Ejecta from the DART-produced active asteroid Dimorphos.

Some active asteroids have been proposed to be formed as a result of impact events1. Because active asteroids are generally discovered by chance only after their tails have fully formed, the process of how impact ejecta evolve into a tail has, to our knowledge, not been directly observed. The Double Asteroid Redirection Test (DART) mission of NASA2, in addition to having successfully changed the orbital period of Dimorphos3, demonstrated the activation process of an asteroid resulting from an impact under precisely known conditions. Here we report the observations of the DART impact ejecta with the Hubble Space Telescope from impact time T + 15 min to T + 18.5 days at spatial resolutions of around 2.1 km per pixel. Our observations reveal the complex evolution of the ejecta, which are first dominated by the gravitational interaction between the Didymos binary system and the ejected dust and subsequently by solar radiation pressure. The lowest-speed ejecta dispersed through a sustained tail that had a consistent morphology with previously observed asteroid tails thought to be produced by an impact4,5. The evolution of the ejecta after the controlled impact experiment of DART thus provides a framework for understanding the fundamental mechanisms that act on asteroids disrupted by a natural impact1,6.

Momentum transfer from the DART mission kinetic impact on asteroid Dimorphos.

The NASA Double Asteroid Redirection Test (DART) mission performed a kinetic impact on asteroid Dimorphos, the satellite of the binary asteroid (65803) Didymos, at 23:14 UTC on 26 September 2022 as a planetary defence test1. DART was the first hypervelocity impact experiment on an asteroid at size and velocity scales relevant to planetary defence, intended to validate kinetic impact as a means of asteroid deflection. Here we report a determination of the momentum transferred to an asteroid by kinetic impact. On the basis of the change in the binary orbit period2, we find an instantaneous reduction in Dimorphos's along-track orbital velocity component of 2.70 ± 0.10 mm s-1, indicating enhanced momentum transfer due to recoil from ejecta streams produced by the impact3,4. For a Dimorphos bulk density range of 1,500 to 3,300 kg m-3, we find that the expected value of the momentum enhancement factor, ß, ranges between 2.2 and 4.9, depending on the mass of Dimorphos. If Dimorphos and Didymos are assumed to have equal densities of 2,400 kg m-3, [Formula: see text]. These ß values indicate that substantially more momentum was transferred to Dimorphos from the escaping impact ejecta than was incident with DART. Therefore, the DART kinetic impact was highly effective in deflecting the asteroid Dimorphos.

GAUSS - genesis of asteroids and evolution of the solar system: A sample return mission to Ceres.

The goal of Project GAUSS (Genesis of Asteroids and evolUtion of the Solar System) is to return samples from the dwarf planet Ceres. Ceres is the most accessible candidate of ocean worlds and the largest reservoir of water in the inner Solar System. It shows active volcanism and hydrothermal activities in recent history. Recent evidence for the existence of a subsurface ocean on Ceres and the complex geochemistry suggest past habitability and even the potential for ongoing habitability. GAUSS will return samples from Ceres with the aim of answering the following top-level scientific questions: What is the origin of Ceres and what does this imply for the origin of water and other volatiles in the inner Solar System?What are the physical properties and internal structure of Ceres? What do they tell us about the evolutionary and aqueous alteration history of dwarf planets?What are the astrobiological implications of Ceres? Is it still habitable today?What are the mineralogical connections between Ceres and our current collections of carbonaceous meteorites?

Association of bone mineral density with peripheral blood cell counts and hemoglobin in Chinese postmenopausal women: A retrospective study.

Osteoporosis (OP) is a metabolic bone disease that can cause structural changes in bone marrow cavity. Bone marrow is the hematopoietic organ of adults. Accumulating evidence has shown a close connection between bone marrow hematopoietic function and bone formation. Some studies have revealed that OP is associated with hematopoiesis. However, the relationship is not definite.This study aimed to evaluate the association between peripheral blood cell counts (white blood cells [WBC], red blood cells [RBC], platelets [PLT]), hemoglobin [HGB], and bone mineral density [BMD]) in a sample of Chinese postmenopausal women. This is a retrospective study involving 673 postmenopausal women cases. The BMD of lumbar spine and left hip joint were measured by dual-energy X-ray absorptiometry. The levels of blood cell counts and HGB were measured and analyzed.The study results showed the WBC, RBC, PLT, and HGB levels of postmenopausal women in the OP group were all higher than those in the non-osteoporosis group. Spearman linear trend analysis and partial correlation analysis demonstrated that BMD was negatively correlated with WBC, RBC, PLT, and HGB in postmenopausal women.Due to the differences between different countries and races, and there are few studies on the association of BMD with peripheral blood cell counts and HGB in Chinese Postmenopausal Women. Therefore, more large sample studies are needed.

Screening and evaluation of Smo-siRNA targeted to inhibition of Molt-4 cell proliferation / 中国组织工程研究

BACKGROUND: Studies have shown that the occurrence and development of T lymphocytic leukemia is related to the abnormality of Hedgehog pathway. The Smo gene is a key gene in this signaling pathway and controls the transmission of Hedgehog signaling into the cell membrane. OBJECTIVE: To design and screen a highly efficient and specific Smo-siRNA which is able to downregulate the Smo gene expression in Molt-4 cells, thereby inhibiting the Molt-4 cells proliferation and inducing apoptosis. METHODS: (1) Smo-siRNAs numbered 1, 2 or 3, and the scrambled non-siRNA control (SC) were obtained by chemosynthesis. Untreated and sc-treated cells were used as controls. (2) Smo expression levels in Molt-4 cells were analyzed using qRT-PCR at 24, 48, 72 hours after siRNAs delivered by NuclefectorTM.Cell proliferation in vitro was assayed by the cell counting kit-8.The morphology and percentage of apoptotic cells were revealed by Hoechst33258 staining and flow cytometry, respectively. RESULTS AND CONCLUSION: (1) Smo-siRNAs were successfully transferred into Molt-4 cells, and exhibited best silencing results. After transfection with Smo-siRNA1, the mRNA level of Smo was significantly reduced (P < 0.05), and the lowest level was at 48 hours after transfection. (2) Cell proliferation of Molt-4 cells was significantly inhibited by Smo-siRNA at 24 hours after transfection. (3) Hoechst staining results showed morphological changes of Molt-4 were in accordance with those of apoptotic cells. (4) The apoptotic rate was significantly increased in the Smo-siRNA group compared with the control group (P < 0.05). Findings from this study showed that suppression of Smo by RNA interference could effectively inhibit proliferation and induce apoptosis in Molt-4 cells, indicating that Smo-siRNA as gene targeted therapy or synergistic treatment has therapeutic potential in T-cell malignancies.

Effects of Down-regulating PPP2R5C Expression on Expression Profile of TAL1-related Regulating Genes in Jurkat Cells / 中国实验血液学杂志

<p><b>OBJECTIVE</b>Based on our previous study showing the inhibition of lenkemia T cell proliferation by down-regulating PPP2R5C expression, this study was aimed to analyze the influence of down-regulating PPP2R5 expression via RNA interference on genes relatied with TAL1 signaling pathway by using gene chip technique.</p><p><b>METHODS</b>The PPP2R5C-siRNA799 was transduced into Jurkat cells by nucleofection, the total RNA was isolated from treated Jurkat cells after culture for 48 hours; the target sequences were prepared by revevse transcription after mRNA purification, and were hybridized with affymetrix gene expression profile chip 3' IVT. The original image data were collected using affymetrix gene chip scanner 3 000, and the gene expression profile was analyzed using gene spring GX 11.0 soflware.</p><p><b>RESULTS</b>The expression of all 26 genes related with TAL1 signaling pathway was changed, out of which the expression of 15 genes were up-regulated and the expression of 11 genes was down-regulated in PPP2R5C-siRNA 799-transfected Jurkat cells. The genes with significantly up-regulated expression were GATA1, TCF4, XRCC6 and TCF3, while the genes with significantly down-regulated expression were SIN3A and RUNX1.</p><p><b>CONCLUSION</b>The down-regulation of PPP2R5C gene expression in Jurkat cells via RNA interference to a certain degree can inhibit TAL1 signaling pathway genes, thereby suppresses the proliferation of Jurkat cells.</p>

Elemental mapping by Dawn reveals exogenic H in Vesta's regolith.

Using Dawn's Gamma Ray and Neutron Detector, we tested models of Vesta's evolution based on studies of howardite, eucrite, and diogenite (HED) meteorites. Global Fe/O and Fe/Si ratios are consistent with HED compositions. Neutron measurements confirm that a thick, diogenitic lower crust is exposed in the Rheasilvia basin, which is consistent with global magmatic differentiation. Vesta's regolith contains substantial amounts of hydrogen. The highest hydrogen concentrations coincide with older, low-albedo regions near the equator, where water ice is unstable. The young, Rheasilvia basin contains the lowest concentrations. These observations are consistent with gradual accumulation of hydrogen by infall of carbonaceous chondrites--observed as clasts in some howardites--and subsequent removal or burial of this material by large impacts.

Color and albedo heterogeneity of Vesta from Dawn.

Multispectral images (0.44 to 0.98 µm) of asteroid (4) Vesta obtained by the Dawn Framing Cameras reveal global color variations that uncover and help understand the north-south hemispherical dichotomy. The signature of deep lithologies excavated during the formation of the Rheasilvia basin on the south pole has been preserved on the surface. Color variations (band depth, spectral slope, and eucrite-diogenite abundance) clearly correlate with distinct compositional units. Vesta displays the greatest variation of geometric albedo (0.10 to 0.67) of any asteroid yet observed. Four distinct color units are recognized that chronicle processes--including impact excavation, mass wasting, and space weathering--that shaped the asteroid's surface. Vesta's color and photometric diversity are indicative of its status as a preserved, differentiated protoplanet.

One-year continuous observation of change in peripheral T cell subsets in workers exposed to low levels of benzene / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the T cell subsets and blood cells in the peripheral blood of workers exposed to low levels of benzene for one year, and to investigate the relationship between T cell function impairment and benzene-induced hematopoietic injury after benzene exposure.</p><p><b>METHODS</b>Eighty-eight workers (58 males and 30 females, aged 18 ∼ 22 years) who just began to work in the workshop of a paint factory with exposure to benzene in Guangzhou, China were assigned to experimental group, and 88 workers (58 males and 30 females, aged 18 ∼ 25 years) who worked in the workshop without exposure to benzene were selected as controls. The blood samples of the workers were examined once every 4 months to measure the percentages of peripheral T cell subsets and peripheral blood cell counts in the one-year study. The benzene concentrations at operation points were also measured.</p><p><b>RESULTS</b>The peripheral blood cell counts in the benzene-exposed workers had no significant changes in the first and second examinations; the white blood cell (WBC) counts in the experimental group in the third and fourth examinations were significantly lower than that in the control group [(6.4 ± 3.0)×10(9)/L and (6.3 ± 2.7)×10(9)/L vs (7.3 ± 3.0)×10(9)/L, P < 0.05], and the platelet (PLT) count in the experimental group in the fourth examination was also significantly lower than that in the control group[(179 ± 74)×10(9)/L vs (189 ± 70)×10(9)/L, P < 0.05]. Compared with those in the control group (CD4+: 54.29 ± 12.78%, CD8+: 37.25 ± 12.30%), the percentage of CD3+ T cells in the experimental group increased in the third examination; the percentage of CD4+ T cells in the experimental group decreased continuously in the second, third, and fourth examinations (50.77 ± 11.05%, 45.40 ± 9.41%, and 41.27 ± 10.62%), while the percentage of CD8+ T cells in the experimental group kept increasing (46.07 ± 10.18%, 50.36 ± 10.62%, and 56.40 ± 9.41%) (P < 0.05).</p><p><b>CONCLUSION</b>The change in T cell subsets precedes that in the blood system in the workers exposed to low levels of benzene.</p>

EPOXI at comet Hartley 2.

Understanding how comets work--what drives their activity--is crucial to the use of comets in studying the early solar system. EPOXI (Extrasolar Planet Observation and Deep Impact Extended Investigation) flew past comet 103P/Hartley 2, one with an unusually small but very active nucleus, taking both images and spectra. Unlike large, relatively inactive nuclei, this nucleus is outgassing primarily because of CO(2), which drags chunks of ice out of the nucleus. It also shows substantial differences in the relative abundance of volatiles from various parts of the nucleus.

Establishment of stable subline of K562 cells expressing human leucocyte antigen a1101 / 中国实验血液学杂志

The aim of this study was to establish a stable subline of K562 cells expressing the HLA-A(*)1101 protein, which was expected to provide target cells for characterizing the HLA-I restrictive antigen specific cytotoxic T lymphocyte (CTL) effects against chronic myeloid leukemia (CML). The HLA-A(*)1101 protein encoding gene was amplified from peripheral blood mononuclear cell (PBMNC) of CML patient by RT-PCR; the 2A peptide linker (D-V-E-X-N-P-G-P) gene was linked to the 3'terminal of the HLA-A(*)1101 gene by recombinant PCR, then the recombinant was cloned into the pEGFP-N3 plasmid which contains an enhanced green fluorescent protein gene, and the eukaryotic recombinant expression vector containing HLA-A(*)1101-T2A-EGFP transcription box was constructed; the pEGFP-N3 vector and recombinant vector was separately electroporated into K562 cells. The expression of GFP was monitored by fluorescence microscopy, finally stably transfected sublines of K562 cells containing HLA-A(*)1101 gene, and of K562 containing pEGFP-N3 vector were obtained by G418 selection; the transcriptional or translational expression of HLA-A(*)1101 gene was detected with RT-PCR and flow cytometry respectively. The results indicated that the eukaryotic expression vector HLA-A(*)1101-T2A-EGFP plasmid was successfully constructed; after G418 selection for 2 months, two sublines of K562 cells (HLA-A(*)1101(+)K562, pEGFP-N3(+)K562) expressing GFP were constructed. The expression of HLA-A*A1101 gene could be determined in HLA-A(*)1101(+)K562 cell line by RT-PCR, while the pEGFP-N3(+)K562 cells could not express HLA-A*A1101 gene. HLA-A(*)1101 protein and GFP double positive HLA-A(*)1101(+)K562 cells were up to 88.5%, which was obviously higher than pEGFP-N3(+)K562 cells (0.698%) by flow cytometric analysis. It is concluded that a simple and effective method to select HLA-A(*)1101(+)K562 cells has been established and a subline of K562 cell expressing HLA-A(*)1101 protein on its cell membrane was successfully constructed, which provides the tool cells for further studying the specific cellular immunity against-CML.

Change of expression pattern of CD3 genes in peripheral blood T-cells from CML patients / 中国实验血液学杂志

Our previous finding showed that down-regulation of CD3ζ gene was detected in patients with chronic myeloid leukemia (CML). In order to further elucidate the feature of T cell immune status in the signal transduction in CML patients, the expression patterns of all 4 CD3 genes were characterized in peripheral blood of patients, the expression levels of CD3γ, δ, ε and ζ chain genes were detected by real time qPCR with SYBR Green I staining in peripheral blood mononuclear cells (PBMNCs) from 17 cases of de novo CML patients in chronic phase and 17 cases of healthy individuals, the ß₂-microglobulin gene was used as an internal reference, and the mRNA expression level of each CD3 gene was evaluated by the 2(-ΔCt) x 100% method. The results showed that the median expression levels of CD3γ, δ and ε genes (2.344%, 0.515% and 3.516%) in CML patients were not significantly different from healthy individuals (p = 0.072, p = 0.190, p = 0.615, respectively), while the expression level of CD3ζ gene in PBMNCs from CML patients (0.395%) was lower than that from healthy individuals (1.538%) (p < 0.001). The expression patterns of 4 CD3 genes in proper order were CD3ε > CD3γ > CD3δ > CD3ζ in CML group, in contrast, the expression patterns were presented as CD3γ > CD3ε > CD3ζ > CD3δ in healthy group. It is concluded that the present study characterized the expression pattern of CD3γ, δ, ε and ζ chain genes in CML patients, lower expression of CD3ζ is the feature of TCR signal transduction immunodeficiency and the expression patterns of 4 CD3 genes are changed in CML patients.

Structural feature and biological function of PPP2R5C gene / 中国实验血液学杂志

PPP2R5C is one of the members of regulatory subunits of protein phosphatase 2A (PP2A), which plays a critical role in cell proliferation, differentiation and transformation, based on its induction of dephosphorylation of P53 at various residues. Recently, it was characterized that the alteration of expression pattern of PPP2R5C is associated with cell malignant transformation, thus PPP2R5C was thought as a marker for progressive disease in B-CLL. In this article the gene structure and biological function of PPP2R5C as well as relation of PPP2R5C with genesis and development of cancer were discussed.

T-cell receptor V alpha gene repertoire and clonal expansion in benzene-exposed workers / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the distribution of TCR V alpha gene repertoire and clonal expansion in peripheral blood mononuclear cells from 9 donors and 16 workers exposed to benzene.</p><p><b>METHODS</b>Complementarity determining region 3 (CDR3) of TCR V alpha subfamily genes were amplified using RT-PCR. The PCR products were further analyzed by genescan to evaluate clonality of T cells.</p><p><b>RESULTS</b>Almost all of 29 V alpha subfamily could be detected in 9 donors. 1 approximately 11 V alpha subfamilies were identified in all but one of the workers studied. The most frequently expressed V alpha subfamily were V alpha 3, V alpha 12 and V alpha 19 (68.8%), V alpha 14 (56.3%), with a lower expression rate found in V alpha 5, V alpha 15, V alpha 16, V alpha 22, V alpha 23 and V alpha 24 (6.3%). Clonal expansion T cells in one or more V alpha subfamily were found in 12 out of all workers studied, including oligoclonal, oligoclonal trend and biclonal patterns. The frequency of clonal expansion T cells in V alpha 12, V alpha 14 and V alpha 19 subfamilies were higher than others.</p><p><b>CONCLUSION</b>Skewed distribution and clonal expansion of TCR V alpha subfamily T cells could be found in workers exposed to benzene. V alpha 12, V alpha 14 and V alpha 19 subfamilies may be highly sensitive to benzene exposed. This is the first report of clonal expansion TCR V alpha T cells in the benzene-exposed group. The bias pattern of TCR V alpha T cells may be due to the immune cytotoxicity from benzene. However, whether the oligoclonality in some V alpha subfamilies reflect the phenomenon of clone absence or may be a response clone to benzene-related impairment during exposed to benzene, remains an open question.</p>

Thymic recent output function in patients with B-cell lymphocytic malignancies / 中国实验血液学杂志

The aim of the study was to analyze the naive T cell level of thymic recent output in patients with B-cell malignancies, thereby to evaluate the potential T-cell function. Quantitative analysis of T-cell receptor rearrangement excision circles (TRECs) in DNA of peripheral blood mononuclear cells from 61 cases of B-cell lymphocytic malignancy (including 20 cases of adult B-ALL, 6 case of childhood B-ALL, 4 cases of B-CLL, 17 cases of B-NHL and 14 cases of MM) were preformed by real-time PCR (TaqMan), and TREC-level was detected according to the number of CD3-positive cells. 5 case of ALL-CR and 17 normal individuals were served as controls. The results showed a dramatic reduction of TREC values in all groups of patients. The mean value of TRECs was 0.53 +/- 1.52 copies/1000 PBMNC and 2.01 +/- 3.93 copies/1000 CD3+ cells in adult B-ALL (p = 0.0005, p = 0.0123), 0.11 +/- 0.15 copies/1000 PBMNC and 0.23 +/- 0.27 copies/1000 CD3+ cells in B-CLL (p = 0.0015, p = 0.0381), 0.71 +/- 1.34 copies/1000 PBMNC in B-NHL (p = 0.0017), 0.53 +/- 0.90 copies/1000 PBMNC in MM patients (p = 0.0018), as compared with 3.76 +/- 3.42 copies/1000 PBMNC and 5.87 +/- 4.96 copies/1000 CD3+ cells in normal individuals, the TREC level was significantly decreased in all groups of B-cell lymphocytic malignancy, as well as in ALL-CR group. However, the TREC level in childhood B-ALL was significant higher than those in adult B-ALL group. It is concluded that the function of thymic recent outputting naive T cells in B-cell malignancies significantly decreases, however, the individual difference of thymic output function is obvious. The thymic recent output function can not be recovered during CR phase in patients with B-cell malignancies, so that dynamic analysis of TREC level is necessary.

Relationship between thymus output function in CML patients and their bcr-abl mRNA levels / 中国实验血液学杂志

The study was purposed to analyze the relationship between the content of T-cell receptor excision DNA circles (TREC) and bcr-abl mRNA levels in CML patients and to evaluate the prognostic significance of recent thymic output function detection in patients with chronic myelogenous leukemia (CML). Quantitative detection of TREC and bcr-abl fusion gene transcripts in peripheral blood from 15 CML patients were preformed by real-time PCR. The change of bcr-abl levels in 6 patients was followed-up for two years. The results showed that there was no significant correlation between TREC and bcr-abl mRNA levels in peripheral blood from CML patients for the first attack. Patients who had higher TREC at diagnosis had a larger reduction of bcr-abl after 2 years of follow-up. While out of 2 patients who underwent haemopoietic stem cell transplantation (HSCT), one patient with higher level of TREC before transplantation was confirmed to express undetectable level of TREC by three consecutive detections after transplantation, other one patient was identified to express low level of bcr-abl. It is concluded that high thymic output function in CML patients can be beneficial for killing the residual CML cells.

Effects of lead exposure on thymic output naive T cells function / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the levels of T cell receptor rearrangement excision DNA circles (TRECs) within peripheral blood from workers exposed to lead, and thereby to evaluate the number of naive T cells and recent thymic output function.</p><p><b>METHODS</b>Quantitative detection of TRECs in peripheral blood mononuclear cells (PBMNC) from 10 cases of workers exposed to lead was performed by real time PCR analysis. 11 workers without exposure to lead served as unexposed controls. In addition, the relationship between TRECs, age, length of service, blood lead, urea lead, blood ZPP and urea delta-ALA was investigated.</p><p><b>RESULTS</b>The mean value of TRECs in workers exposed to lead was (2.44 +/- 1.87)/1000 PBMC, significantly under (5.60 +/- 3.96)/1000 PBMC in unexposed controls. A significant negative correlation was found between the TRECs and urea-ALA. But there was no significant correlation between them after controlling for blood lead, urea lead.</p><p><b>CONCLUSION</b>Lead exposure may damage thymic output naive T cells function. Furthermore, low-level exposure to lead may damage immune system and earlier than expected.</p>

Changes of T lymphocyte subsets in workers with long-term benzene exposure / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the changes of T-lymphocyte subsets in workers with long-term benzene exposure, and further understand the benzene's lymphotoxicity.</p><p><b>METHODS</b>Blood was sampled from 44 patients with chronic benzene poisoning of different degrees, (mild 22 patients, moderate 14, severe 8) respectively. Twenty-two health benzene exposed workers, and 94 health unexposed workers served as normal control. A total of the phenotype (CD4, CD8) of T lymphocyte in peripheral blood was analyzed by indirect immunofluorescence assay.</p><p><b>RESULTS</b>Lymphocyte subset analysis showed significantly decreased CD4(+) T lymphocytes, CD4(+)/CD8(+) ratio, except CD8(+) T lymphocytes in benzene exposed groups (P<0.05). Among the four benzene-exposed groups, CD4(+) T lymphocytes and CD4(+)/CD8(+) ratio showed no difference (P>0.05).</p><p><b>CONCLUSION</b>The primary changes of T-lymphocyte subsets in workers following benzene long-term exposure are the decrease of CD4(+)%, but the changes are not correlated with haematopoietic injury.</p>

Expressions of transcription factor GATA-1 and GATA-2 genes in bone marrow stromal cells from patients with leukemia / 中国实验血液学杂志

In order to investigate expressions of transcription factor GATA-1 and GATA-2 genes in the bone marrow stromal cells (BMSCs) from patients with leukemia or normal controls, bone marrow stromal cells from 34 normal cases and 42 cases with leukemia were cultured long-term in vitro. Nonadherent cells (bone marrow hematopoietic cells) and amplified adherent cells (BMSC) were collected separately. Expressions of GATA-1 and GATA-2 genes were analyzed by using RT-PCR-ELISA; the semi-quantitative expression levels of GATA genes in the BMSCs from patients with leukemia were compared with normal controls. The results showed that expressions of GATA-1 and GATA-2 genes could be detected in the BMSCs and the bone marrow hematopoietic cells from both normal controls and the cases of leukemia. The expression ratio of GATA-1 in the BMSCs from acute lymphocytic leukemia (ALL) (85.7%) was similar to the normal controls (88.2%), whereas the expression ratios in BMSCs from acute myelocytic leukemia (AML) (55.6%) and chronic myelocytic leukemia (CML) (41.2%) were significant lower than the normal controls (P < 0.05). The rank of expression level of GATA-1 gene in the BMSCs was "ALL>AML>normal>CML". There was no difference in the expression level of GATA-2 gene within the BMSCs from normal controls and patients with leukemia. The ranks of expression levels of GATA-1 and GATA-2 genes in bone marrow hematopoietic cells were "AML>normal>ALL>CML" and "AML>CML>ALL>normal". The dominant expression of GATA-2 gene was found in the BMSCs from AML, CML or normal controls. It is inferred that the expressions of GATA-1 and GATA-2 genes in the BMSCs of normal controls and patients with leukemia may influence the regulation of hematopoiesis in the bone marrow stroma and it is worthy of further study to explore their roles in pathogenesis and development of leukemia.

Significant decrease of recent thymic output function in patients with severe benzene intoxication / 中国实验血液学杂志

The aim of the present study was to investigate the level of T-cell receptor excision DNA circles (TREC) in peripheral blood mononuclear cells (PBMNC) of patients with severe benzene poison, thereby to evaluate the content of naive T cells and the recent thymic output function. Quantitative detection of TREC in DNA of PBMNCs from 16 normal individuals and 8 cases with severe benzene poison was preformed by real-time PCR using TaqMan technique. The results showed that TREC level was 6.69 +/- 4.79/1 000 PBMNCs in normal individuals, however, significant decrease was shown in patients with severe benzene poison (1.03 +/- 0.44/1 000 PBMNCs, P < 0.01). The TREC level was persistently low in period of benzene poisoning, even if peripheral blood cell counts were at normal levels. In conclusion, the recent thymic output function is remarkably decreased in patients with severe benzene intoxication, that may obviously damage the T cell immune function.