Search PubMed⌕ Search

Biomedical subjects

H Meisner

Publications and source records attributed to H Meisner.

At least 127 records · Page 7Linked to original sources
PubMed1978

[Surgery in newborns and infants with cyanotic cardiac malformations: indication and technique of emergency operations and urgent early surgical interventions (author's transl)].

Between April 1974 and September 1977, 368 infants underwent surgery at the German Heart Center. 287 were less than 1 year of age, and 81 were between the ages of one and two years. In 90 patients (= 24.4%) surgery was necessary because of cyanotic lesions. Within this group corrective procedures were performed in 36 infants during the first year of life, and in 33 during the second year of life, while palliative measures were carried out in these age groups in 15 and 6 infants, respectively. Urgent corrective surgery is indicated as a life-saving measure in neonates with total anomalous pulmonary venous connection (TAPVC) since this lesion is not amenable to either medical nor palliative interventions. Of 10 neonates and young infants who underwent corrective surgery for TAPVC, 3 died during the early post-operative period and 1 subsequently. Balloon atrial septostomy palliatively employed for transposition of the great arteries (TGA) may render only temporary improvement in the clinical status of young infants. In these infants, more favourable results can be achieved through early, functionally-corrective surgery (Mustard-Brom procedure). In 7 infants who underwent correction of TGA during the first year of life there was 1 post-operative death. There was no post-operative mortality in 18 infants whose age at the time of operation was between 1 and 2 years. In the presence of TGA combined with ventricular septal defect there were 3 deaths in 8 infants operated on during the first year of life and none in the 3 who underwent surgery during the second year of life. In the same age groups, early correction of tetralogy of Fallot (TOF) was performed in 11 infants (with 2 deaths) and in 10 infants (with one death), respectively. Thus, in the absence of preclusive, complex anomalies, early surgical correction of congenital cyanotic lesions in young infants consistently yields results superior to that of palliation or two-stage procedures.

Age Factors↗
PubMed1978

[Therapy of cardiac arrest: cardiopulmonary resuscitation (author's transl)].

Reports of successful attempts at resuscitation have been published for more than 200 years, but systematic analysis of an optimal technique has been undertaken for only the last 20 years. As a result of these experiments and of the many years of experience of resuscitation teams, extensive recommendations were formulated by a conference on cardiopulmonary resuscitation of the "American Heart Association" in May 1973. The superiority of mouth-to-mouth resuscitation in comparison to older methods and the importance of the triple-airway-maneuvre for the maintenance of a patent airway were pointed out. Despite the fact, that an exact numerical relationship of cardiac massage to artificial ventilation is not particularly important, an optimal procedure was established. However, the worldwide spread of cardiopulmonary resuscitation should not lead to this procedure being performed just somehow, since correct execution, if possible without interruptions, is essential for the effectiveness of the remaining circulation and the response to medications and defibrillation. The prognosis varies widely depending on the group of patients being examined. In 1976 34 resuscitations were performed on adult patients of the Cardiothoracic Intensive Care Unit of the German Heart Centre in Munich (5.5% of patients admitted). Seven patients survived primarily. Of these, four patients died within the subsequent twentyfour hours. One patient survived with permanent brain damage, two could eventually be discharged from the hospital without complications.

Coronary Care Units↗
PubMed1978

Antilipolytic effects of chlorophenoxyisobutyrate and warfarin in adipocytes.

This study was designed to examine whether displacement of free fatty acids (FFA) from albumin (BSA) can explain the antilipolytic effect of chlorophenoxyisobutyrate (CPIB). Warfarin, which binds to albumin with equal affinity, was used to test the generality of this mechanism. The procedure was to measure the concentration of free drug needed to inhibit hormone-stimulated lipolysis in isolated rat epididymal fat cells, and the effect on this process of albumin, which binds both FFA ligand and drug. The free drug concentration was initially obtained by ultrafiltration studies with albumin and 14C-labeled CPIB or 14C-labeled warfarin in the absence of cells. When epinephrine-activated lipolysis was measured, inclusion of 0.3 mM albumin decreased the free CPIB concentration required for 50% inhibition from 1.8 mM (-BSA) to 0.08 mM. Warfarin also inhibited lipolysis more effectively in the presence of albumin, with 50% inhibition at 0.06 mM (+BSA) vs. 0.7 mM (-BSA). Both drugs showed a similar high-affinity binding constant to albumin of n = 1, k = 2--4 X 10(5) M-1, and both competitively displaced [14C]stearate, provided that a hydrophobic trap was present. The results are consistent with the possibility that the antilipolytic effect of CPIB and warfarin is mediated by way of a competitive displacement of FFA from albumin, or an analogous cellular binding site, with subsequent feedback inhibition of lipolysis.

Adipose Tissue↗
PubMed1977

[Intraoperative control of revascularisation and indication for reintervention (author's transl)].

Among the procedures of intraoperative control of revascularisation the simple method of probe passage for determination of technical mistakes during anastomoses is very valuable. More informative is the measurement of bypass-flow using an electromagnetic flowmeter. We compared this method with the results of intraoperative angiography, which is performed in our hospital routinely for immediate control of revascularisation. A comparison of 214 veins demonstrated a good statistically significant correlation between run-off and bypass-flow. The quality of the anastomosis can only be judged by intraoperative angiography and does not correlate with a low bypass flow. According to these measurements it was necessary in four cases to perfrom an intraoperative reintervention.

Angiography↗
PubMed1977

[Surgical repair of Ebstein's disease (author's transl)].

In 1976 4 patients with Ebstein's disease underwent surgical repair. In one patient (22 yrs.) the tricuspid valve leaflets were suitable for reconstructive surgery using Hardys method in addition to De Vegas annuloplasty. In the other three cases (17, 29, 51 yrs. old) excision of the malformed tricuspid valve was necessary, and porcine heterografts of greatest possible diameter were implanted. Three patients improved considerably 9 months postoperatively. The fourth patient, a 51 years old woman, died 2 days postoperatively on cardiac failure. From our own results and based upon reports from the literature we conclude that reconstructive surgery of the tricuspid valve should be preferred to replacement. If valve replacement is necessary, bioprostheses ought to be used. At the age of 15 to 40 years, surgical repair seems to have the best prognosis in patients with Ebstein's malformation.

Adolescent↗
PubMed1977

Regulation of lipolysis in adipose tissue.

The normal human or animal has a series of finely coordinated and overlapping control mechanisms that regulate the storage or release of fat according to the overall energy requirements of the body. We have examined only one side of this system, the part responsible for the release of fatty acids from adipose tissue. Considerable information is available on the extracellular factors that control lipolysis on a minute-to-minute or day-to-day basis, but less is known about long-term regulation or about the precise role of intracellular factors that almost surely condition the response of the fat cell to external stimuli. When one poses the question of what determines the overall fat mass or adiposity of an individual, even less is known. Psychogenic factors regulating food intake, circulating hormonal signals, and local regulators of metabolism in the adipose tissue may all play a role. This remains an intriguing but elusive problem to be answered by future research.

Adenosine↗
PubMed1977

pH as an indicator of free fatty acid release from adipocytes.

A convenient method of measuring initial rates of free fatty acid efflux from isolated adipocytes during triglyceride breakdown by hormone-sensitive lipase is described. The procedure is based on the dissociation of protons from carboxyl groups of free fatty acids. A recording pH meter is used to monitor H+ concentration in the medium continuously as an index of free fatty acid release. A stoichiometric relationship was demonstrated between proton release and extracellular free fatty acid concentration as determined by the 63Ni radioassay method of Ho (1970. Anal. Biochem. 36: 105-113). An acid pH (6.8) caused a reduction in proton release, which was immediately and completely reversed by raising the pH to 7.4.

Adipose Tissue↗
PubMed1976

[Hemodynamic studies after the implantation of Hancock-heart valves (author's transl)].

Velocity profile, pressure gradient across the valve and blood flow have been measured in 10 patients after the implantation of bioprostheses of the sizes 27 and 29 millimeters in aortic position. According to these hemodynamic measurements the use of bioprostheses for the aortic valve replacement is recommendable. The low flow velocities in the area of the muscle containing valve cusp did not effect a detectable stenosis intraoperatively under the conditions of rest. The hemodynamic data showed no differences between the Hancock-Zuhdi and the Edwards-Carpentier bioprostheses. Despite of good hemodynamic conditions and a low risk of thromboembolic complications after the aortic valve replacement with bioprostheses reservation is recommended to its clinical use until the long term mechanical stability (more than 6 years) of the biological heart valve prosthesis has been secured.

Adolescent↗
PubMed1976

[Direct measurement of papillary muscle dynamics in the intact canine left ventricle during acute coronary occlusion (author's transl)].

UNLABELLED: The functions of the normal and ischemic papillary muscle in the intact canine heart were studied using an ultrasonic transit time method. Miniaturized piezoelectric crystals (1.5-2 mm 0) were implanted during extracorporeal circulation into the root and tip of the anterior and posterior papillary muscle of the left ventricle. RESULTS: 1. Phasic changes of left ventricular geometry during the heart cycle determine the dynamic pattern of papillary muscle movements. 2. The amplitude and velocity of papillary muscle length is directly related to those of myocardial wall segments. 3. Experimental ischemia induces total dysfunction of the papillary muscle within seconds. 4. Despite total muscle dysfunction no mitral insufficiency occured.

Animals↗
PubMed1975

[Instantaneous blood flow velocity profiles before and after aortic valve replacement (author's transl)].

In 17 patients the instantaneous velocity profile was recorded before and after aortic valve replacement (Starr-Edwards, Björk-Shiley, Lillehei-Kaster). A single gated pulsed Doppler Ultrasonic flownmeter was used for analysis. Distal of these valves a flat flow profile was recorded showing high velocity gradients near the walls. As a main cause of this, numerous eddies and turbulent flow have been suggested. Downstream of a Starr valve a flat profile appears with a slowing down of forward flow just behind the ball. The disk valves Lillehei-Kaster and Björk-Shiley demonstrated a higher flow velocity in direction to the larger opening. The "in vivo" studies have been supported by "in vitro" measurements. The highest flow velocities were above 100 cm/sec and thus, according to Reynolds definition, in the turbulent range. The turbulent flow produces a washing effect, which is emphasized during the cardiac cycle. The importance of these data can be discussed by clinical results only.

Aorta↗
PubMed1975

[Ultrasound transit-time method for evaluation of regional myocardial function (author's transl)].

The validity of an ultrasound transit-time method for defining local function was evaluated under experimental conditions in the anaesthetized open chest dog. Miniaturized piezoelectric crystals (1,5-2 mm phi) functioning as emitters and receivers were inserted into different depths of the myocardium to study the contraction patterns of defined muscle segments in different muscle layers and the dynamic changes of left ventricular wall thickness during the heart cycle. Changes in myocardial function were induced by coronary stenosis or occlusion and by the application of drugs. This method was shown to be a sensible and reliable tool for the evaluation of local myocardial function.

Animals↗