Intracardiac Echocardiography-Guided Implantation for Proximal Left Bundle Branch Pacing.

BACKGROUND: Multiple screw-in attempts under fluoroscopy are often needed to place the pacing lead tip near or at the left bundle branch (LBB). This study was conducted to evaluate the feasibility of implanting an LBB pacing lead in the proximal LBB (PLBB) guided by intracardiac echocardiography (ICE). METHODS: The distribution of the LBB was initially determined by ICE anatomic imaging and 3-dimensional electrical mapping of His and LBB potentials in 20 patients in the first parts of the study. In the second part, 101 consecutive pacemaker-indicated patients were randomized into the ICE-guided and non-ICE groups for LBB pacing implantation. The procedural details and electrophysiological characteristics of the 2 groups were compared. RESULTS: In the first part of the study, PLBB was identified at 10 to 20 mm from the tricuspid annulus toward the apex with an area of 4.5±1.1 cm2. In the second part, the number of lead screw-in attempts in the septum was fewer in the ICE group than in the non-ICE group (1.43±0.62 versus 1.98±0.75, P=0.0002). The duration of the procedure (26±8 versus 43±9 minutes, P<0.001) and fluoroscopy for LBB pacing implantation (7.4±1.8 versus 10.7±2.4 minutes, P<0.001) in the ICE group was significantly shorter than those in the non-ICE group. LBB pacing in the ICE group generated a lesser QRS duration with more cases of LBB trunk pacing (46.8% versus 25%, P=0.031) and PLBB (91.5% versus 72.7%, P=0.0267) pacing compared with that in the non-ICE group. CONCLUSIONS: The basal left ventricular septum can be better visualized using ICE. ICE-guided PLBB pacing is feasible and safe, with a shorter duration required for the procedure and fluoroscopy, and generates greater LBB trunk pacing and PLBB pacing.

[Clinical Analysis of Bloodstream Infection after Hematopoietic Stem Cell Transplantation].

OBJECTIVE: To analyze the clinical characteristics of bloodstream infection (BSI) in patients treated by hematopoietic stem cell transplantation (HSCT). METHODS: The clinical characteristics, distribution of pathogenic bacteria causing BSI and drug sensitivity of 910 patients treated by HSCT in our department from January 2013 to June 2020 were retrospectively analyzed. RESULTS: Among 910 HSCT patients, 111 patients were diagnosed as BSI within 100 days after transplantation, and 98 patients showed BSI during the period of agranulocytosis. Multivariate analysis showed that the usage of anti-thymocyte globulin (ATG), long duration of agranulocytosis and low infusion volume of mononuclear cell (MNC) were the independent risk factors affecting BSI after HSCT. Among 121 pathogenic bacteria isolated, 76 Gram-negative (G-) bacteria (62.8%), 40 Gram-positive (G+) bacteria (33.0%), and 5 fungi (4.1%) were detected out. The top three pathogens were Escherichia coli, Staphylococcus epidermidis and Pseudomonas aeruginosa. The drug-resistance rates of Escherichia coli and Klebsiella pneumoniae to carbapenems was 14.3% and 7.7%, respectively, and Pseudomonas aeruginosa was 66.7%. The susceptibility of G+ bacteria to vancomycin, linezolid and teicoplanin was 97.5%, 100% and 100%, respectively. The crude mortality rate of the patients with BSI at 100 days after HSCT was significantly higher than that of patients without BSI (P<0.001). CONCLUSION: The usage of ATG, long duration of agranulocytosis and low infusion volume of MNC are independent risk factors for BSI after HSCT. The pathogens after HSCT are mainly G- bacteria. Pseudomonas aeruginosa is highly resistant to carbapenems. Key words　　;

Pathogenicity of a currently circulating Chinese variant pseudorabies virus in pigs.

AIM: To test the pathogenicity of pseudorabies virus (PRV) variant HN1201 and compare its pathogenicity with a classical PRV Fa strain. METHODS: The pathogenicity of the newly-emerging PRV variant HN1201 was evaluated by different inoculating routes, virus loads, and ages of pigs. The classical PRV Fa strain was then used to compare with HN1201 to determine pathogenicity. Clinical symptoms after virus infection were recorded daily and average daily body weight was used to measure the growth performance of pigs. At necropsy, gross pathology and histopathology were used to evaluate the severity of tissue damage caused by virus infection. RESULTS: The results showed that the efficient infection method of RPV HN1201 was via intranasal inoculation at 10(7) TCID50, and that the virus has high pathogenicity to 35- to 127-d old pigs. Compared with Fa strain, pigs infected with HN1201 showed more severe clinical symptoms and pathological lesions. Immunochemistry results revealed HN1201 had more abundant antigen distribution in extensive organs. CONCLUSION: All of the above results suggest that PRV variant HN1201 was more pathogenic to pigs than the classical Fa strain.

Three-dimensional reconstruction of anomalous eutectic in laser remelted Ni-30 wt.% Sn alloy.

Laser remelting has been performed on Ni-30 wt.% Sn hypoeutectic alloy. An anomalous eutectic formed at the bottom of the molten pool when the sample was remelted thoroughly. 3D morphologies of the α-Ni and Ni3Sn phases in the anomalous eutectic region were obtained and investigated using serial sectioning reconstruction technology. It is found that the Ni3Sn phase has a continuous interconnected network structure and the α-Ni phase is distributed as separate particles in the anomalous eutectic, which is consistent with the electron backscatter diffraction pattern examinations. The α-Ni particles in the anomalous eutectic are supersaturated with Sn element as compared with the equilibrium phase diagram. Meanwhile, small wavy lamella eutectics coexist with anomalous eutectics. The Trivedi-Magnin-Kurz model was used to estimate undercooling with lamellar spacing. The results suggest that the critical undercooling found in undercooling solidification is not a sufficient condition for anomalous eutectic formation. Besides, α-Ni particles in the anomalous eutectic do not exhibit a completely random misorientation and some neighboring α-Ni particles have the same orientation. It is shown that both the coupled and decoupled growth of the eutectic two phases can generate the α-Ni + Ni3Sn anomalous eutectic structure.

Virus-induced gene silencing of PEAM4 affects floral morphology by altering the expression pattern of PsSOC1a and PsPVP in pea.

pea-MADS4 (PEAM4) regulates floral morphology in Pisum sativum L., however, its molecular mechanisms still remain unclear. Virus-induced gene silencing (VIGS) is a recently developed reverse genetic approach that facilities an easier and more rapid study of gene functions. In this study, the PEAM4 gene was effectively silenced by VIGS using a pea early browning virus (PEBV) in wild type pea JI992. The infected plants showed abnormal phenotypes, as the floral organs, especially the sepals and petals changed in both size and shape, which made the corolla less closed. The petals changed in morphology and internal symmetry with, the stamens reduced and carpel dehisced. Larger sepals and longer tendrils with small cauline leaves appeared, with some sepals turning into bracts, and secondary inflorescences with fused floral organs were formed, indicating a flower-to-inflorescence change. The infected plants also displayed a delayed and prolonged flowering time. The PEAM4-VIGS plants with altered floral morphology were similar to the pim (proliferating inflorescence meristem) mutant and also mimicked the phenotypes of ap1 mutants in Arabidopsis. The expression pattern of the homologous genes PsSOC1a and PsSVP, which were involved in flowering time and florescence morphological control downstream of PEAM4, were analyzed by real-time RT-PCR and mRNA in situ hybridization. PsSOC1a and PsSVP were ectopically expressed and enhanced in the floral meristems from PEAM4-silenced plants. Our data suggests that PEAM4 may have a similar molecular mechanism as AtAP1, which inhibits the expression of PsSOC1a and PsSVP in the floral meristem from the early stages of flower development. As such, in this way PEAM4 plays a crucial role in maintaining floral organ identity and flower development in pea.

Inhibition of extracellular signal-regulated kinase activity by sorafenib increases sensitivity to DNR in K562 cells.

The mitogen-activated protein kinase (MAPK) pathway has a protective function on the management of hematologic malignancies. The aim of this study was to assess whether the induction of MAPK-mediated effects contributes to the therapeutic value of combination sorafenib and daunorubicin (DNR) treatment. Herein, we found that DNR increased phosphorylation of extracellular signal-regulated kinases (ERK1/2) in K562 cells. ERK1/2 activity was blocked by either the mitogen-induced extracellular kinase (MEK) inhibitor U0126 or a multi-kinase inhibitor sorafenib. Of note, sorafenib sensitized K562 to DNR by inhibiting proliferation and inducing apoptosis in a dose-dependent manner which was through blocking the RAF/MEK/ERK pathway. Moreover, K562 cells transfected with a constitutively active MEK2DD plasmid showed increasing IC50 values following DNR treatment compared with control cells. Combination of DNR with MEK inhibitor U0126 synergistically inhibited K562 cell growth. In conclusion, our results indicated that sorafenib sensitized K562 cells to DNR-induced cytotoxicity by downregulating p-ERK1/2 expression. DNR in combination with sorafenib may represent a new and potential therapeutic strategy in treating acute leukemia with high p-ERK1/2 levels.

Electrochemical synthesis of a polyaniline network on a poly(o-aminophenol) modified glassy carbon electrode and its use for the simultaneous determination of ascorbic acid and uric acid.

A polyaniline (PAN) network structure was fabricated on a poly(o-aminophenol) (POAP) modified glassy carbon electrode (GCE) by using a three-step electrochemical deposition procedure, and applied to the electro-catalytic oxidation of ascorbic acid (AA) and uric acid (UA). Scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) have been employed to investigate the PAN network structure on a POAP modified GCE (PAN-OAP/GCE), which indicated the formation of a 3-dimensional (3D) non-periodic PAN network with good electrical contract and the maintenance of the electro-activity of PAN in neutral and even in alkaline media. Because of its different catalytic effect towards the electro-oxidation of AA and UA, the PAN-OAP/GCE could resolve the overlapped voltammetric response of AA and UA into two sharp and well-defined voltammetric peaks with both CV and differential pulse voltammetry (DPV), which could be applied for the selective and simultaneous determination of AA and UA in their binary mixture. Under the optimum conditions, the calibration curves for AA and UA were in the range of 2.5 - 6200 and 0.5 - 450 µmol L(-1) with correlation coefficients of 0.998 and 0.998, respectively. The detection limits (S/N = 3) are 1.4 and 0.3 µmol L(-1) for AA and UA, respectively. Besides good stability and reproducibility, the PAN-OAP/GCE also exhibited good sensitivity and selectivity. The proposed method has been applied to the simultaneous detection of AA and UA in human urine with satisfactory result.

[Sorafenib induces apoptosis of U937 cells via inhibiting WNT signal pathway].

This study was aimed to investigate the effect of multikinase inhibitor sorafenib on the proliferation and apoptosis of U937 cells and its possible mechanism. U937 cells were treated with different concentrations of sorafenib for 48 hours. Cell viability was determined by Cell Counting Kit-8; cell apoptosis and cell ratio in cell cycle were detected by flow cytometry with Annexin V/PI staining and PI staining respectively; expressions of GSK-3ß, ß-catenin and cyclin-D1 were assayed by Western blot. The results showed that the proliferation of U937 cells was inhibited by sorafenib in a dose-dependent manner (p < 0.05). Sorafenib induced cell apoptosis and cell cycle G(1)/G(0) arrest. Compared with results of Western blot before treatment, expression of inactivated GSK-3ß, ß-catenin and Cyclin-D1 down-regulated in a dose-dependent manner after treatment with sorafenib, this same changes were observed after up-regulation of inactivated GSK-3ß by LiCl (p < 0.05). It is concluded that sorafenib inhibits the proliferation of U937 cells and induces cell apoptosis through reducing negative regulation of WNT signal pathway on inactivated GSK-3ß and down-regulating ß-catenin and cyclin-D1 level, which result in U937 cell cycle G(1)/G(0) arrest.

[Effect of sorafenib combined with daunorubicin on K562 cell line].

The aim of this study was to investigate the effect of sorafenib combined with daunorubicin on leukemic k562 cell line. The inhibitory effect of sorafenib alone and its combination with daunorubicin on K562 cell proliferation was detected by MTT method; the synergistic effect was measured by CDI (coefficient of drug interaction); the apoptosis of K562 cells was observed by flow cytometry with Hoechst 33258 staining. The results showed that the sorafenib alone or its combination with daunorubicin could significantly inhibit K562 cell proliferation and the combination of both drugs displayed synergistic effect on K562 cells, meanwhile the apoptotic cells increased. It is concluded that the combination of sorafenib and daunorubicin has a obviously synergistic inhibitory effect on leukemic cell line K562.

Rapid differential detection of classical and highly pathogenic North American Porcine Reproductive and Respiratory Syndrome virus in China by a duplex real-time RT-PCR.

Since the emergence of highly pathogenic North American Porcine Reproductive and Respiratory Syndrome virus (H-US-PRRSV) in 2006, the classical North American PRRSV (C-US-PRRSV) and H-US-PRRSV isolates have coexisted in Chinese swine herds. A duplex real-time RT-PCR assay using minor groove binder (MGB) probes for differential detection of the two US PRRSV isolates was developed. The specificity, sensitivity, reproducibility, and interference test of this assay were validated. The sensitivity of the assay was 3.2TCID(50)/ml or 38 RNA copies/microl for C-US-PRRSV and 0.4 TCID(50)/ml or 14 RNA copies/microl for H-US-PRRSV. Both assays were 10 times more sensitive than the current methods. A total of 302 clinical samples were tested by duplex real-time RT-PCR and conventional RT-PCR assays, and the results showed over 98.7% agreement. In addition, the new assay can be completed in less than 2h. This duplex real-time RT-PCR assay is a promising tool for rapid differential detection and epidemiology of US PRRSV in China.

Effectiveness of a discharge education program in reducing the severity of postpartum depression: a randomized controlled evaluation study.

OBJECTIVE: The effectiveness of a hospital discharge education program including information on postnatal depression was evaluated to reduce psychological morbidity after childbirth. METHODS: A randomized controlled trial (RCT) was conducted in a regional hospital in Taipei. Two hundred first-time mothers agreed to take part and were randomly allocated to an intervention group (n=100) or control group (n=100). The intervention group received discharge education on postnatal depression provided by postpartum ward nurses. The control group received general postpartum education. The main outcome measure was the Edinburgh Postnatal Depression Scale (EPDS) administered by postal questionnaire at six weeks and three months after delivery. RESULTS: Women who received discharge education intervention on postnatal depression were less likely to have high depression scores when compared to the control group at three months postpartum. CONCLUSION: A discharge educational intervention including postnatal depression information given to women during the postpartum stay benefits psychological well-being. PRACTICE IMPLICATIONS: A postpartum discharge education program including information on postnatal depression should be integrated into postpartum discharge care in general practice.

Molecular mutations associated with the in vitro passage of virulent porcine reproductive and respiratory syndrome virus.

Mutants of a highly pathogenic, porcine reproductive, and respiratory syndrome virus (PRRSV), JXA1 strain, were prepared by continuous in vitro passage. Genomic sequence comparisons were made between mutants obtained at different passages and the parental strain JXA1. The mutant strain obtained at passage 80 contained a 12 nucleotide insertion and 108 nucleotide mutations that resulted in 45 amino acid changes. Most of these changes (89%) occurred between passage 10 and 45 and were genetically stable for the next 35-70 passages. A comparison of the mutants, their parental strain, and several American PRRSV strains, identified 13 characteristic amino acid changes. These sites, as well as the distinct 12 nucleotide insertion, represent possible genetic markers for the evaluation of live vaccine applications, particularly for additional studies of the safety and potency of live PRRSV vaccines.

Overexpression of the cucumber LEAFY homolog CFL and hormone treatments alter flower development in gloxinia (Sinningia speciosa).

Leafy (LFY) and LFY-like genes control the initiation of floral meristems and regulate MADS-box genes in higher plants. The Cucumber-FLO-LFY (CFL) gene, a LFY homolog in Cucumis sativus L. is expressed in the primordia, floral primordia, and each whirl of floral organs during the early stage of flower development. In this study, functions of CFL in flower development were investigated by overexpressing the CFL gene in gloxinia (Sinningia speciosa). Our results show that constitutive CFL overexpression significantly promote early flowering without gibberellin (GA(3)) supplement, suggesting that CFL can serve functionally as a LFY homolog in gloxinia. Moreover, GA(3) and abscisic acid (ABA) treatments could modulate the expression of MADS-box genes in opposite directions. GA(3) resembles the overexpression of CFL in the expression of MADS-box genes and the regeneration of floral buds, but ABA inhibits the expression of MADS-box genes and flower development. These results suggest that CFL and downstream MADS-box genes involved in flower development are regulated by GA(3) and ABA.

Effectiveness of an exercise support program in reducing the severity of postnatal depression in Taiwanese women.

BACKGROUND: Depression during the perinatal period should be identified as early as possible to avoid negative effects on the new family. The purpose of this study was to examine the effectiveness of an exercise support program on reducing psychological morbidity after childbirth. METHODS: A controlled trial was conducted in a regional hospital in Taipei, Taiwan. Eighty primiparas with an Edinburgh Postnatal Depression Scale (EPDS) score above 10 at 4 weeks postpartum agreed to participate. They were allocated alternately to an intervention (to receive exercise support) and control group (to receive standard care) at 6 weeks postpartum. The exercise support consisted of 1 hour per week at the hospital and two sessions at home for 3 months. Sixty-three primiparas finished the exercise support program. The main outcome measure was the EPDS score at 5 months postpartum. RESULTS: Women who received the exercise support program were less likely to have high depression scores after childbirth when compared with the control group. CONCLUSIONS: The exercise support program given to postpartum women appeared to benefit their psychological well-being. This promising finding should be tested in a well-designed randomized controlled trial.

[Studies on the megasporogenesis and microsporegenesis and the development of the female gametophyte and male gametophyte in Camptotheca acuminate].

The ovarium is hypostasy in Camptotheca acuminate Decne.. It has a locule and an ovule. The ovule is pendulous, anatropous andunitegmic. The ovule of Camptotheca acuminate Decne. is pseudocrassinucellate ovule. The development of embryo sac is polygonum type. Cytokinesis during the meiosis of microspore mother cells is of simultaneous type. The arrangement of microspores in tetrad is tetrahedral and isobilateral. One-nucleate microspore is triangle. Maturity pollen is triangle, circular and square. This paper mainly studied the megasporogenesis and microsporogenesis, and studied the development of their female and male gametophyte in Camptotheca acuminate Decne., and preliminarily discussed the cause of the part pistil abortion in Camptotheca acuminate Decne.

Sequence analysis of a novel insertion site of transposon IS10.

A sacB mutant was obtained by transposon IS10 inactivation of a plasmid pXT3sacB carrying the sacB gene. Sequencing of this mutant plasmid DNA (GenBank accession No. AY580883.1) showed that the IS10 flanking the 22 bp inverted repeats were 5'-CTGAGAGATCCCCTCATAATTT-3' and 5'-AAATCATTAGGGGATTCATCAG-3', which were the similar to those published in reports previously. However, the target sequence adjacent to IS10 was 5'-TGCTTGGTT-3' instead of the previously reported 5'-NGCTNAGCN-3'. To our knowledge, this is the first report on the novel insertion site of IS10. In addition, Southern blot hybridization confirmed that the mobile IS10 originated from the chromosomal DNA of the host strain Escherichia coli DH5alpha and that there were two copies in the DH5alpha genome.

[Morphological studies on direct regeneration of floral buds from in vitro cultures of sepal segments in Sinningia speciosa hiern].

The morphological changes in the cultures of sepal segments in Sinningia speciosa Hiern were observed with Zeiss Stemi 2000-C Stereomicroscope from 0 to 65 days after culture in vitro. The light yellow globular protuberances were observed on the cut edge and the surface of sepal segments after culture for 24 days. Then the globular protuberances grew bigger gradually. A lot of floral buds on the surface of sepal segments formed after culture for 60 days. The morphological changes in the cultures of sepal segments were studied with light microscopy after culture for 0 to 30 days as well. The cells of tissues of sepal segments arranged regularly and no dividing cell was observed on the first day culture. There appeared some small meristematic centers of dividing cells on cut edge and the lower epidermis on the 7th day after culture. To the 20th day culture in vitro, the floral organ primordia were differentiated on the cut edge. On the 30th day culture, floral buds with petal, stamen primordia were observed. In addition, the morphological changes in the cultures of sepal segment were studied during the 14 to 30 days culture with scanning microscopy as well.

Wrinkled petals and stamens 1, is required for the morphogenesis of petals and stamens in Lotus japonicus.

Although much progress has been made in understanding how floral organ identity is determined during the floral development, less is known about how floral organ is elaborated in the late floral developmental stages. Here we describe a novel floral mutant, wrinkled petals and stamens1 (wps1), which shows defects in the development of petals and stamens. Genetic analysis indicates that wps1 mutant is corresponding to a single recessive locus at the long arm of chromosome 3. The early development of floral organs in wps1 mutant is similar to that in wild type, and the malfunction of the mutant commences in late developmental stages, displaying a defect on the appearance of petals and stamens. In the mature flower, petals and stamen filaments in the mutant are wrinkled or folded, and the cellular morphology under L1 layer of petals and stamen filaments is abnormal. It is found that the expression patterns of floral organ identity genes are not affected in wps1 mutants compared with that of wild type, consistent with the unaltered development of all floral organs. Furthermore, the identities of epidermal cells in different type of petals are maintained. The histological analysis shows that in wps1 flowers all petals are irregularly folded, and there are knotted structures in the petals, while the shape and arrangement of inner cells are malformed and unorganized. Based on these results, we propose that Wps1 acts downstream to the class B floral organ identity genes, and functions to modulate the cellular differentiation during the late flower developmental stages.

[Hairy root induced by wild-type agrobacterium rhizogenes K599 in soybean, cucumber and garden balsam in vivo].

The plantlets of soybean, cucumber and garden balsam were inoculated by wild-type Agrobacterium rhizogenes K599, and hairy root was induced on inoculated sites in vivo. The frequencies of hairy root induction from wound cotyledons of soybean, cucumber and garden balsam were 100%, 65% and 91%, respectively. Moreover, hairy root was induced from healthy cucumber axillary bud with frequency of 10%. PCR analysis of hairy root DNA was conducted using the primers from rolC gene. The PCR results showed that all hairy root lines contained T-DNA. The established system should be ideal for studying soybean and cucumber nematode and garden balsam breeding of flower dwarf architecture.

[Studies on the megasporogenesis and microsporogenesis and the development of their female and male gametophyte in Magnolia biloba].

The anther of Magnolia biloba is tetrasporangiate with glandular tapetum, which consists of one or two layers of cells. Cytokinesis during meiosis of its microspore mother cell is modified simultaneous type, and the microspore tetrads are isobilateral. Mature pollen grains are two-celled. Tetrad cells and microspores are irregularly shaped during the microsporogenesis. There were two ovules on the ventral surface of unicarpellate ovary wall. Ovules were anatropous, bitegmnous and crassinucellar. Archesporial cell was one cell and differentiated from cell in the second layer beneath epidermis. The development of the embryo sac conformed to the polygonum type. The embryological characteristics of Magnolia biloba are very similar to those of other species in Magnoliaceae. The megasporogenesis and microsporogenesis and the development of their female and male gametophyte are partially abnormal. Abnormal phenomena in the process of reproduction of Magnolia biloba causing this species to be endangered was discussed.