Determining potential probiotic properties of human originated Lactobacillus plantarum strains

In this study, twenty Lactobacillus plantarum strains which were isolated from the fecal samples of humans were investigated in vitro for their characteristics as potential new probiotic strains. The L. plantarum strains were examined for resistance to gastric acidity in simulated gastric juice at pH 2.0, 2.5, 3.0, and 3.5. The growth of test cultures with different pH was monitored after 0, 10, 30, 60, 90, and 120 min of incubation using a spectrophotometer at 550 nm. At the same time, samples were serially diluted in sterile PBS, and counts of viable bacteria were determined by plate counts using MRS agar for each pH and time parameter. The strains were also examined for resistance to 0.4% phenol, production of H₂O₂, adhesion to Caco-2 cell line and antimicrobial activity. It was determined that the artificial gastric juice, even at pH 2.0, did not significantly change the viability of the cultures. Except L. plantarum AA1-2, all strains were detected at 8 ～ 9 log₁₀ CFU/g. It was found that all L. plantarum strains showed good resistance to 0.4% phenol, and only one strain (AC18-82) produced H₂O₂. Good adhesion of L. plantarum strains to Caco-2 cells was observed in this experiment. These selected strains also showed antimicrobial activity.     

Crosslinked aggregates of Rhizopus oryzae lipase as industrial biocatalysts: Preparation, optimization, characterization, and application for enantioselective resolution reactions

Lipase from Rhizopus oryzae (ROL) was immobilized as crosslinked enzyme aggregate (CLEA) via precipitation with ammonium sulfate and simultaneous crosslinking with glutaraldehyde. The optimum conditions of the immobilization process were determined. Lipase CLEAs showed a twofold increase in activity when Tween 80‐pretreated lipase was used for CLEA preparation. CLEAs were shown to have several advantages compared to free lipase. CLEAs were more stable at 50°C and 60°C as well as for a wide range of pH. After incubation at 50°C, CLEA showed 74% of initial activity whereas free enzyme was totally inactivated. Reduction of Schiff bases has been performed for the first time in the CLEA preparation process significantly improving the chemically modified CLEAs' reusability, thus providing an enzyme with high potential for recycling even under aqueous reaction conditions where enzyme leakage is, in general, one of the major problems. The CLEA retained 91% activity after 10 cycles in aqueous medium. The immobilized enzyme was used for kinetic resolution reactions. Results showed that immobilization had an enhancing effect on the conversion (c) as well as on the enantiomeric ratio (E). ROL CLEA displayed five times higher enantioselectivity for the hydrolysis of (R,S)‐1‐phenylethyl acetate and likewise 1.5 times higher enantioselectivity for the transesterification of racemic (R–S)‐1‐phenylethanol with vinylacetate. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 28: 937–945, 2012 This article was published online on June 26, 2012. An edit was subsequently requested. This notice is included in the online and print versions to indicate that both have been corrected [27 June 2012].     

The mutagenic and antimutagenic effects of Ecballium elaterium fruit juice in human peripheral lymphocytes

The aim of this study was to investigate the mutagenic and antimutagenic effects of Ecballium elaterium (EE) fruit juice, which has an anti-inflammatory effect, using in vitro human peripheral lymphocytes. To investigate the mutagenic effects of the EE fruit juice, human peripheral lymphocytes were treated with three doses (18, 36, and 72 μl/l) of fruit juice alone for 24 and 48 h. For investigating the antimutagenic effects of the EE fruit juice, the human lymphocytes were also treated with the mixture of the fruit juice and 0.25 μg/ml MMC. The EE fruit juice induced the percentage of total CA when used alone (especially the percentage of structural CA than the percentage of the numerical CA) and synergically induced the percentage of total CA when used as a mixture with MMC. The EE fruit juice did not affect the SCE frequency for 24 and 48 h treatment time. In contrast, EE and MMC as a mixture sinergically induced the SCE frequency at the highest concentration for 48 h treatment time only. EE alone did not decrease the RI while it decreased the MI in a dose-dependent manner. EE and MMC as a mixture have a higher cytotoxic effect than the cytotoxic effects of EE alone. As a result, it can be concluded that EE had no antimutagenic effect while EE had a mutagenic and a cytotoxic effect in human peripheral lymphocytes. This article was submitted by the authors in English.     

Characterization of humic materials extracted from hazelnut husk and hazelnut husk amended soils

This study was carried out to determine effects of composted hazelnut husk (CHH) on some chemical properties of soil and soil humic acid (HA). Compost application increases organic matter (OM) content of the soil considerably, OM value of 3.18% became 3.89% in 3 years time interval. Before application of compost, the soil pH was found to be 5.37, while after compost application it became 5.61. FTIR characteristics of humic acid/humic acid-like materials extracted from the original hazelnut husk, composted hazelnut husk and composted hazelnut husk amended soil have been investigated. C and O content of humic acid-like/humic acid materials were in the range of 41.4–50.8% and 37.8–50.5%, respectively. The N content of the humic acid/humic acid-like materials are in the expected range for humic materials which is 2–6%. Comparison of FTIR spectra of hazelnut husk and composted hazelnut husk humic acid-like fractions shows that both exhibit similar but not identical series of IR bands indicating the presence of the same functional groups in both samples. The only difference in the spectra seemed to be a decrement in the peak intensities of composted sample compared to uncomposted one. The similar differentiation of the intensities of IR bands of compost applied soil sample has also been observed. The FTIR spectral results show that the characteristics of composted material tend to become similar to that of soil humic acids characteristics in time.     

Antituberculosis drug resistance patterns in two regions of Turkey: a retrospective analysis

Backround  

The emergence of Mycobacterium tuberculosis strains resistant to antituberculosis agents has recently received increased attention owing largely to the dramatic outbreaks of multi drug resistance tuberculosis (MDR-TB).     

Mutation Profiling in Cholangiocarcinoma: Prognostic and Therapeutic Implications

Background

Cholangiocarcinoma (CCA) is clinically heterogeneous; intra and extrahepatic CCA have diverse clinical presentations. Next generation sequencing (NGS) technology may identify the genetic differences between these entities and identify molecular subgroups for targeted therapeutics.

Methods

We describe successful NGS-based testing of 75 CCA patients along with the prognostic and therapeutic implications of findings. Mutation profiling was performed using either a) NGS panel of hotspot regions in 46 cancer-related genes using a 318-chip on Ion PGM Sequencer or b) Illumina HiSeq 2000 sequencing platform for 3,769 exons of 236 cancer-related genes plus 47 introns from 19 genes to an average depth of 1000X. Clinical data was abstracted and correlated with clinical outcome. Patients with targetable mutations were referred to appropriate clinical trials.

Results

There were significant differences between intrahepatic (n = 55) and extrahepatic CCA (n = 20) in regard to the nature and frequency of the genetic aberrations (GAs). IDH1 and DNA repair gene alterations occurred more frequently in intrahepatic CCA, while ERBB2 GAs occurred in the extrahepatic group. Commonly occurring GAs in intrahepatic CCA were TP53 (35%), KRAS (24%), ARID1A (20%), IDH1 (18%), MCL1 (16%) and PBRM1 (11%). Most frequent GAs in extrahepatic CCA (n = 20) were TP53 (45%), KRAS (40%), ERBB2 (25%), SMAD4 (25%), FBXW7 (15%) and CDKN2A (15%). In intrahepatic CCA, KRAS, TP53 or MAPK/mTOR GAs were significantly associated with a worse prognosis while FGFR GAs correlated with a relatively indolent disease course. IDH1 GAs did not have any prognostic significance. GAs in the chromatin modulating genes, BAP1 and PBRM1 were associated with bone metastases and worse survival in extrahepatic CCA. Radiologic responses and clinical benefit was noted with EGFR, FGFR, C-met, B-RAF and MEK inhibitors.

Conclusion

There are significant genetic differences between intra and extrahepatic CCA. NGS can potentially identify disease subsets with distinct prognostic and therapeutic implications.     

Levels of paraoxonase and arylesterase activities and malondialdehyde in workers exposed to ionizing radiation

We examined levels of malondialdehyde (MDA) (an end-product of lipid peroxidation) and paraoxonase (PON1) (an antioxidant enzyme) activity and PON1 phenotypes in people who were exposed to ionizing radiation for different time periods and doses. A total of 78 individuals (mean age 34 +/- 7 years) were included in the study. Fifty-one of them were radiology workers whereas the control group was composed of 27 healthy volunteers who had never worked in a radiology-related job. Paraoxon was used as substrate for measurement of PON1 activity levels (basal and NaCl-stimulated). Phenylacetate was used as substrate for measurement of arylesterase activity levels. Cumulative levels of serum NaCl-stimulated PON1/arylesterase activities were utilized for phenotypic differentiation. In radiology workers, three different phenotypes were determined based on paraoxonase/arylesterase ratio. The ratios were 1.09 +/- 0.30 for AA (homozygote low activity); 2.91 +/- 1.07 for AB (heterozygote activity) and 4.97 +/- 1.21 for BB (homozygote high activity). There was a statistically meaningful negative correlation between serum MDA levels and PON1 activity levels in all phenotypes (p < 0.05). PON1 activity levels were found to be 25-35% lower in people who were exposed to long-term ( > 5 years) radiation compared to controls. There was no statistically significant correlation between serum arylesterase activity and MDA levels in these subjects (r = -0.185, p > 0.05). PON1 activity levels were decreased whereas serum MDA levels were increased in individuals exposed to radiation for a long period. PON phenotypes of people employed in jobs which expose them to radiation should be determined and based on these findings they should be advised to avoid risk factors inducing oxidative stress, such as smoking, and to consume foods rich in vitamins and trace elements to increase their antioxidant capacity.