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Biomedical subjects

L Nylund

Publications and source records attributed to L Nylund.

65 records · Page 4Linked to original sources
PubMed1982

Maternal kinetics and transplacental passage of pethidine during labour.

1 Pethidine is commonly used in single doses as an analgesic in obstetrics. Plasma concentration-time profiles of pethidine after intramuscular administration of 1.5 mg/kg body weight to 16 pregnant women during labour were investigated. There was only a two-fold variation in peak plasma concentration (300-650 ng/ml). The mean (+/- s.d.) value of the apparent plasma half-life of pethidine was 3.4 (+/- 1.0) h which is not different from that in healthy controls. norpethidine plasma levels were not measurable (less than 10 ng/ml). 2 The placental transfer transfer of pethidine was studied at delivery in samples from the umbilical cord vessels and from a maternal peripheral vein. In another 14 patients serial determinations of pethidine concentration were made in foetal scalp blood and maternal venous blood simultaneously during the different stages of labour. The foeto-maternal drug ratio varied between 0.35 and 1.5 with a positive correlation between ratio and dose delivery time interval. The concentration of pethidine in umbilical cord plasma or blood varied between 60 and 400 ng/ml with dose-delivery time intervals of 30 min to 10.5 h. The foetal concentration of pethidine reached a peak-plateau value between 1-5 h after dose.

Female↗
PubMed1982

Acute effect of an antihypertensive drug, labetalol, on uteroplacental blood flow.

The effect of a new antihypertensive drug, labetalol, on uteroplacental blood flow was determined in eight pre-eclamptic women. After injection of 0.5 mCi of 113mIn the radioactivity in the placenta was recorded by a gamma camera linked to a computer and the placental blood-flow index was calculated from the ratio between the maximum radioactivity of the isotope-accumulation curve and the rise time of the curve. Labetalol, a combined alpha- and beta-adrenoceptor antagonist was given intravenously and after 30 min a second uteroplacental blood-flow index was calculated. There was a significant mean decrease of blood pressure from 147/98 to 128/83 mmHg, but no change in uteroplacental blood-flow index, so that uteroplacental vascular resistance tended to decrease.

Blood Pressure↗
PubMed1982

Utero-placental blood flow and the effect of beta 2-adrenoceptor stimulating drugs.

The immediate effect of a beta 2-adrenoceptor stimulating drug, salbutamol, on utero-placental blood flow in the last trimester of pregnancy was evaluated in 16 women without uterine contractions, using a method applying 113-m Indium and a computer-linked gamma camera. Serial scintigrams over the placental site showed a 15 per cent increase in activity during a short salbutamol infusion, denoting an augmented blood pool in the intervillous space. At the end of a 25--30 min salbutamol infusion, a mean prolongation of the rise time of the isotope accumulation curve by 100 per cent could be calculated. A utero-placental blood flow index derived from the ratio of the maximum activity and the rise time of the accumulation curve above the placenta showed a decrease ranging from 18 to 50 per cent. It is conceivable that this initial decrease would disappear during continued infusion, as has been shown to occur in the pregnant sheep model.

Albuterol↗
PubMed1979

Acute metabolic and circulatory effects of cigarette smoking in late pregnancy.

The acute metabolic and circulatory effects of cigarette smoking (two cigarettes of a standard brand) in the last trimester of pregnancy were studied. 12 subjects, all of whom where hospitalized because of pregnancy complications, volunteered to participate in the investigation. A statistically significant immediate increment in the maternal heart rate, systolic and diastolic blood pressure, fetal heart rate, plasma glucose and plasma cyclic AMP was noted. Plasma glycerol, plasma insulin and blood lactate did not change significantly. 30 min after smoking there was a small but significant increase in plasma nonesterified fatty acids, plasma beta-hydroxybutyrate and plasma C-peptide.

Blood Glucose↗
PubMed1979

Comparison of uteroplacental blood flow in normal and in intrauterine growth-retarded pregnancy. Measurements with Indium-113m and a computer-linked gammacamera.

Uteroplacental blood flow was studied with a noninvasive method using indium-113m and a computer-linked gammacamera. The blood flow was determined from the ratio of the maximum and the rise time of the isotope accumulation curve of the placenta. Eight pregnancies with intrauterine growth retardation (IUGR) were compared with 11 normal pregnancies. In the IUGR group the mean placental blood flow was only 1/4 of corresponding mean values of the normal group. The difference was highly significant (p less than 0.01).

Birth Weight↗
PubMed1979

Catecholamines in fetal blood during birth in man.

Catecholamines and pH were determined simultaneously in human fetal scalp blood during parturition and in umbilical artery blood at birth. During the course of six normal vaginal deliveries with relatively small changes in blood pH about a ten-fold increase in catecholamine concentration was found. During six deliveries complicated by falls in blood pH to < 7.25 much higher values were often encountered.

Epinephrine↗
PubMedDate not supplied

Comparison between measurements of maternal placental blood flow with dynamic placental scintigraphy and radioactive microspheres.

Two methods for measurements of maternal placental blood flow were compared, dynamic placental scintigraphy using 113mIndium and the radioactive microsphere distribution technique which was the reference method. These methods were both used before and after the blood flow was altered by a noradrenaline infusion in pregnant monkeys (Macaca fascicularis). The change of the blood flow values obtained by the two methods were compared. A statistically significant correlation between the two methods was found (r = 0.90, p less than 0.01). It is concluded that dynamic placental scintigraphy can be used as a technique for clinical measurements of relative changes of the maternal placental blood flow.

Animals↗
PubMedDate not supplied

Application of a semi-automated SOS chromotest for measuring genotoxicities of complex environmental mixtures containing polycyclic aromatic hydrocarbons.

Soxhlet-extracted samples of standard reference materials (SRMs) 1649 (PAR1: urban dust/organics) and 1650 (PAR2: diesel particulate matter) from the U.S. Institute of Standards and Technology were tested for induction of SOS functions using a semi-automated version of the SOS chromotest with Escherichia coli PQ37. Concentrations of 10 polycyclic aromatic hydrocarbons in the extracts were determined using reversed-phase HPLC. Only the diesel particulate matter (PAR2) extracts expressed SOS induction activity, which decreased when metabolic activation was used. Mutagenic PAH compounds (e.g., chrysene) were found in higher concentrations in the PAR2 extracts than in the PAR1 extracts but this could not explain the genotoxicity while it was mainly exhibited without metabolic activation. The direct genotoxic activity of the diesel particulate matter sample PAR2 is probably caused by nitroaromatic compounds; this was also supported by parallel studies with the Ames/Salmonella assay.

Air Pollutants↗
PubMedDate not supplied

Morphology of seminal and swim-up spermatozoa and the outcome of in vitro fertilization and embryo transfer.

Tubal infertility was treated by in vitro fertilization-embryo transfer (IVF-ET) in 112 couples. Twenty-eight pregnancies were obtained in 140 treatment cycles. Couples are accepted for treatment in our IVF-ET programme if previous semen samples fulfil the inclusion criteria: ejaculate volume greater than 1.5 ml, concentration of spermatozoa greater than 15 x 10(6) ml-1, greater than 40% motile spermatozoa, and greater than 25% spermatozoa with normal morphology. In order to determine to which extent IVF-ET treatment results are influenced by sperm morphology, within this selected group of patients, we have retrospectively analysed the data from both original semen samples and swim-up preparations. The sperm morphology was not related to the outcome of treatment in terms of fertilization (ovum cleavage rate), early embryo development, or pregnancy. Nor was any relationship detected between early embryo development or pregnancy and the degree of improvement in morphology resulting from the swim-up procedure. However, if improvement in morphology by swim-up was high, ovum cleavage rate was low. Sperm morphology within the limits set by our inclusion criteria could not predict the outcome of IVF-ET treatment. It is further concluded that the presence of abnormal spermatozoa at the site of fertilization may be without harm if only the number of normal sperms is high enough.

Embryo Transfer↗