PRDM1/BLIMP1 is widely distributed to the nascent fetal-placental interface in the mouse gastrula.

BACKGROUND: PRDM1 is a transcriptional repressor that contributes to primordial germ cell (PGC) development. During early gastrulation, epiblast-derived PRDM1 is thought to be restricted to a lineage-segregated germ line in the allantois. However, given recent findings that PGCs overlap an allantoic progenitor pool that contributes widely to the fetal-umbilical interface, posterior PRDM1 may also contribute to soma. RESULTS: Within the posterior mouse gastrula (early streak, 12-s stages, embryonic days ∼6.75-9.0), PRDM1 localized to all tissues containing putative PGCs; however, PRDM1 was also found in all three primary germ layers, their derivatives, and two presumptive growth centers, the allantoic core domain and ventral ectodermal ridge. While PRDM1 and STELLA colocalized predominantly within the hindgut, where putative PGCs reside, other colocalizing cells were found in non-PGC sites. Additional PRDM1 and STELLA cells were found independent of each other throughout the posterior region, including the hindgut. The Prdm1-Cre-driven reporter supported PRDM1 localization in the majority of sites; however, some Prdm1 descendants were found in sites independent of PRDM1 protein, including allantoic mesothelium and hindgut endoderm. CONCLUSIONS: Posterior PRDM1 contributes more broadly to the developing fetal-maternal connection than previously recognized, and PRDM1 and STELLA, while overlapping in putative PGCs, also co-localize in several other tissues. Developmental Dynamics 246:50-71, 2017. © 2016 Wiley Periodicals, Inc.

Pharmacokinetics of ceftiofur sodium in equine pregnancy.

Eleven pregnant pony mares (D270-326) were administered ceftiofur sodium intramuscularly at 2.2 mg/kg (n = 6) or 4.4 mg/kg (n = 5), once daily. Plasma was obtained prior to ceftiofur administration and at 0.5, 1, 2, 4, 8, 12, and 24 hr after administration. Eight pony mares were re-enrolled in the study at least 3 days from expected foaling to ensure steady-state concentrations of drug at the time of foaling. Mares were administered ceftiofur sodium (4.4 mg/kg, IM) daily until foaling. Parturition was induced using oxytocin 1 hr after ceftiofur sodium administration. Allantoic and amniotic fluid, plasma, and colostrum samples were collected at time of foaling. Serial foal plasma samples were obtained. Placental tissues were collected. Desfuroylceftiofur acetamide (DCA) concentrations were measured in samples by high-performance liquid chromatography (HPLC). Mean (±SD) peak serum concentrations of DCA were 3.97 ± 0.50 µg/ml (low dose) and 7.45 ± 1.05 µg/ml (high dose). Terminal half-life was significantly (p = .014) shorter after administration of the low dose (2.91 ± 0.59 hr) than after administration of the high dose (4.10 ± 0.72 hr). The mean serum concentration of DCA from mares at time of foaling was 7.96 ± 1.39 µg/ml. The mean DCA concentration in colostrum was 1.39 ± 0.70 µg/ml. DCA concentrations in allantoic fluid, amniotic fluid, placental tissues, and foal plasma were below the limit of quantification (<0.1 µg/ml) and below the minimum inhibitory concentration of ceftiofur against relevant pathogens. These results infer incomplete passage of DCA across fetal membranes after administration of ceftiofur sodium to normal pony mares.

Differential proteomic analysis of bovine conceptus fluid proteins in pregnancies generated by assisted reproductive technologies.

Proteomic analysis of bovine conceptus fluid proteins during early pregnancy has the potential to expose protein species indicative of both the overall health of the fetal-maternal environment and fetal developmental status. In this study, we examined the differential abundance of bovine conceptus fluid proteins (5-50 kDa fraction) from naturally conceived, in vitro fertilisation (IVF) and somatic cell nuclear transfer (SCNT)-derived pregnancies at days 45 and 90 of gestation. In day 45 allantoic fluid (AllF) samples, an atypical cluster of low molecular weight ( approximately 14-16 kDa), low pI (between 3.0 and 4.5 pH units) protein species was increased in three of four IVF samples (30-100-fold increase in protein spot volumes compared to normal). These proteins were identified as paralogs of the bovine cathelicidin antimicrobial protein (CAMP) by MALDI-TOF MS peptide mass fingerprint and MALDI-TOF MS/MS peptide sequence analysis. Peptidoglycan recognition protein and serine (or cysteine) proteinase inhibitor clade B1, were also significantly increased in the corresponding IVF samples. In two of four SCNT AllF samples, a 2-10-fold increase in CAMP protein spot volumes were detected. No aberrant abundance levels of individual protein species were observed in amniotic fluid samples, or in day 90 IVF AllF samples. Identification of unique protein species present in the normal bovine AllF proteome at day 45 is also reported.

Capillary zone electrophoresis method for fingerprint of allantoic fluid in normal and infected SPF embryonated chicken eggs.

A capillary zone electrophoresis method was developed for fingerprint determination of allantoic fluid in specific pathogen free (SPF) embryonated chicken eggs. The effects of some crucial parameters, such as buffer type, pH, wavelength and running voltage on the separation were studied systematically. The components of the allantoic fluid were well separated using a fused-silica uncoated capillary with an effective length of 50 cm and an internal diameter of 50 microm. One hundred millimolars sodium tetraborate buffer containing 20 mM sodium dihydrogen phosphate with a final pH 9.8 was used as a running buffer. Comparative fingerprints of allantoic fluid in normal and infected with infectious bronchitis virus (IBV) SPF embryonated chicken eggs were also evaluated. The results showed that there were significant differences between composition of normal allantoic fluid and allantoic fluid infected with IBV, which led to different migration behavior. This method was shown to be stable and reproducible with a relative standard deviation of less than 5% for both migration time and peak current.

Continuous monitoring of penicillin G and gentamicin in allantoic fluid of pregnant pony mares by in vivo microdialysis.

REASONS FOR PERFORMING STUDY: Most current treatments for placentitis in mares are empirical with few control studies to evaluate their effectiveness. OBJECTIVE: To monitor drug concentrations in allantoic fluid of pregnant pony mares using in vivo microdialysis and establish if this method would be useful for determining allantoic concentrations of drugs in normal mares and those with placentitis. METHODS: Five late gestational pony mares had microdialysis probes inserted into the allantoic fluid using transabdominal ultrasound-guided allantocentesis. Single injections of penicillin G (22,000 u/kg), gentamicin (6.6 mg/kg bwt) and flunixin meglumine (1 mg/kg bwt) were administered i.v. and dialysate samples collected continuously for 24 h. In a separate study, drug concentrations were monitored in allantoic fluid of 2 mares with experimental placentitis induced by intracervical inoculation with Streptococcus equi ssp. zooepidemicus. Drug concentrations were measured by high performance liquid chromatography (penicillin G, flunixin meglumine) or enzyme-linked immunosorbent assay (gentamicin). RESULTS: Penicillin G and gentamicin achieved average peak concentrations of 9.8+/-2.2 and 8.5+/-3.1 microg/ml, respectively, in allantoic fluid of noninfected mares. Pharmacokinetic comparisons indicate that penicillin G persists much longer in allantoic fluid than blood, whereas gentamicin exhibited similar profiles in the 2 compartments. Flunixin meglumine was not detected in allantoic fluid. In infected mares, penicillin G achieved a similar peak concentration in allantoic fluid (11.2 microg/ml) whereas peak gentamicin concentration (3.9 microg/ml) appeared to be reduced relative to drug concentrations in noninfected mares. CONCLUSIONS: Microdialysis is a useful technique for continuous in vivo monitoring of drugs in equine allantoic fluid. Our results indicate that penicillin G and gentamicin undergo effective placental transfer in pregnant mares and in 2 mares that transplacental drug transfer may be altered selectively if active placental infection is present. POTENTIAL RELEVANCE: Further studies are needed to evaluate the feasibility of using increased dose intervals for penicillin G and an increased dose rate of gentamicin to effectively combat placental infections in mares.

Steroids in allantoic waste: an integrated measure of steroid exposure in ovo.

Recent studies examining patterns and consequences of variation in maternally deposited steroids in avian egg yolk have demonstrated that these maternal hormones can have dramatic effects on chick phenotypes. However, maternal steroids are not the only source for avian embryos, which activate endocrine axes relatively early in development and are capable of producing substantial amounts of endogenous steroids. Although organizational effects of steroids have been demonstrated, the interactions between steroids from yolk and endogenous production have not been addressed. Steroids in the yolk are likely to alter development of the embryo's endocrine axes. The ability to assess total steroid exposure in ovo in a nonlethal fashion would improve our understanding of these interactions and help elucidate the mechanisms by which maternal steroids alter chick phenotype. Steroid levels in allantoic waste provide a cumulative measure of steroids excreted in ovo and may prove to be a useful tool. We present data from semiprecocial seabirds, common murres, demonstrating the presence of detectable steroids in allantoic waste and suggesting that some reflect differences in timing of hatching and may provide information about aspects of chick phenotype.

Comparison of the concentrations of polychlorinated dibenzo-p-dioxins, dibenzofurans, and dioxin-like polychlorinated biphenyls in maternal and fetal blood, amniotic and allantoic fluids in cattle.

To characterize the maternal-fetal transport of lipophilic endocrine disrupting chemicals, concentrations of polychlorinated (2,3,7,8-substituted) dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs) were measured in maternal and fetal blood, and amniotic and allantoic fluids in cattle. Total toxicity equivalent quantity (TEQ) was highest in amniotic fluid on a fat-weight basis, whereas it was highest in maternal blood on a total weight basis. TEQ was lowest in allantoic fluid on either basis; 26 of 29 congeners analyzed in this experiment were detected in one or more samples. The largest number of congeners was detected in amniotic fluid. O8CDD, 2,3,4,7,8-P5CDF and 2,3',4,4',5-P5CB were the major congeners in PCDDs, PCDFs and PCBs, respectively. The O8CDD concentration was higher in fetal blood than in maternal blood on a fat-weight basis, whereas concentrations of other congeners were lower in fetal blood than in maternal blood. Furthermore, on a fat-weight basis, the O8CDD concentration was considerably higher in allantoic fluid compared with other samples. Concentrations of major PCB congeners were higher in amniotic fluid than in maternal and fetal blood on a fat-weight basis. In conclusion, it is suggested that lipophilic endocrine-disrupting chemicals contained in maternal blood are all transferred to the fetal circulation via the placenta in cattle. Furthermore, the results of this experiment imply that O8CDD has different transportation systems from other dioxins in the circulation, and that a considerable amount of PCBs is excreted and accumulated in amniotic fluid during the fetal stage in cattle.

Molecular detection and serotyping of infectious bronchitis virus from FTA filter paper.

We investigated the feasibility of using Flinders Technology Associates (FTA) filter cards for the storage of allantoic fluid containing an infectious bronchitis virus (IBV), such as Arkansas-DPI, Connecticut, and Massachusetts, and for their identification by reverse transcriptase (RT)-polymerase chain reaction (PCR) and characterization by restriction fragment length polymorphism (RFLP) or nucleotide sequencing. FTA paper is a cotton-based cellulose membrane containing lyophilized chemicals that lyses many types of bacteria and viruses. IBV was inactivated upon contact with the FTA, as shown by the inability of the virus to be propagated in embryonating chicken eggs. RT-PCR of the S1 gene showed that viral RNA in allantoic fluid remained stable after storage on FTA filter cards and that the stability was time and temperature sensitive for the large (1700 base pair [bp]) but not the small (383 bp) PCR products. Analysis of the amplified products showed that molecular characterization is feasible in allantoic fluid stored on FTA under nonfavorable environmental conditions (41 C) for at least 15 days. The use of FTA cards for the collection, transport, and storage of IBV-containing samples is safe, inexpensive, and adequate for molecular diagnosis. We propose that specimens coming from overseas on FTA cards would be first analyzed by RT-PCR with primers yielding a 1700-bp product followed by RFLP of the positive cases. Negative cases would be analyzed with primers yielding a 383-bp product (to exdude detrimental effect of the storage conditions) followed by nucleotide sequencing of the positive cases.

Immunohistochemical localization of bovine placental retinol-binding protein.

An immunogold staining method was used in combination with epipolarization microscopic detection to demonstrate the presence of bovine placental retinol-binding protein in bovine extraembryonic membranes. Amnion, chorion and allantois were fixed in Bouin fixation fluid and embedded in polyethylene glycol 1500. Sections (5 mm) were cut and transferred onto Digene silanated slides and immunostained using rabbit antiserum raised against bovine placental retinol-binding protein followed by goat anti-rabbit IgG labeled with 1 nm gold. Gold particles after silver enhancement were viewed and photographed under epipolarization microscopy. Epithelial cells of all three membranes (i.e. amniotic ectoderm, chorionic trophectoderm, and allantoic endoderm) were immunoreactive, while mesodermal cells, collagen, and blood cells were not. These data, together with our previous observation that these three placental membranes synthesize and secrete retinol-binding protein, indicate that epithelial cells lining the amnion, chorion and allantois are the major sources of this protein. The presence of retinol-binding protein in placental membranes and their fluids may be indicative of an important role for retinol in placental differentiation and development.

Effects of Prenatal Environment on Phenotype Are Revealed by Postnatal Challenges: Embryonic Hormone Exposure, Adrenocortical Function, and Food in Seabird Chicks.

The interaction between prenatal environments and postnatal environments is an important source of phenotypic variability. We examined the ability of prenatal steroid exposure and postnatal energy restriction to explain adrenocortical function and fledging age in captive seabird chicks. We proposed and tested two hypotheses: (1) the strength of prenatal effects is attenuated by challenging postnatal environments (postnatal override) and (2) the strength of prenatal effects increases with the severity of postnatal challenges (postnatal reveal). We reared common murre (Uria aalge) chicks and measured prenatal exposure to corticosterone (CORT) and testosterone (T) from allantoic waste. Adrenocortical function was assessed after 10 d of ad lib. feeding and then after 5 and 10 d on controlled diets. Postnatal override predicts that prenatal steroids will explain more phenotypic variation before implementation of energy restriction; postnatal reveal predicts that the contribution of prenatal steroids will increase with duration and severity of energy restriction. Energy restriction increased secretion of baseline CORT and the adrenocortical response to the standardized stressor of handling and restraint. The ability of prenatal steroids to explain baseline CORT increased with duration of energy restriction, and for day 20 free baseline CORT, there was a significant interaction between kilojoules per day and prenatal CORT levels; severity of restriction strengthened the relationship between prenatal hormone levels and postnatal hormone levels. Both maximum CORT at day 20 and fledging age were best explained by diet treatment and day 15 or day 20 baseline CORT, respectively. Overall, prenatal CORT increased fledging age and baseline secretion of CORT, while prenatal T decreased them. However, prenatal effects on adrenocortical function were apparent only under the energy restriction conditions. Thus, we found some support for the postnatal reveal hypothesis; our results suggest that some prenatal effects on phenotype may be more likely to manifest in challenging postnatal environments.

Effect of reproductive hormones on ovarian epithelial tumors: II. Effect on angiogenic activity.

Menstrual cycle activity predisposes to ovarian epithelial tumors based on numerous epidemiological studies. We showed that the hormones involved in menstrual cycle regulation modulate cell cycle activity in these tumors in an accompanying paper. We investigated whether such hormones could also influence angiogenesis, an important determinant of tumor progression, in the same tumors. Treatment with progesterone (P4) stimulated VEGF protein secretion in 4 of 5 ovarian carcinoma cell lines examined. Northern blot analyses performed in MCV50 cells showed that this effect was accompanied by increased VEGF mRNA levels. P4 also stimulated VEGF promoter activity in these cells. Estradiol (E2) showed a similar, but substantially smaller effect on VEGF secretion which was additive to that of P4. Conditioned medium from P4-treated cells strongly stimulated angiogenesis on chicken chorio-allantoic membranes. Incubating the conditioned medium with a neutralizing anti-VEGF antibody, but not with non-specific immunoglobulins abolished this effect. Angiogenic activity was not altered by treatment of the membranes with P4 directly. We conclude that P4 can stimulate angiogenic activity via induction of VEGF secretion in some ovarian epithelial tumors. Therapeutic use of progestins may be most effective when administered in combination with an anti-angiogenic agent, at least against a subset of ovarian carcinomas.

Dietary glycine inhibits angiogenesis during wound healing and tumor growth.

In this study we investigated the effects of glycine on angiogenesis during embryogenesis, wound healing and tumor growth. In chorioallantoic membrane (CAM) assay, glycine (100 microM) inhibited angiogenesis by more than 50%. We studied dietary glycine's effect on fibrin induced wound healing response in a novel (Fibrin Z-chamber) assay. Fibrin within the chamber triggers the healing cascade leading to formation of granulation tissue (GT) rich in blood vessels and stroma. GT was reduced by more than 30% (p < 0.0001) in dietary Glycine groups as compared to control. We found that microvessel density dropped significantly (15%, p < 0.0003) with dietary glycine whereas the other components of GT were unaffected. We evaluated tumor growth delay utilizing Tumor Z-Chamber (fibrin with R3230 mammary adenocarcinoma cells) since tumors take advantage of angiogenesis and matrix formation. We observed that tumor growth decreased by 15% (p < 0.03) and tumor microvessel density dropped by 20% (p < 0.03) with dietary glycine compared to controls. We found that iNOS protein levels were decreased significantly in both GT (24%-57%) and tumor tissue (19-75%). In conclusion, we found that dietary glycine is a potent anti-angiogenic agent that can reduce wound healing and tumor growth through reduction of iNOS expression.

Insulin-like growth factor II (IGF-II) secreted from HepG2 human hepatocellular carcinoma cells shows angiogenic activity.

Hepatocellular carcinoma (HCC) is a typical hypervascular tumor. Since insulin-like growth factor II (IGF-II) has been reported to play a significant role in liver regeneration and hepatocarcinogenesis, we initially examined its angiogenic effect on the chorioallantoic membrane (CAM) of 9-day-old chick embryos. We also investigated whether IGF-II secreted from HepG2 human hepatocellular carcinoma cells induces vascularization using the chick embryo CAM. We found that the concentrated conditioned media (CCM) of HepG2 cell culture induced angiogenesis on the CAM. We also identified IGF-II protein in the CCM from HepG2 cells by Western blot analysis. However, CCM from Chang liver cells, which are normal human liver cells and were free of IGF-II, did not induce angiogenesis in the CAM. These results suggest that IGF-II secreted from hepatocellular carcinoma cells may act as an angiogenic factor for the hypervascularization of HCC.

Amniotic and allantoic fluid concentrations of thyroxine, 3,3',5'-tri-iodothyronine, 3,3'-di-iodothyronine and 3',5'-di-iodothyronine in the pig during the period of gestation.

Thyroxine (T4), 3,3',5'-tri-iodothyronine (reverse T3; rT3) and di-iodothyronines (3,3'-T2 and 3',5'-T2) were measured in pig amniotic fluid (AF) and allantoic fluid (Al) between 32 and 113 days of normal pregnancy. Low but measurable quantities of T4 in AF and Al (2.1 +/- 0.3 and 3.2 +/- 0.5 nmol/l respectively) were found before the onset of fetal thyroid gland function, which indicates the maternal source of T4. The presence of rT3 (55.8 +/- 4.1 pmol/l in AF and 49.8 +/- 5.3 pmol/l in Al), 3,3'-T2 (45.5 +/- 0.6 pmol/l in AF and 49.2 +/- 9.2 pmol/l in Al) and 3',5'-T2 (20.8 +/- 2.6 pmol/l in AF and 24.0 +/- 2.2 pmol/l in Al) may be attributed to the monodeiodinase system already active in fetal pig tissues in early pregnancy, as demonstrated previously. T3 concentration was undetectable in both AF and Al. An approximately twofold increase in the levels of T4, rT3 and T2s in AF and Al at mid-gestation was observed. T4 and rT3 in AF showed a positive correlation with protein concentrations. AF rT3 concentration (but not T4) correlated with rT3 in the cord and maternal serum. The 3,3'-T2 and 3',5'-T2 in AF and Al showed parallel changes to rT3, while the rT3/3,3'-T2 and rT3/3',5'-T2 molar ratios remained constant. T4 concentrations in AF and Al were markedly lower than in corresponding maternal and fetal serum; the rT3 concentration in Al was equal to that in AF and two to four times lower than in fetal serum. In spite of differences between serum hormone patterns in the pig and human near term, iodothyronine concentrations in AF showed some similarities, mainly the following: undetectable T3, a strong correlation between rT3, T4 and AF total protein and the presence of 3,3'-T2 and 3',5'-T2 in measurable levels. Comparative data for Al, except the ones in the present study in the pig, are not available.

Evidence of H beta 58, a gene involved in mammalian placental development, in the three-toed skink, Chalcides chalcides (Squamata: Scincidae), a viviparous placentotrophic reptile.

The H beta 58 gene, whose disruption in mice causes reabsorption of the embryo at 9.5 days post-conception, is believed to be essential for development of the placenta. Although the H beta 58 gene is well conserved in some Amniota, nothing is known about its presence in reptiles, some species of which have developed a chorioallantoic placenta. In this work, we investigated the expression of H beta 58 mRNA and protein in the three-toed skink, Chalcides chalcides. H beta 58 protein expression was found in the uterine epithelium beginning from the peri-ovulatory stage. However, it increased strongly at the moment of placental formation, when a high level of expression of mRNA and protein was also observed in the extra-embryonic membranes. The expression of H beta 58 mRNA and protein was maintained, although to a lesser degree, in the placenta during late pregnancy. It was also present in the early embryo. Finally, cloning and sequencing of a gene fragment revealed strong homology of the reptile gene with that of mammals. The high degree of conservation of the gene in amniote vertebrates and its presence in a viviparous squamate reptile (as in mammals) indicates an important role of this gene in the chorioallantoic placenta formation and development.

Isolation and characterisation of a C(18) neutral steroid, oestra-5(10),7-diene-3,17-diol, from pregnant mare urine and allantoic fluid. Facile oxidation to yield oestra-5(10),6,8-triene-3, 17-diol (diol of Heard's ketone).

Oestradiene-3,17-diol and oestratriene-3,17-diol (or the diol of Heard's ketone (3-hydroxy-5(10),6,8-oestratriene-17-one) have been extracted on a large scale from pooled urines and allantoic fluid obtained from pregnant mares. Initial purification was achieved using column chromatography, and further purification by high performance liquid chromatography or silver nitrate (argentation) thin layer chromatography. The steroids were characterised using gas chromatography-mass spectrometry. Positions of the double bonds in ring B of oestradienediol were deduced on the basis of results of ultraviolet (UV) and nuclear magnetic resonance (NMR) spectroscopy, hydrogenation, and incubation studies with the enzyme 5-ene-3beta-hydroxysteroid dehydrogenase/steroid-4,5-isomerase. The reference steroid, 5,7-cholestadien-3beta-ol (7-dehydrocholesterol), with its conjugated double bond system, behaved entirely differently to oestradienediol, consistent with the latter having no conjugated system. These data, together with detailed results of NMR studies, have led us to designate the positions of the double bonds in oestradienediol as 5(10),7-. The instability of the dienediol became apparent when the steroid was converted to its bis-trimethylsilyl (TMS) ether. The phenomenon was exacerbated when derivatisation was performed at elevated temperatures or when the fraction containing the dienediol was stored at 4 degrees C prior to being derivatised. The facile oxidation product was shown to be 5(10),6, 8-oestratriene-3,17-diol, implying that the two steroids are related and, furthermore, that all the sites of unsaturation are in the B ring. Because of the facile oxidation of oestradienediol to oestratrienediol (the diol of Heard's ketone), we propose, that this, and by implication, Heard's ketone itself, are artefacts of the isolation procedures which were utilised in the original studies. A possible mechanism is proposed for the biosynthesis of 5, 7-oestradienediol from a ring-B unsaturated C(19) compound, involving C(19) demethylation without aromatisation.

Intrauterine and peripheral steroid concentrations and conceptus development in Meishan and Large White hybrid gilts.

Six Meishan and five Large White hybrid gilts were naturally mated to boars of the same breed during their tenth or third oestrous cycle respectively. Maternal serum progesterone and total oestrone were monitored throughout the pregnancy period. On Day 30 of gestation, all gilts were slaughtered and ovulation rate, embryonic survival, conceptus development and intrauterine steroidogenesis were evaluated. The results of the study confirm previous reports that Meishan pigs have a higher number of live conceptuses (P < 0.03), a higher rate of embryonic survival (92.1% v. 78.6% for Large White hybrids) and a higher ovulation rate (P < 0.02) than Large White hybrid gilts. Embryos from Large White hybrid gilts were heavier (P < 0.001) than Meishan embryos and placental lengths (P < 0.001) and weights (P < 0.001) were greater. The volume of allantoic fluid per conceptus was greater (P < 0.03) in Large White hybrid gilts. The oestradiol concentration in the allantoic fluid was greater in Large White hybrid gilts (P < 0.002), but the progesterone concentration in allantoic fluid did not differ (P > 0.15) between the breeds. More oestradiol was synthesized in vitro on a wet weight basis from placental tissue in Large White hybrid gilts than in Meishan gilts (P < 0.001); however, a positive linear relationship existed in both breeds between oestradiol synthesis and placental length (P < 0.005). Progesterone concentrations in maternal serum tended to be higher overall (P < 0.1) in Meishan gilts than in Large White hybrid gilts throughout the 30-day period of study and were significantly higher (P < 0.02) from Day 13 to Day 30.(ABSTRACT TRUNCATED AT 250 WORDS)

Exogenous heparin induces fibronectin overexpression parallel to angiogenesis in the extracellular matrix of the chick embryo chorioallantoic membrane.

Heparin (HE) was injected into the allantoic sac of chick embryo eggs on the 5th day of incubation. After 48 h, a morphometric analysis of angiogenic response and an immunohistochemical investigation of fibronectin (FN) and type IV collagen immunoreactivity in developing vasculature were performed in order to verify whether HE-related choriollantoic membrane (CAM) angiogenic activity was associated with overexpression of FN and/or type IV collagen changes in CAM extracellular matrix. Data to be presented show a close relationship between HE treatment, angiogenic processes, and overexpression of FN, but not of type IV collagen in CAM extracellular matrix. They agree with other studies proving a facilitating role of FN in angiogenic processes.

Chlorinated contaminants in chorio-allantoic membranes from great blue heron eggs at Whidbey Island Naval Air Station.

Chorio-allantoic membranes (CAMs) were collected and analyzed for chlorinated hydrocarbons as part of a wildlife toxicology demonstration project at Naval Air Station (NAS) Whidbey Island, Washington, USA. Concentrations of DDT, DDE, DDD, Aroclor 1254, and Aroclor 1260 were found at concentrations below 0.4 ppm for 13 of 14 samples. The low correlations among DDT and its metabolites in CAMs suggest herons are not being exposed to a consistent source of these compounds. Comparison of chlorinated hydrocarbon data for CAMs from three Puget Sound heron colonies, NAS Whidbey, Samish Island and Dumas Bay, indicates contaminant burdens in herons from NAS Whidbey and Samish Island are significantly lower than burdens in herons from Dumas Bay.

Effect of intrauterine position of conceptus development, placental and endometrial release of progesterone and estrone in vitro, and concentration of steroid hormones in fetal fluids throughout gestation in swine.

Twenty intact and 25 unilaterally hysterectomized-ovariectomized gilts were used to study the effect of fetal intrauterine position on conceptus development, concentrations of endogenous progesterone (P4) and estrone (E1) in the placenta and endometrium, and steroid hormone concentrations in amniotic and allantoic fluids during gestation. Gilts were hysterectomized at 40, 60, 80, or 100 d of gestation. Placental and endometrial tissues were pooled individually by the intrauterine position of the associated fetus and incubated separately, and concentrations of P4 and E1 in the medium were determined. Uterine status (intact or unilaterally hysterectomized-ovariectomized) did not affect any of the variables measured. Intrauterine position affected fetal and placental weights (P < 0.02 and 0.01, respectively) only at Day 40 of gestation. The weights of female fetuses bordered in utero by two males and their associated placentas were lower than those from other intrauterine positions. Intrauterine position had no effect on placental and endometrial P4 release or on E1, P4, and androgen concentrations in fetal fluids at any stage of gestation. At Day 100 of gestation, placentas associated with fetuses bordered by those of the same sex released more E1 than did placentas associated with fetuses bordered by those of the same opposite sex (P < 0.01). This study indicates that intrauterine position in swine has a limited effect on conceptus development and on placental and endometrial steroidogenic activity.