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1.
Proc Biol Sci ; 291(2015): 20232172, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38290541

RESUMEN

The evolution of flight is a rare event in vertebrate history, and one that demands functional integration across multiple anatomical/physiological systems. The neuroanatomical basis for such integration and the role that brain evolution assumes in behavioural transformations remain poorly understood. We make progress by (i) generating a positron emission tomography (PET)-based map of brain activity for pigeons during rest and flight, (ii) using these maps in a functional analysis of the brain during flight, and (iii) interpreting these data within a macroevolutionary context shaped by non-avian dinosaurs. Although neural activity is generally conserved from rest to flight, we found significant increases in the cerebellum as a whole and optic flow pathways. Conserved activity suggests processing of self-movement and image stabilization are critical when a bird takes to the air, while increased visual and cerebellar activity reflects the importance of integrating multimodal sensory information for flight-related movements. A derived cerebellar capability likely arose at the base of maniraptoran dinosaurs, where volumetric expansion and possible folding directly preceded paravian flight. These data represent an important step toward establishing how the brain of modern birds supports their unique behavioural repertoire and provide novel insights into the neurobiology of the bird-like dinosaurs that first achieved powered flight.


Asunto(s)
Columbidae , Dinosaurios , Animales , Evolución Biológica , Fósiles , Encéfalo/fisiología , Dinosaurios/anatomía & histología , Filogenia , Vuelo Animal
2.
Acta Parasitol ; 69(1): 616-627, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38294711

RESUMEN

PURPOSE: Trypanosoma cruzi and Leishmania spp. coexist in several endemic areas, and there are few studies of Chagas disease and leishmaniasis coinfection worldwide; for this reason, the objective of this work was to determine the Chagas disease and leishmaniasis coinfection in several rural communities co-endemic for these diseases. METHODS: A total of 1107 human samples from six co-endemic rural communities of Cojedes state, Venezuela, were analyzed. Serum samples were evaluated by ELISA, indirect hemagglutination, and indirect immunofluorescence for Chagas disease diagnosis, and individuals were evaluated for leishmaniasis by leishmanin skin test (LST). Approximately, 30% of the individuals were also analyzed by PCR (blood clot samples) for T. cruzi and for Leishmania spp. RESULTS: The 14.7% of the individuals were positive to Trypanosoma cruzi infection by serology, and 25.8% were positive to Leishmania spp. current or past infection by LST. Among the group with PCR results, 7.8% were positive for T. cruzi, and 9.4% for Leishmania spp. The coinfection T. cruzi/Leishmania spp. was 6.5%. The T. cruzi DTUs of the positive blood clot samples were TcI, revealed using the molecular markers: (i) intergenic region of the miniexon, (ii) D7 divergent domain of the 24Sα rDNA, (iii) size-variable domain of the 18S rDNA, and (iv) hsp60-PCR-RFLP (EcoRV). The Leishmania species identified were L. (Leishmania) mexicana and L. (Viannia) braziliensis. CONCLUSION: A high prevalence was found for T. cruzi and Leishmania spp. single and coinfections in almost all communities studied, being these results of relevance for the implementation of control programs in co-endemic areas.


Asunto(s)
Enfermedad de Chagas , Coinfección , Leishmania , Leishmaniasis , Población Rural , Trypanosoma cruzi , Humanos , Venezuela/epidemiología , Enfermedad de Chagas/epidemiología , Enfermedad de Chagas/parasitología , Coinfección/parasitología , Coinfección/epidemiología , Leishmaniasis/epidemiología , Leishmaniasis/parasitología , Trypanosoma cruzi/genética , Trypanosoma cruzi/aislamiento & purificación , Adulto , Adolescente , Masculino , Niño , Femenino , Persona de Mediana Edad , Adulto Joven , Animales , Leishmania/genética , Leishmania/aislamiento & purificación , Leishmania/clasificación , Preescolar , Zoonosis/parasitología , Zoonosis/epidemiología , Anciano , Reacción en Cadena de la Polimerasa , Anticuerpos Antiprotozoarios/sangre , Lactante , Ensayo de Inmunoadsorción Enzimática
3.
Parasitol Res ; 123(1): 17, 2023 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-38060033

RESUMEN

It is estimated that 6-7 million people worldwide are infected with Trypanosoma cruzi, the parasite that causes Chagas disease. In Venezuela, Chagas disease remains a public health problem. In this work, T. cruzi isolates from six species of triatomines and mammals of the orders Didelphimorphia and Xenarthra, captured in rural communities of Monagas, underwent parasitological and molecular characterization. A total of 471 triatomines and 17 mammals were captured, with a natural infection rate of 41.4% and 70.6%, respectively. In the male NMRI mouse model used for parasitological characterization (prepatent period, parasitemia curve, mouse mortality, and tissular parasitism), T. cruzi isolates exhibited high lethality due to their pronounced virulence, irrespective of the parasite load in each mouse, resulting in a mortality rate of 75%. Among the vector isolates, in the mouse model, only 2 out of 6 remained alive, while the rest perished during the evaluation. Conversely, the isolates from mammals proved fatal for all the inoculated mice. All isolates were identified as belonging to DTU TcI, based on the molecular markers such as the intergenic region of the miniexon, D7 divergent domain of the 24Sα rDNA, size-variable domain of the 18S rDNA, and hsp60-PCR-RFLP-EcoRV. This study demonstrates the presence of vectors and mammalian reservoirs naturally infected with T. cruzi in communities of Monagas, the 9th largest and 9th most populous state in Venezuela. This situation represents a neglected epidemiological problem demanding urgent attention and imperative health care intervention.


Asunto(s)
Enfermedad de Chagas , Marsupiales , Trypanosoma cruzi , Animales , Masculino , Humanos , Ratones , Venezuela/epidemiología , Enfermedad de Chagas/epidemiología , Enfermedad de Chagas/parasitología , Mamíferos/parasitología , ADN Ribosómico
4.
Nat Microbiol ; 8(2): 299-308, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36690860

RESUMEN

Persistence of the human immunodeficiency virus type-1 (HIV-1) latent reservoir in infected individuals remains a problem despite fully suppressive antiretroviral therapy (ART). While reservoir formation begins during acute infection, the mechanisms responsible for its establishment remain unclear. CD8+ T cells are important during the initial control of viral replication. Here we examined the effect of CD8+ T cells on formation of the latent reservoir in simian immunodeficiency virus (SIV)-infected macaques by performing experimental CD8+ depletion either before infection or before early (that is, day 14 post-infection) ART initiation. We found that CD8+ depletion resulted in slower decline of viremia, indicating that CD8+ lymphocytes reduce the average lifespan of productively infected cells during acute infection and early ART, presumably through SIV-specific cytotoxic T lymphocyte (CTL) activity. However, CD8+ depletion did not change the frequency of infected CD4+ T cells in the blood or lymph node as measured by the total cell-associated viral DNA or intact provirus DNA assay. In addition, the size of the persistent reservoir remained the same when measuring the kinetics of virus rebound after ART interruption. These data indicate that during early SIV infection, the viral reservoir that persists under ART is established largely independent of CTL control.


Asunto(s)
Infecciones por VIH , Síndrome de Inmunodeficiencia Adquirida del Simio , Virus de la Inmunodeficiencia de los Simios , Animales , Humanos , Virus de la Inmunodeficiencia de los Simios/genética , Síndrome de Inmunodeficiencia Adquirida del Simio/tratamiento farmacológico , Linfocitos T CD8-positivos , Antirretrovirales/uso terapéutico , Macaca mulatta , Infecciones por VIH/tratamiento farmacológico
5.
Ann Clin Transl Neurol ; 9(9): 1345-1358, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35880319

RESUMEN

OBJECTIVE: Intracellular signaling networks rely on proper membrane organization to control an array of cellular processes such as metabolism, proliferation, apoptosis, and macroautophagy in eukaryotic cells and organisms. Phosphatidylinositol 4-phosphate (PI4P) emerged as an essential regulatory lipid within organelle membranes that defines their lipid composition and signaling properties. PI4P is generated by four distinct phosphatidylinositol 4-kinases (PI4K) in mammalian cells: PI4KA, PI4KB, PI4K2A, PI4K2B. Animal models and human genetic studies suggest vital roles of PI4K enzymes in development and function of various organs, including the nervous system. Bi-allelic variants in PI4KA were recently associated with neurodevelopmental disorders (NDD), brain malformations, leukodystrophy, primary immunodeficiency, and inflammatory bowel disease. Here, we describe patients from two unrelated consanguineous families with PI4K2A deficiency and functionally explored the pathogenic mechanism. METHODS: Two patients with PI4K2A deficiency were identified by exome sequencing, presenting with developmental and epileptic-dyskinetic encephalopathy. Neuroimaging showed corpus callosum dysgenesis, diffuse white matter volume loss, and hypoplastic vermis. In addition to NDD, we observed recurrent infections and death at toddler age. We further explored identified variants with cellular assays. RESULTS: This clinical presentation overlaps with what was previously reported in two affected siblings with homozygous nonsense PI4K2A variant. Cellular studies analyzing these human variants confirmed their deleterious effect on PI4K2A activity and, together with the central role of PI4K2A in Rab7-associated vesicular trafficking, establish a link between late endosome-lysosome defects and NDD. INTERPRETATION: Our study establishes the genotype-phenotype spectrum of PI4K-associated NDD and highlights several commonalities with other innate errors of intracellular trafficking.


Asunto(s)
Epilepsia Generalizada , Antígenos de Histocompatibilidad Menor , Malformaciones del Sistema Nervioso , Trastornos del Neurodesarrollo , Fosfotransferasas (Aceptor de Grupo Alcohol) , Epilepsia Generalizada/genética , Homocigoto , Humanos , Antígenos de Histocompatibilidad Menor/genética , Malformaciones del Sistema Nervioso/genética , Trastornos del Neurodesarrollo/genética , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética
6.
Acta Parasitol ; 67(3): 1440-1446, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35679006

RESUMEN

INTRODUCTION: Toxoplasmosis is caused by the parasite Toxoplasma gondii. The infection is generally asymptomatic and the most severe cases occur in immunosuppressed patients. The main route of transmission is the ingestion of water or food contaminated with cysts of the parasite. The objective of this work was the standardization of the PCR for the detection of the T. gondii B1 gene in meat and water samples and cloning of the product for use as a control. METHODS: The optimal reaction conditions of the different components of the PCR were determined and the technique was used to detect DNA from meat and water samples. Bands were purified and cloned into a pGEM-T-Easy vector and used as a control in the PCR. RESULTS: Optimal PCR conditions were; 100 µM dNTP, 0.4 µM primers, and 0.5 U Taq polymerase. The product obtained from the PCR was cloned with a simple cloning strategy with efficient results. With the standardized PCR and using the cloned DNA as a control, T. gondii DNA was detected in 90% of the positives samples of meat and water and there was no amplification in the negative samples. CONCLUSIONS: The PCR assay standardized in this study was demonstrated to be an effective technique to detect T. gondii DNA in meat and water samples. The cloning of PCR product and its application as a control in molecular diagnosis of toxoplasmosis might improve the reproducibility of this method and avoid the use of patient samples or cultures, which present several limitations.


Asunto(s)
Toxoplasma , Toxoplasmosis , Clonación Molecular , ADN Protozoario/genética , Humanos , Carne , Reacción en Cadena de la Polimerasa , Estándares de Referencia , Reproducibilidad de los Resultados , Toxoplasma/genética , Toxoplasmosis/diagnóstico , Agua
7.
PLoS Negl Trop Dis ; 16(1): e0010109, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35030166

RESUMEN

BACKGROUND: Neurocysticercosis (NCC), and cystic echinococcosis (CE) are two neglected diseases caused by cestodes, co-endemic in many areas of the world. Imaging studies and serological tests are used in the diagnosis of both parasitic diseases, but cross-reactions may confound the results of the latter. The novel multiplex bead-based assay with recombinant antigens has been reported to increases the diagnostic accuracy of serological techniques. METHODOLOGY: We set-up an immunoassay based on the multiplex bead-based platform (MBA), using the rT24H (against Cysticercus cellulosae, causing cysticercosis) and r2B2t (against Echinococcus granulosus sensu lato, causing CE) recombinant antigens, for simultaneous and differential diagnosis of these infections. The antigens were tested on 356 sera from 151 patients with CE, 126 patients with NCC, and 79 individuals negative for both diseases. Specificity was calculated including sera from healthy donors, other neurological diseases and the respective NCC or CE sera counterpart. The diagnostic accuracy of this assay was compared with two commercial ELISA tests, Novalisa and Ridascreen, widely used in the routine diagnosis of cysticercosis and CE, respectively. MAIN FINDINGS: For the diagnosis of NCC, sensitivity ranged from 57.94-63.49% for the rT24H-MBA, and 40.48-46.03% for Novalisa ELISA depending on exclusion or inclusion of sera having equivocal results on ELISA from the analysis; specificities ranged from 90.87-91.30% and 70.43-76.96%, respectively. AUC values of the ROC curve were 0.783 (rT24H) and 0.619 (Novalisa) (p-value < 0.001). For the diagnosis of CE, the sensitivity of the r2B2t-MBA ranged from 68.87-69.77% and of Ridascreen ELISA from 50.00-57.62%; specificities from 92.47-92.68% and from 74.15-80.98%, respectively. AUC values were 0.717 and 0.760, respectively. CONCLUSIONS/SIGNIFICANCE: Overall, the recombinant antigens tested with the bead-based technology showed better diagnostic accuracy than the commercial assays, particularly for the diagnosis of NCC. The possibility of testing the same serum sample simultaneously for the presence of antibodies against both antigens is an added value particularly in seroprevalence studies for cysticercosis linked to control programs in endemic areas where these two parasites coexist.


Asunto(s)
Anticuerpos Antihelmínticos/sangre , Equinococosis/diagnóstico , Echinococcus granulosus/inmunología , Neurocisticercosis/diagnóstico , Taenia solium/inmunología , Animales , Antígenos Helmínticos/genética , Antígenos Helmínticos/inmunología , Equinococosis/parasitología , Ensayo de Inmunoadsorción Enzimática/métodos , Humanos , Enfermedades Desatendidas/diagnóstico , Enfermedades Desatendidas/parasitología , Neurocisticercosis/parasitología , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Sensibilidad y Especificidad , Pruebas Serológicas
8.
Acta Parasitol ; 67(2): 1015-1023, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35013940

RESUMEN

INTRODUCTION: Trypanosoma cruzi, Trypanosoma rangeli and Leishmania spp. are parasites that coexist in several endemic areas. The identification of these parasites in hosts is important for the control programs. METHODS: 216 samples from human blood (101), blood of other mammals (45) and triatomine intestinal content and hemolymph (70), from an endemic area of Venezuela, were analysed. The samples were evaluated by; serology (only humans) and PCR for T. cruzi in human, other mammals and triatomines, PCR for T. rangeli in mammals-including human and triatomines and PCR for Leishmania in mammals-including human. RESULTS: The 9.9% of the human samples were positive for T. cruzi by serology, 11.9% by PCR, 4% for T. rangeli PCR and none for Leishmania spp. PCR. 60% of the samples of other mammals showed DNA amplification for T. cruzi, 42.2% for T. rangeli and 4.4% for Leishmania spp. 61.4% of the triatomine samples showed DNA amplification for T. cruzi and 10% for T. rangeli. CONCLUSIONS: High T. cruzi infection was detected in mammals and triatomines compared with T. rangeli. Low leishmanial infection was detected in other mammals. It is the first time that T. cruzi/T. rangeli coinfection, in humans, Canis familiaris (dog), and Bos Taurus (cow), were reported world-wide, and that this coinfection was described in Tamandua tetradactyla (anteater) from Venezuela. The coinfection T. cruzi/T. rangeli in mammals-including humans and triatomines, and coinfection T. cruzi/Leishmania spp. in non-human mammals, show the risk for trypanosomic zoonoses in this endemic area.


Asunto(s)
Enfermedad de Chagas , Coinfección , Leishmania , Parásitos , Trypanosoma cruzi , Animales , Bovinos , Enfermedad de Chagas/epidemiología , Enfermedad de Chagas/veterinaria , Coinfección/epidemiología , Coinfección/parasitología , Coinfección/veterinaria , ADN , Perros , Femenino , Humanos , Leishmania/genética , Mamíferos/parasitología , Parásitos/genética , Población Rural , Trypanosoma cruzi/genética , Venezuela/epidemiología
9.
Artículo en Inglés | MEDLINE | ID: mdl-34887225

RESUMEN

INTRODUCTION: The sensitivity and specificity of diagnostic techniques for Chagas disease depend largely on the antigens and targets used and on the immune response and characteristics of the infection of the population where it is applied, hence the need for evaluation of the diagnostic techniques available in a given area. So, the objective of this work was to evaluate two commercial kits for the immunological and molecular diagnosis of Chagas disease in endemic areas of Venezuela. METHODS: The evaluated kits were: Chagas ELISA IgG+IgM® and Speed Oligo Chagas® (Vircell®, Granada, Spain). They were evaluated with 129 samples (35 from patients in the acute phase, 33 in the chronic phase, 31 from patients with other diseases, and 30 from healthy individuals). The results were compared with those obtained in the conventional ELISA and PCR-satellite DNA tests for Trypanosoma cruzi. RESULTS: With Chagas ELISA IgG+IgM® a sensitivity of 94.1% and specificity of 93.4% were obtained, with Speed Oligo Chagas® a sensitivity of 92.6% and specificity of 100% were achieved, values similar to those showed by conventional ELISA and satDNA-PCR. CONCLUSION: The sensitivity and specificity of the commercial kits evaluated make them suitable for the diagnosis of Chagas disease in endemic areas of Venezuela.


Asunto(s)
Enfermedad de Chagas , Trypanosoma cruzi , Enfermedad de Chagas/diagnóstico , Enfermedad de Chagas/epidemiología , Ensayo de Inmunoadsorción Enzimática/métodos , Humanos , Sensibilidad y Especificidad , Venezuela/epidemiología
10.
Rev. peru. med. exp. salud publica ; 38(4): 621-626, oct.-dic. 2021. tab, graf
Artículo en Español | LILACS | ID: biblio-1365932

RESUMEN

RESUMEN El objetivo de este estudio fue determinar manifestaciones oculares de la toxocariasis en escolares. Se realizó un estudio en dos escuelas del estado Anzoátegui en Venezuela en el 2019. Se empleó la prueba de ELISA para determinar los anticuerpos IgG contra Toxocara spp. Las familias completaron un cuestionario y los niños fueron evaluados clínicamente por pediatras y oftalmólogos. Participaron 118 niños, el 18,6% presentó anticuerpos anti-Toxocara spp. Las manifestaciones clínicas con asociación estadísticamente significativa fueron las reacciones alérgicas, epífora y disminución de la agudeza visual. En la evaluación oftalmológica se encontró queratitis, uveítis, iritis, granuloma retiniano, endoftalmitis, amaurosis, leucocoria, desprendimiento de retina y endotropía. Los hallazgos muestran una alta frecuencia de enfermedad ocular en niños con toxocariasis de un estado de Venezuela.


ABSTRACT The objective of this study was to determine ocular manifestations of toxocariasis in schoolchildren. A study was conducted in two schools in the Anzoátegui state in Venezuela in 2019. The ELISA test was used to determine IgG antibodies against Toxocara spp. The families completed a questionnaire, and the children were clinically evaluated by pediatricians and ophthalmologists. 118 children participated, 18.6% presented anti-Toxocara spp. The clinical manifestations with a statistically significant association were allergic reactions, epiphora, and decreased visual acuity. The ophthalmological evaluation found keratitis, uveitis, iritis, retinal granuloma, endophthalmitis, amaurosis, leukocoria, retinal detachment and endotropia. The findings show a high frequency of eye disease in children with toxocariasis from a state of Venezuela.


Asunto(s)
Toxocara , Toxocariasis , Manifestaciones Oculares , Parásitos , Instituciones Académicas , Agudeza Visual , Estudios Seroepidemiológicos , Diagnóstico , Zoonosis Virales
11.
J Vector Borne Dis ; 58(1): 18-27, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34818859

RESUMEN

BACKGROUND & OBJECTIVES: Trypanosoma cruzi, the causative agent of American trypanosomiasis, has been reported in 180 mammalian species and 154 triatomines species of Neotropic. This is a clonal parasite with variable biological behaviour, associated with the genetics of the parasite and its hosts. To know the eco-pathogenic complex of this zoonosis, it was proposed to characterize T. cruzi isolates obtained from triatomines and domestic, peridomestic and wild mammals of the eastern and central-western regions of Venezuela. METHODS: The positivity to T. cruzi was established and the isolates were genetically characterized by PCR amplification of the mini-exon gene, the DNA coding for 24Sa and 18S rRNA, and polymorphic sequences-RFLPs. The sampling sites were georeferenced using the MapSource Software and ArcGis 9.3 programs to generate distribution maps of the isolates. RESULTS: Of the 460 hosts (205 triatomines and 255 mammals), 49% were positive for the parasite. On the other hand, 38 isolates obtained from the triatomines and 23 isolates obtained from mammals were evaluated. The TcI genotype predominated in most of the isolates; however, in those obtained from triatomines the presence of the TcIII genotype in single infections and TcI + TcIII or TcI + TcIV in mixed infections was also evidenced. INTERPRETATION & CONCLUSION: There is a possibility that the triatomines act as biological syringes for these genotypes associated exclusively to them. The heterogeneity in T. cruzi isolates demonstrated the complexity of parasitosis in these regions, presenting its control and prevention as a challenge.


Asunto(s)
Enfermedad de Chagas , Trypanosoma cruzi , Animales , Enfermedad de Chagas/diagnóstico , Enfermedad de Chagas/epidemiología , Genotipo , Mamíferos , Trypanosoma cruzi/genética , Venezuela/epidemiología
12.
J Immunother Cancer ; 9(11)2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34789550

RESUMEN

BACKGROUND: Tumor-specific cytotoxic T cells and T cell receptors are effective tools for cancer immunotherapy. Most efforts to identify them rely on known antigens or lymphocytes that have infiltrated into the tumor bed. Approaches to empirically identify tumor-targeting T cells and T cell receptors by exploiting all antigens expressed on tumor cell surfaces are not well developed for most carcinomas, including pancreatic cancer. METHODS: Autologous tumor organoids were stimulated with T cells from the patients' peripheral blood for 2 weeks to generate the organoid-primed T (opT) cells. opT cell phenotype was analyzed by monitoring changes in the expression levels of 28 cell surface and checkpoint proteins. Expression of ligands of the immune checkpoints was investigated by immunohistochemistry staining. T cells were labeled with carboxyfluorescein succinimidyl ester (CFSE) and assayed by flow cytometry to monitor tumor-induced T cell proliferation changes. opT cell-mediated killing of three-dimensional organoids was measured using an M30 ELISA kit. T cell receptors (TCRs) were identified by deep sequencing of gDNA isolated from T cells, and the TCR specificity was confirmed by transferring TCRs to the T cell line SKW-3 or donor T cells. RESULTS: The co-culture was effective in the generation of CD8 + or CD4+opT cells. The opT cells killed autologous tumors in a granzyme B or Fas-Fas ligand-dependent manner and expressed markers of tissue-resident memory phenotype. Each patient-derived opT cell culture displayed a unique complement of checkpoint proteins. Interestingly, only NKG2A blockade showed a potent increase in the interferon-γ production compared with blocking programmed cell death protein 1 (PD-1) or programmed cell death ligand 1 (PD-L1) or TIM3 or TIGIT or LAG3. Importantly, TCR sequencing demonstrated a dramatic clonal expansion of T cells with a restricted subset of TCRs. Cloning and transferring the TCRs to heterologous T cells was sufficient to confer tumor cell recognition and cytotoxic properties in a patient-specific manner. CONCLUSION: We report a platform for expanding tumor-targeting T cells from the peripheral blood of patients with pancreatic cancer. We identify the NKG2A-HLA-E axis as a potentially important checkpoint for CD8 +T cells for pancreatic cancer. Lastly, we demonstrate empirical identification of tumor-targeting TCRs that can be used for TCR-therapeutics.


Asunto(s)
Organoides/inmunología , Neoplasias Pancreáticas/inmunología , Receptores de Antígenos de Linfocitos T/metabolismo , Animales , Humanos , Ratones
13.
Vet Parasitol Reg Stud Reports ; 23: 100516, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33678371

RESUMEN

Hydrochoerus hydrochaeris (capybara), is a widely distributed rodent in Latin America, with exploitation for food purposes and also used in leather industry products. The infection of this rodent by trypanosomatids may not be detected by parasitological methods, due to low parasitemias. The Capybaras blood samples from the Apure State were collected on filter paper, DNA was extracted and PCR was performed. The PCR technique was used for the detection of Trypanosoma cruzi satellite and kinetoplast DNA, T. rangeli miniexon, T. evansi RIME sequence, and DNA encoding ribosomal RNA and internal transcribed spacer 1 from Leishmania spp. Of the 16 evaluated samples, 12 (75%) were positive for T. cruzi, two for T. rangeli (12.5%), one for Leishmania spp. (6.3%) and none for T. evansi. Regarding coinfection, the two specimens infected with T. rangeli were also infected with T. cruzi (12.5%) and the positive sample for Leishmania spp. was also infected with T. cruzi (6.3%). The results shown in this study represent the first finding of T. cruzi infection, detected by molecular methods, world-wide and the first time that T. rangeli and Leishmania spp. have been found in capybaras. In addition, we report coinfections by T. cruzi/T. rangeli and T. cruzi/Leishmania spp. in H. hydrochaeris for the first time world-wide. Capybaras are widely managed as a source of animal protein, the results obtained require evaluating their possible role as a reservoir in trypanosomiasis and leishmaniasis. A 'One Health' approach through combination of ecological, veterinary and human health including the diagnosis and treatment of diseases of both humans and animals is essential for the development of more successful health programs.


Asunto(s)
Leishmania , Roedores/parasitología , Trypanosoma cruzi , Animales , Enfermedad de Chagas/veterinaria , Leishmania/genética , Leishmania/aislamiento & purificación , Enfermedades de los Roedores/parasitología , Trypanosoma cruzi/genética , Trypanosoma cruzi/aislamiento & purificación , Tripanosomiasis/veterinaria , Venezuela
14.
Acta Parasitol ; 66(3): 1048-1054, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33547991

RESUMEN

INTRODUCTION: Fascioliasis is caused in Venezuela by the trematode Fasciola hepatica, affecting herbivorous and human. The Venezuelan Andean region is endemic for bovine fascioliasis and its presence in humans is not known. The objective of this work was to detected positive cases of bovine and human fascioliasis by coprological and immunological techniques and determine the possible risk factors, in eight cattle farms of a Venezuelan Andean rural area. METHODS: We studied 143 samples of feces and sera of bovines, and 34 samples of feces and sera of humans. Feces were examined by several coprologic techniques, while sera were evaluated by ELISA using two antigens: crude extract (CE) and surface proteins (SP) of F. hepatica, which were previously standardized and validated. RESULTS: The frequency of fascioliasis in bovines was 21% by coprology, and 49.7% by SP-ELISA. The human detection was 0% by coprology, and 29.4% by SP-ELISA. There were statistical significative differences between cattle farms, regarding to the positive results by coprology and by SP-ELISA. About the possible risk factors, statistical association was found only with the presence of snails near or in the farms and consumption of non-channeled water (river, ditch or spring), both for cattle and for humans. CONCLUSION: The results showed that the studied area is endemic for bovine fascioliasis, the human has been in contact with F. hepatica and there are risk factors for the transmission of the parasite in the studied farms.


Asunto(s)
Enfermedades de los Bovinos , Fasciola hepatica , Fascioliasis , Animales , Bovinos , Enfermedades de los Bovinos/epidemiología , Ensayo de Inmunoadsorción Enzimática , Granjas , Fascioliasis/epidemiología , Fascioliasis/veterinaria , Heces , Humanos , Factores de Riesgo
15.
Rev Peru Med Exp Salud Publica ; 38(4): 621-626, 2021.
Artículo en Español | MEDLINE | ID: mdl-35385016

RESUMEN

The objective of this study was to determine ocular manifestations of toxocariasis in schoolchildren. A study was conducted in two schools in the Anzoátegui state in Venezuela in 2019. The ELISA test was used to determine IgG antibodies against Toxocara spp. The families completed a questionnaire, and the children were clinically evaluated by pediatricians and ophthalmologists. 118 children participated, 18.6% presented anti-Toxocara spp. The clinical manifestations with a statistically significant association were allergic reactions, epiphora, and decreased visual acuity. The ophthalmological evaluation found keratitis, uveitis, iritis, retinal granuloma, endophthalmitis, amaurosis, leukocoria, retinal detachment and endotropia. The findings show a high frequency of eye disease in children with toxocariasis from a state of Venezuela.


El objetivo de este estudio fue determinar manifestaciones oculares de la toxocariasis en escolares. Se realizó un estudio en dos escuelas del estado Anzoátegui en Venezuela en el 2019. Se empleó la prueba de ELISA para determinar los anticuerpos IgG contra Toxocara spp. Las familias completaron un cuestionario y los niños fueron evaluados clínicamente por pediatras y oftalmólogos. Participaron 118 niños, el 18,6% presentó anticuerpos anti-Toxocara spp. Las manifestaciones clínicas con asociación estadísticamente significativa fueron las reacciones alérgicas, epífora y disminución de la agudeza visual. En la evaluación oftalmológica se encontró queratitis, uveítis, iritis, granuloma retiniano, endoftalmitis, amaurosis, leucocoria, desprendimiento de retina y endotropía. Los hallazgos muestran una alta frecuencia de enfermedad ocular en niños con toxocariasis de un estado de Venezuela.


Asunto(s)
Infecciones Parasitarias del Ojo , Toxocariasis , Animales , Niño , Ensayo de Inmunoadsorción Enzimática , Humanos , Inmunoglobulina G , Toxocariasis/diagnóstico , Toxocariasis/epidemiología , Venezuela/epidemiología
16.
Acta Parasitol ; 66(1): 287-293, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32930930

RESUMEN

INTRODUCTION: We define a fluid library as a library of samples of different biological fluids (from humans, animals or vectors) collected and properly stored on filter paper, which allows retrospective studies, especially of diagnosis or detection of infectious agents in these samples, using different techniques. The objective of this work was the retrospective diagnosis of American trypanosomiasis by PCR in a Venezuelan endemic area using a fluid library. METHODS: A fluid library with samples that had been collected on filter paper, 5 years ago, was used for the detection of Trypanosoma cruzi DNA. 165 blood samples of humans, 30 samples of 25 animals (Didelphis marsupialis, Canis familiaris, Equus asinus and Felis catus) and 8 samples of vectors from endemic areas of Anzoátegui state, were analysed by PCR. RESULTS: The results revealed that 16.4% of the humans samples were positive, 11.1% of those detected positive were children younger than 10 years old, and 26.72% young people aged 11-20 years, suggesting that T. cruzi infection has been active for the past two decades. 56% of the animal samples showed amplification; Didelphis marsupialis 66%, Canis familiaris 54.5%, Equus asinus 50%, and Felis catus 33.3%. On the other hand, positivity (50%) was detected in the studied vectors, of which the 3 most important species in Venezuela (Rhodnius prolixus, Triatoma maculata and Panstrongylus geniculatus) were involved. CONCLUSIONS: The PCR using a fluid library allowed the detection of T. cruzi DNA in old samples from the three host of the epidemiological chain, suggesting that retrospective diagnosis can be made through this strategy and demonstrate that there has been active transmission, which helps to clarify the epidemiological situation in areas where there are no previous reports.


Asunto(s)
Enfermedad de Chagas , Trypanosoma cruzi , Adolescente , Animales , Gatos , Perros , Humanos , Insectos Vectores , Estudios Retrospectivos , Venezuela/epidemiología
17.
Int Microbiol ; 24(2): 141-147, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33156443

RESUMEN

Direct test over the gut material from triatomine vectors and xenodiagnosis over mammalian hosts are classical techniques for Trypanosoma cruzi parasitological diagnosis. Nevertheless, negative results can be a source of uncertainty. Experimental models have allowed evaluating the tissue invasion of different strains of T. cruzi, but conventional techniques for tissue biopsies involve time-consuming and elaborated procedures and have low sensitivity. Gut material of collected triatomines (microscopically negative) (n = 114), material of mammal xenodiagnoses (microscopically negative) (n = 138), and biopsy material (microscopically negative) from experimentally infected animals (n = 34) with isolates from endemic areas of Chagas' disease from Venezuela were used for DNA extraction and PCR for the amplification of kinetoplast DNA (kDNA) and satellite DNA (sDNA) of T. cruzi. Positive PCR was observed in 53.6% of collected triatomine material, 15.8% of parasitological negative xenodiagnosis material, and 70.6% in biopsies, revealing underestimation by the parasitological tests and the valour of this analysis with preserved material. Anzoátegui was the state with the highest percentage of infection, and the triatomine species Rhodnius prolixus and Panstrongylus geniculatus had the highest percentages of infection. Didelphis marsupialis and Canis familiaris were the most infected by T. cruzi revealed by PCR of xenodiagnosis material. In addition, the PCR technique allowed demonstrating the invasion of T. cruzi in all tissues analyzed, constituting a molecular marker of tissue invasion.


Asunto(s)
Enfermedad de Chagas/parasitología , ADN Protozoario/genética , Didelphis/parasitología , Insectos Vectores/parasitología , Triatominae/parasitología , Trypanosoma cruzi/genética , Animales , Biopsia , Enfermedad de Chagas/diagnóstico , Perros , Humanos , Insectos Vectores/clasificación , Reacción en Cadena de la Polimerasa , Triatominae/clasificación , Trypanosoma cruzi/aislamiento & purificación , Xenodiagnóstico
18.
Mol Biochem Parasitol ; 240: 111321, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32961205

RESUMEN

Cysticerci of Taenia solium cause cysticercosis, with neurocysticercosis (NCC) as the major pathology. Sensible and specific recombinant antigens would be an source of antigen for immunodiagnosis. The objective of this work was the molecular characterization and evaluation, of three news recombinant antigens (TsF78, TsP43 and TsC28), obtained by screening of a Taenia solium cDNA library. The three cDNA were analysed by bioinformatic programs, subcloned and expresed. The purified proteins were evaluated in ELISA using cyst fluid as control. TsF78 is filamina, TsP43 a peroxidase and TsC28 collagen XV. The sensitivity and specificity of the recombinant proteins were; TsF78 93.8 % and 95.0 %, TsP62 91.7 % and 93.3 %, TsC28 85.4 % and 93.3 %, respectively, while the cyst fluid showed a sensitivity of 87.5 % and a specificity of 76.7 %. Given its high sensitivity and specificity, the recombinant proteins TsF78 and TsP62 could be used in the diagnosis of cysticercosis.


Asunto(s)
Antígenos Helmínticos/inmunología , Cisticercosis/diagnóstico , Pruebas Inmunológicas , Proteínas Recombinantes/inmunología , Taenia solium/inmunología , Teniasis/diagnóstico , Animales , Antígenos Helmínticos/genética , Estudios de Casos y Controles , Cisticercosis/inmunología , Cisticercosis/microbiología , Humanos , Proteínas Recombinantes/genética , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Taenia solium/genética , Teniasis/inmunología , Teniasis/microbiología
19.
Acta Trop ; 207: 105445, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32224076

RESUMEN

The objective of this study was to identify and treat carriers of adult Taenia solium present in two rural Venezuelan communities through examination of faecal samples by coproscopical analysis, and by the application of a polyclonal and a monoclonal (VP-1) coproantigen ELISA. Both the polyclonal and monoclonal ELISA's were negative when tested with soluble extracts of adults of Ascaris lumbricoides, Hymenolepis nana and Trichuris trichura. The polyclonal ELISA was positive for soluble extracts adults of T. solium and T. saginata, whereas the monoclonal ELISA, which recognizes a glycoprotein, was restricted to T. solium, and was also negative with faecal samples from five cases of T. saginata adult infections. In the first community studied, Potrero Largo (Total population: 300), of 248 faecal samples examined, 2 individuals were positive for Taenia spp eggs by coproscopical analysis and the VP-1 ELISA, and yielded T. solium adults upon purging. In contrast, when the polyclonal coproAg ELISA was applied to the same 248 faecal samples, there were a considerable number of positives. Indeed, seven patients highly positive in the polyclonal ELISA did not yield a Taenia spp upon purging and were negative in the VP-1 ELISA. In the second community studied La Yuca (Total population 560), none of the 333 individuals who donated faeces was positive for Taenia spp eggs. Many, however, were infected with a range of intestinal helminth and protozoan parasites. A total of 76 faecal samples with representative intestinal parasite were then tested in the polyclonal and VP-1 assays. Of these, many gave an unacceptable number of significant optical densities in the polyclonal coproAg ELISA. In contrast, all were negative in the VP-1 ELISA, thus providing evidence for the species specificity of the VP-1 ELISA in faecal samples. These results with the VP-1 coproAg ELISA, although preliminary, justify further validation through the testing of more faecal samples from T. solium and T. saginata adult infected individuals.


Asunto(s)
Antígenos Helmínticos/análisis , Ensayo de Inmunoadsorción Enzimática/métodos , Taenia solium/aislamiento & purificación , Teniasis/diagnóstico , Adulto , Animales , Cisticercosis/epidemiología , Heces/parasitología , Femenino , Humanos , Masculino , Población Rural , Especificidad de la Especie , Taenia/inmunología , Taenia/aislamiento & purificación , Taenia solium/inmunología , Teniasis/epidemiología , Teniasis/parasitología , Venezuela/epidemiología , Adulto Joven
20.
Acta Trop ; 204: 105360, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32001248

RESUMEN

In Venezuela, areas endemic for schistosomiasis are of low transmission, with low parasite loads. Immunological tests often lack specificity and cannot differentiate past from present infections. Molecular tests are an alternative, although validation studies in endemic areas are needed. The aim of this study was to determine the performance of parasitological, immunological and molecular tests for the diagnosis of Schistosoma mansoni infection in low-transmission settings. A cross-sectional study was carried out in a rural community located in a schistosomiasis-endemic area of Venezuela to determine the prevalence and diagnostic performance of the Kato-Katz (KK) technique, Circumoval Precipitin Test (COPT), ELISA based on soluble egg antigen (ELISA-SEA) with and without treatment with sodium metaperiodate (ELISA-SEA-SMP), and PCR for amplification of the 121 bp highly repeated sequence of Schistosoma mansoni in faeces, urine and serum samples. The highest prevalence rates were obtained with ELISA-SEA (38.7%), COPT (33.3%), ELISA-SEA-SMP (31.5%), PCR on faeces (21.6%), and KK (17.1%), whereas PCR-based prevalence in urine was 6.2% and no positivity was detected in serum samples. Results showed that ELISA-SEA is the best method for the diagnosis of both current and former infections and that PCR on faeces is the best method for detecting recent transmission. The use of different tests that complement one another also allowed for a better diagnosis of Schistosoma mansoni infection, revealing a relatively high prevalence (33.8%) of schistosomiasis in a community of low transmission.


Asunto(s)
Antígenos Helmínticos/inmunología , Schistosoma mansoni/inmunología , Esquistosomiasis mansoni/epidemiología , Adolescente , Adulto , Factores de Edad , Animales , Niño , Estudios Transversales , Ensayo de Inmunoadsorción Enzimática , Heces/parasitología , Femenino , Humanos , Masculino , Carga de Parásitos , Prevalencia , Esquistosomiasis mansoni/diagnóstico , Sensibilidad y Especificidad , Venezuela/epidemiología , Adulto Joven
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