John Tziotis

Concentrations of angiogenic factors in follicular fluid and oocyte-cumulus complex culture medium from women undergoing in vitro fertilization: association with oocyte maturity and fertilization

OBJECTIVE To determine the concentration of angiogenic factors (vascular endothelial growth factor [VEGF], basic fibroblast growth factor [bFGF], and angiogenin) in the follicular fluid (FF) and oocyte-cumulus complex culture medium (CM) of women undergoing IVF and to investigate the association of the concentrations with the maturity and fertilization of the oocyte. DESIGN Prospective study. SETTING Academic tertiary-care institution. PATIENT(S) IVF patients with unexplained or tubal factor infertility. INTERVENTION(S) Analysis of VEGF, bFGF, and angiogenin FF and CM concentrations. MAIN OUTCOME MEASURE(S) Oocyte maturity and fertilization and FF and CM angiogenic factor concentrations. RESULT(S) VEGF, bFGF, and angiogenin were determined in FF and CM. FF angiogenin concentrations were significantly higher when the oocyte was mature versus immature. CM VEGF concentrations were significantly higher when the oocyte was nonfertilized versus fertilized. Positive correlations were observed between angiogenic factors in CM. CONCLUSION(S) VEGF, bFGF, and angiogenin (determined for the first time) are secreted in the FF and CM. Elevated CM VEGF concentrations, probably implying oocyte-cumulus complex hypoxia, are negatively associated with oocyte fertilization. Elevated FF angiogenin concentrations are positively associated with oocyte maturity, possibly indicating angiogenins biological role beyond neovascularization.

Risk factors predisposing to fetal loss following a second trimester amniocentesis

Objective To examine the influence of possible risk factors on fetal loss rate following amniocentesis.

Changes in serum levels of vascular endothelial growth factor in males and females throughout life.

Objectives: To study serum levels of vascular endothelial growth factor (VEGF), a potent angiogenic factor, during distinct periods of the female life span and compare them with corresponding levels of age-matched males. It is hypothesized that VEGF might be increased at periods of enhanced angiogenesis. Methods: Venous blood was drawn from healthy females (n = 59) and males (n = 53) divided into six groups: fetuses (cord blood), neonates, children, adults (same females in the proliferative and secretory phases of their menstrual cycle), pregnant, and elderly (postmenopausal). Serum VEGF levels were measured by an enzyme immunoassay. Results: Females showed 49% higher serum VEGF levels than males (t = 2.74, P = .01). Cord and neonatal blood levels were significantly increased compared with those of adults (t = 2.41, P = .02, and t = 5.81, P = .0001, respectively). All female age groups presented higher serum VEGF levles than the group of women in the proliferative phase of the cycle; nevertheless, VEGF levels in the secretory phase did not differ (t = 1.85, P = .07). Conclusions: Serum VEGF levels are higher in females than in males and during life periods characterized by enhanced growth and development, implying increased rates of angiogenesis.

Serum Levels of Basic Fibroblast Growth Factor and Vascular Endothelial Growth Factor in Children and Adolescents with Type 1 Diabetes Mellitus

Diabetes mellitus is characterized by microangiopathy and increased angiogenic response in various organs. Basic fibroblast growth factor (bFGF) as well as vascular endothelial growth factor (VEGF) are both angiogenic and are involved in vascular endothelial cell growth. The purpose of this study was to determine serum levels of bFGF and VEGF, in children and adolescents (youngsters) with type 1 diabetes mellitus, and correlate them with parameters reflecting the severity of the disease. Forty diabetic youngsters without clinical evidence of complications were compared with 30 healthy control subjects (mean age ± SD, 14.3 ± 3.6 and 13.8 ± 3.6 y, respectively). Diabetes duration and metabolic control (expressed by glycosylated Hb) were (mean ± SD) 6.2 ± 3.8 y and 9.6 ± 1.8%, respectively. bFGF and VEGF (pg/mL) were measured in serum samples by enzyme immunoassays, and both were not significantly different between the type 1 diabetes mellitus and the control group (p = 0.952 and p = 0.559, respectively). Restricting the analysis to the type 1 diabetes mellitus group, neither the duration nor the metabolic control of the disease showed any correlation with bFGF and VEGF serum levels, whereas a significantly positive correlation was found between the two examined angiogenic factors both in the diabetic (r = 0.3464, p = 0.025) and the control group (r = 0.4619, p = 0.0013). In conclusion, serum levels of bFGF and VEGF were not found to vary significantly in diabetic youngsters in relation to controls and had no correlation with the duration and metabolic control of the disease. Nevertheless, a positive correlation was found between these two angiogenic factors both in the type 1 diabetes mellitus and the control group.

Adhesion molecules expression in the placental bed of pregnancies with pre-eclampsia

Objective To compare the expression of intercellular adhesion molecule‐1 (ICAM‐1), vascular cell adhesion molecule‐1 (VCAM‐1), platelet endothelial cell adhesion molecule‐1 (PECAM‐1) and E‐selectin in placental bed biopsies (endothelium of spiral arteries as well as trophoblastic cells) from normal and pre‐eclamptic pregnancies

Angiogenic factors in the perinatal period: diversity in biological functions reflected in their serum concentrations soon after birth.

Abstract: These studies investigated whether serum levels of the angiogenic factors angiogenin, basic fibroblast growth factor (bFGF), and vascular endothelial growth factor (VEGF) change soon after birth due to the elimination of the placenta and to diminished angiogenic but increased adaptational demands in extrauterine life. Also investigated was whether serum levels correlate with sex, birth weight, or mode of delivery. Serum from healthy mothers and their healthy full‐term infants at birth (umbilical cord, UC), day 1 (N1) and day 4 (N4) postpartum was analyzed by enzyme immunoassays. Angiogenin levels were higher in maternal serum and rose significantly from UC to N1 and N4, possibly because of the elimination of the placenta, which produces an angiogenin inhibitor. bFGF and VEGF maternal levels were lower than fetal and neonatal ones. Although neonatal bFGF levels did not differ from fetal levels, possibly reflecting diminished angiogenesis ex utero, VEGF levels increased in neonatal serum, possibly signifying adaptational demands. Neither factor depended on sex, mode of delivery, or birth weight. Thus, significant differences from normal reference values of the studied factors might reflect ill‐defined situations of the placenta and fetus/newborn serving as early diagnostic markers.

Gene analysis of the N-terminal region of the estrogen receptor alpha in preeclampsia

Alterations in the NH(2)-terminal region of the estrogen receptor alpha (ERalpha) gene expressed in placental bed tissue may be implicated in the development of preeclampsia, the pathogenesis of which involves the spiral arteries. Therefore, mutations and polymorphisms on exons 1 and 2 of the gene encoding ERalpha were studied. Placental bed biopsies were taken from 20 healthy, normotensive pregnant women and 16 preeclamptic patients. DNA was extracted from the tissue and exon 1 and exon 2 were amplified by PCR prior to denaturing gradient gel electrophoresis analysis or to single stranded conformational polymorphism analysis. In exon 1, a codon 10 polymorphism, either homozygous for the wild type gene, homozygous for the mutant type gene, or heterozygous, was revealed in both patients and healthy individuals. A codon 87 polymorphism, homozygous for the wild type gene, was detected in both groups. No mutations or polymorphisms were found in exon 2. The allele distribution for either codon 10 or 87 between patients and healthy individuals showed no significant differences. In conclusion, genetic alterations in the NH(2)-terminal region of the ERalpha molecule are not correlated with preeclampsia.

Heparin-binding angiogenic factors (basic fibroblast growth factor and vascular endothelial growth factor) in early neonatal life.

This study investigated whether serum levels of the potent angiogenic factors basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF), which are abundantly produced in utero by the placenta and fetal tissues, change after birth at term, consequent to diminished angiogenic but increased adaptational demands in extrauterine life. Moreover, whether serum levels of the above factors correlate with sex, birth weight, or mode of delivery was also evaluated. One milliliter of blood was drawn from 30 healthy, appropriate for gestational age, full-term infants on d 1 (N1) and 4 (N4) postnatally. In 10 of the above cases maternal and umbilical cord blood samples were also drawn. Serum was analyzed by enzyme immunoassays, using commercial kits. Levels of bFGF and VEGF were significantly lower in maternal serum than in umbilical cord (p = 0.02 and 0.036, respectively) or N1 (p = 0.009 and 0.006, respectively) and N4 serum (p = 0.009 and 0.006, respectively). Levels of bFGF in umbilical cord serum did not differ significantly from those in N1 and N4. In contrast, levels of VEGF rose in N1, differing significantly from levels in umbilical cord serum (p = 0.008). Both factors did not change from N1 to N4. Neither bFGF nor VEGF serum levels depended on sex, mode of delivery, or birth weight. In conclusion, bFGF levels in neonates do not differ from levels in fetuses, possibly reflecting diminished angiogenesis in extrauterine life, which already has started in utero. On the contrary, neonatal levels of VEGF rise significantly after birth, possibly signifying adaptation demands, in addition to angiogenesis, as VEGF is also considered a regulator of normal function.

Evidence for a suppression of apoptosis in early postnatal life

Background. In fetal life the rates of proliferation and apoptosis are high. We studied if the rate of apoptosis decreases after birth, by measuring the soluble (s) forms of Fas‐Fas ligand and Tumor necrosis factor receptor 1 (TNFR1)‐TNF‐α which attenuate apoptosis.

Adhesion Molecules in Early Neonatal Life

This study investigated whether serum levels of the adhesion molecules VCAM-1, PECAM-1 and L-selectin, all of which have been implicated in normal immune function, change soon after birth. Moreover, the dependence of serum levels of the above-mentioned adhesion molecules on sex and mode of delivery was studied. In healthy neonates, serum levels of L-selectin, PECAM-1, and VCAM-1 do not change during early neonatal life. Thus, significant differences in their serum concentrations soon after birth might imply inflammatory processes or deranged endothelial homeostasis, serving as possible diagnostic markers.