RESUMEN
Coagulation factor XIII (FXIII) exists as heterotetramer (FXIII-A2B2) in the plasma and as dimer (FXIII-A2) in cells. Activated FXIII mechanically stabilizes fibrin and protects it from fibrinolysis by cross-linking fibrin chains and α2-plasmin inhibitor to fibrin. FXIII is essential to maintaining haemostasis, and its deficiency causes severe bleeding diathesis. Due to improper laboratory practices, FXIII deficiency is considered the most under-diagnosed bleeding disorder. The aim of this study was to demonstrate in two cases how FXIII deficiency is properly diagnosed and classified, and to compare results of laboratory analysis and clinical symptoms. FXIII activity from plasma and platelets was measured by a modified ammonia release assay, while FXIII-A2B2, FXIII-A and FXIII-B antigens were determined by ELISA. The exon-intron boundaries and the promoter region of F13A1 gene were amplified by PCR and the amplified products were analysed by direct fluorescent sequencing. FXIII-A mRNA in platelets was determined by RT-qPCR. Two children with severe bleeding symptoms were investigated. In both cases FXIII activity and FXIII-A antigen were undetectable in the plasma and platelet lysate. In the plasma no FXIII-A2B2 antigen was found, while FXIII-B antigen was >30% in both cases. Proband1 was a compound heterozygote possessing a known missense mutation (c.980G>A, p.Arg326Gln) and a novel splice-site mutation (c.1112+2T>C). Proband2 was homozygote for a novel single nucleotide deletion (c.212delA) leading to early stop codon. The discovered mutations explain the severity of clinical symptoms and the laboratory data. Methods precise in the low activity/antigen range are required to draw valid conclusion on phenotype-genotype relationship.
Asunto(s)
Deficiencia del Factor XIII/diagnóstico , Deficiencia del Factor XIII/genética , Factor XIII/genética , Fenotipo , Adolescente , Plaquetas/metabolismo , Análisis Mutacional de ADN , Exones , Factor XIII/metabolismo , Deficiencia del Factor XIII/sangre , Factor XIIIa/genética , Factor XIIIa/metabolismo , Femenino , Humanos , Recién Nacido , Masculino , Mutación , LinajeRESUMEN
BACKGROUND: Gastrointestinal stromal tumours (GIST) are characterised by high expression of KIT and ETV1, which cooperate in GIST oncogenesis. Our aim was to identify microRNAs that are deregulated in GIST, have a role in GIST pathogenesis, and could potentially be used as therapeutic tool. METHODS: Differentially expressed microRNAs between primary GIST (n=50) and gastrointestinal leiomyosarcomas (GI-LMS, n=10) were determined using microarrays. Selected microRNA mimics were transfected into GIST-882 and GIST-T1 cell lines to study the effects of microRNA overexpression on GIST cells. Luciferase reporter assays were used to establish regulation of target genes by selected microRNAs. RESULTS: MiR-17-92 and miR-221/222 cluster members were significantly (P<0.01) lower expressed in GIST vs GI-LMS and normal gastrointestinal control tissues. MiR-17/20a/222 overexpression in GIST cell lines severely inhibited cell proliferation, affected cell cycle progression, induced apoptosis and strongly downregulated protein and--to a lesser extent--mRNA levels of their predicted target genes KIT and ETV1. Luciferase reporter assays confirmed direct regulation of KIT and ETV1 by miR-222 and miR-17/20a, respectively. CONCLUSION: MicroRNAs that may have an essential role in GIST pathogenesis were identified, in particular miR-17/20a/222 that target KIT and ETV1. Delivering these microRNAs therapeutically could hold great potential for GIST management, especially in imatinib-resistant disease.
Asunto(s)
Proteínas de Unión al ADN/genética , Tumores del Estroma Gastrointestinal/genética , MicroARNs/genética , Proteínas Proto-Oncogénicas c-kit/genética , Factores de Transcripción/genética , Adulto , Anciano , Anciano de 80 o más Años , Apoptosis/genética , Carcinogénesis/genética , Procesos de Crecimiento Celular/genética , Proteínas de Unión al ADN/metabolismo , Femenino , Tumores del Estroma Gastrointestinal/tratamiento farmacológico , Tumores del Estroma Gastrointestinal/patología , Humanos , Masculino , MicroARNs/metabolismo , Persona de Mediana Edad , Familia de Multigenes , Proteínas Proto-Oncogénicas c-kit/metabolismo , Factores de Transcripción/metabolismo , TransfecciónRESUMEN
During the six months from January-June 1994, 10 cases of severe and 11 of less severe pulmonary infection caused by Pseudomonas aeruginosa were diagnosed in patients with chronic obstructive airways disease. Possible sources were evaluated. P. aeruginosa was isolated from four of the 22 nebulizers tested. The relationship of isolates from the patients and nebulizers was confirmed by sero- and phage-typing, and by arbitrarily-primed polymerase chain reaction (AP-PCR). Three types were identified and the distribution of types in patients with severe infection was as follows (one patient had a multiple infection). Type I was isolated from two nebulizers and from sputa, and/or blood and/or bronchial protected specimen brush samples or bronchial lavage fluid from four patients. Type II came from the sputa of three patients and a third nebulizer; and type III from sputa and/or blood of four further patients and another nebulizer. The data provided evidence for the relation between P. aeruginosa as a cause of infection and the contamination of the nebulizers. When nebulizer mouthpieces were changed every 24 h and sterilized between patients, no more contamination occurred, and the outbreak ceased.