Optical pulse of a periodic radio star.

The pulsating radio star reported by Hewish et al. (1) has been studied in the blue region of the optical spectrum and found to have a pulse amplitude less than 10 percent of the photon count expected for 18th magnitude. No upper limit to a sinusoidal oscillation less than or equal to a complete modulation can be set.

The influence of leptin on placental and fetal volume measured by three-dimensional ultrasound in the second trimester.

For a couple of years mechanisms influencing placental and fetal growth and the functioning of leptin, the protein product of the ob/ob gene, have been subjects of intensive research. This study's aim was to investigate whether maternal serum leptin and amniotic fluid leptin have an influence on placental and fetal size measured by three-dimensional ultrasound in the second trimester. To determine this, 40 women with a singleton intrauterine pregnancy at the time of the amniocentesis were included in the study. Placental and fetal volume measurements were obtained and correlated to maternal serum leptin, amniotic fluid leptin, body mass index and gestational age. Multiple regression analysis identified amniotic fluid leptin as an independent negative predictor of placental and fetal volume (r = -2.29, p = 0.032 and r = -0.95, p = 0.011, respectively). In contrast, there was no correlation between maternal serum leptin and placental or fetal volume. The median leptin level in amniotic fluid (9.5 ng/ml) was significantly lower than in maternal blood (18.6 ng/ml). However, there was no significant correlation between maternal serum leptin and amniotic fluid leptin (r = 0.208, n.s.). Body mass index did not reveal any significant influences on placental or fetal volume. The relatively high level of amniotic fluid leptin and its inverse correlation on placental and fetal volume in the second trimester suggest that it possibly plays a role as an anti-placental growth hormone or feedback modulator of substrate supply to the fetus and placenta.

Expression of the cloned genes encoding the putrescine biosynthetic enzymes and methionine adenosyltransferase of Escherichia coli (speA, speB, speC and metK).

The speA, speB and speC genes, which code for arginine decarboxylase (ADCase), agmatine ureohydrolase (AUHase) and ornithine decarboxylase (ODCase), respectively, and the metK gene, which encodes methionine adenosyltransferase (MATase), have been cloned. The genes were isolated from hybrid ColE1 plasmids of the Clarke-Carbon collection and were ligated into plasmid pBR322. Escherichia coli strains transformed with the recombinant plasmids exhibit a 7- to 17-fold overproduction of the various enzymes, as estimated from increases in the specific activities of the enzymes assayed in crude extracts. Minicells bearing the pBR322 hybrid plasmids and labeled with radioactive lysine synthesize radiolabeled proteins with Mrs corresponding to those reported for purified ODCase, ADCase and MATase. Restriction enzyme analysis of the plasmids, combined with measurements of specific activities of the enzymes in crude extracts of cells bearing recombinant plasmids, clarified the relative position of speA and speB. The gene order in the 62- to 64-min region is serA speB speA metK speC glc.

A 15-year overview of management and prognosis in primary fallopian tube carcinoma. Austrian Cooperative Study Group for Fallopian Tube Carcinoma.

143 women treated in 28 departments from 1980 to 1995 were retrospectively analysed to study the impact of prognostic factors in primary carcinoma of the fallopian tube. The mean age of the patients was 62.5 years. Sixty (42%) tumours were FIGO stage I, 28 (20%) stage II, 38 (27%) stage III, 17 (12%) stage IV. Complete radical resection was achieved in 102 (71%) patients. In 122 (85%) women, surgery involved removal of the uterus, the adnexa, and/or the omentum or lymph nodes. Postoperative therapy consisted of either irradiation (n = 40; 28%) or chemotherapy (n = 70; 49%); 33 women (23%) did not receive any treatment after surgery. The 5-year survival rate for all cases was 43%. The 5-year survival rate was 59% for stages I and II and 19% for stages III and IV (P < 0.00001). FIGO stage, histological grade and presence of residual tumour had an independent prognostic impact in multivariate analysis. In order to investigate the role of p53 in primary fallopian tube carcinomas, we analysed the immunohistochemical expression of p53 protein regarding survival and FIGO stage in 63 patients (44%). No statistical significance was observed.

Prospective evaluation of hemostatic system activation and thrombin potential in healthy pregnant women with and without factor V Leiden.

Normal pregnancy is associated with alterations of the hemostatic system towards a hypercoagulable state and an increased risk of venous thromboembolism. The risk of venous thrombosis is higher in pregnant women with factor V Leiden (FVL) than in those with wildtype factor V. Routine laboratory assays are not useful to detect hypercoagulable conditions. A prospective and systematic evaluation of hemostatic system activation in women with and without FVL during an uncomplicated pregnancy employing more sensitive markers of hypercoagulability, such as prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT), D-Dimer, or the endogenous thrombin potential (ETP), an indicator of the plasma's potential to generate thrombin, has not been performed. We prospectively followed 113 pregnant women with (n = 11) and without (n = 102) FVL and measured F1+2. TAT, D-Dimer and the ETP at the 12th, 22nd and 34th gestational week as well as 3 months after delivery (baseline) in each subject. None of the women developed clinical signs of venous thromboembolism during pregnancy or postpartum. Pregnant women with and without FVL exhibited substantial activation of the coagulation and fibrinolytic system as indicated by a gradual increase of F1+2, TAT and D-Dimer throughout uncomplicated pregnancy up to levels similar to those found in acute thromboembolic events (p < 0.0001 by analysis of variance for each parameters). Levels of F1+2 and TAT were comparable between women with and without FVL, but levels of D-Dimer were significantly higher in women with FVL than in those without the mutation (p = 0.0005). The ETP remained unchanged in both women with and without FVL at all timepoints. Our data demonstrate a substantial coagulation and fibrinolytic system activation in healthy women with and without FVL during uncomplicated pregnancy. An elevated F1+2, TAT or D-Dimer level during pregnancy is not necessarily indicative for an acute thromboembolic event. The normal ETP in both women with and without FVL suggests that the capacity of the plasma to generate thrombin after in vitro activation of the clotting system is not affected by pregnancy. Higher levels of D-Dimer in women with FVL than in women with wildtype factor V at baseline as well as during pregnancy indicate increased fibrinolytic system activation in carriers of the mutation.

Correlation of first trimester placental volume and second trimester uterine artery Doppler flow.

Uterine artery Doppler examination can identify impaired trophoblast invasion in the second trimester of pregnancy. High resistance and an early diastolic 'notch' show insufficient physiological conversion of the spiral arteries. Uterine artery Doppler is routinely performed between 22-24 weeks which is relatively late for treatment. In this study we wanted to find out whether women with increased uterine blood flow resistance at 22 weeks already have reduced placental volumes in the first trimester measured with 3D sonography.A total of 1060 women with singleton pregnancies had three dimensional (3D) volume measurements of their placentae between 11-13 weeks and uterine Doppler scans between 21-22 weeks. Stepwise logistic and linear regression analyses were used to show a correlation between placental volume (PV) and a CRL dependent placental quotient (PQ) with uterine perfusion parameters. Uterine perfusion at 21-22 weeks depends significantly on PV or PQ at 11-13 weeks (P< 0.0001 for both) and smoking behaviour (P=0.006). The occurrence of a notch also depends significantly on PV and PQ (P< 0.0001 for both) and also on gravidity (P< 0.0001) and age (P=0.0007) as well as on smoking behaviour (P=0.0094). PV and PQ did not show any dependency on age, gravidity, BMI or smoking habits. Placentae of women with high resistance uterine perfusion in the second trimester are already remarkably small in the first trimester. Placental volumetry is probably an efficient method for early and simple identification of impaired trophoblast invasion.

Three-dimensional ultrasound measurement of the placental volume in early pregnancy: method and correlation with biochemical placenta parameters.

Placental size has been an interesting topic of research for many years. The main aim of this study was to investigate the feasibility of measuring the placental volume at the end of the first trimester using three-dimensional (3D) ultrasound and to correlate these volumes to known placental functional indices and to factors affecting the placenta. Women with singleton pregnancies at the end of the first trimester were included into this study. The volume data of the placentae were correlated to the crown-rump length (CRL), placenta-associated plasma protein A (PAPP-A), free beta-human chroangiogonadotropin (f-beta-hCG) and other factors that may affect the placental size or function. A total of 1462 pregnancies could be evaluated. Comparison between CRL and placental volume proved a significant correlation (r=0.43, P< 0.001). Due to the observed proportional growth of CRL and placental volume, a quotient (placental volume/CRL) was calculated for each case. There were no differences between placenta/CRL-quotients in relation to gravidity, parity or smoking. Correlations could be established between the placental volume and PAPP-A and f-beta-hCG (PAPP-A: r=0.28, P< 0.001, f-beta-hCG: r=0.10, P< 0.001). The measurement of the placenta in the first trimester can be performed in a high percentage of cases. The placenta/CRL quotient represents a simple method to compare placentae from different gestational days. The correlation between placental volume and maternal serum screening parameters might provide a chance to refine first trimester Down's syndrome serum screening. Future studies will be needed to evaluate the possible clinical use of first trimester placental volume measurements.

Placental growth from the first to the second trimester of pregnancy in SGA-foetuses and pre-eclamptic pregnancies compared to normal foetuses.

The aim of this study was to determine placental growth between 12-22 weeks in normal pregnancies compared to pregnancies complicated by foetal SGA and maternal pre-eclampsia (PE). The placentae of 1199 women were measured 3D sonographically at 12, 16 and 22 weeks of gestation. Placental volume growth was then calculated. Neonatal birthweight, birth centile and the occurrence of pre-eclampsia were recorded in every woman and correlated with placental growth (four groups: normals, SGA, PE, SGA+PE). SGA-placentae are already smaller at 12 weeks but then develop in a similar way to normal placentae. PE placentae are slightly, but significantly, larger at 12 weeks, grow rapidly until 16 weeks and then stop growing normally between 16 and 22 weeks. If SGA goes together with PE, both placental volume (PV) at 12 weeks as well as growth is reduced significantly. Nevertheless, placental growth between week 12 and 22 is too heterogeneous to justify using this method as a clinical tool, but it can provide new information on placental physiology underlying unfavourable obstetric outcomes.

Cloning of a DNA fragment involved in pigment production in Streptomyces avermitilis.

Streptomyces avermitilis has the ability to synthesize a diffusible, brown, melanin-like pigment, a common property among many Streptomyces species. A region of the S. avermitilis chromosome involved in the production of this pigment was cloned in Escherichia coli. Production of the brown pigment was attained in E. coli, and is optimal when medium is supplemented with copper ions, tyrosine and IPTG. The cloned S. avermitilis pigment-producing DNA fragment is under the control of the lac promoter carried in the E. coli vector. The gene involved in pigment production could be used as a tool to analyse gene expression in S. avermitilis, and as an alternative cloning marker in Streptomyces-Escherichia coli vectors.

Branched-chain fatty acid requirement for avermectin production by a mutant of Streptomyces avermitilis lacking branched-chain 2-oxo acid dehydrogenase activity.

The eight natural avermectins produced by Streptomyces avermitilis have the carbon skeleton of either isobutyric or S-2-methylbutyric acid incorporated into their structures. A mutant of S. avermitilis has been isolated that contains no functional branched-chain 2-oxo acid dehydrogenase activity. The mutant, in contrast to its parent, is unable to grow with isoleucine, valine and leucine as carbon sources. In medium lacking both S(+)-2-methylbutyric and isobutyric acid, the mutant is also incapable of making the natural avermectins, while supplementation with either one of these compounds restores production of the corresponding four natural avermectins. These facts indicate that in S. avermitilis the branched-chain 2-oxo acid dehydrogenase enzyme functions not only to catabolize the cellular branched-chain amino acids in order to meet energy and growth requirements but also to provide the small branched-chain organic acid precursor molecules necessary for avermectin biosynthesis. Supplementation of the mutant strain with R(-)-2-methylbutyric acid yields novel isomeric avermectins unseen in the (unsupplemented) wild-type strain. It was also concluded that acetate and propionate production by branched-chain 2-oxo acid degradation is not absolutely essential for avermectin production.

[Placental isoferritin (PLF): early predictor of fetal growth retardation]. / Früherkennung fetaler Wachstumsretardierung durch Bestimmung des plazentaren Isoferritins.

OBJECTIVE: Maternal immunoreaction against the embryo can be responsible for fetal growth retardation. The secretion of PLF during pregnancy could be reliable for a diminished immunoreaction of maternal lymphocytes against the embryo. The aim of the present study was to elucidate a possible correlation between PLF and fetal growth retardation. METHODS: In this study, blood samples of 402 pregnant women were obtained between the 12th and 16th weeks of gestation. The serum levels of PLF were compared with birth weight, percentile of birth weight, and gestational age. RESULTS: Women with children whose birth weight was below or equal to the 10th percentile for gestational age showed significantly lower PLF levels (11.4 U/ml, n = 107) as compared with women whose newborns were of normal weight (19.9 U/ml, n = 295; p < 0.004). CONCLUSION: Determination of the PLF level could serve to identify women at risk of having growth-retarded babies.

Measurement of placental bed vascularization in the first trimester, using 3D-power-Doppler, for the detection of pregnancies at-risk for fetal and maternal complications.

OBJECTIVE: To evaluate the performance of placental bed vascularization in a low-risk population to predict severe pregnancy risks. Vascularization was measured in the first trimester, using 3D power-Doppler vascularization index. METHODS: All women who registered during a period of 3 years for delivery in our hospital were prospectively screened in the first trimester. Power Doppler vascularization index of the placental bed (PBVI) was measured in 4325 women and correlated to 7 outcome groups: 1) normal, 2) IUGR ≤ 3rd centile, 3) delivery ≤ 34 weeks, 4) pregnancy induced hypertension (PIH), 5) all pre-eclampsia (PE), 6) severe PE, 7) severe pregnancy problems (SPP i.e. PIH or PE plus IUGR ≤ 3rd centile and/or delivery ≤ 34 weeks). In addition, measurements of mean uterine artery Doppler at 12 and 22 weeks, placental volume and PAPP-A were also performed on all women and their predictive strength for pregnancy risks was compared with the PBVI. RESULTS: Severe PE and SPP occurred in 0.6 vs. 1.5% of all pregnancies. First trimester PBVI below the 10th centile detected 60% of severe PE and 66.2% of SPP, the odds ratio being 4.48 (95th CI 1.98-11.82) for severe PE and 9.92 (95th CI 5.55-17.71) for SPP. Second trimester uterine artery Doppler detected 72% of PE and 50.8% of SPP, the odds ratio being 14.58 (95th CI 5.78-36.79) and 5.46 (95th CI 3.18-9.36) respectively. All other measured parameters performed much worse compared to PBVI and 22 weeks uterine artery Doppler. CONCLUSION: Placental bed vascularization index could be used for a quick and reliable first trimester assessment of severe pregnancy risks.

First trimester placental and myometrial blood perfusion measured by 3D power Doppler in normal and unfavourable outcome pregnancies.

INTRODUCTION: To evaluate whether 3D placental and myometrial power Doppler blood perfusion in the first trimester can be used to detect risk pregnancies. METHODS: 3D power Doppler vascularization index (VI) and flow index (FI) of the entire placenta and the neighbouring myometrium were separately measured in the first trimester in all women with singleton pregnancies during a period of three months. In addition we measured placental volume, placental quotient, PAPP-A, as well as uterine artery at 12 and 22 weeks (mean PI and mean notch) and compared those data with the pregnancy outcome. RESULTS: Data from 383 women could be evaluated. 10 developed pre-eclampsia (PE). Both flow and vascularization were markedly lower in the placentas compared to the adjoining decidua and myometria. There was some correlation between placental vascularization Index (PVI) as well as deciduo-myometrial vascularization index (MVI) and placental volume, PAPP-A and number of pregnancies and a marked correlation between PVI and especially MVI to mean notch at 12 weeks and 22 weeks (PVI: -0.215, -0.274 MVI: -0.316,-0.322). PVI and MVI were significantly reduced in women with pregnancy problems and showed the greatest reduction in PE-pregnancies (p: 0.0018, 0.0004). Of all measured parameters MVI showed the best sensitivity for the detection of PE. CONCLUSION: The correlation between PVI and MVI in the first trimester and mean notch in the second shows that they provide valuable information at as early as 12 weeks which normally so far is only available at 22 weeks by uterine artery Doppler flow. As MVI measures the percentage of vessels in the deciduo-myometrial area it could also provide information on trophoblast invasion. This hypothesis is supported in particular by a marked decrease of the MVI in pregnancy problems especially in PE-pregnancies.