[Efficacy of off-pump minimally invasive via a single left intercostal space incision compared with median sternotomy multi-vesselcoronary artery bypass grafting]

Objective: To compare the efficacy of off-pump minimally invasive cardiac surgery (MICS) via a single left intercostal space incision with median sternotomy multi-vesselcoronary artery bypass grafting (CABG). Methods: Patients who were diagnosed with multi-artery coronary artery disease (CAD) in the Ward 10 of the Department of Cardiac Surgery, Beijing Anzhen Hospital Affiliated to Capital Medical University and underwent CABG from July 2019 to January 2022 were retrospectively collected. All the patients were divided into MICS group and conventional CABG group according to the surgical methods. The perioperative outcomes were compared between thetwo groups, including intraoperative blood loss, postoperative 24 h thoracic drainage volume, ventilation duration, length of stay (LOS) in intensive care unit (ICU) and total LOS in hospital. Intraoperative blood flow of graft vesselswas measured by transit-time flow measurement (TTFM) after vascular anastomosis, and mean flow (MF) and pulsatile index (PI) were compared between the two groups. Results: A total of 444 patients were in the final analysis, with 351 males and 93 females, and the mean age of (62.0±8.9) years. There were 179 patients in MICS group and 265 cases in conventional CABG group, respectively. There were no statistically significant differences in the preoperative profiles between the two groups (all P>0.05) except that younger age [(60.7±9.3) years vs (62.8±8.5) years, P=0.017] and lower proportion of female [10.1% (18/179) vs 28.3% (75/265), P<0.001] were detected in MICS group. Likewise, there was no significant difference in the number of graft vessels between MICS group (3.18±0.74) and conventional CABG group (3.28±0.86) (P=0.234). Compared with those in conventional CABG group, patients in MICS group showed longer operation duration [ (5.10±1.09) h vs (4.33±0.86) h], fewer intraoperative blood loss [500 (200, 700) ml vs 700 (600, 900) ml], fewer postoperative 24 h thoracic drainage volume [300 (200, 400) ml vs 400 (250, 500) ml], shorter postoperative ventilation duration [15.0 (12.0, 17.0) h vs 16.5 (12.5, 19.0) h, P<0.001], LOS in ICU [18.0 (15.0, 20.0) h vs 20.0 (16.0, 23.0) h, P<0.001] and total LOS in hospital [(12.6±2.7) d vs (14.5±3.9) d, P<0.001]. MI and PI of graft vessels were similar between the two groups (both P>0.05). Moreover, there were no significant differences in major perioperative complications (i.e., repeat thoracotomy, incision infection, stroke) and mortality between the two groups (all P>0.05). Conclusion: MICS is an alternative treatment for patients with multi-vessel CAD with better perioperative outcomes compared with conventional CABG.

Psychological trauma, posttraumatic stress disorder and trauma-related depression: A mini-review

There are various types of traumatic stimuli, such as catastrophic events like wars, natural calamities like earthquakes, and personal trauma from physical and psychological neglect or abuse and sexual abuse. Traumatic events can be divided into type I and type II trauma, and their impacts on individuals depend not only on the severity and duration of the traumas but also on individuals’ self-evaluation of the traumatic events. Individual stress reactions to trauma include posttraumatic stress disorder (PTSD), complex PTSD and trauma-related depression. Trauma-related depression is a reactive depression with unclear pathology, and depression occurring due to trauma in the childhood has gained increasing attention, because it has persisted for a long time and does not respond to conventional antidepressants but shows good or partial response to psychotherapy, which is similar to the pattern observed for PTSD. Because trauma-related depression is associated with high risk of suicide and is chronic with a propensity to relapse, it is necessary to explore its pathogenesis and therapeutic strategy.

Structural maintenance of chromosomes 2 is identified as an oncogene in bladder cancer in vitro and in vivo

Taurine upregulated gene 1 (TUG1) has been found to promote bladder cancer cell growth in our recent research. In this study, TUG1-depleted bladder cancer cells were used to identify potent players in bladder cancer. Human gene expression arrays were used for transcriptome profiling of TUG1-depleted bladder cancer cells. Cell proliferation was analyzed by MTT assay. Cell apoptosis and cell cycle were analyzed by flow cytometry. Colony formation assay was used to observe the changes of colony formation rates. Xenograft formation assay was performed in nude mice. Immunohistochemical staining was used to test the gene expression levels in tissues from bladder cancer patients. We found that deregulated genes were strongly enriched in cell cycle or pathways in cancer in TUG1-depleted bladder cancer cells. Structural maintenance of chromosomes 2 (SMC2) was inhibited after TUG1 knockdown. The depletion of TUG1 or SMC2 led to G2/M phase arrest in bladder cancer cells. SMC2 depletion inhibited bladder cancer cell proliferation, promoted apoptosis, decreased colony formation, and reduced tumor growth in xenograft nude mice. Overexpression of SMC2 restored the growth of TUG1-depleted cells. The expression levels of SMC2 were higher in human bladder cancer tissues than that in paired normal tissues. Our data suggest that SMC2 is an oncogene in bladder cancer and depletion of SMC2 might have potential therapeutical significance in bladder cancer.

Characterization of agronomic and quality traits and HSW-G5 compositions from the progenies of common wheat (Triticum aestivum L.) with different protein content

High molecular weight glutenin subunits (HMW-GS) play an essential role in wheat processing quality. In this study, we evaluated the genetic pattern with HMW-GS composition between generations and examined whether agronomic and quality traits were correlated with each other. A wheat (Triticum aestivum L.) cultivar with high protein content and 2 cultivars with low protein content were subjected to a reciprocal cross. Sixteen agronomic and 4 quality characteristics were investigated. A total of 216 seeds from each F2 generation were chosen randomly and analyzed for HMW-GS composition using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Agronomic and quality characteristics were not significantly different between reciprocal crosses, indicating no cytoplasmic effect on the characteristics studied. The separation ratio of 2 HMW-GS loci was 9:3:3:1, indicating no linkage between any 2 loci. The novel HMW-GS N was detected in cultivar R145, which did not follow the Mendelian segregation ratio. A Glu-A1a(1) band was not detected in 1 individual from Tian8901xR145. Average grain weight per spike was significantly correlated with quality characteristics and may be a suitable criterion for selecting high protein content in wheat breeding programs.

Optimization of a biolistic transformation system for transfer of antifreeze gene KN2 and the bar herbicide resistance gene in common wheat

We studied the effects of different media for callus induction and differentiation, and pre-culture period of immature wheat embryo culture on biolistic transformation efficiency for including antifreeze gene KN2 and bar conferring resistance to the herbicide bialaphos. The percentage of plantlets generated from induction and differentiation media without Cu2+ was lower than those cultured on differentiation media with Cu2+ (71.15%) or induction media with Cu2+ (68.45%) and both induction and differentiation media with Cu2+ (52.17%). The combinations of Nor medium for callus induction and Cu2+ medium for regeneration, and Cu2+ medium for induction and R medium for regeneration were superior for biolistic transformation. The calli induced on Cu2+ medium and pre-cultured for 4 d before biolistic transformation, and cultured on R medium after biolistic transformation produced the highest percentage (65%) of transgenic plantlets with the KN2 gene. Overall, about 50% plantlets regenerated from calli pre-cultured 4d before bombardment carried the KN2 gene; 44.7% of the plantlets carried the bar gene, which was higher than for any other treatment, followed by pre-culture 1d with 31.43% transformation rate for the KN2 gene and 20% transformation rate for the bar gene.

Molecular detection of QTL controlling plant height components in a doubled haploid barley population

Yield losses caused by lodging in barley can be partially controlled by reducing plant height. In order to understand dwarfing mechanisms and efficiently use new dwarf germplasms for a breeding program, it is important to identify QTL of plant height components. QTL analysis was performed for seven plant height component traits using a DH population of 122 lines derived from the cross of Huaai 11 x Huadamai 6. Composite interval mapping procedures detected 20 QTL, which were mapped onto chromosomes 2H, 3H, 5H, 6H, and 7H. Eleven QTL were detected in 3 years and four QTL were detected in 2 years. QTL controlling all seven plant height component traits were found near the dwarfing gene btwd1 on chromosome 7H. These QTL accounted for 27.19 to 59.73% of phenotypic variation in seven plant height component traits. Positive transgressive segregation was found for all traits. Some of the QTL identified in this study will be useful for understanding the dwarfing mechanism and for developing new dwarf varieties using marker-assisted selection.

Characterization and molecular mapping of a dwarf mutant in wheat

A spontaneous dwarf mutant of wheat was found in an F5 generation line derived from a cross between Huamai No. 9 and Een No. 1 in 1998; it was named Huaai 01. We characterized the genetic pattern of Huaai 01 and mapped the gene controlling the dwarf trait. This dwarf mutant was found insensitive to exogenous gibberellic acid treatment, based on the length of the first leaf and the coleoptile at the seedling stage, suggesting that it plays a crucial role in the gibberellin response pathway. Genetic analysis revealed that a single gene that is partially recessive controls the dwarf phenotype in Huaai 01. We named the dwarfing gene Rht-B2. Simple sequence repeats (SSR) were examined as identifying markers linked to the Rht-B2 gene in an F2 population. We screened 904 pairs of primers and identified 5 SSR markers linked to the Rht-B2 gene. Two markers, barc1096 and xgwm495, were located on the flanking region of the Rht-B2 gene at genetic distances of 2.9 and 3.3 cM, respectively. Based on published SSR linkage data for wheat, the Rht-B2 gene was mapped to the long arm of chromosome 4B. This identification and characterization of the Rht-B2 dwarfing gene will facilitate its utilization in wheat breeding.

Analysis of tetraploid Elymus species using wheat microsatellite markers and RAPD markers

An analysis of Amplification fragment polymorphism of DNA from 27 accessions of 19 tetraploid Elymus species was carried out using 18 wheat microsatellite (WMS) primer pairs and 10 decamer primers. Ten WMS primer pairs produced multiple polymorphism on all accessions tested. Two independent phenograms, one based on WMS-PCR and one on RAPDs, separated the 19 tetraploid species into two main groups, viz., the SH genome species group and the SY genome species group. The results coincide with the genomic classification of these species and hence support previous studies showing that Elymus is not a monophyletic genus. The assays indicated that accessions within a species cluster together, which concurs with the morphological classification. Interspecific and intraspecific polymorphisms were detected by the WMS-PCR and RAPD analyses. Variation was observed among accessions of Elymus caninus. The WMS-PCR detected a much higher level of polymorphism than the RAPD analysis. WMSs seem to be more efficient markers than RAPD markers for studying the population diversity of Elymus species. The potential of cross-species amplification of microsatellite markers as an additional source for genetic analysis and applications in Elymus is discussed in the context of these results.

PEGylation for drug delivery to ischemic myocardium: pharmacokinetics and cardiac distribution of poly(ethylene glycol)s in mice with normal and ischemic myocardium

PEGylation now plays an important role in drug delivery and is considered as the method of choice for improving the pharmacokinetics and stability of parenteral agents. However, its application in treating cardiac diseases is still limited. To guide the design of PEGylation for drug delivery to ischemic myocardium, the effects of the molecular weight of PEG and the myocardial ischemic conditions on PEG levels in plasma and myocardium were studied in this work following intravenous administration of fluorescein isothiocyanate-labeled 20- and 40-kDa mPEGs to mice with normal and ischemic myocardium. The results show that myocardial ischemia caused some consistent changes in pharmacokinetic parameters of mPEGs. Due to the enhanced permeability and retention (EPR) effect caused by ischemia, the distribution of 20- and 40-kDa mPEGs in ischemic hearts was approximately 1.47- and 1.92-fold higher than that in normal hearts, respectively. Under the same heart condition (either normal or ischemic), the cardiac AUC(0.5-24h)s of the two mPEGs were comparable, although their plasma AUCs differed by nearly 4-fold; however, a smoother cardiac level-time profile was achieved by 40-kDa mPEG. This study addressed the relative importance of the EPR effect of ischemic zones and the molecular size of PEG in cardiac drug delivery, which is believed to be helpful for macromolecular drug design.

Direct observation of local potassium variation and its correlation to electronic inhomogeneity in (Ba(1-x)K(x))Fe2As2 pnictide

Local fluctuations in the distribution of dopant atoms are thought to cause the nanoscale electronic disorder or phase separation in pnictide superconductors. Atom probe tomography has enabled the first direct observations of dopant species clustering in a K-doped 122-phase pnictide. First-principles calculations suggest the coexistence of static magnetism and superconductivity on a lattice parameter length scale over a wide range of dopant concentrations. Our results provide evidence for a mixed scenario of phase coexistence and phase separation, depending on local dopant atom distributions.

A technique for combined dynamic compression-shear test

It is critically important to study the dynamic response of materials under a combined compression-shear loading for developing constitutive laws more accurately and fully. We present a novel technique to achieve the combined compression and shear loadings at high strain rates. The main apparatus consists of a strike bar, an incident bar, and two transmission bars. The close-to-specimen end of the incident bar is wedge-shaped with 90°. In each experiment, there are two identical specimens, respectively, agglutinated between one side of the wedge and one of transmission bars. When a loading impulse travels to specimens along the incident bar, because of the special geometrical shape, the specimen-incident bar interface gets an axial and a transverse velocity. Specimens endure a combined compression-shear loading at high strain rates. The compression stress and strain of the specimens are deduced from signals recorded by strain gages mounted on the bars. The shear stress is measured by two piezoelectric transducers of quartz (Y-cut with rotation angle 17.7°) embedded at the close-to-specimen end of transmission bars; the shear strain is measured with a novel optical technique, which is based on the luminous flux method. An analytic model was proposed and validated by the numerical simulations. The simulation results yield good agreement with the analytic results. The proposed technique was then validated through experiments carried out on lead specimens, by comparing experimental results with that of the split Hopkinson pressure bar experiments.

Identification of cytoplasm types in rapeseed (Brassica napus L.) accessions by a multiplex PCR assay

Cytoplasmic male sterility (CMS) has widely been used as an efficient pollination control system in rapeseed hybrid production. Identification of cytoplasm type of rapeseed accessions is becoming the most important basic work for hybrid-rapeseed breeding. In this study, we report a simple multiplex PCR method to distinguish the existing common cytoplasm resources, Pol, Nap, Cam, Ogu and Ogu-NWSUAF cytoplasm, in rapeseed. Cytoplasm type of 35 F(1) hybrids and 140 rapeseed open pollinated varieties or breeding lines in our rapeseed breeding programme were tested by this method. The results indicated that 10 of 35 F(1) hybrids are the Nap, and 25 the Pol cytoplasm type, which is consistent with the information provided by the breeders. Out of 140 accessions tested, 100 (71.4%), 21 (15%) and 19 (13.6%) accessions possess Nap, Cam and Pol cytoplasm, respectively. All 19 accessions with Pol cytoplasm are from China. Pedigree analysis indicated that these accessions with Pol cytoplasm were either restorers for Pol CMS, including Shaan 2C, Huiyehui, 220, etc. or derived from hybrids with Pol CMS as female parent. Our molecular results are consistent with those of the classical testcross, suggesting the reliability of this method. The multiplex PCR assay method can be applied to CMS "three-line" breeding, selection and validation of hybrid rapeseed.

Self-energy effects and electron-phonon coupling in Fe-As superconductors

Doping and temperature dependent studies of optical phonon modes in Fe-122 pnictides are performed using Raman scattering experiments and compared with model calculations to elucidate the role of electron-phonon and spin-phonon interaction in this family of compounds. The frequency and linewidth of the B(1g) mode at around 210 cm(-1) is highlighted as appreciable anomalies at the superconducting and spin density wave transitions are observed that strongly depend on composition. We give estimates of the electron-phonon coupling related to this renormalization and calculate the phonon self-energy on the basis of a four-band model comparing different symmetries of the order parameters. In addition, we observe a pronounced quasi-elastic Raman response for the undoped compound, suggesting persisting magnetic fluctuations in the spin density wave state.

Two-gap superconductivity in Ba1-xKxFe2As2: a complementary study of the magnetic penetration depth by muon-spin rotation and angle-resolved photoemission

We investigate the magnetic penetration depth lambda in superconducting Ba1-xKxFe2As2 (Tc approximately 32 K) with muon-spin rotation (microSR) and angle-resolved photoemission (ARPES). Using microSR, we find the penetration-depth anisotropy gamma lambda=lambda c/lambda ab and the second-critical-field anisotropy gammaHc2 to show an opposite T evolution below Tc. This dichotomy resembles the situation in the two-gap superconductor MgB2. A two-gap scenario is also suggested by an inflection point in the in-plane penetration depth lambda ab around 7 K. The complementarity of microSR and ARPES allows us to pinpoint the values of the two gaps and to arrive to a remarkable agreement between the two techniques concerning the full T evolution of lambdaab. This provides further support for the described scenario and establishes ARPES as a tool to assess macroscopic properties of the superconducting condensate.

Temperature and doping-dependent renormalization effects of the low energy electronic structure of Ba1-xKxFe2As2 single crystals

We investigate the low energy electronic structure of Ba1-xKxFe2As2 (x=0; 0.3, T_{c}=32 K) single crystals by angle-resolved photoemission spectroscopy with a focus on the renormalization of the dispersion. A kink feature is detected at E approximately 25 meV for the doped compound which vanishes at T=200 K but stays virtually constant when T_{c} is crossed. Our experimental findings rule out the magnetic resonance mode as the origin of the kink and render conventional electron-phonon coupling unlikely. They put stringent restrictions on the dominant source of the electronic interaction channel.

Electronic phase separation in the slightly underdoped iron pnictide superconductor Ba1-xKxFe2As2

Here we present a combined study of the slightly underdoped novel pnictide superconductor Ba1-xKxFe2As2 by means of x-ray powder diffraction, neutron scattering, muon-spin rotation (microSR), and magnetic force microscopy (MFM). Static antiferromagnetic order sets in below T{m} approximately 70 K as inferred from the neutron scattering and zero-field-microSR data. Transverse-field microSR below Tc shows a coexistence of magnetically ordered and nonmagnetic states, which is also confirmed by MFM imaging. We explain such coexistence by electronic phase separation into antiferromagnetic and superconducting- or normal-state regions on a lateral scale of several tens of nanometers. Our findings indicate that such mesoscopic phase separation can be considered an intrinsic property of some iron pnictide superconductors.

(pi, pi) electronic order in iron arsenide superconductors

The distribution of valence electrons in metals usually follows the symmetry of the underlying ionic lattice. Modulations of this distribution often occur when those electrons are not stable with respect to a new electronic order, such as spin or charge density waves. Electron density waves have been observed in many families of superconductors, and are often considered to be essential for superconductivity to exist. Recent measurements seem to show that the properties of the iron pnictides are in good agreement with band structure calculations that do not include additional ordering, implying no relation between density waves and superconductivity in these materials. Here we report that the electronic structure of Ba(1-x)K(x)Fe(2)As(2) is in sharp disagreement with those band structure calculations, and instead reveals a reconstruction characterized by a (pi, pi) wavevector. This electronic order coexists with superconductivity and persists up to room temperature (300 K).

Functional properties of a new low-molecular-weight glutenin subunit gene from a bread wheat cultivar

Some allelic forms of low-molecular-weight glutenin subunit (LMW-GS) can greatly influence the end-use of wheat flours, understanding the function of each allele of LMW-GS is important to wheat quality breeding. A LMW-GS gene XYGluD3-LMWGS 1(AY263369) has been cloned from bread wheat cultivar Xiaoyan 6. The deduced protein contained nine cystine residues, one more than that in all other LMW-GSs reported previously, indicating that it is either a new gene or a new allele of a known LMW-GS gene. In this study, the gene was expressed in E. coil in large scale for the testing of its functional property. Reactive Red 120-Agarose resin was used efficiently to purify the expressed LMW-GS proteins from bacteria, with the lactic acid-sodium lactate buffer (pH 4.5) which contained low concentration SDS as elution solution. The purified protein (belonging to the LMW-m family, MW about 35 KDa) was supplemented into a base flour, the results of 10 g dough mixing test indicated that incorporation of the LMW-GS increased the strength of the dough, with significant increases in mixing time (MT) and peak width (PW), and decrease in breakdown in resistance (RBD) compared with the control. In addition, the dough with incorporation of the LMW-GS had more glutenin macropolyeric protein than the control, suggesting that the LMW-GS participated in forming larger glutenin polymers, and greatly contributed to dough strength. The changes in mixing parameters and the amount of glutenin macropolyeric protein were related to the quantity of incorporating subunits.

Analysis of MS2Bnap genomic DNA homologous to MS2 gene from Arabidopsis thaliana in two dominant digenic male sterile accessions of oilseed rape (Brassica napus L.)

PCR technique was employed to isolate gene homologous to the MS2Bnap (X99922.1) from two rapeseed (Brassica napus L.) dominant digenic male sterile lines, namely 220A (male sterile) and 220B (male fertile), 6A (male sterile) and 6C (male fertile). The isolated 2,581 bp sequences from 220A (named 220A-gDNA, GenBank accession number AY288778), 220B (220B-gDNA, AY257490), 6A (6A-gDNA, DQ060318) and 6C (6C-gDNA, DQ060319) all contained six introns. Forty-one single nucleotide polymorphism (SNP) sites were detected by alignment of these four sequences, seven of them dispersed in the exon regions. Two SNPs (1247, 1656) were detected between 220A-gDNA and 220B-gDNA, and the one at nucleotide 1247 of 220A-gDNA with A replaced by C was a missense mutation, which may be the putative male sterility site in 220A. All eight SNPs identified between 6A-gDNA and 6C-gDNA were located in the third intron, so the proteins encoded by them are the same. The one SNP between 6A-/6C-gDNA and 220A-/220B-gDNA at nucleotide 2474 of 220A-/220B-gDNA with C replaced by G was a missense mutation. Mutation site of BNMS2PROT (CAA68190.1) encoded by MS2Bnap in 220A(254) and 6A/6C(584) is different, which indicated dominant digenic male sterile line 220AB and 6CA have some difference in the molecular level. Comparison of structure of MS2Bnap in B. napus with that of MS2 in Arabidopsis thaliana revealed that the similarity of exons between these two genes is higher than that of introns.

Genetic distances revealed by morphological characters, isozymes, proteins and RAPD markers and their relationships with hybrid performance in oilseed rape (Brassica napus L.)

Genetic distances (GDs) based on morphological characters, isozymes and storage proteins, and random amplified polymorphic DNAs (RAPD) were used to predict the performance and heterosis of crosses in oilseed rape (Brassica napus L.). Six male-sterile lines carrying the widely used Shaan2A cytoplasm were crossed with five restorer lines to produce 30 F1 hybrids. These 30 hybrids and their parents were evaluated for seven agronomically important traits and their mid-parent heterosis (MPH) at Yangling, Shaanxi province in Northwest China for 2 years. Genetic similarity among the parents based on 34 isozyme and seven protein markers was higher than that based on 136 RAPDs and/or 48 morphological markers. No significant correlation was detected among these three sets of data. Associations between the different estimates of GDs and F1 performance for some agronomic traits were significant, but not for seed yield. In order to enhance the predicting efficiency, we selected 114 significant markers and 43 favoring markers following statistical comparison of the mean values of the yield components between the heterozygous group (where the marker is present only in one parent of each hybrid) and the homozygous group (where the marker is either present or absent in both parents of each hybrid) of the 30 hybrids. Parental GD based on total polymorphic markers (GDtotal, indicating general heterozygosity), significant markers (GDsign, indicating specific heterozygosity) and favoring markers (GDfavor, indicating favoring-marker heterozygosity) were calculated. The correlation between GDfavor or GDsign and hybrid performance was higher than the correlation between GDtotal and hybrid performance. GDsign and GDfavor significantly correlated with plant height, seeds per silique and seed yield, but not with the MPH of the other six agronomic traits with the exception of plant height. The information obtained in this study on the genetic diversity of the parental lines does not appear to be reliable for predicting F1 yield and heterosis.

Long-term survival and prognostic study in acute promyelocytic leukemia treated with all-trans-retinoic acid, chemotherapy, and As2O3: an experience of 120 patients at a single institution

OBJECTIVE

All-trans-retinoic acid (ATRA), chemotherapy, and arsenic trioxide (As2O3) have been found to be effective in the treatment of acute promyelocytic leukemia (APL). Here we present a single institutional retrospective study with long-term follow-up to better define the prognostic factors and a rationale for the use of ATRA, chemotherapy, and As2O3 in the treatment of newly diagnosed and relapsed APL patients.

PATIENTS AND METHODS

Newly diagnosed patients with APL entering complete remission were followed up for 3 to 95 months (n = 120). Univariate and multivariate analyses were performed to identify potential prognostic factors, including age and sex; initial white blood cell (WBC) count and peak WBC level of hyperleukocytosis during induction therapy; dose of ATRA in induction; days from induction therapy to remission; postremission therapy; type of PML-RAR alpha isoform; and follow-up of reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

The median relapse-free survival (RFS) was 26 months, and median overall survival (OS) was still not reached. The estimated 5-year RFS and OS were 34.0% +/- 6.0% and 52.5% +/- 7.9%, respectively. Initial WBC count (> or = 20 x 10(9)/l), peak level of WBC during induction, and type of postremission therapy were significantly related to survival. Our multivariate study showed that only peak level of WBC count during induction therapy and type of postremission therapy were associated with RFS and that initial WBC count was associated with OS. In relapsed patients, As2O3 was very effective and remained as the most important factor for their entering remission and survival after relapse.

CONCLUSION

Through this retrospective study with long-term follow-up, some conclusions can be drawn: 1) Low-dose ATRA is as effective as the standard dose in terms of survival; 2) Initial and peak levels of WBC count during induction therapy are associated with survival; 3) A combination of chemotherapy and ATRA is better than chemotherapy or ATRA alone as postremission therapy; 4) Patients with the long form of PML-RAR alpha tend to have a more favorable OS but not RFS when compared with patients with the short form; 5) Persistent negative RT-PCR in remission is associated with favorable RFS and OS; 6) As2O3 is an effective agent for relapsed patients.

Isolation of microsatellite and RAPD markers flanking the Yr15 gene of wheat using NILs and bulked segregant analysis

Microsatellite and random amplified polymorphic DNA (RAPD) primers were used to identify molecular markers linked to the Yr15 gene which confer resistance to stripe rust (Puccina striiformis Westend) in wheat. By using near isogenic lines (NILs) for the Yr15 gene and a F2 mapping population derived from crosses of these lines and phenotyped for resistance, we identified one microsatellite marker (GWM33) and one RAPD marker (OPA19(800)) linked to Yr15. Then, bulked segregant analysis was used in addition to the NILs to identify RAPD markers linked to the target gene. Using this approach, two RAPD markers linked to Yr15 were identified, one in coupling (UBC199(700)) and one in repulsion phase (UBC212(1200)). After MAPMAKER linkage analysis on the F2 population, the two closest markers were shown to be linked to Yr15 within a distance of about 12 cM. The recombination rates were recalculated using the maximum likelihood technique to take into account putative escaped individuals from the stripe rust resistance test and obtain unbiased distance estimates. As a result of this study, the stripe rust resistance gene Yr15 is surrounded by two flanking PCR markers, UBC199(700) and GWM33, at about 5 cM from each side.

Tissue factors on acute promyelocytic leukemia and endothelial cells are differently regulated by retinoic acid, arsenic trioxide and chemotherapeutic agents

The aberrant expression of tissue factor (TF) in acute promyelocytic leukemia (APL) cells has been implicated in the pathogenesis of the APL coagulopathy. In this study, we found that in APL patients receiving ATRA or As2O3 treatment, the improvement in hypercoagulobility and hyperfibrinolysis paralleled the correction of plasma fibrinogen level and amelioration of bleeding symptoms. Notably, clinical improvement was also correlated to ATRA/As2O3-induced rapid decrease of membrane procoagulant activity (PCA) and TF contents of APL blasts. Consistent with the in vivo findings, the membrane PCA, TF antigen and its mRNA level within NB4 cells were rapidly down-regulated by 1 microM ATRA or As2O3, while 0.2 microg/ml DNR increased these TF parameters prior to its effect upon apoptosis induction. The down-regulation of TF mRNA by ATRA was partially de novo protein synthesis-dependent and at least partially attributed to a mechanism of destabilizing TF mRNA. On the other hand, in addition to its modulation on mRNA, As2O3 could also induce an accelerated TF protein turnover. These distinct effects were corroborated with the properties of these agents in causing the degradation of PML-RARalpha protein. All three therapeutic agents, however, enhanced the potential of NB4 cells to stimulate the expression of TF and PCA in endothelium. Taken together, our data suggest that the rapid and distinct regulation of TF on APL cells by these therapeutic agents might at least partially contribute to their effects on APL coagulopathy.

Genetic diversity in Elymus caninus as revealed by isozyme, RAPD, and microsatellite markers

Genetic diversity of 33 Elymus caninus accessions was investigated using isozyme, RAPD, and microsatellite markers. The three assays differed in the amount of polymorphism detected. Microsatellites detected the highest polymorphism. Six microsatellite primer pairs generated a total of 74 polymorphic bands (alleles), with an average of 15.7 bands per primer pair. Three genetic similarity matrices were estimated based on band presence or absence. Genetic diversity trees (dendrograms) were derived from each marker technique, and compared using Mantel's test. The correlation coefficients were 0.204, 0.267, and 0.164 between isozyme and RAPD distance matrices, RAPD and microsatellite distance matrices, and between isozyme and microsatellite distance matrices, respectively. The three methodologies gave differing views of the amount of variation present but all showed a high level of genetic variation in E. caninus. The following points may be drawn from this study whether based on RAPD, microsatellite, or isozyme data: (i) The Icelandic populations are consistently revealed by the three dendrograms. The congruence of the discrimination of this accession group by RAPD, microsatellite, and isozyme markers suggests that geographic isolation strongly influenced the evolution of the populations; (ii) The degree of genetic variation within accessions was notably great; and (iii) The DNA-based markers will be the more useful ones in detecting genetic diversity in closely related accessions. In addition, a dendrogram, which took into account all fragments produced by isozymes, RAPDs, and microsatellites, reflected better the relationships than did dendrograms based on only one type of marker.

Characterization of microsatellite loci from Elymus alaskanus and length polymorphism in several Elymus species (Triticeae: Poaceae)

A size-selected genomic library from Elymus alaskanus was screened for the presence of (GA)n, (GT)n, (CAC)n, and (TCT)n microsatellite sequences. A total of 28 positive clones were found for the two dinucleotide repeats, whereas no positive clones were found for the trinucleotide repeats. Positive clones were sequenced to validate the presence of microsatellites and to generate polymerase chain reaction (PCR) primers, based on the sequences flanking the microsatellite. Primer pairs were designed and evaluated for 18 selected microsatellites. The resulting loci were analysed by PCR for their usefulness as molecular markers in an array of 18 accessions representing E. alaskanus and 10 other Elymus species. PCR amplification revealed alleles for the 18 loci, which varied in having 1-10 alleles in these accessions. In the 18 accessions tested, 7 of the 18 loci were polymorphic, with gene diversity values ranging from 0.54 to 0.80 among all species. Within E. alaskanus, gene diversity values ranged from 0.20 to 0.72, with a mean of 0.48. Polymorphism was also detected within accessions. No clear relationship between total repeat length and the degree of polymorphism was observed in this study. Primer pairs designed to amplify microsatellites in E. alaskanus can be used to generate polymorphism products in other species within the genus. Hence, microsatellites are useful markers for studying both inter- and intra-specific genetic variability within Elymus.

Use of arsenic trioxide (As2O3) in the treatment of acute promyelocytic leukemia (APL): II. Clinical efficacy and pharmacokinetics in relapsed patients

The therapeutic effect of arsenic trioxide (As2O3) in the treatment of acute promyelocytic leukemia (APL) was evaluated among 15 APL patients at relapse after all-trans retinoic acid (ATRA) induced and chemotherapy maintained complete remission (CR). As2O3 was administered intravenously at the dose of 10 mg/d. Clinical CR was achieved in nine of 10 (90%) patients treated with As2O3 alone and in the remaining five patients treated by the combination of As2O3 and low-dose chemotherapeutic drugs or ATRA. During the treatment with As2O3, there was no bone marrow depression and only limited side effects were encountered. Pharmacokinetic studies, which were performed in eight patients, showed that after a peak level of 5.54 micromol/L to 7.30 micromol/L, plasma arsenic was rapidly eliminated, and the continuous administration of As2O3 did not alter its pharmacokinetic behaviors. In addition, increased amounts of arsenic appeared in the urine, with a daily excretion accounting for approximately 1% to 8% of the total daily dose administered. Arsenic contents in hair and nail were increased, and the peak content of arsenic could reach 2.5 to 2.7 microg/g tissue at CR. On the other hand, a decline of the arsenic content in hair and nail was observed after withdrawal of the drug. We conclude that As2O3 treatment is an effective and relatively safe drug in APL patients refractory to ATRA and conventional chemotherapy.

In vitro studies on cellular and molecular mechanisms of arsenic trioxide (As2O3) in the treatment of acute promyelocytic leukemia: As2O3 induces NB4 cell apoptosis with downregulation of Bcl-2 expression and modulation of PML-RAR alpha/PML proteins

It has been shown recently in China that arsenic trioxide (As2O3) is a very effective treatment for acute promyelocytic leukemia (APL). APL patients resistant to all-trans retinoic acid (ATRA) and conventional chemotherapy can still respond to AS2O3. In this study, we addressed the possible cellular and molecular mechanisms of this treatment by using NB4 cells as a model. The results show that: (1) As2O3 triggers relatively specific NB4 cell apoptosis at micromolar concentration, as proved by morphology, histogramic related nuclear DNA contents, and DNA gel eletrophoresis. (2) As2O3 does not influence bax, bcl-x, c-myc, and p53 gene expression, but downregulates bcl-2 gene expression at both mRNA and protein levels. (3) As2O3 induces a significant modulation of the PML staining pattern in NB4 cells and HL-60 cells. The micropunctates characteristic of PML-RAR alpha in NB4 cells dissappear after treatment with As2O3, whereas a diffuse PML staining occurs in the perinuclear cytoplasmic region. In addition, a low percentage of untreated NB4 cells exhibits an accumulation of PML positive particles in a compartment of cytoplasm. The percentage of these cells can be significantly increased after As2O3 treatment. A similar PML staining pattern is observed in apoptotic cells. (4) ATRA pretreatment does not influence As2O3-induced apoptosis. These results suggest that induction of cell apoptosis can be one of the mechanisms of the therapeutic effect of As2O3. Moreover, this apoptosis induction occurs independently of the retinoid pathway and may be mediated, at least partly, through the modulation of bcl-2, as well as PML-RAR alpha and/ or PML proteins.

Treatment of acute promyelocytic leukemia with all-trans retinoic acid. A five-year experience

From January 1986 to April 1991, 107 consecutive patients with acute promyelocytic leukemia (APL) were treated with retinoic acid (RA) at an oral dose of 45-60mg/m2/d, alone or in combination with chemotherapy. In 91 cases treated with RA alone, 74 (81.3%) achieved complete remission (CR). The CR rate was 75% in 16 cases treated with combined therapy. Among 50 patients closely followed for a median of 36 months (4-60), 10 received RA as continuation therapy (Group A), 10 received chemotherapy (Group B) and 30 were treated with RA and chemotherapy alternately in regular sequence (Group C). The mean survival time was 8.4, 9.7 and 21.6 months, respectively, for the 29 cases who died. The survival probability was higher in Group C than in Group A and B (P < 0.01). RA did not provoke or aggravate DIC, it did not cause marrow hypoplasia or aplasia. The side effects were relatively mild as compared with chemotherapy. CFU-GM markedly reduced before treatment was restored to normal level after CR, while the result for L-CFU was reversed. In 40 cases examined for in vitro induction of differentiation, 39 responders were culminating in CR. Aberrant karyotype t (15; 17) was positive in all 47 cases examined prior to the treatment. It disappeared in all of the 20 cases studied after achieving CR, and reappeared in 3 cases following relapse. The best regimen to maintain a longer CR duration and survival time in this study was to use RA and chemotherapy alternately as continuation therapy.

Acute promyelocytic leukemia: clinical relevance of two major PML-RAR alpha isoforms and detection of minimal residual disease by retrotranscriptase/polymerase chain reaction to predict relapse

Recent data have shown that the PML-RAR alpha fusion gene resulting from translocation t(15;17) is a highly reliable molecular marker of acute promyelocytic leukemia (APL). In this study performed on 97 Chinese patients with APL, the retrotranscriptase/polymerase chain reaction (RT/PCR) was used to evaluate the clinical relevance of the long (L) or short (S) PML-RAR alpha fusion mRNA isoforms and to study minimal residual disease during clinical remission (CR). There were more early deaths during the all-trans retinoic acid (ATRA) induction treatment and more relapses within 2 years of CR in the S-type (6 of 19 cases) than in the L-type group (2 of 33 cases) (P < .025). Among 12 cases analyzed before and after the ATRA-induced CR, 9 cases (75%) showed positive RT/PCR, whereas only 3 cases showed a negative result, justifying the need for chemotherapy after ATRA-induced CR. Eleven of 62 APL patients in CR, after ATRA-induced CR and chemotherapy consolidation (follow-up, from 3 to 72 months), showed positive RT/PCR. Five of them relapsed within 1 to 6 months after the positive test; one converted to negative after further chemotherapy; and 5 remained in CR status without further PCR data. However, the latter 5 cases all received further intensive consolidation therapy after the PCR positivity. These results show that a positive RT/PCR of PML-RAR alpha is a sensitive predictor of relapse in APL.

Breakpoint clusters of the PML gene in acute promyelocytic leukemia: primary structure of the reciprocal products of the PML-RARA gene in a patient with t(15;17)

DNA studies of the translocation t(15;17) in acute promyelocytic leukemia (APL) have shown that the retinoic acid receptor alpha (RARA) gene on chromosome 17 is juxtaposed to the promyelocytic leukemia (PML) gene on chromosome 15. The PML breakpoints have been mapped to 3 clusters: bcr1, bcr2, and bcr3. We have examined the PML breakpoint distribution in a series of 33 Chinese patients with APL. Twenty-two patients fell within bcr1, 2 within bcr2, and 9 within bcr3. The primary structure of the reciprocal chromosome translocation joints of one patient and that of their normal counterparts have been determined and compared to those of 2 previously reported cases. These studies revealed possible topoisomerase II cleavage sites close to the breakpoints and suggested implications of DNA attachment sites to nuclear matrix. We propose that these features are relevant to the process of illegitimate recombination generating the translocation.

[Treatment of acute promyelocytic leukemia (APL) with all-trans retinoic acid (ATRA): a report of five-year experience]

From January 1986 to April 1991, 100 consecutive patients with APL received oral ATRA at a dose of 60-100 mg/d alone or in combination with chemotherapy. In 84 cases treated with ATRA, 74 (88.1%) achieved CR; in the 16 cases treated with combined therapy, the CR Rate was 75%. Among the 50 patients followed up for a median of 36 months, 10 used ATRA (Group B) as continuation therapy, 10 chemotherapy (Group C), and 30 cases ATRA and chemotherapy alternatively (Group A). The mean survival was 8, 9, 21 months, respectively. For the 29 cases who died, the overall 3-year survival rate was higher in the group A (46.7%) than in the group B and C. ATRA did not provoke or aggravate DIC, nor did it cause bone marrow hypoplasia. The main side effects were dryness of the lip or skin, headache, nausea or vomiting and liver dysfunction. Severe scrotum exfoliative dermatitis with ulceration was seen in one case. In vitro induction of differentiation, GM-CFU, L-CFU assay and cytogenetic studies were performed. The results were discussed together with clinical observation regarding the mechanism of action of ATRA on APL. ATRA used as an inducer of differentiation is an alternative effective drug in the induction of remission in de novo APL as well as in cases in relapse.

Molecular rearrangements of the MYL gene in acute promyelocytic leukemia (APL, M3) define a breakpoint cluster region as well as some molecular variants

Genomic DNA probes generated from the retinoic acid receptor alpha (RARA) gene located on chromosome 17 and from the MYL gene located on chromosome 15 were used to study the chromosome 15 breakpoints resulting from the t(15; 17) translocation in 26 patients with acute promyelocytic leukemia (APL). In 20 out of 22 patients with a detectable MYL rearrangement, the breakpoints were clustered within a 4.4 kb segment designated MYLbcr. The two remaining patients exhibited a more 5' rearrangement at about 10 kb upstream of the MYLbcr region, implying the lack of at least one MYL gene exon in the resulting MYL-RARA fusion gene. The variation of chromosome breakpoints within the MYL gene may explain size heterogeneity previously observed in some MYL-RARA fusion transcripts expressed in APL cells.

The retinoic acid alpha receptor gene is frequently disrupted in its 5' part in Chinese patients with acute promyelocytic leukemia

The t(15;17)(q22;q11-q21) translocation, a hallmark for acute promyelocytic leukemia (APL), has recently been shown to disrupt the retinoic acid-alpha receptor (RARA) gene localized on band 17q21. Leukemic cell DNAs from 16 Chinese patients with APL were analysed by Southern blot hybridization with probes covering the 5' and the 3' parts of the gene. In ten patients, the breakpoints were concentrated within a 5.5 kb EcoRI fragment containing part of intron 1, whereas no rearrangement was detected in the six remaining patients. Genomic amplification of the RARA gene was observed in one case. When RNA was available (six patients), abnormal-sized RARA gene transcripts were observed. Interestingly, no rearranged transcript was found in cells from a patient during a 6-day treatment with all-trans retinoic acid, while bone marrow cells still possessed the translocation.

[Dose-effect relationships between blood lead and free erythrocyte protoporphyrin or zinc protoporphyrin]

Studies on dose-effect relationships between blood lead (PbB) and free erythrocyte protoporphyrin (FEP) or zinc protoporphyrin (ZPP) in 583 workers (male 326, female 257) was conducted. Good dose-effect relationships and S-shaped curves between PbB and logFEP, logZPP or log (ZPP/Hb) were established. Sectioned linear regression showed that linear correlation was obtained while PbB between 0.48 (10 micrograms/dl) and 3.36 mumol/L (70 micrograms/dl) (male) or 0.48 (10 micrograms/dl) and 2.88 mumol/L (60 micrograms/dl) (female). However, while PbB below 0.48 mumol/L (10 micrograms/dl), there was no linear correlation. The increasing of FEP, ZPP slowed down remarkably as PbB were beyond 3.36 mumol/L (70 micrograms/dl) (male) or 2.88 mumol/L (60 micrograms/dl) (female). Therefore, the degree of lead poisoning can't be classified by the values of FEP, ZPP among plumbism.