bluuebunny/crossref_metadata_2025 huggingface dataset:
Gonadotropin-Releasing Hormone Promotes Ovarian Cancer Cell Invasiveness through c-Jun NH2-Terminal Kinase–Mediated Activation of Matrix Metalloproteinase (MMP)-2 and MMP-9
Authors: Cheung Lydia W.T. , Leung Peter C.K. , Wong Alice S.T.
Published: November 2006

Gonadotropin-releasing hormone (GnRH) receptor is present in 80% of ovarian cancer, and numerous studies have provided evidence for a role of GnRH in cell proliferation. In this study, the effect of GnRH on the invasion potential of ovarian cancer cells was investigated. In vitro migration and cell invasion assays with the ovarian cancer cell lines Caov-3 and OVCAR-3 revealed the biphasic nature of GnRH; low concentrations of GnRH agonist (GnRHa) increased the cell motility and invasiveness of these cells, but at increased concentrations, the stimulatory effect was insignificant. Reverse transcription-PCR, Western blot, and gelatin zymography showed that the expression of metastasis-related proteinases, matrix metalloproteinase (MMP)-2 and MMP-9, was up-regulated and activated by GnRHa. Moreover, we observed that GnRHa was able to transactivate the MMP-2 and MMP-9 promoters. The invasive/migratory phenotype activated by GnRHa can be blocked by specific inhibitors or neutralizing antibodies to MMP-2 and MMP-9. Knockdown of the GnRH receptor using small interfering RNA significantly inhibited the GnRH-induced MMP activation, invasion, and migration. In addition, we showed that the c-Jun NH2-terminal kinase, but not extracellular signal-regulated kinase 1/2 or p38 mitogen-activated protein kinase, signaling pathway was critical for GnRH-mediated up-regulation of MMP, cell invasion, and motility. These results indicate for the first time an expanded role for GnRH in other aspects of ovarian tumor progression, such as metastasis, via activation of MMP and the subsequent increase in cell migration and invasion. (Cancer Res 2006; 66(22): 10902-10)
Up-regulation of Expression of the Ubiquitin Carboxyl-Terminal Hydrolase L1 Gene in Human Airway Epithelium of Cigarette Smokers
Authors: Carolan Brendan J. , Heguy Adriana , Harvey Ben-Gary , Leopold Philip L. , Ferris Barbara , Crystal Ronald G.
Published: November 2006

Neuroendocrine differentiation is a common feature of lung cancer and increased numbers of neuroendocrine cells and their peptides have been described in chronic smokers. To understand the effects of cigarette smoking on the gene expression profile of neuroendocrine cells, microarray analysis with TaqMan confirmation was used to assess airway epithelial samples obtained by fiberoptic bronchoscopy from 81 individuals [normal nonsmokers, normal smokers, smokers with early chronic obstructive lung disease (COPD), and smokers with established COPD]. Of 11 genes considered to be neuroendocrine cell specific, only ubiquitin carboxyl-terminal hydrolase L1 (UCHL1), a member of the ubiquitin proteasome pathway, was consistently up-regulated in smokers compared with nonsmokers. Up-regulation of UCHL1 at the protein level was observed with immunohistochemical analysis of bronchial biopsies of smokers compared with nonsmokers. UCHL1 expression was evident only in neuroendocrine cells of the airway epithelium in nonsmokers; however, UCHL1 was also expressed in ciliated epithelial cells in smokers. This observation may add further weight to recent observations that ciliated cells are capable of transdifferentiating to other airway epithelial cells. In the context that UCHL1 is involved in the degradation of unwanted, misfolded, or damaged proteins within the cell and is overexpressed in >50% of lung cancers, its overexpression in chronic smokers may represent an early event in the complex transformation from normal epithelium to overt malignancy. (Cancer Res 2006; 66(22): 10729-40)
Germ-Line Genetic Variation in the Key Androgen-Regulating Genes Androgen Receptor, Cytochrome P450, and Steroid-5-α-Reductase Type 2 Is Important for Prostate Cancer Development
Authors: Lindström Sara , Wiklund Fredrik , Adami Hans-Olov , Bälter Katarina Augustsson , Adolfsson Jan , Grönberg Henrik
Published: November 2006

Prostate cancer risk may be influenced by single genetic variants in the hormone-regulating genes androgen receptor (AR), cytochrome P450 (CYP17), and steroid-5-α-reductase type 2 (SRD5A2). In this study, we comprehensively investigated polymorphisms in these three loci and their joint effect in a large population-based study. We selected 23 haplotype-tagging single-nucleotide polymorphisms (htSNP) that could uniquely describe >95% of the haplotypes (6 in AR, 6 in CYP17, and 11 in SRD5A2). These htSNPs were then genotyped in the Cancer Prostate in Sweden population (2,826 case subjects and 1,705 controls). We observed significant association for several SNPs in the AR gene (P = 0.004-0.02) and CYP17 (P = 0.009-0.05) and one SNP in SRD5A2 (P = 0.02). Carriers of the most common AR haplotype had a significant excess risk to develop prostate cancer [odds ratio (OR), 1.25; 95% confidence interval (95% CI), 1.1-1.5; P = 0.002], yielding an estimated population attributable risk of 16% (95% CI, 0.06-0.25). Combining risk alleles from these genes yielded a 12% risk increase for each additional high-risk allele carried (95% CI, 1.1-1.2; P for trend = 9.2 × 10−5), with an overall OR of 1.87 (95% CI, 1.0-3.4) for carriers of all five included risk alleles, an OR of 2.13 (P for trend = 8 × 10−4) for advanced disease, and an OR of 4.35 (P for trend = 7 × 10−5) for disease onset before age 65 years. Genetic variation in key genes in the androgen pathway is important for development of prostate cancer and may account for a considerable proportion of all prostate cancers. Carriers of five high-risk alleles in the AR, CYP17, and SRD5A2 genes are at ∼2-fold excess risk to develop prostate cancer. (Cancer Res 2006; 66(22): 11077-83)
Les smectites latées du domaine Atlantique depuis le Jurassique superieur: gisement et signification
Authors: Holtzapffel T. , Chamley H.
Published: November 2006

Resume

L'étude concerne 225 échantillons d'âge Jurassique à actuel de l'Océan Atlantique. La comparaison de l'abondance des smectites lattées, estimée sur micrographies électroniques, et de divers paramètres des sédiments, apporte des informations nouvelles sur la genèse et la signification de ces minéraux dans des sédiments non volcanoclastiques et non remainés. L'élaboration des smectites lattées par recristallisation diagénétique de smectites détritiques est favorisée lorsque la microperméabilité du sédiment est réduite (argiles fibreuses et particules calcaires, surtout les foraminifères, peu abondantes); lorsque les échanges chimiques à bilan constant avec le milieu interstitiel sont facilités (smectites abondantes) et lorsque la vitesse de dépôt est faible à moyenne. Dans les autres cas, la recristallisation de smectites lattées est très réduite ou absente. L'identification de ces minéraux dans les sédiments permet de préciser les conditions paléogéographiques de dépôt. La rareté des smectites lattées au Plio—Quaternaire pourrait être liée à l'extension des grands refroidissements mondiaux du climat.
The determination of layer charge by curve-fitting of Lorentz- and polarization-corrected X-ray diagrams
Authors: Stanjek H. , Friedrich R.
Published: November 2006

The clay fraction from the B horizon of a Psammentic Hapludalf containing vermiculite and smectite was treated with n-alkylammonium chloride ranging from nc = 6 to nc = 16. X-ray data were obtained by step-scanning, stored in a computer, corrected with the Lorentz and polarization factors and then fitted with a deconvolution programme. The layer charge was determined from the uncorrected, the corrected and the fitted diagrams, respectively. The evaluated confidence limits of ξ decreased in the same order revealing the vermiculite to be a high-charge type. The computed charge distribution of the smectite changed from an unlikely bimodal to a nearly symmetrical distribution.
Facies-related diagenesis in the Main Claymore Oilfield sandstones
Authors: Spark I. S. C. , Trewin N. H.
Published: November 2006

Four major sedimentary sequences of the Triassic and Upper Jurassic of the Main Claymore Oilfield of the North Sea each contain a characteristic suite of diagenetic minerals and fabrics. (1) Triassic Skagerrak Formation fluvial sandstones contain early authigenic pore-lining smectite, together with kaolinite and chlorite which form grain replacements and pore fills. Quartz and feldspar overgrowths are minor. Ferroan dolomite forms a late diagenetic patchy poikilotopic cement. Smectite is converted to illite-smectite in a 5 m thick zone beneath the sub-Jurassic unconformity. Smectite formed early in diagenesis prior to oil migration and destroyed permeability. Thus oil is not found in these sandstones although they occur in the oilzone. (2) The Piper Formation (late Oxfordian/early Kimmeridgian) paralic deposits mainly contain authigenic, pore-lining illite-smectite, vermicular kaolinite grain replacements and pore fills. Quartz overgrowths are generally well developed. (3) The Kimmeridge Clay Formation (early Kimmeridgian/early Volgian) comprises thin marine sandstone turbidites, contained within a thick siltstone/shale sequence. In the sandstones (the ‘Ten Foot Sandstone’) discrete double-ended quartz crystals (1–20 µm) developed prior to quartz, K- and Na-feldspar overgrowths. Only minor kaolinite and lllite-smectite are present. Late diagenetic dolomitic occurs as a patchy poikilotopic cement and as clusters of pore-filling rhombs. (4) The Claymore Sandstone Member (early to middle Volgian) thick marine sandstone turbidites are interbedded with thin siltstones/shales. Sandstones have well-developed quartz, K and Na-feldspar overgrowths, and kaolinite and illite-smectite occur as grain replacements and rarely as pore fills. Late-diagenetic dolomite and ferroan dolomite form poikilotopic cement and clusters of pore-filling rhombs. The major factors which control diagenetic features are depositional environment and associated porewater together with original mineralogy. Burial history and textural features of the sandstones also have important influences. Reservoir quality is controlled by a complex interplay of these features.
Measurement of the surface free energy of calcium-montmorillonite
Authors: Chassin P. , Jounay C. , Quiquampoix H.
Published: November 2006

The surface free energy of Ca-montmorillonite has been determined from measurement of the contact angle of water on an oriented deposit immersed in n-alkanes; the oriented deposits were equilibrated at different relative humidities. These experiments provided the polar, γSP, and dispersive, γSD, components of the surface free energy γs. The results indicate that: (1) γs is mainly due to dispersive forces (γSD ≃ 145 mJ.m−2) and, to a lesser degree, polar forces (γSP ≃ 35 mJ.m−2). (2) The value of the apparent surface free energy of the clay, γα, tends towards that measured for water when the solid water content exceeds 50 wt%. (3) The sorption of water molecules substantially modifies the surface free energy of the solid; γs decreases from 180 mJ.m−2 to 60 mJ.m−2 when the water content increases from 0 to 50%. These results agree with other observations made on solids whose surface characteristics are similar to montmorillonite, i.e. micas, silicates and glasses. In addition, variations of γs with water content can be related to the hydration processes of smectites. Finally, these results show that the silicate no longer influences the surface properties when the montmorillonite water content exceeds 60%.
Occurrence, composition and radionuclide sorption characteristics of illite from a fractured granite pluton, Southeastern Manitoba, Canada
Authors: Kamineni D. C. , Ticknor K. V. , Vandergraaf T. T.
Published: November 2006

Low-dip fractures in the Lac du Bonnet granite pluton, SE Manitoba, contain abundant illite. Petrographic examination showed that the illite has three modes of occurrence: (i) alteration product of biotite, (ii) microfracture (< 1 mm width) filling, (iii) macrofracture (> 1 mm) filling. Microprobe analyses of these three types of illites in a single sample gave distinct compositional characteristics that defined an evolutionary trend, depicting Al2O3 enrichment, on an Al2O3−(K2O + Na2O)−(MgO + FeO) triangular diagram. White micas in the rock matrix adjacent to illite-bearing fractures have higher K and Al contents than all the three types of illites, implying that they formed under different conditions. The sorption of four radionuclides, 137Cs, 147Pm, 241Am and 90Sr, under oxic conditions on illite-bearing polished sections was also investigated, using autoradiography combined with petrographic examination. Illite showed greater sorption compared with other minerals present in the polished sections.
Short-wavelength sensitive opsin (SWS1) as a new marker for vertebrate phylogenetics
Authors: van Hazel Ilke , Santini Francesco , Müller Johannes , Chang Belinda SW
Published: November 2006

Background

Vertebrate SWS1 visual pigments mediate visual transduction in response to light at short wavelengths. Due to their importance in vision, SWS1 genes have been isolated from a surprisingly wide range of vertebrates, including lampreys, teleosts, amphibians, reptiles, birds, and mammals. The SWS1 genes exhibit many of the characteristics of genes typically targeted for phylogenetic analyses. This study investigates both the utility of SWS1 as a marker for inferring vertebrate phylogenetic relationships, and the characteristics of the gene that contribute to its phylogenetic utility.

Results

Phylogenetic analyses of vertebrate SWS1 genes produced topologies that were remarkably congruent with generally accepted hypotheses of vertebrate evolution at both higher and lower taxonomic levels. The few exceptions were generally associated with areas of poor taxonomic sampling, or relationships that have been difficult to resolve using other molecular markers. The SWS1 data set was characterized by a substantial amount of among-site rate variation, and a relatively unskewed substitution rate matrix, even when the data were partitioned into different codon sites and individual taxonomic groups. Although there were nucleotide biases in some groups at third positions, these biases were not convergent across different taxonomic groups.

Conclusion

Our results suggest that SWS1 may be a good marker for vertebrate phylogenetics due to the variable yet consistent patterns of sequence evolution exhibited across fairly wide taxonomic groups. This may result from constraints imposed by the functional role of SWS1 pigments in visual transduction.
Conducting a Soft First-Story Multifamily Dwelling Survey: An Example Using Santa Clara County, California
Authors: Vukazich Steven M. , Selvaduray Guna , Tran Jessica
Published: November 2006

The objective of this survey was to provide data to emergency managers in Santa Clara County on the number of soft first-story multifamily dwellings (MFD) located in their communities using a cost-effective town-gown partnership. Target areas of cities were found by identifying areas containing residential units of two or more stories that had four or more living units. The survey found that 2,630, or 36%, of the 7,391 MFD in Santa Clara County are of the soft first-story construction type. It was found that one out of every nine apartment units in Santa Clara County is located in a soft first-story building. It is estimated that approximately 83,000 persons could be affected in the event of a severe earthquake. Emergency managers were given maps indicating areas of high-, medium-, and low-volume clusters of soft first-story MFD in each city. Follow-up interviews found that the communities that contain 67% of the identified soft-story MFD are using the survey information in their post-earthquake planning.
Relative Performance of Kobe and Northridge WSMF Buildings
Authors: Maison Bruce F. , Kasai Kazuhiko , Ooki Yoji
Published: November 2006

Seismic behaviors of a five-story welded steel moment-frame (WSMF) office building in Kobe, Japan, and a six-story WSMF office building in Northridge, California, are compared. Both experienced earthquake damage (1995 Kobe and 1994 Northridge earthquakes, respectively). Computer models of the buildings are formulated, having the ability to simulate damage in terms of fractured moment connections. Analyses are conducted to assess building response during the earthquakes. The calibrated models are then analyzed using a suite of earthquake records to compare building performance under consistent demands. The Kobe building is found to be more rugged than the Northridge building. Analysis suggests it would experience much less damage than the Northridge building from shaking equivalent to 2,500-year earthquake for a generic Los Angeles site. Superior performance of the Kobe building is attributed to its relatively greater stiffness and strength. The results provide insight into the difference in seismic fragility expected for this class of mid-rise WSMF buildings in Japan and the United States.
Detection of SNPs in the Plasma of Pregnant Women and in the Urine of Kidney Transplant Recipients by Mass Spectrometry
Authors: LI YING , HAHN DEIRDRÉ , WENZEL FRIEDEL , HOLZGREVE WOLFGANG , HAHN SINUHE
Published: November 2006

Abstract:  Recently, it has been discovered that cell‐free fetal DNA is smaller than corresponding maternal DNA. Therefore, circulating fetal DNA can be enriched by size‐fractionation. Such a selection improves the non‐invasive prenatal diagnosis of paternally inherited single gene mutations. Recent studies showed that MALDI‐TOF mass spectrometry (MS) can be used to reliably detect fetal‐specific single‐nucleotide polymorphisms (SNPs) in maternal plasma. In this study, we looked at whether the size‐fractionation approach could improve the detection of paternally inherited SNPs by MS assay. Our results indicated that the size‐fractionation approach improved the analysis of paternally inherited SNP alleles. Our previous studies showed that donor‐derived STR sequences could be detected in the urine of kidney transplant recipients. Here, we also examined whether donor‐specific SNPs could be detected in recipient's urine by MS.
Concentrations of Circulating RNA from Healthy Donors and Cancer Patients Estimated by Different Methods
Authors: RYKOVA ELENA Y. , WUNSCHE WINFRIED , BRIZGUNOVA OLGA E. , SKVORTSOVA TATYANA E. , TAMKOVICH SVETLANA N. , SENIN ILIJA S. , LAKTIONOV PAVEL P. , SCZAKIEL GEORG , VLASSOV VALENTIN V.
Published: November 2006

Abstract:  Circulating RNA (cirRNA) was isolated from plasma and cell surface‐bound fractions of blood of healthy women and breast cancer patients. RNA samples were DNase treated and quantified by a SYBR Green II assay. Concentrations of RNA sequences of GAPDH, Ki‐67 mRNA, and 18S rRNA were measured by real‐time quantitative PCR (RT‐qPCR) after reverse transcription with random hexamer primers. The obtained data spread over three orders of magnitude for GAPDH and Ki‐67 mRNA signals and two orders of magnitude for the copy number of 18S rRNA in blood fractions in both groups. In blood of healthy donors, no correlation was found between the copy number of GAPDH, Ki‐67 mRNA, and 18S rRNA and RNA concentrations measured by the SYBR Green II assay. Within the group of breast cancer patients, the concentration GAPDH and Ki‐67 mRNA correlated with the concentration of total RNA only in the cell surface‐bound fraction; whereas the concentration of 18S rRNA correlated with total RNA in both, the cell surface‐bound fraction and blood. The copy number of Ki‐67 mRNA correlated with copy numbers of GAPDH mRNA in all fractions of cirRNA of healthy donors and breast cancer patients. A correlation between copy numbers of Ki‐67 mRNA and 18S rRNA was found only in cell surface‐bound fraction of breast cancer patients. The data described here demonstrate the necessity of searching for more suitable RNA markers in order to estimate total cirRNA concentrations by RT‐qPCR, although mRNA of GAPDH could be used for normalization of the level of cancer‐specific mRNA among patients.
The South European Orient: A Comparative Reflection on Space in Literary History
Authors: Domínguez César
Published: November 2006

César Domínguez is associate professor of comparative literature at the Universidade de Santiago de Compostela, Spain. He is author of El concepto de “materia” en la teoría literaria del Medievo (2004) and is at work on a book about literary geography.
Spliceosomal small nuclear RNA genes in 11 insect genomes
Authors: Mount Stephen M. , Gotea Valer , Lin Chiao-Feng , Hernandez Kristina , Makałowski Wojciech
Published: November 2006

The removal of introns from the primary transcripts of protein-coding genes is accomplished by the spliceosome, a large macromolecular complex of which small nuclear RNAs (snRNAs) are crucial components. Following the recent sequencing of the honeybee (Apis mellifera) genome, we used various computational methods, ranging from sequence similarity search to RNA secondary structure prediction, to search for putative snRNA genes (including their promoters) and to examine their pattern of conservation among 11 available insect genomes (A. mellifera, Tribolium castaneum, Bombyx mori, Anopheles gambiae, Aedes aegypti, and six Drosophila species). We identified candidates for all nine spliceosomal snRNA genes in all the analyzed genomes. All the species contain a similar number of snRNA genes, with the exception of A. aegypti, whose genome contains more U1, U2, and U5 genes, and A. mellifera, whose genome contains fewer U2 and U5 genes. We found that snRNA genes are generally more closely related to homologs within the same genus than to those in other genera. Promoter regions for all spliceosomal snRNA genes within each insect species share similar sequence motifs that are likely to correspond to the PSEA (proximal sequence element A), the binding site for snRNA activating protein complex, but these promoter elements vary in sequence among the five insect families surveyed here. In contrast to the other insect species investigated, Dipteran genomes are characterized by a rapid evolution (or loss) of components of the U12 spliceosome and a striking loss of U12-type introns.
Necdin Downregulates Cdc2 Expression to Attenuate Neuronal Apoptosis
Authors: Kurita Mitsumasa , Kuwajima Takaaki , Nishimura Isao , Yoshikawa Kazuaki
Published: November 2006

The cell cycle-regulatory transcription factor E2F1 induces apoptosis of postmitotic neurons in developmental and pathological situations. E2F1 transcriptionally activates many proapoptotic genes including the cyclin-dependent protein kinase cell division cycle 2 (Cdc2). Necdin is a potent mitotic suppressor expressed predominantly in postmitotic neurons and interacts with E2F1 to suppress E2F1-mediated gene transcription. The necdin geneNDNis maternally imprinted and expressed only from the paternal allele. Deletion of the paternalNDNis implicated in the pathogenesis of Prader-Willi syndrome, a genomic imprinting-associated neurodevelopmental disorder. Here, we show that paternally expressed necdin represses E2F1-dependentcdc2gene transcription and attenuates apoptosis of postmitotic neurons. Necdin was abundantly expressed in differentiated cerebellar granule neurons (CGNs). Neuronal activity deprivation elevated the expression of both E2F1 and Cdc2 in primary CGNs prepared from mice at postnatal day 6, whereas the necdin levels remained unchanged. In chromatin immunoprecipitation analysis, endogenous necdin was associated with thecdc2promoter containing an E2F-binding site in activity-deprived CGNs. After activity deprivation, CGNs underwent apoptosis, which was augmented in those prepared from mice defective in the paternal Ndn allele (Ndn+m/−p). The levels ofcdc2mRNA, protein, and kinase activity were significantly higher in Ndn+m/−pCGNs than in wild-type CGNs under activity-deprived conditions. Furthermore, the populations of Cdc2-immunoreactive and apoptotic cells were increased in the cerebellumin vivoof Ndn+m/−pmice. These results suggest that endogenous necdin attenuates neuronal apoptosis by suppressing the E2F1–Cdc2 system.
The Role of Protein Synthesis in Striatal Long-Term Depression
Authors: Yin Henry H. , Davis Margaret I. , Ronesi Jennifer A. , Lovinger David M.
Published: November 2006

Long-term depression (LTD) at the corticostriatal synapse is postsynaptically induced but presynaptically expressed, the depression being a result of retrograde endocannabinoid signaling that activates presynaptic cannabinoid CB1receptors and reduces the probability of glutamate release. To study the role of protein synthesis in striatal LTD, we used a striatum-only preparation in which the presynaptic cell body is cut off, leaving intact only its axons, whose terminals synapse on medium spiny neurons. LTD (duration >150 min) was induced in this preparation, thus providing evidence that transcription in the presynaptic cell nucleus is not necessary for this form of plasticity. The maintenance of striatal LTD, however, was blocked by bath application of protein translation inhibitors but not by the same inhibitors loaded into the postsynaptic cell. These results suggest that local translation is critical for the expression of striatal LTD, distinguishing this form of mammalian synaptic plasticity from other forms that require postsynaptic protein synthesis. Possible roles of axonal or glial translation in striatal LTD are considered.
Neoadjuvant Use of Hormonal Therapy in Elderly Patients with Early or Locally Advanced Hormone Receptor–Positive Breast Cancer
Authors: Macaskill E. Jane , Renshaw Lorna , Dixon J. Michael
Published: November 2006

The management of the elderly patient with breast cancer is a challenge to the breast care team for a number of reasons. The higher rate of comorbidity in elderly patients increases the risk for complications and mortality following surgery and other adjuvant treatments such as chemotherapy and radiotherapy. The advent of using endocrine therapy in the neoadjuvant setting allows disease control and downstaging of tumors to allow less extensive surgery, with less morbidity compared with other available treatments. Tamoxifen has traditionally been the hormone therapy of choice for patients unable to undergo surgery, but development of resistance is a common feature. Newer third-generation aromatase inhibitors, in particular letrozole, are superior to tamoxifen in this setting with greater downstaging of tumor and disease control. The aromatase inhibitors are now the treatment of choice in elderly patients with estrogen receptor–positive breast cancer who are being considered for neoadjuvant therapy. These drugs are particularly suitable to the needs of an elderly population.
Comparison of the performance of chitosan and a cationic polyacrylamide as flocculants of emulsion systems
Authors: Pinotti A. , Bevilacqua A. , Zaritzky N.
Published: November 2006

Food industries contribute significantly to the pollution of water streams. Oil in wasterwaters must be removed to prevent fouling of process equipment, to reduce interference with subsequent water‐treatment units, and to comply with water‐discharge requirements. Polyelectrolytes are frequently used to coagulate and flocculate colloidal systems. A model system of a sunflower oil/water emulsion was used to analyze the effect of:(i) emulsion droplet sizes, (ii) surfactant chain length (sodium dodecyl sulfate and sodium tetradecyl sulfate), (iii) ionic strength, and (iv) pH, on the doses of chitosan (natural cationic polyelectrolyte) and a cationic polyacrylamide, necessary to neutralize electrical charge and to get flocculation. Methods used were: turbidimetry, jar test, colloidal titration, and light microscopy observation. Results showed that the increase of NaCl concentration reduces the doses of chitosan and polyacrylamide to reach zero colloidal charge; these doses increase with the surfactant chain length. pH variation did not show any influence on the chitosan dose necessary to flocculate the system. Redispersion of the emulsion was observed in chitosan and polyacrylamide treatments.
Synthesis of enhanced biosurfactant by Bacillus subtilis MTCC 2423 at 45°C by foam fractionation
Authors: Makkar Randhir S. , Cameotra Swaranjit S.
Published: November 2006

Production of a lipopeptide surfactant in a 6.5‐L batch fermentor was carried out using Bacillus subtilis MTCC 2423 at 45°C. A good yield was obtained from sucrose (2%) substrate fermentation by continuous removal of the product by foam fractionation. The biosurfactant was recovered from collapsed foam by acid precipitation. The biosurfactant yield (4.5 g/L) was about 4.5 times higher than the yield (ca. 1 g/L) obtained by shake‐flask fermentation. Surface activity of the collapsed foam was very high, and total surface activity was observed in the collapsed foam. The structural characterization of this biosurfactant produced at 45°C by the strain used in this study was recently reported. The biosurfactant was analyzed by thin‐layer chromatography, infrared, 1H nuclear magnetic resonance, and mass spectroscopy and was found to be identical to surfactin, a lipopeptide surfactant.
Tethering of long‐chain amino acids to a rigid aromatic core—A new type of preorganized surfactants acting as flotative agents
Authors: Müller P. , Weber E. , Helbig C. , Baldauf H.
Published: November 2006

New oligofunctional surfactants prepared from ethyl 2‐aminododecanoate hydrochloride and positional isomers of aromatic acid di‐ and trichloridesviaamide bond formation, including also the monofunctional compound of comparison, have been synthesized. Surface properties of the new compounds, in particular critical micelle concentration (CMC), surface tension at the CMC, effectiveness, and maximum surface excess, were determined. Moreover, their effectiveness at flotation using the model mineral fluorite was studied. We found that the surfactant parameters clearly depend on the number and position of the amphiphilic subunits attached to the aromatic core. We also found that a bundling of amphiphilic subunits, as performed, is profitable in the flotation of fluorite and that effects of preorganization due to the proximity and geometric grouping of the amphiphilic subunits are of importance. As a rule, the more amphiphilic subunits are included in the surfactant structure, the more efficient is the collecting agent, involving approximate enhancements of fluorite flotation by powers of 10 when going from mono‐ to bi‐ and trifunctional surfactant analogs, respectively. Nevertheless, the surface properties of the newly synthesized surfactants do not directly correlate with the flotation data, which makes relations between surfactant structure and efficiency of fluorite flotation at the current stage of development difficult to determine. Future studies relating to this problem are suggested.
Solubilization of phospholipid vesicular structures into mixed micelles of zwitterionic surfactants
Authors: Sehgal Pankaj , Doe Hidekazu , Bakshi Mandeep Singh
Published: November 2006

Interactions between the binary combination of dimethyltetradecylammoniopropanesulfonate (TPS) and l‐α‐phosphatidylcholine (PC), 1,2‐didecanoyl‐sn‐glycero‐3‐phosphocholine, and 1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine in the aqueous bulk phase were evaluated with the help of pyrene fluorescence (l1/l3) measurements by studying the aggregation processes of TPS in pure water and in the presence of 7–36 μM of fixed concentrations of each lipid. The fluorescence measurements showed that TPS monomers undergo two kinds of aggregation process, which were identified by the three breaks. The first break, C1, and the second, C2, indicated the onset and completion of bilayer solubilization, respectively, on the incorporation of TPS monomers into the bilayer assemblies, which led to bilayer solubilization in the form of mixed micelles. This process was not clearly visible in the presence of PC, whereas some kinds of structure transitions were observed upon the incorporation of surfactant monomers. The partition coefficient (K), which defines the degree of partitioning of surfactant monomers into the bilayers with respect to the aqueous medium, was evaluated. A high K value of TPS‐lipid aggregates indicated stronger interactions between surfactant and bilayer assemblies of lipid. The K values determined for the three phospholipids are close to each other, which indicates that K values do not depend on the hydrocarbon chain length of the phospholipid but of the surfactant used.
Corrosion inhibition of some novel hydrazone derivatives
Authors: Negm Nabel A. , Morsy Salwa M. I. , Said Medhat M.
Published: November 2006

A novel series of surfactants was synthesized via direct interaction of the hydrogen‐accepting benzyl monophenyl hydrazone and different hydrogen‐donating sulfate, sulfonate, sulfosuccinate, or taurate species in their acid form. The double salt surfactants produced had a benzyl monophenyl hydrazonium (PH) moiety as the cation, and lauryl sulfate, dodecylbenzene sulfonate, dioctyl sulfosuccinate, N‐cetyloxycarbonyl ethyltaurate (COCET), and N‐stearyloxycarbonyl ethyltaurate as the anion. The structural elucidation of the synthesized compounds was carried out using different analytical tools such as elemental analyses, sharp melting points, and Fourier transform infrared and 1H nuclear magnetic resonance spectroscopy. Surface properties of these synthesized hydrazonium derivatives, including surface tension and emulsion stability, were measured and correlated with their chemical structure. The corrosion inhibition efficiency of these hydrazonium derivatives at different concentrations (20, 40, 60, 80, and 100 ppm) was measured in brine containing 5% H2S as the corrosive medium. The inhibition efficiency results were discussed according to the inhibitor concentrations in the corrosive medium, chemical structures, surface properties, and hydrophile‐lipophile balance of these inhibitors. The corrosion inhibition measurements of these compounds showed that PH‐COCET exhibits good efficiency at all concentration ranges.
The effects of anionic and cationic surfactants on the hydrolysis of sodium barbital
Authors: Qian Junhong , Qian Shaohua , Guo Rong
Published: November 2006

Alkaline hydrolysis reactions of sodium barbital in micelles of sodium dodecyl sulfate (the anionic surfactant SDS), micelles of cetyl trimethylammonium bromide (the cationic surfactant CTAB), and mixed micelles of surfactant/n‐C5H11OH/H2O were studied by ultraviolet‐visible spectrometry. The reaction rate and the activation energy of the hydrolysis of sodium barbital were calculated. The results showed that the rate of sodium barbital hydrolysis decreased with an increase in CTAB content, whereas it increased in the presence of SDS and n‐C5H11OH. The different effects of CTAB and SDS on the hydrolysis of sodium barbital may be related to their interaction with sodium barbital.
Corrosion inhibition of triethanolammonium bromide mono‐ and dibenzoate as cationic inhibitors in an acidic medium
Authors: Negm Nabel A. , Morsy Salwa M. I.
Published: November 2006

A weight loss technique was used to determine the corrosion inhibition efficiency of synthesized alkyl mono‐and dibenzoate triethanolammonium bromide derivatives (TEAMB, TEADB) in an acidic medium (2 N HCl) at different doses (50, 100, and 200 ppm). The results showed that monoderivatives had a higher corrosion inhibition efficiency than diderivatives. The results were correlated with several factors, including the alkyl chain length of the hydrophobic chains, interfacial tension (IT), critical micelle concentration (CMC), and adsorption free energy of these inhibitors. Increasing the geometric length of the alkyl chains in the synthesized inhibitors had an increasing effect on their corrosion inhibition efficiency, whereas decreasing the CMC and IT had an increasing effect on their tendency toward corrosion inhibition. The number of hydrophobic chains attached to the inhibitor molecules had a vital influence on their efficiency as corrosion inhibitors.
Synthesis, stability, and biodegradability studies of a surface‐active amide
Authors: Stjerndahl Maria , Holmberg Krister
Published: November 2006

A homolog pure nonionic surfactant, tetra(ethylene glycol) mono‐n‐octaneamide, was synthesized. The surfactant was characterized by determining the critical micelle concentration, cloud point, and biodegradation. Hydrolysis catalyzed by an acid, an alkali, a peroxide, and enzymes [peptidase from porcine, amidase from Pseudomonas aeruginosa, and two lipases, Mucor miehei lipase (MML) and Candida antarctica lipase B (CALB)] was investigated using 1H nuclear magnetic resonance. The surfactant was stable toward the acid, alkali, and peroxide. When subjected to peptidase and CALB, the amide was cleaved, although at a low rate. No reaction was obtained when using the amidase or MML. The biodegradation test resulted in more than 60% degradation after 28 d. Based on these results, the amide surfactant can be considered chemically stable, yet highly biodegradable, which generally is an ideal combination of properties for a surfactant.
Alpha‐sulfonated methyl ester as an active ingredient in palm‐based powder detergents
Authors: Maurad Zulina Abd , Ghazali Razmah , Siwayanan Parthiban , Ismail Zahariah , Ahmad Salmiah
Published: November 2006

Palm‐based alpha‐sulfonated methyl esters (SME) were successfully produced using a 20 kg/h‐capacity pilot plant at the Malaysian Palm Oil Board. This anionic surfactant was used as an active ingredient to formulate powder detergent. The production of palm‐based powder detergents (PPD) was carried out at the pilot‐plant scale. The performance of powder detergents formulated with SME was found to be excellent. At a total concentration of 0.8 g/L, good detergency of PPD was obtained when only using 12% to 18% SME, compared to the commercial detergent with 27% surface‐active agent. The foaming power and wetting characteristics of PPD were also comparable to the values for the commercial detergent. The study has shown that PPD were able to biodegrade faster than the commercial detergent, where the maximum time period to reach the pass level (60%) is within 14 days. The toxicity of the PPD, which ranged from 5.66 to 8.0 mg/L, is similar to the toxicity of the commercial detergent. A detailed description of the SME application technologies in powder detergents and the properties of formulated powder detergents are highlighted in this paper.
Biosurfactant production by microorganisms on unconventional carbon sources
Authors: Makkar Randhir S. , Cameotra Swaranjit S.
Published: November 2006

In recent years natural biosurfactants have attracted attention because of their low toxicity, biodegradability, and ecological acceptability. However, for reasons of functionality and production cost, they are not competitive with chemical surfactants. Use of inexpensive substrates can drastically decrease the production cost of biosurfactants. This review describes the use of unconventional carbon sources for biosurfactant production. These sources include urban as well as agroindustrial wastes. With suitable engineering and microbiological modifications, these wastes can be used as substrates for large‐scale production of biosurfactants.
Absorption of canthaxanthin by the rat is influenced by total lipid in the intestinal lumen
Authors: Clark Richard M. , Furr Harold C.
Published: November 2006

In this study the effect of luminal lipid on the absorption of canthaxanthin (CTX) was investigated using the lymph duct cannulated rat. Treatments were emulsions designed to deliver increasing amounts of olive oil (10, 30, 50, 70, or 90 mg/h) and CTX (12.5 nmol/h). Emulsions were continuously infused into the duodenum for 12 h, and lymph was collected during the final 6 h of infusion for analysis. As the amount of lipid in the emulsion increased, a linear increase in the absorption of CTX was observed. The recovery of CTX in the lymph when infused with 10 mg/h olive oil was 14.2±1.2% and with 90 mg/h was 26.9±5.7%. The efficiency of CTX absorption nearly doubled by increasing the amount of lipid infused with CTX. The correlation between lipid load and CTX absorbed was r=0.85. We conclude that luminal lipid load affects CTX absorption.
Influence of formulas with borage oil or borage oil plus fish oil on the arachidonic acid status in premature infants
Authors: Demmelmair Hans , Feldl Franziska , Horváth Imre , Niederland Tamás , Ruszinkó Viktória , Raederstorff Daniel , De Min Cristina , Muggli Reto , Koletzko Berthold
Published: November 2006

Several studies have reported that feeding γ‐linolenic acid (GLA) has resulted in no increase in arachidonic acid (AA) in newborns. This result was ascribed to the eicosapentaenoic acid (EPA)‐rich fish oil used in these formulas. Docosahexaenoic acid (DHA) sources with only minor amounts of EPA are now available, thus the addition of GLA to infant formulas might be considered an alternative to AA supplementation. Sixty‐six premature infants were randomized to feeding one of four formulas [ST: no GLA, no long‐chain polyunsaturated fatty acids; BO: 0.6% GLA (borage oil); BO + FOLOW: 0.6% GLA, 0.3% DHA, 0.06% EPA; BO + FOHIGH: 0.6% GLA, 0.3% DHA, 0.2% EPA] or human milk (HM, nonrandomized) for 4 wk. Anthropometric measures and blood samples were obtained at study entry and after 14 and 28 d. There were no significant differences between groups in anthropometric measures, tocopherol, and retinol status at any of the studied time points. The AA content of plasma phospholipids was similar between groups at study start and decreased significantly until day 28 in all formulafed groups, but not in the breast‐fed infants [ST: 6.6±0.2%, BO: 6.9±0.3%, BO + FOLOW: 6.9±0.4%, BO + FOHIGH: 6.7±0.2%, HM: 8.6±0.5%, where values are reported as mean ±standard error; all formulas significantly different (P≤0.05) from HM]. There was no significant influence of GLA or fish oil addition to the diet. GLA had only a very limited effect on AA status which was too small to obtain satisfactory concentrations (concentrations similar to breast‐fed babies) under the circumstances tested. The effect of GLA on AA is independent of the EPA and DHA content in the diet within the dose ranges studied.
Subcellular localization of oxidosqualene cyclases from Arabidopsis thaliana, Trypanosoma cruzi, and Pneumocystis carinii expressed in yeast
Authors: Milla P. , Viola F. , Bosso S. Oliaro , Rocco F. , Cattel L. , Joubert B. M. , LeClair R. J. , Matsuda S. P. T. , Balliano G.
Published: November 2006

Cycloartenol synthase from Arabidopsis thaliana and lanosterol synthase from Trypanosoma cruzi and Pneumocystis carinii were expressed in yeast, and their subcellular distribution in the expressing cells was compared. Determination of enzymatic (oxidosqualene cyclase, OSC) activity and SDS‐PAGE analysis of subcellular fractions proved that enzymes from T. cruzi and A. thaliana have high affinity for lipid particles, a subcellular compartment rich in triacylglycerols, and steryl esters, harboring several enzymes of lipid metabolism. In lipid particles of strains expressing the P. carinii enzyme, neither OSC activity nor the electrophoretic band at the appropriate M.W. were detected. Microsomes from the three expressing strains retained some OSC activity. Affinity of enzymes from A. thaliana and T. cruzi for lipid particles is similar to that of OSC of Saccharomyces cerevisiae, which is mainly located in this compartment. A different distribution of OSC in yeast cells suggests that they differ in some structural features critical for the interaction with the surface of lipid particles. Computer analysis supports the hypothesis of the structural difference since OSC from S. cerevisiae, A. thaliana, and T. cruzi lack or contain only one transmembrane spanning domain (a structural feature that makes a protein poorly inclined to associate with lipid particles), whereas OSC from P. carinii possesses six transmembrane domains. In the strain expressing cycloartenol synthase from A. thaliana, the accumulation of lipid particles largely exceeded that of the other strains.
Storage lipid accumulation and acyltransferase action in developing flaxseed
Authors: Sørensen Brent M. , Furukawa‐Stoffer Tara L. , Marshall Kris S. , Page Erin K. , Mir Zahir , Forster Robert J. , Weselake Randall J.
Published: November 2006

Investigations of storage lipid synthesis in developing flaxseed (Linum usitatissimum) provide useful information for designing strategies to enhance the oil content and nutritional value of this crop. Lipid content and changes in the FA composition during seed development were examined in two cultivars of flax (AC Emerson and Vimy). The oil content on a dry weight basis increased steadily until about 20 d after flowering (DAF). The proportion of α‐linolenic acid (α‐18∶3, 18∶3cisΔ9, 12, 15) in TAG increased during seed development in both cultivars while the proportions of linoleic acid (18∶2cisΔ9, 12) and saturated FA decreased. The developmental and substrate specificity characteristics of microsomal DAG acyltransferase (DGAT, Ec 2.3.1.20) and lysophosphatidic acid acyltransferase (LPAAT, EC 2.3.1.51) were examined using cultivar AC Emerson. The maximal acyltransferase specific activities occurred in the range of 8–14 DAF, during rapid lipid accumulation on a per seed basis. Acyl‐CoA of EPA (20∶5cisΔ5,8,11,14,17) or DHA (22∶6cis4,7,10,13,16,19) were included in the specificity studies. DGAT displayed enhanced specificity for α‐18∶3‐CoA, whereas the preferred substrate of LPAAT was 18∶2‐CoA. Both enzymes could use EPA‐ or DHA‐CoA to varying extents. Developing flax embryos were able to take up and incorporate these nutritional FA into TAG and other intermediates in the TAG‐formation pathway. This study suggests that if the appropriate acyl‐CoA‐dependent desaturation/elongation pathways are introduced and efficiently expressed in flax, this may lead to the conversion of α‐18∶3‐CoA into EPA‐CoA, thereby providing an activated substrate for TAG formation.
Immediate no‐flow ischemia decreases rat heart nonesterified fatty acid and increases acyl‐CoA species concentrations
Authors: Maoz Daniel , Lee Ho‐Joo , Deutsch Joseph , Rapoport Stanley I. , Bazinet Richard P.
Published: November 2006

Tissues changes in FA metabolism can occur quite rapidly in response to ischemia and may require immediate microwave fixation to determine basal concentrations. The present study aimed to quantify the effects of immediate no‐flow ischemia on concentrations of individual nonesterified FA (NEFA) and acyl‐CoA species in the rat heart. Male CDF 344 rats were anesthetized and decapitated either 5 min prior to being microwaved (5.5 kW, 3.4 s, twice) to produce ischemia or microwaved prior to decapitation (nonischemic). Hearts were then removed and used to measure the concentrations of acyl‐CoA species and FA in several lipid classes. The ischemic heart total NEFA concentration was significantly lower than that in the nonischemic heart (11.9 vs. 19.0 nmol/g). Several individual NEFA concentrations were decreased by 31–85%. Ischemic heart total long‐chain acyl‐CoA concentrations (21.0 nmol/g) were significantly higher than those in nonischemic hearts (11.4 nmol/g). Increased concentrations of individual acyl‐CoA species occurred in palmitoyl‐CoA, stearoyl‐CoA, oleoyl‐CoA, and linoleoyl‐CoA. Concentrations of short‐chain acetyl‐CoA and β‐hydroxy‐β‐methylglutaryl‐CoA were also two‐ to three‐fold higher in ischemic hearts than in nonischemic hearts. The FA concentration in TG and phospholipids generally did not differ between the groups. Decreases in concentrations of individual FA and increases in acyl‐CoA species during no‐flow ischemia occur very rapidly within the heart. Although it is not clear how these alterations contribute to the pathogenesis of ischemia, it is evident that future studies attempting to quantify basal levels of these metabolites could use microwave fixation.