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Biomedical subjects

W Künzel

Publications and source records attributed to W Künzel.

At least 235 records · Page 13Linked to original sources
PubMed1980

The difference between fetal transcutaneous pO2 and arterial pO2 during labour.

Sub partu measurements of the transcutaneous pO2 (tcpO2), the relative local skin perfusion, the fetal heart rate, and the amniotic fluid pressure were carried out with commercial equipment on 40 pregnant women at term. In 19 cases (47.5%), the tcpO2 could be monitored until the fetal head was delivered. The relationship between the tcpO2 and the arterialised capillary scalp blood was investigated in 20 patients on 42 micro-blood samples. Changes of the fetal heart rate pattern were analysed by means of a cardiotocogram scoring system with regard to its influence on the tcpO2 values. Two main groups of tcpO2 measurements could be differentiated. In 9 of 19 cases the tcpO2 remained stable over a prolonged period and decreased only during the final phase of birth to values between 6 and 18 mm Hg. In 10 of 19 cases the tcpO2 values began to decline to low levels in the course of labour as early as 90 min ante partum and reached values of 0-3 mm Hg at birth. In 9 of these 10 cases a tcpO2 'zero line' could be monitored in the last 2-90 min prior to birth. The tcpO2 did not correlate to either the pO2 of the arterialised fetal scalp blood or to the pO2 of the umbilical artery blood. Even with a tcpO2 of approximately 0 mm Hg, an arterial pO2 of 14.5-22.5 mm Hg in the scalp blood and of 10-20 mm Hg in the umbilical artery blood could be determined. In most of the cases a difference between the tcpO2 and the arterial pO2 developed.

Apgar Score↗
PubMed1980

Cardiovascular, metabolic and fetal brain function observation following total cord occlusion.

The effect of total cord occlusion (TCO) on the time sequence of fetal oxygenation, metabolic and cardiovascular parameters and on brain function of the sheep fetus was studied. It was also of importance to differentiate between cardiovascular alteration following TCO due to hypoxia and baroreceptor response, respectively. The investigations were performed on 11 near term pregnant sheep with dated gestational age of 126--137 days. Catheters were placed in the fetal aorta for monitoring fetal arterial blood pressure (FA BP), fetal heart rate (FHR). Blood samples were drawn and analysed for pH, PCO2 and SO2. An electromagnetic flow probe was placed around the common umbilical vein. Fetal EEG was measured over the right hemisphere. All parameters were studied over a varying time of TCO.

Animals↗
PubMed1980

Transcutaneous PO2 and cardiovascular observations in the sheep fetus following the reduction of uterine blood flow.

On 11 near term pregnant sheep the response of the fetal transcutaneous oxygen partial pressure (tcPO2) was compared with the alteration of the oxygen saturation (SO2) and the PO2 in the fetal aorta (FA), fetal heart rate (FHR) and fetal arterial blood pressure (FA BP) following the reduction of uterine blood flow (UBF). The FA SO2 changed 12.3 (SD 3.1) sec and the tcPO2 26.6 (SD 7.9) sec after UBF was reduced. The tcPO2 response was also delayed after UBF was restored: 72.6 (SD 41.9) sec compared to the SO2 response: 23.9 (SD 14.4) sec. The reduction of UBF was paralleled by a rise of the FA BF and a fall of FHR. They were at control within 10 min after the reduction of UBF was released reflecting the normalization of the tcPO2. There was a tcPO2-FA PO2-difference which was due to the difference that exist between the carotid artery PO2 and the PO2 in the fetal aorta. The delayed response of the tcPO2 electrode was due to the response time of the electrode itself. The delay during the recovery period however was predominantly due to the peripheral vasoconstriction as proved by Norepinephrine injection. The tcPO2 reflects very close the fall of the FA BP and the rise of the FHR during the recovery period and vice versa. The importance of the tcPO2-PO2,a difference for the fetal condition during labor has still to be worked out.

Animals↗
PubMed1980

[Constant fluoridation of drinking water and the incidence of dental caries in children and juveniles (author's transl)].

The regular examination of 20,000 children and juveniles aged 6 to 15 (permanent teeth) and some 12.500 three- to eight-year-olds (deciduous teeth) has shown that the incidence of dental caries (DMF/T and df/t indices) is directly dependent upon the constant fluoridation of drinking water (1.0 +/- 0.1 ppm F). The reduction in dental caries observed on both deciduous and permanent teeth as a result of twelve years of fluoridation of drinking water, which was started in Karl-Marx-Stadt in 1959, was followed, because of the necessity to temporarily discontinue the addition of fluorine salts to the drinking water, by a slight increase in caries which could be checked through refluorination. After eighteen years of fluoridation of drinking water, the situation can again be considered to be in equilibrium. The need for proper fluoridation and regular control thereof through analyzing the fluorine content of drinking water is pointed out.

Adolescent↗
PubMed1979

Placental clearance of lactate and bicarbonate in sheep.

To determine the placental clearance of lactate and bicarbonate in sheep, the fetal side of an isolated cotyledon and the umbilical circulation of the total placenta were artificially perfused. The release and uptake of lactate and bicarbonate by the perfusion fluid and the fetomaternal concentration differences of these substances were measured. From these data, the clearance of lactate and bicarbonate was determined to be 0.9 (SE = 0.2) ml/h/g of placental tissue. The production of lactate by the placenta was calculated to be about 30 mumol/min, the placental permeability of lactate was evaluated to be about 1.3 ml/h/g of placental tissue. These results indicate that fetal concentration changes of lactate and bicarbonate due to placental transfer occur with a half time of about 4 h. It is concluded that the lactate and bicarbonate permeability of the syndesmochorial placenta of the sheep is about 20 times smaller than the placental permeability of the hemochorial placenta of the guinea pig. It seems unjustified to draw any conclusions from experimental data obtained in the sheep placenta for the transplacental acid-base balance between mother and fetus in human beings.

Animals↗
PubMed1979

[Development of gingival inflammations in schoolchildren instructed in proper oral hygiene in a seven-year longitudinal study conducted under clinically controlled conditions and as part of the Preventive Stomatology research project (author's transl)].

Instruction of six- and seven-year-old children (N = 1167) at the beginning of this longitudinal study was given by a stomatological nurse at weekly intervals and, later, at fortnightly and monthly intervals, respectively. Compared with a group of untreated controls were not only those children who were instructed in proper oral hygiene but children receiving additional doses of amine fluorides as well. During the seven-year period of observation there was noted a distinct improvement in oral hygiene (OHI) as well as a reduction of gingival inflammations (PM index). Whereas additional administration of amine fluorides had no appreciable effect upon both oral hygiene and the condition of health of the gingiva there was a direct relation to the frequency of instructions in oral hygiene at school.

Child↗
PubMed1979

[Comparson of occlusal conditions in juveniles from residential areas with different drinking water fluoride contents (author's transl)].

The investigations reported in this paper were conducted in Karl-Marx-Stadt after 16 years from the introduction of drinking water fluoridation (1.0 ppm F), with a total of 792 randomly selected juveniles (whose average age was 14.9 years) being examined. Serving as a control group were 780 juveniles of the same age (15.4 years). The control persons were from Leipzig (0.2 ppm F). Included in the comparison with metric occlusal traits, use being made in this connection of the method for measuring occlusal traits, which was recommended in 1973 by an F.D.I. commission (COCSTOC-MOT). Despite the considerable reduction of caries in the deciduous dentition and the change in the eruptive behavior of permanent teeth, which is of great importance of the development, of dentition, no systematic differences could be observed between the two groups of subjects. An improvement in the occlusal conditions could not, after consumption of drinking water with an optimum fluoride content, be convincingly demonstrated by means of the epidemiological method used in these investigations.

Adolescent↗
PubMed1979

[20 years of fluoridation in the German Democratic Republic].

Caries-statistical data obtained from cross-sectional studies on more than 240,000 individuals having an age range from 3 to 18 years, at Karl-Marx-Stadt (where the drinking water contains 1 p.p.m. of fluoride) and several towns with low levels of fluoride content the repercussions of the caries reduction achieved on the system of organized paedodontic care. Due to further development on a legal basis, 1,3 million inhabitants (13%) of the GDR are at present provided with fluoridated water for caries-protective reasons. It is aimed at serving 50% of the inhabitants by 1990.

Adolescent↗
PubMed1979

A comparative study of continuous intravascular O2 saturation and transcutaneous PO2 measurements in the sheep fetus following the reduction of uterine blood flow.

Under physiologic conditions the tcPO2 reflects the PO2 in the carotid artery. It is therefore a measure of the PO2 in the arteries supplying the brain. The response of the tcPO2 to fetal hypoxemia, as during the recovery period following hypoxemia, is delayed. The delayed response of the tcPO2 during recovery is generated by the release of catecholamines into the fetal circulation. The reading of the tcPO2 corresponds better with the course of the heart rate decelerations and the increased blood pressure than with the course of the PO2 in the fetal aorta. The tcPO2 is, in this context, a reliable measure for the peripheral oxygenation and vasoconstriction. The tcPO2 however should be applied with great care for studying the pathomechanism of fetal heart rate decelerations during labor.

Animals↗