Cross-Sectional Associations between Body Size,Circulating Sex-Steroid Hormones and IGF Components among Healthy Chinese Women

The incidence of breast cancer has increased in Asian countries and rates of hormone receptor (HR) negative breast cancer exceed those of Western countries. Epidemiologic data suggest that the association between body size and BC risk may vary by HR status, and could differ geographically. While body size may influence BC risk by moderating the synthesis and metabolism of circulating sex-steroid hormones, insulin-like growth factor (IGF)-1 and related binding proteins, there is a dearth of literature among Asian women. We aimed to examine these specific associations in a sample of Chinese women. In Sichuan Province 143 women aged ≥40 years were recruited through outpatient services (2011–2012). Questionnaires, anthropometric measurements, and blood samples were utilized for data collection and linear regression was applied in data analyses. Among women <50 years we observed a non-monotonic positive association between body mass index (BMI) and 17β-estradiol, and a reversed J-shaped association between BMI and IGF-1 (p ≤0.05). We observed similar associations between waist-to-hip ratio and these markers. Our finding of augmented IGF-1 among women with low body mass may have implications for understanding breast tumor heterogeneity in diverse populations and should be evaluated in larger prospective studies with cancer outcomes.     

Lamellar packing of a chiral N,N-dimethylphosphatidylethanolamine: electron diffraction. Evidence for a lecithin-type headgroup conformation

Lamellar electron diffraction intensity data from epitaxially crystallized 1,2-dipalmitoyl-sn-glycerophospho-N,N-dimethylethanolamine were used to determine the layer packing in order to compare the chiral structure to the crystal structure of a racemic homologue. After finding the chain orientation, the structure was determined by interpretation of the Patterson function, followed by independent crystallographic phase assignments with conventional direct methods (use of three phase structure invariants). The phase determination was verified by a translational search with a molecular model based on a similar lecithin structure. The final R-value is 0.29, and this is lowered to 0.18 after a correction is made for incoherent multiple electron scattering. The layer packing is found to be very much like that of a diacyl phosphatidylcholine with the N,N-dimethylethanolamine moiety parallel to the bilayer surface rather than the perpendicular arrangement of headgroups involved in an interdigitated layer, as seen for racemic homolog.     

Phosphorylation and ubiquitination of dynamin-related proteins (AtDRP3A/3B) synergically regulate mitochondrial proliferation during mitosis

The balance between mitochondrial fission and fusion is disrupted during mitosis, but the mechanism governing this phenomenon in plant cells remains enigmatic. Here, we used mitochondrial matrix‐localized Kaede protein (mt‐Kaede) to analyze the dynamics of mitochondrial fission in BY‐2 suspension cells. Analysis of the photoactivatable fluorescence of mt‐Kaede suggested that the fission process is dominant during mitosis. This finding was confirmed by an electron microscopic analysis of the size distribution of mitochondria in BY‐2 suspension cells at various stages. Cellular proteins interacting with Myc‐tagged dynamin‐related protein 3A/3B (AtDRP3A and AtDRP3B) were immunoprecipitated with anti‐Myc antibody‐conjugated beads and subsequently identified by microcapillary liquid chromatography–quadrupole time‐of‐flight mass spectrometry (CapLC Q‐TOF) MS/MS. The identified proteins were broadly associated with cytoskeletal (microtubular), phosphorylation, or ubiquitination functions. Mitotic phosphorylation of AtDRP3A/AtDRP3B and mitochondrial fission at metaphase were inhibited by treatment of the cells with a CdkB/cyclin B inhibitor or a serine/threonine protein kinase inhibitor. The fate of AtDRP3A/3B during the cell cycle was followed by time‐lapse imaging of the fluorescence of Dendra2‐tagged AtDRP3A/3B after green‐to‐red photoconversion; this experiment showed that AtDRP3A/3B is partially degraded during interphase. Additionally, we found that microtubules are involved in mitochondrial fission during mitosis, and that mitochondria movement to daughter cell was limited as early as metaphase. Taken together, these findings suggest that mitotic phosphorylation of AtDRP3A/3B promotes mitochondrial fission during plant cell mitosis, and that AtDRP3A/3B is partially degraded at interphase, providing mechanistic insight into the mitochondrial morphological changes associated with cell‐cycle transitions in BY‐2 suspension cells.     

Engineering Hybrid Guided Modes in Subwavelength Uniaxial Metamaterial Waveguides

We report anomalous dispersion properties of hybrid guided modes (HGMs) and their group velocity in a subwavelength uniaxial metamaterial waveguide with metal cladding. We derive exact dispersion relations and modal fields of HGMs by solving eigenvalue equation based on basic electromagnetic field theory in detail. Numerical results show that two fundamental HGMs and two types of high-order HGMs can be excited, and their exciting conditions are clarified. In addition, such HGMs can be engineered to belong to normal dispersion or anomalous dispersion. Importantly, the HGMs may be controlled to be forward or backward, and their group velocities may be very small in a certain frequency band. These properties make such metamaterial waveguides have many potential applications in integrated optics, information storage and biosensing.     

Identification two novel nacrein-like proteins involved in the shell formation of the Pacific oyster Crassostrea gigas

Nacrein-like proteins have carbonic anhydrase (CA)-like domains, but their coding regions are flanked by inserted repeat sequence, such as Gly-X-Asn. Reportedly, nacrein-like proteins show the highest similarity to human carbonic anhydrase 1(α-CA1), possess CA catalytic functions, and play a key role in shell biomineralization. In the present study, two novel nacrein-like proteins were firstly identified from the shell-forming mantle of the Pacific oyster Crassostrea gigas. With numerous analyses, it was identified and characterized that both the nacrein-like proteins F1 and F2 were secreted and most closely related to the nacrein-like protein of California mussel Mytilus californianus via phylogenetic analysis. RT-PCR analysis showed that the nacrein-like proteins F1 and F2 were expressed in multiple tissues and the expression levels remarkably rose after entering the spat stage, which were basically consistent with the increase of calcite fractions in the total shell volume. Surprisingly, the Gly-X-Asn repeat domain, which is distinctive in most nacrein-like proteins, was absent in the two newly identified nacrein-like proteins in C. gigas and replaced with a series of acidic amino acids (D/E). Regardless, nacrein-like proteins in mollusks seem to be vital to the deposition of calcium carbonate and likely perform diverse functions.