The advection of thermonuclear ashes by magnetized domains emerging near the H shell was suggested to explain asymptotic giant branch (AGB) star abundances. Here we verify this idea quantitatively ...through exact MHD models. Starting with a simple two-dimensional (2D) geometry and in an inertia frame, we study plasma equilibria avoiding the complications of numerical simulations. We show that below the convective envelope of an AGB star, variable magnetic fields induce a natural expansion, permitted by the almost ideal MHD conditions, in which the radial velocity grows as the second power of the radius. We then study the convective envelope, where the complexity of macroturbulence allows only for a schematic analytical treatment. Here the radial velocity depends on the square root of the radius. We then verify the robustness of our results with 3D calculations for the velocity, showing that for both studied regions the solution previously found can be seen as a planar section of a more complex behavior, in which the average radial velocity retains the same dependency on the radius found in 2D. As a final check, we compare our results to approximate descriptions of buoyant magnetic structures. For realistic boundary conditions, the envelope crossing times are sufficient to disperse in the huge convective zone any material transported, suggesting magnetic advection as a promising mechanism for deep mixing. The mixing velocities are smaller than for convection but larger than for diffusion and adequate for extra mixing in red giants.
Neutropenic patients developing acute disseminated candidiasis may present with skin lesions.
To evaluate the epidemiology of acute disseminated candidiasis with skin lesions in neutropenic patients, ...taking into consideration changes caused by different prophylactic strategies.
A systematic review of English-language articles found via PubMed (1963–2016) was performed. We asked the following questions: (a) What Candida species are more frequently involved in this syndrome? (b) Has antifungal prophylaxis changed the species causing skin lesions? (c) What are the typical patterns of skin lesions? (d) What is the frequency of skin lesions in neutropenic patients with candidaemia or acute disseminated candidiasis? (e) Has antifungal prophylaxis decreased the incidence of acute disseminated candidiasis with skin lesions?
Among 183 studies, 33 were selected, reporting 100 cases of acute disseminated candidiasis with skin lesions in neutropenic patients. It occurred more frequently in the setting of induction therapy for de novo or relapsed acute leukaemia, and the most frequent Candida species were C. tropicalis (68%) and C. krusei (15%). Diffuse maculopapular lesions predominated in cases caused by C. tropicalis and nodular and papular lesions in cases caused by C. krusei. Prophylaxis with fluconazole was reported in six cases, C. krusei in five and C. ciferrii in one. The death rate was 45.4%.
Two patterns were recognized: disseminated maculopapular lesions caused by C. tropicalis in patients not receiving fluconazole prophylaxis, occurring in 39% to 44% of neutropenic patients with acute disseminated candidiasis, and nodular lesions caused by C. krusei in patients receiving fluconazole prophylaxis, occurring less frequently.
To investigate azole resistance in clinical Aspergillus isolates, we conducted prospective multicenter international surveillance. A total of 3,788 Aspergillus isolates were screened in 22 centers ...from 19 countries. Azole-resistant A. fumigatus was more frequently found (3.2% prevalence) than previously acknowledged, causing resistant invasive and noninvasive aspergillosis and severely compromising clinical use of azoles.
To compare the epidemiology, clinical presentation, diagnosis, treatment, and outcome of haematologic patients with invasive aspergillosis (IA) or invasive fusariosis (IF).
We retrospectively ...reviewed the charts of 36 patients with IA and 26 with IF diagnosed between 2006 and 2017 in haematologic patients, and compared baseline characteristics, coexisting exposures, clinical manifestations, treatment, and the outcome.
Fever was more frequent in IF (96.2% vs. 63.9%, p 0.003), whereas pneumonia (88.9% vs. 50.0%, p 0.001) and sinusitis (63.9% vs. 38.5%, p 0.048) were more frequent in IA. Skin lesions and positive blood cultures occurred exclusively in patients with IF. Among patients with pneumonia, the halo sign was more frequent in IA (62.5% vs. 23.1%, p 0.02). Serum galactomannan was positive in 88.6% of patients with IA and in 73.3% with IF (p 0.18), with no differences in the median number of positive tests and galactomannan values. Positive serum galactomannan plus lung infiltrates was the predominant clinical presentation in IA and occurred in four of 13 patients with IF and lung involvement. The 30-day survival was 77.7% in IA and 46.1% in IF (p 0.01).
IA and IF share the same epidemiologic scenario but different clinical presentations in the majority of cases, with disease in the airways in IA, and fever, metastatic skin lesions, and positive blood cultures in IF. However, a substantial proportion of patients with IF present with a clinical picture similar to IA, with fever, lung infiltrates, and positive serum galactomannan.
Background. Invasive candidiasis is an important cause of morbidity and mortality among patients with health care–associated infection. The echinocandins have potent fungicidal activity against most ...Candida species, but there are few data comparing the safety and efficacy of echinocandins in the treatment of invasive candidiasis. Methods. This was an international, randomized, double-blind trial comparing micafungin (100 mg daily) and micafungin (150 mg daily) with a standard dosage of caspofungin (70 mg followed by 50 mg daily) in adults with candidemia and other forms of invasive candidiasis. The primary end point was treatment success, defined as clinical and mycological success at the end of blinded intravenous therapy. Results. A total of 595 patients were randomized to one the treatment groups and received at least 1 dose of study drug. In the modified intent-to-treat population, 191 patients were assigned to the micafungin 100 mg group, 199 to the micafungin 150 mg group, and 188 to the caspofungin group. Demographic characteristics and underlying disorders were comparable across the groups. Approximately 85% of patients had candidemia; the remainder had noncandidemic invasive candidiasis. At the end of blinded intravenous therapy, treatment was considered successful for 76.4% of patients in the micafungin 100 mg group, 71.4% in the micafungin 150 mg group, and 72.3% in the caspofungin group. The median time to culture negativity was 2 days in the micafungin 100 mg group and the caspofungin group, compared with 3 days in the micafungin 150 mg groups. There were no significant differences in mortality, relapsing and emergent infections, or adverse events between the study arms. Conclusions. Dosages of micafungin 100 mg daily and 150 mg daily were noninferior to a standard dosage of caspofungin for the treatment of candidemia and other forms of invasive candidiasis.
The epidemiology of invasive fungal infection is evolving. Yeasts other than Candida albicans and molds other than Aspergillus fumigatus have emerged as significant causes of invasive mycoses in ...severely immunocompromised patients. Although, in some instances, these changes may be related to medical interventions, such as the use of antifungal agents in prophylaxis, in the majority of cases, they seem to be a consequence of changes in the host, such as more-severe immunosuppression or different types of immunosuppression impacting both risk periods and the infections that occur. These factors have altered the epidemiology of infection in organ transplant recipients, premature newborns, and critically ill patients. This review discusses the epidemiology of some fungal infections that have emerged in the past few years, with an emphasis on the potential factors associated with their emergence and on practical implications of these epidemiological changes.
Invasive fusariosis (IF) has been associated with a poor prognosis. Although recent series have reported improved outcomes, the definition of optimal treatments remains controversial. The objective ...of this study was to evaluate changes in the outcome of IF. We retrospectively analysed 233 cases of IF from 11 countries, comparing demographics, clinical findings, treatment and outcome in two periods: 1985–2000 (period 1) and 2001–2011 (period 2). Most patients (92%) had haematological disease. Primary treatment with deoxycholate amphotericin B was more frequent in period 1 (63% vs. 30%, p <0.001), whereas voriconazole (32% vs. 2%, p <0.001) and combination therapies (18% vs. 1%, p <0.001) were more frequent in period 2. The 90-day probabilities of survival in periods 1 and 2 were 22% and 43%, respectively (p <0.001). In period 2, the 90-day probabilities of survival were 60% with voriconazole, 53% with a lipid formulation of amphotericin B, and 28% with deoxycholate amphotericin B (p 0.04). Variables associated with poor prognosis (death 90 days after the diagnosis of fusariosis) by multivariable analysis were: receipt of corticosteroids (hazard ratio (HR) 2.11, 95% CI 1.18–3.76, p 0.01), neutropenia at end of treatment (HR 2.70, 95% CI 1.57–4.65, p <0.001), and receipt of deoxycholate amphotericin B (HR 1.83, 95% CI 1.06–3.16, p 0.03). Treatment practices have changed over the last decade, with an increased use of voriconazole and combination therapies. There has been a 21% increase in survival rate in the last decade.
Aims/hypothesis
Our aim was to study the association between serum 25-hydroxyvitamin D (25OHD) concentration and islet autoimmunity and type 1 diabetes in children with an increased genetic risk of ...type 1 diabetes.
Methods
Serum samples for 25OHD measurements were obtained in the Trial to Reduce IDDM in the Genetically at Risk (TRIGR) ancillary study (Divia) from children in 15 countries. Case children (
n
= 244) were defined as having positivity for at least two out of four diabetes-associated autoantibodies measured at any one sample. For each case child, two control children were selected matched for country and date of birth (±1 year) (
n
= 488). Of the case children, 144 developed type 1 diabetes. Serum 25OHD was measured repeatedly in infancy and childhood and was compared according to age at the first seroconversion (at 6, 12 and 18 months prior to and at seroconversion) and calendar age (0, 6, 12 and 18 months).
Results
In children with islet autoimmunity, mean serum 25OHD concentration was lower 18 months prior to the age of first seroconversion of the case children compared with the control children (57.7 vs 64.8 nmol/l,
p
= 0.007). In children with type 1 diabetes (
n
= 144), mean serum 25OHD concentration was lower 18 months prior to the age of the first seroconversion (58.0 vs 65.0 nmol/l,
p
= 0.018) and at the calendar age of 12 months (70.1 vs 75.9 nmol/l,
p
= 0.031) than in their control counterparts. Analyses were adjusted for month of sample collection, human leucocyte antigen genotype, maternal type 1 diabetes and sex.
Conclusions/interpretation
The results suggest that early postnatal vitamin D may confer protection against the development of type 1 diabetes.
Trial registration
ClinicalTrials.gov
NCT00179777
PDF
