Environmental-Impact Assessment of Natural Radioactivity Around a Traditional Mining Area in Al-Ibedia, Sudan.

Recently, in the Sudan, traditional gold mining has been growing rapidly and has become a very attractive and popular economic activity. Mining activity is recognized as one of the sources of radioactivity contamination. Hence, the radioactivity concentration and radiological hazard due to exposure of radionuclides (226)Ra, (232)Th, and (40)K were evaluated. The measurements were performed using gamma-ray spectrometry with an NaI (Tl) detector. The results show that (226)Ra, (232)Th, and (40)K activity concentration ranged from 2.66 to 18.47, 9.20 to 51.87, and 0.17 to 419.77 Bq/kg with average values of 7.54 ± 4.91, 20.74 ± 11.29, and 111.87 ± 136.84 Bq/kg, respectively. In contrast, (222)Rn in soil, (222)Rn in air, and (226)Ra in vegetables along with radiation dose were computed and compared with the international recommended levels. Potential radiological effects to miners and the public due to (226)Ra, (232)Th, (40)K, and (222)Rn are insignificant. (226)Ra transferred to vegetables appears to be negligible compared with the allowable limit 1.0 mSv/year set by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The average value of the annual gonadal dose equivalent (AGDE) is lower than the global average of 300 µSv/year (UNSCEAR 2000). However, some locations exhibit values >300 µSv/year. To the best of our knowledge, so far there seems to be no data regarding radioactivity monitoring in traditional mining areas in the Sudan.

Optimisation of T2 and T2* sequences in MRI for better quantification of iron on transfused dependent sickle cell patients.

This work aimed to investigate the effect of different shim techniques, voxel sizes, and repetition time (TR) on using theT2 and T2* sequences to determine their optimum settings to investigate the quantification of iron in transfused dependent sickle cell patients. The effect of each of these parameters was investigated on phantoms of different Gadolinium (Gd) concentrations, on 10 volunteers and 25 patients using a1 5T MRI Philips scanner. No significant difference between the three shim techniques was noticed in either T2 or T2* sequence measurements. Pixel sizes of 1 × 1 and 2 × 2 mm provided optimum results for T2 measurements. At 1 × 1 mm pixel size the T2* measurements experienced less error in measurements than the size of 2.5 × 2.5 mm used in the literature. Even though the slice thickness variation did not provide any changes in T2 measurements, the 12 mm provided optimum T2* measurements. TR variation did not yield significant changes on either T2 or T2* measurements. These results indicate that both T2 and T2* sequences can be further improved by providing more reliable measurements and reducing acquisition time.

Long Term Outcomes of Liver Transplantation For Patients With Autoimmune Hepatitis.

BACKGROUND: Autoimmune hepatitis (AIH) is a rare indication for liver transplantation (LT). Data on the long-term outcomes of living-related LT for AIH are limited and inconsistent. The present study aimed to assess the long-term outcomes of deceased donor LT (DDLT) and living donor LT (LDLT) for AIH. METHODS: All patients who received transplants for AIH-related cirrhosis from 2001 to 2018 were included in this study. RESULTS: Seventy-four patients (31 male, 43 female) received LT. The average follow-up was 7.9 ± 6.9 years (median = 7.2 years), average age was 34.3 ± 13.8 years, and average Model for End-Stage Liver Disease (MELD) score was 23.6 ± 8.5. Thirty-six (49.3%) patients received a graft from a living donor, and 83% of patients were maintained on steroids. The 1-, 3-, 5-, and 10-year survival rates of patients were 91%, 89%, 87%, and 82% and of grafts were 89%, 88%, 86%, and 76%, respectively. In univariate analysis, MELD score (odds ratio [OR], 1.08; 95% confidence interval [CI], 1.01-1.17; P = .028), donor age (OR per 5 years, 1.45; 95% CI, 1.07-2.02; P = .021), donor type (OR LDLT vs DDLT, 0.19; 95% CI, 0.04-0.67; P = .017), and renal function (OR glomerular filtration rate <60 vs ≥60 mL/min/m2, 7.41; 95% CI, 1.88-31.25; P = .004) were significant predictors of graft survival; however, none of the factors remained significant in multivariate analysis. CONCLUSION: We have shown the highest reported long-term survival rates in LT for AIH, including a large number of patients who underwent LDLT. Standardized management and immunosuppressive therapy, including the maintenance of a low-dose steroid protocol, may have contributed to this outcome.

Investigation of natural radioactivity levels in water around Kadugli, Sudan.

Surface water from Miri Lake and groundwater from around Kadugli (West-Central Sudan) obtained by means of hand-pumps was analysed for (238)U, (226)Ra, (222)Rn, and (232)Th activity concentrations. The surface water showed very low levels of radionuclide concentrations: <1.0-7.5, 8.5-16.5, <1.6, and <0.1-0.39 mBq L(-1) for (238)U, (226)Ra, (222)Rn, and (232)Th, respectively. Groundwater revealed a significant amount of natural radioactivity (16.1-1720, 7.7-14.3, 3000-139,000, <0.1-39 mBq L(-1)) respectively. The overall annual effective dose was below the WHO reference dose level of 0.1 mSv yr(-1) except in one groundwater sample with an associated dose of 0.7 mSv yr(-1).

RADIOLOGICAL HAZARD INDICES OF GRANITIC ROCKS USED FOR THE CONSTRUCTION OF BUILDINGS FROM NUBA MOUNTAINS SUDAN.

This study was conducted to assess the level of radioactivity and the radiation hazards associated with granite rocks used for construction of buildings. The measurement of radioactivity content of the rock samples was performed with gamma-spectrometry equipped with Nal (TI) detector. From the results obtained in this study the average activity concentrations of 226Ra, 232Th and 40K were 20.64, 30.50 and 295.19 Bq kg-1, respectively. The absorbed dose rate in air at 1 m above ground level, the annual effective dose and the gamma index were determined with the aim to assess the possible radiological impact on inhabitants of dwellings built using such rocks. The mean value of the absorbed dose rate, the annual effective dose and the gamma index (Iγ) was 36.36 nGy h-1, 40.79 µSv y-1 and 0.51 µSv y-1, respectively. Radium equivalent activities, and external and internal hazard indices, were also calculated. These data indicated that the area of study lies within areas recognized as normal background radiation and the granite rocks are safe to be used as building material and other structural purposes.

Effect of Downstaging and Bridging of Hepatocellular Carcinoma on Survival Following Liver Transplant: A Single Center Experience.

OBJECTIVES: Hepatocellular carcinoma is among the leading causes of cancer death. The Milan criteria are the first and most widely used criteria for selecting patients with hepatocellular carcinoma for a good transplant outcome. Studies have shown that patients with hepatocellular carcinoma outside the Milan criteria have good outcomes if they are successfully downstaged before transplant. We report our experience with locoregional therapy for hepatocellular carcinoma, either for bridging or for downstaging prior to transplant. MATERIALS AND METHODS: We retrospectively reviewed the electronic charts and our institutional database for adult patients diagnosed with hepatocellular carcinoma between 2001 and 2016. We recorded patient demographics, the type of transplant (living donor or deceased donor), radiologic findings, the type of locoregional intervention, and overall survival. RESULTS: A total of 642 adult liver transplants were performed during the study period (290 living donor and 352 deceased donor), of which 158 (24.6%) were conducted in patients with hepatocellular carcinoma (104 men and 54 women). Hepatocellular carcinoma was associated with hepatitis C in 80 patients (51%), hepatitis B in 44 (28%), and was cryptogenic in 13 (8%). Patients were grouped based on their radiologic staging (within Milan, within and beyond University of California, San Francisco), and subsequently described by whether they received locoregional therapy. Median survival and mortality were noted. Kaplan-Meier survival curves showed no statistically significant difference for patients within the Milan criteria, with or without locoregional therapy (P = .5). When patients within the Milan criteria were combined with patients within the University of California, San Francisco criteria, those who were downstaged from outside the latter criteria had similar survival. CONCLUSIONS: We demonstrate that carefully selected patients beyond the Milan criteria and even beyond the University of California, San Francisco criteria can be bridged and downstaged successfully for liver transplant.

Quinine for the treatment of uncomplicated Plasmodium falciparum malaria in eastern Sudan.

An observational clinical trial was conducted in New Halfa, eastern Sudan, in November and December 2003. Sixty-two patients with uncomplicated Plasmodium falciparum malaria were treated with oral quinine (10 mg/kg thrice daily for 7 d); 47 (76%) of these patients were followed-up to day 28, and 5 (10.6%) of them appeared to have late treatment failures. The parasitological failures were early R1 in two (4.3%) patients and late R1 in three (6.4%) patients. The reappearance of parasites in three of these five patients were true recrudescences rather than a re-infection, based on genetic evidence. The present results and those of earlier investigations indicate that the response to quinine in this area may be faltering.

Impact of fluoride and other aquatic parameters on radon concentration in natural waters.

Radon (222Rn) accumulation in water in relation to stable elements was studied for the purpose of determining factors influencing the transfer of 222Rn to and from water. In 72 groundwater samples, 222Rn and about 70 analytical parameters were analysed using radiometric and ICP-MS techniques. Using multivariate statistics (partial least squares), it was observed that 222Rn has a positive correlation with fluoride and uranium. The correlation with fluoride was further investigated by a laboratory time-scale experiment to measure the emanation of 222Rn from water as a function of fluoride, pH and carbonate. The transfer of 222Rn from water was measured by continuous monitoring in air in a closed loop set-up. It was observed that fluoride in water adhere or trap 222Rn preferably in acidic water (pH 3). It is suspected that natural physical processes (such as diffusion and microbubble phenomenon) are less effective to transport 222Rn in the presence of fluoride.

Radiation survey of aircraft and heavy machinery scrap.

This study was conducted primarily to survey aircraft and heavy machinery at 30 locations within Khartoum State using handheld radiation survey meters to detect and identify any radiation sources that might be present and to estimate radiation dose levels. The survey has resulted in detection of 16 sealed sources of (90)Sr and one of (226)Ra in aircraft scrap. Of course, (90)Sr sources are used in military aircraft as temperature sensors while (226)Ra is used for indicating fuel levels. These sources were found intact without spreading radioactivity contamination; however, none was detected in heavy machine scrap. The levels of radiation dose measured at 0.1m from the source fall within the range of 25.1-40.2 µSv/h with an average value of 33.52 ± 4.06 µSv/h. These orphan sources have been separated from the scrap, tested for possible leakage, conditioned and stored in waste management facility. The result of this study has revealed without doubt that the scrap constitute a serious source of public exposure and highlights the importance of legislation making radiation monitoring of scrap in the country mandatory before it is sold to metal industry for reprocessing.

Progressive seizures in a patient with congenital coagulopathies.

Dural arteriovenous fistula (DAVF) is a rare complication of cerebral venous sinus thrombosis (CVST). DAVFs develop as a result of direct arterial to venous sinus communications evolving in response to an occluded sinus. The authors present a patient with Down's syndrome who developed progressive, uncontrolled seizures and chronic CVST secondary to factor V Leiden deficiency. Brain MRI and computerised tomographic venography revealed a complex secondary DAVF, which once embolised resulted in a dramatic reduction in seizures and improvement in the clinical state. DAVFs should be considered as a potential complication in patients with persistent features of CVST.

Survey of computed tomography technique and radiation dose in Sudanese hospitals.

The purpose of this study was to survey technique and radiation absorbed dose in CT examinations of adult in Sudan and to compare the results with the reference dose levels. Questionnaire forms were completed in nine hospitals and a sample of 445 CT examinations in patients. Information on patient, procedure, scanner, and technique for common CT examinations were collected. For each facility, the radiation absorbed dose was measured on CT dose phantom measuring 16 cm (head) and 32 cm (body) in diameter and was used to calculate the normalized CT air kerma index. Volume CT air kerma index (CVOL), CT air kerma-length product (PKL,CT) values were calculated using the measured normalized CT air kerma index and questionnaire information. The effective dose, E estimates was determined by using PKL,CT measurements and appropriate normalized coefficients. Assuming the sample to offer a fair representative picture of CT practice patterns in Sudan, the mean CVOL and PKL,CT values were comparable or below the reference doses: 65 mGy and 758 mGy cm, respectively at head CT; 11.5 mGy and 327 mGy cm, respectively at chest CT; 11.6 mGy and 437 mGy cm, respectively at abdominal CT; and 11.0 mGy and 264 mGy cm, respectively at pelvis CT. Estimated effective doses were 1.6, 4.6, 6.6 and 4.0 mSv, respectively. The study offered a first national dose survey and provided a mean for quality control and optimization of CT practice within the country.