225 research outputs found
Proton beam therapy
Conventional radiation therapy directs photons (X-rays) and electrons at tumours with the intent of eradicating the neoplastic tissue while preserving adjacent normal tissue. Radiation-induced damage to healthy tissue and second malignancies are always a concern, however, when administering radiation. Proton beam radiotherapy, one form of charged particle therapy, allows for excellent dose distributions, with the added benefit of no exit dose. These characteristics make this form of radiotherapy an excellent choice for the treatment of tumours located next to critical structures such as the spinal cord, eyes, and brain, as well as for paediatric malignancies
Proton and carbon ion radiotherapy for primary brain tumors delivered with active raster scanning at the Heidelberg Ion Therapy Center (HIT): early treatment results and study concepts
<p>Abstract</p> <p>Background</p> <p>Particle irradiation was established at the University of Heidelberg 2 years ago. To date, more than 400 patients have been treated including patients with primary brain tumors. In malignant glioma (WHO IV) patients, two clinical trials have been set up-one investigating the benefit of a carbon ion (18 GyE) vs. a proton boost (10 GyE) in addition to photon radiotherapy (50 Gy), the other one investigating reirradiation with escalating total dose schedules starting at 30 GyE. In atypical meningioma patients (WHO °II), a carbon ion boost of 18 GyE is applied to macroscopic tumor residues following previous photon irradiation with 50 Gy.</p> <p>This study was set up in order to investigate toxicity and response after proton and carbon ion therapy for gliomas and meningiomas.</p> <p>Methods</p> <p>33 patients with gliomas (n = 26) and meningiomas (n = 7) were treated with carbon ion (n = 26) and proton (n = 7) radiotherapy. In 22 patients, particle irradiation was combined with photon therapy. Temozolomide-based chemotherapy was combined with particle therapy in 17 patients with gliomas. Particle therapy as reirradiation was conducted in 7 patients. Target volume definition was based upon CT, MRI and PET imaging. Response was assessed by MRI examinations, and progression was diagnosed according to the Macdonald criteria. Toxicity was classified according to CTCAE v4.0.</p> <p>Results</p> <p>Treatment was completed and tolerated well in all patients. Toxicity was moderate and included fatigue (24.2%), intermittent cranial nerve symptoms (6%) and single episodes of seizures (6%). At first and second follow-up examinations, mean maximum tumor diameters had slightly decreased from 29.7 mm to 27.1 mm and 24.9 mm respectively. Nine glioma patients suffered from tumor relapse, among these 5 with infield relapses, causing death in 8 patients. There was no progression in any meningioma patient.</p> <p>Conclusions</p> <p>Particle radiotherapy is safe and feasible in patients with primary brain tumors. It is associated with little toxicity. A positive response of both gliomas and meningiomas, which is suggested in these preliminary data, must be evaluated in further clinical trials.</p
Analytic philosophy for biomedical research: the imperative of applying yesterday's timeless messages to today's impasses
The mantra that "the best way to predict the future is to invent it" (attributed to the computer scientist Alan Kay) exemplifies some of the expectations from the technical and innovative sides of biomedical research at present. However, for technical advancements to make real impacts both on patient health and genuine scientific understanding, quite a number of lingering challenges facing the entire spectrum from protein biology all the way to randomized controlled trials should start to be overcome. The proposal in this chapter is that philosophy is essential in this process. By reviewing select examples from the history of science and philosophy, disciplines which were indistinguishable until the mid-nineteenth century, I argue that progress toward the many impasses in biomedicine can be achieved by emphasizing theoretical work (in the true sense of the word 'theory') as a vital foundation for experimental biology. Furthermore, a philosophical biology program that could provide a framework for theoretical investigations is outlined
Long Lasting Local and Systemic Inflammation after Cerebral Hypoxic ischemia in Newborn Mice
Background: Hypoxic ischemia (HI) is an important cause of neonatal brain injury and subsequent inflammation affects neurological outcome. In this study we performed investigations of systemic and local activation states of inflammatory cells from innate and adaptive immunity at different time points after neonatal HI brain injury in mice. Methodology/Principal Findings: We developed a multiplex flow cytometry based method combined with immunohistochemistry to investigate cellular immune responses in the brain 24 h to 7 months after HI brain injury. In addition, functional studies of ex vivo splenocytes after cerebral hypoxic ischemia were performed. Both central and peripheral activation of CD11b + and CD11c + antigen presenting cells were seen with expression of the costimulatory molecule CD86 and MHC-II, indicating active antigen presentation in the damaged hemisphere and in the spleen. After one week, naïve CD45rb + T-lymphocytes were demonstrated in the damaged brain hemisphere. In a second phase after three months, pronounced activation of CD45rb 2 T-lymphocytes expressing CD69 and CD25 was seen in the damaged hemisphere. Brain homogenate induced proliferation in splenocytes after HI but not in controls. Conclusions/Significance: Our findings demonstrate activation of both local and systemic immune responses months after hypoxic ischemic neonatal brain injury. The long term immune activation observed is of general importance for future studies of the inflammatory response after brain injury as most previous studies have focused on the first few weeks afte
Genomic resolution of linkages in carbon, nitrogen, and sulfur cycling among widespread estuary sediment bacteria
Abstract
Background
Estuaries are among the most productive habitats on the planet. Bacteria in estuary sediments control the turnover of organic carbon and the cycling of nitrogen and sulfur. These communities are complex and primarily made up of uncultured lineages, thus little is known about how ecological and metabolic processes are partitioned in sediments.
Results
De novo assembly and binning resulted in the reconstruction of 82 bacterial genomes from different redox regimes of estuary sediments. These genomes belong to 23 bacterial groups, including uncultured candidate phyla (for example, KSB1, TA06, and KD3-62) and three newly described phyla (White Oak River (WOR)-1, WOR-2, and WOR-3). The uncultured phyla are generally most abundant in the sulfate-methane transition (SMTZ) and methane-rich zones, and genomic data predict that they mediate essential biogeochemical processes of the estuarine environment, including organic carbon degradation and fermentation. Among the most abundant organisms in the sulfate-rich layer are novel Gammaproteobacteria that have genes for the oxidation of sulfur and the reduction of nitrate and nitrite. Interestingly, the terminal steps of denitrification (NO3 to N2O and then N2O to N2) are present in distinct bacterial populations.
Conclusions
This dataset extends our knowledge of the metabolic potential of several uncultured phyla. Within the sediments, there is redundancy in the genomic potential in different lineages, often distinct phyla, for essential biogeochemical processes. We were able to chart the flow of carbon and nutrients through the multiple geochemical layers of bacterial processing and reveal potential ecological interactions within the communities.http://deepblue.lib.umich.edu/bitstream/2027.42/111044/1/40168_2015_Article_77.pd
Transcriptome Alteration in the Diabetic Heart by Rosiglitazone: Implications for Cardiovascular Mortality
BACKGROUND: Recently, the type 2 diabetes medication, rosiglitazone, has come under scrutiny for possibly increasing the risk of cardiac disease and death. To investigate the effects of rosiglitazone on the diabetic heart, we performed cardiac transcriptional profiling and imaging studies of a murine model of type 2 diabetes, the C57BL/KLS-lepr(db)/lepr(db) (db/db) mouse. METHODS AND FINDINGS: We compared cardiac gene expression profiles from three groups: untreated db/db mice, db/db mice after rosiglitazone treatment, and non-diabetic db/+ mice. Prior to sacrifice, we also performed cardiac magnetic resonance (CMR) and echocardiography. As expected, overall the db/db gene expression signature was markedly different from control, but to our surprise was not significantly reversed with rosiglitazone. In particular, we have uncovered a number of rosiglitazone modulated genes and pathways that may play a role in the pathophysiology of the increase in cardiac mortality as seen in several recent meta-analyses. Specifically, the cumulative upregulation of (1) a matrix metalloproteinase gene that has previously been implicated in plaque rupture, (2) potassium channel genes involved in membrane potential maintenance and action potential generation, and (3) sphingolipid and ceramide metabolism-related genes, together give cause for concern over rosiglitazone's safety. Lastly, in vivo imaging studies revealed minimal differences between rosiglitazone-treated and untreated db/db mouse hearts, indicating that rosiglitazone's effects on gene expression in the heart do not immediately turn into detectable gross functional changes. CONCLUSIONS: This study maps the genomic expression patterns in the hearts of the db/db murine model of diabetes and illustrates the impact of rosiglitazone on these patterns. The db/db gene expression signature was markedly different from control, and was not reversed with rosiglitazone. A smaller number of unique and interesting changes in gene expression were noted with rosiglitazone treatment. Further study of these genes and molecular pathways will provide important insights into the cardiac decompensation associated with both diabetes and rosiglitazone treatment
Development of a context model to prioritize drug safety alerts in CPOE systems
Background: Computerized physician order entry systems (CPOE) can reduce the number of medication errors and adverse drug events (ADEs) in healthcare institutions. Unfortunately, they tend to produce a large number of partly irrelevant alerts, in turn leading to alert overload and causing alert fatigue. The objective of this work is to identify factors that can be used to prioritize and present alerts depending on the 'context' of a clinical situation. Methods: We used a combination of literature searches and expert interviews to identify and validate the possible context factors. The internal validation of the context factors was performed by calculating the inter-rater agreement of two researcher's classification of 33 relevant articles. Results: We developed a context model containing 20 factors. We grouped these context factors into three categories: characteristics of the patient or case (e. g. clinical status of the patient); characteristics of the organizational unit or user (e. g. professional experience of the user); and alert characteristics (e. g. severity of the effect). The internal validation resulted in nearly perfect agreement (Cohen's Kappa value of 0.97). Conclusion: To our knowledge, this is the first structured attempt to develop a comprehensive context model for prioritizing drug safety alerts in CPOE systems. The outcome of this work can be used to develop future tailored drug safety alerting in CPOE systems
Pseudotumoural soft tissue lesions of the foot and ankle: a pictorial review
In the foot and ankle region, benign neoplasms and pseudotumoural soft tissue lesions are significantly more frequent than malignant tumours. The pseudotumoural lesions constitute a heterogeneous group, with highly varied aetiology and histopathology. This article reviews the imaging features of the most common pseudotumours of the soft tissues in the foot and ankle. Although the imaging characteristics of several of the lesions discussed are non-specific, combining them with lesion location and clinical features allows the radiologist to suggest a specific diagnosis in most cases
Dynamics and distribution of bacterial and archaeal communities in oil-contaminated temperate coastal mudflat mesocosms
Mudflats are ecologically important habitats that are susceptible to oil pollution, but intervention is difficult in these fine-grained sediments, and so clean-up usually relies on natural attenuation. Therefore, we investigated the impact of crude oil on the bacterial, diatom and archaeal communities within the upper parts of the diatom-dominated sediment and the biofilm that detached from the surface at high tide. Biodegradation of petroleum hydrocarbons was rapid, with a 50 % decrease in concentration in the 0–2-mm section of sediment by 3 days, indicating the presence of a primed hydrocarbon-degrading community. The biggest oil-induced change was in the biofilm that detached from the sediment, with increased relative abundance of several types of diatom and of the obligately hydrocarbonoclastic Oleibacter sp., which constituted 5 % of the pyrosequences in the oiled floating biofilm on day 3 compared to 0.6 % in the non-oiled biofilm. Differences in bacterial community composition between oiled and non-oiled samples from the 0–2-mm section of sediment were only significant at days 12 to 28, and the 2–4-mm-sediment bacterial communities were not significantly affected by oil. However, specific members of the Chromatiales were detected (1 % of sequences in the 2–4-mm section) only in the oiled sediment, supporting other work that implicates them in anaerobic hydrocarbon degradation. Unlike the Bacteria, the archaeal communities were not significantly affected by oil. In fact, changes in community composition over time, perhaps caused by decreased nutrient concentration and changes in grazing pressure, overshadowed the effect of oil for both Bacteria and Archaea. Many obligate hydrocarbonoclastic and generalist oil-degrading bacteria were isolated, and there was little correspondence between the isolates and the main taxa detected by pyrosequencing of sediment-extracted DNA, except for Alcanivorax, Thalassolituus, Cycloclasticus and Roseobacter spp., which were detected by both methods
The complex genetic landscape of familial MDS and AML reveals pathogenic germline variants.
The inclusion of familial myeloid malignancies as a separate disease entity in the revised WHO classification has renewed efforts to improve the recognition and management of this group of at risk individuals. Here we report a cohort of 86 acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) families with 49 harboring germline variants in 16 previously defined loci (57%). Whole exome sequencing in a further 37 uncharacterized families (43%) allowed us to rationalize 65 new candidate loci, including genes mutated in rare hematological syndromes (ADA, GP6, IL17RA, PRF1 and SEC23B), reported in prior MDS/AML or inherited bone marrow failure series (DNAH9, NAPRT1 and SH2B3) or variants at novel loci (DHX34) that appear specific to inherited forms of myeloid malignancies. Altogether, our series of MDS/AML families offer novel insights into the etiology of myeloid malignancies and provide a framework to prioritize variants for inclusion into routine diagnostics and patient management
- …