International Journal of Molecular Sciences

164 KiB

Open AccessArticle

Functional Analysis of Familial Asp67Glu and Thr1051Ser BRCA1 Mutations in Breast/Ovarian Carcinogenesis

by Malinee Pongsavee, Pimpicha Patmasiriwat and Grady F. Saunders

Int. J. Mol. Sci. 2009, 10(9), 4187-4197; https://doi.org/10.3390/ijms10094187 - 24 Sep 2009

Cited by 2 | Viewed by 11613

Estrogen is believed to be pre-initiator in the risk of breast cancer. The BRCA1 is a tumor suppressor gene associated with breast and ovarian cancer risk. This report describes functional analysis of two BRCA1 missense mutations (Asp67Glu and Thr1051Ser) observed in the familial [...] Read more.

Estrogen is believed to be pre-initiator in the risk of breast cancer. The BRCA1 is a tumor suppressor gene associated with breast and ovarian cancer risk. This report describes functional analysis of two BRCA1 missense mutations (Asp67Glu and Thr1051Ser) observed in the familial breast/ovarian cancer patients in Thailand. Levels of luciferase activity of the two mutations were relatively lower than in the wild-type BRCA1. It is indicated that mutants may fail to promote the estrogen receptor dependent functions.It is presumed that estrogen and insulin/IGF-1 regulate c-Myc and cyclin D1 during breast cancer cell proliferation. It is also likely to affect ubiquitination mechanism. Since three affected cancer families carry the Asp67Glu mutation, it is believed that this type of mutation could have some effect on breast/ovarian cancer progression. Full article

(This article belongs to the Section Biochemistry)

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Graphical abstract

162 KiB

Open AccessArticle

Implementation of a Reuse Process for Liquid Crystal Displays Using an Eccentric-Form Tool

by Pai-Shan Pa

Int. J. Mol. Sci. 2009, 10(9), 4178-4186; https://doi.org/10.3390/ijms10094178 - 24 Sep 2009

Cited by 7 | Viewed by 9668

Abstract

This study presents a new nanotechnology application involving an ITO thin-film removal reuse process using an eccentric-form negative electrode, offering a fast removal rate from the surface of liquid crystal displays (LCDs). For the precision removal process, a small amount of eccentricity of [...] Read more.

This study presents a new nanotechnology application involving an ITO thin-film removal reuse process using an eccentric-form negative electrode, offering a fast removal rate from the surface of liquid crystal displays (LCDs). For the precision removal process, a small amount of eccentricity of the negative electrode or a higher rotational speed of the negative electrode corresponds to a higher etching rate for the ITO. A higher flow velocity of the electrolyte and a higher working temperature also correspond to a higher removal rate. The average effect of the eccentricity is better than the effects of a pulsed current, while the current rating need not be prolonged by the off-time. Full article

(This article belongs to the Section Biochemistry)

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317 KiB

Open AccessArticle

Effect of Quercetin on Paraoxonase 2 Levels in RAW264.7 Macrophages and in Human Monocytes—Role of Quercetin Metabolism

by Christine Boesch-Saadatmandi, Renata Toedter Pospissil, Anne-Christin Graeser, Raffaella Canali, Inka Boomgaarden, Frank Doering, Siegfried Wolffram, Sarah Egert, Manfred James Mueller and Gerald Rimbach

Int. J. Mol. Sci. 2009, 10(9), 4168-4177; https://doi.org/10.3390/ijms10094168 - 23 Sep 2009

Cited by 57 | Viewed by 14965

Abstract

There is increasing evidence that the intracellular antioxidant enzyme paraoxonase 2 (PON2) may have a protective function in the prevention of atherogenesis. An enhancement of PON2 activity by dietary factors including flavonoids is therefore of interest. In the present study we determined the [...] Read more.

There is increasing evidence that the intracellular antioxidant enzyme paraoxonase 2 (PON2) may have a protective function in the prevention of atherogenesis. An enhancement of PON2 activity by dietary factors including flavonoids is therefore of interest. In the present study we determined the effect of quercetin on paraoxonase 2 levels in cultured murine macrophages in vitro and in overweight subjects with a high cardiovascular risk phenotype supplemented with 150 mg quercetin/day for 42 days in vivo. Supplementation of murine RAW264.7 macrophages in culture with increasing concentrations of quercetin (1, 10, 20 μmol/L) resulted in a significant increase in PON2 mRNA and protein levels, as compared to untreated controls. Unlike quercetin, its glucuronidated metabolite quercetin-3-glucuronide did not affect PON2 gene expression in cultured macrophages. However the methylated quercetin derivative isorhamnetin enhanced PON2 gene expression in RAW264.7 cells to similar extent like quercetin. Although supplementing human volunteers with quercetin was accompanied by a significant increase in plasma quercetin concentration, dietary quercetin supplementation did not change PON2 mRNA levels in human monocytes in vivo. Current data indicate that quercetin supplementation increases PON2 levels in cultured monocytes in vitro but not in human volunteers in vivo. Full article

(This article belongs to the Section Biochemistry)

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359 KiB

Open AccessArticle

Lysis of Microcystis aeruginosa with Extracts from Chinese Medicinal Herbs

by Jing-Dong Yang, Liang-Bin Hu, Wei Zhou, Yu-Fen Yin, Jian Chen and Zhi-Qi Shi

Int. J. Mol. Sci. 2009, 10(9), 4157-4167; https://doi.org/10.3390/ijms10094157 - 23 Sep 2009

Cited by 11 | Viewed by 12948

Abstract

Boiling water extracts of 66 selected Chinese medicinal herbs were screened for their anticyanobaterial activity against Microcystis aeruginosa by the soft-agar overlayer (SAO) method. Results indicated that extracts from 16 materials could inhibit the growth of this bacterial species. Among these anticyanobacterial samples, [...] Read more.

Boiling water extracts of 66 selected Chinese medicinal herbs were screened for their anticyanobaterial activity against Microcystis aeruginosa by the soft-agar overlayer (SAO) method. Results indicated that extracts from 16 materials could inhibit the growth of this bacterial species. Among these anticyanobacterial samples, eight extracts showed low minimum inhibitory concentrations (MIC), including four extracts with MICs between 1 and 6 mg/mL, and four extracts with MICs < 1 mg/mL which could be considered useful to prevent the outbreak of cyanobacteria before the appearance of cyanobacterial blooms. Further study showed that three extracts with MIC values < 1 mg/mL induced intensive chlorophyll-a lysis within 7 days at the MIC. The results suggested that highly efficient anticyanobacterial compounds must be involved in the inhibitory activities. The final results indicated these three extracts (from Malaphis chinensis, Cynips gallae-tinctoriae and Fructus mume) had the potential to be developed as algicides due to their remarkably anticyanobacterial activities. Full article

(This article belongs to the Section Biochemistry)

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Graphical abstract

927 KiB

Open AccessReview

Binding and Docking Interactions of NO, CO and O₂ in Heme Proteins as Probed by Density Functional Theory

by Vangelis Daskalakis and Constantinos Varotsis

Int. J. Mol. Sci. 2009, 10(9), 4137-4156; https://doi.org/10.3390/ijms10094137 - 22 Sep 2009

Cited by 16 | Viewed by 15243

Abstract

Dynamics and reactivity in heme proteins include direct and indirect interactions of the ligands/substrates like CO, NO and O₂ with the environment. Direct electrostatic interactions result from amino acid side chains in the inner cavities and/or metal coordination in the active site, [...] Read more.

Dynamics and reactivity in heme proteins include direct and indirect interactions of the ligands/substrates like CO, NO and O₂ with the environment. Direct electrostatic interactions result from amino acid side chains in the inner cavities and/or metal coordination in the active site, whereas indirect interactions result by ligands in the same coordination sphere. Interactions play a crucial role in stabilizing transition states in catalysis or altering ligation chemistry. We have probed, by Density Functional Theory (DFT), the perturbation degree in the stretching vibrational frequencies of CO, NO and O₂ molecules in the presence of electrostatic interactions or hydrogen bonds, under conditions simulating the inner cavities. Moreover, we have studied the vibrational characteristics of the heme bound form of the CO and NO ligands by altering the chemistry of the proximal to the heme ligand. CO, NO and O₂ molecules are highly polarizable exerting vibrational shifts up to 80, 200 and 120 cm^-1, respectively, compared to the non-interacting ligand. The importance of Density Functional Theory (DFT) methodology in the investigation of the heme-ligand-protein interactions is also addressed. Full article

(This article belongs to the Special Issue Application of Density Functional Theory)

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160 KiB

Open AccessArticle

Chromosomal Location of Traits Associated with Wheat Seedling Water and Phosphorus Use Efficiency under Different Water and Phosphorus Stresses

by Hong-Xing Cao, Zheng-Bin Zhang, Cheng-Xu Sun, Hong-Bo Shao, Wei-Yi Song and Ping Xu

Int. J. Mol. Sci. 2009, 10(9), 4116-4136; https://doi.org/10.3390/ijms10094116 - 18 Sep 2009

Cited by 17 | Viewed by 16355

Abstract

The objective of this study was to locate chromosomes for improving water and phosphorus-deficiency tolerance of wheat at the seedling stage. A set of Chinese Spring- Egyptian Red wheat substitution lines and their parent Chinese Spring (recipient) and Egyptian Red (donor) cultivars were [...] Read more.

The objective of this study was to locate chromosomes for improving water and phosphorus-deficiency tolerance of wheat at the seedling stage. A set of Chinese Spring- Egyptian Red wheat substitution lines and their parent Chinese Spring (recipient) and Egyptian Red (donor) cultivars were measured to determine the chromosomal locations of genes controlling water use efficiency (WUE) and phosphorus use efficiency (PUE) under different water and phosphorus conditions. The results underlined that chromosomes 1A, 7A, 7B, and 3A showed higher leaf water use efficiency (WUE_l = Pn/Tr; Pn = photosynthetic rate; Tr = transpiration rate) under W-P (Hoagland solution with1/2P), -W-P (Hoagland solution with 1/2P and 10% PEG). Chromosomes 7A, 3D, 2B, 3B, and 4B may carry genes for positive effects on individual plant water use efficiency (WUE_p = biomass/TWC; TWC = total water consumption) under WP (Hoagland solution), W-P and -W-P treatment. Chromosomes 7A and 7D carry genes for PUE enhancement under WP, -WP (Hoagland solution with 10% PEG) and W-P treatment. Chromosome 7A possibly has genes for controlling WUE and PUE simultaneously, which indicates that WUE and PUE may share the same genetic background. Phenotypic and genetic analysis of the investigated traits showed that photosynthetic rate (Pn) and transpiration rate (Tr), Tr and WUE_l showed significant positive and negative correlations under WP, W-P, -WP and -W-P, W-P, -WP treatments, respectively. Dry mass (DM), WUE_P, PUT (phosphorus uptake) all showed significant positive correlation under WP, W-P and -WP treatment. PUE and phosphorus uptake (PUT = P uptake per plant) showed significant negative correlation under the four treatments. The results might provide useful information for improving WUE and PUE in wheat genetics. Full article

(This article belongs to the Special Issue Biotic and Abiotic Stress)

159 KiB

Open AccessReview

Liquid Crystals in Tribology

by Francisco-José Carrión, Ginés Martínez-Nicolás, Patricia Iglesias, José Sanes and María-Dolores Bermúdez

Int. J. Mol. Sci. 2009, 10(9), 4102-4115; https://doi.org/10.3390/ijms10094102 - 18 Sep 2009

Cited by 81 | Viewed by 16442

Abstract

Two decades ago, the literature dealing with the possible applications of low molar mass liquid crystals, also called monomer liquid crystals (MLCs), only included about 50 references. Today, thousands of papers, conference reports, books or book chapters and patents refer to the study [...] Read more.

Two decades ago, the literature dealing with the possible applications of low molar mass liquid crystals, also called monomer liquid crystals (MLCs), only included about 50 references. Today, thousands of papers, conference reports, books or book chapters and patents refer to the study and applications of MLCs as lubricants and lubricant additives and efforts are made to develop new commercial applications. The development of more efficient lubricants is of paramount technological and economic relevance as it is estimated that half the energy consumption is dissipated as friction. MLCs have shown their ability to form ordered boundary layers with good load-carrying capacity and to lower the friction coefficients, wear rates and contact temperature of sliding surfaces, thus contributing to increase the components service life and to save energy. This review includes the use of MLCs in lubrication, and dispersions of MLCs in conventional polymers (PDMLCs). Finally, new lubricating system composed of MLC blends with surfactants, ionic liquids or nanophases are considered. Full article

(This article belongs to the Special Issue Liquid Crystals)

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758 KiB

Open AccessArticle

Eu-Doped BaTiO₃ Powder and Film from Sol-Gel Process with Polyvinylpyrrolidone Additive

by Margarita García-Hernández, Antonieta García-Murillo, Felipe de J. Carrillo-Romo, David Jaramillo-Vigueras, Geneviève Chadeyron, Elder De la Rosa and Damien Boyer

Int. J. Mol. Sci. 2009, 10(9), 4088-4101; https://doi.org/10.3390/ijms10094088 - 17 Sep 2009

Cited by 44 | Viewed by 17872

Abstract

Transparent BaTiO₃:Eu³⁺ films were prepared via a sol-gel method and dip-coating technique, using barium acetate, titanium butoxide, and polyvinylpyrrolidone (PVP) as modifier viscosity. BaTiO₃:Eu³⁺ films ~500 nm thick, crystallized after thermal treatment at 700 ºC. The powders [...] Read more.

Transparent BaTiO₃:Eu³⁺ films were prepared via a sol-gel method and dip-coating technique, using barium acetate, titanium butoxide, and polyvinylpyrrolidone (PVP) as modifier viscosity. BaTiO₃:Eu³⁺ films ~500 nm thick, crystallized after thermal treatment at 700 ºC. The powders revealed spherical and rod shape morphology. The optical quality of films showed a predominant band at 615 nm under 250 nm excitation. A preliminary luminescent test provided the properties of the Eu³⁺ doped BaTiO₃. Full article

(This article belongs to the Special Issue Sol-Gel Technique)

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232 KiB

Open AccessReview

Mechanisms Regulating Skin Pigmentation: The Rise and Fall of Complexion Coloration

by Jody P. Ebanks, R. Randall Wickett and Raymond E. Boissy

Int. J. Mol. Sci. 2009, 10(9), 4066-4087; https://doi.org/10.3390/ijms10094066 - 15 Sep 2009

Cited by 230 | Viewed by 32545

Abstract

Skin pigmentary abnormalities are seen as aesthetically unfavorable and have led to the development of cosmetic and therapeutic treatment modalities of varying efficacy. Hence, several putative depigmenting agents aimed at modulating skin pigmentation are currently being researched or sold in commercially available products. [...] Read more.

Skin pigmentary abnormalities are seen as aesthetically unfavorable and have led to the development of cosmetic and therapeutic treatment modalities of varying efficacy. Hence, several putative depigmenting agents aimed at modulating skin pigmentation are currently being researched or sold in commercially available products. In this review we will discuss the regulation of processes that control skin complexion coloration. This includes direct inhibition of tyrosinase and related melanogenic enzymes, regulation of melanocyte homeostasis, alteration of constitutive and facultative pigmentation and down-regulation of melanosome transfer to the keratinocytes. These various processes, in the complex mechanism of skin pigmentation, can be regulated individually or concomitantly to alter complexion coloration and thus ameliorate skin complexion diseases. Full article

(This article belongs to the Special Issue Inhibitors of Melanogenesis Related Processes: Application to Food and Cosmetic Industry)

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713 KiB

Open AccessReview

Degradability of Polymers for Implantable Biomedical Devices

by SuPing Lyu and Darrel Untereker

Int. J. Mol. Sci. 2009, 10(9), 4033-4065; https://doi.org/10.3390/ijms10094033 - 11 Sep 2009

Cited by 425 | Viewed by 20179

Abstract

Many key components of implantable medical devices are made from polymeric materials. The functions of these materials include structural support, electrical insulation, protection of other materials from the environment of the body, and biocompatibility, as well as other things such as delivery of [...] Read more.

Many key components of implantable medical devices are made from polymeric materials. The functions of these materials include structural support, electrical insulation, protection of other materials from the environment of the body, and biocompatibility, as well as other things such as delivery of a therapeutic drug. In such roles, the stability and integrity of the polymer, over what can be a very long period of time, is very important. For most of these functions, stability over time is desired, but in other cases, the opposite–the degradation and disappearance of the polymer over time is required. In either case, it is important to understand both the chemistry that can lead to the degradation of polymers as well as the kinetics that controls these reactions. Hydrolysis and oxidation are the two classes of reactions that lead to the breaking down of polymers. Both are discussed in detail in the context of the environmental factors that impact the utility of various polymers for medical device applications. Understanding the chemistry and kinetics allows prediction of stability as well as explanations for observations such as porosity and the unexpected behavior of polymeric composite materials in some situations. In the last part, physical degradation such interfacial delamination in composites is discussed. Full article

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Open AccessReview

Experimental and Computational Characterization of Biological Liquid Crystals: A Review of Single-Molecule Bioassays

by Kilho Eom, Jaemoon Yang, Jinsung Park, Gwonchan Yoon, Young Soo Sohn, Shinsuk Park, Dae Sung Yoon, Sungsoo Na and Taeyun Kwon

Int. J. Mol. Sci. 2009, 10(9), 4009-4032; https://doi.org/10.3390/ijms10094009 - 10 Sep 2009

Cited by 14 | Viewed by 13352

Abstract

Quantitative understanding of the mechanical behavior of biological liquid crystals such as proteins is essential for gaining insight into their biological functions, since some proteins perform notable mechanical functions. Recently, single-molecule experiments have allowed not only the quantitative characterization of the mechanical behavior [...] Read more.

Quantitative understanding of the mechanical behavior of biological liquid crystals such as proteins is essential for gaining insight into their biological functions, since some proteins perform notable mechanical functions. Recently, single-molecule experiments have allowed not only the quantitative characterization of the mechanical behavior of proteins such as protein unfolding mechanics, but also the exploration of the free energy landscape for protein folding. In this work, we have reviewed the current state-of-art in single-molecule bioassays that enable quantitative studies on protein unfolding mechanics and/or various molecular interactions. Specifically, single-molecule pulling experiments based on atomic force microscopy (AFM) have been overviewed. In addition, the computational simulations on single-molecule pulling experiments have been reviewed. We have also reviewed the AFM cantilever-based bioassay that provides insight into various molecular interactions. Our review highlights the AFM-based single-molecule bioassay for quantitative characterization of biological liquid crystals such as proteins. Full article

(This article belongs to the Special Issue Liquid Crystals)

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Open AccessReview

The Influence of Disorder on Thermotropic Nematic Liquid Crystals Phase Behavior

by Vlad Popa-Nita, Ivan Gerlič and Samo Kralj

Int. J. Mol. Sci. 2009, 10(9), 3971-4008; https://doi.org/10.3390/ijms10093971 - 10 Sep 2009

Cited by 23 | Viewed by 13532

Abstract

We review the theoretical research on the influence of disorder on structure and phase behavior of condensed matter system exhibiting continuous symmetry breaking focusing on liquid crystal phase transitions. We discuss the main properties of liquid crystals as adequate systems in which several [...] Read more.

We review the theoretical research on the influence of disorder on structure and phase behavior of condensed matter system exhibiting continuous symmetry breaking focusing on liquid crystal phase transitions. We discuss the main properties of liquid crystals as adequate systems in which several open questions with respect to the impact of disorder on universal phase and structural behavior could be explored. Main advantages of liquid crystalline materials and different experimental realizations of random field-type disorder imposed on liquid crystal phases are described. Full article

(This article belongs to the Special Issue Liquid Crystals)

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Open AccessReview

Host Defense Peptides as Effector Molecules of the Innate Immune Response: A Sledgehammer for Drug Resistance?

by Lars Steinstraesser, Ursula M. Kraneburg, Tobias Hirsch, Marco Kesting, Hans-Ulrich Steinau, Frank Jacobsen and Sammy Al-Benna

Int. J. Mol. Sci. 2009, 10(9), 3951-3970; https://doi.org/10.3390/ijms10093951 - 9 Sep 2009

Cited by 78 | Viewed by 15179

Abstract

Host defense peptides can modulate the innate immune response and boost infection-resolving immunity, while dampening potentially harmful pro-inflammatory (septic) responses. Both antimicrobial and/or immunomodulatory activities are an integral part of the process of innate immunity, which itself has many of the hallmarks of [...] Read more.

Host defense peptides can modulate the innate immune response and boost infection-resolving immunity, while dampening potentially harmful pro-inflammatory (septic) responses. Both antimicrobial and/or immunomodulatory activities are an integral part of the process of innate immunity, which itself has many of the hallmarks of successful anti-infective therapies, namely rapid action and broad-spectrum antimicrobial activities. This gives these peptides the potential to become an entirely new therapeutic approach against bacterial infections. This review details the role and activities of these peptides, and examines their applicability as development candidates for use against bacterial infections. Full article

(This article belongs to the Special Issue Antimicrobial Agents)

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Open AccessArticle

Sage Tea Drinking Improves Lipid Profile and Antioxidant Defences in Humans

by Carla M. Sá, Alice A. Ramos, Marisa F. Azevedo, Cristovao F. Lima, Manuel Fernandes-Ferreira and Cristina Pereira-Wilson

Int. J. Mol. Sci. 2009, 10(9), 3937-3950; https://doi.org/10.3390/ijms10093937 - 9 Sep 2009

Cited by 71 | Viewed by 20888

Abstract

Salvia officinalis (common sage) is a plant with antidiabetic properties. A pilot trial (non-randomized crossover trial) with six healthy female volunteers (aged 40-50) was designed to evaluate the beneficial properties of sage tea consumption on blood glucose regulation, lipid profile and transaminase activity [...] Read more.

Salvia officinalis (common sage) is a plant with antidiabetic properties. A pilot trial (non-randomized crossover trial) with six healthy female volunteers (aged 40-50) was designed to evaluate the beneficial properties of sage tea consumption on blood glucose regulation, lipid profile and transaminase activity in humans. Effects of sage consumption on erythrocytes’ SOD and CAT activities and on Hsp70 expression in lymphocytes were also evaluated. Four weeks sage tea treatment had no effects on plasma glucose. An improvement in lipid profile was observed with lower plasma LDL cholesterol and total cholesterol levels as well as higher plasma HDL cholesterol levels during and two weeks after treatment. Sage tea also increased lymphocyte Hsp70 expression and erythrocyte SOD and CAT activities. No hepatotoxic effects or other adverse effects were observed. Full article

(This article belongs to the Special Issue Natural Compounds for the Treatment and Prevention of Metabolic Diseases)

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Open AccessCommunication

Molecule Non-Radiative Coupling to a Metallic Nanosphere: An Optical Theorem Treatment

by Gérard Colas Des Francs

Int. J. Mol. Sci. 2009, 10(9), 3931-3936; https://doi.org/10.3390/ijms10093931 - 8 Sep 2009

Cited by 9 | Viewed by 9497

Abstract

The non-radiative coupling of a molecule to a metallic spherical particle is approximated by a sum involving particle quasistatic polarizabilities. We demonstrate that energy transfer from molecule to particle satisfies the optical theorem if size effects corrections are properly introduced into the quasistatic [...] Read more.

The non-radiative coupling of a molecule to a metallic spherical particle is approximated by a sum involving particle quasistatic polarizabilities. We demonstrate that energy transfer from molecule to particle satisfies the optical theorem if size effects corrections are properly introduced into the quasistatic polarizabilities. We hope that this simplified model gives valuable information on the coupling mechanism between molecule and metallic nanostructures available for, e.g., surface enhanced spectroscopy signal analysis. Full article

(This article belongs to the Special Issue Single Molecules)

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Graphical abstract

469 KiB

Open AccessArticle

A Proline-Based Neuraminidase Inhibitor: DFT Studies on the Zwitterion Conformation, Stability and Formation

by Zhi-Wei Yang, Xiao-Min Wu, Li-Jun Zhou and Gang Yang

Int. J. Mol. Sci. 2009, 10(9), 3918-3930; https://doi.org/10.3390/ijms10093918 - 7 Sep 2009

Cited by 12 | Viewed by 14816

Abstract

The designs of potent neuraminidase (NA) inhibitors are an efficient way to deal with the recent “2009 H1N1” influenza epidemic. In this work, density functional calculations were employed to study the conformation, stability and formation of the zwitterions of 5-[(1R,2S [...] Read more.

The designs of potent neuraminidase (NA) inhibitors are an efficient way to deal with the recent “2009 H1N1” influenza epidemic. In this work, density functional calculations were employed to study the conformation, stability and formation of the zwitterions of 5-[(1R,2S)-1-(acetylamino)-2-methoxy-2-methylpentyl]-4-[(1Z)-1-propenyl]-(4S,5R)-D-proline (BL), a proline-based NA inhibitor. Compared to proline, the zwitterion stability of BL is enhanced by 1.76 kcal mol^-1 due to the introduction of functional groups. However, the zwitterion of BL will not represent a local minimum on the potential energy surface until the number of water molecules increases up to two (n = 2). With the addition of two and three water molecules, the energy differences between the zwitterions and corresponding canonical isomers were calculated at 3.13 and -1.54 kcal mol^-1, respectively. The zwitterions of BL are mainly stabilized by the H-bonds with the water molecules, especially in the case of three water molecules where the carboxyl-O atoms are largely coordination-saturated by three H-bonds of medium strengths, causing the zwitterion stability even superior to the canonical isomer. With the presence of two and three water molecules, the energy barriers for the conversion processes from the canonical isomers to the zwitterions are equal to 4.96 and 3.13 kcal mol^-1, respectively. It indicated that the zwitterion formation is facile to take place with addition of two molecules and further facilitated by more water molecules. Besides, the zwitterion formation of BL is finished in a single step, different from other NA inhibitors. Owing to the above advantages, BL is a good NA inhibitor candidate and more attention should be paid to explorations of BL-based drugs. Full article

(This article belongs to the Special Issue Applications of Density Functional Theory)

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Open AccessArticle

Expression of CD40 and CD40L in Gastric Cancer Tissue and Its Clinical Significance

by Rui Li, Wei-Chang Chen, Xue-Qin Pang, Chen Hua, Ling Li and Xue-Guang Zhang

Int. J. Mol. Sci. 2009, 10(9), 3900-3917; https://doi.org/10.3390/ijms10093900 - 4 Sep 2009

Cited by 31 | Viewed by 12014

Abstract

To study expression of CD40 and CD40L in gastric cancer tissue we assessed gastric cancer patients admitted to the Department of Gastroenterology of The First Affiliated Hospital of Soochow University and control subjects. Gastric cancer and normal (from around tumours) tissue samples were [...] Read more.

To study expression of CD40 and CD40L in gastric cancer tissue we assessed gastric cancer patients admitted to the Department of Gastroenterology of The First Affiliated Hospital of Soochow University and control subjects. Gastric cancer and normal (from around tumours) tissue samples were obtained from patients. Venous blood samples (gastric cancer and ulcer groups) were drawn on the morning of the day before surgery for the measurement of peripheral sCD40L. The expression of CD40 in gastric carcinoma specimens was examined immuno-histochemically. The clinicopathological factors, including age, sex, tumor size, gross appearance, degree of cellular differentiation, histological classification, depth of tumor invasion, lymph node metastasis, peritoneal dissemination, and TNM stage were analyzed according to the different expression of CD40. The results indicated a high CD40 expression in gastric cancer tissues. This positive expression of CD40 revealed a significant (P < 0.05) correlation with lymphatic metastasis and tumor TNM stage in gastric cancer patients. It is concluded that higher CD40 expression existed in expanding type tumors and could play an important role in clinical diagnosis of gastric cancer patients. Full article

(This article belongs to the Section Biochemistry)

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Open AccessReview

Molecular Toxicology of Substances Released from Resin–Based Dental Restorative Materials

by Athina Bakopoulou, Triantafillos Papadopoulos and Pavlos Garefis

Int. J. Mol. Sci. 2009, 10(9), 3861-3899; https://doi.org/10.3390/ijms10093861 - 4 Sep 2009

Cited by 175 | Viewed by 18822

Abstract

Resin-based dental restorative materials are extensively used today in dentistry. However, significant concerns still remain regarding their biocompatibility. For this reason, significant scientific effort has been focused on the determination of the molecular toxicology of substances released by these biomaterials, using several tools [...] Read more.

Resin-based dental restorative materials are extensively used today in dentistry. However, significant concerns still remain regarding their biocompatibility. For this reason, significant scientific effort has been focused on the determination of the molecular toxicology of substances released by these biomaterials, using several tools for risk assessment, including exposure assessment, hazard identification and dose-response analysis. These studies have shown that substances released by these materials can cause significant cytotoxic and genotoxic effects, leading to irreversible disturbance of basic cellular functions. The aim of this article is to review current knowledge related to dental composites’ molecular toxicology and to give implications for possible improvements concerning their biocompatibility. Full article

(This article belongs to the Special Issue Biocompatibility of Materials)

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Open AccessReview

Reticulate Evolution and Marine Organisms: The Final Frontier?

by Michael L. Arnold and Nicole D. Fogarty

Int. J. Mol. Sci. 2009, 10(9), 3836-3860; https://doi.org/10.3390/ijms10093836 - 3 Sep 2009

Cited by 45 | Viewed by 15870

Abstract

The role that reticulate evolution (i.e., via lateral transfer, viral recombination and/or introgressive hybridization) has played in the origin and adaptation of individual taxa and even entire clades continues to be tested for all domains of life. Though falsified for some [...] Read more.

The role that reticulate evolution (i.e., via lateral transfer, viral recombination and/or introgressive hybridization) has played in the origin and adaptation of individual taxa and even entire clades continues to be tested for all domains of life. Though falsified for some groups, the hypothesis of divergence in the face of gene flow is becoming accepted as a major facilitator of evolutionary change for many microorganisms, plants and animals. Yet, the effect of reticulate evolutionary change in certain assemblages has been doubted, either due to an actual dearth of genetic exchange among the lineages belonging to these clades or because of a lack of appropriate data to test alternative hypotheses. Marine organisms represent such an assemblage. In the past half-century, some evolutionary biologists interested in the origin and trajectory of marine organisms, particularly animals, have posited that horizontal transfer, introgression and hybrid speciation have been rare. In this review, we provide examples of such genetic exchange that have come to light largely as a result of analyses of molecular markers. Comparisons among these markers and between these loci and morphological characters have provided numerous examples of marine microorganisms, plants and animals that possess the signature of mosaic genomes. Full article

(This article belongs to the Special Issue Cladistic Analysis and Molecular Evolution)

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Open AccessArticle

Anaerobic Biodegradation Tests of Poly(lactic acid) under Mesophilic and Thermophilic Conditions Using a New Evaluation System for Methane Fermentation in Anaerobic Sludge

by Hisaaki Yagi, Fumi Ninomiya, Masahiro Funabashi and Masao Kunioka

Int. J. Mol. Sci. 2009, 10(9), 3824-3835; https://doi.org/10.3390/ijms10093824 - 2 Sep 2009

Cited by 84 | Viewed by 17232

Abstract

Anaerobic biodegradation tests of poly(lactic acid) (PLA) powder were done at the thermophilic (55 °C) and mesophilic temperature (35 °C) under aquatic conditions [total solid concentrations of the used sludge were 2.07% (at 55 °C) and 2.24% (at 35 °C)] using a newly [...] Read more.

Anaerobic biodegradation tests of poly(lactic acid) (PLA) powder were done at the thermophilic (55 °C) and mesophilic temperature (35 °C) under aquatic conditions [total solid concentrations of the used sludge were 2.07% (at 55 °C) and 2.24% (at 35 °C)] using a newly developed evaluation system. With this system, the evolved biogas is collected in a gas sampling bag at atmospheric pressure. This method is more convenient than using a pressure transducer or inverted graduated cylinder submerged in water. PLA was degraded about 60% in 30 days, about 80% in 40 days and about 90% in 60 days at 55 °C. On the other hand, the PLA degradation started in 55 days at 35 °C and degradation rate was much slower than at 55 °C. Full article

(This article belongs to the Special Issue Biodegradability of Materials)

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155 KiB

Open AccessArticle

Variations in IC₅₀ Values with Purity of Mushroom Tyrosinase

by Elizabeth Neeley, George Fritch, Autumn Fuller, Jordan Wolfe, Jessica Wright and William Flurkey

Int. J. Mol. Sci. 2009, 10(9), 3811-3823; https://doi.org/10.3390/ijms10093811 - 2 Sep 2009

Cited by 56 | Viewed by 13732

Abstract

The effects of various inhibitors on crude, commercial and partially purified commercial mushroom tyrosinase were examined by comparing IC₅₀ values. Kojic acid, salicylhydroxamic acid, tropolone, methimazole, and ammonium tetrathiomolybdate had relatively similar IC₅₀ values for the crude, commercial and partially purified [...] Read more.

The effects of various inhibitors on crude, commercial and partially purified commercial mushroom tyrosinase were examined by comparing IC₅₀ values. Kojic acid, salicylhydroxamic acid, tropolone, methimazole, and ammonium tetrathiomolybdate had relatively similar IC₅₀ values for the crude, commercial and partially purified enzyme. 4-Hexylresorcinol seemed to have a somewhat higher IC₅₀ value using crude extracts, compared to commercial or purified tyrosinase. Some inhibitors (NaCl, esculetin, biphenol, phloridzin) showed variations in IC₅₀ values between the enzyme samples. In contrast, hydroquinone, lysozyme, Zn²⁺, and anisaldehyde showed little or no inhibition in concentration ranges reported to be effective inhibitors. Organic solvents (DMSO and ethanol) had IC₅₀ values that were similar for some of the tyrosinase samples. Depending of the source of tyrosinase and choice of inhibitor, variations in IC₅₀ values were observed. Full article

(This article belongs to the Special Issue Inhibitors of Melanogenesis Related Processes: Application to Food and Cosmetic Industry)

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Trehalose Metabolism: From Osmoprotection to Signaling

by Gabriel Iturriaga, Ramón Suárez and Barbara Nova-Franco

Int. J. Mol. Sci. 2009, 10(9), 3793-3810; https://doi.org/10.3390/ijms10093793 - 1 Sep 2009

Cited by 277 | Viewed by 25393

Abstract

Trehalose is a non-reducing disaccharide formed by two glucose molecules. It is widely distributed in Nature and has been isolated from certain species of bacteria, fungi, invertebrates and plants, which are capable of surviving in a dehydrated state for months or years and [...] Read more.

Trehalose is a non-reducing disaccharide formed by two glucose molecules. It is widely distributed in Nature and has been isolated from certain species of bacteria, fungi, invertebrates and plants, which are capable of surviving in a dehydrated state for months or years and subsequently being revived after a few hours of being in contact with water. This disaccharide has many biotechnological applications, as its physicochemical properties allow it to be used to preserve foods, enzymes, vaccines, cells etc., in a dehydrated state at room temperature. One of the most striking findings a decade ago was the discovery of the genes involved in trehalose biosynthesis, present in a great number of organisms that do not accumulate trehalose to significant levels. In plants, this disaccharide has diverse functions and plays an essential role in various stages of development, for example in the formation of the embryo and in flowering. Trehalose also appears to be involved in the regulation of carbon metabolism and photosynthesis. Recently it has been discovered that this sugar plays an important role in plant-microorganism interactions. Full article

(This article belongs to the Special Issue Biotic and Abiotic Stress)

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The Reversal of Drug-Resistance in Tumors Using a Drug-Carrying Nanoparticular System

by Kyung Taek Oh, Hye Jung Baik, A Hyeong Lee, Young Taik Oh, Yu Seok Youn and Eun Seong Lee

Int. J. Mol. Sci. 2009, 10(9), 3776-3792; https://doi.org/10.3390/ijms10093776 - 31 Aug 2009

Cited by 36 | Viewed by 17167

Abstract

Medical applications of nanoparticular systems have attracted considerable attention because of their potential use in therapeutic targeting of disease tissues and their lower level of toxicity against healthy tissue, relative to traditional pharmaceutical drugs. The use of nanoparticular systems has been shown to [...] Read more.

Medical applications of nanoparticular systems have attracted considerable attention because of their potential use in therapeutic targeting of disease tissues and their lower level of toxicity against healthy tissue, relative to traditional pharmaceutical drugs. The use of nanoparticular systems has been shown to overcome the limitations of most anticancer drugs in clinical applications. In particular, the improved performance of smarted nanoparticular system for solving the drug resistance problems that typically interrupt tumor treatment has provided a promising strategy for successful tumor chemotherapy. This review highlights recent studies that have examined the therapeutic effect of nanoparticular systems on drug-resistant tumors and presents insight on how they work. Full article

(This article belongs to the Section Biochemistry)

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The Improvement of Hypertension by Probiotics: Effects on Cholesterol, Diabetes, Renin, and Phytoestrogens

by Huey-Shi Lye, Chiu-Yin Kuan, Joo-Ann Ewe, Wai-Yee Fung and Min-Tze Liong

Int. J. Mol. Sci. 2009, 10(9), 3755-3775; https://doi.org/10.3390/ijms10093755 - 27 Aug 2009

Cited by 212 | Viewed by 36036

Abstract

Probiotics are live organisms that are primarily used to improve gastrointestinal disorders such as diarrhea, irritable bowel syndrome, constipation, lactose intolerance, and to inhibit the excessive proliferation of pathogenic intestinal bacteria. However, recent studies have suggested that probiotics could have beneficial effects beyond [...] Read more.

Probiotics are live organisms that are primarily used to improve gastrointestinal disorders such as diarrhea, irritable bowel syndrome, constipation, lactose intolerance, and to inhibit the excessive proliferation of pathogenic intestinal bacteria. However, recent studies have suggested that probiotics could have beneficial effects beyond gastrointestinal health, as they were found to improve certain metabolic disorders such as hypertension. Hypertension is caused by various factors and the predominant causes include an increase in cholesterol levels, incidence of diabetes, inconsistent modulation of renin and imbalanced sexual hormones. This review discusses the antihypertensive roles of probiotics via the improvement and/or treatment of lipid profiles, modulation of insulin resistance and sensitivity, the modulation of renin levels and also the conversion of bioactive phytoestrogens as an alternative replacement of sexual hormones such as estrogen and progesterone. Full article

(This article belongs to the Special Issue Natural Compounds for the Treatment and Prevention of Metabolic Diseases)

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Theoretical Investigation of the NO₃ Radical Addition to Double Bonds of Limonene

by Lei Jiang, Wei Wang and Yi-Sheng Xu

Int. J. Mol. Sci. 2009, 10(9), 3743-3754; https://doi.org/10.3390/ijms10093743 - 27 Aug 2009

Cited by 13 | Viewed by 10694

Abstract

The addition reactions of NO₃ to limonene have been investigated using ab initio methods. Six different possibilities for NO₃ addition to the double bonds, which correspond to the two C–C double bonds (endocyclic or exocyclic) have been considered. The negative activation [...] Read more.

The addition reactions of NO₃ to limonene have been investigated using ab initio methods. Six different possibilities for NO₃ addition to the double bonds, which correspond to the two C–C double bonds (endocyclic or exocyclic) have been considered. The negative activation energies for the addition of NO₃ to limonene are calculated and the energies of NO₃-limonene radical adducts are found to be 14.55 to 20.17 kcal mol^-1 more stable than the separated NO₃ and limonene at the CCSD(T)/6-31G(d) + CF level. The results also indicate that the endocyclic addition reaction is more energetically favorable than the exocyclic one. Full article

(This article belongs to the Section Physical Chemistry, Theoretical and Computational Chemistry)

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Biodegradability of Plastics

by Yutaka Tokiwa, Buenaventurada P. Calabia, Charles U. Ugwu and Seiichi Aiba

Int. J. Mol. Sci. 2009, 10(9), 3722-3742; https://doi.org/10.3390/ijms10093722 - 26 Aug 2009

Cited by 1268 | Viewed by 83094

Abstract

Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be [...] Read more.

Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed. Full article

(This article belongs to the Special Issue Biodegradability of Materials)

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Antioxidant and Cytotoxic Activities of Centella asiatica (L) Urb.

by Frederico Pittella, Rafael C. Dutra, Dalton D. Junior, Miriam T. P. Lopes and Nádia R. Barbosa

Int. J. Mol. Sci. 2009, 10(9), 3713-3721; https://doi.org/10.3390/ijms10093713 - 26 Aug 2009

Cited by 188 | Viewed by 22409

Abstract

In the present study, the phenolic (Folin-Dennis) and flavonoid (colorimetric assay) constituents, antioxidant [2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) assay] and cytotoxic activities of an aqueous extract (AE) of Centella asiatica leaves were investigated. The aqueous extract (50 g/L) was obtained by infusion followed by cold [...] Read more.

In the present study, the phenolic (Folin-Dennis) and flavonoid (colorimetric assay) constituents, antioxidant [2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) assay] and cytotoxic activities of an aqueous extract (AE) of Centella asiatica leaves were investigated. The aqueous extract (50 g/L) was obtained by infusion followed by cold maceration for 24 h. The levels of phenolic and flavonoid compounds were 2.86 g/100 g and 0.361 g/100 g, respectively. The AE showed elevated DPPH scavenging activity, with an IC₅₀ value of 31.25 μg/mL. The AE had a promising activity against mouse melanoma (B₁₆F₁), human breast cancer (MDA MB-231) and rat glioma (C₆) cell lines, with IC₅₀ values of 698.0, 648.0 and 1000.0 μg/mL, respectively. A positive correlation was established between the level of flavonoids, antioxidant and antitumor activities. Full article

(This article belongs to the Section Biochemistry)

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Chemical Interactions and Their Role in the Microphase Separation of Block Copolymer Thin Films

by Richard A. Farrell, Thomas G. Fitzgerald, Dipu Borah, Justin D. Holmes and Michael A. Morris

Int. J. Mol. Sci. 2009, 10(9), 3671-3712; https://doi.org/10.3390/ijms10093671 - 25 Aug 2009

Cited by 91 | Viewed by 19010

Abstract

The thermodynamics of self-assembling systems are discussed in terms of the chemical interactions and the intermolecular forces between species. It is clear that there are both theoretical and practical limitations on the dimensions and the structural regularity of these systems. These considerations are [...] Read more.

The thermodynamics of self-assembling systems are discussed in terms of the chemical interactions and the intermolecular forces between species. It is clear that there are both theoretical and practical limitations on the dimensions and the structural regularity of these systems. These considerations are made with reference to the microphase separation that occurs in block copolymer (BCP) systems. BCP systems self-assemble via a thermodynamic driven process where chemical dis-affinity between the blocks driving them part is balanced by a restorative force deriving from the chemical bond between the blocks. These systems are attracting much interest because of their possible role in nanoelectronic fabrication. This form of self-assembly can obtain highly regular nanopatterns in certain circumstances where the orientation and alignment of chemically distinct blocks can be guided through molecular interactions between the polymer and the surrounding interfaces. However, for this to be possible, great care must be taken to properly engineer the interactions between the surfaces and the polymer blocks. The optimum methods of structure directing are chemical pre-patterning (defining regions on the substrate of different chemistry) and graphoepitaxy (topographical alignment) but both centre on generating alignment through favourable chemical interactions. As in all self-assembling systems, the problems of defect formation must be considered and the origin of defects in these systems is explored. It is argued that in these nanostructures equilibrium defects are relatively few and largely originate from kinetic effects arising during film growth. Many defects also arise from the confinement of the systems when they are ‘directed’ by topography. The potential applications of these materials in electronics are discussed. Full article

(This article belongs to the Special Issue The Chemical Bond and Bonding)

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Int. J. Mol. Sci., Volume 10, Issue 9 (September 2009) – 28 articles , Pages 3671-4197

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