bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sigma 32-Dependent Promoter Activity In Vivo: Sequence Determinants of the
groE
Promoter
Authors: Wang Yang , deHaseth Pieter L. 
Published: September 2003

ABSTRACT

The
Escherichia coli
transcription factor sigma 32 binds to core RNA polymerase to form the holoenzyme responsible for transcription initiation at heat shock promoters, utilized upon exposure of the cell to higher temperatures. We have developed two ways to assay sigma 32-dependent RNA synthesis in
E. coli
. The plasmid-borne reporter gene for both is
lacZ
(β-galactosidase), driven by the
groE
promoter. In one application, the cells are exposed to a temperature of 42°C in order to induce accumulation of endogenous sigma 32. The other involves isopropylthiogalactopyranoside (IPTG)-induced synthesis of sigma 32 at 30°C from a gene contained on a second plasmid. The latter employs DnaK
−
cells, which additionally contained a second mutation, inactivating the endogenous sigma 32 gene (Bukau and Walker, EMBO J. 9:4027-4036, 1990). These assays were used to delineate the sequences CTTGA (−37 to −33) and GNCCCCATNT (−18 to −9) as important for sigma 32 promoter activity. At each of the specified base pairs, substitutions were found which reduced promoter activity by greater than 75%. Activity was also dependent upon the number of base pairs separating the two regions.
Regulation of
fur
Expression by RpoS and Fur in
Vibrio vulnificus
Authors: Lee Hyun-Jung , Park Kyung-Je , Lee Ah Young , Park Sung Goo , Park Byoung Chul , Lee Kyu-Ho , Park Soon-Jung 
Published: September 2003

ABSTRACT

In a proteomic analysis of
rpoS
-deficient
Vibrio vulnificus
versus the wild type, one of the down-regulated proteins in the
rpoS
mutant strain was identified as a Fur protein, a ferric uptake regulator. The expression of a
fur
::
luxAB
fusion was significantly influenced by sigma factor S, the
rpoS
gene product, and positively regulated by Fur under iron-limited conditions.
Global Regulation of the
Salmonella enterica
Serovar Typhimurium Major Porin, OmpD
Authors: Santiviago Carlos A. , Toro Cecilia S. , Hidalgo Alejandro A. , Youderian Philip , Mora Guido C. 
Published: September 2003

ABSTRACT

The OmpD porin is the most abundant outer membrane protein in
Salmonella enterica
serovar Typhimurium and represents about 1% of total cell protein. Unlike the case with the less abundant OmpC and OmpF porins, the stoichiometry of OmpD in the outer membrane does not change in response to changes in osmolarity. The abundance of OmpD increases in response to anaerobiosis and decreases in response to low pH, conditions encountered by serovar Typhimurium during the infection of its murine host. By constructing an operon fusion of the
lacZY
genes with the
ompD
promoter, we show that the abundance of OmpD in the outer membrane is regulated primarily at the level of transcription and is subject to catabolite repression. In response to anaerobiosis, the abundance of OmpD in the outer membrane also appears to be controlled posttranscriptionally by a function dependent on Fnr.
Reduced stem cell mobilization in mice receiving antibiotic modulation of the intestinal flora: involvement of endotoxins as cofactors in mobilization
Authors: Velders Gerjo A. , van Os Ronald , Hagoort Henny , Verzaal Perry , Guiot Henri F. L. , Lindley Ivan J. D. , Willemze Roel , Opdenakker Ghislain , Fibbe Willem E. 
Published: September 2003

AbstractSince endotoxins are potent inducers of stem cell mobilization, we hypothesized that their presence in the gut may play a role in cytokine-induced mobilization. To address this possibility we added ciprofloxacin and polymyxin B to the drinking water of Balb/c mice mobilized with either interleukin-8 (IL-8), granulocyte colony-stimulating factor (G-CSF), or flt3 ligand (FL). The yield of colony-forming units (CFUs) was significantly reduced in all mice treated with these antibiotics when compared with controls (IL-8: 192 ± 61 vs 290 ± 64, P &lt; .05; G-CSF: 1925 ± 1216 vs 3371 ± 1214, P &lt; .05; FL: 562 ± 213 vs 1068 ± 528, P &lt; .05). Treatment with ciprofloxacin eliminated only aerobic Gramnegative bacteria from the feces without effect on mobilization. Polymyxin B treatment did not result in decontamination but significantly reduced the number of mobilized hematopoietic progenitor cells (HPCs) most likely due to the endotoxin binding capacity of polymyxin B. More than 90% of the gastrointestinal flora consists of anaerobic bacteria. Elimination of the anaerobic flora by metronidazol led to a significantly reduced number of mobilized HPCs when compared with controls (IL-8: 55 ± 66 vs 538 ± 216, P &lt; .05). Germ-free OF1 mice showed a significantly reduced mobilization compared with their wild-type controls (IL-8 controls: 378 ± 182, IL-8 germ free: 157 ± 53, P &lt; .05). Finally, we performed reconstitution experiments adding Escherichia coli–derived endotoxins to the drinking water of decontaminated mice. This resulted in partial restoration of the IL-8–induced mobilization (67 ± 28 vs 190 ± 98.1, P &lt;.01). Our results indicate that endotoxins serve as cofactors in cytokine-induced mobilization. Modification of the endotoxin content by antibiotic treatment may affect the yield of cytokine-induced mobilization.
Ultrastructural study shows morphologic features of apoptosis and para-apoptosis in megakaryocytes from patients with idiopathic thrombocytopenic purpura
Authors: Houwerzijl Ewout J. , Blom Nel R. , van der Want Johannes J. L. , Esselink Mariet T. , Koornstra Jan J. , Smit Jan W. , Louwes Henk , Vellenga Edo , de Wolf Joost Th. M. 
Published: September 2003

Abstract
To investigate whether altered megakaryocyte morphology contributes to reduced platelet production in idiopathic thrombocytopenic purpura (ITP), ultrastructural analysis of megakaryocytes was performed in 11 ITP patients. Ultrastructural abnormalities compatible with (para-)apoptosis were present in 78% ± 14% of ITP megakaryocytes, which could be reversed by in vivo treatment with prednisone and intravenous immunoglobulin. Immunohistochemistry of bone marrow biopsies of ITP patients with extensive apoptosis showed an increased number of megakaryocytes with activated caspase-3 compared with normal (28% ± 4% versus 0%). No difference, however, was observed in the number of bone marrow megakaryocyte colony-forming units (ITP, 118 ± 93/105 bone marrow cells; versus controls, 128 ± 101/105 bone marrow cells; P = .7). To demonstrate that circulating antibodies might affect megakaryocytes, suspension cultures of CD34+ cells were performed with ITP or normal plasma. Morphology compatible with (para-)apoptosis could be induced in cultured megakaryocytes with ITP plasma (2 of 10 samples positive for antiplatelet autoantibodies). Finally, the plasma glycocalicin index, a parameter of platelet and megakaryocyte destruction, was increased in ITP (57 ± 70 versus 0.7 ± 0.2; P = .009) and correlated with the proportion of megakaryocytes showing (para-) apoptotic ultrastructure (P = .02; r = 0.7). In conclusion, most ITP megakaryocytes show ultrastructural features of (para-) apoptosis, probably due to action of factors present in ITP plasma.
Interleukin-6–dependent gene expression profiles in multiple myeloma INA-6 cells reveal a Bcl-2 family–independent survival pathway closely associated with Stat3 activation
Authors: Brocke-Heidrich Katja , Kretzschmar Antje K. , Pfeifer Gabriele , Henze Christian , Löffler Dennis , Koczan Dirk , Thiesen Hans-Jürgen , Burger Renate , Gramatzki Martin , Horn Friedemann 
Published: September 2003

AbstractInterleukin 6 (IL-6) is a growth and survival factor for multiple myeloma cells. As we report here, the IL-6–dependent human myeloma cell line INA-6 responds with a remarkably rapid and complete apoptosis to cytokine withdrawal. Among the antiapoptotic members of the B-cell lymphoma-2 (Bcl-2) family of apoptosis regulators, only myeloid cell factor-1 (Mcl-1) was slightly induced by IL-6. Overexpression studies demonstrated, however, that IL-6 does not exert its survival effect primarily through this pathway. The IL-6 signal transduction pathways required for survival and the target genes controlled by them were analyzed by using mutated receptor chimeras. The activation of signal transducer and activator of transcription 3 (Stat3) turned out to be obligatory for the survival of INA-6 cells. The same held true for survival and growth of XG-1 myeloma cells. Gene expression profiling of INA-6 cells by using oligonucleotide microarrays revealed many novel IL-6 target genes, among them several genes coding for transcriptional regulators involved in B-lymphocyte differentiation as well as for growth factors and receptors potentially implicated in autocrine or paracrine growth control. Regulation of most IL-6 target genes required the activation of Stat3, underscoring its central role for IL-6 signal transduction. Taken together, our data provide evidence for the existence of an as yet unknown Stat3-dependent survival pathway in myeloma cells.
Hepatic injury after nonmyeloablative conditioning followed by allogeneic hematopoietic cell transplantation: a study of 193 patients
Authors: Hogan William J. , Maris Michael , Storer Barry , Sandmaier Brenda M. , Maloney David G. , Schoch H. Gary , Woolfrey Ann E. , Shulman Howard M. , Storb Rainer , McDonald George B. 
Published: September 2003

Abstract
Liver injury is a frequent, serious complication of allogeneic hematopoietic cell transplantation (HCT) following myeloablative preparative regimens. We sought to determine the frequency and severity of hepatic injury after nonmyeloablative conditioning and its relationship to outcomes. One hundred ninety-three consecutive patients who received 2 Gy total body irradiation with or without fludarabine were evaluated for end points related to liver injury. Patients with diseases treatable by HCT who were ineligible for conventional myeloablative allogeneic HCT because of advanced age and/or comorbid conditions were included. Fifty-one patients (26%) developed hyperbilirubinemia of 68.4 μM (4 mg/dL) or greater, most commonly resulting from cholestasis due to graft-versus-host disease (GVHD) or sepsis. Pretransplantation factors associated with liver dysfunction were a diagnosis of aggressive malignancy (hazard ratio [HR] 1.9; P = .04) and the inclusion of fludarabine in the conditioning regimen (HR 1.8; P = .07). Overall survival at 1 year was superior for patients who had maximal serum bilirubin levels in the normal (78%) or minimally elevated (22.23-66.69 μM [1.3-3.9 mg/dL]) ranges (69%) compared with those in the 68.4 to 117.99 μM (4-6.9 mg/dL; 20%), 119.7 to 169.29 μM (7.0-9.9 mg/dL; 17%), and 171.0 μM (10 mg/dL; 19%) or greater groups. In summary, significant jaundice occurred in 26% of patients and was predominantly due to cholestasis resulting from GVHD and/or sepsis. Aggressive malignancies (mainly advanced disease) and later development of jaundice after transplantation predicted inferior survival.
Prognostic significance of bcl-xL gene expression and apoptotic cell counts in follicular lymphoma
Authors: Zhao Wei-Li , Daneshpouy Marjan Ertault , Mounier Nicolas , Brière Josette , Leboeuf Christophe , Plassa Louis-François , Turpin Elisabeth , Cayuela Jean-Michel , Ameisen Jean-Claude , Gisselbrecht Christian , Janin Anne 
Published: September 2003

Abstract
bcl-xL, a member of the Bcl-2 family, exerts an antiapoptotic effect on lymphocytes. To assess its clinical significance in patients with follicular lymphoma, realtime quantitative reverse transcription–polymerase chain reaction (RT-PCR) analysis of bcl-xL gene expression was investigated in whole lymph node sections and laser-microdissected lymphoma cells of 27 patients. Compared with 10 patients with reactive follicular hyperplasia, the bcl-xL gene was overexpressed in patients with follicular lymphoma at a higher level in microdissected lymphoma cells. The bcl-xL gene level correlated with the number of apoptotic lymphoma cells labeled by terminal deoxytransferase-catalyzed DNA nick-end labeling (TUNEL) assays (r = -0.7736). Clinically, a high bcl-xL level was significantly associated with multiple sites of extranodal involvement (P = .0020), elevated lactate dehydrogenase level (P = .0478), and an International Prognostic Index indicating high risk (P = .0235). Moreover, bcl-xL gene overexpression was linked to short overall survival times (P = .0129). The value of bcl-xL gene expression as a prognostic marker in follicular lymphoma should thus be considered.
Adult human hematopoietic cells provide functional hemangioblast activity
Authors: Cogle Christopher R. , Wainman David A. , Jorgensen Marda L. , Guthrie Steven M. , Mames Robert N. , Scott Edward W. 
Published: September 2003

AbstractThe murine adult hematopoietic stem cell is able to function as a hemangioblast, contributing both to blood reconstitution and to blood vessel repair in response to ischemic injury. We developed a novel mouse xenotransplantation model of retinal neovascularization to test human hematopoietic cell plasticity. Immunocompromised nonobese diabetic (NOD)/scid mice underwent myeloablative conditioning and transplantation with human CD34+ umbilical cord blood. After multilineage reconstitution was established, retinal ischemia was induced to promote neovascularization. Our results demonstrate human retinal neovascularization, thus revealing the functional hemangioblast activity of human hematopoietic cells.
Effects of prednisone and genetic polymorphisms on etoposide disposition in children with acute lymphoblastic leukemia
Authors: Kishi Shinji , Yang Wenjian , Boureau Benoit , Morand Stanislas , Das Soma , Chen Peixian , Cook Edwin H. , Rosner Gary L. , Schuetz Erin , Pui Ching-Hon , Relling Mary V. 
Published: September 2003

AbstractEtoposide is a substrate for P-glycoprotein, CYP3A4, CYP3A5, and UGT1A1. Glucocorticoids modulate CYP3A and P-glycoprotein in preclinical models, but their effect on clinical etoposide disposition is unknown. We studied the pharmacokinetics of etoposide and its catechol metabolite in children with acute lymphoblastic leukemia, along with polymorphisms in CYP3A4, CYP3A5, MDR1, GSTP1, UGT1A1, and VDR. Plasma pharmacokinetics were assessed at day 29, after 1 month of prednisone (n = 102), and at week 54, without prednisone (n = 44). On day 29, etoposide clearance was higher (47.4 versus 29.2 mL/min/m2, P &lt; .0001) than at week 54. The day 29 etoposide or catechol area under the curve (AUC) was correlated with neutropenia (P = .027 and P = .0008, respectively). The relationship between genotype and etoposide disposition differed by race and by prednisone use. The MDR1 exon 26 CC genotype predicted higher day 29 etoposide clearance (P = .002) for all patients, and the CYP3A5 AA and GSTP1 AA genotypes predicted lower clearance in blacks (P = .02 and .03, respectively). The UGT1A1 6/6, VDR intron 8 GG, and VDR Fok 1 CC genotypes predicted higher week 54 clearance in blacks (P = .039, .036, and .052, respectively). The UGT1A1 6/6 genotype predicted lower catechol AUC. Prednisone strongly induces etoposide clearance, genetic polymorphisms may predict the constitutive and induced clearance of etoposide, and the relationship between genotype and phenotype differs by race.
TRAIL regulates normal erythroid maturation through an ERK-dependent pathway
Authors: Secchiero Paola , Melloni Elisabetta , Heikinheimo Markku , Mannisto Susanna , Di Pietro Roberta , Iacone Antonio , Zauli Giorgio 
Published: September 2003

Abstract
In order to investigate the biologic activity of tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) on human erythropoiesis, glycophorin A (GPA)+ erythroid cells were generated in serum-free liquid phase from human cord blood (CB) CD34+ progenitor cells. The surface expression of TRAIL-R1 was weakly detectable in the early-intermediate phase of erythroid differentiation (days 4-6; dim-intermediate GPA expression), whereas a clear-cut expression of TRAIL-R2 was observed through the entire course of erythroid differentiation (up to days 12-14; bright GPA expression). On the other hand, surface TRAIL-R3 and -R4 were not detected at any culture time. Besides inducing a rapid but small increase of apoptotic cell death, which was abrogated by the pan-caspase inhibitor z-VAD-fmk, the addition of recombinant TRAIL at day 6 of culture inhibited the generation of morphologically mature erythroblasts. Among the intracellular pathways investigated, TRAIL significantly stimulated the extracellular signal-regulated kinase 1/2 (ERK1/2) but not the p38/mitogen-activated protein kinase (MAPK) or the c-Jun NH2-terminal kinase (JNK) pathway. Consistently with a key role of ERK1/2 in mediating the negative effects of TRAIL on erythroid maturation, PD98059, a pharmacologic inhibitor of the ERK pathway, but not z-VAD-fmk or SB203580, a pharmacologic inhibitor of p38/MAPK, reverted the antidifferentiative effect of TRAIL on CB-derived erythroblasts.
Human CD8+ T cells recognize epitopes of the 28-kDa hemolysin and the 38-kDa antigen ofMycobacterium tuberculosis
Authors: Shams Homayoun , Barnes Peter F , Weis Stephen E , Klucar Peter , Wizel Benjamin 
Published: September 2003

AbstractMycobacterium tuberculosis antigens that are recognized by human CD8+ T cells are potentially important vaccine target molecules. We used a motif-based strategy to screen selected proteins of M. tuberculosis for peptides predicted to bind to human leukocyte antigen (HLA)-A*0201. We identified two 10 amino acid peptides that elicited cytolytic T lymphocyte activity and interferon-γ production by CD8+ T cells from HLA-A*0201+ healthy tuberculin reactors. These peptides were derived from the 38-kDa antigen and the 28-kDa hemolysin, the latter being a novel target for CD8+ T cells. We speculate that hemolysins may alter the phagosomal membrane surrounding intracellular M. tuberculosis, allowing themselves and other antigens to gain access to the major histocompatibility complex class I processing pathway.
A novel population of Gr-1+-activated macrophages induced during acute toxoplasmosis
Authors: Mordue Dana G , Sibley L David 
Published: September 2003

AbstractMacrophages are potent mediators of parasite control following in vitro activation, yet the subsets of mononuclear cells that contribute to resistance in vivo remain poorly defined. To identify effector cells that contribute to the control of Toxoplasma gondii during the initial stages of disseminated infection, we developed a low-dose intraperitoneal challenge model. A population of unusual macrophage-like cells was recruited to the peritoneal cavity during the first 4 days postinfection. Surprisingly, these cells expressed the granulocyte marker Gr-1 and the macrophage marker CD68. They also expressed high levels of major histocompatibility complex class II and low levels of F4/80 and CD11b and were negative for the immature myeloid cell marker CD31, the dendritic cell marker CD11c, and the B cell marker B220. Gr-1+ macrophages produced interleukin-12 p40, generated reactive nitrogen intermediates during acute infection, and inhibited virulent type I and nonvirulent type II strains of the parasite in vitro. Gr-1+ macrophages were the primary cell type recruited in response to nonvirulent type II strain parasites, and large numbers of neutrophils (Gr-1+/CD68−) were also recruited to the peritoneum in response to virulent type I strain parasites. Our findings suggest that activated CD68+/Gr-1+ macrophages contribute to parasite control during infection by directly inhibiting parasite replication and through production of T helper cell type I cytokines.
Increased neutrophil influx but no impairment of protective immunity to tuberculosis in mice lacking the CD44 molecule
Authors: Kipnis Andre , Basaraba Randall J , Turner Joanne , Orme Ian M 
Published: September 2003

AbstractUp-regulation of expression of the cell-surface marker CD44 is a major characteristic of T lymphocytes responding in the lungs of mice infected with Mycobacterium tuberculosis. These lymphocytes express an activated/memory phenotype as seen by their high expression of the CD44 molecule and low expression of CD62L and CD45RB cell-surface molecules. Based on increasing evidence that the CD44 molecule participates in several aspects of the inflammatory response, we evaluated its role in the response to infection with M. tuberculosis using gene-disrupted mice. In this report, we show that CD44 expression is not necessary for the proper trafficking of protective cells to the lungs of mice infected with M. tuberculosis or the direct expression of protective immunity leading to control and containment of the bacterial load in this organ. However, although there were no differences in the bacterial load or migration of activated T lymphocytes to the inflamed lung, the absence of the CD44 molecule resulted in a substantially increased accumulation of neutrophils in the lung. These data indicate that loss of CD44 expression does not alter expression of T helper cell type 1 immunity to tuberculosis in the lungs but has major effects on the overall cellular composition of the immunopathological response.
Collectins and their role in lung immunity
Authors: Hickling T P , Clark H , Malhotra R , Sim R B 
Published: September 2003

AbstractThe collectins are a small family of secreted glycoproteins that contain C-type lectin domains and collagenous regions. They have an important function in innate immunity, recognizing and binding to microorganisms via sugar arrays on the microbial surface. Their function is to enhance adhesion and phaocytosis of microorganisms by agglutination and opsonization. In the lung, two members of the collectin family, surfactant proteins A and D, are major protein constituents of surfactant. Another collectin, mannan-binding lectin, is also present in the upper airways and buccal cavity and may protect against respiratory infections. Recent work has shown that collectins have roles in resistance to allergy and in the control of apoptosis and clearance of apoptotic macrophage in the lung.
Host defense function of the airway epithelium in health and disease: clinical background
Authors: Message Simon D , Johnston Sebastian L 
Published: September 2003

AbstractRespiratory infection is extremely common and a major cause of morbidity and mortality worldwide. The airway epithelium has an important role in host defense against infection and this is illustrated in this review by considering infection by respiratory viruses. In patients with asthma or chronic obstructive pulmonary disease, respiratory viruses are a common trigger of exacerbations. Rhinoviruses (RV) are the most common virus type detected. Knowledge of the immunopathogenesis of such RV-induced exacerbations remains limited, but information is available from in vitro and from in vivo studies, especially of experimental infection in human volunteers. RV infects and replicates within epithelial cells (EC) of the lower respiratory tract. EC are an important component of the innate-immune response to RV infection. The interaction between virus and the intracellular signaling pathways of the host cell results in activation of potentially antiviral mechanisms, including type 1 interferons and nitric oxide, and in the producton of cytokines and chemokines [interleukin (IL)-1β, IL-6, IL-8, IL-11, IL-16, tumor necrosis factor α, granulocyte macrophage-colony stimulating factor, growth-regulated oncogene-α, epithelial neutrophil-activating protein-78, regulated on activation, normal T expressed and secreted, eotaxin 1/2, macrophage-inflammatory protein-1α], which influence the subsequent induced innate- and specific-immune response. Although this is beneficial in facilitating clearance of virus from the respiratory tract, the generation of proinflammatory mediators and the recruitment of inflammatory cells result in a degree of immunopathology and may amplify pre-existing airway inflammation. Further research will be necessary to determine whether modification of EC responses to respiratory virus infection will be of therapeutic benefit.