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Biomedical subjects

W Künzel

Publications and source records attributed to W Künzel.

At least 19 recordsLinked to original sources
PubMed1992

Blood flow velocity in the fetal abdominal aorta and in the umbilical artery in uncomplicated pregnancies.

The blood flow velocity waveform (BFWV) in fetal vessels depends on the stroke volume and the frequency of the fetal heart, the compliance of the vessel and the peripheral resistance of the fetal vascular bed. The objective of the present study was to establish the change of the BFVW throughout gestation and whether the change of the resistance indices are related to the peak flow velocity and/or the end-diastolic flow velocity. The BFVW of the fetal abdominal aorta and of the umbilical artery at 27th-30th week and at 37th-40th week of gestation were analysed in fifteen patients with uncomplicated pregnancies and subsequent normal outcome. The measurement was performed with a pulsed duplex scanner (Kranzbühler). The Doppler beam had a fixed angle of 50 degrees to the fetal vessel in all cases. The peak flow velocity in the fetal aorta remained constant from the 27th-30th week to the 37th-40th week of gestation: 1418 +/- 248 Hz vs. 1448 +/- 269 Hz. The end-diastolic flow, however, showed a significant increase during the respective periods: from 270 +/- 59 Hz to 325 +/- 69 Hz. The peak flow velocity in the umbilical artery was about 25% below that of the fetal aorta: 1028 +/- 149 Hz (27th-30th week) and 1106 +/- 196 Hz (37th-40th week). The end-diastolic flow, however, increased by about 41%: 292 +/- 86 Hz vs. 412 +/- 83 Hz demonstrating a tremendous change of the compliance and the peripheral resistance in the umbilical vascular system. These alterations are also exhibited by the resistance indices. The resistance indices S/D, PI and RI of both vessels were related to the EDF of the abdominal aorta and the umbilical artery at the respective gestational age. It demonstrated that the EDF is of major influence on the calculated resistance indices. The blood flow in the aorta and the umbilical artery was 135(+/- 18) ml/kg/min and 143 (+/- 21) ml/kg/min, respectively. In conclusion, the BFVW for fetal surveillance should be measured under a constant angle in the fetal abdominal aorta. It gives a good information concerning the peripheral resistance and compliance in the respective vascular areas. The EDFV has its lowest value at 200 Hz in the fetal aorta and in the umbilical artery under physiological conditions.

Aorta, Abdominal↗
PubMed1992

Oxygen tension in follicular fluid falls with follicle maturation.

The increase in follicular diameter during maturation is accompanied by an increase in vascular supply. The oxygen tension (PO2) in the follicular fluid of the growing follicle should therefore give an insight whether the oxygen delivery during this pertinent process is sufficient. Follicular fluid of 20 patients subjected to in vitro fertilization and embryo transfer were sampled in heparinized glass capillaries which were placed between the puncturing needle and the collecting reservoir. All patients were treated with human menopausal gonadotropin (HMG) and follicle-stimulating hormone (FSH). The PO2, PCO2 and pH of the follicular fluid were measured with an automatic gas analyser (Ciba Corning). Simultaneously, the same parameters were estimated in maternal capillary blood taken from the arterialized well perfused earlobe. Follicular size was measured by ultrasound. With growing follicular size (FS), the oxygen partial pressure (PO2) fell from 80 to 50-60 mmHg (PO2 = 114.4-3.3.FS; r = 0.79) while the carbondioxide partial pressure (PCO2) in the follicle increased from 35 to 50 mmHg (PCO2 = 15.1 +/- 1.9.FS; r = 0.71). In correlation to these results, the pH in follicular fluid fell from 7.40 to 7.30 (pH = 7.6-0.019.FS; r = 0.62). The correlation between the PCO2 and the pH demonstrates a deviation from the regression line if no metabolic alterations take place (delta log PCO2/delta pH = -0.69). The increase in ovarian blood flow during follicular maturation is obviously not sufficient to bridge the growing diffusion distance between the capillary network surrounding the follicle and its center.(ABSTRACT TRUNCATED AT 250 WORDS)

Carbon Dioxide↗
PubMed1992

Dihydroergotamine causes fetal growth retardation in guinea pigs.

Dihydroergotamine is a vasoactive drug which enhances venous tone, central blood volume and cardiac output but has variable effects on arterial tone. Its effect on the uterine arterial circulation is unstudied and yet dihydroergotamine is widely used to treat postural hypotension in pregnant and nonpregnant women. For this reason we undertook studies to determine if its chronic use had any adverse effect on the placental arterial circulation and fetal growth in an animal model. We administered dihydroergotamine (14 micrograms/kg/day) to pregnant guinea pigs with 2-4 fetuses from day 30-60 of pregnancy. At term under light ketamine anaesthesia, we measured maternal arterial blood pressure and blood flow to myometrium, placenta, skin and skeletal muscle using left ventricular injection and standard sampling techniques. Vascular resistance was calculated from arterial blood pressure and blood flow. When controlled for litter size, both fetal weight and the fetal weight/placental weight ratio were significantly less (P less than 0.001) in the dihydroergotamine group (-21% and -11% respectively). Placental blood flow was decreased by 51% (P less than 0.01) whereas myometrial blood flow, skin blood flow and muscle blood flow were not significantly altered. There was no significant difference in mean arterial blood pressure but placental vascular resistance was increased (+45%, P less than 0.05) while it was unchanged in myometrium and skin and decreased in skeletal muscle (-51%, P less than 0.05). Chronic administration of dihydroergotamine at a clinical dosage level has a constrictive effect on the placental vasculature of guinea pigs with a subsequent adverse effect on flow and fetal growth.

Abnormalities, Drug-Induced↗
PubMed1992

[Risk of cerebral hemorrhage in premature and mature newborn infants].

We launched a prospective cranial ultrasound screening study at the Maternity Hospital of the University of Giessen to examine the incidence and severity of brain damage in newborns. More than 90% of all neonates born during 1984-86 were included in the study (n = 2781) and were screened for cerebral abnormalities on 5.9 +/- 3.3 (SD) day post partum. There were in 7.8% sonographic abnormalities, the most frequent being peri/intraventricular haemorrhages (5.2% PIVH of various degrees (grade I-III). Periventricular leucomalacia, porencephalia, subarachnoidal haemorrhages, and hydrocephali were rare (less than or equal to 0.2%). The incidence of PIVH increased progressively with decreasing gestational age, e.g. from 1.5% at 41 weeks up to 61% at 24-30 weeks of gestation. A large percentage of babies with cerebral haemorrhages were clinically normal. There was a close inverse relationship between the Apgar score at 1,5 and 10 min and both incidence and severity of PIVH. However, the relation between PIVH and both cardiotocography (matched-pairs analysis) and arterial cord blood-pH was poor. The incidence of PIVH was increased in growth retarded newborns (pH less than or equal to 7.29), preterm multiples and amnionitis, but not after preeclampsia and premature rupture of membranes. It is interesting to note that, in mature newborns (greater than or equal to 38 weeks), there was no difference in the incidence of PIVH between spontaneous deliveries, vacuum extractions, and Caesarean sections, and that there was no difference between vaginally delivered (1.5%) and sectioned breech presentations (3.5%) in this group. In preterms at 35-37 weeks with protracted labour and secondary Caesarean section, the incidence of PIVH was high (19%). We conclude, that neonatal cranial ultrasound screening is an important tool for risk assessment and quality control in obstetrics. It clearly improves both the quality of the advice given to the patients and the clinical management of high-risk pregnancies.

Acid-Base Equilibrium↗
PubMed1992

[The value of prepartal ultrasound estimation of birth weight in breech presentation].

Biometric data, i.e. the biparietal (BPD) and fronto-occipital diameter (FOD) of the skull as well as the transverse (TTD) and the longitudinal trunk diameter (LTD) were obtained in 127 cases of breech and 95 cases of vertex presentations within one week before birth. These data were compared with the birth weight measured postpartally. From these data, an optimized equation was derived for both breech and vertex presentations and compared to the equation known from the literature. The optimized equation for breech presentations requires only the biometric data of the trunk (TTD and LTD). In spite of this optimization, the quality of the foetal weight estimation of breech presentations seems to be more inaccurate in comparison to the estimation of vertex presentations. Concerning the obstetrical management the foetal weight estimation by ultrasound has to be evaluated more critically for breech presentations than for vertex presentations.

Birth Weight↗
PubMed1992

Cardiac function, morphology and chromosomal aberrations in a calf with ectopia cordis cervicalis.

A male calf with ectopia cordis cervicalis inferior was investigated clinically, hemodynamically, and morphologically from the 3rd day of age until slaughter at the age of 22 months. Arterial hypertension (mean AOP 140 mm Hg), concentric myocardial hypertrophy and good ventricular contractility with normal valve function were found. Normal clinical condition at rest (cardiac output 48 l/min in the 600 kg bullock), but cyanosis and dyspnea during physical exercise were observed. Variations in the large vessels, such as persistence of the right cranial caval vein and one common pulmonary vein emptying into the left atrium, were found. Abrupt caliber differences of large arterial vessels together with a right angled aortic arch were observed, presumably contributing to increased afterload. The cytogenetic analysis showed the presence of a small marker chromosome leading to a chromosome number of 61 in a fraction of metaphases (mosaicism). Moreover, chromosome breakages were observed in many cells. From the 5 cows which were inseminated, 3 became pregnant. Ectopia cordis was not observed in any offspring. We conclude that in this animal compensated cardiac insufficiency with peripheral hypertension was established.

Animals↗
PubMed1992

[The distribution of mutans streptococci and lactobacilli depending on the caries prevalence in 11- to 12-year-old children].

20 Korean children, aged 11 to 12 years, participated in this study with the aim to compare the microbial composition of plaque samples in order to estimate, which genera (lactobacilli, streptococci) or species are associated with coronal caries. Significant differences in the microbial composition of plaque samples between children with healthy and carious dentitions were found. S. mutans (c, e, f) was dominating under Mutans-streptococci.

Child↗
PubMed1991

Orthostatic hypotension and birthweight.

This study was designed to test two hypotheses. First, that the changes in arterial blood pressure, induced by a transition from a lying to a standing position, are different in early and late pregnancy. Second, that birthweight is related to the change in mean arterial blood pressure in late pregnancy such that those patients whose pressure fell on standing should have the lightest babies. Fifty-three patients were studied between the 12th to 18th week, and 41 women were between the 34th to 40th week of an accurately dated, clinically normal, singleton pregnancy. Twelve nulliparous females served as controls. Blood pressure and heart rate were measured at rest, then in the standing position and finally at rest again with a Dinamap blood pressure measuring device. The variability in the pressor response to standing was approximately three times and in heart rate response two times greater in early pregnancy and in late pregnancy, when compared to the nonpregnant controls. It should be further noted that only in late pregnancy did the heart rate fall in 10 out of 41 women on standing. A linear relationship was observed in late pregnancy between the change in mean arterial blood pressure and birthweight (r = 0.57, P less than 0.001). This linear relationship was improved to r = 0.86, when only those women (16/41), who either had a rise or fall in systolic blood pressure of more than 5 mm Hg were included. These data indicate that pregnancy increases the variability in the pressor response to standing. Moreover, birthweight was directly related to the magnitude and direction of the pressor response in late pregnancy. Finally, this relationship suggests an additional cause for unexplained cases of intrauterine growth retardation.

Adult↗
PubMed1991

[Fetal methemoglobinemia caused by prilocaine--is use of prilocaine for pudendal block still justified?].

17 women received 2 x 10 ml prilocaine 1% as a pudendal block sub partu. At delivery, the foetomaternal distribution ratio of the local anaesthetic was evaluated and the development of Met-Hb-concentration in the neonate was measured up to six hours post partum. The Met-Hb-concentration in the neonate was relatively low with a maximum of 1.8% after two hours, followed by a steady decline. A probable explanation for the Met-Hb-concentration could be the unexpected low foetomaternal ratio of distribution (0.5) and the increased renal elimination of the amide-type local anaesthetic in the neonate, respectively. According to these results, no contraindication for prilocaine in pudendal block is indicated.

Administration, Intravaginal↗
PubMed1991

[Blood flow in the umbilical vein and artery in pregnancy].

Transplacental gas exchange and supply of nutritive substances to the foetus is guaranteed by an increase of umbilical blood flow (Qnv). It was investigated, whether the umbilical blood flow (Qnv) is influenced by physiological conditions during pregnancy and if changes occur in the umbilical blood flow velocity wave forms. In this study, 31 pregnant women between the 24th to 40th week of gestation were examined with a pulsed wave duplex scanner ADR Kranzbühler 8150. The mean flow velocity (Vnv) of the umbilical vein and the diameter of the vessel were parameters, which were included in the calculation of the umbilical blood flow. The flow profile of the umbilical artery allowed determination of the maximum systolic frequency (Fmax) and the end-diastolic frequency (Fmin). Based on these data, three indices--RI, PI, S/D ratio were calculated. The blood flow of the umbilical vein (Qnv) shows a linear increase up to the 36th week of gestation and remains at this level thereafter. The increase of umbilical blood flow (Qnv) is mainly caused by an increase of the diameter of the umbilical vein (81%, 26th-40th week of gestation) and to a lesser degree by an increase of the mean flow velocity (Vnv) (18%, 26th-40th week of gestation). The diameter of the vein is highly correlated both with the foetal birth weight (r = 0.60) and the umbilical blood flow (Qnv) (r = 0.73). Throughout pregnancy, flow velocity waveforms showed significant changes of the maximum systolic frequency (Fmax) from 973 Hz (SD 128 Hz; 26th week of gestation) to 1130 Hz (SD 152 Hz; 40th week of gestation) and an increase of the end-diastolic frequency (Fmin) from 246 Hz (SD 58 Hz; 26th week of gestation) to 423 Hz (SD 91 Hz; 40th week of gestation). The higher increase of the end-diastolic frequency (Fmin) results in a decrease of the resistance index (RI), pulsatility index (PI) and SD-ratio. None of the investigated cases showed an end-diastolic frequency (Fmin) of less than 200 Hz. These results reveal, that determination of the blood flow of the umbilical vein mainly depends on measuring the diameter of the vessel rather than on measurements of the blood flow velocity (Qnv) of the vein. With the presently available equipment, accurate measurements of the diameter are very difficult. The increase of blood flow of the umbilical vein is not proportional to the foetal growth; moreover, it remains constant from the 36th week of gestation.(ABSTRACT TRUNCATED AT 400 WORDS)

Blood Flow Velocity↗
PubMed1991

[Salpingoscopy--an aid in the diagnosis of sterility].

The condition of the fallopian tubes was assessed in 100 fertile women on whom a caesarean section had been performed and in 100 infertile women who had undergone a diagnostic laparascopy. The 100 infertile women revealed both peritubal adhesions (20% vs 2%) and fimbrial agglutinations (4% vs 0%) in a significantly higher number of cases. When the diagnostic procedure was extended to include the salpingoscopy of 20 women with periampullary and peritubal adhesions, 10% of them were found to be suffering from damage of the endosalphinx. In patients with fimbrial agglutination, the same diagnostic procedure revealed mucosal damage in 40% of the cases. The rate of damage to the endosalpinx may help to explain the relatively high rate of ectopic pregnancies (15%) following microsurgical fimbrioplasty. Thus, in cases where the patient is suffering from peritubal adhesions and fimbrial agglutinations, salpinogoscopy can be of use in deciding whether microsurgery is indicated. In those cases, where there is evidence of damage to the endosalpinx, in-vitro fertilization with intrauterine embryo transfer must be considered as the preferential method.

Adult↗