Microangiopathy of cutaneous blood and lymphatic capillaries in chronic venous insufficiency (CVI).

The severity of microangiopathy in patients with chronic venous insufficiency (CVI) determines the extent of the trophic disturbances of the skin. Resulting from valvular incompetence of deep and/or perforating veins and the accompanying venous outflow obstruction caused by deep venous thrombosis (DVT), the increased ambulatory venous pressure heads are transmitted retrograde into the microvasculature of the skin at the ankle region. In the present study, we have assessed the changes in the cutaneous microvasculature by dynamic fluorescence video microscopy, fluorescence microlymphography, and transcutaneous oxygen tension (tcPO2) measurements. In mild forms of CVI, capillary density, morphologic characteristics, and tcPO2 are still normal. Fluorescent light intensity is, however, significantly increased, indicating an increased transcapillary diffusion of sodium fluorescein (NaF) as a marker for enhanced leakage of the capillaries in the early stage of the disease. The pericapillary halo diameters are significantly enlarged, compared to controls (p < 0.01). In the severe stages of CVI and in patients with venous ulcers, capillary thromboses, probably caused by endothelium-blood cell interactions, may lead to a reduced capillary density. In order to enlarge the exchange surface area, the remaining skin capillaries become tortuous (capillary tufts). Parallel to the reduced capillary number, tcPO2 decreases and can be extremely low at the ulcer rim or at white atrophy spots. Fibrin cuffs are not a specific finding for venous ulceration and do not significantly impair oxygen diffusion. Fluorescence microlymphography permits visualization of the lymphatic capillaries of the superficial skin. In severe stages of CVI, the lymphatic capillary network at the medial ankle area is destroyed, and the remaining lymphatic capillary fragments have an increased permeability to FITC-dextran with a molecular weight of 150,000. These findings demonstrate a special lymphatic microangiopathy in CVI, suggesting an additional lymphatic component in the edema formation

Ross procedure: is the root replacement technique superior to the sub-coronary implantation technique? Long-term results.

There is controversy over the use of the Ross procedure with regard to the sub-coronary and root replacement technique and its long-term durability. A systematic review of the literature may provide insight into the outcomes of these two surgical subvariants. A systematic review of reports between 1967 and February 2013 on sub-coronary and root replacement Ross procedures was undertaken. Twenty-four articles were included and divided into (i) sub-coronary technique and (ii) root replacement technique. The 10-year survival rate for a mixed-patient population in the sub-coronary procedure was 87.3% with a 95% confidence interval (CI) of 79.7-93.4 and 89.1% (95% CI, 85.3-92.1) in the root replacement technique category. For adults, it was 94 vs 95.3% (CI, 88.9-98.1) and in the paediatric series it was 90 vs 92.7% (CI, 86.9-96.0), respectively. Freedom from reoperation at 10 years was, in the mixed population, 83.3% (95% CI, 69.9-93.4) and 93.3% (95% CI, 89.4-95.9) for sub-coronary versus root replacement technique, respectively. In adults, it was 98 vs 91.2% (95% CI, 82.4-295.8), and in the paediatric series 93.3 vs 92.0% (95% CI, 86.1-96.5) for sub-coronary versus root replacement technique, respectively. The Ross procedure arguably has satisfactory results over 5 and 10 years for both adults and children. The results do not support the advantages of the sub-coronary technique over the root replacement technique. Root replacement was of benefit to patients undergoing reoperations on neoaorta and for long-term survival in mixed series

A Novel Porcine In Vitro Model of the Blood-Cerebrospinal Fluid Barrier with Strong Barrier Function

Epithelial cells of the plexus choroideus form the structural basis of the blood-cerebrospinal fluid barrier (BCSFB). In vitro models of the BCSFB presenting characteristics of a functional barrier are of significant scientific interest as tools for examination of BCSFB function. Due to a lack of suitable cell lines as in vitro models, primary porcine plexus epithelial cells were subjected to a series of selective cultivation steps until a stable continuous subcultivatable epithelial cell line (PCP-R) was established. PCP-R cells grow in a regular polygonal pattern with a doubling time of 28–36 h. At a cell number of 1.5×105 in a 24-well plate confluence is reached in 56–72 h. Cells are cytokeratin positive and chromosomal analysis revealed 56 chromosomes at peak (84th subculture). Employing reverse transcription PCR mRNA expression of several transporters and components of cell junctions could be detected. The latter includes tight junction components like Claudin-1 and -3, ZO-1, and Occludin, and the adherens junction protein E-cadherin. Cellular localization studies of ZO-1, Occludin and Claudin-1 by immunofluorescence and morphological analysis by electron microscopy demonstrated formation of a dense tight junction structure. Importantly, when grown on cell culture inserts PCP-R developed typical characteristics of a functional BCSFB including high transepithelial electrical resistance above 600 Ω×cm2 as well as low permeability for macromolecules. In summary, our data suggest the PCP-R cell line as a suitable in vitro model of the porcine BCSFB

Polar Invasion and Translocation of Neisseria meningitidis and Streptococcus suis in a Novel Human Model of the Blood-Cerebrospinal Fluid Barrier

Acute bacterial meningitis is a life-threatening disease in humans. Discussed as entry sites for pathogens into the brain are the blood-brain and the blood-cerebrospinal fluid barrier (BCSFB). Although human brain microvascular endothelial cells (HBMEC) constitute a well established human in vitro model for the blood-brain barrier, until now no reliable human system presenting the BCSFB has been developed. Here, we describe for the first time a functional human BCSFB model based on human choroid plexus papilloma cells (HIBCPP), which display typical hallmarks of a BCSFB as the expression of junctional proteins and formation of tight junctions, a high electrical resistance and minimal levels of macromolecular flux when grown on transwell filters. Importantly, when challenged with the zoonotic pathogen Streptococcus suis or the human pathogenic bacterium Neisseria meningitidis the HIBCPP show polar bacterial invasion only from the physiologically relevant basolateral side. Meningococcal invasion is attenuated by the presence of a capsule and translocated N. meningitidis form microcolonies on the apical side of HIBCPP opposite of sites of entry. As a functionally relevant human model of the BCSFB the HIBCPP offer a wide range of options for analysis of disease-related mechanisms at the choroid plexus epithelium, especially involving human pathogens