bluuebunny/crossref_metadata_2025 huggingface dataset:
Potential Binding Sites for Relaxin in Pregnant Rabbits
Authors: FIELDS PHILLIP A. , FIELDS MICHAEL J.
Published: June 2005

Abstract: The purpose of this study was to identify tissues in the day 25 pregnant rabbit that bind relaxin. First, the clearance half‐life of relaxin from the rabbit (n= 6) was determined by injecting 10 g porcine relaxin via the marginal ear vein. One‐milliliter blood samples were collected via a cannula in the central ear artery. Samples were collected at 10‐ and 5‐min pre‐relaxin and at 1‐min intervals post‐relaxin injection, and the relaxin concentrations determined by radioimmunoassay. The clearance half‐life was 4 min. Next, pregnant rabbits were infused with [125I]‐relaxin. Control rabbits (n= 3) received 10 g radio‐inert relaxin via the marginal ear vein in order to saturate endogenous receptors. Ten minutes later, 10 ng [125I]‐relaxin was similarly injected. Treated rabbits (n= 3) received only [125I]‐relaxin. After allowing sufficient time for clearance (24 min), a 1‐mL blood sample was removed via the central ear vein. Rabbits were euthanized, tissues of maternal and fetal origin excised, and cpm/mg of tissue divided by cpm/mL of blood was determined. Differences in uptake of [125I]‐relaxin between control and treated animals, using the Student paired t test, were found for the uterus (P<.05), uterine cervix (P <.03), and mammary gland (P <.05). These data suggest potential rabbit tissues with the LGR‐7 receptor.
Porcine and Human Relaxin Bioactivity: Bioactivities of Porcine Relaxin and Human Relaxin Do Not Differ in Mice and Rats
Authors: ZHAO SHUANGPING , LEE HYUNG‐YUL , SHERWOOD O.D
Published: June 2005

Abstract: This study compares the bioactivity of porcine relaxin‐1 to that of recombinant human relaxin‐2 in mice and rats. The effects of the two hormone preparations on elongation of the mouse interpubic ligament and both the wet weight and the extensibility of the rat cervix were compared. No difference in bioactivity was detected between porcine relaxin‐1 and recombinant human relaxin‐2 in either rodent. Therefore, decisions concerning which of the two available forms of relaxin to employ for in vivo experimentation in mice and rats can be made without concerns about relative bioactivity.
Tissue‐Specific Effects of Relaxin on the Reproductive Tract of Neonatal Gilts
Authors: YAN WENBO , WILEY ANNE A. , BARTOL FRANK F. , BAGNELL CAROL A.
Published: June 2005

Abstract: In the pig, relaxin treatment for 2 d from birth (postnatal day 0, PND 0) was not uterotrophic, but it increased cervical size. To understand the mechanism underlying this tissue‐specific response, relaxin receptor (LGR7) expression in the neonatal uterus and cervix was investigated. At PND 2, quantitative RT‐PCR analysis showed that LGR7 levels were higher in the cervix than in the uterus. Interestingly, relaxin decreased cervical LGR7 expression when compared to that of the controls. Differential expression of LGR7 between uterine and cervical tissues may contribute to tissue‐specific relaxin responsiveness in the neonatal porcine reproductive tract.
The Relaxin Gene‐Knockout Mouse: A Model of Progressive Fibrosis
Authors: SAMUEL CHRISHAN S. , ZHAO CHONGXIN , BATHGATE ROSS A.D. , DU XIAO‐JUN , SUMMERS ROGER J. , AMENTO EDWARD P. , WALKER LESLEY L. , MCBURNIE MARY , ZHAO LING , TREGEAR GEOFFREY W.
Published: June 2005

Abstract: Relaxin is well known for its actions on collagen remodeling. To improve our understanding of the physiologic role(s) of relaxin, the relaxin gene‐knockout (RLX‐KO) mouse was established by our group and subsequently phenotyped. Pregnant RLX‐KO mice underwent inadequate development of the pubic symphysis as well as the mammary glands and nipples compared to wild‐type mice, thus preventing lactation. Later studies showed that these deficiencies were associated with increased collagen, primarily in the nipple and vagina. Analysis of male RLX‐KO mice also demonstrated inadequate reproductive tract development. The testis, epididymis, and prostate of RLX‐KO mice showed delayed tissue maturation and growth associated with increased collagen deposition. In nonreproductive tissues, an age‐related increase in interstitial collagen (fibrosis) was also detected in the lung, heart, and kidneys of RLX‐KO mice and was associated with organ dysfunction. From 6‐9 months of age and onwards, all organs of RLX‐KO mice, particularly male mice, underwent progressive increases in tissue weight and collagen content (all P <.05) compared with wild‐type animals. The increased fibrosis contributed to bronchiole epithelium thickening and alveolar congestion (lung), atrial hypertrophy and increased ventricular chamber stiffness (heart) in addition to glomerulosclerosis (kidney). Treatment of RLX‐KO mice with recombinant human relaxin in early and developed stages of fibrosis caused the reversal of collagen deposition in the lung, heart, and kidneys. Together, these findings suggest that relaxin is a naturally occurring inhibitor of collagen deposition during normal development, aging, and pregnancy and can be used to prevent the progression of fibrosis.
Relaxin Regulates Collagen Overproduction Associated with Experimental Progressive Renal Fibrosis
Authors: SAMUEL CHRISHAN S. , MOOKERJEE ISHANEE , MASTERSON ROSEMARY , TREGEAR GEOFFREY W. , HEWITSON TIM D.
Published: June 2005

Abstract: Progressive fibrosis due to excess extracellular matrix (primarily collagen) is the final common pathway in all forms of chronic renal disease, regardless of etiology, and leads to tissue dysfunction, when normal tissue is replaced by scar tissue. Emerging work from ourselves and others suggests that the naturally occurring hormone relaxin has the potential to limit renal collagen production and reorganization, while increasing its degradation. The outlined studies demonstrate relaxin's potential as an antifibrotic agent against experimental progressive renal disease.
Localization of LGR7 (Relaxin Receptor) mRNA and Protein in Rat Forebrain: Correlation with Relaxin Binding Site Distribution
Authors: BURAZIN TANYA C.D. , JOHNSON KELLI J. , MA SHERIE , BATHGATE ROSS A.D. , TREGEAR GEOFFREY W. , GUNDLACH ANDREW L.
Published: June 2005

Abstract: Discrete neuronal populations in brain express relaxin and relaxin‐3, and molecular studies have identified former‐orphan, G‐protein‐coupled receptors LGR7 and GPCR135 as their native receptors. To better understand the role of central relaxin systems, we began to assess the anatomic distribution of these receptors and ligands in brain. This study documents the widespread distribution of LGR7 mRNA and LGR7‐like immunoreactivity (LI) throughout adult rat forebrain areas shown to contain specific [33P]‐relaxin binding sites. High densities of LGR7 mRNA hybridization were detected in deep layers of neocortex, hypothalamic paraventricular and supraoptic nuclei and within hippocampal subiculum and CA3, the basolateral amygdala and subfornical organ. Low to moderate hybridization was detected in septum, midline thalamic nuclei, arcuate and supramammillary nuclei, and regions of the midbrain pons. Complementary expression of LGR7‐LI was observed in cortical pyramidal neurons, hypothalamic magnocellular neurons, and hippocampal pyramidal and interneurons. These findings provide further evidence for actions of relaxin as a modulator in somatosensory, autonomic, and neuroendocrine pathways.
New Insight into the Transcriptional Regulation of Vascular Endothelial Growth Factor Expression in the Endometrium by Estrogen and Relaxin
Authors: KOOS ROBERT D. , KAZI ARMINA A. , ROBERSON MARK S. , JONES JENNY M.
Published: June 2005

Abstract: Increased uterine capillary permeability, which can be induced by both estrogen and relaxin, is required for endometrial growth and implantation. This effect is mediated in both cases by estrogen receptors (ERs), via stimulation of vascular endothelial growth factor (VEGF) expression. The sites on the VEGF promoter through which induction occurs, however, are completely unclear. We have used the technique of chromatin immunoprecipitation in vivo to localize the site of ER action and identify other transcription factors that are involved. We have found that ERa associates with Sp1/Sp3 at a GC‐rich region of the promoter. More interesting, however, is the observation that estrogen also induces rapid, transient binding of hypoxia‐inducible factor 1 (HIF‐1), which mediates VEGF transcription in response to hypoxia, to the promoter. The estrogen‐induced HIF‐1 binding closely matches the estrogen‐induced pattern of VEGF expression in the uterus, suggesting that HIF‐1 is involved in that induction, and probably that of many other genes as well (HIF‐1 is now known to regulate the expression of more than 40 genes). It is likely that studies now under way will also link relaxin‐induced VEGF expression to HIF‐1. This is based on the similarities in the effects of the two hormones on VEGF expression and on their shared ability to activate the PI3K and MAPK pathways, both of which can activate HIF‐1.
Effects of Relaxin on Neonatal Porcine Uterine Growth and Development
Authors: BAGNELL CAROL A. , YAN WENBO , WILEY ANNE A. , BARTOL FRANK F.
Published: June 2005

Abstract: Relaxin (RLX), a key reproductive hormone in pigs, stimulates uterine growth in pregnant and prepubertal gilts and in neonates 2 weeks after birth. The neonatal uterotrophic response to RLX is developmentally regulated and estrogen receptor dependent because RLX fails to increase uterine weight in the absence of estrogen receptor (ER)‐α or when the ER is chemically inactivated. However, the role of RLX and insulin‐like peptide‐3 receptors, LGR7 and LGR8, respectively, in the neonatal uterotrophic response is unknown. Current studies focus on direct (LGR7/8‐mediated) and indirect (ER‐mediated) effects of RLX in the neonatal porcine uterus. Porcine LGR7 and LGR8 cDNAs were cloned and used as probes to identify uterine transcripts for LGR7 and LGR8, which increased from birth (postnatal day [PND] 0) to PND 14, a critical period for porcine uterine development. In situ hybridization showed that endometrial signals for both LGR7 and LGR8 are predominantly stromal during this period. Administration of RLX on PND 0, before onset of uterine ER expression, increased uterine luminal epithelial height (P <.05) but not uterine weight in the LGR7/8‐positive uterus on PND 2. However, RLX increased both uterine weight and luminal epithelial height by PND 14 (P <.05), after overt endometrial ER expression. Aberrant ER activation between PND 0 and 14 alters the uterine organizational program and affects the function of adult porcine uterine tissues. Present data suggest that crosstalk between LGR7/8 and ER may be involved in estrogen‐sensitive morphoregulatory events that are central to the development of an optimally functional adult uterus in the pig.
The Pregnancy Hormone Relaxin Binds to and Activates the Human Glucocorticoid Receptor
Authors: DSCHIETZIG THOMAS , BARTSCH CORNELIA , GREINWALD MICHAEL , BAUMANN GERT , STANGL KARL
Published: June 2005

Abstract: The insulin‐like peptide relaxin is a central hormone of pregnancy, but it also produces antifibrotic, myocardial, renal, central nervous, and vascular effects. Recently, two G‐protein‐coupled receptors, LGR7 and LGR8, were identified as relaxin receptors. Prompted by reports on the immunoregulatory effects of relaxin, we investigated possible interactions with the human glucocorticoid receptor (GR). Relaxin blunted the endotoxin‐induced production of inflammatory cytokines (interleukin 1 [IL‐1], IL‐6, and tumor necrosis factor‐ α) by human macrophages, an effect that was suppressed by the GR antagonist RU‐486. In three different cell lines, relaxin induced GR activation, nuclear translocation, and DNA binding as assessed in glucocorticoid response element (GRE)‐luciferase assays. Coimmunoprecipitation experiments revealed physical interaction of endogenous and exogenous relaxin with cytoplasmic and nuclear GR. Relaxin competed with GR agonists for GR binding both in vivo, in whole‐cell assays, and in vitro, in fluorescence polarization assays. In LGR7‐ and LGR8‐free cells, the relaxin‐mediated activation of GR was preserved. In conclusion, relaxin acts as a GR agonist, a pathway pivotal to relaxin's effects on cytokine secretion by human macrophages. These findings may deepen our understanding of relaxin's many physiologic actions as well as our insights into general principles of hormone signaling.
Relaxin Stimulates Multiple Signaling Pathways: Activation of cAMP, PI3K, and PKCζ in THP‐1 Cells
Authors: DESSAUER CARMEN W. , NGUYEN BAO T.
Published: June 2005

Abstract: Relaxin has been shown previously to stimulate cyclic AMP production and the activation of MAPK. We reported that phosphoinositide‐3 kinase (PI3K) activity is required for biphasic stimulation of cAMP by relaxin and that relaxin treatment increased PI3K activity in THP‐1 cells. A downstream target of PI3K is protein kinase C zeta (PKCζ). Relaxin stimulated translocation of PKCζ to the plasma membrane in THP‐1, MCF‐7, pregnant human myometrial (PHM1‐31), and mouse mesangial (MMC) cells. PKCζ translocation is PI3K dependent and independent of cAMP production. Pharmacological and antisense approaches, utilized to inhibit or knock down PKCζ, resulted in a 40% inhibition of relaxin‐stimulated cAMP production. The stimulation of PKCζ by relaxin therefore is downstream of PI3K leading to increased cAMP production. To determine the role of PI3K/PKCζ stimulation by relaxin on downstream‐mediated events, we examined the increase in vascular endothelial growth factor (VEGF) gene expression by relaxin. Treatment of THP‐1 or MMC cells with the PI3K inhibitor, LY294002, abolished the relaxin‐mediated stimulation of VEGF transcript levels. In summary, relaxin has pleiotropic signaling effects in THP‐1 cells activating ERK1/2, cAMP, PI3K, and PKCζ. We have described a novel bifurcated pathway by which relaxin stimulates Gs alpha and PI3K/PKCζ leading to increased cAMP production and increased VEGF gene expression. Some, but not all, of these pathways are detected in other cell lines which may cause the unique diversity of downstream responses from this interesting hormone.
Signaling Pathways of the LGR7 and LGR8 Receptors Determined by Reporter Genes
Authors: HALLS MICHELLE L. , BATHGATE ROSS A. , ROCHE PETER J. , SUMMERS ROGER J.
Published: June 2005

Abstract: Although much is known about the pleiotropic effects mediated by relaxin, the exact signaling pathways involved remain relatively elusive. This study examines LGR7 and LGR8 signaling using reporter gene technology. The greatest response was observed at the CRE reporter (indicates activation of cAMP‐PKA and p38/JNK pathways), although INSL3 treatment of LGR8 produced a lower response than H2 relaxin treatment of LGR7. AP1 (which indicates activation of JNK pathways) was stimulated to a lesser degree. Three other reporters produced no response. The reporter gene studies suggest that ligand stimulation of LGR7 and LGR8 involves cAMP‐PKA and p38/JNK signaling.
Myocardial Relaxin Counteracts Hypertrophy in Hypertensive Rats
Authors: DSCHIETZIG THOMAS , BARTSCH CORNELIA , KINKEL TILL , BAUMANN GERT , STANGL KARL
Published: June 2005

Abstract: Current findings in male relaxin knockout mice indicate antifibrotic and positive lusitropic actions of relaxin on the myocardium. We investigated in 12‐month‐old male spontaneously hypertensive rats (SHR) and age‐matched male Wistar‐Kyoto rats (WKY) whether RLX shows antihypertrophic actions as well. SHR showed left heart hypertrophy and a selective elevation of left atrial and ventricular relaxin peptide which inversely correlated with the degree of hypertrophy. In adult rat cardiomyocytes, relaxin blunted phenylephrine‐induced hypertrophy by inhibiting activated ERK‐1/2 kinases. In conclusion, endogenous myocardial relaxin, upregulated in left heart hypertrophy, exerts antihypertrophic effects by inhibition of activated ERK‐1/2 kinases.
Relaxin Does Not Influence the Growth of Human Cervical Adenocarcinoma (HeLa) Cells in Culture
Authors: RHO YOUNG SHIN , MIN GYESIK
Published: June 2005

Abstract: This study was performed to determine whether relaxin influences the growth of human adenocarcinoma (HeLa) cells of the cervix, which has been shown to contain relaxin‐binding sites and proliferate by relaxin. Cells were maintained in Dulbecco's modified Eagle's medium with 5% fetal calf serum. Highly purified porcine relaxin was added at concentrations of 10−11 to 10−5 M and incubated for 44, 69, 94, and 118 h. Cell proliferation/cytotoxicity and endogenous nitric oxide production were determined using a colorimetric MTS assay and Griess assay, respectively. The results indicate that whereas relaxin promotes the growth rate of MCF‐7 cells, which is in agreement with previous reports, at the doses and times of exposure used in this study relaxin does not significantly influence the number of viable HeLa cells. However, relaxin at nanomolar concentrations (10−9 to 10−8 M) promoted the growth of HeLa cells in the presence of both estrogen and progesterone to a small extent. In agreement with these results, relaxin did not affect nitric oxide production. We conclude that relaxin may have differential effects on the growth of two different cancer cell types, MCF‐7 and HeLa cells.
Detection, Localization, and Action of the INSL3 Receptor, LGR8, in Rat Kidney
Authors: FU PING , SHEN PEI‐JUAN , ZHAO CHONG‐XIN , SCOTT DANIEL J. , SAMUEL CHRISHAN S. , WADE JOHN D. , TREGEAR GEOFFREY W. , BATHGATE ROSS A.D. , GUNDLACH ANDREW L.
Published: June 2005

Abstract: Recent molecular and pharmacologic studies have identified LGR8, a member of the leucine‐rich repeat‐containing G‐protein‐coupled receptor family, as a cognate receptor for insulin‐like peptide‐3 (INSL3). LGR8 mRNA has been detected in various tissues, but the precise roles of these INSL3‐LGR8 systems are unknown. In this study we first investigated the presence and cellular localization of LGR8 mRNA in both adult and developing rat kidney and subsequently examined the possible role of INSL3‐LGR8 signaling in cultured mesangial cells. LGR8 mRNA was detected in the kidney by polymerase chain reaction and localized by in situ hybridization in mature glomerular mesangial cells within the renal cortex, with highest levels detected at embryonic day 18 and lowest levels in adult kidney. Synthetic INSL3 inhibited the proliferation of mesangial cells in primary culture, indicating the presence of functional LGR8 on these cells. These findings suggest that INSL3/LGR8 signaling may be involved in the genesis and/or developmental maturation of renal glomeruli and in the regulation of mesangial cell density in the adult kidney.
Acute Myeloid Leukemia Stem Cells
Authors: DICK JOHN E.
Published: June 2005

Abstract:A fundamental problem in cancer research is identification of the cells within a tumor that sustain the growth of the neoplastic clone. The concept that only a subpopulation of rare cancer stem cells (CSCs) is responsible for maintenance of the neoplasm emerged nearly 50 years ago; however, conclusive proof for the existence of a CSC was obtained only relatively recently. The evidence for the existence of CSCs was first derived from the study of human acute myeloid leukemia (AML), largely because of the availability of quantitative stem cell assays for the leukemic stem cell (LSC). These studies showed that only rare cells within the leukemic clone had the capacity to initiate AML growth after transplant into NOD/SCID mice, establishing the hierarchical organization of AML. Recent clonal‐tracking studies showed that the LSC compartment is composed of different classes of LSCs, which can be distinguished on the basis of self‐renewal potential. These findings have important implications for our understanding of the leukemogenic process as well as the design of more effective therapies to eliminate AML based on eradication of the LSCs. These studies are briefly reviewed here.
Thrombopoietin Regulates Differentiation of Rhesus Monkey Embryonic Stem Cells to Hematopoietic Cells
Authors: WANG ZHENG , SKOKOWA JULIA , PRAMONO ANDRI , BALLMAIER MATTHIAS , WELTE KARL
Published: June 2005

Abstract: Thrombopoietin (TPO) is the primary regulator of megakaryocyte and platelet production in vitro and in vivo. It supports also survival and proliferation of hematopoietic stem cells. The TPO receptor, c‐mpl, is a member of the protooncogene family. Our studies focused on the effect of TPO on proliferation and differentiation of rhesus monkey embryonic stem cells to hematopoietic cells. The rationale of the present investigations was the finding that patients with congenital amegakaryocytic thrombocytopenia (CAMT) reveal c‐mpl mutations leading to the development of pancytopenia, suggesting that c‐mpl is expressed in early hematopoiesis. Here we demonstrate that rhesus monkey embryonic stem (ES) cells are capable of differentiating into uncommitted progenitor cells, including hemangioblasts (hematopoietic and endothelial precursor cells). The combination of TPO and vascular endothelial growth factor (VEGF) significantly increases the number of hemangioblasts and promotes even differentiation to CD34+ hematopoietic progenitor cells (up to 8%). In addition, analysis of gene expression during hemangioblast development demonstrates that TPO is capable of increasing the mRNA expression of the VEGF receptor (VEGFR) and its own receptor (c‐mpl). The in vitro differentiation of rhesus monkey ES cells provides an opportunity to better understand the mechanism of TPO function in the early stage of hematopoietic development from ES cells to mature hematopoietic cells.
Genetic and Functional Characterization of Isolated Stromal Cell Lines from the Aorta‐Gonado‐Mesonephros Region
Authors: WEISEL KATJA C. , MOORE MALCOLM A. S.
Published: June 2005

Abstract: The hematopoietic system interacts with a supportive stromal environment allowing maintenance and differentiation of hematopoietic stem cells (HSCs). The aorta‐gonado‐mesonephros (AGM) region serves as a unique embryonic microenvironment, generating the first adult repopulating HSCs in the mouse embryo. To eludicate factors involved in hematopoietic support and induction of hematopoietic differentiation, we isolated more than 100 stromal cell clones derived from the AGM region of embryonic day (E) 10.5 mouse embryos for functional and genetic analysis. Selected isolated AGM stromal cell lines are highly efficient in supporting maintenance and expansion of mouse and human hematopoietic stem and progenitor cells. In addition, we can demonstrate for the first time that AGM stromal cell lines are also potent inducers of hematopoietic differentiation of murine embryonic stem cells. Stromal gene array analysis has identified genes that could play a role in hematopoietic support.
Distinct Gene Expression Pattern of Malignant Hematopoietic Stem and Progenitor Cells in Polycythemia Vera
Authors: STEIDL ULRICH , SCHROEDER THOMAS , STEIDL CHRISTIAN , KOBBE GUIDO , GRAEF THORSTEN , BORK SIMONE , PECHTEL SABRINA , KLISZEWSKI SLAWOMIR , KUENDGEN ANDREA , ROHR ULRICH P. , FENK ROLAND , SCHROEDER MICHAEL , HAASE DETLEF , HAAS RAINER , KRONENWETT RALF
Published: June 2005

Abstract: Polycythemia vera (PV) is a chronic myeloproliferative disorder with an expansion of multipotent hematopoietic progenitor cells. Although it is known that hematopoietic progenitors in PV are erythropoietin independent and hypersensitive to several cytokines, the molecular oncogenic mechanisms in PV are largely unknown. In this study, we examined gene expression profiles of CD34+ cells from bone marrow of patients with de novo PV and from healthy volunteers to identify molecular changes associated with the malignant growth of hematopoietic stem and progenitor cells in this myeloproliferative disorder. Using cDNA arrays, we found significant differences (P < .01) in the expression of 107 genes. Proapoptotic genes (CASP2, CASP3, DAPK1, ALG2) were expressed at lower levels in PV‐CD34+ cells, reflecting a lower apoptotic activity. Fibrosis‐stimulating growth factors (transforming growth factor β1, transforming growth factor β2, bone morphogenetic protein 2, and endothelial growth factor) were expressed at significantly higher levels in PV‐CD34+ cells. Furthermore, PV‐CD34+ cells overexpressed several receptors, protein kinases, and proteasome subunits, which might be targets for directed therapeutic approaches. It is interesting that three retinoid receptors were overexpressed in PV‐CD34+ cells—retinoic acid receptor β (RARβ), retinoid X receptor β (RXRβ), and cellular retinoic acid binding protein 2 (CRABP2). Using methylcellulose colony‐forming assays, we found that the formation of erythroid colonies derived from PV hematopoietic progenitors was inhibited by all‐trans‐retinoic acid (ATRA), a natural ligand of those receptors, in a dose‐dependent manner, showing a maximum inhibition of 89% at 10 μM; the growth of myelomonocytic colonies was not significantly affected. These data suggest that the use of ATRA could be of therapeutic benefit for patients with PV.
Stem Cell Gene Transfer: Insights into Integration and Hematopoiesis from Primate Genetic Marking Studies
Authors: DUNBAR CYNTHIA E.
Published: June 2005

Abstract: Genetic marking strategies in the nonhuman primate model have elucidated a number of principles with relevance to implementation of clinical stem cell therapies, including the lineage potential, number, and life span of hematopoietic stem and progenitor cells. The recent occurrence of leukemias likely related to insertional activation of a proto‐oncogene in two patients with X‐severe combined immunodeficiency (SCID) syndromes treated with CD34+ cells transduced with retroviral vectors expressing the corrective common γ cytokine receptor gene has refocused attention on the issue of retroviral integration. We have analyzed >1500 independent insertions from rhesus macaques transplanted with CD34+ cells transduced with either MLV or SIV vectors. Of these, 46 rhesus macaques followed long term have not had progression to leukemia, abnormal hematopoiesis, or clonal hematopoiesis. However, the pattern of both MLV and SIV integrants in cells of these animals was found to be highly nonrandom, with a propensity for insertions of both vectors within genes: for MLV particularly near the transcription start site, and for SIV particularly in gene‐dense regions.
Introduction of Combined CHOP Plus Rituximab Therapy Dramatically Improved Outcome of Diffuse Large B-Cell Lymphoma in British Columbia
Authors: Sehn Laurie H. , Donaldson Jane , Chhanabhai Mukesh , Fitzgerald Catherine , Gill Karamjit , Klasa Richard , MacPherson Nicol , O'Reilly Susan , Spinelli John J. , Sutherland Judy , Wilson Kenneth S. , Gascoyne Randy D. , Connors Joseph M.
Published: June 2005

Purpose

For more than two decades, cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) has been the standard therapy for diffuse large B-cell lymphoma (DLBCL). The addition of rituximab to CHOP has been shown to improve outcome in elderly patients with DLBCL. We conducted a population-based analysis to assess the impact of this combination therapy on adult patients with DLBCL in the province of British Columbia (BC).

Methods

We compared outcomes during a 3-year period; 18 months before (prerituximab) and 18 months after (postrituximab) institution of a policy recommending the combination of CHOP and rituximab for all patients with newly diagnosed advanced-stage (stage III or IV or stage I or II with “B” symptoms or bulky [> 10 cm] disease) DLBCL.

Results

A total of 292 patients were evaluated; 140 in the prerituximab group (median follow-up, 42 months) and 152 in the postrituximab group (median follow-up, 24 months). Both progression-free survival (risk ratio, 0.56; 95% CI, 0.39 to 0.81; P = .002) and overall survival (risk ratio, 0.40; 95% CI, 0.27 to 0.61, P < .0001) were significantly improved in the postrituximab group. After controlling for age and International Prognostic Index score, era of treatment remained a strong independent predictor of progression-free survival (risk ratio, 0.59; 95% CI, 0.41 to 0.85; P = .005) and overall survival (risk ratio, 0.43; 95% CI, 0.29 to 0.66; P < .001). The benefit of treatment in the postrituximab era was present regardless of age.

Conclusion

The addition of rituximab to CHOP chemotherapy has resulted in a dramatic improvement in outcome for DLBCL patients of all ages in the province of BC.
Combination Antibody Therapy With Epratuzumab and Rituximab in Relapsed or Refractory Non-Hodgkin's Lymphoma
Authors: Leonard John P. , Coleman Morton , Ketas Jamie , Ashe Michelle , Fiore Jennifer M. , Furman Richard R. , Niesvizky Ruben , Shore Tsiporah , Chadburn Amy , Horne Heather , Kovacs Jacqueline , Ding Cliff L. , Wegener William A. , Horak Ivan D. , Goldenberg David M.
Published: June 2005

Purpose

To explore the safety and therapeutic activity of combination anti–B-cell monoclonal antibody therapy in non-Hodgkin's lymphoma (NHL).

Patients and Methods

Twenty-three patients with recurrent B-cell lymphoma received anti-CD22 epratuzumab 360 mg/m2and anti-CD20 rituximab 375 mg/m2monoclonal antibodies weekly for four doses each. Sixteen patients had indolent histologies (15 with follicular lymphoma) and seven had aggressive NHL (all diffuse large B-cell lymphoma [DLBCL]). Indolent patients had received a median of one (range, one to six) prior treatment, with 31% refractory to their last therapy and 81% with high-risk Follicular Lymphoma International Prognostic Index scores. Patients with DLBCL had a median of three (range, one to eight) prior regimens (14% resistant to last treatment) and 71% had high intermediate–risk or high-risk International Prognostic Index scores. All patients were rituximab naïve.

Results

Treatment was well tolerated, with toxicities principally infusion-related and predominantly grade 1 or 2. Ten (67%) patients with follicular NHL achieved an objective response (OR), including nine of 15 (60%) with complete responses (CRs and unconfirmed CRs). Four of six assessable patients (67%) with DLBCL achieved an OR, including three (50%) CRs. Median time to progression for all indolent NHL patients was 17.8 months.

Conclusion

The full-dose combination of epratuzumab with rituximab was well tolerated and had significant clinical activity in NHL, suggesting that this combination should be tested in comparison with single-agent treatment.
ETB receptor agonist, IRL 1620, does not affect paclitaxel plasma pharmacokinetics in breast tumour bearing rats
Authors: Rai Aarati , Rajeshkumar N V , Shord Stacy , Gulati Anil
Published: June 2005

Endothelins are potent endogenous vasoactive substances. We have found that intravenous administration of endothelin (ET)B receptor agonist, IRL 1620 (N-suc-[Glu9, Ala11,15]ET-1 (8–21)) to tumour bearing rats increases blood perfusion and enhances delivery of chemotherapeutic agents to the tumour tissue. This study was conducted to determine whether IRL 1620, an (ET)B receptor selective agonist, alters pharmacokinetics of paclitaxel in breast tumour bearing rats. Breast tumours were induced in female Sprague-Dawley rats by N-methyl-n-nitrosourea (50 mg kg−1, i.p). Saline (0.3 mL kg−1, i.v.) or IRL 1620 (3 nmol kg−1, i.v.), was administered to the tumour bearing rats via the tail vein. Paclitaxel (3 mg kg−1, i.v.) was administered 15 min after saline or IRL 1620 injection. Serial plasma samples were collected up to 10 h after paclitaxel administration and analysed using an HPLC-UV assay. In a similar study [3H]-paclitaxel (40 μCi, i.v.) was administered after saline or IRL 1620 injection as described above and serial plasma samples were collected until 24 h. Data was fitted to a three-compartment model and pharmacokinetic parameters were generated using WinNonlin software. The AUC0-∞ (9.42 ± 3.18 μg h mL−1), clearance (0.69 ± 0.17 L h−1 kg−1), volume of distribution (10.31 ± 4.54 L kg−1) and half life (1.00 ± 0.32h) of [3H]-paclitaxel in tumour rats were similar in rats treated with IRL 1620 or vehicle. Tumour concentration of [3H]-paclitaxel was determined in rats treated with IRL 1620 or vehicle and there was a significant increase in tumour paclitaxel concentration (308.59 ± 24.42%) in rats treated with IRL 1620 compared with vehicle. It is concluded that IRL 1620, an (ET)B receptor agonist, does not alter paclitaxel pharmacokinetics and can selectively augment the delivery of paclitaxel to the tumour tissue.
Inhibitory effects of a fermented ginseng extract, BST204, on the expression of inducible nitric oxide synthase and nitric oxide production in lipopolysaccharide-activated murine macrophages
Authors: Seo Jin Young , Lee Jun Ho , Kim Nam Wook , Kim Yong Jun , Chang Sung Ho , Ko Na Young , Her Erk , Yoo Young Hyo , Kim Jie Wan , Lee Beob Yi , Lee Hoi Young , Kim Young Mi , Choi Wahn Soo
Published: June 2005

In this study, the effects of BST204, a fermented ginseng extract, on the expression of inducible nitric oxide synthase (iNOS) and nitric oxide (NO) production are looked into. Crude ginseng extract was incubated with ginsenoside-β-glucosidase to prepare BST204. BST204, unlike lipopolysaccharide (LPS) and crude ginseng extract, did not affect the level of iNOS protein and NO production in unstimulated RAW 264.7 cells. However, it suppressed the level of iNOS protein and NO production in LPS-stimulated RAW 264.7 cells but did not manifest the same effect on the iNOS mRNA level. An investigation of the activating phosphorylation of p70 S6 kinase and 4E-BP1, which are important for translation, was conducted to investigate the suppressive mechanism of iNOS protein. LPS increased the phosphorylation of p70 S6 kinase, but not 4E-BP1, in a time-dependent manner, and BST204 inhibited it in a dose-dependent manner. The expression of iNOS protein, however, was partially suppressed by rapamycin, an upstream inhibitor of p70 S6 kinase. Therefore, this paper suggests that the suppression of iNOS protein by BST204 was partially correlated with the inhibition of p70 S6 kinase activation.
On the transition densities for reflected diffusions
Authors: Linetsky Vadim
Published: June 2005

Diffusion models in economics, finance, queueing, mathematical biology, and electrical engineering often involve reflecting barriers. In this paper, we study the analytical representation of transition densities for reflected one-dimensional diffusions in terms of their associated Sturm-Liouville spectral expansions. In particular, we provide explicit analytical expressions for transition densities of Brownian motion with drift, the Ornstein-Uhlenbeck process, and affine (square-root) diffusion with one or two reflecting barriers. The results are easily implementable on a personal computer and should prove useful in applications.
Weighted sums of subexponential random variables and their maxima
Authors: Chen Yiqing , Ng Kai W. , Tang Qihe
Published: June 2005

Let {Xk, k=1,2,…} be a sequence of independent random variables with common subexponential distribution F, and let {wk, k=1,2,…} be a sequence of positive numbers. Under some mild summability conditions, we establish simple asymptotic estimates for the extreme tail probabilities of both the weighted sum ∑k=1nwkXk and the maximum of weighted sums max1≤m≤n∑k=1mwkXk, subject to the requirement that they should hold uniformly for n=1,2,…. Potentially, a direct application of the result is to risk analysis, where the ruin probability is to be evaluated for a company having gross loss Xk during the kth year, with a discount or inflation factor wk.
Portfolio optimization with unobservable Markov-modulated drift process
Authors: Rieder Ulrich , Bäuerle Nicole
Published: June 2005

We study portfolio optimization problems in which the drift rate of the stock is Markov modulated and the driving factors cannot be observed by the investor. Using results from filter theory, we reduce this problem to one with complete observation. In the cases of logarithmic and power utility, we solve the problem explicitly with the help of stochastic control methods. It turns out that the value function is a classical solution of the corresponding Hamilton-Jacobi-Bellman equation. As a special case, we investigate the so-called Bayesian case, i.e. where the drift rate is unknown but does not change over time. In this case, we prove a number of interesting properties of the optimal portfolio strategy. In particular, using the likelihood-ratio ordering, we can compare the optimal investment in the case of observable drift rate to that in the case of unobservable drift rate. Thus, we also obtain the sign of the drift risk.
Differentiation of some functionals of risk processes, and optimal reserve allocation
Authors: Loisel Stéphane
Published: June 2005

For general risk processes, we introduce and study the expected time-integrated negative part of the process on a fixed time interval. Differentiation theorems are stated and proved. They make it possible to derive the expected value of this risk measure, and to link it with the average total time below 0, studied by Dos Reis, and the probability of ruin. We carry out differentiation of other functionals of one-dimensional and multidimensional risk processes with respect to the initial reserve level. Applications to ruin theory, and to the determination of the optimal allocation of the global initial reserve that minimizes one of these risk measures, illustrate the variety of fields of application and the benefits deriving from an efficient and effective use of such tools.
Asymptotic behaviour of critical controlled branching processes with random control functions
Authors: González M. , Molina M. , del Puerto I.
Published: June 2005

In this paper, we investigate the asymptotic behaviour of controlled branching processes with random control functions. In a critical case, we establish sufficient conditions for both their almost-sure extinction and for their nonextinction with a positive probability. For some suitably chosen norming constants, we also determine different kinds of limiting behaviour for this class of processes.
Processor-sharing and random-service queues with semi-Markovian arrivals
Authors: Wu De-An , Takagi Hideaki
Published: June 2005

We consider single-server queues with exponentially distributed service times, in which the arrival process is governed by a semi-Markov process (SMP). Two service disciplines, processor sharing (PS) and random service (RS), are investigated. We note that the sojourn time distribution of a type-l customer who, upon his arrival, meets k customers already present in the SMP/M/1/PS queue is identical to the waiting time distribution of a type-l customer who, upon his arrival, meets k+1 customers already present in the SMP/M/1/RS queue. Two sets of system equations, one for the joint transform of the sojourn time and queue size distributions in the SMP/M/1/PS queue, and the other for the joint transform of the waiting time and queue size distributions in the SMP/M/1/RS queue, are derived. Using these equations, the mean sojourn time in the SMP/M/1/PS queue and the mean waiting time in the SMP/M/1/RS queue are obtained. We also consider a special case of the SMP in which the interarrival time distribution is determined only by the type of the customer who has most recently arrived. Numerical examples are also presented.
Efficient algorithms for transient analysis of stochastic fluid flow models
Authors: Ahn Soohan , Ramaswami V.
Published: June 2005

We derive several algorithms for the busy period distribution of the canonical Markovian fluid flow model. One of them is similar to the Latouche-Ramaswami algorithm for quasi-birth-death models and is shown to be quadratically convergent. These algorithms significantly increase the efficiency of the matrix-geometric procedures developed earlier by the authors for the transient and steady-state analyses of fluid flow models.
Long-Term Contracting with Markovian Consumers
Authors: Battaglini Marco
Published: June 2005

To study how a firm can capitalize on a long-term customer relationship, we characterize the optimal contract between a monopolist and a consumer whose preferences follow a Markov process. The optimal contract is nonstationary and has infinite memory, but is described by a simple state variable. Under general conditions, supply converges to the efficient level for any degree of persistence of the types and along any history, though convergence is history-dependent. In contrast, as with constant types, the optimal contract can be renegotiation-proof, even with highly persistent types. These properties provide insights into the optimal ownership structure of the production technology.
House Prices, Borrowing Constraints, and Monetary Policy in the Business Cycle
Authors: Iacoviello Matteo
Published: June 2005

I develop and estimate a monetary business cycle model with nominal loans and collateral constraints tied to housing values. Demand shocks move housing and nominal prices in the same direction, and are amplified and propagated over time. The financial accelerator is not uniform: nominal debt dampens supply shocks, stabilizing the economy under interest rate control. Structural estimation supports two key model features: collateral effects dramatically improve the response of aggregate demand to housing price shocks; and nominal debt improves the sluggish response of output to inflation surprises. Finally, policy evaluation considers the role of house prices and debt indexation in affecting monetary policy trade-offs.
Mortality Reductions, Educational Attainment, and Fertility Choice
Authors: Soares Rodrigo R
Published: June 2005

This paper develops a model where reductions in mortality are the main force behind economic development. The model generates a pattern of changes similar to the demographic transition, where gains in life expectancy at birth are followed by reductions in fertility and increases in the rate of human capital accumulation. The onset of the transition is characterized by a critical level of life expectancy at birth, which marks the movement of the economy from a Malthusian equilibrium to an equilibrium with investments in human capital and the possibility of long-run growth.
Tinzaparin in Outpatients with Pulmonary Embolism or Deep Vein Thrombosis
Authors: Dager William E , King Jeff H , Branch Jennifer M , Chow Stacey L , Ferrer Ruby E , Pak Sandy , Togioka Patti Y , White Richard H
Published: June 2005

BACKGROUND

The low-molecular-weight heparins (LMWHs) have been shown to be effective in the outpatient treatment of deep vein thrombosis (DVT). Data regarding outpatient use of any LMWH in pulmonary embolism (PE) or tinzaparin in DVT while transitioning therapy to a vitamin K antagonist are limited.

OBJECTIVE

To determine the safety and efficacy of tinzaparin in patients with either DVT or PE being transitioned to warfarin during LMWH therapy in the outpatient setting.

METHODS

All patients who were treated with at least one outpatient dose of tinzaparin for venous thromboembolism (VTE) were identified. Charts of all patients followed within the University of California Davis healthcare system were reviewed. The incidence of bleeding and recurrent thromboembolism over a minimum of the first 4 weeks to a maximum of 12 weeks after initiating anticoagulation was assessed.

RESULTS

A total of 178 patients with acute VTE were treated with tinzaparin, and outcomes could be determined in 140 cases. Forty-seven percent of these patients had objectively documented PE. Only one (0.7%) case of recurrent VTE was observed. Major bleeding was documented in 5 (3.6%) and minor bleeding in 8 (5.8%) patients. Two bleeding events, both major, occurred during tinzaparin therapy.

CONCLUSIONS

Outpatient use of tinzaparin during transition to warfarin therapy in the treatment of VTE, including PE, appears to be feasible in patients who are judged candidates for home therapy.
Effect of the Freezing Conditions and Microwave Thawing Power on the Stability of Cefuroxime in Dextrose 5% Infusion Polyolefin Bags at 4 °C
Authors: Hecq Jean-Daniel , Boitquin Laurence P , Vanbeckbergen Danielle F , Jamart Jacques , Galanti Laurence M
Published: June 2005

BACKGROUND

Intravenous cefuroxime sodium solution could be prepared in advance by a centralized hospital pharmacy service to improve safety and time management.

OBJECTIVE

To investigate the effect of freezing and microwave thawing on the solution stability of cefuroxime.

METHODS

Cefuroxime 1.5 g in 100 mL of dextrose 5% in polyolefin bags was frozen individually (group A) or in one package (group B) for 98 days at −20 °C. The solutions were then thawed using microwaves at 270 (light cycle) or 800 watts (hard cycle) and stored at 4 °C. The cefuroxime concentration was measured by HPLC. Visual inspection was performed and pH was measured at that time. Stability of the solution was defined as a concentration remaining superior to 90% of the initial concentration by regression analysis.

RESULTS

No color change or precipitation in the solutions was observed. In group A, stability was at least 23 and 21 days after light and hard cycle thawing, respectively. In group B, stability was at least 21 and 18 days, respectively, with the pH increasing without affecting chromatographic parameters.

CONCLUSIONS

The optimal conditions for advance preparation of a solution containing cefuroxime 1.5% in dextrose 5% may be freezing of individual containers followed by a light cycle of microwave thawing.
Elemental Analysis with a Plasma Emission Echelle Spectrometer Employing a Charge Injection Device (CID) Detector
Authors: Bilhorn R. B. , Denton M. B.
Published: June 2005

An atomic emission spectrometer which allows simultaneous high-precision digital recording of the ultraviolet spectrum has been developed. The instrument employs both a custom-built echelle spectrometer and a custom-built slow-scan charge injection device (CID) based detector system. The system is capable of measuring the wide dynamic range of signal intensities associated with plasma emission sources, and sensitivity is comparable to that of photomultiplier-tube-equipped instruments. Unprecedented speed and flexibility for elemental analysis are provided by the ability to display background-subtracted emission spectra and to have the computer assist in spectral line identification. The design and performance of the optical system, methodologies for CID detector utilization in analytical spectroscopy, and techniques for wavelength calibration are presented. Examples for qualitative analysis and for the qualitative comparison of similar samples demonstrate the sensitivity, flexibility, and speed of the system.
The Far-IR Spectra of UO2, α-U3O8, and γ-UO3 Using the Light Pipe Reflection Method
Authors: Yu Bao-Zhu , Hansen Wilford N. , Ward John
Published: June 2005

The spectra of UO2, α-U3O8, and γ-UO3 in the 700–20 cm−1 range were examined with an FT-IR spectrometer with the use of a Cassegrainian-type light pipe cell. Generally, the light pipe reflection spectra obtained show more detail than the transmission measurements. Some weak peaks of lattice mode vibrations have been found. The coincidence of several spectral features in α-U3O8 and UO2 provides evidence that their structures are correlative. The spectra of γ-UO3 in this region are the first reported.
FT-Raman Microscopy: Discussion and Preliminary Results
Authors: Messerschmidt Robert G. , Chase D. Bruce
Published: June 2005

This paper reports on the first spectra obtained using a microscope apparatus to perform FT-Raman spectroscopy. It is considered desirable to use a standard FT-IR microscope for these measurements, since this approach may lead to the attainment of both FT-IR and FT-Raman microscope data from a single instrument. The relative performance of the microscope apparatus compared to that of a previously designed macro-apparatus is studied. The described micro-apparatus is then used to measure the FT-Raman spectrum of a single crystal of bis-methyl-styry I benzene and of a single fiber of Kevlar®. The results indicate an acceptable sensitivity, for these small samples.