Squamous cell carcinoma antigen as a novel candidate marker for amniotic fluid embolism.

AIM: We aimed to evaluate the clinical usefulness of serum squamous cell carcinoma (SCC) antigen for the diagnosis of amniotic fluid embolism (AFE). METHODS: Sera and information of 20 patients with AFE (autopsy-proven AFE, four cases; clinical AFE, 16 cases) were obtained from the Japan Amniotic Fluid Embolism Registration Center at Hamamatsu University School of Medicine. As controls, we included 74 gestational-age-matched healthy women who gave birth to healthy newborns during the period from December 2012 to January 2014. Receiver-operator curves (ROC) were used to evaluate the diagnostic performance of SCC levels for prediction of AFE. RESULTS: Serum SCC antigen levels in women with autopsy-proven AFE (112.0 ± 169.4 ng/mL, P = 0.001) and clinical AFE (9.5 ± 10.3 ng/mL, P = 0.004) were significantly higher than those in healthy controls with normal delivery (4.4 ± 2.2 ng/mL). On ROC analysis, the optimal cut-off value for SCC antigen levels was 7.15 ng/mL, for which the sensitivity and specificity for AFE prediction was 60.0% and 89.2%, respectively (area under the ROC, 0.785; 95% confidence interval, 0.663-0.908; P < 0.001). CONCLUSION: Serum SCC antigen may be a promising predictor of the entry of amniotic fluid into the maternal circulation, potentially serving as a candidate marker for noninvasive diagnosis of AFE.

Predictor of mortality in patients with amniotic fluid embolism.

AIM: The purpose of this study was to evaluate the possibility of establishing predictors of mortality in women with amniotic fluid embolism. METHODS: Our previous report identified eight factors associated with amniotic fluid embolism (AFE) fatality: dyspnea, cardiac arrest, loss of consciousness, serum sialyl Tn greater than 47 U/mL, serum interleukin-8 greater than 100 pg/mL, vaginal delivery, multiparity and term delivery. The ratio of the number of positive fatal factors to the number of possible fatal factors in the same case was calculated as the abundance ratio, which was used because information regarding all eight factors was not retrievable for all the patients at the time of registration. The patient group was divided into four quartiles based on this abundance ratio, and the mortality rate in each quartile was compared with the overall mortality rate among the 130 patients with AFE enrolled between 1992 and 2006. The validity of this approach was confirmed in another dataset from a cohort of 38 patients with AFE in 2007. RESULTS: A statistically significant positive correlation was observed between the abundance ratio and the mortality in each quartile (P<0.01) for the patients with AFE enrolled between 1992 and 2006. This result was also found in the AFE patients enrolled in 2007 (P<0.05). Thus, an increased in the abundance ratio of the eight fatal factors resulted in an increased case fatality rate. CONCLUSION: These data suggested that the abundance ratio of fatal factors may be a useful predictor of mortality and therefore may be expected to improve prognostic accuracy in the future.

Chemokine and free fatty acid levels in insulin-resistant state of successful pregnancy: a preliminary observation.

Increased insulin resistance and inflammatory action are observed in pregnancy-induced hypertension (PIH), but similar insulin resistance is observed also in successful pregnancy. To estimate insulin resistance and inflammatory activity in normal pregnancy and PIH, serum concentrations of free fatty acids (FFA; corrected with albumin to estimate unbound FFA), monocyte chemoattractant protein (MCP)-1, and high-molecular weight (HMW) adiponectin were measured in severe PIH patients with a BMI less than 25 kg/m(2) and were measured 3 times during the course of pregnancy in women with normal pregnancies. FFA/albumin, MCP-1, and HMW adiponectin concentrations were significantly higher in PIH patients than in women with normal pregnancies. The 3 measurements of FFA/albumin showed a significant increase through the course of uncomplicated pregnancies. In contrast, MCP-1 and HMW adiponectin were significantly decreased during the course of pregnancy. These results suggest that the reduced MCP-1 concentration in normal pregnancy may be a pathway to inhibit the induction of pathological features from physiological insulin resistance and homeostatic inflammation.

Combination of B-Lynch brace suture and uterine artery embolization for atonic bleeding after cesarean section in a patient with placenta previa accreta.

We report the case of a patient with placenta previa accreta. A 29-year-old multipara, who had previously undergone a cesarean section, was admitted to our hospital for vaginal bleeding. An emergency cesarean section was carried out at the 33rd week of gestation. Uterine bleeding was uncontrollable, and hence, hysterectomy was planned. However, before hysterectomy, B-Lynch brace suture was carried out to control the massive bleeding; moreover, the suturing technique enabled uterine artery embolization to be carried out as an interventional radiological technique. A good postoperative course was observed, and thus, a secondary hysterectomy was not required. A combination of the B-Lynch brace suture technique and uterine artery embolization may be an alternative treatment for emergency bleeding during cesarean section in patients with placenta previa accreta.

Inflammatory pattern recognition receptors and their ligands: factors contributing to the pathogenesis of preeclampsia.

PROBLEM: Preeclampsia, a pregnancy-specific hypertensive syndrome, is one of the leading causes of premature births as well as fetal and maternal death. Preeclampsia lacks effective therapies because of the poor understanding of disease pathogenesis. The aim of this paper is to review molecular signaling pathways that could be responsible for the pathogenesis of preeclampsia. METHOD OF STUDY: This article reviews the English-language literature for pathogenesis and pathophysiological mechanisms of preeclampsia based on genome-wide gene expression profiling and proteomic studies. RESULTS: We show that the expression of the genes and proteins involved in response to stress, host-pathogen interactions, immune system, inflammation, lipid metabolism, carbohydrate metabolism, growth and tissue remodeling was increased in preeclampsia. Several significant common pathways observed in preeclampsia overlap the datasets identified in TLR (Toll-like receptor)- and RAGE (receptor for advanced glycation end products)-dependent signaling pathways. Placental oxidative stress and subsequent chronic inflammation are considered to be major contributors to the development of preeclampsia. CONCLUSION: This review summarizes recent advances in TLR- and RAGE-mediated signaling and the target molecules, and provides new insights into the pathogenesis of preeclampsia.

Redox-active iron-induced oxidative stress in the pathogenesis of clear cell carcinoma of the ovary.

OBJECTIVE: Epithelial ovarian cancer (EOC) is the most lethal pelvic gynecologic cancer. Clear cell carcinoma (CCC) and endometrioid adenocarcinoma (EAC) of the ovary have been associated with endometriosis, thus indicating that endometriosis has been believed to increase the risk of developing EOC. The aim of our review was to identify and synthesize the most current information on CCC with regard to molecular and pathophysiological distinctions. METHOD: This article reviews the English-language literature for molecular, pathogenetic, and pathophysiological studies on endometriosis and endometriosis-associated ovarian cancer (EAOC). In this review, we focus on the functions and roles of redox-active iron in CCC carcinogenesis. RESULTS: The iron-induced reactive oxygen species signals can contribute to carcinogenesis via 3 major processes: step 1, by increasing oxidative stress, which promotes DNA mutagenesis, histone modification, chromatin remodeling, and gene products activation/inactivation thus contributing to EAOC initiation; step 2, by activating detoxification and antiapoptotic pathways via the transcription factor hepatocyte nuclear factor 1ß overexpression, thereby contributing to CCC promotion; and step 3, by creating an environment that supports sustained growth, angiogenesis, migration, and invasion of cancer cells via estrogen-dependent (EAC) or estrogen-independent (CCC) mechanisms, thus supporting tumor progression and metastasis. CONCLUSIONS: These aspects of reactive oxygen species biology will be discussed in the context of its relationship to EAOC carcinogenesis.

New insights into the pathophysiology of endometriosis: from chronic inflammation to danger signal.

BACKGROUND: Various theories try to explain the development and progression of endometriosis, however, no single theory can explain all aspects of this disorder. Gene expression profiling studies might reveal factors that explain variability in disease development and progression, which can serve as specific biomarkers for endometriosis and novel drug development. We have recently showed that the upregulated genes were predominantly clustered in stress and detoxification, providing a mechanistic explanation for the oxidative stress and chronic inflammatory response in endometriosis. OBJECTIVE: This review aims: (1) to analyse the published data, with the aim of identifying pathways consistently regulated by the endometriosis genotype and (2) to summarise the findings of specific genes, which are involved in the process of oxidative stress and inflammation. METHODS: We identified gene array and proteomics studies whose data were accessible in PubMed. RESULTS: A major finding is the increased expressions of several markers including heat shock protein, S100, fibronectin, and neutrophil elastase, which might be involved in the process of Toll-like receptor (TLR)-dependent sterile inflammation. The study reviews a convergence in the main pathogenic process, where the TLR-mediated inflammation occurs possibly through the endogenous ligands. CONCLUSIONS: In conclusion, a circulus vitiosus of both the oxidative stress pathway and the TLR pathways is generated when the process becomes chronic (danger signal spiral).

Anticytokine therapy in preterm labor: current knowledge and future perspectives.

AIMS: Up to 10% of pregnant women have preterm birth that might be refractory to current therapy. Infections and asphyxia related to preterm birth are the causes of death in the majority of neonates and therefore represent an urgent clinical need. METHODS: The present article reviews the English language literature for preclinical and clinical trials and promising molecular targets on preterm labor. RESULTS: Preterm birth is a complex heterogeneous condition. There is no current treatment for the fetal membranes once they have ruptured; therefore, essentially any treatment has to be preventative to quiesce preterm labor and prevent any spread of infection to the fetus. Modulating the pro-inflammatory process-mediated cytokine network may present a new paradigm for preterm labor treatment. There are many reports on the role of ß-adrenergic agonists (betamimetics), magnesium sulfate, progesterone, oxytocin antagonist, calcium channel blocker or the Kunitz inhibitor bikunin in the treatment of preterm labor. In the present review, we have focused on the preclinical and clinical anticytokine therapy for preterm labor. The preclinical and clinical trials with bikunin reducing preterm labor exacerbations have raised the importance of usefulness and safety considerations related to this novel therapy. CONCLUSION: Anticytokine therapy is ready for the clinic.

Anti-inflammatory actions of serine protease inhibitors containing the Kunitz domain.

INTRODUCTION: Protease inhibitors, including the Kunitz, Kazal, serpin and mucus families, play important roles in inhibiting protease activities during homeostasis, inflammation, tissue injury, and cancer progression. Interestingly, in addition to their anti-protease activity, protease inhibitors also often possess other intrinsic properties that contribute to termination of the inflammatory process, including modulation of cytokine expression, signal transduction and tissue remodeling. In this review we have tried to summarize recent findings on the Kunitz family of serine proteinase inhibitors and their implications in health and disease. MATERIALS AND METHODS: A systematic search was performed in the electronic databases PubMed and ScienceDirect up to October 2009. We tried to limit the review to anti-inflammatory actions and actions not related to protease inhibition. RESULTS AND CONCLUSION: Recent studies have demonstrated that the Kunitz inhibitors are not only protease inhibitors, but can also prevent inflammation and tissue injury and subsequently promote tissue remodeling.

Evidence for activation of Toll-like receptor and receptor for advanced glycation end products in preterm birth.

OBJECTIVE: Individuals with inflammation have a myriad of pregnancy aberrations including increasing their preterm birth risk. Toll-like receptors (TLRs) and receptor for advanced glycation end products (RAGE) and their ligands were all found to play a key role in inflammation. In the present study, we reviewed TLR and RAGE expression, their ligands, and signaling in preterm birth. RESEARCH DESIGN AND METHODS: A systematic search was performed in the electronic databases PubMed and ScienceDirect up to July 2010, combining the keywords "preterm birth," "TLR", "RAGE", "danger signal", "alarmin", "genomewide," "microarray," and "proteomics" with specific expression profiles of genes and proteins. RESULTS: This paper provides data on TLR and RAGE levels and critical downstream signaling events including NF-kappaB-dependent proinflammatory cytokine expression in preterm birth. About half of the genes and proteins specifically present in preterm birth have the properties of endogenous ligands "alarmin" for receptor activation. The interactions between the TLR-mediated acute inflammation and RAGE-mediated chronic inflammation have clear implications for preterm birth via the TLR and RAGE system, which may be acting collectively. CONCLUSIONS: TLR and RAGE expression and their ligands, signaling, and functional activation are increased in preterm birth and may contribute to the proinflammatory state.

Fatal factors of clinical manifestations and laboratory testing in patients with amniotic fluid embolism.

AIMS: To identify factors leading to fatality of patients with amniotic fluid embolism (AFE). METHODS: Patients who had fatal or nonfatal AFE were registered at the Hamamatsu University School of Medicine in the Department of Obstetrics and Gynecology from 1992 to 2006. Data collected included information about demographics and clinical characteristics. The fatal factors among these data were identified using chi(2) analysis and the Mann-Whitney test. RESULTS: One hundred and thirty-five patients met the criteria, which included fatal (n = 65) and nonfatal AFE (n = 70). Maternal full-term gestational weeks, multiparous and noncesarean sections were the risk factors for death found in this study (p < 0.01). Sialyl Tn levels (mean +/- SD) in the serum of patients with fatal AFE (69.7+/- 126.4 U/ml) were higher compared to those with nonfatal AFE (48.3+/- 161.8 U/ml; p = 0.003). Each of three items (cardiac arrest, dyspnea or loss of consciousness) was more common in fatal AFE (p < 0.01). Maternal pregnancy and labor complications were not associated with the distinction between fatal and nonfatal AFE. CONCLUSION: Factors associated with patients with fatal AFE were identified. These included multiparity, noncesarean section at full-term and the three symptoms mentioned above. Sialyl Tn levels could be a possible prognostic fatality factor.

A case of intravenous leiomyomatosis with high levels of hyaluronan.

Intravenous leiomyomatosis (IVL) is a rare benign tumor. The clinical behavior can be life-threatening due to extension through the pelvic veins. A 70-year-old woman was referred to our hospital with IVL originating from a uterine leiomyoma and extending to the inferior vena cava. The patient was diagnosed on the basis of the results of various studies, and the tumor was resected completely through a single-stage approach. The intravascular tumor was 20 cm long, multinodular and rubbery. Microscopic findings showed benign smooth muscle that was partly hyalinized and fibrous. Immunohistochemical studies revealed that hyaluronan was expressed more prominently in IVL than in uterine leiomyomas. IVL has viscoelastic properties and contains a large amount of hyaluronan, which may promote invasion during pathogenesis.

The usefulness of photodynamic eye for sentinel lymph node identification in patients with cervical cancer.

AIMS AND BACKGROUND: We studied the potential use of sentinel lymph node identification using a near-infrared fluorescence imaging technique in the treatment of cervical cancer. METHODS AND STUDY DESIGN: Directly before the start of the operation, 0.2 ml of 5 mg/ml indocyanine green was prepared and injected into 4 sites in the cervix using a 26-gauge standard needle, at 3, 6, 9 and 12 o'clock positions. When the operation was advanced to the pelvis, near-infrared fluorescence imaging was performed using photodynamic eye (Hamamatsu Photonics Co., Japan). The sentinel lymph nodes and other dissected lymph nodes were histologically examined to find any metastases. RESULTS: Twelve patients were examined. Their ages ranged from 36 to 68 years (median, 58). Sentinel lymph nodes were identified in 10 patients (83%), and all were bilaterally identified. The median maximum tumor diameter of dissected cervical tumors was 35 mm (22-65); histology was squamous cell carcinoma in 8 patients and adenocarcinoma in 2 patients. Capillary lymphatic space involvement was found in 8 of the 10 patients. The site of the sentinel lymph node was the right external iliac node in 8 patients, the right obturator node in 8, the left external iliac node in 9, and the left obturator node in 8. Lymph node metastasis was found in 2 of the 12 patients, and all were sentinel lymph nodes. No metastasis from lymph nodes other than sentinel lymph nodes was observed. CONCLUSIONS: Photodynamic eye achieved a detection rate similar to that obtained with the blue dye and radioisotope method. It is also easier to use than the other two methods.

Molecular pathogenesis of endometriosis-associated clear cell carcinoma of the ovary (review).

Epithelial ovarian cancer (EOC) is the leading cause of death in women with gynecological malignancies. Among EOC, clear cell carcinoma (CCC) and endometrioid adenocarcinoma (EAC) differ from the other histological types with respect to their clinical characteristics and carcinogenesis. Both tumor types are often associated with endometriosis. EAC is recently reported to be characterized by K-RAS activation and PTEN dysfunction. However, the molecular changes in CCC remain largely unknown. The aim of this review is to summarize the current knowledge on the molecular mechanisms involved in CCC tumorigenesis. The present article reviews the English language literature for biological, pathogenetic and pathophysiological studies on endometriosis-associated CCC of the ovary. Several recent studies of loss of heterozygosity (LOH), allelic loss, comparative genomic hybridization, mutation, methylation status, microarray gene-expression profiling and proteomics are discussed in the context of CCC biology. Retrograde menstruation or ovarian hemorrhage carries highly pro-oxidant factors, such as heme and iron, into the peritoneal cavity or ovarian endometrioma. A histologically normal ectopic endometrium bears genetic damages caused by iron-dependent oxidative stress. DNA damage or LOH caused by oxidative stress is a critical factor in the carcinogenic process. LOH studies have implicated the involvement of specific chromosomal regions (5q, 6q, 9p, 10q, 11q, 17q and 22q). Furthermore, the PTEN and APC (early event), p53, polo-like kinases, Emi1 and K-RAS (late event) genes may be involved in CCC carcinogenesis. The molecular pathology of CCC is heterogeneous and involves various putative precursor lesions and multiple pathways of development, possibly via genetic alteration by oxidative stress.

The role of hepatocyte nuclear factor-1beta in the pathogenesis of clear cell carcinoma of the ovary.

PROBLEM: Clear cell carcinoma (CCC) of the ovary has a number of features distinguishing it from other epithelial ovarian carcinomas (EOC) because of its characteristic histology and biology, frequent concurrence with endometriotic lesion, and highly chemoresistant nature resulting in an extremely poor prognosis. The incidence of CCC has been steadily increasing in Japan. They comprise approximately 20% of all EOC. Understanding the mechanisms of CCC development and elucidating pathogenesis and pathophysiology are intrinsic to prevention and effective therapies for CCC. METHOD OF STUDY: This article reviews the English language literature for biology, pathogenesis, and pathophysiological studies on endometriosis-associated EOC. Several data are discussed in the context of endometriosis and CCC biology. RESULTS: Recent studies based on genome-wide expression analysis technology have noted specific expression of hepatocyte nuclear factor-1beta (HNF-1beta) in endometriosis and CCC, suggesting that early differentiation into the clear cell lineage takes place in the endometriosis. The HNF-1beta-dependent pathway of CCC will be discussed, which are providing new insights into regulation of apoptosis and glycogen synthesis and resistance of CCC to anticancer agents. CONCLUSIONS: This review summarizes recent advances in the HNF-1beta and its target genes; the potential challenges to the understanding of carcinogenesis, pathogenesis, and pathophysiology of CCC; and a possible novel model is proposed.

Expression profiles of genes involved in poor prognosis of epithelial ovarian carcinoma: a review.

BACKGROUND: Epithelial ovarian cancer (EOC) is the commonest cause of gynecological cancer-related mortality. Although the prognosis for patients with advanced cancer is poor, there is a wide range of outcomes for individual patients. OBJECTIVE: The aim of this study was to review molecular factors predictive of poor prognosis of women with EOC by reviewing microarray research identifying gene expression profiles. METHODS: A systematic search was performed in the electronic databases PubMed and ScienceDirect up to July 2008, combining the keywords "genome-wide," "microarray," "epithelial ovarian cancer" "prognosis," and "epithelial-mesenchymal transition" with specific expression profiles of genes. RESULTS: Many genes that participated in cell signaling, growth factors, transcription factors, proteinases, metabolism, cell adhesion, extracellular matrix component, cell proliferation, and anti-apoptosis were overexpressed in patients with poor prognosis. Several important prognosis-related genes overlap with those known to be regulated by epithelial-mesenchymal transition (EMT). This signaling pathway of EMT (E-cadherin, beta-catenin, receptor tyrosine kinases, NF-kappaB, TGF-beta, or Wnt signalings) will be discussed, as it provides new insights into a new treatment strategy. CONCLUSIONS: This review summarizes recent advances in prognosis-related molecular biology. Collectively, molecular changes possibly through EMT are considered to be a major contributor to the poor prognosis of EOC.

The role of iron in the pathogenesis of endometriosis.

BACKGROUND: Endometriosis may cause symptoms including chronic pelvic pain and infertility, and increases susceptibility to the development of ovarian cancer. Genomic studies have started to delineate the wide array of mediators involved in the development of endometriosis. Understanding the mechanisms of endometriosis development and elucidating its pathogenesis and pathophysiology are intrinsic to prevention and the search for effective therapies. METHOD OF STUDY: The present article reviews the English language literature for biological, pathogenetic and pathophysiological studies on endometriosis. Several recent genomic studies are discussed in the context of endometriosis biology. RESULTS: Severe hemolysis occurring during the development of endometriosis results in high levels of free heme and iron. These compounds oxidatively modify lipids and proteins, leading to cell and DNA damage, and subsequently fibrosis development. Recent studies based on genome-wide expression analysis technology have noted specific expression of heme/iron-dependent mediators in endometriosis. The heme/iron-dependent signaling pathway of endometriosis, which is providing new insights into the regulation of inflammation, detoxification and survival, is discussed. CONCLUSION: Several important endometriosis-specific genes overlap with those known to be regulated by iron. Other genes are involved in oxidative stress. Iron has a significant impact on endometriotic-cell gene expression. This review summarizes recent advances in the heme/iron-mediated signaling and its target genes, outlines the potential challenges to understanding of the pathogenesis and pathophysiology of endometriosis, and proposes a possible novel model.

Laparoscopic detorsion of the ovary in ovarian hyperstimulation syndrome during the sixth week of gestation: A case report and review.

INTRODUCTION: Ovarian torsion in ovarian hyperstimulation syndrome (OHSS) is a relatively rare but serious complication in pregnant women. A delay in treatment increases the risk for functional loss of the ovary and early termination of pregnancy. In this report, we present the case of a 40-year-old female with OHSS who experienced ovarian torsion that was successfully treated with laparoscopic detorsion. PRESENTATION OF CASE: A 40-year-old pregnant woman in the 6th week of gestation who had conceived following in vitro fertilization presented to us with severe and persistent lower abdominal pain. Ultrasound examination revealed a viable singleton intrauterine pregnancy and bilateral enlarged ovaries with scanty ascites. Approximately 14 h after symptom onset, exploratory laparoscopy was performed. The right ovary was found to be twisted once around over the pedicle, and laparoscopic detorsion was completed. Postoperative follow-up was uneventful, and she successfully delivered a healthy infant at 38 weeks of gestation. DISCUSSION: Although the reports on successful laparoscopic surgery for pregnant women with ovarian torsion are becoming more frequent, there are few reports on laparoscopic surgery for ovarian torsion in OHSS during the early first trimester. Optimal management of ovarian torsion during pregnancy needs to be explored for these patients. CONCLUSION: Immediate explorative laparoscopic surgery is a potentially safe and useful strategy for treating ovarian torsion during the early first trimester of pregnancy.

Molecular structure and function analysis of bikunin on down-regulation of tumor necrosis factor-alpha expression in activated neutrophils.

OBJECTIVE: We performed a detailed molecular analysis of bikunin-mediated anti-inflammation (suppressive effect of cytokine release, MAP kinase activation, and nuclear translocation of NF-kB) using a truncated form of bikunin. MATERIALS AND METHODS: We obtained bikunin derivatives that contained O-glycoside-linked N-terminal glycopeptide (Bik-m1), N-glycoside-linked C-terminal tandem Kunitz domains (Bik-m2), bikunin lacking O-glycoside (Bik-c), asialo bikunin (Bik-a), bikunin lacking N-glycoside (Bik-n), and purified C-terminal Kunitz domain II (kII) of bikunin (HI-8). Enzyme-linked immunosorbent assay and Western blot were carried out to measure secreted TNF-alpha and MAP kinase activation. RESULTS: We examined the TNF-alpha secretion in control and lipopolysaccharide (LPS)-treated neutrophils and did not see any changes of its protein levels in the cells pretreated with Bik-m1, Bik-m2, Bik-c, or HI-8. In all of the derivatives tested, only the derivatives that lacked N-glycoside side chain showed a significant suppression of TNF-alpha secretion by LPS. Only a small (21 amino acids) deletion of the N-terminal portion of bikunin (which corresponds to Bik-m2) abolished its suppressing activity of TNF-alpha secretion, thus suggesting that the N-terminal 21 amino acids play a critical role in anti-inflammation. Bik-m1 alone failed to show anti-inflammatory response. Bikunin failed to inhibit ionomycin-induced phosphorylation of MAP kinases. CONCLUSION: These data allow us to conclude that the cytokine expression was inhibited only by the O-glycoside-linked core protein without the N-glycoside side chain. Our results also suggest a possible role of bikunin for receptor-dependent MAP kinase activation.