultrastructure of nuclear and extra-nuclear DNA of Entamoeba histolytica. Arch Med Res 1997; 28 Spec No:119-21. [PMID: 9033036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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70
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Gómez MC, Guillermo Pérez D, López-Bayghen E, Gariglio P, Orozco E. Characterization of the 5'-flanking region of the EhPgp1 gene of multidrug resistance in Entamoeba histolytica. Arch Med Res 1997; 28 Spec No:62-3. [PMID: 9033013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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71
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Guillermo Pérez D, Gomez MC, López-Bayghen E, Gariglio P, Orozco E. Characterization of 5'-flanking sequence of the EhPgp5 gene of multidrug resistance in Entamoeba histolytica. Arch Med Res 1997; 28 Spec No:64-5. [PMID: 9033014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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72
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Mendoza L, Rangel LM, Garcia E, Sanchez T, Gariglio P, Orozco E. Detection of a human p53-like protein in E. histolytica. Arch Med Res 1997; 28 Spec No:17-8. [PMID: 9032996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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73
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López C, Gómez C, Pérez G, Flores E, Orozco E. Putative amplification of the EhPgp genes in Entamoeba histolytica emetine-resistant mutants. Arch Med Res 1997; 28 Spec No:66-8. [PMID: 9033015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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74
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García-Rivera G, Arroyo R, Mena R, Luna J, Orozco E. Involvement of the 112 kDa adhesin in Entamoeba histolytica phagocytosis. Arch Med Res 1997; 28 Spec No:166-7. [PMID: 9033056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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75
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Báez-Camargo M, Riverón AM, Delgadillo DM, Flores E, Sánchez T, Garcia-Rivera G, Orozco E. Entamoeba histolytica: gene linkage groups and relevant features of its karyotype. MOLECULAR & GENERAL GENETICS : MGG 1996; 253:289-96. [PMID: 9003315 DOI: 10.1007/pl00008595] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We identified some gene linkage groups in Entamoeba histolytica using a 4-M urea improved transversal alternating field electrophoresis (TAFE) method. Complex rosette-structured DNA molecules were found trapped along the gel lanes, explaining the fuzziness of the patterns. Using several episomal probes, including 16 S, 5.8 S, and 25 S ribosomal (r)Dna genes, an autonomous replication sequence (ARS), and EhVR1, we identified a complete ribosomal episome linkage group (CELG) at the 1.2-Mb position. Three other incomplete groups were found: IELG-1, formed by EhVR1, 16 S, 5.8 S, and 25 S genes; IELG-2 formed by EhVR1, 16 S and 25 S; and IELG-3 formed only by 5.8 S. Ehadh3, Ehpfo, and Ehredox genes migrated at the 1.8-Mb position, forming the non-ribosomal linkage group, NRLG-1.8, while the Ehenl-1 gene migrated at 1.6 Mb forming the NRLG-1.6 group. Ehhk was located at 1.2, 0.8, and 0.17 Mb in three different groups: NRLG-1.2, IELG-3-0.8, and NRLG-0.17. Putative lineal chromosomes were also identified using an heterologous telomeric probe. By in situ hybridization experiments, the rDNA and Ehhk genes were located in both nucleus and cytoplasm, while the Ehpfo and Ehredox genes were found mainly in the nucleus. We propose a model hypothezising that the 16 S and 25 S genes are in a linear molecule, duplicated in two inverted repeats, which may be looped out of the linear DNA to form an episome probably lacking or not the 5.8 S sequence, which could be added later by recombination.
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