Quantitative single-molecule microscopy reveals that CENP-A(Cnp1) deposition occurs during G2 in fission yeast

The inheritance of the histone H3 variant CENP-A in nucleosomes at centromeres following DNA replication is mediated by an epigenetic mechanism. To understand the process of epigenetic inheritance, or propagation of histones and histone variants, as nucleosomes are disassembled and reassembled in living eukaryotic cells, we have explored the feasibility of exploiting photo-activated localization microscopy (PALM). PALM of single molecules in living cells has the potential to reveal new concepts in cell biology, providing insights into stochastic variation in cellular states. However, thus far, its use has been limited to studies in bacteria or to processes occurring near the surface of eukaryotic cells. With PALM, one literally observes and 'counts' individual molecules in cells one-by-one and this allows the recording of images with a resolution higher than that determined by the diffraction of light (the so-called super-resolution microscopy). Here, we investigate the use of different fluorophores and develop procedures to count the centromere-specific histone H3 variant CENP-A(Cnp1) with single-molecule sensitivity in fission yeast (Schizosaccharomyces pombe). The results obtained are validated by and compared with ChIP-seq analyses. Using this approach, CENP-A(Cnp1) levels at fission yeast (S. pombe) centromeres were followed as they change during the cell cycle. Our measurements show that CENP-A(Cnp1) is deposited solely during the G2 phase of the cell cycle

The impact of vancomycin susceptibility on treatment outcomes among patients with methicillin resistant Staphylococcus aureus bacteremia

<p>Abstract</p> <p>Background</p> <p>Management of methicillin-resistant <it>Staphylococcus aureus </it>(MRSA) bacteremia remains a challenge. The emergence of MRSA strains with reduced vancomycin susceptibility complicates treatment.</p> <p>Methods</p> <p>A prospective cohort study (2005-2007) of patients with MRSA bacteremia treated with vancomycin was performed at an academic hospital. Vancomycin minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined for stored MRSA isolates. Cox regression analysis was performed to predict 28-day all-cause mortality.</p> <p>Results</p> <p>One hundred sixty-three patients with MRSA bacteremia were evaluated. One hundred twelve patients (68.7%) had bacteremia due to MRSA with a vancomycin MIC ≥ 2 <it>ug</it>/mL. Among strains with a vancomycin MIC ≥ 2 <it>ug</it>/mL, 10 isolates (8.9%) were vancomycin-intermediate <it>S. aureus </it>(VISA). Thirty-five patients (21.5%) died within 28 days after the diagnosis of MRSA bacteremia. Higher vancomycin MIC was not associated with mortality in this cohort [adjusted hazard ratio (aHR), 1.57; 95% confidence interval (CI), 0.73-3.37]. Vancomycin tolerance was observed in 4.3% (7/162) of isolates and was not associated with mortality (crude HR, 0.62; 95% CI, 0.08-4.50). Factors independently associated with mortality included higher age (aHR, 1.03; 95% CI 1.00-1.05), cirrhosis (aHR, 3.01; 95% CI, 1.24-7.30), and intensive care unit admission within 48 hours after the diagnosis of bacteremia (aHR, 5.99; 95% CI, 2.86-12.58).</p> <p>Conclusions</p> <p>Among patients with MRSA bacteremia treated with vancomycin, reduced vancomycin susceptibility and vancomycin tolerance were not associated with mortality after adjusting for patient factors. Patient factors including severity of illness and underlying co-morbidities were associated with the mortality.</p

Comparison of HIV-1 viral loads, CD4-Th2-lymphocytes and effects of praziquantel treatment among adults infected or uninfected with Schistosoma mansoni in fishing villages of north-western Tanzania

 Background: It is hypothesised that Th2 immunological environment associated with Schistosoma mansoni infection might favour replication of HIV-1 in co-infected individuals, results in increased viral loads. On the other hand, deworming using praziquantel might result in reduction of HIV-1 viral loads and increased CD4+ cell counts. This study was therefore, carried out to compare HIV -1 plasma loads, CD4-Th2-lymphocytes and the effects of praziquantel treatment on HIV-1 plasma loads and CD4+ cell counts among HIV-1 seropositive individuals infected or uninfected with S. mansoni.Methodology: A 9-month prospective longitudinal study was conducted among HIV-1 infected individuals aged 21-55 years with CD4+ cell counts ≥ 350cells/µL in fishing villages of North-Western Tanzania. Single stool samples were examined for S. mansoni eggs using Kato Katz technique at 6-month follow-up and 12 weeks after treatment. Venous blood samples were collected at baseline, at three and six-month follow-up and 12 weeks after praziquantel treatment for HIV-1 plasma viral loads and CD4+ cell quantification.Results: Of the 50 HIV-1 infected participants at baseline, 44% (22/50, 95%CI; 30.58-58.35) were found to be co-infected with S. mansoni at 6-month follow-up with a mean of 93.26GM-epg (95%CI: 60.42-143.95). The median CD4+ cell counts did not differ significantly between individuals infected with HIV-1 and those co-infected with HIV-1 and S. mansoni at baseline (P=0.62), 3-month (P=0.64) and 6-month (P=0.41) follow-up. Monthly decrease in CD4+ cells did not differ significantly between the two groups at all follow-up points (-30.39cell/µL versus -31.35cells/µL, P=0.89). Those infected with S. mansoni had a significantly higher mean log10 HIV-1 plasma viral load at baseline (5.98 ± 3.06 versus 9.21 ± 1.91copies/ml, P&lt;0.0001) and 3-month follow-up (8.19 ± 2.17 versus 9.44 ± 1.99copies/ml, P&lt;0.042) compared to those infected with HIV-1 only. This difference was not evident at the time of S. mansoni diagnosis at 6-month time point. Praziquantel treatment in co-infected individuals (n=12) did not result in any change in CD4+ cell counts and mean HIV-1 plasma viral loads (t=-0.9156, P=0.38), comparing baseline and 3-month follow-up after treatment. No correlation was observed between log S. mansoni egg counts and log10 HIV-1 RNA viral loads (r=-0.066, P=0.77) at six-month follow-up in co-infected individuals (n=22).Conclusion: HIV-1 plasma viral loads varied significantly among mono and co-infected individuals at baseline and 3-month follow-up. However, CD4+ cell counts did not vary between the two groups at all follow-up time points. Praziquantel treatment of co-infected individuals did not result in changes in CD4+ cell counts and HIV-1 plasma viral loads

The impact of the introduction of IFRS on corporate annual reports and accounts in the UK

From 1 January 2005, all EU-listed firms are required to prepare their consolidated financial statements in accordance with International Financial Reporting Standards(IFRS) (EU, 2002). This requirement represents one of the most fundamental changes to affect financial reporting in recent times. This dissertation is an examination of the introduction and impact of IFRS on the annual report and accounts of UK companies in an attempt to investigate the decision-usefulness of the new IFRS disclosures. This examination is facilitated in three ways: (i) a content analysis is undertaken to investigate the magnitude and nature of the changes in IFRS-related disclosure presented in annual report and accounts produced prior to and following the introduction of IFRS; (ii) an analysis of the Reconciliation Statements produced upon first-time adoption of IFRS included in corporate annual reports to examine the impact on both profit and equity as a result of the transition from previous national GAAP to reporting in accordance with IFRS; and, (iii) an assessment of the new IFRS disclosures against the qualitative characteristics outlined in the IASB Decision-Usefulnessfr amework. In other words, it is an investigation of whether the claims of the IASI3 about the usefulness of the mandated IFRS disclosures for decision-makers are supported in practice with the contents of corporate annual reports and accounts in the UK.The results of the content analysis indicate that the implementation of IFRS had a significant impact on the content of the annual report and accounts of UK companies.The amount of disclosure in company annual reports increased significantly following the introduction of the new reporting regime. Furthermore, there was a large increase in the physical size of the annual reports for the vast majority of the firms surveyed. The scale of the impact varied from standard to standard, however, the nature and magnitude of the information presented in UK-published annual reports has been fundamentally impacted by the introduction of IFRS. The Reconciliation Statement analysis results reveal that profit disclosed under UK GAAP increased by 105.85 per cent following the implementation of IFRS. In addition, the results show that the introduction of IFRS had a significant impact on reported equity; however, there was an almost even split between those which experienced a favourable impact following the transition and those disclosing a negative effect on the balance sheet post-IFRS adoption. The main IFRS standards which impacted reported results under previous national GAAP were IAS 10, IAS 12, IAS 19, IAS 40 and the IFRS 3/1AS 36/IAS 38 group of standards.The assessmenot f the decision-usefulness of the new IFRS information reveals that the widespread variation in impact on reported results, the complexity of the supplementary narrative disclosures, absence of company-specific and forward-looking information, uncertainty about the long-term impact of the changeover and the lack of comparability between the Reconciliation Statements will likely have constrained the usefulness of the new disclosures for users and therefore their investment decisions. Thus, one of the aims of the standard setters does not seem to have been achieved as users of UK corporate annual reports were not supplied with more useful information about these companies compared to what was previously disclosed under UK GAAP.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Schistosoma mansoni Infection and Its Related Morbidity among Adults Living in Selected Villages of Mara Region, North-Western Tanzania: A Cross-Sectional Exploratory Study.

Schistosoma mansoni is highly endemic in Tanzania and affects all age groups at different degrees. However, its control approach does not include adult individuals who are equally at risk and infected. To justify the inclusion of adult individuals in MDA programs in Tanzania, the present study focused on determining the prevalence of S. mansoni infection and its related morbidities among adult individuals. This was a cross sectional study conducted among 412 adult individuals aged 18-89 years living in selected villages of Rorya and Butiama districts located along the shoreline of the Lake Victoria. A pretested questionnaire was used to collect socio-demographic and socio-economic information of participants. Ultrasonographic examinations were conducted for all study participants using the Niamey protocol. A single stool sample was obtained from all study participants and examined for S. mansoni using the Kato-Katz technique. The study revealed a high prevalence of S. mansoni (56.3%), and the majority of infected individuals had a light intensity of infection. Ultrasonographic findings revealed that 22.4% of adult individuals had periportal fibrosis (PPF) (grade C-F), with 18.4% having grade C and D and 4% having grade E and F. Males had the highest prevalence of PPF (31.7% vs 10.8%, P<0.001). Organomegaly was common with 28.5% and 29.6% having splenomegaly and hepatomegaly, respectively. S. mansoni infection and its related morbidities included PPF, hepatomegaly, and splenomegaly were common among adult individuals. To reduce the level of transmission of S. mansoni infection, planned mass drug administration campaigns should include adult individuals living in these villages

Operative and Radiographic Acetabular Component Orientation in Total Hip Replacement: Influence of Pelvic Orientation and Surgical Positioning Technique

Orthopaedic surgeons often experience a mismatch between perceived intra-operative and radiographic acetabular cup orientation. This research aimed to assess the impact of pelvic orientation and surgical positioning technique on operative and radiographic cup orientation. Radiographic orientations for two surgical approaches were computationally simulated: a mechanical alignment guide and a transverse acetabular ligament approach, both in combination with different pelvic orientations. Positional errors were defined as the difference between the target radiographic orientation and that achieved. The transverse acetabular ligament method demonstrated smaller positional errors for radiographic version; 4.0° ± 2.9° as compared to 9.4° ± 7.3° for the mechanical alignment guide method. However, both methods resulted in similar errors in radiographic inclination. Multiple regression analysis showed that intraoperative pelvic rotation about the anterior-posterior axis was a strong predictor for these errors (B TAL = −0.893, B MAG = −0.951, p &lt; 0.01). Application of the transverse acetabular ligament method can reduce errors in radiographic version. However, if the orthopaedic surgeon is referencing off the theatre floor to control inclination when operating in lateral decubitus, this is only reliable if the pelvic sagittal plane is horizontal. There is currently no readily available method for ensuring that this is the case during total hip replacement surgery. </p

DySCo: Quantitating Associations of Membrane Proteins Using Two-Color Single-Molecule Tracking

We present a general method called dynamic single-molecule colocalization for quantitating the associations of single cell surface molecules labeled with distinct autofluorescent proteins. The chief advantages of the new quantitative approach are that, in addition to stable interactions, it is capable of measuring nonconstitutive associations, such as those induced by the cytoskeleton, and it is applicable to situations where the number of molecules is small