PROBLEM: We determined the maternal‐fetal transport of immunoglobulin G (IgG) during the third trimester of human pregnancy.METHOD: The concentration of IgG and its subclasses (IgG1–4) was determined in sera of blood samples from 38... more
PROBLEM: We determined the maternal‐fetal transport of immunoglobulin G (IgG) during the third trimester of human pregnancy.METHOD: The concentration of IgG and its subclasses (IgG1–4) was determined in sera of blood samples from 38 pregnancies collected at the time of delivery from a peripheral maternal vein (MV) and from the placental umbilical artery (UA) and vein (UV). Gestational age varied between 28 and 42 weeks (WG).RESULT: Whereas placental weight showed a significant correlation with gestational age, the maternal level of IgG and the ratio of its subclasses did not vary with gestational age. At 28–33 WG (n = 15) the mean values in the UA (5.91 ± 1.53 g/1) and UV (6.41 ± 1.57 g/1) for total IgG concentration were lower than in the MV (10.74 ± 2.55 g/1). At the end of gestation (37–42 WG, n = 12), IgG in both UA (11.21 ± 1.95 g/1) and UV (12.26 ± 2.06 g/1) exceeded the maternal concentration (9.69 ± 1.84 g/1). In addition to the significant positive correlation between IgG c...
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ABSTRACT
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Das kontraktionsfreie Myometrium bietet zusammen mit den Eihäuten und der geschlossenen Zervix dem Fetus eine geschützte Umgebung für eine ungestörte Entwicklung. In dem Grenzbereich bestehend aus Dezidua und Zervix einerseits und der... more
Das kontraktionsfreie Myometrium bietet zusammen mit den Eihäuten und der geschlossenen Zervix dem Fetus eine geschützte Umgebung für eine ungestörte Entwicklung. In dem Grenzbereich bestehend aus Dezidua und Zervix einerseits und der Plazenta mit den Eihäuten andererseits kommt es zu einem direkten Kontakt zwischen mütterlichen und fetalen Geweben. Der Schutz des hemiallogenetischen Embryos vor Abstoßungsreaktionen des mütterlichen Immunsystems sowie die Versorgung des Fetus, die durch die speziellen Gewebsstrukturen, die sich in dieser Kontaktzone in der Frühschwangerschaft entwickeln, gewährleistet wird, sind für die erfogreiche Schwangerschaft von zentraler Bedeutung. Dieser Bereich entwickelt ferner endokrine Funktionen, durch die die Anpassung des mütterlichen Organismus an die besonderen Bedürfnisse einer Schwangerschaft erst möglich wird.
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There is clear evidence that the placenta produces leptin. However, it is still unclear to what extent leptin is released into the maternal and the fetal circulation. The aim of our study was to determine placental leptin release rates... more
There is clear evidence that the placenta produces leptin. However, it is still unclear to what extent leptin is released into the maternal and the fetal circulation. The aim of our study was to determine placental leptin release rates into these 2 compartments. In 10 term placentas, using dual in vitro perfusion of an isolated cotyledon, con- centrations of leptin,
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Zusammenfassung Das vorzeitige Auftreten von Wehen, Abgang von Fruchtwasser sowie eine frühe Reifung der Zervix ist gleichbedeutend mit einer drohenden Frühgeburt. Die Ströung des für den Status quo während der Schwangerschaft... more
Zusammenfassung Das vorzeitige Auftreten von Wehen, Abgang von Fruchtwasser sowie eine frühe Reifung der Zervix ist gleichbedeutend mit einer drohenden Frühgeburt. Die Ströung des für den Status quo während der Schwangerschaft verantwortlichen Gleichgewichts wird durch eine Kombination von endokrinen und parakrinen Mechanismen verursacht. Das “corticotropine releasing hormone” (CRH) scheint dabei in Bezug auf die Interaktion von endokrinem und immunologischem System eine Schlüsselfunktion einzunehmen. Die CRH-Produktion im Trophoblasten der Plazenta wird lokal durch proinflammatorische Zytokine, Hypoxie oder endokrin durch Cortisol oder Stresshormone stimuliert. Das CRH aktiviert einerseits die Hypothalamus-Hypophysen-Nebennierenachse des Fetus, andererseits stimuliert es die Synthese von Prostaglandinen, Endothelin und Oxytocin. Neben der Dezidua ist auch das Amnion eine wichtige Produktionsstätte von Prostaglandinen und dem sog. “platelet activating factor” (PAF). Für die Zervixreifung sowie den Blasensprung ist das Gleichgewicht von Proteasen und Inhibitoren von besonderer Bedeutung. Während der Schwangerschaft wird die Aktivität der Proteasen durch eine hohe Konzentration von Inhibitoren im Fruchtwasser unterdrückt. Entzündliche Veränderungen in den Geweben können durch eine vermehrte Produktion von Proteasen zu einer Störung dieses Gleichgewichts führen.
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Clearance indices (clearance of experimental material: clearance of antipyrine, CI) across the perfused human placenta were determined for urea, sodium, and chloride. The selected materials are of relatively small molecular weight and are... more
Clearance indices (clearance of experimental material: clearance of antipyrine, CI) across the perfused human placenta were determined for urea, sodium, and chloride. The selected materials are of relatively small molecular weight and are water soluble. Clearance of urea was determined under conditions of net transfer and of exchange and no difference was detected. Sodium and chloride clearances were measured as exchange rates. The CI were: urea, 0.32 and 0.38 toward fetus and mother, respectively); sodium, 0.28; and chloride, 0.41 (measured toward the fetus). Recalculation of data as the diffusion limitation (LD) facilitated comparison with data in the literature on the monkey, rabbit, and sheep. LD for urea was comparable among the four species whereas the sheep placenta differed, sharply limiting the diffusion of sodium and chloride. The discrepancy in the sheep between urea and sodium indicates that the low transfer rate of the latter cannot be explained by the "thickness" of the syndesmochorial placenta, as is often stated. Inferences concerning nitrogen metabolism in the fetus have been derived by others from data on transplacental urea gradients and urea clearance. Available data in the human are incomplete but are consistent with amino acids providing approximately 10% of fetal energy needs, with glucose serving as the predominant substrate.
Research Interests: Pregnancy, Humans, Placenta, Sheep, Female, and 9 moreAnimals, Urea, Perfusion, Sodium, Molecular weight, Fetus, Antipyrine, Maternal-fetal exchange, and Chlorides
Precise diagnosis of peri-intraventricular hemorrhage (PIVH) requires brain real-time ultrasound imaging procedure (US). However, maximal diagnostic efficiency of US lies between day 4 and 14 since fresh blood may initially appear... more
Precise diagnosis of peri-intraventricular hemorrhage (PIVH) requires brain real-time ultrasound imaging procedure (US). However, maximal diagnostic efficiency of US lies between day 4 and 14 since fresh blood may initially appear sonolucent. Because of this supposed interval required for clot formation to become visible on US, serum CPK-BB estimations were performed in the first 60 hours of life to determine precise biochemical timing of PIVH. A group of 50 preterm infants less than 1500 g birth weight (1120 +/- 320 g) and 34 weeks gestation (30 +/- 3.7 weeks) was studied. Serial CPK-BB measurements were performed in serum immediately after birth (T0), then serially at time T1 (6-10 h), T2 (20-30 h), T3 (40-60 h). The incidence of PIVH diagnosed on the third day of life was 30%. Total CPK-BB values at T0 in infants who developed PIVH were significantly higher than those of patients without cerebral bleeding (70.8 +/- 30.5 vs 20.9 +/- 10.7 U/l) (p less than 0.05). The same statistically significant results were not observed analysing the CPK-BB values at T1, T2 and T3. These results suggest that most pathological conditions responsible for enzyme release occur in the pre- or perinatal period.
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The potential of exogenous replacement therapy in surfactant-deficient states such as neonatal respiratory distress syndrome (RDS) is an area of intense clinical interest today. At present, a fundamental problem with any type of exogenous... more
The potential of exogenous replacement therapy in surfactant-deficient states such as neonatal respiratory distress syndrome (RDS) is an area of intense clinical interest today. At present, a fundamental problem with any type of exogenous surfactant is the uncertainty about potential effects on physiological defense mechanisms, such as differentiation and mobilization of peripheral leukocytes. Considering that newborn infants with proven bacterial infections have abnormal values of segmented (neutrophil) and nonsegmented (band) polymorphonuclear leukocytes, we studied 42 placebo- versus Curosurf-treated babies with severe RDS. Differential white blood cell (WBC) count was serially performed before and after treatment during the first days of life. The statistically significant increase in the proportion of bands in surfactant-treated babies did not coincide with clinical and bacteriologic evidence of possible infection. Some molecular interaction mechanisms influencing immature to mature WBC ratio are supposed. Among a variety of influences on the leukocyte count, surfactant replacement therapy needs to be considered for proper interpretation of hematologic data in babies treated for RDS.
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Recent studies indicate again that there is a deficit in the use of electronic health records (EHR) in German hospitals. Despite good arguments in favour of their use, such as the rapid availability of data, German hospitals shy away from... more
Recent studies indicate again that there is a deficit in the use of electronic health records (EHR) in German hospitals. Despite good arguments in favour of their use, such as the rapid availability of data, German hospitals shy away from a wider implementation. The reason is the high cost of installing and maintaining the EHRs, for the benefit is difficult to evaluate in monetary terms for the hospital. Even if a benefit can be shown it is not necessarily evident within the hospital, but manifests itself only in the health system outside. Many hospitals only manage to partly implement EHR resulting in increased documentation requirements which reverse their positive effect.In the United States, electronic medical records are also viewed in light of their positive impact on patient safety. In particular, electronic medication systems prove the benefits they can provide in the context of patient safety. As a result, financing systems have been created to promote the digitalisation of...
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To compare prenatal morphometric changes of umbilical cord components in intrauterine growth-restricted fetuses with and without abnormal umbilical artery Doppler parameters. Consecutive singleton intrauterine growth-restricted fetuses at... more
To compare prenatal morphometric changes of umbilical cord components in intrauterine growth-restricted fetuses with and without abnormal umbilical artery Doppler parameters. Consecutive singleton intrauterine growth-restricted fetuses at a gestational age of older than 20 weeks were compared with matched appropriate-for-gestational-age fetuses. Intrauterine growth restriction was defined in the presence of a sonographic abdominal circumference below the 5th percentile for gestational age at the time of sonography and a birth weight below the 10th percentile. The sonographic examination included pulsed Doppler measurements of the umbilical artery resistance index and measurements of the umbilical cord cross-sectional area and the umbilical cord vessel area. A total of 84 intrauterine growth-restricted fetuses and 168 appropriate-for-gestational-age fetuses were included in the study. All umbilical cord components (umbilical cord cross-sectional area, vein area, artery area, and Whar...
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The marked discrepancy between fetal and placental growth in the second half of pregnancy is reflected by a shift in balance of supply and demand from a state of oversupply in early pregnancy to a situation of relative shortage in late... more
The marked discrepancy between fetal and placental growth in the second half of pregnancy is reflected by a shift in balance of supply and demand from a state of oversupply in early pregnancy to a situation of relative shortage in late pregnancy. To some extent this shift is compensated by extensive morphological remodelling and functional adaptation of the placenta. The major features of placental remodelling are an increase in uterine and umbilical blood flow, an enlargement of the villous surface area and a reduction in diffusion distance between maternal and fetal blood. In addition to placental remodelling and maturation a rise in transplacental gradient because of a gradual decrease in fetal concentration of some vital substrates like glucose and oxygen further adds to an increased flux to the fetus in late pregnancy. A redistribution of the total supply between fetus and placenta with a greater fraction going to the fetus also helps to maintain the balance between supply and ...
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Clearance indices (clearance of experimental material: clearance of antipyrine, CI) across the perfused human placenta were determined for urea, sodium, and chloride. The selected materials are of relatively small molecular weight and are... more
Clearance indices (clearance of experimental material: clearance of antipyrine, CI) across the perfused human placenta were determined for urea, sodium, and chloride. The selected materials are of relatively small molecular weight and are water soluble. Clearance of urea was determined under conditions of net transfer and of exchange and no difference was detected. Sodium and chloride clearances were measured as exchange rates. The CI were: urea, 0.32 and 0.38 toward fetus and mother, respectively); sodium, 0.28; and chloride, 0.41 (measured toward the fetus). Recalculation of data as the diffusion limitation (LD) facilitated comparison with data in the literature on the monkey, rabbit, and sheep. LD for urea was comparable among the four species whereas the sheep placenta differed, sharply limiting the diffusion of sodium and chloride. The discrepancy in the sheep between urea and sodium indicates that the low transfer rate of the latter cannot be explained by the "thickness&q...
Research Interests: Pregnancy, Humans, Placenta, Sheep, Female, and 9 moreAnimals, Urea, Perfusion, Sodium, Molecular weight, Fetus, Antipyrine, Maternal-fetal exchange, and Chlorides
Fetal growth is compromised in animal models with high cortisol availability. In healthy pregnancies, the fetus is protected from high circulating cortisol levels by the placental 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2),... more
Fetal growth is compromised in animal models with high cortisol availability. In healthy pregnancies, the fetus is protected from high circulating cortisol levels by the placental 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2), which is reduced in preeclampsia. We hypothesized increased placental cortisol availability in preeclampsia as missing link to fetal growth restriction and prematurity. Placental tissue was obtained from 39 pregnant women dichotomized normotensive (n = 16) or preeclamptic (n = 23). Placental steroid hormone metabolites were analyzed by gas chromatography-mass spectrometry. Apparent 11beta-HSD2 enzyme activity was calculated as substrate to product ratio. Estradiol and pregnandiol positively correlated with gestational age. Cortisol was virtually absent in 93.8% of controls, yet detectable in 79.3% of preeclamptic samples resulting in an odds ratio (OR) of 0.019 (95% CI 0.002-0.185) for the presence of placental cortisol. Apparent 11beta-HSD2 activity directly correlated with birth weight (R2 = 0.16; p < 0.02) and gestational age (R2 = 0.11; p < 0.04) ensuing a reduced risk of premature delivery (OR 0.12; 95% CI 0.02-0.58). We conclude that normotensive pregnancies are characterized by an almost completely inactivated placental cortisol. In line with our hypothesis, reduced 11beta-HSD2 activity in preeclampsia is unable to abolish placental cortisol, a finding clearly associated with prematurity and low birth weight.
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This review focuses on the role of oxygen and the changes in oxygen levels in the different trimesters of pregnancy in the human placenta. In the first trimester, the physiological conversion of the spiral arteries restricts maternal... more
This review focuses on the role of oxygen and the changes in oxygen levels in the different trimesters of pregnancy in the human placenta. In the first trimester, the physiological conversion of the spiral arteries restricts maternal blood flow into the intervillous space creating a low oxygen environment for the trophoblast and the embryo. In the second trimester, progressive conversion of the spiral arteries allows unhindered entrance of maternal blood into the intervillous space. In early pregnancy, pathology of spiral artery conversion may promote premature flow of maternal blood resulting in miscarriage. In more advanced pregnancy, incomplete conversion of spiral arteries impairs maternal blood flow to the placenta, causing chronic hypoxia and growth restriction of the fetus. Chronically reduced maternal supply of oxygen to the placental-fetal unit may be partially balanced by metabolic reprogramming of the placenta. Acute impairment of oxygenation in the perinatal period and its effect on the placental-fetal unit will also be discussed.
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Research Interests: Engineering, Physics, Chemistry, Immune response, Biology, and 18 moreMalaria, Medicine, Multidisciplinary, Pregnancy, Humans, Placenta, Cord Blood, Female, Laser Scanning Confocal Microscopy, PLoS one, Newborn Infant, Endothelial cell, Plasmodium falciparum, Fetus, Immune Complex, Maternal-fetal exchange, Merozoite surface protein 1, and Prenatal Exposure
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The transfer and metabolism of L-carnitine, L-acetylcarnitine, and L-palmitoylcarnitine were studied in the human placenta at term by means of in vitro dual perfusion of a placental lobe. L-Carnitine transfer was 20% that of the freely... more
The transfer and metabolism of L-carnitine, L-acetylcarnitine, and L-palmitoylcarnitine were studied in the human placenta at term by means of in vitro dual perfusion of a placental lobe. L-Carnitine transfer was 20% that of the freely diffusing antipyrine and 40% that of L-lysine. The transfer of L-acetylcarnitine was similar to that of L-carnitine, but no placental transfer of L-palmitoylcarnitine was found. In contrast to L-lysine, L-carnitine, and L-acetylcarnitine were not actively transported from the maternal to the fetal circulation. No stereospecific transfer of carnitine across the placenta was found. However, there was stereospecific uptake of carnitine by placental tissue. The placenta exhibited an active carnitine metabolism by esterifying free carnitine and hydrolyzing carnitine esters taken up from the perfusion medium and releasing the metabolites into the fetal and maternal circulations.
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... Research: Original Article: PDF Only. Transfer Across Perfused Human Placenta. II. Free Fatty Acids. Dancis, Joseph; Jansen, Valerie; Kayden, Herbert J.; Schneider, Henning; Levitz, Mortimer. Collapse Box Abstract. Extract: The rate... more
... Research: Original Article: PDF Only. Transfer Across Perfused Human Placenta. II. Free Fatty Acids. Dancis, Joseph; Jansen, Valerie; Kayden, Herbert J.; Schneider, Henning; Levitz, Mortimer. Collapse Box Abstract. Extract: The rate of ...
Research Interests: Endocrinology, Genetics, Cardiology, Hematology, Nephrology, and 26 moreNeurology, Oncology, Pulmonology, Rheumatology, Epidemiology, Immunology, Nutrition, Dialysis, Public Health, Pregnancy, Allergy, Humans, Placenta, Carbon Isotopes, Female, Animals, Perfusion, Pediatric, Amino Acids, Sodium, Tritium, Fetus, Free Fatty Acid, Quntitative Thin Layer Chromatography, Antipyrine, and Maternal-fetal exchange
ABSTRACT
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A relatively simple perfusion technique of human placenta has been applied to the study of secretory proteins. Preferential secretion into the maternal circulation of human chorionic gonadotropin (HCG), human chorionic somatomammotropin... more
A relatively simple perfusion technique of human placenta has been applied to the study of secretory proteins. Preferential secretion into the maternal circulation of human chorionic gonadotropin (HCG), human chorionic somatomammotropin (HCS), follicle-stimulating hormone (FSH), and placental alkaline phosphatase has been demonstrated, contrasting with the bidirectional secretion of progesterone. Evidence is presented for the net synthesis of HCS during perfusion. The technique offers advantages in the study of synthesis and secretion of placental materials.