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Biomedical subjects

P Florio

Publications and source records attributed to P Florio.

At least 73 records · Page 4Linked to original sources
PubMed1996

Corticotropin-releasing factor and its binding protein: maternal serum levels in term and preterm deliveries.

OBJECTIVE: The primary objective of this investigation was to evaluate whether maternal serum corticotropin-releasing factor levels during pregnancy were predictive of spontaneous preterm delivery. STUDY DESIGN: Maternal serum levels of corticotropin-releasing factor and its binding protein were measured from 20 weeks of gestation in a cross-sectional study of 396 asymptomatic women at high risk for preterm delivery. RESULTS: Gestational age-specific corticotropin-releasing factor levels were not consistently or substantially increased for preterm compared with term deliveries, whether preterm delivery was due to preterm labor or preterm premature rupture of membranes. The binding protein for corticotropin-releasing factor did not vary according to gestational age until term, when it dropped substantially. CONCLUSION: Serum corticotropin-releasing factor levels do not appear to be an important predictor of preterm birth in asymptomatic patients who subsequently have either preterm labor or preterm premature rupture of membranes. Nevertheless, the drop in the corticotropin-releasing factor binding protein level at term suggests that the bioavailability of corticotropin-releasing factor increases as parturition approaches.

Adult↗
PubMed1996

Corticotropin-releasing factor-binding protein: origins and possible functions.

Corticotropin-releasing hormone-binding protein (CRFBP) is a 37-kD protein of 322 amino acids, containing one putative N-glycosylation site and 11 cysteines, 10 of which remain in the mature molecule (298 amino acids) and result essential for the action. CRFBP protein gene has been cloned and mapped to the distal region of chromosome 13 and loci5q in the mouse and human genomes. CRFBP is the only example of a neuropeptide-binding protein. It is produced in human and rat brain, and in human liver and placenta. In brain, the central distribution of CRFBP shares some regional overlap with CRF receptor-bindings sites. Additionally, in hypothalamic and limbic structures, CRFBP has been identified in association with CRF-expressing cell groups. CRFBP has been also demonstrated in the human placenta and related membranes. Indeed, amniotic epithelium, chorionic cytotrophoblast, and maternal decidua also show intense positive CRFBP mRNA signals. Circulating CRFBP levels in healthy nonpregnant individuals show the same range values as in maternal plasma collected during the first and second trimesters of pregnancy. A rise in CRFBP levels at 30-35 weeks of pregnancy with a dramatic decrease at 38-40 weeks have been shown. At postpartum, CRFBP levels in maternal plasma reach the nonpregnant concentrations. Recombinant and native CRFBP neutralize the ACTH-releasing activity of human CRF in cultured pituitary or placental cells and, additionally, may block the activity of CRF on human pregnant endometrium prostaglandin release and on human myometrium contractility in vitro. These findings suggest that CRFBP may play a role in modulating the functions of CRF in human pregnancy.

Body Fluids↗
PubMed1996

Human placenta and fetal membranes express human urocortin mRNA and peptide.

Recently a new member of the corticotropin-releasing factor (CRF) family has been cloned and named urocortin. It has been localized in rat brain and to human chromosome 2. The present study investigated whether human placenta and related tissues express mRNA and immunoreactive urocortin. Using specific oligonucleotide primers, reverse transcriptase-polymerase chain reaction experiments were performed on total RNA isolated from human placenta and decidua collected both at early stage of gestation (8-11 weeks) and at term (39-40 weeks). In addition, experiments were also done on specimens of amnion and chorion collected at term. Independently from the gestational age, placental and decidual cells expressed urocortin mRNA, with a 145 bp DNA band corresponding to the expected length. The expression of urocortin mRNA was also found in amnion and chorion. Using specific antiserum and an immunoperoxidase technique, immunoreactive urocortin was then localized in syncytiotrophoblast cells and in some extent in cytotrophoblast cells of placental villi at term, as well as in fetal membranes and maternal decidua. The present findings revealed that human placenta and gestational related tissues express human urocortin gene and localize immunoreactive urocortin, supporting the concept that these tissues are capable of expressing a large number of neuroendocrine peptides.

Amnion↗
PubMed1996

High levels of corticotropin-releasing factor (CRF) are inversely correlated with low levels of maternal CRF-binding protein in pregnant women with pregnancy-induced hypertension.

Corticotropin-releasing factor-binding protein (CRF-BP) is suggested to play a role in modulating the activity of the hypothalamus-pituitary-adrenal axis during pregnancy, counteracting the actions of circulating or locally acting CRF. The aim of the present study was to evaluate whether maternal levels of CRF-BP and CRF are modified in pregnant women with a high risk of developing pregnancy-induced hypertension (n = 21). A group of nine patients developed the disease between 25-35 weeks gestation, and sequential blood samples were taken every 5 weeks throughout the pregnancy. As a control group, healthy pregnant women were studied (n = 9) using the same protocol; a group of women with pregnancy-induced hypertension (n = 5) was studied starting from the time of diagnosis. In a subgroup of patients (n = 10), CRF-BP and CRF levels were studied after 5 weeks of antihypertensive treatment. Levels of CRF-BP were determined using a specific RIA, whereas CRF was evaluated by a two-site immunoradiometric assay. In patients at risk, circulating levels of CRF-BP followed the same pattern as that in healthy controls, showing a significant decrease at term (36-40 weeks; P < 0.05). A significant and progressive increase in plasma CRF levels was observed in both groups of pregnant women; the highest values were found at term (P < 0.01). In the nine patients who developed pregnancy-induced hypertension, maternal levels of CRF-BP at the onset of signs and symptoms were lower than control values, and CRF levels were significantly higher at the onset of the disease (P < 0.01). Similarly, in these hypertensive patients studied at the time of hospitalization, CRF-BP levels were lower whereas those of CRF were higher than levels in healthy patients (P < 0.01). No effect of antihypertensive therapy on either CRF-BP or CRF levels was observed. The present study shows an inverse correlation between reduced plasma CRF-BP levels and increased CRF levels in the maternal circulation of patients with pregnancy-induced hypertension, and indicates that these hormonal changes do not occur before the onset of disease, suggesting that the measurement of these polypeptides in maternal plasma does not predict the development of hypertension.

Carrier Proteins↗
PubMed1995

Maternal plasma and placental immunoreactive corticotrophin-releasing factor concentrations in infection-associated term and pre-term delivery.

The present study aimed to investigate whether microbial invasion of the amniotic cavity affects maternal plasma or placental immunoreactive corticotrophin releasing factor (ir-CRF) concentrations in pregnant women with pre-term or term labour. A cross-sectional study was conducted collecting blood samples in: (1) women with pre-term labour and intact membranes (25-36 weeks), with or without microbial invasion of the amniotic cavity (subdivided into three groups: 1A, no microbial invasion of the amniotic cavity, delivery at term, n = 54; group 1B, delivery < 48 h, no microbial invasion of the amniotic cavity, n = 10; group 1C, delivery < 48 h, microbial invasion of the amniotic cavity, n = 8); (2) women at term, not in labour and without microbial invasion of the amniotic cavity (n = 15); (3) women in spontaneous active labour at term without (A) (n = 55) or with (B) (n = 16) microbial invasion of the amniotic cavity; and (4) healthy women not in labour at 25-36 weeks of gestation (n = 25). Specimens of trophoblast tissue were collected from pregnant women with pre-term labour (no microbial invasion of the amniotic cavity, n = 6; microbial invasion of the amniotic cavity, n = 4) or delivering at term (no microbial invasion of the amniotic cavity, n = 8; microbial invasion of the amniotic cavity, n = 4). A specific radioimmunoassay on acidic extracts of plasma or placental specimens was used.(ABSTRACT TRUNCATED AT 250 WORDS)

Amnion↗
PubMed1995

Hypertension in pregnancy: changes in activin A maternal serum concentration.

Human placenta is the major source of activin A in maternal circulation. The aim of the present study was to evaluate maternal activin A serum concentration in pregnant women with chronic hypertension (n = 14), pregnancy-induced hypertension (n = 10) or pre-eclampsia (n = 16). In the group of pregnant women with chronic hypertension and of healthy pregnant women (n = 10) activin A was measured in samples collected longitudinally throughout gestation. Using a specific two-site enzyme-linked immunosorbent assay, it has been possible to measure maternal serum activin A concentration. In addition, the effect of recombinant human activin A administration on mean arterial pressure and heart rate in female rats have been also investigated. Mean +/- SEM of maternal serum activin A concentration in pre-eclamptic women (57.4 +/- 28.3 ng/ml), was significantly higher than in women with pregnancy-induced hypertension (14.8 +/- 10.5 ng/ml), chronic hypertension (10.3 +/- 5.4 ng/ml) or healthy control women (9.2 +/- 9.4 ng/ml) (P < 0.01). Serum activin A levels evaluated 2 weeks after anti-hypertensive treatment were not significantly different in pre-eclamptic women. Moreover, when exogenous recombinant human activin A was administered in female rats arterial pressure or frequency of heart rate did not change. The present study showed that maternal serum activin A concentration is abnormally high in patients with pre-eclampsia. Thus, since the patients with chronic hypertension or pregnancy-induced hypertension have activin A concentration in the normal range of values, activin A may be a prognostic marker of hypertension in pregnancy.

Activins↗
PubMed1995

Steroid-protein interaction in human placenta.

Human placenta produces a large variety of bioactive substances with endocrine and neural competence: pituitary and gonadal hormones, hypothalamic-like releasing or inhibiting hormones, growth factors, cytokines and neuropeptides. The most recent findings indicate that locally produced hormones regulate the secretion of other placental hormones supporting a paracrine/autocrine regulation. In placental endocrinology, a particular relevance is played by steroid hormones. In fact, a specific gonadotropin-releasing hormone (GnRH)-human chorionic gonadotropin (hCG) regulation of placental steroidogenesis has been proposed as a placental internal regulatory system acting on steroids production from human placenta. In addition, activin and inhibin have been proposed as further regulatory substances of the synthesis and secretion of steroids; the addition of activin A to placental culture augments GnRH, hCG and progesterone, and this effect can be significantly reduced by the addition of inhibins. Finally, a steroid-steroid interaction is suggested by the evidence that placental estrogen has a positive role in the regulation of progesterone biosynthesis. Other steroid-protein interactions have been observed in human placenta. In fact, recent data indicate that progesterone inhibits placental corticotropin-releasing factor (CRF) and estrogens act on placental conversion of cortisol to cortisone, activating cortisol secretion by the fetal adrenal and enhancing fetal adrenal function with advancing gestation.

Animals↗
PubMed1995

Effect of corticotropin-releasing factor-binding protein on prostaglandin release from cultured maternal decidua and on contractile activity of human myometrium in vitro.

Human placenta and uterine tissues are sites of production and local action of corticotropin-releasing factor (CRF). The recent evidence that CRF-binding protein (CRF-BP), a protein that blocks CRF-induced pituitary ACTH release, is produced by placental tissues suggested the present study to investigate the effects of CRF-BP on prostaglandin release and contractile activity of myometrial strips. Primary cultures of decidual cells were prepared using tissue collected from healthy women undergoing cesarean delivery at term. Mechanical and enzymatic cell dispersions were carried out, and experiments were performed 24-28 h after cell plating. The prostaglandin E2 (PGE2) concentration in cultured medium was measured by RIA. Myometrial strips were obtained from the upper edge of the uterine incision during elective cesarean section at term. Dissected free of connective tissue, strips were mounted in a 30-mL two-chamber organ bath containing oxygenated Tyrode's buffer (37 C) and connected to a two-channel isometric smooth muscle transducer. Cultured decidual cells collected at term significantly increased the release of PGE2 in the presence of CRF (P < 0.01). The addition of CRF-BP did not significantly modify PGE2 release, but completely reversed the effect of CRF. When human myometrial strips were incubated in the presence of CRF and PGF2 alpha, a significant increase in contractile activity was observed (P < 0.01); preincubation with CRF-BP prevented the increased contractile activity induced by CRF. The present data show that CRF-BP is able to counteract the biological effect of CRF on human pregnancy endometrium and myometrium and suggest that CRF-BP may be a regulatory protein that plays a role in the local function of uterine tissues during pregnancy.

Animals↗
PubMed1994

Corticotropin-releasing hormone increases prostaglandin F2 alpha activity on human myometrium in vitro.

OBJECTIVE: Our purpose was to study the capability of synthetic corticotropin-releasing hormone to directly stimulate human myometrium and to modulate the activity of prostaglandins F2 alpha and E2. STUDY DESIGN: Strips from human myometrium were obtained from 127 elective cesarean sections at term. The in vitro effect of human rat corticotropin-releasing hormone on myometrial contractility has been studied in resting myometrial strips mounted in a two-chamber bath for isolated organs. Stimuli (corticotropin-releasing hormone, prostaglandins F2 alpha and E2, and oxytocin) were administered as one single dose in the perfusion chamber. In each experiment one myometrial strip was used as a control. RESULTS: Corticotropin-releasing hormone significantly increases (p < 0.01) the myometrial response to prostaglandin F2 alpha. The hormone neither has a direct inotropic effect nor is it able to enhance the effect of prostaglandin E2 and oxytocin on myometrial strips. CONCLUSION: The positive effect of corticotropin-releasing hormone on the myometrial response to prostaglandin F2 alpha adds new support to the theory that placental corticotropins may modulate the onset of labor.

Corticotropin-Releasing Hormone↗
PubMed1994

Local production and action of follistatin in human placenta.

The aim of the present study was to investigate the possible production, localization, and action of follistatin in human placenta, fetal membranes (amnion, chorion), and maternal decidua. Four different experimental approaches were used: 1) Southern blot analysis following reverse polymerase chain reaction to identify follistatin messenger RNA (mRNA) in tissue homogenates; 2) immunohistochemistry to localize immunoreactive (ir-) follistatin in the various intrauterine tissues; 3) measurement by RIA of ir-follistatin levels in culture medium of placental cells; and 4) possible action of follistatin on human CG (hCG) and progesterone release from cultured placental cells. Placental and decidual cells collected during first trimester or at term gestation express follistatin mRNA; fetal membranes (amnion, chorion) at term also express follistatin mRNA. Immunoreactive follistatin is localized in syncytial cells of placental villi at term as well as in large decidual cells, in amnion epithelium, and in chorionic cells. The placental secretion of follistatin has been confirmed by the evidence of measurable levels of ir-follistatin in the medium of cultured placental cells at term; the release is time dependent and is not modified by the addition of forskolin or progesterone. The addition of increasing doses of recombinant human follistatin does not significantly influence the release of hCG or progesterone from cultured placental cells, whereas the activin A-induced hCG and progesterone release are completely reversed. The present data showed that 1) human placenta, fetal membranes, and decidua express follistatin mRNA; 2) ir-follistatin is localized and released from placental cells at term; and 3) follistatin has a functional role in the local control system regulating placental hormone production.

Base Sequence↗
PubMed1993

Maternal decidua and fetal membranes contain immunoreactive neuropeptide Y.

The aim of the present study was to evaluate whether the various intrauterine tissues contain immunoreactive neuropeptide Y (NPY). Previous observations showed that human placenta produces NPY and that it may play a local role. Using a polyclonal NPY antiserum and an immunofluorescent technique, sections of maternal decidua, amnion and chorion collected from a pregnant women at parturition were studied. An intense positive staining for NPY was observed in epithelial amnion cells and in chorionic cytotrophoblast. Some of the maternal decidual cells showed a weaker signal of immunoreactive NPY. In evaluating whether NPY may coexist with other hormones in these tissues, adjacent slices of decidua, amnion and chorion were stained with activin beta B subunit antiserum. In the various tissues a relevant number of cells showed positive signals for both NPY and activin. The present findings showed that the various intrauterine tissues contain NPY and that in a large number of cells of amnion, chorion and decidua the neuropeptide is colocalized with immunoreactive activin. In view of the physiological implications of NPY in the regulation of uterine contractility and of placental hormonogenesis, the present findings indicate a large distribution of NPY in the various intrauterine tissues.

Activins↗
PubMed1992

Effect of naltrexone treatment on the treadmill exercise-induced hormone release in amenorrheic women.

The effect of an acute physical stress on hormone secretions before and after a 10-day naltrexone treatment in untrained healthy and amenorrheic women was investigated. Plasma levels of pituitary (LH, FSH, prolactin, GH, ACTH, beta-endorphin) and adrenal (cortisol, androstenedione, testosterone) hormones were measured at rest and in response to 60 min of physical exercise. The test was done both before and after a 10-day naltrexone (50 mg/day) treatment. Graded levels of treadmill exercise (50, 70 and 90% of maximal oxygen uptake (VO2) every 20 min) was used as physical stressor. While mean +/- SE plasma LH levels in control women were higher than in amenorrheic patients and increased following the naltrexone treatment (p < 0.01), no significant differences of basal plasma hormonal levels were observed between amenorrheic and eumenorrheic women, both before and after naltrexone treatment. Physical exercise at 90% VO2 induced a significant increase in plasma GH, ACTH, beta-endorphin, cortisol, androstenedione and testosterone levels in controls before naltrexone treatment (p < 0.01). The mean increase in plasma androstenedione and testosterone levels in control women was significantly higher after naltrexone treatment (p < 0.01). In amenorrheic patients before naltrexone, physical exercise induced an increase in plasma prolactin and GH levels, but not in plasma ACTH, beta-endorphin, cortisol, testosterone and androstenedione. After naltrexone treatment, the exercise induced a significant plasma ACTH, beta-endorphin and cortisol levels, while the increase of plasma prolactin levels was significantly higher than before treatment (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗