In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

Context: Most hepatocellular carcinomas (HCCs) are associated with cirrhosis. Portal hypertension (PHT) and esophageal variceal bleeding (EVB) can limit the patient's treatment options. Surgical therapy in such patients is challenging. We performed devascularization plus liver resection or radiofrequency ablation (RFA) to treat HCC patients with concomitant EVB resulting from PHT secondary to cirrhosis. Such combined operations have never been reported for the management of HCC patients with variceal esophageal bleeding.", 'To evaluate two different treatment regimens for patients with HCC and EVB.', 'We evaluated 35 BCLC stage 0/A patients with HCC and EVB who underwent either devascularization plus liver resection (Group A) or devascularization plus RFA (Group B). We reviewed the safety and outcomes of the two groups and assessed risk factors for patient survival and tumor recurrence.', 'Significant factors for overall survival were surgical approach and Child-Pugh classification. Child-Pugh classification was the only independent risk factor for overall postoperative survival [hazard ratio (HR) 8.320, 95 % confidence interval (CI) 1.739-39.799, P = 0.008]. Age was the only independent risk factor for tumor recurrence (HR 4.025, 95 % CI 1.343-12.062, P = 0.013).\Question: Is radiofrequency ablation plus devascularization the preferred treatment of hepatocellular carcinoma with esophageal varices?
RFA plus devascularization is the preferred treatment of HCC with EVB. RFA plus devascularization should be considered in Child-Pugh class A patients below 50 years of age.

Context: To investigate the effects of copper on permeability and P-glycoprotein (P-gp) of Caco-2 cell monolayers.', 'The differentiated Caco-2 cell model was used in this study. Permeability of cell monolayers was reflected by monitoring transepithelial electrical resistance (TEER); distribution of tight junctional protein ZO-1 was measured by immunofluorescent staining; F actin was measured by fluorescence staining; and Activity of P-gp was reflected by changes of transcellular transport and accumulation of Rho-123 in Caco-2 cells.', "Apical treatment with copper (30 - 100 micromol/L, Hanks' buffered salt solution, up to 3 hours) induced a time- and concentration-dependent increase in permeability reflected by progressive decrease of TEER of Caco-2 cell monolayers, accompanied by deorganization of F actin, but without significant effects on tight junctional protein ZO-1; at a dose without any adverse effects on viability and permeability of Caco-2 monolayers, copper treatment (300 micromol/L, complete medium, 24 hours) decreased Papp(BL-->AP) from 7.37 +/- 0.20 x 10(-6) cm/s (controls) to (6.43 +/- 0.27) x 10(-6) cm/s, the increased Papp(AP-->BL) from (1.23 +/- 0.05) x 10(-7) cm/s (controls) to (3.41 +/- 0.08) x 10(-7) cm/s, and enhanced the intracellular Rho-123 from (0.31 +/- 0.01) nmol/filter (controls) to (0.50 +/- 0.03) nmol/filter.\Question: Does [ Copper treatment alter the barrier functions of human intestinal Caco-2 cells ]?
Copper might alter the barrier functions of Caco-2 cells through increasing the permeability and inhibiting P-gp of Caco-2 cells.

Context: Environmental conditions (eg, latitude) play a critical role in the susceptibility and severity of many autoimmune disorders, including multiple sclerosis (MS). Here, we investigated the mechanisms underlying the beneficial effects of immune regulatory processes induced in the skin by moderate ultraviolet B (UVB) radiation on central nervous system (CNS) autoimmunity.', 'Effects of UVB light were analyzed in a murine model of CNS autoimmunity (experimental autoimmune encephalomyelitis). Additionally, patients with relapsing-remitting MS were treated with narrowband UVB phototherapy. Immunomodulatory effects were examined in skin biopsies, serum samples, and immune cells of the peripheral blood.', 'Regulatory T cells (Tregs), which are induced locally in the skin-draining lymph nodes in response to UVB exposure, connect the cutaneous immune response to CNS immunity by migration to the sites of inflammation (blood, spleen, CNS). Here, they attenuate the inflammatory response and ameliorate disease symptoms. Treg-inducing tolerogenic dendritic cells (DCs) were further necessary for induction of this systemic immune regulation by UVB radiation, because ablation of Langerhans cells abolished the UVB-induced phenotype. MS patients treated with UVB phototherapy showed an increase in induced Tregs and tolerogenic DCs accompanied by the downregulation of the T-cell effector cytokine interleukin 21. The treatment further induced elevated serum levels of vitamin D.\Question: Does ultraviolet B light attenuate the systemic immune response in central nervous system autoimmunity?

Local UVB radiation of the skin influences systemic immune reactions and attenuates systemic autoimmunity via the induction of skin-derived tolerogenic DCs and Tregs. Our data could have implications for the understanding or therapeutic modulation of environmental factors that influence immune tolerance.