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PubMedDate not supplied

Multiple forms of rat placental lactogen-II (rPL-II): purification and partial characterization of rPL-II.

The present study was designed to develop a procedure for purifying rPL-II and a homologous radioimmunoassay (RIA) for rPL-II. Molecular profiles of rPL-II were also investigated in tissue and plasma. rPL-II was purified 3,780-fold, based on its radioreceptor assay (RRA) activity compared to ovine prolactin (0PRL), from the placenta of day 18 pregnant rats using ammonium sulfate precipitation and chromatography on phenyl-Sepharose, DEAE-TOYOPEARL 650S, AF-chelate TOYOPEARL 650M and Sephadex G-100. Electrophoretic analysis on SDS gel revealed molecular weight heterogeneity of purified rPL-II, which consisted of three proteins; a major form with a molecular weight of 20.0 K and two minor forms with molecular weights of 20.6 K and 21.0 K under non-reducing conditions. One of the minor forms of rPL-II observed under non-reducing conditions disappeared with 2-mercaptoethanol treatment and the rest of the hormones migrated as 24.5 K and 25.0 K molecular weight species, suggesting that it is a cleaved form of rPL-II. Purified rPL-II displaced 125I-labelled oPRL from binding sites on rabbit mammary gland membranes in a dose-dependent manner. rPL-II and rPRL were, respectively, 21 and 2 per cent as effective as oPRL in the displacement. Antibody to purified rPL-II was raised in rabbits and a homologous RIA for rPL-II was developed. No displacement was observed with rPRL, rGH, oPRL, and other pituitary hormones up to 1,000 ng/ml. Molecular profiles of rPL-II in the placental tissue and plasma from day 18 pregnant rats were examined by gel chromatography on Sepharcryl S-300 HR and by Western blotting. Chromatography of the placental extracts revealed a single peak, which accounted for 86 per cent of the total RIA activity. Anti-rPL-II antiserum detected proteins of at least three molecular sizes as monomeric forms with molecular weights of 20.0, 20.6, and 21.0 K in the non-reducing placental extracts. One of them disappeared with 2-mercaptoethanol treatment and other two proteins had molecular weights of 24.5 and 25.0 K, indicating monomeric heterogeneity of rPL-II in the tissue. The elution profile of day 18 plasma in RIA activity gave two major peaks; the first, eluting just after the void volume (approximate molecular weight of 530 K) accounted for 35 per cent of the total RIA activity, and the second coinciding with the same elution volume as the monomeric form in the placental extract constituted about 26 per cent of the total RIA activity.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1991

Molecular cloning and expression of rat placental lactogen-Iv, a variant of rPL-I present in late pregnant rat placenta.

Late pregnant rat placenta was found to contain a messenger RNA (mRNA) that encodes an additional member of the prolactin-growth hormone family. This polypeptide was detected by hybridization of complementary DNA (cDNA) for rPL-I to a 1 kilobase mRNA transcript in late pregnant rat placenta. A cDNA clone for the new polypeptide was isolated from a phage lambda-gt10 library containing cDNA synthesized from day 18 rat placental mRNA. Sequencing of the day 18 cDNA clone revealed that it was most closely related structurally to rPL-I and at the amino acid terminal was identical to the rPL-I variant (rPL-Iv). The sequence of rPL-Iv (223 amino acids) is 85% homologous to rPL-I (230 amino acid). There are 71 base pair changes (85% nucleotide homology) between rPL-Iv and rPL-I which are not confined to any specific region of the molecule and which result in 36 amino acid changes. In vitro translation of rPL-Iv mRNA produced by transcription of the cDNA template yielded a 26 kilodalton polypeptide, the size of the expected precursor protein. In situ hybridization studies indicated that mRNA for rPL-Iv was present primarily in cytotrophoblasts of the basal zone as early as day 15 of gestation with some hybridization in a few giant cells as well.

Amino Acid Sequence↗
PubMed1991

Gestational profiles of rat placental lactogen-II (rPL-II) and growth hormone (GH) in maternal and fetal serum, amniotic fluid, and placental tissue.

Rat placental lactogen-II (rPL-II) and growth hormone (rGH) in maternal and fetal serum, amniotic fluid, and placental tissue were measured by a homologous radioimmunoassay during the last half of pregnancy. rPL-II appeared first in maternal circulation and the placental tissue on day 11 of pregnancy. The maternal serum rPL-II concentration increased progressively and reached the peak value (684 +/- 76 ng/ml) on day 19, and declined thereafter up to term. rPL-II content in the tissue had a similar pattern to the maternal serum profile of rPL-II, while its concentration in the tissue increased dramatically on day 12 and remained high until day 19. Fetal serum rPL-II was detected on days 17 and 18, though its concentration was much lower (ranged between 3-10 ng/ml) than that of maternal serum. rPL-II in amniotic fluid was also detectable only on days 12-14 of pregnancy, and the peak value on day 13 was 22% of the maternal serum rPL-II concentration. The rGH concentration increased gradually as pregnancy advanced with a decline on the day before parturition. Although rGH in fetal serum increased on day 20 with a decline on the following day, it was slightly detectable in amniotic fluid on the last two days of pregnancy. The molecular profile of rPL-II in amniotic fluid and maternal serum of day 13 pregnant rats were examined by Western blotting. Anti-rPL-II serum detected two proteins with molecular weights (mol wt) of 19.5K and 20.5K in amniotic fluid and one protein with a mol wt of 20.5K in maternal serum under nonreducing conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Amniotic Fluid↗
PubMed1989

Ventricular fibrillation detection by autocorrelation function peak analysis.

UNLABELLED: The use of reliable automatic ventricular fibrillation (VF) recognition techniques is critical in performing external automatic defibrillation. The authors' objective was to develop a method to detect VF and life-threatening arrhythmias, based on direct and simple peak analysis of the autocorrelation function (ACF). This method may differentiate between fibrillating and nonfibrillating rhythms, and in the first case between "course" and "fine" VF. ECG records during ventricular tachycardia (VT) and VF were obtained from patients during cardiac surgery. Segments 4 sec long were selected from tapes and digitized at 200 Hz, then split into three groups (VT, VF regular waveform, and VF irregular waveform). The positive peak P(j) of the ACF was defined as the maximum value between two function zeros, and RPL(j) represents the relation between P(j) and twice their own standard error. Parameter TR(1) was defined as the relation between P(1) width and the time of occurrence. ACFs were computed for the entire sample; RPL(j), D(j) = RPL(j) - RPL(j + 1), and TR(1) were calculated for every record. The results indicate that: (A) If RPL(1) greater than 1.2 and (1.6 greater than or equal to RPL(2) greater than 1) and (RPL(3) greater than 0.6 and D(1) greater than 0), then consider VT; (B) If (1.2 greater than or equal to RPL(1) greater than or equal to 1) and (1 greater than or equal to RPL(2) greater than or equal to 0.9) and D(1) greater than 9, then consider VT or VF with very regular waveform; (C) If (RPL(1) less than or equal to 1.8 and RPL(2) less than 0.9) or (RPL(2) less than 1.5 and D(1) less than 0) or RPL(3) less than 0.6, then consider VF. When 0.3 less than TR(1) less than 0.8, the underlying arrhythmia is VF or VT, and when it is outside this range, it is likely to be a supraventricular rhythm. CONCLUSIONS: (A) RPL(j) parameters have a high specificity for discriminating between VT and VF. The method is reliable and simple. (B) The TR(1) parameter together with RPL(j) allow discrimination between supraventricular tachycardias and ventricular originated tachyarrhythmias. (C) Further analysis must be done using problem-oriented arrhythmias data bases.

Data Interpretation, Statistical↗
PubMed1990

Molecular cloning and expression of rat placental lactogen-I complementary deoxyribonucleic acid.

A full-length cDNA clone for rat placental lactogen I (rPL-I) has been isolated from a phage lambda gt11 library containing cDNA synthesized from day 11 rat placental mRNA. By Northern blot analysis the rPL-I cDNA clone hybridizes to a 1.0-kilobase placental mRNA and appears as early as day 10 of gestation. Maximal expression of this mRNA was observed in day 11 and 12 placenta, and faint hybridization of the rPL-I cDNA was also detected in day 18 to term placenta. In contrast, the mouse clone hybridized to mRNA for mouse PL-I (mPL-I) only in day 10 mouse placenta (9). In vitro translation of rPL-I mRNA produced by transcription of the cDNA template yielded a 27-kDa polypeptide the size of the expected precursor protein which was immunoprecipitated by a monoclonal antibody to rPL-I. The rPL-I cDNA nucleotide sequence has been determined. The sequence is very similar to that for mPL-I and contains an open reading frame encoding a polypeptide of 230 amino acids compared to 224 for mPL-I. Comparison of the predicted primary translation product of rPL-I mRNA with that of mPL-I mRNA revealed that rPL-I shares 73% identity to mPL-I at the amino acid level. The predicted rPL-I protein shares 41% amino acid identity with rPL-II precursor, 24% with rat prolactin-like protein A, 26% with rat prolactin-like protein B, and 31% with rat PRL. In situ hybridization studies indicated that mRNA for rPL-I was present in a few rapidly dividing cells as early as day 8 of gestation, and by day 9 could be localized to giant cells which surround the conceptus.

Amino Acid Sequence↗
PubMed1978

Genetic control of resistance to Marek's disease.

Various MD-resistant and MD-susceptibel lines of chickens were challenged with the RPL-1 cell line, an MD tumor cell line which is capable of growth both in vivo and invitro. Birds which possessed the B21 allele, an allele shown to be associated with MD resistance, were also resistant to the growth of the RPL-1 tumor. Lines of chickens which possessed B alleles associated with susceptibility to MD were also very susceptible to the growth of the RPL-1 tumour. The growth of RPL-1 cells can therefore be used as a marker of B21-associated resistance to MD. In contrast, lines of chickens which differ in susceptibility to MD, due to allelic differences at a non-B genetic locus (or loci), did not differ with respect to their capacity to reject RPL-1 cells. We suggest that this might indicate that different mechanisms might be operative in B-associated versus non-B-associated resistance to MD. In addition, females were more susceptible than males to RPL-1 challenge and the RPL-1 tumour demonstrated a predilection for growth in the ovary.

Alleles↗
PubMed2025

Genotyping of natural killer cell immunoglobulin-like receptors in human early reproductive losses.

Genotyping of killer cell immunoglobulin-like receptors (KIR) of NK-cells was performed in 634 women with early pregnancy losses (EPL), including 158 women with recurrent implantation failure (RIF) after at least three IVF cycles, and 110 women with at least two intrauterine pregnancy losses characterized by clinically confirmed retention of a non-viable fetus in the uterus without spontaneous miscarriage, defined as recurrent pregnancy loss (RPL). The control group consisted of 431 women with at least two healthy children. In the RIF, a significant shift in the frequency of KIR-genotypes was observed compared with both the control and the RPL groups. A significantly higher frequency of the KIR-AA genotype was observed in the RIF group compared to the control group (&#x3c7;&#xb2; = 26.78; p&#x202f;<&#x202f;0.0001; OR = 2.7) and the RPL group (&#x3c7;&#xb2; = 15.83; p&#x202f;<&#x202f;0.0001; OR = 2.86). Analysis of the frequency of full-length/deletion alleles of KIR2DS4 among AA genotype carriers showed an increased frequency of the 2DS4-del in the RIF compared with the RPL and control groups. A significantly higher frequency of the cenAA was also observed in RIF compared with the control (&#x3c7;&#xb2; = 20.10; p&#x202f;<&#x202f;0.0001) and the RPL(&#x3c7;&#xb2; = 12.05; p&#x202f;<&#x202f;0.005). The significantly increased frequency of the KIR-AA genotype with predominance of deletion KIR2DS4 alleles, along with the elevated frequency of the cenAA in RIF, may indicate insufficient NK-cell activation at the stage of embryo implantation. These findings suggest different etiological mechanisms for RIF and RPL.

Humans↗
PubMed1990

Interactions between endogenous virus loci ev6 and ev21. 1. Immune response to exogenous avian leukosis virus infection.

The effects of ev6, ev21, sex, and hatch, were studied with respect to avian leukosis virus (ALV) viremia, cloacal shedding, and antibody response among RPL-40 virus-infected White Leghorns that carried ev6 and ev21 in all combinations. Among the four possible ev genotypes, chickens that carried only ev21 were the most immunologically tolerant to RPL-40 infection. Incidence of RPL-40 viremia was lowest among hatchmates that lacked both ev genes. Analysis of variance indicated significant interactions between ev6 and ev21 with respect to all responses. Among ev21+ slow-feathering (SF) chickens, the incidence of viremia and shedding of RPL-40 was reduced in the presence of ev6 when compared with ev6- hatchmates. Conversely, among ev21- rapid-feathering (RF) chickens, ev6 significantly enhanced the incidence of RPL-40 viremia when compared with ev6- hatchmates. The endogenous virus, ev6, markedly reduced recovery of the endogenous virus (EV21) from plasmas of slow-feathering chickens. When both flocks were terminated at 21 wk of age, significantly more ev21+ SF females had died from or developed RPL-40-induced tumors than ev21- hatchmates.

Animals↗
PubMed1988

Hyporeactivity to mitogens of retroplacental blood lymphocytes in human pregnancy.

Retroplacental blood lymphocytes (RPL) obtained from women without complications at the term delivery were studied for proliferative response to mitogens and surface phenotype and were compared with autologous peripheral blood lymphocytes (PBL). Proliferation of RPL induced by phytohemagglutinin (PHA) was significantly lower than that of PBL in 11 of 13 cases. Also RPL proliferated poorly in response to concanavalin A (Con A) in 8 of 10 cases. On the other hand, flow cytometry analysis of T cell subsets revealed that RPL contain comparable or higher number of CD3+ cells and CD4+ cells and similar numbers of CD8+ cells as compared with PBL in most cases. These results indicate that T cell proliferative response in retroplacental space is impaired, which could be due to a functional defect of RPL.

Antigens, Surface↗
PubMedDate not supplied

Reduction of interleukin-2-receptor expression on retroplacental blood lymphocytes in human pregnancy.

Retroplacental blood lymphocytes (RPL) in human pregnancy were studied for proliferative response induced by recombinant interleukin-2 (rIL-2) and anti-Tac positive cells before and after PHA stimulation for 24 hr and compared with peripheral blood lymphocytes (PBL) of the same donor. Proliferation of RPL induced by IL-2 was significantly lower than that of PBL in all of six cases. In addition, flow cytometry analysis of IL-2 receptors (IL-2R) revealed that IL-2R expression of RPL after stimulation with PHA for 24 hr was significantly less than that of PBL in three of four cases and that RPL showed significantly fewer IL-2R than PBL even at resting state in one case. These results suggest that RPL seem likely to be composed of reduced numbers of lymphocytes bearing IL-2R of non-Tac protein and to have impaired capacity for the acquisition of high-affinity receptors for IL-2.

Female↗
PubMed1988

Biochemical comparison of fibroblast populations from different periodontal tissues: characterization of matrix protein and collagenolytic enzyme synthesis.

To compare the expression of extracellular matrix components by fibroblasts from different periodontal tissues, rat molar periodontal ligament fibroblasts (RPL) and rat gingival fibroblasts (RGF) were isolated and cultured from individual animals. Pulse-chase experiments using [35S]methionine as a precursor revealed that confluent populations of early passage cells of both cell types synthesized similar amounts of collagen, fibronectin, and SPARC/osteonectin. Qualitative and quantitative differences were apparent in the relative proportions of type III collagen, in the rates of procollagen processing, and in the synthesis of a small number of unidentified proteins observed by sodium dodecyl sulphate--polyacrylamide gel electrophoresis. Collagen constituted 24-26% of the radiolabelled proteins secreted by both cell types, type I being the predominant collagen, with lower amounts of type III (3-8% RGF, 8-18% RPL) and type V (approximately 1%) collagens. Procollagen processing in the culture medium of RPL cells was more rapid than for RGF cells, but was increased in multilayered cultures of both RPL and RGF. In multilayered cultures, collagen TCA fragments, indicative of tissue collagenase activity, were also identified. Active and latent tissue collagenases and a latent form of a novel collagenolytic enzyme (matrix metalloendoproteinase-V) that cleaves native TCA fragments were demonstrated in these cultures. Addition of either concanavalin A (10(-6) M) or retinoic acid (10(-5) M) to the culture medium stimulated the secretion of the latent collagenolytic enzymes. Collagenase inhibitor was also synthesized by both RGF and RPL cells. SPARC/osteonectin, a 40-kilodalton glycoprotein, represented 0.5-1.0% of the secreted radiolabelled proteins of both cell types.

Animals↗
PubMed1990

Interactions between endogenous virus loci ev6 and ev21. 2. Congenital transmission of EV21 viral product to female progency from slow-feathering dams.

The influence of the endogenous virus ev6 on congenital transmission of EV21, the infectious viral product encoded by locus ev21, and the immune response to exogenous avian leukosis virus (ALV) infection was studied in rapid-feathering (RF) female progeny from four classes of slow-feathering (SF) (ev21+ and RF (ev21-) dams with and without ev6. Apart from transmitting infectious EV21 and ev6 to progency, dam ev genotype did not influence the immune response or shedding of RPL-40. The endogenous virus envelope glycoprotein encoded by ev6, however, completely restricted shedding and congenital transmission of infectious endogenous virus EV21, from SF dams. After 19 wk of exposure to ALV strain RPL-40 infected cage mates, only 11% of the congenitally infected female progeny mounted neutralizing antibodies against RPL-40, whereas 73% of their noncongenitally infected sisters seroconverted. More ev6+ female progeny, however, were shedders of RPL-40 and developed tumors than ev6- sisters. Among progeny from the four classes of dams, EV21 congenitally infected hens had the highest incidence (31%) of RPL-40-induced tumors.

Animals↗
PubMed2026

IVF patient subgroups benefit from preimplantation genetic testing for aneuploidy: a prospective multicentre cohort study.

RESEARCH QUESTION: Can preimplantation genetic testing for aneuploidy (PGT-A) improve the ongoing pregnancy rate per transfer and reduce miscarriage rate in patients with advanced maternal age (AMA), recurrent implantation failure (RIF), recurrent pregnancy loss (RPL), or both, without affecting cumulative pregnancy rate? DESIGN: Prospective cohort study of 260 patients undergoing PGT-A aged 36 years or over (AMA group), with a history of three or more blastocyst transfers without birth (RIF group), two or more early pregnancy losses (RPL group), or all. Trophectoderm biopsy was conducted day 5 or 6, and comprehensive chromosome screening was used for PGT-A before single frozen embryo transfer (PGT-A-FET). A total of 3060 patients undergoing single conventional frozen embryo transfer (FET) served as a historical reference group. RESULTS: Patients had increased odds of positive serum beta-HCG after PGT-A-FET compared with FET in the AMA (OR 1.53, 95% CI 1.06 to 2.21) and RIF (OR 2.11, 95% CI 1.41 to 3.14) groups. The PGT-A-FET group significantly improved the odds of ongoing pregnancy in the AMA (OR 2.20, 95% CI 1.52 to 3.18), RIF (OR 3.96, 95% CI 2.60 to 6.04) and RPL (OR 2.81, 95% CI 1.52 to 5.21) groups. The odds of pregnancy loss were significantly reduced with PGT-A-FET in the AMA (OR 0.36, 95% CI 0.21 to 0.64), RIF (OR 0.10, 95% CI 0.04 to 0.26) and RPL (OR 0.14, 95% CI 0.04 to 0.53) groups. Cumulative pregnancy rate did not differ between PGT-A and conventional cycles (RR 0.94, 95% CI 0.80 to 1.10). CONCLUSIONS: PGT-A improved the odds of ongoing pregnancy and reduced the odds of pregnancy loss in all groups. The cumulative pregnancy rate did not differ between PGT-A and conventional cycles. Findings should be interpreted in the context of the observational design.

Adult↗
PubMed1991

Isolation and preliminary characterization of Escherichia coli mutants resistant to lethal action of the bacteriophage lambda P gene.

Both spontaneous and NTG-induced mutants of Escherichia coli 594 insensitive to the lethal action of lambda P gene were isolated and called rpl (resistant to P lethality). These mutants were of two types, showing different phenotypes. On type I rpl mutants, lambda cl- and lambda v1v3 did not plate, while lambda vir, lambda cl- c17, lambda imm434, and lambda imm21 did; plasmid pMR45 carrying the lambda P gene could not complement lambda imm21P- phage in type I mutants. On the other hand, the type II rpl mutants support the growth of all the above phages including lambda cl-. Neither type of rpl mutation affects growth of the bacteria.

Bacteriophage lambda↗
PubMed1988

Depression of proliferative response to fetal lymphocytes of retroplacental blood lymphocytes in human pregnancy.

Retroplacental blood lymphocytes (RPL) in human pregnancy were studied for proliferative response to related fetal lymphocytes and it was compared with that of peripheral blood lymphocytes (PBL) of the same donor. RPL proliferated poorly to related cord blood lymphocytes in 9 of 10 cases when compared with autologous PBL. RPL also showed lower proliferative response to unrelated adult lymphocytes in 7 of 12 cases. Proliferation of RPL was weaker to related cord blood lymphocytes than to allogeneic adult lymphocytes. These results indicate that the response of T cells at feto-maternal interface is impaired, especially to fetal antigens.

Female↗