Evaluation of sewage sludge biochar and modified derivatives as novel SPE adsorbents for monitoring of bisphenol A.

Sewage sludge is abundant biomass, the sustainable management of which remains a big issue worldwide. It was demonstrated that pyrolysis of sewage sludge using simple and cost-effective apparatus can produce biochars, suitable for solid-phase extraction applications of hydrophobic analytes. Detailed characterization showed that modification lead to three more hydrophobic and one more hydrophilic sample, compared to the original biochar. All samples were evaluated in the solid-phase extraction of the emerging contaminant Bisphenol A from aqueous solutions. KOH-SSB and KOH/MeOH-SSB exhibited the most promising behavior, with the latter achieving recoveries of 88.1%, at a quantity of 0.1 g at the natural pH of the BPA solution (6.5). The effect of solution pH was insignificant in the range of 4-7, whereas the initial BPA concentration had no effect in the recovery within the range of 1-100 µg L-1. The mechanism of interaction between the optimum sample and BPA was based on hydrogen bonding and π-π interactions, establishing earlier observations that the type (and not concentration) of individual surface groups and the total surface area play a significant role in the process.

R72P polymorphism of TP53 in ulcerative colitis patients is associated with the incidence of colectomy, use of steroids and the presence of a positive family history.

P53 tumor suppressor protein is one of the pivotal regulators for genome integrity, cell cycle and apoptosis. The most commonly and extensively studied single nucleotide polymorphism (SNP) of p53 is Arg>Pro substitution on codon 72 (R72P). Although we know that the SNP has unique functional effects on the protein, its clinical significance is not clearly identified yet. Aim of the study was to access the relationship between R72P genotype distribution and clinical variables in patients with ulcerative colitis (UC) and colorectal cancer (CRC). Genomic DNA samples were extracted from 95 UC, 50 CRC, and 219 healthy controls. R72P genotype analysis was carried out with polymerase chain reaction following by restriction enzyme digestion. We observed that Pro allele carriage is a strong risk factor for CRC (OR = 3.03; 95%CI = 1.91-2.40; p = 0.003), but only modest association with UC (OR = 1.61; 95%CI = 0.98-2.65; p = 0.059) (Pro/Pro and Pro/Arg genotypes vs. Arg/Arg genotype). We did not find any correlation between genotype distribution of the polymorphism and clinical parameters of CRC, but in UC, Pro/Pro genotype was significantly related to an inflammatory bowel disease family history (OR = 8.0; 95%CI = 1.68-38.08, p = 0.015), and Arg/Pro genotype was significantly associated with the history of disease-related colectomy (OR = 17.77; 95%CI = 0.98-323.34, p = 0.012) and steroid use (OR = 10.14; 95%CI = 2.63-39.12, p = 0.0002). Our data suggest that R72P variant seems to be associated with high risk for development of CRC but carries low risk for development of UC. R72P genotypes might be a useful predictive marker for surgical and medical treatment of UC.

Analysis of p53 gene polymorphisms and protein over-expression in patients with breast cancer.

p53 polymorphic variants play an important role in the determination of tumor phenotype and characteristics in breast cancer. In this study, we examined three common polymorphisms in p53 gene and their haplotype combinations to assess their potential association with inherited predisposition to breast cancer development, in relations with the protein over-expression and patients' demographic data. A total of 99 patients with breast cancer and 107 age-matched healthy controls were included in the study. Genotypes were determined using PCR-RFLP and DNA sequencing techniques. Evaluation of p53 protein over-expression was also examined by immunohistochemistry. Among three polymorphisms, increased codon 72 Pro allele frequency (p = 0.0067) and the presence of Pro allele were found to be significantly associated with breast cancer (p = 0.013). A significant risk was also found in subjects with combinations of specific haplotypes and genotypes. Most of breast cancer women especially younger than 50 years carry at least one p53 polymorphism (p = 0.001). There was no any association between these three p53 polymorphisms and the protein over-expression, separately or in interaction, with breast cancer. In conclusion, presence of proline allele at codon 72 alone, and its special combinations with other two polymorphisms appear to be a significant risk factor for breast cancer. Determination of well-known p53 polymorphisms might be a good predictor for breast cancer development especially in women younger than 50 years.

Relationship between overexpression of ras p21 oncoprotein and K-ras codon 12 and 13 mutations in Turkish colorectal cancer patients.

BACKGROUND/AIMS: The activation of ras family genes plays an important role in colorectal tumorigenesis. We investigated the clinicopathological characteristics and point mutations of K-ras oncogene codons 12/13 and ras p21 expression using paraffinembedded materials from cancerous and the surrounding normal tissues of 53 colorectal cancer cases. METHODS: K-ras codons 12 and 13 point mutations were analyzed by PCR-Single- Strand Conformational Polymorphism (SSCP) and followed by DNA sequencing, while ras p21 expression was evaluated using immunohistochemistry. RESULTS: Mutations of K-ras and overexpression of the ras p21 were detected in 11% and 76% of the tumors, respectively. Ras protein level in tumor was increased an average of 4.6-fold over that of normal mucosa. Ras p21 overexpression did not correlate with any of the clinicopathological parameters examined. K-ras gene mutations were found mostly in the presence of a mucinous component within the tumor (p=0.06). Follow-up data were available for 43 patients. There was no statistically significant correlation between these alterations and patient outcomes. CONCLUSIONS: Our data suggest that, apart from K-ras codons 12/13 point mutations, overexpression of the ras family genes is important in the development of the disease but it appears not to be predictive of survival. Furthermore, mucinous secretion in the colorectum may represent a distinct genetic pattern.

Comparing the effect of sub-critical water extraction with conventional extraction methods on the chemical composition of Lavandula stoechas.

The volatile extract composition of Lavandula stoechas flowers obtained by hydrodistillation (HD), subcrtical water extraction (SbCWE) and organic solvent extraction under ultrasonic irradiation (USE) were estimated by gas chromatography-mass spectrometry (GC-MS). One hundred and twenty four components were detected in SbCWE extracts while 94 and 65 signals were gained from HD and USE extracts, respectively. Most of the constituents were identified. The major compounds in all three extracts were fenchon, camphor, myrtenyl acetate, myrtenol and 1,8-cineol, but they differ in quantitatively. The total monoterpene hydrocarbons are higher in HD and USE extracts than those of SbCWE extract. However, SbCWE extract had higher concentration of light oxygenated compounds which contributes to the fragrance of the oil in a major extension. Heavy-oxygenated compounds was also in higher abundance in SbCWE extract (9.90%) than those of HD and USE extracts (3.19 and 4.78%, respectively). Effect of temperature on the extraction yield of SbCWE was investigated and while oil yield was increasing with an increase in temperature, a decrease in the extraction ability of sub-critical water toward the more polar compounds such as, 1,8-cineol, camphor and fenchon, was observed. Kinetic studies shown that SbCWE is clearly quicker than conventional alternatives. Most of components of volatile compounds were extracted at 15min.

Clinical significance of p53, K-ras and DCC gene alterations in the stage I-II colorectal cancers.

BACKGROUND AND AIMS: Genetic alterations of p53, K-ras and DCC genes have a pivotal role in the colorectal cancer progression. The aim of this study was to clarify the association between K-ras mutations, p53 aberrations and DCC loss of heterozygosity (LOH), with the patient outcome and tumor characteristics in 43 stage I-II colorectal cancer patients. METHODS: Mutations in exons 5-8 of the p53 gene and codon 12 and/or 13 of the K-ras gene were assayed by PCR-SSCP and then confirmed by DNA sequencing. DCC LOH was studied by PCR-RFLP, while p53 immunohistochemistry was also made. RESULTS: Mutations of the p53 gene were found in 14 (32.5%) tumors. Five (12%) cases showed mutation of the K-ras gene. Nuclear staining of p53 was found in 22 (51 %) cases. DCC LOH was found in 5 (12%) cases. Cases with guanine to thymine substitution that occurred in K-ras codon 12 and DCC LOH were found to be more aggressive than other cases with codon 12 mutations or DCC wild-type phenotype. Many tumors with p53 over-expression were localized on the left side of the colon (p=0.005). The stage of the tumor was higher in patients who died during the follow-up period, when compared to the ones who have survived. CONCLUSIONS: Although none of these genetic alterations showed a significant prognostic value, specific mutation of K-ras gene and DCC LOH phenotype might have a predictive prognostic implication in colorectal cancer. Furthermore, different etiopathogenetic mechanisms might be involved in the tumorigenesis of the left and right colon.

A novel approach for rapid screening of mitochondrial D310 polymorphism.

BACKGROUND: Mutations in the mitochondrial DNA (mtDNA) have been reported in a wide variety of human neoplasms. A polynucleotide tract extending from 303 to 315 nucleotide positions (D310) within the non-coding region of mtDNA has been identified as a mutational hotspot of primary tumors. This region consists of two polycytosine stretches interrupted by a thymidine nucleotide. The number of cytosines at the first and second stretches are 7 and 5 respectively, according to the GeneBank sequence. The first stretch exhibits a polymorphic length variation (6-C to 9-C) among individuals and has been investigated in many cancer types. Large-scale studies are needed to clarify the relationship between cytosine number and cancer development/progression. However, time and money consuming methods such as radioactivity-based gel electrophoresis and sequencing, are not appropriate for the determination of this polymorphism for large case-control studies. In this study, we conducted a rapid RFLP analysis using a restriction enzyme, BsaXI, for the single step simple determination of 7-C carriers at the first stretch in D310 region. METHODS: 25 colorectal cancer patients, 25 breast cancer patients and 41 healthy individuals were enrolled into the study. PCR amplification followed by restriction enzyme digestion of D310 region was performed for RFLP analysis. Digestion products were analysed by agarose gel electrophoresis. Sequencing was also applied to samples in order to confirm the RFLP data. RESULTS: Samples containing 7-C at first stretch of D310 region were successfully determined by the BsaXI RFLP method. Heteroplasmy and homoplasmy for 7-C content was also determined as evidenced by direct sequencing. Forty-one percent of the studied samples were found to be BsaXI positive. Furthermore, BsaXI status of colorectal cancer samples were significantly different from that of healthy individuals. CONCLUSION: In conclusion, BsaXI RFLP analysis is a simple and rapid approach for the single step determination of D310 polymorphism of mitochondrial DNA. This method allows the evaluation of a significant proportion of samples without the need for sequencing- and/or radioactivity-based techniques.