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Biomedical subjects

M Czerny

Publications and source records attributed to M Czerny.

At least 37 records · Page 2Linked to original sources

Model studies on the influence of coffee melanoidins on flavor volatiles of coffee beverages.

Addition of the total melanoidin fraction isolated by water extraction from medium-roasted coffee powder to a model solution containing a set of 25 aroma compounds mimicking the aroma of a coffee brew reduced, in particular, the intensity of the roasty, sulfury aroma quality. Model studies performed by static headspace analysis revealed that especially three well-known coffee odorants, that is, 2-furfurylthiol (FFT), 3-methyl-2-butene-1-thiol, and 3-mercapto-3-methylbutyl formate, were significantly reduced in the headspace above an aqueous model solution when melanoidins were added. In particular, the low molecular weight melanoidins (1500-3000 Da) led to the most significant decrease in FFT. In contrast, for example, aldehydes remained unaffected by melanoidin addition.

Chromatography, Gas↗

First experiences with outpatient care of patients with implanted axial flow pumps.

As known from patients with pulsatile ventricular assist devices (VADs), early mobilization, physical exercise, and return to normal life are essential for optimal recovery. Recently, implantable rotary pumps became available for extended left ventricular support as bridges to transplantation. Modified procedures are essential for patient training and hospital discharge. The MicroMed-DeBakey VAD was implanted in 10 patients with end-stage heart disease. After recovery, regular ergometer training was performed with loads adapted to the patient's condition. Procedures for patient observation under outdoor conditions and a blood pressure measuring device for low pulse pressure conditions were developed. Improvement of physical condition was achieved in 8 patients. In the first 2 patients, exercise capacity was limited due to flow obstruction. In the following patients, an increase of workload on the ergometer up to 120 W was observed. Correlated with training, lactate/load relationship and heart rate decreased. Three patients were discharged from the hospital during support. The DeBakey-VAD system can support patients for extended time periods and is suitable for recovery and exercise. Under optimal patient and environmental conditions, discharge from the hospital can be obtained.

Adult↗

Mechanical trauma as the major cause of troponin T release after transvenous implantation of cardioverter/defibrillators.

To study the cause of myocardial injury after elective transvenous insertion of a cardioverter/defibrillator, we measured troponin T (TnT) release in 27 patients. Five patients needing only replacement of the generator with threshold testing served as controls. Compared to the control group, a significant increase in TnT occurred in the patients undergoing insertion, which was greatest in the group receiving screw-in electrodes. There was no correlation between TnT and the number and energy of the shocks and the time in fibrillation. Duration of surgery and TnT release were positively associated. Cardiac injury therefore mainly results from mechanical trauma during insertion of the electrodes and only to a lesser degree from electrical and ischemic lesions.

Biomarkers↗

Improved long-term results with thymoglobuline induction therapy after cardiac transplantation: a comparison of two different rabbit-antithymocyte globulines.

BACKGROUND: The aim of this retrospective single center analysis was to compare possible long-term benefits of two different rabbit-antithymocyte globuline (ATG) induction therapies after cardiac transplantation. PATIENTS AND METHODS: A total of 484 primary cardiac transplanted patients received induction therapy with two different rabbit-ATGs (thymoglobuline: n=342, ATG-fresenius: n=142). All patients received immunosuppressive maintenance therapy with cyclosporine, azathioprine, and prednisolone. Cardiac rejection was assessed by serial endomyocardial biopsies. Surveillance of graft arteriosclerosis was performed by angiograms 1, 3, and 5 years after transplantation. RESULTS: Five-year survival was significantly better in the thymoglobuline group (76 vs. 60%). Thymoglobuline patients had a lower rate of death from rejection (2.3 vs. 10%; P<0.01) and graft arteriosclerosis (0.88 vs. 5.6%; P<0.01). After 5 years, freedom from rejection was 72% in the thymoglobuline group compared to 42% in the ATG-fresenius group (P<0.01). Graft arteriosclerosis appeared in 14% of thymoglobuline patients and in 28% of ATG-fresenius patients (P<0.01). Viral infections occurred more often in thymoglobuline patients (53 vs. 39%, P<0.05) although there was no difference in appearance of cytomegalovirus disease (17 vs. 13%). Freedom from posttransplant malignant disease was comparable between the two groups. CONCLUSION: These results suggest that there are differences between rabbit ATG products. The superior prevention of rejection with thymoglobuline may be the reason for the lower rate of graft arteriosclerosis.

Adolescent↗

Prostaglandin E(1) does not influence plasmatic coagulation, hepatic synthesis, or postoperative blood loss in patients after coronary-artery bypass grafting.

STUDY OBJECTIVE: To assess whether postoperatively administered prostaglandin E1 (PGE1) might prevent bleeding in patients after coronary artery bypass grafting (CABG). DESIGN: Prospective, randomized, placebo-controlled trial. SETTING: University-affiliated hospital. PATIENTS: 49 patients scheduled for elective CABG surgery. INTERVENTIONS: The PGE1 group received intravenous PGE(1) up to 15 ng/kg/min for 72 hours after surgery, whereas the placebo group received isotonic saline for the same time period. MEASUREMENTS AND MAIN RESULTS: Nine patients (4 in the PGE1 group vs. 5 in the placebo group) had to be excluded because of hemodynamic instability, and 1 in the placebo group because of gastric bleeding. In the remaining 39 patients (20 vs. 19), no significant differences with regard to hemoglobin levels or platelet count could be observed. There was no significant difference between the groups concerning the amount of packed red blood cells, platelet concentrates, or fresh frozen plasma transfused. No significant differences could be observed regarding laboratory markers of coagulation activation or hepatic synthesis either. CONCLUSIONS: PGE1 did not prevent coagulation disturbances and blood loss when administered postoperatively in patients undergoing CABG. The absence of these expected effects might be explained by the concomitant administration of acetylsalicylic acid, whose antiaggregatory acivity seems to exceed the effects of PGE1.

Aged↗

Inflammatory response and myocardial injury following coronary artery bypass grafting with or without cardiopulmonary bypass.

OBJECTIVE: In coronary artery bypass grafting (CABG) without cardiopulmonary bypass (CPB) the inflammatory response is suggested to be minimized. Coronary anastomoses are performed during temporary coronary occlusion. Inflammatory response and myocardial ischaemia need to be studied in a randomized study comparing CABG in multivessel disease with versus without CPB. METHODS: Following randomization 30 consecutive patients received CABG either with (n=16) or without CPB (n=14). Primary study endpoints were parameters of the inflammatory response (interleukin (IL)-6, interleukin-10, ICAM-1, P-selectin) and of myocardial injury (myoglobin, creatine kinase-MB (CK-MB), troponin I) (intraoperatively, 4, 8, 16, 24 and 48 h after surgery). The secondary endpoint was clinical outcome. RESULTS: The incidence of major (death: CABG with CPB n=1, not significant (n.s.)) and minor adverse events (wound infection: with CPB n=2, without CPB n=1, n.s. ; atrial fibrillation: with CPB n=3, without CPB n=2, n.s.) was comparable between both groups. The release of IL-6 was comparable during 8 h of observation (n.s.). Immediately postoperatively IL-10 levels were higher in the operated group with CPB (211.7+/-181.9 ng/ml) than in operated patients without CPB (104.6+/-40.3 ng/ml, P=0.0017). Thereafter no differences were found between both groups. A similar pattern of release was observed in serial measures of ICAM-1 and P-selectin, with no difference between both study groups (n.s.). Eight hours postoperatively the cumulative release of myoglobin was lower in operated patients without CPB (1829.7+/-1374. 5 microg/l) than in operated patients with CPB (4469.8+/-4525.7 microg/l, P=0.0152). Troponin I release was 300.7+/-470.5 microg/l (48 h postoperatively) in patients without CPB and 552.9+/-527.8 microg/l (P=0.0213). CK-MB mass release was 323.5+/-221.2 microg/l (24 h postoperatively) in operated patients without CPB and 1030. 4+/-1410.3 microg/l in operated patients with CPB (P=0.0003). CONCLUSIONS: This prospective randomized study suggests that in low-risk patients the impact of surgical access on inflammatory response may mimic the influence of long cross-clamp and perfusion times on inflammatory response. Our findings indicate that multiregional warm ischaemia, caused by snaring of the diseased coronary artery, causes considerably less myocardial injury than global cold ischaemia induced by cardioplegic cardiac arrest.

Adult↗

Normothermic cardiopulmonary bypass is beneficial for cognitive brain function after coronary artery bypass grafting--a prospective randomized trial.

BACKGROUND: Hypothermic and normothermic cardiopulmonary bypass (CPB) have resulted in apparently contradictionary cardiac and neurologic outcome. Cerebrovascular risk and cognitive dysfunction associated with normothermic CPB still remain uncertain. MATERIALS AND METHODS: In a prospective randomized study, we measured the effects of mildly hypothermic (32 degrees C, n=72) vs. normothermic (37 degrees C, n=72) CPB on cognitive brain function. All patients received elective coronary artery bypass grafting (mean age 62.1+/-6.3 years, mean ejection fraction 60.4+/-13%). Cognitive brain function was objectively measured by cognitive P300 auditory-evoked potentials before surgery, 1 week and 4 months after surgery, respectively. Additionally, standard psychometric tests ('trailmaking test A', 'mini-mental state') were performed and clinical outcome was monitored. RESULTS: Patients, operated with mild hypothermia, showed a marked impairment of cognitive brain function. As compared with before surgery (370+/-45 ms), P300 evoked potentials were prolonged at 1 week (385+/-37 ms; P<0.001) and even at 4 months (378+/-34 ms, P<0.001) after surgery, respectively. In contrast, patients operated with normothermic CPB, did not show an impairment of P300 peak latencies (before surgery 369+/-36 ms, 1 week after surgery 376+/-38 ms, n.s.; 4 months after surgery 371+/-32 ms, n.s.). Group comparison revealed a trend towards prolonged P300 peak latencies in the patient group undergoing mildly hypothermic CPB (P=0.0634) 1 week after surgery. Four months postoperatively, no difference between the two groups could be shown (P=n.s.) Trailmaking test A and mini mental state test failed to discriminate any difference. Five patients died (mild hypothermia n=3, normothermia n=2) postoperatively (cardiac related n=3, sepsis n=2). None of the patients experienced major adverse cerebrovascular events. CONCLUSIONS: Objective cognitive P300 auditory evoked potential measurements indicate, that subclinical impairment of cognitive brain function is more pronounced in patients undergoing mildly hypothermic CPB as compared with normothermic CPB for CABG.

Brain↗

Potent odorants of raw Arabica coffee. Their changes during roasting.

Aroma extract dilution analysis of raw Arabica coffee revealed 3-isobutyl-2-methoxypyrazine (I), 2-methoxy-3,5-dimethylpyrazine (II), ethyl 2-methylbutyrate (III), ethyl 3-methylbutyrate (IV), and 3-isopropyl-2-methoxypyrazine (V) as potent odorants. The highest odor activity value was found for I followed by II, IV, and V. It was concluded that I was responsible for the characteristic, peasy odor note of raw coffee. Twelve odorants occurring in raw coffee and (E)-beta-damascenone were also quantified after roasting. The concentration of I did not change, whereas methional, 3-hydroxy-4, 5-dimethyl-2(5H)-furanone, vanillin, (E)-beta-damascenone, and 4-vinyl- and 4-ethylguaiacol increased strongly during the roasting process.

Chromatography, Gas↗

Comparing Doppler ultrasonography and cerebral oximetry as indicators for shunting in carotid endarterectomy.

To determine the thresholds of selective shunting in carotid endarterectomy during general anesthesia, we compared transcranial Doppler ultrasonography and cerebral oximetry (RSO2). During carotid cross-clamping, RSO2 and mean blood flow velocity in the middle cerebral artery (Vm,mca) was simultaneously monitored in 55 of 59 patients. A relative decrease in Vm,mca to <20% of preclamp velocity was the indication for selective shunting. Three patients were shunted, two because of criteria of Vm,mca and one in which Vm,mca measurements were impossible. No postoperative neurological deficits occurred. During cross-clamping, both Vm,mca (42+/-16 vs. 26+/-12 cm/s; P<0.001) and RSO2 (68+/-7% vs. 62+/-8%; P<0.01) decreased and a significant correlation between %Vm,mca and DeltaRSO2 was found (R(2) = 0.40; P = 0.003). Decreases in RSO2 >13% identified two patients later shunted; however, this threshold would have indicated unnecessary shunting in seven patients (false positives = 17%). Transcranial Doppler ultrasonography identified patients at risk for ischemia more accurately than RSO2. Relying on RSO2 alone would increase the number of unnecessary shunts because of the low specificity. Accepting higher decreases in RSO2 does not appear reasonable because it bears the risk of a low sensitivity.

Adult↗

Collagen patch coated with fibrin glue components. Treatment of suture hole bleedings in vascular reconstruction.

BACKGROUND: Bleeding from suture holes during vascular reconstruction, particularly when polytetrafluoroethylene (PTFE) prostheses are used, is still a problem which can lead to intraoperative delay and increased blood loss. The aim of this prospective, randomised, open, controlled multicentre study was to evaluate whether the use of a new local haemostyptic would reduce intraoperative blood loss and the time to haemostasis. METHODS: Thirty patients received a new haemostyptic (TachoComb H, Nycomed Pharma AG), whereas another 30 patients were treated with compresses. The vascular reconstructions were either anastomoses or patch angioplasties and were performed using PTFE vascular prostheses. RESULTS: The mean time to haemostasis of suture hole bleeding in the haemostyptic group (326.0 sec) was significantly shorter compared to the control group (514.3 sec) (p=0.006). The median intraoperative blood loss was 24.5 g in the treatment group and 57.3 g in the control group (p=0.045). CONCLUSIONS: It was shown that collagen patches coated with components of fibrin glue significantly reduce the time to haemostasis as well as blood loss at the operation site in patients undergoing vascular reconstruction with PTFE grafts.

Aged↗

Sensory study on the character impact odorants of roasted arabica coffee.

The potent odorants were quantified in a sample of roasted Arabica coffee. On the basis of the results, 27 odorants were dissolved in an oil/water mixture. The flavor profile of the model obtained was very close to that of the real sample. In duo and triangle tests, the model was compared with models missing one or more odorants. These experiments indicated that 2-furfurylthiol, 4-vinylguaiacol, several alkyl pyrazines, furanones, acetaldehyde, propanal, methylpropanal, and 2- and 3-methylbutanal had the greatest impact on the coffee flavor.

Adult↗

Surgical aspects of pediatric cardiac extracorporeal membrane oxygenation.

Because children with severe myocardial dysfunction have limited therapeutic options, mechanical support of a failing heart is a matter of great interest. In the setting of cardiogenic shock or severe low cardiac output and hypoperfusion, extracorporeal membrane oxygenation (ECMO) can produce decisive improvements. The criteria for successful treatment include appropriate patient selection, improved surgical techniques and experience, higher recognition and anticipation of complications, and minimized delay in initiation of ECMO. Because the need for mechanical circulatory support may arise pre-, intra-, and postoperatively, every pediatric cardiac surgeon must be familiar with the principles and the surgical aspects of ECMO.

Cardiac Output, Low↗