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Effect of estrogen on the metabolism of cortisol and cortisone in the baboon fetus at midgestation.

To determine whether the metabolism of cortisol (F) and cortisone (E) in the baboon fetus is regulated by estrogen, fetal interconversion of F/E was measured at midgestation after an experimental increase in placental estradiol (E2) production. Six baboons (Papio anubis) received increasing numbers of androstenedione implants (50 mg) inserted s.c. at 8-day intervals between Days 70 and 100 of gestation (term = Day 184) to elevate the production of estrogen; controls (N = 8) received no treatment. On Day 100 of gestation, each animal was anesthetized with ketamine:halothane/nitrous oxide, the fetus was exteriorized and [3H] F/[14C] E was infused via a fetal femoral vein for 70 min. Blood samples were then obtained from the contralateral fetal femoral vein, the umbilical vein/artery, and a maternal saphenous vein. After purification of F and E, the metabolic clearance rate (MCR), peripheral interconversion, and placental extraction of F and E were calculated. Maternal serum E2 concentrations (ng/ml; mean +/- SE) between Days 80 and 100 of gestation were greater (p less than 0.01) in androstenedione-treated baboons (2.2 +/- 0.2) than in untreated controls (1.2 +/- 0.1). Although the MCR of F was similar in control (5.2 +/- 0.3 1/day) and treated (7.7 +/- 1.0 1/day) animals, the MCR of E (13.5 +/- 2.0 1/day) was increased (25.8 +/- 2.5 1/day; p less than 0.05) by androstenedione treatment. Placental extraction of F (59 +/- 9%) was lower (p less than 0.01) than that of E (82 +/- 5%) in untreated baboons and was not affected by androstenedione treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Androstenedione↗

Placental, maternal serum and amniotic fluid molecular weight forms of inhibin A and pro-alphaC.

Previous studies have identified the presence of unidentified small molecular weight (mol wt) forms of inhibin and the pro-alphaC region of the inhibin alpha subunit in serum from women during late pregnancy. The aim of this study was to investigate if these gestational-related changes in mol wt forms arose from changing placental production. Pooled placental extracts, derived from normal healthy singleton pregnancies in the 1st, 2nd and 3rd trimesters of pregnancy, were fractionated by a combined immunoaffinity chromatography, preparative PAGE and electroelution procedure. Inhibin A, inhibin B and the pro-alphaC region of the inhibin alpha subunit were determined in the eluted fractions by specific ELISAs, with the profiles of immunoactivity characterized in terms of molecular size and percentage recovery. Inhibin B was undetectable in all samples. Mol wt peaks of 36k, 75K and 97K for inhibin A and 29k, 55K and 97K for pro-alphaC were detected in placental extracts across all three trimesters. The relative abundancy of small mol wt inhibin A forms (<30K) present in the placenta increased significantly in the third trimester placenta, increasing from 0.3 per cent in the first trimesters to 6 per cent in the third trimester (P=0.01, chi-squared test). The relative abundances of various mol wt forms of pro-alphaC was similar at all three gestations (P=0.67). In serum, small mol wt inhibin A and pro-alphaC forms accounted for 23.4 per cent and 37.4 per cent of inhibins, respectively, in the third trimester. These data suggest that the presence of small mol wt forms of both inhibin A and pro-alphaC in maternal serum is only partially attributed to placental production and/or secretion. We conclude that inhibin A and pro-alphaC inhibins in maternal serum are processed in late pregnancy by more than one mechanism to form low mol wt circulating forms of, as yet, undetermined structure.

Adult↗

Interventions for treating oral mucositis for patients with cancer receiving treatment.

BACKGROUND: Treatment of cancer is increasingly effective but associated with short and long-term side effects. Oral side effects, including oral mucositis (mouth ulceration), remain a major source of illness despite the use of a variety of agents to treat them. OBJECTIVES: To assess the effectiveness of interventions for treating oral mucositis or its associated pain in patients with cancer receiving chemotherapy and/or radiotherapy. SEARCH STRATEGY: Computerised searches of Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE and EMBASE were undertaken. Reference lists from relevant articles were searched and the authors of eligible trials were contacted to identify trials and obtain additional information. Date of the most recent searches August 2003: (CENTRAL) (The Cochrane Library Issue 3, 2003). SELECTION CRITERIA: All randomised controlled trials comparing agents prescribed to treat oral mucositis in people receiving chemotherapy and/or radiotherapy. Outcomes were oral mucositis, time to heal mucositis, oral pain, duration of pain control, dysphagia, systemic infection, amount of analgesia, length of hospitalisation, cost and quality of life. DATA COLLECTION AND ANALYSIS: Data were independently extracted, in duplicate, by two reviewers. Authors were contacted for details of randomisation, blindness and withdrawals. Quality assessment was carried out on these three criteria. The Cochrane Oral Health Group statistical guidelines were followed and relative risk values calculated using fixed effect models. MAIN RESULTS: Twenty-five trials involving 1292 patients satisfied the inclusion criteria. Three agents, each in single trials, were found to be effective for improving (allopurinol RR 3.33, 95% CI 1.06 to 10.49; immunoglobulin RR 1.81, 95% CI 1.24 to 2.65; human placentral extract RR 4.50, 95% CI 2.29 to 8.86) or eradicating mucositis (allopurinol RR 19.00, 95% CI 1.17 to 307.63). Two of these trials were rated as at moderate risk of bias and one as at high risk of bias. The following agents were not found to be effective: benzydamine HCl, sucralfate, tetrachlorodecaoxide, chlorhexidine and 'magic' (lidocaine solution, diphenhydramine hydrochloride and aluminum hydroxide suspension). Six trials compared the time to heal and mucositis was found to heal more quickly with two interventions: Granulocyte Macrophage-Colony Stimulating Factor when compared to povidone iodine, with mean difference -3.5 days (95% CI -4.1 to -2.9) and allopurinol compared to placebo, with mean difference -4.5 days (95% CI -5.8 to -3.2). Three trials compared patient controlled analgesia (PCA) to the continuous infusion method for controlling pain. There was no evidence of a difference, however, less opiate was used per hour for PCA, and the duration of pain was shorter. One trial demonstrated that pharmacokinetically based analgesia (PKPCA) reduced pain compared with PCA, however more opiate was used with PKPCA. REVIEWERS' CONCLUSIONS: There is weak and unreliable evidence that allopurinol mouthwash, vitamin E, immunoglobulin or human placental extract improve or eradicate mucositis. There is no evidence that patient controlled analgesia (PCA) is better than continuous infusion method for controlling pain, however, less opiate was used per hour, and duration of pain was shorter, for PCA. Further, well designed, placebo-controlled trials assessing the effectiveness of allopurinol mouthwash, immunoglobulin, human placental extract, other interventions investigated in this review and new interventions for treating mucositis are needed.

Humans↗

Detection of N-terminal pro-corticotrophin releasing hormone (CRH) and a 'novel' CRH in human maternal plasma and placenta.

Corticotrophin-releasing hormone (CRH) is released from the human placenta in high concentrations towards the end of the third trimester of pregnancy, but relative concentrations of other cleavage products derived from the CRH prohormone are unknown. We have measured CRH and N-terminal (1-100) and (1-127) proCRH peptides in maternal plasma in the second and third trimesters of pregnancy and in term placental extract using immunoradiometric assays (IRMAs) specific to different regions of the CRH precursor. Levels of N-terminal proCRH (amino acid residues 1-100) rose from 24+/-4 pmol/l (mean+/-s.e.) in the second trimester to 378.8+/-65 pmol/l (mean+/-s.e.) at term. Levels of intact proCRH and/or (1-127) proCRH remained relatively constant throughout the second and third trimesters, with a concentration of 29.3+/-3.8 pmol/l (mean+/-s.e.). In the course of this work a novel form of CRH that cross-reacts within specific CRH immunoassays was observed. The use of two IRMAs developed for CRH (1-41) having different C-terminal epitope specificities provided evidence for two types of CRH coexisting in maternal plasma. Separation of term placental extract by HPLC and application of the two CRH IRMAs revealed two peaks of immunoreactivity one of which coeluted with synthetic CRH (1-41).

Corticotropin-Releasing Hormone↗

Development, validation and application of a two-site enzyme-linked immunosorbent assay for activin-AB.

Monoclonal antibodies, specific for the beta A and beta B subunits of activin, were used to develop a new two-site ELISA for activin-AB. The assay had a detection limit of 0.19 ng/ml. High concentrations of activin-AB were found in bovine, ovine and porcine follicular fluids (FF), with less in human FF (1310, 1730, 688 and 7 ng/ml respectively). Recovery of spiked activin-AB standard from human, bovine and ovine FFs and from homogenized human placental extracts averaged 91%, 115%, 115% and 94% respectively. Within-plate coefficients of variation for different concentration of activin-AB were between 1.3% and 2.67%. The between-plate coefficient of variation was 5.5%. Cross-reactivity experiments showed the high specificity of the assay for activin-AB, with inhibin-A, inhibin-B, follistatin, activin-A and activin-B all cross-reacting < 0.2%. Incubation with high concentrations of follistatin (500 ng/ml) prior to assay did not affect the recovery of activin-AB. Samples of bovine, porcine, ovine and human FF gave dose responses parallel to that of the standard, as did bovine granulosa cell-conditioned media. In human and porcine FF, levels of activin-A and activin-AB were similar whereas, in bovine and ovine FF, activin-A levels were approximately threefold higher than activin-A, nearly all of the endogenous activin-AB in bovine FF was detected in the eluate from gel permeation chromatography with an M(r) of > 700000 indicating its association with higher molecular weight binding protein(s). By contrast, after denaturation, immunoreactive activin-AB was detected with an M(r) of approximately 25000 consistent with the complete dissociation from binding proteins. Activin-A was detected in relatively high concentrations in human FF (approximately 5 ng/ml), homogenized placental extracts (4.35-95.5 ng/g), sera from pregnant women (> 4 ng/ml) and amniotic fluid (3-13 ng/ml), and in much lower concentrations in postmenopausal serum (500 pg/ ml), normal cycle serum (100-200 pg/ml), serum from gonadotrophin-treated women (200 pg/ml), and normal adult male serum (225 pg/ml). Activin-A was also found in the culture media from explants of human amnion, chorion, maternal decidua and placenta. In marked contrast, activin-AB was undetectable (< 0.19 ng/ml) in all of these samples with the exception of human FF (approximately 7 ng/ml). In conclusion, we have developed a sensitive and specific ELISA to measure total (bound+free) activin-AB. Preliminary results show a more restricted distribution of this isoform compared with activin-A. The presence of high levels of both activin-A and activin-AB in FF suggests a function for both isoforms in the developing ovarian follicle.

Activins↗

Qualitative and quantitative analyses of human chorionic gonadotropin and its subunits produced by malignant tumors.

Human chorionic gonadotropin (hCG) and its subunits in plasma, urine, ascites, and tumor extracts from four patients with hCG-producing tumors (undifferentiated cell carcinoma and choriocarcinoma of the bladder, malignant teratoma of the retroperitoneum, and pancreatic carcinoma) were measured by the radioimmunoassays specific to each component. While both free alpha and beta subunits as well as the whole molecule of hCG were found in all these samples, the proportion of beta subunit was much higher in these tumor extracts than in the placental extracts. Since the alpha and beta subunits are known to be translated from separate mRNAs, such increase of subunit is probably due to the predominant increase of mRNA encoding beta subunit of hCG in the hCG-producing tumors. Gel filtration of the extracts of these four tumors on Sephadex G-100 and G-150 columns demonstrated a heterogeneity of hCG, alpha, and beta subunits in these tumor extracts, and the elution profiles of plasma, urine and tumor extracts were slightly different. Lower molecular weight forms of hCG and its beta subunit were present in all urine samples. The significance of these heterogeneities remains to be elucidated.

Adult↗

Differential expression of glucose transporters in rabbit placenta: effect of hypercholesterolemia in dams.

Low birth weight is observed in rabbit offspring when maternal hypercholesterolemia is induced during gestation, but the related etiology is still unknown. Glucose is one of the most important substances during fetal development, and defect in glucose supply to fetus was related to pathophysiological mechanisms in intrauterine growth restriction. Thus, the aim of this work was to evaluate the impact of maternal hypercholesterolemia during rabbit gestation on the glucose metabolism and the routing of glucose transporters (SLC2 and SLC5 [previously known as GLUT and SGLT]) in placenta. In this study, maternal and offspring serum levels of glucose and insulin were evaluated for control and hypercholesterolemic groups, and the mRNA and protein expressions of placental SLCs were quantified by real-time RT-PCR and Western immunoblot, respectively. Our data demonstrate that maternal hypercholesterolemia during gestation: 1) induces offspring hypoglycemia; 2) does not modify the genetic and protein expressions of SLC2A1 and SLC2A4 (previously GLUT1 and GLUT4) in total placental extract; 3) downregulates the placental SLC5A1 (previously SGLT1) protein expression without affecting its mRNA levels; 4) impairs the translocation of SLC2A1 but not SLC2A4 from cytoplasmatic pool to the cell membrane surface. Then we assume that reduction of offspring birth weight in presence of maternal hypercholesterolemia may be related to the offspring's hypoglycemia and the reduction of the cell surface expression of placental SLC2A1.

Animals↗

Varying bioactive to immunoactive ratios of the human chorionic gonadotropin-like substance present in normal human tissues.

To further characterize the hCG-like substance found in normal nonpregnant human tissues, we compared the biological (B) and immunological (I) activities of the substance in extracts of 40 nontrophoblastic tissues and 7 placentas. B was measured in an in vitro mouse testicular interstitial cell bioassay, and I was measured in the beta hCG RIA. Highly purified hCG (CR 119) was used as a standard. B was detected in 92% of the nontrophoblastic nonpituitary tissues. Parallelism between serial dilutions of extracts and the hCG standard was found for 75% of the pituitary extracts, 86% of the placental extracts, and 53% of the other tissues. The correlation between B and I activities in the nontrophoblastic nonpituitary tissues was good (r = 0.8; P less than 0.001). Preincubation of the tissue extracts with anti-hCG serum before bioassay significantly reduced the B activity. There was wide variation in the B to I ratio between tissues and within the same tissues from different individuals. A B to I ratio less than 1 was found in 50% of the tissues, excluding placenta and pituitary, and may have been due to the presence of incomplete or altered hCG molecules, which are immunologically active but have reduced B activity.

Animals↗

Human placental lactogen transcriptional enhancer. Tissue specificity and binding with specific proteins.

Human placental lactogen (hPL) and growth hormone (hGH) are thought to be derived from a common ancestral gene and have similar nucleotide and amino acid sequences. Although the genes are similar in structure, they are expressed in different tissues. A transcriptional enhancer has been found 2.2 kilobases 3' of the hPL3 gene at the distal extreme of the hPL/hGH gene cluster. This enhancer is at least 20-fold more active in hPL-producing human choriocarcinoma JEG-3 cells than in non-hPL-producing cells. The enhancer is active when linked to either the hPL3 or SV40 promoter. We have localized the hPL enhancer to a 138-base pair (bp) region that retains tissue specificity in transient transfection assays. Gel mobility shift assays showed that the hPL enhancer interacted specifically with nuclear proteins from JEG-3 cells and placental tissue. Within the 138-bp enhancer, a 22-bp region overlapping a TEF-1 binding site was shown to be protected from DNase I digestion by placental and HeLa nuclear extracts. Placental protein(s) binding this region may be instrumental in tissue-specific activity of the hPL enhancer.

Amino Acid Sequence↗

Human placental cholinergic system.

The occurrence of acetylcholine (ACh)-like activity in human placenta, a tissue without innervation, has been known for more than 60 years. However, the non-neuronal functions of ACh in human placenta are not clearly understood. The components of the cholinergic system-ACh, choline acetyltransferase, acetylcholinesterase, butyrylcholinesterase, muscarinic receptors, and nicotinic receptors--in human placenta have been demonstrated by unequivocal methods. Primate placentae store and release ACh by mechanisms similar to those of nervous tissue. However, there are many gaps in our knowledge, which include: (a) endogenous quaternary ammonium compounds other than ACh in human placental extracts; (b) the specificity of placental enzymes; (c) the subtypes and structures of placental muscarinic and nicotinic receptors; and (d) the significance of placental alpha-bungarotoxin binding proteins, ACh receptor stimulation-cellular signaling by second messengers, and activation of immediate early target genes (C-fos, C-jun) encoding transcription factors. Several hypothetical non-neuronal functions of ACh in placenta have been postulated based upon available experimental evidence. These include: (a) regulation of blood flow and fluid volume in placental vessels; (b) opening and closing of trophoblastic channels; (c) induction of contractile properties to myofibroblasts; (d) facilitation of amino acid transport necessary for fetal growth across placenta; (e) release of placental hormones; and (f) modulation of the formation of myometrial and placental prostaglandins in human parturition. All of these roles are reasonable, and some of these roles mav turn out to be linked to one another to influence or maintain placental function.

Acetyl Coenzyme A↗

The transforming growth factor-ss superfamily cytokine macrophage inhibitory cytokine-1 is present in high concentrations in the serum of pregnant women.

Macrophage inhibitory cytokine-1 (MIC-1) is a recently described divergent member of the transforming growth factor-ss superfamily. MIC-1 transcription up-regulation is associated with macrophage activation, and this observation led to its cloning. Northern blots indicate that MIC-1 is also present in human placenta. A sensitive sandwich enzyme-linked immunosorbent assay for the quantification of MIC-1 was developed and used to examine the role of this cytokine in pregnancy. High levels of MIC-1 are present in the sera of pregnant women. The level rises substantially with progress of gestation. MIC-1 can also be detected, in large amounts, in amniotic fluid and placental extracts. In addition, the BeWo placental trophoblastic cell line was found to constitutively express the MIC-1 transcript and secrete large amounts of MIC-1. These findings suggest that the placental trophoblast is a major source of the MIC-1 present in maternal serum and amniotic fluid. We suggest that MIC-1 may promote fetal survival by suppressing the production of maternally derived proinflammatory cytokines within the uterus.

Adult↗

Secretion of corticotropin-releasing hormone by superfused human placental fragments.

Corticotropin-releasing hormone (CRH) immunoreactivity (IR) is present in the blood of women in the 3rd trimester of pregnancy and in placental extracts. We have used a placental fragment superfusion system to investigate the release of CRH from fresh placental tissue. Fragments of normal term placenta were mixed with Biogel P2, packed into minicolumns and superfused with carbogen-gassed Earles buffer at 37 degrees C. The rheology of the superfusion system was determined and the oxygen consumption of the superfused placental fragments indicated viability of the tissue preparation over a 5-hour time span. CRH IR in the eluate was measured by radioimmunoassay (RIA) using the 41 residue synthetic peptide human, rat CRH-41 (h, r CRH-41) as the standard, 125I labelled Tyr- h, r CRH as the tracer and rabbit anti-ovine CRH as the antibody. The sensitivity of the assay is 2 pM. Size exclusion chromatography on Sephadex G-50 of the placental column eluate displayed one major peak of CRH IR which co-eluted with that of h, r CRH. Placental fragment superfusate displayed potent CRH bioactivity as assessed by beta-endorphin secretion from ovine pituitary cells. Replacing the superfusing medium of the placental fragments with 45 mM KCl resulted in a prompt increase in the release of CRH IR. These results indicate that placental cells in vitro secrete a molecule of similar molecular weight, immunoreactivity and bioactivity to h, r CRH and that the rate of secretion may be regulated.

Animals↗

Fertility control through active immunization using placenta proteins.

Numerous studies have demonstrated that antibodies to placental proteins in a variety of species are capable of preventing or disrupting gestation. Early work in this area was primarily directed towards the passive immunization of rodents with heterologous antisera to whole placental extracts. Toxicity and renal damage often accompanied fertility inhibition. More recent studies reported less toxicity and a higher specificity of antibodies to reproductive function when anti-placental antibodies were absorbed with serum and extracts of non-reproductive organs. Few studies have been reported in which active immunization with placental proteins was employed. The most detailed studies of active immunization have employed highly purified placental hormones. Immunizations of rats and rabbits with human placental lactogen have resulted in marked reduction in reproductive function. Immunization of human females with chemically altered (hapten-coupled/ HCG resulted in the production of antibodies reacting with unaltered HCG and pituitary LH. These antibodies were capable of reducing the level of endogenous serum LH in pre- and post-menopausal women. The also altered the events of the menstrual cycle in premenopausal women. More specific inhibition of chorionic gonadotrophin has been obtained by immunization of baboons with the beta subunit of HCG. Antifertility effects without alterations in the menstrual cycle of female baboons immunized with the beta subunit of HCG have been reported. The antibodies produced in these animals reacted significantly with human LH in vitro. The possibility of using hormonal and non-hormonal placental proteins as antigens for the specific immunological inhibition of fertility remains.

Abortion, Spontaneous↗

The effect of manual removal of the placenta on post-cesarean endometritis.

OBJECTIVE: To determine if intraoperative glove change and placental delivery method affect the post-cesarean endometritis rate. METHODS: After informed consent, women who required cesarean were randomly assigned to one of four study groups: 1) no glove change plus manual placental extraction, 2) no glove change plus spontaneous placental delivery, 3) glove change plus manual extraction, and 4) glove change plus spontaneous delivery. Bilateral glove change by both primary and assistant surgeons occurred immediately after delivery of the newborn and before delivery of the placenta. External uterine massage and traction on the umbilical cord were performed to assist spontaneous delivery of the placenta. A first-generation cephalosporin was routinely administered after umbilical cord clamping for prophylaxis of post-cesarean endometritis. RESULTS: Of 760 women entered into the study, we included 643 who did not have intrapartum chorioamnionitis or cesarean hysterectomy. The four groups were comparable with respect to selected maternal and intrapartum characteristics, including maternal and gestational age, parity, presence of labor, and the presence and duration of membrane rupture. The postoperative endometritis rate was significantly higher in women whose placentas were extracted manually (31 versus 22%, P = .01). Operator glove change did not alter the incidence of endometritis (relative risk 1.0, 95% confidence interval 0.79-1.3). CONCLUSION: Manual extraction of the placenta is associated with a significantly greater risk of post-cesarean endometritis than that observed with assisted spontaneous placental delivery. Intraoperative glove change does not decrease post-cesarean endometritis.

Adult↗

Isolation of antibody to human placental alkaline phosphatase (PLAP) from extracts of human placentae.

PROBLEM: Human placental alkaline phosphatase (PLAP) is a unique placental antigen bound to the syncytiotrophoblast, which may be able to elicit a specific immune response in pregnancy. METHOD OF STUDY: Antibody to PLAP was purified from placental extracts by: a) acid elution of membrane vesicles; b) purifying complexes of PLAP with human antibody on monoclonal antibodies to PLAP followed by denaturation of the enzyme; and c) by denaturation of PLAP in placental extracts and purification of antibody to PLAP on PLAP columns. RESULTS AND CONCLUSIONS: Specific antibody to PLAP is present in placental extracts, and is mostly bound to placental membrane preparations. PLAP is therefore immunogenic in pregnancy and could serve as a useful monitor of pregnancy-specific immunological responses. Since a similar enzyme appears in some cancers, it is possible that the immunization against PLAP in pregnancy will help to protect against the development of ovarian and endometrial cancer (the 'fetal antigen' hypothesis).

Alkaline Phosphatase↗

Identification of a gonadotropin-releasing hormone-like factor in the rabbit fetal placenta.

The biological and immunological gonadotropin-releasing hormone (GnRH)-like activities in rabbit fetal placentas collected at Day 18 of gestation were investigated. Both crude and partially purified acid extracts of placental tissue were tested. A similarly prepared liver extract served as a control. Immunological GnRH-like activity, determined through a GnRH radioimmunoassay was 1.3-2.0 pg/mg protein for the crude placental extract, 7.1-9.2 pg/mg protein for the partially purified placental extract and was nondetectable for liver extract. Both the crude and partially purified placental extracts increased (P less than 0.01) luteinizing hormone (LH) release by dispersed rabbit pituitary cells, whereas the liver extract had no effect. The (Ac-D-p-Cl-Phe1,2, D-Trp3, D-Arg6, D-Ala10)-GnRH antagonist was used to determine whether the biological GnRH-like activity in the placental extract was mediated through GnRH receptors. All three doses of antagonist (10, 100 and 1000 ng) suppressed the biological GnRH-like activity in the placental extracts. Molecular sieve chromatography of the partially purified placental extract showed that the immunoreactive GnRH-like factor eluted in the same fractions as the GnRH standard. These data indicate that the rabbit fetal placenta has both immunological and biological GnRH-like activity.

Animals↗