Magnetic Properties and Microstructure of FePt(BN, X, C) (X = Ag, Re) Films.

A sputtered FePt(BN, Re, C) film, here boron nitride (BN), was compared to a reference sample FePt(BN, Ag, C). Intrinsically, these films illustrate a high anisotropy field (Hk) and perpendicular magnetocrystalline anisotropy (Ku),although the reference sample shows a higher value (Hk = 69.5 kOe, Ku = 1.74 × 107 erg/cm3) than the FePt(BN, Re, C) film (Hk = 66.9 kOe, Ku = 1.46 × 107 erg/cm3). However, the small difference in the anisotropy constant (K2/K1) ratio presents a close tendency in the angular dependence of the switching field. Extrinsically, the out-of-plane coercivity for the reference sample is 32 kOe, which is also higher than the FePt(BN, Re, C) film (Hc = 27 kOe), and both films present lower remanence (Mr(parallel)/Mr(perpendicular) = 0.08~0.12), that is, the index for perpendicular magnetic anisotropy. The higher perpendicular magnetization for both films was due to highly (001) textured FePt films, which was also evidenced by the tight rocking width of 4.1°/3.0° for (001)/(002) X-ray diffraction peaks, respectively, and high-enough ordering degree. The reference sample was measured to have a higher ordering degree (S = 0.84) than FePt(BN, Re, C) (S = 0.63). As a result, the Ag segregant shows stronger ability to promote the ordering of the FePt film; however, the FePt(BN, Re, C) film still has comparable magnetic properties without Ag doping. From the surface and elemental composition analysis, the metallic Re atoms found in the FePt lattice result in a strong spin-orbital coupling between transition metal Fe (3d electron) and heavy metals (Re, Pt) (5d electron) and we conducted high magnetocrystalline anisotropy (Ku). Above is the explanation that the lower-ordered FePt(BN, Re, C) film still has high-enough Ku and out-of-plane Hc. Regarding the microstructure, both the reference sample and FePt(BN, Re, C) show granular structure and columnar grains, and the respective average grain size and distributions are 6.60 nm (12.5%) and 11.2 nm (15.9%). The average widths of the grain boundaries and the aspect ratio of the columnar grain height are 2.05 nm, 1.00 nm, 2.35 nm, and 1.70 nm, respectively.

Guidezilla extension catheter for percutaneous interventional therapy of complex lesions via a transradial approach: Case series from a single-center experience.

BACKGROUND: Guide catheter extension systems have become one of the most powerful tools for address-ing complex lesions during percutaneous coronary intervention (PCI), but data on a new-generation rapid exchange extension catheter - the Guidezilla catheter - are limited. Summarized herein reports on experience using the Guidezilla catheter for complex coronary lesions via a transradial approach at the documented institution an evaluation of its safety and efficacy. METHODS: A total of 25 patients (19 males and 6 females) who underwent PCI via the radial approach with the Guidezilla catheter for adequate back-up support and to facilitate equipment delivery were enrolled. The clinical, angiographic and procedural data of all 26 procedures in 25 patients (1 patient underwent two PCI procedures on different lesions) were collected to evaluate the safety and efficacy of this novel equipment. RESULTS: The mean age of the enrolled patients was 67.7 ± 8.41 years old. The mean depth of intuba-tion was 27.90 ± 12.23 mm. Stent implantation was successful in 23 out of 26 procedures (88.5%) and failed in 3 cases: 1 case of tortuosity and severe angulation in a chronic total occlusion lesion; 1 case of an existing type B dissection (NHLBI classification system for coronary artery dissection types); and 1 case in which a stent was stripped off its balloon. None of the patients experienced coronary dissection, perforation, air embolism, pressure dampening or other major complications during the procedure. CONCLUSIONS: The Guidezilla extension catheter is an effective and safe tool that provides improved back-up support and increases the success rate of PCI for complex coronary lesion by radial access.

Genome-wide analysis of the GST gene family in Gossypium hirsutum L.

Glutathione-S-transferase (GST) is a ubiquitous multi-functional protein superfamily that plays important roles in plant primary and secondary metabolism, stress and intercellular signal transduction. Concomitantly, it also functions as a ligand in the metabolism of plant hormones and substance transport. In order to understand the GST gene family in upland cotton (Gossypium hirsutum L.), herein we analyzed the species, evolutionary relationship, physical location, gene structure, conserved motifs and expression patterns. We identified 70 GST genes in the whole genome of upland cotton, and divided them into U, F, T, Z, EF1Bγ and TCHQD groups by phylogenetic tree and gene structure analyses. The gene mapping analysis indicated that the GST genes were on every chromosome except chromosome AD/At2, AD/At4, AD/At5, AD/Dt5 and AD/Dt10. Moreover, the GST gene cluster appeared on four chromosomes (AD/At9, AD/Dt7, AD/Dt12 and AD/Dt13). qRT-PCR assays showed that eight genes (GhGSTF2-9) were expressed in the root, stem, leave and fiber of different developmental stages while GhGSTF1 might be a pseudogene. Combining qRT-PCR and bioinformatic analysis, we speculated that GhGSTF8 might be involved in the transport and accumulation of proanthocyanidins/anthocyanins; GhGSTF4, 6 and 9 might play roles in regulating the growth and stress response of upland cotton; the function of GhGSTF2, 3, 5 and 7 remains to be further investigated. Our work provides a theoretical basis for further studies on the molecular evolution and function of the GST gene family in upland cotton.

The Caveolin-3 P104L mutation of LGMD-1C leads to disordered glucose metabolism in muscle cells.

Caveolin-3 (CAV3) is a muscle specific protein that plays an important role in maintaining muscle health and glucose homeostasis in vivo. A novel autosomal dominant form of LGMD-1C in humans is due to a P104L mutation within the coding sequence of the human CAV3 gene. The mechanism by which the LGMD-1C mutation leads to muscle weakness remains unknown. Our objective was to determine whether muscle weakness was related to the imbalance of glucose metabolism. We found that when the P104L mutation was transiently transfected into C2C12 cells, there was decreased glucose uptake and glycogen synthesis after insulin stimulation. Immunoblotting analysis showed that the P104L mutation resulted in decreased expression of CAV3, CAV1 and pAkt. Confocal immunomicroscopy indicated that the P104L mutation reduced CAV3 and GLUT4 in the cell membrane, which accumulated mainly near the nucleus. This work is the first report of an association between muscle weakness due to LGMD-1C and energy metabolism. The P104L mutation led to a decrease in C2C12 muscle glucose uptake and glycogen synthesis and may be involved in the pathogenesis of LGMD-1C.

Elevated serum HMGB1 in pulmonary arterial hypertension secondary to congenital heart disease.

AIMS: This study investigated the potential value of serum high mobility group box-1 (HMGB1) level in the diagnosis, staging and treatment response of patients with pulmonary arterial hypertension secondary to congenital heart disease (PAH-CHD). METHODS AND RESULTS: This was a single-center prospective study in 106 CHD patients. Serum HMGB1 levels were measured by enzymelinked immunosorbent assay. HMGB1 levels were significantly increased in patients with PAH compared to patients without PAH (P<0.01) and healthy controls (P<0.001). HMGB1 levels significantly correlated with pulmonary arterial pressure (P<0.001) and pulmonary vascular resistance (PVR) (P<0.001). In patients with severe PAH, HMGB1 levels were significantly higher in patients with Eisenmenger syndrome (ES) than in patients exhibiting low PVR (P<0.001). Severe PAH and ES was identified by serum HMGB1 with a cutoff value of 13.62ng/mL (P<0.001) with a specificity of 82.8% and a sensitivity of 90%, and a cutoff value of 21.62ng/mL (P=0.001) with a specificity of 85.2% and a sensitivity of 64.3%, respectively. HMGB1 levels were significantly decreased after sildenafil therapy for 6months (P<0.01). CONCLUSIONS: Our study suggests that serum HMGB1 level may be used as a biomarker to identify PAH in CHD patients, assess pulmonary vascular remodeling, and evaluate the treatment response to sildenafil.

Physalin A induces G2/M phase cell cycle arrest in human non-small cell lung cancer cells: involvement of the p38 MAPK/ROS pathway.

Physalin A (PA) is an active withanolide isolated from Physalis alkekengi var. franchetii, a traditional Chinese herbal medicine named Jindenglong, which has long been used for the treatment of sore throat, hepatitis, and tumors in China. In the present study, we firstly investigated the effects of PA on proliferation and cell cycle distribution of the human non-small cell lung cancer (NSCLC) A549 cell line, and the potential mechanisms involved. Here, PA inhibited cell growth in dose- and time-dependent manners. Treatment of A549 cells with 28.4 µM PA for 24 h resulted in approximately 50 % cell death. PA increased the amount of intracellular ROS and the proportion of cells in G2/M. G2/M arrest was attenuated by the addition of ROS scavenger NAC. ERK and P38 were triggered by PA through phosphorylation in a time-dependent manner. The phosphorylation of ERK and P38 were not attenuated by the addition of NAC, but the use of the p38 inhibitor could reduce, at least in part, PA-induced ROS and the proportion of cells in G2/M. PA induces G2/M cell cycle arrest in A549 cells involving in the p38 MAPK/ROS pathway. This study suggests that PA might be a promising therapeutic agent against NSCLC.

Geminin is Essential to Prevent DNA Re-Replication-Dependent Apoptosis in Pluripotent Cells, but not in Differentiated Cells.

Geminin is a dual-function protein unique to multicellular animals with roles in modulating gene expression and preventing DNA re-replication. Here, we show that geminin is essential at the beginning of mammalian development to prevent DNA re-replication in pluripotent cells, exemplified by embryonic stem cells, as they undergo self-renewal and differentiation. Embryonic stem cells, embryonic fibroblasts, and immortalized fibroblasts were characterized before and after geminin was depleted either by gene ablation or siRNA. Depletion of geminin under conditions that promote either self-renewal or differentiation rapidly induced DNA re-replication, followed by DNA damage, then a DNA damage response, and finally apoptosis. Once differentiation had occurred, geminin was no longer essential for viability, although it continued to contribute to preventing DNA re-replication induced DNA damage. No relationship was detected between expression of geminin and genes associated with either pluripotency or differentiation. Thus, the primary role of geminin at the beginning of mammalian development is to prevent DNA re-replication-dependent apoptosis, a role previously believed essential only in cancer cells. These results suggest that regulation of gene expression by geminin occurs only after pluripotent cells differentiate into cells in which geminin is not essential for viability.

Asymmetric Dimethyl-L-Arginine is a Biomarker for Disease Stage and Follow-Up of Pulmonary Hypertension Associated with Congenital Heart Disease.

This study investigated the clinical value of plasma asymmetrical dimethyl-L-arginine (ADMA) level in the diagnosis, staging, and treatment response in congenital heart disease (CHD) patients with pulmonary arterial hypertension (PAH). This was a single-center prospective observational study in 80 CHD patients. Plasma ADMA levels were measured by enzyme-linked immunosorbent assay. Plasma ADMA levels were significantly increased in CHD patients with PAH compared with CHD patients without PAH (P < 0.01) and healthy controls (P < 0.001). In CHD patients with severe PAH, plasma ADMA levels were significantly higher in patients with Eisenmenger's syndrome (ES) than in patients exhibiting low pulmonary vascular resistance (P < 0.001). The plasma ADMA levels significantly correlated with pulmonary arterial pressure (P < 0.001) and pulmonary vascular resistance (P < 0.001) in patients with CHD. Severe PAH was identified by plasma ADMA with a cutoff value of 0.485 µmol/L (P < 0.001) with a specificity of 82.8 % and a sensitivity of 90 %. ES was identified by plasma ADMA with a cutoff value of 0.85 µmol/L (P < 0.05) with a specificity of 85.2 % and a sensitivity of 64.3 %. ADMA levels were significantly decreased after sildenafil therapy for 6 months compared with before therapy levels (0.91 ± 0.22 vs. 0.57 ± 0.30, P < 0.01). Our study suggests that plasma ADMA level may be used as a biomarker for identifying PAH in patients with CHD, assessing pulmonary vascular remodeling, and evaluating the treatment response of CHD patients with PAH to sildenafil.

Long-term outcomes of transcatheter closure of ruptured sinus valsalva aneurysms using patent ductus arteriosus occluders.

BACKGROUND: Transcatheter closure (TCC) of ruptured sinus of Valsalva aneurysm (RSVA) is an alternative strategy to surgery, but there is a lack of long-term outcome data. METHODS AND RESULTS: From 2004 to 2012, 17 patients (8 males, 9 females) were treated with patent ductus arteriosus (PDA) occluders by antegrade venous approach and were followed for 18-102 months. Of the 17 patients, transthoracic echocardiography revealed rupture of the right coronary sinus into the right ventricle in 9 and into the right atrium in 4, and noncoronary sinus rupture into the right ventricle in 3 and into the right atrium in 1. Most (10/17) were in New York Heart Association (NYHA) functional class III or IV. Aortography showed that the size of the defect was 7.71±2.84 mm (4-15 mm). TCC was attempted using PDA occluders 2-5 mm larger than the aortic end of the defects. The device sizes ranged from 8/6 to 18/16 mm (median, 10/8 mm). The procedure was successful in 16 (94.1%), and all of them had complete occlusion at discharge. On a median follow-up of 42 months, 14 patients were in NYHA class I and 2 were in class II, and there was no residual shunt, device embolization, infective endocarditis, or aortic regurgitation. CONCLUSIONS: TCC of RSVA is a safe and effective alternative to surgery with favorable long-term follow-up results.

BCCIP suppresses tumor initiation but is required for tumor progression.

Dysfunctions of genome caretaker genes contribute to genomic instability and tumor initiation. Because many of the caretaker genes are also essential for cell viability, permanent loss of function of these genes would prohibit further tumor progression. How essential caretaker genes contribute to tumorigenesis is not fully understood. Here, we report a "hit-and-run" mode of action for an essential caretaker gene in tumorigenesis. Using a BRCA2-interacting protein BCCIP as the platform, we found that a conditional BCCIP knockdown and concomitant p53 deletion caused rapid development of medulloblastomas, which bear a wide spectrum of alterations involving the Sonic Hedgehog (Shh) pathway, consistent with a caretaker responsibility of BCCIP on genomic integrity. Surprisingly, the progressed tumors have spontaneously lost the transgenic BCCIP knockdown cassette and restored BCCIP expression. Thus, a transient downregulation of BCCIP, but not necessarily a permanent mutation, is sufficient to initiate tumorigenesis. After the malignant transformation has been accomplished and autonomous cancer growth has been established, BCCIP reverses its role from a tumor-initiation suppressor to become a requisite for progression. This exemplifies a new type of tumor suppressor, which is distinct from the classical tumor suppressors that are often permanently abrogated during tumorigenesis. It has major implications on how a nonmutagenic or transient regulation of essential caretaker gene contributes to tumorigenesis. We further suggest that BCCIP represents a paradoxical class of modulators for tumorigenesis as a suppressor for initiation but a requisite for progression (SIRP).

Requirement of mouse BCCIP for neural development and progenitor proliferation.

Multiple DNA repair pathways are involved in the orderly development of neural systems at distinct stages. The homologous recombination (HR) pathway is required to resolve stalled replication forks and critical for the proliferation of progenitor cells during neural development. BCCIP is a BRCA2 and CDKN1A interacting protein implicated in HR and inhibition of DNA replication stress. In this study, we determined the role of BCCIP in neural development using a conditional BCCIP knock-down mouse model. BCCIP deficiency impaired embryonic and postnatal neural development, causing severe ataxia, cerebral and cerebellar defects, and microcephaly. These development defects are associated with spontaneous DNA damage and subsequent cell death in the proliferative cell populations of the neural system during embryogenesis. With in vitro neural spheroid cultures, BCCIP deficiency impaired neural progenitor's self-renewal capability, and spontaneously activated p53. These data suggest that BCCIP and its anti-replication stress functions are essential for normal neural development by maintaining an orderly proliferation of neural progenitors.

Essential roles of BCCIP in mouse embryonic development and structural stability of chromosomes.

BCCIP is a BRCA2- and CDKN1A(p21)-interacting protein that has been implicated in the maintenance of genomic integrity. To understand the in vivo functions of BCCIP, we generated a conditional BCCIP knockdown transgenic mouse model using Cre-LoxP mediated RNA interference. The BCCIP knockdown embryos displayed impaired cellular proliferation and apoptosis at day E7.5. Consistent with these results, the in vitro proliferation of blastocysts and mouse embryonic fibroblasts (MEFs) of BCCIP knockdown mice were impaired considerably. The BCCIP deficient mouse embryos die before E11.5 day. Deletion of the p53 gene could not rescue the embryonic lethality due to BCCIP deficiency, but partially rescues the growth delay of mouse embryonic fibroblasts in vitro. To further understand the cause of development and proliferation defects in BCCIP-deficient mice, MEFs were subjected to chromosome stability analysis. The BCCIP-deficient MEFs displayed significant spontaneous chromosome structural alterations associated with replication stress, including a 3.5-fold induction of chromatid breaks. Remarkably, the BCCIP-deficient MEFs had a ∼20-fold increase in sister chromatid union (SCU), yet the induction of sister chromatid exchanges (SCE) was modestly at 1.5 fold. SCU is a unique type of chromatid aberration that may give rise to chromatin bridges between daughter nuclei in anaphase. In addition, the BCCIP-deficient MEFs have reduced repair of irradiation-induced DNA damage and reductions of Rad51 protein and nuclear foci. Our data suggest a unique function of BCCIP, not only in repair of DNA damage, but also in resolving stalled replication forks and prevention of replication stress. In addition, BCCIP deficiency causes excessive spontaneous chromatin bridges via the formation of SCU, which can subsequently impair chromosome segregations in mitosis and cell division.

Synthesis, human telomerase inhibition and anti-proliferative studies of a series of 2,7-bis-substituted amido-anthraquinone derivatives.

Telomerase is important in tumor initiation and cellular immortalization. Given the striking correlations between telomerase activity and proliferation capacity in tumor cells, telomerase had been considered as a potentially important molecular target in cancer therapeutics. A series of 2,7-diamidoanthraquinone were designed and synthesized. They were evaluated for their effects on telomerase activity, hTERT expression, cell proliferations, and cytotoxicity. In the series, compounds (6, 10, 13, 16, 18, 19, 20-22, and 24) showed potent telomerase inhibitory activity, while compounds 19, 21, and 22 activated hTERT expression in normal human fibroblasts. The results indicated that 2,7-diamidoanthraquinones represent an important class of compounds for telomerase-related drug developments. Compounds 8, 16, 18, 26, and 32 were also selected by the NCI for Screening Program and demonstrated high anti-proliferative activity against 60 human cancer cell lines. Structure-activity relationships (SAR) study revealed that the test compounds with side chains two carbon spacer between amido and amine are important structural moiety for telomerase inhibition. Although the exact mechanism of how this amine group contributes to its activity is still unclear, however, the amine group in the extended arm of the bis-substituted anthraquinone might contribute to proper binding to the residues within the grove of G-quadruplex structure. Our results indicated that the 2,7-disubstituted amido-anthraquinones are potent telomerase inhibitors that have the potential to be further developed into novel anticancer chemotherapeutic agents.

Synthesis and human telomerase inhibition of a series of regioisomeric disubstituted amidoanthraquinones.

Telomerase is the enzymatic activity that maintains the ends of eukaryotic chromosomes. Telomerase activity is detected in most tumor cells whereas it is low or undetectable in most normal somatic cells. Expression of the telomerase catalytic component, the human telomerase reverse transcriptase (hTERT), is believed to be controlled primarily at the level of transcription. Because of this selective expression property of telomerase, it has been touted as a specific target for antitumor chemotherapeutics. However, a concern for the applicability of telomerase inhibitors is that they require a long lag time for telomeres to be shortened to critical length before cancer cells stop proliferating. Here we investigate telomerase inhibitory, cytotoxicity and the hTERT repressing effects on a number of synthesized 2,6-diamidoanthraquinones and 1,5-diamidoanthraquinones as compared to their disubstituted homologues. We found that several of the 1,5-diamidoanthraquinones and 2,6-diamidoanthraquinones inhibited telomerase activity effectively with IC50 at the sub-micro to micro molar range and caused acute cytotoxicity to cancer cells with EC50 similar or better than that of mitoxantrone. Particularly, 2,6-diamidoanthraquinone with 2-ethylaminoacetamido side chains 33, even though not affecting cell proliferation, showed to be endowed with a strong telomerase effect, probably related to a marked stabilization of the G-quadruplex-binding structure. The results suggested that these compounds caused multiple effects to cancer cells. More significantly, they overcome the long lag period problem of classical telomerase inhibitors that they are also potent cytotoxic agents. These results greatly expand the potential of tricyclic anthraquinone pharmacophore in preventive and/or curative therapy.

Establishing cell-based reporter systems for the analysis of hTERT expression.

Telomeres are the protective structures at the end of eukaryotic chromosomes. Telomerase is a ribonucleoprotein that contains both an RNA and a protein component for the maintenance of telomere length. Telomerase activity is detected in the majority of malignant tumors, but not in normal somatic cells, suggesting that telomerase reactivation is a crucial step in cell immortality and carcinogenesis. The mechanism of how telomerase is activated during tumorigenesis remains unclear. However, the expression of the human telomerase reverse transcriptase (hTERT) gene, which encodes the catalytic protein subunit of human telomerase, has been shown to be the major determining factor. To gain insight into the mechanisms regulating hTERT expression and to facilitate the screening of agents that affect hTERT expression, we have established cell-based systems for monitoring hTERT expression. We linked the hTERT promoter to two different reporter genes encoding green fluorescence protein (GFP) and secreted alkaline phosphatase (SEAP), respectively. These constructs were then transfected into H1299 and hTERT-BJ1 cells. Stable clones harboring these DNA constructs were isolated. In these cells, hTERT expression can be monitored through the quantification of GFP or SEAP activity on an automatic plate reader. Using these systems, we have identified several small molecule compounds that affect the expression of telomerase.