bluuebunny/crossref_metadata_2025 huggingface dataset:
The Immunobiology of Mushrooms
Authors: Borchers Andrea T. , Krishnamurthy Anita , Keen Carl L. , Meyers Frederick J. , Gershwin M. Eric
Published: May 2008

There has been enormous interest in the biologic activity of mushrooms and innumerable claims have been made that mushrooms have beneficial effects on immune function with subsequent implications for inhibition of tumor growth. The majority of these observations are anecdotal and often lack standardization. However, there remains considerable data on both in vitro and in vivo effects that reflect on the potential of mushroom compounds to influence human immunity. A number of these effects are beneficial but, unfortunately, many responses are still characterized based on phenomenology and there is more speculation than substance. With respect to tumor biology, although many neoplastic lesions are immunogenic, tumor antigens frequently are self antigens and induce tolerance and many patients with cancer exhibit suppressed immune responses, including defective antigen presentation. Therefore, if and when mushroom extracts are effective, they more likely function as a result of improved antigen presentation by dendritic cells than by a direct cytopathic effect. In this review we attempt to place these data in perspective, with a particular focus on dendritic cell populations and the ability of mushroom extracts to modulate immunity. There is, at present, no scientific basis for the use of either mushrooms or mushroom extracts in the treatment of human patients but there is significant potential for rigorous research to understand the potential of mushrooms in human disease and thence to focus on appropriate clinical trials to demonstrate effectiveness and/ or potential toxicity.
Effect of Dietary Selenium on the Promotion of Hepatocarcinogenesis by 3,3′, 4,4′-Tetrachlorobiphenyl and 2,2′, 4,4′, 5,5′-Hexachlorobiphenyl
Authors: Stemm Divinia N. , Tharappel Job C. , Lehmler Hans-Joachim , Srinivasan Cidambi , Morris J. Steven , Spate Vickie L. , Robertson Larry W. , Spear Brett T. , Glauert Howard P.
Published: May 2008

Polychlorinated biphenyls (PCBs) are persistent organic pollutants that have promoting activity in the liver. PCBs induce oxidative stress, which may influence carcinogenesis. Epidemiological studies strongly suggest an inverse relationship between dietary selenium (Se) and cancer. Despite evidence linking Se deficiency to hepatocellular carcinoma and liver necrosis, the underlying mechanisms for Se cancer protection in the liver remain to be determined. We examined the effect of dietary Se on the tumor promoting activities of two PCBs congeners, 3,3′, 4,4′-tetrachlorobiphenyl (PCB-77) and 2,2′, 4,4′, 5,5′-hexachlorobiphenyl (PCB-153) using a 2-stage carcinogenesis model. An AIN-93 torula yeast-based purified diet containing 0.02 (deficient), 0.2 (adequate), or 2.0 mg (supplemental) selenium/kg diet was fed to Sprague-Dawley female rats starting ten days after administering a single dose of diethylnitrosamine (150 mg/kg). After being fed the selenium diets for 3 weeks, rats received four i.p. injections of either PCB-77 or PCB-153 (150 μ mol/kg) administered every 14 days. The number of placental glutathione S-transferase (PGST)-positive foci per cm3 and per liver among the PCB-77–treated rats was increased as the Se dietary level increased. Unlike PCB-77, rats receiving PCB-153 did not show the same Se dose-response effect; nevertheless, Se supplementation did not confer protection against foci development. However, the 2.0 ppm Se diet reduced the mean focal volume, indicating a possible protective effect by inhibiting progression of preneoplastic lesions into larger foci. Cell proliferation was not inhibited by Se in the liver of the PCB-treated groups. Se did not prevent the PCB-77–induced decrease of hepatic Se and associated reduction in glutathione peroxidase (GPx) activity. In contrast, thioredoxin reductase (TrxR) activity was not affected by the PCBs treatment or by Se supplementation. These findings indicate that Se does not inhibit the number of PGST-positive foci induced during promotion by PCBs, but that the size of the lesions may be inhibited. The effects of Se on altered hepatic foci do not correlate with its effects on GPx and TrxR.
B-Type Natriuretic Peptide Decreases Gastric Emptying and Absorption
Authors: Addisu Anteneh , Gower William R. , Landon Carol S. , Dietz John R.
Published: May 2008

Natriuretic peptides have been shown to decrease contractility of isolated gastric smooth muscle cells. However there is a paucity of research showing whether this effect has functional significance in the whole animal. The objective of this study was to test whether intravenously administered B-type Natriuretic Peptide (BNP) has an effect on gastric emptying and/or absorption in a whole animal mouse model. C57BL/6-Wild-type (WT) and Natriuretic Peptide Receptor type A (NPR-A) knockout (KO) mice were used in these studies. Gastric contractility was examined in anesthetized mice before and after BNP vs. vehicle injection. Gastric emptying of gavage fed 70 Kilo Dalton (kDa) FITC-dextran and absorption of 4 kDa FITC-dextran were compared in BNP vs. vehicle treated conscious WT and KO mice. BNP decreased gastric contractility (measured in change in intragastric pressure) from 2.26 ± 0.29 to 1.44 ± 0.11 mmHg ( P < 0.05), pressure returned to 2.08 ± 0.17 after 5 BNP half-lives ( P < 0.05). There was no significant change in the vehicle or KO. BNP also decreased gastric emptying in WT mice compared to vehicle, 87.8 ± 0.8% vs. 97.3 ± 1.04% ( P < 0.05) and this effect showed a dose-response relationship. In KO mice emptying was 95.8 ± 0.5% (BNP) vs. 91.7 ± 0.7% (Vehicle) ( P > 0.05). The absorption in WT mice was 28.2 ± 7.8 (relative fluorescence units) for BNP vs. 91 ± 25.9 for vehicle ( P < 0.05). For KO mice absorption was 64.3 ± 14.9 for BNP vs. 60.6 ± 17.4 for vehicle ( P > 0.05). The results show that BNP decreases intragastric pressure, emptying and absorption by acting via the NPR-A receptor. We postulate that this effect is aimed at decreasing preload through decreased water and electrolyte absorption from the GI tract and may also be responsible for the symptoms of impaired gastrointestinal function observed in heart failure patients.
Antiallergic Effects of Vitis amurensis on Mast Cell–Mediated Allergy Model
Authors: Kim Sang-Hyun , Kwon Taeg Kyu , Shin Tae-Yong
Published: May 2008

In this study, we investigated the effect of the methanol extract of fruits of Vitis amurensis Rupr. (Vitaceae; MEVA) on the mast cell–mediated allergy model and studied the possible mechanism of action. Mast cell–mediated allergic disease is involved in many diseases, such as asthma and sinusitis. The discovery of drugs for the treatment of allergic disease is an important subject in human health. MEVA inhibited compound 48/80–induced systemic reactions and serum histamine release in a dose-dependent manner in mice. MEVA decreased immunoglobulin E (IgE)–mediated local allergic reactions, passive cutaneous anaphylaxis. MEVA dose-dependently reduced histamine release from mast cells activated by compound 48/80 or IgE. The inhibitory effect of MEVA on histamine release was mediated by the modulation of intracellular calcium. In addition, MEVA attenuated the phorbol 12-myristate 13-acetate and calcium ionophore A23187 (PMACI)–stimulated secretion of tumor necrosis factor-α, interleukin-6 (IL-6), and IL-8 in human mast cells. The inhibitory effect of MEVA on these proinflammatory cytokines was p38 mitogen-activated protein kinase and nuclear factor-κB (NF-κB) dependent. Our findings provide evidence that MEVA inhibits mast cell–derived, immediate-type allergic reactions and involvement of proinflammatory cytokines, p38 MAPK, and NF-κB in these effects.
Spectrin and Ankyrin-Based Cytoskeletons at Polarized Domains in Myelinated Axons
Authors: Susuki Keiichiro , Rasband Matthew N.
Published: May 2008

In myelinated nerve fibers, action potential initiation and propagation requires that voltage-gated ion channels be clustered at high density in the axon initial segments and nodes of Ranvier. The molecular organization of these subdomains depends on specialized cytoskeletal and scaffolding proteins such as spectrins, ankyrins, and 4.1 proteins. These cytoskeletal proteins are considered to be important for 1) formation, localization, and maintenance of specific integral membrane protein complexes, 2) a barrier restricting the diffusion of both cytoplasmic and membrane proteins to distinct regions or compartments of the cell, and 3) stabilization of axonal membrane integrity. Increased insights into the role of the cytoskeleton could provide important clues about the pathophysiology of various neurological disorders.
Neuronal Maturation in an Experimental Model of Brain Tissue Heterotopia in the Lung
Authors: Quemelo Paulo Roberto Veiga , Peres Luiz Cesar
Published: May 2008

Neural maturation involves diverse interaction and signaling mechanisms that are essential to the development of the nervous system. However, little is known about the development of neurons in heterotopic brain tissue in the lung, a rare abnormality observed in malformed babies and fetuses. The aim of this study was to identify the neurons and to investigate their maturation in experimental brain tissue heterotopia during fetal and neonatal periods. The fetuses from 24 pregnant female Swiss mice were used to induce brain tissue heterotopia on the 15th gestational day. Briefly, the brain of one fetus of each dam was extracted, disaggregated, and injected into the right hemithorax of siblings. Six of these fetuses with pulmonary brain tissue implantation were collected on the 18th gestational day (group E18), and six others were collected on the 8th postnatal day (group P8). The brain of each fetus from dams not submitted to any experimental procedure was collected on the 18th gestational day (group CE18) and on the 8th postnatal day (group CP8) to serve as a control for neuronal quantitation and maturation. Immunohistochemical staining of NeuN was used to assess neuron quantity and maturation. The NeuN labeling index was greater in the postnatal period than in the fetal period for the experimental and control groups (P8 > E18 and CP8 > CE18), although there were fewer neurons in experimental than in control groups (P8 < CP8 and E18 < CE18) ( P < 0.005). These results indicate that fetal neuroblasts/neurons not only survive a dramatic event such as mechanical disaggregation, in the same way as it happens in human cases, but also they retain their development in heterotopia, irrespective of local tissue influences.
Apolipoprotein E Gene Polymorphism and Serum Lipid Levels in the Guangxi Hei Yi Zhuang and Han Populations
Authors: Yin Ruixing , Pan Shangling , Wu Jinzhen , Lin Weixiong , Yang Dezhai
Published: May 2008

Hei Yi Zhuang is an isolated subgroup of the Zhuang minority in China. Little is known about the distribution of apolipoprotein (apo) E genetic variations and its role in lipid metabolism in this population. The present study was undertaken to compare the effect of apoE gene polymorphism on serum lipid levels between the Guangxi Hei Yi Zhuang and Han populations. A total of 873 subjects of Hei Yi Zhuang and 867 participants of Han Chinese were surveyed by a stratified randomized cluster sampling. Genotyping of apoE was performed using polymerase chain reaction and restriction fragment length polymorphism. The frequencies of  2,  3, and  4 alleles were 15.23%, 79.84%, and 4.93% in Hei Yi Zhuang, and 9.23%, 81.43%, and 9.34% in Han ( P < 0.001); respectively. The frequencies of  2/ 2,  2/ 3,  2/ 4,  3/ 3,  3/ 4, and  4/ 4 genotypes were 4.70%, 17.86%, 3.21%, 68.16%, 5.50%, and 0.57% in Hei Yi Zhuang, and 2.54%, 9.23%, 4.15%, 70.70%, 12.23%, and 1.15% in Han ( P < 0.001); respectively. Total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and apoB levels were lower in Hei Yi Zhuang than in Han ( P < 0.01–0.001), but high-density lipoprotein cholesterol (HDL-C) levels and the ratio of apoA-I to apoB were higher in Hei Yi Zhuang than in Han ( P < 0.001 for each). There were significant differences in TC, HDL-C, LDL-C, and apoB levels among the six genotypes in both ethnic groups ( P < 0.01–0.001). Hyperlipidemia was positively correlated with age, body mass index, hypertension, alcohol consumption, and apoE allele in both populations ( P < 0.05–0.001). TC, LDL-C, and apoB levels were positively correlated, and HDL-C levels were negatively associated with apoE genotypes in both ethnic groups ( P < 0.001 for all). The differences in the lipid profiles between Hei Yi Zhuang and Han Chinese might partly attribute to the differences in apoE genotypic and allelic frequencies.
The Nonsteroidal Anti-Inflammatory Drug NS398 Reactivates SPARC Expression via Promoter Demethylation to Attenuate Invasiveness of Lung Cancer Cells
Authors: Pan Mei-Ren , Chang Hui-Chiu , Chuang Lea-Yea , Hung Wen-Chun
Published: May 2008

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to exhibit potent anticancer effects in vitro and in vivo. One of the mechanisms by which NSAIDs suppress tumorigenesis is inhibition of angiogenesis and metastasis. In this study, we used a microarray system to study the change of expression profile of metastasis-related genes regulated by NS398, a NSAID and a cyclooxygenase-2 (COX-2) inhibitor. We found that several negative regulators of cell invasion, including secreted protein acidic and rich in cysteine (SPARC), thrombospondin 1 (TSP-1), thrombospondin 3 (TSP-3), and tissue inhibitors of matrix metalloproteinase-2 (TIMP-2) are upregulated by NS398. In addition, we demonstrated that upregulation of SPARC expression by NS398 in human lung cancer cells is mediated by promoter demethylation and associated with a decrease in DNA methyltransferase (DNMT) expression. This is the first report to show that NS398 can inhibit the expression of DNMT1 and 3b. Functional assay indicated that SPARC is a critical mediator for NS398 to inhibit cell invasion. Our results provide new insights for the understanding of the anticancer actions of NSAIDs.
Mammalian Long-Chain Acyl-CoA Synthetases
Authors: Soupene Eric , Kuypers Frans A.
Published: May 2008

Acyl-CoA synthetase enzymes are essential for de novo lipid synthesis, fatty acid catabolism, and remodeling of membranes. Activation of fatty acids requires a two-step reaction catalyzed by these enzymes. In the first step, an acyl-AMP intermediate is formed from ATP. AMP is then exchanged with CoA to produce the activated acyl-CoA. The release of AMP in this reaction defines the superfamily of AMP-forming enzymes. The length of the carbon chain of the fatty acid species defines the substrate specificity for the different acyl-CoA synthetases (ACS). On this basis, five sub-families of ACS have been characterized. The purpose of this review is to report on the large family of mammalian long-chain acyl-CoA synthetases (ACSL), which activate fatty acids with chain lengths of 12 to 20 carbon atoms. Five genes and several isoforms generated by alternative splicing have been identified and limited information is available on their localization. The structure of these membrane proteins has not been solved for the mammalian ACSLs but homology to a bacterial form, whose structure has been determined, points at specific structural features that are important for these enzymes across species. The bacterial form acts as a dimer and has a conserved short motif, called the fatty acid Gate domain, that seems to determine substrate specificity. We will discuss the characterization and identification of the different spliced isoforms, draw attention to the inconsistencies and errors in their annotations, and their cellular localizations. These membrane proteins act on membrane-bound substrates probably as homo- and as heterodimer complexes but have often been expressed as single recombinant isoforms, apparently purified as monomers and tested in Triton X-100 micelles. We will argue that such studies have failed to provide an accurate assessment of the activity and of the distinct function of these enzymes in mammalian cells.
Zinc Supplementation Inhibits Hepatic Apoptosis in Mice Subjected to a Long-Term Ethanol Exposure
Authors: Zhou Zhanxiang , Liu Jie , Song Zhenyuan , McClain Craig J. , Kang Y. James
Published: May 2008

Hepatocyte apoptosis has been documented in both clinical and experimental alcoholic liver disease. This study was undertaken to examine the effect of dietary zinc supplementation on hepatic apoptosis in mice subjected to a long-term ethanol exposure. Male adult 129S6 mice fed an ethanol-containing liquid diet for 6 months developed hepatitis, as indicated by neutrophil infiltration and elevation of hepatic keratinocyte chemoattractant (KC) and monocyte chemoattractant protein-1 (MCP-1) levels. Apoptotic cell death was detected in ethanol-exposed mice by a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and was confirmed by the increased activities of caspase-3 and -8. Zinc supplementation attenuated alcoholic hepatitis and reduced the number of TUNEL-positive cells in association with inhibition of caspase activities. Ethanol exposure caused oxidative stress, as indicated by reactive oxygen species accumulation, mitochondrial glutathione depletion, and decreased metallothionein levels in the liver, which were suppressed by zinc supplementation. The mRNA levels of tumor necrosis factor (TNF)-α, TNF-R1, FasL, Fas, Fas-associated factor-1, and caspase-3 in the liver were upregulated by ethanol exposure, which were attenuated by zinc supplementation. Zinc supplementation also prevented ethanol-elevated serum and hepatic TNF-α levels and TNF-R1 and Fas proteins in the liver. In conclusion, zinc supplementation prevented hepatocyte apoptosis in mice subjected to long-term ethanol exposure, and the action of zinc is likely through suppression of oxidative stress and death receptor-mediated pathways.
Effects of 3,5-Diiodo-L-Thyronine Administration on the Liver of High Fat Diet-Fed Rats
Authors: Grasselli Elena , Canesi Laura , Voci Adriana , De Matteis Rita , Demori Ilaria , Fugassa Emilia , Vergani Laura
Published: May 2008

In rats fed a high fat diet (HFD), long-term administration of 3,5-diiodo-L-thyronine (T2), a naturally occurring iodothyronine, was shown to reduce body-weight gain, fat mass, and hepatic lipid accumulation. This work was aimed at investigating the mechanisms of T2 action in the liver of HFD rats. The results show that HFD induces liver lipid peroxidation and stimulates the activity of enzymes involved in hydrogen peroxide (H2O2) metabolism, catalase in particular. Moreover, quantitative RT-PCR revealed HFD-induced upregulation of the transcription factor PPARα, as well as of metallothionein isoforms (MT-1 and MT-2). T2 administration prevented the HDF-induced lipid peroxidation, as well as the increase in H2O2 metabolism, and reduced the upregulation of both PPARα and MT-2. These data demonstrate that in the liver of HFD rats, T2 prevents both lipid accumulation and oxidative stress associated with increased fat metabolism.
High Dietary Fat Exacerbates Arsenic-Induced Liver Fibrosis in Mice
Authors: Wu Jun , Liu Jie , Waalkes Michael P. , Cheng Ming-Liang , Li Ling , Li Cheng-Xiu , Yang Qing
Published: May 2008

Many factors could potentially affect the process of arsenic-induced liver fibrosis. The present study was undertaken to examine the effect of high fat diet on arsenic-induced liver fibrosis and preneoplastic changes. Mice were given sodium arsenite (As3+, 200 ppm) or sodium arsenate (As5+, 200 ppm) in the drinking water for 10 months, and provided a normal diet or a diet containing 20% added fat. Serum aspartate aminotransferase (AST), indicative of liver injury, was elevated in both arsenite and arsenate groups, and a high fat diet further increased these levels. Histopathology (H&E and Masson stain) showed that liver inflammation, steatosis (fatty liver), hepatocyte degeneration, and fibrosis occurred with arsenic alone, but their severity was markedly increased with the high fat diet. Total liver RNA was isolated for real-time RT-PCR analysis. Arsenic exposure increased the expression of inflammation genes, such as TNF-α, IL-6, iNOS, chemokines, and macrophage inflammatory protein-2. The expression of the stress-related gene heme oxygenase-1 was increased, while metallothionein-1 and GSH S-transferase-pi were decreased when arsenic was combined with the high fat diet. Expression of genes related to liver fibrosis, such as procollagen-1 and -3, SM-actin and TGF-β, were synergistically increased in the arsenic plus high fat diet group. The expression of genes encoding matrix metalloproteinases (MMP2, MMP9) and tissue inhibitors of metalloproteinases (TIMP1, TIMP2) was also enhanced, suggestive of early oncogenic events. In general, arsenite produced more pronounced effects than arsenate. In summary, chronic inorganic arsenic exposure in mice produces liver injury, and a high fat diet markedly increases arsenic-induced hepatofibrogenesis.
Antioxidants and Phase 2 Enzymes in Macrophages: Regulation by Nrf2 Signaling and Protection Against Oxidative and Electrophilic Stress
Authors: Zhu Hong , Jia Zhenquan , Zhang Li , Yamamoto Masayuki , Misra Hara P. , Trush Michael A. , Li Yunbo
Published: May 2008

Macrophages play important roles in immunity and other physiological processes. They are also target cells of various toxic agents, including oxidants and electrophiles. However, little is known regarding the molecular regulation and chemical inducibility of a spectrum of endogenous antioxidants and phase 2 enzymes in normal macrophages. Understanding the molecular pathway(s) controlling the coordinated expression of various macrophage antioxidants and phase 2 defenses is of importance for developing strategies to protect against macrophage injury induced by oxidants and electrophiles. Accordingly, this study was undertaken to determine the role of the nuclear factor E2-related factor 2 (Nrf2) in regulating both constitutive and chemoprotectant-inducible expression of various antioxidants and phase 2 enzymes in mouse macrophages. The constitutive expression of a series of antioxidants and phase 2 enzymes was significantly lower in macrophages derived from Nrf2-null (Nrf2−/−) mice than those from wild-type (Nrf2+/+) littermates. Incubation of wild-type macrophages with 3 H-1,2-dithiole-3-thione (D3T) led to significant induction of various antioxidants and phase 2 enzymes, including catalase, glutathione, glutathione peroxidase (GPx), glutathione reductase, glutathione S-transferase, and NAD(P)H:quinone oxidoreductase 1. The inducibility of the above cellular defenses except for GPx by D3T was completely abolished in Nrf2−/− macrophages. As compared with wild-type cells, Nrf2− /− macrophages were much more susceptible to cell injury induced by reactive oxygen/nitrogen species, as well as two known macrophage toxins, acrolein and cadmium. Up-regulation of the antioxidants and phase 2 enzymes by D3T in wild-type macrophages resulted in increased resistance to the above oxidant-and electrophile-induced cell injury, whereas D3T treatment of Nrf2− /− macrophages provided only marginal or no cytoprotec-tion. This study demonstrates that Nrf2 is an indispensable factor in controlling both constitutive and inducible expression of a wide spectrum of antioxidants and phase 2 enzymes in macrophages as well as the susceptibility of these cells to oxidative and electrophilic stress.
Flow structure underneath the large amplitude waves of a vertically falling film
Authors: Malamataris Nikolaos A. , Balakotaiah Vemuri
Published: May 2008

Numerical solutions of the two‐dimensional Navier‐Stokes equations for vertically falling films show that when the wave amplitude exceeds a certain magnitude, two hyperbolic points on the wall and an elliptic point in the film are generated below the minimum of the wave and travel at the wave velocity. The shear stress along the wall between the hyperbolic points becomes negative and the instantaneous flow field in the film shows roll formation with flow reversal near the wall region. As the wave amplitude increases further, these rolls expand to the free surface dividing the film into regions of up and down flows. For high Kapitza number fluids such as water, multiple regions of up‐flow and negative wall shear stress exist with their width oscillating in time. The flow field is interpreted in both stationary and moving frames of reference and in explaining transport enhancements at the wall and free surface. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Food provisioning and stone handling tradition in Japanese macaques: a comparative study of ten troops
Authors: Leca Jean‐Baptiste , Gunst Noëlle , Huffman Michael A.
Published: May 2008

By addressing the influence of food provisioning on stone handling (SH), a behavioral tradition in Japanese macaques, this study contributes to the ongoing debate in cultural primatology by asking whether human intervention influences the emergence or propagation of behavioral traditions. SH is a form of object play consisting of the manipulation of stones by performing various behavioral patterns. We tested the hypothesis that the frequency of food provisioning affects the daily performance, form, and context of occurrence of SH by influencing a troop's feeding‐related activity budget. We used a standardized observation procedure to investigate SH in ten troops of Japanese macaques. In troops provisioned several times a day, SH was more frequent, longer, and more prevalent during provisioning than nonprovisioning periods. These effects of provisioning were not significant in troops provisioned less frequently. SH was more frequently integrated with food‐related activities in troops supplied with food several times a day than in the other troops. Food provisioning may be a key factor in the innovation and transformation phases of the SH tradition in Japanese macaques. Am. J. Primatol. 70:803–813, 2008. © 2008 Wiley‐Liss, Inc.
The influence of preparation conditions on the characteristics of chitosan‐alginate dressings for skin lesions
Authors: Rodrigues Ana Paula , Saraiva Sanchez Elisabete Maria , da Costa Aline Carvalho , Moraes Ângela Maria
Published: May 2008

In this work, the preparation and characterization of membranes obtained through chitosan and alginate coacervation and designed for use as wound dressings were evaluated. The influence of different stirring rates and rates of addition of chitosan solution to alginate solution on the final characteristics of the biomaterial was analyzed in detail, aiming at a simple and easily scalable membrane production protocol. The results show that membranes with dry thickness from 66 to 80 μm, wet thickness from 106 to 633 μm, tensile strength varying from 6.86 to 31.14 MPa, elongation at break from 3.97 to 8.42%, and maximum water uptake up to 19 g of water per gram of membrane and that are able to prevent the permeation of bacteria can be obtained in a fairly reproducible way by the procedure established. The membranes prepared at flow ratio of 40 mL/h and stirring equal to 100 rpm showed a high potential for use on highly exuding wounds. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis of cationic hemicellulosic derivatives with a low degree of substitution in dimethyl sulfoxide media
Authors: Ren J. L. , Peng F. , Sun R. C. , Liu C. F. , Cao Z. N. , Luo W. , Tang J. N.
Published: May 2008

A series of water‐soluble cationic 2‐hydroxylpropyltrimethylammonium hemicellulosic derivatives with low average degrees of substitution (DS's) were prepared by the incorporation of the cationic moiety 2,3‐epoxypropyltrimethylammonium chloride (ETA) onto the backbone of hemicelluloses in the presence of NaOH as a nucleophilic catalyst in homogeneous dimethyl sulfoxide (DMSO) media. The dependence of the homogeneous reaction on the different affecting factors was investigated. The average DS was calculated from the N/C ratio in the products and from the weight gain. The degree of substitution determined by the nitrogen content (DSN) values up to 0.25 in a one‐step synthesis of the etherified hemicelluloses could be controlled by the adjustment of the amount of solvent used and the molar ratio of NaOH or ETA to the anhydromonomer units in the hemicelluloses. The structure of the cationic hemicellulosic derivatives formed was determined by Fourier transform infrared spectroscopy and further confirmed with solution‐state 13C‐NMR spectroscopy. In comparison, no significant degradation of the hemicellulosic derivatives occurred during the etherification of the polymers in the homogeneous DMSO system. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
A mechanical durability comparison of various perfluocarbon proton exchange membranes
Authors: Tang H. L. , Pan M. , Wang F.
Published: May 2008

Mechanical endurance and degradation mechanism of Nafion211 proton exchange membrane and ePTFE/PFSA composite PEMs were investigated in this article. It was found that the shrinkage stress caused by the water‐uptake is the primary source to induce the mechanical decay. The Nafion 211 is more stable when cycle‐stress is lower than 1.5 MPa, while the water‐uptake generating stress can reach to 2.23 MPa soaked in surroundings with condition of 25% RH and temperature at 25°C. The study also found that the ePTFE/PFSA composite PEMs are more durable than the Nafion membrane mostly due to the lower water‐uptake generating shrinkage stress of 0.34–0.4 MPa (25% RH@ 25°C) but not the high yield strength or breaking strength. The PFSA/ePTFE composite membranes can keep stable for more than 5000 cycles, which is about 40% higher than that of the pure Nafion membrane (about 3500 cycles.). For preparing durable proton exchange membrane, it is necessary to improve the proton exchange resin impregnation in the ePTFE matrix. Chemical bonding of the PTFE and the PSFI by modification of the PTFE matrix is also very effective to enhance the mechanical durability of the composite PEMs. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
QT Dispersion at Rest and During Adenosine Stress Myocardial Perfusion Imaging Correlation with Myocardial Jeopardy Score
Authors: Pradhan J. , Vankayala H. , Niraj A. , Kumaravelu P. , Trivedi M. , Thatai D. , Afonso L.
Published: May 2008

Background

The usefulness of QT dispersion (QTd) during adenosine myocardial perfusion imaging (MPI) to predict severity of coronary artery disease (CAD) has not been studied.

Methods

Eighty‐eight patients referred for diagnostic cardiac catheterization after abnormal MPI were included. Thirty‐four patients with no stenosis (Duke Score = 0) were included in Group 1, and 54 patients with significant CAD (Duke Score ≥ 2) formed Group 2. Resting and stress QTd and prolongation in QTd (ΔQTd) were measured and evaluated as independent predictors for severity of CAD.

Results

Resting QTd was higher in Group 2 as compared with Group 1. During peak infusion of adenosine, QTd was significantly prolonged in Group 1 but remained unchanged, or fixed, in Group 2. In addition, in patients with significant CAD, resting QTd positively correlated with the Duke Score. On multiple regression analysis; independent predictors for significant CAD (odds ratio [OR], 95% confidence interval [CI], p‐value) were resting QTd (4.9, 95% CI 1.1–21.6, < 0.05 for fourth Quartile compared with first Quartile) and ΔQTd (4.0, 1.4–11.2, < 0.01 for first and second Quartiles compared with third and fourth Quartiles).

Conclusion

In patients with abnormal stress MPI, prolonged resting QTd, and fixation of QTd during stress are independent predictors of significant CAD. In addition, resting QTd correlate with the Duke Jeopardy Score and therefore, may have independent prognostic value. Copyright © 2008 Wiley Periodicals, Inc.
The Evolution of Management of Acute Coronary Syndromes (Unstable Angina and Non‐ST Segment Elevation Myocardial Infarction): Part ll
Authors: Richard Conti C.
Published: May 2008

The first cardiac catheterization in a living human was performed in 1929 by Werner Forssmann.1 Forssmann was a young urologist in training who catheterized his right atrium from his left anticubital vein and took a picture of the catheter in the right atrium. He also showed that it was safe to exercise with a catheter in the right atrium since he had to walk to the radiology department. Copyright © 2008 Wiley Periodicals, Inc.
Adsorption of Pb(II) by sawdust and neem bark from aqueous solutions
Authors: Naiya T.K. , Bhattacharya A.K. , Das S.K.
Published: May 2008

This study reports a systematic evaluation of sawdust and neem bark as low‐cost natural adsorbent for removal of Pb(II) from aqueous solutions. Studies were carried out to investigate the effect of pH, initial metal ion concentration, adsorbent dosage level, and equilibrium contact time for the adsorption process. The optimum pH for Pb(II) adsorption was found to be 5 and equilibrium was achieved within 1 h of contact time for both adsorbents. Maximum adsorption of the metal ion was obtained at an adsorbent dosage of 7.5 g/L, which may be considered as optimum adsorbent dosage level. At optimum conditions of pH, contact time and adsorbent dosage level removal efficiency of 94.5% ± 0.3% for Pb(II) adsorption was observed for sawdust, which was found to be 86.7% ± 0.5% for neem bark. Kinetics data were best described by pseudo‐second‐order model. Diffusion studies showed that the adsorption process is based on surface adsorption as well as intraparticle diffusion for both adsorbents. The equilibrium adsorption data were fitted well with Freundlich isotherm models. The sorption energy calculated from Dubinin‐Radushkevich isotherm indicated that the adsorption process is chemical in nature. The maximum adsorption capacities (qmax) of sawdust and neem bark in terms of monolayer adsorption were compared with that reported in literature. The thermodynamic equilibrium constant and the Gibbs free energy were determined and the results indicated the spontaneous adsorption process. FTIR studies were carried out to understand the type of functional groups in sawdust and neem bark responsible for metal binding process. © 2008 American Institute of Chemical Engineers Environ Prog, 2008
Flammability ranking of foliage species by factor analysis of physical and chemical pyric properties
Authors: Shan Yanlong , Liu Naian , Shu Lifu
Published: May 2008

In this paper, factor analysis is introduced to evaluate the flammability of 55 foliage species that may be used in China for construction of the fuel break network of forest strips with lower flammability. Six pyric parameters, i.e. air dry moisture content, absolute dry moisture content, ignition point, ash content, caloric value and extractive content, are measured and used as variables for factor analysis. The covariance analysis shows that four principal factors can be extracted to reflect the flammability in different physical and chemical senses. In terms of the contributions of the four factors to the variances and the physical significance of the relevant parameters, the four factors are, respectively, termed as ‘flaming factor,’ ‘air dry factor,’ ‘ash factor’ and ‘absolute dry factor.’ The stability of the factor analysis method is examined by a different number of samples considered, and the variation degrees of the orderings indicate that the method has high reliability to measure the total flammability of foliage species. The results of the flammability evaluation are verified by comparison with the recommended tree species in the Chinese technology standard. Copyright © 2008 John Wiley & Sons, Ltd.
Additive empirical force field for hexopyranose monosaccharides
Authors: Guvench Olgun , Greene Shannon N. , Kamath Ganesh , Brady John W. , Venable Richard M. , Pastor Richard W. , Mackerell Alexander D.
Published: May 2008

We present an all‐atom additive empirical force field for the hexopyranose monosaccharide form of glucose and its diastereomers allose, altrose, galactose, gulose, idose, mannose, and talose. The model is developed to be consistent with the CHARMM all‐atom biomolecular force fields, and the same parameters are used for all diastereomers, including both the α‐ and β‐anomers of each monosaccharide. The force field is developed in a hierarchical manner and reproduces the gas‐phase and condensed‐phase properties of small‐molecule model compounds corresponding to fragments of pyranose monosaccharides. The resultant parameters are transferred to the full pyranose monosaccharides, and additional parameter development is done to achieve a complete hexopyranose monosaccharide force field. Parametrization target data include vibrational frequencies, crystal geometries, solute–water interaction energies, molecular volumes, heats of vaporization, and conformational energies, including those for over 1800 monosaccharide conformations at the MP2/cc‐pVTZ//MP2/6‐31G(d) level of theory. Although not targeted during parametrization, free energies of aqueous solvation for the model compounds compare favorably with experimental values. Also well‐reproduced are monosaccharide crystal unit cell dimensions and ring pucker, densities of concentrated aqueous glucose systems, and the thermodynamic and dynamic properties of the exocyclic torsion in dilute aqueous systems. The new parameter set expands the CHARMM additive force field to allow for simulation of heterogeneous systems that include hexopyranose monosaccharides in addition to proteins, nucleic acids, and lipids. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
Force field parameters for rotation around χ torsion axis in nucleic acids
Authors: Ode Hirotaka , Matsuo Yuri , Neya Saburo , Hoshino Tyuji
Published: May 2008

To raise the accuracy of the force field for nucleic acids, several parameters were elaborated, focusing on the rotation around χ torsion axis. The reliability of molecular dynamics (MD) simulation was significantly increased by improving the torsion parameters at C8N9C1′X (X = H1′, C2′, O4′) in A, G and those at C6N1C1′X in C, T, and U. In this work, we constructed small models representing the chemical structure of A, G, C, T, and U, and estimated energy profile for χ‐axis rotation by executing numerous quantum mechanical (QM) calculations. The parameters were derived by discrete Fourier transformation of the calculated QM data. A comparison in energy profile between molecular mechanical (MM) calculation and QM one shows that our presently derived parameters well reproduce the energy surface of QM calculation for all the above torsion terms. Furthermore, our parameters show a good performance in MD simulations of some nucleic acids. Hence, the present refinement of parameters will enable us to perform more accurate simulations for various types of nucleic acids. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
Acute cold‐ and chronic heat‐exposure upregulate hepatic leptin and muscle uncoupling protein (UCP) gene expression in broiler chickens
Authors: Dridi Sami , Temim Soraya , Derouet Michel , Tesseraud Sophie , Taouis Mohammed
Published: May 2008

Emerging evidence showed that variations in environmental temperature affect both leptin and uncoupling protein (UCP) gene expression in mammals, whereas a little is known about such interactions in birds. Thus, we conducted the present study to investigate the influence of acute (2 hours) cold (4°C) and chronic (10 days) heat (32°C) exposure on hepatic leptin and muscle UCP gene expression in 5‐wk‐old broiler chickens. Both cold‐ and heat‐exposure significantly (P<0.05 to P<0.001) upregulated hepatic leptin (by 35 and 46%, respectively) and muscle UCP mRNA levels (by 71 and 71%, respectively) compared to the thermoneutrality (22°C). This result suggests that leptin and UCP may be involved in the thermoregulation response of chickens to extreme climate (cold and hot temperatures). The upregulation of hepatic leptin gene expression was accompanied by an increase in plasma leptin levels, indicating that leptin may be regulated at transcriptional level. The increase of leptin and UCP mRNA abundance, and leptinemia we report here were not related to plasma glucose or insulin levels.

In conclusion, the exposure of broiler chickens to extreme ambient temperatures (cold and heat) increases hepatic leptin and muscle UCP gene expression. J. Exp. Zool. 309A:381–388, 2008. © 2008 Wiley‐Liss, Inc.
Morphology of the melon and its tendinous connections to the facial muscles in bottlenose dolphins (Tursiops truncatus)
Authors: Harper C.J. , McLellan W.A. , Rommel S.A. , Gay D.M. , Dillaman R.M. , Pabst D.A.
Published: May 2008

The melon is a lipid‐rich structure located in the forehead of odontocetes that functions to propagate echolocation sounds into the surrounding aquatic environment. To date, the melon's ability to guide and impedance match biosonar sounds to seawater has been attributed to its unique fatty acid composition. However, the melon is also acted upon by complex facial muscles derived from the m. maxillonasolabialis. The goal of this study was to investigate the gross morphology of the melon in bottlenose dolphins (Tursiops truncatus) and to describe how it is tendinously connected to these facial muscles. Standard gross dissection (N = 8 specimens) and serial sectioning (N = 3 specimens) techniques were used to describe the melon and to identify its connections to the surrounding muscles and blubber in three orthogonal body planes. The dolphin forehead was also thin‐sectioned in three body planes (N = 3 specimens), and polarized light was used to reveal the birefringent collagen fibers within and surrounding the melon. This study identified distinct regions of the melon that vary in shape and display locally specific muscle‐tendon morphologies. These regions include the bilaterally symmetric main body and cone and the asymmetric right and left caudal melon. This study is the first to identify that each caudal melon terminates in a lipid cup that envelopes the echolocation sound generators. Facial muscles of the melon have highly organized tendon populations that traverse the melon and insert into either the surrounding blubber, the connective tissue matrix of the nasal plug, or the connective tissue sheath surrounding the sound generators. The facial muscles and tendons also lie within multiple orthogonal body planes, which suggest that the melon is capable of complex shape change. The results of this study suggest that these muscles could function to change the frequency, beam width, and directionality of the emitted sound beam in bottlenose dolphins. The echolocation sound propagation pathway within the dolphin forehead appears to be a tunable system. J. Morphol., 2008. © 2008 Wiley‐Liss, Inc.
In vitro comparison of tension and stiffness between hamstring tendon and patella tendon grafts
Authors: Elias John J. , Rai Surya P. , Ciccone II William J.
Published: May 2008

Following anterior cruciate ligament reconstruction, grafts relax and warm from the temperature of the operating room to body temperature. The current study compared graft tension and stiffness between patella tendon and hamstring tendon grafts. Six quadruple strand hamstring tendon grafts and six patella tendon grafts were preconditioned and loaded to 105 N while at 20°C. Graft tension and stiffness were measured after 15 min, after an additional 4 h, and after increasing the temperature to 34°C. A two‐way repeated‐measures analysis of variance and a post hoc test were used to compare the measurements between the two types of graft and identify significant (p < 0.05) changes for each type of graft. Tension was significantly larger for the patella tendon grafts, although the stiffness values were not significantly different (p > 0.8). For both types of graft, tension and stiffness decreased significantly with time and the temperature increase. The lowest tension and stiffness measurements were 50 ± 11 N and 129 ± 35 N/mm, respectively, for the patella tendon grafts, compared to 18 ± 5 N and 115 ± 11 N/mm, respectively, for the hamstring tendon grafts. Both types of graft lose tension to relaxation and a temperature increase, but the tension loss is larger for hamstring tendon grafts. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1506–1511, 2008
Biomechanical in vitro evaluation of the effect of cyclic loading on the postoperative fixation stability and degradation of a biodegradable ankle plate
Authors: Väänänen Petteri , Koistinen Arto , Nurmi Janne , Lappalainen Reijo
Published: May 2008

The effect of cyclic loading on the postoperative fixation stability of a biodegradable ankle plate was tested biomechanically during 12 weeks of hydrolytic degradation. Fracture of the lateral malleolus was simulated, and the parameters of cyclic loading were chosen to represent the physiological conditions during the healing period. Additionally, the effect of cyclic loading on degradation was investigated by measuring the inherent viscosities. In Group I, the cyclic loading was conducted in four phases with gradual increases in estimated walking distance and speed during the healing period. In Group II, cyclic loading was conducted after 12 weeks. Group III was used as a control for inherent viscosity measurements. None of the specimens failed under cyclic loading. No significant differences were found between the loaded groups in any of the parameters measured. Additionally, no significant difference was found in inherent viscosities at 12 weeks. The initial fixation stability provided by the biodegradable ankle plate remains biomechanically unchanged over 12 weeks. Cyclic loading, applied either during or after 12 weeks of hydrolytic degradation, does not seem to have any clinically relevant effect on the fixation stability or the degradation properties. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1485–1488, 2008
Metabolomic studies of human lung carcinoma cell lines using in vitro1H NMR of whole cells and cellular extracts
Authors: Gottschalk M. , Ivanova G. , Collins D. M. , Eustace A. , O'Connor R. , Brougham D. F.
Published: May 2008

We report principal component analysis (PCA) of 1H NMR spectra recorded for a group of human lung carcinoma cell lines in culture and 1H NMR analysis of extracts from the same samples. The samples studied were cells of lung tumour origin with different chemotherapy drug resistance patterns. For whole cells, it was found that the statistically significant causes of spectral variation were an increase in the choline and a decrease in the methylene mobile lipid 1H resonance intensities, which correlate with our knowledge of the level of resistance displayed by the different cells. Similarly, in the 1H NMR spectra of the aqueous and lipophilic extracts, significant quantitative differences in the metabolite distributions were apparent, which are consistent with the PCA results. Copyright © 2008 John Wiley & Sons, Ltd.
Optimal stabilizing controllers for linear discrete‐time stochastic systems
Authors: Feng Jun‐e , Lam James , Xu Shengyuan , Shu Zhan
Published: May 2008

The following summarizes the corrections on the online version of the paper, which will be incorporated in the print publication.

Section 3. Spectral radius, decay rate and optimal controllers. Theorem 1: The statement ‘For system (1), ρ(MA,C)⩽β∈(0, 1) holds if and only if system (1) has decay rate β−1’ should read as ‘For system (1), if ρ(MA,C)<β∈(0, 1) holds, then system (1) has decay rate β−1. Moreover, if β−1 is a decay rate, then ρ(MA,C)<β∈(0, 1)’.

Section 3. Proof necessity. Line 20: Delete ‘(necessity)’; line 21: ‘ρ(MA,C)⩽β∈(0, 1)’ should read as ‘ρ(MA,C)<β∈(0, 1)’; line 22: ‘small arbitrarily ε0>0’ should read as ‘sufficiently small ε0<0’.

Sixth page. Line 5: ‘the necessity’ should read as ‘the first part of Theorem 1’; line 7: ‘Sufficiency: Notice’ should read as ‘For the second part, notice’; line 8: ‘decay rate β’ should read as ‘decay rate β−1’; line 11: ‘To prove sufficiency we only need’ should read as ‘We only need’.

Seventh page. Corollary 3: The statement ‘For system (5), ρ(M)⩽β∈(0, 1) holds if and only if system …’ should read as ‘For system (5), if ρ(M)<β∈(0, 1) holds, then system …’

Seventh page. Line 14, and eighth page, line 20: ‘decay rate β−1∈(0, 1)’ should read as ‘decay rate β−1’.

Seventh page. Line 17, and eighth page, line 23, ‘⩽’ should be ‘<’.