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Biomedical subjects

H J Seewald

Publications and source records attributed to H J Seewald.

At least 19 recordsLinked to original sources
PubMed2001

The application of fetal magnetocardiography (FMCG) to investigate fetal arrhythmias and congenital heart defects (CHD).

OBJECTIVES: Fetal magnetocardiography (FMCG), a new non-invasive diagnostic tool in the analysis of the electrophysiological changes of the heart, was selectively applied in cases of fetal arrhythmias and congenital heart defect (CHD) to demonstrate its value for diagnosis and prenatal management. METHODS: The FMCG was analysed and compared to the postnatal ECG in four cases of fetal arrhythmia [supraventricular tachycardia (two cases), complex tachy-/bradycardia (one case), ventricular extrasystoles (one case)] and a case of right heart hypoplasia diagnosed by established methods prior to investigation. RESULTS: A Wolf-Parkinson-White (WPW) syndrome was diagnosed by its characteristic features and the appropriate transplacental therapy chosen. The types of arrhythmia could be characterised in accordance with postnatal ECG findings and irregular conduction was demonstrated in association with a CHD. CONCLUSIONS: The use of the FMCG provides additional information to the common diagnostic tools that influence therapeutic decisions and thus contributes to optimal pre- and postnatal management.

Adult↗
PubMed2001

[The extralobar sequestration of the fetal lung].

The extralobar sequestration is a rare pulmonary malformation. An accurate antenatal evaluation is required for a timely therapy and subsequently a good outcome. Here an unusual case of extralobar pulmonary sequestration in a male human fetus is reported. Antenatal ultrasound at 28th week of gestation has revealed a fetal hydrothorax in coexistence with pulmonary hypoplasia and an isolated pulmonary structure. Authors summarise their postnatal findings with special reference to the pathogenesis of an accessory lung. The aim of this report is to define the association of clinical, gross, and histological features of this rare congential malformation in order to improve the antenatal diagnosis. This case indicates that an extralobar pulmonary sequester is not connected to the tracheobronchial tree, and that the arterial as well as the venous blood supply is realised by aberrant systemic vessels. Moreover, histologically revealed dilatations of the normally differentiated terminal airways within the sequester suggest that hyperechogenity can not be a reliable diagnostic criterion. For the accurate assessment of a pulmonary sequestration a detailed antenatal evaluation of both, the arterial and the venous blood supply is essential.

Adult↗
PubMed2001

Signal analysis of auditory evoked cortical fields in fetal magnetoencephalography.

Magnetoencephalography (MEG) using auditory evoked cortical fields (AEF) is an absolutely non-invasive method of passive measurement which utilizes magnetic fields caused by specific cortical activity. By applying the exceptionally sensitive SQUID technology to record these fields of dipolar configuration produced by the fetal brain, MEG as an investigational tool could provide new insights into the development of the human brain in utero. The major constraint to this application is a very low signal-to-noise ratio (SNR) that has to be attributed to a variety of factors including the magnetic signals generated by the fetal and maternal hearts which inevitably obscure a straightforward signal analysis. By applying a new algorithm of specific heart artefact reduction based on the relative regularity of the heart signals, we were able to increase the chance of extracting a fetal AEF from the raw data by the means of averaging techniques and principle component analysis. Results from 27 pregnant, healthy women (third trimester of their uncomplicated pregnancy) indicate an improved detection rate and the reproducibility of the fetal MEG. We evaluate and discuss a-priori criteria for signal analyses which will enable us to systematically analyze additional limiting factors, to further enhance the efficiency of this method and to promote the assessment of its possible clinical value in the future.

Acoustic Stimulation↗
PubMed2001

Fetal magnetoencephalography: a non-invasive method for the assessment of fetal neuronal maturation.

OBJECTIVE: To assess the maturation of auditory evoked cortical responses in the human fetus using fetal magnetoencephalography. DESIGN: Prospective case series over a three-year period. SETTING: Antenatal clinics, university hospital. POPULATION: Singleton pregnancies at 29-40 weeks of gestation. METHODS: We used a 31-channel-SQUID-biomagnetometer in a magnetically-shielded room to perform fetal magnetoencephalography. To record auditory evoked fields from the fetal brain we applied 500 monotonal bursts generated by a computerised sound generator directly to the maternal abdominal wall near the fetal head. The continuously recorded data sets were analysed stepwise using a specially developed heart artefact rejection software, Fourier filtering, principle component analysis and half split analysis of the averaged data. RESULTS: In 36 of 64 examinations we detected signals of auditory evoked fields comparable to the P2m component in adults. The earliest recording succeeded in the 29th gestational week. The latencies of the auditory evoked responses declined during the third trimester from 300 ms to nearly 150 ms at term. The maturation of different components of the auditory evoked field could be demonstrated from the 31st gestational week onwards. CONCLUSION: The maturation of a fetal auditory cortical function using fetal magnetoencephalography could be assessed directly for the first time. We believe that this method will add information to current indirect methods of assessing the normal maturation of the human fetal brain.

Brain↗
PubMed1997

[Levels of antioxidants after cesarean section and administration of Multibionta N, Inzolen and selenase].

PATIENTS AND METHOD: In 29 women with the necessity to terminate pregnancy via Cesarean section, lipid peroxidation and antioxidative state were investigated before and 24 hours after the surgical intervention as well as after substitution of antioxidants and trace elements. RESULTS: The results indicate that administration of antioxidants protects at least partially from consequences of surgically induced oxidative burden.

Antioxidants↗
PubMed1994

Insulin-like growth factor I correlations to changes of the hormonal status in puberty and age.

IGF-I is considered to be one of the most important growth factors during puberty. Information concerning its correlation to thyroid hormones (T3, T4), adrenal and sex steroids is limited to puberty and the elderly. The presented study included 455 subjects (among them 259 children) ranging in age from newborn to 100 years. Serum IGF-I concentrations increase from childhood to the end of puberty (2 years earlier in girls). There are close positive correlations between IGF-I concentrations and age, height and weight and between IGF-I and estradiol or testosterone concentration in girls and boys respectively, and the DHEA-S level in boys during puberty. Correlations also exist with T3, aldosterone and 17 OH-progesterone in boys and girls in the pubertal stages I-V and with T4 in stages I-IV. Compared to 20-30 year-old subjects IGF-I concentrations amounted to 59% after 60 years, 43% in men and 54% in women after 70 years and 29% after 90 years. It is suggested that increasing adrenal DHEA-S concentrations stimulate IGF-I synthesis and by means of gonadal steroidogenesis, increase the pubertal GH secretion and the further pubertal IGF-I increase. The low IGF-I concentrations in patients > 60 years reflect the more catabolic metabolism of the elderly.

Adolescent↗
PubMed1991

[Fetal movement and acceleration behavior in hypertension in pregnancy].

Under standardized conditions, 26 pregnant women with pregnancy-related hypertension of different degrees were submitted to cardiogram-synchronous recording of fetal body and respiratory movements. The gestational age was between the completed 34th and 38th weeks. Of the 26 fetuses of the risk group, 20 were normotrophic and 6 hypotrophic. 40 normotrophic unimpaired fetuses of the same gestational age served as a control group. The average duration of the examination period was 70 minutes. The fetal movement and acceleration behaviours did not differ between the normotrophic fetuses of the risk group and those of the control group. The hypotrophic fetuses from the risk group, however, had significantly lower fetal body and respiratory activities than the normotrophic fetuses from this group. The same holds true for the degrees of heart rate activity. It can be concluded that pregnancy-related hypertension as the only pregnancy complication does not have a measurable influence on fetal movement and acceleration behaviours. This is true for both treated and untreated pregnancy-related hypertensions. The severity of pregnancy-related hypertension is not primarily reflected in changes of fetal movement and acceleration behaviours, either. This means that the parameters presented are not suited to prognosticate the effects of pregnancy-related hypertension on the fetus a priori. The situation becomes quite different if in addition to pregnancy-related hypertension some intrauterine fetal growth retardation develops. In this case, the fetus indicates its impairment by increasingly impaired movement and heart rate activities as a consequence of chronic oxygen deficiency.

Female↗
PubMed1989

[The extent of fetal heart rate accelerations associated with fetal body movements in relation to the duration of fetal body movement].

The temporal relations between fetal body movements and associated fetal heart rate accelerations were shown as the ratios of duration of acceleration or acceleration amplitude and the duration of associated fetal body movements in 44 normotrophic and 40 hypotrophic fetuses (body weights within the 6th to 10th percentiles, n = 19, and less than or equal to the 5th percentile, n = 21) between the 36th and 40th gestational weeks. Related to the duration of associated fetal body movements, hypotrophic fetuses proved to have gradually smaller heart rate accelerations than normotrophic fetuses. Moreover, the acceleration parameters duration and amplitude were dependent on the relative duration of fetal body movements. Short fetal body movements were accompanied by fetal heart rate accelerations of relatively highest degree and vice versa. As a consequence, no comparison is possible between temporally different fetal body movements and their associated heart rate accelerations. Of the two acceleration parameters duration and amplitude, the inclusion of the accelerations amplitude in the above mentioned ratio yielded the most obvious results. Taking into consideration that fetuses with intrauterine growth retardation are often in a state of chronic hypoxia, the ratios of acceleration amplitude and durations of associated fetal body movements indicated different degrees of this metabolic situation.

Adult↗
PubMed1989

[Movement and heart acceleration behavior of eutrophic fetuses in the early and late dilatation period].

The degree of fetal respiratory and body movements as well as of fetal heart rate reactivity was checked by synchronous ultrasonic and cardiographic monitoring of 18 normotrophic fetuses in the early and late dilation period. Apart from the fetal respiratory movements, which could no longer be observed in the late dilatation period, the degree of fetal body movements remained unaffected during the birth process. In the late dilatation period, the mean amplitude of heart rate accelerations occurring in association with fetal body movements was significantly lower than in the early dilatation period. In the unimpaired normotrophic fetus, however, the reactivity of the fetal cardiovascular system increased during the birth process in relation to the ratio of the amplitude of heart rate accelerations and the duration of associated fetal body movements. Hence, a decrease in fetal heart rate reactivity signals intranatal disturbance of the materno-utero-placento-fetal entity.

Cardiotocography↗
PubMed1989

[Synchronous cardiotocographic registration of fetal body and respiratory movements in placenta insufficiency].

The extent of fetal movements and their reflections in the cardiogramme were studied in 44 normotrophic and 39 hypotrophic fetuses under standardized conditions using real time ultrasound examination of fetal body and respiratory movements and synchronous registration of fetal cardiogrammes from a uterus without labour. Altogether, hypotrophic fetuses exhibited fewer movements than normotrophic fetuses did. Numbers and parameters of accelerations in fetal heart rate occurring in connection with fetal body movements were less marked, too. The acceleration amplitude was particularly significant. Further comparisons between fetuses born with pHa greater than or equal to 7.20 and less than 7.20 or 1- and 5-minute Apgar scores greater than or equal to 8 points and less than or equal to 7 points revealed statistically significant (alpha = 0.05) differences in the frequency of movements and movement-associated accelerations in fetal heart rate only in fetuses with a body weight less than or equal to the 5th weight percentile according to Kyank (n = 21). Fetuses with a body weight between the 6th and the 10th weight percentiles (n = 18) and normotrophic fetuses did not, or did only faintly, reveal these differences. A ratio calculated from the acceleration amplitudes and the durations of associated body movements differed significantly between impaired and unimpaired born fetuses during defined intervals of the duration of fetal body movements.

Acid-Base Equilibrium↗
PubMed1989

[HLA compatibility and susceptibility to habitual abortion. Results of histocompatibility testing of couples with frequent miscarriages].

We have performed class I HLA antigen testing in 42 women with recurrent habitual abortions and in their husbands. The main criterion for inclusion in this group was a frequency of more than two abortions without the known reasons for abortion and without a living child. 29 couples with a least two healthy children and no abortion in the clinical history served as a control group. The data were evaluated in respect to the association of HLA and disease as well as to the level of histocompatibility within the couples. In our results we did not find any significant association between HLA-A, B, C phenotypes and the habitual abortion. On the other hand, we observed a significantly higher level of histocompatibility in the couples with habitual abortions in comparison to the control couples. The frequency of identity in one and more histocompatibility antigens was in the patient group significantly higher than in the control group and as it could be expected by chance, calculated on the basis of antigen distribution within the loci A, B, C in the population in the southern part of the GDR. In no case we have revealed lymphocytotoxic antibodies as a possible cause for miscarriage. Our results are in favour of the hypothesis that a higher level of histocompatibility could be an immunological explanation for the habitual abortions. In addition, this hypothesis was supported by the successful immunotherapy with leukocytes derived from the husband or nonrelative donors.

Abortion, Habitual↗
PubMed1989

[Description of cardiogram potentials of fetal movements in labor].

Examples of cardiographic reflections of intranatal fetal movements (body movements) in 130 normotrophic and 26 hypotrophic fetuses (body weight less than or equal to 10th percentile) are presented. Labour-synchronous accelerations of fetal heart rate occurred in 95% associated with fetal body movements. About 83% of the body movements associated with fetal heart rate accelerations occurred periodically. Strikingly, labour with fetal body movements resulted in accelerations, whereas labour alone hardly ever produced medium-term heart rate changes or variable decelerations. In contrast to periodical accelerations with associated body movements, periodical accelerations without associated fetal body movements, which are mainly of hemodynamic origin, indicated potential fetal risk. Even with medium-degree or severe variable decelerations in the expulsive period, fetal body movements with associated heart rate accelerations indicated a good actual fetal condition. The importance of cardiogram synchronous real-time ultrasonic examination of intranatal fetal movements is discussed.

Cardiotocography↗
PubMed1989

[Qualitative description of cardiogram potentials of fetal body and respiratory movements in the non-contracting uterus].

Cardiographic reflections of fetal movements were assessed using cardiogram synchronous ultrasonic examination in 44 normotrophic and 40 hypotrophic fetuses with body weights less than or equal to 10th percentile. The study showed that 90% of the fetal body movements were associated with accelerations in fetal heart rate. The degree of associated accelerations depended on the duration of the fetal body movements. In the hypotrophic fetuses the associated heart rate accelerations had a lower amplitude and a relatively longer duration. In impaired fetuses body movements were associated with decelerations in heart rate. Fetal respiratory movements resulted in an increasing beat-to-beat variability in the CTG. This effect did not occur constantly. During prolonged fetal respiratory segments no fetal body movements were observed and vice versa. Possible causes for the association between fetal movements and cardiogram are discussed.

Cardiotocography↗
PubMed1988

[Fetal heart rate accelerations and fetal oxygen pressure sub partu].

By means of tcPO2 measurement, a total of 297 FHR accelerations from 55 oxygen cardiotocograms were analysed with regard to their association with changes in fetal oxygen pressure sub partu. It could be demonstrated that the transcutaneous oxygen pressure of 2.3 kPa (17.1 mmHg) with occasional accelerations was significantly (alpha less than 0.05) higher than that of 2.2 kPa (16.6 mmHg) with periodic accelerations. Oxygen pressure with occasional accelerations with "classical parameters" (amplitude greater than or equal to 15 bpm, duration greater than or equal to 15 sec) did not significantly differ from that with one or both parameters below these minimal values. Furthermore, our results suggest the production of periodic accelerations by pressorreceptor reflex due to intermittent disturbance in umbilico-placental perfusion.

Blood Gas Monitoring, Transcutaneous↗
PubMed1988

[Critical evaluation of various methods of determining markers of fetal maturity in amniotic fluid].

11 methods for investigation of fetal lung maturity, fetal skin maturity and common maturity signs were described. All investigations have been carried out on the base of 61 amniotic fluid samples. A certain declaration of fetal lung maturity is possible by: 1. The absorbance of native amniotic fluid at 650 nm 2. Shake-test (Clements) 3. Average quantities of the keratinocytes of the amniotic fluid cell population. Good results, a small amniotic fluid quantity and a simple procedure characterise these methods. They are usefull in clinical practice.

Amniotic Fluid↗