Prostaglandin endoperoxide synthase-2 abundance is increased in brain tissues of late-gestation fetal sheep in response to cerebral hypoperfusion.

OBJECTIVE: To determine the mechanism by which cerebral hypoperfusion enhances prostanoid secretion by fetal brain tissues. METHODS: Studies were performed on five intact and five carotid sinus-denervated sheep fetuses (124-136 days) exposed to 10 minutes of cerebral hypoperfusion. Plasma collected from lingual artery and sagittal sinus, and microdialysates collected from brain stem and hypothalamus were assayed for prostanoid production. Fetal hypothalamus, cerebral cortex, hippocampus, cerebellum, and brain stem were collected from intact animals and 30 minutes after cerebral hypoperfusion for the expression, activity, and distribution of prostaglandin endoperoxide synthase-1 (PGHS-1), PGHS-2, and thromboxane synthase. RESULTS: Thromboxane B2 increased significantly in sagittal sinus compared with arterial blood, but PGE2 did not change. Thromboxane B2 decreased in brain stem and hypothalamus microdialysates, and prostaglandin E2 increased in these regions. PGHS-2 immunoreactive protein levels in brain tissues increased in the cerebral hypoperfusion fetuses compared with those of the intact animals. By contrast, PGHS-1 and thromboxane synthase protein levels did not change between these two groups. Prostaglandin endoperoxide synthase activity in brain tissues decreased with the increased levels of immunoreactive PGHS-2. CONCLUSIONS: 1) Prostanoids are produced in response to cerebral hypoperfusion, 2) the increase in the production of prostanoid responses to cerebral hypoperfusion is associated with the decrease in activity of, and therefore, the "suicide" inactivation of PGHS, and 3) PGHS-2 is the predominant form of PGHS, whose synthesis is induced by cerebral hypoperfusion in the fetal brain.     

Prostaglandin endoperoxide H synthase mRNA expression in the fetal membranes correlates with fetal fibronectin concentration in the cervico-vaginal fluids at term: evidence of enzyme induction before the onset of labour

Objective To determine the relationship of prostaglandin endoperoxide H synthase (PGHS) expression in the gestational tissues and fetal fibronectin in cervico-vaginal fluids before the onset of labour at term.
Design Cross-sectional, observational study.
Samples Amnion, chorion laeve and decidua were collected from 24 term pregnant women following elective caesarean section. Samples of cervico-vaginal secretions were obtained from the same women immediately before caesarean section.
Methods PGHS-1 and PGHS-2 mRNA levels in tissues were determined by specific ribonuclease protection assays. Fetal fibronectin concentrations in the cervico-vaginal fluids were measured by enzyme-linked immunosorbent assay. The abundance of PGHS mRNA was compared between groups of patients with the same mean gestational age but different cervico-vaginal fetal fibronectin levels. Linear regression analysis was used to determine the association between PGHS levels and fetal fibronectin.
Results Two groups of women were identified who had significantly different fetal fibronectin values but the same gestational ages. The group with the higher fetal fibronectin concentrations had significantly higher PGHS-1 and PGHS-2 mRNA levels in the chorion laeve and higher PGHS-2 mRNA levels in the amnion, than the group with lower fetal fibronectin concentrations. PGHS-1 and PGHS-2 mRNA levels in the chorion laeve and PGHS-2 mRNA in the amnion showed an overall significant association with fetal fibronectin levels.
Conclusions High concentrations of fetal fibronectin in cervico-vaginal secretions before the onset of spontaneous labour at term are associated with high levels of PGHS-2 mRNA in the chorion laeve and the amnion and of PGHS-1 mRNA in the chorion laeve. Increased expression of PGHS in these tissues may therefore be involved in the events leading to term birth.     

Inhibin subunits in human placenta: localization and messenger ribonucleic acid levels during pregnancy

This study describes the difference in distribution and levels of inhibin alpha, beta A- and beta B-subunit messenger ribonucleic acids in human placenta during pregnancy. Northern blot analysis indicated that inhibin alpha messenger ribonucleic acid is present in placental extracts collected at the early stage of gestation. Hybridization to inhibin beta A messenger ribonucleic acid was detected in the first trimester but in much lower levels. However, the intensity of the hybridization signal for inhibin alpha- and beta A-subunit messenger ribonucleic acids was greater in extracts prepared from term placentas than in those from the first or second trimester of pregnancy. Low levels of inhibin beta B-subunit messenger ribonucleic acid were observed only in extracts prepared from term placenta. At both early stage and term gestation trophoblast cells showed a positive fluorescent signal with the inhibin alpha-, beta A- and beta B-subunit-specific antisera. However, whereas inhibin alpha-subunit was localized in the cytotrophoblast, inhibin beta B-subunit immunoreactivity was observed in the syncytial layer of the villi, and inhibin beta A-subunit was widely distributed. The different distribution of immunoreactive inhibin subunits was confirmed by in situ hybridization, showing the different localizations of the inhibin messenger ribonucleic acids. These results showed that (1) human placenta produces the inhibin alpha- and beta A-subunits as early as the first trimester of pregnancy, (2) messenger ribonucleic acid levels for each of the three inhibin subunits are highest at term, and (3) immunoreactive inhibin subunits are localized differently in placental villi.     

Expression of vascular endothelial growth factor messenger ribonucleic acid and protein in human preimplantation embryos

In contrast to a previous report by Krussel et al., with the inclusion of larger numbers of unfertilized oocytes and normal embryos and more sensitive immunofluorescence, this study shows that expression of vascular endothelial growth factor messenger ribonucleic acid can be detected from the oocyte to the blastocyst stage and that protein can be detected from the 3-cell stage to the blastocyst stage in human preimplantation embryos.     

Tissue immunoexpression and messenger ribonucleic acid localization of inhibin/activin subunit in human epididymis

OBJECTIVE: To determine the expression of inhibin betaA and betaB subunits and follistatin and the ability of human epididymal epithelium to synthesize these molecules. DESIGN: The main aim of this study was to investigate the expression of inhibin alpha, betaA, and betaB-subunits and follistatin in human epididymis with immunohistochemistry, in situ hybridization, and Western blotting in adult life. SETTING: Academic university hospital. PATIENT(S): Epididymes were obtained from 10 men undergoing routine vasectomy or surgery for benign disease at the Royal Hallamshire Hospital, Sheffield, United Kingdom. MAIN OUTCOME MEASURE(S): Immunoexpression of activin betaA and betaB subunits and follistatin proteins and mRNA in human caput and cauda epididymis. RESULT(S): Positive immunoexpression for activin betaA and betaB subunits and follistatin were detected in different parts of the epididymis epithelium. Western blotting under a reducing condition detected a 28-kd band (possibly corresponding to the activin dimer). In situ hybridization indicated positive mRNA localization signal in both caput and cauda epididymal epithelium. CONCLUSION(S): Activins betaA and betaB subunits, but not inhibin alpha subunit, were detected in epididymal epithelium. These finding suggest that activins might have a role in the processes of sperm maturation and sperm fertilizing capability during transit and storage.     

Differential appearance of placentomes and expression of prostaglandin H synthase type 2 in placentome subtypes after betamethasone treatment of sheep late in gestation

Inappropriate fetal exposure to maternal glucocorticoid (GC) has been proposed as a mechanism for fetal programming where the effects of GC may be mediated by the placenta. However, the consequences of maternal GC on placental morphology and enzyme expression are unclear.

Objectives

We used betamethasone (BET) to determine effects on placentome subtype distribution and expression of prostaglandin H synthase type 2 (PGHS-2) enzyme.

Methods

Pregnant sheep carrying male fetuses were randomized to receive injections of saline (n = 30) or one (104 days of gestation, (dG); n = 6), two (104, 111 dG; n = 6) or three (104, 111, 118 dG; n = 11) doses of BET (0.5 mg/kg). Placental tissue was collected prior to (75, 84, 101 dG), during (109, 116 dG) and after BET (122, 132, 146 dG).

Results

Total number of placentomes was not different between gestational ages. A- and B-subtypes were most affected by prenatal BET exposure; numbers of A-subtypes were increased and numbers of B-subtypes were decreased compared to controls at 116 dG. At term numbers of A-subtypes were lower after BET, but the weight range distribution was similar to controls. In controls, placental PGHS-2 protein levels increased with gestational age and PGHS-2 localized primarily to uninuclear trophoblast cells. After BET, PGHS-2 protein in C-subtypes at term was significantly increased compared to A-subtypes.

Conclusions

Maternal BET treatment in late gestation affects the proportions of placentome subtypes and their differential expression of PGHS-2. Our data do not support previous hypotheses that A-subtypes develop into B-, C- and D-subtypes over the course of gestation.     

Latent herpesvirus hominis type 1 infection in the mother and passive acquired immunity in the newborn infant

The study aimed at determining the frequency of latent herpes virus hominis type 1 infection in healthy parturients. The infection can be detected only by the presence of anti herpes virus hominis type 1 antibodies in their blood. To this end 102 blood samples of both parturients and the umbilical cord were concurrently analysed by the complement fixation test. The mean geometrical antibody titer value in mothers was 13.968. More than 90% of the parturients examined had anti HVH type 1 antibodies in their blood. Out of 102 pairs (mother--umbilical cord) of blood samples, in 34 (33.34%) the observed anti HVH type 1 antibody titer was the same in the parturients' blood and in the umbilical cord blood, while in 62 samples (60.78%) the titer of these antibodies was twice as high in the umbilical cord blood than in the parturients. It appears that this transplacental transfer of anti HVH type 1 antibodies plays a significant role in the protection of the newborn against generalized HVH infection, although this kind of protection is limited in its duration and not so efficacious as cell-induced immunity.     

Immunocytochemical localization and messenger ribonucleic acid concentrations for human placental lactogen in amnion, chorion, decidua, and placenta

Human placental lactogen is one of the major hormones secreted by the placental syncytiotrophoblast and detected in the maternal circulation. Other sources of this hormone in intrauterine tissues at term have been sought by means of immunohistochemistry and northern analysis. Avidin-biotin immunoperoxidase staining with a specific polyclonal antibody to human placental lactogen showed this hormone to be present in groups of cells at the interface between chorionic cytotrophoblast and decidua parietalis and in some cells of the basal plate in addition to the classic source, the syncytiotrophoblast. Hybridization of polyadenylic-(+)ribonucleic acid extracted from amnion, chorion, decidua parietalis, basal plate, and placental trophoblast with a radiolabeled 48 mer oligonucleotide and a 540 base pair complementary deoxyribonucleic acid probe to human placental lactogen showed the placental trophoblast to be the major source of human placental lactogen and the extravillous chorion and basal plate to be additional minor sources.