EVALUATION OF THE OBSERVANCE OF RADIATION PROTECTION PRINCIPLES IN KERMANSHAH PROVINCE (WEST OF IRAN) 2020: CROSS-SECTIONAL STUDY.

In this descriptive cross-sectional study by census method, the performance of 116 radiographers in the target centers was evaluated in relation to the observance of radiation protection principles with respect to patients, patient companion and radiographers. The data collection tool was a checklist containing 34 principles of radiation protection that were used after confirmation of its continuity and justifiability. The results showed that only in (39.2%) 45 radiographers the observance rate of the principles of radiation protection was acceptable. The highest and lowest levels in which radiographers observed protective principles were observance of protective principles with respect to themselves (60.8%) and protective principles respect of the patient companion (6.3%), respectively. According to the findings, radiation protection principles are not systematically designed, implemented, controlled and monitored by radiographers, and less than half of the radiographers observe the protection principles at the optimal level.

Quantification accuracy for dynamic contrast enhanced (DCE) CT imaging: phantom and quality assurance framework.

PURPOSE: Standardization and protocol optimization is essential for quantification of Dynamic Contrast Enhanced CT as an imaging biomarker. Currently, no commercially available quality assurance (QA) phantoms can provide for testing a complete set of imaging parameters pertaining to routine quality control for contrast-enhanced (CE) CT, as well as spatiotemporal accuracy. The purpose of this work was, therefore: (a) developing a solid calibration phantom for routine CE CT quality assurance; (b) investigating the sensitivity of CECT to organ motion, and (c) characterizing a volumetric CT scanner for CECT. METHODS: CECT calibration phantom consisting of an acrylic uniform cylinder containing multiple capsules of varying diameters and orientations was designed and built. The capsules contain different solid density materials mimicking iodine contrast enhancement. Sensitivity and accuracy of CECT measurements on all capsules was performed using a 320-slice CT scanner for a range of scan parameters both with and without phantom motion along the transaxial axis of the scanner. RESULTS: Routine commissioning tests such as uniformity, spatial resolution and image noise were successfully determined using the CECT phantom. Partial volume effect and motion blurring both contribute to a general decrease in contrast enhancement and this was further dependent on capsule orientation (least pronounced for the transaxial orientation). Scanning with a rotation time of less than 0.5 s, the effect of blurring is less than 3% for all orientations and phantom speeds. CONCLUSION: A new robust contrast calibration phantom was developed and used to evaluate the performance of a 320-slice volumetric CT scanner for DCE-CT.

In vivo neutron activation study of the short-term kinetic behaviour of sodium and chlorine in the human hand.

The time-dependent behaviour of sodium and chlorine was studied as a spinoff from a study of aluminum in the hand of subjects suffering from Alzheimer's disease and a control group, involving 15 Alzheimer's and 16 control subjects with an age range of 63-89 years. This was achieved using the in vivo neutron activation analysis system developed at McMaster University for the non-invasive measurement of aluminum, where a subject's hand is placed in a beam of accelerator-based thermalized neutrons, which activates elements by neutron capture. Following irradiation, the subject's hand is placed in a detection system comprising 9 NaI(Tl) detectors arranged in a 4π geometry to measure activated elements. The redistribution half-lives of the activation products 24Na and 38Cl from the hand were determined after correction for the physical half-life, by means of sequential analysis of the residual activity in the hand. The kinetic behaviours of sodium and chlorine were best characterized by an exponential function corresponding to the rapidly exchangeable pool. The mean redistribution half-lives from the hand for sodium and chlorine in the control subjects were 40.5 ± 17.4 min and 24.2 ± 8.5 min, respectively. For Alzheimer's disease subjects the mean redistribution half-lives were 58.2 ± 36.1 min for sodium and 33.6 ± 16.7 min for chlorine. There was no significant difference in chlorine and sodium redistribution half-lives between the Alzheimer's disease and control group subjects. These results are promising, given that the irradiation and counting protocol were optimized for the aluminum study, rendering them suboptimal for analyzing other elements and their rate of change with time. Further improvements include optimizing the irradiation protocol, longer counting times, and measuring the activity in the un-irradiated hand in various time intervals following irradiation.

Optimization of data analysis for the in vivo neutron activation analysis of aluminum in bone.

An existing system at McMaster University has been used for the in vivo measurement of aluminum in human bone. Precise and detailed analysis approaches are necessary to determine the aluminum concentration because of the low levels of aluminum found in the bone and the challenges associated with its detection. Phantoms resembling the composition of the human hand with varying concentrations of aluminum were made for testing the system prior to the application to human studies. A spectral decomposition model and a photopeak fitting model involving the inverse-variance weighted mean and a time-dependent analysis were explored to analyze the results and determine the model with the best performance and lowest minimum detection limit. The results showed that the spectral decomposition and the photopeak fitting model with the inverse-variance weighted mean both provided better results compared to the other methods tested. The spectral decomposition method resulted in a marginally lower detection limit (5µg Al/g Ca) compared to the inverse-variance weighted mean (5.2µg Al/g Ca), rendering both equally applicable to human measurements.

Role of white-matter pathways in coordinating alpha oscillations in resting visual cortex.

In the absence of cognitive tasks and external stimuli, strong rhythmic fluctuations with a frequency ≈ 10 Hz emerge from posterior regions of human neocortex. These posterior α-oscillations can be recorded throughout the visual cortex and are particularly strong in the calcarine sulcus, where the primary visual cortex is located. The mechanisms and anatomical pathways through which local \alpha-oscillations are coordinated however, are not fully understood. In this study, we used a combination of magnetoencephalography (MEG), diffusion tensor imaging (DTI), and biophysical modeling to assess the role of white-matter pathways in coordinating cortical α-oscillations. Our findings suggest that primary visual cortex plays a special role in coordinating α-oscillations in higher-order visual regions. Specifically, the amplitudes of α-sources throughout visual cortex could be explained by propagation of α-oscillations from primary visual cortex through white-matter pathways. In particular, α-amplitudes within visual cortex correlated with both the anatomical and functional connection strengths to primary visual cortex. These findings reinforce the notion of posterior α-oscillations as intrinsic oscillations of the visual system. We speculate that they might reflect a default-mode of the visual system during which higher-order visual regions are rhythmically primed for expected visual stimuli by α-oscillations in primary visual cortex.

Temporary eyelash loss following dental treatment.

The isolated absence or loss of eyelashes (madarosis) is associated with many processes including systemic and local diseases. Madarosis of dental origin has not been reported. This paper is a report of the successful treatment of unilateral eyelash loss following root canal therapy of an upper posterior tooth.

Occupational stress and work-related unintentional injuries among Iranian car manufacturing workers.

This study in 2004 and 2005 aimed to present the pattern of job stress among car manufacturing workers in one factory in the Islamic Republic of Iran, and to assess its relationship with occupational injuries. Data were collected from 608 male workers (508 at-risk general workers and 100 with injuries in the last year). Job stress was assessed by the Belkic occupational stress index. The prevalence of job stress was 21.3%. The main occupational stressors were time pressure (78.5%), mode of payment and evaluation (56.4%), and interaction with people and machines (41.3%). The risk of injury among those with job stress was significantly higher than those without job stress (OR = 2.0; 95% CI: 1.20-3.30). Job stress was responsible for 11.9% of all occupational injuries in this group.

COX-2 inhibition demonstrates potent anti-proliferative effects on bladder cancer in vitro.

PURPOSE: The purpose of this work was to determine the in vitro effect of Rofecoxib and specific COX 1 and COX 2 inhibitors in regards to cell growth and apoptotic and necrotic activity. INTRODUCTION AND OBJECTIVE: Rofecoxib (Vioxx) is a nonsteroidal anti-inflammatory agent (NSAID) that selectively inhibits cyclooxygenase-2 (COX-2). The inducible isoform of COX-2 is overexpressed in many gastrointestinal and genitourinary tract tumors. We hypothesized that in vitro treatment with both COX-1 and COX-2 inhibitors would significantly reduce cellular proliferation of bladder cancer cells by apoptotic pathways. MATERIALS AND METHODS: Two human bladder cancer cell lines were grown in culture using standard techniques and treated with Rofecoxib at doses ranging from 125 microg/well serially diluted down to 8.0 microg/well. Catechin (COX 1 inhibitor) and NS398 (COX 2 inhibitor) were used at doses of 50 and 100 microM. Cell viability was measured by MTT at 24 and 72 h. Apoptosis was evaluated by the Annexin V FITC Assay. Statistical analysis was performed by ANOVA. RESULTS: Rofecoxib, Catechin, and NS398 all exhibited significant inhibition of cell growth when compared to the nontreated controls. Significant changes in apoptotic activity were observed in all agents tested in both the T24 and the TCCSUP cells. CONCLUSIONS: Selective COX-2 inhibition, using the well-tolerated and commercially available Rofecoxib (VIOXX) and specific COX 1 and 2 inhibitors, reduced the growth of human bladder cancer in vitro by apoptotic mechanisms. Further in vivo and human studies are warranted to evaluate the safety and clinical utility of this agent in patients with bladder cancer.

Pediatric testicular tumors: contemporary incidence and efficacy of testicular preserving surgery.

PURPOSE: Testicular tumors in the pediatric population are fundamentally distinct from their adult counterparts. We reviewed a contemporary single series from a large pediatric health science center. We also examined our experience with testis conserving surgery and then used it to develop a preoperative management algorithm. MATERIALS AND METHODS: A retrospective review was performed of all testicular tumors at a single institution from 1984 to 2002. Data were compiled using the American Academy of Pediatrics testis tumor registry data collection form. We further examined partial orchiectomies for indications and outcomes with respect to cancer control and testicular viability. RESULTS: A total of 51 primary testicular lesions were identified. Patient age was prenatal to 16 years with a scrotal mass the most common presentation (81%). Mature teratoma, rhabdomyosarcoma, epidermoid cyst, yolk sac and germ cell tumors accounted for 43%, 26%, 10%, 8% and 6% of cases, respectively. This distribution was markedly different from the last reported American Academy of Pediatrics data base. Organ preserving surgery was planned and achieved in 13 cases. All surgeries were successful with respect to cancer control and testicular preservation. CONCLUSIONS: We believe that the higher incidence of teratoma is more representative of this population and yolk sac tumor is a minority diagnosis. The single institution review eliminates the interinstitutional referral heterogeneity that may have skewed larger data bases. Furthermore, the concept of testicular preserving surgery becomes an attractive option since we present its safety and efficacy. The management algorithm should facilitate the preoperative decision to perform less radical surgery and help preserve testicular tissue.

[Uterine and ovarian metastases 28 years after the discovery of breast cancer]. / Métastases utérines et ovariennes 28 ans après la survenue d'un cancer du sein.

INTRODUCTION: Breast cancer seldom leads to uterine metastases, but more frequently spreads to the ovaries. OBSERVATION: A 72 year-old woman treated 28 years earlier for a breast cancer (conservative treatment and ovarian castration through radiotherapy) presented with metrorrhagia. The hysteroscopy and uterine curettage were normal. Three months later she presented with bone pains and pain along the course of the femoral nerve. The clinical examination revealed the existence of left axillary and sub-clavicle adenopathies. A biopsy of the lymph nodes showed a lobular adenocarcinoma with positive hormonal receptors. The clinical and biological state of the patient improved under treatment with tamoxifen and aredia. Eight months later the patient complained of pelvic pains. The ultrasound examination showed a pelvic tumour situated at the fundus of an enlarged uterus, as well as peritoneal effusion. The patient underwent a total hysterectomy and multiple biopsies that revealed diffuse metastases of a lobular adenocarcinoma spreading to the neck and the body of the womb, the mesosalpinx, the left ovary and the epiploon. The patient died less than a year after the first symptoms had appeared. DISCUSSION: Uterine metastases of extrapelvic origin are rare. Breast cancer is the first cause of this dissemination. It is generally invasive, lobular, and frequently spreads to the ovaries. In the case reported here, what is remarkable is the exceptionally long period between the discovery of a breast cancer and the apparition of metastases. Hence, in order to detect a primary or secondary ovarian or uterine cancer, it is important to emphasize the necessity of systematic pelvic examination in patients treated for breast cancer.

The role of thoracotomy in managing postchemotherapy residual thoracic masses in patients with nonseminomatous germ cell tumours.

OBJECTIVE: To evaluate the clinical outcome and identify prognostic variables in patients with nonseminomatous germ cell tumours undergoing postchemotherapy thoracotomy for residual masses, as the role of this procedure is controversial. PATIENTS AND METHODS: Of 385 patients who underwent postchemotherapy retroperitoneal lymph node dissections between 1988 and 1998, 105 also had 130 thoracotomies. The clinical presentation, chemotherapy regimens, marker status, primary tumour histology, pathology of all resected masses, and clinical outcome of these 105 patients were analysed. RESULTS: The overall discordance rate for synchronous thoracic and retroperitoneal masses was 28%; that for asynchronous thoracic and retroperitoneal masses was 57%. Independent prognostic factors for residual thoracic teratoma or cancer were teratoma (mature or immature) in the primary tumour or retroperitoneal teratoma or cancer. Although three of 12 patients with residual thoracic cancer remained with no evidence of disease, residual thoracic cancer is an independent prognostic factor (P < 0.001) against disease-free survival. CONCLUSION: Postchemotherapy thoracotomy yields important prognostic information, and is therapeutic for most patients with teratoma and a subset with residual viable cancer. The prognostic criteria predictive of fibrosis are not sufficiently accurate to omit resection of residual thoracic masses.

Low-volume nodal metastases detected at retroperitoneal lymphadenectomy for testicular cancer: pattern and prognostic factors for relapse.

PURPOSE: To determine the incidence, pattern, and predictive factors for relapse in patients with low-volume nodal metastases (stage pN1) at retroperitoneal lymphadenectomy (RPLND) and identify who may benefit from chemotherapy in the adjuvant or primary setting. PATIENTS AND METHODS: Fifty-four patients with testicular nonseminomatous germ cell tumor had low-volume retroperitoneal metastases (pathologic stage pN1, 1997 tumor-node-metastasis classification) resected at RPLND, 50 of whom were managed expectantly without adjuvant chemotherapy. The dissection was bilateral in 12 and was a modified template in 38 patients. Retroperitoneal metastases were limited to microscopic nodal involvement in 14 patients. Follow-up ranged from 1 to 106 months (median, 31.4 months). RESULTS: Eleven patients (22%) suffered a relapse at a median follow-up of 1.8 months (range, 0.6 to 28 months). The most frequent form of recurrence was marker elevation in nine (18%) patients. Persistent marker elevation after orchiectomy and before retroperitoneal lymphadenectomy was a significant independent predictor of relapse (relative risk, 8.0; 95% confidence interval, 2.3 to 27.8; P =.001). Four of five (80%) patients with elevated markers (alpha-fetoprotein alone in three, alpha-fetoprotein and beta human chorionic gonadotropin in one) suffered a relapse, compared with seven of 45 (15.6%) patients with normal markers. CONCLUSION: Clinical stage I and IIA patients with normal markers who have low-volume nodal metastases have a low incidence of relapse and can be managed by observation only if compliance can be assured. In contrast, patients with elevated markers before retroperitoneal lymphadenectomy have a high rate of relapse and should be considered for primary chemotherapy.

[Treatment of genital infections in gynecology]. / Traitement des infections génitales en gynécologie.

Choice of antimicrobial agents and length of therapy of infections of the female genital tract and chemotherapy are presented with particular mention to their side effects. Clinical approach and antibiotic regimens of pelvic inflammatory diseases are discussed.