A DELAY OF GERMINATION 1 (DOG1)-like protein regulates spore germination in the moss Physcomitrium patens

DELAY OF GERMINATION 1 is a key regulator of dormancy in flowering plants before seed germination. Bryophytes develop haploid spores with an analogous function to seeds. Here, we investigate whether DOG1 function during germination is conserved between bryophytes and flowering plants and analyse the underlying mechanism of DOG1 action in the moss Physcomitrium patens. Phylogenetic and in silico expression analyses were performed to identify and characterise DOG1 domain-containing genes in P. patens. Germination assays were performed to characterise a Ppdog1-like1 mutant, and replacement with AtDOG1 was carried out. Yeast two-hybrid assays were used to test the interaction of the PpDOG1-like protein with DELLA proteins from P. patens and A. thaliana. P. patens possesses nine DOG1 domain-containing genes. The DOG1-like protein PpDOG1-L1 (Pp3c3_9650) interacts with PpDELLAa and PpDELLAb and the A. thaliana DELLA protein AtRGA in yeast. Protein truncations revealed the DOG1 domain as necessary and sufficient for interaction with PpDELLA proteins. Spores of Ppdog1-l1 mutant germinate faster than wild type, but replacement with AtDOG1 reverses this effect. Our data demonstrate a role for the PpDOG1-LIKE1 protein in moss spore germination, possibly alongside PpDELLAs. This suggests a conserved DOG1 domain function in germination, albeit with differential adaptation of regulatory networks in seed and spore germination.

DELLA proteins regulate spore germination and reproductive development in Physcomitrium patens

Proteins of the DELLA family integrate environmental signals to regulate growth and development throughout the plant kingdom. Plants expressing non-degradable DELLA proteins underpinned the development of high-yielding 'Green Revolution' dwarf crop varieties in the 1960s. In vascular plants, DELLAs are regulated by gibberellins, diterpenoid plant hormones. How DELLA protein function has changed during land plant evolution is not fully understood. We have examined the function and interactions of DELLA proteins in the moss Physcomitrium (Physcomitrella) patens, in the sister group of vascular plants (Bryophytes). PpDELLAs do not undergo the same regulation as flowering plant DELLAs. PpDELLAs are not degraded by diterpenes, do not interact with GID1 gibberellin receptor proteins and do not participate in responses to abiotic stress. PpDELLAs do share a function with vascular plant DELLAs during reproductive development. PpDELLAs also regulate spore germination. PpDELLAs interact with moss-specific photoreceptors although a function for PpDELLAs in light responses was not detected. PpDELLAs likely act as 'hubs' for transcriptional regulation similarly to their homologues across the plant kingdom. Taken together, these data demonstrate that PpDELLA proteins share some biological functions with DELLAs in flowering plants, but other DELLA functions and regulation evolved independently in both plant lineages.

A vertically transmitted amalgavirus is present in certain accessions of the bryophyte Physcomitrium patens

In the last few years, next-generation sequencing techniques have started to be used to identify new viruses infecting plants. This has allowed to rapidly increase our knowledge on viruses other than those causing symptoms in economically important crops. Here we used this approach to identify a virus infecting Physcomitrium patens that has the typical structure of the double-stranded RNA endogenous viruses of the Amalgaviridae family, which we named Physcomitrium patens amalgavirus 1, or PHPAV1. PHPAV1 is present only in certain accessions of P. patens, where its RNA can be detected throughout the cell cycle of the plant. Our analysis demonstrates that PHPAV1 can be vertically transmitted through both paternal and maternal germlines, in crosses between accessions that contain the virus with accessions that do not contain it. This work suggests that PHPAV1 can replicate in genomic backgrounds different from those that actually contain the virus and opens the door for future studies on virus-host coevolution.

HAG1 and SWI3A/B control of male germ line development in P. patens suggests conservation of epigenetic reproductive control across land plants

KEY MESSAGE

Bryophytes as models to study the male germ line: loss-of-function mutants of epigenetic regulators HAG1 and SWI3a/b demonstrate conserved function in sexual reproduction. With the water-to-land transition, land plants evolved a peculiar haplodiplontic life cycle in which both the haploid gametophyte and the diploid sporophyte are multicellular. The switch between these phases was coined alternation of generations. Several key regulators that control the bauplan of either generation are already known. Analyses of such regulators in flowering plants are difficult due to the highly reduced gametophytic generation, and the fact that loss of function of such genes often is embryo lethal in homozygous plants. Here we set out to determine gene function and conservation via studies in bryophytes. Bryophytes are sister to vascular plants and hence allow evolutionary inferences. Moreover, embryo lethal mutants can be grown and vegetatively propagated due to the dominance of the bryophyte gametophytic generation. We determined candidates by selecting single copy orthologs that are involved in transcriptional control, and of which flowering plant mutants show defects during sexual reproduction, with a focus on the under-studied male germ line. We selected two orthologs, SWI3a/b and HAG1, and analyzed loss-of-function mutants in the moss P. patens. In both mutants, due to lack of fertile spermatozoids, fertilization and hence the switch to the diploid generation do not occur. Pphag1 additionally shows arrested male and impaired female gametangia development. We analyzed HAG1 in the dioecious liverwort M. polymorpha and found that in Mphag1 the development of gametangiophores is impaired. Taken together, we find that involvement of both regulators in sexual reproduction is conserved since the earliest divergence of land plants.

A blind and independent benchmark study for detecting differeally methylated regions in plants

MOTIVATION

Bisulfite sequencing (BS-seq) is a state-of-the-art technique for investigating methylation of the DNA to gain insights into the epigenetic regulation. Several algorithms have been published for identification of differentially methylated regions (DMRs). However, the performances of the individual methods remain unclear and it is difficult to optimally select an algorithm in application settings.

RESULTS

We analyzed BS-seq data from four plants covering three taxonomic groups. We first characterized the data using multiple summary statistics describing methylation levels, coverage, noise, as well as frequencies, magnitudes and lengths of methylated regions. Then, simulated datasets with most similar characteristics to real experimental data were created. Seven different algorithms (metilene, methylKit, MOABS, DMRcate, Defiant, BSmooth, MethylSig) for DMR identification were applied and their performances were assessed. A blind and independent study design was chosen to reduce bias and to derive practical method selection guidelines. Overall, metilene had superior performance in most settings. Data attributes, such as coverage and spread of the DMR lengths, were found to be useful for selecting the best method for DMR detection. A decision tree to select the optimal approach based on these data attributes is provided. The presented procedure might serve as a general strategy for deriving algorithm selection rules tailored to demands in specific application settings.

AVAILABILITY AND IMPLEMENTATION

Scripts that were used for the analyses and that can be used for prediction of the optimal algorithm are provided at https://github.com/kreutz-lab/DMR-DecisionTree. Simulated and experimental data are available at https://doi.org/10.6084/m9.figshare.11619045.

CONTACT

ckreutz@imbi.uni-freiburg.de.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Single Nucleotide Polymorphism Charting of P. patens Reveals Accumulation of Somatic Mutations During in vitro Culture on the Scale of Natural Variation by Selfing

Introduction: Physcomitrium patens (Hedw.) Mitten (previously known as Physcomitrella patens) was collected by H.L.K. Whitehouse in Gransden Wood (Huntingdonshire, United Kingdom) in 1962 and distributed across the globe starting in 1974. Hence, the Gransden accession has been cultured in vitro in laboratories for half a century. Today, there are more than 13 different pedigrees derived from the original accession. Additionally, accessions from other sites worldwide were collected during the last decades. Methods and Results: In this study, 250 high throughput RNA sequencing (RNA-seq) samples and 25 gDNA samples were used to detect single nucleotide polymorphisms (SNPs). Analyses were performed using five different P. patens accessions and 13 different Gransden pedigrees. SNPs were overlaid with metadata and known phenotypic variations. Unique SNPs defining Gransden pedigrees and accessions were identified and experimentally confirmed. They can be successfully employed for PCR-based identification. Conclusion: We show independent mutations in different Gransden laboratory pedigrees, demonstrating that somatic mutations occur and accumulate during in vitro culture. The frequency of such mutations is similar to those observed in naturally occurring populations. We present evidence that vegetative propagation leads to accumulation of deleterious mutations, and that sexual reproduction purges those. Unique SNP sets for five different P. patens accessions were isolated and can be used to determine individual accessions as well as Gransden pedigrees. Based on that, laboratory methods to easily determine P. patens accessions and Gransden pedigrees are presented.

Characterisation of evolutionarily conserved key players affecting eukaryotic flagellar motility and fertility using a moss model

Defects in flagella/cilia are often associated with infertility and disease. Motile male gametes (sperm cells) are an ancestral eukaryotic trait that has been lost in several lineages like flowering plants. Here, we made use of a phenotypic male fertility difference between two moss (Physcomitrella patens) ecotypes to explore spermatozoid function. We compare genetic and epigenetic variation as well as expression profiles between the Gransden and Reute ecotype to identify a set of candidate genes associated with moss male infertility. We generated a loss-of-function mutant of a coiled-coil domain containing 39 (ccdc39) gene that is part of the flagellar hydin network. Defects in mammal and algal homologues of this gene coincide with a loss of fertility, demonstrating the evolutionary conservation of flagellar function related to male fertility across kingdoms. The Ppccdc39 mutant resembles the Gransden phenotype in terms of male fertility. Potentially, several somatic (epi-)mutations occurred during prolonged vegetative propagation of Gransden, causing regulatory differences of for example the homeodomain transcription factor BELL1. Probably these somatic changes are causative for the observed male fertility defect. We propose that moss spermatozoids might be employed as an easily accessible system to study male infertility of humans and animals in terms of flagellar structure and movement.

DEK1 displays a strong subcellular polarity during Physcomitrella patens 3D growth

Defective Kernel 1 (DEK1) is genetically at the nexus of the 3D morphogenesis of land plants. We aimed to localize DEK1 in the moss Physcomitrella patens to decipher its function during this process. To detect DEK1 in vivo, we inserted the tdTomato fluorophore into PpDEK1 gene locus. Confocal microscopy coupled with the use of time-gating allowed the precise DEK1 subcellular localization during 3D morphogenesis. DEK1 localization displays a strong polarized signal, as it is restricted to the plasma membrane domain between recently divided cells during the early steps of 3D growth development as well as during the subsequent vegetative growth. The signal furthermore displays a clear developmental pattern because it is only detectable in recently divided and elongating cells. Additionally, DEK1 localization appears to be independent of its calpain domain proteolytic activity. The DEK1 polar subcellular distribution in 3D tissue developing cells defines a functional cellular framework to explain its role in this developmental phase. Also, the observation of DEK1 during spermatogenesis suggests another biological function for this protein in plants. Finally the DEK1-tagged strain generated here provides a biological platform upon which further investigations into 3D developmental processes can be performed.

The Moss Physcomitrium (Physcomitrella) patens: A Model Organism for Non-Seed Plants

Since the discovery two decades ago that transgenes are efficiently integrated into the genome of Physcomitrella patens by homologous recombination, this moss has been a premier model system to study evolutionary developmental biology questions, stem cell reprogramming, and the biology of nonvascular plants. P patens was the first non-seed plant to have its genome sequenced. With this level of genomic information, together with increasing molecular genetic tools, a large number of reverse genetic studies have propelled the use of this model system. A number of technological advances have recently opened the door to forward genetics as well as extremely efficient and precise genome editing in P patens Additionally, careful phylogenetic studies with increased resolution have suggested that P patens emerged from within Physcomitrium Thus, rather than Physcomitrella patens, the species should be named Physcomitrium patens Here we review these advances and describe the areas where P patens has had the most impact on plant biology.

PEATmoss (Physcomitrella Expression Atlas Tool): a unified gene expression atlas for the model plant Physcomitrella patens

Physcomitrella patens is a bryophyte model plant that is often used to study plant evolution and development. Its resources are of great importance for comparative genomics and evo-devo approaches. However, expression data from Physcomitrella patens were so far generated using different gene annotation versions and three different platforms: CombiMatrix and NimbleGen expression microarrays and RNA sequencing. The currently available P. patens expression data are distributed across three tools with different visualization methods to access the data. Here, we introduce an interactive expression atlas, Physcomitrella Expression Atlas Tool (PEATmoss), that unifies publicly available expression data for P. patens and provides multiple visualization methods to query the data in a single web-based tool. Moreover, PEATmoss includes 35 expression experiments not previously available in any other expression atlas. To facilitate gene expression queries across different gene annotation versions, and to access P. patens annotations and related resources, a lookup database and web tool linked to PEATmoss was implemented. PEATmoss can be accessed at https://peatmoss.online.uni-marburg.de.

ABA-Induced Vegetative Diaspore Formation in Physcomitrella patens

The phytohormone abscisic acid (ABA) is a pivotal regulator of gene expression in response to various environmental stresses such as desiccation, salt and cold causing major changes in plant development and physiology. Here we show that in the moss Physcomitrella patens exogenous application of ABA triggers the formation of vegetative diaspores (brachycytes or brood cells) that enable plant survival in unfavorable environmental conditions. Such diaspores are round-shaped cells characterized by the loss of the central vacuole, due to an increased starch and lipid storage preparing these cells for growth upon suitable environmental conditions. To gain insights into the gene regulation underlying these developmental and physiological changes, we analyzed early transcriptome changes after 30, 60, and 180 min of ABA application and identified 1,030 differentially expressed genes. Among these, several groups can be linked to specific morphological and physiological changes during diaspore formation, such as genes involved in cell wall modifications. Furthermore, almost all members of ABA-dependent signaling and regulation were transcriptionally induced. Network analysis of transcription-associated genes revealed a large overlap of our study with ABA-dependent regulation in response to dehydration, cold stress, and UV-B light, indicating a fundamental function of ABA in diverse stress responses in moss. We also studied the evolutionary conservation of ABA-dependent regulation between moss and the seed plant Arabidopsis thaliana pointing to an early evolution of ABA-mediated stress adaptation during the conquest of the terrestrial habitat by plants.

Physcomitrella patens Reute mCherry as a tool for efficient crossing within and between ecotypes

Physcomitrella patens is a monoecious moss that is predominantly selfing in the wild. Laboratory crossing techniques have been established and crosses between the sequenced Gransden ecotype and the genetically divergent Villersexel ecotype were used for genetic mapping. The recently introduced ecotype Reute has a high fertility rate and is genetically more closely related to the Gransden ecotype than the Villersexel ecotype. Reute sexual reproduction phenology is similar to Gransden, which should allow successful crossing. Using the Reute ecotype and an existing Gransden mutant as a test case, we applied a normalised crossing approach to demonstrate crossing potential between these ecotypes. Also, using a standard transformation approach, we generated Reute fluorescent strains expressing mCherry that allow an easy detection of crossed offspring (sporophyte). We show that Reute can be successfully crossed with a self-infertile DR5:DsRed2 mutant generated in the Gransden background. Using newly established Reute fluorescent strains, we show that they can efficiently fertilise Reute as well as Gransden wild type. The resulting progeny display Mendelian 1:1 segregation of the fluorescent marker(s), demonstrating the suitability of such strains for genetic crossing. Overall our results demonstrate that Reute is highly suitable for genetic crossing. The Reute mCherry strain can be used as a suitable background for offspring selection after crossing.

The Physcomitrella patens chromosome-scale assembly reveals moss genome structure and evolution

The draft genome of the moss model, Physcomitrella patens, comprised approximately 2000 unordered scaffolds. In order to enable analyses of genome structure and evolution we generated a chromosome-scale genome assembly using genetic linkage as well as (end) sequencing of long DNA fragments. We find that 57% of the genome comprises transposable elements (TEs), some of which may be actively transposing during the life cycle. Unlike in flowering plant genomes, gene- and TE-rich regions show an overall even distribution along the chromosomes. However, the chromosomes are mono-centric with peaks of a class of Copia elements potentially coinciding with centromeres. Gene body methylation is evident in 5.7% of the protein-coding genes, typically coinciding with low GC and low expression. Some giant virus insertions are transcriptionally active and might protect gametes from viral infection via siRNA mediated silencing. Structure-based detection methods show that the genome evolved via two rounds of whole genome duplications (WGDs), apparently common in mosses but not in liverworts and hornworts. Several hundred genes are present in colinear regions conserved since the last common ancestor of plants. These syntenic regions are enriched for functions related to plant-specific cell growth and tissue organization. The P. patens genome lacks the TE-rich pericentromeric and gene-rich distal regions typical for most flowering plant genomes. More non-seed plant genomes are needed to unravel how plant genomes evolve, and to understand whether the P. patens genome structure is typical for mosses or bryophytes.

Sexual reproduction, sporophyte development and molecular variation in the model moss Physcomitrella patens: introducing the ecotype Reute

Rich ecotype collections are used for several plant models to unravel the molecular causes of phenotypic differences, and to investigate the effects of environmental adaption and acclimation. For the model moss Physcomitrella patens collections of accessions are available, and have been used for phylogenetic and taxonomic studies, for example, but few have been investigated further for phenotypic differences. Here, we focus on the Reute accession and provide expression profiling and comparative developmental data for several stages of sporophyte development, as well as information on genetic variation via genomic sequencing. We analysed cross-technology and cross-laboratory data to define a confident set of 15 mature sporophyte-specific genes. We find that the standard laboratory strain Gransden produces fewer sporophytes than Reute or Villersexel, although gametangia develop with the same time course and do not show evident morphological differences. Reute exhibits less genetic variation relative to Gransden than Villersexel, yet we found variation between Gransden and Reute in the expression profiles of several genes, as well as variation hot spots and genes that appear to evolve under positive Darwinian selection. We analyzed expression differences between the ecotypes for selected candidate genes in the GRAS transcription factor family, the chalcone synthase family and in genes involved in cell wall modification that are potentially related to phenotypic differences. We confirm that Reute is a P. patens ecotype, and suggest its use for reverse-genetics studies that involve progression through the life cycle and multiple generations.

The clinical significance of antenatal pathological Doppler findings in the fetal middle cerebral artery in cases with peripheral reduced diastolic doppler flow but no absence of end-diastolic flow in the umbilical artery or fetal aorta

PURPOSE

The effects of antepartum pathological Doppler findings in the fetal middle cerebral artery in cases with simultaneously peripheral reduced diastolic Doppler flow on perinatal outcome and the odds ratio of perinatal risks were studied.

METHODS

214 patients were examined by color Doppler ultrasound in relationship to complications in gestation and labor and fetal outcome. One thousand and seventy Doppler flow measurements of the middle cerebral artery, the umbilical artery and the fetal aorta between 28 and 40 weeks of gestation were performed. Sensitivity and odds ratio of synchronous cerebral pathological and peripheral pathological Doppler blood flow with regard to the prediction of intrauterine growth retardation, rate of cesarean section, preterm delivery and newborn depression was calculated. In all Doppler measurements there were no cases with absence of end-diastolic flow.

RESULTS

Preterm delivery rate and intrauterine growth retardation rate were significantly higher in cases of synchronous cerebral pathological and peripheral pathological Doppler blood flow as in cases of isolated reduced peripheral blood flow (p<0.001; odds ratio 13.2 and 16.6).

CONCLUSION

Pregnancies with no absence of end-diastolic flow in the fetal aorta or umbilical artery, but with reduced diastolic flow in these vessels and simultaneous pathological Doppler findings in the fetal middle cerebral artery are high risk pregnancies, above all in respect to intrauterine growth retardation, preterm delivery and newborn depression. Surveillance of pregnant women should be performed in a perinatal centre.

Reference ranges and standard percentile-curves for the Doppler indices RI and S/D ratio of the fetal middle cerebral artery. Color Doppler measurements in a perinatal centre

PURPOSE

To perform reference ranges and standard percentile-curves for the Doppler indices resistance index (RI) and systolic/diastolic (S/D) ratio of the fetal middle cerebral artery, periodical color doppler sonographic measurements of 70 pregnant women in the 3rd trimester of pregnancy were done.

METHODS

600 Doppler flow measurements of the fetal middle cerebral artery between 28 and 40 weeks of gestation were performed. The patients had no previous obstetric complications, no apparent medical problems and no complications in pregnancy and labor. Percentiles curves were performed for the RI and the S/D ratio from the 10th percentile up to the 90th percentile.

RESULTS

In the 3rd trimester of pregnancy fetal cerebral circulation shows an increase of the diastolic component and simultaneous decrease in cerebral resistance. The average S/D ratio in week 29 is 8.0, in week 34 6.0 and in the 40th week 3.5. The RI decrement is from 0.88 to 0.67. Other groups demonstrated similar ranges however absolute data are different.

CONCLUSION

The increase in the diastolic component in the middle cerebral artery of the last third of the pregnancy demands reference ranges by using percentile curves. Knowledge of the reference range helps to discriminate between a normal fetal situation and disease. Because of different absolute ranges in the literature each perinatal centre should develop their own data.

The clinical significance of antenatal pathological Doppler findings in fetal middle cerebral artery compared to umbilical artery and fetal aorta

PURPOSE

To compare the diagnostic capacity of fetal Doppler velocimetry in fetal middle cerebral artery to umbilical artery and fetal aorta to the prediction of fetal outcome.

METHODS

229 patients between 28 weeks of gestation (weeks) and 40 weeks were examined by Doppler ultrasound in relationship to complications in gestation and labor, and fetal outcome. One thousand two hundred and seventy doppler blood flow velocity waveforms in the middle cerebral artery, umbilical artery and fetal aorta were recorded. Sensitivity of these vessels with regard to the prediction of intrauterine growth retardation, rate of cesarean section, preterm delivery and new-born depression was calculated. In all Doppler measurements there were no cases with absence of end-diastolic flow.

RESULTS

The differences between pathological fetal outcome were not statistically significant, but diagnostic capacity of the middle cerebral artery velocimetry with regard to the prediction of pathological fetal outcome was on average 11% below the diagnostic capacity of the fetal aorta and umbilical artery.

CONCLUSION

There is no benefit in examining fetal middle cerebral artery Doppler measurements in clinical routine in patients with normal velocity waveforms in the umbilical artery and fetal aorta.

Evaluation of the secretion of the atrial natriuretic factor (ANF) after laparotomy

BACKGROUND

ANF is a potent diuretic, natriuretic and vasorelaxant hormone. The objective of the present study was to examine the effect of opioid receptor stimulation by morphine after surgery on endogenous ANF production and diuresis.

METHODS

Prospectively, 11 women undergoing surgery for either uterine leiomyomas, chronic pelvic discomfort or desire for definitive contraception by laparotomy were evaluated. Venous samples were collected at fixed times. Concentrations of ANF were measured by commercially available radioimmunoassay test kits. Statistical analysis was performed by the Friedman Two way ANOVA. Kruskal-Wallis 1-way ANOVA and Mann-Whitney U-Wilcoxon Rank Sum W Test. The level of significance was set at probability below 0.05.

RESULTS

There were statistically significant changes in the serum levels of ANF (p=0.0028), in pain score (p<0.0001) and urinary flow rate (p<0.0001) after operation, while the diastolic (p=0.0671) and systolic (p=0.0543) blood pressure showed slightly significant changes.

CONCLUSION

Our results show that i.v. administered morphine induces a potent diuretic effect via activation of opioid receptors and suggest that this effect is due to the enhanced release of ANF. However the mechanism by which morphine induces the ANF release remains to be evaluated.

[Intrauterine growth retardation--perinatal mortality and postnatal morbidity in a perinatal center]

OBJECTIVES

The intrauterine growth retardation (IUGR) contributes specially to perinatal mortality and morbidity. An effective treatment is not yet available. The purpose of this study is to analyse the perinatal data of a cohort with IUGR-infants including mortality and morbidity and to describe prematurity and IUGR as a combination of high risk.

STUDY DESIGN

We have analysed the perinatal data of a cohort of 220 patients with IUGR-infants including mortality and morbidity. Regularly we examined fetal ultrasonographic growth, doppler measurements of fetal and maternal vessels and CTG, as well as indicated amniocentesis, placentesis and cordocentesis. Entry criteria were: normal menstrual period before pregnancy, clear gestational age, complete history of pregnancy.

RESULTS

At the Department of Gynaecology & Obstetrics, University Hospital, Homburg/Saar, the incidence of IUGR (< 10th Percentile) in premature babies and newborns was 13.1% over five years (1993-1997). The percentage of premature babies with IUGR was 18.6%. The overall mortality was 4.1%, the perinatal mortality was 3.6% and the neonatal mortality was 2.7%. In 1.4% intrauterine foetal death was observed, all associated with a birthweight below the 3th percentile. The average duration of pregnancy was 34 + 4 weeks. A high perinatal mortality of 13.1% and an overall mortality of 14.7% was observed. 11.4% of the premature babies with IUGR showed deformities and about 2% presented chromosome aberrations. 46.4% of children have been transferred to the Neonatal Intensive Care Unit. 57.1% of the postnatal complications have been related to the lungs, 26.5% to the cardiovascular system and 14.3% to the cerebrum. Maternal complications were referred to: SIH/EPH-gestosis (65.4%), HELLP-syndrome (5.8%), nicotine abuse (31.4%), pregnancy anaemia (17.3%) and gestational diabetes with insuline therapy (7.7%). On the placental site the most noticeable conditions have been placental insufficiency (40.6%) and placental infarction (28.7%).

CONCLUSION

Children with IUGR are exposed to high perinatal mortality and postnatal morbidity. Premature babies in association with an IUGR are at high risk. The surveillance of the pregnant women and the new-born children should be performed in a perinatal centre.

Heterologous mullerian mixed tumor after whole body irradiation because of Hodgkin's disease in stage IV

PURPOSE

With an incidence of 1.5% of all malignant diseases of the uterus as specified in the literature, the mullerian mixed tumor is a rarity amongst the malignancies of the female genital tract.

METHODS

A retrospective analysis of an individual case report with the occurrence of heterologous mullerian mixed tumor years after irradiation because of Hodgkin's disease.

RESULTS

This case reports describes the occurrence of a mullerian mixed tumor 12 years after the treatment of Hodgkin's disease by whole body irradiation. To our knowledge, the incidence of a mullerian mixed tumor after the treatment of Hodgkin's disease has rarely been described up to now in the literature.

CONCLUSION

This case report appears to indicate the possible carcinogenic potency of radiotherapy when administered many years before. A causal connection between the administration of whole body irradiation and the development of a mullerian mixed tumor cannot be established.

Atrial natriuretic factor (ANF) after laparoscopy and morphine application for pain therapy

OBJECTIVE

ANF is a potent diuretic, natriuretic and vasorelaxant hormone. The objective of the present study was to examine the effect of opioid receptor stimulation by morphine on endogenous ANF production and diuresis after surgery.

METHODS

Prospectively, nine women undergoing surgery for either uterine leiomyomas, chronic pelvic discomfort or desire for definitive contraception by laparoscopy were evaluated. Venous samples were collected at fixed times. Concentrations of ANF were measured by commercially available radioimmunassay test kits. Statistical analysis was performed by the Friedman Two-way ANOVA, Kruskal-Wallis 1-way ANOVA and Mann-Whitney U-Wilcoxon Rank Sum W Test. The level of significance was set at a probability below 0.05.

RESULTS

There were no statistically significant changes in serum levels of ANF (p = 0.98), in diastolic blood pressure (p = 0.14) or pain score (p = 0.86) after surgery. Systolic blood pressure (p = 0.0032), pulse rate (p = 0.019) and urinary flow rate (p < 0.0001) showed significant changes during observation.

CONCLUSION

Our results show that i.v. administered morphine induces a potent diuretic effect via activation of opioid receptors but it can not be suggested that this effect is due to an enhanced release of ANF.

Postpartum ovarian vein thrombosis

OBJECTIVE

Ovarian vein thrombosis (OVT) is known as a rare but serious postpartum complication. The condition is often clinically not distinguishable from endometritis, appendicitis or pyelonephritis. OVT may cause sepsis, septic pulmonary thromboembolism, and thrombosis of the inferior vena cava and the renal veins, and is potentially fatal. The objective of this study was to report the clinical findings and outcome of two patients with diagnosed ovarian vein thrombosis after delivery managed at this institution.

METHOD

Two patients fit the study criteria of documented ovarian vein thrombosis after delivery. An imaging diagnosis (CT) of ovarian vein thrombosis was required for final study inclusion.

RESULTS

We present two patients with ovarian vein thrombosis. The symptoms of one patient disappeared two days after beginning heparin and antibiotic therapy. The control-CT 93 days after the diagnosis of POVT showed unsuspected ovarian veins. The other patient suffered from POVT 13 days after spontaneous delivery. Because of lethal embolisms she died during the operation for embolectomy.

CONCLUSION

On the basis of our series and other recent series, OVT may likely be more common than previously thought and may become clinically apparent only when complicated by infection, expansion of the thrombus or pulmonary embolism. POVT is a potentially fatal condition most commonly seen as a complication of pelvic surgery or inflammatory disease.

Immunohistochemical evaluation of apoptosis in placentae from normal and intrauterine growth-restricted pregnancies

OBJECTIVE

To investigate the extent of apoptosis within the human placenta in tissues from normotensive term pregnancies and those complicated by intrauterine growth-restriction (IUGR).

METHODS

A total of 18 placentas, 10 obtained from uncomplicated term gestations and 8 from intrauterine growth restricted fetuses were included in this study. Apoptosis was identified using a terminal deoxynucleotidyl transferase-mediated deoxyuridine triophosphate nick end-labeling technique (TUNEL, Boehringer, Mannheim, Germany) in paraffin-embedded sections.

RESULTS

Apoptosis was predominantly detected in the villous trophoblast and stromal tissue. There were no differences in the incidence of apoptosis in different parts of the same placenta. The apoptotic index in placental tissue from uncomplicated pregnancies was 0.93 +/- 0.12. Significantly more apoptotic nuclei were detected in the placental tissue from IUGR gestation (4.2 +/- 2.96, p < 0.01).

CONCLUSION

These results might point toward a possible role of apoptosis in the pathophysiology of intrauterine growth-restriction.

Immunohistochemical analysis of DNA 'mismatch-repair' enzyme human Mut-S-Homologon-2 in ovarian carcinomas

The human Mut-S-Homologon-2 (hMSH-2) gene product is a member of a highly conserved family of proteins involved in postreplication mismatch repair. We have analysed hMSH-2 expression in normal ovarian tissue (n = 15) and ovarian carcinomas (n = 40). hMSH-2 protein was investigated immunohistochemically on frozen sections using a highly sensitive streptavidin-peroxidase technique and a specific mouse monoclonal antibody (clone FE11). A hMSH-2-immunoreactivity score (hMSH-2-IRS) for semiquantitative analysis of hMSH-2 expression is presented. In normal ovarian tissue, we only found weak nuclear immunoreactivity for hMSH-2 in 60%, while the remaining 40% were hMSH-2 negative (mean hMSH-2-IRS: 0.73; SD: +/-0.70). All ovarian carcinomas analysed revealed moderate to strong nuclear immunoreactivity (mean hMSH-2-IRS: 8.05; SD: +/-3.65). hMSH-2 staining was heterogeneous, with visual differences between individual tumour cells. Expression of hMSH-2 protein was consistently and strongly upregulated in tumour cells of ovarian carcinomas as compared to normal ovarian tissue. No statistically significant correlation in comparing the labelling patterns for hMSH-2 with the labelling patterns for Ki-67 (mean percentage of Ki-67 positive tumour cells: 25.88%; SD: +/-18.43) was observed in ovarian carcinomas. Furthermore, no statistical significant correlations between hMSH-2-IRS and histological grading (p = 0.47), histological type of carcinoma (p = 0.706) or FIGO-classification (p = 0.054) were found. Our findings indicate that (a) hMSH-2 is expressed in normal human ovarian tissue, (b) expression of hMSH-2 is increased in ovarian carcinomas, (c) expression of hMSH-2 may be of importance for the genetic stability of ovarian carcinomas in vivo, (d) hMSH-2 mutations may not cause microsatellite instability in ovarian carcinomas, (e) hMSH-2 may contribute to mechanisms responsible for resistance to anticancer drugs.

Immunohistochemical detection of apoptosis in the human term and post-term placenta

PURPOSE

To study the incidence of apoptosis in human term and post-term placenta and to determine its presence in different areas of placentas of uncomplicated pregnancies.

METHODS

A total of 15 placentas, 8 obtained from spontaneous deliveries and elective caesarean sections at term (37-41 weeks of pregnancy) and 7 from spontaneous deliveries and elective caesarean sections post-term (> 41 weeks of pregnancy) were included in this study. Apoptosis was identified by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling method (TUNEL, Boehringer, Mannheim, Germany) in paraffin-embedded sections.

RESULTS

Apoptosis was predominantly detected in trophoblast and stromal tissue. There were no significant differences in the incidence of apoptosis in different parts of placental tissue. A significant increase of apoptosis was seen in both trophoblast and stromal cells of post-term placentas (p < 0.05; p < 0.005).

CONCLUSIONS

Apoptosis could be detected in the human term and post-term placenta, with increasing incidence in post-term placental tissue, suggesting a possible role of apoptosis in the mechanism of parturition and placental senescence.

Immunohistochemical analysis of DNA mismatch-repair enzyme hMSH-2 and Ki-67 in breast carcinomas

BACKGROUND

The human Mut-S-Homologon-2 (hMSH-2) gene product is a member of a highly conserved family of proteins involved in postrepiclation mismatch repair.

MATERIALS AND METHODS

We have analyzed hMSH-2 expression in normal breast tissue (n = 10) and breast carcinomas (n = 30). hMSH-2 protein was investigated immunohistochemically on frozen sections using a specific mouse monoclonal antibody (clone FE11). hMSH-2 labelling pattern was compared with the staining pattern of the proliferation marker Ki-67. A hMSH-2-immunoreactivity score (hMSH-2-IRS) for the semiquantitative analysis of hMSH-2 expression is presented.

RESULTS

In normal breast tissue, we only found weak nuclear immunoreactivity for hMSH-2 in 70%, while the remaining 30% were hMSH-2 negative (mean hMSH-2- IRS: 1.00; SD: +/- 0.82). All breast carcinomas analyzed revealed moderate to strong nuclear immunoreactivity (mean hMSH-2-IRS: 7.67; SD: +/- 3.55). hMSH-2 staining was heterogeneous, with visual differences between individual tumour cells. Expression of hMSH-2 protein was consistently and strongly upregulated in tumour cells of breast carcinomas as compared to normal breast tissue. No visual correlation in comparing the labelling patterns for hMSH-2 with the labeliing patterns for Ki-67 (mean percentage of Ki-67 positive tumour cells: 24.33%; SD: +/- 15.35) was observed in breast carcinomas.

CONCLUSION

Our findings indicate that (a) hMSH-2 is expressed in normal human breast tissue; (b) expression of hMSH-2 may be of importance for the genetic stability of breast carcinomas in vivo.