Antitumor effects of IL-6 on murine liver tumor cells in vivo

IL-6 is a pleiotropic cytokine that is capable of modulating the diverse functions of hepatocytes such as acute phase responses and inflammation in the liver. To learn its antitumor effects in vivo, the cDNA of IL-6 was transfected into murine liver cells, TIB cells. IL-6-transfected TIB cells (TIB73-IL-6 or TIB75-IL-6) produced much higher levels of IL-6 compared with vector-transfected TIB cells (TIB73-vec or TIB75-vec). To investigate the effects of IL-6 on TIB tumor growth in vivo, IL-6-transfected TIB cells or vector-transfected TIB cells were injected subcutaneously into syngeneic mice. Vector-transfected TIB cells grew rapidly 3 weeks after injection, but IL-6-transfected TIB cells did not grow at all for up to 6 weeks. Pathologically, IL-6-transfected TIB cells demonstrated a severe necrosis and apoptotic pattern. Taken together, these results indicate that IL-6 functions as a growth inhibiting factor in vivo, and another biological role of IL-6 in the liver is suggested.     

Genetic variation in South Indian castes: evidence from Y-chromosome, mitochondrial, and autosomal polymorphisms

Background

Major population movements, social structure, and caste endogamy have influenced the genetic structure of Indian populations. An understanding of these influences is increasingly important as gene mapping and case-control studies are initiated in South Indian populations.

Results

We report new data on 155 individuals from four Tamil caste populations of South India and perform comparative analyses with caste populations from the neighboring state of Andhra Pradesh. Genetic differentiation among Tamil castes is low (R_ST = 0.96% for 45 autosomal short tandem repeat (STR) markers), reflecting a largely common origin. Nonetheless, caste- and continent-specific patterns are evident. For 32 lineage-defining Y-chromosome SNPs, Tamil castes show higher affinity to Europeans than to eastern Asians, and genetic distance estimates to the Europeans are ordered by caste rank. For 32 lineage-defining mitochondrial SNPs and hypervariable sequence (HVS) 1, Tamil castes have higher affinity to eastern Asians than to Europeans. For 45 autosomal STRs, upper and middle rank castes show higher affinity to Europeans than do lower rank castes from either Tamil Nadu or Andhra Pradesh. Local between-caste variation (Tamil Nadu R_ST = 0.96%, Andhra Pradesh R_ST = 0.77%) exceeds the estimate of variation between these geographically separated groups (R_ST = 0.12%). Low, but statistically significant, correlations between caste rank distance and genetic distance are demonstrated for Tamil castes using Y-chromosome, mtDNA, and autosomal data.

Conclusion

Genetic data from Y-chromosome, mtDNA, and autosomal STRs are in accord with historical accounts of northwest to southeast population movements in India. The influence of ancient and historical population movements and caste social structure can be detected and replicated in South Indian caste populations from two different geographic regions.     

Cloning, expression and characterization of xylose isomerase, XylA, from Caldanaerobacter subterraneus subsp. yonseiensis

The xylA gene, coding for xylose isomerase, from the extreme thermophile, Caldanaerobacter subterraneus subsp. yonseiensis was cloned, sequenced, and expressed in Escherichia coli. The nucleotide sequence of the xylA gene encoded a polypeptide of 438 residues with a calculated molecular weight of 50,170 Da. The purified XylA showed high sequence homology (92% identity) with that of Thermoanaerobacter thermohydrosulfuricus. The recombinant enzyme expressed in Escherichia coli was purified by heat treatment and gel chromatography. The purified enzyme was thermostable with optimal activity at 95°C. The enzyme required divalent cations including Zn²⁺ for its maximal activity and thermostability.     

Roles of IFN consensus sequence binding protein and PU.1 in regulating IL-18 gene expression.

IL-18 is expressed from a variety of cell types. Two promoters located upstream of exon 1 (5'-flanking region) and upstream of exon 2 (intron 1) regulate its expression. Both promoter regions were cloned into pCAT-Basic plasmid to yield p1-2686 for the 5'-flanking promoter and p2-2.3 for the intron 1 promoter. Both promoters showed basal constitutive activity and LPS inducibility when transfected into RAW 264.7 macrophages. To learn the regulatory elements of both promoters, 5'-serial deletion and site-directed mutants were prepared. For the activity of the p1-2686 promoter, the IFN consensus sequence binding protein (ICSBP) binding site between -39 and -22 was critical. EMSA using an oligonucleotide probe encompassing the ICSBP binding site showed that LPS treatment increased the formation of DNA binding complex. In addition, when supershift assays were performed, retardation of the protein-DNA complex was seen after the addition of anti-ICSBP Ab. For the activity of the p2-2.3 promoter, the PU.1 binding site between -31 and -13 was important. EMSA using a PU.1-specific oligonucleotide demonstrated that LPS treatment increased PU.1 binding activity. The addition of PU.1-specific Ab to LPS-treated nuclear extracts resulted in the formation of a supershifted complex. Furthermore, cotransfection of ICSBP or PU.1 expression vector increased p1 promoter activity or IL-18 expression, respectively. Taken together, these results indicate that ICSBP and PU.1 are critical elements for IL-18 gene expression.     

ST-segment elevation associated with allergic reaction to echocardiographic contrast agent administration

We report a case of an allergic reaction after the administration of an echocardiographic contrast agent which resulted in ST-segment elevation. Hypersensitivity and allergic reactions are known causes of acute cardiovascular events. However, only limited reports are available which suggest the exact mechanism of the occurrence of angina or myocardial infarction during severe allergic reactions. In our case, through invasive imaging (coronary angiography and IVUS) we have shown for the first time a transient coronary spasm in the absence of intra-coronary thrombus and only minimal neointimal hyperplasia.     

Effect of cell senescence on the impedance measurement of adipose tissue-derived stem cells

Label-free and real-time monitoring of stem cells based on electrical impedance measurement is increasingly utilized for the quality control of the isolated stem cells to be used in stem cell-based tissue therapy or regenerative medicine. In spite of that the proliferative capacity and multipotency of stem cells are dependent on the type and age of the source tissue, however, the effect of the cell senescence on the impedance measurement of stem cells has not yet been studied. We investigated whether the senescence of adipose tissue-derived stem cells (ADSCs) can be detected by electrical impedance spectroscopy. For this, ADSCs at passage 9 and 31 were prepared and those genetic characteristics and growth kinetics were evaluated by quantitative polymerase chain reaction and cell counting. While the identified ADSCs were grown on the indium tin oxide electrodes, the impedance spectra were measured and interpreted by fitting analysis with an equivalent circuit model. ADSCs at passage 9 adhered on the electrode were small and spindle-shaped whereas the cells at passage 31 were flattened and larger than younger cells. At the beginning of culture time when the cell adhesion occurred, the resistance at 4.6 kHz of passage 31 cells was higher than passage 9 due to the larger size of older cells. Afterwards, the value of passage 9 cells increased higher than passage 31, since younger cells proliferated more than old cells. Therefore, the impedance measurement could characterize the proliferative capacity of ADSCs during expanded culture.     

Autodisplay of streptavidin

Streptavidin was expressed on the outer membrane of E. coli as a recombinant fusion protein with an autotransporter domain called AIDA-I (adhesin involved in diffuse adherence) using autodisplay technology. The autodisplay of streptavidin was confirmed by SDS-PAGE of the outer membrane proteins, and the number of autodisplayed streptavidin molecules on a single E. coli cell was evaluated with densitometric analysis. The biotin-binding activity of the autodisplayed streptavidin was estimated after treatment with fluorescently labeled biotin by fluorescence microscopy and flow cytometry. The biotin-binding activity of the E. coli with autodisplayed streptavidin was compared with the activity of streptavidin immobilized on magnetic beads. Finally, the outer membrane presenting autodisplayed streptavidin was isolated and layered on a 96-well microplate for an immunoassay.     

Mutual regulation between DNA-PKcs and snail1 leads to increased genomic instability and aggressive tumor characteristics

Although the roles of DNA-dependent protein kinase catalytic subunits (DNA-PKcs) in the non-homologous end joining (NHEJ) of DNA repair are well-recognized, the biological mechanisms and regulators by DNA-PKcs besides DNA repair, have not been clearly described. Here, we show that active DNA-PKcs caused by ionizing radiation, phosphorylated Snail1 at serine (Ser) 100, led to increased Snail1 stability. Furthermore, phosphorylated Snail1 at Ser100 reciprocally inhibited the kinase activity of DNA-PKcs, resulting in an inhibition of DNA repair activity. Moreover, Snail1 phosphorylation by DNA-PKcs was involved in genomic instability and aggressive tumor characteristics. Our results describe novel cellular mechanisms that affect genomic instability, sensitivity to DNA-damaging agents, and the migration of tumor cells by reciprocal regulation between DNA-PKcs and Snail1.     

Inhalation Toxicity of Humidifier Disinfectants as a Risk Factor of Children’s Interstitial Lung Disease in Korea: A Case-Control Study

Background

The occurrence of numerous cases of interstitial lung disease in children (chILD) every spring in Korea starting in 2006 raised suspicion about a causal relationship with the use of humidifier disinfectants (HDs). The aim of this study was to evaluate the association between HD use and the risk of chILD.

Methods

This retrospective, 1∶3 matched case-control study consisted of 16 cases of chILD that had developed between 2010 and 2011. The three groups of parallel controls (patients with acute lobar pneumonia, asthma, and healthy children) were matched by age, gender, and index date. Indoor/outdoor environmental risk factors, including HD use, were investigated by asking the guardians to complete a questionnaire.

Results

The median age of the affected children (43.8% male) was 26 months (18.25–36.25). The chILD group did not differ significantly from the control groups with respect to socio-demographic and clinical variables. Indoor and outdoor environmental factors were not associated with a risk of chILD. However, the previous use of HDs (OR; 2.73. 95% CI; 1.41–5.90, P = 0.00) were independently associated with an increased risk.

Conclusions

This study showed that HDs, which are widely used in South Korea in the winter season, independently increased the risk of chILD in spring. Therefore, continuous monitoring and, if needed, changes in policy are essential to prevent and control pediatric diseases caused by toxic chemicals.     

The palatability of flavoured novel floating pellets made with brewer's spent grain to captive carp

Abstract

The palatability to common carp, Cyprinus carpio L. of three newly developed differently flavoured floating pellets made from a high proportion (40%) of brewer's spent grain (BSG) was tested using a multiple-offer feeding experiment. The addition of ‘bold’ flavours, such as vanilla or strawberry essence, may help mask the unpleasant taste of some piscicides; however, their inclusion must not compromise uptake by carp. There were no significant differences between the consumption rates of the three varieties, and all flavours were readily consumed. Therefore, it is suggested that highly flavoured pellets made with BSG have a strong potential to mask the flavour of an unpalatable toxin, and further research is now needed to test this hypothesis.