Stability of HIV-1 RNA in blodd during specimen handling and storage prior to amplification by NASBA-QT

The influence of different storage temperatures and anticoagulation conditions on the HIV-1 RNA load as measured by NASBA-QT was examined. Blood specimens from 14 HIV-1 infected individuals were processed within 2 h after collection. The HIV-1 RNA load remained stable for at least 6 months when samples were frozen directly at -70 degrees C in lysis buffer. This lysis buffer fully inactivated the virus. When whole EDTA blood was stored, the HIV-1 RNA load was stable for 72 h at 25 degrees C, but it declined within 24 h at 4 degrees C. The HIV-1 RNA load in whole heparinized blood declined significantly after 24 h at both 4 and 25 degrees C. It was slightly lower (average of 0.18 log ml-1) than in whole EDTA blood. At 4 degrees C, the HIV-RNA load in serum and EDTA-plasma stored with lysis buffer did not decline up to 14 days. At + 30 degrees C, however, the load declined significantly after 2 days. Of clinical significance, the mean load in EDTA plasma was 0.5 log ml-1 higher than in serum. This difference was patient dependent (range 0.1-0.7 log ml-1). We thus recommend, for quantifying HIV-1 RNA by NASBA, to use preferably EDTA blood which is kept at room temperature until plasma separation. When using heparinized blood, the plasma should be stored frozen within 8

Stability OF HIV-1 RNA in blood during specimen handling and storage prior to amplification by NASBA-QT

The influence of different storage temperatures and anticoagulation conditions on the HIV-1 RNA load as measured by NASBA-QT was examined. Blood specimens from 14 HIV-1 infected individuals were processed within 2 h after collection. The HIV-1 RNA load remained stable for at least 6 months when samples were frozen directly at -70 degrees C in lysis buffer. This lysis buffer fully inactivated the virus. When whole EDTA blood was stored, the HIV-1 RNA load was stable for 72 h at 25 degrees C, but it declined within 24 h at 4 degrees C. The HIV-1 RNA load in whole heparinized blood declined significantly after 24 h at both 4 and 25 degrees C. It was slightly lower (average of 0.18 log ml-1) than in whole EDTA blood. At 4 degrees C, the HIV-RNA load in serum and EDTA-plasma stored with lysis buffer did not decline up to 14 days. At + 30 degrees C, however, the load declined significantly after 2 days. Of clinical significance, the mean load in EDTA plasma was 0.5 log ml-1 higher than in serum. This difference was patient dependent (range 0.1-0.7 log ml-1). We thus recommend, for quantifying HIV-1 RNA by NASBA, to use preferably EDTA blood which is kept at room temperature until plasma separation. When using heparinized blood, the plasma should be stored frozen within 8

Ex vivo expansion and pluripotential differentiation of cryopreserved human bone marrow mesenchymal stem cells

This study is aimed at investigating the potentials of ex vivo expansion and pluri-differentiation of cryopreservation of adult human bone marrow mesenchymal stem cells (hMSCs) into chondrocytes, adipocytes and neurocytes. Cryopreserved hMSCs were resuscitated and cultured for 15 passages, and then induced into chondrocytes, adipocytes and neurocytes with corresponding induction medium. The induced cells were observed for morphological properties and detected for expressions of type II collagen, triglyceride or neuron-specific enolase and nestin. The result showed that the resuscitated cells could differentiate into chondrocytes after exposure to transforming growth factor β(1) (TGF-β(1)), insulin-like growth factor I (IGF-I) and vitamin C (V(C)), and uniformly changed morphologically from a spindle-like fibroblastic appearance to a polygonal shape in three weeks. The induced cells were heterochromatic to safranin O and expressed cartilage matrix-procollagenal (II) mRNA. The resuscitated cells cultured in induction medium consisting of dexamethasone, 3-isobutyl-1-methylxanthine, indomethacin and IGF-I showed adipogenesis, and lipid vacuoles accumulation was detectable after 21 d. The resuscitated hMSCs were also induced into neurocytes and expressed nestin and neuron specific endolase (NSE) that were special surface markers associated with neural cells at different stage. This study suggested that the resuscitated hMSCs should be still a population of pluripotential cells and that it could be used for establishing an abundant hMSC reservoir for further experiment and treatment of various clinical diseases