13 research outputs found
Prevalence and Characteristics of Lung Involvement on High Resolution Computed Tomography in Patients with Ankylosing Spondylitis: A Systematic Review
To determine the prevalence of lung involvement and the spectrum of abnormalities revealed on HRCT in patients with AS, a systematic literature review was conducted in the Medline database up to May 2009 and in the abstracts of rheumatology scientific meetings (2006–2008). A hand search of references was also performed. Among the 264 selected articles, 10 articles (303 patients) allowed a calculation of the prevalence of lung abnormalities on thoracic HRCT in AS. A total of 185 patients (61%) had an abnormal thoracic HRCT: upper lobe fibrosis in 21 (6.9%), emphysema in 55 (18.1%), bronchiectasis in 33 (10.8%), and ground glass attenuation in 34 (11.2%). Non specific interstitial abnormalities were observed in 101 (33%) patients. The most common observed abnormalities were pleural thickening (52%), parenchymal bands (45%) and interlobular septal thickening (30%). Only the prevalence of upper lobe fibrosis increased significantly with disease duration (3 studies). Mild and non-specific interstitial abnormalities on thoracic HRCT are common in patients with AS, even in patients with early disease and without respiratory symptoms
Evaluation des options financières : revue de littérature et explication intuitive des méthodes de calcul
This paper provides a qualitative explanation of the more common financial European options pricing models, namely the Black-Scholes formula, Monte Carlo simulation and the binomial model. The first part is a general introduction to the concept and types of financial options. The second part discusses the variables that determine option prices and gives a conceptual view on the Brownian motion process as a mother-assumption of the aforementioned parametric methods. Finally, the article explains the logic of these three methods, in the purpose to share another way of understanding the financial options models from a qualitative perspective
EVALUATION DES OPTIONS FINANCIERES : REVUE DE LITTERATURE ET EXPLICATION INTUITIVE DES METHODES DE CALCUL - REVUE DE BIBLIOGRAPHIE –
This paper provides a qualitative explanation of the more common financial European options pricing models, namely the Black-Scholes formula, Monte Carlo simulation and the binomial model.The first part is a general introduction to the concept and types of financial options. The second part discusses the variables that determine option prices andgives a conceptual view on the Brownian motion processas a mother-assumption of the aforementioned parametric methods. Finally, the article explains the logic of these three methods, in the purpose to share another way of understanding the financial options models from a qualitative perspective
Evaluation des options financières : revue de littérature et explication intuitive des méthodes de calcul
This paper provides a qualitative explanation of the more common financial European options pricing models, namely the Black-Scholes formula, Monte Carlo simulation and the binomial model. The first part is a general introduction to the concept and types of financial options. The second part discusses the variables that determine option prices and gives a conceptual view on the Brownian motion process as a mother-assumption of the aforementioned parametric methods. Finally, the article explains the logic of these three methods, in the purpose to share another way of understanding the financial options models from a qualitative perspective
Hypovitaminosis D and prevalent asymptomatic vertebral fractures in Moroccan postmenopausal women
BACKGROUND: Hypovitaminosis D is associated to accentuated bone loss. However, association between osteoporotic vertebral fractures (VFs) and vitamin D status has not been clearly established. OBJECTIVE: To determine serum vitamin D status and to assess the association of vitamin D status with bone mineral density (BMD) and asymptomatic VFs prevalence using vertebral fracture assessment (VFA) in a cohort of Moroccan menopausal women. METHODS: from June to September 2010, 178 menopausal women 50 years old and over were enrolled in this cross-sectional study. The mean ± SD (range) age, weight, height and BMI were 58.8 ± 8.2 (50 to 79) years, 73.2 ± 13.8 (35 to 119) Kgs, 1.56 ± 0.06 (1.43 – 1.79) m and 29.8 ± 5.9 (17.5 – 49.8) kg/m(2), respectively. VFA images and scans of the lumbar spine and proximal femur were obtained using a GE Healthcare Lunar Prodigy densitometer. VFs were defined using a combination of Genant semiquantitative approach and morphometry. Serum levels of 25-hydroxyvitamin D (25(OH)D) were measured. RESULTS: Among the 178 women, 45 (25.2%) had densitometric osteoporosis, and on VFA, VFs (grade 2 or 3) were detected in 20.2% while grade 1 were identified in 33.1%. The mean values of serum levels of 25(OH)D were 15.8 ± 11.6 ng/ml (range: 3.0 – 49.1) with 152 patients (85.3%) having levels <30 ng/ml (insufficiency) and 92 (51.6%) <10 ng/ml (deficiency). Stepwise regression analysis showed that presence of VFs was independently related to age, 25(OH)D and densitometric osteoporosis. CONCLUSION: our study shows that advanced age, hypovitaminosis D and osteoporosis are independent risk factors for asymptomatic VFs in Moroccan postmenopausal women
Risk factors of osteoporosis in healthy Moroccan men
<p>Abstract</p> <p>Background</p> <p>Although not as common as in women, osteoporosis remains a significant health care problem in men. Data concerning risk factors of osteoporosis are lacking for the male Moroccan population. The objective of the study was to identify some determinants associated to low bone mineral density in Moroccan men.</p> <p>Methods</p> <p>a sample of 592 healthy men aged 20-79 years was recruited from the area of Rabat, the capital of Morocco. Measurements were taken at the lumbar spine and proximal femurs using DXA (Lunar Prodigy Vision, GE). Biometrical, clinical, and lifestyle determinants were collected. Univariate, multivariate, and logistic regression analyses were performed.</p> <p>Results</p> <p>the mean (SD) age of the patients was 49 (17.2) years old. The prevalence of osteoporosis and osteopenia were 8.7% and 52.8%, respectively. Lumbar spine and hip BMD correlated significantly with age, weight and BMI. When comparing the subjects according to the WHO classification, significant differences were revealed between the three groups of subjects for age, weight and BMI, prevalence of low calcium intake and low physical activity. The multiple regression analysis found that only age, BMI, and high coffee consumption were independently associated to the osteoporotic status.</p> <p>Conclusion</p> <p>ageing and low BMI are the main risk factors associated with osteoporosis in Moroccan men.</p
Impact of Mixed Equine Influenza Vaccination on Correlate of Protection in Horses
To evaluate the humoral immune response to mixed Equine Influenza vaccination, a common practice in the field, an experimental study was carried out on 42 unvaccinated thoroughbred weanling foals divided into six groups of seven. Three groups were vaccinated using a non-mixed protocol (Equilis® Prequenza-Te, Proteqflu-Te® or Calvenza-03®) and three other groups were vaccinated using a mix of the three vaccines mentioned previously. Each weanling underwent a primary EI vaccination schedule composed of two primary immunisations (V1 and V2) four weeks apart followed by a third boost immunisation (V3) six months later. Antibody responses were monitored until one-year post-V3 by single radial haemolysis (SRH). The results showed similar antibody responses for all groups using mixed EI vaccination and the group exclusively vaccinated with Equilis® Prequenza-TE, which were significantly higher than the other two groups vaccinated with Proteqflu-TE® and Calvenza-03®. All weanlings (100%) failed to seroconvert after V1 and 21% (9/42) still had low or no SRH antibody titres two weeks post-V2. All weanlings had seroconverted and exceeded the clinical protection threshold one month after V3. The poor response to vaccination was primarily observed in groups exclusively vaccinated with Proteqflu-Te® and Calvenza-03®. A large window of susceptibility (3–4.5-month duration) usually called immunity gap was observed after V2 and prior to V3 for all groups. The SRH antibody level was maintained above the clinical protection threshold for three months post-V3 for the groups exclusively vaccinated with Proteqflu-Te® and Calvenza-03®, and six months to one year for groups using mixed EI vaccination or exclusively vaccinated with Equilis® Prequenza-Te. This study demonstrates for the first time that the mix of EI vaccines during the primary vaccination schedule has no detrimental impact on the correlate of protection against EIV infection
An Evaluation of Three Different Primary Equine Influenza Vaccination Intervals in Foals
International audienceIn order to evaluate the effect of three different primary vaccination intervals on EI vaccine response, 21 unvaccinated thoroughbred foals were randomly divided into three groups of 7 and vaccinated with three different intervals of primary immunization (i.e., with 1, 2 or 3 months intervals between V1 and V2, respectively). The antibody response was measured for up to 1 year after the third immunization V3 (administered 6 months after V2) by single radial hemolysis (SRH) assay. All weanlings had seroconverted and exceeded the clinical protection threshold 2 weeks after V2 and 1 month after V3 until the end of the study. Significant differences were measured at the peak of immunity after V2 and for the duration of the immunity gap between V2 and V3. The group with one month primary vaccination interval had a lower immunity peak after V2 (158.05 ± 6.63 mm2) and a wider immunity gap between V2 and V3 (18 weeks) when compared with other groups (i.e., 174.72 ± 6.86 mm2 and 16 weeks for a two months interval, 221.45 ± 14.48 mm2 and 12 weeks for a 3-month interval). The advantage observed in the group with 1 month primary vaccination interval, which induces an earlier protective immunity, is counterbalance with a lower peak of immunity and a wider immunity gap after V2, when compared with foals vaccinated with 2- and 3-month intervals