New trends in umbilical cord blood transplantation

Functional beta-cells derived from umbilical cord blood mesenchymal stem cells for curing rats with streptozotocin-induced diabetes mellitus

INTRODUCTION

This study aimed to investigate the therapeutic response to injected human umbilical cord blood mesenchymal stem cells (UCBMSCs) among albino rats with streptozotocin (STZ)-induced diabetes mellitus.

METHODS

Control group (GI; n = 25) rats were fed with standard rat diet. Rats with STZ-induced diabetes mellitus without (GII; n = 25) and with (GIII; n = 25) differentiated human UCBMSCs implantation were the test groups. Rats were sacrificed in Week 11 following implantation. Liver biopsies were sectioned and stained in order to highlight both the presence and function of impregnated cells in the liver tissue.

RESULTS

Haematoxylin and eosin-stained sections in GI and GII rats showed normal liver architecture while GIII rats showed presence of cell clusters inside the liver tissue and around the central veins. Cell clusters with blue cytoplasm were present in sections in GIII rats but absent in GI and GII rats, indicating the presence of injected differentiated human UCBMSCs. The anti-human insulin immunostaining of GIII rats showed clusters of cells within the liver parenchyma and around central veins, indicating that these cells were active and secreting insulin.

CONCLUSION

UCBMSCs are proficient in differentiating into insulin-producing cells in vivo under specific conditions and, when transplanted into the liver of albino rats with STZ-induced diabetes mellitus, were able to secrete insulin and partially control the status of diabetes mellitus in rats.

Synthesis and evaluation of pyrimidoindole analogs in umbilical cord blood ex vivo expansion

The scarcity of hematopoietic stem cells (HSCs) significantly hindered their clinical potentials. Umbilical cord blood (UCB) has become the leading source of HSCs for both research and clinical applications. But the low content of HSCs in a single UCB unit limited its use only to pediatric patients. Various cytokines and small molecules have demonstrated strong abilities in promoting HSC ex vivo expansion, of which UM171 is the newest and by far the most potent HSC ex vivo expansion agent. In this study, we synthesized 37 pyrimidoindole analogs and identified 6 compounds to be potent in promoting HSC ex vivo expansion. In particular, analog 11 was found to be the most effective in stimulating ex vivo expansion of UCB CD34⁺ cells and CD34⁺CD38^- cells. Initial data indicated that compound 11 promoted the absolute number of long term HSCs and inhibited their differentiation. UCB HSCs expanded with 11 retained adequate multi-lineage differentiation capacity. In addition, compound 11 is not cytotoxic at its test concentrations, suggesting that it merits further investigation for potential clinical applications.

Repurposing the public cord blood bank inventory in Korea to enhance cord blood use

To enhance public cord blood (CB) use, we examined the current status of CB banking and tried to suggest revision of the banking standard. We retrospectively analyzed the use of stored public CB units between 2011 and 2016 using data from the CB information center in Korea. A total of 19,871 CB units were registered, and 363 units were selected for transplantation. The transplanted CB units contained significantly higher numbers of CD34+ cells than the average numbers in the stored CB units (5.5 × 10^6 vs. 3.2 × 10^6, p < 0.01). They also contained more total nucleated cells (TNCs) than the average of the stored CB units (13.7 × 10^8 vs. 10.7 × 10^8, p < 0.01). Only 49% of the stored CB units contained>10 × 10^8 TNCs, while 81% of the units transplanted contained >10 × 10^8 TNCs. The average length of cryopreservation of the transplanted CB units was 4.58 years and 95% of them had been stored for less than 10 years. During the study period, 18,763 CB units were requested for research, but only 5,888 were released. This discrepancy was mostly due to errors in regulatory and/or networking elements of the CB supply system. The data suggest that preserving CB units for less than 10 years and increasing the required minimum TNC count to 10 × 10^8 would produce an inventory containing units that were more useful for CBT. CB units that did not meet the requisite quality standards could be used for research, and systems for their fair distribution to researchers are needed.

Transplantation and Alternatives to Treat Autoimmune Diseases

Transplantation is considered as one of the methods for the treatment of autoimmune diseases. There are different sorts of transplantation which improved the situation for the cure of different kinds of autoimmune diseases. Cord blood transplantation is favored over other transplant techniques. The propelled treatments incorporate interferon administrative elements and mesenchymal stromal cells for the management of immune system issue particularly in the treatment of rheumatoid joint inflammation. According to the studies conducted, it was proven that cord blood/UC mesenchymal cells along with DMARDs, without consistent organization expanded the level of administrative regulatory T-cells of the peripheral blood which might be a protected and huge technique for the treatment of patients experiencing rheumatoid joint inflammation. This review article focusses on different organ transplantation and alternative methods to treat autoimmune condition like rheumatoid arthritis. Using 3D printing and artificial intelligence are some of the recent trends that may be used for the management of autoimmune diseases.

A new strategy for umbilical cord blood collection developed at the first Colombian public cord blood bank increases total nucleated cell content

BACKGROUND

The total nucleated cell dosage of umbilical cord blood (UCB) is an important factor in determining successful allogeneic hematopoietic stem cell transplantation after a minimum human leukocyte antigen donor-recipient match. The northern South American population is in need of a new-generation cord blood bank that cryopreserves only units with high total nucleated cell content, thereby increasing the likelihood of use. Colombia set up a public cord blood bank in 2014; and, as a result of its research for improving high total nucleated cell content, a new strategy for UCB collection was developed.

STUDY DESIGN AND METHODS

Data from 2933 collected and 759 cryopreserved cord blood units between 2014 and 2015 were analyzed. The correlation of donor and collection variables with cellularity was evaluated. Moreover, blood volume, cell content, CD34+ count, clonogenic capacity, and microbial contamination were assessed comparing the new method, which combines in utero and ex utero techniques, with the conventional strategies.

RESULTS

Multivariate analysis confirmed a correlation between neonatal birth weight and cell content. The new collection method increased total nucleated cell content in approximately 26% and did not alter pre-cryopreservation and post-thaw cell recovery, viability, or clonogenic ability. Furthermore, it showed a remarkably low microbial contamination rate (1.2%).

CONCLUSION

The strategy for UCB collection developed at the first Colombian public cord blood bank increases total nucleated cell content and does not affect unit quality. The existence of this bank is a remarkable breakthrough for Latin-American patients in need of this kind of transplantation.

The role of policies and networks in development of cord blood usage in China

Research regarding the use of cord blood (CB) has focused on antigen match and the number of stem cells, with policies and networks related to its use being under researched. This article is based on fieldwork in China from 2013 to 2015 and examines ways that the studied CB bank enhances CB usage in China. This article identifies that in addition to finding a match, CB use is linked to the policies and networks, release fee and public awareness that enable CB usage development.

Effect of human umbilical cord blood mesenchymal stem cells administered by intravenous or intravitreal routes on cryo-induced retinal injury

Traumatic optic neuropathy is an important cause of severe vision loss. So, many attempts were performed to transplant stem cells systemically or locally to regenerate the injured retina. In this study, we investigated the effect of human umbilical cord blood mesenchymal stem cells (hUBMSCs) on histological structure, apoptotic, antiapoptotic, oxidant and antioxidant markers in an experimental model of cryo-induced retinal damage in mice. Forty-eight mice were included with 4 major groups; group I contained 18 mice as controls. The others included 30 mice exposed to cryo-induced retinal injury and were subdivided into three equal groups: group II received no treatment after injury. Group III was intravenously injected with hUCBMSCs after injury and group IV received an intravitreal injection with hUCBMSCs into both eyes. Retinal tissues were used for histopathological, immunological and gene expression studies. Real time-PCR was performed to assess B-cell lymphoma 2 (bcl2), Bcl2-associated X protein (bax), heme oxygenase-1 (hmox-1) and thioredoxin-2 (tnx-2) expression and to assess the differentiation of the stem cells into the retinal tissue. Immunohistochemical analysis was performed to assess caspase-3, 3-nitrotyrosine (3-NT) and basic fibroblast growth factor (bFGF). Disturbed retinal structure was seen in cryo-injured mice while hUCBMSCs treated groups showed nearly normal structure. By real time-PCR, significantly reduced mRNA expressions of Bax and notably enhanced mRNA expression of Bcl-2, hmox-1 and txn-2 were demonstrated in retinal injured mice with hUCBMSCs treatment compared to those without. In addition, immunohistochemical analysis confirmed downregulation of 3-NT and caspase-3 and upregulation of bFGF after hUCBMSCs injection in injured retina. Furthermore, there was no differentiation of transplanted stem cells into the retinal tissue. In conclusions, hUCBMSCs could improve the morphological retinal structure in cryo-induced retinal damage model by modulation of the oxidant-apoptotic status and by increased the expression of bFGF. © 2017 IUBMB Life, 69(3):188-201, 2017.

Comparison of cyclosporine and tacrolimus combined with mycophenolate mofetil in prophylaxis for graft-versus-host disease after reduced-intensity umbilical cord blood transplantation

Umbilical cord blood transplantation with a reduced-intensity conditioning regimen (RIC-UCBT) is used increasingly in patients who have comorbid organ functions and lack human leukocyte antigen-identical donors. We compared the outcomes in 35 patients who received mycophenolate mofetil plus cyclosporine (MMF/CSP, n = 17) or MMF plus tacrolimus (MMF/TAC, n = 18) for graft-versus-host disease (GVHD) prophylaxis after RIC-UCBT. Cumulative incidence of neutrophil engraftment was 94 and 89 % in MMF/CSP and MMF/TAC groups, respectively (p = 0.34). The incidence of pre-engraftment immune reaction did not differ between the MMF/CSP (41 %) and MMF/TAC (39 %, p = 1.00) groups; however, patients in the MMF/TAC group tended to have a lower incidence of grade II-IV acute GVHD than those in MMF/CSP group (28 vs 53 %, p = 0.11). Overall survival (OS) at 1 year was 43 and 60 % in MMF/CSP and MMF/TAC groups, respectively (p = 0.39). Progression-free survival, non-relapse mortality, and relapse rate were comparable between the two groups (p = 0.76, 0.59, and 0.88, respectively). In multivariate analyses, MMF/TAC GVHD prophylaxis was closely associated with improved OS, but not with incidence of engraftment and acute GVHD. These results suggest that more intensive GVHD prophylaxis with MMF/TAC decreased acute GVHD without affecting other clinical outcomes, resulting in improved OS after RIC-UCBT.

Factors That Influence a Mother's Willingness to Preserve Umbilical Cord Blood: A Survey of 5120 Chinese Mothers

BACKGROUND

Umbilical Cord blood (UCB), which contains a substantive number of stem cells, could be widely used in transplants to treat a variety of oncologic, genetic, hematologic, and immunodeficiency disorders. However, only a small portion of mothers preserve or donate their UCB in China. The limited availability of UCB has hampered stem cell research and therapy nowadays. To date, no systemic investigations regarding factors that influence a mother's willingness to preserve UCB have been performed in China. In the current study, we are trying to determine those factors which will provide useful information for national health policy development and will raise awareness of the importance of UCB preservation.

METHODS

During 2011 to 2013, 5120 mothers with the average age of 26.1±8.4 years were included in this study. Those mothers participated in a standardized survey. The information gathered consisted of delivery time, occupation, level of education, knowledge of preservation of UCB, willingness to store UCB, and related concerns. The results have been analyzed with SPSS 16.0.

RESULTS

The results showed that first-time mothers showed a greater willingness to preserve their UCB (73.3%) compared to those having their second (48.9%) or third child (40.3%). Mothers who were employed at Government Agencies and Organizations were more willing to preserve their UCB (87.3%) than those employed at factories (62.0%), and those who were unemployed (27.3%). Mothers holding master's or college degrees were more willing to preserve their UCB (72.5% and 71.1%, respectively) than mothers with high school diplomas (48.7%) or those who only went to preliminary school or middle school (40.7%). The two strongest factors that influenced an unwillingness to preserve UCB were the high cost and concerns regarding the safety of the preservation.

CONCLUSIONS

The results showed that mothers with higher education or those having better occupations are more likely to preserve their UCB in China. These mothers have related knowledge and understand the importance of the preservation and they could more readily afford the relatively high cost. The government, clinicians and UCB banks should combine efforts to take measures, such as increasing public knowledge of the importance of UCB preservation and decreasing the high cost for its storage will most likely increase the frequency of UCB preservation which will further benefit stem cell research and therapy.

Ex vivo expansion of hematopoietic stem cells

Ex vivo expansion of hematopoietic stem cells (HSCs) would benefit clinical applications in several aspects, to improve patient survival, utilize cord blood stem cells for adult applications, and selectively propagate stem cell populations after genetic manipulation. In this review we summarize and discuss recent advances in the culture systems of mouse and human HSCs, which include stroma/HSC co-culture, continuous perfusion and fed-batch cultures, and those supplemented with extrinsic ligands, membrane transportable transcription factors, complement components, protein modification enzymes, metabolites, or small molecule chemicals. Some of the expansion systems have been tested in clinical trials. The optimal condition for ex vivo expansion of the primitive and functional human HSCs is still under development. An improved understanding of the mechanisms for HSC cell fate determination and the HSC culture characteristics will guide development of new strategies to overcome difficulties. In the future, development of a combination treatment regimen with agents that enhance self-renewal, block differentiation, and improve homing will be critical. Methods to enhance yields and lower cost during collection and processing should be employed. The employment of an efficient system for ex vivo expansion of HSCs will facilitate the further development of novel strategies for cell and gene therapies including genome editing.

Postthaw characterization of umbilical cord blood: markers of storage lesion

BACKGROUND

The continued growth in the uses of umbilical cord blood (UCB) will require the development of meaningful postthaw quality assays. This study examines both conventional and new measures for assessing UCB quality after long-term storage.

STUDY DESIGN AND METHODS

The first arm of the study involved thawing UCB in storage for short (approx. 1 year) and long periods of time (>11 years). Conventional postthaw measures (colony-forming units [CFU], total nucleated cell counts, CD34+45+) were quantified in addition to apoptosis. The second arm of the study involved taking units stored in liquid nitrogen and imposing a storage lesion by storing the units in -80°C for various periods of time. After storage lesion, the units were thawed and assessed.

RESULTS

In the first arm of the study, there was little difference in the postthaw measures between UCB stored for short and long periods of time. There was a slight increase in the percentage of CD34+45+ cells with time in storage and a reduction in the number of cells expressing apoptosis markers. When moved from liquid nitrogen to -80°C storage, the nucleated cell count varied little but there was a distinct decrease in frequency of CFUs and increase in percentage of cells expressing both early and late markers of apoptosis.

CONCLUSION

Nucleated cell counts do not reflect damage to hematopoietic progenitors during long-term storage. Expression of caspases and other markers of apoptosis provide an early biomarker of damage during storage, which is consistent with other measures such as CFU and percentage of CD34+45+ cells.

Superselective intra-arterial umbilical cord blood administration to BM in experimental animals

Umbilical cord blood (UCB) as a source of hematopoietic stem cells for transplantation is limited by the low number of cells and delayed engraftment. UCB cells are infused i.v. for transplantation, although only a proportion of the cells reach the BM. We investigated whether UCB could be administered safely using superselective intra-arterial (i.a.) injection. We injected human UCB (5 × 10⁶) into the aorta in rats, into the iliac artery in mice and into the femoral nutrient artery (FNA) in rabbits. We used angiography, immunohistochemistry, intravital microscopy and qPCR to assess safety end points and the distribution of injected cells. All animals showed normal behavior. No evidence of organ infarction was noted. UCB injected into the FNA of rabbits did not change the flow rates, measured by angiography. By qPCR, we found significantly higher fold-change values in the injected BM compared with i.v. injection (P=0.0087). Using intravital microscopy we visualized the mouse capillary bed during i.a. injection without cellular congestion. In summary, we show that i.a. infusion of UCB is safe and reaches an eightfold increase in engraftment in the BM compared with i.v. infusion. These studies lay the foundation for clinical trials.

Fetal stem cells and skeletal muscle regeneration: a therapeutic approach

More than 40% of the body mass is represented by muscle tissue, which possesses the innate ability to regenerate after damage through the activation of muscle-specific stem cells, namely satellite cells. Muscle diseases, in particular chronic degenerative states of skeletal muscle such as dystrophies, lead to a perturbation of the regenerative process, which causes the premature exhaustion of satellite cell reservoir due to continuous cycles of degeneration/regeneration. Nowadays, the research is focused on different therapeutic approaches, ranging from gene and cell to pharmacological therapy, but still there is no definitive cure in particular for genetic muscle disease. Keeping this in mind, in this article, we will give special consideration to muscle diseases and the use of fetal derived stem cells as a new approach for therapy. Cells of fetal origin, from cord blood to placenta and amniotic fluid, can be easily obtained without ethical concern, expanded and differentiated in culture, and possess immune-modulatory properties. The in vivo approach in animal models can be helpful to study the mechanism underneath the operating principle of the stem cell reservoir, namely the niche, which holds great potential to understand the onset of muscle pathologies.

Endothelial cells provide a niche for placental hematopoietic stem/progenitor cell expansion through broad transcriptomic modification

Umbilical cord blood (UCB) is an attractive source of hematopoietic stem cells (HSCs). However, the number of HSCs in UCB is limited, and attempts to amplify them in vitro remain inefficient. Several publications have documented amplification of hematopoietic stem/progenitor cells (HSPCs) on endothelial or mesenchymal cells, but the lack of homogeneity in culture conditions and HSC definition impairs direct comparison of these results. We investigated the ability of different feeder layers, mesenchymal progenitors (MPs) and endothelial cells (ECs), to amplify hematopoietic stem/progenitor cells. Placental derived HSPCs (defined as Lin(-)CD45(-/dim)CD34(+)CD38(-)CD90(+)) were maintained on confluent feeder layers and the number of cells and their marker expression were monitored over 21 days. Although both types of feeder layers supported hematopoietic expansion, only endothelial cells triggered amplification of Lin(-)CD45(-/dim)CD34(+)CD38(-)CD90(+) cells, which peaked at 14 days. The amplified cells differentiated into all cell lineages, as attested by in vitro colony-forming assays, and were capable of engraftment and multi-lineage differentiation in sub-lethally irradiated mice. Mesenchymal progenitors promoted amplification of CD38(+) cells, previously defined as precursors with more limited differentiation potential. A competitive assay demonstrated that hematopoietic stem/progenitor cells had a preference for interacting with endothelial cells in vitro. Cytokine and transcriptomic analysis of both feeder cell types identified differences in gene expression that correlated with propensity of ECs and MPs to support hematopoietic cell amplification and differentiation respectively. Finally, we used RNA sequencing of endothelial cells and HSPCs to uncover relevant networks illustrating the complex interaction between endothelial cells and HSPCs leading to stem/progenitor cell expansion.

The Role of HLA in Cord Blood Transplantation

In recent years, umbilical cord blood (CB), a rich source of hematopoietic stem cells (HSC), has been used successfully as an alternative HSC source to treat a variety of hematologic, immunologic, genetic, and oncologic disorders. CB has several advantages, including prompt availability of the transplant, decrease of graft versus host disease (GVHD) and better long-term immune recovery, resulting in a similar long-term survival. Studies have shown that some degree of HLA mismatches is acceptable. This review is intended to outline the main aspects of HLA matching in different settings (related, pediatric, adult, or double-unit HSCT), its effect on transplantation outcome and the role of HLA in donor selection.

Comparative in vitro analysis of different hematopoietic cell populations from human cord blood: in search of the best option for clinically oriented ex vivo cell expansion

BACKGROUND

Ex vivo expansion of hematopoietic stem and progenitor cells has become a priority in the experimental hematology arena. In this study we have obtained different hematopoietic cell populations from umbilical cord blood and simultaneously assessed their proliferation and expansion kinetics. Our main goal was to determine which one of these cell populations would be more suitable for clinical-grade ex vivo expansion.

STUDY DESIGN AND METHODS

By using immunomagnetic-negative selection and cell sorting, five cell populations were obtained: unseparated mononuclear cells (MNCs; I); two lineage-negative cell populations, one enriched for CD34+ CD38+ cells (II) and the other enriched for CD34+ CD38- cells (III); and two CD34+ cell fractions purified by fluorescence-activated cell sorting, one containing CD34+ CD38+ cells (IV) and the other containing CD34+ CD38- cells (V). The kinetics of such populations were analyzed in both relative and absolute terms.

RESULTS

No expansion was observed in Population I; in contrast, significant increments in the numbers of both progenitor and stem cells were observed in cultures of Populations II to V. Population V (reaching 12,800-fold increase in total cells; 1280-fold increase in CD34+ cells; 490-fold increase in colony-forming cells; and 12-fold increase in long-term culture-initiating cells) showed the highest proliferation and expansion potentials.

CONCLUSION

Our study suggests that the cell fraction containing greater than 98% CD34+ CD38- cells would be the ideal one for large-scale ex vivo expansion; however, based on our data, it seems that, except for MNCs, all other cell populations could also be used as input cell fractions.

Acute maternal cytomegalovirus infection is associated with significantly decreased numbers of CD34+ cells in umbilical cord blood

OBJECTIVE AND BACKGROUND

There is little information regarding the serologic status of umbilical cord blood (UCB) donors. Cytomegalovirus (CMV) is the most frequent agent transmitted by blood products and studies have reported that CMV can inhibit myelopoiesis, however, its effects on the cellular content of UCB have not been documented.

STUDY DESIGN AND METHODS

We investigated, retrospectively, the prevalence of serological evidence of infection in 857 women donating their UCB at a public university hospital and studied the influence of acute CMV exposure on UCB content of CD34+ cells. The biological characteristics of UCB from serology positive-donors were compared with those of women with negative tests.

RESULTS

We found that 51 of 857 (6%) UCB units were positive for infectious disease markers; anti-CMV IgM was the most prevalent marker, 43 of 51 (86%) of cases with infectious markers. UCB collected from anti-CMV IgM-positive donors more frequently met rejection criteria for use as a transplanation product. The CD34+ cell count was the most often affected, 2.48×10(6) in anti-CMV IgM-positive donors compared to 1.48×10(6) in unaffecetd donors( p=0.006). The probability of a UCB meeting a CD34+ cell content≥2×10(6) was significantly lower in units from IgM anti-CMV+ women compared to unaffecetd donors [Odds ratio (OR)=0.428 (95% CI 0.182-0.632; p=0.015]; the total nucleated cell count (TNC) was lower but not statistically significant [p=0.068].

CONCLUSION

UCB donated by anti-CMV IgM-positive women has a high probability of not meeting the criteria required for cryopreservation for future use as a transplantation product, because of the low number of CD34+ cells.

US public cord blood banking practices: recruitment, donation, and the timing of consent

BACKGROUND

Cord blood has moved rapidly from an experimental stem cell source to an accepted and important source of hematopoietic stem cells. There has been no comprehensive assessment of US public cord blood banking practices since the Institute of Medicine study in 2005.

STUDY DESIGN AND METHODS

Of 34 US public cord blood banks identified, 16 participated in our qualitative survey of public cord blood banking practices. Participants took part in in-depth telephone interviews in which they were asked structured and open-ended questions regarding recruitment, donation, and the informed consent process at these banks.

RESULTS

Thirteen of 16 participants reported a variably high percentage of women who consented to public cord blood donation. Fifteen banks offered donor registration at the time of hospital admission for labor and delivery. Seven obtained full informed consent and medical history during early labor and eight conducted some form of phased consent and/or phased medical screening and history. Nine participants identified initial selection of the collection site location as the chief mode by which they recruited minority donors.

CONCLUSION

Since 2005, more public banks offer cord blood donor registration at the time of admission for labor and delivery. That and the targeted location of cord blood collection sites are the main methods used to increase access to donation and HLA diversity of banked units. Currently, the ability to collect and process donations, rather than donor willingness, is the major barrier to public cord blood banking.

Concise review: Cord blood banking, transplantation and induced pluripotent stem cell: success and opportunities

Hematopoietic cell transplantation (HCT) has become a standard practice to treat a number of malignant and nonmalignant hematologic diseases. Bone marrow, mobilized peripheral blood, and umbilical cord blood can all serve as primary sources of cells for HCT. The number of cord blood units currently stored is large, although it represents only a fraction of potential collections. With much of the collection being sequestered in private banks for possible autologous use, there is a reason to expect that public banks may not be able to provide for the demand in coming years as use of cord blood for treatment of patients with diseases such as leukemia and lymphoma continues to increase. We suggest that a possible solution to encourage private banks to share their valuable units is to apply recent methodologies to generate induced pluripotent stem cells from cord cells and to optimize techniques to generate hematopoietic lineages from them. This strategy would allow us to take advantage of the units already collected under appropriate regulatory guidelines, to access a pristine cell that can be converted to a pluripotent cell at a much higher efficiency and in a shorter time period than other cells. The ability to potentially replenish a used cord unit with new cells, as well as extend the potential utility of cord blood for additional therapeutic applications, should allow banks to develop an appropriate business model for both private and public cord blood banks to flourish.

Treatment-related myelodysplasia in patients with primary brain tumors

Treatment-related myelodysplastic syndrome (t-MDS) and treatment-related acute myelogenous leukemia (t-AML) represent rare secondary events in patients with primary tumors of the nervous system and predominantly affect those treated with alkylating agents or topoisomerase II inhibitors. Temozolomide has become the standard chemotherapeutic agent for malignant gliomas. The emergence of this alkylating agent with little acute toxicity or cumulative myelosuppression has led to off-label protracted chemotherapy for many patients with malignant and even low-grade infiltrative gliomas, raising concern for increased risk of t-MDS/t-AML in the few long-term survivors. On the basis of an extensive literature search, we provide a discussion of epidemiology, pathogenesis, clinical presentation, diagnosis, and therapy of these disorders. t-MDS/t-AML remain rare complications of chemotherapy in patients with primary brain tumors, and the vast majority of patients die of their primary neoplasm. Prospective randomized studies with long-term follow-up are required to accurately assess the risk of t-MDS/t-AML; however, unless survival in the most common gliomas substantially increases, t-MDS/t-AML incidence will likely remain low in this patient population.

Cord Blood Banking and Transplantation in China: A Ten Years Experience of a Single Public Bank

BACKGROUND: Umbilical cord blood (UCB) has successfully used for transplantation to treat hematologic malignancies and genetic diseases. Herein, we describe the experience generated in a single public UCB bank at Zhejiang Province in China. METHODS: Good manufacturing practice and standard operating procedures were used to address donor selection as well as UCB collection, processing, and cryopreservation. Total nucleated cells (TNCs), cellular viability, CD34+ cells, and colony-forming units were determined, and infectious diseases screening test, sterility test, and HLA typing for UCB units were done. RESULTS: Only 18.51% of all collected UCB units met storage criteria, and 7,056 UCB units were cryopreserved in 10 years. The volume of UCB units was 95.0 ± 22.0 ml. The number of TNCs before and after processing was 13.32 ± 3.63 × 10(8) and 10.63 ± 2.80 × 10(8), respectively, and the recovery rate was 80.71 ± 11.26%. 0.4344 ± 0.1874% of the TNCs were CD34+ cells. The CFU-GM was 32.1 ± 28.0 colonies per 1 × 10(5) nucleated cells. Based mainly on HLA and nucleated cell content, 26 UCB units were released for transplantation. CONCLUSIONS: A public UCB bank was successfully established in China; collection and processing of UCB units should be optimized in order to gain maximum volume and cell count.

Effects of mixed feeder cells on the expansion of CD34⁺ cells

Synergistic effects of mesenchymal stem cells (MSCs) isolated from bone marrow (BM), umbilical cord blood (UCB) and periosteum, and fibroblasts as mixed feeder cells (MFCs) on the expansion of hematopoietic progenitor cells (HPCs) were investigated in serum- and exogenous cytokine-free conditions. Enriched CD34(+) cells were cultured for 2weeks over the cell lines alone, individually, or selected combinations of them. When the cells were cultured over MFCs, the maximum increase in expansion of total nucleated cells and CD34(+)/CD38(-) cells was 157.3- and 128.6-fold, respectively. Furthermore, hematopoietic cytokine such as IL-6 and chemokines (e.g., IL-8, growth related oncogene (GRO), GRO-alpha, matrix metalloproteinase (MMP)-1, and MMP-3) were significantly increased in mixed feeder cells. Based on these results, MFCs can be more efficient for the ex vivo expansion of HPCs. These results strongly suggest that MFCs are more suitable for HPCs mass production.

Relationship of race/ethnicity and survival after single umbilical cord blood transplantation for adults and children with leukemia and myelodysplastic syndromes

The relationship of race/ethnicity with outcomes of umbilical cord blood transplantation (UCBT) is not well known. We analyzed the association between race/ethnicity and outcomes of unrelated single UCBT for leukemia and myelodysplastic syndromes. Our retrospective cohort study consisted of 885 adults and children (612 whites, 145 blacks, and 128 Hispanics) who received unrelated single UCBT for leukemia and myelodysplastic syndromes between 1995 and 2006 and were reported to the Center for International Blood and Marrow Transplant Research. A 5-6/6 HLA-matched unit with a total nucleated cell count infused of ≥2.5 × 10(7)/kg was given to 40% white and 42% Hispanic, but only 21% black patients. Overall survival at 2 years was 44% for whites, 34% for blacks, and 46% for Hispanics (P = .008). In multivariate analysis adjusting for patient, disease, and treatment factors (including HLA match and cell dose), blacks had inferior overall survival (relative risk of death, 1.31; P = .02), whereas overall survival of Hispanics was similar (relative risk, 1.03; P = .81) to that of whites. For all patients, younger age, early-stage disease, use of units with higher cell dose, and performance status ≥80 were independent predictors of improved survival. Black patients and white patients infused with well-matched cords had comparable survival; similarly, black and white patients receiving units with adequate cell dose had similar survival. These results suggest that blacks have inferior survival to whites after single UCBT, but outcomes are improved when units with a higher cell dose are used.

Differential effects of HOXB4 and NUP98-HOXA10hd on hematopoietic repopulating cells in a nonhuman primate model

Expansion of hematopoietic stem cells (HSCs) is beneficial in settings where HSC numbers are limited, such as cord blood transplantation. The human homeobox transcription factor HOXB4 has been shown to enhance stem cell expansion in several experimental models. We have shown previously that HOXB4 overexpression in monkey CD34(+) cells has a dramatic effect on expansion and engraftment of short-term repopulating cells. Here, we wished to compare the effects of HOXB4 and another candidate gene, NUP98-HOXA10hd (NA10hd). We used a competitive repopulation assay in pigtailed macaques to study engraftment of CD34(+) cells modified with gammaretroviral HOXB4YFP or NA10hdGFP. We found that HOXB4YFP contributed more to early hematopoiesis (<30 days), whereas NA10hdGFP contributed more to later hematopoiesis. In each case, we observed two distinct peaks in engraftment of NA10hd-transduced cells, one within 20 days post transplant and another after 5-6 months. Analysis of CD14(+), CD3(+), and CD20(+) subsets confirmed that higher percentages of cells of each lineage were derived from NA10hdGFP(+) progenitors than from HOXB4YFP(+) progenitors. In conclusion, we show that HOXB4 and NA10hd both have a significant impact on hematopoietic reconstitution; however, these effects are differential and therefore may offer complementary strategies for HSC expansion.

The effect of nanofibre surface amine density and conjugate structure on the adhesion and proliferation of human haematopoietic progenitor cells

Previous studies have shown that substrate surface chemistry and topography exhibit significant impact on haematopoietic progenitor cell adhesion, proliferation and differentiation. In the present study, the effect of surface amine density and structure of grafted polymer chains on the adhesion and expansion of haematopoietic progenitor cells was investigated. Cryopreserved human umbilical cord blood CD133(+) cells were expanded in cytokine-supplemented medium on ethylenediamine (EDA)- or 2-aminoethyl methacrylate hydrochloride (AEMA)-grafted polyethersulphone (PES) nanofibre scaffolds for 10 days. Although the percentage of CD34(+) cells among the expanded cells increased with the surface amine density, the maximum fold expansion of CD34(+) cells was obtained at a moderate amine density of 20-80 nmol cm(-2). When comparing nanofibre matrices with similar amine densities, but prepared with two different methods, cells cultured on the AEMA-grafted PES nanofibre matrix showed lower fold expansion in terms of total cell number (300 ± 84 fold) and CD34(+) cell number (68 ± 19-fold) in comparison with those cultured on EDA-grafted nanofibres (787 ± 84-fold and 185 ± 84-fold, respectively). These results indicate that the surface amine density and the conjugate structure are important determinants for the preservation of CD34 surface marker and expansion efficiency of CD34(+) cells.

Surgical Therapy of End-Stage Heart Failure: Understanding Cell-Mediated Mechanisms Interacting with Myocardial Damage

Worldwide, cardiovascular disease results in an estimated 14.3 million deaths per year, giving rise to an increased demand for alternative and advanced treatment. Current approaches include medical management, cardiac transplantation, device therapy, and, most recently, stem cell therapy. Research into cell-based therapies has shown this option to be a promising alternative to the conventional methods. In contrast to early trials, modern approaches now attempt to isolate specific stem cells, as well as increase their numbers by means of amplifying in a culture environment. The method of delivery has also been improved to minimize the risk of micro-infarcts and embolization, which were often observed after the use of coronary catheterization. The latest approach entails direct, surgical, transepicardial injection of the stem cell mixture, as well as the use of tissue-engineered meshes consisting of embedded progenitor cells.

Stability of hepatitis C virus, HIV, and hepatitis B virus nucleic acids in plasma samples after long-term storage at -20°C and -70°C

The storage of biological samples may affect detection of viral nucleic acid, yet the stability of viral nucleic acid at standard laboratory storage temperatures (-70°C and -20°C) has not been comprehensively assessed. Deterioration of viral RNA and DNA during storage may affect the detection of viruses, thus leading to an increased likelihood of false-negative results on diagnostic testing. The viral loads of 99 hepatitis C virus (HCV), 41 HIV, and 101 hepatitis B virus (HBV) patient samples were measured before and after storage at -20°C and -70°C for up to 9.1 years using Versant branched DNA assays, Cobas Monitor assays, and/or AmpliPrep/AmpliScreen assays. Clinical samples stored at -20°C for up to 1.2 years and at -70°C for up to 9 years showed a statistically significant difference from baseline with respect to HCV RNA titer, although this difference was not greater than 0.5 log(10) unit. The concentration of HIV RNA in clinical samples stored at -20°C for 2.3 years and at -70°C for up to 9.1 years did not differ significantly from the baseline viral load. HBV DNA-positive clinical samples stored at -20°C for up to 5 years and at -70°C for up to 4 years differed significantly in viral load. In all studies, however, the loss of viral load of HCV, HIV, or HBV in clinical samples tested after storage at -20°C and -70°C for up to 9 years ranged from 0.01 to 0.35 log(10) IU/ml and did not exceed 0.5 log(10), which is the estimated intra-assay variation for molecular tests. Hence, the loss was considered of minimal clinical impact and adequate for the detection of HCV, HIV-1, and HBV nucleic acids using nucleic acid assays for the assessment of the infectious risk of cell, blood, and tissue donors.

The current status of umbilical cord blood collection in Japanese medical centers: survey of obstetricians

As the first step of UCB banking, UCB collection has an important role in banking procedures. The aim of this study was to reveal the current status of UCB collection and discuss the management of the UCB bank. We conducted a questionnaire survey at medical centers collecting UCB, followed by semi-structured interviews with some respondents. Out of 38 institutes, 11 respondents (28.9%) thought that collection of UCB in addition to their routine medical services puts a burden on physicians. The obstetricians involved in the UCB collection are generally willing to participate in the procedure under current circumstances at medical institutes.

Improved engraftment with minimal graft-versus-host disease after major histocompatibility complex-mismatched cord blood transplantation with photochemically treated donor lymphocytes

There is a significant risk of severe graft-versus-host disease (GVHD) and graft failure after unrelated umbilical cord blood transplantation (CBT) if donor-recipient pairs are mismatched at major histocompatibility complex (MHC) loci. To mitigate these risks after MHC-mismatched CBT, we infused psoralen-treated, photochemically inactivated, mature donor T-lymphocytes with MHC (H2-haplotype) mismatched murine donor fetal near-term peripheral blood (FNPB) cells after sublethal irradiation. We analyzed the rates of donor engraftment, GVHD and long-term survival in H2 haplotype disparate (C57BL/6 [H-2(b)/Thy1.1] → AKR [H-2(k)/Thy1.2]) recipient mice. We observed inconsistent donor engraftment after transplantation with cord blood alone, but superior engraftment and long-term survival after FNPB transplantation supplemented with psoralen-treated donor T-lymphocytes. Additionally, there was fatal GVHD after FNPB co-infusion with untreated donor T-lymphocytes, but minimal GVHD after FNPB supplemented with psoralen-treated donor T-lymphocytes transplantation. Donor MHC(high)/c-Kit(+)/lineage(-)/CD34(-) stem cells were noted in the recipient bone marrow compartment following co-infusion of photochemically inactivated T-cells with FNPB. Despite the non-myeloablative preparation before FNPB infusion, complete hematological recovery was delayed until 50-60 d after transplantation. We observed that co-transplantation of psoralen-treated donor T-lymphocytes with FNPB facilitated durable engraftment of donor hematopoietic stem cells in the marrow and splenic compartments with complete but delayed recovery of all hematopoietic lineages. This CBT model establishes the possibility of ensuring donor engraftment across a MHC barrier without severe GVHD.

The inherent differentiation program of short-term hematopoietic repopulating cells changes during human ontogeny

Human umbilical cord blood (CB) could be an attractive source of hematopoietic repopulating cells for clinical stem cell therapy because of its accessibility and low propensity for unwanted immune reaction against the host. However, CB recipients suffer from severely delayed and often chronically deficient platelet recovery of unknown cause. Here we show that human short-term repopulating cells (STRCs), which predominantly carry early hematopoietic reconstitution after transplantation, display an intrinsically fixed differentiation program in vivo that changes during ontogeny. Compared to adult sources of hematopoietic cells, CB myeloidrestricted STRC-M showed a markedly reduced megakaryocytic and erythroid cell output in the quantitative xenotransplantation of human short-term hematopoiesis in NOD/SCID-beta2m(-/-) mice. This output in vivo was not altered by pre-treating CB cells before transplantation with growth factors that effectively stimulate megakaryocytopoiesis in vitro. Moreover, injecting mice with granulocyte colony-stimulating factor did not affect the differentiation of human STRC. These findings demonstrate that the differentiation capacity of human STRCs is developmentally regulated by mechanisms inaccessible to currently available hematopoietic growth factors, and explain why thrombopoiesis is deficient in clinical CB transplantation.

Biological characteristics of stem cells from foetal, cord blood and extraembryonic tissues

Foetal stem cells (FSCs) can be isolated during gestation from many different tissues such as blood, liver and bone marrow as well as from a variety of extraembryonic tissues such as amniotic fluid and placenta. Strong evidence suggests that these cells differ on many biological aspects such as growth kinetics, morphology, immunophenotype, differentiation potential and engraftment capacity in vivo. Despite these differences, FSCs appear to be more primitive and have greater multi-potentiality than their adult counterparts. For example, foetal blood haemopoietic stem cells proliferate more rapidly than those found in cord blood or adult bone marrow. These features have led to FSCs being investigated for pre- and post-natal cell therapy and regenerative medicine applications. The cells have been used in pre-clinical studies to treat a wide range of diseases such as skeletal dysplasia, diaphragmatic hernia and respiratory failure, white matter damage, renal pathologies as well as cancers. Their intermediate state between adult and embryonic stem cells also makes them an ideal candidate for reprogramming to the pluripotent status.

Expansion of cord blood CD34 cells in presence of zVADfmk and zLLYfmk improved their in vitro functionality and in vivo engraftment in NOD/SCID mouse

Background

Cord blood (CB) is a promising source for hematopoietic stem cell transplantations. The limitation of cell dose associated with this source has prompted the ex vivo expansion of hematopoietic stem and progenitor cells (HSPCs). However, the expansion procedure is known to exhaust the stem cell pool causing cellular defects that promote apoptosis and disrupt homing to the bone marrow. The role of apoptotic machinery in the regulation of stem cell compartment has been speculated in mouse hematopoietic and embryonic systems. We have consistently observed an increase in apoptosis in the cord blood derived CD34⁺ cells cultured with cytokines compared to their freshly isolated counterpart. The present study was undertaken to assess whether pharmacological inhibition of apoptosis could improve the outcome of expansion.

Methodology/Principal Findings

CB CD34⁺ cells were expanded with cytokines in the presence or absence of cell permeable inhibitors of caspases and calpains; zVADfmk and zLLYfmk respectively. A novel role of apoptotic protease inhibitors was observed in increasing the CD34⁺ cell content of the graft during ex vivo expansion. This was further reflected in improved in vitro functional aspects of the HSPCs; a higher clonogenicity and long term culture initiating potential. These cells sustained superior long term engraftment and an efficient regeneration of major lympho-myeloid lineages in the bone marrow of NOD/SCID mouse compared to the cells expanded with growth factors alone.

Conclusion/Significance

Our data show that, use of either zVADfmk or zLLYfmk in the culture medium improves expansion of CD34⁺ cells. The strategy protects stem cell pool and committed progenitors, and improves their in vitro functionality and in vivo engraftment. This observation may complement the existing protocols used in the manipulation of hematopoietic cells for therapeutic purposes. These findings may have an impact in the CB transplant procedures involving a combined infusion of unmanipulated and expanded grafts.

Use of umbilical cord blood for stem cell research

Umbilical cord blood (UCB), long treated as waste material, is today considered a valuable source of hematopoietic stem cells. UCB is used, mostly in children, for the treatment of blood malignancies and inherited blood and metabolic disorders. In addition to blood precursor cells, UCB also contains stem cells that can differentiate into other types, such as cartilage, fat, hepatic, cardiac, and neural cells, fuelling speculation about the use of cord blood stem cells for regenerative medicine. Further research is therefore needed to investigate the expanded potential of UCB and its therapeutic use in cell and tissue therapies. According to a recent survey, practices for the procurement of UCB for research vary widely across Canada, so this area may not yet be ready for uniform regulation. However, some harmonization of practices to increase the availability of UCB for research would be useful for Canadian investigators. In this article, we address several important ethical and legal issues relating to the use of UCB in research and recommend guidelines to serve as a source of useful information for researchers. While their legal acceptability may vary across Canada, it is hoped that these recommendations foster more harmonized UCB research practices.

Recent advances in hematopoietic stem cell transplantation and perspectives of RNAi applications

In adults, the bone marrow compartment contains hematopoietic stem cells (HSCs) which can differentiate into progenitors with more restricted lineage potential and generate all cellular elements of the blood. HSCs for stem cell transplantation can be obtained by bone marrow collection, mobilization into peripheral blood followed by apheresis, or use of stem cells from cord blood. Currently, hematopoietic stem cell transplantation (SCT) is used to treat patients with various hematological diseases. Although substantial progress has been made, a number of challenges can limit the efficacy of HSC transplantation, including the occurrence of graft-versus-host disease (GvHD) in allogeneic stem cell transplantation (ASCT), the susceptibility of patients to opportunistic infections and relapse of malignancies after SCT. Recent studies indicate that small interfering RNAs (siRNAs) can specifically and efficiently interfere with the expression of oncogenic genes. Therefore, the possibility of interfering with the expression of these proteins in hematopoietic cells may offer a new option to correct cell differentiation and function. In addition to the generation of T cells restricted by nonself MHC as reviewed by Stauss and colleagues in 1999, the modulation of NK cell receptor expression and T-cell activation is a new strategy that could limit GvHD. This chapter reviews the recent advances in ASCT and discusses the potential application of RNAi in hematopoietic cells.

Stem cell biobanks

Stem cells contribute to innate healing and harbor a promising role for regenerative medicine. Stem cell banking through long-term storage of different stem cell platforms represents a fundamental source to preserve original features of stem cells for patient-specific clinical applications. Stem cell research and clinical translation constitute fundamental and indivisible modules catalyzed through biobanking activity, generating a return of investment.

Pregnant women's knowledge and attitudes about stem cells and cord blood banking

AIM

This study was to determine pregnant women's knowledge and attitudes towards stem cells and cord blood banking in Istanbul, Turkey.

BACKGROUND

Stem cell research is one of the most important and, at the same time, the most controversial topics of science and technology today. Nurses need to understand stem cell research so they can enter the debate on this issue. They can become important sources of information in order to help parents understand the issues.

METHODS

This exploratory descriptive study was conducted in two antenatal outpatient clinics in Istanbul. The sample consisted of 334 pregnant women during routine prenatal visits. Data were collected in interviews by using an interview form developed by the researchers according to the literature. The form included demographic characteristics of participants and 20 questions about stem cells, storing cord blood and banking and 10 independent attitude statements.

RESULTS

The majority of the participants had a lack of knowledge about stem cells and cord blood banking and wanted more information. Before pregnancy, they received some information through the media (newspaper, Internet, television, etc.), but unintentionally. It was determined that they wanted information before becoming pregnant, more from their obstetrician but also from nurses and midwives. The majority also wanted to store their infants' cord blood and stated that they would be more likely to choose a public cord blood bank.

CONCLUSION

Those giving ante- and perinatal care need to offer accurate and scientific counselling services on this subject to parents who need to be informed.