bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of Regional Flavor Differences in U.S. Cheddar Cheeses Aged for 6 Mo or Longer
Authors: Drake M.A. , Yates M.D. , Gerard P.D.
Published: May 2008

ABSTRACT: Cheddar cheese is a widely popular food in the United States. This product is produced in facilities across the United States and often marketed based on region of manufacture, implying that regional differences in flavor character of the cheese exist. This study was conducted to determine if regional differences in flavor exist in the aged U.S. Cheddar cheeses. Three times per year for 2 y, triplicate 18‐kg blocks of Cheddar cheese (< 60 d old) were obtained from 19 manufacturing facilities located in 4 major cheese‐ producing regions/states: California, Northwest, Midwest, and Northeast. A trained sensory panel documented the flavor characteristics of cheeses after 6‐, 9‐, 12‐, 18‐, and 24‐mo ripening at 7 °C. Regional differences were observed for specific flavors for cheeses manufactured in the Northwest, Midwest, and Northeast across ripening (P< 0.05), but the specific flavors responsible for these effects were not consistent across ripening. Similarly, cheese make procedure effects were also observed for specific flavors across ripening (P< 0.05), but these differences were also not consistent across ripening. The impact of region and cheese make procedure on flavor of the aged Cheddar cheeses was small in comparison to consistently documented, facility‐specific flavor differences (P< 0.0001). Flavor profiles of aged Cheddar cheeses were most strongly influenced by practices specific to manufacturing facility rather than region of manufacture.
Attenuated Total Reflectance–Fourier Transform Infrared Spectroscopy Coupled with Multivariate Analysis for Measurement of Acesulfame‐K in Diet Foods
Authors: Shim J.Y. , Cho I.K. , Khurana H.K. , Li Q.X. , Jun S.
Published: May 2008

ABSTRACT:  Fourier transform infrared (FTIR) spectroscopy was investigated as a method for analysis of acesulfame‐K content after a simple extraction procedure for certain commercial diet food samples. Partial least squares (PLS) models were developed for prediction of acesulfame‐K using select spectral ranges on the basis of relevant IR absorption bands associated with acesulfame‐K. The acesulfame‐K content of test food samples was predicted accurately in the fingerprint region between 1100 and 1300 cm−1 with a maximum prediction error of 9.82% when compared with conventional HPLC method. The PLS was found to be a consistently better predictor when both PLS and principal component regression (PCR) analyses were used for quantification of acesulfame‐K. The developed procedure was further validated by comparing with HPLC results as well as recovery studies. As a quick tool, the method developed is expected to be used for routine estimation of acesulfame‐K in commercial products.
Characterization of Headspace Aroma Compounds of Freshly Brewed Arabica Coffees and Studies on a Characteristic Aroma Compound of Ethiopian Coffee
Authors: Akiyama M. , Murakami K. , Hirano Y. , Ikeda M. , Iwatsuki K. , Wada A. , Tokuno K. , Onishi M. , Iwabuchi H.
Published: May 2008

ABSTRACT:  A sampling method to isolate headspace volatiles of freshly brewed drip coffee using a solid‐phase microextraction fiber (fiber type: divinylbenzene/carboxen/polydimethylsiloxane) in a short time (2 min) immediately after extraction has been developed. Volatile compounds and potent odorants obtained from each headspace aroma of various arabica coffee extracts (3 production countries: Ethiopia, Tanzania, and Guatemala; 3 roasting degrees for each country: L26, L23, and L18) using the sampling method were examined by gas chromatography/mass spectrometry (GC/MS) and GC/olfactometry (GC/O, CharmAnalysis™). The results of principal component analysis (PCA) using the data of GC/O analysis showed that the aroma profile of Ethiopian coffee was discriminately different from those of Tanzanian coffee and Guatemalan coffee. In addition, it was suggested from the factor loading of the PCA that 4‐(4′‐hydroxyphenyl)‐2‐butanone (raspberry ketone; sweet‐fruity odor) characterized the aroma profile of freshly brewed Ethiopian coffee. Therefore, the 4‐(4′‐hydroxyphenyl)‐2‐butanone was quantified in the 9 kinds of coffee extracts. Ethiopian coffee extract of the lightly roasted degree (roasting degree: L26) contained the highest amount of this component, while it was only a little over the reported threshold. In the sensory test, the headspace aromas of Tanzanian and Guatemalan coffees in which 4‐(4′‐hydroxyphenyl)‐2‐butanone was added were, respectively, discriminated from not added samples, and “sweet” odor was selected as an odor description that assessors found similarity between the added Tanzanian or Guatemalan coffee aroma and the Ethiopian coffee aroma. It was suggested that 4‐(4′‐hydroxyphenyl)‐2‐butanone made some detectable change on total aroma profile even though the added amount was only near threshold level.
Qualification and Quantification of Fish Protein in Prepared Surimi Crabstick
Authors: Reed Z.H. , Park J.W.
Published: May 2008

ABSTRACT:  Species identification and protein quantification in surimi crabstick were achieved using sodium dodecyl‐sulfate polyacrylamide gel electrophoresis (SDS‐PAGE). When the Lowry and Kjeldahl protein determination methods were compared, the former showed more consistent results. Densitometric scanning of the gels was used for quantification of total fish protein as well as total egg white protein. The lower molecular weight proteins, 30 kDa and lower, proved to be the most useful in fish species identification as well as egg white protein addition. Using a combination of the myosin heavy chain band and the species‐specific myosin light chain (Alaska pollock: 22.5 kDa; Pacific whiting: 24.4 kDa) proved the most accurate in calculating fish protein content of the crabstick sample, while for those samples that contained egg white, quantification was accomplished from the densitometric analysis of the overlapping bands of actin (45 kDa) from fish and ovalbumin from egg white. Lysozyme (14.3 kDa) proved to be a unique protein band in determining the presence of egg white when the content of dried egg white was equal to or exceeded 0.5% of the total weight of the final crabstick.
Processing and Storage Effects on Monomeric Anthocyanins, Percent Polymeric Color, and Antioxidant Capacity of Processed Blueberry Products
Authors: Brownmiller C. , Howard L.R. , Prior R.L.
Published: May 2008

ABSTRACT:  This study evaluated the effects of processing and 6 mo of storage on total monomeric anthocyanins, percent polymeric color, and antioxidant capacity of blueberries that were canned in syrup (CS), canned in water (CW), pureed, and juiced (clarified and nonclarified). Total monomeric anthocyanins, percent polymeric color, and oxygen radical absorbing capacity (ORAC) assay using fluorescein (ORACFL) were determined postprocessing after 1 d, and 1, 3, and 6 mo of storage. Thermal processing resulted in marked losses in total anthocyanins (28% to 59%) and ORACFL values (43% to 71%) in all products, with the greatest losses occurring in clarified juices and the least in nonclarified juices. Storage at 25 °C for 6 mo resulted in dramatic losses in total anthocyanins, ranging from 62% in berries CW to 85% in clarified juices. This coincided with marked increases in percent polymeric color values of these products over the 6‐mo storage. The ORACFL values showed little change during storage, indicating that the formation of polymers compensated for the loss of antioxidant capacity due to anthocyanin degradation. Methods are needed to retain anthocyanins in thermally processed blueberries.
Analysis of Volatile Compounds in Beef Fat by Dynamic‐Headspace Solid‐Phase Microextraction Combined with Gas Chromatography–Mass Spectrometry
Authors: Watanabe A. , Ueda Y. , Higuchi M. , Shiba N.
Published: May 2008

ABSTRACT:  A solid‐phase microextraction (SPME) technique has been applied to the determination of the volatile compounds, including diterpenoids and lactones, in cooked beef fat. The ability of static‐headspace SPME to extract lactones was disappointing, regardless of the type of SPME fiber or the temperature used. Dynamic‐headspace SPME extraction with 50‐/30‐μm divinylbenzene‐Carboxen on a polydimethylsiloxane fiber at 100 °C, by contrast, enabled the analysis of volatiles, including delta‐lactones, gamma‐lactones, and diterpenoids, with 50‐/30‐μm divinylbenzene‐Carboxen on a polydimethylsiloxane fiber at 100 °C. Fifty‐three compounds were identified from only 0.20 g of rendered beef fat, and 76% of these showed reliable peak size repeatability: the coefficient of variation was less than 10% on the total ion chromatograms obtained from gas chromatography–mass spectrometry (GC–MS) analysis. Some lactones showed higher CV values (>10%), but single‐ion mode GC–MS analysis reduced them to 10% or less. In a study of beef samples available to the Japanese market, our analytical procedure revealed significantly higher levels of 1‐hexanol, octadecane, ethyl tetradecanoate, gamma‐nonalactone, but lower levels of delta‐decalactone, delta‐dodecalactone, and neophytadiene, in Japanese Black cattle than in beef imported from Australia.
Disintegration of Solid Foods in Human Stomach
Authors: Kong F. , Singh R.P.
Published: May 2008

ABSTRACT: Knowledge of the disintegration of solid foods in human stomach is essential to assess the bioavailability of nutrients in the gastrointestinal (GI) tract. A comprehensive review of food gastric digestion, focusing on disintegration of solid foods, is presented. Most of the research reviewed in this paper is contained in the medical, pharmaceutical, food, and nutritional literature. Stomach physiology is briefly introduced, including composition and rheological properties of gastric contents, stomach wall motility in fed/fasted states, and hydrodynamic and mechanical forces that act on the ingested food.In vivoandin vitromethods used for studying food and drug digestion in GI are summarized. Stomach emptying rate, which controls the rate of absorption of nutrients, is highly related to the disintegration of foods. This topic is highlighted with focus on the important mechanisms and the influence of chemical and physical properties of foods. Future research in this area is identified to increase our fundamental understanding of the food digestion process in the stomach as related to the food composition, material properties such as texture and microstructure, and chemical characteristics. This information is necessary to develop new guidelines for seeking innovative processing methods to manufacture foods specifically targeted for health.
Free Amino Acids in Botanicals and Botanical Preparations
Authors: Carratù B. , Boniglia C. , Giammarioli S. , Mosca M. , Sanzini E.
Published: May 2008

ABSTRACT:  Numerous studies were carried out about aminoacidic composition of vegetable proteins, but information about the free amino acid pool and the role of these substances is very incomplete. The aim of this paper was to contribute to the scarce knowledge concerning the composition of free amino acids in botanicals and botanical preparations widely used as food, in dietary supplements, and in pharmaceutical products. This work studied the composition of free amino acids, identified the major components of 19 species of plants, and evaluated the influence of different types of extraction on the amino acid profile. Amino acids were determined using an automatic precolumn derivatization with fluorenylmethyl‐chloroformate and reversed‐phase liquid chromatography with fluorescence and ultraviolet detection. The amounts of total free amino acids varied widely between plants, from approximately 12 g in 100 g of Echinacea pallida extract to less than 60 mg in the same amount of Coleus forskohlii, Garcinia cambogia, and Glycine max. In 13 plants arginine, asparagine, glutamine, proline, and γ‐aminobutyric acid were the free amino acids found in preponderant quantities. The levels of free amino acids above the quantification limit in 36 assayed samples of botanicals, extracts, and supplements are shown.
Anaemia and cigarette smoking
Authors: LEIFERT J. A.
Published: May 2008

Cigarette smoking causes numerous diseases that are associated with anaemia but the resulting low haemoglobin levels may be counterbalanced by increased red blood cell production caused by chronic exposure to carbon monoxide from cigarette smoke. Diverse mechanisms are involved in influencing the development or the course of anaemic disease in smokers. This article presents an evaluation of the current literature on the impact of cigarette smoking on various forms of anaemia.
Modeling and Control of a Magnetostrictive Tool Servo System
Authors: Panusittikorn Witoon , Ro Paul I.
Published: May 2008

A magnetostrictive actuator offers a long mechanical strain output in a broad bandwidth at a cost of a highly nonlinear magnetic hysteresis. Full utilization of this actuator in precision manufacturing requires a feedback loop as well as an advanced control scheme. A robust control scheme using sliding mode control with a variable switching gain was tailored to the nonlinear transducer. Nominal feedforward current controller that drives the magnetostriction was based on the inverse anhysteresis model. An additional switching gain based on the Lyapunov stability condition is implemented to restrain uncertainties. Compared to a traditional closed-loop control design, the proposed algorithm experimentally showed a greatly enhanced performance.
Input Shaping Control of Double-Pendulum Bridge Crane Oscillations
Authors: Singhose William , Kim Dooroo , Kenison Michael
Published: May 2008

Large amplitude oscillation of crane payloads is detrimental to safe and efficient operation. Under certain conditions, the problem is compounded when the payload creates a double-pendulum effect. Most crane control research to date has focused on single-pendulum dynamics. Several researchers have shown that single-mode oscillations can be greatly reduced by properly shaping the inputs to the crane motors. This paper builds on those previous developments to create a method for suppressing double-pendulum payload oscillations. The input shaping controller is designed to have robustness to changes in the two operating frequencies. Experiments performed on a portable bridge crane are used to verify the effectiveness of this method and the robustness of the input shaper.
The Application of Command Shaping to the Tracking Problem
Authors: Reynolds Michael C. , Meckl Peter H.
Published: May 2008

This work presents a novel technique for the solution of an optimal input for trajectory tracking. Many researchers have documented the performance advantages of command shaping, which focuses on the design of an optimal input. Nearly all research in command shaping has been centered on the point-to-point motion control problem. However, tracking problems are also an important application of control theory. The proposed optimal tracking technique extends the point-to-point motion control problem to the solution of the tracking problem. Thus, two very different problems are brought into one solution scheme. The technique uses tolerances on trajectory following to meet constraints and minimize either maneuver time or input energy. A major advantage of the technique is that hard physical constraints such as acceleration or allowable tracking error can be directly constrained. Previous methods to perform such a task involved using various weightings that lack physical meaning. The optimal tracking technique allows for fast and efficient exploration of the solution space for motion control. A solution verification technique is presented and some examples are included to demonstrate the technique.
Inhibitors of Bacterial Multidrug Efflux Pumps Potentiate Antimicrobial Photoinactivation
Authors: Tegos George P. , Masago Kayo , Aziz Fatima , Higginbotham Andrew , Stermitz Frank R. , Hamblin Michael R.
Published: May 2008

Antimicrobial photodynamic inactivation (APDI) combines a nontoxic photoactivatable dye or photosensitizer (PS) with harmless visible light to generate singlet oxygen and reactive oxygen species that kill microbial cells. Cationic phenothiazinium dyes, such as toluidine blue O (TBO), are the only PS used clinically for APDI, and we recently reported that this class of PS are substrates of multidrug efflux pumps in both gram-positive and gram-negative bacteria. We now report that APDI can be significantly potentiated by combining the PS with an efflux pump inhibitor (EPI). Killing of
Staphylococcus aureus
mediated by TBO and red light is greatly increased by coincubation with known inhibitors of the major facilitator pump (NorA): the diphenyl urea INF271, reserpine, 5′-methoxyhydnocarpin, and the polyacylated neohesperidoside, ADH7. The potentiation effect is greatest in the case of
S. aureus
mutants that overexpress NorA and least in NorA null cells. Addition of the EPI before TBO has a bigger effect than addition of the EPI after TBO. Cellular uptake of TBO is increased by EPI. EPI increased photodynamic inactivation killing mediated by other phenothiazinium dyes, such as methylene blue and dimethylmethylene blue, but not that mediated by nonphenothiazinium PS, such as Rose Bengal and benzoporphyrin derivative. Killing of
Pseudomonas aeruginosa
mediated by TBO and light was also potentiated by the resistance nodulation division pump (MexAB-OprM) inhibitor phenylalanine-arginine beta-naphthylamide but to a lesser extent than for
S. aureus
. These data suggest that EPI could be used in combination with phenothiazinium salts and light to enhance their antimicrobial effect against localized infections.
Inducible Resistance of Fish Bacterial Pathogens to the Antimicrobial Peptide Cecropin B
Authors: Sallum Ulysses W. , Chen Thomas T.
Published: May 2008

Cecropin B is a cationic antimicrobial peptide originally isolated from the diapausing pupae of the giant silk moth,
Hylphora cecropia
. Cecropin B elicits its antimicrobial effects through disruption of the anionic cell membranes of gram-negative bacteria. Previous work by our laboratory demonstrated that a constitutively expressed cecropin B transgene conferred enhanced resistance to bacterial infection in medaka. The development of antibiotic resistance by pathogenic bacteria is a growing problem. The potential for fish bacterial pathogens to develop resistance to cecropin B was addressed in this study. Four fish bacterial pathogens were selected for the study based on their importance in aquaculture.
Vibrio anguillarum
,
Vibrio vulnificus
, and
Yersinia ruckeri
all exhibited inducible resistance to cecropin B. The inducible resistance of these three pathogens was correlated with reversible changes in their ultrastructures, as observed by scanning electron microscopy.
V. anguillarum
was demonstrated to become more adhesive to a CHSE-214 cell monolayer and to cause increased cumulative mortality in medaka following exposure to cecropin B. This work demonstrates that the resistance of fish bacterial pathogens to cecropin B is inducible and suggests that resistance to other cationic antimicrobial peptides may occur through similar means. The observed changes in ultrastructure and infectivity suggest that resistance to antimicrobial peptides is an integral part of the pathogenesis of fish gram-negative bacterial pathogens.
Epidemiological Cutoffs and Cross-Resistance to Azole Drugs in
Aspergillus fumigatus
Authors: Rodriguez-Tudela Juan Luis , Alcazar-Fuoli Laura , Mellado Emilia , Alastruey-Izquierdo Ana , Monzon Araceli , Cuenca-Estrella Manuel
Published: May 2008

Antifungal susceptibility testing of molds has been standardized in Europe and in the United States.
Aspergillus fumigatus
strains with resistance to azole drugs have recently been detected and the underlying molecular mechanisms of resistance characterized. Three hundred and ninety-three isolates, including 32 itraconazole-resistant strains, were used to define wild-type populations, epidemiological cutoffs, and cross-resistance between azole drugs. The epidemiological cutoff for itraconazole, voriconazole, and ravuconazole for the wild-type populations of
A. fumigatus
was ≤1 mg/liter. For posaconazole, the epidemiological cutoff was ≤0.25 mg/liter. Up till now, isolates susceptible to itraconazole have not yet displayed resistance to other azole drugs. Cross-resistance between azole drugs depends on specific mutations in
cyp51A
. Thus, a substitution of glycine in position 54 of Cyp51A confers cross-resistance between itraconazole and posaconazole. A substitution of methionine at position 220 or a duplication in tandem of a 34-bp fragment in the
cyp51A
promoter combined with a substitution of leucine at position 98 for histidine confers cross-resistance to all azole drugs tested. The results obtained in this study will help to develop clinical breakpoints for azole drugs and
A. fumigatus
.
Assessment of
Aspergillus fumigatus
Burden in Pulmonary Tissue of Guinea Pigs by Quantitative PCR, Galactomannan Enzyme Immunoassay, and Quantitative Culture
Authors: Vallor Ana C. , Kirkpatrick William R. , Najvar Laura K. , Bocanegra Rosie , Kinney Marsha C. , Fothergill Annette W. , Herrera Monica L. , Wickes Brian L. , Graybill John R. , Patterson Thomas F.
Published: May 2008

Early diagnosis of invasive pulmonary aspergillosis is problematic in some patient groups due to the lack of rapid, sensitive, specific, and reliable diagnostic tests. Fungal burden and therapeutic efficacy were assessed by survival, quantitative culture (CFU counts), galactomannan enzyme immunoassay (GM-EIA), and quantitative PCR (qPCR) in a new guinea pig model of invasive pulmonary aspergillosis using an aerosol challenge. At 1 day postinfection, qPCR determined that the pulmonary fungal burden was 2 log
10
higher than that determined by CFU counting and increased significantly (
P
< 0.03) over time. In contrast, the tissue burden assessed by CFU counting did not rise over the course of the study. Therapy with the antifungal drug voriconazole produced statistically significant decreases in pulmonary fungal burden, as detected by CFU counting (
P
< 0.02), qPCR, and GM-EIA (both
P
< 0.0002). Daily assessment of the progression of fungal infection in serum was performed by qPCR and GM-EIA. GM-EIA demonstrated a statistically significant reduction in the fungal load on days 6 and 7 in voriconazole-treated animals compared to time-matched controls (
P
< 0.02). Confirmation of fungal tissue burden by two or more methods should provide a more precise account of the burden, allowing improved assessment of diagnostic and therapeutic strategies in invasive pulmonary aspergillosis.
Zidovudine Impairs Adipogenic Differentiation through Inhibition of Clonal Expansion
Authors: Stankov Metodi V. , Schmidt Reinhold E. , Behrens Georg M. N.
Published: May 2008

Lipoatrophy is a prevalent side effect of treatment with thymidine analogues. We wished to confine the time point of the antiadipogenic effect of zidovudine (AZT) during adipogenesis and to evaluate the antiproliferative effect of AZT on adipocyte homeostasis. We investigated the effects of AZT on adipogenesis in 3T3-F442A cells and studied their proliferation, differentiation, viability, and adiponectin expression. Cells were exposed to AZT (1 μM, 3 μM, 6 μM, and 180 μM), stavudine (d4T; 3 μM), or dideoxycytosine (ddC; 0.1 μM) for up to 15 days. Differentiation was assessed by real-time PCR and quantification of triglyceride accumulation. Proliferation and clonal expansion were determined by a [3H]thymidine incorporation assay. When they were induced to differentiate in the presence of AZT at the maximum concentration in plasma (Cmax) and lower concentrations, 3T3-F442A preadipocytes failed to accumulate cytoplasmic triacylglycerol and failed to express normal levels of the later adipogenic transcription factors, CCAAT/enhancer-binding protein α and peroxisome proliferator-activated receptor γ. AZT exerted an inhibitory effect on the completion of the mitotic clonal expansion, which resulted in incomplete 3T3-F442A differentiation and, finally, a reduction in the level of adiponectin expression. In addition, AZT impaired the constitutive proliferation in murine and primary human subcutaneous preadipocytes. In contrast, incubation with d4T and ddC at theCmaxdid not affect either preadipocyte proliferation or clonal expansion and differentiation. We conclude that the antiproliferative and antiadipogenetic effects of AZT on murine and primary human preadipocytes reveal the impact of the drug on fat tissue regeneration. These effects of the drug are expected to contribute to disturbed adipose tissue homeostasis and to be influenced by differential drug concentration and penetration in individual patients.
A Genome-Wide Proteome Array Reveals a Limited Set of Immunogens in Natural Infections of Humans and White-Footed Mice withBorrelia burgdorferi
Authors: Barbour Alan G. , Jasinskas Algimantas , Kayala Matthew A. , Davies D. Huw , Steere Allen C. , Baldi Pierre , Felgner Philip L.
Published: May 2008

Humans and other animals with Lyme borreliosis produce antibodies to a number of components of the agentBorrelia burgdorferi, but a full accounting of the immunogens during natural infections has not been achieved. Employing a protein array produced in vitro from 1,292 DNA fragments representing ∼80% of the genome, we compared the antibody reactivities of sera from patients with early or later Lyme borreliosis to the antibody reactivities of sera from controls. Overall, ∼15% of the open reading frame (ORF) products (Orfs) ofB. burgdorferiin the array detectably elicited an antibody response in humans with natural infections. Among the immunogens, 103 stood out on the basis of statistical criteria. The majority of these Orfs were also immunogenic with sera obtained from naturally infectedPeromyscus leucopusmice, a major reservoir. The high-ranking set included severalB. burgdorferiproteins hitherto unrecognized as immunogens, as well as several proteins that have been established as antigens. The high-ranking immunogens were more likely than nonreactive Orfs to have the following characteristics: (i) plasmid-encoded rather than chromosome-encoded proteins, (ii) a predicted lipoprotein, and (iii) a member of a paralogous family of proteins, notably the Bdr and Erp proteins. The newly discovered antigens included Orfs encoded by several ORFs of the lp36 linear plasmid, such as BBK07 and BBK19, and proteins of the flagellar apparatus, such as FliL. These results indicate that the majority of deduced proteins ofB. burgdorferido not elicit antibody responses during infection and that the limited sets of immunogens are similar for two different host species.
MglA and Igl Proteins Contribute to the Modulation ofFrancisella tularensisLive Vaccine Strain-Containing Phagosomes in Murine Macrophages
Authors: Bönquist Linda , Lindgren Helena , Golovliov Igor , Guina Tina , Sjöstedt Anders
Published: May 2008

TheFrancisella tularensislive vaccine strain (LVS), in contrast to itsiglCmutant, replicates in the cytoplasm of macrophages. We studied the outcome of infection of the murine macrophagelike cell line J774A.1 with LVS and withiglC,iglD, andmglAmutants, the latter of which is deficient in a global regulator. Compared to LVS, all of the mutants showed impaired intracellular replication up to 72 h, and the number of themglAmutant bacteria even decreased. Colocalization with LAMP-1 was significantly increased for all mutants compared to LVS, indicating an impaired ability to escape into the cytoplasm. A lysosomal acidity-dependent dye accumulated in approximately 40% of the vacuoles containing mutant bacteria but not at all in vacuoles containing LVS. Preactivation of the macrophages with gamma interferon inhibited the intracellular growth of all strains and significantly increased acidification of phagosomes containing the mutants, but it only slightly increased the LAMP-1 colocalization. The intracellular replication and phagosomal escape of theiglCandiglDmutants were restored by complementation intrans. In conclusion, the IglC, IglD, and MglA proteins each directly or indirectly critically contribute to the virulence ofF. tularensisLVS, including its intracellular replication, cytoplasmic escape, and inhibition of acidification of the phagosomes.
A Triacylated Lipoprotein fromMycoplasma genitaliumActivates NF-κB through Toll-Like Receptor 1 (TLR1) and TLR2
Authors: Shimizu Takashi , Kida Yutaka , Kuwano Koichi
Published: May 2008

Mycoplasma genitaliumis a sexually transmitted bacterial pathogen that causes nongonococcal chlamydia-negative urethritis, mucopurulent cervicitis, endometritis, pelvic inflammatory disease, and tubal factor infertility in humans. However, pathogenic agents that induce inflammatory responses have not been identified inM. genitalium. In this study, we examined the involvement of Toll-like receptors (TLRs) in activation of the immune response by a lipoprotein fromM. genitaliumand their active component responsible for NF-κB activation. The Triton X-114 detergent phase ofM. genitaliumwas found to induce NF-κB through TLR2. The active component of the Triton X-114 detergent phase was a lipoprotein precursor, MG149. The activation of NF-κB by MG149 was inhibited by a dominant negative (DN) construct of TLR1 but not by a DN construct of TLR6. These results indicate that the activation of NF-κB by MG149 is dependent on TLR1 and TLR2. A synthetic lipopeptide derived from MG149 containing three acyl chains also induced NF-κB through TLR1 and TLR2. Thus, the results show that MG149, a triacylated lipoprotein fromM. genitalium, activates NF-κB through TLR1 and TLR2.
Interaction of
Porphyromonas gingivalis
with Oral Streptococci Requires a Motif That Resembles the Eukaryotic Nuclear Receptor Box Protein-Protein Interaction Domain
Authors: Daep Carlo Amorin , Lamont Richard J. , Demuth Donald R.
Published: May 2008

Porphyromonas gingivalis
initially colonizes the oral cavity by interacting with organisms in supragingival plaque, such as the oralis group of oral streptococci. This interaction involves the association of the streptococcal antigen I/II with the minor fimbrial antigen (Mfa1) of
P. gingivalis
. Our previous studies showed that a peptide (BAR) derived from antigen I/II inhibits
P. gingivalis
adherence and subsequent biofilm formation on streptococcal substrates. In addition, screening a combinatorial peptide library identified select amino acid substitutions in the NITVK active region of BAR that increased the adherence of
P. gingivalis
to streptococci. Here we report that incorporating these residues in a synthetic peptide results in more-potent inhibition of
P. gingivalis
adherence and biofilm formation (I
50
[50% inhibition] at 0.52 μM versus I
50
at 1.25 μM for BAR). In addition, a second structural motif in BAR, comprised of the amino acids KKVQDLLKK, was shown to contribute to
P. gingivalis
adherence to streptococci. Consistent with this, the KKVQDLLKK and NITVK motifs are conserved only in antigen I/II proteins expressed by the oralis group of streptococci, which interact with
P. gingivalis
. Interestingly, the primary and secondary structures and the functional characteristics of the amphipathic VQDLL core α-helix resemble the consensus nuclear receptor (NR) box protein-protein interacting domain sequence (LXXLL) of eukaryotes. BAR peptides containing amino acid substitutions with the potential to disrupt the secondary structure of VQDLL were less-effective inhibitors of
P. gingivalis
adherence and biofilm formation, suggesting that the α-helical character of VQDLL is important. Furthermore, replacing the lysines that flank VQDLL with acidic amino acids also reduced inhibitory activity, suggesting that the association of VQDLL with Mfa1 may be stabilized by a charge clamp. These results indicate that the Mfa1-interacting interface of streptococcal antigen I/II encompasses both the KKVQDLLKK and NITVK motif and suggest that the adherence of
P. gingivalis
to streptococci is driven by a protein-protein interaction domain that resembles the eukaryotic NR box. Thus, both motifs must be taken into account in designing potential peptidomimetics that target
P. gingivalis
adherence and biofilm formation.
d
-Alanylation of Lipoteichoic Acid Contributes to the Virulence of
Streptococcus suis
Authors: Fittipaldi Nahuel , Sekizaki Tsutomu , Takamatsu Daisuke , Harel Josée , Domínguez-Punaro María de la Cruz , Von Aulock Sonja , Draing Christian , Marois Corinne , Kobisch Marylène , Gottschalk Marcelo
Published: May 2008

We generated by allelic replacement a Δ
dltA
mutant of a virulent
Streptococcus suis
serotype 2 field strain and evaluated the contribution of lipoteichoic acid (LTA)
d
-alanylation to the virulence traits of this swine pathogen and zoonotic agent. The absence of LTA
d
-alanylation resulted in increased susceptibility to the action of cationic antimicrobial peptides. In addition, and in contrast to the wild-type strain, the Δ
dltA
mutant was efficiently killed by porcine neutrophils and showed diminished adherence to and invasion of porcine brain microvascular endothelial cells. Finally, the Δ
dltA
mutant was attenuated in both the CD1 mouse and porcine models of infection, probably reflecting a decreased ability to escape immune clearance mechanisms and an impaired capacity to move across host barriers. The results of this study suggest that LTA
d
-alanylation is an important factor in
S. suis
virulence.
The Capsule Sensitizes
Streptococcus pneumoniae
to α-Defensins Human Neutrophil Proteins 1 to 3
Authors: Beiter Katharina , Wartha Florian , Hurwitz Robert , Normark Staffan , Zychlinsky Arturo , Henriques-Normark Birgitta
Published: May 2008

Streptococcus pneumoniae
is a major cause of morbidity and mortality worldwide. Its polysaccharide capsule causes resistance to phagocytosis and interferes with the innate immune system's ability to clear infections at an early stage. Nevertheless, we found that encapsulated pneumococci are sensitive to killing by a human neutrophil granule extract. We fractionated the extract by high-performance liquid chromatography and identified α-defensins by mass spectrometry as the proteins responsible for killing pneumococci. Analysis of sensitivity to the commercial α-defensins human neutrophil proteins 1 to 3 (HNP1-3) confirmed these findings. We analyzed the sensitivities of different pneumococcal strains to HNP1-3 and found that encapsulated strains are efficiently killed at physiological concentrations (7.5 μg/ml). Surprisingly, nonencapsulated, nonvirulent pneumococci were significantly less sensitive to α-defensins. The proposed mechanisms of α-defensin resistance in nonencapsulated pneumococci is surface charge modification, e.g., by introduction of positive charge by
d
-alanylation of surface-exposed lipoteichoic acids. These mechanisms are surmounted by the presence of the capsule, which we hypothesize is masking these charge modifications. Hence, α-defensins in the phagolysosome of neutrophils possibly contribute to intracellular killing after antibody-mediated opsonophagocytosis of encapsulated pneumococci.
Clinical connexions
Authors: Alldredge B
Published: May 2008

The past decade of scientific research has seen a proliferation of information regarding the identification and biophysical properties of gap junctions and their constituents, connexin proteins. Advances in biological research techniques have elucidated a ubiquitous distribution and dynamic regulation of connexins and gap junctions. The gap junction is the primary component of the electrical synapse that couples cells together morphologically and functionally. The importance of gap junctions to homeostasis is reflected by the observance of their dysfunction in a myriad of pathologies. Singular studies noting an aetiological association of connexins and gap junctions in pathologies have also been rapidly accumulating. This paper will circumscribe these studies of pathology and connexins to review their clinical implications.
mTOR in squamous cell carcinoma of the oesophagus: a potential target for molecular therapy?
Authors: Boone J , Kate F J W Ten , Offerhaus G J A , van Diest P J , Rinkes I H M Borel , van Hillegersberg R
Published: May 2008

Aims:

The mammalian target of rapamycin (mTOR), an important regulator of protein translation and cell proliferation, is activated in various malignancies. In a randomised controlled trial of advanced renal cell carcinoma patients, targeted therapy to mTOR by means of rapamycin analogues has been shown to significantly improve survival. An in vitro study has revealed that mTOR is activated in oesophageal squamous cell carcinoma (OSCC) cell lines and that mTOR expression is inhibited by rapamycin. The objectives of this histological study were to determine the proportion of OSCC tissues with activated mTOR (p-mTOR) expression, thereby assessing the percentage of patients with OSCC that would possibly benefit from neoadjuvant rapamycin therapy, and to identify the clinicopathological features of these potentially rapamycin-sensitive tumours.

Methods:

The expression of p-mTOR (Ser2448) was immunohistochemically assessed in a validated tissue microarray comprising triplicate tissue biopsy cores of 108 formalin-fixed, paraffin-embedded OSCCs. Staining results were correlated with clinicopathological data.

Results:

Normal oesophageal epithelium was negative for p-mTOR. Activated mTOR expression was located in the cytoplasm of oesophageal tumour cells. 26 (25%) of 105 assessable OSCCs showed tumour cells with positive staining for activated mTOR. Activated mTOR expression was associated with a lesser degree of differentiation only (p = 0.024). No correlation was detected between p-mTOR and the proliferation marker Ki-67.

Conclusions:

Activated mTOR can be detected in one-quarter of OSCCs. Since this subset of patients may potentially benefit from mTOR inhibiting therapy, a phase II clinical trial of neoadjuvant mTOR-inhibiting therapy in patients with OSCC may be considered.
Integration of conventional cytogenetics, comparative genomic hybridisation and interphase fluorescence in situ hybridisation for the detection of genomic rearrangements in acute leukaemia
Authors: McGrattan P , Campbell S , Cuthbert R , Jones F G C , McMullin M F , Humphreys M
Published: May 2008

Aims:

To screen for genomic imbalances in patients with acute leukaemia using conventional (G-banding) and molecular (comparative genomic hybridisation (CGH) and fluorescence in situ hybridisation (FISH)) methods to determine whether an integrative screening approach increases abnormality detection rate.

Methods:

G-banded analysis was performed on unstimulated bone marrow (BM) or peripheral blood (PB) cells after short-term (24-hour) culture. CGH was performed on reference (control) and neoplastic (test patient) genomic DNA extracted from BM or PB samples. Interphase FISH (i-FISH) was selectively carried out at disease diagnosis on patients with acute lymphoblastic leukaemia and acute myeloid leukaemia using conventional methods.

Results:

Genomic rearrangements were detected in 4, 7 and 6 patients using G-banding, CGH and i-FISH respectively. Discordance in results between G-banding, CGH and/or i-FISH was found in 7 of the 12 patients screened. G-banding and CGH, when used individually, detected a genomic imbalance/rearrangement in 33.3% and 58.3%, respectively, of the patients screened. However, when both screening methods were integrated, the abnormality detection rate increased to 66.7%. This detection rate increased further to 75.0% with the use of i-FISH screening.

Conclusions:

The advantages and disadvantages of using G-banding, CGH and i-FISH as either stand-alone or integrated screening methods for the detection and characterisation of genomic imbalances in acute leukaemia are clearly demonstrated. Abnormality detection rate significantly increased when an integrated screening approach was employed which could potentially provide valuable information for risk stratification in patients with acute leukaemia.
Tobacco use and cessation counselling: cross-country. Data from the Global Health Professions Student Survey (GHPSS), 2005–7
Authors: Warren C W , Jones N R , Chauvin J
Published: May 2008

Background:

Brief intervention by a health professional can substantially increase smoking cessation rates among patients. However, few studies have collected information on tobacco use and training to provide cessation counselling among health professional students.

Objective:

To examine tobacco use prevalence and tobacco cessation training among students pursuing advanced degrees in health professions.

Methods:

The Global Health Professions Student Survey (GHPSS) has been conducted among third-year students attending dental, medical, nursing and pharmacy schools. The GHPSS was conducted in schools during regular lectures and class sessions. GHPSS follows an anonymous, self-administered format for data collection.

Results:

The GHPSS was completed by at least one of the four target disciplines in 31 countries between 2005 and 2007 for a total of 80 survey sites. In 47 of the 80 sites, over 20% of the students currently smoked cigarettes; and in 29 of 77 sites, over 10% of the students currently used other tobacco products. GHPSS data showed that the majority of health professional students recognised that they are role models in society, believed that they should receive training on counselling patients to quit using tobacco, but in 73 of 80 sites less than 40% of the students reported they received such training.

Conclusions:

Health professional schools, public health organisations and education officials should discourage tobacco use among health professionals and work together to design and implement programmes that train all health professionals in effective cessation counselling techniques. If the goal of the tobacco control community is to reduce substantially the use of tobacco products, then resources should be invested in improving the quality of education of health professionals with respect to tobacco control.
CLASSIFICATION OF NONCOMMUTING QUADRILATERALS OF FACTORS
Authors: GROSSMAN PINHAS , IZUMI MASAKI
Published: May 2008

A quadrilateral of factors is an irreducible inclusion of factors N ⊂ M with intermediate subfactors P and Q such that P and Q generate M and the intersection of P and Q is N. We investigate the structure of a noncommuting quadrilateral of factors with all the elementary inclusions P ⊂ M, Q ⊂ M, N ⊂ P, and N ⊂ Q 2-supertransitive. In particular, we classify noncommuting quadrilaterals with the indices of the elementary subfactors less than or equal to 4. We also compute the angles between P and Q for quadrilaterals coming from α-induction and asymptotic inclusions.
THE PARAMETER SPACE OF A QUADRATIC FAMILY OF POLYNOMIAL MAPS OF ℂ2
Authors: ANDREI ALINA
Published: May 2008

In this paper, we study the parameter space of the quadratic polynomial family fλ,μ(z, w) = (λz + w2, μw + z2), which exhibits interesting dynamics. Two distinct subsets of the parameter space are studied as appropriate analogs of the one-dimensional Mandelbrot set and some of their properties are proved by using Lyapunov exponents. In the more general context of holomorphic families of regular maps, we show that the sum of the Lyapunov exponents is a plurisubharmonic function of the parameter, and pluriharmonic on the set of expanding maps. Moreover, for the family fλ,μ, we prove that the sum of the Lyapunov exponents is continuous.
POTENTIAL ENERGY AS A PLUCKING CRITERION FOR LIQUID CLUSTER SIMULATIONS
Authors: COPPOCK JOSEPH D. , BOMSTAD BENJAMIN T. , HUEBNER DAVID T. , STREY JACQUELYN P. , MOORE BRIAN G.
Published: May 2008

We have investigated the liquid state of atomic clusters interacting through a classical pair-wise Lennard–Jones 6–12 potential, using constant energy molecular dynamics simulations. For larger clusters (N ≳ 500–600 atoms) desorption events are frequent and a cluster in the liquid state eventually always converts to a solid state. To study the cluster as it cools, one must isolate the central cluster from the desorbed atoms. In this paper, we investigate using the atomic potential energy as a very simple criterion for removing desorbed atoms from the simulation, and examine the spatial profile of atomic potential energy in various size liquid and solid clusters.
INHOMOGENEOUS AND SELF-ORGANIZED TEMPERATURE IN SCHELLING-ISING MODEL
Authors: MÜLLER KATHARINA , SCHULZE CHRISTIAN , STAUFFER DIETRICH
Published: May 2008

The Schelling model of 1971 is a complicated version of a square-lattice Ising model at zero temperature, to explain urban segregation, based on the neighbor preferences of the residents, without external reasons. Various versions between Ising and Schelling models give about the same results. Inhomogeneous "temperatures" T do not change the results much, while a feedback between segregation and T leads to a self-organization of an average T.
INVESTIGATION OF ELECTION RESULTS, NUMBERS OF PARTY MEMBERS, AND OPINION POLLS IN GERMANY
Authors: SCHNEIDER JOHANNES J. , HIRTREITER CHRISTIAN
Published: May 2008

Our publication focuses on two different but related topics in politics: in the first part of this publication, we investigate the influence of election results in the elections for the parliaments of the German states and for the German Diet (federal parliament) on the member numbers of the largest parties in the various states. In the second part of this publication, we consider the correlations between opinion polls and election results and focus on the question whether real election results can be predicted by opinion polls.
FRACTIONAL MARKET MODEL AND ITS VERIFICATION ON THE WARSAW STOCK EXCHANGE
Authors: KOZŁOWSKA MARZENA , KASPRZAK ANDRZEJ , KUTNER RYSZARD
Published: May 2008

We analyzed the rising and relaxation of the cusp-like local peaks superposed with oscillations which were well defined by the Warsaw Stock Exchange index WIG in a daily time horizon. We found that the falling paths of all index peaks were described by a generalized exponential function or the Mittag-Leffler (ML) one superposed with various types of oscillations. However, the rising paths (except the first one of WIG which rises exponentially and the most important last one which rises again according to the ML function) can be better described by bullish anti-bubbles or inverted bubbles.2–4 The ML function superposed with oscillations is a solution of the nonhomogeneous fractional relaxation equation which defines here our Fractional Market Model (FMM) of index dynamics which can be also called the Rheological Model of Market. This solution is a generalized analog of an exactly solvable fractional version of the Standard or Zener Solid Model of viscoelastic materials commonly used in modern rheology.5 For example, we found that the falling paths of the index can be considered to be a system in the intermediate state lying between two complex ones, defined by short and long-time limits of the Mittag-Leffler function; these limits are given by the Kohlrausch-Williams-Watts (KWW) law for the initial times, and the power-law or the Nutting law for asymptotic time. Some rising paths (i.e., the bullish anti-bubbles) are a kind of log-periodic oscillations of the market in the bullish state initiated by a crash. The peaks of the index can be viewed as precritical or precrash ones since:

(i) the financial market changes its state too early from the bullish to bearish one before it reaches a scaling region (defined by the diverging power-law of return per unit time), and

(ii) they are affected by a finite size effect.

These features could be a reminiscence of a significant risk aversion of the investors and their finite number, respectively. However, this means that the scaling region (where the relaxations of indexes are described by the KWW law or stretched exponential decay) was not observed. Hence, neither was the power-law of the instantaneous returns per unit time observed. Nevertheless, criticality or crash is in a natural way contained in our FMM and we found its "finger print".