105 research outputs found
Living with muscular dystrophy: health related quality of life consequences for children and adults
<p>Abstract</p> <p>Background</p> <p>Muscular dystrophies are chronic diseases manifesting with progressive muscle weakness leading to decreasing activities and participation. To understand the impact on daily life, it is important to determine patients' quality of life.</p> <p>Objective</p> <p>To investigate Health Related Quality of Life (HRQoL) of children and adults with muscular dystrophy (MD), and to study the influence of type and severity of MD on HRQoL in adult patients.</p> <p>Methods</p> <p>Age-related HRQoL questionnaires were administered to 40 children (8–17 years), and 67 adult patients with muscular dystrophies.</p> <p>Results</p> <p>Significant differences in HRQoL were found in children and adults with MD compared to healthy controls. Patients with Becker muscular dystrophy reported a better HRQoL on the several scales compared to patients with other MDs. Severity was associated with worse fine motor functioning and social functioning in adult patients.</p> <p>Conclusion</p> <p>This is one of the first studies describing HRQoL of patients with MD using validated instruments in different age groups. The results indicate that having MD negatively influences the HRQoL on several domains.</p
Cortical injury in multiple sclerosis; the role of the immune system
The easily identifiable, ubiquitous demyelination and neuronal damage that occurs within the cerebral white matter of patients with multiple sclerosis (MS) has been the subject of extensive study. Accordingly, MS has historically been described as a disease of the white matter. Recently, the cerebral cortex (gray matter) of patients with MS has been recognized as an additional and major site of disease pathogenesis. This acknowledgement of cortical tissue damage is due, in part, to more powerful MRI that allows detection of such injury and to focused neuropathology-based investigations. Cortical tissue damage has been associated with inflammation that is less pronounced to that which is associated with damage in the white matter. There is, however, emerging evidence that suggests cortical damage can be closely associated with robust inflammation not only in the parenchyma, but also in the neighboring meninges. This manuscript will highlight the current knowledge of inflammation associated with cortical tissue injury. Historical literature along with contemporary work that focuses on both the absence and presence of inflammation in the cerebral cortex and in the cerebral meninges will be reviewed
Transcriptional responses of Burkholderia cenocepacia to polymyxin B in isogenic strains with diverse polymyxin B resistance phenotypes
<p>Abstract</p> <p>Background</p> <p><it>Burkholderia cenocepacia </it>is a Gram-negative opportunistic pathogen displaying high resistance to antimicrobial peptides and polymyxins. We identified mechanisms of resistance by analyzing transcriptional changes to polymyxin B treatment in three isogenic <it>B. cenocepacia </it>strains with diverse polymyxin B resistance phenotypes: the polymyxin B-resistant parental strain K56-2, a polymyxin B-sensitive K56-2 mutant strain with heptoseless lipopolysaccharide (LPS) (RSF34), and a derivative of RSF34 (RSF34 4000B) isolated through multiple rounds of selection in polymyxin B that despite having a heptoseless LPS is highly polymyxin B-resistant.</p> <p>Results</p> <p>A heptoseless LPS mutant of <it>B. cenocepacia </it>was passaged through multiple rounds of selection to regain high levels of polymyxin B-resistance. This process resulted in various phenotypic changes in the isolate that could contribute to polymyxin B resistance and are consistent with LPS-independent changes in the outer membrane. The transcriptional response of three <it>B. cenocepacia </it>strains to subinhibitory concentrations of polymyxin B was analyzed using microarray analysis and validated by quantitative Real Time-PCR. There were numerous baseline changes in expression between the three strains in the absence of polymyxin B. In both K56-2 and RSF34, similar transcriptional changes upon treatment with polymyxin B were found and included upregulation of various genes that may be involved in polymyxin B resistance and downregulation of genes required for the synthesis and operation of flagella. This last result was validated phenotypically as both swimming and swarming motility were impaired in the presence of polymyxin B. RSF34 4000B had altered the expression in a larger number of genes upon treatment with polymyxin B than either K56-2 or RSF34, but the relative fold-changes in expression were lower.</p> <p>Conclusions</p> <p>It is possible to generate polymyxin B-resistant isolates from polymyxin B-sensitive mutant strains of <it>B. cenocepacia</it>, likely due to the multifactorial nature of polymyxin B resistance of this bacterium. Microarray analysis showed that <it>B. cenocepacia </it>mounts multiple transcriptional responses following exposure to polymyxin B. Polymyxin B-regulated genes identified in this study may be required for polymyxin B resistance, which must be tested experimentally. Exposure to polymyxin B also decreases expression of flagellar genes resulting in reduced swimming and swarming motility.</p
S100B as a potential biomarker and therapeutic target in multiple sclerosis
Multiple sclerosis (MS) pathology is characterized by neuroinflammation and demyelination. Recently, the inflammatory molecule S100B was identified in cerebrospinal fluid (CSF) and serum of MS patients. Although seen as an astrogliosis marker, lower/physiological levels of S100B are involved in oligodendrocyte differentiation/maturation. Nevertheless, increased S100B levels released upon injury may induce glial reactivity and oligodendrocyte demise, exacerbating tissue damage during an MS episode or delaying the following remyelination. Here, we aimed to unravel the functional role of S100B in the pathogenesis of MS. Elevated S100B levels were detected in the CSF of relapsing-remitting MS patients at diagnosis. Active demyelinating MS lesions showed increased expression of S100B and its receptor, the receptor for advanced glycation end products (RAGE), in the lesion area, while chronic active lesions displayed increased S100B in demyelinated areas with lower expression of RAGE in the rim. Interestingly, reactive astrocytes were identified as the predominant cellular source of S100B, whereas RAGE was expressed by activated microglia/macrophages. Using an ex vivo demyelinating model, cerebral organotypic slice cultures treated with lysophosphatidylcholine (LPC), we observed a marked elevation of S100B upon demyelination, which co-localized mostly with astrocytes. Inhibition of S100B action using a directed antibody reduced LPC-induced demyelination, prevented astrocyte reactivity and abrogated the expression of inflammatory and inflammasome-related molecules. Overall, high S100B expression in MS patient samples suggests its usefulness as a diagnostic biomarker for MS, while the beneficial outcome of its inhibition in our demyelinating model indicates S100B as an emerging therapeutic target in MS.This work was supported by Medal of Honor L’Oréal
for Women in Science (FCT, UNESCO, L’Óreal) and innovation
grant (Ordem dos Farmacêuticos) to AF, a post-doctoral grant from
Fundação para a Ciência e Tecnologia (FCT-SFRH/BPD/96794/2013)
and a DuPré Grant from the European Committee for Treatment and
Research in Multiple Sclerosis (ECTRIMS) to AB, and by FCT-Pest-
OE/SAU/UI4013 to iMed.ULisboa.info:eu-repo/semantics/publishedVersio
20-Year Risks of Breast-Cancer Recurrence after Stopping Endocrine Therapy at 5 Years
The administration of endocrine therapy for 5 years substantially reduces recurrence rates during and after treatment in women with early-stage, estrogen-receptor (ER)-positive breast cancer. Extending such therapy beyond 5 years offers further protection but has additional side effects. Obtaining data on the absolute risk of subsequent distant recurrence if therapy stops at 5 years could help determine whether to extend treatment
Long-term outcomes for neoadjuvant versus adjuvant chemotherapy in early breast cancer: meta-analysis of individual patient data from ten randomised trials
Background
Neoadjuvant chemotherapy (NACT) for early breast cancer can make breast-conserving surgery more feasible and might be more likely to eradicate micrometastatic disease than might the same chemotherapy given after surgery. We investigated the long-term benefits and risks of NACT and the influence of tumour characteristics on outcome with a collaborative meta-analysis of individual patient data from relevant randomised trials.
Methods
We obtained information about prerandomisation tumour characteristics, clinical tumour response, surgery, recurrence, and mortality for 4756 women in ten randomised trials in early breast cancer that began before 2005 and compared NACT with the same chemotherapy given postoperatively. Primary outcomes were tumour response, extent of local therapy, local and distant recurrence, breast cancer death, and overall mortality. Analyses by intention-to-treat used standard regression (for response and frequency of breast-conserving therapy) and log-rank methods (for recurrence and mortality).
Findings
Patients entered the trials from 1983 to 2002 and median follow-up was 9 years (IQR 5–14), with the last follow-up in 2013. Most chemotherapy was anthracycline based (3838 [81%] of 4756 women). More than two thirds (1349 [69%] of 1947) of women allocated NACT had a complete or partial clinical response. Patients allocated NACT had an increased frequency of breast-conserving therapy (1504 [65%] of 2320 treated with NACT vs 1135 [49%] of 2318 treated with adjuvant chemotherapy). NACT was associated with more frequent local recurrence than was adjuvant chemotherapy: the 15 year local recurrence was 21·4% for NACT versus 15·9% for adjuvant chemotherapy (5·5% increase [95% CI 2·4–8·6]; rate ratio 1·37 [95% CI 1·17–1·61]; p=0·0001). No significant difference between NACT and adjuvant chemotherapy was noted for distant recurrence (15 year risk 38·2% for NACT vs 38·0% for adjuvant chemotherapy; rate ratio 1·02 [95% CI 0·92–1·14]; p=0·66), breast cancer mortality (34·4% vs 33·7%; 1·06 [0·95–1·18]; p=0·31), or death from any cause (40·9% vs 41·2%; 1·04 [0·94–1·15]; p=0·45).
Interpretation
Tumours downsized by NACT might have higher local recurrence after breast-conserving therapy than might tumours of the same dimensions in women who have not received NACT. Strategies to mitigate the increased local recurrence after breast-conserving therapy in tumours downsized by NACT should be considered—eg, careful tumour localisation, detailed pathological assessment, and appropriate radiotherapy
A full-height waveguide to thin-film microstrip transition with exceptional RF bandwidth and coupling efficiency
We describe a waveguide to thin-film microstrip transition for high-performance submillimetre wave and teraherz applications. The proposed constant-radius probe couples thin-film microstrip line, to full-height rectangular waveguide with better than 99% efficiency (VSWR ≤ 1.20) and 45% fractional bandwidth. Extensive HFSS simulations, backed by scale-model measurements, are presented in the paper. By selecting the substrate material and probe radius, any real impedance between ≈ 15-60 Ω can be achieved. The radial probe gives significantly improved performance over other designs discussed in the literature. Although our primary application is submillimetre wave superconducting mixers, we show that membrane techniques should allow broad-band waveguide components to be constructed for the THz frequency range
In-situ TEM study of the crystallization of thin films composed of Sb3.6Te with Ge
This paper addresses the crystallization of amorphous Sb3.6Te films (40 nm thick) and 5 at.% Ge containing Sb3.6Te films (10, 20 and 40 nm thick) as studied using in-situ annealing in a Transmission Electron Microscope (TEM). These materials show growth-dominated crystallization, in contrast to Ge2Sb2Tc5 that shows nucleation-dominated crystallization. Particularly the crystal-growth velocity in these systems is measured as a function of temperature from which the activation energy for growth can be derived. The strong effect of the 5 at.% Ge addition on the total crystallization behavior is revealed: Ge increases the crystallization temperature (from 95 to 150 degreesC), increases the activation energy for growth (from 1.58 to 2.37 eV), increases the nucleation rate and decreases the growth anisotropy
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