Elevated CO2 altered the nano-ZnO-induced influence on bacterial and fungal composition in tomato (Solanum lycopersicum L.) rhizosphere soils.

To investigate whether elevated CO2 (eCO2) changes the influence of nanoparticles (NPs) on soil microbial communities and the mechanisms, various nano-ZnO (0, 100, 300, and 500 mg·kg-1) and CO2 concentrations (400 and 800 µmol·mol-1) were applied to tomato plants (Solanum lycopersicum L.) in growth chambers. Plant growth, soil biochemical properties, and rhizosphere soil microbial community composition were analyzed. In 500 mg·kg-1 nano-ZnO-treated soils, root Zn content was 58% higher, while total dry weight (TDW) was 39.8% lower under eCO2 than under atmospheric CO2 (aCO2). Compared with the control, the interaction of eCO2 and 300 mg·kg-1 nano-ZnO decreased and increased bacterial and fungal alpha diversities, respectively, which was caused by the direct effect of nano-ZnO (r = - 1.47, p < 0.01). Specifically, the bacterial OTUs decreased from 2691 to 2494, while fungal OTUs increased from 266 to 307, when 800-300 was compared with 400-0 treatment. eCO2 enhanced the influence of nano-ZnO on bacterial community structure, while only eCO2 significantly shaped fungal composition. In detail, nano-ZnO explained 32.4% of the bacterial variations, while the interaction of CO2 and nano-ZnO explained 47.9%. Betaproteobacteria, which are involved in C, N, and S cycling, and r-strategists, such as Alpha- and Gammaproteobacteria and Bacteroidetes, significantly decreased under 300 mg·kg-1 nano-ZnO, confirming reduced root secretions. In contrast, Alpha- and Gammaproteobacteria, Bacteroidetes, Chloroflexi, and Acidobacteria were enriched in 300 mg·kg-1 nano-ZnO under eCO2, suggesting greater adaptation to both nano-ZnO and eCO2. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States 2 (PICRUSt2) analysis demonstrated that bacterial functionality was unchanged under short-term nano-ZnO and eCO2 exposure. In conclusion, nano-ZnO significantly affected microbial diversities and the bacterial composition, and eCO2 intensified the damage of nano-ZnO, while the bacterial functionality was not changed in this study.

Mechanisms of Cancer-killing by Quercetin; A Review on Cell Death Mechanisms.

Cancer drug resistance has always been a serious issue regarding cancer research and therapy. Different cancers undergo different mutations, which may cause suppression of tumor suppressor genes, inhibition of apoptosis, stimulation of drug resistance mediators, and exhaustion of the immune system. The modulation of pro-death and survival-related mediators is an intriguing strategy for cancer therapy. Several nature-derived molecules, e.g., quercetin, have shown interesting properties against cancer through the modulation of apoptosis and autophagy mediators. Such molecules, e.g., quercetin, have been shown to stimulate apoptosis and other types of cell death pathways in cancers via the modulation of ROS metabolism. Quercetin may affect immune system function and trigger the expression and activity of tumor suppressor genes. Furthermore, it may suppress certain multidrug resistance mechanisms in cancer cells. This paper aims to review the effects of quercetin on various cell death mechanisms such as apoptosis, autophagic cell death, senescence, ferroptosis, and others.

Fungi Dominated the Incorporation of 13C-CO2 into Microbial Biomass in Tomato Rhizosphere Soil under Different CO2 Concentrations.

An elevated CO2 (eCO2) fumigation experiment was carried out to study the influence of various CO2 concentrations on microorganisms involved in the incorporation of root-derived C in greenhouse soil systems. In this study, 400 and 800 µmol·mol-1 CO2 fumigation treatments were conducted during tomato planting. Phospholipid fatty acid (PLFA) profiling based on the stable isotope probing (SIP) technique was applied to trace active microorganisms. The absolute total abundance of 13C-PLFAs was much higher under eCO2 treatment. Most of the 13C-CO2 was incorporated into the 13C-PLFAs 18:2ω6,9 (fungi), 16:0 (general PLFA), 18:1ω9c (Gram-negative bacteria, G-) and i17:0 (Gram-positive bacteria, G+) via rhizodeposition from tomato under ambient CO2 (aCO2) and eCO2 treatments, suggesting similar responses of active microorganisms to different CO2 treatments. However, the fungi (characterized by the 13C-PLFA 18:2ω6,9) played a much more dominant role in the incorporation of root-derived C under eCO2. Actinomycetes, marked by the 13C-PLFA 10-Me-18:0, occurred only on labeling day 15 under the eCO2 treatment, indicating that the actinomycetes fed on both soil organic carbon and fresh rhizodeposition. It was indicated that eCO2 significantly affected microbial biomass and microbial community structures involved in the incorporation of 13C-CO2 via tomato root secretions, as supported by Adonis analysis and the Mantel test.

A favorable inductive remission rate for decitabine combined with chemotherapy as a first course in <60-year-old acute myeloid leukemia patients with myelodysplasia syndrome features.

In acute myeloid leukemia (AML), myelodysplasia-related changes contribute to a poor prognosis. This retrospective, propensity score-matched study analyzed 108 newly diagnosed AML patients with features of myelodysplasia syndrome (MDS) (aged 14-60 years) from 2014 to 2018, who received either idarubicin and cytarabine (IA) or decitabine, idarubicin and cytarabine (DAC+IA), and compared efficacy and toxicity between the two regimens. After propensity score matching, there were 54 patients in each group. The rate of complete remission (CR) was higher in the DAC+IA group than in the IA group (85.2% vs 68.5%, P = .040) after the first course, and toxicities were comparable in both groups. Multivariate analysis indicated that the combination with DAC was independent factor for CR rate after the first induction therapy (OR = 2.978, 95% CI:1.090-8.137, P = .033). Subgroup analysis showed a CR advantage for DAC+IA (vs IA) for patients of intermediate-high risk status according to National Comprehensive Cancer Network prognostic stratification. In conclusion, DAC+IA is therefore offered as a new induction choice for newly diagnosed AML patients with features of MDS, aged <60 years old, especially in intermediate-high risk status.

Value of systemic PET/CT in the diagnosis and differential diagnosis of aplastic anemia.

The aim of the present study was to investigate the value of systemic [18F]fluorodeoxyglucose positron emission tomography (PET)/computed tomography (CT) in the diagnosis and differential diagnosis of aplastic anemia (AA). Systemic PET/CT imaging results of 24 patients diagnosed with AA in The First Affiliated Hospital of Sun Yat-Sen University between May 2011 and August 2014 were retrospectively analyzed and compared with results from healthy individuals and patients with acute leukemia (AL) or myelodysplastic syndrome (MDS) in the same period to summarize the PET/CT characteristics of patients with AA. Systemic PET/CT manifestations of the 24 patients with AA were classified into three types: Normal bone marrow metabolism, hypometabolism and hypometabolism complicated by focal hyperproliferation. Focal hyperproliferation was frequently identified in the vertebral body, breast bones and iliac bones. Bone marrow maximum standardized uptake values (SUV) of AA were associated, to certain extents, with the degree of proliferation and the bone marrow T/B cell ratio. The overall bone marrow SUV of AA were lower compared with those of healthy individuals and AL or patients with MDS, indicating hypometabolism. Considering the T/B cell ratio, systemic PET/CT manifestations of patients with AA are able to predict treatment responses to certain degrees. Systemic PET/CT is highly valuable in the diagnosis and differential diagnosis of AA, and may also indicate treatment responses.

SH3BGRL as a novel prognostic biomarker is down-regulated in acute myeloid leukemia.

Phosphatase PRL-3 expression is positively associated to acute myeloid leukemia (AML) progression and drug resistance. SH3-domain-binding glutamic acid-rich protein-like protein (SH3BGRL), a downstream effector of PRL-3, plays a tumor suppressive role in solid tumors, but it remains elusive in AML. Here, we followed up and validated the relevance of SH3BGRL expression to AML progression in 116 cases. Results showed that SH3BGRL is down-regulated in 62.37% AML cases with poor prognosis. Cases with positive response to therapy accompanies with SH3GRL expression restoration. Mechanistically, SH3BGRL down-regulation promotes AML cell cycle progression and enhances the anti-apoptotic ability to drug cytotoxicity. While ectopic SH3BGRL blocks AML cell cycle and proliferation to sensitize them to therapeutic drugs via apoptosis. Xenograft assays further confirmed the suppressive role of SH3BGRL in leukemogenesis. Thus, our results demonstrated that SH3BGRL is a novel crucial player in AML progression and could be both a potential diagnostic and prognostic marker.

[Prostaglandin E2 Receptor 4 Agonist Promotes Human CD34+ Cell Proliferation in vitro by Activating Wnt/ß-Catenin Signaling Pathway].

OBJECTIVE: To investigate the potential signaling pathway that regulates the proliferation of human CD34+ cells stimulated by prostaglandin E2 receptor 4 agonist (EP4A) in vitro. METHODS: Twenty samples of peripheral blood containing stem cells were collected from the G-CSF mobilized healthy donors in our department of hematology. Human CD34+ cells were isolated by magnetic activated cell sorting (MACS) microbeads kit. The Cell Counting Kit-8 (CCK8) assay was used to determine the optimal concentration and time of EP4A to promote human CD34+ cell proliferation in vitro. Under the optimal condition, quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect mRNA level of ß-catenin, and Western blot was used to assay protein expression of ß-catenin and P-GSK-3ß in human CD34+ cells treated with EP4A. RESULTS: Culturing with 10 µmol/L EP4A for 72 h, it was found that EP4A promoted human CD34+ cell proliferation significantly, and the proliferation rate of human CD34+ cells was 1.36 times higher than that of the control(P=0.002). Under the optimal condition, it was also found that EP4A enhanced the ß-catenin expression at both mRNA and protein levels, and up-regulated phosphorylation of GSK-3ß in human CD34+ cells, but these effects could be inhibited by the EP4A antagonist EP4AA. CONCLUSION: EP4A can enhance human CD34+ cell proliferation in vitro by activating Wnt/ß-catenin signaling pathway.

Chinese Erdheim-Chester disease: clinical-pathology-PET/CT updates.

UNLABELLED: Erdheim-Chester disease (ECD), one type of systemic non-Langerhans cell histiocytosis, has been rarely seen and is characterized by the accumulation of foamy CD68+CD1a- histiocytes. We reported a case of ECD and reviewed the clinical features of 13 cases of ECD reported so far in China. A 53-year-old male was diagnosed with central diabetes insipidus in March 2014, followed by fever, splenomegaly and anemia in July 2014. His initial pituitary magnetic resonance imaging (MRI) revealed the absence of high signal at T1-weighted image in posterior pituitary without any lesion. A further positron emission tomography/computer tomography (PET/CT) images showed elevated metabolic activity of (18)F-2-fluro-D-deoxy-glucose (FDG) and low (13)N-NH3 uptake in the posterior pituitary, and multi-organ involvement. Biopsy at right femur lesion revealed that granulomatous infiltration of foamy histiocytes and Touton giant cells surrounded by fibrosis tissues. Immunohistochemistry stain was positive for CD68, negative for CD207/Langerin and S-100. The diagnosis of ECD was confirmed and the treatment with pegylated interferon was effective. ECD was a possible immune-related disorder concluding from the IgG4 immunohistochemistry results. We summarized the pathological manifestations for ECD and its differential diagnosis from Langerhans cell histiocytosis (LCH) and Rosai-Dorfman disease (RDD). ECD should be considered by both pathologists and clinicians in the differential diagnosis when central diabetes insipidus is accompanied with multi-organ involvement, especially skeletal system involvement, or recurrent fever. LEARNING POINTS: ECD should be considered when central diabetes insipidus is accompanied with multisystem involvement, especially symmetric/asymmetric bone lesions, or recurrent fever.PET/CT scanning was helpful for locating pituitary lesion, discovering multiple system involvement and indicating the biopsy sites.Conducting proper immunohistochemistry stains was important for diagnosing ECD. ECD might be correlated with immune disorder.

[Bortezomib-based induction therapy followed by autologous hematopoietic stem cell transplantation in multiple myeloma].

OBJECTIVE: To evaluate the short-term and long-term effect of novel agents followed by autologous hematopoietic stem cell (ASCT) in Chinese multiple myeloma(MM) patients in order to find out the optimal therapeutic regimen for transplant-eligible patients. METHODS: Clinical data of 100 active MM patients receiving bortezomib-based induction regimens followed by high-dose melphalan and ASCT were retrospectively analyzed from June 1, 2006 to January 30, 2014. RESULTS: The overall response rates(ORR) after induction therapy, transplantation and consolidation and maintenance therapy were respectively 90.0%, 97.0%, and 98.9%. The median progress free survival(PFS) was 42.3 months. The median overall survival(OS) was not reached. The cumulative near complete response (nCR)+complete respanse(CR) rate was no longer improved after 4 cycles of induction therapy for non-light chain type MM and two cycles for light-chain type. In newly-diagnosed light-chain type MM patients, the cumulative nCR+CR rate after 4 cycles of bortezomib plus dexamethasone (VD) regimen was similar to that of bortezomib, doxorubicin and dexamethasone (PAD). While for those non-light-chain types, three drug-based regimen was better than two drug-based. PFS of patients receiving early ASCT was longer than that of late ASCT (50.7 months vs 26.6 months, P = 0.023) . PFS in patients receiving autologous bone marrow stem cell transplantation (ABMSCT) was longer than that of autologous peripheral blood stem cell transplantation (APBSCT) (NA vs 36.1 months, P = 0.049) . Maintenance therapy was beneficial regardless of the response rate after ASCT. Patients with CR at any time during the therapy had longer PFS than those with nCR. CONCLUSIONS: Bortezomib-based therapy followed by ASCT is the first line therapy for transplant-eligible MM patients. Patients with different types of M protein require different induction regimens. Maintenance is beneficial to patients after ASCT, no matter whether a CR is reached or not. Patients with CR after induction or ASCT tend to have longer survival.

[Clinical significance of abnormal protein bands in multiple myeloma treated with bortezomib-based induction regimen and autologous stem cell transplantation].

OBJECTIVE: To study the clinical significance of abnormal protein bands (APB) in multiple myeloma (MM) patients treated with bortezomib-based induction regimen and autologous stem cell transplantation (ASCT). METHODS: Sixty-eight MM patients submitted to bortezomib-based induction therapy and ASCT from January 2007 to July 2012 were retrospectively studied. Monoclonal protein was detected by immunofixation electrophoresis (IFE). RESULTS: Of all 68 patients, 33 (48.5%) patients had APB. At the first emergence of an APB, two patients with light chain type achieved CR and before transplantation, and thirty-one patients were after transplantation with median time of 104 (ranged 33-404) days. The median duration of APB appearance was 105 (ranged 35-801) days. Patients who developed APB compared with those without APB, had a significantly higher CR plus very good partial response (VGPR) rates (100.0% vs 85.7%%, P=0.017) and CR rates (87.9% vs 62.9%) (P=0.03). There were no significant differences in gender, age, HGB, ALB, ß2-microglobulin, M protein type, Durie-Salmon and ISS stages, the case number of first line or second line treatment, induction courses of bortezomib-based regimen, and the mode of ASCT. With a median follow-up of 33.4 (ranged 7.0-71.7) months, patients with APB tended to have a longer overall survival (OS) versus non-APB patients, although no significant difference obtained (P＞0.05). Among APB patients, OS was longer in patients whose appearance of APB occurred ＜6 months after transplantation than those ≥ 6 months, but the significant difference was not obtained yet (P＞0.05). CONCLUSIONS: Patients who developed APB had a significantly better response to bortezomib-based induction regimen followed ASCT. APB emergence has a good prognostic significance.

[Effects of killer immunoglobulin-like receptor and human leukocyte antigen class I ligand on the prognosis of related donor hematopoietic stem cell transplantation].

OBJECTIVE: To study the genotype distribution and the effects of killer immunoglobulin-like receptors (KIR) and human leukocyte antigen (HLA) class I ligand on related donor hematopoietic stem cell transplantation (HSCT). METHODS: The genotypes of donor/recipient HLA-Cw and donor KIR were determined by polymerase chain reaction-sequence specific primer (PCR-SSP) in 87 cases of related donor HSCT (40 cases were haploidentical HSCT, and the remaining 47 cases were HLA-identical sibling HSCT). RESULTS: All the donors possessed KIR2DL1, 2DL2/L3, 2DL4, 3DL2, and 3DL3, and 96.6% of donors possessed 3DL1. The rate of activating KIRs varied. 97.7% of the recipients expressed C1, while the rates of C2, Bw4, and HLA-A3/A11 were different. In haploidentical HSCT, KIR-HLA-mismatched group included 34 cases and the matched group included 6 cases. HLA-HLA-mismatched group included 31 cases and the matched group included 9 cases. In matched sibling donor HSCT, KIR-HLA-mismatched group included 42 cases and the matched group included 5 cases. KIR-HLA-mismatched group had higher 2-year disease-free survival (DFS) rate compared with KIR-HLA-matched group [ (71.5 +/- 6.5 ) % vs. (50.0 +/- 10.7)%, P < 0.05]. CONCLUSIONS: The rate of activating KIR is lower than inhibitory KIRs. Inhibitory KIR2DL1, 3DL1, and 3DL2 may play key roles in the natural killer cell alloreactivity. The DFS rate is higher in KIR-HLA-mismatched group than in KIR-HLA-matched group in related donor HSCT.

[Osteoclast differentiation regulated by receptor activator of nuclear factor kappaB probably through a novel signaling pathway].

This study was aimed to investigate the signaling pathways regulating osteoclast (OC) differentiation by receptor activator of nuclear factor kappa (RANK) under physiological condition so as to provide some theoretical basis for clarifying mechanism of bone destruction in multiple myeloma. A mutant TNFR(1)/RANK(2) (named RANK-Mu) chimera consisting of tumor necrosis factor receptor 1 (TNFR(1)) and RANK intramembrane domain was constructed by using deletion mutation for deleting IVVY amino acids in RANK intramembrane domain in accordance with (535-)IVVY(-538) as specific domain regulating OC differentiation by RANK. The RANK-Mu and TNFR(1)/RANK chimera without mutation (RANK-WT) were packaged by using plat E cell line to produce the retrovirus, which were transfected into bone marrow macrophages (BMMs) of TNFR(1)/TNFR(2) double knockout mice. After stimulation of these transfected BMMs with TNF-alpha, the differentiation of BMMs into OCs were observed, meanwhile the phosphorylation of NF-kappab, JNK, p38 and ERK was detected by Western blot after stimulation of these BMMs with TNF-alpha. The results showed that BMMs transfected with RANK-WT could be differentiated into OCs and phosphorylation of NF-kappaB, JNK, P38 and ERK were activated at 5 - 10 minutes after being stimulated by TNFalpha. BMMs transfected with RANK-Mu could not be differentiated into OCs, but phosphorylation of NF-kappaB, JNK, P38 and ERK were activated also. It is concluded that RANK regulates osteoclast differentiation probably not through 4 typical signaling pathways, named as NF-kappaB, JNK, P38 and ERK, in this process other new signaling pathways maybe participate.

[The effects and safety of bortezomib combined with dexamethasone in the treatment of primary systemic amyloidosis].

OBJECTIVE: To evaluate the effects and safety of the regimen of bortezomib combined with dexamethasone (VD) in the treatment of primary systemic (AL) amyloidosis. METHODS: Five newly diagnosed AL amyloidosis patients confirmed by renal biopsy with a median of 3 organs involved (3 to 5 organs) were treated by VD regimen for 3 (1-4) cycles. RESULTS: Among 3 evaluable patients, 1 was in stable condition and 2 had hematologic response (partial remission and complete remission) and organ function improvement. Hematologic responses were rapid (median 1.5 cycles) and median time to organ response was 2 cycles. Three cases were survived and the periods of follow up were 5, 4 and 4 months respectively. The other 2 died 2 and 14 months after diagnosis. The side effects were asthenia, diarrhea, constipation, edema aggravation and fever, all of which were in I grade. No treatment associating death was found. CONCLUSION: VD regimen might be an efficient, rapid effective and safe regimen in the treatment of AL amyloidosis.

[Efficacy of bortezomib combined dexamethasone in 24 patients with multiple myeloma].

BACKGROUND & OBJECTIVE: Bortezomib, a potent and reversible proteasome inhibitor, induces apoptosis of myeloma cells, resulting in durable responses in patients with multiple myeloma (MM). This study was to explore the medical effects and side effects of bortezomib combined dexamethasone in treating newly diagnosed and relapsed or refractory MM, and evaluate the safety of this regimen in the patients with renal impairment. METHODS: Twenty-four MM patients were treated with bortezomib and dexamethasone in a 21-day cycle. The patients received a median of 3 cycles (range, 1-8 cycles) of the treatment. Response to bortezomib was evaluated according to the criteria of the European Group for Blood and Marrow Transplantation (EBMT); adverse events were graded according to the National Cancer Institute Common Toxicity Criteria. RESULTS: During the follow-up with a median of 4 months, 19 (79.2%) patients responded to the treatment. The complete remission (CR) rate was significantly higher in the patients of light-chain type than in those of non-light-chain type (57.1% vs. 5.9%, P=0.014). The response rates of the patients with and without renal impairment were similar (100% vs. 70.6%, P=0.272), and the renal functions were ameliorated in the patients with renal impairment during chemotherapy. Grade III-IV adverse events, including leucocytopenia (8.3%), thrombocytopenia (33.3%), diarrhea (8.3%) and debility (4.2%), could be relieved by symptomatic treatment or delayed chemotherapy. CONCLUSIONS: The combination of bortezomib and dexamethasone shows obvious effects on MM, especially in the patients with light-chain type. The adverse events can be tolerant in most patients, and this regimen is also safe in the patients with renal impairment.

[Impact of donor KIR2DS5 genotype on outcome following haploidentical hematopoietic stem cell transplantation].

The aim of this study was to evaluate the impact of donor killer cell immunoglobulin-like receptor (KIR) and recipient HLA genotypes on outcome following haploidentical hematopoietic stem cell transplantation (HSCT). 26 patients with hematologic diseases received non T-cell-depleted (TCD) in vitro transplant from haploidentical donor. Donor/recipient HLA and donor KIR genotypes were determined by polymerase chain reaction-sequence-specific primer (PCR-SSP). Donor/recipient KIR/HLA subgroup was assessed by donors KIR and recipients HLA-Bw4, Cw1 group and Cw2 group alleles. Hematopoietic reconstitution, incidence of graft versus host disease (GVHD), disease-free survival (DFS), infection and transplant-related mortality (TRM) were analyzed between every two groups. The influence of donor activating KIR on outcome following haploidentical HSCT also has been studied. The results showed that hematopoietic reconstitution, incidence of GVHD, DFS, infection and TRM were not significantly different between every two groups (p>0.05). There were 4 cases of severe GVHD in C2 mismatched group. The donor activating KIR2DS5 positive group had higher 2-year DFS compared with the negative group [(85.7+/-13.2)% vs (31.2+/-12.8)%, p<0.05]. It is concluded that KIR/HLA genotypes between donor and recipient influence the outcome following haploidentical HSCT. Donor activating KIR2DS5 may improve DFS in non TCD haploidentical HSCT.

[Role of alloreactive natural killer cell in mouse MHC haploidentical bone marrow transplantation].

OBJECTIVE: To study the effect of alloreactive natural killer (NK) cells used in conditioning regimen on elimination of recipient-type T cell and granulocyte, reconstitution of hematopoiesis, engraftment and graft-versus-host disease (GVHD) in murine major histocompatibility complex (MHC) haploidentical bone marrow transplantation (BMT). METHODS: The murine model of MHC haploidentical BMT was established by using (C57BL/6 x BALB/c) BCF(1) (H-2(d/b)) mouse as the donor, and BALB/c (H-2(d)) mouse as the recipient. Recipient mice were divided into 8.5 Gy control group and 7, 6 and 5 Gy experimental groups according to different irradiation dose and different kinds of NK cell treatment. The control group was further subdivided into untreated and BMT groups, while each experimental group was subdivided respectively into untreated group, BMT group, non-allo-reactive NK cells (non-allo NK) group and alloreactive NK cells (allo NK) group. The effect of adding alloreactive NK cell to conditioning regimen was assessed by peripheral white blood cell and platelet counts, recipient type H-2(d+) T cells and granulocytes counts, expression of H-2(d/b+) cells and pathohistological examination. RESULTS: Survival time was (6.00 +/- 0.82) days for 8.5 Gy untreated group, and beyond 60 days for all the other groups. No clinical and histopathological evidence of GVHD was observed in all the groups. The reconstitution of hematopoiesis was faster in allo NK groups than in other groups (P < 0.05). On day 1 after BMT, in allo NK groups with different irradiation dose, bone marrow and spleen recipient type H-2(d+) granulocytes and T cells were significantly decreased compared with identical BMT groups and non-allo NK groups (P < 0.05). The engraftment rates of H-2(d/b+) cells were significantly higher in 7, 6 and 5 Gy allo NK groups than in identical BMT groups and non-allo NK groups (P < 0.05, respectively). CONCLUSIONS: In mouse MHC haploidentical BMT, alloreactive NK cell can eliminate recipient-type T cell and granulocyte, promote reconstitution of hematopoiesis, enhance engraftment while not induce GVHD.

[Effects of mesenchymal stem cells on expansion potential and adhesion molecules expression of cord blood CD34+ cells].

OBJECTIVE: To explore the effects of bone marrow mesenchymal stem cells (MSCs) on in vitro expansion potential, the adherent molecules expression of cord blood (CB) CD34(+) cells. METHODS: MSCs were obtained from human bone marrow and their differentiation function and phenotype were identified. CB CD34(+) cells were expanded in culture systems with or without MSC layer. Hematopoietic progenitor cells and adhesion molecules expression were assessed by semisolid culture assay and flow cytometry. RESULTS: Thy-1, SH2, SB10, CD44, CD13, CD49e and CD29 were highly expressed on MSCs with no expressions of CD34, CD45, HLA-DR, CD14 and CD31. The MSCs could differentiate into adipocytes and osteoblasts under specific induction conditions. After culturing on MSCs layer with supplement of cytokines for 8 days, the absolute numbers of nuclear cells, CD34(+), CD34(+)CD38(-), CD34(+)CD62L(+) cells and CFU-Cs were increased by 145.57 +/- 17.89, 37.47 +/- 13.78, 69.78 +/- 50.07, 10.74 +/- 5.89 and 20.73 +/- 5.54-folds, respectively, being significantly higher than that cultured with cytokines alone. The expression of ALCAM, VLA-alpha4, VLA-alpha5, VLA-beta1, HCAM, PECAM and LFA-1 on CD34(+) cells remained unaffected. The expressions of ICAM-1 and L-selectin were downregulated during expansion, while the absolute numbers of CD34(+)CD62L(+) and CD34(+)CD54(+) cells were increased. CONCLUSIONS: MSCs layer improves expansion of CB CD34(+) cells while inhibiting their differentiation and retaining their homing ability.

[Comparative study on various subpopulations in mesenchymal stem cells of adult bone marrow].

To explore the difference of biological characteristics between two subpopulations of adult bone marrow mesenchymal stem cells (MSC), this study was designed to observe the morphological feature and immunophenotype of the adult MSC in the ex vivo culture, the mononuclear cells isolated from normal adult bone marrow were cultured in DMEM with 10% fetal bovine serum. Cell morphology, immunophenotype and cell cycle of two different subgroups were investigated. Cells from 80% confluence were passed through a 10 microm filter, then the fillered cells were cultured in the semisolid methylcellulose medium. The results showed that (1) two different subpopulations were observed in the ex vivo culture. The fibro-like cell was called mature MSC (mMSC) and the smaller round cell was defined rapidly as MSC self-renewing cells (RS cells); (2) the average proportion of cells in G(0)/G(1) of RS cells was approximately 99%, but that of mMSCs was 90%; (3) both of the two populations were negative on the lineage-committed antigen (such as CD34, CD45, CD3, CD19, CD33, HLA-DR, CD38), while positive on the expression of CD90, CD105, C166, CD29, CD44, CD49e, CD54, CD13. However, the expression of these antigens on RS cells was weaker than that on mMSC, but CD117 and KDR were higher expressed when compared with the mMSC; (4) after 4 to 5 week semisolid culture, no hematopoietic progenitor cell colonies were observed. It is concluded that adult MSCs are heterogeneous in that distinct morphological populations exist. The RS cells appear to be the more primitive with greater potential for self-renewal and multilineage differentiation.

[T-bet gene expression in acute graft versus host disease].

OBJECTIVE: To study the role of T-bet [a T helper 1 (Th1) lymphocyte transcription factor] gene expression in predicting acute graft-versus-host disease (aGVHD) and evaluate the correlation between T-bet gene and aGVHD. METHODS: Twenty patients who underwent allogeneic stem cell transplantation (allo. HSCT) entered this study. The expression of T-bet gene was examined with reverse transcription (RT)-PCR in bone marrow samples collected from patients on the day before conditioning, and day 0, day 14, day 28, and day 42 after HSCT. RESULTS: The expression level of T-bet in patients developed aGVHD was increased compared with that before conditioning (P = 0.043). The incidence of aGVHD was 91.7% in patients whose T-bet expression level was increased on day 14 after transplant while was 12.5% in those whose T-bet gene expression level was not increased on that day (P < 0.001). CONCLUSION: Patients with increased expression levels of T-bet after allo-HSCT may have an increased possibility to develop aGVHD. T-bet expression level may serve as an advisable guide to the clinician in predicting aGVHD and monitoring treatment.