RESUMEN

Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by a heterogeneous clinical picture that makes the diagnosis and follow-up of these patients difficult. This study aimed to identify correlations between clinical, immunological, and genetic biomarkers and clinical manifestations in SLE. A retrospective study of data from medical records and immunological and genetic studies of SLE patients in Paraguay was carried out. A descriptive analysis was performed based on the type of variable. Human leukocyte antigen (HLA) allele frequencies (DPA1, DPB1, DQA1, DQB1, and DRB1) were calculated, and univariate logistic regression analyses were performed between each of the explanatory variables and the presence or absence of each phenotype. Odds ratios, 95% confidence intervals, and p values were recorded. Associations with p<0.05 were considered statistically significant. 104 SLE patients were included: 86% were female, with a mean age of 32.80±10.36 years. An association was identified between anti-double stranded DNA (anti-dsDNA) and the presence of the renal phenotype and between anti-dsDNA and the absence of the joint and hematological phenotypes. Immunoglobulin M isotype rheumatoid factor was associated with the absence of a renal phenotype. HLA-DQB1*02:02 and HLA-DRB1*07:01 were associated with the cutaneous phenotype. An association was identified between age at disease onset over 30 years and the presence of the joint phenotype. No other associations were identified. Potential clinical, immunological, and genetic biomarkers of phenotypes have been identified in SLE Paraguayan patients.

Asunto(s)

Lupus Eritematoso Sistémico , Adulto , Femenino , Humanos , Masculino , Adulto Joven , Alelos , Biomarcadores , Predisposición Genética a la Enfermedad , Cadenas HLA-DRB1/genética , Lupus Eritematoso Sistémico/diagnóstico , Lupus Eritematoso Sistémico/etnología , Lupus Eritematoso Sistémico/genética , Paraguay/epidemiología , Fenotipo , Estudios Retrospectivos , Persona de Mediana Edad

RESUMEN

The study of the composition of the intestinal flora is important to the health of the host, playing a key role in maintaining intestinal homeostasis and the evolution of the immune system. For these studies, various universal primers of the 16S rDNA gene are used in microbial taxonomy. Here, we report an evaluation of 5 universal primers to explore the presence of microbial DNA in colon biopsies preserved in RNAlater solution. The DNA extracted was used for the amplification of PCR products containing the variable (V) regions of the microbial 16S rDNA gene. The PCR products were studied by restriction fragment length polymorphism (RFLP) analysis and DNA sequence, whose percent of homology with microbial sequences reported in GenBank was verified using bioinformatics tools. The presence of microbes in the colon of rats was quantified by the quantitative PCR (qPCR) technique. We obtained microbial DNA from rat, useful for PCR analysis with the universal primers for the bacteria 16S rDNA. The sequences of PCR products obtained from a colon biopsy of the animal showed homology with the classes bacilli (Lactobacillus spp) and proteobacteria, normally represented in the colon of rats. The proposed methodology allowed the attainment of DNA of bacteria with the quality and integrity for use in qPCR, sequencing, and PCR-RFLP analysis. The selected universal primers provided knowledge of the abundance of microorganisms and the formation of a preliminary test of bacterial diversity in rat colon biopsies.

Asunto(s)

Colon/microbiología , Microbioma Gastrointestinal , Tipificación Molecular/métodos , ARN Ribosómico 16S/genética , Animales , Bacterias/genética , Cartilla de ADN/genética , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , Genes Bacterianos , Masculino , Reacción en Cadena de la Polimerasa/métodos , Polimorfismo de Longitud del Fragmento de Restricción , Ratas , Análisis de Secuencia de ADN

RESUMEN

Gastric cancer is one of the main causes of death in the world. In Venezuela, gastric tumors represent 37% of all malignant tumors of the digestive system, but only 1,6% to 3,1% of these cases are lymphoepithelioma-like carcinoma. Synchronous neoplastic lesions are also rare. The clinical case presented herein, a man with two synchronous tumor lesions, is the first of its kind in this country. Despite their incipient aspect, the histologic study reported two malignant tumors of epithelial origin: well-differentiated adenocarcinoma and lymphoepithelioma-like carcinoma.

Asunto(s)

Adenocarcinoma/patología , Carcinoma/patología , Neoplasias Gástricas/patología , Adenocarcinoma/cirugía , Carcinoma/cirugía , Endoscopía , Gastrectomía , Mucosa Gástrica/patología , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Neoplasias Gástricas/cirugía , Venezuela

RESUMEN

Los monocitos/macrófagos constituyen las células diana para el virus dengue, activando linfocitos T, liberando citoquinas proinflamatorias como el Factor de Necrosis Tumoral alfa e Interferón gamma. El objetivo del estudio fue determinar TNF-α e IFN-γ en suero de pacientes dengue IgM positivo e IgM negativo, que concurrieron al Instituto de Investigaciones en Ciencias de la Salud, de febrero a abril 2007. Se realizó un estudio analítico en 163 sueros de pacientes con dengue, 143 IgM positivo y 20 IgM negativo, de ambos sexos con edad promedio de 30 y rango entre 18 a 70 años. El anticuerpo IgM para dengue y las citoquinas fueron determinados por ELISA de captura. En los 143 sueros dengue IgM positivo, el IFN-γ se detectó en 73% (104/143) con valores entre 558 y superiores a 2000 pg/ml y en el 27% (39/143) valores por debajo del punto de corte. Se encontró una diferencia estadísticamente significativa comparado con sueros dengue IgM negativo (p = < 0.005). El TNF-α se detectó en 24% (35/143) sueros IgM positivo, de los cuales 33 presentaron valores entre 45 a 176 pg/ml y 2 con valores superiores a 2000 pg/ml. No hubo significancia estadística comparando con sueros dengue IgM negativo (p = 0.26). Niveles elevados de IFN-γ y TNF-α podrían ser considerados marcadores de pronóstico para la progresión al dengue hemorrágico. Se debería tener en cuenta la potencial significancia terapéutica de estas citoquinas que podrían ayudar en las estrategias de inhibir o inducir perfiles de citoquinas adecuadas en respuesta al dengue.

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Monocytes/macrophages are target cells for dengue virus, taking part in the activation of T lymphocytes, releasing proinflammatory cytokines such as tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ). The objective of this study was to determine TNF-α and IFN-γ in sera of dengue patients with IgM positive and negative who attended the Instituto de Investigaciones en Ciencias de la Salud from February to April 2007. An analytical study was performed in 163 sera of dengue patients, 143 IgM positive and 20 IgM negative, men and women with an mean age of 30 years and a range from 18 to 70 years. The IgM antibody for dengue and the serum levels of cytokines were performed by capture ELISA. Serum levels of IFN-γ were detected in 73% (104/143) of the patients with dengue IgM positive, with values between 558 and higher than 2000 pg/ml, and in 27% (39/143) were below the cut-off value. A statistically significative difference was found when they were compared with dengue IgM negative sera (p=<0.005). TNF-α serum levels were detected in 24% (35/143) of the dengue IgM positive patients, 33 patients presented values between 45 and 176 pg/ml and 2 had values above 2000 pg/ml. No statistical significance was found when these values were compared with those of dengue IgM negative sera (p=0.26). IFN-γ and TNF-α high levels could be considered prognostic markers for progression to hemorrhagic dengue. The potential therapeutic significance of these cytokines should be considered as they could help in the strategies to inhibit or induce appropriate cytokine profiles in response to dengue virus.

Asunto(s)

Dengue , Dengue Grave

RESUMEN

El dengue es un grave problema de salud pública que no posee vacuna ni tratamiento específico. El método de diagnóstico más utilizado es el serológico, específicamente, la detección de anticuerpos IgM anti-dengue. Los antígenos virales utilizados en este método pueden ser preparados en cultivo de células de Aedes albopictus (C6/36). El objetivo de este trabajo fue el mantenimiento de los cuatro serotipos virales (D1 (RIO), D2 (RIO), D3 (H-87), D4 (BV)) en células C6/36 para la futura preparación de antígenos virales. Las células C6/36 fueron cultivadas en medio L-15 con 10% de SFB a 28ºC, e infectadas con 50 ml de cada uno de los serotipos virales por 5 a 7 días. Una vez confirmada la infección por inmunoflurescencia indirecta, los virus fueron titulados por la técnica de placa de lisis. Los títulos de los serotipos fueron D1 (RIO) (2,9 x 106 PFU/ml), D2 (RIO) (4,4 x107 PFU/ml), D3 (H87) (6,4 x 107 PFU/ml) y D4 (BV) (5,1 x106 PFU/ml). La producción de antígenos virales es de gran importancia dado que los mismos pueden ser utilizados en diversos métodos diagnósticos.

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Dengue is a serious public health problem that has neither vaccine nor specific treatment. Serology is the most frequently used diagnosis method, specifically the anti-dengue IgM detection. The viral antigens employed in this method could be prepared from Aedes albopictus cell cultures (C6/36). The objective of this study was to maintain the four viral serotypes (D1 (RIO), D2 (RIO), D3 (H-87), D4 (BV)) on C6/36 cells for the preparation of viral antigen in the future. The C6/36 cells were cultured in L-15 medium supplemented with 10% FCS, infected with 50 µl of each viral serotype and then incubated for 5-7 days at 28°C. After confirmation of the infection by indirect immunofluorescence (IIF), viral titration was performed by lysis plaque assay. The serotypes titres obtained were as follows: [2.9 x 106 PFU/ml] for D1 (RIO), (4.4 x107 PFU/ml) for D2 (RIO), (6.4 x 10 7 PFU/ml) for D3 (H87) and (5.1 x106 PFU/ml) for D4 (BV). The production of viral antigens is very important because they could be used in several diagnosis methods.

Asunto(s)

Dengue , Salud Pública , Células Cultivadas

RESUMEN

A locally sustainable system of prenatal screening of Trypanosoma cruzi infection has been implemented in rural health care centers of endemic areas in Paraguay A total of 61.091 women from Paraguari and Cordillera Departments were serologically evaluated, where 7.802 (12,7%) resulted to be anti-T. cruzi IgG positive. A total of 1,865 infants born to seropositive mothers were examined by parasitological techniques, such as direct microscopic observation and polymerase chain reaction, and serologically by ELISA, ELISA-SAPA and IFI. 104 infected babies were detected and treated with benznidazole. The recovery of babies born to seropositive mothers performing a single examination at the age of 6 months was significantly higher, as compared with the recommended method involving two examinations, both at birth and after 6 months of age. Although at 6 months of age in 7% of the infants maternal IgG was still detected. PCR was the most sensitive technique for early detection of T. cruzi infection in babies, but we do not recommend it use for diagnosis in high endemic areas, considering that for the screening of 815 babies, 2000 reactions were needed. We propose a strategy to detect congenital transmission of Chagas disease, based on a large-scale study, where the shortcomings of the different serological and parasitological techniques are discussed.

Asunto(s)

Humanos , Animales , Femenino , Recién Nacido , Lactante , Niño , Adolescente , Adulto , Persona de Mediana Edad , Embarazo , Atención Primaria de Salud/organización & administración , Diagnóstico Prenatal/normas , Enfermedad de Chagas/congénito , Enfermedad de Chagas/diagnóstico , Enfermedades Endémicas , Tamizaje Neonatal/normas , Anticuerpos Antiprotozoarios/sangre , Enfermedad de Chagas/epidemiología , Ensayo de Inmunoadsorción Enzimática , Inmunoglobulina G/sangre , Biomarcadores/sangre , Paraguay/epidemiología , Población Rural , Estudios Seroepidemiológicos , Trypanosoma cruzi/inmunología

RESUMEN

Growth hormone (GH) has been shown to have a profound impact on fish physiology and metabolism. However, detailed studies in transgenic fish have not been conducted. We have characterized the food conversion efficiency, protein profile, and biochemical correlates of growth rate in transgenic tilapia expressing the tilapia GH cDNA under the control of human cytomegalovirus regulatory sequences. Transgenic tilapia exhibited about 3.6-fold less food consumption than nontransgenic controls (P < 0.001). The food conversion efficiency was significantly (P < 0.05) higher (290%) in transgenic tilapia (2.3 +/- 0.4) than in the control group (0.8 +/- 0.2). Efficiency of growth, synthesis retention, anabolic stimulation, and average protein synthesis were higher in transgenic than in nontransgenic tilapia. Distinctive metabolic differences were found in transgenic juvenile tilapia. We had found differences in hepatic glucose, and in agreement with previous results we observed differences in the level of enzymatic activities in target organs. We conclude that GH-transgenic juvenile tilapia show altered physiological and metabolic conditions and are biologically more efficient.

Asunto(s)

Hormona del Crecimiento/genética , Tilapia/fisiología , Animales , Animales Modificados Genéticamente , Citomegalovirus/genética , ADN Complementario , Ingestión de Energía , Metabolismo Energético , Femenino , Glucosa/metabolismo , Hormona del Crecimiento/fisiología , Humanos , Hígado/metabolismo , Masculino , Músculo Esquelético/metabolismo , Secuencias Reguladoras de Ácidos Nucleicos , Tilapia/genética , Tilapia/crecimiento & desarrollo

RESUMEN

Growth manipulation in fish is one of the targets of gene transfer experiments. The aim is to produce strains with improved growth performance. The transfer of growth hormone transgenes has been successful in many fish species. Now detailed knowledge of the molecular events that control growth in fish is necessary in order to efficiently manipulate this process. We have selected tilapia for our studies because these species are suitable for basic research as well as for the development of improved strains for aquaculture. Here we review the results of basic and applied research in the field of growth control and manipulation in tilapia. Our experiments produced new scientific results on growth control in tilapia. These results were used to develop a new aquacultured line with improved growth performance. Many of these results are probably applicable to other teleosts.

Asunto(s)

Explotaciones Pesqueras/métodos , Hormona del Crecimiento/fisiología , Tilapia/crecimiento & desarrollo , Animales , Animales Modificados Genéticamente , Biotecnología , Cuba , Metabolismo Energético , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Ingeniería Genética , Crecimiento/efectos de los fármacos , Hormona del Crecimiento/sangre , Hormona del Crecimiento/genética , Hormona del Crecimiento/farmacología , Factor I del Crecimiento Similar a la Insulina/biosíntesis , Factor I del Crecimiento Similar a la Insulina/genética , Masculino , Prolactina/sangre , Receptores de Somatotropina/efectos de los fármacos , Receptores de Somatotropina/fisiología , Seguridad , Transducción de Señal/efectos de los fármacos , Tilapia/genética , Tilapia/metabolismo , Transgenes

RESUMEN

Recent advances in modern marine biotechnology have permitted the generation of new strains of economically important fish species through the transfer of growth hormone genes. These transgenic fish strains show improved growth performance and therefore constitute a better alternative for aquaculture programs. Recently, we have obtained a transgenic tilapia line with accelerated growth. However, before introducing this line into Cuban aquaculture, environmental and food safety assessment was required by national authorities. Experiments were performed to evaluate the behavior of transgenic tilapia in comparison to wild tilapia as a way to assess the environmental impact of introducing transgenic tilapia into Cuban aquaculture. Studies were also conducted to evaluate, according to the principle of substantial equivalence, the safety of consuming transgenic tilapia as food. Behavior studies showed that transgenic tilapia had a lower feeding motivation and dominance status than controls. Food safety assessment indicated that tilapia growth hormone has no biological activity when administered to nonhuman primates. Furthermore, no effects were detected in human healthy volunteers after the consumption of transgenic tilapia. These results showed, at least under the conditions found in Cuba, no environmental implications for the introduction of this transgenic tilapia line and the safety in the consumption of tiGH-transgenic tilapia as an alternative feeding source for humans. These results support the culture and consumption of these transgenic tilapia.

RESUMEN

Growth is a complex process in fish. This study was designed to test the effect of different levels of recombinant tilapia growth hormone (tiGH) injected intraperitoneally in juvenile hybrid tilapia Oreochromis hornorum. Tilapia GH cDNA was cloned from hybrid O. hornorum tilapia. The mature protein was expressed in E. coli under regulation of the phage T7 promoter. The E. coli-derived tiGH was partially purified to 67% purity and, following renaturation, was shown to be biologically active in in vivo and in vitro assays. Recombinant tiGH stimulated extracellular matrix synthesis as shown by 35S-sulfate uptake in ceratobranchial cartilage explants. Zero, 0.1, 0.5 and 2.5 µg tiGH/g body weight (gbw) were injected in tilapia, and the effects on the growth-promoting action, hepatosomatic index (HSI), and mRNA insulin-like growth factor (IGF) induction were measured. A significant increase in the body weight (P < 0.05) and length (P < 0.01) was observed in tilapia receiving 0.5 µg tiGH/gbw. However, tilapia receiving 0.1 and 2.5 µg tiGH/gbw did not show an increase in body weight and length with respect to the control group receiving BSA injections. Binding sites for the recombinant tiGH were identified in the liver. Consistent with its somatotropic actions, the IGF mRNA induction was observed in the groups injected with 0.1 and 0.5 µg tiGH/gbw (P < 0.05). No significant increase in the HSI was detected in the injected groups when compared to the control group. These results demonstrated that the injection of biologically active E. coli-derived tiGH produces physiological changes in juvenile tilapia that ultimately resulted in a growth-promoting action only at a dose of 0.5 µg tiGH/gbw.

RESUMEN

In 1991 and 1992, a prenatal screening of Trypanosoma cruzi infection was carried out using ELISA and indirect immunofluorescence techniques. A total of 840 blood samples from pregnant women, obtained at the Maternity Ward of the Hospital de Clínicas, National University of Asunción (Asunción, Paraguay), and 1,022 samples from the Regional Hospital of the San Pedro Department of Paraguay were examined. It was observed that 7.7% and 10.5%, respectively, of the pregnant women were serologically positive for infection with T. cruzi. When blood samples obtained from newborns on the day of birth or, at the most, on the first few days afterwards were examined by direct microscopic observation, an incidence of congenital transmission of 3% was found. These results are consistent with those of neighboring countries. When a serologic follow-up was conducted on the newborns until six months of age, the incidence of congenital transmission reached 10%. The same incidence rate was obtained when the samples collected during the first days after birth were examined by the polymerase chain reaction (PCR). Fifty-eight infants born to seropositive mothers were followed-up, two of which were positive by direct microscopic observation at birth, and four who were PCR-positive, but microscopy-negative at birth. None of the infants were positive for IgM at birth. The infected babies were treated with benznidazole and were followed-up by serology and PCR for four years. We conclude that the PCR has a clear advantage over conventional techniques for the early detection of congenital transmission of T. cruzi infection, and for monitoring infants undergoing chemotherapy.

Asunto(s)

Enfermedad de Chagas/congénito , Enfermedad de Chagas/tratamiento farmacológico , ADN Protozoario/sangre , Reacción en Cadena de la Polimerasa , Complicaciones Parasitarias del Embarazo , Trypanosoma cruzi/genética , Animales , Anticuerpos Antiprotozoarios/sangre , Enfermedad de Chagas/diagnóstico , Enfermedad de Chagas/epidemiología , Enfermedad de Chagas/transmisión , Ensayo de Inmunoadsorción Enzimática , Femenino , Técnica del Anticuerpo Fluorescente Indirecta , Estudios de Seguimiento , Humanos , Inmunoglobulina M/sangre , Incidencia , Recién Nacido , Transmisión Vertical de Enfermedad Infecciosa , Nitroimidazoles/uso terapéutico , Paraguay/epidemiología , Embarazo , Complicaciones Parasitarias del Embarazo/epidemiología , Tripanocidas/uso terapéutico , Trypanosoma cruzi/inmunología

RESUMEN

The transfer of growth hormone (GH) genes has opened new possibilities for the manipulation of growth in economically important fish species. However, the ectopic GH levels to optimize growth acceleration in fish, and specially in tilapia, are not known and must be determined experimentally. The tilapia GH (tiGH) cDNA was used to construct chimeric genes expressing different levels of tiGH in vitro and in vivo. These constructs were used to generate four lines of transgenic tilapia by microinjection into one-cell embryos. Different patterns and levels of ectopic expression of tiGH and IGF were detected in organs of transgenic tilapia by RNA or protein analysis. The two lines with lower ectopic tiGH mRNA levels were the only ones showing growth acceleration, suggesting that the expression of ectopic tiGH promoted growth only at low expression levels. The effect of higher ectopic tiGH levels resembled the physiologic situation of low condition factor and permitted us to postulate a model for growth acceleration in transgenic tilapia expressing ectopic tiGH.

Asunto(s)

Animales Modificados Genéticamente , Hormona del Crecimiento/biosíntesis , Hormona del Crecimiento/genética , Tilapia/genética , Animales , Cartilla de ADN , Embrión no Mamífero/fisiología , Técnicas de Transferencia de Gen , Genes Reporteros , Microinyecciones , Reacción en Cadena de la Polimerasa , ARN Mensajero/biosíntesis , Proteínas Recombinantes de Fusión/biosíntesis , Transcripción Genética

RESUMEN

The generation of transgenic fish with the transfer of growth hormone (GH) genes has opened new possibilities for the manipulation of growth in economically important fish species. The tilapia growth hormone (tiGH) cDNA was linked to the human cytomegalovirus (CMV) enhancer-promoter and used to generate transgenic tilapia by microinjection into one-cell embryos. Five transgenic tilapia were obtained from 40 injected embryos. A transgenic animal containing one copy of the transgene per cell was selected to establish a transgenic line. The transgene was stably transmitted to F1 and F2 generations in a Mendelian fashion. Ectopic, low-level expression of tiGH was detected in gonad and muscle cells of F1 transgenic tilapia by immunohystochemical analysis of tissue sections. Nine-month-old transgenic F1 progeny were 82% larger than nontransgenic fish at p = .001. These results showed that low-level ectopic expression of tiGH resulted in a growth acceleration in transgenic tilapia. Tilapia GH gene transfer is an alternative for growth acceleration in tilapia.

Asunto(s)

Hormona del Crecimiento/genética , Tilapia/crecimiento & desarrollo , Tilapia/genética , Animales , Animales Modificados Genéticamente , Constitución Corporal , Peso Corporal , Citomegalovirus/genética , Elementos de Facilitación Genéticos/genética , Femenino , Expresión Génica , Genes/genética , Gónadas/química , Hormona del Crecimiento/análisis , Humanos , Masculino , Músculos/química , Especificidad de Órganos , Regiones Promotoras Genéticas/genética

RESUMEN

Trans-sialidase, an enzyme that transfers sialic acid among macromolecules, has been implicated in invasion of host cells by Trypanosoma cruzi, the agent of Chagas' disease. Most antibodies produced in natural and experimental infections are directed to the highly antigenic C-terminal domain (shed acute-phase antigen). These antibodies do not inhibit the trans-sialidase activity, which is present in the N-terminal domain of the molecule. Antibodies able to inhibit trans-sialidase in sera from human infections have been found. TIA (trans-sialidase inhibition assay) was positive in sera from patients with acute and chronic infections. Healthy and congenitally infected infants born to mothers with Chagas' disease were also TIA-positive, but the antibody titers diminished within months after birth or after treatment. Thus, antibodies neutralizing trans-sialidase are detectable in most forms of T. cruzi human infections, and TIA may be useful in the diagnosis of Chagas' disease.

Asunto(s)

Anticuerpos Antiprotozoarios/inmunología , Antígenos de Protozoos/inmunología , Enfermedad de Chagas/inmunología , Glicoproteínas/antagonistas & inhibidores , Glicoproteínas/inmunología , Neuraminidasa/antagonistas & inhibidores , Neuraminidasa/inmunología , Trypanosoma cruzi/enzimología , Enfermedad Aguda , Animales , Enfermedad de Chagas/congénito , Enfermedad de Chagas/tratamiento farmacológico , Enfermedad Crónica , Femenino , Humanos , Sueros Inmunes , Recién Nacido , Pruebas de Neutralización , Nitroimidazoles/uso terapéutico , Tripanocidas/uso terapéutico , Trypanosoma cruzi/inmunología

RESUMEN

The prevalence of Chagas' disease in Ayoreo amerindians living in their traditional habitat of the Paraguayan Chaco was assessed by ELISA and indirect immunofluorescence techniques. The Ayoreo is the last hunther-gatherer tribe of the Paraguayan Chaco and was "pacified" between 1965 and 1975. They still maintain a seminomadic way of life. Chagas' disease prevalence in the Ayoreo communities probably represents their natural prevalence in Chaco Amerindians before settlement. Triatoma sordida was identified as the insect vector in the settlements of Gesudi and Chovoreca, while the highly domiciliary Triatoma infestans was found in Campo Loro. The prevalence of Chagas' disease in Gesudi and Chovoreca, based on our serological surveys was 12-13%. Other authors reported a 72.9% of Chagas' disease prevalence in amerindians settled in the Chaco since 1930-1940.

Asunto(s)

Enfermedad de Chagas/epidemiología , Indígenas Sudamericanos , Adolescente , Adulto , Anciano , Animales , Anticuerpos Antiprotozoarios/sangre , Niño , Preescolar , Ensayo de Inmunoadsorción Enzimática , Femenino , Técnica del Anticuerpo Fluorescente , Vivienda , Humanos , Lactante , Insectos Vectores/parasitología , Masculino , Persona de Mediana Edad , Paraguay/epidemiología , Prevalencia , Triatoma/parasitología , Trypanosoma cruzi/inmunología , Trypanosoma cruzi/aislamiento & purificación

RESUMEN

A simple and inexpensive assay for detection of H2S producing bacteria in drinking water was evaluated in Paraguay. Using an improved preparation procedure, results were basically temperature independent in the range of 22-37 degrees C and correlated well with the presence of total coliform bacteria (96%, 28 degrees C). The assay was not suitable for control of surface water and dug well water due to the frequent presence of non-faecal coliforms. However, it was very suitable for routine control of high quality water systems, like treated community water systems or deep-tube well water, where complete absence of coliforms is required. The H2S-test is very inexpensive and does not require a laboratory technician or special equipment. Its use permits a cost-effective routine control of high quality community water systems in developing countries. In addition, this test turned out to be an effective educational tool for heightening the awareness of people towards dangers of unclean drinking water.

Asunto(s)

Enterobacteriaceae/crecimiento & desarrollo , Sulfuro de Hidrógeno/análisis , Microbiología del Agua , Abastecimiento de Agua/normas , Técnicas Bacteriológicas , Recuento de Colonia Microbiana , Estudios de Evaluación como Asunto , Heces/microbiología , Paraguay , Sensibilidad y Especificidad , Temperatura

RESUMEN

Una alta expresión de tPA humana recombinante en células de hamster chino (CHO), fue obtenida usando el sistema de coamplificación del gen de la dehidrofolato reductasa (DHFR). La proteina fue secretada activa al medio de cultivo. En varios clones se mantuvo la producción estable, aun en ausencia de presión selectiva. No obstante, cuando el mismo ADN complementario fue clonado en un vector de expresión de baculovirus, sólo fue posible detectar niveles muy bajos de actividad tPA (AU)

Asunto(s)

Cricetinae , Animales , Cricetulus , Amplificación de Genes , ADN , Plasminógeno , ADN , Células Clonales , Tetrahidrofolato Deshidrogenasa , Ovario , Cuba

RESUMEN

(AU)

Asunto(s)

Animales , Biotecnología , Peces/embriología , Cuba

Asunto(s)

Animales , Biotecnología , Peces/embriología , Cuba

RESUMEN

Una alta expresión de tPA humana recombinante en células de hamster chino (CHO), fue obtenida usando el sistema de coamplificación del gen de la dehidrofolato reductasa (DHFR). La proteina fue secretada activa al medio de cultivo. En varios clones se mantuvo la producción estable, aun en ausencia de presión selectiva. No obstante, cuando el mismo ADN complementario fue clonado en un vector de expresión de baculovirus, sólo fue posible detectar niveles muy bajos de actividad tPA

Asunto(s)

Cricetinae , Animales , Células Clonales , Cricetulus , ADN , Amplificación de Genes , Ovario , Plasminógeno , Tetrahidrofolato Deshidrogenasa , Cuba