Viktor Hegedüs

Posztkondicionálás kísérletes alkalmazása aortakirekesztés kapcsánr

BACKGROUND Postconditioning - using alternating brief cycles of reperfusion/reocclusion applied just at the very beginning of reperfusion - has recently been described as a potent therapeutic technique, attenuating ischaemia-reperfusion injury. In vascular surgery, certain elective interventions involve cross-clamping of major arteries, resulting in temporary ischaemia in large peripheral organs, which thus suffer ischaemia-reperfusion injury. Patients undergoing these operations may develop also serious systemic complications such as multiple distant organ dysfunctions, SIRS, detrimental redistribution of the circulation or even shock, a phenomenon called reperfusion-syndrome. We studied the effects of postconditioning on reperfusion-syndrome in a rodent experimental model. MATERIAL AND METHODS Anaesthetized male Wistar rats underwent 180 minutes of bilateral lower limb ischaemia and 4 hours of reperfusion using an infrarenal cross-clamping of the abdominal aorta. Control animals underwent no additional intervention. Postconditioning consisted of 6 cycles of 10-second aortic occlusion/10-second declamping starting at the beginning of reperfusion. Haemodynamic parameters were observed with invasive arterial manometer, microcirculation of the lower limb was detected with laser-Doppler-flowmeter. After 4 hours of reperfusion serum, urine, and histological samples were collected. RESULTS 180-minute ischaemia resulted in significant haemodynamic changes after reperfusion. Postconditioning affected the character of the microcirculatory flow curves, the limb circulation stabilized with hyperaemia after reperfusion. Postconditioning caused a significant reduction in systemic inflammatory response (TNF-alpha, oxygen-derived free radicals). The laboratory and histological samples implied a significant decrease in remote organ (lung and renal) dysfunctions after postconditioning. CONCLUSION Postconditioning proves to be capable in conferring protection against different organ injuries caused by longer circulatory occlusions during elective major vascular surgeries.

Levosimendan: a cardiovascular drug to prevent liver ischemia-reperfusion injury?

Introduction Temporary occlusion of the hepatoduodenal ligament leads to an ischemic-reperfusion (IR) injury in the liver. Levosimendan is a new positive inotropic drug, which induces preconditioning-like adaptive mechanisms due to opening of mitochondrial KATP channels. The aim of this study was to examine possible protective effects of levosimendan in a rat model of hepatic IR injury. Material and Methods Levosimendan was administered to male Wistar rats 1 hour (early pretreatment) or 24 hours (late pretreatment) before induction of 60-minute segmental liver ischemia. Microcirculation of the liver was monitored by laser Doppler flowmeter. After 24 hours of reperfusion, liver and blood samples were taken for histology, immuno- and enzyme-histochemistry (TUNEL; PARP; NADH-TR) as well as for laboratory tests. Furthermore, liver antioxidant status was assessed and HSP72 expression was measured. Results In both groups pretreated with levosimendan, significantly better hepatic microcirculation was observed compared to respective IR control groups. Similarly, histological damage was also reduced after levosimendan administration. This observation was supported by significantly lower activities of serum ALT (pearly = 0.02; plate = 0.005), AST (pearly = 0.02; plate = 0.004) and less DNA damage by TUNEL test (pearly = 0.05; plate = 0.034) and PAR positivity (pearly = 0.02; plate = 0.04). Levosimendan pretreatment resulted in significant improvement of liver redox homeostasis. Further, significantly better mitochondrial function was detected in animals receiving late pretreatment. Finally, HSP72 expression was increased by IR injury, but it was not affected by levosimendan pretreatment. Conclusion Levosimendan pretreatment can be hepatoprotective and it could be useful before extensive liver resection.

Posztkondicionálás kísérletes alkalmazása aortakirekesztés kapcsán Effect of postconditioning in major vascular operations on rats

BACKGROUND Postconditioning - using alternating brief cycles of reperfusion/reocclusion applied just at the very beginning of reperfusion - has recently been described as a potent therapeutic technique, attenuating ischaemia-reperfusion injury. In vascular surgery, certain elective interventions involve cross-clamping of major arteries, resulting in temporary ischaemia in large peripheral organs, which thus suffer ischaemia-reperfusion injury. Patients undergoing these operations may develop also serious systemic complications such as multiple distant organ dysfunctions, SIRS, detrimental redistribution of the circulation or even shock, a phenomenon called reperfusion-syndrome. We studied the effects of postconditioning on reperfusion-syndrome in a rodent experimental model. MATERIAL AND METHODS Anaesthetized male Wistar rats underwent 180 minutes of bilateral lower limb ischaemia and 4 hours of reperfusion using an infrarenal cross-clamping of the abdominal aorta. Control animals underwent no additional intervention. Postconditioning consisted of 6 cycles of 10-second aortic occlusion/10-second declamping starting at the beginning of reperfusion. Haemodynamic parameters were observed with invasive arterial manometer, microcirculation of the lower limb was detected with laser-Doppler-flowmeter. After 4 hours of reperfusion serum, urine, and histological samples were collected. RESULTS 180-minute ischaemia resulted in significant haemodynamic changes after reperfusion. Postconditioning affected the character of the microcirculatory flow curves, the limb circulation stabilized with hyperaemia after reperfusion. Postconditioning caused a significant reduction in systemic inflammatory response (TNF-alpha, oxygen-derived free radicals). The laboratory and histological samples implied a significant decrease in remote organ (lung and renal) dysfunctions after postconditioning. CONCLUSION Postconditioning proves to be capable in conferring protection against different organ injuries caused by longer circulatory occlusions during elective major vascular surgeries.

[Remote ischemic conditioning: short-term effects on rat liver ischemic-reperfusion injury].

INTRODUCTION Several techniques have been developed to reduce ischemic-reperfusion injury. A novel method is the remote ischemic perconditioning, applied parallel with target organ ischemia. AIM The aim of the study was to determine the extent of liver ischemic-reperfusion injury via the application of this novel method. METHODS Male Wistar rats (n = 30, 10/group) were subjected to 60-minute partial liver ischemia and 60-minute reperfusion. Rats in the perconditioned group received conditioning treatment during the last 40 minutes of liver ischemia by infrarenal aortic clamping. Hepatic and lower limb microcirculation was monitored by laser Doppler flowmeter during reperfusion. After reperfusion, liver samples were taken for routine histological examination and redox-state assessment. Serum transaminase activities and liver tissue heat-shock protein-72 expression were measured. RESULTS Parameters of microcirculation showed significant (p<0.05) improvement in the perconditioned group in comparison with the control. Besides the significant improvement observed in the serum alanine amino-transferase activities, significantly milder tissue injury was detected histologically in the liver sections of the perconditioned group. Moreover, significant improvement was found in the redox-state parameters. CONCLUSION Perconditioning may be a reasonable possibility to reduce liver ischemic-reperfusion injury.

Postconditioning attenuates remote organ injury after lower limb arterial occlusion

Abstract Introduction External aortic compression due to acute gastric dilation is a rare etiology of the lower limb ischemia. This phenomenon leads the author to design experimental study for reperfusion syndrome. The lower limb ischemia-reperfusion (IR) injury consists of local and systemic components called the reperfusion syndrome. It can progrediate into a multi-organ failure which defines postoperative survival. A postconditioning is a surgical technique, which has a potential to reduce IR injury, therefore to prohibit the development of reperfusion syndrome. Aim XXXto examine on an experimental model, whether postonditioning is a practicable technique in infarenal aortic surgeries. Materials and Methods Male Wistar rats underwent 180 minutes of infrarenal aortic occlusion with 4, 24 and 72 hours of reperfusion. Postconditioning (10 sec. reocclusion / 10 sec. perfusion in 6 cycles) was applied in one group of each reperfusion time. Blood, urine, and histological (muscle, lung, kidney and liver) samp...

Alimentary induced fatty liver and adjuvant therapy with effective natural bioactive molecules

A redox-homeosztazis valtozasa a citokinek es szabad gyokok valtozasaval jar es szamos intracellularis jelatviteli utat befolyasolhat kulonboző majbetegsegekben. A liofilizalt cekla+repa keszitmeny (GPS Powder Kft. 1361/004/ 2003BFAEEA) bioaktiv komponensei, mint peldaul a betain, betaninok, betaxantinok, flavonoidok, polifenolok, glutamin, β-karotin, vitaminok es folsav megvaltoztathatjak a kulonboző sejtfolyamatokat. Celok: A szerzők celul tűztek ki a cekla+repa liofilizalt keszitmeny bioaktiv hatoanyagai vedőhatasanak vizsgalatat experimentalis zsirmajban. Modszer: Him Wistar patkanyokat etettek standard es zsirdus tappal (a standard tapot kiegeszitettek 2% koleszterinnel, 0,5% kolsavval es 20% napraforgoolajjal) es a kezelt csoportoknak az etetessel egyutt 0,1 vagy 1 g/ttkg/nap termeszetes keszitmenyt adagoltak. Az indukalhato ciklooxigenaz-2 enzim, az indukalt nitrogen-monoxid-szintetaz es a tumornekrozis-faktor-α mRNS-szinteket molekularis-biologiai modszerekkel hataroztak meg. A szabad gyokoket, a ...

Alimentáris eredetu kísérletes zsírmáj és adjuváns kezelése természetes eredetu bioaktív hatóanyagokkal

A redox-homeosztazis valtozasa a citokinek es szabad gyokok valtozasaval jar es szamos intracellularis jelatviteli utat befolyasolhat kulonboző majbetegsegekben. A liofilizalt cekla+repa keszitmeny (GPS Powder Kft. 1361/004/ 2003BFAEEA) bioaktiv komponensei, mint peldaul a betain, betaninok, betaxantinok, flavonoidok, polifenolok, glutamin, β-karotin, vitaminok es folsav megvaltoztathatjak a kulonboző sejtfolyamatokat. Celok: A szerzők celul tűztek ki a cekla+repa liofilizalt keszitmeny bioaktiv hatoanyagai vedőhatasanak vizsgalatat experimentalis zsirmajban. Modszer: Him Wistar patkanyokat etettek standard es zsirdus tappal (a standard tapot kiegeszitettek 2% koleszterinnel, 0,5% kolsavval es 20% napraforgoolajjal) es a kezelt csoportoknak az etetessel egyutt 0,1 vagy 1 g/ttkg/nap termeszetes keszitmenyt adagoltak. Az indukalhato ciklooxigenaz-2 enzim, az indukalt nitrogen-monoxid-szintetaz es a tumornekrozis-faktor-α mRNS-szinteket molekularis-biologiai modszerekkel hataroztak meg. A szabad gyokoket, a ...