bluuebunny/crossref_metadata_2025 huggingface dataset:
Controls on evapotranspiration at a subarctic sedge fen
Authors: Eaton Andrea K. , Rouse Wayne R.
Published: August 2002

In this study, 10 years (1990–99) of summertime data collected at a representative sedge fen in the Hudson Bay Lowland (HBL) are used to investigate the energy and water balance dynamics of subarctic wetlands. The summertime climatic characteristics at the study site during the 10 year study period are also examined. It is shown that mean cumulative summertime precipitation Pavg for the study decade closely approximates the 30 year mean Pavg. However, the mean summertime air temperature Tavg for the study decade is 1 °C higher than the 30 year mean Tavg.

To examine the energy and water balance dynamics at the study site, the variation in each of their respective components throughout the study decade is considered. Little variation is observed in cumulative summertime net radiation $Q^{*}_{\rm cum}$ and cumulative summertime ground heat flux QGcum; however, substantial year‐to‐year variation is evident in cumulative summertime water deficit WDcum, cumulative summertime precipitation Pcum, cumulative summertime sensible heat flux QHcum, and cumulative summertime latent heat flux QEcum. It is noted that the variability in QEcum is particularly significant because it consumes the largest proportion of the available summertime energy, and is the largest component of the summertime water balance at this subarctic wetland.

Past research has suggested that Q*, P, and T have the most influence on summertime QE at high‐latitude wetlands. To test this hypothesis at our study site, QEcum, Pcum, Tavg and $Q^{*}_{\rm cum}$ from each year in the study decade were examined. It is observed that high QEcum is associated with high Pcum, Tavg and $Q^{*}_{\rm cum}$, and that low QEcum is associated with low Pcum and Tavg. To identify the hydroclimatological variables that are most responsible for controlling QEcum dynamics at the sedge fen, a stepwise linear regression was performed. This analysis indicates that Pcum and $Q^{*}_{\rm cum}$ are the most important hydroclimatological controls over QEcum. However, it is demonstrated that the variability in Pcum is more responsible than the variability in $Q^{*}_{\rm cum}$ for the variability in QEcum during the study decade because of its higher coefficient of variation. The results of this study have broader applicability to wetlands in other parts of the subarctic ecoregion, including the Mackenzie River Basin (MRB). For example, past studies have shown similarities in the energy balance regimes at wetland sites from the HBL and MRB. Copyright © 2001 John Wiley & Sons, Ltd.
Action memory and self‐monitoring in children with autism: self versus other
Authors: Hill Elisabeth L. , Russell James
Published: August 2002

One key component of executive function is self‐monitoring. While a number of studies have implied that self‐monitoring deficits may exist in autism (e.g. Russell and Jarrold, 1998), direct tests of this explanation have failed to reveal an autism‐specific deficit (Russell and Hill, 2001). In order to assess further whether a self‐monitoring deficit is present in autism, three groups of children (20 children with autism, 20 with moderate learning difficulties and 20 typically developing children, all matched for verbal mental age) participated in an action memory task. First, the participant and experimenter took turns to produce actions with pairs of objects. Second, participants were presented with an unexpected recall task in which they were required to (i) make a familiarity judgement, (ii) produce an event memory and (iii) produce a source attribution (self/other) concerning the actions performed on these pairs of objects. Broadly speaking, no performance differences were seen between the three participant groups, although there was a small but significant difference in source attributions for the accurately performing children with autism and the less accurately performing children with moderate learning difficulties. We discuss the findings in relation to the literature concerning self‐monitoring in autism. Copyright © 2002 John Wiley & Sons, Ltd.
Cancer mortality in the European Union, 1988–1997: The fall may approach 80,000 deaths a year
Authors: Levi Fabio , Lucchini Franca , Negri Eva , La Vecchia Carlo
Published: August 2002

After the peak rate of cancer mortality reached in 1988 in the European Union, steady declines were observed: 9.1% for both sexes combined over the period 1988–1997 (from 147.0 to 133.6/100,000, world standard), corresponding to the avoidance of about 80,000 deaths in 1997 (approximately 39,000 below age 65 and 41,000 above). In 1997, the total number of cancer deaths also declined, for the first time. The major determining cancers for these favorable trends were stomach (−30%), lung (−10%), intestines (−15%), breast (−10%), uterus (mainly cervix; −22%), leukemias (−10%) and, after 1995, prostate (−3%). © 2002 Wiley‐Liss, Inc.
bc10: A novel human bladder cancer‐associated protein with a conserved genomic structure downregulated in invasive cancer
Authors: Gromova Irina , Gromov Pavel , Celis Julio E.
Published: August 2002

To identify novel genes that may be associated with the invasive phenotype of bladder cancer, we compared the mRNA expression profiles of fresh noninvasive (grade II, Ta) and invasive (grade III, T2–T4) human transitional cell carcinomas (TCCs) by mRNA differential display. Using this approach, we isolated a novel gene, designated bc10 (bladder cancer, Mr 10 kDa) that was exclusively expressed in the noninvasive lesions as judged by reverse transcriptase polymerase chain reaction analysis of a panel of 30 grade II, Ta and grade III, T2–T4 TCCs. The full‐length bc10 cDNA contains a complete open reading frame (ORF) of 263 bp and encodes a protein composed of 87 amino acids that has no homology to any of the known protein families. Transient expression of bc10 cDNA in COS1 cells yielded a primary translation product with an apparent Mr of 9.8 kDa and pI of 6.7, in agreement with the theoretical calculated value. Comparison of mouse and human bc10 genomic loci revealed an intronless organization of the coding region in both species as well as a highly conserved structure having 91% and 100% identity at the DNA (coding region) and protein levels, respectively. Southern analysis did not reveal gross DNA rearrangements within the bc10 genomic locus in the invasive tumors, implying that the differential expression of the gene most likely reflects alterations in messenger expression (transcription and/or mRNA decay). The downregulation of this novel marker in invasive tumors suggests a putative role in bladder cancer progression. © 2002 Wiley‐Liss, Inc.
An algorithm for evaluating the ethics of a placebo‐controlled trial
Authors: Amdur Robert J. , Biddle C.J.
Published: August 2002

The purpose of this article is to clarify the decision points that are important to consider when evaluating the ethics of a placebo‐controlled trial. The ethical requirements for research involving human subjects are reviewed, and the rationale for and potential problems with concomitant placebo control are explained. A series of case discussions are used to illustrate each decision point. The critical decision points in the evaluation of the ethics of a placebo‐controlled trial are as follows: (i) Is placebo being used in place of standard therapy? (ii) Is standard therapy likely to be effective? (iii) Is the toxicity of standard therapy such that patients routinely refuse this treatment? (iv) Could the use of placebo result in severe suffering or irreversible harm? (v) Is the variability in the placebo response such that it is reasonable to consider other options for the control group? (vi) Would a reasonable person with an average degree of altruism and risk aversiveness agree to participate in this study? The algorithm presented in this article gives researchers and research monitors (such as Institutional Review Board members) the tools they need to evaluate the ethics of a study that uses concomitant placebo control. © 2001 Wiley‐Liss, Inc.
Prostasin serine protease inhibits breast cancer invasiveness and is transcriptionally regulated by promoter DNA methylation
Authors: Chen Li‐Mei , Chai Karl X.
Published: August 2002

We have shown that prostasin serine protease is downregulated in high‐grade prostate tumors and inhibits invasiveness of prostate cancer cell lines upon enforced reexpression. In our study, prostasin mRNA and protein were shown to be expressed in normal human mammary epithelial cells (NHMEC), the poorly invasive breast carcinoma cell line MCF‐7 and the nonmetastatic breast carcinoma cell line MDA‐MB‐453, but absent in highly invasive and metastatic breast carcinoma cell lines MDA‐MB‐231 and MDA‐MB‐435s. Enforced reexpression of prostasin in MDA‐MB‐231 and MDA‐MB‐435s reduced the in vitro invasiveness of either cell line by 50%. Examination of the prostasin gene promoter and first exon revealed a GC‐enriched region that contains transcription regulatory elements. The promoter and exon 1 region of the prostasin gene was investigated for DNA methylation in NHMEC and the carcinoma cell lines. The results revealed a methylation pattern that correlates with prostasin expression in these cells. Demethylation coupled with histone deacetylase inhibition resulted in reactivated expression of the prostasin mRNA in MDA‐MB‐231 and MDA‐MB‐435s cells. These results suggest that prostasin expression in breast cancer cells may be regulated by DNA methylation and that an absence of prostasin expression may contribute to breast cancer invasiveness and metastatic potential. © 2001 Wiley‐Liss, Inc.
Significance of phosphotyrosine proteins, Bcl‐2 and p53 for apoptosis in resting b‐chronic lymphocytic leukemia (CLL) cells
Authors: Laytragoon‐Lewin Nongnit , Rossmann Eva D. , Castro Juan , Mellstedt Håkan
Published: August 2002

Signal transduction and apoptosis in B‐cell chronic lymphocytic leukemia (CLL) cells with a post‐germinal center (GC) phenotype were studied. Specific activation of the cells was induced by a combination of soluble anti‐CD40 monoclonal antibody and interleukin‐4 (CD40/IL‐4) and nonspecific activation with a combination of phytohemagglutinin, phorbol‐12‐myristate‐13‐acetate and ionomycin (chemical mixture). Less than 5% of these leukemia cells entered the cell cycle after activation, as indicated by the number of cells in G0/G1 phase. The protein tyrosine phosphorylation pattern and expression of the Bcl‐2 protein were specific in ex vivo CLL cells of each individual patient. Expression of the p53 protein was not detectable in these leukemia cells. Cross‐linking of the CD40/IL‐4 receptors on CLL cells significantly upregulated phosphotyrosine proteins and the p53 protein. In the presence of chemical mixture, downregulated phosphotyrosine proteins were detected. Alterations in Bcl‐2 expression were independent of cross‐linking with CD40/IL‐4 or chemical mixture. A high frequency of apoptotic cells was detected in cells that had downregulated phosphotyrosine proteins and Bcl‐2 protein. There was no correlation between induction of apoptosis and expression of p53 protein. Our results suggest that apoptosis in resting leukemia cells could occur prior to the cell cycle progression. Alterations in phosphotyrosine proteins and Bcl‐2 but not p53 might play an important role in the regulation of apoptosis in resting G0/G1 memory post‐GC B‐CLL cells. © 2001 Wiley‐Liss, Inc.
Three‐dimensional support function estimation and application for projection magnetic resonance imaging
Authors: Gregor Jens , Rannou Fernando R.
Published: August 2002

Magnetic resonance imaging (MRI) of nuclei that have very short relaxation times is conveniently based on spherical sampling. We have presented a least squares framework for reconstructing three‐dimensional (3D) source distribution images from such data. In this paper, we describe a practical algorithm for 3D support function estimation, which forms the basis for a method called focus of attention. By essentially identifying and eliminating equations and unknowns that merely represent background data, this data‐driven preprocessing scheme effectively reduces the computational burden associated with our algebraic approach to projection MRI. © 2002 John Wiley & Sons, Inc. Int J Imaging Syst Technol 12, 43–50, 2002
Maternal psychopathology and attachment in toddlers of heavy cocaine‐using mothers
Authors: Espinosa Michael , Beckwith Leila , Howard Judy , Tyler Rachelle , Swanson Krista
Published: August 2002

The purpose of this study is to examine the relationships among maternal psychopathology, early sensitive caregiving, and security of attachment in a sample of cocaine‐using women from environments with high contextual risks that include poverty, low educational attainment, minority status, and single parenthood. Thirty‐five women and their offspring participated in the study. Maternal psychopathology, including Axis I and Axis II disorders, was assessed during the prenatal period via a self‐report clinical measure. Maternal sensitivity was assessed at 1 month and 6 months postdelivery through rating scales. At 18 months postdelivery, toddlers' attachment to their mothers was assessed via the Strange Situation procedure. Also at 18 months, mothers' level of depression was assessed via a depression inventory. Maternal psychopathology during pregnancy was found to be associated with both early caregiving and attachment. Mothers demonstrating clinical levels of particular Axis II disorders provided less sensitive caregiving, and had toddlers who were more likely to be disorganized/disoriented in their attachments. For Axis I disorders, only clinical levels of prenatal dysthymia were found to be associated with a greater likelihood of secure attachment. ©2001 Michigan Association for Infant Mental Health.
The role of Seprafilm™ bioresorbable membrane in the prevention and therapy of endometrial synechiae
Authors: Tsapanos Vassilios S. , Stathopoulou Lavinia P. , Papathanassopoulou Vassiliki S. , Tzingounis Vassilios A.
Published: August 2002

This randomized controlled blind prospective study is undertaken to evaluate the safety and efficacy of Seprafilm™—a novel bioresorbable membrane of chemically modified hyaluronic acid and carboxymethylcellulose—in prevention and reduction of postoperative endometrial and endocervical synechiae formation after general suction evacuation or curettage for incomplete, missed, and recurrent abortion. In total, 150 patients with incomplete or missed abortion participated in the clinical study. The study population was divided into two main groups. In the treatment (Seprafilm™) group (n=50), application of Seprafilm™ membrane in the endometrial cavity and the cervical canal was used after the suction evacuation and/or the curettage. In the control group (n=100), nothing was inserted in the uterus. Both groups were divided into two subgroups: patients who had no previous suction or curettage, (with no previous D&C) (n=88), and patients who had at least one previous suction or curettage (with one or more previous D&C) (n=62). In the treatment (Seprafilm™) group, 32 patients had no previous D&C and 18 patients had one or more previous D&C. In the control group, 56 patients had no previous D&C and 44 patients had one or more previous D&C. Further fertility was estimated by pregnancy success in all groups. Endometrial synechiae formation was evaluated with the use of hysterosalpingography (HSG) in patients of all groups without pregnancy success 8 months after the intervention. Registering any adverse reaction and performing ultrasound controls assessed the safety of Seprafilm™ use. From the subgroup with no previous D&C, all 32 patients (100%) who received Seprafilm™ had a pregnancy in the following 8 months; in the controls, pregnancy occurred only in 54%. It was also demonstrated with hysterosalpingography (HSG) that patients with one or more previous interventions and no pregnancy 8 months later were adhesion free in 90% of the patients where Seprafilm™ was used, and only 50% in the untreated group. The membrane was tested on the endometrial area of the uterus and did not produce any adverse reaction. Ultrasound controls did not show any abnormal echoes. Intrauterine insertion of Seprafilm™ is safe, prevents the appearance of endocervical adhesions or endometrial synechiae after curettage, and reduces the area of the endometrial cavity occupied by them in a large percent of cases. It also seems that its use improves the possibility of a new pregnancy and fertility. © 2001 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 10–14, 2002
A biologically active VEGF construct in vitro: Implications for bioengineering‐improved prosthetic vascular grafts
Authors: Stone David , Phaneuf Matthew , Sivamurthy Nayan , LoGerfo Frank W. , Quist William C.
Published: August 2002

Prosthetic arterial grafts are unable to develop an intact endothelial lining after implantation, predisposing them to fail. Strategies have been sought to enhance endothelialization using growth factors and cytokines. This study assessed the biologic activity of vascular endothelial growth factor (VEGF) covalently linked to bovine serum albumin (BSA). Native and modified VEGF were assayed for endothelial cell migration and proliferation. Migration assays were performed comparing the effects of 2% fetal bovine serum (FBS), 50 ng/mL, 100 ng/mL, and 200 ng/mL of native VEGF and VEGF–BSA. Proliferation assays were performed by using Alamar Blue comparing cellular growth in 1% FBS, 10% FBS, 100 ng/mL unbound VEGF, and 100 ng/mL VEGF–BSA. VEGF is a potent chemotactic agent for endothelial cells in both unbound and bound states. Native VEGF solutions (50 ng/mL, 100 ng/mL, and 200 ng/mL) stimulated 23.9 cells/high power field (HPF), 35.3 cells/HPF, and 49.1 cells/HPF (p < 0.005). VEGF–BSA solutions stimulated 25.9 cells/HPF, 39.1 cells/HPF, and 69.0 cells/HPF (p < 0.001). VEGF–BSA and native VEGF supported similar increased cellular proliferation compared with 1% FBS media (p < 0.002). Modified VEGF retains its chemotactic and proliferative properties in vitro. These findings suggest that bare prosthetic surfaces lined with VEGF bound to a “basecoat” albumin may support endothelial cell proliferation and migration and thereby offer new strategies to improve graft patency. © 2001 Wiley Periodicals, Inc. J Biomed Mater Res 59: 160–165, 2002
What Does “Materiality” Really Mean?
Authors: Chewning Eugene G. , Higgs Julia L.
Published: August 2002

These days, auditors are more concerned than ever about what is “material.” SEC Staff Bulletin No.
99 listed qualitative factors to consider when determining materiality. It's worth re‐examining.
© 2002 Wiley Periodicals, Inc.
β‐ and γ‐actin genes differ in their mechanisms of down‐regulation during myogenesis
Authors: Lloyd Catriona , Gunning Peter
Published: August 2002

During the differentiation of myoblasts to form myotubes, the expression patterns of the different actin isoforms change. The cytoplasmic actins, β and γ, are down‐regulated and the muscle specific isoforms are up‐regulated. The region responsible for the down‐regulation of the β‐actin gene has been located in the 3′end of the gene. Since the β‐ and γ‐actin genes arose from a gene duplication (Erba et al. [1988] J. Cell. Biol. 8:1775–1789), it is possible that the region responsible for down‐regulation of the γ‐actin gene may also be in the 3′end of the gene. We have tested this by transfection of human γ‐actin gene constructs into myogenic C2 cells. To our surprise, we found that the region responsible for down‐regulation of the γ‐actin gene during differentiation is not in the 3′ end of the gene in contrast to that for β‐actin. Rather, we found that intron III is required for appropriate down‐regulation of γ‐actin during myogenesis. Intron III containing transcripts from the γ‐actin gene were also found to accumulate during myogenesis. We, therefore, propose that excision of intron III from the primary transcript is inhibited during myogenesis resulting in degradation of the RNA. Removal of intron III from the gene allows it to escape this regulatory mechanism. J. Cell. Biochem. 84: 335–342, 2002. © 2001 Wiley‐Liss, Inc.
Proline‐rich transcript of the brain (prtb) is a serum‐responsive gene in osteoblasts and upregulated during adhesion
Authors: Sommerfeldt Dirk W. , Zhi Jizu , Rubin Clinton T. , Hadjiargyrou Michael
Published: August 2002

To characterize the temporal expression of genes that play a functional role during the process of osteoblast adhesion, we used differential display (DD‐PCR) on mRNA isolated from attached vs. suspended osteoblasts. A 200‐bp fragment displaying upregulated expression after 30 and 60 min adhesion was isolated, sequenced, and showed 97% homology to prtb, previously showed to be expressed in mouse brain. Northern analysis confirmed a two‐fold increase in prtb message during adhesion to tissue culture polystyrene, both in the presence or absence of surface‐adsorbed serum proteins. Serum stimulation alone was also able to induce prtb expression, although to a lesser extent, in suspension cells. Strong prtb expression was also detected in both brain and bone of adult rats. Furthermore, prtb expression analysis during MC3T3‐E1 cell differentiation revealed high expression levels independent of proliferation (day 0–7), matrix maturation (day 7–14), and mineralization (day 14–31). Time course analysis of prtb expression during adhesion of sensitized osteoblasts to serum‐protein coated surfaces showed robust mRNA expression at 5 min post‐plating and a peak at 10 min. The two known serum‐inducible immediate early genes c‐fos and c‐jun showed similar expression kinetics, with c‐jun mRNA levels peaking at 15 min and c‐fos at 20 min. Based on these data, we hypothesize that prtb may function as an immediate early, serum‐responsive, and adhesion‐inducible gene with possible involvement in processes such as cell cycle control, adhesion, and proliferation. J. Cell. Biochem. 84: 301–308, 2002. © 2001 Wiley‐Liss, Inc.
Inhibition of PDGF‐stimulated and matrix‐mediated proliferation of human vascular smooth muscle cells by SPARC is independent of changes in cell shape or cyclin‐dependent kinase inhibitors
Authors: Motamed Kouros , Funk Sarah E. , Koyama Hidenori , Ross Russell , Raines Elaine W. , Sage E. Helene
Published: August 2002

Interactions among growth factors, cells, and extracellular matrix regulate proliferation during normal development and in pathologies such as atherosclerosis. SPARC (secreted protein, acidic, and rich in cysteine) is a matrix‐associated glycoprotein that modulates the adhesion and proliferation of vascular cells. In this study, we demonstrate that SPARC inhibits human arterial smooth muscle cell proliferation stimulated by platelet‐derived growth factor or by adhesion to monomeric type I collagen. Binding studies with SPARC and SPARC peptides indicate specific and saturable interaction with smooth muscle cells that involves the C‐terminal Ca2+‐binding region of the protein. We also report that SPARC arrests monomeric collagen‐supported smooth muscle cell proliferation in the late G1‐phase of the cell cycle in the absence of an effect on cell shape or on levels of cyclin‐dependent kinase inhibitors. Cyclin‐dependent kinase‐2 activity, p107 and cyclin A levels, and retinoblastoma protein phosphorylation are markedly reduced in response to the addition of exogenous SPARC and/or peptides derived from specific domains of SPARC. Thus, SPARC, previously characterized as an inhibitor of platelet‐derived growth factor binding to its receptor, also antagonizes smooth muscle cell proliferation mediated by monomeric collagen at the level of cyclin‐dependent kinase‐2 activity. J. Cell. Biochem. 84: 759–771, 2002. © 2002 Wiley‐Liss, Inc.
Smoothelin contains a novel actin cytoskeleton localization sequence with similarity to troponin T
Authors: Quensel Christina , Krämer Jochen , Cardoso Maria Cristina , Leonhardt Heinrich
Published: August 2002

Smoothelin, a cytoskeletal protein, exists in a large isoform specifically expressed in vascular smooth muscle cells, and a small visceral isoform generated by a downstream transcriptional start site. Using fusions to the green fluorescent protein, we could show that both smoothelin isoforms are localized at actin containing filaments and mapped two domains that are each sufficient for localization at the actin cytoskeleton. The first domain is located in the vascular‐specific, N‐terminal half of smoothelin and the second in the common, C‐terminal half. The second domain shares clear sequence similarity with a domain of troponin T involved in actin filament association. These results suggest that the tissue‐specific expression of smoothelin isoforms might contribute to the different contractile properties of smooth muscle cells. J. Cell. Biochem. 85: 403–409, 2002. © 2002 Wiley‐Liss, Inc.
Molecular identification of NMDA glutamate receptors expressed in bone cells
Authors: Itzstein Cécile , Cheynel Hervé , Burt‐Pichat Brigitte , Merle Blandine , Espinosa Léon , Delmas Pierre D. , Chenu Chantal
Published: August 2002

The N‐methyl‐D‐aspartate (NMDA) subtype of the glutamate receptor has recently been identified in bone, but the molecular composition of this receptor expressed by bone cells is unknown. NMDA receptor (NMDAR) is a hetero‐oligomeric protein composed of two classes of subunits, the essential subunit NR1 and NR2A to D subunits that do not by themselves produce functional channels but potentiate NR1 activity and confer functional variability to the receptor. These subunits coassemble in different combinations to form functionally distinct NMDAR. In this study, we have investigated the molecular composition of NMDAR expressed by osteoblasts and osteoclasts in culture, using RT‐PCR analysis, in situ hybridization and immunocytochemistry. Specific probes were designed for the different subunits of the NMDAR, and we showed by RT‐PCR analysis that mammalian osteoclasts expressed NR2B and NR2D subunits mRNAs but not NR2A and NR2C mRNAs. Rat calvaria and MG63 osteoblastic cells also expressed several NR2 subunits mRNAs, namely NR2A, NR2B, and NR2D. In situ hybridization on isolated rabbit osteoclasts and MG63 cells has confirmed the localization of NR1, NR2B, and NR2D transcripts in osteoclasts and NR1, NR2A, NR2B, and NR2D transcripts in MG63 cells. The expression of NR2D protein by bone cells was shown by immunofluorescence. These results demonstrate for the first time that osteoblasts and osteoclasts express several NR2 subunits, suggesting a molecular diversity of NMDAR channels similar to what was shown for brain. The presence of distinct functional NMDAR on bone cells may be associated with various states of bone cell differentiation and function. J. Cell. Biochem. 82: 134–144, 2001. © 2001 Wiley‐Liss, Inc.
Non‐natural CBP2 binding peptides and peptomers modulate carcinoma cell adhesion and invasion
Authors: Hebert Carla , Coletta Ricardo D. , Norris Kathleen , Nikitakis Nikolaos , Lopes Marcio , Sauk John J.
Published: August 2002

A combinatorial approach that utilized a repertoire of bacteriophage‐peptides has identified a number of non‐natural CBP2 binding peptides. Moreover, co‐localization of some of these peptides with CBP2 in a number of tumor cell lines demonstrated that the peptides were directed to an intracellular location spatially coincident with the normal distribution of CBP2 [Sauk et al., 2000]. From among these sequences WHYPWFQNWAMA and LDSRYSLQAAMY were the most effective CBP2 binding peptides and best fulfilled the combinatorial motif containing deep hydrophobic pockets. When the hydropathic profiles of collagen α1(IV) and α2 (IV) were compared with these dodecapeptides, the hydropathic profiles of WHYPWFQNWAMA and LDSRYSLQAAMY closely matched those of α1(IV) 414–452 and α1(IV)531–543. These peptides were shown to be functional peptidomimics and possessed the ability to alter cell adhesion and invasion of human squamous cell carcinoma cell lines. Peptomers were formed of these non‐natural peptides to explore the role that a repetitive peptide may have on cell adhesion. The enhanced cell adhesion observed with the peptomers required both CBP2 antibodies and integrin antibodies for inhibition. The enhanced adhesion observed even in the face of combined antibody inhibition was consistent with such complexes possessing correspondingly slower dissociation rates. Thus, suggesting that peptomers may function in a like manner to multimeric peptide MHC complexes (tetramers) binding more than one cell receptor on a specific cell. These findings evoke both peptidomimics of native ligands and their peptomers as potential reagents by which to target tumor cells for chemotherapy, imaging, or retargeting viral vectors for gene therapy. J. Cell. Biochem. 82: 145–154, 2001. © 2001 Wiley‐Liss, Inc.
Iron‐induced oxidative stress up‐regulates calreticulin levels in intestinal epithelial (Caco‐2) cells
Authors: Núñez Marco T. , Osorio Andrea , Tapia Victoria , Vergara Alexander , Mura Casilda V.
Published: August 2002

Calreticulin, a molecular chaperone involved in the folding of endoplasmic reticulum synthesized proteins, is also a shock protein induced by heat, food deprivation, and chemical stress. Mobilferrin, a cytosolic isoform of calreticulin, has been proposed to be an iron carrier for iron recently incoming into intestinal cells. To test the hypothesis that iron could affect calreticulin expression, we investigated the possible associations of calreticulin with iron metabolism. To that end, using Caco‐2 cells as a model of intestinal epithelium, the mass and mRNA levels of calreticulin were evaluated as a function of the iron concentration in the culture media. Increasing the iron content in the culture from 1 to 20 μM produced an increase in calreticulin mRNA and a two‐fold increase in calreticulin. Increasing iron also induced oxidative damage to proteins, as assessed by the formation of 4‐hydroxy‐2‐nonenal adducts. Co‐culture of cells with the antioxidants quercetin, dimethyltiourea and N‐acetyl cysteine abolished both the iron‐induced oxidative damage and the iron‐induced increase in calreticulin. We postulate that the iron‐induced expression of calreticulin is part of the cellular response to oxidative stress generated by iron. J. Cell. Biochem. 82: 660–665, 2001. © 2001 Wiley‐Liss, Inc.
Regulated expression of GRP78 during vasopressin‐induced hypertrophy of heart‐derived myocytes
Authors: Brostrom Margaret A. , Mourad Fadi , Brostrom Charles O.
Published: August 2002

Although the development of cellular hypertrophy is widely believed to involve Ca2+ signaling, potential supporting roles for sequestered Ca2+ in this process have not been explored. H9c2 cardiomyocytes respond to arginine vasopressin with an initial mobilization of Ca2+ stores and reduced rates of mRNA translation followed by repletion of Ca2+ stores, up‐regulation of translation beyond initial rates, and the development of hypertrophy. Rates of synthesis of the endoplasmic reticulum (ER) chaperones, GRP78 and GRP94, were found to increase preferentially at early times of vasopressin treatment. Total GRP78 content increased 2‐ to 3‐fold within 8 h after which the chaperone was subject to post‐translational modification. Preferential synthesis of GRP78 and the increase in chaperone content both occurred at pM vasopressin concentrations and were abolished at supraphysiologic Ca2+ concentrations. Co‐treatment with phorbol myristate acetate decreased vasopressin‐dependent Ca2+ mobilization and slowed appearance of new GRP78 molecules in response to the hormone, whereas 24 h pretreatment with phorbol ester prolonged vasopressin‐dependent Ca2+ mobilization and further increased rates of GRP78 synthesis in response to the hormone. Findings did not support a role for newly synthesized GRP78 in translational up‐regulation by vasopressin. However up‐regulation, which does not depend on Ca2+ sequestration, appeared to expedite chaperone expression. This report provides the first evidence that a Ca2+‐mobilizing hormone at physiologic concentrations signals increased expression of GRP78. Translational tolerance to depletion of ER Ca2+ stores, typifying a robust ER stress response, did not accompany vasopressin‐induced hypertrophy. J. Cell. Biochem. 83: 204–217, 2001. © 2001 Wiley‐Liss, Inc.
Nuclear estrogen receptor II (nER‐II) is involved in the estrogen‐dependent ribonucleoprotein transport in the goat uterus I. Localization of nER‐II in snRNP
Authors: Sebastian Thomas , Thampan Raghava Varman
Published: August 2002

Exposure of goat uterine nuclei to estradiol in vitro results in an immediate exit of ribonucleoproteins (RNP) from the nuclei to the medium. This RNP exit appears to be mediated by an estrogen receptor localized in small nuclear ribonucleoproteins containing U1 and U2 snRNA. Available evidence indicates that the estrogen receptor involved is not the ERα, but an alternative form, which is also a 66 kDa protein. This is the nuclear estrogen receptor II (nER‐II) that has no DNA‐binding capacity. The transport is estrogen‐specific since non‐estrogenic steroids do not stimulate the transport of the RNP where the receptor is localized. J. Cell. Biochem. 84: 217–226, 2002. © 2001 Wiley‐Liss, Inc.
Isolation of transcriptionally active chromatin from human breast cancer cells using Sulfolink coupling gel chromatography
Authors: Sun Jian‐Min , Chen Hou Yu , Davie James R.
Published: August 2002

The process of transcription unfolds the nucleosome. The unfolded nucleosome structure will be maintained as long as the histones are in a highly acetylated state. Typically the cysteine residue at position 110 of histone H3 is buried in the interior of the nucleosome. However, the transcribed unfolded nucleosome has its H3 cysteine exposed, offering a tag to isolate and study transcribed nucleosomes. In this study, we applied Sulfolink Coupling Gel chromatography to isolate unfolded nucleosomes from estrogen dependent human cancer T5 cells. Inhibition of histone deacetylase activity did not enhance the yield of unfolded nucleosomes from these cells. We show that the estrogen receptor and c‐myc transcribed DNA sequences are associated with unfolded nucleosomes. In chromatin immunoprecipitation (ChIPs) assays, we found that the coding regions of the estrogen receptor and c‐myc genes are bound to highly acetylated H3 and H4 in cultured T5 Cells. We conclude that in cultured T5 breast cancer cells H3 and H4 are in highly acetylated states maintaining the unfolded structure of the transcribed nucleosome and facilitating subsequent rounds of elongation. J. Cell. Biochem. 84: 439–446, 2002. © 2001 Wiley‐Liss, Inc.
Just say no to psychotropic drugs!
Authors: Albee George W.
Published: August 2002

Prescribing drugs for mental disorders by psychologists means accepting an invalid model—the brain disease, biological‐defect explanation of psychopathology—that is advanced by political conservatives and accepted by some naive, well‐intentioned, but misinformed moderates who have not thought critically about the issue. Conservative psychiatry serves the ruling class by rejecting or ignoring the fact that most mental disorders are learned in the context of social and economic injustice, and familiar dysfunction. If we accept the fallacy of brain disease and genetic defect as the major causes of mental disorder and succeed in getting prescription privileges we will have sold our soul to the devil! © 2002 Wiley Periodicals, Inc. J Clin Psychol 58: 635–648, 2002.
Assessing basic HIV transmission risks and the contextual factors associated with HIV risk behavior in men who have sex with men
Authors: Suarez Troy , Kauth Michael R.
Published: August 2002

HIV/AIDS remains a substantial health threat to men who have sex with men. Although new HIV medications have provided great benefits for many HIV‐positive individuals, they have done little to protect HIV‐negative men. Consequently, changing one's sexual practices remains the most effective way to reduce risk for HIV. However, to develop an effective intervention for reducing HIV risk, it is important to fully understand risk behavior. In this article, we detail the essential elements for conducting an HIV risk assessment as well as those contextual factors that may support risk behaviors. Further, we discuss the importance of procuring an HIV test and the critical issues that may arise because of testing for HIV as well as the critical issues that may result from testing HIV‐positive. Finally, we illustrate how we integrate an HIV health risk assessment into a clinical interview. © 2001 John Wiley & Sons, Inc. J Clin Psychol/In Session 57: 655–669, 2001.
Insulin‐like growth factor (IGF) binding protein‐3 regulation of IGF‐I is altered in an acidic extracellular environment
Authors: Forsten Kimberly E. , Akers R. Michael , San Antonio James D.
Published: August 2002

While extracellular acidification within solid tumors is well‐documented, how reduced pH impacts regulation of insulin‐like growth factor‐I (IGF‐I) has not been studied extensively. Because IGF‐I receptor binding is affected by IGF binding proteins (IGFBPs), we examined how pH impacted IGFBP‐3 regulation of IGF‐I. IGF‐I binding in the absence of IGFBP‐3 was diminished at reduced pH. Addition of IGFBP‐3 reduced IGF‐I cell binding at pH 7.4 but increased surface association at pH 5.8. This increase in IGF‐I binding at pH 5.8 corresponded with an increase in IGFBP‐3 cell association. This, however, was not due to an increase in affinity of IGFBP‐3 for heparin at reduced pH although both heparinase III treatment and heparin addition reduced IGFBP‐3 enhancement of IGF‐I binding. An increase in IGF‐I binding to IGFBP‐3, though, was seen at reduced pH using a cell‐free assay. We hypothesize that the enhanced binding of IGF‐I at pH 5.8 is facilitated by increased association of IGFBP‐3 at this pH and that the resulting cell associated IGF‐I is IGFBP‐3 and not IGF‐IR bound. Increased internalization and nuclear association of IGF‐I at pH 5.8 in the presence of IGFBP‐3 was evident, yet cell proliferation was reduced by IGFBP‐3 at both pH 5.8 and 7.4 indicating that IGFBP‐3‐cell associated IGF‐I does not signal the cell to proliferate and that the resulting transfer of bound IGF‐I from IGF‐IR to IGFBP‐3 results in diminished proliferation. Solution binding of IGF‐I by IGFBP‐3 is one means by which IGF‐I‐induced proliferation is inhibited. Our work suggests that an alternative pathway exists by which IGF‐I and IGFBP‐3 both associate with the cell surface and that this association inhibits IGF‐I‐induced proliferation. © 2001 Wiley‐Liss, Inc.
Gap junctions, homeostasis, and injury
Authors: De Maio Antonio , Vega Virginia L. , Contreras Jorge E.
Published: August 2002

Gap junctions (Gj) play an important role in the communication between cells of many tissues. They are composed of channels that permit the passage of ions and low molecular weight metabolites between adjacent cells, without exposure to the extracellular environment. These pathways are formed by the interaction between two hemichannels on the surface of opposing cells. These hemichannels are formed by the association of six identical subunits, named connexins (Cx), which are integral membrane proteins. Cell coupling via Gj is dependent on the specific pattern of Cx gene expression. This pattern of gene expression is altered during several pathological conditions resulting in changes of cell coupling. The regulation of Cx gene expression is affected at different levels from transcription to post translational processes during injury. In addition, Gj cellular communication is regulated by gating mechanisms. The alteration of Gj communication during injury could be rationalized by two opposite theories. One hypothesis proposes that the alteration of Gj communication attenuates the spread of toxic metabolites from the injured area to healthy organ regions. The alternative proposition is that a reduction of cellular communication reduces the loss of important cellular metabolisms, such as ATP and glucose. © 2002 Wiley‐Liss, Inc.
Functional role of matrix metalloproteinases (MMPs) in mammary epithelial cell development
Authors: Lee Ping‐Ping H. , Hwang Jiuan‐Jiuan , Mead Lawrence , Ip Margot M.
Published: August 2002

The extracellular matrix (ECM) is an important regulator of mammary epithelial cell (MEC) function and is remodeled by matrix metalloproteinases (MMPs). To investigate the significance and regulation of MMP activity in normal MEC, we utilized a primary culture model in which rat MEC were grown three dimensionally within a reconstituted basement membrane (RBM) in defined serum‐free medium. Zymograms of culture medium demonstrated that five major gelatinases of 97, 80, 74, 69, and 65 kDa were secreted by MEC and were distinct from gelatinases of RBM origin. Based on molecular weight, p‐aminophenylmercuric acid activation, immunoblotting with MMP‐specific antibodies, inhibition by EDTA, a peptide containing the prodomain sequence of MMP (TMRKPRCGNPDVAN) and two synthetic MMP inhibitors (BB‐94 and CGS 27023A), these were classified as inactive and active forms of MMP‐9 and MMP‐2. The maximal MMP activities occurred when MEC were in a rapid proliferation and branching phase and declined after they underwent functional differentiation. Known regulators of MEC growth and differentiation were evaluated for their ability to modulate gelatinase activity in primary culture. Secretion of one or both MMPs was inhibited by EGF, TGFα, prolactin, and hydrocortisone and stimulated by progesterone. Furthermore, the functional significance of MMPs was demonstrated since three MMP inhibitors blocked branching morphogenesis elicited by the absence of hydrocortisone. Additionally, two synthetic MMP inhibitors not only inhibited epithelial cell growth but also inhibited normal alveolar development of the MEC. Finally, these drugs were found to enhance MMP secretion from MEC, although the activity of the secreted MMPs was inhibited as long as the drug was present. © 2001 Wiley‐Liss, Inc.
Functional characterization of P2Y and P2X receptors in human eosinophils
Authors: Idzko Marco , Dichmann Stefan , Panther Elisabeth , Ferrari Davide , Herouy Yared , Virchow, Jr. Christian , Luttmann Werner , Di Virgilio Francesco , Norgauer Johannes
Published: August 2002

Activation of purinoceptor by ATP induces in eosinophils various cell responses including calcium transients, actin polymerization, production of reactive oxygen metabolites, CD11b‐expression, and chemotaxis. Here, the effect of ion channel‐gated P2X and/or G protein‐coupled P2Y receptor agonists ATP, ATPγS, α,β‐meATP, 2‐MeSATP, BzATP, ADP, CTP, and UTP on the intracellular Ca2+‐mobilization, actin polymerization, production of reactive oxygen metabolites, CD11b expression and chemotaxis of human eosinophils were measured and the biological activity was analyzed. Although all tested nucleotides were able to induce all these cell responses, the biological activity of the analyzed nucleotides were distinct. Agonists of the G protein‐coupled P2Y receptors such as 2‐MeSATP, UTP, and ADP have a higher biological activity for production of reactive oxygen metabolites, actin polymerization and chemotaxis in comparison to the ion channel‐gated P2X agonists αβ‐meATP, BzATP, and CTP. In contrast, P2Y and P2X agonist showed similar potencies in respect to intracellular calcium transient and CD11b up‐regulation. This conclusion was further supported by experiments with receptor iso‐type antagonist KN62, EGTA or with the Gi protein‐inactivating pertussis toxin. These findings indicate participation of different purinorecptors in the regulation of cell responses in eosinophils. © 2001 Wiley‐Liss, Inc.
Functional stabilization of cellulase by covalent modification with chitosan
Authors: Darias Rodolfo , Villalonga Reynaldo
Published: August 2002

Chitosan was linked to cellulase (EC 3.2.1.4) from Trichoderma viride by covalent conjugation to periodate‐activated carbohydrate moieties of the enzyme. The modified enzyme contained about 1.5 mol of polymer per mol of protein. The specific activity of the conjugate prepared was 39.8% of the native cellulase. The optimum pH and temperature for cellulase remained unaltered after modification. The thermostability was increased by 8.9 °C for the cellulase–chitosan complex. Thermal inactivation at different temperatures ranging from 65 °C to 80 °C was markedly increased for the polymer‐modified enzyme. The stability within the pH range 1.0–3.2 was also improved for the modified enzyme.

© 2001 Society of Chemical Industry
Stabilization of penicillin V acylase from Streptomyces lavendulae by covalent immobilization
Authors: Torres‐Bacete Jesús , Arroyo Miguel , Torres‐Guzmán Raquel , Mata Isabel de la , Castillón M Pilar , Acebal Carmen
Published: August 2002

Penicillin V acylase from the actinomycete Streptomyces lavendulae ATCC 13664 has been immobilized to epoxy‐activated acrylic beads (Eupergit C®) by covalent binding. Further linkage of bovine serum albumin after enzyme immobilization was carried out in order to remove the remaining oxirane groups of the support. The obtained immobilized biocatalyst displayed double exponential deactivation kinetics at temperatures below 55 °C, while the native enzyme followed single exponential decay at the same temperatures. We concluded that soluble penicillin acylase was deactivated in one step, whereas the immobilized enzyme showed an enzymatic intermediate state which is highly thermostable. As a consequence of the immobilization process, the enzyme displayed a 10‐fold increase in its half‐life at 40 °C. At this temperature, the enzymatic intermediate state was progressively destabilized as the pH of the medium was increased. Thus, the optimum pH range for the immobilized enzyme preparation was established as being from 7.0 to 8.0. Higher pH values led to quicker enzyme deactivation.

© 2001 Society of Chemical Industry
Synthesis of n‐butyl phenyl ether by tri‐liquid‐phase catalysis using poly(ethylene glycol)‐600 as a catalyst – analysis of factors affecting the reaction in a batch reactor
Authors: Hsiao Hsu‐Chin , Weng Hung‐Shan
Published: August 2002

As the second part of a series of studies on the synthesis of n‐butyl phenyl ether (ROPh) by tri‐liquid‐phase catalysis, this work examines the factors affecting the reaction between n‐butyl bromide (RBr, organic substrate) and sodium phenolate (NaOPh, aqueous nucleophile) with poly(ethylene glycol)‐600 (PEG‐600) as a phase‐transfer catalyst. The reaction is performed in a batch reactor at 45–85 °C for 2 h while the agitation speed is fixed at 1000 rpm. Experimental results indicate that the individual mole fractions of NaOPh and PEG‐600 slightly affect the reaction, while the total amount of these components exerts significant influence. When the mole fraction of PEG‐600 is 0.5, the reaction rate and the conversion of RBr are the highest. No byproducts are formed in the course of the reaction. The system using a non‐polar organic solvent might obtain a higher conversion compared with a weakly polar one owing to a higher concentration of PEG‐600 in the third liquid phase. Furthermore, adding NaOH facilitates the reaction to obtain a higher reaction rate than adding other kinds of salt because the addition of a base results in the formation of a third liquid phase. The catalytic ability of PEG with average molecular weight of 600 gmol−1 is far higher than that with average molecular weight of 200, 400 and 1000 because PEG‐600 possesses an appropriate chain length which can tightly associate with Na+ to form the complex of PEG‐600‐Na+OPh− for reacting with RBr. In addition, this nucleophilic substitution reaction is found to be pseudo‐first‐order with respect to RBr.

© 2001 Society of Chemical Industry