Biomagnetic activity and non linear analysis in obstetrics and gynecology in a Greek population.

This article reports the application of non-linear analysis to biomagnetic signals recorded from fetal growth restriction, fetal brain activity, ovarian lesions, breast lesions, umbilical arteries, uterine myomas, and uterine arteries in a Greek population. The results were correlated with clinical findings. The biomagnetic measurements and the application of non-linear analysis are promising procedures in Obstetrics and Gynecology.

Regulation of Rho GTPases by p120-catenin.

Three recent reports indicate that p120-catenin can modulate the activities of RhoA, Rac and Cdc42, suggesting an elegant and previously unexpected mechanism for regulating the balance between adhesive and motile cellular phenotypes. The observations in these reports provide important new clues toward p120's mechanism of action and provide a potential explanation for the metastatic phenotype exhibited in carcinoma cells that have lost E cadherin expression.

Inhibition of RhoA by p120 catenin.

RhoA organizes actin stress fibres and is necessary for cell transformation by oncogenes such as src and ras. Moreover, RhoA is implicated in cadherin clustering during the formation of adherens junctions. The catenin p120 has also been implicated in cadherin clustering through an unknown mechanism. Here we show that p120 selectively inhibits RhoA activity in vitro and in vivo. RhoA inhibition and the interaction of p120 with cadherins are mutually exclusive, suggesting a mechanism for regulating the recruitment and exchange of RhoA at nascent cell-cell contacts. By affecting RhoA activation, p120 could modulate cadherin functions, including suppression of invasion, neurite extension and junction formation.

Three-dimensional microscale hanging drop arrays with geometric control for drug screening and live tissue imaging.

Existing three-dimensional (3D) culture techniques are limited by trade-offs between throughput, capacity for high-resolution imaging in living state, and geometric control. Here, we introduce a modular microscale hanging drop culture where simple design elements allow high replicates for drug screening, direct on-chip real-time or high-resolution confocal microscopy, and geometric control in 3D. Thousands of spheroids can be formed on our microchip in a single step and without any selective pressure from specific matrices. Microchip cultures from human LN229 glioblastoma and patient-derived mouse xenograft cells retained genomic alterations of originating tumors based on mate pair sequencing. We measured response to drugs over time with real-time microscopy on-chip. Last, by engineering droplets to form predetermined geometric shapes, we were able to manipulate the geometry of cultured cell masses. These outcomes can enable broad applications in advancing personalized medicine for cancer and drug discovery, tissue engineering, and stem cell research.

Selective uncoupling of p120(ctn) from E-cadherin disrupts strong adhesion.

p120(ctn) is a catenin whose direct binding to the juxtamembrane domain of classical cadherins suggests a role in regulating cell-cell adhesion. The juxtamembrane domain has been implicated in a variety of roles including cadherin clustering, cell motility, and neuronal outgrowth, raising the possibility that p120 mediates these activities. We have generated minimal mutations in this region that uncouple the E-cadherin-p120 interaction, but do not affect interactions with other catenins. By stable transfection into E-cadherin-deficient cell lines, we show that cadherins are both necessary and sufficient for recruitment of p120 to junctions. Detergent-free subcellular fractionation studies indicated that, in contrast to previous reports, the stoichiometry of the interaction is extremely high. Unlike alpha- and beta-catenins, p120 was metabolically stable in cadherin-deficient cells, and was present at high levels in the cytoplasm. Analysis of cells expressing E-cadherin mutant constructs indicated that p120 is required for the E-cadherin-mediated transition from weak to strong adhesion. In aggregation assays, cells expressing p120-uncoupled E-cadherin formed only weak cell aggregates, which immediately dispersed into single cells upon pipetting. As an apparent consequence, the actin cytoskeleton failed to insert properly into peripheral E-cadherin plaques, resulting in the inability to form a continuous circumferential ring around cell colonies. Our data suggest that p120 directly or indirectly regulates the E-cadherin-mediated transition to tight cell-cell adhesion, possibly blocking subsequent events necessary for reorganization of the actin cytoskeleton and compaction.

Hypertensive disorders in pregnancy: risk factors and epidemiologic analysis.

OBJECTIVE: To measure the incidence of preeclampsia-eclampsia and its perinatal mortality as they appear in the two major ethnic groups in Thrace: Christian Orthodox and Muslims. STUDY DESIGN: Incidence and perinatal mortality of preeclampsia-eclampsia were studied retrospectively on all women managed in our clinic for hypertensive disorders in pregnancy who were delivered of a stillborn or healthy neonate between 1986 and 1999. We also compared the prevalence of certain risk factors of the disease as they appear in the above-mentioned distinct ethnic groups. RESULTS: The total incidence of preeclampsia-eclampsia in Thrace was 2.3% and the total perinatal mortality 6.4%. Both variables presented higher values and severe preeclampsia-eclampsia had greater prevalence in the Muslim population. Most risk factors presented statistically significant differences between Christians and Muslims (chi2 test, p < 0.05). CONCLUSIONS: There was an ethnic variation in most epidemiologic variables of hypertensive disorders in Thrace between Christians and Muslims.

Biomagnetism in perinatal medicine. Our experience in Greece.

This is a report on our experience in the application of biomagnetism in perinatal medicine. We provide a brief description of our research work in fetal magnetoencephalography and fetal magnetocardiography in normal, preeclamptic and IUGR pregnancies, together with hemodynamics of the umbilical cord and uterine arteries, providing a new approach to biomagnetism as a non invasive imaging modality in the investigation of perinatal complications.

Magnetic field profiles in normal human breast during the menstrual cycle.

OBJECTIVE: To investigate the subtle magnetic fields produced by living normal breast tissue during the menstrual cycle. METHODS: The magnetic activity of the breast was recorded in four young women, 26-28 years old; two had regular and two irregular menstrual cycles. The recordings were accomplished with a biomagnetometer and covered two complete menstrual cycles. The results were correlated with estrogen and progesterone levels on days 7, 14 and 21 of the menstrual cycle. RESULTS: The magnetic breast recordings in the two young women with the regular cycling endometrium showed a biphasic magnetic curve, apparently corresponding to the proliferative and secretory phase of the menstrual cycle. By contrast, the two young women with irregular menstrual cycles showed a monophasic magnetic curve. CONCLUSION: It is suggested that a biphasic, but not a monophasic, pattern of magnetic activity in the breast is indicative of an ovulatory endometrial cycle.

Biomagnetism in gynaecologic oncology. Our experience in Greece.

Our experience in the application of biomagnetism in gynaecologic oncology is presented. We provide a brief description of our research work in the investigation of biomagnetic activity in benign and malignant ovarian and breast diseases, and an evaluation of uterine myomas, providing a new approach of biomagnetism as a non invasive imaging modality for assessing gynaecologic tumours.

Magnetoencephalography and magnetocardiography in neonates. Our experience in Greece.

This study reports our experience in the application of magnetoencephalography (MEG) and magnetocardiography (MCG) in neonates. Results gained from our studies, lead us to believe that MEG and MCG could provide clinical practice with non-invasive, rapid and easy to perform methods, which could be adjuncts to conventional methods for the evaluation of neonatal brain and heart function.

Epidemiology of congenital anomalies in different ethnicities.

PURPOSE OF INVESTIGATION: To study the prevalence and the epidemiologic characteristics of major congenital anomalies (MCAs) in two different populations in Thrace-Greece. METHODS: The ethnic origin of all mothers who delivered in our department and the types of MCAs were determined. We compared the frequencies of MCAs between Christians and Muslims. The chi-square test, t-test, binary and multinomial logistic regression analysis were performed. RESULTS: The prevalence of MCAs was significantly higher in Muslims as compared to Christians (51/4,028 (12.78%) vs 49/5,994 (8.17%), p = 0.035). However, the frequencies of each type of MCA in the total number of deliveries between the two groups did not differ significantly. The central nervous system malformations were most frequently associated with perinatal mortality. CONCLUSION: This is the first study in Greece showing that there is probably a higher prevalence of MCAs in Muslims as compared to Christians, although it can not be elucidated whether this increased risk is related to specific differences between them.

Vasoactive intestinal peptide induces both tyrosine hydroxylase activity and tetrahydrobiopterin biosynthesis in PC12 cells.

Vasoactive intestinal peptide plays an important role in the trans-synaptic activation of tyrosine hydroxylase in sympathoadrenal tissues in response to physiological stress. Since tyrosine hydroxylase is thought to be subsaturated with its cofactor, tetrahydrobiopterin, we tested the hypothesis that up-regulation of tyrosine hydroxylase gene expression following vasoactive intestinal peptide treatment is accompanied by a concomitant elevation of intracellular tetrahydrobiopterin biosynthesis. We also investigated the second messenger systems involved in vasoactive intestinal peptide's effects on tetrahydrobiopterin metabolism. Our results demonstrate that treatment of PC12 cells for 24 h with vasoactive intestinal peptide induced intracellular tetrahydrobiopterin levels 3.5-fold. This increase was due to increased expression of the gene encoding GTP cyclohydrolase, the initial and rate-limiting enzyme in tetrahydrobiopterin biosynthesis, which was blocked by the transcriptional inhibitor, actinomycin D. Activation of tyrosine hydroxylase and GTP cyclohydrolase by vasoactive intestinal peptide was mediated by cyclic-AMP. Furthermore, stimulation of cyclic-AMP-mediated responses or protein kinase C activity induced the maximal in vitro activities of both tyrosine hydroxylase and GTP cyclohydrolase; the responses were additive when both treatments were combined. Induction of sphingolipid metabolism had no effect on the activation of tyrosine hydroxylase, while it induced GTP cyclohydrolase in a protein kinase C-independent manner. Our results support the hypothesis that intracellular tetrahydrobiopterin levels are tightly linked to tyrosine hydroxylation and that tetrahydrobiopterin bioavailability modulates catecholamine synthesis.

Influence of tetrahydrobiopterin on serotonin synthesis, metabolism and release in synaptosomes.

The effects of (6R)-5,6,7,8-tetrahydro-l-biopterin (BH(4)) on the uptake of tryptophan, its conversion to serotonin (5-HT) and 5-hydroxyindoleacetic acid and on the basal release of 5-HT was studied in rat brain synaptosomes. When BH(4), the essential cofactor for tryptophan hydroxylase, was incubated with synaptosomes in concentrations varying from 10 to 200 ?M, there was no effect on 5-HT formation, metabolism or release. Concentrations of 1-2 mM BH(4) had strong inhibitory effects on 5-HT synthesis. The incubation of synaptosomes with tryptophan increased the synthesis of 5-HT, but BH(4) did not further increase this effect. BH(4) was taken up into synaptosomes in a concentration-dependent manner under all incubation conditions and was stable in the chemically reduced (tetrahydro-) form. These results indicate that increases in the synaptosomal concentration of BH(4) do not increase the synthesis and release of 5-HT. It is concluded from the present results that tryptophan hydroxylase is saturated with BH(4) in synaptosomes.

Endometrial carcinoma: association of steroid hormone receptor expression with low angiogenesis and bcl-2 expression.

In endometrial tissues, malignant change may be accompanied by a loss of hormone dependence which is, usually, reflected in a parallel loss of oestrogen and progesterone receptors (ER and PR). In this study, the steroid receptor status of 164 endometrial carcinomas was related to intratumoural angiogenesis and the apoptotic proteins bcl-2 and p53. Relationships to conventional histopathological features and patient survival were also sought. Immunohistochemistry was performed on formalin-fixed, paraffin-embedded tissues. The mean follow-up was 55 months (range 19-167 months). Specific nuclear staining for ER and PR was detected in 35% and 32% of endometrial carcinomas, respectively, and was very commonly co-expressed (P<0.0001). The failure of demonstrating a steroid receptor complement in endometrial neoplasms was, in general terms, an adverse prognostic sign. Thus, ER or PR loss was significantly associated with non-endometrioid carcinomas (ER P=0.01; PR P=0.004) and with deep myometrial invasion (ER P<0.0002), high intratumoural angiogenesis (PR P<0.01) and the absence of bcl-2 expression (PR P<0.005). There was a trend for patients with ER or simultaneous ER/PR expression to have an improved survival, but this association did not reach the level of statistical significance. In multivariate analysis (all stages), tumour cell type (endometrioid versus non-endometrioid carcinomas) and stage of disease were the only variables associated with prognosis (P=0.01 and P<0.0001, respectively), with tumour cell type retaining its independent prognostic value and within stage-I endometrial carcinomas (P=0.02). It is suggested that the loss of steroid hormone receptors in endometrial carcinomas is associated with a more aggressive phenotype and the switching-on of angiogenic pathways.

Tetrahydrobiopterin uptake into rat brain synaptosomes, cultured PC12 cells, and rat striatum.

The uptake of (6R)-5,6,7,8-tetrahydro-L-biopterin (BH4) was investigated in rat brain synaptosomes, cultured rat pheochromocytoma (PC12) cells, and rat striatum (control and depleted of dopamine neurons) following peripheral administration. A linear, non-saturable, concentration-dependent intracellular accumulation was observed when BH4 was added to either synaptosomes or PC12 cells. The uptake of BH4, in contrast to that of serotonin uptake into synaptosomes or norepinephrine (NE) uptake into PC12 cells, was not dependent on glucose or extracellular sodium. Stimulation of tryptophan hydroxylation in synaptosomes by incubation with 5 microM tryptophan (which increases utilization of BH4 in serotonergic cells) did not alter BH4 uptake. In rats with unilateral 6-hydroxydopamine (6-OHDA) lesions of dopamine neurons, BH4 uptake was the same in control and lesioned striatum following peripheral administration. These results indicate that neurons and PC12 cells do not appear to have a specific membrane carrier for BH4 and that BH4 uptake into cells is due to passive diffusion.

Regulation of tyrosine hydroxylase and tetrahydrobiopterin biosynthetic enzymes in PC12 cells by NGF, EGF and IFN-gamma.

The regulation of catecholamine and tetrahydrobiopterin synthesis was investigated in cultured rat pheochromocytoma PC12 cells following treatments with nerve growth factor (NGF), epidermal growth factor (EGF) and interferon-gamma (IFN-gamma). NGF and EGF, but not IFN-gamma, caused an increase after 24 h in the levels of BH4 and catecholamines, and the activities of tyrosine hydroxylase and GTP cyclohydrolase, the rate-limiting enzymes in catecholamine and BH4 synthesis, respectively. Actinomycin D, a transcriptional inhibitor, blocked treatment-induced elevations in tyrosine hydroxylase and GTP cyclohydrolase activities. NGF, EGF or IFN-gamma did not affect the activity of sepiapterin reductase, the final enzyme in BH4 biosynthesis. Rp-cAMP, an inhibitor of cAMP-mediated responses, blocked the induction of tyrosine hydroxylase by NGF or EGF; inhibition of protein kinase C partially blocked the EGF effect, but not the NGF effect, NGF also induced GTP cyclohydrolase in a cAMP-dependent manner, while the EGF effect was not blocked by Rp-cAMP or protein kinase C inhibitors. Sphingosine induced GTP cyclohydrolase in a protein kinase C-independent manner without affecting tyrosine hydroxylase activity. Our results suggest that both tyrosine hydroxylase and GTP cyclohydrolase are induced in a coordinate and transcription-dependent manner by NGF and EGF, while conditions exist where the induction of tyrosine hydroxylase and GTP cyclohydrolase is not coordinately regulated.

Biomagnetic activity in ovarian lesions.

UNLABELLED: BACKGROUND-MATERIALS: This study aimed to investigate biomagnetic activity in benign and malignant ovarian diseases using the biomagnetometer SQUID. Magnetic recordings were obtained from 40 patients with palpable ovarian lesions. 19 of these were invasive carcinomas, and 21 were benign ovarian lesions. METHODS: We used a one channel biomagnetometer SQUID (superconducting quantum interference device), in order to measure the magnetic field from benign and malignant ovarian diseases. RESULTS: Interestingly, the ovarian lesion waveforms and the corresponding spectral densities were of high amplitude in most (96%) malignant ovarian lesions, and of low amplitude in most (95%) benign ovarian diseases. These findings were of statistical significance (students t-test p < 0.005). CONCLUSIONS: It is suggested that biomagnetic measurement of benign and malignant ovarian diseases, which is an entirely new application of SQUID technology, is a promising procedure for assessing ovarian tumors.

The prognostic significance of AgNOR counts in lymph node deposits of breast carcinomas.

Low AgNOR counts in metastatic lymph node deposits confer a longer 5-year survival rate in patients with breast carcinoma compared with those having high AgNOR counts. This was demonstrated in a series of 30 axillary lymph nodes from an equal number of patients with malignant breast disease. The beneficial effect of the low AgNOR status was independent of tumour differentiation, tumour size and the patients' age using univariate analysis, but it was related to the number of lymph nodes with metastatic disease. It is thought that AgNOR counts in axillary lymph node metastases may be an additional prognostic variable in assessing breast tumour behaviour.

Mast cell distribution and density in the normal uterus--metachromatic staining using lectins.

This study investigates the number and the distribution of mast cells in the normal human uterus. Reliability of results was ensured by prompt tissue fixation and the use of biotin-labelled lectins in conjunction with the avidin-biotin peroxidase complex (ABC) method. This design revealed that mast cells are, indeed, normal constituents of the human uterus. They occur in large numbers in the myometrium, but are only scanty in the endometrium where they tend to be confined to the stratum basalis. The mean mast cell counts per high power field (MC/HPF), after staining with Canavalia ensiformis agglutinin (Con A), were 17.9MC/HPF in the inner half of the myometrium, and 8.3MC/HPF in the outer half of the myometrium; 2.7MC/HPF in the basalis, and 0.3MC/HPF in the functionalis (P<0.05). There are no apparent differences in the number of mast cells between the normal proliferative and secretory phase endometrium, however, endometrial mast cells are considerably reduced and, apparently, depleted of metachromatic granules during the immediate pre-menstrual phase of the menstrual cycle. It is presumed that this, almost exclusive, presence of mast cells in the basal layer of the endometrial matrix, combined with the discharge of their cytoplasmic granules towards the end of the cycle, may be related with the contracting process preceding menstruation. On the other hand, the relative paucity of mast cells in the functional layer may contribute to the immune tolerance of the gestational endometrium to the implantation of the blastocyst.

Nonlinear analysis of biomagnetic signals recorded from the umbilical artery in normal and pre-eclamptic pregnancies.

OBJECTIVE: In this study we investigated the hemodynamics of the feto-placental circulation in normal and pre-eclamptic near term pregnancies using the biomagnetometer SQUID. Thirteen abnormal and 25 normal pregnancies were included in this study. STUDY DESIGN: The biomagnetic signals were analyzed using nonlinear analysis in order to differentiate these two types of pregnancies. RESULTS: The application of nonlinear analysis reveal a clear saturation dimension value for pre-eclamptic and non-saturation for normal pregnancies. These findings were statistically significant and were correlated with fetal heart rate monitoring, pH and Apgar score: high biomagnetic cases (140-300 fT/square root Hz) were related with normal patterns, pH>7.25 and Apgar >7, while low biomagnetic recordings (50-110 fT/square root Hz) were connected with abnormal patterns, pH<7.25 and Apgar <7. CONCLUSIONS: It is suggested that the biomagnetic measurements with SQUID and the application of nonlinear analysis, is a promising procedure in assessing fetal health, especially in high risk pregnancies.