Determination of strontium radioisotopes in routine and emergency samples.

We present the radioanalytical strategies used for the determination of strontium radioisotopes in routine and emergency samples. While in routine monitoring, the main goal is to achieve limits of detection as low as possible. In emergency, priority is given to the rapid procurement of data about a contamination. The parameters accuracy, precision and detection limit of the radiochemical methods are shown. We present the results obtained over the past 22 years in proficiency tests and in the analysis of reference materials.

Isotopic signatures of plutonium and uranium at Bikar atoll, northern Marshall Islands.

We present plutonium (Pu) and uranium (U) isotopic fingerprints (or signatures) in environmental samples collected at Bikar Atoll. Bikar is the second -most northern atoll of the Republic of the Marshall Islands, and therefore an important reference point to evaluate the extension of the regional fallout from the Pacific Proving Grounds (PPG) in Bikini and Enewetak Atolls. Previous studies have shown that regional fallout from atmospheric nuclear weapon testing (NWT) in Bikini and Enewetak has resulted in elevated levels of fallout radionuclides in this atoll. In order to optimally interpret the isotopic fingerprints, we compare our results with data obtained in eleven certified reference materials, representing different contamination sources. As well as 238Pu, 239Pu, 240Pu, 241Pu, 238U and 235U, this study also encompasses less commonly reported radionuclides such as 242Pu, 244Pu and 236U. We show the importance of combining numerous fingerprints for improved assessment of the source of a nuclear contamination. In samples from Bikar, Pu and U isotope ratios were found to vary within narrow ranges. Pu and U fingerprints suggest that regional fallout from the Castle Bravo test in March 1954 was the main source of the contamination. This was further confirmed by two different age dating approaches that estimated 1954 as the year of the contamination. We demonstrate that use of an exponential function to approximate the yield of heavy radionuclides in thermonuclear explosions with increasing mass is a valid approach for estimating the age of a contamination. We show that, if sufficient radionuclide activity concentration measurement results with low uncertainties are available, this method is robust.

Radionuclides in sediments of the Aare and Rhine river system: Fallouts, discharges, depth-age relations, mass accumulation rates and transport along the river.

The Aare-Rhine river system with its four nuclear power plants on the banks of these rivers and with its intermediate lakes and reservoirs provide the unique chance to analyze the input of radioactivity into the system thereby furnishing information on the sources, to analyze the transport within the sediment and along the rivers, and to refine unsupported 210Pb dating validated by known discharge maxima. At three locations (Lake Biel, Klingnau Reservoir, old branch of the Rhine) in the Aare and Rhine rivers system downstream of the older nuclear power plants (NPPs) Mühleberg and Beznau, the vertical distributions of 137Cs, 210Pb, 214Pb, 214Bi, 40K, 7Be, 239Pu, 240Pu, 241Am, and 237Np in sediment cores were determined. Depth-age relations using the excess 210 Pb were established with the raw and with the piecewise Constant Rate Supply (CRS) models. A comparison of the piecewise CRS method with the imprints of known discharges showed differences of up to two years. Besides typical 137Cs signals (about 100 Bq∙kg-1) from the atmospheric nuclear weapons testing (NWT) and the Chernobyl fallouts, imprints of known 137Cs discharges (10-70 Bq∙kg-1) from the NPPs were found in the sediments. The 237Np distributions (6-10 Bq∙kg-1) essentially follow the 137Cs NWT distributions. In the sediment downstream the NPP Mühleberg (Lake Biel) a239Pu distribution (<3 Bq∙kg-1) was found, which was solely due to the NWT fallout. Downstream the NPP Beznau (Klingnau Reservoir and an old branch of the Rhine), besides the NWT distribution, also imprints of 239Pu discharges (up to 7 Bq∙kg-1) were found within the time interval 1963 to 1986.240Pu/239Pu ratios revealed that the burn-up times of the nuclear fuel in the NPP (235U enrichment of 3.5%), from which the discharges stem, should be about 1 year or less. A comparison between the calculated and the measured 137Cs/239Pu ratio revealed no large discrepancies for the Lake Biel and Rhine positions, but in the Klingnau distribution, the calculated 137Cs/239Pu ratio is one order of magnitude larger than the measured one. The reason could be either a natural uranium research reactor as the source, or strong, short-range 239Pu precipitation after the discharge from the Beznau NPP. The largest 239Pu peak in the Rhine sediment (1968/70) corresponds to no major peak in the Klingnau sediment. For the NPP Mühleberg discharge of 1982 the ratio of the 137Cs deposition in sediments from Lake Biel, Klingnau Reservoir and the Rhine river is about 1 : 0.5 : 2.9. For the 1977/78 239Pu deposition the ratio is 1 : 0.02, for the Klingnau Reservoir and the Rhine sediments, respectively. These numbers indicate a long-range transport of Cs and a rather short-range transport of Pu.

Dating of recent sediments from Lago Maggiore and Lago di Lugano (Switzerland/Italy) using 137Cs and 210Pb.

This paper presents the results of 137Cs and 210Pb dating of sediments from the northern and western basins of Lago Maggiore and the southern basin of Lago di Lugano. Vertical distributions of 137Cs in sediment cores taken in 2017/18 were compared to those of the sediment cores taken almost two decades ago at the same positions. This comparison showed that 137Cs peaks do not alter their shape significantly over time and 137Cs remains a reliable time-marker for many decades. 210Pb dating using for the first time the piecewise "constant rate supply" (CRSPW) model constrained with 137Cs time-markers is performed for sediment cores of Lago Maggiore and Lago di Lugano. "Event-linked" mass accumulation rates (MARs) were derived from the CRSPW model. In combination with the dry bulk density, organic matter content, 40K and 210Pb activity concentrations, these "event-linked" MARs were used for the identification of one or more event layers (turbidites, detrital layers) in 1-cm thick sediment samples. "Continuous" mean MARs which are independent of the event layers were estimated: in Lago Maggiore sediment cores they are 0.066-0.090 g cm-2 yr-1; in Lago di Lugano they vary in the range of 0.032-0.057 g cm-2 yr-1 with higher values in the time interval 1963-1986 as compared to 1986-present.

Clinical and diagnostic features of trochanteric tuberculosis.

Trochanteric tuberculosis is a very rare localization of musculo-skeletal tuberculosis. The diagnosis is difficult and is often made in a late stage. The authors describe five cases of trochanteric tuberculosis. The mean age of patients was 46.6 years. Time to diagnosis was long (7.6 months on average). The tuberculosis was plurifocal in all cases. Diagnosis was based on positive Lowenstein culture in one case, on the presence of caseum granuloma in one case and through a pathognommonic manifestation in one case. For the remaining two cases, diagnosis was established on clinical and paraclinical arguments. The patients recovered after medical treatment alone.

-643C > T RANKL gene polymorphism is associated with osteoporosis in Tunisian postmenopausal women.

OBJECTIVES: The dynamic nature of the skeleton is achieved by a remodeling process. Receptor activator of nuclear factor kappa B (RANK) ligand (RANKL) stimulates bone resorption by activating RANK signaling. Therefore it is considered as a candidate gene regulating susceptibility to osteoporosis. In the current study, we have investigated the association between the RANKL gene -693G > C and -643 C > T polymorphisms and bone mineral density (BMD) in a population of postmenopausal Tunisian women. METHODS: Polymorphic sites in RANKL gene (rs9533155 -693G > C and rs9533156 -643 C > T polymorphisms) were determined using PCR-RFLP analysis in 566 postmenopausal Tunisian women. All statistical analysis were examined by SPSS software. RESULTS: We have detected a significant difference in lumbar spine and hip BMD for -643C > T genotypes. For -693G > C genotypes, a significant difference was detected only in hip BMD. The distribution of -643C > T genotypes and alleles between three groups (osteoporotic, osteopenic and normal women) revealed a significant association of the TT genotype with development of osteoporosis (p = 0.01; odds ratio 2.15), although for the -693G > C polymorphism, no significant results were found. CONCLUSION: We have demonstrated the association of the -643C > T polymorphism with BMD variation and osteoporosis risk in postmenopausal Tunisian women.

Long-term behavior of (90)Sr and (137)Cs in the environment: Case studies in Switzerland.

We present long-term records of the (137)Cs and (90)Sr activity concentrations in soil, grass and milk from two lowland and two alpine pastures of Switzerland. The data is used for better understanding the long-term behavior of these radionuclides in the environment. Transfer factors between compartments are used as qualitative indicators of the magnitude of transfer and as a way to compare different elements (e.g. Cs and Sr) in similar conditions. The long-term behavior was quantified by means of the effective half-life which integrates all processes that cause a decrease of activity in a given medium such as leaching, fixation, erosion and radioactive decay. Our study shows that (90)Sr is more likely transferred from alpine soil to grass than (137)Cs. This is explained by a stronger fixation of Cs in the soils. We observed higher transfers of (90)Sr to grass in soils with lower Ca concentrations, and vice versa. In contrast, the transfer of (137)Cs to grass was not affected by the variations of the K content in the soil. We provide evidence that shows that (137)Cs, after intake by dairy cattle, is more likely transferred to milk than (90)Sr. However, as the (90)Sr and Ca transfers to milk are influenced by parameters/processes that were not taken into account in our study, our result cannot be entirely validated. The effective half-lives of (137)Cs and (90)Sr in soil, grass and milk corresponded with previous estimates in alpine soils. We have found that processes other than radioactive decay are responsible for a major decrease of the (90)Sr activity in soil. For (137)Cs, on the other hand, radioactive decay is among the most relevant process. Our data shows to be of interest in studying the trends of behavior of radionuclides in alpine regions.

Dating of sediments from four Swiss prealpine lakes with (210)Pb determined by gamma-spectrometry: progress and problems.

In this paper the most important problems in dating lake sediments with unsupported (210)Pb are summarized and the progress in gamma-spectrometry of the unsupported (210)Pb is discussed. The main topics of these studies concern sediment samples preparation for gamma-spectrometry, measurement techniques and data analysis, as well as understanding of accumulation and sedimentation processes in lakes. The vertical distributions of artificial ((137)Cs, (241)Am, (239)Pu) and natural radionuclides ((40)K, (210,214)Pb, (214)Bi) as well as stable trace elements (Fe, Mn, Pb) in sediment cores from four Swiss lakes were used as examples for the interpretation, inter-comparison and validation of depth-age relations established by three (210)Pb-based models (CF-CSR, CRS and SIT). The identification of turbidite layers and the influence of the turbidity flows on the accuracy of sediment dating is demonstrated. Time-dependent mass sedimentation rates in lakes Brienz, Thun, Biel and Lucerne are discussed and compared with published data.

Polymorphisms in VDR gene in Tunisian postmenopausal women are associated with osteopenia phenotype.

OBJECTIVES: Osteopenia is characterized by intermediate values of bone mineral density (BMD) as compared to normal and osteoporotic subjects. BMD, a surrogate phenotype for osteoporosis, is influenced in part by genetic factors. Among the genes associated with BMD, the vitamin D receptor (VDR) was the first gene studied as a potential candidate associated with BMD in adult and postmenopausal bone loss. However, results are controversial. METHODS: To determine whether VDR polymorphisms ApaI and TaqI are associated with BMD, osteopenia, osteoporosis and low-impact fracture risk in North Africans, these genotypes were analyzed in 566 postmenopausal Tunisian women. RESULTS: In postmenopausal Tunisian women, the GT ApaI genotype seems to be protective against osteoporosis development (p = 0.02; odds ratio = 0.54). Moreover, the presence of the combined GT/TT genotype of ApaI and TaqI polymorphisms is more frequent in normal BMD women than in osteoporotic women (p = 0.00; odds ratio = 0.41). Interestingly, the GG ApaI genotype is associated with osteopenia development (p = 0.02; odds ratio = 1.86) and also the TT TaqI polymorphism (p = 0.02; odds ratio = 1.53). The GG ApaI genotype is associated with a three times risk of vertebral fracture. CONCLUSIONS: The ApaI polymorphism showed an association with osteopenia and low-impact vertebral fracture incidence but not with osteoporosis. The TaqI polymorphism is associated specifically with the osteopenia phenotype. The presence of the two polymorphisms increases the risk to develop osteopenia in postmenopausal Tunisian women. Osteopenia seems to be genetically determined. However, osteoporosis is the result of interaction between genetic and environmental factors.

Increased urinary type II collagen C-telopeptide levels in Tunisian patients with knee osteoarthritis.

UNLABELLED: Osteoarthritis is characterized by a progressive degeneration of articular cartilage and loss of joint function. Clinical assessment of osteoarthritis is hampered by the lack of accurate measures of disease and disease progression, especially during the early stage. BACKGROUND: To investigate urinary C-telopeptide fragments of type II collagen (CTX-II) levels in knee osteoarthritis in the Tunisian population compared with controls and to assess the association between this biomarker and radiological signs. METHODS: One hundred and twenty five female patients with knee osteoarthritis, aged 53.6 +/- 7.6 years with disease duration of 3.6 +/- 3.8 years and 57 female age-matched controls underwent Lyon Schuss X-ray exams. Two experienced readers independently measured the joint space width (JSW) and classified each knee for severity using the Kellgren/Lawrence scale. The urinary concentration of CTX-II was measured by a competitive ELISA. RESULTS: The levels of urinary CTX-II were significantly higher in knee osteoarthritis patients compared with controls (323.98 vs 218.04 microg/mol creatinine). A weak and non significant association between the CTX-II level and JSW was found. The significant correlations were observed between age and CTX-II in both groups and between BMI and CTX-II only in controls. CONCLUSIONS: Analysis of CTX-II in urine samples of Tunisian patients with knee osteoarthritis provided a sensitive method to detect increased degradation of collagen type II in patients with osteoarthritis.

[Onset of Crohn's disease induced by etanercept therapy: a case report]. / Le cas clinique du mois. Maladie de Crohn induite par l'Etanercept: à propos d'une nouvelle observation.

A 27-year-old-man was diagnosed as having ankylosing spondylitis (AS) in 2003 and received a treatment by etanercept. Typical symptoms of active Crohn's disease (CD) developed 11 months after initiation of etanercept therapy. At colonoscopy, lesions compatible with CD were found endoscopically and histologically. Etanercept was interrupted and CD responded to standard treatment. A switch to infliximab was decided to treat a flare up ofAS. New onset CD may be considered an immune mediated injury induced by etanercept, but the causative role of the latter has not been demonstrated at this stage.

An extensive hemimelic polyostotic fibrous dysplasia: a case report.

We report a new case of polyostotic fibrous dysplasia (FD). A 26-year-old woman was referred to our department complaining of pain in her left arm. She had suffered for tow fractures in left leg and arm previously. Plain radiographs showed osteolytics lesions at the left humerus and radius. Histological examination of the surgical specimens showed FD. She has beneficed with zoledronic acid perfusion.

[Sciatica in a Tunisian teenager: pelvic hydatid cyst]. / Lombosciatique chez un adolescent tunisien. Kyste hydatique pelvien.

The purpose of this report is to describe the case of a 13-year-old boy presenting typical sciatica leading to the discovery of primary pelvic hydatid cyst extending to the ischiatic bone. Diagnosis was suspected based on echography and magnetic resonance imaging and confirmed by surgical exploration.

Back pain caused by a pseudo-tumorous vertebral collapse: atypical presentation of primary vertebral hydatidosis.

Hydatidosis, also known as echinococcosis, is a rare but serious parasitic disease in endemic areas. Primary spinal location is extremely rare. This case report describes a rare instance of hydatid cyst that caused severe and progressive low-back pain and neurologic dysfunction. Spine MRI showed a unique vertebral collapse of Th12 body with multicystic lesions filling the spinal canal. In addition, hydatidosis serodiagnostic test was positive at 1/725. Treatment depended on the actual surgical removal of the cysts. Surgery consisted in excision and extirpation of the cysts, associated with decompressive laminectomy. The diagnosis was confirmed on the basis of histological results. No coincidental hydatid visceral involvement was found. Antihelminthic drugs (Albendazole) were promptly given before surgery for a long period. The outcome was satisfactorily marked by total regression of the motor deficit and sphincter disorders.

Sweet's syndrome in a patient with rheumatoid arthritis, Sjögren's syndrome and lymph node tuberculosis.

Sweet's syndrome (SS) is an acute neutrophilic dermatosis characterised by abrupt onset of fever, leukocytosis and cutaneous eruption, with dermal neutrophilia on skin biopsy. Most cases are idiopathic but SS can be associated with various affections, especially neoplastic, inflammatory and infectious diseases. The authors report the case of an SS occurring in a patient with a known rheumatoid arthritis associated with a secondary Sjögren's syndrome, with incidental finding of concurrent lymph node tuberculosis. In case of SS, an associated disease (malignant, inflammatory or infectious diseases) must imperatively be searched for, knowing that two or more of these affections can coexist.

Spine fracture in patient with ankylosing spondylitis: A case report.

Spinal fractures in patients with ankylosing spondylitis may be the result of minor trauma. These fractures may lead to severe neurological deficits, and they are difficult to detect using standard radiography. Often, CT-scans and MRI are required for diagnosis.