Serological surveys have been conducted to establish prevalence for COVID-19 antibodies in various cohorts and communities, reporting a wide range of outcomes. The prevalence of such antibodies among ...healthcare workers, presumed at higher risk for infection, has been increasingly investigated, more studies are needed to better understand the risks and infection transmission in different healthcare settings. The present study reports on initial sero-surveillance conducted on healthcare workers at a regional hospital system in Orange County, California, during May and June, 2020. Study subjects were recruited from the entire hospital employee workforce and the independent medical staff. Data were collected for job duties and locations, COVID-19 symptoms, a PCR test history, travel record since January 2020, and existence of household contacts with COVID-19. A blood sample was collected from each subject for serum analysis for IgG antibodies to SARS-CoV-2. Of 2,992 tested individuals, a total 2,924 with complete data were included in the analysis. Observed prevalence of 1.06% (31 antibody positive cases), adjusted prevalence of 1.13% for test sensitivity and specificity were identified. Significant group differences between positive vs. negative were observed for age (z = 2.65, p = .008), race (p = .037), presence of fever (p < .001), and loss of smell (p < .001), but not for occupations (p = .710). Possible explanation for this low prevalence includes a relatively low local geographic community prevalence (~4.4%) at the time of testing, the hospital's timely procurement of personal protective equipment, rigorous employee education, patient triage, and treatment protocol development and implementation. In addition, cross-reactive adaptive T cell mediated immunity, as recently described, may possibly play a greater role in healthcare workers than in the general population.
One of the most common modalities to examine the human eye is the eye-fundus photograph. The evaluation of fundus photographs is carried out by medical experts during time-consuming visual ...inspection. Our aim is to accelerate this process using computer aided diagnosis. As a first step, it is necessary to segment structures in the images for tissue differentiation. As the eye is the only organ, where the vasculature can be imaged in an in vivo and noninterventional way without using expensive scanners, the vessel tree is one of the most interesting and important structures to analyze. The quality and resolution of fundus images are rapidly increasing. Thus, segmentation methods need to be adapted to the new challenges of high resolutions. In this paper, we present a method to reduce calculation time, achieve high accuracy, and increase sensitivity compared to the original Frangi method. This method contains approaches to avoid potential problems like specular reflexes of thick vessels. The proposed method is evaluated using the STARE and DRIVE databases and we propose a new high resolution fundus database to compare it to the state-of-the-art algorithms. The results show an average accuracy above 94% and low computational needs. This outperforms state-of-the-art methods.
We compare the therapeutic efficacy and toxicity of intravesical bacillus Calmette-Guerin (BCG) with mitomycin C on recurrence of stages Ta and T1 bladder carcinoma.
Combined published and ...unpublished data from comparative studies on BCG versus mitomycin C for superficial bladder carcinoma considering possible confounding factors were analyzed. Odds ratio (OR) and its 95% CI were used as primary effect size estimate. Toxicity data were evaluated descriptively.
In 11 eligible clinical trials 1,421 patients were treated with BCG and 1,328 were treated with mitomycin C. Within the overall median followup time of 26 months 38.6% of the patients in the BCG group and 46.4% of those in the mitomycin C group had tumor recurrence. In 7 of 11 studies BCG was significantly superior to mitomycin C, in 3 studies no significant difference was found, while in 1 study mitomycin C was significantly superior to BCG. An overall statistically significant superiority of BCG versus mitomycin C efficacy in reducing tumor recurrence was detected (OR 0.56, 95% CI 0.38 to 0.84, p = 0.005). In the subgroup treated with BCG maintenance all 6 individual studies showed a significant superiority of BCG over mitomycin C (OR 0.43, 95% CI 0.35 to 0.53, p <0.001). In 4 of the 5 studies with reported data on toxicity BCG associated cystitis was significantly more frequent than in the mitomycin C group (53.8% versus 39.2%). The combined cystitis OR was 1.81 (95% CI 1.48 to 2.23, p <0.001). The OR for cystitis in the BCG maintenance group did not significantly differ from that in the nonmaintenance therapy group.
The results suggest superiority of BCG over mitomycin C for prevention of tumor recurrences in the combined data and particularly in the BCG maintenance treatment subgroup, irrespective of the actual (intermediate or high) tumor risk status. The toxicity with BCG is higher but does not differ between BCG maintenance and nonmaintenance groups.
Babesiosis of cattle Bock, R; Jackson, L; de Vos, A ...
Parasitology,
10/2004, Volume:
129 Suppl
Journal Article
Peer reviewed
Tick fever or cattle fever (babesiosis) is economically the most important arthropod-borne disease of cattle worldwide with vast areas of Australia, Africa, South and Central America and the United ...States continuously under threat. Tick fever was the first disease for which transmission by an arthropod to a mammal was implicated at the turn of the twentieth century and is the first disease to be eradicated from a continent (North America). This review describes the biology of Babesia spp. in the host and the tick, the scale of the problem to the cattle industry, the various components of control programmes, epidemiology, pathogenesis, immunity, vaccination and future research. The emphasis is on Babesia bovis and Babesia bigemina.
To compare the therapeutic efficacy of intravesical bacille Calmette-Guérin (BCG) with mitomycin C (MMC) on progression of Stage Ta and T1 bladder carcinoma.
Combined published and unpublished data ...from comparative studies on BCG versus MMC in superficial bladder carcinoma were analyzed, considering possible confounding factors. Odds ratios (ORs) and 95% confidence intervals (CIs) were used as the primary effect size estimate. Tumor progression was defined as progression to a higher tumor stage or the development of metastatic disease.
In nine eligible clinical trials, 1277 patients were treated with BCG and 1133 with MMC. Within the overall median follow-up of 26 months, 7.67% of the patients in the BCG group and 9.44% of the patients in the MMC group developed tumor progression. In all nine individual studies and in the combined results, no statistically significant difference in the ORs for progression between the BCG and MMC-treated groups was found (combined OR = 0.77; 95% CI 0.57 to 1.03;
P = 0.081). In the subgroup with BCG maintenance, the combined result of the five individual studies showed a statistically significant superiority of BCG over MMC (OR = 0.66; 95% CI 0.47 to 0.94;
P = 0.02). In the four studies without BCG maintenance, the combined result indicated no statistically significant difference between the two treatments (OR = 1.16; 95% CI 0.65 to 2.07;
P = 0.612). Potential confounders, such as tumor risk status, duration of follow-up, BCG strain, BCG and MMC treatment regimen, and year of publication did not significantly influence these results.
The results demonstrated statistically significant superiority for BCG compared with MMC for the prevention of tumor progression only if BCG maintenance therapy was provided.
Although the Bock-Aitkin likelihood-based estimation method for factor analysis of dichotomous item response data has important advantages over classical analysis of item tetrachoric correlations, a ...serious limitation of the method is its reliance on fixed-point Gauss-Hermite (G-H) quadrature in the solution of the likelihood equations and likelihood-ratio tests. When the number of latent dimensions is large, computational considerations require that the number of quadrature points per dimension be few. But with large numbers of items, the dispersion of the likelihood, given the response pattern, becomes so small that the likelihood cannot be accurately evaluated with the sparse fixed points in the latent space. In this paper, we demonstrate that substantial improvement in accuracy can be obtained by adapting the quadrature points to the location and dispersion of the likelihood surfaces corresponding to each distinct pattern in the data. In particular, we show that adaptive G-H quadrature, combined with mean and covariance adjustments at each iteration of an EM algorithm, produces an accurate fast-converging solution with as few as two points per dimension. Evaluations of this method with simulated data are shown to yield accurate recovery of the generating factor loadings for models of upto eight dimensions. Unlike an earlier application of adaptive Gibbs sampling to this problem by Meng and Schilling, the simulations also confirm the validity of the present method in calculating likelihood-ratio chi-square statistics for determining the number of factors required in the model. Finally, we apply the method to a sample of real data from a test of teacher qualifications.
RNA thermometers are thermosensors that regulate gene expression by temperature-induced changes in RNA conformation. Naturally occurring RNA thermometers exhibit complex secondary structures which ...are believed to undergo a series of gradual structural changes in response to temperature shifts. Here, we report the de novo design of considerably simpler RNA thermometers that provide useful RNA-only tools to regulate bacterial gene expression by a shift in the growth temperature. We show that a single small stem-loop structure containing the ribosome binding site is sufficient to construct synthetic RNA thermometers that work efficiently at physiological temperatures. Our data suggest that the thermometers function by a simple melting mechanism and thus provide minimum size on/off switches to experimentally induce or repress gene expression by temperature.
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