48 research outputs found
WATER SUPPLY NETWORK MODEL FOR OPERATION CONTROL
The well-known methods of elaboration of optimal operation strategies of water supply
systems are based on quasi-stationary simulation. The aim of substituting models is the
significant decrease of the simulation's time and memory demand. In the first applications
the determination of the parameters of the substituting model was based on the result
of the analysis made on the detailed system. This substituting model was suitable to
work out the optimal operation for this system but it was not generalizable. The new
method of elaboration of substituting models is based on a new structure of the network
and consumption, and the regression analysis to calculate the parameters of the model.
The identification of the substituting models is based on the comparison of the typical
characteristic curves and on the comparison of the simulation results of the original and
the substituting models
Urinary Biomarkers TIMP-2 and IGFBP7 Early Predict Acute Kidney Injury after Major Surgery
Objective
To assess the ability of the urinary biomarkers IGFBP7 (insulin-like growth factor-binding protein 7) and TIMP-2 (tissue inhibitor of metalloproteinase 2) to early predict acute kidney injury (AKI) in high-risk surgical patients.
Introduction
Postoperative AKI is associated with an increase in short and long-term mortality. Using IGFBP7 and TIMP-2 for early detection of cellular kidney injury, thus allowing the early initiation of renal protection measures, may represent a new concept of evaluating renal function.
Methods
In this prospective study, urinary [TIMP-2]Ă—[IGFBP7] was measured in surgical patients at high risk for AKI. A predefined cut-off value of [TIMP-2]Ă—[IGFBP7] >0.3 was used for assessing diagnostic accuracy. Perioperative characteristics were evaluated, and ROC analyses as well as logistic regression models of risk assessment were calculated with and
without a [TIMP-2]Ă—[IGFBP7] test.
Results
107 patients were included in the study, of whom 45 (42%) developed AKI. The highest median values of biomarker were detected in septic, transplant and patients after hepatic surgery (1.24 vs 0.45 vs 0.47 ng/l2/1000). The area under receiving operating characteristic curve (AUC) for the risk of any AKI was 0.85, for early use of RRT 0.83 and for 28-day mortality
0.77. In a multivariable model with established perioperative risk factors, the [TIMP-2]Ă—[IGFBP7] test was the strongest predictor of AKI and significantly improved the risk assessment (p<0.001).
Conclusions
Urinary [TIMP-2]Ă—[IGFBP7] test sufficiently detect patients with risk of AKI after major non-cardiac surgery. Due to its rapid responsiveness it extends the time frame for intervention to prevent development of AKI
Membran ösztrogén receptorok sejtszintű hatásainak vizsgálata human uterus hormonális szabályozásában és daganatos elváltozások patomechanizmusában = Cellular function of membrane estrogen receptors in hormonal control of human uterus and in pathomechanism of tumor formation
Patkány uterusban E2 kezelĂ©s hatására az Akt foszforiláciĂłja a Ser473 Ă©s a FOXO1 Ser 256 csoportokon fokozĂłdik, amit ICI 182, 780 Ă©s Wortmannin gátol. Az Akt expressziĂł nem változott, a pAkt myomában jelentĹ‘sen fokozĂłdott. A pAkt a proliferáciĂłs fázisban volt a legmagasabb. Myomákban a ciklus alatti Akt foszforiláciĹ‘ fokozĂłdásával párhuzamosan az ER foszforiláciĂłja, a cyclin D1 Ă©s Bcl-2 proteinek expressziĂłja is fokozĂłdott. Myomában az inaktĂv pPTEN-Ser380 fokozĂłdott a pAkt változásokkal megegyezĹ‘ mĂłdon. A myometriumokban pPTEN szintekben ciklus fázisoktĂłl fĂĽggĹ‘ Ă©s pAkt-tĂłl fĂĽggetlen változásokat találtunk. A PTEN ĂnaktiváciĂłja Ă©s Akt aktiváciĂłja myomában a menstruáciĂłs ciklus alatt párhuzamosan változott. A pFOXO1 (Ser256) protein szintje magasabb volt myomában Ă©s változott a menstruáciĂłs ciklus alatt ill. menopauzában. Myomában a pFOXO-Ser256 elsĹ‘sorban a magban volt kimutathatĂł, feltehetĹ‘en a nucleocytoplasmatikus transport zavara miatt, aminek az oka valĂłszĂnűleg a párhuzamosan meghatározott 14-3-3 protein expressziĂł csökkenĂ©se.Myomában a megváltozott PTEN/ER/PI3K/Akt/FOXO1 jelátvitel a sejtekben sejttĂşlĂ©lĂ©st biztosĂtĂł (prosurvival) programok elĹ‘tĂ©rbe kerĂĽlĂ©sĂ©t serkenti. Az ERalpha expressziĂł postmenopauzás endometriumban irregulárisan változott. Az ER(Ser167) Ă©s Akt foszforiláciĂłja magasabb vĂ©r E2 szintnĂ©l (>50pmol/L) fokozĂłdott. A pAkt pozitĂvan korrelált se E2 koncentráciĂłval (r: 0.811, p50pmol/L). The pAkt (Ser473) was abundant in endometrium of women with higher (>50 pmol/L) E2 concentration. The pAkt significantly correlated with Se E2 (r: 0.811, p<0.001) and pERalpha (r: 0.879, p< 0.001)
Opioid peptidek sejtproliferációt gátló hatásmechanizmusának további vizsgálata uterusban = Further studies on the mechanism of the cell proliferation-inhibitory action of opioid peptides in the uterus
Az opioid peptidek sejtproliferáciĂłt gátlĂł hatását vizsgáltuk tenyĂ©sztett patkány Ă©s humán uterus sejtekben. MĂ©rĂ©seinkhez sejtszámlálást, DNS meghatározást, MTT sejtproliferáciĂłs assay-t Ă©s immunoblot mĂłdszereket alkalmaztunk. Adataink alapján az opioid peptidek patkány uterus sejtek osztĂłdását gátlĂł hatásában kĂ©t eltĂ©rĹ‘ fázis kĂĽlönĂthetĹ‘ el az egyedfejlĹ‘dĂ©s alatt, melyeket egy Ă©rzĂ©ketlen periĂłdus választ el egymástĂłl. Az opioid peptid Ă©s progeszteron receptor rendszerek között kĂ©tirányĂş kapcsolat működik felnĹ‘tt patkány uterus sejtek, valamint humán myometrium Ă©s endometrium sejtek szaporodásának gátlĂł jellegű szabályozásában. Fiatal, Ă©retlen patkányok uterus sejtjeiben e molekuláris kapcsolat mĂ©g nem mutathatĂł ki. A naloxon- Ă©s az RU486-hatás idĹ‘fĂĽggĂ©sĂ©nek eltĂ©rĂ©sei alapján e kĂ©tirányĂş kapcsolat eltĂ©rĹ‘ támadáspontokon keresztĂĽl valĂłsulhat meg. Az opioid peptidek sejtosztĂłdást gátlĂł mechanizmusa Ă©s az Ăłpiát-progeszteron kölcsönhatás működĹ‘kĂ©pes humán leiomyoma sejtekben is. Azonban [D-Met2-Pro5]-enkefalinamid (ENK) a leiomyoma sejtek nem-stimulált szaporodását is gátolta, Ă©s az ENK Ă©s DAMGO mellett itt [Met5]-enkefalin is hatásosnak bizonyult a 7 napos patkány uterusban leĂrtakhoz hasonlĂłan. A myometrium sejtekben találtakkal ellentĂ©tben, RU486 önmagában nem serkentette a leiomyoma sejtek a szaporodását, azonban az ENK gátlĂł hatását kivĂ©dte. Az eltĂ©rĂ©sek a sejtosztĂłdás szabályozásának rĂ©szleges dedifferentáciĂłját mutathatják, ami a pathomechanizmusban is szerepet játszhat. | The inhibitory action of opioid peptides on the proliferation of cultured rat and human uterine cells was investigated. Cell counting, DNA determination, MTT cell proliferation assay and immunoblot technique were used to obtain data. Our data demonstrate two different phases of the inhibitory action of opioid peptides on rat uterine cell proliferation during ontogeny with an insensitive interval in between. A bidirectional interaction exists between the opioid peptide and progesterone signaling systems in the inhibitory regulation of cell proliferation in adult rat uterus and in human myometrium and endometrium. Uteri of immature rats lack this molecular connection. The difference between the time dependence of naloxon and RU486 actions suggests that, this bidirectional action is realized by targeting different elements in the mechanism of action. The opioid peptides' growth inhibitory system and the opiate-progesterone interaction are functional in human uterine leiomyoma cells. However, [D-Met2-Pro5]-enkephalinamide (ENK) inhibited the non-stimulated proliferation of leiomyoma cells and, besides ENK and DAMGO, [Met5]-enkephalin was effective as well, similar to that of found in 7-day-old rats. In contrast to myometrial cells, RU486 alone did not stimulate the proliferation of leiomyoma cells however; it antagonized the inhibitory effect of ENK. These alterations suggest a partial dedifferentiation of cell-division regulation and, might play a role in the pathomechanism
A tĂ©ri tájĂ©kozĂłdás Ă©s szorongás kapcsolatának bio-pszicholĂłgiai megközelĂtĂ©se. = Relationship between spatial orientation and anxiety: A psychological approach.
MegállapĂtottuk, hogy kompjuter által lĂ©trehozott virtuális, valamint valĂłs ĂştvesztĹ‘ arĂ©nában, egyĂ©ni válaszminta formájában nĂ©gy, a tanulás menetĂ©ben kĂĽlönbözĹ‘ funkciĂłt ellátĂł navigáciĂłs stratĂ©gia regisztrálhatĂł: a körkörös keresĂ©s, pásztázás, lokomĂłciĂłt nem tartalmazĂł vizuális letapogatás Ă©s thigmotaxis. Ismeretlen helyen elĹ‘bb a körözĹ‘ Ă©s a falĂ©rintĹ‘ stratĂ©gia működik, majd fokozatosan a pásztázás válik aktĂvvá. A falĂ©rintĹ‘ stratĂ©gia lĂ©nyege, hogy az arĂ©na által körbezárt tĂ©r belsĹ‘ terĂĽletĂ©nek exploráciĂłjára vonatkozĂł instrukciĂł ellenĂ©re elĹ‘ször a cĂ©ltárgy távolabbi környezetĂ©t vizsgálja meg a szemĂ©ly (határdefinĂciĂł), majd a globális struktĂşra biztonságos ismerete után közelĂti csak meg a cĂ©ltárgyat. Feltártuk, hogy a thygmotaxis humán egyedeknĂ©l is megjelenik Ă©s fontos rĂ©szĂ©t kĂ©pezi a pánik agorafĂłbiátĂłl szenvedĹ‘ szemĂ©lyek extraterritoriális viselkedĂ©sĂ©nek. Az ilyen idegen helyen kivitelezett viselkedĂ©s legfontosabb jellemzĹ‘je az aktuális navigáciĂłs jelzĂ©sek kontextustĂłl valĂł megfosztása (dekontextualizáciĂł). Az agy strukturális Ă©s funkcionális állapotát vizsgálva (MR volumetria Ă©s fMRI) megállapĂtottuk, hogy a dekontextualizáciĂł Ă©s a fĂ©lelem által provokált tájĂ©kozĂłdási zavarok, kĂĽlönösen az egocentrikus Ă©s az allocentrikus referencia választás integráciĂłja, nagy mĂ©rtĂ©kben kötĹ‘dik a jobb oldali hippokampusz poszterior rĂ©szĂ©nek strukturális Ă©psĂ©gĂ©hez ill. magas szintű aktiváciĂłjához. | We have stated: both computer generated virtual and real arena maze may be adequate tools to assess an individually consistent navigation pattern that involves four different exploration strategies: circling, enfilading, visual scanning without locomotion, and thigmotaxis. Exploring a strange and potentially dangerous space in the first part of the navigation the circling pattern is activated after gradually the enfilading becomes the dominant strategy. The more essential component of thigmotaxis is to avoid the central zone of the open field arena and to prefer the border of the enclosed place. During thigmotaxis the subject, against the instruction, in the first part of the navigation records safety knowledge on the global structure of the current space and after approaches the affected target. We suggested that thigmotaxis is exactly assessed in humans and an essential component of the panic and agoraphobic subject's extraterritorial behavior. The panic and agoraphobic subject overcoming a strange environment inclined cognitively to avoid the essential navigation cues and reduces the articulation of the current spatial context (decontextualization). Assessing the brain structural and functional state by MR and fMRI scan has revealed fear provoking spatial navigation disorders and the dexontextualization of the current context together with the disorder of egocentric and allocentric reference construction associated with the volumetric and functional data of the right posterior hippocampus
Renal Recovery after the Implementation of an Electronic Alert and Biomarker-Guided Kidney-Protection Strategy following Major Surgery
Background:
The facilitation of early recovery of acute kidney injury (AKI) is an important step to improve outcome, particularly because of the limited therapeutic interventions currently available for AKI. The combination of an electronic alert and biomarker-guided kidney-protection strategy implemented in the routine care may have an impact on the incidence of early complete reversal of AKI after major non-cardiac surgery.
Methods:
We studied 294 patients in two cohorts before (n = 151) and after protocol implementation (n = 143). Data collection required 6 months for each cohort. The kidney-protection protocol included an electronic alert to detect patients who were eligible for urinary biomarker [TIMP2 Ă— IGFBP7]-guided kidney-protection intervention. Intervention was stratified according to three levels of immediate AKI risk: low, moderate, and high. After intervention, postoperative changes in the glomerular filtration rate (eGFR) were identified with a tracking software that included an alert for nephrology consultation if the eGFR had declined by >25% from the preoperative reference value. Primary outcome was early AKI recovery, i.e., the complete reversal of any AKI stage to absence of AKI within the first 7 postoperative days.
Results: Protocol implementation significantly increased the recovery of AKI (36/46, 78% compared to control 27/48, 56%, (p = 0.025)) and reduced the length of the ICU stay (p < 0.001). There was no significant difference in the overall incidence of all AKI and moderate and severe AKI in the first 7 postoperative days: 46/143 (32%) and 12/151 (8%) in the protocol implementation group compared to 48/151 (32%) and 18/151 (12%) in the historical control group. Patients with AKI reversal within the first 7 postoperative days had lower in-hospital mortality than patients without AKI reversal.
Conclusions:
Implementing a combined electronic alert and biomarker-guided kidney-protection strategy in routine care improved early recovery of AKI after major surgery
The effects of the semirecumbent position on hemodynamic status in patients on invasive mechanical ventilation - prospective randomized multivariable analysis
INTRODUCTION: Adopting the 45° semirecumbent position in mechanically ventilated critically ill patients is recommended, as it has been shown to reduce the incidence of ventilator-associated pneumonia. Although the benefits to the respiratory system are clear, it is not known whether elevating the head of the bed results in hemodynamic instability. We examined the effect of head of bed elevation (HBE) on hemodynamic status and investigated the factors that influence mean arterial pressure (MAP) and central venous oxygen saturation (ScvO2) when patients were positioned at 0°, 30°, and 45°. METHODS: Two hundred hemodynamically stable adults on invasive mechanical ventilation admitted to a multidisciplinary surgical intensive care unit were recruited. Patients' characteristics included catecholamine and sedative doses, the original angle of head of bed elevation (HBE), the level of positive end expiratory pressure (PEEP), duration and mode of mechanical ventilation. A sequence of HBE positions (0°, 30°, and 45°) was adopted in random order, and MAP and ScvO2 were measured at each position. Patients acted as their own controls. The influence of degree of HBE and of the covariables on MAP and ScvO2 was analyzed by using liner mixed models. Additionally, uni- and multivariable logistic regression models were used to indentify risk factors for hypotension during HBE, defined as MAP <65 mmHg. RESULTS: Changing HBE from supine to 45° caused significant reductions in MAP (from 83.8 mmHg to 71.1 mmHg, P < 0.001) and ScvO2 (76.1% to 74.3%, P < 0.001). Multivariable modeling revealed that mode and duration of mechanical ventilation, the norepinephrine dose, and HBE had statistically significant influences. Pressure-controlled ventilation was the most influential risk factor for hypotension when HBE was 45° (odds ratio (OR) 2.33, 95% confidence interval (CI), 1.23 to 4.76, P = 0.017). CONCLUSIONS: HBE to the 45° position is associated with significant decreases in MAP and ScvO2 in mechanically ventilated patients. Pressure-controlled ventilation, higher simplified acute physiology (SAPS II) score, sedation, high catecholamine, and PEEP requirements were identified as independent risk factors for hypotension after backrest elevation. Patients at risk may need positioning at 20° to 30° to overcome the negative effects of HBE, especially in the early phase of intensive care unit admission