Placenta-specific epimutation at H19-DMR among common pregnancy complications: its frequency and effect on the expression patterns of H19 and IGF2

Background

H19 and IGF2 genes are imprinted and involved in regulating fetal and placental growth. The H19 differentially methylated region (DMR) is paternally methylated and maternally unmethylated and regulates the imprinted expression of H19 and IGF2. Epimutation at the H19-DMR in humans results in congenital growth disorders, Beckwith-Wiedemann and Silver-Russell syndromes, when erroneously its maternal allele becomes methylated and its paternal allele becomes unmethylated, respectively. Although H19 and IGF2 have been assessed for their involvement in pregnancy complications including fetal growth restriction (FGR) and pregnancy-induced hypertension (PIH)/hypertensive disorder of pregnancy (HDP) intensively in the last decade, it is still not established whether epimutation at the H19-DMR in the placenta results in pathogenic conditions in pregnancy. We aimed to assess the frequency of H19-DMR epimutation and its effects on the allelic expression patterns of H19 and IGF2 genes among normal and abnormal pregnancy cases.

Results

We enrolled two independently collected sets of placenta samples from normal pregnancies as controls and common pregnancy complications, FGR and PIH (HDP). The first set consisted of 39 controls and 140 FGR and/or PIH cases, and the second set consisted of 29 controls and 62 cases. For these samples, we initially screened for DNA methylation changes at H19-DMR and IGF2-DMRs by combined bisulfite restriction analysis, and further analyzed cases with methylation changes for their allelic methylation and expression patterns. We identified one case each of FGR and PIH showing hypomethylation of H19-DMR and IGF2-DMRs only in the placenta, but not in cord blood, from the first case/control set. For the PIH case, we were able to determine the allelic expression pattern of H19 to be biallelically expressed and the H19/IGF2 expression ratio to be highly elevated compared to controls. We also identified a PIH case with hypomethylation at H19-DMR and IGF2-DMRs in the placenta from the second case/control set.

Conclusions

Placental epimutation at H19-DMR was observed among common pregnancy complication cases at the frequency of 1.5% (3 out of 202 cases examined), but not in 68 normal pregnancy cases examined. Alteration of H19/IGF2 expression patterns due to hypomethylation of H19-DMR may have been involved in the pathogenesis of pregnancy complications in these cases.

Electronic supplementary material

The online version of this article (10.1186/s13148-019-0712-3) contains supplementary material, which is available to authorized users.

Characterization of parent-of-origin methylation using the Illumina Infinium MethylationEPIC array platform

AIM

This study aimed to establish a catalog of probes corresponding to imprinted differentially methylated regions (DMRs) on the Infinium HumanMethylationEPIC BeadChip.

MATERIALS & METHODS

Reciprocal uniparental diploidies with low normal biparental mosaic contribution, together with normal diploid controls, were subjected to EPIC BeadChip hybridization. The methylation profiles were assessed for imprinted differential methylation. Top candidates were validated using locus-specific PCR-based assays.

RESULTS

Seven hundred and eighty-nine CpG probes coincided with 50 known imprinted DMRs and 467 CpG probes corresponding to 124 novel imprinted DMR candidates were identified. Validation led to identification of several subtle DMRs within known imprinted domains as well as novel maternally methylated regions associated with PTCHD3 and JAKMIP1.

CONCLUSION

Our comprehensive list of bona fide-imprinted DMR probes will simplify and facilitate methylation profiling of individuals with imprinting disorders and is applicable to other diseases in which aberrant imprinting has been implicated, such as cancer and fetal growth.

Human Oocyte-Derived Methylation Differences Persist in the Placenta Revealing Widespread Transient Imprinting

Thousands of regions in gametes have opposing methylation profiles that are largely resolved during the post-fertilization epigenetic reprogramming. However some specific sequences associated with imprinted loci survive this demethylation process. Here we present the data describing the fate of germline-derived methylation in humans. With the exception of a few known paternally methylated germline differentially methylated regions (DMRs) associated with known imprinted domains, we demonstrate that sperm-derived methylation is reprogrammed by the blastocyst stage of development. In contrast a large number of oocyte-derived methylation differences survive to the blastocyst stage and uniquely persist as transiently methylated DMRs only in the placenta. Furthermore, we demonstrate that this phenomenon is exclusive to primates, since no placenta-specific maternal methylation was observed in mouse. Utilizing single cell RNA-seq datasets from human preimplantation embryos we show that following embryonic genome activation the maternally methylated transient DMRs can orchestrate imprinted expression. However despite showing widespread imprinted expression of genes in placenta, allele-specific transcriptional profiling revealed that not all placenta-specific DMRs coordinate imprinted expression and that this maternal methylation may be absent in a minority of samples, suggestive of polymorphic imprinted methylation.

Differences in gamete DNA methylation is subject to genome-wide reprogramming during preimplantation development to establish an embryo with an epigenetic state compatible with totipotency. DNA sequences associated with imprinted differentially methylated regions (DMRs) are largely protected from this process, retaining their parent-of-origin epigenetic marks. By comparing the methylation profiles of human oocytes, sperm, blastocysts and various somatic tissues including placenta, we observe hundreds of CpG island sequences that maintain methylation on their maternal allele in blastocysts and placenta indicative of incomplete reprogramming. In some cases this maternal methylation influence transcription of nearby genes, revealing transient imprinting in embryos after genome-activation and in placenta. Strikingly, these placenta-specific DMRs are polymorphic between placenta samples with a minority of samples being robustly unmethylated on both alleles.

Absence of Maternal Methylation in Biparental Hydatidiform Moles from Women with NLRP7 Maternal-Effect Mutations Reveals Widespread Placenta-Specific Imprinting

Familial recurrent hydatidiform mole (RHM) is a maternal-effect autosomal recessive disorder usually associated with mutations of the NLRP7 gene. It is characterized by HM with excessive trophoblastic proliferation, which mimics the appearance of androgenetic molar conceptuses despite their diploid biparental constitution. It has been proposed that the phenotypes of both types of mole are associated with aberrant genomic imprinting. However no systematic analyses for imprinting defects have been reported. Here, we present the genome-wide methylation profiles of both spontaneous androgenetic and biparental NLRP7 defective molar tissues. We observe total paternalization of all ubiquitous and placenta-specific differentially methylated regions (DMRs) in four androgenetic moles; namely gain of methylation at paternally methylated loci and absence of methylation at maternally methylated regions. The methylation defects observed in five RHM biopsies from NLRP7 defective patients are restricted to lack-of-methylation at maternal DMRs. Surprisingly RHMs from two sisters with the same missense mutations, as well as consecutive RHMs from one affected female show subtle allelic methylation differences, suggesting inter-RHM variation. These epigenotypes are consistent with NLRP7 being a maternal-effect gene and involved in imprint acquisition in the oocyte. In addition, bioinformatic screening of the resulting methylation datasets identified over sixty loci with methylation profiles consistent with imprinting in the placenta, of which we confirm 22 as novel maternally methylated loci. These observations strongly suggest that the molar phenotypes are due to defective placenta-specific imprinting and over-expression of paternally expressed transcripts, highlighting that maternal-effect mutations of NLRP7 are associated with the most severe form of multi-locus imprinting defects in humans.

Imprinting control regions (ICRs) are marked by mono-allelic bivalent chromatin when transcriptionally inactive

Parental allele-specific expression of imprinted genes is mediated by imprinting control regions (ICRs) that are constitutively marked by DNA methylation imprints on the maternal or paternal allele. Mono-allelic DNA methylation is strictly required for the process of imprinting and has to be faithfully maintained during the entire life-span. While the regulation of DNA methylation itself is well understood, the mechanisms whereby the opposite allele remains unmethylated are unclear. Here, we show that in the mouse, at maternally methylated ICRs, the paternal allele, which is constitutively associated with H3K4me2/3, is marked by default by H3K27me3 when these ICRs are transcriptionally inactive, leading to the formation of a bivalent chromatin signature. Our data suggest that at ICRs, chromatin bivalency has a protective role by ensuring that DNA on the paternal allele remains unmethylated and protected against spurious and unscheduled gene expression. Moreover, they provide the proof of concept that, beside pluripotent cells, chromatin bivalency is the default state of transcriptionally inactive CpG island promoters, regardless of the developmental stage, thereby contributing to protect cell identity.

Integration of transcriptome and methylome analysis of aldosterone-producing adenomas

OBJECTIVE

The pathophysiology of aldosterone-producing adenomas (APA) has been investigated intensively through genetic and genomic approaches. However, the role of epigenetics in APA is not fully understood. In the present study, we explored the relationship between gene expression and DNA methylation status in APA.

METHODS

We conducted an integrated analysis of transcriptome and methylome data of paired APA-adjacent adrenal gland (AAG) samples from the same patient. The adrenal specimens were obtained from seven Japanese patients with APA who underwent adrenalectomy. Gene expression and genome-wide CpG methylation profiles were obtained from RNA and DNA samples that were extracted from those seven paired tissues.

RESULTS

Methylome analysis showed global CpG hypomethylation in APA relative to AAG. The integration of gene expression and methylation status showed that 34 genes were up-regulated with CpG hypomethylation in APA. Of these, three genes (CYP11B2, MC2R, and HPX) may be related to aldosterone production, and five genes (PRRX1, RAB38, FAP, GCNT2, and ASB4) are potentially involved in tumorigenesis.

CONCLUSION

The present study is the first methylome analysis to compare APA with AAG in the same patients. Our integrated analysis of transcriptome and methylome revealed DNA hypomethylation in APA and identified several up-regulated genes with DNA hypomethylation that may be involved in aldosterone production and tumorigenesis.

Genome-wide parent-of-origin DNA methylation analysis reveals the intricacies of human imprinting and suggests a germline methylation-independent mechanism of establishment

Differential methylation between the two alleles of a gene has been observed in imprinted regions, where the methylation of one allele occurs on a parent-of-origin basis, the inactive X-chromosome in females, and at those loci whose methylation is driven by genetic variants. We have extensively characterized imprinted methylation in a substantial range of normal human tissues, reciprocal genome-wide uniparental disomies, and hydatidiform moles, using a combination of whole-genome bisulfite sequencing and high-density methylation microarrays. This approach allowed us to define methylation profiles at known imprinted domains at base-pair resolution, as well as to identify 21 novel loci harboring parent-of-origin methylation, 15 of which are restricted to the placenta. We observe that the extent of imprinted differentially methylated regions (DMRs) is extremely similar between tissues, with the exception of the placenta. This extra-embryonic tissue often adopts a different methylation profile compared to somatic tissues. Further, we profiled all imprinted DMRs in sperm and embryonic stem cells derived from parthenogenetically activated oocytes, individual blastomeres, and blastocysts, in order to identify primary DMRs and reveal the extent of reprogramming during preimplantation development. Intriguingly, we find that in contrast to ubiquitous imprints, the majority of placenta-specific imprinted DMRs are unmethylated in sperm and all human embryonic stem cells. Therefore, placental-specific imprinting provides evidence for an inheritable epigenetic state that is independent of DNA methylation and the existence of a novel imprinting mechanism at these loci.

Molecular and clinical studies in 138 Japanese patients with Silver-Russell syndrome

Background

Recent studies have revealed relative frequency and characteristic phenotype of two major causative factors for Silver-Russell syndrome (SRS), i.e. epimutation of the H19-differentially methylated region (DMR) and uniparental maternal disomy 7 (upd(7)mat), as well as multilocus methylation abnormalities and positive correlation between methylation index and body and placental sizes in H19-DMR epimutation. Furthermore, rare genomic alterations have been found in a few of patients with idiopathic SRS. Here, we performed molecular and clinical findings in 138 Japanese SRS patients, and examined these matters.

Methodology/Principal Findings

We identified H19-DMR epimutation in cases 1–43 (group 1), upd(7)mat in cases 44–52 (group 2), and neither H19-DMR epimutation nor upd(7)mat in cases 53–138 (group 3). Multilocus analysis revealed hyper- or hypomethylated DMRs in 2.4% of examined DMRs in group 1; in particular, an extremely hypomethylated ARHI-DMR was identified in case 13. Oligonucleotide array comparative genomic hybridization identified a ∼3.86 Mb deletion at chromosome 17q24 in case 73. Epigenotype-phenotype analysis revealed that group 1 had more reduced birth length and weight, more preserved birth occipitofrontal circumference (OFC), more frequent body asymmetry and brachydactyly, and less frequent speech delay than group 2. The degree of placental hypoplasia was similar between the two groups. In group 1, the methylation index for the H19-DMR was positively correlated with birth length and weight, present height and weight, and placental weight, but with neither birth nor present OFC.

Conclusions/Significance

The results are grossly consistent with the previously reported data, although the frequency of epimutations is lower in the Japanese SRS patients than in the Western European SRS patients. Furthermore, the results provide useful information regarding placental hypoplasia in SRS, clinical phenotypes of the hypomethylated ARHI-DMR, and underlying causative factors for idiopathic SRS.

Methylation screening of reciprocal genome-wide UPDs identifies novel human-specific imprinted genes

Nuclear transfer experiments undertaken in the mid-80's revealed that both maternal and paternal genomes are necessary for normal development. This is due to genomic imprinting, an epigenetic mechanism that results in parent-of-origin monoallelic expression of genes regulated by germline-derived allelic methylation. To date, ∼100 imprinted transcripts have been identified in mouse, with approximately two-thirds showing conservation in humans. It is currently unknown how many imprinted genes are present in humans, and to what extent these transcripts exhibit human-specific imprinted expression. This is mainly due to the fact that the majority of screens for imprinted genes have been undertaken in mouse, with subsequent analysis of the human orthologues. Utilizing extremely rare reciprocal genome-wide uniparental disomy samples presenting with Beckwith-Wiedemann and Silver-Russell syndrome-like phenotypes, we analyzed ∼0.1% of CpG dinculeotides present in the human genome for imprinted differentially methylated regions (DMRs) using the Illumina Infinium methylation27 BeadChip microarray. This approach identified 15 imprinted DMRs associated with characterized imprinted domains, and confirmed the maternal methylation of the RB1 DMR. In addition, we discovered two novel DMRs, first, one maternally methylated region overlapping the FAM50B promoter CpG island, which results in paternal expression of this retrotransposon. Secondly, we found a paternally methylated, bidirectional repressor located between maternally expressed ZNF597 and NAT15 genes. These three genes are biallelically expressed in mice due to lack of differential methylation, suggesting that these genes have become imprinted after the divergence of mouse and humans.

Effect of large fundal varices on changes in gastric mucosal hemodynamics after endoscopic variceal ligation

BACKGROUNDS AND STUDY AIMS: Effect of endoscopic variceal ligation (EVL) on gastric mucosal hemodynamics would differ in patients with and without large fundal varices. The aim of this study was to test this hypothesis.

PATIENTS AND METHODS

Twenty-seven patients with cirrhosis and large sized esophageal varices were prospectively studied. There were eight patients with large fundal varices and 19 patients without large fundal varices. Before EVL, gastric mucosal hemodynamics were endoscopically assessed by laser-Doppler velocimetry and reflectance spectrophotometry in the antrum and the corpus. In the reflectance spectrophotometric measurements, gastric mucosal hemoglobin content (IHb) and gastric mucosal oxygen saturation (ISO2) were determined. The severity of portal-hypertensive gastropathy (PHG) was also recorded at the antrum and the corpus. For data analysis, PHG was scored (absent, 0; mild, 1; severe, 2; bleeding, 3). These measurements were repeated after initial (three days after initial session) and repeated (seven days after last session) EVL.

RESULTS

At the antrum, neither PHG score nor gastric mucosal hemodynamic parameters were modified after initial and repeated EVL in patients with and without large fundal varices. In addition, no significant differences of the integrated changes in PHG score and gastric mucosal hemodynamic parameters were observed in the two groups. At the corpus, PHG score significantly increased after initial and repeated EVL in patients without large fundal varices. In these patients, laser-Doppler signal and ISO2 significantly decreased and IHb significantly increased after initial and repeated EVL. In contrast, PHG score, laser-Doppler signal, and ISO2 did not change significantly in patients with large fundal varices, although IHb transiently increased after initial EVL. Furthermore, the integrated changes in PHG score and gastric mucosal hemodynamic parameters were significantly lower in patients with large fundal varices than in those without.

CONCLUSION

The aggravation of PHG after EVL is due to congestion of the gastric mucosal circulation. The presence of large fundal varices plays a protective role in the development of EVL-induced gastric mucosal hemodynamic derangement.

Splanchnic and extrasplanchnic arterial hemodynamics in patients with cirrhosis

BACKGROUND/AIMS

This study was designed to assess the contribution of splanchnic and extrasplanchnic vascular hemodynamics to the hyperdynamic circulation in patients with cirrhosis.

METHODS

Cardiac index and flow volume index and pulsatility index (PI) of superior mesenteric artery (SMA) and femoral artery (FA) were measured with Doppler ultrasonography in 40 controls and 86 patients with cirrhosis (Child-Pugh grade A=41, grade B=30, and grade C=15). Mean arterial pressure was also recorded to calculate systemic vascular resistance index.

RESULTS

Systemic vascular resistance index was significantly lower in each Child-Pugh group than in controls. SMA blood flow index was significantly higher in each Child-Pugh group than in controls and the increase in SMA blood flow index paralleled the degree of liver dysfunction. SMA-PI was significantly lower in each Child-Pugh group than in controls and the decrease in SMA-PI paralleled the degree of liver dysfunction. FA blood flow index was slightly higher in Child-Pugh grade A patients and significantly higher in grade B patients than in controls, whereas grade C patients had normal FA blood flow index. FA-PI was significantly lower in grade A and grade B patients than in controls, whereas grade C patients had normal FA-PI. When all patients were examined together, SMA-PI significantly correlated with systemic vascular resistance index (r=0.69, p<0.01). In contrast, FA-PI did not significantly correlate with systemic vascular resistance index (r=0.15, p=0.18).

CONCLUSIONS

Splanchnic arterial vasodilatation plays an important role in the pathogenesis of decreased systemic vascular resistance seen in patients with cirrhosis.

Effect of posture-induced blood volume expansion on systemic and regional hemodynamics in patients with cirrhosis

BACKGROUND/AIMS

This study aimed to investigate the effects of posture-induced blood volume expansion on systemic and regional hemodynamics in patients with cirrhosis.

METHODS

The mean arterial pressure, cardiac index, peripheral vascular resistance index, and flow volume index of the superior mesenteric artery (SMA) and femoral artery (FA) were measured in 10 patients with cirrhosis and portal hypertension and 10 controls after they had been standing for 2 h. Plasma atrial natriuretic peptide, plasma renin activity, and plasma glucagon levels were also determined. These measurements were repeated after 30 min and 60 min when the patients were recumbent.

RESULTS

In the upright posture, systemic hemodynamics, FA blood flow index, plasma atrial natriuretic peptide level, and plasma renin activity level were similar in patients and controls. However, SMA blood flow index and plasma glucagon level were significantly higher in patients than in controls. On the assumption of the supine position, cardiac index and plasma atrial natriuretic peptide level significantly increased in the two groups, but the changes were greater in patients than in controls. Mean arterial pressure remained unchanged. The reduction in peripheral vascular resistance index was therefore greater in patients in controls. SMA and FA blood flow index increased significantly in the two groups, but the changes were greater in patients than in controls. Furthermore, SMA blood flow fraction (SMA blood flow index/cardiac index) was steady in controls, whereas it increased significantly in patients. In contrast, FA blood flow fraction (FA blood flow index/cardiac index) remained unchanged in the two groups. In patients, the change in peripheral vascular resistance index was correlated inversely with that of SMA blood flow index, but not with that of FA blood flow index. Plasma renin activity level dropped significantly, but the decline was similar in the two groups. Plasma glucagon level was not modified in either group.

CONCLUSIONS

In patients with cirrhosis, splanchnic vasodilation appears to be present, even in the upright position, and further abnormal vasodilation occurs on recumbency-induced blood volume expansion. This abnormal shear-stress phenomenon observed in the splanchnic circulation seems to be mediated by a local vasodilator rather than a general vasodilator.

Value of Doppler ultrasound parameters of portal vein and hepatic artery in the diagnosis of cirrhosis and portal hypertension

OBJECTIVES

This prospective study was designed to assess the sensitivity and specificity of Doppler ultrasound parameters in the diagnosis of cirrhosis and portal hypertension.

METHODS

Portal and hepatic arterial Doppler ultrasound was performed on 76 patients with cirrhosis and esophageal varices and on 73 age- and sex-matched controls. The parameters evaluated were portal venous velocity and hepatic arterial pulsatility index. The liver vascular index was calculated as the ratio of portal venous velocity to hepatic arterial pulsatility index.

RESULTS

Portal venous velocity was significantly lower (11.0 +/- 2.4 vs 15.9 +/- 2.8 cm/s, p < 0.001) and hepatic arterial pulsatility index was significantly higher (1.28 +/- 0.18 vs 0.95 +/- 0.17,p < 0.001) in patients than in controls. Thus, the liver vascular index was significantly lower in patients than in controls (8.7 +/- 2.1 vs 17.2 +/- 4.3 cm/s, p < 0.001). The sensitivity and specificity of these parameters in the detection of cirrhosis and portal hypertension was then analyzed with the receiver operating characteristic curve. The best cut-off values were considered to be 13 cm/se of portal venous velocity and 1.1 of hepatic arterial pulsatility index, showing a sensitivity and specificity of 83, 85, 84, and 81%, respectively. The best cut-off value of the liver vascular index was 12 cm/s with a sensitivity and specificity of 97 and 93%, respectively.

CONCLUSIONS

The liver vascular index is a high sensitive and specific Doppler ultrasound parameter in the diagnosis of cirrhosis and portal hypertension.

Portal-hypertensive gastropathy develops less in patients with cirrhosis and fundal varices

BACKGROUND/AIMS

The aim of this prospective study was to examine the association of portal-hypertensive gastropathy and fundal varices in patients with cirrhosis.

METHODS

We carried out an endoscopic observation in 476 patients with cirrhosis (study 1), including 62 patients undergoing endoscopic obliteration of esophageal varices (study 2). In study 1, patients were classified into five subgroups: no esophagofundal varices (n=119), small esophagofundal varices (n=127), dominant esophageal varices (n=177), dominant fundal varices (n=27), and large esophagofundal varices (n=26). The severity of liver dysfunction was assessed by Pugh-Child classification: class A (n=222), class B (n=200), and class C (n=54). In study 2, two groups, poorly developed fundal varices (n=50) and well developed fundal (n=12), were distinguished and the follow-up endoscopic examinations were performed on the basis of 3-month intervals for 2 years. In each study, the severity of portal-hypertensive gastropathy was scored: 0 (absent), 1 (mild), 2 (severe), and 3 (bleeding).

RESULTS

Study 1: One-way ANOVA showed that both variceal pattern and Pugh-Child class significantly influenced portal-hypertensive gastropathy score. However, two-way ANOVA indicated that variceal pattern was the only significant variable. Portal-hypertensive gastropathy score was significantly higher in patients with dominant esophageal varices than in either patients with no esophagofundal varices or patients with small esophagofundal varices. In contrast, portal-hypertensive gastropathy score in patients with dominant fundal varices was similar to that in patients with no esophagofundal varices and was significantly lower compared with that in patients with dominant esophageal varices. Furthermore, portal-hypertensive gastropathy score was significantly lower in patients with large esophagofundal varices than in patients with dominant esophageal varices. Study 2: After the obliteration of esophageal varices, portal-hypertensive gastropathy score in patients with poorly developed fundal varices became significantly higher at 3-, 6-, 9-months while it was not modified in patients with well developed fundal varices during the follow-up period. Furthermore, the integrated incremental change in portal-hypertensive gastropathy score during the first 1-year follow-up period was significantly lower in patients with well developed fundal varices than in patients with poorly developed fundal varices.

CONCLUSIONS

These results indicate that both spontaneous and obliteration-induced portal-hypertensive gastropathy lesions develop less in patients with cirrhosis and fundal varices.

Postprandial splanchnic hemodynamic response in patients with cirrhosis of the liver: evaluation with "triple-vessel" duplex US

PURPOSE

To investigate the effect of a meal on splanchnic circulation in patients with cirrhosis of the liver.

MATERIALS AND METHODS

Ten adult patients with cirrhosis and 10 adult control subjects (mean age, 54 years) underwent duplex ultrasonography. Flow volumes of the portal vein, superior mesenteric artery, splenic artery, and collateral vessels (difference between the splanchnic inflow [the sum of the superior mesenteric arterial and the splenic arterial blood flows] and the portal venous blood flow) were measured before and after a meal every 15 minutes for 60 minutes. Integrated post-prandial changes (the sum of the changes at each time point) were also calculated.

RESULTS

Portal venous blood flow increased after the meal in control subjects (P < .01) and patients (P < .01). The integrated postprandial change in the portal venous blood flow was lower in patients than in control subjects (P < .05). Superior mesenteric arterial blood flow increased after the meal in control subjects (P < .01) and patients (P < .01); the integrated postprandial change in the superior mesenteric arterial blood flow was similar. In the two groups, splenic arterial blood flow remained unchanged after the meal. Collateral blood flow increased after the meal in patients (P < .01).

CONCLUSION

Postprandial portal hyperemia is mainly due to mesenteric arterial vasodilation; reduced postprandial portal hyperemia in patients with cirrhosis is attributable to portocollateral runoff.

Effect of vasopressin on esophageal varices blood flow in patients with cirrhosis: comparisons with the effects on portal vein and superior mesenteric artery blood flow

BACKGROUND/AIMS

Vasopressin reduces portal pressure which may be due to decreased portal inflow. However, it remains unclear whether vasopressin is able to selectively reduce esophageal varices blood flow. The aim of this study was to address this question.

METHODS

Fifteen patients with cirrhosis and esophageal varices were included in this prospective study. Portal vein and superior mesenteric artery flow velocity were measured with a percutaneous echo-Doppler. Esophageal varices flow velocity was measured using a transesophageal echo-Doppler technique. Mean arterial pressure and heart rate were also recorded. These measurements were performed at baseline condition and 15 min after observer blind drug administration. In this study, two groups, six patients receiving placebo and nine patients receiving 0.3 U/min of vasopressin, were randomized according to the coded number.

RESULTS

Placebo administration had no effect on systemic and splanchnic circulation. In contrast, vasopressin administration increased mean arterial pressure (p < 0.05) associated with a bradycardia (p < 0.01). In splanchnic circulation, vasopressin decreased portal vein (-32 +/- 3%, p < 0.01), superior mesenteric artery (-30 +/- 2%, p < 0.01), and esophageal varices flow velocity (-48 +/- 5%, p < 0.01). When the magnitude of these reductions was compared, ANOVA showed a significant difference (p < 0.01). Furthermore, the reduction in esophageal varices flow velocity was significantly higher than that in portal vein flow velocity (p < 0.01) and that in superior mesenteric artery flow velocity (p < 0.01).

CONCLUSIONS

These data support the view that vasopressin is able to selectively reduce esophageal varices blood flow. This effect, in addition to its well-established portal pressure reducing action, may play a role in its therapeutic efficacy in the treatment of variceal bleeding.

Hepatic artery hemodynamic responsiveness to altered portal blood flow in normal and cirrhotic livers

PURPOSE

To compare hepatic artery hemodynamic response to altered portal blood flow in normal and cirrhotic livers.

MATERIALS AND METHODS

The portal blood flow and hepatic artery pulsatility index were measured by means of duplex ultrasound before and after subjects (eight control subjects and 10 cirrhotic patients) ingested a 500-kcal mixed-liquid meal and during intravenous infusion of vasopressin at a rate of 0.3 U/min (nine control and nine cirrhotic subjects). The hepatic artery buffer index (ratio of maximum change from baseline in hepatic artery pulsatility index to maximum change from baseline in portal blood flow) was also calculated.

RESULTS

Meal consumption increased the portal blood flow and hepatic artery pulsatility index in all subjects. The hepatic artery buffer index, however, was significantly lower in cirrhotic than in control subjects (0.67 min/L +/- 0.06 [standard error of the mean] vs 1.54 min/L +/- 0.20, respectively; P < .01). Vasopressin infusion decreased the portal blood flow and hepatic artery pulsatility index in all subjects. Again, the hepatic artery buffer index was significantly lower in cirrhotic than in control subjects (0.28 min/L +/- 0.07 vs 0.50 min/L +/- 0.04, respectively; P < .05).

CONCLUSION

Hepatic artery vascular responsiveness to altered portal blood flow is blunted in cirrhotic livers.

Serial serum determination on alpha-fetoprotein as a marker of the effect of postoperative chemotherapy in ovarian endodermal sinus tumor

Serial serum determinations of alpha-fetoprotein (alpha FP) as a tumor marker were carried out in the management of six patients with endodermal sinus tumor (EST). Histological examinations in all six patients revealed a typical EST pattern, and in one of them another germ cell tumor, a malignant teratoma, was also found. All patients were treated postoperatively with combination chemotherapy. The serum alpha FP concentrations before treatment, using radioimmunoassay, were abnormally high and ranged from 2500 to 100,000 ng/ml. One patient having Stage Ia neoplasm is living at 50 months after diagnosis with a normal alpha FP concentration and without clinical evidence of recurrence. The other five patients with Stage III disease died from 4 to 9 months after surgery, respectively, although the serum alpha FP in all these cases during chemotherapy decreased markedly but temporarily to a normal level (less than 20 ng/ml) or to 3000 ng/ml and was paralleled by a certain improvement in the conditions of the disease. These results suggest that serial serum determination of alpha FP may be useful as a marker and prognostic indicator of endodermal sinus tumor.

Unconjugated estradiol, estriol and total estriol in maternal peripheral vein, cord vein, and cord artery serum at delivery in pregnancies with intrauterine growth retardation

The levels of unconjugated estradiol (E2), estriol (E3) and total (conjugated plus unconjugated) E3 in maternal vein serum during labor, cord vein serum, and cord artery serum were measured in normal singleton and twin pregnancies with appropriate for dates babies (AFD) and with light for dates babies (LFD). The mean level of total E3 in the maternal vein serum in singleton pregnancy was significantly lower in the LFD group than in the AFD group, but no differences were seen in the mean levels of unconjugated E2 or E3 between the groups. The concentration of unconjugated E2 in the maternal vein serum was significantly higher in the twin group with a large placenta than in the singleton group with a smaller placenta, while the concentration of total E3 in the case of twin pregnancy with LFD was lower than that in singleton pregnancy with AFD but not significantly. No difference in the concentration of total E3 was observed between the cord vein serum and cord artery serum. The present data suggest that the total E3 level in maternal vein serum may be used in evaluating fetal states such as intrauterine growth retardation.

Effect of ACTH infusion on induction of uterine contraction in prolonged human pregnancy in association with endocrine function

The role of hormonal interactions in the mechanism initiating labor in women was studied. The serum levels in women was studied. The serum levels of cortisol, progesterone, estradiol estriol, human chorionic somatomammotropin, and prolactin were measured simultaneously before, during and after infusion of ACTH at a rate of 50 microgram/h in 100 ml of physiological saline or infusion of physiological saline without ACTH (as control) at a rate of 100 ml/h into 14 pregnant women of 10 days or more beyond term. In five (group A) of the 10 women infused with ACTH. uterine contractions were induced within 5-15 min after beginning of ACTH infusion. Although the serum progesterone levels in group A were slightly, but not significantly, lower than those in the other five women (group B) in whom uterine contractions were not induced, the ratio of progesterone to estriol was 13/1 in group A and 18/1 in group B, respectively (P less than 0.05). The endocrine levels in group A may be favorable for the initiation of uterine contraction. The serum cortisol levels in group A were higher, but not significantly higher, than those in group B after ACTH infusion. And the serum estriol levels 6 h after ACTH infusion were significantly lower than control levels before ACTH infusion (P less than 0.01 in group A, P less than 0.05 in group B). To the contrast, in all the four control women infused with physiological saline only (group C), neither uterine contractions nor changes in the serum levels of ACTH and cortisol were found. This work may show that ACTH infusion induced uterine contractions by increased corticosteroids via placenta in lower ratio of progesterone to estrogen but it does not provide any precise information on the mechanism of initiation of human labor.