83 research outputs found
Association of IREB2 and CHRNA3 polymorphisms with airflow obstruction in severe alpha-1 antitrypsin deficiency
Background: The development of COPD in subjects with alpha-1 antitrypsin (AAT) deficiency is likely to be influenced by modifier genes. Genome-wide association studies and integrative genomics approaches in COPD have demonstrated significant associations with SNPs in the chromosome 15q region that includes CHRNA3 (cholinergic nicotine receptor alpha3) and IREB2 (iron regulatory binding protein 2). We investigated whether SNPs in the chromosome 15q region would be modifiers for lung function and COPD in AAT deficiency. Methods The current analysis included 378 PIZZ subjects in the AAT Genetic Modifiers Study and a replication cohort of 458 subjects from the UK AAT Deficiency National Registry. Nine SNPs in LOC123688, CHRNA3 and IREB2 were selected for genotyping. Fev percent of predicted and Fev/FVC ratio were analyzed as quantitative phenotypes. Family-based association analysis was performed in the AAT Genetic Modifiers Study. In the replication set, general linear models were used for quantitative phenotypes and logistic regression models were used for the presence/absence of emphysema or COPD. Results: Three SNPs (rs2568494 in IREB2, rs8034191 in LOC123688, and rs1051730 in CHRNA3) were associated with pre-bronchodilator Fev percent of predicted in the AAT Genetic Modifiers Study. Two SNPs (rs2568494 and rs1051730) were associated with the post-bronchodilator Fev percent of predicted and pre-bronchodilator Fev/FVC ratio; SNP-by-gender interactions were observed. In the UK National Registry dataset, rs2568494 was significantly associated with emphysema in the male subgroup; significant SNP-by-smoking interactions were observed. Conclusions: IREB2 and CHRNA3 are potential genetic modifiers of COPD phenotypes in individuals with severe AAT deficiency and may be sex-specific in their impact
Synthesis, characterization, DNA binding, topoisomerase inhibition, and apoptosis induction studies of a novel cobalt(III) complex with a thiosemicarbazone ligand
In this study, 9-anthraldehyde-N(4)-methylthiosemicarbazone (MeATSC) 1 and [Co(phen)(OCO)]Cl·6HO 2 (where phen = 1,10-phenanthroline) were synthesized. [Co(phen)(OCO)]Cl·6HO 2 was used to produce anhydrous [Co(phen)(HO)](NO)3. Subsequently, anhydrous [Co(phen)(HO)](NO)3 was reacted with MeATSC 1 to produce [Co(phen)(MeATSC)](NO)·1.5HO·CHOH 4. The ligand, MeATSC 1 and all complexes were characterized by elemental analysis, FT IR, UV-visible, and multinuclear NMR (H, C, and Co) spectroscopy, along with HRMS, and conductivity measurements, where appropriate. Interactions of MeATSC 1 and complex 4 with calf thymus DNA (ctDNA) were investigated by carrying out UV-visible spectrophotometric studies. UV-visible spectrophotometric studies revealed weak interactions between ctDNA and the analytes, MeATSC 1 and complex 4 (K = 8.1 × 10 and 1.6 × 10 M, respectively). Topoisomerase inhibition assays and cleavage studies proved that complex 4 was an efficient catalytic inhibitor of human topoisomerases I and IIα. Based upon the results obtained from the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay on 4T1-luc metastatic mammary breast cancer cells (IC = 34.4 ± 5.2 μM when compared to IC = 13.75 ± 1.08 μM for the control, cisplatin), further investigations into the molecular events initiated by exposure to complex 4 were investigated. Studies have shown that complex 4 activated both the apoptotic and autophagic signaling pathways in addition to causing dissipation of the mitochondrial membrane potential (ΔΨ). Furthermore, activation of cysteine-aspartic proteases3 (caspase 3) in a time- and concentration-dependent manner coupled with the ΔΨ, studies implicated the intrinsic apoptotic pathway as the major regulator of cell death mechanism
Phase 2 clinical trial of a recombinant adeno-associated viral vector expressing α1-antitrypsin: interim results
Recombinant adeno-associated virus (rAAV) vectors offer promise for the gene therapy of α(1)-antitrypsin (AAT) deficiency. In our prior trial, an rAAV vector expressing human AAT (rAAV1-CB-hAAT) provided sustained, vector-derived AAT expression for \u3e1 year. In the current phase 2 clinical trial, this same vector, produced by a herpes simplex virus complementation method, was administered to nine AAT-deficient individuals by intramuscular injection at doses of 6.0×10(11), 1.9×10(12), and 6.0×10(12) vector genomes/kg (n=3 subjects/dose). Vector-derived expression of normal (M-type) AAT in serum was dose dependent, peaked on day 30, and persisted for at least 90 days. Vector administration was well tolerated, with only mild injection site reactions and no serious adverse events. Serum creatine kinase was transiently elevated on day 30 in five of six subjects in the two higher dose groups and normalized by day 45. As expected, all subjects developed anti-AAV antibodies and interferon-γ enzyme-linked immunospot responses to AAV peptides, and no subjects developed antibodies to AAT. One subject in the mid-dose group developed T cell responses to a single AAT peptide unassociated with any clinical effects. Muscle biopsies obtained on day 90 showed strong immunostaining for AAT and moderate to marked inflammatory cell infiltrates composed primarily of CD3-reactive T lymphocytes that were primarily of the CD8(+) subtype. These results support the feasibility and safety of AAV gene therapy for AAT deficiency, and indicate that serum levels of vector-derived normal human AAT \u3e20 μg/ml can be achieved. However, further improvements in the design or delivery of rAAV-AAT vectors will be required to achieve therapeutic target serum AAT concentrations
Direct observation of topoisomerase IA gate dynamics
Type IA topoisomerases cleave single-stranded DNA and relieve negative supercoils in discrete steps corresponding to the passage of the intact DNA strand through the cleaved strand. Although type IA topoisomerases are assumed to accomplish this strand passage via a protein-mediated DNA gate, opening of this gate has never been observed. We developed a single-molecule assay to directly measure gate opening of the Escherichia coli type IA topoisomerases I and III. We found that after cleavage of single-stranded DNA, the protein gate opens by as much as 6.6 nm and can close against forces in excess of 16 pN. Key differences in the cleavage, ligation, and gate dynamics of these two enzymes provide insights into their different cellular functions. The single-molecule results are broadly consistent with conformational changes obtained from molecular dynamics simulations. These results allowed us to develop a mechanistic model of interactions between type IA topoisomerases and single-stranded DNA
Lion, Ungulate, and Visitor Reactions to Playbacks of Lion Roars at Zoo Atlanta
Felids in captivity are often inactive and elusive in zoos, leading to a frustrating visitor experience. Eight roars were recorded from an adult male lion and played back over speakers as auditory enrichment to benefit the lions while simultaneously enhancing the zoo visitor experience. In addition, ungulates in an adjacent exhibit were observed to ensure that the novel location and increased frequency of roars did not lead to a stress or fear response. The male lion in this study roared more in the playback phase than in the baseline phases while not increasing any behaviors that would indicate compromised welfare. In addition, zoo visitors remained at the lion exhibit longer during playback. The nearby ungulates never exhibited any reactions stronger than orienting to playbacks, identical to their reactions to live roars. Therefore, naturalistic playbacks of lion roars are a potential form of auditory enrichment that leads to more instances of live lion roars and enhances the visitor experience without increasing the stress levels of nearby ungulates or the lion themselves, who might interpret the roar as that of an intruder
Plasma cell malignancy in the acquired immune deficiency syndrome. Association with Epstein-Barr virus
The development of high-grade, malignant B-cell lymphoma is a well-recognized complication of human immunodeficiency virus (HIV) infection. Plasma cell neoplasms, however, have been rarely encountered in HIV-infected people. This study presents the morphologic and immunologic features of an unusual plasma cell tumor occurring in a 31-year-old HIV-antibody-positive male. The malignancy was characterized by widespread dissemination and hypercalcemia at presentation and a clinically aggressive course. Immunoperoxidase staining of tumor tissue obtained from biopsy and at autopsy had positive results for IgM and lambda. In the patient's serum, only an IgG kappa paraprotein was detected, indicating that the tumor was nonsecretory. DNA analysis of autopsy-derived tumor tissues demonstrated clonal rearrangements of the immunoglobulin (Ig) heavy chain gene locus and rearrangements in both kappa and lambda light chain gene loci. Furthermore, DNA hybridization studies revealed the presence of Epstein-Barr virus (EBV) genomes in tumor tissue but not in nontumor tissue from this patient
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