bluuebunny/crossref_metadata_2025 huggingface dataset:
Lactic acid based PEU/HA and PEU/BCP composites: Dynamic mechanical characterization of hydrolysis
Authors: Rich Jaana , Tuominen Jukka , Kylmä Janne , Seppälä Jukka , Nazhat Showan N. , Tanner K. Elizabeth
Published: August 2002

Lactic acid based poly(ester‐urethane) (PEU‐BDI) and its composites with 20 and 40 vol.% bioceramic filler were characterized prior to their use as biocompatible and bioabsorbable artificial bone materials. Morphological, dynamic mechanical properties, and degradation of these either hydroxyapatite or biphasic calcium phosphate containing composites were determined. Addition of particulate bioactive filler increased the composite stiffness and the glass transition temperature, indicating strong interactions between the filler and matrix. Materials were sterilized by γ‐irradiation, which reduced the average molecular weights by 30–40%. However, dynamic mechanical properties were not significantly affected by irradiation. Specimens were immersed in 0.85 w/v saline at 37 °C for 5 weeks, and changes in molecular weights, mass, water absorption, and dynamic mechanical properties were recorded. All the composite materials showed promising dynamic mechanical performance over the 5 weeks of hydrolysis. Average molecular weights of PEU‐BDI and its composites did not change substantially during the test period. PEU‐BDI retained its modulus values relatively well, and although the moduli of the composite materials were much higher, especially at high filler content, they exhibited faster loss of mechanical integrity. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 346–353, 2002
Measuring the elastic properties of fine wire
Authors: Fallen C.T. , Costello J. , Crawford G. , Schmidt J.A.
Published: August 2002

The elastic moduli of fine wires made from MP35N and 304SS used in implantable biomedical devices are assumed to be the same as those published in the literature. However, the cold working required to manufacture the wire significantly alters the elastic moduli of the material. We describe three experiments performed on fine wire made from MP35N and 304SS. The experimentally determined Young's and shear modulus of both wire types were significantly less than the moduli reported in the literature. Young's modulus differed by as much as 26%, and the shear modulus differed by as much as 14% from reported values.
Biocompatible microcapsules with enhanced mechanical strength
Authors: Chang Shwu Jen , Lee Chen Hsen , Hsu Chun Yuan , Wang Yng Jiin
Published: August 2002

A block copolymer, (short‐chain alginate)‐co‐MPEG, was synthesized and used for coating the capsular membranes of the photosensitive microcapsules. The resulted microcapsules exhibited an excellent mechanical strength. The permeability test results revealed that the capsular membrane was freely permeable to cytochrome C and myoglobin, less permeable to serum albumin, and almost impermeable to IgG. In the cell attachment test, the results showed that the surface formed by (short‐chain alginate)‐co‐MPEG copolymer could effectively reduce cell adhesion as compared to poly(L‐lysine) and alginate. The microcapsules were evaluated by intraperitoneal implantation experiment of mice. The results demonstrated that microcapsules coated with (short‐chain alginate)‐co‐MPEG were more biocompatible than the conventional alginate/PLL/alginate microcapsules. © 2001 Wiley Periodicals, Inc. J Biomed Mater Res 59: 118–126, 2002
Lack of requirement of STAT1 for activation of nuclear factor‐κB, c‐Jun NH2‐terminal protein kinase, and apoptosis by tumor necrosis factor‐α
Authors: Mukhopadhyay Asok , Shishodia Shishir , Fu Xin‐Yuan , Aggarwal Bharat B.
Published: August 2002

Tumor necrosis factor (TNF) is one of the most potent activators of nuclear transcription factor NF‐κB, c‐Jun N‐terminal protein kinase (JNK), and apoptosis in a wide variety of cells. The biological effects of TNF are mediated through sequential interactions of various cytoplasmic proteins with intracellular domains of TNF receptors. Whether signal transducer and activator of transcription‐1 (STAT1), which mediates interferon (IFN) signaling, also plays any role in the TNF‐mediated activation of NF‐κB, JNK, and apoptosis has not been established. Here, we report our investigation of the role of STAT1 in TNF signaling using STAT1‐deficient U3A and STAT1‐stably transfected U3A‐PSG91 cells. IFNα inhibited the proliferation of STAT1‐expressing U3A‐PSG91 cells but had no effect on STAT1‐negative U3A cells. TNF alone, even up to 10 nM, had no effect on the proliferation of either U3A‐PSG91 or U3A cells. Irrespective of STAT1 status, TNF induced cytotoxic effects in the presence of cycloheximide (CHX) in both cell types. Additionally, TNF‐induced caspase‐3 and caspase‐8 activation and TNF‐induced PARP cleavage were unaffected by the presence or absence of STAT1. TNF activated NF‐κB, consisting of p50 and p65, in both U3A and U3A‐pSG91 cells in a dose‐ and time‐dependent manner, but the degree and rate of activation were slightly lower in U3A cells, as were IκBα degradation and NF‐κB‐dependent reporter gene expression. STAT1 was, however, required for IFNα‐mediated downregulation of TNF‐induced NF‐κB activation. TNF activated JNK in both cell types, but dose and time of exposure required for optimum activation differed slightly. Thus, overall our results indicate that STAT1 plays a minimal role in TNF‐mediated cellular responses. J. Cell. Biochem. 84: 803–815, 2002. © 2002 Wiley‐Liss, Inc.
Chromatin and histones from Giardia lamblia: A new puzzle in primitive eukaryotes
Authors: Triana Omar , Galanti Norbel , Olea Nancy , Hellman Ulf , Wernstedt Christer , Lujan Hugo , Medina Carlos , Toro G. Cecilia
Published: August 2002

The three deepest eukaryote lineages in small subunit ribosomal RNA phylogenies are the amitochondriate Microsporidia, Metamonada, and Parabasalia. They are followed by either the Euglenozoa (e.g., Euglena and Trypanosoma) or the Percolozoa as the first mitochondria‐containing eukaryotes. Considering the great divergence of histone proteins in protozoa we have extended our studies of histones from Trypanosomes (Trypanosoma cruzi, Crithidia fasciculata and Leishmania mexicana) to the Metamonada Giardia lamblia, since Giardia is thought to be one of the most primitive eukaryotes. In the present work, the structure of G. lamblia chromatin and the histone content of the soluble chromatin were investigated and compared with that of higher eukaryotes, represented by calf thymus. The chromatin is present as nucleosome filaments which resemble the calf thymus array in that they show a more regular arrangement than those described for Trypanosoma. SDS‐polyacrylamide gel electrophoresis and protein characterization revealed that the four core histones described in Giardia are in the same range of divergence with the histones from other lower eukaryotes. In addition, G. lamblia presented an H1 histone with electrophoretic mobility resembling the H1 of higher eukaryotes, in spite of the fact that H1 has a different molecular mass in calf thymus. Giardia also presents a basic protein which was identified as an HU‐like DNA‐binding protein usually present in eubacteria, indicating a chimaeric composition for the DNA‐binding protein set in this species. Finally, the phylogenetic analysis of selected core histone protein sequences place Giardia divergence before Trypanosoma, despite the fact that Trypanosoma branch shows an acceleration in the evolutionary rate pointing to an unusual evolutionary behavior in this lineage. J. Cell. Biochem. 82: 573–582, 2001. © 2001 Wiley‐Liss, Inc.
Molecular and cellular mechanisms of adipose secretion: Comparison of leptin and angiotensinogen
Authors: Turban S. , Hainault I. , André J. , Ferré P. , Quignard‐Boulangé A. , Guerre‐Millo M.
Published: August 2002

Besides their function of lipid storage, the adipose cells secrete a number of proteins of physiopathological importance. To get further insights into this function, which remains poorly characterized, we sought to compare the mechanisms and regulation of secretion of two individual proteins in the same cells. Leptin and angiotensinogen were chosen and assessed by radioimmunoassay and quantitative immunoblotting, respectively, in primary culture of epididymal adipose cells from young obese Zucker rats. Leptin was secreted at a steady rate of 4 ng/106 cells/h over 2–6 h. Despite secretion, leptin cellular content remained stable at 3 ng/106 cells. In contrast, the rate of angiotensinogen secretion decreased regularly from 45 arbitrary units/106 cells/h at 2 h, to half this value at 6 h, although cell content remained constant at 100 arbitrary units/106 cells. Inhibition of protein synthesis by cycloheximide depleted the cells from leptin, but not from angiotensinogen for up to 6 h. Insulin increased leptin secretion (+75%) and cell content (+70 %), without affecting angiotensinogen. Secretion of both proteins was inhibited by Golgi‐disturbing agents, brefeldin A and monensin. The presence of brefeldin A led to a specific rise in leptin cell content, an effect inhibited by cycloheximide and enhanced by insulin (+80%). These data show that leptin and angiotensinogen are both secreted through Golgi‐dependent pathways and that their respective intracellular pool exhibit distinct turn‐over rate and insulin sensitivity. These characteristics might account for the differential response of these adipose proteins to variations in the systemic environment. J. Cell. Biochem. 82: 666–673, 2001. © 2001 Wiley‐Liss, Inc.
Stimulatory effect of lactate on testosterone production by rat Leydig cells
Authors: Lin Ho , Wang Shyi‐Wu , Wang Ray‐Yau , Wang Paulus S.
Published: August 2002

Previously we found that the increased plasma testosterone levels in male rats during exercise partially resulted from a direct and luteinizing hormone (LH)‐independent stimulatory effect of lactate on the secretion of testosterone. In the present study, the acute and direct effects of lactate on testosterone production by rat Leydig cells were investigated. Leydig cells from rats were purified by Percoll density gradient centrifugation subsequent to enzymatic isolation of testicular interstitial cells. Purified rat Leydig cells (1 × 105 cells/ml) were in vitro incubated with human chorionic gonadotropin (hCG, 0.05 IU/ml), forskolin (an adenylyl cyclase activator, 10−5 M), or 8‐bromo‐adenosine‐3′:5′‐cyclic monophosphate (8‐Br‐cAMP, 10−4 M), SQ22536 (an adenylyl cyclase inhibitor, 10−6–10−5 M), steroidogenic precursors (25‐hydroxy‐cholesterol, pregnenolone, progesterone, and androstenedione, 10−5 M each), nifedipine (a L‐type Ca2+ channel blocker, 10−5–10−4 M), or nimodipine (a potent L‐type Ca2+ channel antagonist, 10−5–10−4 M) in the presence or absence of lactate at 34°C for 1 h. The concentration of medium testosterone was measured by radioimmunoassay. Administration of lactate at 5–20 mM dose‐dependently increased the basal testosterone production by 63–187% but did not alter forskolin‐ and 8‐Br‐cAMP‐stimulated testosterone release in rat Leydig cells. Lactate at 10 mM enhanced the stimulation of testosterone production induced by 25‐hydroxy‐cholesterol in rat Leydig cells but not other steroidogenic precursors. Lactate (10 mM) affected neither 30‐ nor 60‐min expressions of cytochrome P450 side chain cleavage enzyme (P450scc) and steroidogenic acute regulatory (StAR) protein. The lactate‐stimulated testosterone production was decreased by administration of nifedipine or nimodipine. These results suggested that the physiological level of lactate stimulated testosterone production in rat Leydig cells through a mechanism involving the increased activities of adenylyl cyclase, cytochrome P450scc, and L‐type Ca2+ channel. J. Cell. Biochem. 83: 147–154, 2001. © 2001 Wiley‐Liss, Inc.
α1‐adrenergic stimulation mediates Ca2+‐dependent inositol phosphate formation through the α1B‐like adrenoceptor subtype in adult rat cardiac myocytes
Authors: Seraskeris Stelios , Lazou Antigone
Published: August 2002

We studied the effects of increased Ca2+ influx on α1‐adrenoceptor‐stimulated InsP formation in adult rat cardiac myocytes. We further examined if such effects could be mediated through a specific α1‐adrenoceptor subtype. [3H]InsP responses to adrenaline were dependent on extracellular Ca2+ concentration, from 0.1 μM to 2 mM, and were completely blocked by Ca2+ removal. However, in cardiac myocytes preloaded with BAPTA, a highly selective calcium chelating agent, Ca2+ concentrations higher than 1 μM had no effect on adrenaline‐stimulated [3H]InsP formation. Taken together these results suggest that [3H]InsP formation induced by α1‐adrenergic stimulation is in part mediated by increased Ca2+ influx. Consistent with this, ionomycin, a calcium ionophore, stimulated [3H]InsP formation. This response was additive with the response to adrenaline stimulation implying that different signaling mechanisms may be involved. In cardiac myocytes treated with the α1B‐adrenoceptor alkylating agent, CEC, [3H]InsP formation remained unaffected by increased Ca2+ concentrations, a pattern similar to that observed when intracellular Ca2+ was chelated with BAPTA. In contrast, addition of the α1A‐subtype antagonist, 5′‐methyl urapidil, did not affect the Ca2+ dependence of [3H]InsP formation. Neither nifedipine, a voltage‐dependent Ca2+ channel blocker nor the inorganic Ca2+ channel blockers, Ni2+ and Co2+, had any effect on adrenaline stimulated [3H]InsP, at concentrations that inhibit Ca2+ channels. The results suggest that in adult rat cardiac myocytes, in addition to G protein‐mediated response, α1‐adrenergic‐stimulated [3H]InsP formation is activated by increased Ca2+ influx mediated by the α1B‐subtype. J. Cell. Biochem. 84: 201–210, 2002. © 2001 Wiley‐Liss, Inc.
Growth factor‐mediated altered expression and regulation of S‐adenosylmethionine decarboxylase in a H‐ras transformed cell line capable of malignant progression
Authors: Hardin Marcus S. , Hurta Robert A. R.
Published: August 2002

Mammalian S‐adenosylmethionine decarboxylase (SAMDC) is a regulatory activity, which is involved in the biosynthesis of polyamines. The polyamines, namely putrescine, spermidine, and spermine, are essential for mammalian cell proliferation. SAMDC expression was examined in a H‐ras transformed cell capable of metastasis formation. Serum stimulation of these cells resulted in increased SAMDC mRNA and enzyme activity expression. The effect of several physiologically relevant growth factors on SAMDC expression was also determined. SAMDC mRNA expression was increased in response to epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) stimulation but was unaffected by transforming growth factor beta1 (TGF‐beta1) and platelet derived growth factor (PDGF). Increased SAMDC enzyme activity occurred in response to exposure to EGF, bFGF, TGF‐beta1, and PDGF. The EGF and bFGF mediated alterations in SAMDC mRNA expression were apparently not due to alterations in the transcriptional apparatus but occurred partly through post‐transcriptional mechanisms involving increased SAMDC message stability. EGF and bFGF were able both to cooperate with cycloheximide, an inhibitor of protein synthesis, to augment the expression of SAMDC mRNA. Furthermore, studies with NIH‐3T3 fibroblasts transfected with either the normal basic fibroblast growth factor coding sequence that lacks a known secretory signal sequence or a chimeric bFGF sequence that targets the growth factor to the secretory pathway revealed that increased SAMDC expression occurred only in those cells which contained the chimeric bFGF sequence that targets the growth factor to the secretory pathway suggesting that the increase in expression of SAMDC occurs through an autocrine mechanism. Increased ornithine decarboxylase (ODC) expression was found to occur in both types of bFGF transfected cells suggesting that altered ODC expression in response to bFGF stimulation may occur through both autocrine and intracrine mechanisms. In addition, a correlation was found to exist between SAMDC expression and regulation in response to growth factor stimulation and malignant potential. This correlation supports the view that growth factor induced alterations in SAMDC expression, although not sufficient on their own to induce metastasis, are important in the promotion and establishment of events important to the phenotype expressed by H‐ras transformed cells capable of malignant progression. J. Cell. Biochem. 84: 349–358, 2002. © 2001 Wiley‐Liss, Inc.
Oligovalent link atoms in embedding calculations
Authors: Krüger Thomas , Sax Alexander F.
Published: August 2002

Making reasonable statements about large systems is a notoriously difficult task of quantum chemistry. If such a system consists of a small but electronically important region, the core, which requires a treatment on a high level of theory, and a larger remainder, the bulk, which only acts in a perturbative fashion and thus admits a description on a lower level of theory, then it is appropriate to partition it accordingly and use an embedding scheme to provide for the coupling of the two regions. In many cases of said partitioning it will be necessary to cut covalent bonds so that the emerging free valences have to be saturated by link atoms. Mostly hydrogen atoms are used. However, it may be necessary to separate the entire system so that bulk atoms are generated that are bound to two or three core atoms at once, that is, such bulk atoms are divalent or even trivalent with respect to the core. In the present article we demonstrate by means of several silane molecules, ranging from Si3H8 to Si104H92, that the use of oligovalent link atoms is quite promising. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 371–377, 2002
Comprehensive relativistic ab initio and density functional theory studies on PtH, PtF, PtCl, and Pt(NH3)2Cl2
Authors: Liu Wenjian , Franke Robert
Published: August 2002

Platinum monohydride is taken as an example to compare the performance of various relativistic and correlation approaches, such as all‐electron DPT (direct perturbation theory), ECP (effective core potential); RSPT2, RSPT3 (second‐ and third‐order multireference Rayleigh–Schrödinger perturbation theory), CCSD(T) (coupled‐cluster with singles, doubles, and perturbative triples), as well as the four‐component relativistic density functional theory. It is shown that first‐order DPT performs significantly better than the (first‐order) Breit–Pauli Hamiltonian. The performance of different approaches for the excitation energies of the platinum diatomics is discussed critically. The molecular spectroscopic constants for PtF and PtCl are predicted for the first time. The geometric data for several isomers of cis‐ and trans‐Pt(NH3)2Cl2 are reported. The corresponding energetic data are calculated at relativistic all‐electron and ECP‐CCSD(T) as well as four‐component relativistic density functional levels of theory. Contrary to previous results, it is found that the two C2v isomers of cis‐Pt(NH3)2Cl2 are marginally separated in energy, which could be ascribed to Cl—H interactions. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 564–575, 2002; DOI 10.1002/jcc.10030
The SGB/NP hydration free energy model based on the surface generalized born solvent reaction field and novel nonpolar hydration free energy estimators
Authors: Gallicchio Emilio , Zhang Linda Yu , Levy Ronald M.
Published: August 2002

The development and parameterization of a solvent potential of mean force designed to reproduce the hydration thermodynamics of small molecules and macromolecules aimed toward applications in conformation prediction and ligand binding free energy prediction is presented. The model, named SGB/NP, is based on a parameterization of the Surface Generalized Born continuum dielectric electrostatic model using explicit solvent free energy perturbation calculations and a newly developed nonpolar hydration free energy estimator motivated by the results of explicit solvent simulations of the thermodynamics of hydration of hydrocarbons. The nonpolar model contains, in addition to the more commonly used solvent accessible surface area term, a component corresponding to the attractive solute–solvent interactions. This term is found to be important to improve the accuracy of the model, particularly for cyclic and hydrogen bonding compounds. The model is parameterized against the experimental hydration free energies of a set of small organic molecules. The model reproduces the experimental hydration free energies of small organic molecules with an accuracy comparable or superior to similar models employing more computationally demanding estimators and/or a more extensive set of parameters. © 2002 Wiley Periodicals, Inc. J Comput Chem 5: 517–529, 2002; DOI 10.1002/jcc.10045
Ab initio study on the photochemical behavior of styrene
Authors: Amatatsu Yoshiaki
Published: August 2002

Ab initio complete active space self‐consistent field (CASSCF) and the second order multireference Møller‐Plesset calculations have been performed to examine the photochemical behavior of styrene upon the strong S0‐S2 electronic excitation in the low‐lying excited states. The optimized structure at the S2/S1 conical intersection (CIX) is characterized by a quinoid structure. The transition state (TS) in S1 is in the vicinity of the S2/S1‐CIX. At the S1‐TS, two reaction paths branch. One is the relaxation into the stable structure in S1 and then emission into S0. The other is the radiationless decay through the S1/S0‐CIX. © 2002 Wiley Periodicals, Inc. J Comput Chem 10: 950–956, 2002
Molecular mechanics calculations on carbonyl compounds. IV. Heats of formation
Authors: Langley Charles H. , Lii Jenn‐Huei , Allinger Norman L.
Published: August 2002

Molecular mechanics (MM4) calculations on the heats of formation of aldehydes and ketones were carried out for a total of 59 compounds (10 aldehydes and 49 ketones). Optimization of the heat of formation parameters was obtained by a least squares fit to the experimentally known heats of formation. With the optimized MM4 heat of formation parameters, the MM4 calculated heats of formation showed significant improvement over those of MM3. The standard and weighted root mean square deviations for the MM4 values were 0.35 and 0.31 kcal mol−1, respectively, whereas for the MM3 values they were 0.42 and 0.39 kcal mol−1, respectively. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1476–1483, 2001
Ability of fullerenes to act as η6 ligands in transition metal complexes. A comparative PM3(tm)–density functional theory study
Authors: Goh Sor‐Koon , Marynick Dennis S.
Published: August 2002

High‐quality DFT calculations are employed to estimate the arene exchange energies for reactions of general formula:

For C60 and C70 complexes of Cr(CO)3, full geometry optimizations at the DFT level using moderately large basis sets were performed, while for the other systems a hybrid approach was developed in which the geometries were obtained at the PM3(tm) level and the energetics were evaluated at the DFT level. C70 is shown to be a slightly better arene ligand than C60; however, no enhancements of arene‐like bonding capabilities are seen for C78 and C84 relative to C70. Explicit calculation of a series of exchange energies at the DFT level using both DFT and PM3(tm) geometries demonstrates that PM3(tm) geometries are sufficiently accurate for the calculation of energetics at a higher theoretical level, but PM3(tm) calculations are inadequate for a quantitative assessment of exchange energies. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1881–1886, 2001
Theoretical study on reaction mechanism of the CF radical with nitrogen dioxide
Authors: Tao Yu‐guo , Ding Yi‐hong , Liu Jian‐jun , Li Ze‐sheng , Huang Xu‐ri , Sun Chia‐Chung
Published: August 2002

The singlet potential energy surface of the [CFNO2] system is investigated at the B3LYP and CCSD(T) (single‐point) levels to explore the possible reaction mechanism of CF radical with NO2. The top attack of C‐atom of CF radical at the N‐atom of NO2 molecule first forms the adduct isomer FCNO2 1 followed by oxygen‐shift to give trans‐OC(F)NO 2 and then to cis‐OC(F)NO 3. Subsequently, the most favorable channel is a direct dissociation of 2 and 3 to product P1 FCO+NO. The second and third less favorable channels are direct dissociation of 3 to product P2 FNO+CO and isomerization of 3 to a complex NOFCO 4, which can easily dissociate to product P3 FON+CO, respectively. The large exothermicity released in these processes further drives most of the three products P1, P2, and P3 to take secondary dissociation to the final product P12 F+CO+NO. Another energetically allowed channel is formation of product P4 1NF+CO2, yet it is much less competitive than P1, P2, P3, and P12. The present calculations can well interpret one recent experimental fact that the title reaction is quite fast yet still much slower than the analogous reaction CH+NO2. Also, the results presented in this article may be useful for future product distribution analysis of the title reaction as well as for the analogous CCl and CBr reactions. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1907–1919, 2001
Current status of doctoral‐level training in psychological testing
Authors: Belter Ronald W. , Piotrowski Chris
Published: August 2002

Training directors of 82 American Psychological Association (APA)‐approved doctoral programs in clinical psychology responded to a survey on the current status and recent changes in doctoral training in psychological assessment. Although testing continues to be a major focus of training, a slight decline in emphasis on assessment was noted, most notably with projective techniques. With few exceptions (e.g., NEO‐PI, Personality Assessment Inventory), traditional tests were emphasized in coursework and also were considered “essential” for the practicing psychologist. Interestingly, there seems to be increased emphasis on the interview and neuropsychological testing compared to prior surveys of academic settings. Only 29% of the training directors reported that their programs have been significantly affected by managed care, suggesting that most academic programs are somewhat insulated from marketplace pressures. It is recommended that training programs balance their focus on traditional academic values with the realities of the clinical practice arena. © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 717–726, 2001.
Feelings in context: Countertransference and the real world in feminist therapy
Authors: Brown Laura S.
Published: August 2002

The concept of countertransference has been seen as problematic by feminist therapists. However, feminist therapy theory is intensely interested in the symbolic levels of the relationships between therapists and clients, with an emphasis on how the here and now social context informs and transforms those symbols. This article describes a feminist perspective on the therapist's symbolic relationships to clients, and the positive and challenging ramifications of those symbolic encounters. © 2001 John Wiley & Sons, Inc. J Clin Psychol/In Session 57: 1005–1012, 2001.
Toward an integrative perspective on resistance to change
Authors: Arkowitz Hal
Published: August 2002

This article presents an integrative perspective on resistance. The phenomena of resistance can be seen at the behavioral, interpersonal, cognitive, and affective levels. A set of integrative working assumptions is proposed in which resistance reflects meaningful information about clients' conflicts among various aspects of their selves relating to change. In this view, resistance is determined by intrapersonal and interpersonal factors and can occur with or without conscious awareness. Integrative approaches to working with these conflicts are described. © 2002 John Wiley & Sons, Inc. J Clin Psychol/In Session 58: 219–227, 2002.
Effects of calcium, calmodulin, protein kinase C and protein tyrosine kinases on volume‐activated taurine efflux in human erythroleukemia cells
Authors: Huang Chiun‐Chien , Chang Chirn‐Bin , Liu Jer‐Yuh , Basavappa Srisaila , Lim Poh‐Hong
Published: August 2002

The effects of calcium, calmodulin, protein kinase C (PKC) and protein tyrosine kinase (PTK) modulators were examined on the volume‐activated taurine efflux in the erythroleukemia cell line K562. Exposure to hypoosmotic solution significantly increased taurine efflux and intracellular calcium concentration ([Ca2+]i). The Ca2+ channel blockers La3+ (1 mM), verapamil (200 μM) and nifedipine (100 μM) inhibited the hypoosmotically‐induced [Ca2+]i increase by more than 90%, while the volume‐activated taurine efflux was inhibited by 61.3 ± 9.5, 74.1 ± 9.3 and 38.0 ± 1.5%, respectively. Furthermore, the calmodulin inhibitors W7 (50 μM) and trifluoperazine (10 μM) and the Ca2+/calmodulin‐dependent protein kinase II inhibitor KN‐62 (2 μM) significantly blocked the volume‐activated taurine efflux by 93.4 ± 2.7, 77.9 ± 3.5 and 61.3 ± 15.8%, respectively. In contrast, the PKC inhibitor staurosporine (200 nM) or the PKC activator phorbol 12‐myristate 13‐acetate (100 nM) did not have significant effects on the volume‐activated taurine efflux. However, pretreatment with PTK inhibitors genistein, tyrphostin A25, and tyrphostin A47 blocked the volume‐activated taurine efflux. These results suggest that the volume‐activated taurine efflux in K562 cells may not directly involve Ca2+, but may require the presence of calmodulin and/or PTK. © 2001 Wiley‐Liss, Inc.
Quantitative analysis of agonist‐dependent parathyroid hormone receptor trafficking in whole cells using a functional green fluorescent protein conjugate
Authors: Conway Bruce R. , Minor Lisa K. , Xu Jun Z. , D'Andrea Michael R. , Ghosh Richik N. , Demarest Keith T.
Published: August 2002

Many G‐protein coupled receptors (GPCRs) undergo ligand‐dependent internalization upon activation. The parathyroid hormone (PTH) receptor undergoes endocytosis following prolonged exposure to ligand although the ultimate fate of the receptor following internalization is largely unknown. To investigate compartmentalization of the PTH receptor, we have established a stable cell line expressing a PTH receptor–green fluorescent protein (PTHR–GFP) conjugate and an algorithm to quantify PTH receptor internalization. HEK 293 cells expressing the PTHR–GFP were compared with cells expressing the wild‐type PTH receptor in whole‐cell binding and functional assays. 125I‐PTH binding studies revealed similar Bmax and kD values in cells expressing either the PTHR–GFP or the wild‐type PTH receptor. PTH‐induced cAMP accumulation was similar in both cell lines suggesting that addition of the GFP to the cytoplasmic tail of the PTH receptor does not alter the ligand binding or G‐protein coupling properties of the receptor. Using confocal fluorescence microscopy, we demonstrated that PTH treatment of cells expressing the PTHR–GFP conjugate produced a time‐dependent redistribution of the receptor to the endosomal compartment which was blocked by pretreatment with PTH antagonist peptides. Treatment with hypertonic sucrose prevented PTH‐induced receptor internalization, suggesting that the PTH receptor internalizes via a clathrin‐dependent mechanism. Moreover, co‐localization with internalized transferrin showed that PTHR–GFP trafficking utilized the endocytic recycling compartment. Experiments using cycloheximide to inhibit protein synthesis demonstrated that recycling of the PTHR–GFP back to the plasma membrane was complete within 1–2 h of ligand removal and was partially blocked by pretreatment with cytochalasin D, but not nocodazole. We also demonstrated that the PTH receptor, upon recycling to the plasma membrane, is capable of undergoing a second round of internalization, a finding consistent with a role for receptor recycling in functional resensitization. © 2001 Wiley‐Liss, Inc.
Use of various processes for pilot plant treatment of wastewater from a wood‐processing factory
Authors: Athanasopoulos Nikolaos S
Published: August 2002

The wastewater from a wood‐processing factory is characterized by a high COD, chlorides and nitrogen content. Various treatment processes were applied to treat this wastewater in pilot‐scale units. By applying one‐stage denitrification–activated sludge biological treatment it was not possible to remove nitrogen. Nitrification was inhibited by wastewater compounds. By applying a second stage of a nitrification biofilter it was possible to have a high degree of nitrification. The denitrification was complete. With biological methods the reduction of COD, and ${\bf NO_{3}^{-}}$‐N and ${\bf NH_{4}^{+}}$‐N concentrations to acceptable values was not achievable. Physical–Chemical methods as H2O2/UV, electrolysis and ozonation were used as post‐treatment of effluents from the biological system. Radical degradation, initiated by the powerful hydroxyl radicals which are generated from H2O2 by UV activation, is used for wastewater post‐treatment. The combination of H2O2/UV was not suitable for post‐treatment of this wastewater. With electrolysis, ${\bf NH_{4}^{+}}$‐N and COD removal can be complete. The total amount of ammonia and organic nitrogen converted to nitrate nitrogen for current density of 1.15 Adm−2 and energy consumption of 71.6 kWhm−3 was 0.35 gdm−3. Further biological denitrification is required for ${\bf NO_{3}^{-}}$‐N removal to permitted values. Energy consumption for the elimination of 1 kg COD was 40.4 kWh and 35.8 kWh for current densities of 0.7 Adm−2 and 1.15 Adm−2 respectively. The energy required to reach the limit value of COD equal to 150 mgdm−3 for current density of 1.15 Adm−2 was 71.6 kWhm−3. With ozonation, the COD removal can be complete. Further biological nitrification–denitrification is required to remove ${\bf NH_{4}^{+}}$‐N and ${\bf NO_{3}^{-}}$‐N to permitted values. At pH 7.0, in order to reach the limit value of COD equal to 150 mgdm−3, specific ozone dose was 6.0 g per g of COD removed and the total amount of ammonia and organic nitrogen converted to nitrate nitrogen was 0.25 gdm−3. The total equivalent energy required is estimated to be 75.0 kWhm−3.

© 2001 Society of Chemical Industry
Sensitivity analysis in oxidation ditch modelling: the effect of variations in stoichiometric, kinetic and operating parameters on the performance indices
Authors: Abusam A , Keesman K J , van Straten G , Spanjers H , Meinema K
Published: August 2002

This paper demonstrates the application of the factorial sensitivity analysis methodology in studying the influence of variations in stoichiometric, kinetic and operating parameters on the performance indices of an oxidation ditch simulation model (benchmark). Factorial sensitivity analysis investigates the sensitivities in a region rather than in a point. Hence, it has the advantage of giving more information about parameter interactions (non‐linearity). Short‐term results obtained have shown the following. The index AE is not significantly affected by variations in the value of parameters of the activated sludge model (ASM) No 1. The index TSP is greatly influence by heterotrophic yield (YH), heterotrophic decay (bH) and specific hydrolysis (kh) and the index EQ is dominated by YH, Monod coefficient (KS), bH, kh, anoxic condition correction factors (ηg, ηh), hydrolysis half‐saturation coefficient (KX), autotrophs maximum specific growth rate (µA) and ammonia half‐saturation coefficient (KNH). Furthermore, the index EQ has been shown to be very sensitive to parameter interactions, at certain regions.

© 2001 Society of Chemical Industry
Experimentation of a new mode of batch culture for lactic acid bacteria: cell reuse with an initial period of cell reactivation at acidic pH
Authors: Amrane Abdeltif
Published: August 2002

Cell reuse was compared with conventional batch culture for lactic acid fermentation, the objective was to simplify the batch process and to alleviate the need for added nitrogen. At high levels of nitrogen supplementation to the culture medium (20 g dm−3 yeast extract and 5 g dm−3 each of tryptic and pancreatic casein peptones), similar mean production rates were obtained with partial cell reuse and the conventional batch process, without any additional gain when cells were initially reactivated at acidic pH. On the other hand, cell reuse with an initial period without pH control appeared particularly effective for low levels of nitrogen supplementation (5 g dm−3 yeast extract): a 57% increase in the mean production rate with regard to the conventional batch process was obtained.

© 2001 Society of Chemical Industry
A Coming of 'Phage: Bacteriophages in Biotechnology
Authors: Sharp Richard J , Hambleton Peter
Published: August 2002

Copyright © 2001 Society of Chemical Industry
Combined chemical (ozone) and biological treatment of polychlorinated biphenyls (PCBs) adsorbed to sediments
Authors: Cassidy Daniel , Hampton Duane , Kohler Steven
Published: August 2002

Laboratory experiments were conducted to test the feasibility of ozone sparging to oxidize PCBs in sediments, and to determine the organic acid content and biodegradability of the oxidation products. Two PCBs were tested; 2‐,2′‐dichlorobiphenyl (DCB) and 2‐,3‐,4‐,2′‐,3′‐,4′‐hexachlorobiphenyl (HCB). DCB and HCB were allowed to adsorb onto solids in slurries of pure kaolinite and river sediments containing 2% native organic matter (NOM). Ozone was sparged through the slurries while concentrations of PCBs and Cl−, and chemical oxygen demand (COD) were measured with time. Gas chromatography/mass spectrometry (GC/MS) was used to identify the organic acids produced from the reaction of ozone with DCB and HCB. After sparging, the liquid was placed in bioreactors with inoculum from a domestic wastewater treatment plant and nutrients. Ozone sparging in the kaolinite slurries removed 94% of HCB and 97% of DCB in 30 days. In contrast, 55 days were required to achieve the same PCB removal in river sediment slurries. Ozone doses per g of DCB and HCB in kaolinite were 19 g and 30 g, respectively. Doses were 13–14 times greater in river sediments. Formic and oxalic acids were ozonation products of both PCBs. Specific ozonation products of DCB and HCB were 2‐hydroxybenzoic acid and 2,3,4‐trihydroxybenzoic acid, respectively. The results show that ozone caused ring cleavage of PCBs and stoichiometric replacement of Cl with OH groups. Over 93% of the soluble COD from ozone sparging was biodegraded within 20–26 days in the bioreactors.

© 2002 Society of Chemical Industry
Gene expression in the supraoptic nucleus
Authors: Ueta Yoichi , Levy Andrew , Lightman Stafford L.
Published: August 2002

The magnocellular neurosecretory cells (MNCs) in the supraoptic nucleus (SON) express multiple kinds of genes, including not only the classical hormones arginine vasopressin (AVP) and oxytocin (OXT), but also other physiologically active substances including neuropeptides, their receptors, and nitric oxide (NO) synthase, the rate‐limiting enzyme in the synthesis of NO under physiological condition. For example, osmotic stimuli such as dehydration and chronic salt loading cause a wide range of changes of the expression levels of the genes and marked induction of the expression of the genes in the SON. The expression of the NO synthase gene in the SON under physiological conditions is reviewed. Microsc. Res. Tech. 56:158–163, 2002. © 2002 Wiley‐Liss, Inc.
Application of immunoelectron microscopy techniques in the diagnosis of phytoplasma diseases
Authors: Musetti Rita , Loi Nazia , Carraro Luigi , Ermacora Paolo
Published: August 2002

An immunoelectron microscopy technique was applied to label Chrysanthemum leuchanthemum phytoplasma in infected leaf tissues of Chrysanthemum leuchanthemum L. and Catharanthus roseus L. plants. Specific monoclonal antibodies at different dilutions and secondary antimouse antibody conjugated with colloidal gold particles of different sizes were used. The monoclonal antibodies demonstrated their specificity against the antigen; immunocytological methods permitted the precise localization and identification of phytoplasmas in thin sections from infected tissues. Microsc. Res. Tech. 56:462–464, 2002. © 2002 Wiley‐Liss, Inc.
Unraveling the enigma: The role of melatonin in seasonal processes in birds
Authors: Bentley George E.
Published: August 2002

Birds, unlike mammals, do not use the annual profile of pineal melatonin secretion to coordinate their reproductive efforts with a favorable time of year. Melatonin in birds mediates the entrainment of circadian activity rhythms, and thus helps to time hatching of eggs and facilitate migration. However, the role of melatonin as a reliable indicator of day length for seasonal processes has remained equivocal for many years. Recently, the influence of melatonin on two physiological processes involved in aspects of seasonal reproduction has been identified in European starlings: 1) the regulation of seasonal changes in immune function, and 2) neuroplasticity in the song control system. Melatonin can enhance cell‐mediated immune function and acts as an inhibitory hormone on the song control system. Melatonin receptor (MelR) density in a forebrain song control nucleus, Area X, is regulated as a function of reproductive state; there is marked downregulation of MelR in Area X during the breeding season in starlings. Seasonal regulation of immune function and neural plasticity within the song control system, and the efficacy of the action of melatonin on these two processes, appears to be modified by the same central, thyroid‐dependent mechanism that controls the reproductive state of birds. These data indicate that the interaction of day length and hormones of different classes affects the ability of melatonin to affect seasonal processes in birds. The downstream consequences of MelR regulation within the song control system are discussed with regard to the cellular action of melatonin and its possible interaction with immediate‐early genes and transcription factors. Microsc. Res. Tech. 53:63–71, 2001. © 2001 Wiley‐Liss, Inc.
Cholinergic‐nitrergic transmitter mechanisms in the cerebral circulation
Authors: Lee Tony J.F. , Liu Jie , Evans M. Steven
Published: August 2002

Cerebral blood vessels from several species are innervated by vasodilator nerves. Acetylcholine (ACh) released from parasympathetic cholinergic nerves was first suggested to be the transmitter for vasodilation. Results from pharmacological studies in isolated cerebral arterial ring preparations, however, have demonstrated that nitric oxide (NO) but not ACh mediates the major component of neurogenic vasodilation. More recently, ACh and NO have been shown to co‐release from the same cholinergic‐nitrergic nerves, and that ACh acts as a presynaptic transmitter in modulating NO release. In this communication, evidence for the neuronal origin of NO and possible role of ACh in modulating NO release in large cerebral arteries at the base of the brain will be discussed. Microsc. Res. Tech. 53:119–128, 2001. © 2001 Wiley‐Liss, Inc.
Physiology of meningeal innervation: Aspects and consequences of chemosensitivity of meningeal nociceptors
Authors: Ebersberger Andrea
Published: August 2002

Up to now, the cause of most types of headaches is unknown. Why headache starts or why it fades away during hours or a few days is still a mystery. This phenomenon makes headache unique compared to other pain states. For long it has been known that during headache sensory structures in the meninges are activated. But it was not until the last two decades that scientists investigated the physiology of the sensory innervation of the meninges. Animal models and in vitro preparations have been developed to get access to the meninges and to determine the response properties of meningeal afferents. Although animals hardly can tell their pain, blood pressure measurements and observations of behaviour in two models of headache suggest that such animal models are valid and may add remarkable information to our understanding of human headache. Since chemicals and endogenous inflammatory mediators may alter sensory thresholds and responsiveness of neurons, they are putative key molecules in triggering pathophysiological sensory processing. This review briefly summarizes what is known about the chemosensitivity of meningeal innervation. Microsc. Res. Tech. 53:138–146, 2001. © 2001 Wiley‐Liss, Inc.
Neurogenic inflammation in the context of migraine
Authors: Williamson David J. , Hargreaves Richard J.
Published: August 2002

Despite considerable research into the pathogenesis of idiopathic headaches, such as migraine, the pathophysiological mechanisms underlying them remain poorly understood. Although it is well established that the trigeminal nerve becomes activated during migraine, the consequences of this activation remain controversial. One theory, based on preclinical observations, is that activation of trigeminal sensory fibers leads to a painful neurogenic inflammation within the meningeal (dural) vasculature mediated by neuropeptide release from trigeminal sensory fibres and characterized by plasma protein extravasation, vasodilation, and mast cell degranulation. Effective antimigraine agents such as ergots, triptans, opioids, and valproate inhibit preclinical neurogenic dural extravasation, suggesting that this activity may be a predictor of potential clinical efficacy of novel agents. However, several clinical trials with other agents that inhibit this process preclinically have failed to show efficacy in the acute treatment of migraine in man. Alternatively, it has been proposed that painful neurogenic vasodilation of meningeal blood vessels could be a key component of the inflammatory process during migraine headache. This view is supported by the observation that jugular plasma levels of the potent vasodilator, calcitonin gene‐related peptide (CGRP) are elevated during the headache and normalized by successful sumatriptan treatment. Preclinically, activation of trigeminal sensory fibers evokes a CGRP‐mediated neurogenic dural vasodilation, which is blocked by dihydroergotamine, triptans, and opioids but unaffected by NK1 receptor antagonists that failed in clinical trials. These observations suggest that CGRP release with associated neurogenic dural vasodilation may be important in the generation of migraine pain, a theory that would ultimately be tested by the clinical testing of a CGRP receptor antagonist. Microsc. Res. Tech. 53:167–178, 2001. © 2001 Wiley‐Liss, Inc.
GDNF improves cerebellar Purkinje neuron function in aged F344 rats
Authors: Bickford P.C. , Bowenkamp K. , Taglialatela G. , Hoertig G. , Granholm A.‐C.
Published: August 2002

Aging is associated with a decline in the function of β‐adrenergic receptor responses in the cerebellum. This decline in noradrenergic receptor sensitivity may underlie some of the accompanying age‐related declines in motoric learning behaviors. Glial cell line–derived neurotrophic factor (GDNF) has been reported to prevent the degeneration of noradrenergic neurons following neurotoxic lesions. Thus, it was of interest to examine if GDNF would have a beneficial effect on age‐related declines in noradrenergic function. Eighteen‐month‐old F344 rats were injected with 500 μg GDNF in 20 μl into the cisterna magna. Three weeks following GDNF or vehicle treatment, rats were tested on a motor coordination task and then examined electrophysiologically under urethane anesthesia. GDNF did not produce an improvement in performance on an inclined balance beam or an accelerating rotorod. In young (3‐month‐old) F344 rats isoproterenol (ISO) will increase GABAergic inhibitions in the majority of cells examined; however, in aged rats only about 30% of neurons demonstrate this phenotype. In the aged rats treated with GDNF, ISO was able to increase GABAergic inhibitions in greater than 75% of the neurons tested, thus returning the neurons to a young phenotype. We examined the brains for expression of bcl‐2, which has been shown to be increased in the aged cerebellum. GDNF was able to down‐regulate this neuronal signal. Thus, intra‐cisterna magna delivery of GDNF to aged rats improved β‐adrenergic receptor function and reduced stress related signaling of bcl‐2 in the aged F344 rats to a level similar to that observed in young rats. Microsc. Res. Tech. 54:309–316, 2001. © 2001 Wiley‐Liss, Inc.