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1.
Mult Scler Relat Disord ; 34: 92-99, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31272071

RESUMO

BACKGROUND: Glatiramer acetate (GA) is a drug for Multiple Sclerosis (MS) treatment. However, its administration induces anti-drug antibodies (ADA). This research evaluated the sex differences in humoral response against GA in RR-MS patients METHODS: We analyzed 69 RR-MS patients, 43 treated with GA and 26 treated with IFN-ß. In all cases, the serum concentration of IgG antibodies was determined by UPLC, whereas the levels of IgG subclasses (1-4) of anti-GA antibodies and the concentration of IL-6 were detected by Multiplex and IL-10, and IFN-γ were detected by ELISA. RESULTS: The total concentration of IgG antibodies in patients did not differ between treatments, whereas the IgG levels of ADA were higher in male and female patients treated with GA (P ≤ 0.0001). The subclasses of IgG anti-GA antibodies were as follows: IgG4>>IgG3>IgG1>IgG2. Statistical analysis showed differences in the IgG2 (P ≤ 0.01) and IgG4 (P ≤ 0.0001) subclasses by sex in RR-MS patients. Levels of IgG1 subclass in male patients correlated positively with the circulatory levels of IL-6 (rs = 0.587, P ≤ 0.04) and IFN-γ (rs = 0.721, P ≤ 0.001), while IgG2 subclass levels in female patients correlated with serum levels of IFN-γ (rs = 0.628, P ≤ 0.0006). Statistical analysis did not detect correlations between the levels of IgG (1-4) subclasses of anti-GA antibodies and the evaluated clinical parameters. CONCLUSION: This study showed differences in the levels of IgG2 and IgG4 subclasses of ADA between male and female RR-MS patients. Further studies are necessary to take advantage of the clinical potential of this finding.


Assuntos
Acetato de Glatiramer/uso terapêutico , Imunoglobulina G/sangue , Imunossupressores/uso terapêutico , Esclerose Múltipla Recidivante-Remitente/imunologia , Esclerose Múltipla Recidivante-Remitente/terapia , Caracteres Sexuais , Adulto , Feminino , Humanos , Interferon gama/sangue , Masculino , Esclerose Múltipla Recidivante-Remitente/sangue
2.
Artif Intell Med ; 96: 93-106, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31164214

RESUMO

Prior art on automated screening of diabetic retinopathy and direct referral decision shows promising performance; yet most methods build upon complex hand-crafted features whose performance often fails to generalize. OBJECTIVE: We investigate data-driven approaches that extract powerful abstract representations directly from retinal images to provide a reliable referable diabetic retinopathy detector. METHODS: We gradually build the solution based on convolutional neural networks, adding data augmentation, multi-resolution training, robust feature-extraction augmentation, and a patient-basis analysis, testing the effectiveness of each improvement. RESULTS: The proposed method achieved an area under the ROC curve of 98.2% (95% CI: 97.4-98.9%) under a strict cross-dataset protocol designed to test the ability to generalize - training on the Kaggle competition dataset and testing using the Messidor-2 dataset. With a 5 × 2-fold cross-validation protocol, similar results are achieved for Messidor-2 and DR2 datasets, reducing the classification error by over 44% when compared to most published studies in existing literature. CONCLUSION: Additional boost strategies can improve performance substantially, but it is important to evaluate whether the additional (computation- and implementation-) complexity of each improvement is worth its benefits. We also corroborate that novel families of data-driven methods are the state of the art for diabetic retinopathy screening. SIGNIFICANCE: By learning powerful discriminative patterns directly from available training retinal images, it is possible to perform referral diagnostics without detecting individual lesions.

3.
J Immunol Res ; 2019: 2754920, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31223627

RESUMO

Transferon® is an immunomodulator made of a complex mixture of peptides from human dialyzable leucocyte extracts (hDLEs). Development of surrogate antibodies directed to hDLE is an indispensable tool for studies during process control and preclinical trials. These antibodies are fundamental for different analytical approaches, such as identity test and drug quantitation, as well as to characterize its pharmacokinetic and mechanisms of action. A previous murine study showed the inability of the peptides of Transferon® to induce antibody production by themselves; therefore, in this work, two approaches were tested to increase its immunogenicity: chemical conjugation of the peptides of Transferon® to carrier proteins and the use of a rabbit model. Bioconjugates were generated with Keyhole Limpet Hemocyanin (KLH) or Bovine Serum Albumin (BSA) through maleimide-activated carrier proteins. BALB/c mice and New Zealand rabbits were immunized with Transferon® conjugated to KLH or nonconjugated Transferon®. Animals that were immunized with conjugated Transferon® showed significant production of antibodies as evinced by the recognition of Transferon®-BSA conjugate in ELISA assays. Moreover, rabbits showed higher antibody titers when compared with mice. Neither mouse nor rabbits developed antibodies when immunized with nonconjugated Transferon®. Interestingly, rabbit antibodies were able to partially block IL-2 production in Jurkat cells after costimulation with Transferon®. In conclusion, it is feasible to elicit specific and functional antibodies anti-hDLE with different potential uses during the life cycle of the product.


Assuntos
Isoanticorpos/imunologia , Fator de Transferência/efeitos adversos , Adjuvantes Imunológicos , Animais , Formação de Anticorpos , Especificidade de Anticorpos/imunologia , Antígenos/administração & dosagem , Antígenos/imunologia , Ensaio de Imunoadsorção Enzimática , Humanos , Imunização , Imunoglobulina G/imunologia , Imunoglobulina G/isolamento & purificação , Isoanticorpos/isolamento & purificação , Masculino , Camundongos , Peptídeos/administração & dosagem , Peptídeos/imunologia , Coelhos , Fator de Transferência/imunologia , Fator de Transferência/uso terapêutico
4.
Artigo em Inglês | MEDLINE | ID: mdl-29696139

RESUMO

Recent Zika outbreaks in South America, accompanied by unexpectedly severe clinical complications have brought much interest in fast and reliable screening methods for ZIKV (Zika virus) identification. Reverse-transcriptase polymerase chain reaction (RT-PCR) is currently the method of choice to detect ZIKV in biological samples. This approach, nonetheless, demands a considerable amount of time and resources such as kits and reagents that, in endemic areas, may result in a substantial financial burden over affected individuals and health services veering away from RT-PCR analysis. This study presents a powerful combination of high-resolution mass spectrometry and a machine-learning prediction model for data analysis to assess the existence of ZIKV infection across a series of patients that bear similar symptomatic conditions, but not necessarily are infected with the disease. By using mass spectrometric data that are inputted with the developed decision-making algorithm, we were able to provide a set of features that work as a "fingerprint" for this specific pathophysiological condition, even after the acute phase of infection. Since both mass spectrometry and machine learning approaches are well-established and have largely utilized tools within their respective fields, this combination of methods emerges as a distinct alternative for clinical applications, providing a diagnostic screening-faster and more accurate-with improved cost-effectiveness when compared to existing technologies.

5.
Sci Rep ; 7(1): 12125, 2017 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-28935954

RESUMO

Glatiramer Acetate (GA) is an immunomodulatory medicine approved for the treatment of multiple sclerosis, whose mechanisms of action are yet to be fully elucidated. GA is comprised of a complex mixture of polypeptides with different amino acid sequences and structures. The lack of sensible information about physicochemical characteristics of GA has contributed to its comprehensiveness complexity. Consequently, an unambiguous determination of distinctive attributes that define GA is of highest relevance towards dissecting its identity. Herein we conducted a study of characteristic GA heterogeneities throughout its manufacturing process (process signatures), revealing a strong impact of critical process parameters (CPPs) on the reactivity of amino acid precursors; reaction initiation and polymerization velocities; and peptide solubility, susceptibility to hydrolysis, and size-exclusion properties. Further, distinctive GA heterogeneities were correlated to defined immunological and toxicological profiles, revealing that GA possesses a unique repertoire of active constituents (epitopes) responsible of its immunological responses, whose modification lead to altered profiles. This novel approach established CPPs influence on intact GA peptide mixture, whose physicochemical identity cannot longer rely on reduced properties (based on complete or partial GA degradation), providing advanced knowledge on GA structural and functional relationships to ensure a consistent manufacturing of safe and effective products.

6.
J Immunotoxicol ; 14(1): 169-177, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28707490

RESUMO

Transferon, a human dialyzable leukocyte extract (hDLE), is a biotherapeutic that comprises a complex mixture of low-molecular-weight peptides (< 10 kDa) and is used to treat diseases with an inflammatory component. Some biotherapeutics, including those composed of peptides, can induce anti-drug antibodies (ADA) that block or diminish their therapeutic effect. Nevertheless, few studies have evaluated peptide-derived drug immunogenicity. In this study, the immunogenicity of Transferon was examined in a murine model during an immunization scheme using the following adjuvants: Al(OH)3, incomplete Freund's adjuvant (IFA), or Titermax Gold. The inoculation scheme entailed three routes of administration (intraperitoneal, Day 1; subcutaneous, Day 7; and intramuscular, Day 14) using 200 µg Transferon/inoculation. Serum samples were collected on Day 21. Total IgG levels were quantitated by affinity chromatography, and specific antibodies against components of Transferon were analyzed by dot-blot and ELISA. Ovalbumin (OVA, 44 kDa) and peptides from hydrolyzed collagen (PFHC, < 17 kDa) were used as positive and negative controls, respectively, in the same inoculation scheme and analyses for Transferon. OVA, PFHC, and Transferon increased total IgG concentrations in mice. However, only IgG antibodies against OVA were detected. Based on the results, it is concluded that Transferon does not induce generation of specific antibodies against its components in this model, regardless of adjuvant and route of administration. These results support the safety of Transferon by confirming its inability to induce ADA in this animal model.


Assuntos
Misturas Complexas/administração & dosagem , Fatores Imunológicos/administração & dosagem , Imunoterapia/métodos , Inflamação/terapia , Peptídeos/administração & dosagem , Adjuvantes Imunológicos/administração & dosagem , Animais , Misturas Complexas/imunologia , Humanos , Imunoglobulina G/sangue , Fatores Imunológicos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Modelos Animais , Ovalbumina/imunologia , Peptídeos/imunologia
7.
IEEE J Biomed Health Inform ; 21(1): 193-200, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-26561488

RESUMO

Diabetic retinopathy (DR) is the leading cause of blindness in adults, but can be managed if detected early. Automated DR screening helps by indicating which patients should be referred to the doctor. However, current techniques of automated screening still depend too much on the detection of individual lesions. In this study, we bypass lesion detection, and directly train a classifier for DR referral. Additional novelties are the use of state-of-the-art mid-level features for the retinal images: BossaNova and Fisher Vector. Those features extend the classical Bags of Visual Words and greatly improve the accuracy of complex classification tasks. The proposed technique for direct referral is promising, achieving an area under the curve of 96.4%, thus, reducing the classification error by almost 40% over the current state of the art, held by lesion-based techniques.


Assuntos
Retinopatia Diabética/diagnóstico por imagem , Técnicas de Diagnóstico Oftalmológico , Interpretação de Imagem Assistida por Computador/métodos , Encaminhamento e Consulta , Algoritmos , Humanos
8.
Forensic Sci Int ; 268: 46-61, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27693826

RESUMO

As web technologies and social networks become part of the general public's life, the problem of automatically detecting pornography is into every parent's mind - nobody feels completely safe when their children go online. In this paper, we focus on video-pornography classification, a hard problem in which traditional methods often employ still-image techniques - labeling frames individually prior to a global decision. Frame-based approaches, however, ignore significant cogent information brought by motion. Here, we introduce a space-temporal interest point detector and descriptor called Temporal Robust Features (TRoF). TRoF was custom-tailored for efficient (low processing time and memory footprint) and effective (high classification accuracy and low false negative rate) motion description, particularly suited to the task at hand. We aggregate local information extracted by TRoF into a mid-level representation using Fisher Vectors, the state-of-the-art model of Bags of Visual Words (BoVW). We evaluate our original strategy, contrasting it both to commercial pornography detection solutions, and to BoVW solutions based upon other space-temporal features from the scientific literature. The performance is assessed using the Pornography-2k dataset, a new challenging pornographic benchmark, comprising 2000 web videos and 140h of video footage. The dataset is also a contribution of this work and is very assorted, including both professional and amateur content, and it depicts several genres of pornography, from cartoon to live action, with diverse behavior and ethnicity. The best approach, based on a dense application of TRoF, yields a classification error reduction of almost 79% when compared to the best commercial classifier. A sparse description relying on TRoF detector is also noteworthy, for yielding a classification error reduction of over 69%, with 19× less memory footprint than the dense solution, and yet can also be implemented to meet real-time requirements.


Assuntos
Algoritmos , Literatura Erótica , Máquina de Vetores de Suporte , Gravação em Vídeo , Humanos , Análise de Componente Principal
9.
Cancer Biol Ther ; 16(5): 684-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25802932

RESUMO

Nimotuzumab is a humanized IgG1 monoclonal antibody against the EGFR extracellular domain that has been evaluated in solid tumors as a single agent or in combination with chemotherapy and radiation. Cervical cancer patients who are refractory or progressive to first-line chemotherapy have a dismal prognosis, and no second- or third-line chemotherapy is considered standard. This pilot trial aimed to evaluate the efficacy and safety of nimotuzumab in 17 patients with pre-treated advanced refractory or progressive cervical cancer. Nimotuzumab was administered weekly at 200 mg/m(2) as single agent for 4 weeks (induction phase), then concurrent with 6 21-day cycles of gemcitabine (800 mg/m(2)) or cisplatin (50 mg/m(2)) for 18 weeks (concurrent phase) and then once every 2 weeks (maintenance phase). Nimotuzumab could be continued beyond disease progression. Seventeen patients were accrued and evaluated for safety and efficacy. The median number of nimotuzumab applications was 20 (5-96). The median number of chemotherapy cycles administered was 6 (1-6). No toxicity occurred during induction and maintenance phases (single agent nimotuzumab). In the concurrent phase, grade 3 toxicity events observed were leucopenia, anemia and diarrhea in 11.7%, 5.8% and 11.7% respectively. No complete or partial responses were observed. The stable disease (SD) rate was 35%. The median PFS and OS rates were 163 days (95% CI, 104 to 222), and 299 days (95% IC, 177 to 421) respectively. Nimotuzumab is well tolerated and may have a role in the treatment of advanced cervical cancer.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Neoplasias do Colo do Útero/tratamento farmacológico , Adulto , Idoso , Anticorpos Monoclonais Humanizados/administração & dosagem , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Prognóstico
10.
Artigo em Inglês | MEDLINE | ID: mdl-25569918

RESUMO

The biomedical community has shown a continued interest in automated detection of Diabetic Retinopathy (DR), with new imaging techniques, evolving diagnostic criteria, and advancing computing methods. Existing state of the art for detecting DR-related lesions tends to emphasize different, specific approaches for each type of lesion. However, recent research has aimed at general frameworks adaptable for large classes of lesions. In this paper, we follow this latter trend by exploring a very flexible framework, based upon two-tiered feature extraction (low-level and mid-level) from images and Support Vector Machines. The main contribution of this work is the evaluation of BossaNova, a recent and powerful mid-level image characterization technique, which we contrast with previous art based upon classical Bag of Visual Words (BoVW). The new technique using BossaNova achieves a detection performance (measured by area under the curve - AUC) of 96.4% for hard exudates, and 93.5% for red lesions using a cross-dataset training/testing protocol.


Assuntos
Retinopatia Diabética/diagnóstico , Interpretação de Imagem Assistida por Computador , Software , Humanos , Curva ROC , Máquina de Vetores de Suporte
11.
Infectio ; 16(1): 8-14, ene.-mar. 2012. graf, tab
Artigo em Espanhol | LILACS-Express | ID: lil-649987

RESUMO

Objetivo. El propósito del estudio fue evaluar el desempeño del método VERSANTHIV-1RNA 1.0 Assay® (kPCR) (Siemens), para la cuantificación de la carga viral en pacientes con VIH-1, en comparación con el método COBAS® AmpliPrep/COBAS TaqMan HIV-1 test®, v2.0 (Roche Diagnostics) (CAP/CTM). Métodos. Las muestras fueron tomadas en dos tubos con EDTA, de 60 pacientes remitidos por el médico tratante para pruebas de carga viral como parte de su control de rutina de VIH/sida, y fueron procesadas para la cuantificación del ARN del VIH-1 por ambas técnicas. Se hizo análisis de regresión y se calcularon los coeficientes de correlación de Pearson, y los de correlación y concordancia de Lin. Se evalúo la concordancia entre las dos técnicas mediante el método de Bland-Altman. Resultados. El promedio de la carga viral por el método CAP/CTM fue 3,2±1,4 long10 copias/ml y, por el método kPCR, 3,0±1,3 long10 copias/ml. El 86,7 % de muestras presentó diferencias entre los dos métodos, menores de 0,5 long10 copias/ml, y el 13,3 % presentó diferencias mayores. El coeficiente de correlación de Pearson entre los dos métodos fue de 0,97 (IC95% 0,95-0,99) y el índice kappa ponderado entre los dos métodos en diferentes rangos de concentración, fue de 0,91 (IC95% 0,87-0,96). El promedio de las diferencias entre las mediciones fue 0,22 long10 copias/ml (IC95% -0,45 a 0,89). Conclusión. Las dos técnicas evaluadas fueron comparables, con el método kPCR se observaron resultados más bajos.


Objective: The purpose of this study was to evaluate the performance of the kPCR VERSANT (™) 440 HIV-1RNA 3.0 Assay® (Siemens) method for the quantification of viral load in HIV-1 patients, compared to the COBAS AmpliPrep/COBASTaqMan HIV-1 test®, v. 2.0 (Roche Diagnostics) (CAP/CTM). Methods: Samples were taken in 2 tubes with EDTA, in 60 patients referred by the attending physician for viral load tests as part of their routine control of HIV/AIDS, and were processed for quantification of HIV-1 RNA by both techniques. A regression analysis, the Pearson correlation coefficient and agreement of Lin were done. The agreement between the two techniques was evaluated with the Bland Altman analysis. Results: The mean viral load by CAP/CTM was 3.2 ± 1.4 long10 copies/ml and by kPCR it was 3.0±1.3 10 copies/ml. Most samples (86.7%) showed differences between the two methods lower than 0.5 long10 copies/ml, and 13.3% presented greater differences. The Pearson correlation coefficient between the two methods was 0.97 (95% CI 0.95-0.99) and the weighted kappa index between the two methods, in different ranges of concentration, was 0.91 (95% CI 0.87-0.96). The average difference between measurements by both techniques was 0.22 long10 copies/ml, (IC 95% -0.45-0.89). Conclusion: Both techniques were comparable, although lower values of viral load were observed with kPCR.

14.
J Forensic Leg Med ; 16(4): 204-11, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19329077

RESUMO

Seventeen Y-chromosomal (DYS19, DYS389 I/II, DYS390, DYS391, DYS392, DYS393, DYS438, DYS439, DYS437, DYS448, DYS456, DYS458, DYS635, YGATA-H4 and DYS385a/b) short tandem repeat (STR) polymorphic systems were typed in three South West Colombian populations: Valle (short term for Valle del Cauca), Cauca and Nariño. DYS385a/b showed the highest gene diversity in the three populations. A total of 287 different Y-chromosome haplotypes were observed in the 308 males analyzed, and the haplotype diversity among populations was 0.9977. The most frequent haplotype was observed only three times and only nineteen others were observed two times. The highest gene diversity was found in Valle and the lowest in Cauca. Analysis of molecular variance (AMOVA) revealed that variation is mainly within populations (99.1%) in agreement with previous results in European populations. In conclusion, these populations could be pooled together in order to create one "Colombian-Mestizo" database for forensic use.


Assuntos
Cromossomos Humanos Y , Genética Populacional , Sequências de Repetição em Tandem , Colômbia , Impressões Digitais de DNA , Variação Genética , Haplótipos , Humanos , Masculino , Reação em Cadeia da Polimerase
15.
Biomedica ; 28(3): 357-70, 2008 Sep.
Artigo em Espanhol | MEDLINE | ID: mdl-19034359

RESUMO

INTRODUCTION: In Colombia, surnames are characters usually passed to the children by the father, and they have been compared to neutral alleles associated with the Y-chromosome. OBJECTIVE: Population frequencies were determined for 17 short tandem repeats (STR) DNA markers on the Y-chromosome to compare the two identity codes and define the correlation between haplotypes and surnames in each individual. MATERIALS AND METHODS: DNA was extracted from blood samples from 308 male individuals in provinces of Valle del Cauca, Cauca and Nariño, all in southwestern Colombia. Sample DNA was analyzed with the commercial kit AmpFLSTR Yfiler (Applied Biosystems) and examined for the following 17 Y-chromosome STR markers: DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385a/b, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635 and Y-GATA-H4. The frequencies of molecular haplotypes were associated with the surname reported by each individual, and a correlation table was constructed. Amerindian and European surnames were associated with the presence of allele DYS19/13, a characteristic of Amerindian populations. RESULTS: Allele frequencies were reported for each of the 17 STR markers in the southwestern region of Colombia-high genetic and haplotypic diversities were obtained. Approximately 40% of lineage inconsistencies were found when the molecular genotype was compared with the European or Amerindian surnames. CONCLUSIONS: Surnames must be used as population markers with reservation. The genetic evidence indicates that traditional genealogies based on surnames with or without documental support, may be inconsistant with their biological provenance.


Assuntos
Cromossomos Humanos Y , Genealogia e Heráldica , Nomes , Criança , Colômbia , Grupos Étnicos/genética , Frequência do Gene , Marcadores Genéticos , Haplótipos , Humanos , Masculino , Estatística como Assunto
16.
Biomédica (Bogotá) ; 28(3): 357-370, sept. 2008. tab
Artigo em Espanhol | LILACS | ID: lil-526140

RESUMO

Introducción. Es bien sabido que, entre los caracteres transmitidos por la línea paterna, el apellido se ha configurado en diferentes culturas como un carácter semejante a un alelo genético neutral asociado al cromosoma Y. Objetivo. En este estudio se determinaron las frecuencias en la población de 17 STR del cromosoma Y en 308 individuos provenientes de las poblaciones de los departamentos del Valle del Cauca, Cauca y Nariño. Además, se propuso definir la correlación de los haplotipos obtenidos en cada individuo con su apellido paterno, para comparar estos dos códigos de identidad. Materiales y métodos. Se extrajo el ADN de cada individuo a partir de sangre periférica y se utilizó el estuche comercial AmpFLSTR® Yfiler™ (Applied Biosystems) para tipificarlo. Los resultados de los haplotipos moleculares se compararon con los apellidos reportados por cada individuo y se asociaron apellidos amerindios y europeos con haplotipos que incluyeran o no el marcador DYS19/13, característico de la población amerindia. Resultados. Se reportan las frecuencias alélicas de cada uno de los 17 marcadores del cromosoma Y analizados en esta región de Colombia, así como la diversidad génica y haplotípica hallada en los tres departamentos. Al comparar los resultados obtenidos a nivel molecular con los apellidos de origen europeo o amerindio reportados por cada uno de los individuos, se encontró cerca de 40 por ciento de inconsistencia de linaje. Conclusiones. La utilización del apellido como marcador de población debe hacerse con cautela, por cuanto las genealogías fundamentadas en éstos pueden no corresponder al origen biológico de sus portadores.


Assuntos
Código Genético , Genótipo , Índios Sul-Americanos , Cromossomo Y
17.
Rev Inst Med Trop Sao Paulo ; 49(3): 159-64, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17625693

RESUMO

A parasitological, clinical, serological and molecular cross-sectional study carried out in a highly endemic malaria area of Rio Negro in the Amazon State, Brazil, revealed a high prevalence of asymptomatic Plasmodium vivax infection. A total of 109 persons from 25 families were studied in five villages. Ninety-nine inhabitants (90.8%) had at least one previous episode of malaria. Serology showed 85.7% and 46.9% of positivity when P. falciparum antigens and P. vivax MSP-1, respectively, were used. Twenty blood samples were PCR positive for P. vivax (20.4%) and no P. falciparum infection was evidenced by this technique. No individual presenting positive PCR reaction had clinical malaria during the survey neither in the six months before nor after, confirming that they were cases of asymptomatic infection. Only one 12 year old girl presented a positive thick blood smear for P. vivax. This is the first description of asymptomatic Plasmodium infection in this area studied.


Assuntos
Malária Vivax/epidemiologia , Plasmodium vivax , Adolescente , Adulto , Idoso , Animais , Anticorpos Antiprotozoários/sangue , Brasil/epidemiologia , Criança , Pré-Escolar , Estudos Transversais , DNA de Protozoário/análise , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Malária Vivax/diagnóstico , Masculino , Pessoa de Meia-Idade , Plasmodium vivax/genética , Plasmodium vivax/imunologia , Reação em Cadeia da Polimerase , Prevalência
18.
Rev. Inst. Med. Trop. Säo Paulo ; 49(3): 159-164, May-June 2007. mapas, tab
Artigo em Inglês | LILACS | ID: lil-454763

RESUMO

A parasitological, clinical, serological and molecular cross-sectional study carried out in a highly endemic malaria area of Rio Negro in the Amazon State, Brazil, revealed a high prevalence of asymptomatic Plasmodium vivax infection. A total of 109 persons from 25 families were studied in five villages. Ninety-nine inhabitants (90.8 percent) had at least one previous episode of malaria. Serology showed 85.7 percent and 46.9 percent of positivity when P. falciparum antigens and P. vivax MSP-1, respectively, were used. Twenty blood samples were PCR positive for P. vivax (20.4 percent) and no P. falciparum infection was evidenced by this technique. No individual presenting positive PCR reaction had clinical malaria during the survey neither in the six months before nor after, confirming that they were cases of asymptomatic infection. Only one 12 year old girl presented a positive thick blood smear for P. vivax. This is the first description of asymptomatic Plasmodium infection in this area studied.


Um estudo seccional parasitológico, clínico, sorológico e molecular, realizado em uma área altamente endêmica para malária, no Rio Negro, Estado do Amazonas, revela alta prevalência de infecção assintomática por Plasmodium vivax. Um total de 109 pessoas de 25 famílias residentes em cinco comunidades do Rio Padauiri, afluente do Rio Negro, foram estudadas. Noventa por cento dos habitantes (90,8 por cento) tinham tido pelo menos um episodio prévio de malária. A sorologia mostrou 85,7 por cento e 46,9 por cento de positividade quando antígenos de P. falciparum e P. vivax MSP-1, foram respectivamente usados. Vinte amostras de sangue submetidas ao PCR foram positivas para P. vivax (20,4 por cento), entretanto, nenhuma foi positiva para o P. falciparum por esta técnica. Nenhum paciente com PCR positivo durante o inquérito e seis meses antes ou depois teve manifestações clínicas de malária, portanto, podemos afirmar que eram assintomáticos. Somente uma criança de 12 anos de idade teve gota espessa positiva para P. vivax. Esta é a primeira descrição de infecção assintomática por Plasmodium na área estudada.


Assuntos
Humanos , Animais , Masculino , Feminino , Pré-Escolar , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Malária Vivax/epidemiologia , Plasmodium vivax , Anticorpos Antiprotozoários/sangue , Brasil/epidemiologia , Estudos Transversais , DNA de Protozoário/análise , Ensaio de Imunoadsorção Enzimática , Malária Vivax/diagnóstico , Reação em Cadeia da Polimerase , Prevalência , Plasmodium vivax/genética , Plasmodium vivax/imunologia
19.
Gene ; 376(2): 224-30, 2006 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-16716539

RESUMO

The recent evolution of Plasmodium falciparum is at odds with the extensive polymorphism found in most genes coding for antigens. Here, we examined the patterns and putative mechanisms of sequence diversification in the merozoite surface protein-2 (MSP-2), a major malarial repetitive surface antigen. We compared the msp-2 gene sequences from closely related clones derived from sympatric parasite isolates from Brazilian Amazonia and used microsatellite typing to examine, in these same clones, the haplotype background of chromosome 2, where msp-2 is located. We found examples of msp-2 sequence rearrangements putatively created by nonreciprocal recombinational events, such as replication slippage and gene conversion, while maintaining the chromosome haplotype. We conclude that these nonreciprocal recombination events may represent a major source of antigenic diversity in MSP-2 in P. falciparum populations with low rates of classical meiotic recombination.


Assuntos
Antígenos de Protozoários/genética , DNA de Protozoário/genética , Vacinas Antimaláricas , Plasmodium falciparum/genética , Plasmodium falciparum/isolamento & purificação , Proteínas de Protozoários/genética , Alelos , Animais , Antígenos de Protozoários/imunologia , Sequência de Bases , Brasil , Mapeamento Cromossômico , Cromossomos , Simulação por Computador , DNA de Protozoário/química , Evolução Molecular , Conversão Gênica , Genes de Insetos , Marcadores Genéticos , Haplótipos , Desequilíbrio de Ligação , Cadeias de Markov , Repetições de Microssatélites , Dados de Sequência Molecular , Plasmodium falciparum/imunologia , Proteínas de Protozoários/imunologia , Análise de Sequência de DNA
20.
Forensic Sci Int ; 137(1): 67-73, 2003 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-14550617

RESUMO

Genotype polymorphism studies at the 13 loci STRs included in the combined DNA index system [CODIS and PCR-based short tandem repeat loci, in: Proceedings of the Second European Symposium on Human Identification, Promega Corporation, Madison, WI, 1998, pp. 73-88; J. Forensic Sci. 46 (2001) 453] (CODIS: D3S1358, HUMvWA31, HUMFGA, D8S1179 D21S11, D18S51, D5S818, D13S317, D7S820, HUMTH01, HUMTPOX, HUMCSF1PO and D16S539) were carried out in a sample of 1429 unrelated Colombian individuals belonging to 25 different departments. As many other countries in Latino-America, Colombia shows an important admixture component, basically integrated by Amerindians, European-descendants and African-descendants. Due to the fact that only partial population analyses have been carried out in the country, the main aim of the present analysis is to establish a database of forensic interest based on the widely used CODIS systems covering the main Colombian regions.


Assuntos
Frequência do Gene , Genética Populacional , Polimorfismo Genético , Sequências de Repetição em Tandem , Colômbia , Impressões Digitais de DNA/métodos , Grupos Étnicos/genética , Genótipo , Humanos , Reação em Cadeia da Polimerase
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