Effect of Low Dose (Diagnostic X-Rays) on Peripheral White Blood Cells Count in Guinea Pigs (<em>Cavia porcellus</em>)

Exposure to ionizing radiation is known to affect some hematological parameters of biological sample. This study was aimed at evaluating the effect of ionizing radiation within the diagnostic range on some hematological parameters in guinea pigs. Thirty six (36) apparently healthy adult guinea pigs of both sexes weighing between 700 and 1200 g were used. The guinea pigs were categorized in to three groups, 12 per group; group A (control), group B, and C were exposed to X-rays within the diagnostic range, using 70 kV and 12.5mAs; using X-ray machine MS-185, serial no. 0904 GE at a source to skin distance (SSD) of 90 cm. Blood samples were collected from all the guinea pigs at intervals of 1, 24, 72, 168 and 336 hours post-irradiation, and subjected to standard hematological analysis. A continuous decline in the mean total white blood cell count and mean lymphocyte, monocyte, neutrophil and eosinophil count after 1 hour in both groups was observed, and more pronounced after 24 hours post-irradiation. However, stability was observed 72 hours post-irradiation in both groups. In conclusion, a depleting effect of low dose ionizing radiation on white blood cell count was found, with appreciable recovery occurring after 72 hours onward

Influence of the sodium fluoride on the development and survival of the loach embryos

Background: The study of fluoride effects at the cellular level is still essential for biophysics, medicine, and ecology as one of the most common environmental pollutants. Its impact on embryonic objects is poorly understood. Objectives: The aim of the work was: 1) to study the effect of sodium fluoride (in the minimum concentration to inhibit growth) on the morphological development of loaсh embryos; 2) evaluation of the degree of survival of embryos in the presence of sodium fluoride in the incubation medium and determination of the coefficient Ks. Materials and methods: Ovulation in loach females (Misgurnus fossilis L.) was stimulated by intramuscular injection of female chorionic gonadotropin (500 units), eggs were obtained by 36 h after stimulation, fertilized in Petri dishes with a suspension of sperm according to Neifach A. A. The stages of development were observed visually used a binocular microscope MBS-9 with a photo camera. The experimental embryos were incubated in Goltfreter's solution with the addition of sodium fluoride to a final minimum concentration to inhibit growth of 500 μmol/l. Results: Sodium fluoride inhibits the development of loach embryos and leads to developmental defects. The noticeable developmental defects caused by sodium fluoride were a reduction in the size of the larvae's head and tail, low body pigmentation, changes in the eye diameter, and embryonic touch reflex. As a result of the accumulation of fluoride in embryonic cells, on the third day of development, embryonic mortality increased to 88,9%. On 12 days under the action of sodium fluoride, the total number of larvae was about 2%. Conclusions: The ability of NaF to act as a direct teratogen was tested on the cold-blooded embryo model, the same effect was found by other investigators on the FETAX model. The possibility that sodium fluoride may cause toxic and/or neuromuscular developmental defects in human embryos also should be considered. Avoiding excessive getting of fluoride in the body by limiting the consumption of foods or beverages high in fluoride, the use of fluoride in dental care products, etc. requires detailed assessment

Semi-conducteurs Isotropes et Stables pour Cellules solaires Organiques

Date du colloque : 03/2011</p

MRI features of the normal prostatic peripheral zone: the relationship between age and signal heterogeneity on T2WI, DWI, and DCE sequences

Funder: University of CambridgeAbstract: Objectives: To assess the multiparametric MRI (mpMRI) appearances of normal peripheral zone (PZ) across age groups in a biopsy-naïve population, where prostate cancer (PCa) was subsequently excluded, and propose a scoring system for background PZ changes. Methods: This retrospective study included 175 consecutive biopsy-naïve patients (40–74 years) referred with a suspicion of PCa, but with subsequent negative investigations. Patients were grouped by age into categories ≤ 54, 55–59, 60–64, and ≥ 65 years. MpMRI sequences (T2-weighted imaging [T2WI], diffusion-weighted imaging [DWI]/apparent diffusion coefficient [ADC], and dynamic contrast-enhanced imaging [DCE]) were independently evaluated by two uro-radiologists on a proposed 4-point grading scale for background change on each sequence, wherein score 1 mirrored PIRADS-1 change and score 4 represented diffuse background change. Peripheral zone T2WI signal intensity and ADC values were also analyzed for trends relating to age. Results: There was a negative correlation between age and assigned background PZ scores for each mpMRI sequence: T2WI: r = − 0.52, DWI: r = − 0.49, DCE: r = − 0.45, p < 0.001. Patients aged ≤ 54 years had mean scores of 3.0 (T2WI), 2.7 (DWI), and 3.1 (DCE), whilst patients ≥ 65 years had significantly lower mean scores of 1.7, 1.4, and 1.9, respectively. There was moderate inter-reader agreement for all scores (range κ = 0.43–0.58). Statistically significant positive correlations were found for age versus normalized T2WI signal intensity (r = 0.2, p = 0.009) and age versus ADC values (r = 0.33, p = 0.001). Conclusion: The normal PZ in younger patients (≤ 54 years) demonstrates significantly lower T2WI signal intensity, lower ADC values, and diffuse enhancement on DCE, which may hinder diagnostic interpretation in these patients. The proposed standardized PZ background scoring system may help convey the potential for diagnostic uncertainty to clinicians. Key Points: • Significant, positive correlations were found between increasing age and higher normalized T2-weighted signal intensity and mean ADC values of the prostatic peripheral zone. • Younger men exhibit lower T2-weighted imaging signal intensity, lower ADC values, and diffuse enhancement on dynamic contrast-enhanced imaging, which may hinder MRI interpretation. • A scoring system is proposed which aims towards a standardized assessment of the normal background PZ. This may help convey the potential for diagnostic uncertainty to clinicians

Modelling Hierarchy and Specialization of a System of Cities from an Evolutionary Perspective on Firms' Interactions

Despite their great diversity, most systems of cities show remarkably similar patterns when comparing the size distribution and the economic specialization of their constitutive cities. The universality of these patterns sparked the interest of geographers, economists and physicists. However, until now, no economic model has relied on a micro-based and evolutionary approach to reproduce these regularities. In this chapter, we intend to fill this gap by proposing a model where the micro dynamics of localized firms generate the two macro regularities of size distribution and economic specialization. The model is based on boundedly rational firms’ competition and path dependent innovation. We discuss the possible emergence of macro properties from these micro behaviors of firms

Cellules solaires organiques à héterojonction volumique à base de donneurs moléculaires dérivés du BODIPY.

Date du colloque&nbsp;: 10/2010</p

Urgent need to clarify the definition of chronic critical limb ischemia - a position paper from the European Society for Vascular Medicine

Chronic critical lower limb ischemia (CLI) has been defined as ischemia that endangers the leg. An attempt was made to give a precise definition of CLI, based on clinical and hemodynamic data (Second European Consensus). CLI may be easily defined from a clinical point of view as rest pain of the distal foot or gangrene or ulceration. It is probably useful to add leg ulcers of other origin which do not heal because of severe ischemia, and to consider the impact of frailty on adverse outcome. From a hemodynamic viewpoint there is no consensus and most of the existing classifications are not based upon evidence. We should thus propose a definition and then validate it in a prospective cohort in order to define the patients at major risk of amputation, and also to define the categories of patients whose prognosis is improved by revascularisation. From today\u27s available data, it seems clear that the patients with a systolic toe pressure (STP) below 30 mmHg must be revascularised whenever possible. However other patients with clinically suspected CLI and STP above 30 mmHg must be evaluated and treated in specialised vascular units and revascularisation has to be discussed on a case by case basis, taking into account other data such as the WiFi classification for ulcers.In conclusion, many useful but at times contradictory definitions of CLI have been suggested. Only a few have taken into account evidence, and none have been validated prospectively. This paper aims to address this and to give notice that a CLI registry within Europe will be set up to prospectively validate, or not, the previous and suggested definitions of CLI

Endocannabinoid Regulation of Acute and Protracted Nicotine Withdrawal: Effect of FAAH Inhibition

Evidence shows that the endocannabinoid system modulates the addictive properties of nicotine. In the present study, we hypothesized that spontaneous withdrawal resulting from removal of chronically implanted transdermal nicotine patches is regulated by the endocannabinoid system. A 7-day nicotine dependence procedure (5.2 mg/rat/day) elicited occurrence of reliable nicotine abstinence symptoms in Wistar rats. Somatic and affective withdrawal signs were observed at 16 and 34 hours following removal of nicotine patches, respectively. Further behavioral manifestations including decrease in locomotor activity and increased weight gain also occurred during withdrawal. Expression of spontaneous nicotine withdrawal was accompanied by fluctuation in levels of the endocannabinoid anandamide (AEA) in several brain structures including the amygdala, the hippocampus, the hypothalamus and the prefrontal cortex. Conversely, levels of 2-arachidonoyl-sn-glycerol were not significantly altered. Pharmacological inhibition of fatty acid amide hydrolase (FAAH), the enzyme responsible for the intracellular degradation of AEA, by URB597 (0.1 and 0.3 mg/kg, i.p.), reduced withdrawal-induced anxiety as assessed by the elevated plus maze test and the shock-probe defensive burying paradigm, but did not prevent the occurrence of somatic signs. Together, the results indicate that pharmacological strategies aimed at enhancing endocannabinoid signaling may offer therapeutic advantages to treat the negative affective state produced by nicotine withdrawal, which is critical for the maintenance of tobacco use