In-orbit operation of an atomic clock based on laser-cooled Rb atoms.

Atomic clocks based on laser-cooled atoms are widely used as primary frequency standards. Deploying such cold atom clocks (CACs) in space is foreseen to have many applications. Here we present tests of a CAC operating in space.

All-optical frequency stabilization and linewidth reduction of distributed feedback diode lasers by polarization rotated optical feedback.

The frequency of a distributed feedback diode laser (DFB-LD) is stabilized on Cesium ((133)Cs) D(2) saturated absorption lines by the polarization rotated optical feedback method (PROF). Different from the conventional frequency stabilization methods by adjusting the LD pump current, no extra electrical feedback is needed with the PROF. The self-homodyne beat spectra FWHM linewidth of the DFB laser is measured to be 1.

[Construct Mxi1 mutation gene expression vector from leukemia cell line KG1].

Objective: To construct the eukaryotic expression vector for Max interacting protein 1 (Mxi1).

Methods: The full length cDNA of Mxi1 gene obtained from fetal lymphocyte and KG1 cells were inserted into plasmid pDs-red2-N1 respectively to generate pDs-red2-N1/Mri1 (wild/mutation type). Then the recombinant vector was transfected into Cos-7 cells via liposome.

[Preliminary study on the effect of TRAIL on adhesion and apoptosis of multiple myeloma cell line RPMI8226 and its mechanism].

The present study was purposed to investigate the inhibition effect of tumor necrosis factor-related apoptosis inducing ligand (TRAIL) on growth of RPMI8226 cells and adhesion between RPMI8226 cells and bone marrow stroma cells (BMSC), and to explore its mechanism as well. The inhibition effects of TRAIL on cells growth and adhesion were assayed by MTT; cell apoptosis was detected by Annexin V and PI; expression of genes bax, bcl-2, mcl-1, CARP1, CARP2, XIAP and cFLIP were determined by semi-quantitative RT-PCR; apoptosis-related protein expression was detected by Western blot. The results showed that TRAIL inhibited the proliferation of RPMI8226 cells in dose- and time-dependent manners.

[Construction of expression plasmid for fused idiotypic DNA vaccine of B-cell lymphoma].

The idiotypic determinant of surface immunoglobulin of B-cell lymphoma, as a tumor-specific antigen, has proved to be able to induce immune responses. To analyze whether an idiotypic vaccine fused with cytokine can elicit more effectively protective antitumor immunity, an eukaryotic expression plasmid was constructed, which encoded the fusion gene of single-chain variable fragment as a tumor specific antigen against B-cell lymphoma with monocyte chemotactic protein-3 (MCP3) as immunogen to elicit T-cell-dependent protective antitumor immunity, and EGFP (Enhanced Green Fluorescent Protein) gene as a marker to trace the survival, growth, differentiation and expression of the former exogenetic genes. The cDNAs for immunoglobulin (Ig) VH and IgVL were amplified by RT-PCR and assembled into the single-chain variable fragment (scFv) connected with a (Gly(4)Ser)(3) linker by recombinant PCR method.

[As2O3 induces demethylation and up-regulates transcription of SHP-1 gene in human lymphoma cell line T2 cells].

Objective: To investigate the methylation of CpG island in the SHP-1 gene promoter and its significance in lymphoma. To evaluate the effects of As2O3 on demethylation of SHP-1 in human lymphoma cell line T2 and on proliferation of T2 cells.

Methods: T2 cells were treated with AsO3.

[Effect of a methylation inhibitor 5-aza-2'-deoxycytidine on SHP-1 gene expression, proliferation and apoptosis in K562 cells].

The aim of this study was to investigate the regulation of 5-aza-CdR on transcription of SHP-1 gene and effects on the proliferation and apoptosis of K562 cells. Methylation-specific PCR (MSP) was used to detect CpG island methylation in SHP-1 promoter. MTT and flow cytometry were used to detect the growth and apoptosis of K562 cells after treatment with different concentration of 5-aza-CdR.

[Expression and mutation of myc antagonist genes Mad1, Mxi1 and Rox in leukemia cells].

Objective: To investigate the expression and mutation of Mad1, Mxi1 and Rox genes in leukemia cells.

Methods: Expression and mutation of Mad1, Mxi1 and Rox genes in bone marrow mononuclear cells (BMMNC) from 26 de novo acute leukemia (AL) patients, and in peripheral blood mononuclear cells (PBMNC) from 30 healthy volunteers, as well as in 7 human leukemic cell lines were analyzed by reverse transcription-polymerase chain reaction (RT-PCR), single strand conformational polymorphism (SSCP) and DNA sequencing.

Results: RT-PCR showed that all the above cells expressed Mad1, Mxi1 and Rox mRNA.

Experimental investigation of optical beam deflection based on PLZT electro-optic ceramic.

Based on the optical characteristics of PLZT (Lead Lanthanum Zirconate Titanate) electro-optic ceramic, two kinds of electro-optical deflectors, triangular electrode structure and optical phased array technology, are studied in detail by using transverse electro-optic effect. Theoretically, the electro-optic deflection characteristics and mechanisms of the deflectors are analyzed; experimentally, the optical characteristics of ceramic wafer, such as the phase modulation, the hysteresis and the electro-induced loss characteristics, are measured; a systematic experiment is designed to verify the theoretical results. The effect of temperature on the performance of deflector is also investigated.

[Angioimmunoblastic T-cell lymphoma with autoimmune hemolytic anemia and pure red cell aplasia].

Angioimmunoblastic T-cell lymphoma (AILT) is a peripheral T-cell lymphoma often complicated autoimmune phenomena such as autoimmune cytopenia, and is a truly rare type of NHL. In order to investigate the clinical features, pathological manifestation of this lymphoma, and to explore its therapy protocol, a 37-years old patient with AILT was investigated. The routine blood examination, bone marrow smear, lymphonodus biopsy, Coombs test, flow cytometry for bone marrow mononuclear cells, serological test, immunochemistry method etc were performed for this patient.

[Immunoglobulin D lambda multiple myeloma: a case report].

To improve the recognition of immunoglobulin D multiple myeloma and explore its clinical feature and laboratory examination characteristics, so as to reduce the the missed diagnosis and misdiagnosis, a case of IgD multiple myeloma (MM) with myelofibrosis and bone marrow necrosis is reported. The clinical feature, treatment and prognosis of IgDlambda MM were discussed. Immunoglobulin D multiple myeloma is a rare disease and predominantly occurs in young male patients, which shows an aggressive clinical course with poor response to conventional treatment and unfavorable prognosis.

Expression and mutation analysis of genes that encode the Myc antagonists Mad1, Mxi1 and Rox in acute leukaemia.

The Myc antagonists Mad1, Mxi1 and Rox proteins share two highly conserved domains, Sin3-interacting domain (SID) and basic helix-loop-helix leucine zipper domain (bHLHzip), which are essential for these proteins to function during molecular switching from proliferation to differentiation. In an attempt to identify mutations in Mad1, Mxi1 and Rox genes in human haematological malignancies, we screened 10 haematopoietic cell lines, bone marrow mononuclear cells (BMMNC) from 26 patients with haematological malignancies and peripheral blood mononuclear cells (PBMNC) from 30 healthy volunteers, using reverse transcription-polymerase chain reaction, single strand conformation polymorphism analysis and sequencing. Mad1, Mxi1 and Rox genes were expressed in all samples.

Calibration method for a photoelastic modulator with a peak retardation of less than a half-wavelength.

A new calibration method for a photoelastic modulator is proposed. The calibration includes a coarse calibration and a fine calibration. In the coarse calibration, the peak retardation of the photoelastic modulator is set near 1.

[Construction and expression of a prokaryotic expression plasmid of idiotypic vaccine against B cell lymphoma: encoding the fusion genes of single-chain variable fragment and MCP-3].

The aim was to construct a prokaryotic expression plasmid encoding the fusion gene of single-chain variable fragment and monocyte chemotactic protein-3 (MCP-3). The cDNAs of immunoglobulin (Ig) VH and Ig VL were amplified by RT-PCR and assembled into the single-chain variable fragment (scFv) by recombinant PCR method. The cDNAs of Ig VH and Ig VL were connected by a (Gly4Ser)3 linker.

[Combined effect of recombinant mutant human TRAIL and daunorubicin in inducing apoptosis of leukemia cell and its mechanism].

The aim of study was to investigate the combined effect of recombinant mutant human TRAIL (rmhTRAIL) with daunorubicin (DNR) or alone on K562 and U937 leukemia cell lines and its mechanism. The fibroblasts (MRC-5) of normal-human embryonic lung were used as control cells. After being treated with rmhTRAIL and DNR or only with rmTRAIL, the cytotoxic effect and the apoptosis rate in K562, U937 cells were measured by MTT assay.

WT1 gene expression lowered by IL-12 In vitro in peripheral blood mononuclear cells from patients with leukemia or myelodysplastic syndromes.

Previous studies demonstrated that interleukin-12 (IL-12) enhances the non-MHC-restricted cytotoxic activity of NK cells and facilitate specific allogeneic human cytotoxic T lymphocyte responses against fresh leukemia cells and cell lines. The Wilms' tumor gene, WT1 mRNA, has been used as a marker of minimal residual disease (MRD) for evaluating therapeutic efficacy of patients with leukemia or myelodysplastic syndrome (MDS). This study was aimed to investigate whether in vitro IL-12 can lower WT1 gene expression in peripheral blood monuclear cells (PBMNC) from patients with leukemia or MDS.

[Expression of midkine in patients with acute myeloid leukemia and its significance].

The study was aimed to investigate the expression of midkine (MK) in bone marrow mononuclear cells (BM MNC) from 65 acute myeloid leukemia patients and 15 normal controls. The method of RT-PCR was used to examine the expression of MK mRNA in BM MNC. Parts of samples were incubated for 24 hours and the gene expression of MK in the BM MNC was detected by means of Western blot.

[Relationship between VEGF and MMP-2, MMP-9 in 82 patients with acute myeloid leukemia].

In order to investigate the relationship between VEGF and matrix metalloproteinase (MMP)-2, -9 in acute myeloid leukemia patients, and evaluate the significance of them in extramedullary leukemic invasion, the expressions of MMP-2 mRNA, MMP-9 mRNA, VEGF mRNA in bone marrow from 86 patients with acute myeloid leukemia (AML), as well as human hematopoietic cell lines were analyzed by reverse transcription-polymerase chain reaction (RT-PCR). The proteolytic activities of MMP-2 and MMP-9 in the supernatants were measured by zymography. The VEGF protein in serum of all samples was detected by ELISA.

Comparative study of expressions of cytoplasmic CD79a and other B-lymphoid immunomarkers in acute leukemic cells.

To evaluate the expression of cytoplasmic CD79a (CyCD79a) and other commonly used B-lymphoid immunomarkers including cytoplasmic CD22 (CyCD22), CD19, CD20 and CD10 in various acute leukemia cells and to define the most sensitive and specific markers in the diagnosis of precursor B-cell acute lymphoblastic leukemia (pB-ALL), the immunophenotypic data from 221 de novo adult and pediatric acute leukemia patients as studied using multi-parameter flow cytometry in addition to routine morphologic and enzyme cytochemical assay, were retrospectively analyzed. Cytogenetic and/or molecular biological data in all 45 cases of acute promyelocytic leukemia (APL) and 13 cases of acute leukemia suspected as AML with the fusion genes such as AML1/ETO and CBFbeta/MYH11 were investigated. The results showed that CyCD79a and CyCD22 were the most sensitive and specific markers respectively for pB-ALL.

[Comparison of therapeutic effects of low-dose versus high-dose interferon alpha-2b treatment on chronic myelocytic leukemia: a prospective randomized study].

Objective: To compare the therapeutic effects of low-dose and high-dose interferon alpha-2b (IFN) treatment on chronic myelocytic leukemia (CML).

Methods: A real-time quantitative reverse transcriptase PCR (RQ-PCR) method was established to detect the fusion gene bcr-abl expression, thereby studying the reduction of leukemic cells. Thirty newly diagnosed CML patients, 21 males and 9 females, aged 14 - 69, were treated with hydroxyurea to keep the white blood cell count less than 20 x 10(9)/L, and then randomized into 2 groups: high-dose IFN group receiving IFN alpha-2b 5MIU 6 times per week for 3 - 6 months and low-dose IFN group receiving IFN alpha-2b 3MIU every other day for 3 - 6 months.

[A case of hepatosplenic gammadelta T cell lymphoma].

Hepatosplenic gammadelta T cell lymphoma represents rare, often aggressive type of malignant peripheral T-cell lymphoma, which is characterized by expressing T-cell-associated markers CD2, CD3 and gammadelta T-cell receptor, and nonactivated cytotoxic cell phenotype (TIA-1+, granzyme B-). The pathological findings of a liver biopsy specimen revealed the diffuse infiltration of lymphocytes in the sinusoids and the aspiration biopsy from spleen revealed the diffuse infiltration of lymphocytes in the red pulp, not shaped to the nodes, often resulted in the misdiagnosis. Recently, by analyzing the immunophenotype and TCR rearrangement from liver, spleen and bone marrow, a case of adult hepatosplenic gammadelta T cell lymphoma was diagnosed.

mitochondrial ceramidase overexpression up-regulates Bcl-2 protein level in K562 cells, probably through its metabolite sphingosine-1-phosphate.

Recently, a mitochondrial ceramidase has been identified and cloned, whose mitochondrial localization strongly suggests the existence of an unexpected mitochondrial pathway of ceramide metabolism that may play a key role in mitochondrial functions, especially in the regulation of apoptosis. To explore the biological effect of mitochondrial ceramidase on cells, pcDNA 3.1/His-CDase plasmid, containing mitochondrial ceramidase cDNA sequence, was transducted into K562 cells mediated by liposome, and G418 was used to screen for positive colonies.

Mutation analysis of SHIP gene in acute leukemia.

The SH2 domain containing inositol 5'-phosphatase (SHIP) was initially described as a 145 kD protein phosphorylated on tyrosines upon growth factor and cytokine stimulation. SHIP is predominately expressed in hematopoietic cells, and is a crucial negative regulator in the development of hematopoietic cells. To evaluate the role of the SHIP gene in human leukemogenesis, expression and mutation of SHIP gene in bone marrow and/or peripheral blood from 32 patients with acute myeloid leukemia (AML), 9 patients with acute lymphoblastic leukemia (ALL), as well as human hematopoietic cell lines were analyzed by reverse transcription-polymerase chain reaction (RT-PCR), single strand conformational polymorphism (SSCP) and sequencing.

[Mutation analysis of SHIP gene in acute leukemia].

Objective: The SH2 domain containing inositol 5'-phosphatase (SHIP) is predominately expressed in hematopoietic cells, and is a crucial negative regulator in the development of hematopoietic cells. This paper is to evaluate the role of the SHIP gene in human leukemogenesis.

Methods: Expression of SHIP gene in bone marrow and/or peripheral blood from 32 patients with acute myeloid leukemia (AML), 9 with acute lymphoblastic leukemia (ALL), as well as human hematopoietic cell lines was analyzed by reverse transcription-polymerase chain reaction (RT-PCR), single strand conformational polymorphism (SSCP) and DNA sequencing.