ß-Catenin accumulation and S33F mutation of CTNNB1 gene in colorectal cancer in Saudi Arabia.

Several risk factors associated with colorectal cancer (CRC) have been identified including ß-catenin/CTNNB1 hotspot mutations. The levels of ß-catenin within a cell are regulated via phosphorylation of the N terminus of ß-catenin by GSK-3ß. Thus far three serines (S33, 37, 45) and one threonine (T41) are considered to be the substrates for GSK-3ß phosphorylation. In the present investigation an attempt was made to study the role of ß-catenin mutations in exon-3 in 60 colorectal cancer patients from Kingdom of Saudi Arabia (KSA). The hot spot mutation region of ß-catenin exon 3 was evaluated in matched tumor and normal tissues using PCR and direct sequencing. Sequencing of exon 3 of the CTNNB1 gene revealed an activating mutation (S33F) in one of the tumor samples as compared to the normal tissue from the same patient where there was no such mutation found. Immunohistochemical staining showed the accumulation of ß-catenin protein both in cytoplasm and in the nuclei of cancer cells as compared to normal tissue.

bak deletion stimulates gastric epithelial proliferation and enhances Helicobacter felis-induced gastric atrophy and dysplasia in mice.

Helicobacter infection causes a chronic superficial gastritis that in some cases progresses via atrophic gastritis to adenocarcinoma. Proapoptotic bak has been shown to regulate radiation-induced apoptosis in the stomach and colon and also susceptibility to colorectal carcinogenesis in vivo. Therefore we investigated the gastric mucosal pathology following H. felis infection in bak-null mice at 6 or 48 wk postinfection. Primary gastric gland culture from bak-null mice was also used to assess the effects of bak deletion on IFN-γ-, TNF-α-, or IL-1ß-induced apoptosis. bak-null gastric corpus glands were longer, had increased epithelial Ki-67 expression, and contained fewer parietal and enteroendocrine cells compared with the wild type (wt). In wt mice, bak was expressed at the luminal surface of gastric corpus glands, and this increased 2 wk post-H. felis infection. Apoptotic cell numbers were decreased in bak-null corpus 6 and 48 wk following infection and in primary gland cultures following cytokine administration. Increased gastric epithelial Ki-67 labeling index was observed in C57BL/6 mice after H. felis infection, whereas no such increase was detected in bak-null mice. More severe gastric atrophy was observed in bak-null compared with C57BL/6 mice 6 and 48 wk postinfection, and 76% of bak-null compared with 25% of C57BL/6 mice showed evidence of gastric dysplasia following long-term infection. Collectively, bak therefore regulates gastric epithelial cell apoptosis, proliferation, differentiation, mucosal thickness, and susceptibility to gastric atrophy and dysplasia following H. felis infection.

Evaluation of patient effective doses in CT urography, intravenous urography and renal scintigraphy.

Imaging of the renal system is performed with different techniques depending mainly on clinical symptoms and signs. This study intended to evaluate patient effective doses undergoing renal scintigraphy (technetium-99m-diethylene-triamine-pentaacetic acid), computed tomography urography (CTU) and intravenous urography (IVU). A total of 60 patients were evaluated using Orbiter 37 Gamma camera single head, dual-slice CT scanner and conventional X-ray machine with computed radiography (CR) processing unit. Patients effective dose were estimated using the administered activity, DosCal software and dose length product value for renal scan, IVU and CTU procedures, respectively. Patients' effective doses during renal scan, CTU and IVU procedures were 0.78 ± 0.18, 2.53 ± 0.94 and 1.81 ± 0.20 mSv, in that order. Patients were exposed to a higher effective dose during CTU compared with other two procedures. Patient doses depend on the size of patient, the type of scanner and the imaging protocol used. Effective doses considered low compared with previous studies.

Measurement of patient radiation doses in certain urography procedures.

Patients are exposed to significant radiation doses during diagnostic and interventional urologic procedures. This study aimed to measure patient entrance surface air kerma (ESAK) and to estimate the effective dose during intravenous urography (IVU), extracorporeal shock-wave lithotripsy (ESWL), and ascending urethogram (ASU) procedures. ESAK was measured in patients using calibrated thermo luminance dosimeters, GR200A). Effective doses (E) were calculated using the National Radiological Protection Board (NRPB) software. A total of 179 procedures were investigated. 27.9 % of the patients underwent IVU procedures, 27.9 % underwent ESWL procedures and 44.2 % underwent ASU procedures. The mean ESAK was 2.1, 4.18 and 4.9 mGy for IVU, ESWL, and ASU procedures, respectively. Differences in patient ESAK for the same procedure were observed. The mean ESAK values were comparable with those in previous studies.

Radiation doses in chest, abdomen and pelvis CT procedures.

Computed tomography (CT) scanning is recognised as a high-radiation dose modality and estimated to be 17 % of the radiological procedure and responsible for 70 % of medical radiation exposure. Although diagnostic X rays provide great benefits, their use involves some risk for developing cancer. The objectives of this study are to estimate radiation doses during chest, abdomen and pelvis CT. A total of 51 patients were examined for the evaluation of metastasis of a diagnosed primary tumour during 4 months. A calibrated CT machine from Siemens 64 slice was used. The mean age was 48.0 ± 18.6 y. The mean patient weight was 73.8 ± 16.1 kg. The mean dose-length product was 1493.8 ± 392.1 mGy cm, Volume CT dose index (CTDI vol) was 22.94 ± 5.64 mGy and the mean effective dose was 22.4 ± 5.9 mSv per procedure. The radiation dose per procedure was higher as compared with previous studies. Therefore, the optimisation of patient's radiation doses is required in order to reduce the radiation risk.