bluuebunny/crossref_metadata_2025 huggingface dataset:
Involvement of MEKK1/ERK/P21Waf1/Cip1 signal transduction pathway in inhibition of IGF‐I‐mediated cell growth response by methylglyoxal
Authors: Du Jun , Cai Shaohui , Suzuki Haruhiko , Akhand Anwarul A. , Ma Xiuyang , Takagi Yoshikazu , Miyata. Toshio , Nakashima Izumi , Nagase Fumihiko
Published: March 2003

The abnormal accumulation of methylglyoxal (MG), a physiological glucose metabolite, is strongly related to the development of diabetic complications by affecting the metabolism and functions of organs and tissues. These disturbances could modify the cell response to hormones and growth factors, including insulin‐like growth factor‐1 (IGF‐I). In this study, we investigated the effect of MG on IGF‐I‐induced cell proliferation and the mechanism of the effect in two cell lines, a human embryonic kidney cell line (HEK293), and a mouse fibroblast cell line (NIH3T3). MG rendered these cells resistant to the mitogenic action of IGF‐I, and this was associated with stronger and prolonged activation of ERK and over‐expression of P21Waf1/Cip1. The synergistic effect of MG with IGF‐I in activation of ERK was completely abolished by PD98059 but not by a specific PI3K inhibitor, LY294002, or a specific PKC inhibitor, bisindolylmaleimide. Blocking of Raf‐1 activity by expression of a dominant negative form of Raf‐1 did not reduce the enhancing effect of MG on IGF‐I‐induced activation of ERK. However, transfection of a catalytically inactive form of MEKK1 resulted in inactivation of the MG‐induced activation of ERK and partial inhibition of the enhanced activation of ERK and over‐expression of p21Waf1/Cip1 induced by co‐stimulation of MG and IGF‐I. These results suggested that the alteration of intracellular milieu induced by MG through a MEKK1‐mediated and PI3K/PKC/Raf‐1‐independent pathway resulted in the modification of cell response to IGF‐I for p21Waf1/Cip1‐mediated growth arrest, which may be one of the crucial mechanisms for MG to promote the development of chronic clinical complications in diabetes. J. Cell. Biochem. 88: 1235–1246, 2003. © 2003 Wiley‐Liss, Inc.
The impact of organizational structure on time‐based manufacturing and plant performance
Authors: Nahm Abraham Y , Vonderembse Mark A , Koufteros Xenophon A
Published: March 2003

The innovation and organizational theory literatures argue that implementing radical innovation can be facilitated or hindered by the organization’s structural design. As firms attempt to cope with an external environment that is changing from industrial to post‐industrial, how do they implement change? This study develops a research framework that examines relationships among various structural dimensions (i.e. number of layers in the hierarchy, level of horizontal integration, locus of decision‐making, nature of formalization, and level of communication), time‐based manufacturing practices, and plant performance. Based on 224 responses from manufacturing firms, this study develops instruments to measure these organizational sub‐dimensions using part of this sample (N=104), and it tests the structural relationships with the remaining responses (N=120). Results indicate that the nature of formalization, the number of layers in the hierarchy, and the level of horizontal integration have significant, direct, and positive effects on the locus of decision‐making and level of communication. Locus of decision‐making and the level of communication, in turn, have significant, direct, and positive effects on time‐based manufacturing practices. Finally, time‐based manufacturing practices have a significant, direct, and positive impact on plant performance.
Adhesion of perichondrial cells to a polylactic acid scaffold
Authors: Giurea Alexander , Klein Travis J. , Chen Albert C. , Goomer Randal S. , Coutts Richard D. , Akeson Wayne H. , Amiel David , Sah Robert L.
Published: March 2003

The number of chondrogenic cells available locally is an important factor in the repair process for cartilage defects. Previous studies demonstrated that the number of transplanted rabbit perichondrial cells (PC) remaining in a cartilage defect in vivo, after being carried into the site in a polylactic acid (PLA) scaffold, declined markedly within two days. This study examined the ability of in vitro culture of PC/PLA constructs to enhance subsequent biomechanical stability of the cells and the matrix content in an in vitro screening assay. PC/PLA constructs were analyzed after 1 h, 1 and 2 weeks of culture. The biomechanical adherence of PC to the PLA scaffold was tested by subjecting the PC/PLA constructs to a range of flow velocities (0.25–25 mm/s), spanning the range estimated to occur under conditions of construct insertion in vivo. The adhesion of PC to the PLA carrier was increased significantly by 1 and 2 weeks of incubation, with 25 mm/s flow causing a 57% detachment of cells after 1 h of seeding, but only 7% and 16% after 1 and 2 weeks of culture, respectively (p > 0.001). This adherence was associated with marked deposition of glycosaminoglycan and collagen. These findings suggest that pre‐incubation of PC‐laden PLA scaffolds markedly enhances the stability of the indwelling cells. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Approaching Complex Cases With a Crisis Intervention Model and Teamwork: A Commentary
Authors: Scheyett Anna M.
Published: March 2003

This article is a response to the case of SA presented by O'Daniel and Wells. In this response I support the approach used with the patient, and discuss and expand on the applicability of a crisis intervention model to genetic counseling. In addition, I explore the issue of autonomy and informed decision making for patients who are in crisis. I also discuss the surface contradiction between the mandate for nondirectiveness and the need to provide direction during crisis intervention are discussed and reframe the issue as one of process versus content directiveness. I argue that during times of crisis, genetic counselors may need to direct process in order for patients to be able to make autonomous decisions.
Clinical, enzymatic, and molecular genetic characterization of a biochemical variant type of argininosuccinic aciduria: prenatal and postnatal diagnosis in five unrelated families
Authors: Kleijer W. J. , Garritsen V. H. , Linnebank M. , Mooyer P. , Huijmans J. G. M. , Mustonen A. , Simola K. O. J. , Arslan‐Kirchner M. , Battini R. , Briones P. , Cardo E. , Mandel H. , Tschiedel E. , Wanders R. J. A. , Koch H. G.
Published: March 2003

A biochemical variant of argininosuccinate lyase deficiency, found in five individuals, is introduced. In comparison to classical patients, the variant cases of argininosuccinate lyase deficiency were characterized by residual enzyme activity as measured by the incorporation of [14C]citrulline into proteins. The five patients of different ethnic backgrounds presented with relatively mild clinical symptoms, variable age of onset, marked argininosuccinic aciduria and severe, but not complete, deficiency of argininosuccinate lyase. [14C]Citrulline incorporation into proteins, which is completely blocked in classical argininosuccinic aciduria, was only partially reduced in fibroblasts of these patients. Further investigation showed that previous standard conditions of the assay were not optimal. Higher concentrations of citrulline in the incubation medium strongly stimulated 14C incorporation in normal cells, but not in the patients; as a result, the relative incorporation level in the patients dropped to 6–28% compared to 18–75% of normal in the original procedure. Prenatal diagnosis was successfully performed in three of the families. Affected pregnancies were indicated by (partial) deficiency of [14C]citrulline incorporation in chorionic villi and/or increased levels of argininosuccinate in amniotic fluid. Analysis of the ASL gene in the five patients revealed a considerable allelic heterogeneity. Three novel mutations—R385C (2 patients), V178M and R379C—were detected in homozygous states, whereas one patient was compound heterozygous for the known mutations R193Q and Q286R. In conclusion, there are patients of different ethnic backgrounds who are characterized by residual activity of argininosuccinate lyase and who present with less severe clinical courses. In addition, we present an improved biochemical assay for accurate prenatal and postnatal diagnosis.
Cytochrome oxidase deficiency in Lowe syndrome
Authors: Cifelli P. M. , Hargreaves I. , Grünewald S.
Published: March 2003

We report on a patient with complex IV deficiency who in later clinical course was diagnosed as a Lowe syndrome. Mitochondrial abnormalities can be present in Lowe syndrome and might lead to misdiagnosis, additionally because clinical features can be overlapping.
Iron-Induced Oxidative Stress in Erythrocyte Membranes of Non-Insulin-Dependent Diabetic Nigerians
Authors: Okunade Gbolahan W. , Odunuga Odutayo O. , Olorunsogo Olufunso O.
Published: March 2003

The presence of higher level of endogenous free radical reaction products in the erythrocyte ghost membrane (EGM) of Non-insulin-dependent diabetes mellitus (NIDDM) subjects compared with that of normal healthy controls has been demonstrated. The EGMs of NIDDM subjects were also shown to be more susceptible to exogenously generated oxidative stress than those of normal healthy individuals. The decreased level of reactive thiol groups in the EGM of NIDDM individuals supported this observation. We propose that the presence of significant levels of non-heme iron in the EGM of NIDDM subjects is an indication of the potential for iron-catalysed production of hydroxy and other toxic radicals which could cause continuous oxidative stress and tissue damage. Oxygen free radicals could therefore be responsible for most of the erythrocyte abnormalities associated with non-insulin-dependent diabetes and could indeed be intimately involved in the mechanism of tissue damage in diabetic complications.
Sendai Virus Fusion Activity as Modulated by Target Membrane Components
Authors: Nunes-Correia Isabel , Ramalho-Santos João , Pedroso de Lima Maria C.
Published: March 2003

We have studied the differences between erythrocytes and erythrocyte ghosts as target membranes for the study of Sendai virus fusion activity. Fusion was monitored continuously by fluorescence dequenching of R18-labeled virus. Experiments were carried out either with or without virus/target membrane prebinding. When Sendai virus was added directly to a erythrocyte/erythrocyte ghost suspension, fusion was always lower than that obtained when experiments were carried out with virus already bound to the erythrocyte/erythrocyte ghost in the cold, since with virus prebinding fusion can be triggered more rapidly. Although virus binding to both erythrocytes and erythrocyte ghosts was similar, fusion activity was much more pronounced when erythrocyte ghosts were used as target membranes. These observations indicate that intact erythrocytes and erythrocyte ghosts are not equivalent as target membranes for the study of Sendai virus fusion activity. Fusion of Sendai virus with both target membranes was inhibited when erythrocytes or erythrocyte ghosts were pretreated with proteinase K, suggesting a role of target membrane proteins in this process. Treatment of both target membranes with neuraminidase, which removes sialic acid residues (the biological receptors for Sendai virus) greatly reduced viral binding. Interestingly, this treatment had no significant effect on the fusion reaction itself.
Involvement of Glycolipid-Enriched Domains in the Transduction Mechanism of Neurotrophins in Cultured Neurons
Authors: Palestini P. , Masserini M. , Bottiroli G. , Brunner J. , Mutoh T. , Ferraretto A. , Ravasi D. , Pitto M.
Published: March 2003

Specialized domains, displaying a peculiar lipid and protein composition, are present within the plasma membrane of mammalian cells and play a pivotal role in fundamental membrane-associated events. Among lipids, sphingolipids (in particular glycolipids and sphingomyelin) are characteristically enriched within such domains. Moreover, a series of functionally related proteins is present, suggesting the involvement of these membrane structures in the mechanism of signal transduction and lipid/protein sorting. An increasing body of evidence suggests that domains are dynamic structures, and that their dynamic fluctuations can modulate the activity of domain-associated proteins through changes of glycolipid–protein interaction. Even if a large body of experimental investigation has been carried out on eukaryotic cells, only little attention has been paid to the neuron. The purpose of the present review is to summarize the observations implying a functional role of glycolipid-enriched domains in cultured rat cerebellar granule cells.
Matrix Metalloproteinase in Mammary Gland Remodeling-Modulation by Glycosaminoglycans
Authors: Sudhakaran P. R. , Ambili M. , Philip Susy
Published: March 2003

Mammary gland which undergoes proliferation, differentiation and involution in adult life is a useful model system to study the role of extracellular matrix (ECM) in regulating tissue specific functions. The involution that follows weaning results in the suppression of casein gene expression, collapse of alveolar structures and degradation of basement membrane as evidenced by biochemical analysis of matrix components like proteoglycans and collagen. Differential expression of three different MMPs viz. 130 K, 68 K and 60 K with varying specificity to Col IV of basement membrane and Col I of stroma, their selective inhibition by TIMP and proteoglycans and modulation by estrogen highlight the importance of these in the remodeling of the ECM in the mammary gland. The inhibition of these MMPs by glycosaminoglycans, particularly CS and change in the concentration of CS at different stages of mammary gland development suggests the existence of a novel mechanism for the regulation of the activity of MMPs at extracellular sites.
Glycosphingolipid Domains on Cell Plasma Membrane
Authors: Sorice Maurizio , Garofalo Tina , Misasi Roberta , Dolo Vincenza , Lucania Giuseppe , Sansolini Tiziana , Parolini Isabella , Sargiacomo Massimo , Torrisi Maria Rosaria , Pavan Antonio
Published: March 2003

In this study we analyzed by immunofluorescence, laser confocal microscopy, immunoelectron microscopy and label fracture technique the ganglioside distribution on the plasma membrane of several different cell types: human peripheral blood lymphocytes (PBL), Molt-4 lymphoid cells, and NIH 3T3 fibroblasts, which mainly express monosialoganglioside GM3, and murine NS20Y neuroblastoma cells, which have been shown to express a high amount of monosialoganglioside GM2. Our observations showed an uneven distribution of both GM3 and GM2 on the plasma membrane of all cells, confirming the existence of ganglioside-enriched microdomains on the cell surface. Interestingly, in lymphoid cells the clustered immunolabeling appeared localized over both the microvillous and the nonvillous portions of the membrane. Similarly, in cells growing in monolayer, the clusters were distributed on both central and peripheral regions of the cell surface. Therefore, glycosphingolipid clusters do not appear confined to specific areas of the plasma membrane, implying general functions of these domains, which, as structural components of a cell membrane multimolecular signaling complex, may be involved in cell activation and adhesion, signal transduction and, when associated to caveolae, in endocytosis of specific molecules.
Test Purification and the Evaluation of Differential Item Functioning with Multinomial Logistic Regression
Authors: Hidalgo-Montesinos M. Dolores , Gómez-Benito Juana
Published: March 2003

Summary We conducted a computer simulation study to determine the effect of using an iterative or noniterative multinomial logistic regression analysis (MLR) to detect differential item functioning (DIF) in polytomous items. A simple iteration in which ability is defined as total observed score in the test is compared with a two-step MLR in which the ability was purified by eliminating the DIF items. Data were generated to simulate several biased tests. The factors manipulated were: DIF effect size (0.5, 1.0, and 1.5), percentage of DIF items in the test (0%, 10%, 20% and 30%), DIF type (uniform and nonuniform) and sample size (500, 1000 and 2000). Item scores were generated using the graded response model. The MLR procedures were consistently able to detect both uniform and nonuniform DIF. When the two-step MLR procedure was used, the false-positive rate (the proportion of non-DIF items that were detected as DIF) decreased and the correct identification rate increased slightly. The purification process results in an improvement in the correct detection rate only in uniform DIF, large sample size, and large amount of DIF conditions. For nonuniform DIF there is no difference between the MLR-WP and MLR-TP procedures.
Cyp3a4 Inducible Model For In Vitro Analysis of Human Drug Metabolism Using A Bioartificial Liver
Authors: Iwahori Tohru , Matsuura Tomokazu , Maehashi Haruka , Sugo Ken , Saito Masaya , Hosokawa Masakiyo , Chiba Kan , Masaki Takahiro , Aizaki Hideki , Ohkawa Kiyoshi , Suzuki Tetsuro
Published: March 2003

CYP3A is responsible for approximately 50% of the therapeutic drug–metabolizing activity in the liver. The present study was undertaken to establish the CYP3A4 inducible model for analysis of human drug metabolism using a bioartificial liver composed of the functional hepatocellular carcinoma cell (HCC) line FLC–5. A radial–flow bioreactor (RFB), which is a carrier–filled type bioreactor, was used for 3–dimensional perfusion culture of FLC–5 cells. The CYP3A4 messenger RNA (mRNA) expression level 48 hours after rifampicin treatment in the RBF was approximately 100 times higher than that in a monolayer culture. Western blot analysis also demonstrated an increase in expression of the CYP3A protein. When testosterone, a substrate for CYP3A4, was added to the rifampicin–treated cell culture, 6β–hydroxy testosterone as a metabolite was formed. Electrophoretic mobility shift assay (EMSA) with a CYP3A4 ER6 probe demonstrated that relatively high molecular weight complex containing pregnane X receptor (PXR)/retinoid X receptorα(RXRα), compared with that in the monolayer culture, is possibly generated in the RFB culture of FLC–5 treated with rifampicin. Similarly, the assay with a probe of HNF–4α–binding motif indicated the formation of a large protein complex in the RFB culture. Because it is known that PXR transactivates CYP3A4 gene via its response element and expression of PXR is regulated by HNF–4α, the large complexes binding to response elements of PXR or HNF–4α in the RFB culture may contribute to up–regulation of CYP3A4 mRNA. In conclusion, the bioartificial liver composed of human functional HCC cell line was useful in studying drug interactions during induction of human CYP3A4.
Ribavirin and Interferon Is Effective for Hepatitis C Virus Clearance in Hepatitis B and C Dually Infected Patients
Authors: Liu Chun-Jen , Chen Pei-Jer , Lai Ming-Yang , Kao Jia-Horng , Jeng Yung-Ming , Chen Ding-Shinn
Published: March 2003

Ribavirin and interferon (IFN) are an effective treatment in 30% to 60% of patients with chronic hepatitis C. Whether they are also effective in dually infected patients with hepatitis B and C is unknown. Twenty–four patients with chronic hepatitis seropositive for both hepatitis B surface antigen and antibody to HCV received ribavirin 1,200 mg daily for 6 months, together with 6 million units (MU) IFN–α 2a thrice weekly for 12 weeks and then 3 MU for another 12 weeks. Serum HCV RNA was positive in 21 patients (group I, serum HBV DNA positive in 17 patients) and negative in 3 patients (group II, all HBV DNA positive) by Amplicor (Cobas Amplicor Monitor, Roche Diagnostics, Branchburg, NJ). Serum alanine aminotransferase (ALT), HCV RNA, and hepatitis B virus (HBV) DNA were monitored regularly for 12 months. Another 30 patients with chronic hepatitis C alone receiving the same regimen, served as controls. The serum HCV clearance rate in group I patients (43%) was comparable with that in controls (60%, P = .63) 24 weeks posttreatment. The serum ALT normalization rate in group I and group II patients was 43% and 0%, respectively, 24 weeks posttreatment. After treatment, resurgence of HBV and HCV was encountered in 4 group I patients and 1 group II patient, respectively. In conclusion, in hepatitis B and C dually infected patients, combination of IFN with ribavirin can achieve a sustained HCV clearance rate comparable with hepatitis C alone. In dually infected patients, the treatment may alter the dominant, ruling hepatitis virus.
Significance of Hepatitis B Genotype in Acute Exacerbation, Hbeag Seroconversion, Cirrhosis–Related Complications, and Hepatocellular Carcinoma
Authors: Yuen Man-Fung , Sablon Erwin , Yuan He-Jun , Wong Danny Ka-Ho , Hui Chee-Kin , Wong Benjamin Chun-Yu , Chan Annie On-On , Lai Ching Lung
Published: March 2003

The pathologic role of hepatitis B virus (HBV) genotype in Chinese patients with HBV infection is largely unknown. We examined the relationship between HBV genotypes, and hepatitis B e antigen (HBeAg) seroconversion, acute exacerbation, cirrhosis–related complications, and precore/core promoter mutations. Three hundred forty–three HBV patients (288 were asymptomatic, 55 presented with cirrhosis–related complications) were recruited. HBV genotypes and precore/core promoter mutations were determined by line probe assays. Genotypes B and C were the 2 most common genotypes, contributing 28% and 60%, respectively. The median age of HBeAg seroconversion for patients with genotype B was 9 years earlier than patients with genotype C (P = .011). There were no differences in the liver biochemistry, HBV DNA level, and cumulative risk of acute exacerbation (defined as increased alanine aminotransferase level ≥1.5 × upper limit of normal) between patients with genotypes B and C. There was a trend for patients with genotype B to have a higher cumulative rate of HBeAg seroconversion compared with patients with genotype C at the initial follow–up of 6 years (P = .053), but this difference became insignificant during subsequent follow–up. The prevalence of both genotypes was the same in patients with and without cirrhosis–related complications and/or hepatocellular carcinoma. Genotype B was associated with precore mutations (P < .0001), whereas genotype C was associated with core promoter mutations (P < .0001). In conclusion, although patients with genotype B had earlier HBeAg seroconversion, there was no significant reduction in the risk of development of complications. Genotypes B and C are associated with high prevalence of precore and core promoter mutations, respectively.
Mouse A6-Positive Hepatic Oval Cells Also Express Several Hematopoietic Stem Cell Markers
Authors: Petersen Bryon E. , Grossbard Brian , Hatch Heather , Pi Liya , Deng Jie , Scott Edward W.
Published: March 2003

Hepatic oval cells (HOC) are thought to be a type of facultative stem cell that arises as a result of certain forms of hepatic injury. A new and more efficient model has been established to activate the oval cell compartment in mice by incorporating 3,5–diethoxycarbonyl–1,4–dihydro–collidine (DDC) in a standard chow at a concentration of 0.1%. At the present time, very few markers exist for the mouse oval cells. One accepted marker is A6, an uncharacterized epitope recognized by mouse hepatic oval cells and it is accepted to be an oval cell marker. Sca–1 is a cell surface marker used to identify hematopoietic stem cells in conjunction with Thy–1+, CD34+, and lineage–specific markers. Both the CD34 and Sca–1 antigens are not normally expressed in adult liver, but are expressed in fetal liver, presumably on the hematopoietic cells. We report herein that mouse oval cells express high levels of Sca–1 and CD34, as well as CD45 surface proteins. Immunohistochemistry revealed that the cells expressing Sca–1/CD34/CD45 were indeed oval cells because they co–expressed the oval cell-specific marker A6 (94.57% ± 0.033%), as well as alpha–fetoprotein (AFP) (75.92% ± 0.071%). By using Sca–1 antibody in conjunction with magnetic activated cell sorting (MACS), followed with a flow cytometric cell sorting (FACS) method for CD34 and CD45, we have developed a rapid oval cell isolation protocol with high yields of greater than 90%. In conclusion, we have an efficient murine model for the production and isolation of large numbers of highly purified oval cells. Our system works with most strains of mouse, which will facilitate both in vivo and in vitro studies of mouse hepatic oval cells.
Interferon Alfa Regulated Gene Expression in Patients Initiating Interferon Treatment for Chronic Hepatitis C
Authors: Ji Xuhuai , Cheung Ramsey , Cooper Stewart , Li Qingqin , Greenberg Harry B. , He Xiao-Song
Published: March 2003

Interferon alfa (IFN–α) is an approved therapeutic agent for chronic hepatitis C. To directly characterize the effects of IFN–α in humans, we used microarrays to profile gene expression in peripheral blood mononuclear cells (PBMCs) from hepatitis C patients treated with IFN–α. Seven patients were studied using two strategies: (1) in vivo: PBMCs were collected immediately before the first dose of IFN–α, and 3 and 6 hours after the dose; (2) ex vivo: PBMCs that were collected before the first IFN–α dose were incubated with IFN–α for 3 and 6 hours. The microarray datasets were analyzed with significance analysis of microarrays (SAM) to identify genes regulated by IFN–α. We identified 516 named genes up–regulated at least 2–fold, at a false discovery rate (FDR) of less than 1%. In vivo and ex vivo studies generated similar results. No genes were identified as regulated differently between these 2 experimental conditions. The up–regulated genes belonged to a broad range of functional pathways and included multiple genes thought to be involved in the direct antiviral effect of IFN–α. Of particular interest, 88 genes directly relating to functions of immune cells were up–regulated, including genes involved in antigen processing and presentation, T–cell activation, lymphocyte trafficking, and effector functions, suggesting that IFN–α up–regulates multiple genes involving different aspects of immune responses to enhance immunity against hepatitis C virus. In conclusion, IFN–α-inducible genes can be identified in human PBMCs in vivo as well as ex vivo. Signature changes associated with different treatment outcomes may be found among these genes.
Oral Bile Acids Reduce Bacterial Overgrowth, Bacterial Translocation, and Endotoxemia in Cirrhotic Rats
Authors: Lorenzo-Zúñiga Vicente , Bartolí Ramón , Planas Ramón , Hofmann Alan F. , Viñado Belén , Hagey Lee R. , Hernández José M. , Mañé Josep , Alvarez Marco A. , Ausina Vicente , Gassull Miquel Angel
Published: March 2003

Experiments were performed to test whether conjugated bile acid administration would decrease bacterial overgrowth, bacterial translocation, and endotoxemia in ascitic cirrhotic rats. Cholylsarcosine, a deconjugation–dehydroxylation resistant and cholylglycine, a deconjugation–dehydroxylation susceptible bile acid were used. Rats with CCl4–induced cirrhosis and ascites were fed cholylsarcosine, cholylglycine (both at 70 mg/kg/d), or placebo for 2 weeks. Healthy rats, as controls, were treated similarly. In cirrhotic rats receiving placebo, bile secretion from an acute biliary fistula was lower than in healthy rats (27.2 ± 6.5 vs. 53.0 ± 3.1 μL/kg/min; mean ± SE, P< .05). The administration of conjugated bile acids to cirrhotic rats normalized bile secretion (cholylsarcosine, 51.8 ± 6.29; cholylglycine, 52.72 ± 8.9 μL/kg/min). Total ileal bacterial content was 6–fold higher in ascitic cirrhotic rats than in healthy rats. Conjugated bile acid administration reduced bacterial content to normal levels. Bacterial translocation was less in cirrhotic animals receiving conjugated bile acids (cholylsarcosine, 33%; cholylglycine, 26%) than in animals receiving placebo (66%). Endotoxemia was decreased in cirrhotic rats by conjugated bile acid feeding (cholylsarcosine, 0.098 ± 0.002; cholylglycine 0.101 ± 0.007 EU/mL) compared with placebo (0.282 ± 0.124, P < .001). Survival was greater in animals receiving conjugated bile acids (cholylsarcosine, 10/15; cholylglycine, 11/15; placebo, 5/15). In conclusion, the administration of conjugated bile acids to ascitic cirrhotic rats increased bile acid secretion, eliminated intestinal bacterial overgrowth, decreased bacterial translocation, decreased endotoxemia, and increased survival. Oral conjugated bile acids may be useful in preventing bacterial translocation, endotoxemia, and spontaneous bacterial perotonitis in cirrhotic patients.
Making friends with your data: Improving how statistics are conducted and reported1
Authors: Wright Daniel B.
Published: March 2003

Aim: This paper highlights some of the areas where there are problems with the way that statistics are conducted and reported in psychology journals. Recommendations are given for improving these problems.

Sample: The choice of topics is based largely on the questions that authors, reviewers, and editors have asked in recent years. The focus is on null hypothesis significance testing (NHST), choosing a statistical test, and what should be included in results sections.

Results: There are several ways to improve how statistics are reported. These should improve both the authors' and the readers' understanding of the data.

Conclusions: Psychology as a discipline will improve if the way in which statistics are conducted and reported is improved. This will require effort from authors, scrutiny from reviewers, and stubbornness from editors.
Pretreatment of bone with osteoclasts affects phenotypic expression of osteoblast‐like cells
Authors: Boyan B. D. , Schwartz Z. , Lohmann C. H. , Sylvia V. L. , Cochran D. L. , Dean D. D. , Puzas J. E.
Published: March 2003

Implant surface morphology regulates osteoblast phenotypic expression. Osteoblast sensitivity to non‐biologic surfaces suggests that native bone surface features may also affect osteoblast response. To test this, MG63 osteoblast‐like cells were grown for 7 days on bovine cortical bone wafers pretreated with rat bone marrow osteoclasts for 0, 10 or 20 days. Response to osteoclast‐treated surfaces was compared to the response of MG63 cells to titanium surfaces with smooth and rough microtopographies. Cell number, differentiation (alkaline phosphatase activity and osteocalcin levels), and local factors (PGE2 and TGF‐β1) were measured in confluent cultures. Compared to culture on plastic, cell number was reduced on all three types of bone wafers; this effect was dose‐dependent with increasing resorption of the surface. Alkaline phosphatase specific activity was increased (P ⩽ 0.05) on all three surfaces compared with plastic, but this increase was not dependent on resorption time, indicating this parameter was sensitive to the surface (bovine bone vs. plastic) but not to osteoclast‐resorption. There was a direct correlation between the area of the bone surface resorbed and the amount of osteocalcin, TGF‐β1 and PGE2 (R2 = 0.8025, 0.8689, 0.8896, respectively). With 20 days of osteoclast pretreatment, there was a 20‐fold increase in osteocalcin over plastic and a 7‐fold increase over cultures on untreated bone wafers. Similar increases were found for TGF‐β1 and PGE2. Thus, surface changes resulting from osteoclast pretreatment have a strong effect on osteoblast phenotypic expression, and suggest that microtopography may play a role. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Evidence for Nitric Oxide Mediated Effects on Islet Hormone Secretory Phospholipase C Signal Transduction Mechanisms
Authors: Åkesson Björn , Lundquist Ingmar
Published: March 2003

We have investigated the putative role of nitric oxide (NO) as a modular of islet hormone release, when stimulated by the muscarinic receptor agonist–phospholipase C activator, carbachol, with special regard to whether the IP3-Ca2+ or the diacylglycerol-protein kinase C messenger systems might be involved. It was observed that the NO synthase (NOS) inhibitor NG-nitro-L-arginine methylester (L-NAME) markedly potentiated insulin release and modestly inhibited glucagon release induced by carbachol. Similarly, insulin release induced by the phorbol ester TPA (protein kinase C activator) was markedly potentiated. Glucagon release, however, was unaffected. Dynamic perifusion experiments with 45C2+-loaded islets revealed that the inhibitory action of L-NAME on carbachol-stimulated NO-production was reflected in a rapid and sustained increase in insulin secretion above carbachol controls, whereas the 45Ca2+-efflux pattern was similar in both groups with the exception of a slight elevation of 45C2+ in the L-NAME-carbachol group during the latter part of the perifusion. No difference in either insulin release or 45Ca2+-efflux pattern between the carbachol group and L-NAME-carbachol group was seen in another series of experiments with identical design but performed in the absence of extracellular Ca2+. However, it should be noted that in the absence of extracellular Ca2+ both 45Ca2+-efflux and, especially, insulin release were greatly reduced in comparison with experiments in normal Ca2+. Further, in the presence of diazoxide, a potent K+ATP-channel opener, plus a depolarizing concentration of K+ the NOS-inhibitor L-NAME still markedly potentiated carbachol-induced insulin release and inhibited glucagon release. The enantiomer D-NAME, which is devoid of NOS-inhibitory properties, did not affect carbachol-induced hormone release. TPA-induced hormone release in depolarized islets was not affected by either L-NAME or D-NAME. The pharmacological intracellular NO donor hydroxylamine dose-dependently inhibited insulin release stimulated by TPA. Furthermore, a series of perifusion experiments revealed that hydroxylamine greatly inhibited carbachol-induced insulin release without affecting the 45Ca2+-efflux pattern. In summary, our results suggest that the inhibitory effect of NO on carbachol-induced insulin release is not to any significant extent exerted on the IP3-Ca2+ messenger system but rather through S-nitrosylation of critical thiol-residues in protein kinase C and/or other secretion-regulatory thiol groups. In contrast, the stimulating action of NO on carbachol-induced glucagon release was, at least partially, connected to the IP3-Ca2+ messenger system. The main effects of NO on both insulin and glucagon release induced by carbachol were apparently exerted independently of membrane depolarization events.
Enhanced Responsiveness of the Myocardial β-Adrenoceptor-Adenylate Cyclase System in the Perfused Rat Heart (I)
Authors: Gordeladze J. O. , Jynge I. , Borchgrevink P. C. , Sellevold O. F. M.
Published: March 2003

Crude myocardial sarcolemmal membrane fractions were prepared from rat hearts subjected to total global ischemia with and without normoxic reperfusion, or global anoxic (N2) perfusion with and without normoxic reperfusion. The direct effects on β-adrenenoceptor number, G-protein levels and stimulation of the adenylate cyclase (AC) complex were assessed.

In terms of AC activation, ischemia led to a marked increase (4-fold) in sensitivity to terbutaline (β2-agonist) and phorbol ester (tetradecanoyl phorbal acetate = TPA) stimulation, whereas the dobutamine (β1) responsiveness and Gpp(NH)p activation through GSα/Gi2α remained unaltered. However, forskolin-elicited holoenzyme activity fell markedly during normoxic reperfusion. Ischemia did not change the β1-adrenoceptor number, while β2-receptor population increased by approximately 45%. Western blots of myocardial GSA and Gi2α contents revealed that ischemia selectively diminished Gi2α levels only by some 50–70%.

Contrastingly, anoxia selectively increased the AC sensitivity (2-fold) to β1-adrenergic stimulation. As subsequent to ischemia, anoxia also increased the sensitivy to TPA stimulation, however, only 2-fold. Gpp(NH)p activation was unchanged, while forskolin-enhanced activity gradually declined, also during ensuing normoxic reperfusion. Anoxia brought about a 75% enhancement in β1-receptor number, while β2-receptors remained unaffected. However, altered receptor number normalized on termination of normoxic reperfusion. Finally, anoxia led to a 50–60% decimation of myocardial Gi2α levels, while GSα was only marginally reduced.

Despite the fact that the ischemia and anoxia effectuated a similar deterioration of physiological heart parameters, myocardial contents of energy rich phosphate moieties and loss of Gi2α, ischemia rendered the most profound increase in responsiveness of the sarcolemmal AC system.
Further Studies on Zn2+-Mediated Domain–Domain Communication in Human Erythrocyte Band 3
Authors: Xu Hong , Zhang Xujia , Yang Fu Yu
Published: March 2003

Human erythrocyte band 3 is purified and reconstituted into vesicles, forming right-side-out proteoliposomes. Zn2+ entrapped inside the proteoliposomes inhibits the anion transport activity of band 3, and removal of the cytoplasmic domain of band 3 is able to diminish Zn2+ inhibition. Thus, the inhibition of activity of band 3 results from the Zn2+ induced conformational change of the cytoplasmic domain, which in turn is transmitted to the membrane domain. The results of intrinsic fluorescence and its quenching by HB and the 35Cl NMR study indicate that the cytoplasmic domain is essential for the conformational change induced by Zn2+.SH-blocking reagents, CH3I and GSSG, are used to modify the cytoplasmic domain, where they specifically bind to Cys201 and Cys317. It is observed that the Zn2+ induced inhibition of anion transport activity is blocked. This demonstrates that Cys201 and Cys317 are required in Zn2+-mediated domain–domain communication.
The Identification of the Sodium Pump
Authors: Skou Jens Chr.
Published: March 2003

The identification of the sodium potassium pump as a Na+, K+-ATPase is described.
Uptake of the Herbicidal Glyphosate by Escherichia coli K-12
Authors: Cherepenko Elena , Karpenko Oksana
Published: March 2003

The uptake of the aminoacid biosynthesis inhibitor, used as the broad-spectrum herbicide ingredient, glyphosate (N-[phosphonomethyl]-glycine) was investigated in E. coli as a model to study mechanisms of cell resistance to antimetabolites as drugs and pesticides. Unlike the glyphosate-degrading Arthrobacter sp. strain for which the first successful measurement of glyphosate uptake and its inhibition by orthophosphate was reported [15], E. coli K-12 cannot take up this inhibitor either in the presence of orthophosphate, or after a prolonged starvation for it. However, cells made “competent” after an overnight cold CaCl2 exposure followed by dimethyl sulfoxide (DMSO) treatment could take up this compound (Km for glyphosate uptake, 274 μM). Neither amino acids, belonging to a single transport system, nor orthophosphate gave essential inhibition of glyphosate uptake by these cells.
Identification of the Putative Mannose 6-phosphate Receptor Protein (MPR 300) in the Invertebrate unio
Authors: Lakshmi Yerramalla Udaya , Radha Yalamarthy , Hille-Rehfeld Annette , von Figura Kurt , Kumar Nadimpalli Siva
Published: March 2003

In mammals, Mannose 6-phosphate receptor proteins (MPR 300 and MPR 46) mediate transport of lysosomal enzymes to lysosomes. Both receptors have been found in non-mammalian vertebrates including fish. To investigate the presence of MPRs in invertebrates, MPR 300 protein was isolated from the mollusc unio by affinity chromatography. It was shown to exhibit biochemical and immunological properties similar to mammalian MPR 300.
Selective Cytostatic and Neurotoxic Effects of Avermectins and Activation of the GABAα Receptors
Authors: Kokoz Yuri M. , Tsyganova Vera G. , Korystova Antonina F. , Grichenko Alexey S. , Zenchenko Konstantin I. , Drinyaev Victor A. , Mosin Vladimir A. , Kruglyak Elena B. , Sterlina Tatyana S. , Victorov Alexander V.
Published: March 2003

A natural avermectin complex, aversectin C, was shown to be capable of exerting selective cytostatic and neurotoxic effects on mammalian cells. Specifically, it killed proliferating neuroblastoma B103 cells but was non-toxic for differentiated cells of this culture. The anti-proliferation action of aversectin C was not inhibited by bicuculline or picrotoxin, antagonists of the GABAα receptors, and was partly due to the action of avermectin A1, a component of aversectin C. Aversectin C irreversibly suppressed activity of 60% neurons in medial septal slices of the rat brain. More than 55% of them were the GABAα- and B1-sensitive neurons whereas the rest, about 45% neurons, were the GABAα-insensitive and the neurotoxic effect of aversectin C was caused mainly by the B2 component.
Intradermal DNA Immunization: Antisera Specific for the Membrane Lectin MR60/ERGIC-53
Authors: Carrière Violaine , Landemarre Ludovic , Altemayer Valérie , Motta Geneviève , Monsigny Michel , Roche Annie-Claude
Published: March 2003

The trafficking of intracellular membrane proteins in Golgi apparatus, endoplasmic reticulum or intermediate compartment has not yet been fully elucidated. The human MR60/ERGIC-53 and the rat p58 proteins are one such protein; and to study them in cell-free and in situ systems, high quality monospecific antisera are required. Highly specific antisera have been obtained after immunization of mice with plasmids containing a gene encoding either the full length or a truncated protein. The best results were obtained after intradermal injections of a plasmid encoding a truncated protein comprising both the luminal carbohydrate recognition domain and the stem down to a cysteine residue close to the C-terminal end, but neither the transmembrane nor the cytosolic domains. Such antisera have a very high titer and are very efficient tools to visualize the MR60 protein in situ or to selectively precipitate the MR60 proteins from a whole cell lysate.
Evaluation of a Summer-School Program for Highly Gifted Secondary-School Students: The German Pupils Academy
Authors: Neber Heinz , Heller Kurt A.
Published: March 2003

Summary The German Pupils Academy (Deutsche Schüler-Akademie) is a summer-school program for highly gifted secondary-school students. Three types of program evaluation were conducted. Input evaluation confirmed the participants as intellectually highly gifted students who are intrinsically motivated and interested to attend the courses offered at the summer school. Process evaluation focused on the courses attended by the participants as the most important component of the program. Accordingly, the instructional approaches meet the needs of highly gifted students for self-regulated and discovery oriented learning. The product or impact evaluation was based on a multivariate social-cognitive framework. The findings indicate that the program contributes to promoting motivational and cognitive prerequisites for transforming giftedness into excellent performances. To some extent, the positive effects on students' self-efficacy and self-regulatory strategies are due to qualities of the learning environments established by the courses.
Teaching and Learning Psychological Assessment: Aspects of the Client's Question 1
Authors: Hagemeister Carmen , Westhoff Karl
Published: March 2003

Summary When psychologists are given a question by a client they have to decide if they have the necessary knowledge - and if the client's question meets legal, ethical, and professional standards. We constructed a checklist containing eight rules for the relevant decisions and investigated how well students of psychology applied those rules. Sixty-one students from two courses in psychological assessment performed two tests containing correct and incorrect client's questions. They took the first test at the beginning of the course and the second after treating the topic of client's questions; the pretest in one course was used as the posttest in the other course and vice versa. Between pretest and posttest, one session was spent discussing the solutions and reformulating incorrect questions. The students' overall performance significantly increased from 61% correct solutions in the pretest to 70% in the posttest. The increase in performance was significant for recognizing that it is illegal or unethical to work on a client's question or that a client's question is correct.
A Synthetic Peptide That Inhibits Lipoprotein(a) Assembly
Authors: Sharp Rebecca J. , Perugini Matthew A. , Marcovina Santica M. , McCormick Sally P.A.
Published: March 2003

Objective—

We previously reported that human apolipoprotein B100 (apoB) amino acids 4330–4397 were important for the initial noncovalent binding to apolipoprotein(a) [apo(a)] that facilitates lipoprotein(a) [Lp(a)] assembly. In this study, we aimed to further define the apoB sequences within the 4330–4397 region that were important for the noncovalent binding to apo(a).

Methods and Results—

Alignment of the human apoB4330–4397 sequence with mouse apoB, which also noncovalently binds apo(a), revealed stretches of similar sequence, including a lysine-rich sequence spanning apoB amino acids 4372–4392. Structural analysis of the apoB4372–4392 sequence using the WHEEL program predicted an amphipathic α-helix. Circular dichroism studies of a synthetic peptide spanning human apoB amino acids 4372–4392, both in the absence and presence of dimyristoylphosphatidylcholine, confirmed the α-helical nature of the sequence. We tested the ability of the apoB
4372–4392
peptide to bind to apo(a) and found that the peptide bound to apo(a) with high affinity but not to Lp(a). The apoB
4372–4392
peptide inhibited Lp(a) assembly in Lp(a) formation assays far more effectively than the lysine analogue, ε-amino-n-caproic acid (IC
50
=40 μmol/L versus 10 mmol/L, respectively). Incorporation of the apoB
4372–4392
peptide onto dimyristoylphosphatidylcholine vesicles yielded an even more effective inhibitor (IC
50
=4 μmol/L).

Conclusions—

Our study shows that the apoB4372–4392 sequence mediates the initial noncovalent binding to apo(a) and has demonstrated that the apoB
4372–4392
peptide is a novel and effective inhibitor of Lp(a) assembly.
When can a lack of structure facilitate strategic processing of information?
Authors: Willoughby Teena , Wood Eileen , Kraftcheck Erin R.
Published: March 2003

Background: Researchers examining the effectiveness of an elaboration strategy (answering ‘why’) for learning new information have been concerned with the familiarity of the materials and how that affects learning. It may be, however, that both how information is organised and familiarity impact on the potency of the strategy.

Aims: We examined the influence of presentation structures (i.e., organisation of information) on the effectiveness of an elaboration strategy.

Samples: All participants were undergraduates (78 females, 67 males) enrolled in a first‐year psychology course. Fifteen students participated in Experiment One, 42 students in Experiment Two, and 88 students in Experiment Three.

Methods: In Experiment One, preference for conceptual organisation was assessed. In Experiments Two and Three, students answered ‘why’ questions when different presentation structures were used.

Results: Students' preferred method of organisation did not match the imposed structure found in past research, suggesting that students may have been restricted in their ability to process the information distinctively. Students who were presented with the information in a random order achieved the largest memory scores.

Conclusions: When students have to reconstruct as well as encode the information, these added task demands provide an added benefit for learning.