1,721,242 research outputs found
Therapy with interferons in blood diseases
No full textWe report the clinical experience gained with interferon treatment of B and T cell neoplasms, as well as of myeloproliferative and myelodysplastic syndrome
Mesenchymal Stem cells Transplantation for neurodegenerative diseases.
No full textNeurodegenerative diseases are characterized by a progressive degeneration of selective neural populations. The lack of effective treatment and the characteristic of their pathology make these diseases appropriate candidates for cell therapy. Mesenchymal stem cells (MSCs) are multipotent stem-like cells that are capable of differentiating into mesenchymal and nonmesenchymal lineages. Their regenerative capacity after in vivo transplantation into animal models of neurodegenerative diseases has suggested that they could be useful against human diseases. Human bone marrow-derived MSCs (hMSCs) can be easily amplified in vitro and their transdifferentiation has been claimed in vitro and in vivo in neural cells. There are some doubts concerning the exact mechanisms responsible for the beneficial outcome observed after MSC transplantation into neurodegenerating tissues. Possible interpretations include cell replacement, trophic factor delivery, and immunomodulation. This review mainly concerns hMSCs transplantation in neurodegenerative diseases, because it has proven to be feasible, safe, and potentially effective. Although they have been used in hundreds of clinical trials, mixed results and no functional and long-lasting integration have so far been observed. hMSCs transplantations therefore still have their "dark side." However, the challenge in well-planned clinical trials merits discussion
Human leukemic intermediate DNA components
No full textThe DNA extracted from human leukemic leucocytes has been fractionated on a methylated albumin kieselguhr (MAK) column. The different fractions obtained have been reannealed to a Cot value of 20 mol times sec/1 to study the distribution of the intermediate DNA on the MAK column. Intermediate DNA contains two components, one (CsCl density after reannealing, 1.703 g/ml) obtained by reannealing high molecular weight DNA, the other (CsCl density after reannealing, 1.707 g/ml) obtained only by reannealing sonicated low molecular weight DNA. High molecular weight intermediate DNA (1.703 component) is eluted early from the MAK column in the fractions corresponding to the main DNA peak, while low molecular weight intermediate DNA (1.707 component) is more widespread on the MAK column, but appears to be enriched in the fractions eluted later. The possibility is discussed that the latter component is interspersed in that part of the genome which is apparently more homogeneous in density in an analytical CsCl gradient, and is absent on the skewed, more heterogeneous, heavy side of the main DNA in CsCl
Repeated sequences in human DNA
No full textHuman DNA has been fractionated in Ag+Cs2SO4 and Hg2+Cs2SO4 preparative density gradients, and the fractions obtained have been centrifuged in neutral CsCl after extensive dialysis to eliminate Hg2+ and Ag2+. By centrifugation in Ag+Cs2SO4 a new satellite, called satellite DNA II, has been isolated from human DNA. It has a density of 1.693 g/ml. in neutral CsCl, accounts for 2% of the total approximately, renatures rapidly and separates into complementary strands having different densities in alkaline CsCl. In Hg2+Cs2SO4 gradients human DNA appears to be composed of two classes of molecules. The first, which accounts for approximately 80% of the total, is highly heterogeneous in base composition, its density in CsCl ranging from 1.690 to 1.720 g/ml., and is distributed in Hg2+Cs2SO4 so that the A·T-rich fractions are on the heavy side and the G·C-rich fractions on the light side, as expected on the basis of the preferential binding of Hg2+ to A·T pairs. The second class, which accounts for approximately 15% of the total, is more homogeneous, has a density of 1.696 g/ml., and is located on the light side of the DNA band in the Hg2+Cs2SO4 gradient. This suggests that the amount of Hg2+ bound to this A·T-rich DNA is abnormally low. This second class of DNA has been isolated by preparative CsCl centrifugation from a pool of the light fractions obtained from DNA-Hg2+Cs2SO4 centrifugation. It tends to renature after heat-denaturation, as shown by the shift of its density towards the native value in neutral CsCl
Restriction enzyme analysis of human leukemic mitochondrial DNA
No full textMitochondrial DNA from both normal human tissue and leukemic human leukocytes (AML and CML) were analyzed by restriction-enzyme digestion, polyacrylamide gradient gel electrophoresis and ethidium bromide staining. Both normal and leukemic human mitochondrial DNA show molecular heterogeneity from individual to individual. This intraspecies variability is significantly higher in leukemias, where most of the cases show unique patterns. We suggest that this variability might be a molecular symptom of mutagenesis
Different satellite deoxyribonucleic acids of guinea pig and ox
No full textBy Ag+-Cs2SO4 preparative centrifugation two new satellite DNAs, called satellite DNAs II and III, are isolated from guinea pig DNA, besides satellite DNA I which was previously isolated. Guinea pig satellite DNAs II and III have the same density of 1.704 g/cm3 in caesium chloride: they each account for approximately 2.5% of the total DNA and appear as distinct bands on the light side of the Ag+-Cs2SO4 gradient. Their complementary strands differ in density one from the other in alkaline caesium chloride, respectively, by 0.031 and 0.022 g per cm3. They also differ in density in neutral caesium chloride. The two satellite DNAs previously isolated from calf thymus can be separated into their complementary strands. The two strands of calf thymus satellite DNA I (d 1.713 g/cm3) differ in density in alkaline caesium chloride by 0.019 g/cm3: those of calf thymus satellite DNA II differ by only 0.005 g/cm3. The kinetics of renaturation of the three guinea pig satellite DNAs and of calf thymus satellite DNA I were studied by determining the optical reassociation curves. On the basis of these results the repeated unit of guinea pig satellite DNA I would appear to be considerably longer than those of the other satellite DNAs
Renaturation properties and localization in heterochromatin of human satellite DNA's
No full textHuman DNA has been fractionated by centrifugation in an Ag+-Cs2SO4 preparative density gradient. Besides satellite DNA I and II, previously demonstrated and characterized, a newly identified satellite DNA III has been isolated, having a CsCl density of 1.696 g/ml and accounting for 1.5 % of the total genome. The renaturation properties of human satellite DNA III, estimated by determining its CsCl densities and melting curves after denaturation and renaturation, indicate that it is fast renaturing and therefore highly repeated, as are the other human satellite DNAs. The nuclei obtained from human placenta and leukemic leucocytes have been fractionated into heterochromatin and euchromatin. Satellite DNAs are enriched in heterochromatin, while they are no longer detectable in the DNA extracted from euchromatin, centrifuged in Ag+-Cs2SO4
- …
