Search

We report the discovery of a peculiar X-ray transient, EP240408a, by Einstein Probe (EP)and follow-up studies made with EP, Swift, NICER, GROND, ATCA and other ground-based multiwavelength telescopes. The new transient was first detected with Wide-field X-ray Telescope (WXT) on board EP on April 8th, 2024, manifested in an intense yet brief X-ray flare lasting for 12 s. The flare reached a peak flux of 3.9 × 10−9erg cm−2s−1in 0.5–4 keV, ∼300 times brighter than the underlying X-ray emission detected throughout the observation. Rapid and more precise follow-up observations by EP/FXT, Swiftand NICERconfirmed the finding of this new transient. Its X-ray spectrum is non-thermal in 0.5–10 keV, with apower-law photon index varying within 1.8–2.5. The X-ray light curve shows a plateau lasting for ∼4 d, followed by a steep decay till becoming undetectable ∼10 d after the initial detection. Based on its temporal property and constraints from previous EPobservations, an unusual timescale in the range of 7–23 d is found for EP240408a, which is intermediate between the commonly found fast and long-term transients. No counterparts have been found in optical and near-infrared, with the earliest observation at 17 h after the initial X-ray detection, suggestive of intrinsically weak emission in these bands. We demonstrate that the remarkable properties of EP240408a are inconsistent with any of the transient types known so far, by comparison with, in particular, jetted tidal disruption events, gamma-ray bursts, X-ray binaries and fast blue optical transients. The nature of EP240408a thus remains an enigma. We suggest that EP240408a may represent a new type of transients with intermediate timescales of the order of ∼10 d. The detection and follow-ups of more of such objects are essential for revealing their origin.

In this paper we describe the potential of the enhanced X-ray Timing and Polarimetry (eXTP) mission for studies related to accretion flows in the strong field gravity regime around both stellar-mass and supermassive black-holes. eXTP has the unique capability of using advanced “spectral-timing-polarimetry” techniques to analyze the rapid variations with three orthogonal diagnostics of the flow and its geometry, yielding unprecedented insight into the inner accreting regions, the effects of strong field gravity on the material within them and the powerful outflows which are driven by the accretion process. X-spinmeasurements

The Wide Field Survey Telescope (WFST) is a dedicated photometric surveying facility being built jointly by University of Science and Technology of China (USTC) and the Purple Mountain Observatory (PMO). It is equipped with a 2.5-meter diameter primary mirror, an active optics system, and a mosaic CCD camera with 0.73 gigapixels on the primary focal plane for high-quality image capture over a 6.5-square-degree field of view. The installation of WFST near the summit of Saishiteng mountain in the Lenghu region is scheduled in summer of 2023, and the operation is planned to start three months later. WFST will scan the northern sky in four optical bands (u, g, rand i) at cadences from hourly/daily in the deep high-cadence survey (DHS) program, to semi-weekly in the wide field survey (WFS) program. During a photometric night, a nominal 30 s exposure in the WFS program will reach a depth of 22.27, 23.32, 22.84, and 22.31 (AB magnitudes) in these four bands, respectively, allowing for the detection of a tremendous amount of transients in the low-zuniverse and a systematic investigation of the variability of Galactic and extragalactic objects. In the DHS program, intranight 90 s exposures as deep as 23 (u) and 24 mag (g), in combination with target of opportunity follow-ups, will provide a unique opportunity to explore energetic transients in demand for high sensitivities, including the electromagnetic counterparts of gravitational wave events, supernovae within a few hours of their explosions, tidal disruption events and fast, luminous optical transients even beyond redshift of unity. In addition, the final 6-year co-added images, anticipated to reach g≃ 25.8 mag in WFS or 1.5 mags deeper in DHS, will be of fundamental importance to general Galactic and extragalactic science. The highly uniform legacy surveys of WFST will serve as an indispensable complement to those of the Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST) that monitors the southern sky.

The Hot Universe Baryon Surveyor (HUBS) is a proposed space-based X-ray telescope for detecting X-ray emissions from the hot gas content in our universe. With its unprecedented spatially-resolved high-resolution spectroscopy and large field of view, the HUBS mission will be uniquely qualified to measure the physical and chemical properties of the hot gas in the interstellar medium, the circumgalactic medium, the intergalactic medium, and the intracluster medium. These measurements will be valuable for two key scientific goals of HUBS, namely to unravel the AGN and stellar feedback physics that governs the formation and evolution of galaxies, and to probe the baryon budget and multi-phase states from galactic to cosmological scales. In addition to these two goals, the HUBS mission will also help us solve some problems in the fields of galaxy clusters, AGNs, diffuse X-ray backgrounds, supernova remnants, and compact objects. This paper discusses the perspective of advancing these fields using the HUBS telescope.

We study the hard states of the black hole binary XTE J1550-564 during its 2000 outburst. In order to explain those states at their highest luminosities, L ~ 10% of the Eddington luminosity, LE, we propose a specific hot accretion flow model. We point out that the highest values of the hard-state L are substantially above the L that an advection-dominated accretion flow can produce, ~0.4a2LE, which is only ~3%-4% of LE even for a as high as 0.3. On the other hand, we successfully explain the hard states with L ~ 0.04-0.10 using the luminous hot accretion flow (LHAF) model. As 0.10LE is also roughly the highest luminosity an LHAF can produce, such agreement between the predicted and observed highest luminosities itself provides strong support for this model. We then study multiwaveband spectral variability during the 2000 outburst. In addition to the primary maxima in the optical light curves, secondary maxima were detected after the transition from the very high state to the hard state. We show that the secondary maxima are well modeled as synchrotron emission from a jet formed during the state transition. We argue that the absence of a corresponding secondary peak in the X-ray light curve indicates that the X-ray jet emission, regardless of its radiative process, synchrotron or Comptonization, is not important in the hard state as compared with the emission from the accretion flow.

Emission spectra of hot accretion disks characteristic of advection-dominated accretion flow (ADAF) models are investigated for comparison with the brightest ultraluminous source, X-1, in the galaxy M82. If the spectral state of the source is similar to the low-luminosity hard state of stellar mass black holes in our Galaxy, a fit to the Chandra X-ray spectrum and constraints from the radio and infrared upper limits requires a black hole mass in the range of 9 x 104-5 x 105 M. Lower black hole masses ([?]104 M) are possible if M82 X-1 corresponds to the high-luminosity hard state of Galactic black hole X-ray binary sources. Both of these spectrally degenerate hot accretion disk solutions lead to an intermediate-mass black hole interpretation for M82 X-1. Since these solutions have different spectral variability with X-ray luminosity and predict different radio/infrared emission, they could be distinguished by future off-axis Chandra observations or simultaneous sensitive radio/infrared detections.

The spectral energy distribution (SED) of TeV blazars peaks both at keV and TeV energies. The X-ray emission is generally believed to originate in the synchrotron emission from relativistic electrons (and positrons) in the jet of these sources, while the origin of the gamma-ray emission is still being debated. We report results from a systematic study of X-ray spectral variability of Mrk 421 and Mrk 501 during individual flares that last for several days, making use of some of the high-quality data that have recently become available. The X-ray spectra of the two sources fall on the opposite sides of the synchrotron peak of their respective SEDs, so they together may offer additional insights into the physical origin of X-ray variability. We modeled each of the time-resolved X-ray spectra over a single flare by adopting a homogeneous spatial distribution and an instantaneous power-law spectral distribution for the emitting particles. We focused on the variation of four key parameters: particle spectral index, maximum Lorentz factor, energy density, and magnetic field. While there is considerable degeneracy in the fits, we show that, in order to account for the X-ray spectral variability observed in Mrk 421, at least three of the parameters are required to vary in most cases, with the spectral index being one of them. The observations of Mrk 501 support the conclusion, although the quality of the data is not as good. We discuss the implications of the results.

The effectiveness of the thermal coupling of ions and electrons in optically thin, hot accretion flows is investigated in a phenomenological approach. In the limit of complete coupling, we focus on the one-temperature accretion flows around black holes. Based on a global analysis, the results are compared with two-temperature accretion flow models and with the observations of black hole sources. Many features of one- and two-temperature solutions are quite similar. That is, hot one-temperature solutions are found to exist for mass flow rates less than a critical value, i.e., img1.gif [?] 10a2img1.gifEdd, where img1.gifEdd = LEdd/c2 is the Eddington accretion rate. When img1.gif [?] 10-3a2img1.gifEdd, the viscous energy is mainly balanced by the advective cooling, i.e., the solution is in the advection-dominated accretion flow (ADAF) regime. On the other hand, when 10-3a2img1.gifEdd [?] img1.gif [?] 10a2img1.gifEdd, radiative cooling is effective and is mainly balanced by advective heating, placing the solution in the regime of luminous hot accretion flow (LHAF). When img1.gif [?] 10a2img1.gifEdd, the accretion flow collapses at a transition radius with only the standard optically thick and geometrically thin disk solution existing in the innermost regions. We have fitted the spectra of the two black hole sources with the one-temperature models, Sgr A* and XTE J1118+480, which have been examined successfully with two-temperature models. It is found that the one-temperature models do not provide acceptable fits to the multi-wavelength spectra of Sgr A* nor to XTE J1118+480 as a result of the higher temperatures characteristic of the one-temperature models. It is concluded that the thermal coupling of ions and electrons cannot be fully effective and that a two-temperature description is required.

Motivated by the recent discovery of a hierarchical X-ray flaring phenomenon in Mrk 421, we conducted a systematic search for X-ray flares from Mrk 501, another well-known TeV blazar, by making use of the rich RXTE archival database. We detected flares over a wide range of timescales, from months down to minutes, as in the case of Mrk 421. However, the flares do not seem to occur nearly as frequently in Mrk 501 as in Mrk 421 on any of the timescales. The flaring hierarchy also seems apparent in Mrk 501, suggesting that it might be common among TeV blazars. The results seem to imply a scale-invariant physical origin of the flares (large or small). The X-ray spectrum of the source shows a general trend of hardening toward the peak of long-duration flares, with indication of spectral hysteresis, which is often seen in TeV blazars. However, the data are not of sufficient quality to allow us to draw definitive conclusions about spectral variability associated with more rapid but weaker flares. We critically examine a reported subhour X-ray flare from Mrk 501, in light of intense background-flaring activity at the time of the observation, and concluded that the flare is likely an artifact. On the other hand, we did identify a rapid X-ray flare that appears to be real. It lasted only for about 15 minutes, during which the flux of the source varied by about 30%. Substructures are apparent in its profile, implying variabilities on even shorter timescales. Such rapid variabilities of Mrk 501 place severe constraints on the physical properties of the flaring region in the jet, and the constraints have serious implications for the emission models proposed for TeV blazars.

In Streptomyces venezuelae, four polyketide synthase (PKS) polypeptides encoded by pikAI-pikAIVare used to generate 10 and 12-membered macrocyclic structures, narbonolide and 10-deoxymethynolide. Sequence analysis suggests these genes are translationally coupled with downstream genes, pikAV(encoding a type II thioesterase), desVIII-desVI(encoding enzymes responsible for production of the final glycosylated products pikromycin, narbomycin, methymycin and neomethymycin) and desR(a resistance gene). Type II thioesterases have been suggested to have an editing function in polyketide biosynthesis and deletion of the corresponding genes often leads to decreased levels of polyketide production. Surprisingly an in-frame deletion of 687 bp of the 843 bp pikAVORF led to a strain SC1022 that produced normal yields of polyketide products, but only in the aglycone form. Plasmid-based expression of the desVIII-VIand desRin the SC1022 strain completely restored production of glycosylated products, despite the absence of a functional pikAVgene product. Under these conditions the PikAV TEII therefore does not play an important role in polyketide biosynthesis, and its function remains an enigma. These observations also demonstrate that the region of pikAVDNA deleted in strain SC1022 contains a transcription unit essential for expression of the desgenes. A sequence alignment of PikAV with members of the highly conserved type II thioesterases revealed a short divergent region at the carboxy terminus, suggesting a region of pikAVthat might contain such a transcription unit. DNA containing this region of pikAVwas shown to be able to increase plasmid-based expression of both crotonyl CoA reductase gene (ccr)and the erythromycin resistance gene (ermE)in S. venezuelae.

Pikromycin-related macrolides have recently attracted significant research interest because they are structurally related to the semisynthetic ketolide antibiotics that have demonstrated promising potential in combating multi-drug-resistant respiratory pathogens. Cloning and in-depth studies of the pikromycin biosynthetic gene cluster from Streptomyces venezuelaehave led to new avenues in modular polyketide synthases, deoxysugar biosynthesis, cytochrome P450 hydroxylase, secondary metabolite gene regulation, and antibiotic resistance. Moreover, the knowledge and tools used for these studies are proving to be valuable in the development of advanced technologies for combinatorial biosynthesis of new macrolide antibiotics. This review summarizes these new developments and introduces S. venezuelaeas a powerful new system for secondary metabolite pathway engineering from bench-top genetic manipulation to product fermentation.

We report an interesting case of Malignant Histiocytosis (MH) with polyploid clones characterized by i(17q) and t(9; 22) translocation. A 47-year-old man had lymphadenopthy, splenomegaly and leukopenia at presentation. Bone marrow (BM) cytology showed 10.5% abnormal histiocytes. Karyotypic analyses with R- and G-banding techniques on BM cells revealed complex abnormalities: 88, XXYY, add(2) (p25), -4, -8, -11, i(17q), -21[4]/89, idem, t(9; 22) (q34; q11), +22[26]/46, XY [47], of which, t(9; 22) was confirmed by fluorescence in situhybridization using a chromosome 22 paint wcp 22+. This patient was treated with interferon-alpha and COP regimen. 10 months later he achieved a complete hematologic and cytogenetic remission (CR). However, relapse occurred one year after achieving CR. At that time, cytogenetic examination showed a new polyploid clone characterized by add(1) (p36), add(2) (p25), -4, -8, t(9; 22), -11, i(17q), -21, +22 in addition to the other two polyploid clones observed previously. RT-PCR indicated that the BCR/ABL transcript (165bp) observed in classic chronic myeloid leukemia, was present, MH with t(9; 22) has not previously been described in the literature. This case may be the first one of MH with t(9; 22), and is likely a secondary event.

No relevant conflicts of interest to declare.

We report the discovery of an X-ray group of galaxies located at a high redshift of $ z$$ =$1.61 in the Chandra Deep Field South. Based on 4 Ms Chandra data, the group is first identified as an extended X-ray source. We have used a wealth of deep multi-wavelength data to identify the optical counterpart—our red sequence finder detects a significant over-density of galaxies at $ z$$ \sim$1.6. The brightest group galaxy is spectroscopically confirmed at $ z$$ =$1.61, based on published spectroscopic redshifts. Using this as a central redshift of the group, we measure an X-ray luminosity of $ L_{0.1{\rm-}2.4\rm keV}$$ =$(1.8 $ \pm$0.6) $ \times$10$ ^{43}$erg s$ ^{-1}$, which then translates into a group mass of (3.2 $ \pm$0.8) $ \times$10$ ^{13}$$ M_{\odot}$. This is the lowest-mass group ever confirmed at $ z$$ >$1.5. Deep optical–nearIR images from CANDELS reveal that the group exhibits a surprisingly prominent red sequence, and most of the galaxies are consistent with a formation redshift of $ z_{\rm f}$$ =$3. A detailed analysis of the spectral energy distributions of the group member candidates confirms that most of them are indeed passive galaxies. Furthermore, their structural parameters measured from near-IR CANDELS images show that they are morphologically early-type. The newly identified group at $ z$$ =$1.61 is dominated by quiescent early-type galaxies, and the group appears to be similar to those in the local Universe. One possible difference is the high fraction of AGN—38$ ^{+23}_{\hskip.4mm-20}$% of the bright group member candidates are AGN, which might indicate a role for AGN in the quenching of star formation. However, a statistical sample of high-$ z$groups is needed to draw a general picture of groups at this redshift. Such a sample will hopefully be available in near-future surveys.

No relevant conflicts of interest to declare.

Abstract 1683

To determining the clonal origin of dysplatic cells in Myelodysplastic syndromes (MDS) .Karyotypic analyses of bone marrow cells using R-banding technique were carried out to determine the chromosomal abnormalities. Interphase fluorescence in situ hybridization (FISH) and morphologic analysis of bone marrow aspirates were performed in the same cells to investigate the clonal origin of dysplatic cells in 8 MDS patients.All patients had clonal karyotypic abnormalities: simple abnormality in 1 patient, complex abnormalities in 6 patients, coexistent of two unrelated clones in 1 patient. Most of dysplastic cells in 7 of 8 MDS patients derived from neoplasia clone while 1 patient had a reverse result,no matter what cell lineage was involved. Some of non-dysplastic cells of all patients derived from malignant clone; in 7 patients, the proportion of dysplastic cells in malignant clone were significantly higher than that of non- malignant clone.Most of dysplastic cells in MDS derived from malignant clones, while the minority of them derived from non-malignant clones. Thus, it is reasonable to expect that in most cases myelodysplasia is present in malignant clone and can be taken as an important diagnostic evidence for MDS.No relevant conflicts of interest to declare.

No relevant conflicts of interest to declare.

Abstract 4864

Abstract 4858

To verify whether CpG-oligodeoxynucleotide (CpG-ODN) can raise the detection rate of the karyotypic abnormalities in chronic lymphocytic leukemia (CLL).The bone marrow (BM) or peripheral blood (PB) cells from 57 cases of CLL were collected and cultured with CpG-ODN DSP30+interleukin-2 (IL-2), phytohemagglutinin (PHA), pokeweed(PWM) or IL-2, respectively. 5 days later cells were harvested for chromosome preparation. Karyotypic analysis was performed using R banding technique. Panel fluorescence in situ hybridization (FISH) was carried out on 19 cases of CLL with normal karyotype using following probes: Cen12, D13S25, Rb1, ATM, P53, MYB and IgH. Genomic DNA from 21 cases of them was extracted from BM or PB. The immunoglobulin variable heavy chain (IgVH) were amplified by polymerase reaction (PCR) and sequenced. CD38 and ZAP70 expressions in leukemic cells were determined by flow cytometry (FCM).The detection rate of karyotypic abnormalities in CpG-ODN+IL-2 group (43.85%) was obviously higher than PHA (15.09%), PWM (17.31%) and IL-2 (3.13%) groups (P<0.01). 52 karyotypic abnormalities were found. Among them, trisomy12 (+12) or +12 with other abnormalities were the most common, while translocations were the most frequent structural abnormalities including 3 unbalanced and 11 balanced translocations among which 7 had 14q32 rearrangements. 13 cases showed one or more abnormalities on FISH examination including trisomy12 and P53 deletion each in one case, IgH rearrangement and partial deletion each in one case, 13q14.3 deletion in 11 cases of which 5 cases also had Rb1 deletion, one case had Rb1 partial deletion. No cases with ATM or MYB deletions were found. IgVH mutation was detected in 10/21 cases by PCR and sequencing. FCM showed 10/45 cases expressed CD38, while 11/27 cases expressed ZAP70. Among 26 cases examined for CD38 and ZAP70 expressions simultaneously, 5 cases were CD38+ZAP70+, 13 cases CD38-ZAP70-, 6 cases CD38-ZAP70+, 2 cases CD38+ZAP70-, respectively. Statistics disclosed a correlation between complex karyotype and IgVH without mutation, but no association between karyotype and CD38 or ZAP70 expression.CpG-ODN immunostimulation can obviously raise the detection rate of abnormal karyotypes, especially balanced and unbalance translocations in CLL. FISH is important complement to conventional karyotypic analysis, the combination of both methods can provide more comprehensive genetic information for CLL.No relevant conflicts of interest to declare.

No relevant conflicts of interest to declare.

Abstract 4242

Abstract 4383

We report the establishment of a novel cell line from a patient with acute myelocytic leukemia. The initial growth of this cell line was dependent on the presence of the stromal cell and cytokine interleukine 3. Subsequently, a stroma and cytokine-independent cell line was established, named SH-2. The cell line has proliferated continuously in vitro for more than 24 months. The SH-2 cell line showed identical chromosomal alterations to that of the initial bone marrow aspiration specimen, demonstrated a t(16;17))(q24;q12) translocation accompanied by deletions of y and 17 and triple 19.Chromosome painting FISH and Multi-FISH conformed the karyotype.SH-2 cells expressed myeloid antigens CD13, CD33 and MPO, SH-2 co-expressed NK markers CD16 and CD56. The loss of one p53 allele were proven by chromosome painting, FISH. A point mutation of CAG to CAT at codon 576 of extron 5 in another p53 allele was found by direct sequencing of DNA. Neither Epstein-Barr virus nor mycoplasma was not detected in SH-2 cells. DNA fingerprinting confirmed the authenticity of the cell line. Cytokines of GM-CSF,IL-3,IL-6,SCF,IL-4 and IL-5 can improve the proliferation of SH-2. SH-2 has colony formality and tumorigenic capacity in nude mice. The breakpoints of chromosomes 16 and 17 were localized RP11-356C4(16q24.3)and between BAC clone RP1-161P9 and RP11-47L3 corresponding to 17q12. The establishment of an myelocytic leukemia cell line with t(16;17)(q24;q12) could be valuable for the study of leukemogenesis and for the research of cloning the new gene involved in the t(16;17)(q24;q12) translocation.

Translocations involving 21q22 are commonly observed in both de novo and therapy-related acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). They often result in the disruption of RUNX1 and give rise to fusion genes consisting RUNX1 and different partner genes which contribute to leukemogenesis. At present, at least 21 such translocations have been reported in the literature. We report here two novel translocations involving the RUNX1 gene: t(1;21)(q12;q22) in a 53-year-old female with AML-M5b and t(11;21)(q13;q22) in a 65-year-old male with AML-M2. The abnormalities revealed by R-banding karyotypic analysis were confirmed by interphase and metaphase fluorescence in situ hybridization (FISH), chromosome painting (CP), and M-FISH.

As a newly identified cytogenetic abnormality, idic(20q−) has been reported in thirteen cases of myelodysplastic syndrome (MDS), one case of chronic myelomonocytic leukemia, and one case of acute myeloid leukemia (AML) since 2004. Here we report additional seven cases consisting of 3 MDS, 2 AML and 2 acute lymphocytic leukemia (ALL). A karyotype analysis using R-banding technique revealed an i(20q−) as a sole anomaly in 5 of them and as a secondary change in other 2 cases: one was a B-cell ALL whose leukemic cells at presentation had a karyotype of 45, XY, dic(9;20)(p11;q11). However, an idic(20q−) was found coexistent with the dic(9;20) as relapse; another was a Ph positive ALL whose leukemic cells simultaneously contained t(9;22)(q34;q11) and idic(20q−). A series of FISH using multiple probes such as the centromeric probes specific for chromosomes 9 and 20, the subtelomeric probe for 20q, the locus-specific probe for 20q12, the whole chromosome paint probes for chromosomes 9 and 22 and the translocation probe for t(9;22) demonstrated the idic(20q−) to be actually a der(20)idic(20)(p11)del(20)(q11q13), confirmed the dic(9;20)(p11;q11) in case 6 and revealed a BCR/ABL fusion gene in case 7. Among them, 2 MDS patients survived and anemic except one lost to follow-up, 2 AML and 2 ALL patients did not obtain complete remission and died with short survivals. Our study brings the total number of cases with idic(20q−) to 22 and suggests that the disease spectrum of idic(20q−) is not restricted to myeloid disorders, and it also includes ALL.

Translocations involving 21q22 are commonly observed in both de novo and therapy-related acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). They often result in the disruption of RUNX1and give rise to fusion genes consisting RUNX1and different partner genes which contribute to leukemogenesis. At present, at least 21 such translocations have been reported in the literature. We report here two novel translocations involving the RUNX1gene: t(1;21)(q12;q22) in a 53-year-old female with AML-M5b and t(11;21)(q13;q22) in a 65-year-old male with AML-M2. The abnormalities revealed by R-banding karyotypic analysis were confirmed by interphase and metaphase fluorescence in situ hybridization (FISH), chromosome painting (CP), and M-FISH.

We report the establishment of a novel cell line from a patient with acute myelocytic leukemia. The initial growth of this cell line was dependent on the presence of the stromal cell and cytokine interleukine 3. Subsequently, a stroma and cytokine-independent cell line was established, named SH-2. The cell line has proliferated continuously in vitro for more than 24 months. The SH-2 cell line showed identical chromosomal alterations to that of the initial bone marrow aspiration specimen, demonstrated a t(16;17))(q24;q12) translocation accompanied by deletions of y and 17 and triple 19.Chromosome painting FISH and Multi-FISH conformed the karyotype.SH-2 cells expressed myeloid antigens CD13, CD33 and MPO, SH-2 co-expressed NK markers CD16 and CD56. The loss of one p53 allele were proven by chromosome painting, FISH. A point mutation of CAG to CAT at codon 576 of extron 5 in another p53 allele was found by direct sequencing of DNA. Neither Epstein-Barr virus nor mycoplasma was not detected in SH-2 cells. DNA fingerprinting confirmed the authenticity of the cell line. Cytokines of GM-CSF,IL-3,IL-6,SCF,IL-4 and IL-5 can improve the proliferation of SH-2. SH-2 has colony formality and tumorigenic capacity in nude mice. The breakpoints of chromosomes 16 and 17 were localized RP11-356C4(16q24.3)and between BAC clone RP1-161P9 and RP11-47L3 corresponding to 17q12. The establishment of an myelocytic leukemia cell line with t(16;17)(q24;q12) could be valuable for the study of leukemogenesis and for the research of cloning the new gene involved in the t(16;17)(q24;q12) translocation.

As a newly identified cytogenetic abnormality, idic(20q−) has been reported in thirteen cases of myelodysplastic syndrome (MDS), one case of chronic myelomonocytic leukemia, and one case of acute myeloid leukemia (AML) since 2004. Here we report additional seven cases consisting of 3 MDS, 2 AML and 2 acute lymphocytic leukemia (ALL). A karyotype analysis using R-banding technique revealed an i(20q−) as a sole anomaly in 5 of them and as a secondary change in other 2 cases: one was a B-cell ALL whose leukemic cells at presentation had a karyotype of 45, XY, dic(9;20)(p11;q11). However, an idic(20q−) was found coexistent with the dic(9;20) as relapse; another was a Ph positive ALL whose leukemic cells simultaneously contained t(9;22)(q34;q11) and idic(20q−). A series of FISH using multiple probes such as the centromeric probes specific for chromosomes 9 and 20, the subtelomeric probe for 20q, the locus-specific probe for 20q12, the whole chromosome paint probes for chromosomes 9 and 22 and the translocation probe for t(9;22) demonstrated the idic(20q−) to be actually a der(20)idic(20)(p11)del(20)(q11q13), confirmed the dic(9;20)(p11;q11) in case 6 and revealed a BCR/ABLfusion gene in case 7. Among them, 2 MDS patients survived and anemic except one lost to follow-up, 2 AML and 2 ALL patients did not obtain complete remission and died with short survivals. Our study brings the total number of cases with idic(20q−) to 22 and suggests that the disease spectrum of idic(20q−) is not restricted to myeloid disorders, and it also includes ALL.

Inv(16) has been reported in 10%~12% of acute myeloid leukemia (AML), mostly being associated with the M4Eo subtype, and is associated with a relatively favorable outcome. However, it is a cryptic rearrangement and often difficult to recognize in conventional cytogenetics (CC). Trisomy 22 is an uncommon karyotypic aberration in AML and is often associated with inv(16)(p13q22). In order to explore the value of trisomy 22 in the diagnosis of AML with inv(16), dual-color interphase fluorescence in situ hybridization (FISH) was performed in 19 AML cases with trisomy 22 abnormality. The probe was two-color break apart probe for CBFb with SpectrumRed on the centromeric side and SpectrumGreen on the telomeric side. And the results were compared with that of R-banding CC. CC did not reveal inv(16) in any of the 19 AML with trisomy 22, but FISH analysis showed inv(16) in 11 cases and del(16)(q22) in one case. Among 11 cases with inv(16), 9 were trisomy 22 as the sole abnormality, one was complicated with trisomy 8, and one was del(16)(q22). Four AML patients with trisomy 22 and inv(16) were analyzed by multiplex FISH (M-FISH) which revealed trisomy 22 only. This study further confirmed that trisomy 22 as the sole abnormality can be regarded as an important marker for the inv(16) in AML.

Background Plasma cell leukemia (PCL) is a rare malignant plasma cell disorder that usually carries an aggressive course with a rapidly fatal outcome. Cytogenetic studies performed on plasma cell disorder are scarce and difficult because of the low proliferation rate of plasma cells. Fluorescence in situ hybridization (FISH) analysis is an attractive alternative for evaluation of numerical and structural chromosomal changes in PCL. Methods Interphase FISH (I-FISH) and two different specific probes for the regions containing 13q14.3 (D13S319) or 14q32 (IGHC/IGHV) were used to detect 13q14 deletion [del(13q14)] or IgH rearrangement in 22 PCL patients. For patients with IgH rearrangement, probes for IgH(JH) and 11q13 (CCND1) or 4p16 (FGFR3) were used to detect t(11;14)(q13;q32) or t(4;14)(p16;q32). Results Molecular cytogenetic aberrations were found in 19 of 22 (86.4%) PCL patients. Del(13q14) was detected in 13 cases (59.1%), and IgH rearrangement in 17 (77.3%) patients including 7 with t(11;14) and 3 with t(4;14). 14q32 rearrangement and 13q14 deletion were found concurrently in 11 cases (50%). Conclusions Chromosomal abnormalities are frequent in PCL. The most frequent aberrations among the cases was the 14q32 rearrangement and 13q14 deletion. I-FISH technique is useful to detect molecular cytogenetic aberrations and should be used in the routine evaluation of PCL.

Background Plasma cell leukemia (PCL) is a rare malignant plasma cell disorder that usually carries an aggressive course with a rapidly fatal outcome. Cytogenetic studies performed on plasma cell disorder are scarce and difficult because of the low proliferation rate of plasma cells. Fluorescence in situ hybridization (FISH) analysis is an attractive alternative for evaluation of numerical and structural chromosomal changes in PCL.

Inv(16) has been reported in 10%~12% of acute myeloid leukemia (AML), mostly being associated with the M4Eo subtype, and is associated with a relatively favorable outcome. However, it is a cryptic rearrangement and often difficult to recognize in conventional cytogenetics (CC). Trisomy 22 is an uncommon karyotypic aberration in AML and is often associated with inv(16)(p13q22). In order to explore the value of trisomy 22 in the diagnosis of AML with inv(16), dual-color interphase fluorescence in situ hybridization (FISH) was performed in 19 AML cases with trisomy 22 abnormality. The probe was two-color break apart probe for CBFb with SpectrumRed on the centromeric side and SpectrumGreen on the telomeric side. And the results were compared with that of R-banding CC. CC did not reveal inv(16) in any of the 19 AML with trisomy 22, but FISH analysis showed inv(16) in 11 cases and del(16)(q22) in one case. Among 11 cases with inv(16), 9 were trisomy 22 as the sole abnormality, one was complicated with trisomy 8, and one was del(16)(q22). Four AML patients with trisomy 22 and inv(16) were analyzed by multiplex FISH (M-FISH) which revealed trisomy 22 only. This study further confirmed that trisomy 22 as the sole abnormality can be regarded as an important marker for the inv(16) in AML.

The complex chromosome abnormalities (CCAs) were one of the most important poor prognostic risk factors in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). Chromosome analysis using classical cytogenetic banding techniques fails to completely resolve complex karyotypes and cryptic translocations. The technique of multiplex fluorescence in situ hybridization (M-FISH) allow for the simultaneous visualization of all chromosomes of a metaphase in a single hybridization step and thereby enable to comprehensively analyze complex karyotypes and the identification of new and cryptic translocations. To investigate the value of M-FISH in the detection of complex karyotypic abnormalities of AML and MDS. M-FISH was used in combination with interphase-FISH to study 24 cases of AML and MDS with CCAs showed by R-banding of conventional cytogenetics (CC). In 14 cases of AML with CCAs, 4 gains of whole chromosome and 4 losses of whole chromosome were confirmed by M-FISH, while 12 losses of whole chromosome were revised as derivative chromosomes resulted from various structural aberrations. 26 derivative chromosomes and 19 marker chromosomes were characterized precisely by M-FISH. Most of them were unbalanced translocations, including 2 complex t(8;21), which have not been previously described:t(8;21), der(8) t(8;21) (8pter→8q22::21q22→21qter), der(21) t(8;21;8) (8qter→ 8q22::21p13→ 21q22::8q22→ 8qter) and t(21;8;18;1), der(8) t(8;21) (8pter→ 8q22::21q22→ 21qter), der(21) t(21;8;18;1) (21p13→ 21q22::8q22→ 8q24::18?::1q?q?). In 10 cases of MDS, 37 kinds of structural rearrangements were detected by M-FISH including insertion, deletion, translocation and derivative chromosomes, and among them 34 kinds were unbalanced rearrangements, only 3 were balanced rearrangements including t(6;22)(q21;q12), t(9;19)(q13;p13) and t(3;5)( ?;?), 7 abnormalities were never reported before. The CCAs invloved nearly all chromosomes, of which the chromosome 17, 5 and 7 were invloved more frequent than the rest. Chromosomes 5, 17, 7 were involved in 15 cases (62.5%), 12 cases (50%) and 6 cases (25%) respecrively. We conclude that M-FISH could refine CCAs of AML and MDS patients, find or correct the missed or misidentified aberrations by CC analysis. Our findings confirm that M-FISH is a powerful tool to characterize complex karyotypes in AML and MDS.

Objective To explore the inducing differentiation and apoptosis in a novel human acute monocytic leukemic cell line SHI-1. Methods Cell morphological analysis, NBT reduction test, the expression of CD11b and CD14, cell cycle analysis and binding of annexinV tested by FCM, DNA electrophoresis were performed to evaluate whether tributyrin (TB), arsenic trioxide (As2O3), and 12-O-tetradecanoyl-phorbol-13 acetate (TPA) could induce the differentiation and apoptosis in the SHI-1 cell line. Results The results of morphological analysis, NBT reduction test, and FCM assay showed that TB could induce differentiation of SHI-1 cells. The SHI-1 cell line presented typical apoptotic evidences including morphology features, DNA ladders and the increased apoptotic rate determined by FCM. Moreover, the SHI-1 cell line presented typical apoptotic morphology after being treated with As2O3. The apoptotic rate of the SHI-1 cell line treated with As2O3 was increased determined by FCM. The expression level of CD14 was upregulated while that of CD11b was unchanged in the SHI-1 cell line. Most of the SHI-1 cells adhered to the flask after being treated with TPA for 24 hours. Conclusions TB may produce dual effects of differentiation and apoptosis. The cell line could be induced to differentiation partially or apoptosis after being treated with 0.5μM, 1.0μM, and 2.0μM As2O3. TPA could induce differentiation and adhesion of the SHI-1 cell line.

Objective

Objective Monitoring of minimal residual disease (MRD) and cellular chimerism in patients with hematopoietic malignancies after allogeneic hematopoietic stem cell transplantation(allo-HSCT).

The most frequent chromosomal abnormalities in B-cell chronic lymphocytic leukaemia (B-CLL) are deletions on 13q14 and 17p13, trisomy 12 and 14q32 rearrangement. Conventional metaphase cytogenetic analysis underestimates the frequency of specific chromosome aberrations in B-CLL due to the low rate of spontaneous mitoses and poor response to mitogen stimulation. The aim of this study was to investigate the incidence of chromosomal changes in bone marrow or peripheral blood cells (or both) of B-CLL patients using a molecular cytogenetic method, interphase fluorescence in situ hybridization (I-FISH). Probes for 13q14 (D13S319), 17p13 (P53 gene), the centromere of chromosome 12 (D12Z3) and 14q32 (Ig10 and Y6) were applied to detect chromosomal aberrations on bone marrow and peripheral blood smears from 83 B-CLL patients (60 male, 23 female,). Molecular cytogenetic aberrations were found in 60 (72.3%) cases, and 8 (9.6%) patients showed two kinds of abnormalities. The most frequent abnormalities detected in our patients was deletions of 13q14 in 34 cases (41.0%), followed by trisomy of chromosome 12 in 16 patients (19.3%), deletions of 17p13 in 10 patients (12%) and 14q32 rearrangement in 8 patients (9.6%). Statistical analyses were performed to correlate the molecular cytogenetic findings with Binet stages. No apparent differences in distribution were noted for anomalies del(13q14), del(17p13), +12 or 14q32 rearrangement among patients with various Binet stages. FISH was found to be a more rapid, exact and sensitive technique for the analysis of chromosome aberrations in CLL. FISH could provide accurate information of molecular cytogenetics for CLL.

Objective Monitoring of minimal residual disease (MRD) and cellular chimerism in patients with hematopoietic malignancies after allogeneic hematopoietic stem cell transplantation(allo-HSCT). Methods From May 2001 to June 2005, seventy four patients were received allo-HSCT. Including 50 Males and 24 females. 41 patients received sibling HLA-matched BMT, 7 patients received un-related BMT, 9 patients received Nonmyeloablative stem cell transplantation (NST), 14 patients received related haploidentical transplantation and 3 patients received allo-PBSCT. Among them, 45 patients were diagnosed with CML, 13 patients with AML, 14 patients with ALL, one patient with Multiple myeloma and one patient with malignant lymphoma. Chimerism and MRD were monitored using X and Y specific centromeric probes or gene probes for BCR/ABL, MLL and AML1/ETO by fluorescence in situ hybridization (FISH),1000 cells were analysised. Results Among 18 patients, received sex-matched transplant, we did not found the former chromosome rearrangements in 14 patients after transplantation, MRD were detected in 17% and 10% of cells in two patients, MRD were decreased from 10% to 1% of cells after the reduction of the dose of immunotherapy in one patient four month later, the patient was still in remission one year after transplantation. Another patient died of sever GVHD after the reduction of immunotherapy. 2 patients were found to have the former chromosomal rearrangement 1 and 4 month after transplantation respectively who did not achieve remission after chemotherapy and died 3 and 5 months respectively after transplantation. Over 99% donor chimerisms were found in 44 patients on day 25, donor cells were at a low level (96.2%~98.7) in 7 patients on day 25, and increased over 99% on day 180, they were in remission without relapse. The donor chimerisms decreased gradually in 6 patients, host cells were found over 20 cells, 3 patients showed cytogenetic or hematologic bone marrow relapse, two patients died of sever GVHD after the reduction of cyclosporine A, Over 99% donor chimerisms was achieved in one patient. Conclusion FISH could play a pivotal role in the detection of MRD and chimerism. It is helpful to the evaluation of graft and relapse, to the guide of implement of early immunotherapy.

The complex chromosome abnormalities (CCAs) were one of the most important poor prognostic risk factors in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). Chromosome analysis using classical cytogenetic banding techniques fails to completely resolve complex karyotypes and cryptic translocations. The technique of multiplex fluorescence in situ hybridization (M-FISH) allow for the simultaneous visualization of all chromosomes of a metaphase in a single hybridization step and thereby enable to comprehensively analyze complex karyotypes and the identification of new and cryptic translocations. To investigate the value of M-FISH in the detection of complex karyotypic abnormalities of AML and MDS. M-FISH was used in combination with interphase-FISH to study 24 cases of AML and MDS with CCAs showed by R-banding of conventional cytogenetics (CC). In 14 cases of AML with CCAs, 4 gains of whole chromosome and 4 losses of whole chromosome were confirmed by M-FISH, while 12 losses of whole chromosome were revised as derivative chromosomes resulted from various structural aberrations. 26 derivative chromosomes and 19 marker chromosomes were characterized precisely by M-FISH. Most of them were unbalanced translocations, including 2 complex t(8;21), which have not been previously described:t(8;21), der(8) t(8;21) (8pter→8q22::21q22→21qter), der(21) t(8;21;8) (8qter→ 8q22::21p13→ 21q22::8q22→ 8qter) and t(21;8;18;1), der(8) t(8;21) (8pter→ 8q22::21q22→ 21qter), der(21) t(21;8;18;1) (21p13→ 21q22::8q22→ 8q24::18?::1q?q?). In 10 cases of MDS, 37 kinds of structural rearrangements were detected by M-FISH including insertion, deletion, translocation and derivative chromosomes, and among them 34 kinds were unbalanced rearrangements, only 3 were balanced rearrangements including t(6;22)(q21;q12), t(9;19)(q13;p13) and t(3;5)( ?;?), 7 abnormalities were never reported before. The CCAs invloved nearly all chromosomes, of which the chromosome 17, 5 and 7 were invloved more frequent than the rest. Chromosomes 5, 17, 7 were involved in 15 cases (62.5%), 12 cases (50%) and 6 cases (25%) respecrively. We conclude that M-FISH could refine CCAs of AML and MDS patients, find or correct the missed or misidentified aberrations by CC analysis. Our findings confirm that M-FISH is a powerful tool to characterize complex karyotypes in AML and MDS.

The most frequent chromosomal abnormalities in B-cell chronic lymphocytic leukaemia (B-CLL) are deletions on 13q14 and 17p13, trisomy 12 and 14q32 rearrangement. Conventional metaphase cytogenetic analysis underestimates the frequency of specific chromosome aberrations in B-CLL due to the low rate of spontaneous mitoses and poor response to mitogen stimulation. The aim of this study was to investigate the incidence of chromosomal changes in bone marrow or peripheral blood cells (or both) of B-CLL patients using a molecular cytogenetic method, interphase fluorescence in situ hybridization (I-FISH). Probes for 13q14 (D13S319), 17p13 (P53 gene), the centromere of chromosome 12 (D12Z3) and 14q32 (Ig10 and Y6) were applied to detect chromosomal aberrations on bone marrow and peripheral blood smears from 83 B-CLL patients (60 male, 23 female,). Molecular cytogenetic aberrations were found in 60 (72.3%) cases, and 8 (9.6%) patients showed two kinds of abnormalities. The most frequent abnormalities detected in our patients was deletions of 13q14 in 34 cases (41.0%), followed by trisomy of chromosome 12 in 16 patients (19.3%), deletions of 17p13 in 10 patients (12%) and 14q32 rearrangement in 8 patients (9.6%). Statistical analyses were performed to correlate the molecular cytogenetic findings with Binet stages. No apparent differences in distribution were noted for anomalies del(13q14), del(17p13), +12 or 14q32 rearrangement among patients with various Binet stages. FISH was found to be a more rapid, exact and sensitive technique for the analysis of chromosome aberrations in CLL. FISH could provide accurate information of molecular cytogenetics for CLL.