RESUMEN
Sarcomas are an infrequent and heterogeneous group of neoplasia. Surgery with or without associated radiotherapy (RT) is the basic treatment for this type of tumour. To increase the therapeutic ratio (the index between cytotoxic effects in tumours and normal tissue complications with a certain dose of radiation), new advances are being investigated to increase local and distant control and to decrease the morbidity of the treatment. The aim of this review was to analyse the different strategies, based on technology and biology, which are being investigated to increase the therapeutic ratio of this disease.
Asunto(s)
Sarcoma/radioterapia , Braquiterapia , Quimioterapia Adyuvante , Extremidades , Humanos , Inhibidores de Proteínas Quinasas/uso terapéutico , Terapia de Protones , Radioterapia de Intensidad ModuladaRESUMEN
BACKGROUND: The purpose of this study is to assess the outcome of patients with Ewing sarcoma (EWS) of the bone and to identify prognostic factors. MATERIALS AND METHODS: Seventy-seven patients younger than 18 years old, diagnosed with EWS of the bone between 1979 and 2009, were analysed retrospectively. Four different protocols of chemotherapy were used successively. Local treatment consisted of surgery (N=32), radiotherapy (N=20) and a combination of both (N=19). RESULTS: The median age at diagnosis was 10 years old (range, 2-17) and the median follow-up for survivors 8.6 years (range, 1-18.8). Thirty-two relapses occurred (21 distant, 5 local and 6 both). The 2- and 5-year overall survival rates were 70% and 51%, respectively. Multivariate analysis showed four significant independent predictors for death: age ≥14 years old (HR: 5.06; p=0.019), lack of complete response (HR: 8.04; p<0.001), tumour volume ≥150 ml (HR: 2.21; p=0.045) and distant recurrences (HR: 1.45; p=0.001). CONCLUSIONS: Outcome of EWS of bone is influenced by many clinical and treatment-correlated variables. Criteria to stratify patients should include all the variables that have shown prognostic significance. The development of novel therapies should target these high-risk groups.
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Neoplasias Óseas/diagnóstico , Neoplasias Óseas/mortalidad , Sarcoma de Ewing/diagnóstico , Sarcoma de Ewing/mortalidad , Adolescente , Niño , Preescolar , Terapia Combinada/métodos , Femenino , Humanos , Masculino , Oncología Médica/métodos , Análisis Multivariante , Pronóstico , Recurrencia , Estudios Retrospectivos , Análisis de Supervivencia , Resultado del TratamientoRESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Fabiana species (Solanaceae family) extracts have long been used in Argentinean traditional medicine as anti-inflammatories, antiseptic, bone fractures and others diseases, but there is no scientific evidence which supports their use. AIM OF THE STUDY: The present study was conducted to evaluate the ability of aqueous and ethanolic extracts of four Fabiana species (Fabiana bryoides Phil., Fabiana punensis A.C. Arroyo, Fabiana densa J. Rèmy and Fabiana patagonica Speg.) to inhibit key enzymes in inflammatory processes, free radical scavenging properties and genotoxic effects. MATERIALS AND METHODS: HPLC-DAD of aqueous and ethanolic extracts from four Fabiana species was established. All Fabiana extracts were evaluated on their ability to inhibit hyaluronidase and lipoxygenase enzymes to assess their activity against inflammatory mediators. Antioxidant capacity was determined using the 2,2'-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging assays and ß-carotene-linolenic acid assay. Genotoxicity was evaluated by the Ames assay. RESULTS: The results indicated that the chromatographic patterns of four Fabiana species were different in quantity and absorption intensity of peaks. The alcoholic extract of Fabiana punensis was the most active scavenger of DPPH and ABTS(+) radicals (SC(50) values of 3.85 ± 0.24 and 2.56 ± 0.10 µgGAE/mL, respectively). Fabiana patagonica extracts exhibited the highest peroxyl radical scavenging activity compared with the other three taxa (IC(50) values between 1.00 ± 0.04 and 4.46 ± 0.40 µg GAE/mL for all extracts) and anti-lipoxygenase activity with IC(50) values between 12.5 and 15.5 µg GAE/mL. The absence of mutagenicity indicates that the DNA does not seem to be a relevant target for these extracts. Fabiana bryoides ethanolic extract showed an interesting effect: it inhibited spontaneous mutagenesis, which could be considered as an antimutagenic effect in the TA98 (+S9) and TA100 (+S9/-S9) strains. The potency differences found between the species could be consequence of the different phytochemical pattern observed by HPLC. CONCLUSIONS: The inhibitory effects on lipoxygenase and hyaluronidase, free radical scavenging activities and lack of genotoxicity of Fabiana extracts may support the folk use of Fabiana punensis, Fabiana patagonica, Fabiana bryoides and Fabiana densa as inhibitor of inflammatory mediators.
Asunto(s)
Antiinflamatorios/farmacología , Antimutagênicos/farmacología , Etanol/química , Depuradores de Radicales Libres/farmacología , Extractos Vegetales/farmacología , Solanaceae , Solventes/química , Agua/química , Antiinflamatorios/química , Antiinflamatorios/aislamiento & purificación , Antiinflamatorios/toxicidad , Antimutagênicos/química , Antimutagênicos/aislamiento & purificación , Antimutagênicos/toxicidad , Argentina , Benzotiazoles , Compuestos de Bifenilo/química , Cromatografía Líquida de Alta Presión , Daño del ADN , ADN Bacteriano/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Etnofarmacología , Depuradores de Radicales Libres/química , Depuradores de Radicales Libres/aislamiento & purificación , Depuradores de Radicales Libres/toxicidad , Hialuronoglucosaminidasa/antagonistas & inhibidores , Hialuronoglucosaminidasa/metabolismo , Cinética , Inhibidores de la Lipooxigenasa/farmacología , Medicina Tradicional , Picratos/química , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/toxicidad , Plantas Medicinales , Salmonella typhimurium/efectos de los fármacos , Salmonella typhimurium/genética , Solanaceae/química , Ácidos Sulfónicos/química , Tiazoles/química , Ácido alfa-Linolénico/química , beta Caroteno/químicaRESUMEN
The antimicrobial activity of samples of Northern Argentine propolis (Tucumán, Santiago del Estero and Chaco) against phytopathogenic bacteria was assessed and the most active samples were identified. Minimal inhibitory concentration (MIC) values were determined by agar macrodilution and broth microdilution assays. Strong antibacterial activity was detected against Erwinia carotovora spp carotovora CECT 225, Pseudomonas syringae pvar tomato CECT 126, Pseudomonas corrugata CECT 124 and Xanthomonas campestris pvar vesicatoria CECT 792. The most active propolis extract (Tucumán, T1) was selected to bioguide isolation and identified for antimicrobial compound (2',4'-dihydroxychalcone). The antibacterial chalcone was more active than the propolis ethanolic extract (MIC values of 0.5-1 µg ml(-1) and 9.5-15 µg ml(-1), respectively). Phytotoxicity assays were realized and the propolis extracts did not retard germination of lettuce seeds or the growth of onion roots. Propolis solutions applied as sprays on tomato fruits infected with P. syringae reduced the severity of disease. Application of the Argentine propolis extracts diluted with water may be promising for the management of post harvest diseases of fruits.
Asunto(s)
Antibacterianos/farmacología , Chalconas/farmacología , Pectobacterium carotovorum/efectos de los fármacos , Enfermedades de las Plantas/microbiología , Própolis/química , Pseudomonas syringae/efectos de los fármacos , Xanthomonas campestris/efectos de los fármacos , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Argentina , Chalconas/química , Chalconas/aislamiento & purificación , Lactuca/efectos de los fármacos , Lactuca/crecimiento & desarrollo , Solanum lycopersicum/microbiología , Pruebas de Sensibilidad Microbiana , Cebollas/efectos de los fármacos , Cebollas/crecimiento & desarrollo , Pectobacterium carotovorum/patogenicidad , Raíces de Plantas/efectos de los fármacos , Pseudomonas syringae/patogenicidad , Semillas/efectos de los fármacos , Xanthomonas campestris/patogenicidadRESUMEN
AIM: The plant species reported here are traditionally used in the "Puna" or "Altiplano" of Argentina for ailments related to bacterial infections. The aim of this study was to evaluate their antimicrobial properties against a panel of sensitive and multi-resistant gram-positive and gram-negative bacteria. MATERIALS AND METHODS: The antimicrobial activity of tinctures and aqueous extracts (Baccharis boliviensis, Chiliotrichiopsis keidelii, Chuquiraga atacamensis, Fabiana bryoides, Fabiana densa, Fabiana punensis, Frankenia triandra, Parastrephia lucida, Parastrephia lepidophylla, Parastrephia phyliciformis, Tetraglochin cristatum) was determined using the agar macrodilution and broth microdilution methods recommended by the Clinical and Laboratory Standards Institute (CLSI, formerly NCCLS). The antibiotic resistant clinical strains were isolated from nosocomial infection in human lesions of skin and soft parts. RESULTS: The ethanolic extracts of 11 plant species inhibited the growth of one or more of the following strains: Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Enterobacter cloacae, Morganella morganii, Pseudomonas aeruginosa. Ethanol extracts (tinctures) of aerial parts of Baccharis, Fabiana and Parastrephia showed the highest levels of antibacterial activity on methicillin, oxacillin and gentamicin resistant Staphylococcus with MIC values from 20 to 150 microg/ml. Baccharis boliviensis and Fabiana bryoides were more active than the other plant species on Enterococcus faecalis with different phenotype. The most interesting activity on multi-resistant gram-negative strains was obtained from Chuquiraga atacamensis. Parastrephia species showed activity against Enterobacter cloacae, Pseudomonas aeruginosa and Proteus mirabilis. The ethanolic extracts exhibited stronger activity and broader spectrum of action than aqueous extracts. The extracts were bactericidal in most cases. CONCLUSIONS: The presence of antibacterial activity in Puna plant extracts against multi-resistant bacteria give support to their traditional use for treating conditions associated with microorganisms in humans and animals and consequently seems promising for the treatment of multi-resistant bacteria.
Asunto(s)
Antiinfecciosos/farmacología , Bacterias/efectos de los fármacos , Farmacorresistencia Bacteriana/efectos de los fármacos , Plantas Medicinales/química , Antiinfecciosos/química , Argentina , Cromatografía en Capa Delgada , Medios de Cultivo , Etnofarmacología , Medicina Tradicional , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Fenoles/química , Fenoles/farmacología , Extractos Vegetales/química , Extractos Vegetales/farmacologíaRESUMEN
The localization of invertase, a key enzyme in plant carbohydrate metabolism, has been established in several higher plants, but there are no reports of it in ferns. The aim of the present work was to establish the localization of the previously reported acid invertase activity of Pteris deflexa in fronds tissues and to compare the findings with invertase localization in higher plants. Acid invertase, localized by immuno-histochemical and histochemical techniques on fresh tissues, was evident in vascular tissue, mainly in phloem. It was also detected in parenchymatic, sclerenchymatic and epidermic cells of petiole, rachis and rachis branches as well as in veins of leaf blades. Our results demonstrate that P. deflexa acid invertase localization is the same to that of higher plants. Hence, potential roles of the fern enzyme in relation to the storage and utilization of sucrose and to control carbon flux could be the same of those proposed to higher plants.
Asunto(s)
Hojas de la Planta/enzimología , Pteris/enzimología , beta-Fructofuranosidasa/metabolismo , Inmunohistoquímica , Floema/química , Floema/enzimología , Pteris/química , beta-Fructofuranosidasa/análisisRESUMEN
Leukemia-associated antigens such as proteins encoded by MAGE genes might provide tools for immunotherapy of leukemia. Positive and negative results of MAGE-A gene expression in hematological malignancies have been reported. This led us to study MAGE-A gene expression in human leukemias using RT-PCR. Among 115 leukemias from various subtypes, 14/34 (41.17%) AML were positive for one of the three genes analyzed (MAGE-A1 1/32; MAGE-A3 10/32; MAGE-B2 3/12). Expression was also detected in 23/76 (30.26%) B-cell ALL patients (MAGE-A1 2/53; MAGE-A3 20/53; MAGE-B2 1/32). One of these patients expressed both MAGE-A1 (weak signal) and -A3 (strong signal) genes. Other patient with CML were positive for MAGE-B2 (1/5, 20%). MAGE-A3 expression data were corroborated by real time RT-PCR through determination of MAGE-A3 transcript levels. We concluded that the MAGE-A3 gene is expressed at the mRNA level in a proportion of human leukemias.
Asunto(s)
Antígenos de Neoplasias/genética , Leucemia/genética , Proteínas de Neoplasias/genética , ARN Mensajero/genética , Transcripción Genética , Adulto , Antígenos de Neoplasias/sangre , Secuencia de Bases , Cartilla de ADN , Femenino , Amplificación de Genes , Humanos , Leucemia/sangre , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Leucemia Mieloide Aguda/genética , Masculino , Persona de Mediana Edad , Proteínas de Neoplasias/sangre , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
The wide geographical distribution of Triatoma dimidiata, one of the three major vectors of Chagas disease, ranges from Mexico to northern Peru. Since this species occupies a great diversity of artificial and natural ecotopes, its eradication is extremely difficult. In order to assist control efforts, we used chromosome analyses and DNA amount as taxonomic markers to study genetic variability in populations of T. dimidiata from Mexico, Guatemala, El Salvador and Colombia. We differentiated three groups or cytotypes defined by characteristic chromosome C-banding patterns and genome size measured by flow cytometry. The three cytotypes are restricted to different geographic locations. Cytotype 1 occurs in Mexico (excluding Yucatán), Guatemala (excluding Petén), El Salvador and Colombia. Cytotype 2 occurs in Yucatán and cytotype 3 occurs in Petén. Cytotype 1, commonly associated with domestic and peridomestic environments but also inhabiting sylvatic ecotopes, is the most widespread and with major epidemiological significance. In contrast, the Yucatán cytotype inhabits wild ecotopes but increasingly enters houses, while the Petén cytotype appears exclusively sylvatic. We suggest that these cytotypes represent cryptic species of T. dimidiata with different epidemiological relevance as Chagas disease vectors. Poor ability to colonize human dwellings, together with their restricted geographic distribution, indicate that the Yucatán and Petén putative species probably have much less epidemiological significance than cytotype 1. Thus, the genetic markers we describe are powerful tools to differentiate cryptic species in T. dimidiata with different epidemiological significance, contributing to planning the most effective control measures.
Asunto(s)
Enfermedad de Chagas/transmisión , Cromosomas/genética , Insectos Vectores/genética , Triatoma/genética , Animales , Enfermedad de Chagas/genética , Colombia , El Salvador , Citometría de Flujo/métodos , Marcadores Genéticos/genética , Variación Genética/genética , Genoma de los Insectos/genética , Guatemala , Humanos , Cariotipificación/métodos , México , Especificidad de la Especie , Triatoma/clasificaciónRESUMEN
The geographic variation in the cuticular hydrocarbon pattern among 11 populations of Triatoma dimidiata Latreille (Hemiptera: Reduviidae: Triatominae) from different regions of Mexico and Guatemala, was studied using capillary gas chromatography. T. dimidiata populations were differentiated based on the relative amounts of 71 hydrocarbon components. Insect population classification was mostly in agreement with their geographical vicinity; Mexican populations from the Yucatan peninsula grouped together with those from northern Guatemala, insects from the Mexican Gulf coast states were closely related to those collected from northern Oaxaca, and to a lesser extent, to insects from Chiapas. Insects from southern Oaxaca were clustered together with those from southern Guatemala. All these populations were clearly separated from Guatemalan specimens collected in caves from Alta Verapaz.
Asunto(s)
Hidrocarburos/análisis , Insectos Vectores/química , Triatoma/química , Animales , Cromatografía de Gases , Análisis por Conglomerados , Análisis Discriminante , Geografía , Guatemala , Insectos Vectores/clasificación , México , Triatoma/clasificaciónRESUMEN
Triatoma dimidiata is one of the major vectors of Chagas disease in Latin America. Its range includes Mexico, all countries of Central America, Colombia, and Ecuador. In light of recent genetic analysis suggesting that the possible origin of this species is the Yucatan peninsula, we have analyzed populations from the state of Yucatan, San Luis Potosi, and Veracruz in Mexico, and a population from the southern region of the Yucatan peninsula located in Northern Guatemala, the region of El Peten. Classical morphometry including principal component, discriminant, sexual dimorphism, and wing asymmetry was analyzed. San Luis Potosi and Veracruz populations were indistinguishable while clearly separate from Yucatan and Peten populations. Despite important genetic differences, Yucatan and Peten populations were highly similar. Yucatan specimens were the smallest in size, while females were larger than males in all populations. Only head characters were necessary to distinguish population level differences, although wing fluctuating asymmetry was present in all populations. These results are discussed in light of recent findings suggesting genetic polymorphism in most populations of Triatoma dimidiata south of Chiapas to Ecuador.
Asunto(s)
Insectos Vectores/anatomía & histología , Triatoma/anatomía & histología , Alas de Animales/anatomía & histología , Animales , Femenino , Guatemala , Masculino , México , Análisis de Componente Principal , Caracteres SexualesRESUMEN
Triatoma dimidiata is one of the major vectors of Chagas disease in Latin America. Its range includes Mexico, all countries of Central America, Colombia, and Ecuador. In light of recent genetic analysis suggesting that the possible origin of this species is the Yucatan peninsula, we have analyzed populations from the state of Yucatan, San Luis Potosi, and Veracruz in Mexico, and a population from the southern region of the Yucatan peninsula located in Northern Guatemala, the region of El Peten. Classical morphometry including principal component, discriminant, sexual dimorphism, and wing asymmetry was analyzed. San Luis Potosi and Veracruz populations were indistinguishable while clearly separate from Yucatan and Peten populations. Despite important genetic differences, Yucatan and Peten populations were highly similar. Yucatan specimens were the smallest in size, while females were larger than males in all populations. Only head characters were necessary to distinguish population level differences, although wing fluctuating asymmetry was present in all populations. These results are discussed in light of recent findings suggesting genetic polymorphism in most populations of Triatoma dimidiata south of Chiapas to Ecuador.
Asunto(s)
Animales , Masculino , Femenino , Insectos Vectores/anatomía & histología , Triatoma/anatomía & histología , Alas de Animales/anatomía & histología , Guatemala , México , Análisis de Componente Principal , Caracteres SexualesRESUMEN
Chagas disease caused by infection with Trypanosoma cruzi Chagas (Kinetoplastida: Trypanosomatidae) is widespread in Mexico, transmitted by various triatomine bugs (Hemiptera: Reduviidae). The only domestic vector in Cuernavaca (population 650 000) is Triatoma pallidipennis (Ståhl) with T. cruzi seroprevalence ranging from 1% to 9% in the resident human population. We surveyed possible risk factors for T. pallidipennis infestation at Cuernavaca (altitude 1200-2200 m) on south-western slopes of the Sierra Madre Occidental. This metropolitan area (with five administrative counties) has rapid urbanization, forested environs and proliferation of 'weekend housing' for visitors from Mexico City, 60 km to the north. To assess factors associated with T. pallidipennis infestation, we first stratified Cuernavaca by altitude and by socio-economic status of population catchment units (PCUs). Within each PCU, one to three blocks were chosen for cluster sampling (three houses/block) and information about Chagas disease was distributed. After obtaining signed consent from householders, representative houses were routinely and opportunistically inspected for T. pallidipennis and surveyed for demographic, economic, physical and other potential risk factors. Of the 1129 houses assessed, T. pallidipennis was found in 4.1% (range 3.0-6.8% per county) and the T. cruzi infection rate was approximately 50% in bugs. Rates of house infestation in poor PCUs were double those in higher socio-economic strata (odds ratio 2.12, confidence interval 1.03-4.3), with >4-fold greater crowding index of T. pallidipennis. The bug density index was inversely correlated with PCU altitude and socio-economic category (altitude of homes being associated with prosperity), while the bug colonization index (presence of nymphs indicating breeding) did not vary significantly across the PCU categories, but did vary according to altitude. Multivariate regression analysis showed that the most significant risk factors associated with T. pallidipennis infestation were lower altitude (linked with lower socio-economic status), garden area >80 m(2), dogs at liberty to enter the house, occurrence of squirrels and opossums around the house, presence of pigs in the surrounding area and having at least one of the adjacent lots empty (unconstructed). Householders who had received information about Chagas disease comprised 33% from infested houses (14/42) but only 15% from non-infested houses (148/984). Hence, the awareness of Chagas disease was significantly associated with having a bug-free house (P < 0.01). When shown specimens of T. pallidipennis, the proportions of householders who recognized them were 78% from infested houses but only 29% of those with uninfested houses. Given the low infestation rates and the high capacity of the population to act appropriately once they have received information regarding this disease and its vector, relevant health education is expected to have a significant impact on triatomine control in this metropolitan area.
Asunto(s)
Enfermedad de Chagas/transmisión , Insectos Vectores , Triatoma , Altitud , Animales , Vivienda , México , Factores de Riesgo , Factores SocioeconómicosRESUMEN
BACKGROUND: Human papillomavirus 16 (HPV16) has a number of variants, each with a different geographic distribution and some that are associated more often with invasive neoplasias. We investigated whether the high incidence of cervical cancer in Mexico (50 cases per 100 000 women) may be associated with a high prevalence of oncogenic HPV16 variants. METHODS: Cervical samples were collected from 181 case patients with cervical cancer and from 181 age-matched control subjects, all from Mexico City. HPV16 was detected with an E6/E7 gene-specific polymerase chain reaction, and variant HPV classes and subclasses were identified by sequencing regions of the E6 and L1/MY genes. Clinical data and data on tumor characteristics were also collected. All statistical tests were two-sided. RESULTS: HPV16 was detected in cervical scrapes from 50.8% (92 of 181) of case patients and from 11% (20 of 181) of control subjects. All HPV16-positive samples, except one, contained European (E) or Asian-American (AA) variants. AA and E variants were found statistically significantly more often in case patients (AA = 23.2% [42 of 181]; E = 27.1% [49 of 181]) than in control subjects (AA = 1.1% [two of 181]; E = 10% [18 of 181]) (P<.001 for case versus control subjects for either E or AA variants, chi2 test). However, the frequency of AA variants was 21 times higher in cancer patients than in control subjects, whereas that ratio for E variants was only 2.7 (P =.006, chi2 test). The odds ratio (OR) for cervical cancer associated with AA variants (OR = 27.0; 95% confidence interval [CI] = 6.4 to 113.7) was higher than that associated with E variants (OR = 3.4; 95% CI = 1.9 to 6.0). AA-positive case patients (46.2 +/- 12.5 years [mean +/- standard deviation]) were 7.7 years younger than E-positive case patients (53.9 +/- 12.2 years) (P =.004, Student's t test). AA variants were associated with squamous cell carcinomas and adenocarcinomas, but E variants were associated with only squamous cell carcinomas (P =.014, Fisher's exact test). CONCLUSIONS: The high frequency of HPV16 AA variants, which appear to be more oncogenic than E variants, might contribute to the high incidence of cervical cancer in Mexico.
Asunto(s)
Papillomaviridae/clasificación , Papillomaviridae/genética , Infecciones por Papillomavirus/complicaciones , Infecciones Tumorales por Virus/complicaciones , Neoplasias del Cuello Uterino/epidemiología , Neoplasias del Cuello Uterino/virología , Adenocarcinoma/epidemiología , Adenocarcinoma/virología , Adulto , Anciano , Asia/etnología , Pueblo Asiatico/genética , Carcinoma de Células Escamosas/epidemiología , Carcinoma de Células Escamosas/virología , Estudios de Casos y Controles , ADN Viral/genética , Europa (Continente)/etnología , Femenino , Variación Genética , Humanos , Incidencia , México/epidemiología , Persona de Mediana Edad , Oportunidad Relativa , Infecciones por Papillomavirus/virología , Reacción en Cadena de la Polimerasa , Prevalencia , Análisis de Secuencia de ADN , Infecciones Tumorales por Virus/virología , Población Blanca/genéticaRESUMEN
Triatoma barberi, T. dimidiata, T. longipennis, T. pallidipennis and T. picturata, all key Chagas disease vectors in Mexico, were analysed by multilocus enzyme electrophoresis (MLEE) at 17 putative loci. The majority of insect specimens studied were collected from domestic and peridomestic structures from multiple geographic locations while others were collected from sylvatic areas. T. barberi was the least polymorphic species (P(0.95)=0.18), with polymorphism rates of the other species ranging from 0.29 to 0.50. T. barberi, a member of the protracta complex, clustered apart from the other studied species by Nei's genetic distance with >1.36, and at least eight loci were found to be diagnostic for this species. T. dimidiata was more related to T. longipennis, T. pallidipennis and T. picturata (phyllosoma complex) than to T. barberi, with a genetic distance averaging 0.36 with the phyllosoma complex species. In contrast, the genetic distances between the three phyllosoma complex species were not significantly different from zero, and there were no species-specific loci differentiating among them. The results strongly support the grouping of these three species in one complex, separate from the two other species studied.
Asunto(s)
Enfermedad de Chagas/transmisión , Variación Genética , Triatoma/enzimología , Triatoma/genética , Animales , Isoenzimas/genética , México , Filogenia , Polimorfismo Genético , Especificidad de la Especie , Trypanosoma cruziRESUMEN
Mexico has 18 species of Triatomine bugs (Hemiptera: Reduviidae) reported to be vectors of Trypanosoma cruzi. Chagas Disease is widespread in Mexico, with up to 3.5% seropositivity of human transfusion blood. The State of Oaxaca has the longest history of endemic Chagas Disease, based on acute and chronic case reports, and of entomological surveys in the country. However, the State health care services need more information on current risks of vector transmission. In order to identify and characterize areas of transmission in Oaxaca and to stratify the vector potential, the distribution of domestic Triatominae was surveyed during 1996-98 in collaboration with the primary health care services and local communities. Villages were studied in 11% of 570 municipalities in Oaxaca. Eight triatomine species were found in domestic and peri-domestic habitats: Triatoma barberi Usinger, T. bolivari Carcavallo et al., T. dimidiata (Latreille), T. mazzottii Usinger, T. nitida Usinger, T. pallidipennis (Stal), T. phyllosoma (Burmeister) and Rhodnius prolixus Stal. For each triatomine species in Oaxaca, the range of distribution and habitat characteristics are described. Habitat partitioning, principally based on altitude and mean annual precipitation, limited the overlap of distribution between species. Relatively consistent altitude of human settlements facilitates the dispersion of individual species within microregions. Entomological indices of house infestation were used to estimate that approximately 50% of the human population (1,874,320 inhabitants) would be at risk of vector transmission, with a minimum of 134,320 infected people and 40,280 chronic cases of Chagas Disease currently in Oaxaca.
Asunto(s)
Enfermedad de Chagas/transmisión , Triatominae , Adolescente , Animales , Humanos , México/epidemiología , Características de la Residencia , Factores Socioeconómicos , Trypanosoma cruzi/patogenicidadRESUMEN
This work describes a new invertase proteinaceous inhibitor from Cyphomandra betacea Sendt. (tomate de arbol) fruits. The proteinaceous inhibitor was isolated and purified from a cell wall preparation. The pH stability, kinetics of the inhibition of the C. betacea invertase, inhibition of several higher plant invertases and lectin nature of the inhibitor were studied. The inhibitor structure involves a single polypeptide (Mr = 19000), as shown by gel filtration and SDS-PAGE determinations. N-terminal aminoacid sequence was determined. The properties and some structural features of the inhibitor are compared with the proteinaceous inhibitors from several plant species (Beta vulgaris L., Ipomoea batatas L. and Lycopersicon esculentum Mill.). All these inhibitors share lectinic properties, some common epitopes, some aminoacid sequences and a certain lack of specificity towards invertases of different species, genera and even plant family. In consequence, the inhibitors appear to belong to the same lectin family. It is now known that some lectins are part of the defence mechanism of higher plants against fungi and bacteria and this is a probable role of the proteinaceous inhibitors.
Asunto(s)
Frutas/química , Glicósido Hidrolasas/antagonistas & inhibidores , Relación Dosis-Respuesta a Droga , Electroforesis en Gel de Poliacrilamida , Inhibidores Enzimáticos/aislamiento & purificación , Inhibidores Enzimáticos/farmacología , Glicósido Hidrolasas/aislamiento & purificación , Concentración de Iones de Hidrógeno , Lectinas/aislamiento & purificación , Lectinas/farmacología , Peso Molecular , Lectinas de Plantas , Proteínas de Plantas/antagonistas & inhibidores , Proteínas de Plantas/aislamiento & purificación , Proteínas de Plantas/farmacología , Sacarosa/metabolismo , beta-FructofuranosidasaRESUMEN
Human-papillomavirus (HPV)-E2 protein is involved in gene-expression regulation and replication of HPV genome. Disruption of the E2 gene during viral integration has been proposed as a mechanism of tumoral progression, since the expression of E6/E7 viral oncogenes is allowed. However, retention of E1/E2 genes and high viral amplification are frequently found in HPV16-positive carcinomas of some populations. In this study, we investigated whether retention of E1/E2 and viral amplification are associated with particular HPV16 E2 variants in cervical carcinomas. HPV16 detection, E1/E2 integrity and viral amplification were explored by Southern blot in 123 cervical carcinomas. HPV16 variants were identified by Southern blot and by sequencing E6, L1/MY and E2 regions. Of 46 HPV16-positive tumors, 34 were positive for E1/E2 and 14 of them showed a variant restriction pattern by mutations in E2. All 14 were Asian-American (AA) variants and, of 11 sub-classified, 6 were AA-a and 5 AA-c. Two E1/E2-negative tumors also contained the AA-c variant, while the remaining HPV16-positive tumors contained only European variants. The E2 gene of AA variants showed 24 mutations, 19 identical in both sub-classes. The 24 mutations were distributed throughout the entire gene and 19 result in 18 amino-acid changes. The AA variants were associated with E1/E2-positive carcinomas with more than 50 viral copies/cell (p = 0.035). The association of Asian-American E2 variants with retention of E1/E2 suggests that E2 variation may be an alternative mechanism de-regulating the expression of viral oncogenes.
Asunto(s)
Proteínas de Unión al ADN , Proteínas Oncogénicas Virales/genética , Papillomaviridae/genética , Infecciones por Papillomavirus/genética , Proteínas Represoras , Infecciones Tumorales por Virus/genética , Neoplasias del Cuello Uterino/virología , Sustitución de Aminoácidos , Asiático , Southern Blotting , Proteínas de la Cápside , Análisis Mutacional de ADN , ADN Viral/genética , Femenino , Dosificación de Gen , Humanos , Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/etnología , Mutación Puntual/genética , Infecciones Tumorales por Virus/etnología , Neoplasias del Cuello Uterino/genéticaRESUMEN
Three fractions with invertase activity (beta-D-fructofuranoside fructohydrolase, EC 3.2.1.26) were isolated from mature Solanum tuberosum tubers: acid soluble invertase, invertase I and invertase II. The first two invertases were purified until electrophoretic homogeneity. They are made by two subunits with an apparent M(r) value of 35,000 and their optimal pH is 4.5. Invertase I was eluted from cell walls with ionic strength while invertase II remained tightly bound to cell walls after this treatment. This invertase was solubilized by enzymatic cell wall degradation (solubilized invertase II). Their K(m)s are 28, 20, 133 and 128 mM for acid soluble invertase, invertase I, invertase II and solubilized invertase II, respectively. Glucose is a non-competitive inhibitor of invertase activities and fructose produces a two site competitive inhibition with interaction between the sites. Bovine serum albumin produces activation of the acid soluble invertase and invertase I while a similar inhibition by lectins and endogenous proteinaceous inhibitor from mature S. tuberosum tubers was found. Invertase II (tightly bound to the cell walls) shows a different inhibition pattern. The test for reassociation of the acid soluble invertase or invertase I on cell wall, free of invertase activity, caused the reappearance of all invertase forms with their respective solubilization characteristics and molecular and kinetic properties. The invertase elution pattern, the recovery of cell wall firmly bound invertase and the coincidence in the immunological recognition, suggest that all three invertases may be originated from the same enzyme. The difference in some properties of invertase II and solubilized invertase II from the other two enzymes would be a consequence of the enzyme microenvironment in the cell wall or the result of its wall binding.
Asunto(s)
Pared Celular/enzimología , Glicósido Hidrolasas/metabolismo , Solanum tuberosum/enzimología , Anticuerpos/inmunología , Western Blotting , Catálisis , Inhibidores Enzimáticos/metabolismo , Glicósido Hidrolasas/antagonistas & inhibidores , Glicósido Hidrolasas/aislamiento & purificación , Concentración de Iones de Hidrógeno , Cinética , Lectinas/metabolismo , Lectinas de Plantas , Especificidad por Sustrato , beta-FructofuranosidasaRESUMEN
En una muestra de 300 trabajadores de tres empresas cultivadoras de rosas del norte de la sabana de Santafé de Bogotá, se intentó correlacionar el clima organizacional con el estado de salud de sus trabajadores con base en datos de 1992. Para ingresar a la investigación y con el fin de controlar sesgos las empresas debían cumplir los siguientes requisitos: Estar dedicados a la misma actividad económica, estar localizadas en la misma área geográfica, tener un numero similar de empleados y ser ejecutoras de programas de salud ocupacional. El clima organizacional fue medido mediante una encuesta personal, tomada de una tesis de grado de la facultad de ingeniería industrial de la Universidad de los Andes, realizada por los Dres Escobar A, y Rodríguez C, la cual lo califica en ocho dimensiones que son: recompensa, normas de la organización, claridad organizacional, responsabilidad, espíritu de grupo, conformidad, subsistencia y seguridad. El estado de salud fué determinado mediante los análisis de accidentalidad, ausentismo y morbilidad, con datos recolectados directamente por las investigadoras de los departamentos de sistemas y personal, del 1º de Enero de 1992 al 31 de Diciembre de 1992. En la empresa denominada Nº1 no se permitió por parte de las directivas la realización de algunas preguntas relacionadas con las dimensiones subsistencia y seguridad. Lo mismo ocurrió para la dimensión subsistencia en la empresa denominada Nº3. Esto conlleva a una medición parcial del clima organizacional lo cual altera el resultado final obtenido
Asunto(s)
Estado de Salud , Grupos ProfesionalesRESUMEN
Colonization of the intestine with Campylobacter jejuni was followed longitudinally from birth in a cohort of 75 rural children with fecal cultures taken every fortnight and every time they had diarrhea. Only 25% of children initially colonized with C. jejuni during the first year of life, and 12% of children initially colonized during the second had diarrhea. The age at which a child was initially infected with C. jejuni was not a risk factor in relation with presence of disease. A higher illness-to-infection ratio (P less than 0.05) was found during subsequent colonization with C. jejuni when initial infection was associated with diarrhea. Risk of diarrhea during initial or subsequent colonization with C. jejuni was not related with the production of cholera-like enterotoxin, a cytotoxic active on HeLa cells or with adhesive ability to HEp-2 cells by the infecting strains.