First-trimester pre-eclampsia biomarker profiles in Asian population: multicenter cohort study

OBJECTIVES

To (i) evaluate the applicability of the European-derived biomarker multiples of the median (MoM) formulae for risk assessment of preterm pre-eclampsia (PE) in seven Asian populations, spanning the east, southeast and south regions of the continent, (ii) perform quality-assurance (QA) assessment of the biomarker measurements and (iii) establish criteria for prospective ongoing QA assessment of biomarker measurements.

METHODS

This was a prospective, non-intervention, multicenter study in 4023 singleton pregnancies, at 11 to 13 + 6 weeks' gestation, in 11 recruiting centers in China, Hong Kong, India, Japan, Singapore, Taiwan and Thailand. Women were screened for preterm PE between December 2016 and June 2018 and gave written informed consent to participate in the study. Maternal and pregnancy characteristics were recorded and mean arterial pressure (MAP), mean uterine artery pulsatility index (UtA-PI) and maternal serum placental growth factor (PlGF) were measured in accordance with The Fetal Medicine Foundation (FMF) standardized measurement protocols. MAP, UtA-PI and PlGF were transformed into MoMs using the published FMF formulae, derived from a largely Caucasian population in Europe, which adjust for gestational age and covariates that affect directly the biomarker levels. Variations in biomarker MoM values and their dispersion (SD) and cumulative sum tests over time were evaluated in order to identify systematic deviations in biomarker measurements from the expected distributions.

RESULTS

In the total screened population, the median (95% CI) MoM values of MAP, UtA-PI and PlGF were 0.961 (0.956-0.965), 1.018 (0.996-1.030) and 0.891 (0.861-0.909), respectively. Women in this largely Asian cohort had approximately 4% and 11% lower MAP and PlGF MoM levels, respectively, compared with those expected from normal median formulae, based on a largely Caucasian population, whilst UtA-PI MoM values were similar. UtA-PI and PlGF MoMs were beyond the 0.4 to 2.5 MoM range (truncation limits) in 16 (0.4%) and 256 (6.4%) pregnancies, respectively. QA assessment tools indicated that women in all centers had consistently lower MAP MoM values than expected, but were within 10% of the expected value. UtA-PI MoM values were within 10% of the expected value at all sites except one. Most PlGF MoM values were systematically 10% lower than the expected value, except for those derived from a South Asian population, which were 37% higher.

CONCLUSIONS

Owing to the anthropometric differences in Asian compared with Caucasian women, significant differences in biomarker MoM values for PE screening, particularly MAP and PlGF MoMs, were noted in Asian populations compared with the expected values based on European-derived formulae. If reliable and consistent patient-specific risks for preterm PE are to be reported, adjustment for additional factors or development of Asian-specific formulae for the calculation of biomarker MoMs is required. We have also demonstrated the importance and need for regular quality assessment of biomarker values. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Predictive immunohistochemical features for tumour response to chemoradiotherapy in rectal cancer

Background

Reduced expression of cluster of differentiation (CD) 133 and cyclo‐oxygenase (COX) 2, and increased density of CD8+ tumour‐infiltrating lymphocytes, are associated with a favourable tumour response to preoperative chemoradiotherapy (CRT). This study aimed to evaluate these markers in relation to tumour response after preoperative CRT in two rectal cancer cohorts.

Methods

Patients with low rectal cancer who underwent radical resection and preoperative short‐term CRT in 2001–2007 (retrospective cohort) and long‐term CRT in 2011–2017 (prospective cohort) were analysed. Pretreatment biopsies were stained immunohistochemically using antibodies to determine CD133 and COX‐2 expression, and increased CD8+ density. Outcome measures were tumour regression grade (TRG), tumour downstaging and survival.

Results

For 95 patients in the retrospective cohort, the incidence of TRG 3–4 was 67 per cent when two or three immunohistochemistry (IHC) features were present, but only 20 per cent when there were fewer features (P < 0·001). The incidence of tumour downstaging was higher in patients with at least two IHC features (43 versus 22 per cent with fewer features; P = 0·029). The 49 patients in the prospective cohort had similar rates to those in the retrospective cohort (TRG 3–4: 76 per cent for two or more IHC features versus 25 per cent with fewer features, P < 0·001; tumour downstaging: 57 versus 25 per cent respectively, P = 0·022). Local recurrence‐free survival rates in patients with more or fewer IHC features were similar in the retrospective and prospective cohort (P = 0·058 and P = 0·387 respectively).

Conclusion

Assessment of CD133, COX‐2 and CD8 could be useful in predicting a good response to preoperative CRT in patients with lower rectal cancer undergoing neoadjuvant therapy. Further studies are needed to validate the results in larger cohorts and investigate a survival benefit.

Treatment of twin-reversed arterial perfusion sequence using high-intensity focused ultrasound

We describe our experience of high-intensity focused ultrasound (HIFU) for fetal therapy in twin-reversed arterial perfusion (TRAP) sequence. Six pregnant women underwent HIFU therapy, five before 16 weeks and one at 26 weeks. Two types of HIFU system were used: the first-generation system, which comprised a biaxial transducer and continuous exposure pattern, and the second-generation system, which comprised a coaxial transducer and sequential exposure pattern. The first-generation apparatus was used in four cases and the second-generation apparatus was used in two. In three cases, occlusion of the blood vessels mediating flow to the acardiac twin was achieved by HIFU. Two cases experienced intrauterine fetal death despite vessel occlusion. The total survival rate of pump fetuses 2 years after HIFU was 67% and the efficiency rate (the proportion of cases with occlusion or reduced blood flow on ultrasound after HIFU) was 83%. After more than 2 years of follow-up, the surviving infants had no severe clinical complications and no postnatal developmental problems. There was no significant difference in survival rate compared with TRAP cases managed expectantly. Given that complete occlusion of the blood vessels was not achieved in half of the cases, we could not show that HIFU therapy is superior to other treatments. However, HIFU can reduce the cardiac load of the pump fetus and, as it does not require uterine puncture for fetal therapy, there were no fatal complications, such as bleeding, rupture of membranes or infection. Thus, HIFU therapy may represent a less-invasive treatment for TRAP sequence in early pregnancy. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Prediction of early- and late-onset pregnancy-induced hypertension using placental volume on three-dimensional ultrasound and uterine artery Doppler

OBJECTIVES

To determine whether uterine artery (UtA) Doppler findings and three-dimensional (3D) ultrasound measurement of placental volume during the first trimester allowed prediction of early- and late-onset pregnancy-induced hypertension (early PIH and late PIH).

METHODS

Subjects with singleton pregnancy who underwent an ultrasound scan at 11-13 weeks' gestation and delivered between 2011 and 2013 were enrolled prospectively into the study. The UtA Doppler indices and placental volume on 3D ultrasound at 11-13 weeks' gestation in cases that developed early PIH (< 34 weeks) or PIH later in pregnancy (≥ 34 weeks) were compared with values in unaffected pregnancies.

RESULTS

Ten cases of early PIH, 67 cases of late PIH and 1285 unaffected pregnancies were analyzed. The UtA pulsatility index (PI) was higher in cases of early PIH than that in unaffected pregnancies (median, 2.35 vs. 1.79; P = 0.043) but did not differ between cases of late PIH and unaffected pregnancies. Placental volume was smaller in cases of early PIH than that in unaffected pregnancies (median, 43 cm3 vs. 62 cm(3) ; P = 0.003) but did not differ between cases of late PIH and unaffected pregnancies. The area under the receiver-operating characteristics curve for the prediction of early PIH, by combining UtA-PI and placental volume, was 0.832 (95% CI, 0.742-0.921), with this combination providing a detection rate for early PIH of 67.5% for a 5% false-positive rate.

CONCLUSIONS

High UtA-PI and small placental volume were observed more often in cases of early PIH compared with unaffected pregnancies, but not in cases of late PIH. These results may indicate that there are differences in pathophysiology between early PIH and late PIH.

First successful case of non-invasive in-utero treatment of twin reversed arterial perfusion sequence by high-intensity focused ultrasound

High-intensity focused ultrasound (HIFU) has excellent potential as a non-invasive therapeutic tool in various fields of medicine. We present a case of twin reversed arterial perfusion sequence, in which non-invasive blood flow occlusion in the acardiac fetus was successfully achieved by means of HIFU exposure from outside the maternal abdomen. HIFU was applied to blood vessels of the acardiac fetus at the point at which the umbilical cord entered the body in a series of four procedures at 3-day intervals starting at 13 weeks' gestation, and in a final procedure with higher power at 17 weeks. The HIFU intensity was set at approximately 2300 W/cm(2) for the initial series of procedures and at 4600 W/cm(2) for the final procedure, with exposure periods of 10 s. As color Doppler examination revealed absence of blood flow to the acardiac fetus after the second round of HIFU exposure, we concluded that complete occlusion of target vessels had been achieved. Delivery was by Cesarean section at 37 weeks' gestation. A male neonate (the pump fetus) was born weighing 1903 g with Apgar scores of 8 and 9 at 1 and 5 min, respectively. At the time of writing, the baby was healthy and growing normally, with the exception of congenital pseudarthrosis.

High-intensity focused ultrasound treatment for twin reversed arterial perfusion sequence

Twin reversed arterial perfusion (TRAP) sequence is a serious complication of monochorionic twin pregnancies, in which arterioarterial anastomoses allow blood flow from a 'pump' fetus to an acardiac fetus via reversed flow in the latter's umbilical artery. Several trial treatments for TRAP sequence have been reported, but all of these have been invasive. We present a case of TRAP sequence in which high-intensity focused ultrasound (HIFU) was applied to the umbilical artery of the anomalous twin at 26 weeks as a non-invasive fetal therapy. The HIFU intensity was set at approximately 2300 W/cm(2) with exposure periods of 10 s. Color Doppler ultrasound showed a decrease in blood supply to the anomalous twin, although complete occlusion of the targeted vessel was not achieved. Delivery was by Cesarean section at 29 weeks' gestation and the pump twin survived, without severe clinical complications at 6 months.

Detection of umbilical venous constriction by Doppler flow measurement at midgestation

OBJECTIVES

To investigate whether umbilical venous velocity and venous velocity pulsation are associated with umbilical vein diameter, umbilical ring diameter and umbilical cord coiling index at midgestation.

METHODS

Two hundred and eighty pregnant women were enrolled in the study at between 18 and 24 weeks of gestation. The diameter of the umbilical cord and internal diameter of the umbilical vein in a free loop and at the ring, and the umbilical coiling index, were measured using ultrasonography. Umbilical venous velocities were measured by Doppler ultrasonography at the umbilical ring and a free loop of the cord.

RESULTS

All variables were successfully measured in 92% of the patients. There were negative correlations between the diameters of the umbilical ring and of the umbilical vein at the ring and the venous velocity at the umbilical ring. The venous velocity at the umbilical ring was significantly higher and the umbilical ring diameter was significantly lower in fetuses with umbilical venous pulsation at the free loop. Significant correlations were observed between the venous velocity and amplitude of pulsation. Venous pulsations at the free loop were frequently observed in fetuses with a hypercoiled cord.

CONCLUSION

High venous velocity and increased venous pulsation at the umbilical ring may be associated with umbilical cord constriction.

Predisposing factors for massive hemorrhage during Cesarean section in patients with placenta previa

OBJECTIVES

To investigate whether maternal history and ultrasound findings can be predictors for massive hemorrhage during Cesarean section in patients with placenta previa and adherence of the placenta.

METHODS

We reviewed 127 singleton pregnancies with placenta previa. Maternal history, antenatal ultrasound findings of the placenta, including location, presence of placental lacunae, lack of a clear zone, presence of sponge-like findings of the cervix and presence of a marginal sinus in cases of placenta previa were reviewed retrospectively, and their association with amount of bleeding during Cesarean section was analyzed.

RESULTS

Logistic regression analysis revealed that advanced maternal age (odds ratio (OR), 5.4; 95% CI, 1.8-16.4), previous Cesarean section (OR, 20.4; 95% CI, 4.0-105.2) and sponge-like findings in the cervix (OR, 5.6; 95% CI, 1.8-17.0) were associated with massive bleeding (> 2500 mL). Placental adherence occurred in five cases and was more frequent in cases where the placenta was located at the site of the scar of a previous Cesarean section (OR, 123.1; 95% CI, 4.5-3395.2) and where there was lack of a clear zone (OR, 48.0; 95% CI, 3.8-604.7).

CONCLUSIONS

Advanced maternal age, previous Cesarean section and presence of sponge-like findings in the cervix are risk factors for massive bleeding during Cesarean section in cases of placenta previa, regardless of whether placental adherence is present. Placental location on the scar of a previous Cesarean section and lack of a clear zone are risk factors for placental adherence. When these findings are identified preoperatively, management should be tailored accordingly.

Prospective evaluation of the risk of pre-eclampsia using logistic regression analysis

OBJECTIVES

To calculate the risk of developing pre-eclampsia (PET) in a consecutive series of low-risk women at 18-24 weeks' gestation, using recently published logistic regression models.

METHODS

This was a prospective study, with complete follow-up, in a consecutive series of unselected low-risk singleton pregnancies. Uterine artery pulsatility index as well as a combination of maternal factors were recorded at 18-24 weeks' gestation. The distribution of the estimated risks for the 16 PET patients was compared with that obtained for 136 women who had a normal pregnancy, as assessed by routine testing. A receiver-operating characteristics (ROC) curve was plotted to evaluate the detection rate at fixed false-positive rates (FPRs) of 5%, 10% and 20% and the corresponding odds cut-offs.

RESULTS

Just 1/16 (6.2%) women with PET developed the disease before the 34(th) week of gestation. Using the 'All PET' logistic regression model, for 16 PET cases the overall median odds was 1 : 1454, higher compared with that of 1 : 41635 estimated for controls. Using the 'PET >or= 34 weeks' model, the median odds of the 15 women who developed PET late was 1 : 3405, compared with 1 : 40785 for controls. In the case of PET before 34 weeks, the risk was 1 : 426373 vs. 1 : 4159823126 estimated for controls ('PET < 34 weeks' model). Detection rates for the All PET model were 18%, 50% and 62% at a FPR of 5%, 10% and 20%, respectively. For the PET >or= 34 weeks model these detection rates were 6%, 46% and 60%, respectively.

CONCLUSION

Even though the individual odds estimation is too low to represent the real risk of PET, the recently published logistic regression models detected more than 60% of PET at a FPR of 20% for both All PET and PET >or= 34 weeks models. Using these models in clinical practice does not seem to give any significant improvement over Doppler alone in the prediction of PET, but the use of a PET-specific odds instead of an actual Doppler value alone seems to be useful for clinical management.

Application of high-intensity focused ultrasound for umbilical artery occlusion in a rabbit model

OBJECTIVES

To investigate the application of high-intensity focused ultrasound (HIFU) for fetal umbilical artery blood flow occlusion in a rabbit model.

METHODS

A prototype HIFU transducer in combination with an imaging probe with Doppler capability was constructed. Using this transducer, HIFU was applied at 1.4, 2.75 or 5.5 kW/cm(2) through the maternal abdominal skin to the fetal intra-abdominal umbilical arteries of four time-mated Japanese White rabbits (11 fetuses) on gestational day 25. Courses of 5-s HIFU exposure were performed until cessation of umbilical blood flow and cardiac arrest were confirmed by Doppler ultrasonography. Fetal necropsy was performed and exposed lesions were assessed by microscopic histological analysis.

RESULTS

The mean diameter of the fetal umbilical artery was 0.6 +/- 0.2 mm and the mean peak systolic velocity of arterial blood flow was 44.7 +/- 18.5 cm/s. When HIFU was applied at 5.5 kW/cm(2), blood flow was completely occluded within 15 courses. HIFU exposure brought about vacuolar degeneration and destruction of elastic fibers in the tunica media of the artery.

CONCLUSIONS

HIFU can be used to occlude umbilical artery blood flow in fetal rabbits.

Measurement of mRNA of trophoblast-specific genes in cellular and plasma components of maternal blood

BACKGROUND

Placental mRNA in maternal plasma is suitable for quantitative analysis regardless of fetal gender and genetic polymorphism status.

METHODS

We obtained 155 blood samples from pregnant women to compare human placental lactogen (hPL) and beta-subunit of human chorionic gonadotropin (beta hCG) mRNA and protein levels between the cellular and plasma components of maternal blood. To assess clearance of hPL mRNA expression, we obtained blood samples from nine women immediately before and after delivery by caesarean section. mRNA was extracted from the cellular and plasma components of all samples, and hPL and beta hCG mRNA expression was analysed by reverse transcription-PCR assay.

RESULTS

The concentration of beta hCG mRNA in the cellular component positively correlated with the plasma concentration of beta hCG protein and beta hCG mRNA (p = 0.001 for both). The concentration of hPL protein in the plasma correlated with the hPL mRNA concentration of the cellular component (p<0.05). For both hPL and beta hCG, the mRNA concentration of the cellular component was greater than that of the plasma component (22.9-fold higher for hPL and 4.3-fold higher for beta hCG). The half life of hPL mRNA clearance was significantly longer for the cellular fraction (mean half life = 203.8 min, range 150-3465 min) than for the plasma fraction (mean half life = 32.2 min, range 15-385 min) (p = 0.008).

CONCLUSION

The present findings indicate that the concentration of hPL and beta hCG mRNA is significantly higher in the cellular component of maternal blood samples than in the plasma component. Cellular mRNA in maternal blood is useful for non-invasive evaluation of placental function.

Cord insertion into the lower third of the uterus in the first trimester is associated with placental and umbilical cord abnormalities

OBJECTIVES

To assess the feasibility of detecting the cord insertion site during the late first trimester, and to investigate the possible association between perinatal complications and a cord insertion in the lower third of the uterus in the first trimester.

METHODS

This was a prospective cohort study in which the positional relationship between the uterus and the cord insertion site was examined using gray-scale transvaginal sonography at 9-11 weeks of gestation. The distance between the internal os and the fundus was divided equally into three parts. Cord insertions located in the upper or middle thirds were defined as normal (controls), and those located in the lower third were defined as cases, regardless of their relationship to the chorion villosum. Third-trimester sonography and pathological examination of the placenta and cord at delivery were performed to check for placental/cord abnormalities. The univariate association between the location of the cord insertion in the first trimester and placental and umbilical cord abnormalities and perinatal complications was assessed.

RESULTS

The cord insertion site was identified in 318/340 (93.5%) cases at 9-11 weeks of gestation and it was in the lower third of the uterus in 35 (11.0%) cases. Of these 35, the cord insertion was found at delivery to be low in nine cases (26%) and the placenta was low-lying at delivery in eight (23%). None of the 283 cases with a normal cord insertion in the first trimester was found to have a low-lying placenta at delivery (P < 0.0001). Ten (29%) of the cases with a low cord insertion and four (1.4%) with a normal cord insertion in the first trimester had a velamentous or marginal cord insertion at delivery (P < 0.0001). At delivery, five (14%) of the low cord insertion cases and four (1.4%) of the normal cord insertion cases (P < 0.0001) had some form of placental malformation, including accessory placenta and infarction of the placenta. An emergency Cesarean section was performed in four (11%) and six (2.1%) of the low and normal cord insertion cases, respectively (P = 0.003).

CONCLUSION

Developmental abnormalities of the placenta and umbilical cord occur frequently in cases in which the cord insertion is in the lower third of the uterus in the first trimester. We suggest that screening for the cord insertion site at 9-11 weeks of gestation may have clinical significance for predicting abnormalities of the cord and the placenta at delivery.

Velamentous cord insertion into the lower third of the uterus is associated with intrapartum fetal heart rate abnormalities

OBJECTIVES

To evaluate the accuracy of sonographic identification of the site of umbilical cord insertion (CI) at 18-20 weeks of gestation, to compare the sensitivities for detection of a velamentous cord insertion (VCI) secondary to a CI into the anterior, posterior or fundal wall, and to compare the intrapartum complications secondary to VCI into the upper, middle or lower third of the uterus.

METHODS

As part of the routine ultrasound scan at 18-20 weeks' gestation we evaluated abnormal CI (VCI and marginal CI) and the location of the CI in the uterus in 3446 pregnancies. In cases of abnormal CI, the location of the CI was further classified as being in the upper, middle or lower third of the uterus. After delivery, the placenta and the umbilical cord were examined and intrapartum complications were compared with the location of the CI.

RESULTS

The values for antenatal detection of VCI were: sensitivity, 25 of 40 (62.5%); positive predictive value, 25 of 25 (100%); and negative predictive value, 3406 of 3421 (99.6%). The sensitivity for cases in which the CI was located on the anterior wall was 12 of 13 (92.3%); when it was located on the posterior wall, the sensitivity was 11 of 22 (50.0%); and when it was fundal the sensitivity was 2 of 5 (40.0%). Variable decelerations were frequently observed with a VCI. In lower VCI cases, non-reassuring fetal heart rate patterns and emergency Cesarean sections occurred with a higher frequency than in cases with upper or middle VCI (P < 0.01). After delivery, the length of the aberrant vessels in cases of VCI by pathologic examination was 3.9 +/- 3.3 cm in the upper third, 4.7 +/- 4.6 cm in the middle third, and 10.6 +/- 6.8 cm in the lower third; thus, the aberrant vessel length was significantly greater when the CI was in the lower third of the uterus (P = 0.024).

CONCLUSION

We have demonstrated that VCI with a lower CI site and with longer aberrant vessels is associated with various intrapartum complications. This finding has the potential for improving perinatal outcome.

Malignant transformation of endometriosis and genetic alterations of K-ras and microsatellite instability

OBJECTIVES

To clarify the role of specific genetic alterations in the multi-step process of malignant transformation of endometriosis.

METHODS

In cases of ovarian endometrioid carcinoma, we separated regions of normal endometriosis, atypical endometriosis and ovarian endometrioid carcinoma by laser microdissection, and examined K-ras mutation and microsatellite instability in each separated tissue sample.

RESULTS

We detected K-ras mutation and microsatellite instability in endometrioid carcinoma tissue, but not in normal or atypical endometriosis bordering the cancerous region.

CONCLUSIONS

The present findings suggest that K-ras mutation and microsatellite instability are associated with malignant transformation from atypical endometriosis to ovarian endometrioid carcinoma.

Velamentous cord insertion and atypical variable decelerations with no accelerations

OBJECTIVES

To examine intrapartum fetal heart rate (FHR) patterns in the presence of velamentous cord insertion (VCI).

METHODS

The site of cord insertion was determined in 1460 women on antenatal ultrasonographic and postnatal examinations. Each of 24 women with pregnancies complicated with VCI was matched at the onset of labor with 10 women who had a normal pregnancy, and FHR patterns were analyzed for both cases and controls.

RESULTS

Compared with controls, cases of variable decelerations with no accelerations (VDNA) during the first and second stages of labor were more frequent in women with VCI (first stage: 25% vs. 5.1%, second stage: 65.0% vs. 21.7%, P < 0.001). The adjusted odds ratio associated with VDNA occurrence in women with VCI was 3.83 (95% confidence interval [CI]: 1.51-9.72, P = 0.005). The mean odds ratio associated with length of aberrant vessels in women with VCI plus VDNA was 1.38 (95% CI: 1.04-1.83, P = 0.026).

CONCLUSION

Pregnancies complicated with VCI are associated with a higher rate of VDNA.

Detection of p53 mutations in the plasma DNA of patients with ovarian cancer

Mutation of p53 is one of the most common genetic abnormalities detected in up to 81% of cases of ovarian cancer. To evaluate the use of plasma DNA analysis as a method for somatic mutation screening, we measured the presence of p53 mutations in DNA isolated from plasma and cancer tissue from patients with ovarian cancer. We analyzed the plasma DNA for the presence of p53 mutations (exons 5-8). Of 27 cases of ovarian cancer, 12 cases (44%) had mutations of p53 in cancer tissue. In two of the 12 cases (16.7%), identical mutations were detected in DNA of their preoperative plasma. In our follow-up of the two patients with p53 mutations in their plasma, mutant DNA was undetectable in their plasma after surgery. In one case, the p53 mutation re-surfaced in their plasma 16 months after surgery, and the patient died 2 months later. We have shown that tumor-derived DNA can be detected in the plasma of some patients with ovarian cancer, particularly in those with more advanced stage.

Prenatal screening of single-gene disorders from maternal blood

Fetal cells and cell-free fetal DNA can be found circulating in maternal blood. Fetal cells recovered from maternal blood provide the only source of pure fetal DNA for noninvasive prenatal DNA diagnosis. Fetal nucleated erythrocytes (NRBCs) are considered the most suitable maternally-circulating fetal cells for this purpose, because they are not commonly found in the peripheral blood of healthy adults and are most abundant in the fetus during early gestation. Because fetal cells in maternal blood are extremely rare, a definitive separation method has not yet been established. Fetal NRBCs can be enriched from maternal blood via fluorescence- or magnetic-activated cell sorting, density gradients, immuno-magnetic beads or micromanipulation. Fetal cells are identified by Giemsa staining, hybridization with Y-chromosome specific probes, PCR-detection of a specific paternal allele, or immunostaining for fetal cell antigens. Amplification of fetal DNA sequences by primer extension preamplification and PCR has allowed prenatal screening for Duchenne muscular dystrophy and the fetal RhD blood type. Sequence-specific hybridization has been used to detect sickle cell anemia and beta-thalassemia prenatally in heterozygous carriers of these disorders. The use of cell-free fetal DNA in maternal plasma for the diagnosis of single-gene disorders is limited to disorders caused by a paternally inherited gene or a mutation that can be distinguished from the maternally inherited counterpart. At present, fetal gender can be determined from maternal plasma. When a pregnant woman is a heterzygous carrier of an X-linked disorder, the determination of fetal gender is clinically very informative for first-step screening to avoid invasive amniocentesis. The non-invasive prenatal diagnosis of genetic disorders should be applied to pregnant women with a definite risk for a specific single-gene disorder.

Steroid sulfatase expression in ovarian clear cell adenocarcinoma: immunohistochemical study

OBJECTIVE

Steroid sulfatase (STS) is an important enzyme that converts biological inactive steroid sulfate to active free steroid. As estrogen is thought to play an important role in cell proliferation in gynecological cancer, the existence of STS may have particular significance in the prognosis of ovarian cancer. In the present study, we determined the STS expression of ovarian clear cell adenocarcinoma (OCCA), which has the poorest prognosis among various ovarian cancers, immunohistochemically to clarify the biological nature of OCCA and also to determine whether STS expression is one of the prognostic factors in OCCA.

METHODS

Forty-five archival, formalin-fixed, paraffin-embedded tissues from patients with OCCA and other epithelial ovarian cancers who were first operated on from 1987 to 1998 were subjected to analysis. Twenty-eight of forty-five (60.9%) OCCA cases coexisted with endometriosis. They were subclassified into papillary, solid, and tubulocystic types with respect to architectural pattern. Immunohistochemical staining of STS was performed using anti-human STS polyclonal rabbit antibody that had been immunized with purified STS from human placenta.

RESULTS

STS was immunohistochemically stained positively in 70% (32/45) of OCCA, 33.3% of serous adenocarcinoma (6/18), and 50.0% of mucinous adenocarcinoma (4/8) specimens and was localized in the cytoplasm of neoplastic epithelial cells. No significant relationship was found between STS staining and FIGO staging. However, patients diagnosed as papillary type had a significantly lower survival rate and showed significantly more positive staining of STS (P < 0.05) than those with solid type. Stage, STS expression, and architectural type yielded a significant association with survival rate.

CONCLUSION

It was proven that STS is present in the cytoplasm of patients with OCCA by an immunohistochemical method. OCCA patients with papillary tumor with positive STS expression are considered to have a poor prognosis.

Apoptosis in fetal nucleated erythrocytes circulating in maternal blood

The purpose of this study was to determine if apoptosis occurs in fetal cells that have crossed into the maternal circulation, which would potentially explain the difference between the number of intact fetal cells and the amount of fetal DNA detectable in maternal plasma. We flow-sorted fetal nucleated erythrocytes (FNRBCs) using antibody to the gamma chain of fetal haemoglobin and confirmed them to be fetal in origin by FISH analysis using chromosome-specific probes. Fetal cells were then analysed microscopically for the presence of terminal UdTP nuclear end labelling (TUNEL) staining. Apoptotic change was observed in 42.7% of fetal NRBCs (106/246) and 3.5% of maternal cells (29/818). Results of this study indicate that a significant number of fetal cells in maternal blood are undergoing apoptosis at the time of sampling. Apoptosis may be one mechanism by which fetal cells are cleared by the maternal circulation.

Prenatal DNA diagnosis of a single-gene disorder from maternal plasma

Achondroplasia is a short-limb disorder caused by a point mutation in a single gene. To diagnose such a disorder prenatally requires the use of invasive procedures such as amniocentesis. However, using PCR and restriction fragment length polymorphism analysis, we were able to detect the mutation in the plasma of a woman carrying a fetus suspected of having achondroplasia. The detection of a fetus-derived mutant gene from maternal plasma may therefore permit non-invasive prenatal diagnosis of single-gene disorders.

Female fetal cells in maternal blood: use of DNA polymorphisms to prove origin

The nucleated erythrocyte (NRBC) is one of the target fetal cell types for noninvasive genetic diagnosis using maternal peripheral blood. However, it is now known that pregnancy can stimulate the production of maternal NRBCs. When isolating female gamma-positive NRBCs, fluorescence in situ hybridization (FISH) analysis may show two X chromosome signals per nucleus, and therefore it cannot be conclusively determined whether the isolated cells are fetal or maternal in origin. The purpose of this study was to develop a means of verifying that a female cell is fetal on the basis of polymorphic short tandem repeat markers. Peripheral blood samples were obtained from women who had just undergone termination of pregnancy. Nucleated candidate fetal cells were isolated by flow-sorting using antibody to the gamma-chain of fetal hemoglobin and Hoechst 33342. FISH analysis was performed using X and Y chromosome specific probes. Female gamma-positive cells and leukocytes were micromanipulated separately and subjected to fluorescent polymerase chain reaction amplification of chromosome 21 and/or 18 STR markers (D21S11, D21S1411, D21S1412, and D18S535). In all ten cases analyzed, the gamma-positive female candidate fetal cells were determined to be fetal in origin by the presence of shared and nonshared DNA polymorphisms when compared with maternal leukocytes. These results show that genetic analysis can be performed on all fetal NRBCs, including female fetal cells that cannot be distinguished from maternal cells based on FISH analysis alone.

Comparison of fetal cell recovery from maternal blood using a high density gradient for the initial separation step: 1.090 versus 1.119 g/ml

The purpose of this study was to improve recovery of fetal nucleated erythrocytes (NRBCs) from maternal blood for non-invasive prenatal diagnosis. Peripheral blood samples were obtained from 27 women who had just undergone pregnancy termination at 6 to 23 weeks. Samples were split and mononuclear cells were isolated using Histopaque gradient at densities of 1.090 g/ml and 1.119 g/ml. CD45 depletion using magnetic activated cell-sorting, followed by flow-sorting with antibody to gamma-globin and fluorescence in situ hybridization (FISH) analysis, were used to evaluate the number of fetal NRBCs recovered. In samples separated with the 1.119 g/ml density gradient, the yield of true anti-gamma haemoglobin positive cells (median, 14. 9; range, 0-717.5) was significantly higher than that with the 1.090 g/ml density gradient (median, 4.9; range, 0-532.5). After FISH analysis, in the 14 samples in which the fetal karyotype differed from the mother, the median number of fetal NRBCs separated by the 1. 119 g/ml density gradient was 22.9 (2-717.5), which was significantly higher than that by the 1.090 g/ml gradient (median, 11.5; range, 0-532.5, p=0.022). Increased density of the gradient used for the initial enrichment of fetal cells results in improved fetal cell recovery in fresh post-termination blood samples, which may permit better non-invasive detection of fetal cells in maternal blood.

Detection of male and female fetal DNA in maternal plasma by multiplex fluorescent polymerase chain reaction amplification of short tandem repeats

The purpose of this study was to develop a fluorescent polymerase chain reaction (PCR) assay for the detection of circulating fetal DNA in maternal plasma. Maternal DNA extracted from plasma samples of pregnant women at term and newborn DNA isolated from cord blood were used to genotype 12 mother/child pairs at nine different polymorphic short tandem repeat loci. Multiplex fluorescent PCR was used to detect fetus-specific alleles in the corresponding maternal plasma samples. Fetus-specific alleles were found in all maternal plasma samples studied. Using these polymorphic repeat sequences, every mother/child pair was informative in at least four of nine loci. Paternally inherited fetal alleles were detected in 84% of informative short tandem repeats. This approach may have implications for non-invasive prenatal diagnosis. Compared with other fetal DNA detection systems that use fetus-derived Y sequences to detect only male fetal DNA in maternal plasma, our proposed technique can be applied to both female and male fetuses.

Fetal cell recycling: diagnosis of gender and RhD genotype in the same fetal cell retrieved from maternal blood

OBJECTIVE

Our aim was to develop a new technique, which we have termed fetal cell recycling, that combines the 2 powerful methods of fluorescence in situ hybridization and polymerase chain reaction to maximize the genetic information available from a small number of fetal nucleated erythrocytes obtained noninvasively from the blood of pregnant women.

STUDY DESIGN

Blood samples were obtained from 4 Rh-negative women after elective termination of pregnancy at 7 to 17 weeks' gestation. Fetal nucleated erythrocytes were separated by flow sorting with antibody to the gamma chain of fetal hemoglobin. Fluorescence in situ hybridization with chromosome-specific probes was used to diagnose fetal gender. After fluorescence in situ hybridization analysis the fetal nucleated erythrocytes were recycled by a micromanipulation technique and deoxyribonucleic acid diagnosis was performed with polymerase chain reaction amplification of the RhD gene.

RESULTS

Among the 4 case patients we detected a total of 101 fetal nucleated erythrocytes. All targeted cells were successfully retrieved with a micromanipulator. In each case we successfully performed both fluorescence in situ hybridization and polymerase chain reaction analysis. The predicted fetal gender and Rh status corresponded to the results obtained from fetal tissue.

CONCLUSIONS

Fetal cell recycling combines the powers of highly sensitive molecular methods to maximize the genetic information available from a single fetal cell. This technique will permit noninvasive diagnosis of recessively inherited single-gene disorders.

Latent class analysis applied to patterns of fetal sonographic abnormalities: definition of phenotypes associated with aneuploidy

The aim of the present study was to generate different latent variables that classify the major chromosome aneuploidies using frequency and patterns of fetal sonographic abnormalities in a large database. A total of 1867 fetuses with sonographic abnormalities recorded in a database at New England Medical Center from January 1995 to March 1998 were available for the statistical analysis. Included within this group were 61 aneuploid fetuses, including 11 with 45,X, 30 with trisomy 21, 14 with trisomy 18 and 6 with trisomy 13, 40 structural malformations and/or sonographic markers were detected in these 61 aneuploid fetuses. The ability of malformations and sonographic markers to generate different groups of phenotypes was evaluated by means of latent class analysis, using the 61 affected cases. Four different classes were generated with the hypothetical assumption that each of them could satisfactorily identify a respective fetal aneuploidy represented in the study group. Among 40 fetal malformations and/or sonographic markers, the most important findings in generating specific karyotypic groups were cystic hygroma (class 1), duodenal atresia (class 2), holoprosencephaly (class 3) and omphalocele (class 4), respectively. Accuracy of the classification was 72 per cent for Turner syndrome (class 1), 74 per cent for Down syndrome (classes 1 and 2), 88 per cent for trisomy 13 (class 3) and 93 per cent for trisomy 18. The frequency of associated malformations detected sonographically can help to define a phenotype that is likely to be representative of a specific aneuploidy. Before the definitive karyotype is available or, in cases in which patients refuse an invasive prenatal diagnostic procedure, this may improve antenatal clinical management.

Improvement of fetal cell recovery from maternal blood: suitable density gradient for FACS separation

OBJECTIVE

To improve the recovery of fetal nucleated erythrocytes (NRBCs) from maternal blood for noninvasive prenatal genetic diagnosis.

METHODS

Blood samples were obtained from 10 women at 8-22 weeks of gestation. Samples were split and mononuclear cells were isolated using 1.083 and 1.090 g/ml of Percoll solution. Flow sorting with antibody to fetal hemoglobin and fluorescence in situ hybridization (FISH) analysis were used to evaluate the number of fetal cells recovered.

RESULTS

In samples separated with the 1.090 density gradient, the yield of true gamma-hemoglobin-positive cells (median 21.0, range 2.2-303.8) was 1.9 times higher than that in the 1.083 density (median 11.1, range 1.1-87.5), although it took 2. 1-fold longer time to flow sort the gamma-hemoglobin-positive cells. In 7 out of 10 cases, the number of gamma-hemoglobin-positive cells recovered from the 1.090 density gradient was 3 times or greater than that from 1.083 gradient. After FISH analysis, we detected a median of 13.3 (range 2.2-98.8) fetal NRBCs per 10-ml maternal blood in the 1.090 density gradient, whereas a median of 11.0 fetal NRBCs were detected in the 1.083 gradient (range 1.1-35.0). The number of fetal NRBCs in the 1.090 density was significantly higher than that in the 1.083.

CONCLUSION

Increased Percoll density results in improved fetal cell recovery in fresh posttermination maternal samples. The increased yield of fetal cells using this gradient may permit better noninvasive detection of fetal chromosome as well as DNA abnormalities in maternal blood.

Prenatal diagnosis of ornithine transcarbamylase deficiency by using a single nucleated erythrocyte from maternal blood

We have developed a method that allows the prenatal DNA diagnosis of ornithine transcarbamylase (OTC) deficiency by using a single fetal nucleated erythrocyte (NRBC) isolated from maternal blood. OTC gene analysis of a male patient (TF) with early onset OTC deficiency was performed by single-strand conformation polymorphism (PCR-SSCP) and DNA sequencing. To investigate the possible prenatal diagnosis of OTC deficiency, maternal blood was obtained at 13 weeks of gestation of a subsequent pregnancy, from the mother of patient TF. NRBCs in the maternal blood were separated by using the density gradient method and then collected with a micromanipulator. The entire genome of a single NRBC was amplified by primer extension preamplification (PEP). The human leukocyte antigen (HLA)-DQ alpha genotype and sex were determined from small aliquots of the PEP product. The HLA-DQ alpha genotype of each of the parents of the male patient was also determined. Once a single NRBC had been identified as being of fetal origin, the OTC gene was analyzed by using the restriction fragment length polymorphism (RFLP) method. DNA analysis revealed a point mutation in exon 9 of the OTC gene in the OTC-deficient patient (TF). All NRBCs retrieved from maternal blood were successfully identified as being of fetal origin by HLA-DQ alpha genotyping and sex determination. RFLP analysis demonstrated that the fetal OTC gene was normal. This is the first study to successfully diagnose OTC deficiency prenatally, by using a single fetal NRBC from the maternal circulation. Such prenatal DNA diagnosis is non-invasive and can be applied to other genetic diseases, including autosomal and X-linked diseases.

Analysis of HLA-DQ alpha sequences for prenatal diagnosis in single fetal cells from maternal blood

We have extended a previously developed method that allows prenatal DNA diagnosis of female fetuses through the isolation of single nucleated erythrocytes from maternal blood by developing a method that can distinguish between maternal and fetal nucleated erythrocytes. Nucleated erythrocytes were separated by a density-gradient method and then collected by micromanipulation. Sex was determined after primer extension preamplification (PEP) of the entire genome of a single cell, and human leukocyte antigen (HLA)-DQ alpha type was determined after further amplification of this gene. The HLA-DQ alpha genotype of fetal erythrocytes in maternal blood samples and their corresponding paternal and maternal lymphocytes were successfully determined in all cases. The accuracy of the method was determined by using single nucleated erythrocytes from umbilical cord blood from five normal deliveries. This is the first demonstration that the fetal HLA-DQ alpha gene sequences can be identified in a small aliquot of a single nucleated erythrocyte in maternal blood. We believe that this method ushers in a new era in which the reliability and accuracy of noninvasive prenatal DNA diagnosis from maternal blood is markedly improved.

[Prenatal diagnosis of Duchenne muscular dystrophy using single fetal cell in maternal blood]

We developed a method that allows prenatal diagnosis of Duchenne muscular dystrophy using a single nucleated erythrocyte (NRBC) isolated from maternal blood. Maternal blood was obtained at 8 to 20 weeks of gestation. NRBCs were separated with Percoll using a discontinuous density gradient method and then collected by micromanipulator under microscopic observation. The entire genome of a single cell amplified by primer extension preamplification (PEP). Sex was determined from a small aliquot of the PEP reaction. After an NRBC was determined to be male and confirmed to be of fetal origin, dystrophin exons 4, 8, 12, 45, 48, 50, and 51 were determined from the same PEP reaction. This diagnostic method using maternal blood is safer than amniocentesis or cordocentesis and can be applied to other X-linked disease.

3Beta-hydroxysteroid dehydrogenase activity in human osteoblast-like cells

This paper describes for the first time the presence of 3beta-hydroxysteroid dehydrogenase (3beta-HSD) activity in osteoblast-like cells and investigates its characteristics. 3beta-HSD activity was detected by the formation of androstenedione from [3H]dehydroepiandrosterone (DHEA) in whole cell assays of human osteoblast-like cells, HOS and MG-63. The radiolabeled product, androstenedione, was purified by thin-layer chromatography and identified by recrystallization on admixture with authentic androstenedione to show constant specific activities. The apparent Michaelis constant (Km) for DHEA in HOS was found to be 9.9 microM and that in MG-63 was 80.4 microM. The expression of the 3beta-HSD messenger ribonucleic acid in HOS and MG-63 was demonstrated through a reverse transcription-polymerase chain reaction. The PCR products were confirmed by Southern blot analysis. The existence of 3beta-HSD in osteoblast-like cells indicates that these cells convert delta5 androgens into more biologically active delta4 3-keto steroids. These results, together with the demonstration of other steroid converting enzyme systems, suggest that the osteoblast cells play an important role in facilitating hormonal action in bone tissue.

A study of gamma-aminobutyric acid (GABA) in amniotic fluid

OBJECTIVE

The purpose of the study was to evaluate the role of gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter, in amniotic fluid (AF) during fetal distress, because it has been reported that several neurotransmitters, e.g. norepinephrine, are affected by GABA.

METHODS

AF was obtained during elective cesarean section (CS, n = 11) and cesarean section due to fetal distress without labor pain (FD, n = 7). Maternal and umbilical-cord blood, as well as the first urine of the neonates, also were collected. GABA, norepinephrine (NE), and epinephrine (EP) concentrations were measured using HPLC.

RESULTS

The GABA concentration was higher in the AF than in either maternal or fetal circulation, or in the first urine of neonates. The GABA concentrations in the AF and in the first urine of neonates were significantly higher in the FD group than in the CS group (p < 0.05). Furthermore, significant positive correlations were observed between the NE and GABA concentrations and between the EP and GABA concentrations in the AF. GABA was produced in a time-dependent manner in cultured amnion cells.

CONCLUSION

The highest concentration of GABA was found in the AF. The GABA in the AF appeared to be derived from both the amniotic membrane and the fetal urine. The increase in the GABA concentration in cases of fetal distress might be partially derived from the fetus via fetal urine. The positive correlations between the concentrations of GABA and those of NE and EP in the AF, suggest that GABA, NE, and EP might play important roles during fetal distress.

Steroid sulfatase activity in osteoblast cells

We have demonstrated steroid sulfatase activity in osteoblast cells and characteristics of the enzyme were also investigated. Cell free homogenate of rat osteoblast cell line, UMR106-01 and human osteoblast cell lines, MG-63, HOS were incubated with [3H] dehydroepiandrosterone-sulfate (DHEA-sulfate) or [3H] estrone-sulfate (E1-sulfate). The formation of DHEA or E1 from the corresponding substrate was identified by crystallization to constant specific activity. Michaelis constant (K(m)) for DHEA-sulfate was estimated as 2.1 x 10(-8)M in UMR106-01, 7.4 x 10(-7)M in MG-63, 5.8 x 10(-7)M in HOS and that for E1-sulfate was 4.1 x 10(-7)M, 3.0 x 10(-7)M, 9.8 x 10(-7)M, respectively. The expression of steroid sulfatase messenger ribonucleic acid in human osteoblast cells, HOS and MG-63 was first demonstrated by reverse transcription-polymerase chain reaction. The existence of steroid sulfatase in human and rat osteoblast cells suggests that osteoblast cells have the capacity to convert circulating sulfo-conjugated steroids to more active androgens and estrogens. This may indicate an important role of bone in facilitating hormonal action.

A study of monoamine oxidase activity in fetal membranes

OBJECTIVE

To study the role of decidual monoamine oxidase (MAO)-A and -B activities before delivery, the relationship between MAO activity in fetal membranes and catecholamine (CA) concentration in amniotic fluid (AF) was determined.

METHODS

Fetal membranes and AF were obtained at the time of elective Cesarean section (CS group, n = 11) and Cesarean section due to fetal distress without labor pains (FD group, n = 5). MAO-A and -B activities were radiometrically measured using 14C-5-hydroxytriptamine for MAO-A substrate and 14C-benzylamine for MAO-B substrate. CA concentrations in AF were measured by high performance liquid chromatograph with an electro-chemical detector.

RESULTS

Both MAO-A and -B activities in decidua obtained from CS were significantly lower than those obtained from FD. Both norepinephrine (NE) and epinephrine (EP) concentrations were significantly lower in the CS group than the FD group. A significant positive correlation between decidual MAO-A activity and NE concentration in AF was observed. No significant correlation was observed between MAO-B activity and the concentration of NE in AF. There was no correlation between EP concentrations and MAO activities.

CONCLUSION

These results suggest that CA concentration in AF may be related to the activity of MAO in fetal membranes, determined by certain physiological processes during pregnancy. It has been suggested that metabolism of monoamines in fetal membranes also plays an important role in reducing monoamine influx into maternal myometrium from the AF.

Prenatal diagnosis of Duchenne muscular dystrophy using a single fetal nucleated erythrocyte in maternal blood

We developed a method that allows prenatal diagnosis of Duchenne muscular dystrophy using a single nucleated erythrocyte (NRBC) isolated from maternal blood. Maternal blood was obtained at 8 to 20 weeks of gestation. NRBCs were separated with Percoll using a discontinuous density gradient method and then collected by micromanipulator under microscopic observation. The entire genome of a single cell was amplified by primer extension preamplification (PEP). Sex was determined from a small aliquot of the PEP reaction. After an NRBC was determined to be male and confirmed to be of fetal origin, dystrophin exons 4, 8, 12, 45, 48, 50, and 51 were determined from the same PEP reaction. This diagnostic method using maternal blood is safer than amniocentesis or cordocentesis and can be applied to other X-linked diseases.

Prenatal diagnosis of the fetal RhD blood type using a single fetal nucleated erythrocyte from maternal blood

OBJECTIVE

To develop a method that allows prenatal diagnosis of the fetal RhD blood type from maternal blood.

METHODS

Maternal blood was obtained at 8-31 weeks' gestation, and nucleated erythrocytes were separated with Percoll using a discontinuous density gradient method, then collected individually by micromanipulation under microscopic observation. After whole genome amplification with primer extension pre-amplification, exon 7 of the RhD and RhCE as well as the ZFX/ZFY loci were further amplified by a nested polymerase chain reaction (PCR).

RESULTS

Nucleated erythrocytes were detected in nine of ten maternal blood samples, and sex was determined in 13 of 21 nucleated erythrocytes. RhD genotype could be diagnosed in 12 of the 13 nucleated erythrocytes in which sex could be determined. The results of RhD blood type and sex in nucleated erythrocytes obtained from maternal blood were identical with those of newborns. Fetal RhD blood type could be determined in six of ten maternal blood samples.

CONCLUSION

A new method for noninvasive prenatal diagnosis of the fetal RhD blood type using a single nucleated erythrocyte isolated from maternal blood was demonstrated. This diagnostic method offers extremely useful information for the management of Rh-negative pregnant women. Furthermore, this method of prenatal diagnosis can be applied to other genetic disorders and is expected to become the preferred method of noninvasive prenatal diagnosis of DNA.

[Relationship between catecholamine levels in amniotic fluid and fetal blood flow in fetal distress]

Eighteen cases of complicated pregnancy with fetal distress and/or pregnancy toxemia who underwent Cesarean section (CS) before onset of labor were studied. The resistance indexes (RI) of the umbilical artery (UA) and fetal middle cerebral artery (MCA) were measured by Doppler echography prior to CS. UA blood and amniotic fluid (AF) were obtained during CS and the pH value for the UA and the concentrations of norepinephrine (NE) and epinephrine (E) in AF were measured. A significant correlation between the pH value, MCA-RI/UA-RI ratio and the levels of NE and E in amniotic fluid was obtained. NE and E concentrations in AF obtained from the patients with fetal distress before the onset of labor were 1.92 +/- 0.54 and 1.48 +/- 0.28ng/ml and these concentrations were significantly higher then those from elective CS. The deviations (delta SD) of RI from the normal mean for corresponding gestational age in fetal distress were -4.21 +/- 0.94 in MCA and 1.31 +/- 0.48 in UA. A negative correlation between the pH value and delta SD (UA) was observed but the pH value correlated positively with delta SD (MCA). Furthermore, the MCA-RI/UA-RI ratio showed a significant negative correlation with the NE and E levels in AF. These results suggest that fetal catecholamine affects fetal blood flow in fetal distress.

Effect of labor and prostaglandins on phenylethanolamine N-methyltransferase in human fetal membranes

Biochemical investigations have shown the presence of the enzyme phenylethanolamine N-methyltransferase (PNMT), which converts norepinephrine (NE) to epinephrine (E) in human pregnant tissues, e.g. myometrium and fetal membranes. The enzymatic activity of PNMT in myometrium is known to decrease during labor. In the present study, PNMT activity in chorio-decidua was measured and the effect of labor and prostaglandins (PG) on PNMT activity was determined. A cytosol fraction of chorio-decidua was incubated with [14C]-S-adenosyl-L-methionine and normetanephrine for 60 min to measure PNMT activity. Fetal membranes were obtained at elective Cesarean section and normal vaginal delivery from full term pregnant women, and the activity of PNMT in chorio-decidua was compared. Significantly lower activity in chorio-decidua obtained from normal vaginal delivery than that from elective Cesarean section was observed. The concentration of 13, 14-dihydro-15-keto-prostaglandin F2 alpha (DHK-PGF2 alpha) in amniotic fluid obtained at normal vaginal delivery were measured by RIA, and the relationship of the DHK-PGF2 alpha level to PNMT activity was studied. There was a significantly negative correlation between the concentration of DHK-PGF2 alpha in amniotic fluid and PNMT activity in chorio-decidua. When various concentrations of PGF2 alpha were pre-incubated with mined chorio-decidua for 2 h, PNMT activity was decreased in a dose dependent manner. These results indicated that PGF2 alpha might affect the bioconversion of NE to E in fetal membranes. The presence of this enzyme in fetal membranes may play an important role in regulating the concentration of catecholamines during pregnancy and parturition.

Isolation and characterization of a protein from hagfish serum that is homologous to the third component of the mammalian complement system

The 192-kDa protein HX, a major component of serum that specifically binds to zymosan particles, was prepared from the plasma of the hagfish (Eptatretus burgeri) by ion-exchange chromatography and gel filtration. HX, present at a concentration of 0.8 mg/ml in the original plasma, was composed of two distinct subunits of 115 kDa and 77 kDa, respectively, which were linked by disulfide bonds. The protein had the same electrophoretic mobility as beta-globulin. Digestion by trypsin resulted in a specific cleavage of the 115-kDa subunit and a change in its immunoelectrophoretic mobility in the anodal direction, leaving the 77-kDa subunit intact. Treatment with SDS and urea resulted in the splitting of the 115-kDa subunits into 68-kDa and 45-kDa components, but this splitting was inhibited by pretreatment with methylamine, suggesting the presence of a thiol ester bond in the 115-kDa subunit. The amino acid composition of HX revealed a striking resemblance to that of human C3. We conclude, therefore, that the 192-kDa protein isolated in this study is analogous to C3, which plays a key role in the mammalian C system.