[Molecular diversity of the gene encoding Fe(II)-oxidizing enzyme in Acidithiobacillus ferrooxidans].

Acidithiobacillus ferrooxidans (A.f) is a Gram-negative chemolithotrophic bacterium able to oxidize ferrous iron, elemental sulfur and inorganic sulfur compounds. Fe(II)-oxidizing enzyme plays key role in Fe(II)-oxidizing system. Different A.f strains, which were isolated and purified from various ecological niches, show obviously phenotypic diversity after comparison rates of growth and oxidation of Fe2+. The Fe(II)-oxidizing enzyme gene(iro) for five strains was identified by PCR reactions uitilising primers and genomic DNA, then sequenced and multialignment. The results show there is a putative high variable region in CDS between the 187th and 195th bp and the sequence similarities are from 97% to 99%. For strain YTW, P187-189 Thr-->Pro; For P193-195, Met-->Asn for strain TK; Met-->Ile for strain BY; For P219, all strains T-->C. For upstream of CDS, sequences of all strains are identical to the Genebank sequence (E03451), but downstream of CDS, the sequences exist some variable sites too.

Lipotoxic effect of p21 on free fatty acid-induced steatosis in L02 cells.

Nonalcoholic fatty liver disease (NAFLD) is increasingly regarded as a hepatic manifestation of metabolic syndrome. Though with high prevalence, the mechanism is poorly understood. This study aimed to investigate the effects of p21 on free fatty acid (FFA)-induced steatosis in L02 cells. We therefore analyzed the L02 cells with MG132 and siRNA treatment for different expression of p21 related to lipid accumulation and lipotoxicity. Cellular total lipid was stained by Oil Red O, while triglyceride content, cytotoxicity assays, lipid peroxidation markers and anti-oxidation levels were measured by enzymatic kits. Treatment with 1 mM FFA for 48 hr induced magnificent intracellular lipid accumulation and increased oxidative stress in p21 overload L02 cells compared to that in p21 knockdown L02 cells. By increasing oxidative stress and peroxidation, p21 accelerates FFA-induced lipotoxic effect in L02 cells and might provide information about potentially new targets for drug development and treatments of NAFLD.

[Clinicopathologic analysis of nodal marginal zone B cell lymphoma].

OBJECTIVE: To investigate the clinicopathologic features of primary nodal marginal zone B-cell lymphoma (NMZL). METHODS: Hematoxylin-Eosin staining and immunohistochemistry were used to evaluate the histological and immunophenotypic characteristics of lymph node (LN) tissue in 22 NMZL cases. Additionally, interphase fluorescence in-situ hybridization (FISH) was carried out to detect the presence of t(11;18) (q21;q21)/API2-MALT1 and/or t(14;18)(q32;q21)/IGH-MALT1 in 9 cases. RESULTS: The median age of the 22 patients was 62 (16 - 77) ys. The male-to-female ratio was 1.2:1. All patients exhibited asymptomatic lymphadenopathy with the cervical region as the most often site to be involved (n = 11), followed by axillary (n = 9), inguinal (n = 7), submandibular (n = 6), mediastinal (n = 4), supraclavicular (n = 2) and retroperitoneal lymph nodes (n = 1). The Ann Arbor stages were I/II in 13 (59%) cases and III/IV in 9 (41%). Immunohistochemical study showed a consistently strong expression of CD20 and an absence in the expression of CD3ε, CD10, CD21, CD23, CyclinD1 and BCL6 by the tumor cells in all the cases. Frequency of expression of CD5 and BCL2 were 39% (7/18) and 30% (3/14) respectively. Among the 9 cases performed with FISH, 2 cases harbored t(14;18)and another 1 case positive for t(11;18) and t(14;18). Complete follow-up data were available for 13 cases. The follow-up time was 6 to 44 months. 3 of them died. 3-year cumulative survival rate was 67%. CONCLUSIONS: NMZL patients are often elderly, which mainly present with multiple lymphadenopathy, rare involvement of extranodal organ and early stage. The diagnosis must be based on a combination of clinicopathologic features, especially those patients detected t(11;18) and/or t(14;18).

Is alcohol consumption associated with gastroesophageal reflux disease?

Gastroesophageal reflux disease (GERD) is one of the most common disorders with an increasing incidence and prevalence. Alcohol consumption may be a risk factor for GERD; however, the relationship remains to be fully elucidated. The results of different studies are diverse and contradictory. Systematic investigations concerning this matter are inappropriate and further well-designed prospective studies are needed to clarify the effect of alcohol on GERD.