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Biomedical subjects

L Nylund

Publications and source records attributed to L Nylund.

At least 55 records · Page 3Linked to original sources

Scheduled intermittent periods of in vitro fertilization treatments.

Organization and results of an in vitro fertilization program at the Huddinge University Hospital are given from its beginning in August 1985: 6 months in advance a scheme is scheduled with 2 weeks open for treatment followed by free intervals of 3-4 weeks. Follicular development is stimulated with clomiphene citrate and hMG, and assessed by analyses of estradiol and LH in serum combined with ultrasound examinations. Following the administration of hCG, eggs are collected by transvesical aspiration guided by ultrasound. The ova are inseminated with about 50,000 motile spermatozoa, and cultured for 48 h. Up to four eggs are transferred transcervically to the uterine cavity. 158 egg pickups have been performed (August 1985 to December 1987) in 106 patients resulting in fourteen intrauterine and two ectopic pregnancies, biochemical pregnancies not counted. This protocol has restricted routine work load allowing these treatments to be part of the clinical routine. It has also allowed the application of research programs and thus optimized limited resources.

Adult↗

Biological and environmental monitoring of occupational exposure to cyclophosphamide in industry and hospitals.

The aims of the study were to clarify potential exposure situations to anticancer agents during industrial processing, drug manufacture and hospital administration, using cyclophosphamide (CP) as the model compound. CP is considered an animal and human carcinogen, and it is shown to be an indirect mutagen in various test systems using several genetic endpoints. Environmental monitoring was performed by collecting ambient air samples during the different processing and handling stages. Both stationary and personal sampling was used. CP was analyzed by liquid chromatography (HPLC) and mass spectrometry (MS). The process materials and intermediates were also analyzed for genotoxic activity using the Ames test and SCE induction in CHO cells as endpoints. Biological monitoring studies were performed on 147 persons representing 5 groups of workers, control subjects and patients. In the experimental part of the project, the intermediates in the CP manufacturing process, CP I (nor-nitrogen mustard) and CP II (phosphoroxydichloride mustard) were found directly active in the 2 genotoxicity tests. These findings led to improvements in work hygiene when handling CP I and CP II in the process. The CP measurements showed that the highest potential-exposure sites occurred during specific operations of the process, e.g., during emptying of the drying drum and during tablet mass preparation (the range of CP concentrations in air was 0.16-0.49 mg/m3). The correlation between indirect genotoxicity and chemical analyses of the ambient air samples was good, revealing the activity to be due to cyclophosphamide. However, the air samples were found mutagenic without metabolic activation also in the beginning of the process; this is obviously due to CP II particles in the ambient air, since no CP was detected chemically. The personal protection of workers in the plant collaborating in the study is efficient and the production unit is equipped with the best available techniques to protect both the personnel and the quality of the drug. Both the urine mutagenicity analyses using strain TA1535 of Salmonella typhimurium as indicator and the cytogenetic analyses of peripheral blood lymphocytes using sister-chromatid exchanges or structural chromosomal aberrations as endpoints were negative. However, a statistically nonsignificant trend in increased number of micronuclei was observed in binucleated lymphocytes of the worker groups as compared with controls. The studies on the hospital use of CP were performed in 3 oncological units and 1 pharmacy unit.(ABSTRACT TRUNCATED AT 400 WORDS)

Air Pollutants↗

Smoking exerts a ketogenic influence in diabetic pregnancy.

Acute cardiovascular and metabolic responses to the smoking of two cigarettes were studied in 12 normal and 7 diabetic women in the last trimester of pregnancy. When the responses to smoking were compared between the healthy and diabetic women no statistically significant difference was found except for 3-hydroxybutyric acid where diabetic women but not the normal patients reacted with a pronounced increase. It is concluded that smoking exerts a ketogenic influence in diabetic pregnancy.

Diabetic Ketoacidosis↗

Comparison between a swim-up and a Percoll gradient technique for the separation of human spermatozoa.

Two methods of separating human sperm were compared using twenty-two semen samples. The sperm were separated by a swim-up technique or by self-migration on a Percoll gradient followed by medium change. After separation, the sperm obtained were assessed for progressive motility, ATP content, energy charge index ([ATP + 0.5 ADP]/[ATP + ADP + AMP]) and morphology. In general, and especially for semen samples containing less than 20 X 10(6) sperm/ml, separation by Percoll gradient selected sperm that were superior to those separated by the swim-up technique. The relatively high energy charge index (greater than 0.8) showed that the sperm tolerated the separation conditions well. It is suggested that self-migration on a Percoll gradient should prove useful for obtaining sperm of high quality.

Adenosine Triphosphate↗

Fetal catecholamines and the Apgar score.

The association between Apgar score, pH and catecholamine levels was investigated in 181 newborn infants with a gestational age between 29 and 43 completed weeks. Umbilical arterial blood was obtained before the first breath with the double clamp technique and pH was measured. Plasma adrenaline and noradrenaline were analyzed by high performance liquid chromatography. The Apgar score at 1 minute was above or equal to seven in 167 infants. Forty-four per cent of these infants had pH below 7.25. A negative correlation between log noradrenaline and pH (r = 0.52, p less than 0.001) and between log adrenaline and pH (r = 0.40, p less than 0.001) was found. In 14 infants the Apgar score was below seven. The median pH was 7.21 (range 7.02-7.32). Also in this group a negative correlation between log noradrenaline and pH (r = 0.60, p less than 0.05) and between log adrenaline and pH (r = 0.77, p less than 0.01) was noted. We concluded that the Apgar score is an insufficient measure of fetal asphyxia defined as fetal acidosis but rather reflects the vitality of the newborn.

Apgar Score↗

Nerve conduction in diabetic pregnancy. A prospective study.

Repeated neurographic examinations were performed during and after the pregnancies of 32 diabetic women who had no signs of neuropathy before pregnancy or at the initial examination during the first trimester. The motor conduction velocity, the sensory conduction velocity and the peak amplitude of the compound action potential of the investigated peripheral nerves were not affected by pregnancy. It is concluded that pregnancy does not impair nerve conduction or induce neuropathy in most diabetic women.

Action Potentials↗

Uteroplacental blood flow in pregnancy hypertension after the administration of a beta-adrenoceptor blocker, pindolol.

The effect of a beta-adrenoceptor blocker, pindolol, on uteroplacental blood flow was determined in 10 women with pregnancy hypertension using an isotope technique giving a very low radiation dose. 0.5 mCi 113mIn was injected intravenously before and 30 min after 10 mg pindolol was given orally. After the administrations of 113mIn serial scintigrams were recorded for 240 s by a gamma camera on line with a computer, and the placenta was outlined for time-activity analysis of the isotope accumulation curves. From these curves a relative measure of the uteroplacental blood flow could be determined. Pindolol induced a significant fall in mean arterial pressure but there was no reduction of uteroplacental blood flow index.

Cyclic AMP↗

Labetalol for the treatment of hypertension in pregnancy. Pharmacokinetics and effects on the uteroplacental blood flow.

Plasma levels of labetalol were measured in 7 hypertensive pregnant women who were given 200 mg three times daily orally. The plasma concentrations were usually lower than those reported in the non-pregnant state at a comparative dose. In 5 women the ratio between fetal and maternal plasma labetalol concentrations could be calculated at parturition. The median value of this quotient was about 50%. The effect of labetalol 1 mg/kg body weight intravenously was registered with functional placental scintigraphy. Fifteen women participated. A computer-linked gamma camera above the uterus registered the radioactivity in the placental region after two intravenous bolus injections of 18.5 MBq indium-113m chloride. From the radioactivity uptake curves, uteroplacental blood flow indices could be calculated before and 30 minutes after the labetalol injection. Despite a significant reduction in maternal blood pressure, no change in uteroplacental blood flow index was found. This could indicate that the vascular resistance in the maternal placental circulation was reduced by labetalol.

Ethanolamines↗

Fetal scalp catecholamines during labor.

Samples of scalp blood were collected from 129 fetuses during the first stage of labor for analysis of plasma norepinephrine and epinephrine concentrations by high-performance liquid chromatography. The catecholamine levels were related to scalp blood pH and fetal heart rate patterns during the 20-minute period preceding the collection of scalp blood. The median norepinephrine level was 9.2 nmol/L (range, 1.3 to 99.7), and the median epinephrine level was 0.5 nmol/L (range, less than 0.5 to 19.2) (n = 111) during the first stage of labor when the pH was above 7.25. The norepinephrine level was considerably higher than that in the resting adult. Significantly higher concentrations of catecholamines were found when scalp blood pH was below 7.26 (p less than 0.001). Maternal analgesia did not influence the fetal catecholamine levels in uncomplicated labor. Significantly higher concentrations of norepinephrine were found during the appearance of abnormal fetal heart rate patterns.

Analgesics↗

Uteroplacental blood flow index in intrauterine growth retardation of fetal or maternal origin.

Uteroplacental blood flow index was determined in 30 women with intrauterine growth retardation (IUGR group) and in 26 women without fetal growth retardation (control group) during the last trimester of pregnancy. After 1 mCi (37 MBq) of indium-113m chloride had been injected intravenously the radiation was registered by a computer-linked scintillation camera positioned above the placenta during 10 s-intervals for 240 s. From the isotope accumulation curve a uteroplacental blood flow index could be calculated for each patient. The median blood flow index in the IUGR group was less than half of that in the control group. In the IUGR group the index was as low in the six women who gave birth to infants with congenital malformations as in the other 24 women in whom fetal growth retardation was due to maternal factors.

Adolescent↗

Acute effect of dihydralazine on uteroplacental blood flow in hypertension during pregnancy.

The uteroplacental blood flow was measured in 12 women with hypertension during pregnancy before and after intravenous injection of dihydralazine. After intravenous administration of 18.5 MBq (0.5 mCi) 113mIn, the gamma radiation emanating from the placenta was recorded with a computer-linked gamma camera during 10-second intervals for 240 s. From time-activity analysis of the isotope curve a uteroplacental blood flow index could be calculated. 30 min after the intravenous injection of dihydralazine, 18.5 MBq 113mIn were again administered, and a second uteroplacental blood flow index was calculated. After dihydralazine administration there was a significant reduction of mean blood pressure (p less than 0.01) and an increase of mean maternal heart rate (p less than 0.01). There was no significant change in uteroplacental blood flow or in uteroplacental vascular resistance.

Blood Pressure↗

Functional placental scintigraphy. A methodologic and clinical investigation.

A method to determine the uteroplacental blood flow in the last trimester of pregnancy is presented. After intravenous injection of 37 MBq 113Inm the radiation above the placenta was recorded in 10 s intervals for 240 s by a scintillation camera. The data are presented in a time-activity curve, in which the maximum activity is proportional to the placenta volume, rise time can be defined and the quotient maximum activity/rise time is calculated. This quotient is an index of the uteroplacental blood flow which can be used for comparison of a series of patients.

Female↗

Uteroplacental blood flow in diabetic pregnancy: measurements with indium 113m and a computer-linked gamma camera.

The uteroplacental blood flow index in the last trimester of pregnancy in 26 women with diabetes mellitus was compared to that in 41 healthy control subjects. After an intravenous injection of 1 mCi of indium 113m, the radiation over the placenta was recorded with a computer-linked gamma camera. From time-activity analysis of the isotope accumulation curve, a uteroplacental blood flow index could be calculated. In the diabetic pregnant women, the maternal-placental blood flow index was reduced 35% to 45% compared to that in healthy women. The blood flow index tended to be further impaired in those diabetic women who had higher blood glucose values.

Adolescent↗

Labetalol, a combined alpha- and beta-blocker, in hypertension of pregnancy.

Labetalol was given to women with hypertension of pregnancy in their last trimester to study its acute effect on circulation and metabolism. Seven women were given 50 mg labetalol i v. There was a significant decrease of blood pressure from a mean of 143/101 +/- 4/2 (SEM) to 127/88 +/- 5/2 mm Hg. Maternal heart rate fell significantly from 77 +/- 5 to 68 +/- 3 beats per min. These changes persisted during a three-hour observation period. The hypotensive response was accompanied by a significant increase in plasma noradrenaline from 1.54 +/- 0.16 to 2.37 +/- 0.41 nmol/l, suggesting sympathetic activation. Plasma cyclic AMP, which is increased by beta 2-adrenoceptor stimulation, was significantly elevated after labetalol. This supports the hypothesis of partial beta-agonist activity of labetalol. Lipid metabolism, as judged from measurements of plasma FFA, glycerol and 3-hydroxybuturic acid, showed little change. The acute effect of labetalol on uteroplacental blood flow was determined in eight women with pregnancy hypertension using a gammacamera on line with a computer. 0.5 mCi indium-113m was given i v before and 30 min after labetalol was administered i v in a dose of 1 mg per kg body weight. After the injections of indium-113m, serial scintigrams were recorded during 10 s periods for 240 s. By computerized summation of the scintigrams, an image was obtained in which the placenta could be outlined for time-activity analysis of the isotope accumulation curve. From this curve a uteroplacental blood flow index could be calculated. Labetalol induced a significant drop of mean arterial blood pressure from 114 +/- mm Hg to 100 +/- 3 mm Hg after 30 min in this group of women. However, the uteroplacental blood flow index did not change. As we have earlier shown with this technique that uteroplacental blood flow can be severely impaired in hypertension of pregnancy, the finding of substained uteroplacental blood flow simultaneously with a decrease in blood pressure should be of clinical importance. Taken together with other studies of clinical effects, these results indicate that labetalol is useful in the treatment of hypertension of pregnancy.

Adult↗