Zinc is an essential trace element, exerting important antioxidant, anti-inflammatory, and antiapoptotic effects. It affects growth and development and participates in processes such as aging and cancer induction. The liver is important for the regulation of zinc homeostasis, while zinc is necessary for proper liver function. Decreased zinc levels have been implicated in both acute and chronic liver disease states, and zinc deficiency has been implicated in the pathogenesis of liver diseases. Zinc supplementation offers protection in experimental animal models of acute and chronic liver injury, but these hepatoprotective properties have not been fully elucidated. In the present review, data on zinc homeostasis, its implication in the pathogenesis of liver diseases, and its effect on acute and chronic liver diseases are presented. It is concluded that zinc could protect against liver diseases, although up to now the underlying pathophysiology of zinc and liver interactions have not been defined.

Hydatid disease is endemic in Greece, and has been known from Hippocrates' time to cause cysts in the liver. We report here three very rare cases of primary gallbladder hydatid disease without prior history or evidence of concurrent disease activity in any other location. To our knowledge, only two previous reports exist, each of one patient suffering from primary gallbladder hydatid disease. Unlike the insidious hydatid cysts of the liver, gallbladder hydatidosis in our patients was associated with early diagnosis, due to gallbladder dysfunction symptoms presenting early in its course. Moreover, the size of gallbladder cysts compared to liver cysts at diagnosis was small (maximal diameter, <5 cm), making total cyst excision along with cholecystectomy feasible for all of our patients. During long-term follow up of the patients (up to 10 years), no disease recurrences were noted. We provide supporting evidence that primary gallbladder hydatidosis presents a different pathophysiological and clinical course, having better prognosis, when compared with the usual liver disease.

Platelet-activating factor (PAF) is a potent lipid inflammatory mediator acting on cells through its specific receptor. Plasma PAF-acetylhydrolase (PAF-AH) is the main enzyme that inactivates PAF in blood, participating in its homeostasis. The objective of this study was to investigate the involvement of PAF in the liver fibrotic process using an experimental animal model. Liver fibrosis was induced in adult male Wistar rats by administration of thioacetamide (TAA) in drinking water (300 mg/l) for three months. The animals were sacrificed at time 0 (control group) and after 1, 2, and 3 months. PAF levels in liver and blood and PAF-AH activity in plasma were determined. Liver histopathological examination was also performed. TAA administration resulted in progressively increased liver fibrosis, leading finally to the formation of cirrhotic nodules in the liver. Throughout the experiment PAF levels in liver tissue remained stable. "Total" ("free" plus "bound") PAF levels in blood decreased, reaching statistically significant differences in the first and third months compared with the control group (P < 0.05). "Free" PAF levels in blood were higher at one month (P < 0.05) and decreased gradually thereafter. In all treated groups, "bound" PAF levels in blood decreased whereas plasma PAF-AH activity increased (P < 0.05) compared with the control group. Our data indicated alterations of PAF levels in blood and PAF-AH activity during fibrosis induction, implicating participation of PAF in the liver fibrotic process.

Line drawing and screentoning are two distinct areas of study in non-photorealistic rendering, where the former emphasizes object contours, while the latter conveys tone and shading information on object surfaces. As these two problems are concerned with different yet equally important features, either method seldom delivers a complete description of the scene when used alone. Yet, research community has largely treated them as separate problems and thus resulted in two entirely different sets of solutions, complicating both implementation and usage. In this paper, we present a stylistic image binarization method called hybrid difference of Gaussians (HDoG) that performs both line drawing and screentoning in a unified framework. Our method is based upon two different extensions of DoG operator: one for line extraction, and the other for tone description. In particular, we propose an extension called adaptive DoG, that uses luminance as weight to automatically generate screentone that adapts to the local tone. Experimental results demonstrate that our hybrid method effectively generates aesthetically pleasing image binarizations that encompass both line drawing and screentoning, closely resembling professional pen-and-ink illustrations. Also, being based on Gaussian filtering, our method is very fast and also easy to implement.