bluuebunny/crossref_metadata_2025 huggingface dataset:
Adenosine Reagentless Electrochemical Aptasensor Using a Phosphorothioate Immobilization Strategy
Authors: Ceretti Helena , Ponce Belén , Ramírez Silvana A. , Montserrat Javier M.
Published: October 2009

This work deals with the characterization of a phosphorothioate anchoring strategy for aptamer molecules linked to gold, in the context of electrochemical sensors, using adenosine aptamer as model system. Surface density of immobilized phosphorothioate oligonucleotide sequences has been explored for a range of oligonucleotide concentrations (0.055–55 μM), finding a consequent variation of molecular surface density (3.5×1011–2.8×1013 molecules/cm2). Most suitable aptamer concentration for adenosine recognition was also explored and found to be around 5.5 μM. As proof of concept of phosphorothioate strategy, electrochemical response to adenosine concentration was measured using a ferrocene‐labeled oligonucleotide sequence, and phosphorothioate anchoring thermal stability was compared to thiol immobilization.
Etched succinate‐functionalized silica hydride stationary phase for open‐tubular CEC
Authors: Chen Jian‐Lian
Published: October 2009

An open‐tubular (OT) CEC column was designed to anchor ionizable succinate‐functionalized ligands onto a silica hydride‐based stationary phase through surface etching, silanization, and hydrosilation reactions beginning from a bare fused‐silica tube. The modified columns that were produced in each step were monitored by analysis of the effect of performance of EOF on the changes of pH values, concentrations, and the amount of ACN added in the running buffers. By tracking the EOF patterns between columns, the author determined that the surface composition of the final product column was a combination of silanols, silica hydrides, and succinate ligands. Furthermore, lower loading volumes of the succinate ligands prepared for the hydrosilation reaction served to complete the mixed‐mode OT‐CEC columns, and subsequently to carry out the separation of six phenyl alcohols. Studies on the elution order of these alcohols identified the presence of chromatographic interactions in addition to electrophoresis. Based on the employment of a solvation parameter model, these interactions likely included dispersion interactions, dipole‐type interactions, and interactions arising through the polarizable electrons in the solute. The optimum buffer conditions for CEC separations of phenyl alcohols, carbonyl‐substituted phenols, and a mixture of nucleosides and thymine were a phosphate buffer (50 mM, pH 10.51), a borate buffer (50 mM, pH 8.62), and a borate buffer (50 mM, pH 9.50), respectively. Overall, the hydride‐based stationary phases with ionizable ligands were successfully applied to the OT‐CEC separations, and these results confidently propose an ideal route to the synthesis of novel OT‐CEC columns.
Cellulose dimethylphenylcarbamate‐immobilized zirconia for chiral separation in reversed‐phase CEC
Authors: Gwon Jurim , Jin Juhyeon , McNeff Clayton V. , Park Jung Hag
Published: October 2009

Cellulose dimethylphenylcarbamate (CDMPC)‐immobilized zirconia (CDMPCZ) was used as a chiral stationary phase for enantioseparation of a set of nine racemic compounds in reversed‐phase CEC. Influences of the type and composition of organic modifier and the applied voltage on enantioseparation were examined. Separation data on CDMPCZ were also compared with those on CDMPC‐immobilized silica (CDMPCS). Enantiomers of the analytes investigated are well separated in ACN/phosphate buffer mobile phases. Better enantioselectivity and resolution were obtained with ACN than MeOH as the organic modifier. Retention was longer but better enantioselectivity and resolution were obtained on CDMPCZ than CDMPCS.
Determination of related substances of levodopa including the R‐enantiomer by CE
Authors: Wongwan Sudaporn , Hammitzsch‐Wiedemann Manuela , Scriba Gerhard K. E.
Published: October 2009

A CE assay for the simultaneous determination of the impurities of levodopa listed in the European Pharmacopoeia including the (R)‐enantiomer was developed and validated. The analysis was performed in a fused‐silica capillary employing sulfated β‐cyclodextrin as chiral selector at an applied voltage of 20 kV and a temperature of 18°C. The optimized background electrolyte consisted of 0.1 M sodium phosphate buffer, pH 2.0, containing 6 mg/mL sulfated β‐cyclodextrin. L‐phenylalanine was used as the internal standard. The assay was validated in the range of 0.1–1.0% for the impurities at a concentration of levodopa of 2 mg/mL. The effect of different batches of sulfated β‐cyclodextrin was investigated using levodopa and L‐tyrosine as critical pair. The method was applied to determine the purity of several samples of levodopa including the chemical reference substance of the European Pharmacopoeia.
Determination of residual cell culture media components by MEKC
Authors: Zhang Junge , Chakraborty Utpal , Foley Joe P.
Published: October 2009

Folic acid, hypoxanthine, mycophenolic acid, nicotinic acid, riboflavin, and xanthine are widely used as cell culture media components in monoclonal antibody manufacturing. These components are subsequently removed during the downstream purification processes. This article describes a single MEKC method that can simultaneously determine all the listed compounds with acceptable LOD and LOQ. All the analytes were successfully separated by MEKC using running buffer containing 40 mM SDS, 20 mM sodium phosphate, and 20 mM sodium borate at pH 9.0. The MEKC method was compared to the corresponding CZE method using the same running buffer containing no SDS. The effect of SDS concentration on separation, the pH of the running buffer, and the detection wavelength were studied and optimal MEKC conditions were established. Good linearity was obtained with correlation coefficients of more than 0.99 for all analytes. Specificity, accuracy, and precision were also evaluated. The recovery was in the range of 89–112%. The precision results were in the range of 1.7–4.8%. The experimentally determined data demonstrated that the MEKC method is applicable to the determination of the six analytes in in‐process samples from monoclonal antibody manufacturing processes.
Estimating seepage and hydraulic potentials near incised ditches in a homogeneous, isotropic aquifer
Authors: Römkens M. J. M.
Published: October 2009

Soil erosion on upland areas is a highly complex phenomenon involving many component processes. One of the least explored processes is the role of subsurface flow. Rain or irrigation water entering the soil profile either accrues to groundwater or exits at some point downslope as seepage. In the latter case, the positive water pressure may lead to detachment of soil particles, aggregates, or bulk soil, that often is a prelude to incipient rilling or gullying. This article concerns the analysis of seepage to ditches with a water level lower than the adjacent field water table and the hydraulic pressures near the ditches in order to assess their contributing role in gully development. The approach taken is to analyze the subsurface flow regime under steady‐state conditions using the theory of conformal transformations. First, seepage to a fully filled circular drain in a homogeneous isotropic layer overlaying an impermeable layer was analyzed. Subsequently, the case of drainage to a ditch partially filled with water and the effect of a buffer strip adjacent to the ditch on seepage reduction were studied using the same methodology. Two approaches were considered to approximate the water level in the buffer strip: (1) a confined boundary represented by a straight line between the ditch water level and the field surface water level; and (2) a free boundary in which the groundwater level was approximated by the pressure potential relationship for flow from a ponded surface area to a sink placed at the surface at a distance equal to the width of the buffer strip. The latter analysis yielded explicit expressions of seepage, and the groundwater hydraulic and stream potential functions in terms of the spatial coordinates. This relationship should facilitate the analysis of the role of the subsurface water regime on seepage, soil erosion, and gully development. Published in 2009 by John Wiley & Sons, Ltd.
Alluvial gully erosion: an example from the Mitchell fluvial megafan, Queensland, Australia
Authors: Brooks A. P. , Shellberg J. G. , Knight J. , Spencer J.
Published: October 2009

Considerable attention has been focused on the role of gullies as a contributor to contemporary sediment loads of rivers in Australia. In southern Australia rapid acceleration of hillslope gully erosion has been widely documented in the post‐European period (∼ last 200 years). In the northern Australian tropics, however, gully erosion processes operating along alluvial plains have not been well documented and can differ substantially from those gullies eroding into colluvium on hillslopes. Aerial reconnaissance surveys in 2004 along 13 500 km of the main stem rivers that drain into the Gulf of Carpentaria (GoC), identified extensive areas of alluvial lands that have been impacted by a pervasive form of gully erosion. More detailed remote sensing based mapping within the 31 000 km2 Mitchell River fluvial megafan has identified that active gullying into alluvium occupies ∼ 0·4% (129 km2) of the lower Mitchell catchment. These alluvial gullies are concentrated along main drainage channels and their scarp heights are highly correlated to the local relief between the floodplain and river thalweg. While river incision into the megafan since the Pleistocene has developed the relief potential for erosion, other factors such as floodplain hydrology, soil dispersibility, and vegetation also influence the distribution of gullies. In this paper we present a conceptual model of alluvial gullies, and contend that they represent a distinct end member in the continuum of gully forms that have been described in the geomorphic literature. An understanding of the processes driving this form of alluvial gullying can only be gained when they are differentiated from widely described colluvial hillslope gully models and theories. We present evidence of type examples of alluvial gullying in the Mitchell, and through analysis of their distribution and morphology at different scales, highlight some of the key mechanisms that are potentially initiating these features and driving their expansion. Copyright © 2009 John Wiley & Sons, Ltd.
Androgen‐regulated gastrin‐releasing peptide receptor expression in androgen‐dependent human prostate tumor xenografts
Authors: Schroeder Rogier P.J. , de Visser Monique , van Weerden Wytske M. , de Ridder Corrina M.A. , Reneman Suzanne , Melis Marleen , Breeman Wout A.P. , Krenning Eric P. , de Jong Marion
Published: October 2009

Human prostate cancer (PC) overexpresses the gastrin‐releasing peptide receptor (GRPR). Radiolabeled GRPR‐targeting analogs of bombesin (BN) have successfully been introduced as potential tracers for visualization and treatment of GRPR‐overexpressing tumors. A previous study showed GRPR‐mediated binding of radiolabeled BN analogs in androgen‐dependent but not in androgen‐independent xenografts representing the more advanced stages of PC. We have further investigated the effect of androgen modulation on GRPR‐expression in three androgen‐dependent human PC‐bearing xenografts: PC295, PC310 and PC82 using the androgen‐independent PC3‐model as a reference. Effects of androgen regulation on GRPR expression were initially studied on tumors obtained from our biorepository of xenograft tissues performing reverse transcriptase polymerase chain reaction (RT‐PCR) and autoradiography (125I‐universal‐BN). A prospective biodistribution study (111In‐MP2653) and subsequent autoradiography (125I‐GRP and 111In‐MP2248) was than performed in castrated and testosterone resupplemented tumor‐bearing mice. For all androgen‐dependent xenografts, tumor uptake and binding decreased drastically after 7 days of castration. Resupplementation of testosterone to castrated animals restored GRPR expression extensively. Similar findings were concluded from the initial autoradiography and RT‐PCR studies. Results from RT‐PCR, for which human specific primers are used, indicate that variations in GRPR expression can be ascribed to mRNA downregulation and not to castration‐induced reduction in the epithelial fraction of the xenograft tumor tissue. In conclusion, expression of human GRPR in androgen‐dependent PC xenografts is reduced by androgen ablation and is reversed by restoring the hormonal status of the animals. This knowledge suggests that hormonal therapy may affect GRPR expression in PC tissue making GRPR‐based imaging and therapy especially suitable for non‐hormonally treated PC patients.
Expression of estrogen receptor alpha increases leptin‐induced STAT3 activity in breast cancer cells
Authors: Binai Nadine A. , Damert Annette , Carra Gert , Steckelbroeck Stephan , Löwer Johannes , Löwer Roswitha , Wessler Silja
Published: October 2009

Adipositas correlates with an enhanced risk of developing malignant diseases such as breast cancer, endometrial tumor or prostate carcinoma, but the molecular basis for this is not well understood. Potential mechanisms include increased bioavailability of adipocytokines (e.g. leptin) and steroid hormones. Here, we investigated cross‐talk between ERα (estrogen receptor alpha) and leptin‐induced activation of signal transducer and activator of transcription 3 (STAT3), a transactivator of important oncogenes. Upon leptin binding to its receptor Ob‐RL (obesity receptor), STAT3 tyrosine phosphorylation and transactivation activity were enhanced by simultaneously expressing ERα. Downregulation of ERα using small interfering RNA abolished leptin‐induced STAT3 phosphorylation. Interestingly, leptin‐mediated STAT3 activation was unaffected by co‐stimulation with the ERα ligands estradiol (E2) or estrogen antagonists ICI182,780 and tamoxifen, implying that enhancement of leptin‐mediated STAT3 activity is independent of ERα ligands. We also detected ERα binding to STAT3 and JAK2 (Janus kinase 2), resulting in enhanced JAK2 activity upstream of STAT3 in response to leptin that might lead to an increased ERα‐dependent cell viability. Altogether, our results indicate that leptin‐induced STAT3 activation acts as a key event in ERα‐dependent development of malignant diseases.
The anticancer effect of probiotic Bacillus polyfermenticus on human colon cancer cells is mediated through ErbB2 and ErbB3 inhibition
Authors: Ma Elise L. , Choi Yoon Jeong , Choi Jinyoung , Pothoulakis Charalabos , Rhee Sang Hoon , Im Eunok
Published: October 2009

A wealth of data implicates that ErbB receptors have essential roles in tumor development. Probiotic bacteria are known to exert an anticancer activity in animal studies. Bacillus polyfermenticus (B.P.), a probiotic bacterium, has been clinically used for a variety of gastrointestinal disorders in East Asia. Here, we investigated the effect of B.P. on the growth of tumors and its putative mechanism of actions. Conditioned medium of B.P. cultures (B.P. CM) inhibited the growth of human colon cancer cells including HT‐29, DLD‐1 and Caco‐2 cells. Moreover, B.P. CM suppressed colony formation of HT‐29 cells cultured on soft agar and reduced carcinogen‐induced colony formation of normal colonocytes. Furthermore, data from the mouse xenograft model of human colon cancer cells showed reduced tumor size in B.P. CM‐injected mice when compared to E. coli conditioned medium‐injected mice. Exposure of B.P. CM to HT‐29 cells for 24 hr, 48 hr and 2 weeks reduced ErbB2 and ErbB3 protein expression as well as mRNA levels. Moreover, cyclin D1 expression that is required for ErbB‐dependent cell transformation was decreased by B.P. CM. Furthermore, transcription factor E2F‐1 that regulates cyclin D1 expression was also decreased by B.P. CM. These results show that B.P. inhibits tumor growth and its anticancer activity occurs, at least in part, through suppressing ErbB2 and ErbB3. Taken together, our study suggests that this probiotic may be clinically used as a prophylactic treatment to prevent colon cancer development.
Risk factors and survival by HPV‐16 E6 and E7 antibody status in human papillomavirus positive head and neck cancer
Authors: Smith Elaine M. , Pawlita Michael , Rubenstein Linda M. , Haugen Thomas H. , Hamsikova Eva , Turek Lubomir P.
Published: October 2009

High‐risk human papillomavirus types (HPV‐HR) are associated with head and neck cancer (HNC) risk and better survival. Most patients with HPV‐HR DNA‐positive tumors develop anti‐HPV E6/E7 antibodies; however, it is unclear whether those who mount an immune response have similar risk factors or clinical outcomes as those who do not. HPV‐16 DNA tumor‐positive HNC cases were evaluated for HPV‐16 E6 and E7 antibodies using a GST capture ELISA system. Among 57 HPV‐16 DNA tumor‐positive HNC cases, 67% were detected with HPV‐16 E6 and/or E7 antibodies. Male gender (76% vs. 42%, p = 0.02), younger age (63% vs. 16%, p = 0.001) but not tobacco or alcohol were associated with E6 and/or E7 seropositivity. Seropositivity was associated more often with late stage (76%), poor grade (65%), positive nodes (82%). and in the oropharynx (82%), Median disease‐specific and recurrence‐free survival were longer in E6 and/or E7 seropositive compared to E6/E7‐negative cases (2.2 years vs. 1.4 years, both outcomes), although results were not statistically significant. When examined jointly with p16 expression, E6 and/or E7‐positive/p16‐positive cases had better disease‐specific (2.1 years vs. 1.1 years, p = 0.06) and recurrence‐free (2.3 years vs. 1.1 years, p = 0.03) survival compared to E6‐/E7‐/p16‐ cases. These findings suggest there are 2 distinct HNC patient groups with HPV DNA‐positive tumors, distinguishable by E6 and/or E7 antibody status. Differences in antibody status are associated with distinct risk factors and clinical outcomes. This information can be available as a simple blood test at initial presentation, before the removal of tissue through biopsy or surgery.
Controlled release of hepatocyte growth factor from a bovine acellular scaffold for vocal fold reconstruction
Authors: Xu Chet C. , Chan Roger W. , Weinberger Debra G. , Efune Guy , Pawlowski Karen S.
Published: October 2009

A bovine acellular scaffold was found to facilitate tissue remodeling in a rat model of vocal fold injury, whereas hepatocyte growth factor (HGF) has been shown to have an antiscarring effect in the larynx. This study examined the loading and release kinetics of HGF in vitro, and the potential of the acellular scaffold as a timed‐release system for the delivery of HGF in vivo. Bilateral wounds were created in the posterior vocal folds of 20 rats, with HGF‐loaded acellular scaffolds implanted into the wounds unilaterally, and scaffolds without HGF implanted into the contralateral vocal folds as control. The rats were humanely sacrificed after 3, 7, 30, and 90 days and their larynges were examined histologically and immunohistochemically. Expressions of key matrix proteins in the vocal fold coronal sections were quantified by digital image analysis. Results demonstrated a gradual, sustained release of HGF for at least 7 days in vitro, consistent with the detection of glycosaminoglycans inherent of the scaffold. In rat vocal folds implanted with HGF‐loaded scaffolds, apparently fewer inflammatory cells were observed 3 days after surgery when compared to the control. The mean relative densities of collagen III and hyaluronic acid were significantly lower than those of the control 7 days after surgery. Scaffold implants were apparently degraded by 3 months in all animals, with no evidence of fibrosis or calcification. These data suggested that the bovine acellular scaffold could be promising for the exogenous delivery of select growth factors in vivo. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Immunization with a DNA vaccine candidate in chronic hepatitis C patients is safe, well tolerated and does not impair immune response induction after anti‐hepatitis B vaccination
Authors: Castellanos Marlen , Cinza Zurina , Dorta Zaily , Veliz Gloria , Vega Héctor , Lorenzo Irma , Ojeda Sergio , Dueñas‐Carrera Santiago , Alvarez‐Lajonchere Liz , Martínez Gillian , Ferrer Elena , Limonta Miladys , Linares Marbelis , Ruiz Odalis , Acevedo Boris , Torres Dinorah , Márquez Gabriel , Herrera Luis , Arús Enrique
Published: October 2009

Background

In the present study, we evaluated the safety of CIGB‐230, a novel vaccine candidate based on the mixture of a plasmid for DNA immunization, expressing hepatitis C virus (HCV) structural antigens, with a recombinant HCV Core protein.

Methods

Fifteen HCV chronically‐infected volunteers with detectable levels of HCV RNA genotype 1b, who were nonresponders to previous treatment with interferon plus ribavirin, were intramuscularly injected with CIGB‐230 on weeks 0, 4, 8, 12, 16 and 20. Individuals were also immunized at weeks 28, 32 and 36 with a recombinant vaccine against hepatitis B. Adverse events were recorded and analyzed. Blood samples were taken every 4 weeks up to month 12 for hematological, biochemical, virological and immunological analysis.

Results

All patients completed the treatment with CIGB‐230. Adverse events were only slight (83.6%) or moderate (16.4%). No significant differences in hematological and biochemical parameters, including serum aminotransferases, were detected between the baseline and post‐treatment state. Induction of a CD4+ T lymphocyte response against a particular region in HCV E1, spanning amino acids 230–312 in HCV polyprotein, was detected in 42.8% of patients during treatment with CIGB‐230. The ability of T cells to proliferate in response to mitogenic stimulation was not weakened. Most individuals (78.6%) were seroprotected after anti‐hepatitis B vaccination and 42.8% were hyper‐responders (antibody titers > 100 UI/ml). No anti‐mitochondrial, anti‐nuclear and anti‐extractable nuclear antigen antibodies were generated during immunization with CIGB‐230.

Conclusions

Vaccination with CIGB‐230 in HCV chronically‐infected individuals was safe, well tolerated and did not impair the ability to respond to non‐HCV antigens. Copyright © 2009 John Wiley & Sons, Ltd.
The journal Communications in Numerical Methods in Engineering with Biomedical Applications becomes the International Journal for Numerical Methods in Biomedical Engineering (IJNMBE) from 1st January 2010
Authors: Nithiarasu Perumal , Löhner Rainald
Published: October 2009

Communications in Numerical Methods in Engineering, founded by Roland W. Lewis in 1985, will change its title to the ‘International Journal for Numerical Methods in Biomedical Engineering’ and have a revised Aims and Scope. Copyright © 2009 John Wiley & Sons, Ltd.
Trends of precipitation over the Iberian Peninsula and the North Atlantic Oscillation under climate change conditions
Authors: Rodríguez‐Puebla Concepción , Nieto Susana
Published: October 2009

The trends of precipitation over the Iberian Peninsula (IP) and the North Atlantic Oscillation (NAO) index from December to March are compared using observations and model simulations from the Coupled Model Intercomparison Project phase 3 (CMIP3). The evaluation is performed in two multi‐models as derived by averaging simulations corresponding to two experiments: one represents climate in the 20th century (20C3M) and the other the scenario with medium forcing IPCC SRES A1B in the 21st century. The NAO index shows a trend to more positive phases and precipitation tends to decrease in the case of observations, with greater significance in the NAO than in precipitation. The simulations in the 20th century underestimate the trend both in the NAO and in precipitation compared to observations. The multi‐model in the 21st century indicates a change in the NAO regimes to being more positive; this leads to a reduction of precipitation over the IP. To explain the precipitation trend changes we consider the response of precipitation to the NAO, the regression between sea level pressure (SLP) over the Euro‐Atlantic area onto precipitation averaged over the IP and the composite of precipitation for years with greater and lower NAO. Copyright © 2009 Royal Meteorological Society
Interannual variability in the subseasonal northward excursion of the Baiu front
Authors: Tomita Tomohiko , Nonaka Masami , Yamaura Tsuyoshi
Published: October 2009

The Baiu front, a quasi‐stationary front that appears in early boreal summer near the northwestern rim of the subtropical Pacific high, shows interannual variability characterised by polarity changes in precipitation anomalies during the subseasonal northward excursion in the western North Pacific (WNP). These changes are forced by motion over the fixed surface divergence/convergence anomalies in the WNP, which are regulated by the atmospheric bridge or the Pacific–East Asian (PEA) teleconnection. The PEA teleconnection is caused by the tropical sea surface temperature anomalies (SSTAs) associated with the El Niño/Southern Oscillation. The upper ocean mixed layer depth (MLD) is crucial in regulating the SSTAs in the WNP. In the tropical WNP (lower than 20°N), the large MLD (and hence large heat capacity in the upper ocean) can maintain the SSTAs for about half‐a‐year. In the mid‐latitude WNP (higher than 20°N), the development of the seasonal thermocline in early summer reduces the heat capacity, whereas the atmospheric variation modifies the SSTAs within a season. The MLD is regarded as an important parameter that controls the strength and time scale of the air–sea feedback, and the latitude of 20°N approximately separates regions where the oceanic thermal properties are active or passive for the early‐summer atmospheric circulations in the WNP. Copyright © 2009 Royal Meteorological Society
Grazing‐induced alterations of soil hydraulic properties and functions in Inner Mongolia, PR China
Authors: Krümmelbein Julia , Peth Stephan , Zhao Ying , Horn Rainer
Published: October 2009

Increasing grazing intensities of sheep and goats can lead to an increasing degradation of grasslands. We investigated four plots of different grazing intensities (heavily grazed, winter‐grazed, ungrazed since 1999, and ungrazed since 1979) in Inner Mongolia, PR China, in order to study the effects of trampling‐induced mechanical stresses on soil hydraulic properties. Soil water transport and effective evapotranspiration under “heavily grazed” and “ungrazed since 1979” were modeled using the HYDRUS‐1D model. Model calibration was conducted using data collected from field studies. The field data indicate that grazing decreases soil C content and hydrophobicity. Pore volume is reduced, and water‐retention characteristics are modified, the saturated hydraulic conductivity decreases, and its anisotropy (vertical vs. horizontal conductivity) is influenced. Modeling results revealed higher evapotranspiration on the ungrazed site (ungrazed since 1979) compared to the grazed site (heavily grazed) due to wetter soil conditions, more dense vegetation, litter cover, and decreased runoff and drainage, respectively. Grazing modified the partitioning of evapotranspiration with lower transpiration and higher evaporation at the grazed site owing to reduced root water uptake due to reduced evaporation and a patchy soil cover.
Cooperative multimodal retention of IgG, fragments, and aggregates on hydroxyapatite
Authors: Gagnon Pete , Cheung Chia‐Wei , Yazaki Paul J.
Published: October 2009

Retention mapping of chimeric monoclonal IgG1, Fc, Fab, F(ab′)2, and aggregated antibody was conducted on hydroxyapatite (HA) by systematically varying phosphate and chloride concentrations during gradient elution in order to characterize the interactions of each solute with calcium and phosphate residues on the solid phase. Lysozyme was used as a control to model cation exchange‐dominant interactions. Bovine serum albumin was used as a control for calcium affinity‐dominant interactions. Calcium affinity and phosphoryl cation exchange were positively cooperative for IgG‐related species. Fc retention was dominated by calcium affinity, while retention of Fab was dominated by cation exchange. F(ab′)2 exhibited a curve shape similar to Fab, but stronger retention. The retention curve for intact IgG incorporated the distinctive elements of its fragments but stronger retention than that predicted by their addition to one another. Aggregate retention paralleled the curve for non‐aggregated antibody, with stronger retention by both binding mechanisms. Experimental data revealed evidence of charge repulsion between IgG carboxyls and HA phosphate at low conductivity values. Electrostatic repulsion of amino residues and attraction of carboxyls by HA calcium appeared to be blocked by strong complexation of calcium with mobile phase phosphate.
Organic–inorganic hybrid silica as supporting matrices for selective recognition of bovine hemoglobin via covalent immobilization
Authors: Lin Zian , Yang Fan , He Xiwen , Zhang Yukui
Published: October 2009

The synthesis of poly‐aminophenylboronic acid (APBA) imprinted hybrid silica‐based polymers for selective recognition of bovine hemoglobin (BHb) was described, where the mesoporous hybrid silica supporting matrices were prepared by a mild sol–gel process with tetraethoxysilane and 3‐aminopropyltriethoxysilane as two precursors. Covalent immobilization of BHb was adopted in order to create homogeneous recognition sites. After removal of the template, the resulting imprinted polymers showed high binding affinity toward BHb and the imprinting factor (α) reached 2.12. The specificity of the BHb recognition was evaluated with competitive experiments, indicating the imprinted polymers have a higher selectivity for the template BHb. The easy preparation protocol and good protein recognition properties made the approach an attractive solution to depletion of high‐abundance protein from bovine blood.
Characterization of the yerba mate (Ilex paraguariensis) volatile fraction using solid‐phase microextraction‐comprehensive 2‐D GC‐MS
Authors: Purcaro Giorga , Tranchida Peter Q. , Jacques Rosângela Assis , Caramão Elina Bastos , Moret Sabrina , Conte Lanfranco , Dugo Paola , Dugo Giovanni , Mondello Luigi
Published: October 2009

The present research is focused on the use of a solid‐phase microextraction‐comprehensive 2‐D GC methodology, in the analysis of the volatile fraction of yerba mate. Yerba mate is used for the generation of a tea‐like beverage, widely consumed in South America. A rapid‐scanning quadrupole mass spectrometer (qMS), employed as a detection system and operated at a 25 Hz scanning frequency, supplied high‐quality mass spectra. The effectiveness of the 3‐D comprehensive 2‐D GC‐qMS experiment was compared to that of GC‐qMS analysis on the same sample. Peak identification, in both applications, was achieved through MS library matching, with the support of linear retention index data. Apart from a great increase in the number of analytes separated (approx. by a factor of 5) and identified (approx. by a factor of 3.5), the comprehensive 2‐D GC‐qMS approach enabled the determination of a high number of hazardous contaminants (aliphatic hydrocarbons, polycyclic aromatic hydrocarbons, and plasticizers), barely visible in the GC‐qMS analysis.
Matrix effects observed during pesticides residue analysis in fruits by GC
Authors: de Sousa Freitas Silvia , Lanças Fernando M.
Published: October 2009

The influence of the sample matrix in the GC‐electron‐capture detection analysis of the pesticides dimethoate, diazinon, chlorothalonil, parathion methyl and fenitrothion in fruits samples has been studied. Experiments have been carried out where the pesticide responses in standard solutions prepared in selected solvent were compared with their response when present in apple, mango, papaya, banana, pineapple and melon extracts. The presence of matrix effects (MEs) and their extent were shown to be simultaneously influenced by several factors (matrix concentration, matrix type, pesticide concentration, analytical range). Pronounced MEs were observed particularly for dimethoate and diazinon in all matrices tested; in lower concentrations, all pesticides presented significant ME. The other pesticides presented variable ME. Higher ME enhancement was detected at lower pesticide concentration levels of and/or at higher matrix concentration solutions. The ME detected for fenitrothion, in the analytical range evaluated, were dependent on matrix type. For each pesticide, solvent and matrix‐matched calibrations were compared for all fruit samples, and it could be concluded that quantitation based on standard solutions prepared in blank matrix extract (matrix‐matched calibration) should be used to compensate the MEs and to obtain more accurate results for the pesticides studied.
Single‐step purification of dracorhodin from dragon's blood resin of Daemonorops draco using high‐speed counter‐current chromatography combined with pH modulation
Authors: Shi Jianmei , Hu Ruilin , Lu Yanbin , Sun Cuirong , Wu Tianxing
Published: October 2009

Dracorhodin is a major constituent found in “Dragon's blood” resin of Daemonorops draco Willd. Blume. This natural flavylium compound is a potent pharmaceutical substance due to its biological and pharmacological activities such as antimicrobial, antiviral, antitumor and cytotoxic activity. An effective high‐speed counter‐current chromatography method was successfully established for the isolation and purification of dracorhodin directly from extract of D. draco by using a two‐phase solvent system composed of n‐hexane/ethyl acetate/methanol/water (2:3:2:3 v/v). Under the optimal conditions, 6.6 mg dracorhodin was obtained from 100 mg crude resin. The isolated fraction of counter‐current chromatography was determined by HPLC, NMR, UV/visible and ESI/MS combined with pH modulation, since dracorhodin is unstable in solution which exists in different forms depending on pH values. The data were compared with those of the reference substance, and the literatures as well. The purity of dracorhodin was over 98% based on the HPLC result.
The concept of knowledge in KM: A knowledge domain process model applied to inter‐professional care
Authors: Evans Michael Max , Alleyne Joel
Published: October 2009

Grounded in a social construction view of knowledge and based on the work of Haridimos Tsoukas and Max Boisot, this paper attempts to extend Colin Reilly's knowledge domain model using a process modeling approach. The objective of this paper is to construct a more comprehensive meta‐understanding of knowledge domains that considers the influence of organizational context, of a community or group (social construction of knowledge), the presence of events and knowledge artifacts, temporal cycles, and individual knowledge processes.

The authors begin by synthesizing the existing literature review to construct the proposed Knowledge Domain Process (KDP) model. Following the construction of the model, the authors develop and use a composite case (from a number of cases experienced by one of the authors as a practitioner) to illustrate the application of the model. The proposed model is then applied to an Inter‐Professional Care (IPC) setting within health care, to illustrate how knowledge is constructed, exchanged, and used across numerous health care communities, in an effort to improve coordination and care.

The KDP model attempts to provide researchers and practitioners with a more structured, detailed, and analytical way of looking at the processes involved in knowledge construction and dissemination. This model is viewed as a work‐in‐progress and is still under development. Use by others is encouraged and will help validate or refute the model in part or in whole. Copyright © 2009 John Wiley & Sons, Ltd.
Transoral resection of short segment Zenker's diverticulum and cricopharyngeal myotomy: An alternative minimally invasive approach
Authors: Mortensen Melissa , Schaberg Madeleine R. , Genden Eric M. , Woo Peak
Published: October 2009

Objectives/Hypothesis:

Transoral treatment of cricopharyngeal bar and small Zenker's diverticulum remains a challenge. We propose a new transoral approach for transoral cricopharyngeal myotomy (TOCPM) for patients with cricopharyngeal spasm and pharyngeal bar, and for transoral resection of diverticula (TORD) with cricopharyngeal myotomy in the patient with small (<3 cm) Zenker's diverticulum.

Methods:

A retrospective review was conducted of 45 patients with cricopharyngeal spasm (21) and Zenker's diverticulum (24), where 14 patients were considered suitable for TORD and TOCPM. TOCPM used the Weerda laryngoscope (Karl Storz, Tuttlingen, Germany) to expose the cricopharyngeal bar using a microscope; the mucosa is cut and then the muscle is transected using monopolar cautery. A 0° endoscope is inserted through the incision to ensure complete myotomy. Incision closure is by interrupted 4‐0 Vicryl sutures (Ethicon Inc., Somerville, NJ) and fibrin glue. For the TORD procedure, the diverticular sac is everted and then resected using scissors. Through the sac opening, the TOCPM is completed. The sac opening is then closed as described in TOCPM. The patients are kept without food for 24 hours, followed by feeding and discharge. Modified barium swallow (MBS) evaluated functional results.

Results:

Fourteen patients underwent TOCPM (eight), and TOCPM+TORD (six). There was one case of TOCPM that was aborted due to excessive bleeding, which prevented full myotomy. The rest did well. All were discharged the next day. Two poor results from the TOCPM and TOCPM+TORD group were due to poor esophageal motility. The remainder of patients had resolution of dysphagia and normalized MBS. No patient developed stricture or complications.

Conclusions:

Short segment Zenker's diverticulum and cricopharyngeal bar can now be addressed completely with a transoral approach. Because there is complete closure of the mucosal incision, prolonged hospitalization can be avoided. Laryngoscope, 2010
Bone chip‐induced rhinosinusitis
Authors: Reilly Brian K. , Conley David B.
Published: October 2009

This case report describes both the pathophysiology and management of chronic rhinosinusitis (CRS). Specifically, we report a case of chronic maxillary rhinosinusitis with a free‐floating maxillary sinus calcification (bone chip). After obtaining the computed tomography scan, the patient underwent endoscopic sinus surgery, with removal of the uncinate, enlargement of the diseased natural ostium of the maxillary sinus, and removal of the diseased bone chip. This eliminated the nidus for infection, ultimately restoring mucociliary flow. Laryngoscope, 2009
Additional heterozygous 2507A>C mutation of WFS1 in progressive hearing loss at lower frequencies
Authors: Fujikawa Taro , Noguchi Yoshihiro , Ito Taku , Takahashi Masatoki , Kitamura Ken
Published: October 2009

Objectives/Hypothesis:

To describe the audiological profiles in a Japanese family with autosomal dominant hereditary sensorineural hearing loss (SNHL) and to identify the causative gene.

Study Design:

A family study at an academic tertiary referral center.

Methods:

A family with autosomal dominant hereditary SNHL was enrolled. Hearing loss (HL) of affected members showed mid‐frequency SNHL in childhood and progressed at lower frequencies with age, resulting in low‐frequency SNHL. To understand the pathology of HL of this family, we performed a genetic analysis of WFS1, TECTA, and GJB2 by direct sequencing, and further audiovestibular examinations, including speech audiometry, distortion product otoacoustic emissions, electrocochleography, auditory brainstem responses, and electronystagmography for some affected members.

Results:

A heterozygous A‐to‐C nucleotide transversion (c.2507A>C), resulting in a lysine‐to‐threonine substitution at codon 836 (K836T) was identified in exon 8 of WFS1. K836T was segregated with HL in the 15 participants in the genetic study but was not detected in the 212 normal chromosomes. Only polymorphic changes were detected in TECTA and GJB2. Audiovestibular examinations indicated purely cochlear HL and normal vestibular function. The summating potential/action potential ratios in electrocochleography increased in the bilateral ears of the proband.

Conclusions:

The family described with autosomal dominant inheritance of K836T of the WFS1 gene demonstrates a progressive hearing loss in the lower frequencies. Laryngoscope, 2010
Is severe epistaxis associated with acetylsalicylic acid intake?
Authors: Soyka Michael B. , Rufibach Kaspar , Huber Alex , Holzmann David
Published: October 2009

Objectives/Hypothesis:

Epistaxis represents a very common emergency in any ear, nose, and throat (ENT) department around the world. Despite other risk factors, acetylsalicylic acid (ASA) contributes to nosebleeds by its intrinsic ability to impair thrombocyte aggregation. The aim of this study was to investigate the influence of ASA on the severity of epistaxis and to compare it with other potential risk factors.

Study Design:

A prospective cohort study was performed at the ENT department of University Hospital Zurich.

Methods:

A total of 591 events were evaluated concerning surgical interventions and the length of in‐hospital stay. Further analyses regarding recurrences and number of treatments and a specially designed severity score, as well as other outcome parameters, were performed.

Results:

Ninety‐nine patients needed to stay in‐hospital for at least 1 day. Nearly 30% of all patients had ASA intake, and only 18% were on vitamin K antagonist therapy. Patients on ASA showed significantly more surgical interventions, a higher recurrence rate, and a larger number of required treatments as well as an increased severity score. Duration of in‐hospital stay and the complication rate, however, were not associated with drug intake.

Conclusions:

We not only identified ASA to be one of the major risk factors in epistaxis, but also quantified its impact on the severity of nose bleeding. We emphasize the importance of a well‐indicated antiaggregational therapy, and strongly discourage using ASA as a life‐style drug for the elderly. ASA therapy needs to be discontinued whenever possible and reasonable. Laryngoscope, 2010
Management of patients treated with chemoradiotherapy for head and neck cancer without prophylactic feeding tubes: The University of Pittsburgh experience
Authors: McLaughlin Brian T. , Gokhale Abhay S. , Shuai Yongli , Diacopoulos Joyce , Carrau Ricardo , Heron Dwight E. , Smith Ryan P. , Gibson Michael K. , Ferris Robert L. , Grandis Jennifer R. , Johnson Jonas T. , Argiris Athanassios
Published: October 2009

Objectives/Hypothesis:

Mucositis and dysphagia are common complications of chemoradiotherapy (CRT) for head and neck cancer that may necessitate nutritional support with a gastrostomy tube (G‐tube).

Methods:

We reviewed records of patients who underwent and completed CRT, which included at least one traditional chemotherapeutic, for previously untreated head and neck cancer. G‐tubes were placed as needed. The timing and duration of G‐tube placement and treatment‐related complications and risk factors for long‐term G‐tube use were analyzed.

Results:

A total of 91 consecutive patients who received CRT, 68 as primary and 23 as postoperative treatment, were studied. Radiation doses ranged from 59.4 to 74 Gy (median, 70 Gy). Seventy‐nine percent of patients received platinum‐based therapy during CRT. Severe mucositis occurred in 40% of patients. Forty percent of patients required G‐tube placement (15 prior to CRT and 21 during CRT). Median duration of G‐tube use was 5.8 months. Two patients who had a G‐tube placed during CRT developed a G‐tube‐related complication. At 6 and 12 months, 15 (18%) and four (6%) patients who were disease free were using G‐tubes, respectively. Patients with G‐tubes placed prior to CRT or advanced T stage had longer G‐tube dependence.

Conclusions:

With aggressive supportive care it is feasible to avoid G‐tubes in the majority of patients undergoing CRT for head and neck cancer. G‐tube placement prior to CRT due to pre‐existing dysphagia and advanced T stage are associated with prolonged G‐tube dependence. Laryngoscope, 2010
Human liver transplantation as a model to study hepatitis C virus pathogenesis
Authors: Hughes Michael G. , Rosen Hugo R.
Published: October 2009

Hepatitis C is a leading etiology of liver cancer and a leading reason for liver transplantation. Although new therapies have improved the rates of sustained response, a large proportion of patients (˜50%) fail to respond to antiviral treatment, thus remaining at risk for disease progression. Although chimpanzees have been used to study hepatitis C virus biology and treatments, their cost is quite high, and their use is strictly regulated; indeed, the National Institutes of Health no longer supports the breeding of chimpanzees for study. The development of hepatitis C virus therapies has been hindered by the relative paucity of small animal models for studying hepatitis C virus pathogenesis. This review presents the strengths of human liver transplantation and highlights the advances derived from this model, including insights into viral kinetics and quasispecies, viral receptor binding and entry, and innate and adaptive immunity. Moreover, consideration is given to current and emerging antiviral therapeutic approaches based on translational research results. Liver Transpl 15:1395–1411, 2009. © 2009 AASLD.
Liver graft exposure to carbon monoxide during cold storage protects sinusoidal endothelial cells and ameliorates reperfusion injury in rats
Authors: Ikeda Atsushi , Ueki Shinya , Nakao Atsunori , Tomiyama Koji , Ross Mark A. , Stolz Donna B. , Geller David A. , Murase Noriko
Published: October 2009

Hepatic ischemia/reperfusion (I/R) injury significantly influences short-term and long-term outcomes after liver transplantation (LTx). The critical step initiating the injury is known to include sinusoidal endothelial cell (SEC) alteration during the cold preservation period. As carbon monoxide (CO) has potent cytoprotective functions on vascular endothelial cells, this study examined if CO treatment of excised liver grafts during cold storage could protect SECs and ameliorate hepatic I/R injury. Rat liver grafts were preserved in University of Wisconsin (UW) solution containing 5% CO (CO-UW solution) for 18 to 24 hours and were transplanted into syngeneic Lewis rats. After 18 hours of cold preservation, SEC damage was evident with propidium iodide (PI) nuclear staining on SECs, and the frequency of PI+ SECs was significantly lower in grafts stored in CO-UW solution versus those stored in control UW solution. SEC protection with CO was associated with decreased intercellular cell adhesion molecule translocation and less matrix metalloproteinase release during cold preservation. After LTx with 18 hours of cold preservation, serum alanine aminotransferase levels and hepatic necrosis were significantly less in the CO-UW group than in the control UW group. With 24 hours of cold storage, 35% (7/20) survived with control UW solution, whereas the survival with CO-UW solution improved to 80% (8/10). These beneficial effects of CO-UW solution were associated with a significant reduction of neutrophil extravasation, down-regulation of hepatic messenger RNA for tumor necrosis factor alpha and intercellular cell adhesion molecule 1, and less hepatic extracellular signal-regulated kinase activation. Liver grafts from Kupffer cell–depleted donors or pseudogerm-free donors showed less SEC death during cold preservation, and CO-UW solution further reduced SEC death. In conclusion, CO delivery to excised liver grafts during cold preservation efficiently ameliorates SEC damage and hepatic I/R injury. Liver Transpl 15:1458–1468, 2009. © 2009 AASLD.