Clonal and pathotypic analysis of archetypal Escherichia coli cystitis isolate NU14.

Escherichia coli NU14, a cystitis isolate used to study the pathogenesis of cystitis and to develop a FimH (type 1 fimbrial adhesin) vaccine, was assessed for extended virulence genotype, phylogenetic background, and FimH sequence and binding phenotype(s). NU14 exhibited the same virulence genotype and was derived from the same (meningitis- and cystitis-associated) subclone of E. coli O18:K1:H7 as the archetypal neonatal bacterial meningitis (NBM) isolate RS218.

Human MHC class III and IV genes and disease associations.

The major histocompatibility complex (MHC) was initially defined as the genetic locus encoding the Class I and Class II highly polymorphic cell surface antigens that are now known to present antigen to matched sets of T cell receptors. Genes for several diverse complement components, specifically Bf, C2, and C4 were found between the Class I and II genes, in a region later dubbed Class III. More recently, several genes have been described that are encoded in the telomeric end of the Class III region and that appear to be involved in both global and specific inflammatory responses.

Stereoselective synthesis of styrene oxides via a Mitsunobu cyclodehydration.

[reaction: see text] The Mitsunobu cyclodehydration of chiral phenethane-1,2-diols (4), readily accessed from the styrene derivative (5), has been demonstrated to provide the corresponding styrene oxides (2) with high levels of stereoretention (up to 99%). Optimized reaction conditions are described, from which the combination of tricyclohexylphosphine (Chx(3)P) and diisopropylazodicarboxylate (DIAD) in THF and R = EWG provides the best results.

Functional analysis of B144/LST1: a gene in the tumor necrosis factor cluster that induces formation of long filopodia in eukaryotic cells.

B144/LST1 is a gene encoded in the human major histocompatibility complex that produces multiple forms of alternatively spliced mRNA and encodes peptides fewer than 100 amino acids in length. B144/LST1 is strongly expressed in dendritic cells. Transfection of B144/LST1 into a variety of cells induces morphologic changes including the production of long, thin filopodia differing from those seen on transfection of a dominant active CDC42 gene.

Genomic and proteomic analysis of the myeloid differentiation program.

Although the mature neutrophil is one of the better characterized mammalian cell types, the mechanisms of myeloid differentiation are incompletely understood at the molecular level. A mouse promyelocytic cell line (MPRO), derived from murine bone marrow cells and arrested developmentally by a dominant-negative retinoic acid receptor, morphologically differentiates to mature neutrophils in the presence of 10 microM retinoic acid. An extensive catalog was prepared of the gene expression changes that occur during morphologic maturation.

BXMAS1 identifies a cluster of homologous genes differentially expressed in B cells.

Characterization of genes activated by anti-IgM crosslinking of BL2 cells identified one gene, designated BXMAS1, that is predicted to be a novel cell surface receptor. The time course of activation indicates maximal transcriptional induction after 24 h. The predicted protein contains 977 aa residues, with a cytoplasmic domain containing 2 ITIM motifs.

The homeodomain gene Pitx2 is expressed in primitive hematopoietic stem/progenitor cells but not in their differentiated progeny.

Objective: Hematopoietic stem cells (HSCs) represent a rare and incompletely characterized fraction of marrow cells that are capable of both self-renewal and differentiation into all of the mature cells in the peripheral blood. We undertook to identify genes expressed preferentially by HSCs as an initial step toward better understanding the molecular mechanisms that underlie HSC behavior.

Methods: We modified the representational difference analysis technique to isolate gene fragments present in amplified cDNA prepared from highly purified murine hematopoietic stem/progenitor cells (Lin(-)/Hoechst(low)/rhodamine(low)) and absent (or much less abundant) in amplified cDNA prepared from lineage-committed marrow cells.

Changing spectrum of mortality due to human immunodeficiency virus: analysis of 260 deaths during 1995--1999.

We analyzed the deaths in an outpatient human immunodeficiency virus (HIV) care clinic at University Hospitals in Cleveland from January 1995 through December 1999. The number of annual deaths decreased progressively, from 112 in 1995 to 32 in 1999. The median final CD4(+) cell count before death increased progressively from 10 cells/microL in 1995 to 90 cells/microL in 1999 (P<.

RNA expression patterns change dramatically in human neutrophils exposed to bacteria.

A comprehensive study of changes in messenger RNA (mRNA) levels in human neutrophils following exposure to bacteria is described. Within 2 hours there are dramatic changes in the levels of several hundred mRNAs including those for a variety of cytokines, receptors, apoptosis-regulating products, and membrane trafficking regulators. In addition, there are a large number of up-regulated mRNAs that appear to represent a common core of activation response genes that have been identified as early-response products to a variety of stimuli in a number of other cell types.

Mesenchymal stem cells are capable of homing to the bone marrow of non-human primates following systemic infusion.

Objective: The human bone marrow contains mesenchymal stem cells capable of differentiating along multiple mesenchymal cell lineages. Using a non-human primate model, we sought to determine whether the systemic infusion of baboon-derived mesenchymal stem cells was associated with toxicity and whether these cells were capable of homing to and persisting within the bone marrow.

Materials And Methods: Five baboons (Papio anubis) were administered lethal irradiation followed by intravenous autologous hematopoietic progenitor cells combined with either autologous (n = 3) or allogeneic (n = 2) mesenchymal stem cells that had been expanded in culture.

Cloning and characterization of two mouse genes with homology to the yeast Sir2 gene.

The yeast Sir2 gene encodes a protein (Sir2p) that plays an essential role in silencing regulation at mating-type loci, rDNA, and telomeres. Recent studies have also shown that the protein participates in cell cycle regulation, DNA double-strand break repair, meiotic checkpoint control, and histone deacetylation. Overexpression of wildtype Sir2p in yeast resulted in an extended life span but mutant Sir2p shortened the life span, suggesting its function in aging processes.

Werner protein recruits DNA polymerase delta to the nucleolus.

Werner syndrome is a Mendelian disorder of man that produces a number of manifestations resembling human aging. This disorder is caused by inactivation of the wrn gene, a member of the RecQ family of DNA helicases. The helicase and exonuclease activities of the Werner protein (WRN) suggest that it functions in DNA transactions, but the physiological function of WRN remains elusive.

Practical modifications and applications of the sharpless asymmetric aminohydroxylation in the one-pot preparation of chiral oxazolidin-2-ones.

[reaction: see text] Chiral oxazolidin-2-ones are synthetically valuable as chiral auxiliaries, and many have pharmaceutically interesting biological activity. This communication focuses on a convenient, practical one-pot preparation of chiral 4,5-disubstituted oxazolidan-2-ones in good yield with high enantioselectivities, using a modified Sharpless asymmetric aminohydroxylation of beta-substituted styrene derivatives followed by base-mediated ring closure. This procedure has been demonstrated on both small and large scale, utilizing 1, 3-dichloro-5,5-dimethyl hydantoin as an easily handled, commercially available substitute for tert-butyl hypochlorite.

Application of signature-tagged mutagenesis for identification of escherichia coli K1 genes that contribute to invasion of human brain microvascular endothelial cells.

Escherichia coli K1 is the leading cause of gram-negative bacterial meningitis in neonates. It is principally due to our limited understanding of the pathogenesis of this disease that the morbidity and mortality rates remain unacceptably high. To identify genes required for E.

Characterization of the promoter of human leukocyte-specific transcript 1. A small gene with a complex pattern of alternative transcripts.

The gene for the human leukocyte-specific transcript 1 (LST1) encodes a small protein that modulates immune responses and cellular morphogenesis. The LST1 transcripts are expressed at high levels in dendritic cells. Because of the complex splicing pattern, use of alternative 5'-untranslated exons, and a biologically interesting pattern of expression of LST1 mRNA, we studied the human LST1 gene promoter and regulatory elements.

Expression and cellular localization of the protein encoded by the 1C7 gene: a recently described component of the MHC.

The major histocompatibility complex (MHC) is located on human Chromosome 6 and includes clusters of class I, class II, and class III genes. Centromeric to the class I region is a cluster of genes designated as MHC class IV encoding genes involved in immunity and inflammation, including the 1C7 gene. The human 1C7 gene has several alternatively spliced forms and potentially codes for proteins with at least three unique carboxy termini.

WRN or telomerase constructs reverse 4-nitroquinoline 1-oxide sensitivity in transformed Werner syndrome fibroblasts.

WRN encodes a RecQ helicase, which is mutated in Werner syndrome. Werner syndrome is a genetic condition of young adults characterized by premature aging, limited replicative capacity of cells in vitro, and increased cancer risk. Telomerase is a reverse transcriptase that extends the G-rich strand of telomeric DNA.

Global analysis of neutrophil gene expression.

A widespread, but incorrect, view of the neutrophil portrays it as a short-lived, terminally differentiated cell that has a highly condensed nucleus and hence is unable to induce gene expression. However, these cells express mRNA encoding phagocytic receptors, modulate RNA synthesis in response to lectin stimulation or glucocorticoid treatment, and upregulate genes involved in phagocytic function, such as respiratory burst activity and cytokine secretion. Most studies of neutrophil gene expression have examined cytokine stimulation and have focused on a few specific genes of known interest, rather than the global genetic repertoire of the cell.