Biomedical subjects

A Steinborn

Publications and source records attributed to A Steinborn.

26 records · Page 2Linked to original sources

PubMed1990

The role of the Thomsen-Friedenreich antigen as a tumor-associated molecule.

The Thomsen-Friedenreich antigen (Gal-GalNAc) represents a tumor-associated molecule, which is assumed to be one of the few chemically well-defined antigens with a proven association with malignancy. In order to analyze the role of the carbohydrate structure Gal-GalNAc for gastrointestinal tumors, we immunized Balb/c mice with MCF-7 breast tumor cells together with synthetic Gal-GalNAc linked to a BSA carrier. One monoclonal antibody (82-A6) was established which recognizes the Thomsen-Friedenreich antigen according to the biochemical and serological analysis presented here. In contrast to the studies performed in the past, immunohistochemical results using this antibody 82-A6 did not exhibit a reactivity clearly restricted to tumors. Preliminary biochemical analysis revealed that the T-determinant is detectable in the high-molecular weight range (about 1000 kD), suggesting that the Gal-GalNAc epitope is found on mucinlike glycoproteins. Tumor restriction of Thomsen-Friedenreich antigen may therefore be determined either by the protein backbone or by the beta-glycosidic linkage of the carbohydrate structure to the protein.

Antibodies↗

PubMedDate not supplied

Signal for term parturition is of trophoblast and therefore of fetal origin.

Up to now we know, that cytokines are key intermediates in the mechanisms, responsible for intrauterine activation in case of intra amniotic infection. The aim of our study was to investigate the role of cytokine- and prostaglandin production in normal term labor. Release of Il-6, Il-1 beta, TNF-alpha, PGE2, PGF2 alpha, was monitored in vaginal secretions originating from uterine cavity, cervix and vagina during normal course of labor. Cells from fetal membranes, decidua and villous trophoblast, obtained from placentas of patients after spontaneous delivery (n = 12), or without labor, after elective cesarean section (n = 12), were cultured, in order to identify cytokine and prostaglandin producing cells. In all cases, term labor and parturition was associated with strongly elevated cytokine- and prostaglandin concentrations in cervical secretions. Cell culture experiments clearly demonstrated, that cells from villous trophoblast, cultured after spontaneous delivery produced significantly more cytokines and prostaglandins than cells form villous trophoblast, cultured after elective cesarean section. Cells from fetal membranes also produced more Il-6 and PGE2 after labor. In contrast to that, cells from decidua produced similar amounts of cytokines and prostaglandins before and after spontaneous term labor. Therefore we conclude, that the signal for term labor and delivery is of trophoblast and so of fetal origin.

Amniotic Fluid↗

PubMedDate not supplied

Expression of cytokine receptors in the placenta in term and preterm labour.

Elevated uterine concentrations of interleukin-1beta (IL-1beta), interleukin-6 (IL-6) and tumour-necrosis factor-alpha (TNF-alpha) are suspected to cause increased prostaglandin release from gestational tissues, but little information is available about the expression pattern of cytokine receptors in these tissues. In this study, cytokine receptor positive cells in frozen tissue sections of placentae (n=70) and fetal membranes (n=50) were identified by immunohistological staining with monoclonal antibodies specific for IL-6 receptor, TNF receptors I and II, and IL-1 receptor I. Both subunits of the IL-6 receptor (gp130 and gp80) as well as TNF receptors I and II were expressed by fetal endothelial cells within placental villi, while IL-1-receptor I was detected exclusively in stromal cells of the maternal decidua. The IL-1 receptor I and TNF receptors I and II were expressed in both uterine quiescence and labour, irrespective of gestational age. Immunoreactivity of the gp130 subunit of the IL-6 receptor was found also throughout pregnancy, while the appearance of the gp80 subunit correlated with the presence of term and preterm labour. In case of preterm labour, expression of the gp80 subunit was predominantly detected in the absence of intrauterine infection. Therefore, it is concluded that the de novo expression of the gp80 subunit and consequently the appearance of entire IL-6 receptors in the placenta is associated with spontaneously occurring labour at term and also with preterm occurring labour in the absence of inrauterine infection.

Adult↗

PubMedDate not supplied

[Intercellular adhesion molecular 1, a diagnostic serum marker in chorioamnionitis, pre-eclampsia and HELLP syndrome].

INTRODUCTION: Chorioamnionitis and pregnancy-induced hypertension both are extremely feared complications of human pregnancy. Activation or disturbance of normal endothelial cell function may be involved in the pathogenesis of both kinds of disease. The aim of our study was to compare the diagnostic value of soluble intercellular-adhesion-molecule-1 (ICAM-1) with that of C-reactive protein (CRP) and white blood cell count for the detection of chorioamnionitis in patients with preterm labor. In addition, we examined if concentrations of ICAM-1 were also increased in case of preeclampsia or HELLP-syndrome. MATERIALS AND METHODS: ICAM-1, CRP and leucocyte count were estimated in 50 cases of normal term delivery, 97 cases of uncontrollable preterm labor, 16 cases of preeclampsia and 9 cases of HELLP-syndrome before delivery. RESULTS: From 97 women delivering preterm, chorioamnionitis was histologically confirmed for 48 women. Maternal serum levels of ICAM-1 (p < 0.001), CRP (p < 0.001) and leucocyte count (p < 0.02) were significantly higher in the group of preterm delivering patients (< 37 weeks gestation) with histologically confirmed chorioamnionitis in comparison to preterm delivering patients in the absence of chorioamnionitis. In the group of patients delivering preterm (< 37 weeks gestation) because of preeclampsia or HELLP-syndrome, ICAM-1 (p < 0.001), as well as CRP (p < 0.006) concentrations were also significantly increased in comparison to patients delivering preterm in the absence of chorioamnionitis. CONCLUSIONS: Elevated levels of ICAM-1 in the serum of pregnant women may be considered as an important risk factor for the development of complications in pregnancy associated with inflammatory induced changes of maternal endothelial cell functions.

Adult↗

PubMedDate not supplied

3D real-time imaging of the fetal heart.

OBJECTIVE: The aim of this study was to evaluate the clinical utility of a novel 3D scanner system for real-time 3D fetal echocardiography. METHOD: In a prospective study, 13 single, healthy 20- to 24-week-old fetuses were examined with conventional 2D and real-time 3D echocardiography. The visualization rates and imaging quality of standard cardiac views were compared between both methods. RESULTS: The visualization rates of standard cardiac planes were found to be slightly increased and more easily obtainable in 3D imaging whereas the image quality showed better results with conventional 2D echocardiography. CONCLUSION: Our data show that real-time 3D fetal echocardiography can be considered a useful tool in the evaluation of the fetal heart with the necessity for further refinement of the resolution quality

Echocardiography↗

PubMedDate not supplied

Evaluation of two-dimensional versus three-dimensional ultrasound in obstetric diagnostics: a prospective study.

OBJECTIVES: We aimed to find answers to the following questions: What are the technical and biological prerequisites for easily obtainable three-dimensional (3D) images? What are the visualization rates for various fetal organ systems? What is the potential for assessing fetal malformations? What are the psychological effects of 3D imaging on the expectant mothers? METHODS: Between January and June 1998, 433 pregnant women were prospectively examined with two-dimensional (2D) and 3D sonography. RESULTS: 3D visualization in healthy fetuses was inferior in quality to 2D visualization, which also accounted for the comparison of 3D imaging versus 2 D imaging among fetuses affected with malformations. In only 1 case did 3D imaging yield a slightly better description of the given malformation. This did not result in a different therapeutical approach. Concerning the psychological effect of 3D imaging, a marked approval of the 3D method was recorded. CONCLUSIONS: These results show that the image information acquired by 3D ultrasound technology is nearly always inferior to the image information obtained by conventional 2D imaging. 3D imaging can be useful for specific malformations under the condition that these examinations be performed in specific ultrasound departments. Thus, a clearly defined range of indications can be assigned to 3D imaging.

Congenital Abnormalities↗

PubMedDate not supplied

[Cytokines in the diagnosis of amniotic infection syndrome].

Accumulating evidence indicates an association between intraamniotic infection and raising concentrations of amniotic cytokines, resulting in preterm labor and preterm rupture of fetal membranes, because these cytokines are able to stimulate prostaglandin biosynthesis. Therefore the purpose of our study was to investigate if quantitative determination of Il-1 beta, Il-6, Il-8 and TNF-a in amniotic fluid may be a practicable method to diagnose intraamniotic infection. Since invasive amniocentesis doesn't allow repeated cytokine detection, in case of preterm rupture of fetal membranes, amniotic fluid also was obtained by placing a sterile gauze and cotton pad into the women's vagina, absorbing draining amniotic fluid for cytokine detection. Our results clearly indicate that Il-1 beta and TNF-a are not detectable in normal pregnancy, while Il-6 and Il-8 are produced in low, but constant levels. In contrast, in amniotic fluid of patients with intraamniotic infection high amounts of Il-6 and Il-8 were found, while Il-1 beta and TNF-a bioactivity became measurable, indicating that biosynthesis was activated. These results demonstrate, that infection associated cytokines detectable in amniotic fluid are highly sensitive markers for intraamniotic infection. In case of preterm rupture of fetal membranes recovery of amniotic fluid from a vaginal pad allows monitoring of cytokine bioactivity in daily intervals to control success of antibiotic treatment.

Adult↗

PubMedDate not supplied

[Prenatal chromosome analysis using the FISH technique allows fetal aneuploidy detection within a few hours].

Last years evaluation of fluorescence-in-situ-hybridization (FISH) allowed detection of chromosomal abnormalities by using DNA probes, binding to chromosomes in the nucleus. Because it is possible to directly examine interphase nuclei, FISH-technique, in contrast to traditional cytogenetic analysis has the advantage of small loss of time in case of urgent decisions on perinatal management. Karyotyping was performed on fetal cells, obtained from 72 pregnancies after amniocentesis, by both classical cytogenetics and fluorescence in situ hybridization using commercially available kits which utilise the alpha satellite probes for chromosomes 13 + 21 and 18. The classical cytogenetics demonstrated that the fetal karyotype was normal in 67 cases and abnormal in 5 cases (four with trisomy 21 and one with a translocation trisomy 18). With the FISH-technique it was possible to obtain accurate diagnosis of trisomy 21 within 24 hours of sampling. The distribution of the number of signals in the chromosomally normal and abnormal fetuses was significantly different, but we were not able to identify the fetus with translocation trisomy 18. We conclude that in the investigation of fetuses with ultrasonographic diagnosed malformations, FISH provides a rapid technique for detection of numerical chromosomal aberrations, but replacement of classical cytogenetics is not possible because of its limitations for identification of subtle structural chromosomal abnormalities.

Amniocentesis↗