Cloning and pattern of expression of the shiro-uo vasa gene during embryogenesis and its roles in PGC development.

PubMed

Miyake, Akimitsu; Saito, Taiju; Kashiwagi, Noboru; Ando, Daisuke; Yamamoto, Akitsugu; Suzuki, Tohru; Nakatsuji, Norio; Nakatsuji, Takako

2006-01-01

The vasa genes are expressed in the germ cell lineage in many organisms, but their expression patterns show large variations. Recent studies suggest that vasa transcripts are involved in germ cell lineage development. In this paper, we isolated the vasa cDNA clone from a teleost, shiro-uo, Leucopsarion petersii and examined its expression pattern during embryogenesis. Then, we examined the functional significance of vasa mRNA during the formation of primordial germ cells (PGCs). The amino acid sequence of shiro-uo VASA is 61.1% identical to that of zebrafish. In whole-mount in situ hybridization, vasa transcripts appeared at the 4- and 8-cell stages as four spots at both ends of two cleavage planes between the lower tier of blastomeres and the yolk cell mass. At the 16-cell stage, eight spots were observed. After the blastula stage, shiro-uo vasa transcripts showed similar localization as in the zebrafish. Ultrastructural analysis of 4-cell stage embryos revealed the presence of a subcellular organelle that resembled 'nuage' in the germ cell lineage observed in the embryos of various organisms. We carried out micromanipulation of 4- or 8-cell stage embryos to remove the vasa mRNA-containing spots and then measured the number of the vasa-expressing PGCs in the genital ridge of the manipulated embryos. The numbers decreased when all of the four spots were removed, indicating that the vasa-containing spots at early cleavage stages have important functions in the development of PGCs.

Isolation and characterization of Vasa in the frog Rana rugosa.

PubMed

Saotome, Kazuhiro; Hayashi, Kota; Adachi, Noritaka; Nakamura, Yoriko; Nakamura, Masahisa

2010-08-01

We cloned a cDNA encoding Vasa, a member of the DEAD (Asp-Glu-Ala-Asp) family of proteins, from the ovary of the frog Rana rugosa. Comparative alignment of amino acid sequences with known Vasa from several species of vertebrate showed that the R. rugosa orthologue shares eight conserved regions with Vasa from other vertebrates. Vasa gene expression was restricted to the testis and ovary among ten different tissues examined. Vasa expression showed no sexual dimorphism during sex determination in R. rugosa, but became higher in the ovary thereafter. By Western blot analysis, a single Vasa band with a molecular weight of 80.9 kDa was detected. The same antibody immunohistochemically detected Vasa in a few cells in the embryonic endoderm at stage 15; the beginning of closure of neural folds, and in the cytoplasm of spermatogonia in the testis, and oocytes in the ovary of tadpoles at stage XX; marked by one or both forelegs protruded. Together, these results suggest that Vasa is a highly specific marker of germ cells and hence useful for studies of germ cell specification and function in amphibians as it already is in other species of both invertebrates and vertebrates such as Drosophila and zebrafish. (c) 2010 Wiley-Liss, Inc.

Reliability, validity and sensitivity of a computerized visual analog scale measuring state anxiety.

PubMed

Abend, Rany; Dan, Orrie; Maoz, Keren; Raz, Sivan; Bar-Haim, Yair

2014-12-01

Assessment of state anxiety is frequently required in clinical and research settings, but its measurement using standard multi-item inventories entails practical challenges. Such inventories are increasingly complemented by paper-and-pencil, single-item visual analog scales measuring state anxiety (VAS-A), which allow rapid assessment of current anxiety states. Computerized versions of VAS-A offer additional advantages, including facilitated and accurate data collection and analysis, and applicability to computer-based protocols. Here, we establish the psychometric properties of a computerized VAS-A. Experiment 1 assessed the reliability, convergent validity, and discriminant validity of the computerized VAS-A in a non-selected sample. Experiment 2 assessed its sensitivity to increase in state anxiety following social stress induction, in participants with high levels of social anxiety. Experiment 1 demonstrated the computerized VAS-A's test-retest reliability (r = .44, p < .001); convergent validity with the State-Trait Anxiety Inventory's state subscale (STAI-State; r = .60, p < .001); and discriminant validity as indicated by significantly lower correlations between VAS-A and different psychological measures relative to the correlation between VAS-A and STAI-State. Experiment 2 demonstrated the VAS-A's sensitivity to changes in state anxiety via a significant pre- to during-stressor rise in VAS-A scores (F(1,48) = 25.13, p < .001). Set-order administration of measures, absence of clinically-anxious population, and gender-unbalanced samples. The adequate psychometric characteristics, combined with simple and rapid administration, make the computerized VAS-A a valuable self-rating tool for state anxiety. It may prove particularly useful for clinical and research settings where multi-item inventories are less applicable, including computer-based treatment and assessment protocols. The VAS-A is freely available: http://people.socsci.tau.ac.il/mu/anxietytrauma/visual-analog-scale/. Copyright © 2014 Elsevier Ltd. All rights reserved.

Radial Modulation Contrast Imaging Using a 20-MHz Single-Element Intravascular Ultrasound Catheter

PubMed Central

Yu, Francois T. H.; Villanueva, Flordeliza S.; Chen, Xucai

2014-01-01

Contrast-enhanced intravascular ultrasound imaging is a promising tool for the characterization of coronary vasa vasorum proliferation, which has been identified as a marker of, and possible etiologic factor in, the development of high-risk atherosclerotic plaques. Resonance-based nonlinear detection methods have required the development of prototype catheters which are not commercially available, thus limiting clinical translation. In this study, we investigated the performances of a radial modulation imaging approach (25/3 MHz combination) using simulations, implemented it on a clinical 20-MHz rotating catheter, and tested it in a wall-less tissue-mimicking flow phantom perfused with lipid-encapsulated microbubbles (MBs). The effects of the phase lag, low-frequency pressure, and MB concentration on the envelope subtracted radial modulation signals were investigated as a function of depth. Our dual-pulse dual-frequency approach produced contrast-specific images with contrast-to-tissue improvements over B-mode of 15.1 ± 2.1 dB at 2 mm and 6.8 ± 0.1 dB at 4 mm depths. Using this imaging strategy, 200-μm-diameter cellulose tubing perfused with MBs could be resolved while surrounding tissue scattering was suppressed. These results raise promise for the detection of coronary vasa vasorum and may ultimately facilitate the detection of plaque at risk for rupture. PMID:24803134

Vasa Vasorum Arteriopathy: Relationship With Systemic Arterial Hypertension and Other Vascular Lesions in Cats.

PubMed

Kohnken, R; Scansen, B A; Premanandan, C

2017-05-01

The vasa vasorum is a delicate network of small arterioles that supplies nutrients to the adventitia and outer media of large arteries. In humans, dysfunction of the vasa vasorum contributes to the pathogenesis of aortic dissection and atherosclerosis. Twenty-four cats from 1 to 18 years of age were prospectively evaluated. Cases were divided into 3 cohorts-with systemic hypertension, without systemic hypertension, and uncertain. Histologic sections of the aorta and main pulmonary artery, as well as sections of kidney and lung, were blindly examined by 2 pathologists. The severity of vasa vasorum arteriopathy was compared to the presence of renal arteriosclerosis, aortic medial degeneration, subintimal fibroplasia of the main pulmonary artery, and blood pressure. We found that vasa vasorum arteriopathy correlated strongly with hypertensive status, degree of renal arteriosclerosis, and lesions in the great vessels. The positive predictive value of a severe vasa vasorum score for systemic hypertension was 84.6%. Lesions of vasa vasorum arteriopathy were predictive of renal arteriosclerosis with 100% sensitivity and 64.7% specificity. The positive predictive value of a severe vasa vasorum score for the presence of aortic lesions was 69.2% vs 91.6% for lesions in the main pulmonary artery. The vasa vasorum appears to be an important responder to systemic hypertension in cats, and arteriopathy of this vascular bed has significant implications for the integrity of the great vessels.

Circular DNA Intermediate in the Duplication of Nile Tilapia vasa Genes

PubMed Central

Fujimura, Koji; Conte, Matthew A.; Kocher, Thomas D.

2011-01-01

vasa is a highly conserved RNA helicase involved in animal germ cell development. Among vertebrate species, it is typically present as a single copy per genome. Here we report the isolation and sequencing of BAC clones for Nile tilapia vasa genes. Contrary to a previous report that Nile tilapia have a single copy of the vasa gene, we find evidence for at least three vasa gene loci. The vasa gene locus was duplicated from the original site and integrated into two distant novel sites. For one of these insertions we find evidence that the duplication was mediated by a circular DNA intermediate. This mechanism of gene duplication may explain the origin of isolated gene duplicates during the evolution of fish genomes. These data provide a foundation for studying the role of multiple vasa genes in the development of tilapia gonads, and will contribute to investigations of the molecular mechanisms of sex determination and evolution in cichlid fishes. PMID:22216289

Identification and Migration of Primordial Germ Cells in Atlantic Salmon, Salmo salar: Characterization of Vasa, Dead End, and Lymphocyte Antigen 75 Genes

PubMed Central

Nagasawa, Kazue; Fernandes, Jorge MO; Yoshizaki, Goro; Miwa, Misako; Babiak, Igor

2013-01-01

No information exists on the identification of primordial germ cells (PGCs) in the super-order Protacanthopterygii, which includes the Salmonidae family and Atlantic salmon (Salmo salar L.), one of the most commercially important aquatic animals worldwide. In order to identify salmon PGCs, we cloned the full-length cDNA of vasa, dead end (dnd), and lymphocyte antigen 75 (ly75/CD205) genes as germ cell marker candidates, and analyzed their expression patterns in both adult and embryonic stages of Atlantic salmon. Semi-quantitative RT-PCR results showed that salmon vasa and dnd were specifically expressed in testis and ovary, and vasa, dnd, and ly75 mRNA were maternally deposited in the egg. vasa mRNA was consistently detected throughout embryogenesis while dnd and ly75 mRNA were gradually degraded during cleavages. In situ analysis revealed the localization of vasa and dnd mRNA and Ly75 protein in PGCs of hatched larvae. Whole-mount in situ hybridization detected vasa mRNA during embryogenesis, showing a distribution pattern somewhat different to that of zebrafish; specifically, at mid-blastula stage, vasa-expressing cells were randomly distributed at the central part of blastodisc, and then they migrated to the presumptive region of embryonic shield. Therefore, the typical vasa localization pattern of four clusters during blastulation, as found in zebrafish, was not present in Atlantic salmon. In addition, salmon PGCs could be specifically labeled with a green fluorescence protein (GFP) using gfp-rt-vasa 3′-UTR RNA microinjection for further applications. These findings may assist in understanding PGC development not only in Atlantic salmon but also in other salmonids. PMID:23239145

Hypertrophy of the vasa vasorum: vascular response to the hungry brain.

PubMed

Cho, Hyun-Ji; Roh, Hong Gee; Chun, Young Il; Moon, Chang Taek; Chung, Hyun Woo; Kim, Hahn Young

2012-05-01

The vasa vasorum is a network of microvessels that supplies nutrients to the vessel wall itself. In pathologic conditions, the vasa vasorum can develop as potential collateral channels. Previous research documents revascularization through hypertrophy of the vasa vasorum after occlusion of the carotid artery. However, the relationship between the cerebral vascular demands and the hypertrophy of the vasa vasorum has not been well delineated by functional studies. A 66-year-old man presented with left hemiparesis, dysarthria, and hemineglect. Magnetic resonance imaging revealed an acute infarction in the vascular territory of the right middle cerebral artery. Transfemoral cerebral angiography revealed occlusion of the right proximal internal carotid artery (ICA). Single-photon emission computed tomography study showed decreased vascular reserve in the right cerebral hemisphere. Right superficial temporal artery-middle cerebral artery bypass surgery was performed in an attempt to improve hemispheric perfusion. Follow-up angiography 1 year later showed revascularization of the distal ICA by the hypertrophied vasa vasorum. Follow-up single-photon emission computed tomography study showed persistent decreased vascular reserve. In cases of ICA occlusion, a 1-year or less hungry period for the cerebral vascular demand may activate potential collateral channels of the vasa vasorum. In addition to the metabolic demand of the occluded vessel wall itself, the vascular demands of the hypoperfused brain may be a trigger factor that leads to hypertrophy of the vasa vasorum as collateral channels.

Sperm reflux and its role in multiple mating in males of a butterfly Polygonia c-aureum Linnaeus (Lepidoptera: Nymphalidae).

PubMed

Hiroyoshi, S; Mitsuhashi, J

1999-02-01

The relationship between sperm quantity in the duplex and that in the vasa deferentia was examined in the Asian comma butterfly, Polygonia c-aureum. In virgin males, the number of eupyrene sperm bundles in the duplex increased linearly with age, whereas that in the vasa deferentia was consistently small. However, numerous sperm were found in the vasa deferentia of males immediately after mating. The number of eupyrene sperm bundles in the vasa deferentia after mating significantly increased with age and with increasing the time interval between matings. From these and other results, it was suggested that some sperm in the duplex were moved back to the vasa deferentia during mating, and that such sperm reflux provides a means to save sperm for multiple mating.

A Novel Dynamic Expression of vasa in Male Germ Cells during Spermatogenesis in the Chinese Soft-Shell Turtle (Pelidiscus sinensis).

PubMed

Li, Wei; Zhang, Piaoyi; Wu, Xuling; Zhu, Xinping; Xu, Hongyan

2017-05-01

vasa gene encodes a highly conserved DEAD-box RNA helicase, required for germ cell development across animal kingdom. Vasa mutations cause male infertility in mammals. It has been widely used as a biomarker for studying animal fertility or manipulating germ cells in organisms. However, in reptilians, the functions of vasa gene involved in germ cell differentiation are largely unclear; this hampers the development of biological techniques and the improvement of the productivity in these species. Here a vasa cDNA was isolated in Chinese soft-shell turtle and it predicts a protein of 691 amino acid residues, which is 72%, 69%, 58%, 59%, and 54-56% identical to its homolog from mouse, platypus, frog, chicken, and fish, respectively, and named as PsVasa. The Psvasa mRNA was detected exclusively in the gonads of both sexes by RT-PCR. Chromogenic RNA in situ hybridization revealed that the Psvasa mRNA was restricted to germ cells in the testis: The psvasa mRNA is undetectable in resting spermatogonia, appears in proliferating spermatogonia, and becomes abundant in spermatocytes and detectable in spermatozoa. Immunofluorescence staining demonstrated that the PsVasa in the testis is also restricted to the germ cells, rich in spermatocytes and elongated spermatids but hardly detectable in spermatogonia and spermatozoa. Taken together, Psvasa is potentially a reliable germ cell marker in the Chinese soft-shell turtle; its RNA expression could distinguish the different spermatogenic stages of germ cells. These findings shed new insights into understanding the evolutionary conservations and divergences of vasa gene's functions in male germ cell differentiation in metazoans. © 2017 Wiley Periodicals, Inc.

A novel form of spontaneous tool use displayed by several captive greater vasa parrots (Coracopsis vasa).

PubMed

Lambert, Megan L; Seed, Amanda M; Slocombe, Katie E

2015-12-01

Parrots are frequently cited for their sophisticated problem-solving abilities, but cases of habitual tool use among psittacines are scarce. We report the first evidence, to our knowledge, of tool use by greater vasa parrots (Coracopsis vasa). Several members of a captive population spontaneously adopted a novel tool-using technique by using pebbles and date pits either (i) to scrape on the inner surface of seashells, subsequently licking the resulting calcium powder from the tool, or (ii) as a wedge to break off smaller pieces of the shell for ingestion. Tool use occurred most frequently just prior to the breeding season, during which time numerous instances of tool transfer were also documented. These observations provide new insights into the tool-using capabilities of parrots and highlight the greater vasa parrot as a species of interest for studies of physical cognition. © 2015 The Author(s).

Placenta previa with early opening of the uterine isthmus is associated with high risk of bleeding during pregnancy, and massive haemorrhage during caesarean delivery.

PubMed

Goto, M; Hasegawa, J; Arakaki, T; Takita, H; Oba, T; Nakamura, M; Sekizawa, A

2016-06-01

To demonstrate the relationship between the timing of opening of the uterine isthmus and bleeding during pregnancy and caesarean section in patients with placenta previa. A prospective observational study was conducted at a single perinatal centre. All patients with placenta previa, diagnosed between 20 and 22 weeks of gestation, who were followed up at the study hospital and underwent caesarean section were enrolled. The condition of the uterine isthmus was examined every 2 weeks. The timing (in gestational weeks) of complete opening of the uterine isthmus was determined. Patients were divided into two groups: patients in whom the uterine isthmus opened before 25 weeks of gestation (EO-previa), and patients in whom the uterine isthmus opened after 25 weeks of gestation (LO-previa). The frequency of bleeding during pregnancy and the amount of intra-operative bleeding were compared between the two groups. Forty-four cases of EO-previa and 55 cases of LO-previa were analysed. Complete placenta previa at delivery was observed more frequently in the EO-previa group than in the LO-previa group (88.6% vs 47.3%, p<0.001). An emergency caesarean section due to active bleeding was performed more frequently in the EO-previa group (48%) than in the LO-previa group (25%) (p=0.021). The frequency of massive haemorrage (>2500ml) during caesarean section was higher in the EO-previa group than in the LO-previa group (25% vs 9%, p=0.033). Placenta previa was associated with a high risk of bleeding leading to emergency caesarean section during pregnancy, and massive haemorrhage during caesarean section in patients in whom the uterine isthmus opened before 25 weeks of gestation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Type and location of placenta previa affect preterm delivery risk related to antepartum hemorrhage.

PubMed

Sekiguchi, Atsuko; Nakai, Akihito; Kawabata, Ikuno; Hayashi, Masako; Takeshita, Toshiyuki

2013-01-01

To evaluate whether type and location of placenta previa affect risk of antepartum hemorrhage-related preterm delivery. We retrospectively studied 162 women with singleton pregnancies presenting placenta previa. Through observation using transvaginal ultrasound the women were categorized into complete or incomplete placenta previa, and then assigned to anterior and posterior groups. Complete placenta previa was defined as a placenta that completely covered the internal cervical os, with the placental margin >2 cm from the os. Incomplete placenta previa comprised marginal placenta previa whose margin adjacent to the internal os and partial placenta previa which covered the os but the margin situated within 2 cm of the os. Maternal characteristics and perinatal outcomes in complete and incomplete placenta previa were compared, and the differences between the anterior and the posterior groups were evaluated. Antepartum hemorrhage was more prevalent in women with complete placenta previa than in those with incomplete placenta previa (59.1% versus 17.6%), resulting in the higher incidence of preterm delivery in women with complete than in those with incomplete placenta previa [45.1% versus 8.8%; odds ratio (OR) 8.51; 95% confidence interval (CI) 3.59-20.18; p < 0.001]. In complete placenta previa, incidence of antepartum hemorrhage did not significantly differ between the anterior and the posterior groups. However, gestational age at bleeding onset was lower in the anterior group than in the posterior group, and the incidence of preterm delivery was higher in the anterior group than in the posterior group (76.2% versus 32.0%; OR 6.8; 95% CI 2.12-21.84; p = 0.002). In incomplete placenta previa, gestational age at delivery did not significantly differ between the anterior and posterior groups. Obstetricians should be aware of the increased risk of preterm delivery related to antepartum hemorrhage in women with complete placenta previa, particularly when the placenta is located on the anterior wall.

Type and Location of Placenta Previa Affect Preterm Delivery Risk Related to Antepartum Hemorrhage

PubMed Central

Sekiguchi, Atsuko; Nakai, Akihito; Kawabata, Ikuno; Hayashi, Masako; Takeshita, Toshiyuki

2013-01-01

Purpose: To evaluate whether type and location of placenta previa affect risk of antepartum hemorrhage-related preterm delivery. Methods: We retrospectively studied 162 women with singleton pregnancies presenting placenta previa. Through observation using transvaginal ultrasound the women were categorized into complete or incomplete placenta previa, and then assigned to anterior and posterior groups. Complete placenta previa was defined as a placenta that completely covered the internal cervical os, with the placental margin >2 cm from the os. Incomplete placenta previa comprised marginal placenta previa whose margin adjacent to the internal os and partial placenta previa which covered the os but the margin situated within 2 cm of the os. Maternal characteristics and perinatal outcomes in complete and incomplete placenta previa were compared, and the differences between the anterior and the posterior groups were evaluated. Results: Antepartum hemorrhage was more prevalent in women with complete placenta previa than in those with incomplete placenta previa (59.1% versus 17.6%), resulting in the higher incidence of preterm delivery in women with complete than in those with incomplete placenta previa [45.1% versus 8.8%; odds ratio (OR) 8.51; 95% confidence interval (CI) 3.59-20.18; p < 0.001]. In complete placenta previa, incidence of antepartum hemorrhage did not significantly differ between the anterior and the posterior groups. However, gestational age at bleeding onset was lower in the anterior group than in the posterior group, and the incidence of preterm delivery was higher in the anterior group than in the posterior group (76.2% versus 32.0%; OR 6.8; 95% CI 2.12-21.84; p = 0.002). In incomplete placenta previa, gestational age at delivery did not significantly differ between the anterior and posterior groups. Conclusion: Obstetricians should be aware of the increased risk of preterm delivery related to antepartum hemorrhage in women with complete placenta previa, particularly when the placenta is located on the anterior wall. PMID:24151440

The LOTUS domain is a conserved DEAD-box RNA helicase regulator essential for the recruitment of Vasa to the germ plasm and nuage

PubMed Central

Jeske, Mandy; Müller, Christoph W.; Ephrussi, Anne

2017-01-01

DEAD-box RNA helicases play important roles in a wide range of metabolic processes. Regulatory proteins can stimulate or block the activity of DEAD-box helicases. Here, we show that LOTUS (Limkain, Oskar, and Tudor containing proteins 5 and 7) domains present in the germline proteins Oskar, TDRD5 (Tudor domain-containing 5), and TDRD7 bind and stimulate the germline-specific DEAD-box RNA helicase Vasa. Our crystal structure of the LOTUS domain of Oskar in complex with the C-terminal RecA-like domain of Vasa reveals that the LOTUS domain occupies a surface on a DEAD-box helicase not implicated previously in the regulation of the enzyme's activity. We show that, in vivo, the localization of Drosophila Vasa to the nuage and germ plasm depends on its interaction with LOTUS domain proteins. The binding and stimulation of Vasa DEAD-box helicases by LOTUS domains are widely conserved. PMID:28536148

Assessment of Fetal Myocardial Performance Index in Women with Placenta Previa.

PubMed

Zhang, Na; Sun, Lijuan; Zhang, Lina; Li, Zhen; Han, Jijing; Wu, Qingqing

2017-12-15

BACKGROUND This study investigated whether fetuses of placenta previa pregnancies have cardiac dysfunction by use of a modified myocardial performance index (Mod-MPI). MATERIAL AND METHODS A prospective cross-sectional study was conducted including 178 fetuses at 28-40 weeks of gestation. Eighty-nine fetuses of mothers with placenta previa and without pregnancy complications were recruited (placenta previa group) and matched with 89 fetuses of mothers with normal pregnancies (control group). Fetal cardiac function parameters and perinatal outcomes as well as the Mod-MPI were compared between the 2 groups. RESULTS The median Mod-MPI was significantly increased in fetuses of mothers with placenta previa compared with controls (0.47±0.05 vs. 0.45±0.05; P<0.01). Among fetuses of mothers with or without placenta previa, the Mod-MPI was significantly higher in the incomplete placenta previa group compared with the complete placenta previa group and control group (P<0.01). An increased Mod-MPI in placenta previa pregnancies was independently associated with fetal cord pH <7.2 (odds ratio, 4.8; 95% confidence interval, 0.98-23.54; P=0.003). CONCLUSIONS There is impairment of fetal cardiac function in pregnancies with placenta previa. An increased MPI was independently associated with adverse perinatal outcomes to some extent in the placenta previa pregnancies.

Assessment of Fetal Myocardial Performance Index in Women with Placenta Previa

PubMed Central

Zhang, Na; Sun, Lijuan; Zhang, Lina; Li, Zhen; Han, Jijing; Wu, Qingqing

2017-01-01

Background This study investigated whether fetuses of placenta previa pregnancies have cardiac dysfunction by use of a modified myocardial performance index (Mod-MPI). Material/Methods A prospective cross-sectional study was conducted including 178 fetuses at 28–40 weeks of gestation. Eighty-nine fetuses of mothers with placenta previa and without pregnancy complications were recruited (placenta previa group) and matched with 89 fetuses of mothers with normal pregnancies (control group). Fetal cardiac function parameters and perinatal outcomes as well as the Mod-MPI were compared between the 2 groups. Results The median Mod-MPI was significantly increased in fetuses of mothers with placenta previa compared with controls (0.47±0.05 vs. 0.45±0.05; P<0.01). Among fetuses of mothers with or without placenta previa, the Mod-MPI was significantly higher in the incomplete placenta previa group compared with the complete placenta previa group and control group (P<0.01). An increased Mod-MPI in placenta previa pregnancies was independently associated with fetal cord pH <7.2 (odds ratio, 4.8; 95% confidence interval, 0.98–23.54; P=0.003). Conclusions There is impairment of fetal cardiac function in pregnancies with placenta previa. An increased MPI was independently associated with adverse perinatal outcomes to some extent in the placenta previa pregnancies. PMID:29242496

vasa and piwi are required for mitotic integrity in early embryogenesis in the spider Parasteatoda tepidariorum.

PubMed

Schwager, Evelyn E; Meng, Yue; Extavour, Cassandra G

2015-06-15

Studies in vertebrate and invertebrate model organisms on the molecular basis of primordial germ cell (PGC) specification have revealed that metazoans can specify their germ line either early in development by maternally transmitted cytoplasmic factors (inheritance), or later in development by signaling factors from neighboring tissues (induction). Regardless of the mode of PGC specification, once animal germ cells are specified, they invariably express a number of highly conserved genes. These include vasa and piwi, which can play essential roles in any or all of PGC specification, development, or gametogenesis. Although the arthropods are the most speciose animal phylum, to date there have been no functional studies of conserved germ line genes in species of the most basally branching arthropod clade, the chelicerates (which includes spiders, scorpions, and horseshoe crabs). Here we present the first such study by using molecular and functional tools to examine germ line development and the roles of vasa and piwi orthologues in the common house spider Parasteatoda (formerly Achaearanea) tepidariorum. We use transcript and protein expression patterns of Pt-vasa and Pt-piwi to show that primordial germ cells (PGCs) in the spider arise during late embryogenesis. Neither Pt-vasa nor Pt-piwi gene products are localized asymmetrically to any embryonic region before PGCs emerge as paired segmental clusters in opisthosomal segments 2-6 at late germ band stages. RNA interference studies reveal that both genes are required maternally for egg laying, mitotic progression in early embryos, and embryonic survival. Our results add to the growing body of evidence that vasa and piwi can play important roles in somatic development, and provide evidence for a previously hypothesized conserved role for vasa in cell cycle progression. Copyright © 2014 Elsevier Inc. All rights reserved.

Placenta previa: an outcome-based cohort study in a contemporary obstetric population.

PubMed

Lal, Ann K; Hibbard, Judith U

2015-08-01

The objective of the study is to characterize the maternal and neonatal morbidities of women with placenta previa. This retrospective group study used the Consortium on Safe Labor electronic database, including 12 clinical centers, and 19 hospitals. Patients with placenta previa noted at the time of delivery were included. Maternal and neonatal variables were compared to a control group of women undergoing cesarean delivery with no previa. Logistic regression and general linear regression were used for the analysis, with p < 0.05 significance. There were 19,069 patients in the study: 452 in the placenta previa group and 18,617 in the control group. Neonates born to mothers with placenta previa had lower gestational ages and birth weights. In univariate analysis only, these neonates were at increased risk of lower 5 min Apgar scores, neonatal intensive care unit admission, anemia, respiratory distress syndrome, mechanical ventilation, and intraventricular hemorrhage. There was no association of placenta previa with small for gestational age infants, congenital anomalies or death. As previously shown, women with placenta previa have significantly more maternal morbidities. Increased maternal morbidity was noted; however, only those neonatal morbidities associated with preterm delivery occurred in the placenta previa group.

Placenta previa and maternal hemorrhagic morbidity.

PubMed

Gibbins, Karen J; Einerson, Brett D; Varner, Michael W; Silver, Robert M

2018-02-01

Placenta previa is associated with maternal hemorrhage, but most literature focuses on morbidity in the setting of placenta accreta. We aim to characterize maternal morbidity associated with previa and to define risk factors for hemorrhage. This is a secondary cohort analysis of the NICHD Maternal-Fetal Medicine Units Network Cesarean Section Registry. This analysis included all women undergoing primary Cesarean delivery without placenta accreta. About 496 women with previa were compared with 24,201 women without previa. Primary outcome was composite maternal hemorrhagic morbidity. Non-hemorrhagic morbidities and risk factors for hemorrhage were also evaluated. Maternal hemorrhagic morbidity was more common in women with previa (19 versus 7%, aRR 2.6, 95% CI 1.9-3.5). Atony requiring uterotonics (aRR 3.1, 95% CI 2.0-4.9), red blood cell transfusion (aRR 3.8, 95% CI 2.5-5.7), and hysterectomy (aRR 5.1, 95% CI 1.5-17.3) were also more common with previa. For women with previa, factors associated with maternal hemorrhage were pre-delivery anemia, thrombocytopenia, diabetes, magnesium use, and general anesthesia. Placenta previa is an independent risk factor for maternal hemorrhagic morbidity. Some risk factors are modifiable, but many are intrinsic to the clinical scenario.

Changes in first trimester screening test parameters in pregnancies complicated by placenta previa and association with hyperemesis gravidarum

PubMed Central

Tülek, Fırat; Kahraman, Alper; Taşkın, Salih; Özkavukçu, Esra; Söylemez, Feride

2014-01-01

Objective To assess the possible changes in first trimester screening test parameters in pregnancies complicated with placenta previa and to determine whether there is an association between hyperemesis gravidarum and placenta previa. Material and Methods A total of 131 singleton spontaneously conceived pregnancies that were complicated by placenta previa and delivered between May 2006 and May 2013 were evaluated from birth charts. Ninety patients without placenta previa were selected amongst patients who delivered within the same period of time as the control group. Cases of low lying placenta (n=52) within the study group were assessed as a separate group. The rest of the cases was considered to be in a different group. Results Beta human chorionic gonadotropin (BhCG) multiples of medians (MoMs) and nuchal translucency (NT) MoMs were significantly higher in the placenta previa group in comparison with the low lying placenta and control groups. Apgar scores at both the 1st and 5th minutes were significantly lower in the placenta previa group. Hyperemesis gravidarum was found to be significantly more frequent in the placenta previa group. Conclusion The prevalence of hyperemesis gravidarum in the first trimester is higher in pregnancies complicated by placenta previa. Paying more attention to the development of placenta previa in the routine pregnancy follow-up of patients with hyperemesis gravidarum could be considered. PMID:25584028

Changes in first trimester screening test parameters in pregnancies complicated by placenta previa and association with hyperemesis gravidarum.

PubMed

Tülek, Fırat; Kahraman, Alper; Taşkın, Salih; Özkavukçu, Esra; Söylemez, Feride

2014-01-01

To assess the possible changes in first trimester screening test parameters in pregnancies complicated with placenta previa and to determine whether there is an association between hyperemesis gravidarum and placenta previa. A total of 131 singleton spontaneously conceived pregnancies that were complicated by placenta previa and delivered between May 2006 and May 2013 were evaluated from birth charts. Ninety patients without placenta previa were selected amongst patients who delivered within the same period of time as the control group. Cases of low lying placenta (n=52) within the study group were assessed as a separate group. The rest of the cases was considered to be in a different group. Beta human chorionic gonadotropin (BhCG) multiples of medians (MoMs) and nuchal translucency (NT) MoMs were significantly higher in the placenta previa group in comparison with the low lying placenta and control groups. Apgar scores at both the 1st and 5th minutes were significantly lower in the placenta previa group. Hyperemesis gravidarum was found to be significantly more frequent in the placenta previa group. The prevalence of hyperemesis gravidarum in the first trimester is higher in pregnancies complicated by placenta previa. Paying more attention to the development of placenta previa in the routine pregnancy follow-up of patients with hyperemesis gravidarum could be considered.

[A retrospective analysis on the pernicious placenta previa from 2008 to 2014].

PubMed

Yu, L; Hu, K J; Yang, H X

2016-03-01

To investigate the incidence changes, clinical characteristics and pregnant outcomes of pernicious placenta previa. A retrospective cohort analysis on 316 cases with placenta previa in the Peking University First Hospital from January 2008 to December 2014. The research group were 60 cases with the patients of placenta previa with the history of cesarean section, and the control group were placenta previa without the history of cesarean section. Compared with the incidence, intraoperative blood loss, the pregnancy outcomes and so on. (1) The average incidence rate of placenta previa during the past 7 years was 10.96 ‰ (316/28 837). And the cases of pernicious placenta previa was 60 (2.08‰, 60/28 837), the incidence of pernicious placenta previa was rising from 2008 to 2014 (0.91‰-3.08‰). (2) There were 145 cases of placenta privia had been translation from other hospitals in the past 7 years. The referral rate of pregnant women with placenta previa was 45.9% (145/316), and the referral rate of pernicious placenta previa (63.3%, 38/60) was significantly higher than that of non-pernicious placenta previa group (41.8%, 107/256; χ(2)=9.080, P=0.003). Referral the outcomes of these patients were good, and no maternal death occurred. (3) The placenta in the research group were mainly adhered in the front wall of the uterine, and the incidence was 38.5% (15/39), higher than that in the group of non-pernicious placenta previa (12.1%, 21/174; χ(2)=57.636, P<0.01). The incidence rate of complicated placenta increased in research group was 53.3% (32/60), higher than that in the group of non-pernicious placenta previa, compared with the control group, there was significant difference (15.6%, 40/256; χ(2)= 39.041, P<0.01). (4) The incidence of blood loss was more than 1 000 ml, blood transfusion rate, the rate of hysterectomy and the rate of asphyxia of newborn in the research group were respectively 41.7% (25/60), 38.3% (23/60), 8.3% (5/60), 15.0% (9/60), and the incidence of the group of non-pernicious placenta previa were respectively 4.7% (12/256), 12.9% (33/256), 1.2% (3/256), 8.6% (22/256), compared those in other two groups, there were not significant difference (P<0.05). The incidence rate of placenta previa increased year by year, patients with placenta previa has a history of cesarean section often combined with placenta in anterior wall of the uterus, and often with poor pregnancy outcomes. Hierarchical referral system is an effective means to reduce the mortality of the pernicious placenta previa.

Placenta previa and the risk of delivering a small-for-gestational-age newborn.

PubMed

Räisänen, Sari; Kancherla, Vijaya; Kramer, Michael R; Gissler, Mika; Heinonen, Seppo

2014-08-01

To evaluate whether there is an association between placenta previa and delivery of a small-for-gestational-age (SGA) newborn and to quantify the contribution of individual risk factors for SGA that are associated with placenta previa stratified by maternal parity. A cross-sectional study using the Finnish Medical Birth Register during 2000-2010. All singleton births (N=596,562) were included; major congenital anomalies were excluded. An association between SGA (less than 2 standard deviations below the mean) and placenta previa was modeled by parity-specific unadjusted and adjusted statistical models. Placenta previa complicated 625 of 249,476 singleton births among nulliparous women (2.50/1,000) and 915 of 347,086 singleton births among multiparous women (2.64/1,000). Among nulliparous women, the most common risk factor for placenta previa was in vitro fertilization; placenta previa was not associated with an increased prevalence of SGA controlling for maternal age, smoking, in vitro fertilization, socioeconomic status, and preeclampsia (adjusted odds ratio [OR] 0.81, 95% confidence interval [CI] 0.57-1.17). Among multiparous women, placenta previa was associated with a twofold increased risk of SGA controlling for maternal age, parity, prior preterm birth, prior caesarean delivery, prior SGA newborn, prior preeclampsia, smoking, in vitro fertilization, socioeconomic status, and preeclampsia (adjusted OR 2.08, 95% CI 1.50-2.89). Furthermore, only one-fourth of the association between SGA and placenta previa could be explained by controlling for risk factors clustering with placenta previa among multiparous women. Placenta previa is associated with impaired fetal growth in multiparous but not nulliparous women. II.

Placenta Previa and the Risk of Delivering a Small-for-Gestational-Age Newborn

PubMed Central

Kancherla, Vijaya; Kramer, Michael R.; Gissler, Mika; Heinonen, Seppo

2014-01-01

Objective To evaluate whether there is an association between placenta previa and delivery of a small-for-gestational-age (SGA) newborn and to quantify the contribution of individual risk factors for SGA that are associated with placenta previa, stratified by maternal parity. Methods A cross sectional study utilizing the Finnish Medical Birth Register during 2000–2010. All singleton births (N=596,562) were included; major congenital anomalies were excluded. An association between SGA (< 2 standard deviations below the mean) and placenta previa was modeled by parity-specific unadjusted and adjusted statistical models. Results Placenta previa complicated 625 of 249,476 singleton births among nulliparous women (2.50/1,000) and (915 of 347,086 singleton births among multiparous women (2.64/1,000). Among nulliparous women, the most common risk factor for placenta previa was in vitro fertilization (IVF); placenta previa was not associated with an increased prevalence of SGA, controlling for maternal age, smoking, IVF, socioeconomic status, and preeclampsia (aOR=0.81; 95% CI=0.57–1.17). Among multiparous women, placenta previa was associated with a two-fold increased risk of SGA, controlling for maternal age, parity, prior preterm birth, prior caesarean delivery, prior SGA newborn, prior preeclampsia, smoking, IVF, socioeconomic status, and preeclampsia (aOR=2.08; 95% CI=1.50–2.89). Further, only one fourth of the association between SGA and placenta previa could be explained by controlling for risk factors clustering with placenta previa among multiparous women. Conclusions Placenta previa is associated with impaired fetal growth in multiparous but not nulliparous women. PMID:25004348

Prevalence of placenta previa among deliveries in Mainland China: A PRISMA-compliant systematic review and meta-analysis.

PubMed

Fan, Dazhi; Wu, Song; Wang, Wen; Xin, Lihong; Tian, Guo; Liu, Li; Feng, Jinping; Guo, Xiaoling; Liu, Zhengping

2016-10-01

Placenta previa is characterized by the abnormal placenta overlying the endocervical os, and it is known as one of the most feared adverse maternal and fetal-neonatal complications in obstetrics. We aimed to obtain overall and regional estimates of placenta previa prevalence among deliveries in Mainland China. The research was performed a systematic review, following the Meta-analysis of observational studies in epidemiology (MOOSE) guidelines for systematic reviews of observational studies, and the preferred reporting items for systematic reviews and meta-analysis (PRISMA) statement for reporting systematic reviews and meta-analysis. Electronic databases were searched and included hospital-based studies that reported placenta previa prevalence in Mainland China. Random-effects meta-analyses were used to pool prevalence estimates of placenta previa. Meta-regression analyses were performed to explore sources of heterogeneity across the included studies. For exploring the geographical distributions of placenta previa, the ArcGIS software (Esri) was used to construct the map of prevalence. A total of 80 articles and 86 datasets (including 1,298,548 subjects and 14,199 placenta previa cases) from 1965 through 2015 were included. The pooled overall prevalence of placenta previa among deliveries was 1.24% (95% confidence interval [CI], 1.12-1.36) in Mainland China during 1965 to 2015. And, the trend in the prevalence of placenta previa was steady. The occurrence rate of placenta previa in the region groups Northeast, North, Northwest, Central China, East, South, and Southwest was 1.20%, 1.01%, 1.10%, 1.15%, 0.93%, 1.42%, and 2.01%, respectively. The prevalence map based on a geographic information system showed an unequal geographic distribution. The results showed that placenta previa is currently a high-burden disease in Mainland China. This review would be useful for the design of placenta previa planning and implementation adequate health care systems and treatment programs in Mainland China.

Increased Levels of Cell-Free miR-517a and Decreased Levels of Cell-Free miR-518b in Maternal Plasma Samples From Placenta Previa Pregnancies at 32 Weeks of Gestation.

PubMed

Hasegawa, Yuri; Miura, Kiyonori; Higashijima, Ai; Abe, Shuhei; Miura, Shoko; Yoshiura, Koh-ichiro; Masuzaki, Hideaki

2015-12-01

The aim of this study was to clarify the association between placenta previa and circulating levels of cell-free pregnancy-associated placenta-specific microRNAs (miRNAs) in maternal plasma. Twenty singleton pregnancies with placenta previa (placenta previa group) and 26 uncomplicated pregnancies (control group) were recruited. Blood sampling was performed at 32 weeks of gestation, and cesarean delivery in all cases of placenta previa was performed at a mean gestational age of 37 weeks. The maternal plasma concentrations of cell-free pregnancy-associated placenta-specific miRNAs (miR-517a and miR-518b) were measured by absolute quantitative real-time reverse transcription-polymerase chain reaction. Plasma concentrations of cell-free miR-517a were significantly higher in the placenta previa group than that in the control group (P = .011), while the plasma concentration of cell-free miR-518b was significantly lower in the placenta previa group than that in the control group (P = .004). Plasma concentrations of cell-free miR-517a in placenta previa were significantly higher in placenta previa with alert bleeding later group than those in placenta previa without alert bleeding group or control group (P = .030 or .047, respectively) and correlated with the volume of hemorrhage at delivery (R and P value: .512 and .025). Plasma concentrations of cell-free miR-517a and miR-518b at 32 weeks of gestation were altered in pregnant women with placenta previa, and the circulating level of cell-free miR-517a in placenta previa may be a predictive marker for the risks of alert bleeding later and massive hemorrhage at delivery. © The Author(s) 2015.

Prevalence of placenta previa among deliveries in Mainland China

PubMed Central

Fan, Dazhi; Wu, Song; Wang, Wen; Xin, Lihong; Tian, Guo; Liu, Li; Feng, Jinping; Guo, Xiaoling; Liu, Zhengping

2016-01-01

Abstract Background: Placenta previa is characterized by the abnormal placenta overlying the endocervical os, and it is known as one of the most feared adverse maternal and fetal-neonatal complications in obstetrics. Objectives: We aimed to obtain overall and regional estimates of placenta previa prevalence among deliveries in Mainland China. Methods: The research was performed a systematic review, following the Meta-analysis of observational studies in epidemiology (MOOSE) guidelines for systematic reviews of observational studies, and the preferred reporting items for systematic reviews and meta-analysis (PRISMA) statement for reporting systematic reviews and meta-analysis. Electronic databases were searched and included hospital-based studies that reported placenta previa prevalence in Mainland China. Random-effects meta-analyses were used to pool prevalence estimates of placenta previa. Meta-regression analyses were performed to explore sources of heterogeneity across the included studies. For exploring the geographical distributions of placenta previa, the ArcGIS software (Esri) was used to construct the map of prevalence. Results: A total of 80 articles and 86 datasets (including 1,298,548 subjects and 14,199 placenta previa cases) from 1965 through 2015 were included. The pooled overall prevalence of placenta previa among deliveries was 1.24% (95% confidence interval [CI], 1.12–1.36) in Mainland China during 1965 to 2015. And, the trend in the prevalence of placenta previa was steady. The occurrence rate of placenta previa in the region groups Northeast, North, Northwest, Central China, East, South, and Southwest was 1.20%, 1.01%, 1.10%, 1.15%, 0.93%, 1.42%, and 2.01%, respectively. The prevalence map based on a geographic information system showed an unequal geographic distribution. Conclusions: The results showed that placenta previa is currently a high-burden disease in Mainland China. This review would be useful for the design of placenta previa planning and implementation adequate health care systems and treatment programs in Mainland China. PMID:27749592

Interbirth Interval and Pregnancy Complications and Outcomes: Findings from the Pregnancy Risk Assessment Monitoring System.

PubMed

Brunner Huber, Larissa R; Smith, Kenesha; Sha, Wei; Vick, Tara

2018-05-25

Although the definition of a short interbirth interval has been inconsistent in the literature, Healthy People 2020 recommends that women wait at least 18 months after a live birth before attempting their next pregnancy. In the United States, approximately 33% of pregnancies are conceived within 18 months of a previous birth. Pregnancies that result from short interbirth intervals can pose serious risks. The objective of this study was to determine the association between interbirth interval and understudied pregnancy complications and outcomes, including small for gestational age (SGA) infants, premature rupture of membranes (PROM), preterm PROM (PPROM), placenta previa, and gestational diabetes, using Pregnancy Risk Assessment and Monitoring System data from Mississippi and Tennessee. This study collected self-reported information from 2212 women on interbirth interval (≤18 months, ie, short; 19-35 months, ie, intermediate; and ≥36 months, ie, long; referent), PPROM, placenta previa, and gestational diabetes. SGA and PROM data were obtained from birth certificates. Logistic regression was used to calculate odds ratios (ORs) and 95% CIs. After adjustment, there were no strong associations between interbirth interval and PPROM, gestational diabetes, or SGA infants. However, women with shorter intervals had increased odds of PROM (short: OR, 3.54; 95% CI, 1.22-10.23 and intermediate: OR, 4.09; 95% CI, 1.28-13.03) and placenta previa (short: OR, 2.58; 95% CI, 1.10-6.05 and intermediate: OR, 1.69; 95% CI, 0.94-3.05). The study's findings provide further support for encouraging women to space their pregnancies appropriately. Moreover, findings underscore the need to provide women with family planning services so that closely spaced pregnancies and unintended pregnancies can be avoided. Additional studies of the role of interbirth interval on these understudied pregnancy complications and outcomes are warranted. © 2018 by the American College of Nurse-Midwives.

Effect of placenta previa on neonatal respiratory disorders and amniotic lamellar body counts at 36-38weeks of gestation.

PubMed

Tsuda, Hiroyuki; Kotani, Tomomi; Sumigama, Seiji; Mano, Yukio; Hua, Li; Hayakawa, Hiromi; Hayakawa, Masahiro; Sato, Yoshiaki; Kikkawa, Fumitaka

2014-01-01

Pregnancies with placenta previa are significantly associated with preterm delivery and cesarean section. Therefore particular attention should be paid to the incidence of neonatal respiratory disorders in pregnancies with placenta previa. The purpose of this study is to examine the relationship between placenta previa and neonatal respiratory disorders, including respiratory distress syndrome (RDS) and transient tachypnea of the newborn (TTN), and to evaluate the impact of placenta previa on the amniotic lamellar body count (LBC) values. We analyzed the data from 186 registered elective cesarean cases without fetal or maternal complications at 36-38weeks of gestation. Amniotic fluid samples were analyzed immediately without centrifugation, and the LBC was measured using a platelet channel on the Sysmex XE-2100. RDS was present in four neonates (2.2%) and TTN in 12 neonates (6.5%). The rate of TTN was significantly higher and the LBC values were significantly lower in the placenta previa group than in the control group (P=0.002 and P=0.024). The adjusted odds ratio for neonatal TTN was 7.20 (95% confidence interval: 6.58-7.88) among females with placenta previa. In placenta previa, warning bleeding was a significant factor protecting against neonatal respiratory disorders (P=0.046). Placenta previa in itself is a risk factor for neonatal TTN. When an elective cesarean section is performed in cases with uncomplicated placenta previa, special care should be taken to monitor for neonatal TTN even at 36-38weeks of gestation. © 2013.

Arterial wall perfusion measured with photon counting spectral x-ray CT

NASA Astrophysics Data System (ADS)

Jorgensen, Steven M.; Korinek, Mark J.; Vercnocke, Andrew J.; Anderson, Jill L.; Halaweish, Ahmed; Leng, Shuai; McCollough, Cynthia H.; Ritman, Erik L.

2016-10-01

Early atherosclerosis changes perfusion of the arterial wall due to localized proliferation of the vasa vasorum. When contrast agent passes through the artery, some enters the vasa vasorum and increases radiopacity of the arterial wall. Technical challenges to detecting changes in vasa vasorum density include the thin arterial wall, partial volume averaging at the arterial lumen/wall interface and calcification within the wall. We used a photon-counting spectral CT scanner to study carotid arteries of anesthetized pigs and micro-CT of these arteries to quantify vasa vasorum density. The left carotid artery wall was injected with autologous blood to stimulate vasa vasorum angiogenesis. The scans were performed at 25-120 keV; the tube-current-time product was 550 mAs. A 60 mL bolus of iodine contrast agent was injected into the femoral vein at 5mL/s. Two seconds post injection, an axial scan was acquired at every 3 s over 60 s (i.e., 20 time points). Each time point acquired 28 contiguous transaxial slices with reconstructed voxels 0.16 x 0.16 x 1 mm3. Regions-of-interest in the outer 2/3 of the arterial wall and in the middle 2/3 of the lumen were drawn and their enhancements plotted versus time. Lumenal CT values peaked several seconds after injection and then returned towards baseline. Arterial wall CT values peaked concurrent to the lumen. The peak arterial wall enhancement in the left carotid arterial wall correlated with increased vasa vasorum density observed in micro-CT images of the isolated arteries.

Arterial Wall Perfusion Measured with Photon Counting Spectral X-ray CT.

PubMed

Jorgensen, Steven M; Korinek, Mark J; Vercnocke, Andrew J; Anderson, Jill L; Halaweish, Ahmed; Leng, Shuai; McCollough, Cynthia H; Ritman, Erik L

2016-08-28

Early atherosclerosis changes perfusion of the arterial wall due to localized proliferation of the vasa vasorum. When contrast agent passes through the artery, some enters the vasa vasorum and increases radiopacity of the arterial wall. Technical challenges to detecting changes in vasa vasorum density include the thin arterial wall, partial volume averaging at the arterial lumen/wall interface and calcification within the wall. We used a photon-counting spectral CT scanner to study carotid arteries of anesthetized pigs and micro-CT of these arteries to quantify vasa vasorum density. The left carotid artery wall was injected with autologous blood to stimulate vasa vasorum angiogenesis. The scans were performed at 25-120 keV; the tube-current-time product was 550 mAs. A 60 mL bolus of iodine contrast agent was injected into the femoral vein at 5mL/s. Two seconds post injection, an axial scan was acquired at every 3 s over 60 s (i.e., 20 time points). Each time point acquired 28 contiguous transaxial slices with reconstructed voxels 0.16 × 0.16 × 1 mm 3 . Regions-of-interest in the outer 2/3 of the arterial wall and in the middle 2/3 of the lumen were drawn and their enhancements plotted versus time. Lumenal CT values peaked several seconds after injection and then returned towards baseline. Arterial wall CT values peaked concurrent to the lumen. The peak arterial wall enhancement in the left carotid arterial wall correlated with increased vasa vasorum density observed in micro-CT images of the isolated arteries.

Effect of Placenta Previa on Fetal Growth

PubMed Central

HARPER, Lorie M.; ODIBO, Anthony O.; MACONES, George A.; CRANE, James P.; CAHILL, Alison G.

2011-01-01

Objective To estimate the association between placenta previa and abnormal fetal growth. Study Design Retrospective cohort study of consecutive women undergoing ultrasound between 15–22 weeks. Groups were defined by the presence or absence of complete or partial placenta previa. The primary outcome was intrauterine growth restriction (IUGR), defined as a birth weight <10th percentile by the Alexander growth standard. Univariable, stratified and multivariable analyses were used to estimate the effect of placenta previa on fetal growth restriction. Results Of 59,149 women, 724 (1.2%) were diagnosed with a complete or partial previa. After adjusting for significant confounding factors (black race, gestational diabetes, preeclampsia, and single umbilical artery,), the risk of IUGR remained similar (adjusted odds ratio 1.1, 95% CI 0.9–1.5). The presence of bleeding did not impact the risk of growth restriction. Conclusion Placenta previa is not associated with fetal growth restriction. Serial growth ultrasounds are not indicated in patients with placenta previa. PMID:20599185

Uterine artery embolization, not cesarean section, as an option for termination of pregnancy in placenta previa.

PubMed

Huang, Lingling; Awale, Reenu; Tang, Hui; Zeng, ZhiShan; Li, FuRong; Chen, Yue

2015-04-01

To summarize our experiences in the treatment of labor induction in placenta previa using uterine artery embolization. We retrospectively analyzed the clinical data of seven patients with placenta previa who underwent antepartum uterine artery embolization before vaginal delivery. After antepartum embolization, five patients with placenta previa had successful vaginal deliveries and two cases of placenta previa with accreta underwent emergency hysterectomy. Some complications were reported in this experience. The follow-up study showed that most patients resumed their normal menstruation and some of them were able to conceive. For the management of placenta previa, uterine artery embolization is a minimally invasive technique that helps to avoid cesarean section. The impact on menstruation and fertility is yet to be seen. Copyright © 2015. Published by Elsevier B.V.

The role of shear wave elastography in the assessment of placenta previa-accreta.

PubMed

Alıcı Davutoglu, Ebru; Ariöz Habibi, Hatice; Ozel, Ayşegül; Yuksel, Mehmet Aytac; Adaletli, Ibrahim; Madazlı, Riza

2018-06-01

To evaluate the value of shear wave elastography (SWE) in the prediction of morbidly adherent placenta. Forty-three women with normal placental location and 26 women with anteriorly localized placenta previa were recruited for this case-control study. Placental elasticity values in both the groups were determined by SWE imaging. SWE values were higher in the placenta previa group in all regions than in normal localized placentas (p < .01). However, there was no statistically significant difference between SWE values of placenta previa with and without morbidly adherent placenta (p > .05). Placental stiffness is significantly higher in placenta previa than normal localized placentas. However, we could not demonstrate any statistically significant difference in the elasticity values between the placenta previa with and without accreta.

[Risk factors of peripartum hysterectomy in placenta previa: a retrospective study of 3 840 cases].

PubMed

Lyu, B; Chen, M; Liu, X X

2016-07-25

To investigate the risk factors of peripartum hysterectomy in placenta previa through retrospective study of 3 840 placenta previa cases. The clinical data of 3 840 patients with placenta previa who delivered in West China Second University Hospital between Jan 2005 and June 2014 were analyzed retrospectively. The relationship of certain factors and peripartum hysterectomy was analyzed, including maternal age, residence place, parity, prior curettage, prior cesarean section, twin or multiple pregnancy, antenatal vaginal bleeding, type of placenta previa, suspected placenta accreta, antenatal level of hemoglobin and gestational age at delivery. The prevalence of placenta previa was 4.84%(3 840/79 304)in West China Second University Hospital during the study period, and the incidence of preipartum hysterectomy in patients with placenta previa was 2.76%(106/3 840). One-factor analysis demonstrated that residence place, parity, times of prior curettage, prior cesarean section, prenatal vaginal bleeding, anterior placenta, type of placenta previa, placenta accreta, antenatal anemia and gestational age at delivery were potential risk factors for peripartum hysterectomy(P<0.01). Variables with P<0.1 in one-factor analysis were introduced to multi-factor logistic regression analysis, which suggested that one prior cesarean section(OR=12.9,95% CI:6.3-26.3), two or more prior cesarean sections(OR=14.4, 95%CI:3.9-53.2), anterior placenta(OR=4.8, 95%CI:2.1-10.7), complete placenta previa(OR=5.9, 95%CI: 1.8-42.5), placenta accreta(OR=11.2, 95%CI:6.8-18.6), antenatal hemoglobin<100 g/L(OR=1.7, 95%CI: 1.0-2.8)and delivery before 34 gestational weeks(OR=3.2, 95%CI: 1.6-6.3)were independent risk factors of peripartum hysterectomy in patients with placenta previa(P<0.05). Prior cesarean section, anterior placenta, complete placenta previa, placenta accreta, antenatal anemia and delivery before 34 gestational weeks are high risk factors of peripartum hysterectomy in placenta previa patients. Perinatal care and risk evaluation before cesarean section are important to improve perinatal outcomes and reduce peripartum hysterectomy.

Sequence and expression pattern of the germ line marker vasa in honey bees and stingless bees

PubMed Central

2009-01-01

Queens and workers of social insects differ in the rates of egg laying. Using genomic information we determined the sequence of vasa, a highly conserved gene specific to the germ line of metazoans, for the honey bee and four stingless bees. The vasa sequence of social bees differed from that of other insects in two motifs. By RT-PCR we confirmed the germ line specificity of Amvasa expression in honey bees. In situ hybridization on ovarioles showed that Amvasa is expressed throughout the germarium, except for the transition zone beneath the terminal filament. A diffuse vasa signal was also seen in terminal filaments suggesting the presence of germ line cells. Oocytes showed elevated levels of Amvasa transcripts in the lower germarium and after follicles became segregated. In previtellogenic follicles, Amvasa transcription was detected in the trophocytes, which appear to supply its mRNA to the growing oocyte. A similar picture was obtained for ovarioles of the stingless bee Melipona quadrifasciata, except that Amvasa expression was higher in the oocytes of previtellogenic follicles. The social bees differ in this respect from Drosophila, the model system for insect oogenesis, suggesting that changes in the sequence and expression pattern of vasa may have occurred during social evolution. PMID:21637523

Prior Prelabor or Intrapartum Cesarean Delivery and Risk of Placenta Previa

PubMed Central

Downes, Katheryne L.; Hinkle, Stefanie N.; Sjaarda, Lindsey A.; Albert, Paul S.; Grantz, Katherine L.

2015-01-01

Objective To examine the association between previous cesarean delivery and subsequent placenta previa while distinguishing cesarean delivery prior to onset of labor from intrapartum cesarean delivery. Study Design Retrospective cohort study of electronic medical records from 20 Utah hospitals (2002–2010) with restriction to the first two singleton deliveries of women nulliparous at study entry (n=26,987). First pregnancy delivery mode was classified as 1) vaginal (reference); 2) cesarean delivery prior to labor onset (prelabor); or 3) cesarean delivery after labor onset (intrapartum). Risk of second delivery previa was estimated by prior delivery mode using logistic regression and adjusted for maternal age, insurance, smoking, co-morbidities, prior pregnancy loss, and history of previa. Results The majority of first deliveries were vaginal (82%, n=22,142), followed by intrapartum cesarean delivery (14.6%, n=3,931), or prelabor cesarean delivery (3.4%, n=914). Incidence of second delivery previa was 0.29% (n=78) and differed by prior delivery mode: vaginal, 0.24%; prelabor cesarean delivery, 0.98%; intrapartum cesarean delivery, 0.38% (P<0.001). Relative to vaginal delivery, prior prelabor cesarean delivery was associated with an increased risk of second delivery previa (adjusted odds ratio, 2.62 [95% confidence interval, 1.24–5.56]). There was no significant association between prior intrapartum cesarean delivery and previa [adjusted odds ratio, 1.22 (95% confidence interval, 0.68–2.19)]. Conclusion Prior prelabor cesarean delivery was associated with a more than two-fold significantly increased risk of previa in the second delivery, while the approximately 20% increased risk of previa associated with prior intrapartum cesarean delivery was not significant. Although rare, the increased risk of placenta previa after prior prelabor cesarean delivery may be important when considering non-medically indicated prelabor cesarean delivery. PMID:25576818

Previous prelabor or intrapartum cesarean delivery and risk of placenta previa.

PubMed

Downes, Katheryne L; Hinkle, Stefanie N; Sjaarda, Lindsey A; Albert, Paul S; Grantz, Katherine L

2015-05-01

The purpose of this study was to examine the association between previous cesarean delivery and subsequent placenta previa while distinguishing cesarean delivery before the onset of labor from intrapartum cesarean delivery. We conducted a retrospective cohort study of electronic medical records from 20 Utah hospitals (2002-2010) with restriction to the first 2 singleton deliveries of nulliparous women at study entry (n=26,987). First pregnancy delivery mode was classified as (1) vaginal (reference), (2) cesarean delivery before labor onset (prelabor), or (3) cesarean delivery after labor onset (intrapartum). Risk of second delivery previa was estimated by previous delivery mode with the use of logistic regression and was adjusted for maternal age, insurance, smoking, comorbidities, previous pregnancy loss, and history of previa. Most first deliveries were vaginal (82%; n=22,142), followed by intrapartum cesarean delivery (14.6%; n=3931), or prelabor cesarean delivery (3.4%; n=914). Incidence of second delivery previa was 0.29% (n=78) and differed by previous delivery mode: vaginal, 0.24%; prelabor cesarean delivery, 0.98%; intrapartum cesarean delivery, 0.38% (P<.001). Relative to vaginal delivery, previous prelabor cesarean delivery was associated with an increased risk of second delivery previa (adjusted odds ratio, 2.62; 95% confidence interval, 1.24-5.56). There was no significant association between previous intrapartum cesarean delivery and previa (adjusted odds ratio, 1.22; 95% confidence interval, 0.68-2.19). Previous prelabor cesarean delivery was associated with a >2-fold significantly increased risk of previa in the second delivery, although the approximately 20% increased risk of previa that was associated with previous intrapartum cesarean delivery was not significant. Although rare, the increased risk of placenta previa after previous prelabor cesarean delivery may be important when considering nonmedically indicated prelabor cesarean delivery. Published by Elsevier Inc.

Ultrasonographic findings of placenta lacunae and a lack of a clear zone in cases with placenta previa and normal placenta.

PubMed

Hamada, Shoko; Hasegawa, Junichi; Nakamura, Masamitsu; Matsuoka, Ryu; Ichizuka, Kiyotake; Sekizawa, Akihiko; Okai, Takashi

2011-11-01

To evaluate whether the frequencies of placenta lacunae and lack of a clear zone are higher in cases of placenta previa compared with those without it. Ultrasonographic findings just before delivery, including placenta lacunae and lack of a clear zone were prospectively evaluated in consecutive subjects. After collection, a case-control study with 1:5 matched pairs was conducted. The frequencies of ultrasonographic findings were analyzed in cases with placenta previa and normal placenta. Seventy cases with placenta previa and 350 cases with normal placentas were observed. Five and zero cases with abnormal placental adherence were observed in cases with placenta previa and normal placenta, respectively. Lack of a clear zone was observed in 60 and 1.5% of cases with and without the placental adherence (p = 0.001). Placenta lacunae and lack of a clear zone were observed in 31.4 and 9.7% of cases with and without placenta previa [odds ratio (OR) 4.2]. Lack of a clear zone was observed in 5.7 and 0.9% of cases with and without placenta previa (OR 7.0). Placenta lacunae and lack of a clear zone are frequently observed in placenta previa even when there is no adherence of the placenta. Copyright © 2011 John Wiley & Sons, Ltd.

Placenta previa

PubMed Central

Abduljabbar, Hassan S.; Bahkali, Nedaa M.; Al-Basri, Samera F.; Hachim, Estabrq Al; Shoudary, Ibrahim H.; Dause, Wesam R.; Mira, Mohammed Y.; Khojah, Mohammed

2016-01-01

Objectives: To review cases of placenta previa in the last 13 years in a tertiary teaching hospital to identify risk factors for maternal morbidity. Methods: A retrospective analysis of all cases of placenta previa managed at King Abdulaziz University Hospital (KAUH), Jeddah, Kingdom of Saudi Arabia from January 2001 to December 2013. Results: The total number of deliveries was 55,862 deliveries, and 11,412 (20.3%) delivered by cesarean section (C/S). The charts of 230 cases diagnosed with placenta previa was reviewed, and different variables were collected and analyzed. Diagnoses were achieved in 94% of them using ultrasound. The prevalence rate of placenta previa was 4.1 per 1000 births. Cesarean section was carried out as an emergency procedure in 130 (56.5%) women and as elective in 100 (43.5%) women. Of them, 26 patients were admitted to the intensive care unit (ICU) (11.3%), all of which received blood transfusion >6 units and 22 patients had a hysterectomy for uncontrollable bleeding. Conclusion: Placenta previa is one of the leading causes of maternal morbidity and mortality. Every hospital must have a protocol, or algorithm for the management of placenta previa. Risk factors for maternal morbidity included complete previa, history of previous C/S, emergency C/S at a gestational age of <36 weeks, and estimated blood loss >2000 ml. PMID:27381536

Cloning, characterization, and expression analysis of the DEAD-box family genes, Fc-vasa and Fc-PL10a, in Chinese shrimp ( Fenneropenaeus chinensis)

NASA Astrophysics Data System (ADS)

Zhou, Qianru; Shao, Mingyu; Qin, Zhenkui; Kyoung, Ho Kang; Zhang, Zhifeng

2010-01-01

RNA helicases of the DEAD-box and related families are involved in various cellular processes including DNA replication, DNA repair, and RNA processing. However, the function of DEAD-box proteins in aquaculture species is poorly understood at molecular level. We obtained the full-length cDNA sequences of two genes encoding helicase-related proteins, Fc-vasa and Fc-PL10a, from the testes of Chinese shrimp, Fenneropenaeus chinensis. The two predicted amino acid sequences contain all the conserved motifs characterized by the DEAD-box family and several RGG repeats in the N-terminal regions. Homology and phylogenetic analyses indicate that they belong to the vasa and PL10 subfamilies. The three-dimensional structures of the two proteins were predicted with a homology modeling approach. Both core proteins consist of two tandem RecA-like domains similar to those of the DEAD-box RNA helicase. Using reverse transcription-polymerase chain reaction (RT-PCR) and real-time PCR we found that Fc-vasa was expressed specifically in the adult gonads. Transcription decreased in the ovary but increased in the testis during gonadal development. Fc-PL10a expression was widely distributed in the tissues we examined. Using in situ hybridization, we demonstrated that the Fc-vasa transcript is localized to the cytoplasm of the spermatogonia and oocytes. Thus, our results suggest that Fc-vasa plays an important role in germ-line development, and has utility as a germ cell lineage marker which will help to generate new insight into the origin and differentiation of germ cells as well as the regulation of reproduction in F. chinensis.

Ischemic Effects of Transcatheter Arterial Embolization with N-Butyl Cyanoacrylate-Lipiodol on the Colon in a Swine Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ikoma, Akira; Kawai, Nobuyuki; Sato, Morio, E-mail: morisato@wakayama-med.ac.jp

2010-10-15

This study was designed to assess the safety of transcatheter arterial embolization (TAE) with n-butyl cyanoacrylate-lipiodol (NBCA-Lp) for the large bowel and to investigate the vital response to NBCA-Lp in a swine model. In nine swine, nine arteries nourishing the colon were embolized with NBCA-Lp (1 ml of NBCA mixed with 4 ml of lipiodol): sigmoid-rectal branch artery in six swine, right colic branch artery in two, and middle colic branch artery in one. The amount of NBCA-Lp was 0.1-0.4 ml. Sacrifice was conducted 3 days after TAE to identify histological infarction. Classification was conducted retrospectively: group A, vasa rectamore » without NBCA-Lp embolization despite TAE; group B, three or fewer vasa recta with NBCA-Lp embolization; and group C, five or more vasa recta with NBCA-Lp embolization. In one swine in group A, no necrotic focus was observed. In group B, three of four swine experienced no ischemic damage. The remaining one swine experienced necrosis of mucosal and submucosal layers in one-fourth of the circumference. In group C, all four swine with marginal artery and five vasa recta or more embolized experienced total necrosis of mucosa, submucosa, and smooth muscle layers of the whole colonic circumference. Significant difference on the extent of ischemic damage was observed between groups B and C (P < 0.05). Microscopically, NBCA-Lp induced acute vasculitis. Embolization of three or fewer vasa recta with NBCA-Lp induced no ischemic damage or limited necrosis, whereas embolization of five or more vasa recta with NBCA-Lp induced extensive necrosis.« less

Effects of transgenic sterilization constructs and their repressor compounds on hatch, developmental rate and early survival of electroporated channel catfish embryos and fry.

PubMed

Su, Baofeng; Shang, Mei; Li, Chao; Perera, Dayan A; Pinkert, Carl A; Irwin, Michael H; Peatman, Eric; Grewe, Peter; Patil, Jawahar G; Dunham, Rex A

2015-04-01

Channel catfish (Ictalurus punctatus) embryos were electroporated with sterilization constructs targeting primordial germ cell proteins or with buffer. Some embryos then were treated with repressor compounds, cadmium chloride, copper sulfate, sodium chloride or doxycycline, to prevent expression of the transgene constructs. Promoters included channel catfish nanos and vasa, salmon transferrin (TF), modified yeast Saccharomyces cerevisiae copper transport protein (MCTR) and zebrafish racemase (RM). Knock-down systems were the Tet-off (nanos and vasa constructs), MCTR, RM and TF systems. Knock-down genes included shRNAi targeting 5' nanos (N1), 3' nanos (N2) or dead end (DND), or double-stranded nanos RNA (dsRNA) for overexpression of nanos mRNA. These constructs previously were demonstrated to knock down nanos, vasa and dead end, with the repressors having variable success. Exogenous DNA affected percentage hatch (% hatch), as all 14 constructs, except for the TF dsRNA, TF N1 (T), RM DND (C), vasa DND (C), vasa N1 (C) and vasa N2 (C), had lower % hatch than the control electroporated with buffer. The MCTR and RM DND (T) constructs resulted in delayed hatch, and the vasa and nanos constructs had minimal effects on time of hatch (P < 0.05). Cadmium chloride appeared to counteract the slow development caused by the TF constructs in two TF treatments (P < 0.05). The 4 ppt sodium chloride treatment for the RM system decreased % hatch (P < 0.05) and slowed development. In the case of nanos constructs, doxycycline greatly delayed hatch (P < 0.05). Adverse effects of the transgenes and repressors continued for several treatments for the first 6 days after hatch, but only in a few treatments during the next 10 days. Repressors and gene expression impacted the yield of putative transgenic channel catfish fry, and need to be considered and accounted for in the hatchery phase of producing transgenically sterilized catfish fry and their fertile counterparts. This fry output should be considered to ensure that sufficient numbers of transgenic fish are produced for future applications and for defining repressor systems that are the most successful.

The Incidence of Postpartum Hemorrhage in Pregnant Women with Placenta Previa: A Systematic Review and Meta-Analysis.

PubMed

Fan, Dazhi; Xia, Qing; Liu, Li; Wu, Shuzhen; Tian, Guo; Wang, Wen; Wu, Song; Guo, Xiaoling; Liu, Zhengping

2017-01-01

The global burden of postpartum hemorrhage (PPH) in women with placenta previa is a major public health concern. Although there are different reports on the incidence of PPH in different countries, to date, no research has reviewed them. The aim of this study was to calculate the average point incidence of PPH in women with placenta previa. A systematic review and meta-analysis of observational studies estimating PPH in women with placenta previa was conducted through literature searches in four databases in Jul 2016. This study was totally conducted according to the MOOSE guidelines and in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses standard. From 1148 obtained studies, 11 included in the meta-analysis, which involved 5146 unique pregnant women with placenta previa. The overall pooled incidence of PPH was 22.3% (95% CI 15.8-28.7%). In the subgroup, the prevalence was 27.4% in placenta previas, and was 14.5% in low-lying placenta previa; the highest prevalence was estimated in Northern America (26.3%, 95%CI 11.0-41.6%), followed by the Asia (20.7%, 95%CI 12.8-28.6%), Australia (19.2%, 95% CI 17.2-21.1%) and Europe (17.8%, 95% CI, 11.5%-24.0%). The summary estimate of the incidence of PPH among women with placenta previa was considerable in this systematic review. The results will be crucial in prevention, treatment, and identification of PPH among pregnant women with placenta previa and will be contributed to the planning and implantation of relevant public health strategies.

Placenta previa. A 13 years experience at a tertiary care center in Western Saudi Arabia.

PubMed

Abduljabbar, Hassan S; Bahkali, Nedaa M; Al-Basri, Samera F; Al Hachim, Estabrq; Shoudary, Ibrahim H; Dause, Wesam R; Mira, Mohammed Y; Khojah, Mohammed

2016-07-01

To review cases of placenta previa in the last 13 years in a tertiary teaching hospital to identify risk factors for maternal morbidity.  A retrospective analysis of all cases of placenta previa managed at King Abdulaziz University Hospital (KAUH), Jeddah, Kingdom of Saudi Arabia from January 2001 to December 2013.    The total number of deliveries was 55,862 deliveries, and 11,412 (20.3%) delivered by cesarean section (C/S). The charts of 230 cases diagnosed with placenta previa was reviewed, and different variables were collected and analyzed. Diagnoses were achieved in 94% of them using ultrasound. The prevalence rate of placenta previa was 4.1 per 1000 births. Cesarean section was carried out as an emergency procedure in 130 (56.5%) women and as elective in 100 (43.5%) women. Of them, 26 patients were admitted to the intensive care unit (ICU) (11.3%), all of which received blood transfusion >6 units and 22 patients had a hysterectomy for uncontrollable bleeding.   Placenta previa is one of the leading causes of maternal morbidity and mortality. Every hospital must have a protocol, or algorithm for the management of placenta previa. Risk factors for maternal morbidity included complete previa, history of previous C/S, emergency C/S at a gestational age of less than 36 weeks, and estimated blood loss more than 2000 ml.

Placenta previa and immediate outcome of the term offspring.

PubMed

Walfisch, Asnat; Sheiner, Eyal

2016-10-01

Immediate neonatal outcome in pregnancies complicated by placenta previa is largely dependent on gestational age. We aimed to investigate whether placenta previa increases the risk for perinatal mortality and immediate morbidity of the offspring born at term. A population-based cohort study included all singleton pregnancies, with and without placenta previa, delivered at term. Maternal and pregnancy characteristics as well as immediate neonatal morbidity and mortality were compared. Deliveries occurred between the years 1991-2013 in a tertiary medical center. Multiple pregnancies, and fetal congenital malformations were excluded. During the study period 233,123 consecutive term deliveries met the inclusion criteria; 0.2 % of the babies were born to mothers diagnosed with placenta previa. Women with placenta previa were significantly older and more likely to have had a previous cesarean section. Pregnancies were more likely to be complicated with pathological presentations and cesarean hysterectomies. Babies born at term following pregnancies with placenta previa were more likely to weigh less than 2500 g (OR 2.78 CI 1.9-3.9, p < 0.001). However, 5 min Apgar score and perinatal mortality rates were comparable between the groups. Neonatal outcomes remained comparable between the groups in a sub-analysis of cesarean deliveries only. Although placenta previa pregnancies involve higher maternal morbidity rates, term offsprings are not at an increased risk for immediate adverse outcome.

The effect of advanced maternal age on maternal and neonatal outcomes of placenta previa: A register-based cohort study.

PubMed

Roustaei, Zahra; Vehviläinen-Julkunen, Katri; Tuomainen, Tomi-Pekka; Lamminpää, Reeta; Heinonen, Seppo

2018-05-19

Advanced maternal age (AMA) at the time of delivery generally worsens obstetric outcomes, but its effects on specific pregnancy problems, such as placenta previa, have not been adequately assessed. Therefore, the objective of the study was to explore the effect of AMA on adverse maternal and neonatal outcomes among pregnancies complicated by placenta previa. The study was a register-based cohort study using data of three Finnish health registries, including information of 283 324 women and their newborns. Separate multivariable logistic regression modeling was performed for women under age 35 and women aged 35 or older to assess the association between placenta previa and adverse maternal and neonatal outcomes. Furthermore, interactions between maternal age and placenta previa were tested. A total of 283 324 deliveries of which 714 (0.3%) were complicated by placenta previa. Adverse maternal and neonatal outcomes increased in women with placenta previa, with different patterns across age groups. The adjusted odds ratios and 95% confidence intervals for AMA and young women with previa were 7.3 (5.0-10.6) and 6.8 (5.2-8.9) in blood transfusion, 11.3 (5.4-23.3) and 10.9 (6.1-19.6) in placental abruption. In neonatal outcomes the adjusted odds ratios for AMA and young women with placenta previa were 8.8 (6.6-11.6) and 11.7 (9.7-14.1) in preterm birth <37 weeks, 4.0 (3.0-5.3) and 4.9 (4.1-5.9) in neonatal intensive care unit (NICU) admission, 4.0 (2.8-5.7) and 5.9 (4.7-7.4) low birth weight <2500 g, 2.7 (1.5-4.9) and 3.3 (2.2-5.0) in low Apgar score at 5 min. The joint effects of maternal age and placenta previa on the risk of adverse maternal and neonatal outcomes were non-significant. The risk of adverse maternal and neonatal outcomes for women with placenta previa was not substantially affected by maternal age if their different risk profiles were taken into account. Copyright © 2018 Elsevier B.V. All rights reserved.

Efficacy and Safety of Prophylactic Uterine Artery Embolization in Pregnancy Termination with Placenta Previa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pei, Renguang, E-mail: mediprg@bjmu.edu.cn; Wang, Guoxiang; Wang, Heping

PurposeTo appraise the efficacy and safety of prophylactic uterine artery embolization in pregnancy termination with placenta previa.MethodsA cohort of 54 consecutive patients with placenta previa underwent prophylactic uterine artery embolization before vaginal delivery from February 2012 to March 2015. Vaginal delivery was attempted in all patients. Cesarean section or hysterectomy was introduced when vaginal delivery failed.ResultsVaginal delivery succeeded in 50 patients (93.6%) and failed in 4 patients (6.4%), thereupon converted to cesarean delivery. No patients resorted to hysterectomy. Six patients (11.1%) underwent blood transfusion. None of clinical characteristics, including maternal age, gestational age, history of abortion, history of cesarean delivery,more » and volume of vaginal bleeding, was significantly associated with complete placenta previa (P > 0.05). However, patients with complete placenta previa had a significantly lower successful rate of vaginal delivery than did patients without complete placenta previa (81 vs 100%, P = 0.038). The rate of complications was 3.7%. No major complications were observed.ConclusionUterine artery embolization is an effective and safe technique to assist pregnancy termination with placenta previa, which may lower the risk of cesarean section, hysterectomy, and blood transfusion.« less

Efficacy and Safety of Prophylactic Uterine Artery Embolization in Pregnancy Termination with Placenta Previa.

PubMed

Pei, Renguang; Wang, Guoxiang; Wang, Heping; Huang, Xinyu; Yan, Xiaoxing; Yang, Xiaohua

2017-03-01

To appraise the efficacy and safety of prophylactic uterine artery embolization in pregnancy termination with placenta previa. A cohort of 54 consecutive patients with placenta previa underwent prophylactic uterine artery embolization before vaginal delivery from February 2012 to March 2015. Vaginal delivery was attempted in all patients. Cesarean section or hysterectomy was introduced when vaginal delivery failed. Vaginal delivery succeeded in 50 patients (93.6%) and failed in 4 patients (6.4%), thereupon converted to cesarean delivery. No patients resorted to hysterectomy. Six patients (11.1%) underwent blood transfusion. None of clinical characteristics, including maternal age, gestational age, history of abortion, history of cesarean delivery, and volume of vaginal bleeding, was significantly associated with complete placenta previa (P > 0.05). However, patients with complete placenta previa had a significantly lower successful rate of vaginal delivery than did patients without complete placenta previa (81 vs 100%, P = 0.038). The rate of complications was 3.7%. No major complications were observed. Uterine artery embolization is an effective and safe technique to assist pregnancy termination with placenta previa, which may lower the risk of cesarean section, hysterectomy, and blood transfusion.

Frequency of placenta previa in previously scarred and non scarred uterus.

PubMed

Majeed, Tayyaba; Waheed, Fatima; Mahmood, Zahid; Saba, Kanwal; Mahmood, Hamis; Bukhari, Mulazim Hussain

2015-01-01

To determine the frequency of placenta Previa in patients coming to a tertiary care unit with previously scarred and non-scarred uterus. A descriptive cross sectional study was carried on 114 cases who underwent caesarean sections (37 cases out of 645 cases with non scarred uterus and 77 cases from 721 cases with scarred uterus) in the department of obstetrics and gynecology Lady Willingdon Hospital from January 2008- December 2011. Most patients (47.36%) were between 26-30 years age group, presented with gestational age between 36-40 weeks (70.17%), were mostly G2-4, while frequency of placenta Previa in non-scarred uterus was 32.45% (37 cases), and frequency in previously scarred uterus was 67.54% (77 cases). Major degree Previa was found in 88 cases (77.19%). There were 5.70% cases of placenta Previa from non-scarred uteruses and 10.67% cases of placenta Previa (10.67%) from already scarred uteruses. Stratification revealed a higher trend of the morbidity with the increase in number of previous caesarean sections. A significantly higher frequency of placenta Previa was found among patients coming to a tertiary care hospital with previously scarred uterus.

Risk Factors and Consequent Outcomes of Placenta Previa: Report From a Referral Center.

PubMed

Saleh Gargari, Soraya; Seify, Zahra; Haghighi, Ladan; Khoshnood Shariati, Maryam; Mirzamoradi, Masoumeh

2016-11-01

 Because of an unknown factor, the frequency of complicated pregnancy with placenta previa has been raised during past decade. This study was designed to deepen our understanding of risk factors and outcomes of placenta previa in our country. This study investigated 694 cases of placenta previa comparing with 600 healthy pregnant women with not overlie placenta in two referral and tertiary Obstetrics and Gynecological Hospital in Iran on the basis of the clinical and para-clinical analysis, in order to find the probable risk factors for occurrence of placenta previa and its effect on maternal and neonatal complications. The most important risk factor for the occurrence of placenta previa was advanced maternal age (P<0.001) and history of stillbirth (OR=117.2, CI=58.3-236.0). In the other hand, the most substantial outcome of this disorder was a reduction of gestational age (P<0.001) and low birth weight neonatally (P<0.001). The conservative follow-up should be programmed for women with placenta previa based on the type of risk factors which can provide the best possible management to decrease the morbidity and mortality of their related complications.

Increased expression of high mobility group box protein 1 and vascular endothelial growth factor in placenta previa.

PubMed

Xie, Han; Qiao, Ping; Lu, Yi; Li, Ying; Tang, Yuping; Huang, Yiying; Bao, Yirong; Ying, Hao

2017-12-01

Placenta previa is often associated with preterm delivery, reduced birth weight, a higher frequency of placental accreta and postpartum haemorrhage, and increased likelihood of blood transfusion. The present study aimed to examine the expression of high mobility group box protein 1 (HMGB1) in the placenta of women with or without placenta previa. The study group consisted of placental tissues obtained from women with or without placenta previa. The expression levels of HMGB1 and vascular endothelial growth factor (VEGF) were evaluated in the placental tissues using reverse transcription‑quantitative polymerase chain reaction, western blotting and immunohistochemistry. The mRNA expression levels of HMGB1 and VEGF were significantly increased in the placenta previa group compared with in the normal group. In addition, the placenta previa group exhibited increased HMGB1 and VEGF staining in vascular endothelial cells and trophoblasts. There were no significant differences in the expression of HMGB1 or VEGF between groups with or without placenta accreta or postpartum haemorrhage. The present study hypothesised that the increased expression of HMGB1 in the placenta may be associated with the pathogenesis of placenta previa by regulating the expression of the proangiogenic factor VEGF.

Frequency of placenta previa in previously scarred and non scarred uterus

PubMed Central

Majeed, Tayyaba; Waheed, Fatima; Mahmood, Zahid; Saba, Kanwal; Mahmood, Hamis; Bukhari, Mulazim Hussain

2015-01-01

Objective: To determine the frequency of placenta Previa in patients coming to a tertiary care unit with previously scarred and non-scarred uterus. Methods: A descriptive cross sectional study was carried on 114 cases who underwent caesarean sections (37 cases out of 645 cases with non scarred uterus and 77 cases from 721 cases with scarred uterus) in the department of obstetrics and gynecology Lady Willingdon Hospital from January 2008– December 2011. Results: Most patients (47.36%) were between 26-30 years age group, presented with gestational age between 36-40 weeks (70.17%), were mostly G2-4, while frequency of placenta Previa in non-scarred uterus was 32.45% (37 cases), and frequency in previously scarred uterus was 67.54% (77 cases). Major degree Previa was found in 88 cases (77.19%). There were 5.70% cases of placenta Previa from non-scarred uteruses and 10.67% cases of placenta Previa (10.67%) from already scarred uteruses. Stratification revealed a higher trend of the morbidity with the increase in number of previous caesarean sections. Conclusion: A significantly higher frequency of placenta Previa was found among patients coming to a tertiary care hospital with previously scarred uterus. PMID:26101491

Placenta previa and risk of major congenital malformations among singleton births in Finland.

PubMed

Kancherla, Vijaya; Räisänen, Sari; Gissler, Mika; Kramer, Michael R; Heinonen, Seppo

2015-06-01

Placenta previa has been associated with adverse birth outcomes, but its association with congenital malformations is inconclusive. We examined the association between placenta previa and major congenital malformations among singleton births in Finland. We performed a retrospective population register-based study on all singletons born at or after 22+0 weeks of gestation in Finland during 2000 to 2010. We linked three national health registers: the Finnish Medical Birth Register, the Hospital Discharge Register, and the Register of Congenital Malformations, and examined several demographic and clinical characteristics among women with and without placenta previa, in association with major congenital malformations. We estimated adjusted odds ratios and 95% confidence intervals using multivariable logistic regression models. The prevalence of placenta previa was estimated as 2.65 per 1000 singleton births in Finland (95% confidence interval, 2.53-2.79). Overall, 6.2% of women with placenta previa delivered a singleton infant with a major congenital malformation, compared with 3.8% of unaffected women (p ≤ 0.001). Placenta previa was positively associated with almost 1.6-fold increased risk of major congenital malformations in the offspring, after controlling for maternal age, parity, fetal sex, smoking, socio-economic status, chorionic villus biopsy, In vitro fertilization, pre-existing diabetes, depression, preeclampsia, and prior caesarean section (adjusted odds ratio = 1.55; 95% confidence interval, 1.27-1.90). Using a large population-based study, we found that placenta previa was weakly, but significantly associated with an increased risk of major congenital malformations in singleton births. Future studies should examine the association between placenta previa and individual types of congenital malformations, specifically in high-risk pregnancies. © 2015 Wiley Periodicals, Inc.

The Incidence of Postpartum Hemorrhage in Pregnant Women with Placenta Previa: A Systematic Review and Meta-Analysis

PubMed Central

Liu, Li; Wu, Shuzhen; Tian, Guo; Wang, Wen; Wu, Song; Guo, Xiaoling; Liu, Zhengping

2017-01-01

Background The global burden of postpartum hemorrhage (PPH) in women with placenta previa is a major public health concern. Although there are different reports on the incidence of PPH in different countries, to date, no research has reviewed them. Objective The aim of this study was to calculate the average point incidence of PPH in women with placenta previa. Methods A systematic review and meta-analysis of observational studies estimating PPH in women with placenta previa was conducted through literature searches in four databases in Jul 2016. This study was totally conducted according to the MOOSE guidelines and in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses standard. Results From 1148 obtained studies, 11 included in the meta-analysis, which involved 5146 unique pregnant women with placenta previa. The overall pooled incidence of PPH was 22.3% (95% CI 15.8–28.7%). In the subgroup, the prevalence was 27.4% in placenta previas, and was 14.5% in low-lying placenta previa; the highest prevalence was estimated in Northern America (26.3%, 95%CI 11.0–41.6%), followed by the Asia (20.7%, 95%CI 12.8–28.6%), Australia (19.2%, 95% CI 17.2–21.1%) and Europe (17.8%, 95% CI, 11.5%-24.0%). Conclusions The summary estimate of the incidence of PPH among women with placenta previa was considerable in this systematic review. The results will be crucial in prevention, treatment, and identification of PPH among pregnant women with placenta previa and will be contributed to the planning and implantation of relevant public health strategies. PMID:28107460

Prediction of maternal near-miss in placenta previa: a retrospective analysis from a tertiary center in Ankara, Turkey.

PubMed

Coskun, Bora; Akkurt, Iltac; Dur, Rıza; Akkurt, Mehmet O; Ergani, Seval Y; Turan, Ozerk T; Coskun, Bugra

2018-02-01

To determine risk factors for severe complications during and after cesarean delivery (CD) in placenta previa (PP). We reviewed retrospectively collected data from women with PP who underwent CD during a 6-year study period. We identified the complicated group based on the modified WHO near-miss criteria. Complicated and noncomplicated groups were compared considering clinical, laboratory, and sonographic features. Thirty-seven of 256 cases classified as near miss consisting of 14 peripartum hysterectomies, 12 uterine balloon placements, 10 great artery ligations, and four B-lynch suture placement procedures without maternal mortality. Perioperative complications included surgical wound infections (n = 5), bladder injury (n = 4), pelvic abscess (n = 1), and uterine rupture (n = 1). Logistic regression analyses demonstrated following features to be associated with maternal near miss in PP: (1) coexistent abruption (aOR 13.2, 95% CI 5.8-75.3), (2) morbidly adherent placenta (aOR 11.92, 95% CI 3.24-43.82), (3) number of hospitalizations for vaginal bleeding (≥3) (aOR 8.88, 95% CI 3.32-26.69), and (4) transvaginal cervical length (CL) measurement <10th percentile (aOR 5.5, 95% CI 2.1-15.4). Short cervical length, recurrent vaginal bleeding, morbidly adherent placenta, and concurrent placental abruption are independent predictors for subsequent severe maternal morbidity in PP cases. Early identification of these risk factors during PP follow-up may improve maternal outcome.

Transabdominal ultrasonography as a screening test for second-trimester placenta previa.

PubMed

Quant, Hayley S; Friedman, Alexander M; Wang, Eileen; Parry, Samuel; Schwartz, Nadav

2014-03-01

To determine the test characteristics of transabdominal ultrasonography as a screening test for second-trimester placenta previa. This secondary analysis of a prospective cohort study evaluated the distance from the placental edge to the internal os (placenta-cervix distance) through both transabdominal and transvaginal ultrasonography during the anatomic survey. Patients were recruited in the Maternal-Fetal Medicine Ultrasound Unit at the Hospital of the University of Pennsylvania, an urban tertiary care center. Transabdominal placenta-cervix distance cutoffs with high sensitivity for detection of previa and low-lying placenta were identified, and test characteristics were calculated. Follow-up ultrasound data, pregnancy, and delivery outcomes for those with second-trimester previa or low-lying placenta were obtained. One thousand two hundred fourteen women were included in the analysis. A transabdominal placenta-cervix distance cutoff of 4.2 cm was 93.3% sensitive and 76.7% specific for detection of previa with a 99.8% negative predictive value at a screen-positive rate of 25.0%. A cutoff of 2.8 cm was 86.7% sensitive and 90.5% specific with a 99.6% negative predictive value at a screen-positive rate of 11.4%. Only 9.8% (four of 41) of previas and low-lying placentas persisted through delivery. Transabdominal ultrasonography is an effective screening test for second-trimester placenta previa. At centers not performing universal transvaginal ultrasonography at the time of the anatomic survey, evidence-based transabdominal placenta-cervix distance cutoffs can optimize the identification of patients who require further surveillance for previa.

Preliminary experience in uterine artery embolization for second trimester pregnancy induced labor with complete placenta previa, placenta implantation, and pernicious placenta previa.

PubMed

Xie, L; Wang, Y; Man, Y C; Luo, F Y

2017-01-01

To explore the application of uterine artery embolization (UAE) in complete placenta previa, placenta implantation, and pernicious placenta previa during second trimester pregnancy induced labor. From April 2013 to April 2014, the present hospital admitted 12 cases of second-trimester complete placenta previa, placenta implantation, and pernicious placenta previa. Six of 12 cases at first were given UAE before cesarean section or labor induction. The other six cases, which were introduced into the present hospital after a failed embolization, underwent UAE, followed by hysteroscopy or curettage or laparotomy. None of the 12 patients underwent hysterectomy. The average blood loss of six patients with UAE was 383 ml and the average hospitalization was 8.66 days. While the remaining six patients without embolization in advance experienced 1,533 ml mean blood loss and 18 days in average stay. Among 12 patients, seven reported abdominal pain following embolization, four had a fever, and two had nausea and vomiting. Nine patients were followed-up and the menstrual cycles of seven returned to normal in one+ month, one in two+ months, and one suffered amenorrhea. Among the same nine patients, six menstruated regularly, two had menstrual disorders, and one had amenorrhea. No serious short- and long-term complications were observed. UAE is the safe method to avoid serious bleeding due to complete placenta previa, placenta implantation, and pernicious placenta previa with second-trimester pregnancy termination.

Corkscrew Collateral Vessels in Buerger Disease: Vasa Vasorum or Vasa Nervorum.

PubMed

Baş, Ahmet; Dikici, Atilla S; Gülşen, Fatih; Samancı, Cesur; Mihmanlı, İsmail; Beşirli, Kazım; Numan, Furuzan; Kantarci, Fatih

2016-05-01

To investigate the origin of "corkscrew" collateral vessels around the occluded popliteal artery in patients with Buerger disease by Doppler ultrasound (US) and magnetic resonance (MR) imaging in tandem with digital subtraction angiography (DSA). Between January 2013 and June 2015, 42 patients diagnosed with Buerger disease were identified retrospectively. Patients in whom occlusion of the popliteal artery was found on DSA of the lower extremity were subjected to Doppler US and MR imaging prospectively. Fifteen of 42 patients were identified as having the required characteristics, of whom 10 participated in the present study. Ten patients with occlusion of the popliteal artery were selected for inclusion, and 12 lower limbs of these patients were investigated. The study cohort comprised one woman and nine men with a mean age of 41 years ± 10 (standard deviation; range, 39-58 y). Corkscrew collateral vessels identified on DSA examinations were also identified on secondary imaging (Doppler US and MR imaging) in all patients except one in whom the popliteal artery was reconstituted after short-segment occlusion. The origin of the corkscrew collateral vessels was identified as the vasa nervorum of the tibial nerve in nine patients. Data from the present study suggest that corkscrew collateral vessels at the knee level in patients with Buerger disease originate from the vasa nervorum of the tibial nerve rather than the vasa vasorum of the popliteal artery if the latter is occluded. Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.

Expression of germline markers in three species of amphioxus supports a preformation mechanism of germ cell development in cephalochordates

PubMed Central

2013-01-01

Background In a previous study, we showed that the cephalochordate amphioxus Branchiostoma floridae has localized maternal transcripts of conserved germ cell markers Vasa and Nanos in its early embryos. These results provided strong evidence to support a preformation mechanism for primordial germ cell (PGC) development in B. floridae. Results In this study, we further characterize the expression of B. floridae homologs of Piwi and Tudor, which play important roles in germline development in diverse metazoan animals. We show that maternal mRNA of one of the identified Piwi-like homologs, Bf-Piwil1, also colocalizes with Vasa in the vegetal germ plasm and has zygotic expression in both the putative PGCs and the tail bud, suggesting it may function in both germline and somatic stem cells. More interestingly, one Tudor family gene, Bf-Tdrd7, is only expressed maternally and colocalizes with Vasa in germ plasm, suggesting that it may function exclusively in germ cell specification. To evaluate the conservation of the preformation mechanism among amphioxus species, we further analyze Vasa, Nanos, Piwil1, and Tdrd7 expression in two Asian amphioxus species, B. belcheri and B. japonicum. Their maternal transcripts all localize in similar patterns to those seen in B. floridae. In addition, we labeled putative PGCs with Vasa antibody to trace their dynamic distribution in developing larvae. Conclusions We identify additional germ plasm components in amphioxus and demonstrate the molecular distinction between the putative germline stem cells and somatic stem cells. Moreover, our results suggest that preformation may be a conserved mechanism for PGC specification among Branchiostoma species. Our Vasa antibody staining results suggest that after the late neurula stage, amphioxus PGCs probably proliferate with the tail bud cells during posterior elongation and are deposited near the forming myomere boundaries. Subsequently, these PGCs would concentrate at the ventral tip of the myoseptal walls to form the gonad anlagen. PMID:23777831

In Vitro Germ Cell Differentiation from Cynomolgus Monkey Embryonic Stem Cells

PubMed Central

Yamauchi, Kaori; Hasegawa, Kouichi; Chuma, Shinichiro; Nakatsuji, Norio; Suemori, Hirofumi

2009-01-01

Background Mouse embryonic stem (ES) cells can differentiate into female and male germ cells in vitro. Primate ES cells can also differentiate into immature germ cells in vitro. However, little is known about the differentiation markers and culture conditions for in vitro germ cell differentiation from ES cells in primates. Monkey ES cells are thus considered to be a useful model to study primate gametogenesis in vitro. Therefore, in order to obtain further information on germ cell differentiation from primate ES cells, this study examined the ability of cynomolgus monkey ES cells to differentiate into germ cells in vitro. Methods and Findings To explore the differentiation markers for detecting germ cells differentiated from ES cells, the expression of various germ cell marker genes was examined in tissues and ES cells of the cynomolgus monkey (Macaca fascicularis). VASA is a valuable gene for the detection of germ cells differentiated from ES cells. An increase of VASA expression was observed when differentiation was induced in ES cells via embryoid body (EB) formation. In addition, the expression of other germ cell markers, such as NANOS and PIWIL1 genes, was also up-regulated as the EB differentiation progressed. Immunocytochemistry identified the cells expressing stage-specific embryonic antigen (SSEA) 1, OCT-4, and VASA proteins in the EBs. These cells were detected in the peripheral region of the EBs as specific cell populations, such as SSEA1-positive, OCT-4-positive cells, OCT-4-positive, VASA-positive cells, and OCT-4-negative, VASA-positive cells. Thereafter, the effect of mouse gonadal cell-conditioned medium and growth factors on germ cell differentiation from monkey ES cells was examined, and this revealed that the addition of BMP4 to differentiating ES cells increased the expression of SCP1, a meiotic marker gene. Conclusion VASA is a valuable gene for the detection of germ cells differentiated from ES cells in monkeys, and the identification and characterization of germ cells derived from ES cells are possible by using reported germ cell markers in vivo, including SSEA1, OCT-4, and VASA, in vitro as well as in vivo. These findings are thus considered to help elucidate the germ cell developmental process in primates. PMID:19399191

The cervix as a natural tamponade in postpartum hemorrhage caused by placenta previa and placenta previa accreta: a prospective study.

PubMed

El Gelany, Saad A A; Abdelraheim, Ahmed R; Mohammed, Mo'men M; Gad El-Rab, Mohammed T; Yousef, Ayman M; Ibrahim, Emad M; Khalifa, Eissa M

2015-11-11

Placenta previa and placenta accreta carry significant maternal and fetal morbidity and mortality. Several techniques have been described in the literature for controlling massive bleeding associated with placenta previa cesarean sections. The objective of this study was to evaluate the efficacy and safety of the use of the cervix as a natural tamponade in controlling postpartum hemorrhage caused by placenta previa and placenta previa accreta. This prospective study was conducted on 40 pregnant women admitted to our hospital between June 2012 and November 2014. All participating women had one or more previous cesarean deliveries and were diagnosed with placenta previa and/or placenta previa accreta. Significant bleeding from the placental bed during cesarean section was managed by inverting the cervix into the uterine cavity and suturing the anterior and/or the posterior cervical lips into the anterior and/or posterior walls of the lower uterine segment. The technique of cervical inversion described above was successful in stopping the bleeding in 38 out of 40 patients; yielding a success rate of 95%. We resorted to hysterectomy in only two cases (5%). The mean intra-operative blood loss was 1572.5 mL, and the mean number of blood units transfused was 3.1. The mean time needed to perform the technique was 5.4 ± 0.6 min. The complications encountered were as follows: bladder injury in the two patients who underwent hysterectomy and wound infection in one patient. Postoperative fever that responded to antibiotics occurred in 1 patient. The mean duration of the postoperative hospital stay was 3.5 days This technique of using the cervix as a natural tamponade appears to be safe, simple, time-saving and potentially effective method for controlling the severe postpartum hemorrhage (PPH) caused by placenta previa/placenta previa accreta. This technique deserves to be one of the tools in the hands of obstetricians who face the life-threatening hemorrhage of placenta accreta. ClinicalTrials.gov NCT02590484 . Registered 28 October 2015.

Early preterm delivery due to placenta previa is an independent risk factor for a subsequent spontaneous preterm birth

PubMed Central

2012-01-01

Background To determine whether patients with placenta previa who delivered preterm have an increased risk for recurrent spontaneous preterm birth. Methods This retrospective population based cohort study included patients who delivered after a primary cesarean section (n = 9983). The rate of placenta previa, its recurrence, and the risk for recurrent preterm birth were determined. Results Patients who had a placenta previa at the primary CS pregnancy had an increased risk for its recurrence [crude OR of 2.65 (95% CI 1.3-5.5)]. The rate of preterm birth in patients with placenta previa in the primary CS pregnancy was 55.9%; and these patients had a higher rate of recurrent preterm delivery than the rest of the study population (p < .001). Among patients with placenta previa in the primary CS pregnancy, those who delivered preterm had a higher rate of recurrent spontaneous preterm birth regardless of the location of their placenta in the subsequent delivery [OR 3.09 (95% CI 2.1-4.6)]. In comparison to all patients with who had a primary cesarean section, patients who had placenta previa and delivered preterm had an independent increased risk for recurrent preterm birth [OR of 3.6 (95% CI 1.5-8.5)]. Conclusions Women with placenta previa, who deliver preterm, especially before 34 weeks of gestation, are at increased risk for recurrent spontaneous preterm birth regardless to the site of placental implantation in the subsequent pregnancy. Thus, strict follow up by high risk pregnancies specialist is recommended. PMID:22876799

Smoking and placenta previa: a meta-analysis.

PubMed

Shobeiri, Fatemeh; Jenabi, Ensiyeh

2017-12-01

Previous studies found a positive association between placenta previa and smoking during pregnancy. However, the results of these studies are inconsistent. The aim was to perform meta-analysis of the association between smoking during pregnancy and placenta previa. Major electronic databases, including PubMed, Web of Science, and Scopus were searched until June 2015. The heterogeneity across studies was explored by Q-test and I 2 statistic. The possibility of publication bias was assessed using Begg's and Egger's tests. The results were reported using odds ratio (OR) estimate with its 95% confidence intervals using a random-effects model. The literature search yielded 991 publications until October 2015 with 9,094,443 participants. Based on the random effect model, compared to nonsmoker women, the estimated OR and RR of placenta previa was 1.42 (95% CI: 1.30, 1.54) and 1.27 (95% CI: 1.18, 1.35), respectively. There is sufficient documents based on the observational studies that smoking during pregnancy is significantly associated with an increased risk of placenta previa. Therefore, smoking during pregnancy can be considered as a predictor of placenta previa.

The uterine leiomyoma and placenta previa: a meta-analysis.

PubMed

Jenabi, Ensiyeh; Fereidooni, Bita

2017-11-21

Some epidemiological studies have reported that uterine leiomyoma may increase the risk of placenta previa. To date, the meta-analysis has not been carried out for assessing the relationship between uterine leiomyoma and placenta previa. This meta-analysis was carried out to estimate the association between uterine leiomyoma and the risk of placenta previa. A systematic search was conducted out in major databases PubMed, Web of Science, and Scopus from the earliest possible year to June 2017. The heterogeneity across studies was explored by Q-test and I 2 statistic. The publication bias was assessed by Begg's and Egger's tests. The results were showed using odds ratio (OR) estimate with its 95% confidence intervals (CI) using a random-effects model. The literature search included 1218 articles until to June 2017 with 255,886 women. Based on OR estimates obtained from case-control and cohort studies, there was significant association between uterine leiomyoma and placenta previa in studies adjusted (2.21; 95%CI: 1.48, 2.94). We showed based on reports in observational studies that uterine leiomyoma is a risk factor for placenta previa in studies adjusted.

Placental pathologic changes and perinatal outcomes in placenta previa.

PubMed

Jung, Eun Jung; Cho, Hwa Jin; Byun, Jung Mi; Jeong, Dae Hoon; Lee, Kyung Bok; Sung, Moon Su; Kim, Ki Tae; Kim, Young Nam

2018-03-01

Placenta previa is a condition in which the placenta implants in the poorly vascularized lower uterine segment, which may result in inadequate uteroplacental perfusion, in turn, adversely affect the neonatal outcome. Abnormal placentation may also lead to severe postpartum hemorrhage as placenta separation proceeds. We aimed to evaluate the differences in placental histopathology and perinatal outcomes in pregnancies complicated with placenta previa and controls. We undertook a retrospective case-control study of 93 pregnancies with placenta previa and 81 controls between 2011 and 2017. Gross findings of the placenta showed that the placentas in placenta previa had significantly higher mean large chorionic plate diameters (18.5 ± 3.2 vs 17.5 ± 2.6 cm, P = .0298), chorionic plate areas (218.4 ± 62.9 cm 2 vs 198.7 ± 56.0 cm 2 , P = .0344), and marginal cord insertion (19.8% vs 8.6%, P = .0411) than control groups. Placental histopathological findings showed that placentas in placenta previa was significantly associated with maternal underperfusion, including villous infarction (50.5% vs 25.9%, P = .0009) and increased intervillous fibrin deposition (38.7% vs 7.4%, P < .0001). Also, women in the placenta previa group had a higher rate of abnormally invasive placenta and severe postpartum hemorrhage. However, placenta previa was not associated with the increased risk of neonatal mortality and morbidity. Abnormal placentation into the poorly vascularized lower uterine segment induces compensatory placental growth and increased surface area in response to reduced placental perfusion, which was consistent with the histopathological findings of coagulative necrosis of chorionic villi and fibrin deposition in the intervillous space. The morphological changes occurring in placenta previa may have important roles in maintaining adequate uteroplacental-fetal perfusion, which may prevent adverse neonatal outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Myomas and Adenomyosis: Impact on Reproductive Outcome.

PubMed

Vlahos, Nikos F; Theodoridis, Theodoros D; Partsinevelos, George A

2017-01-01

Among uterine structural abnormalities, myomas and adenomyosis represent two distinct, though frequently coexistent entities, with a remarkable prevalence in women of reproductive age. Various mechanisms have been proposed to explain the impact of each of them on reproductive outcome. In respect to myomas, current evidence implies that submucosal ones have an adverse effect on conception and early pregnancy. A similar effect yet is not quite clear and has been suggested for intramural myomas. Still, it seems reasonable that intramural myomas greater than 4 cm in diameter may negatively impair reproductive outcome. On the contrary, subserosal myomas do not seem to have a significant impact, if any, on reproduction. The presence of submucosal and/or large intramural myomas has also been linked to adverse pregnancy outcomes. In particular increased risk for miscarriage, fetal malpresentation, placenta previa, preterm birth, placenta abruption, postpartum hemorrhage, and cesarean section has been reported. With regard to adenomyosis, besides the tentative coexistence of adenomyosis and infertility, to date a causal relationship among these conditions has not been fully confirmed. Preterm birth and preterm premature rupture of membranes, uterine rupture, postpartum hemorrhage due to uterine atony, and ectopic pregnancy have all been reported in association with adenomyosis. Further research on the impact of adenomyosis on reproductive outcome is welcome.

Myomas and Adenomyosis: Impact on Reproductive Outcome

PubMed Central

Vlahos, Nikos F.; Theodoridis, Theodoros D.

2017-01-01

Among uterine structural abnormalities, myomas and adenomyosis represent two distinct, though frequently coexistent entities, with a remarkable prevalence in women of reproductive age. Various mechanisms have been proposed to explain the impact of each of them on reproductive outcome. In respect to myomas, current evidence implies that submucosal ones have an adverse effect on conception and early pregnancy. A similar effect yet is not quite clear and has been suggested for intramural myomas. Still, it seems reasonable that intramural myomas greater than 4 cm in diameter may negatively impair reproductive outcome. On the contrary, subserosal myomas do not seem to have a significant impact, if any, on reproduction. The presence of submucosal and/or large intramural myomas has also been linked to adverse pregnancy outcomes. In particular increased risk for miscarriage, fetal malpresentation, placenta previa, preterm birth, placenta abruption, postpartum hemorrhage, and cesarean section has been reported. With regard to adenomyosis, besides the tentative coexistence of adenomyosis and infertility, to date a causal relationship among these conditions has not been fully confirmed. Preterm birth and preterm premature rupture of membranes, uterine rupture, postpartum hemorrhage due to uterine atony, and ectopic pregnancy have all been reported in association with adenomyosis. Further research on the impact of adenomyosis on reproductive outcome is welcome. PMID:29234680

Risk of placenta previa in second birth after first birth cesarean section: a population-based study and meta-analysis

PubMed Central

2011-01-01

Background Objective: To compare the risk of placenta previa at second birth among women who had a cesarean section (CS) at first birth with women who delivered vaginally. Methods Retrospective cohort study of 399,674 women who gave birth to a singleton first and second baby between April 2000 and February 2009 in England. Multiple logistic regression was used to adjust the estimates for maternal age, ethnicity, deprivation, placenta previa at first birth, inter-birth interval and pregnancy complications. In addition, we conducted a meta-analysis of the reported results in peer-reviewed articles since 1980. Results The rate of placenta previa at second birth for women with vaginal first births was 4.4 per 1000 births, compared to 8.7 per 1000 births for women with CS at first birth. After adjustment, CS at first birth remained associated with an increased risk of placenta previa (odds ratio = 1.60; 95% CI 1.44 to 1.76). In the meta-analysis of 37 previously published studies from 21 countries, the overall pooled random effects odds ratio was 2.20 (95% CI 1.96-2.46). Our results from the current study is consistent with those of the meta-analysis as the pooled odds ratio for the six population-based cohort studies that analyzed second births only was 1.51 (95% CI 1.39-1.65). Conclusions There is an increased risk of placenta previa in the subsequent pregnancy after CS delivery at first birth, but the risk is lower than previously estimated. Given the placenta previa rate in England and the adjusted effect of previous CS, 359 deliveries by CS at first birth would result in one additional case of placenta previa in the next pregnancy. PMID:22103697

Placenta associated pregnancy complications in pregnancies complicated with placenta previa.

PubMed

Baumfeld, Yael; Herskovitz, Reli; Niv, Zehavi Bar; Mastrolia, Salvatore Andrea; Weintraub, Adi Y

2017-06-01

The purpose of our study was to examine the hypothesis that pregnancies complicated with placenta previa have an increased risk of placental insufficiency associated pregnancy complications (IUGR, preeclampsia, placental abruption and perinatal mortality). Our study included all deliveries that occurred at Soroka University Medical Center (Beer Sheva, Israel) between January 1998 and December 2013. Of them 1,249 were complicated by placenta previa and represented our study group. A composite outcome was created to include conditions associated with placental insufficiency. It included hypertensive disorders (i.e. gestational hypertension, mild and severe preeclampsia, HELLP and eclampsia), small for gestational age neonates and placental abruption. Patients with pregnancy complicated by placenta previa had significantly different obstetrical characteristics including bad obstetric history (8% vs. 4%, p < 0.001), recurrent abortions (11% vs. 5%, p < 0.001). Patients with placenta previa had higher rates of vaginal bleeding in the second half of pregnancy (3% vs. 0%, p < 0.001), gestational diabetes (8% vs. 5.5%, p < 0.001), placental abruption (10% vs. 1%, p < 0.001), adherent placenta (4% vs. 0.5%, p < 0.001), preterm delivery (52% vs. 8%, p < 0.001), with a median gestational age of 36 vs. 39 weeks, p < 0.001. The composite outcome was significantly more prevalent in the placenta previa group (21% vs. 13%, p < 0,001). Our study demonstrated an increased rate of placental insufficiency associated complications in women with placenta previa. This is of clinical relevance and suggests that a careful surveillance for women with placenta previa may help in minimizing maternal, fetal and neonatal complications. Copyright © 2017. Published by Elsevier B.V.

A combined ultrasound and clinical scoring model for the prediction of peripartum complications in pregnancies complicated by placenta previa.

PubMed

Yoon, So-Yeon; You, Ji Yeon; Choi, Suk-Joo; Oh, Soo-Young; Kim, Jong-Hwa; Roh, Cheong-Rae

2014-09-01

To generate a combined ultrasound and clinical model predictive for peripartum complications in pregnancies complicated by placenta previa. This study included 110 singleton pregnant women with placenta previa delivered by cesarean section (CS) from July 2011 to November 2013. We prospectively collected ultrasound and clinical data before CS and observed the occurrence of blood transfusion, uterine artery embolization and cesarean hysterectomy. We formulated a scoring model including type of previa (0: partials, 2: totalis), lacunae (0: none, 1: 1-3, 2: 4-6, 3: whole), uteroplacental hypervascularity (0: normal, 1: moderate, 2: severe), multiparity (0: no, 1: yes), history of CS (0: none, 1: once, 2: ≥ twice) and history of placenta previa (0: no, 1: yes) to predict the risk of peripartum complications. In our study population, the risk of perioperative transfusion, uterine artery embolization, and cesarean hysterectomy were 26.4, 1.8 and 6.4%, respectively. The type of previa, lacunae, uteroplacental hypervascularity, parity, history of CS, and history of placenta previa were associated with complications in univariable analysis. However, no factor was independently predictive for any complication in exact logistic regression analysis. Using the scoring model, we found that total score significantly correlated with perioperative transfusion, cesarean hysterectomy and composite complication (p<0.0001, Cochrane Armitage test). Notably, all patients with total score ≥7 needed cesarean hysterectomy. When total score was ≥6, three fourths of patients needed blood transfusion. This combined scoring model may provide useful information for prediction of peripartum complications in women with placenta previa. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Relationship between placenta location and resolution of second trimester placenta previa.

PubMed

Feng, Yun; Li, Xue-Yin; Xiao, Juan; Li, Wei; Liu, Jing; Zeng, Xue; Chen, Xi; Chen, Kai-Yue; Fan, Lei; Chen, Su-Hua

2017-06-01

This prospective study was conducted to assess the rate of resolution of second trimester placenta previa in women with anterior placenta and posterior placenta, and that in women with and without previous cesarean section. In this study, placenta previa was defined as a placenta lying within 20 mm of the internal cervical os or overlapping it. We recruited 183 women diagnosed with previa between 20 +0 weeks and 25 +6 weeks. They were grouped according to their placenta location (anterior or posterior) and history of cesarean section. Comparative analysis was performed on demographic data, resolution rate of previa and pregnancy outcomes between anterior group and posterior group, and on those between cesarean section group and non-cesarean section group. Women with an anterior placenta tended to be advanced in parity (P=0.040) and have increased number of dilatation and curettage (P=0.044). The women in cesarean section group were significantly older (P=0.000) and had more parity (P=0.000), gravidity (P=0.000), and dilatation and curettage (P=0.048) than in non-cesarean section group. Resolution of previa at delivery occurred in 87.43% women in this study. Women with a posterior placenta had a higher rate of resolution (P=0.030), while history of cesarean section made no difference. Gestational age at resolution was earlier in posterior group (P=0.002) and non-cesarean section group (P=0.008) than in anterior group and cesarean section group correspondingly. Placenta location and prior cesarean section did not influence obstetric outcomes and neonatal outcomes. This study indicates that it is more likely to have subsequent resolution of the previa when the placenta is posteriorly located for women who are diagnosed with placenta previa in the second trimester.

Improving the Accuracy of Diagnosing Placenta Previa on Transvaginal Ultrasound by Distinguishing between the Uterine Isthmus and Cervix: A Prospective Multicenter Observational Study.

PubMed

Hasegawa, Junichi; Kawabata, Ikuno; Takeda, Yoshiharu; Aoki, Hiroaki; Fukami, Takehiko; Tajima, Atsushi; Miyakoshi, Kei; Otsuki, Katsufumi; Shinozuka, Norio; Matsuda, Yoshio; Iwashita, Mitsutoshi; Okai, Takashi; Nakai, Akihito

2017-01-01

To clarify whether distinguishing between the uterine isthmus and cervix can improve the accuracy of diagnosing placenta previa at term. A multicenter prospective observational study was conducted among pregnant women with suspected placenta previa at 20-24 weeks' gestation. Subjects were divided into the open isthmus group and closed isthmus group. The accuracy of diagnosing placenta previa at term was compared between the 2 groups. We screened 9,341 patients, and 53 (0.6%) met the inclusion criteria. Nineteen cases with an open isthmus and 34 with a closed isthmus were followed. The accuracy for diagnosing placenta previa or a low-lying placenta at term was 94.7% in the open isthmus group and 26.5% in the closed isthmus group (p < 0.001). Elective or emergency Cesarean section was required in 100% of cases in the open isthmus group and 20.6% in the closed isthmus group (p < 0.001). A high prediction rate of placenta previa was obtained by using transvaginal ultrasound at 20-24 weeks' gestation after the isthmus opened by carefully distinguishing between the cervix and isthmus. © 2016 S. Karger AG, Basel.

Placenta previa associated with severe bleeding leading to hospitalization and delivery: a retrospective population-based cohort study.

PubMed

Mastrolia, Salvatore Andrea; Baumfeld, Yael; Loverro, Giuseppe; Yohai, David; Hershkovitz, Reli; Weintraub, Adi Yehuda

2016-11-01

The aim of our study was to compare maternal and neonatal outcomes in women with placenta previa complicated with severe bleeding leading to hospitalization until delivery versus those without severe bleeding episodes. This is a population-based retrospective cohort study including all pregnant women with placenta previa who delivered at our medical center in the study period, divided into the following groups: 1) women with severe bleeding leading to hospitalization resulting with delivery (n = 32); 2) patients with placenta previa without severe bleeding episodes (n = 1217). Out of all women with placenta previa who delivered at our medical center, 2.6% (32/1249) had an episode of severe bleeding leading to hospitalization and resulting with delivery. The rate of anemia was lower (43.8% versus 63.7%, p = 0.02) while the need for blood transfusion higher (37.5% versus 21.1%, p = 0.03) in the study group. The rate of cesarean sections was significantly different between the groups, and a logistic regression model was constructed in order to find independent risk factors for cesarean section in our patients. To the best of our knowledge, this is the first study to evaluate the impact of severe bleeding on the outcome of pregnancies complicated with placenta previa. Our study demonstrates that, in women with placenta previa, severe bleeding does not lead to increased adverse maternal or neonatal outcomes.

Placental histopathology lesions and pregnancy outcome in pregnancies complicated with symptomatic vs. non-symptomatic placenta previa.

PubMed

Weiner, Eran; Miremberg, Hadas; Grinstein, Ehud; Schreiber, Letizia; Ginath, Shimon; Bar, Jacob; Kovo, Michal

2016-10-01

The mechanisms involved in bleeding in cases of placenta previa (PP) and the effect on pregnancy outcome is unclear. We aimed to compare pregnancy outcome and placental histopathology in pregnancies complicated with symptomatic (bleeding) vs. non-symptomatic PP, and to study the effects of the co-existence of histopathological retro-placental hemorrhage (RPH) in cases of symptomatic PP on neonatal and maternal outcomes. Labor and maternal characteristics, neonatal outcome and placental histopathology lesions of pregnancies with PP, delivered between 24 and 42weeks, during 2009-2015, were reviewed. Results were compared between PP who had elective cesarean delivery (CD) (previa group) and PP with bleeding necessitating emergent CD (symptomatic previa group). Placental lesions were classified to lesions consistent with maternal malperfusion or fetal thrombo-occlusive disease (vascular and villous changes), and inflammatory lesions. Compared to the previa group (n=63), the symptomatic previa group (n=74) was characterized by older patients (p<0.001), higher rate of smokers (p=0.005), thrombophilia (p=0.038), and preterm deliveries (p<0.001). Placentas within the symptomatic previa group were smaller, with higher rates of weight<10th% (p=0.02), RPH (p<0.001) and villous changes related to maternal malperfusion (p=0.023). As compared to symptomatic PP without RPH, co-existence of RPH was associated with higher rate of adverse neonatal outcome (p<0.001) and maternal blood transfusion (p=0.02). On multivariate regression analysis, composite adverse neonatal outcome was found to be dependent on coexisting RPH (OR=2.8, 95%CI 1.2-11.7, p=0.03), and low gestational age (OR=3.1, 95%CI 1.6-4.9, p=0.02). Symptomatic placenta previa is associated with increased placental malperfusion lesions suggesting an association of maternal malperfusion with abnormal placental separation. The coexisting finding of RPH with symptomatic placenta previa can be seen as a marker for more extensive/severe placental separation, hence the association with maternal transfusion requirements and poorer fetal outcome. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Molecular Imaging of Vasa Vasorum Neovascularization via DEspR-targeted Contrast-enhanced Ultrasound Micro-imaging in Transgenic Atherosclerosis Rat Model

PubMed Central

Decano, Julius L.; Moran, Anne Marie; Ruiz-Opazo, Nelson; Herrera, Victoria L. M.

2011-01-01

Purpose Given that carotid vasa vasorum neovascularization is associated with increased risk for stroke and cardiac events, the present in vivo study was designed to investigate molecular imaging of carotid artery vasa vasorum neovascularization via target-specific contrast-enhanced ultrasound (CEU) micro-imaging. Procedures Molecular imaging was performed in male transgenic rats with carotid artery disease and non-transgenic controls using dual endothelin1/VEGFsp receptor (DEspR)-targeted microbubbles (MBD) and the Vevo770 micro-imaging system and CEU imaging software. Results DEspR-targeted CEU-positive imaging exhibited significantly higher contrast intensity signal (CIS)-levels and pre-/post-destruction CIS-differences in seven of 13 transgenic rats, in contrast to significantly lower CIS-levels and differences in control isotype-targeted microbubble (MBC)-CEU imaging (n =8) and in MBD CEU-imaging of five non-transgenic control rats (P<0.0001). Ex vivo immunofluorescence analysis demonstrated binding of MBD to DEspR-positive endothelial cells; and association of DEspR-targeted increased contrast intensity signals with DEspR expression in vasa vasorum neovessel and intimal lesions. In vitro analysis demonstrated dose-dependent binding of MBD to DEspR-positive human endothelial cells with increasing %cells bound and number of MBD per cell, in contrast to MBC or non-labeled microbubbles (P<0.0001). Conclusion In vivo DEspR-targeted molecular imaging detected increased DEspR-expression in carotid artery lesions and in expanded vasa vasorum neovessels in transgenic rats with carotid artery disease. Future studies are needed to determine predictive value for stroke or heart disease in this transgenic atherosclerosis rat model and translational applications. PMID:20972637

A Case of Vaginal Stillbirth in the Presence of Placenta Previa at 33 Weeks of Gestation

PubMed Central

Chinen, Yukiko; Kinjo, Tadatsugu; Nitta, Hayase; Kinjo, Yui; Masamoto, Hitoshi

2016-01-01

It was demonstrated that second- and third-trimester therapeutic termination of pregnancy (TOP) is feasible in cases with placenta previa. We report a 34-year-old woman with complex fetal malformations associated with placenta previa. An ultrasound examination at 21 weeks of gestation revealed fetal growth restriction (FGR) and complex fetal malformations associated with a placenta previa. After extensive information, the parents opted for careful observation. Thereafter, FGR gradually progressed and we observed arrest of end-diastolic velocity of the umbilical artery. Finally, intrauterine fetal death (IUFD) was confirmed at 33 weeks of gestation. Two days after IUFD, the patient experienced labor pain. The placenta and dead fetus weighing 961 g were vaginally delivered, and total bleeding was 270 mL. Although further studies to confirm the dynamic change of the uteroplacental blood flow are necessary to avoid the risk of maternal hemorrhage, vaginal TOP with placenta previa after feticide or IUFD would be feasible. PMID:27579202

Low Birth Weight: A Descriptive Study of Risk Factors

DTIC Science & Technology

1999-01-07

abruption Dx on admit MT Placenta previa Yes Placenta previa Dx complete/partial MT Smoking Yes Tobacco use this pregnancy MT Heavy alcohol use Yes...Multiple Gestation MT Urinary tract infection MT *Anemia MT Fetal anomalies MT Abruptio placentae MT Placenta previa MT Smoking MT Alcohol use...categories: (a) problems with the placenta , (b) problems with the pregnant woman herself, (c) problems with the fetus itself, or (d) any

ACCRETA COMPLICATING COMPLETE PLACENTA PREVIA IS CHARACTERIZED BY REDUCED SYSTEMIC LEVELS OF VASCULAR ENDOTHELIAL GROWTH FACTOR AND EPITHELIAL-TO-MESENCHYMAL TRANSITION OF THE INVASIVE TROPHOBLAST

PubMed Central

Wehrum, Mark J.; Buhimschi, Irina A.; Salafia, Carolyn; Thung, Stephen; Bahtiyar, Mert O.; Werner, Erica F.; Campbell, Katherine H.; Laky, Christine; Sfakianaki, Anna K.; Zhao, Guomao; Funai, Edmund F.; Buhimschi, Catalin S.

2011-01-01

OBJECTIVE To characterize serum angiogenic factor profile of women with complete placenta previa and determine if invasive trophoblast differentiation characteristic of accreta, increta or percreta shares features of epitehelial-mesenchymal-transition (EMT). STUDY DESIGN We analyzed gestational age matched serum samples from 90 pregnant women with either complete placenta previa (n=45) or uncomplicated pregnancies (n=45). Vascular-endothelial-growth-factor (VEGF), placental-growth-factor (PlGF) and soluble fms-like-tyrosine-kinase-1 (sFlt-1) were immunoassayed. VEGF and phosphotyrosine (P-Tyr) immunoreactivity was surveyed in histological specimens relative to expression of vimentin and cytokeratin-7. RESULTS Women with previa and invasive placentation [accreta (n=5); increta (n=6); percreta (n=2)] had lower systemic VEGF (invasive previa: median [IQR]: 0.8[0.02–3.4] vs. control: 6.5[2.7–10.5] pg/mL, P=0.02). VEGF and P-Tyr immunostaining predominated in the invasive extravillous trophoblasts (EVT) which co-expressed vimentin and cytokeratin-7, a EMT feature and tumor-like cell phenotype. CONCLUSIONS Lower systemic free VEGF and a switch of the interstitial EVT to a metastable cell phenotype characterize placenta previa with excessive myometrial invasion. PMID:21316642

Placenta previa and long-term morbidity of the term offspring.

PubMed

Walfisch, Asnat; Beharier, Ofer; Shoham-Vardi, Ilana; Sergienko, Ruslan; Landau, Daniella; Sheiner, Eyal

2016-08-01

The long-term impact of placenta previa on term infants is unknown. We aimed to investigate whether abnormal placentation increases the risk for long-term morbidity of the term offspring. A population-based cohort study compared the incidence of long-term hospitalizations up to the age of 18 due to cardiovascular, endocrine, neurological, hematological, respiratory and urinary morbidity of children born at term in pregnancies diagnosed with placenta previa and those without. Deliveries occurred between the years 1991-2013 in a tertiary medical center. Multiple pregnancies, and fetal congenital malformations were excluded. Kaplan-Meier survival curves were used to compare cumulative morbidity incidence over time. A multivariable generalized estimating equation (GEE) logistic regression model analysis was used to control for confounders and for maternal clusters. During the study period 233,123 term deliveries met the inclusion criteria; 0.2% (n=502) of the children were born to mothers with placenta previa. During the follow-up period, children born to mothers with placenta previa did not have an increased risk for long-term cardiovascular, endocrine, hematological, neurological, respiratory, and urinary morbidity. Term offsprings of mothers diagnosed with placenta previa do not appear to be at an increased risk for long-term morbidity up to the age of 18. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Increased Levels of Cell-Free Human Placental Lactogen mRNA at 28-32 Gestational Weeks in Plasma of Pregnant Women With Placenta Previa and Invasive Placenta

PubMed Central

Sekizawa, Akihiko; Ventura, Walter; Koide, Keiko; Hori, Kyouko; Okai, Takashi; Masashi, Yoshida; Furuya, Kenichi; Mizumoto, Yoshifumi

2014-01-01

We compared the levels of cell-free human placental lactogen (hPL) messenger RNA (mRNA) in maternal plasma at 28 to 32 weeks of gestation between women with diagnosis of placenta previa or invasive placenta and women with an uneventful pregnancy. Sensitivity and specificity of hPL mRNA for the prediction of invasive placenta were further explored. Plasma hPL mRNA were quantified by real-time reverse-transcriptase polymerase chain reaction in women with placenta previa (n = 13), invasive placenta (n = 5), and normal pregnancies (n = 92). Median (range) hPL mRNA was significantly higher in women with placenta previa, 782 (10-2301) copies/mL of plasma, and in those with invasive placenta, 615 (522-2102) copies/mL of plasma, when compared to normal pregnancies, 90 (4-4407) copies/mL of plasma, P < .01 and P < .05, respectively. We found a sensitivity of 100% and a specificity of 61.5% for the prediction of invasive placenta among women with placenta previa. In conclusion, expression of hPL mRNA is increased in plasma of women with placenta previa and invasive placenta at 28 to 32 weeks of gestation. PMID:23744883

Increased levels of cell-free human placental lactogen mRNA at 28-32 gestational weeks in plasma of pregnant women with placenta previa and invasive placenta.

PubMed

Kawashima, Akihiro; Sekizawa, Akihiko; Ventura, Walter; Koide, Keiko; Hori, Kyouko; Okai, Takashi; Masashi, Yoshida; Furuya, Kenichi; Mizumoto, Yoshifumi

2014-02-01

We compared the levels of cell-free human placental lactogen (hPL) messenger RNA (mRNA) in maternal plasma at 28 to 32 weeks of gestation between women with diagnosis of placenta previa or invasive placenta and women with an uneventful pregnancy. Sensitivity and specificity of hPL mRNA for the prediction of invasive placenta were further explored. Plasma hPL mRNA were quantified by real-time reverse-transcriptase polymerase chain reaction in women with placenta previa (n = 13), invasive placenta (n = 5), and normal pregnancies (n = 92). Median (range) hPL mRNA was significantly higher in women with placenta previa, 782 (10-2301) copies/mL of plasma, and in those with invasive placenta, 615 (522-2102) copies/mL of plasma, when compared to normal pregnancies, 90 (4-4407) copies/mL of plasma, P < .01 and P < .05, respectively. We found a sensitivity of 100% and a specificity of 61.5% for the prediction of invasive placenta among women with placenta previa. In conclusion, expression of hPL mRNA is increased in plasma of women with placenta previa and invasive placenta at 28 to 32 weeks of gestation.

Expression of nestin in embryonic tissues and its effects on clinicopathological characteristics of patients with placenta previa.

PubMed

Qiao, Yan-Yan; Chu, Ping

2018-02-01

In this study, we examined expression of nestin in the spinal cord, lung, kidney, stomach, colon, and intestine tissues at different stages of embryos in patients with placenta previa. Fetuses of 75 patients with placenta previa were assigned to case group and 80 fetuses from healthy pregnant women with normal placenta who voluntarily terminated pregnancy to control group. Clinical data of pregnant women were collected at the time of admission. Blood from elbow vein was collected to determine expression of serum nestin. Tissues from spinal cord, lung, kidney, stomach, colon, and intestine in 3-7 months fetuses of the two groups were extracted. Expression of nestin in tissues was detected by immunohistochemistry, Western blotting and RT-qPCR. The mRNA expression of nestin in the case group was increased. Nestin expression was correlated with the gestational age, age of foetus, and type of placenta previa in patients with placenta previa. Positive nestin expression was detected in the spinal cord, lung, kidney, stomach, intestine, and colon tissues in normal and placenta previa embryo at Stage I. The positive cell density and nestin expression decreased at Stage II, and further decreased at Stage III. The case group had higher nestin mRNA and protein levels throughout human fetal development. Findings of this study suggested that, nestin, as a specific marker of neural precursor cells, was expressed in various tissues of the embryo in patients with placenta previa and nestin expression was lower with increased maturation of the embryo. © 2017 Wiley Periodicals, Inc.

A 5-year review of pattern of placenta previa in Ilorin, Nigeria

PubMed Central

Omokanye, L. O.; Olatinwo, A. W. O.; Salaudeen, A. G.; Ajiboye, A. D.; Durowade, K. A.

2017-01-01

Background: Placenta previa, a major cause of obstetric hemorrhage, is potentially life-threatening to the mother and frequently results in high perinatal morbidity and mortality. Methodology: This is a retrospective study of all cases of placenta previa managed at the University of Ilorin Teaching Hospital over a 5-year from January 2011 to December 2015. A pro forma template was used to harvest information from case notes of patients involved in the study. Results: There were a total of 10,250 deliveries over the 5-year study and 164 cases of placenta previa were managed during this period; giving an incidence of 1.6% of the total deliveries. Of these patients, 65.9% were unbooked while 34.1% were booked. 110 (67%) were above 30 years of age and 51.2% were grand multiparous women. The majority (81.7%) of the patients belonged to the low socioeconomic class. Painless vaginal bleeding (62.2%), intrapartum hemorrhage (22.6%), and abnormal lie presentation (8.5%) were the most common mode of presentation. Vaginal delivery occurred in (29.3%) of patients while 70. 7% were delivered through cesarean section. There was a significant association between patients’ age, parity, booking status, and types of placenta previa (P < 0.05). Similarly, there was a significant association between gestational age at delivery, mode of delivery, intraoperative blood loss, and birth weight at delivery and types of placenta previa (P < 0.05). Perinatal mortality was 12.2%, 15.6% of babies had severe birth asphyxia, and there was no maternal mortality. Conclusion: From this study, the risk factors for placenta previa are advanced maternal age above 35 years, grand multiparity, and booking status. Early recognition, appropriate referral of these patients and availability of ultrasound facilities, blood transfusion facilities, improvement in neonatal facilities and trained personnel will go a long way in reducing the perinatal mortality from placenta previa. PMID:28539861

A 5-year review of pattern of placenta previa in Ilorin, Nigeria.

PubMed

Omokanye, L O; Olatinwo, A W O; Salaudeen, A G; Ajiboye, A D; Durowade, K A

2017-01-01

Placenta previa, a major cause of obstetric hemorrhage, is potentially life-threatening to the mother and frequently results in high perinatal morbidity and mortality. This is a retrospective study of all cases of placenta previa managed at the University of Ilorin Teaching Hospital over a 5-year from January 2011 to December 2015. A pro forma template was used to harvest information from case notes of patients involved in the study. There were a total of 10,250 deliveries over the 5-year study and 164 cases of placenta previa were managed during this period; giving an incidence of 1.6% of the total deliveries. Of these patients, 65.9% were unbooked while 34.1% were booked. 110 (67%) were above 30 years of age and 51.2% were grand multiparous women. The majority (81.7%) of the patients belonged to the low socioeconomic class. Painless vaginal bleeding (62.2%), intrapartum hemorrhage (22.6%), and abnormal lie presentation (8.5%) were the most common mode of presentation. Vaginal delivery occurred in (29.3%) of patients while 70. 7% were delivered through cesarean section. There was a significant association between patients' age, parity, booking status, and types of placenta previa ( P < 0.05). Similarly, there was a significant association between gestational age at delivery, mode of delivery, intraoperative blood loss, and birth weight at delivery and types of placenta previa ( P < 0.05). Perinatal mortality was 12.2%, 15.6% of babies had severe birth asphyxia, and there was no maternal mortality. From this study, the risk factors for placenta previa are advanced maternal age above 35 years, grand multiparity, and booking status. Early recognition, appropriate referral of these patients and availability of ultrasound facilities, blood transfusion facilities, improvement in neonatal facilities and trained personnel will go a long way in reducing the perinatal mortality from placenta previa.

vasa-related genes and their expression in stem cells of colonial parasitic rhizocephalan barnacle Polyascus polygenea (Arthropoda: Crustacea: Cirripedia: Rhizocephala).

PubMed

Shukalyuk, Andrey I; Golovnina, Kseniya A; Baiborodin, Sergei I; Gunbin, Konstantin V; Blinov, Alexander G; Isaeva, Valeria V

2007-02-01

vasa (vas)-related genes are members of the DEAD-box protein family and are expressed in the germ cells of many Metazoa. We cloned vasa-related genes (PpVLG, CpVLG) and other DEAD-box family related genes (PpDRH1, PpDRH2, CpDRH, AtDRHr) from the colonial parasitic rhizocephalan barnacle Polyascus polygenea, the non-colonial Clistosaccus paguri (Crustacea: Cirripedia: Rhizocephala), and the parasitic isopodan Athelgis takanoshimensis (Crustacea: Isopoda). The colonial Polyascus polygenea, a parasite of the coastal crabs Hemigrapsus sanguineus and Hemigrapsus longitarsis was used as a model object for further detailed investigations. Phylogenetic analysis suggested that PpVLG and CpVLG are closely related to vasa-like genes of other Arthropoda. The rest of the studied genes form their own separate branch on the phylogenetic tree and have a common ancestry with the p68 and PL10 subfamilies. We suppose this group may be a new subfamily of the DEAD-box RNA helicases that is specific for parasitic Crustacea. We found PpVLG and PpDRH1 expression products in stem cells from stolons and buds of internae, during asexual reproduction of colonial P. polygenea, and in germ cells from sexually reproducing externae, including male spermatogenic cells and female oogenic cells.

The risk of placental abruption and placenta previa in pregnant women with chronic hepatitis B viral infection: a systematic review and meta-analysis.

PubMed

Huang, Q T; Chen, J H; Zhong, M; Xu, Y Y; Cai, C X; Wei, S S; Hang, L L; Liu, Q; Yu, Y H

2014-08-01

Several epidemiological studies have found a positive association between chronic hepatitis B virus (CHB) infection and the risk of placental abruption and placenta previa, but various studies have reported conflicting findings. The objective was to systematically review the literature to determine a possible association between CHB infection and these two placental complications. We conducted a computerized search in electronic database through March 1, 2014, supplemented with a manual search of reference lists, to identify original published research on placental abruption and placenta previa rates in women with CHB infection. Data were independently extracted, and relative risks were calculated. The meta-analysis was performed using Stata version 10.0 software. Five studies involving 9088 placenta previa cases were identified. No significant association between CHB infection and placenta previa was identified (OR = 0.98, 95% CI = 0.60-1.62). Five studies involving 15571 placental abruption cases were identified. No significant association between CHB infection and placental abruption was identified (OR = 1.42, 95% CI, 0.93-2.15). The immune response against the virus represents a key factor in determining infection outcomes. No observation of significant increased risk of the placental complications could be partially explained by the complex immune response during CHB infection. Our meta-analysis found no evidence of significant associations between CHB infection and increased risk of placental abruption as well as placenta previa. Further well-designed studies were warranted to assess any potential association between CHB infection and increased risk of placental abruption as well as placenta previa. Copyright © 2014 Elsevier Ltd. All rights reserved.

The effect of placenta previa on fetal growth and pregnancy outcome, in correlation with placental pathology.

PubMed

Weiner, E; Miremberg, H; Grinstein, E; Mizrachi, Y; Schreiber, L; Bar, J; Kovo, M

2016-12-01

To compare the clinical characteristics and placental histopathology between pregnancies complicated by placenta previa and controls. Between 2009 and 2015, cesarean deliveries (CDs) of 119 pregnancies with placenta previa were identified from which maternal outcomes, neonatal outcomes and placental pathology were reviewed. Results were compared with CDs matched for maternal age and pregnancy complications (control group, n=119). Placental lesions were classified into maternal and fetal vascular supply lesions and inflammatory response. Composite neonatal outcome was defined as one or more of early neonatal complications. Small-for-gestational age (SGA) was defined as birth weight ⩽10th percentile. Placentas from the previa group had higher rates of weights <10th percentile (P<0.001) and of maternal and fetal vascular supply lesions (P<0.001, for both). Higher rate of SGA (P=0.003) and worse composite neonatal outcome (P<0.001) were also observed in the previa group as compared with controls. After controlling for potential confounding bias using multivariable logistic regression models, placenta previa remained statistically significantly associated with placental maternal (adjusted odds ratio (aOR) 2.48, 95% confidence interval (CI) 1.2-4.9, P=0.009) and fetal (aOR 7.05, 95% CI 2.4-20.2, P<0.001) vascular supply lesions, SGA (aOR 10, 95% CI 2.3-44.2, P=0.002) and adverse neonatal outcome (aOR 6.87, 95% CI 2.9-11.8, P<0.001). More placental vascular supply lesions, higher rate of SGA and worse neonatal outcome characterized pregnancies with placenta previa in the current study. These findings may suggest that abnormal placentation is accompanied by suboptimal implantation that interferes with fetal growth.

Validation of the Preverbal Visual Assessment (PreViAs) questionnaire.

PubMed

García-Ormaechea, Inés; González, Inmaculada; Duplá, María; Andres, Eva; Pueyo, Victoria

2014-10-01

Visual cognitive integrative functions need to be evaluated by a behavioral assessment, which requires an experienced evaluator. The Preverbal Visual Assessment (PreViAs) questionnaire was designed to evaluate these functions, both in general pediatric population or in children with high risk of visual cognitive problems, through primary caregivers' answers. We aimed to validate the PreViAs questionnaire by comparing caregiver reports with results from a comprehensive clinical protocol. A total of 220 infants (<2 years old) were divided into two groups according to visual development, as determined by the clinical protocol. Their primary caregivers completed the PreViAs questionnaire, which consists of 30 questions related to one or more visual domains: visual attention, visual communication, visual-motor coordination, and visual processing. Questionnaire answers were compared with results of behavioral assessments performed by three pediatric ophthalmologists. Results of the clinical protocol classified 128 infants as having normal visual maturation, and 92 as having abnormal visual maturation. The specificity of PreViAs questionnaire was >80%, and sensitivity was 64%-79%. More than 80% of the infants were correctly classified, and test-retest reliability exceeded 0.9 for all domains. The PreViAs questionnaire is useful to detect abnormal visual maturation in infants from birth to 24months of age. It improves the anamnesis process in infants at risk of visual dysfunctions. Copyright © 2014. Published by Elsevier Ireland Ltd.

Safety of cesarean delivery through placental incision in patients with anterior placenta previa.

PubMed

Hong, Deok-Ho; Kim, Eugene; Kyeong, Kyu-Sang; Hong, Seung Hwa; Jeong, Eun-Hwan

2016-03-01

To demonstrate the safety of fetal delivery through placental incision in a placenta previa pregnancy. We examined the medical records of 80 women with singleton pregnancy diagnosed with placenta previa who underwent cesarean section between May 2010 and May 2015 at the Department of Obstetrics and Gynecology, Chungbuk National University Hospital. Among the women with placenta previa, those who did not have the placenta in the uterine incision site gave birth via conventional uterine incision, while those with anterior placenta previa or had placenta attached to the uterine incision site gave birth via uterine incision plus placental incision. We compared the postoperative hemoglobin level and duration of hospital stay for the mother and newborn of the two groups. There was no difference between the placental incision group and non-incision group in terms of preoperative and postoperative hemoglobin change, the amount of blood transfusions required by the mother, newborns with 1-min or 5-min Apgar scores below 7 points or showing signs of acidosis on umbilical cord blood gas analysis result of pH below 7.20. Moreover, neonatal hemoglobin levels did not differ between the two groups. Fetal delivery through placental incision during cesarean section for placenta previa pregnancy does not negatively influence the prognosis of the mother or the newborn, and therefore, is considered a safe surgical technique.

Safety of cesarean delivery through placental incision in patients with anterior placenta previa

PubMed Central

Hong, Deok-Ho; Kim, Eugene; Kyeong, Kyu-Sang; Hong, Seung Hwa

2016-01-01

Objective To demonstrate the safety of fetal delivery through placental incision in a placenta previa pregnancy. Methods We examined the medical records of 80 women with singleton pregnancy diagnosed with placenta previa who underwent cesarean section between May 2010 and May 2015 at the Department of Obstetrics and Gynecology, Chungbuk National University Hospital. Among the women with placenta previa, those who did not have the placenta in the uterine incision site gave birth via conventional uterine incision, while those with anterior placenta previa or had placenta attached to the uterine incision site gave birth via uterine incision plus placental incision. We compared the postoperative hemoglobin level and duration of hospital stay for the mother and newborn of the two groups. Results There was no difference between the placental incision group and non-incision group in terms of preoperative and postoperative hemoglobin change, the amount of blood transfusions required by the mother, newborns with 1-min or 5-min Apgar scores below 7 points or showing signs of acidosis on umbilical cord blood gas analysis result of pH below 7.20. Moreover, neonatal hemoglobin levels did not differ between the two groups. Conclusion Fetal delivery through placental incision during cesarean section for placenta previa pregnancy does not negatively influence the prognosis of the mother or the newborn, and therefore, is considered a safe surgical technique. PMID:27004200

Prediction of adherent placenta in pregnancy with placenta previa using ultrasonography and magnetic resonance imaging.

PubMed

Tanimura, Kenji; Yamasaki, Yui; Ebina, Yasuhiko; Deguchi, Masashi; Ueno, Yoshiko; Kitajima, Kazuhiro; Yamada, Hideto

2015-04-01

Adherent placenta is a life-threatening condition in pregnancy, and is often complicated by placenta previa. The aim of this prospective study was to determine prenatal imaging findings that predict the presence of adherent placenta in pregnancies with placenta previa. The study included 58 consecutive pregnant women with placenta previa who underwent both ultrasonography and magnetic resonance imaging prenatally. Ultrasonographic findings of anterior placental location, grade 2 or higher placental lacunae (PL≥G2), loss of retroplacental hypoechoic clear zone (LCZ) and the presence of turbulent blood flow in the arteries were evaluated, in addition to MRI findings. Forty-three women underwent cesarean section alone; 15 women with adherent placenta underwent cesarean section followed by hysterectomy with pathological examination. To determine imaging findings that predict adherent placenta, univariate and multivariate logistic regression analyses were performed. Univariate logistic regression analyses demonstrated that anterior placental location, PL≥G2, LCZ, and MRI were associated with the presence of adherent placenta. Multivariate analyses revealed that LCZ (p<0.01, odds ratio 15.6, 95%CI 2.1-114.6) was a single significant predictor of adherent placenta in women with placenta previa. This prospective study demonstrated for the first time that US findings, especially LCZ, might be useful for identifying patients at high risk for adherent placenta among pregnant women with placenta previa. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Nestin is highly expressed in fetal spinal cord isolated from placenta previa patients and promotes inflammation by enhancing NF-κB activity.

PubMed

Li, Ling; Zhang, Jing; Gao, Huahe; Ma, Yuyan

2018-04-26

Purpose Nestin is expressed in various tissues of the embryo in patients with placenta previa, while the regulatory mechanism still unknown. Materials and methods All participants terminated pregnancy. Among them, 75 patients with placenta previa were assigned to the case group and 80 healthy pregnant women with normal placenta were assigned to the control group. Expression of nestin and CDK5 in fetal spinal cord tissues was detected by Western Blot and RT-qPCR methods. The enzyme-linked immunosorbent assay (ELISA) was used to determine the serum expression of some pro-inflammatory cytokines in placenta previa patients. The interaction between nestin and CDK5 was evaluated by immunoprecipitation and siRNA inhibition of nestin was performed to estimate its effect on NF-κB activity in fetal spinal cord tissues. Results Along with increased expression of nestin and CDK5 in fetal spinal cord tissues in the case group, IL-1β, IL-6, TNF-α, and IFN-γ were increased in the serum of placenta previa patients. siRNA inhibition analysis indicated that nestin interacted with CDK5 and regulated NF-κB activity in fetal spinal cord tissues. Conclusions Nestin is highly expressed and the interaction between nestin and CDK5 might lead to the progress of placenta previa through its regulation on NF-κB.

Expression of GFP under the control of the RNA helicase VASA permits fluorescence-activated cell sorting isolation of human primordial germ cells.

PubMed

Tilgner, Katarzyna; Atkinson, Stuart P; Yung, Sun; Golebiewska, Anna; Stojkovic, Miodrag; Moreno, Ruben; Lako, Majlinda; Armstrong, Lyle

2010-01-01

The isolation of significant numbers of human primordial germ cells at several developmental stages is important for investigations of the mechanisms by which they are able to undergo epigenetic reprogramming. Only small numbers of these cells can be obtained from embryos of appropriate developmental stages, so the differentiation of human embryonic stem cells is essential to obtain sufficient numbers of primordial germ cells to permit epigenetic examination. Despite progress in the enrichment of human primordial germ cells using fluorescence-activated cell sorting (FACS), there is still no definitive marker of the germ cell phenotype. Expression of the widely conserved RNA helicase VASA is restricted to germline cells, but in contrast to species such as Mus musculus in which reporter constructs expressing green fluorescent protein (GFP) under the control of a Vasa promoter have been developed, such reporter systems are lacking in human in vitro models. We report here the generation and characterization of human embryonic stem cell lines stably carrying a VASA-pEGFP-1 reporter construct that expresses GFP in a population of differentiating human embryonic stem cells that show expression of characteristic markers of primordial germ cells. This population shows a different pattern of chromatin modifications to those obtained by FACS enrichment of Stage Specific Antigen one expressing cells in our previous publication.

C-section

MedlinePlus

... part of the opening to the birth canal ( placenta previa ) Placenta separates from the uterine wall ( placenta abruptio ) ... future pregnancies. This includes a higher risk for: Placenta previa Placenta growing into the muscle of the uterus ...

Resolution of a Low-Lying Placenta and Placenta Previa Diagnosed at the Midtrimester Anatomy Scan.

PubMed

Durst, Jennifer K; Tuuli, Methodius G; Temming, Lorene A; Hamilton, Owen; Dicke, Jeffrey M

2018-02-05

To identify the incidence and resolution rates of a low-lying placenta or placenta previa and to assess the optimal time to perform follow-up ultrasonography (US) to assess for resolution. We conducted a retrospective cohort study of women with a diagnosis of a low-lying placenta or placenta previa at routine anatomic screening. Follow-up US examinations were reviewed to estimate the proportion of women who had resolution. A Kaplan-Meier survival curve was generated to estimate the median time to resolution. The distance of the placental edge from the internal cervical os was used to categorize the placenta as previa or low-lying (0.1-10 or ≥ 10-20 mm). A time-to-event analysis was used to estimate predictive factors and the time to resolution by distance from the os. A total of 1663 (8.7%) women had a diagnosis of a low-lying placenta or placenta previa. The cumulative resolution for women who completed 1 or more additional US examinations was 91.9% (95% confidence interval, 90.2%-93.3%). The median time to resolution was 10 (interquartile range [IQR], 7-13) weeks. The distance from the internal cervical os was known for 658 (51.0%) women. The probability of resolution was inversely proportional to the distance from the internal os: 99.5% (≥10-20 mm), 95.4% (0.1-10 mm), and 72.3% (placenta previa; P < .001). The median times to resolution were 9 (IQR, 7-12) weeks for 10 to 20 mm, 10 (IQR, 7-13) weeks for 0.1 to 10 mm, and 12 (IQR, 9-15) weeks for placenta previa (P = .0003, log rank test). A low-lying placenta or placenta previa diagnosed at the midtrimester anatomy survey resolves in most patients. Resolution is near universal in patients with an initial distance from the internal os of 10 mm or greater. © 2018 by the American Institute of Ultrasound in Medicine.

The cost-effectiveness of targeted or universal screening for vasa praevia at 18-20 weeks of gestation in Ontario.

PubMed

Cipriano, L E; Barth, W H; Zaric, G S

2010-08-01

To estimate the cost-effectiveness of targeted and universal screening for vasa praevia at 18-20 weeks of gestation in singleton and twin pregnancies. Cost-utility analysis based on a decision-analytic model comparing relevant strategies and life-long outcomes for mother and infant(s). Ontario, Canada. A cohort of pregnant women in 1 year. We constructed a decision-analytic model to estimate the lifetime incremental costs and benefits of screening for vasa praevia. Inputs were estimated from the literature. Costs were collected from the London Health Sciences Centre, the Ontario Health Insurance Program, and other sources. We used one-way, scenario and probabilistic sensitivity analysis to determine the robustness of the results. Incremental costs, life expectancy, quality-adjusted life-years (QALY) and incremental cost-effectiveness ratio (ICER). Universal transvaginal ultrasound screening of twin pregnancies has an ICER of $5488 per QALY-gained. Screening all singleton pregnancies with the risk factors low-lying placentas, in vitro fertilisation (IVF) conception, accessory placental lobes, or velamentous cord insertion has an ICER of $15,764 per QALY-gained even though identifying some of these risk factors requires routine use of colour Doppler during transabdominal examinations. Screening women with a marginal cord insertion costs an additional $27,603 per QALY-gained. Universal transvaginal screening for vasa praevia in singleton pregnancies costs $579,164 per QALY compared with targeted screening. Compared with current practice, screening all twin pregnancies for vasa praevia with transvaginal ultrasound is cost-effective. Among the alternatives considered, the use of colour Doppler at all transabdominal ultrasound examinations of singleton pregnancies and targeted use of transvaginal ultrasound for IVF pregnancies or when the placenta has been found to be associated with one or more risk factors is cost-effective. Universal screening of singleton pregnancies is not cost-effective compared with targeted screening.

Placenta previa and placental abruption after assisted reproductive technology in patients with endometriosis: a systematic review and meta-analysis.

PubMed

Gasparri, Maria Luisa; Nirgianakis, Konstantinos; Taghavi, Katayoun; Papadia, Andrea; Mueller, Michael D

2018-07-01

Recent evidence suggests that assisted reproductive technology (ART) increases the risk of adverse pregnancy outcomes, including placental disorders. Similarly, endometriosis resulted detrimental on placenta previa. However, up to 50% of women with endometriosis suffer from infertility, thus requiring ART. The aim of our metanalysis is to compare women with and without endometriosis undergoing ART in terms of placenta disorders events, to establish if ART itself or endometriosis, as an indication to ART, increases the risk of placenta previa. Literature searches were conducted in January 2018 using electronic databases (PubMed, Medline, Scopus, Embase, Science Direct, and the Cochrane Library Scopus). Series comparing pregnancy outcome after ART in women with and without endometriosis were screened and data on placenta previa and placental abruption were extracted. Five retrospective case-control studies met the inclusion criteria. The meta-analysis revealed that endometriosis is associated with an increased risk of placenta previa in pregnancies achieved through ART (OR 2.96 (95% CI 1.25-7.03); p = 0.01, I 2  =69%, random-effect model). No differences in placental abruption incidence were found (OR 0.44 (95% CI 0.10-1.87); p = 0.26, I 2  = 0%, fixed-effect model). Patients with endometriosis undergoing ART may have additional risk of placenta previa. Despite the inability to determine if endometriosis alone or endometriosis plus ART increase the risk, physicians should be aware of the potential additional risk that endometriosis patients undergoing ART harbor.

Comparison of transabdominal and transvaginal sonography in the diagnosis of placenta previa.

PubMed

Petpichetchian, Chusana; Pranpanus, Savitree; Suntharasaj, Thitima; Kor-Anantakul, Ounjai; Hanprasertpong, Tharangrut

2018-07-01

To compare the accuracies of transabdominal sonography (TAS) and transvaginal sonography (TVS) in the diagnosis of placenta previa. A prospective, cross-sectional study was conducted at a university hospital. Both TAS and TVS were performed on 81 pregnant women with a suspicion of placenta previa in the third trimester. The final diagnosis was confirmed at delivery. The agreement between the two ultrasound methods and the parameters of each method were calculated. Fifty-eight percent of the women had a placenta previa. The sensitivities of TAS and TVS were 86% (95% CI 78-94%) and 95% (95% CI 91-100%), respectively (p= 0.2). The specificity of both methods was 93% (95 CI 88-99%), and the overall accuracies of TAS and TVS were 89% (95% CI 82-96%) and 94% (95% CI 89-100%), respectively. When TAS was followed by TVS, 23% of the previous diagnoses were changed. The agreement between both methods was good (Kappa value = 0.7, 95%CI 0.55-0.86). For the diagnosis of placenta previa, TAS showed a high sensitivity and specificity, which were comparable to those of TVS. © 2018 Wiley Periodicals, Inc.

Pregnancy Complications: Placenta Previa

MedlinePlus

... half of pregnancy. Call your health care provider right away if you have vaginal bleeding anytime during your pregnancy. If the bleeding is severe, go to the hospital. Not all women with placenta previa have vaginal bleeding. In fact, ...

Prenatal ultrasound diagnosis and outcome of placenta previa accreta after cesarean delivery: a systematic review and meta-analysis.

PubMed

Jauniaux, Eric; Bhide, Amar

2017-07-01

Women with a history of previous cesarean delivery, presenting with a placenta previa, have become the largest group with the highest risk for placenta previa accreta. The objective of the study was to evaluate the accuracy of ultrasound imaging in the prenatal diagnosis of placenta accreta and the impact of the depth of villous invasion on management in women presenting with placenta previa or low-lying placenta and with 1 or more prior cesarean deliveries. We searched PubMed, Google Scholar, clinicalTrials.gov, and MEDLINE for studies published between 1982 and November 2016. Criteria for the study were cohort studies that provided data on previous mode of delivery, placenta previa, or low-lying placenta on prenatal ultrasound imaging and pregnancy outcome. The initial search identified 171 records, of which 5 retrospective and 9 prospective cohort studies were eligible for inclusion in the quantitative analysis. The studies were scored on methodological quality using the Quality Assessment of Diagnostic Accuracy Studies tool. The 14 cohort studies included 3889 pregnancies presenting with placenta previa or low-lying placenta and 1 or more prior cesarean deliveries screened for placenta accreta. There were 328 cases of placenta previa accreta (8.4%), of which 298 (90.9%) were diagnosed prenatally by ultrasound. The incidence of placenta previa accreta was 4.1% in women with 1 prior cesarean and 13.3% in women with ≥2 previous cesarean deliveries. The pooled performance of ultrasound for the antenatal detection of placenta previa accreta was higher in prospective than retrospective studies, with a diagnostic odds ratios of 228.5 (95% confidence interval, 67.2-776.9) and 80.8 (95% confidence interval, 13.0-501.4), respectively. Only 2 studies provided detailed data on the relationship between the depth of villous invasion and the number of previous cesarean deliveries, independently of the depth of the villous invasion. A cesarean hysterectomy was performed in 208 of 232 cases (89.7%) for which detailed data on management were available. Positive correlations were found in the largest prospective studies between the cumulative rates of the more invasive forms of accreta placentation and the sensitivity and specificity of ultrasound imaging but not with diagnostic odds ratio values. We found no data on the ultrasound screening of placenta accreta at the routine midtrimester ultrasound examination from the nonexpert ultrasound units. Planning individual management for delivery is possible only with accurate evaluation of prenatal risk of accreta placentation in women presenting with a low-lying placenta/previa and a history of prior cesarean delivery. Ultrasound is highly sensitive and specific in the prenatal diagnosis of accreta placentation when performed by skilled operators. Developing a prenatal screening protocol is now essential to further improve the outcome of this increasingly more common major obstetric complication. Copyright © 2017 Elsevier Inc. All rights reserved.

Relation between Birth Weight and Intraoperative Hemorrhage during Cesarean Section in Pregnancy with Placenta Previa

PubMed Central

Ishibashi, Hiroki; Takano, Masashi; Sasa, Hidenori; Furuya, Kenichi

2016-01-01

Background Placenta previa, one of the most severe obstetric complications, carries an increased risk of intraoperative massive hemorrhage. Several risk factors for intraoperative hemorrhage have been identified to date. However, the correlation between birth weight and intraoperative hemorrhage has not been investigated. Here we estimate the correlation between birth weight and the occurrence of intraoperative massive hemorrhage in placenta previa. Materials and Methods We included all 256 singleton pregnancies delivered via cesarean section at our hospital because of placenta previa between 2003 and 2015. We calculated not only measured birth weights but also standard deviation values according to the Japanese standard growth curve to adjust for differences in gestational age. We assessed the correlation between birth weight and the occurrence of intraoperative massive hemorrhage (>1500 mL blood loss). Receiver operating characteristic curves were constructed to determine the cutoff value of intraoperative massive hemorrhage. Results Of 256 pregnant women with placenta previa, 96 (38%) developed intraoperative massive hemorrhage. Receiver-operating characteristic curves revealed that the area under the curve of the combination variables between the standard deviation of birth weight and intraoperative massive hemorrhage was 0.71. The cutoff value with a sensitivity of 81.3% and specificity of 55.6% was −0.33 standard deviation. The multivariate analysis revealed that a standard deviation of >−0.33 (odds ratio, 5.88; 95% confidence interval, 3.04–12.00), need for hemostatic procedures (odds ratio, 3.31; 95% confidence interval, 1.79–6.25), and placental adhesion (odds ratio, 12.68; 95% confidence interval, 2.85–92.13) were independent risk of intraoperative massive hemorrhage. Conclusion In patients with placenta previa, a birth weight >−0.33 standard deviation was a significant risk indicator of massive hemorrhage during cesarean section. Based on this result, further studies are required to investigate whether fetal weight estimated by ultrasonography can predict hemorrhage during cesarean section in patients with placental previa. PMID:27902772

Relation between Birth Weight and Intraoperative Hemorrhage during Cesarean Section in Pregnancy with Placenta Previa.

PubMed

Soyama, Hiroaki; Miyamoto, Morikazu; Ishibashi, Hiroki; Takano, Masashi; Sasa, Hidenori; Furuya, Kenichi

2016-01-01

Placenta previa, one of the most severe obstetric complications, carries an increased risk of intraoperative massive hemorrhage. Several risk factors for intraoperative hemorrhage have been identified to date. However, the correlation between birth weight and intraoperative hemorrhage has not been investigated. Here we estimate the correlation between birth weight and the occurrence of intraoperative massive hemorrhage in placenta previa. We included all 256 singleton pregnancies delivered via cesarean section at our hospital because of placenta previa between 2003 and 2015. We calculated not only measured birth weights but also standard deviation values according to the Japanese standard growth curve to adjust for differences in gestational age. We assessed the correlation between birth weight and the occurrence of intraoperative massive hemorrhage (>1500 mL blood loss). Receiver operating characteristic curves were constructed to determine the cutoff value of intraoperative massive hemorrhage. Of 256 pregnant women with placenta previa, 96 (38%) developed intraoperative massive hemorrhage. Receiver-operating characteristic curves revealed that the area under the curve of the combination variables between the standard deviation of birth weight and intraoperative massive hemorrhage was 0.71. The cutoff value with a sensitivity of 81.3% and specificity of 55.6% was -0.33 standard deviation. The multivariate analysis revealed that a standard deviation of >-0.33 (odds ratio, 5.88; 95% confidence interval, 3.04-12.00), need for hemostatic procedures (odds ratio, 3.31; 95% confidence interval, 1.79-6.25), and placental adhesion (odds ratio, 12.68; 95% confidence interval, 2.85-92.13) were independent risk of intraoperative massive hemorrhage. In patients with placenta previa, a birth weight >-0.33 standard deviation was a significant risk indicator of massive hemorrhage during cesarean section. Based on this result, further studies are required to investigate whether fetal weight estimated by ultrasonography can predict hemorrhage during cesarean section in patients with placental previa.

VASA: Interactive Computational Steering of Large Asynchronous Simulation Pipelines for Societal Infrastructure.

PubMed

Ko, Sungahn; Zhao, Jieqiong; Xia, Jing; Afzal, Shehzad; Wang, Xiaoyu; Abram, Greg; Elmqvist, Niklas; Kne, Len; Van Riper, David; Gaither, Kelly; Kennedy, Shaun; Tolone, William; Ribarsky, William; Ebert, David S

2014-12-01

We present VASA, a visual analytics platform consisting of a desktop application, a component model, and a suite of distributed simulation components for modeling the impact of societal threats such as weather, food contamination, and traffic on critical infrastructure such as supply chains, road networks, and power grids. Each component encapsulates a high-fidelity simulation model that together form an asynchronous simulation pipeline: a system of systems of individual simulations with a common data and parameter exchange format. At the heart of VASA is the Workbench, a visual analytics application providing three distinct features: (1) low-fidelity approximations of the distributed simulation components using local simulation proxies to enable analysts to interactively configure a simulation run; (2) computational steering mechanisms to manage the execution of individual simulation components; and (3) spatiotemporal and interactive methods to explore the combined results of a simulation run. We showcase the utility of the platform using examples involving supply chains during a hurricane as well as food contamination in a fast food restaurant chain.

The Crystal Structure of the Drosophila Germline Inducer Oskar Identifies Two Domains with Distinct Vasa Helicase- and RNA-Binding Activities.

PubMed

Jeske, Mandy; Bordi, Matteo; Glatt, Sebastian; Müller, Sandra; Rybin, Vladimir; Müller, Christoph W; Ephrussi, Anne

2015-07-28

In many animals, the germ plasm segregates germline from soma during early development. Oskar protein is known for its ability to induce germ plasm formation and germ cells in Drosophila. However, the molecular basis of germ plasm formation remains unclear. Here, we show that Oskar is an RNA-binding protein in vivo, crosslinking to nanos, polar granule component, and germ cell-less mRNAs, each of which has a role in germline formation. Furthermore, we present high-resolution crystal structures of the two Oskar domains. RNA-binding maps in vitro to the C-terminal domain, which shows structural similarity to SGNH hydrolases. The highly conserved N-terminal LOTUS domain forms dimers and mediates Oskar interaction with the germline-specific RNA helicase Vasa in vitro. Our findings suggest a dual function of Oskar in RNA and Vasa binding, providing molecular clues to its germ plasm function. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Black carp vasa identifies embryonic and gonadal germ cells.

PubMed

Xue, Ting; Yu, Miao; Pan, Qihua; Wang, Yizhou; Fang, Jian; Li, Lingyu; Deng, Yu; Chen, Kai; Wang, Qian; Chen, Tiansheng

2017-07-01

Identification of molecular markers is an essential step in the study of germ cells. Vasa is an RNA helicase and a well-known germ cell marker that plays a crucial role in germ cell development. Here, we identified the Vasa homolog termed Mpvasa as the first germ cell marker in black carp (Mylopharyngodon piceus). First, a 2819-bp full-length Mpvasa complementary DNA (cDNA) was cloned by PCR using degenerated primers of conserved sequences and gene-specific primers. The Mpvasa cDNA sequence encodes a 637-amino acid protein that contains eight conserved characteristic motifs of the DEAD box protein family, and shares high identity to grass carp (81%) and zebrafish (74%) vasa homologs. Second, Mpvasa expression was restricted to the gonad in adulthood by RT-PCR and Western blot analysis. The dynamic patterns of temporal-spatial expression of Mpvasa during gametogenesis were examined by in situ hybridization, and Mpvasa transcripts were strictly detected in gonadal germ cells throughout oogenesis, predominantly in immature oocytes (stage I, II, and III oocytes). Third, Mpvasa transcripts were highly detected in unfertilized eggs and early embryos, and the signal indicated a dynamic migration of the primordial germ cells during embryogenesis, suggesting that Mpvasa transcripts were maternally inherited and specifically distributed in germ cells. Taken together, these results demonstrated that Mpvasa is an applicable molecular marker for identification of gonadal and embryonic germ cells, which facilitates the isolation and utilization of germ cells in black carp.

The value of ultrasound and magnetic resonance imaging in diagnostics and prediction of morbidity in cases of placenta previa with abnormal placentation.

PubMed

Algebally, Ahmed M; Yousef, Reda Ramadan Hussein; Badr, Sanaa Sayed Hussein; Al Obeidly, Amal; Szmigielski, Wojciech; Al Ibrahim, Abdullah A

2014-01-01

The purpose of the study was to evaluate the role of ultrasound (US) and magnetic resonance imaging (MRI) in the diagnostics and management of abnormal placentation in women with placenta previa and to compare the morbidity associated with that to placenta previa alone. The study includes 100 pregnant women with placenta previa with and without abnormal placentation. The results of MRI and US in abnormal placentation were compared with post-operative data. The patients' files were reviewed for assessment of operative and post-operative morbidity. The results of our statistical analysis were compared with data from the literature. US and MRI showed no significant difference in sensitivity and specificity in diagnosing abnormal placentation (97-100% and 94-100%, respectively). MRI was more sensitive than US for the detection of myometrial invasion and the type of abnormal placentation (73.5% and 47%, respectively). The difference between pre- and post-operative hemoglobin values and estimated blood loss were the most significant risk factors for abnormal placentation, added to risk factors known for placenta previa. Post-partum surgical complications and prolonged hospital stay were more common in the cases of placenta previa with abnormal placentation, however statistically insignificant. US and MRI are accurate imaging modalities for diagnosing abnormal placentation. MRI was more sensitive for the detection of the degree of placental invasion. The patient's morbidity increased in cases with abnormal placentation. There was no significant difference in post operative-complications and hospitalization time due to pre-operative planning when the diagnosis was established with US and MRI.

Prevalence of antepartum hemorrhage in women with placenta previa: a systematic review and meta-analysis

PubMed Central

Fan, Dazhi; Wu, Song; Liu, Li; Xia, Qing; Wang, Wen; Guo, Xiaoling; Liu, Zhengping

2017-01-01

Antepartum hemorrhage (APH) is an important cause of perinatal mortality and maternal morbidity in pregnant women with placenta previa in the world. However, the epidemiological characteristics are not completely understood. We performed an initial systematic review and meta-analysis to assess the prevalence of APH in pregnant women with placenta previa. It was totally performed following the Preferred Reporting Items for Systematic reviews and Meta-Analysis statement. PubMed, Elsevier Science Direct, and the Cochrane Library were searched before April 2016. A meta-analysis with a random-effects model based on a proportions approach was performed to determine the prevalence. Stratified analyses, meta-regression method, and sensitivity analysis were utilized to analyze the heterogeneity. A total of 29 articles were included. The pooled overall prevalence of APH among pregnant women with placenta previa was 51.6% (95% CI 42.7–60.6) in a heterogeneous set of studies (I2 = 97.9). Correlation analysis found that there was a positive correlation between prevalence and percentage of multiparous (r = 0.534, P = 0.027) and a negative correlation between prevalence and survey year (r = −0.400, P = 0.031). In conclusion, the prevalence of APH was a high condition among pregnant women with placenta previa. PMID:28067303

Conservative management of placenta previa complicated by abnormal placentation.

PubMed

Bręborowicz, Grzegorz H; Markwitz, Wiesław; Gaca, Michał; Koziołek, Agnieszka; Ropacka-Lesiak, Mariola; Dera, Anna; Brych, Mariusz; Szymankiewicz-Bręborowicz, Marta; Kruszyński, Grzegorz; Gruca-Stryjak, Karolina; Madejczyk, Mateusz; Szpera-Goździewicz, Agata; Krzyścin, Mariola

2013-07-01

Abnormal implantation of placenta previa is life-threatening condition. The purpose of this study was to evaluate the impact of the conservative management of pregnancies with such complication on maternal morbidity rate and the chance for uterine preservation (fertility). Eleven patients with abnormal implantation of placenta previa were analyzed prospectively. This complication was diagnosed antenatally by two-dimensional ultrasound and color flow Doppler. The following outcomes were analyzed: need for blood transfusion, admission and duration of stay in intensive care unit, infections, coagulopathies, time between cesarean section and delivery of placenta, hysterectomy and preservation of uterus. Among the 20 085 women who had a singleton gestation, 11 (0.054%) were identified with placenta previa with abnormal placentation. In five patients (group A), hysterectomy was performed because of hemorrhage or placenta ablation. In six patients (group B), conservative management succeeded and placenta were preserved. In group A, placenta were delivered earlier (2 d-8 weeks) in comparison with group B (6-15 weeks). Estimated blood loss during the delayed delivery of placenta was higher in the group with hysterectomy (respectively, 450-1600 and 300-500 ml). Conservative management of placenta previa with abnormal implantation decreases the risk of severe hemorrhage at the time of delivery and can preserve fertility.

The association of placenta previa and assisted reproductive techniques: a meta-analysis.

PubMed

Karami, Manoochehr; Jenabi, Ensiyeh; Fereidooni, Bita

2018-07-01

Several epidemiological studies have determined that assisted reproductive techniques (ART) can increase the risk of placenta previa. To date, only a meta-analysis has been performed for assessing the relationship between placenta previa and ART. This meta-analysis was conducted to estimate the association between placenta previa and ART in singleton and twin pregnancies. A literature search was performed in major databases PubMed, Web of Science, and Scopus from the earliest possible year to April 2017. The heterogeneity across studies was explored by Q-test and I 2 statistic. The publication bias was assessed using Begg's and Egger's tests. The results were reported using odds ratio (OR) and relative risk (RR) estimates with its 95% confidence intervals (CI) using a random-effects model. The literature search yielded 1529 publications until September 2016 with 1,388,592 participants. The overall estimate of OR was 2.67 (95%CI: 2.01, 3.34) and RR was 3.62 (95%CI: 0.21, 7.03) based on singleton pregnancies. The overall estimate of OR was 1.50 (95%CI: 1.26, 1.74) based on twin pregnancies. We showed based on odds ratio reports in observational studies that ART procedures are a risk factor for placenta previa.

The male reproductive system of Hippolyte inermis Leach 1815 (Decapoda, Caridea)

NASA Astrophysics Data System (ADS)

Cobos, Vanesa; Díaz, Vanessa; Raso, Jose Enrique García; Manjón-Cabeza, M. E.

2011-03-01

The present work completes a series of studies on the biology of the shrimp Hippolyte inermis Leach 1815, where we suggested the species to be gonochoristic. The morphology of the male reproductive system (testes, vasa deferentia, gonopores) and the different stages of male germ cell development are described for the first time in the genus Hippolyte, using TEM, SEM, and histological methods. All males from 1.70 to 3.42 mm in carapace length had active testes and well-developed vasa deferentia. No case of sex reversal could be found.

Antenatal Sonographic Diagnosis and Clinical Significance of Placenta Previa Accreta after Cesarean Section.

PubMed

Liu, Zhen-Zhen; Wei, Yao; Wang, Ruo-Jiao; Xu, Wen; Shi, Zhi-Min; Dai, Qing

2017-10-30

Objective To investigate the clinical and antenatal sonographic characteristics of placenta previa accreta after cesarean section. Methods The data of 21 inpatients diagnosed as placenta previa accreta after cesarean section in PUMC Hospital from 2006 to 2016 were retrospectively reviewed. The clinical and ultrasound features were recorded and compared among three placental accreta groups,including placenta accrete group(n=5),increta group(n=12),and percreta group(n=4). The relationship between the placental thickness at the uterine anterior lower segment level and the blood loss of the following cesarean section was tested. Results Of 21 patients,placenta previa was diagnosed by ultrasound in 20 cases(95.2%) and placenta previa accreta was diagnosed in 9 cases(42.9%). Antenatal ultrasound findings included following signs:loss of "clear zone"(15/18,83.3%),myometrial thinning(12/18,66.7%),abnormal placental lacunae(12/19,63.2%),bladder wall interruption(2/18,11.1%),and uterovesical hypervascularity(4/9,44.4%). Myometrial thinning(J-T=64.000,P=0.036),abnormal placental lacunae(J-T=74.500,P=0.032) and the placental thickness at the uterine anterior lower segment level(U=83.000,P=0.010) showed significant difference among different placenta accreta groups. Placental thickness at the uterine anterior lower segment level showed linear correlation with the blood loss of the following cesarean section(r=0.669,P=0.002). The blood loss of the following cesarean section showed significant difference among different placenta accreta groups(U=118.500,P=0.000). Conclusions The clinical and sonographic manifestations of placenta previa accreta after cesarean section show a spectrum of demographic characteristics. The measurement of thickness of placenta at the anterior lower segment may help the evaluation of the clinical prognosis of this special pathology.

Efficacy of Intrauterine Bakri Balloon Tamponade in Cesarean Section for Placenta Previa Patients.

PubMed

Cho, Hee Young; Park, Yong Won; Kim, Young Han; Jung, Inkyung; Kwon, Ja-Young

2015-01-01

The aims of this study were to analyze the predictive factors for the use of intrauterine balloon insertion and to evaluate the efficacy and factors affecting failure of uterine tamponade with a Bakri balloon during cesarean section for abnormal placentation. We reviewed the medical records of 137 patients who underwent elective cesarean section for placenta previa between July 2009 and March 2014. Cesarean section and Bakri balloon insertion were performed by a single qualified surgeon. The Bakri balloon was applied when blood loss during cesarean delivery exceeded 1,000 mL. Sixty-four patients (46.7%) required uterine balloon tamponade during cesarean section due to postpartum bleeding from the lower uterine segment, of whom 50 (78.1%) had placenta previa totalis. The overall success rate was 75% (48/64) for placenta previa patients. Previous cesarean section history, anterior placenta, peripartum platelet count, and disseminated intravascular coagulopathy all significantly differed according to balloon success or failure (all p<0.05). The drainage amount over 1 hour was 500 mL (20-1200 mL) in the balloon failure group and 60 mL (5-500 mL) in the balloon success group (p<0.01). Intrauterine tamponade with a Bakri balloon is an adequate adjunct management for postpartum hemorrhage following cesarean section for placenta previa to preserve the uterus. This method is simple to apply, non-invasive, and inexpensive. However, possible factors related to failure of Bakri balloon tamponade for placenta previa patients such as prior cesarean section history, anterior placentation, thrombocytopenia, presence of DIC at the time of catheter insertion, and catheter drainage volume more than 500 mL within 1 hour of catheter placement should be recognized, and the next-line management should be prepared in advance.

The Value of Ultrasound and Magnetic Resonance Imaging in Diagnostics and Prediction of Morbidity in Cases of Placenta Previa with Abnormal Placentation

PubMed Central

Algebally, Ahmed M.; Yousef, Reda Ramadan Hussein; Badr, Sanaa Sayed Hussein; Al Obeidly, Amal; Szmigielski, Wojciech; Al Ibrahim, Abdullah A.

2014-01-01

Summary Background The purpose of the study was to evaluate the role of ultrasound (US) and magnetic resonance imaging (MRI) in the diagnostics and management of abnormal placentation in women with placenta previa and to compare the morbidity associated with that to placenta previa alone. Material/Methods The study includes 100 pregnant women with placenta previa with and without abnormal placentation. The results of MRI and US in abnormal placentation were compared with post-operative data. The patients’ files were reviewed for assessment of operative and post-operative morbidity. The results of our statistical analysis were compared with data from the literature. Results US and MRI showed no significant difference in sensitivity and specificity in diagnosing abnormal placentation (97–100% and 94–100%, respectively). MRI was more sensitive than US for the detection of myometrial invasion and the type of abnormal placentation (73.5% and 47%, respectively). The difference between pre- and post-operative hemoglobin values and estimated blood loss were the most significant risk factors for abnormal placentation, added to risk factors known for placenta previa. Post-partum surgical complications and prolonged hospital stay were more common in the cases of placenta previa with abnormal placentation, however statistically insignificant. Conclusions US and MRI are accurate imaging modalities for diagnosing abnormal placentation. MRI was more sensitive for the detection of the degree of placental invasion. The patient’s morbidity increased in cases with abnormal placentation. There was no significant difference in post operative-complications and hospitalization time due to pre-operative planning when the diagnosis was established with US and MRI. PMID:25411586

Efficacy of Intrauterine Bakri Balloon Tamponade in Cesarean Section for Placenta Previa Patients

PubMed Central

Cho, Hee Young; Park, Yong Won; Kim, Young Han; Jung, Inkyung; Kwon, Ja-Young

2015-01-01

Purpose The aims of this study were to analyze the predictive factors for the use of intrauterine balloon insertion and to evaluate the efficacy and factors affecting failure of uterine tamponade with a Bakri balloon during cesarean section for abnormal placentation. Methods We reviewed the medical records of 137 patients who underwent elective cesarean section for placenta previa between July 2009 and March 2014. Cesarean section and Bakri balloon insertion were performed by a single qualified surgeon. The Bakri balloon was applied when blood loss during cesarean delivery exceeded 1,000 mL. Results Sixty-four patients (46.7%) required uterine balloon tamponade during cesarean section due to postpartum bleeding from the lower uterine segment, of whom 50 (78.1%) had placenta previa totalis. The overall success rate was 75% (48/64) for placenta previa patients. Previous cesarean section history, anterior placenta, peripartum platelet count, and disseminated intravascular coagulopathy all significantly differed according to balloon success or failure (all p<0.05). The drainage amount over 1 hour was 500 mL (20–1200 mL) in the balloon failure group and 60 mL (5–500 mL) in the balloon success group (p<0.01). Conclusion Intrauterine tamponade with a Bakri balloon is an adequate adjunct management for postpartum hemorrhage following cesarean section for placenta previa to preserve the uterus. This method is simple to apply, non-invasive, and inexpensive. However, possible factors related to failure of Bakri balloon tamponade for placenta previa patients such as prior cesarean section history, anterior placentation, thrombocytopenia, presence of DIC at the time of catheter insertion, and catheter drainage volume more than 500 mL within 1 hour of catheter placement should be recognized, and the next-line management should be prepared in advance. PMID:26263014

Complete Placenta Previa: Ultrasound Biometry and Surgical Outcomes

PubMed Central

Wortman, Alison C.; Schaefer, Stephanie L.; McIntire, Donald D.; Sheffield, Jeanne S.; Twickler, Diane M.

2018-01-01

Objective  To evaluate the relationship between surgical outcomes and ultrasound measurement of placental extension beyond the cervical os in women with placenta previa. Study Design  This is a retrospective cohort study of singleton pregnancies with placenta previa undergoing third-trimester ultrasound and delivering at our institution from 2002 through 2011. For study purposes, an investigator measured placental extension, defined as the placental distance from the internal os across the placenta continuing out to the lowest placental edge. If morbidly adherent placentation was suspected, women were excluded. Receiver operating characteristic (ROC) curves were developed for pertinent surgical outcomes, and multivariate analysis was performed to determine the placental extension with the best predictive discriminatory zone. Results  In total, 157 women had placenta previa, ultrasound, and delivery data: 86 (55%) had a placental extension of <40 mm, and 71 (45%) had a placental extension of ≥40 mm. Women with placental extension of ≥40 mm had increased surgical time, blood loss > 2,000 mL, blood transfusion, and rate of peripartum hysterectomy. After multivariate analysis, only peripartum hysterectomy and surgical time > 90 minutes remained significant, p ≤ 0.05 and p ≤ 0.01, respectively. Conclusion  In women with placenta previa, the placental extension ultrasound measurement of ≥40 mm is a predictor of adverse surgical outcomes. PMID:29686936

Acute and massive bleeding from placenta previa and infants' brain damage.

PubMed

Furuta, Ken; Tokunaga, Shuichi; Furukawa, Seishi; Sameshima, Hiroshi

2014-09-01

Among the causes of third trimester bleeding, the impact of placenta previa on cerebral palsy is not well known. To clarify the effect of maternal bleeding from placenta previa on cerebral palsy, and in particular when and how it occurs. A descriptive study. Sixty infants born to mothers with placenta previa in our regional population-based study of 160,000 deliveries from 1998 to 2012. Premature deliveries occurring at<26 weeks of gestation and placenta accreta were excluded. Prevalence of cystic periventricular leukomalacia (PVL) and cerebral palsy (CP). Five infants had PVL and 4 of these infants developed CP (1/40,000 deliveries). Acute and massive bleeding (>500g within 8h) occurred at around 30-31 weeks of gestation, and was severe enough to deliver the fetus. None of the 5 infants with PVL underwent antenatal corticosteroid treatment, and 1 infant had mild neonatal hypocapnia with a PaCO2 <25mmHg. However, none of the 5 PVL infants showed umbilical arterial acidemia with pH<7.2, an abnormal fetal heart rate monitoring pattern, or neonatal hypotension. Our descriptive study showed that acute and massive bleeding from placenta previa at around 30 weeks of gestation may be a risk factor for CP, and requires careful neonatal follow-up. The underlying process connecting massive placental bleeding and PVL requires further investigation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Complete Placenta Previa: Ultrasound Biometry and Surgical Outcomes.

PubMed

Wortman, Alison C; Schaefer, Stephanie L; McIntire, Donald D; Sheffield, Jeanne S; Twickler, Diane M

2018-04-01

Objective  To evaluate the relationship between surgical outcomes and ultrasound measurement of placental extension beyond the cervical os in women with placenta previa. Study Design  This is a retrospective cohort study of singleton pregnancies with placenta previa undergoing third-trimester ultrasound and delivering at our institution from 2002 through 2011. For study purposes, an investigator measured placental extension, defined as the placental distance from the internal os across the placenta continuing out to the lowest placental edge. If morbidly adherent placentation was suspected, women were excluded. Receiver operating characteristic (ROC) curves were developed for pertinent surgical outcomes, and multivariate analysis was performed to determine the placental extension with the best predictive discriminatory zone. Results  In total, 157 women had placenta previa, ultrasound, and delivery data: 86 (55%) had a placental extension of <40 mm, and 71 (45%) had a placental extension of ≥40 mm. Women with placental extension of ≥40 mm had increased surgical time, blood loss > 2,000 mL, blood transfusion, and rate of peripartum hysterectomy. After multivariate analysis, only peripartum hysterectomy and surgical time > 90 minutes remained significant, p ≤ 0.05 and p ≤ 0.01, respectively. Conclusion  In women with placenta previa, the placental extension ultrasound measurement of ≥40 mm is a predictor of adverse surgical outcomes.

Construction and histological analysis of a 3D human arterial wall model containing vasa vasorum using a layer-by-layer technique.

PubMed

Shima, Fumiaki; Narita, Hirokazu; Hiura, Ayami; Shimoda, Hiroshi; Akashi, Mitsuru

2017-03-01

There is considerable global demand for three-dimensional (3D) functional tissues which mimic our native organs and tissues for use as in vitro drug screening systems and in regenerative medicine. In particular, there has been an increasing number of patients who suffer from arterial diseases such as arteriosclerosis. As such, in vitro 3D arterial wall models that can evaluate the effects of novel medicines and a novel artificial graft for the treatment are required. In our previous study, we reported the rapid construction of 3D tissues by employing a layer-by-layer (LbL) technique and revealed their potential applications in the pharmaceutical fields and tissue engineering. In this study, we successfully constructed a 3D arterial wall model containing vasa vasorum by employing a LbL technique for the first time. The cells were coated with extracellular matrix nanofilms and seeded into a culture insert using a cell accumulation method. This model had a three-layered hierarchical structure: a fibroblast layer, a smooth muscle layer, and an endothelial layer, which resembled the native arterial wall. Our method could introduce vasa vasorum into a fibroblast layer in vitro and the 3D arterial wall model showed barrier function which was evaluated by immunostaining and transendothelial electrical resistance measurement. Furthermore, electron microscopy observations revealed that the vasa vasorum was composed of single-layered endothelial cells, and the endothelial tubes were surrounded by the basal lamina, which are known to promote maturation and stabilization in native blood capillaries. These models should be useful for tissue engineering, regenerative medicine, and pharmaceutical applications. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 814-823, 2017. © 2016 Wiley Periodicals, Inc.

Combining the auxin-inducible degradation system with CRISPR/Cas9-based genome editing for the conditional depletion of endogenous Drosophila melanogaster proteins.

PubMed

Bence, Melinda; Jankovics, Ferenc; Lukácsovich, Tamás; Erdélyi, Miklós

2017-04-01

Inducible protein degradation techniques have considerable advantages over classical genetic approaches, which generate loss-of-function phenotypes at the gene or mRNA level. The plant-derived auxin-inducible degradation system (AID) is a promising technique which enables the degradation of target proteins tagged with the AID motif in nonplant cells. Here, we present a detailed characterization of this method employed during the adult oogenesis of Drosophila. Furthermore, with the help of CRISPR/Cas9-based genome editing, we improve the utility of the AID system in the conditional elimination of endogenously expressed proteins. We demonstrate that the AID system induces efficient and reversible protein depletion of maternally provided proteins both in the ovary and the early embryo. Moreover, the AID system provides a fine spatiotemporal control of protein degradation and allows for the generation of different levels of protein knockdown in a well-regulated manner. These features of the AID system enable the unraveling of the discrete phenotypes of genes with highly complex functions. We utilized this system to generate a conditional loss-of-function allele which allows for the specific degradation of the Vasa protein without affecting its alternative splice variant (solo) and the vasa intronic gene (vig). With the help of this special allele, we demonstrate that dramatic decrease of Vasa protein in the vitellarium does not influence the completion of oogenesis as well as the establishment of proper anteroposterior and dorsoventral polarity in the developing oocyte. Our study suggests that both the localization and the translation of gurken mRNA in the vitellarium is independent from Vasa. © 2017 Federation of European Biochemical Societies.

Maternal plasma levels of cell-free β-HCG mRNA as a prenatal diagnostic indicator of placenta accrete.

PubMed

Zhou, J; Li, J; Yan, P; Ye, Y H; Peng, W; Wang, S; Wang, X Tong

2014-09-01

Several biomarkers, including maternal serum creatinine kinase and α-fetoprotein, have been described as potential tools for the diagnosis of placental abnormalities. This study aimed to determine whether maternal plasma mRNA levels of the β subunit of human chorionic gonadotropin (β-HCG) could predict placenta accreta prenatally. Sixty-eight singleton pregnant women with prior cesarean deliveries (CDs) were classified into three groups: normal placentation (35 women, control group); placenta previa alone (21 women, placenta previa group); and both placenta previa and placenta accreta (12 women, placenta previa/accreta group). Maternal plasma concentrations of cell-free β-HCG mRNA were measured by real-time reverse-transcription polymerase chain reaction and were expressed as multiples of the median (MoM). Cell-free β-HCG mRNA concentrations (MoM, range) were significantly higher in women with placenta accreta (3.65, 2.78-7.19) than in women with placenta previa (0.94, 0.00-2.97) or normal placentation (1.00, 0.00-2.69) (Steel-Dwass test, P < 0.01 and P < 0.01, respectively). In the placenta previa/accreta group, the concentration of cell-free β-HCG mRNA was significantly higher among women who underwent CDs with hysterectomy (4.41, 3.49-7.19) than among women whose CDs did not result in hysterectomy (3.20, 2.78-3.70) (Mann-Whitney U test, P = 0.012). An increased level of cell-free β-HCG mRNA in the maternal plasma of women with placenta accreta may arise from direct uteroplacental transfer of cell-free placental mRNA molecules. The concentration of cell-free β-HCG mRNA in maternal plasma may be applicable to the prenatal diagnosis of placenta accreta, especially to identify women with placenta accreta likely to require hysterectomy. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Severe Adverse Pregnancy Outcomes in Placenta Previa and Prior Cesarean Delivery].

PubMed

Zhou, Mi; Chen, Meng; Zhang, Li; He, Guo-Lin; He, Lei; Wei, Qiang; Li, Tao; Liu, Xing-Hui

2017-09-01

To investigate the severe adverse pregnancy outcomes in pregnancies with placenta previa and prior cesarean delivery and its risk factors. This retrospective casecontrol study reviewed all pregnancies with placenta previa and prior cesarean delivery delivered by repeat cesarean section in our institution between January 2005 and June 2015,and investigated the incidence of severe adverse pregnancy outcome. A composite of severe adverse pregnancy outcomes (including transfusion of 10 units or more red blood cells,maternal ICU admission,unanticipated injuries,repeat operation,hysterectomy,and maternal death) and other maternal and neonatal outcomes were described. Univariate and multivariable logistic regression analysis were used to quantify the effects of risk factors on severe adverse pregnancy outcomes. There were 478 women with placenta previa and prior cesarean delivery in our hospital over the last decade. The average age of them was 32.5±4.8 years old,most women were beyond 30 years old,the average gravidity and parity were 4 and 1,131 cases (27.4%) had severe adverse pregnancy outcomes. Transfusion of 10 units or more red blood cells happened in 75 cases (15.7%,75/478); 44 cases (9.2%,44/478) necessitated maternal ICU admission; unanticipated bladder injury occurred in 11 cases,but non ureter or bowel injury happened; All 4 repeat operations were due to delayed hemorrhage after conservative management during cesarean delivery,and an emergent hysterectomy was performed for all of the 4 cases. Hysterectomy (107 cases,22.4%) was the most common severe adverse pregnancy outcome. Among all 311 morbidly adherent placenta cases finally confirmed by pathological or surgical findings or both,only 172 (55.3%) were suspected before delivery. Multivariable logistic regression analysis showed that the risk of severe adverse pregnancy outcomes was significantly increased by pernicious placenta previa (i.e. anterior placenta overlying the prior cesarean scar),suspicion of morbidly adherent placenta before delivery and hemoglobin before delivery lower than 100 g/L,and the corresponding odds ratios and 95% confidence intervals were 2.4 (1.5-3.8),3.6 (2.3-5.6) and 2.5 (1.6-3.9),respectively. Pernicious placenta previa,suspicion of morbidly adherent placenta before delivery and hemoglobin before delivery lower than 100 g/L were associated with severe adverse pregnancy outcomes in women with placenta previa and prior cesarean delivery .

Obstetrical Complications in Women with Endometriosis: A Cohort Study in Japan

PubMed Central

Harada, Takashi; Taniguchi, Fuminori; Onishi, Kazunari; Kurozawa, Youichi; Hayashi, Kunihiko; Harada, Tasuku

2016-01-01

Background Endometriosis, which occurs in approximately 10% of women of reproductive age, is defined as the presence of endometrial tissue outside the uterus. Women with endometriosis are more likely to have difficulty conceiving and tend to receive infertility treatment, including assisted reproductive technology (ART) therapy. There has not yet been a prospective cohort study examining the effects of endometriosis on pregnancy outcome in pregnant Japanese women. Methodology This was a prospective cohort study of the incidence of obstetrical complications in women with endometriosis using data of the Japan Environment & Children’s Study (JECS). Included in this study were 9,186 pregnant women in the JECS with or without a history of endometriosis who gave birth or stillbirth or whose pregnancy was terminated with abortion between February and December 2011. Main Outcome Measures The effects of endometriosis on pregnancy outcome. Results Of the 9,186 pregnant women in the JECS, 4,119 (44.8%) had obstetrical complications; 330 participants reported a diagnosis of endometriosis before pregnancy, and these women were at higher risk for complications of pregnancy than those without a history of endometriosis (odds ratio (OR) = 1.50; 95% confidence interval (CI) 1.20 to 1.87). Logistic regression analyses showed that the adjusted OR for obstetrical complications of pregnant women who conceived naturally and had a history of endometriosis was 1.45 (CI 1.11 to 1.90). Among pregnant women with endometriosis, the ORs of preterm premature rupture of the membranes (PROM) and placenta previa were significantly higher compared with women never diagnosed with endometriosis who conceived naturally or conceived after infertility treatment, except for ART therapy (OR 2.14, CI 1.03–4.45 and OR 3.37, CI 1.32–8.65). Conclusions This study showed that endometriosis significantly increased the incidence of preterm PROM and placenta previa after adjusting for confounding of the data by ART therapy. PMID:28005934

PCR localization of C-type natriuretic peptide and B-type receptor mRNAs in rat nephron segments.

PubMed

Terada, Y; Tomita, K; Nonoguchi, H; Yang, T; Marumo, F

1994-08-01

The present study was undertaken to investigate the presence of C-type natriuretic peptide (CNP) mRNA and its receptor, natriuretic peptide B-type receptor (ANPR-B) mRNA, in rat renal structures. The microlocalization of mRNAs coding for CNP and ANPR-B was carried out in the rat kidney, using an assay of reverse transcription and polymerase chain reaction (RT-PCR) in individual microdissected renal tubule segments, glomeruli, vasa recta bundle, and arcuate arteries. The PCR signal for CNP was detected in glomerulus, vasa recta bundle, and arcuate artery. The PCR product of ANPR-B was widely present in renal structures. Relatively large amounts of ANPR-B PCR product were detected in glomerulus, vasa recta bundle, arcuate artery, and distal nephron segments. A relatively high concentration of CNP (10(-7) M) stimulated guanosine 3',5'-cyclic monophosphate accumulation in glomerulus, medullary thick ascending limb, cortical collecting duct, and inner medullary collecting duct. Our data demonstrate that CNP can be produced locally in the glomerulus and renal vascular system and that ANPR-B is widely distributed in renal structures. Thus CNP may influence renal function and act in autocrine and paracrine fashions in the kidney.

Outcome of delivery following first-pregnancy abortion.

PubMed

Tangtrakul, S; Thongjerm, M; Suthutvoravuth, S; Phromboon, S; Chaturachinda, K

1988-03-01

To determine whether or not a previous abortion has a deleterious effect on the outcome of a subsequent pregnancy, 6443 delivery records at Ramathibodi hospital between January and December 1982 were reviewed. The 2 study groups consisted of 143 women who had previously had an induced abortion and 315 women who had previously had a spontaneous abortion. Control groups were women having a 2nd child after a normal 1st pregnancy. The 1st study group had fewer women under 19 and over 35 and a lower educational level. Group 2 had more women with a pregnancy interval of less than 2 years. There was no difference between the study groups and the controls in premature rupture of fetal membranes, placenta previa, cesarean sections, manual removal of placenta, retained secundine, postpartum hemorrhage, low birth weight, Apgar score less than 6, congenital abnormalities, or perinatal mortality. The only difference between both study groups and the controls was that there was a higher percentage of assisted deliveries in both study groups. This finding is probably the result of the fact that these were 1st births and is totally unrelated to previous abortion.

Placenta Accreta and Total Placenta Previa in the 19th Week of Pregnancy

PubMed Central

Findeklee, S.; Costa, S. D.

2015-01-01

Placentation disorders are the result of impaired embedding of the placenta in the endometrium. The prevalence of these disorders is estimated to be around 0.3 %. A history of previous prior uterine surgery (especially cesarean section and curettage) is the most common risk factor. Impaired placentation is differentiated into deep placental attachment; marginal, partial and total placenta previa; and placenta accreta, increta and percreta. Treatment depends on the severity of presentation and ranges from expectant management to emergency hysterectomy. In most cases, preterm termination of pregnancy is necessary. We report here on the case of a 39-year-old woman with placenta accreta and total placenta previa who underwent hysterectomy in the 19th week of pregnancy. PMID:26366004

Conservative management of post-partum hemorrhage secondary to placenta previa-accreta with hypogastric artery ligation and endo-uterine hemostatic suture.

PubMed

Rauf, Melekoglu; Ebru, Celik; Sevil, Eraslan; Selim, Buyukkurt

2017-02-01

The aim of this study was to investigate maternal and neonatal outcomes of conservative management of post-partum hemorrhage due to placenta previa-accreta using hypogastric artery ligation and endo-uterine hemostatic suture to lower uterine segment. The records of 38 patients who were managed conservatively with hypogastric artery ligation and endo-uterine hemostatic suture to control post-partum hemorrhage secondary to placenta previa-accreta between April 2014 and January 2016, were reviewed retrospectively. Placenta previa-accreta was diagnosed according to gray-scale, color and 3-D power Doppler ultrasonography in addition to the intraoperative findings based on fragmentary or difficult separation of the placenta. In the case of conservative treatment protocol failure, cesarean hysterectomy was performed. Of these patients, 55.2% were between 25 and 35 years old; 97.5% were multiparous; 71.2% had two or more previous cesarean section and 68.5% had preterm delivery. Women with placenta accreta had a median estimated blood loss of 450 mL; 57.8% of patients had blood transfusion (mean intraoperative transfusion, 2 units packed red blood cells; range, 0-9 units). Median duration of operation was 112.5 min (range, 45-305 min) and 32 patients (84.3%) with placenta accreta did not undergo cesarean hysterectomy. Conservative treatment of post-partum hemorrhage secondary to placenta previa-accreta with hypogastric artery ligation and endo-uterine hemostatic sutures to the lower segment of the uterus is associated with lower hysterectomy rate compared with the other conservative methods reported in the literature. © 2016 Japan Society of Obstetrics and Gynecology.

Cervical varicosities may predict placenta accreta in posterior placenta previa: a magnetic resonance imaging study.

PubMed

Ishibashi, Hiroki; Miyamoto, Morikazu; Shinnmoto, Hiroshi; Murakami, Wakana; Soyama, Hiroaki; Nakatsuka, Masaya; Natsuyama, Takahiro; Yoshida, Masashi; Takano, Masashi; Furuya, Kenichi

2017-10-01

The aim of this study was to prenatally predict placenta accreta in posterior placenta previa using magnetic resonance imaging (MRI). This retrospective study was approved by the Institutional Review Board of our hospital. We identified 81 patients with singleton pregnancy who had undergone cesarean section due to posterior placenta previa at our hospital between January 2012 and December 2016. We calculated the sensitivity and specificity of several well-known findings, and of cervical varicosities quantified using magnetic resonance imaging, in predicting placenta accreta in posterior placenta previa. To quantify cervical varicosities, we calculated the A/B ratio, where "A" was the minimum distance from the most dorsal cervical varicosity to the deciduous placenta, and "B" was the minimum distance from the most dorsal cervical varicosity to the amniotic placenta. The appropriate cut-off value of the A/B ratio was determined using a receiver operating characteristic (ROC) curve. Three patients (3.7%) were diagnosed as having placenta accreta. The sensitivity and specificity of the well-known findings were 0 and 97.4%, respectively. Furthermore, the A/B ratio ranged from 0.02 to 0.79. ROC curve analysis revealed that the area under the combined placenta accreta and A/B ratio curve was 0.96. When the cutoff value of the A/B ratio was set 0.18, the sensitivity and specificity were 100 and 91%, respectively. It was difficult to diagnose placenta accreta in the posterior placenta previa using the well-known findings. The quantification of cervical varicosities could effectively predict placenta accreta.

Risk factors for massive postpartum bleeding in pregnancies in which incomplete placenta previa are located on the posterior uterine wall

PubMed Central

Lee, Hyun Jung; Lee, Young Jai; Ahn, Eun Hee; Kim, Hyeon Chul; Jung, Sang Hee; Chang, Sung Woon

2017-01-01

Objective To identify factors associated with massive postpartum bleeding in pregnancies complicated by incomplete placenta previa located on the posterior uterine wall. Methods A retrospective case-control study was performed. We identified 210 healthy singleton pregnancies with incomplete placenta previa located on the posterior uterine wall, who underwent elective or emergency cesarean section after 24 weeks of gestation between January 2006 and April 2016. The cases with intraoperative blood loss (≥2,000 mL) or transfusion of packed red blood cells (≥4) or uterine artery embolization or hysterectomy were defined as massive bleeding. Results Twenty-three women experienced postpartum profuse bleeding (11.0%). After multivariable analysis, 4 variables were associated with massive postpartum hemorrhage (PPH): experience of 2 or more prior uterine curettage (adjusted odds ratio [aOR], 4.47; 95% confidence interval [CI], 1.29 to 15.48; P=0.018), short cervical length before delivery (<2.0 cm) (aOR, 7.13; 95% CI, 1.01 to 50.25; P=0.049), fetal non-cephalic presentation (aOR, 12.48; 95% CI, 1.29 to 121.24; P=0.030), and uteroplacental hypervascularity (aOR, 6.23; 95% CI, 2.30 to 8.83; P=0.001). Conclusion This is the first study of cases with incomplete placenta previa located on the posterior uterine wall, which were complicated by massive PPH. Our findings might be helpful to guide obstetric management and provide useful information for prediction of massive PPH in pregnancies with incomplete placenta previa located on the posterior uterine wall. PMID:29184859

Risk factors for massive postpartum bleeding in pregnancies in which incomplete placenta previa are located on the posterior uterine wall.

PubMed

Lee, Hyun Jung; Lee, Young Jai; Ahn, Eun Hee; Kim, Hyeon Chul; Jung, Sang Hee; Chang, Sung Woon; Lee, Ji Yeon

2017-11-01

To identify factors associated with massive postpartum bleeding in pregnancies complicated by incomplete placenta previa located on the posterior uterine wall. A retrospective case-control study was performed. We identified 210 healthy singleton pregnancies with incomplete placenta previa located on the posterior uterine wall, who underwent elective or emergency cesarean section after 24 weeks of gestation between January 2006 and April 2016. The cases with intraoperative blood loss (≥2,000 mL) or transfusion of packed red blood cells (≥4) or uterine artery embolization or hysterectomy were defined as massive bleeding. Twenty-three women experienced postpartum profuse bleeding (11.0%). After multivariable analysis, 4 variables were associated with massive postpartum hemorrhage (PPH): experience of 2 or more prior uterine curettage (adjusted odds ratio [aOR], 4.47; 95% confidence interval [CI], 1.29 to 15.48; P =0.018), short cervical length before delivery (<2.0 cm) (aOR, 7.13; 95% CI, 1.01 to 50.25; P =0.049), fetal non-cephalic presentation (aOR, 12.48; 95% CI, 1.29 to 121.24; P =0.030), and uteroplacental hypervascularity (aOR, 6.23; 95% CI, 2.30 to 8.83; P =0.001). This is the first study of cases with incomplete placenta previa located on the posterior uterine wall, which were complicated by massive PPH. Our findings might be helpful to guide obstetric management and provide useful information for prediction of massive PPH in pregnancies with incomplete placenta previa located on the posterior uterine wall.

Placenta previa without morbidly adherent placenta: comparison of characteristics and outcomes between planned and emergent deliveries in a tertiary center.

PubMed

Erfani, Hadi; Kassir, Elias; Fox, Karin A; Clark, Steven L; Karbasian, Niloofar; Salmanian, Bahram; Shamshirsaz, Amir A; Espinoza, Jimmy; Nassr, Ahmed A; Eppes, Catherine S; Belfort, Michael A; Shamshirsaz, Alireza A

2017-11-05

The objective of this study is to compare patient outcomes between planned and emergent cesarean deliveries for placenta previa without morbidly adherent placenta. All patients with confirmed, persistent placenta previa (without morbidly adherent placentation) who underwent the surgery between January 2010 and April 2016 were included in this retrospective study. Primary outcome was composite maternal morbidity defined as the presence of at least one of the followings: death, red blood cell (RBC) transfusion, hysterectomy, reoperation, hospital stay >7 d, ureteral injury, bowel injury, or cystotomy. Three hundred and four patients with placenta previa were identified during the study period, of whom 154 (50.65%) had an antenatal and 10 (3.28%) had an intraoperative diagnosis of morbidly adherent placenta. One hundred and forty patients met the inclusion criteria. Eighty (57.1%) underwent planned cesarean delivery (planned cesarean delivery (PCD) group), and 60 (42.8%) required emergent cesarean delivery due to uterine contractions and/or bleeding (emergent cesarean delivery (ECD) group). Baseline characteristics were similar between the two groups except for the gestational age at delivery (36.0 weeks (36.0, 37.0) in PCD versus 34.0 weeks (32.0, 36.0) in ECP, p < .001). Composite maternal morbidity was not significantly different between two groups: 11 (18.3%) in ECD and 10 (12.5%) in PCD (p = .35) Conclusions: In our referral tertiary centre, emergent and planned cesarean deliveries for placenta previa without morbidly adherent placenta have similar maternal outcomes. In patients without significant hemorrhage, delivery may be safely deferred until 36-37 weeks.

Effect of routine rapid insertion of Bakri balloon tamponade on reducing hemorrhage from placenta previa during and after cesarean section.

PubMed

Soyama, Hiroaki; Miyamoto, Morikazu; Sasa, Hidenori; Ishibashi, Hiroki; Yoshida, Masashi; Nakatsuka, Masaya; Takano, Masashi; Furuya, Kenichi

2017-09-01

To evaluate the effectiveness of routine rapid insertion of a Bakri balloon during cesarean section for placenta previa based on a retrospective control study. Women with singleton pregnancies who underwent cesarean section for placenta previa at our institution between 2003 and 2016 were enrolled. Between 2015 and 2016, women who routinely underwent balloon tamponade during cesarean section were defined as the balloon group. Between 2003 and 2014, women who underwent no hemostatic procedures except balloon tamponade were defined as the non-balloon group. The clinical outcomes of the two groups were retrospectively analyzed. Of the 266 women with placenta previa, 50 were in the balloon group and 216 were in the non-balloon group. The bleeding amounts were significantly smaller in the balloon group than in the non-balloon group: intraoperative bleeding (991 vs. 1250 g, p < 0.01), postoperative bleeding (62 vs. 150 g, p < 0.01), and total bleeding (1066 vs. 1451 g, p < 0.01). Furthermore, the mean surgical duration was shorter in the balloon group than the non-balloon group (30 vs. 50 min, p < 0.01). In the balloon group, five patients suffered from increasing hemorrhage due to prolapse of the balloon from the uterus after the operation, but the hemorrhage was controlled by balloon re-insertion without additional hemostatic procedures. This study demonstrated that the routine rapid insertion of Bakri balloon tamponade during cesarean section significantly decreased intra- and postoperative hemorrhage and shortened the surgical duration in women with placenta previa.

Development of the Preverbal Visual Assessment (PreViAs) questionnaire.

PubMed

Pueyo, Victoria; García-Ormaechea, Inés; González, Inmaculada; Ferrer, Concepción; de la Mata, Guillermo; Duplá, María; Orós, Pedro; Andres, Eva

2014-04-01

Visual cognitive functions of preverbal infants are evaluated by means of a behavioral assessment. Parents or primary caregivers may be appropriate to certify the acquisition of certain abilities. To develop the PreViAs (Preverbal Visual Assessment) questionnaire to assess visual behavior of infants under 24 months of age and to assess the normative outcomes for each item at each age. The process was divided into three phases: scale development (items and domains generation), pilot testing, and exploratory analysis. The final version of the PreViAs questionnaire consisted of 30 items, each related to one or more of four domains (visual attention, visual communication, visual-motor coordination, and visual processing). For the exploratory analysis, 298 children (159 boys and 139 girls) were recruited. Their ages ranged from 0.1 to 24 months (mean, 11.2 months). Internal consistency of the questionnaire was high for all domains (Cronbach's α coefficients of 0.85-0.94). The PreViAs questionnaire is a useful scale for assessing visual cognitive abilities of infants under 24 months of age. It is easy and feasible to complete by primary caregivers. Copyright © 2014 Elsevier Ltd. All rights reserved.

Association of Placenta Previa with a History of Previous Cesarian Deliveries and Indications for a Possible Role of a Genetic Component

PubMed Central

M, Matalliotakis; A, Velegrakis; GN, Goulielmos; E, Niraki; AE, Patelarou; I, Matalliotakis

2017-01-01

Abstract A prior Cesaria section (C-section) is an important risk factor that leads to endometrial damage and abnormal implantation of the placenta. Our retrospective study aims to correlate the frequency of placenta previa to previous C-sections, to determine the effect of male gender in this condition and to evaluate further the maternal outcome. Seventy-six cases with placenta previa were selected out of 5200 live births. Diagnosis was confirmed by ultrasound and in the operating theater. In the 76 women examined, we found 50 cases with a history of a previous C-section (66.0%) and 49 male offspring (65.0%) (p <0.001), with a mean birth weight of 2635 ± 740 g. Of all these patients, six (8.0%) cases developed placenta percreta, seven (9.0%) were transferred to the intensive care unit (ICU), 14 (18.0%) women needed blood transfusion and eight (11.0%) underwent hysterectomy. The results of our series show a strong correlation of placenta previa to a history of previous C-sections and a predominance of male fetuses. Early recognition and proper monitoring could minimize the possibility of a poor outcome. PMID:29876227

Association of Placenta Previa with a History of Previous Cesarian Deliveries and Indications for a Possible Role of a Genetic Component.

PubMed

M, Matalliotakis; A, Velegrakis; Gn, Goulielmos; E, Niraki; Ae, Patelarou; I, Matalliotakis

2017-12-01

A prior Cesaria section (C-section) is an important risk factor that leads to endometrial damage and abnormal implantation of the placenta. Our retrospective study aims to correlate the frequency of placenta previa to previous C-sections, to determine the effect of male gender in this condition and to evaluate further the maternal outcome. Seventy-six cases with placenta previa were selected out of 5200 live births. Diagnosis was confirmed by ultrasound and in the operating theater. In the 76 women examined, we found 50 cases with a history of a previous C-section (66.0%) and 49 male offspring (65.0%) ( p <0.001), with a mean birth weight of 2635 ± 740 g. Of all these patients, six (8.0%) cases developed placenta percreta, seven (9.0%) were transferred to the intensive care unit (ICU), 14 (18.0%) women needed blood transfusion and eight (11.0%) underwent hysterectomy. The results of our series show a strong correlation of placenta previa to a history of previous C-sections and a predominance of male fetuses. Early recognition and proper monitoring could minimize the possibility of a poor outcome.

Scoring model to predict massive post-partum bleeding in pregnancies with placenta previa: A retrospective cohort study.

PubMed

Lee, Ji Yeon; Ahn, Eun Hee; Kang, Sukho; Moon, Myung Jin; Jung, Sang Hee; Chang, Sung Woon; Cho, Hee Young

2018-01-01

We aimed to identify factors associated with massive post-partum bleeding in pregnancies with placenta previa and to establish a scoring model to predict post-partum severe bleeding. A retrospective cohort study was performed in 506 healthy singleton pregnancies with placenta previa from 2006 to 2016. Cases with intraoperative blood loss (≥2000 mL), packed red blood cells transfusion (≥4), uterine artery embolization, or hysterectomy were defined as massive bleeding. After performing multivariable analysis, using the adjusted odds ratios (aOR), we formulated a scoring model. Seventy-three women experienced massive post-partum bleeding (14.4%). After multivariable analysis, seven variables were associated with massive bleeding: maternal old age (≥35 years; aOR 1.79, 95% confidence interval [CI] 1.00-3.20, P = 0.049), antepartum bleeding (aOR 4.76, 95%CI 2.01-11.02, P < 0.001), non-cephalic presentation (aOR 3.41, 95%CI 1.40-8.30, P = 0.007), complete placenta previa (aOR 1.93, 95%CI 1.05-3.54, P = 0.034), anterior placenta (aOR 2.74, 95%CI 1.54-4.89, P = 0.001), multiple lacunae (≥4; aOR 2.77, 95%CI 1.54-4.99, P = 0.001), and uteroplacental hypervascularity (aOR 4.51, 95%CI 2.30-8.83, P < 0.001). We formulated a scoring model including maternal old age (<35: 0, ≥35: 1), antepartum bleeding (no: 0, yes: 2), fetal non-cephalic presentation (no: 0, yes: 2), placenta previa type (incomplete: 0, complete: 1), placenta location (posterior: 0, anterior: 1), uteroplacental hypervascularity (no: 0, yes: 2), and multiple lacunae (no: 0, yes: 1) to predict post-partum massive bleeding. According to our scoring model, a score of 5/10 had a sensitivity of 81% and a specificity of 77% for predicting massive post-partum bleeding. The area under the receiver-operator curve was 0.856 (P < 0.001). The negative predictive value was 95.9%. Our scoring model might provide useful information for prediction of massive post-partum bleeding in pregnancies with placenta previa. © 2017 Japan Society of Obstetrics and Gynecology.

Morphologic Basis for Developing Diverticular Disease, Diverticulitis, and Diverticular Bleeding.

PubMed

Wedel, Thilo; Barrenschee, Martina; Lange, Christina; Cossais, François; Böttner, Martina

2015-04-01

Diverticula of the colon are pseudodiverticula defined by multiple outpouchings of the mucosal and submucosal layers penetrating through weak spots of the muscle coat along intramural blood vessels. A complete prolapse consists of a diverticular opening, a narrowed neck, and a thinned diverticular dome underneath the serosal covering. The susceptibility of diverticula to inflammation is explained by local ischemia, translocation of pathogens due to retained stool, stercoral trauma by fecaliths, and microperforations. Local inflammation may lead to phlegmonous diverticulitis, paracolic/mesocolic abscess, bowel perforation, peritonitis, fistula formation, and stenotic strictures. Diverticular bleeding is due to an asymmetric rupture of distended vasa recta at the diverticular dome and not primarily linked to inflammation. Structural and functional changes of the bowel wall in diverticular disease comprise: i) Altered amount, composition, and metabolism of connective tissue; ii) Enteric myopathy with muscular thickening, deranged architecture, and altered myofilament composition; iii) Enteric neuropathy with hypoganglionosis, neurotransmitter imbalance, deficiency of neurotrophic factors and nerve fiber remodeling; and iv) Disturbed intestinal motility both in vivo (increased intraluminal pressure, motility index, high-amplitude propagated contractions) and in vitro (altered spontaneous and pharmacologically triggered contractility). Besides established etiologic factors, recent studies suggest that novel pathophysiologic concepts should be considered in the pathogenesis of diverticular disease.

Morphologic Basis for Developing Diverticular Disease, Diverticulitis, and Diverticular Bleeding

PubMed Central

Wedel, Thilo; Barrenschee, Martina; Lange, Christina; Cossais, François; Böttner, Martina

2015-01-01

Diverticula of the colon are pseudodiverticula defined by multiple outpouchings of the mucosal and submucosal layers penetrating through weak spots of the muscle coat along intramural blood vessels. A complete prolapse consists of a diverticular opening, a narrowed neck, and a thinned diverticular dome underneath the serosal covering. The susceptibility of diverticula to inflammation is explained by local ischemia, translocation of pathogens due to retained stool, stercoral trauma by fecaliths, and microperforations. Local inflammation may lead to phlegmonous diverticulitis, paracolic/mesocolic abscess, bowel perforation, peritonitis, fistula formation, and stenotic strictures. Diverticular bleeding is due to an asymmetric rupture of distended vasa recta at the diverticular dome and not primarily linked to inflammation. Structural and functional changes of the bowel wall in diverticular disease comprise: i) Altered amount, composition, and metabolism of connective tissue; ii) Enteric myopathy with muscular thickening, deranged architecture, and altered myofilament composition; iii) Enteric neuropathy with hypoganglionosis, neurotransmitter imbalance, deficiency of neurotrophic factors and nerve fiber remodeling; and iv) Disturbed intestinal motility both in vivo (increased intraluminal pressure, motility index, high-amplitude propagated contractions) and in vitro (altered spontaneous and pharmacologically triggered contractility). Besides established etiologic factors, recent studies suggest that novel pathophysiologic concepts should be considered in the pathogenesis of diverticular disease. PMID:26989376

Germ Cell Development in the Scleractinian Coral Euphyllia ancora (Cnidaria, Anthozoa)

PubMed Central

Shikina, Shinya; Chen, Chieh-Jhen; Liou, Jhe-Yu; Shao, Zi-Fan; Chung, Yi-Jou; Lee, Yan-Horn; Chang, Ching-Fong

2012-01-01

Sexual reproduction of scleractinian coral is among the most important means of establishing coral populations. However, thus far, little is known about the mechanisms underlying coral gametogenesis. To better understand coral germ cell development, we performed a histological analysis of gametogenesis in Euphyllia ancora and characterized the coral homolog of the Drosophila germline marker gene vasa. The histological analysis revealed that E. ancora gametogenesis occurs in the mesenterial mesoglea between the mesenterial filaments and the retractor muscle bands. The development of germ cells takes approximately one year in females and half a year in males. Staining of tissue sections with an antibody against E. ancora Vasa (Eavas) revealed anti-Eavas immunoreactivity in the oogonia, early oocyte, and developing oocyte, but only faint or undetectable reactivity in developing oocytes that were >150 µm in diameters. In males, Eavas could be detected in the spermatogonia and primary spermatocytes but was only faintly detectable in the secondary spermatocytes, spermatids, and sperms. Furthermore, a reverse transcription-polymerase chain reaction analysis and Western blotting analysis of unfertilized mature eggs proved the presence of Eavas transcripts and proteins, suggesting that Eavas may be a maternal factor. Vasa may represent a germ cell marker for corals, and would allow us to distinguish germ cells from somatic cells in coral bodies that have no distinct organs. PMID:22848529

Germ cell development in the scleractinian coral Euphyllia ancora (Cnidaria, Anthozoa).

PubMed

Shikina, Shinya; Chen, Chieh-Jhen; Liou, Jhe-Yu; Shao, Zi-Fan; Chung, Yi-Jou; Lee, Yan-Horn; Chang, Ching-Fong

2012-01-01

Sexual reproduction of scleractinian coral is among the most important means of establishing coral populations. However, thus far, little is known about the mechanisms underlying coral gametogenesis. To better understand coral germ cell development, we performed a histological analysis of gametogenesis in Euphyllia ancora and characterized the coral homolog of the Drosophila germline marker gene vasa. The histological analysis revealed that E. ancora gametogenesis occurs in the mesenterial mesoglea between the mesenterial filaments and the retractor muscle bands. The development of germ cells takes approximately one year in females and half a year in males. Staining of tissue sections with an antibody against E. ancora Vasa (Eavas) revealed anti-Eavas immunoreactivity in the oogonia, early oocyte, and developing oocyte, but only faint or undetectable reactivity in developing oocytes that were >150 µm in diameters. In males, Eavas could be detected in the spermatogonia and primary spermatocytes but was only faintly detectable in the secondary spermatocytes, spermatids, and sperms. Furthermore, a reverse transcription-polymerase chain reaction analysis and Western blotting analysis of unfertilized mature eggs proved the presence of Eavas transcripts and proteins, suggesting that Eavas may be a maternal factor. Vasa may represent a germ cell marker for corals, and would allow us to distinguish germ cells from somatic cells in coral bodies that have no distinct organs.

Effect of Primary Elective Cesarean Delivery on Placenta Accreta: A Case-Control Study.

PubMed

Shi, Xiao-Ming; Wang, Yan; Zhang, Yan; Wei, Yuan; Chen, Lian; Zhao, Yang-Yu

2018-03-20

Cesarean section (CS) is an independent risk factor for placenta accreta. Some researchers think that the timing of primary cesarean delivery is associated with placenta accreta in subsequent pregnancies. The aim of this study was to investigate the risk of placenta accreta following primary CS without labor, also called primary elective CS, in a pregnancy complicated with placenta previa. A retrospective, single-center, case-control study was conducted at Peking University Third Hospital. Relevant clinical data of singleton pregnancies between January 2010 and September 2017 were recorded. The case group included women with placenta accreta who had placenta previa and one previous CS. Control group included women with one previous CS that was complicated with placenta previa. Maternal age, body mass index, gestational age, fetal birth weight, gravity, parity, induced abortion, the rate of women received assisted reproductive technology, other uterine surgery, and primary elective CS were analyzed between the two groups. The rate of primary elective CS (90.1% vs. 69.9%, P < 0.001) was higher, and maternal age was younger (32.7 ± 4.7 years vs. 34.6 ± 4.0 years, P < 0.001) in case group, compared with control group. Case group also had higher gravity and induced abortions compared with the control group (both P < 0.05). Primary CS without labor was associated with significantly increased risk of placenta accreta in a subsequent pregnancy complicated with placenta previa (odds ratio: 3.32; 95% confidential interval: 1.68-6.58). Women with a primary elective CS without labor have a higher chance of developing an accreta in a subsequent pregnancy that is complicated with placenta previa.

Effect of Primary Elective Cesarean Delivery on Placenta Accreta: A Case-Control Study

PubMed Central

Shi, Xiao-Ming; Wang, Yan; Zhang, Yan; Wei, Yuan; Chen, Lian; Zhao, Yang-Yu

2018-01-01

Background: Cesarean section (CS) is an independent risk factor for placenta accreta. Some researchers think that the timing of primary cesarean delivery is associated with placenta accreta in subsequent pregnancies. The aim of this study was to investigate the risk of placenta accreta following primary CS without labor, also called primary elective CS, in a pregnancy complicated with placenta previa. Methods: A retrospective, single-center, case-control study was conducted at Peking University Third Hospital. Relevant clinical data of singleton pregnancies between January 2010 and September 2017 were recorded. The case group included women with placenta accreta who had placenta previa and one previous CS. Control group included women with one previous CS that was complicated with placenta previa. Maternal age, body mass index, gestational age, fetal birth weight, gravity, parity, induced abortion, the rate of women received assisted reproductive technology, other uterine surgery, and primary elective CS were analyzed between the two groups. Results: The rate of primary elective CS (90.1% vs. 69.9%, P < 0.001) was higher, and maternal age was younger (32.7 ± 4.7 years vs. 34.6 ± 4.0 years, P < 0.001) in case group, compared with control group. Case group also had higher gravity and induced abortions compared with the control group (both P < 0.05). Primary CS without labor was associated with significantly increased risk of placenta accreta in a subsequent pregnancy complicated with placenta previa (odds ratio: 3.32; 95% confidential interval: 1.68–6.58). Conclusion: Women with a primary elective CS without labor have a higher chance of developing an accreta in a subsequent pregnancy that is complicated with placenta previa. PMID:29521289

Intraoperative aortic balloon occlusion in patients with placenta previa and/or placenta accreta: a retrospective study.

PubMed

Luo, Fangyuan; Xie, Lan; Xie, Ping; Liu, Siwei; Zhu, Yue

2017-04-01

To introduce the primary experience of using aortic balloon catheters during cesarean section for placenta previa and/or placenta accreta. From January 2013 to May 2015, 43 patients who were preoperatively diagnosed with major placenta previa and/or placenta accreta and who underwent prophylactic aortic catheterization before caesarean section (CS) were included in the study. We analyzed the clinical data of the study population. Surgery- and catheterization-related complications were also reported. Major placenta previa or placenta accreta was surgically confirmed in 42 patients, 28 of whom had both conditions. The mean patient age was 32.3 ± 5.5 years, whereas the median gestational age at delivery was 260 (range, 153-280) days. Twenty-nine (67.4%) patients had previously undergone CS, and 13 (30%) patients had undergone emergency surgery for antenatal hemorrhage. The median estimated blood loss during surgery was 500 (range, 100-3,000) mL, and the median duration of occlusion was 20 (range, 5-32) minutes. Hysterectomy was performed in five (11.6%) patients and uterine artery embolization in two (4.6%) patients. Two patients with placenta percreta experienced surgery-related complications, and two patients required hospital readmission. No major catheterization-related complications were observed. Forty-two live births were recorded, and the Apgar score of the infants at 5 minutes was > 7. Intraoperative aortic balloon occlusion is a relatively safe method for treating placenta previa and/or placenta accreta during scheduled and emergency CS and might be helpful to prevent hysterectomy and embolization in women wishing to preserve fertility. Copyright © 2017. Published by Elsevier B.V.

Soluble FLT-1 rules placental destiny.

PubMed

Yamashita, Michiko; Kumasawa, Keiichi; Nakamura, Hitomi; Kimura, Tadashi

2018-02-19

Placenta previa is an abnormality in which the placenta covers the internal uterine os, and it can cause serious morbidity and mortality in both mother and fetus due to catastrophic hemorrhage. Some pregnant women recover from placenta previa due to a phenomenon called "migration." However, the mechanism of "migration" of the placenta has not been elucidated. Human placentas were collected from patients with placenta previa and those with no abnormal placentation (control). A microarray analysis was performed to detect the genes up- or down-regulated only in the caudal part in the previa group. Specific mRNA expression was evaluated using real-time quantitative reverse transcription PCR (qRT-PCR). Unilateral uterine artery ablation of 8.5 dpc mice was performed to reproduce the reduction of placental blood supply, and weights of the placentas and fetuses were evaluated in 18.5 dpc. Specific mRNA expression was also evaluated in mice placentas. According to the result of the microarray analysis, we focused on soluble fms-like tyrosine kinase-1 (sFLT-1) and hypoxia-inducible factor-1 (HIF-1) alpha. The sFLT-1 expression level is locally high in the caudal part of the human placenta in patients with placenta previa. In mice experiments, the weights of the placentas and fetuses were significantly smaller in the ablation side than those in the control side, and the sFlt-1 expression level was significantly higher in the ablation side than in the control side. Our study suggests that "migration" of the placenta is derived from placental degeneration at the caudal part of the placenta, and sFlt-1 plays a role in this placental degeneration. Copyright © 2018 Elsevier Inc. All rights reserved.

Fishery Induces Sperm Depletion and Reduction in Male Reproductive Potential for Crab Species under Male-Biased Harvest Strategy

PubMed Central

Pardo, Luis Miguel; Rosas, Yenifer; Fuentes, Juan Pablo; Riveros, Marcela Paz; Chaparro, Oscar Roberto

2015-01-01

Sperm depletion in males can occur when polygynous species are intensively exploited under a male-biased management strategy. In fisheries involving crabs species, the effects of this type of management on the reproductive potential is far from being understood. This study tests whether male-biased management of the principal Chilean crab fishery is able to affect the potential capacity of Metacarcinus edwardsii males to transfer sperm to females. Five localities in southern Chile, recording contrasting crab fishery landing, were selected to assess the potential of sperm depletion triggered by fishery. Seasonally, male crabs from each locality were obtained. Dry weight and histological condition of vasa deferentia and the Vaso-Somatic Index (VSI) were determined in order to use them as proxies for sperm depletion and male reproductive condition. A manipulative experiment was performed in the laboratory to estimate vasa deferentia weight and VSI from just-mated males in order to obtain a reference point for the potential effects of the fishery on sperm reserves. Sperm storage capacity is significantly affected by fisheries; during the mating season vasa deferentia from localities with low fishery intensity were heavier than those from high intensity fisheries, and these differences were even more evident in large males. Histological section showed that this disparity in vasa deferentia weight was explained principally by differences in the quantity of spermatophores rather than other seminal material. VSI was always higher in males from localities with low fishery intensity. Males from localities with high fishery intensity showed little capacity to recover sperm reserves and the VSI of these males remained below the values of the just-mated males. Detriment in the capacity of males to transfer sperm is the first step to sperm limitation in an exploited population, thus detection of sperm depletion can be an alert to introduce changes in the current management of crabs. PMID:25768728

Reversibility of Vasalgel™ male contraceptive in a rabbit model.

PubMed

Waller, Donald; Bolick, David; Lissner, Elaine; Premanandan, Christopher; Gamerman, Gary

2017-01-01

Development of a non-hormonal long-acting reversible contraceptive for men could have a significant impact on reducing unintended pregnancies. Vasalgel™ is a high molecular weight polymer consisting of styrene-alt-maleic acid (SMA) dissolved in dimethyl sulfoxide being developed as a reversible male contraceptive device. It forms a hydrogel when implanted into the vasa deferentia, which prevents the passage of sperm. Previous studies in the rabbit have proven its efficacy, durability and rapid onset. This study evaluates the capacity to restore sperm concentrations in ejaculates after a reversal procedure. Sodium bicarbonate was injected into the vasa deferentia after fourteen months of azoospermia following the injection of two device variations (Vasalgel 100 and Vasalgel 80). Semen samples were then collected for six months and sperm characteristics were compared to baseline levels. Samples of vasa deferentia were obtained for histological examination. Spermatozoa were present in all subject ejaculates after the reversal procedure. Sperm concentration and sperm motility were similar to baseline levels after reversal, while sperm forward progression was significantly lower and normal acrosomes were not observed. Forward progression percentages increased linearly during six months of semen collection, however, normal acrosomes were not observed at the conclusion of the study. Histologically, several vasa deferentia were clear of the device and contained an intact epithelial lining. A smaller proportion of tissues contained residual test material. A secondary intraluminal inflammatory response was seen occasionally in the tissues containing residual material. There was no difference between the two device variations for studied parameters. Vasalgel's prevention of sperm transport for 14 months was reversed through an intravasal injection of sodium bicarbonate. Post-reversal sperm concentrations and motility returned to baseline levels during the six-month follow up. Residual material in the vas lumen or compromised epididymal and vas deferens function may be resulting in reduced forward progression and loss of acrosomes during transit through the vas. Reduced forward progression and the lack of normal acrosomes strongly suggest impaired sperm function.

[Twin pregnancy with complete mole and coexisting fetus after in vitro fertilization and embryo transfer complicated with placenta previa accreta. A case report].

PubMed

Guzmán González, Eduardo; Gaviño Gaviño, Fernando; Valero Origel, Alberto; Deschamps Díaz, Horacio; Ramírez Fernández, María Antonieta; Miranda Lamadrid, Mario

2009-03-01

The double twin pregnancy with complete hydatidiform mole and coexistent fetus is a rare event and perinatal treatment complex. Presents a significant case of this unusual partnership and describes their evolution. Patient of 33 years, secondary infertility factor-peritoneal tube and pregnancy achieved by in vitro fertilization and embryo transfer. An ultrasound early pregnancy reported twice, a sack was a complete mole, another bag was a fetus and placenta previa unchanged total. The case is carefully monitored and uterine inhibitors were administered at different stages of gestation. It settled the case by caesarean section at 37 weeks and obstetric hysterectomy for placenta previa percreta molar involution of the placenta and newborn health. The evolution of the mother and the child was appropriate.

Placenta accreta and balloon catheterization: the experience of a single center and an update of latest evidence of literature.

PubMed

Gulino, Ferdinando Antonio; Guardo, F Di; Zambrotta, E; Di Gregorio, L M; Miranda, Andrea; Capriglione, Stella; Palumbo, M A

2018-05-18

We studied the efficacy of using pre-cesarean delivery (CD) temporary occlusion of internal iliac arteries with balloon catheters in case of placenta previa-accreta in terms of maternal and neonatal outcomes and to test accuracy of ultrasound (US) and magnetic resonance imaging (MRI) for prenatal diagnosis. From March 2014 to January 2018, women with an US and/or MRI diagnosis of placenta previa-accreta and a planned delivery were enrolled and divided into two groups: balloon catheterization group (women treated with preoperative catheters and CD) and control group (women candidates to elective CD). 37 patients were enrolled: 16 in balloon catheterization group and 21 in control group. Significant differences were detected in estimated blood loss. Prophylactic balloon catheterization could reduce intraoperative red blood cell transfusion. The incidence of hysterectomy was lower in balloon group. No statistical difference was found for neonatal outcomes. Both US and MRI have showed to be useful and complementary to diagnose placenta previa-accreta. Temporal, perioperative, and prophylactic positioning of balloon vascular catheters is an effective method for managing severe hemorrhage caused by placenta previa-accreta as it reduced intraoperative blood loss, lessened perioperative hemostatic measures and intraoperative red cell transfusions, and reduced hysterectomies.

Prophylactic temporary abdominal aorta balloon occlusion in women with placenta previa accretism during late gestation.

PubMed

Qiu, Zhongyuan; Hu, Jifen; Wu, Jianbo; Chen, Lihong

2017-11-01

To evaluate the clinical efficacy of prophylactic temporary balloon occlusion of the abdominal aorta in patients with placenta previa accretism during cesarean section. Twenty-three consecutive patients, prenatally confirmed with placenta previa accretism were retrospectively analyzed in our center from August 2012 to October 2014. All 23 subjects underwent cesarean section with prophylactic balloon occlusion of the abdominal aorta. All of the 23 subjects experienced singleton pregnancies leading to the birth of live infants. Of these subjects, the following problems were diagnosed: placenta accrete (n = 10), placenta increte (n = 10), and placenta precrete (n = 3). Mean intraoperative hemorrhage was 1170.0 mL. Fifteen patients received red blood cell transfusion with a mean transfusion volume of 2.3 units. The incidence of hysterectomy was 21.74% (5/23) with blood loss ranging from 2000 to 5000 mL (mean 3360.0 mL). One complication encountered in this retrospective study was lower extremity arterial thrombosis. Eighteen patients were followed-up by telephone to 14 months following discharge, all babies were noted to be healthy. Prophylactic abdominal aorta balloon occlusion (ABO) was relatively safe in the treatment of patients with placenta previa accretism. This approach could represent a key aspect in a multidisciplinary algorithm in reducing hemorrhage in abnormal placentation.

Direct puncture embolization of the internal iliac artery during cesarean delivery for pernicious placenta previa coexisting with placenta accreta.

PubMed

Chen, Zhenyu; Li, Ju; Shen, Jian; Jin, Jiaxi; Zhang, Wei; Zhong, Wan

2016-12-01

To evaluate direct puncture embolization of the internal iliac artery with hemostatic gelatin sponge particles to treat pernicious placenta previa coexisting with placenta accreta during cesarean delivery. A retrospective study was conducted of data from women with pernicious placenta previa and placenta accreta who underwent direct puncture embolization of the internal iliac artery during cesarean delivery at a center in China between September 1, 2013, and February 28, 2015. Information regarding surgical procedures, operative data, and outcomes during hospitalization were obtained from medical records. The procedure was successful in all 16 cases included. Mean operative time was 78 minutes (range 65-90) and mean estimated blood loss was 1550 mL (range 1000-2500). Complications such as fever, buttock pain, or acute limb ischemia were not observed. The procedure was performed after partial cystectomy for two patients with bladder invasion. Postoperative Doppler imaging indicated uterine recovery and normalized uterine blood flow in all patients. Direct puncture embolization of the internal iliac artery during cesarean delivery was a safe, effective, simple, and rapid method to control hemorrhage among women with pernicious placenta previa and placenta accreta. Copyright © 2016 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Placenta previa and it's relation with maternal age, gravidity and cesarean section.

PubMed

Hossain, G A; Islam, S M; Mahmood, S; Chakraborty, R K; Akhter, N; Sultana, S

2004-07-01

The placenta provides the essential connection between the mother and the developing fetus. Placental position were routinely mentioned in an ultrasound report starting from early second trimester to the end of third trimester when asked for pregnancy evaluation. The aim of this study was to see the prevalence of lower segment placenta (placenta previa) and its relations with previous cesarean section delivery, parity and maternal age. The study conducted in Centre for Nuclear Medicine and Ultrasound (CNMU) Mymensingh in a period from January 2001 to December 2002. About 2536 pregnant women (those included in this study) underwent ultrasound examination during pregnancy at third trimester. The prevalence of lower segment placenta was 1.34%. The highest prevalence of placenta previa (2.58%) was seen in 3rd and higher gravida group. Also the highest prevalence were seen 30 yr. and above age group in compare to below 30 yr. age group. No increased prevalence of placenta previa were seen in previous cesarean section (C / S) delivery group (0.65%) in compare to normal delivery group (1.97%). From our study it was seen that development of lower segment placenta has relation with increased number of gravidity and maternal age but no increased prevalence were seen in subjects with previously done cesarean section

Periodontal disease activity measured by the benzoyl-DL-arginine-naphthylamide test is associated with preterm births.

PubMed

Chan, Hui-Chen; Wu, Chen-Tsai; Welch, Kathleen B; Loesche, Walter J

2010-07-01

Infection is a risk factor for preterm birth. This study was conducted in the field and addressed the link between periodontal pathogens measured with the benzoyl-DL-arginine-naphthylamide (BANA) test and preterm birth. This prospective study was performed in Changhua, Taiwan. Periodontal examinations included the plaque index, papillary bleeding scores, and measurement of the BANA enzyme in plaque samples at the second and third trimesters. Independent variables included maternal demographic characteristics, previous pregnancy histories, risk factors, plaque and gingivitis scores, and current pregnancy outcomes. There were 19 (7%) preterm deliveries among the 268 subjects. A history of a previous preterm birth and low birth weight, frequency of prenatal visits, preterm uterine contractions, antepartum hemorrhages, placenta previae, and preterm premature rupture of membranes were significantly related to preterm birth (P = 0.035, 0.027, <0.001, 0.025, 0.006, 0.014, and <0.001, respectively). Maternal weight gain was higher with a normal term delivery (P = 0.003). Multivariable logistic regression analyses showed that the number of BANA-infected sites in the third trimester (odds ratio [OR]: 5.89; 95% confidence interval [CI]: 1.5 to 31.6), maternal weight gain (OR: 0.78; 95% CI: 0.65 to 0.91), antepartum hemorrhages (OR: 10.0; 95% CI: 2.2 to 46.9), and preterm premature rupture of membranes (OR: 12.6; 95% CI: 3.97 to 42.71) had significant influences on preterm-birth outcomes. BANA-positive plaque in the third trimester was associated with preterm births after controlling for other risk factors. The BANA test can be used to screen pregnant women at chairside and/or bedside to apply suitable intervention tactics.

Vasectomy: subclinical pathologic changes.

PubMed

Taxy, J B; Marshall, F F; Erlichman, R J

1981-12-01

The nature of the local histopathologic changes secondary to vasectomy is described in tissue excised at vasovasostomy in 37 secondarily infertile patients. Segments of surgically removed vasa were also studied in four patients with primary infertility who underwent scrotal explorations and subsequent vasoepididymostomy. Except for infertility, all patients were asymptomatic. Three, often concurrent, inflammatory or proliferative changes were found in 50 of 76 segments of vasa deferentia. These included suture granuloma, sperm granuloma, and vasitis nodosa, the last being a ductular proliferation originating from the central vas lumen and extending into the perivasal soft tissues. Vasitis nodosa occurred in 66% of the patients, and although it was often found with a sperm granuloma, it did occur by itself and is a lesion which should be recognized.

How might flukes and tapeworms maintain genome integrity without a canonical piRNA pathway?

PubMed Central

Skinner, Danielle E.; Rinaldi, Gabriel; Koziol, Uriel; Brehm, Klaus; Brindley, Paul J.

2014-01-01

Surveillance by RNA interference is central to controlling the mobilization of transposable elements (TEs). In stem cells, Piwi argonaute (Ago) proteins and associated proteins repress mobilization of TEs to maintain genome integrity. This defense mechanism targeting TEs is termed the Piwi-interacting RNA (Piwi-piRNA) pathway. In this Opinion, we draw attention to the situation that the genomes of cestodes and trematodes have lost the piwi and vasa genes that are hallmark characters of the germline multipotency program. This absence of Piwi-like Agos and Vasa helicases prompts the question: how does the germline of these flatworms withstand mobilization of TEs? Here we present an interpretation of mechanisms likely to defend the germline integrity of parasitic flatworms. PMID:24485046

A novel organelle, the piNG-body, in the nuage of Drosophila male germ cells is associated with piRNA-mediated gene silencing.

PubMed

Kibanov, Mikhail V; Egorova, Ksenia S; Ryazansky, Sergei S; Sokolova, Olesia A; Kotov, Alexei A; Olenkina, Oxana M; Stolyarenko, Anastasia D; Gvozdev, Vladimir A; Olenina, Ludmila V

2011-09-01

Proteins of the PIWI subfamily Aub and AGO3 associated with the germline-specific perinuclear granules (nuage) are involved in the silencing of retrotransposons and other selfish repetitive elements in the Drosophila genome. PIWI proteins and their 25- to 30-nt PIWI-interacting RNA (piRNAs) are considered as key participants of the piRNA pathway. Using immunostaining, we found a large, nuage-associated organelle in the testes, the piNG-body (piRNA nuage giant body), which was significantly more massive than an ordinary nuage granule. This body contains known ovarian nuage proteins, including Vasa, Aub, AGO3, Tud, Spn-E, Bel, Squ, and Cuff, as well as AGO1, the key component of the microRNA pathway. piNG-bodies emerge at the primary spermatocyte stage of spermatogenesis during the period of active transcription. Aub, Vasa, and Tud are located at the periphery of the piNG-body, whereas AGO3 is found in its core. Mutational analysis revealed that Vasa, Aub, and AGO3 were crucial for both the maintenance of the piNG-body structure and the silencing of selfish Stellate repeats. The piNG-body destruction caused by csul mutations that abolish specific posttranslational symmetrical arginine methylation of PIWI proteins is accompanied by strong derepression of Stellate genes known to be silenced via the piRNA pathway.

Architecture of vasa recta in the renal inner medulla of the desert rodent Dipodomys merriami: potential impact on the urine concentrating mechanism.

PubMed

Issaian, Tadeh; Urity, Vinoo B; Dantzler, William H; Pannabecker, Thomas L

2012-10-01

We hypothesize that the inner medulla of the kangaroo rat Dipodomys merriami, a desert rodent that concentrates its urine to over 6,000 mosmol/kg H(2)O, provides unique examples of architectural features necessary for production of highly concentrated urine. To investigate this architecture, inner medullary vascular segments in the outer inner medulla were assessed with immunofluorescence and digital reconstructions from tissue sections. Descending vasa recta (DVR) expressing the urea transporter UT-B and the water channel aquaporin 1 lie at the periphery of groups of collecting ducts (CDs) that coalesce in their descent through the inner medulla. Ascending vasa recta (AVR) lie inside and outside groups of CDs. DVR peel away from vascular bundles at a uniform rate as they descend the inner medulla, and feed into networks of AVR that are associated with organized clusters of CDs. These AVR form interstitial nodal spaces, with each space composed of a single CD, two AVR, and one or more ascending thin limbs or prebend segments, an architecture that may lead to solute compartmentation and fluid fluxes essential to the urine concentrating mechanism. Although we have identified several apparent differences, the tubulovascular architecture of the kangaroo rat inner medulla is remarkably similar to that of the Munich Wistar rat at the level of our analyses. More detailed studies are required for identifying interspecies functional differences.

Transecting versus avoiding incision of the anterior placenta previa during cesarean delivery.

PubMed

Verspyck, Eric; Douysset, Xavier; Roman, Horace; Marret, Stephane; Marpeau, Loïc

2015-01-01

To compare maternal outcomes after transection and after avoiding incision of the anterior placenta previa during cesarean delivery. In a retrospective study, records were reviewed for women who had anterior placenta previa and delivered by cesarean after 24 weeks of pregnancy at a tertiary center in Rouen, France. During period A (January 2000 to December 2006), the protocol was to systematically transect the placenta when it was unavoidable. During period B (January 2007 to December 2010), the technique was to avoid incision by circumventing the placenta and passing a hand around its margin. Logistic regression was used to identify independent risk factors associated with maternal transfusion of packed red blood cells. Eighty-four women were included (period A: n=43; period B: n=41). During period B, there was a reduction in frequency of intraoperative hemorrhage (>1000 mL) (P=0.02), intraoperative hemoglobin loss (P=0.005), and frequency of blood transfusion (P=0.02) as compared with period A. In multivariable analysis, period B was associated with a reduced risk of maternal transfusion (odds ratio 0.27; 95% confidence interval 0.09-0.82; P=0.02). Avoiding incision of the anterior placenta previa was found to reduce frequency of maternal blood transfusion during or after cesarean delivery. Copyright © 2014 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Intrauterine Inflated Foley's Catheter Balloon in the Management of Abnormally Invasive Placenta Previa: A Case-Control Study.

PubMed

Thabet, Mahmoud; Abdelhafez, Mohamed Sayed; Fyala, Emad Ahmed

2018-06-01

To describe the use of intrauterine inflated Foley's catheter balloon for control of postpartum hemorrhage (PPH) during cesarean section (CS) in cases of abnormally invasive placenta previa aiming to preserve the uterus. Retrospective case-control study of the data of women who underwent elective CS on abnormally adherent placenta previa was carried out. Women in whom inflated Foley's catheter balloon was used for control of PPH during CS ( n  = 40) were compared with a control group of women who underwent elective CS by the same technique but without use of intrauterine catheter balloon ( n  = 38). Use of intrauterine inflated Foley's catheter balloon significantly reduced the estimated amount of blood loss ( P  = 0.008), amounts of crystalloids, colloids and packed red blood cells transfusion ( P  = 0.025, 0.017 and 0.022, respectively), and the need for bilateral internal iliac artery (IIA) ligation ( P  = 0.016). No significant difference was observed between both groups regarding the use of massive transfusion protocol, performing cesarean hysterectomy, relaparotomy, and admission to the intensive care unit. Application of an intrauterine inflated Foley's catheter balloon during CS in cases of morbidly adherent placenta previa helps to control PPH with preservation of the uterus and decreases the need for the invasive IIA ligation.

Prophylactic temporary abdominal aorta balloon occlusion in women with placenta previa accretism during late gestation

PubMed Central

Qiu, Zhongyuan; Hu, Jifen; Wu, Jianbo; Chen, Lihong

2017-01-01

Abstract Background: To evaluate the clinical efficacy of prophylactic temporary balloon occlusion of the abdominal aorta in patients with placenta previa accretism during cesarean section. Methods: Twenty-three consecutive patients, prenatally confirmed with placenta previa accretism were retrospectively analyzed in our center from August 2012 to October 2014. All 23 subjects underwent cesarean section with prophylactic balloon occlusion of the abdominal aorta. Results: All of the 23 subjects experienced singleton pregnancies leading to the birth of live infants. Of these subjects, the following problems were diagnosed: placenta accrete (n = 10), placenta increte (n = 10), and placenta precrete (n = 3). Mean intraoperative hemorrhage was 1170.0 mL. Fifteen patients received red blood cell transfusion with a mean transfusion volume of 2.3 units. The incidence of hysterectomy was 21.74% (5/23) with blood loss ranging from 2000 to 5000 mL (mean 3360.0 mL). One complication encountered in this retrospective study was lower extremity arterial thrombosis. Eighteen patients were followed-up by telephone to 14 months following discharge, all babies were noted to be healthy. Conclusion: Prophylactic abdominal aorta balloon occlusion (ABO) was relatively safe in the treatment of patients with placenta previa accretism. This approach could represent a key aspect in a multidisciplinary algorithm in reducing hemorrhage in abnormal placentation. PMID:29145299

How might flukes and tapeworms maintain genome integrity without a canonical piRNA pathway?

PubMed

Skinner, Danielle E; Rinaldi, Gabriel; Koziol, Uriel; Brehm, Klaus; Brindley, Paul J

2014-03-01

Surveillance by RNA interference is central to controlling the mobilization of transposable elements (TEs). In stem cells, Piwi argonaute (Ago) proteins and associated proteins repress mobilization of TEs to maintain genome integrity. This defense mechanism targeting TEs is termed the Piwi-interacting RNA (piRNA) pathway. In this opinion article, we draw attention to the situation that the genomes of cestodes and trematodes have lost the piwi and vasa genes that are hallmark characters of the germline multipotency program. This absence of Piwi-like Agos and Vasa helicases prompts the question: how does the germline of these flatworms withstand mobilization of TEs? Here, we present an interpretation of mechanisms likely to defend the germline integrity of parasitic flatworms. Copyright © 2014 Elsevier Ltd. All rights reserved.

Diagnosis of Placenta Accreta by Uterine Artery Doppler Velocimetry in Patients With Placenta Previa.

PubMed

Cho, Hee Young; Hwang, Han Sung; Jung, Inkyung; Park, Yong Won; Kwon, Ja-Young; Kim, Young Han

2015-09-01

To evaluate the potential value of uterine artery Doppler velocimetry in diagnosing placenta accreta. Clinical records of all deliveries between April 1991 and March 2013 were retrospectively analyzed. Cases of intrauterine growth restriction, pregnancy-induced hypertension, multiple pregnancies, fetal anomalies, chromosomal abnormalities, and maternal medical illnesses such as cardiovascular disease, renal disease, and diabetes mellitus were excluded. A total of 11,210 cases were evaluated, including 403 cases of placenta previa without accreta (placenta previa) and 39 cases of placenta previa with accreta (placenta accreta). All patients underwent uterine artery Doppler velocimetry to measure the mean resistive index and pulsatility index (PI) in the third trimester. The analysis included participant characteristics such as age, parity, abortion history, previous cesarean delivery, gestational age at delivery, neonatal sex, and birth weight. The mean uterine artery PI was significantly lower in the placenta accreta group compared to previa alone (0.51 versus 0.57; P = .002). The odds ratios for placenta accreta were 2.4 for 2 or more previous abortions (P = .011) and 5.3 and 7.0 for 1 and 2 or more previous cesarean deliveries (P = .001 and .005). With an increase in the mean PI by 0.01, the odds ratio for placenta accreta decreased by 0.94 (P < .001). The area under the receive operating characteristic curve was 0.72 for previous cesarean delivery alone, increasing to 0.77 with the combination of the mean PI and previous cesarean delivery (P = .047). This study suggests that the mean PI measured by uterine artery Doppler velocimetry is reduced in patients with placenta accreta compared to those without accreta. The diagnostic accuracy of placenta accreta can be potentially improved if uterine artery Doppler values and the history of cesarean delivery are combined. © 2015 by the American Institute of Ultrasound in Medicine.

Serial Change in Cervical Length for the Prediction of Emergency Cesarean Section in Placenta Previa

PubMed Central

Shin, Jae Eun; Shin, Jong Chul; Lee, Young; Kim, Sa Jin

2016-01-01

Purpose To evaluate whether serial change in cervical length (CL) over time can be a predictor for emergency cesarean section (CS) in patients with placenta previa. Methods This was a retrospective cohort study of patients with placenta previa between January 2010 and November 2014. All women were offered serial measurement of CL by transvaginal ultrasound at 19 to 23 weeks (CL1), 24 to 28 weeks (CL2), 29 to 31 weeks (CL3), and 32 to 34 weeks (CL4). We compared clinical characteristics, serial change in CL, and outcomes between the emergency CS group (case group) and elective CS group (control group). The predictive value of change in CL for emergency CS was evaluated. Results A total of 93 women were evaluated; 31 had emergency CS due to massive vaginal bleeding. CL tended to decrease with advancing gestational age in each group. Until 29–31 weeks, CL showed no significant differences between the two groups, but after that, CL in the emergency CS group decreased abruptly, even though CL in the elective CS group continued to gradually decrease. On multivariate analysis to determine risk factors, only admissions for bleeding (odds ratio, 34.710; 95% CI, 5.239–229.973) and change in CL (odds ratio, 3.522; 95% CI, 1.210–10.253) were significantly associated with emergency CS. Analysis of the receiver operating characteristic curve showed that change in CL could be the predictor of emergency CS (area under the curve 0.734, p < 0.001), with optimal cutoff for predicting emergency cesarean delivery of 6.0 mm. Conclusions Previous admission for vaginal bleeding and change in CL are independent predictors of emergency CS in placenta previa. Women with change in CL more than 6 mm between the second and third trimester are at high risk of emergency CS in placenta previa. Single measurements of short CL at the second or third trimester do not seem to predict emergency CS. PMID:26863133

Serial Change in Cervical Length for the Prediction of Emergency Cesarean Section in Placenta Previa.

PubMed

Shin, Jae Eun; Shin, Jong Chul; Lee, Young; Kim, Sa Jin

2016-01-01

To evaluate whether serial change in cervical length (CL) over time can be a predictor for emergency cesarean section (CS) in patients with placenta previa. This was a retrospective cohort study of patients with placenta previa between January 2010 and November 2014. All women were offered serial measurement of CL by transvaginal ultrasound at 19 to 23 weeks (CL1), 24 to 28 weeks (CL2), 29 to 31 weeks (CL3), and 32 to 34 weeks (CL4). We compared clinical characteristics, serial change in CL, and outcomes between the emergency CS group (case group) and elective CS group (control group). The predictive value of change in CL for emergency CS was evaluated. A total of 93 women were evaluated; 31 had emergency CS due to massive vaginal bleeding. CL tended to decrease with advancing gestational age in each group. Until 29-31 weeks, CL showed no significant differences between the two groups, but after that, CL in the emergency CS group decreased abruptly, even though CL in the elective CS group continued to gradually decrease. On multivariate analysis to determine risk factors, only admissions for bleeding (odds ratio, 34.710; 95% CI, 5.239-229.973) and change in CL (odds ratio, 3.522; 95% CI, 1.210-10.253) were significantly associated with emergency CS. Analysis of the receiver operating characteristic curve showed that change in CL could be the predictor of emergency CS (area under the curve 0.734, p < 0.001), with optimal cutoff for predicting emergency cesarean delivery of 6.0 mm. Previous admission for vaginal bleeding and change in CL are independent predictors of emergency CS in placenta previa. Women with change in CL more than 6 mm between the second and third trimester are at high risk of emergency CS in placenta previa. Single measurements of short CL at the second or third trimester do not seem to predict emergency CS.

Asymptomatic "placental prolapse" with cervical funneling in a patient with complete placenta previa.

PubMed

Adekola, Henry; Lam-Rachlin, Jennifer; Bronshtein, Elena; Abramowicz, Jacques S

2015-02-01

We describe the transvaginal sonographic findings in a patient with complete placenta previa and increased risk of preterm birth owing to a prior history of mid-trimester pregnancy loss in whom we observed a short cervix and prolapse of the placenta and fetal membranes into the endocervical canal. We believe that this could lead to antepartum hemorrhage and mandate close observation when diagnosed. We introduced the term "placental prolapse" to describe our finding. © 2015 Wiley Periodicals, Inc.

Optimal timing of antenatal corticosteroids in women with bleeding placenta previa or low-lying placenta.

PubMed

Alsayegh, Eman; Barrett, Jon; Melamed, Nir

2018-01-11

Administrating a single course of antenatal corticosteroids to women at risk of preterm birth between 24 and 34 weeks of gestation has been shown to decrease neonatal morbidity and mortality. There is evidence that the optimal timing for the administration of antenatal corticosteroids is within 1-7 days before birth as the effect of antenatal corticosteroids has been shown to decline 7 days after administration. Therefore, given that antenatal corticosteroids are the single most effective intervention in cases of preterm birth, efforts should be made to optimize the timing of administration of antenatal corticosteroids. To test the hypothesis that the timing of antenatal corticosteroids in women with vaginal bleeding due to placenta previa or low-lying placenta can be optimized by identifying women at low risk of imminent delivery. This was a retrospective cohort study of all women admitted to a tertiary referral center at 24-34 weeks' gestation with vaginal bleeding due to placenta previa or low-lying placenta between 2003 and 2014. Multivariable logistic regression analysis was used to identify factors that are independently associated with delivery within 14 days from admission. A total of 202 women who met the inclusion criteria were admitted with vaginal bleeding in the presence of placenta previa or low-lying placenta during the study period, of whom 31 (15.3%) and 44 (21.8%) gave birth within 7 and 14 days from admission, respectively. The following factors were independently associated with delivery within 14 days from admission: complete placenta previa (odds (OR) 3.57, 95%CI 1.57-9.03), severe bleeding at presentation (OR 17.14, 95%CI 2.92-100.70), uterine contractions at presentation (OR 6.02, 95%CI 1.91-19.00), and cervical length <25 mm at presentation (OR 6.33, 95%CI 1.37-29.11). A predictive test based on the presence of ≥1 of these risk factors was associated with a sensitivity of 90.9% and a negative predictive value of 94.6% for delivery within 14 days of presentation. In women presenting with vaginal bleeding due to placenta previa or low-lying placenta, it seems possible to identify a subgroup of women in whom the likelihood of delivery within 14 days is low. This information may allow for selective (rather than routine) administration of antenatal corticosteroids in this scenario, and may thereby contribute to the optimization of the timing of administration of antenatal corticosteroids.

Sonoembryological evaluations of the development of placenta previa and velamentous cord insertion.

PubMed

Hasegawa, Junichi

2015-01-01

Longitudinal and cross-sectional investigations using ultrasound examinations during pregnancy can be used to clarify the mechanisms and pathophysiology of abnormal fetal and placental development. Such sonoembryological assessments are useful as a method for clarifying the etiology of disease. In the present review, we describe current knowledge based on our experience with applying sonoembryological methods to determine the developmental mechanisms of placenta previa and velamentous cord insertion. © 2014 The Author. Journal of Obstetrics and Gynaecology Research © 2014 Japan Society of Obstetrics and Gynecology.

[Application of temporary balloon occlusion of the abdominal aorta in the treatment of complete placenta previa complicated with placenta accreta].

PubMed

Cui, S H; Zhi, Y X; Zhang, K; Zhang, L D; Shen, L N; Gao, Y N

2016-09-25

Objective: To investigate the value of temporary balloon occlusion of the abdominal aorta in the treatment of complete placenta previa with placenta accreta. Methods: From January 2015 to February 2016, 24 cases of complete placenta previa with placenta accreta were treated with temporary balloon occlusion of the abdominal aorta(the study group)before cesarean, and 24 cases of complete placenta previa with placenta accreta did not receive balloon occlusion(the control group). The operation time, intraoperative blood loss, intraoperative blood transfusion volume, the perioperative hemoglobin level, the hysterectomy rate and the related complications were compared retrospectively.Also, the hospitalization time, the blood coagulation parameters after operation, including activated partial thromboplastin time(APTT), fibrinogen(FIB), D-Dimer and reperfusion injury parameters including creatine phosphokinase(CK), creatine phosphokinase isoenzyme(CK-MB), lactate dehydrogenase(LDH)and serum creatinine were compared between the 2 groups. Results: The blood loss[750 ml(400- 2 000 ml)vs 2 000 ml(1 500- 2 375 ml); Z =-3.214, P =0.001]and blood transfusion volume[200 ml(0-800 ml)vs 800 ml(0-1 200 ml); Z =- 2.173, P =0.030]in the study group were lower than in the control group. The hemoglobin difference between before and after operation in the study group was lower than the control group[(12.8±13.4)g/L vs(22.9±20.1)g/L; t =-2.041, P =0.047]. In the study group, there were still bleeding in 13 cases after releasing the balloon, 5 of them received uterine artery embolization, 5 cases received uterine artery ligation, and 3 cases received uterine packing. One case had venous thrombosis in the right lower limb. Two cases(8%,2/24)in the control group had hysterectomy, while none in the study group, there was no statistical significance( P = 0.489). Conclusions: Temporary balloon occlusion of the abdominal aorta can effectively reduce blood loss and blood transfusion in the treatment of complete placenta previa with placenta accreta, but there is still the risk of continuing bleeding after releasing the balloon. Other methods of hemostasis might be needed.

Pre-cesarean prophylactic balloon placement in the internal iliac artery to prevent postpartum hemorrhage among women with pernicious placenta previa.

PubMed

Meng-Jun, Dai; Guang-Xin, Jin; Jian-Hua, Lin; Yu, Zhang; Yun-Yan, Chen; Xue-Bin, Zhang

2018-06-07

To evaluate pre-cesarean prophylactic balloon placement (PBP) in the internal iliac artery among women with pernicious placenta previa. The present retrospective study included women with pernicious placenta previa who underwent cesarean delivery at Shanghai Renji Hospital, Shanghai, China, between March 1, 2011, and June 30, 2017. Data were compared between patients who did and did not undergo PBP. Among 42 patients included, 20 underwent PBP and 22 did not. Mean±SD estimated blood loss was 2900.00±2352.21 mL in the PBP group, and 4549.77±2366.67 mL in the non-PBP group (P=0.025). The amount of transfused red blood cells was 8.40±7.14 U and 13.00±7.93 U (P=0.018), respectively. No patients in the PBP group developed postoperative disseminated intravascular coagulopathy, compared with 3 (14%) in the non-PBP group (P=0.087). In the PBP and non-PBP groups, the hospital stay duration was 7.40±3.07 and 8.68±2.58 days (P=0.029), and there were 1 and 7 patients who had obstetric hysterectomies (P=0.027), respectively. Two patients experienced PBP-related adverse events, including thrombosis and re-bleeding. There were no deaths. Pre-cesarean PBP in the internal iliac artery was a safe and effective treatment that could reduce the incidence of both postpartum hemorrhage and hysterectomy among women with pernicious placenta previa. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Hypoperfusion of the Adventitial Vasa Vasorum Develops an Abdominal Aortic Aneurysm

PubMed Central

Sasaki, Takeshi; Sano, Masaki; Yamamoto, Naoto; Saito, Takaaki; Inuzuka, Kazunori; Hayasaka, Takahiro; Goto-Inoue, Naoko; Sugiura, Yuki; Sato, Kohji; Kugo, Hirona; Moriyama, Tatsuya; Konno, Hiroyuki; Setou, Mitsutoshi; Unno, Naoki

2015-01-01

The aortic wall is perfused by the adventitial vasa vasorum (VV). Tissue hypoxia has previously been observed as a manifestation of enlarged abdominal aortic aneurysms (AAAs). We sought to determine whether hypoperfusion of the adventitial VV could develop AAAs. We created a novel animal model of adventitial VV hypoperfusion with a combination of a polyurethane catheter insertion and a suture ligation of the infrarenal abdominal aorta in rats. VV hypoperfusion caused tissue hypoxia and developed infrarenal AAA, which had similar morphological and pathological characteristics to human AAA. In human AAA tissue, the adventitial VV were stenotic in both small AAAs (30–49 mm in diameter) and in large AAAs (> 50 mm in diameter), with the sac tissue in these AAAs being ischemic and hypoxic. These results indicate that hypoperfusion of adventitial VV has critical effects on the development of infrarenal AAA. PMID:26308526

Magnetic resonance imaging - A troubleshooter in obstetric emergencies: A pictorial review

PubMed Central

Gupta, Rohini; Bajaj, Sunil Kumar; Kumar, Nishith; Chandra, Ranjan; Misra, Ritu Nair; Malik, Amita; Thukral, Brij Bhushan

2016-01-01

The application of magnetic resonance imaging (MRI) in pregnancy faced initial skepticism of physicians because of fetal safety concerns. The perceived fetal risk has been found to be unwarranted and of late, the modality has attained acceptability. Its role in diagnosing fetal anomalies is well recognized and following its safety certification in pregnancy, it is finding increasing utilization during pregnancy and puerperium. However, the use of MRI in maternal emergency obstetric conditions is relatively limited as it is still evolving. In early gestation, ectopic implantation is one of the major life-threatening conditions that are frequently encountered. Although ultrasound (USG) is the accepted mainstay modality, the diagnostic predicament persists in many cases. MRI has a role where USG is indeterminate, particularly in the extratubal ectopic pregnancy. Later in gestation, MRI can be a useful adjunct in placental disorders like previa, abruption, and adhesion. It is a good problem-solving tool in adnexal masses such as ovarian torsion and degenerated fibroid, which have a higher incidence during pregnancy. Catastrophic conditions like uterine rupture can also be preoperatively and timely diagnosed. MRI has a definite role to play in postpartum and post-abortion life-threatening conditions, e.g., retained products of conception, and gestational trophoblastic disease, especially when USG is inconclusive or inadequate. PMID:27081223

[Evaluation of the women's knowledge about Fetal Tobacco Syndrome].

PubMed

Wolska, Agata

2004-01-01

Smoking is still a common habit in Poland. Nowadays, it is the way of coping with stress, it is used to become calm or more alert. It is also widely accepted by people from various backgrounds. Unfortunately, the number of young women--tobacco addicts is increasing. Smoking before and during pregnancy has bad effects on women and their children as well. First discoveries of negative influence of smoking observed lesser birth weight of the babies whose mothers were smokers, compared with the babies whose mothers were non-smokers (Simpson 1957). He proved in his research that the more the mother smokes the lesser the birth weight of her baby is, and it doesn't depend on the woman's age, weight, height or gynecological past. Pregnant women who smoke more often suffer from such consequences as: bleeding during pregnancy, placenta abruption, placenta previa, premature rupture of membranes. The fetus death rate after the twentieth week of pregnancy is much higher among smoking women than non-smoking ones. Lower fertility and conception difficulties are also consequences of smoking. Therefore, the education of girls and women in the period before they plan having children is very important. The mother and child's health depends exclusively on the knowledge, awareness and attitudes of future parents.

Center variation in the delivery of indicated late preterm births

PubMed Central

Aliaga, Sofia; Zhang, Jun; Long, D. Leann; Herring, Amy H.; Laughon, Matthew; Boggess, Kim; Reddy, Uma M.; Grantz, Katherine Laughon

2016-01-01

Objective Evidence for optimal timing of delivery for some pregnancy complications at late preterm gestation is limited. The purpose of this study was to identify center variation of indicated late preterm births. Study design Analysis of singleton late preterm and term births from a large U.S. retrospective obstetrical cohort. Births associated with spontaneous preterm labor, major congenital anomalies, chorioamnionitis, and emergency cesarean were excluded. We used modified Poisson fixed effects logistic regression with interaction terms to assess center variation of indicated late preterm births associated with four medical/obstetric comorbidities after adjusting for socio-demographics, co-morbidities, and hospital/provider characteristics. Results We identified 150,055 births from 16 hospitals; 9218 were indicated late preterm births. We found wide variation of indicated late preterm births across hospitals. The extent of center variation was greater for births associated with preterm premature rupture of membranes (RR across sites: 0.45 – 3.05), hypertensive disorders of pregnancy (RR across sites: 0.36 – 1.27), and placenta previa/abruption (RR across sites: 0.48 – 1.82). We found less center variation for births associated with diabetes (RR across sites: 0.65 – 1.39). Conclusion Practice variation in the management of indicated late preterm deliveries might be a source of preventable late preterm birth. PMID:27120474

Obstetric outcomes of patients with abortus imminens in the first trimester.

PubMed

Evrenos, Ayşe Nur; Cakir Gungor, Ayse Nur; Gulerman, Cavidan; Cosar, Emine

2014-03-01

We aimed to find out the effect of abortus imminens (AI) on obstetric outcomes of pregnancies which continued beyond the 24th week of gestation. In this prospective study, 309 patients with AI were divided into high-risk group (with a risk factor for spontaneous abortus) (n = 92) and low-risk group (without a risk factor) (n = 217). The control group (n = 308) was chosen randomly. In AI group, preterm delivery, preterm premature rupture of membranes (PPROM), cesarean section (C/S) delivery, postpartum uterine atony and need of a neonatal intensive care unit (NICU) rates were significantly higher than control group. Gestational diabetes mellitus, PPROM, still birth, low APGAR scores were seen more frequently in the high-risk patients than in the control group. Furthermore in the high-risk group, preterm delivery, malpresentation, C/S delivery and need of NICU were increased much more than in the low-risk group. Gestational hypertension/preeclampsia, oligo/polyhydramniosis, intrauterine growth retardation, placenta previa, abruption of placenta, chorioamnionitis, congenital abnormalities, delivery induction, cephalopelvic disproportion, fetal distress and manual removal of placenta were not different among the groups. Patients with AI history, especially with high-risk factors can have adverse obstetric and neonatal results. So their antenatal follow-up has to be done cautiously for the early signs and symptoms of these complications.

Obstetrician perceptions of the causes of high cesarean delivery rates in Turkey.

PubMed

Küçük, Mert

2017-07-01

To assess obstetricians' perceptions surrounding cesarean delivery rates in Turkey. The present cross-sectional descriptive study was performed between May 1 and June 30, 2016. Practicing obstetricians with contact details known by the researchers and those attending a conference in Turkey were asked to complete a self-administered questionnaire that collected demographic data and information on participants' opinions, beliefs, knowledge, attitudes, and practices related to cesarean delivery. There were 100 obstetricians who responded to the survey. Awareness of high cesarean delivery rates was reported by 96 (96%) participants and 95 (95%) respondents said they were supportive of efforts to reduce it. There were 60 (60%), 83 (83%), and 100 (100%) participants aware of associations between high cesarean delivery rates and increased maternal and infant mortality; increased risk of uterine rupture; and increased risk of placenta previa, placenta accreta, and emergency cesarean hysterectomy, respectively. The most commonly reported reason for high cesarean delivery rates was high compensation costs during medical litigation legal proceedings, reported by all 100 (100%) participants. Participants were generally aware of the risks associated with high cesarean delivery rates. The results suggest that the greatest concern among obstetricians who perform cesarean deliveries was malpractice litigation. © 2017 International Federation of Gynecology and Obstetrics.

Obstetrical complications of endometriosis, particularly deep endometriosis.

PubMed

Leone Roberti Maggiore, Umberto; Inversetti, Annalisa; Schimberni, Matteo; Viganò, Paola; Giorgione, Veronica; Candiani, Massimo

2017-12-01

Over the past few years, a new topic in the field of endometriosis has emerged: the potential impact of the disease on pregnancy outcomes. This review aims to summarize in detail the available evidence on the relationship between endometriosis, particularly deep endometriosis (DE), and obstetrical outcomes. Acute complications of DE, such as spontaneous hemoperitoneum, bowel perforation, and uterine rupture, may occur during pregnancy. Although these events represent life-threatening conditions, they are rare and unpredictable. Therefore, the current literature does not support any kind of prophylactic surgery before pregnancy to prevent such complications. Results on the impact of DE on obstetrical outcomes are debatable and characterized by several limitations, including small sample size, lack of adjustment for confounders, lack of adequate control subjects, and other methodologic flaws. For these reasons, it is not possible to draw conclusions on this topic. The strongest evidence shows that DE is associated with higher rates of placenta previa; for other obstetrical outcomes, such as miscarriage, intrauterine growth restriction, preterm birth and hypertensive disorders, results are controversial. Although it is unlikely that surgery of DE may modify the impact of the disease on the course of pregnancy, no study has yet investigated this issue. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Tissue Regeneration and Biomineralization in Sea Urchins: Role of Notch Signaling and Presence of Stem Cell Markers

PubMed Central

Reinardy, Helena C.; Emerson, Chloe E.; Manley, Jason M.; Bodnar, Andrea G.

2015-01-01

Echinoderms represent a phylum with exceptional regenerative capabilities that can reconstruct both external appendages and internal organs. Mechanistic understanding of the cellular pathways involved in regeneration in these animals has been hampered by the limited genomic tools and limited ability to manipulate regenerative processes. We present a functional assay to investigate mechanisms of tissue regeneration and biomineralization by measuring the regrowth of amputated tube feet (sensory and motor appendages) and spines in the sea urchin, Lytechinus variegatus. The ability to manipulate regeneration was demonstrated by concentration-dependent inhibition of regrowth of spines and tube feet by treatment with the mitotic inhibitor, vincristine. Treatment with the gamma-secretase inhibitor DAPT resulted in a concentration-dependent inhibition of regrowth, indicating that both tube feet and spine regeneration require functional Notch signaling. Stem cell markers (Piwi and Vasa) were expressed in tube feet and spine tissue, and Vasa-positive cells were localized throughout the epidermis of tube feet by immunohistochemistry, suggesting the existence of multipotent progenitor cells in these highly regenerative appendages. The presence of Vasa protein in other somatic tissues (e.g. esophagus, radial nerve, and a sub-population of coelomocytes) suggests that multipotent cells are present throughout adult sea urchins and may contribute to normal homeostasis in addition to regeneration. Mechanistic insight into the cellular pathways governing the tremendous regenerative capacity of echinoderms may reveal processes that can be modulated for regenerative therapies, shed light on the evolution of regeneration, and enable the ability to predict how these processes will respond to changing environmental conditions. PMID:26267358

Comparison of alprazolam versus captopril in high blood pressure: a randomized controlled trial.

PubMed

Yilmaz, Serkan; Pekdemir, Murat; Tural, Umit; Uygun, Mecit

2011-08-01

OBJECTIVE. Anxiety is an important cause of acute blood pressure (BP) elevation. However, the role of anxiolysis in this situation is still controversial. In this study, the relationship of anxiety with BP and the effect of anxiolytic treatment on BP were investigated. METHODS. Emergency department (ED) patients with an initial systolic BP (SBP) ≥ 160 mmHg or diastolic BP (DBP) ≥ 100 mmHg but no end organ damage were approached for inclusion in the study. In those consenting to participate, anxiety levels were measured using the State-Trait Anxiety Index (STAI) and Visual Analog Scale for Anxiety (VAS-A). Patients were randomly assigned to receive oral alprazolam 0.5 mg or captopril 25 mg. BP and anxiety levels were measured at baseline and at 1 and 2 h after administration of the study medication. RESULTS. Of 133 patients meeting inclusion criteria, 53 patients agreed to participate. Of these, 27 patients (50.9%) received captopril and 26 patients (49.1%) received alprazolam. The majority of the patients had a high-level trait (96.2%, n = 51) and state anxiety (81.1%, n = 43). The mean SBP and VAS-A values of both patient groups dropped significantly over the 2 h, with no significant difference between the two groups. A significant association between SBP and VAS-A scores was found (F((2,50)) = 6.27, p = 0.004). A significant association exists between the level of BP and anxiety in hypertensive ED patients. Alprazolam is as effective as captopril in lowering BP in ED patients with an initial SBP > 160 mmHg.

Molecular cloning and characterization of oocyte-specific Pat1a in Rana rugosa frogs.

PubMed

Nakamura, Yoriko; Iwasaki, Takehiro; Umei, Yosuke; Saotome, Kazuhiro; Nakajima, Yukiko; Kitahara, Shoichi; Uno, Yoshinobu; Matsuda, Yoichi; Oike, Akira; Kodama, Maho; Nakamura, Masahisa

2015-10-01

The Pat1 gene is expressed in the immature oocytes of Xenopus, and is reportedly involved in regulating the translation of maternal mRNAs required for oocyte-maturation. However, it is still unknown when Pat1a first appears in the differentiating ovary of amphibians. To address this issue, we isolated the full-length Pat1a cDNA from the frog Rana rugosa and examined its expression in the differentiating ovary of this frog. Among eight different tissues examined, the Pat1a mRNA was detectable in only the ovary. When frozen sections from the ovaries of tadpoles at various stages of development were immunostained for Vasa-a germ cell-specific protein-and Pat1a, Vasa-immunopositive signals were observed in all of the germ cells, whereas Pat1a signals were confined to the growing oocytes (50-200 μm in diameter), and absent from small germ cells (<50 μm in diameter). Forty days after testosterone injection into tadpoles to induce female-to-male sex-reversal, Pat1a-immunoreactive oocytes had disappeared completely from the sex-reversed gonad, but Vasa-positive small germ cells persisted. Thus, Pat1a would be a good marker for identifying the sexual status of the sex-reversing gonad in amphibians. In addition, fluorescence in situ hybridization analysis showed Pat1a to have an autosomal locus, suggesting that Pat1a transcription is probably regulated by a tissue-specific transcription factor in R. rugosa. © 2015 Wiley Periodicals, Inc.

Regulation of Injury-Induced Ovarian Regeneration by Activation of Oogonial Stem Cells.

PubMed

Erler, Piril; Sweeney, Alexandra; Monaghan, James R

2017-01-01

Some animals have the ability to generate large numbers of oocytes throughout life. This raises the question whether persistent adult germline stem cell populations drive continuous oogenesis and whether they are capable of mounting a regenerative response after injury. Here we demonstrate the presence of adult oogonial stem cells (OSCs) in the adult axolotl salamander ovary and show that ovarian injury induces OSC activation and functional regeneration of the ovaries to reproductive capability. Cells that have morphological similarities to germ cells were identified in the developing and adult ovaries via histological analysis. Genes involved in germ cell maintenance including Vasa, Oct4, Sox2, Nanog, Bmp15, Piwil1, Piwil2, Dazl, and Lhx8 were expressed in the presumptive OSCs. Colocalization of Vasa protein with H3 mitotic marker showed that both oogonial and spermatogonial adult stem cells were mitotically active. Providing evidence of stemness and viability of adult OSCs, enhanced green fluorescent protein (EGFP) adult OSCs grafted into white juvenile host gonads gave rise to EGFP OSCs, and oocytes. Last, the axolotl ovaries completely regenerated after partial ovariectomy injury. During regeneration, OSC activation resulted in rapid differentiation into new oocytes, which was demonstrated by Vasa + /BrdU + coexpression. Furthermore, follicle cell proliferation promoted follicle maturation during ovarian regeneration. Overall, these results show that adult oogenesis occurs via proliferation of endogenous OSCs in a tetrapod and mediates ovarian regeneration. This study lays the foundations to elucidate mechanisms of ovarian regeneration that will assist regenerative medicine in treating premature ovarian failure and reduced fertility. Stem Cells 2017;35:236-247. © 2016 AlphaMed Press.

A case study on displacement analysis of Vasa warship

NASA Astrophysics Data System (ADS)

Eshagh, Mehdi; Johansson, Filippa; Karlsson, Lenita; Horemuz, Milan

2018-04-01

Monitoring deformation of man-made structures is very important to prevent them from a risk of collapse and save lives. Such a process is also used for monitoring change in historical objects, which are deforming continuously with time. An example of this is the Vasa warship, which was under water for about 300 years. The ship was raised from the bottom of the sea and is kept in the Vasa museum in Stockholm. A geodetic network with points on the museum building and the ship's body has been established and measured for 12 years for monitoring the ship's deformation. The coordinate time series of each point on the ship and their uncertainties have been estimated epoch-wisely. In this paper, our goal is to statistically analyse the ship's hull movements. By fitting a quadratic polynomial to the coordinate time series of each point of the hull, its acceleration and velocity are estimated. In addition, their significance is tested by comparing them with their respective estimated errors after the fitting. Our numerical investigations show that the backside of the ship, having highest elevation and slope, has moved vertically faster than the other places by a velocity and an acceleration of about 2 mm/year and 0.1 mm/year2, respectively and this part of the ship is the weakest with a higher risk of collapse. The central parts of the ship are more stable as the ship hull is almost vertical and closer to the floor. Generally, the hull is moving towards its port and downwards

Comparing effects between music intervention and aromatherapy on anxiety of patients undergoing mechanical ventilation in the intensive care unit: a randomized controlled trial.

PubMed

Lee, Chiu-Hsiang; Lai, Chiung-Ling; Sung, Yi-Hui; Lai, Mei Yu; Lin, Chung-Ying; Lin, Long-Yau

2017-07-01

Using patient-reported outcomes and physiological indicators to test the effects of music intervention and aromatherapy on reducing anxiety for intensive care unit (ICU) patients undergoing mechanical ventilation. Patients with ICU admission duration >24 h were randomly assigned to a Music intervention group (n = 41), Aromatherapy group (n = 47), or Control group (rest only; n = 44). Each patient in the Music group listened to music; each patient in the Aromatherapy group received lavender essential oil massage on his/her back for 5 min; each patient in the Control group wore noise-canceling headphones. Anxiety was measured using the Chinese version of the Stage-Trait Anxiety Inventory (C-STAI) and the Visual Analogue Scale for Anxiety (VAS-A) at baseline, post-test, and 30-min follow-up. Heart rate, breathing rate, and blood pressure were measured every 10 min from baseline to the 30-min follow-up. The Music group had significantly better post-test VAS-A and C-STAI scores, and had lower heart rate and blood pressure than the Control group. The Aromatherapy group had significantly better VAS-A score and lower heart rate than the Control group. The 30-min follow-up showed that both Music and Aromatherapy groups had lower heart rate and blood pressure than the Control group. Music and aromatherapy interventions were both effective for ICU patients. The effects of music intervention were greater than that of aromatherapy; both interventions maintained the effects for at least 30 min.

Perinatal Outcomes Associated With Isolated Velamentous Cord Insertion in Singleton and Twin Pregnancies.

PubMed

Sinkin, Joshua A; Craig, Wendy Y; Jones, Michael; Pinette, Michael G; Wax, Joseph R

2018-02-01

To evaluate perinatal outcomes in singleton and twin pregnancies with pathologically confirmed velamentous cord insertion without vasa previa. This retrospective case-control study included all nonanomalous singleton and twin pregnancies with pathologically confirmed velamentous cord insertion delivered in a single institution between January 1, 2005, and July 1, 2015, and having an ultrasound examination by maternal-fetal medicine. For each case, the next 2 consecutive deliveries matched for gestational age at delivery ± 1 week and, in twins, amnionicity and chorionicity served as controls. Primary outcomes included surgical delivery for a nonreassuring intrapartum fetal heart rate tracing, umbilical arterial cord pH of less than 7.2, 5-minute Apgar score of less than 7, birth weight below the 10th percentile, neonatal intensive care unit admission, fetal or neonatal death, and cord avulsion necessitating manual placental extraction. Outcomes were available for 53 singletons with 103 matched controls and 33 twin pregnancies with 65 matched controls. In singletons, velamentous cord insertion was associated with cord pH of less than 7.2 (odds ratio [OR] 3.5; 95% confidence interval [CI], 1.1-11.2; P = .039), 5-minute Apgar score of less than 7 (OR, 5.3; 95% CI, 0.99-28.1; P = .045), and cord avulsion requiring manual placental extraction (7.5% versus 0%; P = .012). Associations were suggested with increased surgical delivery for a nonreassuring intrapartum fetal heart rate tracing (OR, 2.4; 95% CI, 0.9-6.9; P = .14), birth weight below the 10th percentile (OR, 2.1; 95% CI, 0.8-5.9; P = .21), and fetal or neonatal death (3.8% versus 0%; P = .11). Velamentous cord insertions were also associated with placental abruption in singletons (7.5% versus 0%; P = .013). Among twins, velamentous cord insertion was associated with fetal or neonatal death (9.1% versus 0%; P = .036). Isolated confirmed velamentous cord insertion is associated with adverse perinatal outcomes in singleton and twin gestations. © 2017 by the American Institute of Ultrasound in Medicine.

"Endoview" project of intrapartum endoscopy.

PubMed

Petrikovsky, Boris M; Ravens, Steven

2002-01-01

The change in obstetrical practices over the last decade in favor of trials of labor in patients with uterine scars has resulted in increased incidences of uterine ruptures. Although neither repeat cesarean delivery nor a trial of labor is risk free, evidence from a large multicenter study shows vaginal birth after the cesarean (VBAC) is associated with shorter hospital stays, fewer postpartum blood transfusions, and a decreased incidence of postpartum maternal fever. The uterine rupture remains the most serious complication associated with VBAC. Factors associated with uterine rupture include excessive exposure to oxytocin, dysfunctional labor, and a history of more than 1 cesarean delivery.2 Because uterine rupture may be a life-threatening event, intrapartum surveillance and the ability to perform an emergency surgery are both necessary when trial of labor is allowed. Until now, no early symptoms pathognomonic to uterine rupture had been described. We share our experiences with the novel approach to the problem - an intrapartum endoscopy. Endoscopic examination was accomplished by using the intraoperational fiberscope (Olympus and Endoview system (Costa Mesa, CA, USA). A gas-sterilized 25-cm long fiberscope is introduced into the amniotic cavity through the cervical canal after rupture of the membranes. The distance between the fiberscope and the object varies from 3 to 50 mm. The fiberscope has a separate channel for the fluid infusion (normal saline) throughout the procedure; the surgeon looks through the eyepiece directly and exhibits control over the flexible scope. The duration of endoscopy is less than 15 minutes. The inserting of the endoscopic device is very similar to that of insertion of an intrauterine pressure catheter. The IRB Committees of both participating institutions approved the study protocol. Twenty-eight patients with an unknown or poorly documented site of the uterine scar were included in the study. An ultrasound examination had been performed on all patients prior to endoscopy to assess fetal wellbeing and placental location. The ages of the patients ranged from 21 to 38 years. Eighteen women had 1 previous cesarean delivery, and 10 had 2. The performance of intrapartum endoscopy did not interfere with fetal monitoring; 21 fetuses were monitored externally, 7 internally. Indications for previous cesarean deliveries were as follows: fetal distress in 11 cases, failure to progress in labor in 8, placenta previa in 2, and unknown in 7. Twenty-one patients delivered vaginally; 7 had had repeat cesarean deliveries. All neonates were born in satisfactory condition. The Apgar scores at 1 minute varied from 7 to 9 and at 5 minutes from 8 to 10. The integrity of the uterine wall was assessed by manual postpartum uterine exploration in each case of vaginal delivery and by visualization and palpation of the scar site in each abdominal delivery. The lower uterine segment and contractile portion of the anterior uterine wall were visualized successfully in all patients. In 25 patients, the presumed scar site looked totally indistinguishable from the rest of the lower uterine segment and anterior uterine wall. Two scars were identified as vertical in 2 patients who were delivered by a repeat abdominal operation. A vertical scar appears as a groove running in a cephalad-caudad direction from the lower uterine segment into the contractile portion of the anterior uterine wall. The usefulness of the intrapartum endoscopy is best demonstrated by the following case reports (2 of 28 study cases).

[The Application of Internal Iliac Artery Balloon Occlusion in Pernicious Placenta Previa].

PubMed

Qi, Xiao-Rong; Liu, Xing-Hui; You, Yong; Wang, Xiao-Dong; Zhou, Rong; Xing, Ai-Yun; Zhang, Li; Ning, Gang; Zhao, Fu-Min; Li, Kai-Ming

2016-07-01

To evaluate the clinical application value of internal iliac artery balloon occlusion in pernicious placenta previa. We retrospectively reviewed the medical records of the patients of pernicious placenta previa in a single center from Jan, 2010 to Jan, 2015. The patients were divided into two groups, internal iliac artery balloon occlusion group and the control group without endovascular intervention. Blood loss in operation, volume of transfused blood products, caesarean hysterectomy, operating time, hospital days after operation and postoperative morbidity were compared between the two groups. The balloon occlusion group had significantly less blood loss, the volume of transfused blood products, caesarean hysterectomy, hospital day after operation than the control group had. There was no statistical difference in operating time, intensive care units (ICU), hypotension, infection, hypoxemia, bladder injury, bowel obstruction, neonatal asphyxia between the two groups. The balloon occlusion group had significantly higher rate in coagulopathy, hypoalbuminemia, electrolyte imbalance. Among the patients whose uterus were preserved, the blood loss was not significantly difference between the two groups. Among the patients with the complication of placenta accreta, caesarean hysterectomy was less in balloon group, and blood loss between the two groups was not significantly different. Among the patients without placenta accrete, the blood loss was less in balloon group, and caesarean hysterectomy between the two groups was not significantly different. The risk of hysterectomy in balloon group was related to placenta accreta, uterine arteries engorgement, placental invasive serosa, taking placenta by hand, placental invasive bladder, barrel-shaped thickening of lower uterine segment, unable to remove placenta. Internal iliac artery balloon occlusion is an effective treatment for pernicious placenta previa.

Aortic balloon occlusion for controlling intraoperative hemorrhage in patients with placenta previa increta/percreta.

PubMed

Wang, Ying-Lan; Su, Fang-Ming; Zhang, Hai-Ying; Wang, Fang; Zhe, Rui-Lian; Shen, Xin-Ying

2017-11-01

To investigate whether abdominal aortic balloon occlusion (ABO) effectively reduces intraoperative hemorrhage in patents with placenta previa increta/increta. Forty-three women were diagnosed as placenta previa increta/percreta by ultrasound and MRI. These patients' assessments were taken by their chief physician, and they were under necessity of previous cesarean section as confirmed by the committee of experts during consultation. There was no significant difference in disease risk rating between them in whole process. Although our department provided a more appropriate method, 10 of 43 patients chose intraoperative aortic balloon occlusion (IABO). Other 33 patients who refused that suggestion were considered as control group. Fully informed consents were obtained from all patients in this study group. The intraoperative blood loss, blood transfusion, rate of hysterectomy and complications of mothers and fetus of IABO group and control group were analyzed. The median intraoperative blood loss was 1000 ml in the IABO group compared with 2000 ml in the control group (p < 0.05). The median volume of transfused red blood cells was 1100 ml in the IABO group compared with 2000 ml in the control group (p < 0.05). 33.3% (11/33) patients in the control group had hemorrhagic shock, and one of them suffered from cardiac arrest intraoperatively because of severe bleeding. However, none of these serious events occurred in the IABO group (p < 0.05). The hysterectomy rate was 70% (7/10) in the IABO group and 63.3% (21/33) in the control group (p > 0.05). No IABO-related complications were observed in the mother and fetus. IABO is an effective and safe method to control intraoperative blood loss and blood transfusion in patients with placenta previa increta/percreta.

Longitudinal parallel compression suture to control postopartum hemorrhage due to placenta previa and accrete.

PubMed

Li, Guang-Tai; Li, Xiao-Fan; Wu, Baoping; Li, Guangrui

2016-04-01

To assess the efficacy and safety of longitudinal parallel compression suture to control heavy postpartum hemorrhage (PPH) in patients with placenta previa/accreta. Fifteen women received a longitudinal parallel compression suture to stop life-threatening PPH due to placenta previa with or without accreta during cesarean section. The suture apposed the anterior and posterior walls of the lower uterine segment together using an absorbable thread A 70-mm round needle with a Number-1 absorbable thread was used. The point of needle entry was 1 cm above the upper margin of the cervix and 1 cm from the right lateral border of the lower segment of the anterior wall. The suture was threaded through the uterine cavity to the serosa of the posterior wall. Then, it was directed upward and threaded from the posterior to the anterior wall at ∼1-2 cm above the upper boundary of the lower uterine segment and 3-cm medial to the right margin of the uterus. Both ends of the suture were tied on the anterior aspect of uterus. The left side was sutured in the same way. The success rate of the procedure was 86.7% (13/15). Two of 15 cases were concurrently administered gauze packing and achieved satisfactory hemostasis. All patients resumed a normal menstrual flow, and no postoperative anatomical or physiological abnormalities related to the suture were observed. Three women achieved further pregnancies after the procedure. Longitudinal parallel compression suture is a safe, easy, effective, practical, and conservative surgical technique to stop intractable PPH from the lower uterine segment, particularly in women who have a cesarean scar and placenta previa/accreta. Copyright © 2016. Published by Elsevier B.V.

Obstetrical Disease Spectrum in China: An Epidemiological Study of 111,767 Cases in 2011

PubMed Central

Luo, Xiao-Lin; Zhang, Wei-Yuan

2015-01-01

Background: No national research on maternal and fetal complications and outcomes has been carried out in the mainland of China in recent years. This study was to provide a scientific basis for better control of obstetrical and neonatal diseases and better allocation of medical resources by analyzing the epidemiological characteristics of obstetrical diseases in the mainland of China. Methods: Hospitalized obstetrical cases from 19 tertiary and 20 secondary hospitals in 14 provinces (nationally representative) during the period January 1, 2011 to December 31, 2011 were randomly selected. The general condition, pregnancy complications, and perinatal outcomes of the patients were studied. Results: The top five medical and surgical complications of pregnant women in the mainland of China were anemia (6.34%), uterine fibroids (2.69%), thyroid disease (1.11%), thrombocytopenia (0.59%), and heart disease (0.59%). The incidences of premature rupture of membranes (PROM), preterm birth, prolonged pregnancy, hypertensive disorders complicating pregnancy (HDCP), multiple pregnancy, intrahepatic cholestasis of pregnancy (ICP), placenta previa, placental abruption, postpartum hemorrhage, and amniotic fluid embolism were 15.27%, 7.04%, 6.71%, 5.35%, 1.57%, 1.22%, 1.14%, 0.54%, 3.26% and 0.06%, respectively. The incidences of anemia and prolonged pregnancy were significantly lower in tertiary than secondary hospitals (P < 0.001), whereas the incidence of uterine fibroids, thyroid diseases, thrombocytopenia, heart disease, PROM, preterm birth, HDCP, multiple pregnancy, ICP, placenta previa, and placental abruption were significantly higher in tertiary than secondary hospitals (P < 0.001). The cesarean section (CS) rate was 54.77%. The newborn sex ratio was 119:100, and 1.03% of the neonates were malformed. The percentages of low birth weight and fetal macrosomia in full-term babies were 2.10% and 7.09%, respectively. Conclusions: The incidence of some obstetrical diseases is still high in the mainland of China. The CS rate is much higher than World Health Organization recommendations, in which CS delivery by maternal request (CDMR) accounted for a large proportion. The government should propose solutions to reduce CS rate, especially the rate of CDMR. Most obstetrical complications have higher incidence in tertiary hospitals compared with secondary hospitals. It is important to manage the health of pregnant women systematically, especially those with high-risk factors. PMID:25947393

Relationship between first trimester aneuploidy screening test serum analytes and placenta accreta.

PubMed

Büke, Barış; Akkaya, Hatice; Demir, Sibel; Sağol, Sermet; Şimşek, Deniz; Başol, Güneş; Barutçuoğlu, Burcu

2018-01-01

The aim of this study is to determine whether there is a relationship between first trimester serum pregnancy-associated plasma protein A (PAPP-A) and free beta human chorionic gonadotropin (fβhCG) MoM values and placenta accreta in women who had placenta previa. A total of 88 patients with placenta previa who had first trimester aneuploidy screening test results were enrolled in the study. Nineteen of these patients were also diagnosed with placenta accreta. As probable markers of excessive placental invasion, serum PAPP-A and fβhCG MoM values were compared in two groups with and without placenta accreta. Patients with placenta accreta had higher statistically significant serum PAPP-A (1.20 versus 0.865, respectively, p = 0.045) and fβhCG MoM (1.42 versus 0.93, respectively, p = 0.042) values than patients without accreta. Higher first trimester serum PAPP-A and fβhCG MoM values seem to be associated with placenta accreta in women with placenta previa. Further studies are needed to use these promising additional tools for early detection of placenta accreta.

Predictors of Perinatal Mortality Associated with Placenta Previa and Placental Abruption: An Experience from a Low Income Country

PubMed Central

Berhan, Yifru

2014-01-01

A retrospective cohort study design was used to assess predictors of perinatal mortality in women with placenta previa and abruption between January 2006 and December 2011. Four hundred thirty-two women (253 with placenta previa and 179 with placental abruption) were eligible for analysis. Binary logistic regression, Kaplan-Meier survival curve, and receiver operating characteristic (ROC) curve were used. On admission, 77% of the women were anaemic (<12 gm/dL) with mean haemoglobin level of 9.0 ± 3.0 gm/dL. The proportion of overall severe anaemia increased from about 28% on admission to 41% at discharge. There were 50% perinatal deaths (neonatal deaths of less than seven days of age and fetal deaths after 28 weeks of gestation). In the adjusted odds ratios, lengthy delay in accessing hospital care, prematurity, anaemia in the mothers, and male foetuses were independent predictors of perinatal mortality. The haemoglobin level at admission was more sensitive and more specific than prematurity in the prediction of perinatal mortality. The proportion of severe anaemia and perinatal mortality was probably one of the highest in the world. PMID:25002975

Update on the renal toxicity of iodinated contrast drugs used in clinical medicine

PubMed Central

Andreucci, Michele; Faga, Teresa; Serra, Raffaele; De Sarro, Giovambattista; Michael, Ashour

2017-01-01

An important side effect of diagnostic contrast drugs is contrast-induced acute kidney injury (CI-AKI; a sudden decrease in renal function) occurring 48–72 hours after injection of a contrast drug that cannot be attributed to other causes. Its existence has recently been challenged, because of some retrospective studies in which the incidence of AKI was not different between subjects who received a contrast drug and those who did not, even using propensity score matching to prevent selection bias. For some authors, only patients with estimated glomerular filtration rate <30 mL/min/1.73 m2 are at significant risk of CI-AKI. Most agree that when renal function is normal, there is no CI-AKI risk. Many experimental studies, however, are in favor of the existence of CI-AKI. Contrast drugs have been shown to cause the following changes: renal vasoconstriction, resulting in a rise in intrarenal resistance (decrease in renal blood flow and glomerular filtration rate and medullary hypoxia); epithelial vacuolization and dilatation and necrosis of proximal tubules; potentiation of angiotensin II effects, reducing nitric oxide (NO) and causing direct constriction of descending vasa recta, leading to formation of reactive oxygen species in isolated descending vasa recta of rats microperfused with a solution of iodixanol; increasing active sodium reabsorption in the thick ascending limbs of Henle’s loop (increasing O2 demand and consequently medullary hypoxia); direct cytotoxic effects on endothelial and tubular epithelial cells (decrease in release of NO in vasa recta); and reducing cell survival, due to decreased activation of Akt and ERK1/2, kinases involved in cell survival/proliferation. Prevention is mainly based on extracellular volume expansion, statins, and N-acetylcysteine; conflicting results have been obtained with nebivolol, furosemide, calcium-channel blockers, theophylline, and hemodialysis. PMID:28579836

Cryopreservation of testicular tissue before long-term testicular cell culture does not alter in vitro cell dynamics.

PubMed

Baert, Yoni; Braye, Aude; Struijk, Robin B; van Pelt, Ans M M; Goossens, Ellen

2015-11-01

To assess whether testicular cell dynamics are altered during long-term culture after testicular tissue cryopreservation. Experimental basic science study. Reproductive biology laboratory. Testicular tissue with normal spermatogenesis was obtained from six donors. None. Detection and comparison of testicular cells from fresh and frozen tissues during long-term culture. Human testicular cells derived from fresh (n = 3) and cryopreserved (n = 3) tissues were cultured for 2 months and analyzed with quantitative reverse-transcription polymerase chain reaction and immunofluorescence. Spermatogonia including spermatogonial stem cells (SSCs) were reliably detected by combining VASA, a germ cell marker, with UCHL1, a marker expressed by spermatogonia. The established markers STAR, ACTA2, and SOX9 were used to analyze the presence of Leydig cells, peritubular myoid cells, and Sertoli cells, respectively. No obvious differences were found between the cultures initiated from fresh or cryopreserved tissues. Single or small groups of SSCs (VASA(+)/UCHL1(+)) were detected in considerable amounts up to 1 month of culture, but infrequently after 2 months. SSCs were found attached to the feeder monolayer, which expressed markers for Sertoli cells, Leydig cells, and peritubular myoid cells. In addition, VASA(-)/UCHL1(+) cells, most likely originating from the interstitium, also contributed to this monolayer. Apart from Sertoli cells, all somatic cell types could be detected throughout the culture period. Testicular tissue can be cryopreserved before long-term culture without modifying its outcome, which encourages implementation of testicular tissue banking for fertility preservation. However, because of the limited numbers of SSCs available after 2 months, further exploration and optimization of the culture system is needed. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Distinct and Cooperative Roles of amh and dmrt1 in Self-Renewal and Differentiation of Male Germ Cells in Zebrafish.

PubMed

Lin, Qiaohong; Mei, Jie; Li, Zhi; Zhang, Xuemei; Zhou, Li; Gui, Jian-Fang

2017-11-01

Spermatogenesis is a fundamental process in male reproductive biology and depends on precise balance between self-renewal and differentiation of male germ cells. However, the regulative factors for controlling the balance are poorly understood. In this study, we examined the roles of amh and dmrt1 in male germ cell development by generating their mutants with Crispr/Cas9 technology in zebrafish. Amh mutant zebrafish displayed a female-biased sex ratio, and both male and female amh mutants developed hypertrophic gonads due to uncontrolled proliferation and impaired differentiation of germ cells. A large number of proliferating spermatogonium-like cells were observed within testicular lobules of the amh -mutated testes, and they were demonstrated to be both Vasa- and PH3-positive. Moreover, the average number of Sycp3- and Vasa-positive cells in the amh mutants was significantly lower than in wild-type testes, suggesting a severely impaired differentiation of male germ cells. Conversely, all the dmrt1 -mutated testes displayed severe testicular developmental defects and gradual loss of all Vasa-positive germ cells by inhibiting their self-renewal and inducing apoptosis. In addition, several germ cell and Sertoli cell marker genes were significantly downregulated, whereas a prominent increase of Insl3-positive Leydig cells was revealed by immunohistochemical analysis in the disorganized dmrt1 -mutated testes. Our data suggest that amh might act as a guardian to control the balance between proliferation and differentiation of male germ cells, whereas dmrt1 might be required for the maintenance, self-renewal, and differentiation of male germ cells. Significantly, this study unravels novel functions of amh gene in fish. Copyright © 2017 by the Genetics Society of America.

Ultrasound pregnancy

MedlinePlus

Pregnancy sonogram; Obstetric ultrasonography; Obstetric sonogram; Ultrasound - pregnancy; IUGR - ultrasound; Intrauterine growth - ultrasound; Polyhydramnios - ultrasound; Oligohydramnios - ultrasound; Placenta previa - ultrasound; Multiple pregnancy - ultrasound; ...

Effectiveness of a Releasing Exercise Program on Anxiety and Self-Efficacy Among Nurses.

PubMed

Chen, Huei-Mein; Wang, Hsiu-Hung; Chiu, Min-Hui

2016-02-01

The purpose of this study was to evaluate the effectiveness of a releasing exercise program (REP) on anxiety and exercise self-efficacy among nurses. The REP consisted of warm-up and tension-releasing exercises and mood adjustment. Ninety-nine nurses (age = 33.38 ± 7.38 years) experiencing anxiety (average Visual Analog Scale for Anxiety [VASA] score of 5.63 ± 1.44 at baseline) were randomly assigned to an experimental group (n = 50) that received 50-min REP sessions 3 times a week or a control group (n = 49) that did not attend REP sessions. The outcome measures were VASA, the Chinese Version of the Beck Anxiety Inventory, and Exercise Self-Efficacy Scale scores. At Weeks 12 and 24, the experimental group had significantly lower anxiety levels and higher exercise self-efficacy scores than the control group. Therefore, the REP effectively reduces anxiety and enhances self-confidence in exercise capability. © The Author(s) 2014.

Contrast-enhanced intravascular ultrasound pulse sequences for bandwidth-limited transducers.

PubMed

Maresca, David; Renaud, Guillaume; van Soest, Gijs; Li, Xiang; Zhou, Qifa; Shung, K Kirk; de Jong, Nico; van der Steen, Antonius F W

2013-04-01

We demonstrate two methods for vasa vasorum imaging using contrast-enhanced intravascular ultrasound, which can be performed using commercial catheters. Plaque neovascularization was recognized as an independent marker of coronary artery plaque vulnerability. IVUS-based methods to image the microvessels available to date require high bandwidth (-6 dB relative frequency bandwidth >70%), which are not routinely available commercially. We explored the potential of ultraharmonic imaging and chirp reversal imaging for vasa vasorum imaging. In vitro recordings were performed on a tissue-mimicking phantom using a commercial ultrasound contrast agent and a transducer with a center frequency of 34 MHz and a -6 dB relative bandwidth of 56%. Acoustic peak pressures <500 kPa were used. A tissue-mimicking phantom with channels down to 200 μm in diameter was successfully imaged by the two contrast detection sequences while the smallest channel stayed invisible in conventional intravascular ultrasound images. Ultraharmonic imaging provided the best contrast agent detection. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. All rights reserved.

Major Determinants of Maternal Near-Miss and Mortality at the Maternity Teaching Hospital, Erbil city, Iraq

PubMed Central

Akrawi, Vian Sabri; Al-Hadithi, Tariq Salman; Al-Tawil, Namir Ghanim

2017-01-01

Objectives To find out the major determinants of maternal near-miss (NM)and maternal deaths (MDs) in Erbil city, Iraq, by comparative analysis of maternal NMs and MDs. Methods We conducted a hospital-based cross-sectional study in the Maternity Teaching Hospital in Erbil city from 1 June to 31 December 2013. All MDs and NMs that occurred in the hospital during the study period were included in the study. Systematic identification of all eligible women was done. This identification included a baseline assessment of the severe pregnancy-related complications using the World Health Organization NM criteria. Results Severe preeclampsia and postpartum hemorrhage (PPH) constituted the highest proportions of complications in women with potentially life-threatening conditions (PLTCs) (30.5% and 30.0%, respectively). The highest mortality indexes were those for ruptured uterus (16.7) and severe complications of placenta previa (14.2). Factors that were significantly associated with MD (compared to NM) were hepatic dysfunction (p = 0.046), multiple/unspecified disorders (p = 0.003), arrival as an emergency condition by ambulance (p = 0.015), and history of previous cesarean section (p = 0.013). Conclusions Severe preeclampsia and PPH are the main complications that lead to PLTCs. Factors found to be associated with MDs are hepatic dysfunction, multiple/unspecified disorders, arrival as an emergency condition by ambulance, and history of a previous cesarean section. PMID:29026470

Impact of grandmultiparity on obstetric outcome in low resource setting.

PubMed

Agrawal, Smriti; Agarwal, Anjoo; Das, Vinita

2011-08-01

This study was undertaken to evaluate the impact of grandmultiparity on obstetric outcome in a low resource setting. Two hundred and eighty-two antenatal grandmultiparous women (parity ≥ 4) were compared with consecutive 564 antenatal women with parity 1-3. There were 13 403 deliveries over the study period from Jan 2006-December 2008 at CSMMU, Lucknow. The prevalence of grandmultipara was 2.3%. Grandmultipara were older (P < 0.001) and more commonly from rural areas (P < 0.001) as compared to the control group. The percentage of Muslims among grandmultipara (23.8%) was higher than among controls (16.5%), P < 0.01. Grandmultipara had significantly higher prevalence of anemia (P < 0.001), malpresentation (P = 0.01) and rupture uterus (P < 0.001). Abruptio placenta, placenta previa and obstructed labor were seen more often in grandmultipara, and the difference was statistically significant (P < 0.01 in each group). There was no difference in terms of mode of delivery, sex of newborn or the prevalence of low birthweight (<2.5 kg) babies. Stillbirths were more common in grandmultiparas (P < 0.001). There was one maternal death in the study group. Grandmultiparity continues to be of grave concern with an adverse impact on obstetric and perinatal outcome. © 2011 The Authors. Journal of Obstetrics and Gynaecology Research © 2011 Japan Society of Obstetrics and Gynecology.

Does cervical ureaplasma/mycoplasma colonization increase the lower uterine segment bleeding risk during cesarean section among patients with placenta previa? A cross-sectional study.

PubMed

Aydogan, P; Kahyaoglu, S; Saygan, S; Kaymak, O; Mollamahmutoglu, L; Danisman, N

2014-08-01

The underlying inflammation of endometrium may impede normal implantation of placenta during pregnancy. Our objective is to show cervical colonization of ureaplasma and/or mycoplasma as a marker of endometritis in pregnancies complicated with placenta previa that can be a risk factor for placenta accreta and peripartum hemorrhage. Cervical cultures for ureaplasma urealyticum and mycoplasma genitalium have been taken from the endocervical region of the cervix of the patients. Subsequent uterine lower segment bleeding suggesting placenta implantation defects have been evaluated during cesarean section. Of 25 patients: ten (40%) had negative cervical cultures for cervical mycoplasma and/or ureaplasma, 9 (36%) were found to be culture positive for cervical ureaplasma, 1 (4%) was found to be culture positive for cervical mycoplasma. Half of the 10 patients with positive cervical cultures for ureaplasma or mycoplasma and 6 of (40%) 15 patients with negative results had experienced lower uterine segment bleeding during cesarean section. Bacterial colonization of cervix in particular with ureaplasma and/or mycoplasma is found to be strongly associated with placenta previa. Before a planned pregnancy, treatment of this infection with appropriate antibiotics is necessary to prevent underlying uterine endometritis that increases the risk for abnormal implantation of placenta.

Retrospective multicenter study of leaving the placenta in situ for patients with placenta previa on a cesarean scar.

PubMed

Miyakoshi, Kei; Otani, Toshimitsu; Kondoh, Eiji; Makino, Shintaro; Tanaka, Mamoru; Takeda, Satoru

2018-03-01

To investigate maternal outcomes after leaving the placenta in situ for placenta accreta spectrum (PAS) disorders in patients with placenta previa on a cesarean delivery scar. The present retrospective study reviewed medical records from women with placenta previa on a cesarean scar underwent perinatal care at secondary- or tertiary-level perinatal centers in Japan between January 1, 2010, and December 31, 2014. Perinatal management was conducted based on each leading obstetrician's discretion. The primary outcome was success of the leaving the placenta in situ approach for PAS disorders (defined as preserving the uterus without hysterectomy). Of 178 eligible centers, 126 (71%) participated in this study; data from 613 patients were included. Of these, 41 had the placenta left in situ owing to PAS disorders and follow-up data were available for 36 women. Leaving the placenta in situ was successful in 25 (69%) patients, with placental resorption occurring postpartum (median 89 days; range 6-510). Hysterectomy was performed for 11 patients, primarily owing to hemorrhage and/or infection (median 30 days; range 0-95 days, postpartum). Leaving the placenta in situ, with close postpartum follow-up for at least several months, could be a uterus-preserving option for patient with PAS disorders. © 2017 International Federation of Gynecology and Obstetrics.

Prophylactic Hypogastric Artery Ballooning in a Patient with Complete Placenta Previa and Increta

PubMed Central

Yi, Kyong Wook; Seo, Tae-Seok; So, Kyeong A; Paek, Yu Chin; Kim, Hai-Joong

2010-01-01

Abnormal attachment of the placenta (Placenta accreta, increta, and percreta) is an uncommon but potentially lethal cause of maternal mortality from massive postpartum hemorrhage. A 33-yr-old woman, who had been diagnosed with a placenta previa, was referred at 30 weeks gestation. On ultrasound, a complete type of placenta previa and multiple intraplacental lacunae, suggestive of placenta accreta, were noted. For further evaluation of the placenta, pelvis MRI was performed and revealed findings suspicious of a placenta increta. An elective cesarean delivery and subsequent hysterectomy were planned for the patient at 38 weeks gestation. On the day of delivery, endovascular catheters for balloon occlusion were placed within the hypogastric arteries, prior to the cesarean section. In the operating room, immediately after the delivery of the baby, bilateral hypogastric arteries were occluded by inflation of the balloons in the catheters previously placed within. With the placenta retained within the uterus, a total hysterectomy was performed in the usual fashion. The occluding balloons were deflated after closure of the vaginal cuff with hemostasis. The patient had stable vital signs and normal laboratory findings during the recovery period; she was discharged six days after delivery without complications. The final pathology confirmed a placenta increta. PMID:20358016

Frequency, Risk Factors, and Adverse Fetomaternal Outcomes of Placenta Previa in Northern Tanzania

PubMed Central

Senkoro, Elizabeth Eliet; Mwanamsangu, Amasha H.; Chuwa, Fransisca Seraphin; Msuya, Sia Emmanuel; Mnali, Oresta Peter

2017-01-01

Background and Objective. Placenta previa (PP) is a potential risk factor for obstetric hemorrhage, which is a major cause of fetomaternal morbidity and mortality in developing countries. This study aimed to determine frequency, risk factors, and adverse fetomaternal outcomes of placenta previa in Northern Tanzania. Methodology. A retrospective cohort study was conducted using maternally-linked data from Kilimanjaro Christian Medical Centre birth registry spanning 2000 to 2015. All women who gave birth to singleton infants were studied. Adjusted odds ratios (ORs) with 95% confidence intervals for risk factors and adverse fetomaternal outcomes associated with PP were estimated in multivariable logistic regression models. Result. A total of 47,686 singleton deliveries were analyzed. Of these, the frequency of PP was 0.6%. Notable significant risk factors for PP included gynecological diseases, alcohol consumption during pregnancy, malpresentation, and gravidity ≥5. Adverse maternal outcomes were postpartum haemorrhage, antepartum haemorrhage, and Caesarean delivery. PP increased odds of fetal Malpresentation and early neonatal death. Conclusion. The prevalence of PP was comparable to that found in past research. Multiple independent risk factors were identified. PP was found to have associations with several adverse fetomaternal outcomes. Early identification of women at risk of PP may help clinicians prevent such complications. PMID:28321338

Topical application of recombinant activated factor VII during cesarean delivery for placenta previa.

PubMed

Schjoldager, Birgit T B G; Mikkelsen, Emmeli; Lykke, Malene R; Præst, Jørgen; Hvas, Anne-Mette; Heslet, Lars; Secher, Niels J; Salvig, Jannie D; Uldbjerg, Niels

2017-06-01

During cesarean delivery in patients with placenta previa, hemorrhaging after removal of the placenta is often challenging. In this condition, the extraordinarily high concentration of tissue factor at the placenta site may constitute a principle of treatment as it activates coagulation very effectively. The presumption, however, is that tissue factor is bound to activated factor VII. We hypothesized that topical application of recombinant activated factor VII at the placenta site reduces bleeding without affecting intravascular coagulation. We included 5 cases with planned cesarean delivery for placenta previa. After removal of the placenta, the surgeon applied a swab soaked in recombinant activated factor VII containing saline (1 mg in 246 mL) to the placenta site for 2 minutes; this treatment was repeated once if the bleeding did not decrease sufficiently. We documented the treatment on video recordings and measured blood loss. Furthermore, we determined hemoglobin concentration, platelet count, international normalized ratio, activated partial thrombin time, fibrinogen (functional), factor VII:clot, and thrombin generation in peripheral blood prior to and 15 minutes after removal of the placenta. We also tested these blood coagulation variables in 5 women with cesarean delivery planned for other reasons. Mann-Whitney test was used for unpaired data. In all 5 cases, the uterotomy was closed under practically dry conditions and the median blood loss was 490 (range 300-800) mL. There were no adverse effects of recombinant activated factor VII and we did not measure factor VII to enter the circulation. Neither did we observe changes in thrombin generation, fibrinogen, activated partial thrombin time, international normalized ratio, and platelet count in the peripheral circulation (all P values >.20). This study indicates that in patients with placenta previa, topical recombinant activated factor VII may diminish bleeding from the placenta site without initiation of systemic coagulation. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

[Vasculitic Peripheral Neuropathies: Clinical Features and Diagnostic Laboratory Tests].

PubMed

Ogata, Katsuhisa

2016-03-01

Vasculitic peripheral neuropathy (VPN) occurs due to ischemic changes of peripheral nerves, resulting from a deficit of vascular blood supply due to damaged vasa nervorum leading to vasculitis. VPN usually manifests as sensorimotor or sensory disturbances accompanied by pain, presenting as a type of multiple mononeuropathy, with a scattered distribution in distal limbs. VPN may also present as a mononeuropathy, distal symmetric polyneuropathy, plexopathy, or radiculopathy. The rapidity of VPN is variable, ranging from days to months, with symptoms occasionally changing with the appearance of new lesions. Careful history taking and neurological examination provides an exact diagnosis. The most common cause of VPN is primary vasculitis predominantly affecting small vessels, including vasa nervorum, anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, and polyarteritis nodosa. Similar vasculitic processes can also result from a systemic collagen disorder or secondary vasculitis. Electrophysiological studies and pathological investigation of biopsied peripheral nerves and muscles are important for diagnosis of vasculitis. Serological tests, including ANCA, are useful for diagnosis of vasculitis. Accurate neurological examinations are essential for diagnosis and evaluation of clinical course.

Splice variants and promoter methylation status of the Bovine Vasa Homology (Bvh) gene may be involved in bull spermatogenesis

PubMed Central

2013-01-01

Background Vasa is a member of the DEAD-box protein family that plays an indispensable role in mammalian spermatogenesis, particularly during meiosis. Bovine vasa homology (Bvh) of Bos taurus has been reported, however, its function in bovine testicular tissue remains obscure. This study aimed to reveal the functions of Bvh and to determine whether Bvh is a candidate gene in the regulation of spermatogenesis in bovine, and to illustrate whether its transcription is regulated by alternative splicing and DNA methylation. Results Here we report the molecular characterization, alternative splicing pattern, expression and promoter methylation status of Bvh. The full-length coding region of Bvh was 2190 bp, which encodes a 729 amino acid (aa) protein containing nine consensus regions of the DEAD box protein family. Bvh is expressed only in the ovary and testis of adult cattle. Two splice variants were identified and termed Bvh-V4 (2112 bp and 703 aa) and Bvh-V45 (2040 bp and 679 aa). In male cattle, full-length Bvh (Bvh-FL), Bvh-V4 and Bvh-V45 are exclusively expressed in the testes in the ratio of 2.2:1.6:1, respectively. Real-time PCR revealed significantly reduced mRNA expression of Bvh-FL, Bvh-V4 and Bvh-V45 in testes of cattle-yak hybrids, with meiotic arrest compared with cattle and yaks with normal spermatogenesis (P < 0.01). The promoter methylation level of Bvh in the testes of cattle-yak hybrids was significantly greater than in cattle and yaks (P < 0.01). Conclusion In the present study, Bvh was isolated and characterized. These data suggest that Bvh functions in bovine spermatogenesis, and that transcription of the gene in testes were regulated by alternative splice and promoter methylation. PMID:23815438

Developmental expression of "germline"- and "sex determination"-related genes in the ctenophore Mnemiopsis leidyi.

PubMed

Reitzel, Adam M; Pang, Kevin; Martindale, Mark Q

2016-01-01

An essential developmental pathway in sexually reproducing animals is the specification of germ cells and the differentiation of mature gametes, sperm and oocytes. The "germline" genes vasa, nanos and piwi are commonly identified in primordial germ cells, suggesting a molecular signature for the germline throughout animals. However, these genes are also expressed in a diverse set of somatic stem cells throughout the animal kingdom leaving open significant questions for whether they are required for germline specification. Similarly, members of the Dmrt gene family are essential components regulating sex determination and differentiation in bilaterian animals, but the functions of these transcription factors, including potential roles in sex determination, in early diverging animals remain unknown. The phylogenetic position of ctenophores and the genome sequence of the lobate Mnemiopsis leidyi motivated us to determine the compliment of these gene families in this species and determine expression patterns during development. Our phylogenetic analyses of the vasa, piwi and nanos gene families show that Mnemiopsis has multiple genes in each family with multiple lineage-specific paralogs. Expression domains of Mnemiopsis nanos, vasa and piwi, during embryogenesis from fertilization to the cydippid stage, were diverse, with little overlapping expression and no or little expression in what we think are the germ cells or gametogenic regions. piwi paralogs in Mnemiopsis had distinct expression domains in the ectoderm during development. We observed overlapping expression domains in the apical organ and tentacle apparatus of the cydippid for a subset of "germline genes," which are areas of high cell proliferation, suggesting that these genes are involved with "stem cell" specification and maintenance. Similarly, the five Dmrt genes show diverse non-overlapping expression domains, with no clear evidence for expression in future gametogenic regions of the adult. We also report on splice variants for two Mnemiopsis Dmrt genes that impact the presence and composition of the DM DNA binding domain for these transcription factors. Our results are consistent with a potential role for vasa, piwi and nanos genes in the specification or maintenance of somatic stem cell populations during development in Mnemiopsis. These results are similar to previous results in the tentaculate ctenophore Pleurobrachia, with the exception that these genes were also expressed in gonads and developing gametes of adult Pleurobrachia. These differences suggest that the Mnemiopsis germline is either specified later in development than hypothesized, the germline undergoes extensive migration, or the germline does not express these classic molecular markers. Our results highlight the utility of comparing expression of orthologous genes across multiple species. We provide the first description of Dmrt expression in a ctenophore, which indicates that Dmrt genes are expressed in distinct structures and regions during development but not in future gametogenic regions, the only sex-specific structure for this hermaphroditic species.

Conventional MRI features for predicting the clinical outcome of patients with invasive placenta

PubMed Central

Chen, Ting; Xu, Xiao-Quan; Shi, Hai-Bin; Yang, Zheng-Qiang; Zhou, Xin; Pan, Yi

2017-01-01

PURPOSE We aimed to evaluate whether morphologic magnetic resonance imaging (MRI) features could help to predict the maternal outcome after uterine artery embolization (UAE)-assisted cesarean section (CS) in patients with invasive placenta previa. METHODS We retrospectively reviewed the MRI data of 40 pregnant women who have undergone UAE-assisted cesarean section due to suspected high risk of massive hemorrhage caused by invasive placenta previa. Patients were divided into two groups based on the maternal outcome (good-outcome group: minor hemorrhage and uterus preserved; poor-outcome group: significant hemorrhage or emergency hysterectomy). Morphologic MRI features were compared between the two groups. Multivariate logistic regression analysis was used to identify the most valuable variables, and predictive value of the identified risk factor was determined. RESULTS Low signal intensity bands on T2-weighted imaging (P < 0.001), placenta percreta (P = 0.011), and placental cervical protrusion sign (P = 0.002) were more frequently observed in patients with poor outcome. Low signal intensity bands on T2-weighted imaging was the only significant predictor of poor maternal outcome in multivariate analysis (P = 0.020; odds ratio, 14.79), with 81.3% sensitivity and 84.3% specificity. CONCLUSION Low signal intensity bands on T2-weighted imaging might be a predictor of poor maternal outcome after UAE-assisted cesarean section in patients with invasive placenta previa. PMID:28345524

Infertility treatment use in relation to selected adverse birth outcomes.

PubMed

Welmerink, Diana B; Voigt, Lynda F; Daling, Janet R; Mueller, Beth A

2010-12-01

To determine whether maternal infertility treatment is associated with adverse outcomes. Population-based cohort study using linked birth certificate-hospital discharge data. Washington State. Live-born singleton infants conceived with infertility treatment between 2003 and 2006 (n = 2,182) and a random sample of live-born singleton infants conceived spontaneously, frequency matched by birth year (n = 10,989). None. Mantel-Haenszel adjusted relative risks (RRs) and 95% confidence intervals (CIs) were computed for low birth weight, delivery at <37 weeks, small for gestational age infants, any malformation, placenta previa, and placenta abruptio. Women with infertility treatment were at increased risk of placental abnormalities, including placenta abruptio (RR, 1.6; 95% CI, 1.1-2.5) and placenta previa (RR, 3.0; 95% CI, 2.0-4.7). Their infants were more likely to be delivered at <37 weeks (RR, 1.7; 95% CI, 1.4-1.9) or weigh <2500 g (RR, 1.4; 95% CI, 1.1-1.7); however, they were not at increased risk of being small for gestational age. An increased risk of malformations was observed in infants born to older women with infertility treatment, but not to younger women. Women using infertility treatment are at increased risk for delivering preterm, placenta previa, and placenta abruptio. Studies with measurement of specific infertility treatments will help identify the mechanisms. Copyright © 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

[Application of lower abdominal aorta balloon occlusion technique by ultrasound guiding during caesarean section in patients with pernicious placenta previa].

PubMed

Wei, L C; Gong, G Y; Chen, J H; Hou, P Y; Li, Q Y; Zheng, Z Y; Su, Y M; Zheng, Y; Luo, C Z; Zhang, K; Xu, T F; Ye, Y H; Lan, Y J; Wei, X M

2018-03-27

Objective: To discuss the feasibility, effect and safety of lower abdominal aorta balloon occlusion technique by ultrasound guiding during caesarean section in patients with pernicious placenta previa. Methods: The clinical data of 40 patients with pernicious placenta previa complicated with placenta accreta from January 2015 to August 2017 in Liuzhou workers hospital were analyzed retrospectively. The study group included 20 cases, which were operated in the way of cesarean section combined lower abdominal aorta balloon occlusion technique by ultrasound guiding, while the control group also included 20 cases, which were operated in the way of the conventional cesarean section without balloon occlusion technique. The bleeding amount, blood transfusion volume, operative total time, hysterectomy and complications of the two groups were compared. Results: The bleeding amount and blood transfusion volume in study group were(850±100)ml and (400±50)ml, which were lower than that of the control group[(2 500±230)ml and (1 500±100)ml], the difference was statistically significant( t =35.624, 16.523, all P <0.05). In addition, the hysterectomy rate in study group was 5%, which was lower than that in the control group(30%), the difference was statistically significant(χ 2 =8.672, P <0.05). And the total time of operation was (2.0±0.5)h in the study group, which was shorter than that in the control group[(3.5±0.4)h]. The difference was statistically significant( t =11.362, P <0.05). No postoperative complications took place in the study group.The blood pressure, heart rate and blood oxygen fluctuated significantly, and the postoperative renal function was significantly reduced in the control group. Conclusions: The lower abdominal aorta balloon occlusion technique by ultrasound guiding during a caesarean section in patients with pernicious placenta previa can effectively control the bleeding during operation, and preserve reproductive function to the utmost degree.Therefore, the technique is safe, feasible, convenient and cheaper, and worthy of being widely applied in clinic.

Residential proximity to major roads and obstetrical complications.

PubMed

Yorifuji, Takashi; Naruse, Hiroo; Kashima, Saori; Murakoshi, Takeshi; Doi, Hiroyuki

2015-03-01

Exposure to air pollution is linked with an increased risk of preterm births. To provide further evidence on this relationship, we evaluated the association between proximity to major roads--as an index for air pollution exposure--and various obstetrical complications. Data were extracted from a database maintained by the perinatal hospital in Shizuoka, Japan. We restricted the analysis to mothers with singleton pregnancies of more than 22 weeks of gestation from 1997 to 2012 (n=19,077). Using the geocoded residential information, each mother was assigned proximity to major roads. We then estimated multivariate adjusted odds ratios and their 95% confidence intervals (CIs) for the effects of proximity to major roads on various obstetrical complications (preeclampsia, gestational diabetes mellitus, placenta abruption, placenta previa, preterm premature rupture of membrane (pPROM), preterm labor, and preterm births). We found positive associations of proximity to major roads with preeclampsia and pPROM. Living within 200 m increased the odds of preeclampsia by 1.3 times (95% CI, 1.0-1.8) and pPROM by 1.6 times (95% CI, 1.1-2.2). Furthermore, living within 200 m increased the odds of preterm births by 1.4 fold (95% CI, 1.2-1.7). Exposure to traffic-related air pollution increased the risk of preeclampsia and pPROM in this study. We propose a mechanism responsible for the association between air pollution and preterm births. Copyright © 2014 Elsevier B.V. All rights reserved.

Matsubara-Takahashi cervix-holding technique for massive postpartum hemorrhage in patients with placenta previa with or without placenta accreta spectrum disorders.

PubMed

Takahashi, Hironori; Ohkuchi, Akihide; Usui, Rie; Suzuki, Hirotada; Baba, Yosuke; Matsubara, Shigeki

2018-03-01

To determine the efficacy and safety of the Matsubara-Takahashi cervix-holding technique (MT-holding) for achieving hemostasis for postpartum hemorrhage (PPH). The present retrospective observational study included data from deliveries that occurred between January 1, 2004, and December 31, 2014, at the Department of Obstetrics and Gynecology, Jichi Medical University, Shimotsuke, Japan. Deliveries were included where patients experienced blood loss greater than 2500 mL and MT-holding was used. The success rates of the technique in patients with placenta accreta spectrum (PAS) disorders and PPH were determined; subsequent pregnancy outcomes were also examined. There were 53 deliveries included in the study; 29 patients had placenta previa and 8 of these patients also had PAS disorders. MT-holding achieved hemostasis in 15 (71%) and 4 (50%) patients with placenta previa without and with PAS disorders, respectively; the placenta was removed in the latter. Overall, MT-holding achieved hemostasis in 40 (75%) deliveries. Of nine patients who became pregnant after this procedure, six went on to have full-term deliveries. MT-holding achieved hemostasis in 50% of patients with PAS disorders and had an overall success rate of 75% for PPH, comparable to other uterus-sparing procedures. MT-holding is suggested as a simple, effective, safe technique available to less-experienced obstetrician; these findings require confirmation in larger studies. © 2017 International Federation of Gynecology and Obstetrics.

Histology of the Urogenital System in the American Bullfrog (Rana catesbeiana), with Emphasis on Male Reproductive Morphology.

PubMed

Rheubert, Justin L; Cook, Hanna E; Siegel, Dustin S; Trauth, Stanley E

2017-10-01

Previous studies have revealed variations in the urogenital system morphology of amphibians. Recently, the urogenital system of salamanders was reviewed and terminology was synonymized across taxa. Discrepancies exist in the terminology describing the urogenital system of anurans, which prompted our group to develop a complete, detailed description of the urogenital system in an anuran species and provide nomenclature that is synonymous with those of other amphibian taxa. In Rana catesbeiana, sperm mature within spermatocysts of the seminiferous tubule epithelia and are transported to a series of intratesticular ducts that exit the testes and merge to form vasa efferentia. Vasa efferentia converge into single longitudinal ducts (Bidder's ducts) on the lateral aspects of the kidneys. Branches from the longitudinal ducts merge with genital kidney renal tubules through renal corpuscles. The nephrons travel caudally and empty into the Wöffian ducts. Similar to salamanders, the caudal portion of the kidneys (termed the pelvic kidneys in salamanders) only possesses nephrons involved in urine formation, not sperm transport. Data from the present study provide a detailed description and synonymous nomenclature that can be used to make future comparative analyses between taxa more efficient.

Omega-3 fatty acids, inflammation and angiogenesis: basic mechanisms behind the cardioprotective effects of fish and fish oils.

PubMed

Massaro, M; Scoditti, E; Carluccio, M A; Campana, M C; De Caterina, R

2010-02-25

Atherosclerosis is now widely accepted to be an inflammatory disease, characterized by degenerative as well as proliferative changes and extracellular accumulation of lipid and cholesterol, in which an ongoing inflammatory reaction plays an important role both in initiation and progression/destabilization, converting a chronic process into an acute disorder. Neovascularization has also been recognized as an important process for the progression/destabilization of atherosclerotic plaques. In fact, vulnerable atherosclerotic plaques prone to rupture are characterized by an enlarged necrotic core, containing an increased number of vasa vasorum, apoptotic macrophages, and more frequent intraplaque haemorrhage. Various functional roles have been assigned to intimal microvessels, however the relationship between the process of angiogenesis and its causal association with the progression and complications of atherosclerosis are still challenging and controversial. In the past 30 years, the dietary intake of omega-3 (n-3) polyunsaturated fatty acids--mainly derived from fish--has emerged as an important way to modify cardiovascular risk through beneficial effects on all stages of atherosclerosis, including plaque angiogenesis. This review specifically focuses on the modulating effects of n-3 fatty acids on molecular events involved in early and late atherogenesis, including effects on endothelial expression of adhesion molecules, as well as pro-inflammatory and pro-angiogenic enzymes. By accumulating in endothelial membrane phospholipids, omega-3 fatty acids have been shown to decrease the transcriptional activation of several genes through an attenuation of activation of the nuclear factor-kappaB system of transcription factors. This occurs secondary to decreased generation of intracellular reactive oxygen species. This series of investigations configures a clear example of nutrigenomics--i.e., how nutrients may affect gene expression, ultimately affecting a wide spectrum of human diseases.

Acute effects and after-effects of acoustic coordinated reset neuromodulation in patients with chronic subjective tinnitus.

PubMed

Adamchic, Ilya; Toth, Timea; Hauptmann, Christian; Walger, Martin; Langguth, Berthold; Klingmann, Ingrid; Tass, Peter Alexander

2017-01-01

Chronic subjective tinnitus is an auditory phantom phenomenon characterized by abnormal neuronal synchrony in the central auditory system. As shown computationally, acoustic coordinated reset (CR) neuromodulation causes a long-lasting desynchronization of pathological synchrony by downregulating abnormal synaptic connectivity. In a previous proof of concept study acoustic CR neuromodulation, employing stimulation tone patterns tailored to the dominant tinnitus frequency, was compared to noisy CR-like stimulation, a CR version significantly detuned by sparing the tinnitus-related pitch range and including substantial random variability of the tone spacing on the frequency axis. Both stimulation protocols caused an acute relief as measured with visual analogue scale scores for tinnitus loudness (VAS-L) and annoyance (VAS-A) in the stimulation-ON condition (i.e. 15 min after stimulation onset), but only acoustic CR neuromodulation had sustained long-lasting therapeutic effects after 12 weeks of treatment as assessed with VAS-L, VAS-A scores and a tinnitus questionnaire (TQ) in the stimulation-OFF condition (i.e. with patients being off stimulation for at least 2.5 h). To understand the source of the long-lasting therapeutic effects, we here study whether acoustic CR neuromodulation has different electrophysiological effects on oscillatory brain activity as compared to noisy CR-like stimulation under stimulation-ON conditions and immediately after cessation of stimulation. To this end, we used a single-blind, single application, cross over design in 18 patients with chronic tonal subjective tinnitus and administered three different 16-minute stimulation protocols: acoustic CR neuromodulation, noisy CR-like stimulation and low frequency range (LFR) stimulation, a CR type stimulation with deliberately detuned pitch and repetition rate of stimulation tones, as control stimulation. We measured VAS-L and VAS-A scores together with spontaneous EEG activity pre-, during- and post-stimulation. Under stimulation-ON conditions acoustic CR neuromodulation and noisy CR-like stimulation had similar effects: a reduction of VAS-L and VAS-A scores together with a decrease of auditory delta power and an increase of auditory alpha and gamma power, without significant differences. In contrast, LFR stimulation had significantly weaker EEG effects and no significant clinical effects under stimulation-ON conditions. The distinguishing feature between acoustic CR neuromodulation and noisy CR-like stimulation were the electrophysiological after-effects. Acoustic CR neuromodulation caused the longest significant reduction of delta and gamma and increase of alpha power in the auditory cortex region. Noisy CR-like stimulation had weaker and LFR stimulation hardly any electrophysiological after-effects. This qualitative difference further supports the assertion that long-term effects of acoustic CR neuromodulation on tinnitus are mediated by a specific disruption of synchronous neural activity. Furthermore, our results indicate that acute electrophysiological after-effects might serve as a marker to further improve desynchronizing sound stimulation.

A National Hero or a Wily Politician? Students' Ideas about the Origins of the Nation in Sweden

ERIC Educational Resources Information Center

Samuelsson, Johan; Wendell, Joakim

2017-01-01

The topic of this article is how primary school students express ideas about the "origins of the nation." The study is based on texts written by Swedish students aged 12-13 about a historical event well embedded in Swedish national mythology, the rise to power of Swedish "founding father" Gustav Vasa. The analysis is inspired…

Placenta: How It Works, What's Normal

MedlinePlus

... toward placentophagy: A brief report. Health Care for Women International. 2015;35:113. Ananth CV, et al. Placental abruption: Clinical features and diagnosis. https://www.uptodate.com/contents/search. Accessed March 20, 2018. Lockwood CJ, et al. Placenta previa: ...

Invasive placenta previa: Placental bulge with distorted uterine outline and uterine serosal hypervascularity at 1.5T MRI - useful features for differentiating placenta percreta from placenta accreta.

PubMed

Chen, Xin; Shan, Ruiqin; Zhao, Lianxin; Song, Qingxu; Zuo, Changting; Zhang, Xinjuan; Wang, Shanshan; Shi, Honglu; Gao, Fei; Qian, Tianyi; Wang, Guangbin; Limperopoulos, Catherine

2018-02-01

To characterise MRI features of invasive placenta previa and to identify specific features for differentiating placenta percreta (PP) from placenta accreta (PA). Forty-five women with PP and 93 women with PA who underwent 1.5T placental MRI were included. Two radiologists independently evaluated the MRI features of invasive placenta previa, including our novel type of placental bulge (i.e. placental bulge type-II, characterized by placental bulge with distorted uterine outline). Pearson's chi-squared or Fisher's two-sided exact test was performed to compare the MRI features between PP and PA. Logistic stepwise regression analysis and the area under the receiver operating characteristic curve (AUC) were performed to select the optimal features for differentiating PP from PA. Significant differences were found in nine MRI features between women with PP and those with PA (P <0.05). Placental bulge type-II and uterine serosal hypervascularity were independently associated with PP (odds ratio = 48.618, P < 0.001; odds ratio = 4.165, P = 0.018 respectively), and the combination of the two MRI features to distinguish PP from PA yielded an AUC of 0.92 for its predictive performance. Placental bulge type-II and uterine serosal hypervascularity are useful MRI features for differentiating PP from PA. • Placental bulge type-II demonstrated the strongest independent association with PP. • Uterine serosal hypervascularity is a useful feature for differentiating PP from PA. • MRI features associated with abnormal vessels increase the risk of massive haemorrhage.

Effect of maternal age on maternal and neonatal outcomes after assisted reproductive technology.

PubMed

Wennberg, Anna Lena; Opdahl, Signe; Bergh, Christina; Aaris Henningsen, Anna-Karina; Gissler, Mika; Romundstad, Liv Bente; Pinborg, Anja; Tiitinen, Aila; Skjærven, Rolv; Wennerholm, Ulla-Britt

2016-10-01

To compare the effect of maternal age on assisted reproductive technology (ART) and spontaneous conception (SC) pregnancies regarding maternal and neonatal complications. Nordic retrospective population-based cohort study. Data from national ART registries were cross-linked with national medical birth registries. Not applicable. A total of 300,085 singleton deliveries: 39,919 after ART and 260,166 after SC. None. Hypertensive disorders in pregnancy (HDP), placenta previa, cesarean delivery, preterm birth (PTB; <37 weeks), low birth weight (LBW; <2,500 g), small for gestational age (SGA), and perinatal mortality (≥28 weeks). Adjusted odds ratios (AORs) were calculated. Associations between maternal age and outcomes were analyzed. The risk of placenta previa (AOR 4.11-6.05), cesarean delivery (AOR 1.18-1.50), PTB (AOR 1.23-2.19), and LBW (AOR 1.44-2.35) was significantly higher in ART than in SC pregnancies for most maternal ages. In both ART and SC pregnancies, the risk of HDP, placenta previa, cesarean delivery, PTB, LBW, and SGA changed significantly with age. The AORs for adverse neonatal outcomes at advanced maternal age (>35 years) showed a greater increase in SC than in ART. The change in risk with age did not differ between ART and SC for maternal outcomes at advanced maternal age. Having singleton conceptions after ART results in higher maternal and neonatal outcome risks overall, but the impact of age seems to be more pronounced in couples conceiving spontaneously. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

[Management of placenta previa and accreta].

PubMed

Kayem, G; Keita, H

2014-12-01

Produce recommendations for the management of placenta previa and placenta accrete. A literature search was conducted using Medline and the Cochrane Library over a period from 1950 to 31/12/2013. Recommendations of the latest scientific societies have also been consulted. In cases of placenta previa, if bleeding episode before 34weeks gestation occurs, a short hospitalization and tocolysis may help stop bleeding (grade C). Vaginal delivery is preferable when the distance between the internal cervical os and the placental edge is greater than 20mm. When this distance is less than 20mm, vaginal delivery is possible (professional consensus). Caesarean section is recommended in cases of placenta overlapping the internal os (professional consensus). Antenatal screening placenta accreta could improve care (EL3). Upon discovery of a placenta accreta during childbirth, it is better to avoid a forced removal of the placenta (grade C). Conservative treatment or cesarean hysterectomy are possible (grade C). The management of placental abnormalities should be planned and managed with a multidisciplinary team (professional consensus). The use of blood-saving techniques such as "cell saver" is possible in situations where early intraoperative bleeding would be>1500mL (grade C). There are no studies that have sufficient methodological value to recommend an anesthetic technique [general anaesthesia (GA) or neuraxial anaesthesia] over another in the context of placental abnormalities (grade B). When a major bleeding risk is identified, GA can be chosen in order to avoid emergency conversions in difficult conditions (professional consensus). Placental insertion abnormalities require anesthetic and obstetric coordination. Delivery must be planned in a suitable structure. Copyright © 2014. Published by Elsevier Masson SAS.

Major Placenta Previa: Rate, Maternal and Neonatal Outcomes Experience at a Tertiary Maternity Hospital, Sohag, Egypt: A Prospective Study

PubMed Central

Ahmed, Salah Roshdy; Aitallah, Abdusaeed; Abdelghafar, Hazem M.

2015-01-01

Introduction Major degree placenta is a serious health issue and is associated with high fetal-maternal morbidity and mortality. Literature from developing countries is scant. Aim To determine the prevalence and maternal and neonatal outcomes among women with major placenta previa (PP). Materials and Methods A prospective descriptive study of 52 singleton pregnancies with PP was evaluated in this study. The study was conducted at Sohag University Hospital, Egypt from January through June 2014. Outcome measures, including the prevalence of PP, maternal and neonatal outcomes, and case-fatality rate. Results The total number of deliveries performed during the study period was 3841, of them, 52 cases were placenta previa. Thus, the prevalence of PP was 1.3%. The mean of previous cesarean scars was 2.2±1.4. Of women with PP, 26.4% (n=14) had placenta accreta. In total, 15.1% (n=8) of women underwent an obstetric hysterectomy. From the total no. of babies, 13.2% (n=7) were delivered fresh stillborn babies. Of the surviving babies (n=45), 20% (n=9) required admission to NICU. The frequencies of bowel and bladder injuries were 3.8% (n=2) and 13.2% (n=7) respectively. There was no maternal death in this study. Conclusion The rate of PP is comparable to previous studies, however, the rate of placenta accreta is high. Also, there are high rates of neonatal mortality and intraoperative complications which can be explained by accreta. The study highlights the need to revise maternity and child health services. PMID:26674539

A novel scoring system for predicting adherent placenta in women with placenta previa.

PubMed

Tanimura, Kenji; Morizane, Mayumi; Deguchi, Masashi; Ebina, Yasuhiko; Tanaka, Utaru; Ueno, Yoshiko; Kitajima, Kazuhiro; Maeda, Tetsuo; Sugimura, Kazuro; Yamada, Hideto

2018-04-01

Placenta previa (PP) is one of the most significant risk factors for adherent placenta (AP). The aim of this study was to evaluate the diagnostic efficacy of a novel scoring system for predicting AP in pregnant women with PP. This prospective cohort study enrolled 175 women with PP. The placenta previa with adherent placenta score (PPAP score) is composed of 2 categories: (1) past history of cesarean section (CS), surgical abortion, and/or uterine surgery; and (2) ultrasonography and magnetic resonance imaging findings. Each category is graded as 0, 1, 2, or 4 points, yielding a total score between 0 and 24. When women with PP had PPAP score ≥8, they were considered to be at a high risk for AP and received placement of preoperative internal iliac artery occlusion balloon catheters. If they were found to have AP during CS, they underwent hysterectomy or placenta removal using advanced bipolar with balloon catheter occlusion. The predictive accuracy of PPAP score was evaluated. In total, 23 of the 175 women with PP were diagnosed as having AP, histopathologically or clinically. Twenty-one of 24 women with PPAP score ≥8 had AP, whereas two of 151 women with PPAP score <8 had AP. The scoring system yielded 91.3% sensitivity, 98.0% specificity, 87.5% positive predictive value, and 98.7% negative predictive value for predicting AP in women with PP. This prospective study demonstrated that PPAP scoring system may be useful for predicting AP in women with PP. Copyright © 2018 Elsevier Ltd. All rights reserved.

Morbidly adherent placenta previa in current practice: prediction and maternal morbidity in a series of 23 women who underwent hysterectomy.

PubMed

Alchalabi, Haifa'a; Lataifeh, Isam; Obeidat, Basil; Zayed, Faheem; Khader, Yousef S; Obeidat, Nail

2014-11-01

To assess the prediction and maternal morbidity of morbidly adherent placenta previa (PP) when currently available management options are used. This is a retrospective study of all women with PP/morbidly adherent placenta previa (MAPP) delivered at our hospital over a period of 9 years. Data were obtained through hospital registry and medical records search. A total of 81 PP were identified, 23 (28.4%) of them had MAPP. All MAPP had previous lower segment cesarean section (LSCS). The following are associated with increased odds of MAPP versus PP, LSCS (OR for each additional LSCS was 2.9 (95% confidence interval: 1.8, 4.5, p ≤ 0.005), age ≥35 years (OR 4.3 (95% CI: 1.4, 12.7, p = 0.008). Anterior or central placenta (OR = 11.6; p = 0.028). Women with previous PP were at risk. Fifteen women were diagnosed by ultrasound [sensitivity 0.65 (0.43, 0.83) and PPV 0.79 (0.54, 0.93)]. MAPP was associated with risk of massive transfusion, bladder injury, DIC and admission to intensive care unit (ICU) (p < 0.005, 0.008, 0.036 and 0.008, respectively). One maternal death was reported in the MAPP group. MAPP is associated with high morbidity and mortality. As the diagnosis is often not certain before delivery, we recommend that all PP and previous LSCS are assumed to be morbidly adherent, and should be managed in properly equipped centers.

Placenta previa

MedlinePlus

... bleeding. This can be deadly to both the mother and baby. If the placenta is near or covering part of the cervix, your provider may recommend: Reducing your activities Bed rest Pelvic rest, which means no sex, no tampons, and no douching Nothing should be ...

[Perioperative management of abdominal aortic balloon occlusion in patients complicated with placenta percteta: a case report].

PubMed

Zeng, Hong; Wang, Yan; Wang, Yang; Guo, Xiang-yang

2015-12-18

When placenta previa complicated with placenta percreta, the exposure of operative field is difficult and the routine methods are difficult to effectively control the bleeding, even causing life-threatening results. A 31-year-old woman, who had been diagnosed with a complete type of placenta previa and placenta percreta with bladder invasion at 34 weeks gestation. Her ultrasound results showed a complete type of placenta previa and there was a loss of the decidual interface between the placenta and the myometrium on the lower part of the uterus, suggestive of placenta increta. For further evaluation of the placenta, pelvis magnetic resonance imaging was performed, which revealed findings suspicious of a placenta percreta. She underwent elective cecarean section at 36 weeks of gestation. Firstly, two ureteral stents were placed into the bilateral ureter through the cystoscope. After the infrarenal abdominal aorta catheter was inserted via the femoral artery (9 F sheath ), subarachnoid anesthesia had been established. A healthy 2 510 g infant was delivered, with Apgar scores of 10 at 1 min and 10 at 5 min. Immediately after the baby was delivered, following which there was massive haemorrhage and general anaesthesia was induced. The balloon catheter was immediately inflated until the wave of dorsal artery disappeared. With the placenta retained within the uterus, a total hysterectomy was performed. The occluding time was 30 min. The intraoperative blood loss was 2 500 mL. The occluding balloon was deflated at the end of the operation. The patient had stable vital signs and normal laboratory findings during the recovery period and the hemoglobin was 116 g/L. She was discharged six days after delivery without intervention-related complications. This case illustrates that temporary occlusion of the infrarenal abdominal aorta using balloon might be a safe and effective treatment option for patients with placenta previa complicated with placenta percreta, who were at high risk for peripartum hemorrhage. Early removal of the endovascular catheter and close postoperative surveillance of the vascular system are required with this procedure to minimize the risk of vascular complications. However, further studies are needed to determine whether the potential benefits of temporary occlusion of the infrarenal abdominal aorta using balloon outweigh the potential risks.

Unidirectional hybrid male sterility from crosses between species A and species B of the taxon Anopheles (Cellia) culicifacies Giles.

PubMed

Miles, S J

1981-02-01

Crosses between species A females and species B males of the taxon Anopheles culicifacies give F1 males with undeveloped testes, reduced vasa deferentia, and apparently normal accessory glands. F1 males from the reciprocal cross, and F1 hybrid females from both reciprocal crosses are fertile, though their fertility is less than that of either parental species

Spermatogenetic disorders in adult rats exposed to tributyltin chloride during puberty.

PubMed

Yu, Wook Joon; Lee, Beom Jun; Nam, Sang Yoon; Kim, Young Chul; Lee, Yong Soon; Yun, Young Won

2003-12-01

Adverse effects of tributyltin (TBT) chloride were investigated on the reproductive system in male adult rats as exposed during puberty. Fifty Sprague-Dawley rats at the age of 35 days were assigned to five different groups: negative control receiving vehicle, methyltestosterone (10 mg/kg B.W.), and TBT chloride treatments (5, 10, and 20 mg/kg B.W.). Animals were treated by oral gavage for ten consecutive days and sacrificed at 5 weeks after final treatment. The treatment of TBT chloride at the high dose of 20 mg/kg B.W. significantly decreased homogenization-resistant testicular sperm counts (p<0.05). The TBT chloride treatment at the doses of 10 and 20 mg/kg B.W. also significantly decreased caudal epididymal sperm counts (p<0.01). Some of motion kinematic parameters (motility, mean angular displacement, lateral head displacement, and dance) of sperms retrieved from vasa deference were significantly decreased in rats treated with the TBT chloride at the dose of 20 mg/kg B.W. (p<0.05). These results provide a further evidence that an exposure to TBT chloride during pubertal period in male rats produces spermatogenic disorders characterized by decreasing testicular and epididymal sperm counts and some motion parameters of sperms in the vasa deference.

Application of optical coherence tomography and high-frequency ultrasound imaging during noninvasive laser vasectomy

NASA Astrophysics Data System (ADS)

Cilip, Christopher M.; Allaf, Mohamad E.; Fried, Nathaniel M.

2012-04-01

A noninvasive approach to vasectomy may eliminate male fear of complications related to surgery and increase its acceptance. Noninvasive laser thermal occlusion of the canine vas deferens has recently been reported. Optical coherence tomography (OCT) and high-frequency ultrasound (HFUS) are compared for monitoring laser thermal coagulation of the vas in an acute canine model. Bilateral noninvasive laser coagulation of the vas was performed in six dogs (n=12 vasa) using a Ytterbium fiber laser wavelength of 1075 nm, incident power of 9.0 W, pulse duration of 500 ms, pulse rate of 1 Hz, and 3-mm-diameter spot. Cryogen spray cooling was used to prevent skin burns during the procedure. An OCT system with endoscopic probe and a HFUS system with 20-MHz transducer were used to image the vas immediately before and after the procedure. Vasa were then excised and processed for gross and histologic analysis for comparison with OCT and HFUS images. OCT provided high-resolution, superficial imaging of the compressed vas within the vas ring clamp, while HFUS provided deeper imaging of the vas held manually in the scrotal fold. Both OCT and high HFUS are promising imaging modalities for real-time confirmation of vas occlusion during noninvasive laser vasectomy.

Optical coherence tomography vs. high-frequency ultrasound during noninvasive laser coagulation of the canine vas deferens

NASA Astrophysics Data System (ADS)

Cilip, Christopher M.; Allaf, Mohamad E.; Fried, Nathaniel M.

2012-02-01

A noninvasive approach to vasectomy may eliminate male fear of complications related to surgery and increase its acceptance. Noninvasive laser thermal occlusion of the canine vas deferens has recently been reported. In this study, optical coherence tomography (OCT) and high-frequency ultrasound (HFUS) are compared for monitoring laser thermal coagulation of the vas in an acute canine model. Bilateral noninvasive laser coagulation of the vas was performed in 6 dogs (n=12 vasa) using a Ytterbium fiber laser wavelength of 1075 nm, incident power of 9.0 W, pulse duration of 500 ms, pulse rate of 1 Hz, and 3-mm-diameter spot. Cryogen spray cooling was used to prevent skin burns during the procedure. An OCT system with endoscopic probe and a HFUS system with 20-MHz transducer were used to image the vas immediately before and after the procedure. Vasa were then excised and processed for gross and histologic analysis for comparison with OCT and HFUS images. OCT provided high-resolution, superficial imaging of the compressed vas within the vas ring clamp, while HFUS provided deeper imaging of the vas held manually in the scrotal fold. Both OCT and high HFUS are promising imaging modalities for real-time confirmation of vas occlusion during noninvasive laser vasectomy.

The Vasa homolog RDE-12 engages target mRNA and multiple Argonaute proteins to promote RNAi in C. elegans

PubMed Central

Shirayama, Masaki; Stanney, William; Gu, Weifeng; Seth, Meetu; Mello, Craig C.

2014-01-01

Summary Argonaute proteins (AGOs) are key nuclease effectors of RNA interference (RNAi) [1]. Although purified AGOs can mediate a single round of target-RNA cleavage in vitro, accessory factors are required for short-interfering (si)RNAs loading and to achieve multiple-target turnover [2, 3]. To identify AGO co-factors we immunoprecipitated the C. elegans AGO WAGO-1, which engages amplified small RNAs during RNAi [4]. These studies identified a robust association between WAGO-1 and a conserved Vasa ATPase-related protein RDE-12. rde-12 mutants are deficient in RNAi including viral suppression, and fail to produce amplified secondary siRNAs and certain endogenous siRNAs (endo-siRNAs). RDE-12 co-localizes with WAGO-1 in germline P-granules and in cytoplasmic and peri-nuclear foci in somatic cells. These findings and our genetic studies suggest that RDE-12 is first recruited to target mRNA by upstream AGOs (RDE-1 and ERGO-1) where it promotes small-RNA amplification and/or WAGO-1 loading. Downstream of these events, RDE-12 forms an RNase-resistant (target mRNA-independent) complex with WAGO-1 and may thus have additional functions in target mRNA surveillance and silencing. PMID:24684931

The Vasa Homolog RDE-12 engages target mRNA and multiple argonaute proteins to promote RNAi in C. elegans.

PubMed

Shirayama, Masaki; Stanney, William; Gu, Weifeng; Seth, Meetu; Mello, Craig C

2014-04-14

Argonaute (AGO) proteins are key nuclease effectors of RNAi. Although purified AGOs can mediate a single round of target RNA cleavage in vitro, accessory factors are required for small interfering RNA (siRNA) loading and to achieve multiple-target turnover. To identify AGO cofactors, we immunoprecipitated the C. elegans AGO WAGO-1, which engages amplified small RNAs during RNAi. These studies identified a robust association between WAGO-1 and a conserved Vasa ATPase-related protein RDE-12. rde-12 mutants are deficient in RNAi, including viral suppression, and fail to produce amplified secondary siRNAs and certain endogenous siRNAs (endo-siRNAs). RDE-12 colocalizes with WAGO-1 in germline P granules and in cytoplasmic and perinuclear foci in somatic cells. These findings and our genetic studies suggest that RDE-12 is first recruited to target mRNA by upstream AGOs (RDE-1 and ERGO-1), where it promotes small RNA amplification and/or WAGO-1 loading. Downstream of these events, RDE-12 forms an RNase-resistant (target mRNA-independent) complex with WAGO-1 and may thus have additional functions in target mRNA surveillance and silencing. Copyright © 2014 Elsevier Ltd. All rights reserved.

High Levels of Hemoglobin Promote Carotid Adventitial Vasa Vasorum Neoangiogenesis in Chronic Kidney Disease

PubMed Central

Martinez-Alonso, Montserrat; Belart, Montserrat; Vilar, Ana; Martín, Marisa; Craver, Lourdes; Betriu, Àngels; Valdivielso, José Manuel; Fernández, Elvira

2017-01-01

Chronic kidney disease (CKD) patients, characterized by traditional and nontraditional risk factors, are prone to develop atheromatosis and thus cardiovascular events and mortality. The angiogenesis of the adventitial vasa vasorum (aVV) surrounding the carotid has been described as the atheromatosis initiator. Therefore, the aim of the study was to (1) evaluate if the carotid aVV in CKD patients increases in comparison to its physiological value of healthy patients; (2) explore which traditional or nontraditional risk factor including inflammation, bone and mineral metabolism, and anemia could be related to the aVV angiogenesis. CKD patients without previous cardiovascular events (44, stages 3-4; 37, stage 5D) and 65 healthy subjects were compared. The carotid aVV and the intima-media thickness (cIMT) were evaluated by ultrasound. CKD patients at stages 3-4 showed higher aVV of the right carotid artery even after adjusting for age. Importantly, a multiple linear regression model showed hemoglobin levels > 12.5 g/dL as the factor for an estimated higher aVV of the right carotid artery. In conclusion, the association of hemoglobin with higher aVV could suggest the role of high hemoglobin in the higher incidence of adverse cardiovascular outcomes in CKD patients. PMID:28133420

Adaptive windowing in contrast-enhanced intravascular ultrasound imaging

PubMed Central

Lindsey, Brooks D.; Martin, K. Heath; Jiang, Xiaoning; Dayton, Paul A.

2016-01-01

Intravascular ultrasound (IVUS) is one of the most commonly-used interventional imaging techniques and has seen recent innovations which attempt to characterize the risk posed by atherosclerotic plaques. One such development is the use of microbubble contrast agents to image vasa vasorum, fine vessels which supply oxygen and nutrients to the walls of coronary arteries and typically have diameters less than 200 µm. The degree of vasa vasorum neovascularization within plaques is positively correlated with plaque vulnerability. Having recently presented a prototype dual-frequency transducer for contrast agent-specific intravascular imaging, here we describe signal processing approaches based on minimum variance (MV) beamforming and the phase coherence factor (PCF) for improving the spatial resolution and contrast-to-tissue ratio (CTR) in IVUS imaging. These approaches are examined through simulations, phantom studies, ex vivo studies in porcine arteries, and in vivo studies in chicken embryos. In phantom studies, PCF processing improved CTR by a mean of 4.2 dB, while combined MV and PCF processing improved spatial resolution by 41.7%. Improvements of 2.2 dB in CTR and 37.2% in resolution were observed in vivo. Applying these processing strategies can enhance image quality in conventional B-mode IVUS or in contrast-enhanced IVUS, where signal-to-noise ratio is relatively low and resolution is at a premium. PMID:27161022

Repeat C-Sections: Is There a Limit?

MedlinePlus

... or completely covering the opening of the cervix (placenta previa). If you've had a prior C-section, your health care provider might recommend an ultrasound to determine the location of your placenta during subsequent pregnancies. Both vaginal and cesarean deliveries ...

Which type of placenta previa requires blood transfusion more frequently? A new concept of indiscernible edge total previa.

PubMed

Baba, Yosuke; Takahashi, Hironori; Ohkuchi, Akihide; Usui, Rie; Matsubara, Shigeki

2016-11-01

During cesarean section (CS) for placenta previa (PP), the size/area/portion of the lower uterine segment occupied by the placenta may affect the bleeding amount and the subsequent need for a blood transfusion (BT). We propose a new concept, indiscernible edge total PP (IEPP), when vaginal ultrasound does not discern the lower placental edge because the placenta covers the visible lower segment. We characterized IEPP, focusing on its allogeneic BT requirement. We classified PP (n = 307) into four types: marginal, partial, discernible edge total PP (DEPP) and IEPP: internal ostium (os)-placental edge distance measurable or unmeasurable on vaginal ultrasound in DEPP or IEPP, respectively. We determined the clinical characteristics according to the four types; the relationship between the intraoperative blood loss and os-edge distance in DEPP; and risk factors for allogeneic BT. The following were significantly higher/larger in cases of IEPP: previous CS; anterior placentation; lacunae; elective cesarean hysterectomy; intraoperative blood loss; autologous BT; allogeneic BT; intensive care unit admission; and an abnormally invasive placenta (AIP). In DEPP, the os-edge distance was weakly correlated with the bleeding amount (r = 0.214). Multivariate logistic regression analysis showed that previous CS, lacunae, AIP and IEPP were independent risk factors for allogeneic BT (odds ratios 3.8, 3.1, 13.8 and 4.6, respectively). After excluding patients undergoing hemostatic procedures during CS, IEPP remained the only independent risk factor for allogeneic BT (odds ratio 5.2). The new concept of IEPP may be useful for predicting BT in CS for patients with PP. © 2016 Japan Society of Obstetrics and Gynecology.

Ex Vivo Machine Perfusion in CTA with a Novel Oxygen Carrier System to Enhance Graft Preservation and Immunologic Outcomes

DTIC Science & Technology

2015-10-01

Pittsburgh, PA 15213 REPORT DATE: October 2015 TYPE OF REPORT: Annual Report PREPARED FOR: U.S. Army Medical Research and Materiel Command...Pittsburgh, Pa 15213-3320 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S) U.S. Army Medical Research and...lamina elastic f. vasa vasorum involvement g. perivascular edema h. erythrocyte extravasation i. leukocyte adhesion j. leukocyte infiltration

Germ plasm localisation of the HELICc of Vasa in Drosophila: analysis of domain sufficiency and amino acids critical for localisation

NASA Astrophysics Data System (ADS)

Wang, Szu-Chieh; Hsu, Hao-Jen; Lin, Gee-Way; Wang, Ting-Fang; Chang, Chun-Che; Lin, Ming-Der

2015-09-01

Formation of the germ plasm drives germline specification in Drosophila and some other insects such as aphids. Identification of the DEAD-box protein Vasa (Vas) as a conserved germline marker in flies and aphids suggests that they share common components for assembling the germ plasm. However, to which extent the assembly order is conserved and the correlation between functions and sequences of Vas remain unclear. Ectopic expression of the pea aphid Vas (ApVas1) in Drosophila did not drive its localisation to the germ plasm, but ApVas1 with a replaced C-terminal domain (HELICc) of Drosophila Vas (DmVas) became germ-plasm restricted. We found that HELICc itself, through the interaction with Oskar (Osk), was sufficient for germ-plasm localisation. Similarly, HELICc of the grasshopper Vas could be recruited to the germ plasm in Drosophila. Nonetheless, germ-plasm localisation was not seen in the Drosophila oocytes expressing HELICcs of Vas orthologues from aphids, crickets, and mice. We further identified that glutamine (Gln) 527 within HELICc of DmVas was critical for localisation, and its corresponding residue could also be detected in grasshopper Vas yet missing in the other three species. This suggests that Gln527 is a direct target of Osk or critical to the maintenance of HELICc conformation.

Differential expression of conserved germ line markers and delayed segregation of male and female primordial germ cells in a hermaphrodite, the leech helobdella.

PubMed

Cho, Sung-Jin; Vallès, Yvonne; Weisblat, David A

2014-02-01

In sexually reproducing animals, primordial germ cells (PGCs) are often set aside early in embryogenesis, a strategy that minimizes the risk of genomic damage associated with replication and mitosis during the cell cycle. Here, we have used germ line markers (piwi, vasa, and nanos) and microinjected cell lineage tracers to show that PGC specification in the leech genus Helobdella follows a different scenario: in this hermaphrodite, the male and female PGCs segregate from somatic lineages only after more than 20 rounds of zygotic mitosis; the male and female PGCs share the same (mesodermal) cell lineage for 19 rounds of zygotic mitosis. Moreover, while all three markers are expressed in both male and female reproductive tissues of the adult, they are expressed differentially between the male and female PGCs of the developing embryo: piwi and vasa are expressed preferentially in female PGCs at a time when nanos is expressed preferentially in male PGCs. A priori, the delayed segregation of male and female PGCs from somatic tissues and from one another increases the probability of mutations affecting both male and female PGCs of a given individual. We speculate that this suite of features, combined with a capacity for self-fertilization, may contribute to the dramatically rearranged genome of Helobdella robusta relative to other animals.

Differential Expression of Conserved Germ Line Markers and Delayed Segregation of Male and Female Primordial Germ Cells in a Hermaphrodite, the Leech Helobdella

PubMed Central

Cho, Sung-Jin; Vallès, Yvonne; Weisblat, David A.

2014-01-01

In sexually reproducing animals, primordial germ cells (PGCs) are often set aside early in embryogenesis, a strategy that minimizes the risk of genomic damage associated with replication and mitosis during the cell cycle. Here, we have used germ line markers (piwi, vasa, and nanos) and microinjected cell lineage tracers to show that PGC specification in the leech genus Helobdella follows a different scenario: in this hermaphrodite, the male and female PGCs segregate from somatic lineages only after more than 20 rounds of zygotic mitosis; the male and female PGCs share the same (mesodermal) cell lineage for 19 rounds of zygotic mitosis. Moreover, while all three markers are expressed in both male and female reproductive tissues of the adult, they are expressed differentially between the male and female PGCs of the developing embryo: piwi and vasa are expressed preferentially in female PGCs at a time when nanos is expressed preferentially in male PGCs. A priori, the delayed segregation of male and female PGCs from somatic tissues and from one another increases the probability of mutations affecting both male and female PGCs of a given individual. We speculate that this suite of features, combined with a capacity for self-fertilization, may contribute to the dramatically rearranged genome of Helobdella robusta relative to other animals. PMID:24217283

Histopathological Differences Between the Anterior and Posterior Brain Arteries as a Function of Aging.

PubMed

Roth, William; Morgello, Susan; Goldman, James; Mohr, Jay P; Elkind, Mitchell S V; Marshall, Randolph S; Gutierrez, Jose

2017-03-01

We tested the hypothesis that posterior brain arteries differ pathologically from anterior brain arteries and that this difference varies with age. Brain large arteries from 194 autopsied individuals (mean age 56±17 years, 63% men, 25% nonwhite, 17% with brain infarcts) were analyzed to obtain the areas of arterial layers and lumen as well as the relative content of elastin, collagen, and amyloid. Visual rating was used to determine the prevalence of atheroma, calcification, vasa vasorum , pattern of intima thickening, and internal elastic lamina gaps. We used multilevel models adjusting for age, sex, ethnicity, vascular risk factors, artery type and location, and multiple comparisons. Of 1362 large artery segments, 5% had vasa vasorum, 5% had calcifications, 15% had concentric intimal thickening, and 11% had atheromas. Posterior brain arteries had thinner walls, less elastin, and more concentric intima thickening than anterior brain arteries. Compared to anterior brain arteries, the basilar artery had higher arterial area encircled by the internal elastic lamina, whereas the vertebral arteries had higher prevalence of elastin loss, concentric intima thickening, and nonatherosclerotic stenosis. In younger individuals, vertebral artery calcifications were more likely than calcification in anterior brain arteries, but this difference attenuated with age. Posterior brain arteries differ pathologically from anterior brain arteries in the degree of wall thickening, elastin loss, and concentric intimal thickening. © 2017 American Heart Association, Inc.

Adaptive windowing in contrast-enhanced intravascular ultrasound imaging.

PubMed

Lindsey, Brooks D; Martin, K Heath; Jiang, Xiaoning; Dayton, Paul A

2016-08-01

Intravascular ultrasound (IVUS) is one of the most commonly-used interventional imaging techniques and has seen recent innovations which attempt to characterize the risk posed by atherosclerotic plaques. One such development is the use of microbubble contrast agents to image vasa vasorum, fine vessels which supply oxygen and nutrients to the walls of coronary arteries and typically have diameters less than 200μm. The degree of vasa vasorum neovascularization within plaques is positively correlated with plaque vulnerability. Having recently presented a prototype dual-frequency transducer for contrast agent-specific intravascular imaging, here we describe signal processing approaches based on minimum variance (MV) beamforming and the phase coherence factor (PCF) for improving the spatial resolution and contrast-to-tissue ratio (CTR) in IVUS imaging. These approaches are examined through simulations, phantom studies, ex vivo studies in porcine arteries, and in vivo studies in chicken embryos. In phantom studies, PCF processing improved CTR by a mean of 4.2dB, while combined MV and PCF processing improved spatial resolution by 41.7%. Improvements of 2.2dB in CTR and 37.2% in resolution were observed in vivo. Applying these processing strategies can enhance image quality in conventional B-mode IVUS or in contrast-enhanced IVUS, where signal-to-noise ratio is relatively low and resolution is at a premium. Copyright © 2016 Elsevier B.V. All rights reserved.

Interobserver repeatability of measurements on computed tomography images of lax canine hip joints from youth to maturity.

PubMed

Lopez, Mandi J; Davis, Kechia M; Jeffrey-Borger, Susan L; Markel, Mark D; Rettenmund, Christy

2009-12-01

To determine interobserver repeatability of measurements on computed tomography (CT) images of lax canine hip joints at different ages and in the presence of degenerative joint disease at maturity. Longitudinal observational investigation. Sibling crossbreed hounds. Pelvic CT was performed at 20, 24, 32, 48, 68, and 104 weeks of age. Measures were performed on 3 contiguous two-dimensional (2D) transverse CT images of both hips at each time point by 3 investigators. Center-edge angle (CEA), horizontal toit externe angle (HTEA), ventral (VASA), dorsal (DASA), and horizontal (HASA) acetabular sector angles, acetabular index (AI), and percent femoral head coverage (CPC) were measured. Interobserver repeatability was quantified with the intraclass correlation coefficient (ICC). Satisfactory repeatability was considered when ICC >or=0.75. DASA, CEA, and CPC were repeatable in all age groups. HASA and HTEA were repeatable for all but 1 time point. At 20 weeks of age, all measures but AI were repeatable, and at 104 weeks of age, DASA, CEA, CPC, and HASA were repeatable. Measures were repeatable in hips with and without degenerative changes with the exceptions of AI and HASA in normal hips and VASA and HTEA in osteoarthritic hips. Most 2D CT measurements examined were repeatable regardless of age or joint disease. Two-dimensional CT measures may augment current techniques for assessing joint changes in lax canine hips.

Adverse obstetric outcomes in pregnant women with uterine fibroids in China: A multicenter survey involving 112,403 deliveries

PubMed Central

Zhao, Rong; Wang, Xin; Zou, Liying; Li, Guanghui; Chen, Yi; Li, Changdong; Zhang, Weiyuan

2017-01-01

Objective To estimate the association between uterine fibroids and adverse obstetric outcomes. Methods This was a retrospective cross-sectional study of 112,403 deliveries from 14 provinces and 39 different hospitals in 2011 in mainland China. We compared pregnancy outcomes in women with and without uterine fibroids who underwent detailed second trimester obstetric ultrasonography during 18 to 22 weeks. Obstetric outcomes include cesarean delivery, breech presentation, preterm delivery, placenta previa, placental abruption, premature rupture of membranes and neonatal birthweight. Univariate analyses and multivariate logistic regression analyses were performed. Results Of 112,403 women who underwent routine obstetric survey, 3,012 (2.68%) women were identified with at least 1 fibroid. By univariate and multivariate analyses, the presence of uterine fibroids was significantly associated with cesarean delivery (Adjusted odds radio [AOR] 1.8, 95% confidence interval [CI] 1.7–2.0), breech presentation (AOR 1.3, 95% CI 1.2–1.5) and postpartum hemorrhage (AOR 1.2, 95% CI 1.1–1.4). The size of uterine fibroids and location in uterus had important effect on the mode of delivery. The rates of PPH were significantly higher with increasing size of the uterine fibroid (P<0.001). And the location of fibroid (intramural, submucosal or subserosal) also have a statistically significant impact on the risk of PPH (5.6% [subserosal] vs 4.7% [submucosal] vs 8.6% [intramural]). Conclusion Pregnant women with uterine fibroids are at increased risk for cesarean delivery, breech presentation and postpartum hemorrhage. And different characteristics of uterine fibroids affect obstetric outcomes through different ways. Such detailed information may be useful in risk-stratifying pregnant women with fibroids. PMID:29136018

The incidence of preeclampsia in ICSI pregnancies

PubMed Central

Ulkumen, BurcuArtunc; Silfeler, DilekBenk; Sofuoglu, Kenan; Silfeler, Ibrahim; Dayicioglu, Vedat

2014-01-01

Objective: We aimed to evaluate the association between infertility etiology in ICSI pregnancies and preeclampsia; besides, we aimed to discuss the effect of the paternal factor in the pathogenesis of preeclampsia. Hypothesis:We hypothesized that preeclampsia is more common in ICSI pregnancies with male factor. It is known that maternal exposure to paternal sperm cells over a time period has a protective effect against preeclampsia. Male partners with azospermia have no sperm cells in their seminal fluid, whose female partners will not be able to develop some protective immunity against preeclampsia. We hypothesized that the infertile couples with male factor (partner with azoospermia and also oligospermia) would be an ideal model to test the partner-specific protective immunity against preeclampsia, as the women had no chance to develop adequate protective immunity via the partner’s sperm exposure. Methods: This Single-center, retrospective study included 508 infertile couples admitted to our IVF center between January 2001 and March 2008. The data regarding the maternal age, etiology of the infertility, the pregnancy rates, abortus ratio and viable pregnancy rates was collected from the case files. Antenatal complications such as preeclampsia, placenta previa, abruptio placenta, premature rupture of membranes, premature labor, oligohydramnios, gestational diabetes, postmaturity, postpartum complications and neonatal outcomes were evaluated via the file records and phone interviewing. The study population was divided into two main groups according to the etiology of infertility. 301 of the study population (group 1) was infertile due to male factor and 207 of the study population (group 2) was female factor and unexplained infertility cases.Group 1 patients were divided further into two subgroups: group 1a included 56 cases in which TESE (testicular sperm extraction) was used to obtain the sperm cells as the male factor was severe and as there was no sperm cells in seminal fluid. Group 1 b consists of 245oligospermic cases who obtained sperm cells via conventional methods. Results: The mean ages of women in Group one and two were 30.22±5.06 and 31.58±4.36 years respectively (p=0.001). 129 cases (42,8%) from group one and 106 cases (51,2%) from Group two ended in first trimester and early second trimester (<24 gestational weeks) pregnancy loss. In group one, only 172 cases of 301 pregnancies passed over 24 weeks of gestational age, whereas in group two, 101 cases of 207 patients passed over 24 gestational weeks. There was no significant difference between two groups regarding chemical pregnancies and early pregnancy loss (p=0.314). There was no significant difference between the groups regarding placenta previa, gestational diabetes, oligo hydramnios and intrauterine growth retardation. One one pregnancy was 1.5 times more vulnerable for preeclampsia. Conclusion: Pregnancies with azoospermic and oligospermic partners had an increased risk for developing preeclampsia. PMID:24639840

Decreased placental and maternal serum TRAIL-R2 levels are associated with placenta accreta.

PubMed

Oztas, Efser; Ozler, Sibel; Ersoy, Ali Ozgur; Ersoy, Ebru; Caglar, Ali Turhan; Uygur, Dilek; Yucel, Aykan; Ergin, Merve; Danisman, Nuri

2016-03-01

TNF-related apoptosis-inducing ligand receptor-2 (TRAIL-R2) is produced both by decidual and trophoblast cells during pregnancy and known to participate in apoptosis. In this study, we aimed to determine and to compare maternal serum and placental TRAIL-R2 levels in patients with placenta accreta, non-adherent placenta previa and in healthy pregnancies. We also aimed to analyze the association of placenta accreta with the occurrence of previous C-sections. A total of 82 pregnant women were enrolled in this case-control study (27 placenta accreta patients, 26 non-adherent placenta previa patients and 29 age-, and BMI-matched healthy, uncomplicated pregnant controls). TRAIL-R2 levels were studied in both maternal serum and placental tissue homogenates. Determining the best predictor(s) which discriminate placenta accreta was analyzed by multiple logistic regression analyses. Adjusted odds ratios and 95% confidence intervals were also calculated. Both placental and serum TRAIL-R2 levels were significantly lower in placenta accreta group (median 34.82 pg/mg and 19.85 pg/mL, respectively) when compared with both non-adherent placenta previa (median 39.24 pg/mg and 25.99 pg/mL, respectively) and the control groups (median 41.62 pg/mg and 25.87 pg/mL, respectively) (p < 0.05). Placental TRAIL-R2 levels and previous cesarean section were found to be significantly associated with placenta accreta (OR: 0.934 95% CI 0.883-0.987, p = 0.016 and OR:7.725 95% CI: 2.717-21.965, p < 0.001, respectively). Placental and serum TRAIL-R2 levels were positively correlated. Decreased levels of placental TRAIL-R2 and previous history of cesarean section were found to be significantly associated with placenta accreta, suggesting a possible role of apoptosis in abnormal trophoblast invasion. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cervical Length in Patients at Risk for Placenta Accreta.

PubMed

Rac, Martha W F; McIntire, Donald D; Wells, C Edward; Moschos, Elysia; Twickler, Diane D

2017-07-01

To evaluate cervical length measurements in women with placenta accreta compared to women with a nonadherent low-lying placenta or placenta previa and evaluate this relationship in terms of vaginal bleeding, preterm labor, and preterm birth. We conducted a retrospective cohort study between 1997 and 2011 of gravidas with more than 1 prior cesarean delivery who had a transvaginal ultrasound examination between 24 and 34 weeks for a low-lying placenta or placenta previa. Cervical length was measured from archived images in accordance with national guidelines by a single investigator, who was blinded to outcomes and ultrasound reports. The diagnosis of placental accreta was based on histologic confirmation. For study purposes, preterm birth was defined as less than 36 weeks, and cervical lengths of 3 cm or less were considered short. Standard statistical analyses were used. A total of 125 patients met inclusion criteria. The cohort was divided into patients with (n = 43 [34%]) and without (n = 82 [66%]) placenta accreta and stratified by gestational age at the ultrasound examinations. Women with placenta accreta had shorter cervical length measurements during their 32- to 34-week ultrasound examinations (mean ± SD, 3.23 ± 0.98 versus 3.95 ± 1.0 cm; P < .01) and were more likely to have a short cervix of 3 cm or less (P = .001). However, these findings did not correlate with the degree of invasion (P = .3), or higher rates of vaginal bleeding and preterm labor (P = .19) resulting in preterm birth before 36 weeks (P = .64). Women with placenta accreta had shorter cervical lengths at 32 to 34 weeks than women with a nonadherent low-lying placenta or placenta previa, but this finding did not correlate with a higher risk of vaginal bleeding or preterm labor resulting in preterm birth before 36 weeks. © 2017 by the American Institute of Ultrasound in Medicine.

Evaluation of interobserver variability and diagnostic performance of developed MRI-based radiological scoring system for invasive placenta previa.

PubMed

Ueno, Yoshiko; Maeda, Tetsuo; Tanaka, Utaru; Tanimura, Kenji; Kitajima, Kazuhiro; Suenaga, Yuko; Takahashi, Satoru; Yamada, Hideto; Sugimura, Kazuro

2016-09-01

To evaluate the interobserver variability and diagnostic performance of a developed magnetic resonance imaging (MRI)-based scoring system for invasive placenta previa. Prenatal MR images of 70 women were retrospectively evaluated, 18 of whom were diagnosed with invasive placenta. The six MR features (dark band on T2 -weighted images, intraplacental abnormal vascularity, placental bulge, heterogeneous placenta, myometrial thinning, and placental protrusion sign) were scored on 5-point Likert scale separately, and the cumulative radiological score (CRS) was defined as the sum of each score. Two more experienced radiologists (readers A and B) and two less experienced residents (readers C and D) calculated the CRS. Interobserver variability was assessed by measuring the intraclass correlation coefficient. Diagnostic performance was evaluated by means of receiver operating characteristic (ROC) analysis. Interobserver variability for CRS was excellent for the more experienced radiologists (0.85), and good for all readers (0.72) and the less experienced residents (0.66). The area under the ROC curve (Az) and accuracy (Acc) for CRS were significantly higher or equivalent to those of other MR features for all readers (Az and Acc for reader A; CRS, 0.92, 91.4%; intraplacental T2 dark band, 0.83, P = 0.009, 81.4%, P = 0.03; intraplacental abnormal vascularity, 0.9, P = 0.3, 90.0%, P = 1.00; placental bulge, 0.81, P = 0.0008, 80.0%, P = 0.02; heterogeneous placenta, 0.85, P = 0.11, 74.3%, P = 0.002; myometrial thinning, 0.84, P = 0.06, 60.0%, P < 0.0001; placental protrusion sign, 0.81, P = 0.01, 81.4%, P = 0.26). This developed MRI-based scoring system demonstrated excellent or good interobserver variability, and good diagnostic performance for invasive placenta previa. J. Magn. Reson. Imaging 2016;44:573-583. © 2016 International Society for Magnetic Resonance in Medicine.

Random placenta margin incision for control hemorrhage during cesarean delivery complicated by complete placenta previa: a prospective cohort study.

PubMed

Fan, Dazhi; Wu, Shuzhen; Ye, Shaoxin; Wang, Wen; Wang, Lijuan; Fu, Yao; Zeng, Meng; Liu, Yan; Guo, Xiaoling; Liu, Zhengping

2018-04-03

Complete placenta previa (CPP) is one of the most problematic types of abnormal placenta, which is further complicated by placenta accreta or percreta that can unexpectedly lead to catastrophic blood loss, infection, multiple complications, emergency hysterectomy, and even death. The present study aimed to assess the efficacy of random placenta margin incision in controlling intraoperative and total blood loss during cesarean section for CPP women. A prospective cohort study, including a total of 100 consecutive pregnant women with CPP, was performed at a tertiary university-affiliated medical center between March 2016 and July 2017. All of them underwent random placenta margin incision, and intraoperative and total blood loss were analyzed. Through antenatal diagnosis using color Doppler, women were further divided into abnormally invasive placenta (AIP) and non-AIP groups, and anterior and posterior placenta groups. The protocol was registered with the Clinical Trial Registry under registration number NCT02695069. Mean maternal age and gestational age at delivery were 32.26 ± 5.03 years old and 36.21 ± 2.07 weeks, respectively. Total duration of the surgical procedure time was 52.50 (42.43-64.00) min. Median estimated intraoperation blood loss was 746.43 (544.44-1092.86) ml. Total blood loss was 875.00 (604.50-1196.67) ml, and 38 (38.0%) had post-partum hemorrhage. The change from baseline in the median hemoglobin level was -0.33 (6.00-13.20). No women underwent hysterectomy due to massive hemorrhage during the study period. No women had an intraoperative urinary bladder injury, postoperative wound infection, and required relaparotomy, owing to intra-abdominal bleeding. The median hospitalization time was 5.41 (4.18-7.58) d. The random placenta margin incision may be a potentially valuable surgical procedure to control the volumes of intraoperative and postoperative blood loss and reduce the incidence of postpartum hemorrhage among women with complete placenta previa.

Corticosteroid involvement in the changes in noradrenergic responsiveness of tissues from rats made hypertensive by short-term isolation

PubMed Central

Bennett, T.; Gardiner, Sheila M.

1978-01-01

1 The responses to noradrenaline and to noradrenergic nerve stimulation of spontaneously beating right atria, electrically driven left atria and vasa deferentia taken from rats made hypertensive by short-term isolation have been compared with the responses of tissues from normotensive, group-housed animals. 2 Adrenocortical activity of isolated animals was assessed by plasma corticosterone determinations and measurement of adrenal weights. 3 The hearts of the isolated animals were weighed and the myocardial contents of water, sodium, potassium and calcium were measured. 4 Spontaneously beating right atria from isolated animals showed a lower resting rate, no difference in the response to nerve stimulation but a greater sensitivity to noradrenaline compared to atria from group-housed animals. 5 Vasa deferentia from isolated animals showed a decreased maximal response to noradrenaline, but no change in noradrenaline sensitivity or in the response to transmural stimulation. 6 There were indications of hyperactivity of the adrenals throughout a 5 week period of isolation, manifest as elevated plasma corticosteroid levels and increased adrenal weights. 7 Myocardial levels of sodium and calcium were elevated at the same time as the tissue level of potassium was reduced, but heart weights did not significantly change. 8 It is possible that adrenal steroid action caused the changes in tissue ionic balance. These ionic disturbances may have been responsible for some of the changes in tissue sensitivity found in the isolated hypertensive animals. PMID:698476

Azoospermia in rabbits following an intravas injection of Vasalgel ™.

PubMed

Waller, Donald; Bolick, David; Lissner, Elaine; Premanandan, Christopher; Gamerman, Gary

2016-01-01

Vasectomy is currently the only long-acting contraceptive option available for men, despite increasing demand and potentially significant positive impacts on human health of additional male contraceptive options. Vasalgel ™ is a high molecular weight hydrogel polymer being developed as a non-hormonal long-acting reversible male contraceptive. Vasalgel consists of styrene-alt-maleic acid dissolved in dimethyl sulfoxide, which is distinct from styrene-alt-maleic anhydride materials previously studied. The goal of the study was to determine the contraceptive efficacy of two test articles with different levels of styrene maleic acid (100 %, and 80 % acid/20 % anhydride). The test articles were injected bilaterally in the vasa deferentia of mature male rabbits. Post-implantation analyses of semen parameters were completed over a 12 month period and compared to baseline measures of sperm concentration, motility and forward progression. Both test articles were effective in blocking the passage of spermatozoa through the vasa deferentia in the 12 subjects completing the study. A significant decrease in sperm concentration occurred following implantation of the test material, with no measurable sperm concentration except for a few samples in one animal that were markedly oligospermic. Vasalgel produced a rapid onset of azoospermia, with no sperm in semen samples collected as early as 29-36 days post-implantation, and was durable over a 12 month period. This study indicated that Vasalgel is an effective non-hormonal long-acting male contraceptive in a rabbit model.

Diffusive shunting of gases and other molecules in the renal vasculature: physiological and evolutionary significance.

PubMed

Ngo, Jennifer P; Ow, Connie P C; Gardiner, Bruce S; Kar, Saptarshi; Pearson, James T; Smith, David W; Evans, Roger G

2016-11-01

Countercurrent systems have evolved in a variety of biological systems that allow transfer of heat, gases, and solutes. For example, in the renal medulla, the countercurrent arrangement of vascular and tubular elements facilitates the trapping of urea and other solutes in the inner medulla, which in turn enables the formation of concentrated urine. Arteries and veins in the cortex are also arranged in a countercurrent fashion, as are descending and ascending vasa recta in the medulla. For countercurrent diffusion to occur, barriers to diffusion must be small. This appears to be characteristic of larger vessels in the renal cortex. There must also be gradients in the concentration of molecules between afferent and efferent vessels, with the transport of molecules possible in either direction. Such gradients exist for oxygen in both the cortex and medulla, but there is little evidence that large gradients exist for other molecules such as carbon dioxide, nitric oxide, superoxide, hydrogen sulfide, and ammonia. There is some experimental evidence for arterial-to-venous (AV) oxygen shunting. Mathematical models also provide evidence for oxygen shunting in both the cortex and medulla. However, the quantitative significance of AV oxygen shunting remains a matter of controversy. Thus, whereas the countercurrent arrangement of vasa recta in the medulla appears to have evolved as a consequence of the evolution of Henle's loop, the evolutionary significance of the intimate countercurrent arrangement of blood vessels in the renal cortex remains an enigma. Copyright © 2016 the American Physiological Society.

Structure of the eastern Seattle fault zone, Washington state: New insights from seismic reflection data

USGS Publications Warehouse

Liberty, L.M.; Pratt, T.L.

2008-01-01

We identify and characterize the active Seattle fault zone (SFZ) east of Lake Washington with newly acquired seismic reflection data. Our results focus on structures observed in the upper 1 km below the cities of Bellevue, Sammamish, Newcastle, and Fall City, Washington. The SFZ appears as a broad zone of faulting and folding at the southern boundary of the Seattle basin and north edge of the Seattle uplift. We interpret the Seattle fault as a thrust fault that accommodates north-south shortening by forming a fault-propagation fold with a forelimb breakthrough. The blind tip of the main fault forms a synclinal growth fold (deformation front) that extends at least 8 km east of Vasa Park (west side of Lake Sammamish) and defines the south edge of the Seattle basin. South of the deformation front is the forelimb break-through fault, which was exposed in a trench at Vasa Park. The Newcastle Hills anticline, a broad anticline forming the north part of the Seattle uplift east of Lake Washington, is interpreted to lie between the main blind strand of the Seattle fault and a backthrust. Our profiles, on the northern limb of this anticline, consistently image north-dipping strata. A structural model for the SFZ east of Lake Washington is consistent with about 8 km of slip on the upper part of the Seattle fault, but the amount of motion is only loosely constrained.

Cryopreservation Causes Genetic and Epigenetic Changes in Zebrafish Genital Ridges

PubMed Central

Riesco, Marta F.; Robles, Vanesa

2013-01-01

Cryopreservation is an important tool routinely employed in Assisted Reproduction Technologies (ARTs) and germplasm banking. For several years, the assessment of global DNA fragmentation seemed to be enough to ensure the integrity of genetic material. However, cryopreservation can produce molecular alterations in key genes and transcripts undetectable by traditional assays, such modifications could interfere with normal embryo development. We used zebrafish as a model to study the effect of cryopreservation on key transcripts and genes. We employed an optimized cryopreservation protocol for genital ridges (GRs) containing primordial germ cells (PGCs) considered one of the best cell sources for gene banking. Our results indicated that cryopreservation produced a decrease in most of the zebrafish studied transcripts (cxcr4b, pou5f1, vasa and sox2) and upregulation of heat shock proteins (hsp70, hsp90). The observed downregulation could not always be explained by promoter hypermethylation (only the vasa promoter underwent clear hypermethylation). To corroborate this, we used human spermatozoa (transcriptionally inactive cells) obtaining a reduction in some transcripts (eIF2S1, and LHCGR). Our results also demonstrated that this effect was caused by freezing/thawing rather than exposure to cryoprotectants (CPAs). Finally, we employed real-time PCR (qPCR) technology to quantify the number of lesions produced by cryopreservation in the studied zebrafish genes, observing very different vulnerability to damage among them. All these data suggest that molecular alterations caused by cryopreservation should be studied in detail in order to ensure the total safety of the technique. PMID:23805321

Resistance of ascending vasa recta to transport of water.

PubMed

Pallone, T L

1991-03-01

A study was undertaken to determine the effect of increasing capillary pressure on volume flux in ascending vasa recta (AVR). In one experiment (group I), AVR were blocked by a single injection of paraffin wax and subjected to free-flow microperfusion at 10 nl/min. Collected fluid was obtained from the perfused vessels by micropuncture. In a second experiment (group II), AVR segments were isolated between two paraffin blocks and perfused at 10 nl/min. In group II, the collection pipette was pressurized to 0, 10, or 20 mmHg. Transmembrane volume flux was determined by measuring the change in concentration of fluorescein isothiocyanate-labeled dextran (2 x 10(6) mol wt) from perfusate to collected fluid. In group I, measurements revealed a capillary pressure of 10.3 +/- 0.5 (SE) mmHg and volume flux of 4.3 +/- 1.0 nl.mm-1.min-1. In group II, volume flux was 1.8 +/- 1.3, 5.9 +/- 1.0, and 11.2 +/- 1.1 nl.mm-1.min-1 at collection pressures of 0, 10, or 20 mmHg, respectively. Based on these data and an AVR diameter of 20 microns, AVR hydraulic conductivity is between 12.5 x 10(-6) and 18.7 x 10(-6) cm.s-1.mmHg-1. The papillary AVR have a high hydraulic conductivity. This is consistent with their role as the sole conduit for removal of water from the papillary interstitium.

Vasa promotes Drosophila germline stem cell differentiation by activating mei-P26 translation by directly interacting with a (U)-rich motif in its 3' UTR.

PubMed

Liu, Niankun; Han, Hong; Lasko, Paul

2009-12-01

Vasa (Vas) is a DEAD-box RNA-binding protein required in Drosophila at several steps of oogenesis and for primordial germ cell (PGC) specification. Vas associates with eukaryotic initiation factor 5B (eIF5B), and this interaction has been implicated in translational activation of gurken mRNA in the oocyte. Vas is expressed in all ovarian germline cells, and aspects of the vas-null phenotype suggest a function in regulating the balance between germline stem cells (GSCs) and their fate-restricted descendants. We used a biochemical approach to recover Vas-associated mRNAs and obtained mei-P26, whose product represses microRNA activity and promotes GSC differentiation. We found that vas and mei-P26 mutants interact, and that mei-P26 translation is substantially reduced in vas mutant cells. In vitro, Vas protein bound specifically to a (U)-rich motif in the mei-P26 3' untranslated region (UTR), and Vas-dependent regulation of GFP-mei-P26 transgenes in vivo was dependent on the same (U)-rich 3' UTR domain. The ability of Vas to activate mei-P26 expression in vivo was abrogated by a mutation that greatly reduces its interaction with eIF5B. Taken together, our data support the conclusion that Vas promotes germ cell differentiation by directly activating mei-P26 translation in early-stage committed cells.

Seeding arterial prostheses with vascular endothelium. The nature of the lining.

PubMed Central

Herring, M B; Dilley, R; Jersild, R A; Boxer, L; Gardner, A; Glover, J

1979-01-01

Arterial prostheses seeded with autogenous vascular endothelium demonstrate a well-organized, cellular, inner lining. To determine the nature of the lining cells, six animals underwent replacement of the infrarenal aorta with Dacron prostheses. During the preparation of three such grafts, endothelium was scraped from the saphenous vein with a steel wool pledget, suspended in chilled Sack's solution, and mixed with blood used to preclot the graft. This suspension was omitted from the three control grafts. After six weeks, the grafts were removed, rinsed and examined. Fluorescent Factor VIII related antigen (F VIII-RA) strongly stained the lining cells. Silver nitrate Haütchen and electron microscopy preparations revealed a lining pattern characteristic of vascular endothelium. Endothelial cell-specific Weibel-Palade bodies were identified in the lining cell cytoplasm. Masson's trichrome staining revealed a relatively collagen-poor connective tissue within the seeded fabric. Transmission electron microscopy disclosed vascular smooth muscle cells between the seeded graft fabric and the lining cells. Vasa vasorum, arising from the outer capsule, penetrated the fabric to supply the inner capsules of the seeded grafts. It is concluded that the cells lining seeded canine arterial prostheses are true vascular endothelium supported by vascular smooth muscle cells, that the lining contains minimal connective tissue, and that vasa vasorum develop. Unseeded control grafts lacked these features. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. Fig. 8. Fig. 9. Fig. 10. PMID:464684

The plasminogen activator system modulates sympathetic nerve function.

PubMed

Schaefer, Ulrich; Machida, Takuji; Vorlova, Sandra; Strickland, Sidney; Levi, Roberto

2006-09-04

Sympathetic neurons synthesize and release tissue plasminogen activator (t-PA). We investigated whether t-PA modulates sympathetic activity. t-PA inhibition markedly reduced contraction of the guinea pig vas deferens to electrical field stimulation (EFS) and norepinephrine (NE) exocytosis from cardiac synaptosomes. Recombinant t-PA (rt-PA) induced exocytotic and carrier-mediated NE release from cardiac synaptosomes and cultured neuroblastoma cells; this was a plasmin-independent effect but was potentiated by a fibrinogen cleavage product. Notably, hearts from t-PA-null mice released much less NE upon EFS than their wild-type (WT) controls (i.e., a 76.5% decrease; P<0.01), whereas hearts from plasminogen activator inhibitor-1 (PAI-1)-null mice released much more NE (i.e., a 275% increase; P<0.05). Furthermore, vasa deferentia from t-PA-null mice were hyporesponsive to EFS (P<0.0001) but were normalized by the addition of rt-PA. In contrast, vasa from PAI-1-null mice were much more responsive (P<0.05). Coronary NE overflow from hearts subjected to ischemia/reperfusion was much smaller in t-PA-null than in WT control mice (P<0.01). Furthermore, reperfusion arrhythmias were significantly reduced (P<0.05) in t-PA-null hearts. Thus, t-PA enhances NE release from sympathetic nerves and contributes to cardiac arrhythmias in ischemia/reperfusion. Because the risk of arrhythmias and sudden cardiac death is increased in hyperadrenergic conditions, targeting the NE-releasing effect of t-PA may have valuable therapeutic potential.

The Diversity of Nanos Expression in Echinoderm Embryos Supports Different Mechanisms in Germ Cell Specification

PubMed Central

Fresques, Tara; Swartz, S. Zachary; Juliano, Celina; Morino, Yoshiaki; Kikuchi, Mani; Akasaka, Koji; Wada, Hiroshi; Yajima, Mamiko; Wessel, Gary M.

2016-01-01

Specification of the germ cell lineage is required for sexual reproduction in all animals. However, the timing and mechanisms of germ cell specification is remarkably diverse in animal development. Echinoderms, such as sea urchins and sea stars, are excellent model systems to study the molecular and cellular mechanisms that contribute to germ cell specification. In several echinoderm embryos tested, the germ cell factor Vasa accumulates broadly during early development and is restricted after gastrulation to cells that contribute to the germ cell lineage. In the sea urchin, however, the germ cell factor Vasa is restricted to a specific lineage by the 32-cell stage. We therefore hypothesized that the germ cell specification program in the sea urchin/Euechinoid lineage has evolved to an earlier developmental time point. To test this hypothesis we determined the expression pattern of a second germ cell factor, Nanos, in four out of five extant echinoderm clades. Here we find that Nanos mRNA does not accumulate until the blastula stage or later during the development of all other echinoderm embryos except those that belong to the Echinoid lineage. Instead, Nanos is expressed in a restricted domain at the 32–128 cell stage in Echinoid embryos. Our results support the model that the germ cell specification program underwent a heterochronic shift in the Echinoid lineage. A comparison of Echinoid and non-Echinoid germ cell specification mechanisms will contribute to our understanding of how these mechanisms have changed during animal evolution. PMID:27402572

The peripartum management of a patient with glutaric aciduria type 1.

PubMed

Ituk, Unyime S; Allen, Terrence K; Habib, Ashraf S

2013-03-01

The management of cesarean delivery for a parturient with placenta previa at 36 weeks' gestation and glutaric aciduria type 1 is presented. The management goal was to prevent encephalopathic crisis by ensuring adequate caloric intake with dextrose infusion and to provide carnitine supplementation and adequate anesthesia. Copyright © 2013 Elsevier Inc. All rights reserved.

JPRS Report, West Europe, Reference Aid, Acronyms and Abbreviations of Portugal

DTIC Science & Technology

1988-09-02

Internacional, Ltd. AML Auto Metralhadora Ligeira AN Assembleia Nacional ANA Aeroportos e Navegacao Aerea ANASD ^ Associacao Nacional dos...de Informacoes ANIC ^ Associacao Nacional dos Industriais de Conservas ANIMEE Associac’ao Nacional dos Industriais de Material Electrico e...Produtos Electricos SIPIP ^ Servico de Informacao Previa ao Investidor Potencial SIRP ^ Sistema de Informac’oes da Repüblica Portuguesa SIS

[Obstetric hysterectomy. Incidence, indications and complications].

PubMed

Vázquez, Juan A Reveles; Rivera, Geannyne Villegas; Higareda, Salvador Hernández; Páez, Fernando Grover; Vega, Carmen C Hernández; Segura, Agustin Patiño

2008-03-01

Obstetric hysterectomy is indicated when patient's life is at risk, and it is a procedure that requires a highly experienced and skilled medical team to solve any complication. To identify incidence, indications, and complications of obstetric hysterectomy within a high-risk population. Transversal, retrospective study from July 1st 2004 to June 30 2006 at Unidad Medica de Alta Especialidad, Hospital de Ginecoobstetricia, Centro Medico Nacional de Occidente, IMSS. There were reviewed 103 patient' files with obstetric hysterectomy. Incidence was calculated, and clinical and socio-demographic characteristics, indications, and complications of obstetric hysterectomy identified and expressed in frequency, percentages, and central tendency measurements. Incidence of obstetric hysterectomy was 8 cases within every 1,000 obstetric consultation. Age average was 31.1 +/- 5.1 years. 72.8% had cesarean surgery history. Main indication was placenta previa associated with placenta accreta (33%), followed by uterine hypotony (22.3%). Complications were hypovolemic shock (56.3%), and vesical injuries (5.8%). There were no maternal deaths. Cesarean history induces higher obstetric hysterectomy incidence in women with high-risk pregnancy, due to its relation to placentation disorders, as placenta previa that increases hemorrhage possibility, and thus, maternal morbidity and mortality.

Can venous ProBNP levels predict placenta accreta?

PubMed

Ersoy, Ali Ozgur; Oztas, Efser; Ozler, Sibel; Ersoy, Ebru; Erkenekli, Kudret; Uygur, Dilek; Caglar, Ali Turhan; Danisman, Nuri

2016-12-01

Placenta previa (PP) is a potential life-threatening pregnancy complication. Pro-brain natriuretic peptide (ProBNP), creatine kinase (CK), cardiac form of CK (CK-MB) and Troponin I are circulatory biomarkers related to cardiac functions. We aimed to determine whether these biomarkers are related to PP and placenta accreta. In this case-control study, fifty-four pregnant women who attended our tertiary care center for perinatology with the diagnosis of PP totalis, and of them, 14 patients with placenta accreta were recruited as the study groups. Forty-six uncomplicated control patients who were matched for age, BMI were also included. Maternal venous ProBNP, CK, CK-MB and Troponin I levels were compared between the three groups. Obstetric history characteristics were comparable among groups, generally. CK and CK-MB levels were similar among three groups. Troponin I levels in the previa and accreta groups were significantly higher than the controls. ProBNP levels in the accreta group were significantly higher than other two groups. The multivariate regression model revealed that ProBNP could predict placental adhesion anomalies. Troponin I and ProBNP levels in PP cases were higher than controls and ProBNP could predict placenta accreta.

Obstetric hysterectomy: a 14-year experience of Rajavithi Hospital 1989-2002.

PubMed

Kovavisarach, Ekachai

2006-11-01

To review and compare the incidence rate of obstetric hysterectomised patients between two seven-year periods. Theperiods were from October 1, 1988 to September 30, 1995 andfrom October P', 1995 to September 30th, 2002. The data included demographic characteristics, indications, possible risk factors, complications, and operative managements. Retrospective analysis of the data that was collected from medical and labor records of the obstetric hysterectomised patientsfrom October 1, 1995 to September 30, 2002, the second seven-year period, compared with those in Pratumthong and Wattanaruangkowit's study from October 1, 1988 to September 30, 1995, the first seven-year period. Between 1998 and 2002, there were 201, 696 total deliveries with 111 obstetric hysterectomies. A significant increase in the average incidence rate of hysterectomy from 0.42 to 0.76/1000 deliveries and maternal age, placenta previa and blood transfusion in the second period compared with the first period (p < 0.05). Postoperative complications and the other risk factors of obstetric hysterectomy were not significant difference. The present study of obstetric hysterectomy demonstrates a significant increase in the incidence of hysterectomised rate, maternal age, blood transfusion, and placenta previa in the second period compared with the first period.

Germ cell specification and ovary structure in the rotifer Brachionus plicatilis.

PubMed

Smith, James M; Cridge, Andrew G; Dearden, Peter K

2010-08-02

The segregation of the germline from somatic tissues is an essential process in the development of all animals. Specification of the primordial germ cells (PGCs) takes place via different strategies across animal phyla; either specified early in embryogenesis by the inheritance of maternal determinants in the cytoplasm of the oocyte ('preformation') or selected later in embryonic development from undifferentiated precursors by a localized inductive signal ('epigenesis'). Here we investigate the specification and development of the germ cells in the rotifer Brachionus plicatilis, a member of the poorly-characterized superphyla Lophotrochozoa, by isolating the Brachionus homologues of the conserved germ cell markers vasa and nanos, and examining their expression using in situ hybridization. Bpvasa and Bpnos RNA expression have very similar distributions in the Brachionus ovary, showing ubiquitous expression in the vitellarium, with higher levels in the putative germ cell cluster. Bpvas RNA expression is present in freshly laid eggs, remaining ubiquitous in embryos until at least the 96 cell stage after which expression narrows to a small cluster of cells at the putative posterior of the embryo, consistent with the developing ovary. Bpnos RNA expression is also present in just-laid eggs but expression is much reduced by the four-cell stage and absent by the 16-cell stage. Shortly before hatching of the juvenile rotifer from the egg, Bpnos RNA expression is re-activated, located in a subset of posterior cells similar to those expressing Bpvas at the same stage. The observed expression of vasa and nanos in the developing B. plicatilis embryo implies an epigenetic origin of primordial germ cells in Rotifer.

Architecture of the human renal inner medulla and functional implications

PubMed Central

Wei, Guojun; Rosen, Seymour; Dantzler, William H.

2015-01-01

The architecture of the inner stripe of the outer medulla of the human kidney has long been known to exhibit distinctive configurations; however, inner medullary architecture remains poorly defined. Using immunohistochemistry with segment-specific antibodies for membrane fluid and solute transporters and other proteins, we identified a number of distinctive functional features of human inner medulla. In the outer inner medulla, aquaporin-1 (AQP1)-positive long-loop descending thin limbs (DTLs) lie alongside descending and ascending vasa recta (DVR, AVR) within vascular bundles. These vascular bundles are continuations of outer medullary vascular bundles. Bundles containing DTLs and vasa recta lie at the margins of coalescing collecting duct (CD) clusters, thereby forming two regions, the vascular bundle region and the CD cluster region. Although AQP1 and urea transporter UT-B are abundantly expressed in long-loop DTLs and DVR, respectively, their expression declines with depth below the outer medulla. Transcellular water and urea fluxes likely decline in these segments at progressively deeper levels. Smooth muscle myosin heavy chain protein is also expressed in DVR of the inner stripe and the upper inner medulla, but is sparsely expressed at deeper inner medullary levels. In rodent inner medulla, fenestrated capillaries abut CDs along their entire length, paralleling ascending thin limbs (ATLs), forming distinct compartments (interstitial nodal spaces; INSs); however, in humans this architecture rarely occurs. Thus INSs are relatively infrequent in the human inner medulla, unlike in the rodent where they are abundant. UT-B is expressed within the papillary epithelium of the lower inner medulla, indicating a transcellular pathway for urea across this epithelium. PMID:26290371

Intracorporeal robot-assisted microsurgical vasovasostomy for the treatment of bilateral vasal obstruction occurring following bilateral inguinal hernia repairs with mesh placement.

PubMed

Trost, Landon; Parekattil, Sijo; Wang, Julie; Hellstrom, Wayne J G

2014-04-01

Various surgical approaches have been described to manage iatrogenic inguinal vasal obstruction, including open microscopic, laparoscopic and robot-assisted techniques. The open and laparoscopic approaches are often limited in cases of extensive inguinal obstruction or inadequate intra-abdominal vasal length. The robotic approach offers novel opportunities to the operating surgeon, including performing microsurgical anastomoses in traditionally challenging locations. To our knowledge we describe the first intracorporeal robot-assisted, microsurgical vasovasostomy for iatrogenic vasal obstruction not amenable to standard microscopic repair. Bilateral intracorporeal robot-assisted microsurgical vasovasostomy was performed. The proximal vasa were transected and obstruction of the distal segments was confirmed. After docking the robot the intracorporeal regions of the vasa were transected at the internal ring. The proximal vasal segments were passed intracorporeally and approximated with 5-zero polypropylene sutures. A standard 2-layer anastomosis was performed intracorporeally using 10-zero/9-zero sutures. Total operative time was 278 minutes. No intraoperative or postoperative complications were noted. Semen analysis 8 weeks after the procedure demonstrated a total volume of 5.4 cc, 8.4 × 10(6) sperm per ml, 45.4 × 10(6) total sperm and 16% motility, consistent with a successful result. To our knowledge this represents the first reported case of intracorporeal outpatient vasovasostomy. These results demonstrate the feasibility of the procedure and highlight unique aspects of the robotic approach, which may offer advantages over the traditional microscope in select cases. Copyright © 2014 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

The diversity of nanos expression in echinoderm embryos supports different mechanisms in germ cell specification.

PubMed

Fresques, Tara; Swartz, Steven Zachary; Juliano, Celina; Morino, Yoshiaki; Kikuchi, Mani; Akasaka, Koji; Wada, Hiroshi; Yajima, Mamiko; Wessel, Gary M

2016-07-01

Specification of the germ cell lineage is required for sexual reproduction in all animals. However, the timing and mechanisms of germ cell specification is remarkably diverse in animal development. Echinoderms, such as sea urchins and sea stars, are excellent model systems to study the molecular and cellular mechanisms that contribute to germ cell specification. In several echinoderm embryos tested, the germ cell factor Vasa accumulates broadly during early development and is restricted after gastrulation to cells that contribute to the germ cell lineage. In the sea urchin, however, the germ cell factor Vasa is restricted to a specific lineage by the 32-cell stage. We therefore hypothesized that the germ cell specification program in the sea urchin/Euechinoid lineage has evolved to an earlier developmental time point. To test this hypothesis we determined the expression pattern of a second germ cell factor, Nanos, in four out of five extant echinoderm clades. Here we find that Nanos mRNA does not accumulate until the blastula stage or later during the development of all other echinoderm embryos except those that belong to the Echinoid lineage. Instead, Nanos is expressed in a restricted domain at the 32-128 cell stage in Echinoid embryos. Our results support the model that the germ cell specification program underwent a heterochronic shift in the Echinoid lineage. A comparison of Echinoid and non-Echinoid germ cell specification mechanisms will contribute to our understanding of how these mechanisms have changed during animal evolution. © 2016 Wiley Periodicals, Inc.

An Integrated System for Superharmonic Contrast-Enhanced Ultrasound Imaging: Design and Intravascular Phantom Imaging Study.

PubMed

Li, Yang; Ma, Jianguo; Martin, K Heath; Yu, Mingyue; Ma, Teng; Dayton, Paul A; Jiang, Xiaoning; Shung, K Kirk; Zhou, Qifa

2016-09-01

Superharmonic contrast-enhanced ultrasound imaging, also called acoustic angiography, has previously been used for the imaging of microvasculature. This approach excites microbubble contrast agents near their resonance frequency and receives echoes at nonoverlapping superharmonic bandwidths. No integrated system currently exists could fully support this application. To fulfill this need, an integrated dual-channel transmit/receive system for superharmonic imaging was designed, built, and characterized experimentally. The system was uniquely designed for superharmonic imaging and high-resolution B-mode imaging. A complete ultrasound system including a pulse generator, a data acquisition unit, and a signal processing unit were integrated into a single package. The system was controlled by a field-programmable gate array, on which multiple user-defined modes were implemented. A 6-, 35-MHz dual-frequency dual-element intravascular ultrasound transducer was designed and used for imaging. The system successfully obtained high-resolution B-mode images of coronary artery ex vivo with 45-dB dynamic range. The system was capable of acquiring in vitro superharmonic images of a vasa vasorum mimicking phantom with 30-dB contrast. It could detect a contrast agent filled tissue mimicking tube of 200 μm diameter. For the first time, high-resolution B-mode images and superharmonic images were obtained in an intravascular phantom, made possible by the dedicated integrated system proposed. The system greatly reduced the cost and complexity of the superharmonic imaging intended for preclinical study. Significant: The system showed promise for high-contrast intravascular microvascular imaging, which may have significant importance in assessment of the vasa vasorum associated with atherosclerotic plaques.

Detection of increased vasa vasorum in artery walls: improving CT number accuracy using image deconvolution

NASA Astrophysics Data System (ADS)

Rajendran, Kishore; Leng, Shuai; Jorgensen, Steven M.; Abdurakhimova, Dilbar; Ritman, Erik L.; McCollough, Cynthia H.

2017-03-01

Changes in arterial wall perfusion are an indicator of early atherosclerosis. This is characterized by an increased spatial density of vasa vasorum (VV), the micro-vessels that supply oxygen and nutrients to the arterial wall. Detection of increased VV during contrast-enhanced computed tomography (CT) imaging is limited due to contamination from blooming effect from the contrast-enhanced lumen. We report the application of an image deconvolution technique using a measured system point-spread function, on CT data obtained from a photon-counting CT system to reduce blooming and to improve the CT number accuracy of arterial wall, which enhances detection of increased VV. A phantom study was performed to assess the accuracy of the deconvolution technique. A porcine model was created with enhanced VV in one carotid artery; the other carotid artery served as a control. CT images at an energy range of 25-120 keV were reconstructed. CT numbers were measured for multiple locations in the carotid walls and for multiple time points, pre and post contrast injection. The mean CT number in the carotid wall was compared between the left (increased VV) and right (control) carotid arteries. Prior to deconvolution, results showed similar mean CT numbers in the left and right carotid wall due to the contamination from blooming effect, limiting the detection of increased VV in the left carotid artery. After deconvolution, the mean CT number difference between the left and right carotid arteries was substantially increased at all the time points, enabling detection of the increased VV in the artery wall.

Angioarchitecture of the bovine spermatic cord.

PubMed

Polguj, Michał; Jȩdrzejewski, Kazimierz S; Topol, Mirosław

2011-04-01

We described the topography and morphometry of the testicular artery, pampiniform plexus veins, and indirect connections between them in the spermatic cord of the bull. Sixty microcorrosive casts of bovine spermatic cords were analyzed macroscopically, by stereomicroscopy, and by scanning electron microscopy. The average size of the testicles was 94.6 × 49.7 × 54.7 mm. The testicular artery formed a superiorly pointed cone-like structure with its base fixed to the proximal part of the gonad. The artery gave off one or two branches to the head of epididymis and to the deferens duct. The pampiniform plexus originated from intra-tunical veins. Veins of the pampiniform plexus were of smaller diameter but larger number than intra-tunical ones. The density of the veins of the pampiniform plexus was 9.37 ± 1.07 mm(-2) . The testicular vein began 90-121 mm above the superior pole of the testis. In 2.9% of specimens, the testicular vein was doubled. Numerous anastomoses among veins of pampiniform plexus were observed. Additionally, indirect anastomoses between the testicular artery and pampiniform plexus veins formed by the capillary network of the vasa vasorum of the testicular artery were visualized by scanning electron microscopy. In all cases, narrowings in the casts of the precapillary vessel were observed. We also documented the vasa vasorum of the testicular artery in bulls. The density of these vessels was 22.87 ± 11.48 mm(-2) . The indirect arteriovenous connections together with the presence of circular constrictions of the lumen in precapillary vessels may play a role in testicular blood flow regulation. Copyright © 2011 Wiley-Liss, Inc.

Noninvasive laser coagulation of the canine vas deferens, in vivo

NASA Astrophysics Data System (ADS)

Cilip, Christopher M.; Ross, Ashley E.; Jarow, Jonathan P.; Fried, Nathaniel M.

2010-02-01

Development of a noninvasive vasectomy technique may eliminate male fear of complications (incision, bleeding, infection, and scrotal pain) and result in a more popular procedure. This study builds upon previously reported ex vivo tissue studies by exploring acute and short-term chronic in vivo canine studies. Isolation of the canine vas was achieved using a conventional vas ring clamp method. No perforation of the scrotal skin was necessary to occlude the vas. Laser radiation with a wavelength of 1075 nm, average power of 11.2 W, 500-ms pulse duration, 0.5 Hz pulse rate, and 3-mm-diameter spot was synchronized with cryogen spray cooling of the scrotal skin surface in a total of 8 dogs (n = 16 vasa) for a treatment time of 60 s. Burst pressure measurements were conducted at Days 0 and 21 (n = 8 vasa each day) to quantify the strength of vas closure. The vas was successfully thermally occluded in 15/16 (94%) procedures with 14/15 (93%) vas recording burst pressures above ejaculation pressure. One vas was not present, and another vas recorded a bursting pressure below ejaculation pressure. The coagulated vas bursting pressure averaged 283 +/- 34 mm Hg at Day 0 and 260 +/- 77 mm Hg at Day 21, significantly higher than reported vas ejaculation pressures of 136 +/- 29 mm Hg. Minor scrotal skin burns were observed during the recovery period. Noninvasive thermal occlusion of the vas is feasible in an in vivo canine model. Elimination of minor skin burns and longer term chronic in vivo canine studies are needed to confirm azospermia after vas occlusion without recanalization.

Orthotropic creep in polyethylene glycol impregnated archaeological oak from the Vasa ship - Results of creep experiments in a museum-like climate

NASA Astrophysics Data System (ADS)

Vorobyev, Alexey; van Dijk, Nico P.; Kristofer Gamstedt, E.

2018-02-01

Creep in archaeological oak samples and planks from the Vasa ship impregnated with polyethylene glycol (PEG) has been studied in museum-like climate. Creep studies of duration up to three years have been performed in nearly constant relative humidity and temperature of the controlled museum climate. Cubic samples were subjected to compressive creep tests in all orthotropic directions. Additionally, the creep behaviour of planks with and without PEG and of recent oak was tested in four-point bending. The experimental results have been summarised and also compared with reference results from recent oak wood. The effect of variable ambient conditions on creep and mass changes is discussed. The experimental results of creep in the longitudinal direction showed deformations even for the low stresses. There is relatively much more scatter in creep behaviour, and not all samples showed linear viscoelastic response. The creep in radial and tangential directions of the cubes and the plank samples showed a strong dependency on the ambient conditions. Some samples showed expansion for decreasing moisture content, possibly caused by the thermal expansion of the PEG component. For the planks, increasing creep deformation was observed induced by changing ambient conditions. Such behaviour may be related to e.g. oscillations in ambient conditions and presence of PEG in the wood cell wall and cell lumen. The behaviour of PEG archaeological wood depends on the level of deterioration that occurred over centuries. However, although the findings presented here apply to this specific case, they provide a unique view on such wood.

Germ cell differentiation and proliferation in the developing testis of the South American plains viscacha, Lagostomus maximus (Mammalia, Rodentia).

PubMed

Gonzalez, C R; Muscarsel Isla, M L; Fraunhoffer, N A; Leopardo, N P; Vitullo, A D

2012-08-01

Cell proliferation and cell death are essential processes in the physiology of the developing testis that strongly influence the normal adult spermatogenesis. We analysed in this study the morphometry, the expression of the proliferation cell nuclear antigen (PCNA), cell pluripotency marker OCT-4, germ cell marker VASA and apoptosis in the developing testes of Lagostomus maximus, a rodent in which female germ line develops through abolished apoptosis and unrestricted proliferation. Morphometry revealed an increment in the size of the seminiferous cords with increasing developmental age, arising from a significant increase of PCNA-positive germ cells and a stable proportion of PCNA-positive Sertoli cells. VASA showed a widespread cytoplasmic distribution in a great proportion of proliferating gonocytes that increased significantly at late development. In the somatic compartment, Leydig cells increased at mid-development, whereas peritubular cells showed a stable rate of proliferation. In contrast to other mammals, OCT-4 positive gonocytes increased throughout development reaching 90% of germ cells in late-developing testis, associated with a conspicuous increase in circulating FSH from mid- to late-gestation. TUNEL analysis was remarkable negative, and only a few positive cells were detected in the somatic compartment. These results show that the South American plains viscacha displays a distinctive pattern of testis development characterized by a sustained proliferation of germ cells throughout development, with no signs of apoptosis cell demise, in a peculiar endocrine in utero ambiance that seems to promote the increase of spermatogonial number as a primary direct effect of FSH.

[Application of uterine lower part breakwater-like suture operation in placenta previa].

PubMed

Zhao, Y; Zhu, J W; Wu, D; Wang, Q H; Lu, S S; Liu, X X; Zou, L

2018-04-25

Objective: To explore the efficacy and safety of uterine lower posterior wall breakwater-like suture technique in controlling the intraoperative bleeding of placenta previa. Methods: From June 2016 to June 2017, 47 patients were diagnosed placenta previa in Union Hospital, Tongji Medical College of Huazhong University of Science and Technology. Posterior wall breakwater-like suture technique was used preferentially, as for cases with poor myometrium layer, lower anterior wall stitch suture was used at the same time. Bilateral descending branches of uterine artery ligation and Cook balloon compression of uterine lower segment was conducted when necessary. The clinic data of the 47 cases were analyzed. Results: Thirty cases (63.8, 30/47) were diagnosed placenta inccreta or percreta by ultrasound or MRI preoperatively. Senventeen cases were diagnosed as placenta accreta (36.2%, 17/47) . Thirty-four cases had the previous history of cesarean section. The average cervical canal length of 47 patients was (2.8±0.9) cm. There were 19 cases (40.4%,19/47) with 1 time posterior wall breakwater-like sutured and 16 cases (34.0%,16/47) with 2 or 3 times posterior wall breakwater-like sutured; 12 cases (25.5%,12/47) were treated with anterior wall stitch suture simultaneously.Ten cases (21.3%, 10/47) underwent uterine artery ligation, 17 cases (36.2%, 17/47) underwent COOK balloon compression on the staxis surface of lower segment. None of them had postpartum hemorrhage or performed internal iliac artery embolization. The median blood loss in the operation was 700 ml, the percentiles 25 was 500 ml, and the percentiles 75 was 1 200 ml. The blood loss ≥1 000 ml in 18 (38.3%, 18/47) patients,and the most serious one was 2 500 ml. The median blood transfusion volume (including allogenetic transfusion and autotransfusion) was 450 ml, the percentiles 25 was 228 ml, and the percentiles 75 was 675 ml. The average vaginal bleeding volume was (150±63) ml first day after operation. The mean hospitalization time was (4.7±1.0) days. The mean gestational weeks of pregnancy termination was (36.1±1.5) weeks, and the mean birth weight of newborns was (2 817±492) g. Apgar score:1-minute 7.8±1.1, 5-minute 8.9±0.8. No neonatal death, 16 cases were transferred to neonatal ICU (34.0%, 16/47) mainly for premature delivery and low birth weight. No complication was found in 6 months post-operation. Conclusions: Uterine posterior wall breakwater-like suture technique is a simple, safe and effective way in controlling intraoperative bleeding of placental previa.Lower anterior wall stitch suture could effectively stop bleeding and restore the normal uterine shape. Combined application of various methods could significantly reduce the incidence of postpartum hemorrhage and hysterectomy, and improve maternal and fetal prognosis.

The Computational Fluid Dynamics Rupture Challenge 2013—Phase I: prediction of rupture status in intracranial aneurysms.

PubMed

Janiga, G; Berg, P; Sugiyama, S; Kono, K; Steinman, D A

2015-03-01

Rupture risk assessment for intracranial aneurysms remains challenging, and risk factors, including wall shear stress, are discussed controversially. The primary purpose of the presented challenge was to determine how consistently aneurysm rupture status and rupture site could be identified on the basis of computational fluid dynamics. Two geometrically similar MCA aneurysms were selected, 1 ruptured, 1 unruptured. Participating computational fluid dynamics groups were blinded as to which case was ruptured. Participants were provided with digitally segmented lumen geometries and, for this phase of the challenge, were free to choose their own flow rates, blood rheologies, and so forth. Participants were asked to report which case had ruptured and the likely site of rupture. In parallel, lumen geometries were provided to a group of neurosurgeons for their predictions of rupture status and site. Of 26 participating computational fluid dynamics groups, 21 (81%) correctly identified the ruptured case. Although the known rupture site was associated with low and oscillatory wall shear stress, most groups identified other sites, some of which also experienced low and oscillatory shear. Of the 43 participating neurosurgeons, 39 (91%) identified the ruptured case. None correctly identified the rupture site. Geometric or hemodynamic considerations favor identification of rupture status; however, retrospective identification of the rupture site remains a challenge for both engineers and clinicians. A more precise understanding of the hemodynamic factors involved in aneurysm wall pathology is likely required for computational fluid dynamics to add value to current clinical decision-making regarding rupture risk. © 2015 by American Journal of Neuroradiology.

The Impact of Interpersonal Style on Ruptures and Repairs in the Therapeutic Alliance Between Offenders and Therapists in Sex Offender Treatment.

PubMed

Watson, Rachael; Thomas, Stuart; Daffern, Michael

2017-10-01

The therapeutic relationship is a critical component of psychological treatment. Strain can occur in the relationship, particularly when working with offenders, and more specifically, those offenders with interpersonal difficulties; strain can lead to a rupture, which may affect treatment participation and performance. This study examined ruptures in the therapeutic relationship in sexual offenders participating in offense-focused group treatment. Fifty-four sex offenders rated the therapeutic alliance at the commencement and completion of treatment; at the completion of treatment, they also reported on the occurrence of ruptures and whether they believed these ruptures were repaired. Ruptures were separated by type, according to severity-Each relationship was therefore characterized as experiencing no rupture, a minor rupture, or a major rupture. Offender characteristics including interpersonal style (IPS) and psychopathy were assessed at the commencement of treatment; their relationship with ruptures was examined. Results revealed that more than half of the offenders (approximately 55%) experienced a rupture in the therapeutic alliance, with one in four of these ruptures remaining unresolved. Offenders who did not report a rupture rated the therapeutic alliance significantly higher at the end of treatment compared with those offenders who reported a rupture that was not repaired. Offenders who reported a major rupture in the therapeutic relationship were higher in interpersonal hostility and hostile-dominance. No interpersonal or offense-specific factors affected the likelihood of a rupture repair.

Fatal hemothorax following management of an esophageal foreign body.

PubMed

Cohn, Leah A; Stoll, Melissa R; Branson, Keith R; Roudabush, Alice D; Kerl, Marie E; Langdon, Paige F; Johannes, Chad M

2003-01-01

A 10.8-year-old, spayed female toy poodle presented with an esophageal foreign body. The foreign body was removed endoscopically, and a gastrostomy tube was placed to provide nutritional support during esophageal healing. The gastrostomy tube was later removed by endoscopic retrieval of the bulb through the esophagus. Immediately afterward, the dog developed hemothorax and eventually died. It was determined that many small arterial branches were avulsed from the aorta. The involved sections of aorta histopathogically evidenced medial necrosis, which was believed to be related to a prior disruption of blood flow through the vasa vasorum.

Testicular cell-conditioned medium supports embryonic stem cell differentiation toward germ lineage and to spermatocyte- and oocyte-like cells.

PubMed

Shah, Syed M; Saini, Neha; Singh, Manoj K; Manik, Radheysham; Singla, Suresh K; Palta, Prabhat; Chauhan, Manmohan S

2016-08-01

Testicular cells are believed to secrete various growth factors that activate signaling pathways finally leading to gametogenesis. In vitro gametogenesis is an obscure but paramountly important task primarily because of paucity of the precursor cells and first trimester gonadal tissues. To overcome these limitations for development of in vitro gametes, the present study was designed to induce differentiation of buffalo embryonic stem (ES) cells into germ lineage cells on stimulation by testicular cell-conditioned medium (TCM), on the basis of the assumption that ES cells have the intrinsic property to differentiate into any cell type and TCM would provide the necessary growth factors for differentiation toward germ cell lineage. For this purpose, buffalo ES cells were differentiated as embryoid bodies (EB) in floating cultures and as monolayer adherent cultures in different doses (10%, 20%, and 40%) of TCM for different culture intervals (4, 8, and 14 days), to identify the optimum dose-and-time period. We observed that 40% TCM dose induces highest expression of primordial germ cell-specific (DAZL, VASA, and PLZF), meiotic (SYCP3, MLH1, TNP1/2, and PRM2), spermatocyte-specific (BOULE and TEKT1), and oocyte-specific genes (GDF9 and ZP2/3) for a culture period of 14 days under both floating and adherent differentiation. Immunocytochemical analysis of EBs and adherent cultures revealed presence of primordial germ cell markers (c-KIT, DAZL, and VASA), meiotic markers (SYCP3, MLH1 and PROTAMINE1), spermatocyte markers (ACROSIN and HAPRIN), and oocyte markers (GDF9 and ZP4), indicating progression into post-meiotic gametogenesis. The detection of germ cell-specific proteins in Day 14 EBs like VASA, GDF9, and ZP4 by Western blotting further confirmed germ lineage differentiation. The significantly lower (P < 0.05) concentration of 5-methyl-2-deoxycytidine in optimally differentiated EBs is suggestive of the process of methylation erasure. Oocyte-like structures obtained in monolayer differentiation had a big nucleus and a surrounding ZP4 coat, the unique attributes of a female gamete. These oocyte-like structures, in extended cultures, showed embryonic development and progressed through two-cell, four-cell, eight-cell, morula, and blastocyst-like structures, indicative of their developmental competence. This, as per our knowledge, is first such study in higher mammals, especially farm animals, and assumes significance for its potential use in transgenic animal production, elite animal conservation and propagation, augmentation of reproductive performance in poor breeding buffalo species, and as a model for understanding human germ cell formation. Copyright © 2016 Elsevier Inc. All rights reserved.

Estimating rupture distances without a rupture

USGS Publications Warehouse

Thompson, Eric M.; Worden, Charles

2017-01-01

Most ground motion prediction equations (GMPEs) require distances that are defined relative to a rupture model, such as the distance to the surface projection of the rupture (RJB) or the closest distance to the rupture plane (RRUP). There are a number of situations in which GMPEs are used where it is either necessary or advantageous to derive rupture distances from point-source distance metrics, such as hypocentral (RHYP) or epicentral (REPI) distance. For ShakeMap, it is necessary to provide an estimate of the shaking levels for events without rupture models, and before rupture models are available for events that eventually do have rupture models. In probabilistic seismic hazard analysis, it is often convenient to use point-source distances for gridded seismicity sources, particularly if a preferred orientation is unknown. This avoids the computationally cumbersome task of computing rupture-based distances for virtual rupture planes across all strikes and dips for each source. We derive average rupture distances conditioned on REPI, magnitude, and (optionally) back azimuth, for a variety of assumed seismological constraints. Additionally, we derive adjustment factors for GMPE standard deviations that reflect the added uncertainty in the ground motion estimation when point-source distances are used to estimate rupture distances.

Analysis of 30 breast implant rupture cases.

PubMed

Tark, Kwan Chul; Jeong, Hii Sun; Roh, Tae Suk; Choi, Jong Woo

2005-01-01

Breast implants used for augmentation mammoplasty or breast reconstruction could rupture from various causes such as trauma or spontaneous failure. The objectives of this study were to investigate the relationships between the causes of implant rupture and the degree of capsular contracture, and then to evaluate the relative efficacies of specific signs on magnetic resonance imaging (MRI) known to be beneficial for diagnosing the rupture. A retrospective review identified patients with prosthetic implant rupture or impending rupture treated by the senior author. The 30 cases of implant rupture available for review were classified into two groups: intracapsular and extracapsular ruptures. The 30 cases of breast implant ruptures were analyzed with respect to the clinical symptoms and signs, the causes of rupture, the degree of capsular contracture, and therapeutic plans. Among the 30 cases, 14 patients who had undergone MRI during the diagnostic period were analyzed with respect to the relationships between MRI readings and operative findings. Spontaneous rupture of membranes was most common (80%), followed by failure because of trauma (7%) and valve or implant base (4%). The symptoms during implant rupture were contour deformity, palpated mass-like lesions, pain, and focal inflammation. According to the analysis of specific MRI signs, the sensitivity and specificity of the linguine sign were 87% and 100%, respectively, for intracapsular rupture. For extracapsular rupture, the sensitivity and specificity of the linguine sign were, respectively, 67% and 75%. The sensitivity and specificity of the rat-tail sign and tear drop sign were 14% and 50%, respectively. Breast implant rupture was correlated with the degree of capsular contracture in our study. Among the various specific MRI signs used in diagnosing the rupture, the linguine sign was reliable and had a high sensitivity and specificity, especially in cases of intracapsular rupture. On the other hand, the rat-tail and tear drop signs were nonspecific signs for diagnosing the rupture of breast implant.

Alliance ruptures and rupture resolution in cognitive-behavior therapy: a preliminary task analysis.

PubMed

Aspland, Helen; Llewelyn, Susan; Hardy, Gillian E; Barkham, Michael; Stiles, William

2008-11-01

An initial ideal, rational model of alliance rupture and rupture resolution provided by cognitive-behavioral therapy (CBT) experts was assessed and compared with empirical observations of ruptures and their resolution in two cases of successful CBT. The initial rational model emphasized nondefensive acknowledgment and exploration of the rupture. Results indicated differences between what therapists think they should do to resolve ruptures and what they actually do and suggested that the rational model should be expanded to emphasize client validation and empowerment. Therapists' ability to attend to ruptures emerged as an important clinical skill.

Rupture of the Pitáycachi Fault in the 1887 Mw 7.5 Sonora, Mexico earthquake (southern Basin-and-Range Province): Rupture kinematics and epicenter inferred from rupture branching patterns

NASA Astrophysics Data System (ADS)

Suter, Max

2015-01-01

During the 3 May 1887 Mw 7.5 Sonora earthquake (surface rupture end-to-end length: 101.8 km), an array of three north-south striking Basin-and-Range Province faults (from north to south Pitáycachi, Teras, and Otates) slipped sequentially along the western margin of the Sierra Madre Occidental Plateau. This detailed field survey of the 1887 earthquake rupture zone along the Pitáycachi fault includes mapping the rupture scarp and measurements of surface deformation. The surface rupture has an endpoint-to-endpoint length of ≥41.0 km, dips 70°W, and is characterized by normal left-lateral extension. The maximum surface offset is 487 cm and the mean offset 260 cm. The rupture trace shows a complex pattern of second-order segmentation. However, this segmentation is not expressed in the 1887 along-rupture surface offset profile, which indicates that the secondary segments are linked at depth into a single coherent fault surface. The Pitáycachi surface rupture shows a well-developed bipolar branching pattern suggesting that the rupture originated in its central part, where the polarity of the rupture bifurcations changes. Most likely the rupture first propagated bilaterally along the Pitáycachi fault. The southern rupture front likely jumped across a step over to the Teras fault and from there across a major relay zone to the Otates fault. Branching probably resulted from the lateral propagation of the rupture after breaching the seismogenic part of the crust, given that the much shorter ruptures of the Otates and Teras segments did not develop branches.

Maternal Factors Influencing Perinatal Transmission of HIV Infection

DTIC Science & Technology

1990-01-01

PET Chronic hypertension Eclampsia 17. IUGR 17. 18. Preterm Labor 18. 19. 3rd Trimester Bleeding 19. a) Placenta Previa b) Abruptio Placenta 20...Obstetrics/Gynecology, and laboratory procedures including those for maternal/neonatal drug screening and for handling and processing tissue ( placenta ...amniocentesis Is n done as a part of this study. After delivery, the placenta (afterbirth) will be examined for evidence of HIV infection (AIDS virus). Blood

A Retrospective Analysis of Ruptured Breast Implants

PubMed Central

Baek, Woo Yeol; Lew, Dae Hyun

2014-01-01

Background Rupture is an important complication of breast implants. Before cohesive gel silicone implants, rupture rates of both saline and silicone breast implants were over 10%. Through an analysis of ruptured implants, we can determine the various factors related to ruptured implants. Methods We performed a retrospective review of 72 implants that were removed for implant rupture between 2005 and 2014 at a single institution. The following data were collected: type of implants (saline or silicone), duration of implantation, type of implant shell, degree of capsular contracture, associated symptoms, cause of rupture, diagnostic tools, and management. Results Forty-five Saline implants and 27 silicone implants were used. Rupture was diagnosed at a mean of 5.6 and 12 years after insertion of saline and silicone implants, respectively. There was no association between shell type and risk of rupture. Spontaneous was the most common reason for the rupture. Rupture management was implant change (39 case), microfat graft (2 case), removal only (14 case), and follow-up loss (17 case). Conclusions Saline implants have a shorter average duration of rupture, but diagnosis is easier and safer, leading to fewer complications. Previous-generation silicone implants required frequent follow-up observation, and it is recommended that they be changed to a cohesive gel implant before hidden rupture occurs. PMID:25396188

Grey-scale and colour Doppler ultrasound versus magnetic resonance imaging for the prenatal diagnosis of placenta accreta.

PubMed

Rezk, Mohamed Abd-Allah; Shawky, Mohamed

2016-01-01

To assess the effectiveness of grey-scale and colour Doppler ultrasound (US) versus magnetic resonance imaging (MRI) for the prenatal diagnosis of placenta accreta. A prospective observational study including a total of 74 patients with placenta previa and previous uterine scar (n = 74). Grey-scale and colour Doppler US was done followed by MRI by different observers to diagnose adherent placenta. Test validity of US and MRI were calculated. Maternal morbidity and mortality were also assessed. A total of 53 patients confirmed to have placenta accreta at operation. The overall sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of US was 94.34, 91.67, 96.15 and 88% compared to 96.08, 87.50, 94.23 and 91.3% for MRI, respectively. The most relevant US sign was turbulent blood flow by colour Doppler, while dark intra-placental band was the most sensitive MRI sign. Venous thromboembolism (1.3%), bladder injury (29.7%), ureteric injury (18.9%), postoperative fever (10.8%), admission to ICU (50%) and re-operation (31.1%). Placenta accreta can be successfully diagnosed by grey-scale and colour Doppler US. MRI would be more likely suggested for either posteriorly or laterally situated placenta previa in order to exclude placental invasion.

Rupture directivity of moderate earthquakes in northern California

USGS Publications Warehouse

Seekins, Linda C.; Boatwright, John

2010-01-01

We invert peak ground velocity and acceleration (PGV and PGA) to estimate rupture direction and rupture velocity for 47 moderate earthquakes (3.5≥M≥5.4) in northern California. We correct sets of PGAs and PGVs recorded at stations less than 55–125 km, depending on source depth, for site amplification and source–receiver distance, then fit the residual peak motions to the unilateral directivity function of Ben-Menahem (1961). We independently invert PGA and PGV. The rupture direction can be determined using as few as seven peak motions if the station distribution is sufficient. The rupture velocity is unstable, however, if there are no takeoff angles within 30° of the rupture direction. Rupture velocities are generally subsonic (0.5β–0.9β); for stability, we limit the rupture velocity at v=0.92β, the Rayleigh wave speed. For 73 of 94 inversions, the rupture direction clearly identifies one of the nodal planes as the fault plane. The 35 strike-slip earthquakes have rupture directions that range from nearly horizontal (6 events) to directly updip (5 events); the other 24 rupture partly along strike and partly updip. Two strike-slip earthquakes rupture updip in one inversion and downdip in the other. All but 1 of the 11 thrust earthquakes rupture predominantly updip. We compare the rupture directions for 10 M≥4.0 earthquakes to the relative location of the mainshock and the first two weeks of aftershocks. Spatial distributions of 8 of 10 aftershock sequences agree well with the rupture directivity calculated for the mainshock.

An insight on correlations between kinematic rupture parameters from dynamic ruptures on rough faults

NASA Astrophysics Data System (ADS)

Thingbijam, Kiran Kumar; Galis, Martin; Vyas, Jagdish; Mai, P. Martin

2017-04-01

We examine the spatial interdependence between kinematic parameters of earthquake rupture, which include slip, rise-time (total duration of slip), acceleration time (time-to-peak slip velocity), peak slip velocity, and rupture velocity. These parameters were inferred from dynamic rupture models obtained by simulating spontaneous rupture on faults with varying degree of surface-roughness. We observe that the correlations between these parameters are better described by non-linear correlations (that is, on logarithm-logarithm scale) than by linear correlations. Slip and rise-time are positively correlated while these two parameters do not correlate with acceleration time, peak slip velocity, and rupture velocity. On the other hand, peak slip velocity correlates positively with rupture velocity but negatively with acceleration time. Acceleration time correlates negatively with rupture velocity. However, the observed correlations could be due to weak heterogeneity of the slip distributions given by the dynamic models. Therefore, the observed correlations may apply only to those parts of rupture plane with weak slip heterogeneity if earthquake-rupture associate highly heterogeneous slip distributions. Our findings will help to improve pseudo-dynamic rupture generators for efficient broadband ground-motion simulations for seismic hazard studies.

Rupture process of the 2013 Okhotsk deep mega earthquake from iterative backprojection and compress sensing methods

NASA Astrophysics Data System (ADS)

Qin, W.; Yin, J.; Yao, H.

2013-12-01

On May 24th 2013 a Mw 8.3 normal faulting earthquake occurred at a depth of approximately 600 km beneath the sea of Okhotsk, Russia. It is a rare mega earthquake that ever occurred at such a great depth. We use the time-domain iterative backprojection (IBP) method [1] and also the frequency-domain compressive sensing (CS) technique[2] to investigate the rupture process and energy radiation of this mega earthquake. We currently use the teleseismic P-wave data from about 350 stations of USArray. IBP is an improved method of the traditional backprojection method, which more accurately locates subevents (energy burst) during earthquake rupture and determines the rupture speeds. The total rupture duration of this earthquake is about 35 s with a nearly N-S rupture direction. We find that the rupture is bilateral in the beginning 15 seconds with slow rupture speeds: about 2.5km/s for the northward rupture and about 2 km/s for the southward rupture. After that, the northward rupture stopped while the rupture towards south continued. The average southward rupture speed between 20-35 s is approximately 5 km/s, lower than the shear wave speed (about 5.5 km/s) at the hypocenter depth. The total rupture length is about 140km, in a nearly N-S direction, with a southward rupture length about 100 km and a northward rupture length about 40 km. We also use the CS method, a sparse source inversion technique, to study the frequency-dependent seismic radiation of this mega earthquake. We observe clear along-strike frequency dependence of the spatial and temporal distribution of seismic radiation and rupture process. The results from both methods are generally similar. In the next step, we'll use data from dense arrays in southwest China and also global stations for further analysis in order to more comprehensively study the rupture process of this deep mega earthquake. Reference [1] Yao H, Shearer P M, Gerstoft P. Subevent location and rupture imaging using iterative backprojection for the 2011 Tohoku Mw 9.0 earthquake. Geophysical Journal International, 2012, 190(2): 1152-1168. [2]Yao H, Gerstoft P, Shearer P M, et al. Compressive sensing of the Tohoku-Oki Mw 9.0 earthquake: Frequency-dependent rupture modes. Geophysical Research Letters, 2011, 38(20).

Persistent rupture terminations at a restraining bend from slip rates on the eastern Altyn Tagh fault

NASA Astrophysics Data System (ADS)

Elliott, A. J.; Oskin, M. E.; Liu-zeng, J.; Shao, Y.-X.

2018-05-01

Restraining double-bends along strike-slip faults inhibit or permit throughgoing ruptures depending on bend angle, length, and prior rupture history. Modeling predicts that for mature strike-slip faults in a regional stress regime characterized by simple shear, a restraining bend of >18° and >4 km length impedes propagating rupture. Indeed, natural evidence shows that the most recent rupture(s) of the Xorkoli section (90°-93°E) of the eastern Altyn Tagh fault (ATF) ended at large restraining bends. However, when multiple seismic cycles are considered in numerical dynamic rupture modeling, heterogeneous residual stresses enable some ruptures to propagate further, modulating whether the bends persistently serve as barriers. These models remain to be tested using observations of the cumulative effects of multiple earthquake ruptures. Here we investigate whether a large restraining double-bend on the ATF serves consistently as a barrier to rupture by measuring long-term slip rates around the terminus of its most recent surface rupture at the Aksay bend. Our results show a W-E decline in slip as the SATF enters the bend, as would be predicted from repeated rupture terminations there. Prior work demonstrated no Holocene slip on the central, most misoriented portion of the bend, while 19-79 m offsets suggest that multiple ruptures have occurred on the west side of the bend during the Holocene. Thus we conclude the gradient in the SATF's slip rate results from the repeated termination of earthquake ruptures there. However, a finite slip rate east of the bend represents the transmission of some slip, suggesting that a small fraction of ruptures may fully traverse or jump the double-bend. This agreement between natural observations of slip accumulation and multi-cycle models of fault rupture enables us to translate observed slip rates into insight about the dynamic rupture process of individual earthquakes as they encounter geometric complexities along faults.

Risks of adverse outcomes in the next birth after a first cesarean delivery.

PubMed

Kennare, Robyn; Tucker, Graeme; Heard, Adrian; Chan, Annabelle

2007-02-01

To estimate the risks of cesarean first birth, compared with vaginal first birth, for adverse obstetric and perinatal outcomes in the second birth. Population-based retrospective cohort study of all singleton, second births in the South Australian perinatal data collection 1998 to 2003 comparing outcomes for 8,725 women who underwent a cesarean delivery for their first birth with 27,313 women who underwent a vaginal first birth. Predictor variables include age, indigenous status, smoking, pregnancy interval, medical and obstetric complications, gestation, patient type, hospital category, and history of ectopic pregnancy, miscarriage, stillbirth or termination of pregnancy. The cesarean delivery cohort had increased risks for malpresentation (odds ratio [OR] 1.84, 95% confidence interval [CI] 1.65-2.06), placenta previa (OR 1.66, 95% CI 1.30-2.11), antepartum hemorrhage (OR 1.23, 95% CI 1.08-1.41), placenta accreta (OR 18.79, 95% CI 2.28-864.6), prolonged labor (OR 5.89, 95% CI 3.91-8.89), emergency cesarean (relative risk 9.37, 95% CI 8.98-9.76) and uterine rupture (OR 84.42, 95% CI 14.64-infinity), preterm birth (OR 1.17, 95% CI 1.04-1.31), low birth weight (OR 1.30, 95% CI 1.14-1.48), small for gestational age (OR 1.12, 95% CI 1.02-1.23), stillbirth (OR 1.56, 95% CI 1.04-2.32), and unexplained stillbirth (OR 2.34, 95% CI 1.26-4.37). The range of the number of primary cesarean deliveries needed to harm included 134 for one additional preterm birth, up to 1,536 for one additional placenta accreta. Cesarean delivery is associated with increased risks for adverse obstetric and perinatal outcomes in the subsequent birth. However, some risks may be due to confounding factors related to the indication for the first cesarean. II.

Endometriosis increases the risk of obstetrical and neonatal complications.

PubMed

Berlac, Janne Foss; Hartwell, Dorthe; Skovlund, Charlotte Wessel; Langhoff-Roos, Jens; Lidegaard, Øjvind

2017-06-01

The objective of this study was to assess obstetrical complications and neonatal outcomes in women with endometriosis as compared with women without endometriosis. National cohort including all delivering women and their newborns in Denmark 1997-2014. Data were extracted from the Danish Health Register and the Medical Birth Register. Logistic regression analysis provided odds ratios (OR) with 95% confidence intervals (CI). Sub-analyses were made for primiparous women with a singleton pregnancy and for women with endometriosis who underwent gynecological surgery before pregnancy. In 19 331 deliveries, women with endometriosis had a higher risk of severe preeclampsia (OR 1.7, 95% CI 1.5-2.0), hemorrhage in pregnancy (OR 2.3, 95% CI 2.0-2.5), placental abruption (OR 2.0, 95% CI 1.7-2.3), placenta previa (OR 3.9, 95% CI 3.5-4.3), premature rupture of membranes (OR 1.7, 95% CI 1.5-1.8), and retained placenta (OR 3.1, 95% CI 1.4-6.6). The neonates had increased risks of preterm birth before 28 weeks (OR 3.1, 95% CI 2.7-3.6), being small for gestational age (OR 1.5, 95% CI 1.4-1.6), being diagnosed with congenital malformations (OR 1.3, 95% CI 1.3-1.4), and neonatal death (OR 1.8, 95% CI 1.4-2.1). Results were similar in primiparous women with a singleton pregnancy. Gynecological surgery for endometriosis before pregnancy carried a further increased risk. Women with endometriosis had a significantly higher risk of several complications, such as preeclampsia and placental complications in pregnancy and at delivery. The newborns had increased risk of being delivered preterm, having congenital malformations, and having a higher neonatal death rate. Pregnant women with endometriosis require increased antenatal surveillance. © 2017 Nordic Federation of Societies of Obstetrics and Gynecology.

Germ cell specification and ovary structure in the rotifer Brachionus plicatilis

PubMed Central

2010-01-01

Background The segregation of the germline from somatic tissues is an essential process in the development of all animals. Specification of the primordial germ cells (PGCs) takes place via different strategies across animal phyla; either specified early in embryogenesis by the inheritance of maternal determinants in the cytoplasm of the oocyte ('preformation') or selected later in embryonic development from undifferentiated precursors by a localized inductive signal ('epigenesis'). Here we investigate the specification and development of the germ cells in the rotifer Brachionus plicatilis, a member of the poorly-characterized superphyla Lophotrochozoa, by isolating the Brachionus homologues of the conserved germ cell markers vasa and nanos, and examining their expression using in situ hybridization. Results Bpvasa and Bpnos RNA expression have very similar distributions in the Brachionus ovary, showing ubiquitous expression in the vitellarium, with higher levels in the putative germ cell cluster. Bpvas RNA expression is present in freshly laid eggs, remaining ubiquitous in embryos until at least the 96 cell stage after which expression narrows to a small cluster of cells at the putative posterior of the embryo, consistent with the developing ovary. Bpnos RNA expression is also present in just-laid eggs but expression is much reduced by the four-cell stage and absent by the 16-cell stage. Shortly before hatching of the juvenile rotifer from the egg, Bpnos RNA expression is re-activated, located in a subset of posterior cells similar to those expressing Bpvas at the same stage. Conclusions The observed expression of vasa and nanos in the developing B. plicatilis embryo implies an epigenetic origin of primordial germ cells in Rotifer. PMID:20849649

Fine structure of the male reproductive system and reproductive behavior of Lutzomyia longipalpis sandflies (Diptera: Psychodidae: Phlebotominae).

PubMed

Spiegel, Carolina N; Bretas, Jorge A C; Peixoto, Alexandre A; Vigoder, Felipe M; Bruno, Rafaela V; Soares, Maurilio J

2013-01-01

The male reproductive system of insects can have several tissues responsible for the secretion of seminal fluid proteins (SFPs), such as testes, accessory glands, seminal vesicles, ejaculatory duct and ejaculatory bulb. The SFPs are transferred during mating and can induce several physiological and behavioral changes in females, such as increase in oviposition and decrease in sexual receptivity after copulation. The phlebotomine Lutzomyia longipalpis is the main vector of visceral leishmaniasis. Despite its medical importance, little is known about its reproductive biology. Here we present morphological aspects of the male L. longipalpis reproductive system by light, scanning and transmission electron microscopy, and compare the mating frequency of both virgin and previously mated females. The male L. longipalpis reproductive system is comprised by a pair of oval-shaped testes linked to a seminal vesicle by vasa deferentia. It follows an ejaculatory duct with an ejaculatory pump (a large bulb enveloped by muscles and associated to tracheas). The terminal endings of the vasa deferentia are inserted into the seminal vesicle by invaginations of the seminal vesicle wall, which is composed by a single layer of gland cells, with well-developed endoplasmic reticulum profiles and secretion granules. Our data suggest that the seminal vesicle acts both as a spermatozoa reservoir and as an accessory gland. Mating experiments support this hypothesis, revealing a decrease in mating frequency after copulation that indicates the effect of putative SFPs. Ultrastructural features of the L. longipalpis male seminal vesicle indicated its possible role as an accessory gland. Behavioral observations revealed a reduction in mating frequency of copulated females. Together with transcriptome analyses from male sandfly reproductive organs identifying ESTs encoding orthologs of SFPs, these data indicate the presence of putative L. longipalpis SFPs reducing sexual mating frequency of copulated females.

Zebrafish embryos as a screen for DNA methylation modifications after compound exposure.

PubMed

Bouwmeester, Manon C; Ruiter, Sander; Lommelaars, Tobias; Sippel, Josefine; Hodemaekers, Hennie M; van den Brandhof, Evert-Jan; Pennings, Jeroen L A; Kamstra, Jorke H; Jelinek, Jaroslav; Issa, Jean-Pierre J; Legler, Juliette; van der Ven, Leo T M

2016-01-15

Modified epigenetic programming early in life is proposed to underlie the development of an adverse adult phenotype, known as the Developmental Origins of Health and Disease (DOHaD) concept. Several environmental contaminants have been implicated as modifying factors of the developing epigenome. This underlines the need to investigate this newly recognized toxicological risk and systematically screen for the epigenome modifying potential of compounds. In this study, we examined the applicability of the zebrafish embryo as a screening model for DNA methylation modifications. Embryos were exposed from 0 to 72 h post fertilization (hpf) to bisphenol-A (BPA), diethylstilbestrol, 17α-ethynylestradiol, nickel, cadmium, tributyltin, arsenite, perfluoroctanoic acid, valproic acid, flusilazole, 5-azacytidine (5AC) in subtoxic concentrations. Both global and site-specific methylation was examined. Global methylation was only affected by 5AC. Genome wide locus-specific analysis was performed for BPA exposed embryos using Digital Restriction Enzyme Analysis of Methylation (DREAM), which showed minimal wide scale effects on the genome, whereas potential informative markers were not confirmed by pyrosequencing. Site-specific methylation was examined in the promoter regions of three selected genes vasa, vtg1 and cyp19a2, of which vasa (ddx4) was the most responsive. This analysis distinguished estrogenic compounds from metals by direction and sensitivity of the effect compared to embryotoxicity. In conclusion, the zebrafish embryo is a potential screening tool to examine DNA methylation modifications after xenobiotic exposure. The next step is to examine the adult phenotype of exposed embryos and to analyze molecular mechanisms that potentially link epigenetic effects and altered phenotypes, to support the DOHaD hypothesis. Copyright © 2015 Elsevier Inc. All rights reserved.

Glial cell line-derived neurotrophic factor in combination with insulin-like growth factor 1 and basic fibroblast growth factor promote in vitro culture of goat spermatogonial stem cells.

PubMed

Bahadorani, M; Hosseini, S M; Abedi, P; Abbasi, H; Nasr-Esfahani, M H

2015-01-01

Growth factors are increasingly considered as important regulators of spermatogonial stem cells (SSCs). This study investigated the effects of various growth factors (GDNF, IGF1, bFGF, EGF and GFRalpha-1) on purification and colonization of undifferentiated goat SSCs under in vitro and in vivo conditions. Irrespective of the culture condition used, the first signs of developing colonies were observed from day 4 of culture onwards. The number of colonies developed in GDNF + IGF1 + bFGF culture condition was significantly higher than the other groups (p < 0.05). In contrast, the size of colonies developed in GDNF + EGF + LIF culture condition was significantly higher than the other groups (p < 0.05). Immunocytochemical stationing for specific biomarkers of somatic cells (vimentin, alpha-inhibin and α-SMA) and spermatogonial cells (PLZF, THY 1, VASA, alpha-1 integrin, bet-1 integrin and DBA) revealed that both cell types existed in developing colonies, irrespective of the culture condition used. Even though, the relative abundance of VASA, FGFR3, OCT4, PLZF, BCL6B and THY1 transcription factors in GDNF + IGF1 + bFGF treatment group was significantly higher than the other groups (p < 0.05). Additionally, goat SSCs developed in the latter culture condition could colonize within the seminiferous tubules of the germ-cell depleted recipient mice following xenotransplantation. Obtained results demonstrated that combination of GDNF with IGF1 and bFGF promote in vitro culture of goat SSCs while precludes uncontrolled proliferation of somatic cells.

Music intervention during daily weaning trials-A 6 day prospective randomized crossover trial.

PubMed

Liang, Zhan; Ren, Dianxu; Choi, JiYeon; Happ, Mary Beth; Hravnak, Marylyn; Hoffman, Leslie A

2016-12-01

To examine the effect of patient-selected music intervention during daily weaning trials for patients on prolonged mechanical ventilation. Using a crossover repeated measures design, patients were randomized to music vs no music on the first intervention day. Provision of music was alternated for 6 days, resulting in 3 music and 3 no music days. During weaning trials on music days, data were obtained for 30min prior to music listening and continued for 60min while patients listened to selected music (total 90min). On no music days, data were collected for 90min. Outcome measures were heart rate (HR), respiratory rate (RR), oxygen saturation (SpO 2 ), blood pressure (BP), dyspnea and anxiety assessed with a visual analog scale (VAS-D, VAS-A) and weaning duration (meanh per day on music and non-music days). Of 31 patients randomized, 23 completed the 6-day intervention. When comparisons were made between the 3 music and 3 no music days, there were significant decreases in RR and VAS-D and a significant increase in daily weaning duration on music days (p<0.05). A multivariate mixed-effects model analysis that included patients who completed ≥2 days of the intervention (n=28) demonstrated significant decreases in HR, RR, VAS-A, and VAS-D and a significant increase in daily weaning duration on music days (p<0.05). Providing patient selected music during daily weaning trials is a simple, low-cost, potentially beneficial intervention for patients on prolonged mechanical ventilation. Further study is indicated to test ability of this intervention to promote weaning success and benefits earlier in the weaning process. Copyright © 2016 Elsevier Ltd. All rights reserved.

Axial compartmentation of descending and ascending thin limbs of Henle's loops

PubMed Central

Westrick, Kristen Y.; Serack, Bradley; Dantzler, William H.

2013-01-01

In the inner medulla, radial organization of nephrons and blood vessels around collecting duct (CD) clusters leads to two lateral interstitial regions and preferential intersegmental fluid and solute flows. As the descending (DTLs) and ascending thin limbs (ATLs) pass through these regions, their transepithelial fluid and solute flows are influenced by variable transepithelial solute gradients and structure-to-structure interactions. The goal of this study was to quantify structure-to-structure interactions, so as to better understand compartmentation and flows of transepithelial water, NaCl, and urea and generation of the axial osmotic gradient. To accomplish this, we determined lateral distances of AQP1-positive and AQP1-negative DTLs and ATLs from their nearest CDs, so as to gauge interactions with intercluster and intracluster lateral regions and interactions with interstitial nodal spaces (INSs). DTLs express reduced AQP1 and low transepithelial water permeability along their deepest segments. Deep AQP1-null segments, prebend segments, and ATLs lie equally near to CDs. Prebend segments and ATLs abut CDs and INSs throughout much of their descent and ascent, respectively; however, the distal 30% of ATLs of the longest loops lie distant from CDs as they approach the outer medullary boundary and have minimal interaction with INSs. These relationships occur regardless of loop length. Finally, we show that ascending vasa recta separate intercluster AQP1-positive DTLs from descending vasa recta, thereby minimizing dilution of gradients that drive solute secretion. We hypothesize that DTLs and ATLs enter and exit CD clusters in an orchestrated fashion that is important for generation of the corticopapillary solute gradient by minimizing NaCl and urea loss. PMID:23195680

Axial compartmentation of descending and ascending thin limbs of Henle's loops.

PubMed

Westrick, Kristen Y; Serack, Bradley; Dantzler, William H; Pannabecker, Thomas L

2013-02-01

In the inner medulla, radial organization of nephrons and blood vessels around collecting duct (CD) clusters leads to two lateral interstitial regions and preferential intersegmental fluid and solute flows. As the descending (DTLs) and ascending thin limbs (ATLs) pass through these regions, their transepithelial fluid and solute flows are influenced by variable transepithelial solute gradients and structure-to-structure interactions. The goal of this study was to quantify structure-to-structure interactions, so as to better understand compartmentation and flows of transepithelial water, NaCl, and urea and generation of the axial osmotic gradient. To accomplish this, we determined lateral distances of AQP1-positive and AQP1-negative DTLs and ATLs from their nearest CDs, so as to gauge interactions with intercluster and intracluster lateral regions and interactions with interstitial nodal spaces (INSs). DTLs express reduced AQP1 and low transepithelial water permeability along their deepest segments. Deep AQP1-null segments, prebend segments, and ATLs lie equally near to CDs. Prebend segments and ATLs abut CDs and INSs throughout much of their descent and ascent, respectively; however, the distal 30% of ATLs of the longest loops lie distant from CDs as they approach the outer medullary boundary and have minimal interaction with INSs. These relationships occur regardless of loop length. Finally, we show that ascending vasa recta separate intercluster AQP1-positive DTLs from descending vasa recta, thereby minimizing dilution of gradients that drive solute secretion. We hypothesize that DTLs and ATLs enter and exit CD clusters in an orchestrated fashion that is important for generation of the corticopapillary solute gradient by minimizing NaCl and urea loss.

Effect of sodium chloride gradients on water flux in rat descending vasa recta.

PubMed

Pallone, T L

1991-01-01

In the hydropenic kidney, volume efflux from descending vasa recta (DVR) occurs despite an intracapillary oncotic pressure that exceeds hydraulic pressure. That finding has been attributed to small solute gradients which may provide an additional osmotic driving force favoring water transport from DVR plasma to the papillary interstitium. To test this hypothesis, axial gradients of NaCl and urea in the papilla were eliminated by administration of furosemide and saline. DVR were then blocked with paraffin and microperfused at 10 nl/min with a buffer containing albumin, fluorescein isothiocyanate labeled dextran (FITC-Dx), 22Na, and NaCl in a concentration of 0 (hypotonic to the interstitium), 161 (isotonic) or 322 mM (hypertonic). Collectate was obtained from the perfused DVR by micropuncture and the collectate-to-perfusate ratios of FITC-Dx and 22Na were measured. A mathematical model was employed to determine DVR permeability (Ps) and reflection coefficient to NaCl (sigma NaCl). The rate of transport of water from the DVR lumen to the papillary interstitium was 2.8 +/- 0.3 (Nv = 22), -0.19 +/- 0.4 (Nv = 15), and -2.3 +/- 0.3 nl/min (Nv = 21) (mean +/- SE) when perfusate NaCl was 0, 161, or 322 mM, respectively (Nv = number of DVR perfused). The collectate-to-perfusate 22Na concentration ratios were 0.34 +/- 0.04, 0.36 +/- 0.04 and 0.37 +/- 0.03 for those groups, respectively. Based on these data, Ps is calculated to be 60.4 x 10(-5) +/- 4.0 x 10(-5) cm/s and sigma NaCl less than 0.05. The results of this study confirm that transcapillary NaCl concentrations gradients induce water movement across the wall of the DVR.

Architecture of the human renal inner medulla and functional implications.

PubMed

Wei, Guojun; Rosen, Seymour; Dantzler, William H; Pannabecker, Thomas L

2015-10-01

The architecture of the inner stripe of the outer medulla of the human kidney has long been known to exhibit distinctive configurations; however, inner medullary architecture remains poorly defined. Using immunohistochemistry with segment-specific antibodies for membrane fluid and solute transporters and other proteins, we identified a number of distinctive functional features of human inner medulla. In the outer inner medulla, aquaporin-1 (AQP1)-positive long-loop descending thin limbs (DTLs) lie alongside descending and ascending vasa recta (DVR, AVR) within vascular bundles. These vascular bundles are continuations of outer medullary vascular bundles. Bundles containing DTLs and vasa recta lie at the margins of coalescing collecting duct (CD) clusters, thereby forming two regions, the vascular bundle region and the CD cluster region. Although AQP1 and urea transporter UT-B are abundantly expressed in long-loop DTLs and DVR, respectively, their expression declines with depth below the outer medulla. Transcellular water and urea fluxes likely decline in these segments at progressively deeper levels. Smooth muscle myosin heavy chain protein is also expressed in DVR of the inner stripe and the upper inner medulla, but is sparsely expressed at deeper inner medullary levels. In rodent inner medulla, fenestrated capillaries abut CDs along their entire length, paralleling ascending thin limbs (ATLs), forming distinct compartments (interstitial nodal spaces; INSs); however, in humans this architecture rarely occurs. Thus INSs are relatively infrequent in the human inner medulla, unlike in the rodent where they are abundant. UT-B is expressed within the papillary epithelium of the lower inner medulla, indicating a transcellular pathway for urea across this epithelium. Copyright © 2015 the American Physiological Society.

Postjunctional inhibition of contractor responses in the mouse vas deferens by rat and human calcitonin gene-related peptides (CGRP).

PubMed Central

Al-Kazwini, S. J.; Craig, R. K.; Marshall, I.

1986-01-01

The effects of rat and human alpha-calcitonin gene-related peptide (CGRP) were compared in the mouse and rabbit isolated vas deferens preparation contracted by either field stimulation or acetylcholine. The peptides were about equipotent at inhibiting twitch responses of the mouse vas deferens to field stimulation at 0.2 Hz (IC50 12 +/- 4 nM and 15 +/- 3 nM, rat and human alpha-CGRP respectively). Rat alpha-CGRP was less potent at inhibiting responses to 10 Hz than to either 0.2 Hz or 1.0 Hz stimulation. The potency of rat alpha-CGRP at 1.0 Hz was unaltered by halving the calcium concentration of the Krebs solution. The inhibitory effect of human alpha-CGRP was not antagonized by either propranolol (300 nM) or idazoxan (300 nM), although in the same tissues these latter two drugs reduced responses to isoprenaline and clonidine respectively. Rat alpha-CGRP (100 nM) and human alpha-CGRP (1.0 microM) did not alter the uptake of [3H]-noradrenaline (30 nM) into mice isolated vasa deferentia. Rat alpha-CGRP (3-100 nM) did not alter the fractional release per pulse (1.0 Hz, 100 pulses) of tritium from vasa preloaded with [3H]-noradrenaline, although at the same time the peptide inhibited responses of the smooth muscle to field stimulation. Rat and human alpha-CGRP were equipotent at inhibiting contractions of the mouse vas deferens evoked by acetylcholine although the peptides were less potent than against twitch responses. In the rabbit vas deferens neither rat nor human alpha-CGRP (3 nM-1 microM) inhibited either twitch responses or acetylcholine contractions.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3486688

High salt induces autocrine actions of ET-1 on inner medullary collecting duct NO production via upregulated ETB receptor expression.

PubMed

Hyndman, Kelly Anne; Dugas, Courtney; Arguello, Alexandra M; Goodchild, Traci T; Buckley, Kathleen M; Burch, Mariah; Yanagisawa, Masashi; Pollock, Jennifer S

2016-08-01

The collecting duct endothelin-1 (ET-1), endothelin B (ETB) receptor, and nitric oxide synthase-1 (NOS1) pathways are critical for regulation of fluid-electrolyte balance and blood pressure control during high-salt feeding. ET-1, ETB receptor, and NOS1 are highly expressed in the inner medullary collecting duct (IMCD) and vasa recta, suggesting that there may be cross talk or paracrine signaling between the vasa recta and IMCD. The purpose of this study was to test the hypothesis that endothelial cell-derived ET-1 (paracrine) and collecting duct-derived ET-1 (autocrine) promote IMCD nitric oxide (NO) production through activation of the ETB receptor during high-salt feeding. We determined that after 7 days of a high-salt diet (HS7), there was a shift to 100% ETB expression in IMCDs, as well as a twofold increase in nitrite production (a metabolite of NO), and this increase could be prevented by acute inhibition of the ETB receptor. ETB receptor blockade or NOS1 inhibition also prevented the ET-1-dependent decrease in ion transport from primary IMCDs, as determined by transepithelial resistance. IMCD were also isolated from vascular endothelial ET-1 knockout mice (VEETKO), collecting duct ET-1 KO (CDET-1KO), and flox controls. Nitrite production by IMCD from VEETKO and flox mice was similarly increased twofold with HS7. However, IMCD NO production from CDET-1KO mice was significantly blunted with HS7 compared with flox control. Taken together, these data indicate that during high-salt feeding, the autocrine actions of ET-1 via upregulation of the ETB receptor are critical for IMCD NO production, facilitating inhibition of ion reabsorption. Copyright © 2016 the American Physiological Society.

Fault Branching and Long-Term Earthquake Rupture Scenario for Strike-Slip Earthquake

NASA Astrophysics Data System (ADS)

Klinger, Y.; CHOI, J. H.; Vallage, A.

2017-12-01

Careful examination of surface rupture for large continental strike-slip earthquakes reveals that for the majority of earthquakes, at least one major branch is involved in the rupture pattern. Often, branching might be either related to the location of the epicenter or located toward the end of the rupture, and possibly related to the stopping of the rupture. In this work, we examine large continental earthquakes that show significant branches at different scales and for which ground surface rupture has been mapped in great details. In each case, rupture conditions are described, including dynamic parameters, past earthquakes history, and regional stress orientation, to see if the dynamic stress field would a priori favor branching. In one case we show that rupture propagation and branching are directly impacted by preexisting geological structures. These structures serve as pathways for the rupture attempting to propagate out of its shear plane. At larger scale, we show that in some cases, rupturing a branch might be systematic, hampering possibilities for the development of a larger seismic rupture. Long-term geomorphology hints at the existence of a strong asperity in the zone where the rupture branched off the main fault. There, no evidence of throughgoing rupture could be seen along the main fault, while the branch is well connected to the main fault. This set of observations suggests that for specific configurations, some rupture scenarios involving systematic branching are more likely than others.

Ground motion hazard from supershear rupture

USGS Publications Warehouse

Andrews, D.J.

2010-01-01

An idealized rupture, propagating smoothly near a terminal rupture velocity, radiates energy that is focused into a beam. For rupture velocity less than the S-wave speed, radiated energy is concentrated in a beam of intense fault-normal velocity near the projection of the rupture trace. Although confined to a narrow range of azimuths, this beam diverges and attenuates. For rupture velocity greater than the S-wave speed, radiated energy is concentrated in Mach waves forming a pair of beams propagating obliquely away from the fault. These beams do not attenuate until diffraction becomes effective at large distance. Events with supershear and sub-Rayleigh rupture velocity are compared in 2D plane-strain calculations with equal stress drop, fracture energy, and rupture length; only static friction is changed to determine the rupture velocity. Peak velocity in the sub-Rayleigh case near the termination of rupture is larger than peak velocity in the Mach wave in the supershear case. The occurrence of supershear rupture propagation reduces the most intense peak ground velocity near the fault, but it increases peak velocity within a beam at greater distances.

Module isolation devices

DOEpatents

Carolan, Michael Francis; Cooke, John Albert; Buzinski, Michael David

2010-04-27

A gas flow isolation device includes a gas flow isolation valve movable from an opened condition to a closed condition. The module isolation valve in one embodiment includes a rupture disk in flow communication with a flow of gas when the module isolation valve is in an opened condition. The rupture disk ruptures when a predetermined pressure differential occurs across it causing the isolation valve to close. In one embodiment the valve is mechanically linked to the rupture disk to maintain the valve in an opened condition when the rupture disk is intact, and which permits the valve to move into a closed condition when the rupture disk ruptures. In another embodiment a crushable member maintains the valve in an open condition, and the flow of gas passed the valve upon rupturing of the rupture disk compresses the crushable member to close the isolation valve.

Slow rupture of frictional interfaces

NASA Astrophysics Data System (ADS)

Bar Sinai, Yohai; Brener, Efim A.; Bouchbinder, Eran

2012-02-01

The failure of frictional interfaces and the spatiotemporal structures that accompany it are central to a wide range of geophysical, physical and engineering systems. Recent geophysical and laboratory observations indicated that interfacial failure can be mediated by slow slip rupture phenomena which are distinct from ordinary, earthquake-like, fast rupture. These discoveries have influenced the way we think about frictional motion, yet the nature and properties of slow rupture are not completely understood. We show that slow rupture is an intrinsic and robust property of simple non-monotonic rate-and-state friction laws. It is associated with a new velocity scale cmin, determined by the friction law, below which steady state rupture cannot propagate. We further show that rupture can occur in a continuum of states, spanning a wide range of velocities from cmin to elastic wave-speeds, and predict different properties for slow rupture and ordinary fast rupture. Our results are qualitatively consistent with recent high-resolution laboratory experiments and may provide a theoretical framework for understanding slow rupture phenomena along frictional interfaces.

The influence of atmospheric pressure on aortic aneurysm rupture--is the diameter of the aneurysm important?

PubMed

Urbanek, Tomasz; Juśko, Maciej; Niewiem, Alfred; Kuczmik, Wacław; Ziaja, Damian; Ziaja, Krzysztof

2015-01-01

The rate of aortic aneurysm rupture correlates with the aneurysm's diameter, and a higher rate of rupture is observed in patients with larger aneurysms. According to the literature, contradictory results concerning the relationship between atmospheric pressure and aneurysm size have been reported. In this paper, we assessed the influence of changes in atmospheric pressure on abdominal aneurysm ruptures in relationship to the aneurysm's size. The records of 223 patients with ruptured abdominal aneurysms were evaluated. All of the patients had been admitted to the department in the period 1997-2007 from the Silesia region. The atmospheric pressures on the day of the rupture and on the days both before the rupture and between the rupture events were compared. The size of the aneurysm was also considered in the analysis. There were no statistically significant differences in pressure between the days of rupture and the remainder of the days within an analysed period. The highest frequency of the admission of patients with a ruptured aortic aneurysm was observed during periods of winter and spring, when the highest mean values of atmospheric pressure were observed; however, this observation was not statistically confirmed. A statistically non-significant trend towards the higher rupture of large aneurysms (> 7 cm) was observed in the cases where the pressure increased between the day before the rupture and the day of the rupture. This trend was particularly pronounced in patients suffering from hypertension (p = 0.1). The results of this study do not support the hypothesis that there is a direct link between atmospheric pressure values and abdominal aortic aneurysm ruptures.

Spatiotemporal complexity of 2-D rupture nucleation process observed by direct monitoring during large-scale biaxial rock friction experiments

NASA Astrophysics Data System (ADS)

Fukuyama, Eiichi; Tsuchida, Kotoyo; Kawakata, Hironori; Yamashita, Futoshi; Mizoguchi, Kazuo; Xu, Shiqing

2018-05-01

We were able to successfully capture rupture nucleation processes on a 2-D fault surface during large-scale biaxial friction experiments using metagabbro rock specimens. Several rupture nucleation patterns have been detected by a strain gauge array embedded inside the rock specimens as well as by that installed along the edge walls of the fault. In most cases, the unstable rupture started just after the rupture front touched both ends of the rock specimen (i.e., when rupture front extended to the entire width of the fault). In some cases, rupture initiated at multiple locations and the rupture fronts coalesced to generate unstable ruptures, which could only be detected from the observation inside the rock specimen. Therefore, we need to carefully examine the 2-D nucleation process of the rupture especially when analyzing the data measured only outside the rock specimen. At least the measurements should be done at both sides of the fault to identify the asymmetric rupture propagation on the fault surface, although this is not perfect yet. In the present experiment, we observed three typical types of the 2-D rupture propagation patterns, two of which were initiated at a single location either close to the fault edge or inside the fault. This initiation could be accelerated by the free surface effect at the fault edge. The third one was initiated at multiple locations and had a rupture coalescence at the middle of the fault. These geometrically complicated rupture initiation patterns are important for understanding the earthquake nucleation process in nature.

The transition of dynamic rupture styles in elastic media under velocity-weakening friction

NASA Astrophysics Data System (ADS)

Gabriel, A.-A.; Ampuero, J.-P.; Dalguer, L. A.; Mai, P. M.

2012-09-01

Although kinematic earthquake source inversions show dominantly pulse-like subshear rupture behavior, seismological observations, laboratory experiments and theoretical models indicate that earthquakes can operate with different rupture styles: either as pulses or cracks, that propagate at subshear or supershear speeds. The determination of rupture style and speed has important implications for ground motions and may inform about the state of stress and strength of active fault zones. We conduct 2D in-plane dynamic rupture simulations with a spectral element method to investigate the diversity of rupture styles on faults governed by velocity-and-state-dependent friction with dramatic velocity-weakening at high slip rate. Our rupture models are governed by uniform initial stresses, and are artificially initiated. We identify the conditions that lead to different rupture styles by investigating the transitions between decaying, steady state and growing pulses, cracks, sub-shear and super-shear ruptures as a function of background stress, nucleation size and characteristic velocity at the onset of severe weakening. Our models show that small changes of background stress or nucleation size may lead to dramatic changes of rupture style. We characterize the asymptotic properties of steady state and self-similar pulses as a function of background stress. We show that an earthquake may not be restricted to a single rupture style, but that complex rupture patterns may emerge that consist of multiple rupture fronts, possibly involving different styles and back-propagating fronts. We also demonstrate the possibility of a super-shear transition for pulse-like ruptures. Finally, we draw connections between our findings and recent seismological observations.

The effect of segmented fault zones on earthquake rupture propagation and termination

NASA Astrophysics Data System (ADS)

Huang, Y.

2017-12-01

A fundamental question in earthquake source physics is what can control the nucleation and termination of an earthquake rupture. Besides stress heterogeneities and variations in frictional properties, damaged fault zones (DFZs) that surround major strike-slip faults can contribute significantly to earthquake rupture propagation. Previous earthquake rupture simulations usually characterize DFZs as several-hundred-meter-wide layers with lower seismic velocities than host rocks, and find earthquake ruptures in DFZs can exhibit slip pulses and oscillating rupture speeds that ultimately enhance high-frequency ground motions. However, real DFZs are more complex than the uniform low-velocity structures, and show along-strike variations of damages that may be correlated with historical earthquake ruptures. These segmented structures can either prohibit or assist rupture propagation and significantly affect the final sizes of earthquakes. For example, recent dense array data recorded at the San Jacinto fault zone suggests the existence of three prominent DFZs across the Anza seismic gap and the south section of the Clark branch, while no prominent DFZs were identified near the ends of the Anza seismic gap. To better understand earthquake rupture in segmented fault zones, we will present dynamic rupture simulations that calculate the time-varying rupture process physically by considering the interactions between fault stresses, fault frictional properties, and material heterogeneities. We will show that whether an earthquake rupture can break through the intact rock outside the DFZ depend on the nucleation size of the earthquake and the rupture propagation distance in the DFZ. Moreover, material properties of the DFZ, stress conditions along the fault, and friction properties of the fault also have a critical impact on rupture propagation and termination. We will also present scenarios of San Jacinto earthquake ruptures and show the parameter space that is favorable for rupture propagation through the Anza seismic gap. Our results suggest that a priori knowledge of properties of segmented fault zones is of great importance for predicting sizes of future large earthquakes on major faults.

Re-rupture rate of primarily repaired distal biceps tendon injuries.

PubMed

Hinchey, John W; Aronowitz, Jessica G; Sanchez-Sotelo, Joaquin; Morrey, Bernard F

2014-06-01

Distal biceps tendon rupture is a common injury, and primary repair results in excellent return of function and strength. Complications resulting from distal biceps tendon repairs are well reported, but the incidence of re-ruptures has never been investigated. A search of the Mayo Clinic's Medical/Surgical Index was performed, and all distal biceps tendon repairs from January 1981 through May 2009 were identified. All patients who completed 12 months or more of follow-up were included. All charts were reviewed and patients contacted as necessary to identify a re-rupture. We also investigated the situation causing the re-rupture. We identified a total of 190 distal biceps tendon ruptures that underwent repair and met our inclusion and exclusion criteria. Of the 190 repairs, 172 (90.5%) were performed by the Mayo modification of the Boyd-Anderson 2-incision technique. Bilateral ruptures occurred in 13 patients (7.3%). Six primary ruptures (3.2%) occurred in women, 4 of the 6 being partial ruptures. Partial ruptures were found to be statistically more common than complete ruptures in women (P = .05). We identified 3 re-ruptures (1.5%), all occurring within 3 weeks of the index surgery. The re-rupture rate after primary repair of the distal biceps tendon is low at 1.5% and occurs within 3 weeks of index repair. This appears to be due to patient compliance and excessive force placed on repairs. We also found the incidence of women who sustain a distal biceps tendon tear to be 3.2%, with partial tears being statistically more common than complete ruptures. Level IV, case series, treatment study Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Kinematic Rupture Process of the 2015 Gorkha (Nepal) Earthquake Sequence from Joint Inversion of Teleseismic, hr-GPS, Strong-Ground Motion, InSAR interferograms and pixel offsets

NASA Astrophysics Data System (ADS)

Yue, H.; Simons, M.; Jiang, J.; Fielding, E. J.; Owen, S. E.; Moore, A. W.; Riel, B. V.; Polet, J.; Duputel, Z.; Samsonov, S. V.; Avouac, J. P.

2015-12-01

The April 2015 Gorkha, Nepal (Mw 7.8) earthquake ruptured the front of Himalaya thrust belt, causing more than 9,000 fatalities. 17 days after the main event, a large aftershock (Mw 7.2) ruptured to down-dip and east of the main rupture area. To investigate the kinematic rupture process of this earthquake sequence, we explored linear and non-linear inversion techniques using a variety of datasets including teleseismic, high rate and conventional GPS, InSAR interferograms and pixel-offsets. InSAR interferograms from ALOS-2, RADARSAT-2 and Sentinel-1a satellites are used in the joint inversion. The main event is characterized by unilateral rupture extending along strike approximately 70 km to the southeast and 40 km along dip direction. The rupture velocity is well resolved to be lie between 2.8 and 3.0 km/s, which is consistent with back-projection results. An emergent initial phase is observed in teleseismic body wave records, which is consistent with a narrow area of rupture initiation near the hypocenter. The rupture mode of the main event is pulse like. The aftershock ruptured down-dip to the northeast of the main event rupture area. The aftershock rupture area is compact and contained within 40 km of its hypocenter. In contrast to the main event, teleseismic body wave records of the aftershock suggest an abrupt initial phase, which is consistent with a crack like rupture mode. The locations of most of the aftershocks (small and large) surround the rupture area of the main shock with little, if any, spatial overlap.

Identification of oocyte progenitor cells in the zebrafish ovary.

PubMed

Draper, Bruce W

2012-01-01

Zebrafish breed year round and females are capable of producing thousands of eggs during their lifetime. This amazing fecundity is due to the fact that the adult ovary, contains premeiotic oocyte progenitor cells, called oogonia, which produce a continuous supply of new oocytes throughout adult life. Oocyte progenitor cells can be easily identified based on their expression of Vasa, and their characteristic nuclear morphology. Thus, the zebrafish ovary provides a unique and powerful system to study the genetic regulation of oocyte production in a vertebrate animal. A method is presented here for identifying oocyte progenitor cells in the zebrafish ovary using whole-mount confocal immunofluorescence that is simple and accurate.

Peripheral Neuropathy and Nerve Compression Syndromes in Burns.

PubMed

Strong, Amy L; Agarwal, Shailesh; Cederna, Paul S; Levi, Benjamin

2017-10-01

Peripheral neuropathy and nerve compression syndromes lead to substantial morbidity following burn injury. Patients present with pain, paresthesias, or weakness along a specific nerve distribution or experience generalized peripheral neuropathy. The symptoms manifest at various times from within one week of hospitalization to many months after wound closure. Peripheral neuropathy may be caused by vascular occlusion of vasa nervorum, inflammation, neurotoxin production leading to apoptosis, and direct destruction of nerves from the burn injury. This article discusses the natural history, diagnosis, current treatments, and future directions for potential interventions for peripheral neuropathy and nerve compression syndromes related to burn injury. Copyright © 2017 Elsevier Inc. All rights reserved.

Revising the phylogenetic position of the extinct Mascarene Parrot Mascarinus mascarin (Linnaeus 1771) (Aves: Psittaciformes: Psittacidae).

PubMed

Podsiadlowski, Lars; Gamauf, Anita; Töpfer, Till

2017-02-01

The phylogenetic position of the extinct Mascarene Parrot Mascarinus mascarin from La Réunion has been unresolved for centuries. A recent molecular study unexpectedly placed M. mascarin within the clade of phenotypically very different Vasa parrots Coracopsis. Based on DNA extracted from the only other preserved Mascarinus specimen, we show that the previously obtained cytb sequence is probably an artificial composite of partial sequences from two other parrot species and that M. mascarin is indeed a part of the Psittacula diversification, placed close to P. eupatria and P. wardi. Copyright © 2016 Elsevier Inc. All rights reserved.

Influence of morphology and hemodynamic factors on rupture of multiple intracranial aneurysms: matched-pairs of ruptured-unruptured aneurysms located unilaterally on the anterior circulation.

PubMed

Zhang, Ying; Yang, Xinjian; Wang, Yang; Liu, Jian; Li, Chuanhui; Jing, Linkai; Wang, Shengzhang; Li, Haiyun

2014-12-31

The authors evaluated the impact of morphological and hemodynamic factors on the rupture of matched-pairs of ruptured-unruptured intracranial aneurysms on one patient's ipsilateral anterior circulation with 3D reconstruction model and computational fluid dynamic method simulation. 20 patients with intracranial aneurysms pairs on the same-side of anterior circulation but with different rupture status were retrospectively collected. Each pair was divided into ruptured-unruptured group. Patient-specific models based on their 3D-DSA images were constructed and analyzed. The relative locations, morphologic and hemodynamic factors of these two groups were compared. There was no significant difference in the relative bleeding location. The morphological factors analysis found that the ruptured aneurysms more often had irregular shape and had significantly higher maximum height and aspect ratio. The hemodynamic factors analysis found lower minimum wall shear stress (WSSmin) and more low-wall shear stress-area (LSA) in the ruptured aneurysms than that of the unruptured ones. The ruptured aneurysms more often had WSSmin on the dome. Intracranial aneurysms pairs with different rupture status on unilateral side of anterior circulation may be a good disease model to investigate possible characteristics linked to rupture independent of patient characteristics. Irregular shape, larger size, higher aspect ratio, lower WSSmin and more LSA may indicate a higher risk for their rupture.

Characterize kinematic rupture history of large earthquakes with Multiple Haskell sources

NASA Astrophysics Data System (ADS)

Jia, Z.; Zhan, Z.

2017-12-01

Earthquakes are often regarded as continuous rupture along a single fault, but the occurrence of complex large events involving multiple faults and dynamic triggering challenges this view. Such rupture complexities cause difficulties in existing finite fault inversion algorithms, because they rely on specific parameterizations and regularizations to obtain physically meaningful solutions. Furthermore, it is difficult to assess reliability and uncertainty of obtained rupture models. Here we develop a Multi-Haskell Source (MHS) method to estimate rupture process of large earthquakes as a series of sub-events of varying location, timing and directivity. Each sub-event is characterized by a Haskell rupture model with uniform dislocation and constant unilateral rupture velocity. This flexible yet simple source parameterization allows us to constrain first-order rupture complexity of large earthquakes robustly. Additionally, relatively few parameters in the inverse problem yields improved uncertainty analysis based on Markov chain Monte Carlo sampling in a Bayesian framework. Synthetic tests and application of MHS method on real earthquakes show that our method can capture major features of large earthquake rupture process, and provide information for more detailed rupture history analysis.

Geologic Inheritance and Earthquake Rupture Processes: The 1905 M ≥ 8 Tsetserleg-Bulnay Strike-Slip Earthquake Sequence, Mongolia

NASA Astrophysics Data System (ADS)

Choi, Jin-Hyuck; Klinger, Yann; Ferry, Matthieu; Ritz, Jean-François; Kurtz, Robin; Rizza, Magali; Bollinger, Laurent; Davaasambuu, Battogtokh; Tsend-Ayush, Nyambayar; Demberel, Sodnomsambuu

2018-02-01

In 1905, 14 days apart, two M 8 continental strike-slip earthquakes, the Tsetserleg and Bulnay earthquakes, occurred on the Bulnay fault system, in Mongolia. Together, they ruptured four individual faults, with a total length of 676 km. Using submetric optical satellite images "Pleiades" with ground resolution of 0.5 m, complemented by field observation, we mapped in detail the entire surface rupture associated with this earthquake sequence. Surface rupture along the main Bulnay fault is 388 km in length, striking nearly E-W. The rupture is formed by a series of fault segments that are 29 km long on average, separated by geometric discontinuities. Although there is a difference of about 2 m in the average slip between the western and eastern parts of the Bulnay rupture, along-fault slip variations are overall limited, resulting in a smooth slip distribution, except for local slip deficit at segment boundaries. We show that damage, including short branches and secondary faulting, associated with the rupture propagation, occurred significantly more often along the western part of the Bulnay rupture, while the eastern part of the rupture appears more localized and thus possibly structurally simpler. Eventually, the difference of slip between the western and eastern parts of the rupture is attributed to this difference of rupture localization, associated at first order with a lateral change in the local geology. Damage associated to rupture branching appears to be located asymmetrically along the extensional side of the strike-slip rupture and shows a strong dependence on structural geologic inheritance.

Rupture rate and patterns of shell failure with the McGhan Style 153 double-lumen breast implant.

PubMed

Neaman, Keith C; Albert, Mark; Hammond, Dennis C

2011-01-01

In 2005, the McGhan Style 153 double-lumen breast implant was removed from the market secondary to a higher rupture rate when contrasted with other implants in the Core Study group. The high rupture rate was attributed to the development of a posterior tear in the shell where the inner implant is bonded to the posterior wall of the device. The purpose of this study was to report the existing rupture rate and describe the apparent mechanism of failure in the Style 153 double-lumen breast implant. Ninety-seven patients (157 implants) who received the McGhan Style 153 double-lumen breast implant by the senior author were reviewed. Intraoperative observations and photographic images of ruptured implants were reviewed and characterized based on severity and location of implant rupture. With a mean length of follow-up of greater than 6 years (82 months), the rupture rate was 19.1 percent per implant. Physical examination (60 percent) was the most common method of rupture detection. Ruptures tended to occur in the marginal aspect (63 percent) of the implant. Only three ruptures occurred secondary to a disruption of the inner bladder from the posterior portion of the implant. The rupture rate of the Style 153 double-lumen breast implant is higher than previously thought, with a rate of 19.1 percent. A majority of ruptures occurred in the peripheral aspects of the implant. It is postulated that these ruptures were likely secondary to fold flaws that led to failure of the implant shell.

Multiple tendon ruptures of unknown etiology.

PubMed

Axibal, Derek P; Anderson, John G

2013-10-01

Tendon ruptures are common findings in foot and ankle practice. The etiology of tendon ruptures tends to be multifactorial-usually due to a combination of trauma, effects of systemic diseases, adverse effects of medications, and obesity. We present an unusual case of right Achilles tendinitis, left Achilles tendon rupture, bilateral peroneus longus tendon rupture, and left peroneus brevis tendon rupture of unknown etiology. This case report highlights the need for research for other possible, lesser known etiologies of tendon pathology. Therapeutic, Level IV, Case Study.

Heroin Use Is Associated with Ruptured Saccular Aneurysms.

PubMed

Can, Anil; Castro, Victor M; Ozdemir, Yildirim H; Dagen, Sarajune; Dligach, Dmitriy; Finan, Sean; Yu, Sheng; Gainer, Vivian; Shadick, Nancy A; Savova, Guergana; Murphy, Shawn; Cai, Tianxi; Weiss, Scott T; Du, Rose

2017-11-04

While cocaine use is thought to be associated with aneurysmal rupture, it is not known whether heroin use increases the risk of rupture in patients with non-mycotic saccular aneurysms. Our goal was to investigate the association between heroin and cocaine use and the rupture of saccular non-mycotic aneurysms. The medical records of 4701 patients with 6411 intracranial aneurysms, including 1201 prospective patients, diagnosed at the Brigham and Women's Hospital and Massachusetts General Hospital between 1990 and 2016 were reviewed and analyzed. Patients were separated into ruptured and non-ruptured groups. Univariable and multivariable logistic regression analyses were performed to determine the association between heroin, cocaine, and methadone use and the presence of ruptured intracranial aneurysms. In multivariable analysis, current heroin use was significantly associated with rupture status (OR 3.23, 95% CI 1.33-7.83) whereas former heroin use (with and without methadone replacement therapy), and current and former cocaine use were not significantly associated with intracranial aneurysm rupture. In the present study, heroin rather than cocaine use is significantly associated with intracranial aneurysm rupture in patients with non-mycotic saccular cerebral aneurysms, emphasizing the possible role of heroin in the pathophysiology of aneurysm rupture and the importance of heroin cessation in patients harboring unruptured intracranial aneurysms.

Fault zones ruptured during the early 2014 Cephalonia Island (Ionian Sea, Western Greece) earthquakes (January 26 and February 3, Mw 6.0) based on the associated co-seismic surface ruptures

NASA Astrophysics Data System (ADS)

Lekkas, Efthymios L.; Mavroulis, Spyridon D.

2016-01-01

The early 2014 Cephalonia Island (Ionian Sea, Western Greece) earthquake sequence comprised two main shocks with almost the same magnitude (moment magnitude (Mw) 6.0) occurring successively within a short time (January 26 and February 3) and space (Paliki peninsula in Western Cephalonia) interval. Εach earthquake was induced by the rupture of a different pre-existing onshore active fault zone and produced different co-seismic surface rupture zones. Co-seismic surface rupture structures were predominantly strike-slip-related structures including V-shaped conjugate surface ruptures, dextral and sinistral strike-slip surface ruptures, restraining and releasing bends, Riedel structures ( R, R', P, T), small-scale bookshelf faulting, and flower structures. An extensional component was present across surface rupture zones resulting in ground openings (sinkholes), small-scale grabens, and co-seismic dip-slip (normal) displacements. A compressional component was also present across surface rupture zones resulting in co-seismic dip-slip (reverse) displacements. From the comparison of our field geological observations with already published surface deformation measurements by DInSAR Interferometry, it is concluded that there is a strong correlation among the surface rupture zones, the ruptured active fault zones, and the detected displacement discontinuities in Paliki peninsula.

Describing Soils: Calibration Tool for Teaching Soil Rupture Resistance

ERIC Educational Resources Information Center

Seybold, C. A.; Harms, D. S.; Grossman, R. B.

2009-01-01

Rupture resistance is a measure of the strength of a soil to withstand an applied stress or resist deformation. In soil survey, during routine soil descriptions, rupture resistance is described for each horizon or layer in the soil profile. The lower portion of the rupture resistance classes are assigned based on rupture between thumb and…

Geological structures control on earthquake ruptures: The Mw7.7, 2013, Balochistan earthquake, Pakistan

NASA Astrophysics Data System (ADS)

Vallage, A.; Klinger, Y.; Lacassin, R.; Delorme, A.; Pierrot-Deseilligny, M.

2016-10-01

The 2013 Mw7.7 Balochistan earthquake, Pakistan, ruptured the Hoshab fault. Left-lateral motion dominated the deformation pattern, although significant vertical motion is found along the southern part of the rupture. Correlation of high-resolution (2.5 m) optical satellite images provided horizontal displacement along the entire rupture. In parallel, we mapped the ground rupture geometry at 1:500 scale. We show that the azimuth of the ground rupture distributes mainly between two directions, N216° and N259°. The direction N216° matches the direction of preexisting geologic structures resulting from penetrative deformation caused by the nearby Makran subduction. Hence, during a significant part of its rupture, the 2013 Balochistan rupture kept switching between a long-term fault front and secondary branches, in which existence and direction are related to the compressional context. It shows unambiguous direct interactions between different preexisting geologic structures, regional stress, and dynamic-rupture stress, which controlled earthquake propagation path.

Mathematical modeling and numerical simulation of unilateral dynamic rupture propagation along very-long reverse faults

NASA Astrophysics Data System (ADS)

Hirano, S.

2017-12-01

For some great earthquakes, dynamic rupture propagates unilaterally along a horizontal direction of very-long reverse faults (e.g., the Mw9.1 Sumatra earthquake in 2004, the Mw8.0 Wenchuan earthquake in 2008, and the Mw8.8 Maule earthquake in 2010, etc.). It seems that barriers or creeping sections may not lay along the opposite region of the co-seismically ruptured direction. In fact, in the case of Sumatra, the Mw8.6 earthquake occurred in the opposite region only three months after the mainshock. Mechanism of unilateral mode-II rupture along a material interface has been investigated theoretically and numerically. For mode-II rupture propagating along a material interface, an analytical solution implies that co-seismic stress perturbation depends on the rupture direction (Weertman, 1980 JGR; Hirano & Yamashita, 2016 BSSA), and numerical modeling of plastic yielding contributes to simulating the unilateral rupture (DeDonteny et al., 2011 JGR). However, mode-III rupture may dominate for the very-long reverse faults, and it can be shown that stress perturbation due to mode-III rupture does not depend on the rupture direction. Hence, an effect of the material interface is insufficient to understand the mechanism of unilateral rupture along the very-long reverse faults. In this study, I consider a two-dimensional bimaterial system with interfacial dynamic mode-III rupture under an obliquely pre-stressed configuration (i.e., the maximum shear direction of the background stress is inclined from the interfacial fault). First, I derived an analytical solution of regularized elastic stress field around a steady-state interfacial slip pulse using the method of Rice et al. (2005 BSSA). Then I found that the total stress, which is the sum of the background stress and co-seismic stress perturbation, depends on the rupture direction even in the mode-III case. Second, I executed a finite difference numerical simulation with a plastic yielding model of Andrews (1978 JGR; 2005 JGR) and succeeded in a simulation of unilateral rupture propagation in some parameter ranges (see figure). This unilateral rupture might be caused by energy dissipation due to the plastic yielding process that concentrates in the vicinity of only one rupture tip depending on the rupture direction.

Laparoscopic uterine surgery as a risk factor for uterine rupture during pregnancy.

PubMed

Chao, An-Shine; Chang, Yao-Lung; Yang, Lan-Yan; Chao, Angel; Chang, Wei-Yang; Su, Sheng-Yuan; Wang, Chin-Jung

2018-01-01

The incidence of uterine rupture through a previous cesarean scar (CS) is declining as a result of a lower parity and fewer options for vaginal birth after cesarean. However, uterine ruptures attributable to other causes that traumatize the myometrium are on the rise. To determine whether changes in the causes of uterine rupture had occurred in recent years, we retrospective retrieved the clinical records of all singletons with uterine rupture observed in the delivery room of a Taiwanese tertiary obstetric center over a 15-year period. The overall uterine rupture rate was 3.8 per 10,000 deliveries. A total of 22 cases in 20 women (with two of them experiencing two episodes). Seven uterine ruptures occurred through a previous cesarean scar (CS ruptures, 32%), 13 through a non-cesarean scar (non-CS ruptures, 59%), whereas the remaining two (9%) were in women who did not previously undergo any surgery. All of the 13 non-CS ruptures were identified in women with a history of laparoscopic procedures to the uterus. Specifically, 10 (76%) occurred after a previous laparoscopic myomectomy, one (8%) following a hysteroscopic myomectomy, and two (16%) after a laparoscopic wedge resection of cornual ectopic pregnancy. Severe bleeding (blood loss >1500 mL) requiring transfusions was more frequent in women who experienced non-CS compared with CS ruptures (10 versus 1 case, respectively, P = 0.024). Patients with a history of endoscopic uterine surgery should be aware of uterine rupture during pregnancy.

Laparoscopic uterine surgery as a risk factor for uterine rupture during pregnancy

PubMed Central

Chao, An-Shine; Chang, Yao-Lung; Yang, Lan-Yan; Chao, Angel; Chang, Wei-Yang; Su, Sheng-Yuan

2018-01-01

The incidence of uterine rupture through a previous cesarean scar (CS) is declining as a result of a lower parity and fewer options for vaginal birth after cesarean. However, uterine ruptures attributable to other causes that traumatize the myometrium are on the rise. To determine whether changes in the causes of uterine rupture had occurred in recent years, we retrospective retrieved the clinical records of all singletons with uterine rupture observed in the delivery room of a Taiwanese tertiary obstetric center over a 15-year period. The overall uterine rupture rate was 3.8 per 10,000 deliveries. A total of 22 cases in 20 women (with two of them experiencing two episodes). Seven uterine ruptures occurred through a previous cesarean scar (CS ruptures, 32%), 13 through a non-cesarean scar (non-CS ruptures, 59%), whereas the remaining two (9%) were in women who did not previously undergo any surgery. All of the 13 non-CS ruptures were identified in women with a history of laparoscopic procedures to the uterus. Specifically, 10 (76%) occurred after a previous laparoscopic myomectomy, one (8%) following a hysteroscopic myomectomy, and two (16%) after a laparoscopic wedge resection of cornual ectopic pregnancy. Severe bleeding (blood loss >1500 mL) requiring transfusions was more frequent in women who experienced non-CS compared with CS ruptures (10 versus 1 case, respectively, P = 0.024). Patients with a history of endoscopic uterine surgery should be aware of uterine rupture during pregnancy. PMID:29787604

Penile fracture: a rare case of simultaneous rupture of the one corpus cavernosum and complete urethral rupture.

PubMed

Nale, Djordje; Bojanić, Nebojša; Nikić, Predrag

2015-01-01

Penile fracture is a traumatic rupture of tunica albuginea and the tumescent corpora cavernosa due to the nonphysiological bending of the penile shaft, presenting with or without rupture of corpus pongiosum and urethra. The incidence of concomitant injury of the urethra is 0-38%. Complete urethral rupture is rare, but it is almost always associated with bilateral corporeal injury. We presented a patient with complete urethral rupture, and rupture of the right cavernous body. According to the available literature, this case is extremely rare. Fracture of the penis is relatively uncommon and is considered a urologic emergency. Prompt surgical explo- ration and repair can preserve erectile and voiding function.

Linguine sign in musculoskeletal imaging: calf silicone implant rupture.

PubMed

Duryea, Dennis; Petscavage-Thomas, Jonelle; Frauenhoffer, Elizabeth E; Walker, Eric A

2015-08-01

Imaging findings of breast silicone implant rupture are well described in the literature. On MRI, the linguine sign indicates intracapsular rupture, while the presence of silicone particles outside the fibrous capsule indicates extracapsular rupture. The linguine sign is described as the thin, wavy hypodense wall of the implant within the hyperintense silicone on T2-weighted images indicative of rupture of the implant within the naturally formed fibrous capsule. Hyperintense T2 signal outside of the fibrous capsule is indicative of an extracapsular rupture with silicone granuloma formation. We present a rare case of a patient with a silicone calf implant rupture and discuss the MRI findings associated with this condition.

Distal Biceps Tendon Rupture

DTIC Science & Technology

2010-06-01

Distal Biceps Tendon Rupture Military Medicine Radiology Corner, 2006 Radiology Corner Distal Biceps Tendon Rupture Contributors: CPT Michael...treatment of a 56-year-old man with complete rupture of the distal biceps tendon . The mechanism of injury, symptoms, and findings at physical...be used in pre-operative planning. Introduction Rupture of the distal biceps tendon is a relatively uncommon injury, but delayed diagnosis may

Creep-rupture behavior of candidate Stirling engine iron supperalloys in high-pressure hydrogen. Volume 2: Hydrogen creep-rupture behavior

NASA Technical Reports Server (NTRS)

Bhattacharyya, S.; Peterman, W.; Hales, C.

1984-01-01

The creep rupture behavior of nine iron base and one cobalt base candidate Stirling engine alloys is evaluated. Rupture life, minimum creep rate, and time to 1% strain data are analyzed. The 3500 h rupture life stress and stress to obtain 1% strain in 3500 h are also estimated.

A comparison of pre-dropout and temporary rupture sessions in psychotherapy.

PubMed

Gülüm, I Volkan; Soygüt, Gonca; Safran, Jeremy D

2016-11-15

Although numerous studies have investigated the relationship between the therapeutic alliance and dropout, most have focused on the relationship between alliance quality and psychotherapy outcomes. To compare sessions with therapeutic alliance ruptures and two sessions prior to treatment dropout (pre-dropout) in terms of rupture subtypes, psychotherapists' behavior, attitudes, and session content. We implemented quantitative methods to select the sessions and qualitative methods to analyze them. We analyzed 16 temporary rupture sessions from 12 therapist-patient dyads and 16 pre-dropout sessions from 8 different therapist-patient dyads. The sessions originate from clinical psychology Master's or Doctoral students under supervision in either cognitive behavioral or schema therapy. Pre-dropout sessions were considered unrepaired rupture sessions while rupture sessions were subsequently repaired. Results revealed apparent differences and similarities between the session types in positive and negative psychotherapist behaviors, content intensity, and the type and frequency of ruptures. We explored three new rupture subtypes: attributing positive developments to other sources, indirect speech, and sarcastic hostility. A striking implication is that the frequency of positive and negative psychotherapist behaviors, ruptures, and session content is more likely to decrease in the pre-dropout sessions than in the temporary rupture sessions.

Clinical recovery of two hip adductor longus ruptures: a case-report of a soccer player

PubMed Central

2013-01-01

Background Non-operative treatment of acute hip adductor longus ruptures in athletes has been described in the literature. However, very limited information concerning the recovery of this type of injury exists. This case represented a unique possibility to study the recovery of two acute adductor longus ruptures, using novel, reliable and validated assessment methods. Case presentation A 22-year old male soccer player (Caucasian) sustained two subsequent acute adductor longus ruptures, one in each leg. The injuries occurred 10 months apart, and were treated non-surgically in both situations. He was evaluated using hip-strength assessments, self-report and ultrasonography until complete muscle-strength recovery of the hip adductors had occurred. The player was able to participate in a full soccer training session without experiencing pain 15 weeks after the first rupture, and 12 weeks after the second rupture. Full hip adductor muscle-strength recovery was obtained 52 weeks after the first rupture and 10 weeks after the second rupture. The adductor longus injuries, as verified by initial ultrasonography (10 days post-injury), showed evidence of a complete tendon rupture in both cases, with an almost identical imaging appearance. It was only at 6 and 10 weeks ultrasonographic follow-up that the first rupture was found to include a larger anatomical area than the second rupture. Conclusion From this case we can conclude that two apparently similar hip adductor longus ruptures, verified by initial ultrasonography (10 days post-injury), can have very different hip adductor strength recovery times. Assessment of adductor strength recovery may therefore in the future be a useful and important additional measure for determining when soccer players with hip adductor longus ruptures can return safely to play. PMID:23693119

Spontaneous rupture of splenic artery aneurysm in pregnancy: a case report.

PubMed

Gourgiotis, S; Alfaras, P; Salemis, N S

2008-01-01

Splenic artery aneurysms (SAA) occur predominantly in women, and the majority of them are asymptomatic until rupture. Over half of those that rupture occur during pregnancy. Spontaneously ruptured SAA during pregnancy is always a life-threatening surgical entity for both the mother and the fetus. We report the case of a 29-year-old woman at 34 weeks' gestation with spontaneous rupture of SAA who underwent emergency exploratory laparotomy and splenectomy. This case illustrates the need to consider ruptured SAA as part of important differential diagnosis in haemodynamically unstable pregnant women.

Glass rupture disk

DOEpatents

Glass, S. Jill; Nicolaysen, Scott D.; Beauchamp, Edwin K.

2002-01-01

A frangible rupture disk and mounting apparatus for use in blocking fluid flow, generally in a fluid conducting conduit such as a well casing, a well tubing string or other conduits within subterranean boreholes. The disk can also be utilized in above-surface pipes or tanks where temporary and controllable fluid blockage is required. The frangible rupture disk is made from a pre-stressed glass with controllable rupture properties wherein the strength distribution has a standard deviation less than approximately 5% from the mean strength. The frangible rupture disk has controllable operating pressures and rupture pressures.

Surface fault rupture during the Mw 7.8 Kaikoura earthquake, New Zealand, with specific comment on the Kekerengu Fault - one of the country's fastest slipping onland active faults

NASA Astrophysics Data System (ADS)

Van Dissen, Russ; Little, Tim

2017-04-01

The Mw 7.8 Kaikoura earthquake of 14 November, 2016 (NZDT) was a complex event. It involved ground-surface (or seafloor) fault rupture on at least a dozen onland or offshore faults, and subsurface rupture on a handful of additional faults. Most of the surface ruptures involved previously known (or suspected) active faults, as well as surface rupture on at least two hitherto unrecognised active faults. The southwest to northeast extent of surface fault rupture, as generalised by two straight-line segments, is approximately 180 km, though this is a minimum for the collective length of surface rupture due to multiple overlapping faults with various orientations. Surface rupture displacements on specific faults involved in the Kaikoura Earthquake span approximately two orders of magnitude. For example, maximum surface displacement on the Heaver's Creek Fault is cm- to dm-scale in size; whereas, maximum surface displacement on the nearby Kekerengu Fault is approximately 10-12 m (predominantly in a dextral sense). The Kekerengu Fault has a Late Pleistocene slip-rate rate of 20-26 mm/yr, and is possibly the second fastest slipping onland fault in New Zealand, behind the Alpine Fault. Located in the northeastern South Island of New Zealand, the Kekerengu Fault - along with the Hope Fault to the southwest and the Needles Fault offshore to the northeast - comprise the fastest slipping elements of the Pacific-Australian plate boundary in this part of the country. In January 2016 (about ten months prior to the Kaikoura earthquake) three paleo-earthquake investigation trenches were excavated across pronounced traces of the Kekerengu Fault at two locations. These were the first such trenches dug and evaluated across the fault. All three trenches displayed abundant evidence of past surface fault ruptures (three surface ruptures in the last approximately 1,200 years, four now including the 2016 rupture). An interesting aspect of the 2016 rupture is that two of the trenches received surface fault rupture, and are now dextrally offset by about 9 m, while the third trench did not have any 2016 surface rupture pass through it. In this instance, ground-surface rupture along this trace of the fault died out within tens of metres of the trench. Another salient aspect of the Kaikoura earthquake is that the determined (or estimated) recurrence intervals of the faults that ruptured the ground surface vary by an order of magnitude or more. This strongly implies that the ensemble of faults that ruptured with the Kekerengu Fault in the 2016 earthquake has not always been the same for past earthquakes. Possible reasons for this could include the state of stress at the time of a specific earthquake, the direction of rupture propagation, and whether or not rupture on one fault system cascades into rupture on another as is suspected to have happened in the Kaikoura earthquake.

Surface Rupture Characteristics and Rupture Mechanics of the Yushu Earthquake (Ms7.1), 14/04/2010

NASA Astrophysics Data System (ADS)

Pan, J.; Li, H.; Xu, Z.; Li, N.; Wu, F.; Guo, R.; Zhang, W.

2010-12-01

On April 14th 2010, a disastrous earthquake (Ms 7.1) struck Yushu County, Qinghai Province, China, killing thousands of people. This earthquake occurred as a result of sinistral strike-slip faulting on the western segment of the Xianshuihe Fault zone in eastern Tibetan Plateau. Our group conducted scientific investigation in the field on co-seismic surface rupture and active tectonics in the epicenter area immediately after the earthquake. Here, we introduce our preliminary results on the surface ruptures and rupture mechanics of the Yushu Earthquake. The surface rupture zone of Yushu earthquake, which is about 49 km-long, consists of 3 discontinuous left stepping rupture segments, which are 19 km, 22 km, and about 8 km, respectively, from west to east. Each segment consists of a series of right stepping en-echelon branch ruptures. The branch ruptures consist of interphase push-up and tension fissures or simply en-echelon tension fissures. The co-seismic displacements had been surveyed with a total station in detail on landmarks such as rivers, gullies, roads, farmlands, wire poles, and fences. The maximum offset measured is 2.3m, located near the Guoyangyansongduo Village. There are 3 offset peaks along the rupture zone corresponding to the 3 segments of the surface rupture zone. The maximum offsets in the west, central, and east segment rupture zones are 1.4m, 2.3m, and 1.6m respectively. The surface rupture zone of Yushu earthquake strikes in a 310°NW direction. The fault plane dips to the northeast and the dip angle is about 81°. The rupture zone is developed in transtension setting. Tension normal fault developed during the sinistral strike-slip process of the fault. The valley west of Yushu City and the Longbao Lake are both pull-apart basins formed during the transtension activity of the fault.

Historic Surface Rupture Informing Probabilistic Fault Displacement Analysis: New Zealand Case Studies

NASA Astrophysics Data System (ADS)

Villamor, P.; Litchfield, N. J.; Van Dissen, R. J.; Langridge, R.; Berryman, K. R.; Baize, S.

2016-12-01

Surface rupture associated with the 2010 Mw7.1 Darfield Earthquake (South Island, New Zealand) was extremely well documented, thanks to an immediate field mapping response and the acquisition of LiDAR data within days of the event. With respect to informing Probabilistic Fault Displacement Analysis (PFDHA) the main insights and outcomes from this rupture through Quaternary gravel are: 1) significant distributed deformation either side of the main trace (30 to 300 m wide deformation zone) and how the deformation is distributed away from the main trace; 2) a thorough analysis of uncertainty of the displacement measures obtained using the LIDAR data and repeated measurements from several scientists; and 3) the short surface rupture length for the reported magnitude, resulting from complex fault rupture with 5-6 reverse and strike-slip strands, most of which had no surface rupture. While the 2010 event is extremely well documented and will be an excellent case to add to the Surface Rupture during Earthquakes database (SURE), other NZ historical earthquakes that are not so well documented, but can provide important information for PFDHA. New Zealand has experienced about 10 historical surface fault ruptures since 1848, comprising ruptures on strike-slip, reverse and normal faults. Mw associated with these ruptures ranges between 6.3 and 8.1. From these ruptures we observed that the surface expression of deformation can be influenced by: fault maturity; the type of Quaternary sedimentary cover; fault history (e.g., influence of inversion tectonics, flexural slip); fault complexity; and primary versus secondary rupture. Other recent >Mw 6.6 earthquakes post-2010 that did not rupture the ground surface have been documented with InSAR and can inform Mw thresholds for surface fault rupture. It will be important to capture all this information and that of similar events worldwide to inform the SURE database and ultimately PFDHA.

Global catalog of earthquake rupture velocities shows anticorrelation between stress drop and rupture velocity

NASA Astrophysics Data System (ADS)

Chounet, Agnès; Vallée, Martin; Causse, Mathieu; Courboulex, Françoise

2018-05-01

Application of the SCARDEC method provides the apparent source time functions together with seismic moment, depth, and focal mechanism, for most of the recent earthquakes with magnitude larger than 5.6-6. Using this large dataset, we have developed a method to systematically invert for the rupture direction and average rupture velocity Vr, when unilateral rupture propagation dominates. The approach is applied to all the shallow (z < 120 km) earthquakes of the catalog over the 1992-2015 time period. After a careful validation process, rupture properties for a catalog of 96 earthquakes are obtained. The subsequent analysis of this catalog provides several insights about the seismic rupture process. We first report that up-dip ruptures are more abundant than down-dip ruptures for shallow subduction interface earthquakes, which can be understood as a consequence of the material contrast between the slab and the overriding crust. Rupture velocities, which are searched without any a-priori up to the maximal P wave velocity (6000-8000 m/s), are found between 1200 m/s and 4500 m/s. This observation indicates that no earthquakes propagate over long distances with rupture velocity approaching the P wave velocity. Among the 23 ruptures faster than 3100 m/s, we observe both documented supershear ruptures (e.g. the 2001 Kunlun earthquake), and undocumented ruptures that very likely include a supershear phase. We also find that the correlation of Vr with the source duration scaled to the seismic moment (Ts) is very weak. This directly implies that both Ts and Vr are anticorrelated with the stress drop Δσ. This result has implications for the assessment of the peak ground acceleration (PGA) variability. As shown by Causse and Song (2015), an anticorrelation between Δσ and Vr significantly reduces the predicted PGA variability, and brings it closer to the observed variability.

Long-Period Ground Motion due to Near-Shear Earthquake Ruptures

NASA Astrophysics Data System (ADS)

Koketsu, K.; Yokota, Y.; Hikima, K.

2010-12-01

Long-period ground motion has become an increasingly important consideration because of the recent rapid increase in the number of large-scale structures, such as high-rise buildings and large oil storage tanks. Large subduction-zone earthquakes and moderate to large crustal earthquakes can generate far-source long-period ground motions in distant sedimentary basins with the help of path effects. Near-fault long-period ground motions are generated, for the most part, by the source effects of forward rupture directivity (Koketsu and Miyake, 2008). This rupture directivity effect is the maximum in the direction of fault rupture when a rupture velocity is nearly equal to shear wave velocity around a source fault (Dunham and Archuleta, 2005). The near-shear rupture was found to occur during the 2008 Mw 7.9 Wenchuan earthquake at the eastern edge of the Tibetan plateau (Koketsu et al., 2010). The variance of waveform residuals in a joint inversion of teleseismic and strong motion data was the minimum when we adopted a rupture velocity of 2.8 km/s, which is close to the shear wave velocity of 2.6 km/s around the hypocenter. We also found near-shear rupture during the 2010 Mw 6.9 Yushu earthquake (Yokota et al., 2010). The optimum rupture velocity for an inversion of teleseismic data is 3.5 km/s, which is almost equal to the shear wave velocity around the hypocenter. Since, in addition, supershear rupture was found during the 2001 Mw 7.8 Central Kunlun earthquake (Bouchon and Vallee, 2003), such fast earthquake rupture can be a characteristic of the eastern Tibetan plateau. Huge damage in Yingxiu and Beichuan from the 2008 Wenchuan earthquake and damage heavier than expected in the county seat of Yushu from the medium-sized Yushu earthquake can be attributed to the maximum rupture directivity effect in the rupture direction due to near-shear earthquake ruptures.

Retrospective analysis of obstetric and anesthetic management of patients with placenta accreta spectrum disorders.

PubMed

Riveros-Perez, Efrain; Wood, Cristina

2018-03-01

To assess the management and maternal outcomes of placenta accreta spectrum (PAS) disorders. A retrospective chart review was conducted of patients diagnosed with PAS disorders (placenta creta, increta, or percreta) who were treated at a US tertiary care center between February 1, 2011, and January 31, 2016. Obstetric management, anesthetic management, and maternal outcomes were analyzed. A total of 43 cases were identified; placenta previa was diagnosed among 33 (77%). Median age was 33 years (range 23-42). Median blood loss was 1500 mL (interquartile range 1000-2500); blood loss was greatest among the 10 patients with placenta percreta (3250 mL, interquartile range 2200-6000). Transfusion of blood products was necessary among 14 (33%) patients, with no difference in frequency according to the degree of placental invasion (P=0.107). Surgical complications occurred among 10 (23%) patients. Overall, 30 (70%) patients received combined spinal-epidural plus general anesthesia, 4 (9%) received only general anesthesia, and 9 (21%) underwent surgery with combined spinal-epidural anesthesia. One patient experienced difficult airway and another experienced accidental dural puncture. Placenta previa and accreta coexist in many patients, leading to substantial bleeding related to the degree of myometrial invasion. An interdisciplinary team approach plus the use of combined spinal-epidural anesthesia, transitioning to general anesthesia, were advisable and safe. © 2017 International Federation of Gynecology and Obstetrics.

Assessment of total placenta previa by magnetic resonance imaging and ultrasonography to detect placenta accreta and its variants.

PubMed

Peker, Nuri; Turan, Volkan; Ergenoglu, Mete; Yeniel, Ozgur; Sever, Ahmet; Kazandi, Mert; Zekioglu, Osman

2013-03-01

To evaluate the importance of ultrasonography (US) and magnetic resonance imaging (MRI) in detecting placental adherence defects. Patients diagnozed with total placenta previa (n = 40) in whom hysterectomy was performed due to placental adherence defects (n = 20) or in whom the placenta detached spontaneously after a Cesarean delivery (n = 20) were included into the study between June 2008 and January 2011, at the Department of Obstetrics and Gynecology Ege University (lzmir Turkey). Gray-scale US was used to check for any placental lacunae, sub-placental sonolucent spaces or a placental mass invading the vesicouterine plane and bladder Intra-placental lacunar turbulent blood flow and an increase in vascularization in the vesicouterine plane were evaluated with color Doppler mode. Subsequently all patients had MRI and the results were compared with the histopathologic examinations. The sensitivity of MRI for diagnosis of placental adherence defects before the operation was 95%, with a specificity of 95%. In the presence of at least one diagnostic criterion, the sensitivity and specificity of US were 87.5% and 100% respectively, while the sensitivity of color Doppler US was 62.5% with a specificity of 100%. Currently MRI appears to be the gold standard for the diagnosis of placenta accreta. None of the ultrasonographic criteria is solely sufficient to diagnose placental adherence defects, however they assist in the diagnostic process.

Discussion on the Timing of Balloon Occlusion of the Abdominal Aorta during a Caesarean Section in Patients with Pernicious Placenta Previa Complicated with Placenta Accreta

PubMed Central

Yang, Kaili; Cai, Lina

2017-01-01

Objective This paper is aimed at investigating the role and value of the timing of balloon occlusion of the abdominal aorta during caesarean section in patients with pernicious placenta previa complicated with placenta accreta. Methods 79 cases admitted to the Second Affiliated Hospital of Zhengzhou University from September 2015 to December 2016 were treated with ultrasound mediated abdominal aortic balloon occlusion. Among them, 42 cases, whose balloon occlusion time was selected before the delivery and transverse incision was taken, were group A. The other 37 cases were group B, whose timing of balloon occlusion was selected after the delivery and the uterine incision made trying to avoid the placenta or double incisions. The intraoperative blood loss, utilization of blood, and other indicators were compared between the two groups. Results The intraoperative blood loss in groups A and B was 413.8 ± 105.9 ml and 810.3 ± 180.3 ml, and the utilization of blood products in groups A and B was 30.23% and 89.2%. The total hysterectomy rate was 2.53% (2/79), with no hysterectomies in groups A and 2 cases in group B. Conclusion The balloon occlusion of the abdominal aorta before the delivery combined with a transverse incision is more effective. PMID:29230417

Open versus endovascular repair of ruptured abdominal aortic aneurysms: What have we learned after more than 2 decades of ruptured endovascular aneurysm repair?

PubMed

Robinson, William P

2017-12-01

Ruptured abdominal aortic aneurysm is one of the most difficult clinical problems in surgical practice, with extraordinarily high morbidity and mortality. During the past 23 years, the literature has become replete with reports regarding ruptured endovascular aneurysm repair. A variety of study designs and databases have been utilized to compare ruptured endovascular aneurysm repair and open surgical repair for ruptured abdominal aortic aneurysm and studies of various designs from different databases have yielded vastly different conclusions. It therefore remains controversial whether ruptured endovascular aneurysm repair improves outcomes after ruptured abdominal aortic aneurysm in comparison to open surgical repair. The purpose of this article is to review the best available evidence comparing ruptured endovascular aneurysm repair and open surgical repair of ruptured abdominal aortic aneurysm, including single institution and multi-institutional retrospective observational studies, large national population-based studies, large national registries of prospectively collected data, and randomized controlled clinical trials. This article will analyze the study designs and databases utilized with their attendant strengths and weaknesses to understand the sometimes vastly different conclusions the studies have reached. This article will attempt to integrate the data to distill some of the lessons that have been learned regarding ruptured endovascular aneurysm repair and identify ongoing needs in this field. Copyright © 2017 Elsevier Inc. All rights reserved.

Aneurysm Morphology and Prediction of Rupture: An International Study of Unruptured Intracranial Aneurysms Analysis.

PubMed

Mocco, J; Brown, Robert D; Torner, James C; Capuano, Ana W; Fargen, Kyle M; Raghavan, Madhavan L; Piepgras, David G; Meissner, Irene; Huston, John

2018-04-01

There are conflicting data between natural history studies suggesting a very low risk of rupture for small, unruptured intracranial aneurysms and retrospective studies that have identified a much higher frequency of small, ruptured aneurysms than expected. To use the prospective International Study of Unruptured Intracranial Aneurysms cohort to identify morphological characteristics predictive of unruptured intracranial aneurysm rupture. A case-control design was used to analyze morphological characteristics associated with aneurysm rupture in the International Study of Unruptured Intracranial Aneurysms database. Fifty-seven patients with ruptured aneurysms during follow-up were matched (by size and location) with 198 patients with unruptured intracranial aneurysms without rupture during follow-up. Twelve morphological metrics were measured from cerebral angiograms in a blinded fashion. Perpendicular height (P = .008) and size ratio (ratio of maximum diameter to the parent vessel diameter; P = .01) were predictors of aneurysm rupture on univariate analysis. Aspect ratio, daughter sacs, multiple lobes, aneurysm angle, neck diameter, parent vessel diameter, and calculated aneurysm volume were not statistically significant predictors of rupture. On multivariate analysis, perpendicular height was the only significant predictor of rupture (Chi-square 7.1, P-value .008). This study underscores the importance of other morphological factors, such as perpendicular height and size ratio, that may influence unruptured intracranial aneurysm rupture risk in addition to greatest diameter and anterior vs posterior location.

Real-Time Detection of Rupture Development: Earthquake Early Warning Using P Waves From Growing Ruptures

NASA Astrophysics Data System (ADS)

Kodera, Yuki

2018-01-01

Large earthquakes with long rupture durations emit P wave energy throughout the rupture period. Incorporating late-onset P waves into earthquake early warning (EEW) algorithms could contribute to robust predictions of strong ground motion. Here I describe a technique to detect in real time P waves from growing ruptures to improve the timeliness of an EEW algorithm based on seismic wavefield estimation. The proposed P wave detector, which employs a simple polarization analysis, successfully detected P waves from strong motion generation areas of the 2011 Mw 9.0 Tohoku-oki earthquake rupture. An analysis using 23 large (M ≥ 7) events from Japan confirmed that seismic intensity predictions based on the P wave detector significantly increased lead times without appreciably decreasing the prediction accuracy. P waves from growing ruptures, being one of the fastest carriers of information on ongoing rupture development, have the potential to improve the performance of EEW systems.

Resolution of alliance ruptures: The special case of animal-assisted psychotherapy.

PubMed

Zilcha-Mano, Sigal

2017-01-01

Many therapists regard alliance ruptures as one of the greatest challenges therapists face in the therapy room. Alliance ruptures has been previously defined as breakdowns in the process of negotiation of treatment tasks and goals and a deterioration in the affective bond between patient and therapist. Alliance ruptures have been found to predict premature termination of treatment and poor treatment outcomes. But ruptures can also present important opportunities for gaining insight and awareness and for facilitating therapeutic change. A process of rupture resolution may lead to beneficial outcomes and serve as a corrective emotional experience. The article describes unique processes of alliance rupture resolution inherent in animal-assisted psychotherapy (AAP). Building on Safran and Muran's model and on clinical examples, the article describes strategies for identifying ruptures in AAP and techniques for repairing them to facilitate a corrective experience in treatment. Implications for clinical practice and future research are discussed.

Diagnosis and management of testicular rupture after blunt scrotal trauma: a literature review.

PubMed

Wang, Zhao; Yang, Jin-Rui; Huang, Yu-Meng; Wang, Long; Liu, Long-Fei; Wei, Yong-Bao; Huang, Liang; Zhu, Quan; Zeng, Ming-Qiang; Tang, Zheng-Yan

2016-12-01

Testicular rupture, one of the most common complications in blunt scrotal trauma, is the rupture of tunica albuginea and extrusion of seminiferous tubules. Testicular rupture is more inclined to young men, and injury mechanisms are associated with sports and motor accidents. After history taking and essential physical examination, scrotal ultrasound is the first-line auxiliary examination. MRI is also one of the vital complementary examinations to evaluate testicular rupture after blunt scrotal trauma. Surgical exploration and repair may be necessary when the diagnosis of testicular rupture is definite or suspicious. Postoperative follow-up is to monitor the relief of local symptoms and changes of testicular functions. This review sums up the literatures about testicular rupture after blunt scrotal trauma in recent 16 years and also refers some new advantages and perspectives on diagnosis and management of testicular rupture.

Ruptured Tendons in Anabolic-Androgenic Steroid Users: A Cross-Sectional Cohort Study.

PubMed

Kanayama, Gen; DeLuca, James; Meehan, William P; Hudson, James I; Isaacs, Stephanie; Baggish, Aaron; Weiner, Rory; Micheli, Lyle; Pope, Harrison G

2015-11-01

Accumulating case reports have described tendon rupture in men who use anabolic-androgenic steroids (AAS). However, no controlled study has assessed the history of tendon rupture in a large cohort of AAS users and comparison nonusers. Men reporting long-term AAS abuse would report an elevated lifetime incidence of tendon rupture compared with non-AAS-using bodybuilders. Cohort study; Level of evidence, 3. Medical histories were obtained from 142 experienced male bodybuilders aged 35 to 55 years recruited in the course of 2 studies. Of these men, 88 reported at least 2 years of cumulative lifetime AAS use, and 54 reported no history of AAS use. In men reporting a history of tendon rupture, the circumstances of the injury, prodromal symptoms, concomitant drug or alcohol use, and details of current and lifetime AAS use (if applicable) were recorded. Surgical records were obtained for most participants. Nineteen (22%) of the AAS users, but only 3 (6%) of the nonusers, reported at least 1 lifetime tendon rupture. The hazard ratio for a first ruptured tendon in AAS users versus nonusers was 9.0 (95% CI, 2.5-32.3; P < .001). Several men reported 2 or more independent lifetime tendon ruptures. Interestingly, upper-body tendon ruptures occurred exclusively in the AAS group (15 [17%] AAS users vs 0 nonusers; risk difference, 0.17 [95% CI, 0.09-0.25]; P < .001 [hazard ratio not estimable]), whereas there was no significant difference between users and nonusers in risk for lower-body ruptures (6 [7%] AAS users, 3 [6%] nonusers; hazard ratio, 3.1 [95% CI, 0.7-13.8]; P = .13). Of 31 individual tendon ruptures assessed, only 6 (19%) occurred while weightlifting, with the majority occurring during other sports activities. Eight (26%) ruptures followed prodromal symptoms of nonspecific pain in the region. Virtually all ruptures were treated surgically, with complete or near-complete ultimate restoration of function. AAS abusers, compared with otherwise similar bodybuilders, showed a markedly increased risk of tendon ruptures, particularly upper-body tendon rupture. © 2015 The Author(s).

A novel strategy to translate the biomechanical rupture risk of abdominal aortic aneurysms to their equivalent diameter risk: method and retrospective validation.

PubMed

Gasser, T C; Nchimi, A; Swedenborg, J; Roy, J; Sakalihasan, N; Böckler, D; Hyhlik-Dürr, A

2014-03-01

To translate the individual abdominal aortic aneurysm (AAA) patient's biomechanical rupture risk profile to risk-equivalent diameters, and to retrospectively test their predictability in ruptured and non-ruptured aneurysms. Biomechanical parameters of ruptured and non-ruptured AAAs were retrospectively evaluated in a multicenter study. General patient data and high resolution computer tomography angiography (CTA) images from 203 non-ruptured and 40 ruptured aneurysmal infrarenal aortas. Three-dimensional AAA geometries were semi-automatically derived from CTA images. Finite element (FE) models were used to predict peak wall stress (PWS) and peak wall rupture index (PWRI) according to the individual anatomy, gender, blood pressure, intra-luminal thrombus (ILT) morphology, and relative aneurysm expansion. Average PWS diameter and PWRI diameter responses were evaluated, which allowed for the PWS equivalent and PWRI equivalent diameters for any individual aneurysm to be defined. PWS increased linearly and PWRI exponentially with respect to maximum AAA diameter. A size-adjusted analysis showed that PWS equivalent and PWRI equivalent diameters were increased by 7.5 mm (p = .013) and 14.0 mm (p < .001) in ruptured cases when compared to non-ruptured controls, respectively. In non-ruptured cases the PWRI equivalent diameters were increased by 13.2 mm (p < .001) in females when compared with males. Biomechanical parameters like PWS and PWRI allow for a highly individualized analysis by integrating factors that influence the risk of AAA rupture like geometry (degree of asymmetry, ILT morphology, etc.) and patient characteristics (gender, family history, blood pressure, etc.). PWRI and the reported annual risk of rupture increase similarly with the diameter. PWRI equivalent diameter expresses the PWRI through the diameter of the average AAA that has the same PWRI, i.e. is at the same biomechanical risk of rupture. Consequently, PWRI equivalent diameter facilitates a straightforward interpretation of biomechanical analysis and connects to diameter-based guidelines for AAA repair indication. PWRI equivalent diameter reflects an additional diagnostic parameter that may provide more accurate clinical data for AAA repair indication. Copyright © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Great earthquakes of variable magnitude at the Cascadia subduction zone

USGS Publications Warehouse

Nelson, A.R.; Kelsey, H.M.; Witter, R.C.

2006-01-01

Comparison of histories of great earthquakes and accompanying tsunamis at eight coastal sites suggests plate-boundary ruptures of varying length, implying great earthquakes of variable magnitude at the Cascadia subduction zone. Inference of rupture length relies on degree of overlap on radiocarbon age ranges for earthquakes and tsunamis, and relative amounts of coseismic subsidence and heights of tsunamis. Written records of a tsunami in Japan provide the most conclusive evidence for rupture of much of the plate boundary during the earthquake of 26 January 1700. Cascadia stratigraphic evidence dating from about 1600??cal yr B.P., similar to that for the 1700 earthquake, implies a similarly long rupture with substantial subsidence and a high tsunami. Correlations are consistent with other long ruptures about 1350??cal yr B.P., 2500??cal yr B.P., 3400??cal yr B.P., 3800??cal yr B.P., 4400??cal yr B.P., and 4900??cal yr B.P. A rupture about 700-1100??cal yr B.P. was limited to the northern and central parts of the subduction zone, and a northern rupture about 2900??cal yr B.P. may have been similarly limited. Times of probable short ruptures in southern Cascadia include about 1100??cal yr B.P., 1700??cal yr B.P., 3200??cal yr B.P., 4200??cal yr B.P., 4600??cal yr B.P., and 4700??cal yr B.P. Rupture patterns suggest that the plate boundary in northern Cascadia usually breaks in long ruptures during the greatest earthquakes. Ruptures in southernmost Cascadia vary in length and recurrence intervals more than ruptures in northern Cascadia.

Total rupture of hydatid cyst of liver in to common bile duct: a case report.

PubMed

Robleh, Hassan; Yassine, Fahmi; Driss, Khaiz; Khalid, Elhattabi; Fatima-Zahra, Bensardi; Saad, Berrada; Rachid, Lefriyekh; Abdalaziz, Fadil; Najib, Zerouali Ouariti

2014-01-01

Rupture of hydatid liver cyst into biliary tree is frequent complications that involve the common hepatic duct, lobar biliary branches, the small intrahepatic bile ducts,but rarely rupture into common bile duct. The rupture of hydatid cyst is serious life threating event. The authors are reporting a case of total rupture of hydatid cyst of liver into common bile duct. A 50-year-old male patient who presented with acute cholangitis was diagnosed as a case of totally rupture of hydatid cyst on Abdominal CT Scan. Rupture of hydatid cyst of liver into common bile duct and the gallbladder was confirmed on surgery. Treated by cholecystectomy and T-tube drainage of Common bile duct.

Ruptured Tendons in Anabolic-Androgenic Steroid Users: A Cross-Sectional Cohort Study

PubMed Central

Kanayama, Gen; DeLuca, James; Meehan, William P.; Hudson, James I.; Isaacs, Stephanie; Baggish, Aaron; Weiner, Rory; Micheli, Lyle; Pope, Harrison G.

2016-01-01

Background Accumulating case reports have described tendon rupture in men using anabolic-androgenic steroids (AAS). However no controlled study, to our knowledge, has assessed history of tendon rupture in a large cohort of AAS users and comparison nonusers. Hypothesis We hypothesized that men reporting long-term AAS abuse would report an elevated lifetime incidence of tendon rupture as compared to non-AAS-using bodybuilders. Study Design Cross-sectional cohort study. Methods We obtained medical histories from 142 experienced male bodybuilders age 35–55, recruited in the course of two studies. Of these men, 88 reported at least two years of cumulative lifetime AAS use and 54 reported no history of AAS use. In men reporting a history of tendon rupture, we recorded circumstances of the injury, prodromal symptoms, concomitant drug or alcohol use, and details of current and lifetime AAS use if applicable. We also obtained surgical records for most participants. Results Nineteen (22%) of the AAS users, but only 3 (6%) of the nonusers reported at least one lifetime tendon rupture. The hazard ratio (95% confidence interval) for a first ruptured tendon in AAS users versus nonusers was 9.0 (2.5, 32.3); P <.001. Several men reported two or more independent lifetime tendon ruptures. Interestingly, upper body tendon ruptures occurred exclusively in the AAS group (15 [17%] of the AAS users versus 0 non-users; risk difference 0.17 (0.09, 0.25); P < 0.001 [hazard ratio not estimable]), whereas we found no significant difference between users and nonusers in risk for lower body ruptures (6 [7%] AAS users, 3 [6%] nonusers; hazard ratio 3.1 (0.7, 13.8), P = 0.13). Of 31 individual tendon ruptures that we assessed, only 6 (19%) occurred while weightlifting, with the majority occurring during other sports activities. Eight (26%) ruptures followed prodromal symptoms of nonspecific pain in the region. Virtually all ruptures were treated surgically with complete or near-complete ultimate restoration of function. Conclusions AAS abusers, as compared to otherwise similar bodybuilders, showed a markedly increased risk of tendon ruptures, particularly upper body tendon rupture. Clinical relevance Tendon rupture represents a major adverse consequence of AAS abuse and a substantial public health problem. PMID:26362436

Uterine rupture disguised by urinary retention following a second trimester induced abortion: a case report.

PubMed

Jiang, Qiaoying; Yang, Liwei; Ashley, Charles; Medlin, Erin E; Kushner, David M; Zheng, Yanmei

2015-01-22

Uterine rupture classically presents with severe abdominal pain, loss of fetal station, vaginal bleeding, and shock. We present a case of uterine rupture presenting as significant urinary retention that occurred following a second trimester abortion induced with mifepristone and misoprostol. Uterine rupture was discovered unexpectedly on diagnostic laparoscopy. The uterine rupture was contained by dense adhesions between the omentum and bladder with the previous uterine cesarean hysterotomy scar. This case highlights the difficulties in diagnosis of abnormal placentation and an unusual presentation of uterine rupture. This case was managed successfully laparoscopically.

An Analysis of Surgical Treatment for the Spontaneous Rupture of Hepatocellular Carcinoma.

PubMed

Sada, Haruki; Ohira, Masahiro; Kobayashi, Tsuyoshi; Tashiro, Hirotaka; Chayama, Kazuaki; Ohdan, Hideki

2016-01-01

The prognosis of spontaneous rupture of hepatocellular carcinoma (HCC) remains unclear. We investigated the prognosis of patients with ruptured HCC based on the treatments and prognostic factors associated with long-term survival. The prognoses of 64 consecutive patients treated for ruptured HCC from 1986 to 2013 were analyzed according to their methods of treatment. The prognostic factors of 16 surgical patients were identified, and their overall survival (OS) and recurrence rates were compared to 1,157 surgical patients who underwent surgery for non-ruptured HCC. The surgical outcomes were also compared using a propensity score matching method. Surgery was associated with a better OS. Curative resection was the only independent prognostic factor in surgical patients with ruptured HCC (p = 0.040). Although the OS of surgical patients with non-ruptured HCC was found to be significantly better than that of the patients with ruptured HCC, no significant difference in OS was observed after propensity score matching. A curative resection should be the objective of treatment, assuming the suitability of the patient's clinical condition. When the liver function reserve and tumor extension of patients with ruptured and non-ruptured HCC are similar, then their surgical outcomes may not be significantly different. © 2015 S. Karger AG, Basel.

Risk factors affecting chronic rupture of the plantar fascia.

PubMed

Lee, Ho Seong; Choi, Young Rak; Kim, Sang Woo; Lee, Jin Yong; Seo, Jeong Ho; Jeong, Jae Jung

2014-03-01

Prior to 1994, plantar fascia ruptures were considered as an acute injury that occurred primarily in athletes. However, plantar fascia ruptures have recently been reported in the setting of preexisting plantar fasciitis. We analyzed risk factors causing plantar fascia rupture in the presence of preexisting plantar fasciitis. We retrospectively reviewed 286 patients with plantar fasciitis who were referred from private clinics between March 2004 and February 2008. Patients were divided into those with or without a plantar fascia rupture. There were 35 patients in the rupture group and 251 in the nonrupture group. The clinical characteristics and risk factors for plantar fascia rupture were compared between the 2 groups. We compared age, gender, the affected site, visual analog scale pain score, previous treatment regimen, body mass index, degree of ankle dorsiflexion, the use of steroid injections, the extent of activity, calcaneal pitch angle, the presence of a calcaneal spur, and heel alignment between the 2 groups. Of the assessed risk factors, only steroid injection was associated with the occurrence of a plantar fascia rupture. Among the 35 patients with a rupture, 33 had received steroid injections. The odds ratio of steroid injection was 33. Steroid injections for plantar fasciitis should be cautiously administered because of the higher risk for plantar fascia rupture. Level III, retrospective comparative study.

Primary surface rupture associated with the Mw 7.1 16 October 1999 Hector Mine earthquake, San Bernardino County, California

USGS Publications Warehouse

Treiman, J.A.; Kendrick, K.J.; Bryant, W.A.; Rockwell, T.K.; McGill, S.F.

2002-01-01

The Mw 7.1 Hector Mine earthquake occurred within the Mojave Desert portion of the eastern California shear zone and was accompanied by 48 km of dextral surface rupture. Complex northward rupture began on two branches of the Lavic Lake fault in the northern Bullion Mountains and also propagated southward onto the Bullion fault. Lesser amounts of rupture occurred across two right steps to the south. Surface rupture was mapped using postearthquake, 1:10,000-scale aerial photography. Field mapping provided additional detail and more than 400 fault-rupture observations; of these, approximately 300 measurements were used to characterize the slip distribution. En echelon surface rupture predominated in areas of thick alluvium, whereas in the bedrock areas, rupture was more continuous and focused within a narrower zone. Measured dextral offsets were relatively symmetrical about the epicentral region, with a maximum displacement of 5.25 ?? 0.85 m. Vertical slip was a secondary component and was variable, with minor west-side-down displacements predominat.ing in the Bullion Mountains. Field and aerial photographic evidence indicates that most of the faults that ruptured in 1999 had had prior late-Quaternary displacement, although only limited sections of the rupture show evidence for prior Holocene displacement.

Imprint of Rupture Directivity From Ground Motions of the 24 August 2016 Mw6.2 Central Italy Earthquake

NASA Astrophysics Data System (ADS)

Ren, Yefei; Wang, Hongwei; Wen, Ruizhi

2017-12-01

An Mw6.2 earthquake occurred in Central Italy on 24 August 2016. The objective of this study was to reveal the imprint of rupture directivity using the strong motion recordings. The strong motion stations were separated into two groups: southeast (SE) and northwest (NW). The effects of rupture directivity on the peak ground acceleration (PGA), peak ground velocity (PGV), and pseudo spectral acceleration (PSA) were investigated. The observed values of these parameters were compared with predicted values derived from ground motion prediction equations. The results showed that the residuals between the observed and predicted PGAs, PGVs, and PSAs at periods of T < 1 s were correlated significantly with azimuth angle and generally larger in the NW sector, reflecting that the observed PGAs, PGVs, and short-period PSAs in the NW sector were generally larger than observed in the SE sector. These phenomena are accordant with the theoretical law that the rupture directivity causes higher amplitudes in the forward direction compared with the backward direction. Finally, selected source rupture parameters were inverted using PGAs and PGVs. This revealed that the rupture was predominantly unilateral rupture, the major rupture was likely at an azimuth of 360°, and the length of the major rupture was proportional to 70%-100% of the total ruptured fault, confirming that rupture directivity caused the differences in the ground motions observed in the SE and NW sectors.

Interfacial thin films rupture and self-similarity

NASA Astrophysics Data System (ADS)

Ward, Margaret H.

2011-06-01

Two superposed thin layers of fluids are prone to interfacial instabilities due to London-van der Waals forces. Evolution equations for the film thicknesses are derived using lubrication theory. Using the intrinsic scales, for a single layer, results in a system with parametric dependence of four ratios of the two layers: surface tension, Hamaker constant, viscosity, and film thickness. In contrast to the single layer case, the bilayer system has two unstable eigenmodes: squeezing and bending. For some particular parameter regimes, the system exhibits the avoided crossing behavior, where the two eigenmodes are interchanged. Based on numerical analysis, the system evolves into four different rupture states: basal layer rupture, upper layer rupture, double layer rupture, and mixed layer rupture. The ratio of Hamaker constants and the relative film thickness of the two layers control the system dynamics. Remarkably, the line of avoided crossing demarks the transition region of mode mixing and energy transfer, affecting the scaling of the dynamical regime map consequentially. Asymptotic and numerical analyses are used to examine the self-similar ruptures and to extract the power law scalings for both the basal layer rupture and the upper layer rupture. The scaling laws for the basal layer rupture are the same as those of the single layer on top of a substrate. The scaling laws for the upper layer rupture are different: the lateral length scale decreases according to (tr-t)1/3 and the film thickness decreases according to (tr-t)1/6.

Blood flow characteristics in a terminal basilar tip aneurysm prior to its fatal rupture

PubMed Central

Sforza, D.M.; Putman, C.M.; Scrivano, E.; Lylyk, P.; Cebral, J.R.

2010-01-01

Background and Purpose The development and validation of methods to stratify the risk of rupture of cerebral aneurysms is highly desired since current treatment risks can exceed the natural risk of rupture. Because unruptured aneurysms are typically treated before they rupture, it is very difficult to connect the proposed risk indices to the rupture of an individual aneurysm. The purpose of this case study was to analyze the hemodynamic environment of a saccular aneurysm of the terminal morphology sub-type that was imaged just prior to its rupture and to test whether the hemodynamic characteristics would designate this particular aneurysm as at high risk. Methods A patient-specific computational fluid dynamics model was constructed from 3D rotational angiography images acquired just hours before the aneurysm ruptured. A pulsatile flow calculation was performed and hemodynamic characteristics previously connected to rupture were analyzed. Results It was found that the aneurysm had a concentrated inflow stream, small impingement region, complex intra-aneurysmal flow structure, asymmetric flow split from the parent vessel to the aneurysm and daughter branches, and high levels of aneurysmal wall shear stress near the impaction zone. Conclusions The hemodynamics characteristics observed in this aneurysm right before its rupture are consistent with previous studies correlating aneurysm rupture and hemodynamic patterns in saccular and terminal aneurysms. This study supports the notion that hemodynamic information may be used to help stratify the rupture risk of cerebral aneurysms. PMID:20150312

Injuries of the trachea and bronchi

PubMed Central

Bertelsen, S.; Howitz, P.

1972-01-01

Traumatic rupture of the trachea or the bronchi is reported with increasing frequency. Such rupture may follow penetrating wounds, but the common cause is blunt trauma of the throat or thorax. When the proximal trachea is damaged other cervical structures are usually involved. By contrast the distal trachea or bronchi are not infrequently the only thoracic structures damaged. In particular there may be no rib fractures, or obvious fractures may be uncomplicated and insignificant. Thoracic rupture usually occurs in the vicinity of the carina. Central rupture generally presents with emphysema of the mediastinum and neck. Diagnosis can usually be confirmed by tracheobronchoscopy. Rupture of the peripheral bronchi generally presents with pneumothorax and atelectasis. Central rupture should be treated by primary suture. Lobectomy is often necessary when small bronchi are ruptured. PMID:5034596

Induced seismicity provides insight into why earthquake ruptures stop.

PubMed

Galis, Martin; Ampuero, Jean Paul; Mai, P Martin; Cappa, Frédéric

2017-12-01

Injection-induced earthquakes pose a serious seismic hazard but also offer an opportunity to gain insight into earthquake physics. Currently used models relating the maximum magnitude of injection-induced earthquakes to injection parameters do not incorporate rupture physics. We develop theoretical estimates, validated by simulations, of the size of ruptures induced by localized pore-pressure perturbations and propagating on prestressed faults. Our model accounts for ruptures growing beyond the perturbed area and distinguishes self-arrested from runaway ruptures. We develop a theoretical scaling relation between the largest magnitude of self-arrested earthquakes and the injected volume and find it consistent with observed maximum magnitudes of injection-induced earthquakes over a broad range of injected volumes, suggesting that, although runaway ruptures are possible, most injection-induced events so far have been self-arrested ruptures.

Genome-wide association analysis in dogs implicates 99 loci as risk variants for anterior cruciate ligament rupture

PubMed Central

Baker, Lauren A.; Kirkpatrick, Brian; Rosa, Guilherme J. M.; Gianola, Daniel; Valente, Bruno; Sumner, Julia P.; Baltzer, Wendy; Hao, Zhengling; Binversie, Emily E.; Volstad, Nicola; Piazza, Alexander; Sample, Susannah J.

2017-01-01

Anterior cruciate ligament (ACL) rupture is a common condition that can be devastating and life changing, particularly in young adults. A non-contact mechanism is typical. Second ACL ruptures through rupture of the contralateral ACL or rupture of a graft repair is also common. Risk of rupture is increased in females. ACL rupture is also common in dogs. Disease prevalence exceeds 5% in several dog breeds, ~100 fold higher than human beings. We provide insight into the genetic etiology of ACL rupture by genome-wide association study (GWAS) in a high-risk breed using 98 case and 139 control Labrador Retrievers. We identified 129 single nucleotide polymorphisms (SNPs) within 99 risk loci. Associated loci (P<5E-04) explained approximately half of phenotypic variance in the ACL rupture trait. Two of these loci were located in uncharacterized or non-coding regions of the genome. A chromosome 24 locus containing nine genes with diverse functions met genome-wide significance (P = 3.63E-0.6). GWAS pathways were enriched for c-type lectins, a gene set that includes aggrecan, a gene set encoding antimicrobial proteins, and a gene set encoding membrane transport proteins with a variety of physiological functions. Genotypic risk estimated for each dog based on the risk contributed by each GWAS locus showed clear separation of ACL rupture cases and controls. Power analysis of the GWAS data set estimated that ~172 loci explain the genetic contribution to ACL rupture in the Labrador Retriever. Heritability was estimated at 0.48. We conclude ACL rupture is a moderately heritable highly polygenic complex trait. Our results implicate c-type lectin pathways in ACL homeostasis. PMID:28379989

Spontaneous rupture of ovarian cystadenocarcinoma: pre- and post-rupture computed tomography evaluation*

PubMed Central

Salvadori, Priscila Silveira; Bomfim, Lucas Novais; von Atzingen, Augusto Castelli; D’Ippolito, Giuseppe

2015-01-01

Epithelial ovarian tumors are the most common malignant ovarian neoplasms and, in most cases, eventual rupture of such tumors is associated with a surgical procedure. The authors report the case of a 54-year-old woman who presented with spontaneous rupture of ovarian cystadenocarcinoma documented by computed tomography, both before and after the event. In such cases, a post-rupture staging tends to be less favorable, compromising the prognosis. PMID:26543286

Kinetics of the Multistep Rupture of Fibrin ‘A-a’ Polymerization Interactions Measured Using Atomic Force Microscopy

PubMed Central

Averett, Laurel E.; Schoenfisch, Mark H.; Akhremitchev, Boris B.; Gorkun, Oleg V.

2009-01-01

Abstract Fibrin, the structural scaffold of blood clots, spontaneously polymerizes through the formation of ‘A-a’ knob-hole bonds. When subjected to external force, the dissociation of this bond is accompanied by two to four abrupt changes in molecular dimension observable as rupture events in a force curve. Herein, the configuration, molecular extension, and kinetic parameters of each rupture event are examined. The increases in contour length indicate that the D region of fibrinogen can lengthen by ∼50% of the length of a fibrin monomer before rupture of the ‘A-a’ interaction. The dependence of the dissociation rate on applied force was obtained using probability distributions of rupture forces collected at different pull-off velocities. These distributions were fit using a model in which the effects of the shape of the binding potential are used to quantify the kinetic parameters of forced dissociation. We found that the weak initial rupture (i.e., event 1) was not well approximated by these models. The ruptured bonds comprising the strongest ruptures, events 2 and 3, had kinetic parameters similar to those commonly found for the mechanical unfolding of globular proteins. The bonds ruptured in event 4 were well described by these analyses, but were more loosely bound than the bonds in events 2 and 3. We propose that the first event represents the rupture of an unknown interaction parallel to the ‘A-a’ bond, events 2 and 3 represent unfolding of structures in the D region of fibrinogen, and event 4 is the rupture of the ‘A-a’ knob-hole bond weakened by prior structural unfolding. Comparison of the activation energy obtained via force spectroscopy measurements with the thermodynamic free energy of ‘A-a’ bond dissociation indicates that the ‘A-a’ bond may be more resistant to rupture by applied force than to rupture by thermal dissociation. PMID:19917237

Definitive diagnosis of breast implant rupture using magnetic resonance imaging.

PubMed

Ahn, C Y; Shaw, W W; Narayanan, K; Gorczyca, D P; Sinha, S; Debruhl, N D; Bassett, L W

1993-09-01

Breast implant rupture is an important complication of augmented and reconstructed breasts. Although several techniques such as mammography, xeromammography, ultrasound, thermography, and computed tomographic (CT) scanning have been proven to be useful to detect implant rupture, they have several disadvantages and lack specificity. In the current study, we have established magnetic resonance imaging (MRI) as a definitive, reliable, and reproducible technique to diagnose both intracapsular and extracapsular ruptures. The study was conducted in 100 symptomatic patients. Our imaging parameters were able to identify ruptures in implants with silicone shells. All the ruptures showed the presence of wavy lines, free-floating silicone shell within the gel ("free-floating loose-thread sign" or "linguine sign"). We had a 3.75 percent incidence of false-positive and false-negative results. The sensitivity for detection of silicone implant rupture was 76 percent, with a specificity of 97 percent. In addition, we also were able to identify the artifacts that may interfere with the definitive diagnosis of implant rupture.

Comparing slow and fast rupture in laboratory experiments

NASA Astrophysics Data System (ADS)

Aben, F. M.; Brantut, N.; David, E.; Mitchell, T. M.

2017-12-01

During the brittle failure of rock, elastically stored energy is converted into a localized fracture plane and surrounding fracture damage, seismic radiation, and thermal energy. However, the partitioning of energy might vary with the rate of elastic energy release during failure. Here, we present the results of controlled (slow) and dynamic (fast) rupture experiments on dry Lanhélin granite and Westerly granite samples, performed under triaxial stress conditions at confining pressures of 50 and 100 MPa. During the tests, we measured sample shortening, axial load and local strains (with 2 pairs of strain gauges glued directly onto the sample). In addition, acoustic emissions (AEs) and changes in seismic velocities were monitored. The AE rate was used as an indicator to manually control the axial load on the sample to stabilize rupture in the quasi-static failure experiments. For the dynamic rupture experiments a constant strain rate of 10-5 s-1 was applied until sample failure. A third experiment, labeled semi-controlled rupture, involved controlled rupture up to a point where the rupture became unstable and the remaining elastic energy was released dynamically. All experiments were concluded after a macroscopic fracture had developed across the whole sample and frictional sliding commenced. Post-mortem samples were epoxied, cut and polished to reveal the macroscopic fracture and the surrounding damage zone. The samples failed with average rupture velocities varying from 5x10-6 m/s up to >> 0.1 m/s. The analyses of AE locations on the slow ruptures reveal that within Westerly granite samples - with a smaller grain size - fracture planes are disbanded in favor of other planes when a geometrical irregularity is encountered. For the coarser grained Lanhélin granite a single fracture plane is always formed, although irregularities are recognized as well. The semi-controlled experiments show that for both rock types the rupture can become unstable in response to these irregularities. In Westerly granite, slow rupture experiments tend to produce complex fracture patterns while during the dynamic rupture experiments secondary rupture planes are not formed. These findings show that grain or flaw size, flaw distribution, and rupture speed strongly influence fracture localization and propagation.

Simultaneous bilateral Achilles tendon ruptures associated with statin medication despite regular rock climbing exercise.

PubMed

Carmont, Michael R; Highland, Adrian M; Blundell, Christopher M; Davies, Mark B

2009-11-01

Ruptures of the Achilles tendon are common however simultaneous ruptures occur less frequently. Eccentric loading exercise programmes have been used to successfully treat Achilles tendinopathy. We report a case of simultaneous bilateral Achilles tendon rupture in a patient predisposed to rupture due to longstanding raised serum lipoprotein and recently introduced therapeutic statin medication. The patient was also a keen rock climber and had regularly undertaken loading exercise. This case illustrates that the therapeutic effect of mixed loading exercises for the Achilles tendon may not be adequate to overcome the predisposition to rupture caused by hyperlipidaemia and statin medication.

Fractal avalanche ruptures in biological membranes

NASA Astrophysics Data System (ADS)

Gözen, Irep; Dommersnes, Paul; Czolkos, Ilja; Jesorka, Aldo; Lobovkina, Tatsiana; Orwar, Owe

2010-11-01

Bilayer membranes envelope cells as well as organelles, and constitute the most ubiquitous biological material found in all branches of the phylogenetic tree. Cell membrane rupture is an important biological process, and substantial rupture rates are found in skeletal and cardiac muscle cells under a mechanical load. Rupture can also be induced by processes such as cell death, and active cell membrane repair mechanisms are essential to preserve cell integrity. Pore formation in cell membranes is also at the heart of many biomedical applications such as in drug, gene and short interfering RNA delivery. Membrane rupture dynamics has been studied in bilayer vesicles under tensile stress, which consistently produce circular pores. We observed very different rupture mechanics in bilayer membranes spreading on solid supports: in one instance fingering instabilities were seen resulting in floral-like pores and in another, the rupture proceeded in a series of rapid avalanches causing fractal membrane fragmentation. The intermittent character of rupture evolution and the broad distribution in avalanche sizes is consistent with crackling-noise dynamics. Such noisy dynamics appear in fracture of solid disordered materials, in dislocation avalanches in plastic deformations and domain wall magnetization avalanches. We also observed similar fractal rupture mechanics in spreading cell membranes.

[Spontaneous splenic rupture due to infectious acute mononucleosis: case report].

PubMed

Greco, L; De Gennaro, E; Degara, A; Papa, U

2003-01-01

Infectious mononucleosis is an acute, viral, illness associated with a high incidence of splenomegaly. Spontaneous splenic rupture is a rare but life-threatening complication of infectious mononucleosis. The authors report the case of a 19-year-old patient with an infectious mononucleosis causing a spontaneous splenic rupture. When rupture occurs the mortality has been significant. The spleen may be vulnerable for the histopathologic changes that occur as a result of this illness. Two thirds of patients with infectious mononucleosis develop an enlarged spleen, but in only 0.5% of all patients will it rupture. Abdominal pain and tachycardia are unusual in uncomplicated infectious mononucleosis and should alert a doctor to the possibility of spontaneous splenic rupture. The diagnosis of splenic rupture may be confirmed in a variety of ways. In this patient ultrasound and Rutkow's criteria may aid in establishing the diagnosis. In patients with infectious mononucleosis suspected of having rupture of the spleen, a rapid but thorough assessment and prompt implementation of appropriate management should minimize the associated morbidity and mortality. On the basis of review of the medical literature and of our own experience, we advocate emergent splenectomy for spontaneous splenic rupture in patients with infectious mononucleosis.

Morphological and Hemodynamic Discriminators for Rupture Status in Posterior Communicating Artery Aneurysms

PubMed Central

Karmonik, Christof; Fang, Yibin; Xu, Jinyu; Yu, Ying; Cao, Wei; Liu, Jianmin; Huang, Qinghai

2016-01-01

Background and Purpose The conflicting findings of previous morphological and hemodynamic studies on intracranial aneurysm rupture may be caused by the relatively small sample sizes and the variation in location of the patient-specific aneurysm models. We aimed to determine the discriminators for aneurysm rupture status by focusing on only posterior communicating artery (PCoA) aneurysms. Materials and Methods In 129 PCoA aneurysms (85 ruptured, 44 unruptured), clinical, morphological and hemodynamic characteristics were compared between the ruptured and unruptured cases. Multivariate logistic regression analysis was performed to determine the discriminators for rupture status of PCoA aneurysms. Results While univariate analyses showed that the size of aneurysm dome, aspect ratio (AR), size ratio (SR), dome-to-neck ratio (DN), inflow angle (IA), normalized wall shear stress (NWSS) and percentage of low wall shear stress area (LSA) were significantly associated with PCoA aneurysm rupture status. With multivariate analyses, significance was only retained for higher IA (OR = 1.539, p < 0.001) and LSA (OR = 1.393, p = 0.041). Conclusions Hemodynamics and morphology were related to rupture status of intracranial aneurysms. Higher IA and LSA were identified as discriminators for rupture status of PCoA aneurysms. PMID:26910518

Morphological and Hemodynamic Discriminators for Rupture Status in Posterior Communicating Artery Aneurysms.

PubMed

Lv, Nan; Wang, Chi; Karmonik, Christof; Fang, Yibin; Xu, Jinyu; Yu, Ying; Cao, Wei; Liu, Jianmin; Huang, Qinghai

2016-01-01

The conflicting findings of previous morphological and hemodynamic studies on intracranial aneurysm rupture may be caused by the relatively small sample sizes and the variation in location of the patient-specific aneurysm models. We aimed to determine the discriminators for aneurysm rupture status by focusing on only posterior communicating artery (PCoA) aneurysms. In 129 PCoA aneurysms (85 ruptured, 44 unruptured), clinical, morphological and hemodynamic characteristics were compared between the ruptured and unruptured cases. Multivariate logistic regression analysis was performed to determine the discriminators for rupture status of PCoA aneurysms. While univariate analyses showed that the size of aneurysm dome, aspect ratio (AR), size ratio (SR), dome-to-neck ratio (DN), inflow angle (IA), normalized wall shear stress (NWSS) and percentage of low wall shear stress area (LSA) were significantly associated with PCoA aneurysm rupture status. With multivariate analyses, significance was only retained for higher IA (OR = 1.539, p < 0.001) and LSA (OR = 1.393, p = 0.041). Hemodynamics and morphology were related to rupture status of intracranial aneurysms. Higher IA and LSA were identified as discriminators for rupture status of PCoA aneurysms.

Systematic Observations of the Slip-pulse Properties of Large Earthquake Ruptures

NASA Astrophysics Data System (ADS)

Melgar, D.; Hayes, G. P.

2017-12-01

In earthquake dynamics there are two end member models of rupture: propagating cracks and self-healing pulses. These arise due to different properties of ruptures and have implications for seismic hazard; rupture mode controls near-field strong ground motions. Past studies favor the pulse-like mode of rupture, however, due to a variety of limitations, it has proven difficult to systematically establish their kinematic properties. Here we synthesize observations from a database of >150 rupture models of earthquakes spanning M7-M9 processed in a uniform manner and show the magnitude scaling properties (rise time, pulse width, and peak slip rate) of these slip pulses indicates self-similarity. Self similarity suggests a weak form of rupture determinism, where early on in the source process broader, higher amplitude slip pulses will distinguish between events of icnreasing magnitude. Indeed, we find by analyzing the moment rate functions that large and very large events are statistically distinguishable relatively early (at 15 seconds) in the rupture process. This suggests that with dense regional geophysical networks strong ground motions from a large rupture can be identified before their onset across the source region.

Influence of fault steps on rupture termination of strike-slip earthquake faults

NASA Astrophysics Data System (ADS)

Li, Zhengfang; Zhou, Bengang

2018-03-01

A statistical analysis was completed on the rupture data of 29 historical strike-slip earthquakes across the world. The purpose of this study is to examine the effects of fault steps on the rupture termination of these events. The results show good correlations between the type and length of steps with the seismic rupture and a poor correlation between the step number and seismic rupture. For different magnitude intervals, the smallest widths of the fault steps (Lt) that can terminate the rupture propagation are variable: Lt = 3 km for Ms 6.5 6.9, Lt = 4 km for Ms 7.0 7.5, Lt = 6 km for Ms 7.5 8.0, and Lt = 8 km for Ms 8.0 8.5. The dilational fault step is easier to rupture through than the compression fault step. The smallest widths of the fault step for the rupture arrest can be used as an indicator to judge the scale of the rupture termination of seismic faults. This is helpful for research on fault segmentation, as well as estimating the magnitude of potential earthquakes, and is thus of significance for the assessment of seismic risks.

Rupture directivity of microseismic events recorded during hydraulic fracture stimulations.

NASA Astrophysics Data System (ADS)

Urbancic, T.; Smith-Boughner, L.; Baig, A.; Viegas, G.

2016-12-01

We model the dynamics of a complex rupture sequence with four sub-events. These events were recorded during hydraulic fracture stimulations in a gas-bearing shale formation. With force-balance accelerometers, 4.5Hz and 15Hz instruments recording the failure history, we study the directivity of the entire rupture sequence and each sub-event. Two models are considered: unilateral and bi-lateral failures of penny shaped cracks. From the seismic moment tensors of these sub-events, we consider different potential failure planes and rupture directions. Using numerical wave-propagation codes, we generate synthetic rupture sequences with both unilateral and bi-lateral ruptures. These are compared to the four sub-events to determine the directionality of the observed failures and the sensitivity of our recording bandwidth and geometry to distinguishing between different rupture processes. The frequency of unilateral and bilateral rupture processes throughout the fracture stimulation is estimated by comparing the directivity characteristics of the modeled sub-events to other high-quality microseismic events recorded during the same stimulation program. Understanding the failure processes of these microseismic events can provide great insight into the changes in the rock mass responsible for these complex rupture processes.

Secular pattern of aneurismal rupture with the lunar cycle and season.

PubMed

Banfield, Jillian C; Abdolell, Mohamed; Shankar, Jai S

2017-02-01

Background The lunar cycle and seasons may be associated with rates of rupture of intracranial aneurysms, but the literature is mixed. Studies of the association between the lunar cycle and rates of aneurysm rupture used the eight qualitative moon phases. The purpose of this study was to assess any association of aneurysm rupture with the lunar cycle and with the season. Materials and methods We retrospectively reviewed all cases of subarachnoid haemorrhage secondary to ruptured intracranial aneurysm treated with endovascular coiling in our institution over a 10-year period. We included only cases with a known rupture date. We used the degree of illumination of the moon to quantitatively code the lunar cycle. Results A total of 212 cases were included in our analyses. The odds of aneurysm rupture were significantly greater ( p < 0.001) when the moon was least (new moon) and most (full moon) illuminated, as compared to the middle of the lunar cycle. The odds of rupture tended to be higher ( p = 0.059) in the summer, compared to autumn. Conclusions The odds of aneurysm rupture were greater when the moon was least illuminated (new moon) and most illuminated (full moon), compared to the middle of the lunar cycle.

Multi-Fault Rupture Scenarios in the Brawley Seismic Zone

NASA Astrophysics Data System (ADS)

Kyriakopoulos, C.; Oglesby, D. D.; Rockwell, T. K.; Meltzner, A. J.; Barall, M.

2017-12-01

Dynamic rupture complexity is strongly affected by both the geometric configuration of a network of faults and pre-stress conditions. Between those two, the geometric configuration is more likely to be anticipated prior to an event. An important factor in the unpredictability of the final rupture pattern of a group of faults is the time-dependent interaction between them. Dynamic rupture models provide a means to investigate this otherwise inscrutable processes. The Brawley Seismic Zone in Southern California is an area in which this approach might be important for inferring potential earthquake sizes and rupture patterns. Dynamic modeling can illuminate how the main faults in this area, the Southern San Andreas (SSAF) and Imperial faults, might interact with the intersecting cross faults, and how the cross faults may modulate rupture on the main faults. We perform 3D finite element modeling of potential earthquakes in this zone assuming an extended array of faults (Figure). Our results include a wide range of ruptures and fault behaviors depending on assumptions about nucleation location, geometric setup, pre-stress conditions, and locking depth. For example, in the majority of our models the cross faults do not strongly participate in the rupture process, giving the impression that they are not typically an aid or an obstacle to the rupture propagation. However, in some cases, particularly when rupture proceeds slowly on the main faults, the cross faults indeed can participate with significant slip, and can even cause rupture termination on one of the main faults. Furthermore, in a complex network of faults we should not preclude the possibility of a large event nucleating on a smaller fault (e.g. a cross fault) and eventually promoting rupture on the main structure. Recent examples include the 2010 Mw 7.1 Darfield (New Zealand) and Mw 7.2 El Mayor-Cucapah (Mexico) earthquakes, where rupture started on a smaller adjacent segment and later cascaded into a larger event. For that reason, we are investigating scenarios of a moderate rupture on a cross fault, and determining conditions under which the rupture will propagate onto the adjacent SSAF. Our investigation will provide fundamental insights that may help us interpret faulting behaviors in other areas, such as the complex Mw 7.8 2016 Kaikoura (New Zealand) earthquake.

Precursory, Nucleation and Propagation of Ruptures Along Heterogeneously Loaded, Circular Experimental Faults

NASA Astrophysics Data System (ADS)

Reches, Z.; Zu, X.; Jeffers, J.

2017-12-01

We explored the evolution of dynamic rupture along a circular experimental fault composed of clear acrylic blocks. The ring-shaped fault surface has inner and outer diameters of 7.72 and 10.16 cm, respectively. An array of ten rossette strain-gauges is attached to the outer rim of one block that provide the 2D strain tensor in a plane normal to the fault. The 30 components of the gauges are monitored at 10^6 samples/second. One 3D miniature accelerometer is attached to the fault block. The initial asperities of the fault surface generated a non-uniform strain (=stress) distribution that was recorded, and indicated local deviations of ±30% from the mean stress. The mean normal stress was up to 3.5 MPa, the remotely applied velocity was up to .002 m/s, and the slip velocities during rupture were not measured. The rupture characteristics, namely propagation velocity and rupture front strain-field, were determined from strain-gauge outputs. The analysis of tens of stick-slip events revealed the following preliminary results: (1) The ruptures consistently nucleated at sites of high local strains (=stresses) that were formed by the pre-shear, normal stress loading. (2) The pre-rupture nucleation process was recognized a by temporal (< 0.1 s), local (<20 mm) reduction of the shear strain. (3) Commonly, the initiation of nucleation was associated with micro acoustic emissions, whereas the initiation of rupture was associated with intense acoustic activity. (4) Nucleation could occur quasi-simultaneously at two, highly stressed sites. (5) From the nucleation site, the ruptures propagated in two directions along the ring-shaped fault, and the collision between the two fronts led to rupture `shut-off'. (5) The strain-field of rupture fronts was well-recognized for ruptures propagating faster than 50 m/s, and the fastest fronts propagated at 1000 m/s. (7) It appears that the rupture front strain-field close to the nucleation site differs from the front strain-field far from nucleation site. (8) Post-shear examination of the fault surfaces revealed evidence of brittle wear of the acrylic including gouge formation, ploughing, and powder smearing. (9) Work in progress includes attempts to achieve faster dynamic ruptures, and the utilization of the existing monitoring system to rupture granite faults.

Traumatic graft rupture after primary and revision anterior cruciate ligament reconstruction: retrospective analysis of incidence and risk factors in 2915 cases.

PubMed

Schlumberger, Michael; Schuster, Philipp; Schulz, Martin; Immendörfer, Micha; Mayer, Philipp; Bartholomä, Jochen; Richter, Jörg

2017-05-01

To determine incidence and risk factors for traumatic graft rupture following primary and revision anterior cruciate ligament (ACL) reconstruction. All cases of isolated ACL reconstructions (primary or revision) performed at our institution between January 2007 and December 2010 were included. From this group of 2467 primary reconstructions (32.4 ± 12.2 years) and 448 revision reconstructions (33.0 ± 10.4 years), we identified all patients who underwent revision ACL reconstruction following traumatic graft rupture in further course and all patients who underwent contralateral primary ACL reconstruction until January 2014. Age, gender, time from index procedure and graft diameter (for hamstring autografts) were analysed in terms of being a potential risk factor for graft rupture. Within a follow-up period of 5.0 ± 1.1 years (3.0-7.0), a total of 82 traumatic graft ruptures were identified, resulting in an incidence of 2.8 %. Seventy-three cases were seen following primary reconstructions (3.0 %), and nine cases following revision reconstructions (2.0 %), respectively (n.s.). Age younger than 25 years was identified as a risk factor for both groups (p = 0.001 and p = 0.008; odds ratio 6.0 and 6.4, respectively). In primary reconstruction, male patients had a higher risk of graft rupture compared with females (3.7 vs. 1.6 %; p = 0.005), and the first year after index procedure was associated with a higher risk of graft rupture compared with the following (p < 0.001). Graft diameter did not influence the risk of graft rupture. Incidence of contralateral ACL rupture was 3.1 %, which was not different to the incidence of graft rupture ipsilaterally (n.s.). No statistically significant differences were seen between graft rupture incidence of primary and revision ACL reconstructions. Young age (<25 years) and short time to the index procedure (especially within the first year) were confirmed as risk factors for graft rupture in both groups. Male gender was a risk factor for primary reconstructions. Graft diameter had no influence on graft rupture rates. No difference in incidence of graft rupture compared to ACL rupture on the contralateral side was apparent. Retrospective case series, Level IV.

A Three Year Clinicopathological Study of Cases of Rupture Uterus

PubMed Central

Rathod, Setu; Swain, Sujata

2015-01-01

Introduction Rupture uterus is a life threatening obstetric complication with serious maternal and fetal side-effects. We report a 3 year (2010-2013) retrospective clinical study of pregnancy with rupture uterus cases attending a tertiary care hospital. Aim The aim of the study was to evaluate the incidence of rupture uterus, incidence as per age, parity, clinical presentations, risk factors, complications and management. Materials and Methods Retrospective data of 74 cases of rupture uterus in SCB Medical college, Cuttack was collected from case records of 26,547 deliveries during a 3 year span (2010-2013). Parameters like cause of rupture, type, site of rupture and outcome were recorded. The collected data was analysed by SPSS software v19. Results Out of 26,547 deliveries during the three year period, there were 74 cases of rupture uterus with an incidence of rupture 1 in 359 (0.28%). The mean age of rupture uterus was 27.4 years. 95.8% were multigravida and majority were referred cases from low socioeconomic status. Only 40.5% had the required minimum of four antenatal visits as recommended by WHO (World Health Organisation). A total of 48.6% of cases with rupture uterus had history of previous Caesarean section. Prolonged labour was present in 75.6% of the cases. Only 12.2% of the cases had history of oxytocin use whereas 9.5% had undergone an operative vaginal delivery. Obstructed labour was the cause in 24.3% of cases, 85.1% had complete rupture. Majority had a rupture in the anterior wall (69%) and 81.1% had rupture in lower segment of uterus. Only 17.6% had broad ligament haematoma, 10.8% colporrhexis and 6.8% had associated bladder injury. Repair was possible in only 39.2% of cases, whereas majority landed up in hysterectomy. Internal iliac ligation was done in 2.7% of cases. Perinatal mortality was 90.5% whereas maternal death was seen in 13.5% cases. One patient developed VVF (vesicovaginal fistula). Duration of hospital stay was upto 14 days in 81.1% cases. Conclusion Education and proper care especially of high risk patients like previous caesarean by competent personnal, proper use of oxytocin and early referral may help to reduce the incidence of “rupture uterus”. PMID:26673858

Reproductive Effects of Two Polybrominated Diphenyl Ethers on the Rotifer Brachionus plicatilis.

PubMed

Zhang, Jing; Wang, You; Zhou, Bin; Sun, Kai-Ming; Tang, Xuexi

2016-08-01

The effects of two polybrominated diphenyl ethers (PBDEs) on the reproduction of the rotifer Brachionus plicatilis were investigated. Results showed that sexual maturation was promoted by tetra-brominated diphenyl ether-47 (BDE-47) and deca-brominated diphenyl ether-209 (BDE-209), whereas fecundity was inhibited by BDE-47, but promoted by BDE-209. Additionally, both PBDEs affected the expression of two genes, vasa and nanos mRNA, related to rotifer reproduction. This suggests a possible regulatory molecular mechanism at the transcriptional level. Our research extends the current knowledge of the ecotoxicological mechanism induced by PBDEs and provides further essential information for assessing the risks of PBDE contamination in marine ecosystems.

Urea transporter knockout mice and their renal phenotypes.

PubMed

Fenton, Robert A; Yang, Baoxue

2014-01-01

Urea transporter gene knockout mice have been created for the study of the urine-concentrating mechanism. The major findings in studies of the renal phenotype of these mice are as follows: (1) Urea accumulation in the inner medullary interstitium is dependent on intrarenal urea recycling mediated by urea transporters; (2) urea transporters are essential for preventing urea-induced osmotic diuresis and thus for water conservation; (3) NaCl concentration in the inner medullary interstitium is not significantly affected by the absence of IMCD, descending limb of Henle and descending vasa recta urea transporters. Studies in urea transporter knockout mouse models have highlighted the essential role of urea for producing maximally concentrated urine.

Cryoglobulinemic neuropathy: a pathological study.

PubMed

Vallat, J M; Desproges-Gotteron, R; Leboutet, M J; Loubet, A; Gualde, N; Treves, R

1980-08-01

A 53-year-old woman developed symmetrical polyneuropathy of the lower limbs a few months after she was found to have myeloma with cryoglobulinemia. In musculocutaneous nerve biopsy material, electron microscopy showed both axonal degeneration and demyelination. The most striking finding was the presence, in the endoneurial space, of numerous masses of closely packed tubular structures. These masses also were found in the walls of all the vasa nervorum and within the lumen of some vessels. The morphological features and dimensions of the deposits within nerve were identical to those of cryoprecipitates extracted from serum and examined with the electron microscope. An example of myeloma neuropathy with cryoglobulin deposits within the endoneurial space has not been reported previously.

EVALUATION OF CONTRAST-ENHANCED ULTRASONOGRAPHY AS A METHOD FOR DETECTING GALLBLADDER NECROSIS OR RUPTURE IN DOGS.

PubMed

Bargellini, Paolo; Orlandi, Riccardo; Paloni, Chiara; Rubini, Giuseppe; Fonti, Paolo; Peterson, Mark E; Rishniw, Mark; Boiti, Cristiano

2016-11-01

Gall bladder necrosis and rupture are life-threatening conditions in dogs requiring surgical intervention and early diagnosis is essential. Human patients with suspected gall bladder necrosis/rupture are commonly evaluated with contrast-enhanced ultrasonography (CEUS), however this procedure has not been described in dogs with suspected gall bladder necrosis/rupture. In a prospective diagnostic cohort study, CEUS (using SonoVue contrast medium) was performed in 93 dogs with gallbladder lesions identified by abdominal conventional ultrasonography. Necrosis/rupture was identified by CEUS as a focal lack of enhancement of the gallbladder wall. Dogs with positive CEUS finding for necrosis/rupture (complete lack of regional wall enhancement) underwent immediate surgery as did dogs with other biliary disorders requiring surgery. Dogs with negative CEUS findings or those not requiring surgery were managed medically. In cases undergoing surgery, necrosis/rupture was confirmed intraoperatively (and via histopathology). Absence of necrosis/rupture was confirmed either intraoperatively (via histopathology) or was assumed to be absent by complete recovery with medical management. Forty-nine dogs underwent surgery and cholecystectomy: 24 had necrosis/rupture. CEUS was more accurate (100% sensitive and specific) in diagnosing gallbladder wall necrosis/rupture than conventional ultrasonography (75% sensitive and 81% specific) (P < 0.03). In conclusion, CEUS provides accurate characterization of gallbladder wall integrity that can impact decisions regarding clinical management, either surgical or medical. © 2016 American College of Veterinary Radiology.

Size ratio correlates with intracranial aneurysm rupture status: a prospective study.

PubMed

Rahman, Maryam; Smietana, Janel; Hauck, Erik; Hoh, Brian; Hopkins, Nick; Siddiqui, Adnan; Levy, Elad I; Meng, Hui; Mocco, J

2010-05-01

The prediction of intracranial aneurysm (IA) rupture risk has generated significant controversy. The findings of the International Study of Unruptured Intracranial Aneurysms (ISUIA) that small anterior circulation aneurysms (<7 mm) have a 0% risk of subarachnoid hemorrhage in 5 years is difficult to reconcile with other studies that reported a significant portion of ruptured IAs are small. These discrepancies have led to the search for better aneurysm parameters to predict rupture. We previously reported that size ratio (SR), IA size divided by parent vessel diameter, correlated strongly with IA rupture status (ruptured versus unruptured). These data were all collected retrospectively off 3-dimensional angiographic images. Therefore, we performed a blinded prospective collection and evaluation of SR data from 2-dimensional angiographic images for a consecutive series of patients with ruptured and unruptured IAs. We prospectively enrolled 40 consecutive patients presenting to a single institution with either ruptured IA or for first-time evaluation of an incidental IA. Blinded technologists acquired all measurements from 2-dimensional angiographic images. Aneurysm rupture status, location, IA maximum size, and parent vessel diameter were documented. The SR was calculated by dividing the aneurysm size (mm) by the average parent vessel size (mm). A 2-tailed Mann-Whitney test was performed to assess statistical significance between ruptured and unruptured groups. Fisher exact test was used to compare medical comorbidities between the ruptured and unruptured groups. Significant differences between the 2 groups were subsequently tested with logistic regression. SE and probability values are reported. Forty consecutive patients with 24 unruptured and 16 ruptured aneurysms met the inclusion criteria. No significant differences were found in age, gender, smoking status, or medical comorbidities between ruptured and unruptured groups. The average maximum size of the unruptured IAs (6.18 + or - 0.60 mm) was significantly smaller compared with the ruptured IAs (7.91 + or - 0.47 mm; P=0.03), and the unruptured group had significantly smaller SRs (2.57 + or - 0.24 mm) compared with the ruptured group (4.08 + or - 0.54 mm; P<0.01). Logistic regression was used to evaluate the independent predictive value of those variables that achieved significance in univariate analysis (IA maximum size and SR). Using stepwise selection, only SR remained in the final predictive model (OR, 2.12; 95% CI, 1.09 to 4.13). SR, the ratio between aneurysm size and parent artery diameter, can be easily calculated from 2-dimensional angiograms and correlates with IA rupture status on presentation in a blinded analysis. SR should be further studied in a large prospective observational cohort to predict true IA risk of rupture.

Preterm premature rupture of membranes at 22-25 weeks' gestation: perinatal and 2-year outcomes within a national population-based study (EPIPAGE-2).

PubMed

Lorthe, Elsa; Torchin, Héloïse; Delorme, Pierre; Ancel, Pierre-Yves; Marchand-Martin, Laetitia; Foix-L'helias, Laurence; Benhammou, Valérie; Gire, Catherine; D'Ercole, Claude; Winer, Norbert; Sentilhes, Loïc; Subtil, Damien; Goffinet, François; Kayem, Gilles

2018-05-28

Most clinical guidelines state that with early preterm premature rupture of membranes, obstetric and pediatric teams must share a realistic and individualized appraisal of neonatal outcomes with parents and consider their wishes for all decisions. However, we currently lack reliable and relevant data, according to gestational age at rupture of membranes, to adequately counsel parents during pregnancy and to reflect on our policies of care at these extreme gestational ages. To describe both perinatal and 2-year outcomes of preterm infants born after preterm premature rupture of membranes at 22-25 weeks' gestation. EPIPAGE-2 is a French national prospective population-based cohort of preterm infants born in 546 maternity units in 2011. Inclusion criteria in this analysis were women diagnosed with preterm premature rupture of membranes at 22-25 weeks' gestation and singleton or twin gestations with fetus(es) alive at rupture of membranes. Latency duration, antenatal management, and outcomes (survival at discharge, survival at discharge without severe morbidity, and survival at 2 years' corrected age without cerebral palsy) were described and compared by gestational age at preterm premature rupture of membranes. Among the 1435 women with a diagnosis of preterm premature rupture of membranes, 379 were at 22-25 weeks' gestation, with 427 fetuses (331 singletons and 96 twins). Median GA at preterm premature rupture of membranes and at birth were 24 (interquartile range 23-25) and 25 (24-27) weeks, respectively. For each gestational age at preterm premature rupture of membranes, nearly half of the fetuses were born within the week after the rupture of membranes. Among the 427 fetuses, 51.7% were survivors at discharge (14.1%, 39.5%, 66.8% and 75.8% with preterm premature rupture of membranes at 22, 23, 24 and 25 weeks, respectively), 38.8% were survivors at discharge without severe morbidity and 46.4% were survivors at 2 years without cerebral palsy, with wide variations by gestational age at preterm premature rupture of membranes. Survival at 2 years without cerebral palsy was low with preterm premature rupture of membranes at 22 and 23 weeks but reached approximately 60% and 70% with preterm premature rupture of membranes at 24 and 25 weeks. Preterm premature rupture of membranes at 22-25 weeks is associated with high incidence of mortality and morbidity, with wide variations by gestational age at preterm premature rupture of membranes. However, a non-negligible proportion of children survive without severe morbidity both at discharge and at 2-years' corrected age. Copyright © 2018 Elsevier Inc. All rights reserved.

Induced seismicity provides insight into why earthquake ruptures stop

PubMed Central

Galis, Martin; Ampuero, Jean Paul; Mai, P. Martin; Cappa, Frédéric

2017-01-01

Injection-induced earthquakes pose a serious seismic hazard but also offer an opportunity to gain insight into earthquake physics. Currently used models relating the maximum magnitude of injection-induced earthquakes to injection parameters do not incorporate rupture physics. We develop theoretical estimates, validated by simulations, of the size of ruptures induced by localized pore-pressure perturbations and propagating on prestressed faults. Our model accounts for ruptures growing beyond the perturbed area and distinguishes self-arrested from runaway ruptures. We develop a theoretical scaling relation between the largest magnitude of self-arrested earthquakes and the injected volume and find it consistent with observed maximum magnitudes of injection-induced earthquakes over a broad range of injected volumes, suggesting that, although runaway ruptures are possible, most injection-induced events so far have been self-arrested ruptures. PMID:29291250

Systematic Underestimation of Earthquake Magnitudes from Large Intracontinental Reverse Faults: Historical Ruptures Break Across Segment Boundaries

NASA Technical Reports Server (NTRS)

Rubin, C. M.

1996-01-01

Because most large-magnitude earthquakes along reverse faults have such irregular and complicated rupture patterns, reverse-fault segments defined on the basis of geometry alone may not be very useful for estimating sizes of future seismic sources. Most modern large ruptures of historical earthquakes generated by intracontinental reverse faults have involved geometrically complex rupture patterns. Ruptures across surficial discontinuities and complexities such as stepovers and cross-faults are common. Specifically, segment boundaries defined on the basis of discontinuities in surficial fault traces, pronounced changes in the geomorphology along strike, or the intersection of active faults commonly have not proven to be major impediments to rupture. Assuming that the seismic rupture will initiate and terminate at adjacent major geometric irregularities will commonly lead to underestimation of magnitudes of future large earthquakes.

The persistence of directivity in small earthquakes

USGS Publications Warehouse

Boatwright, J.

2007-01-01

We derive a simple inversion of peak ground acceleration (PGA) or peak ground velocity (PGV) for rupture direction and rupture velocity and then test this inversion on the peak motions obtained from seven 3.5 ??? M ??? 4.1 earthquakes that occurred in two clusters in November 2002 and February 2003 near San Ramon, California. These clusters were located on two orthogonal strike-slip faults so that the events share the same approximate focal mechanism but not the same fault plane. Three earthquakes exhibit strong directivity, but the other four earthquakes exhibit relatively weak directivity. We use the residual PGAs and PGVs from the other six events to determine station corrections for each earthquake. The inferred rupture directions unambiguously identify the fault plane for the three earthquakes with strong directivity and for three of the four earthquakes with weak directivity. The events with strong directivity have fast rupture velocities (0.63????? v ??? 0.87??); the events with weak directivity either rupture more slowly (0.17????? v ???0.35??) or bilaterally. The simple unilateral inversion cannot distinguish between slow and bilateral ruptures: adding a bilateral rupture component degrades the fit of the rupture directions to the fault planes. By comparing PGAs from the events with strong and weak directivity, we show how an up-dip rupture in small events can distort the attenuation of peak ground motion with distance. When we compare the rupture directions of the earthquakes to the location of aftershocks in the two clusters, we find than almost all the aftershocks of the three earthquakes with strong directivity occur within 70?? of the direction of rupture.

Role of intramural platelet thrombus in the pathogenesis of wall rupture and intra-ventricular thrombosis following acute myocardial infarction.

PubMed

Du, Xiao-Jun; Shan, Leonard; Gao, Xiao-Ming; Kiriazis, Helen; Liu, Yang; Lobo, Abhirup; Head, Geoffrey A; Dart, Anthony M

2011-02-01

Left ventricular thrombus (LVT) and rupture are important mechanical complications following myocardial infarction (MI) and are believed to be due to unrelated mechanisms. We studied whether, in fact, wall rupture and LVT are closely related in their pathogenesis with intramural platelet thrombus (IMT) playing a pivotal role. Male 129sv and C57Bl/6 mice underwent operation to induce MI, and autopsy was performed to confirm rupture deaths. Haemodynamic features of rupture events were monitored by telemetry in conscious mice. Detailed histological examination was conducted with special attention to the presence of IMT in relation to rupture location and LVT formation. IMT was detected in infarcted hearts of 129sv (82%) and C57Bl/6 (39%) mice with rupture in the form of a narrow streak spanning the wall or an occupying mass dissecting the infarcted myofibers apart. IMT often contained dense inflammatory cells and blood clot, indicating a dynamic process of thrombus formation and destruction. Notably, IMT was found extending into the cavity to form LVT. Haemodynamic monitoring by telemetry revealed that rupture occurred either as a single event or recurrent episodes. Importantly, the anti-platelet drug clopidogrel, but not aspirin, reduced the prevalence of rupture (10% vs. 45%) and IMT, and suppressed the degree of inflammation. Thus, IMT is a key pathological element in the infarcted heart closely associated with the complications of rupture and LVT. IMT could be either triggered by a wall tear or act as initiator of rupture. IMT may propagate towards the ventricular chamber to trigger LVT.

Infectious mononucleosis presenting as spontaneous splenic rupture without other symptoms.

PubMed

Stockinger, Zsolt T

2003-09-01

Splenic rupture is an uncommon complication of infectious mononucleosis (IM), occurring in 0.1% to 0.5% of all patients. It remains the most common lethal complication of IM. Rupture of the spleen with no other symptoms of IM is almost unheard of. This is the report of a case of spontaneous splenic rupture requiring splenectomy in a patient with a positive heterophil antibody test and no other signs or symptoms of IM. The diagnosis and management of splenic rupture in IM are discussed.

Time-resolved observation of thermally activated rupture of a capillary-condensed water nanobridge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bak, Wan; Sung, Baekman; Kim, Jongwoo

2015-01-05

The capillary-condensed liquid bridge is one of the most ubiquitous forms of liquid in nature and contributes significantly to adhesion and friction of biological molecules as well as microscopic objects. Despite its important role in nanoscience and technology, the rupture process of the bridge is not well understood and needs more experimental works. Here, we report real-time observation of rupture of a capillary-condensed water nanobridge in ambient condition. During slow and stepwise stretch of the nanobridge, we measured the activation time for rupture, or the latency time required for the bridge breakup. By statistical analysis of the time-resolved distribution ofmore » activation time, we show that rupture is a thermally activated stochastic process and follows the Poisson statistics. In particular, from the Arrhenius law that the rupture rate satisfies, we estimate the position-dependent activation energies for the capillary-bridge rupture.« less

Systematic observations of the slip pulse properties of large earthquake ruptures

USGS Publications Warehouse

Melgar, Diego; Hayes, Gavin

2017-01-01

In earthquake dynamics there are two end member models of rupture: propagating cracks and self-healing pulses. These arise due to different properties of faults and have implications for seismic hazard; rupture mode controls near-field strong ground motions. Past studies favor the pulse-like mode of rupture; however, due to a variety of limitations, it has proven difficult to systematically establish their kinematic properties. Here we synthesize observations from a database of >150 rupture models of earthquakes spanning M7–M9 processed in a uniform manner and show the magnitude scaling properties of these slip pulses indicates self-similarity. Further, we find that large and very large events are statistically distinguishable relatively early (at ~15 s) in the rupture process. This suggests that with dense regional geophysical networks strong ground motions from a large rupture can be identified before their onset across the source region.

Seismogenic width controls aspect ratios of earthquake ruptures

NASA Astrophysics Data System (ADS)

Weng, Huihui; Yang, Hongfeng

2017-03-01

We investigate the effect of seismogenic width on aspect ratios of earthquake ruptures by using numerical simulations of strike-slip faulting and an energy balance criterion near rupture tips. If the seismogenic width is smaller than a critical value, then ruptures cannot break the entire fault, regardless of the size of the nucleation zone. The seismic moments of these self-arresting ruptures increase with the nucleation size, forming nucleation-related events. The aspect ratios increase with the seismogenic width but are smaller than 8. In contrast, ruptures become breakaway and tend to have high aspect ratios (>8) if the seismogenic width is sufficiently large. But the critical nucleation size is larger than the theoretical estimate for an unbounded fault. The eventual seismic moments of breakaway ruptures do not depend on the nucleation size. Our results suggest that estimating final earthquake magnitude from the nucleation phase may only be plausible on faults with small seismogenic width.

A retrospective study of eyeball rupture in patients with or without orbital fracture

PubMed Central

Chen, Xiang; Yao, Yi; Wang, Fengxiang; Liu, Tiecheng; Zhao, Xiao

2017-01-01

Abstract To summarize the clinical features of eyeball rupture with or without orbital fracture and explore the differences between them. In all, 197 patients were observed, and the following data were recorded: sex, age, time of injury, place of injury, cause of trauma, zone of eye injury, intraocular content prolapse, surgical methods and the therapeutic process, visual acuity after injury, and the final best corrected visual acuity. The results were analyzed for statistically significant differences. There was no significant difference (P > .05) in the age, sex, or cause of injury. Patients with eyeball rupture with fracture had poorer vision than did those in the simple eyeball rupture group; eyeball rupture with fracture also had a higher probability of enucleation. In this study, the clinical results show that prognosis of eyeball rupture with orbital fracture is worse than that of eyeball rupture without orbital fracture. PMID:28614230

A retrospective study of eyeball rupture in patients with or without orbital fracture.

PubMed

Chen, Xiang; Yao, Yi; Wang, Fengxiang; Liu, Tiecheng; Zhao, Xiao

2017-06-01

To summarize the clinical features of eyeball rupture with or without orbital fracture and explore the differences between them.In all, 197 patients were observed, and the following data were recorded: sex, age, time of injury, place of injury, cause of trauma, zone of eye injury, intraocular content prolapse, surgical methods and the therapeutic process, visual acuity after injury, and the final best corrected visual acuity. The results were analyzed for statistically significant differences.There was no significant difference (P > .05) in the age, sex, or cause of injury. Patients with eyeball rupture with fracture had poorer vision than did those in the simple eyeball rupture group; eyeball rupture with fracture also had a higher probability of enucleation.In this study, the clinical results show that prognosis of eyeball rupture with orbital fracture is worse than that of eyeball rupture without orbital fracture.

Heterogeneous rupture on homogenous faults: Three-dimensional spontaneous rupture simulations with thermal pressurization

NASA Astrophysics Data System (ADS)

Urata, Yumi; Kuge, Keiko; Kase, Yuko

2008-11-01

To understand role of fluid on earthquake rupture processes, we investigated effects of thermal pressurization on spatial variation of dynamic rupture by computing spontaneous rupture propagation on a rectangular fault. We found thermal pressurization can cause heterogeneity of rupture even on a fault of uniform properties. On drained faults, tractions drop linearly with increasing slip in the same way everywhere. However, by changing the drained condition to an undrained one, the slip-weakening curves become non-linear and depend on locations on faults with small shear zone thickness w, and the dynamic frictional stresses vary spatially and temporally. Consequently, the super-shear transition fault length decreases for small w, and the final slip distribution can have some peaks regardless of w, especially on undrained faults. These effects should be taken into account of determining dynamic rupture parameters and modeling earthquake cycles when the presence of fluid is suggested in the source regions.

[Traumatic rupture of hepatic hydatid cyst].

PubMed

Martino, A; Rampone, B; Schiavone, B; Viviano, C; Cuomo, O; Iovine, L; Sacco, M; Maharajan, G; Confuorto, G

2010-01-01

Hydatid disease is endemic in some areas of the world. It is located mostly in the liver. The cysts rupture is possible after a trauma, or spontaneously by the increase of intracystic pressure. Rupture of the hydatid cyst requires urgent surgical intervention. We report our experience in treatment of traumatic rupture of hepatic hydatid cyst.

Risk factors for achilles tendon rupture: A matched case control study.

PubMed

Noback, Peter C; Jang, Eugene S; Cuellar, Derly O; Seetharaman, Mani; Malagoli, Emiliano; Greisberg, Justin K; Vosseller, J Turner

2017-10-01

The purpose of this study was to elucidate whether body mass index (BMI), activity level, and other risk factors predispose patients to Achilles tendon ruptures. A retrospective review of 279 subjects was performed (93 with Achilles tendon rupture, matched 1:2 with 186 age/sex matched controls with ankle sprains). Demographic variables and risk factors for rupture were tabulated and compared. The rupture group mean BMI was 27.77 (95% CI, 26.94-28.49), and the control group mean BMI was 26.66 (95% CI, 26.06-27.27). These populations were found to be statistically equivalent (p=0.047 and p<0.001 by two one-sided t-test). A significantly higher proportion of those suffering ruptures reported regular athletic activity at baseline (74%) versus controls (59%, p=0.013). There was no clinically significant difference found in BMI between patients with ruptures and controls. Furthermore, it was found that patients who sustained ruptures were also more likely to be active at baseline than their ankle sprain counterparts. Copyright © 2017 Elsevier Ltd. All rights reserved.

High-speed rupture during the initiation of the 2015 Bonin Islands deep earthquake

NASA Astrophysics Data System (ADS)

Zhan, Z.; Ye, L.; Shearer, P. M.; Lay, T.; Kanamori, H.

2015-12-01

Among the long-standing questions on how deep earthquakes rupture, the nucleation phase of large deep events is one of the most puzzling parts. Resolving the rupture properties of the initiation phase is difficult to achieve with far-field data because of the need for accurate corrections for structural effects on the waveforms (e.g., attenuation, scattering, and site effects) and alignment errors. Here, taking the 2015 Mw 7.9 Bonin Islands earthquake (depth = 678 km) as an example, we jointly invert its far-field P waves at multiple stations for the average rupture speed during the first second of the event. We use waveforms from a closely located aftershock as empirical Green's functions, and correct for possible differences in focal mechanisms and waveform misalignments with an iterative approach. We find that the average initial rupture speed is over 5 km/s, significantly higher than the average rupture speed of 3 km/s later in the event. This contrast suggests that rupture speeds of deep earthquakes can be highly variable during individual events and may define different stages of rupture, potentially with different mechanisms.

Partial achilles tendon rupture presenting with giant hematoma; MRI findings of 4 year follow up.

PubMed

Sarsilmaz, Aysegul; Varer, Makbule; Coskun, Gulten; Apaydın, Melda; Oyar, Orhan

2011-12-01

In the young population, spontaneous rupture of Achilles tendon is very rare. The big hematoma is also rare finding of the Achilles tendon partial rupture. It is usually seen with complete rupture. We presented imaging findings of 4 years follow up of the spontaneous partial rupture of Achilles tendon presenting with giant expanding hematoma and mimicking complete rupture radiologically. We discussed the alterations of tendon signal intensity and result of conservative therapy after partial rupture with big hematoma in the long term. A 29 year-old man, applied with pain and swelling in the retrocalcaneal region of left ankle. He did not have chronic metabolic disease. He was not active in physical activities. X-ray radiograms were normal. At magnetic resonance images (MRI), there was an intratendinous big hematoma, subcutanous fat planes were edematous around tendon. The diagnosis was partial rupture and giant hematoma. Hematoma was drained. The conservative treatment was applied and his complaints disappeared. After treatment, approximately 4 years later, control MRI showed thickened and hypointense tendon in all images. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Shigella subverts the host recycling compartment to rupture its vacuole.

PubMed

Mellouk, Nora; Weiner, Allon; Aulner, Nathalie; Schmitt, Christine; Elbaum, Michael; Shorte, Spencer L; Danckaert, Anne; Enninga, Jost

2014-10-08

Shigella enters epithlial cells via internalization into a vacuole. Subsequent vacuolar membrane rupture allows bacterial escape into the cytosol for replication and cell-to-cell spread. Bacterial effectors such as IpgD, a PI(4,5)P2 phosphatase that generates PI(5)P and alters host actin, facilitate this internalization. Here, we identify host proteins involved in Shigella uptake and vacuolar membrane rupture by high-content siRNA screening and subsequently focus on Rab11, a constituent of the recycling compartment. Rab11-positive vesicles are recruited to the invasion site before vacuolar rupture, and Rab11 knockdown dramatically decreases vacuolar membrane rupture. Additionally, Rab11 recruitment is absent and vacuolar rupture is delayed in the ipgD mutant that does not dephosphorylate PI(4,5)P₂ into PI(5)P. Ultrastructural analyses of Rab11-positive vesicles further reveal that ipgD mutant-containing vacuoles become confined in actin structures that likely contribute to delayed vacular rupture. These findings provide insight into the underlying molecular mechanism of vacuole progression and rupture during Shigella invasion. Copyright © 2014 Elsevier Inc. All rights reserved.

Rupture history of 2008 May 12 Mw 8.0 Wen-Chuan earthquake: Evidence of slip interaction

NASA Astrophysics Data System (ADS)

Ji, C.; Shao, G.; Lu, Z.; Hudnut, K.; Jiu, J.; Hayes, G.; Zeng, Y.

2008-12-01

We will present the rupture process of the May 12, 2008 Mw 8.0 Wenchuan earthquake using all available data. The current model, using both teleseismic body and surface waves and interferometric LOS displacements, reveals an unprecedented complex rupture process which can not be resolved using either of the datasets individually. Rupture of this earthquake involved both the low angle Pengguan fault and the high angle Beichuan fault, which intersect each other at depth and are separated approximately 5-15 km at the surface. Rupture initiated on the Pengguan fault and triggered rupture on the Beichuan fault 10 sec later. The two faults dynamically interacted and unilaterally ruptured over 270 km with an average rupture velocity of 3.0 km/sec. The total seismic moment is 1.1x1021 Nm (Mw 8.0), roughly equally partitioned between the two faults. However, the spatiotemporal evaluations of the two faults are very different. This study will focus on the evidence for fault interactions and will analyze the corresponding uncertainties, in preparation for future dynamic studies of the same detailed nature.

Pulsed strain release on the Altyn Tagh fault, northwest China

USGS Publications Warehouse

Gold, Ryan D.; Cowgill, Eric; Arrowsmith, J. Ramón; Friedrich, Anke M.

2017-01-01

Earthquake recurrence models assume that major surface-rupturing earthquakes are followed by periods of reduced rupture probability as stress rebuilds. Although purely periodic, time- or slip-predictable rupture models are known to be oversimplifications, a paucity of long records of fault slip clouds understanding of fault behavior and earthquake recurrence over multiple ruptures. Here, we report a 16 kyr history of fault slip—including a pulse of accelerated slip from 6.4 to 6.0 ka—determined using a Monte Carlo analysis of well-dated offset landforms along the central Altyn Tagh strike-slip fault (ATF) in northwest China. This pulse punctuates a median rate of 8.1+1.2/−0.9 mm/a and likely resulted from either a flurry of temporally clustered ∼Mw 7.5 ground-rupturing earthquakes or a single large >Mw 8.2 earthquake. The clustered earthquake scenario implies rapid re-rupture of a fault reach >195 km long and indicates decoupled rates of elastic strain energy accumulation versus dissipation, conceptualized as a crustal stress battery. If the pulse reflects a single event, slip-magnitude scaling implies that it ruptured much of the ATF with slip similar to, or exceeding, the largest documented historical ruptures. Both scenarios indicate fault rupture behavior that deviates from classic time- or slip-predictable models.

Identification of vortex structures in a cohort of 204 intracranial aneurysms

PubMed Central

Trylesinski, Gabriel; Xiang, Jianping; Snyder, Kenneth; Meng, Hui

2017-01-01

An intracranial aneurysm (IA) is a cerebrovascular pathology that can lead to death or disability if ruptured. Abnormal wall shear stress (WSS) has been associated with IA growth and rupture, but little is known about the underlying flow physics related to rupture-prone IAs. Previous studies, based on analysis of a few aneurysms or partial views of three-dimensional vortex structures, suggest that rupture is associated with complex vortical flow inside IAs. To further elucidate the relevance of vortical flow in aneurysm pathophysiology, we studied 204 patient IAs (56 ruptured and 148 unruptured). Using objective quantities to identify three-dimensional vortex structures, we investigated the characteristics associated with aneurysm rupture and if these features correlate with previously proposed WSS and morphological characteristics indicative of IA rupture. Based on the Q-criterion definition of a vortex, we quantified the degree of the aneurysmal region occupied by vortex structures using the volume vortex fraction (vVF) and the surface vortex fraction (sVF). Computational fluid dynamics simulations showed that the sVF, but not the vVF, discriminated ruptured from unruptured aneurysms. Furthermore, we found that the near-wall vortex structures co-localized with regions of inflow jet breakdown, and significantly correlated to previously proposed haemodynamic and morphologic characteristics of ruptured IAs. PMID:28539480

Identification of vortex structures in a cohort of 204 intracranial aneurysms.

PubMed

Varble, Nicole; Trylesinski, Gabriel; Xiang, Jianping; Snyder, Kenneth; Meng, Hui

2017-05-01

An intracranial aneurysm (IA) is a cerebrovascular pathology that can lead to death or disability if ruptured. Abnormal wall shear stress (WSS) has been associated with IA growth and rupture, but little is known about the underlying flow physics related to rupture-prone IAs. Previous studies, based on analysis of a few aneurysms or partial views of three-dimensional vortex structures, suggest that rupture is associated with complex vortical flow inside IAs. To further elucidate the relevance of vortical flow in aneurysm pathophysiology, we studied 204 patient IAs (56 ruptured and 148 unruptured). Using objective quantities to identify three-dimensional vortex structures, we investigated the characteristics associated with aneurysm rupture and if these features correlate with previously proposed WSS and morphological characteristics indicative of IA rupture. Based on the Q -criterion definition of a vortex, we quantified the degree of the aneurysmal region occupied by vortex structures using the volume vortex fraction ( vVF ) and the surface vortex fraction ( sVF ). Computational fluid dynamics simulations showed that the sVF , but not the vVF , discriminated ruptured from unruptured aneurysms. Furthermore, we found that the near-wall vortex structures co-localized with regions of inflow jet breakdown, and significantly correlated to previously proposed haemodynamic and morphologic characteristics of ruptured IAs. © 2017 The Author(s).

Spontaneous splenic rupture in an active duty Marine upon return from Iraq: a case report

PubMed Central

2010-01-01

Introduction Atraumatic splenic rupture is a rare event that has been associated with several infectious disease processes. In the active duty military population, potential exposure to these pathogens is significant. Here we discuss the case of an active duty Marine with spontaneous splenic rupture upon return from a six-month deployment in Iraq. Case presentation A previously healthy 30-year-old Caucasian male active duty Marine presented with abdominal pain, fever and diarrhea after deployment to Iraq in support of Operation Iraqi Freedom. Based on clinical and radiographic evidence, a diagnosis of spontaneous splenic rupture was ultimately suspected. After exploratory laparotomy with confirmation of rupture, splenectomy was performed, and the patient made a full, uneventful recovery. Histopathologic examination revealed mild splenomegaly with a ruptured capsule of undetermined cause. Conclusion Spontaneous splenic rupture is a rare event that may lead to life-threatening hemorrhage if not diagnosed and treated quickly. Although the cause of this patient's case was unknown, atraumatic splenic rupture has been associated with a variety of infectious diseases and demonstrates some risks the active duty military population may face while on deployment. Having an awareness of these pathogens and their role in splenic rupture, clinicians caring for military personnel must be prepared to recognize and treat this potentially fatal complication. PMID:21054871

Diverse rupture processes in the 2015 Peru deep earthquake doublet.

PubMed

Ye, Lingling; Lay, Thorne; Kanamori, Hiroo; Zhan, Zhongwen; Duputel, Zacharie

2016-06-01

Earthquakes in deeply subducted oceanic lithosphere can involve either brittle or dissipative ruptures. On 24 November 2015, two deep (606 and 622 km) magnitude 7.5 and 7.6 earthquakes occurred 316 s and 55 km apart. The first event (E1) was a brittle rupture with a sequence of comparable-size subevents extending unilaterally ~50 km southward with a rupture speed of ~4.5 km/s. This earthquake triggered several aftershocks to the north along with the other major event (E2), which had 40% larger seismic moment and the same duration (~20 s), but much smaller rupture area and lower rupture speed than E1, indicating a more dissipative rupture. A minor energy release ~12 s after E1 near the E2 hypocenter, possibly initiated by the S wave from E1, and a clear aftershock ~165 s after E1 also near the E2 hypocenter, suggest that E2 was likely dynamically triggered. Differences in deep earthquake rupture behavior are commonly attributed to variations in thermal state between subduction zones. However, the marked difference in rupture behavior of the nearby Peru doublet events suggests that local variations of stress state and material properties significantly contribute to diverse behavior of deep earthquakes.

Risk Factors for the Rupture of Intracranial Aneurysms Using Computed Tomography Angiography.

PubMed

Wang, Guang-Xian; Wen, Li; Yang, Liu; Zhang, Qi-Chuang; Yin, Jin-Bo; Duan, Chun-Mei; Zhang, Dong

2018-02-01

To study the clinical and morphologic characteristics associated with risk factors for the rupture of intracranial aneurysms (IAs). A total of 1115 consecutive patients with 1282 IAs were reviewed from August 2011 to February 2016. The patients and IAs were divided into ruptured and unruptured groups. Based on the clinical and morphologic findings, the risk factors for IA rupture were assessed using statistical methods. Age, hypertension, diabetes mellitus, and cerebral atherosclerosis were associated with ruptured IAs. IAs located in the anterior cerebral artery, the anterior communicating artery, the posterior communicating artery, and the internal carotid artery were associated with ruptured IAs. Ruptures were also associated with arterial bifurcations, irregular aneurysm shapes, and all continuous data, except neck width. Binary logistic regression showed that IAs located at bifurcations (odds ratio [OR], 1.804), with irregular shapes (OR, 4.677), with high aspect ratios (ARs) (OR, 5.037) or with small mean diameters (MDs) (OR, 0.495) are more prone to rupture. Receiver operating characteristic analysis showed that the threshold values of the AR and MD were 1 and 3.70 mm, respectively. Morphologic characteristics, such as being located at bifurcations, being irregularly shaped, having a high AR (>1), and having a small MD (<3.70 mm), were better predictors of rupture. Copyright © 2017 Elsevier Inc. All rights reserved.

Correlation between atmospheric pressure changes and abdominal aortic aneurysm rupture: results of a single-center study.

PubMed

Molacek, Jiri; Treska, Vladislav; Kasik, Miroslav; Houdek, Karel; Baxa, Jan

2013-09-01

There is much interest in all factors that influence the etiopathogenesis of abdominal aortic aneurysm (AAA) rupture. Apart from the well-established factors such as arterial hypertension, smoking, age, and genetic predisposition, less common factors that may play a role in the mechanism of the rupture are the subject of much discussion. These include atmospheric conditions, temperature, and atmospheric pressure. We conducted this study to investigate the effects of the absolute value of atmospheric pressure and its changes on the frequency of AAA rupture. We retrospectively examined 54 patients who underwent treatment for a ruptured AAA at the Clinic of Surgery in the University Hospital in Pilsen between 1 January 2005 and 31 December 2009. We collected data on the atmospheric pressure in this period from the Czech Hydrometeorological Institute in Pilsen. We did not find a significant difference in atmospheric pressure values between the days when the rupture occurred versus the other days (p < 0.5888). Moreover, we did not find significant changes in the atmospheric pressure during the 48 h preceding the rupture (Student's test p < 0.4434) versus the day of rupture or in the mean atmospheric pressure in that month. These findings suggest that atmospheric pressure and its changes do not affect the pathogenesis of AAA rupture.

Dynamic rupture modeling of thrust faults with parallel surface traces.

NASA Astrophysics Data System (ADS)

Peshette, P.; Lozos, J.; Yule, D.

2017-12-01

Fold and thrust belts (such as those found in the Himalaya or California Transverse Ranges) consist of many neighboring thrust faults in a variety of geometries. Active thrusts within these belts individually contribute to regional seismic hazard, but further investigation is needed regarding the possibility of multi-fault rupture in a single event. Past analyses of historic thrust surface traces suggest that rupture within a single event can jump up to 12 km. There is also observational precedent for long distance triggering between subparallel thrusts (e.g. the 1997 Harnai, Pakistan events, separated by 50 km). However, previous modeling studies find a maximum jumping rupture distance between thrust faults of merely 200 m. Here, we present a new dynamic rupture modeling parameter study that attempts to reconcile these differences and determine which geometrical and stress conditions promote jumping rupture. We use a community verified 3D finite element method to model rupture on pairs of thrust faults with parallel surface traces. We vary stress drop and fault strength to determine which conditions produce jumping rupture at different dip angles and different separations between surface traces. This parameter study may help to understand the likelihood of jumping rupture in real-world thrust systems, and may thereby improve earthquake hazard assessment.

A multiple fault rupture model of the November 13 2016, M 7.8 Kaikoura earthquake, New Zealand

NASA Astrophysics Data System (ADS)

Benites, R. A.; Francois-Holden, C.; Langridge, R. M.; Kaneko, Y.; Fry, B.; Kaiser, A. E.; Caldwell, T. G.

2017-12-01

The rupture-history of the November 13 2016 MW7.8 Kaikoura earthquake recorded by near- and intermediate-field strong-motion seismometers and 2 high-rate GPS stations reveals a complex cascade of multiple crustal fault rupture. In spite of such complexity, we show that the rupture history of each fault is well approximated by simple kinematic model with uniform slip and rupture velocity. Using 9 faults embedded in a crustal layer 19 km thick, each with a prescribed slip vector and rupture velocity, this model accurately reproduces the displacement waveforms recorded at the near-field strong-motion and GPS stations. This model includes the `Papatea Fault' with a mixed thrust and strike-slip mechanism based on in-situ geological observations with up to 8 m of uplift observed. Although the kinematic model fits the ground-motion at the nearest strong station, it doesn not reproduce the one sided nature of the static deformation field observed geodetically. This suggests a dislocation based approach does not completely capture the mechanical response of the Papatea Fault. The fault system as a whole extends for approximately 150 km along the eastern side of the Marlborough fault system in the South Island of New Zealand. The total duration of the rupture was 74 seconds. The timing and location of each fault's rupture suggests fault interaction and triggering resulting in a northward cascade crustal ruptures. Our model does not require rupture of the underlying subduction interface to explain the data.

Pseudo-dynamic source characterization accounting for rough-fault effects

NASA Astrophysics Data System (ADS)

Galis, Martin; Thingbaijam, Kiran K. S.; Mai, P. Martin

2016-04-01

Broadband ground-motion simulations, ideally for frequencies up to ~10Hz or higher, are important for earthquake engineering; for example, seismic hazard analysis for critical facilities. An issue with such simulations is realistic generation of radiated wave-field in the desired frequency range. Numerical simulations of dynamic ruptures propagating on rough faults suggest that fault roughness is necessary for realistic high-frequency radiation. However, simulations of dynamic ruptures are too expensive for routine applications. Therefore, simplified synthetic kinematic models are often used. They are usually based on rigorous statistical analysis of rupture models inferred by inversions of seismic and/or geodetic data. However, due to limited resolution of the inversions, these models are valid only for low-frequency range. In addition to the slip, parameters such as rupture-onset time, rise time and source time functions are needed for complete spatiotemporal characterization of the earthquake rupture. But these parameters are poorly resolved in the source inversions. To obtain a physically consistent quantification of these parameters, we simulate and analyze spontaneous dynamic ruptures on rough faults. First, by analyzing the impact of fault roughness on the rupture and seismic radiation, we develop equivalent planar-fault kinematic analogues of the dynamic ruptures. Next, we investigate the spatial interdependencies between the source parameters to allow consistent modeling that emulates the observed behavior of dynamic ruptures capturing the rough-fault effects. Based on these analyses, we formulate a framework for pseudo-dynamic source model, physically consistent with the dynamic ruptures on rough faults.

Intrinsic, Transitional, and Extrinsic Morphological Factors Associated With Rupture of Intracranial Aneurysms.

PubMed

Ho, Allen L; Lin, Ning; Frerichs, Kai U; Du, Rose

2015-09-01

As diagnosis and treatment of unruptured intracranial aneurysms continues to increase, management principles remain largely based on size. This is despite mounting evidence that aneurysm location and other morphologic variables could play a role in predicting overall risk of rupture. Morphological parameters can be divided into 3 main groups, those that are intrinsic to the aneurysm, those that are extrinsic to the aneurysm, and those that involve both the aneurysm and surrounding vasculature (transitional). We present an evaluation of intrinsic, transitional, and extrinsic factors and their association with ruptured aneurysms. Using preoperative computed tomographic angiography, we generated 3-dimensional models of aneurysms and their surrounding vasculature with Slicer software. Using univariate and multivariate analyses, we examined the association of intrinsic, transitional, and extrinsic aspects of aneurysm morphology with rupture. Between 2005 and 2013, 227 cerebral aneurysms in 4 locations were evaluated/treated at a single institution, and computed tomographic angiographies of 218 patients (97 unruptured and 130 ruptured) were analyzed. Ruptured aneurysms analyzed were associated with clinical factors of absence of multiple aneurysms and history of no prior rupture, and morphologic factors of greater aspect ratio. On multivariate analysis, aneurysm rupture remained associated with history of no prior rupture, greater flow angle, greater daughter-daughter vessel angle, and smaller parent-daughter vessel angle. By studying the morphology of aneurysms and their surrounding vasculature, we identified several parameters associated with ruptured aneurysms that include intrinsic, transitional, and extrinsic factors of cerebral aneurysms and their surrounding vasculature.

Modeling 3D Dynamic Rupture on Arbitrarily-Shaped faults by Boundary-Conforming Finite Difference Method

NASA Astrophysics Data System (ADS)

Zhu, D.; Zhu, H.; Luo, Y.; Chen, X.

2008-12-01

We use a new finite difference method (FDM) and the slip-weakening law to model the rupture dynamics of a non-planar fault embedded in a 3-D elastic media with free surface. The new FDM, based on boundary- conforming grid, sets up the mapping equations between the curvilinear coordinate and the Cartesian coordinate and transforms irregular physical space to regular computational space; it also employs a higher- order non-staggered DRP/opt MacCormack scheme which is of low dispersion and low dissipation so that the high accuracy and stability of our rupture modeling are guaranteed. Compared with the previous methods, not only we can compute the spontaneous rupture of an arbitrarily shaped fault, but also can model the influence of the surface topography on the rupture process of earthquake. In order to verify the feasibility of this method, we compared our results and other previous results, and found out they matched perfectly. Thanks to the boundary-conforming FDM, problems such as dynamic rupture with arbitrary dip, strike and rake over an arbitrary curved plane can be handled; and supershear or subshear rupture can be simulated with different parameters such as the initial stresses and the critical slip displacement Dc. Besides, our rupture modeling is economical to be implemented owing to its high efficiency and does not suffer from displacement leakage. With the help of inversion data of rupture by field observations, this method is convenient to model rupture processes and seismograms of natural earthquakes.

The evolution of slip pulses within bimaterial interfaces with rupture velocity

NASA Astrophysics Data System (ADS)

Shlomai, H.; Fineberg, J.

2017-12-01

The most general frictional motion in nature involves bimaterial interfaces, when contacting bodies possess different elastic properties. Frictional motion occurs when the contacts composing the interface separating these bodies detach via propagating rupture fronts. Coupling between slip and normal stress variations is unique to bimaterial interfaces. Here we use high speed simultaneous measurements of slip velocities, real contact area and stresses to explicitly reveal this bimaterial coupling and its role in determining different classes of rupture modes and their structures. Our experiments study the rupture of a spatially extended interface formed by brittle plastics whose shear wave speeds differ by 30%. Any slip within a bimaterial interface will break the stress symmetry across the interface. One important result of this is that local values of normal stress variations at the interface couple to interface slip, `bimaterial coupling'. The sign of the coupling depends on the front propagation direction. When we consider ruptures propagating in the direction of motion of the more compliant material, the `positive' direction, slip reduces the normal stress. We focus on this direction. We show that, in this direction, interface ruptures develop from crack-like behavior at low rupture velocities, whose structure corresponds to theoretical predictions: As the ruptures accelerate towards their asymptotic speed, the structures of the strain and stress fields near the rupture tip deviate significantly from this crack-like form, and systematically sharpen to a pulse-like rupture mode called slip-pulses. We conclude with a description of slip-pulse properties.

Endocytic vesicle rupture is a conserved mechanism of cellular invasion by amyloid proteins.

PubMed

Flavin, William P; Bousset, Luc; Green, Zachary C; Chu, Yaping; Skarpathiotis, Stratos; Chaney, Michael J; Kordower, Jeffrey H; Melki, Ronald; Campbell, Edward M

2017-10-01

Numerous pathological amyloid proteins spread from cell to cell during neurodegenerative disease, facilitating the propagation of cellular pathology and disease progression. Understanding the mechanism by which disease-associated amyloid protein assemblies enter target cells and induce cellular dysfunction is, therefore, key to understanding the progressive nature of such neurodegenerative diseases. In this study, we utilized an imaging-based assay to monitor the ability of disease-associated amyloid assemblies to rupture intracellular vesicles following endocytosis. We observe that the ability to induce vesicle rupture is a common feature of α-synuclein (α-syn) assemblies, as assemblies derived from WT or familial disease-associated mutant α-syn all exhibited the ability to induce vesicle rupture. Similarly, different conformational strains of WT α-syn assemblies, but not monomeric or oligomeric forms, efficiently induced vesicle rupture following endocytosis. The ability to induce vesicle rupture was not specific to α-syn, as amyloid assemblies of tau and huntingtin Exon1 with pathologic polyglutamine repeats also exhibited the ability to induce vesicle rupture. We also observe that vesicles ruptured by α-syn are positive for the autophagic marker LC3 and can accumulate and fuse into large, intracellular structures resembling Lewy bodies in vitro. Finally, we show that the same markers of vesicle rupture surround Lewy bodies in brain sections from PD patients. These data underscore the importance of this conserved endocytic vesicle rupture event as a damaging mechanism of cellular invasion by amyloid assemblies of multiple neurodegenerative disease-associated proteins, and suggest that proteinaceous inclusions such as Lewy bodies form as a consequence of continued fusion of autophagic vesicles in cells unable to degrade ruptured vesicles and their amyloid contents.

Rupture Following Biceps-to-Triceps Tendon Transfer in Adolescents and Young Adults With Spinal Cord Injury:

PubMed Central

Merenda, Lisa A.; Rutter, Laure; Curran, Kimberly; Kozin, Scott H.

2012-01-01

Background: Tendon transfer surgery can restore elbow extension in approximately 70% of persons with tetraplegia and often results in antigravity elbow extension strength. However, we have noted an almost 15% rupture/attenuation rate. Objective: This investigation was conducted to analyze potential causes in adolescents/young adults with spinal cord injury (SCI) who experienced tendon rupture or attenuation after biceps-to-triceps transfer. Methods: Medical charts of young adults with SCI who underwent biceps-to-triceps transfer and experienced tendon rupture or attenuation were reviewed. Data collected by retrospective chart review included general demographics, surgical procedure(s), use and duration of antibiotic treatment, time from tendon transfer surgery to rupture/attenuation, and method of diagnosis. Results: Twelve subjects with tetraplegia (mean age, 19 years) who underwent biceps-to-triceps reconstruction with subsequent tendon rupture or attenuation were evaluated. Mean age at time of tendon transfer was 18 years (range, 14-21 years). A fluoroquinolone was prescribed for 42% (n=5) of subjects. Tendon rupture was noted in 67% (n=8), and attenuation was noted in 33% (n=4). Average length of time from surgery to tendon rupture/attenuation was 5.7 months (range, 3-10 months). Conclusion: Potential contributing causes of tendon rupture/attenuation after transfer include surgical technique, rehabilitation, co-contraction of the transfer, poor patient compliance, and medications. In this cohort, 5 subjects were prescribed fluoroquinolones that have a US Food and Drug Administration black box concerning tendon ruptures. Currently, all candidates for upper extremity tendon transfer reconstruction are counseled on the effects of fluoroquinolones and the potential risk for tendon rupture. PMID:23459326

Macroscopic Source Properties from Dynamic Rupture Styles in Plastic Media

NASA Astrophysics Data System (ADS)

Gabriel, A.; Ampuero, J. P.; Dalguer, L. A.; Mai, P. M.

2011-12-01

High stress concentrations at earthquake rupture fronts may generate an inelastic off-fault response at the rupture tip, leading to increased energy absorption in the damage zone. Furthermore, the induced asymmetric plastic strain field in in-plane rupture modes may produce bimaterial interfaces that can increase radiation efficiency and reduce frictional dissipation. Off-fault inelasticity thus plays an important role for realistic predictions of near-fault ground motion. Guided by our previous studies in the 2D elastic case, we perform rupture dynamics simulations including rate-and-state friction and off-fault plasticity to investigate the effects on the rupture properties. We quantitatively analyze macroscopic source properties for different rupture styles, ranging from cracks to pulses and subshear to supershear ruptures, and their transitional mechanisms. The energy dissipation due to off-fault inelasticity modifies the conditions to obtain each rupture style and alters macroscopic source properties. We examine apparent fracture energy, rupture and healing front speed, peak slip and peak slip velocity, dynamic stress drop and size of the process and plastic zones, slip and plastic seismic moment, and their connection to ground motion. This presentation focuses on the effects of rupture style and off-fault plasticity on the resulting ground motion patterns, especially on characteristic slip velocity function signatures and resulting seismic moments. We aim at developing scaling rules for equivalent elastic models, as function of background stress and frictional parameters, that may lead to improved "pseudo-dynamic" source parameterizations for ground-motion calculation. Moreover, our simulations provide quantitative relations between off-fault energy dissipation and macroscopic source properties. These relations might provide a self-consistent theoretical framework for the study of the earthquake energy balance based on observable earthquake source parameters.

Retrieving rupture history using waveform inversions in time sequence

NASA Astrophysics Data System (ADS)

Yi, L.; Xu, C.; Zhang, X.

2017-12-01

The rupture history of large earthquakes is generally regenerated using the waveform inversion through utilizing seismological waveform records. In the waveform inversion, based on the superposition principle, the rupture process is linearly parameterized. After discretizing the fault plane into sub-faults, the local source time function of each sub-fault is usually parameterized using the multi-time window method, e.g., mutual overlapped triangular functions. Then the forward waveform of each sub-fault is synthesized through convoluting the source time function with its Green function. According to the superposition principle, these forward waveforms generated from the fault plane are summarized in the recorded waveforms after aligning the arrival times. Then the slip history is retrieved using the waveform inversion method after the superposing of all forward waveforms for each correspond seismological waveform records. Apart from the isolation of these forward waveforms generated from each sub-fault, we also realize that these waveforms are gradually and sequentially superimposed in the recorded waveforms. Thus we proposed a idea that the rupture model is possibly detachable in sequent rupture times. According to the constrained waveform length method emphasized in our previous work, the length of inverted waveforms used in the waveform inversion is objectively constrained by the rupture velocity and rise time. And one essential prior condition is the predetermined fault plane that limits the duration of rupture time, which means the waveform inversion is restricted in a pre-set rupture duration time. Therefore, we proposed a strategy to inverse the rupture process sequentially using the progressively shift rupture times as the rupture front expanding in the fault plane. And we have designed a simulation inversion to test the feasibility of the method. Our test result shows the prospect of this idea that requiring furthermore investigation.

Increased 18F-FDG Uptake Is Predictive of Rupture in a Novel Rat Abdominal Aortic Aneurysm Rupture Model

PubMed Central

English, Sean J.; Piert, Morand R.; Diaz, Jose A.; Gordon, David; Ghosh, Abhijit; D'Alecy, Louis G.; Whitesall, Steven E.; Sharma, Ashish K.; DeRoo, Elise P.; Watt, Tessa; Su, Gang; Henke, Peter K.; Eliason, Jonathan L.; Ailawadi, Gorav; Upchurch, Gilbert R.

2015-01-01

Objective To determine whether 18F-fluorodeoxyglucose (18F-FDG) micro–positron emission tomography (micro-PET) can predict abdominal aortic aneurysm (AAA) rupture. Background An infrarenal AAA model is needed to study inflammatory mechanisms that drive rupture. 18F-FDG PET can detect vascular inflammation in animal models and patients. Methods After exposing Sprague-Dawley rats to intra-aortic porcine pancreatic elastase (PPE) (12 U/mL), AAA rupture was induced by daily, subcutaneous, β-aminopropionitrile (BAPN, 300 mg/kg, N = 24) administration. Negative control AAA animals (N = 15) underwent daily saline subcutaneous injection after PPE exposure. BAPN-exposed animals that did not rupture served as positive controls [nonruptured AAA (NRAAA) 14d, N = 9]. Rupture was witnessed using radiotelemetry. Maximum standard uptakes for 18F-FDG micro-PET studies were determined. Aortic wall PAI-1, uPA, and tPA concentrations were determined by western blot analyses. Interleukin (IL)-1β, IL-6, IL-10, and MIP-2 were determined by Bio-Plex bead array. Neutrophil and macrophage populations per high-power field were quantified. Matrix metalloproteinase (MMP) activities were determined by zymography. Results When comparing ruptured AAA (RAAA) to NRAAA 14d animals, increased focal 18F-FDG uptakes were detected at subsequent sites of rupture (P = 0.03). PAI-1 expression was significantly less in RAAA tissue (P = 0.01), with comparable uPA and decreased tPA levels (P = 0.02). IL-1β (P = 0.04), IL-6 (P = 0.001), IL-10 (P = 0.04), and MIP-2 (P = 0.02)expression, neutrophil (P = 0.02) and macrophage presence (P = 0.002), and MMP9 (P < 0.0001) activity were increased in RAAA tissue. Conclusions With this AAA rupture model, increased prerupture 18F-FDG uptake on micro-PET imaging was associated with increased inflammation in the ruptured AAA wall. 18F-FDG PET imaging may be used to monitor inflammatory changes before AAA rupture. PMID:24651130

Aetiology and pathogenesis of cranial cruciate ligament rupture in cats by histological examination.

PubMed

Wessely, Marlis; Reese, Sven; Schnabl-Feichter, Eva

2017-06-01

Objectives The aim of this study was to examine histologically intact and ruptured cranial cruciate ligaments in cats, in order to evaluate whether degeneration is a prerequisite for rupture. Methods We performed a histological examination of 50 intact and 19 ruptured cranial cruciate ligaments in cadaver or client-owned cats, respectively, using light microscopy. Cats with stifle pathology were further divided into five age groups in order to investigate the relationship of changes in the ligament with lifespan. Cats with ruptured cranial cruciate ligaments were divided into two groups according to medical history (with presumed history of trauma or without any known history of trauma) in order to investigate the relationship of ligament rupture with a traumatic event. Data from 200 healthy cats were selected randomly and reviewed to make a statistical comparison of cats with and without cranial cruciate ligament rupture (reference group). Results On histological examination, the intact cranial cruciate ligaments showed basic parallel arrangement of the collagen fibres, with no relation to age. While cats of a more advanced age showed fibrocartilage in the middle of the cranial cruciate ligament - a likely physiological reaction to compression forces over the lifespan - degenerative changes within the fibrocartilage were absent in all cases, regardless of age or rupture status. Cats suffering from cranial cruciate ligament rupture without history of trauma were significantly older than cats in the reference group. Conclusions and relevance This study showed that differentiation of fibrocartilage in the middle of the cranial cruciate ligament is likely a physiological reaction to compressive forces and not a degenerative change associated with greater risk of rupture in advanced age. This finding in cats is distinct from the known decrease in differentiation of fibrocartilage in dogs with cranial cruciate ligament rupture. Furthermore, the histological examination of cats revealed no other signs of degeneration in the cranial cruciate ligaments. Thus, degeneration is likely not an aetiological factor for cranial cruciate ligament rupture in cats.

Effect of position, time in the season, and playing surface on Achilles tendon ruptures in NFL games: a 2009-10 to 2016-17 review.

PubMed

Krill, Michael K; Borchers, James R; Hoffman, Joshua T; Krill, Matthew L; Hewett, Timothy E

2017-09-01

Achilles tendon (AT) ruptures are a potentially career-altering and ending injury. Achilles tendon ruptures have a below average return-to-play rate compared to other common orthopaedic procedures for National Football League (NFL) players. The objective of this study was to monitor the incidence and injury rates (IR) of AT ruptures that occurred during the regular season in order to evaluate the influence of player position, time of injury, and playing surface on rupture rates. A thorough online review was completed to identify published injury reports and public information regarding AT ruptures sustained during regular season and post-season games in the National Football League (NFL) during the 2009-10 to 2016-17 seasons. Team schedules, player position details and stadium information was used to determine period of the season of injury and playing surface. IRs were calculated per 100 team games (TG). Injury rate ratios (IRR) were utilized to compare IRs. During eight monitored seasons, there were 44 AT ruptures in NFL games. A majority of AT ruptures were sustained in the first eight games of the regular season (n = 32, 72.7%). There was a significant rate difference for the first and second four-game segments of the regular season compared to the last two four-game segments of the regular season. Defensive players suffered a majority of AT ruptures (n = 32, 72.7%). The IR on grass was 1.00 per 100 TG compared to 1.08 per 100 TG on artificial turf (IRR: 0.93, p = .80). A significant increase in AT ruptures occurred in the first and second four game segments of the regular season compared to the last two-four game segments of the regular season. Defensive players suffered a majority of AT ruptures compared to offensive or specialist players. There was no difference between AT rupture rates and playing surface in games.

The 1994 Northridge, California, earthquake: Investigation of rupture velocity, risetime, and high-frequency radiation

USGS Publications Warehouse

Hartzell, S.; Liu, P.; Mendoza, C.

1996-01-01

A hybrid global search algorithm is used to solve the nonlinear problem of calculating slip amplitude, rake, risetime, and rupture time on a finite fault. Thirty-five strong motion velocity records are inverted by this method over the frequency band from 0.1 to 1.0 Hz for the Northridge earthquake. Four regions of larger-amplitude slip are identified: one near the hypocenter at a depth of 17 km, a second west of the hypocenter at about the same depth, a third updip from the hypocenter at a depth of 10 km, and a fourth updip from the hypocenter and to the northwest. The results further show an initial fast rupture with a velocity of 2.8 to 3.0 km/s followed by a slow termination of the rupture with velocities of 2.0 to 2.5 km/s. The initial energetic rupture phase lasts for 3 s, extending out 10 km from the hypocenter. Slip near the hypocenter has a short risetime of 0.5 s, which increases to 1.5 s for the major slip areas removed from the hypocentral region. The energetic rupture phase is also shown to be the primary source of high-frequency radiation (1-15 Hz) by an inversion of acceleration envelopes. The same global search algorithm is used in the envelope inversion to calculate high-frequency radiation intensity on the fault and rupture time. The rupture timing from the low- and high-frequency inversions is similar, indicating that the high frequencies are produced primarily at the mainshock rupture front. Two major sources of high-frequency radiation are identified within the energetic rupture phase, one at the hypocenter and another deep source to the west of the hypocenter. The source at the hypocenter is associated with the initiation of rupture and the breaking of a high-stress-drop asperity and the second is associated with stopping of the rupture in a westerly direction.

Broadband Rupture Process of the 2001 Kunlun Fault (Mw 7.8) Earthquake

NASA Astrophysics Data System (ADS)

Antolik, M.; Abercrombie, R.; Ekstrom, G.

2003-04-01

We model the source process of the 14 November, 2001 Kunlun fault earthquake using broadband body waves from the Global Digital Seismographic Network (P, SH) and both point-source and distributed slip techniques. The point-source mechanism technique is a non-linear iterative inversion that solves for focal mechanism, moment rate function, depth, and rupture directivity. The P waves reveal a complex rupture process for the first 30 s, with smooth unilateral rupture toward the east along the Kunlun fault accounting for the remainder of the 120 s long rupture. The obtained focal mechanism for the main portion of the rupture is (strike=96o, dip=83o, rake=-8o) which is consistent with both the Harvard CMT solution and observations of the surface rupture. The seismic moment is 5.29×1020 Nm and the average rupture velocity is ˜3.5 km/s. However, the initial portion of the P waves cannot be fit at all with this mechanism. A strong pulse visible in the first 20 s can only be matched with an oblique-slip subevent (MW ˜ 6.8-7.0) involving a substantial normal faulting component, but the nodal planes of this mechanism are not well constrained. The first-motion polarities of the P waves clearly require a strike mechanism with a similar orientation as the Kunlun fault. Field observations of the surface rupture (Xu et al., SRL, 73, No. 6) reveal a small 26 km-long strike-slip rupture at the far western end (90.5o E) with a 45-km long gap and extensional step-over between this rupture and the main Kunlun fault rupture. We hypothesize that the initial fault break occurred on this segment, with release of the normal faulting energy as a continuous rupture through the extensional step, enabling transfer of the slip to the main Kunlun fault. This process is similar to that which occurred during the 2002 Denali fault (MW 7.9) earthquake sequence except that 11 days elapsed between the October 23 (M_W 6.7) foreshock and the initial break of the Denali earthquake along a thrust fault.

Toward tsunami early warning system in Indonesia by using rapid rupture durations estimation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Madlazim

2012-06-20

Indonesia has Indonesian Tsunami Early Warning System (Ina-TEWS) since 2008. The Ina-TEWS has used automatic processing on hypocenter; Mwp, Mw (mB) and Mj. If earthquake occurred in Ocean, depth < 70 km and magnitude > 7, then Ina-TEWS announce early warning that the earthquake can generate tsunami. However, the announcement of the Ina-TEWS is still not accuracy. Purposes of this research are to estimate earthquake rupture duration of large Indonesia earthquakes that occurred in Indian Ocean, Java, Timor sea, Banda sea, Arafura sea and Pasific ocean. We analyzed at least 330 vertical seismogram recorded by IRIS-DMC network using a directmore » procedure for rapid assessment of earthquake tsunami potential using simple measures on P-wave vertical seismograms on the velocity records, and the likelihood that the high-frequency, apparent rupture duration, T{sub dur}. T{sub dur} can be related to the critical parameters rupture length (L), depth (z), and shear modulus ({mu}) while T{sub dur} may be related to wide (W), slip (D), z or {mu}. Our analysis shows that the rupture duration has a stronger influence to generate tsunami than Mw and depth. The rupture duration gives more information on tsunami impact, Mo/{mu}, depth and size than Mw and other currently used discriminants. We show more information which known from the rupture durations. The longer rupture duration, the shallower source of the earthquake. For rupture duration greater than 50 s, the depth less than 50 km, Mw greater than 7, the longer rupture length, because T{sub dur} is proportional L and greater Mo/{mu}. Because Mo/{mu} is proportional L. So, with rupture duration information can be known information of the four parameters. We also suggest that tsunami potential is not directly related to the faulting type of source and for events that have rupture duration greater than 50 s, the earthquakes generated tsunami. With available real-time seismogram data, rapid calculation, rupture duration discriminant can be completed within 4-5 min after an earthquake occurs and thus can aid in effective, accuracy and reliable tsunami early warning for Indonesia region.« less

Geologic and structural controls on rupture zone fabric: A field-based study of the 2010 Mw 7.2 El Mayor–Cucapah earthquake surface rupture

USGS Publications Warehouse

Teran, Orlando; Fletcher, John L.; Oskin, Michael; Rockwell, Thomas; Hudnut, Kenneth W.; Spelz, Ronald; Akciz, Sinan; Hernandez-Flores, Ana Paula; Morelan, Alexander

2015-01-01

We systematically mapped (scales >1:500) the surface rupture of the 4 April 2010 Mw (moment magnitude) 7.2 El Mayor-Cucapah earthquake through the Sierra Cucapah (Baja California, northwestern Mexico) to understand how faults with similar structural and lithologic characteristics control rupture zone fabric, which is here defined by the thickness, distribution, and internal configuration of shearing in a rupture zone. Fault zone thickness and master fault dip are strongly correlated with many parameters of rupture zone fabric. Wider fault zones produce progressively wider rupture zones and both of these parameters increase systematically with decreasing dip of master faults, which varies from 20° to 90° in our dataset. Principal scarps that accommodate more than 90% of the total coseismic slip in a given transect are only observed in fault sections with narrow rupture zones (<25 m). As rupture zone thickness increases, the number of scarps in a given transect increases, and the scarp with the greatest relative amount of coseismic slip decreases. Rupture zones in previously undeformed alluvium become wider and have more complex arrangements of secondary fractures with oblique slip compared to those with pure normal dip-slip or pure strike-slip. Field relations and lidar (light detection and ranging) difference models show that as magnitude of coseismic slip increases from 0 to 60 cm, the links between kinematically distinct fracture sets increase systematically to the point of forming a throughgoing principal scarp. Our data indicate that secondary faults and penetrative off-fault strain continue to accommodate the oblique kinematics of coseismic slip after the formation of a thoroughgoing principal scarp. Among the widest rupture zones in the Sierra Cucapah are those developed above buried low angle faults due to the transfer of slip to widely distributed steeper faults, which are mechanically more favorably oriented. The results from this study show that the measureable parameters that define rupture zone fabric allow for testing hypotheses concerning the mechanics and propagation of earthquake ruptures, as well as for siting and designing facilities to be constructed in regions near active faults.

Three-Dimensional Dynamic Rupture in Brittle Solids and the Volumetric Strain Criterion

NASA Astrophysics Data System (ADS)

Uenishi, K.; Yamachi, H.

2017-12-01

As pointed out by Uenishi (2016 AGU Fall Meeting), source dynamics of ordinary earthquakes is often studied in the framework of 3D rupture in brittle solids but our knowledge of mechanics of actual 3D rupture is limited. Typically, criteria derived from 1D frictional observations of sliding materials or post-failure behavior of solids are applied in seismic simulations, and although mode-I cracks are frequently encountered in earthquake-induced ground failures, rupture in tension is in most cases ignored. Even when it is included in analyses, the classical maximum principal tensile stress rupture criterion is repeatedly used. Our recent basic experiments of dynamic rupture of spherical or cylindrical monolithic brittle solids by applying high-voltage electric discharge impulses or impact loads have indicated generation of surprisingly simple and often flat rupture surfaces in 3D specimens even without the initial existence of planes of weakness. However, at the same time, the snapshots taken by a high-speed digital video camera have shown rather complicated histories of rupture development in these 3D solid materials, which seem to be difficult to be explained by, for example, the maximum principal stress criterion. Instead, a (tensile) volumetric strain criterion where the volumetric strain (dilatation or the first invariant of the strain tensor) is a decisive parameter for rupture seems more effective in computationally reproducing the multi-directionally propagating waves and rupture. In this study, we try to show the connection between this volumetric strain criterion and other classical rupture criteria or physical parameters employed in continuum mechanics, and indicate that the criterion has, to some degree, physical meanings. First, we mathematically illustrate that the criterion is equivalent to a criterion based on the mean normal stress, a crucial parameter in plasticity. Then, we mention the relation between the volumetric strain criterion and the failure envelope of the Mohr-Coulomb criterion that describes shear-related rupture. The critical value of the volumetric strain for rupture may be controlled by the apparent cohesion and apparent angle of internal friction of the Mohr-Coulomb criterion.

Microvessel rupture induced by high-intensity therapeutic ultrasound-a study of parameter sensitivity in a simple in vivo model.

PubMed

Kim, Yeonho; Nabili, Marjan; Acharya, Priyanka; Lopez, Asis; Myers, Matthew R

2017-01-01

Safety analyses of transcranial therapeutic ultrasound procedures require knowledge of the dependence of the rupture probability and rupture time upon sonication parameters. As previous vessel-rupture studies have concentrated on a specific set of exposure conditions, there is a need for more comprehensive parametric studies. Probability of rupture and rupture times were measured by exposing the large blood vessel of a live earthworm to high-intensity focused ultrasound pulse trains of various characteristics. Pressures generated by the ultrasound transducers were estimated through numerical solutions to the KZK (Khokhlov-Zabolotskaya-Kuznetsov) equation. Three ultrasound frequencies (1.1, 2.5, and 3.3 MHz) were considered, as were three pulse repetition frequencies (1, 3, and 10 Hz), and two duty factors (0.0001, 0.001). The pressures produced ranged from 4 to 18 MPa. Exposures of up to 10 min in duration were employed. Trials were repeated an average of 11 times. No trends as a function of pulse repetition rate were identifiable, for either probability of rupture or rupture time. Rupture time was found to be a strong function of duty factor at the lower pressures; at 1.1 MHz the rupture time was an order of magnitude lower for the 0.001 duty factor than the 0.0001. At moderate pressures, the difference between the duty factors was less, and there was essentially no difference between duty factors at the highest pressure. Probability of rupture was not found to be a strong function of duty factor. Rupture thresholds were about 4 MPa for the 1.1 MHz frequency, 7 MPa at 3.3 MHz, and 11 MPa for the 2.5 MHz, though the pressure value at 2.5 MHz frequency will likely be reduced when steep-angle corrections are accounted for in the KZK model used to estimate pressures. Mechanical index provided a better collapse of the data (less separation of the curves pertaining to the different frequencies) than peak negative pressure, for both probability of rupture and rupture time. The results provide a database with which investigations in more complex animal models can be compared, potentially establishing trends by which bioeffects in human vessels can be estimated.

Evaluating the Possibility of a joint San Andreas-Imperial Fault Rupture in the Salton Trough Region

NASA Astrophysics Data System (ADS)

Kyriakopoulos, C.; Oglesby, D. D.; Meltzner, A. J.; Rockwell, T. K.

2016-12-01

A geodynamic investigation of possible earthquakes in a given region requires both field data and numerical simulations. In particular, the investigation of past earthquakes is also a fundamental part of understanding the earthquake potential of the Salton Trough region. Geological records from paleoseismic trenches inform us of past ruptures (length, magnitude, timing), while dynamic rupture models allow us to evaluate numerically the mechanics of such earthquakes. The two most recent events (Mw 6.4 1940 and Mw 6.9 1979) on the Imperial fault (IF) both ruptured up to the northern end of the mapped fault, giving the impression that rupture doesn't propagate further north. This result is supported by small displacements, 20 cm, measured at the Dogwood site near the end of the mapped rupture in each event. However, 3D paleoseismic data from the same site corresponding to the most recent pre-1940 event (1710 CE) and 5th (1635 CE) and 6th events back revealed up to 1.5 m of slip in those events. Since we expect the surface displacement to decrease toward the termination of a rupture, we postulate that in these earlier cases the rupture propagated further north than in 1940 or 1979. Furthermore, paleoseismic data from the Coachella site (Philibosian et al., 2011) on the San Andreas fault (SAF) indicates slip events ca. 1710 CE and 1588-1662 CE. In other words, the timing of two large paleoseismic displacements on the IF cannot be distinguished from the timing of the two most recent events on the southern SAF, leaving a question: is it possible to have through-going rupture in the Salton Trough? We investigate this question through 3D dynamic finite element rupture modeling. In our work, we considered two scenarios: rupture initiated on the IF propagating northward, and rupture initiated on the SAF propagating southward. Initial results show that, in the first case, rupture propagates north of the mapped northern terminus of the IF only under certain pre-stress conditions, such as values of the seismic parameter S = 0.45 to 2.0, and tends to stop for S = 2.5. If rupture initiates in the north on the SAF, we find that it is easier for it to propagate across the entire stepover region. The results have implications for potential earthquakes in the region, with the possibility of a preferred direction of rupture propagation through the stepover.

Rupture process of the 2009 L'Aquila, central Italy, earthquake, from the separate and joint inversion of Strong Motion, GPS and DInSAR data.

NASA Astrophysics Data System (ADS)

Cirella, A.; Piatanesi, A.; Tinti, E.; Chini, M.; Cocco, M.

2012-04-01

In this study, we investigate the rupture history of the April 6th 2009 (Mw 6.1) L'Aquila normal faulting earthquake by using a nonlinear inversion of strong motion, GPS and DInSAR data. We use a two-stage non-linear inversion technique. During the first stage, an algorithm based on the heat-bath simulated annealing generates an ensemble of models that efficiently sample the good data-fitting regions of parameter space. In the second stage the algorithm performs a statistical analysis of the ensemble providing us the best-fitting model, the average model, the associated standard deviation and coefficient of variation. This technique, rather than simply looking at the best model, extracts the most stable features of the earthquake rupture that are consistent with the data and gives an estimate of the variability of each model parameter. The application to the 2009 L'Aquila main-shock shows that both the separate and joint inversion solutions reveal a complex rupture process and a heterogeneous slip distribution. Slip is concentrated in two main asperities: a smaller shallow patch of slip located up-dip from the hypocenter and a second deeper and larger asperity located southeastward along strike direction. The key feature of the source process emerging from our inverted models concerns the rupture history, which is characterized by two distinct stages. The first stage begins with rupture initiation and with a modest moment release lasting nearly 0.9 seconds, which is followed by a sharp increase in slip velocity and rupture speed located 2 km up-dip from the nucleation. During this first stage the rupture front propagated up-dip from the hypocenter at relatively high (˜ 4.0 km/s), but still sub-shear, rupture velocity. The second stage starts nearly 2 seconds after nucleation and it is characterized by the along strike rupture propagation. The largest and deeper asperity fails during this stage of the rupture process. The rupture velocity is larger in the up-dip than in the along-strike direction. The up-dip and along-strike rupture propagation are separated in time and associated with a Mode II and a Mode III crack, respectively. Our results show that the 2009 L'Aquila earthquake featured a very complex rupture, with strong spatial and temporal heterogeneities suggesting a strong frictional and/or structural control of the rupture process.

Etiology and pathophysiology of tendon ruptures in sports.

PubMed

Kannus, P; Natri, A

1997-04-01

Of all spontaneous tendon ruptures, complete Achilles tendon tears are most closely associated with sports activities (1-3). Schönbauer (3) reported that 75% of all ruptures of the Achilles tendon are related to sports. In Plecko & Passl (2) the number was 60%. In our material of 430 cases, the number of sports-related Achilles ruptures was very similar (62%), while only 2% of ruptures of other tendons were sports-related (P < 0.001) (1). Also, the majority of Achilles reruptures occurred in sports. The ruptures occurred most often in soccer (34%), track and field (16%) and basketball (14%). The distribution of Achilles ruptures according to different sports varies considerably from country to country, according to the national sport traditions. For example, in northern and middle Europe, soccer, tennis, track and field, indoor ball games, downhill skiing, and gymnastics are the most common; and in North America, football, basketball, baseball, tennis and downhill skiing dominate the statistics (1, 2, 4). In sports, some Achilles ruptures are not spontaneous or degeneration-induced but may occur as a consequence of the remarkably high forces that are involved in the performance (2). Ruptures in the high jump or triple jump are good examples. In such cases, failure in the neuromuscular protective mechanisms due to fatigue or disturbed co-ordination can frequently be found. The spontaneous complete rupture of the supraspinatus tendon of the rotator cuff does not occur very frequently in sports. Those sports that include high-energy throwing movements, such as American and Finnish baseball, American football, rugby and discuss and javelin throwing, may, however, produce this injury. Partial tears and inflammations of the rotator cuff complex are much more frequent in throwing sports. The complete rupture of the proximal long head of the biceps brachii tendon is rare among competitive and recreational athletes. In our material, under 2% of these ruptures were associated with sports activities (5). The rupture (avulsion) of the distal tendon of the biceps muscle is rare. In sports, gymnastics, body building and weight lifting have been said to be able to produce this injury (6). In general, complete ruptures of the quadriceps tendon and the patellar tendon occur most often in older individuals. In our study, the mean age of these patients was 65 years (5). However, these injuries do also occur in younger age groups, especially in athletes. In athletes, the rupture most frequently occurs in high-power sports events, such as high jump, basketball and weight lifting, at the age of 15-30 years. A chronic-patellar apicitis (jumper's knee) may predispose rupture of the tendon (7). As is the case with the rotator cuff complex, overuse inflammation and partial tears of the quadriceps and patellar tendons are one of the most characteristic athletic injuries. Complete spontaneous ruptures of other tendons in sports are rare, although the literature does provide case studies from almost every tendon the human body possesses (8-18).

Identification of tissues and patterning events required for distinct steps in early migration of zebrafish primordial germ cells.

PubMed

Weidinger, G; Wolke, U; Köprunner, M; Klinger, M; Raz, E

1999-12-01

In many organisms, the primordial germ cells have to migrate from the position where they are specified towards the developing gonad where they generate gametes. Extensive studies of the migration of primordial germ cells in Drosophila, mouse, chick and Xenopus have identified somatic tissues important for this process and demonstrated a role for specific molecules in directing the cells towards their target. In zebrafish, a unique situation is found in that the primordial germ cells, as marked by expression of vasa mRNA, are specified in random positions relative to the future embryonic axis. Hence, the migrating cells have to navigate towards their destination from various starting positions that differ among individual embryos. Here, we present a detailed description of the migration of the primordial germ cells during the first 24 hours of wild-type zebrafish embryonic development. We define six distinct steps of migration bringing the primordial germ cells from their random positions before gastrulation to form two cell clusters on either side of the midline by the end of the first day of development. To obtain information on the origin of the positional cues provided to the germ cells by somatic tissues during their migration, we analyzed the migration pattern in mutants, including spadetail, swirl, chordino, floating head, cloche, knypek and no isthmus. In mutants with defects in axial structures, paraxial mesoderm or dorsoventral patterning, we find that certain steps of the migration process are specifically affected. We show that the paraxial mesoderm is important for providing proper anteroposterior information to the migrating primordial germ cells and that these cells can respond to changes in the global dorsoventral coordinates. In certain mutants, we observe accumulation of ectopic cells in different regions of the embryo. These ectopic cells can retain both morphological and molecular characteristics of primordial germ cells, suggesting that, in zebrafish at the early stages tested, the vasa-expressing cells are committed to the germ cell lineage.

Zebrafish embryos as a screen for DNA methylation modifications after compound exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bouwmeester, Manon C.; Ruiter, Sander; Lommelaars, Tobias

Modified epigenetic programming early in life is proposed to underlie the development of an adverse adult phenotype, known as the Developmental Origins of Health and Disease (DOHaD) concept. Several environmental contaminants have been implicated as modifying factors of the developing epigenome. This underlines the need to investigate this newly recognized toxicological risk and systematically screen for the epigenome modifying potential of compounds. In this study, we examined the applicability of the zebrafish embryo as a screening model for DNA methylation modifications. Embryos were exposed from 0 to 72 h post fertilization (hpf) to bisphenol-A (BPA), diethylstilbestrol, 17α-ethynylestradiol, nickel, cadmium, tributyltin,more » arsenite, perfluoroctanoic acid, valproic acid, flusilazole, 5-azacytidine (5AC) in subtoxic concentrations. Both global and site-specific methylation was examined. Global methylation was only affected by 5AC. Genome wide locus-specific analysis was performed for BPA exposed embryos using Digital Restriction Enzyme Analysis of Methylation (DREAM), which showed minimal wide scale effects on the genome, whereas potential informative markers were not confirmed by pyrosequencing. Site-specific methylation was examined in the promoter regions of three selected genes vasa, vtg1 and cyp19a2, of which vasa (ddx4) was the most responsive. This analysis distinguished estrogenic compounds from metals by direction and sensitivity of the effect compared to embryotoxicity. In conclusion, the zebrafish embryo is a potential screening tool to examine DNA methylation modifications after xenobiotic exposure. The next step is to examine the adult phenotype of exposed embryos and to analyze molecular mechanisms that potentially link epigenetic effects and altered phenotypes, to support the DOHaD hypothesis. - Highlights: • Compound induced effects on DNA methylation in zebrafish embryos • Global methylation not an informative biomarker • Minimal genome wide site specific changes as detected with DREAM • Compound/class specific effects suggested by pyrosequence of specific targets • Zebrafish embryo may be a screening model for epigenetic effects.« less

Functional transient receptor potential vanilloid 1 and transient receptor potential vanilloid 4 channels along different segments of the renal vasculature.

PubMed

Chen, L; Kaßmann, M; Sendeski, M; Tsvetkov, D; Marko, L; Michalick, L; Riehle, M; Liedtke, W B; Kuebler, W M; Harteneck, C; Tepel, M; Patzak, A; Gollasch, M

2015-02-01

Transient receptor potential vanilloid 1 (TRPV1) and vanilloid 4 (TRPV4) cation channels have been recently identified to promote endothelium-dependent relaxation of mouse mesenteric arteries. However, the role of TRPV1 and TRPV4 in the renal vasculature is largely unknown. We hypothesized that TRPV1/4 plays a role in endothelium-dependent vasodilation of renal blood vessels. We studied the distribution of functional TRPV1/4 along different segments of the renal vasculature. Mesenteric arteries were studied as control vessels. The TRPV1 agonist capsaicin relaxed mouse mesenteric arteries with an EC50 of 25 nm, but large mouse renal arteries or rat descending vasa recta only at >100-fold higher concentrations. The vasodilatory effect of capsaicin in the low-nanomolar concentration range was endothelium-dependent and absent in vessels of Trpv1 -/- mice. The TRPV4 agonist GSK1016790A relaxed large conducting renal arteries, mesenteric arteries and vasa recta with EC50 of 18, 63 nm and ~10 nm respectively. These effects were endothelium-dependent and inhibited by a TRPV4 antagonist, AB159908 (10 μm). Capsaicin and GSK1016790A produced vascular dilation in isolated mouse perfused kidneys with EC50 of 23 and 3 nm respectively. The capsaicin effects were largely reduced in Trpv1 -/- kidneys, and the effects of GSK1016790A were inhibited in Trpv4 -/- kidneys. Our results demonstrate that two TRPV channels have unique sites of vasoregulatory function in the kidney with functional TRPV1 having a narrow, discrete distribution in the resistance vasculature and TRPV4 having more universal, widespread distribution along different vascular segments. We suggest that TRPV1/4 channels are potent therapeutic targets for site-specific vasodilation in the kidney. © 2014 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Mathematical modeling of atherosclerotic plaque destabilization: Role of neovascularization and intraplaque hemorrhage.

PubMed

Guo, Muyi; Cai, Yan; Yao, Xinke; Li, Zhiyong

2018-08-07

Observational studies have identified angiogenesis from the adventitial vasa vasorum and intraplaque hemorrhage (IPH) as critical factors in atherosclerotic plaque progression and destabilization. Here we propose a mathematical model incorporating intraplaque neovascularization and hemodynamic calculation with plaque destabilization for the quantitative evaluation of the role of neoangiogenesis and IPH in the vulnerable atherosclerotic plaque formation. An angiogenic microvasculature is generated by two-dimensional nine-point discretization of endothelial cell proliferation and migration from the vasa vasorum. Three key cells (endothelial cells, smooth muscle cells and macrophages) and three key chemicals (vascular endothelial growth factors, extracellular matrix and matrix metalloproteinase) are involved in the plaque progression model, and described by the reaction-diffusion partial differential equations. The hemodynamic calculation of the microcirculation on the generated microvessel network is carried out by coupling the intravascular, interstitial and transvascular flow. The plasma concentration in the interstitial domain is defined as the description of IPH area according to the diffusion and convection with the interstitial fluid flow, as well as the extravascular movement across the leaky vessel wall. The simulation results demonstrate a series of pathophysiological phenomena during the vulnerable progression of an atherosclerotic plaque, including the expanding necrotic core, the exacerbated inflammation, the high microvessel density (MVD) region at the shoulder areas, the transvascular flow through the capillary wall and the IPH. The important role of IPH in the plaque destabilization is evidenced by simulations with varied model parameters. It is found that the IPH can significantly speed up the plaque vulnerability by increasing necrotic core and thinning fibrous cap. In addition, the decreased MVD and vessel permeability may slow down the process of plaque destabilization by reducing the IPH dramatically. We envision that the present model and its future advances can serve as a valuable theoretical platform for studying the dynamic changes in the microenvironment during the plaque destabilization. Copyright © 2018 Elsevier Ltd. All rights reserved.

Fine Structure of the Male Reproductive System and Reproductive Behavior of Lutzomyia longipalpis Sandflies (Diptera: Psychodidae: Phlebotominae)

PubMed Central

Peixoto, Alexandre A.; Vigoder, Felipe M.; Bruno, Rafaela V.; Soares, Maurilio J.

2013-01-01

Background The male reproductive system of insects can have several tissues responsible for the secretion of seminal fluid proteins (SFPs), such as testes, accessory glands, seminal vesicles, ejaculatory duct and ejaculatory bulb. The SFPs are transferred during mating and can induce several physiological and behavioral changes in females, such as increase in oviposition and decrease in sexual receptivity after copulation. The phlebotomine Lutzomyia longipalpis is the main vector of visceral leishmaniasis. Despite its medical importance, little is known about its reproductive biology. Here we present morphological aspects of the male L. longipalpis reproductive system by light, scanning and transmission electron microscopy, and compare the mating frequency of both virgin and previously mated females. Results The male L. longipalpis reproductive system is comprised by a pair of oval-shaped testes linked to a seminal vesicle by vasa deferentia. It follows an ejaculatory duct with an ejaculatory pump (a large bulb enveloped by muscles and associated to tracheas). The terminal endings of the vasa deferentia are inserted into the seminal vesicle by invaginations of the seminal vesicle wall, which is composed by a single layer of gland cells, with well-developed endoplasmic reticulum profiles and secretion granules. Our data suggest that the seminal vesicle acts both as a spermatozoa reservoir and as an accessory gland. Mating experiments support this hypothesis, revealing a decrease in mating frequency after copulation that indicates the effect of putative SFPs. Conclusion Ultrastructural features of the L. longipalpis male seminal vesicle indicated its possible role as an accessory gland. Behavioral observations revealed a reduction in mating frequency of copulated females. Together with transcriptome analyses from male sandfly reproductive organs identifying ESTs encoding orthologs of SFPs, these data indicate the presence of putative L. longipalpis SFPs reducing sexual mating frequency of copulated females. PMID:24058637

[Aortic inflammatory lesions in Behçet's disease].

PubMed

Desbois, A-C; Wechsler, B; Cacoub, P; Saadoun, D

2016-04-01

The arterial lesions affect about 10% of patients with Behçet's disease (BD). Aortic inflammatory involvement includes predominantly aortic aneurysmal lesions affecting most often the abdominal aorta. They account for the severity of the disease and are a leading cause of death when they hit the aorta or pulmonary arteries. Within the arterial lesions of BD, aortic involvement is, with femoral lesions, the most common site involved (18-28% of patients with vascular disease). Unlike other large vessels vasculitis (i.e. giant cell arteritis and Takayasu's arteritis) diffuse aortitis is observed in less than 5% of patients with BD. Aortic lesions of BD may be asymptomatic (systematic imaging or occasionally associated with other vascular event) or be revealed by the occurrence of abdominal, thoracic or lumbar pain, or an aortic valve insufficiency. Fever is frequently associated. Increase in acute phase reactants is common in these patients. Histological analysis may show infiltration by lymphocytes, neutrophils and plasma cells in the media and adventitia and a proliferation of the vasa vasorum in the media as well as a fibroblastic proliferation. In the later phase, a fibrous thickening of the media and adventitia is observed as well as a proliferation and thickening of the vasa vasorum. The therapeutic management should always include a medical treatment for the control of inflammation (corticosteroids, immunosuppressive drugs and/or biotherapy) and often an endovascular or surgical treatment if the aneurysm is threatening. The choice between endovascular or surgical treatment is considered case by case, depending on the experience of the team, anatomical conditions and of the clinical presentation. In this review, we provide a detailed and updated review of the literature to describe the aortic inflammatory damage associated with Behçet's disease. Copyright © 2015 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.

The Analgesic Effects of Morphine and Tramadol Added to Intra-articular Levobupivacaine-Tenoxicam Combination for Arthroscopic Knee Surgery on Postoperative Pain; a Randomized Clinical Trial

PubMed Central

Oral, Ebru Gelici; Hanci, Ayse; Ulufer Sivrikaya, Gulcihan; Dobrucali, Hale; Turkoglu Kilinc, Leyla

2015-01-01

Background: Arthroscopic knee surgery is commonly performed as an outpatient procedure and is often associated with postoperative pain. Objectives: We aimed to compare the effects of intra-articular levobupivacaine-tenoxicam-tramadol and levobupivacaine-tenoxicam-morphine combinations on postoperative pain in patients undergoing elective arthroscopic knee surgery. Materials and Methods: A total of 90 ASA I-II patients undergoing elective arthroscopic meniscectomy under general anesthesia were enrolled. The participants were randomly allocated to three groups to receive the following intra-articular medications after completion of the surgery and before deflation of the tourniquet: Group S, 20 mL of saline; Group T, 35 mg of levobupivacaine, 20 mg of tenoxicam, and 100 mg of tramadol in 20 mL saline; and Group M, 35 mg of levobupivacaine, 20 mg of tenoxicam, and 4 mg of morphine in 20 mL saline. Visual analogue scale values at rest (VASr) and at active flexion of knee (VASa) at postoperation hours 1, 2, 4, 8, 12, and 24, duration of analgesia, total analgesic consumption, and number of rescue analgesia at 24 hours were evaluated. Results: VASr and VASa were significantly higher in group S in comparison to other groups (P < 0.05). Duration of analgesia was significantly longer in Group T and Group M than in Group S (P < 0.05). The difference between group T and group M was also significant (P < 0.05). Number of rescue analgesia and total analgesic consumption at postoperative hour 24 was significantly fewer in group M compared with other groups (P < 0.05). Conclusions: Intra-articular levobupivacaine-tenoxicam-morphine combination provides effective pain relief, longer analgesic duration, and less analgesic requirement when compared with intra-articular levobupivacaine-tenoxicam-tramadol combination and saline after knee arthroscopic surgery. PMID:26161321

Hydrogen ion secretion by the collecting duct as a determinant of the urine to blood PCO2 gradient in alkaline urine

DOE Office of Scientific and Technical Information (OSTI.GOV)

DuBose, T.D. Jr.

1982-01-01

Several theories have been advanced to explain the elevation in urinary PCO/sub 2/ during bicarbonate loading and include: (a) H+ secretion, (b) countercurrent system for CO/sub 2/, (c) the ampholyte properties of bicarbonate, and (d) mixing of urine of disparate bicarbonate and butter concentrations. In this study microelectrodes were used to measure in situ and equilibrium pH (pHis and pHeq) and PCO/sub 2/ in control and bicarbonate loaded rats before and after infusion of carbonic anhydrase. The disequilibrium pH method (pHdq . pHis - pHeq) was used to demonstrate H+ secretion. Control rats excreting an acid urine (pH . 6.04more » +/- 0.06) failed to display a significant disequilibrium pH at the base (BCD), or tip (TCD) of the papillary collecting duct. Urine pH (7.54 +/- 0.12), and urine to blood (U-B) PCO/sub 2/ increased significantly during NaHCO/sub 3/ loading while PCO/sub 2/ at the BCD and TCD also increased (95 +/- 4 and 122 +/- 4). Furthermore, an acid disequilibrium pH was present at both the BCD and TCD (-0.42 +/- 0.04 and -0.36 +/- 0.03) and was obliterated by carbonic anhydrase. Comparison of the PCO/sub 2/ in the BCD or TCD with the adjacent vasa recta revealed similar values (r . 0.97). It is concluded that H+ secretion by the collecting duct into bicarbonate containing fluid with delayed dehydration of H/sub 2/CO/sub 3/, is the most likely determinant of the U-B PCO/sub 2/ in alkaline urine. Similar values for PCO/sub 2/ in the collecting duct and the adjacent vasa recta suggests trapping of CO/sub 2/ in the medullary countercurrent system. The rise in PCO/sub 2/ occurs both along the collecting duct and after exit from the papilla.« less

Bilateral Patellar Tendon Rupture

DTIC Science & Technology

2009-07-01

Bilateral patellar tendon rupture Military Medicine Radiology Corner, Volume 173, July, 2009...Radiology Corner Bilateral patellar tendon rupture (#37) Guarantor: 2dLt Ramon A. Riojas, USAF, MSC1 Contributors: 2dLt Ramon A. Riojas...with the abbreviated answer in the July 2009 issue. 1 The authors present a case of bilateral patellar tendon rupture in an active duty male exiting

Non-operative management in a case of spontaneous splenic rupture in infectious mononucleosis.

PubMed

Paar, W D; Look, M P; Robertz Vaupel, G M; Kreft, B; Hirner, A; Sauerbruch, T

1995-01-01

Spontaneous splenic rupture as a complication of infectious mononucleosis was diagnosed in a 19-year-old woman. Sonographic and MRI investigations revealed subcapsular hematoma of the spleen without overt rupture. The patient was managed conservatively. Somatostatin treatment was initiated in order to reduce splanchnic blood flow. Further clinical course of the patient was favourable. Seven days after the diagnosis of splenic rupture the patient was discharged from hospital. Non-operative management should be considered in patients with subcapsular splenic rupture to avoid complications of splenectomy (e.g. post-splenectomy sepsis).

Neck curve polynomials in neck rupture model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kurniadi, Rizal; Perkasa, Yudha S.; Waris, Abdul

2012-06-06

The Neck Rupture Model is a model that explains the scission process which has smallest radius in liquid drop at certain position. Old fashion of rupture position is determined randomly so that has been called as Random Neck Rupture Model (RNRM). The neck curve polynomials have been employed in the Neck Rupture Model for calculation the fission yield of neutron induced fission reaction of {sup 280}X{sub 90} with changing of order of polynomials as well as temperature. The neck curve polynomials approximation shows the important effects in shaping of fission yield curve.

Triceps Ruptures After Fluoroquinolone Antibiotics: A Report of 2 Cases.

PubMed

Shybut, Theodore B; Puckett, Ernest R

Rupture of the triceps brachii tendon is exceedingly rare, and surgical repair is generally indicated. Fluoroquinolone antibiotics have been implicated in tendon pathology, including tendon ruptures. Triceps rupture has not been previously reported in the setting of fluoroquinolone antibiotic therapy. We present 2 cases of triceps tendon rupture after treatment with fluoroquinolones. In both cases, triceps repair was performed with good outcomes. These cases highlight a risk of fluoroquinolone-induced tendinopathy to athletes. The sports medicine team should be aware of this risk and consider it when choosing antibiotics to treat athletes.

[Spontaneous splenic rupture as a complication of symptom-free infections mononucleosis].

PubMed

Szokó, Márta; Matolcsy, András; Kovács, Gábor; Simon, Gábor

2007-07-22

Splenic rupture is a rare complication of infectious mononucleosis. Although it occurs only in 0.1%-0.5% of cases, splenic rupture remains the most common fatal complication of the disease. Mononucleosis related spontaneous rupture of the spleen without any other characteristic symptoms of the disease is extremely unusual, and threatens with fatal outcome due to its rare and unexpected occurrence. The authors report the case of a 16-year-old boy who needed splenectomy following a spontaneous rupture of the spleen. Serological tests proved an acute Epstein-Barr virus infection in the background but without any signs or symptoms of infectious mononucleosis. The diagnosis and treatment of this infection related to spleen ruptures are also discussed.

Mechanism for Si–Si Bond Rupture in Single Molecule Junctions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Haixing; Kim, Nathaniel T.; Su, Timothy A.

The stability of chemical bonds can be studied experimentally by rupturing single molecule junctions under applied voltage. Here, we compare voltage-induced bond rupture in two Si–Si backbones: one has no alternate conductive pathway whereas the other contains an additional naphthyl pathway in parallel to the Si–Si bond. We show that in contrast to the first system, the second can conduct through the naphthyl group when the Si–Si bond is ruptured using an applied voltage. We investigate this voltage induced Si–Si bond rupture by ab initio density functional theory calculations and molecular dynamics simulations that ultimately demonstrate that the excitation ofmore » molecular vibrational modes by tunneling electrons leads to homolytic Si–Si bond rupture.« less

Mechanism for Si-Si Bond Rupture in Single Molecule Junctions.

PubMed

Li, Haixing; Kim, Nathaniel T; Su, Timothy A; Steigerwald, Michael L; Nuckolls, Colin; Darancet, Pierre; Leighton, James L; Venkataraman, Latha

2016-12-14

The stability of chemical bonds can be studied experimentally by rupturing single molecule junctions under applied voltage. Here, we compare voltage-induced bond rupture in two Si-Si backbones: one has no alternate conductive pathway whereas the other contains an additional naphthyl pathway in parallel to the Si-Si bond. We show that in contrast to the first system, the second can conduct through the naphthyl group when the Si-Si bond is ruptured using an applied voltage. We investigate this voltage induced Si-Si bond rupture by ab initio density functional theory calculations and molecular dynamics simulations that ultimately demonstrate that the excitation of molecular vibrational modes by tunneling electrons leads to homolytic Si-Si bond rupture.

[Birth and pregnancy outcomes of drug addicted women].

PubMed

Tzur, Tamar; Aslanov, Lili; Sheiner, Eyal; Levy, Amalia

2012-03-01

Illegal drug abuse causes significant health problems with consequences to the mother and the neonate, and an economic burden to the health system. The present study aimed to investigate pregnancy and perinatal outcome in women using illegal drugs prior to and during pregnancy. A retrospective cohort study comparing pregnancy and neonatal outcomes of drug addicted women to the outcomes of other Jewish women. The study population includes all women who gave birth between the years 1989-2008 at the Soroka University Medical Center. From a total of 106,000 deliveries, 119 women were known to be drug addicted. No significant differences were found between the groups regarding maternal age and origin, but more women in the addicted group smoked, and tacked prenatal care. More women in the addicted group had obstetrics complications such as: recurrent abortions, placenta previa, pLacental abruption and preterm labor. Illegal drug abuse was significantly associated with adverse perinatal outcomes such as low birth weight, congenital anomalies, peripartum death and prolonged hospitalizations. Illegal drug abuse is an independent risk factor for adverse obstetric and perinatal outcomes. This study investigated a significant problem that may be underestimated in our population. The higher incidence of pLacental abruption, placenta previa, preterm tabor and low birth weight could be a sign for placentaL insult. Illegal drug abuse is an independent risk factor for adverse perinatal outcomes and causes an economic burden. Further national studies are needed to characterize the problem, and to develop appropriate intervention programs.

The efficacy of pre-delivery prophylactic trans-catheter arterial balloon occlusion of bilateral internal iliac artery in patients with suspected placental adhesion.

PubMed

Cho, Yoon Jin; Oh, Yong Taek; Kim, Suk Young; Kim, Ju Young; Jung, Sun Young; Chon, Seung Joo; Kim, Jeong Ho; Byun, Sung Su

2017-01-01

Prophylactic trans-catheter arterial balloon occlusion (PTABO) before cesarean section of placenta previa totalis has been introduced to prevent massive hemorrhage. The purpose of this study is to evaluate the clinical usefulness of PTABO in cases of suspected placental adhesion and to examine antepartal risk factors and perinatal outcomes in women with placental adhesion. Between January 2012 and December 2015, 77 patients who had undergone ultrasonography for evaluation of placenta previa were enrolled in this study. Seventeen of these patients with suspected placental adhesion by ultrasonography and Pelvic MRI underwent PTABO before cesarean section and another 59 patients underwent cesarean section without PTABO. Antepartal risk factors and peripartum maternal and neonatal outcomes were compared between patients with PTABO and those without PTABO. More advanced maternal age, longer in gestational weeks at delivery, and more common previous cesarean section history were observed in the PTABO group. Placenta adhesion, abnormal Doppler findings, and frequency of transfusion were more common in the PTABO group. However there was no significant difference in estimated blood loss, hospital days, and neonatal outcome. It had occurred 3 cases of hysterectomy and 1 case of uterine artery embolization after cesarean section in the PTABO group. Close surveillance of antepartum risk factors for placental adhesion using ultrasonography and pelvic magnetic resonance imaging is important to prevention of massive hemorrhage during cesarean section. PTABO before cesarean section might result in reduced blood loss and requirement for transfusion during the operation.

Accuracy of Home-Based Ultrasonographic Diagnosis of Obstetric Risk Factors by Primary-Level Health Workers in Rural Nepal

PubMed Central

Kozuki, Naoko; Mullany, Luke C.; Khatry, Subarna K.; Ghimire, Ram K.; Paudel, Sharma; Blakemore, Karin; Bird, Christine; Tielsch, James M.; LeClerq, Steven C.; Katz, Joanne

2016-01-01

Objective To assess the feasibility of task shifting by estimating the accuracy at which primary-level health care workers can perform community-based third trimester ultrasound diagnosis for selected obstetric risk factors in rural Nepal. Methods Three auxiliary nurse midwives received two one-week ultrasound trainings at Tribhuvan University Teaching Hospital in Kathmandu. In our study site in rural Nepal, women who were ≥32 weeks in gestational age were enrolled and received ultrasound examinations from the auxiliary nurse midwives during home visits. Each auxiliary nurse midwife screened for non-cephalic presentation, multiple gestation, and placenta previa. All de-identified images were stored and uploaded onto an online server, where certified sonologists and sonographers reviewed the images and made their own diagnoses for the three conditions. Accuracy of auxiliary nurse midwife diagnoses was then calculated. Results We enrolled 804 women in the study. Each auxiliary nurse midwife’s kappa statistic for diagnosis of non-cephalic presentation was above 0.90 compared with the sonogram reviewers. Sensitivity, specificity, positive and negative predictive values were between 90–100% for all auxiliary nurse midwives For multiple gestation, the auxiliary nurse midwives were in perfect agreement with both the sonogram reviewers and maternal postpartum self-report. Two placenta previa cases were detected, and the sonogram reviewers agreed with both. Conclusion With limited training, primary-level health care workers in rural Nepal can accurately diagnose selected third trimester obstetric risk factors using ultrasonography. PMID:27500343

Bedside risk estimation of morbidly adherent placenta using simple calculator.

PubMed

Maymon, R; Melcer, Y; Pekar-Zlotin, M; Shaked, O; Cuckle, H; Tovbin, J

2018-03-01

To construct a calculator for 'bedside' estimation of morbidly adherent placenta (MAP) risk based on ultrasound (US) findings. This retrospective study included all pregnant women with at least one previous cesarean delivery attending in our US unit between December 2013 and January 2017. The examination was based on a scoring system which determines the probability for MAP. The study population included 471 pregnant women, and 41 of whom (8.7%) were diagnosed with MAP. Based on ROC curve, the most effective US criteria for detection of MAP were the presence of the placental lacunae, obliteration of the utero-placental demarcation, and placenta previa. On the multivariate logistic regression analysis, US findings of placental lacunae (OR = 3.5; 95% CI, 1.2-9.5; P = 0.01), obliteration of the utero-placental demarcation (OR = 12.4; 95% CI, 3.7-41.6; P < 0.0001), and placenta previa (OR = 10.5; 95% CI, 3.5-31.3; P < 0.0001) were associated with MAP. By combining these three parameters, the receiver operating characteristic curve was calculated, yielding an area under the curve of 0.93 (95% CI, 0.87-0.97). Accordingly, we have constructed a simple calculator for 'bedside' estimation of MAP risk. The calculator is mounted on the hospital's internet website ( http://www.assafh.org/Pages/PPCalc/index.html ). The risk estimation of MAP varies between 1.5 and 87%. The present calculator enables a simple 'bedside' MAP estimation, facilitating accurate and adequate antenatal risk assessment.

Endometriosis and obstetrics complications: a systematic review and meta-analysis.

PubMed

Zullo, Fabrizio; Spagnolo, Emanuela; Saccone, Gabriele; Acunzo, Miriam; Xodo, Serena; Ceccaroni, Marcello; Berghella, Vincenzo

2017-10-01

To evaluate the effect of endometriosis on pregnancy outcomes. Systematic review and meta-analysis. Not applicable. Women with or without endometriosis. Electronic databases searched from their inception until February 2017 with no limit for language and with all cohort studies reporting the incidence of obstetric complications in women with a diagnosis of endometriosis compared with a control group (women without a diagnosis of endometriosis) included. Primary outcome of incidence of preterm birth at <37 weeks with meta-analysis performed using the random effects model of DerSimonian and Laird to produce an odds ratio (OR) with 95% confidence interval (CI). Twenty-four studies were analyzed comprising 1,924,114 women. In most of them, the diagnosis of endometriosis was made histologically after surgery. Women with endometriosis had a statistically significantly higher risk of preterm birth (OR 1.63; 95% CI, 1.32-2.01), miscarriage (OR 1.75; 95% CI, 1.29-2.37), placenta previa (OR 3.03; 95% CI, 1.50-6.13), small for gestational age (OR 1.27; 95% CI, 1.03-1.57), and cesarean delivery (OR 1.57; 95% CI, 1.39-1.78) compared with the healthy controls. No differences were found in the incidence of gestational hypertension and preeclampsia. Women with endometriosis have a statistically significantly higher risk of preterm birth, miscarriage, placenta previa, small for gestational age infants, and cesarean delivery. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Spontaneous tendon rupture in systemic lupus erythematosus: association with Jaccoud's arthropathy.

PubMed

Alves, E M; Macieira, J C; Borba, E; Chiuchetta, F A; Santiago, M B

2010-03-01

Tendon rupture has rarely been described in patients with systemic lupus erythematosus. From observation of three cases of Jaccoud's arthropathy with tendon rupture, and considering that this arthropathy is more related to an inflammatory process of the tendon sheath than to synovitis per se, the intention of this study was to review the cases of tendon rupture in patients with systemic lupus erythematosus, in the hope of determining the frequency of Jaccoud's arthropathy associated with this complication. Systematic review using MEDLINE, Scielo and LILACS databases (1966 to 2009) and the following keywords: systemic lupus erythematosus, tendon rupture, Jaccoud's arthropathy. Secondary references were additionally obtained. Additionally, three Brazilian systemic lupus erythematosus patients who developed tendon rupture are described. Only 40 articles obtained fulfilled the previously established criteria. They were all case reports; the number of cases reported was 52 which, together with the three cases presented herein add up to 55 cases. Forty-six patients were women aged between 19 and 71 years, with a mean age of 40.1 +/- 12.4 years, and the average duration of the disease was 10 years. The most frequently observed rupture sites were the patellar and Achilles' tendons. While almost all patients described were on various doses of corticosteroids, 16 patients concomitantly had Jaccoud's arthropathy (29%). In conclusion, the association between Jaccoud's arthropathy and tendon rupture in systemic lupus erythematosus has been underestimated. As almost one-third of the systemic lupus erythematosus patients with tendon rupture also have Jaccoud's arthropathy, this arthropathy may be recognized as risk marker for tendon rupture.

Rupture complexity and the supershear transition on rough faults

NASA Astrophysics Data System (ADS)

Bruhat, Lucile; Fang, Zijun; Dunham, Eric M.

2016-01-01

Field investigations suggest that supershear earthquakes occur on geometrically simple, smooth fault segments. In contrast, dynamic rupture simulations show how heterogeneity of stress, strength, and fault geometry can trigger supershear transitions, as well as other complex rupture styles. Here we examine the Fang and Dunham (2013) ensemble of 2-D plane strain dynamic ruptures on fractally rough faults subject to strongly rate weakening friction laws to document the effect of fault roughness and prestress on rupture behavior. Roughness gives rise to extremely diverse rupture styles, such as rupture arrests, secondary slip pulses that rerupture previously slipped fault sections, and supershear transitions. Even when the prestress is below the Burridge-Andrews threshold for supershear on planar faults with uniform stress and strength conditions, supershear transitions are observed. A statistical analysis of the rupture velocity distribution reveals that supershear transients become increasingly likely at higher stress levels and on rougher faults. We examine individual ruptures and identify recurrent patterns for the supershear transition. While some transitions occur on fault segments that are favorably oriented in the background stress field, other transitions happen at the initiation of or after propagation through an unfavorable bend. We conclude that supershear transients are indeed favored by geometric complexity. In contrast, sustained supershear propagation is most common on segments that are locally smoother than average. Because rupture style is so sensitive to both background stress and small-scale details of the fault geometry, it seems unlikely that field maps of fault traces will provide reliable deterministic predictions of supershear propagation on specific fault segments.

Permeability Variations Associated With Fault Reactivation in a Claystone Formation Investigated by Field Experiments and Numerical Simulations

NASA Astrophysics Data System (ADS)

Jeanne, Pierre; Guglielmi, Yves; Rutqvist, Jonny; Nussbaum, Christophe; Birkholzer, Jens

2018-02-01

We studied the relation between rupture and changes in permeability within a fault zone intersecting the Opalinus Clay formation at 300 m depth in the Mont Terri Underground Research Laboratory (Switzerland). A series of water injection experiments were performed in a borehole straddle interval set within the damage zone of the main fault. A three-component displacement sensor allowed an estimation of the displacement of a minor fault plane reactivated during a succession of step rate pressure tests. The experiment reveals that the fault hydromechanical (HM) behavior is different from one test to the other with varying pressure levels needed to trigger rupture and different slip behavior under similar pressure conditions. Numerical simulations were performed to better understand the reason for such different behavior and to investigate the relation between rupture nucleation, permeability change, pressure diffusion, and rupture propagation. Our main findings are as follows: (i) a rate frictional law and a rate-and-state permeability law can reproduce the first test, but it appears that the rate constitutive parameters must be pressure dependent to reproduce the complex HM behavior observed during the successive injection tests; (ii) almost similar ruptures can create or destroy the fluid diffusion pathways; (iii) a too high or too low diffusivity created by the main rupture prevents secondary rupture events from occurring whereas "intermediate" diffusivity favors the nucleation of a secondary rupture associated with the fluid diffusion. However, because rupture may in certain cases destroy permeability, this succession of ruptures may not necessarily create a continuous hydraulic pathway.

Multimodality Imaging-based Evaluation of Single-Lumen Silicone Breast Implants for Rupture.

PubMed

Seiler, Stephen J; Sharma, Pooja B; Hayes, Jody C; Ganti, Ramapriya; Mootz, Ann R; Eads, Emily D; Teotia, Sumeet S; Evans, W Phil

2017-01-01

Breast implants are frequently encountered on breast imaging studies, and it is essential for any radiologist interpreting these studies to be able to correctly assess implant integrity. Ruptures of silicone gel-filled implants often occur without becoming clinically obvious and are incidentally detected at imaging. Early diagnosis of implant rupture is important because surgical removal of extracapsular silicone in the breast parenchyma and lymphatics is difficult. Conversely, misdiagnosis of rupture may prompt a patient to undergo unnecessary additional surgery to remove the implant. Mammography is the most common breast imaging examination performed and can readily depict extracapsular free silicone, although it is insensitive for detection of intracapsular implant rupture. Ultrasonography (US) can be used to assess the internal structure of the implant and may provide an economical method for initial implant assessment. Common US signs of intracapsular rupture include the "keyhole" or "noose" sign, subcapsular line sign, and "stepladder" sign; extracapsular silicone has a distinctive "snowstorm" or echogenic noise appearance. Magnetic resonance (MR) imaging is the most accurate and reliable means for assessment of implant rupture and is highly sensitive for detection of both intracapsular and extracapsular rupture. MR imaging findings of intracapsular rupture include the keyhole or noose sign, subcapsular line sign, and "linguine" sign, and silicone-selective MR imaging sequences are highly sensitive to small amounts of extracapsular silicone. © RSNA, 2017.

Heart rupture predictors in Spanish myocardial infarction patients: evaluation using propensity score analysis.

PubMed

Ruiz-Bailén, Manuel; Expósito-Ruiz, Manuela; Castillo-Rivera, Ana-María; Rucabado-Aguilar, Luis; Ruiz-García, María Isabel; Ramos-Cuadra, José-Angel; Ruiz-Valverde, Andrés; Gómez-Jiménez, Javier; Benitez-Parejo, José-Luis; Cuñat de la Hoz, José; Abat, Francisco Felices; Valenzuela, Jesús Pérez

2010-05-01

The aim was to evaluate factors associated with the development of heart rupture in a Spanish registry of acute myocardial infarction (AMI) patients. This was a retrospective study of cohorts, including all patients diagnosed with AMI included in the ARIAM Spanish multicenter registry. The study period was from June 1996 to December 2005. The follow-up period was limited to the time of stay in intensive care or coronary care units. Multivariate logistic regression was used to study the factors associated with the development of heart rupture. A propensity score analysis was also performed to determine the involvement of beta blockers, ACE inhibitors, and fibrinolytics in the development of heart rupture. 16,815 AMI patients were included. Heart rupture occurred in 477 (2.8%). Heart rupture was associated with female gender, older age, the absence of previous infarct, and the administration of thrombolysis, while ACE inhibitors and beta blockers acted as protective variables. The propensity score analysis showed that fibrinolysis was a variable associated with heart rupture except in the younger subgroup and in the subgroup with less delay in administration. It was also found that beta blockers and ACE inhibitors are variables providing protection against heart rupture. Heart rupture is associated with older age, female gender, absence of previous infarct, and the administration of thrombolysis, while ACE inhibitors and beta blockers seem to prevent this complication.

Unruptured cerebral aneurysms do not shrink when they rupture: multicenter collaborative aneurysm study group.

PubMed

Rahman, Maryam; Ogilvy, Christopher S; Zipfel, Gregory J; Derdeyn, Colin P; Siddiqui, Adnan H; Bulsara, Ketan R; Kim, Louis J; Riina, Howard A; Mocco, J; Hoh, Brian L

2011-01-01

The International Study of Intracranial Aneurysms found that for patients with no previous history of subarachnoid hemorrhage, small (< 7 mm) anterior circulation and posterior circulation aneurysms had a 0% and 2.5% risk of subarachnoid hemorrhage over 5 years, respectively. To determine whether cerebral aneurysms shrink with rupture. The clinical databases of 7 sites were screened for patients with imaging of cerebral aneurysms before and after rupture. Inclusion criteria included documented subarachnoid hemorrhage by imaging or lumbar puncture and intracranial imaging before and after cerebral aneurysm rupture. The patients were evaluated for aneurysm maximal height, maximal width, neck diameter, and other measurement parameters. Only a change of ≥ 2 mm was considered a true change. Data on 13 patients who met inclusion criteria were collected. The median age was 60, and 11 of the 13 patients (84.6%) were female. Only 5 patients had posterior circulation aneurysms. None of the aneurysms had a significant decrease in size. One aneurysm decreased by 1.8 mm in maximum size after rupture (7.7%). Six aneurysms had an increase in maximum size of at least 2 mm after rupture (46.2%) with a mean increase of 3.5 mm (± 0.5 mm). Unruptured aneurysms do not shrink when they rupture. The large percentage of ruptured small aneurysms in previous studies were likely small before they ruptured.

Steady-state propagation speed of rupture fronts along one-dimensional frictional interfaces.

PubMed

Amundsen, David Skålid; Trømborg, Jørgen Kjoshagen; Thøgersen, Kjetil; Katzav, Eytan; Malthe-Sørenssen, Anders; Scheibert, Julien

2015-09-01

The rupture of dry frictional interfaces occurs through the propagation of fronts breaking the contacts at the interface. Recent experiments have shown that the velocities of these rupture fronts range from quasistatic velocities proportional to the external loading rate to velocities larger than the shear wave speed. The way system parameters influence front speed is still poorly understood. Here we study steady-state rupture propagation in a one-dimensional (1D) spring-block model of an extended frictional interface for various friction laws. With the classical Amontons-Coulomb friction law, we derive a closed-form expression for the steady-state rupture velocity as a function of the interfacial shear stress just prior to rupture. We then consider an additional shear stiffness of the interface and show that the softer the interface, the slower the rupture fronts. We provide an approximate closed form expression for this effect. We finally show that adding a bulk viscosity on the relative motion of blocks accelerates steady-state rupture fronts and we give an approximate expression for this effect. We demonstrate that the 1D results are qualitatively valid in 2D. Our results provide insights into the qualitative role of various key parameters of a frictional interface on its rupture dynamics. They will be useful to better understand the many systems in which spring-block models have proved adequate, from friction to granular matter and earthquake dynamics.

[Zwipp Percutaneous Suture of the Achilles Tendon with the Dresden Instruments].

PubMed

Chmielnicki, M; Prokop, A

2016-06-01

Rupture of the Achilles tendon is the most common rupture of a tendon in man. Acute rupture of the Achilles tendon may be treated in a variety of manners, including conservative treatment, open suture and percutaneous suture. Surgical treatment of active patients is recommended, as the risk of re-rupture is greater after non-surgical treatment. The aim of surgery is adequate treatment of Achilles tendon rupture with a low rate of complications, high comfort for patients and fast social and occupational rehabilitation. The indication for surgical treatment of Achilles tendon rupture predominantly includes ruptures in active patients, with the goal of optimal functional rehabilitation. Furthermore, the percutaneous technique protects soft tissue, with a lower rate of wound healing disorders and infection than with open surgical treatment. In our clinic we perform the percutaneous suturing technique with the Dresden instruments. The surgical technique and functional aftercare are shown in a video clip. Between 2007 and 2013, we treated 212 patients with acute Achilles tendon rupture by surgery with the Dresden instruments. There were 7 re-ruptures (3.3 %) and one case of infection within one year of surgery. Percutaneous Achilles tendon suture technique with the Dresden instruments is a safe operation that protects soft tissue. Patient satisfaction is high and the rate of complications is low. This allows rapid social and occupational rehabilitation. Georg Thieme Verlag KG Stuttgart · New York.

Radionuclide diagnosis of splenic rupture in infectious mononucleosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vezina, W.C.; Nicholson, R.L.; Cohen, P.

1984-06-01

Spontaneous splenic rupture is a rare but serious complication of infectious mononucleosis. Although radionuclide spleen imaging is a well accepted method for diagnosis of traumatic rupture, interpretation can be difficult in the setting of mononucleosis, as tears may be ill-defined and diagnosis hampered by inhomogeneous splenic uptake. Four proven cases of spontaneous rupture are presented, three of which illustrate these diagnostic problems.

Using Multi-scale Dynamic Rupture Models to Improve Ground Motion Estimates: ALCF-2 Early Science Program Technical Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ely, Geoffrey P.

2013-10-31

This project uses dynamic rupture simulations to investigate high-frequency seismic energy generation. The relevant phenomena (frictional breakdown, shear heating, effective normal-stress fluctuations, material damage, etc.) controlling rupture are strongly interacting and span many orders of magnitude in spatial scale, requiring highresolution simulations that couple disparate physical processes (e.g., elastodynamics, thermal weakening, pore-fluid transport, and heat conduction). Compounding the computational challenge, we know that natural faults are not planar, but instead have roughness that can be approximated by power laws potentially leading to large, multiscale fluctuations in normal stress. The capacity to perform 3D rupture simulations that couple these processes willmore » provide guidance for constructing appropriate source models for high-frequency ground motion simulations. The improved rupture models from our multi-scale dynamic rupture simulations will be used to conduct physicsbased (3D waveform modeling-based) probabilistic seismic hazard analysis (PSHA) for California. These calculation will provide numerous important seismic hazard results, including a state-wide extended earthquake rupture forecast with rupture variations for all significant events, a synthetic seismogram catalog for thousands of scenario events and more than 5000 physics-based seismic hazard curves for California.« less

Comparative silicone breast implant evaluation using mammography, sonography, and magnetic resonance imaging: experience with 59 implants.

PubMed

Ahn, C Y; DeBruhl, N D; Gorczyca, D P; Shaw, W W; Bassett, L W

1994-10-01

With the current controversy regarding the safety of silicone implants, the detection and evaluation of implant rupture are causing concern for both plastic surgeons and patients. Our study obtained comparative value analysis of mammography, sonography, and magnetic resonance imaging (MRI) in the detection of silicone implant rupture. Twenty-nine symptomatic patients (total of 59 silicone implants) were entered into the study. Intraoperative findings revealed 21 ruptured implants (36 percent). During physical examination, a positive "squeeze test" was highly suggestive of implant rupture. Mammograms were obtained of 51 implants (sensitivity 11 percent, specificity 89 percent). Sonography was performed on 57 implants (sensitivity 70 percent, specificity 92 percent). MRI was performed on 55 implants (sensitivity 81 percent, specificity 92 percent). Sonographically, implant rupture is demonstrated by the "stepladder sign." Double-lumen implants may appear as false-positive results for rupture on sonography. On MRI, the "linguine sign" represents disrupted fragments of a ruptured implant. The most reliable imaging modality for implant rupture detection is MRI, followed by sonogram. Mammogram is the least reliable. Our study supports the clinical indication and diagnostic value of sonogram and MRI in the evaluation of symptomatic breast implant patients.

Fine structure of the landers fault zone: Segmentation and the rupture process

USGS Publications Warehouse

Li, Y.-G.; Vidale, J.E.; Aki, K.; Marone, C.J.; Lee, W.H.K.

1994-01-01

Observations and modeling of 3- to 6-hertz seismic shear waves trapped within the fault zone of the 1992 Landers earthquake series allow the fine structure and continuity of the zone to be evaluated. The fault, to a depth of at least 12 kilometers, is marked by a zone 100 to 200 meters wide where shear velocity is reduced by 30 to 50 percent. This zone forms a seismic waveguide that extends along the southern 30 kilometers of the Landers rupture surface and ends at the fault bend about 18 kilometers north of the main shock epicenter. Another fault plane waveguide, disconnected from the first, exists along the northern rupture surface. These observations, in conjunction with surface slip, detailed seismicity patterns, and the progression of rupture along the fault, suggest that several simple rupture planes were involved in the Landers earthquake and that the inferred rupture front hesitated or slowed at the location where the rupture jumped from one to the next plane. Reduction in rupture velocity can tentatively be attributed to fault plane complexity, and variations in moment release can be attributed to variations in available energy.

[Effects of posterior tibial slope on non-contact anterior cruciate ligament rupture and stability of anterior cruciate ligament rupture knee].

PubMed

Yue, De-bo; E, Sen; Wang, Bai-liang; Wang, Wei-guo; Guo, Wan-shou; Zhang, Qi-dong

2013-05-07

To retrospectively explore the correlation between anterior cruciate ligament (ACL)-ruptured knees, stability of ACL-rupture knee and posterior tibial slope (PTS). From January 2008 to October 2012, 150 knees with ACL rupture underwent arthroscopic surgery for ACL reconstruction. A control group was established for subjects undergoing arthroscopic surgery without ACL rupture during the same period. PTS was measured on a digitalized lateral radiograph. Lachman and mechanized pivot shift tests were performed for assessing the stability of knee. There was significant difference (P = 0.007) in PTS angle between the patients with ACL rupture (9.5 ± 2.2 degrees) and the control group (6.6 ± 1.8 degrees). Only among females, increased slope of tibial plateau had effect on the Lachman test. There was a higher positive rate of pivot shift test in patients of increased posterior slope in the ACL rupture group. Increased posterior tibial slope (>6.6) appears to contribute to non-contact ACL injuries in females. And the changes of tibial slope have no effect upon the Lachman test. However, large changes in tibial slope affect pivot shift.

Scram recoveries---C Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Constable, D.W.; Pierce, J.R.; Wood, S.A.

1962-04-26

The purpose of this report is to discuss the observations made on two equilibrium scram recovery startups (April 5 and April 16). Normally, the two startups would have little significance but unusual ruptures were experienced in the top near section of the reactor shortly after both startups, which indicates that some similarity could exist between the two. The ruptures were unusual in that the two tubes involved both had multiple ruptures. One tube contained two E{sup 2} ruptures and the other tube contained three overbore metal ruptures. The overbore tube also contained three incipient ruptures (uranium split under the can).more » The initial rise to power on both startups appeared to be normal with the flux peaking on the near side as expected. On the April 16 startup the maximum level reached was 1050 at which time a rupture in overbore tube 3062 caused on increase in pressure resulting in a high trip on the Panellit gauge. A level of 1600 was reached on the April 5 startup which was held for approximately 14 hours at which time the reactor was shut down due to rupture indications on row 29.« less

Ruptured thought: rupture as a critical attitude to nursing research.

PubMed

Beedholm, Kirsten; Lomborg, Kirsten; Frederiksen, Kirsten

2014-04-01

In this paper, we introduce the notion of ‘rupture’ from the French philosopher Michel Foucault, whose studies of discourse and governmentality have become prominent within nursing research during the last 25 years. We argue that a rupture perspective can be helpful for identifying and maintaining a critical potential within nursing research. The paper begins by introducing rupture as an inheritance from the French epistemological tradition. It then describes how rupture appears in Foucault's works, as both an overall philosophical approach and as an analytic tool in his historical studies. Two examples of analytical applications of rupture are elaborated. In the first example, rupture has inspired us to make an effort to seek alternatives to mainstream conceptions of the phenomenon under study. In the second example, inspired by Foucault's work on discontinuity, we construct a framework for historical epochs in nursing history. The paper concludes by discussing the potential of the notion of rupture as a response to the methodological concerns regarding the use of Foucault-inspired discourse analysis within nursing research. We agree with the critique of Cheek that the critical potential of discourse analysis is at risk of being undermined by research that tends to convert the approach into a fixed method.

Simultaneous uterine and urinary bladder rupture in an otherwise successful vaginal birth after cesarean delivery.

PubMed

Ho, Szu-Ying; Chang, Shuenn-Dhy; Liang, Ching-Chung

2010-12-01

Uterine rupture is the primary concern when a patient chooses a trial of labor after a cesarean section. Bladder rupture accompanied by uterine rupture should be taken into consideration if gross hematuria occurs. We report the case of a patient with uterine rupture during a trial of labor after cesarean delivery. She had a normal course of labor and no classic signs of uterine rupture. However, gross hematuria was noted after repair of the episiotomy. The patient began to complain of progressive abdominal pain, gross hematuria and oliguria. Cystoscopy revealed a direct communication between the bladder and the uterus. When opening the bladder peritoneum, rupture sites over the anterior uterus and posterior wall of the bladder were noted. Following primary repair of both wounds, a Foley catheter was left in place for 12 days. The patient had achieved a full recovery by the 2-year follow-up examination. Bladder injury and uterine rupture can occur at any time during labor. Gross hematuria immediately after delivery is the most common presentation. Cystoscopy is a good tool to identify the severity of bladder injury. Copyright © 2010 Elsevier. Published by Elsevier B.V. All rights reserved.

Map showing surface ruptures associated with the Mammoth Lakes, California, earthquakes of May 1980

USGS Publications Warehouse

Clark, M.M.; Yount, J.C.; Vaughn, P.R.; Zepeda, R.L.

1982-01-01

This map shows surface ruptures associated with the M 6 Mammoth Lakes earthquakes of May 25-27, 1980 (Sherburne, 1980). The ruptures were mapped during USGS field investigations May 28 to June 4 and July 14-19, 1980. The map also includes some of the ruptures recorded by California Division of Mines and Geology investigators May 26-31, June 26-27, and July 7-11, 1980 (Taylor and Bryant, 1980). Because most of the surface ruptures developed in either unconsolidated pumice, alluvium, or till (and many were on slopes of scarps created by earlier faulting), wind, rain and animals quickly erased many of the ruptures. In places, the minimum detectable slip was 3-10 mm. Thus the lines on the map do not record all of the ruptures that formed at the time of the earthquake. Many of the areas were we show gaps between lines on the map probably had cracks originally. 

Broadband simulations for Mw 7.8 southern san andreas earthquakes: Ground motion sensitivity to rupture speed

USGS Publications Warehouse

Graves, R.W.; Aagaard, Brad T.; Hudnut, K.W.; Star, L.M.; Stewart, J.P.; Jordan, T.H.

2008-01-01

Using the high-performance computing resources of the Southern California Earthquake Center, we simulate broadband (0-10 Hz) ground motions for three Mw 7.8 rupture scenarios of the southern San Andreas fault. The scenarios incorporate a kinematic rupture description with the average rupture speed along the large slip portions of the fault set at 0.96, 0.89, and 0.84 times the local shear wave velocity. Consistent with previous simulations, a southern hypocenter efficiently channels energy into the Los Angeles region along the string of basins south of the San Gabriel Mountains. However, we find the basin ground motion levels are quite sensitive to the prescribed rupture speed, with peak ground velocities at some sites varying by over a factor of two for variations in average rupture speed of about 15%. These results have important implications for estimating seismic hazards in Southern California and emphasize the need for improved understanding of earthquake rupture processes. Copyright 2008 by the American Geophysical Union.

Paleoearthquakes at Frazier Mountain, California delimit extent and frequency of past San Andreas Fault ruptures along 1857 trace

USGS Publications Warehouse

Scharer, Katherine M.; Weldon, Ray; Streig, Ashley; Fumal, Thomas

2014-01-01

Large earthquakes are infrequent along a single fault, and therefore historic, well-characterized earthquakes exert a strong influence on fault behavior models. This is true of the 1857 Fort Tejon earthquake (estimated M7.7–7.9) on the southern San Andreas Fault (SSAF), but an outstanding question is whether the 330 km long rupture was typical. New paleoseismic data for six to seven ground-rupturing earthquakes on the Big Bend of the SSAF restrict the pattern of possible ruptures on the 1857 stretch of the fault. In conjunction with existing sites, we show that over the last ~650 years, at least 75% of the surface ruptures are shorter than the 1857 earthquake, with estimated rupture lengths of 100 to <300 km. These results suggest that the 1857 rupture was unusual, perhaps leading to the long open interval, and that a return to pre-1857 behavior would increase the rate of M7.3–M7.7 earthquakes.

Surface rupture of the 2002 Denali fault, Alaska, earthquake and comparison with other strike-slip ruptures

USGS Publications Warehouse

Haeussler, Peter J.; Schwartz, D.P.; Dawson, T.E.; Stenner, Heidi D.; Lienkaemper, J.J.; Cinti, F.; Montone, Paola; Sherrod, B.; Craw, P.

2004-01-01

On 3 November 2002, an M7.9 earthquake produced 340 km of surface rupture on the Denali and two related faults in Alaska. The rupture proceeded from west to east and began with a 40-km-long break on a previously unknown thrust fault. Estimates of surface slip on this thrust are 3-6 m. Next came the principal surface break along ???218 km of the Denali fault. Right-lateral offsets averaged around 5 m and increased eastward to a maximum of nearly 9 m. The fault also ruptured beneath the trans-Alaska oil pipeline, which withstood almost 6 m of lateral offset. Finally, slip turned southeastward onto the Totschunda fault. Right-lateral offsets are up to 3 m, and the surface rupture is about 76 km long. This three-part rupture ranks among the longest strike-slip events of the past two centuries. The earthquake is typical when compared to other large earthquakes on major intracontinental strike-slip faults. ?? 2004, Earthquake Engineering Research Institute.

Hemoperitoneum from corpus luteum rupture in patients with aplastic anemia.

PubMed

Wang, Huaquan; Guo, Lifang; Shao, Zonghong

2015-01-01

Aplastic anemia is a rare hematopoietic stem-cell disorder that results in pancytopenia and hypocellular bone marrow. Women with aplastic anemia usually are at increased risk of corpus luteum rupture due to thrombocytopenia and infection. Here we report two cases had hemoperitoneum from corpus luteum rupture in patients with aplastic anemia in our center. Case 1 involved two episodes of hemoperitoneum resulting from rupture of the corpus luteum in a 23-year-old unmarried female with severe aplastic anemia. This patient was managed conservatively with platelet and packed red cell transfusion. Case 2 involved two episodes of hemoperitoneum resulting from rupture of the corpus luteum in a 33-year-old married patient with aplastic anemia. Emergency laparoscopy revealed massive hemoperitoneum. Bilateral salpingo-oophorectomy were performed successively with platelet and packed red cell transfusion. Hemoperitoneum resulting from a ruptured corpus luteum is a life-threatening condition in patients with aplastic anemia. Prompt and appropriate evaluation of corpus luteum rupture and emergent therapy are needed.

[Rupture of the Achilles tendon].

PubMed

Ulmar, B; Simon, S; Eschler, A; Mittlmeier, T

2014-10-01

The rupture of the Achilles tendon is the most frequent tendon rupture in humans and it is associated with increasing incidence. The main risk factor is intrinsic degeneration of the tendon. During the rupture the person feels a whiplash or dagger thrust-like pain, followed by restricted walking ability and decreased plantar flexion of the ankle. The positive Simmond/Thompson test and a palpable dent above the tendon rupture are pathognomical. Diagnostically, ultrasound of the tendon and lateral x-ray of the calcaneus (bony pull-out of the tendon insertion) are necessary. Regarding correct indication and treatment modalities, most established conservative and surgical therapies realize optimal functional results. Surgical treatment promises better primary stability and slightly earlier better functional results, but there is the potential for surgical complications. Conservative therapy is associated with higher rates of re-rupture and healing of the tendon under elongation. Therefore, therapy planning in Achilles tendon rupture should be determined based on each patient. We recommend surgical treatment in patients with higher sporting demands and in younger patients (< 50 years).

Rupture dimensions of the 1998 Antarctic Earthquake from low-frequency waves

NASA Astrophysics Data System (ADS)

McGuire, Jeffrey J.; Zhao, Li; Jordan, Thomas H.

2000-08-01

We inverted frequency dependent phase and amplitude measurements from 1st orbit Rayleigh waves at global stations for the 1st and 2nd degree polynomial moments of the stress-glut rate tensor. The higher moments of the slip-rate distribution determine the fault plane and approximate rupture dimensions. The results show strong rupture propagation to the west with an average velocity of the instantaneous centroid of 3.6±.1 km/s. The rupture had a characteristic length of 178±46 km in the east-west direction and a characteristic duration of 48±2 s. The results are consistent with unilateral rupture on the east-west fault plane of the focal mechanism and rule out significant rupture on the north-south nodal plane.

Intrapartum uterine rupture with coincidental uterine adenomyosis in an African wild dog (Lycaon pictus).

PubMed

Newell-Fugate, Annie; Lane, Emily

2009-12-01

A 7-yr-old African wild dog (Lycaon pictus) multiparous bitch experienced severe dystocia and death one day after the onset of parturition. Necropsy revealed three placental attachments in the right uterine horn and one in the left. A full-thickness rupture of the right horn at the middle placental attachment and an autolysed fetus free in the abdomen were present. Death was attributed to hypovolemic and endotoxemic shock after uterine rupture. Myometrium adjacent to the rupture and in the left uterine horn was subdivided into irregular pseudolobules by fibrous connective tissue tracts containing small endometrial glandular acini suggestive of adenomyosis, which may have facilitated uterine rupture. This is the first reported case of dystocia-induced uterine rupture and of adenomyosis in a wild dog.

Perspective sur les ruptures d’approvisionnement de médicaments en établissement de santé de 2006 à 2010

PubMed Central

Bussières, Jean-François; Chiveri, Andrei; Lebel, Denis

2011-01-01

RÉSUMÉ Contexte: Si les ruptures d’approvisionnement de médicaments font partie de la réalité de la pratique pharmaceutique depuis plusieurs décennies, elles deviennent une préoccupation quotidienne pour les pharmaciens dans les années 2000 et dépassent les frontières de la littérature pharmaceutique. Objectif: L’objectif principal de cette étude était de quantifier le nombre de médicaments en rupture de stock par année et la durée de ces interruptions. L’objectif secondaire visait à décrire le nombre de médicaments en rupture de stock par fabricant et par classe thérapeutique. Méthode: Cette étude descriptive et rétrospective des ruptures d’approvisionnement en médicaments a porté sur l’ensemble des médicaments à contrat pour les hôpitaux des régions administratives de Montréal, de Laval et de l’Estrie, au Québec. Le nombre de ruptures de stocks, le nombre de jours de rupture de stock et leur durée moyenne par année ont été calculés par fabricant et par classe thérapeutique. De plus, la proportion de produits en rupture de stock et la proportion de jours de rupture de stocks ont été déterminées par classe thérapeutique. Les données ont été analysées à l’aide de statistiques descriptives (c.-à-d. somme, moyenne, écart-type, médiane, intervalle). Résultats: Entre le 1er janvier 2006 et le 31 août 2010 (une période de 56 mois), 2400 ruptures de stocks ont été dénombrées pour un total de 258 105 jours de rupture de stocks (durée moyenne de 108 jours, écart-type de 130 jours et intervalle de 5 à 1623 jours). Un total de 70 fabricants étaient impliqués dans la survenue de toutes les ruptures d’approvisionnement de médicaments relevées durant cette période. Cinquante pour cent (50 %) des ruptures de stocks et des jours de rupture de stocks provenaient de quatre fabricants. Les interruptions étudiées touchaient la majorité des classes thérapeutiques de médicaments disponibles sur le marché. Toutefois, 50 % des ruptures de stocks provenaient de trois classes thérapeutiques (médicaments du système nerveux central, agents anti-infectieux et médicaments cardiovasculaires). Conclusion: Il s’agit des premières données canadiennes publiées sur l’étendue des ruptures d’approvisionnement sur le marché hospitalier. L’étude a démontré que les ruptures de stocks touchent la plupart des fabricants et la majorité des classes thérapeutiques. D’autres études sont nécessaires afin d’explorer les causes et les conséquences des ruptures d’approvisionnement en établissements de santé. PMID:22479098

Relation between energy radiation ratio and rupture speed in numerically simulated earthquakes

NASA Astrophysics Data System (ADS)

Noda, H.; Lapusta, N.; Kanamori, H.

2011-12-01

One of the prominent questions in seismology is energy partitioning during an earthquake. Venkataraman and Kanamori [2004] discussed radiation ratio η_R, the ratio of radiated energy E_R to partial strain energy change ΔW_0 which is the total released strain energy minus the energy that would have been dissipated if a fault had slipped at the final stress. They found positive correlation between η_R and rupture speed in large earthquakes, and compared these data with theoretical estimates from simplified models. The relation between η_R and rupture speed is of great interest since both quantities can be estimated independently although there are large uncertainties. We conduct numerical simulations of dynamic ruptures and study the obtained energy partitioning (and η_R) and averaged rupture speeds V_r. So far, we have considered problems based on TPV103 from the SCEC/USGS Spontaneous Rupture Code Verification Project [Harris et al., 2009, http://scecdata.usc.edu/cvws/], which is a 3-D problem with the possibility of remarkable rate weakening at coseismic slip rates caused by flash heating of microscopic asperities [Rice, 1999]. We study the effect of background shear stress level τ_b and the manner in which rupture is arrested, either in rate-strengthening or unbreakable areas of the fault. Note that rupture speed at each fault point is defined when the rupture is still in progress, while η_R is defined after all dynamic processes such as propagation of a rupture front, healing fronts, and seismic waves have been completed. Those complexities may cause a difference from the theoretical estimates based on simple models, an issue we explore in this study. Overall, our simulations produce the relation between η_R and V_r broadly consistent with the study of Venkataraman and Kanamori (2004) for natural earthquakes and the corresponding theoretical estimates. The model by Mott [1948] agrees best with the cases studied so far, although it is not rigorously correct [Freund, 1990]. For example, a case which is similar to TPV103 except in the nucleation procedure yields a pulse-like rupture with a spatially averaged rupture speed V_r = 0.59 c_s and η_R = 0.32, while the theoretical estimates [Fossum and Freund, 1975 for mode II and Kostrov, 1966; Ehselby, 1969 for mode III] predict η_R of about 0.5 for this rupture speed. This difference is not significant compared with the large observational error. As τ_b increases, V_r increases monotonically, while η_R exhibits more complex behavior: it increases with τ_b for pulse-like ruptures, decreases by about 0.1 at the transition to crack-like ruptures, and then increases again. Frictional dissipation is significant when a rupture front reaches a rate-strengthening region. If the barrier is changed to an unbreakable region, η_R decreases and V_r/c_s increases at most by 0.3 and 0.1, respectively. Although sharper arrest of rupture causes larger E_R per seismic moment due to the stopping phases, ΔW_0 per seismic moment increases more remarkably due to large wavenumber components in final slip distribution.

Patients with an Achilles tendon re-rupture have long-term functional deficits in function and worse patient-reported outcome than primary ruptures.

PubMed

Westin, Olof; Nilsson Helander, Katarina; Grävare Silbernagel, Karin; Samuelsson, Kristian; Brorsson, Annelie; Karlsson, Jón

2018-04-24

The aim of this study was to perform a long-term follow-up of patients treated for an Achilles tendon re-rupture, using established outcome measurements for tendon structure, lower extremity function and symptoms, and to compare the results with those for the uninjured side. A secondary aim was to compare the outcome with that of patients treated for primary ruptures. The hypotheses were that patients with a re-rupture recover well, and have similar long-term outcome as primary ruptures. Twenty patients (4 females) with a mean (SD) age of 44 (10.9) years, ranging from 24 to 64, were included. The patients were identified by reviewing the medical records of all Achilles tendon ruptures at Sahlgrenska University Hospital and Kungsbacka Hospital, Sweden, between 2006 and 2016. All patients received standardised surgical treatment and rehabilitation. The mean (SD) follow-up was 51 (38.1) months. A test battery of validated clinical and functional tests, patient-reported outcome measurements and measurements of tendon elongation were performed at the final follow-up. This cohort was then compared with the 2-year follow-up results from a previous randomised controlled trial of patients treated for primary Achilles tendon rupture. There were deficits on the injured side compared with the healthy side in terms of heel-rise height (11.9 versus 12.5 cm, p = 0.008), repetitions (28.5 versus 31.7, p = 0.004) and drop-jump height (13.2 versus 15.1 cm, p = 0.04).  There was a significant difference in calf circumference (37.1 versus 38.4 cm, p =< 0.001) and ankle dorsiflexion on the injured side compared with the healthy side (35.3° versus 40.8°, p = 0.003). However, no significant differences were found in terms of tendon length 22.5 (2.5) cm on the injured side and 21.8 (2.8) cm on the healthy side. Compared with primary ruptures, the re-rupture cohort obtained significantly worse results for the Achilles tendon total rupture score, with a mean of 78 (21.2) versus 89.5 (14.6) points, (p = 0.007). The re-ruptures showed a higher mean LSI heel-rise height, 94.7% (9.3%) versus 83.5% (11.7%) (p = < 0.0001), and superior mean LSI eccentric-concentic power, 110.4% (49.8%) versus 79.3% (21%) (p = 0.001), than the primary ruptures. The results of this study indicate that patients with an Achilles tendon re-rupture had continued symptoms and functional deficits on the injured side, after a long-term follow-up. Patients with an Achilles tendon re-rupture had worse patient-reported outcomes but similar or superior functional results compared with patients with primary ruptures. Case series, Level IV.

Fan-head shear rupture mechanism as a source of off-fault tensile cracking

NASA Astrophysics Data System (ADS)

Tarasov, Boris

2016-04-01

This presentation discusses the role of a recently identified fan-head shear rupture mechanism [1] in the creation of off-fault tensile cracks observed in earthquake laboratory experiments conducted on brittle photoelastic specimens [2,3]. According to the fan-mechanism the shear rupture propagation is associated with consecutive creation of small slabs in the fracture tip which, due to rotation caused by shear displacement of the fracture interfaces, form a fan-structure representing the fracture head. The fan-head combines such unique features as: extremely low shear resistance (below the frictional strength) and self-sustaining tensile stress intensification along one side of the interface. The variation of tensile stress within the fan-head zone is like this: it increases with distance from the fracture tip up to a maximum value and then decreases. For the initial formation of the fan-head high local stresses corresponding to the fracture strength should be applied in a small area, however after completions of the fan-head it can propagate dynamically through the material at low shear stresses (even below the frictional strength). The fan-mechanism allows explaining all unique features associated with the off-fault cracking process observed in photoelastic experiments [2,3]. In these experiments spontaneous shear ruptures were nucleated in a bonded, precut, inclined and pre-stressed interface by producing a local pressure pulse in a small area. Isochromatic fringe patterns around a shear rupture propagating along bonded interface indicate the following features of the off-fault tensile crack development: tensile cracks nucleate and grow periodically along one side of the interface at a roughly constant angle (about 80 degrees) relative to the shear rupture interface; the tensile crack nucleation takes place some distance behind the rupture tip; with distance from the point of nucleation tensile cracks grow up to a certain length within the rupture head zone; behind this zone static microcracks are left in the wake of the propagating rupture. Unfortunately, the modern technology used in these experiments is not able to identify the shear rupture mechanism itself operated within the narrow rupture interface. However, a special analysis of side effects accompanying the shear rupture propagation (including the off-fault tensile cracking) allows supposing that the failure process was governed by the fan-mechanism. 1. Tarasov, B.G. 2014. Hitherto unknown shear rupture mechanism as a source of instability in intact hard rocks at highly confined compression. Tectonophysics, 621, 69-84. 2. Griffith, W.A., Rosakis, A., Pollard, D.D. and Ko, C.W., 2009. Dynamic rupture experiments elucidate tensile crack development during propagating earthquake ruptures, Geology, pp 795-798. 3. Ngo, D., Huang, Y., Rosakis, A., Griffith, W.A., Pollard D. 2012. Off-fault tensile cracks: A link between geological fault observations, lab experiments, and dynamic rupture models. Journal of Geophysical Research, vol. 117, B01307, doi: 10.1029/2011JB008577 (2012).

The Modulus of Rupture from a Mathematical Point of View

NASA Astrophysics Data System (ADS)

Quintela, P.; Sánchez, M. T.

2007-04-01

The goal of this work is to present a complete mathematical study about the three-point bending experiments and the modulus of rupture of brittle materials. We will present the mathematical model associated to three-point bending experiments and we will use the asymptotic expansion method to obtain a new formula to calculate the modulus of rupture. We will compare the modulus of rupture of porcelain obtained with the previous formula with that obtained by using the classic theoretical formula. Finally, we will also present one and three-dimensional numerical simulations to compute the modulus of rupture.