Lokalisation und Gen - Expressionsregulation der neutralen Endopeptidase in der humanen Prostata

Die neutrale Endopeptidase (NEP, EC 3.4.24.11; weitere Synonyme: Neprilysin, CD 10, CALLA) ist ein Typ II - integrales Membranenzym in Säugerzellen, die als Zink enthaltende Endopeptidase die lokale Konzentrationen der Peptidsubstrate und der dazugehörigen Peptid-vermittelten Signalübertragungsprozesse steuern kann. Im Gegensatz zu den anregendaten, die von NEP-Aktivität und -Regulation in den Prostataepithelzellen handeln, nur einige Studien sind auf dem zellularen Expression und der Lokalisation der NEP in den Stromal- und Karzinom-zellen der Prostata vorhanden. Um zu prüfen, ob Unterschiede in der NEP-Verteilung in der normalen und der pathologisch veränderten Prostata als auch in der Prostatazellen bestehen, wurde die NEP-Lokalisation mit Hilfe der indirekten Immunfluoreszenz - Methode an Prostatazellen und Paraffinschnitten der humanen Prostata untersucht. In der normalen adulten Prostata, wurde die NEP hauptsächlich an der apikalen Plasmamembran detektiert. Im Stroma wurden die Endothelzellen der Kapillaren und einige glatte Muskelzellen schwach gefärbt. In hyperplastischen Drüsen war die Immunreaktivität der NEP in den adluminalen Zellen an der apikalen Plasmamembran nachzuweisen. Im Stroma wurden auch die Endothelzellen der Kapillaren und glatte Muskelzellen gefärbt. Im Prostatakarzinom war meist eine generalisierte Immunreaktivität der Zellen vorhanden und die NEP war nicht auf die apikale Plasmamembran beschränkt. Sie verteilte sich vielmehr im gesamten Zytoplasma und ist damit offensichtlich ein Indikator für den Polaritäts- bzw. Differenzierungsverlust in anaplastischen Prostata-karzinomzellen. Die LNCaP zeigten eine intensive Färbung der Plasmamembran, das gesamte Zytoplasma wurde schwächer gefärbt, während die hPCPs nach Inkubation mit dem Antikörper nur eine schwache Reaktion in Zytoplasma aufwiesen. NEP-Genexpression wurde von RT-PCR überwacht, und NEP mRNA im menschlichen Prostatagewebe und in Prostatazellen wurde mittels in-situ-RT-PCR ermittelt. Prostatagewebe zeigte starke Signale im glandulären Epithel und schwache Signale im Stroma, kultivierte Zellen zeigten starke Signale in den Prostatakrebszellen (LNCaP) und schwache Signale in den stromal Zellen an (hPCPs). Die NEP-Protein wurde mit Hilfe der Westernblot-Analyse an Lysaten der epithelialen LNCaP und der stromalen hPCPs nachgewiesen. Die Experimente bestätigen den Expression von NEP nach beiden Zelle Arten, jedoch zeigte das Experiment mit hPCPs Zellen zwei Bänder. Um zu untersuchen, ob Androgene und Neuropeptide in die Expression der NEP in LNCaP- bzw. hPCPs-Zellen involviert sind, wurde die Expression der NEP durch Northern-Blot-Analyse der Total-RNA untersucht. Ohne Stimulation ist eine grundlegende NEP-Expression in den LNCaP-Zellen detektierbar, Die Behandlung mit DHT bzw. Bombesin führt zu einer 4-Fach-Erhöhung der NEP-Expression. In den hPCPs-Zellen ist kaum eine NEP-Expression detektierbar und die Expression ist unabhängig von DHT- oder Bombesin-Stimulation. Die basale NEP-Expression in den hPCPs-Zellen besitzt im Vergleich zu den LNCaP-Zellen nur eine um ca. 30% Menge. Die Sequenzanalyse des NEP-Promotors deckt zwei Androgenresponsionselemente einschließlich ein typisches ARE auf, welches Androgen-, Progesteron- und Glukocorticoid-Receptoren bindet und ein einzigartiges ARR, das nur Androgenreceptor bindet. Durch Deletionsanalyse und Transfektionsexperiment der Promotorkonstrukte wurden mehre cis-regulatorische Elemente am NEP-Typ II Promotor identifiziert. Mit Deletionsanalyse und Transfektionsexperiment der Promotorkonstrukte, DNase I Footprinting und Bandshift wurden zwei an die proximale Promotorregion bindene Faktoren identifiziert, ein Sp-Faktor an der GC-Box von -250 bis -262 bindet und ein NF-Y Faktor an der CCAAT-Box im Schutzbereich -142 / -110 des Promotors bindet. Transfektion des Reportergenkonstruktes mit durch Mutation standene Variation der Verbindungsstelle, die in EMSAs die DNA-Bindung blockieren kann, zeigte, daß NF-Y für die basale Aktivität des Promotors wichtig ist und daß der Sp-Faktor wichtig für die Androgen-Responsewirkung des Androgen-Responseelements ist

The Role of Local Intrinsic Dimensionality in Benchmarking Nearest Neighbor Search

This paper reconsiders common benchmarking approaches to nearest neighbor search. It is shown that the concept of local intrinsic dimensionality (LID) allows to choose query sets of a wide range of difficulty for real-world datasets. Moreover, the effect of different LID distributions on the running time performance of implementations is empirically studied. To this end, different visualization concepts are introduced that allow to get a more fine-grained overview of the inner workings of nearest neighbor search principles. The paper closes with remarks about the diversity of datasets commonly used for nearest neighbor search benchmarking. It is shown that such real-world datasets are not diverse: results on a single dataset predict results on all other datasets well.Comment: Preprint of the paper accepted at SISAP 201

Accurate and Fast Retrieval for Complex Non-metric Data via Neighborhood Graphs

We demonstrate that a graph-based search algorithm-relying on the construction of an approximate neighborhood graph-can directly work with challenging non-metric and/or non-symmetric distances without resorting to metric-space mapping and/or distance symmetrization, which, in turn, lead to substantial performance degradation. Although the straightforward metrization and symmetrization is usually ineffective, we find that constructing an index using a modified, e.g., symmetrized, distance can improve performance. This observation paves a way to a new line of research of designing index-specific graph-construction distance functions

Legal Paradigm Shifts and Their Impacts on the Socio-Spatial Exclusion of Asylum Seekers in Denmark

This chapter discusses the genesis of Denmark’s asylum accommodation system and recent legal and socio-spatial changes as a reaction to the increase of arrivals. By elucidating the structures and objectives of asylum accommodation, I present that the state’s further tightening of restrictive reception and accommodation policies significantly impacts the socio-spatial configurations of accommodations, refugees’ access to housing and their well-being. I discuss the links between the tensioning of laws, the reduction of living conditions and the (re-)constitution of large accommodations as means of socio-spatial exclusion. Applying the case of Denmark’s Hovedstaden Region (Capital Region), I finally argue that asylum accommodation is a central instrument of Denmark’s approaches to strategically isolate forced migrants and to deter them from migrating to Denmark

The Randomized Slicer for CVPP: Sharper, Faster, Smaller, Batchier

Following the recent line of work on solving the closest vector problem with preprocessing (CVPP) using approximate Voronoi cells, we improve upon previous results in the following ways:-We derive sharp asymptotic bounds on the success probability of the randomized slicer, by modelling the behaviour of the algorithm as a random walk on the coset of the lattice of the target vector. We thereby solve the open question left by Doulgerakis\xe2\x80\x93Laarhoven\xe2\x80\x93De Weger [PQCrypto 2019] and Laarhoven\xc2\xa0[MathCrypt 2019].-We obtain better trade-offs for CVPP and its generalisations (strictly, in certain regimes), both with and without nearest neighbour searching, as a direct result of the above sharp bounds on the success probabilities.-We show how to reduce the memory requirement of the slicer, and in particular the corresponding nearest neighbour data structures, using ideas similar to those proposed by Becker\xe2\x80\x93Gama\xe2\x80\x93Joux [Cryptology ePrint Archive, 2015]. Using 20.185d+o(d)memory, we can solve a single CVPP instance in 20.264d+o(d)time.-We further improve on the per-instance time complexities in certain memory regimes, when we are given a sufficiently large batch of CVPP problem instances for the same lattice. Using memory, we can heuristically solve CVPP instances in amortized time, for batches of size at least.Our random walk model for analysing arbitrary-step transition probabilities in complex step-wise algorithms may be of independent interest, both for deriving analytic bounds through convexity arguments, and for computing optimal paths numerically with a shortest path algorithm. As a side result we apply the same random walk model to graph-based nearest neighbour searching, where we improve upon results of Laarhoven [SOCG 2018] by deriving sharp bounds on the success probability of the corresponding greedy search procedure

Morphological evidences indicate that the interference of cimetidine on the peritubular components is responsible for detachment and apoptosis of Sertoli cells

Cimetidine, referred as antiandrogenic agent, has caused alterations in the seminiferous tubules, including alterations in the peritubular tissue and death of myoid cells by apoptosis. Regarding the structural and functional importance of the peritubular tissue for the maintenance of Sertoli cells (SC), we purpose to investigate the SC-basement membrane interface, focusing the morphological features of SC and their interaction with the basement membrane in the affected tubules by cimetidine. Ten animals were distributed into two groups, control (CG) and cimetidine (CmG) which received saline solution and 50 mg of cimetidine per kg of body weight, respectively, for 52 days. The testes were fixed, dehydrated and embedded for analyses under light and transmission electron microscopy. Paraffin sections were submitted to the TUNEL method; sections of testes embedded in glycol methacrylate were submitted to PAS method and stained by H&E for morphological and quantitative analyses of Sertoli Cells. In the CmG, the SC nuclei were positive to the TUNEL method and showed typical morphological alterations of cell death by apoptosis (from early to advanced stages). A significant reduction in the number of Sertoli Cells was probably due to death of these cells by apoptosis. A close relationship between SC nuclear alterations (including a high frequency of dislocated nuclei from the basal portion) and damage in the peritubular tissue was observed. The ultrastructural analysis showed a parallelism between the gradual advancement of apoptotic process in SC and detachment of the anchoring sites (hemidesmosomes) of SC plasma membrane from the lamina densa. The presence of portions of lamina densa underlying the detached hemidesmosomes indicates a continuous deposition of lamina densa, resulting in the thickening of the basal lamina. The results indicate a possible disarrangement of the SC cytoskeleton, including the focal adhesion structure. These alterations are related to SC apoptosis and probably result from disturbs induced by cimetidine on the peritubular tissue

Targeted disruption of Slc2a8 (GLUT8) reduces motility and mitochondrial potential of spermatozoa

GLUT8 is a class 3 sugar transport facilitator which is predominantly expressed in testis and also detected in brain, heart, skeletal muscle, adipose tissue, adrenal gland, and liver. Since its physiological function in these tissues is unknown, we generated a Slc2a8 null mouse and characterized its phenotype. Slc2a8 knockout mice appeared healthy and exhibited normal growth, body weight development and glycemic control, indicating that GLUT8 does not play a significant role for maintenance of whole body glucose homeostasis. However, analysis of the offspring distribution of heterozygous mating indicated a lower number of Slc2a8 knockout offspring (30.5:47.3:22.1%, Slc2a8+/+, Slc2a8+/−, and Slc2a8−/− mice, respectively) resulting in a deviation (p = 0.0024) from the expected Mendelian distribution. This difference was associated with lower ATP levels, a reduced mitochondrial membrane potential and a significant reduction of sperm motility of the Slc2a8 knockout in comparison to wild-type spermatozoa. In contrast, number and survival rate of spermatozoa were not altered. These data indicate that GLUT8 plays an important role in the energy metabolism of sperm cells

Reticular synthesis and the design of new materials

The long-standing challenge of designing and constructing new crystalline solid-state materials from molecular building blocks is just beginning to be addressed with success. A conceptual approach that requires the use of secondary building units to direct the assembly of ordered frameworks epitomizes this process: we call this approach reticular synthesis. This chemistry has yielded materials designed to have predetermined structures, compositions and properties. In particular, highly porous frameworks held together by strong metal-oxygen-carbon bonds and with exceptionally large surface area and capacity for gas storage have been prepared and their pore metrics systematically varied and functionalized.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62718/1/nature01650.pd