S1-Leitlinie Lipödem

Die vorliegende überarbeitete Leitlinie zum Lipödem wurde unter der Federführung der Deutschen Gesellschaft für Phlebologie (DGP) erstellt und finanziert. Die Inhalte beruhen auf einer systematischen Literaturrecherche und dem Konsens von acht medizinischen Fachgesellschaften und Berufsverbänden. Die Leitlinie beinhaltet Empfehlungen zu Diagnostik und Therapie des Lipödems. Die Diagnose ist dabei auf der Basis von Anamnese und klinischem Befund zu stellen. Charakteristisch ist eine umschriebene, symmetrisch lokalisierte Vermehrung des Unterhautfettgewebes an den Extremitäten mit deutlicher Disproportion zum Stamm. Zusätzlich finden sich Ödeme, Hämatomneigung und eine gesteigerte Schmerzhaftigkeit der betroffenen Körperabschnitte. Weitere apparative Untersuchungen sind bisher besonderen Fragestellungen vorbehalten. Die Erkrankung ist chronisch progredient mit individuell unterschiedlichem und nicht vorhersehbarem Verlauf. Die Therapie besteht aus vier Säulen, die individuell kombiniert und an das aktuelle Beschwerdebild angepasst werden sollten: komplexe physikalische Entstauungstherapie (manuelle Lymphdrainage, Kompressionstherapie, Bewegungstherapie, Hautpflege), Liposuktion und plastisch-chirurgische Interventionen, Ernährung und körperliche Aktivität sowie ggf. additive Psychotherapie. Operative Maßnahmen sind insbesondere dann angezeigt, wenn trotz konsequent durchgeführter konservativer Therapie noch Beschwerden bestehen bzw. eine Progredienz des Befundes und/oder der Beschwerden auftritt. Eine begleitend zum Lipödem bestehende morbide Adipositas sollte vor einer Liposuktion therapeutisch angegangen werden.

S1 guidelines: Lipedema

The present, revised guidelines on lipedema were developed under the auspices of and funded by the German Society of Phlebology (DGP). The recommendations are based on a systematic literature search and the consensus of eight medical societies and working groups. The guidelines contain recommendations with respect to diagnosis and management of lipedema. The diagnosis is established on the basis of medical history and clinical findings. Characteristically, there is a localized, symmetrical increase in subcutaneous adipose tissue in arms and legs that is in marked disproportion to the trunk. Other findings include edema, easy bruising, and increased tenderness. Further diagnostic tests are usually reserved for special cases that require additional workup. Lipedema is a chronic, progressive disorder marked by the individual variability and unpredictability of its clinical course. Treatment consists of four therapeutic mainstays that should be combined as necessary and address current clinical symptoms: complex physical therapy (manual lymphatic drainage, compression therapy, exercise therapy, and skin care), liposuction and plastic surgery, diet, and physical activity, as well as psychotherapy if necessary. Surgical procedures are indicated if - despite thorough conservative treatment - symptoms persist, or if there is progression of clinical findings and/or symptoms. If present, morbid obesity should be therapeutically addressed prior to liposuction.

[Possibilities and limitations of molecular pathology in dermatohistology]

Malignant tumours, infections caused by microorganisms or genodermatoses are diagnosed with additional help of molecular pathology methods. Polymerase chain reaction (PCR), sequencing and in situ hybridisations play an important role. It remains to be seen if methods such as "liquid biopsies" or "single cell genomics" can be developed as routine diagnostics. High technical efforts, high costs and no possibility for resistency testing is accompanied by fast verification, high sensitivity and high specificity. Overall, molecular pathology results have to be combined with the clinical picture, histology or immunohistochemistry and culturing results to achieve a correct diagnosis for the patient.

First Association of Interleukin 12 Receptor Beta 1 Deficiency with Sjögren's Syndrome

Introduction

Interleukin 12 receptor beta 1 (IL12Rβ1) deficiency is a primary immunodeficiency resulting mainly in susceptibility to opportunistic infection by non-tuberculous, environmental mycobacteria and severe infection caused by Salmonella spp. Till now, less than 300 patients with IL12Rβ1 deficiency have been reported. Among them, only three have been described to develop autoimmunity.

Case presentation

We present the case of a 50-year-old male with IL12Rβ1 deficiency due to compound heterozygosity [c. 1623_1624delGCinsTT (pGln542Stop) and c.1791 + 2T > C (donor splice site)], who—18 months after diagnosis of disseminated BCGitis—presented with recurrent fever and sicca syndrome. No indication of an infectious origin of these symptoms could be found at that point. The diagnosis of a Sjögren’s syndrome (SS) was made on the basis of fulfilled American-European consensus classification criteria, including a positive minor salivary gland biopsy.

Conclusion

Apart from persistent antigenic stimulation, which may drive autoimmune inflammation in primary immunodeficiency, evidence on the involvement of interleukin 12 in pathogenesis of SS suggests that the same immunological mechanism may underlie both defense against infection and the maintenance of tolerance. To our knowledge, this is the first report of a case of autoimmunity in the form of SS in a patient with a primary immunodeficiency and one of the rare cases of IL12Rβ1 deficiency with manifested autoimmunity.

Characterisation of Prognosis and Invasion of Cutaneous Squamous Cell Carcinoma by Podoplanin and E-Cadherin Expression

BACKGROUND

Around 5% of all cutaneous squamous cell carcinoma (cSCC) metastasise. Metastases usually locate in regional skin and lymph nodes, suggesting collective cancer invasion. The cellular level of tumour invasion and prognostic parameters remain to be characterised.

METHODS

We performed immunohistochemical analyses of E-cadherin (marker for collective cancer invasion) and podoplanin (marker for epithelial-mesenchymal transition [EMT], single-cell invasion) expression in 102 samples of metastatic and non-metastatic cSCC and 18 corresponding skin and lymph node metastases to characterise the invasion of cSCC. Immunohistochemical results were retrospectively correlated with clinical data.

RESULTS

E-cadherin was highly expressed in metastatic and non-metastatic cSCC and skin metastases. This suggests collective cancer invasion. However, E-cadherin was downregulated in poorly differentiated cSCC and lymph node metastases, suggesting partial EMT. Podoplanin was significantly upregulated in metastatic (p = 0.002) and poorly differentiated (p = 0.003) cSCC. Overexpression of podoplanin represented a statistically independent prognostic factor for disease-free survival (p = 0.014).

CONCLUSION

Collective cancer invasion is likely in cSCC. In lymph node metastases and poorly differentiated cSCC, partial EMT is possible. Podoplanin is an independent prognostic parameter for metastasis.

Allele frequencies of BRAFV600 mutations in primary melanomas and matched metastases and their relevance for BRAF inhibitor therapy in metastatic melanoma

Background

The detection of BRAFV600 mutations in patients with metastatic melanoma is important because of the availability of BRAF inhibitor therapy. However, the clinical relevance of the frequency of BRAFV600 mutant alleles is unclear.

Patients and Methods

Allele frequencies of BRAFV600 mutations were analyzed by ultra-deep next-generation sequencing in formalin-fixed, paraffin-embedded melanoma tissue (75 primary melanomas and 88 matched metastases). In a second study, pretreatment specimens from 76 patients who received BRAF inhibitors were retrospectively analyzed, and BRAFV600 allele frequencies were correlated with therapeutic results.

Results

Thirty-five patients had concordantly BRAF-positive and 36 (48%) patients had concordantly BRAF-negative primary melanomas and matched metastases, and four patients had discordant samples with low allele frequencies (3.4–5.2%). Twenty-six of 35 patients with concordant samples had BRAFV600E mutations, three of whom had additional mutations (V600K in two patients and V600R in one) and nine patients had exclusively non-V600E mutations (V600K in eight patients and V600E -c.1799_1800TG > AA- in one patient). The frequency of mutated BRAFV600 alleles was similar in the primary melanoma and matched metastasis in 27/35 patients, but differed by >3-fold in 8/35 of samples. BRAFV600E allele frequencies in pretreatment tumor specimens were not significantly correlated with treatment outcomes in 76 patients with metastatic melanoma who were treated with BRAF inhibitors.

Conclusions

BRAFV600 mutation status and allele frequency is consistent in the majority of primary melanomas and matched metastases. A small subgroup of patients has double mutations. BRAFV600 allele frequencies are not correlated with the response to BRAF inhibitors.

[Inflammatory dermatoses]

The seven basic patterns of inflammatory dermatoses according to Ackerman can be applied to infectious dermatoses. However, it should be borne in mind that infection caused by one agent may induce differing patterns according to the stage of disease. Dermatophytosis and the arthropod reaction belong to perivascular dermatoses with spongiosis. Secondary syphilis and acrodermatitis chronica atrophicans regularly show a lichenoid infiltrate with interface dermatitis, whereas epidermal involvement is typically absent in erythema migrans, virus exanthema and bacillary angiomatosis. Lupus vulgaris, atypic mycobacteriosis, lepra, actinomycosis, cutaneous leishmaniosis and erysipelas belong to the nodular and diffuse dermatoses. In the group of vasculitides, septic vasculitis is induced by a biological agent, and the pattern of vesicular dermatitis is reflected by infections with herpes viruses, impetigo contagiosa and staphylococcal scalded-skin syndrome. Follicular dermatitis shows a pattern of furuncles and carbuncles which are mainly caused by bacteria or fungi.

Collagen-based cell migration models in vitro and in vivo

Fibrillar collagen is the most abundant extracellular matrix (ECM) constituent which maintains the structure of most interstitial tissues and organs, including skin, gut, and breast. Density and spatial alignments of the three-dimensional (3D) collagen architecture define mechanical tissue properties, i.e. stiffness and porosity, which guide or oppose cell migration and positioning in different contexts, such as morphogenesis, regeneration, immune response, and cancer progression. To reproduce interstitial cell movement in vitro with high in vivo fidelity, 3D collagen lattices are being reconstituted from extracted collagen monomers, resulting in the re-assembly of a fibrillar meshwork of defined porosity and stiffness. With a focus on tumor invasion studies, we here evaluate different in vitro collagen-based cell invasion models, employing either pepsinized or non-pepsinized collagen extracts, and compare their structure to connective tissue in vivo, including mouse dermis and mammary gland, chick chorioallantoic membrane (CAM), and human dermis. Using confocal reflection and two-photon-excited second harmonic generation (SHG) microscopy, we here show that, depending on the collagen source, in vitro models yield homogeneous fibrillar texture with a quite narrow range of pore size variation, whereas all in vivo scaffolds comprise a range from low- to high-density fibrillar networks and heterogeneous pore sizes within the same tissue. Future in-depth comparison of structure and physical properties between 3D ECM-based models in vitro and in vivo are mandatory to better understand the mechanisms and limits of interstitial cell movements in distinct tissue environments.

HGF and MET mutations in primary and secondary lymphedema

BACKGROUND

Lymphedema is the abnormal accumulation of protein-rich fluid in the interstitial space. Primary lymphedema is a rare genetic condition with both autosomal dominant and autosomal recessive modes of inheritance. Three genes, FLT4 (VEGFR3), FOXC2, and SOX18 cause varying forms of primary lymphedema. In industrialized countries, secondary lymphedema is usually associated with cancer therapy and/or trauma. Recent observations suggested that hepatocyte growth factor/high affinity hepatocyte growth factor receptor (HGF/MET) were new candidate lymphedema genes.

METHODS AND RESULTS

The coding exons and flanking regions of HGF and MET were directly sequenced in 145 lymphedema probands, 59 unrelated women with secondary lymphedema following treatment for breast cancer, 21 individual patients with lymphedema and intestinal lymphangiectasia, and at least 159 unrelated ethnic matched control individuals. Mutations leading to truncation or missense changes in evolutionarily conserved residues of HGF and MET were identified. These mutations were not polymorphic in control individuals.

CONCLUSIONS

The identification of HGF/MET mutations in primary lymphedema, lymphedema/lymphangiectasia, and breast cancer-associated secondary lymphedema suggests that the HGF/MET pathway is causal or alters susceptibility for a broad range of lymphedema phenotypes. The HGF/MET pathway provides a new target for the prevention and/or treatment of lymphedema.

Photothermolysis of blood vessels using indocyanine green and pulsed diode laser irradiation in the dorsal skinfold chamber model

BACKGROUND AND OBJECTIVE

For the treatment of vascular lesions, the use of laser light absorbed by the endogenous chromophore hemoglobin may still be improved.

MATERIALS AND METHODS

Laser treatment (lambda(em) = 805 nm; fluence rate: 106 kW/cm2; fluence: 3.2 J/cm2 (3 milliseconds)), of blood vessels directly after i.v. application of indocyanine green (ICG) (ICG-concentration: 0, 2, or 4 mg/kg body weight (b.w.)) (n = 14,117) was investigated in the skinfold chamber model. Vessel diameters (1-351 microm) were measured using intravital fluorescence microscopy up to 24 hours following irradiation. Histology was taken 1 or 24 hours after irradiation. Results were compared to a mathematical model based on the finite element method.

RESULTS

The reduction of blood vessel perfusion was proportional to ICG-concentration and pulse duration; only a 30 milliseconds pulse duration (2 or 4 mg/kg b.w. ICG-concentration) induced a loss of perfusion even of blood vessels with a diameter <30 microm. Histology revealed photocoagulation of blood vessels up to 24 hours. Results were in agreement with mathematical calculations.

CONCLUSION

ICG-mediated laser irradiation induces irreversible photocoagulation of blood vessels of all diameters in this model.

Photodynamic therapy with 5-aminolevulinic acid induces distinct microcirculatory effects following systemic or topical application

In photodynamic therapy (PDT) the photosensitiser 5-aminolaevulinic acid (ALA) can be used by systemic or topical application. Previous experiments showed that the photodynamic effects might not be mediated solely by porphyrins localized in the parenchyma, but also by porphyrins in the microvasculature. Therefore, the microcirculatory effects of PDT following systemic versus topical application of ALA have been investigated. Amelanotic melanomas were implanted in the dorsal skin fold chamber of Syrian Golden hamsters. ALA was injected i.v. for systemic PDT before irradiation, whereas ALA was applied to the chambers for topical PDT before irradiation with an incoherent lamp. FITC-labelled erythrocytes were injected to determine red blood cell velocity (RBCV) and functional vessel density (FVD). Twenty-four hours after PDT tissue was taken for histology and immunohistochemistry to reveal the degree of apoptosis and to show the accumulation of leukocytes. FVD or RBCV was not altered significantly by systemic or topical low-dose PDT (10 J cm(-2)), whereas a significant reduction of RBCV and FVD was detected after high-dose PDT (100 J cm(-2)) following systemic or topical application of ALA. Systemic PDT with 100 J cm(-2) stopped the flow only in the tumor center, whereas topical PDT with 100 J cm(-2) lead to a breakdown of RBCV in all chamber areas. Two hours and 24 h after systemic high-dose PDT, perfused microvessels and capillaries could be detected in normal tissue and tumor periphery, in contrast to topical high-dose PDT leading to a shut down of FVD 24 h after irradiation in all areas of the chamber tissue. Histological staining revealed a more pronounced intracellular oedema and swelling of cells after topical high-dose PDT than systemic high-dose PDT. These results indicate that topical high-dose PDT with ALA has a more pronounced effect on microcirculation as compared to systemic high-dose PDT in this model.

Up-regulation of the lymphatic marker podoplanin, a mucin-type transmembrane glycoprotein, in human squamous cell carcinomas and germ cell tumors

The mucin-type glycoprotein podoplanin is specifically expressed by lymphatic but not blood vascular endothelial cells in culture and in tumor-associated lymphangiogenesis, and podoplanin deficiency results in congenital lymphedema and impaired lymphatic vascular patterning. However, research into the biological importance of podoplanin has been hampered by the lack of a generally available antibody against the human protein, and its expression in normal tissues and in human malignancies has remained unclear. We generated a human podoplanin-Fc fusion protein and found that the commercially available mouse monoclonal antibody D2-40 specifically recognized human podoplanin, as assessed by enzyme-linked immunosorbent assay and Western blot analyses. We found that, in addition to lymphatic endothelium, podoplanin was also expressed by peritoneal mesothelial cells, osteocytes, glandular myoepithelial cells, ependymal cells, and by stromal reticular cells and follicular dendritic cells of lymphoid organs. These findings were confirmed in normal mouse tissues with anti-podoplanin antibody 8.1.1. Podoplanin was also strongly expressed by granulosa cells in normal ovarian follicles, and by ovarian dysgerminomas and granulosa cell tumors. Although podoplanin was primarily absent from normal human epidermis, its expression was strongly induced in 22 of 28 squamous cell carcinomas studied. These findings suggest a potential role of podoplanin in tumor progression, and they also identify the first commercially available antibody for the specific staining of a defined lymphatic marker in archival human tissue sections, thereby enabling more widespread studies of tumor lymphangiogenesis in human cancers.

In Vivo Phosphorescence Imaging ofpO2Using Planar Oxygen Sensors

OBJECTIVE

Oxygen-dependent quenching of luminescence of metal porphyrin complexes has been used to image the pO(2) distribution over tumor and normal tissue.

METHODS

An experimental setup is described using a platinum(II)-octaethyl-porphyrin immobilized in a polystyrene matrix as transparent planar sensor.

RESULTS

Sensitivity over a broad range is high at low pO(2) values (+/- 0.2 mm Hg at 0 mm Hg; +/- 1.5 mm Hg at 160 mm Hg pO(2)). Due to intrinsically referencing via lifetime encoding there was no modification of the sensor response in vivo in the dorsal skinfold chamber model with amelanotic melanoma (A-MEL-3) in awake hamsters when compared to the in vitro calibration. pO(2) measurements over normal tissue (25.8 +/- 5.1 mm Hg) and tumor tissue (9.2 +/- 5.1 mm Hg) were in excellent agreement with previous results obtained in this model using a surface multiwire electrode.

CONCLUSIONS

Using the presented method the surface pO(2) distribution can be mapped with a high temporal resolution of approximately 100 ms and a spatial resolution of at least 25 mu m. Moreover, the transparent sensor allows the simultaneous visualization of the underlying microvasculature.

Induction of cutaneous delayed-type hypersensitivity reactions in VEGF-A transgenic mice results in chronic skin inflammation associated with persistent lymphatic hyperplasia

Vascular endothelial growth factor-A (VEGF-A) expression is up-regulated in several inflammatory diseases including psoriasis, delayed-type hypersensitivity (DTH) reactions, and rheumatoid arthritis. To directly characterize the biologic function of VEGF-A in inflammation, we evaluated experimental DTH reactions induced in the ear skin of transgenic mice that overexpress VEGF-A specifically in the epidermis. VEGF-A transgenic mice underwent a significantly increased inflammatory response that persisted for more than 1 month, whereas inflammation returned to baseline levels within 7 days in wild-type mice. Inflammatory lesions in VEGF-A transgenic mice closely resembled human psoriasis and were characterized by epidermal hyperplasia, impaired epidermal differentiation, and accumulation of dermal CD4+ T-lymphocytes and epidermal CD8+ lymphocytes. Surprisingly, VEGF-A also promoted lymphatic vessel proliferation and enlargement, which might contribute to the increased inflammatory response, as lymphatic vessel enlargement was also detected in human psoriatic skin lesions. Combined systemic treatment with blocking antibodies against VEGF receptor-1 (VEGFR-1) and VEGFR-2 potently inhibited inflammation and also decreased lymphatic vessel size. Together, these findings reveal a central role of VEGF-A in promoting lymphatic enlargement, vascular hyperpermeability, and leukocyte recruitment, thereby leading to persistent chronic inflammation. They also indicate that inhibition of VEGF-A bioactivity might be a new approach to anti-inflammatory therapy.

The lymphatic system in the dorsal skinfold chamber of the Syrian golden hamster in vivo

The lymphatic network contributes to maintaining tissue homeostasis and immunological function by transporting fluid, plasma protein and cells from peripheral tissue via the lymph nodes into the blood vascular system. In contrast to the blood circulatory system, little is known about the lymphatic system. In particular, suitable animal models are lacking. Therefore, the dorsal skinfold chamber model was used to investigate the existence of a lymphatic system. To analyze the lymphatic network Syrian golden hamsters (n=12) fitted with titanium chambers were used. FITC-dextran of different concentrations (5% or 25%) and different molecular weights (4, 40 or 150 kDa) was used to contrast lymphatic vessels and measure initial lymph flow velocity. Intravital fluorescence microscopy enabled the quantification of diameter, velocity and branching order. Histology and electron microscopy supported the in vivo findings. Immediately after intradermal injection of FITC-dextran the lymphatics including valves were visible. The diameters of the lymphatic vessels (n=189) ranged from 133+/-5.4 microm (branching order 1) to 26+/-4.0 microm (branching order 5). Using different molecular weights of FITC-dextran, no significant differences in velocity were measured (327+/-157 microm/s with 4 kDa, 391+/-126 microm/s with 40 kDa, and 378+/-175 microm/s with 150 kDa). Blood and lymphatic vessels could not be differentiated clearly by H&E staining. However, endothelial cells of vessels with an irregularly shaped lumen containing no erythrocytes in cross section showed a weaker signal for CD31 staining as compared to endothelial cells of vessels containing erythrocytes. Moreover, transmission electron microscopy identified the dye-containing vessels as lymphatics after intradermal injection of Berlin Blue. In conclusion, a lymphatic network was characterized in the dorsal skinfold chamber model of the Syrian golden hamster. Thus, this well-established animal model for intravital microscopy provides the opportunity to elucidate the physiological and pathological function of the lymphatic vascular system.

T1alpha/podoplanin deficiency disrupts normal lymphatic vasculature formation and causes lymphedema

Within the vascular system, the mucin-type transmembrane glycoprotein T1alpha/podoplanin is predominantly expressed by lymphatic endothelium, and recent studies have shown that it is regulated by the lymphatic-specific homeobox gene Prox1. In this study, we examined the role of T1alpha/podoplanin in vascular development and the effects of gene disruption in mice. T1alpha/podoplanin is first expressed at around E11.0 in Prox1-positive lymphatic progenitor cells, with predominant localization in the luminal plasma membrane of lymphatic endothelial cells during later development. T1alpha/podoplanin(-/-) mice die at birth due to respiratory failure and have defects in lymphatic, but not blood vessel pattern formation. These defects are associated with diminished lymphatic transport, congenital lymphedema and dilation of lymphatic vessels. T1alpha/podoplanin is also expressed in the basal epidermis of newborn wild-type mice, but gene disruption did not alter epidermal differentiation. Studies in cultured endothelial cells indicate that T1alpha/podoplanin promotes cell adhesion, migration and tube formation, whereas small interfering RNA-mediated inhibition of T1alpha/podoplanin expression decreased lymphatic endothelial cell adhesion. These data identify T1alpha/podoplanin as a novel critical player that regulates different key aspects of lymphatic vasculature formation.

Effects of light fractionation and different fluence rates on photodynamic therapy with 5-aminolaevulinic acid in vivo

To improve efficacy of photodynamic therapy (PDT) with intravenously administered 5-aminolaevulinic acid (ALA) fractionating the light dose or reducing the light intensity may be a possibility. Therefore, Syrian Golden hamsters were fitted with dorsal skinfold chambers containing an amelanotic melanoma (n=26). PDT was performed (100 mW cm(-2), 100 J cm(-2), continuously or fractionated, and 25 mW cm(-2), 100 J cm(-2); continuously or fractionated) using an incoherent light source following i.v. application of ALA. Following fractionated irradiation, the light was paused after 20 J cm(-2) for 15 min. Prior to and up to 24 h after PDT tissue, pO(2) was measured using luminescence lifetime imaging. The efficacy was evaluated by measuring the tumour volume of amelanotic melanoma cells grown subcutaneously in the back of Syrian Golden hamsters (n=36). Only high-dose PDT resulted in a significant decrease of pO(2). Irrespective of the mode of irradiation only high-dose PDT induced complete remission of all tumours (13 out of 13). It could be shown that low-dose PDT failed to induce a significant decrease of pO(2). No significant effect of fractionated irradiation was shown regarding the therapeutic efficacy 28 days after PDT. Thus performing a fractionated PDT with ALA or reducing the light intensity seems not to be successful in clinical PDT according to the present data.

Identification of vascular lineage-specific genes by transcriptional profiling of isolated blood vascular and lymphatic endothelial cells

In mammals, the lymphatic vascular system develops by budding of lymphatic progenitor endothelial cells from embryonic veins to form a distinct network of draining vessels with important functions in the immune response and in cancer metastasis. However, the lineage-specific molecular characteristics of blood vascular versus lymphatic endothelium have remained poorly defined. We isolated lymphatic endothelial cells (LECs) and blood vascular endothelial cells (BVECs) by immunomagnetic isolation directly from human skin. Cultured LECs but not BVECs expressed the lymphatic markers Prox1 and LYVE-1 and formed LYVE-1-positive vascular tubes after implantation in vivo. Transcriptional profiling studies revealed increased expression of several extracellular matrix and adhesion molecules in BVECs, including versican, collagens, laminin, and N-cadherin, and of the growth factor receptors endoglin and vascular endothelial growth factor receptor-1/Flt-1. Differential immunostains of human skin confirmed the blood vessel-specific expression of these genes. During embryonic development, endoglin expression was gradually down-regulated on lymphatic endothelium whereas vascular endothelial growth factor receptor-1 was absent from lymphatics. We also identified several genes with specific expression in LECs. These results demonstrate that some lineage-specific genes are only expressed during distinct developmental stages and they identify new molecular markers for blood vascular and lymphatic endothelium with important implications for future studies of vascular development and function.

Apoptosis and leucocyte-endothelium interactions contribute to the delayed effects of cryotherapy on tumours in vivo

In dermatology, cryotherapy is commonly used to treat benign and malignant skin lesions. However, studies investigating the time-course of the direct and delayed effects on the microvasculature and subsequent tissue destruction are lacking. Amelanotic melanomas (A-Mel-3) were implanted into the dorsal skinfold chamber of Syrian Golden hamsters (n=51). Tumour and normal tissue were frozen to -20 masculine C (cooling rate 150 masculine C/min). Intravital fluorescence microscopy was performed to assess microvascular changes and leucocyte-endothelium interactions up to 24 h. The relative degrees of necrosis and apoptosis and the accumulation of leucocytes were investigated by histology and immunohistochemistry. Apoptosis was quantified using the TUNEL assay in combination with computer-assisted image analysis. After cryotherapy, red blood cell velocity (RBCV) decreased in postcapillary venules and tumour vessels, whereas functional vessel density (FVD) was significantly reduced in tumour vessels as compared with postcapillary venules. Leucocyte-endothelium interaction increased first in normal and tumour tissue, and then after 24 h leucocytes accumulated in normal tissue close to the tumour margin. Necrosis was induced in the cryolesions directly after freezing and remained constant over the entire observation period. In contrast, apoptosis increased in the periphery of the tumour tissue up to 24 h following cryotherapy. In conclusion, tissue destruction by cryotherapy is not only induced by direct necrosis and microvascular stasis, but also by the inflammatory infiltrate and subsequent apoptosis. This could be an important finding regarding the generation of an immune response.

Prox1 is a master control gene in the program specifying lymphatic endothelial cell fate

Early during development, one of the first indications that lymphangiogenesis has begun is the polarized expression of the homeobox gene Prox1 in a subpopulation of venous endothelial cells. It has been shown previously that Prox1 expression in the cardinal vein promotes and maintains the budding of endothelial cells that will form the lymphatic vascular system. Prox1-deficient mice are devoid of lymphatic vasculature, and in these animals endothelial cells fail to acquire the lymphatic phenotype; instead, they remain as blood vascular endothelium. To investigate whether Prox1 is sufficient to induce a lymphatic fate in blood vascular endothelium, Prox1 cDNA was ectopically expressed by adenoviral gene transfer in primary human blood vascular endothelial cells and by transient plasmid cDNA transfection in immortalized microvascular endothelial cells. Transcriptional profiling combined with quantitative real-time reverse transcription-polymerase chain reaction and Western blotting analyses revealed that Prox1 expression up-regulated the lymphatic endothelial cell markers podoplanin and vascular endothelial growth factor receptor-3. Conversely, genes such as laminin, vascular endothelial growth factor-C, neuropilin-1, and intercellular adhesion molecule-1, whose expression has been associated with the blood vascular endothelial cell phenotype, were down-regulated. These results were confirmed by the use of specific antibodies against some of these markers in sections of embryonic and adult tissues. These findings validate our previous proposal that Prox1 is a key player in the molecular pathway leading to the formation of lymphatic vasculature and identify Prox1 as a master switch in the program specifying lymphatic endothelial cell fate. That a single gene product was sufficient to re-program the blood vascular endothelium toward a lymphatic phenotype corroborates the close relationship between these two vascular systems and also suggests that during evolution, the lymphatic vasculature originated from the blood vasculature by the additional expression of only a few gene products such as Prox1.

[Trichorhinophalangeal syndrome. Case report and biophysical study of hair shaft parameters]

In 1956 Klingmüller first described the trichorhinophalangeal syndrome (TRPS), which was named by Giedion ten years later. The syndrome includes a combination of typical hair, facial and bone abnormalities with variable expression allowing the further distinction of three subtypes. In a 37-year old patient with TRPS type I who reportedly had reduced hair growth length, clinically fine and brittle hair were found. Scanning electron microscopy revealed widely spaced cuticular scales. Quantitative measurement of the biomechanical properties of the hair showed a significant increase in the viscous parameter. This could be a result of decreased disulfide bridges and increased halogen bonds in the keratin matrix of the hair. In dermatological practice patients with TRPS often present because of hair abnormalities. Because of premature arthrosis due to skeletal abnormalities, occupational counseling is advised.Congenital heart problems, kidney abnormalities and endocrinological problems are rare, but should be sought in the symptomatic individual. Apart from mild hair care and avoidance of additional physical or chemical injuries due to hair cosmetic procedures,there is no treatment for the hair defects.