bluuebunny/crossref_metadata_2025 huggingface dataset:
Swimming Performance of Brook Trout after Simulated Catch-and-Release Angling: Looking for Air Exposure Thresholds
Authors: Schreer Jason F. , Resch Dayna M. , Gately Malachy L. , Cooke Steven J.
Published: November 2005

Air exposure has been hypothesized as one of the primary stressors present during catch-and-release angling. However, there are few studies that systematically vary air exposure duration and evaluate the consequences on individual fish. Here, we evaluated the short-term, sublethal effects of exercise (to simulate angling) and air exposure on the swimming performance of hatchery brook trout Salvelinus fontinalis at 10°C. The duration of the angling event (i.e., chasing the fish by hand) was held constant at 30 s, while air exposure duration was systematically varied between 0, 30, 60, and 120 s. The results showed that air exposures of 60 s or less did not affect swimming performance. However, air exposure of 120 s resulted in a dramatic (∼75%) reduction in swimming performance. In fact, nearly half of the fish held out of the water for 120 s were unwilling or unable to swim at all. No mortality was observed after any of the treatments (fish were monitored for 3 months). This work suggests that fish possess air exposure thresholds that, once exceeded, result in performance impairments. Fish released after extended air exposure may become easy prey for predators or could be displaced downstream by flows in fluvial environments. We conclude that air exposure should be restricted to less than 60 s and ideally should be avoided entirely.
Development of an In‐Situ Cell for X‐ray Absorption Measurements During Fuel Cell Operation
Authors: Roth C. , Benker N. , Mazurek M. , Scheiba F. , Fuess H.
Published: November 2005

A novel in‐situ cell was designed to allow measurements during real fuel cell operation. Thus, potential and fuel dependent changes in the catalyst structure can be pursued in‐situ. The X‐ray absorption cell was built first in transmission geometry with an inherent graphite beam window, and spectra were recorded at the Pt L3‐edge. This design, however, was not feasible for measurements at the Ru K‐edge due to the strong absorption of Pt in the Pt‐Ru anode catalyst and the low ruthenium content. Therefore, the cell was modified in a second step using either a Be or a Kapton® foil window to allow for fluorescence measurements. The fluorescence set‐up offers the additional advantage that Pt at the anode can be separated from Pt at the cathode side without the need to remove part of the cathode in the beam window region. The optimum set‐up for both the Pt L3‐ and the Ru K‐edge was found to be the cell hardware modified with a Kapton® window in fluorescence geometry. Spectra of different supported and unsupported electrocatalysts were recorded at different potentials at both edges in hydrogen, H2/CO and methanol operation. But only measurements at a carbon‐supported and an unsupported Pt‐Ru catalyst in hydrogen will be presented here. Upon first contact with the fuel, both Pt and Ru (surface) oxides present in the as‐received state are reduced. Potential‐dependent changes, however, are less evident and can be revealed by data fits only.
Thin Film Solar Cells: Materials Science at Interfaces
Authors: Fritsche J. , Klein A. , Jaegermann W.
Published: November 2005

Interfaces are important for the efficiencies of thin film solar cells. In particular for polycrystalline chalcogenide semiconductors as Cu(In,Ga)(S,Se)2 and CdTe the existing physical concepts, which describe the electronic properties of semiconductor interfaces, are not sufficient. The increased complexity is mostly due to the non‐abruptness of the interfaces and the strong tendency for the formation of defects. For the CdTe thin film solar cell a very relevant interface for their operation and efficiency is the CdTe/CdS semiconductor hetero junction. The properties of the semiconductor interfaces have been characterised systematically with photoelectron spectroscopy (XPS/UPS) in integrated ultra high vacuum (UHV) systems for sample preparation and analysis. Withal the key topic is the experimental determination of the band alignment at the semiconductor interfaces. For high efficiency CdTe solar cell production CdCl2 activation is of major importance. The effects of the CdCl2 treatment step on CdTe solar cells had been not completely understood so far. To investigate its influence the activation process has been transferred into the integrated UHV system. We will report about chemical and electronic modifications of the CdTe/CdS hetero interface due to in‐situ CdCl2 activation performing sputter depth profiles in combination with X‐ray photoelectron spectroscopy (XPS).
Synthesis and Properties of Photoisomerizable Derivatives of Isosorbide and Their Use in Cholesteric Filters
Authors: Lub J. , Nijssen W. P. M. , Wegh R. T. , Vogels J. P. A. , Ferrer A.
Published: November 2005

This paper describes the synthesis of photoisomerizable derivatives of isosorbide. These derivatives contain a stilbene or cinnamate moiety and can therefore be used as photoisomerizable chiral compounds in cholesteric liquid‐crystalline mixtures. The reflection wavelength of cholesteric layers made from these mixtures is increased by UV irradiation due to the fact that theZ‐isomers of these derivatives exhibit a lower helical twisting power than the correspondingE‐isomers. The cinnamate derivatives are very suitable for use in cholesteric color filters that find application in liquid‐crystal displays.
Posttranslationale Proteinmodifikation: die Chemie der Proteomdiversifizierung
Authors: Walsh Christopher T. , Garneau‐Tsodikova Sylvie , Gatto Gregory J.
Published: November 2005

Die Vielfalt an kovalenten Proteinvarianten (das Proteom) übersteigt bei weitem die Zahl an Proteinen, die sich aus der Codierkapazität der DNA ableitet. Ursache für diese Diversität sind gerichtete posttranslationale Modifikationen. Unter den Enzymen, die solche Modifikationen ausführen, finden sich etwa 500 humane Proteinkinasen, 150 Proteinphosphatasen und 500 Proteasen. Die Hauptarten der kovalenten Proteinmodifikationen – Phosphorylierung, Acetylierung, Glycosylierung, Methylierung und Ubiquitinierung – können nach der modifizierten Aminosäureseitenkette, dem modifizierenden Enzym und dem Grad an Reversibilität klassifiziert werden. Auch chemische Ereignisse wie das Proteinspleißen, die Reifung des grünen Fluoreszenzproteins und die Selbstaktivierung des Proteasoms zählen zu den posttranslationalen Modifikationen. Ein gründliches Verständnis von Umfang und Muster der posttranslationalen Modifikationen vermittelt Einblicke in die Funktion und Dynamik eukaryotischer Proteomzusammensetzungen.
Enhanced growth in NS0 cells expressing aminoglycoside phosphotransferase is associated with changes in metabolism, productivity, and apoptosis
Authors: Veraitch Farlan S. , Al‐Rubeai Mohamed
Published: November 2005

Prior work has reported that cotransfecting a gene of interest with the selectable marker neo can seriously perturb a number of cellular processes. In this study the influence of the neo gene on the growth, death, and metabolism of a murine myeloma NS0 cell line, expressing a chimeric antibody, was investigated. A pool of neo transfectants, 6A1‐NEO, was selected with 500 µg/mL G418. Quantitative PCR analysis revealed that 6A1‐NEO contained, on average, three copies of the neo gene per cell. Batch cultivation of 6A1‐NEO showed that there was a 36% increase in maximum viable cell concentration, a 20% increase in the maximum apparent growth rate, and a 134% increase in cumulative cell hours as compared with the parent, 6A1‐(100)3. Batch cultivation of five randomly selected clones illustrated that 6A1‐NEO's advantage over the parent was not due to clonal variation. Neither the use of G418 during the selection process nor the cultivation of cells in the presence of G418 were responsible. This implied that the neo gene product, APH(3′)‐II, was causing the changes in proliferative capacity. Analysis of the cell cycle revealed that there were no differences in the distribution of cells in the G1, S, and G2 phases. When cell growth was synchronized, there were no observed differences in cell‐cycle duration. 6A1‐NEO resisted the onset of apoptosis during the growth phase. Consequently, there was a larger viable population of 6A1‐NEO cells available for proliferation as compared with the parent. However, 6A1‐NEO died at the same rate as the parent when resuspended in spent media or after treatment with staurosporin. Expression of the anti‐apoptotic protein Bcl‐2 was upregulated in 6A1‐NEO, indicating that APH(3′)‐II could be acting by modulating endogenous gene expression. Analysis of key metabolites showed that 6A1‐NEO's specific glucose consumption rate was 133% higher, whilst its specific glutamate consumption rate was 45% lower than the parent. 6A1‐NEO's efficient utilization of glutamate and shift towards glucose metabolism may have contributed to the rise in proliferative capacity. However, this was accompanied by a 70% drop in the specific antibody production rate. These results show that the increase in growth rate and proliferative capacity caused by the expression of recombinant APH(3′)‐II was associated with changes in metabolism, apoptosis, and endogenous gene expression. © 2005 Wiley Periodicals, Inc.
Process modeling of in situ‐adsorption of a bacterial lipase
Authors: Millitzer Marcus , Wenzig Edda , Peukert Wolfgang
Published: November 2005

In situ adsorption, known as an in situ‐roduct removal (ISPR) technique for low molecular mass bioproducts, was in this study applied to a bacterial exoenzyme proving that this method is also suitable for the separation of macromolecules like proteins. For this, adsorbent particles were added to growing cultures of Staphylococcus carnosus rec., therefore both production and adsorption occurred simultaneously in shaking flasks, stirred tank, or airlift bioreactor as the chosen types of fermenters. The exoenzyme lipase adsorbed rapidly and, after separating cells and adsorbents, desorbed in a packed bed column. Up to 85% of the produced lipase were recovered, fractions of these had been concentrated up to the factor 20 and purified up to a factor of 40 by the procedure. By using the airlift bioreactor an enhancement of biomass production was observed, but the necessity of the addition of an anti‐foam reagent resulted in higher product losses in adsorption as well as in desorption. Production and adsorption kinetics have been modeled and applied to in situ‐adsorption. The model was used to perform a parameter study in which the influence of biological and physical parameters as well as process parameters on discontinuous and continuous in situ‐adsorption was investigated. © 2005 Wiley Periodicals, Inc.
Potential application of monolith packed columns as bioreactors, control of biofilm formation
Authors: Ebrahimi Sirous , Kleerebezem R. , Kreutzer M.T. , Kapteijn F. , Moulijn J.A. , Heijnen J.J. , van Loosdrecht M.C.M.
Published: November 2005

Monolith reactors combine good mass transfer characteristics with low‐pressure drop, the principle factors affecting the cost effectiveness of industrial processes. Recently, these specific features of the monolith reactors have drawn the attention toward the application of the monolith reactor in multiphase reaction systems. In this study, we explore the potential application of monolith reactors as bioreactor requiring gas–liquid mass transfer for substrate supply. It is demonstrated on theoretical grounds that the monolith reactor is a competitive alternative to conventional gas–liquid bioreactors such as stirred tanks, packed beds, and airlift bioreactors because it allows for a significant reduction of the energy dissipation that is normally required for gas–liquid contacting. A potential problem of monolith reactors for biological processes is clogging due to biofilm formation. This paper presents experimental results of a study into the formation and possible removal of biofilms during operation of a monolith reactor as suspended cells bioreactor. The results indicate that biofilm formation may be minimized and postponed by a proper choice of operating conditions. Periodic biofilm removal could straightforwardly be achieved by rinsing with water at moderate pressures and allows for stable operation for prolonged periods of time. © 2005 Wiley Periodicals, Inc.
Relaxometric Study of Copper [15]Metallacrown‐5 Gadolinium Complexes Derived from α‐Aminohydroxamic Acids
Authors: Parac‐Vogt Tatjana N. , Pacco Antoine , Nockemann Peter , Laurent Sophie , Muller Robert N. , Wickleder Mathias , Meyer Gerd , Vander Elst Luce , Binnemans Koen
Published: November 2005

Proton nuclear magnetic relaxation dispersion (NMRD) profiles were recorded between 0.24 mT and 1.4 T for lanthanum(III)‐ and gadolinium(III)‐containing [15]metallacrown‐5 complexes derived from α‐aminohydroxamic acids and with copper(II) as the ring metal. The influence of the different R‐groups on the proton relaxivity was investigated, and a linear relationship between the relaxivity and the molecular mass of the metallacrown complex was found. The selectivity of the metallacrown complexes was tested by transmetalation experiments with zinc(II) ions. The crystal structure of the copper [15]metallacrown‐5 gadolinium complex with glycine hydroximate ligands is reported.
Aminolysis of 2,4‐Dinitrophenyl X‐Substituted Benzoates and Y‐Substituted Phenyl Benzoates in MeCN: Effect of the Reaction Medium on Rate and Mechanism
Authors: Um Ik‐Hwan , Jeon Sang‐Eun , Seok Jin‐Ah
Published: November 2005

Second‐order rate constants (kN) have been determined spectrophotometrically for the reactions of 2,4‐dinitrophenyl X‐substituted benzoates (1 a–f) and Y‐substituted phenyl benzoates (2 a–h) with a series of alicyclic secondary amines in MeCN at 25.0±0.1 °C. The kN values are only slightly larger in MeCN than in H2O, although the amines studied are approximately 8 pKa units more basic in the aprotic solvent than in H2O. The Yukawa–Tsuno plot for the aminolysis of 1 a–f is linear, indicating that the electronic nature of the substituent X in the nonleaving group does not affect the rate‐determining step (RDS) or reaction mechanism. The Hammett correlation with σ− constants also exhibits good linearity with a large slope (ρY=3.54) for the reactions of 2 a–h with piperidine, implying that the leaving‐group departure occurs at the rate‐determining step. Aminolysis of 2,4‐dinitrophenyl benzoate (1 c) results in a linear Brønsted‐type plot with a βnuc value of 0.40, suggesting that bond formation between the attacking amine and the carbonyl carbon atom of 1 c is little advanced in the transition state (TS). A concerted mechanism is proposed for the aminolysis of 1 a–f in MeCN. The medium change from H2O to MeCN appears to force the reaction to proceed concertedly by decreasing the stability of the zwitterionic tetrahedral intermediate (T±) in aprotic solvent.
(S)‐Selective Kinetic Resolution and Chemoenzymatic Dynamic Kinetic Resolution of Secondary Alcohols
Authors: Borén Linnéa , Martín‐Matute Belén , Xu Yongmei , Córdova Armando , Bäckvall Jan‐E.
Published: November 2005

(S)‐Selective kinetic resolution was achieved through the use of a commercially available protease, which was activated with a combination of two different surfactants. The kinetic resolution (KR) process was optimized with respect to activation of the protease and to the acyl donor. The KR proved to be compatible with a range of functionalized sec‐alcohols, giving good to high enantiomeric ratio values (up to >200). The enzymatic resolution was combined with a ruthenium‐catalyzed racemization to give an (S)‐selective dynamic kinetic resolution (DKR) of sec‐alcohols. The DKR process works under very mild reaction conditions to give the corresponding esters in high yields and with excellent enantioselectivities.
Disposable Gold Electrodes with Reproducible Area Using Recordable CDs and Toner Masks
Authors: Lowinsohn Denise , Richter Eduardo M. , Angnes Lúcio , Bertotti Mauro
Published: November 2005

The fabrication and characterization of very cheap disposable gold disk electrodes with reproducible area is reported. The innovation of the proposed procedure is the use of toner masks to define reproducible areas on uniform gold surfaces obtained from recordable compact disks (CD‐R). Toner masks are drawn in a laser printer and heat transferred to gold surfaces, defining exactly the electrodes area. The electrochemical behavior of these disposable electrodes was investigated by cyclic voltammetry in Fe(CN)64− solutions. The relative standard deviation for signals obtained from 10 different gold electrodes was below 1 %. The size of the disk electrodes can be easily controlled, as attested by voltammetric responses recorded by using electrodes with radii varying from 0.5 to 3.0 mm. The advantages of using this kind of electrode for analytical measurements of substances that strongly adsorb on the electrode surface such as cysteine are also addressed.
Altered expression of thin filament‐associated proteins in hypertrophied urinary bladder smooth muscle
Authors: Mannikarottu Anita S. , DiSanto Michael E. , Zderic Stephen A. , Wein Alan J. , Chacko Samuel
Published: November 2005

Aims

Obstruction of the urinary bladder outlet induces detrusor smooth muscle (DSM) hypertrophy. The goal of this study was to determine whether the composition of thin filament‐associated proteins, known to play important roles in cytoskeletal structure and/or the regulation of contraction, is altered in DSM during hypertrophy.

Methods

DSM hypertrophy was induced in male rabbits by partial ligation of the urethra. Sham‐operated rabbits served as a control. Reverse transcriptase‐polymerase chain reaction (RT‐PCR) and real‐time PCR revealed a significant increase in the expression of mRNAs for basic (h1) calponin (CaP), and α‐isoform of tropomyosin (Tm) in hypertrophied DSM compared to controls. Western blotting and two‐dimensional (2‐D) gel electrophoresis showed enhanced expression of these proteins and also a significant increase in the expression of β‐non muscle and γ‐smooth muscle actin in the DSM from obstructed bladders, while α‐actin remained constant.

Results

Enhanced expression of these proteins in the DSM from obstructed bladders was confirmed by immunofluorescence microscopy. Double immunostaining with Cap/Tm and α/β‐actin‐specific antibodies showed co‐localization of these proteins in myocytes. Colocalization of smooth muscle specific myosin and CaP to cytoplasmic filaments in cells dissociated from the hypertrophied DSM indicated that these cells are differentiated smooth muscle cells.

Conclusions

The change in the isoforms of actin, Cap, and Tm may be part of the molecular mechanism for bladder compensation in increased urethral resistance. Neurourol. Urodynam. © 2005 Wiley‐Liss, Inc.
A combined urodynamic and electrophysiological study of diabetic cystopathy
Authors: Rapidi Christina‐Anastasia , Karandreas Nikos , Katsifotis Charilaos , Benroubi Marianna , Petropoulou Konstantina , Theodorou Charalambos
Published: November 2005

Aims

The aim of this study is to compare urodynamics and electrophysiological studies in the diagnosis of diabetic cystopathy.

Materials and Methods

In this prospective study are included twenty six patients with diabetes mellitus diagnosed at least since 5 years; 17 patients with diabetes type II and 9 with type I. They were divided in two groups in respect to lower urinary tract symptoms (LUTS) and signs suggestive of lower urinary tract dysfunction (LUTD) according to the ICS standardization. Patients with LUTS/LUTD were included in Group A and patients without LUTS/LUTD in Group B. Patients underwent different studies: urodynamic, somatosensory evoked potentials (SSEP) of tibial and pudendal nerves, bulbocavernosus reflex (BCR), bulbocavernosus muscles' electromyography and motor evoked potentials after transcranial magnetic stimulation to indirectly investigate bladder's innervation.

Results

Abnormal urodynamics were found in 13 patients of group A (92.9%) and in 5 of group B (47.1%). This difference was statistically significant (P = 0.009). Abnormally prolonged latency of P40 of tibial SSEP was found in 11 patients of group A (78.6%) and in 4 of group B (33.3%) and this difference was also statistically significant (P = 0.04). Differences between the two groups concerning: i) peripheral polyneuropathy; ii) pudendal SSEP, iii) dysfunction of central nervous system and iv) abnormal BCR were not statistically significant.

Conclusion

The study of tibial SSEP is an easily performed test and it is well correlated to abnormal urodynamics in diabetic patients with and without LUTD/LUTS. Neurourol. Urodynam. © 2005 Wiley‐Liss, Inc.
A non‐linear programming approach to kinematic shakedown analysis of composite materials
Authors: Li H. X. , Yu H. S.
Published: November 2005

Using a Representative volume element (RVE) to represent the microstructure of periodic composite materials, this paper develops a non‐linear numerical technique to calculate the macroscopic shakedown domains of composites subjected to cyclic loads. The shakedown analysis is performed using homogenization theory and the displacement‐based finite element method. With the aid of homogenization theory, the classical kinematic shakedown theorem is generalized to incorporate the microstructure of composites. Using an associated flow rule, the plastic dissipation power for an ellipsoid yield criterion is expressed in terms of the kinematically admissible velocity. By means of non‐linear mathematical programming techniques, a finite element formulation of kinematic shakedown analysis is then developed leading to a non‐linear mathematical programming problem subject to only a small number of equality constraints. The objective function corresponds to the plastic dissipation power which is to be minimized and an upper bound to the shakedown load of a composite is then obtained. An effective, direct iterative algorithm is proposed to solve the non‐linear programming problem. The effectiveness and efficiency of the proposed numerical method have been validated by several numerical examples. This can serve as a useful numerical tool for developing engineering design methods involving composite materials. Copyright © 2005 John Wiley & Sons, Ltd.
Fracture toughness of polymers in the ductile‐to‐brittle transition region: Statistical approach and lower bound determination
Authors: Cocco R. G. , Frontini P. M. , Perez Ipiña J. E.
Published: November 2005

A method available in literature was adapted and proposed for treating scatter and nonlinearity effects in fracture toughness of polymers in the ductile‐to‐brittle transition regime. The materials used were polypropylene homopolymer (PPH) and a polypropylene‐elastomeric polyolefin blend (PPH/POes 20 wt %), at room temperature and at 20‐mm/min test rate. Under such conditions, the fracture toughness presents a large scatter and a mean value can not be used as a design parameter because it leads to toughness overestimation. Then, there is a need to find a threshold of toughness, as a safe characteristic value for design. The toughness was evaluated by using the J‐integral approach. Large sets of specimens, 53 samples per each material, were tested with the purpose to reveal a reliable tendency in fracture behavior. As the toughness was considered nonuniform throughout the material, a weakest link model was assumed, and then results were analyzed statistically by means of a three‐parameter Weibull model (3P‐W). The PPH responded well to this 3P‐W model, whereas some deviations from the original model were observed in the PPH/POes blend. However, lower‐bound toughness values could be determined for both materials by censoring nonvalid data (Δa > 0.1b0). From an engineering point of view, the results are very encouraging, since this methodology allows to obtain a threshold of fracture toughness from a given population, that is suitable to characterize the material fracture toughness at a given temperature and strain rate. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3674–3684, 2005
Interaction of doxorubicin and idarubicin with red blood cells from acute myeloid leukaemia patients
Authors: Marczak Agnieszka , Kowalczyk Aleksandra , Wrzesień‐Kus´ Agata , Robak Tadeusz , Jóźwiak Zofia
Published: November 2005

Doxorubicin (DOX) and idarubicin (IDA) are anthracycline antibiotics, widely used in human cancer treatment. The present study addressed the effects of these two drugs on lipid bilayer fluidity, protein conformation and microviscosity in erythrocytes from acute myeloid leukaemia patients, using electron spin resonance (ESR) spectroscopy and fluorescence measurements. Only DOX caused statistically significant changes in the parameters examined. Within 30 min of drug injection, changes were observed in the fluidity of the hydrophobic parts of the lipid bilayer and erythrocyte membrane protein conformation. These changes persisted for up to 24 h. Analysis of the EPR Tempamine spectrum also showed that the microviscosity of the erythrocyte interior increased during the early stages of the drug effect. Idarubicin, in contrast, caused no identifiable change in any of the parameters studied and therefore seems to be safe for erythrocytes. We conclude that IDA is markedly less toxic than DOX to erythrocytes from acute myeloid leukaemia patients.
Activity of Pichia pastoris alternative cis‐prenyltransferase is correlated with proliferation of peroxisomes
Authors: Skoneczny Marek , Kludkiewicz Barbara , Swiezewska Ewa , Szkopinska Anna
Published: November 2005

We have investigated dolichol synthesis in yeast Pichia pastoris. Growth of these cells on methanol causes peroxisome proliferation and induction of peroxisomal enzymes. Twenty‐four hours methanol treatment was sufficient for the appearance of longer‐chain dolichols. Less specific oleic acid induction needed 48 h for the synthesis of longer dolichol family with typical one still present. Cells cultured in non‐inducing conditions for 48 h did not reveal the presence of additional dolichol family. Peroxisomes purified from oleic acid treated cells synthesize in vitro polyprenols longer by two isoprene residues than those synthesized by microsomal fraction from glucose culture. These observations lead us to suggest that chain length of dolichols synthesized in yeast cell may depend on the carbon and energy source supply which mobilizes metabolic pathways localized to different cellular compartments.
Epigenetic and classical activation of Entamoeba histolytica heat shock protein 100 (EHsp100) expression
Authors: Bernes Sabina , Siman-Tov Rama , Ankri Serge
Published: November 2005

The protozoan parasite Entamoeba histolytica expresses a cytosine‐5 DNA methyltransferase (Ehmeth) that belongs to the DNMT2 protein family. The biological function of members of this DNMT2 family is unknown. In the present study, the 5′ region of E. histolytica heat shock protein 100 (5′EHsp100) was isolated by affinity chromatography with 5‐methylcytosine antibodies as ligand. The methylation status of 5′EHsp100 was confirmed by sodium bisulfite sequencing. We showed that the expression of EHsp100 was induced by heat shock, 5‐azacytidine (5‐AzaC), an inhibitor of DNA methyltransferase and Trichostatin A (TSA), an inhibitor of histone deacetylase. The effect of TSA on EHsp100 expression was rapidly reversed by removing the drug from the culture. In contrast, EHsp100 expression was still detectable one month after removing 5‐AzaC from the media. Whereas 5‐AzaC and TSA caused demethylation in the promoter region of EHsp100, no demethylation was observed following heat shock. Remarkably, DNA that includes three putative heat shock elements identified in the promoter region of EHsp100 bound to a protein of 37 kDa present in the nuclear fraction of heat‐shocked trophozoites but absent in the nuclear fraction of 5‐AzaC and TSA treated trophozoites. Our data suggest that EHsp100 expression can be regulated by both a classical and an epigenetic mechanism.
Analysis of expression of growth factor receptors in replicatively and oxidatively senescent human fibroblasts
Authors: Chen Jian-Hua , Ozanne Susan E. , Hales C. Nicholas
Published: November 2005

Replicatively and oxidatively senescent human fibroblasts demonstrate an impaired response to mitogens. To investigate whether this is due to downregulation of growth factor receptors we examined their expression in these two types of senescence. mRNA and protein levels of the insulin receptor and platelet‐derived growth factor (PDGF) α‐receptor decreased in replicatively senescent cells. The PDGF β‐receptor and insulin‐like growth factor 1 receptor at the protein level also decreased but remained readily detectable. However, these major growth factor receptors remained unchanged in oxidatively premature senescent cells. This suggests that mechanisms underlying diminished responsiveness to mitogens might be different in replicative senescence and oxidatively premature senescence.
High cholesterol diet induces tau hyperphosphorylation in apolipoprotein E deficient mice
Authors: Rahman Atiqur , Akterin Susanne , Flores-Morales Amilcar , Crisby Milita , Kivipelto Miia , Schultzberg Marianne , Cedazo-Mínguez Angel
Published: November 2005

We analysed the effects of high cholesterol (HC) intake and reduced apolipoprotein E (apoE) activity on tau phosphorylation and on the activities of the major tau kinases and phosphatases in brains from wild‐type and apoE‐knockout (apoEKO) mice. We show that HC diet potently induced intraneuronal accumulation of hyperphosphorylated tau in apoEKO mice, as well as upregulation of several tau kinases, without affecting tau phosphatases. Our results suggest an interaction between dietary and genetic factors in the development of tauopathies, which can be relevant in humans, where the apoE4 isoform could have a lack of function as compared to other isoforms.
Ha‐Ras sensitizes transformed mouse skin cells to Anisomycin‐induced apoptosis
Authors: Santibañez Juan F. , Hurtado Claudia
Published: November 2005

Efforts have been made to develop a chemoprevention that selectively triggers apoptosis in malignant cancer cells. Here, we demonstrated that a mutated Ha‐Ras activity is required in Anisomycin‐induced apoptosis in transformed keratinocytes. Anisomycin stimulates JNK activity and apoptosis in oncogenic Ha‐Ras positive cells, but not in normal keratinocytes. This effect was demonstrated in stably transfected cells with dominant negative Ha‐Ras, that protected transformed cells, and oncogenic Ha‐Ras that sensitized non‐transformed cells to Anisomycin‐induced apoptosis. Lastly, the treatment of cells with inhibitors of the JNK displayed resistance to Anisomycin induced apoptosis. These data suggests that the oncogenic Ha‐Ras is important for Anisomycin‐induced JNK activation and apoptosis in transformed keratinocytes.
Regulation of vascular smooth muscle cell proliferation, migration and death by heparan sulfate 6‐O‐endosulfatase1
Authors: Sala-Newby Graciela B. , George Sarah J. , Bond Mark , Dhoot Gurtej K. , Newby Andrew C.
Published: November 2005

Migration, proliferation and death of vascular smooth muscle cells (VSMC) are important events in vascular pathology regulated by heparan sulfate proteoglycans and hence potentially by cell surface HS 6‐O‐endosulfatase1 (sulf1). Sulf1 mRNA expression was increased in cultured VSMC compared to rat aorta. Furthermore, adenovirus mediated overexpression of quail sulf1 decreased adhesion, and increased proliferation and apoptosis of VSMC. Overexpression of a dominant negative variant also decreased adhesion of VSMC and increased proliferation, apoptosis, migration and chemotaxis of VSMC. Our results imply that only normal levels of 6‐O‐sulfation maintained by sulf1 are optimal for several functions of VSMC.
Current challenges in quantitative modeling of epidermal growth factor signaling
Authors: Breitling Rainer , Hoeller Daniela
Published: November 2005

Over the last decade, epidermal growth factor (EGF) signaling has been used repeatedly as a testbed for pioneering computational systems biology. Recent breakthroughs in our molecular understanding of EGF signaling pose new challenges for mathematical modeling strategies. Three key areas emerge as particularly relevant: the pervasive importance of compartmentalization and endosomal trafficking; the complexity of signalosome complexes; and the regulatory influence of diffusion and spatiality. Each one of them demands a drastic change in current computational approaches. We discuss recent developments in the field that address these emerging aspects in a new generation of more realistic – and potential more useful – models of EGF signaling.
Identification of voltage‐dependent Ca2+ channels in sea urchin sperm
Authors: Granados-Gonzalez G. , Mendoza-Lujambio I. , Rodriguez E. , Galindo B.E. , Beltrán C. , Darszon A.
Published: November 2005

Functional evidence indicates that voltage‐dependent Ca2+ (Cav) channels participate in sea urchin sperm motility and the acrosome reaction (AR), however, their molecular identity remains unknown. We have identified transcripts for two Ca2+ channel α1 subunits in sea urchin testis similar in sequence to Cav1.2 and Cav2.3. Antibodies against rat Cav1.2 and Cav2.3 channels differentially label proteins in the flagella and acrosome of mature sea urchin sperm. The Cav channel antagonists nifedipine and nimodipine, which inhibit the AR, diminish the intracellular Ca2+ elevation induced by a K+‐induced depolarization in valinomycin‐treated sperm. These findings reveal that Cav1.2 and Cav2.3 channels could participate in motility and/or the AR in sea urchin sperm.
An ABC transporter mediating the membrane detachment of bacterial lipoproteins depending on their sorting signals
Authors: Narita Shin-ichiro , Tokuda Hajime
Published: November 2005

Bacterial lipoproteins are anchored to membranes through a lipid moiety attached to the N‐terminal Cys. Escherichia coli possesses more than 90 species of lipoproteins, most of which are localized in the outer membrane and others in the inner membrane. Sorting of lipoproteins to the outer membrane requires the Lol system comprising five Lol proteins. An ATP‐binding cassette transporter, LolCDE, initiates the lipoprotein sorting by mediating the detachment of outer membrane‐specific lipoproteins from the inner membrane. LolCDE does not recognize lipoproteins possessing Asp at position 2, which therefore remain anchored to the inner membrane. We will discuss the mechanism of LolCDE based on data obtained through in vitro experiments.
RFX‐1, a putative alpha Adducin interacting protein in a human kidney library
Authors: Boito Rosalia , Menniti Miranda , Amato Rosario , Palmieri Camillo , Marinaro Cinzia , Iuliano Rodolfo , Tripodi Grazia , Cusi Daniele , Fuiano Giorgio , Perrotti Nicola
Published: November 2005

Adducin regulates tubular absorption of sodium by modulating the expression levels of the sodium–potassium‐ATPase in renal tubular cells. Adducin is a candidate gene in the pathogenesis of hypertension. Yeast two hybrid screen showed a specific interaction between human alpha Adducin and the regulatory factor for X box (RFX‐1), a nuclear protein that down regulates the expression of several proteins in non neuronal cells. The interaction was confirmed in cells through coimmunoprecipitation and colocalization experiments. The binding of alpha Adducin to RFX‐I and their nuclear co‐localization suggests that Adducin can have a role in modulating the transcriptional regulating activity of RFX‐I.
Impaired ATP‐binding cassette transporter A1‐mediated sterol efflux from oxidized LDL‐loaded macrophages
Authors: Favari Elda , Zimetti Francesca , Bortnick Anna E. , Adorni Maria Pia , Zanotti Ilaria , Canavesi Monica , Bernini Franco
Published: November 2005

We investigated the interaction of oxidized low density lipoprotein (OxLDL) with the ATP‐binding cassette A1 (ABCA1) pathway in J774 macrophages. Cellular efflux to apolipoprotein AI (apo‐AI) of OxLDL‐derived cholesterol was lower than efflux of cholesterol derived from acetylated low density lipoprotein (AcLDL). ABCA1 upregulation by 8‐(4‐chlorophenylthio)adenosine 3′:5′‐cyclic monophosphate (cpt‐cAMP) or 22 (R)‐hydroxycholesterol (22‐OH) and 9‐cis retinoic acid (9cRA) increased the efflux to apo‐AI of cellular sterols derived from AcLDL, but not of those from OxLDL. AcLDL, but not OxLDL, induced ABCA1 protein content and activity in J774. However, OxLDL did not influence J774 ABCA1 upregulation by cpt‐cAMP or 22‐OH/9cRA. We conclude that sterols released to cells by OxLDL are available neither as substrate nor as modulator of ABCA1.
A major ozonation product of cholesterol, 3β‐hydroxy‐5‐oxo‐5,6‐secocholestan‐6‐al, induces apoptosis in H9c2 cardiomyoblasts
Authors: Sathishkumar K. , Haque Masudul , Perumal Thirugnanam E. , Francis Joseph , Uppu Rao M.
Published: November 2005

Cholesterol, a major neutral lipid component of biological membranes and the lung epithelial lining fluids, is susceptible to oxidation by reactive oxygen and nitrogen species including ozone. The oxidation by ozone in biological environments results in the formation of 3β‐hydroxy‐5‐oxo‐5,6‐secocholestan‐6‐al (cholesterol secoaldehyde or CSeco, major product) along with some other minor products. Recently, CSeco has been implicated in the pathogenesis of atherosclerosis and Alzheimer's disease. In this communication, we report that CSeco induces cytotoxicity in H9c2 cardiomyoblasts with an IC50 of 8.9 ± 1.29 μM (n
= 6). The observed effect of CSeco at low micromolar concentrations retained several key features of apoptosis, such as changes in nuclear morphology, phosphatidylserine externalization, DNA fragmentation, and caspase 3/7 activity. Treatment of cardiomyocytes with 5 μM CSeco for 24 h, for instance, resulted in 30.8 ± 3.28% apoptotic and 1.8 ± 1.11% of necrotic cells as against DMSO controls that only showed 1.3 ± 0.33% of apoptosis and 1.6 ± 0.67% of necrosis. In general, the loss of cellular viability paralleled the increased occurrence of apoptotic cells in various CSeco treatments. This study, for the first time, demonstrates the induction of apoptotic cell death in cardiomyocytes by a cholesterol ozonation product, implying a role for ozone in myocardial injury.
Comparative genomic hybridization analysis of spontaneous abortion
Authors: Hu Yali , Chen Xue , Chen Lei Lei , Xu Zheng Feng , Wang XihRu , Cui Hengmi
Published: November 2005

Objectives

To evaluate the feasibility and superiority of comparative genomic hybridization (CGH) in the genetic analysis of spontaneously aborted tissues.

Methods

38 conceptuses from early failed pregnancies were studied, of which, 27 samples were fresh and 11 were old. Each sample was divided into two parts, one part for conventional cytogenetic analysis and the other for CGH analysis.

Results

All 38 spontaneously aborted tissues were analyzed successfully by the CGH approach, but only 31 samples received results from the cytogenetic karyotype analysis, while 7 other tissues failed to get data due to failure in tissue culturing. Among the specimen successfully analyzed by both approaches, 90% (28 out of 31) obtained identical results, and 14 aneuploidies were found. The only structural chromosome aberration in this series, 46, XY, del(3) (q22–24), was found using the CGH approach, which appeared as a normal male karyotype on the chromosomal metaphase spread. Also, two cases indicated triploidies under cytogenetic analysis but appeared to be normal on the CGH profile. In addition, among the seven samples of tissue culture failure, CGH identified three to be aneuploidies.

Conclusion

The CGH analysis accurately identifies chromosomal unbalanced abnormalities related to spontaneous abortions with low failure rate.
The attitudes of two groups of South African women towards mode of delivery
Authors: Manthata A.L.A. , Hall D.R. , Steyn P.S. , Grové D.
Published: November 2005

Objective

To determine whether 2 specific groups of women prefer vaginal or abdominal delivery.

Methods

Forty‐six black and 54 colored (of mixed race, the predominant population group) primigravidas and 59 black and 62 colored multigravidas were interviewed between April 2003 and February 2004 at Tygerberg Hospital, Tygerberg, South Africa.

Results

Among primigravidas, 89% of black women and 83% of colored women preferred vaginal delivery. Among the multigravidas, 86% of black women and 79% of colored women preferred vaginal delivery. Most women believed that they would recover more quickly (65%) and with less pain (32%) after vaginal delivery. Forty‐one percent of all women viewed episiotomy as the greatest disadvantage of vaginal delivery, while 43% were unaware of any advantage to cesarean delivery.

Conclusion

Most colored and black women preferred vaginal over cesarean delivery. A challenge to healthcare personnel is to educate women about both routes.
Scaphoid Non-Union: The Role of Vascularized Grafting In Recalcitrant Non-Unions of the Scaphoid
Authors: TAMBE A. D. , CUTLER L. , STILWELL J. , MURALI S. R. , TRAIL I. A. , STANLEY J. K.
Published: November 2005

Achieving union using conventional grafts has a high chance of failure in patients with recalcitrant non-union (persistent pseudarthrosis) of the scaphoid bone, an avascular proximal fragment and previous failed surgeries because of poor host bed vascularity. Eleven patients with long-standing non-union were treated with vascularized pedicle bone grafting and supplementary corticocancellous grafting. Five had screw fixation and six were fixed with K-wires. The average age of the patients was 28 years, average duration of the non-union was 39 months and mean radiological follow-up was 32 months. There were no significant skeletal complications, although two patients developed neuromata. At review, only six of the 11 non-unions were united. Whilst this is a difficult clinical problem and achieving union is a formidable challenge, we believe that there is a role for such extensive surgery in order to achieve good postoperative function.
Provenance, age, and environment of mid-wisconsinan slackwater lake sediment in the St. Louis Metro East Area, USA
Authors: Curry B. Brandon , Grimley David A.
Published: November 2005

Valleys tributary to the Mississippi River contain fossiliferous slackwater lake sediment (Equality Formation) deposited in response to aggradation of the Mississippi River valley during the last glaciation. In the St. Louis Metro East area, the lower part of the Equality Formation is primarily laminated, fossiliferous silt and clay deposited from about 44,150 to 24,310 14C yr B.P. The upper Equality Formation is primarily very fine sand to silt deposited from about 21,200 to 17,000 14C yr B.P. Among the four cores that sample this succession in the St. Louis Metro East area, core MNK-3 (38.64EN, 90.01EW) was selected for detailed study. Three sources are distinguished by the following characteristics: (1) gray smectite-quartz-Se-rich, feldspar-poor material of the Des Moines, Wadena, and James lobes; (2) reddish brown kaolinite–Cu–Fe-rich sediment of the Superior and Rainy lobes; and (3) brown illite–dolomite–Sr-rich sediment of the Lake Michigan and Green Bay lobes. The earliest sediments (44,150 to 41,700 14C yr B.P.) were derived from the central and western provenances and are chronocorrelative with the lower Roxana Silt. A hiatus occurred from about 41,700 to 29,030 14C yr B.P. when much of the middle Roxana Silt (Meadow Member) was deposited on adjacent uplands. The youngest sediment includes evidence of heightened activity of the Superior Lobe at about 29,000 14C yr B.P., the Lake Michigan and Green Bay lobes from about 25,000 to 24,000 14C yr B.P., and the Wadena-Des Moines-James lobes at about 21,000 14C yr B.P.
First Place—Resident Clinical Science Award 1997: Germline screening of the NF‐2 gene in families with unilateral vestibular schwannoma
Authors: Bikhazi Paul H. , Lalwani Anil K. , Kim Eugene J. , Bikhazi Nadim , Attaie Ali , Slattery William H. , Jackler Robert K. , Brackmann Derald E.
Published: November 2005

Vestibular schwannoma may present clinically in two forms: sporadic unilateral or hereditary bilateral. Familial transmission of vestibular schwannoma is known to occur only in neurofibromatosis type II (NF‐2). We have previously described the clinical characteristics of unilateral vestibular schwannoma presenting in families, in the absence of ther criteria necessary for the diagnosis of NF‐2. Polymerase chain reaction–single strand chain polymorphism was used to screen for germline NF‐2 gene mutations in six families with unilateral vestibular schwannoma. Direct sequencing of DNA from blood was done in affected subjects from three families. No germline mutations were identified. Because NF‐2 gene mutations are detected in only 33% of patients with NF‐2, hereditary transmission of mutations cannot be entirely excluded. However, in the absence of germline mutations in the NF‐2 gene, familial occurrence of unilateral vestibular schwannoma more likely represents either a chance somatic NF‐2 gene mutation or originates from a separate genetic loci. (Otolaryngol Head Neck Surg 1998;119:1–6.)
Vestibular compensation revisited
Authors: Vidal Pierre‐Paul , Waele Catherine De , Vibert Nicolas , Mühlethaler Michel
Published: November 2005

Vestibular compensation for the static and dynamic disorders induced by unilateral labyrinthectomy is a good model of plasticity in the central nervous system. After the lesion, the static deficits generally disappear in a few days, whereas recuperation of the dynamic, vestibular‐related synergies is much slower and merely partial. The goal of this article is to reexamine some aspects of vestibular compensation in light of several recent findings. In the first part, we show that in vertebrates the organization of the neural networks underlying vestibular reflexes is deeply linked with the skeletal geometry of the animals. Accordingly, we propose that the neuronal mechanisms underlying vestibular compensation might be plane specific. We then deal with several issues related to the exact timing of vestibular compensation in various species. In the second part, we give several examples showing that vestibular compensation can now be studied at the molecular and cellular levels. For instance, we summarize some of our recent data, which indicate that glial cells could be strongly involved in the compensation process. (Otolaryngol Head Neck Surg 1998;119:34–42.)
Short‐term vestibulo‐ocular adaptation: Influence of context
Authors: Kramer Phillip , Shelhamer Mark , Zee David S.
Published: November 2005

A number of mechanisms and strategies are used to help an individual compensate for loss of labyrinthine function. One important example is the ability to produce a preplanned motor response that anticipates the motion of the head and so compensates for it. Closely tied to this phenomenon is the gating, in or out, of a learned response on the basis of the context in which it must occur. This issue is particularly relevant to designing programs of physical therapy that optimize performance for natural behavior. Here we discuss a model of short‐term vestibulo‐ocular adaptation—adjustment of vestibulo‐ocular phase (timing)—and how it can be used to study context‐dependent vestibulo‐ocular learning. We will show how vestibulo‐ocular phase can be adjusted by selectively altering the common velocity‐to‐position ocular motor neural integrator for one type of eye movement (vestibular) and not for another (saccades), or for one type of head movement (sinusoidal) and not for another (step). These results are another example of the remarkable flexibility of the vestibulo‐ocular adaptive mechanism and further show that the fundamental process of integration for eye movements can be modified according to the pattern of afferent information. (Otolaryngol Head Neck Surg 1998; 119:60‐4.)