225 research outputs found
Persistent wheezing as manifestation of esophageal tubular duplication cyst
Duplications of esophagus are rare congenital anomalies and the second most common duplications of the gastrointestinal tract. This form of bronchopulmonary foregut malformation may appear as a cystic mediastinal mass. On chest radiographs they may be visible as middle or posterior masses. On CT they are well marginated and oppose the esophagus. Usually they are asymptomatic, unless they become infected or cause obstruction. We report a case of thoracic tubular duplication cyst in a 10-month-old boy who presented with persistent wheezing that was unsuccessfully treated in out-patient services
HIF2α reduces growth rate but promotes angiogenesis in a mouse model of neuroblastoma
<p>Abstract</p> <p>Background</p> <p>HIF2α/EPAS1 is a hypoxia-inducible transcription factor involved in catecholamine homeostasis, vascular remodelling, physiological angiogenesis and adipogenesis. It is overexpressed in many cancerous tissues, but its exact role in tumour progression remains to be clarified.</p> <p>Methods</p> <p>In order to better establish its function in tumourigenesis and tumour angiogenesis, we have stably transfected mouse neuroblastoma N1E-115 cells with the native form of HIF2α or with its dominant negative mutant, HIF2α (1–485) and studied their phenotype <it>in vitro </it>and <it>in vivo</it>.</p> <p>Results</p> <p><it>In vitro </it>studies reveal that HIF2α induces neuroblastoma cells hypertrophy and decreases their proliferation rate, while its inactivation by the HIF2α (1–485) mutant leads to a reduced cell size, associated with an accelerated proliferation. However, our <it>in vivo </it>experiments show that subcutaneous injection of cells overexpressing HIF2α into syngenic mice, leads to the formation of tumour nodules that grow slower than controls, but that are well structured and highly vascularized. In contrast, HIF2α (1–485)-expressing neuroblastomas grow fast, but are poorly vascularized and quickly tend to extended necrosis.</p> <p>Conclusion</p> <p>Together, our data reveal an unexpected combination between an antiproliferative and a pro-angiogenic function of HIF2α that actually seems to be favourable to the establishment of neuroblastomas <it>in vivo</it>.</p
Systematic review and economic analysis of the comparative effectiveness of different inhaled corticosteroids and their usage with long-acting beta2 agonists for the treatment of chronic asthma in adults and children aged 12 years and over
Meta-AnalysisResearch Support, Non-U.S. Gov'tReviewThis is a freely-available open access publication. Please cite the published version which is available via the DOI link in this recordOBJECTIVES: To assess the clinical and cost-effectiveness of inhaled corticosteroids (ICS) alone and ICS used in combination with a long-acting beta2 agonist (LABA) in the treatment of chronic asthma in adults and children aged over 12 years. DATA SOURCES: Major electronic bibliographic databases, e.g. MEDLINE and EMBASE, were searched up to February/March 2006 (and updated again in October 2006). REVIEW METHODS: A systematic review of clinical and cost-effectiveness studies was conducted. Cost comparison and cost-consequence analyses were performed where appropriate. RESULTS: The assessment of clinical effectiveness was based on the 67 randomised controlled trials selected from the 5175 reports identified through the systematic literature search. The most frequently reported relevant outcomes were lung function, symptoms, use of rescue medication and adverse events. The trials varied considerably. In the trials that compared low-dose ICS versus ICS and high-dose ICS versus ICS, there were few significant differences in clinical effectiveness, although a few of the trials had assessed non-inferiority between the comparators rather than superiority. At doses of 400, 800 and 'high-level' doses of 1500 or 1600 microg/day, beclometasone dipropionate (BDP) appears to be the current cheapest ICS product both with the inclusion and exclusion of chlorofluorocarbon (CFC)-propelled products. A significant treatment benefit for combination ICS/LABA therapy across a range of outcomes compared with ICS alone was identified [when the ICS was double the accepted clinically equivalent dose of the ICS in the combination inhaler, and dry powder inhalers (DPIS) were used to deliver the drugs]. When a formoterol fumarate (FF)/salmeterol (SAL) combination inhaler and a budesonide (BUD)/FF combination inhaler were each compared with their constituent drugs delivered in separate inhalers, there were very few statistically significant differences between the treatments across the various efficacy outcomes and the rate of adverse events. Combination inhalers were more often cheaper than doubling the dose of ICS alone. However, the costs were highly variable and dependent on both the dose required and the preparation used in the trials. The estimated mean annual cost of FP/SAL combination varied from being 94 pounds cheaper to 109 pounds more expensive than the alternative of BUD at a higher dose. The BUD/FF combination varied from being 163 pounds cheaper to 66 pounds more expensive than the higher dose of either BUD or FP. When the combination inhalers were compared to each other, the results were mixed, with the FP/SAL combination significantly superior on some outcomes and the BUD/FF combination superior on others; however, meta-analysis showed that there were no significant differences between the two treatments in the rate of adverse events. Taking an ICS with a LABA as either of the two currently available combination products, FP/SAL and BUD/FF, is usually cheaper than taking the relevant constituent drugs in separate inhalers. At very high doses of BUD (1600 microg/day), however, the BUD/FF combination inhaler can be up to 156 pounds more expensive than having the same drugs in separate inhalers. In terms of the relative costs associated with taking one of the combination inhalers, at low dose (400 microg BUD or 200 microg FP/day) the cheapest combination inhaler is FP/SAL as a pressurised metered dose inhaler (pMDI) (Seretide Evohaler). However, this is only slightly cheaper than using BUD/FF as a DPI (Symbicort Turbohaler). At higher dose levels (800 microg BUD or 500 microg FP/day) FP/SAL as either pMDI aerosol (Seretide Evohaler) or a DPI (Seretide Accuhaler) is the cheapest combination product available, but again only slightly cheaper than the DPI BUD/FF combination (Symbicort Turbohaler). It should be highlighted, however, that the three head-to-head trials that compared the effects of FP/SAL with BUD/FF used the FP/SAL DPI combination inhaler, Seretide Accuhaler. CONCLUSIONS: The evidence indicates that there are few consistent significant differences in effects between the five ICS licensed for use in adults and adolescents over the age of 12 years, at either low or high dose. On average, BDP products currently tend to be the cheapest ICS available and tend to remain so as the daily ICS dose required increases. There is evidence that the addition of a LABA to an ICS is potentially more clinically effective than doubling the dose of ICS alone, although consistent significant differences between the two treatment strategies are not observed for all outcome measures. The cost differences between combination therapy compared with ICS monotherapy are highly variable and dependent on the dose required and the particular preparations used. For the combination therapies of ICS/LABA there are potential cost savings with the use of combination inhalers compared with separate inhalers, with few differences between the two treatment strategies in terms of effects. The only exception to this cost saving is with BUD/FF at doses higher than 1200 microg/day, where separate inhaler devices can become equivalent to or cheaper than combination inhalers. Neither of the two combination inhalers (FP/SAL or BUD/FF) is consistently superior in terms of treatment effect. A comparison of the costs associated with each combination therapy indicates that at low dose FP/SAL delivered via a pMDI is currently the cheapest combination inhaler but only marginally cheaper than BUD/FF delivered as a DPI. At higher doses, both the FP/SAL combination inhalers (PMDI and DPI) are marginally cheaper than BUD/FF (DPI). Future trials of treatment for chronic asthma should standardise the way in which outcome measures are defined and measured, with a greater focus on patient-centred outcomes. For informing future cost-utility and cost-effectiveness analyses from a UK NHS perspective, there is a need for longitudinal studies that comprehensively track the care pathways followed when people experience asthma exacerbations of different severity. Further research synthesis, quantifying the adverse effects of the different ICS, is required for treatment choices by patients and clinicians to be fully informed.HTA Programme, NIC
Intranasal Delivery of E-Selectin Reduces Atherosclerosis in ApoE−/− Mice
Mucosal tolerance to E-selectin prevents stroke and protects against ischemic brain damage in experimental models of stroke studying healthy animals or spontaneously hypertensive stroke-prone rats. A reduction in inflammation and neural damage was associated with immunomodulatory or “tolerogenic” responses to E-selectin. The purpose of the current study on ApoE deficient mice is to assess the capacity of this stroke prevention innovation to influence atherosclerosis, a major underlying cause for ischemic strokes; human E-selectin is being translated as a potential clinical prevention strategy for secondary stroke. Female ApoE−/− mice received intranasal delivery of E-selectin prior to (pre-tolerization) or simultaneously with initiation of a high-fat diet. After 7 weeks on the high-fat diet, lipid lesions in the aorta, serum triglycerides, and total cholesterol were assessed as markers of atherosclerosis development. We also assessed E-selectin-specific antibodies and cytokine responses, in addition to inflammatory responses that included macrophage infiltration of the aorta and altered gene expression profiles of aortic mRNA. Intranasal delivery of E-selectin prior to initiation of high-fat chow decreased atherosclerosis, serum total cholesterol, and expression of the leucocyte chemoattractant CCL21 that is typically upregulated in atherosclerotic lesions of ApoE−/− mice. This response was associated with the induction of E-selectin specific cells producing the immunomodulatory cytokine IL-10 and immunosuppressive antibody isotypes. Intranasal administration of E-selectin generates E-selectin specific immune responses that are immunosuppressive in nature and can ameliorate atherosclerosis, a major risk factor for ischemic stroke. These results provide additional preclinical support for the potential of induction of mucosal tolerance to E-selectin to prevent stroke
Trypanosoma cruzi Gene Expression in Response to Gamma Radiation
Trypanosoma cruzi is an organism highly resistant to ionizing radiation. Following a dose of 500 Gy of gamma radiation, the fragmented genomic DNA is gradually reconstructed and the pattern of chromosomal bands is restored in less than 48 hours. Cell growth arrests after irradiation but, while DNA is completely fragmented, RNA maintains its integrity. In this work we compared the transcriptional profiles of irradiated and non-irradiated epimastigotes at different time points after irradiation using microarray. In total, 273 genes were differentially expressed; from these, 160 were up-regulated and 113 down-regulated. We found that genes with predicted functions are the most prevalent in the down-regulated gene category. Translation and protein metabolic processes, as well as generation of precursor of metabolites and energy pathways were affected. In contrast, the up-regulated category was mainly composed of obsolete sequences (which included some genes of the kinetoplast DNA), genes coding for hypothetical proteins, and Retrotransposon Hot Spot genes. Finally, the tyrosyl-DNA phosphodiesterase 1, a gene involved in double-strand DNA break repair process, was up-regulated. Our study demonstrated the peculiar response to ionizing radiation, raising questions about how this organism changes its gene expression to manage such a harmful stress
Accumulation of intraneuronal Aβ correlates with ApoE4 genotype
In contrast to extracellular plaque and intracellular tangle pathology, the presence and relevance of intraneuronal Aβ in Alzheimer’s disease (AD) is still a matter of debate. Human brain tissue offers technical challenges such as post-mortem delay and uneven or prolonged tissue fixation that might affect immunohistochemical staining. In addition, previous studies on intracellular Aβ accumulation in human brain often used antibodies targeting the C-terminus of Aβ and differed strongly in the pretreatments used. To overcome these inconsistencies, we performed extensive parametrical testing using a highly specific N-terminal Aβ antibody detecting the aspartate at position 1, before developing an optimal staining protocol for intraneuronal Aβ detection in paraffin-embedded sections from AD patients. To rule out that this antibody also detects the β-cleaved APP C-terminal fragment (β-CTF, C99) bearing the same epitope, paraffin-sections of transgenic mice overexpressing the C99-fragment were stained without any evidence for cross-reactivity in our staining protocol. The staining intensity of intraneuronal Aβ in cortex and hippocampal tissue of 10 controls and 20 sporadic AD cases was then correlated to patient data including sex, Braak stage, plaque load, and apolipoprotein E (ApoE) genotype. In particular, the presence of one or two ApoE4 alleles strongly correlated with an increased accumulation of intraneuronal Aβ peptides. Given that ApoE4 is a major genetic risk factor for AD and is involved in neuronal cholesterol transport, it is tempting to speculate that perturbed intracellular trafficking is involved in the increased intraneuronal Aβ aggregation in AD
Toll-Like Receptor-2 Mediates Diet and/or Pathogen Associated Atherosclerosis: Proteomic Findings
BACKGROUND. Accumulating evidence implicates a fundamental link between the immune system and atherosclerosis. Toll-like receptors are principal sensors of the innate immune system. Here we report an assessment of the role of the TLR2 pathway in atherosclerosis associated with a high-fat diet and/or bacteria in ApoE+/- mice. METHODS AND RESULTS. To explore the role of TLR2 in inflammation- and infection-associated atherosclerosis, 10 week-old ApoE+/--TLR2+/+, ApoE+/--TLR2+/- and ApoE+/--TLR2-/- mice were fed either a high fat diet or a regular chow diet. All mice were inoculated intravenously, once per week for 24 consecutive weeks, with 50 μl live Porphyromonas gingivalis (P.g) (107 CFU) or vehicle (normal saline). Animals were euthanized 24 weeks after the first inoculation. ApoE+/--TLR2+/+ mice showed a significant increase in atheromatous lesions in proximal aorta and aortic tree compared to ApoE+/--TLR2+/- and ApoE+/--TLR2-/- mice for all diet conditions. They also displayed profound changes in plaque composition, as evidenced by increased macrophage infiltration and apoptosis, increased lipid content, and decreased smooth muscle cell mass, all reflecting an unstable plaque phenotype. SAA levels from ApoE+/--TLR2+/+ mice were significantly higher than from ApoE+/--TLR2+/- and ApoE+/--TLR2-/- mice. Serum cytokine analysis revealed increased levels of pro-inflammatory cytokines in ApoE+/--TLR2+/+ mice compared to ApoE+/--TLR2+/- and TLR2-/- mice, irrespective of diet or bacterial challenge. ApoE+/--TLR2+/+ mice injected weekly for 24 weeks with FSL-1 (a TLR2 agonist) also demonstrated significant increases in atherosclerotic lesions, SAA and serum cytokine levels compared to ApoE+/--TLR2-/- mice under same treatment condition. Finally, mass-spectrometry (MALDI-TOF-MS) of aortic samples analyzed by 2-dimentional gel electrophoresis differential display, identified 6 proteins upregulated greater than 2-fold in ApoE+/--TLR2+/+ mice fed the high fat diet and inoculated with P.g compared to any other group. CONCLUSION. Genetic deficiency of TLR2 reduces diet- and/or pathogen-associated atherosclerosis in ApoE+/- mice, along with differences in plaque composition suggesting greater structural stability while TLR-2 ligand-specific activation triggers atherosclerosis. The present data offers new insights into the pathophysiological pathways involved in atherosclerosis and paves the way for new pharmacological interventions aimed at reducing atherosclerosis.National Heart, Lung, and Blood Institute (R01 HL076801
Inflammation Triggers Emergency Granulopoiesis through a Density-Dependent Feedback Mechanism
Normally, neutrophil pools are maintained by homeostatic mechanisms that require
the transcription factor C/EBPα. Inflammation, however, induces neutrophilia
through a distinct pathway of “emergency” granulopoiesis that is
dependent on C/EBPβ. Here, we show in mice that alum triggers emergency
granulopoiesis through the IL-1RI-dependent induction of G-CSF. G-CSF/G-CSF-R
neutralization impairs proliferative responses of hematopoietic stem and
progenitor cells (HSPC) to alum, but also abrogates the acute mobilization of BM
neutrophils, raising the possibility that HSPC responses to inflammation are an
indirect result of the exhaustion of BM neutrophil stores. The induction of
neutropenia, via depletion with Gr-1 mAb or myeloid-specific ablation of Mcl-1,
elicits G-CSF via an IL-1RI-independent pathway, stimulating granulopoietic
responses indistinguishable from those induced by adjuvant. Notably, C/EBPβ,
thought to be necessary for enhanced generative capacity of BM, is dispensable
for increased proliferation of HSPC to alum or neutropenia, but plays a role in
terminal neutrophil differentiation during granulopoietic recovery. We conclude
that alum elicits a transient increase in G-CSF production via IL-1RI for the
mobilization of BM neutrophils, but density-dependent feedback sustains G-CSF
for accelerated granulopoiesis
- …