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Biomedical subjects

S Stray-Pedersen

Publications and source records attributed to S Stray-Pedersen.

33 records · Page 2Linked to original sources
PubMed1986

Altered angiotensin-prostanoid interactions in umbilical arteries in pregnancy-induced hypertension.

The production rate of four prostanoids (PGE2, PGF2 alpha, 6-keto-PGF1 alpha and TXB2) in human umbilical cords from normal pregnancies (control) and cases with pregnancy-induced hypertension (PIH) were compared. The cords in the PIH-group produced significantly less 6-keto-PGF1 alpha and more TXB2 than did those in the control-group. Production rates of PGE2 and PGF2 alpha were almost equal in the two groups. After stimulation with angiotensin II the PIH-cords displayed a far smaller increase in 6-keto-PGF1 alpha production compared to the control cords. The responses in PGE2 and PGF2 alpha production were again equal in the two groups. The present results indicate that the angiotensin-prostanoid interactions are disturbed in fetal as well as in maternal vessels. Such a disturbance may explain the observed relative hypersensitivity to angiotensin II observed in gravidae prone to develop pregnancy-induced hypertension.

6-Ketoprostaglandin F1 alpha↗
PubMed1984

Etiologic factors and subsequent reproductive performance in 195 couples with a prior history of habitual abortion.

A diagnostic screening program was applied to 195 couples with a prior history of habitual abortion (i.e., three or more consecutive abortions). Abnormalities were identified in 110 (56%) of the couples. Such identification was significantly more frequent in couples with primary habitual abortion than in couples with secondary habitual abortion (p less than 0.001) and also more frequent in couples with second-trimester abortions than in those with first-trimester abortions (p approximately equal to 0.01). The abnormalities most commonly observed were anomalies of the uterine body (15%), endometrial infections (15%), and cervical incompetence (13%). Hormonal dysfunctions were detected in 5%, and there were chromosomal aberrations in 3% of the couples. The women in the group showing abnormalities were offered surgical or medical treatment, and 80% of those who subsequently conceived carried their pregnancies to term. Among the couples with no abnormal findings, women receiving specific antenatal counseling and psychological support had a pregnancy success rate of 86%, as compared to a success rate of 33% observed in women who were given no specific antenatal care (p less than 0.001).

Abortion, Habitual↗
PubMed1982

On the pathogenesis of acquired hypo-beta-lipoproteinemia. A case associated with sideroblastic anemia.

A 71-year-old previously hypercholesterolemic woman developed gradually severe hypocholesterolemia of 1.55 mmol/l. Simultaneously she developed progressive sideroblastic anemia, altered erythrocyte morphology and defective platelet function. Hypo-beta-lipoproteinemia was demonstrated with abnormal lipid composition of both very low density (VLDL), low density (LDL) and high density lipoprotein (HDL) fractions. Other plasma lipids, as well as erythrocyte lipids, were normal. The fractional catabolic rate of homologous 125I-LDL was increased to 4-5-fold, while its rate of synthesis was normal. The patient's serum contained autoantibodies directed against LDL. It is concluded that her hypo-beta-lipoproteinemia was due to autoantibodies towards LDL causing an increased catabolism without any concomitant effect on the rate of LDL synthesis. It is suggested that acquired hypo-beta-lipoproteinemia can be subdivided into two types, one in which the primary defect is an increased catabolism due to immunoelimination, and another in which the primary defect is a decreased rate of LDL synthesis.

Aged↗
PubMed1981

Seminal plasma fructose, zinc, magnesium and acid phosphatase in cases of male infertility.

Determinations of fructose, zinc, magnesium and acid phosphatase were performed in seminal plasma from male partners in 225 barren couples. No specific changes in the concentrations of these substances could be observed in men showing either visible or palpatory abnormalities of the external genitals, the prostate or of the seminal vesicles, extreme changes in the number, morphology or motility of the sperms, increased sperm antibody titre or abnormal serum levels of testosterone or gonadotrophins. However, when the prostatic fluid contained numerous leukocytes, the concentrations of zinc, magnesium and acid phosphatase were significantly lower than in men having a cytologically normal prostatic fluid. Determinations of these substances may thus be of aid in the diagnosis of chronic prostatovesiculitis.

Acid Phosphatase↗
PubMed1981

A follow-up study among 285 men with azoospermia and severe oligozoospermia.

The present investigation deals with the answer to a simple questionnaire from 147 men with azoospermia and 138 men with severe oligozoospermia (sperm counts less than 10 million/ml), earlier admitted to our clinic as male partners in barren couples. Twenty men in the azoospermia group and 52 men in the oligozoospermia group had received different types of infertility treatment. The conception rates reported were 1.6% and 10% in the azoospermia group, and 19.8% and 17.3% in the oligozoospermia group for the untreated and treated subgroups respectively. Only 21% of the men were interested in adoption, whereas 61% answered that they were favourably inclined towards performance of heterologous insemination of their wives. No significant increase in the conception rate was observed in the couples who had achieved adoption. The marriages appeared to be remarkably stable, only 3.5% of the men were divorced or separated from their wives. These results emphasize the necessity of including control groups in treatment trials of male infertility and would also suggest that female partners in these couples should be treated more actively.

Adoption↗
PubMed1981

Hypospermiogenesis and chromosomal aberrations. A clinical study of azoospermic and oligozoospermic men with normal and abnormal karyotype.

Clinical examinations including cytogenetical analyses were performed in 356 male partners of barren couples, 176 with azoospermia and 180 men with sperm counts below 10 million/ml. The chromosomal aberrations observed were: Klinefelter's syndrome (15 cases), 46 XX (3), 47 XYY (1), Y-chromosome anomalies (5), robertsonian (8) and reciprocal autosomal translocations (1), and 46 XY 16 h + (1). If minor variants were excluded this gave an incidence of constitutional chromosomal abnormalities of 11.9% in the azoospermia group and 4.4% in the oligozoospermia group. The phenotypes expressed by the specific anomalies showed great variations and appeared to be practically indistinguishable from those individuals having a normal karyotype.

Chromosome Aberrations↗
PubMed1979

Amniotic fluid phosphatidylinositol and phosphatidylglycerol. I. Normal pregnancies.

Phosphatidylinositol (PI) and phosphatidylglycerol (PG) appear normally in the amniotic fluid during the last weeks of pregnancy. The present study indicated as have previous studies (5, 6, 8, 10) that these phospholipids are linked to the surfactant system in the fetal lung. The concentrations of lecithin (L), PI, PG and sphingomyelin (S) were measured in 207 samples from 165 normal pregnancies. The augmentation in PI was found to parallel that in lecithin, and the PI/S ratios reached maximum values at about 30 weeks of gestation. The augmentation in PG appeared about two weeks later. Eleven premature infants who contracted respiratory distress syndrome (RDS) had significantly lower PG concentrations than 15 premature infants with no RDS (p less than 0.01). No correlation to the PI concentrations could be observed. All but one of the 11 affected infants had low L/S ratios.

Amniotic Fluid↗
PubMed1979

Amniotic fluid phosphatidylinositol and phosphatidylglycerol. II. Diabetic and preeclamptic pregnancies.

139 samples of amniotic fluid from diabetic women collected during 34-39 weeks of pregnancy showed higher levels of lecithin, phosphatidylinositol (PI) and phosphatidylglycerol (PG) indicating an accelerated surfactant synthesis as compared to that observed in normal pregnancies (13). In ten infants with respiratory distress syndrome (RDS) delivered from diabetic mothers the lecithin/sphingomyelin (L/S), PI/S and PG/S ratios were generally low. Only four samples showed definitely immature L/S ratios, whereas the amniotic fluid content of PG in all samples was unmeasurable or low. In 56 samples of amniotic fluid collected during the third trimester from preeclamptic pregnancies PI/S and PG/S ratios after 36-37 weeks were comparable with those of normal pregnancies. In 11 neonates with subsequent RDS the L/S ratios were immature, and PG was critically low or lacking in the majority of the samples. No convincing association between the PI content and development of RDS could be observed in any of the groups.

Amniotic Fluid↗
PubMed1976

The effect of serotonin and transcapillary pressure on the capillary permeability in the rete mirabile of the eel (Anguilla vulgaris l.).

Measurements of transcapillary exchange of high-molecular dextrans, K+ and THO in the rete mirabile of eel (Anguilla vulgaris L.) have been made under steady-state conditions while the transcapillary pressure was varied and pharmaca added to the perfusates. Raising the transcapillary input pressure increased the exchange of dextrans and K+ but lowered that of THO. Histamine and ouabain had no effect on the transcapillary exchange of the test molecules. The highest dose (100 mug/ml) of serotonin reversibly increased the capillary permeability of D-75 000, K+ and THO while the medium dose (50 mug/ml) only raised the transcapillary exchange of K+ and THO. The lowest dose (10 mug/ml) had no permeability effect. Our main conclusion is that serotonin reversibly increases the area of the intercellular pores by affecting the capillary wall directly.

Air Sacs↗
PubMed1975

Qualitative and quantitative studies of the capillary structure in the rete mirabile of the eel, Anguilla vulgaris L.

The capillaries of the counter-current capillary organ, rete mirabile, have been studied by light microscopy and electron microscopy. The vasculature of this rete was found to have a cross-sectional area of about 5.25 mm2, and it consisted of 34,000 efferent (=arterial) and 22,000 afferent (=venous) capillaries. The total surface area was the same for the two types of capillaries. The capillary endothelial cells showed numerous pinocytotic vesicles, scattered giant vacuoles and cytoplasmic extrusions (microvilli) at the luminal surface. The majority of the intercellular junctions appeared to have patent gaps with a width of 110-120 A. The arterial capillaries appeared in many ways to be morphologically similar to skeletal muscle capillaries of mammals, whereas the fenestrated venous capillaries resembled those in the intestinal mucosa of mammals. Measurements of the ionic composition of the rete tissue indicated that the endothelial cells contained much less K+ than other cells, the rete containing approximately equimolar amounts of K+ and Na+. The functional significance of the structural and chemical observations are discussed.

Anguilla↗
PubMed1975

The capillary permeability of the rete mirabile of the eel, Anguilla vulgaris L.

Direct measurements of transcapillary exchange during steady-state conditions have been performed in the rete mirabile of the eel. The capillaries were found to be more than 30 times as permeable to THO (PTHO = 33.2 times 10(-5) cm sec-1), ethanol and antipyrine than to K+. The mutual relationship of the permeabilities for K+, Na+, urea and sucrose were similar to that between the corresponding free diffusion coefficients in water. The permeability characteristics did not change when the perfusate contained metabolic inhibitors. Additional of 1 mM/l of albumin lead to a significant transcapillary osmotic flow. NaCl, urea and sucrose, however, did not cause osmotic flow. Based on the quantitative values for permeability and volume flow the capillary pores should be about 1300 A and have a frequency of 1.3 times 10(6) per cm2 of the capillary surface, occupying an area of about 0.1% of the total area. The results obtained in the present investigation raise questions as to the validity of the Pappenheimer single-pore theory for transcapillary transport as well as to the fine structure of the capillary pores. As an alternative to Pappenheimer's theory a multi-pathway model is proposed in order to explain transcapillary transport.

Anguilla↗
PubMed1975

The effect of Ca++, Mg++ and H+ on the capillary permeability of the rete mirabile of the eel, Anguilla vulgaris L.

The effects of EDTA, and of varying pH on the capillary permeability in the rete mirabile have been investigated: EDTA had to be added to the perfusate in excess to the total content of Ca++ and Mg++ in plasma in order to elicit changes in the permeability. When exposed to sufficient amounts of EDTA, the capillary permeability to hydrophilic molecules increased several fold whereas the permeability to THO and lipid-soluble molecules remained unchanged. The increase in the permeability to high-molecular dextrans was delayed. When the EDTA-effect was maximal the mutual relationship between the permeabilities of THO and the lipid-insoluble molecules became close to the ratio between the corresponding free diffusion coefficients in water. During exposure to EDTA the content of K+ and Na+ of the rete tissue (mostly endothelial cells) became very similar to that of plasma. Similar effects were obtained when the rete was perfused with plasma having a pH below 4 or above 9. The EDTA-effect was reversible during its initial stage. Perfusions with plasma in which Ca and Mg had been removed by dialysis at pH 3.5 were performed. When an EDTA-effect had been induced with this type of perfusates, it could be reversed by addition of equimolar amounts of either Ca++ or Mg++. This indicates Ca++ and Mg++ to be equally important in order to assure normal permeability properties of the capillary membrane.

Anguilla↗
PubMed1975

The permeability of fish gills with comments on the osmotic behaviour of cellular membranes.

The permeability of eel gills to ions, lipid-soluble and -insoluble substances has been measured under steady-state conditions. The results obtained support the multi-pathway model for transcapillary transport (Stray-Pedersen and Steen 1975). The gills are 25 times more permeable to THO than to Na+ or K+. Metabolic inhibitors do not affect the transfer of substances across the gills. Exposure to EDTA or MS-222 changes the permeability properties to resemble those of an aquous barrier. The gills are 10 times less water permeable than the capillaries of the rete mirabile.

Animals↗
PubMedDate not supplied

Sperm penetration in capillary tubes with albumin-Ringer solutions.

Linear penetration of sperm from 65 different semen samples was investigated in Ringer solutions containing 1%, 3%, and 6% bovine albumin and in cervical mucus by use of the capillary tube test. A high degree of correlation was observed between the penetration distances recorded in the Ringer-albumin solutions, particularly in the 3% and the 6% solutions, as compared with those observed in cervical mucus. The relative number of spermatozoa with abnormal configuration was found to be markedly lower in the upper segment of the tubes, indicating a relationship between propulsive motility and normal morphology.

Cervix Mucus↗