bluuebunny/crossref_metadata_2025 huggingface dataset:
Littermate presence enhances motor development, weight gain and competitive ability in newborn and juvenile domestic rabbits
Authors: Nicolás Leticia , Martínez‐Gómez Margarita , Hudson Robyn , Bautista Amando
Published: August 2010

Interest has been growing in the influence siblings may have on individual development. While mammalian research has tended to emphasize competition among siblings for essential but often limited resources such as the mother's milk, there is also evidence of mutual benefits to be had from sibling presence, most notably for altricial young in enhanced thermoregulatory efficiency. In the present study we asked whether littermates of an altricial mammal, the domestic rabbit, might gain other developmental benefits from sibling presence. From postnatal days 1 to 25 we raised rabbit pups either together with their littermates or alone except for the brief, once daily nursing characteristic of this species, while controlling for litter size and ambient nest box temperature. At weaning on Day 25 the young were then transferred to individual cages. Before weaning, we found that pups raised separately from their littermates obtained less milk, and showed lower weight gain and slower development of the ability to maintain body equilibrium than their litter‐raised sibs. This was the case even though the two groups did not differ in birth weight or in the ratio of converting milk into body mass in their temperature‐controlled nest boxes. Postweaning, the isolation‐raised animals were also less successful in competing for food and water when tested after deprivation than their litter‐raised sibs. The present study adds to the growing evidence of the influence, in this case positive, that sibs (or half sibs) may have in shaping one another's development. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 53: 37–46, 2011.
Cholesterol oxides content in selected animal products determined by GC‐MS
Authors: Derewiaka Dorota , Obiedziński Mieczyslaw
Published: August 2010

The aim of this study was to evaluate the effect of heat treatment of selected animal products on formation of cholesterol oxidation products (COP) and also to determine their content in selected pates and fermented pork sausage which are available on the Polish market. COP content in pates was significantly lower as compared to fermented sausages, and ranged from 39.5 to 43.1 µg/100 g; COP in sausages ranged from 195.8 to 263.4 µg/100 g of product. COP content in pan fried meats, chops, and fish fillets varied from 6.2 to 991.2 µg/100 g products. This paper demonstrates the method for determining the content of COP by the use of selected ion technique with the aid of MS.

Practical applications: The method described is useful for the investigation of oxysterols in food matrices. The method is used for the investigation of the presence and content of COP, such as: 7β‐hydroxycholesterol, 5α,6α‐epoxycholesterol, 5β,6β‐epoxycholesterol, 5α‐cholestane‐3β,5β,6β‐triol, 7‐ketocholesterol, and 25‐hydroxycholesterol. The obtained data about COP content in selected animal products and their formation during heat treatment are crucial for creating a reliable database to assess their daily intakes and biological effects in humans.
Enzymatic epoxidation of soybean oil methyl esters in the presence of free fatty acids
Authors: Lu Hao , Sun Shangde , Bi Yanlan , Yang Guolong , Ma Rulan , Yang Huifang
Published: August 2010

Epoxides of soybean oil methyl esters (SMEs) are biodegradable, non‐toxic, and renewable epoxy plasticizers. The objective of the present work was to investigate the effects of free fatty acids on the enzymatic epoxidation of SMEs. The results showed that the epoxidation of SMEs depended on the type of the added free fatty acid. For saturated (≤C18:0) and monounsaturated free fatty acids, the epoxy oxygen group content (EOC) of SMEs increased with increasing carbon chain length of free fatty acids; for branched‐chain unsaturated free fatty acids, the EOC of SMEs decreased in the presence of hydroxyl group (OH) and hydroperoxide (OOH) of free fatty acids; the EOC of SMEs decreased with increasing number of double bonds of free fatty acids. The maximum EOC and the initial epoxidization rate (V0) linearly decreased with increasing peroxide value of SMEs. The highest EOC (6.87 ± 0.3%) of SMEs was obtained using behenic acid as reaction material, which was similar with that of stearic acid (EOC 6.75 ± 0.2%).
Rapid FTIR determination of water, phenolics and antioxidant activity of olive oil
Authors: Cerretani Lorenzo , Giuliani Angela , Maggio Rubén M. , Bendini Alessandra , Gallina Toschi Tullia , Cichelli Angelo
Published: August 2010

A rapid Fourier transformed infrared (FTIR) attenuated total reflectance (ATR) spectroscopic method was applied to the determination of water content (WC), total phenol amount (TP) and antioxidant activity (ABTS.+) of virgin olive oils (VOO) and olive oils. Calibration models were constructed using partial least squares regression. Oil samples with WC ranging from 289 to 1402 mg water/kg oil, with TP from 46 to 877 mg gallic acid/kg oil and with ABTS.+ from 0 to 5.7 mmol Trolox/kg oil were considered for chemometric analysis. Better results were obtained when selecting suitable spectral ranges; in particular, from 2260 to 1008 cm−1 for WC, from 3610 to 816 cm−1 for TP and from 3707 to 1105 cm−1 for ABTS.+. Satisfactory LOD values by the FTIR‐chemometric methods were achieved: 9.4 (mg/kg oil) for WC; 12.5 (mg gallic acid/kg oil) for TP, and 0.76 (mmol Trolox/kg oil) for ABTS.+. The evaluation of the applicability of these analytical approaches was tested by use of validation sample sets (n = 16 for WC, n = 11 for TP and n = 14 for ABTS) with nearly quantitative recovery rates (99–114%). The FTIR–ATR method provided results that were comparable to conventional procedures.

Practical applications: The presented method is based on ATR–FTIR in combination with multivariate calibration methodologies and permits a simultaneous evaluation of important quality parameters of VOO (WC, TP and ABTS.+). This approach represents an easy and convenient means for monitoring olive oil quality with the advantage of ease of operation, speed, no sample pretreatment and no consumption of solvents. The data obtained with this method are comparable to those obtained using the official reference method. Therefore, the technique is highly plausible as an alternative to the standard procedure for routine analysis or control at‐line of production processes.
Conjugated linoleic acid‐producing enzymes: A bioinformatics study
Authors: Farmani Jamshid , Safari Mohammad , Roohvand Farzin , Razavi Seyyed Hadi , Aghasadeghi Mohammad Reza , Noorbazargan Hassan
Published: August 2010

Linoleic acid isomerases (LAI) are enzymes responsible for conversion of linoleic acid (LA) to conjugated linoleic acids (CLA) in different isomeric forms. CLAs are well known for numerous beneficial effects as functional foods. Despite identification of several LAI producing‐bacteria and release of their LAI nucleotide sequences to Bio‐Banks, no related bioinformatics study on these important enzymes is addressed yet. To gain insights into the structural/functional and phylogentic relations of LAIs as well as recombinant production of the desired enzyme, we employed several bioinformatical tools to analyze their primary structure and physicochemical properties. The results indicated that LAIs produced in different bacterial strains might be divided in two distinct families (Propionibacterium acnes and myosin cross‐reactive antigen (MCRA)‐like LAIs) with specific isomerase activities. In another part of the study, physicochemical properties, solubility upon over expression in E. coli, disulfide bond formation, and potential glycosylation sites in LAI sequences were predicted using bioinformatics tools and the most appropriate strategy for recombinant production of each LAI was determined. Our predicted data may be useful for further experimental studies toward production of the desired LAI.
Conjugation Is Essential for the Anticholestatic Effect of Nor Ursodeoxycholic Acid in Taurolithocholic Acid–Induced Cholestasis in Rat Liver
Authors: Denk Gerald U. , Maitz Silvia , Wimmer Ralf , Rust Christian , Invernizzi Pietro , Ferdinandusse Sacha , Kulik Wim , Fuchsbichler Andrea , Fickert Peter , Trauner Michael , Hofmann Alan F. , Beuers Ulrich
Published: August 2010

Nor

UDCA (24-
nor

ursodeoxycholic acid), the C23-homolog of ursodeoxycholic acid (UDCA), showed remarkable therapeutic effects in cholestatic

Mdr2

(

Abcb4

) (multidrug resistance protein 2/ATP-binding cassette b4) knockout mice with sclerosing/fibrosing cholangitis. In contrast to UDCA,

nor

UDCA is inefficiently conjugated in human and rodent liver, and conjugation has been discussed as a key step for the anticholestatic action of UDCA in cholestasis. We compared the choleretic, anticholestatic, and antiapoptotic properties of unconjugated and taurine-conjugated UDCA (C24) and

nor

UDCA (C23) in isolated perfused rat liver (IPRL) and in natrium/taurocholate cotransporting polypeptide (Ntcp)-transfected human hepatoma (HepG2) cells. Taurolithocholic acid (TLCA) was used to induce a predominantly hepatocellular cholestasis in IPRL. Bile flow was determined gravimetrically; bile acids determined by gas chromatography and liquid chromatography/tandem mass spectrometry; the Mrp2 model substrate, 2,4-dinitrophenyl-S-glutathione (GS-DNP) was determined spectrophotometrically; and apoptosis was determined immunocytochemically. The choleretic effect of C23-bile acids was comparable to their C24-homologs in IPRL. In contrast, T

nor

UDCA, but not

nor

UDCA antagonized the cholestatic effect of TLCA. Bile flow (percent of controls) was 8% with TLCA-induced cholestasis, and unchanged by coinfusion of

nor

UDCA (14%). However, it was increased by T

nor

UDCA (83%), UDCA (73%) and TUDCA (136%). Secretion of GS-DNP was markedly reduced by TLCA (5%), unimproved by

nor

UDCA (4%) or UDCA (17%), but was improved modestly by T

nor

UDCA (26%) or TUDCA (58%). No apoptosis was observed in IPRL exposed to low micromolar TLCA, but equivalent antiapoptotic effects of TUDCA and T

nor

UDCA were observed in Ntcp-HepG2 cells exposed to TLCA.

Conclusion:

Conjugation is essential for the anticholestatic effect of

nor

UDCA in a model of hepatocellular cholestasis. Combined therapy with UDCA and

nor

UDCA may be superior to UDCA or

nor

UDCA monotherapy in biliary disorders in which hepatocyte as well as cholangiocyte dysfunction contribute to disease progression. (Hepatology 2010;52:1758-1768)
Micro-RNA profiling reveals a role for miR-29 in human and murine liver fibrosis
Authors: Roderburg Christoph , Urban Gerd-Willem , Bettermann Kira , Vucur Mihael , Zimmermann Henning , Schmidt Sabine , Janssen Jörn , Koppe Christiane , Knolle Percy , Castoldi Mirco , Tacke Frank , Trautwein Christian , Luedde Tom
Published: August 2010

Liver fibrosis is orchestrated by a complex network of signaling pathways regulating the deposition of extracellular matrix proteins during fibrogenesis. MicroRNAs (miRNAs) represent a family of small noncoding RNAs controlling translation and transcription of many genes. Recently, miRNAs have been suggested to crucially modulate cellular processes in the liver such as hepatocarcinogenesis. However, their role in liver fibrosis is not well understood. We systematically analyzed the regulation of miRNAs in a mouse model of carbon tetrachloride–induced hepatic fibrogenesis (CCl4) by gene array analysis, which revealed a panel of miRNA that were specifically regulated in livers of mice undergoing hepatic fibrosis. Within those, all three members of the miR-29-family were significantly down-regulated in livers of CCl4-treated mice as well as in mice that underwent bile duct ligation. Specific regulation of miR-29 members in murine fibrosis models correlated with lower expression of miR-29 in livers from patients with advanced liver fibrosis. Moreover, patients with advanced liver cirrhosis showed significantly lower levels of miR-29a in their serum when compared with healthy controls or patients with early fibrosis. On a cellular level, down-regulation of miR-29 in murine hepatic stellate cells (HSCs) was mediated by transforming growth factor beta (TGF-β) as well as inflammatory signals, namely, lipopolysaccharide (LPS) and nuclear factor kappa B (NF-κB). Furthermore, overexpression of miR-29b in murine HSC resulted in down-regulation of collagen expression.

Conclusion:

Our data indicate that miR-29 mediates the regulation of liver fibrosis and is part of a signaling nexus involving TGF-β- and NF-κB–dependent down-regulation of miR-29 family members in HSC with subsequent up-regulation of extracellular matrix genes. Thus they may represent targets for novel therapeutic strategies against hepatic fibrogenesis and also might evolve as biomarkers in the diagnosis of liver fibrosis. (Hepatology 2011.)
Chinese firms' outward direct investment: Technological innovation mechanisms, organizational modes, and improving strategies
Authors: Zhao Jingyuan , Ordóñez de Pablos Patricia
Published: August 2010

Although Chinese outward direct investment (ODI) started late, it has increased rapidly. China is gradually changing from the receiver of foreign direct investment (FDI) to the exporter of ODI. With the advent of the era of knowledge economy, knowledge and innovation have become the core elements of organizational competitive advantages. The practice of current international direct investment shows that it is difficult to acquire advanced technologies only by means of the introduction of FDI: The development of ODI is an important way to obtain foreign advanced technologies. Chinese firms' ODI faces some problems in technological innovations, and the total of technology‐sourcing ODI is not large. This article focuses on the technological innovations of Chinese firms' ODI, discusses technological innovation mechanisms and organizational modes of Chinese ODI firms, and presents the technological innovation framework and strategies to strengthen the technological innovation advantage of Chinese ODI firms. © 2010 Wiley Periodicals, Inc.
Density functional theory investigation of Cu(I)‐ and Cu(II)‐curcumin complexes
Authors: Addicoat Matthew A. , Metha Gregory F. , Kee Tak W.
Published: August 2010

Density functional theory is used to obtain the lowest energy geometries of bis‐aqua curcumin complexes and bis‐curcumin complexes of Cu(I) and Cu(II). Three conformations of curcumin, obtained by rotation of the substituted aromatic groups, were considered in each case. Steric repulsion, due to the methoxy–methoxy interactions, was found to be an important factor in determining the lowest energy conformer of Cu(II)(curcumin)2 but was less important for the Cu(I) analog. Using a sufficiently large basis set, the results show that the lowest energy Cu(II)(curcumin)2 geometry is square planar around the copper atom, in contrast to the results from a previous study (Shen et al. THEOCHEM‐J Mol Struct 2005, 757, 199). In addition, other studies suggested that the formation of this complex is followed by the reduction of Cu(II) to Cu(I). We also examined the singly occupied molecular orbital, spin density, and natural bond orbitals of Cu(II)(curcumin)2. While the former two analyses show little evidence of electron transfer from curcumin into the Cu center, the latter indicates that Cu(II) is partially reduced to Cu(I) as a consequence of complexation. Finally, we consider the bis‐aqua curcumin and bis‐curcumin complexes on a reaction path involving progressive displacement of water molecules by curcumin ligands. The results show that the bis‐curcumin complex is the most stable Cu(II) complex, showing consistently exothermic steps in the reaction path. However, for Cu(I), the final step in the reaction path is essentially thermoneutral, indicating that the 1:1 and 1:2 Cu(I) complexes are equally stable thermodynamically. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2011
Nano‐structured MgH2 catalyzed by TiC nanoparticles for hydrogen storage
Authors: Tian Mi , Shang Congxiao
Published: August 2010

BACKGROUND: Magnesium hydride is considered to be a promising hydrogen storage material because of its high gravimetric and volumetric storage capacities. However, its slow kinetics and high desorption temperature of > 300 °C limit practical applications. In this work, TiC nanoparticles were selected to modify the hydrogen storage properties of MgH2. Composite mixtures (MgH2 + TiC) were prepared using both cryogenic milling and high‐energy ball milling.

RESULTS: The resulting morphology and crystallite structure of the composites were identified by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X‐ray diffraction (XRD). The milled samples show good mixing of the hydride and carbide particles, with MgH2 particles around 0.09–1 µm and TiC particles 10–20 nm. The (MgH2 + TiC) composites consist of γ‐MgH2, β‐MgH2 and TiC. MgH2 nano‐crystallites of 25 nm were formed after cryomilling. Thermogravimetry reveals that the composites release ∼6.5 mass % hydrogen from 190–400 °C at a heating rate of 10 °C min−1 under He flow, with the onset and peak temperatures at 190 and 280 °C, respectively, for the (MgH2 + TiC) after 8 h cryomilling and 60 h ball milling.

CONCLUSION: Results indicate that TiC is an effective catalyst for hydrogen desorption of MgH2. Copyright © 2010 Society of Chemical Industry
Structural studies of 2‐methyl‐7‐substituted pyrazolo[1,5‐a]pyrimidines
Authors: Frizzo Clarissa P. , Martins Marcos A.P. , Marzari Mara R. B. , Campos Patrick T. , Claramunt Rosa M. , García M. Ángeles , Sanz Dionisia , Alkorta Ibon , Elguero José
Published: August 2010

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Six pyrazolo[1,5‐a]pyrimidines bearing a 7‐trifluoromethyl (three compounds), a 7‐trichloromethyl (two compounds), and a 7‐ethoxycarbonyl (one compound) have been structurally characterized. The new X‐ray structures of 2‐methyl‐5‐(p‐bromophenyl)‐7‐trifluoromethylpyrazolo[1,5‐a]pyrimidine (3) and 2‐methyl‐7‐trichloromethylpyrazolo[1,5‐a]pyrimidine (4) are reported. The combined use of GIAO/B3LYP/6‐311++G(d,p) calculations with NMR spectroscopy in solution and in the solid state allows to establish some general rules that can be useful for characterizing related compounds. Compounds 3 and 4 present in the solid‐state interesting intra‐ and intermolecular halogen bonds. J. Heterocyclic Chem., (2010).
Synthesis and anti‐Helicobacter pylori activity of 4‐(coumarin‐3‐yl)thiazol‐2‐ylhydrazone derivatives
Authors: Chimenti Franco , Bizzarri Bruna , Bolasco Adriana , Secci Daniela , Chimenti Paola , Granese Arianna , Carradori Simone , D'Ascenzio Melissa , Scaltrito M. Maddalena , Sisto Francesca
Published: August 2010

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A novel class of coumarin‐thiazole conjugated systems (1‐31) were synthesized by Hantzsch condensation between α‐bromo‐3‐acetyl coumarin and several thiosemicarbazone intermediates. This scaffold was also evaluated for selective antibacterial activity against 20 isolates of H. pylori clinical strains, including four metronidazole resistant ones. J. Heterocyclic Chem., (2010).
An efficient and clean synthesis of indeno[1,2‐b]pyrazolo[4,3‐e] pyridin‐5(1H)‐one derivatives under microwave irradiation in water
Authors: Wang Shuliang , Ma Ning , Zhang Ge , Shi Feng , Jiang Bo , Lu Han , Gao Yuan , Tu Shujiang
Published: August 2010

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A series of new indeno[1,2‐b]pyrazolo[4,3‐e]pyridin‐5(1H)‐one derivatives were synthesized by three‐component reactions of 1,3‐indandione, 3‐methyl‐1H‐pyrazol‐5‐amine, and aldehyde in water under microwave irradiation without any catalyst. J. Heterocyclic Chem., (2010).
Synthesis of 2,3‐dihydroimidazo[2,1‐b]thiazole derivatives viacyclization of N‐allylimidazoline‐2‐thiones
Authors: Jasiński Marcin , Mlostoń Grzegorz , Heimgartner Heinz
Published: August 2010

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A novel method for the preparation of 2,3‐dihydroimidazo[2,1‐b]thiazole 9 by iodination and subsequent cyclization of the easily available N‐allylimidazoline‐2‐thiones 5, is described. Selected transformations of the iodomethyl derivatives 9, leading to methylidene compounds 10 or the sulfide 11 (Nu = RS), via elimination with a base or via substitution with an enolizable imidazoline‐2‐thione (the term “1,3‐dihydroimidazole‐2‐thione” will be used alternatively), respectively, are presented. J. Heterocyclic Chem., (2010).
Intramolecular cyclization of Mannich reaction for synthesis of pyrimido[2,1‐b]‐1,3,5‐tiadiazines
Authors: El‐Sherief Hassan A. H. , Hozien Zeinab A. , El‐Mahdy Ahmed F. M. , Sarhan Abdelwarth A. O.
Published: August 2010

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Reaction of 6‐aryl‐5‐cyano‐2‐mercapto‐3,4‐dihydropyrimidin‐4‐ones with formaldehyde and primary amines in suitable solvent via a double Mannich reaction gave the corresponding 8‐aryl‐7‐cyano‐3‐N‐substituted‐pyrimido[2,1‐b]‐1,3,5‐thiadiazin‐6‐ones rather than the isomeric products 6‐aryl‐7‐cyano‐3‐N‐substituted‐pyrimido[2,1‐b]‐1,3,5‐thiadiazin‐8‐ones. The cyclization method was found to be the most favored for the formation of the linear products rather than the angular isomers. This was confirmed not only by using spectral analysis and molecular mechanical calculations but also by X‐ray single crystal structure determination. J. Heterocyclic Chem., (2010).
First synthesis of 2‐(2,4,4‐trimethyl‐3,4‐dihydro‐2H‐benzo[h]chromen‐2‐yl)‐1‐naphthol and 3‐(2,4,4‐trimethyl‐3,4‐dihydro‐2H‐benzo[g]chromen‐2‐yl)‐2‐naphthol from 1‐ and 2‐naphthol derivatives
Authors: Menezes Jose C. J. M. D. S. , Srinivasan Bikshandarkoil R. , Raghavaiah Pallepogu , Paknikar Shashikumar K. , Kamat Shrivallabh P.
Published: August 2010

Two new structurally isomeric, 2‐(2,4,4‐trimethyl‐3,4‐dihydro‐2H‐benzo[h]chromen‐2‐yl)‐1‐naphthol (1) and 3‐(2,4,4‐trimethyl‐3,4‐dihydro‐2H‐benzo[g]chromen‐2‐yl)‐2‐naphthol (3) have been synthesized from 2‐acetyl‐1‐naphthol and ethyl‐3‐hydroxy‐2‐naphthoate, respectively, involving Grignard reaction, dehydration of the corresponding tertiary alcohols, and hetero Diels–Alder dimerization. The two benzochromenes (1 and 3) have been fully characterized by IR, NMR, and HRESIMS data. Their structures are further supported by crystallography of their corresponding acetates (2 and 4). J. Heterocyclic Chem., (2011).
Solvent‐free microwave extraction coupled with headspace single‐drop microextraction of essential oils from flower of Eugenia caryophyllata Thunb.
Authors: Jiang Chunzhu , Sun Ying , Zhu Xiaonan , Gao Yan , Wang Liying , Wang Jian , Wu Liwei , Song Daqian
Published: August 2010

Solvent‐free microwave extraction coupled with headspace single‐drop microextraction was developed for extracting the essential oils from Eugenia caryophyllata Thunb. Carbonyl iron powders were mixed with the sample to extract essential oils from the dried plant materials and single‐drop solvent was used to simultaneously extract essential oils from the headspace. The single‐drop of decane was suspended from the tip of a microsyringe and exposed to the headspace above the sample. After the extraction was finished, the single‐drop was injected into gas chromatographic system and analyzed by GC‐MS. The effects of the experimental parameters, including microwave power, microwave irradiation time, the ratio of carbonyl iron powder to sample, extraction solvent, single‐drop volume and extraction time, were investigated. Sixteen compounds in the essential oils of E. caryophyllata T. were obtained and identified. The constituents of essential oils obtained by hydro‐distillation and solvent‐free microwave extraction–headspace single‐drop microextraction were not obviously different. Compared with hydro‐distillation, the proposed method required shorter extraction time and less amount of the sample.
Sorbent‐packed needle microextraction trap for benzene, toluene, ethylbenzene, and xylenes determination in aqueous samples
Authors: De Crom Jorn , Claeys Sara , Godayol Anna , Alonso Monica , Anticó Enriqueta , Sanchez Juan M.
Published: August 2010

A needle trap (NT) device filled with Carbopack X as a sorbent material is evaluated for the static headspace analysis of benzene, toluene, ethylbenzene, and xylene (BTEX) compounds in aqueous samples. Injection parameters used with the NT device (e.g. volume of carrier gas and time to open the split valve) are evaluated to determine the mechanism involved during the desorption and transferring of the target compounds into the GC column. Furthermore, different parameters affecting the adsorption capacity of the sorbent are studied (e.g. sampling time and temperature, headspace/sample volume ratio, salting‐out, and stirring). The evaluation of the method with aqueous samples shows that repeatability and recoveries with the NT device are equivalent to those obtained using solid‐phase microextraction with a carboxen/PDMS (CAR/PDMS) coating. LODs obtained with flame ionization detection are in the range of 10–25 μg/L, and in the range of hundredths of μg/L with MS detection. The method developed is satisfactorily applied to the analysis of aqueous samples obtained from wastewater treatment plants.
Rapid and refined separation of human IgG2 disulfide isomers using superficially porous particles
Authors: Wang Qian , Lacher Nathan A. , Muralidhara Bilikallahalli K. , Schlittler Michael R. , Aykent Serdar , Demarest Charles W.
Published: August 2010

A rapid reversed‐phase HPLC separation of recombinant human immunoglobulin gamma 2 (IgG2) disulfide isomers using columns packed with superficially porous particles is reported. Under optimal conditions, a separation of monoclonal IgG2 disulfide isomers was achieved in 10 min using a Poroshell™ 300SB‐C8 column via a combination of high column temperature (85°C), mobile phases with high eluotropic strength (e.g. isopropanol) and high flow rate (1.5 mL/min). Thermodynamic stability analyses of chromatographically enriched IgG2 disulfide isomers revealed differences in their individual denaturation temperatures, which correlate with the observed temperature‐dependent refinement of peak profiles by reversed‐phase HPLC. This reversed‐phase HPLC method in conjunction with other orthogonal analytical techniques (e.g. capillary gel electrophoresis, peptide mapping, ion exchange chromatography, etc.) is being used to characterize disulfide isomers in the development of therapeutic IgG2 antibodies.
Infrared‐assisted extraction coupled with high‐performance liquid chromatography for simultaneous determination of eight active compounds in Radix Salviae miltiorrhizae
Authors: Chen Yile , Duan Gengli , Xie Meifen , Chen Bin , Li Yan
Published: August 2010

In this study, a novel infrared‐assisted extraction (IRAE) method, in which infrared radiation was employed to extract the active compounds from plant, was developed and coupled with HPLC for simultaneous determination of four phenolic acids and four diterpenoids in Radix Salviae miltiorrhizae (Chinese name Danshen). The extraction conditions of IRAE were optimized and the optimal conditions were as follows: extraction time of 15 min; extraction solvent of 70% v/v methanol in water solution, and solid/liquid ratio of 0.1:15 (g/mL). Chromatography was performed on a 200 mm×4.6 mm id, 5‐μm particle size, C18 column. Good linearity (r>0.9994) was observed over the concentration ranges investigated, and intra‐day and inter‐day precision were high. Recoveries of the eight compounds were from 96.90 to 104.30% and RSD was below 2.5%. By using this novel IRAE method, with a shorter extraction time, the determined amounts of the eight active components in Danshen were comparable with or even higher than those extracted with conventional heat‐reflux extraction and ultrasound‐assisted extraction methods and microwave‐assisted extraction. The developed IRAE method is simple, low‐cost and efficient, offering a great promise for quick determination of active compounds in natural plants.
Development of the fingerprint for the quality of Radix Linderae through ultra‐pressure liquid chromatography‐photodiode array detection/electrospray ionization mass spectrometry
Authors: Wu Yong‐jiang , Zheng Yun‐liang , Luan Lian‐jun , Liu Xue‐song , Han Zheng , Ren Yi‐ping , Gan Li‐she , Zhou Chang‐xin
Published: August 2010

An ultra‐pressure LC (UPLC) method has been developed and validated for the quality evaluation of a traditional Chinese medicine (Radix Linderae) by chemical fingerprint analysis with chromatograms collected at two wavelengths (260 and 320 nm). Eleven characteristic peaks in the fingerprints were identified by comparing their retention times, UV spectra and ESI‐MS/MS data with those of the reference substances or the data in the literatures. Both correlation coefficient of similarities in chromatograms and relative peak areas of common peaks were calculated for quality expression of the Radix Linderae samples collected from different areas in China. The results showed high variation of relative peak area and correlation coefficients among the samples collected from various habitats, which indicated that the quality consistency of Radix Linderae is still a problem worthy of serious concern.
Rapid analysis of procyanidins and anthocyanins in plasma by microelution SPE and ultra‐HPLC
Authors: Martí Maria‐Pilar , Pantaleón Albert , Rozek Aleksandra , Soler Aranzazu , Valls Josep , Macià Alba , Romero Maria‐Paz , Motilva Maria‐José
Published: August 2010

In the analysis of biological samples, such as plasma or serum, the quantity of sample available is a critical parameter in most cases. A good approach is the use of the microelution SPE (μSPE) plates as sample pre‐treatment technique in which the loaded sample volume is low. An off‐line μSPE and ultra‐performance LC‐ESI‐MS/MS (UPLC‐ESI‐MS/MS) method was developed and validated to determine procyanidins and anthocyanins in spiked plasma samples. The sample pre‐treatment μSPE allowed the simultaneous determination of procyanidins and anthocyanins from plasma by using a small sample volume (350 μL) and without an evaporation step previous to the chromatographic analysis. Moreover, the use of UPLC technique allowed to determine the studied compounds at low concentration levels in a short analysis time (12.5 min approximately). Then, the developed method was applied to determine the studied compounds, procyanidins and anthocyanins, and their metabolites in rat plasma samples. Previously, the rats had consumed 5000 mg/kg of a grape pomace extract and the plasma was extracted 4 h after administration. The procyanidins catechin and epicatechin glucuronide, methyl catechin and epicatechin glucuronide, and methyl catechin and epicatechin sulphate were detected at μM concentration level, and the parent anthocyanins at nM.
High‐performance liquid chromatographic determination and pharmacokinetic study of cefepime in goat plasma and milk after pre‐column derivatization with Hg(I)
Authors: El‐Rabbat Nawal A. , Abdel‐Wadood Hanaa M. , Sayed Mohammed , Mousa Heba S.
Published: August 2010

A highly sensitive and selective HPLC method with UV detection was developed for the determination of cefepime in goat plasma and milk. The proposed method was based on the complexation of cefepime with Hg(I) ions that imparts the high selectivity of the proposed method with enhancement of the sensitivity which enabled the analysis of cefepime in complex matrices such as plasma and milk. Detection was performed at 263 nm, using cefuroxime sodium as an internal standard. Chromatographic separation of cefepime and the internal standard was achieved with Aqua RP‐C18column using methanol/triethylamine‐acetate buffer, pH 3.5 (18:82, v/v) as mobile phase at a flow rate of 1 mL/min. Linear detector responses were observed spanning the range of 1.3–20 μg/mL. The LOD for standard cefepime was 0.43 μg/mL, whereas the LOD for cefepime in goat plasma was 0.84 μg/mL and the corresponding value in goat milk was 1.1 μg/mL. No interference from endogenous substances in plasma and milk was observed. The developed HPLC method has been successfully applied for the pharmacokinetic study of cefepime in goat plasma and milk, for the first time, after a single intramuscular injection of 50 mg cefepime/kg body weight.
Solvent gradient elution for comprehensive separation of constituents with wide range of polarity in Apocynum venetum leaves by high‐speed counter‐current chromatography
Authors: Zhang Yuchi , Liu Chunming , Zhang Zhengkun , Qi Yanjuan , Wu Guimei , Li Sainan
Published: August 2010

A novel gradient elution was efficiently utilized for the separation of the chemical components with a wide range of polarity from the mixed extract of the Chinese medicinal herb Apocynum venetum or mixed standards by high‐speed counter‐current chromatography. Three sets of solvent systems, n‐hexane–ethyl acetate–methanol–water (1.5:3.5:2:4.5 v/v/v/v), ethyl acetate–methanol–water (5:2:5 v/v/v) and n‐butanol–methanol–water (5:1:5 v/v/v) were used for the one‐step elution. The separation was initiated by filling the column with the lower phase of n‐hexane–ethyl acetate–methanol–water (1.5:3.5:2:4.5 v/v/v/v) as a stationary phase followed by elution with the upper phase of n‐hexane–ethyl acetate–methanol–water (1.5:3.5:2:4.5 v/v/v/v) to separate the hydrophobic compounds (tail to head). Then the mobile phase was switched to the upper phase of ethyl acetate–methanol–water (5:2:5 v/v/v) to elute the moderate hydrophobic compounds, and finally the hydrophilic compounds still retained in the column were fractionated by eluting the column with the upper phase of n‐butanol–methanol–water (5:1:5 v/v/v). A total of 13 compounds including adhyperforin, hyperforin, amentoflavone, biapigenin, quercetin, astragalin, trifolin, isoquercetin, hyperside, acetyled hyperside, rutin, chlorogenic acid and quercetin‐3‐O‐β‐D‐glucosyl‐β‐D‐glucopyranoside were successfully separated via the three sets of solvent systems in one‐step operation for 90 min.
Toward high‐throughput drug screening on a chip‐based parallel affinity separation platform
Authors: Ohlson Sten , Duong‐Thi Minh‐Dao , Bergström Maria , Fex Tomas , Hansson Lennart , Pedersen Lennart , Guazotti Sergio , Isaksson Roland
Published: August 2010

High‐throughput screening of compound libraries, including the study of fragments, has become one of the cornerstones in modern drug discovery research. During this process hits are defined that may be developed into valuable leads and eventually into possible drug candidates. In this paper, we have demonstrated that parallel zonal weak affinity chromatography in microcolumns on a chip offers a possible screening format for weakly binding ligands toward a protein target. We used albumin as a model system because this transport protein is well established as a binder (both weak and strong) for drug substances. Bovine serum albumin was immobilized on microparticulate diolsilica particles and then packed into a 24‐channel cartridge, which served as the separation platform. Analysis of the obtained chromatograms yielded information about affinity even in the millimolar range. Employing this approach, thousands of substances can be screened in just a day. We feel confident that zonal affinity chromatography will provide a useful technology in the future for performing high‐throughput screening.
Pressurized liquid extraction followed by LC‐ESI/MS for analysis of four chromones in Radix Saposhnikoviae
Authors: Li Wei , Wang Zi , Chen Li , Zhang Jing , Han Likun , Hou Jingang , Zheng Yinan
Published: August 2010

An efficient pressurized liquid extraction (PLE) technique was employed in extracting chromones from the roots of Saposhnikovia divaricata (Radix Saposhnikoviae). Chromones were quantified and analyzed by LC‐ESI/MS. The PLE procedure was optimized, validated and compared with the other conventional extraction techniques. PLE gained the best result due to the highest extraction efficiency within the shortest extraction time. The optimal conditions of PLE were employing 50% ethanol as the extraction solvent at a temperature of 140°C and an extraction pressure of 1500 psi, using one extraction cycle with a static extraction time of 8 min. A good LC separation was achieved using a Hypersil ODS2 column and methanol/water as the mobile phase at a flow rate of 0.8 mL/min. MS coupling with an ESI interface in the positive ion mode was used as the detection technique. This is the first report on combining PLE with LC‐ESI/MS for the extraction and quantification of chromones in Radix Saposhnikoviae. The elaborated PLE method also provided a good alternative for the chromone extraction from other plant substances.
Characterization of stationary phases by a linear solvation energy relationship utilizing supercritical fluid chromatography
Authors: Mitchell Clifford R. , Benz Nancy J. , Zhang Shuhong
Published: August 2010

Supercritical fluid chromatography was utilized in combination with the Abraham model of linear solvation energy relationship to characterize 11 different HPLC stationary phases. System constants were determined at one supercritical fluid chromatography condition for each stationary phase. The results indicate that several types of silica columns, including type B silica, type C silica, and fused core silica, are very similar in their retention behavior. Several aromatic stationary phases were characterized and it was found that, in contrast to the other phases studied, all of the aromatic stationary phases had positive contributions from the dispersion/cavity (v) term of the linear solvation energy relationship. Several aliphatic phases were characterized and there were several linear solvation energy relationship constants that differentiated the phases from each other, mainly the polar terms (dipolarity and hydrogen bonding). One stationary phase, a fused core pentafluorophenyl (PFP) phase, had very poor regression quality. The column volume of this phase was lower than the others in the study, which may have had some impact on the results of the regression.
Plasma metabolomics reveals biomarkers of the atherosclerosis
Authors: Chen Xi , Liu Lian , Palacios Gustavo , Gao Jie , Zhang Ning , Li Guang , Lu Juan , Song Ting , Zhang Yingzhi , Lv Haitao
Published: August 2010

Atherosclerotic cardiovascular disease remains the leading cause of morbidity and mortality in industrialized societies. The lack of metabolite biomarkers has impeded the clinical diagnosis of atherosclerosis so far. In this study, stable atherosclerosis patients (n=16) and age‐ and sex‐matched non‐atherosclerosis healthy subjects (n=28) were recruited from the local community (Harbin, P. R. China). The plasma was collected from each study subject and was subjected to metabolomics analysis by GC/MS. Pattern recognition analyses (principal components analysis, orthogonal partial least‐squares discriminate analysis, and hierarchical clustering analysis) commonly demonstrated plasma metabolome, which was significantly different from atherosclerotic and non‐atherosclerotic subjects. The development of atherosclerosis‐induced metabolic perturbations of fatty acids, such as palmitate, stearate, and 1‐monolinoleoylglycerol, was confirmed consistent with previous publication, showing that palmitate significantly contributes to atherosclerosis development via targeting apoptosis and inflammation pathways. Altogether, this study demonstrated that the development of atherosclerosis directly perturbed fatty acid metabolism, especially that of palmitate, which was confirmed as a phenotypic biomarker for clinical diagnosis of atherosclerosis.
A reliable isotope dilution method for simultaneous determination of fumonisins B1, B2 and B3 in traditional Chinese medicines by ultra‐high‐performance liquid chromatography‐tandem mass spectrometry
Authors: Han Zheng , Ren Yiping , Liu Xuesong , Luan Lianjun , Wu Yongjiang
Published: August 2010

A reliable isotope dilution method for simultaneous determination of fumonisin B1, fumonisin B2 and fumonisin B3 in traditional Chinese medicines by ultra‐high‐performance LC‐MS/MS was developed, and a special focus was placed on the optimization of extraction, cleanup, ultra‐high‐performance LC separation and MS/MS conditions. Homogenized samples were extracted by 50% acetonitrile aqueous solution and purified with MultiSep 211 Fum columns. A linear gradient mobile phase, consisting of water containing 0.2% formic acid and acetonitrile/methanol (50:50 v/v) and an Acquity UPLC HSS T3 column (100 mm×2.1 mm, 1.8 μm) were employed to obtain the best resolution of the analytes for the positive ESI+ analysis. The established method was validated by determining the linearity (R2≥0.9991), sensitivity (LOQ, 0.08–0.16 ng/mL), recovery (88.2–113.3%) and precision (RSD≤12.3%). Finally, the validated method was successfully applied to the determination of fumonisins in different traditional Chinese medicines. Of 35 samples, 18 were contaminated with fumonisins. The mean levels (incidence) of fumonisin B1, fumonisin B1 and fumonisin B1 in positive samples were 8.55 (94.4%), 4.88 (77.8%) and 0.52 μg/kg (33.3%), respectively. Based on the contaminant situations, a possible association between the contamination levels and the selected herbs was clarified in this study.
Salinisation in Bulgaria: Institutional settings for soil conservation (a case study of Belozem village)
Authors: Penov I. , Manolov I. , Alexiev A. , Kavardziev Y.
Published: August 2010

Soil salinisation is one of the major soil degradation problems for Southern European countries and global warming is expected to increase the threat of secondary salinisation. This paper investigates salinisation in the village of Belozem, Bulgaria. The central argument is that the technical solutions and policy measures need to be backed up by appropriate institutional settings. This paper focuses on the natural and institutional factors involved. Further, it examines the causes driving the current salinisation process in this village. It is based on data collected by means of interviews with local people, and analysis of the existing farming practices and policy. The paper concludes that the new institutional settings do not support the technical decisions implemented in the past, and the implementation of possible new technical measures. The findings of this paper could provide lessons for land conservation policy that may apply beyond the case study region. The implementations of technical solutions need to be supported by appropriate institutions. The formal legislation and the incentive measures might not have the desired impact if cooperation among all participants is not sufficient or if farmers are discouraged from applying because of difficult application procedures. Copyright © 2010 John Wiley & Sons, Ltd.
Patients with chronic hepatitis C undergoing watchful waiting: Exploring trajectories of illness uncertainty and fatigue
Authors: Bailey Donald E. , Barroso Julie , Muir Andrew J. , Sloane Richard , Richmond Jacqui , McHutchison John , Patel Keyur , Landerman Lawrence , Mishel Merle H.
Published: August 2010

We identified trajectories of illness uncertainty in chronic hepatitis C patients and examined their association with fatigue levels during 12 months of disease monitoring without treatment (watchful waiting). Sixty‐two men and 63 women completed uncertainty and fatigue measures. Groups were formed by uncertainty scores (high, medium, and low) at baseline. Baseline fatigue levels were higher in the high uncertainty group than in the medium and low groups. Over time, uncertainty levels did not change. Fatigue levels in the low uncertainty group remained constant, increased in the medium, and decreased in the high groups. Findings suggest that uncertainty and fatigue do not remit spontaneously. Being aware of this may help nurses identify those patients needing support for these two concerns. © 2010 Wiley Periodicals, Inc. Res Nurs Health 33:465–473, 2010
Imaging mass spectrometry of myxoid sarcomas identifies proteins and lipids specific to tumour type and grade, and reveals biochemical intratumour heterogeneity
Authors: Willems Stefan M , van Remoortere Alexandra , van Zeijl René , Deelder André M , McDonnell Liam A , Hogendoorn Pancras CW
Published: August 2010

Myxofibrosarcoma and myxoid liposarcomas are relatively common soft tissue tumours that are characterized by their so‐called myxoid extracellular matrix and have to some extent overlap in histology. The exact composition and potential role of their myxoid extracellular matrix are insufficiently understood. To gain more insight into the biomolecular content of these tumours, we have studied 40 well‐documented myxofibrosarcoma and myxoid liposarcoma cases using imaging mass spectrometry. This technique provides a multiplex biomolecular imaging analysis of the tissue, spanning multiple molecular domains and without a priori knowledge of the tissue's biomolecular content. We have developed experimental protocols for analysing the peptide, protein, and lipid content of myxofibrosarcoma and myxoid liposarcomas, and have detected proteins and lipids that are tumour‐type and tumour‐grade specific. In particular, lipid changes observed in myxoid liposarcomas could be related to pathways known to be affected during tumour progression. Unsupervised clustering of the biomolecular signatures was able to classify myxofibrosarcoma and myxoid liposarcomas according to tumour type and tumour grade. Closer examination of histologically similar regions in the tissues revealed intratumour heterogeneity, which was a consistent feature in each of the myxofibrosarcomas studied. In intermediate‐grade myxofibrosarcoma, it was found that single tissue sections could contain regions with biomolecular profiles similar to high‐grade and low‐grade tumours, and that these regions were associated with the tumour's nodular structure, thus supporting a concept of tumour progression through clonal selection. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Attitudes of pregnant women regarding termination of pregnancy for fetal abnormality
Authors: Souka A. P. , Michalitsi V. D. , Skentou H. , Euripioti H. , Papadopoulos G. K. , Kassanos D. , Messinis I. E. , Salamalekis E. E
Published: August 2010

Objective

To study the attitudes of pregnant women towards termination of pregnancy for fetal abnormality.

Materials and methods

A questionnaire was completed by all pregnant women attending routine ultrasound scan. They were asked whether they would opt for termination of the pregnancy in case the fetus was diagnosed with one of the following abnormalities: lethal anomaly, anomaly causing developmental delay, anomaly causing physical handicap, anomaly causing disfigurement and severe anomaly diagnosed after 24 weeks of pregnancy. Logistic regression analysis was used to examine the effect of a variety of demographic and socio‐economic characteristics in their choices.

Results

A total of 533 women completed the questionnaire out of which 447 (86%) would terminate the pregnancy in case of lethal fetal anomaly. The corresponding figures for anomaly causing developmental delay, anomaly causing physical handicap and anomaly causing disfigurement were 396 (77.8%), 332 (65.9%) and 228 (45.2%). A total of 313 (64.7%) would request late termination owing to severe anomaly. The only two statistically significant factors that influenced the maternal decision on pregnancy termination were religious beliefs and the frequency of practicing religious duties (p < 0.001).

Conclusion

The majority of pregnant women would terminate pregnancy for lethal fetal anomaly and for an anomaly causing mental or physical handicap, even in late pregnancy. Copyright © 2010 John Wiley & Sons, Ltd.