[Clinical effect of umbilical cord blood transplantation in 37 pediatric patients with hematologic malignancies: a single-center experience].

OBJECTIVE: To evaluate the clinical effect of umbilical cord blood transplantation (UCBT) in children with hematologic malignancies. METHODS: A retrospective analysis was performed on the clinical data of 37 pediatric patients with hematologic malignancies that consisted of 14 cases of acute lymphocyte leukemia, 9 cases of acute myeloid leukemia, 5 cases of juvenile myelomonocytic leukemia, 3 cases of chronic myeloid leukemia, 2 cases of acute mixed leukemia, 3 cases of myelodysplastic syndrome, and 1 case of lymphosarcomatous leukemia. Thirty-seven children with hematologic malignancies received UCBT from unrelated donors (34 cases) and related donors (3 cases). Grafts were 6/6 HLA-matched in 5 cases, 5/6 HLA-matched in 12 cases, 4/6 HLA-matched in 11 cases, and 3/6 HLA-matched in 9 cases. Before transplantation, these patients received rabbit antithymocyte globulin-containing conditioning regimen. The myeloablative conditioning regimen was given in 36 cases and the reduced-intensity conditioning regimen in one case. The median age of transplantation was 5.7 years, and the median weight was 20 kg. The grafts that contained a median of 6.2×10(7) total nucleated cells (TNC)/kg and 2.7×10(5) CD34(+) cells/kg were infused. RESULTS: The median times to neutrophil engraftment and platelet engraftment were 12 days and 25 days, respectively, and the rates of neutrophil engraftment and platelet engraftment were 95% and 78%, respectively. The rate of neutrophil engraftment was positively correlated with the number of CD34(+) cells (P=0.011), while the rate of platelet engraftment was correlated with the numbers of CD34(+) cells and TNC (P=0.001; P=0.014). The incidence rates of acute and chronic graft-versus-host disease were 49% and 11%, respectively. The median follow-up was 54 months. The 5-year transplant-related mortality, overall survival, and disease-free survival were 27%, 57.4% and 41%, respectively. CONCLUSIONS: UCBT is an alternative source of hematopoietic stem cells for patients with hematologic malignancies.

Inhibition of the L-arginine-nitric oxide pathway mediates the antidepressant effects of ketamine in rats in the forced swimming test.

Converging evidence shows that the acute administration of a sub-anaesthetic dose ketamine produces fast-acting and robust antidepressant properties in patients suffering from major depressive disorder. However, the underlying mechanisms have not been fully elucidated. The present study aimed to investigate the role of the L-arginine-nitric oxide pathway in the antidepressant effects of ketamine in rats performing the forced swimming test (FST). Ketamine (10 mg/kg) significantly decreased immobility times in the FST and the activities of total nitric oxide synthases (T-NOS), inducible NOS (iNOS), and endothelial NOS (eNOS) in the rat hippocampus. Interestingly, the plasma activities of T-NOS, iNOS, and eNOS increased after administration of ketamine. Furthermore, the activities of neuronal NOS (nNOS) did not change significantly in either the hippocampus or plasma after ketamine administration. The antidepressant effects of ketamine were prevented by pre-treatment with l-arginine (750 mg/kg). Pre-treatment with the NOS inhibitor L-NG-nitroarginine methyl ester at a sub-antidepressant dose of 50 mg/kg and ketamine at a sub-antidepressant dose of 3 mg/kg reduced immobility time in the FST compared to treatment with either drug alone. None of the drugs affected crossing and rearing scores in the open field test. These results suggest that the L-arginine-nitric oxide pathway is involved in the antidepressant effects of ketamine observed in rats in the FST and this involvement is characterised by the inhibition of brain T-NOS, iNOS, and eNOS activities.

Effectiveness of human mesenchymal stem cells derived from bone marrow cryopreserved for 23-25 years.

OBJECTIVE: To evaluate long-term cryopreserved human bone marrow cells (BMCs) as a source of functional mesenchymal stem cells (MSCs). METHODS: Samples of human BMCs that were cryopreserved for 23-25 years (n=20) were thawed to obtain an initial culture and a primary culture (P(0)) that was propagated through five passages (P(1)-P(5)) to obtain MSCs. Freshly collected human bone marrow samples (n=20) were used as controls for comparison of efficiency of recovery and growth characteristics of MSCs. P(3) cultures were tested for their capacity to differentiate into osteoblasts, adipocytes, and neuronal cells. Appropriate staining, immunohistochemical and biochemical methods were employed to ascertain cell type identities at different stages of culturing. RESULTS: In the initial culture, the cell adherence rate of the cryopreserved cells was significantly lower than that of controls (19.7% vs. 38.2%, p<0.05) while the relative rate of recovery of MSCs was only 48.5±8.6% in P(0). At the end of P(3), fibroblast-like cells accounted for about 95% of cells in both cryopreserved and control groups (p>0.05). These cells were positive for essential MSC surface molecules (CD90, CD105, CD166, CD44, CD29, CD71, CD73) and negative for haematopoietic and endothelial cell markers (CD45, CD34, HLA-DR). The cell growth and cell cycle patterns were similar for both groups. MSCs at P(3) from both groups had similar capacities to differentiate in vitro into osteoblasts, adipocytes, and neuronal cells. CONCLUSION: Using the methods described here, long-term (23-25 years) cryopreserved human BMCs can be successfully cultivated to obtain MSCs that have good differentiation capabilities.

Evidence for positive selection on the leptin gene in Cetacea and Pinnipedia.

The leptin gene has received intensive attention and scientific investigation for its importance in energy homeostasis and reproductive regulation in mammals. Furthermore, study of the leptin gene is of crucial importance for public health, particularly for its role in obesity, as well as for other numerous physiological roles that it plays in mammals. In the present work, we report the identification of novel leptin genes in 4 species of Cetacea, and a comparison with 55 publicly available leptin sequences from mammalian genome assemblies and previous studies. Our study provides evidence for positive selection in the suborder Odontoceti (toothed whales) of the Cetacea and the family Phocidae (earless seals) of the Pinnipedia. We also detected positive selection in several leptin gene residues in these two lineages. To test whether leptin and its receptor evolved in a coordinated manner, we analyzed 24 leptin receptor gene (LPR) sequences from available mammalian genome assemblies and other published data. Unlike the case of leptin, our analyses did not find evidence of positive selection for LPR across the Cetacea and Pinnipedia lineages. In line with this, positively selected sites identified in the leptin genes of these two lineages were located outside of leptin receptor binding sites, which at least partially explains why co-evolution of leptin and its receptor was not observed in the present study. Our study provides interesting insights into current understanding of the evolution of mammalian leptin genes in response to selective pressures from life in an aquatic environment, and leads to a hypothesis that new tissue specificity or novel physiologic functions of leptin genes may have arisen in both odontocetes and phocids. Additional data from other species encompassing varying life histories and functional tests of the adaptive role of the amino acid changes identified in this study will help determine the factors that promote the adaptive evolution of the leptin genes in marine mammals.

Sequence polymorphism and evolution of three cetacean MHC genes.

Sequence variability at three major histocompatibility complex (MHC) genes (DQB, DRA, and MHC-I) of cetaceans was investigated in order to get an overall understanding of cetacean MHC evolution. Little sequence variation was detected at the DRA locus, while extensive and considerable variability were found at the MHC-I and DQB loci. Phylogenetic reconstruction and sequence comparison revealed extensive sharing of identical MHC alleles among different species at the three MHC loci examined. Comparisons of phylogenetic trees for these MHC loci with the trees reconstructed only based on non-PBR sites revealed that allelic similarity/identity possibly reflected common ancestry and were not due to adaptive convergence. At the same time, trans-species evolution was also evidenced that the allelic diversity of the three MHC loci clearly pre-dated species divergence events according to the relaxed molecular clock. It may be the forces of balancing selection acting to maintain the high sequence variability and identical alleles in trans-specific manner at the MHC-I and DQB loci.

[Comparison of total body irradiation-cyclophosphamide versus busulphan-cyclophosphamide as conditioning regimens for myelogenous leukemia: a meta-analysis].

Total body irradiation combined with cyclophosphamide (TBI/CY) and busulphan combined with cyclophosphamide (BU/CY) are standard conditioning regimens in hematological stem cell transplantation for patients with myelogenous leukemia. This study was aimed to compare the therapeutic efficacy of TBI/CY and BU/CY as conditioning regiment for acute or chronic myelogenous leukemia. The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, CNKI, CBM (Chinese Bio-medicine Database) had been searched for all relevant articles (1999-2007). Comparative studies were carried out on clinical therapeutic effects of TBI/CY and BU/CY including stem cell engraftment, relapse, complications, transplant-related mortality, and disease-free survival. A meta-analysis was performed using Review Manager 4.2 software and funnel plot regression was adopted to assess the publication bias. The results indicated that 2149 articles in English and 46 articles in Chinese were got, and finally 9 clinical trials with total 3039 patients have been assessed. No significantly difference was found in engraftment failure and transplant-related mortality resulting from TBI/CY and BU/CY conditioning regimens, but the incidence of veno-occlusion of liver and hemorrhagic cystitis obviously increased in BU/CY group after transplantation, the acute GVHD, interstitial pneumonia and cataract significantly increased in TBI/CY group. The relapse rate of AML in TBI/CY group was lower than that in BU/CY group, and the rate of long-term disease-free survival of AML patients in TBI/CY group also significantly lower than that in BU/CY group, but the relapse rate of CML in TBI/CY group after transplantation was obviously higher than that in BU/CY group, but there was no difference in longterm disease-free survival rate between the two conditioning regimens mentioned above. It is concluded that the meta-analysis confirms different effects of TBI/CY and BU/CY regimens on myelogenous leukemia transplantation. This result is useful for physicians to select treatment regimens.

[Unrelated umbilical cord blood transplantation as a treatment for children with malignant leukemia].

OBJECTIVE: Unrelated umbilical cord blood has the clear benefits of rapid availability and a reduced stringency of requirement for HLA match. The aim of this study was to investigate the efficacy of unrelated umbilical cord blood transplantation (UCBT) in the treatment of malignant leukemia in children. METHODS: Six children with malignant leukemia, including three cases of acute lymphocyte leukemia [two high-risk patients and one standard-risk patient in complete remission (CR)], two juvenile myelomonocytic leukemia (one in CR and one in the accelerating stage), and one acute myeloblastic leukaemia (in CR), received a UCBT. The umbilical cord blood grafts were HLA-matched (n=1) or HLA-mismatched at 1 (n=1) or 2 (n=1) or 3 (n=3) loci. Busulfan/cyclophosphamide/antithymocyte globulin (ATG) or total body irradiation (TBI)/cyclophosphamide/ATG was involved in the myeloablative pretreatment regimen. The median infused donor nucleated cell was 8.51 x 10(7)/kg of recipient weight, and the CD34+ cell was 1.81 x 10(5)/kg of recipient weight. Cyclosporin, corticoid, mycophenolate mofetil and daclizumab were used for prophylaxis of acute graft versus host disease (GVHD). RESULTS: The time to reach an absolute neutrophil count of 0.5 x 10(9)/L ranged from 11 to 35 days (median: 13 days) and the time to reach a platelet count of 20 x 10(9)/L ranged from 27 to 68 days (median: 30 days) after transplantation, and the donors' hematopoietic stem cells were shown in these patients. Four patients developed grade I to III acute GVHD but responded to steroids and daclizumab. Chronic GVHD was not found during a 3-16-month follow-up. Four patients survived and did not relapse during the follow-up. CONCLUSIONS: Unrelated umbilical cord blood is an alternative source of hematopoietic stem cells for patients with leukemia. UCBT can tolerate 1-2 HLA mismatches. The incidence of acute GVHD is high in UCBT recipients.

[Early diagnosis of Kawasaki disease complicated by coronary artery lesions].

OBJECTIVE: To explore the possibility of early diagnosis of Kawasaki disease (KD) complicated by coronary artery lesions (CAL). METHODS: Medical records of 84 children with KD (2 months to 8 years of age) were reviewed retrospectively. Diagnosis of KD was based on current diagnostic criteria of KD. Laboratory examinations were performed for white blood cells (WBC), hemoglobin (HB), platelet counts (Plt), and C-reactive protein (CRP), along with electrocardiography (ECG) and echocardiography within 7 days after the onset of the disease. The Pearson correlation and multivariate analysis (logistic) were used for statistical analysis. RESULTS: During the first 7 days, clinical manifestations of the patients included fever (100%), conjunctivitis (71.46%), skin rash (66.7%), extremity change (54%), oral mucosa change (80%), and cervical lymphadenopathy (25%). Laboratory examinations revealed elevated WBC, CRP, and ECG (P<0.05, 0.05,0.01, respectively) in patients with CAL. Multivariate logistic regression analysis indicated that ECG positivity (P<0.01) and WBC increases (P<0.01) were independently correlated with CALs in acute KD. CONCLUSIONS: CRP (+), ECG (+), WBC count increase during the acute phase of KD are important indicators to predict CAL caused by KD.