bluuebunny/crossref_metadata_2025 huggingface dataset:
Sequential Barium‐Catalysed N−H/H−Si Dehydrogenative Cross‐Couplings: Cyclodisilazanes versus Linear Oligosilazanes
Authors: Bellini Clément , Roisnel Thierry , Carpentier Jean‐François , Tobisch Sven , Sarazin Yann
Published: September 2016

Starting from Ph3SiH, the barium precatalyst Ba[CH(SiMe3)2]2⋅(THF)3was used to produce the disilazane Ph3SiN(Bn)SiPh2NHBn (4) by sequential N−H/H−Si dehydrogenative couplings with BnNH2and Ph2SiH2. Substrate scope was extended to other amines and hydrosilanes. This smooth protocol gives quantitative yields and full chemoselectivity. Compound4and the intermediates Ph3SiNHBn and Ph3SiN(Bn)SiHPh2were structurally characterised. Further attempts at chain extension by dehydrocoupling of Ph2SiH2with4instead resulted in cyclisation of this compound, forming the cyclodisilazanec‐(Ph2Si‐NBn)2(5) which was crystallographically authenticated. The ring‐closure mechanism leading to5upon release of C6H6was determined by complementary experimental and theoretical (DFT) investigations. Ba[CH(SiMe3)2]2⋅(THF)3and4react to afford the reactive Ba{N(Bn)SiPh2N(Bn)SiPh3}2, which was characterised in situ by NMR spectroscopy. Next, in a stepwise process, intramolecular nucleophilic attack of the metal‐bound amide on the terminal silicon atom generates a five‐coordinate silicate. It is followed by turnover‐limiting β‐C6H5transfer to barium; this releases5and forms a transient [Ba]−Ph species, which undergoes aminolysis to regenerate [Ba]−N(Bn)SiPh2N(Bn)SiPh3. DFT computations reveal that the irreversible production of5through such a stepwise ring‐closure mechanism is much more kinetically facile (ΔG≠=26.2 kcal mol−1) than an alternative σ‐metathesis pathway (ΔG≠=48.2 kcal mol−1).
Activation of Aromatic C−C Bonds of 2,2’‐Bipyridine Ligands
Authors: Fombona Sergio , Espinal‐Viguri Maialen , Huertos Miguel A. , Díaz Jesús , López Ramón , Menéndez M. Isabel , Pérez Julio , Riera Lucía
Published: September 2016

4,4’‐Disubstituted‐2,2′‐bipyridine ligands coordinated to MoII and ReI cationic fragments become dearomatized by an intramolecular nucleophilic attack from a deprotonated N‐alkylimidazole ligand in cis disposition. The subsequent protonation of these neutral complexes takes place on a pyridine carbon atom rather than at nitrogen, weakening an aromatic C−C bond and affording a dihydropyridyl moiety. Computational calculations allowed for the rationalization of the formation of the experimentally obtained products over other plausible alternatives.
Towards Enzyme‐like, Sustainable Catalysis: Switchable, Highly Efficient Asymmetric Synthesis of Enantiopure Biginelli Dihydropyrimidinones or Hexahydropyrimidinones
Authors: Lillo V. J. , Saá J. M.
Published: September 2016

Organocatalysts displaying a network of cooperative hydrogen bonds (NCHB) have been employed in an enzyme‐like manner for a direct, switchable synthesis of enantiopure hexahydropyrimidinones (HHPMs) or dihydropyrimidinones (DHPMs), which starts at a common, easily accessible α‐ureidosulfone stage. The NCHB organocatalyst exploits all its potential as a pure hydrogen‐bond biomimetic catalyst even in the presence of organic bases. This one‐pot, diastereo‐ and enantioselective synthetic procedure has been proven to be robust, scalable, highly efficient, and environmentally benign. A straightforward and truly practical entry to enantiopure HHPMs is reported for the first time.
Functional Group Interconversion: Decarbonylative Borylation of Esters for the Synthesis of Organoboronates
Authors: Guo Lin , Rueping Magnus
Published: September 2016

A new and efficient nickel‐catalyzed decarbonylative borylation reaction of carboxylic acid esters with bis(pinacolato)‐diboron has been developed. This transformation allows access to structurally diverse aryl as well as alkenyl and alkyl boronate esters with high reactivity, broad substrate scope, and excellent functional‐group tolerance. Further experiments show that this protocol can be carried out on a gram scale and applied to orthogonal synthetic strategies.
Fine needle aspiration cytology of IgG4‐related disease: A potential diagnostic pitfall?
Authors: Kaur Rajwant , Mitra Suvradeep , Rajwanshi Arvind , Das Ashim , Nahar Saikia Uma , Dey Pranab
Published: September 2016

Background

IgG4‐related disease (IgG4‐RD) is a tumefactive fibro‐inflammatory lesion that can affect any organ system in the body. Till date, no cytological data on IgG4‐RD are available and this is the first study depicting the cytopathology features of IgG4‐RD.

Aim and Objective

To describe the cytopathological features and potential diagnostic errors of IgG4‐RD.

Materials and Methods

The cytological features of 10 histopathology proven IgG4‐RD cases (11 samples) were retrospectively reviewed along with corresponding histopathology.

Results

The cellularity of the cytology smears was low (36.4%) to moderate (45.4%) to high (18.1%). The low cellularity correlated well with the pattern C in histopathology (predominant fibrosis pattern). The non‐epithelial background showed a preponderance of lymphocytes along with polymorphs and spindle‐shaped fibroblasts. Most of these cases showed the presence of plasma cells and eosinophils. Epithelial atypia was seen in 18.2% cases.

Conclusion

The causes of misdiagnosis were low cellularity, epithelial atypia, and non‐representative background. The important diagnostic clues to suspect a diagnosis of IgG4‐RD include low cellularity despite adequate effort, inflammatory background rich in lymphocytes and spindle cells admixed with a few plasma cells and eosinophils along with radiological features and raised serum IgG4 Diagn. Cytopathol. 2017;45:14–21. © 2016 Wiley Periodicals, Inc.
Nadolol reduces insulin sensitivity in liver cirrhosis: a randomized double‐blind crossover trial
Authors: Lee Wai Gin , Murphy Rinki , McCall John L. , Gane Edward J. , Soop Mattias , Tura Andrea , Plank Lindsay D.
Published: September 2016

Background

Liver cirrhosis is frequently complicated by portal hypertension leading to increased mortality from variceal bleeding and hepatic decompensation. Noncardioselective β‐blockers not only reduce portal hypertension and prevent variceal bleeding in cirrhosis but also impair glucose tolerance and insulin sensitivity in other settings. This study aimed to determine whether nonselective β‐blockade with nadolol impairs glucose metabolism in liver cirrhosis.

Methods

A randomized, double‐blind, placebo‐controlled crossover trial of nadolol in cirrhotic patients examined insulin sensitivity, disposition index, and glucose tolerance. Stable cirrhotic patients of mixed etiology underwent an intravenous glucose tolerance test and hyperinsulinemic‐euglycemic clamp for the measurement of insulin secretion and insulin sensitivity (n = 16) and a 75‐g oral glucose tolerance test (n = 17). These measurements were conducted twice (after 3 months of treatment with nadolol or placebo and, after a 1‐month washout period, after 3 months on the alternative treatment). Total body fat and plasma catecholamines were measured at the end of each 3‐month treatment.

Results

Compared with placebo, nadolol treatment reduced insulin sensitivity (79.7 ± 10.1 vs 99.6 ± 10.3 μL/kg fat‐free mass·min−1·(mU/L)−1, P = .005). Insulin secretion was unchanged (P = .24), yielding a lower disposition index with nadolol (6083 ± 2007 vs 8692 ± 2036, P = .050). There was no change in total body fat or plasma catecholamines. A 2‐hour plasma glucose concentration from the oral glucose tolerance test was higher on nadolol than placebo (10.8 ± 0.9 vs 9.9 ± 0.9 mmol/L, P = .035).

Conclusions

Nadolol significantly worsened insulin sensitivity, glycemia, and disposition index in patients with liver cirrhosis. These findings may have significant clinical implications because cirrhosis is already associated with an increased prevalence of diabetes.
Why do larger mothers produce larger offspring? A test of classic theory
Authors: Cameron Hayley , Monro Keyne , Malerba Martino , Munch Stephan , Marshall Dustin
Published: September 2016

Across a wide range of taxa, larger mothers produce larger offspring. Theory assumes that larger, more fecund mothers create higher local densities of siblings, and so larger mothers produce larger offspring to offset sibling competition. This assumption has been debated for over 30 yr, but direct empirical tests are surprisingly rare. Here, we test two key assumptions of classic theories that predict sibling competition drives maternal‐size–offspring‐size (MSOS) correlations: (1) independent effects of offspring size and sibling density on offspring performance or (2) as a product of an interaction between these two factors. To simultaneously test these alternative assumptions, we manipulate offspring size and sibling density in the marine invertebrate, Bugula neritina, and monitor offspring performance in the field. We found that depending on the fitness metric being considered, offspring size and sibling density can either independently or interactively affect offspring performance. Yet sibling density did not affect offspring performance in the ways that classic theories assume. Given our results, it is unlikely that sibling competition drives the positive MSOS correlation observed in this species. Empirical support for these classic theories remains lacking, suggesting alternative explanations are necessary.
Synthesis of Tetrasubstituted Pyrazoles from Substituted Hydrazines and β‐Keto Esters
Authors: Bakanas Ian J. , Moura‐Letts Gustavo
Published: September 2016

Herein we report the synthesis of tetrasubstituted pyrazoles from simple hydrazines and β‐keto esters under mild, basic conditions. This reaction enables the selective synthesis of pyrazolones, alkoxypyrazoles, and tetrasubstituted pyrazoles for a large variety of aromatic hydrazines and substituted β‐keto esters with high yields and selectivities. This method permits access to highly complex pyrazole scaffolds with four orthogonal diversification groups.
A porous medium‐chain‐length poly(3‐hydroxyalkanoates)/hydroxyapatite composite as scaffold for bone tissue engineering
Authors: Ansari Nor Faezah , Annuar M. Suffian M. , Murphy Belinda Pingguan
Published: September 2016

Polyhydroxyalkanoates (PHA) are hydrophobic biopolymers with huge potential for biomedical applications due to their biocompatibility, excellent mechanical properties and biodegradability. A porous composite scaffold made of medium‐chain‐length poly(3‐hydroxyalkanoates) (mcl‐PHA) and hydroxyapatite (HA) was fabricated using particulate leaching technique and NaCl as a porogen. Different percentages of HA loading was investigated that would support the growth of osteoblast cells. Ultrasonic irradiation was applied to facilitate the dispersion of HA particles into the mcl‐PHA matrix. The different P(3HO‐co‐3HHX)/HA composites were investigated using field emission scanning electron microscopy (FESEM), X‐ray diffraction (XRD) and energy dispersive X‐ray analysis (EDXA). The scaffolds were found to be highly porous with interconnecting pore structures and the HA particles were homogeneously dispersed in the polymer matrix. The scaffolds biocompatibility and osteoconductivity were also assessed following the proliferation and differentiation of osteoblast cells on the scaffolds. From the results, it is clear that scaffolds made from P(3HO‐co‐3HHX)/HA composites are viable candidate materials for bone tissue engineering applications.
Screening, statistical optimized production, and application of β‐mannanase from some newly isolated fungi
Authors: Soni Hemant , Rawat Hemant Kumar , Ahirwar Saroj , Kango Naveen
Published: September 2016

Eighty‐eight fungi isolated from soil and decaying organic matter were screened for mannanolytic activity. Twenty‐eight fungi produced extracellular mannanase on locust bean gum as evidenced by zone of hydrolysis produced on mannan agar gel. Six prominent producers, including four Fusarium species namely Fusarium fusarioides NFCCI 3282, Fusarium solani NFCCI 3283, Fusarium equiseti NFCCI 3284, Fusarium moniliforme NFCCI 3287 with Cladosporium cladosporioides NFCCI 3285 and Acrophialophora levis NFCCI 3286 produced the β‐mannanase in the range of 84–140 nkat/mL. All these grew well on particulate substrates in solid‐state fermentation (SSF), producing relatively higher titers on mannan‐rich palm kernel cake (PKC) and copra meal. Two high yielding strains, F. equiseti (1747 nkat/gds) and A. levis (897 nkat/gds) were selected for statistical optimization of mannanase on PKC. Interaction of two critical solid state fermentation parameters, pH and moisture on mannanase production by these two molds was studied by response surface method. Optimized production on PKC resulted in three‐ to fourfold enhancement in enzyme yield was observed in case of F. equiseti (5945 nkat/gds) and A. levis (4726 nkat/gds). HPLC analysis of mannan hydrolysate indicated that F. equiseti and A. levis mannanase performed efficient hydrolysis of konjac gum (up to 99%) with exclusive mannooligosaccahride (DP of 4) production. A seminative SDS‐PAGE revealed that A. levis and F. solani produced three isoforms, F. moniliforme produced two isoforms while F. fusarioides, F. equiseti, and C. cladosporioides produced a single enzyme.
Chlorpyrifos exposure affects fgf8, sox9, and bmp4 expression required for cranial neural crest morphogenesis and chondrogenesis in Xenopus laevis embryos
Authors: Tussellino Margherita , Ronca Raffaele , Carotenuto Rosa , Pallotta Maria M. , Furia Maria , Capriglione Teresa
Published: September 2016

Chlorpyrifos (CPF) is an organophosphate insecticide used primarily to control foliage and soil‐borne insect pests on a variety of food and feed crops. In mammals, maternal exposure to CPF has been reported to induce dose‐related abnormalities such as slower brain growth and cerebral cortex thinning. In lower vertebrates, for example, fish and amphibians, teratogenic activity of this compound is correlated with several anatomical alterations. Little is known about the effects of CPF on mRNA expression of genes involved in early development of the anatomical structures appearing abnormal in embryos. This study investigated the effects of exposure to different CPF concentrations (10, 15 and 20 mg/L) on Xenopus laevis embryos from stage 4/8 to stage 46. Some of the morphological changes we detected in CPF‐exposed embryos included cranial neural crest cell (NCC)‐derived structures. For this reason, we analyzed the expression of select genes involved in hindbrain patterning (egr2), cranial neural crest chondrogenesis, and craniofacial development (fgf8, bmp4, sox9, hoxa2 and hoxb2). We found that CPF exposure induced a reduction in transcription of all the genes involved in NCC‐dependent chondrogenesis, with largest reductions in fgf8 and sox9; whereas, in hindbrain, we did not find any alterations in egr2 expression. Changes in the expression of fgf8, bmp4, and sox9, which are master regulators of several developmental pathways, have important implications. If these changes are confirmed to belong to a general pattern of alterations in vertebrates prenatally exposed to OP, they might be useful to assess damage during vertebrate embryo development. Environ. Mol. Mutagen. 57:589–604, 2016. © 2016 Wiley Periodicals, Inc.
Degradation of silicon wafers at high temperatures for epitaxial deposition
Authors: Rachow Thomas , Reber Stefan , Janz Stefan , Knapp Marius , Milenkovic Nena
Published: September 2016

The material quality degradation of silicon wafers by metal impurities, various crystal defects as well as light and thermally induced mechanisms is very important for the solar cell performance and has been investigated by various groups. In this paper, the material degradation during epitaxial deposition at high temperatures above 1100°C will be discussed. Annealing experiments in hydrogen atmosphere are done with the laboratory rapid thermal chemical vapor deposition reactor to mimic the thermal process conditions for epitaxial growth of silicon from the gas phase. A general investigation of crystallographic and electronic properties of n‐ and p‐type silicon wafers has been done between 950°C and 1150°C. A detailed sensitivity analysis of process parameters like cooling ramp, peak temperature, duration, and ambient gasses has been conducted. The degradation mechanism by metal impurities has been investigated by using silicon wafers with different diffusion barriers. Besides effective minority carrier lifetime, measurements by quasi steady state photo conductance, etch pit density, Raman spectroscopy, X‐ray diffraction, and Fourier transform infrared spectroscopy measurements have been done. The presented results have been used to improve the deposition process of epitaxial thin‐film solar cells, the production of silicon foils with a thickness <80 μm, and the fabrication of epitaxial multi junction solar cells with silicon bottom cell.
Determining soil erosion rates on semi‐arid watersheds using radioisotope‐derived sedimentation chronology
Authors: Polyakov V. O. , Nichols M. N. , Nearing M. A.
Published: September 2016

This study investigates erosion dynamics of the past 90 years in three small semi‐arid watersheds with histories of grazing and vegetation change. Activity of 137Cs and excess 210Pb from 18 cores collected from sedimentation ponds were measured using a gamma spectrometer. The sediment was dated using a constant rate of supply (CRS) model. This study represents the first time that reservoir sediment accumulation rates determined from fallout isotopes have been verified by direct volumetric measurements of aggradation based on topographic surveys. Measured sedimentation in the ponds ranged between 1.9 and 2.3 cm y−1, representing average sediment delivery rates from the watersheds of between 0.6 and 2.0 t ha−1 y−1. These sediment delivery rates were in agreement with those established by other methods for similar catchments in the region. Past variations in sedimentation rates were identified and correlated with recorded history of anthropogenic disturbance. 137Cs and 210Pb methods are suitable for use in arid environments and can complement each other to increase reliability of erosion rate estimates. The abundance of stock ponds in southwestern USA presents an opportunity to quantify historic erosion and sediment transfer dynamics in areas that have not been well studied or instrumented. Published 2016. This article is a U.S. Government work and is in the public domain in the USA
Review of emerging contaminants in aquatic biota from Latin America: 2002–2016
Authors: Llorca Marta , Farré Marinella , Eljarrat Ethel , Díaz-Cruz Sílvia , Rodríguez-Mozaz Sara , Wunderlin Daniel , Barcelo Damià
Published: September 2016

Although it is known that emerging contaminants are widespread all over the globe, there is a gap of information about their distribution in some geographical areas, such as Latin America. The present bibliographic work reviews the available literature about the presence of organic emerging contaminants in Latin American freshwater and marine biota between 2002 and 2016 and includes 23 works from Argentina, Brazil, Chile, Colombia, Mexico, and Nicaragua. In particular, the present review provides an overview of the occurrence of continuously present contaminants such as pharmaceuticals, personal care products, and pyrethroid insecticides, as well as the new groups of persistent organic pollutants, the halogenated flame retardants and the perfluoroalkyl substances. A wide overview is provided, considering not only occurrence data but also effects and potential transfer through the food chain. Environ Toxicol Chem 2017;36:1716–1727. © 2016 SETAC
Long and irregular menstrual cycles, polycystic ovary syndrome, and ovarian cancer risk in a population‐based case‐control study
Authors: Harris H.R. , Titus L.J. , Cramer D.W. , Terry K.L.
Published: September 2016

Long and irregular menstrual cycles, a hallmark of polycystic ovary syndrome (PCOS), have been associated with higher androgen and lower sex hormone binding globulin levels and this altered hormonal environment may increase the risk of specific histologic subtypes of ovarian cancer. We investigated whether menstrual cycle characteristics and self‐reported PCOS were associated with ovarian cancer risk among 2,041 women with epithelial ovarian cancer and 2,100 controls in the New England Case‐Control Study (1992–2008). Menstrual cycle irregularity, menstrual cycle length, and PCOS were collected through in‐person interview. Unconditional logistic regression models were used to calculate odds ratios (OR) and 95% confidence intervals (95% CIs) for ovarian cancer risk overall, and polytomous logistic regression to evaluate whether risk differed between histologic subtypes. Overall, we observed no elevation in ovarian cancer risk for women who reported periods that were never regular or for those reporting a menstrual cycle length of >35 days with ORs of 0.87 (95% CI = 0.69–1.10) and 0.83 (95% CI = 0.44–1.54), respectively. We observed no overall association between self‐reported PCOS and ovarian cancer (OR = 0.97; 95% CI = 0.61–1.56). However, we observed significant differences in the association with menstrual cycle irregularity and risk of ovarian cancer subtypes (pheterogeneity = 0.03) as well as by BMI and OC use (pinteraction < 0.01). Most notable, menstrual cycle irregularity was associated with a decreased risk of high grade serous tumors but an increased risk of serous borderline tumors among women who had never used OCs and those who were overweight. Future research in a large collaborative consortium may help clarify these associations.
Estimation of heritability for nine common cancers using data from genome‐wide association studies in Chinese population
Authors: Dai Juncheng , Shen Wei , Wen Wanqing , Chang Jiang , Wang Tongmin , Chen Haitao , Jin Guangfu , Ma Hongxia , Wu Chen , Li Lian , Song Fengju , Zeng YiXin , Jiang Yue , Chen Jiaping , Wang Cheng , Zhu Meng , Zhou Wen , Du Jiangbo , Xiang Yongbing , Shu Xiao‐Ou , Hu Zhibin , Zhou Weiping , Chen Kexin , Xu Jianfeng , Jia Weihua , Lin Dongxin , Zheng Wei , Shen Hongbing
Published: September 2016

The familial aggregation indicated the inheritance of cancer risk. Recent genome‐wide association studies (GWASs) have identified a number of common single‐nucleotide polymorphisms (SNPs). Following heritability analyses have shown that SNPs could explain a moderate amount of variance for different cancer phenotypes among Caucasians. However, little information was available in Chinese population. We performed a genome‐wide complex trait analysis for common cancers at nine anatomical sites in Chinese population (14,629 cancer cases vs. 17,554 controls) and estimated the heritability of these cancers based on the common SNPs. We found that common SNPs explained certain amount of heritability with significance for all nine cancer sites: gastric cancer (20.26%), esophageal squamous cell carcinoma (19.86%), colorectal cancer (16.30%), lung cancer (LC) (15.17%), and epithelial ovarian cancer (13.31%), and a similar heritability around 10% for hepatitis B virus‐related hepatocellular carcinoma, prostate cancer, breast cancer and nasopharyngeal carcinoma. We found that nearly or less than 25% change was shown when removing the regions expanding 250 kb or 500 kb upward and downward of the GWAS‐reported SNPs. We also found strong linear correlations between variance partitioned by each chromosome and chromosomal length only for LC (R2 = 0.641, p = 0.001) and esophageal squamous cell cancer (R2 = 0.633, p = 0.002), which implied us the complex heterogeneity of cancers. These results indicate polygenic genetic architecture of the nine common cancers in Chinese population. Further efforts should be made to discover the hidden heritability of different cancer types among Chinese.
Cancer stem cells: A product of clonal evolution?
Authors: van Niekerk Gustav , Davids Lester M. , Hattingh Suzèl M. , Engelbrecht Anna‐Mart
Published: September 2016

The cancer stem cell (CSC) model has emerged as a prominent paradigm for explaining tumour heterogeneity. CSCs in tumour recurrence and drug resistance have also been implicated in a number of studies. In fact, CSCs are often identified by their expression of drug‐efflux proteins which are also highly expressed in normal stem cells. Similarly, pro‐survival or proliferation signalling often exhibited by stem cells is regularly reported as being upregulated by CSC. Here we review evidence suggesting that many aspects of CSCs are more readily described by clonal evolution. As an example, cancer cells often exhibit copy number gains of genes involved in drug‐efflux proteins and pro‐survival signalling. Consequently, clonal selection for stem cell traits may result in cancer cells developing “stemness” traits which impart a fitness advantage, without strictly following a CSC model. Finally, since symmetric cell division would give rise to more cells than asymmetric division, it is expected that more advanced tumours would depart from a CSC. Collectively, these observations suggest clonal evolution may explain many aspects of the CSC.
Good performance of p16/ki‐67 dual‐stained cytology for surveillance of women treated for high‐grade CIN
Authors: Polman Nicole J. , Uijterwaal Margot H. , Witte Birgit I. , Berkhof Johannes , van Kemenade Folkert J. , Spruijt Johan W.M. , van Baal W. Marchien , Graziosi Peppino G.C.M. , van Dijken Dorenda K.E. , Verheijen René H.M. , Helmerhorst Theo J.M. , Steenbergen Renske D.M. , Heideman Daniëlle A.M. , Ridder Ruediger , Snijders Peter J.F. , Meijer Chris J.L.M.
Published: September 2016

Women treated for high‐grade cervical intraepithelial neoplasia (CIN) are at risk of recurrent CIN Grade 2 or worse (rCIN2+). Currently, posttreatment monitoring is performed using cytology or cytology/high‐risk (hr)HPV cotesting. This study aimed to evaluate the performance of p16/Ki‐67 dual‐stained cytology (p16/Ki‐67) for posttreatment monitoring. Three hundred and twenty‐three women treated for high‐grade CIN in the SIMONATH study underwent close surveillance by cytology, hrHPV and DNA methylation marker testing up to 12 months posttreatment. Histological endpoints were ascertained by colposcopy with biopsy at 6 and/or 12 months. p16/Ki‐67 dual‐staining was performed on residual liquid‐based cytology samples obtained at, or shortly before biopsy collection. Clinical performance estimates of cytology, hrHPV, p16/Ki‐67 testing and combinations thereof for the detection of rCIN2+ were determined and compared to each other. Sensitivity of p16/Ki‐67 for rCIN2+ (69.2%) was nonsignificantly lower than that of cytology (82.1%; ratio 0.84, 95% CI: 0.71–1.01), but significantly lower than that of hrHPV testing (84.6%; ratio 0.82, 95% CI: 0.68–0.99). Specificity of p16/Ki‐67 for rCIN2+ (90.4%) was significantly higher compared to both cytology (70.8%; ratio 1.28, 95% CI: 1.19–1.37) and hrHPV testing (76.2%; ratio 1.19, 95% CI: 1.12–1.26). Overall, hrHPV testing showed very high sensitivity, along with a good specificity. When considering cotesting, combined p16/Ki‐67/hrHPV testing showed rCIN2+ sensitivity comparable to cytology/hrHPV cotesting (87.2%vs. 89.7%; ratio 0.97, 95% CI: 0.92–1.03), but with significantly increased specificity (74.2%vs. 58.1%; ratio 1.28, 95% CI: 1.19–1.38). Thus, when considered in combination with hrHPV, p16/Ki‐67 might be an attractive approach for surveillance of women treated for high‐grade CIN.
Genetically encoded photocrosslinkers for identifying and mapping protein‐protein interactions in living cells
Authors: Yang Yi , Song Haiping , Chen Peng R.
Published: September 2016

Protein‐protein interactions (PPIs) play pivotal roles in regulation of many biological processes. Conventional methods are capable of investigating stable and strong interactions within protein complexes, but remain difficult for studying dynamic, transient, and weak PPIs. Herein we review photo‐affinity unnatural amino acids that can be site‐specifically incorporated into a protein of interest to covalently trap noncovalent PPIs under living conditions. A newly developed cleavable photocrosslinker from our group will also be introduced, which facilitated the prey‐bait separation for better enrichment and identification of photocrosslinked PPI complexes. © 2016 IUBMB Life, 68(11):879–886, 2016
Direct and label‐free detection of the human growth hormone in urine by an ultrasensitive bimodal waveguide biosensor
Authors: González‐Guerrero Ana Belén , Maldonado Jesús , Dante Stefania , Grajales Daniel , Lechuga Laura M.
Published: September 2016

A label‐free interferometric transducer showing a theoretical detection limit for homogeneous sensing of 5 × 10–8 RIU, being equivalent to a protein mass coverage resolution of 2.8 fg mm–2, is used to develop a high sensitive biosensor for protein detection. The extreme sensitivity of this transducer combined with a selective bioreceptor layer enables the direct evaluation of the human growth hormone (hGH) in undiluted urine matrix in the 10 pg mL–1 range.

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Comparative evaluation of a heparin‐citrate anticoagulation for LDL‐apheresis in two primary apheresis systems
Authors: Handschel Doris , Etienne Janssens Michiel , Gericke Marion , De Reys Stef , Borberg Helmut
Published: September 2016

BACKGROUND: As COBE Spectra has been replaced in many parts of the world, we describe a new protocol for low‐density lipoprotein (LDL)‐apheresis performed on familial hypercholesterolemia patients for the Spectra Optia platform. METHODS: For all procedures, after administering a bolus of heparin of 2,500 U, 10,000 U of heparin added to a 600 ml ACD‐A bag was used as anticoagulant (AC). In a first phase (A), 16 apheresis procedures with COBE Spectra using an inlet:AC ratio of 25:1 were compared to 18 LDL‐apheresis treatments with Spectra Optia at split Inlet:AC ratios of 16:1/18:1 or 20:1/25:1. Platelet activation and coagulation markers were assessed. In a follow‐up phase (B), 20 procedures on Spectra Optia using an inlet:AC ratio of 20:1 were performed. RESULTS: Although coagulation markers and platelet activation analyzed were similar in both apheresis devices used, COBE Spectra procedures did not show any visual clumping in the sets. Visual analysis of clumping was highest in the Spectra Optia's 20:1/25:1 AC regimen (5/8 procedures). For the lowest Spectra Optia, AC regimen and during the follow‐up phase reversible clump formation in the disposable set was similar (1/10 procedures). Clumping was successfully reversed in all cases by temporarily lowering the inlet:AC ratio to 18:1. Blood cell counts (WBC, Plt, Hct) were similar for both COBE Spectra and Spectra Optia procedures. Spectra Optia had a significantly higher plasma removal efficiency versus COBE Spectra (84% vs.75%, P < .05). No serious adverse events were observed. CONCLUSION: Apheresis procedures on the Spectra Optia system with low‐dose heparin‐citrate anticoagulation are feasible and safe.
Hyperexcitability of Mesencephalic Trigeminal Neurons and Reorganization of Ion Channel Expression in a Rett Syndrome Model
Authors: Oginsky Max F. , Cui Ningren , Zhong Weiwei , Johnson Christopher M. , Jiang Chun
Published: September 2016

People with Rett syndrome (RTT) have defects in motor function also seen in Mecp2‐null mice. Motor function depends on not only central motor commands but also sensory feedback that is vulnerable to changes in excitability of propriosensory neurons. Here we report evidence for hyperexcitability of mesencephalic trigeminal (Me5) neurons in Mecp2‐null mice and a novel cellular mechanism for lowering its impact. In in vitro brain slices, the Me5 neurons in both Mecp2−/Y male and symptomatic Mecp2+/− female mice were overly excitable showing increased firing activity in comparison to their wild‐type (WT) male and asymptomatic counterparts. In Mecp2−/Y males, Me5 neurons showed a reduced firing threshold. Consistently, the steady‐state activation of voltage‐gated Na+ currents (INa) displayed a hyperpolarizing shift in the Mecp2‐null neurons with no change in the INa density. This seems to be due to NaV1.1, SCN1B and SCN4B overexpression and NaV1.2 and SCN3B under‐expression. In contrast to the hyperexcitability, the sag potential and postinhibitory rebound (PIR) were reduced in Mecp2‐null mice. In voltage‐clamp, the IH density was deficient by ∼33%, and the steady‐state half‐activation had a depolarizing shift of ∼10 mV in the Mecp2‐null mice. Quantitative PCR analysis indicated that HCN2 was decreased, HCN1 was upregulated with no change in HCN4 in Mecp2−/Y mice compared to WT. Lastly, blocking IH reduced the firing rate much more in WT than in Mecp2‐null neurons. These data suggest that the Mecp2 defect causes an increase in Me5 neuronal excitability likely attributable to alterations in INa, meanwhile IH is reduced likely altering neuronal excitability as well. J. Cell. Physiol. 232: 1151–1164, 2017. © 2016 Wiley Periodicals, Inc.
Evaluation of Evolocumab (AMG 145), a Fully Human Anti‐PCSK9 IgG2 Monoclonal Antibody, in Subjects With Hepatic Impairment
Authors: Gibbs John P. , Slatter J. Greg , Egbuna Ogo , Geller Michelle , Hamilton Lisa , Dias Clapton S. , Xu Ren Y. , Johnson Jessica , Wasserman Scott M. , Emery Maurice G.
Published: September 2016

Evolocumab binds PCSK9, increasing low‐density lipoprotein cholesterol (LDL‐C) receptors and lowering LDL‐C. Target‐mediated evolocumab elimination is attributable to PCSK9 binding. As circulating PCSK9 and LDL‐C levels are primarily regulated by the liver, we compared evolocumab pharmacokinetics, pharmacodynamics, and safety in individuals with and without hepatic impairment. An open‐label, parallel‐group study evaluated the pharmacokinetics of evolocumab in hepatic‐impaired (Child‐Pugh Class A or B) or healthy adults. Participants were classified as having no, mild, or moderate hepatic impairment (n = 8/group) and received a single 140‐mg evolocumab dose. Assessments of unbound evolocumab and PCSK9 were made predose and postdose. Adverse events were monitored throughout the study. No significant association was observed between baseline PCSK9 and increasing level of hepatic impairment. No difference in extent and time course of PCSK9 or LDL‐C reduction was observed despite an apparent decrease in mean unbound evolocumab exposure with increasing hepatic impairment (Jonckheere‐Terpstra trend test; maximum serum concentration P = .18; area under the curve P = .09). Maximum reductions were observed in moderately impaired subjects vs healthy individuals: mean maximum serum concentration –34%; mean area under the concentration‐time curve (AUC) –47%. On average, unbound PCSK9 serum concentrations fell by >80% at 4 hours after a single evolocumab dose. Mean (95% confidence interval) maximum LDL‐C reductions in the healthy, mild, and moderate groups were –57% (–64% to –48%), –70% (–75% to –63%), and –53% (–61% to –43%), respectively. No safety risks were identified. These results support evolocumab use without dose adjustment in patients with active liver disease and mild or moderate hepatic impairment.
A haploid HSV‐1 genome platform for vector development: testing of the tetracycline‐responsive switch shows interference by infected cell protein 0
Authors: Khalique Hena , López Marco Jorge , Lim Filip
Published: September 2016

Background

Although herpes simplex virus type 1 (HSV‐1) has outstanding properties for gene delivery vectors and its genome is available in bacterial artificial chromosomes (BACs) for mutagenesis studies, one impediment is the presence of approximately 15.4 kb of DNA sequences that are duplicated in the HSV‐1 genome, complicating vector construction and stability.

Methods

As a useful platform for building HSV‐1 vectors, we have constructed a fully haploid HSV‐1 genome BAC by deletion of one of these repeats, confirming that viral propagation in culture is not impaired. We used this ΔIR mutant to subsequently investigate whether the insertion of tetracycline‐responsive tetO elements into the ICP34.5–ICP0 gene region can be used to control HSV‐1 lytic replication.

Results

The results of the present study show that ΔIR mutants deleted for ICP34.5 are viable for replication but not when the ICP0 promoter is also disrupted, thus indicating that regulation of infected cell protein 0 (ICP0) levels in the absence of ICP34.5 could be a viable means for controlling growth of HSV‐1 vectors. Surprisingly, however, the tetO elements inserted into the ICP0 promoter did not confer ligand responsiveness to growth or ICP0 expression. Further analysis by transfection experiments revealed that ICP0 itself interferes with the tetracycline switch and reduces the the inducibility of this system.

Conclusions

Our new haploid HSV‐1 BAC is a useful platform for building multiply deleted HSV‐1 vectors. Deletion of the gene for ICP34.5 in this backbone renders viral growth dependent on ICP0, although ICP0 expression could not be regulated by tet‐responsive transcriptional regulators.
Effect of silybin on the fibrillation of hen egg‐white lysozyme
Authors: Zeng Hua‐jin , Miao Min , Yang Ran , Qu Ling‐bo
Published: September 2016

In this study, the fibrillation of hen egg‐white lysozyme (HEWL) in the absence and presence of different concentrations of silybin was studied by thioflavin T spectroscopy, Congo red binding assays, 8‐anilino‐1‐naphthalenesulfonic acid (ANS) fluorescence assay, circular dichroism, and transmission electron microscopy. The experimental results indicated that not only the fibrillation of HEWL at high temperature (65°C) and low pH (pH = 2.0) could be inhibited effectively by silybin but also the inhibition of HEWL by silybin followed a dose‐dependent manner. Molecular docking studies indicated that 2 possible binding modes could be found in the interaction between silybin and HEWL via van der Waals forces and electrostatic forces as well as hydrogen bonding. One of these 2 conformations was directly entered into the cavity of HEWL (binding site I); the other was bound to the surface of HEWL (binding site II). In this way, silybin could not only increase the hydrophobicity of the cavity or the surface of HEWL but also influence the microenvironment of the binding site, which was able to stabilize the structure of HEWL and delay the process of HEWL fibrosis.
Theoretical investigation of low detection sensitivity for underivatized carbohydrates in ESI and MALDI
Authors: Chen Jien‐Lian , Lee Chuping , Lu I‐Chung , Chien Chia‐Lung , Lee Yuan‐Tseh , Hu Wei‐Ping , Ni Chi‐Kung
Published: September 2016

Electrospray ionization (ESI) and matrix‐assisted laser desorption/ionization (MALDI) mainly generate protonated ions from peptides and proteins but sodiated (or potassiated) ions from carbohydrates. The ion intensities of sodiated (or potassiated) carbohydrates generated by ESI and MALDI are generally lower than those of protonated peptides and proteins. Ab initio calculations and transition state theory were used to investigate the reasons for the low detection sensitivity for underivatized carbohydrates. We used glucose and cellobiose as examples and showed that the low detection sensitivity is partly attributable to the following factors. First, glucose exhibits a low proton affinity. Most protons generated by ESI or MALDI attach to water clusters and matrix molecules. Second, protonated glucose and cellobiose can easily undergo dehydration reactions. Third, the sodiation affinities of glucose and cellobiose are small. Some sodiated glucose and cellobiose dissociate into the sodium cations and neutral carbohydrates during ESI or MALDI process. The increase of detection sensitivity of carbohydrates in mass spectrometry by various methods can be rationalized according to these factors. Copyright © 2016 John Wiley & Sons, Ltd.
Mid‐elevation ecosystems of Panama: future uncertainties in light of past global climatic variability
Authors: Correa‐Metrio Alexander , Vélez Maria I. , Escobar Jaime , St‐Jacques Jeannine‐Marie , López‐Pérez Minerva , Curtis Jason , Cosford Jason
Published: September 2016

Modern changes in regional climates will result in high ecosystem turnover and substantial biodiversity rearrangements. Understanding these changes requires palaeoecological studies at temporal resolutions comparable to the time window at which modern climate change is occurring. Here we present a multi‐proxy, high‐resolution record of forest and lake ecosystem change that occurred during the last 1100 years at middle elevations in Panama. From ∼900 to 1400 CE, regional forest and lake ecosystems were characterized by high seasonality, probably associated with both high El Niño activity and higher global temperatures. At ∼1400 CE, an abrupt transition marked the decoupling of forest and lake responses, with forest responding mostly to local patterns of human occupation, and lake trophic status being controlled mostly by the regional precipitation–evaporation balance, possibly associated with solar irradiance. Factors that played important roles in shaping regional ecosystems during the last 1100 years will probably again play critical roles within the coming decades, i.e. higher precipitation seasonality and higher temperatures. Past responses of the system, together with pervasive human activities, suggest that future conditions will simplify mid‐elevation forests. Given the importance of these geographical locations as hotspots of biological diversity, substantial losses of global biodiversity are foreseen.
Effervescence‐assisted dispersive solid‐phase extraction using ionic‐liquid‐modified magnetic β‐cyclodextrin/attapulgite coupled with high‐performance liquid chromatography for fungicide detection in honey and juice
Authors: Wu Xiaoling , Yang Miyi , Zeng Haozhe , Xi Xuefei , Zhang Sanbing , Lu Runhua , Gao Haixiang , Zhou Wenfeng
Published: September 2016

In this study, a simple effervescence‐assisted dispersive solid‐phase extraction method was developed to detect fungicides in honey and juice. Most significantly, an innovative ionic‐liquid‐modified magnetic β‐cyclodextrin/attapulgite sorbent was used because its large specific surface area enhanced the extraction capacity and also led to facile separation. A one‐factor‐at‐a‐time approach and orthogonal design were employed to optimize the experimental parameters. Under the optimized conditions, the entire extraction procedure was completed within 3 min. In addition, the calibration curves exhibited good linearity, and high enrichment factors were achieved for pure water and honey samples. For the honey samples, the extraction efficiencies for the target fungicides ranged from 77.0 to 94.3% with relative standard deviations of 2.3–5.44%. The detection and quantitation limits were in the ranges of 0.07–0.38 and 0.23–1.27 μg/L, respectively. Finally, the developed technique was successfully applied to real samples, and satisfactory results were achieved. This analytical technique is cost‐effective, environmentally friendly, and time‐saving.
Rapid characterization of the chemical constituents of Cortex Fraxini by homogenate extraction followed by UHPLC coupled with Fourier transform ion cyclotron resonance mass spectrometry and GC–MS
Authors: Wang Yinan , Han Fei , Song Aihua , Wang Miao , Zhao Min , Zhao Chunjie
Published: September 2016

Cortex Fraxini is an important traditional Chinese medicine. In this work, a rapid and reliable homogenate extraction method was applied for the fast extraction for Cortex Fraxini, and the method was optimized by response surface methodology. Ultra high performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry and gas chromatography with mass spectrometry were established for the separation and characterization of the constituents of Cortex Fraxini. Liquid chromatography separation was conducted on a C18 column (150 mm × 2.1 mm, 1.8 μm), and gas chromatography separation was performed on a capillary with a 5% phenyl‐methylpolysiloxane stationary phase (30 m × 0.25 mm × 0.25 mm) by injection of silylated samples. According to the results, 33 chemical compounds were characterized by liquid chromatography with mass spectrometry, and 11 chemical compounds were characterized by gas chromatography with mass spectrometry, and coumarins were the major components characterized by both gas chromatography with mass spectrometry and liquid chromatography with mass spectrometry. The proposed homogenate extraction was an efficient and rapid method, and coumarins, phenylethanoid glycosides, iridoid glycosides, phenylpropanoids, and lignans were the main constituents of Cortex Fraxini. This work laid the foundation for further study of Cortex Fraxini and will be helpful for the rapid extraction and characterization of ingredients in other traditional Chinese medicines.
Fungal contribution in chondroradionecrosis of the larynx
Authors: Worthen Mary , Jusufbegovic Mia , Bumpous Jeffrey M. , Vaughn Andrew , Cash Elizabeth , Yang Xiu , Fichandler Craig , Tennant Paul
Published: September 2016

Objective

To assess the prevalence of invasive fungal elements in the specimens of patients who underwent salvage total laryngectomy for chondroradionecrosis (CRN) in the absence of recurrent or persistent malignancy.

Study Design

Retrospective chart review.

Setting

Tertiary academic medical center.

Methods

One hundred fifty‐nine patients were identified who underwent salvage total laryngectomy. Pathology reports were reviewed, and all laryngectomy specimens that did not contain residual malignancy were reevaluated for evidence of invasive fungal elements.

Results

Twelve of 159 (7.5%) patients who underwent total laryngectomy after primary radiotherapy or chemoradiotherapy had no evidence of residual malignancy. Each of these specimens contained histopathologic evidence of CRN; invasive fungal elements were identified in 25%. There was no statistical difference in demographic or treatment‐related variables between patients who underwent salvage total laryngectomy with evidence of persistent or recurrent malignancy in the laryngectomy specimen versus patients without evidence of tumor on final histopathologic analysis. Patients with evidence of ulceration or necrosis in the laryngectomy specimen had reduced overall survival, irrespective of the presence of persistent malignancy (hazard ratio = 2.923, 95% confidence interval = 1.023–8.352, P = .045).

Conclusion

Among salvage total laryngectomy patients, no difference was identified between patients who underwent total laryngectomy for recurrent or persistent malignancy after primary radiotherapy and those who received total laryngectomy without evidence of malignancy in their specimens. Invasive fungal elements were detected in several laryngectomy specimens that did not contain residual malignancy. Empiric antifungal therapy may therefore benefit patients diagnosed with CRN who are at risk for progression to nonfunctional larynx. Patients with evidence of ulceration or necrosis in the salvage laryngectomy specimen had worse overall survival.

Level of Evidence

4. Laryngoscope, 127:E159–E165, 2017