Correlation between the contrast-enhanced ultrasound image features and axillary lymph node metastasis of primary breast cancer and its diagnostic value

Purpose To analyze the correlation between contrast-enhanced ultrasound image features and axillary lymph node metastasis of primary breast cancer and its diagnostic value. Methods In this study, 64 patients with axillary lymph node metastasis of primary breast cancer diagnosed and treated in our hospital from February 2011 to March 2013 were collected as an observation group, and 54 patients without axillary lymph node metastasis were collected as a control group. All patients underwent a contrast-enhanced ultrasound examination, and the correlation between the contrast-enhanced ultrasound image features and axillary lymph node metastasis and its diagnostic value were analyzed. They were divided into two groups according to their survival conditions: the group with good efficacy and group with poor efficacy, and the prognostic factors of breast cancer in the two groups were analyzed. Results There were statistical differences in the peripheral acoustic halo, blood flow classification, ratio of length to diameter (L/D), maximum cortical thickness, and enhancement mode of lymph nodes between the two groups (p < 0.05). The area under ROC curve for diagnosis of axillary lymph node metastasis by contrast-enhanced ultrasound was 0.854, sensitivity was 83.33%, and specificity was 87.5%; L/D and enhancement mode were independent prognostic factors for breast cancer. Conclusions Contrast-enhanced ultrasound image features have diagnostic and prognostic value for axillary lymph node metastasis of breast cancer (AU)

Correlation between the contrast-enhanced ultrasound image features and axillary lymph node metastasis of primary breast cancer and its diagnostic value.

PURPOSE: To analyze the correlation between contrast-enhanced ultrasound image features and axillary lymph node metastasis of primary breast cancer and its diagnostic value. METHODS: In this study, 64 patients with axillary lymph node metastasis of primary breast cancer diagnosed and treated in our hospital from February 2011 to March 2013 were collected as an observation group, and 54 patients without axillary lymph node metastasis were collected as a control group. All patients underwent a contrast-enhanced ultrasound examination, and the correlation between the contrast-enhanced ultrasound image features and axillary lymph node metastasis and its diagnostic value were analyzed. They were divided into two groups according to their survival conditions: the group with good efficacy and group with poor efficacy, and the prognostic factors of breast cancer in the two groups were analyzed. RESULTS: There were statistical differences in the peripheral acoustic halo, blood flow classification, ratio of length to diameter (L/D), maximum cortical thickness, and enhancement mode of lymph nodes between the two groups (p < 0.05). The area under ROC curve for diagnosis of axillary lymph node metastasis by contrast-enhanced ultrasound was 0.854, sensitivity was 83.33%, and specificity was 87.5%; L/D and enhancement mode were independent prognostic factors for breast cancer. CONCLUSIONS: Contrast-enhanced ultrasound image features have diagnostic and prognostic value for axillary lymph node metastasis of breast cancer.

Evolution analysis of EUV radiation from laser-produced tin plasmas based on a radiation hydrodynamics model.

One of fundamental aims of extreme ultraviolet (EUV) lithography is to maximize brightness or conversion efficiency of laser energy to radiation at specific wavelengths from laser produced plasmas (LPPs) of specific elements for matching to available multilayer optical systems. Tin LPPs have been chosen for operation at a wavelength of 13.5 nm. For an investigation of EUV radiation of laser-produced tin plasmas, it is crucial to study the related atomic processes and their evolution so as to reliably predict the optimum plasma and experimental conditions. Here, we present a simplified radiation hydrodynamic model based on the fluid dynamic equations and the radiative transfer equation to rapidly investigate the evolution of radiation properties and dynamics in laser-produced tin plasmas. The self-absorption features of EUV spectra measured at an angle of 45° to the direction of plasma expansion have been successfully simulated and explained, and the evolution of some parameters, such as the plasma temperature, ion distribution and density, expansion size and velocity, have also been evaluated. Our results should be useful for further understanding of current research on extreme ultraviolet and soft X-ray source development for applications such as lithography, metrology and biological imaging.

Direct, reagentless electrochemical detection of the BIR3 domain of X-linked inhibitor of apoptosis protein using a peptide-based conducting polymer sensor.

In this work, we report a reagentless electrochemical peptide (AVPFAQKG) sensor to directly detect the BIR3 domain of X-linked inhibitor of apoptosis protein (XIAP-BIR3). The bioreceptor was based on a conducting copolymer film electrosynthesized from juglone and a juglone-peptide conjugate (JP) newly designed. The peptide-protein interactions generated an important increase of steric hindrance at the interface and a current decrease (signal off) of the redox reaction from quinone embedded in the polymer backbone as evidenced by Square Wave Voltammetry. This allowed a specific and sensitive detection of XIAP-BIR3 with a detection limit of 1 nM (13 ng mL(-1)). The peptide-protein complex could be then dissociated by adding the free precursor peptide (AVPFAQKG) into solution, causing a shift-back on the signal, i.e. an increase in the current intensity (signal-on). This "off-on" detection sequence was used in this work as a double verification of the specificity and this approach can be employed as a general way to increase the reliability of the results. In general, the approach described in this work may be inspired to develop other direct and reagentless electrochemical protein assays with high specificity and sensitivity.

E-assay concept: detection of bisphenol A with a label-free electrochemical competitive immunoassay.

A label-free electrochemical immunosensor was developed by electropolymerization of N-(3-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)propyl) 3-(5-hydroxy-1,4-dihydro-1,4-dioxonaphthalen-2(3)-yl)propionamide (JugBPA). By combination with an antibody directed to bisphenol A (αBPA), this conducting polymer-based biosensor can detect BPA directly with a limit of detection of 2pgmL(-1). Square wave voltammetry shows that the polymer film presents a current decrease upon anti-BPA binding and an opposite current increase upon BPA addition in solution. This electrochemical immunosensor (E-assay) also shows high selectivity towards closely related compounds (bisphenol A dimethacrylate, and dibutyl phthalate). The E-assay concept described here could be a promising tool for simple, low-cost and reagentless on-site environmental monitoring.

Lack of association between STK39 and hypertension in the Chinese population.

Genome-wide association study (GWAS) has identified serine/threonine kinase 39 (STK39) as a candidate gene for hypertension. A replication study provided supporting evidence that STK39 functional polymorphism rs35929607 was associated with hypertension. Recently, another study also showed rs6749447 within the STK39 was associated with blood pressure responses. However, these studies were all conducted in Caucasians. Thus, we carried out a case-control study to test whether STK39 is a common candidate gene for hypertension, and to examine the interaction of genetic factors and non-genetic risk factors in the Chinese population. Thousand twenty four hypertensive cases and 1024 controls were genotyped for five polymorphisms. Four single-nucleotide polymorphisms (SNPs) are located within STK39, and rs4977950, the SNP that showed the strongest signal is located in a gene desert. Results indicated that none of these SNPs was associated with hypertension in the Chinese population. Logistic regression analysis found body mass index (BMI) and triglyceride level were higher in the hypertension group when compared with the control group. Multifactor dimensionality reduction analysis indicated that the interaction between BMI and rs4977950 may have an impact on hypertension. Taken together, the present study found no evidence that STK39 was associated with hypertension in the Chinese population. Instead, non-genetic risk factors such as BMI have an important role in Chinese hypertensive subjects, and the 'missing inheritability' requires further investigation.

A label-free electrochemical immunosensor for direct, signal-on and sensitive pesticide detection.

A new electropolymerizable monomer, [N-(6-(4-hydroxy-6-isopropylamino-1,3,5-triazin-2-ylamino)hexyl) 5-hydroxy-1,4-naphthoquinone-3-propionamide], has been designed for use in a label-free electrochemical immunosensor when polymerized on an electrode and coupled with a monoclonal anti-atrazine antibody. This monomer contains three functional groups: hydroxyl group for electropolymerization, quinone group for its transduction capability, and hydroxyatrazine as bioreceptor element. Square wave voltammetry shows that the polymer film, poly[N-(6-(4-hydroxy-6-isopropylamino-1,3,5-triazin-2-ylamino)hexyl) 5-hydroxy-1,4-naphthoquinone-3-propionamide], presents negative current change following anti-atrazine antibody complexation and positive current change after atrazine addition in solution. This constitutes a direct, label-free and signal-on electrochemical immunosensor, with a very low detection limit of ca. 1 pM, i.e. 0.2 ng L(-1), one of the lowest reported for such immunosensors. This is far lower than the detection limit required by the European Union directives for drinkable water and food samples (0.1 µg L(-1)). The strategy described has great promise for the development of simple, cost-effective and reagentless on-site environmental monitors.

The excitation energies, ionization potentials, and oscillator strengths of neutral and ionized species of Uuq (Z=114) and the homolog elements Ge, Sn, and Pb.

Multiconfiguration Dirac-Fock method is employed to calculate the excitation energies, ionization potentials, oscillator strengths, and radii for all neutral and up to four times ionized species of element Uuq, as well as the homolog elements Ge, Sn, and Pb. Using an extrapolative scheme, improved ionization potentials of Uuq were obtained with an uncertainty of less than 2000 cm(-1). Two relatively stronger resonance transitions are predicted for the element Uuq. In particular, the strongest line in Uuq, corresponding to the [6d(10)7s(2)7p(3/2)8s(1/2)](1)-->[6d(10)7s(2)7p(3/2)(2)](2) transition at 22 343 cm(-1), just lies in the prime energy region of experimental measurement.

A new acetylcholinesterase inhibitor with anti-PAF activity modulates oxidative stress and pro-inflammatory mediators release in stimulated RAW 264.7 macrophage cells. Comparison with tacrine.

Inflammatory injury and induction of oxidative stress have been implicated as causative factors in neurodegenerative diseases such as Alzheimer's disease (AD). Using LPS-stimulated RAW 264.7 macrophages as a model of inflammatory injury, LPS was found to stimulate ROS production (159%), GSH depletion (15%) and loss of mitochondrial activity (32%) as well as TNFalpha release (40%), and NO production (13.7 times), all parameters involved in AD. PMS777, a tetrahydrofuran derivative, designed as a dual PAF and acetylcholinesterase inhibitor, was found to decrease ROS (up to 32%) and NO production (up to 5 times), TNFalpha release (33%). PMS777 also prevents loss of mitochondrial activity, and GSH depletion. In contrast, tacrine was found to decrease ROS production (57% up to 102%) and TNFalpha level (up to 30%). It decreases NO release only at the highest concentrations without preventing loss of mitochondrial activity and GSH depletion. In this study, we show that PMS777 is strongly anti-inflammatory against LPS-induced responses in RAW 264.7. Differential effects between PMS777 and tacrine could be attributed to the anti-PAF activity of PMS777 which was able to fight inflammatory events and oxidative injury whereas tacrine only minimizes them. PMS777 could open a new approach in the treatment of AD.

Study of PMS777, a new type of acetylcholinesterase inhibitor, in human HepG2 cells. Comparison with tacrine and galanthamine on oxidative stress and mitochondrial impairment.

Acetylcholinesterase inhibitors are commonly used as cognitive enhancers for dementia in aged people. Among them, tacrine (THA) but not galanthamine, was shown to exhibit hepatotoxicity which reduces its clinical use. PMS777, both a PAF antagonist and a new potent acetylcholinesterase inhibitor was recently demonstrated to reverse scopolamine-induced amnesia in mice without toxicity. In the present study, the effects of THA, galanthamine and PMS777 were compared in HepG2 cells on the oxidative parameters involved in the reported hepatotoxicity of THA. THA (> or = 10 microM) induced an oxidative stress as shown by elevated ROS and MDA production and by a decrease in GSH level. Moreover, mitochondrial membrane potential and redox status were decreased. At low concentrations (< or =10 microM), there was no significant disturbance. None of the oxidative stress markers was affected by PMS777 up to the maximum concentration tested and it is suggested that PMS777 is not cytotoxic for HepG2 cells. Galanthamine was also without cytotoxicity. Our results suggest that the toxic effect of THA above 10 microM may be caused by drug-induced mitochondrial energization impairment and destabilisation of membrane phospholipids associated with an oxidative stress. In contrast by preventing these dysfunctions, PMS777 could be safer than THA.

First observation of atomic levels for the element fermium (Z=100).

The atomic level structure of the element fermium was investigated for the first time using a sample of 2.7x10(10) atoms of the isotope 255Fm with a half-life of 20.1 h. The atoms were evaporated from a filament and stored in the argon buffer gas of an optical cell. Atomic levels were sought by the method of resonance ionization spectroscopy using an excimer-dye-laser combination. Two atomic levels were found at wave numbers (25 099.8+/-0.2) and (25 111.8+/-0.2) cm(-1). Partial transition rates to the 5f(12)7s(2) (3)H(e)(6) ground state have been determined from their saturation characteristics. Multiconfiguration Dirac-Fock calculations suggest that the leading orders of these levels could be the 5f(12)7s7p (5)I(o)(6) and 5f(12)7s7p (5)G(o)(5) terms.

Structure-activity relationships in platelet-activating factor (PAF). 11-From PAF-antagonism to phospholipase A(2) inhibition: syntheses and structure-activity relationships in 1-arylsulfamido-2-alkylpiperazines.

1-Benzoyl-2-alkyl piperazines are strong inhibitors of Group I and II secreted PLA(2)s. An improvement of their activity was obtained by replacing the amide function by a sulfamide and by introduction of electrodonor substituents on the para position of the benzenesulfonyl moiety. Neither the position on one of the carbon of the piperazine ring nor the absolute configuration of this carbon have an effect on the affinity for one or the other group of PLA(2), but the lipophilicity remains for these series an essential parameter. In addition structure-activity relationships allow new hypothesis on interaction of these piperazine derivatives with the catalytic site of PLA(2)s.

Generation of monoclonal antibodies specifically directed against the proximal zinc finger of HIV type 1 NCp7.

The HIV-1 NCp7 contains two spatially close zinc fingers, required for the production of infectious particles. To investigate in more detail the function of the zinc finger domain, monoclonal antibodies were generated with a cyclic analog of the NCp7 proximal zinc finger. This analog was shown to bind zinc ions and to preserve the highly folded structure of the native peptide (Dong C-Z et al.: J Am Chem Soc 1995;117:2726-2731). We report here two monoclonal antibodies (2B10 and 4D3), which are the first monoclonal antibodies directed against CCHC NCp7 zinc fingers. Dot-blot experiments revealed that a few nanograms of synthetic NCp7 can be detected on a nitrocellulose membrane. Whereas 2B10 appears specific for an epitope located in sequence 19-27 of NCp7, 4D3 appears to be structurally specific. Immunocomplex affinities were evaluated, using BIAcore technology, to be up to 1 and 10 nM, respectively, for 2B10 and 4D3 in 100 mM NaCl. These antibodies were able to recognize NCp7 in the Gag polyprotein precursor and were shown to immunoprecipitate NCp7 from a cell supernatant. Moreover, NCp7-Vpr interaction mediated by the zinc fingers is inhibited by 2B10, emphasizing the role of these domains in the protein-protein complex. These results indicate that 2B10 and 4D3 behave as useful tools for studying both NC protein functions during the course of virion morphogenesis and the role played by its zinc finger domain at various steps in the retroviral life cycle.

Structure-activity relationships in platelet-activating factor (PAF). 10. From PAF antagonism to inhibition of HIV-1 replication.

Excessive levels of PAF and cells of macrophage lineage appear to play an important role in neuronal cell injury, inflammatory syndrome, and HIV replication in CNS resulting in AIDS dementia complex (ADC). The beneficial effects of PAF receptor antagonists are evident and give rise to expected therapeutic strategies for neurotrauma. Piperazine derivatives bearing a "cache-oreilles" (ear-muff) electronic distribution are able to inhibit in vitro PAF effects and, thus, could be used in pathologies where this mediator is involved. Therefore, their potential anti-HIV activity was investigated, and we find that (i) these PAF antagonists are effectively active in HIV-infected monocyte-derived macrophages (MDM) but there is no correlation between both anti-HIV and anti-PAF activities; (ii) the presence of a carbamate function (compounds 1a-d) is favorable to the antiviral activity; (iii) the lipophilicity of the substituent on the piperazinic cycle seems to be less important for the anti-PAF activity than for the antiviral one. Our leading compound, PMS 601 (compound 1a), presents a dual activity with IC(50) of 8 and 11 microM for anti-PAF and anti-HIV activity, respectively, without cytotoxic events at 1000 microM in MDM. Although its mode of action is not clearly defined, these data suggest that PMS 601, which displays no effect on acellular reverse transcriptase or protease tests, deserves further investigation in the treatment of HIV-1-associated dementia.

A mimic of HIV-1 nucleocapsid protein impairs reverse transcription and displays antiviral activity.

Combined inhibition of HIV-1 reverse transcriptase and protease has significantly improved the treatment of AIDS. Nevertheless, resistance to these drugs occurs rapidly because of viral mutations, emphasizing the importance of identifying novel retroviral targets to develop new drug combinations. The critical role played by the nucleocapsid protein NCp7 of HIV-1 at different steps of the retrovirus life cycle makes it an attractive target for the development of new antiviral agents. NCp7 contains two highly conserved zinc fingers and is characterized by a three-dimensional structure that cannot be modified without a complete loss of infectivity of mutated viruses. Based on these structural data, we report that RB 2121, a cyclic peptide designed to mimic several essential biological determinants of NCp7, displays antiviral activity by inhibiting HIV-1 replication in CEM-4 cells infected by HIV-1. In vitro, RB 2121 does not interfere with HIV-1 cell entry and viral enzymes but is able to inhibit the annealing activities of NCp7 by recognizing nucleic acids. Analysis of proviral DNA synthesis by means of PCR has shown that RB 2121 acts at an early step of the retrovirus life cycle by inducing a dose-dependent reduction in transcribed DNA levels through inhibition of NCp7-reverse transcriptase interaction. Because of its original mechanism of action, RB 2121 provides an interesting lead for the rational development of new anti-HIV-1 agents that could be associated advantageously with enzyme inhibitors to counteract rapid virus mutations and resistance problems observed in tritherapies.

Synthesis and biological activities of fluorescent acridine-containing HIV-1 nucleocapsid proteins for investigation of nucleic acid-NCp7 interactions.

Specific interactions between the 72-amino acid nucleocapsid protein NCp7 of the human immunodeficiency virus, type 1 and the genomic RNA are essential for virus replication. Studies on the mechanism of action of NCp7 require a direct visualization of its complexes with nucleic acids and the determination of binding affinities. To facilitate these investigations, fluorescent NCp7 derivatives were developed by introduction in the NCp7 sequence of a non-natural amino acid, (S)-beta-(9-acridinyl)alanine (Aca) obtained by a chiral synthetic method. Three fluorescent NCp7 derivatives were obtained by introducing this amino acid at different positions. As shown by NMR, the three-dimensional structure of NCp7 is not altered by introduction of Aca. The fluorescent peptides were found to be as potent as their precursors in interacting with nucleic acids and in promoting HIV-1 genomic RNA dimerization. Moreover, because of their fluorescent properties, these NCp7s can be used at submicromolar concentrations to directly visualize and quantify protein-nucleic acid interactions in solution or after gel electrophoresis. This could facilitate the development of new antiviral agents aimed at inhibiting the functions of NCp7 and studies on the intracellular traffic of NCp7 within the preintegration complex.

1H NMR structure and biological studies of the His23-->Cys mutant nucleocapsid protein of HIV-1 indicate that the conformation of the first zinc finger is critical for virus infectivity.

The nucleocapsid protein NCp7 of human immunodeficiency virus type 1 (HIV-1), which has key functions in the virus life cycle, possesses two zinc fingers of the CX2CX4HX4C type characterized by three successive loops containing a tetrahedrally coordinated zinc atom. The replacement of any cysteine by a serine in either finger has been shown to result in the production of noninfectious viruses, probably by impairing the biological functions of NCp7. In order to more precisely elucidate the structural role of the zinc finger motif, His23 was replaced by Cys in the proximal finger of the peptide (13-64)NCp7 which retains NCp7 activities in vitro. The peptide Cys23(13-64)NCp7 was synthesized by solid phase and studied by 2D 1H NMR and molecular modeling. The His to Cys modification causes important structural modifications of the N-terminal zinc finger which impair the spatial proximity of the two zinc fingers as shown by the disappearance of several interresidue NOEs. The side chains of Val13, Lys14, Phe16, Thr24, Ala25, Trp37, Gln45, and Met46, which are thought to be involved in nucleic acid recognition, are no longer found clustered in the Cys23(13-64)NCp7 mutant as they are in the wild-type NCp7 structure. In vitro, Cys23(13-64)NCp7 is unable to tightly interact with the viral RNA or replication primer tRNA(Lys,3). The Cys23(NCp7) mutation was introduced into an infectious HIV-1 molecular clone, and virions produced upon DNA transfection into cells were analyzed for their viral protein and RNA compositions as well as for their infectivity. Results show that, while the Cys23(NCp7) mutation does not impair virion production, viruses contain a low amount of degraded viral RNA and are not infectious. These findings suggest that a bona fide conformation of the HIV-1 NCp7 is critical for the packaging of viral RNA, its stability in virions, and virus infectivity.

Spatial proximity of the HIV-1 nucleocapsid protein zinc fingers investigated by time-resolved fluorescence and fluorescence resonance energy transfer.

The three-dimensional structure of peptides encompassing the two zinc-saturated finger motifs of the nucleocapsid protein NCp7 of HIV-1 has been reported by several groups. Whereas the folded structures of the finger motifs were in good agreement, discrepancies existed concerning their spatial relationship since the fingers were found either close to each other [Morellet, N., Jullian, N., De Rocquigny, H., Maigret, B., Darlix, J. L., & Roques, B. P. (1992) Embo J. 11, 3059-3065] or independently folded [Omichinski, J. G., Clore, G. M., Sakaguchi, K., Appella, E., & Gronenborn, A. M. (1991) FEBS Lett. 292, 25-30, Summers, M. F., Henderson, L. E., Chance, M. R., Bess, J. W., Jr., South, T. L., Blake, P. R., Sagi, I., Perez-Alvarado, G., Sowder, R.C., III, Hare, D.R., & Arthur, L. O. (1992) Protein Sci. 1, 563-574]. As in the interacting finger model, Phe16 in the NH2-terminal finger and Trp37 in the COOH-terminal finger were found to be spatially close, the fluorescence properties of the aromatic residues at positions 16 and 37 in the wild-type and two conservatively substituted (12-53) NCp7 peptides were investigated and compared with those of three negative control derivatives where the finger motifs were not in close contact. Direct distance measurements by Tyr-Trp fluorescence resonance energy transfer of the former derivatives yielded a 7-12 A interchromophore distance range which is clearly inconsistent with the 12.5-18 A range measured for the negative controls and thus a random orientation of the zinc finger motifs.(ABSTRACT TRUNCATED AT 250 WORDS)