The Experts below are selected from a list of 66 Experts worldwide ranked by ideXlab platform
Maureen J Osullivan - One of the best experts on this subject based on the ideXlab platform.
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p474 extra hepatic Bile Duct Hamartoma an unusual cause for anterior abdominal wall defect
Archives of Disease in Childhood, 2019Co-Authors: Abhidhamma Kaninde, Sheiniz Giva, Maragaret M Moran, Salvatore Cascio, Erinn S Mcgrath, Maureen J OsullivanAbstract:We report a case of a baby girl born at 35 weeks gestation with an unusual para-umbilical lesion associated with an anterior abdominal wall defect. Shortly after birth, she was noted to have a small polypoid lesion to the right of her umbilicus. The lesion measured around 1 cm in length and had a small area of ulceration at the tip. Her systemic examination was otherwise normal. Abdominal ultrasound examination was suggestive of a defect in the anterior abdominal wall. An artery and vein could be seen passing through the defect into the lesion. A rounded echogenic structure was noted to be passing through the abdominal wall defect consistent with a loop of bowel. At laparotomy, a Hamartomatous lesion was seen with an artery and vein extending back to the liver. The bowel was intact and there was no bowel within the lesion. The lesion was excised, with ligation of the blood vessels, and closure of the abdominal wall defect. Screening for other midline anomalies revealed a left-sided grade 1 intraventricular haemorrhage and a small fenestrated atrial septal defect. Genetic analysis showed a normal microarray and no evidence of Beckwith-Wiedemann syndrome. Histopathological examination of the tissue showed extensively ulcerated skin. The outline was polypoid with granulation tissue as a base. Deep to this were Bile Ducts, venules, and arterioles. These features were Hamartomatous suggesting an extra-hepatic Bile Duct Hamartoma. The lesion was malformative and not neoplastic. Discussion While it is unusual to find biliary tree Hamartomas presenting in the neonatal period, as most of them are asymptomatic and insidious, the extra-hepatic location of this Hamartoma is extremely rare. Redston et al. reported on autopsy findings of 2843 patients and calculated the prevalence of biliary Hamartomas as 5.6% in adults and 0.9% in children. They also found a high incidence of biliary Hamartomas with autosomal dominant polycystic kidney disease. They can be solitary or multiple. Multiple Bile Duct Hamartomas are also known as Von Meyenburg complexes. They are a benign Ductal plate malformation of smaller interlobular Ducts. Although these lesions are often described as benign anecdotally there are reports mentioning malignant transformation. Conclusion We report a very rare case of extra-hepatic Bile Duct Hamartoma presenting as an anterior abdominal wall defect in the neonatal period.
Duojia Pan - One of the best experts on this subject based on the ideXlab platform.
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the merlin nf2 tumor suppressor functions through the yap oncoprotein to regulate tissue homeostasis in mammals
Developmental Cell, 2010Co-Authors: Nailing Zhang, Haibo Bai, Karen K David, Jixin Dong, Yonggang Zheng, Jing Cai, Marco Giovannini, Pentao Liu, Robert A Anders, Duojia PanAbstract:The conserved Hippo signaling pathway regulates organ size in Drosophila and mammals. While a core kinase cascade leading from the protein kinase Hippo (Hpo) (Mst1 and Mst2 in mammals) to the transcription coactivator Yorkie (Yki) (YAP in mammals) has been established, upstream regulators of the Hippo kinase cascade are less well defined, especially in mammals. Using conditional knockout mice, we demonstrate that the Merlin/NF2 tumor suppressor and the YAP oncoprotein function antagonistically to regulate liver development. While inactivation of Yap led to loss of hepatocytes and biliary epithelial cells, inactivation of Nf2 led to hepatocellular carcinoma and Bile Duct Hamartoma. Strikingly, the Nf2-deficient phenotypes in multiple tissues were largely suppressed by heterozygous deletion of Yap, suggesting that YAP is a major effector of Merlin/NF2 in growth regulation. Our studies link Merlin/NF2 to mammalian Hippo signaling and implicate YAP activation as a mediator of pathologies relevant to Neurofibromatosis 2.
Nailing Zhang - One of the best experts on this subject based on the ideXlab platform.
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the merlin nf2 tumor suppressor functions through the yap oncoprotein to regulate tissue homeostasis in mammals
Developmental Cell, 2010Co-Authors: Nailing Zhang, Haibo Bai, Karen K David, Jixin Dong, Yonggang Zheng, Jing Cai, Marco Giovannini, Pentao Liu, Robert A Anders, Duojia PanAbstract:The conserved Hippo signaling pathway regulates organ size in Drosophila and mammals. While a core kinase cascade leading from the protein kinase Hippo (Hpo) (Mst1 and Mst2 in mammals) to the transcription coactivator Yorkie (Yki) (YAP in mammals) has been established, upstream regulators of the Hippo kinase cascade are less well defined, especially in mammals. Using conditional knockout mice, we demonstrate that the Merlin/NF2 tumor suppressor and the YAP oncoprotein function antagonistically to regulate liver development. While inactivation of Yap led to loss of hepatocytes and biliary epithelial cells, inactivation of Nf2 led to hepatocellular carcinoma and Bile Duct Hamartoma. Strikingly, the Nf2-deficient phenotypes in multiple tissues were largely suppressed by heterozygous deletion of Yap, suggesting that YAP is a major effector of Merlin/NF2 in growth regulation. Our studies link Merlin/NF2 to mammalian Hippo signaling and implicate YAP activation as a mediator of pathologies relevant to Neurofibromatosis 2.
Robert A Anders - One of the best experts on this subject based on the ideXlab platform.
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the merlin nf2 tumor suppressor functions through the yap oncoprotein to regulate tissue homeostasis in mammals
Developmental Cell, 2010Co-Authors: Nailing Zhang, Haibo Bai, Karen K David, Jixin Dong, Yonggang Zheng, Jing Cai, Marco Giovannini, Pentao Liu, Robert A Anders, Duojia PanAbstract:The conserved Hippo signaling pathway regulates organ size in Drosophila and mammals. While a core kinase cascade leading from the protein kinase Hippo (Hpo) (Mst1 and Mst2 in mammals) to the transcription coactivator Yorkie (Yki) (YAP in mammals) has been established, upstream regulators of the Hippo kinase cascade are less well defined, especially in mammals. Using conditional knockout mice, we demonstrate that the Merlin/NF2 tumor suppressor and the YAP oncoprotein function antagonistically to regulate liver development. While inactivation of Yap led to loss of hepatocytes and biliary epithelial cells, inactivation of Nf2 led to hepatocellular carcinoma and Bile Duct Hamartoma. Strikingly, the Nf2-deficient phenotypes in multiple tissues were largely suppressed by heterozygous deletion of Yap, suggesting that YAP is a major effector of Merlin/NF2 in growth regulation. Our studies link Merlin/NF2 to mammalian Hippo signaling and implicate YAP activation as a mediator of pathologies relevant to Neurofibromatosis 2.
Haibo Bai - One of the best experts on this subject based on the ideXlab platform.
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the merlin nf2 tumor suppressor functions through the yap oncoprotein to regulate tissue homeostasis in mammals
Developmental Cell, 2010Co-Authors: Nailing Zhang, Haibo Bai, Karen K David, Jixin Dong, Yonggang Zheng, Jing Cai, Marco Giovannini, Pentao Liu, Robert A Anders, Duojia PanAbstract:The conserved Hippo signaling pathway regulates organ size in Drosophila and mammals. While a core kinase cascade leading from the protein kinase Hippo (Hpo) (Mst1 and Mst2 in mammals) to the transcription coactivator Yorkie (Yki) (YAP in mammals) has been established, upstream regulators of the Hippo kinase cascade are less well defined, especially in mammals. Using conditional knockout mice, we demonstrate that the Merlin/NF2 tumor suppressor and the YAP oncoprotein function antagonistically to regulate liver development. While inactivation of Yap led to loss of hepatocytes and biliary epithelial cells, inactivation of Nf2 led to hepatocellular carcinoma and Bile Duct Hamartoma. Strikingly, the Nf2-deficient phenotypes in multiple tissues were largely suppressed by heterozygous deletion of Yap, suggesting that YAP is a major effector of Merlin/NF2 in growth regulation. Our studies link Merlin/NF2 to mammalian Hippo signaling and implicate YAP activation as a mediator of pathologies relevant to Neurofibromatosis 2.