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C Bast

Publications and source records attributed to C Bast.

6 recordsLinked to original sources
PubMed1998

Doppler echocardiography of the main stems of the pulmonary arteries in the normal human fetus.

The objective of this study was to describe the normal blood flow velocity waveforms in the main branches of the right and left pulmonary arteries in the human fetus and to establish reference ranges for different Doppler parameters during the second half of pregnancy. Cross-sectional data were collected from 86 healthy human singleton fetuses between 18 and 38 weeks of gestation. With advancing gestation a significant increase (p < 0.001) in the peak systolic velocity, time averaged velocity and time velocity integral was observed. The pulsatility index decreased significantly (p < 0.05) in the same period, suggesting a decrease in the pulmonary arterial vascular resistance. The acceleration time (AT) and the ratio of AT to ejection time (AT/ET), described in postnatal cardiology as having an inverse correlation with mean arterial pressure, increased significantly (p < 0.001). This is possibly the result of decreased pulmonary arterial pressure. The data show that Doppler examination of blood flow in the main stem of both the right and the left pulmonary arteries of the fetus is feasible, and increases insight into the lung perfusion of the human fetus. The observed changes throughout gestation are in accordance with animal experiments showing an increase in perfusion as well as a decrease in the vascular resistance and pressure.

Blood Flow Velocity↗
PubMed1997

[Doppler examination of the fetal left and right pulmonary artery. Relation to fetal position and gestational age: a methodological study].

UNLABELLED: A Methodical Study: AIM OF THE STUDY: To analyse the feasibility of colour and spectral Doppler assessment of blood flow in the fetal right (RPA) and left (LPA) main pulmonary arteries in relation to fetal position and to gestational age. STUDY DESIGN: The fetal position was a priori divided into 3 types, depending on whether the fetal heart was visualised apically (Type 1), from the right side (Type 2) or from the left side (Type 3). Three groups A (19-25 weeks gestation), B (26-32) and C (33-39) including 33 consecutive pregnancies each, were examined to document the fetal position as well as the rate of the successful Doppler examinations of the RPA and/or LPA. RESULTS: The fetal position Type 2 was most common throughout gestation (in group A = 42%, B = 36%, C = 51%) followed by the type 3 and then type 1. The rate of successful Doppler records from the RPA and LPA depended on the fetal position: In Type 2 RPA in 98%; in Type 3, LPA in 100%; but the apical approach was not effective (< 40%). Depending on gestational age, the success rates for a Doppler examination of at least one vessel were high (> 85%), whereas successful examination of both vessels was unlikely (12%). CONCLUSIONS: In the second half of pregnancy, independent of fetal position, Doppler examination of at least one pulmonary artery is successful in most cases, whereas the assessment of both vessels is rather difficult.

Female↗
PubMed1994

Immunogenicity of a viral model vaccine after different inactivation procedures.

Various strategies for the production of safe vaccines have been used. This study compared three different inactivation procedures, i.e. treatment with formaldehyde, beta-propiolactone or UV-light using vesicular stomatitis virus (VSV) as a model antigen. All three inactivation procedures drastically impaired induction of neutralizing IgG responses, confirming previous observations [Bachmann et al. (1993) J Virol 67:3917-3922]. This reduction could be overcome using higher doses for all three preparations. Both formaldehyde and beta-propiolactone completely abrogated the induction of VSV-specific cytotoxic T cells (CTLs), whereas UV-inactivated virus was able to induce significant and long-lasting CTL responses. These results may be of practical relevance since induction of neutralizing antibodies alone is often not sufficient for protection and sometimes may even enhance immunopathological responses of vaccinees.

Animals↗