bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biocompatibility of fluorinated polyimide
Authors: Kanno M. , Kawakami H. , Nagaoka S. , Kubota S. 
Published: August 2002

AbstractContact between blood and biomaterial triggers a complex series of events including protein adsorption, leukocyte adhesion and activation, and complement activation. In this article, a series of fluorinated polyimides cured at a different temperatures was prepared, and the biocompatibility of the membranes was evaluated using in vitro protein adsorption, neutrophil adhesion, and complement activation experiments under static conditions. We found that protein adsorption, neutrophil adhesion, and complement activation for the polyimides significantly depends on the curing temperature and decreases with an increase in the temperature and that the polyimide has a good biocompatibility compared with poly(styrene) and polydimethylsiloxane. We concluded that the rearrangement of molecules such as CF3, sulfone, and ketone at the outermost surface occurs because of curing, which induces an increase in the hydrophobicity and that the cured polyimide suppresses protein adsorption, neutrophil adhesion, and complement activation because of its high hydrophobicity and low surface free energy. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res, 60, 53–60, 2002.
Phorbol diester 12‐O‐tetradecanoylphorbol 13‐acetate (TPA) up‐regulates the expression of estrogen receptors in human THP‐1 leukemia cells
Authors: Cutolo Maurizio , Carruba Giuseppe , Villaggio Barbara , Coviello Domenico A. , Dayer Jean‐Michel , Campisi Ildegarda , Miele Monica , Stefano Rosalba , Castagnetta Luigi A.M. 
Published: August 2002

AbstractIn the present work, we have inspected expression of estrogen receptors (ER) and their regulation by the phorbol diester 12‐O‐tetradecanoylphorbol 13‐acetate (TPA) in a leukemic cell line, the THP‐1 cells, using multiple experimental approaches. Firstly, ligand binding assay (LBA) revealed that control (unstimulated) THP‐1 cells express type I (high affinity, limited capacity) ER in the nuclear fraction only, whilst treatment of cells with TPA resulted in the appearance of type I ER in the soluble fraction as well, with the 50 ng/ml dose and the 48 h incubation time being the most effective experimental condition. A concomitant increase of type II ER was also seen in both soluble and nuclear cell fractions. Unstimulated THP‐1 cells were found to be ER negative by immunocytochemistry; conversely, cells exposed to 50 ng/ml TPA for 48 h stained positively for ER, with the majority of cells having a strong nuclear staining. Scrutiny of ER mRNA expression using reverse transcriptase‐polymerase chain reaction showed the presence of a wild type ER transcript in both control and TPA‐treated THP‐1 cells, though levels of ER mRNA were found to be comparatively higher in the latter. This combined evidence would imply that the TPA‐induced differentiation of THP‐1 cells is accompanied by the rise of high affinity (type I) ER, suggesting that estrogens may play a role in the regulation of macrophage activity during the inflammatory and/or the immune response. J. Cell. Biochem. 83: 390–400, 2001. © 2001 Wiley‐Liss, Inc.
Free‐energy component analysis of 40 protein–DNA complexes: A consensus view on the thermodynamics of binding at the molecular level
Authors: Jayaram B. , McConnell K. , Dixit S. B. , Das A. , Beveridge D. L. 
Published: August 2002

AbstractNoncovalent association of proteins to specific target sites on DNA—a process central to gene expression and regulation—has thus far proven to be idiosyncratic and elusive to generalizations on the nature of the driving forces. The spate of structural information on protein—DNA complexes sets the stage for theoretical investigations on the molecular thermodynamics of binding aimed at identifying forces responsible for specific macromolecular recognition. Computation of absolute binding free energies for systems of this complexity transiting from structural information is a stupendous task. Adopting some recent progresses in treating atomic level interactions in proteins and nucleic acids including solvent and salt effects, we have put together an energy component methodology cast in a phenomenological mode and amenable to systematic improvements and developed a computational first atlas of the free energy contributors to binding in ∼40 protein–DNA complexes representing a variety of structural motifs and functions. Illustrating vividly the compensatory nature of the free energy components contributing to the energetics of recognition for attaining optimal binding, our results highlight unambiguously the roles played by packing, electrostatics including hydrogen bonds, ion and water release (cavitation) in protein–DNA binding. Cavitation and van der Waals contributions without exception favor complexation. The electrostatics is marginally unfavorable in a consensus view. Basic residues on the protein contribute favorably to binding despite the desolvation expense. The electrostatics arising from the acidic and neutral residues proves unfavorable to binding. An enveloping mode of binding to short stretches of DNA makes for a strong unfavorable net electrostatics but a highly favorable van der Waals and cavitation contribution. Thus, noncovalent protein–DNA association is a system‐specific fine balancing act of these diverse competing forces. With the advances in computational methods as applied to macromolecular recognition, the challenge now seems to be to correlate the differential (initial vs. final) energetics to substituent effects in drug design and to move from affinity to specificity. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 1–14, 2002
Quasirelativistic study of 125Te nuclear magnetic shielding constants and chemical shifts
Authors: Hada Masahiko , Wan Jian , Fukuda Ryoichi , Nakatsuji Hiroshi 
Published: August 2002

AbstractCalculations for 125Te magnetic shielding constants and chemical shifts were carried out using a quasirelativistic Hamiltonian including the spin‐free relativistic, one‐ and two‐electron spin–orbit, and relativistic magnetic interaction terms. For the tellurium‐containing series Te(CH3)2, TeH2, TeF6, Te(CH3)4, and Te(CH3)2Cl2, the relativistic effects amounted to as much as 1300 ppm and were very important for qualitatively reproducing the absolute value of the 125Te shielding constants obtained experimentally. On the other hand, for the 125Te chemical shifts the relativistic effects were less important, because they cancelled each other between the sample and reference compounds. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1502–1508, 2001
Clinical implications of research on countertransference: Science informing practice
Authors: Hayes Jeffrey A. , Gelso Charles J. 
Published: August 2002

AbstractThis article presents a clinically oriented synthesis of research findings pertaining to countertransference (CT). Findings are organized around five therapy‐relevant questions concerning the origins, triggers, manifestations, management, and effects of CT. To date, research has focused primarily on impediments posed by therapists' CT reactions and mechanisms for managing them. It is argued that future research needs to be directed toward better understanding how therapists can use CT to enhance their work with clients. © 2001 John Wiley & Sons, Inc. J Clin Psychol/In Session 57: 1041–1051, 2001.
Role of AKT kinase in sphingosine‐induced apoptosis in human hepatoma cells
Authors: Chang Hui‐Chiu , Tsai Li‐Huang , Chuang Lea‐Yea , Hung Wen‐Chun 
Published: August 2002

AbstractOur previous work has shown that a number of sphingolipid metabolites including sphingosine, sphinganine, and other long‐chain bases potently induced apoptosis in human hepatoma cells. In this study, we examined the possibility that sphingosine may trigger apoptosis in human hepatoma cells via inhibition of anti‐apoptotic pathways. We investigated the effect of sphingosine on AKT kinase, a serine/threonine kinase which was found to protect cells from apoptosis induced by a variety of extracellular stresses. Our results indicated that sphingosine inhibited basal and serum‐stimulated AKT kinase activity in a dose‐dependent manner in hepatoma cells. Additionally, sphingosine‐induced inhibition of AKT kinase was correlated with induction of apoptosis in these cells. Pretreatment of insulin, a potent stimulator of AKT kinase, partially reversed the inhibition of AKT kinase by sphingosine and counteracted the apoptotic action of this sphingolipid. Expression of activated AKT kinase partially protected cells from sphingosine‐induced apoptosis, whereas expression of kinase‐dead AKT kinase had no effect. The molecular mechanism by which AKT kinase suppressed the apoptotic action of sphingosine was investigated. Our results showed that increased release of cytochrome C from mitochondria and subsequent activation of caspase‐3 were detected in sphingosine‐treated hepatoma cells. On the contrary, expression of activated AKT kinase in Hep3B cells attenuated cytochrome C release and caspase‐3 activation induced by sphingosine. Taken together, these findings suggest that suppression of AKT kinase is one of the mechanisms by which sphingosine induces apoptosis in hepatoma cells and activation of AKT kinase may inhibit sphingosine‐induced apoptosis by blocking a step upstream of cytochrome C release and caspase‐3 activation. © 2001 Wiley‐Liss, Inc.
Phage‐mediated transfer of virulence genes
Authors: Saunders Jon R , Allison Heather , James Chloe E , McCarthy Alan J , Sharp Richard 
Published: August 2002

AbstractBacteriophages as accessory genetic elements play a crucial role in the dissemination of genes and the promotion of genetic diversity within bacterial populations. Such horizontal transfer of DNA is critical in the emergence of new pathogenic organisms, through the dissemination of genes encoding virulence factors such as toxins, adhesins and agressins. Phages can transfer genes that are not necessary for bacteriophage persistence and are generally recognised by their ability to convert their host bacteria to new phenotypes. This phenomenon is known as phage conversion. If such converting genes encode for virulence factors, the consequences of phage infection may include increased virulence of the host bacteria, and the conversion of a non‐pathogenic strain to a potentially dangerous pathogen. A number of virulence factors in bacteria causing diseases in plants, animals and humans are encoded by converting phages, the vast majority of which are temperate as opposed to lytic in nature.© 2001 Society of Chemical Industry
Ultrasound‐guided testicular sperm aspiration in azoospermic patients: A new sperm retrieval method for intracytoplasmic sperm injection
Authors: Belenky Alexander , Avrech Ory M. , Bachar Gil Nissim , Zuckerman Zvi , Rafael Zion Ben , Fisch Benjamin , Cohen Maya 
Published: August 2002

AbstractPurposeWe investigated the technique of ultrasound‐guided testicular sperm aspiration (USTSA) and compared it with “blind” testicular sperm aspiration (TSA) in patients with nonobstructive azoospermia.MethodsThirty‐nine consecutive azoospermic men underwent TSA, 16 under sonographic guidance (USTSA group) and 23 with no imaging guidance (TSA group). Clinical and hormonal evaluation and sonography of the scrotum and testes were performed 1–2 days before the procedure. The aspiration was done using short‐term general anesthesia. Follow‐up consisted of sonographic reexamination of the scrotum and testes immediately and 1 month after the procedure.ResultsIntraoperative sonography with power Doppler imaging enabled good visualization of the testicular parenchyma, easy sampling, and avoidance of prominent vessels. Sufficient material was retrieved in 15 USTSA patients (94%) and 19 TSA patients (83%). No patients needed more than 4 hours' ambulatory hospitalization after the procedure. In the remaining 5 patients, aspiration failed to yield sperm, so open biopsy was performed. In those patients, postaspiration surgical exploration revealed subtunical bleeding in 3 patients after TSA but none after USTSA. Late minor complications occurred in 2 patients (13%) in the USTSA group and 7 (30%) in the TSA group. No difference was found between the 2 groups in pregnancy rate in the patients' female partners.ConclusionsUSTSA is a safe and accurate method for sperm retrieval in azoospermic patients. © 2001 John Wiley & Sons, Inc. J Clin Ultrasound 29:339–343, 2001.
Adrenomedullin as a pancreatic hormone
Authors: López José , Cuesta Natalia 
Published: August 2002

AbstractAdrenomedullin (AM) is a multiregulatory peptide which is expressed in a wide range of tissues. In the pancreas, AM was first found in mammals, including man, and its colocalization with the pancreatic polypeptide (PP) was established in islet F cells. In addition, three different AM receptors have been characterized in B‐cells. AM has been also located in the pancreatic cells of other vertebrate classes. The frequency and distribution of AM cells vary between different animals; they can be found scattered among the exocrine tissue, in the islets, or in ductal epithelia. The colocalization of AM with other hormones presents different patterns, although in birds, as in mammals, it seems to colocalize only with PP. The best‐determined pancreatic AM function is the inhibition of insulin secretion in B‐cells, which seems to be linked to a recently discovered binding protein, factor H. In relation to this physiological role, clinical data show that AM is raised in some groups of both types I and II diabetic patients and AM might have triggered the disease in a subset of them. On the other hand, AM pancreatic cells are also involved in the response to septic shock by increasing AM circulating levels. A third putative function is the inhibition of amylase secretion by the exocrine pancreatic cells. AM has been found in embryonic mammalian pancreas from the earliest stages of the development, colocalizing with all pancreatic hormones, although in adults only coexpression with PP is kept. AM may play a role in the growth and morphogenesis of the pancreas. Microsc. Res. Tech. 57:61–75, 2002. © 2002 Wiley‐Liss, Inc.
Role of cell cycle molecules in the pathophysiology of glomerular epithelial cells
Authors: Nagata Michio , Shu Yujing , Tomari Shinsuke 
Published: August 2002

AbstractThe postmitotic characteristics of podocytes are the basis for the structural assembly and central function (filtration) of the glomeruli. Persistent cell cycle quiescence is required for stability in these cells. In cells of the podocyte lineage, transdifferentiation from the metanephric mesenchyme to mature podocytes is closely associated with tight regulation of the expression of cell cycle molecules. This cell cycle control in podocytes acts as a safeguard for the glomeruli; however, deregulation of this system might result in structural deterioration. This article focuses on the expression of cell cycle molecules in podocyte differentiation and pathology. Microsc. Res. Tech. 57:203–207, 2002. © 2002 Wiley‐Liss, Inc.
Morphological and cytochemical aspects of capillary permeability
Authors: Bendayan Moise 
Published: August 2002

AbstractTransport of plasma soluble constituents across the capillary wall is of primordial importance in cardiovascular physiology. While physiological experiments have concluded with the existence of two sets of pores, a large one responsible for the transport of proteins and a small one designed for the diffusion of small solutes, the morphological counterparts have yet to get general agreement. In this review, we present the different proposed paths within and between the endothelial cells that do allow passage of plasma constituents and may respond to the definitions established by physiological means. The vesicular system existing in endothelial cells has been the first transendothelial path to be proposed. Several data have demonstrated the involvement of this system in transport, although others have systematically brought controversy. One alternative to the vesicles has been the demonstration of membrane‐bound tubules creating, in certain cases, transendothelial channels that would allow diffusion of plasma proteins and other constituents across the capillary wall. Access to this tubulo‐vesicular system could be restrained by the stomatal diaphragm and facilitated by specific membrane receptors. Further, we have demonstrated for the first time with morpho‐cytochemical tools, that the intercellular clefts are the site of diffusion for small molecules such as peptides having a molecular weight inferior to 3,000. For the fenestrated capillary bed, we have shown that fenestrae are the site through which plasma constituents cross the capillary wall. However, and in spite of the existence of these large open pores, the endothelial cells still display the tubulo‐vesicular system involved in transport of large molecules and their intercellular clefts are also the site of diffusion of small molecules. Making consensus on the existence of an intracellular tubulo‐vesicular system in non‐fenestrated capillaries, responsible for the transport of large molecules by the endothelial cells, and understanding the rational for the fenestrated capillary to have three paths for transport—the fenestrae, the tubulo‐vesicular system, and the inter‐endothelial clefts—require further investigation. Microsc. Res. Tech. 57:327–349, 2002. © 2002 Wiley‐Liss, Inc.
Dynamics of Na+,K+,2Cl− cotransporter and Na+,K+‐ATPase expression in the branchial epithelium of brown trout (Salmo trutta) and atlantic salmon (Salmo salar)
Authors: Tipsmark Christian Kølbæk , Madsen Steffen Søndergaard , Seidelin Michel , Christensen Akim Stypinsky , Cutler Christopher Paul , Cramb Gordon 
Published: August 2002

AbstractThe dynamics of branchial Na+,K+,2Cl− cotransporter (NKCC) and Na+,K+‐ATPase (NKA) expression were investigated in brown trout and Atlantic salmon during salinity shifts and the parr‐smolt transformation, respectively. In the brown trout, Western blotting revealed that NKCC and NKA abundance increased gradually and in parallel (30‐ and ten‐fold, respectively) after transfer to seawater (SW). The NKA hydrolytic activity increased ten‐fold after SW‐transfer. Following back‐transfer to fresh water (FW), the levels of both proteins and NKA activity decreased. The NKCC immunostaining in the gill of SW‐acclimated trout was strong, and mainly localized in large cells in the filament and around the bases of the lamellae. In FW‐acclimated trout, immunostaining was less intense and more diffuse. Partial cDNAs of the secretory NKCC1 isoform were cloned and sequenced from both brown trout and Atlantic salmon gills. Two differently sized transcripts were detected by Northern blotting in the gill but not in other osmoregulatory tissues (kidney, pyloric caeca, intestine). The abundance in the gill of these transcripts and of the associated NKCC protein increased four‐ and 30‐fold, respectively, during parr‐smolt transformation. The abundance of NKA α‐subunit protein also increased in the gill during parr‐smolt transformation though to a lesser extent than enzymatic activity (2.5‐ and eight‐fold, respectively). In separate series of in vitro experiments, cortisol directly stimulated the expression of NKCC mRNA in gill tissue of both salmonids. The study demonstrates the coordinated regulation of NKCC and NKA proteins in the gill during salinity shifts and parr‐smolt transformation of salmonids. © 2002 Wiley‐Liss, Inc.
Head shape and bite performance in xenosaurid lizards
Authors: Herrel Anthony , De Grauw Ed , Lemos‐Espinal Julio A. 
Published: August 2002

AbstractBite performance in lizards influences many aspects of the animal’s lifestyle. During feeding, inter‐ and intrasexual interactions, and defensive behavior, the ability to bite hard might be advantageous. Although biomechanical considerations predict clear relations between head shape and bite performance, this has rarely been tested. Here we investigate the effect of head shape on bite performance in three closely related species of xenosaurid lizards. Our data show that in this family of lizards, bite performance is mainly determined by head height, with high headed animals biting harder than flat headed ones. Species clearly differ in head shape and bite performance and show a marked sexual dimorphism. The dimorphism in head shape also results in an intersexual difference in bite performance. As head height is the major determinant of bite performance in xenosaurid lizards, trade offs between a crevice dwelling life‐style and bite performance seem to occur. The evolutionary implications of these results are discussed. J. Exp. Zool. 290:101–107, 2001. © 2001 Wiley‐Liss, Inc.
Relationship between cerebro‐spinal fluid pH and pulmonary ventilation of the South American lungfish, Lepidosiren paradoxa (Fitz.)
Authors: Sanchez Adriana Paula , Hoffmann Anette , Rantin Francisco Tadeu , Glass Mogens Lesner 
Published: August 2002

AbstractThe respiratory control in land vertebrates (Tetrapoda) is mainly linked to regulation of acid–base status, which involves peripheral and central chemoreceptors. The lungfish (Dipnoi) might constitute the sister group of all land vertebrates (Tetrapoda) and possess a combination of real lungs and reduced gills. In this context, we evaluated the possible presence of central respiratory chemoreceptors in the South American Lungfish, Lepidosiren paradoxa. Pulmonary ventilation and respiratory frequency increased significantly with reductions of CSF pH by means of mock CSF solutions. This suggests that Lepidosiren possess central acid–base receptors. J. Exp. Zool. 290:421–425, 2001. © 2001 Wiley‐Liss, Inc.
Wnts and the female reproductive system
Authors: Heikkilä Minna , Peltoketo Hellevi , Vainio Seppo 
Published: August 2002

AbstractWnts are intercellular growth and differentiation factors that regulate several key developmental steps, such as gastrulation, neurulation, and organogenesis, including the development of the midbrain, central nervous system, kidney, and limbs. Wnts are also needed for a normal development of the reproductive system. Deficiency of Wnt‐4, ‐5a, and ‐7a, for example, results in sex reversal, infertility, and/or malformation of the internal and external genitals. Here we focus on the importance of Wnts in the female reproductive system. J. Exp. Zool. 290:616–623, 2001. © 2001 Wiley‐Liss, Inc.
Combinatorial curvature for planar graphs
Authors: Higuchi Yusuke 
Published: August 2002

AbstractRegarding an infinite planar graph G as a discrete analogue of a noncompact simply connected Riemannian surface, we introduce the combinatorial curvature of G corresponding to the sectional curvature of a manifold. We show this curvature has the property that its negative values are bounded above by a universal negative constant. We also prove that G is hyperbolic if its curvature is negative. © 2001 John Wiley & Sons, Inc. J Graph Theory 38: 220–229, 2001