Higher plants synthesize an amazing diversity of phenolic secondary metabolites. Phenolics are defined secondary metabolites or natural products because, originally, they were considered not essential for plant growth and development. Plant phenolics, like other natural compounds, provide the plant with specific adaptations to changing environmental conditions and, therefore, they are essential for plant defense mechanisms. Plant defensive traits are costly for plants due to the energy drain from growth toward defensive metabolite production. Being limited with environmental resources, plants have to decide how allocate these resources to various competing functions. This decision brings about trade-offs, i.e., promoting some functions by neglecting others as an inverse relationship. Many studies have been carried out in order to link an evaluation of plant performance (in terms of growth rate) with levels of defense-related metabolites. Available results suggest that environmental stresses and stress-induced phenolics could be linked by a transduction pathway that involves: (i) the proline redox cycle; (ii) the stimulated oxidative pentose phosphate pathway; and, in turn, (iii) the reduced growth of plant tissues.

Liver transplantation (LTx) is the best treatment for hepatocellular carcinoma (HCC), but should be offered only to selected patients. The usual procedure is to transplant only for small and unilobular tumors. The aim of this paper is to verify whether the actual indication criteria are still justified. The details of 121 patients with HCC who were submitted to LTx from 1985 to 2000 were analyzed. Age, gender, liver disease, Child class, a-fetoprotein (AFP) level, presence of tumor capsule, vascular invasion, size and number of nodules, histological grade, and pTNM were considered. The 5-and 10-year actuarial survival rates were 61.7% and 53.1%. Freedom from recurrence was 85.9% and 85.9%, respectively. At univariate analysis, size, presence of capsule, AFP levels, vascular invasion, grade, pTNM, transarterial chemoembolization (TACE), Child class, and age were all significantly related to survival and/or cancer recurrence. Presence of capsule, AFP levels, and viral cirrhosis were independent variables in Cox's analysis for survival, whereas histological grade, AFP levels, and vascular invasion were significant independent variables for recurrence. In conclusion, a strict selection should be made to optimize graft allocation while size and multifocality should probably no longer be considered a contraindication for LTx. Histological grade, AFP levels, and vascular invasion, as indicator of tumor behavior, more likely reflect the risk of recurrence.

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Between January 1989 and June 1997, 533 patients (423 male, 110 female, mean age 61 years, range 22-89 years) with hepatocellular carcinoma (HCC) were observed at our center. We report on 419 patients retrospectively compared for different treatments: liver transplantation (LT; 55 patients), resective surgery (RS; 41 patients), transarterial chemoembolization (TACE; 171 patients) and percutaneous ethanol injection (PEI; 152 patients). The 3- and 5-year actuarial survival rates were, respectively, 72% and 68% for LT, 64 and 44% for RS, 54 and 36% for PEI, and 32 and 22% for TACE. Survival curves were compared for sex, age, tumor characteristics, alphafetoprotein level, Child class, and etiology of cirrhosis. All patient-related characteristics examined (sex, age) are not significantly related to patient survival. Tumor-related variables and associated liver disease variables significantly conditioned survival in relation to different treatments. LT seems to be the treatment of choice for monofocal HCC less then 5 cm in diameter and in selected cases of plurifocal HCC.