Disseminated Mycobacterium avium complex infection in an immunocompetent pregnant woman

BACKGROUND: Disseminated mycobacterium avium complex (MAC) occurs mainly in immunocompromised hosts, which is associated with abnormal cellular immunity. CASE PRESENTATION: A 26-year-old pregnant woman presented with fever and general weakness. Miliary lung nodules were noted on chest X-ray. Under the impression of miliary tuberculosis, anti-tuberculosis medication was administered. However, the patient was not improved. Further work-up demonstrated MAC in the sputum and placenta. The patient was treated successfully with clarithromycin-based combination regimen. CONCLUSION: This appears to be the first case of disseminated MAC in an otherwise healthy pregnant woman. Clinicians should be alert for the diagnosis of MAC infection in diverse clinical conditions

Identifying and analysing protostellar disc fragments in smoothed particle hydrodynamics simulations

We present a new method of identifying protostellar disc fragments in a simulation based on density derivatives, and analyse our data using this and the existing CLUMPFIND method, which is based on an ordered search over all particles in gravitational potential energy. Using smoothed particle hydrodynamics, we carry out 9 simulations of a $0.25$ M$_{\odot}$ disc around a 1 M$_{\odot}$ star, all of which fragment to form at least 2 bound objects. We find that when using all particles ordered in gravitational potential space, only fragments that survive the duration of the simulation are detected. When we use the density derivative method, all fragments are detected, so the two methods are complementary, as using the two methods together allows us to identify all fragments, and to then determine those that are likely to be destroyed. We find a tentative empirical relationship between the dominant azimuthal wavenumber in the disc $m$ and the maximum semi-major axis a fragment may achieve in a simulation, such that $a_{\mathrm{max}}\propto\frac{1}{m}$. We find the fragment destruction rate to be around half that predicted from population synthesis models. This is due to fragment-fragment interactions in the early gas phase of the disc, which can cause scattering and eccentricity pumping on short timescales, and affects the fragment's internal structure. We therefore caution that measurements of eccentricity as a function of semi-major axis may not necessarily constrain the formation mechanism of giant planets and brown dwarfs.Comment: 22 pages, 22 figure

When and how to treat pulmonary non-tuberculous mycobacterial diseases

Nontuberculous mycobacteria are ubiquitous environmental organisms that have been recognised as a cause of pulmonary infection for over 50 years. Traditionally patients have had underlying risk factors for development of disease; however the proportion of apparently immunocompetent patients involved appears to be rising. Not all patients culture-positive for mycobacteria will have progressive disease, making the diagnosis difficult, though criteria to aid in this process are available. The two main forms of disease are cavitary disease (usually involving the upper lobes) and fibronodular bronchiectasis (predominantly middle and lingular lobes). For patients with disease, combination antibiotic therapy for 12-24 months is generally required for successful treatment, and this may be accompanied by drug intolerances and side effects. Published success rates range from 30-82%. As the progression of disease is variable, for some patients, attention to pulmonary hygiene and underlying diseases without immediate antimycobacterial therapy may be more appropriate. Surgery can be a useful adjunct, though is associated with risks. Randomised controlled trials in well described patients would provide stronger evidence-based data to guide therapy of NTM lung diseases, and thus are much needed

Sporadic<i>Salmonella enterica</i>serotype Javiana infections in Georgia and Tennessee: a hypothesis-generating study

SUMMARYFrom 1996 to 2004, the incidence ofSalmonellaJaviana infections increased in FoodNet, the U.S. national active foodborne disease surveillance programme. Contact with amphibians and consumption of tomatoes have been associated with outbreaks ofS. Javiana infection. To generate and test hypotheses about risk factors associated with sporadicS. Javiana infections, we interviewed patients with laboratory-confirmedS. Javiana infection identified in Georgia and Tennessee during August–October 2004. We collected data on food and water consumption, animal contact, and environmental exposure from cases. Responses were compared with population-based survey exposure data. Seventy-two of 117 identifiedS. Javiana case-patients were interviewed. Consumption of well water [adjusted odds ratio (aOR) 4·3, 95% confidence interval (CI) 1·6–11·2] and reptile or amphibian contact (aOR 2·6, 95% CI 0·9–7·1) were associated with infection. Consumption of tomatoes (aOR 0·5, 95% CI 0·3–0·9) and poultry (aOR 0·5, 95% CI 0·2–1·0) were protective. Our study suggests that environmental factors are associated withS. Javiana infections in Georgia and Tennessee.</jats:p

Maximum likelihood estimation in generalized linear models with multiple covariates subject to detection limits

The analysis of data subject to detection limits is becoming increasingly necessary in many environmental and laboratory studies. Covariates subject to detection limits are often left censored because of a measurement device having a minimal lower limit of detection. In this paper, we propose a Monte Carlo version of the expectation–maximization algorithm to handle large number of covariates subject to detection limits in generalized linear models. We model the covariate distribution via a sequence of one-dimensional conditional distributions, and sample the covariate values using an adaptive rejection metropolis algorithm. Parameter estimation is obtained by maximization via the Monte Carlo M-step. This procedure is applied to a real dataset from the National Health and Nutrition Examination Survey, in which values of urinary heavy metals are subject to a limit of detection. Through simulation studies, we show that the proposed approach can lead to a significant reduction in variance for parameter estimates in these models, improving the power of such studies