Co-expression of transcription factor AP-2beta (TFAP2B) and GATA3 in human mammary epithelial cells with intense, apicobasal immunoreactivity for CK8/18.

AP-2ß is a new mammary epithelial differentiation marker and its expression is preferentially retained and enhanced in lobular carcinoma in situ and invasive lobular breast cancer. In normal breast epithelium AP-2ß is expressed in a scattered subpopulation of luminal cells. So far, these cells have not been further characterized. Co-expression of AP-2ß protein and luminal epithelium markers (GATA3, CK8/18), hormone receptors [estrogen receptor (ER), androgen receptor (AR)] and candidate stem cells markers (CK5/14, CD44) were assessed by double-immunofluorescence staining in normal mammary gland epithelium. The subpopulation of AP-2ß-positive mammary epithelial cells showed an almost complete, superimposable co-expression with GATA3 and a peculiar intense, ring-like appearing immunoreactivity for CK8/18. Confocal immunofluorescence microscopy revealed an apicobasal staining for CK8/18 in AP-2ß-positive cells, which was not seen in in AP-2ß-negative cells. Furthermore, AP-2ß-positive displayed a partial co-expression with ER and AR, but lacked expression of candidate stem cell markers CK5/14 and CD44. In summary, AP-2ß is a new luminal mammary epithelial differentiation marker, which is expressed in the GATA3-positive subpopulation of luminal epithelial cells. These AP-2ß-positive/GATA3-positive cells also show a peculiar CK8/18-expression which may indicate a previously unknown functionally specialized mammary epithelial cell population.

Estimation of neonatal outcome artery pH value according to CTG interpretation of the last 60 min before delivery: a retrospective study. Can the outcome pH value be predicted?

PURPOSE: The aim of this study was to analyze whether the umbilical artery pH value can be estimated throughout CTG assessment 60 min prior to delivery and if the estimated umbilical artery pH value correlates with the actual one. This includes analysis of correlation between CTG trace classification and actual umbilical artery pH value. Intra-and interobserver agreement and the impact of professional experience on visual analysis of fetal heart rate tracing were evaluated. METHODS: This was a retrospective study. 300 CTG records of the last 60 min before delivery were picked randomly from the computer database with the following inclusion criteria; singleton pregnancy >37 weeks, no fetal anomalies, vaginal delivery either spontaneous or instrumental-assisted. Five obstetricians and two midwives of different professional experience classified 300 CTG traces according to the FIGO criteria and estimated the postnatal umbilical artery pH. RESULTS: The results showed a significant difference (p < 0.05) in estimated and actual pH value, independent of professional experience. Analysis and correlation of CTG assessment and actual umbilical artery pH value showed significantly (p < 0.05) diverging results. Intra- and interobserver variability was high. Intraobserver variability was significantly higher for the resident (p = 0.001). No significant differences were detected regarding interobserver variability. CONCLUSION: An estimation of the pH value and consequently of neonatal outcome on the basis of a present CTG seems to be difficult. Therefore, not only CTG training but also clinical experience and the collaboration and consultation within the whole team is important.

Correlation of fetal scalp blood sampling pH with neonatal outcome umbilical artery pH value.

PURPOSE: Fetal scalp blood sampling is considered as a complimentary tool in addition to cardiotocography to assess fetal well-being. This blood sampling is important as the obstetrician has to judge and make decisions regarding the further management of the delivery based on this pH result. The aim of this study was to analyze the correlation between fetal scalp blood pH and the umbilical artery pH after birth. Furthermore, it was investigated whether tocolysis, a performed episiotomy or cord encirclement have an influence on the umbilical artery pH. METHODS: This retrospective study over a period of 11 years included all singleton pregnancies without fetal anomalies, which were monitored by fetal scalp blood sampling during labor. RESULTS: 844 out of 1502 deliveries were included for analysis. The analysis demonstrates a good correlation between fetal scalp pH value and outcome pH value. Subgroup analysis with fetal scalp blood pH <7.20 showed a difference in 40 of 82 cases, with an outcome pH value ≥7.20, but this difference was statistically insignificant. Neither did tocolysis, episiotomy or the presence of cord encirclement show an overall effect, nor did they have an impact on the subgroup. CONCLUSION: Obstetricians must consider that the values of fetal scalp blood are not always reliable and can be false. However, on the basis of CTG and fetal scalp blood pH, decisions are made regarding delivery interventions. Therefore, we would encourage the consideration of taking two samples routinely at every attempt of fetal blood sampling.

The role of calcium in Chlamydomonas photomovement responses as analysed by calcium channel inhibitors.

Phototaxis and light-induced stop responses in Chlamydomonas are known to be calcium dependent. We show that phototaxis is stereoselectively inhibited by dihyropyridines, verapamil, diltiazem, omega-conotoxin and pimozide, all inhibitors of slow L-type calcium channels. In contrast, the stop response in Chlamydomonas can be specifically reduced only by omega-conotoxin and pimozide. The light-regulated calcium uptake as detected by 45calcium can be completely suppressed by verapamil and omega-conotoxin but not by diltiazem or any of the dihyropyridine-type calcium channel inhibitors. We conclude that phototaxis and stop response in Chlamydomonas are regulated by three distinguishable drug receptor sites. One of them controls phototaxis and is sensitive to verapamil. The second site controls stop response and phototaxis and shows a high sensitivity to omega-conotoxin and pimozide. These two drug receptors seem to be localized in the plasma membrane and function as ion channels. In addition, calcium influences internal signal transduction from the photoreceptor to the flagella. This internal role of calcium is inhibited by the dihydropyridine binding to a dihydropyridine receptor protein. The arylazide-1,4-dihydropyridine[3H]azidopine binds with a Kd = 35 nM to a 50 kDa protein located in one of the internal cell membranes. Azidopine binding is fully reversible and can be partially inhibited by nimodipine and PN-200110. This protein is the first identified dihyropyridine receptor in an unicellular plant cell. It might serve as an internal calcium regulating channel in Chlamydomonas.