bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and characterization of polyimides from 4‐(diphenyl phosphine oxide)phenyl pyrromellitic dianhydride
Authors: Bae Yeon‐Ung , Yoon Tae‐Ho
Published: September 2011

A novel rigid‐rod type dianhydride monomer with phosphine oxide moiety, 4‐(diphenyl phosphine oxide)phenyl pyrromellitic dianhydride (POPPMDA), was synthesized via the Suzuki coupling reaction of 4‐(diphenyl phosphine oxide)phenyl boronic acid (POBB) and 1‐bromo‐2,3,5,6‐tetramethyl benzene (B4MB), followed by oxidation and cyclodehydration. The monomer was characterized by FTIR, NMR, EA, and melting point analyzer and utilized to synthesize polyimides with diamines such as bis(3‐aminophenyl)phenyl phosphine oxide (mDAPPO) and p‐phenylene diamine (pPDA) by varying their ratio. The polyimides were prepared via a conventional two‐step synthesis: preparation of poly(amic‐acid), followed by solution imidization. The polyimides were characterized by FTIR, NMR, DSC, TGA, and TMA, and their solubility, intrinsic viscosity, and adhesive properties were also evaluated. The polyimides exhibited high Tg (342–362°C), good thermal stability (>500°C), excellent adhesive property (134–107 g/mm), and low CTE (28–17 ppm/°C). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Dystrophic Serotonin Axons in Postmortem Brains from Young Autism Patients
Authors: Azmitia Efrain C. , Singh Jorawer S. , Hou Xiao P. , Wegiel Jerzy
Published: September 2011

Autism causes neuropathological changes in varied anatomical loci. A coherent neural mechanism to explain the spectrum of autistic symptomatology has not been proposed because most anatomical researchers focus on point‐to‐point functional neural systems (e.g., auditory and social networks) rather than considering global chemical neural systems. Serotonergic neurons have a global innervation pattern. Disorders Research Program, AS073234, Program Project (JW). Their cell bodies are found in the midbrain but they project their axons throughout the neural axis beginning in the fetal brain. This global system is implicated in autism by animal models and by biochemical, imaging, pharmacological, and genetics studies. However, no anatomical studies of the 5‐HT innervation of autistic donors have been reported. Our review presents immunocytochemical evidence of an increase in 5‐HT axons in postmortem brain tissue from autism donors aged 2.8–29 years relative to controls. This increase is observed in the principle ascending fiber bundles of the medial and lateral forebrain bundles, and in the innervation density of the amygdala and the piriform, superior temporal, and parahippocampal cortices. In autistic donors 8 years of age and up, several types of dystrophic 5‐HT axons were seen in the termination fields. One class of these dystrophic axons, the thick heavily stained axons, was not seen in the brains of patients with neurodegenerative diseases. These findings provide morphological evidence for the involvement of serotonin neurons in the early etiology of autism, and suggest new therapies may be effective to blunt serotonin's trophic actions during early brain development in children. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Metabotropic Glutamate Receptor 5 Upregulation in Children with Autism is Associated with Underexpression of Both Fragile X Mental Retardation Protein and GABAA Receptor Beta 3 in Adults with Autism
Authors: Fatemi S. Hossein , Folsom Timothy D. , Kneeland Rachel E. , Liesch Stephanie B.
Published: September 2011

Recent work has demonstrated the impact of dysfunction of the GABAergic signaling system in brain and the resultant behavioral pathologies in subjects with autism. In animal models, altered expression of Fragile X mental retardation protein (FMRP) has been linked to downregulation of GABA receptors. Interestingly, the autistic phenotype is also observed in individuals with Fragile X syndrome. This study was undertaken to test previous theories relating abnormalities in levels of FMRP to GABAA receptor underexpression. We observed a significant reduction in levels of FMRP in the vermis of adults with autism. Additionally, we found that levels of metabotropic glutamate receptor 5 (mGluR5) protein were significantly increased in vermis of children with autism versus age and postmortem interval matched controls. There was also a significant decrease in level of GABAA receptor beta 3 (GABRβ3) protein in vermis of adult subjects with autism. Finally, we found significant increases in glial fibrillary acidic protein in vermis of both children and adults with autism when compared with controls. Taken together, our results provide further evidence that altered FMRP expression and increased mGluR5 protein production potentially lead to altered expression of GABAA receptors. Anat Rec,, 2011. © 2011 Wiley‐Liss, Inc.
Deconstructing Sociability, An Autism‐Relevant Phenotype, in Mouse Models
Authors: Fairless Andrew H. , Shah Rhia Y. , Guthrie Ashley J. , Li Hongzhe , Brodkin Edward S.
Published: September 2011

Reduced sociability is a core feature of autism spectrum disorders (ASD) and is highly disabling, poorly understood, and treatment refractory. To elucidate the biological basis of reduced sociability, multiple laboratories are developing ASD‐relevant mouse models in which sociability is commonly assessed using the Social Choice Test. However, various measurements included in that test sometimes support different conclusions. Specifically, measurements of time the “test” mouse spends near a confined “stimulus” mouse (chamber scores) sometimes support different conclusions from measurements of time the test mouse sniffs the cylinder containing the stimulus mouse (cylinder scores). This raises the question of which type of measurements are best for assessing sociability. We assessed the test‐retest reliability and ecological validity of chamber and cylinder scores. Compared with chamber scores, cylinder scores showed higher correlations between test and retest measurements, and cylinder scores showed higher correlations with time spent in social interaction in a more naturalistic phase of the test. This suggests that cylinder scores are more reliable and valid measures of sociability in mouse models. Cylinder scores are reported less commonly than chamber scores, perhaps because little work has been done to establish automated software systems for measuring the former. In this study, we found that a particular automated software system performed at least as well as human raters at measuring cylinder scores. Our data indicate that cylinder scores are more reliable and valid than chamber scores, and that the former can be measured very accurately using an automated video analysis system in ASD‐relevant models. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Experimental Strategies for Investigating Psychostimulant Drug Actions and Prefrontal Cortical Function in ADHD and Related Attention Disorders
Authors: Agster Kara L. , Clark Brian D. , Gao Wen‐Jun , Shumsky Jed S. , Wang Huaixing X. , Berridge Craig W. , Waterhouse Barry D.
Published: September 2011

Amphetamine‐like psychostimulant drugs have been used for decades to treat a variety of clinical conditions. Methylphenidate (MPH)—RitalinR, a compound that blocks reuptake of synaptically released norepinephrine (NE) and dopamine (DA) in the brain, has been used for more than 30 years in low dose, long‐term regimens to treat attention deficit‐hyperactive disorder (ADHD) in juveniles, adolescents, and adults. Now, these agents are also becoming increasingly popular among healthy individuals from all walks of life (e.g., military, students) and age groups (teenagers thru senior citizens) to promote wakefulness and improve attention. Although there is agreement regarding the primary biochemical action of MPH, the physiological basis for its efficacy in normal individuals and ADHD patients is lacking. Study of the behavioral and physiological actions of clinically and behaviorally relevant doses of MPH in normal animals provides an opportunity to explore the role of catecholamine transmitters in prefrontal cortical function and attentional processes as they relate to normal operation of brain circuits and ADHD pathology. The goal of ongoing studies has been to: (1) assess the effects of low dose MPH on rodent performance in a well characterized sensory‐guided sustained attention task, (2) examine the effects of the same low‐dose chronic MPH administration on task‐related discharge of prefrontal cortical (PFC) neurons, and (3) investigate the effects of NE and DA on membrane response properties and synaptic transmission in identified subsets of PFC neurons. Combinations of these approaches can be used in adolescent, adult, and aged animals to identify the parameters of cell and neural circuit function that are regulated by MPH and to establish an overarching explanation of how MPH impacts PFC operations from cellular through behavioral functional domains. Anat Rec,, 2011. © 2011 Wiley‐Liss, Inc.
Mucosal‐associated invariant T cells promote inflammation and exacerbate disease in murine models of arthritis
Authors: Chiba Asako , Tajima Ryohsuke , Tomi Chiharu , Miyazaki Yusei , Yamamura Takashi , Miyake Sachiko
Published: September 2011

Objective

The function of mucosal‐associated invariant T (MAIT) cells remains largely unknown. We previously reported an immunoregulatory role of MAIT cells in an animal model of multiple sclerosis. The aim of this study was to use animal models to determine whether MAIT cells are involved in the pathogenesis of arthritis.

Methods

MR1−/− and MR1+/+ DBA/1J mice were immunized with bovine type II collagen (CII) in complete Freund's adjuvant to trigger collagen‐induced arthritis (CIA). To assess CII‐specific T cell recall responses, lymph node cells from mice with CIA were challenged with CII ex vivo, and cytokine production and proliferation were evaluated. Serum levels of CII‐specific antibodies were measured by enzyme‐linked immunosorbent assay. Collagen antibody–induced arthritis (CAIA) was induced in MR1−/− and MR1+/+ C57BL/6 mice by injection of anti‐CII antibodies followed by injection of lipopolysaccharide. To demonstrate the involvement of MAIT cells in arthritis, we induced CAIA in MR1−/− C57BL/6 mice that had been reconstituted with adoptively transferred MAIT cells. MAIT cell activation in response to cytokine stimulation was investigated.

Results

The severity of CIA was reduced in MR1−/− DBA/1J mice. However, T and B cell responses to CII were comparable in MR1−/− and MR1+/+ DBA/1J mice. MR1−/− C57BL/6 mice were less susceptible to CAIA, and reconstitution with MAIT cells induced severe arthritis in MR1−/− C57BL/6 mice, demonstrating an effector role of MAIT cells in arthritis. MAIT cells became activated upon stimulation with interleukin‐23 (IL‐23) or IL‐1β in the absence of T cell receptor stimuli.

Conclusion

These results indicate that MAIT cells exacerbate arthritis by enhancing the inflammation.
Ultrasonographic evaluation of medial radial displacement of the medial meniscus in knee osteoarthritis
Authors: Kawaguchi Kei , Enokida Makoto , Otsuki Ryoji , Teshima Ryota
Published: September 2011

Objective

To evaluate medial radial displacement (MRD) of the medial meniscus in osteoarthritic (OA) and normal knees, with and without weight bearing, using ultrasonography (US), and to prospectively evaluate the time course of changes in MRD in OA knees.

Methods

The study subjects were 78 patients with OA of the knee (69% female; mean age 66.4 years) and 20 healthy, asymptomatic subjects (70% female; mean age 64.5 years) who served as a control group. The OA stage was determined according to the Kellgren/Lawrence (K/L) radiographic grading system. US measurement of MRD was performed with subjects in the supine and standing positions. With the exception of subjects who dropped out, 58 OA knees (followup rate 74%) were evaluated at baseline and ∼1 year later.

Results

The medial meniscus was significantly displaced radially by weight bearing in control knees (P < 0.001) and in knees with K/L grades 1–3 OA (P < 0.01 for each comparison). MRD in either the supine or the standing position was not significantly different between the control knees and the K/L grade 1 knees, but significant differences were noted between the control knees and K/L grade 2 or more severe OA knees (P < 0.01 for each comparison). MRD of the medial meniscus had increased significantly on followup in all knees (P < 0.05 for each comparison) excluding K/L grade 4 knees in the standing position.

Conclusion

MRD of the medial meniscus increased with weight bearing and during followup. These findings suggest a close association between extraarticular displacement of the medial meniscus and progression of OA.
Noncardiac vascular disease in rheumatoid arthritis: Increase in venous thromboembolic events?
Authors: Bacani A. Kirstin , Gabriel Sherine E. , Crowson Cynthia S. , Heit John A. , Matteson Eric L.
Published: September 2011

Objective

To investigate the incidence of noncardiac vascular disease in a community‐based incidence cohort of patients with rheumatoid arthritis (RA) and compare it to that in the general population and to investigate trends in the incidence of noncardiac vascular disease in patients with RA.

Methods

A population‐based inception cohort of patients with incident RA between January 1, 1980 and December 31, 2007 in Olmsted County, Minnesota and a cohort of non‐RA subjects from the same population base was assembled and followed up until December 31, 2008. Venous thromboembolic, cerebrovascular, and peripheral arterial events were ascertained by medical record review.

Results

The study population included 813 patients with RA with a mean ± SD age of 55.9 ± 15.7 years (68% women) and an average length of followup of 9.6 ± 6.9 years. Compared to non‐RA subjects of similar age and sex, patients diagnosed as having RA between 1995 and 2007 had a higher incidence (%) of venous thromboembolism (cumulative incidence ± SE 6.7 ± 1.7 versus 2.8 ± 1.1, respectively; P = 0.005) but similar rates of cerebrovascular and peripheral arterial events. Among patients with RA, the incidence of venous thromboembolic, cerebrovascular, and peripheral arterial events was similar in the 1995–2007 time period compared to the 1980–1994 time period.

Conclusion

Our findings indicate that the incidence of venous thromboembolism is increased in patients with RA compared to non‐RA subjects. The incidence of cerebrovascular events and peripheral vascular disease events is similar in patients with RA compared to non‐RA subjects. Among patients with RA, the incidence of noncardiac vascular disease has remained stable in recent decades.
Protease‐activated receptor 2, rather than protease‐activated receptor 1, contributes to the aggressive properties of synovial fibroblasts in rheumatoid arthritis
Authors: Xue Meilang , Chan Yee‐Ka Agnes , Shen Kaitlin , Dervish Suat , March Lyn , Sambrook Philip N. , Jackson Christopher J.
Published: September 2011

Objective

To investigate whether protease‐activated receptor 1 (PAR‐1) and/or PAR‐2 promotes the invasiveness/proliferation of synovial fibroblasts (SFs) and to determine the signaling mechanisms of these pathways.

Methods

SFs were isolated from the synovial tissue of patients with rheumatoid arthritis (RA), patients with osteoarthritis (OA), and PAR‐1– or PAR‐2–knockout (KO) mice. Expression of PAR‐1 and PAR‐2 was detected by immunofluorescence and Western blotting. The invasion and proliferation of SFs were measured by invasion assay and MTT assay, respectively. Matrix metalloproteinase 2 (MMP‐2) and MMP‐9 were detected by zymography, and cytokines were measured by enzyme‐linked immunosorbent assay.

Results

PAR‐1 and PAR‐2 were colocalized with SFs in RA and OA synovium and, to a considerably lesser extent, in normal synovium. Inhibition of PAR‐2 by small interfering RNA (siRNA) inhibited RASF invasion and proliferation, whereas blocking of PAR‐1 by siRNA had the reverse effects. SFs from PAR‐2–KO mice exhibited slower rates of proliferation and invasion. SFs from PAR‐1–KO mice produced less MMP‐2 and, in response to tumor necrosis factor α (TNFα) stimulation, had increased MMP‐9 secretion when compared to SFs from wild‐type and PAR‐2–KO mice. Inhibition of PAR‐1, but not PAR‐2, stimulated the secretion of interleukin‐17 (IL‐17) and TNFα by RASFs. Furthermore, PAR‐1 and PAR‐2 had opposing effects on the activation of ERK, p38, and NF‐κB.

Conclusion

Activation of PAR‐1 stimulates MMP‐2 secretion, inhibits RASF growth and invasion, and decreases production of IL‐17 and TNFα by RASFs, whereas activation of PAR‐2 stimulates RASF growth and invasion and increases production of TNFα. Thus, although PAR‐1 and PAR‐2 are coexpressed by RASFs, PAR‐2 alone appears to be responsible for the aggressive properties of RASFs and is likely to contribute to the pathologic progression of RA.
Heterogeneous nuclear RNPs as targets of autoantibodies in systemic rheumatic diseases
Authors: Op De Beéck Katrijn , Maes Liesbeth , Van den Bergh Karolien , Derua Rita , Waelkens Etienne , Van Steen Kristel , Vermeersch Pieter , Westhovens René , De Vlam Kurt , Verschueren Patrick , Hooijkaas Herbert , Blockmans Daniel , Bossuyt Xavier
Published: September 2011

Objective

To investigate the abundance of autoantibodies to heterogeneous nuclear RNPs (hnRNPs) in systemic rheumatic diseases.

Methods

Recombinant human hnRNPs A1, B1, C1, E1, F, Gi, H1, I, K, and P2 were prepared. Antibodies to these antigens were determined by Western blotting and by enzyme‐linked immunosorbent assay (ELISA) (for hnRNPs B1, E1, F, and H1) in serum samples obtained from patients with chronic fatigue syndrome (control subjects) and from patients with various connective tissue diseases.

Results

Western blotting analysis in 106 control subjects and 298 patients with a connective tissue disease revealed that antibodies to all tested hnRNP antigens, except hnRNP Gi, were significantly more prevalent in patients with Sjögren's syndrome (SS) than in control subjects. The highest reactivity was observed for hnRNPs B1, E1, F, and H1 (reactivity in >45% of patients with SS and in 2.8% of control subjects). Reactivity with hnRNPs B1, E1, F, and H1 was also evaluated by ELISA in 89 control subjects and 228 patients with a connective tissue disease. Reactivity with at least 2 of the 4 tested antigens was observed in 1.1% of control subjects, 16% of patients with systemic lupus erythematosus (SLE), and 18% of patients with SS. Reactivity with at least 3 of the 4 antigens was observed in 0% of the control subjects, 3.2% of patients with SLE, and 15% of patients with SS.

Conclusion

Several hnRNPs are target antigens in SS. The combined presence of antibodies to several hnRNPs was strongly associated with connective tissue disease in general and with SS in particular.
Mechanisms involved in enhancement of the expression and function of aggrecanases by hyaluronan oligosaccharides
Authors: Ariyoshi Wataru , Takahashi Nobunori , Hida Daisuke , Knudson Cheryl B. , Knudson Warren
Published: September 2011

Objective

Small hyaluronan (HA) oligosaccharides serve as competitive receptor antagonists to displace HA from the cell surface and induce cell signaling events. In articular chondrocytes, this cell signaling is mediated by the HA receptor CD44 and induces stimulation of genes involved in matrix degradation, such as matrix metalloproteinases (MMPs) as well as matrix repair genes including type II collagen, aggrecan, and HA synthase 2. The objective of this study was to determine changes in the expression and function of aggrecanases after disruption of chondrocyte CD44–HA interactions.

Methods

Bovine articular chondrocytes or bovine cartilage tissue was pretreated with a variety of inhibitors of major signaling pathways prior to the addition of HA oligosaccharides. Changes in aggrecanase were monitored by real‐time reverse transcription–polymerase chain reaction and Western blot analyses of ADAMTS‐4, ADAMTS‐5, and aggrecan proteolytic fragments. To test the interactions between ADAMTS‐4 and membrane type 4 MMP (MT4‐MMP), protein lysates purified from stimulated chondrocytes were subjected to coimmunoprecipitation.

Results

Disruption of chondrocyte CD44–HA interactions with HA oligosaccharides induced the transcription of ADAMTS‐4 and ADAMTS‐5 in a time‐ and dose‐dependent manner. The association of glycosyl phosphatidylinositol–anchored MT4‐MMP with ADAMTS‐4 was also induced in articular chondrocytes by HA oligosaccharides. Inhibition of the NF‐κB pathway blocked HA oligosaccharide‐mediated stimulation of aggrecanases.

Conclusion

Disruptive changes in chondrocyte–matrix interactions by HA oligosaccharides induce matrix degradation and elevate aggrecanases via the activation of the NF‐κB signaling pathway.
Soluble VE‐cadherin in rheumatoid arthritis patients correlates with disease activity: Evidence for tumor necrosis factor α–induced VE‐cadherin cleavage
Authors: Sidibé Adama , Mannic Tiphaine , Arboleas Mélanie , Subileau Mariela , Gulino‐Debrac Danielle , Bouillet Laurence , Jan Mary , Vandhuick Thibault , Le Loët Xavier , Vittecoq Olivier , Vilgrain Isabelle
Published: September 2011

Objective

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disorder that principally attacks synovial joints. However, accelerated atherosclerosis and increased cardiovascular morbidity and mortality are major clinical consequences of endothelial dysfunction in RA patients. Tumor necrosis factor α (TNFα) is the major mediator of inflammation in RA, related to vascular injury by targeting VE‐cadherin, an endothelium‐specific adhesion molecule of vital importance for endothelium integrity and angiogenesis. We undertook this study to examine the mechanisms regulating VE‐cadherin processing by TNFα and their occurrence in RA.

Methods

Human umbilical vein endothelial cells were used in primary culture and treated with recombinant TNFα to study VE‐cadherin cleavage. Cell lysates and conditioned media were analyzed by Western blotting for VE‐cadherin cytoplasmic domain and extracellular domain (VE‐90) generation, respectively. VE‐90 was analyzed at baseline and at the 1‐year followup in sera from 63 RA patients (from the Very Early Rheumatoid Arthritis cohort) with disease duration of <6 months.

Results

TNFα induced a time‐dependent shedding of VE‐90 in cell media. This effect was prevented by tyrosine kinase inhibitors (genistein and PP2) or by knocking down Src kinase. In contrast, tyrosine phosphatase blockade enhanced VE‐cadherin cleavage, confirming the requirement of tyrosine phosphorylation processes. In addition, using the matrix metalloproteinase (MMP) activator APMA and the MMP inhibitor GM6001, we demonstrated that MMPs are involved in TNFα‐induced VE‐cadherin cleavage. Of major importance, VE‐90 was detected in sera from the 63 RA patients and was positively correlated with the Disease Activity Score at baseline and after 1‐year followup.

Conclusion

These findings provide the first evidence of VE‐cadherin proteolysis upon TNFα stimulation and suggest potential clinical relevance of soluble VE‐cadherin in management of RA.
Output feedback integral sliding mode controller of time‐delay systems with mismatch disturbances
Authors: Ting Huan‐Chan , Chang Jeang‐Lin , Chen Yon‐Ping
Published: September 2011

For uncertain time‐delay systems with mismatch disturbances, this paper presented an integral sliding mode control algorithm using output information only. An integral sliding surface is comprised of output signals and an auxiliary full‐order compensator. The designed output feedback sliding mode controller can locally satisfy the reaching and sliding condition and maintain the system on the sliding surface from the initial moment. Since the system is in the sliding mode and two specific algebraic Riccati inequalities are established, the proposed algorithm can guarantee the stability of the closed‐loop system and satisfy the property of disturbance attenuation. Moreover, the design parameters of the controller and compensator can be simultaneously determined by solutions to two algebraic Riccati inequalities. Finally, a numerical example illustrates the applicability of the proposed scheme.

Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
A guide to stem cell identification: Progress and challenges in system‐wide predictive testing with complex biomarkers
Authors: Williams Roy , Schuldt Bernhard , Müller Franz‐Josef
Published: September 2011

We have developed a first generation tool for the unbiased identification and characterization of human pluripotent stem cells, termed PluriTest. This assay utilizes all the information contained on a microarray and abandons the conventional stem cell marker concept. Stem cells are defined by the ability to replenish themselves and to differentiate into more mature cell types. As differentiation potential is a property that cannot be directly proven in the stem cell state, biologists have to rely on correlative measurements in stem cells associated with differentiation potential. Unfortunately, most, if not all, of those markers are only valid within narrow limits of specific experimental systems. Microarray technologies and recently next‐generation sequencing have revolutionized how cellular phenotypes can be characterized on a systems‐wide level. Here we discuss the challenges PluriTest and similar global assays need to address to fulfill their enormous potential for industrial, diagnostic and therapeutic applications.
Simultaneous use of urea and potassium nitrate for Arthrospira (Spirulina) platensis cultivation
Authors: Vieira Denise C. M. , Matsudo Marcelo C. , Sato Sunao , Converti Attilio , de Carvalho João C. M.
Published: September 2011

Urea has been considered as a promising alternative nitrogen source for the cultivation of Arthrospira platensis if it is possible to avoid ammonia toxicity; however, this procedure can lead to periods of nitrogen shortage. This study shows that the addition of potassium nitrate, which acts as a nitrogen reservoir, to cultivations carried out with urea in a fed‐batch process can increase the maximum cell concentration (Xm) and also cell productivity (PX). Using response surface methodology, the model indicates that the estimated optimum Xm can be achieved with 17.3 mM potassium nitrate and 8.9 mM urea. Under this condition an Xm of 6077 ± 199 mg/L and a PX of 341.5 ± 19.1 mg L–1day–1 were obtained.
A clinical assay for the measurement of milrinone in plasma by HPLC mass spectrometry
Authors: Chihoho B. , Sage A. B. , Smolenski R. T. , Vazir A. , Rose M. L. , Banner N. R. , Leaver N. V.
Published: September 2011

Milrinone is a bipyridine phosphodiesterase inhibitor with positive inotropic and vasodilatory effects. As interest in longer term use of intravenous therapy increases, it becomes essential to monitor its plasma concentration owing to a narrow therapeutic range, an increased half‐life in renal failure and toxicity associated with high levels. A high‐performance liquid chromatography (HPLC) method with mass (MS) detection using a triple quadrupole mass spectrometer is presented. The method was compared with the UV/HPLC method and validated according to current international guidelines. Coefficients of variation of less than 7.5% were obtained across the therapeutic range and 18.3% at 2.4 ng/mL, the lower limit of quantitation. Plasma from 13 cardiac surgery patients receiving standard intravenous doses of milrinone were measured. Eight patients achieved therapeutic milrinone levels within 3–4 h post start of infusion, one was borderline sub‐therapeutic and four patients achieved levels that were above the upper limit of the therapeutic range and potentially toxic. This method offers high sensitivity, is rapid, easy to use and requires minimal amount of sample. We believe this method could become the reference procedure for clinical monitoring of milrinone and help to improve the safety of the use of this drug in patients with cardiac failure. Copyright © 2011 John Wiley & Sons, Ltd.
Rapid and sensitive LC‐MS/MS method for quantification of lamotrigine in human plasma: application to a human pharmacokinetic study
Authors: Hotha Kishore Kumar , Kumar S.Sirish , Bharathi D. Vijaya , Venkateswarulu V.
Published: September 2011

A highly sensitive, specific and fully validated LC‐MS/MS method as per general practices of industry has been developed for estimation of lamotrigine (LAM) with 100 μL of human plasma using flucanozole as an internal standard (IS). The API‐4000 LC‐MS/MS was operated under the multiple reaction‐monitoring mode using electrospray ionization. A simple liquid–liquid extraction process was used to extract LAM and IS from human plasma. The total run time was 2.0 min and the elution of LAM and IS occurred at 1.25 and 1.45 min; this was achieved with a mobile phase consisting of 0.1% formic acid–methanol (20:40:40, v/v) at a flow rate of 0.50 mL/min on a Discovery CN (50 × 4.6 mm, 5 µm) column. The developed method was validated in human plasma with a lower limit of quantitation of 0.1 ng/mL for LAM. A linear response function was established for the range of concentrations 0.1–1500 ng/mL (r > 0.998) for LAM. The intra‐ and inter‐day precision values for LAM met the acceptance as per Food and Drug Administration guidelines. LAM was stable in the set of stability studies, viz. bench‐top, autosampler and freeze–thaw cycles. The developed assay method was applied to an oral bioequivalence study in humans. Copyright © 2011 John Wiley & Sons, Ltd.
Amyloid fibril formation from crude protein mixtures
Authors: Rao Shiva P. , Meade Susie J. , Joyce Nigel I. , Healy Jackie P. , Sutton Kevin H. , Larsen Nigel G. , Gerrard Juliet A.
Published: September 2011

Amyloid fibrils have potential as bionanomaterials. A bottleneck in their commercial use is the cost of the highly purified protein typically needed as a starting material. Thus, an understanding of the role of heterogeneity in the mixtures from which amyloid fibrils are formed may inform production of these structures from readily available impure starting materials. Insulin, a very well understood amyloid‐forming protein, was modified by various reagents to explore whether amyloid fibrils could still form from a heterogeneous mixture of insulin derivatives. Aggregates were characterized by thioflavin T fluorescence and transmission electron microscopy. Using acetylation, reduction carboxymethylation, reduction pyridylethylation, trypsin digestion and chymotrypsin digestion, it was shown that amyloid fibrils can form from heterogeneous mixtures of modified insulin. The modifications changed both the rate of reaction and the yield of the final product, but led to fibrillar structures, some with interesting morphologies. Well defined, long, unbranched fibrils were observed in the crude reduced carboxymethylated insulin mixture and the crude reduced pyridylethylated insulin revealed the formation of “wavy” fibrils, compared with the straighter native insulin amyloid fibrils. Although trypsin digestion inhibited fibrils formation, chymotrypsin digestion of insulin produced a mixture of long and short fibrils under the same conditions. We conclude that amyloid fibrils may be successfully formed from heterogeneous mixtures and, further, that chemical modification may provide a simple means of manipulating protein fibril assembly for use in bionanotechnological applications, enabling some design of overall morphology in the bottom‐up assembly of higher order protein structures from amyloid fibrils. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Secretion of elastin‐like polypeptides with different transition temperatures by Pichia pastoris
Authors: Schipperus Roelof , Eggink Gerrit , de Wolf Frits A.
Published: September 2011

Like natural tropoelastin, polypeptides based on an elastin‐like VPGXG repeat have a characteristic inverse temperature response, which leads to coacervate formation above a certain transition temperature and which could be useful for a variety of applications. The key advantage of elastin‐like polypeptides (ELPs) over (tropo)elastin is a full control over this temperature response by adjustment of either the amino acid composition or the chain length, according to insights provided by extensive research. Future application of ELPs will require efficient ELP production systems, and in a previous article, we described the successful use of Pichia pastoris for secreted production of an ELP, with an overall yield of ∼ 200 mg L−1. In this study, we investigated the influence of changed amino acid composition and chain length on the yield of secreted ELP. We have found that both parameters have a distinct impact on the overall yield, with higher yield for shorter and more hydrophilic ELPs. Because yield and transition temperature (Tt) thus appear to be positively correlated, we hypothesize that good solubility of ELP below the Tt promotes the secreted production and coacervate formation above Tt decreases it. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2012
A new aqueous biphasic system containing polypropylene glycol and a water‐miscible ionic liquid
Authors: Zafarani‐Moattar Mohammed Taghi , Hamzehzadeh Sholeh , Nasiri Saeed
Published: September 2011

In this work, we proposed a novel aqueous biphasic system (ABS) composed of polypropylene glycol P400 (PPG P400) and hydrophilic ionic liquids (IL), 1‐alkyl‐3‐methylimidazolium bromide (alkyl = ethyl or butyl), forming an upper polymer‐rich phase and a lower IL‐rich phase at ambient temperature. This new ABS can present interesting characteristics shared by ILs and polymers such as low volatility, good solvation ability, tunable physical properties, and high design capacity for achieving task‐specific phase components to enhance the partitioning of target species. Ternary phase diagram of the novel ABS formed by PPG 400 and [C2mim]Br in water was measured at T = 298.15 K. Factors affecting the binodal curves such as the cation side alkyl chain length and the temperature were also evaluated. The results were successfully interpreted in terms of the kosmotropic/chaotropic nature of ILs. Furthermore, the phase behavior of the PPG‐[C2mim]Br ABS is described by the NRTL model. Finally, the extraction potential of the proposed ABS was evaluated through its application to the extraction of the essential amino acids such as L‐tryptophan and L‐tyrosine. The partition coefficients here obtained demonstrated the fine potential of the proposed ABS for biomolecules separation. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Predictive tool for recombinant protein production in Escherichia coli Shake‐Flask cultures using an on‐line monitoring system
Authors: Kunze Martin , Huber Robert , Gutjahr Claudia , Müllner Stefan , Büchs Jochen
Published: September 2011

As Escherichia coli (E. coli) is well defined with respect to its genome and metabolism, it is a favored host organism for recombinant protein production. However, many processes for recombinant protein production run under suboptimal conditions caused by wrong or incomplete information from an improper screening procedure, because appropriate on‐line monitoring systems are still lacking. In this study, the oxygen transfer rate (OTR), determined on‐line in shake flasks by applying a respiration activity monitoring system (RAMOS) device, was used to characterize the metabolic state of the recombinant organisms. Sixteen clones of E. coli SCS1 with foreign gene sequences, encoding for different target proteins, were cultivated in an autoinduction medium, containing glucose, lactose, and glycerol, to identify relationships between respiration activity and target protein production. All 16 clones showed a remarkably different respiration activity, biomass, and protein formation under induced conditions. However, the clones could be classified into three distinct types, and correlations could be made between OTR patterns and target protein production. For two of the three types, a decrease of the target protein was observed, after the optimal harvest time had passed. The acquired knowledge was used to modify the autoinduction medium to increase the product yield. Additional 1.5 g/L glucose accelerated the production process for one clone, shifting the time point of the maximal product yield from 24 to 17 h. For another clone, lactose addition led to higher volumetric product yields, in fact 25 and 38% more recombinant protein for 2 and 6 g/L additional lactose, respectively. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Detoxification of azo dyes mediated by cell‐free supernatant culture with manganese‐dependent peroxidase activity: Effect of Mn2+ concentration and H2O2 dose
Authors: Contreras Elsa , Urra Johana , Vásquez Carlos , Palma Carolyn
Published: September 2011

White‐rot fungi (WRF) are capable of degrading complex organic compounds such as lignin, and the enzymes that enable these processes can be used for the detoxification of recalcitrant organopollutants. The aim of this study is to evaluate a system based on the use of an in vitro ligninolytic enzyme for the detoxification of recalcitrant dye pollutants. The dyes selected for investigation were the anionic and cationic commercial azo dyes, basic blue 41 (BB41), acid black 1 (AB1), and reactive black 5 (RB5). A supernatant, cell‐free culture of WRF with manganese peroxidase activity was used to investigate its degradative capacity under various conditions, and concentrations of cofactors, H2O2 and Mn2+. The assays were carried out using a 22 experimental designs whose variables were concentration of Mn2+ (33 and 1,000 μM) and semicontinuous dosage of the H2O2 (0.02 and 0.10 μmol) added at a frequency of 0.2 min−1. The response variables analyzed were the efficiency and the initial rate of the decolorization process. The dye concentrations considered ranged from 10 to 200 mg L−1. AB1 and RB5 were decolorized over the entire interval of concentrations studied; reaching efficiencies between 15 and 95%. Decolorization of up to 100 mg L−1, BB41 had less than 30% efficiency. The decay of the concentration of AB1 was interpreted by two‐stage kinetics model, with the exception of the condition of 33 μM Mn2+–0.02 μmol of H2O2 in which only one stage was observed. For all assays performed with 33 μM Mn2+, the initial rate of the decolorization process was found to be dependent on the dosage of H2O2. The results of this study can be applied to the development bioreactors for the degradation of recalcitrant pollutants from the textile industry and may be used as a model for expanding the use of extracellular enzyme supernatants in bioremediation. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Delineation of the Core Aggregation Sequences of TDP‐43 C‐Terminal Fragment
Authors: Saini Akash , Chauhan Virander Singh
Published: September 2011

Ubiquitinated cytoplasmic inclusions of TDP‐43 and its C‐terminal cleavage products are the pathological hallmarks of amyotrophic lateral sclerosis and frontotemporal lobar degeneration with ubiquitinated inclusions. The C‐terminal fragments (CTFs) of TDP‐43 are increasingly considered to play an important role in its aggregation and in disease. Here, we employed a set of synthetic peptides spanning the length of the TDP‐43 CTF (220–414) in order to find out its core aggregation domains. Two regions, one in the RRM‐2 domain (246–255) and the other in the C‐terminal domain (311–320) of TDP‐43, stand out as highly aggregation prone. Studies done on recombinant purified TDP‐43 CTF and its three mutants, in which these sequences were deleted individually and together, suggested that the 311–320 region has a more crucial role to play than the 246–255 in its aggregation. The study helps in defining specific peptide sequences that might form the core of TDP‐43 aggregation. Identification of these sequences could help in designing peptide based inhibitors of TDP‐43 aggregation.
Identification of Anchor Points for Chemical Modification of a Small Cysteine‐Rich Protein by Using a Cysteine Scan
Authors: Vinther Tine N. , Ribel Ulla , Åskov Pedersen Thomas , Kjeldsen Thomas B. , Jensen Knud J. , Hubálek František
Published: September 2011

Chemical modifications of proteins are increasingly important in the development of protein drugs with fine‐tuned properties. Regioselective modification, such as the chemoselective alkylation of an unpaired cysteine residue, is a prerequisite for obtaining homogenous protein products. The introduction of an unpaired Cys into the Cys‐rich protein, insulin, was investigated by using a Cys scan. This was challenging as the introduced Cys could interfere with insulin’s three existing disulfide bonds. However, eight insulin precursors were expressed in Saccharomyces cerevisiae with good yields. Although extensive post‐translational modifications of the unpaired Cys were observed, the majority could be removed by selective reduction. An example Cys7 insulin analogue was modified with a PEGylated maleimide moiety. The new variant was active in in vitro and in vivo models. Our results show that even small Cys‐rich proteins can be expressed with additional unpaired Cys in meaningful yields and further chemically modified, while maintaining their biological activity.
Autoinductive Exponential Signal Amplification: A Diagnostic Probe for Direct Detection of Fluoride
Authors: Perry‐Feigenbaum Rotem , Sella Eran , Shabat Doron
Published: September 2011

A new example of an exponential signal amplification strategy for the direct detection of fluoride is demonstrated. The amplification occurred through reaction of fluoride with a responsive chromogenic probe. The probe activity is based on a unique dendritic chain reaction that generates a fluoride anion, which is the analyte of interest, during the disassembly pathway of the dendritic probe. This autoinductive amplification mechanism may be applied for detection of other analytes by coupling activity of a modified probe with that of the fluoride amplifier.
Proton‐Coupled Electron Transfer Originating from Excited States of Luminescent Transition‐Metal Complexes
Authors: Wenger Oliver S.
Published: September 2011

Proton‐coupled electron transfer (PCET) is of fundamental importance for small‐molecule activation processes, such as water splitting, CO2‐reduction, or nitrogen fixation. Ideally, energy‐rich molecules such as H2, CH3OH, or NH3 could be generated artificially using (solar) light as an energy input. In this context, PCETs originating directly from electronically excited states play a crucial role. A variety of transition‐metal complexes have been used recently for fundamental investigations of this important class of reactions, and the key findings of these studies are reviewed in this article. The present minireview differs from other reviews on the subject of PCET in that it focuses specifically on reactions occurring directly from electronically excited states.
ChemInform Abstract: Effects of Pr Doping on Thermoelectric Transport Properties of Ca3‐xPrxCo4O9.
Authors: Zhang F. P. , Zhang X. , Lu Q. M. , Zhang J. X. , Liu Y. Q. , Zhang G. Z.
Published: September 2011

Powders of the title compounds with x = 0, 0.05, 0.1, 0.2, and 0.3 are prepared by the sol—gel method starting with stoichiometric amounts of Ca(NO3)2, Pr(NO3)3, and Co(NO3)2 dissolved in aqueous citric acid solution (heating of the obtained gel at 1073 K for 8 h).
ChemInform Abstract: Emergence of Superconductivity in “32522” Structure of (Ca3Al2O5‐y)(Fe2Pn2) (Pn: As and P).
Authors: Shirage Parasharam M. , Kihou Kunihiro , Lee Chul‐Ho , Kito Hijiri , Eisaki Hiroshi , Iyo Akira
Published: September 2011

Polycrystalline samples of the title compounds are prepared from mixtures of CaO, Fe, Al, Fe2O3, and As or P (4.5 GPa, 1150 °C for Pn: As and 1300 °C for Pn: P, 1 h).
ChemInform Abstract: Layered LixMoO2 Phases with Different Composition for Electrochemical Application: Structural Considerations.
Authors: Mikhailova D. , Bramnik N. N. , Bramnik K. G. , Reichel P. , Oswald S. , Senyshyn A. , Trots D. M. , Ehrenberg H.
Published: September 2011

Li1.0MoO2 (I), Li0.91MoO2 (II), and Li0.75MoO2 (III) are synthesized by solid state reactions of stoichiometric mixtures of Li2MoO4, Mo, and MoO3 (alumina crucibles, 1223 K, 20 h) and characterized by single crystal XRD, powder XRD, XPS, and electrochemical measurements.
ChemInform Abstract: Stabilizing Low‐Valent Refractory Metals in a Strongly Oxidizing Medium: The First Molybdenum(V) Sulfate ‐ MoO(HSO4)(SO4) ‐ From Mo(CO)6 in Oleum.
Authors: Betke Ulf , Neuschulz Kai , Wickleder Mathias S.
Published: September 2011

Deep‐blue single crystals of MoO(HSO4)(SO4) are prepared from Mo(CO)6 in oleum (sealed glass ampule, 200 °C, 2 d).
ChemInform Abstract: Toward a Reliable Synthesis of Strontium Ruthenate: Parameter Control and Property Investigation of Submicrometer‐Sized Structures.
Authors: Tiano Amanda L. , Santulli Alexander C. , Koenigsmann Christopher , Feygenson Mikhail , Aronson M. C. , Harrington Richard , Parise John B. , Wong Stanislaus S.
Published: September 2011

Single‐crystalline SrRuO3 submicrometer‐sized particles are synthesized by reaction of Sr(OH)2·8H2O, RuO2 nanoparticles, and 1% mineral oil in Triton X‐100 surfactant in a NaCl/KCl flux (porcelain crucible, air, 700 °C; quenching).
ChemInform Abstract: Synthesis and Characterization of [PW11O39Ir(H2O)]4‐: Successful Incorporation of Ir into Polyoxometalate Framework and Study of the Substitutional Lability at the Ir(III) Site.
Authors: Sokolov Maxim N. , Adonin Sergey A. , Mainichev Dmitry A. , Vicent Cristian , Zakharchuk Nina F. , Danilenko Andrey M. , Fedin Vladimir P.
Published: September 2011

Title compound (III) is synthesized from two different polytungstate precursors and characterized by XRD, 31P and 183W NMR, ESI‐mass spectrometry, and cyclic voltammetry.
ChemInform Abstract: Indium‐Mediated Radical Addition of Perfluoroalkyl Iodide in Water.
Authors: Takagi Toshiyuki , Kanamori Toshiyuki
Published: September 2011

Introduction of perfluoroalkyl group into C—C unsaturated compounds is achieved using indium metal in water.
ChemInform Abstract: A Highly Recyclable Magnetic Core‐Shell Nanoparticle‐Supported TEMPO Catalyst for Efficient Metal‐ and Halogen‐Free Aerobic Oxidation of Alcohols in Water.
Authors: Karimi Babak , Farhangi Elham
Published: September 2011

The highly efficient heterogeneous catalyst is used for the aerobic oxidation of primary, secondary, allylic, and even sterically hindered alcohols in water.
ChemInform Abstract: Ruthenium‐Catalyzed Regio‐ and Enantioselective Allylic Substitution with Water: Direct Synthesis of Chiral Allylic Alcohols.
Authors: Kanbayashi Naoya , Onitsuka Kiyotaka
Published: September 2011

The simplicity and availability of the nucleophile, the mild conditions, and the broad scope of the allylic chlorides are features of the present reaction.
ChemInform Abstract: Nickel‐Catalyzed Cross‐Coupling of Aryl Bromides with Tertiary Grignard Reagents Utilizing Donor‐Functionalized N‐Heterocyclic Carbenes (NHCs).
Authors: Lohre Claudia , Droege Thomas , Wang Congyang , Glorius Frank
Published: September 2011

The Kumada cross‐coupling of tertiary alkyl Grignard reagents with aryl bromides provides a selective access to highly substituted alkylbenzene derivatives.
ChemInform Abstract: Preparation of Functionalized Organomanganese(II) Reagents by Direct Insertion of Manganese to Aromatic and Benzylic Halides.
Authors: Peng Zhihua , Knochel Paul
Published: September 2011

Various arylmanganese compounds are prepared from aryl halides under the optimized conditions shown.
ChemInform Abstract: Intramolecular 1,4‐Addition of Nitrogen Nucleophile and Bromine Electrophile to Conjugated 1,3‐Enyne.
Authors: Liu Na , Werness Jenny B. , Guzei Ilia A. , Tang Weiping
Published: September 2011

It is discovered, that 1,4‐halocyclization of conjugate enynes (I) and (VII) is intrinsically favored over 1,2‐addition.
ChemInform Abstract: New Experimental Conditions for Tandem Hydroalumination/Cu‐Catalyzed Asymmetric Conjugate Additions to β‐Substituted Cyclic Enones.
Authors: Mueller Daniel , Tissot Matthieu , Alexakis Alexandre
Published: September 2011

A variety of alkenylalanes is applied in cyclopentenone, cyclohexenone and cycloheptenone derivatives using SimplePhos monodentate ligands.