All-optically controllable nanoparticle random laser in a well-aligned laser-dye-doped liquid crystal.

This study reports for the first time an all-optically controllable nanoparticle random laser (NPRL) in a well-aligned laser-dye-doped liquid crystal (LDDLC) cell added with NPs and azo-dyes. Experimental results display that the NPRL can be obtained when the pumped energy exceeds the energy threshold (~3.5 µJ/pulse). The occurrence of the NPRL is attributable to the enhancement of the fluorescence by the multi-scattering events of the fluorescence photons from the randomly distributed NPs in the diffusion rout of the well-aligned LDDLC cell. In addition, the lasing intensity of the NPRL can decrease with increasing irradiation time of one UV beam. Continuing irradiation of one green beam following the UV illumination can increasingly recover the lasing intensity of the NPRL. The all-optically reversible controllability of the NPRL is basically attributed to the successive UV-beam-induced increase and green-beam-induced decrease in the randomness of the LDDLC via their interactions with the curved cis and rod-like trans isomers after the accumulation of the trans→cis and cis→trans back isomerizations of the azo-dyes, respectively. The former and latter mechanisms can decrease and increase the laser-dye's absorption and thus the induced spontaneous emission, respectively. These consequences can decrease and increase the lasing intensity, or equivalently, increase and decrease the energy threshold for the occurrence of the NPRL, respectively.

Performance evolution of color cone lasing emissions in dye-doped cholesteric liquid crystals at different fabrication conditions.

This work investigates the performance evolution of color cone lasing emissions (CCLEs) based on dye-doped cholesteric liquid crystal (DDCLC) cells at different fabrication conditions. Experimental results show that the energy threshold (E(th)) and relative slope efficiency (η(s)) of the lasing signal emitted at each cone angle (0°-35°) in the CCLE decreases and increases, respectively, when the waiting time in a homogenously rubbed aligned DDCLC cell is increased from 0 hr to 216 hr (9 days). This result occurs because defect lines gradually shrink with the anchoring of the surface alignment when the waiting time is increased. Hence, the scattering loss decreases, and the dwelling time of the fluorescence photons in the resonator increases, which in turn enhances the CCLE performance. With the aligned cell given the pretreatment of a rapid annealing processing (RAP), the waiting time for obtaining an optimum CCLE can markedly be reduced sixfold. The surface alignment of the DDCLC cell also plays a necessary role in generating the CCLE. This work provides an insight into the temporal evolution of the performance for the CCLE laser and offers a method (RAP) of significantly speeding up the formation of a CCLE laser with optimum performance.

Myopization factors affecting urban elementary school students in Taiwan.

PURPOSE: To investigate factors that may contribute to the myopization of urban elementary school students in Taiwan. METHODS: Grades 1 to 6 students of the same racial background (n = 1894; mean age, 6.3-11.3 years) in three schools, located in Tamsui, Taichung, and Tainan, were refracted to obtain the best corrected visual acuity. The refractive power needed for best corrected visual acuity was used for subsequent statistical analysis. On behalf of their children, parents also completed a questionnaire on six categories of potential myopization variables. Correlation between these variables and the increase or decrease in the refractive error was assessed. The predictive value of each variable was also calculated based on linear regression analysis. RESULTS: The overall mean refractive error in grades 1 to 6 was -0.37, -0.68, -1.33, -1.60, -1.90, and -2.51 D, respectively. The prevalence of myopia (-1.00 D or more minus) showed a significant difference between grades 2 and 3 and, again, between grades 5 and 6. In addition, 20 potential modulating factors were evaluated; 65.9% of the change in the refractive error could be explained by four: (1) lag in optimal correction, defined as a -1.00-D deficit between new refractive error and current optical correction; (2) outdoor spectacle wear; (3) spectacles for different working distances; and (4) hours spent on reading and writing on weekdays. In contrast, outdoor time and the intake frequency of 36 food items both held very low predictive values of 0.2% and 2.5%, respectively. CONCLUSIONS: Each variable associated with the refractive error has a different predictive value, either positive or negative. Ultimately, the interplay of these variables decides the outcome of the pattern and the degree of school myopia.

Negative regulation of cyclin D3 expression by transcription factor c-Ets1 in umbilical cord hematopoietic cells.

AIM: To investigate the role of transcription factor c-Ets1 in cyclin D3 expression and its effects on the proliferation of umbilical cord hematopoietic cells. METHODS: Cyclin D3 promoter deletion constructs were generated and transfected into CD34(+) cells. Dual luciferase reporter assays and TFSEARCH software were used to identify negative regulatory domains and to predict putative transcription factors involved in cyclin D3 downregulation. Expression of c-Ets1 in CD34(+) cells was detected using electrophoretic mobility shift and super shift assays. Point mutants of c-Ets1 binding sites were constructed. The wild-type c-Ets1 and the mutant promoter constructs were co-transfected into CD34(+) cells to determine the promoter activity. The impact of c-Ets1 expression on the proliferation of CD34(+) cells was assessed using MTT assay. RESULTS: Nine cyclin D3 promoter deletion constructs were generated. A negative regulatory domain containing c-Ets1 binding sites was identified between -439 bp and -362 bp. Transfection of the promoter deletion constructs containing mutant c-Ets1 binding sites enhanced cyclin D3 promoter activity. However, the opposite results were observed when CD34(+) cells were co-transfected with wildtype c-Ets1 and its promoter deletion constructs. The overexpression of c-Ets1 could suppress cyclin D3 mRNA and protein levels. In addition, it inhibits the proliferation of CD34(+) cells. CONCLUSION: c-Ets1 functions as a negative transcription factor, down-regulating the expression of cyclin D3, which leads to inhibition of CD34(+) cell proliferation.

[Biological characteristics of hematopoietic progenitor cells at different stages of hematopoietic development].

The aim of the present paper is to better understand the mechanism of hematopoietic development through studying the biological characteristics of hematopoietic progenitor cells at different stages of development. Firstly, the c-kit expression levels of the mononuclear cells from murine embryonic aorta-gonad-mesonephros (AGM) region at embryonic day (E)10.5 and E11.5, fetal liver (FL) at E12.5, E14.5, E16.5, E18 and bone marrow (BM) were assayed with fluorescence activated cell sorting (FACS). Secondly, hematopoietic progenitor cells derived from AGM at E10.5, FL at E14.5 and BM were isolated by using c-kit microbeads. Isolated c-kit(+) population cells from AGM, FL and BM were then co-cultured with E14.5 FL-derived stromal cells in transwell co-culture system in vitro. After 3, 7, 10 days of co-culture, numerous floating cells were generated. The floating cells generated in transwell inserts were collected for FACS cell count, migration activity detection and colony forming unit (CFU) formation assay. The results showed that the c-kit was highly expressed in E10.5 AGM, with the percentage of c-kit(+) cells declining during AGM development. c-kit expression was highly expressed again in E12.5 FL, declining along with the progressive development of the FL region. Co-cultured with FL-derived stromal cells, E10.5 AGM-derived c-kit(+) cells produced the highest number of hematopoietic cells, while BM-derived c-kit(+) cells produced the lowest number of hematopoietic cells. Compared with E10.5 AGM-derived c-kit(+) cells, E14.5 FL- and BM- derived c-kit(+) cells inclined to differentiate after 7 to 10 days of culture in vitro. E10.5 AGM and E14.5 FL-derived c-kit(+) cells exhibited a higher migration activity than BM-derived c-kit(+) cells. Moreover, E10.5 AGM-derived c-kit(+) cells showed a higher ability to form mixed colony-forming unit (CFU-Mix) colony. In conclusion, compared with FL- and BM-derived c-kit(+) cells, E10.5 AGM-derived c-kit(+) hematopoietic progenitor cells exhibit better proliferation, migration potential, and have a higher ability to maintain the undifferentiation state in vitro, providing an insight into their clinical manipulation.

Screening of aplastic anaemia-related genes in bone marrow CD4+ T cells by suppressive subtractive hybridization.

BACKGROUND: CD4(+) T cells play a crucial role in the pathogenesis of aplastic anaemia. However, the mechanisms of over-proliferation, activation, infiltration of bone marrow and damage to haematopoietic cells of CD4(+) T cells in aplastic anaemia are unclear. Therefore, we screened differentially expressed genes of bone marrow CD4(+) T cells of aplastic anaemia patients and normal donors by suppressive subtractive hybridization to investigate the pathogenesis of aplastic anaemia. METHODS: The bone marrow mononuclear cells of a first visit aplastic anaemia patient and a healthy donor of the same age and sex were isolated using lymphocyte separating medium by density gradient centrifugation. With the patients as "tester" and donor as "driver", their CD4(+) T cells were separated with magnetic bead sorting and a cDNA library established by suppressive subtractive hybridization. Then 15 of the resulting subtracted cDNA clones were randomly selected for DNA sequencing and homological analysis. With semiquantitative RT-PCR, bone marrow samples from 20 patients with aplastic anaemia and 20 healthy donors assessed the expression levels of differentially expressed genes from SSH library. RESULTS: PCR detected 89 clones in the library containing an inserted fragment of 100 bp to 700 bp. Among 15 sequenced clones, 12 were known genes including 3 repeated genes. Compared with normal donors, there were 9/12 genes over-expressed in bone marrow CD4(+) T cells of patients with aplastic anaemia. The effects of these genes included protein synthesis, biology oxidation, signal transduction, proliferative regulation and cell migration. Not all these genes had been reported in the mechanisms of haematopoietic damage mediated by CD4(+) T cells in aplastic anaemia. CONCLUSIONS: Screening and cloning genes, which regulate functions of CD4(+) T cells, are helpful in elucidating the mechanisms of over proliferation, activation, infiltrating bone marrow and damaging haematopoietic cells of CD4(+) T cells in aplastic anaemia.

[Mechanism of radiation induced premature senescence of bone marrow stromal cells: experiment with murine bone marrow stromal cells].

OBJECTIVE: To investigate the mechanism of radiation induced premature senescence of bone marrow stromal cells induced by gamma-radiation. METHODS: Bone marrow stromal cells were isolated from the bones of mice, cultured, and divided into 2 groups: control group and irradiation group. The cells of the irradiation group were exposed to 60Co gamma-rays of the dose of 8.0 Gy. 24 h, 72 h, 1 week, and 2 weeks after irradiation MTT method was used to test the proliferation of the cells, Giemsa staining was used to observe the morphology, the percentage of cells positive in beta-galactosidase (SA-beta-Gal), a senescence associated biomarker, was detected by cytochemistry, and RT-PCR was used to detect the mRNA expression of p21(Cip1/Waf1) and p53 gene, both associated with senescence. One week after the irradiation flow cytometry was used to analyze the cell cycle distribution. RESULTS: Characteristics of mature senescence were seen in the cells of the irradiation group. One week after the irradiation the percentage of G0/G1 of the irradiation group was 89.83% +/- 0.05%, significantly higher than that of the control group (66.95% +/- 0.36%, P < 0.01). 24 h, 72 h, 1 week, and 2 weeks after irradiation the percentages of SA-beta-gal positive cells in the irradiation group were 20.33% +/- 0.03%, 34.33% +/- 0.03%, 86.33% +/- 0.02%, and 95.67% +/- 0.02% respectively, significantly higher than those of the control group (2.33% +/- 0.006%, 14.33% +/- 0.02%, 24.67% +/- 0.02%, and 45.00% +/- 0.02% respectively, all P < 0.01). The mRNA expression of p53 and p21(Cip1/Waf1) mRNA expressions in the irradiation group increased 24 h after the irradiation and lasted for two weeks. CONCLUSION: Gamma-radiation induces changes of premature senescence in bone marrow stromal cells in which p53-p21(Cip1/Waf1) manner pathways may play an important role.

Expansive effects of aorta-gonad-mesonephros-derived stromal cells on hematopoietic stem cells from embryonic stem cells.

BACKGROUND: Hematopoietic stem cells (HSCs) give rise to all blood and immune cells and are used in clinical transplantation protocols to treat a wide variety of refractory diseases, but the amplification of HSCs has been difficult to achieve in vitro. In the present study, the expansive effects of aorta-gonad-mesonephros (AGM) region derived stromal cells on HSCs were explored, attempting to improve the efficiency of HSC transplantation in clinical practice. METHODS: The murine stromal cells were isolated from the AGM region of 12 days postcoitum (dpc) murine embryos and bone marrow (BM) of 6 weeks old mice, respectively. After identification with flow cytometry and immunocytochemistry, the stromal cells were co-cultured with ESCs-derived, cytokines-induced HSCs. The maintenance and expansion of ESCs-derived HSCs were evaluated by detecting the population of CD34+ and CD34+Sca-1+ cells with flow cytometry and the blast colony-forming cells (BL-CFCs), high proliferative potential colony-forming cells (HPP-CFCs) by using semi-solid medium colonial culture. Finally, the homing and hematopoietic reconstruction abilities of HSCs were evaluated using a murine model of HSC transplantation in vivo. RESULTS: AGM and BM-derived stromal cells were morphologically and phenotypically similar, and had the features of stromal cells. When co-cultured with AGM or BM stromal cells, more primitive progenitor cells (HPP-CFCs) could be detected in ESCs derived hematopoietic precursor cells, but BL-CFC's expansion could be detected only when co-cultured with AGM-derived stromal cells. The population of CD34+ hematopoietic stem/progenitor cells were expanded 3 times, but no significant expansion in the population of CD34+Sca-1+ cells was noted when co-cultured with BM stromal cells. While both CD34+ hematopoietic stem/progenitor cells and CD34+Sca-1+ cells were expanded 4 to 5 times respectively when co-cultured with AGM stromal cells. AGM region-derived stromal cells, like BM-derived stromal cells, could promote hematopoietic reconstruction and HSCs' homing to BM in vivo. CONCLUSIONS: AGM-derived stromal cells in comparison with the BM-derived stromal cells could not only support the expansion of HSCs but also maintain the self-renewal and multi-lineage differentiation more effectively. They are promising in HSC transplantation.

[The clinical application of splenectomy in pyrexia of unknown origin with splenomegaly].

OBJECTIVE: To observe the clinical value of splenectomy for pathologic diagnosis in fever of unknown origin with splenomegaly only. METHODS: The pathologic findings of 35 patients with fever of unknown origin and splenomegaly treated by splenectomy, admitted in to the department of hematology in our hospital since 1996 were studied retrospectively. For these patients, there were no other positive signs except splenomegaly and the routine tests could not help us make the etiological diagnoses. RESULTS: In these 35 patients, there were 17 cases of non-Hodgkin's lymphoma (48.6%), 5 cases of Hodgkin's disease (14.2%), 2 cases of malignant histiocytosis (5.7%), 5 cases of connective tissue disease (14.2%), 2 cases of chronic congestive splenomegaly (5.7%), 1 case of hemophagocytic syndrome (2.9%), 1 case of remote spleen infarction (2.9%), 1 case of tuberculosis of spleen (2.9%) and 1 case of spleen angiosarcoma (2.9%). CONCLUSION: When only splenomegaly is found in patients with fever of unknown origin, it is necessary to persuade the patients to accept diagnostic splenectomy for pathological as soon as possible, otherwise, the diagnosis and treatment may be delayed.

Study on the effects of Guiqi Oral Liquid in promoting recovery of hematopoiesis in acute irradiation injured mice.

OBJECTIVE: To explore the effects and possible mechanisms of Guiqi Oral Liquid (GQOL) on the recovery of hematopoiesis in acute irradiation injured mice. METHODS: The acute irradiation injured mice were randomly divided into 2 groups: the treated group and the control group, and also a normal control group was set up with 6 mice in it receiving no treatment. After the mice in the former two groups were irradiated by 6.0 Gy (60)Co gamma-ray, every one of them was given 0.4 ml GQOL or saline in equal volume through a gastric tube twice a day for 14 days. On the 4th, 8th and 14th day after irradiation, the bone marrow mononuclear cells (BMMNC) and megakaryocytes in bone marrow tissues of the mice were counted, the proportion of hematopoietic tissues (by area) was measured, and the expression of adhesion molecules, CD44 and CD54, in bone marrow were estimated by immunochemistry. The colony forming unit of spleen (CFU-S) in the mice were counted on the 8th day after irradiation. RESULTS: On the 4th, 8th, 14th day after irradiation, the count of BMMNC and megakaryocyte, and the proportion of hematopoietic tissues in the treated group were higher than those in the control group (P < 0.01 or P < 0.05). CD44 and CD54 expression in the treated group were higher than those in the control group on the 4th and 8th day (P < 0.01), but near normal on the 14th day (P < 0.01). On the 8th day, CFU-S count in the treated group was higher than that in the control group (P < 0.01). CONCLUSION: GQOL can regulate the expression of adhesion molecules, CD44 and CD54, in the bone marrow of the acute irradiation injured mice, which may be one of the mechanisms of GQOL in accelerating the early phase hematopoiesis recovery of mice.

Predicting the Incidence of Human Cataract through Retinal Imaging Technology.

With the progress of science, technology and medicine, the proportion of elderly people in society has gradually increased over the years. Thus, the medical care and health issues of this population have drawn increasing attention. In particular, among the common medical problems of the elderly, the occurrence of cataracts has been widely observed. In this study, we developed retinal imaging technology by establishing a human eye module with ray tracing. Periodic hole arrays with different degrees were constructed on the anterior surface of the lens to emulate the eyesight decline caused by cataracts. Then, we successfully predicted the incidence of cataracts among people with myopia ranging from -3.0 D to -9.0 D. Results show that periodic hole arrays cause severe eyesight decline when they are centralized in the visual center. However, the wide distribution of these arrays on the anterior surface of the lens would not significantly affect one's eyesight.

[Effect of ligustrazine on expressions of basic fibroblast growth factor and its receptor in bone marrow of mice with acute radiation injury].

OBJECTIVE: To study the expressions of basic fibroblast growth factor (bFGF) and its receptor (bFGFR) in bone marrow of mice with acute radiation injury, and to evaluate the effect of Ligustrazine (Lt) on them. METHODS: Fifty-six Kunming mice of clean grade were randomly divided into 3 groups, the normal group, the control group and the Lt group. Mice in the latter two groups were once homogeneously systemic irradiated with 6.0 Gy of 60Co, with the absorption dose rate of 0.56 Gy/min, then treated with saline (0.2 ml/mice) or Lt (2 mg/mice) respectively, twice a day through gastrogavage for successive 13 days. Mice were sacrificed in batch on the 3rd, 7th and 14th day by cervical dislocation to collect the bilateral femoral bone marrow for preparing bone marrow mono-nuclear cell (BMMNC) suspension. The bFGFR expression on surface of BMMNC was determined by flow cytometry; and the bFGF expression level in one side of femoral bone marrow tissue was detected by immunohistochemistry with SABC-AP assay. RESULTS: The bFGF expression in bone marrow of mice on the 3rd, 7th and 14th day after acute radiation injury all were significantly lower than that of the normal mice (P < 0.05 or P < 0.01). The expressions of bFGF and bFGFR in the Lt group detected were significantly higher than that in the control group detected at the corresponding time points (P < 0.05 or P < 0.01). CONCLUSION: By way of enhancing bFGF expression in bone marrow and bFGFR expression on surface of BMMNC to accelerate the repairing of homopoietic micro-environment in bone marrow might be one of the mechanisms of Lt in promoting hemopoietic function reconstitution after acute radiation injury.

[Effect of ligustrazine on bone marrow hematopoiesis in mice after bone marrow transplantation].

OBJECTIVE: To investigate the effect of ligustrazine (LT) on hematopoiesis in mice after bone marrow isotransplantation (iso-BMT). METHODS: The typical model of iso-BMT was established and the model mice were randomly divided into two groups, the LT group treated with LT injection 0.2 ml and the control group treated with normal saline 0.2 ml, twice a day by gastrogavage. The following parameters were observed in the day 1, 7 and 14: peripheral blood cells, bone marrow mono-nuclear cells (BMMNC), heparin sulfate (HS) expression in bone marrow section by immunohistochemical SABC-AP method, stromal cell derived factor-1 (SDF-1) expression and CXC chemotaxis factor receptor 4 (CXCR4) expression. RESULTS: The levels of peripheral WBC, platelet, BMMNC, CXCR4, HS, SDF-1 at the day 7 and 14 in the LT group were all higher significantly than those in the control group (P < 0.05 or P < 0.01). CONCLUSION: LT could improve the bone marrow hematopoiesis in the early hematopoietic re-establishing stage after BMT.

[Gene mutation and myelodysplastic syndromes with ring sideroblast excess].

Myelodysplastic syndromes (MDS) are heterogeneous clonal hematopoietic stem cell disorders with different mechanisms and diverse prognosis. The excess of ring sideroblasts (RS) is an important presentation MDS, but the mechanisms of RS appearance are obscure and the treatment of MDS-RS is intractable. Splicing factors play a very important role in the maturation process of eucaryon mRNA, recent studies indicate that there is a significant causal relationship between splicing factor 3B subunit 1 (SF3B1) mutation and the presence of ring sideroblasts. Lucubrating the downstream molecular of the mutated SF3B1 can facilitate exploring the mechanisms and new therapeutic strategies of MDS-RS.

[Effect of Gli1 gene silencing on proliferation of K562 cells and its mechanisms].

OBJECTIVE: To investigate the effect of Gli1 gene silencing by RNA interference (RNAi) on proliferation of K562 cells and its mechanisms. METHODS: The small interference RNA (siRNA) was synthesized in vitro. K562 cells were transfected with Gli1 siRNA by the way of lipofection (lipofectamine 2000). Non-specific siRNA transfected cells were used as control. Transfection efficiencies of different siRNA concentrations were detected by flow cytometry and the best siRNA concentration was selected. The silencing effect of siRNA was demonstrated by real time PCR and Westem blot analysis. Cell proliferation was measured by MTT method, cell cycle by PI assay, c-myc and p21 mRNA level was detected by real time PCR analysis. RESULTS: Transfection efficiency of siRNA was increased in a dose-dependent manner when siRNA concentration was below 200 pmol, and the highest transfection efficiency reached (80.11 ± 5.63)%. Both the mRNA and protein level of Gli1 was down-regulated in Gli1 specific siRNA group, the mRNA level was (52.60 ± 3.57)% of that of control group after 24 h (t = 20.33, P < 0.01) and the protein level was (79.31 ± 5.58)% of that of control group after 48 h (t = 6.54, P < 0.01). The cell proliferation rate in Gli1 siRNA group was (94.41 ± 3.58)% (t = 2.40, P = 0.05) and (90.22 ± 3.34)% (t = 4.37, P < 0.01) of that of control group after 24 h and 48 h, respectively. G(2)/M cell cycle arrest was observed, the mRNA level of c-myc was down-regulated while p21 was up-regulated in Gli1 siRNA group after 24 h and 48 h (P < 0.05). CONCLUSIONS: Targeted silencing of Gli1 gene by RNAi inhibits the proliferation of K562 cells, which acts through the down-regulation of c-myc and up-regulation of p21 expression.

[Relation of notch pathway to senescence of murine bone marrow stromal cells].

This study was purposed to investigate the relation of the Notch signaling pathway to senescence of murine bone marrow stromal cells in vitro. Intracellular domain of Notch 1 (ICN) was transfected into cultured murine bone marrow stromal cells by lipofectamine transfection. After transfection for three days the proliferation of transfected cells was measured by MTT, cell cycle distribution was analyzed by flow cytometry. The percentage of senescence associated beta-galactosidase (SA-beta-Gal) positive cells were measured by cytochemical method, and the expression rates of P53 and p21Cip1/Waf1 at gene and protein levels were analyzed by RT-PCR and Western blot respectively. The results showed that after transfection for 3 days the proliferation of murine bone marrow stromal cells was inhibited with induction of G1 arrest, the percentage of SA-beta-gal positive cells increased and the p53 and p21Cip1/Waf1 mRNA and protein expression levels were upregulated. It is concluded that the activated Notch signaling can induce premature senescence of bone marrow stromal cells through the p53-p21Cip1/Waf1 pathway.

[Aberrant methylation at promoter region of HOX A gene cluster in leukemia cells].

OBJECTIVE: To explore the characteristics of CpG islands methylation at promoter region of HOX A gene cluster in leukemia cells before and after all-trans retinoic acid (ATRA) treatment. METHODS: Eleven human leukemia cell lines, bone marrow cells from leukemia patients before and after therapy and white blood cells from normal subjects were collected. HL-60 and K562 cells were treated by 2-deoxy-5-azacytidine (DAC) or ATRA respectively. Bisulfite modified DNA of these cells were amplified with PCR and quantitatively analyzed by pyrosequencing for methylation of CpG islands. RESULTS: In normal cells, CpGs at all loci of HOX A cluster were unmethylated. In HOX A4, A6, A7, A9, A10 and A11, many CpG sites were methylated (>20%) or hypermethylated (>50%) in leukemia cell lines. Percentages of methylated CpGs were higher in T-cell leukemia (71.4%) and B-cell leukemia (85.7%) than in others. For individual CpGs methylations there were HOX A4 in all leukemia cells, HOX A6 and HOX A7 in most of the leukemia samples and HOX A10 and HOX A11 in K562 and HL-60 cells (38%-86%). HOX A9 CpGs showed hypomethylation in most of myeloid leukemia cells, whereas HOX A11 CpGs were hypermethylated in B-cell leukemia (>50%). Methylation levels of HOX A4 and A6 in AML and ALL patients after complete remission were decreased obviously, and so did HOX A6 and A9 in CML patients. Methylation levels of HOX A4, A6 and A10 in HL-60 cells and of HOX A6 in K562 cells were reduced by ATRA treatment. CONCLUSIONS: In all leukemia cell lines, aberrant methylation of CpGs was observed at promoter regions of 6 HOX A cluster genes, and some of these genes showed leukemia-type-specific hypermethylation. CpGs methylation of some HOX A genes in leukemia cell lines, especially in HL-60 cells, were down-regulated by ATRA.

[Study on Wnt and Notch signalling involves in regulation of hematopoietic microenvironment.].

OBJECTIVE: To explore the mechanism of Wnt and Notch pathway involved modulating time and spatial restricted hematopoiesis. METHODS: Murine hematopoietic stem and progenitor cells (HSPCs) were isolated from bone marrow (BM) by using c-kit microbeads. E10.5 aorta-gonad-mesonephros (AGM), E12.5, E14.5, E16.5 fetal liver (FL) and adult BM derived stromal cells (StroCs) were isolated and co-cultured with c-kit(+)HSPCs. The floating cells in co-culture system were sorted and counted by FACS. Gene expressions of Wnt and Notch pathway were detected by quantitative PCR and protein expressions by immunostaining. RESULTS: Co-culturing HSPCs with AGM and FL-derived StroCs resulted in an expansion of c-kit(+)population from 0.4 x 10(5)/well to (19.2 +/- 3.2) x 10(5)/well and (26.8 +/- 5.4) x 10(5)/well, respectively, being greater than that with BM-derived StroCs (P < 0.05). The percentage of c-kit(+)cells detected in AGM- and BM- derived StroCs culture system was (75.2 +/- 7.1)%, (74.1 +/- 6.2)% respectively, being higher than FL- derived StroCs culture system (63.4 +/- 5.3)% (P < 0.05). Wnt and Notch pathway genes expression varied at different phases of hematopoiesis. Wnt was highly expressed in AGM and FL derived StroCs, and, Notch did in AGM and BM derived StroCs. CONCLUSION: Wnt and Notch pathway are important modulators in regulating time and spatial restricted hematopoiesis.

[Establishment of a bone marrow failure mouse model by immune injury].

OBJECTIVE: To establish a mouse model for the study of pathophysiologic mechanism and treatment of bone marrow failure (BMF). METHODS: Balb/c mice (recipient) were irradiated 5.0 Gy by gamma rays of (60)Co, and then infused 5 x 10(6) lymph node (LN) cells from DBA/2 mice (donor) in 4 hours. Pancytopenia was monitored by cell counting, bone marrow damage was assessed by histological staining and mononuclear cell counting. Serum IFN-gamma concentration was measured by ELISA. The proportion of Treg in spleen was detected by flow cytometry. RESULTS: Irradiation and infusion of LN cells led to rapid development of severe pancytopenia and BM hypoplasia, which reached the most severity at d14. The pancytopenia remained at d28 and displayed no signs of recovery. The bone marrow was full of adipose cells with scarcity of hematopoietic cells at d14 and persisted at least for 28 days, being similar to the feature of aplastic anemia. Serum IFN-gamma concentration was 6.3 fold increased \[(170.0 +/- 17.0) vs (27.7 +/- 7.1) pg/ml\] at d6. Tregs were decreased after infusion, and then increased \[(3.38 +/- 0.52)%\] and recovered to normal \[(4.04 +/- 0.44)%\] at d21. The expression level of the specific transcription factor Foxp3 was similar to normal. CONCLUSION: The MHC antigen of Balb/c mice is identical to that of DBA/2 mice, but their minor antigen differs. 5.0 Gy irradiation and then 5 x 10(6) lymphocyte infusion can induce BMF similar to the features of aplastic anemia.

[Diagnostic role of BIOMED-2 multiplex polymerase chain reaction for antigen receptor genes rearrangement in lymphoproliferative disorders].

OBJECTIVE: To establish a sensitive and effective method for detection of immunoglobulin and T-cell receptor (Ig/TCR) gene rearrangement,and to explore its role in diagnosis and differential diagnosis of lymphoproliferative disorders. METHODS: Fifty-eight lymphoid tissue samples from 54 patients with lymphoproliferations were evaluated by the novel BIOMED-2 multiplex polymerase chain reaction (PCR) for antigen receptor genes rearrangement. RESULTS: Multiplex PCR demonstrated monoclonal Ig/TCR gene rearrangements in 22 of 25 (88.0%) B-cell malignancies and 8 of 15 (53.3%) T-cell malignancies. Among 17 benign lymphoproliferations confirmed histopathologically, polyclonal rearrangements were detected in 14 cases (82.4%). In total, the clonality analysis and the final clinico-histopathological diagnosis were concordant in 77.2%. Combination detection of Iglambda and TCR delta gene rearrangements did not increase the detection rate of monoclonal rearrangement of Ig/TCR, but might help to the detection of Iglambda+ or TCR delta+ lymphomas. CONCLUSION: The novel BIOMED-2 multiplex PCR strategy is a rapid, reliable and sensitive approach to detecting clonality in suspected lymphoproliferations, especially in atypical cases.