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Dive into the research topics where Sarah Keating is active.

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Featured researches published by Sarah Keating.


Human Pathology | 1985

Undifferentiated (embryonal) sarcoma of the liver:: Ultrastructural and immunohistochemical similarities with malignant fibrous histiocytoma

Sarah Keating; Glenn P. Taylor

Two undifferentiated (embryonal) sarcomas of liver were studied ultrastructurally and immunohistochemically. Electron microscopic examination of the pleomorphic tumor cells revealed fibroblastic and histiocytic characteristics. There were no specific findings to support rhabdomyoblastic, leiomyoblastic, or epithelial differentiation. Cytoplasmic peroxidase-antiperoxidase (PAP) immunohistochemical staining for vimentin, alpha1-antitrypsin, and alpha1-antichymotrypsin was found. No staining for epidermal or internal organ cytokeratins, desmin, myoglobin, or alpha-fetoprotein was observed. The ultrastructural correlates of the cytoplasmic periodic acid-Schiff-positive, diastase-resistant hyaline globules were large, membrane-bound, heterogenous electron-dense inclusions, probably lysosomal in origin. These inclusions did not react on either alpha1-antitrypsin or alpha1-antichymotrypsin PAP staining. Tumor specimens from two metastatic sites were also examined. Neither contained the ducts or cysts that characterized the primary tumor. These studies confirm the mesenchymal nature of this uncommon childhood neoplasm and support the suggestion that the cytoplasmic hyaline globules represent a degenerative phenomenon. There are ultrastructural and immunohistochemical similarities with malignant fibrous histiocytoma.


Developmental Biology | 2008

Altered gene expression and methylation of the human chromosome 11 imprinted region in small for gestational age (SGA) placentae

Lin Guo; Sanaa Choufani; Jose Carlos Ferreira; Adam C. Smith; David Chitayat; Cheryl Shuman; Ruchita Uxa; Sarah Keating; John Kingdom; Rosanna Weksberg

Imprinted genes are known to be crucial for placental development and fetal growth in mammals, but no primary epigenetic abnormality in placenta has been documented to compromise human fetal growth. Imprinted genes demonstrate parent-of-origin-specific allelic expression that is epigenetically regulated i.e. extrinsic to the primary DNA sequence. To undertake an epigenetic analysis of poor fetal growth in placentae and cord blood tissues, we first established the tissue-specific patterns of methylation and imprinted gene expression for two imprinting clusters (KvDMR and H19 DMR) on chromosome 11p15 in placentae and neonatal blood for 20 control cases and 24 Small for Gestational Age (SGA) cases. We confirmed that, in normal human placenta, the H19 promoter is unmethylated. In contrast, most other human tissues show paternal methylation. In addition, we showed that the IGF2 DMR2, also paternally methylated in most human tissues, exhibits hypomethylation in placentae. However, in neonatal blood DNA, these two regions maintain the differential methylation status seen in most other tissues. Significantly, we have been able to demonstrate that placenta does maintain differential methylation at the imprinting control regions H19 DMR and KvDMR. Of note, in one SGA placenta, we found a methylation alteration at the H19 DMR and concomitant biallelic expression of the H19 gene, suggesting that loss of imprinting at H19 is one cause of poor fetal growth in humans. Of particular interest, we demonstrated also a decrease in IGF2 mRNA levels in all SGA placentae and showed that the decrease is, in most cases, independent of H19 regulation.


Archives of Pathology & Laboratory Medicine | 2016

Sampling and Definitions of Placental Lesions: Amsterdam Placental Workshop Group Consensus Statement

T. Yee Khong; Eoghan Mooney; Ilana Ariel; Nathalie C.M. Balmus; Theonia K. Boyd; Marie Anne Brundler; Hayley Derricott; Margaret J. Evans; Ona Faye-Petersen; John Gillan; Alex E.P. Heazell; Debra S. Heller; Suzanne M. Jacques; Sarah Keating; Peter Kelehan; Ann Maes; Eileen McKay; Terry K. Morgan; Peter G. J. Nikkels; W. Tony Parks; Raymond W. Redline; Irene Scheimberg; Mirthe H. Schoots; Nj Sebire; Albert Timmer; Gitta Turowski; J. Patrick van der Voorn; Ineke Van Lijnschoten; Sanne J. Gordijn

CONTEXT -The value of placental examination in investigations of adverse pregnancy outcomes may be compromised by sampling and definition differences between laboratories. OBJECTIVE -To establish an agreed-upon protocol for sampling the placenta, and for diagnostic criteria for placental lesions. Recommendations would cover reporting placentas in tertiary centers as well as in community hospitals and district general hospitals, and are also relevant to the scientific research community. DATA SOURCES -Areas of controversy or uncertainty were explored prior to a 1-day meeting where placental and perinatal pathologists, and maternal-fetal medicine specialists discussed available evidence and subsequently reached consensus where possible. CONCLUSIONS -The group agreed on sets of uniform sampling criteria, placental gross descriptors, pathologic terminologies, and diagnostic criteria. The terminology and microscopic descriptions for maternal vascular malperfusion, fetal vascular malperfusion, delayed villous maturation, patterns of ascending intrauterine infection, and villitis of unknown etiology were agreed upon. Topics requiring further discussion were highlighted. Ongoing developments in our understanding of the pathology of the placenta, scientific bases of the maternofetoplacental triad, and evolution of the clinical significance of defined lesions may necessitate further refinements of these consensus guidelines. The proposed structure will assist in international comparability of clinicopathologic and scientific studies and assist in refining the significance of lesions associated with adverse pregnancy and later health outcomes.


American Journal of Obstetrics and Gynecology | 2008

Determinants of adverse perinatal outcome in high-risk women with abnormal uterine artery Doppler images

Meghana Toal; Sarah Keating; Geoff Machin; Jodie M Dodd; S. Lee Adamson; Rory Windrim; John Kingdom

OBJECTIVE The purpose of this study was to evaluate the prognostic role of placental ultrasound imaging at 19-23 weeks of gestation in clinically high-risk women with abnormal uterine artery Doppler (UTAD). STUDY DESIGN Placentas of 60 women with abnormal UTAD were examined at 19-23 weeks of gestation for shape and texture abnormalities. Findings were correlated with clinical outcomes (preterm delivery at <32 weeks of gestation; birth weight <10th percentile [small for gestational age]; preeclampsia/hemolysis, elevated liver enzymes, low platelets; early-onset intrauterine growth restriction with abnormal umbilical artery Doppler; and intrauterine fetal death) and maternal serum screening data. Placental disease was reviewed by 2 perinatal pathologists. RESULTS Women with abnormal placental shape at 19-23 weeks of gestation (n = 28) had higher odds of intrauterine fetal death (odds ratio, 4.5; 95% CI, 1.3-15.6), delivery at <32 weeks of gestation (odds ratio, 4.7; 95% CI, 1.6-14.1]), and intrauterine growth restriction (odds ratio, 4.7; 95% CI, 1.4-15.1]) than did the women with a normal placental shape. Thirty-two of 41 placentas (74%) weighed <10th percentile, and 36 of 43 placentas (83%) had ischemic-thrombotic pathologic condition. There was no association between abnormal placental shape at 19-23 weeks of gestation and placental weight, but 5 of 6 placentas that were <10 cm long were <10th percentile for weight at delivery. There was a poor correlation between measures of ultrasound texture at 19-23 weeks of gestation and the presence of specific lesions at delivery. CONCLUSION Combined abnormal UTAD and placental dysmorphologic condition before fetal viability identifies a subset of women who are at risk of adverse outcomes. Placental size is critical in the determination of the outcome in this situation because of the very high prevalence of destructive lesions, although present methods of placental imaging have significant limitations.


Pediatric and Developmental Pathology | 2006

The Prevalence of Chronic Deciduitis in Cases of Preterm Labor without Clinical Chorioamnionitis

Nadeen Edmondson; Alan D. Bocking; Geoffrey A. Machin; Rose Rizek; Carole S. Watson; Sarah Keating

Preterm labor is a major cause of perinatal mortality and morbidity, and in approximately 30% of cases a clinical cause is not identified. Acute chorioamnionitis is found histologically in a significant percentage of placentas from preterm deliveries, and the mother is often asymptomatic. Although such subclinical acute chorioamnionitis is known to play a role in preterm labor, this study explores the hypothesis that chronic deciduitis with plasma cells is seen more frequently in cases of preterm labor than in control placentas. Thirty-nine singleton placentas from patients with idiopathic preterm labor were examined microscopically and compared in a blinded fashion with 39 gestational age-matched control placentas. Cases of clinical acute chorioamnionitis and known chronic maternal diseases were excluded. Thirty-nine control singleton placentas were obtained from patients undergoing induction of labor for fetal structural abnormalities, excluding aneuploidy. The presence or absence of acute chorioamnionitis, acute fetal inflammatory response, chronic deciduitis, chronic villitis, infarction, and decidual vasculopathy was noted. Immunohistochemical staining was undertaken to further define leukocyte subtypes. Forty-one percent of cases and 15% of controls showed chronic deciduitis (P = 0.022). Forty-six percent of cases and 18% of controls showed histologic acute chorioamnionitis (P = 0.015). There were 8 cases demonstrating acute fetal inflammatory response but only 1 control (P = 0.029). Little difference was seen in the distribution of lymphocyte subsets between cases and control placentas. Our findings suggest that chronic deciduitis plays a role in the etiology of some cases of preterm labor.


American Journal of Medical Genetics Part A | 2011

From VACTERL-H to heterotaxy: variable expressivity of ZIC3-related disorders.

Brian Hon-Yin Chung; Lisa G. Shaffer; Sarah Keating; Joan Johnson; Bret Casey; David Chitayat

The ZIC3 gene encodes a zinc finger protein which functions as a transcription factor in early stages of left‐right body axis formation. Mutations in this X‐linked gene cause a variety of clinical manifestations including heterotaxy, complex or isolated heart defect as well as other midline urogenital and hindgut malformations. We report a four generation family with X‐linked heterotaxy associated with a deletion of the ZIC3 gene at Xq26.3. The index fetus of our proband showed classical features of heterotaxy while her maternal uncle and one brother had imperforate anus and her other brother had features suggestive of VACTERL‐H without heterotaxy. A 1.4 Mb deletion in Xq26.3 including the ZIC3 gene was found in the fetus. Six females in the family were found to be asymptomatic carriers. Our report indicates that some of the cases with VACTERL‐H syndrome may be caused by a mutation or deletion of the ZIC3 gene.


American Journal of Medical Genetics Part A | 2010

Hypospadias in Males With Intrauterine Growth Restriction Due To Placental Insufficiency: The Placental Role in the Embryogenesis of Male External Genitalia

Yoav Yinon; John Kingdom; Leslie Proctor; Edmond Kelly; Joao L. Pippi Salle; Diane K. Wherrett; Sarah Keating; Ori Nevo; David Chitayat

Our aim was to define the association between early onset intra‐uterine growth restriction (IUGR) due to placental insufficiency and hypospadias in males. We prospectively studied a cohort of small‐for‐gestational age (SGA) male infants with hypospadias managed by a multidisciplinary team over a 5‐year period. Thirty SGA male infants were diagnosed with hypospadias/abnormal genitalia after birth, and four of them were diagnosed antenatally. Five cases occurred in the smaller pair of discordant IUGR twins, where the larger co‐twin had normal male genitalia. Serial ultrasounds demonstrated features of early‐onset IUGR in all cases at a median gestational age of 21 weeks (range 14–31weeks). Twenty‐one (70%) pregnancies were subsequently complicated by absent/reversed end‐diastolic flow in the umbilical arteries indicating severe IUGR, and 17 (57%) women developed severe pre‐eclampsia. There were 27 (90%) live births at a median gestational age of 31 weeks (range 27–37); 23 (77%) of the neonates had birth weights <3rd centile. All newborns had normal male karyotypes. In 62% (18/29) the hypospadias was severe. A correlation was found between the severity of the IUGR and the severity of hypospadias as significantly more infants with severe hypospadias were less than the 3rd centile compared to the mild–moderate hypospadias group: 94% (17/18) versus 55% (6/11), respectively (P = 0.02). In conclusion, SGA male newborns with hypospadias exhibit a high rate of early‐onset severe IUGR due to placental insufficiency. Early placental development likely influences male external genitalia formation. Careful sonographic evaluation of the genitalia is advised when early‐onset placentally mediated IUGR is found.


Epigenetics | 2011

WNT2 promoter methylation in human placenta is associated with low birthweight percentile in the neonate

Jose Carlos Ferreira; Sanaa Choufani; Daria Grafodatskaya; Darci T. Butcher; Chunhua Zhao; David Chitayat; Cheryl Shuman; John Kingdom; Sarah Keating; Rosanna Weksberg

Neonates with birthweights below the tenth percentile for gestational age are considered small for gestational age (SGA). Such infants have an increased risk for perinatal mortality and morbidity as well as an increased lifetime risk for adult onset disorders. Low birth weight percentile is etiologically heterogeneous and may result from maternal, fetal, placental and environmental factors. However, the molecular determinants of human SGA are not well elucidated. We proposed that fetal growth potential could be negatively impacted by the epigenetic dysregulation of specific genes in the placenta. Using methyl DNA immunoprecipitation coupled with Agilent CpG island microarrays, we analyzed the differences in DNA methylation between placentas of eight SGA neonates and eight controls with birthweight percentiles above the tenth percentile. We identified several candidate genomic regions with differential DNA methylation between the two groups. The DNA methylation differences identified in the promoter of the WNT2 gene were prioritized for further study in an extended cohort of 170 samples given the important function of this gene in mouse placental development and its high expression in human placenta. High WNT2 promoter methylation (WNT2PrMe) was found only in placental tissue and not in the cord blood of the fetus. It was significantly associated with reduced WNT2 expression in placenta and with low birthweight percentile in the neonate. Our results show that WNT2 expression can be epigenetically downregulated in the placenta by DNA methylation of its promoter and that high WNT2PrMe is an epigenetic variant that is associated with reduced fetal growth potential. Note: All of the array data in the manuscript can be accessed from the Gene Expression Omnibus (GEO) NCBI database under GEO accession number GSE22326.


American Journal of Medical Genetics Part A | 2008

Chondrodysplasia punctata associated with maternal autoimmune diseases: Expanding the spectrum from systemic lupus erythematosus (SLE) to mixed connective tissue disease (MCTD) and scleroderma report of eight cases†

David Chitayat; Sarah Keating; Dina J. Zand; Teresa Costa; Elaine H. Zackai; Earl D. Silverman; George E. Tiller; Sheila Unger; Stephen F. Miller; John Kingdom; Ants Toi; Cynthia J. Curry

Chondrodysplasia punctata (CDP) is etiologically a heterogeneous condition and has been associated with single gene disorders, chromosome abnormalities and teratogenic exposures. The first publication of the association between CDP and maternal autoimmune connective tissue disorder was by Curry et al. 1993 ]. Chondrodysplasia punctata associated with maternal collagen vascular disease. A new etiology? Presented at the David W. Smith Workshop on Morphogenesis and Malformations, Mont Tremblant, Quebec, August 1993] and subsequently, other cases have been reported. We report on eight cases of maternal collagen vascular disease associated with fetal CDP and included the cases reported by Curry et al. 1993 . Chondrodysplasia punctata associated with maternal collagen vascular disease. A new etiology? Presented at the David W. Smith Workshop on Morphogenesis and Malformations, Mont Tremblant, Quebec, August 1993] and Costa et al. [1993]. Maternal systemic lupus erythematosis (SLE) and chondrodysplasia punctata in two infants. Coincidence or association? 1st Meeting of Bone Dysplasia Society, Chicago, June 1993] which were reported in an abstract form. We suggest that maternal autoimmune diseases should be part of the differential diagnosis and investigation in newborns/fetuses with CDP. Thus, in addition to cardiac evaluation, fetuses/newborn to mothers with autoimmune diseases should have fetal ultrasound/newborn examination and if indicated, X‐rays, looking for absent/hypoplastic nasal bone, brachydactyly, shortened long bones and epiphyseal stippling.


American Journal of Medical Genetics Part A | 2007

The PDAC syndrome (pulmonary hypoplasia/agenesis, diaphragmatic hernia/eventration, anophthalmia/microphthalmia, and cardiac defect) (Spear syndrome, Matthew-Wood syndrome): Report of eight cases including a living child and further evidence for autosomal recessive inheritance†

David Chitayat; Hana Sroka; Sarah Keating; Randall S. Colby; Greg Ryan; Ants Toi; Susan Blaser; Sandra Viero; Louise Devisme; Odile Boute-Benejean; Sylvie Manouvrier-Hanu; Geert Mortier; Bart Loeys; Anita Rauch; Pierre Bitoun

The combination of pulmonary agenesis/dysgenesis/hypoplasia, microphthalmia/anophthalmia, and a diaphragmatic defect (agenesis or eventration) is a rare syndrome presumed to have an autosomal recessive mode of inheritance based on a report of affected siblings born to unaffected parents [Seller et al., 1996 ]. The condition is known as Spear syndrome and Matthew‐Wood syndrome, although genetic heterogeneity cannot be ruled out. We report on eight patients with this condition including a living child, three sibs and three isolated cases. Most presented with fetal ultrasound findings of microphthalmia/anophthalmia, and diaphragmatic eventration/hernia and in five, cardiac abnormalities were also found. The earliest detection was at 20 weeks gestation. This is the second report of sibs affected with this condition, which supports an autosomal recessive mode of inheritance. We present the first and only reported living patient with this condition and expand the intrafamilial, interfamilial, and ethnic variability of this condition. We suggest changing the conditions name to PDAC to reflect the most important components of this condition.

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Greg Ryan

University of Toronto

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Ants Toi

University of Toronto

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