Design, synthesis and evaluation of human telomerase inhibitors based upon a tetracyclic structural motif

There is currently significant interest in the development of inhibitors of human telomerase for the treatment of cancer. We describe here the design and synthesis of a new class of mono-substituted small-molecule inhibitors of human telomerase based upon a tetracyclic structural motif. In contrast to the structurally related molecule 9-hydroxyellipticine, recently shown to inhibit telomerase activity in cell cultures but found to be inactive in a cell-free system, we demonstrate direct inhibition of the telomerase enzyme by the tetracyclic compounds in a modified cell-free TRAP assay. The most potent compounds exhibit activity in the low micromolar range and are thus comparable with some of the more active small-molecule telomerase inhibitors based on planar aromatic chromophores, previously described by ourselves and others. These compounds may represent useful leads for the development of more potent inhibitors of human telomerase.     

Achieving treatment goals for schoolchildren with asthma

OBJECTIVES: To identify problems in managing asthmatic children in school, which if dealt with would help reduce absenteeism and improve participation in school activities. DESIGN: A survey by questionnaire to headteachers. SETTING: Schools in Merthyr and Rhondda Cynon Taff, South Wales. SUBJECT: Asthmatic schoolchildren in areas studied. MAIN OUTCOME MEASURES: Facilities in schools to manage asthma, headteachers' perceptions of knowledge of asthma management by teachers, possession of written policies, and desire for further training. RESULTS: There are 216 schools in the area studied, with 55,166 schoolchildren. A total of 191 (88%) headteachers returned the completed questionnaire. Five hundred and twenty seven (17%) children were reported absent from school during one term because of asthma, with an average of nine days of schooling lost per asthmatic child per term (range 2-16 days). Only 76 (40%) schools allowed children to be responsible for their inhalers, and 12 (6%) schools required parents to administer inhalers. In 115 (60%) schools, headteachers believed their staff were familiar with the management of asthma. A total of 174 (91%) headteachers expressed interest in further training. CONCLUSION: This study highlights the need to train teachers and provide an agreed joint education and health policy on managing asthma in school.     

Bilateral adrenal non-Hodgkin's lymphoma with adrenal insufficiency

A 74 year old women presented with lethargy and weight loss and was found to have profound adrenal insufficiency and bilateral adrenal mass lesions. Histological examination revealed non-Hodgkin's lymphoma. There was no evidence of lymphoma outside the adrenal glands. Isolated bilateral adrenal masses may rarely be due to primary adrenal non-Hodgkin's lymphoma, which is often associated with adrenal insufficiency.     

Identification of differentially expressed genes in shrimp (<Emphasis Type="Italic">Penaeus stylirostris</Emphasis>) infected with <Emphasis Type="Italic">White spot syndrome virus</Emphasis> by cDNA microarrays

Summary. White spot syndrome virus (WSSV) is currently the most important viral pathogen infecting penaeid shrimp worldwide. Although considerable progress has been made in characterizing the WSSV genome and developing detection methods, information pertaining to host genes involved in WSSV pathogenesis is limited. We examined the potential of cDNA microarray analysis to study gene expression in WSSV-infected shrimp. Shrimp cDNAs were printed as low-density arrays on glass slides and were hybridized with Cy3/Cy5 labeled probes derived from RNA isolated from healthy and WSSV-infected shrimp. Genes that code for proteins that are relevant to crustacean immunity, structural proteins, as well as proteins of unknown function were among those whose mRNA expression was altered upon WSSV infection. To validate the microarray data, the temporal expression of three differentially expressed genes, an immune gene (C-type lectin-1), a structural gene (40S ribosomal protein), and a gene involved in lipid metabolism (fatty acid binding protein) was measured in healthy and WSSV-infected shrimp by real-time RT-PCR. The data suggest that WSSV infection alters the expression of a wide array of cellular genes, and provides a framework for further studies aimed at identifying genes whose function may provide insight into the mechanism of WSSV infection in shrimp.     

Cloning and characterization of chicken stromal cell derived factor-1

Stromal cell derived factor-1, SDF-1, belongs to the CXC family of chemokines and has been identified in mammals, amphibians, and fish. This chemokine has a diverse array of functions in organogenesis, hematopoeisis, B cell development and recruitment of immune system cells. Here, we report the cloning of the chicken SDF-1 ortholog and examine its temporal and spatial expression. The chicken SDF-1 cDNA contained an open reading frame encoding a predicted protein of 89 amino acids, which shared 40-75% identity to SDF-1 protein in other species. Protein folding simulation predicted a tertiary structure very similar to that obtained for human SDF-1. Recombinant chicken SDF-1 was produced using a prokaryotic expression system and the recombinant protein was shown to be biologically active in a calcium flux assay. The SDF-1 gene was found to be expressed ubiquitously and constitutively in adult tissues and was present as early as the primitive streak stage of chicken embryos.     

Copy Number of Pilus Gene Clusters in Haemophilus influenzae and Variation in the hifE Pilin Gene

Brazilian purpuric fever (BPF)-associated Haemophilus influenzae biogroup aegyptius strain F3031 contains two identical copies of a five gene cluster (hifA to hifE) encoding pili similar to well-characterized Hif fimbriae of H. influenzae type b. HifE, the putative pilus tip adhesin of F3031, shares only 40% amino acid sequence similarity with the same molecule from type b strains, whereas the other four proteins have 75 to 95% identity. To determine whether pilus cluster duplication and the hifE_F3031 allele were special features of BPF-associated bacteria, we analyzed a collection of H. influenzae strains by PCR with hifA- and hifE-specific oligonucleotides, by Southern hybridization with a hifC gene probe, and by nucleotide sequencing. The presence of two pilus clusters was limited to some H. influenzae biogroup aegyptius strains. The hifE_F3031 allele was limited to H. influenzae biogroup aegyptius. Two strains contained one copy of hifE_F3031 and one copy of a variant hifE allele. We determined the nucleotide sequences of four hifE genes from H. influenzae biogroup aegyptius and H. influenzae capsule serotypes a and c. The predicted proteins produced by these genes demonstrated only 35 to 70% identity to the three published HifE proteins from nontypeable H. influenzae, serotype b, and BPF strains. The C-terminal third of the molecules implicated in chaperone binding was the most highly conserved region. Three conserved domains in the otherwise highly variable N-terminal putative receptor-binding region of HifE were similar to conserved portions in the N terminus of Neisseria pilus adhesin PilC. We concluded that two pilus clusters and hifE_F3031 were not specific for BPF-causing H. influenzae, and we also identified portions of HifE possibly involved in binding mammalian cell receptors.     

In vitro antibody response of primed rabbit peripheral blood lymphocytes to group A variant streptococcal polysaccharide

Peripheral blood lymphocytes obtained from rabbits at various times after a primary course of immunization with streptococcal Group A-variant vaccines were successfully stimulated in vitro with this vaccine. Day 5 cultures contained about 81 % IgM and only 19 % IgG plaque-forming cells, day 10 cultures contained only 38 % IgM and 62 % IgG plaques, and day 15 cultures contained predominantly IgG plaques (83 %) and far fewer IgM plaques (17 %). Concomitantly, IgM and IgG secretion into the media was shown. Analysis of the secreted IgG antibodies by isoelectric focusing showed in principle that the clones stimulated in vitro were those that had determined the in vivo response. These data demonstrate the circulation of clonal progenitor cells in the rabbit peripheral blood.