Interfacial ferromagnetism and exchange bias in CaRuO3/CaMnO3 superlattices

We have found ferromagnetism in epitaxially grown superlattices of CaRuO(3)/CaMnO(3) that arises in one unit cell at the interface. Scanning transmission electron microscopy and electron energy loss spectroscopy indicate that the difference in magnitude of the Mn valence states between the center of the CaMnO(3) layer and the interface region is consistent with double exchange interaction among the Mn ions at the interface. Polarized neutron reflectivity and the CaMnO(3) thickness dependence of the exchange bias field together indicate that the interfacial ferromagnetism is only limited to one unit cell of CaMnO(3) at each interface. The interfacial moment alternates between the 1 μ(B)/interface Mn ion for even CaMnO(3) layers and the 0.5 μ(B)/interface Mn ion for odd CaMnO(3) layers. This modulation, combined with the exchange bias, suggests the presence of a modulating interlayer coupling between neighboring ferromagnetic interfaces via the antiferromagnetic CaMnO(3) layers.

Expression of putative stem marker nestin and CD133 in advanced serous ovarian cancer

It is hypothesized that "cancer stem cells" are responsible for the resistance to chemotherapy of cancer cells in ovarian cancers. The objective of the studies was to explore if the stem cell biomarkers could be used to predict the tumor chemotherapy-resistance in serous ovarian cancer patients. Expression of two putative stem cell markers CD133 and nestin, and vascular epithelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) were detected in 123 cases of advanced serous ovarian cancer specimens by immunohistochemistry. To estimate intra-tumoral microvessel density (MVD), CD34 immunostaining was also performed. CD133 and nestin were defined to be positive in 35.0% and 32.5% of the serous ovarian carcinoma tissues, respectively. It was observed that overexpression of nestin but not CD133 was associated with the cisplatin-based chemotherapy resistance and shorter overall survival of the patients, and nestin was found to be an independent prognostic factor. Moreover, positive nestin expression also correlated to increased expression of EGFR and VEGF, and elevated MVD in tumors. The results of this study suggest that serous ovarian cancers with high expression level of nestin represent an aggressive malignant phenotype associated with poor prognosis, and treatment targeted the nestin positive cancer cells might be a promising therapeutic strategy for this subgroups.

The polymorphisms in the VHL and HIF1A genes are associated with the prognosis but not the development of renal cell carcinoma

BACKGROUND

The von Hippel-Lindau (VHL) tumor suppressor gene and hypoxia-inducible factor-1α (HIF1A) play a pivotal role in renal carcinogenesis. This study was aimed to clarify the influence of VHL and HIF1A polymorphisms on renal cell cancer (RCC) susceptibility and survival.

SUBJECTS AND METHODS

We genotyped four potentially functional single-nucleotide polymorphisms (rs779805 in VHL and rs11549465, rs11549467, and rs2057482 in HIF1A) and assessed their associations with RCC risk, clinicopathologic parameters in a case-control study of 620 patients and 623 controls, and the prognosis of RCC in a cohort of 311 patients.

RESULTS

No significant differences in VHL or HIF1A genotypes were observed between RCC cases and controls. However, individuals with ≥2 variant alleles of the four polymorphisms were associated with less frequent lymph node metastasis and lower clinical stage (P = 0.032 and P = 0.041, respectively). And the number of variant alleles was associated with improved survival in a dose-response manner (P(trend) = 0.013). Furthermore, multivariate Cox regression analysis showed that the number of variant alleles (≥1 versus 0) was an independent prognostic factor for RCC survival (P = 0.036) together with clinical stage and tumor grade.

CONCLUSION

The VHL and HIF1A polymorphisms may not influence RCC susceptibility but may jointly influence RCC progression and survival.

Circular dichroism in biological photonic crystals and cubic chiral nets

Nature provides impressive examples of chiral photonic crystals, with the notable example of the cubic so-called srs network (the label for the chiral degree-three network modeled on SrSi2) or gyroid structure realized in wing scales of several butterfly species. By a circular polarization analysis of the band structure of such networks, we demonstrate strong circular dichroism effects: The butterfly srs microstructure, of cubic I4(1)32 symmetry, shows significant circular dichroism for blue to ultraviolet light, that warrants a search for biological receptors sensitive to circular polarization. A derived synthetic structure based on four like-handed silicon srs nets exhibits a large circular polarization stop band of a width exceeding 30%. These findings offer design principles for chiral photonic devices.

Interplay of cAMP and MAPK pathways in hCG secretion and fusogenic gene expression in a trophoblast cell line

Differentiation of human placental mononuclear trophoblasts into a multinucleate syncytium involves up-regulation of key proteins promoting cell fusion and increased capacity for placental hormonogenesis. It is well established that the activation of adenylyl cyclase leads to increased expression of trophoblast fusogenic gene machinery and human chorionic gonadotropin (hCG) secretion. We used the forskolin-induced syncytialisation of BeWo choriocarcinoma cells as a model to characterise in detail the signalling pathway downstream of adenylyl cyclase. Forskolin treatment induced a rapid and potent ERK1/2 and p38MAPK phosphorylation; this cascade required PKA-AKAP interactions and led to downstream CREB-1/ATF-1 phosphorylation via ERK1/2-dependent but p38MAPK-independent mechanisms. Interestingly both p38MAPK and ERK1/2 were involved in forskolin-induced hCG-secretion, suggesting the presence of additional p38MAPK-dependent but CREB-1/ATF-1-independent pathways. Forskolin treatment of BeWo cells significantly up-regulated the expression of various fusogenic gene mRNAs, including syncytin-1 and -2 (by 3- and 10-fold, respectively) the transcription factors old astrocyte specifically induced substance (OASIS) and glial cells missing a (GCMa) (by 3- and 6-fold, respectively) and the syncytin-2 receptor, major facilitator superfamily domain containing 2 (MFSD2) (by 2-fold). Up-regulation of AKAP79 and AKAP250 (by 2.5- and 4-fold, respectively) was also identified in forskolin-treated BeWo cells. Forskolin effects on all these genes were suppressed by chemical inhibition of p38MAPK whereas only specific genes were sensitive to ERK1/2 inhibition. This data provide novel insights into the signalling molecules and mechanisms regulating fusogenic gene expression by the adenylyl cyclase pathway.

Calculation of the Johann error for spherically bent x-ray imaging crystal spectrometers

New x-ray imaging crystal spectrometers, currently operating on Alcator C-Mod, NSTX, EAST, and KSTAR, record spectral lines of highly charged ions, such as Ar(16+), from multiple sightlines to obtain profiles of ion temperature and of toroidal plasma rotation velocity from Doppler measurements. In the present work, we describe a new data analysis routine, which accounts for the specific geometry of the sightlines of a curved-crystal spectrometer and includes corrections for the Johann error to facilitate the tomographic inversion. Such corrections are important to distinguish velocity induced Doppler shifts from instrumental line shifts caused by the Johann error. The importance of this correction is demonstrated using data from Alcator C-Mod.

Laryngeal epithelial thickness: a comparison between optical coherence tomography and histology

OBJECTIVES

Optical coherence tomography, an imaging modality using near-infrared light, produces cross-sectional tissue images with a lateral pixel resolution of 10 microm. However, normative data is first needed on epithelial thickness for lesion characterisation, and, to date, little exists. The purpose of our study is to measure normal laryngeal epithelial thickness by in vivo optical coherence tomography, and compare these values to those obtained from fixed ex-vivo laryngectomy specimens.

DESIGN AND SETTING

Prospective at a single medical center in California, United States.

PARTICIPANTS

A total of 116 patients undergoing operative endoscopy.

MAIN OUTCOME MEASURES

Optical coherence tomography images of clinically normal laryngeal subsites were selected. Calibrated measurements of epithelial thickness at various laryngeal subsites were recorded. Measurements of epithelial thickness from corresponding areas were obtained using optical micrometry on histologically normal regions of 15 total laryngectomy specimens. Descriptive statistics were performed.

RESULTS

Mean epithelial optical coherence tomography thicknesses were: true vocal cords (81 microm), false vocal cords (78 microm), subglottis (61 microm), aryepiglottic folds (111 microm), laryngeal epiglottis (116 microm) and lingual epiglottis (170 microm). Epithelial thicknesses in fixed tissues were: true vocal cords (103 microm), false vocal cords (79 microm), aryepiglottic folds (205 microm) subglottis (61 microm), laryngeal epiglottis (38 microm) and lingual epiglottis (130 microm).

CONCLUSIONS

Optical coherence tomography does not have the artifacts associated with conventional histologic techniques. The inevitable development of office-based optical coherence tomography devices will increase the precision of laryngeal measurements and contribute to the clinical application of this technology in diagnosing laryngeal disease.

Placental expression of 2,3 bisphosphoglycerate mutase in IGF-II knock out mouse: correlation of circulating maternal 2,3 bisphosphoglycerate and fetal growth

Bisphosphoglycerate mutase (BPGM) catalyses the formation of 2,3 bisphosphoglycerate (BPG) a ligand of haemoglobin. BPG facilitates liberation of oxygen from haemoglobin at low oxygen tension enabling efficient delivery of oxygen to tissues. We describe expression of BPGM in mouse labyrinthine trophoblasts, located at the maternal-placental interface. Expression is lower in placentae of igf2(+/-) knockout mice, a widely used model of growth restriction, compared to wild type placentae. Circulating maternal BPG increased throughout gestation but this increase was less in wt mothers carrying igf2(+/-) pups than in those carrying exclusively wt pups. This reduction was observed well before term and may contribute to the low birth weight of igf2(+/-) pups. Strikingly, we also measured reductions of fetal and placental weight in wt littermates of igf2(+/-) pups compared to pups developing in an exclusively wt environment. These data suggest that placental expression of BPGM can influence maternal BPG concentrations and supports a hypothesis under which BPG synthesized in the placenta may act on maternal haemoglobin to enhance delivery of oxygen to the developing fetus.

Physiological and biochemical responses of in vitro Fusarium oxysporum f.sp. niveum to benzoic acid

The allelopathic potential of an artificially applied allelochemical, benzoic acid, on in vitro Fusarium oxysporum f.sp. niveum (a soil-borne pathogen causing watermelon wilt) was evaluated. Benzoic acid strongly inhibited its growth, sporulation and conidia germination, whereas it stimulated virulence factors of this pathogen. The biomass was reduced by 83-96 % and the conidia germinating rate and conidia production rate were decreased by 100 % at a concentration of >200 mg/L. However, phytopathogenic enzyme activities and mycotoxin production were stimulated with an increase of 10.2-1250 % for enzyme activities and 610-2630 % for mycotoxin yield.

One-step purification of 3,4-dihydroxyphenyllactic acid, salvianolic acid B, and protocatechualdehyde from Salvia miltiorrhiza Bunge by isocratic stepwise hydrogen bond adsorption chromatography on cross-linked 12% agarose

Three major active components of the traditional Chinese medicinal herb Salvia miltiorrhiza Bunge, 3,4-dihydroxyphenyllactic acid, salvianolic acid B, and protocatechualdehyde, are separated and purified from a crude water extract in one step by isocratic hydrogen bond adsorption chromatography on cross-linked 12% agarose (Superose 12 HR 10/30). Separation is achieved by stepwise elution with mobile phases composed of mixtures of ethanol and acetic acid: 0-50 mL, 5% ethanol, 5% acetic acid; 50-100 mL, 20% ethanol, 20% acetic acid; and 100-200 mL, 30% ethanol, 30% acetic acid. The 3,4-dihydroxyphenyllactic acid is obtained with a purity of 97.3% and with a recovery of 88.1%. The corresponding figures for protocatechualdehyde are a purity of 99.4% with a recovery of 90.7%, and for salvianolic acid B a purity of 90.4% with a recovery of 50.3%, respectively. At a sample load of 40 mg crude extract dissolved in 0.5 mL mobile phase (corresponding to a load of 1.6 mg/mL gel), a 3,4-dihydroxyphenyllactic acid purity of approximately 94% with a recovery of 80.2% is obtained.

Peak effect in the critical current of type II superconductors with strong magnetic vortex pinning

We perform 2D Langevin simulations studying the peak effect (PE) of the critical current taking into account the temperature dependence of the competing forces. We observe and report that the PE results from the competition of vortex-vortex interactions and vortex-pin interactions which have different temperature dependencies. The simulations reveal that the PE can take place only for certain pinning strengths, densities of pinning centers, and driving forces, which is in good agreement with experiments. No apparent vortex order-disorder transition is observed across the PE regime. In addition, the PE is a dynamical phenomenon, and thermal fluctuations can speed up the process for the formation of the PE.

Expression of Rap1GAP in human myeloid disease following microarray selection

To find the underlying causes of primary myelodysplastic syndrome (MDS), the gene expression profiling of both CD34+ cells and bone marrow mononuclear cells from MDS patients was performed using oligonucleotide microarray and cDNA microarrays, respectively. Several candidate genes which were differentially expressed in MDS patients versus normal controls were selected and confirmed in expanding samples by quantitative real-time reverse transcription-polymerase chain reaction after clustering and bioinformatics analysis. one of these genes, RAP1GAP, was found to be expressed at a significantly higher level in patients with MDS in comparison with those suffering from other hematopoietic diseases including leukemia (P < 0.01). We propose that over-expression of RAP1GAP gene may play a role in the pathogenesis of MDS.

Optical deflection and sorting of microparticles in a near-field optical geometry

Near-field optical micromanipulation permits new possibilities for controlled motion of trapped objects. In this work, we report an original geometry for optically deflecting and sorting micro-objects employing a total internal reflection microscope system. A small beam of laser light is delivered off-axis through a total internal reflection objective which creates an elongated evanescent illumination of light at a glass/water interface. Asymmetrical gradient and scattering forces from this light field are seen to deflect and sort polystyrene microparticles within a fluid flow. The speed of the deflected objects is dependent upon their intrinsic properties. We present a finite element method to calculate the optical forces for the evanescent waves. The numerical simulations are in good qualitative agreement with the experimental observations and elucidate features of the particle trajectory. In the size range of 1 microm to 5 microm in diameter, polystyrene spheres were found to be guided on average 2.9 +/- 0.7 faster than silica spheres. The velocity increased by 3.0 +/- 0.5 microms(-1) per microm increase in diameter for polystyrene spheres and 0.7 +/- 0.2 microms(-1) per microm for silica. We employ this size dependence for performing passive optical sorting within a microfluidic chip and is demonstrated in the accompanying video.

Protective effects of sirolimus by attenuating connective tissue growth factor expression in human chronic allograft nephropathy

BACKGROUND

Chronic allograft nephropathy (CAN) remains a great challenge for the transplant clinician. The introduction of sirolimus (RAPA) with cyclosporine (CsA) reduction maybe shed new light to improve graft survival. The aim of this study was to investigate the overall effects of sirolimus conversion on biopsy-proven CAN.

METHODS

One hundred and ten renal transplant recipients with biopsy-proven CAN were randomized into two groups: 54 for CsA reduction and 56 for sirolimus conversion treatment. After 24-month follow-up, the outcome variables included graft function and survival as well as CAN Banff grading and intrarenal expression of connective tissue growth factor (CTGF) via repeated biopsy.

RESULTS

Graft function and survival rate were significantly better in the RAPA group. CAN grading worsened in the CsA group, whereas they were stable in the RAPA group. There was weak expression in the RAPA group but significant, increased expression of CTGF in glomeruli and interstitial area in the CSA group (P < .01) both by immunohistochemical staining or real-time polymerase chain reaction detection.

CONCLUSION

Sirolimus conversion provided a beneficial strategy to improve long-term graft survival in CAN. Attenuation of renal CTGF expression may be one of its antifibrotic and antiproliferation effects.

Fibre-optic nonlinear optical microscopy and endoscopy

Nonlinear optical microscopy has been an indispensable laboratory tool of high-resolution imaging in thick tissue and live animals. Rapid developments of fibre-optic components in terms of growing functionality and decreasing size provide enormous opportunities for innovations in nonlinear optical microscopy. Fibre-based nonlinear optical endoscopy is the sole instrumentation to permit the cellular imaging within hollow tissue tracts or solid organs that are inaccessible to a conventional optical microscope. This article reviews the current development of fibre-optic nonlinear optical microscopy and endoscopy, which includes crucial technologies for miniaturized nonlinear optical microscopy and their embodiments of endoscopic systems. A particular attention is given to several classes of photonic crystal fibres that have been applied to nonlinear optical microscopy due to their unique properties for ultrashort pulse delivery and signal collection. Furthermore, fibre-optic nonlinear optical imaging systems can be classified into portable microscopes suitable for imaging behaving animals, rigid endoscopes that allow for deep tissue imaging with minimally invasive manners, and flexible endoscopes enabling imaging of internal organs. Fibre-optic nonlinear optical endoscopy is coming of age and a paradigm shift leading to optical microscope tools for early cancer detection and minimally invasive surgery.