14 research outputs found
Chyloperitoneum.
Chiloperitoneumul reprezintă o afecţiune rară cu extravazarea de chil în cavitatea peritoneală. După mecanismul de producere poate fi atât traumatic, cât şi nontraumatic. Complicaţiile principale includ malnutriţia şi imunosupresia. Autorii discută în privinţa etiologiei, simptomatologiei, diagnosticului şi metodelor de tratament în contextul revistei de literatură
Controlling Wolbachia transmission and invasion dynamics among aedes aegypti population via impulsive control strategy
This work is devoted to analyzing an impulsive control synthesis to maintain the self-sustainability of Wolbachia among Aedes Aegypti mosquitoes. The present paper provides a fractional order Wolbachia invasive model. Through fixed point theory, this work derives the existence and uniqueness results for the proposed model. Also, we performed a global Mittag-Leffler stability analysis via Linear Matrix Inequality theory and Lyapunov theory. As a result of this controller synthesis, the sustainability of Wolbachia is preserved and non-Wolbachia mosquitoes are eradicated. Finally, a numerical simulation is established for the published data to analyze the nature of the proposed Wolbachia invasive model.Prince Sultan Universit
Multibody Systems with Flexible Elements
Multibody systems with flexible elements represent mechanical systems composed of many elastic (and rigid) interconnected bodies meeting a functional, technical, or biological assembly. The displacement of each or some of the elements of the system is generally large and cannot be neglected in mechanical modeling. The study of these multibody systems covers many industrial fields, but also has applications in medicine, sports, and art. The systematic treatment of the dynamic behavior of interconnected bodies has led to an important number of formalisms for multibody systems within mechanics. At present, this formalism is used in large engineering fields, especially robotics and vehicle dynamics. The formalism of multibody systems offers a means of algorithmic analysis, assisted by computers, and a means of simulating and optimizing an arbitrary movement of a possibly high number of elastic bodies in the connection. The domain where researchers apply these methods are robotics, simulations of the dynamics of vehicles, biomechanics, aerospace engineering (helicopters and the behavior of cars in a gravitational field), internal combustion engines, gearboxes, transmissions, mechanisms, the cellulose industry, simulation of particle behavior (granulated particles and molecules), dynamic simulation, military applications, computer games, medicine, and rehabilitation
Maternal-child health - interdisciplinary aspects within the perspective of global health
Maternal-Child Health is one of the greatest challenges the world has to cope with today. Every year, thousands of women, newborns and children die unnecessarily, particularly in resource-poor settings. There is a great disparity caused by food insecurity and hunger, environmental health risks, sanitation challenges, cultural barriers and non-accessibility to diagnosis and treatment. "Maternal-Child Health: Interdisciplinary Aspects within the Perspective of Global Health" addresses these issues. The contributions of this book are based on the ONE HEALTH concept by focusing on infectious and non-communicable diseases and to present interdisciplinary views from more than 60 authors who come from 14 countries. The aim is to shape our understanding on Maternal-Child Health Solutions by looking at > agricultural and environmental > economic, social and theological > biomedical and nutritional > clinical human and veterinary as well as > epidemiology and > public health expertise. The Göttingen International Health Network is corresponding to a variety of different geographic regions and programs to improve global health perspective and health of the most vulnerable: mothers and their children
Characterization of intracellular interactions between dengue virus and host proteins
Dengue virus is the causative agent of dengue fever, dengue hemorrhagic fever and dengue shock syndrome. About two-fifths of world population live in areas where dengue is prevalent, leading to high levels of morbidity and mortality in many areas. Currently there are no vaccines or effective treatments. The virus is transmitted from one person to another by the yellow fever mosquito, Aedes aegypti. The genome of dengue virus encodes only ten proteins implying that the virus needs to interact with and utilize several host proteins for replication. In this project, I used high-throughput yeast two-hybrid screening to identify mosquito and human proteins that physically interact with dengue proteins. I detected 46 dengue-human and 102 dengue-mosquito protein interactions, including some that had been discovered previously and many novel interactions. I further confirmed 38 out of 136 testable interactions using co-affinity purification assays from cultured cells. I tested each host protein against the proteins from all four serotypes of dengue virus and found that 57 out of 102 (56.9%) dengue-mosquito PPI and 34 out of 46 (73.9%) dengue-human PPI interacted with corresponding dengue proteins from all four serotypes.
To further analyze biological significance of these protein interactions, I selected to study capsid-NAP1 interaction. I employed the domain mapping of capsid using yeast two-hybrid and co-affinity purification. I also over-expressed or silenced NAP1L1 in HepG2 cells stably expressing capsid. I found that NAP1L1 might bind the bipartite sequence of capsid blocking importin binding and sequestering capsid in the cytoplasm.
I also showed that the mosquito cells, AAG2, were capable of uptaking double stranded RNA without a transfection vehicle. Thus, a large-scale RNA interference study in AAG2 as previously published is feasible.
Finally, I showed that using two 2A sequences to generate three separate peptides form a single mRNA was possible in the insect cells. This construct may be applied to design a non-infectious dengue replicon, which may be a safer substitute of the live dengue virus.
The dengue-host interaction maps and the new tools that I generated should be useful for understanding how dengue interacts with its hosts and may provide candidates for drug targets and vector control strategies
Host cellular regulatory networks in dengue virus-human interactions
Dengue fever is one of the most important mosquito-borne diseases worldwide and is caused by infection with dengue virus (DENV). The disease is endemic in tropical and sub-tropical regions and has increased remarkably in the last few decades. At present, there is no antiviral or approved vaccine against the virus. Treatment of dengue patients is usually supportive, through oral or intravenous rehydration, or by blood transfusion for more severe dengue cases. Infection of DENV in humans and mosquitoes involves a complex interplay between the virus and host factors. This results in regulation of numerous intracellular processes, such as signal transduction and gene transcription which leads to progression of disease. To understand the mechanisms underlying the disease, the study of virus and host factors is therefore essential and could lead to the identification of human proteins modulating an essential step in the virus life cycle. Knowledge of these human proteins could lead to the discovery of potential new drug targets and disease control strategies in the future.
Recent advances of high throughput screening technologies have provided researchers with molecular tools to carry out investigations on a large scale. Several studies have focused on determination of the host factors during DENV infection in human and mosquito cells. For instance, a genome-wide RNA interference (RNAi) screen has identified host factors that potentially play an important role in both DENV and West Nile virus replication (Krishnan et al. 2008). In the present study, a high-throughput yeast two-hybrid screen has been utilised in order to identify human factors interacting with DENV non-structural proteins. From the screen, 94 potential human interactors were identified. These include proteins involved in immune signalling regulation, potassium voltage-gated channels, transcriptional regulators, protein transporters and endoplasmic reticulum-associated proteins. Validation of fifteen of these human interactions revealed twelve of them strongly interacted with DENV proteins. Two proteins of particular interest were selected for further investigations of functional biological systems at the molecular level.
These proteins, including a nuclear-associated protein BANP and a voltage-gated potassium channel Kv1.3, both have been identified through interaction with the DENV NS2A. BANP is known to be involved in NF-kB immune signalling pathway, whereas, Kv1.3 is known to play an important role in regulating passive flow of potassium ions upon changes in the cell transmembrane potential.
This study also initiated a construction of an Aedes aegypti cDNA library for use with DENV proteins in Y2H screen. However, several issues were encountered during the study which made the library unsuitable for protein interaction analysis. In parallel, innate immune signalling was also optimised for downstream analysis. Overall, the work presented in this thesis, in particular the Y2H screen provides a number of human factors potentially targeted by DENV during infection. Nonetheless, more work is required to be done in order to validate these proteins and determine their functional properties, as well as testing them with infectious DENV to establish a biological significance. In the long term, data from this study will be useful for investigating potential human factors for development of antiviral strategies against dengue
Role of ureaplasma spp in neonatal lung disease, activation of the complement system and molecular mechanisms of antibiotic resistance
Ureaplasmas are some of the smallest and simplest free-living organisms known. Little is understood regarding the effects of the complement system upon clearance of these pathogens, but when the immune system fails to control Ureaplasma colonization disease, such as chronic lung disease of prematurity (CLD), can occur. Treatment of such Ureaplasma infections, especially in neonates, is limited by pathogen and host factors. Treatment can be further compromised by antibiotic resistance. Firstly this thesis examines an in vitro system for determining the bactericidal capacity of a selection of human sera against four representative serovars of Ureaplasma parvum. Results showed that the classical activation pathway was essential for the killing of all U. parvum serovars, with little effect being attributed to the alternative or lectin pathways. Additionally serovar 3 was shown to be the most serum sensitive isolate. Secondly the association between presence of Ureaplasma and 16S rRNA with development of CLD was examined in a prospective cohort of 192 neonates. Data suggested that presence of Ureaplasma as well as 16S rRNA was significantly associated with development of CLD as well as increased levels of inflammatory mediators IL-6 and IL-8. Finally a retrospective cohort of 61 Ureaplasma isolates was examined for resistance to various antibiotics. High level macrolide resistance in isolate UHWO10 resulted from a two amino acid deletion within the L4 ribosomal protein (R66Q67). Tetracycline resistance in isolate HPA23 resulted from the presence of the tetM gene while a ciprofloxacin resistance in isolate HPA18 resulted from a D82N substitution within the ParC protein. No differences were found in the GyrA, GyrB or ParE proteins. Comparison of type II topoisomerase genes from all Ureaplasma serovars revealed that mutations previously associated with resistance where wrongly identified and were a result of species or serovar specific polymorphisms.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Role of ureaplasma spp in neonatal lung disease, activation of the complement system and molecular mechanisms of antibiotic resistance
Ureaplasmas are some of the smallest and simplest free-living organisms known. Little is understood regarding the effects of the complement system upon clearance of these pathogens, but when the immune system fails to control Ureaplasma colonization disease, such as chronic lung disease of prematurity (CLD), can occur. Treatment of such Ureaplasma infections, especially in neonates, is limited by pathogen and host factors. Treatment can be further compromised by antibiotic resistance. Firstly this thesis examines an in vitro system for determining the bactericidal capacity of a selection of human sera against four representative serovars of Ureaplasma parvum. Results showed that the classical activation pathway was essential for the killing of all U. parvum serovars, with little effect being attributed to the alternative or lectin pathways. Additionally serovar 3 was shown to be the most serum sensitive isolate. Secondly the association between presence of Ureaplasma and 16S rRNA with development of CLD was examined in a prospective cohort of 192 neonates. Data suggested that presence of Ureaplasma as well as 16S rRNA was significantly associated with development of CLD as well as increased levels of inflammatory mediators IL-6 and IL-8. Finally a retrospective cohort of 61 Ureaplasma isolates was examined for resistance to various antibiotics. High level macrolide resistance in isolate UHWO10 resulted from a two amino acid deletion within the L4 ribosomal protein (R66Q67). Tetracycline resistance in isolate HPA23 resulted from the presence of the tetM gene while a ciprofloxacin resistance in isolate HPA18 resulted from a D82N substitution within the ParC protein. No differences were found in the GyrA, GyrB or ParE proteins. Comparison of type II topoisomerase genes from all Ureaplasma serovars revealed that mutations previously associated with resistance where wrongly identified and were a result of species or serovar specific polymorphisms
Neonatal chylous ascites--report of three cases and review of the literature.
Three cases of neonatal chylous ascites (CCA) were managed in the neonatal unit, University Hospital, Kuala Lumpur, over the past 9 years. Fetal ascites and polyhydramnios were the sole abnormalities detected in all three babies by antenatal ultrasonography. They were born at 36 weeks' gestation and their birth weights ranged from 3.0 kg to 3.8 kg. All three infants had abdominal distension at birth. Milky ascitic fluid was obtained after starting enteral feedings. Analysis of the ascitic fluid revealed a raised white blood cell count (predominantly lymphocytic) and triglycerides (1.4 - 3.8 mmol/l), cholesterol (1.6 - 2.8 mmol/l), and protein levels (25 - 41 g/l). Conservative management with skimmed milk and medium-chain triglycerides in one infant and Pregestimil in another was instituted. these two infants with CCA were clinically normal when reviewed at 19 months and 3.5 years of age. The third infant had a gut malrotation and associated pyloric septum; he died from complications of a laparotomy. The literature on this rare condition is reviewed