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Biomedical subjects

D Schranz

Publications and source records attributed to D Schranz.

At least 19 recordsLinked to original sources

Transcatheter radiofrequency perforation and stent implantation for palliation of pulmonary atresia in a 3060-g infant.

In a 3060-g infant with fibromuscular pulmonary atresia an open right ventricular outflow tract was created by means of interventional cardiological methods. Following two inadvertent perforations without sequelae or clinical symptoms, radiofrequency perforation and subsequent balloon dilatation were successfully performed. The implantation of a Palmaz iliac stent led to a predictable communication between the right ventricle and pulmonary artery.

Cardiac Catheterization

Evaluation of the pulse wave arrival time as a marker for blood pressure changes in critically ill infants and children.

OBJECTIVE: Pulse arrival time (PAT), which is the interval between the R wave of the electrocardiogram (ECG) and the arrival of the pulse wave peripherally, has been reported to be suitable for use as an indirect measure of blood pressure change. The purpose of this study was to evaluate, in critically ill infants and children, the degree to which 1/PAT covaries with systolic, diastolic, and mean blood pressure, as well as heart rate. METHODS: A laboratory device was used to calculate PAT in real time from the ECG and the plethysmographic curve of pulse oximetry used for routine monitoring. Calculated PAT and corresponding blood pressures and heart rate were stored on hard disk. A total of 15 critically ill patients, aged 6 days to 16 years, weighing 3 to 80 kg, were studied. RESULTS: In all patients, one period of 11,000 to 36,000 beats could be evaluated. Mean correlation coefficients were best for systolic blood pressure (r = 0.73), followed by mean blood pressure (r = 0.68) and diastolic blood pressure (r = 0.61), and, finally, heart rate (r = 0.52). In 7 patients, the correlation coefficient for systolic blood pressure was > 0.9; but, in 4 patients, it was < 0.5. CONCLUSIONS: We conclude that the correlation between 1/PAT and systolic blood pressure is not strong enough to serve as a marker for blood pressure changes in critically ill infants and children. This may be due to changes of the preejection period, which is part of the PAT.

Adolescent

Mitral and aortic regurgitation in 84 patients with mucopolysaccharidoses.

UNLABELLED: In echocardiographic and necropsy studies nodular thickening of the mitral valve and, less frequently, of the aortic valve has been found in 60%-90% of patients with mucopolysaccharidoses (MPS). Little is known about the haemodynamic consequences of these morphological changes. In this study 84 unselected patients with different enzymatically proven MPS and 84 age and sex matched, healthy persons were studied prospectively by colour Doppler flow mapping. The patients' age ranged from 1 to 47 years (median 8.1 years). Mitral and aortic regurgitation were defined as a holosystolic or holodiastolic jet originating from the valve into the left atrium or the left ventricular outflow tract, respectively, with peak velocities exceeding 2.5 m/s. Of the 84 patients with satisfactory studies, mitral regurgitation was detected in 64.3% and aortic regurgitation in 40.5%, respectively. Regurgitation was severe in 4.8% of mitral valves and 8.3% of aortic valves. The frequency of aortic and/or mitral regurgitation was 75% in all patients, 89% in MPS I, 94% in MPS II, 66% in MPS III, 33% in MPS IV, and 100% in MPS VI. Combined mitral and aortic regurgitation was present in 29% of our patients. None of the control persons showed mitral or aortic regurgitation. CONCLUSION: Aortic and mitral regurgitation are more frequent in patients with MPS than previously thought and that therefore these patients should have regular colour Doppler flow mapping and antibiotic prophylaxis when required.

Adolescent

Norepinephrine, enoximone, and nitric oxide for treatment of myocardial stunning and pulmonary hypertension in a newborn with diaphragmatic hernia.

A newborn with right diaphragmatic hernia suffered myocardial stunning and suprasystemic pulmonary hypertension secondary to postpartal asphyxia. In addition to conventional therapy, norepinephrine, enoximone, and inhalational nitric oxide were successfully used. Norepinephrine improved myocardial perfusion pressure; the addition of enoximone, a phosphodiesterase-inhibitor, to beta-adrenergic agents increased cardiac performance. with decreasing concentrations of inhalational nitric oxide, severe pulmonary hypertension resolved after a few days, suggesting that transient endothelial dysfunction was partially responsible for pulmonary vasoconstriction in the newborn with congenital diaphragmatic hernia.

Enoximone

Age-dependent changes in the beta-adrenoceptor-G-protein(s)-adenylyl cyclase system in human right atrium.

With increasing age, cardiac beta-adrenoceptor function decreases. To study possible mechanisms underlying this process, we assessed in right atrial appendages from 52 patients of different ages (group A, < 20 years, mean age 3.7 +/- 1.0 years, n = 20; group B, 20-50 years, mean age, 37.9 +/- 2.3 years, n = 9; group C, > 50 years, mean age 66.1 +/- 1.5 years, n = 23) without apparent heart failure who were undergoing open heart surgery beta-adrenoceptor number and subtype distribution (by (-)-[125I]-iodocyanopindolol [ICYP] binding), adenylyl cyclase activity, and Gs- and Gi-protein alpha-subunits (by quantitative Western blotting). beta-Adrenoceptor number in the three groups was not significantly different; in contrast, basal, 10 microM GTP-, 100 microM isoprenaline (ISO), 10 mM NaF-, 100 microM forskolin-, and 10 mM Mn(2+)-stimulated adenylyl cyclase activity was significantly higher in group A than in group B and was further decreased in group C. Similarly, 100 microM terbutaline-, 100 microM histamine-, and 100 microM 5-HT-stimulated adenylyl cyclase activity significantly decreased from group A to group C. Moreover, all these adenylyl cyclase parameters were significantly negatively correlated with the age of the patients. Although Gs alpha was not altered, Gi alpha in group C was significantly higher than in group A; moreover, there was a weak but significant positive correlation between Gi alpha and the age of the patients. We conclude that an impairment of the activity of the catalytic unit of adenylyl cyclase is involved in the decrease in cardiac beta-adrenoceptor function with age; an increase in Gi alpha might contribute further to the reduced beta-adrenoceptor function.

Adenylyl Cyclases

Independent right lung high frequency and left lung conventional ventilation in the management of severe air leak during ARDS.

Pulmonary air leaks are one of the most common problems in patients with the adult respiratory distress syndrome, ARDS. We report what we believe to be the first case in which unilateral high-frequency ventilation combined with contralateral conventional positive pressure ventilation has been used successfully to manage severe air leak in an infant with ARDS.

Bronchial Fistula

Determination of cardiac output by an angle and diameter independent dual beam Doppler technique in critically ill infants.

OBJECTIVE: To compare cardiac output measurements in critically ill infants by the dual beam Doppler and thermodilution techniques. DESIGN: Prospective direct comparison of the two techniques. For statistical evaluation one randomly assigned paired measurement of every patient was used. SETTING: Paediatric intensive care unit in a university hospital. PATIENTS: 18 infants after open heart surgery aged 4-25 months (weight 4-10 kg). INTERVENTIONS: Cardiac output measurements by dual beam Doppler and thermodilution techniques were performed within 10 minutes of each other and without knowledge of the results of the other methods. Multiple measurements were performed on some patients with a pharmacological or electrophysiological intervention or with a minimum of six hours between each pair of measurements. MEASUREMENTS AND MAIN RESULTS: Three patients were excluded because of an inadequate Doppler signal or a significant residual shunt. Cardiac output measurements ranged from 0.4 to 2.2 l/min for the thermodilution technique and from 0.5 to 2.1 l/min for the dual beam Doppler technique. Agreement between both methods was acceptable. The mean difference between the two methods was 0.026 l/min with two standard deviations ranging from -0.20 to 0.26 l/min. CONCLUSION: The dual beam Doppler technique was shown to have promise for the non-invasive determination of cardiac output in critically ill infants.

Cardiac Output

Evaluation of the valve area underestimation by the continuity equation.

During the last years, noninvasive determination of the aortic valve area by Doppler echocardiography using the continuity equation became popular. However, a systematic valve area underestimation of about 15% compared to invasive measurements using the Gorlin formula has been reported. The cause therefore is unknown. The purpose of this study was to evaluate whether the valve area underestimation by the Doppler method might be due to differences in the hydrodynamic background of both methods. This comparison is facilitated by the fact that the Gorlin formula is based on the continuity equation. Compared to the continuity equation, there are four changes within the Gorlin formula: (1) the additional use of a discharge coefficient, which leads to valve area overestimation by the factor 1.17; (2) neglect of the pre-stenotic velocity, causing further overestimation by the factor 1.036 (in mild stenosis this factor may be 1.18 and more); (3) the wrong calculation of the mean pressure drop, which leads to a mean change by the factor 0.95, and (4) the incorrect substitution of the height by the pressure drop in the derivation of the Gorlin formula causes underestimation by the factor 0.97. Combining these four factors results in valve area overestimation of the Gorlin formula compared to the continuity equation by the factor 1.12. This explains to a large extent the valve area underestimation by the continuity equation.

Aortic Valve

[Genetic subjects in Hungarian dental literature].

The author classifies the Hungarian dental publications on genetical aspects into the following groups: 1. tooth and dental arch characteristics, disorders and illnesses, 2. oral cavity and surrounding area characteristics, disorders and illnesses, 3. mandible and surrounding bone characteristics, disorders and illnesses, 4. hereditary illnesses involving oral symptoms, 5. summarizing publications.

Humans

Effects of tolazoline and prostacyclin on pulmonary hypertension in infants after cardiac surgery.

OBJECTIVE: To evaluate the hemodynamic effects of tolazoline and prostacyclin in infants with pulmonary vasospasm after cardiac surgery. DESIGN: Prospective cohort study. SETTING: Pediatric ICU. PATIENTS: The cohort consisted of 42 infants and children with congenital heart disease and pulmonary hypertension who underwent corrective surgery and were monitored postoperatively using pulmonary artery catheters. Fourteen infants (2 to 12 months old) in this group required postoperative treatment with tolazoline or prostacyclin. INTERVENTIONS: Tolazoline was administered as a bolus of 0.5 mg/kg for treatment of persistent pulmonary hypertension or acute pulmonary hypertensive crisis. If its effectiveness was proved after 30 mins by hemodynamic measurements, a continuous iv infusion of 0.5 mg/kg/hr was established. Higher doses of tolazoline were avoided. If tolazoline treatment did not fulfill the criteria for pulmonary vasodilation, prostacyclin was given by continuous iv infusion at a starting rate of 5 ng/kg/min, followed by 10 ng/kg/min. In three patients, the infusion rate was increased to 15 ng/kg/min. RESULTS: Bolus administration of tolazoline resulted in a distinct pulmonary vasodilation in seven infants: mean pulmonary artery pressure and pulmonary vascular resistance decreased by an average of 35% and 45%, respectively. In these patients, tolazoline was infused over the following 12 to 72 hrs. One infant who received tolazoline for 72 hrs developed a clinically important gastrointestinal hemorrhage. In seven nonresponders to tolazoline, prostacyclin (PGI2) at an infusion rate of 5 ng/kg/min led to pulmonary vasodilation in five patients, at an iv infusion rate of 10 ng/kg/min in all seven infants studied. The latter dose of PGI2 reduced the mean pulmonary artery pressure by an average of 37%, and pulmonary vascular resistance by 43%. Transient withdrawal of prostacyclin in five infants demonstrated its short half-life and clinical effectiveness. Apart from a facial flush, no side-effects were encountered using PGI2 as an infusion over durations ranging from 12 to 504 hrs. CONCLUSIONS: These data suggest that, if tolazoline in a relatively low dose proves to be inefficient, prostacyclin can still be used as a safe and effective drug for treatment of pulmonary vasospasm. Prostacyclin offers more than a pharmacologic alternative to increased tolazoline dosages.

Drug Evaluation

Counterflow affinity isotachophoresis on cellulose acetate membranes.

Counterflow isotachophoresis on cellulose acetate membranes of human alpha-fetoprotein (AFP) was performed with concanavalin A, lentil lectin, and castor bean lectin driven by electroendosmotic counterflow. This counterflow caused a uniform stream of lectin to migrate towards the cathode against AFP with carrier ampholytes in steady-state position. Retardation of microheterogeneity forms bound to lectins was observed, giving results comparable to standard crossed affinity immunoelectrophoresis. Smaller amounts of lectins and more diluted samples of AFP could be used in the described method.

Ricinus communis

[Incorrect technical terms in Hungarian dental terminology].

The standpoint of the Hungarian Scientific Academy in case of medical orthography is described. Attention is called that anatomic denominations have to be concordant with the currently valid international nomenclature. Improper technical terms frequently occurring in dental papers and parlance are pointed out and the correct denominations are expounded.

Dentistry

[Catheterization of the jugular venous bulb in comatose children].

Ischemia and hypoxia are frequent potential sources of secondary brain damage after a variety of brain injuries. Cerebral oxygen extraction may be altered by coma as well as therapeutic interventions. In consequence, monitoring of cerebral O2 availability and utilization has become an important challenge for clinicians. However, measurement of cerebral oxygen extraction in children currently is not included into routine clinical care. This paper describes the measurement of O2-saturation in the jugular bulb in four comatose infants and children (in one continuously) following cardiac arrest or head injury. Our data demonstrate that this procedure served as a valuable tool in the management of those patients. Arterio-jugular oxygen content and lactate differences were used for the establishment and adjustment of therapeutic procedures and moreover, provided relevant information for the interpretation of other cerebral surveillance parameters.

Adolescent