5,548 research outputs found
Role of insulin dysregulation in the development of yoshida sarcoma-induced cancer cachexia
No full textCancer cachexia is a devastating syndrome present in many individuals with cancer. Characterized by weight loss, loss of appetite, and wasting of skeletal muscle and adipose tissue, cachexia is associated with an increase in both morbidity and mortality in this population. The majority of individuals with cancer will experience some degree of cachexia during the course of their disease, making cachexia a clinically relevant syndrome for which the contributing mechanisms are largely unknown. A decline in insulin function, as measured by reduced glucose tolerance and insulin sensitivity, is common in individuals with and animal models of cancer cachexia. The present series of experiments was designed to examine the role of this insulin dysregulation in the development of cancer cachexia in rats bearing the Yoshida sarcoma. In experiment 1, insulin sensitivity was measured during the tumor growth period to determine when insulin dysregulation begins, relative to changes in body composition associated with cancer cachexia (Chapter 2). In Experiment 2, control and tumor-bearing animals were treated daily with saline or Exnedin-4, a GLP-1 agonist, in order to determine whether cachexia could be prevented by improving insulin sensitivity (Chapter 3). In Experiment 3, animals were fed a chow diet or a high-fat diet prior to tumor implantation, to determine if diet-induced insulin resistance modifies the development of cachexia in rats bearing the Yoshida sarcoma (Chapter 4). Our results indicate that 1) insulin dysregulation is present in Yoshida sarcoma-bearing rats prior to the onset of cachexia, 2) prevention of insulin dysregulation via chronic Exendin-4 treatment prevents the development of some cancer cachexia symptoms, and 3) the induction of insulin dysregulation via high-fat diet feeding accelerates the development of cancer cachexia. Further research is necessary to determine the mechanisms through which insulin dysregulation develops, as alterations in insulin signaling do not appear to contribute significantly to the observed effects
Endocrine effects of a low-carbohydrate, high-fat ketogenic diet
No full textLow-carbohydrate, high-fat ketogenic diets (KD) have become popular in recent years and are often used in an effort to control body weight. Our laboratory examines how maintenance on a ketogenic diet affects the multiple peripheral and central neuroendocrine systems involved in the regulation of energy balance in rats. We have previously observed increases in epididymal fat pad weight, and plasma leptin and ghrelin concentrations, as well as decreases in plasma insulin concentrations following a 7-week KD. The present series of experiments explored the development of changes in plasma endocrine hormone profiles over the course of an 8-week KD and the endocrine effects of returning to a chow diet (CH) following 8 weeks of KD consumption. Rats were maintained on CH or KD and sacrificed after 1, 4, or 8 weeks of diet maintenance (Experiment 1). We found significant increases in epididymal fat pad weight only after the full duration of KD maintenance. Plasma leptin levels were also elevated in KD rats. Contrary to previous studies, the present experiment did not observe alterations in plasma insulin or ghrelin levels. In Experiment 2, rats were maintained on CH or KD for a total of 8 weeks. Following this time, KD rats were switched to consuming CH and sacrificed after 1, 4, or 8 weeks of CH feeding (9, 12, and 16 total weeks). Results were compared to data collected after 8 weeks of maintenance on the original assigned diet. We observed increases in caloric intake and plasma insulin concentrations following the switch from KD to CH, starting at weeks 14 and 16, respectively. Epididymal fat pad weights and plasma leptin concentrations remained at levels exhibited at the end of KD maintenance following the diet switch. The present series of experiments demonstrates the ability of KD to produce alterations in plasma endocrine hormones not only during diet maintenance, but also following the switch to an alternative diet
The time to change lanes: a literature review. Interim report
No full textUniversity of Michigan, Ann Arbor, Intelligent Vehicle Highway Systems Programhttp://deepblue.lib.umich.edu/bitstream/2027.42/894/2/80190.0001.001.pd
Open access self-archiving: An author study
No full textThis, our second author international, cross-disciplinary study on open access had 1296 respondents. Its focus was on self-archiving. Almost half (49%) of the respondent population have self-archived at least one article during the last three years. Use of institutional repositories for this purpose has doubled and usage has increased by almost 60% for subject-based repositories. Self-archiving activity is greatest amongst those who publish the largest number of papers. There is still a substantial proportion of authors unaware of the possibility of providing open access to their work by self-archiving. Of the authors who have not yet self-archived any articles, 71% remain unaware of the option. With 49% of the author population having self-archived in some way, this means that 36% of the total author population (71% of the remaining 51%), has not yet been appraised of this way of providing open access. Authors have frequently expressed reluctance to self-archive because of the perceived time required and possible technical difficulties in carrying out this activity, yet findings here show that only 20% of authors found some degree of difficulty with the first act of depositing an article in a repository, and that this dropped to 9% for subsequent deposits. Another author worry is about infringing agreed copyright agreements with publishers, yet only 10% of authors currently know of the SHERPA/RoMEO list of publisher permissions policies with respect to self-archiving, where clear guidance as to what a publisher permits is provided. Where it is not known if permission is required, however, authors are not seeking it and are self-archiving without it. Communicating their results to peers remains the primary reason for scholars publishing their work; in other words,
researchers publish to have an impact on their field. The vast majority of authors (81%) would willingly comply with a mandate from their employer or research funder to deposit copies of their articles in an institutional or subject-based repository. A further 13% would comply reluctantly; 5% would not comply with such a mandate
Resilience and regime shifts: Assessing cascading effects
No full textMost accounts of thresholds between alternate regimes involve a single, dominant shift defined by one, often slowly changing variable in an ecosystem. This paper expands the focus to include similar dynamics in social and economic systems, in which multiple variables may act together in ways that produce interacting regime shifts in social-ecological systems. We use four different regions in the world, each of which contains multiple thresholds, to develop a proposed general model of threshold interactions in social-ecological systems. The model identifies patch-scale ecological thresholds, farm- or landscape-scale economic thresholds, and regional-scale sociocultural thresholds. Cascading thresholds, i.e., the tendency of the crossing of one threshold to induce the crossing of other thresholds, often lead to very resilient, although often less desirable, alternative states
Treebank-3
No full textThe Penn Treebank (PTB) project selected 2,499 stories from a three year Wall Street Journal (WSJ) collection of 98,732 stories for syntactic annotation. These 2,499 stories have been distributed in both Treebank-2 (LDC1999T42) and Treebank-3 (LDC1999T42) releases of PTB
The author is dead, long live the author
No full textThe death of the author has been greatly exaggerated. Readers still seek what Virginia Woolf called the shadowy figure of the author in the pages of their books
Review of eye fixation recording methods and equipment. Final report
No full textNotes: Report covers the period Sept 1991 - Oct 1992University of Michigan, Ann Arbor, IVHS Industrial Advisory Boardhttp://deepblue.lib.umich.edu/bitstream/2027.42/975/2/84771.0001.001.pd
Genome-wide association study identifies a variant in HDAC9 associated with large vessel ischemic stroke
No full textGenetic factors have been implicated in stroke risk, but few replicated associations have been reported. We conducted a genome-wide association study (GWAS) for ischemic stroke and its subtypes in 3,548 affected individuals and 5,972 controls, all of European ancestry. Replication of potential signals was performed in 5,859 affected individuals and 6,281 controls. We replicated previous associations for cardioembolic stroke near PITX2 and ZFHX3 and for large vessel stroke at a 9p21 locus. We identified a new association for large vessel stroke within HDAC9 (encoding histone deacetylase 9) on chromosome 7p21.1 (including further replication in an additional 735 affected individuals and 28,583 controls) (rs11984041; combined P = 1.87 × 10<sup>−11</sup>; odds ratio (OR) = 1.42, 95% confidence interval (CI) = 1.28–1.57). All four loci exhibited evidence for heterogeneity of effect across the stroke subtypes, with some and possibly all affecting risk for only one subtype. This suggests distinct genetic architectures for different stroke subtypes
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