bluuebunny/crossref_metadata_2025 huggingface dataset:
Inverse metabolic engineering to improve Escherichia coli as an N‐glycosylation host
Authors: Pandhal Jagroop , Woodruff Lauren B. A. , Jaffe Stephen , Desai Pratik , Ow Saw Y. , Noirel Josselin , Gill Ryan T. , Wright Phillip C.
Published: April 2013

An inverse metabolic engineering strategy was used to select for Escherichia coli cells with an increased capability to N‐glycosylate a specific target protein. We developed a screen for E. coli cells containing extra‐chromosomal DNA fragments for improved ability to add precise sugar groups onto the AcrA protein using the glycosylation system from Campylobacter jejuni. Four different sized (1, 2, 4, and 8 kb) genomic DNA libraries were screened, and the sequences that conferred a yield advantage were determined. These advantageous genomic fragments were mapped onto the E. coli W3110 chromosome. Five candidate genes (identified across two or more libraries) were subsequently selected for forward engineering verification in E. coli CLM24 cells, utilizing a combination of internal standards for absolute quantitation and pseudo‐selective reaction monitoring (pSRM) and Western blotting validation. An increase in glycosylated protein was quantified in cells overexpressing 4‐α‐glucantransferase and a phosphoenolpyruvate‐dependent sugar phosphotransferase system, amounting to a 3.8‐fold (engineered cells total = 5.3 mg L−1) and 6.7‐fold (engineered cells total = 9.4 mg L−1) improvement compared to control cells, respectively. Furthermore, increased glycosylation efficiency was observed in cells overexpressing enzymes involved with glycosylation precursor synthesis, enzymes 1‐deoxyxylulose‐5‐phosphate synthase (1.3‐fold) and UDP‐N‐acetylglucosamine pyrophosphorylase (1.6‐fold). To evaluate the wider implications of the engineering, we tested a modified Fc fragment of an IgG antibody as the target glycoprotein with two of our engineered cells, and achieved a ca. 75% improved glycosylation efficiency. Biotechnol. Bioeng. 2013; 110:2482–2493. © 2013 Wiley Periodicals, Inc.
In silico maturation of binding‐specificity of DNA aptamers against Proteus mirabilis
Authors: Savory Nasa , Lednor Danielle , Tsukakoshi Kaori , Abe Koichi , Yoshida Wataru , Ferri Stefano , Jones Brian V , Ikebukuro Kazunori
Published: April 2013

Proteus mirabilis is a prominent cause of catheter‐associated urinary tract infections (CAUTIs) among patients undergoing long‐term bladder catheterization. There are currently no effective means of preventing P. mirabilis infections, and strategies for prophylaxis and rapid early diagnosis are urgently required. Aptamers offer significant potential for development of countermeasures against P. mirabilis CAUTI and are an ideal class of molecules for the development of diagnostics and therapeutics. Here we demonstrate the application of Cell‐SELEX to identify DNA aptamers that show high affinity for P. mirabilis. While the aptamers identified displayed high affinity for P. mirabilis cells in dot blotting assays, they also bound to other uropathogenic bacteria. To improve aptamer specificity for P. mirabilis, an in silico maturation (ISM) approach was employed. Two cycles of ISM allowed the identification of an aptamer showing 36% higher specificity, evaluated as a ratio of binding signal for P. mirabilis to that for Escherichia coli (also a cause of CAUTI and the most common urinary tract pathogen). Aptamers that specifically recognize P. mirabilis would have diagnostic and therapeutic values and constitute useful tools for studying membrane‐associated proteins in this organism. Biotechnol. Bioeng. 2013;110: 2573–2580. © 2013 Wiley Periodicals, Inc.
Evaluating differences of metabolic performances: Statistical methods and their application to animal cell cultivations
Authors: Hädicke O. , Lohr V. , Genzel Y. , Reichl U. , Klamt S.
Published: April 2013

In cell culture process development, monitoring and analyzing metabolic key parameters is routinely applied to demonstrate specific advantages of one experimental setup over another. It is of great importance that the observed differences and expected improvements are practically relevant and statistically significant. However, a systematic assessment whether observed differences in metabolic rates are statistically significant or not is often missing. This can lead to time‐consuming and costly changes of an established biotechnological process due to false positive results. In the present work we demonstrate how well‐established statistical tools can be employed to analyze systematically different sources of variations in metabolic rate determinations and to assess, in an unbiased way, their implications on the significance of the observed differences. As a case study, we evaluate differing growth characteristics and metabolic rates of the avian designer cell line AGE1.CR.pIX cultivated in a stirred tank reactor and in a wave bioreactor. Although large differences in metabolic rates and cell growth were expected (due to different aeration, agitation, pH‐control, etc.) and partially observed (up to 79%), our results show that the inter‐experimental variance between experiments performed under identical conditions but with different pre‐cultures is a major contributor to the overall variance of metabolic rates. The lower bounds of the overall relative standard deviations for specific metabolic rates were between 4% and 73%. The application of available statistical methods revealed that the observed differences were statistically not significant and consequently insufficient to confirm relevant differences between both cultivation systems. Our study provides a general guideline for statistical analyses in comparative cultivation studies and emphasizes the necessity to account for the inter‐experimental variance (mainly caused by biological variation) to avoid false‐positive results. Biotechnol. Bioeng. 2013;110: 2633–2642. © 2013 Wiley Periodicals, Inc.
Consolidated bioprocessing of highly concentrated jerusalem artichoke tubers for simultaneous saccharification and ethanol fermentation
Authors: Guo Lihao , Zhang Jian , Hu Fengxian , Dy Ryu Dewey , Bao Jie
Published: April 2013

Consolidated bioprocessing (CBP) of Jerusalem artichoke tuber (Jat) for ethanol production is one of the most promising options for an alternate biofuel technology development. The technical barriers include the weak saccharolytic enzyme (inulinase) activity of the fermentation strain, and the well mixing of the high viscous fermentation slurry at the highly concentrated Jat loading. In this study, Saccharomyces cerevisiae DQ1 was found to produce relatively large amount of inulinase for hydrolysis of inulin in Jat, and the helical ribbon stirring bioreactor used provided well mixing performance under the high Jat loading. Even a highly concentrated Jat loading up to 35% (w/w) in the helical ribbon bioreactor for CBP was allowed. The results obtained from this study have demonstrated a feasibility of developing a CBP process technology in the helical ribbon bioreactor for ethanol production at a high yield 128.7 g/L and the theoretical yield 73.5%, respectively. This level of ethanol yield from Jat is relatively higher than others reported so far. The results of this study could provide a practical CBP process technology in the helical ribbon bioreactor for economically sustainable alternate biofuel production using highly concentrated inulin containing biomass feedstock such as Jat, at least 35%. Biotechnol. Bioeng. 2013;110: 2606–2615. © 2013 Wiley Periodicals, Inc.
Highly Strained Heterometallacycles of Group 4 Metallocenes with Bis(diphenylphosphino)methanide Ligands
Authors: Haehnel Martin , Hansen Sven , Priebe Jacqueline B. , Spannenberg Anke , Arndt Perdita , Brückner Angelika , Rosenthal Uwe
Published: April 2013

A study of the coordination chemistry of different bis(diphenylphosphino)methanide ligands [Ph2PC(X)PPh2] (X=H, SiMe3) with Group 4 metallocenes is presented. The paramagnetic complexes [Cp2Ti{κ2‐P,P‐Ph2PC(X)PPh2}] (X=H (3 a), X=SiMe3 (3 b)) have been prepared by the reactions of [(Cp2TiCl)2] with [Li{C(X)PPh2}2(thf)3]. Complex 3 b could also be synthesized by reaction of the known titanocene alkyne complex [Cp2Ti(η2‐Me3SiC2SiMe3)] with Ph2PC(H)(SiMe3)PPh2 (2 b). The heterometallacyclic complex [Cp2Zr(H){κ2‐P,P‐Ph2PC(H)PPh2}] (4 aH) has been prepared by reaction of the Schwartz reagent with [Li{C(H)PPh2}2(thf)3]. Reactions of [Cp2HfCl2] with [Li{C(X)PPh2}2(thf)3] gave the highly strained corresponding metallacycles [Cp2M(Cl){κ2‐P,P‐Ph2PC(X)PPh2}] (5 aCl and 5 bCl) in very good yields. Complexes 3 a, 4 aH, and 5 aCl have been characterized by X‐ray crystallography. Complex 3 a has also been characterized by EPR spectroscopy. The structure and bonding of the complexes has been investigated by DFT analysis. Reactions of complexes 4 aH, 5 aCl, and 5 bCl did not give the corresponding more unsaturated heterometallacyclobuta‐2,3‐dienes.
Advances in Stroke Prevention in Atrial Fibrillation: Enhanced Risk Stratification Combined With the Newer Oral Anticoagulants
Authors: Verheugt Freek W. A.
Published: April 2013

Patients with atrial fibrillation (AF) have an increased stroke risk compared with those in sinus rhythm, although the absolute risk for individual patients is modulated by the presence of various additional risk factors. Patient selection for oral anticoagulation for stroke prevention is based on risks of stroke and bleeding. Although CHADS2 (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, stroke or transient ischemic attack) is the most widely used scheme for evaluating stroke risk in patients with AF, several other stroke risk factors are not included; therefore, many patients' stroke risk may be underestimated, contributing to the underuse of anticoagulants. Furthermore, a substantial proportion of patients are categorized as being at moderate risk (CHADS2 = 1), and there has been some ambiguity regarding optimum thromboprophylaxis in this group. The refinement of CHADS2, CHA2DS2‐VASc (Congestive heart failure, Hypertension, Age 75 years [2 points], Diabetes mellitus, Stroke or transient ischemic attack [2 points], Vascular disease, Age 65 to 74 years, Sex category [female]), considers additional risk factors. Its main advantage is its ability to identify patients truly at low risk of thromboembolism (CHA2DS2‐VASc = 0), who are unlikely to benefit from antithrombotic therapy. For all others, an oral anticoagulant may be the preferred approach, simplifying clinical decision making. Implementation of CHA2DS2‐VASc may also result in an increased proportion of patients receiving anticoagulation. The emergence of newer oral anticoagulants that can be given without routine coagulation monitoring, with improved benefit–risk profiles vs vitamin K antagonists, promises to simplify therapy for patients with AF at risk of stroke. This, coupled with advances in stroke risk stratification, is expected to improve patient outcomes and reduce the burden of AF‐related stroke.
Nucleation Barriers for the Cubic‐to‐Tetragonal Phase Transformation
Authors: Knüpfer Hans , Kohn Robert V. , Otto Felix
Published: April 2013

We are interested in the phase transformation from austenite to martensite. This transformation is typically accompanied by the generation and growth of small inclusions of martensite. We consider a model from geometrically linear elasticity with sharp energy penalization for phase boundaries. Focusing on a cubic‐to‐tetragonal phase transformation, we show that the minimal energy for an inclusion of martensite scales like$\max \{ V^{2/3}, V^{9/11} \}$in terms of the volumeV. Moreover, our arguments illustrate the importance of self‐accommodation for achieving the minimal scaling of the energy. The analysis is based on Fourier representation of the elastic energy. © 2012 Wiley Periodicals, Inc.
Physical and Medium Access Control criteria for the optimal Medium Access Control protocol data unit size in Automatic Repeat Request‐enabled connections in IEEE 802.16e/ WiMAX systems
Authors: Sharon Oran , Alpert Yaron
Published: April 2013

In this paper, we address an aspect of the mutual influence between the physical (PHY) layer budding blocks (forward error correction (FEC) blocks) and the medium access control (MAC) level allocations in the uplink and downlink of IEEE 802.16e/WiMAX systems. In these systems, it is possible to transmit MAC level frames, denoted MAC protocol data units (PDUs), such that a PDU contains an integral number of fixed size data blocks. We compute the optimal size of a PDU according to two criteria, one related to the PHY layer and one related to the MAC layer. In relation to the PHY layer, the criterion maximizes the average number of data bits that are transmitted in a PHY slot. In relation to the MAC layer, the criterion maximizes the goodput of the PDU. The goodput depends on the success probability of the PDU, which in turn depends on the FEC blocks over which the PDU is allocated. We then compare the maximal PDU goodputs in different sizes of the FEC blocks and the data blocks. The main outcome is that the PDU goodput is sensitive in those cases in which data blocks are very large. We also give guidelines on how to choose the best modulation/coding scheme to use in a scenario where the signal‐to‐noise ratio can change significantly during transmissions, to maximize the PDU goodput. Finally, we compare between the two criteria. Copyright © 2013 John Wiley & Sons, Ltd.
Identification of bioactive peptides in hypoallergenic infant milk formulas by CE‐TOF‐MS assisted by semiempirical model of electromigration behavior
Authors: Català‐Clariana Sergio , Benavente Fernando , Giménez Estela , Barbosa José , Sanz‐Nebot Victoria
Published: April 2013

Biologically active peptides derived from complex bovine milk protein hydrolysates are of particular interest in food science and nutrition because they have been shown to play different physiological roles, providing benefits in human health. In this study, we used CE‐TOF‐MS for separation and identification of bioactive peptides in three hypoallergenic infant milk formulas. An appropriate sample cleanup using a citrate buffer with DTT and urea followed by SPE with Sep‐Pack® C18 and StrataXTM cartridges allowed the detection of a large number of low molecular mass bioactive peptides. This preliminary identification was solely based on the measured experimental monoisotopic molecular mass values (Mexp). Later, we evaluated the classical semiempirical relationships between electrophoretic mobility and charge‐to‐mass ratio (me vs. q/Mα, α = 1/2 for the classical polymer model) to describe their migration behavior. The assistance of migration prediction proved to be useful to improve reliability of the identification, avoiding misinterpretations and solving some identity conflicts. After revision, the identity of 24, 30, and 38 bioactive peptides was confirmed in each of the three infant milk formulas. A significant number of these peptides were reported as inhibitors of angiotensin‐converting enzyme, however, the presence of sequences with other biological activities such as antihypertensive, antithrombotic, hypocholesterolemic, immunomodulation, cytotoxicity, antioxidant, antimicrobial, antigenic, or opioid was also confirmed.
Winners and losers: Ecological and biogeochemical changes in a warming ocean
Authors: Dutkiewicz S. , Scott J. R. , Follows M. J.
Published: April 2013

We employ a marine ecosystem model, with diverse and flexible phytoplankton communities, coupled to an Earth system model of intermediate complexity to explore mechanisms that will alter the biogeography and productivity of phytoplankton populations in a warming world. Simple theoretical frameworks and sensitivity experiments reveal that ecological and biogeochemical changes are driven by a balance between two impacts of a warming climate: higher metabolic rates (the “direct” effect), and changes in the supply of limiting nutrients and altered light environments (the “indirect” effect). On globally integrated productivity, the two effects compensate to a large degree. Regionally, the competition between effects is more complicated; patterns of productivity changes are different between high and low latitudes and are also regulated by how the supply of the limiting nutrient changes. These complex regional patterns are also found in the changes to broad phytoplankton functional groups. On the finer ecological scale of diversity within functional groups, we find that ranges of some phytoplankton types are reduced, while those of others (potentially minor players in the present ocean) expand. Combined change in areal extent of range and in regionally available nutrients leads to global “winners and losers.” The model suggests that the strongest and most robust signal of the warming ocean is likely to be the large turnover in local phytoplankton community composition.
A discussion on the methods of extracting gravity wave perturbations from space‐based measurements
Authors: John Sherine Rachel , Kumar Karanam Kishore
Published: April 2013

The disparities in satellite‐based observations of global gravity wave activity are discussed in terms of methods used to extract the gravity wave perturbations from background and the sensitivity of the given satellite to the gravity wave spectrum. The temperature measurements from TIMED/SABER are used to obtain the global gravity wave maps in terms of their potential energies by employing two widely used methods to extract the gravity wave perturbations viz. (1) removal of 0–6 zonal wavenumber large‐scale waves and (2) high pass filter with cut‐off vertical wavelength at 10 km. The present study for the first time employed these two different methods on the same satellite observations to investigate the sensitivity of global gravity wave patterns and their magnitudes to the methods used to extract them. The results showed significant differences in the gravity wave potential energy magnitudes estimated by employing these two methods. Further, employing the first method on COSMIC‐measured temperature profiles, the global gravity wave pattern is estimated and the same is compared with that obtained using SABER observations. This comparison substantiated the assertion that using the same method to extract the gravity wave perturbations from different satellite observations yields the similar global gravity wave pattern. The present study thus provided very useful insights into the observed discrepancies among current global gravity wave patterns and it is envisaged that this is a step forward in unifying the existing methods to extract gravity wave parameters using space‐based observations.
Patatin-like phospholipase domain-containing 3 I148M affects liver steatosis in patients with chronic hepatitis B
Authors: Viganò Mauro , Valenti Luca , Lampertico Pietro , Facchetti Floriana , Motta Benedetta Maria , D'Ambrosio Roberta , Romagnoli Solange , Dongiovanni Paola , Donati Benedetta , Fargion Silvia , Colombo Massimo
Published: April 2013

Steatosis is a common histopathological feature of chronic hepatitis B (CHB) and has been associated with severity of liver disease. Recently, the rs738409 I148M patatin-like phospholipase domain-containing 3 (PNPLA3) polymorphism has been demonstrated to influence steatosis susceptibility and fibrosis progression in patients with different liver diseases, but no data are yet available for CHB. The aim of this study was to evaluate whether PNPLA3 I148M influences steatosis susceptibility in a large series of patients with CHB. We enrolled 235 treatment-naïve CHB patients consecutively examined by percutaneous liver biopsy. In ≥2-cm-long liver tissue cores, steatosis and fibrosis were staged by Kleiner and METAVIR scores, respectively. The I148M polymorphism was determined by Taqman assays. Steatosis was present in 146 (62%) patients, of whom 24 (10%) had severe (>33% of hepatocytes) steatosis. Steatosis was independently associated with age (odds ratio [OR]: 2.67; confidence interval [CI]: 1.50-4.92; for age ≥50 years), body mass index (BMI; OR, 2.84; CI, 1.30-6.76; for BMI ≥27.5 kg/m2), diabetes or impaired fasting glucose (OR, 4.45; CI, 1.10-30.0), and PNPLA3 148M allele (OR, 1.62; CI, 1.00-7.00; for each 148M allele). Independent predictors of severe steatosis were BMI (OR, 3.60; CI, 1.39-9.22; for BMI ≥27.5 kg/m2) and PNPLA3 148M allele (OR, 6.03; CI, 1.23-5.0; for each 148M allele). PNPLA3 148M alleles were associated with a progressive increase in severe steatosis in patients with acquired cofactors, such severe overweight and a history of alcohol intake (

P

= 0.005).

Conclusion

: In CHB patients, the PNPLA3 I148M polymorphism influences susceptibility to steatosis and, in particular, when associated with severe overweight and alcohol intake, severe steatosis. (Hepatology 2013;58:1245–1252)
IL-25 prevents and cures fulminant hepatitis in mice through a myeloid-derived suppressor cell-dependent mechanism
Authors: Sarra Massimiliano , Cupi Maria Laura , Bernardini Roberta , Ronchetti Giulia , Monteleone Ivan , Ranalli Marco , Franzè Eleonora , Rizzo Angelamaria , Colantoni Alfredo , Caprioli Flavio , Maggioni Marco , Gambacurta Alessandra , Mattei Maurizio , Macdonald Thomas T. , Pallone Francesco , Monteleone Giovanni
Published: April 2013

Fulminant hepatitis (FH) is a disease characterized by massive destruction of hepatocytes with severe impairment of liver function. The pathogenesis of FH is not fully understood, but hyperactivity of T cells and macrophages with excessive production of cytokines are important hallmarks of the condition. In this study, we investigated the role of interleukin (IL)−25 in FH. IL-25 expression was evaluated in patients with FH and in livers of mice with FH induced by D-galactosamine (D-Gal) and lipopolysaccharide (LPS). Mice were treated with IL-25 before D-Gal/LPS-induced FH and before or after concanavalin A (ConA)-induced FH. Mononuclear cells were isolated from livers of mice treated with or without IL-25 and analyzed for GR1+CD11b+ cells. CFSE-labeled T cells were cocultured with GR1+CD11b+ cells and their proliferation was evaluated by flow cytometry. Mice were also treated with a depleting anti-GR1 antibody before IL-25 and D-Gal/LPS administration. IL-25 was constitutively expressed in mouse and human liver and down-regulated during FH. IL-25 prevented D-Gal/LPS-induced FH and this effect was associated with increased infiltration of the liver with cells coexpressing GR1 and CD11b.

In vitro

studies showed that GR1+CD11b+ cells isolated from mice given IL-25 inhibited T-cell proliferation. Consistently,

in vivo

depletion of GR1+ cells abrogated the protective effect of IL-25 in experimental D-Gal/LPS-induced FH. IL-25 was both preventive and therapeutic in ConA-induced FH.

Conclusions

: IL-25 expression is markedly reduced during human and experimental FH. IL-25 promotes liver accumulation of GR1+CD11b+cells with immunoregulatory properties. (Hepatology 2013;58:1436–1450)
Children of Color and Parental Incarceration: Implications for Research, Theory, and Practice
Authors: Graham James A. , Harris Yvette R.
Published: April 2013

Practical information about culturally appropriate interventions with children of incarcerated parents (CIPs) of color and their families is notably sparse. This study uses a cultural–ecological perspective to contextualize individual, family, and legal issues inherent in many intervention programs for CIPs of color. The authors highlight demographic trends, review research limitations, and discuss ways that therapeutic models can help counselors address their clients' needs. Recommendations are provided for future interventions with this underserved population.

La información práctica sobre intervenciones culturalmente apropiadas con hijos de personas de color encarceladas (CIPs) por sus siglas en inglés y sus familias es notablemente escasa. Este estudio usa una perspectiva cultural‐ecológica para contextualizar los asuntos individuales, familiares y legales inherentes a muchos programas de intervención para CIPs. Los autores destacan las tendencias demográficas, las limitaciones en la investigación de reseñas, y discuten formas en las que los modelos terapéuticos pueden ayudar a los consejeros a abordar las necesidades de sus clientes. Se proporcionan recomendaciones para intervenciones futuras con esta población desatendida.
A new TGF‐β3 controlled‐released chitosan scaffold for tissue engineering synovial sheath
Authors: Jiang Ke , Wang Ziming , Du Quanyin , Yu Jiang , Wang Aimin , Xiong Yan
Published: April 2013

The post‐operative outcome of flexor tendon healing remains limited by flexor tendon adhesion that reduces joint range of motion. Despite improvement in different methods, peritendinous adhesion formation continues to present a formidable challenge. Recent studies showed that transforming growth factor‐β3 (TGF‐β3) may be the key factor to reducing adhesion formation in skin or tendon. In this study, we designed a novel type of tissue engineering synovial sheath containing TGF‐β3, to prevent flexor tendon adhesion. First, to achieve a stable release of TGF‐β3, chitosan microspheres, prepared by crosslinking‐emulsion, were used for the delivery of TGF‐β3. Second, a three‐dimensional chitosan scaffold was prepared by lyophilization, and TGF‐β3 microspheres were carefully introduced into the scaffold. Then, synovial cells were cultured and then seeded into the TGF‐β3 loaded scaffold to produce TGF‐β3 controlled‐released tissue engineering synovial sheath. Tests clearly demonstrated that the scaffold has good structure and compatibility with cells. These results expand the feasibility of combinative strategies of controlled protein release and tissue‐engineered synovial sheath formation. Application of this scaffold to tendon repair sites may help to prevent adhesion of tendon healing. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 801–807, 2014.
Effects of VEGF‐loaded chitosan coatings
Authors: Leedy Megan R. , Jennings Jessica A. , Haggard Warren O. , Bumgardner Joel D.
Published: April 2013

Vascular endothelial growth factor (VEGF) is a powerful growth factor that promotes vascularization as well as osteoblastic differentiation and bone regeneration, all of which are key processes in the osseointegration of dental implants. Strategies to increase vascularization through delivery of VEGF may improve osseointegration, especially in patients with reduced bone healing potential. The aim of this study was to determine the potential of chitosan coatings on titanium to deliver VEGF and to support growth and matrix production of osteoblastic cells in vitro. Chitosan was chemically bonded to titanium coupons via silane‐glutaraldehyde linker molecules and loaded with 0, 20, 50, or 100 ng of VEGF. Protein was released during a three day period with around 75% of VEGF (4.44, 11.37, and 22.10 ng/mL/cm2 from the 20, 50, and 100 ng loaded levels, respectively) released during the first 12 h, and 90–95% of the VEGF released from the coatings by day 3. Saos‐2 bone cells continued to proliferate over the 28‐day period on the VEGF‐loaded chitosan coatings in contrast to cells seeded on uncoated titanium, which plateaued after 14 days. Cells on uncoated titanium exhibited a peak in alkaline phosphatase expression at approximately 14 days, concomitant with the plateau in growth. While osteoblast‐like cells on all chitosan coatings exhibited up to a 2‐fold enhancement of the alkaline phosphatase activity and 10‐fold increase in calcium deposition compared to uncoated controls, the incorporation of VEGF into the coatings did not enhance osteoblast matrix production over plain chitosan coatings throughout this study. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 752–759, 2014.
Evaluation of in vitro and in vivo osteogenic differentiation of nano‐hydroxyapatite/chitosan/poly(lactide‐co‐glycolide) scaffolds with human umbilical cord mesenchymal stem cells
Authors: Wang Fei , Zhang Yin‐Cheng , Zhou Hong , Guo Yu‐Cheng , Su Xiao‐Xia
Published: April 2013

We aimed to evaluate the feasibility of the application of the nano‐hydroxyapatite/chitosan/poly(lactide‐co‐glycolide) (nHA/CS/PLGA) scaffold seeded with human umbilical cord mesenchymal stem cells (hUCMSCs) in bone tissue engineering. We prepared the nHA/CS/PLGA, nHA/PLGA, CS/PLGA, and PLGA scaffolds, and tested their mechanical strength. We analyzed the surface antigen markers of hUCMSCs to determine their capability to differentiate into osteoblasts, chondrocytes, and adipocytes. The growth of hUCMSCs on the four types of scaffold was assayed using the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay (MTT assay) and observed using scanning electron microscopy (SEM). Quantitative analysis of alkaline phosphatase (ALP) activity and osteocalcin (OCN) content, as well as the semi‐quantitative reverse transcription‐polymerase chain reaction (RT‐PCR) was performed. After 21 days, the subcutaneous implantations of the scaffolds samples seeded with hUCMSCs into nude mice were analyzed using immunohistochemical staining. The results showed that the mechanical strength of the nHA/CS/PLGA scaffold was enhanced. Furthermore, the nHA/CS/PLGA scaffolds were the most suitable for the adhesion, proliferation, and osteogenic differentiation of hUCMSCs in vitro and nude mouse subcutaneous implantation. The enhanced osteogenic inductivity of the nHA/CS/PLGA scaffolds for hUCMSCs might result from the addition of nHA and CS. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 760–768, 2014.
Normal human embryonic stem cell lines were derived from microsurgical enucleated tripronuclear zygotes
Authors: Jiang Chunyan , Cai Lingbo , Huang Boxian , Dong Juan , Chen Aiqin , Ning Song , Cui Yugui , Qin Lianju , Liu Jiayin
Published: April 2013

A normal fertilized human zygote contains two pronuclei, but zygotes may also display one, three, or even more pronuclei resulting from irregular insemination or meiotic division. Today diploid and triploid human embryonic stem cell (hESC) lines have been derived from tripronuclear (3PN) triploid zygotes, and an in‐vitro fertilization (IVF) baby was born from a rescued diploid zygote by removing the extra male pronucleus of the 3PN zygote. However, whether hESCs can be derived from a rescued 3PN zygote is still unknown. Here, by microsurgical pronuclear removal, we restored 61 diploid zygotes from 3PN zygotes donated by 35 couples, and 11 blastocysts developed with a blastocyst rate of 18.0%, which seems higher than that of nonrescued 3PN zygotes according to previous reports. After the whole zona pellucida free embryos were plated onto feeder cells to grow and passage, 2 hESC lines (CCRM‐hESC‐22 and CCRM‐hESC‐23) were generated and both carried normal karyotype (46, XY). The hESC lines were then characterized by morphology, expansion in vitro, and expression of specific markers of alkaline phosphatase, OCT4, SSEA4, TRA‐1‐60 and TRA‐1‐81. Furthermore, the pluripotency of these 2 hESC lines was confirmed by in vitro embryoid body formation and in vivo teratoma production. Our study indicates that depronucleared 3PN zygotes can improve the blastocysts formation rate, and normal hESC lines can be derived from those corrected 2PN embryos. Based on their multi‐directional differentiation potential in vitro, the established hESC lines could be applied to the developmental risk assessment for IVF babies born from restored zygotes. J. Cell. Biochem. 114: 2016–2023, 2013. © 2013 Wiley Periodicals, Inc.
Evaluation of left anterior descending coronary artery stenosis severity from myocardial end‐diastolic wall stress estimated by tissue‐Doppler imaging
Authors: Moladoust Hassan , Mokhtari‐Dizaji Manijhe , Ojaghi‐Haghighi Zahra
Published: April 2013

Purpose

To identify patients with significant coronary artery disease by the noninvasive quantification of myocardial wall stress in diastole.

Methods

We studied 60 male subjects in sinus rhythm with significant (n = 30) or moderate (n = 30) proximal left anterior descending coronary artery stenosis, and 30 healthy subjects (control group). The average end‐diastolic wall stress was estimated at left ventricle anterior and interventricular septum wall segments from regional wall thickness, meridional and circumferential regional radii of curvature, and noninvasively estimated left ventricular end‐diastolic pressure.

Results

There were significant differences in left ventricular end‐diastolic pressure between patients and controls (p < 0.05). End‐diastolic myocardial wall stress was significantly different between patients with significant and moderate coronary stenosis and healthy subjects in all anterior and septal wall segments (p < 0.05) except for the anterior wall at mid level. The receiver‐operating characteristic curves showed that septum apex wall stress has the highest discriminatory power for predicting significant stenosis versus healthy coronary artery with 83% area under the curve.

Conclusions

Estimated end‐diastolic myocardial wall stress may help in evaluating regional myocardial dysfunction due to coronary artery disease. © 2013 Wiley Periodicals, Inc. J Clin Ultrasound, 41:297–304, 2013
Demonstration of an occult biliary‐arterial fistula using percutaneous contrast‐enhanced ultrasound cholangiography in a transplanted liver
Authors: Daneshi Mohammad , Rajayogeswaran Brathaban , Peddu Praveen , Sidhu Paul S.
Published: April 2013

We present a case of a biliary‐arterial communication as a consequence of the placement of an internal‐external biliary drainage catheter in a liver transplant patient diagnosed on contrast‐enhanced ultrasound using a novel application by injecting microbubble contrast into the catheter tube. We postulate that this method may be sensitive in identifying occult communications between the biliary tree and the vascular compartment when a catheter drain is positioned, and there is hemobilia or unexplained sepsis. © 2013 Wiley Periodicals, Inc. J Clin Ultrasound 42:108–111, 2014
Structural Characterization of a Benzoxazinophenoxazine Formed as a By‐Product During the Synthesis of a 3‐Amino‐N,N‐dimethylsalicylamide
Authors: Zhong Wendy , Yang Jiong , Hilton Bruce D. , Feng Wenqing , Martin Gary E. , Yin Jianguo , Muppalla Kiran , Tong Weidong , Fu Xiaoyong
Published: April 2013

Several highly colored by‐products were observed chromatographically during the synthesis of 3‐amino‐N,N‐dimethylsalicylamide. One of these, an oxidative dimerization products, bis‐(N,N‐dimethylcarboxamido)‐aminophenoxazinone, was previously isolated and characterized. A tris‐(N,N‐dimethylcarboxamido)‐benzoxazino[3,2‐b]phenoxazine, presumably a higher oxidation or further reaction product of the previously isolated and characterized 2‐amino‐3H‐phenoxazin‐3‐one, has also been isolated and characterized by mass spectrometry and multinuclear NMR methods. We now wish to communicate the results of that structure characterization effort.
Physicochemical surface properties of Cupriavidus metallidurans CH34 and Pseudomonas putida mt2 under cadmium stress
Authors: Shamim Saba , Rehman Abdul
Published: April 2013

Cupriavidus metallidurans CH34 and Pseudomonas putida mt2 were used as cadmium (Cd) resistant and sensitive bacteria, respectively to study the effect of Cd on physicochemical surface properties which include the study of surface charge and hydrophobicity which are subjected to vary under stress conditions. In this research work, effective concentration 50 (EC50) was calculated to exclude the doubt that dead cells were also responding and used as reference point to study the changes in cell surface properties in the presence of Cd. EC50 of C. metallidurans CH34 was found to be 2.5 and 0.25 mM for P. putida mt2. The zeta potential analysis showed that CH34 cells were slightly less unstable than mt2 cells as CH34 cells exhibited −8.5 mV more negative potential than mt2 cells in the presence of Cd in growth medium. Cd made P. putida mt2 surface to behave as intermediate hydrophilic (θw = 25.32°) while C. metallidurans CH34 as hydrophobic (θw = 57.26°) at their respective EC50. Although belonging to the same gram‐negative group, both bacteria behaved differently in terms of changes in membrane fluidity. Expression of trans fatty acids was observed in mt2 strain (0.45%) but not in CH34 strain (0%). Similarly, cyclopropane fatty acids were observed more in mt2 strain (0.06–0.14%) but less in CH34 strain (0.01–0.02%). Degree of saturation of fatty acids decreased in P. putida mt2 (36.8–33.75%) while increased in C. metallidurans CH34 (35.6–39.3%). Homeoviscous adaptation is a survival strategy in harsh environments which includes expression of trans fatty acids and cyclo fatty acids in addition to altered degree of saturation. Different bacteria show different approaches to homeoviscous adaptation.
A comparison of global marine surface‐specific humidity datasets from in situ observations and atmospheric reanalysis
Authors: Kent Elizabeth C. , Berry David I. , Prytherch John , Roberts J. Brent
Published: April 2013

The accurate estimation of near‐surface marine‐specific humidity is necessary for climate and air–sea interaction applications. Available estimates of monthly mean‐specific humidity spanning the past 50‐years are based on a variety of sources including in situ observations, atmospheric reanalyses and datasets that blend many different data sources. Eight specific humidity datasets are compared and little consensus emerges as to mean values, regional variations and changes over time. For large area averages the datasets do show consistency in their interannual variations and, in the Extratropics, in their seasonal cycles. Adjustments applied to in situ observations from ships are shown to be smaller than differences among the datasets and in well‐sampled regions and periods the in situ data are able to highlight biases in the reanalysis‐based specific humidity estimates. Near surface‐specific humidity estimates from two recent atmospheric reanalysis projects show markedly different responses in Tropical‐specific humidity to the assimilation of satellite radiance measurements that became available in 1999. There is less confidence in reanalysis‐based estimates of specific humidity over the ocean than over land. However the in situ‐based humidity analyses have suffered in recent years with a reduction in observation numbers and lack of information on observation methods and heights. Consequently near‐surface‐specific humidity remains relatively poorly known over the oceans.
Comparison of UV index from Ozone Monitoring Instrument (OMI) with multi‐channel filter radiometers at four sites in the tropics: effects of aerosols and clouds
Authors: Janjai S. , Wisitsirikun S. , Buntoung S. , Pattarapanitchai S. , Wattan R. , Masiri I. , Bhattarai B. K.
Published: April 2013

The solar ultraviolet (UV) index from Ozone Monitoring Instrument (OMI) onboard NASA EOS/Aura satellite is compared with that derived from ground‐based multi‐channel filter radiometers at four sites in the tropical environment of Thailand. The sites include Chiang Mai (18.78°N, 98.98°E), Ubon Ratchathani (15.25°N, 104.87°E), Nakhon Pathom (13.82°N, 100.04°E) and Songkhla (7.2°N, 100.6°E). At these sites, aerosol optical depth is monitored using sunphotometers and cloud images are taken by sky cameras. The comparison results clearly show the overestimation of OMI UV index because of influences by aerosols and clouds. The differences between the two datasets lie between 38.1 and 60.7% for all sky conditions, and reduce to 22.5–50.3% for clear sky conditions.
Assessment of phonomicrosurgical training in otolaryngology residencies: A resident survey
Authors: Shah Manish D. , Johns Michael M. , Statham Melissa , Klein Adam M.
Published: April 2013

Objectives/Hypothesis

The primary objective of this study is to assess the adequacy of clinical and laboratory‐based phonomicrosurgical training in otolaryngology residency programs using a self‐report survey. The study aims to establish whether there is a need and desire for focused surgical training in phonomicrosurgery.

Study Design

Self‐report Internet‐based questionnaire.

Methods

An anonymous survey was sent to all current residents in otolaryngology training programs in the United States and Canada. For portions of the analysis, the residents were categorized into two groups—junior (R2 and R3) and senior (R4 and R5).

Results

One hundred ninety‐one residents responded to the survey (USA: 166; Canada: 25), representing a 34.3% response rate. Approximately one‐half of residents stated that their residency program includes a rotation during which the main emphasis is laryngology. Only 18.8% of residents were “very” satisfied with the phonomicrosurgery experience that their program offers and 21.6% of senior residents felt “very” comfortable performing a phonomicrosurgical removal of a vocal fold lesion. Whereas the vast majority of respondents found temporal bone laboratory training to be helpful, 82% had never performed laboratory training in phonomicrosurgery. The majority (87.4%) felt that their comfort level with phonomicrosurgery would increase if they had access to laboratory‐based training.

Conclusion

Our study suggests that there is a lack of emphasis on clinical and laboratory‐based training in phonomicrosurgery and that there is a need and desire for focused surgical training in phonomicrosurgery.

Level of Evidence

Level 4.
Testing Infrared Laser Phototherapy (810 nm) to Ameliorate Diabetes: Irradiation on Body Parts of Diabetic Mice
Authors: Peplow Philip V. , Baxter G. David
Published: April 2013

Background and Objectives

Irradiation of left flank of genetic diabetic mice with 660 nm wavelength laser, 100 mW, 20 seconds/day for 7 days did not significantly alter blood plasma glucose compared to nonirradiated controls. Infrared light would provide for a greater amount of photoenergy penetrating the skin and muscle. Genetic diabetic mice were irradiated with 810 nm wavelength laser to test for antidiabetic effect.

Materials and Methods

Sixty‐five diabetic mice were used. Body weight and water intake of mice were measured daily for 7 days prior to start of treatment (Day 0). Mice were irradiated with 810 nm wavelength laser, 50 mW, 40 seconds/day, 7 days on left flank (n = 11), mid‐upper abdomen (n = 14), or left inguinal region (n = 14); some mice were not irradiated (control, n = 26). Body weight and water intake of mice were measured to Day 7. On Day 7, mice were fasted for 4 hours, anesthetized with sodium pentobarbitone (s.c.) and blood collected by cardiac puncture into EDTA‐treated tubes. Blood plasma was assayed for glucose and fructosamine. Blood was collected and assayed from nonirradiated nondiabetic mice (n = 12).

Results

On Day 7 body weight was significantly lower and water intake significantly higher compared to Day 0 for diabetic mice irradiated on left flank (40.7 ± 0.5 vs. 42.2 ± 0.4 g, 28.2 ± 1.5 vs. 23.4 ± 1.5 g, respectively); there was no significant change for diabetic mice irradiated on mid‐upper abdomen or left inguinal region and also for nonirradiated diabetic mice. On Day 7 blood plasma glucose levels for irradiated diabetic mice were not significantly different to nonirradiated diabetic mice. Blood plasma fructosamine level of diabetic mice irradiated on left inguinal region was significantly lower than for nonirradiated diabetic mice (312 ± 6 vs. 377 ± 15 µmol/L); for diabetic mice irradiated on left flank or mid‐upper abdomen (362 ± 22, 357 ± 19 µmol/L) it was not significantly different to nonirradiated diabetic mice.

Conclusion

Irradiation of left inguinal region in diabetic mice with 810 nm laser has potential to ameliorate diabetes as shown by decreased blood plasma fructosamine. Lasers Surg. Med. 9999:XX–XX, 2013. © 2013 Wiley Periodicals, Inc.
Redox‐ and Glucose‐Induced Shape‐Memory Polymers
Authors: Dong Zhen‐Qiang , Cao Ya , Yuan Qi‐Juan , Wang Yi‐Fu , Li Jian‐Hu , Li Bang‐Jing , Zhang Sheng
Published: April 2013

A novel redox‐induced shape‐memory polymer (SMP) is prepared by crosslinking β‐cyclodextrin modified chitosan (β‐CD‐CS) and ferrocene modified branched ethylene imine polymer (Fc‐PEI). The resulting β‐CD‐CS/Fc‐PEI contains two crosslinks: reversible redox‐sensitive β‐CD‐Fc inclusion complexes serving as reversible phases, and covalent crosslinks serving as fixing phases. It is shown that this material can be processed into temporary shapes as needed in the reduced state and recovers its initial shape after oxidation. The recovery ratio and the fixity ratio are both above 70%. Furthermore, after entrapping glucose oxidase (GOD) in the system, the material shows a shape memory effect in response to glucose. The recovery ratio and the fixity ratio are also above 70%.

magnified image
High‐resolution mouse kidney perfusion imaging by pseudo‐continuous arterial spin labeling at 11.75T
Authors: Duhamel Guillaume , Prevost Valentin , Girard Olivier M. , Callot Virginie , Cozzone Patrick J.
Published: April 2013

Purpose

Quantitative measure of blood flow provides important information regarding renal function, nephropathies and viability of kidney transplantation. Therefore, a method that would allow quantitative and reliable assessment of the renal microvascular perfusion would be very valuable. Arterial spin labeling Magnetic Resonance Imaging has started to be widely used for human studies. For rodents though, despite the increasing number of transgenic mouse models, renal perfusion Magnetic Resonance Imaging has been only sparsely reported. This study investigated the use of FAIR (flow‐sensitive alternating inversion recovery) and pseudo‐continuous arterial spin labeling (pCASL) for mouse renal blood flow measurements.

Methods

FAIR and pCASL were compared in terms of sensitivity, absolute quantification, reproducibility and flexibility of implementation. Multislice and coronal imaging were also investigated. Studies were performed at 11.75 T with volumic transmitter/receiver radiofrequency coils and fast imaging.

Results

pCASL demonstrated better experimental flexibility and higher sensitivity compared to FAIR (> +20%). Renal blood flow values in the range of 550–750 mL/100 g/min for the cortex and of 140–230 mL/100 g/min for the medulla, consistent with literature data, were measured.

Conclusion

pCASL was successfully applied at very high field for mouse renal blood flow measurements, demonstrating high sensitivity, flexibility and multislice imaging capability. pCASL may be considered as a method of choice for mouse kidney perfusion studies. Magn Reson Med 71:1186–1196, 2014. © 2013 Wiley Periodicals, Inc.
Vessel‐specific quantification of blood oxygenation with T2‐relaxation‐under‐phase‐contrast MRI
Authors: Krishnamurthy Lisa C. , Liu Peiying , Ge Yulin , Lu Hanzhang
Published: April 2013

Purpose

Measurement of venous oxygenation (Yv) is a critical step toward quantitative assessment of brain oxygen metabolism, a key index in many brain disorders. The present study aims to develop a noninvasive, rapid, and reproducible method to measureYvin a vessel‐specific manner.

Theory

The method,T2‐Relaxation‐Under‐Phase‐Contrast MRI, utilizes complex subtraction of phase‐contrast to isolate pure blood signal, applies nonslice‐selectiveT2‐preparation to measureT2, and convertsT2to oxygenation using a calibration plot.

Methods

Following feasibility demonstration, several technical aspects were examined, including validation with an established globalYvtechnique, test–retest reproducibility, sensitivity to detect oxygenation changes due to hypoxia and caffeine challenges, applicability of echo‐planar‐imaging (EPI) acquisition to shorten scan duration, and ability to study veins with a caliber of 1–2 mm.

Results

T2‐Relaxation‐Under‐Phase‐Contrast was able to simultaneously measureYvin all major veins in the brain, including sagittal sinus, straight sinus, great vein, and internal cerebral vein.T2‐Relaxation‐Under‐Phase‐Contrast results showed an excellent agreement with the reference technique, high sensitivity to oxygenation changes, and test–retest variability of 3.5 ± 1.0%. The use of segmented‐EPI was able to reduce the scan duration to 1.5 minutes. It was also feasible to study pial veins and deep veins.

Conclusion

T2‐Relaxation‐Under‐Phase‐Contrast MRI is a promising technique for vessel‐specific oxygenation measurement.Magn Reson Med 71:978–989, 2014. © 2013 Wiley Periodicals, Inc.