Utilizing lymphatic cell markers to visualize human lymphatic abnormalities.

In vivo visualization of the human lymphatic system is limited by the mode of delivery of tracing agents, depth of field and size of the area examined, and specificity of the cell markers used to distinguish lymphatic endothelium from the blood vessels and the surrounding tissues. These limitations are particularly problematic when imaging human lymphatic abnormalities. First, limited understanding of the lymphatic disease aetiology exists with respect to genetic causes and phenotypic presentations.

Prolonged antibiotic treatment for infected low flow vascular malformations.

Background: Infection in low flow malformations is difficult to diagnose and treat. Initial presentation can be followed by cycles of recurrent infection lasting several years. The optimal duration of antibiotic therapy to prevent recurrence of infection has not been established.

Wound management of ulcerated haemangioma of infancy - an audit.

Haemangioma of infancy, a benign tumour of blood vessels, is the most common tumour of infancy. Ulceration, the most common complication, presents a unique wound care challenge. A retrospective audit of medical records of children with haemangioma of infancy who presented to the Royal Children's Hospital, Melbourne, Australia, between January 2000 and December 2014 was undertaken with an aim to examine wound management of ulcerated haemangioma of infancy.

Consensus statement for the treatment of infantile haemangiomas with propranolol.

Although most infantile haemangiomas do not require treatment due to a natural history of spontaneous involution, some require early intervention. The Australasian Vascular Anomalies Network and the Australasian Paediatric Dermatology Network have developed a consensus statement for the treatment of infantile haemangiomas with oral propranolol. Infants with haemangiomas that are life threatening, at risk of ulceration, or at risk of causing a significant functional impairment, psychological impact or physical deformity should be treated early with oral propranolol.

GAPTrap: A Simple Expression System for Pluripotent Stem Cells and Their Derivatives.

The ability to reliably express fluorescent reporters or other genes of interest is important for using human pluripotent stem cells (hPSCs) as a platform for investigating cell fates and gene function. We describe a simple expression system, designated GAPTrap (GT), in which reporter genes, including GFP, mCherry, mTagBFP2, luc2, Gluc, and lacZ are inserted into the GAPDH locus in hPSCs. Independent clones harboring variations of the GT vectors expressed remarkably consistent levels of the reporter gene.

Blue Rubber Bleb Nevus (BRBN) Syndrome Is Caused by Somatic TEK (TIE2) Mutations.

Blue rubber bleb nevus syndrome (Bean syndrome) is a rare, severe disorder of unknown cause, characterized by numerous cutaneous and internal venous malformations; gastrointestinal lesions are pathognomonic. We discovered somatic mutations in TEK, the gene encoding TIE2, in 15 of 17 individuals with blue rubber bleb nevus syndrome. Somatic mutations were also identified in five of six individuals with sporadically occurring multifocal venous malformations.

Isolation, Identification, and Culture of Human Lymphatic Endothelial Cells.

A protocol describing the isolation of foreskin lymphatic endothelial cells (LECs) and lymphatic malformation lymphatic endothelial cells (LM LECs) is presented herein. To isolate LECs and LM LECs, tissues are mechanically disrupted to make a single-cell suspension, which is then enzymatically digested in dispase and collagenase type II. LECs and LM LECs, in the resulting single-cell suspension, are then sequentially labeled with antibodies recognizing fibroblast and endothelial cell surface antigens CD34 and CD31 and separated from the remaining components in the cell suspension by capture with magnetic beads.

Applying Advanced Imaging Techniques to a Murine Model of Orthotopic Osteosarcoma.

Introduction: Reliable animal models are required to evaluate novel treatments for osteosarcoma. In this study, the aim was to implement advanced imaging techniques in a murine model of orthotopic osteosarcoma to improve disease modeling and the assessment of primary and metastatic disease.

Materials And Methods: Intra-tibial injection of luciferase-tagged OPGR80 murine osteosarcoma cells was performed in Balb/c nude mice.

Isolation of human lymphatic endothelial cells by multi-parameter fluorescence-activated cell sorting.

Lymphatic system disorders such as primary lymphedema, lymphatic malformations and lymphatic tumors are rare conditions that cause significant morbidity but little is known about their biology. Isolating highly pure human lymphatic endothelial cells (LECs) from diseased and healthy tissue would facilitate studies of the lymphatic endothelium at genetic, molecular and cellular levels. It is anticipated that these investigations may reveal targets for new therapies that may change the clinical management of these conditions.

Infantile haemangiomas that failed treatment with propranolol: clinical and histopathological features.

Aim: To describe the clinical and histopathological characteristics of infantile haemangiomas that failed treatment with oral propranolol .

Design: This study is a case series from the vascular birthmarks clinic at Royal Children's Hospital, Melbourne.

Patients: The patients for this study were infants who commenced treatment with oral propranolol before 6 months of age and who were treated for at least 4 months without a satisfactory result.

A low-cost, small volume circuit for autologous blood normothermic perfusion of rabbit organs.

We have designed a laboratory extracorporeal normothermic blood perfusion system for whole organs (e.g., kidney) that achieves pulsatile flow, low levels of hemolysis, and a blood priming volume of 60 mL or less.

Isolation of human lymphatic malformation endothelial cells, their in vitro characterization and in vivo survival in a mouse xenograft model.

Human lymphatic vascular malformations (LMs), also known as cystic hygromas or lymphangioma, consist of multiple lymphatic endothelial cell-lined lymph-containing cysts. No animal model of this disease exists. To develop a mouse xenograft model of human LM, CD34(Neg)CD31(Pos) LM lymphatic endothelial cells (LM-LEC) were isolated from surgical specimens and compared to foreskin CD34(Neg)CD31(Pos) lymphatic endothelial cells (LECs).

Extracellular matrix of secondary lymphoid organs impacts on B-cell fate and survival.

We describe a unique extracellular matrix (ECM) niche in the spleen, the marginal zone (MZ), characterized by the basement membrane glycoproteins, laminin α5 and agrin, that promotes formation of a specialized population of MZ B lymphocytes that respond rapidly to blood-borne antigens. Mice with reduced laminin α5 expression show reduced MZ B cells and increased numbers of newly formed (NF) transitional B cells that migrate from the bone marrow, without changes in other immune or stromal cell compartments. Transient integrin α6β1-mediated interaction of NF B cells with laminin α5 in the MZ supports the MZ B-cell population, their long-term survival, and antibody response.

Enhanced liver progenitor cell survival and differentiation in vivo by spheroid implantation in a vascularized tissue engineering chamber.

Liver tissue engineering is hampered by poor implanted cell survival due to inadequate vascularization and cell-cell/cell-matrix interactions. Here, we use liver progenitor cell (LPC) spheroids to enhance cell-cell/cell-matrix interactions, with implantation into an angiogenic in vivo mouse chamber. Spheroids were generated in vitro in methylcellulose medium.

Hypoxic conditioning enhances the angiogenic paracrine activity of human adipose-derived stem cells.

Human adipose-derived stem cells (ASCs) secrete cytokines and growth factors that can be harnessed in a paracrine fashion for promotion of angiogenesis, cell survival, and activation of endogenous stem cells. We recently showed that hypoxia is a powerful stimulus for an angiogenic activity from ASCs in vitro and here we investigate the biological significance of this paracrine activity in an in vivo angiogenesis model. A single in vitro exposure of ASCs to severe hypoxia (<0.

Ischemic preconditioning promotes intrinsic vascularization and enhances survival of implanted cells in an in vivo tissue engineering model.

Ischemic preconditioning (IPC) is a potent and effective means of protecting cells against ischemic injury. The protection has been demonstrated to involve release of paracrine factors that promote cell survival and angiogenesis, factors important for successful tissue engineering. The aim of the present study was to determine whether IPC of a vascular bed in vivo is an effective strategy to prepare it for tissue engineering with implanted cells.

Hypoxia and hypoxia signaling in tissue repair and fibrosis.

Following injury, vascular damage results in the loss of perfusion and consequent low oxygen tension (hypoxia) which may be exacerbated by a rapid influx of inflammatory and mesenchymal cells with high metabolic demands for oxygen. Changes in systemic and cellular oxygen concentrations induce tightly regulated response pathways that attempt to restore oxygen supply to cells and modulate cell function in hypoxic conditions. Most of these responses occur through the induction of the transcription factor hypoxia-inducible factor-1 (HIF-1) which regulates many processes needed for tissue repair during ischemia in the damaged tissue.

Comparative analysis of paracrine factor expression in human adult mesenchymal stem cells derived from bone marrow, adipose, and dermal tissue.

Human adult mesenchymal stem cells (MSCs) support the engineering of functional tissue constructs by secreting angiogenic and cytoprotective factors, which act in a paracrine fashion to influence cell survival and vascularization. MSCs have been isolated from many different tissue sources, but little is known about how paracrine factor secretion varies between different MSC populations. We evaluated paracrine factor expression patterns in MSCs isolated from adipose tissue (ASCs), bone marrow (BMSCs), and dermal tissues [dermal sheath cells (DSCs) and dermal papilla cells (DPCs)].

Visualisation and stereological assessment of blood and lymphatic vessels.

The physiological processes involved in tissue development and regeneration also include the parallel formation of blood and lymphatic vessel circulations which involves their growth, maturation and remodelling. Both vascular systems are also frequently involved in the development and progression of pathological conditions in tissues and organs. The blood vascular system circulates oxygenated blood and nutrients at appropriate physiological levels for tissue survival, and efficiently removes all waste products including carbon dioxide.

Strategies in cardiac tissue engineering.

In heart failure, post-myocardial infarction and some congenital cardiac anomalies, organ transplantation is the only effective cure. Shortage of organ donors and complications of orthotopic heart transplant remain major challenges to the modern field of transplantation. Tissue engineering using cell-based strategies presents itself as a new way of generating functional myocardium.

Disparate companions: tissue engineering meets cancer research.

Recreating an environment that supports and promotes fundamental homeostatic mechanisms is a significant challenge in tissue engineering. Optimizing cell survival, proliferation, differentiation, apoptosis and angiogenesis, and providing suitable stromal support and signalling cues are keys to successfully generating clinically useful tissues. Interestingly, those components are often subverted in the cancer setting, where aberrant angiogenesis, cellular proliferation, cell signalling and resistance to apoptosis drive malignant growth.

An endogenously deposited fibrin scaffold determines construct size in the surgically created arteriovenous loop chamber model of tissue engineering.

Background: An arteriovenous loop (AVL) enclosed in a polycarbonate chamber in vivo, produces a fibrin exudate which acts as a provisional matrix for the development of a tissue engineered microcirculatory network.

Objectives: By administering enoxaparin sodium - an inhibitor of fibrin polymerization, the significance of fibrin scaffold formation on AVL construct size (including the AVL, fibrin scaffold, and new tissue growth into the fibrin), growth, and vascularization were assessed and compared to controls.

Methods: In Sprague Dawley rats, an AVL was created on femoral vessels and inserted into a polycarbonate chamber in the groin in 3 control groups (Series I) and 3 experimental groups (Series II).

Engineering the microcirculation.

The ultimate survival of tissue-engineered constructs in vivo depends on the provision of an adequate blood supply to the engineered tissue and the capacity of the engineered microcirculation to connect with the existing recipient circulation. Techniques for the vascularization of tissue-engineered constructs can be broadly grouped into in vitro and in vivo approaches that rely on the presence of a pro-angiogenic microenvironment. Significant advances have been made in resolving the problem of microcirculatory network formation for large 3-dimensional constructs; however, issues concerning construct-host vessel connection, expansion of vascular volume accompanying growing tissue, and prevention of premature or excessive vascular regression remain to be resolved.

Bisphosphonate-associated jawbone osteonecrosis: a correlation between imaging techniques and histopathology.

Objectives: Recently, jawbone osteonecrosis has been reported as a potential adverse effect of bisphosphonates administration. This paper considers and highlights histopathologic and radiologic features of this condition.

Study Design: Eleven patients, owing to unresponsiveness to conservative treatment and uncontrollable pain, underwent surgical resection of diseased jawbone after extensive hyperbaric oxygen therapy.