Non-alcoholic fatty liver disease (NAFLD) is currently conceptualised as a clinical spectrum that results from a ‘multiple-hit’ process which begins with simple steatosis and subsequently renders the ...hepatocytes susceptible to a variety of insults. Ultimately, more serious liver injuries like non-alcoholic steatohepatitis (NASH) and cirrhosis may develop. Although the metabolic syndrome is considered the crucial player in the pathogenesis of NAFLD, recent studies have highlighted novel pathophysiological mechanisms in this clinical entity.
To discuss the pathophysiology of NAFLD based on the hypothesis that simple steatosis and NASH are discrete entities rather than two points on a spectrum.
A literature search was conducted in August 2012 on PubMed, Ovid Embase, Ovid Medline and Scopus using the following search terms: steatosis, non-alcoholic steatohepatitis, pathophysiology, fatty liver, natural history and genetics.
Simple steatosis and NASH appear as two distinct pathophysiological entities and progression from pure fatty liver to NASH appears to be so rare as to warrant publication. The possible pathogenetic pathways specifically related to NASH are highlighted.
Although simple steatosis and non-alcoholic steatohepatitis are currently viewed as two histological subtypes of the unique spectrum of non-alcoholic fatty liver disease, the two conditions are likely distinct not only from a histological but also from a pathophysiological standpoint. Efforts to distinguish simple steatosis from non-alcoholic steatohepatitis using non-invasive modalities should be informed by the current pathophysiology of these two clinical entities.
An experimental program was undertaken to investigate the effects of discrete polypropylene fibers and Class C fly ash on the stress–strain and shear strength behavior of clayey soil. Two types of ...fiber (fibrillated polypropylene fiber and multifilament polypropylene fiber) in two different lengths (6.0mm and 19.0mm) and two fiber dosages (i.e. 0.5% and 1.0% by dry weight of soil) were considered. At first, compaction characteristics of the untreated soil and seven different fly ash–soil mixtures (2.5%, 5.0%, 7.5%, 10.0%, 15.0%, 20.0%, and 30.0% by dry weight of soil) were evaluated at standard compaction energy. Considering compaction characteristics, unconfined compression tests of untreated soil and five different fly ash–soil mixtures (5.0%, 10.0%, 15.0%, 20.0%, and 30.0% by dry weight of soil) were carried out after 1-, 7-, 14-, 28- and 90-day curing periods. According to the obtained test results, untreated soil and two different fly ash–soil mixtures (i.e. 10.0, and 30.0% by dry weight of soil) were mixed with fibrillated polypropylene fiber and multifilament polypropylene fiber in two different lengths and in two different fiber dosages, separately. A total of 17 different fiber–fly ash–soil mixtures were composed, and their unconfined compression tests were carried out after 28-day curing period. According to unconfined compression test results, 6 different fiber–fly ash–soil mixtures were selected for UU triaxial tests at the end of 28-day curing period. The obtained test results indicated that the effect of fly ash content on the stress–strain behavior is superior to the effect of fibers. The post-peak strength behavior is strongly affected by fiber type, length and dosage. The magnitude of the effect increases as the fly ash content increases. Inclusion of fiber alone without fly ash decreases unconfined compressive strength (UCS) of the compacted fiber–clay mixtures. On the other hand, when combined with fly ash, fiber inclusion increases UCS depending on fiber type, length and dosage. Moreover, for both fiber types and fiber lengths, the higher the dosage of fiber, the higher the UCS is. The increase in UCS becomes as much as 218% for 30% fly ash content and 1.0% 19mm long fibrillated polypropylene fiber.
•Fiber alone decreases unconfined compressive strength (UCS).•Fly ash and fiber increase UCS depending on fiber type, length and dosage.•Fiber type, length and dosage strongly affect the post-peak strength behavior.•For the fly ash content beyond 10.0%, the failure pattern changes from ductile to brittle.•Long term curing up to 90days significantly increases UCS of the mixtures.
Summary
Background
Low bone mineral density (BMD) has been reported in both paediatric and adult patients with non‐alcoholic fatty liver disease (NAFLD). The mechanisms behind the reduced BMD in ...NAFLD are still not completely understood.
Aim
To provide a critical overview of the pathophysiological pathways linking NAFLD, reduced BMD and osteoporosis, with a special focus on the alterations of soluble mediators which could link fat accumulation in the liver with bone health. The MEDLINE database was searched by a combination of keywords: non‐alcoholic fatty liver disease OR hepatic steatosis OR metabolic syndrome OR insulin resistance AND bone mineral density OR osteoporosis OR bone AND biomarkers OR serum marker.
Results
Several factors that may influence bone mineralisation and the increased risk of osteoporosis in NAFLD can be discussed. These include the release of cytokines from the inflamed liver which may influence the bone microenvironment, vitamin D deficiency, and limited physical activity. Circulating markers of bone metabolism, including osteopontin, osteoprotegerin, osteocalcin and fetuin‐A, have been found to be altered in patients with NAFLD.
Conclusion
A better understanding of the mechanisms that link bone metabolism and the liver may open a new frontier to fight two highly prevalent conditions like NAFLD and osteoporosis.
Summary
Background Biomarkers hold great promise for detecting chronic liver disease without the use of liver biopsy.
Aim To review the usefulness of cytokeratin (CK) 18 fragments, a marker of ...hepatocyte apoptosis, to predict the presence of chronic liver injury.
Methods Available literature identified from PubMed was reviewed.
Results Levels of CK18 fragments have been shown to be elevated in hepatocellular carcinoma, viral hepatitis, alcoholic hepatitis, nonalcoholic fatty liver disease and cholestatic liver disease. In the setting of nonalcoholic fatty liver disease, CK18 fragments may distinguish nonalcoholic steatohepatitis from simple fatty liver.
Conclusions Undoubtedly, the most promising application of CK18 fragments is currently in nonalcoholic fatty liver disease, and especially for distinguishing patients with nonalcoholic steatohepatitis vs. those with simple steatosis. Further investigations and technical improvements are required to cross the boundary from research to the clinical application of CK18 fragments as a marker of chronic liver disease.
Summary
Background
The role of excess fructose intake in the pathogenesis of non‐alcoholic fatty liver disease (NAFLD) has recently received increasing attention, but the pathophysiology of this ...relationship has been only partly elucidated.
Aim
To provide an overview of the potential role played by fructose in the pathogenesis of NAFLD by focusing on both indirect and direct harmful effects.
Methods
Experimental and clinical studies which investigated the relation of fructose with NAFLD are reviewed.
Results
Several factors may potentially contribute to fructose‐induced NAFLD, including the induction of the metabolic syndrome, copper deficiency, bacterial translocation from the gut to the liver, the formation of advanced glycation endproducts and a direct dysmetabolic effect on liver enzymes.
Conclusions
Experimentally‐increased fructose intake recapitulates many of the pathophysiological characteristics of the metabolic syndrome in humans, which may in turn lead to NAFLD. However, the majority of experimental studies tend to involve feeding excessively high levels of fructose (60–70% of total energy intake) which is not reflective of average human intake. Hopefully, the combination of in vivo, in vitro and genetic research will provide substantial mechanistic evidence into the role of fructose in NAFLD development and its complications.
Summary
Background
Coffee consumption may modulate the risk of the metabolic syndrome (MetS) and non‐alcoholic fatty liver disease (NAFLD).
Aim
To review the experimental, epidemiological and ...clinical studies investigating the association between coffee consumption and the risk of MetS and NAFLD.
Methods
A literature search was conducted with the aim of finding original experimental, epidemiological and clinical articles on the association between coffee consumption, MetS and NAFLD. The following databases were used: PubMed, Embase, Scopus and Science Direct. We included articles written in English and published up to July 2013.
Results
Three experimental animal studies investigated the effects of coffee in the MetS, whereas five examined whether experimental coffee intake may modulate the risk of fatty liver infiltration. All of the animal studies showed a protective effect of coffee towards the development of MetS and NAFLD. Moreover, we identified eleven epidemiological and clinical studies that met the inclusion criteria. Of them, six were carried out on the risk of the MetS and five on the risk of NAFLD. Four of the six studies reported an inverse association between coffee consumption and the risk of MetS. The two studies showing negative results were from the same study cohort consisting of young persons with a low prevalence of the MetS. All of the epidemiological and clinical studies on NAFLD reported a protective effect of coffee intake.
Conclusions
Coffee intake can reduce the risk of NAFLD. Whether this effect may be mediated by certain components of the MetS deserves further investigation.
Introduction Selective serotonin reuptake inhibitors (SSRI group antidepressant drugs) are not significantly different from tricyclic antidepressants and other antidepressants in terms of efficacy, ...but provide significant advantages in terms of side effects and toxicity. One of the most important side effects of antidepressant drugs is weight gain. However, there is not yet enough study on weight gain mechanism. Nutrition and hunger-satiety circle are occured under the control of neuropeptids and hormones that are synthesized and secreted from the hypothalamic arcuate nucleus (ARC), adipose tissue and the pancreas. In this study, we examined how escitalopram affects the body weight, the body mass index, the serum lipid profile, the liver function tests, the underlying molecular mechanisms of weight change, the relationships these mechanizms and the hypotalamic nutrition regulatory neuropeptides such as POMC, NPY, leptin, CCK and insülin that is a pancreatic hormone. Objectives In order to understand the relationship between antidepressants and metabolic risk factors such as diabetes and obesity and to understand the underlying mechanisms, body weight, waist and hip circumference, POMC and NPY levels from hypothalamic nutrition regulating neuropeptides, CCK from peripheral neuropeptides, a pancreatic hormone insulin, and the effects of escitalopram use on these parameters were investigated. Methods In this prospective study, 30 patients, who were decided to have escitalopram treatment and who met the inclusion criteria and continued the treatment for 12 weeks, were included in the study. Results Weight, waist circumference increase and waist-hip ratio decreased significantly after 12 weeks. The decrease in neuropeptide level in POMC was significant. Conclusions In our study, according to the insignificant change in lipid parameters it was thought that the use of escitalopram does not cause a metabolic change that would increase the risk in terms of metabolic syndrome and cardiovascular disease, despite the short study period. The decrease in POMC levels due to escitalopram use; It was thought that it may lead to weight gain by modulating eating behavior modulation. Disclosure of Interest None Declared
Active Global Seismology Cemen, Ibrahim; Yilmaz, Yucel
2017, 2017-03-06, 2017-02-17, Letnik:
225
eBook
Neotectonics involves the study of the motions and deformations of the Earth's crust that are current or recent in geologic time. The Mediterranean region is one of the most important regions for ...neotectonics and related natural hazards. This volume focuses on the neotectonics of the Eastern Mediterranean region, which has experienced many major extensive earthquakes, including the devastating Izmit, Turkey earthquake on August 17, 1999. The event lasted for 37 seconds, killing around 17,000 people, injuring 44,000 people, and leaving approximately half a million people homeless. Since then, several North American, European, and Turkish research groups have studied the neotectonics and earthquake potential of the region using different geological and geophysical methods, including GPS studies, geodesy, and passive source seismology. Some results from their studies were presented in major North American and European geological meetings. This volume highlights the work involving the Eastern Mediterranean region, which has one of the world's longest and best studied active strike-slip (horizontal motion) faults: the east-west trending North Anatolian fault zone, which is very similar to the San Andreas fault in California. This volume features discussions of: Widespread applications in measuring plate motion that have strong implications in predicting natural disasters like earthquakes, both on a regional and a global scale Recent motions, particularly those produced by earthquakes, that provide insights on the physics of earthquake recurrence, the growth of mountains, orogenic movements, and seismic hazards Unique methodical approaches in collecting tectonophysical data, including field, seismic, experimental, computer-based, and theoretical approaches. Active Global Seismology is a valuable resource for geoscientists, particularly in the field of tectonophysics, geophysics, geodynamics, seismology, structural geology, environmental geology, and geoengineering. Read an interview with the editors to find out more: https://eos.org/editors-vox/neotectonics-and-earthquake-forecasting
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