3,370 research outputs found
\ud Case Report: Unsuspected Uterine Choriocarcinoma with Lung Metastasis\ud
Choriocarcinoma is a rare form of cancer which commonly occurs in women of reproductive age, rarely in post-menopausal women and in women under 20 years of age. Methods & Results: We report an unsuspected case of uterine choriocarcinoma with lung metastasis in a 27 year-old woman who presented to a medical ward with a history of prominent respiratory, but also genital and gastrointestinal symptoms. Conclusions: The presented case report emphasizes the need for sophisticated diagnostic technology to enable early diagnosis and correct treatment. Furthermore the case highlights the need for healthcare workers to consider rare causes of respiratory signs and symptoms
Prevalence of tuberculosis in post-mortem studies of HIV-infected adults and children in resource-limited settings: a systematic review and meta-analysis.
OBJECTIVES: Tuberculosis (TB) is estimated to be the leading cause of HIV-related deaths globally. However, since HIV-associated TB frequently remains unascertained, we systematically reviewed autopsy studies to determine the true burden of TB at death. METHODS: We systematically searched Medline and Embase databases (to end 2013) for literature reporting on health facility-based autopsy studies of HIV-infected adults and/or children in resource-limited settings. Using forest plots and random-effects meta-analysis, we summarized the TB prevalence found at autopsy and used meta-regression to explore variables associated with autopsy TB prevalence. RESULTS: We included 36 eligible studies, reporting on 3237 autopsies. Autopsy TB prevalence was extremely heterogeneous (range 0-64.4%), but was markedly higher in adults [pooled prevalence 39.7%, 95% confidence interval (CI) 32.4-47.0%] compared to children (pooled prevalence 4.5%, 95% CI 1.7-7.4%). Post-mortem TB prevalence varied by world region, with pooled estimates in adults of 63.2% (95% CI 57.7-68.7%) in South Asia (n = 2 studies); 43.2% (95% CI 38.0-48.3) in sub-Saharan Africa (n = 9 studies); and 27.1% (95% CI 16.0-38.1%) in the Americas (n = 5 studies). Autopsy prevalence positively correlated with contemporary estimates of national TB prevalence. TB in adults was disseminated in 87.9% (82.2-93.7%) of cases and was considered the cause of death in 91.4% (95% CI 85.8-97.0%) of TB cases. Overall, TB was the cause of death in 37.2% (95% CI 25.7-48.7%) of adult HIV/AIDS-related deaths. TB remained undiagnosed at death in 45.8% (95% CI 32.6-59.1%) of TB cases. CONCLUSIONS: In resource-limited settings, TB accounts for approximately 40% of facility-based HIV/AIDS-related adult deaths. Almost half of this disease remains undiagnosed at the time of death. These findings highlight the critical need to improve the prevention, diagnosis and treatment of HIV-associated TB globally
An Experimental Investigation of the Scaling of Columnar Joints
Columnar jointing is a fracture pattern common in igneous rocks in which
cracks self-organize into a roughly hexagonal arrangement, leaving behind an
ordered colonnade. We report observations of columnar jointing in a laboratory
analog system, desiccated corn starch slurries. Using measurements of moisture
density, evaporation rates, and fracture advance rates as evidence, we suggest
an advective-diffusive system is responsible for the rough scaling behavior of
columnar joints. This theory explains the order of magnitude difference in
scales between jointing in lavas and in starches. We investigated the scaling
of average columnar cross-sectional areas due to the evaporation rate, the
analog of the cooling rate of igneous columnar joints. We measured column areas
in experiments where the evaporation rate depended on lamp height and time, in
experiments where the evaporation rate was fixed using feedback methods, and in
experiments where gelatin was added to vary the rheology of the starch. Our
results suggest that the column area at a particular depth is related to both
the current conditions, and hysteretically to the geometry of the pattern at
previous depths. We argue that there exists a range of stable column scales
allowed for any particular evaporation rate.Comment: 12 pages, 11 figures, for supporting online movies, go to
http://www.physics.utoronto.ca/nonlinear/movies/starch_movies.htm
A case of recurrent epilepsy-associated rosette-forming glioneuronal tumor with anaplastic transformation in the absence of therapy.
Rosette-forming glioneuronal tumor (RGNT) most commonly occurs adjacent to the fourth ventricle and therefore rarely presents with epilepsy. Recent reports describe RGNT occurrence in other anatomical locations with considerable morphologic and genetic overlap with the epilepsy-associated dysembryoplastic neuroepithelial tumor (DNET). Examples of RGNT or DNET with anaplastic change are rare, and typically occur in the setting of radiation treatment. We present the case of a 5-year-old girl with seizures, who underwent near total resection of a cystic temporal lobe lesion. Pathology showed morphologic and immunohistochemical features of RGNT, albeit with focally overlapping DNET-like patterns. Resections of residual or recurrent tumor were performed 1 year and 5 years after the initial resection, but no adjuvant radiation or chemotherapy was given. Ten years after the initial resection, surveillance imaging identified new and enhancing nodules, leading to another gross total resection. This specimen showed areas similar to the original tumor, but also high-grade foci with oligodendroglial morphology, increased cellularity, palisading necrosis, microvascular proliferation, and up to 13 mitotic figures per 10 high power fields. Ancillary studies the status by sequencing showed wild-type of the isocitrate dehydrogenase 1 (IDH1), IDH2, and human histone 3.3 (H3F3A) genes, and BRAF studies were negative for mutation or rearrangement. Fluorescence in situ hybridization (FISH) showed codeletion of 1p and 19q limited to the high-grade regions. By immunohistochemistry there was loss of nuclear alpha-thalassemia mental retardation syndrome, X-linked (ATRX) expression only in the high-grade region. Next-generation sequencing showed an fibroblast growth factor receptor receptor 1 (FGFR1) kinase domain internal tandem duplication in three resection specimens. ATRX mutation in the high-grade tumor was confirmed by sequencing which showed a frameshift mutation (p.R1427fs), while the apparent 1p/19q-codeletion by FISH was due to loss of chromosome arm 1p and only partial loss of 19q. Exceptional features of this case include the temporal lobe location, 1p/19q loss by FISH without true whole-arm codeletion, and anaplastic transformation associated with ATRX mutation without radiation or chemotherapy
Deep Convolutional Autoencoders as Generic Feature Extractors in Seismological Applications
The idea of using a deep autoencoder to encode seismic waveform features and
then use them in different seismological applications is appealing. In this
paper, we designed tests to evaluate this idea of using autoencoders as feature
extractors for different seismological applications, such as event
discrimination (i.e., earthquake vs. noise waveforms, earthquake vs. explosion
waveforms, and phase picking). These tests involve training an autoencoder,
either undercomplete or overcomplete, on a large amount of earthquake
waveforms, and then using the trained encoder as a feature extractor with
subsequent application layers (either a fully connected layer, or a
convolutional layer plus a fully connected layer) to make the decision. By
comparing the performance of these newly designed models against the baseline
models trained from scratch, we conclude that the autoencoder feature extractor
approach may only perform well under certain conditions such as when the target
problems require features to be similar to the autoencoder encoded features,
when a relatively small amount of training data is available, and when certain
model structures and training strategies are utilized. The model structure that
works best in all these tests is an overcomplete autoencoder with a
convolutional layer and a fully connected layer to make the estimation
Trajectories in muscular strength and physical function among men with and without prostate cancer in the health aging and body composition study
Objectives
To examine and compare changes in strength and physical function from pre- to post-diagnosis among men with prostate cancer (PC, [cases]) and matched non-cancer controls identified from the Health, Aging and Body Composition (Health ABC) study.
Materials and methods
We conducted a longitudinal analysis of 2 strength and 3 physical function-based measures among both cases and controls, identified from a large cohort of community living older adults enrolled in the Health ABC study. We plotted trajectories for each measure and compared cases vs. controls from the point of diagnosis onwards using mixed-effects regression models. For cases only, we examined predictors of poor strength or physical function.
Results
We identified 117 PC cases and 453 matched non-cancer controls (50% African Americans). At baseline, there were no differences between cases and controls in demographic factors, comorbidities or self-reported physical function; however, cases had slightly better grip strength (44.6 kg vs. 41.0 kg, p\u3c0.01), quadriceps strength (360.5 Nm vs. 338.7 Nm, p = 0.02) and Health ABC physical performance battery scores (2.4 vs. 2.3, p = 0.01). All men experienced similar declines in strength and physical function over an equivalent amount of time. The loss of quad strength was most notable, with losses of nearly two-thirds of baseline strength over approximately 7 years of follow up.
Conclusions
Among both cases and controls, strength and physical function decline with increasing age. The largest declines were seen in lower body strength. Regular assessments should guide lifestyle interventions that can offset age- and treatment-related declines among men with PC
Inhibition of cyclin-dependent kinase 9 downregulates cytokine production without detrimentally affecting human monocyte-derived macrophage viability
Cyclin-dependent kinase (CDK) inhibitor drugs (CDKi), such as R-roscovitine and AT7519, induce neutrophil apoptosis in vitro and enhance the resolution of inflammation in a number of in vivo models. This class of compounds are potential novel therapeutic agents that could promote the resolution of acute and chronic inflammatory conditions where neutrophil activation contributes to tissue damage and aberrant tissue repair. In this study we investigated CDKi effects on macrophage pro-inflammatory mediator production and viability. Treatment of human monocyte-derived macrophages (MDMs) with the CDKi AT7519 and R-roscovitine at concentrations that induce neutrophil apoptosis had no significant effect on control or LPS-activated MDM apoptosis and viability, and did not detrimentally affect MDM efferocytosis of apoptotic cells. In addition, enhanced efferocytosis, induced by the glucocorticoid dexamethasone, was also unaffected after a short time treatment with R-roscovitine. Macrophage cytokine responses to inflammatory stimuli are also of importance during inflammation and resolution. As a key target of CDKi, CDK9, is involved in protein transcription via the RNA polymerase II complex, we investigated the effect of CDKi drugs on cytokine production. Our data show that treatment with AT7519 significantly downregulated expression and release of key MDM cytokines IL-6, TNF, IL-10 and IL-1β, as well as markers of pro-inflammatory macrophage polarisation. R-Roscovitine was also able to downregulate inflammatory cytokine protein secretion from MDMs. Using siRNA transfection, we demonstrate that genetic knock-down of CDK9 replicates these findings, reducing expression and release of pro-inflammatory cytokines. Furthermore, overexpression of CDK9 in THP-1 cells can promote a pro-inflammatory phenotype in these cells, suggesting that CDK9 plays an important role in the inflammatory phenotype of macrophages. Overall, this study demonstrates that pharmacological and genetic targeting of CDK9 inhibits an inflammatory phenotype in human MDMs. As such these data indicate that CDK9 may be key to therapeutically targeting pro-inflammatory macrophage functions during chronic inflammation
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