The European Communities Confederation of Clinical Chemistry and Laboratory Medicine (EC4) opened a Register for European Specialists in Clinical Chemistry and Laboratory Medicine in 1997. The operation of the Register is undertaken by a Register Committee (EC4RC). During the last 6 years more than 1500 specialists in clinical chemistry and laboratory medicine have joined the Register. In this article a Code of Conduct for Registrants which was approved at the EC4 Register Committee meeting in Amsterdam, 8 November 2003 is presented. © 2004 by Walter de Gruyter.

Objective: To evaluate the effect of estrogen replacement therapy (ERT), continuous combined hormone replacement therapy (HRT) and tibolone on serum leptin levels in healthy postmenopausal women. Methods: Eighty-four healthy postmenopausal women aged 43-63 years were studied prospectively. Hysterectomized women (n=16) received conjugated equine estrogens (CEE) 0.625 mg. Women with an intact uterus were randomly allocated either to CEE+medroxyprogesterone acetate (CEE/MPA) 5 mg or tibolone 2.5 mg. Serum leptin levels were assessed at baseline and after 6 months of treatment. Results: The three groups did not differ with respect to age, body mass index (BMI) or baseline serum leptin levels. Overweight women (BMI>25 kg/m2) had higher baseline leptin levels (27.0±11.4 ng/ml) compared to their lean counterparts (BMI≤25 kg/m2; leptin: 16.5±8.1 ng/ml, P=0.0001). Neither CEE nor CEE/MPA had any effect on serum leptin levels at the end of 6 months either in overweight or in lean women (overweight: CEE baseline 34.4±13.3 ng/ml, 6 months 36.9±15.8, P=0.89, CEE/MPA baseline 22.4±9.8 ng/ml, 6 months 26.8±8.7 ng/ml, P=0.1; lean: CEE baseline 12.6±4.4 ng/ml, 6 months 13.2±5.8 ng/ml, P=0.36, CEE/MPA baseline 17.2±10.6 ng/ml, 6 months 18.8±8.8 ng/ml, P=0.31). Similarly serum leptin remained unchanged at the end of the study in both lean and overweight women on tibolone (overweight: baseline 22.9±8.1 ng/ml, 6 months 18.5±12 ng/ml, P=0.37; lean: baseline 13.2±5.6 ng/ml, 6 months 17.3±8.4 ng/ml). Conclusion: BMI is a strong determinant of serum leptin levels in healthy postmenopausal women. Neither ERT/HRT nor tibolone exert any effect on serum leptin after 6 months in lean or overweight postmenopausal women. Further studies are required to verify the exact role of estrogen and tibolone on leptin production and function in postmenopausal women. © 2003 Elsevier Ireland Ltd. All rights reserved.

Objective: To assess the effect of continuous combined hormone replacement therapy (HRT) or tibolone on serum total homocysteine (tHcy) levels in postmenopausal women. Study design: Ninety-five postmenopausal women aged 41-68 years were included in the study. Seventy-three women with climacteric complaints, osteopenia or osteoporosis received either conjugated equine estrogens 0.625mg combined with medroxyprogesterone acetate 5mg (CEE/MPA, n=31) or tibolone 2.5mg (n=42). Twenty-two healthy women, matched for chronological and menopausal age, served as controls. Serum tHcy levels were assessed at baseline, 6, 12 and 18 months. Results: No difference was recorded between groups regarding demographic characteristics or mean baseline serum tHcy. Serum tHcy levels decreased significantly in the CEE/MPA compared to baseline (change at 18 months: -3.9%, P<0.05). The magnitude of the decrease was higher in the subgroup of women with baseline tHcy levels above the median (change at 18 months: -15.0%, P<0.01). No change in tHcy levels was detected in the tibolone group throughout the study period, either in the whole group (change at 18 months: 1.9%, NS) or in the subgroup with baseline tHcy levels above the median (change at 18 months: -3.23%, NS). Conclusion: Continuous CEE/MPA reduces tHcy especially in women with high pretreatment tHcy levels. Tibolone has no effect on serum tHcy levels at least during the first 18 months of therapy. Larger studies with longer follow-up are required to confirm these results. © 2003 Elsevier Ireland Ltd. All rights reserved.

OBJECTIVE: To evaluate age-related differentiation of immune response in newborns by measuring serum concentrations of interleukin-2 (IL-2), interleukin-4 (IL-4) and interferon-γ (IFN-γ) during the perinatal period. Subjects and methods: Fifty-seven healthy term neonates, their mothers and 25 healthy adults (controls) age-matched to the mothers were included in the study. Cytokine concentrations were measured in the umbilical cord (UC), and in first-day (1N) and fifth-day (5N) neonatal samples, compared with those in maternal serum (MS) and control serum samples. Results: Serum IL-2 concentrations in the UC were markedly elevated compared with those in MS and controls (p < 0.0001), decreasing significantly thereafter up to 5N (p < 0,001). IL-4 serum concentrations did not differ significantly between the UC, 1N and 5N samples; they were, however, markedly elevated compared with those in MS (p < 0.001, p < 0.0007 and p < 0.0001, respectively) and controls (p < 0.05, p < 0.01 and p < 0.006, respectively). IFN-γ serum concentrations were significantly lower in the UC compared with those in controls (p < 0.04), increasing significantly up to 5N (p < 0.03). Both IFN-γ/IL-2 and IFN-γ/IL-4 ratios increased significantly in 5N, compared with those in the UC (p < 0.001 and p < 0.03). Conclusion: Our findings indicate a differential cytokine balance at birth with enhanced expression of IL-2 and IL-4 against IFN-γ. However, a regularization of immune response seems to proceed quickly during the early neonatal life.

Objective: Atrial natriuretic peptide (ANP) plasma levels are increased in patients with valvular heart disease. The present study investigates possible changes after mitral or aortic valve replacement (MVR, AVR). Methods: In this prospective study, ANP plasma levels were measured in 11 patients undergoing MVR for mitral stenosis, in 11 patients undergoing AVR for aortic valve stenosis, and in 6 patients without heart disease undergoing thoracotomy for lung resection (control group). Blood samples were collected preoperatively (1 day before), during, and 8 days after the operation by serial blood sampling and were determined by radioimmunoassay method. ANP values were correlated with the duration of cardiopulmonary bypass (CPB), the aortic cross-clamping time, and the left atrial filling pressures. Results: ANP plasma levels were increased in all patients with valvular heart disease preoperatively and did not change during anesthesia or CPB; nor were they correlated with CPB duration or atrial filling pressures. The left atriotomy did not alter ANP plasma levels. The intracardiac surgical manipulations as well as CPB did not influence the ANP secretion intraoperatively and during the first postoperative week. Patients who underwent lung resection showed no change of ANP plasma levels perioperatively. Conclusion: ANP levels are not altered during and 1 week after valve replacement and, therefore, do not reflect hemodynamic changes perioperatively. © 2004 Elsevier Inc. All rights reserved.