Autogenic feeder free system from differentiated mesenchymal progenitor cells, maintains pluripotency of the MEL-1 human embryonic stem cells.

Human embryonic stem cells (hESc) are known for its pluripotency and self renewal capability, thus possess great potential in regenerative medicine. However, the lack of suitable xenofree extracellular matrix substrate inhibits further applications or the use of hESc in cell-based therapy. In this study, we described a new differentiation method, which generates a homogeneous population of mesenchymal progenitor cells (hESc-MPC) from hESc via epithelial-mesenchymal transition. The extracellular matrix (ECM) proteins from hESc-MPC had in turn supported the undifferentiated expansion of hESc. Immunocytochemistry and flow cytometry characterization of hESc-MPC revealed the presence of early mesenchymal markers. Tandem mass spectometry analysis of ECM produced by hESc-MPC revealed the presence of a mixture of extracellular proteins which includes tenascin C, fibronectin, and vitronectin. The pluripotency of hESc (MEL-1) cultured on the ECM was maintained as shown by the expression of pluripotent genes (FoxD3, Oct-4, Tdgf1, Sox-2, Nanog, hTERT, Rex1), protein markers (SSEA-3, SSEA-4, TRA-1-81, TRA-1-60, Oct-4) and the ability to differentiate into cells representative of ectoderm, endoderm and mesoderm. In summary, we have established a xeno-free autogenic feeder free system to support undifferentiated expansion of hESc, which could be of clinical relevance.

Bone marrow necrosis preceding infantile acute lymphoblastic leukaemia.

We report a case of bone marrow necrosis preceding infantile acute lymphoblastic leukaemia (ALL). Bone marrow necrosis is a rare antemortem event and has been known to be present in many conditions, notably in haematological malignancies like acute lymphoblastic leukaemia. This case was a 6-month-old Chinese boy who was referred to Hospital Universiti Kebangsaan Malaysia for further investigation of pancytopaenia, high-grade fever, bloody diarrhoea and petechial rashes for one week. His first bone marrow aspirate revealed bone marrow necrosis. His clinical condition improved after ten days. However, his full blood picture then revealed the presence of 5% blast cells. His subsequent marrow 2 weeks later revealed acute lymphoblastic leukaemia (FAB-L1) and immunophenotyping showed precursor B acute lymphoblastic leukaemia-null type. He was started on United Kingdom Acute Lymphoblastic leukaemia (UK ALL) Infantile Leukaemia protocol, however, he defaulted treatment after 3 days. Mode of presentation, mechanism of disease and laboratory investigations and outline of treatment will be discussed.

Complete molecular characterisation of glucose-6-phosphate dehydrogenase (G6PD) deficiency in a group of Malaysian Chinese neonates.

We performed DNA analysis on cord blood samples of 128 Chinese male neonates diagnosed as G6PD deficiency in Hospital Universiti Kebangsaan Malaysia by a combination PCR-restriction enzyme digest technique, Single Stranded Conformation Polymorphism analysis and DNA sequencing. We found 10 different G6PD-deficient mutations exist. The two commonest alleles were G6PD Canton 1376 G>T (42.3%) and Kaiping 1388 G>A (39.4%) followed by G6PD Gaohe 592 G>A (7.0%), Chinese-5 1024 C>T, Nankang 517 T>C (1.5%), Mahidol 487 G>A (1.6%), Chatham 1003 G>T (0.8%), Union 1360 C>T (0.8%), Viangchan 871 G>A (0.8%) and Quing Yang 392 G>T (0.8%). Sixty eight percent (88/125) neonates in this study had neonatal jaundice and 29.7% developed hyperbilirubinemia >250 micromol/l. The incidence of hyperbilirubinemia >250 micromol/l was higher in G6PD Kaiping (43.8%) than G6PD Canton (22%) (p< 0.05). There was no significant difference in the incidence of neonatal jaundice, mean serum bilirubin, mean age for peak serum bilirubin, percentage of babies requiring phototherapy and mean duration of phototherapy between the two major variants. None of the 88 neonates required exchange transfusion. In conclusion we have completely characterized the molecular defects of a group of Chinese G6PD deficiency in Malaysia. The mutation distribution reflects the original genetic pool and limited ethnic admixture with indigenous Malays.