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Search Results: 1 - 10 of 542126 matches for " M-C Seghaye "
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High oxygen treatment during preparation of children for open-heart surgery leads to a decrease in total antioxidant capacity
CTA Evelo, SLM Coort, NJG Jansen, JF Vazquez-Jimenez, M-C Seghaye
Critical Care , 2001, DOI: 10.1186/cc1008
Abstract: Total trolox equivalents in antioxidant capacity (TEAC) were calculated from the reactivity toward the artificially generated 2,2'-azinobis-(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) radical. To exclude the possibility that TEAC values decrease as a result of haemodilution, we measured the triglyc-eride content using the GPO-trinder (Sigma) reagent in a microtitre-plate spectrophotometric analysis.Total antioxidant capacity was decreased shortly after the onset of surgery in plasma of children (aged 8-14 months) treated for ventricular septal defect (VSD; n = 17) and tetralogy of Fallot (TOF; n = 15). Figure 1 shows a significant (Friedman test; P < 0.05) decrease in both VSD and TOF from time point 1.1 (induction of anaesthesia) to time point 2 (heparin administration before CPB). Decrease in TEAC values can therefore not be a result of haemodilution during CPB. This was confirmed by the fact that total plasma triglyceride values did not decrease between these time points. Shortly after CPB (time point 4) the TEAC values were already significantly (P < 0.05) higher than at time point 3 (10 min after the onset of CPB), and they returned to normal during the 4 h after the operation and remained normal thereafter.We showed a decrease in antioxidant capacity early during the operation, which could not have been caused by haemodilution. The most likely cause appears to be the high oxygen that was given during preparation for CPB. The methodology described here will be useful for study of the influences of different approaches in, for example, oxygen treatment, clamping techniques, temperature treatment and antioxidant supply on the oxidative stress that occurs during open-heart surgery.
Cerebral cytokine expression after cardiac surgery with cardiopulmonary bypass
Ma Qing, M Sokalska, B Voss, T Richter, J Schlegel, J Hess, R Lange, M-C Seghaye
Critical Care , 2003, DOI: 10.1186/cc2155
Abstract: Fourteen young pigs were operated on with standardized CPB in either normothermia (n = 7) or moderate hypothermia (n = 7). Six hours after termination of CPB, forehead brain tissue was taken for detection of gene expression and synthesis of tumor necrosis factor (TNF)-α, IL-1β, IL-6, IL-10 and inducible nitric oxide synthase (iNOS) by competitive reverse transcription polymerase chain reaction and/or Western blot. Phosphorylation level of the inhibitory protein of nuclear factor-κB (IκB-α) was also measured by Western blot. Additional probes of hippocampus, cortex and middle brain were taken for standard histology.mRNA and protein levels of TNF-α, IL-1β and IL-6, as well as phosphorylated IκB-α, were detected in all animals, and iNOS in 10/14 animals. The anti-inflammatory cytokine IL-10 was not expressed in any of the animals. Histological alterations including mild edema and a few trapped lymphocytes were found in the different areas investigated. Results were not affected by temperature management during CPB.In our model, cardiac surgery is related to upregulation of proinflammatory cytokines and iNOS in the brain. This synthesis involves the activation of the nuclear factor-κB pathway. In contrast to our previous observations in other organs, there is no anti-inflammatory reaction in the brain 6 hours after CPB. Proinflammatory cytokines could contribute toward damaging brain cells after cardiac surgery.
Relationship between cardiac troponin I (cTnI) release during cardiac operations and myocardial cell death
JF Vazquez-Jimenez, Ma Qing, B Klosterhalfen, O Liakopoulos, G von Bernuth, BJ Messmer, M-C Seghaye
Critical Care , 2000, DOI: 10.1186/cc722
Abstract: Eighteen young pigs were operated on with standardized cardiopulmonary bypass (CPB). Release of cTnI in the cardiac lymph (CL), coronary sinus (CS), and arterial blood (A) was related to postoperative myocardial cell death by both necrosis and apoptosis. Apoptotic cells were detected by a TUNEL detection kit. Necrotic cells were counted by light microscopy.In all animals, cTnI was significantly released and reached peak values observed simultaneously in A (cTnI, 20.1 ± 2.6 ng/ml) (mean ± SEM), CS (19.5 ± 3.2 ng/ml) and CL (5202 ± 2500 ng/ml). Percentage of total myocardial cell death was 3.1 ± 0.5%, including 1.2 ± 0.35% necrosis and 1.9 ± 0.5% apoptosis. cTnI release during and after CPB did not correlate with the degree of myocardial apoptosis or necrosis.Cardiac operations with CPB are related to myocardial cell damage including myocardial cell death due to both necrosis and apoptosis. As the loss of cTnI is not related to the amount of cell death, our results suggest that increased cardiac myocyte membrane permeability more than cell death is responsible for intraoperative and postoperative cTnI release.
Effect of temperature on leukocyte activation during cardiopulmonary bypass (CPB) and postoperative organ damage
M Qing, M-C Seghaye, JF Vazquez-Jimenez, RG Grabitz, B Klosterhalfen, M Sigler, BJ Messmer, G von Bernuth
Critical Care , 1999, DOI: 10.1186/cc331
Abstract: 18 young pigs were randomly assigned to a T°- group during CPB: normothermia (T° 37°C; n = 6), mild hypothermia (T° 28°C; n = 6) and deep hypothermia (T° 20°C; n = 6). Leukocyte count and plasma levels of tumor necrosis factor (TNFα) were measured before, during and after CPB. At the end of the experimentation (6 h post-CPB), probes of heart, lungs, liver, kidney, and intestine were taken for histological examination.There was a significant fall of leukocyte count at induction of CPB, without any intergroup difference. During and at the end of CPB, leukocyte count was significantly higher in group 37°C as compared with the other groups. At a later stage after CPB, group 20°C showed significantly higher leukocyte count than group 28°C and group 37°C, respectively. The course of neutrophils was similar.TNF-α was not released in group 28°C neither during nor after CPB. By contrast, there was a significant production of TNF-α in groups 37°C and 20°C, the circulating levels being significantly higher in group 37°C. Histological examination showed that the most important tissue damage in terms of interstitial edema and leukostasis in heart, lung, liver, kidney, and small intestine was seen in group 37°C followed by group 20°C while the least important damage was present in group 28°C.CPB-induced postoperative organ damage, probably related to leukocyte activation and TNF-α production, is highest in pigs operated on in normothermia and lowest in those operated on in mild hypothermia.
Influences of pre-, peri- and postoperative risk factors in neonatal cardiac surgery on neurodevelopmental status in preschool-age children
HH H?vels-Gürich, M-C Seghaye, M Sigler, A Bartl, F Kotlarek, J Neuser, BJ Messmer, G von Bernuth
Critical Care , 2000, DOI: 10.1186/cc676
Abstract: Thirty-three unselected children operated on as neonates with combined deep hypothermic circulatory arrest and low flow cardiopulmonary bypass were examined at an age of 3.0–4.6 years [3.6 ± 0.5 (mean ± standard deviation)]. The control group for developmental outcome consisted of 32 age-matched healthy children, who were 3.0–4.8 years [3.8 ± 0.6 (mean ± standard deviation)] of age. Evaluation of socioeconomic status and a standardised test comprising all areas of child development (Vienna developmental test), including scores of motor and cognitive functions, perception, language, learning and behaviour, were carried out in patients and controls, and clinical neurological status was assessed in patients. Results of patients were related to those of the control group and to pre-, peri-, and postoperative cerebral risk factors of the control group and to pre-, peri-, and postoperative cerebral risk factors as described in the context.Neurological impairment was more frequent (6.1%) than in the normal population. Compared with published norms, complete developmental score and the subtests for motor function, visual perception and visual motor integration, learning and memory, cognitive function, language, and socioemotional functions were not different. Compared with the control group, complete developmental score, cognitive score and language were reduced (P < 0.01), but socioeconomic status was significantly lower in the patient group (P = 0.0001). Motor function was weakly, but significantly inversely related to the duration of circulatory arrest (Pearson correlation coefficient -0.37; P = 0.049), but not to the duration of bypass. The other developmental parameters were not related to the duration of the support techniques. Serum levels of the biochemical marker neuron-specific enolase, although significantly elevated at the end of bypass (P = 0.0002) and 4 h after surgery (P = 0.0012) compared with preoperative values, were not correlated to developmental test re
The effect of temperature during extracorporeal circulation on ultrastructure of cardiomyocytes
R Chakupurakal, B Hermanns, JF Vazquez-Jiminez, Ma Qing, S Lücking, BJ Messmer, G von Bernuth, M-C Seghaye
Critical Care , 2001, DOI: 10.1186/cc1001
Abstract: Fifteen pigs were randomly assigned to one of three temperature groups (37, 28 and 20°C) during ECC (n = 5 each). ECC time was 120 min and myocardial ischaemia time was 60 min. Cardioplegia was achieved by injecting a crystalloid solution (4°C cold Bretschneider solution, 30 ml/kg) into the aortic root. Flow index was set at 2.7 l/m2 per min. Six hours after ECC, myocardial samples were taken from the left ventricle for ultrastructural examination by electron microscopy.All animals showed intact contractile apparatus, with normal texture of the myofibrils and normal configuration of the Z-bands. Quantitative and structural changes of mitochondria were frequent. Animals from the 37°C group showed marked interstitial oedema and dehiscence of the cytoplasmatic membrane with ruptures, whereas lesser damage to the membrane was observed in the other two groups. The 28°C group showed the least pronounced ultrastructural changes.These results show that cardiac operations with ECC are associated with ultrastructural lesions of the cardiomyocytes. In this experimental setup, these lesions were most pronounced under normothermic and least pronounced under moderate hypothermic ECC.
Myocardial cell damage related to arterial switch operation in neonates with transposition of the great arteries
HH H?vels-Gürich, JF Vazquez-Jimenez, A Silvestri, K Schumacher, S Kreitz, J Duchateau, BJ Messmer, G von Bernuth, M-C Seghaye
Critical Care , 2001, DOI: 10.1186/cc1009
Abstract: Sixty-three neonates (age 2-28 [8.1 ± 4.6] days), who were operated on under combined deep hypothermic (15°C) circulatory arrest and low-flow cardiopulmonary bypass (CPB), were studied. Inclusion criteria were transposition of the great arteries with or without ventricular septal defect (VSD) that was suitable for arterial switch operation (VSD-; n = 53), and if necessary additional VSD closure (VSD+; n = 10). Patients were differentiated clinically into two groups by presence or absence of MD within 24 h after surgery. MD was defined as myocardial ischaemia after coronary reperfusion and/or myocardial hypocontractility as assessed by echocardiography. MD was related to clinical outcome parameters and to perioperative release of cardiac troponin-T (cTnT) and production of interleukin-6 and interleukin-8.MD was observed in 11 patients (17.5%). Two patients died early after surgery from myocardial infarction, and two died late after surgery (6.3%). CPB and cross-clamping, but not deep hypothermic circulatory arrest times, were correlated with MD; MD was more frequent in the VSD+ than in the VSD- group because of longer support times. Coronary status and age at surgery were not related to MD. Patients with MD had more frequently impaired cardiac, respiratory and renal functions. cTnT, interleukin-6 and interleukin-8 were significantly elevated at the end of CPB, and 4 and 24 h after surgery, as compared with preoperative values in both groups. Postoperative cTnT, interleukin-6 and interleukin-8 concentrations were significantly higher in MD patients than in the others. Multivariable analysis of independent risk factors for MD revealed interleukin-6 4 h after surgery to be significant (P = 0.04; odds ratio 1.24 [95% confidence interval 1.01-1.52] per 10 pg/ml). The cutoff point for prediction of MD was set at 500 pg/ml (specificity 95.4%, sensitivity 72.7%).Cardiac operations in neonates induce the production of the proinflammatory cytokines interelukin-6 and interleuki
Genomic analysis of human breast cancer in families and populations
M-C King
Breast Cancer Research , 2005, DOI: 10.1186/bcr1046
Ultrastructural features of the uterus in the sexually immature ostrich (Struthio camelus) during periods of ovarian inactivity and activity
M-C. Madekurozwa
Onderstepoort Journal of Veterinary Research , 2010, DOI: 10.4102/ojvr.v74i3.123
Abstract: The ultrastructure of the surface epithelium and tubular glands of the uterus in the immature ostrich is described. In ostriches with inactive ovaries the uterus is lined by a non-ciliated simple columnar epithelium, with basally located heterochromatic nuclei. Scanning electron microscopy revealed that these non-ciliated cells have a dense microvillous cover. A simple columnar to pseudostratified columnar epithelium, comprised of non-ciliated and ciliated cells, lines the uterus in birds with active ovaries. The ciliated cells possess a wide luminal region, which contains a nucleus and various organelles. An accumulation of secretory granules was observed in the apical regions of the non-ciliated cells, as well as in a few ciliated cells. In addition to non-ciliated and ciliated cells, a cell type with rarefied cytoplasm was also identified. These cells appear to correspond to calcium secreting cells identified in other avian species. The results of this study indicate that, although uterine differentiation is present in immature ostriches with active ovaries, the production of secretory product appears to occur mainly in non-ciliated epithelial cells.
Immunoreactivities to protein gene product 9.5, neurofilament protein and neuron specific enolase in nerves in the oviduct of the sexually immature ostrich, Struthio camelus
M-C. Madekurozwa
Onderstepoort Journal of Veterinary Research , 2010, DOI: 10.4102/ojvr.v73i2.158
Abstract: The present study investigated the distribution of nerves in the oviduct of the sexually immature ostrich. The presence of protein gene product 9.5, neurofilament protein and neuron specific enolase nerve fibres were demonstrated in the infundibulum, magnum, isthmus, shell gland and vagina. Nerve fibres containing protein gene product 9.5, neuron specific enolase and neurofilament protein were particularly numerous in the tunica muscularis and intermuscular connective tissue areas of the shell gland and vagina. The presence of a large number of nerves in these oviductal regions is probably important in the coordination of muscle contraction. An interesting finding of the study was the presence of protein gene product 9.5 and neuron specific enolase immunopositive nerve fibres in the walls of blood vessels. It is likely that these nerves are autonomicin nature and play a role in the regulation of blood flow. This study has shown the presence of an extensive neural network in the oviduct of the ostrich. In addition, the results of the investigation have shown that the neuronal markers protein gene product 9.5, neurofilament protein and neuron specific enolase can be used to demonstate nerve fibres in the ostrich.
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