Kontrastaine kahjulikud toimed, kontrastainenefropaatia

Röntgenkontrastaine kasutamine radioloogilistel protseduuridel võib põhjustada nefropaatiat ja neerupuudulikkust. Kontrastaine(KA)-nefropaatia on neerufunktsiooni kahjustus, mis ilmneb 48–72 tunni jooksul pärast KA manustamist ja väljendub seerumi kreatiniini sisalduse suurenemises vähemalt 25%ni algväärtusest, kui teised neerufunktsiooni halvenemise põhjused on välistatud. Eesti Arst 2007; 86 (9): 659-66

Glomerulonefriit – märkamatult progresseeruv neerukahjustus

Glomerulonefriidid on põhiliselt immuungeneesiga neeru glomerulaarsed haigused, mille puhul esineb sageli ka põletikuline kahjustus. Glomerulonefriitide diagnostikas on oluline uriini analüüs, kus võib leida erinevas astmes proteinuuriat, hematuuriat, lisaks võib patsiendil esineda hüpertensioon ja neerupuudulikkus. Haiguse algstaadiumis võivad patsiendil igasugused kaebused puududa ning see põhjustab sageli diagnoosi ja ravi hilinemise. Haiguse süvenemise korral ohustavad patsienti nefrootiline sündroom ja selle tüsistused ning terminaalne neerupuudulikkus. Glomerulonefriidi lõpliku diagnoosi, ravitaktika ja prognoosi hindamise aluseks on neerubiopsia. Primaarse glomerulonefriidi eri vormid vajavad erinevat ravi, kuid haiguse progresseerumist ja neerukahjustuse süvenemist lõppstaadiumis neerupuudulikkuseni on sageli võimalik aeglustada. Paljud patsiendid ei vaja pidevat aktiivset ravi, kuid remissioonifaasis on vajalik haigete jälgimine ja regulaarne kontroll (uriini analüüs, vererõhk, neerufunktsioon), sest ägenemine ei pruugi esialgu tekitada vaevusi, mistõttu patsient ei pöördu ise õigel ajal arsti poole ja ravi võib hilineda. Eesti Arst 2009; 88(5):324−32

Biliary motility in health and disease

This thesis examined several aspects of biliary physiology, the incidence of the post-cholecystectomy syndrome and changes in sphincter of Oddi (SO) motility following cholecystectomy.Gallbladder emptying starts before the stomach begins to empty and before nutrients reach the small bowel to stimulate cholecystokinin (CCK) release. The mechanism of the early phase of gallbladder emptying is unclear. Gallbladder emptying was examined in a group of volunteers after ingestion of a fatty meal, a sham meal and gaseous gastric distension. The early phase of gallbladder emptying was found to be associated with CCK release. In most cases, gaseous gastric distension and sham feeding did not cause significant gallbladder emptying or CCK release but in a minority of individuals early gallbladder emptying followed sham feeding and this was associated with increased plasma CCK concentrations. Early release of CCK could be mediated by a combination of vagal-cholinergic stimulation and neuro-hormonal reflex in response to bombesin release by intragastric nutrients.The effect of nitric oxide (NO) upon gallbladder motility was examined in a group of volunteers after fatty meal during infusion with NO donors (glyceryltrinitrate and sodium nitroprusside), normal saline and hydralazine as a hypotensive control agent. Postprandial gallbladder emptying was significantly reduced during infusion with the NO donors. This inhibitory effect was independent of hypotension and CCK release. This inhibitory effect of NO donors was also observed on isometric contraction of isolated gallbladder muscle strips.The effect of NO on the SO was examined by topical infusion of glyceryltrinitrate to the ampulla during SO manometry. Basal tone and phasic activity were both suppressed. This finding may have therapeutic application for stone extraction and duct cannulation during endoscopic retrograde cholangiopancreatography.Symptoms were assessed in 100 patients before and six months after laparoscopic cholecystectomy (LC) with standard questionnaire. 13% of patients had persistent biliary symptoms. Pre-operative abdominal bloating and consumption of antidepressant were found to be significantly more prevalent in these subjects compared to padents who had successful operations.SO dysfunction is a cause of post-cholecystectomy pain. We hypothesised that LC could destroy cholecysto-sphincteric nerves leading to SO dysfunction. SO manometry was performed in a group of volunteers before and six months after LC. Following LC, the SO was not inhibited by CCK. This could lead to relative post-prandial biliary obstruction and result in post-cholecystectomy pain in susceptible individuals and to dilatation of the common bile duct.Several issues and concepts arose from the work of this thesis. The mechanism underlying the early release of CCK needs further investigation. The clinical relevance of the effects of NO upon biliary tract motility remains to be explored. It is hoped that future research in this area will help to clarify these issues

ADHD: can reinforcement resolve the problem?

Sergeant, J.A. [Promotor]Oosterlaan, J. [Copromotor

Exploring the Antecedents of Organizational Citizenship Behavior in Knowledge-based Virtual Communities

This study aims to examine what kinds of behaviors constitute virtual community citizenship behaviors (VCCB) and what factors influence community members\u27 willingness to engage in VCCB. In this paper, I propose a theoretical framework consisting of the main antecedents of VCCB (affective commitment, structural embeddedness and membership tenure) and a multi-dimensional VCCB construct (altruism, civic virtue, consciousness, courtesy and loyalty). Additionally, I develop a measure for assessing VCCB. Data are collected from an online discussion forum (The Grad Cafe) to address the research questions of this study. Results indicate that only affective commitment is found to be significantly predictive of the virtual community citizenship behaviors. Finally, implications and recommendations for practitioners in terms of improving the effective functioning of virtual community through the lens of VCCB are described

Tagasiside strateegiate ning geeni GABRA2 (rs279858) pidurdava potentsiaali mõju petukäitumisele

Some research has been done on the effect of heritability of the deceptive behaviour, but very little is known about the effect of specific genes. In this study the effect of gene GABRA2 SNP rs279858 on the propensity to lie and on reaction time (RT) in the ‘Circle Game’ was investigated. Significant main effect of rs279858 on RT in ‘Circle Game’ and a significant interaction of rs279858 and sex on the propensity to lie were discovered. A significant learning effect in the ‘Circle Game’ was also found and a significant RT deception effect described in numerous previous studies was confirmed

Exploring the Antecedents of Organizational Citizenship Behavior in Knowledge-based Virtual Communities

This study aims to examine what kinds of behaviors constitute virtual community citizenship behaviors (VCCB) and what factors influence community members\u27 willingness to engage in VCCB. In this paper, I propose a theoretical framework consisting of the main antecedents of VCCB (affective commitment, structural embeddedness and membership tenure) and a multi-dimensional VCCB construct (altruism, civic virtue, consciousness, courtesy and loyalty). Additionally, I develop a measure for assessing VCCB. Data are collected from an online discussion forum (The Grad Cafe) to address the research questions of this study. Results indicate that only affective commitment is found to be significantly predictive of the virtual community citizenship behaviors. Finally, implications and recommendations for practitioners in terms of improving the effective functioning of virtual community through the lens of VCCB are described

Molecular Dynamics Simulation of Soft Grains: Malaria-Infected Red Blood Cells Motion within Obstructed 2-D Capillary Vessel

Molecular dynamics has been widely used to numerically solve equation of motion of classical many-particle system. It can be used to simulate many systems including biophysics, whose complexity level is determined by the involved elements. Based on this method, a numerical model had been constructed to mimic the behaviour of malaria-infected red blood cells within capillary vessel. The model was governed by three forces namely Coulomb force, normal force, and Stokes force. By utilizing two dimensional four-cells scheme, theoretical observation was carried out to test its capability. Although the parameters were chosen deliberately, all of the quantities were given arbitrary value. Despite this fact, the results were quite satisfactory. Combined with the previous results, it can be said that the proposed model were sufficient enough to mimic the malaria-infected red blood cells motion within obstructed capillary vessel. Keywords: molecular dynamics, two-dimensional model, red-blood cell motion, malariaComment: 4 pages, 4 figures, 3 table, conference paper (presented the International Symposium on BioMathematics (Symomath) 2013, October 27-29, 2013, Bandung, Indonesia