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1.
Environ Res ; 228: 115887, 2023 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-37054836

RESUMEN

Coastal ecosystems are particularly vulnerable to terrestrial inputs from human-impacted areas. The prevalence of wastewater treatment plants, unable to remove contaminants such as pharmaceuticals (PhACs), leads to their continuous input into the marine environment. In this paper, the seasonal occurrence of PhACs in a semi-confined coastal lagoon (the Mar Menor, south-eastern Spain) was studied during 2018 and 2019 by evaluating their presence in seawater and sediments, and their bioaccumulation in aquatic organisms. Temporal variation in the contamination levels was evaluated by comparison to a previous study carried out between 2010 and 2011 before the cessation of permanent discharges of treated wastewater into the lagoon. The impact of a flash flood event (September 2019) on PhACs pollution was also assessed. A total of seven compounds (out of 69 PhACs analysed) were found in seawater during 2018-2019, with a limited detection frequency (<33%) and concentrations (up to 11 ng/L of clarithromycin). Only carbamazepine was found in sediments (ND-1.2 ng/g dw), suggesting an improved environmental quality in comparison to 2010-2011 (when 24 and 13 compounds were detected in seawater and sediments, respectively). However, the biomonitoring of fish and molluscs showed a still remarkable accumulation of analgesic/anti-inflammatory drugs, lipid regulators, psychiatric drugs and ß-blocking agents, albeit not higher than in 2010. The flash flood event from 2019 increased the prevalence of PhACs in the lagoon, compared to the 2018-2019 sampling campaigns, especially in the upper water layer. After the flash flood the antibiotics clarithromycin and sulfapyridine yielded the highest concentrations ever reported in the lagoon (297 and 145 ng/L, respectively), alongside azithromycin in 2011 (155 ng/L). Flash flood events associated with sewer overflows and soil mobilisation, which are expected to increase under climate change scenarios, should be considered when assessing the risks posed by pharmaceuticals to vulnerable aquatic ecosystems in the coastal areas.


Asunto(s)
Ecosistema , Contaminantes Químicos del Agua , Humanos , Animales , Monitoreo del Ambiente , Inundaciones , Bioacumulación , Claritromicina , Contaminantes Químicos del Agua/análisis , Preparaciones Farmacéuticas
2.
Genet Mol Res ; 14(2): 6897-905, 2015 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-26125897

RESUMEN

The objective of this study was to perform a study of fragile X syndrome (FXS) in São Luís, Maranhão, in males residing in five specialized institutions. Two hundred thirty-eight males with intel-lectual disability of unknown etiology participated in this study. Blood samples were processed and stored until DNA extraction. Screening for FMR1 gene mutations was performed using non-isotopic polymerase chain reaction amplification and DNA sequencing using an ABI Prism 3130 automated sequencer. Two individuals (0.84%) were positive for FMR1 mutations. One had a mutation due to expansion of the CGG repeat beyond normal levels and the other had a deletion in exon 1 of the FMR1 gene, which was confirmed by sequencing. Both probands were over 18 years old, which demonstrates the late diagnosis of the condition in these individuals and reinforces the need to implement ef-fective programs for early diagnosis of FXS in the state of Maranhão. We found that FXS might be transmitted in the families of the two indi-viduals bearing the mutation, and that it is important to understand the mutation dynamics to provide better counseling to the family members of these two individuals.


Asunto(s)
ADN/genética , Proteína de la Discapacidad Intelectual del Síndrome del Cromosoma X Frágil/genética , Síndrome del Cromosoma X Frágil/genética , Pruebas Genéticas , Mutación , Adolescente , Adulto , Brasil , Niño , Preescolar , ADN/aislamiento & purificación , Síndrome del Cromosoma X Frágil/diagnóstico , Síndrome del Cromosoma X Frágil/patología , Asesoramiento Genético , Humanos , Institucionalización , Masculino , Persona de Mediana Edad , Linaje , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN
3.
Genet Mol Res ; 14(4): 19094-101, 2015 Dec 29.
Artículo en Inglés | MEDLINE | ID: mdl-26782561

RESUMEN

Visceral leishmaniasis (VL) is one of the seven priority endemic diseases in the world. The clinical outcome of many infections is not only dependent on the pathogenic organism, but also on the genetic variability of the host susceptibility to infection. Mannose-binding lectin (MBL) is a protein that plays an important role in the innate immune system. The aim of this study was to compare the serum levels of MBL between healthy controls and carriers of VL. The VL cases were recruited randomly from the main hospitals and referral outpatient clinics for VL in São Luís, and from home visits. Determination of MBL protein levels was performed by enzyme-linked immunosorbent assay. Of the 161 patients with VL and the 161 healthy controls, 60.9 and 67.1% had high levels of MBL, respectively. There was no significant difference in MBL levels between cases and controls. Low socioeconomic status and living conditions are conducive to the occurrence of VL. Owing to the small number of existing studies, it is extremely important to conduct further studies on MBL levels and susceptibility to VL, especially in regions where the disease is endemic, such as Maranhão, Brazil.


Asunto(s)
Leishmaniasis Visceral/sangre , Lectina de Unión a Manosa/sangre , Adolescente , Adulto , Anciano , Brasil , Estudios de Casos y Controles , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Adulto Joven
4.
Sci Total Environ ; 905: 166828, 2023 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-37690766

RESUMEN

This study investigates the role of floating plastics as integrative samplers of organic contaminants. To this end, plastics items were collected in two Western Mediterranean coastal areas: the Mar Menor lagoon, and the last transect of Ebro river. Floating plastics were identified and characterized by attenuated total reflection Fourier-transform infrared spectrometry. Then, organic contaminants were extracted from plastic items by ultrasonic extraction with methanol, and the concentrations of 168 regulated and emerging contaminants were analysed. These compounds were analysed by stir bar sorptive extraction coupled to gas chromatography-mass spectrometry (GC-MS), except for bisphenol analogues, which were analysed with a ultraperformance liquid chromatography pump coupled to a triple quadrupole mass spectrometer (UHPLC-MS/MS), and pharmaceutical compounds, determined by UPLC coupled to hybrid triple quadrupole-linear ion trap mass spectrometer (UPLC-MS/MS). All the contaminants groups considered were detected in the samples, being particularly relevant the contribution of plastic additives. The most frequently detected contaminants were UV-filters, PAHs, pharmaceuticals and synthetic musks. Apart from plasticizers, the individual contaminants octocrylene, homosalate, galaxolide, salycilic acid and ketoprofen were frequently detected in plastics items. The results pointed out to urban and touristic activities as the main sources of pollution in the coastal areas investigated. The utility of floating plastics as integrative samplers for the detection of organic contaminants in aquatic ecosystems has been demonstrated.


Asunto(s)
Espectrometría de Masas en Tándem , Contaminantes Químicos del Agua , Cromatografía Liquida , Ecosistema , Cromatografía de Gases y Espectrometría de Masas , Contaminantes Químicos del Agua/análisis , Plásticos/análisis
5.
J Hazard Mater ; 458: 131904, 2023 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-37356174

RESUMEN

Pharmaceuticals and microplastics constitute potential hazards in aquatic systems, but their combined effects and underlying toxicity mechanisms remain largely unknown. In this study, a simultaneous characterization of bioaccumulation, associated metabolomic alterations and potential recovery mechanisms was performed. Specifically, a bioassay on Mediterranean mussels (Mytilus galloprovincialis) was carried out with polyethylene microplastics (PE-MPLs, 1 mg/L) and citalopram or bezafibrate (500 ng/L). Single and co-exposure scenarios lasted 21 days, followed by a 7-day depuration period to assess their potential recovery. PE-MPLs delayed the bioaccumulation of citalopram (lower mean at 10 d: 447 compared to 770 ng/g dw under single exposure), although reaching similar tissue concentrations after 21 d. A more limited accumulation of bezafibrate was observed overall, regardless of PE-MPLs co-exposure (

Asunto(s)
Mytilus , Contaminantes Químicos del Agua , Animales , Microplásticos/metabolismo , Polietileno/metabolismo , Bezafibrato/metabolismo , Bezafibrato/farmacología , Plásticos/metabolismo , Citalopram/metabolismo , Citalopram/farmacología , Bioacumulación , Preparaciones Farmacéuticas/metabolismo , Contaminantes Químicos del Agua/análisis
6.
Eur J Neurol ; 17(12): 1479-81, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20443975

RESUMEN

BACKGROUND AND PURPOSE: Mutations in the leucine-rich repeat kinase 2 gene (LRRK2) have been associated with Parkinson's disease (PD), and the majority of the pathogenic variants are located in the ROC and MAPKKK domains. METHODS: Exons 29-31 and 38-44 (ROC and MAPKKK domains) were sequenced in 204 patients with PD, mostly Brazilian. RESULTS: We identified four polymorphisms, a novel silent variant p.R1398R and four substitutions: p.T1410M, p.G2019S, p.Y2189C and the novel variant p.C2139S. CONCLUSIONS: The most prevalent mutation was the p.G2019S (2.4%). We consider that the p.T1410M and the p.Y2189C variants are probably polymorphisms and that the p.C2139S mutation is potentially pathogenic.


Asunto(s)
Exones , Enfermedad de Parkinson/genética , Proteínas Serina-Treonina Quinasas/genética , Anciano , Brasil , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina , Masculino , Persona de Mediana Edad , Mutación , Análisis de Secuencia de ADN/métodos
7.
Genet Mol Res ; 9(3): 1392-7, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20662153

RESUMEN

We determined whether ADRbeta3 polymorphism is associated with obesity-related traits in 140 obese patients. Molecular analysis was performed by PCR and RFLP. Individuals carrying the Arg64 allele had a lower waist-to-hip ratio, higher adiponectin and high-density lipoprotein cholesterol levels, and a tendency towards lower blood pressure. In contrast, Trp64/Trp64 carriers were at greater risk for dysmetabolic phenotypes (odds ratio = 2.88, P = 0.03).


Asunto(s)
Enfermedades Cardiovasculares/complicaciones , Predisposición Genética a la Enfermedad , Síndrome Metabólico/complicaciones , Obesidad/complicaciones , Polimorfismo de Nucleótido Simple/genética , Receptores Adrenérgicos beta 3/genética , Adolescente , Adulto , Anciano , Sustitución de Aminoácidos/genética , Brasil , Enfermedades Cardiovasculares/genética , Femenino , Humanos , Modelos Logísticos , Masculino , Síndrome Metabólico/genética , Persona de Mediana Edad , Obesidad/genética , Factores de Riesgo , Adulto Joven
8.
Dis Markers ; 25(3): 149-57, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-19096127

RESUMEN

Polymorphisms in genes encoding folate metabolizing enzymes have been linked to an increased risk of maternal chromosomal nondisjunction in several populations. With the purpose of evaluating this relationship, we compared the frequencies of 677C>T and 1298A>C polymorphisms in the methylenetetrahydrofolate reductase gene (MTHFR) and 66A>G in the methionine synthase reductase gene (MTRR) between 103 young mothers of Down syndrome (DS) individuals and 108 control mothers, whose offspring was karyotypically normal, correlating it with an estimative of folate and - related micronutrients levels intake. Maternal and paternal transmission frequencies of MTHFR 677T allele were also examined to access potential parent-of-origin effects. PCR-RFLP for genomic DNA was accomplished and allele/genotype frequencies differences were determined using the x(2) test, whereas pattern of transmission of the MTHFR 677 allele was analyzed by transmission disequilibrium test. None of the polymorphisms seemed to be more frequent in case mothers than in controls, either individually or combined. The estimative of nutritional intake revealed that folate consumption median was inadequate in both groups, whereas methionine and zinc consumption medians were significantly greater in control mothers. It suggests that such interaction between genetic profile and environment could predispose this sub group of women to have a DS child. Additional studies focusing the interaction between nutritional intakes, biochemical data and folate pathway polymorphisms are needed to confirm the present results. The possibility of neutralize the biochemical negative effects of folate-related polymorphisms through oral supplementation could provide new targets for DS prevention.


Asunto(s)
Síndrome de Down/etiología , Síndrome de Down/genética , Ácido Fólico/metabolismo , Desnutrición/complicaciones , Desnutrición/metabolismo , Adolescente , Adulto , Alelos , Estudios de Casos y Controles , Síndrome de Down/metabolismo , Femenino , Ferredoxina-NADP Reductasa/genética , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Humanos , Recién Nacido , Masculino , Desnutrición/genética , Metilenotetrahidrofolato Reductasa (NADPH2)/genética , Madres , Polimorfismo de Nucleótido Simple , Embarazo , Factores de Riesgo , Adulto Joven
9.
Eur J Hum Genet ; 15(1): 10-7, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17047674

RESUMEN

Significant evidences have brought new insights on the mechanisms by which epigenetic machinery proteins regulate gene expression, leading to a redefinition of chromatin regulation in terms of modification of core histones, DNA methylation, RNA-mediated silencing pathways, action of methylation-dependent sensitive insulators and Polycomb/Trithorax group proteins. Consistent with these fundamental aspects, an increasing number of human pathologies have been found to be associated with aberrant epigenetics regulation, including cancer, mental retardation, neurodegenerative symptoms, imprinting disorders, syndromes involving chromosomal instabilities and a great number of human life-threatening diseases. The possibility of reversing epigenetic marks, in contrast to genetic code, may provide new pharmacological targets for emerging therapeutic intervention.


Asunto(s)
Epigénesis Genética , Enfermedades Genéticas Congénitas , Ensamble y Desensamble de Cromatina , Metilación de ADN , Histonas/metabolismo , Humanos , Neoplasias/genética , Enfermedades del Sistema Nervioso/genética , Proteínas del Grupo Polycomb , Proteínas Represoras/genética
10.
Genet Mol Res ; 6(4): 1035-43, 2007 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-18273796

RESUMEN

Obesity is due to the combined effects of genes, environment, lifestyle, and the interactions of these factors. The adrenergic receptor beta3 (beta3-AR), leptin (LEP) and leptin receptor (LEPR) genes have been intensively evaluated in the search of variants that could be related to obesity and its cardiometabolic complications. The results of most of these studies have been controversial. In the present study, we investigated the relationship of the beta3-AR p.W64R, LEP c.-2548G>A and LEPR p.Q223R gene variants with body mass index (BMI), in Brazilian subjects of different genetic backgrounds and ethnic origins. Two hundred obese patients (60 males, 140 females, BMI > or = 30 kg/m2) were screened and compared to 150 lean healthy subjects (63 males, 87 females, BMI < or = 24 kg/m2). Genomic DNA was extracted and amplified by polymerase chain reaction. Polymerase chain reaction products were digested with specific restriction enzymes and separated by electrophoresis. There was no significant difference in the genotype frequency of the beta3-AR p.W64R and the LEP c.-2548G>A polymorphisms, between lean and obese subjects. However, the genotype and allele frequencies of the LEPR p.Q223R variant were significantly different between the normal weight and obese groups. Haplotype analysis has shown an association between the G/G allelic combination of c.-2548G>A LEP and c.668A>G LEPR, in obese subjects. Our results suggest that genetic variability in the leptin receptor is associated with body weight regulation, the LEPR p.Q223R variant being related to BMI increase. The haplotype combination of LEP c.-2548G>A and LEPR p.Q223R variants was related to a 58% increase in obesity risk.


Asunto(s)
Variación Genética , Leptina/genética , Obesidad/genética , Receptores Adrenérgicos beta 3/genética , Receptores de Leptina/genética , Adolescente , Adulto , Anciano , Alelos , Sustitución de Aminoácidos , Índice de Masa Corporal , Brasil , Estudios de Casos y Controles , ADN/genética , Femenino , Frecuencia de los Genes , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Obesidad/patología , Reacción en Cadena de la Polimerasa , Polimorfismo de Nucleótido Simple
11.
Sci Total Environ ; 356(1-3): 125-42, 2006 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-16181662

RESUMEN

Pb concentration and Pb isotopic composition are known to represent powerful tools to investigate the history of Pb pollution in water and sediments. In this paper, we present and discuss the results of a detailed study of sediments deposited in the Paranoá Lake, a 44-year-old artificial reservoir in Brasília, central Brazil. Pb concentration and isotopic composition of the sediments were obtained by ID-TIMS, on three different sample fractions: leachate, residue, and bulk sample. The leachate phase has proven to be most efficient to distinguish between anthropogenic and natural Pb inputs. In the Paranoá lake, important sources of contamination were recognized, producing higher Pb concentrations (max. 37.68 ppm) and significant variations in Pb isotopic composition, relative to the regional geogenic background. Contamination of the sediments due to anthropogenic activity produced less radiogenic Pb isotopic compositions (206Pb/207Pb=1.15-1.17), compared with the regional natural composition (206Pb/207Pb=1.19-1.25). 210Pb analyses along one bore hole which sampled the entire sediment section indicated a sedimentation rate of 8.2+/-1.8 mm/year. The combined use of the 210Pb ages and Pb isotopic compositions of these samples revealed three distinct periods in the lake history: (1) the period of the time formation of the lake in 1959 until ca. 1970 was characterized by the deposition of sediments displaying more radiogenic Pb isotopic signature, (2) the time interval from the start of the process of eutrophication at 1970, until 1995, was characterized by the deposition of sediments having less radiogenic average compositions, and (3) from 1995 until the present represents a period of recovery of water quality, after two sewage treatment stations started to operate.


Asunto(s)
Agua Dulce/análisis , Sedimentos Geológicos/química , Plomo/análisis , Contaminantes Químicos del Agua/análisis , Brasil , Monitoreo del Ambiente , Espectrometría de Masas , Difracción de Rayos X
12.
Hum Mutat ; 18(2): 157-62, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11462240

RESUMEN

FRAXE (FMR2) is a fragile site associated with mental impairment located in Xq28, 600 kb distal to FRAXA (FMR1), the fragile X syndrome fragile site. The FRAXE mutation is an expansion of a CCG repeat that results in methylation of a nearby CpG island. FRAXE alleles could be divided into four categories: normal (6-30 CCG repeats), intermediate (31-60 CCG repeats), premutation (61-200 CCG repeats), and full mutation (over 200 repeats). We have developed a non-isotopic polymerase chain reaction (PCR)-based assay for the identification of FRAXE full mutation alleles among mentally impaired men. In this novel PCR test for the FRAXE locus, we used three primers to permit an amplification of a 223 bp monomorphic internal control fragment in addition to the amplification of a 419 bp (CCG)(16) FRAXE locus band. A linear series of 93 male patients referred for FRAXE testing but found to be negative for the (CCG)(n) expansion in the FMR2 gene by Southern blotting analysis were retested by our PCR technique. In addition, we analyzed two positive controls consisting of a FRAXE fully mutated male and one male with a Xq terminal deletion. The developed PCR test showed accuracy of 100% in the normal individuals retested by PCR analysis, as well as in the two positive control samples utilized, in which the strategy of multiplex amplification worked as expected. Although not suitable for medical diagnosis of females and mosaics, it constitutes an important strategy for PCR typing and for FRAXE population screening.


Asunto(s)
Síndrome del Cromosoma X Frágil/genética , Pruebas Genéticas/métodos , Discapacidad Intelectual/genética , Mutación/genética , Proteínas Nucleares/genética , Transactivadores/genética , Alelos , Southern Blotting , Islas de CpG/genética , Síndrome del Cromosoma X Frágil/diagnóstico , Humanos , Discapacidad Intelectual/diagnóstico , Masculino , Datos de Secuencia Molecular , Mosaicismo/genética , Reacción en Cadena de la Polimerasa/métodos , Sensibilidad y Especificidad , Expansión de Repetición de Trinucleótido/genética
13.
J Neurol Sci ; 62(1-3): 171-80, 1983 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-6668472

RESUMEN

Creatine kinase (CK) is the enzyme most often utilized for the detection of carriers of the gene for X-linked muscular dystrophies. In 1974, pyruvate kinase (PK) levels were also found to be increased in these carriers. The objective of the present study, carried out on 77 women related to patients with Duchenne muscular dystrophy (DMD), was to compare the efficiency of the two enzymes in the detection process. Of the 11 obligate heterozygotes for the DMD gene in the group, 8 exhibited elevated mean CK levels, 6 had elevated mean PK levels, and 9 had elevated mean levels of at least one of the enzymes. Among the mothers of isolated patients, 2/13 had elevated mean CK levels, 3/13 had elevated mean PK levels, and 5/13 had elevated mean levels of at least one of these enzymes. Thus, the study confirms data obtained by other investigators indicating that the use of PK can increase the detection rate of carriers of the gene for X-linked muscular dystrophies.


Asunto(s)
Creatina Quinasa/sangre , Distrofias Musculares/genética , Piruvato Quinasa/sangre , Cromosoma X , Pruebas Enzimáticas Clínicas , Femenino , Tamización de Portadores Genéticos , Ligamiento Genético , Humanos , Distrofias Musculares/diagnóstico
14.
Int J Mol Med ; 3(6): 639-45, 1999 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10341296

RESUMEN

Fragile X syndrome is the most common form of inherited mental retardation currently known, associated with a wide range of developmental disabilities in both males and females, caused by a large expansion of a (CGG)n repeat in the first exon of the FMR1 gene. Fragile X syndrome occurs in all racial and ethnic groups, and it is a condition of major epidemiological importance among mentally handicapped males. Therefore, this disease must be considered in the differential diagnosis of any child with developmental delay, mental retardation or learning disability. The fragile X syndrome is due to the shutdown of the FMR1 gene transcription, and the pathogenesis of this syndrome is a consequence of absence of the protein product of the FMR1 gene (FMRP). Since the great majority of fragile X patients have the same type of mutation in a specific location of the gene, molecular analysis is extremely accurate for diagnosis of the disease, and important for genetic counseling of family members. Others genetic disorders are also caused by expanded trinucleotide repeats.


Asunto(s)
Síndrome del Cromosoma X Frágil/diagnóstico , Síndrome del Cromosoma X Frágil/genética , Proteínas de Unión al ARN , Femenino , Efecto Fundador , Proteína de la Discapacidad Intelectual del Síndrome del Cromosoma X Frágil , Asesoramiento Genético , Humanos , Discapacidad Intelectual/diagnóstico , Discapacidad Intelectual/genética , Masculino , Mutación , Proteínas del Tejido Nervioso/genética , Fenotipo , Repeticiones de Trinucleótidos/genética
15.
Int J Mol Med ; 5(1): 67-9, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10601577

RESUMEN

The folate-sensitive fragile site FRAXE is located in proximal Xq28 of the human X chromosome and lies approximately 600 kb distal to the fragile X syndrome (FRAXA) fragile site at Xq27.3. Although FRAXA and FRAXE are indistinguishable by means of conventional cytogenetics, they can now be delineated at the molecular level and provides the basis for a proper diagnosis. The screening for CGG amplifications in the FMR1 gene was based on standard protocols using EcoRI digests on Southern blots and hybridization with the StB12.3 probe. The FRAXE mutation was analyzed by digestion with HindIII and the filters were probed with OxE20. We present the results of 144 patients referred for fragile X testing but negative for the FMR1 gene trinucleotide expansion, that were also screened for the FMR2 expansion. For FRAXE mutation a molecular protocol for OxE18 probe was used, in the DNA samples digested with EcoRI on the same blots as those used for detection of FRAXA. None of the patients tested were positive for the FRAXE expansion. This technique was successfully established into our laboratory routine showing the practical use of testing for FRAXA and FRAXE in a large series of patients.


Asunto(s)
Sondas de ADN/genética , Síndrome del Cromosoma X Frágil/genética , Discapacidad Intelectual/genética , Proteínas Nucleares , Proteínas de Unión al ARN , Transactivadores , Southern Blotting , Brasil , Desoxirribonucleasa EcoRI , Desoxirribonucleasa HindIII , Femenino , Proteína de la Discapacidad Intelectual del Síndrome del Cromosoma X Frágil , Síndrome del Cromosoma X Frágil/diagnóstico , Pruebas Genéticas , Humanos , Masculino , Mutación , Proteínas del Tejido Nervioso/genética , Proteínas/genética , Repeticiones de Trinucleótidos
16.
Int J Mol Med ; 10(2): 231-3, 2002 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12119565

RESUMEN

Fragile X syndrome is the most common form of inherited mental retardation in men. The molecular mechanism underlying the disease is an amplification of a polymorphic trinucleotide repeat (CGG)n located at 5' end of FMR1 which promotes transcriptional silencing of the gene. Four different classes of alleles could be distinguished in the population based on the size of the repeat, however only large amplifications over 200 CGG are associated with the disease. In the past decade several authors have associated premutated alleles, which harbor expansions from 61 to 200 repeats, with the occurrence of premature ovarian failure (POF). In this work we describe a large Brazilian family in which a POF/premutated woman has transmitted to five out of seven daughters a FMR1 premutated allele. From these five women with premutations, three have experienced premature ovarian failure. Our data clearly indicate a co-segregation pattern of inheritance between POF and fragile X premutation.


Asunto(s)
Segregación Cromosómica , Cromosomas Humanos X/genética , Proteínas del Tejido Nervioso/genética , Insuficiencia Ovárica Primaria/genética , Proteínas de Unión al ARN , Adulto , Alelos , Brasil , Femenino , Proteína de la Discapacidad Intelectual del Síndrome del Cromosoma X Frágil , Silenciador del Gen , Humanos , Masculino , Linaje , Repeticiones de Trinucleótidos
17.
Genet Test ; 4(3): 283-7, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11142760

RESUMEN

Individuals with mental disabilities are a heterogeneous group, mainly when we consider the etiology of mental retardation (MR). Recent advances in molecular genetics techniques have enabled us to unveil more about the molecular basis of several genetic syndromes associated with MR. In this study, we surveyed 85 institutionalized individuals with severe MR, 38 males and 47 females, by two molecular techniques, to detect CGG amplifications in the FMR1 gene. No FRAXA mutations were found in the FMR1 gene, reinforcing the low prevalence of Fragile X syndrome among institutionalized individuals with severe MR. We considered the PCR protocol used adequate for screening males with mental retardation of unknown etiology. The use of the Southern blot is still necessary for the decisive diagnosis of the Fragile X syndrome. To exclude chromosomal abnormalities associated with MR as a possible cause of the phenotype in these individuals, G-banded chromosome analysis was performed in all patients and 7.3% of chromosomal aberrations were found. Our results are similar to those reported previously and point to the necessity of expanding the molecular investigation toward other causes of MR, such as subtle chromosomal rearrangements, as suggested recent by a combination of fluorescence in situ hybridization (FISH) and PCR studies.


Asunto(s)
Síndrome del Cromosoma X Frágil/diagnóstico , Pruebas Genéticas , Discapacidad Intelectual/genética , Adolescente , Adulto , Anciano , Brasil/epidemiología , Niño , Preescolar , Análisis Citogenético , Femenino , Síndrome del Cromosoma X Frágil/epidemiología , Síndrome del Cromosoma X Frágil/genética , Humanos , Incidencia , Lactante , Institucionalización , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa
18.
Arq Neuropsiquiatr ; 59(1): 83-8, 2001 Mar.
Artículo en Francés | MEDLINE | ID: mdl-11299437

RESUMEN

The fragile X syndrome (FRAXA) is the most common cause of inherited mental retardation. However, it has been frequently underdiagnosed in pediatric population. The characterization of the most significant pre and post-puberal clinical features observed among patients that are positive for the FMR-1 mutation, is useful as a screening tool for ordering the DNA test. Therefore, a screening program for FRAXA has been conducted in a sample of 104 mentally retarded individuals (92 males and 12 females), comprehending familial history and physical examination in order to determine the clinical characteristics. The molecular test for the disease was performed in all individuals. Seventeen patients (14 males) were positive for the FMR-1 mutation. Familial mental retardation and poor eye contact were the most common clinical findings with statistical significance (p<0.05) in FRAXA pre and post-puberal patients. The post-puberal patients presented, as opposed to the control group, large ears, broad forehead and macroorchidism.


Asunto(s)
Síndrome del Cromosoma X Frágil/genética , Discapacidad Intelectual/genética , Adolescente , Adulto , Estudios de Casos y Controles , Niño , Preescolar , Femenino , Síndrome del Cromosoma X Frágil/diagnóstico , Humanos , Masculino , Mutación , Linaje
19.
Curr Mol Med ; 10(8): 692-704, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20937025

RESUMEN

MicroRNAS (miRNAs) are a class of endogenously single-stranded non-coding RNA molecules that can negatively modulate the expression of target messenger RNAs by 3' UTR base pairing. During the processing of a miRNA, a network of orchestrated molecular events provides a dynamic manner to posttranscriptionally modulate gene expression. Recent research has demonstrated that although these molecules are small, they are involved in several crucial biological functions, as well as, in a broad spectrum of human diseases. In this review, we highlighted the current knowledge on the miRNA pathway field, focusing on how the disruption of the miRNA-mediated silencing pathways could lead to the pathogenesis of neurological disorders. The potential use of miRNAs as diagnostic/prognostic markers and the possibility of reversing the effects of some miRNA polymorphisms/mutations by promising therapeutics procedures have brought new perspectives into the treatment of human pathologies.


Asunto(s)
MicroARNs/genética , Enfermedades del Sistema Nervioso/genética , Regiones no Traducidas 3' , Silenciador del Gen , Marcadores Genéticos/genética , Humanos , MicroARNs/metabolismo
20.
Dis Markers ; 26(4): 155-61, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19729796

RESUMEN

Recent evidence shows that almost 92% of the DS children are born from young mothers, suggesting that other risk factors than advanced maternal age must be involved. In this context, some studies demonstrated a possible link between DS and maternal polymorphisms in genes involved in folate metabolism. These polymorphisms, as well as low intake of folate could generate genomic instability, DNA hypomethylation and abnormal segregation, leading to trisomy 21. We compared the frequency of CBS 844ins68, MTR 2756A>G, RFC-1 80G> A and TC 776C>G polymorphisms among 114 case mothers and 110 matched controls, in order to observe whether these variants act as risk factors for DS. The genotype distributions revealed that there were not significant differences between both samples. However, when we proceed the multiplicative interaction analyses between the four polymorphisms described above together with the previously studied MTHFR 677C>T, MTHFR 1298A>C and MTRR 66A>G polymorphisms, our results show that the combined genotype TC 776CC / MTHFR 677TT and TC 776CC / MTR 2756AG were significantly higher in the control sample. Nevertheless, there was no significant association after Bonferroni correction. Our results suggest that maternal folate-related polymorphisms studied here have no influence on trisomy 21 susceptibility in subjects of Brazilian population.


Asunto(s)
5-Metiltetrahidrofolato-Homocisteína S-Metiltransferasa/genética , Cistationina betasintasa/genética , Síndrome de Down/genética , Proteínas de Transporte de Membrana/genética , Polimorfismo Genético , Transcobalaminas/genética , Adolescente , Adulto , Brasil/epidemiología , Niño , ADN/genética , Síndrome de Down/epidemiología , Síndrome de Down/metabolismo , Femenino , Predisposición Genética a la Enfermedad , Humanos , Madres , Factores de Riesgo
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