bluuebunny/crossref_metadata_2025 huggingface dataset:
Purification and physicochemical characterization of two galactose‐specific isolectins from the seeds of Trichosanthes cordata
Authors: Sultan Nabil Ali Mohammed , Kavitha M. , Swamy Musti J.
Published: March 2009

A galactose‐specific lectin has been purified from the seeds of Trichosanthes cordata by affinity chromatography on crosslinked guar gum. The affinity‐eluted lectin could be resolved into two isolectins, TCA‐I and TCA‐II by ion‐exchange chromatography on DEAE cellulose. The molecular weights of the isolectins were determined as 59 and 52 kDa by SDS‐PAGE. TCA‐I is a heterodimer in which the two subunits with masses of 32 and 27 kDa, are covalently connected by disulfide bonds. TCA‐I and TCA‐II are glycoproteins with 6.2% and 6.8% covalently bound neutral sugar, respectively. CD spectroscopic studies indicate that the two isolectins are very similar in secondary structure and contain about 8 to 10% α‐helix, 37–38% β‐sheet, 20% β‐turns, and 32–33% unordered structures. These isolectins have similar carbohydrate specificities as revealed by hemagglutination‐inhibition assays. Carbohydrate specificity, subunit size and composition, and secondary structure of TCA isolectins suggest close similarity to type‐II ribosome inactivating proteins. The agglutination activity of TCA‐I was found to be highest in the pH range 7.0–8.0. The lectin activity was unaffected between 0 and 40°C, but decreased dramatically above 40°C. Association constant for the interaction of TCA‐I with lactose was determined by monitoring ligand‐induced changes in the protein intrinsic fluorescence characteristics as 7.42 × 103 M−1 at 25°C. The exposure and accessibility of the tryptophan residues of TCA‐I and the effect of ligand binding on them have been probed by quenching studies employing neutral and ionic quenchers. © 2009 IUBMB IUBMB Life, 61(4):457–469, 2009
Alpha‐tocopherol transport in the lung is affected by the apoE genotype—Studies in transgenic apoE3 and apoE4 mice
Authors: Huebbe Patricia , Jofre‐Monseny Laia , Rimbach Gerald
Published: March 2009

Apolipoprotein E (apoE) is a major constituent of lipoproteins mediating peripheral uptake of lipids including the lipid‐soluble vitamin alpha‐tocopherol (α‐toc). In a recent study, we observed significant lower α‐toc concentrations in the lung of apoE4 compared with apoE3 transgenic mice. In this study, we determined the mRNA levels of genes encoding for proteins centrally involved in the uptake, export, and degradation of vitamin E. Receptors of α‐toc uptake including scavenger receptor B1 (SR‐B1), LDL receptor (LDLrec), and LDLrec‐related protein 1 (LRP1) were lower in apoE4 when compared with apoE3 mice with statistical significance for SR‐B1 and LRP1. Lung mRNA levels of the ATP‐binding cassette A1 and the multidrug resistance transporter 1, surfactant proteins mediating the export of α‐toc, were lower in apoE4 than in apoE3 mice. In addition, the mRNA levels of cytochrome P450 3A, a microsomal enzyme family involved in the degradation of α‐toc, tended to be higher in the apoE4 when compared with the apoE3 genotype. Current data indicate that genes encoding for proteins involved in peripheral α‐toc transport and degradation are affected by the apoE genotype probably accounting for thelower α‐toc tissue concentration as observed in apoE4 mice. © 2009 IUBMB IUBMB Life, 61(4):453–456, 2009
Characterization of nitric oxide‐releasing microparticles for the mucosal delivery
Authors: Yoo Jin‐Wook , Lee Jae‐Suk , Lee Chi H.
Published: March 2009

For the treatment of female sexual arousal disorder (FSAD), we developed microparticles made of PLGA containing nitric oxide (NO) donor (DETA NONOate) to efficiently deliver NO to vaginal mucosa. The NO‐releasing microparticles were prepared by various emulsion methods. SEM and DSC studies were performed to examine the microparticles. The release studies were conducted under various conditions to optimize the loading dose in the microparticles. NO diffusivity through vaginal epithelial cells was evaluated and pharmacological activity of NO‐releasing microparticles was examined by assessment of intracellular cGMP level in vaginal cells. Through the modified double emulsion solvent evaporation method (w/o/wa), the acid labile DETA NONOate was stabilized during the fabrication process and homogenous morphology and high entrapment efficiency were achieved. DETA NONOate was protected under the acidic conditions of the vagina and NO was released from the microparticles in a controlled manner. A significant amount of NO produced from DETA NONOate penetrated through the vaginal epithelial cells. The intracellular cGMP level increased with the treatment of NO‐releasing microparticles in vaginal cells. These findings suggest that NO‐releasing microparticles could improve the vaginal blood perfusion and open up the possibilities of novel treatment of FSAD. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Silicate–apatite composite layers on external fixation rods and in vitro evaluation using fibroblast and osteoblast
Authors: Wang Xiupeng , Ito Atsuo , Sogo Yu , Li Xia , Oyane Ayako
Published: March 2009

A silicate–apatite layer was formed on commercially available anodically oxidized titanium rods using Na2SiO3‐containing supersaturated calcium phosphate solutions. With the increase in the concentration of Na2SiO3 in the supersaturated calcium phosphate solutions, the amounts of silicon that precipitated on the titanium rods increased from 0 to 0.07 ± 0.02 μg/cm2; meanwhile, the amounts of calcium and phosphorus that precipitated on the titanium rods decreased from 11.6 ± 1.6 and 5.7 ± 2.0 μg/cm2 to 2.6 ± 0.5 and 3.0 ± 1.0 μg/cm2, respectively. The present silicate–apatite composite layers, which demonstrated increased fibroblastic proliferation and osteoblastic proliferation and differentiation in vitro, are promising as coating layers on external fixation pins for decreasing the pin tract infection rate in vivo. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Chondrogenic differentiation of human mesenchymal stem cell aggregates via controlled release of TGF‐β1 from incorporated polymer microspheres
Authors: Solorio Loran D. , Fu Andrew S. , Hernández‐Irizarry Roberto , Alsberg Eben
Published: March 2009

Aggregate culture is a useful method for inducing chondrogenic differentiation of human mesenchymal stem cells (hMSC) in a three‐dimensional in vitro culture environment. Conventional aggregate culture, however, typically requires repeated growth factor supplementation during media changes, which is both expensive and time‐intensive. In addition, homogenous cell differentiation is limited by the diffusion of chondrogenic growth factor from the culture medium into the aggregate and peripheral cell consumption of the growth factor. We have engineered a technology to incorporate growth factor‐loaded polymer microspheres within hMSC aggregates themselves. Here, we report on the system's capacity to induce chondrogenesis via sustained delivery of transforming growth factor‐β1 (TGF‐β1). Cartilage formation after 3 weeks in the absence of externally supplied growth factor approached that of aggregates cultured by conventional methods. Chondrogenesis in the central region of the aggregates is enabled at TGF‐β1 levels much lower than those required by conventional culture using exogenously supplied TGF‐β1, which is likely a result of the system's ability to overcome limitations of growth factor diffusion from cell culture media surrounding the exterior of the aggregates. Importantly, the inclusion of growth factor‐releasing polymer microspheres in hMSC aggregates could enable in vivo chondrogenesis for cartilage tissue engineering applications without extensive in vitro culture. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Calcium phosphate‐DNA nanoparticle gene delivery from alginate hydrogels induces in vivo osteogenesis
Authors: Krebs Melissa D. , Salter Erin , Chen Eric , Sutter Kathleen A. , Alsberg Eben
Published: March 2009

There is a significant need for improved therapy for bone regeneration. The delivery of recombinant bone morphogenetic proteins has been approved for clinical use to promote osteogenesis, but still has limitations such as expense, degradation of the proteins in vivo and difficulties retaining protein at the site of injury. Localized gene delivery is a promising alternative therapy, as it would allow sustained expression of specific osteoinductive growth factors by cells near the damaged site. We have engineered an injectable system for localized, sustained nonviral gene delivery from alginate hydrogels containing preosteoblastic cells and calcium phosphate–DNA nanoparticles. The nanoparticles utilized in this report are stable, on the order of 100 nm, and have a high DNA incorporation efficiency (>66%). When the nanoparticles were incorporated in alginate hydrogels, sustained release of DNA was observed. Furthermore, MC3T3‐E1 preosteoblast cells exhibited the capacity to form bony tissue in as little as two and half weeks when mixed with DNA nanoparticles encoding for BMP‐2 into the alginate hydrogels and injected subcutaneously in the backs of mice. This injectable, minimally invasive gene delivery system may be efficacious in bone regeneration applications. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Control of proliferation and differentiation of osteoblasts on apatite‐coated poly(vinyl alcohol) hydrogel as an artificial articular cartilage material
Authors: Matsumura Kazuaki , Hayami Takashi , Hyon Suong‐Hyu , Tsutsumi Sadami
Published: March 2009

One of the key challenges in employing biomaterials is determining how to fix them into the surrounding tissue. To enhance the interaction with surrounding bone, amorphous hydroxyapatite (HA) was coated onto the surface of the bio‐inert poly(vinyl alcohol) hydrogel (PVA‐H), as an artificial cartilage material, by a pulsed laser deposition technique. Next we examined the binding effects of the HA thin film (300 nm thick) to the underlying bone using osteoblast proliferation and differentiation. A mouse osteoblast cell line, MC3T3E1, was cultured on the HA‐coated and noncoated PVA‐H with a water content of 33% or 53% for 3 weeks. Cell proliferation, alkaline phosphatase (ALP) activity, and levels of osteocalcin were evaluated for biocompatibility and differentiation. HA coating enhanced the cell proliferation, the ALP activity, and the levels of osteocalcin on both low and high water‐content PVA‐Hs. The cell growth rates on the PVA‐H were lower than on tissue culture dishes even after the HA coating was added; however, osteoblastic differentiation was highly promoted by the HA coating on low water content PVA‐H. These results suggested that the HA coating on the PVA‐H enhanced the affinity between the bone and the PVA‐H as an artificial cartilage material in surface replacement arthroplasty. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Biocompatibility evaluation of nano‐rod hydroxyapatite/gelatin coated with nano‐HAp as a novel scaffold using mesenchymal stem cells
Authors: Zandi Mojgan , Mirzadeh Hamid , Mayer Christian , Urch Henning , Eslaminejad Mohamadreza Baghaban , Bagheri Fatemeh , Mivehchi Houri
Published: March 2009

This study is devoted to fabricate a novel hydroxyapatite(HAp)/gelatin scaffold coated with nano‐HAp in nano‐rod configuration to evaluate its biocompatibility potential. The nano‐HAp particles are needle and rod‐like with widths ranging between 30 to 60 nm and lengths from 100 to 300 nm, respectively. Because of their higher surface area and higher reactivity, the nano‐rod particles were distributed in gelatin much better than spherical and mixed shapes particles. The compressive modulus of the nano‐HAp/gelatin scaffolds coated with nano‐HAp was comparable with the compressive modulus of a human cancellous bone. The potential performance of the fabricated scaffolds as seeding media was assayed using mesenchymal stem cells (MSCs). MTT (3‐(4,5‐dimethylthiazol‐2‐yl)‐1,5‐diphenyl tetrazulium bromide) assays were performed on days 4 and 7 and the number of the cells per scaffold was determined. On the basis of this assay, all the studied scaffolds exhibited an appropriate environment in which the loaded cells appeared to be proliferated during the cultivation periods. In all fabricated composite scaffolds, marrow‐derived MSCs appeared to occupy the scaffolds internal spaces and attach on their surfaces. According to the cell culture experiments, the incorporation of rod‐like nano‐HAp and coating of scaffolds with nano‐HAp particles enabled the prepared scaffolds to possess desirable biocompatibility, high bioactivity, and sufficient mechanical strength in comparison with noncoated HAp samples. This research suggests that the newly developed scaffold has a potential as a suitable scaffold for bone tissue engineering. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Antibacterial properties of nanostructured silver titanate thin films formed on a titanium plate
Authors: Inoue Yuko , Uota Masafumi , Torikai Toshio , Watari Takanori , Noda Iwao , Hotokebuchi Takao , Yada Mitsunori
Published: March 2009

Antibacterial activity of various surfaces against methicillin‐resistant Staphylococcus aureus (MRSA) was studied. Sodium titanate thin film with a porous network structure and sodium titanate nanotube thin film were formed on titanium surfaces through the reaction of titanium plates with NaOH solutions. Through a silver ion‐exchange treatment, Na+ ions in sodium titanate were exchanged with Ag+ ions in silver acetate solution, along with the loading of silver nanoparticles on the titanate surfaces. Results of silver ion elution tests of the thin films in fetal bovine serum solution indicate that the release period and the number of silver ions released from the silver titanate thin films can be controlled by altering the crystal structure, nanostructure, and thickness of the titanate phase. The silver ion‐exchanged titanate thin films showed high antibacterial activity against MRSA. It was also revealed that although the crystal structure of titanate itself has no large antibacterial effect, higher antibacterial activity mainly arises from the silver ions held in the interlayer spacing of the titanate. The obtained results should aid the development of more convenient and inexpensive antibacterial implants. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Effect of recombinant human transforming growth factor‐β2 dose on bone formation in rat femur titanium implant model
Authors: Sena Kotaro , Sumner Dale R. , Virdi Amarjit S.
Published: March 2009

Previously, we reported that application of 10 μg recombinant human TGF‐β2 (rhTGF‐β2) enhanced peri‐implant bone formation and bone‐implant contact in a rat model. To further investigate the dose effect, the present experiment evaluated doses of rhTGF‐β2 bracketed around 10 μg (5, 10, 20 μg) using the same model. Four groups (including buffer‐only control) received femoral implantation of hydroxyapatite/tricalcium phosphate‐coated titanium implants. Four weeks post‐surgery, all femurs were collected and analyzed by micro computed tomography followed by a mechanical test or histology. Compared with control, all rhTGF‐β2‐treated groups had significantly higher bone volume. Bone‐implant contact was not different between the control, 5, and 10 μg groups; however, the 20 μg group had less contact than the control. There were significant decreases in the strength of fixation in all rhTGF‐β2 treated groups compared with the control. In particular, while rhTGF‐β2 was able to enhance bone formation in the vicinity of the implant, the relative lack of bone‐implant contact in the 20 μg group depressed the strength of fixation, suggesting that the location as well as the amount of new bone formed is important for implant fixation. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Development of new chitosan/carrageenan nanoparticles for drug delivery applications
Authors: Grenha Ana , Gomes Manuela E. , Rodrigues Márcia , Santo Vítor E. , Mano João F. , Neves Nuno M. , Reis Rui L.
Published: March 2009

The use of polymeric nanoparticles, especially those composed of natural polymers, has become a very interesting approach in drug delivery, mainly because of the advantages offered by their small dimensions. The aim of this work was to develop a novel formulation of nanoparticles comprised of two natural marine‐derived polymers, namely chitosan and carrageenan, and to evaluate their potential for the association and controlled release of macromolecules. Nanoparticles were obtained in a hydrophilic environment, under very mild conditions, avoiding the use of organic solvents or other aggressive technologies for their preparation. The developed nanocarriers presented sizes within 350–650 nm and positive zeta potentials of 50–60 mV. Polymeric interactions between nanoparticles' components were evaluated by Fourier transform infrared spectroscopy. Using ovalbumin as model protein, nanoparticles evidenced loading capacity varying from 4% to 17% and demonstrated excellent capacity to provide a controlled release for up to 3 weeks. Furthermore, nanoparticles have demonstrated to exhibit a noncytotoxic behavior in biological in vitro tests performed using L929 fibroblasts, which is critical regarding the biocompatibility of those carriers. In summary, the developed chitosan‐carrageenan nanoparticles have shown promising properties to be used as carriers of therapeutic macromolecules, with potential application not only strictly in drug delivery, but also in broader areas, such as tissue engineering and regenerative medicine. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Human embryonic stem cell technologies and drug discovery
Authors: Jensen Janne , Hyllner Johan , Björquist Petter
Published: March 2009

Development of new drugs is costly and takes huge resources into consideration. The big pharmaceutical companies are currently facing increasing developmental costs and a lower success‐rate of bringing new compounds to the market. Therefore, it is now of outmost importance that the drug‐hunting companies minimize late attritions due to sub‐optimal pharmacokinetic properties or unexpected toxicity when entering the clinical programs. To achieve this, a strong need to test new candidate drugs in assays of high human relevance in vitro as early as possible has been identified. The traditionally used cell systems are however remarkably limited in this sense, and new improved technologies are of greatest importance. The human embryonic stem cells (hESC) is one of the most powerful cell types known. They have not only the possibility to divide indefinitely; these cells can also differentiate into all mature cell types of the human body. This makes them potentially very valuable for pharmaceutical development, spanning from use as tools in early target studies, DMPK or safety assessment, as screening models to find new chemical entities modulating adult stem cell fate, or as the direct use in cell therapies. This review illustrates the use of hESC in the drug discovery process, today, as well as in a future perspective. This will specifically be exemplified with the most important cell type for pharmaceutical development—the hepatocyte. We discuss how hESC‐derived hepatocyte‐like cells could improve this process, and how these cells should be cultured if optimized functionality and usefulness should be achieved. J. Cell. Physiol. 219: 513–519, 2009. © 2009 Wiley‐Liss, Inc.
Co‐composting an animal fatty‐proteinaceous waste with a solid lignocellulosic by‐product from the olive oil industry (‘alperujo’)
Authors: Alburquerque J. A. , Bautista‐Carrascosa I. , Lidón A. , García‐de‐la‐Fuente R. , Girbent J. , Abad M. , Cegarra J.
Published: March 2009

BACKGROUND:The production of biodegradable wastes and their disposal cause a major financial problem in many industrial activities. Co‐composting was thought to be a feasible alternative for disposing of a strongly alkaline waste from the pharmaceutical industry (AW), mainly consisting of animal fats and partially hydrolysed proteins in a stable emulsion. The AW was added gradually, during the early phase of the composting process, to a substrate made up of ‘alperujo’ (AL), the wet, lignocellulosic, solid by‐product of the olive oil industry, and fresh horse manure, which was added to improve the physical structure of the composting substrate.

RESULTS:The addition of AW reduced organic matter degradation during composting, enriched the amount of organic compounds in the water‐ and alkali‐soluble fractions and increased mineral salt contents. Thus, significantly higher electrical conductivity, humification indices and contents of organic matter, P, K and Na were recorded in the end‐composts resulting from AW treatments. However, the application of one AW‐based compost led to soil N immobilisation, as revealed by an incubation experiment, which must be considered in order to avoid potential N starvation in the short term.

CONCLUSION:According to these results, composting can be used as a disposal alternative for AW, leading to end‐products with potential uses as organic amendments or fertilisers for agricultural systems. In addition, these composts could be used to produce alternative liquid organic fertilisers, based on the extraction of their humic‐like fraction. Copyright © 2009 Society of Chemical Industry
Cadmium biosorption by Streptomyces sp. F4 isolated from former uranium mine
Authors: Siñeriz Manuel Louis , Kothe Erika , Abate Carlos Mauricio
Published: March 2009

46 actinomycetes were isolated from two polluted sites and one unpolluted site. One strain, F4, was selected through primary qualitative screening assays because of its cadmium resistance, and physiologically and taxonomically characterized. F4 was able to grow at 7.5% NaCl and 100 μg/ml lysozyme and at a pH between 6 and 10. 16S rDNA sequence analysis showed that F4 was closely related to Streptomyces tendae. Growth of Streptomyces sp. F4 on culture medium with 8 mg/l Cd2+ for 8 days showed 80% inhibition. Maximum specific biosorption was 41.7 mg Cd2+/g dry weight after 7 days of growth and highest Cd2+ concentration was found in the cell wall (41.2%). The exopolysaccharide layer only contained 7.4%, whereas 39.4% of Cd2+ was found in the cytosolic fraction. Twelve % was found in the ribosomes and membrane fraction. This was verified with TEM, showing Streptomyces sp. F4 cytoplasm with dark granulate appearance. This study could present the potential capacity of Streptomyces sp. F4 for Cd2+ bioremediation. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Biodegradation of diisodecyl phthalate (DIDP) by Bacillus sp. SB‐007
Authors: Park Jae‐Min , Kim Mina , Yoon Jihee , Kobayashi Fumihisa , Iwasaka Yasunobu , Hong Chun‐Sang , Min Jiho , Kim Yang‐Hoon
Published: March 2009

In this study, diisodecyl phthalate (DIDP) was efficiently degraded by Bacillus sp. SB‐007. The optimal conditions for DIDP (100 mg l–1) degradation by Bacillus sp. SB‐007 in a mineral salts medium were found to be pH 7.0 at 30 °C, stirring at 200 rpm. The specific rate of DIDP degradation was found to be concentration dependent with a maximum of 4.87 mg DIDP l–1 h–1. DIDP was transformed rapidly by Bacillus sp. SB‐007 with the formation of monoisodecyl phthalate and phthalic acid, which subsequently degraded further. These results highlight the potential of this bacterium for removing DIDP contaminated waste in the environment. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Diversity and phylogeny of culturable spore‐forming Bacilli isolated from marine sediments
Authors: Ettoumi Besma , Raddadi Noura , Borin Sara , Daffonchio Daniele , Boudabous Abdellatif , Cherif Ameur
Published: March 2009

Members of the genus Bacillus and related genera are ubiquitous in nature. However, Bacillus species isolated from marine sediments have attracted less interest respect to their terrestrial relatives. Here, we report the phylogenetic diversity of a collection of 96 Bacilli, isolated from 17 distinct stations of 5 oceanographic campaigns. The diversity was analysed by phenotypic and molecular approaches based on the amplified rDNA restriction analysis (ARDRA), amplification of the internal transcribed spacers (ITS‐PCR) and on 16S rRNA sequencing. Intra‐specific polymorphism was efficiently detected by biochemical analysis and ARDRA while results of ITS‐PCR were in agreement with 16S rRNA sequencing. The identification results assigned 68% of the isolates to the species B. subtilis, B. licheniformis, B. pumilus and B. cereus. Phylogenetic analysis allowed the separation of 9 isolates in a clade that may represent a group of obligate marine Bacillus since they clustered with B. firmus, B. foraminis and marine isolates with metal oxidation and bioaccumulation capabilities. The remaining isolates showed a close affiliation to the genera Virgibacillus, Gracilibacillus and Paenibacillus. The widespread of Bacilli and their high diversity level observed in this work point out the need of more extensive studies to understand their distribution and ecology in deep‐sea environments. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Laccase production by Pycnoporus sanguineus under different culture conditions
Authors: Eugenio María Eugenia , Carbajo José María , Martín Juan Antonio , González Aldo Enrique , Villar Juan Carlos
Published: March 2009

Pycnoporus sanguineus is a white‐rot fungus that produces ligninolytic enzymes such as laccases. These enzymes can endure temperatures as high as 60 °C and are useful for pulp bleaching, dye decolorization and phenolic degradation.

Laccase production by fungi depends not only on the carbon and nitrogen sources but also on the nitrogen concentration of the culture medium. In this work, we examined the effect of four carbon sources (maltose, glucose, fructose and sucrose) and four nitrogen sources (ammonium tartrate, sodium nitrate, asparagine and yeast extract) on the activity of laccase from Pycnoporus sanguineus. All carbon and nitrogen sources exhibited a strong influence on laccase activity, a sucrose–asparagine medium providing the best results (320 mU/ml). Moreover, using an asparagine concentration 5 times higher than the reference level increased laccase activity to 820 mU/ml. Higher asparagine concentrations, however, resulted in no further increase in activity.

Consistent with previous results, the carbon and nitrogen sources, and the nitrogen concentration, had a strong impact on laccase activity, the optimum conditions depending on the particular fungus. The conditions of the culture medium had a marked effect on laccase activity, which increased up to 820 mU/ml. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Molecular diversity of a native mesorhizobial population of nodulating chickpea (Cicer arietinum L.) in Indian soils
Authors: Nandwani Rachna , Dudeja S. S.
Published: March 2009

Chickpea plants with nodules were collected from 32 different farmers' fields of eight districts of Haryana state. In total, 137 mesorhizobial isolations were made from these nodules and authenticated. Finally, 50 mesorhizobia were selected based on nodulation test, growth characteristics, and site of sampling. The molecular diversity of the mesorhizobial population was assessed by PCR‐amplified ERIC profiles as well as RFLP of 16S rDNA. Considerable molecular diversity in Haryana soils was observed. Chickpea rhizobia were grouped into six different clusters at the 70% similarity level by both methodologies, but clustering of the strains was different. Considering that each cluster represented a mesorhizobial genotype, Haryana soils showed a high richness index (0.46), and RFLP analysis showed that the mesorhizobial genotype (MG) I was present in 38% of nodules, followed by MG III which was detected in 34% of the nodules. The distribution of different MG in Haryana soils showed that all six types of rhizobia were never present in any of the districts; however, a maximum of five types were present in the Bhiwani district. Rhizobial genotype III was invariably present in all the nodule samples tested. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Improving clinical significance of PCR: Use of propidium monoazide to distinguish viable from dead staphylococcus aureus and staphylococcus epidermidis
Authors: Kobayashi Hideo , Oethinger Margret , Tuohy Marion J. , Hall Gerri S. , Bauer Thomas W.
Published: March 2009

Molecular techniques, such as the polymerase chain reaction (PCR) have high sensitivity when used to diagnose infection, but may detect DNA, RNA, and proteins from dead, as well as viable, bacteria. Propidium monoazide (PMA) is a DNA binding agent, that has the ability to penetrate only dead cells with compromised membranes and has been used in conjunction with real‐time PCR to distinguish intact from dead bacterial cells. In this study, intact, heat‐inactivated (dead), and intact/dead admixed Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis) were treated with PMA or left untreated before DNA extraction. We quantified levels of 16S rDNA and tuf gene by real‐time quantitative PCR (qPCR), to test the ability of PMA to distinguish intact from dead bacteria. Our results indicated that PMA inhibited detection of dead bacteria, and the qPCR results reflected the number of intact bacteria without being impacted by the presence of the dead bacteria. This approach of combining qPCR with and without PMA treatment has promise to limit false‐positive PCR results when used to diagnose infections, but needs to be further validated in clinical samples. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Enhanced flexor tendon healing through controlled delivery of PDGF‐BB
Authors: Thomopoulos Stavros , Das Rosalina , Silva Matthew J. , Sakiyama‐Elbert Shelly , Harwood Frederick L. , Zampiakis Emmanouil , Kim H. Mike , Amiel David , Gelberman Richard H.
Published: March 2009

A fibrin/heparin‐based delivery system was used to provide controlled delivery of platelet derived growth factor BB (PDGF‐BB) in an animal model of intrasynovial flexor tendon repair. We hypothesized that PDGF‐BB, administered in this manner, would stimulate cell proliferation and matrix remodeling, leading to improvements in the sutured tendon's functional and structural properties. Fifty‐six flexor digitorum profundus tendons were injured and repaired in 28 dogs. Three groups were compared: (1) controlled delivery of PDGF‐BB using a fibrin/heparin‐based delivery system; (2) delivery system carrier control; and (3) repair‐ only control. The operated forelimbs were treated with controlled passive motion rehabilitation. The animals were euthanized at 7, 14, and 42 days, at which time the tendons were assessed using histologic (hyaluronic acid content, cellularity, and inflammation), biochemical (total DNA and reducible collagen crosslink levels), and biomechanical (gliding and tensile properties) assays. We found that cell activity (as determined by total DNA, collagen crosslink analyses, and hyaluronic acid content) was accelerated due to PDGF‐BB at 14 days. Proximal interphalangeal joint rotation and tendon excursion (i.e., tendon gliding properties) were significantly higher for the PDGF‐BB‐treated tendons compared to the repair‐alone tendons at 42 days. Improvements in tensile properties were not achieved, possibly due to suboptimal release kinetics or other factors. In conclusion, PDGF‐BB treatment consistently improved the functional but not the structural properties of sutured intrasynovial tendons through 42 days following repair. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Kinetics of the gas‐phase reactions of chlorine atoms with CH2F2, CH3CCl3, and CF3CFH2 over the temperature range 253–553 K
Authors: Nilsson E. J. K. , Johnson M. S. , Nielsen O. J. , Kaiser E. W. , Wallington T. J.
Published: March 2009

Relative rate techniques were used to study the title reactions in 930–1200 mbar of N2 diluent. The reaction rate coefficients measured in the present work are summarized by the expressions k(Cl + CH2F2) = 1.19 × 10−17 T2 exp(−1023/T) cm3 molecule−1 s−1 (253–553 K), k(Cl + CH3CCl3) = 2.41 × 10−12 exp(−1630/T) cm3 molecule−1 s−1 (253–313 K), and k(Cl + CF3CFH2) = 1.27 × 10−12 exp(−2019/T) cm3 molecule−1 s−1 (253–313 K). Results are discussed with respect to the literature data. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 401–406, 2009
Estimation of heterogeneous rate constants of reaction of electrochemically generated o‐benzoquinones with various nucleophiles containing thiol group
Authors: Fotouhi Lida , Tammari Esmail , Asadi Samaneh , Heravi Majid M. , Nematollahi Davood
Published: March 2009

The reaction of o‐benzoquinone derived by the oxidation of catechols (1a–c) with some nucleophiles containing thiol group (2a–f) has been studied in various conditions, such as pH, nucleophile concentration, and scan rate, using cyclic voltammetry. In various conditions, based on an EC electrochemical mechanism (“E” represents an electron transfer at the electrode surface and “C” represents a homogeneous chemical reaction), the observed homogeneous rate constants (kobs) were estimated by comparison of the experimental cyclic voltammetric responses with the digital simulated results for each of the nucleophile. The results show that the magnitude of kobs is dependent on the nature of the substituted group on the catechol ring and nucleophilicity of nucleophile. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 426–431, 2009
Kinetic studies of hydrazine and 2‐hydroxyethylhydrazine alkylation by 2‐chloroethanol: Influence of a strong base in the medium
Authors: Goutelle V. , Pasquet V. , Stephan J. , Bougrine A. J. , Delalu H.
Published: March 2009

To optimize yields, the study of reaction kinetics related to the synthesis of 2‐hydroxyethylhydrazine (HEH) obtained from the alkylation of N2H4 by 2‐chloroethanol (CletOH) was carried out with and without sodium hydroxide. In both cases, the main reaction of HEH formation was followed by a consecutive, parallel reaction of HEH alkylation (or dialkylation of N2H4), leading to the formation of two isomers: 1,1‐di(hydroxyethyl)hydrazine and 1,2‐di(hydroxyethyl)hydrazine. In this study, hydrazine and hydroxyalkylhydrazine alkylations followed SN2 reactions triggered directly by CletOH or indirectly in the presence of a strong base by ethylene oxide, an intermediate compound. The kinetics was studied in diluted mediums by quantifying HEH and CletOH by gas chromatography and gas chromatography coupled with mass spectrometry (GC‐MS). The activation parameters of each reaction and the influence of a strong base present in the medium on the reaction mechanisms were established. A global mathematical treatment was applied for each alternative. It allowed modeling the reactions as a function of reagent concentrations and temperature. In the case of direct alkylation by CletOH, simulation was established for semi‐batch and batch syntheses and was confirmed in experiments for concentrated mediums (1.0 M ≤ [CletOH]0 ≤ 3.2 M and 15.7 M ≤ [N2H4]0 ≤ 18.8 M). Simulation therefore permits the prediction of the instantaneous concentration of reagents and products, in particular ethylene oxide concentration in the case of indirect alkylation, which must be as weak as possible. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 382–393, 2009
Rate constants for the gas‐phase β‐myrcene + OH and isoprene + OH reactions as a function of temperature
Authors: Hites Ronald A. , Turner Andrew M.
Published: March 2009

Rate constants for the gas‐phase reactions of the hydroxyl radical with the biogenic hydrocarbons, β‐myrcene and isoprene, were measured using the relative rate technique over the temperature range 313–413 K and at ∼1 atm total pressure. OH was produced by the photolysis of H2O2, and helium was the diluent gas. The reactants were detected by online mass spectrometry, which resulted in high time resolution allowing for large amounts of data to be collected and used in the determination of the Arrhenius parameters. Many experiments were performed over the temperature range of interest, leading to more accurate parameters than previous investigations. The following Arrhenius expression has been determined for these reactions (in units of cm3 molecule−1 s−1): for isoprene k = (3.14) × 10−11 exp [(338 ± 19)/T] and for β‐myrcene k = (9.19) × 10−12 exp[(1071 ± 82)/T]. The Arrhenius plot for the isoprene + OH reaction indicates curvature in this relationship and is given by k = (3.47 ± 0.14) × 10−17 T2 exp [(1036 ± 14)/T]. Our measured rate constant for the β‐myrcene + OH reaction at 298 K is higher, but not significantly, than current literature values. This is the first report of β‐myrcene's rate constant with OH as a function of temperature. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 407–413, 2009
Kinetics of catalytic esterification of propionic acid with different alcohols over Amberlyst 15
Authors: Ali Sami H.
Published: March 2009

The kinetics of the esterification reaction between propionic acid and methanol, ethanol, and 1‐butanol over the ion exchange resin, Amberlyst 15, was investigated. Experiments were conducted using a fixed‐bed plug flow reactor over the temperature range of 298–328 K. Acid to alcohol molar ratios of 3:1, 1:1, and 1:3 were employed. For each esterification system, the equilibrium conversion of propionic acid was found to increase with increasing reaction temperature. Several kinetic models were tested to correlate the collected data under kinetically controlled conditions; the pseudo‐homogeneous (P‐H), Eley–Rideal (E–R), Langmuir–Hinshelwood (L–H), and Pöpken (P‐P) models. In all cases, the activity coefficients were estimated using the UNIFAC model to account for the nonideal thermodynamic behavior of the reactants and products. The P‐P model was found to best represent the kinetic data of the investigated esterification systems with a total average error of less than 3%. The increase of alcohol chain length had a negative impact on the conversion of propionic acid due to steric hindrance. The activation energy of the esterification reaction is influenced by the chain length of the alcohol used. The adsorption equilibrium constants estimated by the P‐P model and the solubility parameters reported by AICHE DIPPER® followed the same trend; ester < acid < alcohol < water. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 432–448, 2009
Surface Area Effects in Hydroxyapatite/Poly(ε‐caprolactone) Nanocomposites
Authors: Kaur Jasmeet , Shofner Meisha L.
Published: March 2009

In order to understand the contribution of nanoparticle surface area to the properties of nanocomposite materials, hydroxyapatite nanoparticles with different specific surface areas (60 m2 · g−1 and 111 m2 · g−1) were synthesized using reverse microemulsion and processed into nanocomposites. Experimental results indicated that the thermomechanical reinforcement did show a dependence on nanoparticle surface area, although the transition temperatures did not. The reinforcement trends were dependent on temperature, suggesting that the nanoparticles had a greater impact on the amorphous polymer chains. The reinforcement above Tg may be plotted against nanoparticle surface area to obtain a single reinforcement trend, suggesting that surface area is a general parameter for nanocomposite property control.

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Myocardial 3D strain calculation by combining cine displacement encoding with stimulated echoes (DENSE) and cine strain encoding (SENC) imaging
Authors: Hess Aaron T. , Zhong Xiaodong , Spottiswoode Bruce S. , Epstein Frederick H. , Meintjes Ernesta M.
Published: March 2009

Three‐dimensional (3D) strain maps of the myocardium provide a coordinate‐system–independent quantification of myocardial deformation and kinematics. We combine two MRI techniques, displacement encoding with stimulated echoes (DENSE) and strain encoding (SENC), to fully formulate a 3D strain map in a single slice of myocardium. The method utilizes 2D DENSE in‐plane displacement measurements in two adjacent slices in conjunction with a single SENC through‐plane strain measure to calculate the 3D strain tensor. Six volunteers were imaged and the technique demonstrated 3D strain measures in all volunteers that are consistent with those reported in the literature from 3D tagging. The mean peak strain (± standard deviation [SD]) for six healthy volunteers for the first, second, and third principal strains are 0.42 ±0.11, –0.10 ±0.03, and –0.21 ±0.02, respectively. These results show that this technique is capable of reliably quantifying 3D cardiac strain. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Post hoc interpretation of urodynamic evaluation is qualitatively different than interpretation at the time of urodynamic study
Authors: Smith Phillip P. , Hurtado Eric A. , Appell Rodney A.
Published: March 2009

Objectives

Intraobserver reliability of post hoc urodynamic interpretation is greater than interobserver reliability, attributable to interpreter bias. If post hoc interpretation is qualitatively similar to interpretation at the time of study by a urodynamicist in attendance (“live” interpretation), a similar intraobserver bias should be observed. We therefore evaluated the intra‐ and interobserver reliability of post hoc versus “live” interpretation.

Methods

Fifty‐five consecutive urodynamic studies administered by each of two urodynamicists and interpreted at the time of study were de‐identified and later re‐interpreted by the same two physicians. History and exam findings, cystometric tracing, uroflow summary and radiographs were available for interpretation. Intraobserver (post hoc vs. live), interobserver (post hoc vs. live) and interobserver (post hoc vs. post hoc) reliability was assessed by correlation coefficients for quantitative data, and Cohen's kappa statistic for categorical data.

Results

Post hoc versus live interpretations demonstrated no superiority of intraobserver reliability. For categorical observations, intraobserver reliability was best for urodynamic observations, but worse for clinical diagnosis (κ = 0.37) and primary treatment recommendation (κ = 0.26). Interobserver reliabilities were similar to intraobserver. Post hoc/post hoc interobserver correlations for quantitative data were good to very good, r2 = 0.611–0.914.

Conclusions

In contrast to previously reported post hoc/post hoc comparisons, post hoc/live comparison demonstrated no superiority of intraobserver reliability. Urodynamic observations and impressions are more reliable than are clinical diagnosis and therapeutic recommendation based upon urodynamic evaluation. Unrecorded and heuristic observations at the time of study as well as interpreter judgment may thus be determinants of diagnostic interpretation of urodynamic evaluation. Neurourol. Urodynam. 28:998–1002, 2009. © 2009 Wiley‐Liss, Inc.
A metabonomic approach to early prognostic evaluation of experimental sepsis by 1H NMR and pattern recognition
Authors: Lin Zhong‐ying , Xu Ping‐bo , Yan Shi‐kai , Meng Hai‐bing , Yang Gen‐jin , Dai Wei‐xing , Liu Xin‐ru , Li Jin‐bao , Deng Xiao‐ming , Zhang Wei‐dong
Published: March 2009

This study proposes an NMR‐based metabonomic approach to early prognostic evaluation of sepsis. Forty septic rats receiving cecal ligation and puncture (CLP) were divided into the surviving group and nonsurviving group on day 6, while 20 sham‐operated rats served as the control group. Serum samples were collected from septic and sham‐operated rats at 12 h after surgery and analyzed using 1H NMR spectroscopy. Orthogonal partial least squares (OPLS) were applied and showed clustering according to predefined groups, indicating that NMR‐based metabolic profiling could reveal pathologic characteristics in the serum of sham‐operated, surviving, and nonsurviving septic rats. In addition, six characteristic metabolites including lactate, alanine, acetate, acetoacetate, hydroxybutyrate, and formate, which are mainly involved in energy metabolism, changed markedly in septic rats, especially in the nonsurvivors. Using these metabolites, a predictive model for prognostic evaluation of sepsis was constructed using a radial basis function neural network (RBFNN) with a prediction accuracy of about 87% by test samples. The results indicated that the NMR‐based metabonomic approach is a potential technique for the early prognostic evaluation of sepsis. Copyright © 2009 John Wiley & Sons, Ltd.
1H HR‐MAS and genomic analysis of human tumor biopsies discriminate between high and low grade astrocytomas
Authors: Righi Valeria , Roda Jose M. , Paz José , Mucci Adele , Tugnoli Vitaliano , Rodriguez‐Tarduchy Gemma , Barrios Laura , Schenetti Luisa , Cerdán Sebastián , García‐Martín María L.
Published: March 2009

We investigate the profile of choline metabolites and the expression of the genes of the Kennedy pathway in biopsies of human gliomas (n = 23) using1H High Resolution Magic Angle Spinning (HR‐MAS, 11.7 Tesla, 277 K, 4000 Hz) and individual genetic assays.1H HR‐MAS spectra allowed the resolution and relative quantification by the LCModel of the resonances from choline (Cho), phosphocholine (PC) and glycerophosphorylcholine (GPC), the three main components of the combined tCho peak observed in gliomas byin vivo1H NMR spectroscopy. All glioma biopsies depicted a prominent tCho peak. However, the relative contributions of Cho, PC, and GPC to tCho were different for low and high grade gliomas. Whereas GPC is the main component in low grade gliomas, the high grade gliomas show a dominant contribution of PC. This circumstance allowed the discrimination of high and low grade gliomas by1H HR‐MAS, a result that could not be obtained using the tCho/Cr ratio commonly used byin vivo1H NMR spectroscopy. The expression of the genes involved in choline metabolism has been investigated in the same biopsies. High grade gliomas depict an upregulation of the β gene of choline kinase and phospholipase C, as well as a downregulation of the cytidyltransferase B gene, the balance of these being consistent with the accumulation of PC. In the low grade gliomas, phospholipase A1and lysophospholypase are upregulated and phospholipase D is downregulated, supporting the accumulation of GPC. The present findings offer a promising procedure that will potentially help to accurately grade glioma tumors using1H HR‐MAS, providing in addition the genetic background for the alterations of choline metabolism observed in high and low grade gliomas. Copyright © 2009 John Wiley & Sons, Ltd.
Multislice multiecho T2* cardiac magnetic resonance for the detection of heterogeneous myocardial iron distribution in thalassaemia patients
Authors: Positano Vincenzo , Pepe Alessia , Santarelli Maria Filomena , Ramazzotti Anna , Meloni Antonella , De Marchi Daniele , Favilli Brunella , Cracolici Eliana , Midiri Massimo , Spasiano Anna , Lombardi Massimo , Landini Luigi
Published: March 2009

The present study investigated myocardial T2* heterogeneity in thalassaemia major (TM) patients by cardiac magnetic resonance (CMR), to determine whether is related to inhomogeneous iron overload distribution. A total of 230 TM patients consecutively referred to our laboratory were studied retrospectively. Three short‐axis views (basal, medium and apical) of the left ventricle (LV) were obtained by multislice multiecho T2* CMR. T2* segmental distribution was mapped on a 16‐segment LV model. The level of heterogeneity of the T2* segmental distribution, evaluated by the coefficient of variation (CoV), was compared with that of a surrogate data set, to determine whether the inhomogeneous segmental distribution of T2* could be generated by susceptibility artefacts. Susceptibility artefacts offer an explanation for the T2* heterogeneity observed in patients without iron overload. In subjects with global T2* below the lower limit of the normal, T2* heterogeneity increased abruptly which could not be explained by artefactual effects. Some segmental T2* values were below and others above the limit of normal threshold (20 ms) in 104 (45%) TM patients. Among these patients, 74% showed a normal T2* global value. In conclusion, a true heterogeneity in the iron overload distribution may be present in TM patients. Heterogeneity seemingly appears in the borderline myocardial iron and stabilizes at moderate to severe iron burden. Copyright © 2009 John Wiley & Sons, Ltd.