The QuEChERS analytical method combined with low density solvent based dispersive liquid–liquid microextraction for quantitative extraction of multiclass pesticide residues in cereals

In this study, a combination QuEChERS and low density solvent based DLLME was developed for extraction and preconcentration of five multiclass pesticide residues including atrazine, ametryn, terbutryn, carbaryl and chlorothalonil, from selected cereals: Teff, barley and maize samples. Liquid chromatography with variable wavelength detector (VWD) was used for quantitative determination of the pesticides. Various experimental parameters affecting the extraction and the preconcentration efficiencies were optimized. Calibration curves constructed using Teff samples were linear over wide ranges, 7.1-200 μg kg-1 with R2 ≥ 0.990. LODs of the method were ≤ 8.9 μg kg-1, below the MRLs of EU for maize and barley. The RSDs were in the range of 2.3–9.5%. The method has also been applied to different cereal samples and satisfactory average recoveries ranging 69.0–117% were obtained for the spiked cereal samples at two concentration levels. Therefore, the developed method can be successfully utilized as a simple alternative for the analysis of multiclass pesticide residues in cereals and other related samples. KEY WORDS: QuEChERS method, Low density solvent based DLLME, Multiclass pesticide residues, Cereal samples, HPLC-VWD, Quantitative extraction Bull. Chem. Soc. Ethiop. 2017, 31(1), 1-15.DOI: http://dx.doi.org/10.4314/bcse.v31i1.1           

Heavy metal concentrations in fish tissues from Gilgel Gibe (I) Hydroelectric Dam Reservoir, Ethiopia

In this study, the concentrations of selected heavy metals including Cr, Co, Cu, Cd, and Pb were determined in gills, livers, and muscles of two fish species: Orochromis niloticus and Labeoberbus infermedius. The fish samples were collected from Gilgel Gibe I hydroelectric dam reservoir in may 2017. Prior to their quantitative determinations by flame atomic absorption spectroscopy, tissue samples were digested by a microwave digestion. Except, Cr (in gills) and Cd (in muscles), the target metals were detected in the gills, livers and muscles of both fish species and showed varied distributions among the tissues. But, the two species were nearly exhibited similar accumulation orders for the studied heavy metals. The order of concentrations of the metals in gill, liver and muscle of Labeoberbus infermedius were: Cu > Pb > Co > Cd; Cr > Cu > Pb > Co > Cd; and Cr > Pb > Cu > Co, respectively and while, in gill, liver and muscle of Orochromis niloticus were: Cu > Co > Pb > Cd; Cr > Cu > Co > Pb > Cd; and Cr > Pb > Cu > Co, respectively. The highest concentrations of Cr and Co were determined in livers; Cd was detected in the gills of both species; Cu was obtained in the liver of Labeoberbus infermedius and in the gill of Orochromis niloticus. Significant differences were observed among the mean concentrations of the metals in the fish tissues (p < 0.05). The concentrations Cr, Co, and Pb were higher than the maximum permissible limits recommended by FAO/WHO and EU. The concentration of Cu was below the maximum permissible limit of FAO/WHO, but above that of EU.Keywords: Gilgel Gibe I hydroelectric Dam; Orochromis niloticusor; Labeoberbus infermedius; Heavy metal

Visible photoluminescence from planar amorphous silicon nitride microcavities

Fabry-Perot microcavities were used for the enhancement and inhibition of photoluminescence (PL) in a hydrogenated amorphous silicon nitride (a-SiNx:H) microcavity fabricated with and without ammonia. A planar microcavity was realized that included a metallic back mirror and an a-SiNx:H-air or a metallic front mirror. The PL extends from the red part of the spectrum to the near infrared for the samples grown without ammonia. The PL is in the blue-green part of the spectrum for the samples grown with ammonia. The PL amplitude is enhanced and the PL linewidth is reduced with respect to those in bulk a-SiNx:H. The numerically calculated transmittance, reflectance, and absorbance spectra agree well with the experimentally measured spectra. (C) 1998 Optical Society of America [S0740-3224(98)00211-2] OCIS codes: 230.5750, 250.5230, 310.0310

Predicting Chemotherapy Sensitivity Profiles for Breast Cancer Cell Lines with and Without Stem Cell-Like Features

Cataloged from PDF version of article.Our current understanding of cancer-stem cells (CSCs) is that they are slow growing, generally mesenchymallike cells capable of generating tumors. Convincing evidence for the existence of such cells comes from recent lineage tracing experiments. CSCs have been reported as being resistant to conventional drug treatment and have been considered as being responsible for failure of chemotherapy. Recently, several databases aiming the genetic characterization of a large number of cancer cell lines have been made publicly available. In addition to gene expression data, these databases contain cytotoxicity information for all cell lines for a number of drugs as well. It is possible to classify known cell lines derived from a given tumor, based on how similar they are to CSCs, or in other words, to define their stem-ness, using gene-lists that define such cells. Using two such, independently generated, gene lists we found that breast cancer cell lines could be categorized into two distinct groups which we designate CSC-like and non-CSC-like. We then identified drugs to which the two groups were most sensitive to. We also generated sensitivity profiles for all drugs, within one such database, to identify chemotherapeutics with preferential action on breast cancer. We believe this is a straight-forward approach for swiftly identifying drugs that would selectively target a subpopulation of cells for any given tumor type. © 2013 Bentham Science Publishers

Autologous anti-SOX2 antibody responses reflect intensity but not frequency of antigen expression in small cell lung cancer

Cataloged from PDF version of article.Background: Anti-SOX2 antibody responses are observed in about 10 to 20% of small cell lung cancer (SCLC) patients. The aim of this study was to determine whether such responses reflect a particular pattern of SOX2 protein expression in the tumor and whether this pattern associates with clinical outcome. Methods. Paraffin embedded tumor tissues, obtained from SCLC patients who had no evidence of paraneoplastic autoimmune degeneration, were evaluated for SOX2 expression by immunohistochemistry for both intensity and extent of staining. Sera from the same patients were tested for autologous antibodies against recombinant SOX2 by enzyme-linked immunosorbent assay (ELISA). Correlates between overall survival and various clinical parameters including SOX2 staining and serology were determined. Results: SOX2 protein expression was observed in tumor tissue in 89% of patients. Seventeen patients (29%) were seropositive for SOX2 antibodies and, in contrast to SOX2 staining, the presence of antibody correlated with limited disease stage (p = 0.05). SOX2 seropositivity showed a significant association with the intensity of SOX2 staining in the tumor (p = 0.02) but not with the frequency of SOX2 expressing cells. Conclusion: Anti-SOX2 antibodies associate with better prognosis (limited stage disease) while SOX2 protein expression does not; similar to reports from some earlier studies. Our data provides an explanation for this seemingly contrasting data for the first time as SOX2 antibodies can be observed in patients whose tumors contain relatively few but strongly staining cells, thus supporting the possible presence of active immune-surveillance and immune-editing targeting SOX2 protein in this tumor type. © 2014 Atakan et al.; licensee BioMed Central Ltd

Autologous anti-SOX2 antibody responses reflect intensity but not frequency of antigen expression in small cell lung cancer

Background: Anti-SOX2 antibody responses are observed in about 10 to 20% of small cell lung cancer (SCLC) patients. The aim of this study was to determine whether such responses reflect a particular pattern of SOX2 protein expression in the tumor and whether this pattern associates with clinical outcome. Methods. Paraffin embedded tumor tissues, obtained from SCLC patients who had no evidence of paraneoplastic autoimmune degeneration, were evaluated for SOX2 expression by immunohistochemistry for both intensity and extent of staining. Sera from the same patients were tested for autologous antibodies against recombinant SOX2 by enzyme-linked immunosorbent assay (ELISA). Correlates between overall survival and various clinical parameters including SOX2 staining and serology were determined. Results: SOX2 protein expression was observed in tumor tissue in 89% of patients. Seventeen patients (29%) were seropositive for SOX2 antibodies and, in contrast to SOX2 staining, the presence of antibody correlated with limited disease stage (p = 0.05). SOX2 seropositivity showed a significant association with the intensity of SOX2 staining in the tumor (p = 0.02) but not with the frequency of SOX2 expressing cells. Conclusion: Anti-SOX2 antibodies associate with better prognosis (limited stage disease) while SOX2 protein expression does not; similar to reports from some earlier studies. Our data provides an explanation for this seemingly contrasting data for the first time as SOX2 antibodies can be observed in patients whose tumors contain relatively few but strongly staining cells, thus supporting the possible presence of active immune-surveillance and immune-editing targeting SOX2 protein in this tumor type. © 2014 Atakan et al.; licensee BioMed Central Ltd

Assessment of metals in roasted indigenous coffee varieties of Ethiopia

The metals content (Ca, Cd, Cr, Co, Cu, Fe, K, Mg, Mn, Ni, Pb and Zn) of roasted coffee varieties grown in five different regions of Ethiopia was determined by flame atomic absorption spectrometry. Representative samples were collected from Coffee Quality Inspection and Liquoring Center in the capital city, Addis Ababa, Ethiopia and the metals were extracted by wet digestion. The optimal digestion required 4 hours refluxing at 270 oC on Kjeldhal hot plate with a mixture of 5 mL HNO3 (70%) and 1.5 mL HClO4 (70%) to completely digest 0.5 g of roasted coffee samples. Recoveries of metals in the spiked samples varied from 90 to 110%. Analysis of variance revealed significant differences in the concentrations of Ca, Co, Cu, Mn, Cr, Ni and Zn with the variation of coffee beans geographic origin. Pearson correlation coefficients indicated high positive correlation among some metals and high negative correlation among others. The amounts of metals that a person can get from two cups of coffee are well below the daily recommended values and drinking two cups of coffee is safe for an adult person and free from the risks of Cd and Pb toxicity

Colon cancer associated transcript-1 (CCAT1) expression in adenocarcinoma of the stomach

Background: Long non-coding RNAs (lncRNAs) have been shown to have functional roles in cancer biology and are dys-regulated in many tumors. Colon Cancer Associated Transcript -1 (CCAT1) is a lncRNA, previously shown to be significantly up-regulated in colon cancer. The aim of this study is to determine expression levels of CCAT1 in gastric carcinoma (GC). Methods: Tissue samples were obtained from patients undergoing resection for gastric carcinoma (n=19). For each patient, tumor tissue and normal appearing gastric mucosa were taken. Normal gastric tissues obtained from morbidly obese patients, undergoing laparoscopic sleeve gastrectomy served as normal controls (n=19). A human gastric carcinoma cell line (AGS) served as positive control. RNA was extracted from all tissue samples and CCAT1 expression was analyzed using quantitative real time-PCR (qRT-PCR). Results: Low expression of CCAT1 was identified in normal gastric mucosa samples obtained from morbidly obese patients [mean Relative Quantity (RQ) = 1.95±0.4]. AGS human gastric carcinoma cell line showed an elevated level of CCAT1 expression (RQ=8.02). Expression levels of CCAT1 were approximately 10.8 fold higher in GC samples than in samples taken from the negative control group (RQ=21.1±5 vs. RQ=1.95±0.4, respectively, p<0.001). Interestingly, CCAT1 expression was significantly overexpressed in adjacent normal tissues when compared to the negative control group (RQ = 15.25±2 vs. RQ=1.95±0.4, respectively, p<0.001). Tissues obtained from recurrent GC cases showed the highest expression levels (RQ = 88.8±31; p<0.001). Expression levels increased with tumor stage (T4- 36.4±15, T3- 16.1±6, T2- 4.7±1), however this did not reach statistical significance (p=0.2). There was no difference in CCAT1 expression between intestinal and diffuse type GC (RQ=22.4±7 vs. 22.4±16, respectively, p=0.9). Within the normal gastric tissue samples, no significant difference in CCAT1 expression was observed in helicobacter pylori negative and positive patients (RQ= 2.4±0.9 vs. 0.93±0.2, respectively, p=0.13). Conclusion: CCAT1 is up-regulated in gastric cancer, and may serve as a potential bio-marker for early detection and surveillance. © Ivyspring International Publisher

Dominant B-cell epitopes from cancer/stem cell antigen SOC2 recognized by serum samples from cancer patients

Cataloged from PDF version of article.Human sex determining region Y-box 2 (SOX2) is an important transcriptional factor involved in the pluripotency and stemness of human embryonic stem cells. SOX2 plays important roles in maintaining cancer stem cell activities of melanoma and cancers of the brain, prostate, breast, and lung. SOX2 is also a lineage survival oncogene for squamous cell carcinoma of the lung and esophagus. Spontaneous cellular and humoral immune responses against SOX2 present in cancer patients classify it as a tumor-associated antigen (TAA) shared by lung cancer, glioblastoma, and prostate cancer among others. In this study, B-cell epitopes were predicted using computer-assisted algorithms. Synthetic peptides based on the prediction were screened for recognition by serum samples from cancer patients using ELISA. Two dominant B-cell epitopes, SOX2:52-87 and SOX2:98-124 were identified. Prostate cancer, glioblastoma and lung cancer serum samples that recognized the above SOX2 epitopes also recognized the full-length protein based on Western blot. These B-cell epitopes may be used in assessing humoral immune responses against SOX2 in cancer immunotherapy and stem cell-related transplantation

Differential expression of colon cancer associated transcript1 (CCAT1) along the colonic adenoma-carcinoma sequence

Cataloged from PDF version of article.Background: The transition from normal epithelium to adenoma and, to invasive carcinoma in the human colon is associated with acquired molecular events taking 5-10 years for malignant transformation. We discovered CCAT1, a non-coding RNA over-expressed in colon cancer (CC), but not in normal tissues, thereby making it a potential disease-specific biomarker. We aimed to define and validate CCAT1 as a CC-specific biomarker, and to study CCAT1 expression across the adenoma- carcinoma sequence of CC tumorigenesis. Methods: Tissue samples were obtained from patients undergoing resection for colonic adenoma(s) or carcinoma. Normal colonic tissue (n = 10), adenomatous polyps (n = 18), primary tumor tissue (n = 22), normal mucosa adjacent to primary tumor (n = 16), and lymph node(s) (n = 20), liver (n = 8), and peritoneal metastases (n = 19) were studied. RNA was extracted from all tissue samples, and CCAT1 expression was analyzed using quantitative real time-PCR (qRT-PCR) with confirmatory in-situ hybridization (ISH). Results: Borderline expression of CCAT1 was identified in normal tissue obtained from patients with benign conditions [mean Relative Quantity (RQ) = 5.9]. Significant relative CCAT1 up-regulation was observed in adenomatous polyps (RQ = 178.6 +/- 157.0; p = 0.0012); primary tumor tissue (RQ = 64.9 +/- 56.9; p = 0.0048); normal mucosa adjacent to primary tumor (RQ = 17.7 +/- 21.5; p = 0.09); lymph node, liver and peritoneal metastases (RQ = 11,414.5 +/- 12,672.9; 119.2 +/- 138.9; 816.3 +/- 2,736.1; p = 0.0001, respectively). qRT-PCR results were confirmed by ISH, demonstrating significant correlation between CCAT1 up-regulation measured using these two methods. Conclusion: CCAT1 is up-regulated across the colon adenoma-carcinoma sequence. This up-regulation is evident in pre-malignant conditions and through all disease stages, including advanced metastatic disease suggesting a role in both tumorigenesis and the metastatic process