23 research outputs found
Trans-species transmission of Brucellae among ruminants hampering brucellosis control efforts in Egypt
Aims: This study aimed to identify the genotypic fingerprinting of Brucella melitensis biovar 3 isolates from ruminants in Kafr El-Sheikh, Egypt, to compare with other peers globally and to highlight the epidemiology and potential causes of brucellosis control failure.Kafr El-Sheikh University, Grant/Award Number: KFSU-3-13-04Depto. de Sanidad AnimalCentro de Vigilancia Sanitaria Veterinaria (VISAVET)TRUEpu
Optimization of self-nanoemulsifying formulations for weakly basic lipophilic drugs: role of acidification and experimental design
ABSTRACT Formulators face great challenges in adopting systematic approaches for designing self-nanoemulsifying formulations (SNEFs) for different drug categories. In this study, we aimed to build-up an advanced SNEF development framework for weakly basic lipophilic drugs, such as cinnarizine (CN). First, the influence of formulation acidification on CN solubility was investigated. Second, formulation self-emulsification in media with different pH was assessed. Experimentally designed phase diagrams were also utilized for advanced optimization of CN-SNEF. Finally, the optimized formulation was examined using cross polarizing light microscopy for the presence of liquid crystals. CN solubility was significantly enhanced upon external and internal acidification. Among the various fatty acids, oleic acid-based formulations showed superior self-emulsification in all the tested media. Surprisingly, formulation turbidity and droplet size significantly decreased upon equilibration with CN. The design was validated using oleic acid/Imwitor308/Cremophor El (25/25/50), which showed excellent self-nanoemulsification, 43-nm droplet size (for CN-equilibrated formulations), and 88 mg/g CN solubility. In contrast to CN-free formulations, CN-loaded SNEF presented lamellar liquid crystals upon 50% aqueous dilution. These findings confirmed that CN-SNEF efficiency was greatly enhanced upon drug incorporation. The adopted strategy offers fast and accurate development of SNEFs and could be extrapolated for other weakly basic lipophilic drugs
Twelve-month observational study of children with cancer in 41 countries during the COVID-19 pandemic
Introduction Childhood cancer is a leading cause of death. It is unclear whether the COVID-19 pandemic has impacted childhood cancer mortality. In this study, we aimed to establish all-cause mortality rates for childhood cancers during the COVID-19 pandemic and determine the factors associated with mortality. Methods Prospective cohort study in 109 institutions in 41 countries. Inclusion criteria: children <18 years who were newly diagnosed with or undergoing active treatment for acute lymphoblastic leukaemia, non-Hodgkin's lymphoma, Hodgkin lymphoma, retinoblastoma, Wilms tumour, glioma, osteosarcoma, Ewing sarcoma, rhabdomyosarcoma, medulloblastoma and neuroblastoma. Of 2327 cases, 2118 patients were included in the study. The primary outcome measure was all-cause mortality at 30 days, 90 days and 12 months. Results All-cause mortality was 3.4% (n=71/2084) at 30-day follow-up, 5.7% (n=113/1969) at 90-day follow-up and 13.0% (n=206/1581) at 12-month follow-up. The median time from diagnosis to multidisciplinary team (MDT) plan was longest in low-income countries (7 days, IQR 3-11). Multivariable analysis revealed several factors associated with 12-month mortality, including low-income (OR 6.99 (95% CI 2.49 to 19.68); p<0.001), lower middle income (OR 3.32 (95% CI 1.96 to 5.61); p<0.001) and upper middle income (OR 3.49 (95% CI 2.02 to 6.03); p<0.001) country status and chemotherapy (OR 0.55 (95% CI 0.36 to 0.86); p=0.008) and immunotherapy (OR 0.27 (95% CI 0.08 to 0.91); p=0.035) within 30 days from MDT plan. Multivariable analysis revealed laboratory-confirmed SARS-CoV-2 infection (OR 5.33 (95% CI 1.19 to 23.84); p=0.029) was associated with 30-day mortality. Conclusions Children with cancer are more likely to die within 30 days if infected with SARS-CoV-2. However, timely treatment reduced odds of death. This report provides crucial information to balance the benefits of providing anticancer therapy against the risks of SARS-CoV-2 infection in children with cancer
Mortality of emergency abdominal surgery in high-, middle- and low-income countries
Background: Surgical mortality data are collected routinely in high-income countries, yet virtually no low- or middle-income countries have outcome surveillance in place. The aim was prospectively to collect worldwide mortality data following emergency abdominal surgery, comparing findings across countries with a low, middle or high Human Development Index (HDI).
Methods: This was a prospective, multicentre, cohort study. Self-selected hospitals performing emergency surgery submitted prespecified data for consecutive patients from at least one 2-week interval during July to December 2014. Postoperative mortality was analysed by hierarchical multivariable logistic regression.
Results: Data were obtained for 10 745 patients from 357 centres in 58 countries; 6538 were from high-, 2889 from middle- and 1318 from low-HDI settings. The overall mortality rate was 1â
6 per cent at 24 h (high 1â
1 per cent, middle 1â
9 per cent, low 3â
4 per cent; P < 0â
001), increasing to 5â
4 per cent by 30 days (high 4â
5 per cent, middle 6â
0 per cent, low 8â
6 per cent; P < 0â
001). Of the 578 patients who died, 404 (69â
9 per cent) did so between 24 h and 30 days following surgery (high 74â
2 per cent, middle 68â
8 per cent, low 60â
5 per cent). After adjustment, 30-day mortality remained higher in middle-income (odds ratio (OR) 2â
78, 95 per cent c.i. 1â
84 to 4â
20) and low-income (OR 2â
97, 1â
84 to 4â
81) countries. Surgical safety checklist use was less frequent in low- and middle-income countries, but when used was associated with reduced mortality at 30 days.
Conclusion: Mortality is three times higher in low- compared with high-HDI countries even when adjusted for prognostic factors. Patient safety factors may have an important role. Registration number: NCT02179112 (http://www.clinicaltrials.gov)
Inference for the Exponential Distribution under Generalized Progressively Hybrid Censored Data from Partially Accelerated Life Tests with a Time Transformation Function
In this article, the tampered failure rate model is used in partially accelerated life testing. A non-decreasing time function, often called a ââtime transformation function", is proposed to tamper the failure rate under design conditions. Different types of the proposed function, which have sufficient conditions in order to be accelerating functions, are investigated. A baseline failure rate of the exponential distribution is considered. Some point estimation methods, as well as approximate confidence intervals, for the parameters involved are discussed based on generalized progressively hybrid censored data. The determination of the optimal stress change time is discussed under two different criteria of optimality. A real dataset is employed to explain the theoretical outcomes discussed in this article. Finally, a Monte Carlo simulation study is carried out to examine the performance of the estimation methods and the optimality criteria
Statistical Prediction Based on Ordered Ranked Set Sampling Using Type-II Censored Data from the Rayleigh Distribution under Progressive-Stress Accelerated Life Tests
The objective of ranked set sampling is to gather observations from a population that is more likely to cover the populationâs full range of values. In this paper, the ordered ranked set sample is obtained using the idea of order statistics from independent and nonidentically distributed random variables under progressive-stress accelerated life tests. The lifetime of the item tested under normal conditions is suggested to be subject to the Rayleigh distribution with a scale parameter satisfying the inverse power law such that the applied stress is a nonlinear increasing function of time. Considering the type-II censoring scheme, one-sample prediction for censored lifetimes is discussed. Numerous point predictors including the Bayes point predictor, conditional median predictor, and best unbiased predictor for future order statistics are discussed. Additionally, conditional prediction intervals for future order statistics are also studied. The theoretical findings reported in this work are shown by illustrative examples based on simulated data as well as real data sets. The effectiveness of the prediction methods is then evaluated by a Monte Carlo simulation study
Accuracy and safety of CO2 digital subtraction angiography during endovascular treatment of symptomatic peripheral artery occlusive disease. A prospective study on Egyptian patients
Purpose: To study the efficacy, safety and clinical outcome of carbon dioxide DSA during angioplasty procedures for patients with predominant femoropopliteal segment occlusive lesions, aiming to reduce possible allergic reactions and potential nephrotoxicity. Materials and methods: The study included eighteen Egyptian patients in a prospective manner, with evidence of predominant femoropopliteal arterial occlusive disease by Duplex study. All the selected patients had borderline renal functions with serum creatinine levels between 1.5âŻmg/dL and 2âŻmg/dL. Every patient was scheduled for a percutaneous endovascular therapy during which CO2 DSA and small volume injections of ICM DSA of the diseased segment and distal arterial tree were done. We analyzed our results emphasizing the technical success, CO2 DSA related complications, allergic reactions and intolerance. We also correlated the amount of contrast injected with the serum creatinine levels as well as the degree of opacification of the diseased segment. Results: We were able to achieve technical success in 88% of our cases except in two patients who had TASC D lesions. The average fluoroscopy time in our study was about 100âŻmin. There were no CO2 related complications or allergic reactions. Five patients were intolerant to CO2 injection related pains and repeated injections were performed with smaller volumes. The injected mean volume of CO2 was 76.1âŻmL while the mean volume of ICM used per patient was 24âŻmL. Most patients showed non-significant rise of serum creatinine levels at both samples. Moreover, the results of the âGoodâ score & the âFairâ score for the CO2 DSA image quality plotted by the interobserver agreement was about 40% & 33% respectively from the total number of patients included in the study. Conclusion: CO2 DSA is a non-nephrotoxic alternative to traditional ICM DSA that could be safely used and well tolerated during endovascular management of lower extremity symptomatic arterial disease. When selectively delivered to the femoropopliteal segment, CO2 provides superior quality images that would cancel or markedly reduce the ICM volume required for prompt visualization and decision making during the revascularization procedure. Keywords: Carbon dioxide, Digital subtraction angiography, Iodinated contrast material, Nephrotoxicity, Peripheral vascular occlusive diseas
Reliability analysis of the triple modular redundancy system under step-partially accelerated life tests using Lomax distribution
Abstract Triple modular redundancy (TMR) is a robust technique utilized in safety-critical applications to enhance fault-tolerance and reliability. This article focuses on estimating the distribution parameters of a TMR system under step-stress partially accelerated life tests, where each component included in the system follows a Lomax distribution. The study aims to analyze the systemâs reliability and mean residual lifetime based on the estimated parameters. Various estimation techniques, including maximum likelihood, percentile, least squares, and maximum product of spacings, are explored. Additionally, the optimal stress change time is determined using two criteria. An illustrative example supported by two actual data sets is presented to showcase the methodologyâs application. By conducting Monte Carlo simulations, the assessment of the estimation methodsâ effectiveness reveals that the maximum likelihood method outperforms the other three methods in terms of both accuracy and performance, as indicated by the numerical outcomes. This research contributes to the understanding and practical implementation of TMR systems in safety-critical industries, potentially saving lives and preventing catastrophic events