bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of the V600D mutation in Exon 15 of the BRAF oncogene in congenital, benign langerhans cell histiocytosis
Authors: Kansal Rina , Quintanilla‐Martinez Leticia , Datta Vivekananda , Lopategui Jean , Garshfield Gary , Nathwani Bharat N.
Published: September 2012

Langerhans cell histiocytosis (LCH) is a well‐known but rare disease that may occur at any age with markedly variable clinical features: self‐regressive, localized, multiorgan, aggressive, or fatal outcome. Congenital LCH is rare and often clinically benign. While LCH is characterized by a clonal proliferation of Langerhans cells, its etiology is unknown. Although BRAF V600E mutations were recently identified as a recurrent genetic alteration in LCH cases, the clinical significance of this mutation within the heterogeneous spectrum of LCH is also currently unknown. We studied a cutaneous, benign form of congenital LCH that occurred in a newborn male, without recurrence for 8 years. Histopathologically, the skin lesion excised after birth showed the typical cytologic and immunophenotypic features of LCH. Sequencing analysis of Exon 15 of the BRAF gene revealed the V600D mutation, with an allelic abundance of 25–30%, corresponding to the LCH cells being hemizygous for the mutant allele. BRAF V600E‐specific polymerase chain reaction was negative. Our report is the first to identify the rare, variant BRAF V600D mutation in LCH, and provides support for constitutively activated BRAF oncogene‐induced cell senescence as a mechanism of regression in congenital, benign LCH. Further, our clinicopathologic findings provide proof for the first time that the V600D mutation can also occur in the absence of ultraviolet light, and can occur in a clinically benign proliferation, similar to the V600E mutation. Additional clinicopathologic studies in larger numbers of LCH patients may be valuable to ascertain the pathophysiologic role of BRAF mutations in LCH. © 2012 Wiley Periodicals, Inc.
Time limited immunomodulatory functions of transplanted neural precursor cells
Authors: Fainstein Nina , Einstein Ofira , Cohen Mikhal E. , Brill Livnat , Lavon Iris , Ben‐Hur Tamir
Published: September 2012

Fetal neural stem/precursor cells (NPCs) possess powerful immunomodulatory properties which enable them to protect the brain from immune‐mediated injury. A major issue in developing neural stem/precursor cell (NPC) therapy for chronic neuroinflammatory disorders such as multiple sclerosis is whether cells maintain their immune‐regulatory properties for prolonged periods of time. Therefore, we studied time‐associated changes in NPC immunomodulatory properties. We examined whether intracerebrally‐transplanted NPCs are able to inhibit early versus delayed induction of autoimmune brain inflammation and whether allogeneic NPC grafts continuously inhibit host rejection responses. In two experimental designs, intraventricular fetal NPC grafts attenuated clinically and pathologically brain inflammation during early EAE relapse but failed to inhibit the disease relapse if induced at a delayed time point. In correlation, long‐term cultured neural precursors lost their capacity to inhibit immune cell proliferation in vitro. Loss of NPC immune functions was associated with transition into a quiescent undifferentiated state. Also, allogeneic fetal NPC grafts elicited a strong immune reaction of T cell and microglial infiltration and were rejected from the host brain. We conclude that long‐term functional changes in transplanted neural precursor cells lead to loss of their therapeutic immune‐regulatory properties, and render allogeneic grafts vulnerable to immunologic rejection. Thus, the immunomodulatory effects of neural precursor cell transplantation are limited in time. © 2012 Wiley Periodicals, Inc.
Inhibition of PRC2 histone methyltransferase activity increases TRAIL‐mediated apoptosis sensitivity in human colon cancer cells
Authors: Benoit Yannick D. , Laursen Kristian B. , Witherspoon Mavee S. , Lipkin Steven M. , Gudas Lorraine J.
Published: September 2012

Colorectal cancer is ranked among the top leading causes of cancer death in industrialized populations. Polycomb group proteins, including Suz12 and Ezh2, are epigenetic regulatory proteins that act as transcriptional repressors of many differentiation‐associated genes and are overexpressed in a large subset of colorectal cancers. Retinoic acid (RA) acts as a negative regulator of PcG actions in stem cells, but has shown limited therapeutic potential in some solid tumors, including colorectal cancer, in part because of retinoic acid receptor β silencing. Through treatment with RA, Suz12 shRNA knockdown, or Ezh2 pharmacological inhibition with 3‐deazaneplanocin A (DZNep), we increased TRAIL‐mediated apoptosis in human colorectal cancer cell lines. This increased apoptosis in human colon cancer cells after RA or DZNep treatment was associated with a ∼2.5‐fold increase in TNFRSF10B (DR5) transcript levels and a 42% reduction in the H3K27me3 epigenetic mark at the TNFRSF10B promoter after DZNep addition. Taken together, our findings indicate that pharmacological inhibition of Polycomb repressive complex 2 histone methyltransferase activity may constitute a new epigenetic therapeutic strategy to overcome RA non‐responsiveness in a subset of colorectal tumors by increasing TRAIL‐mediated apoptosis sensitivity. J. Cell. Physiol. 228: 764–772, 2013. © 2012 Wiley Periodicals, Inc.
Magnetic resonance elastography of the brain using multishot spiral readouts with self‐navigated motion correction
Authors: Johnson Curtis L. , McGarry Matthew D. J. , Van Houten Elijah E. W. , Weaver John B. , Paulsen Keith D. , Sutton Bradley P. , Georgiadis John G.
Published: September 2012

Magnetic resonance elastography (MRE) has been introduced in clinical practice as a possible surrogate for mechanical palpation, but its application to study the human brain in vivo has been limited by low spatial resolution and the complexity of the inverse problem associated with biomechanical property estimation. Here, we report significant improvements in brain MRE data acquisition by reporting images with high spatial resolution and signal‐to‐noise ratio as quantified by octahedral shear strain metrics. Specifically, we have developed a sequence for brain MRE based on multishot, variable‐density spiral imaging, and three‐dimensional displacement acquisition and implemented a correction scheme for any resulting phase errors. A Rayleigh damped model of brain tissue mechanics was adopted to represent the parenchyma and was integrated via a finite element‐based iterative inversion algorithm. A multiresolution phantom study demonstrates the need for obtaining high‐resolution MRE data when estimating focal mechanical properties. Measurements on three healthy volunteers demonstrate satisfactory resolution of gray and white matter, and mechanical heterogeneities correspond well with white matter histoarchitecture. Together, these advances enable MRE scans that result in high‐fidelity, spatially resolved estimates of in vivo brain tissue mechanical properties, improving upon lower resolution MRE brain studies that only report volume averaged stiffness values. Magn Reson Med 70:404–412, 2013. © 2012 Wiley Periodicals, Inc.
In vivo diffusion tensor MRI of the human heart: Reproducibility of breath‐hold and navigator‐based approaches
Authors: Nielles‐Vallespin Sonia , Mekkaoui Choukri , Gatehouse Peter , Reese Timothy G. , Keegan Jennifer , Ferreira Pedro F. , Collins Steve , Speier Peter , Feiweier Thorsten , de Silva Ranil , Jackowski Marcel P. , Pennell Dudley J. , Sosnovik David E. , Firmin David
Published: September 2012

The aim of this study was to implement a quantitative in vivo cardiac diffusion tensor imaging (DTI) technique that was robust, reproducible, and feasible to perform in patients with cardiovascular disease. A stimulated‐echo single‐shot echo‐planar imaging (EPI) sequence with zonal excitation and parallel imaging was implemented, together with a novel modification of the prospective navigator (NAV) technique combined with a biofeedback mechanism. Ten volunteers were scanned on two different days, each time with both multiple breath‐hold (MBH) and NAV multislice protocols. Fractional anisotropy (FA), mean diffusivity (MD), and helix angle (HA) fiber maps were created. Comparison of initial and repeat scans showed good reproducibility for both MBH and NAV techniques for FA (P > 0.22), MD (P > 0.15), and HA (P > 0.28). Comparison of MBH and NAV FA (FAMBHday1 = 0.60 ± 0.04, FANAVday1 = 0.60 ± 0.03, P = 0.57) and MD (MDMBHday1 = 0.8 ± 0.2 × 10−3 mm2/s, MDNAVday1 = 0.9 ± 0.2 × 10−3 mm2/s, P = 0.07) values showed no significant differences, while HA values (HAMBHday1Endo = 22 ± 10°, HAMBHday1Mid‐Endo = 20 ± 6°, HAMBHday1Mid‐Epi = −1 ± 6°, HAMBHday1Epi = −17 ± 6°, HANAVday1Endo = 7 ± 7°, HANAVday1Mid‐Endo = 13 ± 8°, HANAVday1Mid‐Epi = −2 ± 7°, HANAVday1Epi = −14 ± 6°) were significantly different. The scan duration was 20% longer with the NAV approach. Currently, the MBH approach is the more robust in normal volunteers. While the NAV technique still requires resolution of some bulk motion sensitivity issues, these preliminary experiments show its potential for in vivo clinical cardiac diffusion tensor imaging and for delivering high‐resolution in vivo 3D DTI tractography of the heart. Magn Reson Med 70:454–465, 2013. © 2012 Wiley Periodicals, Inc.
Pacemakers in the upper urinary tract
Authors: Di Benedetto Antonina , Arena Salvatore , Nicotina Piero Antonio , Mucciardi Giuseppe , Galì Alessandro , Magno Carlo
Published: September 2012

Background

Pacemakers in upper urinary tract (UUT) are still under study.

Aim

We reviewed the role of some cells that seem to be involved in the propulsion of urinary bolus from UUT to the bladder.

Materials & Methods

We focuses on evaluating studies on the mechanisms by which the UUT propels urine to the bladder via pacemaker cells.

Results

Electric active pacemaker cells generate pyeloureteric autorhythmicity driving adjacent smooth muscle cells (SMCs); it emphasizes the role of the interstitial cells of Cajal‐like cells (ICC‐LCs) localized in the UUT. Interstitial cells of Cajal (ICCs) are now thought to cooperate in conducting and amplifying pacemaker activity in the UUT. These cells produce electrical slow‐wave potentials and determine the propagation of peristaltic activity. Identification of ICC‐LCs is facilitated by use of c‐kit antibodies. Contraction waves arising from the UUT and the propagation of these waves may require the direct involvement of ICC‐LCs, as c‐kit immunoreactivity appears developmentally at the same time as coordinated unidirectional peristaltic contraction. ICC‐LCs observed in the UUT have morphological features similar to those of c‐kitpositive ICCs in the gastrointestinal tract. In addition to gastrointestinal motility, ICCs may also play a significant role in the propagation, coordination, and modulation of ureteropelvic peristalsis.

Discussion

Alterations in ICC‐LCs are closely associated with a variety of motility disorders and many congenital urological diseases of the UUT such as primary obstructive megaureter, congenital ureteropelvic junction obstruction, and vesicoureteral reflux.

Conclusion

These observations open the way for further investigations of this cell type. Neurourol. Urodynam. 32: 349–353, 2013. © 2012 Wiley Periodicals, Inc.
Clonal evolution of high‐grade serous ovarian carcinoma from primary to recurrent disease
Authors: Castellarin Mauro , Milne Katy , Zeng Thomas , Tse Kane , Mayo Michael , Zhao Yongjun , Webb John R , Watson Peter H , Nelson Brad H , Holt Robert A
Published: September 2012

High‐grade serous carcinoma (HGSC) is the most common and fatal form of ovarian cancer. While most tumours are highly sensitive to cytoreductive surgery and platinum‐ and taxane‐based chemotherapy, the majority of patients experience recurrence of treatment‐resistant tumours. The clonal origin and mutational adaptations associated with recurrent disease are poorly understood. We performed whole exome sequencing on tumour cells harvested from ascites at three time points (primary, first recurrence, and second recurrence) for three HGSC patients receiving standard treatment. Somatic point mutations and small insertions and deletions were identified by comparison to constitutional DNA. The clonal structure and evolution of tumours were inferred from patterns of mutant allele frequencies. TP53 mutations were predominant in all patients at all time points, consistent with the known founder role of this gene. Tumours from all three patients also harboured mutations associated with cell cycle checkpoint function and Golgi vesicle trafficking. There was convergence of germline and somatic variants within the DNA repair, ECM, cell cycle control, and Golgi vesicle pathways. The vast majority of somatic variants found in recurrent tumours were present in primary tumours. Our findings highlight both known and novel pathways that are commonly mutated in HGSC. Moreover, they provide the first evidence at single nucleotide resolution that recurrent HGSC arises from multiple clones present in the primary tumour with negligible accumulation of new mutations during standard treatment.
PLA‐based nanoparticles with tunable hydrophobicity and degradation kinetics
Authors: Yu Yingchun , Ferrari Raffaele , Lattuada Marco , Storti Giuseppe , Morbidelli Massimo , Moscatelli Davide
Published: September 2012

In this work, the preparation of poly(lactic acid) (PLA)‐based degradable nanoparticles (NPs) with tunable hydrophobicity and degradation kinetics via starved emulsion free‐radical polymerization is studied. The synthesis of macromonomers, constituted of a tunable number of lactic acid units functionalized with 2‐hydroxyethyl methacrylate (HEMA), has been performed via bulk ring opening polymerization (ROP) of L, L‐lactide catalyzed with 2‐ethylhexanoic acid tin (II) salt. Macromonomers were characterized through SEC, NMR, and FTIR and are subsequently polymerized through monomer‐starved semi‐batch emulsion polymerization (MSSEP). The effect on the polymerization process of various emulsifiers on the final diameter and particle size distribution has been studied. The resulting PLA‐based NPs are characterized by a narrow size distribution and a small particle size, down to 25 nm. Finally, a degradation study of selected NPs has been carried out to verify their degradability in aqueous media. It has been demonstrated the complete degradability of these PLA‐based NPs which occurs upon the hydrolysis of the PLA pendant chains leaving poly‐HEMA chains, which, being hydrophilic causes the NPs to dissolve in the aqueous suspension. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Acute and Sub‐Acute Oral Toxicity Assessment of the Hydroalcoholic Extract of Withania somnifera Roots in Wistar Rats
Authors: Prabu P. C. , Panchapakesan S. , Raj C. David
Published: September 2012

Withania somnifera is a widely used medicinal plant for several disorders. Toxicity studies on Withania somnifera are not available. Acute and sub‐acute oral toxicities of Withania somnifera root extract in Wistar rats were evaluated in the present study. In the acute toxicity study, WSR extract was administered to five rats at 2000 mg/kg, once orally and were observed for 14 days. No toxic signs/mortality were observed. In the sub‐acute study, WSR extract was administered once daily for 28 days to rats at 500, 1000 and 2000 mg/kg, orally. No toxic signs/mortality were observed. There were no significant changes (P < 0.05) in the body weights, organ weights and haemato‐biochemical parameters in any of the dose levels. No treatment related gross/histopathological lesions were observed. The present investigation demonstrated that the no observed adverse effect level was 2000 mg/kg body weight per day of hydroalcoholic extract of W. somnifera in rats and hence may be considered as non‐toxic. Copyright © 2012 John Wiley & Sons, Ltd.
The effect of histatin 5, adsorbed on PMMA and hydroxyapatite, on Candida albicans colonization
Authors: Vukosavljevic D. , Custodio W. , Del Bel Cury A. A. , Siqueira W. L.
Published: September 2012

The limited number of treatments for oral candidiasis resulted in the emergence of azole‐resistant Candida albicans strains, thus enforcing the need for novel antifungal treatments. Although histatin 5 (H5) demonstrates antifungal activity, its inhibitory effect when adhered to hydroxyapatite and Polymetylmethacrylate (PMMA) surfaces, resembling conditions of the in vivo pellicle, remains unexplored. The objective of this in vitro study was to determine whether surface‐adhered H5 inhibits the colonization of C. albicans on hydroxyapatite and/or PMMA. The C. albicans assay involved developing a mono‐protein pellicle (either H5 or albumin) on hydroxyapatite and PMMA discs, introducing C. albicans and counting the number of adhered cells, throughout time, using scanning electron microscopy. A negative binomial statistical model and the Tukey–Kramer test were used for statistical analysis, with p < 0.01 indicating significance. H5‐coated PMMA had significantly reduced number of cells compared to albumin‐coated PMMA at 30, 90 and 1440 min (p < 0.0001), with the number of cells decreasing significantly in 90 and 1440 min (p < 0.0001). Similarly, H5‐coated hydroxyapatite had significantly fewer cells compared to the albumin‐coated surface at 90 and 1440 min (p < 0.0001), with the number of cells decreasing significantly at 30, 90 and 1440 min (p < 0.0001). In conclusion, C. albicans colonization was most inhibited by PMMA and hydroxyapatite‐adhered H5 after 1440 min, illustrating the time‐dependent effect of H5. In addition, yeast cells colonized albumin‐coated PMMA, while dense hyphal networks formed on albumin‐coated hydroxyapatite, suggesting that C. albicans morphology is influenced by the surface available for albumin adhesion. Copyright © 2012 John Wiley & Sons, Ltd.
Erratum to: Identification of functional differences between recombinant human α and β cardiac myosin motors
Authors: Deacon John C. , Bloemink Marieke J. , Rezavandi Heresh , Geeves Michael A. , Leinwand Leslie A.
Published: September 2012

The myosin isoform composition of the heart is dynamic in health and disease and has been shown to affect contractile velocity and force generation. While different mammalian species express different proportions of α and β myosin heavy chain, healthy human heart ventricles express these isoforms in a ratio of about 1:9 (α:β) while failing human ventricles express no detectable α-myosin. We report here fast-kinetic analysis of recombinant human α and β myosin heavy chain motor domains. This represents the first such analysis of any human muscle myosin motor and the first of α-myosin from any species. Our findings reveal substantial isoform differences in individual kinetic parameters, overall contractile character, and predicted cycle times. For these parameters, α-subfragment 1 (S1) is far more similar to adult fast skeletal muscle myosin isoforms than to the slow β isoform despite 91% sequence identity between the motor domains of α- and β-myosin. Among the features that differentiate α- from β-S1: the ATP hydrolysis step of α-S1 is ~ten-fold faster than β-S1, α-S1 exhibits ~five-fold weaker actin affinity than β-S1, and actin·α-S1 exhibits rapid ADP release, which is >ten-fold faster than ADP release for β-S1. Overall, the cycle times are ten-fold faster for α-S1 but the portion of time each myosin spends tightly bound to actin (the duty ratio) is similar. Sequence analysis points to regions that might underlie the basis for this finding.
Development of novel microsatellite markers for effective applications in Anthurium cultivar identification
Authors: Wang Jau-Yueh , Chuang Keng-Chang
Published: September 2012

Anthurium andraeanumis one of the most economically important floral crops and potted flowers marketed worldwide. Microsatellite markers are currently the preferred molecular marker owing to the many desirable attributes, including hypervariability, codominance, and amenability to high-throughput genotyping; however, there are few polymorphic molecular markers available for Anthurium. The object of this study was to develop and characterize novel microsatellite markers using the Araceae sequences in GenBank of the National Center for Biotechnology Information (NCBI) to contribute to molecular identification for cultivar protection. Using 1,579 Araceae expressed sequence tags (ESTs) and the related nucleotide sequences, 100 candidates contained simple sequence repeat (SSR) motifs that were suitable for primer design. Furthermore, 100 pairs of SSR primers were screened against a set of 28 diverse genotypes representing 24 cultivars that included four registration cultivars which were bred from the Taiwan Agricultural Research Institute (TARI) and 20 commercial cultivars, appended with three hybrid progeny and a mutant line. From the selected six polymorphic SSR loci, 52 alleles were amplified and 27 distinct genotypes were found, except for ‘Tropical’ and its mutant, with a mean number of eight alleles per locus. The polymorphism information content (PIC) ranged from 0.86 to 0.93. Based on these results, we proposed a key identification set using four microsatellite markers that is sufficient to discriminate among 24 cultivars. Because the Anthurium microsatellite markers developed in this study are primarily from expressed sequence tags or related genomic sequences, they can be used for cultivar identification and, accordingly, contribute to genetic evaluations in breeding programs.
Variables Influencing Pregnancy Termination Following Prenatal Diagnosis of Fetal Chromosome Abnormalities
Authors: Hawkins Anne , Stenzel Ana , Taylor Joanne , Chock Valerie Y. , Hudgins Louanne
Published: September 2012

The objective of this study was to identify variables that may influence the decision to terminate or continue a pregnancy affected by a chromosome abnormality. We performed a retrospective cohort analysis of 286 pregnancies diagnosed with a chromosome abnormality following genetic counseling and prenatal diagnosis. Data obtained included procedure type, chromosome results, ethnicity, maternal age, use of fertility treatments, and uptake of genetic counseling after results, among other factors. Wilcoxon rank sum test, Fisher's exact test, and univariate and multivariate logistic regression models were used for data analysis. The overall termination rate in this study was 82.9 %. A lower likelihood to terminate was found in pregnancies with a diagnosis of a sex chromosome abnormality (OR 0.05, p < .0001), Filipina race (OR 0.10, p = .03), and uptake of second genetic counseling session (OR 0.05, p < .0001). Prior history of termination was associated with increased likelihood to terminate (OR 8.6, p = .02). Factors revealing no statistically significant association with termination included maternal age, gestational age, clinic site, fetal gender, ultrasound anomalies, reason for referral and who informed the patient. Our data affirm the complexity of the decision making process and reinforce that providers should refrain from making assumptions regarding a patient's likelihood to terminate based on factors such as maternal age, gestational age, type of procedure, or ultrasound.
Surface and Biological Activity of Some Prepared Iminium Surfactants Based on Schiff Bases
Authors: Aiad Ismail , EL‐Sukkary Mohamed M. , El‐Deeb Ali , El‐Awady Moshira Y. , Shaban Samy M.
Published: September 2012

A series of novel iminium surfactants were prepared through quaternization of different prepared fatty Schiff bases with benzyl chloride. The chemical structures were confirmed using FTIR, 1H‐NMR and mass spectroscopy. The surface properties and biological activity of these surfactants were investigated. The surface parameters including critical micelle concentration (CMC), maximum surface excess (Γmax) and minimum surface area (Amin), Efficiency (PC20) and Effectiveness (πCMC) as well as the free energy of micellization () and adsorption () were calculated. It was found that the prepared compounds have good surface and biological activity.
Experimental Study of CMC Evaluation in Single and Mixed Surfactant Systems, Using the UV–Vis Spectroscopic Method
Authors: Tanhaei Bahareh , Saghatoleslami Nasser , Chenar Mahdi Pourafshari , Ayati Ali , Hesampour Mehrdad , Mänttäri Mika
Published: September 2012

In this study, the critical micellar concentration (CMC) of anionic, cationic and nonionic surfactants was determined using the UV–Vis spectroscopic method. Sodium lauryl sulfate (SDS) as anionic, hexadecyl‐trimethyl‐ammonium bromide as cationic, tert‐octylphenol ethoxylates TOPEON (with N = 9.5, 7.5 and 35) and lauryl alcohol ethoxylate (23EO) as nonionic surfactants have been used. Concentration of surfactants varies both from below and above the CMC value in the pyrene solution. In addition, the amount of the CMC was determined using the values from the data obtained from the graph of absorbance versus concentration of surfactants. A comparative study was conducted between the results of the present study and the literature which shows a good agreement, in particular for TOPEO9.5 and LAEO23. Furthermore, the CMC value of SDS (as an ionic surfactant) in the presence of nonionic surfactants was also examined. The result reveals that with addition of small amount of nonionic surfactant to the anionic SDS surfactant, a decline in the CMC value of the anionic–nonionic system relative to the CMC of pure anionic surfactant was observed. In addition and for the first time, the effect of UV irradiation on the size of the micelle formations was studied. It was found that UV irradiation causes the formation of smaller micelles which is of prime concern in membrane technology.
Reducing Oil Losses in Alkali Refining
Authors: Chumsantea Salisa , Aryusuk Kornkanok , Lilitchan Supathra , Jeyashoke Narumon , Krisnangkura Kanit
Published: September 2012

Neutralization is an important step in the chemical refining of edible oils. Free fatty acids (FFA) are generally removed in neutralization as sodium soaps but neutral oil is also entrapped in the emulsion and removed with the soap during centrifugation. Thus, alkali neutralization causes a major loss of neutral oil in the chemical refining of edible oils. The effects of demulsifiers (NaCl, KCl, Na2SO4 and tannic acid) on reducing alkali refining losses of refined palm, soybean, and sunflower oils (used as model oils) incorporated with FFA from rice bran oil were investigated. Adding small amounts of demulsifiers to the alkali neutralization step significantly reduced neutral oil loss of these model oils. All demulsifiers except for tannic acid had similar effects on refining losses in all oil model systems. The optimum demulsifier content was 1.0 % (w/w of oil).
Regiospecific Analysis of Shark Liver Triacylglycerols
Authors: Jayasinghe Chamila , Gotoh Naohiro , Wada Shun
Published: September 2012

The liver oils of six shallow‐water shark species, silky (Carcharhinus falciformis), thresher (Alopias superciliosus), oceanic whitetip (Carcharhinus longimanus), blue (Prionace glauca), hammerhead (Sphyrna lewini) and salmon (Lamna ditropis) were analyzed with particular attention to the regioisomeric composition of triacylglycerols (TAG). The TAG compositions were analyzed by using an HPLC‐evaporative light scattering detector and each molecular species identified by HPLC‐atmospheric pressure chemical ionization/mass spectrometry. Major lipid components of all sharks’ oils were TAG (~80 %) made up of omega‐3 polyunsaturated fatty acids at 26–40 % and 20–25 % docosahexaenoic acid (DHA). Forty different molecular species were detected in the TAG fractions. TAG consisting of one palmitic acid, one DHA and one oleic acid (12.5–19.9 %) and TAG consisting of two palmitic acids and one DHA (8.4–15.4 %) were the predominant form while 30–50 % TAG molecular species were bound to one or more DHA. Distribution of fatty acids in the primary (sn‐1 and sn‐3) and secondary (sn‐2) position of the glycerol backbones was examined by regiospecific analysis by using pancreatic lipase and it was found that DHA was preferentially positioned at sn‐2. These findings greatly extend the utilization of shark liver oils in food productions and may have a significant impact on the future development of the fish oil industry.
Identification of Minor Acylglycerols Less Polar than Triricinolein in Castor Oil by Mass Spectrometry
Authors: Lin Jiann‐Tsyh , Chen Grace Q.
Published: September 2012

Acylglycerols in castor oil less polar than triricinolein were identified by electrospray ionization–mass spectrometry using the lithium adducts of the acylglycerols in the HPLC fractions of castor oil. Thirty four new molecular species of acylglycerols containing hydroxy fatty acids in castor oil were identified by MS. The chain lengths of fatty acid substituents were C16, C18, C20, C22 and C23. The numbers of double bonds of the fatty acids were from zero to three. The numbers of hydroxyl groups on the fatty acid chains were from zero to three as previously reported. The structure of fatty acid, OH18:2, was proposed as 12‐hydroxy‐9,13‐octadecadienoic acid. An unusual odd‐numbered long‐chain fatty acid, 23:0 (tricosanoic acid), was identified. Some new estolides and tetraacylglycerols, were identified as (12‐ricinoleoylricinoleoyl)‐ricinoleoyl‐linoleoyl‐glycerol (RRRL), (12‐ricinoleoylricinoleoyl)‐ricinoleoyl‐oleoyl‐glycerol (RRRO), (12‐ricinoleoylricinoleoyl)‐ricinoleoyl‐palmitoyl‐glycerol (RRRP), (12‐ricinoleoylricinoleoyl)‐ricinoleoyl‐stearoyl‐glycerol (RRRS) and (12‐ricinoleoylricinoleoyl)‐ricinoleoyl‐linolenoyl‐glycerol (RRRLn). The normal fatty acid (non‐hydroxylated) of these tetraacylglycerols were directly attached to the glycerol backbone. The biosynthetic pathway of castor oil is proposed.
Ratios of Regioisomers of Minor Acylglycerols Less Polar than Triricinolein in Castor Oil Estimated by Mass Spectrometry
Authors: Lin Jiann‐Tsyh , Chen Grace Q.
Published: September 2012

We have recently reported the identification of forty new minor molecular species of acylglycerols containing hydroxy fatty acids less polar than triricinolein by electrospray ionization mass spectrometry of the lithium adducts. The ratios of regioisomers of triacylglycerols (ABC and AAB types) and tetraacylglycerols (AAAB type) identified were estimated by the relative abundances of the fragment ions from the neutral losses of fatty acids as α,β‐unsaturated fatty acids at the sn‐2 position. The order of the contents of regioisomers of triacylglycerols with the fatty acids at the sn‐2 position are: nonhydroxy fatty acids > monohydroxy fatty acids > dihydroxy fatty acids > trihydroxy fatty acids. For tetraacylglycerols (AAAB type) such as ricinoleoylricinoleoyl–ricinoleoyl–oleoyl–glycerol (RRRO), ricinoleoylricinoleoyl chain was predominately at the sn‐2 position, while ricinoleate was not detected at the sn‐2 position.
The Toxic Aldehyde, 4‐Hydroxy‐2‐trans‐nonenal (HNE) Formation in Natural and Imitation Mozzarella Cheeses: Heat Treatment Effects
Authors: Han In Hwa , Csallany A. Saari
Published: September 2012

The formation of 4‐hydroxy‐2‐trans‐nonenal (HNE), a toxic aldehyde formation, was investigated in heat treated imitation Mozzarella cheeses which are made with vegetable oils and in natural Mozzarella cheeses which contain dairy fats. The cheeses were heat treated at 204 °C for 30 and 60 min, and at 232 °C for 15 and 30 min. The HNE formations were much higher in imitation cheeses than in natural cheeses due to both heat treatments. Average HNE concentrations in imitation cheeses, after 30 min of heat treatment at 204 °C, were 110.3 ng HNE/g cheese and it increased to 877.1 ng HNE/g cheese when the temperature was raised to 232 °C. In natural cheeses, the average HNE concentration was much lower only 13.4 ng HNE/g cheese after 204 °C heat treatment for 30 min and it increased only to 182.8 ng HNE/g cheese using 232 °C. Since imitation cheeses are made with vegetable oils which contain much higher levels of linoleic acid, a precursor for HNE, than dairy fat, it is not surprising that heat‐induced lipid peroxidation results in increased HNE formation in imitations cheeses compared to dairy fat containing cheeses, which are low in linoleic acid.
Bubble and Crystal Formation in Lipid Systems During High‐Intensity Insonation
Authors: Martini Silvana , Tejeda‐Pichardo R. , Ye Y. , Padilla S. G. , Shen F. K. , Doyle T.
Published: September 2012

The objective of the present research was to monitor bubble and crystal formation in lipids during high‐intensity insonation. High‐intensity ultrasound was generated with a 20‐kHz probe. Bubble and crystal formations were recorded using a low‐intensity ultrasound spectrometer operating at 1 MHz central frequency. Bubble formation was monitored in soybean oil (SBO) during insonation for different time periods (5, 10 and 60 s) and at different temperatures (22, 24, 26, 28, and 30 °C). Ultrasound attenuation due to the presence of bubbles was observed in all conditions tested. Attenuation increased with temperature and at intermediate frequencies (1 MHz). In addition, the presence of bubbles was detected after insonation was stopped, particularly for SBO sonicated for 60 s at 30 °C. Low‐intensity ultrasound spectroscopy was used to monitor the crystallization behavior of interesterified SBO. The acoustic velocity increased during crystallization, but significantly decreased during insonation.
cis‐, trans‐ and Saturated Fatty Acids in Selected Hydrogenated and Refined Vegetable Oils in the Indian Market
Authors: Amrutha Kala A. L.
Published: September 2012

The fatty acid composition of 27 samples of commercial hydrogenated vegetable oils and 23 samples of refined oils such as sunflower oil, rice bran oil, soybean oil and RBD palmolein marketed in India were analyzed. Total cis, trans unsaturated fatty acids (TFA) and saturated fatty acids (SFA) were determined. Out of the 27 hydrogenated fats, 11 % had TFA about 1 % where as 11 % had more than 5 % TFA with an average value of about 13.1 %. The 18:1 trans isomers, elaidic acid was the major trans contributor found to have an average value of about 10.8 % among the fats. The unsaturated fatty acids like cis‐oleic acid, linoleic acid and α‐linolenic acid were in the range of 21.8–40.2, 1.9–12.2, 0.0–0.7 % respectively. Out of the samples, eight fats had fatty acid profiles of low TFA (less than 10 %) and high polyunsaturated fatty acids (PUFA) such as linoleic and α‐linolenic acid. They had a maximum TFA content of 7.3 % and PUFA of 11.7 %. Among the samples of refined oils, rice bran oil (5.8 %) and sunflower oil (4.4 %) had the maximum TFA content. RBD palmolein and rice bran oils had maximum saturated fatty acids content of 45.1 and 24.4 % respectively. RBD palmolein had a high monounsaturated fatty acids (MUFA) content of about 43.4 %, sunflower oil had a high linoleic acid content of about 56.1 % and soybean oil had a high α‐linolenic acid content of about 5.3 %.
Determining Frying Oil Degradation by Near Infrared Spectroscopy Using Chemometric Techniques
Authors: Öğütcü Mustafa , Aydeniz Buket , Büyükcan Mehmet Burak , Yılmaz Emin
Published: September 2012

A rapid method for the determination of some important physicochemical properties in frying oils has been developed. Partial least square regression (PLS) calibration models were applied to the physicochemical parameters and near infrared spectroscopy (NIR) spectral data. PLS regression was used to find the NIR region and the data pre‐processing method that give the best prediction of the chemical parameters. Calibration and validation were appropriated by leave one out cross validation and test set validation techniques for predicting free fatty acids (FFA), total polar materials (cTPM; measured by chromatographic method and iTPM measured by an instrumental method), viscosity and smoke point of the frying oil samples. For PLS models using the cross validation techniques, the best correlations (r) between NIR predicted data and the standard method data for iTPM in oils were 93.79 and root mean square error of prediction (RMSEP) values were 5.53. For PLS models using the test set validation techniques, the best correlations (r) between NIR predicted data and standard method data for FFA, cTPM, viscosity and smoke point in oils were 92.58, 94.61, 81.95 and 84.07 and RMSEP values were 0.121, 3.96, 22.30 and 8.74, respectively. In conclusion, NIR technique with chemometric analysis was found very effective in predicting frying oil quality changes.
Aldehydes from Oxidized Lipids Can React with 2,2‐Diphenyl‐1‐Picrylhydrazyl (DPPH) Free Radicals in Isooctane Systems
Authors: Jeong Min Kyu , Yeo JuDong , Jang Eun Yeong , Kim Mi‐Ja , Lee JaeHwan
Published: September 2012

Oxidized lipids can decrease the absorbance of 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) in isooctane. However, the compounds responsible for the decrease in DPPH absorbance are still not known. Major factors and possible compounds decreasing the DPPH absorbance during lipid oxidation were identified using linoleic and oleic acid model systems. Changes in the hydroperoxides and conjugated dienoic acid value in thermally oxidized linoleic acid were not highly correlated with those of DPPH absorbance under air‐tight and nitrogen flushing conditions. Radical scavenging compounds from oxidized oleic acid were tentatively identified as mixtures of aldehydes, alcohols, and acids. Aldehydes from oxidized fatty acids including pentanal, t‐2‐heptenal and t‐2‐nonenal can react with DPPH, whereas most alcohols and hydrocarbons did not show DPPH scavenging activity. Aldehydes rather than conjugated dienes and hydroperoxides may be the radical scavenging compounds from oxidized lipids. The results of this study will help to understand better the changes in oxidation products during lipid oxidation.
Experiments, Modeling and Control of a Dryer–Cooler of Expanded Raw Soybean Flakes in a Hexane Extraction Plant
Authors: da Silva Hofmann Augusto Marcos , Benincá Cristina , Kotovicz Valesca , Zanoelo Everton Fernando
Published: September 2012

Drying and cooling are preparatory operations typically applied in the soybean processing industry to reduce the moisture content and temperature of the flakes fed to the extractor. Although these parameters are important for a safe and optimal process of extraction, limited or even inexistent schemes for their control are available. To deal with this problem, the current investigation suggests the use of a PID controller to manipulate the speed of the conveyor belt in order to keep the temperature of the flakes in the discharge of the dryer–cooler close to 61 °C without exceeding the acceptable outlet moisture content range from 9.9 to 12.3 % dry basis (d.b.). Closed‐loop responses for the controlled variables when considering simultaneous arbitrary disturbances on operating conditions confirmed the reliability of the current control strategy. A dynamic model represented by a system of two partial differential equations obtained by energy and mass balances for the solute in the bed was used as a virtual conveyor‐belt dryer‐cooler. Its consistency was checked by a comparison between experimental and calculated results for moisture content and temperature at the exit of a size‐scale dryer–cooler of soybean flakes at typical industrial operating conditions. The ISE technique and the simplex method of optimization were used to tune the set of PID parameters in which process control was stable.
Bioimprinted Immobilization of Candida antarctica Lipase A for Concentration of Omega‐3 Polyunsaturated Fatty Acids
Authors: Kahveci Derya , Xu Xuebing
Published: September 2012

Bioimprinting and immobilization of Candida antarctica lipase A (CALA) was optimized by response surface methodology to improve its selectivity for concentration of omega‐3 polyunsaturated fatty acids (PUFA) by lipase‐catalyzed ethanolysis of salmon oil obtained from salmon by‐products. Enzyme‐to‐support ratio, oleic acid concentration, and immobilization time were the factors investigated. Total omega‐3 PUFA lost to the ethyl esters (EE) fraction was monitored in relation to the varying levels of the factors. Results showed that the second‐order polynomial model generated adequately fitted the experimental data. The most critical factor was the enzyme‐to‐support ratio, which led to decreased recovery of omega‐3 PUFA in the glycerides fraction with increasing levels of enzyme amount. Optimum conditions were selected as follows: enzyme‐to‐support ratio, 0.2 (w/w); oleic acid concentration, 50 mM; immobilization time, 85 min. The total omega‐3 PUFA lost to the EE fraction through ethanolysis of salmon oil decreased from 3.76 to 1.47 (mol%) under the optimum conditions.
Detection of Olive Oil Adulteration Using FT‐IR Spectroscopy and PLS with Variable Importance of Projection (VIP) Scores
Authors: Oussama Abdelkhalek , Elabadi Fatiha , Platikanov Stefan , Kzaiber Fouzia , Tauler Roma
Published: September 2012

Determination of adulteration and authenticity of extra virgin olive oil (EVOO) was investigated by means of infrared spectroscopy and chemometric methods. The study was focused on the detection and quantification of extra virgin olive oil adulteration by soybean (SB) and sunflower (SF) oils using FT‐IR spectroscopy based on the use of PLS modeling and variable importance of projection (VIP) scores. A PLS model, using orthogonal signal correction and mean centering data pretreatments, and VIP scores variable preselection, was able to predict the concentration of sunflower and soybean oil adulterants in the 1–24 % weight ratio range with relative prediction errors lower than 3 % (w/w), for external validation samples. Moreover, the PLS‐DA (discriminant analysis) model using the same preselected wavelengths was able to explain 99.9 % of variance and to predict with 100 % accuracy both classes of adulteration (EVOO–SB and EVOO–SF) in the external validation.
Selective Microbial Degradation of Saturated Methyl Branched‐Chain Fatty Acid Isomers
Authors: Ngo Helen L. , Ashby Richard D. , Nuñez Alberto
Published: September 2012

Three strains of Pseudomonas (P.) bacteria were screened for their capabilities of degrading chemically synthesized saturated branched‐chain fatty acids (sbc–FA). Mixtures of sbc–FA with the methyl‐branch located at various locales along the fatty acid were used as a carbon feedstock in shake‐flask culture. Utilization (and hence degradability) of the sbc–FA was monitored based on positive bacterial growth, fatty acid recovery rates and chromatographic (gas chromatography (GC) and GC‐mass spectroscopy (MS)) analysis of the recovered carbon source. P. putida KT2442 and P. oleovorans NRRL B‐14683 were both able to grow on sbc–FA utilizing 35 wt% and 27 wt% of the carbon source, respectively after 144 h. In contrast, P. resinovorans NRRL B‐2649 exhibited the most efficient use of the carbon source by utilizing 89 % of the starting material after 96 h resulting in a cell dry weight (CDW) of 3.1 g/L. GC and GC–MS analysis of the recovered carbon source revealed that the bacterial strains selectively utilized the isostearic acid in the sbc–FA mixture, and a new group of C10, C12, C14 and C16‐linear and/or branched‐chain fatty acids (approximately 4–29 wt%) were formed during degradation.
Rheology of Cream‐like Emulsions Prepared with Soybean Milk and Low Trans Vegetable Fat
Authors: Márquez Andrés L. , Wagner Jorge R.
Published: September 2012

The objective of this work was to study the effect of fat globule size and fat content on the rheological behavior of oil‐in‐water emulsions prepared with soybean milk, sunflower oil and low trans vegetable fat (LTF). Emulsions were prepared with 40 % w/w lipid phase (containing different proportions of LTF) and three different homogenization methods were used in order to obtain different globule sizes. Emulsions were subjected to controlled magnetic shaking until an increase in thickness. Partial coalescence was observed in all systems containing solid fat, which gave a rheopectic behavior and an increase in the viscoelastic parameters of the emulsions. Smaller particle sizes required higher shaking times to produce an increase in thickness, even though this did not lead to different final values of the viscoelastic parameters. The highest partial coalescence degree was observed at 50 % LTF in lipid phase, but the highest final viscoelastic parameters after shaking were observed at 100 % LTF in the lipid phase. The rheological behavior of these emulsions indicates that they could be a potential vegetable substitute for traditional dairy creams.
Purification and Biochemical Characterization of Lipase from Ficus carica Latex of Tunisian East Coast Zidi Variety
Authors: Lazreg‐Aref Houda , Mosbah Habib , Fekih Abdelwaheb , Mars Massoud , Said Khaled
Published: September 2012

Lipase from Ficus carica L. (Moraceae) latex of the Zidi variety was purified 80.5‐fold with 68.5 % recovery using silica gel chromatography. The molecular weight of the enzyme was 29 kDa as determined by SDS‐PAGE. High lipolytic activity was found in the crude extract during the fruit ripening process. The activity of purified lipase (ZL) seemed to depend strongly on chain length and showed a preference to long chain triacylglycerols. Indeed, ZL specific activity was 370.3 UI/mg using olive oil as a substrate at 45 °C and pH 5.5. In contrast, activity towards short chain triacylglycerols (tributyrin) was 12‐fold lower (32 UI/mg). The enzyme was quite stable in the pH range 4–8, and thermally stable at 60 °C displaying t1/2 about 90 min using olive oil as a substrate. The values of Km app and Vm were found to be 14.3 mM and 294.1 μmol/min/mg, respectively. ZL activity was strongly reduced by Fe2+, Mg2+ and Zn2+, while significantly increased by Ca2+ and Cu2+. The enzyme was stimulated by sodium dodecyl sulfate, and Tween‐80, while Triton X‐100 and EDTA had a slight inhibitory effect. No Effect was observed in addition of PMSF and iodoacetic acid.
Characterization of Polyglycerol Polyricinoleate Formulations Using NMR Spectroscopy, Mass Spectrometry and Dynamic Light Scattering
Authors: Orfanakis Andreas , Hatzakis Emmanuel , Kanaki Katerina , Pergantis Spiros A. , Rizos Apostolos , Dais Photis
Published: September 2012

Three different analytical techniques, namely NMR spectroscopy, mass spectrometry and dynamic light scattering, were used to unravel the structure and morphology of polyglycerol polyricinoleate (PGPR). This material is used as an emulsifier in the preparation of chocolate and other confectionary products. The use of 1D and 2D NMR techniques led to the distinction of two separate entities in commercial ricinoleic acid (RA) and PGPR samples, namely the monomeric and oligomeric RA (estolides). 1H and 13C spectra of PGPR confirmed the presence of polyglycerol moieties of various lengths being esterified by RA and estolides and to a lesser extent by oleic and linoleic acids. 13C‐NMR DOSY experiments demonstrated the occurrence of several species in PGPR. Electrospray Ionization and tandem Mass Spectrometry succeeded in identifying the presence of over 30 glycerol/polyglycerol species containing n glycerol moieties with n = 1–6 esterified by monomeric and oligomeric RA molecules. Dynamic light scattering contributed to the characterization of PGPR morphology. The PGPR mixture contains relatively small‐sized entities (monomers, dimmers, trimmers) and larger aggregates resulted from chain association. The percentage of larger aggregates is minimal compared to small‐sized species.