Adhesion molecules of detrusor muscle cells are influenced by a hypercholesterolemic diet or bladder outlet obstruction in a wistar rat model

Abstract Background Cell adhesion molecules (CAMs) are essential for maintaining tissue integrity by regulating intercellular and cell to extracellular matrix interactions. Cadherins and catenins are CAMs that are located on the cell membrane and are important for adherens junction (AJ) function. This study aims to verify if hypercholesterolemic diet (HCD) or bladder outlet obstruction (BOO) promotes structural bladder wall modifications specific to alterations in the expression of cadherins and catenins in detrusor muscle cells. Methods Forty-five 4-week-old female Wistar rats were divided into the following three groups: group 1 was a control group that was fed a normal diet (ND); group 2 was the BOO model and was fed a ND; and group 3 was a control group that was fed a HCD (1.25% cholesterol). Initially, serum cholesterol, LDL cholesterol and body weight were determined. Four weeks later, groups 1 and 3 underwent a sham operation; whereas group 2 underwent a partial BOO procedure that included a suture tied around the urethra. Six weeks later, all rats had their bladders removed, and previous exams were repeated. The expression levels of N-, P-, and E-cadherin, cadherin-11 and alpha-, beta- and gamma-catenins were evaluated by immunohistochemistry with a semiquantitative analysis. Results Wistar rats fed a HCD (group 3) exhibited a significant increase in LDL cholesterol levels (p=0.041) and body weight (p=0.017) when compared to both groups that were fed a normal diet in a ten-week period. We found higher β- and γ-catenin expression in groups 2 and 3 when compared to group 1 (p = 0.042 and p = 0.044, respectively). We also observed Cadherin-11 overexpression in group 3 when compared to groups 1 and 2 (p = 0.002). Conclusions A HCD in Wistar rats promoted, in addition to higher body weight gain and increased serum LDL cholesterol levels, overexpression of β- and γ-catenin in the detrusor muscle cells. Similar finding was observed in the BOO group. Higher Cadherin-11 expression was observed only in the HCD-treated rats. These findings may be associated with bladder dysfunctions that occur under such situations.

Lê–Greuel type formula for the Euler obstruction and applications

The Euler obstruction of a function f can be viewed as a generalization of the Milnor number for functions defined on singular spaces. In this work, using the Euler obstruction of a function, we establish several Lê–Greuel type formulas for germs f:(X,0)→(C,0) and g:(X,0)→(C,0). We give applications when g is a generic linear form and when f and g have isolated singularities.

Deriving Deligne-Mumford stacks with perfect obstruction theories

Intersection theory on moduli spaces has lead to immense progress in certain areas of enumerative geometry. For some important areas, most notably counting stable maps and counting stable sheaves, it is important to work with a virtual fundamental class instead of the usual fundamental class of the moduli space. The crucial prerequisite for the existence of such a class is a two-term complex controlling deformations of the moduli space. Kontsevich conjectured in 1994 that there should exist derived version of spaces with this specific property. Another hint at the existence of these spaces comes from derived algebraic geometry. It is expected that for every pair of a space and a complex controlling deformations of the space their exists, under some additional hypothesis, a derived version of the space having the chosen complex as cotangent complex. In this thesis one version of these additional hypothesis is identified. We then show that every space admitting a two-term complex controlling deformations satisfies these hypothesis, and we finally construct the derived spaces.

Uptake of gold nanoparticles in microvascular endothelial cells

The physicochemical properties of nanoparticles make them suitable for biomedical applications. Due to their ‘straight-forward’ synthesis, their known biocompatibility, their strong optical properties, their ability for targeted drug delivery and their uptake potential into cells gold nanoparticles are highly interesting for biomedical applications. In particular, the therapy of brain diseases (neurodegenerative diseases, ischemic stroke) is a challenge for contemporary medicine and gold nanoparticles are currently being studied in the hope of improving drug delivery to the brain.rnIn this thesis three major conclusions from the generated data are emphasized.rn1. After improvement of the isolation protocol and culture conditions, the formation of a monolayer of porcine brain endothelial cells on transwell filters lead to a reproducible and tight in vitro monoculture which exhibited in vivo blood brain barrier (BBB) characteristics. The transport of nanoparticles across the barrier was studied using this model.rn2. Although gold nanoparticles are known to be relatively bioinert, contaminants of the nanoparticle synthesis (i.e. CTAB or sodium citrate) increased the cytotoxicity of gold nanoparticles, as shown by various publications. The results presented in this thesis demonstrate that contaminants of the nanoparticle synthesis such as sodium citrate increased the cytotoxicity of the gold nanoparticles in endothelial cells but in a more dramatic manner in epithelial cells. Considering the increased uptake of these particles by epithelial cells compared to endothelial cells it was demonstrated that the observed decrease of cell viability appeared to be related to the amount of internalized gold nanoparticles in combination with the presence of the contaminant.rn3. Systematically synthesized gold nanoparticles of different sizes with a variety of surface modifications (different chemical groups and net charges) were investigated for their uptake behaviour and functional impairment of endothelial cells, one of the major cell types making up the BBB. The targeting of these different nanoparticles to endothelial cells from different parts of the body was investigated in a comparative study of human microvascular dermal and cerebral endothelial cells. In these experiments it was demonstrated that different properties of the nanoparticles resulted in a variety of uptake patterns into cells. Positively charged gold nanoparticles were internalized in high amounts, while PEGylated nanoparticles were not taken up by both cell types. Differences in the uptake behavior were also demonstrated for neutrally charged particles of different sizes, coated with hydroxypropylamine or glucosamine. Endothelial cells of the brain specifically internalized 35nm neutrally charged hydroxypropylamine-coated gold nanoparticles in larger amounts compared to dermal microvascular endothelial cells, indicating a "targeting" for brain endothelial cells. Co-localization studies with flotillin-1 and flotillin-2 showed that the gold nanoparticles were internalized by endocytotic pathways. Furthermore, these nanoparticles exhibited transcytosis across the endothelial cell barrier in an in vitro BBB model generated with primary porcine brain endothelial cells (1.). In conclusion, gold nanoparticles with different sizes and surface characteristics showed different uptake patterns in dermal and cerebral endothelial cells. In addition, gold nanoparticles with a specific size and defined surface modification were able to cross the blood-brain barrier in a porcine in vitro model and may thus be useful for controlled delivery of drugs to the brain.

An uncommon cause of coronary artery ostial obstruction: papillary fibroelastoma

Cardiac papillary fibroelastoma is a benign tumor that mainly affects cardiac valves. The tumor has the potential to cause angina and myocardial infarction due to embolization of tumor fragments. We describe a rare case of right coronary artery ostial obstruction by a 12 x 19 mm sized papillary fibroelastoma located in the sinus of Valsalva. The report underlies the importance of echocardiography in diagnosis and intraoperative treatment of this type of cardiac mass.

Comparison of immortalized bEnd5 and primary mouse brain microvascular endothelial cells as in vitro blood-brain barrier models for the study of T cell extravasation

Important insights into the molecular mechanism of T cell extravasation across the blood-brain barrier (BBB) have already been obtained using immortalized mouse brain endothelioma cell lines (bEnd). However, compared with bEnd, primary brain endothelial cells have been shown to establish better barrier characteristics, including complex tight junctions and low permeability. In this study, we asked whether bEnd5 and primary mouse brain microvascular endothelial cells (pMBMECs) were equally suited as in vitro models with which to study the cellular and molecular mechanisms of T cell extravasation across the BBB. We found that both in vitro BBB models equally supported both T cell adhesion under static and physiologic flow conditions, and T cell crawling on the endothelial surface against the direction of flow. In contrast, distances of T cell crawling on pMBMECs were strikingly longer than on bEnd5, whereas diapedesis of T cells across pMBMECs was dramatically reduced compared with bEnd5. Thus, both in vitro BBB models are suited to study T cell adhesion. However, because pMBMECs better reflect endothelial BBB specialization in vivo, we propose that more reliable information about the cellular and molecular mechanisms of T cell diapedesis across the BBB can be attained using pMBMECs.

Intussusceptive microvascular growth in tumors

Intussusception is an alternative to the sprouting mode of angiogenesis. The advantage of this mechanism of vascular growth is that blood vessels are generated more rapidly and the capillaries thereby formed are less leaky. This review article summarizes our current knowledge concerning the role played by intussusceptive microvascular growth in tumor growth. Interestingly, an angiogenic switch from sprouting to intussusceptive angiogenesis occurs after treatment with angiogenesis inhibitors and may be considered as a tumor-protective adaptative response.

Prognostic value of microvascular invasion in predicting the cancer specific survival and risk of metastatic disease in renal cell carcinoma: a multicenter investigation

While microvascular invasion is an accepted risk factor in various cancers, its prognostic role in renal cell carcinoma is still unclear. Therefore, a large multicenter study examining the experience of 5 international institutions was performed to evaluate the prognostic value of microvascular invasion in the occurrence of metastases and cancer specific survival.

Cancer therapy modulates VEGF signaling and viability in adult rat cardiac microvascular endothelial cells and cardiomyocytes

This work was motivated by the incomplete characterization of the role of vascular endothelial growth factor-A (VEGF-A) in the stressed heart in consideration of upcoming cancer treatment options challenging the natural VEGF balance in the myocardium. We tested, if the cytotoxic cancer therapy doxorubicin (Doxo) or the anti-angiogenic therapy sunitinib alters viability and VEGF signaling in primary cardiac microvascular endothelial cells (CMEC) and adult rat ventricular myocytes (ARVM). ARVM were isolated and cultured in serum-free medium. CMEC were isolated from the left ventricle and used in the second passage. Viability was measured by LDH-release and by MTT-assay, cellular respiration by high-resolution oxymetry. VEGF-A release was measured using a rat specific VEGF-A ELISA-kit. CMEC were characterized by marker proteins including CD31, von Willebrand factor, smooth muscle actin and desmin. Both Doxo and sunitinib led to a dose-dependent reduction of cell viability. Sunitinib treatment caused a significant reduction of complex I and II-dependent respiration in cardiomyocytes and the loss of mitochondrial membrane potential in CMEC. Endothelial cells up-regulated VEGF-A release after peroxide or Doxo treatment. Doxo induced HIF-1α stabilization and upregulation at clinically relevant concentrations of the cancer therapy. VEGF-A release was abrogated by the inhibition of the Erk1/2 or the MAPKp38 pathway. ARVM did not answer to Doxo-induced stress conditions by the release of VEGF-A as observed in CMEC. VEGF receptor 2 amounts were reduced by Doxo and by sunitinib in a dose-dependent manner in both CMEC and ARVM. In conclusion, these data suggest that cancer therapy with anthracyclines modulates VEGF-A release and its cellular receptors in CMEC and ARVM, and therefore alters paracrine signaling in the myocardium.

Microvascular response to shock wave application in striated skin muscle

This study aims to quantify by intravital microscopy the microhemodynamic response after extracorporeal shock wave application (ESWA) to the physiologic microcirculation of the mouse dorsal skinfold chamber.

[Thirty years of laser-assisted microvascular anastomosis (LAMA): what are the clinical perspectives?]

Since the first studies by Jain and Gorisch (1979), laser-assisted anastomoses have been steadily developed to a stage where clinical use is within reach. The laser-assisted vascular microanastomosis (LAMA) procedure is performed more quickly than conventional anastomosis, the surgically induced vessel damage is limited, and reduced bleeding after unclamping is observed.

Renal vein obstruction and orthostatic proteinuria: a review

The cause of orthostatic proteinuria is not clear but may often relate to obstruction of the left renal vein in the fork between the aorta and the superior mesenteric artery (=renal nutcracker). However, reports dealing with proteinuria only marginally refer to this possible cause of orthostatic proteinuria. We analysed the corresponding literature.