Two‐dimensional gel electrophoresis (2‐DE) with immobilized pH gradients (IPGs) combined with protein identification by mass spectrometry (MS) is currently the workhorse for proteomics. In spite of ...promising alternative or complementary technologies (e.g. multidimensional protein identification technology, stable isotope labelling, protein or antibody arrays) that have emerged recently, 2‐DE is currently the only technique that can be routinely applied for parallel quantitative expression profiling of large sets of complex protein mixtures such as whole cell lysates. 2‐DE enables the separaration of complex mixtures of proteins according to isoelectric point (pI), molecular mass (Mr), solubility, and relative abundance. Furthermore, it delivers a map of intact proteins, which reflects changes in protein expression level, isoforms or post‐translational modifications. This is in contrast to liquid chromatography‐tandem mass spectrometry based methods, which perform analysis on peptides, where Mr and pI information is lost, and where stable isotope labelling is required for quantitative analysis. Today's 2‐DE technology with IPGs (Görg et al., Electrophoresis 2000, 21, 1037–1053), has overcome the former limitations of carrier ampholyte based 2‐DE (O'Farrell, J. Biol. Chem. 1975, 250, 4007–4021) with respect to reproducibility, handling, resolution, and separation of very acidic and/or basic proteins. The development of IPGs between pH 2.5–12 has enabled the analysis of very alkaline proteins and the construction of the corresponding databases. Narrow‐overlapping IPGs provide increased resolution (δpI = 0.001) and, in combination with prefractionation methods, the detection of low abundance proteins. Depending on the gel size and pH gradient used, 2‐DE can resolve more than 5000 proteins simultaneously (˜2000 proteins routinely), and detect and quantify < 1 ng of protein per spot. In this article we describe the current 2‐DE/MS workflow including the following topics: sample preparation, protein solubilization, and prefractionation; protein separation by 2‐DE with IPGs; protein detection and quantitation; computer assisted analysis of 2‐DE patterns; protein identification and characterization by MS; two‐dimensional protein databases.
We report long-term changes in population size of three species of sympatrically breeding pygoscelid penguins: Adélie (Pygoscelis adeliae), chinstrap (Pygoscelis antarctica) and gentoo (Pygoscelis ...papua ellsworthii) over a 38 year period at Signy Island, South Orkney Islands, based on annual counts from selected colonies and decadal all-island systematic counts of occupied nests. Comparing total numbers of breeding pairs over the whole island from 1978/79 to 2015/16 revealed varying fortunes: gentoo penguin pairs increased by 255%, (3.5% per annum), chinstrap penguins declined by 68% (-3.6% per annum) and Adélie penguins declined by 42% (-1.5% per annum). The chinstrap population has declined steadily over the last four decades. In contrast, Adélie and gentoo penguins have experienced phases of population increase and decline. Annual surveys of selected chinstrap and Adélie colonies produced similar trends from those revealed by island-wide surveys, allowing total island population trends to be inferred relatively well. However, while the annual colony counts of chinstrap and Adélie penguins showed a trend consistent in direction with the results from all-island surveys, the magnitude of estimated population change was markedly different between colony wide and all island counts. Annual population patterns suggest that pair numbers in the study areas partly reflect immigration and emigration of nesting birds between different parts of the island. Breeding success for all three species remained broadly stable over time in the annually monitored colonies. Breeding success rates in gentoo and chinstrap penguins were strongly correlated, despite the differing trends in population size. This study shows the importance of effective, standardised monitoring to accurately determine long-term population trajectories. Our results indicate significant declines in the Adélie and chinstrap penguin populations at Signy Island over the last five decades, and a gradual increase in gentoo breeding pairs.
We designed a multicenter randomized trial to compare 3 approaches to the initial respiratory management of preterm neonates: prophylactic surfactant followed by a period of mechanical ventilation ...(prophylactic surfactant PS); prophylactic surfactant with rapid extubation to bubble nasal continuous positive airway pressure (intubate-surfactant-extubate ISX) or initial management with bubble continuous positive airway pressure and selective surfactant treatment (nCPAP).
Neonates born at 26 0/7 to 29 6/7 weeks' gestation were enrolled at participating Vermont Oxford Network centers and randomly assigned to PS, ISX, or nCPAP groups before delivery. Primary outcome was the incidence of death or bronchopulmonary dysplasia (BPD) at 36 weeks' postmenstrual age.
648 infants enrolled at 27 centers. The study was halted before the desired sample size was reached because of declining enrollment. When compared with the PS group, the relative risk of BPD or death was 0.78 (95% confidence interval: 0.59-1.03) for the ISX group and 0.83 (95% confidence interval: 0.64-1.09) for the nCPAP group. There were no statistically significant differences in mortality or other complications of prematurity. In the nCPAP group, 48% were managed without intubation and ventilation, and 54% without surfactant treatment.
Preterm neonates were initially managed with either nCPAP or PS with rapid extubation to nCPAP had similar clinical outcomes to those treated with PS followed by a period of mechanical ventilation. An approach that uses early nCPAP leads to a reduction in the number of infants who are intubated and given surfactant.
Cannabis is the most widely used illicit drug in the U.S., and the number of illicit and licit users is rising. Lasting neurocognitive changes or deficits as a result of use are frequently noted ...despite a lack of clarity in the scientific literature. In an effort to resolve inconsistencies in the evidence of lasting residual effects of cannabis use, we conducted two meta-analyses. First, we updated a previous meta-analysis on broad nonacute cognitive effects of cannabis use through inclusion of newer studies. In a second meta-analysis, we focused on evidence for lasting residual effects by including only studies that tested users after at least 25 days of abstinence. In the first meta-analysis, 33 studies met inclusion criteria. Results indicated a small negative effect for global neurocognitive performance as well for most cognitive domains assessed. Unfortunately, methodological limitations of these studies prevented the exclusion of withdrawal symptoms as an explanation for observed effects. In the second meta-analysis, 13 of the original 33 studies met inclusion criteria. Results indicated no significant effect of cannabis use on global neurocognitive performance or any effect on the eight assessed domains. Overall, these meta-analyses demonstrate that any negative residual effects on neurocognitive performance attributable to either cannabis residue or withdrawal symptoms are limited to the first 25 days of abstinence. Furthermore, there was no evidence for enduring negative effects of cannabis use.
This book is the first to consider comprehensively and systematically the law and practice of advance directives across Asia. It will thus be important not only as a reference volume that documents ...how advance directives are regulated and used throughout Asia, but also as an exploration of the concept of the advance directive itself, in context. By examining how advance directives operate in Asian countries, we will also shed light on the principle of personal autonomy in this context, alongside other values and religious and socio-cultural factors that shape health and care decision-making. As such, this book will have broad appeal not only to Asian scholars, students, policymakers and practitioners in the fields of health law and ethics and end-of-life care more generally, but will also be of wider interest to an international academic audience in the fields of law, ethics and health and social care research. This title is also available as open access on Cambridge Core.
Abstract
The metalloenzyme arginase hydrolyzes l-arginine to produce l-ornithine and urea. In bacteria, arginase has important functions in basic nitrogen metabolism and redistribution, production of ...the key metabolic precursor l-ornithine, stress resistance and pathogenesis. We describe the regulation and specific functions of the arginase pathway as well as summarize key characteristics of related arginine catabolic pathways. The use of arginase-derived ornithine as a precursor molecule is reviewed. We discuss the biochemical and transcriptional regulation of arginine metabolism, including arginase, with the latter topic focusing on the RocR and AhrC transcriptional regulators in the model organism Bacillus subtilis. Finally, we consider similarities and contrasts in the structure and catalytic mechanism of the arginases from Bacillus caldovelox and Helicobacter pylori. The overall aim of this review is to provide a panorama of the diversity of physiological functions, regulation and biochemical features of arginases in a variety of bacterial species.
Arginases from different bacterial taxa reveal an impressive diversity of structural and catalytic features, as well as different physiological functions that include nutrition, secondary metabolite production, stress resistance and pathogenesis.
Robust physical activity after liver transplantation is an important determinant of longterm health, similar in its importance to the value of pretransplant activity for withstanding the immediate ...stress of transplantation. Although transplantation normally enables rapid recovery of liver synthetic and metabolic functions, the recovery of physical capacity and performance to normal levels is delayed and often incomplete. Anatomic measurements of sarcopenia and the physical performance indicators of frailty both tend to improve slowly, and they may, in fact, decrease further in the posttransplant period, especially when the common extrahepatic drivers of muscle loss, such as the elements of the metabolic syndrome, persist or intensify after transplantation. Posttransplant exercise improves fitness, which is a conclusion based on 2 observational studies and 3 randomized trials that assessed endpoints of strength testing, energy expenditure in metabolic equivalents, and peak or maximal oxygen uptake. Importantly, 1 controlled trial found that exercise also improved quality of life (QOL) measured by the Short Form 36 survey, consistent with multiple reports of the value of social support and engagement in sports activity for improving posttransplant QOL. Developing evidence‐based standards for post–liver transplant physical activity baseline testing and sustainment of intensity and quality is a key unmet need in transplant hepatology. At present, it is reasonable for transplant teams to assess fitness and design a tailored exercise program when a recipient is first discharged, to record and reinforce progress at all posttransplant visits, and to set realistic longterm performance goals that will often achieve recommended standards for the healthy general population.
Frailty is associated with mortality in patients with cirrhosis. We measured frailty using 3 simple tests and calculated Liver Frailty Index (LFI) scores for patients at multiple ambulatory centers. ...We investigated associations between LFI scores, ascites, and hepatic encephalopathy (HE) and mortality.
Adults without hepatocellular carcinoma who were on the liver transplantation waitlist at 9 centers in the United States (N = 1044) were evaluated using the LFI; LFI scores of at least 4.5 indicated that patients were frail. We performed logistic regression analyses to assess associations between frailty and ascites or HE and competing risk regression analyses (with liver transplantation as the competing risk) to estimate sub-hazard ratios (sHRs) of waitlist mortality (death or removal from the waitlist).
Of study subjects, 36% had ascites, 41% had HE, and 25% were frail. The odds of frailty were higher for patients with ascites (adjusted odd ratio 1.56, 95% confidence interval CI 1.15–2.14) or HE (odd ratio 2.45, 95% CI 1.80–3.33) than for those without these features. Larger proportions of frail patients with ascites (29%) or HE (30%) died while on the waitlist compared with patients who were not frail (17% of patients with ascites and 20% with HE). In univariable analysis, ascites (sHR 1.52, 95% CI 1.14–2.05), HE (sHR 1.84, 95% CI 1.38–2.45), and frailty (sHR 2.38, 95% CI 1.77–3.20) were associated with waitlist mortality. In adjusted models, only frailty remained significantly associated with waitlist mortality (sHR 1.82, 95% CI 1.31–2.52); ascites and HE were not.
Frailty is a prevalent complication of cirrhosis that is observed more frequently in patients with ascites or HE and independently associated with waitlist mortality. LFI scores can be used to objectively quantify risk of death related to frailty—in excess of liver disease severity—in patients with cirrhosis.
•Beached marine debris has been found in the Southern Ocean for over three decades.•Plastic is the most commonly recovered item.•10,112 items weighing over 100 kg were recovered from Bird Island, ...South Georgia.•1304 items weighing 268 kg were recovered from Signy Island, South Orkneys.•Routine monitoring is essential to catalogue and identify trends in marine debris.
We report on three decades of repeat surveys of beached marine debris at two locations in the Scotia Sea, in the Southwest Atlantic sector of the Southern Ocean. Between October 1989 and March 2019 10,112 items of beached debris were recovered from Main Bay, Bird Island, South Georgia in the northern Scotia Sea. The total mass of items (data from 1996 onwards) was 101 kg. Plastic was the most commonly recovered item (97.5% by number; 89% by mass) with the remainder made up of fabric, glass, metal, paper and rubber. Mean mass per item was 0.01 kg and the rate of accumulation was 100 items km−1 month−1. Analyses showed an increase in the number of debris items recovered (5.7 per year) but a decline in mean mass per item, suggesting a trend towards more, smaller items of debris at Bird Island. At Signy Island, South Orkney Islands, located in the southern Scotia Sea and within the Antarctic Treaty area, debris items were collected from three beaches, during the austral summer only, between 1991 and 2019. In total 1304 items with a mass of 268 kg were recovered. Plastic items contributed 84% by number and 80% by mass, with the remainder made up of metal (6% by number; 14% by mass), rubber (4% by number; 3% by mass), fabric, glass and paper (<1% by number; 3% by mass). Mean mass per item was 0.2 kg and rate of accumulation was 3 items km−1 month−1. Accumulation rates were an order of magnitude higher on the western (windward) side of the island (13–17 items km−1 month−1) than the eastern side (1.5 items km−1 month−1). Analyses showed a slight decline in number and slight increase in mean mass of debris items over time at Signy Island. This study highlights the prevalence of anthropogenic marine debris (particularly plastic) in the Southern Ocean. It shows the importance of long-term monitoring efforts in attempting to catalogue marine debris and identify trends, and serves warning of the urgent need for a wider understanding of the extent of marine debris across the whole of the Southern Ocean.
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