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Postprandial hepatic protein expression in trout Oncorhynchus mykiss a proteomics examination
No full textAbstractFollowing a meal, a series of physiological changes occurs in animals as they digest, absorb and assimilate ingested nutrients, the kinetics of these responses depends on metabolic rate and nutrient quality. Here we investigated the hepatic proteome in the ectothermic teleost, the rainbow trout, following a single meal to define the postprandial expression of hepatic proteins. The fish were fed a high marine fishmeal/fish oil single meal following a period of 24h without feeding. Liver protein profiles were examined by 2D gel electrophoresis just before feeding (time 0h) and at 6 and 12h after feeding. Of a total of 588 protein spots analysed in a temporal fashion, 49 differed significantly in abundance between the three time groups (ANOVA, p<0.05), before and after feeding, 15 were increased and 34 were decreased in abundance after feeding. Amino acid metabolism-regulated proteins such as phenylalanine-4-hydroxylase and proliferating cell antigen were increased in abundance 12 and 6h following the meal, suggesting by this time that the fish were increasing their protein turnover to utilize efficiently their dietary protein consumption. Overall, these results highlight some specificity of the trout metabolism and identify postprandial response of metabolism-related proteins 6–12h after feeding a single meal
3D analytical mathematical models of random star-shape particles via a combination of X-ray computed microtomography and spherical harmonic analysis
No full textAbstractTo compute any physical quantity for a random particle, one needs to know the mathematical shape of the particle. For regular particles like spheres and ellipsoids, the mathematics are straightforward. For random particles, with realistic shapes, mathematically characterizing the shape had not been generally done. But since about the year 2002, a method has been developed that combines X-ray computed tomography and spherical harmonic analysis to give analytical, differentiable mathematical functions for the three-dimensional shape of star-shape particles, which are a wide class of particles covering most industrial particles of interest, ranging from micrometer scale to millimeter scale particles. This review article describes how this is done, in some detail, and then gives examples of applications of this method, including a contact function that is suitable for these random shape particles. The purpose of this article is to make these ideas widely available for the general powder researcher who knows that particle shape is important to his/her applications, and especially for those researchers who are just starting out in their particle science and technology careers
Specific material effects of wear-particle-induced inflammation and osteolysis at the bone–implant interface: A rat model
No full textSummaryIntroductionWear particles produced from prosthetic joints may play critical roles in periprosthetic inflammatory reactions and osteolysis. The objective of this study was to quantify and compare the response to wear debris from different biomaterials at the bone–implant interface in a rat knee model.MethodsSixty rats were divided into titanium alloy (Ti–6Al–4V), cobalt chromium (Co–Cr), ceramic (Al2O3), ultrahigh molecular weight polyethylene (UHMWPE), and control (phosphate buffered saline) groups with 12 animals per group. A nonweight-bearing titanium rod was implanted into the right distal femur of each rat followed by intra-articular injections of the biomaterial particles to the surgical knees for up to 16 weeks. Micro-computed tomography scanning was performed monthly and at the time of sacrifice to determine bone densities around the bone–implant interface. Histological evaluations were executed to quantify local inflammatory reactions and osteoclastogenesis.ResultsCo–Cr particles resulted in the most severe reductions in bone density. UHMWPE and ceramic particles resulted in a rapid reduction in bone density followed by a recovery. Inflammatory pseudo-membranes were ubiquitously present close to the femoral condyle and pin insertion site. Ceramic particles significantly promoted periprosthetic tissue formation compared with the other groups (p < 0.05). Cathepsin K positive cells were dominantly present at the peri-implant site following challenges of metallic alloy and ceramic particles.ConclusionDifferent biomaterials in particulate form exert different forms of adverse effects in terms of the amount of osteolysis and inflammatory reactions on bone tissue at the bone–implant interface. It provides information for engineering more appropriate materials for arthroplasty components
Going native: Complete removal of protein purification affinity tags by simple modification of existing tags and proteases
No full textAbstractProtein purification typically involves expressing a recombinant gene comprising a target protein fused to a suitable affinity tag. After purification, it is often desirable to remove the affinity tag to prevent interference with downstream functions of the target protein. This is mainly accomplished by placing a protease site between the tag and the target protein. Typically, a small oligopeptide ‘stub’ C-terminal to the cleavage site remains attached to the target protein due to the requirements of sequence-specific proteases. Furthermore, steric hindrance can also limit protease efficiency. Here, we show that respectively fusing the interacting ePDZ-b/ARVCF protein-peptide pair to the target protein and a protease enables efficient processing of a minimised sequence comprising only residues N-terminal to the cleavage site. Interaction of the protein-peptide pair enforces proximity of the protease and its minimised cleavage sequence, enhancing both catalysis of a sub-optimal site and overcoming steric hindrance. This facilitates the high yield purification of fully native target proteins without recourse to specialised purification columns
Interactions of infectious F-specific RNA bacteriophages with suspended matter and sediment: Towards an understanding of FRNAPH distribution in a river water system
No full textAbstractThe association of viruses with settling particles is certainly a major process controlling the spread of viral pollution in surface water and sediment. To better understand the viral distribution in a river system, the behavior of F-specific RNA bacteriophages (FRNAPHs) was investigated in relationship with the suspended solids and sediment. The partitioning of phage particles (free or associated with solids) in surface water and the attachment capabilities of eight distinct strains of phages to sediment were studied in lab experiments. In situ observations were also performed with the genotyping of 166 individual plaques of FRNAPHs isolated from surface water and sediment. The results reported here demonstrate a variation of the status of infectious phages as a function of the hydro-climatological conditions. Phage-solid association seems to mainly occur during the peak of rainfall-runoff events but also to a certain extent during the recession phase compared to low flow conditions. The transfer of phages from the water column to sediment may occur at this time. Furthermore, the ability of FRNAPHs to interact with sediment was established for six strains out of eight, belonging to genogroups II, III and IV. A similar dynamic was observed for strains within a same genogroup despite different intensity of attachment and inactivation rates for strains of genogroups III and IV. The latter results match the in situ observations in the water and sediment compartments of the studied area. Infectious FRNAPH genogroup II was more abundant in sediment than in surface water. Its capability to sorb to sediment and its higher persistence in the environment compared to genogroups III and IV were the two main explanations. Together, lab and in situ experiments produce an overall vision of the mechanisms governing FRNAPH distribution among the water column and riverbed sediment
Kinetic spectrophotometric method for the determination of some fourth generation fluoroquinolones in bulk and in pharmaceutical formulations
No full textAbstractA kinetic spectrophotometric method for accurate and sensitive determination of gemifloxacin (GMFX) and gatifloxacin (GTFX) has been described. The method is based on the reaction of the studied drugs with potassium permanganate in the presence of sodium hydroxide to form a water-soluble green product which shows maximum absorbance at 604nm. The determination of GMFX and GTFX drugs by rate constant, fixed-concentration, and fixed time methods was feasible with the calibration equations obtained but the fixed time method had been found to be more applicable. The concentration of the selected drugs is calculated using the calibration equation for the fixed time method. The absorbance–concentration plot is linear over the range of 4–36μgmL−1 and 4–40μgmL−1 with correlation coefficient of 0.9998 and 0.9991, for GMFX and GTFX, respectively. The molar absorptivity, Sandell sensitivity, detection and quantification limits were also calculated. The different experimental parameters affecting the development and stability of the color were carefully studied and optimized. The intra- and inter-day RSD values indicated the ruggedness of the method. The proposed method has been successfully applied to pharmaceutical formulations of each drug. Statistical comparison of the results with a well established reported method showed excellent agreement and proved that there is no significant difference in the accuracy and precision
A quantitative proteomic screen of the Campylobacter jejuni flagellar-dependent secretome
No full textAbstractCampylobacter jejuni is the leading cause of bacterial gastroenteritis in the world. A number of factors are believed to contribute to the ability of C. jejuni to cause disease within the human host including the secretion of non-flagellar proteins via the flagellar type III secretion system (FT3SS). Here for the first time we have utilised quantitative proteomics using stable isotope labelling by amino acids in cell culture (SILAC), and label-free liquid chromatography-mass spectrometry (LC/MS), to compare supernatant samples from C. jejuni M1 wild type and flagella-deficient (flgG mutant) strains to identify putative novel proteins secreted via the FT3SS. Genes encoding proteins that were candidates for flagellar secretion, derived from the LC/MS and SILAC datasets, were deleted. Infection of human CACO-2 tissue culture cells using these mutants resulted in the identification of novel genes required for interactions with these cells. This work has shown for the first time that both CJM1_0791 and CJM1_0395 are dependent on the flagellum for their presence in supernatants from C. jejuni stains M1 and 81–176.Biological significanceThis study provides the most complete description of the Campylobac er jejuni secretome to date. SILAC and label-free proteomics comparing mutants with or without flagella have resulted in the identification of two C. jejuni proteins that are dependent on flagella for their export from the bacterial cell
Active lower order mode damping for the four rod LHC crab cavity
No full textAbstractThe high luminosity upgrade planned for the LHC requires crab cavities to rotate bunches into alignment at the interaction points. They compensate for a crossing angle near 500μrad. It is anticipated that four crab cavities in succession will be utilized to achieve this rotation on either side of each IP in a local crossing scheme. A crab cavity operates in a dipole mode but always has an accelerating mode that may be above or below the frequency of the operating mode. Crab cavities are given couplers to ensure that unwanted acceleration modes are strongly damped however employing standard practice these unwanted modes will always have some level of excitation. Where this excitation has a random phase it might promote bunch growth and limit beam lifetime. This paper sets out a method for active control of the phase and amplitude of the unwanted lowest accelerating mode in the crab cavities. The paper investigates the level of suppression that can be achieved as a function cavity quality factor and proximity to resonance
Adaptación transcultural del cuestionario acerca de la función intestinal (LARS Score) para su aplicación en pacientes operados de cáncer de recto medio y bajo
No full textResumenIntroducciónEl tratamiento en el cáncer de recto ha progresado en la última década. Hoy es factible ofrecer una cirugía con preservación de esfínteres, realizando anastomosis colorrectales bajas o anastomosis coloanales. Esto ha determinado que muchos pacientes desarrollen disfunción intestinal que puede llegar a ser severa, agrupando una serie de alteraciones que se conocen como síndrome de resección anterior baja.ObjetivoEfectuar una adaptación cultural de la versión 1.0 en español neutro del cuestionario acerca de la función intestinal o Low Anterior Resection Syndrome Score (LARS Score), efectuando traducción, comparación de traducciones, traducción inversa y prueba piloto.ResultadosLos resultados obtenidos de la prueba piloto revelan que la población encuestada logró comprender el instrumento, por lo que no se realizaron modificaciones posteriores.ConclusiónSe cuenta con una versión adaptada del cuestionario LARS para ser usada en Chile, la cual puede someterse a procesos de validación y establecer las características psicométricas para ser usada en pacientes con cáncer de recto operados.AbstractIntroductionThe treatment of rectal cancer has progressed in the past decade. Nowadays, it's feasible to provide sphincter sparing surgery with low colorectal anastomosis or coloanal anastomosis. This has determined that many patients develop intestinal dysfunctions that can become severe, grouping a number of disorders known as low anterior resection syndrome.ObjectiveTo perform a cultural adaptation of the version 1.0 questionnaire about bowel function or Low Resection Syndrome Score (LARS Score) in neutral Spanish, making a translation, comparing translations, back translation and pilot test.ResultsThe results of the pilot test showed that the population surveyed understood the instrument, so that no further modifications were made.ConclusionWe now have an adapted version of the LARS questionnaire for use in Chile, which can undergo validation processes to establish the psychometric characteristics for use in patients with rectal cancer surgery
Prevalence and associated factors of stress, anxiety and depression among medical Fayoum University students
No full textAbstractBackgroundMental health issues are increasing in severity and number on college campuses. Improving adolescent mental well-being remains a challenge for most societies.ObjectivesThe objectives of this study was to study the prevalence of psychological mood disorders and its association with some factors.MethodsA cross-sectional-questionnaire based study was conducted among medical students in Fayoum University. Propensity to Psychological mood disorders was assessed by using a short version Depression, Anxiety and Stress Scale-21 (DASS-21), along with a pretested Sociodemographic questionnaire.ResultsA total of 442 students participated in the study with the mean age of 20.15±1.9years. Overall, the prevalence of stress, anxiety and depression with various degrees was 62.4%, 64.3%, and 60.8% among studied sample respectively. Higher stress and anxiety scores were significantly associated with female sex, older age, and BMI⩾25kg/m2. Higher depression score was associated with increasing age, low socioeconomic standard and among students from other governorates.ConclusionA substantial proportion of medical students are suffering from depression, stress, and anxiety. Female sex, increasing age, overweight and obesity are significant associated factors. Further studies need to be carried to identify other associated factors related to academic medical education