RESUMO
Reduced bone mineral density (BMD) in childhood is a risk factor for osteoporosis in later life. This case-control study determined the prevalence of low BMD, calcium intake and physical activity in 62 haemophilic children and 62 sex-, race- and age-matched healthy boys as controls. Lumbar spine (L2-L4) BMD was determined by dual-energy X-ray absorptiometry; BMD was considered to be low when Z-score > or =2. Physical activity was assessed using a validated questionnaire and calcium intake with a standardized quantitative food frequency questionnaire. Twenty-four patients (38%) had low BMD, whereas this was found in only 10 (16%) controls [odds ratio (OR) 2.86, 95% confidence interval (CI) 1.17-7.41; P = 0.014]. Lumbar BMD was significantly lower in the haemophilia patients than the controls (-1.6 +/- 1.0 vs. -0.9 +/- 0.9 respectively; P = 0.0004). Sedentary and low-grade exercise predominated in haemophilia (77%) versus control (50%) (OR 3.2, 95% CI 1.36-7.79; P = 0.003). There were no differences between groups with regard to calcium intake. Our results suggest that low-physical activity is a risk factor for reduced lumbar bone mass in the haemophilic group. This factor must be monitored to avoid a significant reduction in BMD that might contribute to further skeletal fragility.
Assuntos
Densidade Óssea , Hemofilia A/fisiopatologia , Atividade Motora , Absorciometria de Fóton/métodos , Adolescente , Antropometria/métodos , Cálcio da Dieta/administração & dosagem , Estudos de Casos e Controles , Criança , Humanos , Vértebras Lombares/fisiologia , Masculino , Osteoporose/etiologia , Fatores de RiscoRESUMO
Hemophilia A (HA) is one of the most common inherited bleeding disorders caused by FVIII gene mutations. Inversion of intron 22 (inv22) originates 50% of cases of severe HA and is a major risk factor for inhibitor development. Inversion of intron 1 (inv1) has been reported to occur in 2-3% of severe HA patients. We studied both inversions to determine their frequencies in Mexican patients with severe HA and to compare these data with other HA populations. The inv22 was evaluated as a risk factor for FVIII inhibitor development in severe HA patients. We studied 44 patients from 31 severe HA families for the detection of inv22 and 94 patients from 65 families to detect inv1. We used the subcycling long-distance PCR to detect inv22 and rapid PCR in duplex reactions to detect inv1. We found a frequency of 45% for the inv22 and no inv1-positive patients (0%). These frequencies were not statistically different from other populations, although haplotype analyses of FVIII gene and telomeric regions should be incorporated to explore population-specific variation of inv1 frequencies. Inv22-positive patients showed 1.88X higher risk for developing inhibitors with respect to patients carrying other severe mutations; however, this OR value was not significant. Our findings confirm inv22 as a hot-spot for severe HA and evidence the low frequency of inv1 in a Mexican population. The non-significant risk for developing inhibitors among inv22-positive patients agrees with the variety of genetic and non-genetic factors involved in such a complication.
Assuntos
Inversão Cromossômica/genética , Fator VIII/genética , Hemofilia A/genética , Íntrons/genética , Isoanticorpos/efeitos adversos , Inversão Cromossômica/estatística & dados numéricos , Estudos de Coortes , Estudos Transversais , Fator VIII/imunologia , Frequência do Gene , Hemofilia A/terapia , Humanos , Isoanticorpos/imunologia , México , Razão de ChancesRESUMO
RT-PCR studies in 93 patients with chronic myelogenous leukemia from the Mexican West were done in order to know the proportion of b2a2 and b3a2 BCR/ABL1 transcripts. Forty-five patients showed the b3a2 transcript (48%), 37 (40%) displayed the b2a2 and in 11 cases (12%) both transcripts were detected. Statistical analyses showed that these figures are in accordance with two of three similar studies realized in Mexican population. Moreover, significant differences were found among Mexican people and patients from other countries, namely Ecuador, England, Italy, Poland, Japan, and Thailand. Ecuadorian patients showed differences with all the populations analyzed. These variations could be due to a different genetic background.
Assuntos
Proteínas de Fusão bcr-abl/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Proteínas de Fusão bcr-abl/análise , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Transcrição GênicaRESUMO
Recurring chromosome translocations, which are found in leukemia, can result in the inappropriate expression of oncogenes or in the formation of chimeric genes that code for structurally and functionally abnormal proteins. The chromosomal t(1;9)(q23.3 approximately q25;q34) was found in a patient with biphenotypic leukemia. Fluorescence in situ hybridization (FISH) analysis revealed that the break on chromosome 9 occurred in the ABL1 gene. The breakpoint on chromosome 1 occurred distal to the PBX1 gene at 1q23.3, as shown by FISH using BAC RP11-503N16 and RP11-403P14, which flank the PBX1 locus; hence, the ABL1 gene can be fused with another gene distal to PBX1 gene.
Assuntos
Cromossomos Humanos Par 1/genética , Cromossomos Humanos Par 9/genética , Leucemia/genética , Proteínas Proto-Oncogênicas c-abl/genética , Translocação Genética , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quebra Cromossômica , Rearranjo Gênico , Humanos , Hibridização in Situ Fluorescente , Leucemia/tratamento farmacológico , Leucemia/patologia , Masculino , Fenótipo , Sensibilidade e EspecificidadeRESUMO
Introducción. La hemosiderosis pulmonar idiopática (HPI) es un padecimiento poco frecuente, se presenta más en el niño que en el adulto. Se ha reportado que la combinación de prednisona y un inmunosupresor modifican la evolución clínica. En este trabajo se presenta una serie de 10 pacientes con HPI que fueron tratados con prednisona y azatioprina.Material y métodos. Se describe la evolución clínica de 10 casos con HPI con edades comprendidas entre 1 y 9 años. Después de controlar clínicamente el sangrado pulmonar en su fase aguda se les administró prednisona y azatioprina de forma continua por un período mínimo de 3 años.Resultados. Con el tratamiento, 3 pacientes desde el inicio no volvieron a presentar sangrado pulmonar, sólo 1 paciente requirió de transfusión sanguínea y ningún paciente se hospitalizó. Una paciente falleció 1 año después de terminar con su tratamiento. En mayo de 1999 se evaluaron 8 pacientes que terminaron el tratamiento, se encontró la función respiratoria anormal en todos; en 2 había secuelas clínicas y ninguno presentaba alteraciones radiológicas.Conclusiones. La prednisona y la azatioprina provieron de una mejoría clínica inmediata. Después de suspender el tratamiento todos presentaron función respiratoria alterada en un grado no significativo.
Assuntos
Humanos , Masculino , Feminino , Lactente , Pré-Escolar , Hemossiderose , Pneumopatias , Azatioprina , PrednisonaRESUMO
Se presenta el caso de un niño de siete años de edad con hemofilia clásica severa quien presentó epistaxis bilateral profusa y sangrado en herida de venodiseccación que no respondió a la transfusión de crioprecipitados en dosis crecientes hasta de 100U/kg cada 6 horas. Debido a que la determinacación de los niveles de inhibidores del factor VIII mostró valor de 6.75 U Bethesda/ml, se practicaron dos exsanguinotransfusiones, lo que permitió controlar el sangrado. Se concluye que la exsanguinotransfusión es un procedimiento útil para reducir transitoriamente los niveles de anticuerpos circulantes contra el factor VIII en niños hemofílicos con esta complicación y en quienes es imperativo controlar las manifestaciones de sangrado
Assuntos
Criança , Humanos , Masculino , Transfusão Total , Fator VIII/antagonistas & inibidores , Hemofilia A/terapiaRESUMO
Se estudiaron ocho pacientes con anemia de Fanconi, con edades entre cinco a 12 años; seis fueron del sexo masculino. Todos los pacientes presentaron anemia de grado variable, leucopenia, plaquetopenia y reticulocitopenia. La médula ósea se observó hipocelular con incremento en el contenido de grasa y aumento relativo en la proporción de células plasmáticas y reticulares. Tres pacientes presentaron retraso mental. Siete niños presentaron malformaciones esqueléticas, dos malformaciones renales y tres otras malformaciones. El estudio del cariotipo fue normal en cuatro pacientes y en uno se observaron tres fracturas cromosómicas. La hemoglobina fetal estuvo elevada en todos los casos. Todos los niños fueron tratados con oximetolona en dosis promedio de 2 mg/kg/dia por períodos entre siete meses a siete años. Cinco pacientes fallecieron por complicaciones hemorrágicas. Los tres pacientes restantes mantienen niveles aceptables de hemoglobina, cuenta de neutrófilos absolutos y plaquetas