| 1. |
- Bekiroglu, Somer, et al.
(författare)
-
Validation of a quantitative NMR method for suspected counterfeit products exemplified on determination of benzethonium chloride in grapefruit seed extracts
- 2008
-
Ingår i: Journal of Pharmaceutical and Biomedical Analysis. - : Elsevier BV. - 0731-7085 .- 1873-264X. ; 47:4-5, s. 958-961
-
Tidskriftsartikel (refereegranskat)abstract
- A H-1-nuclear magnetic resonance (NMR) spectroscopy method for quantitative determination of benzethonium chloride (BTC) as a constituent of grapefruit seed extract was developed. The method was validated, assessing its specificity, linearity, range, and precision, as well as accuracy, limit of quantification and robustness. The method includes quantification using an internal reference standard, 1,3,5-trimethoxybenzene, and regarded as simple, rapid, and easy to implement. A commercial grapefruit seed extract was studied and the experiments were performed on spectrometers operating at two different fields, 300 and 600 MHz for proton frequencies, the former with a broad band (BB) probe and the latter equipped with both a BB probe and a CryoProbe (TM). The concentration average for the product sample was 78.0, 77.8 and 78.4 mg/ml using the 300 BB probe, the 600 MHz BB probe and CryoProbe (TM), respectively. The standard deviation and relative standard deviation (R.S.D., in parenthesis) for the average concentrations was 0.2 (0.3%), 0.3 (0.4%) and 0.3 mg/ml (0.4%), respectively.
|
|
| 2. |
- Hubatsch, Ina, et al.
(författare)
-
Beta- and gamma-di- and tripeptides as potential substrates for the oligopeptide transporter hPepT1
- 2007
-
Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 50:21, s. 5238-5242
-
Tidskriftsartikel (refereegranskat)abstract
- The hPepT1-mediated transport properties of a series of 11 synthesized beta- and gamma-peptides have been studied in Caco-2 cells. The results show that several of the compounds interact with the peptide transporter, but only two beta-dipeptides act as substrates and are transported across the cell monolayers. These two are less-efficient substrates than alfa-peptides. Larger derivatives than beta-dipeptides do not act as hPepT1 substrates, but instead, they appear to be substrates for P-glycoprotein efflux.
|
|
| 3. |
- Lönnroth, Christina, 1946, et al.
(författare)
-
Preoperative treatment with a non-steroidal anti-inflammatory drug (NSAID) increases tumor tissue infiltration of seemingly activated immune cells in colorectal cancer.
- 2008
-
Ingår i: Cancer immunity : a journal of the Academy of Cancer Immunology. - 1424-9634. ; 8
-
Tidskriftsartikel (refereegranskat)abstract
- This study evaluates HLA gene expression and tumor infiltration by B-cells, macrophages, dendritic cells, T-helper and cytotoxic T-lymphocytes in response to short-term preoperative treatment with cyclooxygenase inhibitors. Patients with colorectal carcinoma were randomized to receive oral NSAID (indomethacin or celebrex) for three days preoperatively; controls received esomeprazol. Peroperative tumor biopsies and normal colon tissue were analyzed by microarray, quantitative PCR and immunohistochemistry. Efficacy of short-term systemic NSAID treatment was confirmed by measurement of PGE2 production in blood monocytes from healthy volunteers. NSAID treatment upregulated genes at the MHC locus on chromosome 6p21 in tumor tissue, but not in normal colon tissue, from the same patient. 23 of the 100 most upregulated genes belonged to MHC class II. HLA-DM, -DO (peptide loading), HLA-DP, -DQ, -DR (antigen presentation), granzyme B, H, perforin and FCGR3A (CD16) (cytotoxicity) displayed increased expression, as did CD8, a marker of cytotoxic T-lymphocytes, while HLA-A and -C expression were not increased by NSAID treatment. MHC II protein (HLA-DP, -DQ, -DR) levels and infiltration by CD4+ T-helper cells of tumor stroma increased upon NSAID treatment, while CD8+ cytotoxic T-lymphocytes increased in both tumor stroma and epithelium. Molecules associated with immunosuppressive T regulatory cells (FOXP3, IL-10) were significantly decreased in indomethacin-exposed tumors. Standard oral administration of NSAID three days preoperatively was enough to increase tumor infiltration by seemingly activated immune cells. These findings agree with previous information that high prostanoid activities in colorectal cancer increase the risk for reduced disease-specific survival following tumor resection.
|
|
