SEED: An Operational Numerical Tool for Dosimetric Reconstruction in Case of External Radiological Overexposure.

ABSTRACT: In the event of a radiological accident involving external exposure of one or more victims and potential high doses, it is essential to know the dose distribution within the body in order to sort the victims according to the severity of the irradiation and then to take them to the most suitable medical facilities. However, there are currently few techniques that can be rapidly deployed on field and capable of characterizing an irradiation. Therefore, a numerical simulation tool has been designed. It can be implemented by a doctor/physicist pairing, projected within a limited time as close as possible to the irradiation accident and emergency response teams. Called SEED (Simulation of External Exposures & Dosimetry), this tool (dedicated to dose reconstruction in case of external exposure) allows a rapid modeling of the irradiation scene and a visual exchange with the victims and witnesses of the event. The user can navigate in three dimensions in the accident scene thanks to a graphical user interface including a "first person" camera. To validate the performance of the SEED tool, two dosimetric benchmarking exercises were performed. The first consisted in comparing the dose value provided by SEED to that given by a reference calculation code: MCNPX. The purpose of the second validation was to perform an experiment irradiating a physical dummy equipped with dosimeters and to reconstruct this irradiation using SEED. These two validation protocols have shown satisfactory results with mean difference less than 2% and 12% for the first and second exercises, respectively. They confirm that this new tool is able to provide useful information to medical teams in charge of dosimetric triage in case of a major external exposure event.

Physicochemical Variability and Biodiesel Potential of Seed Oils of Two Hibiscus sabdariffa L. Phenotypes.

Considerable interest is being focused on vegetable oils as fuel. Due to their characteristics being close to diesel and their renewable potential, studies recommend their use for agricultural applications. Hibiscus sabdariffa var. sabdariffa is widely studied for the nutritional properties of its calyces. Although the seeds of this species are known to be rich in fatty acids, their use is little known in Benin Republic. Similarly, a few studies have attempted to characterize the seeds of the green phenotype of this plant species. By following standard methods, the fatty acid profiles of oils extracted from the seeds of the two varieties (red phenotype, sabdariffa (HSS), and green phenotype, altissima (HSA)) of H. sabdariffa L. were established. A comparative study of their physicochemical properties was also performed to highlight their potential use as fuel. It follows that HSS seed oil is yellow while HSA seed oil is dark green. For the two varieties, values obtained for the kinematic viscosity (∼4 mm2/s), cetane number (∼55), and density (0.87 g/cm3) are in accordance with the U.S. and European standards. However, it is observed that HSA oil is significantly more acidic (23.10 ± 0.22 for HSS vs 18.20 ± 0.40 mg KOH/g oil for HSS) with a higher peroxide value (HSA: 0.280 ± 0.002 vs HSS: 0.140 ± 0.001). The major fatty acids are the following: palmitic (HSA: 27.09 vs HSS: 25.48%), oleic (HSA: 31.81 vs HSS: 35.21%), and linoleic (HSA: 31.43 vs HSS: 29.70%) acids. These fatty acid profiles give to the two oils calorific values (∼39.45 MJ/kg) lower than that of diesel but good oxidative stability and cold filter plugging. The two oils could be used as fuel oil, after their transesterification to improve their properties.

Activation of the NALP3 inflammasome is triggered by low intracellular potassium concentration.

Inflammasomes are Nod-like receptor(NLR)- and caspase-1-containing cytoplasmic multiprotein complexes, which upon their assembly, process and activate the proinflammatory cytokines interleukin (IL)-1beta and IL-18. The inflammasomes harboring the NLR members NALP1, NALP3 and IPAF have been best characterized. While the IPAF inflammasome is activated by bacterial flagellin, activation of the NALP3 inflammasome is triggered not only by several microbial components, but also by a plethora of danger-associated host molecules such as uric acid. How NALP3 senses these chemically unrelated activators is not known. Here, we provide evidence that activation of NALP3, but not of the IPAF inflammasome, is blocked by inhibiting K(+) efflux from cells. Low intracellular K(+) is also a requirement for NALP1 inflammasome activation by lethal toxin of Bacillus anthracis. In vitro, NALP inflammasome assembly and caspase-1 recruitment occurs spontaneously at K(+) concentrations below 90 mM, but is prevented at higher concentrations. Thus, low intracellular K(+) may be the least common trigger of NALP-inflammasome activation.

The SPRY domain of Pyrin, mutated in familial Mediterranean fever patients, interacts with inflammasome components and inhibits proIL-1beta processing.

The autoinflammatory disorders Muckle-Wells syndrome, familial cold urtecaria and chronic infantile neurological cutaneous and articular syndrome are associated with mutations in the NALP3 (Cryopyrin) gene, which is the central platform of the proinflammatory caspase-1 activating complex, named the inflammasome. In patients with another autoinflammatory disorder, familial Mediterranean fever (FMF), mutations in the SPRY domain of the Pyrin protein are frequently found. Recent evidence suggests that Pyrin associates with ASC, an inflammasome component, via its Pyrin domain, thereby halting the inflammatory response. This interaction, however, does not explain the effects of mutations of the SPRY domain found in FMF patients. Here we show that the Pyrin SPRY domain not only interacts with NALP3, but also with caspase-1 and its substrate pro-interleukin(IL)-1beta. Whereas a Pyrin knockdown results in increased caspase-1 activation and IL-1beta secretion, overexpression of the SPRY domain alone blocks these processes. Thus Pyrin binds to several inflammasome components thereby modulating their activity.

The estrogen-responsive B box protein: a novel enhancer of interleukin-1beta secretion.

The estrogen-responsive B box protein (EBBP) and Pyrin belong to a family of structurally related proteins. While mutations in the pyrin gene cause an autoinflammatory disease, the biological function of EBBP is unknown. In this study, we identified the proinflammatory cytokine interleukin-1beta (IL-1beta) as an EBBP-binding partner. Furthermore, caspase-1 and NACHT, LRR and Pyrin domain containing protein (NALP) 1, two components of the recently identified inflammasome, a platform for the activation of caspase-1, also interact with EBBP. These proteins bind to the RFP domain of EBBP, suggesting that this domain of so far unknown function is an important protein-binding domain. EBBP was secreted in a caspase-1-dependent manner from cultured cells, and its secretion was enhanced by IL-1beta. Vice versa, endogenous and overerexpressed EBBP increased IL-1beta secretion. These results provide evidence for a role of EBBP in innate immunity by enhancing the alternative secretion pathway of IL-1beta.

Inducible production of macrophage colony-stimulating factor (CSF-1) by malignant and normal human T cells.

The CEM-ON malignant T cell line and long-term cultured normal T cells can be induced to release CSF-1 in their culture supernatants. Chemical inducers (PMA + A23187) and, more interestingly, cytokines (tumor necrosis factor alpha (TNF alpha) and interleukin-1 alpha (IL-1 alpha)), as well as physiological (antigen + IL-2) or specific (anti-CD3 + IL-2 or PMA) stimuli, lead to rapid transient colony-stimulating factor-1 (CSF-1) gene expression and production of biologically active CSF-1. These data suggest that CSF-1 may play a role in the early phases of immune response.

Characteristics of pro-T ALL subgroups: comparison with late T-ALL. The Groupe d'Etude Immunologique des Leucémies.

A group of 30 acute lymphoblastic leukemias (ALL) with the early pro-T phenotype CD7+/cCD3+/CD1-/CD3-/CD4-/CD8-were identified among 103 newly diagnosed ALL with T-lineage markers (T-ALL). Pro T-ALL was more often observed in adults, and showed a lower incidence of hyperleukocytosis than more mature T-ALL. Mediastinal masses and polar acid phosphatase positivity in blast cells were however observed with the same frequency in pro T-ALL and late T-ALL, and rearrangements of both T-cell receptor (TCR) beta and gamma genes were observed in half the pro T-ALL cases tested. The expression of CD34, DR, and myeloid (My) markers was significantly more frequent in pro T-ALL than in late T-ALL, and these three features were strongly linked. TCR gene rearrangements were two to three times more frequent in CD34- and My-pro T-ALL. However, both CD34+ and My+ pro T-ALL showed an incidence of mediastinal masses and polar acid phosphatase positivity similar to this observed in CD34- and My- cases. This supports the assumption that both types of ALL indeed are engaged in the T-lineage, and confirms intracytoplasmic cCD3 as the earliest marker for this lineage. Moreover, CD34 appears to persist up to an early stage of T-cell maturation, where the cells retain myeloid potentiality. Loss of CD34 correlates with TCR-beta gene rearrangement and definitive commitment to the T lineage. Event-free survival analysis suggested a poorer outcome for pro T-ALL in adult patients.

Primary Epstein-Barr virus infection with clonal T-cell lymphoproliferation.

A case of fatal Epstein-Barr virus infection in a previously healthy girl who was first found to have severe infectious mononucleosis with spontaneous recovery is reported. Because an abnormal immune response to the virus persisted, the disease relapsed, manifesting in cutaneous and pulmonary lesions associated with hemophagocytic syndrome responsible for death. Pathologic findings were characterized by polymorphous atypical lymphoid infiltrate, prominent necrosis, and histiocytic hyperplasia. Lymphoid cells displayed CD8 phenotype and clonal T-cell receptor gene rearrangement. Viral genome was detected in lesions by Southern blot and located in nuclei of lymphoid cells by in situ hybridization. Pathologic findings suggested fatal infectious mononucleosis; however, phenotype and genotype favored a malignant diagnosis. Clonality was demonstrated to have arisen during primary infection. Virologic examination indicated that Epstein-Barr virus was a causative agent. Such a process belongs to the recently recognized spectrum of Epstein-Barr virus-related T-cell lymphoproliferative disorders that might overlap fatal infectious mononucleosis in patients who are especially vulnerable to the virus.

Occurrence of a T cell lymphoma in a patient with chronic myeloid leukemia treated with alpha interferon.

A patient treated by recombinant human alpha interferon for chronic myeloid leukemia developed a T cell lymphoma. The T cell lymphoma cells were demonstrated to be genotypically different from the chronic myeloid leukemia cells. The possible role of interferon therapy in stimulating T cell proliferation is discussed.

Study of living single cells in culture: automated recognition of cell behavior.

An automated system capable of analyzing the behavior, in real time, of single living cells in culture, in a noninvasive and nondestructive way, has been developed. A large number of cell positions in single culture dishes were recorded using a computer controlled, robotized microscope. During subsequent observations, binary images obtained from video image analysis of the microscope visual field allowed the identification of the recorded cells. These cells could be revisited automatically every few minutes. Long-term studies of the behavior of cells make possible the analysis of cellular locomotary and mitotic activities as well as determination of cell shape (chosen from a defined library) for several hours or days in a fully automated way with observations spaced up to 30 minutes. Short-term studies of the behavior of cells permit the study, in a semiautomatic way, of acute effects of drugs (5 to 15 minutes) on changes of surface area and length of cells.

Developmental rearrangement of cyanobacterial nif genes: nucleotide sequence, open reading frames, and cytochrome P-450 homology of the Anabaena sp. strain PCC 7120 nifD element.

An 11-kbp DNA element of unknown function interrupts the nifD gene in vegetative cells of Anabaena sp. strain PCC 7120. In developing heterocysts the nifD element excises from the chromosome via site-specific recombination between short repeat sequences that flank the element. The nucleotide sequence of the nifH-proximal half of the element was determined to elucidate the genetic potential of the element. Four open reading frames with the same relative orientation as the nifD element-encoded xisA gene were identified in the sequenced region. Each of the open reading frames was preceded by a reasonable ribosome-binding site and had biased codon utilization preferences consistent with low levels of expression. Open reading frame 3 was highly homologous with three cytochrome P-450 omega-hydroxylase proteins and showed regional homology to functionally significant domains common to the cytochrome P-450 superfamily. The sequence encoding open reading frame 2 was the most highly conserved portion of the sequenced region based on heterologous hybridization experiments with three genera of heterocystous cyanobacteria.

[Antibiotic sensitivity of 139 strains of Listeria serotyped by the National Reference Center in 1983]. / Etude de la sensibilité aux antibiotiques de 139 souches de Listeria sérotypées par le Centre National de Référence en 1983.

The susceptibility of 139 strains of Listeria towards eight antibiotics--penicillin, ampicillin, cephalotin, gentamicin, chloramphenicol, tetracycline, erythromycin and pefloxacin--was studied. All strains were susceptible to all antibiotics except pefloxacin. The lowest MIC (less than or equal to 0.5 mg/l) were obtained with penicillin, ampicillin, gentamicin and erythromycin. For tetracycline, cephalotin and chloramphenicol, MIC ranged from 0.5 to 16 mg/l. The MIC of pefloxacin varied from 4 to 16 mg/l.

Alternative splicing at the MEFV locus involved in familial Mediterranean fever regulates translocation of the marenostrin/pyrin protein to the nucleus.

Mutations in MEFV, a gene encoding a protein (marenostrin/pyrin) of unknown function, are associated with familial Mediterranean fever, a genetic condition characterized by febrile episodes of serosal inflammation. Based on its primary structure, this 781 residue protein is thought to function as a nuclear effector molecule. However, recent transient expression studies indicated a perinuclear cytoplasmic localization. Here, we describe the isolation and expression of a novel human MEFV isoform, MEFV-d2, generated by in-frame alternative splicing of exon 2. This transcript, expressed in leukocytes, predicts a 570 residue protein designated marenostrin-d2. To investigate differences in subcellular localization between the full-length protein (marenostrin-fl) and marenostrin-d2, while providing against the overexpression of transiently expressed proteins, we have generated CHO cell lines stably expressing these two isoforms fused to the green fluorescent protein. The localization pattern of marenostrin-d2 differs dramatically from that of marenostrin-fl. Marenostrin-fl is homogeneously distributed over the entire cytoplasm, whereas marenostrin-d2 concentrates into the nucleus. To map the critical domain(s) specifying these differences, deletion mutants have been generated. Deletion of the putative nuclear localization signals (NLS) does not alter the nuclear localization of marenostrin-d2 whereas, despite the lack of discernible NLS in the domain encoded by the exon 1-exon 3 splice junction, deletion of this domain indeed disrupts this localization. These data, which challenge the current domain organization model of marenostrin, strongly suggest that MEFV encodes a nuclear protein and raises the possibility that MEFV alternative splicing may control functions of wild-type and mutant marenostrin proteins by regulating their translocation to the nucleus.

Responses of subcultured rat aortic smooth muscle myocytes to vasoactive agents and KCl-induced depolarization.

We have developed a culture system in which a single-mass primary culture can be used for as long as 6 wk as a source of subcultured smooth muscle myocytes for the study of the changes of their shape upon addition of vasoactive agents (angiotensin, vasopressin, norepinephrine, and serotonin) and KCl depolarization. Responses of subcultivated myocytes were shown to be reproducible with time in primary culture before subculture and consistent with responses of thoracic aorta to the same agents. Effect of KCl depolarization could be blocked with calcium antagonist PN 200-110. Consistently, the presence of calcium L-channels was shown using whole cell patch-clamp recordings. A comparative study of the responses of myocytes derived from two different segments of the thoracic aorta showed that these cells displayed responses with different maximal amplitudes and the same potencies according to their topological origin in the vessel.

Identification of MEFV-independent modifying genetic factors for familial Mediterranean fever.

Familial Mediterranean fever (FMF) is a recessively inherited disorder predisposing to renal amyloidosis and associated with mutations in MEFV, a gene encoding a protein of unknown function. Differences in clinical expression have been attributed to MEFV-allelic heterogeneity, with the M694V/M694V genotype associated with a high prevalence of renal amyloidosis. However, the variable risk for patients with identical MEFV mutations to develop this severe complication, prevented by lifelong administration of colchicine, strongly suggests a role for other genetic and/or environmental factors. To overcome the well-known difficulties in the identification of modifying genetic factors, we investigated a relatively homogeneous population sample consisting of 137 Armenian patients with FMF from 127 independent families living in Armenia. We selected the SAA1, SAA2, and APOE genes-encoding serum amyloid proteins and apolipoprotein E, respectively-as well as the patients' sex, as candidate modifiers for renal amyloidosis. A stepwise logistic-regression analysis showed that the SAA1alpha/alpha genotype was associated with a sevenfold increased risk for renal amyloidosis, compared with other SAA1 genotypes (odds ratio [OR] 6. 9; 95% confidence interval [CI] 2.5-19.0). This association, which was present whatever the MEFV genotype, was extremely marked in patients homozygous for M694V (11/11). The risk for male patients of developing renal amyloidosis was fourfold higher than that for female patients (OR=4.0; 95% CI=1.5-10.8). This association, particularly marked in patients who were not homozygous for M694V (34.0% vs. 11.6%), was independent of SAA1-allelic variations. Polymorphisms in the SAA2 or APOE gene did not appear to influence susceptibility to renal amyloidosis. Overall, these data, which provide new insights into the pathophysiology of FMF, demonstrate that susceptibility to renal amyloidosis in this Mendelian disorder is influenced by at least two MEFV-independent factors of genetic origin-SAA1 and sex-that act independently of each other.