675 research outputs found
Combined Bone Marrow and Kidney Transplantation for the Induction of Specific Tolerance
The induction of specific tolerance, in order to avoid the detrimental effects of lifelong systemic immunosuppressive therapy after organ transplantation, has been considered the “Holy Grail” of transplantation. Experimentally, tolerance has been achieved through clonal deletion, through costimulatory blockade, through the induction or infusion of regulatory T-cells, and through the establishment of hematopoietic chimerism following donor bone marrow transplantation. The focus of this review is how tolerance has been achieved following combined bone marrow and kidney transplantation. Preclinical models of combined bone marrow and kidney transplantation have shown that tolerance can be achieved through either transient or sustained hematopoietic chimerism. Combined transplants for patients with multiple myeloma have shown that organ tolerance and prolonged disease remissions can be accomplished with such an approach. Similarly, multiple clinical strategies for achieving tolerance in patients without an underlying malignancy have been described, in the context of either transient or durable mixed chimerism or sustained full donor hematopoiesis. To expand the chimerism approach to deceased donor transplants, a delayed tolerance approach, which will involve organ transplantation with conventional immunosuppression followed months later by bone marrow transplantation, has been successful in a primate model. As combined bone marrow and organ transplantation become safer and increasingly successful, the achievement of specific tolerance may become more widely applicable
Active surveillance for rheumatic heart disease in endemic regions: a systematic review and meta-analysis of prevalence among children and adolescents
Background Rheumatic heart disease accounts for up to 250 000 premature deaths every year worldwide and can be
regarded as a physical manifestation of poverty and social inequality. We aimed to estimate the prevalence of
rheumatic heart disease in endemic countries as assessed by diff erent screening modalities and as a function of age.
Methods We searched Medline, Embase, the Latin American and Caribbean System on Health Sciences Information,
African Journals Online, and the Cochrane Database of Systematic Reviews for population-based studies published
between Jan 1, 1993, and June 30, 2014, that reported on prevalence of rheumatic heart disease among children and
adolescents (≥5 years to <18 years). We assessed prevalence of clinically silent and clinically manifest rheumatic heart
disease in random eff ects meta-analyses according to screening modality and geographical region. We assessed the
association between social inequality and rheumatic heart disease with the Gini coeffi cient. We used Poisson
regression to analyse the eff ect of age on prevalence of rheumatic heart disease and estimated the incidence of
rheumatic heart disease from prevalence data.
Findings We included 37 populations in the systematic review and meta-analysis. The pooled prevalence of
rheumatic heart disease detected by cardiac auscultation was 2·9 per 1000 people (95% CI 1·7–5·0) and by
echocardiography it was 12·9 per 1000 people (8·9–18·6), with substantial heterogeneity between individual reports
for both screening modalities (I²=99·0% and 94·9%, respectively). We noted an association between social
inequality expressed by the Gini coeffi cient and prevalence of rheumatic heart disease (p=0·0002). The prevalence
of clinically silent rheumatic heart disease (21·1 per 1000 people, 95% CI 14·1–31·4) was about seven to eight times
higher than that of clinically manifest disease (2·7 per 1000 people, 1·6–4·4). Prevalence progressively increased
with advancing age, from 4·7 per 1000 people (95% CI 0·0–11·2) at age 5 years to 21·0 per 1000 people (6·8–35·1)
at 16 years. The estimated incidence was 1·6 per 1000 people (0·8–2·3) and remained constant across age categories
(range 2·5, 95% CI 1·3–3·7 in 5-year-old children to 1·7, 0·0–5·1 in 15-year-old adolescents). We noted no sexrelated
diff erences in prevalence (p=0·829).
Interpretation We found a high prevalence of rheumatic heart disease in endemic countries. Although a reduction in
social inequalities represents the cornerstone of community-based prevention, the importance of early detection of
silent rheumatic heart disease remains to be further assessed
Test-retest reliability and effects of repeated testing and satiety on performance of an Emotional Test Battery
The P1vital® Oxford Emotional Test Battery (ETB) comprises five computerized tasks designed to assess cognition and emotional processing in human participants. It has been used in between-subjects experimental designs; however, it is unclear whether the battery can be used in crossover designs. This is of particular importance given the increasing use of ETB tasks for repeated assessment of depressed patients in clinical trials and clinical practice. In addition, although satiety state has been reported to affect performance on some cognitive and emotional tasks, it is not known whether it can influence performance on the ETB. Two studies explored these issues. In Experiment 1, 30 healthy women were tested on the ETB on 4 separate occasions (each a week apart) in a within-subjects design. In Experiment 2, another 30 healthy women were randomized to either a satiated or a hungry condition, where they were given an ad libitum lunch of cheese sandwiches, before (satiated) or after (hungry) they were asked to complete the ETB. Experiment 1 demonstrated good test-retest reliability for the ETB. One of the tasks was free from practice effects, whilst performance on the other four tasks stabilized after the first two sessions. In Experiment 2, eating to satiety only affected performance on a single ETB task. These results suggest that the ETB can be used in crossover designs after two initial training sessions. Further, as a robust satiety manipulation had only a limited effect on a single ETB task, it is unlikely that appetitive state will confound ETB performance
Dose-Reduced Busulfan, Cyclophosphamide, and Autologous Stem Cell Transplantation for Human Immunodeficiency Virus–Associated Lymphoma: AIDS Malignancy Consortium Study 020
AbstractIntensive chemotherapy for human immunodeficiency virus (HIV)-associated non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma (HL) has resulted in durable remissions in a substantial proportion of patients. High-dose chemotherapy and autologous stem cell transplantation (AuSCT), moreover, has resulted in sustained complete remissions in selected patients with recurrent chemosensitive disease. Based on a favorable experience with dose-reduced high-dose busulfan, cyclophosphamide, and AuSCT for older patients with non-HIV–associated aggressive lymphomas, an AIDS Malignancy Consortium multicenter trial was undertaken using the same dose-reduced busulfan and cyclophosphamide preparative regimen with AuSCT for recurrent HIV-associated NHL and HL. Of the 27 patients in the study, 20 received an AuSCT. The median time to achievement of an absolute neutrophil count (ANC) of ≥ 0.5×109/L was 11 days (range, 9-16 days). The median time to achievement of an unsupported platelet count of ≥ 20×109/L was 13 days (range, 6-57 days). One patient died on day +33 posttransplantation from hepatic veno-occlusive disease (VOD) and multiorgan failure. No other fatal regimen-related toxicity occurred. Ten of 19 patients (53%) were in complete remission at the time of their day +100 post-AuSCT evaluation. Of the 20 patients, 10 were alive and event-free at a median of 23 weeks post-AuSCT. Median overall survival (OS) was not reached by 13 of the 20 patients alive at the time of last follow-up. This multi-institutional trial demonstrates that a regimen of dose-reduced high-dose busulfan, cyclophosphamide, and AuSCT is well tolerated and is associated with favorable disease-free survival (DFS) and OS probabilities for selected patients with HIV-associated NHL and HL
Time Variability in Simulated Ultracompact and Hypercompact HII Regions
Ultracompact and hypercompact HII regions appear when a star with a mass
larger than about 15 solar masses starts to ionize its own environment. Recent
observations of time variability in these objects are one of the pieces of
evidence that suggest that at least some of them harbor stars that are still
accreting from an infalling neutral accretion flow that becomes ionized in its
innermost part. We present an analysis of the properties of the HII regions
formed in the 3D radiation-hydrodynamic simulations presented by Peters et al.
as a function of time. Flickering of the HII regions is a natural outcome of
this model. The radio-continuum fluxes of the simulated HII regions, as well as
their flux and size variations are in agreement with the available
observations. From the simulations, we estimate that a small but non-negligible
fraction (~ 10 %) of observed HII regions should have detectable flux
variations (larger than 10 %) on timescales of ~ 10 years, with positive
variations being more likely to happen than negative variations. A novel result
of these simulations is that negative flux changes do happen, in contrast to
the simple expectation of ever growing HII regions. We also explore the
temporal correlations between properties that are directly observed (flux and
size) and other quantities like density and ionization rates.Comment: Monthly Notices of the Royal Astronomical Society, in press. The
movie of free-free optical depth can be found at
http://www.ita.uni-heidelberg.de/~tpeters/tau.av
Rationale, design and conduct of a randomised controlled trial evaluating a primary care-based complex intervention to improve the quality of life of heart failure patients: HICMan (Heidelberg Integrated Case Management) : study protocol
Background: Chronic congestive heart failure (CHF) is a complex disease with rising prevalence, compromised quality of life (QoL), unplanned hospital admissions, high mortality and therefore high burden of illness. The delivery of care for these patients has been criticized and new strategies addressing crucial domains of care have been shown to be effective on patients' health outcomes, although these trials were conducted in secondary care or in highly organised Health Maintenance Organisations. It remains unclear whether a comprehensive primary care-based case management for the treating general practitioner (GP) can improve patients' QoL. Methods/Design: HICMan is a randomised controlled trial with patients as the unit of randomisation. Aim is to evaluate a structured, standardized and comprehensive complex intervention for patients with CHF in a 12-months follow-up trial. Patients from intervention group receive specific patient leaflets and documentation booklets as well as regular monitoring and screening by a prior trained practice nurse, who gives feedback to the GP upon urgency. Monitoring and screening address aspects of disease-specific selfmanagement, (non)pharmacological adherence and psychosomatic and geriatric comorbidity. GPs are invited to provide a tailored structured counselling 4 times during the trial and receive an additional feedback on pharmacotherapy relevant to prognosis (data of baseline documentation). Patients from control group receive usual care by their GPs, who were introduced to guidelineoriented management and a tailored health counselling concept. Main outcome measurement for patients' QoL is the scale physical functioning of the SF-36 health questionnaire in a 12-month follow-up. Secondary outcomes are the disease specific QoL measured by the Kansas City Cardiomyopathy questionnaire (KCCQ), depression and anxiety disorders (PHQ-9, GAD-7), adherence (EHFScBS and SANA), quality of care measured by an adapted version of the Patient Chronic Illness Assessment of Care questionnaire (PACIC) and NTproBNP. In addition, comprehensive clinical data are collected about health status, comorbidity, medication and health care utilisation. Discussion: As the targeted patient group is mostly cared for and treated by GPs, a comprehensive primary care-based guideline implementation including somatic, psychosomatic and organisational aspects of the delivery of care (HICMAn) is a promising intervention applying proven strategies for optimal care. Trial registration: Current Controlled Trials ISRCTN30822978
Diversity and composition of tropical butterflies along an Afromontane agricultural gradient in the Jimma Highlands, Ethiopia
Afromontane landscapes are typically characterized by a mosaic of smallholder farms and the biodiversity impacts of these practices will vary in accordance to local management and landscape context. Here, we assess how tropical butterfly diversity is maintained across an agricultural landscape in the Jimma Highlands of Ethiopia. We used transect surveys to sample understory butterfly communities within degraded natural forest, semi-managed coffee forest (SMCF), exotic timber plantations, open woodland, croplands and pasture. Surveys were conducted in 29 one-hectare plots and repeated five times between January and June 2013. We found that natural forest supports higher butterfly diversity than all agricultural plots (measured with Hill's numbers). SMCF and timber plantations retain relatively high abundance and diversity, but these metrics drop off sharply in open woodland, cropland and pasture. SMCF and timber plantations share the majority of their species with natural forest and support an equivalent abundance of forest-dependent species, with no increase in widespread species. There was some incongruence in the responses of families and sub-families, notably that Lycaenidae are strongly associated with open woodland and pasture. Adult butterflies clearly utilize forested agricultural practices such as SMCF and timber plantations, but species diversity declines steeply with distance from natural forest suggesting that earlier life-stages may depend on host plants and/or microclimatic conditions that are lost under agricultural management. From a management perspective, the protection of natural forest remains a priority for tropical butterfly conservation, but understanding functioning of the wider landscape mosaic is important as SMCF and timber plantations may act as habitat corridors that facilitate movement between forest fragments
GRFS and CRFS in alternative donor hematopoietic cell transplantation for pediatric patients with acute leukemia.
We report graft-versus-host disease (GVHD)-free relapse-free survival (GRFS) (a composite end point of survival without grade III-IV acute GVHD [aGVHD], systemic therapy-requiring chronic GVHD [cGVHD], or relapse) and cGVHD-free relapse-free survival (CRFS) among pediatric patients with acute leukemia (n = 1613) who underwent transplantation with 1 antigen-mismatched (7/8) bone marrow (BM; n = 172) or umbilical cord blood (UCB; n = 1441). Multivariate analysis was performed using Cox proportional hazards models. To account for multiple testing, P \u3c .01 for the donor/graft variable was considered statistically significant. Clinical characteristics were similar between UCB and 7/8 BM recipients, because most had acute lymphoblastic leukemia (62%), 64% received total body irradiation-based conditioning, and 60% received anti-thymocyte globulin or alemtuzumab. Methotrexate-based GVHD prophylaxis was more common with 7/8 BM (79%) than with UCB (15%), in which mycophenolate mofetil was commonly used. The univariate estimates of GRFS and CRFS were 22% (95% confidence interval [CI], 16-29) and 27% (95% CI, 20-34), respectively, with 7/8 BM and 33% (95% CI, 31-36) and 38% (95% CI, 35-40), respectively, with UCB (P \u3c .001). In multivariate analysis, 7/8 BM vs UCB had similar GRFS (hazard ratio [HR], 1.12; 95% CI, 0.87-1.45; P = .39), CRFS (HR, 1.06; 95% CI, 0.82-1.38; P = .66), overall survival (HR, 1.07; 95% CI, 0.80-1.44; P = .66), and relapse (HR, 1.44; 95% CI, 1.03-2.02; P = .03). However, the 7/8 BM group had a significantly higher risk for grade III-IV aGVHD (HR, 1.70; 95% CI, 1.16-2.48; P = .006) compared with the UCB group. UCB and 7/8 BM groups had similar outcomes, as measured by GRFS and CRFS. However, given the higher risk for grade III-IV aGVHD, UCB might be preferred for patients lacking matched donors. © 2019 American Society of Hematology. All rights reserved
The Extended Environment of M17: A Star Formation History
M17 is one of the youngest and most massive nearby star-formation regions in
the Galaxy. It features a bright H II region erupting as a blister from the
side of a giant molecular cloud (GMC). Combining photometry from the Spitzer
GLIMPSE survey with complementary infrared (IR) surveys, we identify candidate
young stellar objects (YSOs) throughout a 1.5 deg x 1 deg field that includes
the M17 complex. The long sightline through the Galaxy behind M17 creates
significant contamination in our YSO sample from unassociated sources with
similar IR colors. Removing contaminants, we produce a highly-reliable catalog
of 96 candidate YSOs with a high probability of association with the M17
complex. We fit model spectral energy distributions to these sources and
constrain their physical properties. Extrapolating the mass function of 62
intermediate-mass YSOs (M >3 Msun), we estimate that >1000 stars are in the
process of forming in the extended outer regions of M17.
From IR survey images from IRAS and GLIMPSE, we find that M17 lies on the rim
of a large shell structure ~0.5 deg in diameter (~20 pc at 2.1 kpc). We present
new maps of CO and 13CO (J=2-1) emission, which show that the shell is a
coherent, kinematic structure associated with M17 at v = 19 km/s. The shell is
an extended bubble outlining the photodissociation region of a faint, diffuse H
II region several Myr old. We provide evidence that massive star formation has
been triggered by the expansion of the bubble. The formation of the massive
cluster ionizing the M17 H II region itself may have been similarly triggered.
We conclude that the star formation history in the extended environment of M17
has been punctuated by successive waves of massive star formation propagating
through a GMC complex.Comment: 31 pages, 15 figures, accepted for publication in ApJ. For a version
with higher-quality figures, see
http://www.astro.wisc.edu/glimpse/Povich2009_M17.pd
Spitzer Space Telescope observations of the Carina Nebula: The steady march of feedback-driven star formation
We report the first results of imaging the Carina Nebula with Spitzer/IRAC,
providing a catalog of point sources and YSOs based on SED fits. We discuss
several aspects of the extended emission, including dust pillars that result
when a clumpy molecular cloud is shredded by massive star feedback. There are
few "extended green objects" (EGOs) normally taken as signposts of outflow
activity, and none of the HH jets detected optically are seen as EGOs. A
population of "extended red objects" tends to be found around OB stars, some
with clear bow-shocks. These are dusty shocks where stellar winds collide with
flows off nearby clouds. Finally, the relative distributions of O stars and
subclusters of YSOs as compared to dust pillars shows that while some YSOs are
located within pillars, many more stars and YSOs reside just outside pillar
heads. We suggest that pillars are transient phenomena, part of a continuous
outwardly propagating wave of star formation driven by massive star feedback.
As pillars are destroyed, they leave newly formed stars in their wake, which
are then subsumed into the young OB association. Altogether, the current
generation of YSOs shows no strong deviation from a normal IMF. The number of
YSOs suggests a roughly constant star-formation rate over the past 3Myr,
implying that star formation in pillars constitutes an important mechanism to
construct unbound OB associations. Accelerated pillars may give birth to O-type
stars that, after several Myr, could appear to have formed in isolation.Comment: 25 pages, 15 figures, MNRAS accepte
- …