bluuebunny/crossref_metadata_2025 huggingface dataset:
Using PA6 as a charring agent in intumescent polypropylene formulations based on carboxylated polypropylene compatibilizer and nano‐montmorillonite synergistic agent
Authors: Ma Zhi‐Ling , Zhang Wei‐Yan , Liu Xin‐Yu
Published: April 2006

The intumescent fire retardant polypropylene (IFP/PP) filled with ammonium polyphosphate (APP), melamine (M), and PA6 (charring agent) is discussed. Intumescing degree (ID) and the char yield were determined. Only when the three main components of IFR coexist at appropriate proportions, it has optimal ID and higher char yield. The appropriate proportion is PA6 : APP : M = 10 : 10 : 5. A new compatibilizer, carboxylated polypropylene (EPP), was added to PP/PA‐6 blend. Flow tests indicated that the apparent viscosity increased with the addition of EPP, thermal characterization suggested that EPP has reacted with PA6, PA6‐g‐EPP cocrystallized with PA6, and EPP‐g‐PA6 cocrystallized with PP; SEM micrographs illustrated that the presence of EPP improved the compatibility of PP and PA6. All the investigations showed that EPP was an excellent compatibilizer, and it was a true coupling agent for PP/PA6 blends. Using PA6 as a charring agent resulted in the IFR/PP dripping, which deteriorated the flammability properties. The addition of nano‐montmorillonite (nano‐MMT) as a synergistic agent of IFR enabled to overcome the shortcoming. The tensile test testified that the addition of nano‐MMT enhanced the mechanical strength by 44.3%. SEM showed that nano‐MMT improved the compatibility of the composites. It was concluded that the intumescent system with nano‐MMT was an effective flame retardant in improving combustion properties of polypropylene. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 739–746, 2006
Fatty esters of cellulose from olive pomace and barley bran: Improved mechanical properties by metathesis crosslinking
Authors: Memmi Abdelmajid , Granet Robert , Gahbiche Mohamed Amen , Fekih Abdelwahab , Bakhrouf Amina , Krausz Pierre
Published: April 2006

Agricultural wastes such as olive pomace and barley bran have been transformed in plastic by esterification with fatty acid chlorides after acidic or alkaline delignification. These esterifications were carried out in homogenous solution DMA/LiCl by classical heating or microwave activation. The plastics obtained were characterized by IR and NMR spectra, and tested for their mechanical properties and potentiality of biodegradation. The mechanical properties were improved by olefin metathesis of undecylenic ester from olive cellulose. delignification. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 751–755, 2006
Structure development of poly(L‐lactic acid) fibers processed at various spinning conditions
Authors: Ghosh Subhas , Vasanthan Nadarajah
Published: April 2006

Poly(L‐lactic acid) (PLA) filaments were spun by melt‐spinning at 500 and 1850 mm−1, and further drawn and heat‐set to modify the morphology of these PLA filaments. PLA yarns were characterized by wide‐angle X‐ray diffraction (WAXD) and sonic method. WAXD reveals that PLA yarns spun at 500 mm−1 are almost amorphous while the PLA filaments spun at 1850 mm−1 have about 6% crystallinity. This is different from PET filaments spun at the same speed that have almost no crystallinity. Both drawn‐ and heat‐set PLA filaments showed much higher crystallinity (60%) than do as‐spun fibers produced at 500 and 1850 mm−1 speed, which is also higher than the usual heat‐set PET yarns. It appears that crystalline orientation rapidly reaches a value in the order of 0.95 at 1850 mm−1 and that drawn‐ and heat‐set yarns have almost the same crystalline orientation values. Molecular orientation is relatively low for as‐spun PLA yarn, and molecular orientation increased to ∼0.5 after drawing or heat–setting or both. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1210–1216, 2006
Polymer membranes for separating organic mixtures
Authors: Bang‐Xiao Cai
Published: April 2006

Polyvinyl alcohol (PVA), polyacrylonitrile (PAN), and cellulose ester were respectively chosen as the separation layer and the support in the composite membranes based on the concept of the solubility parameter and the permselectivities for separating ethanol/water mixture, isopropanol/water mixture, and caprolactam/water mixture. The effects of the membrane materials and the construction of the composite membrane on the separation performance were preliminary discussed. The separation performance of the membranes prepared by several making‐membrane techniques, i.e., the polymer solution making‐membrane technique, and the membrane treatment technique (heat treatment, organic solvent modification) were presented. The composite membranes of PVA/PAN and PVA/cellulose acetate, and cellulose triacetate hollow fiber membrane modified, which possess good performance in separating the organic systems, were developed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1160–1164, 2006
Kinetics of the interaction of desAABB–fibrin monomer with immobilized fibrinogen
Authors: Chtcheglova Lilia A. , Vogel Monique , Gruber Hermann J. , Dietler Giovanni , Haeberli André
Published: April 2006

The soluble and stable fibrin monomer–fibrinogen complex (SF) is well known to be present in the circulating blood of healthy individuals and of patients with thrombotic diseases. However, its physiological role is not yet fully understood. To deepen our knowledge about this complex, a method for the quantitative analysis of interaction between soluble fibrin monomers and surface‐immobilized fibrinogen has been established by means of resonant mirror (IAsys) and surface plasmon resonance (BIAcore) biosensors. The protocols have been optimized and validated by choosing appropriate immobilization procedures with regeneration steps and suitable fibrin concentrations. The highly specific binding of fibrin monomers to immobilized fibrin(ogen), or vice versa, was characterized by an affinity constant of ∼10−8M, which accords better with the direct dissociation of fibrin triads (KD≈ 10−8–10−9M) (J. R. Shainoff and B. N. Dardik,Annals of the New York Academy of Science, 1983, Vol. 27, pp. 254–268) than with earlier estimations of theKDfor the fibrin–fibrinogen complex (KD≈ 10−6M) (J. L. Usero, C. Izquierdo, F. J. Burguillo, M. G. Roig, A. del Arco, and M. A. Herraez,International Journal of Biochemistry, 1981, Vol. 13, pp. 1191–1196). © 2006 Wiley Periodicals, Inc. Biopolymers 83: 69–82, 2006

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Modulating the affinity and the selectivity of engineered calmodulin EF‐Hand peptides for lanthanides
Authors: Clainche Loïc Le , Figuet Mélanie , Montjardet‐Bas Véronique , Blanchard Sébastien , Vita Claudio
Published: April 2006

A set of engineered peptides (33 amino acids long) corresponding to the helix‐turn‐helix (EF‐Hand) motif of the metal‐binding site I of the protein calmodulin from paramecium tetraurelia have been synthesized. A disulfide bridge has been introduced in the native sequence in order to stabilize a native‐like conformation. The calcium‐binding carboxylate residues in positions 20, 22, 24, and 31 were mutated into other amino acids and the influence of such mutations on the binding affinity of the peptides for calcium and lanthanides have been studied. It was shown that the binding affinity for terbium ions can be modulated with dissociation constants ranging from 40 nmolar to 40 mmolar. The study of the influence of the mutations on the terbium affinity showed that the residue in position 24 played a key role on the capability of the peptides to bind lanthanides and that the affinity could be enhanced by mutations on non‐coordinating positions. Such peptides with high affinity for lanthanides may facilitate the development of new highly sensitive biosensors to monitor the metal pollution in the environment. © 2006 Wiley Periodicals, Inc.
NIR Lanthanide Luminescence by Energy Transfer from Appended Terpyridine–Boradiazaindacene Dyes
Authors: Ziessel Raymond F. , Ulrich Gilles , Charbonnière Loïc , Imbert Daniel , Scopelliti Rosario , Bünzli Jean‐Claude G.
Published: April 2006

Mononuclear trivalent lanthanide complexes with formula [Ln(L)(NO3)3] [in which L=4,4‐difluoro‐8‐(2′:2′′;6′′:2′′′‐terpyridin‐4′′‐yl)‐1,3,5,7‐tetramethyl‐2,6‐diethyl‐4‐bora‐3a,4a‐diaza‐s‐indacene (Boditerpy)] are reported for Ln=Yb, Nd, Er, La and Gd. According to the crystal structure of the Yb complex, the lanthanide ion is bound to the terdentate terpyridine and the inner coordination sphere of the nine‐coordinate lanthanide ion is completed by three bidentate nitrate anions. The coordination polyhedron can be described as a distorted tricapped antiprism. The terpyridine chelate is almost planar and tilted by nearly 60° from the indacene subunit. FT‐IR spectra confirm the bidentate binding mode of the nitrate anions for the other complexes. NMR and ES‐MS spectra (through characteristic isotopic patterns) confirm the chemical formulation. The complexes have high molar absorption coefficients in the visible spectral region (65 000 M−1 cm−1 at 529 nm) and display sizeable NIR luminescence (900 to 1600 nm, for Ln=Yb, Nd and Er), upon irradiation through the electronic state of the indacene moiety at 514 nm. Crystal‐field splitting was analysed at low temperature. The quantum yield of the Yb solution (10−4 M) in dichloromethane amounts to 0.31 %, corresponding to a sensitisation efficacy of the ligand of ca. 63 %.
Pd‐Catalyzed Cyclization of 1‐Allyl‐2‐indolecarboxamides by Intramolecular Amidation of Unactivated Ethylenic Bond.
Authors: Abbiati Giorgio , Beccalli Egle , Broggini Gianluigi , Martinelli Michela , Paladino Giuseppe
Published: April 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Manganese(II) Oxidation and Mn(IV) Reduction in the Environment — Two One‐Electron Transfer Steps Versus a Single Two‐Electron Step
Authors: Luther George W. III
Published: April 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Chemistry of 1‐Aryl‐6‐azauracil‐5‐carbonitriles
Authors: Frysova Iveta , Mutina Vojtech , Slouka Jan , Hlavac Jan
Published: April 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Association between adiponectin, insulin resistance, and endometrial cancer
Authors: Soliman Pamela T. , Wu Diana , Tortolero‐Luna Guillermo , Schmeler Kathleen M. , Slomovitz Brian M. , Bray Molly S. , Gershenson David M. , Lu Karen H.
Published: April 2006

BACKGROUND

Obesity is a well known risk factor for the development of endometrial cancer; however, weight alone does not account for all cases. The authors hypothesized that insulin resistance also contributes to an increased risk for endometrial cancer. Adiponectin is a protein secreted by adipose cells and has been shown to be a surrogate marker for insulin resistance, with low levels of adiponectin correlated with hyperinsulinemia and degree of insulin resistance. The purpose of the current study was to determine whether there was an independent association between adiponectin level and endometrial cancer.

METHODS

A case–control study was performed on 117 endometrial cancer patients (cases) and 238 women with no history of cancer (controls). Serum adiponectin levels were measured using enzyme‐linked immunoadsorbent assay and examined for their association with endometrial cancer. Univariate and multivariate logistic regression analyses were performed with adjustment for confounding factors.

RESULTS

The mean serum adiponectin levels were significantly lower among cases (88.8 ± 63.3 ng/mL) than among controls (148.2 ± 68.3; P<.001). This inverse correlation continued to be observed after controlling for age, body mass index, diabetes, and hypertension. Cases were significantly more likely to have serum adiponectin levels in the lowest (odds ratio [OR] of 10.5; 95% confidence interval [95% CI], 4.49‐24.57 [P<.001]) and intermediate tertiles (OR of 2.5; 95% CI, 1.01‐6.21 [P = .05]) when compared with controls.

CONCLUSIONS

Adiponectin level was found to be independently and inversely associated with endometrial cancer. Women with endometrial cancer were more likely to have low adiponectin levels than controls, even after adjusting for body mass index. This suggested that insulin resistance is independently associated with endometrial cancer. Cancer 2006. © 2006 American Cancer Society.
A phase II trial of pegylated interferon α‐2b therapy for polycythemia vera and essential thrombocythemia
Authors: Samuelsson Jan , Hasselbalch Hans , Bruserud Oystein , Temerinac Snezana , Brandberg Yvonne , Merup Mats , Linder Olle , Bjorkholm Magnus , Pahl Heike L. , Birgegard Gunnar ,   Nordic Study Group for Myeloproliferative Disorders
Published: April 2006

BACKGROUND

Conventional interferon‐α (IFN) is an effective treatment for patients with myeloproliferative disorders. However, many patients discontinue therapy because of side effects.

METHODS

In this 24‐month, Phase II feasibility study of pegylated interferon α‐2b (PEG‐IFN) treatment, a starting dose of 0.5 μg/kg per week was received by 21 patients with polycythemia vera (PV) and 21 patients with essential thrombocythemia (ET). The treatment objective, a complete platelet response (CR), was a platelet count <400 × 109/L in symptomatic patients and <600 in asymptomatic patients. Neutrophil polycythemia rubra vera‐1 (PRV‐1) messenger RNA expression was analyzed prior to and during therapy. Quality of life (QoL) was investigated by using the European Organization for Research and Treatment of Cancer QLQ‐C30 questionnaire.

RESULTS

At 6 months, 29 of 42 patients (69%) had achieved a CR after a median of 83 days. The CR rate was not related to diagnosis, gender, or previous therapy. Nineteen patients completed the planned 2‐year treatment in CR. No thromboembolic or bleeding complications were observed. Phlebotomy requirements were reduced in the majority of patients with PV. Five of 14 patients (36%) who initially were positive for PRV‐1 achieved normalized PRV‐1 expression under PEG‐IFN treatment. Side effects were the cause of therapy failure in 16 of 23 patients. However, only 8 of 19 patients reported any side effects at 2 years. The QLQ‐C30 revealed clinically significant impairments in several aspects of QoL at 6 months; however, at 2 years, QoL measurements were not different from baseline.

CONCLUSIONS

PEG‐IFN effectively reduced platelet counts in 29 of 42 patients, but only 19 patients maintained a CR at 2 years. The reversal of PRV‐1 positivity noted in a subset of patients suggested that PEG‐IFN may have an effect on the malignant clone. PEG‐IFN is a valuable therapeutic alternative for patients who tolerate its initial side effects. Cancer 2006. © 2006 American Cancer Society.
Stages in gully evolution and self‐organized criticality
Authors: Sidorchuk Aleksey
Published: April 2006

The process of gully erosion at the active stage is far from equilibrium; rather, the gully shows the characteristics of a self‐organizing system that is close to crisis. This qualitative description is similar to the understanding of open dynamic systems at a state of selforganized criticality (SOC). We tried to find the quantitative attributes of SOC in numerical simulations of gully evolution with a dynamic gully erosion model. Three scenarios were used: (1) gully evolution is controlled by initial topography and texture, when the discharge and base level are constant; (2) discharge is constant and the base level lowers over time; (3) the base level is constant and the discharge changes naturally. The results of numerical simulations of gully evolution are consistent with the expectations of the SOC theory. Under the first scenario, when the gully was at the initial active stage of evolution, the system showed all the SOC attributes: a fractal long profile; a ‘red‐noise’ spectrum; and the power‐law frequency–magnitude relationship (FMR). With gully stabilization, the system had lost SOC behaviour and became non‐fractal, with a ‘blue‐noise’ spectrum and exponential FMR. For this scenario SOC criteria can be used to find the boundary between active and stable states of gully evolution. Simulations under the second scenario showed that the riverbed incision made the active stage of the gully evolution with all SOC attributes much longer than with a stable base level. Simulation under the third scenario, with variable discharge (with the elements of SOC), showed that the SOC attributes of the hydrological system could be induced on the landform system. While the gully had evidently reached the stable stage, the process of gully volume change still indicated active‐stage SOC attributes. Therefore some landform systems can really be in the SOC stage, which can diagnose their activity; others only show SOC attributes induced by climatic or hydrologic systems. Copyright © 2006 John Wiley & Sons, Ltd.
Expression Analysis of LacZ gene placed in the locus of Cnot7 exhibits its activity in osteoblasts in vivo and in mineralized nodules in vitro
Authors: Washio‐Oikawa Kaoru , Nakamura Takahisa , Usui Michihiko , Yoneda Mitsuhiro , Ezura Youichi , Ishikawa Isao , Nakashima Kazuhisa , Yamamoto Tadashi , Noda Masaki
Published: April 2006

CCR4‐NOT complex 7 (Cnot7) was identified as a regulator of gene expression in yeast and evolutionally conserved in mammals. Cnot7 deficient male mice exhibit abnormality in spermatogenesis. As these mice contained construct to express LacZ, we followed the expression patterning in these animals. LacZ was expressed in osteoblasts located in the primary spongiosa in adult mice. Cellular analysis indicated that LacZ is expressed in osteoblasts but not in osteoclasts. In the mineralized nodules formed in the culture of bone marrow cells obtained from Cnot7 +/− mice, LacZ expression was mainly observed in the cells forming mineralized nodules but not in un‐mineralized area scattered around the periphery of the nodules. LacZ blue positive cells were gradually depositing minerals along its time course of the in vitro mineralization assay. Cnot7 expression was enhanced by the treatment with BMP. These data suggest that Cnot7 is expressed in osteoblasts and is associated with mineralization. J. Cell. Biochem. 99: 538–544, 2006. © 2006 Wiley‐Liss, Inc.
The regulation of glucose transporter (GLUT1) expression by the RNA binding protein HuR
Authors: Gantt Kira R. , Cherry Joy , Richardson Melissa , Karschner Vesna , Atasoy Ulus , Pekala Phillip H.
Published: April 2006

HuR is a ligand for nuclear mRNAs containing adenylate‐uridylate‐rich (ARE) elements in the 3′‐untranslated region. Once bound to the mRNA, HuR is recognized by adapter proteins that then facilitate nuclear export of the complex. In the cytosol, HuR is thought to function to control stability and translation of its ligand message. We have previously demonstrated that HuR is constitutively expressed in the 3T3‐L1 cells and shuttles from the nucleus to the cytosol, but remains predominantly nuclear in the preadipocytes and that as the cells differentiate, there is a marked increase in the proportion of HuR in the cytosol at any time. The GLUT1 glucose transporter is also expressed in both preadipocytes and adipocytes and in vitro RNA gel shifts indicate the mRNA is a ligand for HuR. However, HuR complexes containing the GLUT1 mRNA can only be isolated from the terminally differentiated adipocytes. Moreover, position analysis of the GLUT1 mRNA and HuR protein in polysome profiles demonstrates a shift to the most dense region of the gradient for both message and protein with adipocyte differentiation. Consistent with a regulatory role in the control of GLUT1 expression, siRNA‐mediated decrease in HuR protein resulted in a decreased expression of GLUT1 protein. These data suggest that HuR contributes to the metabolic function of the adipocyte through mediation of post‐transcriptional regulatory events. J. Cell. Biochem. 99: 565–574, 2006. © 2006 Wiley‐Liss, Inc.
Comparison of pelvic floor muscle training, electromyography biofeedback, and neuromuscular electrical stimulation for bladder dysfunction in people with multiple sclerosis: A randomized pilot study
Authors: McClurg D. , Ashe R.G. , Marshall K. , Lowe‐Strong A.S.
Published: April 2006

Aim

Bladder dysfunction affects up to 90% of the multiple sclerosis (MS) population. Interventions such as Pelvic Floor Training and Advice (PFTA), Electromyography (EMG) Biofeedback, and Neuromuscular Electrical Stimulation (NMES) have received limited research attention within this population. This study aimed to determine the effectiveness of a combined programme of PFTA, EMG Biofeedback, and NMES for bladder dysfunction in MS.

Methods

Females (n = 30) who fulfilled strict inclusion/exclusion criteria were recruited. Outcome measures (weeks 0, 9, 16, and 24) included: 3‐day Voiding Diary; 24 hr Pad‐Test; Uroflowmetry; Pelvic Floor Muscle Assessment; Incontinence Impact Questionnaire (IIQ); Urogenital Distress Inventory (UDI); King's Health Questionnaire (KHQ), and the Multiple Sclerosis Quality of Life‐54 Instrument (MSQoL‐54). Following baseline (week 0) assessment, participants were randomly allocated, under double blind conditions, to one of the three groups: Group 1 (PFTA); Group 2 (PFTA and EMG Biofeedback); and Group 3 (PFTA, EMG Biofeedback, and NMES). Treatment was for 9 weeks.

Results

Baseline severity (measured by number of leaks and pad weight) showed some variation between groups, although not statistically significant (P > 0.05); with the caveat that this baseline imbalance makes interpretation difficult, a picture emerges that at week 9, Group 3 demonstrated superior benefit as measured by the number of leaks and pad test than Group 2, with Group 1 showing less improvement when compared to week 0; this was statistically significant between Groups 1 and 3 for number of leaks (P = 0.014) and pad tests (P = 0.001), and Groups 1 and 2 for pad tests (P = 0.001). A similar pattern was evident for all other outcome measures.

Conclusion

Results suggest that these treatments, used in combination, may reduce urinary symptoms in MS. Further research will establish the effectiveness of these interventions. Neurourol. Urodynam. © 2006 Wiley‐Liss, Inc.
The stochastic joint replenishment problem: A new policy, analysis, and insights
Authors: Özkaya Banu Yüksel , Gürler Ülkü , Berk Emre
Published: April 2006

In this study, we propose a new parsimonious policy for the stochastic joint replenishment problem in a single‐location, N‐item setting. The replenishment decisions are based on both group reorder point‐group order quantity and the time since the last decision epoch. We derive the expressions for the key operating characteristics of the inventory system for both unit and compound Poisson demands. In a comprehensive numerical study, we compare the performance of the proposed policy with that of existing ones over a standard test bed. Our numerical results indicate that the proposed policy dominates the existing ones in 100 of 139 instances with comparably significant savings for unit demands. With batch demands, the savings increase as the stochasticity of demand size gets larger. We also observe that it performs well in environments with low demand diversity across items. The inventory system herein also models a two‐echelon setting with a single item, multiple retailers, and cross docking at the upper echelon. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006
Differential expression of glucocorticoid receptor in human breast tissues and related neoplasms
Authors: Lien H‐C , Lu Y‐S , Cheng A‐L , Chang W‐C , Jeng Y‐M , Kuo Y‐H , Huang C‐S , Chang K‐J , Yao Y‐T
Published: April 2006

Glucocorticoid receptor (GR) is a steroid hormone receptor that has been shown to play important roles in mammary development and differentiation, and has been implicated in breast tumourigenesis, but its precise biological significance in mammary pathophysiology remains unclear. In order to generate a comprehensive expression profile for GR in normal versus neoplastic breast tissues, GR expression was investigated in situ in 400 human breast tissue samples, comprising normal tissue and a range of benign, pre‐invasive, and invasive lesions, using immunohistochemical assays. The novel expression of GR in myoepithelium, not observed in luminal epithelium, not only demonstrates expression patterns exclusive to the alpha form of oestrogen receptor and progesterone receptor and suggests distinctive functions between GR and these two important steroid hormone receptors in the breast, but may also indicate unique physiological and perhaps pathological roles for the myoepithelium in mediating the effects of glucocorticoid hormones in the breast. The strong expression of GR in metaplastic carcinomas (94.4%) and malignant phyllodes tumours (92.3%) suggests a pathogenetic role for GR, and implies that targeting GR in these tumours may have potential therapeutic application. However, studies on the roles of GR in mammary carcinogenesis should be interpreted with great caution, based on the lack of GR expression in cancer cells in the great majority (98.2%) of non‐metaplastic carcinomas, which has gone unnoticed in previous studies. This marked discrepancy warrants a re‐examination of the biological roles of GR in the pathophysiology of breast malignancy. The lack of methylation in the promoter region of the GR gene in all 118 non‐metaplastic carcinomas, as demonstrated by methylation‐specific PCR and bisulphite DNA sequencing analysis, indicates that methylation is less likely to play a role in the reduction of GR expression in non‐metaplastic carcinoma of the breast. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Pharmakotherapie und Leitlinien: Das Parkinson‐Syndrom
Authors: Baas Horst
Published: April 2006

Insgesamt kann durch einen abgestimmten Einsatz der beschriebenen pharmakotherapeutischen Maßnahmen die Parkinson‐Symptomatik in der Regel über einen Zeitraum von 15 bis 25 Jahren unter Wahrung einer zumindest befriedigenden Lebensqualität ausreichend gebessert werden und die Lebenserwartung der Patienten signifikant gesteigert werden.
Scattering and Transmission by a Monolayer of Spheres: A Study on the Monolayer Structure
Authors: Shen Jianqi , Riebel Ulrich , Guo Xiaoai
Published: April 2006

The angular distribution of scattered light and the transmission of radiation through a monolayer of monodisperse spherical particles at variable particle concentration are studied. The scattering of light by a single particle is calculated with the classical Lorentz‐Mie theory. For a monolayer of mono‐dispersed spherical particles, if the monolayer density is less than 0.5 and the particle size parameter is larger than 5, effects from multiple scattering and dependent scattering can be excluded so that only steric interactions are considered. It is found that the scattering pattern, especially in the forward and backward directions, and the transmission are strongly dependent on the monolayer density.
Semiconductor Nanowires: From Self‐Organization to Patterned Growth
Authors: Fan Hong Jin , Werner Peter , Zacharias Margit
Published: April 2006

The synthesis of semiconductor nanowires has been studied intensively worldwide for a wide spectrum of materials. Such low‐dimensional nanostructures are not only interesting for fundamental research due to their unique structural and physical properties relative to their bulk counterparts, but also offer fascinating potential for future technological applications. Deeper understanding and sufficient control of the growth of nanowires are central to the current research interest. This Review discusses the various growth processes, with a focus on the vapor–liquid–solid process, which offers an opportunity for the control of spatial positioning of nanowires. Strategies for position‐controlled and nanopatterned growth of nanowire arrays are reviewed and demonstrated by selected examples as well as discussed in terms of larger‐scale realization and future prospects. Issues on building up nanowire‐based electronic and photonic devices are addressed at the end of the Review, accompanied by a brief survey of recent progress demonstrated so far on the laboratory level.
Neuropsychiatric and Cognitive Changes after Surgery for Primary Hyperparathyroidism
Authors: Dotzenrath Cornelia M.E. , Kaetsch Ana Karena , Pfingsten Henrich , Cupisti Kenko , Weyerbrock Norbert , Vossough Alexander , Verde Pablo E. , Ohmann Christian
Published: April 2006

Introduction

Neuropsychiatric symptoms and cognitive impairment are mental manifestations of primary hyperparathyroidism (pHPT). The aim of our study was to determine if surgical treatment results in a long‐lasting full recovery from these symptoms.

Methods

In a prospective case‐control study with matching pairs, mental changes were examined preoperatively and 6 months postoperatively in 30 patients with primary hyperparathyroidism and 30 patients with nontoxic nodular goiter using the Hamilton depression score and four cognitive tests: DEM Tect, MWT (multiple word test), ZVT, and Benton test.

Results

Patients with pHPT demonstrated significantly more cognitive changes (P < 0.0001) with significant improvement 6 months postoperatively (P < 0.0001). Patients with pHPT presented more psychopathologic symptoms than patients of the control group (P = NS), and there was a tendency towards recovery in the pHPT group postoperatively. There was no correlation between biochemistry and psychopathologic or cognitive changes in the pHPT group.

Conclusions

Patients with pHPT often present with neuropsychiatric symptoms and cognitive impairment. A successful parathyroid operation improves cognitive disorders in particular.
Increased Src kinase level results in increased protein tyrosine phosphorylation in scrapie‐infected neuronal cell lines
Authors: Gyllberg Hanna , Löfgren Kajsa , Lindegren Heléne , Bedecs Katarina
Published: April 2006

In addition, an important increase in the protein tyrosine phosphorylation signal was observed in ScGT1 and ScN2a cells, which was further shown to be Src‐dependent, as treatment with PP2 – a Src family kinase specific inhibitor, reversed the protein tyrosine phosphorylation profile. Abnormal Src‐kinase activation and subsequent protein tyrosine phosphorylation may be key elements in the neuropathology of the prion diseases.
Hexapeptides that interfere with HIV‐1 fusion peptide activity in liposomes block GP41‐mediated membrane fusion
Authors: Gómara María J. , Lorizate Maier , Huarte Nerea , Mingarro Ismael , Perez-Payá Enrique , Nieva José L.
Published: April 2006

Upon receptor‐mediated activation, the gp41 hydrophobic, conserved fusion peptide inserts into the target membrane and promotes the kind of perturbations required for the progression of the HIV‐cell fusion reaction. Using a synthetic combinatorial library we have identified all d‐amino acid hexapeptide sequences that inhibited the fusion peptide capacity of perturbing model membranes. Two hexapeptides that effectively inhibited the fusion peptide in these systems were subsequently shown to inhibit cell–cell fusion promoted by gp41 expressed at cell surfaces. These observations might be of importance for understanding the mechanisms underlying fusion peptide activity and suggest new strategies for screening compounds that target these viral sequences.
Crystal structure of dimeric FabZ of Plasmodium falciparum reveals conformational switching to active hexamers by peptide flips
Authors: Swarnamukhi P. Lakshmi , Sharma Shailendra Kumar , Bajaj Preeti , Surolia Namita , Surolia Avadhesha , Suguna Kaza
Published: April 2006

The crystal structure of β‐hydroxyacyl acyl carrier protein dehydratase of Plasmodium falciparum (PfFabZ) has been determined at a resolution of 2.4 Å. PfFabZ has been found to exist as a homodimer (d‐PfFabZ) in the crystals of the present study in contrast to the reported hexameric form (h‐PfFabZ) which is a trimer of dimers crystallized in a different condition. The catalytic sites of this enzyme are located in deep narrow tunnel‐shaped pockets formed at the dimer interface. A histidine residue from one subunit of the dimer and a glutamate residue from the other subunit lining the tunnel form the catalytic dyad in the reported crystal structures. While the position of glutamate remains unaltered in the crystal structure of d‐PfFabZ compared to that in h‐PfFabZ, the histidine residue takes up an entirely different conformation and moves away from the tunnel leading to a His‐Phe cis–trans peptide flip at the histidine residue. In addition, a loop in the vicinity has been observed to undergo a similar flip at a Tyr–Pro peptide bond. These alterations not only prevent the formation of a hexamer but also distort the active site geometry resulting in a dimeric form of FabZ that is incapable of substrate binding. The dimeric state and an altered catalytic site architecture make d‐PfFabZ distinctly different from the FabZ structures described so far. Dynamic light scattering and size exclusion chromatographic studies clearly indicate a pH‐related switching of the dimers to active hexamers.
Role of thioredoxin‐1 in apoptosis induction by α‐tocopheryl succinate and TNF‐related apoptosis‐inducing ligand in mesothelioma cells
Authors: Freeman Ruth E. , Neuzil Jiri
Published: April 2006

Malignant mesothelioma (MM) is a fatal type of cancer. We studied the role of the redox‐active protein thioredoxin‐1 (Trx‐1) in apoptosis induced in MM cells and their non‐malignant counterparts (Met‐5A) by α‐tocopheryl succinate (α‐TOS) and TNF‐related apoptosis‐inducing ligand (TRAIL). MM cells were susceptible to α‐TOS and less to TRAIL, while Met‐5A cells were susceptible to TRAIL and resistant to α‐TOS. MM cells expressed very low level of the Trx‐1 protein, which was high in Met‐5A cells, while the level of Trx‐1 mRNA was similar in all cell lines. Downregulation of Trx‐1 further sensitised Met‐5A cells to TRAIL but not to α‐TOS. Our data suggest that the role of Trx‐1 in apoptosis modulation is unrelated to its anti‐oxidant properties.
The logic of TGFβ signaling
Authors: Massagué Joan , Gomis Roger R.
Published: April 2006

The identification of the TGFβ cytokine signaling pathway, including membrane receptor serine/threonine kinases and Smad transcription factors as their substrates, has allowed the delineation of a process for conversion of these signals into programs of gene activation and repression that underlie critical cell fate and developmental decisions. The deconstruction of one of these responses – the cell cycle arrest response – into its elemental molecular parts has shed light into the mechanisms used by tumors to evade surveillance and cause metastasis.
Origin of electroretinogram amplitude growth during light adaptation in pigmented rats
Authors: BUI BANG V. , FORTUNE BRAD
Published: April 2006

We assessed the growth of the rat photopic electroretinogram (ERG) during light adaptation and the mechanisms underlying this process. Full field ERG responses were recorded from anesthetized adult Brown–Norway rats at each minute for 20 min of light adaptation (backgrounds: 1.8, 2.1, 2.4 log scotopic cd m−2). The rat photopic b-wave amplitude increased with duration of light adaptation and its width at 33% maximal amplitude narrowed (by ∼ 40 ms). These effects peaked 12–15 min after background onset. The narrowing of the b-wave reflected steepening of the b-wave recovery phase, with little change in the rising phase. OP amplitudes grew in proportion to the b-wave. Inhibition of inner retinal responses using TTX resulted in a greater relative growth of b-wave and OP amplitude compared with fellow control eyes, and delayed the change in recovery phase by ∼ 5 min. Inhibition of all ionotropic glutamate receptors with CNQX/D-AP7 delayed both rising and recovery phases equally (∼ 12 ms) without altering b-wave width or the time course of adaptation changes. These outcomes suggest that inner retinal light responses are not directly responsible for b-wave amplitude growth, but may contribute to the change in its recovery phase during adaptation. A TTX-sensitive mechanism may help to hasten this process. The cone a-wave was isolated using PDA/L-AP4 or CNQX/L-AP4. A-wave amplitude (35 ms after stimulus onset) also increased with time during light adaptation and reached a maximum (130 ± 29% above baseline) 12–15 min after background onset. B-wave amplitude growth in fellow control eyes closely followed the course and relative magnitude of cone a-wave amplitude growth. Hence, the increase of the cone response during light adaptation is sufficient to explain b-wave amplitude growth.
Responses of the teleostean nucleus isthmi to looming objects and other moving stimuli
Authors: GALLAGHER SHAWN P. , NORTHMORE DAVID P.M.
Published: April 2006

Visually evoked extracellular neural activity was recorded from the nucleus isthmi (NI) of goldfish and bluegill sunfish. When moving anywhere within the right eye's visual field, three-dimensional checkered balls or patterns on a computer screen evoked bursts of spikes in the left NI. Object motion parallel to the longitudinal body axis gave responses that habituated markedly upon repetition, but movement into recently unstimulated regions of the visual field gave vigorous responses. Thus, while NI's response is not visuotopic, its habituation is. An object approaching the animal's body generated a rising spike density, whereas object recession generated only a transient burst. During the approach of a checkered stimulus ball, average NI spike density rose linearly as the ball-to-eye distance decreased and at a rate proportional to the ball's speed (2.5–30 cm/s). Increasing ball size (2.2–9.2 cm) did not affect the rate of activity rise at a given speed, but did increase overall activity levels. NI also responded reliably to expanding textures of fixed overall size. The results suggest that NI signals changes in motion of objects relative to the fish, and estimates the proximity of approaching objects.
The number, morphology, and distribution of retinal ganglion cells and optic axons in the Australian lungfishNeoceratodus forsteri(Krefft 1870)
Authors: BAILES HELENA J. , TREZISE ANN E.O. , COLLIN SHAUN P.
Published: April 2006

Australian lungfishNeoceratodus forsterimay be the closest living relative to the first tetrapods and yet little is known about their retinal ganglion cells. This study reveals that lungfish possess a heterogeneous population of ganglion cells distributed in a horizontal streak across the retinal meridian, which is formed early in development and maintained through to adult stages. The number and complement of both ganglion cells and a population of putative amacrine cells within the ganglion cell layer are examined using retrograde labelling from the optic nerve and transmission electron-microscopic analysis of axons within the optic nerve. At least four types of retinal ganglion cells are present and lie predominantly within a thin ganglion cell layer, although two subpopulations are identified, one within the inner plexiform and the other within the inner nuclear layer. A subpopulation of retinal ganglion cells comprising up to 7% of the total population are significantly larger (>400 μm2) and are characterized as giant or alpha-like cells. Up to 44% of cells within the retinal ganglion cell layer represent a population of presumed amacrine cells. The optic nerve is heavily fasciculated and the proportion of myelinated axons increases with body length from 17% in subadults to 74% in adults. Spatial resolving power, based on ganglion cell spacing, is low (1.6–1.9 cycles deg−1,n= 2) and does not significantly increase with growth. This represents the first detailed study of retinal ganglion cells in sarcopterygian fish, and reveals that, despite variation amongst animal groups, trends in ganglion cell density distribution and characteristics of cell types were defined early in vertebrate evolution.
Cannabinoid agonist WIN 55212-2 speeds up the cone response to light offset in goldfish retina
Authors: STRUIK MIEKE L. , YAZULLA STEPHEN , KAMERMANS MAARTEN
Published: April 2006

Goldfish cones contain CB1 receptors at the synaptic terminal, selectively accumulate3H-anandamide, and contain fatty acid amide hydrolase-immunoreactivity, and voltage-gated calcium and potassium currents are modulated by CB1 ligands (Yazulla et al., 2000; Fan & Yazulla, 2003; Glaser et al., 2005). These data suggest that a retinal mechanism may account for some of the psychophysical effects of cannabis. Here, we studied the effect of a cannabinoid agonist on cone light responses. Whole-cell patch-clamp recordings were made from cones in the isolated goldfish retina. Cones were stimulated with a spot of light of variable wavelength and intensities in combination with voltage-and current-clamp protocols. Pharmacological manipulation was performed using the cannabinoid agonist WIN 55212-2 (10 μM). WIN had no effect on the absolute sensitivity of the cones or on the kinetics of the onset response. However, the light-offset response became faster, and the depolarizing overshoot was enhanced. Time constant of the offset response was reduced from 292 ± 28 ms to 180 ± 11 ms (n= 6) (P< 0.01) in the presence of WIN. Acceleration of the offset response was not affected by flash length from 200 ms to 10 s. This was found under current-clamp as well as under voltage-clamp conditions, indicating that the effect of WIN was mediated directly or indirectly by modulation of the cGMP-gated channels in the outer segment of the cones. The effects of WIN were not blocked by the CB1 antagonist SR141716A. With a train of “dark” flashes from a steady background, the photocurrent recovered toward baseline more quickly with WIN than in Control. In summary, cannabinoids speed up the dynamics of the phototransduction deactivation cascade in the cone outer segments. The functional consequence of this effect is to shorten the recovery time to the offset of bright flashes, perhaps resulting in an increase in contrast sensitivity.
Measurements of Zinc Absorption: Application and Interpretation in Research Designed to Improve Human Zinc Nutriture
Authors: Hambidge K. Michael , Miller Leland V. , Tran Cuong D. , Krebs Nancy F.
Published: April 2006

The focus of this paper is on the application of measurements of zinc absorption in human research, especially studies designed to assess the efficacy of intervention strategies to prevent and manage zinc deficiency in populations. Emphasis is given to the measurement of quantities of zinc absorbed rather than restricting investigations to measurements of fractional absorption of zinc. This is especially important when determining absorption of zinc from the diet, whether it be the habitual diet or an intervention diet under evaluation. Moreover, measurements should encompass all meals for a minimum of one day with the exception of some pilot studies. Zinc absorption is primarily via an active saturable transport process into the enterocytes of the proximal small intestine. The relationship between quantity of zinc absorbed and the quantity ingested is best characterized by saturable binding models. When applied to human studies that have sufficient data to examine dose-response relationships, efficiency of absorption is high until approximately 50–60% maximal absorption is achieved, even with moderate phytate intakes. This also coincides approximately with the quantity of absorbed zinc necessary to meet physiologic requirements. Efficiency of absorption with intakes that exceed this level is low or very low. These observations have important practical implications for the design and interpretation of intervention studies to prevent zinc deficiency. They also suggest the potential utility of measurements of the quantity of zinc absorbed when evaluating the zinc status of populations.
Methods and Options for in vitro Dialyzability; Benefits and Limitations
Authors: Sandberg Ann-Sofie
Published: April 2006

In vitro dialyzability methods involve a two-step digestion process simulating the gastric and intestinal phase, and dialysis through a semi-permeable membrane with a selected molecular weight cut-off. Dialyzable iron/zinc is used as an estimation of available mineral. Final pH adjustment and use of a strict time schedule were found to be critical factors for standardization. In addition the selected cut-off of the dialysis membrane and the method used for iron and zinc determination influence the results. For screening purposes, simple solubility or dialyzability methods seem preferable to the more sophisticated computer-controlled gastrointestinal model. This is likely more valuable in studies of different transit times and sites of dialyzability. In vitro solubility/dialyzability methods correlate in most cases with human absorption studies in ranking iron and zinc availability from different meals. Exceptions may be that effects of milk, certain proteins, tea, and organic acids cannot be predicted. The dialyzability methods exclude iron bound to large molecules, which in some cases is available and include iron bound to small molecules, which is not always available. In vitro experiments based on solubility/dialyzability are tools to understand factors that may affect subsequent mineral absorption.
Methods and Options for Estimating Iron and Zinc Bioavailability Using Caco-2 Cell Models: Benefits and Limitations
Authors: Sharp Paul
Published: April 2006

Micronutrient deficiencies are prevalent worldwide and have detrimental effects on human health. Complex interactions between micronutrients and other dietary components largely determine micronutrient bioavailability, and understanding these interactions is key to improving micronutrient status. A number of in vitro and in vivo methodologies are available for assessing micronutrient bioavailability. The purpose of this review is to highlight the usefulness of one of the in vitro models, the Caco-2 cell, as a predictive tool for human micronutrient bioavailability. The review focuses on current methods used with the Caco-2 cell line, their benefits and limitations, and the possibilities for the future development of this model.
Intelligenzdiagnostik
Authors: Petermann Franz
Published: April 2006

Zusammenfassung. Die Intelligenzdiagnostik bei Kindern besitzt eine über 100-jährige Tradition, die verschiedenartige Testkonzepte hervorbrachte. Wichtige Konzepte werden am Beispiel von Testverfahren, wie dem Hamburg-Wechsler-Intelligenztest für Kinder (HAWIK-IV), der Kaufman Assessment Battery for Children (K-ABC) und dem Snijders-Oomen Non-verbalen Intelligenztest (SON-R 2½ - 7) diskutiert. Auf grundlegende Dimensionen aktueller Intelligenztests wird eingegangen; es zeichnet sich ein Trend zu komplexen Intelligenztest-Verfahren ab.
Kaufman Assessment Battery for Children: Die psychometrischen Eigenschaften des Untertests “Gesichter und Orte“ nach 14 Jahren Anwendung
Authors: Preuss Ulrich
Published: April 2006

Zusammenfassung. Die Kaufman Assessment Battery ist ein Standard Intelligenz- und Fertigkeiten-Testverfahren für Kinder im Vorschul- und Schulalter. Sie gliedert sich in zwei Teile zur Messung intellektueller Fähigkeiten (Skala intellektueller Fähigkeiten SIF) und erworbener Fertigkeiten und Wissen (Fertigkeitenskala FS). Im Fertigkeitenteil wird mit dem Untertest “Gesichter und Orte“ mit Abbildungen von bekannten Gesichtern, Persönlichkeiten und Orten das erworbene Wissen geprüft. Die psychometrischen Eigenschaften des Untertests haben sich verändert. Verschiedene Aufgaben des Tests waren für Kinder aus einer Schweizer Stichprobe schwerer zu lösen. Es werden Vorschläge für alternative Durchführungen gegeben.