Genetic mobility and instability of retroviral vector in vector producer cells for gene therapy

A primary biosafety issue of retroviral vector-mediated gene therapy is the genetic instability of retroviral vectors. Reverse transcription of vector RNA genome is initiated by viral reverse transcriptase (RT) in a virion particle after infection of a target cell. During reverse transcription, abnormal template switches between vector and occasionally co-packaged helper virus in a virion particle can therefore enable helper virus to regain replication elements from the vector and revert to replication-competent retrovirus (RCR). This research was undertaken to study the origins of RT enzyme activities and test the hypothesis that RT enzyme activities are contributed by both exogenous RT, which is imported by the re-infection of vector virions, and endogenous RT, which is provided by intracellular vector virion particles. Superinfection of vector in vector producer cells (VPC) can increase the number of integrated vectors in VPC, and is mainly caused by decreased Env-receptor interference, a consequence of helper virus gene inactivation by host DNA methylation at the 5\u27 LTR promoter region. Suppression of helper virus gene expression by DNA methylation also reduces vector production. A chimeric retroviral helper virus combined with picornavirus IRES (internal ribosome entry site) sequence and a selection marker was therefore constructed to eliminate DNA methylated helper virus from cell populations to maintain active gene expression and enhance Env-receptor interference. Packaging cells established by this chimeric helper virus exhibit high titer production without detectable superinfection. In addition to exogenous RT activities imported by superinfection, significant endogenous RT activities (0.2% to 7.8% of exogenous RT activity), which originates from viral precursor protein Pr180gag-pol, were also demonstrated by intracellular retrotransposition of a retroviral vector in VPC. Retrotransposed vectors can integrate into different chromosomal locations to increase the plasticity of the VPC genome as observed from superinfected vectors. The outcomes from this study provide important insights for further strategies designed to prevent RCR formation by inactivation of RT activity. Demonstration of intracellular retrotransposition of retroviral vectors in VPC may reveal an alternative replication pathway of retrovirus

Optimal Quantum State Estimation with Use of the No-Signaling Principle

A simple derivation of the optimal state estimation of a quantum bit was obtained by using the no-signaling principle. In particular, the no-signaling principle determines a unique form of the guessing probability independently of figures of merit, such as the fidelity or information gain. This proves that the optimal estimation for a quantum bit can be achieved by the same measurement for almost all figures of merit.Comment: 3 pages, 1 figur

Improvement of retinoids production in recombinant E. coli using glyoxylic acid

Isoprenoids are the most chemically diverse compounds found in nature. They are present in all organisms and have essential roles in membrane structure, redox chemistry, reproductive cycles, growth regulation, signal transduction and defense mechanisms. In spite of their diversity of functions and structures, all isoprenoids are derived from the common building blocks of isopentenyl diphosphate (IPP) and its isomer dimethylallyl diphosphate (DMAPP). Optimization of IPP synthesis pathway is of benefit to mass production of various isoprenoids. There are two pathways of 2-C-Methyl-D-erythritol-4-phosphate (MEP) and mevalonate (MVA) for IPP synthesis. Prokaryotes including E. coli generally use MEP pathway whereas MVA pathway is used in eukaryotes. To improve isoprenoid production, it was performed the deletion of genes in E. coli, which are involved in both formation of fermentation by-products such as organic acids and alcohols, and consumption of precursors of MEP and MVA pathways, pyruvate and acetyl-CoA. As a result, we were able to develop a strain with improved fermentation productivity and carbon source utilization efficiency, the mutant strain was called AceCo. Higher lycopene production was achieved in the AceCo strain compared to the wild type MG1655 strain due to no formation of the inhibitory by-products. However, retinoids production of AceCo strain decreased to a half of that of MG1655 strain. Please click Additional Files below to see the full abstract

Refinement of Under-Determined Loops of Human Prion Protein by Database-Derived Distance Constraints

Computational simulations of the conversion from the normal cellular prion (PrPc) to the scrapie prion (PrPSc) are usually based on the structures determined by NMR because of the difficulties in crystallizing prion protein. Due to insufficient experimental restraints, a biologically critical loop region in PrPc (residues 167–171), which is a potential binding site for Protein X, is under-determined in most mammalian species. Here, we show that by adding information about distance constraints derived from a database of high-resolution protein structures, this under-determined loop as well as other secondary structural elements of the E200K variant of human prion protein (hPrPc), a disease-related isoform, can be refined into more realistic structures in the structural ensemble with improved quality and increased accuracy. In particular, the ensemble becomes more compact after the refinement and the percentage of residues in the most favourable region of the Ramachandran diagram is increased to about 90% in the refined structures from the 80 to 85% range in the previously reported structures. Our results not only provide significantly improved structures of the prion protein and hence would facilitate insights into its conversion in the spongiform encephalopathies, but also demonstrate the strong potential for using databases of known protein structures for structure determination and refinement

NFATc1 regulates the transcription of DNA damage-induced apoptosis suppressor

AbstractDNA damage induced apoptosis suppressor (DDIAS), or human Noxin (hNoxin), is strongly expressed in lung cancers. DDIAS knockdown induced apoptosis in non-small cell lung carcinoma A549 cells in response to DNA damage, indicating DDIAS as a potential therapeutic target in lung cancer. To understand the transcriptional regulation of DDIAS, we determined the transcription start site, promoter region, and transcription factor. We found that DDIAS transcription begins at nucleotide 212 upstream of the DDIAS translation start site. We cloned the DDIAS promoter region and identified NFAT2 as a major transcription factor (Im et al., 2016 [1]). We demonstrated that NFATc1 regulates DDIAS expression in both pancreatic cancer Panc-1 cells and lung cancer cells

Causes and effects of 2008 financial crisis

Beginning in the mid 2007’s the US financial market started to slide into the “worst financial crisis since the Great Depression of the early 1930’s” (Thakor, 2015: p.156). The domino effect of several events and occasions were leading first to a countrywide recession in the USA then later spreading globally. In the following this term paper will deal with the main causes and effects of 2008 financial crisis. Unlike other topics in literature there is no consensus about the question of guilt in this sense. Among economists there are different approaches to explain the main causes of the financial crisis

Psychometric Properties of the Hypomania Checklist-32 in Korean Patients with Mood Disorders

OBJECTIVE The aim of this study was to examine the validity of the Korean version of the Hypomania Checklist-32, second revision (HCL-32-R2) in mood disorder patients. METHODS A total of 454 patients who diagnosed as mood disorder according to Structured Clinical Interview for DSM-IV Axis I Disorders, clinician version (SCID-CV) (bipolar disorder [BD] I, n=190; BD-II, n=72; and major depressive disorder [MDD], n=192) completed the Korean module of the HCL-32-R2 (KHCL-32-R2). RESULTS The KHCL-32-R2 showed a three-factorial structure (eigenvalue ＞2) that accounted for 43.26% of the total variance. Factor 1 was labeled "active/elated" and included 16 items; factor 2, "irritable/distractible" and included 9 items; and factor 3 was labeled "risk-taking/indulging" and included 9 items. A score of 16 or more on the KHCL-32-R2 total scale score distinguished between BD and MDD, which yielded a sensitivity of 70% and a specificity of 70%. MDD and BD-II also could be differentiated at a cut-off of 15 with maximized sensitivity (0.67) and specificity (0.66). Cronbach's alpha of KHCL-32-R2 and its subsets (factors 1, 2, and 3) were 0.91, 0.89, 0.81 and 0.79, respectively. Correlations between KHCL-32-R2 and Montgomery- Asberg Depression Rating Scale, Young Mania Rating Scale and Korean version of Mood Disorder Questionnaire were -0.66 (p=0.41), -0.14 (p=0.9), and 0.61 (p＜0.001), respectively. CONCLUSION The KHCL-32-R2 may be a useful tool in distinguishing between bipolar and depressive patients in clinical settings

Successful Radiofrequency Catheter Ablation for Wolff-Parkinson-White Syndrome Within the Neck of a Coronary Sinus Diverticulum

Posteroseptal accessory pathways are often associated with coronary sinus diverticula. These diverticula contain myocardial coats which serve as a bypass tract. We report a 54-year-old woman who underwent radiofrequency (RF) catheter ablation for Wolff-Parkinson-White (WPW) syndrome. The surface electrocardiography (ECG) demonstrated pre-excitation, indicating a posteroseptal accessory pathway. A catheter ablation via a transaortic approach failed to ablate the accessory pathway. Coronary sinus venography revealed the presence of a diverticulum near the ostium. An electrogram in the neck of the diverticulum showed the coronary sinus myocardial extension potential, which was successfully ablated by delivery of RF energy

Evaluation of changes in random blood glucose and body mass index during and after completion of chemotherapy in children with acute lymphoblastic leukemia

PurposeImproved survival of patients with childhood acute lymphoblastic leukemia (ALL) has drawn attention to the potential for late consequences of previous treatments among survivors, including metabolic syndrome. In this study, we evaluated changes in 3 parameters, namely, random blood glucose, body mass index (BMI), and Z score for BMI (Z-BMI), in children with ALL during chemotherapy and after completion of treatment.MethodsPatients newly diagnosed with ALL from January, 2005 to December, 2008 at Saint Mary's Hospital, The Catholic University of Korea, who completed treatment with chemotherapy only were included (n=107). Random glucose, BMI, and Z-BMI were recorded at 5 intervals: at diagnosis, before maintenance treatment, at completion of maintenance treatment, and 6 and 12 months after completion of maintenance treatment. Similar analyses were conducted on 2 subcohorts based on ALL risk groups.ResultsFor random glucose, a paired comparison showed significantly lower levels at 12 months post-treatment compared to those at initial diagnosis (P<0.001) and before maintenance (P<0.001). The Z-BMI score was significantly higher before maintenance than at diagnosis (P<0.001), but decreased significantly at the end of treatment (P<0.001) and remained low at 6 months (P<0.001) and 12 months (P<0.001) post-treatment. Similar results were obtained upon analysis of risk group-based subcohorts.ConclusionFor a cohort of ALL patients treated without allogeneic transplantation or cranial irradiation, decrease in random glucose and Z-BMI after completion of chemotherapy does not indicate future glucose intolerance or obesity

Induction chemotherapy in head and neck squamous cell carcinoma of the paranasal sinus and nasal cavity: A role in organ preservation

Background/Aims: The role of induction chemotherapy (IC) for eyeball preservation has not been established in head and neck squamous cell carcinoma (HNSCC) of the paranasal sinus and nasal cavity (PNSNC). Periorbital involvement frequently leads to eyeball exenteration with a margin of safety. We evaluated the treatment outcomes, including survival and eyeball preservation, of patients who received IC for HNSCC of the PNSNC. Methods: We reviewed 21 patients diagnosed with HNSCC of the PNSNC who were treated with IC. We analyzed response, eyeball preservation rate, and overall survival. Results: Tumors were located in the paranasal sinus (n = 14) or nasal cavity (n = 7). Most patients had stage T4a (n = 10) or T4b (n = 7) disease. More than half of the patients received a chemotherapy regimen of docetaxel, fluorouracil, and cisplatin (n = 11). Thirteen patients (61.9%) achieved a partial response after IC and 15 patients (71.4%) achieved T down-staging. Among 17 patients with stage T4 disease, which confers a high risk of orbital exenteration, 14 (82.4%) achieved preservation of the involved eye. The 3-year overall survival (OS) rate of patients who achieved a partial response to IC was 84.6%. The 3-year OS rate of patients with stable disease or disease progression after IC was 25.0% (p = 0.038). Conclusions: IC could be considered for down-staging patients with advanced T-stage disease. It could also be a reasonable option for eyeball preservation in locally advanced HNSCC of the PNSNC.