bluuebunny/crossref_metadata_2025 huggingface dataset:
Corporate assets as a trust: for whom are corporate officers trustees in insolvency? the role of incentives in maintaining the trust
Authors: Davis Ronald B.
Published: July 2003

Uncertainty is a constant theme when corporations are in financial distress. Yet any successful restructuring of an insolvent corporation requires numerous stakeholders, including creditors, employees and suppliers, repose some degree of trust in those corporate officers who are trying to continue to operate the firm while restructuring it into a viable entity. This article looks at the issue of the positive and negative incentives that can be generated for corporate officers and directors from both their continuing control of corporate assets and their potential personal liability arising from corporate activity both before and after the corporation became insolvent. The potential role these incentives can play in providing a basis for the trust needed to meet the other governance challenges that arise in a restructuring is reviewed in the context of recent developments in Canada concerning the duties of corporate directors to creditors during insolvency. Also reviewed is the role of directors' insurance and indemnification in altering the incentives' effects on directors' behavior. Finally a critical appraisal is given of the present legal regime's provision for compromise of claims against corporate officers during restructuring, as well as the proposal to amend the law to allow complete exoneration of corporate directors from certain liabilities on insolvency. The article urges caution in altering the effects of incentives that may create the necessary basis for trust in the distressed corporation's officers amongst those stakeholders whose co‐operation is crucial to restructuring. Copyright © 2003 John Wiley & Sons, Ltd.
Changes in immunological and virological parameters in HIV‐1 infected subjects following leukapheresis
Authors: Boulassel M.R. , Spurll G. , Rouleau D. , Tremblay C. , Edwardes M. , Sekaly R.P. , Lalonde R. , Routy J‐P.
Published: July 2003

In order to assess immune responses during HIV‐1 therapeutic immunization, a large number of blood mononuclear cells (PBMC) are needed. Clinical tolerance and safety, as well as changes in immunological and virological parameters, were assessed, following leukapheresis in HIV‐1 infected subjects with CD4+ cell count >200 × 106/l. PBMC were collected using a Fenwal CS3000 cell separator in 29 subjects with mean CD4+ cell counts of 503 × 106/l (range 172–1,119) and viral load of 2.5 log10 copies/ml (range <1.7–5.4). Twenty‐four (83%) subjects were on antiretroviral therapy while 5 (17%) were untreated. The blood volume processed was 7 L over a period of 3 hours. A mean value (± standard error) of 82 ± 26 × 109/l lymphocytes was collected by a single apheresis in a mean volume of 200 ± 1.8 ml, containing 9.0 ± 1.3 × 109/l CD4+ and 10.2 ± 1.3 × 109/l CD8+ cells. The leukapheresis procedures were well tolerated and no immediate or delayed side effects were observed within 90 days of follow‐up. No changes from blood pre‐leukapheresis values were detected for white blood cells, lymphocytes, monocytes, CD8+, CD34+, naive and memory CD4+ cell counts immediately after, 1 h, 7 days, or within 90 days after leukapheresis. However, absolute CD4+ cell counts and percentage significantly increased from pre‐leukapheresis values after 1 h (530 ± 43 vs. 700 ± 75 cell × 106/l; 32.6 ± 1.6 vs. 36.9 ± 1.9%; P < 0.001 for both paired t‐tests) before returning to pre‐leukapheresis levels on day 7. No significant changes in viral load from pre‐leukapheresis levels in treated or untreated subjects were detected at any time points. We conclude that leukapheresis in HIV‐1 infected subjects with CD4+ cell counts >200 × 106/l is safe and induces a transient increase in the absolute and percentage of CD4+ cell count without enhancing viral replication. J. Clin. Apheresis 18:55–60, 2003. © 2003 Wiley‐Liss, Inc.
Clearance of fibrinogen and von Willebrand factor in serial double‐filtration plasmapheresis
Authors: Lin Su‐Mei , Yeh Jiann‐Horng , Lee Chin‐Cheng , Chiu Hou‐Chang
Published: July 2003

Double filtration plasmapheresis (DFP) is a widely used and effective way to clear autoantibodies from plasma. It can, however, transiently alter the hemostatic system and cause a bleeding tendency in some patients. There is limited data on the consecutive effect of serial DFP on the hemostatic system, especially on fibrinogen and von Willebrand factor (vWF) levels. This study measured fibrinogen and vWF serially before and after each session of DFP in 8 patients who received one course of DFP treatment for 3 to 5 consecutive sessions on an alternate‐day basis. In each session of DFP, the clearance rate of fibrinogen and vWF exceeded 63 and 45%, respectively. The final levels of fibrinogen and vWF after a full course of DFP were reduced to 14.3 and 51.2% of baseline level, respectively. No bleeding tendency was observed in any of the 34 DFP sessions. In conclusion, although an obvious decrease in fibrinogen level and the modest decrease in vWF were observed after an intensive course of DFP treatment, the low incidence of clinically important bleeding confirms the hemostasis‐related safety of DFP. J. Clin. Apheresis 18:67–70, 2003. © 2003 Wiley‐Liss, Inc.
Role of splenectomy in patients with refractory or relapsed thrombotic thrombocytopenic purpura
Authors: Aqui Nicole A. , Stein Steven H. , Konkle Barbara A. , Abrams Charles S. , Strobl Frank J.
Published: July 2003

Thrombotic thrombocytopenic purpura (TTP) was once uniformly fatal. Therapeutic plasma exchange in combination with immunosuppressive and anti‐platelet agents, however, have resulted in improved survival rates of greater than 80% for patients with TTP. In spite of aggressive plasma exchange and adjuvant therapy, a number of TTP patients are refractory to treatment. In addition, up to 40% of TTP patients who initially respond to therapy eventually relapse. Alternative therapies such as splenectomy have been used with varying degrees of success in refractory and relapsing TTP patients. The usefulness of splenectomy in preventing relapse of TTP or treating those patients who are refractory to plasma exchange remains controversial. We present a single institution's experience with 14 patients who underwent splenectomy for refractory (six patients) or relapsed (eight patients) TTP since 1984. In both patient groups, splenectomy induced stable long‐term remissions. Six of six (100%) patients who were refractory to plasma exchange, survived to be discharged from the hospital, apparently free of disease. Four of eight patients (50%) who had a splenectomy for relapsing TTP went into a complete remission and had no further relapses of their disease. Moreover, in relapsing patients who failed to experience long‐term remission, the relapse rate after splenectomy was 0.3 events per patient year compared to 1.0 events per patient year prior to splenectomy. We conclude that splenectomy is a reasonable treatment option for TTP patients refractory to standard plasma exchange therapy or who have experienced multiple and/or complicated relapses. We believe this is the first series that demonstrates efficacy of splenectomy in plasma exchange‐refractory TTP. J. Clin. Apheresis 18:51–54, 2003. © 2003 Wiley‐Liss, Inc.
Gfi‐1 attaches to the nuclear matrix, associates with ETO (MTG8) and histone deacetylase proteins, and represses transcription using a TSA‐sensitive mechanism
Authors: McGhee Laura , Bryan Josh , Elliott Liza , Grimes H. Leighton , Kazanjian Avedis , Davis J. Nathan , Meyers Shari
Published: July 2003

Gfi‐1 and Gfi‐1B can repress transcription and play important roles in hematopoietic cell survival and differentiation. Although these proteins are known to bind DNA through a C‐terminal zinc‐finger domain and may require an N‐terminal SNAG domain (SNAIL/Gfi‐1) to repress transcription, the mechanism by which Gfi‐1 and Gfi‐1B act is unknown. A first step towards understanding the mechanism by which these proteins repress transcription is to identify interacting proteins that could contribute to transcriptional repression. ETO (also termed MTG8), was first identified through its involvement in the (8;21) translocation associated with acute myelogenous leukemia. It attaches to the nuclear matrix and associates with histone deacetylases and the co‐repressors N‐CoR, SMRT, and mSin3A, and may act as a co‐repressor for site‐specific transcriptions factors. In this report we demonstrate that Gfi‐1 interacts with ETO and related proteins both in vitro and in vivo and with histone deacetylase proteins in vivo. We observed that a portion of Gfi‐1 and Gfi‐1B associated with the nuclear matrix, as is the case with ETO. Moreover, Gfi‐1 and ETO co‐localize to punctate subnuclear structures. When co‐expressed in mammalian cells, Gfi‐1 associates with histone deacetylse‐1 (HDAC‐1), HDAC‐2, and HDAC‐3. These data identify ETO as a partner for Gfi‐1 and Gfi‐1B, and suggest that Gfi‐1 proteins repress transcription through recruitment of histone deacetylase‐containing complexes. J. Cell. Biochem. 89: 1005–1018, 2003. © 2003 Wiley‐Liss, Inc.
Differential apoptosis‐inducing effect of quercetin and its glycosides in human promyeloleukemic HL‐60 cells by alternative activation of the caspase 3 cascade
Authors: Shen Shing‐Chuan , Chen Yen‐Chou , Hsu Feng‐Lin , Lee Woan‐Rouh
Published: July 2003

Flavonoids were demonstrated to possess several biological effects including antitumor, antioxidant, and anti‐inflammatory activities in our previous studies. However, the effect of glycosylation on their biological functions is still undefined. In the present study, the apoptosis‐inducing activities of three structure‐related flavonoids including aglycone quercetin (QUE), and glycone rutin (RUT; QUE‐3‐O‐rutinoside), and glycone quercitrin (QUI; QUE‐3‐O‐rhamnoside) were studied. Both RUT and QUI are QUE glycosides, and possess rutinose and rhamnose at the C3 position of QUE, respectively. Results of the MTT assay showed that QUE, but not RUT and QUI, exhibits significant cytotoxic effect on HL‐60 cells, accompanied by the dose‐ and time‐dependent appearance of characteristics of apoptosis including an increase in DNA ladder intensity, morphological changes, apoptotic bodies, and an increase in hypodiploid cells by flow cytometry analysis. QUE, but not RUT or QUI, caused rapid and transient induction of caspase 3/CPP32 activity, but not caspase 1 activity, according to cleavage of caspase 3 substrates poly(ADP‐ribose) polymerase (PARP) and D4‐GDI proteins, and the appearance of cleaved caspase 3 fragments being detected in QUE‐ but not RUT‐ or QUI‐treated HL‐60 cells. A decrease in the anti‐apoptotic protein, Mcl‐1, was detected in QUE‐treated HL‐60 cells, whereas other Bcl‐2 family proteins including Bax, Bcl‐2, Bcl‐XL, and Bag remained unchanged. The caspase 3 inhibitor, Ac‐DEVD‐FMK, but not the caspase 1 inhibitor, Ac‐YVAD‐FMK, attenuated QUE‐induced cell death. Results of DCHF‐DA assay indicate that no significant increase in intracellular peroxide level was found in QUE‐treated cells, and QUE inhibited the H2O2‐induced intracellular peroxide level. Free radical scavengers N‐acetyl‐cysteine (NAC) and catalase showed no prevention of QUE‐induced apoptosis. In addition, QUE did not induce apoptosis in an mature monocytic cell line THP‐1, as characterized by a lack of DNA ladders, caspase 3 activation, PARP cleavage, and an Mcl‐1 decrease, compared with those in HL‐60 cells. Our experiments provide evidence to indicate that the addition of rutinose or rhamnose attenuates the apoptosis‐inducing activity of QUE, and that the caspase 3 cascade but not free radical production is involved. J. Cell. Biochem. 89: 1044–1055, 2003. © 2003 Wiley‐Liss, Inc.
Adenosine inhibits activation‐induced T cell expression of CD2 and CD28 co‐stimulatory molecules: Role of interleukin‐2 and cyclic AMP signaling pathways
Authors: Butler Jared J. , Mader Jamie S. , Watson Carrie L. , Zhang Hong , Blay Jonathan , Hoskin David W.
Published: July 2003

Adenosine is an immunosuppressive molecule that is associated with the microenvironment of solid tumors. Mouse T cells activated with anti‐CD3 antibody in the presence of adenosine with or without coformycin (to prevent adenosine breakdown by adenosine deaminase) exhibited decreased tyrosine phosphorylation of some intracellular proteins and were inhibited in their ability to proliferate and synthesize interleukin (IL)‐2. In addition, adenosine interfered with activation‐induced expression of the co‐stimulatory molecules CD2 and CD28. Activation‐induced CD2 and CD28 expression was also diminished when T cells were activated in the presence of anti‐IL‐2 and anti‐CD25 antibodies to neutralize IL‐2 bioactivity. Collectively, these data suggest that CD2 and CD28 up‐regulation following T cell activation is IL‐2‐dependent; and that adenosine inhibits activation‐induced T cell expression of CD2 and CD28 by interfering with IL‐2‐dependent signaling. The inhibitory effect of adenosine on activation‐induced CD2 and CD28 expression could not be attributed to cyclic AMP (cAMP) accumulation resulting from the stimulation of adenylyl cyclase‐coupled adenosine receptors, even though cAMP at concentrations much higher than those generated following adenosine stimulation was inhibitory for both CD2 and CD28 expression. We conclude that adenosine interferes with IL‐2‐dependent T cell expression of co‐stimulatory molecules via a mechanism that does not involve the accumulation of intracellular cAMP. J. Cell. Biochem. 89: 975–991, 2003. © 2003 Wiley‐Liss, Inc.
N‐terminal methionine removal and methionine metabolism in Saccharomyces cerevisiae
Authors: Dummitt Benjamin , Micka William S. , Chang Yie‐Hwa
Published: July 2003

Methionine aminopeptidase (MetAP) catalyzes removal of the initiator methionine from nascent polypeptides. In eukaryotes, there are two forms of MetAP, type 1 and type 2, whose combined activities are essential, but whose relative intracellular roles are unclear. Methionine metabolism is an important aspect of cellular physiology, involved in oxidative stress, methylation, and cell cycle. Due to the potential of MetAP activity to provide a methionine salvage pathway, we evaluated the relationship between methionine metabolism and MetAP activity in Saccharomyces cerevisiae. We provide the first demonstration that yeast MetAP1 plays a significant role in methionine metabolism, namely, preventing premature activation of MET genes through MetAP function in methionine salvage. Interestingly, in cells lacking MetAP1, excess methionine dramatically inhibits cell growth. Growth inhibition is independent of the ability of methionine to repress MET genes and does not result from inhibition of synthesis of another metabolite, rather it results from product inhibition of MetAP2. Inhibition by methionine is selective for MetAP2 over MetAP1. These results provide an explanation for the previously observed dominance of MetAP1 in terms of N‐terminal processing and cell growth in yeast. Additionally, differential regulation of the two isoforms may be indicative of different intracellular roles for the two enzymes. J. Cell. Biochem. 89: 964–974, 2003. © 2003 Wiley‐Liss, Inc.
A reassessment of insulin‐like growth factor binding protein gene expression in the human retinal pigment epithelium
Authors: Yang Huaitao , Chaum Edward
Published: July 2003

The role of insulin‐like growth factors (IGF) in regulating cell differentiation and proliferation is in part modulated by the IGF binding protein (IGFBP) family of genes. Previous studies of the human retinal pigment epithelium (RPE) have detected expression of IGFBP‐2, ‐3, and ‐6. However, recent experiments in our lab have suggested a broader pattern of IGFBP gene family expression in the RPE cell than has previously been recognized. We have examined the gene expression profile of IGFBP‐1 to ‐6 and the related protein, IGFBP‐rP1, in RPE cell lines derived from ten donors eyes using RT‐PCR, ELISA, and Western methods. Transcripts of IGFBP‐1 to ‐6 and ‐rP1 were consistently detected in human RPE cells. IGFBP‐3, ‐5, ‐6, and ‐rP‐1, appear to be constitutively expressed in the RPE, whereas IGFBP‐1, ‐2, and ‐4, were expressed at variable levels in the cell lines examined. IGFBP secretion by the RPE in vitro was confirmed by ELISA (IGFBP‐1, ‐2, ‐3, ‐4, and ‐6) and Western blot analysis (IGFBP‐5 and ‐rP1). There was, in general, a strong correlation between gene‐specific transcription levels and protein secretion by the RPE. Our studies demonstrate that the major IGFBP family genes are ubiquitously expressed in explanted human RPE cells in vitro. This broad expression profile and the recent evidence that IGFBPs have IGF‐independent biological activity suggest that the IGFBP family genes may constitute a previously unrecognized and complex regulatory system in the human retina and RPE. J. Cell. Biochem. 89: 933–943, 2003. © 2003 Wiley‐Liss, Inc.
The establishment and characterization of an immortal cell line with a stable chondrocytic phenotype
Authors: King Karen B. , Kimura James H.
Published: July 2003

A cell line was developed from the transplantable Swarm rat chondrosarcoma (RCS) and has been maintained in continuous monolayer tissue culture for a number of years. This long term‐cultured (LTC) cell line exhibits the morphological and biochemical characteristics of chondrocytes and resembles the RCS tumor by electron and light microscopy. The cell line differs from the original tumor cells in that about 90% of the sulfated macromolecules are retained in the LTC extracellular matrix as compared to 30% by primary cultures of cells from the RCS tumor. An interesting and useful feature of this cell line is that it contains clonal populations of cells which differ in the quality and quantity of matrix produced. Two such clones serve to illustrate the diversity of cell types within the LTC cell line. One termed Rex accumulates an intensely staining matrix around it, while the other, Ng, accumulates a matrix, that remains virtually unstained. The chondrocytic nature and ease of cloning make these cells ideal for biochemical analysis of the chondrocyte and its extracellular matrix. J. Cell. Biochem. 89: 992–1004, 2003. © 2003 Wiley‐Liss, Inc.
Cytoprotection by pro‐vitamin C against ischemic injuries in perfused rat heart together with differential activation of MAP kinase family
Authors: Eguchi Masahiro , Fujiwara Mayumi , Mizukami Yoichi , Miwa Nobuhiko
Published: July 2003

The cardiac muscle cells are known to be killed by ischemia‐reperfusion (I/R) treatment that produce reactive oxygen species (ROS). We analyzed the function of the autooxidation‐resistant pro‐vitamin C, 2‐O‐alpha‐D‐glucosylated derivative (Asc2G) of ascorbic acid (Asc), in protecting against I/R injury of the heart in rat. The serum release of the intracellular enzyme CPK due to I/R injury decreased upon injection with Asc2G. Out of the mitogen‐activated protein (MAP) kinase family members, MAP kinase and JNK underwent the down‐regulation in contrast to up‐regulation of p38 compared with the I/R‐treated control in the absence of Asc2G. These data suggest important roles for differential activation of the MAP kinase family in cytoprotection against I/R injury by Asc2G. J. Cell. Biochem. 89: 863–867, 2003. © 2003 Wiley‐Liss, Inc.
The targets of vitamin D depend on the differentiation and activation status of CD4 positive T cells
Authors: Mahon Brett D. , Wittke Anja , Weaver Veronika , Cantorna Margherita T.
Published: July 2003

Vitamin D is a potent immune system regulator. The active form of vitamin D (1,25(OH)2D3) suppresses the development of animal models of human autoimmune diseases. 1,25(OH)2D3 decreased the proliferation of all T helper (h) cells and decreased the production of IFN‐γ, IL‐2, and IL‐5. In Th2 cells 1,25(OH)2D3 increased the production of IL‐4. Quiescent CD4+ T cells express vitamin D receptors but only at a low level, which increased five‐fold following activation. 1,25(OH)2D3 treatment of Th0 cells, but not Th1 or Th2 cells, induced the expression of the transcription factor GATA‐3. Microarray technology identified over 102 targets of 1,25(OH)2D3 in CD4+ T cells. Of the 102 genes, 57 genes were down‐regulated and 45 were up‐regulated by 1,25(OH)2D3 treatment of the CD4+ T cells. Two of the identified genes are regulators of NFkB. Other genes of interest included the IL‐2Rβ gene and IgE binding factor. Th2 and Th0 cells produced more IgE binding factor after treatment with 1,25(OH)2D3 while Th1 cell IgE binding factor expression was unaffected by 1,25(OH)2D3 addition. It is unclear why some of the genes identified are expressed in CD4+ T cells and furthermore why 1,25(OH)2D3 regulates the expression of these genes. Clearly CD4+ T cells can be direct targets of vitamin D. The targets of vitamin D in CD4+ T cells depend on the state of activation and differentiation status of the cells. J. Cell. Biochem. 89: 922–932, 2003. © 2003 Wiley‐Liss, Inc.
Comparison of stress induced by manual restraint and immobilisation in the estuarine crocodile, crocodylus porosus
Authors: Franklin Craig E. , Davis Bernie M. , Peucker S.K.J. , Stephenson H. , Mayer R. , Whittier J. , Lever J. , Grigg G.C.
Published: July 2003

This study compared the stress induced in captive estuarine crocodiles, Crocodylus porosus, by two different handling methods: manual restraint (noosing with ropes) and immobilization by electro‐stunning. To stun, a short charge (approx. 6 s) at 110 V was delivered to the back of the necks of C. porosus using a custom‐built device, which immobilized the animals for 5–10 min. Immobilized and restrained animals were measured and sexed, and the condition of the skin assessed. Blood samples were taken from some animals immediately after restraint or immobilization. Other animals were returned to their pens to recover for periods of 30 min, 1, 4, 12, 24 or 48 hours after which they were stunned and blood samples taken. Individual animals (mean body length 1.96 m, N=99) were bled only once. Haematocrit and haemoglobin concentrations were measured and plasma samples were analysed for corticosterone, glucose and lactate levels. Following restraint, there were significant increases in haematocrit, haemoglobin, glucose, lactate and corticosterone concentrations in C. porosus. For restrained animals, recovery to baseline levels occurred after approximately 8 hours. The stress response of stunned animals was significantly reduced compared to manually captured and restrained crocodiles. Both groups showed a significant increase in haematocrit, haemoglobin concentration and lactate levels, however the magnitude of change was significantly reduced, and recovery was faster in stunned animals. No increase in either glucose or corticosterone levels occurred with immobilisation. The results imply that immobilization by electro‐stunning is much less stressful. J. Exp. Zool. 298A:86–92, 2003. © 2003 Wiley‐Liss, Inc.
Influence of cortisol on osmoregulation and energy metabolism in gilthead seabream Sparus aurata
Authors: Laiz‐carrión Raúl , Martín Del Río María P. , Miguez Jesús M. , Mancera Juan M. , Soengas José L.
Published: July 2003

Gilthead seabream Sparus aurata were injected intraperitoneally with slow‐release implants of coconut oil alone or containing cortisol (50 and 100 µg.g−1 body weight), and sampled after two, five, and seven days to assess the simultaneous effects of cortisol on both osmoregulation and energy metabolism. Plasma cortisol levels increased in treated fish to 50–70 ng.ml−1. An enhanced hypoosmoregulatory capacity of cortisol‐implanted fish is suggested by the increase observed in gill Na+, K+‐ATPase activity, and the decrease observed in plasma ion concentration (Na+ and Cl−) and osmolality. Cortisol also elicited metabolic changes in liver (increased gluconeogenic potential suggested by elevated FBPase activity, and decreased potential of glycolysis and pentose‐phosphate shunt, suggested by the decreased activities of both PK and G6PDH) supporting changes in levels of plasma metabolites suitable for use in other tissues. Thus in this study, we demonstrate for the first time in fish that cortisol treatments elicit changes in the use of exogenous glucose in gills (decreased HK activity) and an increased glycolytic and glycogenic potential in brain (increased GPase, PK and PFK activities). J. Exp. Zool. 298A:105–118, 2003. © 2003 Wiley‐Liss, Inc.
Upgraded expression of 5S rRNA preludes the production of fibroin by spider glands
Authors: Vázquez Edwin , Arroyo Gerado , Cajigas Iván J. , Candelas Graciela C.
Published: July 2003

We have developed the large ampullate glands of the orb‐web spider Nephila clavipes as a model system in which to study the production of a tissue‐specific secretory protein. Through simple manipulations, the glands' fibroin production can be practically abolished and subsequently elicited into high levels of synthesis through a mechanical stimulus applied to the organism. The tissue specific responses evoked by the stimulus can be monitored through time‐course studies. The latter have revealed an orchestrated series of tissue and time specific macromolecular syntheses, which optimize the glandular tissues with components of the protein synthesis machinery. This work shows the upgraded accumulation of 5S rRNA in the glands as response to the stimulus within the earliest of the prelude events. Further enquiries on this accumulation must be conducted at the level of differential gene expressions, a chore we have initiated. A DNA fragment containing a single copy 5S rRNA gene has been isolated, cloned, sequenced, and transcribed in a cell‐free system. We enclose a discussion on the similarity between the genomic organization of this gene to that of a 5S rRNA gene of Bombyx mori. Our studies have revealed a considerable number of similarities in the silk production strategies of Nephila clavipes and the silkworm Bombyx mori, some of them rather unusual. J. Exp. Zool. 298A:128–133, 2003. © 2003 Wiley‐Liss, Inc.
Induction of pseudopregnancy in the American Black Bear (Ursus americanus)
Authors: Clamon Schulz Laura , Nelson Ralph A. , Pyter Leah M. , Bahr Janice M.
Published: July 2003

The aim of this study was to determine whether American Black Bears (Ursus americanus) can experience a pseudopregnancy of the same duration as pregnancy. To do this, we treated three nonmated, captive female bears with human chorionic gonadotropin (hCG) during one breeding season, and saline during another. Progesterone concentrations were measured in monthly blood samples to determine whether pseudopregnancy had occurred. Elevated progesterone concentrations were observed in two out of three bears treated with hCG. We conclude that 1) Elevated progesterone concentrations can be induced in black bears by injection of 35 U/kg hCG during the mating season. 2) Bears can experience a pseudopregnancy, identical in length to pregnancy, in which progesterone profiles are indistinguishable from those of pregnancy. J. Exp. Zool. 162–166, 2003. © 2003 Wiley‐Liss, Inc.
Effect of temperature on gene expression of the Gh/Igf system during embryonic development in rainbow trout (Oncorhynchus mykiss)
Authors: Gabillard Jean‐Charles , Rescan Pierre‐Yves , Fauconneau Benoit , Weil Claudine , Le Bail Pierre‐Yves
Published: July 2003

In fish, the GH/IGF system installs very early during development suggesting that this system could promote embryonic growth and development. In contrast to mammals, the embryonic growth rate of poikilotherms depends considerably on the incubation temperature. Therefore, the aim of this study was to determine if variations of embryo growth in response to temperature could be associated with modifications in the gene expression of the GH/IGF system.

In this study, using whole mount in situ hybridisation, we demonstrated that embryo incubation temperature (4, 8, and 12°C) did not change the timing of GH–1 and GH–2 mRNA expression in somatotroph cells (stage 24). Similarly, at hatching (stage 30), we did not observe an obvious difference in GH protein and GH–1 and GH–2 transcript amounts in relation to the incubation temperature. Furthermore, from stage 22 to 25, the highest temperature led to a specific up‐regulation of IGF–2 (2–fold between 4 and 12°C), and both IGF‐RIa and IGFRIb mRNA (1.5–fold between 4 and 12°C), while no difference was observed for IGF–1 mRNA. Conversely, at hatching, the highest temperature specifically down‐regulated IGF–2 (3fold between 4 and 12°C) and both IGF receptor mRNAs (2 fold between 4 and 12°C) present in the head, while no difference was observed in the trunk.

Our results demonstrated that different incubation temperatures during trout embryonic development did not change the stage of somatotroph cell appearance. Before hatching, IGF–2 and both IGF receptors, but not IGF–1 mRNA, were specifically up‐regulated by high temperatures and could be related to the enhancement of embryonic growth rate. J. Exp. Zool. 298A:134–142, 2003. © 2003 Wiley‐Liss, Inc.
On constructible graphs, locally Helly graphs, and convexity
Authors: Polat Norbert
Published: July 2003

A (finite or infinite) graph G is constructible if there exists a well‐ordering ≤ of its vertices such that for every vertex x which is not the smallest element, there is a vertex y < x which is adjacent to x and to every neighbor z of x with z < x. Particular constructible graphs are Helly graphs and connected bridged graphs. In this paper we study a new class of constructible graphs, the class of locally Helly graphs. A graph G is locally Helly if, for every pair (x,y) of vertices of G whose distance is d ≥ 2, there exists a vertex whose distance to x is d − 1 and which is adjacent to y and to all neighbors of y whose distance to x is at most d. Helly graphs are locally Helly, and the converse holds for finite graphs. Among different properties we prove that a locally Helly graph is strongly dismantable, hence cop‐win, if and only if it contains no isometric rays. We show that a locally Helly graph G is finitely Helly, that is, every finite family of pairwise non‐disjoint balls of G has a non‐empty intersection. We give a sufficient condition by forbidden subgraphs so that the three concepts of Helly graphs, of locally Helly graphs and of finitely Helly graphs are equivalent. Finally, generalizing different results, in particular those of Bandelt and Chepoi 1 about Helly graphs and bridged graphs, we prove that the Helly number h(G) of the geodesic convexity in a constructible graph G is equal to its clique number ω(G), provided that ω(G) is finite. © 2003 Wiley Periodicals, Inc. J Graph Theory 43: 280–298, 2003
Planar graphs producing no strongly almost trivial embedding
Authors: Huh Youngsik , Oh Seungsang
Published: July 2003

We present here infinitely many planar graphs which have no strongly almost trivial embeddings. Then we conclude that “strongly almost trivial” is more strict concept than “almost trivial.”. © 2003 Wiley Periodicals, Inc. J Graph Theory 43: 319–326, 2003
Construction of graphs with given circular flow numbers
Authors: Pan Zhishi , Zhu Xuding
Published: July 2003

Suppose r ≥ 2 is a real number. A proper r‐flow of a directed multi‐graph $\vec {G}=(V, E)$ is a mapping $f: E \to R$ such that (i) for every edge $e \in E$, $1 \leq |f(e)| \leq r-1$; (ii) for every vertex ${v} \in V$, $\sum _{e \in E^{+(v)}}f(e) - \sum _{e \in E^{-(v)}}f(e) = 0$. The circular flow number of a graph G is the least r for which an orientation of G admits a proper r‐flow. The well‐known 5‐flow conjecture is equivalent to the statement that every bridgeless graph has circular flow number at most 5. In this paper, we prove that for any rational number r between 2 and 5, there exists a graph G with circular flow number r. © 2003 Wiley Periodicals, Inc. J Graph Theory 43: 304–318, 2003
Hepatocellular carcinoma of diffuse type: MR imaging findings and clinical manifestations
Authors: Kanematsu Masayuki , Semelka Richard C. , Leonardou Polytimi , Mastropasqua Maria , Lee Joseph K.T.
Published: July 2003

Purpose:

To assess MR imaging findings and clinical manifestations of diffuse‐type hepatocellular carcinoma (HCC).

Materials and Methods:

We retrospectively reviewed our experience with diffuse HCC from November 1994 to October 2001. MR imaging findings and clinical features were assessed.

Results:

Twenty‐two consecutive patients with diffuse‐type HCC (19 men and three women, age range 16–80 years [mean, 52 years]) were identified in a review of liver MR studies. This represented 13% of all patients with HCC imaged during this time period. Diffuse HCC showed a permeative, infiltrative pattern with ill‐defined borders and no evidence of convex margination in all cases. At least 50% of the liver volume was involved with tumor. Diffuse‐type HCC showed hypointensity in 15 patients, mixed intensity in three, and isointensity in four on T1‐weighted images; heterogeneous hyperintensity in 16 patients; and homogeneous hyperintensity in six on T2‐weighted MR images. Diffuse‐type HCC showed patchy enhancement in 12 patients, miliary enhancement in nine, and minimal enhancement in one on postcontrast early‐phase images, and showed heterogeneous wash‐out in all patients on postcontrast late‐phase images. Proximal portal venous tumor thrombosis was seen in all patients. Serum α‐fetoprotein (AFP) value was elevated (>10 ng/mL) in 14 of 18 patients, and 13 showed a value greater than 500 ng/mL. The four patients who did not have elevated AFP had tumors which were indistinguishable from those in patients with elevated AFP; they also did not have a distinctive clinical history.

Conclusion:

Diffuse‐type HCC was typically seen as an extensive, heterogeneous permeative hepatic tumor, with portal venous tumor thrombosis on MR images in all cases. Early enhancement, observed as patchy in 12 and miliary in nine of 22 patients, was a distinctive imaging feature. Elevated serum AFP value was a common finding; however, 22% had normal values. J. Magn. Reson. Imaging 2003;18:189–195. © 2003 Wiley‐Liss, Inc.
Liver metastases from pancreatic adenocarcinoma: MR imaging characteristics
Authors: Danet Ioana‐Maria , Semelka Richard C. , Nagase Larissa L. , Woosely John T. , Leonardou Polytimi , Armao Diane
Published: July 2003

Purpose:

To describe the magnetic resonance imaging spectrum of appearances of liver metastases from pancreatic ductal adenocarcinoma.

Materials and Methods:

We retrospectively evaluated the MRI exams performed between July 1996 and August 2001 in all patients who had liver metastases from pancreatic adenocarcinoma and histopathologic diagnosis from either the primary pancreatic tumor, liver metastases, or both. Sixteen patients were included in the study. All MR studies were performed at 1.5 T with a standard protocol including T1‐ and T2‐weighted images and serial post‐gadolinium spoiled gradient echo (SGE) images. Location, size, number, signal characteristics on T1‐ and T2‐weighted images, and pattern of enhancement on serial gadolinium‐enhanced SGE images were assessed.

Results:

The diameter of metastases ranged from a few millimetres to 4 cm, and 12 patients (75%) had only lesions of 1.5 cm or less. Capsular‐based liver metastases were found in 13 patients (81%) and three patients had only capsular‐based lesions with a diameter under 1.5 cm. Hypervascular lesions were found in six patients (38%) and hypovascular lesions in 10 patients (62%). Perilesional enhancement was present in 10 patients (62%), with six patients (38%) having ring perilesional enhancement and eight patients (50%) having wedge‐shaped perilesional enhancement.

Conclusion:

On MR imaging, hepatic metastases from pancreatic adenocarcinoma show a range of enhancement patterns. Hypervascular metastases are not rare. Capsular based distribution, small diameter, and perilesional enhancement are common features. This retrospective study describes the MR imaging spectrum of appearances of liver metastases from pancreatic adenocarcinoma in patients with histopathologic confirmation of the diagnosis. J. Magn. Reson. Imaging 2003;18:181–188. © 2003 Wiley‐Liss, Inc.
Functional MRI of the rat lumbar spinal cord involving painful stimulation and the effect of peripheral joint mobilization
Authors: Malisza Krisztina L. , Stroman Patrick W. , Turner Allan , Gregorash Lori , Foniok Tadeusz , Wright Anthony
Published: July 2003

Purpose:

To examine neuronal activation in the spinal cord due to secondary hyperalgesia resulting from intrajoint capsaicin injection, and the effect of physiotherapy manipulation, using functional magnetic resonance imaging (fMRI), in α‐chloralose anesthetized rats.

Materials and Methods:

FMRI of the rat lumbar spinal cord was performed at 9.4 Tesla. Stimuli included injection of 25 μL of capsaicin (128 μg/mL in 7.5% dimethyl sulfoxide [DMSO]) into the right forepaw or 75 μL into the right ankle joint followed by a light touch stimulus, with and without physiotherapy manipulation.

Results:

Activation of pain areas of the spinal cord (dorsal horn) was found in all animals after injection of capsaicin into the plantar surface of the rat hindpaw and ankle joint. Overlay maps depicting activations and deactivations showed significant reproducibility between experiments. Greater overlay of activations were observed for intrajoint compared to intradermal capsaicin injection. The distribution of activations after stimulation of the hindpaw using a light touch stimulus was somewhat more varied; activation of the dorsal horn was evident, with greater overlap resulting when joint mobilization was not performed.

Conclusion:

Results suggest a trend toward decreased areas of activation in the spinal cord associated with pain, as a result of hyperalgesia, following physiotherapy joint mobilization. J. Magn. Reson. Imaging 2003;18:152–159. © 2003 Wiley‐Liss, Inc.
Improved detection of metastases on magnetic resonance images by digital tissue recognition: Validation using VX‐2 tumor in the rabbit
Authors: Wyman Bradley T. , Stork Chris L. , Smith Justin P. , Price Roger E. , Gavin Patrick R. , Tucker Russell L. , Wisner Erik R. , Mattoon John S. , Hazle John D.
Published: July 2003

Purpose:

To evaluate the ability of a prototype digital tissue recognition (DTR) system to improve the accuracy of detection of metastases on magnetic resonance (MR) images in the rabbit VX‐2 tumor model.

Materials and Methods:

Multiple MR imaging (MRI) sequences, including pre‐contrast and post‐contrast enhanced T1‐weighted, T2‐weighted, proton‐density, and fast short inversion time inversion recovery (FSTIR), were acquired for six rabbits implanted with VX‐2 adenocarcinoma. For each rabbit, DTR used the MR intensity characteristics of a known tumor site to highlight other areas suspicious for tumor. Three independent veterinary radiologists with extensive experience in animal MRI interpreted the images for tumor both without and with the results of DTR. The conventional and DTR‐assisted interpretations were compared to pathology.

Results:

Using DTR, the radiologists found an average of 13.2% more true positive sites with a 10.3% reduction in false positives compared to unassisted interpretation. The improvement for the radiologists was statistically significant (McNemar's test, P = 0.0004). The agreement between radiologists using DTR was consistently higher than for their conventional interpretations (kappa statistic).

Conclusion:

Compared with conventional interpretation of MR images, the use of DTR provided a statistically significant improvement in the accuracy of locating more and smaller sites of tumor. This improvement was achieved without the benefit of post‐contrast images. J. Magn. Reson. Imaging 2003;18:232–241. © 2003 Wiley‐Liss, Inc.
Characterization of interpolation effects in cine anatomic and phase‐velocity images
Authors: Wood John C.
Published: July 2003

Purpose:

To compare actual and predicted frequency response of reconstruction algorithms applied to anatomic and phase‐contrast velocity cine images.

Materials and Methods:

Anatomic and phase‐contrast velocity segmented cine gradient echo images were collected from a stationary, doped‐agarose phantom, using non‐phase‐contrast cine and phase‐contrast cine with one to three directional encodings, one to 16 views per segment, and nearest‐neighbor or linear interpolation. Temporal power spectra from object pixels were fit to linear transfer function models; nearest‐neighbor interpolation by a sinc function and linear interpolation by a sinc2 function.

Results:

Simple linear transfer function models predicted >98% of the observed power spectral variation. Finite word effects produced small systematic differences at high temporal frequency.

Conclusion:

Temporal power spectra of cine images collected from stationary objects completely characterizes low pass filtration effects of interpolation. J. Magn. Reson. Imaging 2003;18:266–271. © 2003 Wiley‐Liss, Inc.
Autosomal dominant polycystic kidney disease: MR imaging evaluation using current techniques
Authors: Mosetti Maria Antonietta , Leonardou Polytimi , Motohara Tomofumi , Kanematsu Masayuki , Armao Diane , Semelka Richard C.
Published: July 2003

Purpose:

To determine the MR imaging findings of autosomal dominant polycystic kidney disease using current imaging techniques.

Materials and Methods:

We reviewed our five‐year experience with MR imaging of autosomal dominant polycystic kidney disease (ADPKD) to determine the spectrum of appearance of kidney disease, the occurrence of cysts in other abdominal organs, the size and number of cysts in the kidneys and other organs, and the association with other benign or malignant disease. Thirty patients (17 men and 13 women, age range 30 to 88 years old) with ADPKD were included in this study. All patients were examined by MR imaging including T2‐weighted single‐shot echo‐train spin‐echo and pre‐ and post‐gadolinium chelate spoiled gradient‐echo imaging.

Results:

All kidneys were involved with multiple, varying sized cysts scattered throughout the parenchyma. Giant renal cysts (>8 cm) were associated with pain in the only two patients who possessed them. Hemorrhage in renal cysts was observed in all kidneys with a heterogeneous pattern of involvement on non‐contrast T1‐ and T2‐weighted images, reflecting hemorrhage of varying age. The mean kidney size for the right kidney was 17.4 cm in length, 10.3 cm in transverse, and 9.4 cm in antero‐posterior diameter (AP); and for the left kidney, 15.9 cm in the length, 9.3 cm in the transverse, and 9.3 cm in AP diameter. Other organs involved included the liver (22 patients), the pancreas (three patients), with two of the above‐mentioned patients having both liver and pancreas cysts, and the spleen (one patient) who had both liver and splenic cysts. Massive liver involvement with large cysts was associated with abdominal pain. Malignant disease was present in five patients, including two patients with renal cell carcinoma, one with bladder cancer, one with lung cancer, and one patient with anal adenocarcinoma. Comparison of pre‐ and post‐contrast T1‐weighted images was essential to detect renal cancer.

Conclusion:

All kidneys in patients with ADPKD had extensive, varying‐sized cysts and in all cases some cysts showed evidence of hemorrhage. The liver was the second most common organ to be involved with cystic disease, in 73% of patients. Large cysts in the kidneys and liver were associated with abdominal pain. J. Magn. Reson. Imaging 2003;18:210–215. © 2003 Wiley‐Liss, Inc.
A framework for a streamline‐based probabilistic index of connectivity (PICo) using a structural interpretation of MRI diffusion measurements
Authors: Parker Geoffrey J.M. , Haroon Hamied A. , Wheeler‐Kingshott Claudia A.M.
Published: July 2003

Purpose:

To establish a general methodology for quantifying streamline‐based diffusion fiber tracking methods in terms of probability of connection between points and/or regions.

Materials and Methods:

The commonly used streamline approach is adapted to exploit the uncertainty in the orientation of the principal direction of diffusion defined for each image voxel. Running the streamline process repeatedly using Monte Carlo methods to exploit this inherent uncertainty generates maps of connection probability. Uncertainty is defined by interpreting the shape of the diffusion orientation profile provided by the diffusion tensor in terms of the underlying microstructure.

Results:

Two candidates for describing the uncertainty in the diffusion tensor are proposed and maps of probability of connection to chosen start points or regions are generated in a number of major tracts.

Conclusion:

The methods presented provide a generic framework for utilizing streamline methods to generate probabilistic maps of connectivity. J. Magn. Reson. Imaging 2003;18:242–254. © 2003 Wiley‐Liss, Inc.
Knowledge creation and the web: factors indicating why some intranets succeed where others fail
Authors: Stenmark Dick
Published: July 2003

In today's highly dynamic business environment, organizational creativity is one of the most important sources of competitive advantage. Although the unpredictability of creativity makes it difficult to plan for, it may still be possible to facilitate knowledge creation given that we understand what affects it. In this paper, seven enabling factors of organizational creativity are identified and discussed. These factors are then compared to the specific characteristics of intranet technology in order to find out when and how this environment may stimulate creativity. The conclusion is that intranets are most likely to contribute by providing a variety of information in dynamic and unpredictable environments. However, standard management literature instead unanimously prescribes organizational convergence as the default strategy for the modern manager. Our analysis suggests that this control approach not only conflicts with some of the creativity‐enabling factors but also clashes with the fundamental principles underpinning the web. The organizational implication of the conclusion presented in this paper is that only in organizations where management has embraced an updated attitude towards information management, can the corporate intranet truly contribute to knowledge creation and creativity. Copyright © 2003 John Wiley & Sons, Ltd.
Learning cycles, organizational back talk, and the persistence of theories in use: lessons of information systems development in a university administration context
Authors: Heiskanen Ari , Assinen Pauli
Published: July 2003

Learning experiences from twenty‐seven administrative information‐system‐development projects in a large Finnish university are analysed over a time frame of eighteen years. A series of reporting development projects was chosen for more detailed inspection. Organizational learning was conceptualized to consist of cycles during which the organizational reactions towards development actions reveal the successfulness of each project. In a retrospective analysis the authors found three learning cycles out of the twelve‐year‐long reporting development process. The authors define their approach as reflective information systems practice and relate it to action learning and action science. Copyright © 2003 John Wiley & Sons, Ltd.
Building community knowledge systems: an empirical study of IT‐support for sharing best practices among managers
Authors: Bansler Jørgen P. , Havn Erling C.
Published: July 2003

The paper reports a field study of knowledge sharing in a large and complex organization. The objective of the study was to gain an in‐depth understanding of the implementation and use of a web‐based knowledge sharing system designed to facilitate the circulation of best practices among middle managers. We followed the system from its introduction in early 1997 until it was abandoned in the beginning of 2000. We focused on the way the system was introduced in the organization, how it changed, and how the intended group of users received (and eventually rejected) the system. Based on our interviews and observations we identify five reasons for the systems failure. We close the paper by some reflections on the use of the concept of ‘shared practice’ in the development of IT‐supported knowledge sharing systems. Copyright © 2003 John Wiley & Sons, Ltd.