Chlamydia trachomatis: quantification, immunological investigation and co-infection with HIV-1

Three aspects of Chlamydia trachomatis translational research were explored in this thesis. Firstly, as over 75% of patients with LGV are also HIV-1 sero-positive, a cell-culture model was established to investigate whether HIV-1 altered the replication of C. trachomatis serovar L2 in vitro. Inclusion size was significantly increased in the presence of HIV-1, but there was no significant alteration in chlamydial growth kinetics, infectivity, morphology, or transcription of 16sRNA, ompA or euo, suggesting that viral co-infection did not induce chlamydial persistence. It is, therefore, unlikely that the association of HIV-1 and LGV in vivo is due to an impact of HIV-1 on chlamydial replication in co-infected cells. Secondly, as there is no information on the chlamydial load shed by individuals with a rectal C. trachomatis infection, a qPCR assay was developed and used to determine the number of C. trachomatis organisms per rectal swab in NAAT-positive patients. The geometric mean chlamydial load was 5.0 x 105 organisms per swab (Standard Deviation, 152) and load was associated with proctitis, but not symptoms or HIV-1 infection. Asymptomatic individuals shed as much C. trachomatis as patients with rectal symptoms and might maintain transmission in the community. Finally, an ex vivo IFN-γ ELISpot assay was developed to characterise human cellular immune responses to the C. trachomatis-specific protein, Pgp3. T-cell epitopes were found along the length of the protein, but the magnitude of the immune responses was low. The Pgp3- induced IFN-γ response correlated with C. trachomatis exposure and was dynamic, decreasing after effective treatment. These observations suggest that Pgp3- induced IFN-γ may be useful as a biomarker for current infection, although the sensitivity and specificity of the ELISpot assay need improvement

Improving Einstein-Podolsky-Rosen Steering Inequalities with State Information

We discuss the relationship between entropic Einstein-Podolsky-Rosen (EPR)-steering inequalities and their underlying uncertainty relations, along with the hypothesis that improved uncertainty relations lead to tighter EPR-steering inequalities. In particular, we discuss how the intrinsic uncertainty in a mixed quantum state is used to improve existing uncertainty relations and how this information affects one's ability to witness EPR-steering. As an example, we consider the recent improvement (using a quantum memory) to the entropic uncertainty relation between pairs of discrete observables (Nat. Phys. 6, 659 (2010)) and show that a trivial substitution of the tighter bound in the steering inequality leads to contradictions, due in part to the fact that the improved bound depends explicitly on the state being measured. By considering the assumptions that enter into the development of a steering inequality, we derive correct steering inequalities from these improved uncertainty relations and find that they are identical to ones already developed (Phys. Rev. A, 87, 062103 (2013)). In addition, we consider how one can use the information about the quantum state to improve our ability to witness EPR-steering, and develop a new symmetric EPR-steering inequality as a result.Comment: 6 page

Uncertainty Relation for Mutual Information

We postulate the existence of a universal uncertainty relation between the quantum and classical mutual informations between pairs of quantum systems. Specifically, we propose that the sum of the classical mutual information, determined by two mutually unbiased pairs of observables, never exceeds the quantum mutual information. We call this the complementary-quantum correlation (CQC) relation and prove its validity for pure states, for states with one maximally mixed subsystem, and for all states when one measurement is minimally disturbing. We provide results of a Monte Carlo simulation suggesting the CQC relation is generally valid. Importantly, we also show that the CQC relation represents an improvement to an entropic uncertainty principle in the presence of a quantum memory, and that it can be used to verify an achievable secret key rate in the quantum one-time pad cryptographic protocol.Comment: 6 pages, 2 figure

EPR Steering Inequalities from Entropic Uncertainty Relations

We use entropic uncertainty relations to formulate inequalities that witness Einstein-Podolsky-Rosen (EPR) steering correlations in diverse quantum systems. We then use these inequalities to formulate symmetric EPR-steering inequalities using the mutual information. We explore the differing natures of the correlations captured by one-way and symmetric steering inequalities, and examine the possibility of exclusive one-way steerability in two-qubit states. Furthermore, we show that steering inequalities can be extended to generalized positive operator valued measures (POVMs), and we also derive hybrid-steering inequalities between alternate degrees of freedom.Comment: 10 pages, 2 figure

Improving Einstein–Podolsky–Rosen Steering Inequalities with State Information

We discuss the relationship between entropic Einstein–Podolsky–Rosen (EPR)-steering inequalities and their underlying uncertainty relations along with the hypothesis that improved uncertainty relations lead to tighter EPR-steering inequalities. In particular, we discuss how using information about the state of a quantum system affects oneʼs ability to witness EPR-steering. As an example, we consider the recent improvement to the entropic uncertainty relation between pairs of discrete observables (Berta et al., 2010 [10]). By considering the assumptions that enter into the development of a steering inequality, we derive correct steering inequalities from these improved uncertainty relations and find that they are identical to ones already developed (Schneeloch et al., 2013 [9]). In addition, we consider how one can use state information to improve our ability to witness EPR-steering, and develop a new continuous variable symmetric EPR-steering inequality as a result

Health state utility values for diabetic retinopathy: protocol for a systematic review and meta-analysis

Background People with diabetic retinopathy tend to have lower levels of health-related quality of life than individuals with no retinopathy. Strategies for screening and treatment have been shown to be cost-effective. In order to reduce the bias in cost-effectiveness estimates, systematic reviews of health state utility values (HSUVs) are crucial for health technology assessment and the development of decision analytic models. A review and synthesis of HSUVs for the different stages of disease progression in diabetic retinopathy has not previously been conducted. Methods/Design We will conduct a systematic review of the available literature that reports HSUVs for people with diabetic retinopathy, in correspondence with current stage of disease progression and/or visual acuity. We will search Medline, EMBASE, Web of Science, Cost-Effectiveness Analysis Registry, Centre for Reviews and Dissemination Database, and EconLit to identify relevant English-language articles. Data will subsequently be synthesized using linear mixed effects modeling meta-regression. Additionally, reported disease severity classifications will be mapped to a four-level grading scale for diabetic retinopathy. Discussion The systematic review and meta-analysis will provide important evidence for future model-based economic evaluations of technologies for diabetic retinopathy. The meta-regression will enable the estimation of utility values at different disease stages for patients with particular characteristics and will also highlight where the design of the study and HSUV instrument have influenced the reported utility values. We believe this protocol to be the first of its kind to be published

Orthodontists? preference on type of rigid fixed functional appliance for skeletal Class II correction : a survey study

Rigid fixed functional appliances are most commonly used to correct skeletal Class II malocclusions. The objective of this study was to assess orthodontists? preference of different rigid fixed functional appliances used in the U.S.A for correction of skeletal Class II malocclusions. A survey on use and preference of rigid fixed functional appliances for skeletal Class II correction was emailed to 2,227 members of the American Association of Orthodontists (AAO) in the U.S.A. Frequency distribution of different responses and their association with demographic factors was assessed. Out of 140 orthodontists completing the survey, 110 responded as using rigid fixed functional appliances. Eight incomplete responses were eliminated from data analysis. 51.5% (68/132) orthodontists used rigid fixed functional appliances. The most preferred rigid fixed functional appliance was the Herbst appliance with 72% response followed by Mandibular Anterior Repositioning Appliance (24%) and AdvanSync (4%). There was no statistically significant difference in use of rigid fixed functional appliances between different age groups (p=0.284). However, the 40-54 age group used the most rigid fixed functional appliances in practice, followed by the 25-39 year age group and the 55-69 age group using these appliances the least. There was statistical significance between the type of practice setting one works in and the use of rigid fixed functional appliances in practice (p=0.022). About 52% of orthodontists use rigid fixed functional appliances to correct skeletal Class II malocclusions. The Herbst appliance is the most commonly used and most preferred amongst all rigid fixed functional appliances with a 72% preferred rate

Transcriptome Analysis of \u3ci\u3eBifidobacterium Longum\u3c/i\u3e Strains that Show a Differential Response to Hydrogen Peroxide Stress

Consumer and commercial interest in foods containing probiotic bifidobacteria is increasing. However, because bifidobacteria are anaerobic, oxidative stress can diminish cell viability during production and storage of bioactive foods. We previously found Bifidobacterium longum strain NCC2705 had signifi- cantly greater intrinsic and inducible resistance to hydrogen peroxide (H2O2) than strain D2957. Here, we explored the basis for these differences by examining the transcriptional responses of both strains to sub-lethal H2O2 exposure for 5- or 60-min. Strain NCC2705 had 288 genes that were differentially expressed after the 5-min treatment and 114 differentially expressed genes after the 60-min treatment. In contrast, strain D2957 had only 21 and 90 differentially expressed genes after the 5- and 60-min treatments, respectively. Both strains showed up-regulation of genes coding enzymes implicated in oxidative stress resistance, such as thioredoxin, thioredoxin reductase, peroxiredoxin, ferredoxin, glutaredoxin, and anaerobic ribonucleotide reductase, but induction levels were typically highest in NCC2705. Compared to D2957, NCC2705 also had more up-regulated genes involved in transcriptional regulation and more down-regulated genes involved in sugar transport and metabolism. These results provide a greater understanding of the molecular basis for oxidative stress resistance in B. longum and the factors that contribute to strain-to-strain variability in survival in bioactive food products