Biomedical subjects

A Wischnik

Publications and source records attributed to A Wischnik.

48 records · Page 3Linked to original sources

PubMed1982

[Effect of the combination of the beta-1-blocker metoprolol with the tocolytic fenoterol on uteroplacental hemodynamics and fetal cardiovascular sensitivity with particular consideration of intrauterine fetal malnutrition. Results of animal experiments].

7 merino sheep in an advanced state of pregnancy received oxytocin for labour induction under the conditions of control, monotherapy with the beta 2-adrenergic tocolytic fenoterol, combination of the latter with the beta 1-blocking substance metoprolol (Beloc). Likewise, the effect of labour induction was investigated when putting an artificial stenosis around the a. uterina during simultaneous application of fenoterol alone and combined with metoprolol. The following parameters were measured: aortic pressure and heart rate both in dam and fetus, maternal left ventricular pressure rising velocity, intrauterine pressure, uterine blood flow, uterine vascular resistance and regional myometrial contraction patterns by means of an ultrasonic transit time method. Measurement of maternal cardiovascular parameters once more showed, that maternal cardiovascular derangements could excellently be antagonised by metoprolol. Intrauterine pressure measurements as well as regional myometrial contraction patterns proved evidence, that there is no counteraction between the beta 2-mimetic substance and the beta 1-blocking agent concerning the tocolytic effect. When artificially stenosing the a. uterina, a rise in uterine contraction status could be observed; this hypoxic augmentation of myometrial tone could almost completely be reverted when combining fenoterol and metoprolol. Finally, no difference could be observed in the reaction of fetal cardiovascular parameters to reduced uterine blood flow before and after application of the beta 1-blocking substance metoprolol.

Animals↗

PubMedDate not supplied

Risk-benefit assessment of tocolytic drugs.

beta 2-Mimetics are the principal agents used for myometrial relaxation. As all the available drugs also have beta 1-stimulant effects, the various side effects (cardiovascular, pulmonary and metabolic) require a critical consideration of the clinical indications, thorough supervision and combined therapeutic concepts. With regard to clinical indications, 'prophylactic tocolysis' frequently turns out to be unnecessary, as does the treatment of physiological uterine contractions during pregnacy which have no effect on the cervix. The benefit of tocolysis must be seen not so much in a reduction of preterm labour but in enabling the obstetrician and neonatologist to optimise the handling of the premature baby, e.g. by allowing lung maturation or by enabling the patient to reach a centre for perinatal medicine before the birth. Labour-dependent fetal distress situations during birth at term can also be managed successfully. Supervision involves thorough control of both mother (especially of cardiovascular and metabolic parameters, electrolyte and water balance) and fetus (cardiotocography, fetometry) in order to decide individually when possible benefits are outweighed by maternal or fetal risks. Combination of beta 2-mimetic treatment with magnesium therapy reduces the beta-mimetic dosage required, has a cardioprotective action, and reduces the development of drug tolerance and the risk of lung oedema. This combination, therefore, should become routine in tocolytic therapy. If further protection against cardiovascular and risk of lung oedema is required, administration of beta 1-blockers is advisable.

Female↗

PubMedDate not supplied

[Evaluating the pregnant cervix uteri by ultrasound with computer-assisted texture analysis].

BACKGROUND: Cervical ripening during pregnancy is associated with ultrastructural alterations, presumably correlated with structural changes of the ultrasonographic image. Analysing these changes might allow conclusions on cervical consistence without necessarily performing manual examination. PATIENTS AND METHODS: Ultrasound findings of 112 patients with normal pregnancy (14th to 41st week of pregnancy) have been compared to those of 57 patients admitted because of cervical insufficiency (20th to 35th week). A representative region of interest was analysed using a computer based texture analysing system ("Ultra" written in "Interactive Data Language"). 125 parameters derive from various texture algorithms: 1st order gray scale statistics, row, slit and area statistics, gradient statistics, cooccurrence statistics. By means of factor and multiple regression analysis those parameters could be determined, which contribute significantly to the clinical assessment of cervical consistence. Weighting these parameters a so called texture score (TS) and--implementing the other parameters of the Bishop-Score (BS)--a texture based cervical score (TBCS) could be established. RESULTS: Manual assessment of cervical consistence could be reproduced excellently by noninvasive texture analysis. TBCS was highly correlated to BS, correlation to remaining duration of pregnancy (RDOP) was highly significant for TBCS but insignificant for BS. CONCLUSIONS: Manual assessment of cervical consistence may be replaced by noninvasive texture analysis. Using RDOP as target parameter TS and TBCS turn out to be superior to manual assessment and BS respectively. DISCUSSION: Computer aided texture analysis of cervical ultrasound imaging provides a useful information, which can be obtained easily and might help to reduce palpatory controls and increase the accuracy of prediction of pregnancy prolongation.

Adult↗

PubMedDate not supplied

[Does the "fatty pelvis" exist? Quantitative computer tomography studies].

50 Patients weighing between 45 and 114 kg underwent standardized computed tomography of the pelvis. Fat compartments from inside and outside of the small pelvis were assessed quantitatively by means of tracing the fat tissue borders and planimetry. Fat compartments within the small pelvis showed a rather weak correlation with body weight and the so called Rohrer-Index as a weight/height-Index, correlations with the latter being slightly better. From the fat compartments within the single levels the functional reduction of birth channel diameters caused by fat tissue was calculated for. The weight/height-index dependent increase of space demand within the birth channel was rather pronounced at the pelvic brim becoming slighter when reaching mid-pelvis or even pelvic outlet. Hence, the common assumption can no longer be maintained, that adiposity necessarily causes soft tissue dystokia due to larger fat compartments within the small pelvis.

Adipose Tissue↗

PubMedDate not supplied

[Changes in pelvic anatomy in 8 decades--computerized tomography study of obstetrically relevant pelvic measurements].

An increasing proportion of obstetric operative procedures due to cephalopelvic disproportion gave raise to the question, whether there has been a change in pelvic anatomy during the past decades. In a retrospective evaluation of 467 computerized pelvic tomograms of patients aged between 18 and 88 years relevant parameters of pelvic proportion were determined. As these parameters are not subject to age-conditioned changes, the values may be viewed as representative for the time of patients' birth or fertility period respectively. Changes in pelvic anatomy turned out to be complex: The transverse elliptic shape of pelvic inlet changed into sagittal elliptic form, the pelvic midplane is contracted progressively, sacral concavity is reduced. Obviously, this obstetrically adverse development is influenced by the fact, that unfavourable pelvic conformation can be transmitted more intensively by the generous indication for cesarean section. This development is contrasted by the circumstance of fetal acceleration. Therefore, an increase in cephalopelvic disproportion has to be expected. For the sake of a safe obstetrical management in these situations the generous use of ante partum pelvimetric diagnosis seems to be advisable.

Adolescent↗

PubMedDate not supplied

[Effect of co-medication with magnesium sulfate in beta-mimetic tocolysis on parameters of water-electrolyte balance].

With 2 groups of 10 patients the influence of an additional therapy with 1 g magnesium sulfate/h during i.v. tocolysis with the betamimetic fenoterol (2 micrograms/min) upon parameters of water and electrolyte balance has been investigated. The whole of the magnesium administered during the 24 hours investigational period has been eliminated via the kidneys. Most probably due to a competition within the distal tubulus hypermagnesemia was associated with hypocalcemia and hypercalciuria, followed by a rise in parathyroid hormone. As PTH is able to compensate hypocalcemia not only by means of bone mobilisation but also by an increase in enteral Ca absorption, estimated losses of calcium are minimal. These may be neglected, as additional therapy with magnesium sulfate--besides the advantages yet known (cardioprotection, saving of betamimetic dosage, reduction of drug tolerance development)--reduces betamimetic induced water retention, thus significantly diminishing lung edema hazard during tocolytic therapy.

Adult↗

PubMedDate not supplied

[Lung function during tocolysis with beta-stimulators and beta-1-blockers].

The pulmonary function during pregnancy is foremost changed by the elevated diaphragm, which reduces the functional residual capacity. The lungs are less extended, so that the airway resistance increases. The application of a beta-mimetic drug for tocolytic therapy could reduce the airway resistance. Because an additional selective beta-1-blocking drug for cardioprotection could interfere with this effect, the pulmonary function in pregnancy during tocolytic therapy was investigated by body plethysmography in 20 woman of the third trimester of gravidity. There were no apparent differences in the pulmonary function in these woman when an additional selective beta-1-receptor blockade was performed. The airway resistance even diminished during the beta blockade. This unexpected result is probably due to an stabilizing effect of the betablocker on the body fluid and the permeability of capillary membranes during tocolytic therapy.

Adrenergic beta-Agonists↗

PubMedDate not supplied

[New aspects of radiologic pelvimetry. Digital image intensification radiography: preliminary results of validation possibilities and results in various types of pelvic disproportion].

Within 1 year with 1325 births 54 cases necessitated operative obstetric intervention due to a disproportion between fetal head and maternal pelvis. In 40 cases radiologic pelvimetry was performed, using the conventional technique. 75% of cases turned out to be due to a midplane or outlet contraction. As, on the one hand, this type of pelvic disproportion seems to be of increasing importance, on the other hand generously adoperated radiologic diagnosis is not well accepted by the patients due to X-ray burden, Digital Image Intensifier Radiography (DIR) has been introduced for pelvimetry. X-ray burden amounts to only 5% of that of the conventional technique. Enhanced postprocessing and interactive measurement possibilities are further advantages of DIR. Using the appropriate softwear, interactive measurement results are characterized by the lack of mistakes due to X-ray divergence, if only the distance between measurement level and desk surface is known. By analyzing 30 computer tomograms measurement levels of the most important pelvic distances could be calculated in relation to the position of the anterior iliac spine. These relations show a very low interindividual variation. Thus, possible errors in measurement amount to a maximum of only 3.5%. The evaluation of our cases reveals the necessity to reassess the normal ranges for pelvic parameters, for the use of those deriving from conventional pelvimetry failed to describe correctly the anatomy of birth channel. For this sake, additional measurements, esp. of sacral and pelvic outlet anatomy have to be performed. Based upon these measurements, a computer aided modelling of the birth channel and a simulation of the birth could be achieved.(ABSTRACT TRUNCATED AT 250 WORDS)

Computer Simulation↗

PubMedDate not supplied

[Clenbuterol and fenoterol--animal experiment comparison of 2 tocolytic agents (with special reference to cardiovascular side effects)].

During animal experiments two substances, which are used for tocolysis (Fenoterol and Clenbuterol) have been compared regarding their tocolytic efficiency (determinations of myometrial cyclic AMP after long term treatment of the pregnant rat), their effects upon myocardial high energy phosphates (determinations of maternal myocardial high energy phosphates as well as of maternal and fetal myocardial cyclic AMP after long term treatment of the pregnant rat) and upon the hemodynamic situation (acute experiments with thoracotomized dogs). While significant hemodynamic derangements could be stated when using Fenoterol, no significant evidence for such alterations could be found during Clenbuterol administration during acute experiments. Determinations of myocardial high energy phosphates however reflected an augmented myocardial workload, both after Fenoterol and Clenbuterol administration. As by means of myometrial cyclic AMP determinations Clenbuterol proved to be at least as efficient as Fenoterol, concerning the tocolytic effect, Clenbuterol can be recommended as an oral tocolytic because of its pharmaco-cinetic advantages and the encouraging results from our hemodynamic investigations. According to results from chronical experiments an additional cardioprotection by means of magnesium substitution and eventually beta 1-blockade is still recommended.

Animals↗

PubMedDate not supplied

[Magnesium aspartate as a cardioprotective agent and adjuvant in tocolysis with betamimetics. Animal experiments on the kinetics and calcium antagonist action of orally administered magnesium aspartate with special reference to simultaneous vitamin B administration].

With pregnant Wistar-rats, suffering from alimentary magnesium deficiency, absorption and distributing of Mg28 has been studied, the latter having been applied as aspartate and as chloride, with and without simultaneous substitution of vitamin B6. Absorption and tissue pooling were found to be augmented when using the aspartate and even more when adding vitamin B6. These differences were significant in the blood as well as in fetal and myocardial tissue. Correlation between blood-Mg28 und Mg28-activities in various tissues shows, that blood magnesium levels indicate a magnesium deficiency at least in the tissues of interest: fetus, myocardium, uterus and placenta. Nevertheless blood magnesium levels fail to reflect an additional tissue pooling, that exerts a beneficial action in the respect of cardio protection and of saving beta-mimetic tocolytics. When measuring magnesium and calcium excretion during chronic experiments with and without oral magnesium aspartate substitution, it could be demonstrated, that the amount of substituted magnesium has been pooled almost totally. Oral magnesium substitution furthermore reduces intestinal calcium absorption. Investigation on calcium uptake into the maternal myocardium revealed, that oral magnesium aspartate substitution significantly diminishes myocardial calcium uptake, the latter among others being responsible for cardiac hazards during tocolysis with beta-mimetic substances, while the pharmacologic calcium-antagonist Verapamil failed to do so.

Animals↗

PubMedDate not supplied

[A knowledge-based system for the interpretation of pelvimetric findings].

Digital Image Intensifier Radiography (DIR) as well as Nuclear Magnetic Resonance Tomography (NMR) using an especially developed imaging routine for pelvimetry are suitable tools for the assessment of the anatomical conditions when mechanical problems are supposed to occur during birth (cephalopelvic disproportion, breech presentation). A concept for an optimised evaluation procedure of these imaging techniques has been developed, including: a more elaborate measuring protocol, easily and precisely executable due to appropriate software packages being implemented in the diagnostic units, calculation of obstetrically relevant parameters not deriving immediately from the imaging procedures. This is possible by means of multiple regression analysis of a data base from 467 evaluated female pelvis computed tomograms, calculation of intrapelvic soft tissue place requirements by means of correlative analysis of female computed tomograms and weight-/height-index, empirical determination of cut off values in borderline pelvi-fetometric constellations evaluating 190 births by means of logistic regression of the according pelvic-fetometric data. The calculations necessary to obtain all these parameters are implemented in a software package which also contains an algorithm for the general characterisation of an individual pelvis. Thus, a rather sophisticated knowledge base for pelvic assessment becomes easily accessible.

Adult↗

PubMedDate not supplied

[Quality of life of over 60-year-old patients with breast and uterine carcinoma, 5 years after primary operation].

In the 5-year follow-up period, we studied the quality of life of 145 patients who were at least 60 years old at the time of primary operation. Of the patients, 70 women had breast cancer and 75 endometrium cancer. We used the questionnaire "short form health survey: medical outcomes study". The areas which were analyzed were stress due to therapy, body image/femininity and social contacts. The Karnofsky-Index was determined by the physician. In both groups, most stress was felt due to the operation and at the first knowledge of the diagnosis. In the area of emotional stress 1/3 of the patients of both groups declared continuous stress due to feelings of fear, helplessness and passivity. In the area of body image/femininity half the patients with breast cancer and 2/3 with endometrial cancer felt stress. In the area of social contact 2/3 of the patients felt uncertainty in contact with others and this led to social retreat in 1/3 of the women. The Karnofsky-Index of all patients was between 50-100%. Our study supports the view that older patients with cancer should also be offered psychosocial counseling.

Activities of Daily Living↗