Dagmar-Christiane Fischer

Interleukin-1beta and interleukin-8 concentrations in the Lower uterine segment during parturition at term

Objective To assess the roles of interleukin-1β, interleukin-8, and fibroblasts in the lower uterine segment during parturition. Methods Lower uterine segment biopsy specimens were obtained from 36 women undergoing cesarean delivery at various stages of cervical dilation (less than 2 cm, n = 8; 2 to less than 4 cm, n = 9; 4-6 cm, n = 10; more than 6 cm, n = 9). The concentrations of interleukin-1β and interleukin-8 in protein extracts prepared from the tissue samples were measured by enzyme immunoassays. The effect of incubation with interleukin-1β (30 U/mL) on interleukin-8 secretion by lower uterine segment fibroblasts in vitro also was determined. Results The median interleukin-1β concentration in the specimens increased from 1.3 pg/mg of total protein at less than 2 cm of dilation to 22.2 pg/mg of total protein at 4-6 cm of dilation (P < .05). No further increase was detectable after 6 cm of dilation. The interleukin-8 concentration increased from 17.2 pg/mg of total protein at less than 2 cm of dilation to 2080.7 pg/mg of total protein at 4-6 cm of dilation (P < .05), thus paralleling the increase in interleukin-1β concentration. Interleukin-1β induced a significant increase in interleukin-8 secretion by fibroblasts in vitro, from 0.8 ng/106 cells to 35.6 ng/106 cells. Conclusion The increase in interleukin-8 concentration in the lower uterine segment during parturition may be induced by interleukin-1β and fibroblasts may be one of the sources of this interleukin-8.

Collagenolysis in the lower uterine segment during parturition at term: correlations with stage of cervical dilatation and duration of labor.

OBJECTIVE The objective of this study was to quantify the extent of neutrophil infiltration and the concentrations of enzymes involved in collagenolysis in the lower uterine segment in relation to the degree of cervical dilatation and the duration of labor. STUDY DESIGN Biopsy specimens of the lower uterine segment were obtained from 62 women undergoing cesarean section at term. The number of extravascular neutrophils was assessed with enzyme histochemical evaluation, and the concentrations of matrix metalloproteinase-8, matrix metalloproteinase-9, and tissue inhibitor of metalloproteinases-1 by were assessed by enzyme-linked immunosorbent assay. RESULTS The neutrophil count and the concentrations of matrix metalloproteinase-8, matrix metalloproteinase-9, and tissue inhibitor of metalloproteinases-1 increased with increasing cervical dilatation. At >6 cm the neutrophil count and the concentrations of matrix metalloproteinase-8, matrix metalloproteinase-9, and tissue inhibitor of metalloproteinases-1 were significantly higher than at <2 cm. An association with the duration of labor was found for the neutrophil count and the concentrations of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinases-1. Multiple linear regression analysis showed that the degree of cervical dilatation is more closely related to the 4 laboratory parameters investigated than to the duration of labor. CONCLUSION The findings support the hypothesis that local changes (ie, collagenolysis) in the lower uterine segment unrelated to uterine activity play a crucial role in cervical dilatation at term.

Tissue concentrations of cytokines in the lower uterine segment during preterm parturition

Abstract Aims: To determine the concentrations of tumor necrosis factor α, interleukin-1β, interleukin-6, and interleukinin the lower uterine segment during preterm parturition. Methods: In 71 patients who delivered prematurely nonelective cesarean tissue specimens were obtained from the lower uterine segment. The patients were grouped in relation to the stage of cervical dilatation (< 2 cm, 2–< 4 cm, ≥ 4 cm), duration of labor (≤ 6h, > 6–12 h; > 12 h), and parity (1 versus > 1). Cytokine concentrations in protein extracts of the tissue samples were measured using enzyme-linked immunosorbent assays. Results: Median concentration of tumor necrosis factor α did not change, but that of interleukin-1β, interleukin-6, and interleukin-8 were significantly higher at 2–< 4 cm than at < 2 cm cervical dilatation (6.6, 67.7, and 125.8 versus 1.1, 17.6, and 22.2 pg/mg protein, respectively). The concentrations of interleukin-6 and interleukin-8 showed a further increase at ≥ 4 cm (297.2 and 468.6 pg/mg, respectively), but for interleukin 1β a decrease was observed (0.6 pg/mg). Cytokine concentrations were not related to duration of labor or parity. Conclusions: Local inflammationassociated changes that are mainly related to the stage of cervical dilatation and to only a minor degree to uterine activity may play a crucial role in preterm parturition.

Estorgen Receptor α and Progesterone Receptor A and B Concentration and Localization the Lower Uterine Segment in Term Parturition

Objective: To determine the localization and concentrations of estrogen receptor α and progesterone receptors A andB in the lower uterine segment during term parturition. Methods: Biopsies were taken from 70 patients during nonelective cesarean delivery. The patients were at different stages of cervical dilatation (<2 cm, 2-3.9 cm, 4-6 cm, >6 cm) and different duration of labor (≤6 hours, >6-12 hours, >12 hours). The receptor concentrations were determined with solid phase immunoassays, and their localization was investigated immunohistochemically. Results: Estrogen receptor α concentration decreased significantly from 2.12 fmol/mg protein at less than 2 an dilatation to 1.08 fmol/mg (4-6 cm) but tended to increase at greater than 6 cm. Progesterone receptor A and B concentration was 84.7 fmol/mg at less than 2 cm dilatation, decreased significantly to 36.6 fmol/mg (2-3.9 cm), and increased again with further dilation. Concentrations of both receptors did not depend on duration of labor. By immunohistochemistry only progesterone receptor A and B was found to be expressed by endothelial and smooth muscle cells of the vessels, stromal fibroblasts, smooth muscle cells in the myometrium, and glandular epithelial cells. Regardless of the extent of cervical dilatation, expression of progesterone receptors A and B was marked. Conclusion: A decrease in estrogen receptor α and progesterone receptor A and B concentration in the early phase of first stage labor may play a role in cervical dilation at term.

Regulation of interleukin-8 synthesis in human lower uterine segment fibroblasts by cytokines and growth factors

Objective To investigate the influence of lipopolysaccharide, cytokines, growth factors, and progesterone on the synthesis of interleukin-8 by human lower uterine segment fibroblasts. Methods Fibroblasts derived from a lower uterine segment biopsy specimen obtained from a woman undergoing elective cesarean delivery at term were exposed to lipopolysaccharide, interleukin-1β, transforming growth factor-β1, platelet-derived growth factor-AB, and combinations of these substances. All experiments were performed in the absence and presence of progesterone. The concentration of interleukin-8 in the culture medium was determined by enzyme immunoassay after 24 hours. Results Compared with controls (0.71 ± 0.04 ng interleukin-8/106 cells), fibroblasts exposed to lipopolysaccharide, transforming growth factor-β1, or platelet-derived growth factor-AB exhibited no increase, or at most, only a minor but significant increase, in interleukin-8 secretion. Incubation with interleukin-1β led to a moderate increase, whereas the combinations interleukin-1β/transforming growth factor-β1 (105.0 ± 7.5 ng interleukin-8/106 cells) and interleukin-1β/platelet-derived growth factor-AB (387.3 ± 25.6 ng interleukin-8/106 cells) increased interleukin-8 secretion dramatically. No further increase was observed with the combination interleukin-1β/platelet-derived growth factor-AB/transforming growth factor-β1. When progesterone was added, interleukin-8 secretion decreased significantly by 16–34%, depending on the stimulator, or did not change. Conclusion The findings indicate that interleukin-8 secretion by human lower uterine segment fibroblasts in vitro is upregulated by interleukin-1β, transforming growth factor-β1, and platelet-derived growth factor-AB in a synergistic fashion. Because interleukin-8 mediates the invasion of neutrophils into the cervical stroma, this may be an important mechanism controlling cervical dilatation during parturition.

Chorioamnionitis: elevated interleukin-6 and interleukin-8 concentrations in the lower uterine segment.

Abstract Aims: To determine interleukin (IL)-6 and IL-8 concentrations in the lower uterine segment in patients with chorioamnionitis compared to those without. Methods: Biopsy specimens from the lower uterine segment of 33 patients with chorioamnionitis were matched to specimens of 33 patients without. The biopsies had been taken during cesarean section. The concentrations of IL-6 and IL-8 in protein extracts of these specimens were determined by enzyme linked immunosorbent assays. Results: Compared to the controls patients with chorioamnionitis showed significantly lower gestational age and higher parity, and were more likely to receive fenoterol or betamethasone. In the chorioamnionitis group the median IL-6 concentrations were higher than in the controls (61.5 and 19.4 pg/mg protein, respectively [p < 0.01]). The same applies to the median IL-8 concentrations (162.3 and 13.4 pg/mg protein, respectively [p < 0.001]). Conclusions: To our knowledge this is the first study which could clearly demonstrate significantly increased IL-6 and IL-8 levels in the lower uterine segment of patients with chorioamnionitis. Increased concentrations of pro-inflammatory cytokines may play a pivotal role in cervical softening and dilatation during chorioamniotic infection.

A large keratan sulfate proteoglycan present in human cervical mucous appears to be involved in the reorganization of the cervical extracellular matrix at term.

Objective: To elucidate the function of keratan sulfate proteoglycan (KS-PG) in the human uterine cervix, we analyzed its distribution with respect to physiologic conditions. Methods: Immunohistochemistry was used to localize KS bearing proteoglycans (mAb 5D4) and decorin (mAb 6B6) in the lower uterine segment. Proteins present in cervical mucous were labeled with biotin, glycosaminoglycan chains were digested enzymatically, and the samples were analyzed by Western blot. Results: Decorin was detected throughout the extracellular matrix, in tissues from menstruating nonpregnant women, in early pregnancy, from women who had cesarean at term, at postpartum hysterectomy, and from postmenopausal women. In menstruating nonpregnant women, in early pregnancy (first trimester), and in postmenopausal women, KS-PG was detectable only in epithelial, mucous-producing cells. Interestingly, in samples obtained either at the time of cesarean at term (lower uterine segment) or after postpartal hysterectomy, KS-PG was detectable throughout the extracellular matrix, indicating that the expression of KS-PG is associated with reorganization of the tissue. Biochemical analysis of the KS present in mucous revealed a core protein in the range of 220 kDa, suggesting an identity with the large KS-PG described previously. Conclusion: At parturition, a large KS-PG, which is virtually exclusively present in the cervical mucous of either early or nonpregnant women, was detected in the extracellular matrix. This finding indicates that cervical ripening is accompanied not only by quantitative but also by qualitative changes in the composition of the extracellular matrix.

Tissue concentrations of endothelial cell adhesion molecules in the lower uterine segment during term parturition.

Objective To determine the concentration of endothelial cell adhesion molecules in the lower uterine segment during parturition at term. Methods We analyzed protein extracts from the lower uterine segments of 38 women who had nonelective cesareans at term. We measured concentrations of intercellular adhesion molecule-1, endothelial leukocyte adhesion molecule-1, vascular cell adhesion molecule-1, and platelet endothelial cell adhesion molecule-1 by enzyme-linked immunosorbent assay. Subjects were grouped according to cervical dilatation (less than 2 cm, n = 10; 2 to less than 4 cm, n = 9; 4–6 cm, n = 9; more than 6 cm, n = 10) and duration of labor (up to 6 hours, n = 14; 6–12 hours, n = 10; 12–24 hours, n = 9; longer than 24 hours, n = 5) at the time of cesarean. Results The median concentration of intercellular adhesion molecule-1 increased significantly with increasing dilatation (from 2.24 ng/mg total protein at less than 2 cm to 6.73 ng/mg at 4–6 cm) and increasing duration of labor (from 2.53 ng/mg up to 6 hours to 5.90 ng/mg at 12–24 hours). However, this study did not have adequate statistical power to identify differences in concentrations of the other endothelial adhesion molecules. Conclusion The results indicate that parturition at term is associated with expression of intercellular adhesion molecule-1.

Development of an enzyme immunoassay specific for a core protein epitope of a novel small basement membrane associated heparan sulphate proteoglycan from human kidney.

Heparan sulphate proteoglycans are major components of the glomerular basement membrane and play a key role in their molecular organization and function. Moreover, their presence is essential for the maintenance of the selective permeability of the glomerular basement membrane. Recently, we have isolated and characterized a novel, small basement membrane associated heparan sulphate proteoglycan from human aorta and kidney. Using specific monoclonal antibodies we have shown that the novel heparan sulphate proteoglycan is predominantly located in the glomerular basement membrane, to a lesser extent in the basement membrane of tubuli, and also in the mesangium. Turnover or, in the course of kidney diseases, degradation of heparan sulphate proteoglycan from glomerular basement membranes may lead to urinary excretion of heparan sulphate proteoglycan. Therefore, changes in the structure and function of glomerular basement membranes may be directly detected by measuring the excretion of a component of this basement menbrane, e. g. heparan sulphate proteoglycan into urine. Here we describe the establishment of an enzyme immunoassay for the sensitive detection of the novel, small heparan sulphate proteoglycan in urine. In this assay the specific monoclonal antibody 1F10/B8, which recognizes a core protein epitope, was used to detect the polyanionic heparan sulphate proteoglycan bound to the surface of a cationic charge modified microtitre plate. This assay allows the sensitive and specific detection of the small heparan sulphate proteoglycan, which is released from the glomerular basement membrane into urine during normal turnover and also in the course of kidney diseases.

Der Einfluß der Lungenreifeinduktion mit Betamethason auf maternale Infektionsparameter bei vorzeitigen Wehen

Preterm labour and preterm delivery are often caused by intrauterine infections. To detect these infections, determination of the serum level of the C-reactive protein (CRP) as well as the total leukocyte count is usually performed. Glucocorticoids which are generally applied at the same time for induction of fetal lung maturity, are suspected to influence these parameters. Therefore we performed a prospective longitudinal study to evaluate the influence of betamethasone on maternal infection parameters. Methods: 20 women between the 26 th and 35 th week of gestation with premature labour under intravenous tocolysis with fenoterol without any sign of infection (total leukocyte count <15 G/I, CRP <20 mg/l), received betamethasone (12mg i.m. each 24 hours for 2 days). C-reactive protein, the total leukocyte count, differential blood count, haptoglobin levels as well as Tumour Necrosis Factor (TNF)α and Interleukin (IL)-1β were determined at 24-hour intervals before, during and after lung maturity induction. Statistical analysis was performed by means of Wilcoxons rank sum test. Results: The administration of betamethasone led to a marked fall in the level of C-reactive protein (on average to 43% of the initial value) and significant leukocytosis (on average to 45% above the initial value). The other investigated parameters did not show any clinically relevant changes. Conclusion: After use of betamethasone in the above mentioned manner for induction of fetal lung maturity, the levels of C-reactive protein and leukocyte count are falsified and bence cannot be regarded as reliable indicators of maternal infection under these circumstances.