RESUMO
BACKGROUND AND OBJECTIVES: As part of the bone marrow niche, cellular and acellular components like mesenchymal stem cells (MSCs) and extracellular matrix (ECM) proteins influence human haematopoiesis. To identify factors able to improve the in vitro generation of red blood cells (RBCs), we investigated the effect of these factors on proliferation and differentiation of human haematopoietic stem cells (HSCs) into erythroid cells. MATERIAL AND METHODS: Granulocyte colony-stimulating factor-mobilized CD34(+) HSCs were cultured for 16 days using an in vitro erythropoiesis assay as described previously (by our group). The HSCs were co-cultured with MSCs in either direct or indirect contact and with different ECM proteins (fibronectin, laminin, collagen and a mixture of ECM proteins, called ECM gel). RESULTS: Co-culturing of HSCs with ECM gel improved cell viability, and the presence of laminin slightly increased the maturation into enucleated RBCs. HSC expansion could not be improved by addition of any of the ECM proteins investigated. In contrast, fibronectin inhibited erythroid formation. Co-culturing of HSCs with MSCs generally stimulated cell viability and HSC proliferation, however, in favour of the myeloid lineage. In summary, of all investigated factors, only laminin and ECM gel had a supportive effect on RBC development under the described in vitro culture conditions.
Assuntos
Células Eritroides/citologia , Células Eritroides/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Células-Tronco Hematopoéticas/citologia , Laminina/metabolismo , Células-Tronco Mesenquimais/metabolismo , Antígenos CD34/metabolismo , Antígenos CD34/farmacologia , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Fibronectinas/metabolismo , Fibronectinas/farmacologia , Glicoforinas/metabolismo , Glicoforinas/farmacologia , Fator Estimulador de Colônias de Granulócitos/metabolismo , Fator Estimulador de Colônias de Granulócitos/farmacologia , Células-Tronco Hematopoéticas/metabolismo , Humanos , Interleucina-16/metabolismo , Laminina/farmacologiaRESUMO
The investigation of a case of disputed paternity revealed indirect exclusion of the alleged father in the haptoglobin system and in the DNA single-locus system D16S309/Hinf I (MS205). The paternity index for the non-exclusion systems was > 10(6). Since both exclusion systems (HP and MS205) are located on chromosome 16, we investigated 10 microsatellite loci covering this chromosome with 10-20 cM resolution. Analysis of the child's chromosome showed only alleles of maternal origin and lack of inheritance of paternal alleles for five informative loci. The markers close to the centromere of chromosome 16 were heterozygous, whereas distal loci were either heterozygous or homozygous for maternal alleles. This is consistent with a maternal meiosis I nondisjunction of chromosome 16 leading to maternal uniparental heterodisomy. This case emphasizes that the opinion of non-paternity should be based on the absence of paternal alleles at genetic systems located on at least two different chromosomes.
Assuntos
Aberrações Cromossômicas , Cromossomos Humanos 16-18 , Paternidade , Alelos , Criança , Feminino , Haptoglobinas/genética , Humanos , Masculino , Repetições de Microssatélites , Não Disjunção Genética , Reação em Cadeia da PolimeraseRESUMO
Heparin-induced thrombocytopenia type II (HIT II) is the most severe complication during prophylactic treatment with low doses of heparin. Five cases demonstrate the life-threatening consequences of this immune-mediated thromboembolic disease. In order to improve prognosis it is most important to start therapy just before diagnosis is assured by laboratory tests. First choice treatment is the low-molecular-weight heparinoid Orgaran. In patients with an episode of HIT II both low-molecular-weight heparin and unfractionated heparin will be contraindicated for a life time.
