bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of DRAINMOD‐S for simulating water table management under semi‐arid conditions
Authors: Wahba M. A. S. , El‐Ganainy M. , Abdel‐Dayem M. S. , Kandil H. , Gobran Atef.
Published: October 2002

The water table management simulation model, DRAINMOD‐S, was evaluated under semi‐arid conditions using field data from the Maruit experimental field in the western delta of Egypt for three cropping seasons; maize 1999, wheat 1999/2000 and maize 2000. Two water table management systems (conventional drainage (FD) and controlled drainage (CD)) were applied in the study area. The recorded data included daily ground water table depths, drain outflows during flow events, soil salinity to depth of 1.20 m from the soil surface (0.30 m interval), and relative crop yield. DRAINMOD‐S was run to simulate the applied water table management systems for the same study periods. The reliability of the model was evaluated by comparing measured and predicted values of the daily ground water table depth, cumulative outflow based on total monthly outflow, soil salinity during each season, and relative crop yield. Good agreement was found between the measured and predicted values. DRAINMOD‐S predicted values within an absolute deviation ranged from 11.0 to 16.0 cm for ground water table depth, from 18 to 75 mm for drain outflows, from 0.22 to 1.08 dS m−1 for soil salinity, and from 4.62 to 4.86% for relative crop yield. The model showed the potential for long‐term simulation and planning of ground water table management systems under semi‐arid conditions of the western delta of Egypt. Copyright © 2002 John Wiley & Sons, Ltd.
Improvement of the functions of osteoblasts seeded on modified poly(D,L‐lactic acid) with poly(aspartic acid)
Authors: Cai Kaiyong , Yao Kangde , Hou Xin , Wang Yaquan , Hou Yongjiang , Yang Zhiming , Li Xiuqiong , Xie Huiqi
Published: October 2002

One of the challenges in the field of tissue engineering is the development of biomaterial/cell interactions. For the purposes of the present study, two molecular weights of poly(aspartic acid) (PASP) were used to modify poly(D,L‐lactic acid) (PDLLA) films in order to enhance their cell affinity. The properties of the PDLLA‐modified surfaces and the controls were investigated by water contact angle measurement and electron spectroscopy for chemical analysis (ESCA). These data reflect the change in the biocompatibility of modified PDLLA surfaces. Then rat osteoblasts were seeded onto these modified surfaces and on controls to examine their effects on cell adhesion and proliferation. Cell morphologies on these surfaces were studied by scanning electron microscopy (SEM), and cell viability was evaluated with a MTT assay. In addition, differentiated cell function was assessed by measuring alkaline phosphatase (ALP) activity. The results suggest that PASP‐modified surfaces may enhance the interactions between osteoblasts and PDLLA films. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 283–291, 2002
Adsorbed poly(ethyleneoxide)–poly(propyleneoxide) copolymers on synthetic surfaces: Spectroscopy and microscopy of polymer structures and effects on adhesion of skin‐borne bacteria
Authors: Marsh Lorraine H. , Coke Mark , Dettmar Peter W. , Ewen Richard J. , Havler Michael , Nevell Thomas G. , Smart John D. , Smith James R. , Timmins Barry , Tsibouklis John , Alexander Cameron
Published: October 2002

Poly(ethyleneoxide)–copoly(propyleneoxide) (PEO‐PPO) polymer coatings were evaluated for their resistance to the attachment of the marker organism Serratia marcescens and the skin‐borne bacteria Staphylococcus epidermidis. The copolymers were adsorbed onto poly(styrene) films—chosen as simplified physicochemical models of skin surfaces—and their surface characteristics probed by contact angle goniometry, attenuated total reflectance–Fourier transform infrared (ATR‐FTIR), atomic force microscopy (AFM), and X‐ray photoelectron spectroscopy (XPS). These functional surfaces were then presented to microbial cultures, bacterial attachment was assessed by fluorescence microscopy and AFM, and the structures of the polymer films examined again spectroscopically. Surface characterization data suggest that the adsorbed copolymer was partially retained at the surface and resisted bacterial attachment for 24 h. Quantitative evaluation of cell attachment was carried out by scintillation counting of 14C‐labeled microorganisms in conjunction with plate counts. The results show that a densely packed layer of PEO‐PPO copolymer can reduce attachment of skin commensals by an order of magnitude, even when the coating is applied by a simple adsorptive process. The work supports the hypothesis that adhesion of microorganisms to biological substrates can be reduced if a pretreatment with an appropriate copolymer can be effected in vivo. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61: 641–652, 2002
Tribological investigation of oriented HDPE
Authors: Hoseini Mohammed , Lausmaa Jukka , Boldizar Antal
Published: October 2002

The possibility to control the wear properties of high‐density polyethylene (HDPE) material at an early processing stage is explored. Wear measurements of cold roll‐drawn HDPE with two different draw ratios were carried out for three sliding planes, each in two directions. The dependence of the wear properties on the degree and direction of orientation was investigated. The experiments were performed in a pin‐on‐disc machine in a dry environment. The tribo‐couple consisted of HDPE plates versus a standardised diamond coated steel disc. The results show that the wear resistance of cold roll‐drawn HDPE differ widely, by a factor up to 6, depending on the sliding direction relative to the drawing direction. The material has a significantly better wear resistance when the sliding direction was perpendicular to the processing direction. The best wear resistance was in the end plane and it was improved by a factor up to 3.6 when the draw ratio was increased from 2 to 4. These results indicate that molecular orientation by polymer processing is a promising method to improve the wear properties and decrease the wear debris production of HDPE. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61: 634–640, 2002
Induction of olfactory mucosal and liver metabolism of lidocaine by 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin
Authors: Genter Mary Beth , Apparaju Sandhya , Desai Pankaj B.
Published: October 2002

Formulation of drugs for administration via the nasal cavity is becoming increasingly common. It is of potential clinical relevance to determine whether intranasal drug administration itself, or exposure to other xenobiotics, can modulate the levels and/or activity of nasal mucosal metabolic enzymes, thereby affecting the metabolism and disposition of the drug. In these studies, we examined changes in several of the major metabolic enzymes in nasal epithelial tissues upon exposure to the environmental contaminant 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD), as well as the impact of these changes on the metabolism of a model intranasally administered drug, lidocaine. Results of these studies show that TCDD can induce multiple metabolic enzymes in the olfactory mucosa and that the pattern of induction in the olfactory mucosa does not necessarily parallel that which occurs in the liver. Further, increases in enzyme levels noted by Western blot analysis were associated with increased activities of several nasal mucosal enzymes as well as with enhanced conversion of lidocaine to its major metabolite, monoethyl glycine xylidide (MEGX). These results demonstrate that environmental exposures can influence the levels and activity of nasal mucosal enzymes and impact the pharmacology of drugs administered via the nasal route. © 2002 Wiley Periodicals, Inc. J Biochem Mol Toxicol 16:128–134, 2002. DOI 10.1002/jbt.10032
Progesterone attenuates the inhibitory effects of cardiotonic digitalis on pregnenolone production in rat luteal cells
Authors: Chen Jiann‐Jong , Chien Eileen Jea , Wang Paulus S.
Published: October 2002

Previous studies have shown that digoxin decreases testosterone secretion in testicular interstitial cells. However, the effect of digoxin on progesterone secretion in luteal cells is unclear. Progesterone is known as an endogenous digoxin‐like hormone (EDLH). This study investigates how digitalis affected progesterone production and whether progesterone antagonized the effects of digitalis. Digoxin or digitoxin, but not ouabain, decreased the basal and human chorionic gonadotropin (hCG)‐stimulated progesterone secretion as well as the activity of cytochrome P450 side chain cleavage enzyme (P450scc) in luteal cells. 8‐Br‐cAMP and forskolin did not affect the reduction. Neither the amount of P450scc, the amount of steroidogenic acute regulatory (StAR) protein, nor the activity of 3β‐hydroxysteroid dehydrogenase (3β‐HSD) was affected by digoxin or digitoxin. Moreover, in testicular interstitial and luteal cells, progesterone partially attenuated the reduction of pregnenolone by digoxin or digitoxin and the progesterone antagonist, RU486, blocked this attenuation. These new findings indicated that (1) digoxin or digitoxin inhibited pregnenolone production by decreasing the activity of P450scc enzyme, but not Na+–K+‐ATPase, resulting in a decrease on progesterone secretion in rat luteal cells, and (2) the inhibitory effect on pregnenolone production by digoxin or digitoxin was reversed partially by progesterone. In conclusion, digoxin or digitoxin decreased progesterone production via the inhibition of pregnenolone by decreasing P450scc activity. Progesterone, an EDLH, could antagonize the effects of digoxin or digitoxin in luteal cells. J. Cell. Biochem. 86: 107–117, 2002. © 2002 Wiley‐Liss, Inc.
Role of regucalcin as an activator of sarcoplasmic reticulum Ca2+‐ATPase activity in rat heart muscle
Authors: Yamaguchi Masayoshi , Nakajima Rie
Published: October 2002

The expression of regucalcin, a regulatory protein of Ca2+ signaling, and its effect on Ca2+ pump activity in the microsomes (sarcoplasmic reticulum) of rat heart muscle was investigated. The expression of regucalcin mRNA was demonstrated by reverse transcription‐polymerase chain reaction (RT‐PCR) analysis in heart muscle using rat regucalcin‐specific primers. Results with Western blot analysis showed that regucalcin protein was present in the cytoplasm, although it was not detected in the microsomes. Microsomal Ca2+‐ATPase activity was significantly increased in the presence of regucalcin (10−10–10−8 M) in the enzyme reaction mixture. This increase was not seen in the presence of thapsigargin (TP) (10−5 M), a specific inhibitor of the microsomal Ca2+ pump enzyme. Regucalcin (10−10–10−8 M) significantly stimulated ATP‐dependent 45Ca2+ uptake by the microsomes. The effect of regucalcin (10−8 M) in increasing microsomal Ca2+‐ATPase activity was completely prevented in the presence of digitonin (10−3 or 10−2%), which has a solubilizing effect on membranous lipid, or N‐ethylmaleimide (NEM), a modifying reagent of sulfhydryl (SH) groups. Dithiothreitol (DTT; 5 mM), a protecting reagent of SH groups, increased markedly Ca2+‐ATPase activity. In the presence of DTT (5 mM), regucalcin could not significantly enhance the enzyme activity. Also, the effect of regucalcin in increasing Ca2+‐ATPase activity was completely inhibited by the addition of vanadate (1 mM), an inhibitor of phosphorylation of enzyme. In addition, the effect of regucalcin on Ca2+‐ATPase activity was not significantly modulated in the presence of dibutyryl cyclic AMP (10−4 M), inositol 1,4,5‐trisphosphate (10−3 M), or calmodulin (5 μg/ml) which is an intracellular signaling factor. The present study demonstrates that regucalcin can activate Ca2+ pump activity in rat heart microsomes, and that the protein may act the SH groups of Ca2+‐ATPase by binding to microsomal membranes. J. Cell. Biochem. 86: 184–193, 2002. © 2002 Wiley‐Liss, Inc.
Specific induction of heat shock protein 27 by glucocorticoid in osteoblasts
Authors: Kozawa Osamu , Niwa Masayuki , Hatakeyama Daijiro , Tokuda Haruhiko , Oiso Yutaka , Matsuno Hiroyuki , Kato Kanefusa , Uematsu Toshihiko
Published: October 2002

It is generally recognized that osteoporosis is a common complication of patients with glucocorticoid excess and that glucocorticoid receptor is associated with heat shock protein (HSP) 70 and HSP90 in a heterocomplex. In the present study, we investigated whether glucocorticoid induces HSP27, HSP70, and HSP90 in osteoblast‐like MC3T3‐E1 cells. Dexamethasone time‐dependently increased the levels of HSP27, while having no effect on the levels of HSP70 or HSP90. The effect of dexamethasone was dose‐dependent in the range between 0.1 nM and 0.1 μM. Dexamethasone induced an increase of the levels of mRNA for HSP27. Dexamethasone induced the phosphorylation of p38 mitogen‐activated protein (MAP) kinase. SB203580 and PD169316, inhibitors of p38 MAP kinase, suppressed the HSP27 accumulation by dexamethasone. In addition, SB203580 reduced the dexamethasone‐stimulated increase of the mRNA levels for HSP27. The dexamethasone‐induced phosphorylation of p38 MAP kinase was reduced by SB203580. These results strongly suggest that glucocorticoid stimulates the induction of neither HSP70 nor HSP90, but HSP27 in osteoblasts, and that p38 MAP kinase is involved in the induction of HSP27. © 2002 Wiley‐Liss, Inc.
Detection and characterization of RANK ligand and osteoprotegerin in the thyroid gland
Authors: Hofbauer Lorenz C. , Kluger Sibylle , Kühne Christian A. , Dunstan Colin R. , Burchert Andreas , Schoppet Michael , Zielke Andreas , Heufelder Armin E.
Published: October 2002

Receptor activator of NF‐κB (RANK) ligand (RANKL) and osteoprotegerin (OPG) play essential roles in bone metabolism and immune responses. RANKL activates RANK, which is expressed by osteoclasts and dendritic cells (DC), whereas OPG acts as its decoy receptor. The role of RANKL and OPG in thyroid physiology is unclear. Northern analysis revealed pronounced OPG mRNA levels in normal human thyroid. By contrast, RANKL mRNA levels were most abundant in lymph node and appendix, and low in the thyroid. In the human thyroid follicular cell line XTC and in primary human thyroid follicular cells, OPG mRNA levels and protein secretion were upregulated by interleukin (IL)‐1β ?(33‐fold), tumor necrosis factor (TNF)‐α (eightfold), and thyrotropin (TSH) (threefold). RANKL mRNA was stimulated in XTC by IL‐1β? and TNF‐α, but inhibited by TSH. Conditioned medium harvested from IL‐1β‐treated XTC (containing high concentrations of OPG) inhibited RANKL‐induced CD40 upregulation and cluster formation of DC. OPG mRNA levels were three times more abundant in surgical thyroid specimens of Graves' disease as compared to other thyroid diseases. Our data suggest that RANKL and OPG are produced in the thyroid gland by thyroid follicular cells, are regulated by cytokines and TSH, and are capable of modulating dendritic cell functions. Thus, these cytokines may represent important local immunoregulatory factors involved in the pathogenesis of autoimmune thyroid diseases. J. Cell. Biochem. 86: 642–650, 2002. © 2002 Wiley‐Liss, Inc.
Microwave exposure induces Hsp70 and confers protection against hypoxia in chick embryos
Authors: Shallom Joshua M. , Di Carlo Andrea L. , Ko Daejin , Penafiel L. Miguel , Nakai Akira , Litovitz Theodore A.
Published: October 2002

To determine if microwave exposure could elicit a biological effect in the absence of thermal stress, studies were designed in which chick embryos were exposed to athermal microwave radiation (915 MHz) to look for induction of Hsp70, a protein produced during times of cellular stress that aids in the protection of cellular components. Levels of Hsp70 were found to increase within 2 h, with maximum expression (∼30% higher than controls) typically occurring by 3 h from the start of exposure. Other embryos were exposed to microwave radiation prior to being subjected to hypoxic stress, and were found to have significantly higher survival (P < 0.05) following re‐oxygenation than non‐exposed controls. The results of these studies indicate that not only can athermal microwave exposures activate the stress protein response pathway; they can also enhance survivability following exposure to a subsequent, potentially lethal stress. From a public health standpoint, it is important that more studies be performed to determine if repeated exposures, a condition likely to be found in cell phone use, are still beneficial. J. Cell. Biochem. 86: 490–496, 2002. © 2002 Wiley‐Liss, Inc.
Interaction of the retinoblastoma gene product, RB, with cyclophilin A negatively affects cyclosporin‐inhibited NFAT signaling
Authors: Cui Yukun , Mirkia Kirash , Florence Fu Yu‐Hsieh , Zhu Li , Yokoyama Kazunari K. , Chiu Robert
Published: October 2002

The retinoblastoma susceptibility gene product, p105Rb (RB), is generally believed to be an important regulator in the control of cell growth, differentiation, and apoptosis. Several cellular factors that form complexes with RB and exert their cellular regulatory functions have been identified, such as the newly identified RB:cyclophilin A (CypA) complex. The physical interactions between RB and CypA were demonstrated by glutathione S‐transferase affinity matrix binding assays and immunoprecipitation, followed by Western blot analyses. The N‐terminal region of CypA mediated the interaction with RB, whereas the region upstream of the A‐pocket of RB was required for binding to CypA. Ectopic expression of RB into Jurkat cells partially blocks the function of cyclosporin (CsA) to inhibit nuclear factor for activation of T cell (NFAT) activation by phorbol ester (PMA) plus ionomycin A (IA), suggesting that RB may prevent CsA inhibition of T lymphocyte activation. These results are further evidenced by the effect of RB on both calcineurin (CN) and NFAT binding activity in vitro, suggesting that the interaction of RB with CypA interferes with the CsA:CypA complex and blocks CsA‐inhibited CN activity. These data reveal the functional link between RB and CypA and their involvement in T cell activation signaling. J. Cell. Biochem. 86: 630–641, 2002. © 2002 Wiley‐Liss, Inc.
Reducing I/O costs for the eigenvalue procedure in large‐scale configuration interaction calculations
Authors: Shepard Ron , Shavitt Isaiah , Lischka Hans
Published: October 2002

Several aspects of the matrix diagonalization method used for CI calculations in the COLUMBUS Program System are discussed, including a linear basis‐contraction algorithm and the use of a nonorthogonal expansion basis. Both of these features significantly reduce the I/O requirements during the iterations. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 1121–1125, 2002
Studies on 4,7‐di‐substitution effects of one ligand in [Ru(Phen)3]2 with DFT method
Authors: Zheng Kangcheng , Wang Juping , Shen Yong , Peng Wenlie , Yun Fengcun
Published: October 2002

Studies on the complex [Ru(phen)3]2+ (phen = 1,10‐phenanthroline) and its derivatives with 4,7‐di‐substitution on one ligand(phen) were carried out using the DFT method at the B3LYP/LanL2DZ level of theory. The trends in the substituent effects caused by the electron‐pushing group (OH) and the electron‐withdrawing group (F), on the electronic structures and the related properties, for example, the energies and the components of some frontier molecular orbitals, the spectroscopy properties, and the net charge populations of some main atoms of the complexes, etc., have been investigated. The computational results show that the substituents have some interesting effects on the electronic structures and the related properties of the complexes. First, according to the analysis of components of LUMO of the complexes, the electron‐withdrawing group (F) can activate the main ligand (the substituted ligand, i.e., 2R‐phen) and passivate the coligands, on the contrary, the electron‐pushing group (OH) can activate the coligands and passivate the main ligand in the first electronic excited states of complexes. Second, both the electron‐pushing group (OH) and the electron‐withdrawing group (F) can cause a red shift in the electronic ground bands. Third, the characteristics of the atomic net charge populations on the main ligand can also be analyzed in detail by means of a schematic map expressed by several series of arrowheads based on the law of polarity alternation and the idea of polarity interference. The most negative charges are populated on N1, the next most net negative charges are populated on C3 among the skeleton atoms for the three complexes, etc. The computational results can be better used to explain some experimental phenomena and trends. © 2002 Wiley Periodicals, Inc. J Comput Chem 4: 436–443, 2002; DOI 10.1002/jcc.10038
EQUIPATH—an equilibrial path tracing routine for the use with the program package GAUSSIAN94
Authors: Kliesch Wolfgang
Published: October 2002

The present article deals with the numerical details important for a successful implementation of the equilibrial path tracing procedure EQUIPATH. The results of an application to the RHF/6‐31G(d) potential energy surface of butane are reported and discussed. Sixteen saddle points and several valley‐ridge inflection points have been located. For the fragmentation C4H10→ C2H6+C2H4 two different reaction paths have been found. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1801–1816, 2001
Symptoms of schizophrenia and neurocognitive test performance
Authors: Shean Glenn , Burnett Traverse , Eckman F. Scott
Published: October 2002

Schizophrenic in‐patients were rated on factor‐derived symptom dimensions based on negative and positive symptom ratings. Participants were administered neuropsychological tests (digit span, digit vigilance, logical memory, and Trails A and B) and then instructed on how to improve performance on the tests. Follow‐up tests were administered shortly after coaching. Comparisons of pre‐ and post‐instruction test scores indicated that the patient group was able to improve significantly their performance on the tests after coaching. Symptom dimensions were predictive of improved post‐instruction test performance beyond the impact of the level of pre‐instruction scores. Symptoms of disorganization and negative symptoms were related to lack of ability to improve performance on one or more of the tests, and positive symptoms and premorbid adjustment were associated with improved post‐instruction performance. The symptom dimensions provide a potentially useful approach to reducing heterogeneity within samples of schizophrenic patients. © 2002 Wiley Periodicals, Inc. J Clin Psychol 58: 723‐731, 2002.
Correspondence between supervisors and trainees in their perception of supervision events
Authors: Reichelt Sissel , Skjerve Jan
Published: October 2002

The focus of this study is on how the participants in 16 supervisory dyads perceive the content and process in a supervisory session, and on the meaning they attach to supervisory events. A central issue is to what degree the participants in each dyad correspond in their perceptions and evaluation of supervisory events. Another question is how lack of correspondence affects the trainees' experience of satisfaction with the supervision. A majority of the dyads were rated low or moderate in correspondence, and it is discussed whether the influence of low correspondence on trainee satisfaction may be related to supervisory intentions and style characteristics. A main point in the discussion is whether role ambiguity may be related to obscure communication and reduced correspondence, and it is suggested that more attention should be paid to negotiating and renegotiating rules for the supervisory relationship. © 2002 Wiley Periodicals, Inc. J Clin Psychol 58: 759‐772, 2002.
Predictors of graduate student attitudes toward prescription privileges for psychologists
Authors: Luscher Kristen A. , Corbin William R. , Bernat Jeffrey A. , Calhoun Karen S. , McNair Lily D.
Published: October 2002

The issue of gaining prescription privileges and its potential impact on the field of clinical psychology has special relevance for graduate students. This study was designed to investigate clinical graduate students' attitudes toward prescription authority, identify salient variables that contribute to these attitudes, and ascertain preferred models of training. Only 42.5% of respondents personally desired to obtain prescription privilege, although 61.8% of respondents favored efforts of the American Psychological Association to acquire prescription authority. Proponents and opponents were compared on their ratings of positive and negative aspects of the debate. There was strong agreement that the training should not be predoctoral and that it should lead to board certification. The strongest predictors of graduate students' attitudes were concerns about fundamental change to the field, malpractice premiums, and whether they considered it a logical extension of the field. This study provides a framework for understanding important factors influencing the decision‐making process among clinical psychology graduate students. © 2002 Wiley Periodicals, Inc. J Clin Psychol 58: 783‐792, 2002.
Depression and trauma history in first‐time mothers receiving home visitation
Authors: Stevens Jack , Ammerman Robert T. , Putnam Frank G. , Van Ginkel Judith B.
Published: October 2002

This article examines the prevalence and correlates of depression and trauma history in first‐time mothers receiving home visitation. One hundred twenty‐three mothers in a Healthy Families America (HFA) program completed measures of depression, trauma history, social support, sense of control, and child abuse risk. Number of completed home visits, number of uncompleted home visits, and total telephone contact time were documented for each participant over the first 6 months of enrollment. Nearly 30% of the mothers scored in the clinically significant range on the depression measure. Approximately 70% of the sample had experienced at least one violent trauma. Depression and violent trauma, but not nonviolent trauma, were related to greater child abuse risk and less maternal sense of control and social support. Violent traumas were related to greater interruptions in service delivery as reflected by more uncompleted home visits. After controlling for social support and sense of control, depression was associated with more telephone contact between mothers and home visitors. Mothers receiving home visitation exhibited a heightened incidence of depression and trauma history relative to the population at large. These constructs were related to social support and sense of control, both of which are targets of home visitation. Depression and trauma history may significantly influence the delivery and outcomes obtained from home visitation. © 2002 Wiley Periodicals, Inc.
Progression elevated gene‐3, PEG‐3, induces genomic instability in rodent and human tumor cells
Authors: Su Zao‐zhong , Gopalkrishnan Rahul V. , Narayan Gopeshwar , Dent Paul , Fisher Paul B.
Published: October 2002

Genomic instability is a fundamental component of cancer progression. Subtraction hybridization identified a novel rodent gene, progression elevated gene‐3 (PEG‐3) whose expression directly correlates with cancer aggressiveness and progression. Moreover, ectopic expression of PEG‐3 in rodent or human tumor cells produces an aggressive transformed phenotype. We demonstrate that PEG‐3 expression in rodent tumor cells correlates directly with genomic instability as characterized by alterations in chromosome composition and structure. Additionally, elevated endogenous or ectopic expression of PEG‐3 in rodent and human tumor cells, respectively, enhances gene amplification, as monitored by resistance to methothrexate (MTX) and amplification of the dihydrofolate reductase (dhfr) gene. Stable expression of PEG‐3 in normal cloned rat embryo fibroblast (CREF) cells marginally elevates MTX resistance, but morphology remains unaltered and anchorage independence is not induced, suggesting that these phenotypes are separable in immortal cells and gene amplification may precede the acquisition of morphological and oncogenic transformation. The present studies document that stable, inducible, and transient expression of PEG‐3 in cancer cells augments genomic instability. In these contexts, one mechanism by which PEG‐3 influences cancer progression may be by preferentially facilitating the development of genomic changes in evolving cancer cells. © 2002 Wiley‐Liss, Inc.
Observer experience improves reproducibility of color doppler sonography of orbital blood vessels
Authors: Németh János , Kovács Rita , Harkányi Zoltán , Knézy Krisztina , Sényi Katalin , Marsovszky István
Published: October 2002

Purpose.

The study investigated the reproducibility of orbital blood flow measurements with color Doppler imaging (CDI) at different stages of observer experience.

Methods.

The subjects were 31 healthy volunteers and 2 sequential groups of 25 glaucoma patients each. Repeated blood flow measurements (usually 3 sets) in orbital vessels (ophthalmic artery, short posterior ciliary arteries, central retinal artery, and central retinal vein) were performed by the same observer in a single session in each subject.

Results.

The parameters with the best reproducibility were the resistance index (mean coefficient of variation [COV], 3.3–8.8%), the peak systolic velocity (mean COV, 6.9–13.7%), the time‐averaged velocity (mean COV, 7.2–16.0%), and the systolic acceleration time (mean COV, 8.8–12.3%). The mean COV was greater (9.9–20.3%) for the other arterial flow parameters (end‐diastolic velocity and systolic acceleration) and for the venous flow velocities (maximum and minimum). The COVs of the parameters were improved by 20–40% as the observer became more experienced in ophthalmic CDI.

Conclusions.

We confirm the general reliability of CDI measurements in orbital vessels and show that observer experience improves reproducibility. It appears, however, that observer performance in these measurements is vessel specific. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:332–335, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jcu.10079
Intraurethral sonography and the test‐retest reliability of urethral sphincter measurements in women
Authors: Heit Michael
Published: October 2002

Purpose.

The purpose of this prospective study was to determine the test‐retest reliability of urethral sphincter morphologic measurements obtained with intraurethral sonography.

Methods.

The cross‐sectional urethral sphincter anatomy of 29 asymptomatic nulliparous women was studied in a blinded fashion. Each patient returned for a repeat examination on a different day. At the point of maximal rhabdosphincter thickness, the urethral diameter and circumference and the longitudinal smooth muscle and rhabdosphincter thickness, diameter, circumference, and area were measured using the ultrasound scanner's integrated software. For each measured variable, the reliability between patients was assessed with a paired t test. Intraclass correlation coefficients were calculated to assess the reliability of each intraurethral sonographic measurement obtained from the same patient.

Results.

On test‐retest analysis, the differences for each measured variable between patients were not statistically significant (p > 0.05). Of the measurements obtained from the same patient, however, longitudinal smooth muscle thickness (ρ = 0.44; p = 0.006), diameter (ρ = 0.49, p = 0.003), circumference (ρ = 0.49, p = 0.003), and area (ρ = 0.43; p = 0.009) were significantly correlated.

Conclusions.

The urethral longitudinal smooth muscle layer is the only structure that can be measured reliably using sonography for diagnostic use. Sonographic measurements of the rhabdosphincter may not be reliable because the outer portion of that structure lies outside the depth of penetration of a 12.5‐MHz transducer. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:349–355, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jcu.10082
Changes in macrophage morphology and prolonged cell viability following exposure to polyethylene particulate in vitro
Authors: Xing Shaomo , Waddell J.E. , Boynton E.L.
Published: October 2002

The interaction of macrophages and ultra‐high molecular weight polyethylene (PE) wear plays an important role in perpetuating chronic inflammation at the bone implant interface, leading to peri‐implant osteolysis and mechanical failure of the implant. A model to study the interaction of human mature macrophages with orthopaedic biomaterial wear has been previously developed. With the use of the model, in this study, the mature human monocyte‐derived macrophages (MDMs) were observed with light, fluorescent, and scanning electron microscopy (SEM), as well as transmission electron microscopy (TEM). The cell viability was investigated using calcein and ethidium staining. Following exposure to PE particulate, the morphology of the human MDMs was heterogeneous: rounded, flattened, and elongated. There was no morphological evidence of cytotoxicity or apoptosis. The MDM viability was not influenced by phagocytosis of PE particulate in a negative fashion. In fact, more prolonged cell viability was observed in the human MDMs exposed to PE particulate when compared to controls. Microsc. Res. Tech. 57:523–529, 2002. © 2002 Wiley‐Liss, Inc.
Streptomycetes cultured on glass beads: Sample preparation for SEM
Authors: Kofroňová Olga , Nguyen Liem Duy , Weiser Jaroslav , Benada Oldřich
Published: October 2002

We demonstrate the preparation of samples of streptomycetes (Streptomyces coelicolor, S. aureofaciens) cultured on glass beads (balotina) for scanning electron microscopy. The main trick of the method consists in immobilization of glass beads with low‐melting agarose. The samples are then fixed in OsO4 vapors followed by dehydration in vapors of absolute ethanol. No air‐to‐liquid transition during the sample preparation occurs. Consequently, whole cell cycle of streptomycetes in the term of mycelial morphology can readily be studied by this method. Microsc. Res. Tech. 58:111–113, 2002. © 2002 Wiley‐Liss, Inc.
Differential regulation of spontaneous and heat‐induced HSP 70 expression in developing zebrafish (Danio rerio)
Authors: Yeh Fu‐lung , Hsu Todd
Published: October 2002

A spontaneous high expression of heat shock protein 70 (HSP 70) was found to arise in zebrafish (Danio rerio) at the larval stage (84 hr after fertilization). The level of HSP 70 in 84‐hr‐old larvae was estimated to be six‐ to eightfold that of 12‐hr‐old embryos. As heat‐induced HSP 70 synthesis in many eukaryotic organisms is known to be mediated by a transcriptional‐dependent pathway activated by heat shock factor 1 (HSF‐1), we then examined if the spontaneous and heat‐induced HSP 70 synthesis in zebrafish were controlled by the same mechanism. Although the transient increase of a 62‐kDa HSF‐1‐like polypeptide in 72‐ to 96‐hr‐old larvae seemed to correlate with the onset of the spontaneous HSP 70 production, an anti‐HSF‐1 antibody cocktail supershifted the heat shock element (HSE) binding complex induced by stressed but not by unstressed zebrafish extracts. Northern blot and quantitative RT‐PCR analysis demonstrated the predominant presence of the cognate form of hsp 70 mRNA (hsc 70 mRNA) in developing zebrafish. The extent of heat‐induced HSP 70 production in 84‐hr‐old larvae matched well with a dramatic increase in hsp 70 mRNA accumulation, while no apparent increase in total hsp 70 mRNA could be detected in 72‐ to 84‐hr‐old unstressed larvae by northern blot analysis. The stable expression of hsc 70 mRNA specific to β‐actin mRNA in normal zebrafish was confirmed by RT‐PCR analysis. Hence, the spontaneous high expression of HSP 70 in zebrafish is believed to be controlled by a mechanism different from the HSF‐1‐dependent transcriptional activation of hsp 70 under heat stress. J. Exp. Zool. 293:349–359, 2002. © 2002 Wiley‐Liss, Inc.
Chloride‐ATPase dephosphorylation in Aplysia gut
Authors: GERENCSER GEORGE A. , ZHANG JIANLIANG
Published: October 2002

The present study was done primarily to compare cation‐ATPase dephosphorylation kinetics with a Cl−‐ATPase's dephosphorylation kinetics because of the paucity of information in this area. Utilizing a proteoliposomal preparation containing Cl−‐ATPase from Aplysia gut, it was demonstrated that dephosphorylation of this P‐type ATPase was absolutely dependent upon Cl−. Adenosine triphosphate (ATP) concentrations directly stimulated dephosphorylation of Cl−‐ATPase in the presence of increasing concentrations of Cl−. It was also shown that the calculated rate constant for E1‐P disintegration was 20/sec. This rate constant value approximated E1‐P rate constant disintegration values for other electrogenic, uniport P‐type ATPases. Therefore, it was concluded from these results that the Cl−‐ATPase dephosphorylation kinetics did not differ greatly from cation‐ATPase dephosphorylation kinetics. © 2002 Wiley‐Liss, Inc.
An experimental test of the relationship between temporal variability of feeding opportunities and baseline levels of corticosterone in a shorebird
Authors: RENEERKENS JEROEN , PIERSMA THEUNIS , RAMENOFSKY MARILYN
Published: October 2002

In this study, we tested the hypothesis that baseline corticosterone levels increase with a change from constant to variable feeding schedules. Captive red knots, Calidris canutus, were presented with food that was either available during the same time each day (constant) or starting at variable times during the day. Food intake rates, frequency of aggressive interactions, and baseline levels of corticosterone were measured. In the majority of cases, red knots showed higher plasma corticosterone concentrations during feeding schedules that were irregular than when food was available at consistent times. These findings are supported by a previous study that showed that red knots take a long time to adjust to the newly offered, predictable conditions of their aviary environment. The frequency of conflicts in the different groups and (size‐corrected) body mass were not correlated with average corticosterone level. The results are examined in the light of literature showing that increases in corticosterone in response to acute, unpredictable events mediate behavioral responses such as increased explorative behavior and memory. For red knots that have to find their food on the temperate‐zone mudflats in Western Europe, an increased circulating corticosterone level may be adaptive during periods when the patchily distribution of buried bivalves and the burying behavior of such prey presents them with a variable and unpredictable food supply. © 2002 Wiley‐Liss, Inc.
Myocyte ploidy in heart chambers of birds with different locomotor activity
Authors: Anatskaya Olga V. , Vinogradov Alexander E.
Published: October 2002

The ploidy levels of atrio‐ and ventriculocytes were determined by means of cytofluorimetry in 31 species of birds. The obtained data were collated with postnatal growth rate, heart mass index, and relative masses of heart chambers. The difference between mean ploidy of cardiomyocytes in the left and right atrium is small (7.9±0.6%) and comparable to the difference in the masses of these chambers (10.5±0.8%). The difference between mean ploidy of atrio‐ and ventriculocytes is most pronounced for the left and right parts of heart (23.9±1.4% and 24.0±1.3%, respectively) and corresponds to considerable differences in the average masses of atria and ventricles (4.5‐fold and 2.1‐fold, respectively). The mean cardiomyocyte ploidy levels in the left and right ventricles differ only slightly, as in the case of atria (by 8.1±0.5%), whereas the average mass of the left ventricle is greater by 237±16%. This discord can be explained by peculiarities of the growth, which is nonproportionally faster in the left ventricle during the last stage of proliferative heart growth as compared to other chambers. The cardiomyocyte ploidy is higher in birds with a relatively small heart and lower ability to flight. Birds with a high locomotor activity in the adult state have an athletic heart (mass index >1%); they are fast growing, altricial species with a low heart workload in the early postnatal ontogenesis. Birds with a low locomotor activity at the adult state are precocial; they grow slowly and have a high locomotor activity from the first minutes of life. Thus, notwithstanding the fact that a greater elevation of cardiomyocyte ploidy level is acquired under a higher functional load (ventricles vs. atria, left vs. right part of the heart), it is associated with a lower functional potential of the organ at the adult state. The level of somatic polyploidy can be considered an indicator of developmental tensions arising due to a high workload during the growth of a given organ and deficiency of resources invested into this growth. J. Exp. Zool. 293:427–441, 2002. © 2002 Wiley‐Liss, Inc.
Gallium nitrate: effects on cartilage during limb regeneration in the axolotl, Ambystoma mexicanum
Authors: Tassava Roy A. , Mendenhall Luciara , Apseloff Glen , Gerber Nicholas
Published: October 2002

Gallium nitrate, a drug shown to have efficacy in Paget's disease of bone, hypercalcemia of malignancy, and a variety of experimental autoimmune diseases, also inhibits the growth of some types of cancer. We examined dose and timing of administration of gallium nitrate on limb regeneration in the Mexican axolotl, Ambystoma mexicanum. Administered by intraperitoneal injection, gallium nitrate inhibited limb regeneration in a dose‐dependent manner. Gallium nitrate initially suppressed epithelial wound healing and subsequently distorted both anterior‐posterior and proximo‐distal chondrogenic patterns. Gallium nitrate given at three days after amputation severely inhibited regeneration at high doses (6.25 mg/axolotl) and altered the normal patterning of the regenerates at low doses (3.75 mg/axolotl). Administration of 6.25 mg of gallium nitrate at four or 14 days prior to amputation also inhibited regeneration. In amputated limbs of gallium‐treated axolotls, the chondrocytes were lost from inside the radius/ulna. Limbs that regenerated after gallium treatment was terminated showed blastema formation preferentially over the ulna. New cartilage of the regenerate often attached to the sides of the existing radius/ulna proximally into the stump and less so to the distal cut ends. J. Exp. Zool. 293:384–394, 2002. © 2002 Wiley‐Liss, Inc.
Distribution of GFAP immunoreactive structures in the rhombencephalon of the sterlet (Acipenser ruthenus) and its evolutionary implication
Authors: Kálmán Mihály , Ari Csilla
Published: October 2002

Previous studies have revealed that although the brains of cypriniform teleosts (iberian barb, Barbus comiza; carp, Cyprinus carpio; goldfish, Carassius auratus) are rich in glial fibrillary acidic protein (GFAP), they have, however, areas devoid of GFAP immunoreactivity. The largest ones of these are in the rhombencephalon, e.g., the zones of the sensory and motor neurons in the vagal lobe. Our studies in amniotes suggested that the GFAP immunonegative areas could be characteristic of the more advanced brains (avian and mammalian), whereas no similar areas were found in reptiles. A similar tendency was found in the Chondrichthyes, i.e., GFAP immunonegative areas appeared as brain complexity progressed. The question arose whether the GFAP immunonegative brain areas in the Teleostei were also the result of such a tendency. Within the radiation of ray‐finned fishes (Actinopterygii), Chondrostei represent a less advanced level as compared to the Teleostei. Therefore, the distribution of GFAP immunoreactivity was investigated in the rhombencephalon of the sterlet (Acipenser ruthenus) as a representative of Chondrostei, and in the carp. Serial vibratome sections were processed according to the avidin‐biotinylated horseradish peroxidase method.

Several comparable GFAP immunoreactive structures were found in the two species: the dense periventricular ependymoglial plexus, the midsagittal glial septum, the small glial septa separating the nerve fiber bundles, and the wide glial endfeet lining the meningeal surface. In the vagal lobe in the zones adjacent to the meningeal and ventricular surfaces, the glial structures also proved to be similar. In contrast to the carp, however, no areas were found devoid of GFAP immunoreactivity in the sterlet.

The results suggest that this trend of glial evolution, i.e., GFAP immunonegative areas appearing as brain complexity progressed, is a common feature shared by Actinopterygii, Amniota, and Chondrichthyes, despite their separate evolutionary histories. J. Exp. Zool. 293:395–406, 2002. © 2002 Wiley‐Liss, Inc.
Amphi‐Eomes/Tbr1: an amphioxus cognate of vertebrate Eomesodermin and T‐Brain1 genes whose expression reveals evolutionarily distinct domain in amphioxus development
Authors: Satoh Gouki , Takeuchi Jun K. , Yasui Kinya , Tagawa Kunifumi , Saiga Hidetoshi , Zhang Peijun , Satoh Nori
Published: October 2002

A cDNA for a novel T‐box containing gene was isolated from the amphioxus Branchiostoma belcheri. A molecular phylogenetic tree constructed from the deduced amino acid sequence of the isolated cDNA indicates that this gene belongs to the T‐Brain subfamily. In situ hybridization reveals that the expression is first detected in the invaginating archenteron at the early gastrula stage and this expression is down‐regulated at the neurula stage. In early larvae, the expression appears again and transcripts are detected exclusively in the pre‐oral pit (wheel organ‐Hatschek's pit of the adult). In contrast to the vertebrate counterparts, no transcripts are detected in the brain vesicle or nerve cord throughout the development. These results are interpreted to mean that a role of T‐Brain products in vertebrate forebrain development was acquired after the amphioxus was split from the lineage leading to the vertebrates. On the other hand, comparison of the tissue‐specific expression domain of T‐Brain genes and other genes between amphioxus and vertebrates revealed that the pre‐oral pit of amphioxus has several molecular features which are comparable to those of the vertebrate olfactory and hypophyseal placode. J. Exp. Zool. (Mol. Dev. Evol.) 294:136–145, 2002. © 2002 Wiley‐Liss, Inc.
Evolution of developmental functions by the Eomesodermin, T‐brain‐1, Tbx21 subfamily of T‐box genes: insights from amphioxus
Authors: Horton Amy C. , Gibson‐Brown Jeremy J.
Published: October 2002

We have identified an amphioxus T‐box gene that is orthologous to the Eomesodermin, T‐brain‐1, and Tbx21 genes of vertebrates, and we have characterized its expression pattern during embryonic and larval development. AmphiEomes/Tbr1/Tbx21 is maternally expressed in oocytes and cleavage stage embryos. After the onset of zygotic transcription at the blastula stage, it is expressed in invaginating mesendoderm cells during gastrulation, but it is downregulated in presumptive ectoderm and neurectoderm. Expression is seen in both axial and paraxial mesendoderm in neurulae and early larvae, but it is not detected in differentiated endoderm, somites, or notochord. Expression persists in mesendoderm cells of the tail bud in early larvae, but it disappears between 1 to 1.5 days post fertilization. Unlike orthologous genes in basal deuterostomes or vertebrates, no anterior neural expression domain is detected at any stage of development. Integrating phylogenetic and developmental data, we have reconstructed the evolutionary history of the Eomesodermin/Tbr1/Tbx21 subfamily of T‐box genes from a single ancestral locus that originated very early in metazoan evolution, before the evolution of triploblasts from their diploblast ancestor. J. Exp. Zool. (Mol. Dev. Evol.) 294:112–121, 2002. © 2002 Wiley‐Liss, Inc.