A novel multidrug-resistance protein 2 gene mutation identifies a subgroup of patients with primary biliary cirrhosis and pruritus

A single nucleotide polymorphism characterized by the substitution of valine for glutamate (V1188E) in exon 25 of the multidrug resistance protein 2 gene was found in a group of patients with primary biliary cirrhosis. This heterozygous mutation was significantly associated with the presence of pruritus.     

MTHFR C677T Polymorphism and Risk of HCC in Patients With Liver Cirrhosis: Role of Male Gender and Alcohol Consumption

Background:  A single nucleotide polymorphism (SNP) C677T in the methylenetetrahydrofolate reductase (MTHFR) gene has been identified. The TT or CT genotypes show a marked reduction of the enzyme activity; this causes higher homocysteine levels and alterations of folate metabolism. Folate metabolism is essential for DNA synthesis and methylation, crucial steps in carcinogenesis. In this paper, we investigated whether the MTHFR C677T SNP could influence the occurrence of hepatocellular carcinoma (HCC) in a cohort of patients transplanted for end stage liver disease of different etiologies.
Methods:  Two hundred and twelve consecutive patients who underwent liver transplantation for end stage liver disease due to hepatitis B or C, alcoholic liver disease, and other causes were studied. Two hundred and thirty-six blood donors served as controls. Focal hepatic lesions were searched in the sectioned explanted livers. The presence of the MTHFR C677T SNP was determined via polymerase chain reaction amplification.
Results:  Among the 65 patients with HCC, 22 had the CC genotype, 30 the CT, and 13 the TT genotype. Only in patients with alcoholic liver disease was a significant association detected between the TT genotype and the presence of liver cancer (6/17 vs. 5/46, p  < 0.05). At stepwise logistic regression analysis the independent selected predictors of HCC were found: age at transplantation >55 years ( p  < 0.001) and the association among male gender, alcoholic liver disease, and MTHFR TT genotype ( p  = 0.002).
Conclusions:  The present study suggests that male TT carriers with alcoholic cirrhosis bear an increased risk of developing HCC.     

Mutational Analysis of Human BLyS in Patients with Common Variable Immunodeficiency

BLyS, a TNF family member, is crucial for B cell proliferation and differentiation by acting through its three receptors, TACI, BCMA and BAFF-R. The knock out model for BLyS is characterized by an immunological phenotype reminiscent of the human phenotype of common variable immunodeficiency (CVID). CVID is characterized by a defective B cell compartment, evidencing the putative importance of BLyS in its pathogenesis. On the contrary, the transgenic model for BLys is characterized by autoimmune manifestations, underlying its role in B cell regulation. In fact, mutations in TACI, one of the three BLyS receptors, are associated with CVID. Based on these facts, we hypothesized that BLyS could be a candidate gene for CVID. We screened 78 patients with CVID using DHPLC and direct sequencing: No disease causing mutations were identified. A novel heterozygous single nucleotide polymorphism (SNP) was found in exon 1 of one individual, however this SNP (G189A) does not lead to an amino acid substitution.     

Cell renewing in neuroblastoma: electrophysiological and immunocytochemical characterization of stem cells and derivatives

We explored the stem cell compartment of the SH-SY5Y neuroblastoma (NB) clone and its development by a novel approach, integrating clonal and immunocytochemical investigations with patch-clamp measurements of ion currents simultaneously expressed on single cells. The currents selected were the triad IHERG, IKDR, INa, normally expressed at varying mutual ratios during development of neural crest stem cells, from which NB derives upon neoplastic transformation. These ratios could be used as electrophysiological clusters of differentiation (ECDs), identifying otherwise indistinguishable stages in maturation. Subcloning procedures allowed the isolation of highly clonogenic substrate-adherent (S-type) cells that proved to be p75- and nestinpositive and were characterized by a nude electrophysiological profile (ECDS0). These cells expressed negligible levels of the triad and manifested the capacity of generating the two following lineages: first, a terminally differentiating, smooth muscular lineage, positive for calponin and smooth muscle actin, whose electrophysiological profile is characterized by a progressive diminution of IHERG, the increase of IKDR and INa, and the acquisition of IKIR (ECDS2); second, a neuronal abortive pathway (NF-68 positive), characterized by a variable expression of IHERG and IKDR and a low expression of INa (ECDNS). This population manifested a vigorous amplification, monopolizing the stem cell compartment at the expense of the smooth muscular lineage to such an extent that neuronal-like (N-type) cells must be continuously removed if the latter are to develop.     

The telomere-telomerase axis and the heart

The preservation of myocyte number and cardiac mass throughout life is dependent on the balance between cell death and cell division. Rapidly emerging evidence indicates that new myocytes can be formed through the activation and differentiation of resident cardiac progenitor cells. The critical issue is the identification of mechanisms that define the aging of cardiac progenitor cells and, ultimately, their inability to replace dying myocytes. The most reliable marker of cellular senescence is the modification of the telomere-telomerase axis, together with the expression of the cell cycle inhibitors p16INK4a and p53. Cellular senescence is characterized by biochemical events that occur within the cell. In this regard, one of the most relevant processes is represented by repeated oxidative stress that may evolve into the activation of the cell death program or result in the development of a senescent phenotype. Thus, the modulation of telomerase activity and the control of telomeric length, together with the attenuation of the formation of reactive oxygen species, may represent important therapeutic tools in regenerative medicine and in prevention of aging and diabetic cardiomyopathies.     

Prospective Study on CVID Patients with Adverse Reactions to Intravenous or Subcutaneous IgG Administration

Introduction The multicenter prospective study provides information on adverse reactions to intravenous and subcutaneous immunoglobulin treatment in a cohort of 262 patients with common variable immunodeficiency. Severe adverse reactions are a rare but unpredictable event that might occur also in patients who tolerate substitutive intravenous or subcutaneous immunoglobulin therapy for months or years. Results Subcutaneous therapy has been proved to be a safe option in the 13 patients who had to stop intravenous treatment and who remained out of immunoglobulin replacement for long periods of time. However, severe reactions to subcutaneous therapy occurred at the first or after several subcutaneous immunoglobulin administrations in 2 out of 13 patients. Conclusion Therefore, patients with previous severe reactions to intravenous immunoglobulin should be considered at particularly high risk for reaction to subcutaneous administration. In these cases, switching from in-hospital administration to home self-administration should be done with extreme care.     

Inverse association between dietary vitamin D and risk of cutaneous melanoma in a northern Italy population

The possibility of an inverse association between vitamin D and risk of cancer and, in particular, of cutaneous malignant melanoma has been suggested, but results of epidemiologic studies are still conflicting. We examined the relation between dietary vitamin D intake and melanoma risk through a population-based case-control study (380 cases, 719 controls) in a northern region of Italy, a country with an average vitamin D intake lower than that in northern Europe or the United States. We assessed average daily intake of vitamin D from foodstuffs using the European Prospective Investigation into Cancer and Nutrition (EPIC) semiquantitative food frequency questionnaire. In this population, levels of vitamin D intake were considerably lower than those observed in recent U.S. studies. We found an inverse relation between dietary vitamin D and melanoma risk in the sample as a whole, in both crude and adjusted analyses. In sex- and age-specific analyses, this association appeared to be stronger among males and among older subjects. These findings suggest that, at the relatively low levels of intake observed in this sample, an inverse relation between dietary vitamin D and risk of cutaneous malignant melanoma may exist.     

Genetic polymorphisms of inflammatory cytokines and liver fibrosis progression due to recurrent hepatitis C.

To ascertain whether single nucleotide polymorphisms (SNPs) regulating the expression of interferon-gamma (IFN-gamma), IFN-gamma receptor-1 (IFNGR-1), interleukin-6 (IL-6), IL-10, IL-18, and tumor necrosis factor-alpha (TNF-alpha) may be associated with early fibrosis progression of recurrent hepatitis C, 50 liver transplantation recipients (32 men, 18 women, median age 56 years) with a median histologic follow-up time of 54 months were studied; 98 healthy blood donors served as controls. Cytokine SNPs were determined by means of previously described PCR-based methods. On the basis of the SNP studies, a low, intermediate, or high producer cytokine phenotype was attributed to each patient. Only 1 of the 17 low IL-10 producers reached an Ishak staging score > 2, in contrast to 20 of the 33 patients who were intermediate or high IL-10 producers (Mantel-Cox, p < 0.005). Recipients who were low IL-10 producers and high IFN-gamma producers had significantly slower fibrosis progression in comparison to intermediate/high IL-10 producers and low IFN-gamma producers (p < 0.005). In conclusion, cytokine SNPs resulting in high and low producer phenotypes of both Th1 and Th2 cytokines appear to modulate the course of recurrent hepatitis C. Low IL-10 producers are those with the slowest histologic fibrosis progression.