The aim of this study was to evaluate factors that influence leptin levels in postmenopausal women. One hundred and forty-four postmenopausal women were evaluated cross-sectionally. In every woman a complete medical history was obtained, body mass index (BMI) was recorded and morning fasting blood was obtained for the determination of serum leptin, follicle stimulating hormone (FSH), estradiol, testosterone, Δ4androstendione, clehydroepiandrosterone sulphate (DHEAS) and insulin. In univariate analysis, age, BMI and insulin were positively correlated with serum leptin, while DHEAS showed a negative association with leptin concentrations (age r=0.21, p=0.005, BMI r=0.41, p=0.0001, insulin r=0.20, p=0.008, DHEAS r=-0.28, p=0.0001). In stepwise multivariate regression analysis serum leptin could be best predicted from BMI, serum insulin and serum DHEAS [leptin= (1.41 * BMI) - (0.01 * DHEAS) + (3.26 * insulin) -26.3; model r2=0.24, p=0.001]. In conclusion, BMI and serum insulin have a positive while serum DHEAS has a negative impact on serum leptin. Neither endogenous estradiol, nor endogenous testosterone are associated with leptin levels. Further studies are needed to elucidate the role of leptin in determining body weight and composition in postmenopausal women. © 2003, Editrice Kurtis.

The European Communities Confederation of Clinical Chemistry and Laboratory Medicine (EC4) opened a Register for European Chemists in 1997. The operation of the Register is undertaken by a Register Committee (EC4RC). During the last 5 years more than 1400 clinical chemists entered the register. In this article an update of the first Guide to the Register is given, based on the experience of 5 years of operation and the development of the discipline. The registration is valid for 5 year. In a second part the procedure and the conditions for re-registration are presented.

Background: After birth, apoptosis rates might slow down, compared to those in utero. Thus, factors, attenuating the apoptotic process, like the soluble forms of Fas/FasL system, may increase. Aim - study design: Soluble Fas (sFas) and soluble Fas ligand (sFasL) concentrations were measured in maternal serum (MS), umbilical cord (UC) and neonatal serum in the first (1N) and fifth (5N) days after birth in order to evaluate the alterations of these molecules during the early neonatal period. Subjects and methods: Soluble molecules were estimated in 35 healthy, appropriate for gestational age, full-term neonates, their mothers and in 25 healthy, nonpregnant women, age-matched to the mothers (controls), using enzyme immunoassays. Results: sFas concentrations in MS (p<0.01), UC (p<0.0001), 1N (p<0.0003) and 5N (p<0.02) were lower than those in controls. Neonatal sFas concentrations showed a significant increase from UC to 5N (p<0.001). In contrast, sFasL concentrations were significantly elevated in all neonatal samples (UC, 1N and 5N) compared to those in MS and controls (p<0.0001), showing also a significant elevation from UC to 5N (p<0.0001). Conclusion: Our results demonstrate increasing serum concentrations of the soluble molecules sFas and sFasL during the first days after birth, indicating possibly a gradual decrease of apoptosis in early neonatal life. © 2003 Elsevier Ireland Ltd. All rights reserved.

Objective: To determine postnatal changes in neonatal serum concentrations of interferon-γ (IFN-γ), interleukin-4 (IL-4) and its soluble receptor (sIL-4R). Methods: Forty-five healthy term neonates, 25 of the neonates' mothers and 27 healthy adults (controls) participated in the study. Cytokine concentrations were measured in blood samples from the umbilical cord, from the neonates on the 1st and 5th day after birth, from mothers and from controls. Results: IFN-γ concentrations were significantly lower in the umbilical cord, compared to concentrations in the controls (p < 0.04), and increased significantly from the umbilical cord to levels in neonates on day 5 (p < 0.03). In mothers and the umbilical cord, IFN-γ concentrations were dependent on the mode of delivery, being higher after vaginal delivery than after elective Cesarean section (p < 0.005; p < 0.006, respectively). IL-4 concentrations in the umbilical cord for 1-day and 5-day neonates were significantly elevated compared to those in mothers (p < 0.001; p < 0.0007; p < 0.0001, respectively) and controls (p < 0.05; p < 0.01; p < 0.006, respectively). sIL-4R concentrations in all neonatal samples were significantly elevated compared to those in controls (p < 0.0001), the highest being found in 1-day-old neonates. A strong negative correlation was found between IL-4 and sIL-4R concentrations in 1- and 5-day-old neonates (r = -0.48, p < 0.002; r = -0.45, p < 0.0065, respectively). Moreover, IFN-γ/IL-4 ratio increased significantly from the umbilical cord to 5 days of life (p < 0.03). Conclusions: Our findings indicate an earlier development of IL-4 than IFN-γ, which could be viewed as a developmental characteristic in the ontogeny of the immune system.

BACKGROUND: In contrast to cellular receptors, soluble receptors do not enhance the cellular activation because they do not have transmembranic and cytoplasmic parts, acting thereby as endogenous regulatory mechanisms against systemic functions of cytokines. Aim: To measure serum concentrations of the soluble interleukin-2 receptor (sIL2R), soluble interleukin-4 receptor (sIL4R), soluble interleukin-6 receptor (sIL6R), and soluble tumor necrosis factor-α receptor I and soluble tumor necrosis factor-α receptor II, during the perinatal and early neonatal period, in order to evaluate their role in activation of immune response in labor and the first days postpartum. Methods: Soluble receptor serum concentrations were determined by enzyme-linked immunosorbent assay, in 45 healthy, full-termed neonates during the first and fifth days after birth, in 25 of their mothers (MS), in 25 samples of umbilical cords (UC) and in 25 healthy adult donors age-matched with the mothers (controls). Results: Soluble receptor serum concentrations showed considerable changes during labor and early neonatal life, being significantly higher both in MS (except sIL6R) and in neonatal sample UC, first and fifth days after birth, compared with controls (p < 0.0001). Neonatal serum sIL2R and sIL6R increased significantly from birth to the fifth day, while the remaining receptors showed a rapid increase in the first day (p < 0.0001), declining significantly thereafter (p < 0.0001). Conclusion: Our Findings suggest that the elevated concentrations of all studied soluble cytokine receptors reflect the activation of immune response, and represent also regulatory protective mechanisms for mother and fetus-neonate against the systemic function of cytokines during labor and early neonatal life.