249 research outputs found
Effects of beta-alanine supplementation on brain homocarnosine/carnosine signal and cognitive function: an exploratory study
Objectives: Two independent studies were conducted to examine the effects of 28 d of beta-alanine supplementation at 6.4 g d-1 on brain homocarnosine/carnosine signal in omnivores and vegetarians (Study 1) and on cognitive function before and after exercise in trained cyclists (Study 2). Methods: In Study 1, seven healthy vegetarians (3 women and 4 men) and seven age- and sex-matched omnivores undertook a brain 1H-MRS exam at baseline and after beta-alanine supplementation. In study 2, nineteen trained male cyclists completed four 20-Km cycling time trials (two pre supplementation and two post supplementation), with a battery of cognitive function tests (Stroop test, Sternberg paradigm, Rapid Visual Information Processing task) being performed before and after exercise on each occasion. Results: In Study 1, there were no within-group effects of beta-alanine supplementation on brain homocarnosine/carnosine signal in either vegetarians (p = 0.99) or omnivores (p = 0.27); nor was there any effect when data from both groups were pooled (p = 0.19). Similarly, there was no group by time interaction for brain homocarnosine/carnosine signal (p = 0.27). In study 2, exercise improved cognitive function across all tests (P0.05) of beta-alanine supplementation on response times or accuracy for the Stroop test, Sternberg paradigm or RVIP task at rest or after exercise. Conclusion: 28 d of beta-alanine supplementation at 6.4g d-1 appeared not to influence brain homocarnosine/ carnosine signal in either omnivores or vegetarians; nor did it influence cognitive function before or after exercise in trained cyclists
Brentuximab vedotin in relapsed/refractory Hodgkin lymphoma post-autologous stem cell transplant : a cost-effectiveness analysis in Scotland
OBJECTIVE: To evaluate cost-effectiveness of brentuximab vedotin in patients with relapsed/refractory Hodgkin lymphoma who have received autologous stem cell transplantation, from a Scottish healthcare payer perspective. METHODS: A Microsoft Excel-based partitioned survival model comprising three health states (progression-free survival [PFS], post-progression survival, and death) was developed. Relevant comparators were chemotherapy with or without radiotherapy (C/R) and C/R with intent to allogeneic hematopoietic stem cell transplantation (alloSCT). Data were obtained from the pivotal phase II single-arm trial in 102 patients (SG035-0003; NCT00848926), a systematic literature review and clinical expert opinions (where empirical evidence was unavailable). PFS and overall survival for brentuximab vedotin were estimated using 5-year follow-up data from SG035-0003, and extrapolated using event rates observed for comparator treatments from published survival data. Resource use included drug acquisition and administration; alloSCT; treatment of adverse events; and long-term follow-up. Deterministic and probabilistic sensitivity analyses were conducted to evaluate the impact of uncertainty. RESULTS: In the base case, the incremental cost-effectiveness ratio (ICER) for brentuximab vedotin was £38,769 per quality-adjusted life year (QALY) vs C/R, whereas C/R with intent to alloSCT was dominated by brentuximab vedotin. ICERs for brentuximab vedotin generated by the deterministic sensitivity analysis ranged between £32,000-£54,000 per QALY. Including productivity benefits reduced the ICER to £28,881 per QALY. LIMITATIONS: Limitations include lack of comparative data from this single arm study and the heterogeneous population. Inconsistent baseline characteristic reporting across studies prevented complete assessment of heterogeneity and the extent of potential bias in clinical and cost-effectiveness estimates. CONCLUSIONS: Although the base case ICER is above the threshold usually applied in Scotland, it is relatively low compared with other orphan drugs, and lower than the ICER generated using a previous data cut of SG035-0003 that informed a positive recommendation from the Scottish Medicines Consortium, under its decision-making framework for assessment of ultra-orphan medicines
Plasma triglyceride concentrations are rapidly reduced following individual bouts of endurance exercise in women
It is known that chronic endurance training leads to improvements in the lipoprotein profile, but less is known about changes that occur during postexercise recovery acutely. We analyzed triglyceride (TG), cholesterol classes and apolipoproteins in samples collected before, during and after individual moderate- and hard-intensity exercise sessions in men and women that were isoenergetic between intensities. Young healthy men (n = 9) and young healthy women (n = 9) were studied under three different conditions with diet unchanged between trials: (1) before, during and 3 h after 90 min of exercise at 45% VO2peak (E45); (2) before, during and 3 h after 60 min of exercise at 65% VO2peak (E65), and (3) in a time-matched sedentary control trial (C). At baseline, high-density lipoprotein cholesterol (HDL-C) was higher in women than men (P < 0.05). In men and in women, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), HDL-C, apolipoprotein A-I (apoA-I), apolipoprotein B (apoB), and LDL peak particle size were unaltered by exercise either during exertion or after 3 h of recovery. In women, but not in men, average plasma TG was significantly reduced below C at 3 h postexercise by approximately 15% in E45 and 25% in E65 (P < 0.05) with no significant difference between exercise intensities. In summary, plasma TG concentration rapidly declines following exercise in women, but not in men. These results demonstrate an important mechanism by which each individual exercise session may incrementally reduce the risk for cardiovascular disease (CVD) in women
Lack of evidence of disease contamination in ovarian tissue harvested for cryopreservation from patients with Hodgkin lymphoma and analysis of factors predictive of oocyte yield
Ovarian cryopreservation is a promising technique to preserve fertility in women with Hodgkin lymphoma (HL) treated with chemotherapy. Thus, the aim of this study was to examine harvested ovarian tissue for subclinical involvement by HL by morphology/immunohistochemistry, and to define patient and treatment factors predictive of oocyte yield. This was a retrospective analysis of 26 ovarian tissue samples harvested for cryopreservation from women with HL. Histology, immunohistochemistry and follicle density (number mm−3) was examined. Disease status and preharvest chemotherapy details were obtained on 24 patients. The median age was 22 years (range 13–29). Seven of 24 patients had infradiaphragmatic disease at time of harvest. Nine of 20 patients had received chemotherapy preharvest (ABVD (Adriamycin®, Bleomycin, Vinblastine and Dacarbazine)=7, other regimens=2). The seven receiving ABVD showed no difference in follicle density compared to patients not receiving treatment (n=14); (median=1555 vs 1620 mm3 P=0.97). Follicle density measurement showed no correlation with patient age (R2=0.0001, P=0.99). There was no evidence of HL involvement in the 26 samples examined (95% CI=0–11%). In conclusion, subclinical involvement of HL has not been identified in ovarian tissue, even when patients have infradiaphragmatic disease. Furthermore, the quality of tissue harvested does not appear to be adversely affected by patient's age or prior ABVD chemotherapy
Bacterial Diversity in Oral Samples of Children in Niger with Acute Noma, Acute Necrotizing Gingivitis, and Healthy Controls
Noma is a devastating gangrenous disease that leads to severe facial disfigurement, but its cause remains unknown. It is associated with high morbidity and mortality and affects almost exclusively young children living in remote areas of developing countries, particularly in Africa. Several factors have been linked to the disease, including malnutrition, immune dysfunction, lack of oral hygiene, and lesions of the mucosal gingival barrier, particularly the presence of acute necrotizing gingivitis, and a potentially non-identified bacterial factor acting as a trigger for the disease. This study assessed the total bacterial diversity present in 69 oral samples of 55 children in Niger with or without acute noma or acute necrotizing gingivitis using culture-independent molecular methods. Analysis of bacterial composition and frequency showed that diseased and healthy site bacterial communities are composed of similar bacteria, but differ in the prevalence of a limited group of phylotypes. We failed to identify a causative infectious agent for noma or acute necrotizing gingivitis as the most plausible pathogens for both conditions were present also in sizeable numbers in healthy subjects. Most likely, the disease is initiated by a synergistic combination of several bacterial species, and not a single agent
Effects of Hydrographic Variability on the Spatial, Seasonal and Diel Diving Patterns of Southern Elephant Seals in the Eastern Weddell Sea
Weddell Sea hydrography and circulation is driven by influx of Circumpolar Deep Water (CDW) from the Antarctic Circumpolar Current (ACC) at its eastern margin. Entrainment and upwelling of this high-nutrient, oxygen-depleted water mass within the Weddell Gyre also supports the mesopelagic ecosystem within the gyre and the rich benthic community along the Antarctic shelf. We used Conductivity-Temperature-Depth Satellite Relay Data Loggers (CTD-SRDLs) to examine the importance of hydrographic variability, ice cover and season on the movements and diving behavior of southern elephant seals in the eastern Weddell Sea region during their overwinter feeding trips from Bouvetøya. We developed a model describing diving depth as a function of local time of day to account for diel variation in diving behavior. Seals feeding in pelagic ice-free waters during the summer months displayed clear diel variation, with daytime dives reaching 500-1500 m and night-time targeting of the subsurface temperature and salinity maxima characteristic of CDW around 150–300 meters. This pattern was especially clear in the Weddell Cold and Warm Regimes within the gyre, occurred in the ACC, but was absent at the Dronning Maud Land shelf region where seals fed benthically. Diel variation was almost absent in pelagic feeding areas covered by winter sea ice, where seals targeted deep layers around 500–700 meters. Thus, elephant seals appear to switch between feeding strategies when moving between oceanic regimes or in response to seasonal environmental conditions. While they are on the shelf, they exploit the locally-rich benthic ecosystem, while diel patterns in pelagic waters in summer are probably a response to strong vertical migration patterns within the copepod-based pelagic food web. Behavioral flexibility that permits such switching between different feeding strategies may have important consequences regarding the potential for southern elephant seals to adapt to variability or systematic changes in their environment resulting from climate change
Extraction of pure components from overlapped signals in gas chromatography-mass spectrometry (GC-MS)
Gas chromatography-mass spectrometry (GC-MS) is a widely used analytical technique for the identification and quantification of trace chemicals in complex mixtures. When complex samples are analyzed by GC-MS it is common to observe co-elution of two or more components, resulting in an overlap of signal peaks observed in the total ion chromatogram. In such situations manual signal analysis is often the most reliable means for the extraction of pure component signals; however, a systematic manual analysis over a number of samples is both tedious and prone to error. In the past 30 years a number of computational approaches were proposed to assist in the process of the extraction of pure signals from co-eluting GC-MS components. This includes empirical methods, comparison with library spectra, eigenvalue analysis, regression and others. However, to date no approach has been recognized as best, nor accepted as standard. This situation hampers general GC-MS capabilities, and in particular has implications for the development of robust, high-throughput GC-MS analytical protocols required in metabolic profiling and biomarker discovery. Here we first discuss the nature of GC-MS data, and then review some of the approaches proposed for the extraction of pure signals from co-eluting components. We summarize and classify different approaches to this problem, and examine why so many approaches proposed in the past have failed to live up to their full promise. Finally, we give some thoughts on the future developments in this field, and suggest that the progress in general computing capabilities attained in the past two decades has opened new horizons for tackling this important problem
NOMA: A Preventable “Scourge” of African Children
Noma is a serious orofacial gangrene originating intraorally in the gingival-oral mucosa complex before spreading extraorally to produce a visibly destructive ulcer. Although cases of noma are now rarely reported in the developed countries, it is still prevalent among children in third world countries, notably in sub-Sahara Africa, where poverty, ignorance, malnutrition, and preventable childhood infections are still common. This review summarizes historical, epidemiological, management, and research updates on noma with suggestions for its prevention and ultimate global eradication. The global annual incidence remains high at about 140,000 cases, with a mortality rate exceeding 90% for untreated diseases. Where the patients survive, noma defects result in unsightly facial disfigurement, intense scarring, trismus, oral incompetence, and social alienation. Although the etiology has long been held to be infectious, a definitive causal role between microorganisms cited, and noma has been difficult to establish. The management of noma with active disease requires antibiotics followed by reconstructive surgery. Current research efforts are focused towards a comprehensive understanding of the epidemiology, and further elucidation of the microbiology and pathogenesis of noma
Anti-cancer drug validation: the contribution of tissue engineered models
Abstract Drug toxicity frequently goes concealed until clinical trials stage, which is the most challenging, dangerous and expensive stage of drug development. Both the cultures of cancer cells in traditional 2D assays and animal studies have limitations that cannot ever be unraveled by improvements in drug-testing protocols. A new generation of bioengineered tumors is now emerging in response to these limitations, with potential to transform drug screening by providing predictive models of tumors within their tissue context, for studies of drug safety and efficacy. Considering the NCI60, a panel of 60 cancer cell lines representative of 9 different cancer types: leukemia, lung, colorectal, central nervous system (CNS), melanoma, ovarian, renal, prostate and breast, we propose to review current Bstate of art^ on the 9 cancer types specifically addressing the 3D tissue models that have been developed and used in drug discovery processes as an alternative to complement their studyThis article is a result of the project FROnTHERA (NORTE-01-0145-FEDER-000023), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This article was also supported by the EU Framework Programme for Research and Innovation HORIZON 2020 (H2020) under grant agreement n° 668983 — FoReCaST. FCT distinction attributed to Joaquim M. Oliveira (IF/00423/2012) and Vitor M. Correlo (IF/01214/2014) under the Investigator FCT program is also greatly acknowledged.info:eu-repo/semantics/publishedVersio
Quantitative metabolomics based on gas chromatography mass spectrometry: status and perspectives
Metabolomics involves the unbiased quantitative and qualitative analysis of the complete set of metabolites present in cells, body fluids and tissues (the metabolome). By analyzing differences between metabolomes using biostatistics (multivariate data analysis; pattern recognition), metabolites relevant to a specific phenotypic characteristic can be identified. However, the reliability of the analytical data is a prerequisite for correct biological interpretation in metabolomics analysis. In this review the challenges in quantitative metabolomics analysis with regards to analytical as well as data preprocessing steps are discussed. Recommendations are given on how to optimize and validate comprehensive silylation-based methods from sample extraction and derivatization up to data preprocessing and how to perform quality control during metabolomics studies. The current state of method validation and data preprocessing methods used in published literature are discussed and a perspective on the future research necessary to obtain accurate quantitative data from comprehensive GC-MS data is provided
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