284 research outputs found
Current concept on the pathogenesis of inflammatory bowel disease-crosstalk between genetic and microbial factors: Pathogenic bacteria and altered bacterial sensing or changes in mucosal integrity take "toll"?
The pathogenesis of inflammatory bowel disease (IBD) is only partially understood. Various environmental and host (e.g. genetic-, epithelial-, immune and non-immune) factors are involved. It is a multifactorial polygenic disease with probable genetic heterogeneity. Some genes are associated with IBD itself, while others increase the risk of ulcerative colitis (UC) or Crohn's disease (CD) or are associated with disease location and/or behaviour. This review addresses recent advances in the genetics of IBD. The article discusses the current information on the crosstalk between microbial and genetic factors (e.g. NOD2/CARD15, SLC22A46A5 and DLG5). The genetic data acquired in recent years help in understanding the pathogenesis of IBD and can identify a number of potential targets for therapeutic intervention. In the future, genetics may help more accurately diagnose and predict disease course in IBD
Metastabilis mikroemulziók alkalmazására épülő rétegkezelési eljárások elméleti megalapozása = Theoretical study and development of new well treatment methods based on application of metastable microemulsions
A kutatás célját olyan szelektív fluidumáramlást biztosító rétegkezelési eljárás kidolgozása képezte, ami alkalmas a kőolaj- és gáztermelő kutakban a vízhányad csökkentésére, illetve vízbesajtoló kutakban az áramlási profilok kiegyenlítésére. Az alap és alkalmazott kutatási program keretében különböző, szilikon vegyületeket, gemini tenzideket és zsírsavakat tartalmazó, szerves külső fázisú mikroemulziós rendszerek kifejlesztésére került sor, amelyek közös vonása, hogy vízzel elegyedve nagy viszkozitású, rétegkörülmények között immobilis gátképző fázissá alakulnak át. Ezen kivételes tulajdonságaiknál fogva a gátképző hatás spontán módon, csak a nagy víztelítettségi zónákban, pórusterekben jön létre, miközben a kőolaj vagy földgáz kúttalphoz történő beáramlása változatlan marad. Ebből következik, hogy a gátképző hatás létrejötte független a besajtolási protokolltól és a kezelő folyadékok penetrációs mélységétől. Az összehasonlító vizsgálatok szerint az ultrakönnyű és könnyű szénhidrogén (petróleum) külső fázisú mikroemulzió egyedülálló módon használható fel a gázmezőkben és földalatti gáztárolókban működő termelő kutak víztermelésének korlátozására. Az elvében és gyakorlati megvalósításában újszerű, szabadalom szintű technológiai megoldás olcsó, széles körben alkalmazott és a környezetvédelmi előírásokat messzemenően kielégítő vegyi anyagok alkalmazására épül. A módszer hatékony megoldást kínál egy eddig nem, vagy csak korlátozottan megoldott gáztermelési problémára. | Development of well treatment methods aimed at improving the selective fluid flow in oil and gas producing wells and flow profile control in water injection wells was the main goal of the research project. In frame of the fundamental and applied research, different microemulsions and containing silicon compounds, gemini tensides and fatty acid esters were studied, which formed high viscosity, immobile phases in porous media when contacting (mixing) with water. That outstanding feature of microemulsions is that the blocking effect spontaneously ensues only in those reservoir spaces and zones where the water saturation is high; meanwhile the main flow path of hydrocarbon fluids remains intact from radical permeability reduction. As a result, the mechanism of the selective water shutoff is independent of injection protocol and placement techniques, which often jeopardize the efficiency of known well treatments. Based on the comparative studies, the ultra light and light microemulsions formed by petroleum external phase is a unique treating fluid to restrict water production in gas wells operating in gas field and underground gas storage facilities. The novel method being unprecedented in fundamental and practical concept alike will be claimed soon as patent, meets the most serious REACH preconditions and is based on cheap and easily available materials
Rétegkárosodást okozó vízkövek képződési mechanizmusa tömbfázisban és porózus közegben = Scale Formation Mechanism in Bulk Phase and Porous Media and Its Effect on Formation Damage
A kutatás középpontjában a BaSO4 és SrSO4 típusú vízkövek eltávolítására alkalmas, poliamino-karbonsavakat tartalmazó kezelőoldatok optimálása állt. A különböző komplexképző vegyületet és szerves valamint szervetlen pH szabályozó adalékanyagokat tartalmazó oldatokban a BaSO4 és SrSO4 egyensúlyi oldhatóságának, az oldószer szelektivitásának, valamint az oldatok természetes porózus közegben való áramlási sajátságainak meghatározása képezte az összehasonlítás, értékelés alapját. A kísérleti eredmények alapján megállapítást nyert, hogy a poliamino-karbonsavak alkalmazhatósága eltérő sorrendet követ, ha az értékelés műszaki/technikai szempontok vagy gazdaságossági/költségigény alapján történik. Az ellentmondások ellenére ipari felhasználásra az EDTA és a DTPA alkalmazása javasolható. Az alapkutatás feltárta azt a meglepő jelenséget is, hogy a szokásosan alkalmazott szervetlen alkáliák mellett a poliamino-karbonsavakkal a vízkőképződés, károsító hatás a várakozás ellenére nem szüntethető meg. Ennek oka az alkálifémionok által kiváltott ioncsere és az alkáliföldfém-karbonátok indukált in-situ leválása. Ezzel szemben a szerves lúgokat, alkilamidokat tartalmazó poliamino-karbonsav oldatok alkalmazásakor azok pozitív hatását rontó, káros jelenség nem lép fel. A pH szabályozást eredményező dimetil- és trimetil-amin alkalmazásán alapuló technológia új távlatot nyithat a BaSO4 és SrSO4 okozta rétegkárosodás hatékony mérséklésére, megszüntetésre. | The laboratory studies were focused on evaluation of different dissolvers for barite sag/fines or barium sulfate and strontium sulfates scales. The extensive research program was extended to six polyamino carboxylic acids using both inorganic and organic pH controlling agents. Their dissolution efficiency was determined in batch type equilibrium tests and flow experiments using natural porous cores derived from the Algyő field, Hungary. Based on the experimental findings it was concluded that the sequence of dissolution potential is different if the results are evaluated on technical or economic basis. First, it was demonstrated that SrSO4 type scales, sags and fines can be removed more efficiently from porous media than BaSO4 or barite. It was also shown that the DTPA, and particularly EDTA, are sometimes not the best dissolvers when technical considerations are only enforced, but application may often be justified by the total expenditure of the technology. The stunning phenomena, viz. permeability deterioration, observed in flow tests indicated crucial side effect in when conventional pH controlling agents. That unfavorable effect could be eliminated by secondary and tertiary alkylamines, particularly dimethyl- and trimethylamines used as pH controlling agents. Results of that systematic analysis may open new vistas in mitigation of formation damage caused by BaSO4 or SrSO4 and accelerate the search for more effective mixtures of complex-forming dissolvers
Striking elevation in the incidence and prevalence of inflammatory bowel disease in a province of Western Hungary between 1977-2001
AIM: An investigation into inflammatory bowel disease and colorectal cancer in Veszprem Province was conducted from 1977 to 2001.
METHODS: Both hospital and outpatient records were collected and reviewed comprehensively. The majority of patients were followed up regularly.
RESULTS: The population of the province was decreased from 386,000 to 376,000 during the period. Five hundred sixty new cases of ulcerative colitis (UC), 212 of Crohn's disease (CD), and 40 of indeterminate colitis (IC) were diagnosed. The incidence rates increased from 1.66 to 11.01 cases per 100,000 persons for UC, from 0.41 to 4.68 for CD and from 0.26 to 0.74 for IC. The prevalence rate at the end of 2001 was 142.6 for UC and 52.9 cases per 100,000 persons for CD. The peak onset age in UC patients was between 30 and 40 years, in CD between 20 and 30 years. A family history of IBD was present in 3.4 % in UC and 9.9 % in CD patients. Smoking increased the risk for CD (OR=1.98) while it decreased the risk for UC (OR=0.25). Twelve colorectal carcinomas were observed in this cohort, the cumulative colorectal cancer risk after 10 years in UC was 2%, after 20 years 8.8%, after 30 years 13.3%.
CONCLUSION: The incidence and prevalence rates of IBD have increased steadily in Veszprem Province, now equivalent to that in Western European countries. Rapid increase in incidence rates supports a probable role for environmental factors. The rate of colorectal cancers in IBD is similar to that observed in Western countries
Comparison of Different Turbulence Models and Wall Treatment Methods for Vehicle Aerodynamics Investigations
In this paper two different turbulence models and wall treatment methods were investigated with Computational Fluid Dynamics (CFD) method. The used geometry for the research was the Ahmed body. The Ahmed body is a widely used geometry in vehicle aerodynamics investigations. The geometry represents a simplified vehicle, which allows the researchers to make examinations with moderate resources. The simulations were made in Ansys Fluent. The environment of the simulation was built to optimize for maximum 8 GB RAM. The paper examines the difference between the k-ω SST and the k-ε turbulence models in the case of low and high Reynolds number wall treatment methods. This could be useful because the high Reynolds number wall treatment method needs less computational capacity based on that, its required y+ range is between 30 and 300. While in the case of the low Reynolds wall treatment method the required y+ range is below 10, which could increase the cell count. The results from the CFD simulation will be compared to each other and with measured data. The aim of the research is to get information about behaviour of the examined turbulence models in the case of low and high Reynolds number wall treatment methods
Gene polymorphisms in primary biliary cirrhosis: association with the disease and hepatic osteopathy
Genetic factors have been implicated in the pathogenesis of osteoporosis, a common disorder in primary biliary cirrhosis (PBC). Estrogen receptor-alpha gene (ER-�), vitamin-D-receptor gene (VDR) and IL-1-receptor-antagonist gene (IL-1RN) are all attractive candidates for osteoporosis susceptibility. Furthermore insulin-like growth factor-I (IGF-I) gene microsatellite repeat polymorphism was found to be associated with osteoporosis in some studies and collagen-I�1 (COLIA1) Sp1 s allele was associated with lower bone mineral density (BMD) in one study in PBC. IGF-I treatment restored osteopenia and reduced fibrogenesis in experimental cirrhosis. In this study we summarize our results on polymorphisms of the above genes and bone disease in Hungarian PBC patients.
Patients and methods: 70 female patients with PBC were enrolled (age:57.6yrs, range:37-76yrs, each AMA-M2 positive, stage II-IV). 139 age-matched female subjects served as controls (age: 55.9 yrs, range:43-72 yrs). COLIA1 Sp1 and IGF-I microsatellite polymorphisms were determined by PCR in all patients and controls. VDR BsmI, IL-1RN variable-number tandem repeat (VNTR) and ER-� PvuII and XbaI polymorphisms were detected in 33 patients and controls. BMD was measured by dual energy x-ray absorptiometry (Lunar,Prodigy,USA) in lumbar spine (LS) and femoral neck (FN).
Results: There was no difference in IGF-I microsatellite repeat polymorphism (192/192=34.2%, 194/192=28.6%, other=37.2%) and COLIA1 Sp1 polymorphism (SS=72.9%, Ss=22.8% and ss=4.3%) and IL-1 VNTR polymorphism between PBC
patients and controls, however, the COLIA1 Sp1 s allele was significantly less frequent in patients with PBC (p=0.038). The genotype frequency of VDR BsmI (BB=57.5%, Bb=33.3%, bb=9.1%, p=0.01) and ER-a PvuII (PP=18.2%, Pp=75.6%, pp=6.2%, p=0.03) and XbaI (XX=9.1%, Xx=90.9%, xx=0%, p=0.0003) of the patients was different from that of the control group, with higher frequency of the BB, Pp and Xx
genotypes in PBC. Osteoporosis (t score<-2.5) was detected in 22 patients (31.4%). Osteoporotic patients were elder and had longer disease history (p=0.01 for both). An
association was found between the IGF-I genotypes and ODM data, the 192/192 genotype was associated with higher FN Z-score compared to other genotypes (p=0.036).
Conclusions: In contrast to previous studies the COLIA1 Sp1 s allele was less frequent in patients with PBC, and its presence was not associated with BMD. We confirmed previous findings on higher frequency of VDR BsmI BB genotype in patients with PBC. The ER-α PvuII and XbaI Pp and Xx genotypes were more frequent in PBC patients, while IL-1RN VNTR and IGF-I microsatellite repeat polymorphism was not
different. Since IGF-I polymorphism was associated to BMD, it may be hypothesized that not COLIA1 but IGF-I together with other genetic and environmental factors may be involved in the complex regulation of BMD in PBC
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