Developmental Disorders of the Lymphatics

An information blog for disorders of the lymphatics. For all articles, please click on "Archives" - Due to spammers, I will no longer allow comments, sorry.

Friday, May 25, 2007





“Lymphedema: Empowerment through Knowledge"

October 5-7, 2007
Renaissance Waverly Hotel
2450 Galleria Parkway
Atlanta GA 30339

The Lighthouse Lymphedema Network is pleased to invite you to an outstanding educational and awareness conference this fall! Continuing our annual efforts to increase awareness about lymphedema, we have assembled a terrific group of speakers to provide information on a wide variety of topics for patients, family, caregivers, and professionals. We will also have a large number of our excellent vendor associates present to demonstrate current products for lymphedema care and treatment.

Whether you are newly-diagnosed with lymphedema and eager to get more information about what it is and how it can be treated, or perhaps you are interested in learning what the latest research in this field promises, attendance at our program will definitely be beneficial. [Professionals, remember LLN offers CEUs for attendance.

Our program starts Friday afternoon, October 5, with a pre-conference tour of Sigvaris’ garment manufacturing plant here in Atlanta, and will be followed by a Kick-Off Party from 5:00-7:00 PM. Saturday and Sunday are full of plenary sessions open to everyone, with instructional sessions for both professionals and all other conference attendees.

Program Information Page

For further information, schedule and registration:

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Saturday, May 19, 2007

The Primary Valves in the Initial Lymphatics during Inflammation.

The Primary Valves in the Initial Lymphatics during Inflammation.

Lymphat Res Biol. 2007
Lynch PM,
Delano FA,
Schmid-Schonbein GW.
Department of Bioengineering, University of California San Diego, La Jolla, California., Supported by United States Public Health Service Grant HL 10881.

Background: The primary valve system in the initial lymphatics prevents fluid transport from the initial lymphatics back into the interstitium. The authors hypothesize that since the primary valves are made up of an extraordinarily thin endothelium, they are readily compromised by mechanical or biochemical inflammatory stimuli. Thus, the opening dimension of the primary valves and their ability to prevent reflux into the interstitium during inflammation were investigated.

Methods and Results: Acute inflammation was generated in the intact rat spinotrapezius muscle by suffusion of f-Met-Leu-Phe and platelet-activating factor. Once inflamed, the effective opening dimensions of the primary valves and the transport back out of the initial lymphatics were determined by examining the transport of fluorescent tracers from the interstitium to the lymphatics. Quantum dots and fluorescently labeled albumin readily enter initial lymphatics from the interstitium. The maximum diameter of microspheres that enter the initial lymphatics is between 0.5 mum and 0.8 mum in both control and inflamed tissue. While under control conditions no quantum dots escaped from initial lymphatics back into the interstitium, during inflammation there was extensive escape of quantum dots.

Conclusions: These results suggest that, in acute inflammation, the function of the endothelial barriers in the initial lymphatics may be compromised.

A failure of the primary lymphatic valves has two consequences.

First, fluid clearance from the tissue is less efficient, which causes the level of edema to increase.

Second, the leaking initial lymphatics allow inflammatory mediators to accumulate in the tissue, therefore enhancing interstitial and lymphatic inflammatory reactions.

PMID: 17508898 [PubMed - in process]

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Friday, May 11, 2007

Pr08 lymphatic malformations and the molecular basis of lymphangiogenesis. Options

Pr08 lymphatic malformations and the molecular basis of lymphangiogenesis.


ANZ J Surg. 2007 May

Ch'ng S, Tan ST. Wellington Regional Plastic Unit, Hutt Hospital, Wellington, New Zealand.
This paper reviews the clinical features of lymphatic malformations and the molecular basis of embryonic lymphangiogenesis.

Lymphatic malformations are classified as microcystic, macrocystic, or combined. Most commonly found in the axilla/chest and cervicofacial region, they can be localised or diffuse. The commonest complications are intralesional bleeding and infection. Other significant complications are due mainly to their mass effect on nearby anatomic structures including the airway and eyeball, and soft tissue and skeletal overgrowth including macrocheilia, macroglossia, macrotia, macromala and mandibular prognathism, resulting in functional problems in feeding, speech, occlusion, oral hygiene, and disfigurement.

The characteristic radiological finding of a LM on gadolinium-enhanced T1-weighted MRI is a low-density lesion with septation or rim enhancement. Histologically, LMs are cystic lesions that contain eosinophilic proteinaceous fluid whose walls are composed of smooth and skeletal muscle fibres, collagen and lymphocytes. Management options range from observation, comfort cares, empirical antibiotic treatment for LM cellulitis to sclerotherapy, surgical excision and Nd:YAG laser for selected cases.

Lymphangiogenesis is believed to occur in four sequential but overlapping stages: lymphatic endothelial cell competence, bias and specification, and finally lymphatic vessel terminal differentiation and maturation. Multiple genes are involved in this process including Lyve1, Nrp2, podoplanin, Prox1, VEGFR3, VEGFC and Ang2. Developmental defects during embryonic lymphangiogenesis result in lymphatic malformations.

PMID: 17490238 [PubMed - in process]

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Saturday, May 05, 2007

Molecular mechanisms of lymphatic vascular development.

Molecular mechanisms of lymphatic vascular development.

Cell Mol Life Sci. 2007 Apr 27

Keywords: Lymphangiogenesis - vascular remodeling - PROX1 - VEGFR-3 -FOXC2 - Ephs/ephrins

Lymphatic vasculature has recently emerged as a prominent area in biomedical research because of its essential role in the maintenance of normal fluid homeostasis and the involvement in pathogenesis of several human diseases, such as solid tumor metastasis, inflammation and lymphedema. Identification of lymphatic endothelial specific markers and regulators, such as VEGFR-3, VEGF-C/D, PROX1, podoplanin, LYVE-1, ephrinB2 and FOXC2, and the development of mouse models have laid a foundation for our understanding of the major steps controlling growth and remodeling of lymphatic vessels.

In this review we summarize recent advances in the field and discuss how this knowledge as well as use of model organisms, such as zebrafish and Xenopus, should allow further in depth analysis of the lymphatic vascular system.


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