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| Organ-specific lymphangiectasia, arrested lymphatic sprouting, and maturation defects resulting from gene-targeting of the PI3K regulatory isoforms p85alpha, p55alpha, and p50alpha. Dev Dyn. 2009 Aug 24 Mouta-Bellum C, Kirov A, Miceli-Libby L, Mancini ML, Petrova TV, Liaw L, Prudovsky I, Thorpe PE, Miura N, Cantley LC, Alitalo K, Fruman DA, Vary CP. Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine. Funded by:
NIH; Grant Number: AI050831
NIH COBRE program of the National Center for Research Resources; Grant Number: P20 RR 15555
National Heart, Lung, and Blood Institute | lymphangiogenesis • phosphatidyl inositol 3-kinase |
The phosphoinositide 3-kinase (PI3K) family has multiple vascular functions, but the specific regulatory isoform supporting lymphangiogenesis remains unidentified. Here, we report that deletion of the Pik3r1 gene, encoding the regulatory subunits p85alpha, p55alpha, and p50alpha impairs lymphatic sprouting and maturation, and causes abnormal lymphatic morphology, without major impact on blood vessels. Pik3r1 deletion had the most severe consequences among gut and diaphragm lymphatics, which share the retroperitoneal anlage, initially suggesting that the Pik3r1 role in this vasculature is anlage-dependent. However, whereas lymphatic sprouting toward the diaphragm was arrested, lymphatics invaded the gut, where remodeling and valve formation were impaired. Thus, cell-origin fails to explain the phenotype. Only the gut showed lymphangiectasia, lymphatic up-regulation of the transforming growth factor-beta co-receptor endoglin, and reduced levels of mature vascular endothelial growth factor-C protein. Our data suggest that Pik3r1 isoforms are required for distinct steps of embryonic lymphangiogenesis in different organ microenvironments, whereas they are largely dispensable for hemangiogenesis. Developmental Dynamics Wiley InterScience http://www3.interscience.wiley.com/journal/122573765/abstract?CRETRY=1&SRETRY=0 | | |
| Outcome of children with pulmonary lymphangiectasis. Pediatr Pulmonol. 2009 Apr Mettauer N, Agrawal S, Pierce C, Ashworth M, Petros A. Paediatric Intensive Care Unit, Great Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, United Kingdom. nmettauer@bluewin.ch Pulmonary lymphangiectasis (PL) is a very rare developmental defect of the lungs, which has previously been reported to have a very poor prognosis. However, recent reports have suggested improved outcomes, possibly as a result of advances in neonatal and pediatric intensive care medicine. We performed a retrospective study on the outcome of children with PL between 1990 and 2008 referred to our tertiary center. Seven patients with histologically proven PL were identified over the 18-year period. Six patients presented in the neonatal period and one patient at 7 months of age, all of them requiring intensive care treatment. Three neonatal patients required extracorporeal membrane oxygenation (ECMO). Six of the seven patients did not survive including all those who received ECMO. Two of the six non-survivors died of other causes than their underlying disease. The only survivor had an antenatal diagnosis of hydrops and required in utero chest drain insertion. Postnatally he was managed with maximal medical treatment for bilateral pleural effusions and persistent pulmonary hypertension. A 7-month follow-up showed this infant to be doing well. In conclusion overall the prognosis of congenital PL remains poor. The one survivor demonstrates that this condition is survivable with aggressive intervention and as current evidence suggests gradual improvement of symptoms may occur over time, and that maximal medical treatment remains warranted. 2009 Wiley-Liss, Inc. | | |
| Liquid Nitrogen Cryotherapy of Lymphangiectasia. Cornea. 2009 Apr 29 Fraunfelder FW. From the Casey Eye Institute, Oregon Health & Science University, Portland, OR. PURPOSE: To report a case of lymphangiectasia successfully treated with liquid nitrogen cryotherapy. METHODS: A 1.5-mm Brymill cryoprobe (Brymill Cryogenic Systems, Ellington, CT) was applied in a double freeze-thaw method after an incisional biopsy of a portion of the conjunctiva. Freeze times were 1-2 seconds with thawing of 5-10 seconds between freezes. RESULTS: A 64-year-old white man had symptoms of bilateral epiphora, eye irritation, and episodic blurred vision that was worse in the right eye. Ocular examination revealed inferior chemotic conjunctiva in the right eye and redundant conjunctiva in the left eye without chemosis. Marsupialization and liquid nitrogen cryotherapy were performed on the right eye, and the symptoms and signs resolved within 2 weeks. One year after cryotherapy, the patient has had no more eye symptoms or signs of lymphangiectasia. CONCLUSION: Liquid nitrogen cryotherapy may be an effective alternative to surgery in the treatment of conjunctival lymphangiectasia. PMID: 19421031 [PubMed - as supplied by publisher] | | |
| The efficacy of double balloon enteroscopy for patients with intestinal lymphangiectasia, case report of primary intestinal lymphangiectasia. Nippon Shokakibyo Gakkai Zasshi. 2008 Nov Yakami Y, Watanabe K, Kameda N, Machida H, Okazaki H, Yamagami H, Shiba M, Fujiwara Y, Oshitani N, Arakawa T.Department of Gastroenterology, Graduate School of Medicine, Osaka City University. A 31-year-old man has visited our hospital, complaining diarrhea and leg edema. Blood test showed hypoalbuminea, but we couldn't find the reason by several examinations. Therefore, we performed double balloon enteroscopy, and intestinal lymphangiectasia was diagnosed histologically by biopsy. It's useful and effective to perform double balloon enteroscopy and histological examination for the unknown origin case of protein loosing enteropathy. J-Stage PubMed - English | | |
| Magnetic resonance imaging as a new method to diagnose protein losing enteropathy Lymphology. 2008 Sep Liu NF, Lu Q, Wang CG, Zhou JG.Department of Plastic & Reconstructive Surgery, Shanghai 9th People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China. The main cause of protein losing enteropathy (PLE) in children is intestinal lymphangiectasia. PLE is commonly diagnosed with radiotracer scintigraphy. We report the use of magnetic resonant imaging in diagnosis of a child with primary PLE. MRI clearly revealed abnormality in intestine and mesentery and dilated thoracic duct and mesenteric lymphatic as well as prominent subcutaneous lymphatics in the extremity. We conclude that MRI is a useful tool in diagnose of primary PLE. PMID: 19013878 [PubMed - in process] | | |
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