Effects of genistein and daidzein on hippocampus neuronal cell proliferation and BDNF expression in H19-7 neural cell line

OBJECTIVES

Estrogen replacement therapy (ERT) reduces the risk of Alzheimer's disease and symptoms in postmenopausal and elderly women. However, ERT is associated with increased risk of uterine and breast cancer. Dietary phytoestrogens have been suggested as a potential alternative to ERT, while little information is available regarding the effects and the underlying mechanisms of such treatment on central neuron function. The present study aimed to determine the effects of phytoestrogens including genistein and daidzein on the proliferation and survival of the hippocampus neural cells, which are of importance in learning and memory function.

MEASUREMENTS

H19-7/IGF-IR neural cell line was cultured in DMEM absented of serum for 72 h, and treated with various concentrations of genistein, daidzein or 17β-estradiol. Neuronal cell viability and proliferation were determined by MTT and BrdU assay, respectively Cell cycle analysis was performed using flow cytometry. The effects of genistein and daidzein on brain-derived neurotrophic factor (BDNF) mRNA and protein expression were determined by RT-PCR and ELISA, respectively. The effect of Trk receptors inhibitor on genistein and daidzein - induced hippocampus neuronal cell proliferation was also examined.

RESULTS

17β-estradiol, genistein and daidzein ranged from 20 nM to 2000 nM significantly promoted hippocampus neuronal cell viability and proliferation. Similar to the effect of 17β-estradiol, genistein and daidzein induced an increase in the percentage of cells in S phase. Genistein and daidzein significantly increased the expression of BDNF mRNA and protein levels. The effect of genistien and daidzein on hippocampus neuronal proliferation was blocked by K252a, a selective Trk receptors inhibitor.

CONCLUSION

This study concluded that genistein and daidzein improved hippocampus neuronal cell viability and proliferation in vitro. These neuroprotective effects might be mediated by BDNF-Trk pathway.

The pathogenic role of autoantibodies in pemphigus vulgaris

Pemphigus vulgaris (PV) is a severe autoimmune bullous disease involving both the skin and mucosal areas, and characterized by intraepithelial flaccid blisters and erosions. The pathogenesis of this disease is not yet completely understood, but novel insights into desmoglein biology and autoantibody pathogenesis have recently been published. Acantholysis in PV seems to result from a collective action of autoantibodies against various keratinocyte self antigens, of which desmogleins 1 and 3 are the most important. Additional antigens including desmocollins and nondesmosome components, such as the mitochondrion, might take part in disease activation. Recently, apoptosis was reported as a possible underlying mechanism of acantholysis. Furthermore, apoptolysis is believed to be the link between suprabasal acantholytic and cell-death pathways. We review the possible hypotheses of the pathogenesis of PV: the desmoglein compensation theory, the antibody-induced apoptosis theory, the basal-cell shrinkage hypothesis and the newly published apoptolysis theory.

Electron Microscopy Characterization Of Epitaxial Growth Of Ag Deposited On Mgo Microcubes

The crystalline structure, the morphology and the chemistry of small Ag particles vacuum-deposited on preheated MgO microcubes were characterized by in situ and ex situ electron microscopy and surface analysis techniques. Observations were made of the nucleation and growth of Ag clusters on MgO surfaces and along surface steps. It is found that Ag particles deposited onto clean MgO crystals have an epitaxial orientation relationship of (100)Agll(100)MgO with [100]Agll[00]MgO. Prior to air exposure Ag particles are stable under the electron beam but they become unstable upon exposure to air. During electron irradiation on air-exposed samples terraces are formed on the surfaces of MgO cubes, preferentially near Ag particles and at their interfaces with the substrate. The stability of vacuum-deposited Ag particles and the growth of the terraces on MgO microcubes seem to depend on air exposure of the sample.

Color Doppler twinkling artifact in fetuses with echogenic intracardiac foci: echocardiographic observation and clinical significance

OBJECTIVE

To evaluate echocardiographic characteristics and clinical relevance of color Doppler twinkling artifacts in fetuses with isolated echogenic intracardiac foci (EIF).

METHODS

This study included 50 fetuses with EIF, at 18-38 weeks of gestation. Echocardiographic examination, which was performed using a 1.0-5.0-MHz phased array probe, included gray-scale, color and spectral Doppler imaging. Twinkling artifacts were assessed using fetal color Doppler echocardiography on isolated EIF situated in the left and/or right ventricles. The prevalence, appearance and clinical relevance of the color Doppler twinkling artifacts were analyzed.

RESULTS

Eight of 50 fetuses with EIF (16%) showed color Doppler twinkling artifacts, which appeared as a rapidly changing color complex seen persistently behind the EIF. The spectra obtained in all eight with color Doppler artifacts were composed of straight vertical bands occurring in mid to late systole and early diastole. After birth, none of 50 fetuses with EIF had structural heart diseases or showed clinical signs of cardiac failure.

CONCLUSIONS

Color Doppler twinkling artifacts from isolated EIF occur in some fetuses and may be considered as an additional echocardiographic feature of EIF. Attention should be paid to the identification and interpretation of these artifacts so that they may be accurately distinguished from true color flow generated by atrioventricular valvular regurgitation jets.

Unusual amplification pattern by SSP HLA-B typing led to discovery of a novel HLA-C allele

We report here the unique sequence of a novel human leucocyte antigen (HLA)-C allele resulted in amplification of a product with a primer pair used in sequence-specific primer (SSP) HLA-B typing, which led subsequently to identification of a new allele of Cw*0339 by sequence-based typing method. This new allele is closely related to Cw*031101 with only two nucleotide changes from T to G at position 97, and T to C at position 105 in the exon 2 region of HLA-C locus. The first nucleotide substitution causes an amino acid alteration from tyrosine to aspartic acid at amino acid residue 9 (Y to D), while the second one keeps alanine at residue 11 unchanged. Most interestingly, the nucleotide change from T to G at position 97 makes it identical to the 3' end sequence of one SSP of the commercial HLA-B SSP typing kit we were using. In this specific case, it resulted in amplification of a product of HLA-C gene instead of B gene.

Time-frequency characterization of atrial fibrillation from surface ECG based on Hilbert-Huang transform

In this paper, based on Hilbert-Huang transform (HHT), we develop a new non-invasive time-frequency analysis method to characterize the dynamic behaviour of atrial fibrillation (AF) from surface ECG. We first extract f waves from single-lead ECG records of AF patients using PCA analysis. To capture the non-stationary behaviours of AF signals at different time scales, we use HHT to find the Hilbert spectrum and instantaneous frequency (IF) distribution of residual signals from principal component analysis. Two important feature variables, namely mean IF (mIF) and index of frequency stability over time (IS), are derived from the IF distribution, and in combination will be able to effectively discriminate two different AF types: self-terminating and non-terminating termination. The proposed AF signal decomposition and analysis method will help us efficiently differentiate individual AF patients, advance our understanding of AF mechanisms, and provide useful guidelines for improving administration of AF patients, especially paroxysmal AF.

Synergistic antileukemic effects between ABT-869 and chemotherapy involve downregulation of cell cycle-regulated genes and c-Mos-mediated MAPK pathway

Internal tandem duplications (ITDs) of fms-like tyrosine kinase 3 (FLT3) receptor play an important role in the pathogenesis of acute myeloid leukemia (AML) and represent an attractive therapeutic target. ABT-869 has demonstrated potent effects in AML cells with FLT3-ITDs. Here, we provide further evidence that ABT-869 treatment significantly downregulates cyclins D and E but increases the expression of p21 and p27. ABT-869 induces apoptosis through downregulation of Bcl-xL and upregulation of BAK, BID and BAD. We also evaluate the combinations of ABT-869 and chemotherapy. ABT-869 demonstrates significant sequence-dependent synergism with cytarabine and doxorubicin in cell lines and primary leukemia samples. The optimal combination was validated in MV4-11 xenografts. Low-density array analysis revealed the synergistic interaction involved in downregulation of cell cycle and mitogen-activated protein kinase pathway genes. CCND1 and c-Mos were the most significantly inhibited targets on both transcriptional and translational levels. Treatment with short hairpin RNAs targeting either CCND1 or c-Mos further sensitized MV4-11 cells to ABT-869. These findings suggest that specific pathway genes were further targeted by adding chemotherapy and support the rationale of combination therapy. Thus, a clinical trial using sequence-dependent combination therapy with ABT-869 in AML is warranted.

ABT-869, a novel multi-target receptor tyrosine kinase inhibitor (RTKI), combined with chemotherapy is synergistic in the therapy of acute myeloid leukemia cells with FLT3-ITD mutation (FLT3-AML)

13064

Background: Internal tandem duplications (ITDs) of fms-like tyrosine kinase 3 (FLT3) receptor are identified in 20–25% of adult AML patients associated with poor prognosis. ABT-869 is active in FLT3-AML and is currently under clinical investigaton. We hypothesize that the combination of ABT-869 with chemotherapy can improve the therapeutic index in FLT3-AML. Methods: Using Calcusyn software, the additive, synergistic or antagonistic effect of ABT-869 with concurrent or sequential cytosine arabinoside (Ara-C) or doxorubicin (Dox) was measured in MV4–11 and MOLM-14 cells. The synergistic combination sequence was further tested in a MV4–11 xenograft model in four groups (10 mice/group) including control, Ara-C, ABT-869, and combination (Ara-C first for 4 days, then daily ABT-869). Cell cycle analysis and apoptosis and signal pathway assays were performed in vitro and in vivo. Results: ABT-869 induced dose- and time-dependent apoptosis on FLT3-AML cells resulting in down regulation of p-FLT3, p-STAT5, Bcl-XL and up regulation of p53 and BID. ABT-869 caused G1-phase arrest and the removal of cells in the S- and G2/M-phase mediated by reduction of cyclins D and E. We observed significant synergistic effect with Ara-C or Dox first, followed by ABT-869, as well as in concurrent treatment with ABT-869 and Dox. Simultaneous treatment with ABT-869 and Ara-C only achieved additive effect. Conversely, we found an antagonistic effect in the sequence of pretreatment of ABT-869 followed by chemotherapy. In a MV4–11 xenograft model, all mice succumbed to leukemia in the control and Ara-C groups (median survival = 53 and 55.5 days respectively). Combination therapy gave a faster reduction of tumor volume compared to ABT-869 treatment alone (p=0.03) without recurrence of leukemia in either group by day 67. In vivo immunohistochemistry (IHC) analysis revealed ABT-869 potently inhibited VEGF and phosphor-ERK. Conclusions: ABT-869 can be given after Ara-C or Dox to act synergistically. Our study suggests that combinations of RTKIs with chemotherapy should be carefully tested prior to clinical protocol development. A clinical trial of such combination therapy in FLT3-AML is warranted.

No significant financial relationships to disclose.

Percutaneous interventions on severe coarctation of the aorta: a 21-year experience

Different percutaneous interventions can be used to treat coarctation of the aorta. However, a great amount of information is still needed regarding the long-term course. This article reviews our experience spanning 21 years in the percutaneous treatment of aortic coarctation. Four different conditions for treatment were considered. The first condition 1 (group 1) was balloon angioplasty in neonates and infants with untractable heart failure (n = 54; mean age, 1.2 +/- 1.4 months). After balloon angioplasty, most infants sustained significant clinical improvement. However, 9 patients died in the hospital (17%). As a result, we monitored the course of the 45 survivors during a mean period of 10 +/- 6 years (range, 1-19). During this follow-up period, 17 patients needed a single additional intervention on coarctation (8 underwent surgery and 9 were treated percutaneously). After this second treatment, 11 patients needed one or more further interventions. The actuarial survival probability was 83% at 19 years, with 43% of patients remaining surgery free and 23% reintervention free. The second condition (group 2) was balloon angioplasty in children and adults with coarctation of the aorta before the stenting era (n = 28; mean age, 13 +/- 8 years). After treatment, serial hemodynamic and angiographic studies were performed. The long-term relief was higher in patients with a discrete type of coarctation. The rate of late aneurysm formation was 6%. The third condition (group 3) was stent palliation in infants and children younger than the age of 6 years (n = 17; mean age, 2.1 +/- 1.7 years). The stent was implanted for nondilatable stenoses, as a nondefinitive procedure. Stent palliation provides complete initial relief in hypoplastic coarctations or life-threatening conditions. However, further stent expansion is required to ensure adequate stent diameter in the growing aortic wall. In addition, late intrastent proliferation may occur in small stent diameters (18%) and aneurysm formation in hypoplastic coarctations (18%). Both late complications can be managed percutaneously. The fourth condition (group 4) was stent repair of severe aortic coarctation in adults, adolescents, and children older than the age of 6 years (n = 73; mean age, 20 +/- 12 years). Significant relief was observed after treatment, which persisted at follow-up. One patient died at treatment (1.3%). After a mean follow-up of 5 +/- 3 years, all 72 patients remained symptom free and no restenosis or late aneurysm were detected.