Umbilical cord blood: Current status & promise for the future.

Umbilical cord blood (UCB) has been shown to be a suitable source of haematopoietic stem cells (HSCs) for haematopoietic reconstitution. An increase in the number of UCB transplants indicates an expansion of utility in a broad spectrum of disease conditions. Along with the advantages, UCB also has limitations, and hence several investigators are working to further optimize UCB for this use. Beyond haematopoietic transplantation, additional potential applications of UCB include immunotherapy, tissue engineering and regenerative medicine. UCB banking has improved with time largely due to involvement of professional organizations and their published standards. However, accreditation of these organizations remains voluntary, and in India three of ten banks are public with the remaining being private. Only one public and one private bank are American Association of Blood Banks (AABB) accredited in India. Government agencies need to provide regulatory and safety oversight, which is lacking in serveral countries. Public policy regarding UCB is in its infancy throughout most of the world. Ethical issues, including access to UCB banking and use as therapy for diseases other than haematological and metabolic disorders are in the early phase of trials and remain speculative.

Effect of human cord blood-derived stem cells on induced diabetic retinopathy in adult albino rat: histological and immunohistochemical study

Diabetic retinopathy is a leading cause of blindness in adults. Recent developments in stem cell field have widened the prospects of applying cell-based therapies to regenerate ocular tissues. This study was done to explore the potential effect of human cord blood-derived stem cells on induced diabetic retinopathy in adult albino rats. This study was performed on 26 adult male albino rats. Animals were randomly divided into four groups. Group I [control group]: five control animals each received single intraperitoneal injection of citrate buffer. Group II: seven animals in whom diabetes was induced by single intraperitoneal injection of streptolotocin and animals were killed 4 weeks later. Group III: seven animals in whom diabetes was induced the same way as in group II and animals were killed 8 weeks later. Group IV: seven animals with diabetes were injected with ferrous oxide-labeled cord blood-derived stem cells 4 weeks after induction of diabetes and were killed 4 weeks after stem cell injection, All sections from retina of all groups were subjected to Haematoxylin and eosin, Prussian blue staining and CD34 immunohistochemistry. Statistical analysis was done to measure the mean number of ganglion cell nuclei and the wide clear areas around them. Groups II and III showed progressive histological changes of diabetic retinopathy. Group IV exhibited a significant increase in the number of ganglion cells with less clear areas compared with group III. Moreover, cells positive for Prussian blue and CD34 were detected in different retinal layers of group IV. Human cord blood-derived stem cells injected into rats with diabetic retinopathy contributed to restoration of ganglion cell layer and vascular repair, which may postulate a potential therapeutic intervention for diabetic retinopathy

Second allogeneic peripheral blood stem cell transplants with reduced-intensity conditioning / Segundos trasplantes hematopoyéticos con esquemas de acondicionamiento de intensidad reducida

In two institutions in México, twelve patients were given a second allogeneic stem cell transplantation, using the "Mexican" non-myeloablative preparative regimen. Eight had a malignant condition (six acute leukemias, one myelofibrosis and one myelodysplasia), eleven individuals were allografted twice from the same donor and in one case, cells from two different umbilical cords were used. The median time to conduct the second allograft after the first one was 6 months (range 1-41). The five patients who failed to engraft after the first transplant failed also to engraft after the second one; all of them had been heavily transfused. Only three patients were successfully rescued with the second transplant, two with acute leukemia and one with aplastic anemia. Seven patients are alive 10-41 months (median 35) after the second transplant, but only three (25%) remain disease-free. The 52-month overall survival (SV) of the patients is 58%, whereas the median overall SV has not been reached, being above 52 months. Conducting a second allograft may be useful to rescue some individuals relapsing after a first hematopoietic allotransplant.

En dos instituciones en México se llevaron a cabo doce segundos trasplantes de células hematopoyéticas usando el "método mexicano" de acondicionamiento no mieloablativo. Ocho pacientes tenían una enfermedad maligna (seis leucemias agudas, una mielofibrosis y una mielodisplasia). Once sujetos se retrasplantaron del mismo donador y en un caso se emplearon células hematopoyéticas de dos diferentes cordones umbilicales. La mediana del tiempo transcurrido entre los dos trasplantes fue de seis meses (rango 1 a 41). Los cinco pacientes que no se injertaron con el primer trasplante tampoco se injertaron con el segundo; todos ellos habían sido multitransfundidos antes de los trasplantes. Sólo tres pacientes se pudieron rescatar con el segundo trasplante, dos con leucemia aguda y uno con anemia aplástica. Siete pacientes están vivos 10 a 41 meses (mediana 35) después del segundo trasplante, pero sólo tres (25%) se encuentran libres de enfermedad. La supervivencia (SV) global a 52 meses es de 58%, en tanto que la mediana de SV no se ha alcanzado y es mayor de 52 meses. Hacer un segundo trasplante hematopoyético puede rescatar a algunos pacientes quienes recaen después de un trasplante de médula ósea.