Tocolysis with atosiban: experience in the management of premature labor before 24 weeks of pregnancy.

OBJECTIVE: Atosiban has been shown to be an effective tocolytic agent with a low rate of side effects during 24 to 33 weeks of gestation. Atosiban acts through selective, competitive inhibition of both oxytocin and vasopressin, so that there are reasons to assume that a tocolytic effect can also be achieved earlier in the pregnancy. STUDY DESIGN: In this prospective, randomized pilot study, 20 women in the 18th through 24th week of gestation who presented at our hospital with preterm labor were treated with atosiban. In the control group 20 women received saline infusions. All patients received antibiotic therapy. A cervical cerclage was performed when indicated as was correction of the vaginal pH. RESULTS: The tocolytic effect began after 3-10 min (median: 6.5 min). Treatment time until the complete absence of contractions was 3-12 h (median: 7.5 h). Pregnancies were prolonged between 11.1 and 21.7 weeks (median: 15.6 weeks) in the atosiban group vs. 10.5-19.1 weeks in the control group. If well tolerated, atosiban was continued. There were no significant alterations in the routine laboratory parameters, circulation parameters, and fluid balance. CONCLUSION: In summary, atosiban showed itself to be effective for tocolytic treatment for premature labor, even during 18 and 24 weeks of pregnancy, while exhibiting its known, favorable profile of side effects.

Oxytocin receptor gene expression of estrogen-stimulated human myometrium in extracorporeally perfused non-pregnant uteri.

Oxytocin (OT) and the oxytocin receptor (OTR) seem to be less important for uterine contractility-associated disorders of the non-pregnant uterus compared to the pregnant uterus. In the present study, we investigated the mutual dependence of OTR, OT and 17beta-estradiol (E(2)) with regard to the localization of OTR in the non-pregnant uterus. Utilizing our established model for extracorporeal perfusion of the human uterus, we perfused 15 human uteri for 27 h under physiological conditions without oestradiol (group A, n = 5) or with high E(2) stimulation (group B, n = 5) followed by OT stimulation for both groups during the last 3 h of the experiment. Negative controls (n = 5) remained in perfusions for 27 h without any further hormone treatment. Gene expression of the myometrial OTR in both groups was compared using reverse transcriptase triple primer PCR. Stimulation with E(2) and OT led to significantly higher OTR gene expression than stimulation with OT alone. We also showed that concentrations of OTR transcripts increase from the lower uterine segment to the uterine fundus. However, maximum OTR levels of the uterine fundus in group B did not reach concentrations of specimens of third trimester of pregnancy which were used as positive controls. We conclude that our experimental model simulates a situation similiarly to the stimulated non-pregnant uterus in the therapeutic concepts of assisted reproduction. The data presented demonstrate that the dynamics of OTR expression can be modulated by stimulation with E(2) and OT, not only in the pregnant but also in the non-pregnant uterus.

Paraneoplastic neurological syndrome: patient with anti-Yo antibody and breast cancer: a case report.

Presented here is the case of a paraneoplastic cerebral degeneration (PCD) in a female patient with breast cancer and the indication of anti-Yo antibodies in the cerebrospinal fluid (CSF) and serum. The patient's primary indications were dizziness and a severe gait ataxia. The indication of anti-Yo antibodies led to the conclusion of the existence of a paraneoplastic cerebral degeneration. The antibodies in question are anti-Purkinje-cell autoantibodies acting against the antigens common to tumor and Purkinje cells which occur in association with a certain percentage of breast or ovarian cancers. The diagnosis of the primary tumor, that is clinically undetectable with conventional imaging processes, is performed with the aid of positron emission tomography (PET) to detect the presence of axillary lymph node metastases. The micro-invasive mammary carcinoma was able to be localized with the aid of MR mammography and, after MR mammography marking, was removed. The patient subsequently received adjuvant treatment with epirubicine and cyclophosphamide. This treatment failed to influence the paraneoplastic neurological symptoms.

[Fetomaternal macrotransfusion after attempted external version]. / Fetomaternale Makrotransfusion nach Versuch der äusseren Wendung.

BACKGROUND: External cephalic version is an alternative to both vaginal breech delivery and to caesarean section. The objective of this study was to summarize potential complications of external cephalic version. Which means are available for early detection and treatment of these complications? CASE REPORT: A 28-year-old 1/0 with breech presentation was considered for external cephalic version at the 38th week of gestation. As three version attempts failed, the patient was discharged after normal fetal heart tone (FHT) registration and normal ultrasonographic findings on the next day. Caesarean section was planned six days later. On the day of admission, FHT registration revealed a decreased beat-to-beat variability and a sinusoidal baseline. Doppler-flow indices of the A. umbilicalis and A. cerebri media were normal, although middle cerebral artery peak systolic velocity was increased. Rapid caesarean section was performed, and an anemic baby (hemoglobin 3.4 g/dl) was born. After transfusion of 100 ml red blood cells, further development of the newborn was normal. DISCUSSION AND CONCLUSION: Fetomaternal macrotransfusion may be a rare complication of external cephalic version, occurring even several days after the mechanical manipulation. FHT registrations and ultrasonographic doppler flow measurements performed periodically unit birth are necessary to detect such complications early. The Kleihauer-Betke test is the method of choice to diagnose fetomaternal macrotransfusion.

Cholesterol dynamics in the foetal and neonatal brain as reflected by circulatory levels of 24S-hydroxycholesterol.

UNLABELLED: Oxysterols, particularly those hydroxylated in the steroid side-chain, are formed from cholesterol by specific cytochrome P450 enzymes and may facilitate elimination of cholesterol from extrahepatic sources. In humans, the greatest portion of circulating 24S-hydroxycholesterol (24S-OH-Chol) is derived from the brain and the absolute concentration depends on age. In the present study, concentrations of 24S-OH-Chol and for comparison 27-OH-Chol were determined by a highly sensitive isotope dilution method using gas chromatography-mass spectrometry in serum samples from normal preterm and term neonates and those with Rhesus haemolytic disease, taken serially for diagnostic purposes. Serum concentrations of cholesterol, 24S-OH-Chol and 27-OH-Chol were similar in venous versus arterial cord blood of 6 term neonates. Serum concentrations of 24S-OH-Chol and 27-OH-Chol in 12 small for gestational age (SGA) preterm neonates were significantly lower than those in 12 appropriate for gestational age (AGA) preterm neonates (p < 0.001), and also lower than those in 12 SGA (0 < 0.001) and 12 AGA term neonates (p < 0.05). Serum cholesterol was significantly higher in preterm than in term neonates (p < 0.001). 24S-OH-Chol serially determined in 8 infants with Rhesus haemolytic disease increased 5-6-fold during the first 3 mo after birth (from 42 +/- 20 ng ml(-1) to 227 +/- 71 ng ml(-1)). 27-OH-Chol increased simultaneously from 30 +/- 14 ng ml(-1) to 100 +/- 39 ng ml(-1). CONCLUSION: Serum concentrations of 24S-OH-Chol increased 5-6-fold after birth. This could be an indication of normal cholesterol metabolism in the developing neonatal brain.

Cross-linked type I collagen C- and N-telopeptides in women with bone metastases from breast cancer.

This study documents values of biochemical markers of bone remodeling in 106 patients with breast cancer. Based on scintigraphic and radiological findings, patients were divided into 3 groups: 19 patients with bone metastases, 65 patients without bone metastases and normal bone scintigrams, and 22 patients with pathological, non-malignant findings on scintigraphy without proof of bone metastases. Urinary cross-linked type I collagen N-telopeptides (NTx) and serum cross-linked type I collagen C-telopeptides (ICTP) were assessed as markers of bone resorption. Bone alkaline phosphatase (BAP) was assessed as a marker of bone formation. All three markers were significantly higher in patients with bone metastases compared to both patients without skeletal recurrence and those with pathological, non-malignant scintigraphic findings (p < 0.01). There were no statistically significant differences between the latter two groups. The clinical sensitivity for diagnosing bone metastases was 44% for NTx, 65% for ICTP, and 26% for BAP, respectively. The clinical specificitiy for discriminating patients with bone disease from those without were 79%, 91%, and 92% for NTx, ICTP, and BAP, respectively. In conclusion, markers of bone remodeling are increased in patients with breast cancer metastatic to the skeleton. The sensitivity of the markers presented in this paper did not seem to be sufficient enough for early identification of patients with subclinical bone recurrence in a clinical practice setting.

Photoradiation of perfused placental tissue--a suitable in vitro model for photodynamic therapy?

Our aim was to evaluate the isolated placental lobule as a model to study the cytotoxic effects of photodynamic therapy (PDT) in vitro. Ten human placental lobules were dually perfused with a modified medium 199 for a 4-hour period. Photosan III was added to the fetal perfusate at a dose of 5 mg/kg tissue, and laser light (630 nm wavelength) provided by an argon-pumped dye laser was applied at 50 J/cm2 in the experimental group (n=5). Potassium and lactate dehydrogenase (LDH) release into the perfusate as well as the transplacental creatinine passage from PDT-treated placentas and control placentas (n=5) were compared, and light microscopic examinations of the placental tissue were performed after the experiments. Potassium release into the fetal perfusate was higher in the PDT-treated placental lobules (p<0.05), and weight gain during the artificial perfusion suggests the development of edema only in the photoradiated lobules (p<0.01). The release of the bigger molecules of the LDH however was comparable in the two experimental groups, and transplacental creatinine passage was not affected by photoradiation. Light microscopic examinations demonstrated lesions at the cytotrophoblast, the syncytiotrophoblast and the endothelium of the fetal vessels of the photoradiated placentas, although they were not specific and could also be found in the control tissue. We conclude that the isolated placenta may be used to study cytotoxic effects of photoradiation in vitro, but better specifity and sensitivity might be achieved if a. The perfusion time is prolonged to make the difference between the experimental and the control group clearer and b. Electron microscopic investigations are made to demonstrate intracellular lesions of the mitochondria and the endoplasmic reticulum.

Digoxin, flecainide, and amiodarone transfer across the placenta and the effects of an elevated umbilical venous pressure on the transfer rate.

Clinical observations suggest that flecainide might pass the placenta more easily than digoxin, and that its transfer is less disturbed in case of hydrops fetalis than that of digoxin. The purpose of the study was to compare the materno-fetal transplacental transfer of digoxin, flecainide, and amiodarone, another antiarrhythmic agent used in the treatment of fetal tachyarrhythmia, and to assess the effect of an elevated umbilical venous pressure (UVP) on the transfer rate. Isolated lobules of 16 human placentas were dually perfused after spontaneous delivery or caesarean section. The transplacental transfer (area under the curve in the maternal compartment [maternal AUC], area under the curve in the fetal compartment [fetal AUC], kinetic parameters) of digoxin, flecainide, and amiodarone was calculated after these drugs were added to the maternal circuit. In five experiments, the effect of increased UVP on the transplacental transfer rate was assessed by elevating the UVP by 10 cm H2O. Flecainide efflux out of the maternal compartment was significantly greater than that of digoxin (maternal AUC 57.4% +/- 5.1 %/min vs 73.9% +/- 1.5%/min), whereas the flecainide influx into the fetal circulation was smaller (fetal AUC 9.3% +/- 4.1%/min vs 11.5% +/- 2.0%/min). Only in 50% of the experiments were the smallest amounts of amiodarone detectable in the fetal compartment. An elevation of the UVP reduced the influx of digoxin and flecainide into the fetal compartment (fetal AUC) from 11.5% +/- 2.0%/min to 7.4% +/- 1.9%/min and from 9.3% +/- 4.1% to 4.7% +/- 1.4%/min, respectively. Materno-fetal transplacental transfer of digoxin, flecainide, and amiodarone decreases in this sequence. Fetal cardiac insufficiency accompanied by an elevation of the UVP might reduce the transplacental transfer of these drugs, although no significant difference could be found between the reduction of transfer of digoxin and flecainide.

Extracorporeal perfusion of the human uterus as an experimental model in gynaecology and reproductive medicine.

Experimental perfusion of various organs has primarily been used in transplantation medicine to study the physiology, pathophysiology and metabolism of tissues and cells. The purpose of this study was to establish an experimental model for the extracorporeal perfusion of the human uterus with recirculation of a modified, oxygenated Krebs-Henselait solution, in comparison with a non-recirculating perfusion system. With consent of the patients we obtained 25 uteri after standard hysterectomy. We performed an isovolumetric exchange of the perfusion medium at different intervals from 1 to 6 h and examined pH, pO(2), pCO(2), lactate, lactate dehydrogenase and creatine kinase by taking arterial and venous samples every hour for 24 h. We found the perfusions to be adequate when maintaining flow rates at 15-35 ml/min and at pressures ranging from 70 to 130 mmHg. Isovolumetric exchange of the perfusate every 3-4 h was the maximum interval to keep pH, the arterio-venous gradients of pO(2) and pCO(2), and the other biochemical parameters in physiological ranges. Examination by light and electron microscopy showed well-preserved features of myometrial and endometrial tissue. However, a 6 h exchanging interval led to increasing hypoxic and cytolytic parameters during the whole perfusion period. X-ray studies using digital subtraction angiography and perfusion studies with methylene blue demonstrated the homogeneous distribution of the perfusion fluid throughout the entire organ.

[Maternal and fetal digoxin level in fetofetal transfusion syndrome (FFTS)]. / Maternale und fetale Digoxinspiegel bei fetofetalem Transfusionssyndrom (FFTS).

BACKGROUND: Even though invasive intrauterine techniques for the treatment of TTTS such as punction of amniotic fluid and laser coagulation of placental vascular anastomoses are established methods in specialized centers, invasive methods are not always sufficiently successful. In conservative treatment of TTTS oral or intravenous maternal digoxin therapy in order to improve fetal cardiac insufficiency in combination with or after failure of invasive techniques is an useful method. PATIENTS AND METHODS: We investigated 12 TTTS pregnancies and 4 singleton pregnancies, which had been treated by maternal digoxin treatment for TTTS or arrhythmias, respectively. At birth, which was performed by means of caesarian section, venous cord blood samples of the newborns and venous maternal blood samples were collected, centrifugated and stored at minus 20 degrees C. Digoxin determinations were performed by radioimmunoassay. RESULTS: Fetal digoxin levels varied between 0.38 and 1.73 ng/ml, maternal levels ranged from 0.97 to 3.23 ng/ml. The fetomaternal digoxin gradient reached a mean of 0.56 (range 0.35 to 1.09). Donator and acceptor gradients were comparable and increased with birth weight or gestational week, respectively. CONCLUSIONS: In cases of pregnancies with TTTS a relatively high maternal digoxin level is necessary, especially during early gestational weeks, in order to reach therapeutical levels in the fetal circulation. Too low dosages might be responsible for unfavourable results in digoxin treatment of TTTS. Whether the maturation of placental villi during gestation could be the reason for increasing digoxin gradients requires further investigations.

Clinical application of maternal serum cytokine determination in premature rupture of membranes--interleukin-6, an early predictor of neonatal infection?

BACKGROUND: In cases of premature rupture of membranes (PROM), an early detection of fetal infection is necessary in order to weigh infectious complications against prematurity. As routine parameters (leukocytes, C-reactive protein (CRP), fever, and fetal tachycardia) lack satisfactory sensitivity and specificity, this study evaluates whether the determination of interleukin-6 (IL-6), interleukin-8 (IL-8) or soluble interleukin-2 receptor (IL-2R) in maternal serum could supplement or replace routine inflammation parameters. METHODS: In this prospective study results of clinical and laboratory parameters were investigated with respect to neonatal infection in 71 patients with PROM. IL-6, IL-8 and IL-2R were determined by enzyme immunoassays. RESULTS: Best specificity and sensitivity could be demonstrated for CRP and IL-6. Both elevation of CRP and IL-6 correlated significantly (p<0.01 and p<0.001, respectively) with the onset of neonatal infection. At a cutoff of 11 pg/ml, IL-6 reaches a sensitivity of 81% and a specificity of 76%; CRP a specificity of 76% (cutoff 1.2 mg/dl) and a sensitivity of 56%. In 4/16 (25%) cases developing neonatal infection, IL-6 increased earlier than CRP. IL-8 and IL-2R results showed a less significant correlation with fetal outcome. CONCLUSIONS: Determination of IL-6 in maternal serum can significantly contribute to an earlier detection of fetal infection in patients with PROM.

[Bioavailability of 17 beta-estradiol after transdermal administration--dependence on the patch system]. / Bioverfügbarkeit von 17 beta-Oestradiol nach transdermaler Applikation--Abhängigkeit vom Pflastersystem.

The objective of this study was to compare the pharmacokinetics of serum estradiol concentrations after application of two different transdermal estradiol delivery systems. Ten postmenopausal women (E2 < or = 30 pg/ml; follicle-stimulating hormone > or = 30 mIE/ml) were prospectively randomized to a crossover treatment protocol separated by a 7-day wash out period. The absorption of estradiol was measured after application of a patch either containing 4.0 mg of E2 in a reservoir system or 1.8 mg of E2 in a specially designed matrix system. Although the increase of serum estradiol concentrations after application of the patches with the matrix system was slightly delayed, mean E2 levels over the whole observation period of 80 hours were significantly higher than those achieved with the reservoir system (difference of mean values: 5.1 pg/ml; p < 0.05). This observation was most striking at the end of the observation period and after removal of the patches. Yet, fluctuations of hormone concentrations were greater with the matrix system patches, and the areas under the E2 concentration-time curves were slightly but not significantly increased as compared to these of the patches with the reservoir system (3211 +/- 584 vs. 2556 +/- 249 pg/ml x h). In conclusion, both transdermal estradiol delivery systems are well suited for postmenopausal hormone substitution providing stable serum estradiol concentrations at about 50 pg/ml, with the matrix system possibly increasing the life span of the patch and thus the recommended application period.

Diffusion characteristics of placental preparations affect the digoxin passage across the isolated placental lobule.

Our aim was to evaluate the isolated placental lobule to study maternofetal transplacental digoxin transfer and accumulation in placental tissue in vitro. Digoxin passage across the isolated lobule of 10 human placentas was calculated from repeated fetal and maternal perfusate samples, and placental tissue digoxin concentrations were measured at the end of the experiments. To determine the degree of overlap of the fetal and the maternal circulation, the antipyrine clearance was used. Digoxin disappearance from the maternal circuit was not significantly affected by the degree of overlap. In contrast, the increase of digoxin in the fetal compartment was significantly higher in "well-perfused" placentas (antipyrine clearance > 1.60 ml/min; n = 5) than in "malperfused" placentas (antipyrine clearance < 1.50 ml/min; n = 5) (end-feto to initial maternal digoxin ratio 0.44 +/- 0.08 vs. 0.30 +/- 0.08; p < 0.05), whilst the accumulation in placental tissue was higher in the latter group (0.45 +/- 0.07 vs. 0.62 +/- 0.10 ng/mg protein; p < 0.05). We conclude that the isolated placental lobule is suitable to quantify transplacental digoxin transfer in vitro, but the diffusion characteristics of each preparation have to be considered.

Immunological responses to the tumor-associated antigen CA125 in patients with advanced ovarian cancer induced by the murine monoclonal anti-idiotype vaccine ACA125.

We have generated an immunoglobulin G1 (IgG1) murine monoclonal anti-idiotype antibody (Ab2) designated ACA125, which mimics a specific epitope on the tumor-associated antigen CA125. This antigen is expressed by most of malignant ovarian tumors. Patients with CA125-positive tumors are immunologically tolerant to CA125. We used ACA125 as a surrogate for the tumor-associated antigen CA125 for vaccine therapy of 16 patients with advanced epithelial ovarian cancer or recurrences. Each of the patients received a minimum of 3 injections up to 19 injections of the complete anti-idiotype MAb ACA125 at a dosage of 2 mg per injection. Nine of 16 patients developed anti-anti-idiotypic (Ab3) responses to the ACA125. All 9 patients generated specific anti-CA125 antibody demonstrated by reactivity with purified CA125. Nine of 16 patients developed a CA125-specific cellular immune response by their peripheral blood lymphocytes (PBL) and 3 of 16 showed an increase in gamma-interferon concentrations accompanied by Ab3 responses. Toxicity was limited to abdominal pain in one case, which led to the withdrawal of further immunizations. The median progression free survival in those patients, who showed a specific immune response to the tumor-associated antigen CA125, was 11.0 +/- 5.6 months without any other therapy, in contrast to 8.0 +/- 4.2 months in the anti-anti-idiotype negative group. This is the first report of the induction of a specific active immunity to the tumor-associated antigen CA125 in patients with advanced ovarian cancer treated with an anti-idiotype antibody that "mimics" CA125. Patients showed the development of a specific humoral and cellular immune response to an otherwise nonimmunogenic tumor antigen. The immune responses in patients treated with this anti-idiotype vaccine, the low rate of side effects, and the improved time to progression after the induction of a specific immune response against the tumor-associated antigen CA125 justify follow-up clinical trials in advanced ovarian cancer patients with minimal residual disease in an adjuvant approach.

Anti-TAG-72 antibody B72.3--immunological and clinical effects in ovarian carcinoma.

Based on the network theory, anti-tumor antibodies (Ab1) can trigger the immune system of the host into a response against tumor cells. Through an immunological cascade, anti-idiotypic antibodies bearing the internal image of epitopes of the nominal antigen (Ab2 beta) are produced that themselves can induce cellular and humoral cytotoxic effects against the antigen-expressing tumor cell. Formation of such antibodies has been shown to be associated with prolonged survival of melanoma, colorectal, and ovarian carcinoma patients. We studied anti-idiotypic antibody (Ab2) responses and clinical outcome of 31 ovarian cancer patients receiving the monoclonal antibody (MAb) B72.3, which targets the ovarian carcinoma associated antigen TAG-72. All patients were treated by surgery and polychemotherapy, which was followed by repeated (mean of 4) injections of 1 mg of the MAb B72.3. A remarkable anti-idiotypic anti-B72.3 response arose in 19 patients, with 9 of them showing a major response with Ab2 serum concentrations greater than 1,000 U/ml ("high-responders"). The median disease-free survival time, as well as the median survival time of these high-responders, was increased as compared to the low- or no responders. Evaluating our data, we conclude that monoclonal antibody treatment with the MAb B72.3 may induce humoral immunological responses in about two-thirds of our study group, although a positive clinical effect may only be expected in patients with excessive anti-idiotypic antibody formation.

Breast preservation versus mastectomy--recurrence and survival rates of primary breast cancer patients treated at the UFK Bonn.

The aim of this retrospective long-term analysis was to evaluate the approach of breast conservation in the light of the results obtained, on the basis of mastectomy, in patients with early breast carcinoma. Additionally, the effect of internal mammary and supraclavicular radiotherapy was analyzed. Therefore, local-regional recurrence (LRR) and survival rates were examined in 411 patients with T1 and T2 stages who had undergone either breast-preserving surgery with radiation or mastectomy. Individual risk factors such as nodal status, lymphangiosis carcinomatosa and age of the patients were evaluated, too. The rate of local-regional recurrence in patients who were treated by mastectomy and conservative surgery was 9.2% and 11.0%, respectively, with relapse happening earlier in the latter group (median of 16 vs. 24 months). Survival rates, however, were not different in the two groups. Tumour stage and nodal status had no influence on the local-regional recurrence rate in either group. In connection with lymphangiosis carcinomatosa, however, the rate increased to 14.5% (mastectomy) and 19.0% (breast-preserving surgery), respectively. Patients < or = 40 years had an even higher risk of LRR, with 20.6% when they underwent mastectomy and 30.8% following breast conservation. Internal mammary and supraclavicular radiotherapy had no positive effect on the survival rates, neither in the mastectomy nor in the breast conservation group. As a conclusion, in more than 60% of all T1 stages. and more than 50% of all T2 stages, the therapeutic concept of breast preservation seems to be justified.

[Criteria for successful outcome of external fetal version from breech presentation to cephalic presentation]. / Erfolgskriterien für die äussere Wendung des Feten aus Beckenendlage in Schädellage.

The technique of external version of breech presentations has been proposed as a tool to reduce morbidity of fetus and mother. 79 cases of a 3 year period were evaluated aiming at identification of risk factors improving the success rate of the intervention. A total of 48% of attempts was successful. The most frustrating single factor was identified to be the oligohydramnion. Posterior implantation of the placenta improved the rate to 61%. The umbilical cord being localized by coloured Doppler had little influence even if positioned around the neck as neither success nor complications were predictable in this case. Maternal adipositas had a negative influence on the success rate. Perinatal morbidity war not increased in the group of external versions.

[Modification of transplacental digoxin transfer in the isolated placental lobule]. / Einflussfaktoren des transplazentaren Digoxintransfers im isolierten Plazentalobulus.

Digoxin is widely used in the transplacental therapy of fetal tachyarrhythmia. Unfortunately, in cases with severe cardiac insufficiency and hydrops fetalis, transplacental passage of digoxin is often hampered and therapy therefore ineffective. The present study was designed to establish the isolated placental lobule to quantify transplacental digoxin passage under different experimental conditions. Ten human placentas were obtained immediately after delivery, and a lobule was dually perfused after cannulating a small artery and vein of the chorionic plate and piercing four catheters through the corresponding basal plate. Flow rates were 12 ml/min in the maternal circuit and 6 (I) respectively 3 ml/min (II) in the fetal circuit. The maternal circuit was spiked with digoxin to 6.18 +/- 0.40 ng/ml, and transplacental passage was calculated from repeated fetal and maternal perfusate samples (Fluorescence-Polarization-Immunoassay; TDx, Abbott Laboratories). Within three hours of recirculating perfusion with a fetal flow rate of 6 ml/min (I), digoxin concentrations in the maternal circuit (400 ml) declined to 3.56 +/- 0.09 ng/ml, whereas digoxin levels in the fetal compartment (200 ml) increased to 2.58 +/- 0.37 ng/ml. With a fetal perfusion rate of 3 ml/min (II), the efflux of digoxin out of the maternal circuit was lower (p < 0.05) and the influx in the total compartment was reduced (fetal digoxin concentrations reached only 26.9 +/- 10.6% vs. 39.1 +/- 5.5% of the initial maternal digoxin concentrations). These data suggest that severe fetal cardiac insufficiency with reduced placental perfusion may be in part responsible for the decrease of transplacental digoxin passage in fetuses with hydrops.

A simple and sensitive assay for determination of human anti-idiotypic anti-B72.3 antibodies, which is not affected by the presence of tumour-associated glycoprotein 72.

An immunoradiometric assay is described for the determination of human anti-idiotypic anti-B72.3 IgG. The latter is formed in ovarian cancer patients after treatment with the murine monoclonal antibody B72.3, which is directed against the tumour-associated glycoprotein 72 (TAG-72). A gel coupled with Fc-specific anti-human IgG antibodies is used as a solid phase for the extraction of serum IgG. The anti-B72.3 IgG is then specifically detected by incubation with radiolabelled B72.3 detector antibodies. Calibration standards were prepared from serum obtained from a patient repeatedly treated with B72.3 antibodies. The concentration of anti-idiotypic anti-B72.3 antibodies was expressed as TAG-72-like arb.units/1. The assay performed with two 60-minute incubation steps is characterized by a high sensitivity (detection limit: 3 x 10(3) arb.units/1) and precision (coefficients of variation: intra-assay = 6.4% and 5.8% at 80 x 10(3) arb. units/1 and 217 x 10(3) arb.units/1, inter-assay = 8.7% and 7.1% at 91 x 10(3) arb.units/1 and 212 x 10(3) arb.units/1) and a good linearity of dilution (recovery after dilution between 99% and 107%). The assay is more specific than previously described methods; no interference was observed by TAG-72 up to 3.3 x 10(7) arb.units/1. Also, non-specific human anti-mouse antibodies did not cross-react up to 34.8 mg/l. The test may be modified for detection of anti-idiotypic antibodies, which are formed after treatment with other monoclonal antibodies.

Digoxin transfer across the isolated placenta is influenced by maternal and fetal albumin concentrations.

The aim of this study was to evaluate the influence of different maternal and fetal albumin concentrations on the transplacental transfer and the placental tissue accumulation of digoxin. Digoxin passage across the isolated lobules of 15 human placentae was calculated from repeated fetal and maternal perfusate samples, and placental tissue digoxin concentrations were measured at the end of the experiments. Metildigoxin (Lanitop) was added to the maternal medium at a concentration of 5.70 +/- 0.73 ng mL-1, and maternal and fetal perfusate albumin (BSA) concentrations were kept equal either at a high concentration of 21 g L-1 (Group I; n = 5) or at a low concentration of 3 g L-1 (Group III; n = 5), or differed with a materno-fetal gradient of 21:3 g L-1 (Group II; n = 5). In the experiments with low maternal albumin concentrations (Group III), digoxin concentrations in the maternal circuit decreased to 3.56 ng mL-1, whereas digoxin concentrations in the fetal circuit reached 2.59 ng mL-1 over a 3-h period. With maternal BSA concentrations of 21 g L-1 (Group I and Group II), the decrease in digoxin concentration in the maternal circuit was lower (P < 0.05), and digoxin tissue concentrations at the end of the experiments were smaller (0.45 +/- 0.07 and 0.42 +/- 0.03 v. 0.82 +/- 0.32 ng mg-1 protein, Group I and Group II v. Group III respectively; P < 0.05). Comparing only those lobules with similar high concentrations of maternal protein, fetal BSA concentrations of 21 g L-1 resulted in a greater increase in digoxin concentrations in the fetal circuit (end-feto to initial-maternal digoxin concentrations of 0.44 +/- 0.08 v. 0.37 +/- 0.04 ng mg-1 protein (Group I v. Group II respectively), although this was not significant. The data suggest that maternal and fetal serum albumin concentrations may have an influence on transplacental digoxin transfer, and this should be considered when treating fetuses with cardiac disease transplacentally with glycosides.