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Biomedical subjects

R Henze

Publications and source records attributed to R Henze.

13 recordsLinked to original sources
PubMed2001

[Isolated left ventricular papillary muscle rupture: a rare event after blunt thoracic trauma].

We report about a 20-year old man, who suffered from a car accident under the influence of ecstasy. Although he had no visible injuries at the chest, the accident caused an isolated rupture of a papillary muscle of the mitral valve. A review of the literature shows the rarity of this kind of injury. The mechanisms of traumatic papillary muscle rupture, the diagnosis, therapy and complications are discussed.

Accidents, Traffic↗
PubMed2000

Sodium nitroprusside in patients with compromised left ventricular function undergoing coronary bypass: reduction of cardiac proinflammatory substances.

OBJECTIVE: The aim of the present study was to investigate whether the nitric oxide donor sodium nitroprusside can reduce the cardiac inflammatory response during coronary artery bypass grafting in patients with severely compromised left ventricular function. METHODS: Patients (n = 30) were assigned to receive placebo or sodium nitroprusside (0.5 microg. kg(-1). min(-1)) for the first 60 minutes of reperfusion. Interleukin 6, interleukin 8, and tumor necrosis factor alpha levels; platelet adhesion molecule CD41 and CD62 levels; and CD11b on leukocytes were determined in the radial artery and coronary sinus before cardiopulmonary bypass and during reperfusion (1, 5, 10, 35, and 75 minutes). RESULTS: At 1 minute of reperfusion, coronary venous levels of CD41-positive polymorphonuclear leukocytes were 8% lower than arterial levels in the placebo group and 18% higher in the sodium nitroprusside group (P =.021). At 5 minutes of reperfusion, the respective levels were 29% and 1% for interleukin 6 (P =.015), -5% and 20% for CD41-positive monocytes (P =.032), and -2% and 16% for CD11b-positive monocytes (P =.038). At 10 minutes of reperfusion, these levels were -14% and 21% for CD41-positive monocytes (P =.006). At 35 minutes of reperfusion, these levels were -13% and 7% for CD41-positive monocytes (P =.017), -41% and 23% for CD11b-positive monocytes (P =.001), and 7% and 25% for CD62-positive platelets (P =. 041). At 75 minutes of reperfusion, the levels were 15% and -7% for tumor necrosis factor alpha (P =.025) and -10% and 10% for CD62-positive platelets (P =.041). CONCLUSIONS: Transcardiac production of proinflammatory cytokines is reduced in patients undergoing coronary artery bypass grafting treated with the nitric oxide donor sodium nitroprusside. At the same time, less activated leukocytes and platelets are retained in the coronary circulation.

Aged↗
PubMed1999

[Interventional catheter occlusion of the atrial septal defect of the secundum type--experiences with "CardioSeal" and "Angel Wings"].

Between July 1996 and July 1998, 34 patients (female n = 16, male n = 18) were scheduled for catheter--interventional occlusion (ASDO) of an atrium septum defect of secundum type (ASD II). Median age was 7.9 years (2.5-54.6), weight 23.1 kg (9-97). 9 defects were closed with "Angel Wings" (AW) and 25 ASD occlusions were attempted with "CardioSeal" (CS). 30 patients had simple ASD II, 3 persisting foramen ovale with suspected paradoxal cerebral embolization and 1 significant residual shunt at atrial level after corrective heart surgery for interrupted aortic arch type B. ASDO was successful in 31/34 cases (91%). One CS was removed surgically due to significant left to right shunt after release and two CS devices were withdrawn back into the sheath. Median ASD diameter was 11.9 mm (6-16), balloon occlusive diameter was 15 mm (6-20) and median left to right shunt was 40% (6-64%). On follow up minimal left to right shunt was seen in 5/31 patients (16%). In selected patients catheter--interventional ASDO may be a good alternative to surgical ASD closure.

Adolescent↗
PubMed1992

Total intravenous anesthesia for infants and children undergoing correction of tetralogy of Fallot: sufentanil versus sufentanil-flunitrazepam technique.

The effects of two total intravenous anesthetic techniques were compared in 20 infants and children undergoing primary correction of tetralogy of Fallot (TOF). All patients (mean body weight, 11.4 +/- 4.2 kg; range, 6 to 20 kg; mean age, 32 +/- 21 months, range, 7 to 85 months) were premedicated with atropine, 0.02, mg/kg, morphine, 0.2, mg/kg, and flunitrazepam, 0.04 mg/kg, intramuscularly, 1 hour preoperatively. Anesthesia was induced with 1 microgram/kg of sufentanil (S) and pancuronium, 0.1 mg/kg, intravenously. Patients were ventilated with 100% oxygen. Hemodynamic parameters, heart rate (HR), systolic (SBP), diastolic (DBP) and mean arterial blood pressure (MAP), central venous pressure (CVP), and peripheral arterial blood oxygen saturation (SaO2) were recorded. Plasma concentrations of S, epinephrine (E), norepinephrine (NE), and blood gases were determined. To obtain a further depth of anesthesia, 10 patients (SM group) received 4 micrograms/kg of S and 10 patients (SF group) received 4 micrograms/kg of S in combination with flunitrazepam, 40 micrograms/kg, in a randomized manner. Measurements were made before and after induction of anesthesia, before and after anesthetic loading, 2 minutes after sternotomy, 15 minutes after initiation of extracorporeal circulation (ECC), and at sternal closure. Peak values for plasma S concentrations of 3.14 +/- 1.13 (SM group) and 3.45 +/- 97 ng/mL (SF group) were found before sternotomy. Following intubation HR, SBP, DBP, and MAP remained close to values measured before induction, but SaO2 increased significantly (P less than 0.01) in all patients. HR, SBP, and MAP decreased during anesthetic loading in both groups. Hemodynamics and plasma E and NE remained essentially unchanged after sternotomy in the SF group.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Intravenous↗
PubMed1989

Reduction of homologous blood requirement in cardiac surgery by intraoperative aprotinin application--clinical experience in 152 cardiac surgical patients.

The protease inhibitor aprotinin interacts with plasmin and kallikrein, which are generated in cardiac surgery during cardiopulmonary bypass (CPB). The influence of high-dose aprotinin application (2 million kallikrein inactivator units given i.v. at the beginning of anaesthesia followed by a 500,000 KIU/h infusion throughout the operation and additional 2 millions KIU added to the priming of the oxygenator) on perioperative blood loss and donor blood requirement was studied in 152 adult cardiac surgical patients. This group was compared to 317 patients having cardiac surgery without the application of aprotinin. Aprotinin reduced the homologous blood requirement by 43% (1783 +/- 100 vs 1015 +/- 131 ml, p less than 0.05), while the reduction of postoperative blood loss was 29% (1070 +/- 43 vs 761 +/- 51 ml, p less than 0.05). Fortytwo percent of the aprotinin treated patients completed their hospital stay without having any donor blood transfusion compared to 18% in the group without aprotinin. The blood saving effect was even more pronounced in operations with prolonged perfusion times. Intra- and postoperative complications were equally distributed in both groups. The blood-saving effect of aprotinin may be due to a platelet-preserving effect and/or kallikrein inhibition during CPB. There were no clinically relevant side effects related to aprotinin observed. It is concluded that high dose aprotinin therapy reduces both postoperative blood loss and homologous blood requirement, and therefore the routine application of aprotinin during cardiac surgical procedures is to be recommended.

Aprotinin↗
PubMed1985

Temperature dependence of dielectric relaxations in alpha-elastin coacervate: evidence for a peptide librational mode.

The dielectric permittivity of alpha-elastin coacervate is reported over the frequency range of 1 MHz to 1000 MHz and the temperature dependence from 6.8 degrees C to 70 degrees C is also reported. A temperature-dependent simple Debye-type relaxation is observed with a correlation time of 8 nsec (40 degrees C) which is similar to that of the polypentapeptide of elastin (i.e. 7 nsec at 40 degrees C) where the band has been assigned to a peptide librational mode. By analogy this allows for the first assignment of a peptide librational mode in a naturally occurring polypeptide or protein. The strong spectrally localized band indicates a regularity of structure. The low temperature dependence of the correlation time, giving a 1.7 kcal/mole enthalpy of activation, is consistent with torsional motions associated with a peptide librational mode.

Elastin↗
PubMed1984

Polypentapeptide of elastin: temperature dependence correlation of elastomeric force and dielectric permittivity.

The polypentapeptide of elastin, (L X Val1-L X Pro2-Gly3-L X Val4-Gly5)n, when gamma-irradiation cross-linked in the coacervate state, is shown by means of thermoelasticity data to be a relatively simple system on which to study polypeptide elasticity. Strikingly, the temperature dependence of the elastomeric force exhibited by cross-linked polypentapeptide coacervate is shown to be proportional to the temperature dependence of the dielectric permittivity of the polypentapeptide coacervate over the critical temperature range of 25 degrees C to 55 degrees C where the force increases five fold. This demonstrates that the mobility of dipolar elements are in large part responsible for the elastomeric force and that dielectric relaxation studies contain the potential for identifying the nature of the dynamic elements responsible for bioelasticity.

Chemical Phenomena↗
PubMed1984

The dielectric permittivity spectrum of aqueous colloidal phospholipid solutions between 1 kHz and 60 GHz.

The dielectric permittivity spectrum between 1 kHz and 60 GHz of aqueous colloidal solutions of predominantly zwitterionic phospholipids is presented from results of previous and recent measurements. It shows three dispersion/loss regions around 22 GHz. 80 MHz and below 40 MHz (30 degrees C) which are attributed to rotational diffusion of the water molecules and of the zwitterionic phosphorylcholine groups, and to limited translational diffusion of ionic lipid molecules and/or its counterions. respectively. Merely a few mole percent of ionic lipids cause comparatively large dielectric dispersion. Ignoring the fact that such impurities may be present in zwitterionic phospholipid compounds, which have not been especially purified, this has led to misinterpretation of the dielectric spectrum in the past. An approximate quantitative description of the measured spectra is given for vesicle solutions with only very small additional low-molecular-weight salt content. It reproduces the sensitive dependence of the ionic lipid-induced dielectric dispersion (step height and frequency) on various parameters: phospholipid vesicle size. ionic lipid content, as well as the self-diffusion coefficient of the ionic lipid molecules and of its counterions, moving within the phospholipid bilayers or on their surface, respectively.

Journal Article↗
PubMed1982

Dielectric relaxation studies of ionic processes in lysolecithin-packaged gramicidin channels.

Dielectric permitivities have been determined for suspensions of lysolecithin packaged malonyl gramicidin channels over the frequency range of 5 kHz to 900 MHz and under conditions of approximately equimolar concentrations (approximately 10mM) of channels and salts. The salts were lithium chloride, sodium chloride and thallium acetate. A relaxation process unique to the thallium acetate-channel system was observed which on analysis gave rise to a relaxation time at 25 degrees of 120 msec. The permitivity data, as well as a comparison of binding constants, indicate that the relaxation process results from TI+ being bound within the channel and more specifically from an intrachannel ion translocation with a rate constant of approximately 4 x 10(6) sec-1 and with an energy of activation of less than 6.7 kcal/mole. These data compare favorably with data from conductance studies on planar bilayers and with ion and carbon-13 nuclear magnetic studies on the lysolecithin packaged malonyl gramicidin channels which combine to indicate that the relaxation process is due to the jump of the thallium ion across a central barrier.

Circular Dichroism↗
PubMed1981

Thyroxine-binding globulin: investigation of microheterogeneity.

Preparations of T4-binding globulin (TBG) from human serum was performed using only two affinity chromatography steps. Purity of the protein was demonstrated by a single band in overloaded disc and sodium dodecyl sulfate electrophoresis, equimolar binding to T4, and linearity in sedimentation velocity run. The molecular weight was calculated to be 60,000 +/- 3,000 daltons (n = 3), the sedimentation coefficient was 3.95S, and the Stokes' radius was 37 A. The amino acid composition was found to be in good agreement with the calculations of other authors. By isoelectric focussing (IEF), pure TBG showed four main bands at pH 4.25, 4.35, 4.45, and 4.55 together with several fainter bands. The N-acetylneuraminic acid (NANA) content of the four TBG bands isolated by preparative IEF was found to decrease from 10.2 mol NANA/mol TBG in the band at pH 4.25 to 4.8 mol NANA/mol TBG in the band at pH 4.55. No significant difference in the affinity constants of the TBG bands to T4 was found. The affinity constants for TBG ranged from 3.1 x 10(9) to 7.2 x 10(9) M-1. Sequential kinetic desialylation of pure TBG resulted in a progressive tendency toward one major band at pH 6.0. In native sera, microheterogeneity of TBG was detected after IEF on polyacrylamide gel plates by immunofixation. The typical TBG patterns shown by pure TBG were also found in normal subjects. Characteristic deviations from this pattern were found in the sera of females during estrogen therapy or pregnancy, where there was a gradual increase in density of the band at pH 4.25 and the appearance of an additional band at pH 4.15. In sera from patients with liver disease and elevated TBG levels, there was a fading of the acidic bands, whereas the more alkaline band at pH 4.55 was intensified. It is therefore proposed that microheterogeneity of TBG is caused by differences in NANA content and that variations of TBG patterns in native sera may reflect altered TBG synthesis or degradation. A genetically related microheterogeneity of TBG could not be demonstrated after examination of 800 sera, including 2 families with quantitative TBG deficiency.

Amino Acids↗
PubMed1979

Motion of the lengthened zwitterionic head groups of C16-lecithin analogues in aqueous solutions as studied by dielectric relaxation measurements.

Phosphatidyl choline analogues with increased phosphate-trimethylammonium distance were synthesized and aqueous solutions of these bilayer forming phospholipids were prepared. Dielectric spectra of the solutions were measured at several temperatures around the crystalline/liquid-crystalline phase transition temperature of the samples. The observed data are treated in terms of a Debye relaxation function and also of a relaxation function based on a theoretical model of the aqueous solutions of multibilayer vesicles. As a noteworthy result, a pronounced cooperativity effect in the diffusive motions of the zwitterionic head groups emerges. The degree of cooperativity depends on the radius of curvature of the multibilayer vesicles and also on the length of the phospholipid zwitterions. The values for the mobility of the trimethylammonium group are of the same order of magnitude as those for the mobility of whole phospholipid molecules in its lateral diffusive motion. Indications for a phase transition at a temperature above the main transition temperature are found with solutions of C16- lecithin analogues with 9 and 10 methylene groups between the phosphate and the trimethylammonium group.

Journal Article↗
PubMedDate not supplied

Temporary pulmonary vein stenosis during intraoperative transesophageal echocardiography in total cavopulmonary connection.

Two patients operated on by one of the authors (MK) developed hemodynamic instability after otherwise uneventful completion of total cavopulmonary anastomosis with an extracardiac tube. In both, a stenosis of the right pulmonary veins was demonstrated during routine intraoperative transesophageal echocardiography. The transesophageal probe was found to be the underlying problem. Apparently, the pulmonary veins became compressed between the probe and the extracardiac conduit.

Aorta, Thoracic↗