399 research outputs found

    HIV-assoziiertes Lymphom — ungewöhnliche Ursache einer pathologischen Unterkieferfraktur: Fallbericht und Behandlungsoptionen bei Immundefizienz

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    Zusammenfassung: Das diffuse großzellige B-Zell-Lymphom (DGBZL) bleibt trotz der Einführung der kombinierten antiviralen Therapie (HAART) ein häufiger maligner Tumor bei HIV-infizierten Patienten. Über 50% dieser Lymphome verlaufen extranodal, davon manifestiert sich die Hälfte in der Kopf-Hals-Region. Bei oralen Manifestationen zählen Schmerzen, Schwellung, Parästhesien und Zahnlockerungen zu den ersten klinischen Symptomen. Im vorliegenden Beitrag wird über einen 52-jährigen Patienten mit einer Fraktur im linken Kieferwinkelbereich bei bekannter HIV-Infektion berichtet. Eine primäre osteosynthetische Versorgung brachte diese nicht zur Ausheilung. Die anlässlich der Revision durchgeführte Biopsie ergab die Diagnose eines primären Lymphoms im Unterkiefer. Eine Konsolidierung der Defektfraktur trat erst nach dessen Vollremission und nachfolgender Rekonstruktion mit freiem kortikospongiösem Beckenkammtransplantat auf. Anhand dieser Kasuistik werden nach Darstellung des Krankheitsbildes die Therapieoptionen bei Unterkieferfrakturen im Rahmen einer Immundefizienz vor dem Hintergrund der verfügbaren Literatur diskutier

    Estrategias de marketing cinematográfico aplicadas por Tondero Producciones. Estudio de las películas Guerrero y Solos

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    Analiza los diferentes momentos y componentes del marketing mundial aplicado en dos películas nacionales producidas por la compañía realizadora Tondero y cómo dicha comunicación varia dependiendo del público y tipo de explotación. Para el análisis se eligió las películas Solos y Guerrero, al ser películas con cortes, públicos y modelos de distribución distintos y al estar actualmente en su proceso publicitario

    Thermodynamics of wetting, prewetting and surface phase transitions with surface binding

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    In living cells, protein-rich condensates can wet the cell membrane and surfaces of membrane-bound organelles. Interestingly, many phase-separating proteins also bind to membranes leading to a molecular layer of bound molecules. Here we investigate how binding to membranes affects wetting, prewetting and surface phase transitions. We derive a thermodynamic theory for a three-dimensional bulk in the presence of a two-dimensional, flat membrane. At phase coexistence, we find that membrane binding facilitates complete wetting and thus lowers the wetting angle. Moreover, below the saturation concentration, binding facilitates the formation of a thick layer at the membrane and thereby shifts the prewetting phase transition far below the saturation concentration. The distinction between bound and unbound molecules near the surface leads to a large variety of surface states and complex surface phase diagrams with a rich topology of phase transitions. Our work suggests that surface phase transitions combined with molecular binding represent a versatile mechanism to control the formation of protein-rich domains at intra-cellular surfaces

    Coaligned dual-channel STED nanoscopy and molecular diffusion analysis at 20 nm resolution.

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    We report on a fiber laser-based stimulated emission-depletion microscope providing down to ~20 nm resolution in raw data images as well as 15–19 nm diameter probing areas in fluorescence correlation spectroscopy. Stimulated emission depletion pulses of nanosecond duration and 775 nm wavelength are used to silence two fluorophores simultaneously, ensuring offset-free colocalization analysis. The versatility of this superresolution method is exemplified by revealing the octameric arrangement of Xenopus nuclear pore complexes and by quantifying the diffusion of labeled lipid molecules in artificial and living cell membranes

    Imitation modeling of the static process loading milling cutters

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    Myelin is a multilayered membrane that ensheathes axonal fibers in the vertebrate nervous system, allowing fast propagation of nerve action potentials. It contains densely packed lipids, lacks an actin-based cytocortex, and requires myelin basic protein (MBP) as its major structural component. This protein is the basic constituent of the proteinaceous meshwork that is localized between adjacent cytoplasmic membranes of the myelin sheath. Yet, it is not clear how MBP influences the organization and dynamics of the lipid constituents of myelin. Here, we used optical stimulated emission depletion super-resolution microscopy in combination with fluorescence correlation spectroscopy to assess the characteristics of diffusion of different fluorescent lipid analogs in myelin membrane sheets of cultured oligodendrocytes and in micrometer-sized domains that were induced by MBP in live epithelial PtK2 cells. Lipid diffusion was significantly faster and less anomalous both in oligodendrocytes and inside the MBP-rich domains of PtK2 cells compared with undisturbed live PtK2 cells. Our data show that MBP reorganizes lipid diffusion, possibly by preventing the buildup of an actin-based cytocortex and by preventing most membrane proteins from entering the myelin sheath region. Yet, in contrast to myelin sheets in oligodendrocytes, the MBP-induced domains in epithelial PtK2 cells demonstrate no change in lipid order, indicating that segregation of long-chain lipids into myelin sheets is a process specific to oligodendrocytes

    Leptin affects endocardial cushion formation by modulating EMT and migration via Akt signaling cascades

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    Blood circulation is dependent on heart valves to direct blood flow through the heart and great vessels. Valve development relies on epithelial to mesenchymal transition (EMT), a central feature of embryonic development and metastatic cancer. Abnormal EMT and remodeling contribute to the etiology of several congenital heart defects. Leptin and its receptor were detected in the mouse embryonic heart. Using an ex vivo model of cardiac EMT, the inhibition of leptin results in a signal transducer and activator of transcription 3 and Snail/vascular endothelial cadherin–independent decrease in EMT and migration. Our data suggest that an Akt signaling pathway underlies the observed phenotype. Furthermore, loss of leptin phenocopied the functional inhibition of αvβ3 integrin receptor and resulted in decreased αvβ3 integrin and matrix metalloprotease 2, suggesting that the leptin signaling pathway is involved in adhesion and migration processes. This study adds leptin to the repertoire of factors that mediate EMT and, for the first time, demonstrates a role for the interleukin 6 family in embryonic EMT

    Resonance Lifetimes from Complex Densities

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    The ab-initio calculation of resonance lifetimes of metastable anions challenges modern quantum-chemical methods. The exact lifetime of the lowest-energy resonance is encoded into a complex "density" that can be obtained via complex-coordinate scaling. We illustrate this with one-electron examples and show how the lifetime can be extracted from the complex density in much the same way as the ground-state energy of bound systems is extracted from its ground-state density

    Protective effect of leptin against ischemia-reperfusion injury in the rat small intestine

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    BACKGROUND: The small intestine is extremely sensitive to ischemia-reperfusion (I/R) injury and a range of microcirculatory disturbances which contribute to tissue damage. Previous studies have shown that leptin plays an important physiological role in the microvasculature. The aim of this study was to evaluate the protective effects of leptin in I/R – induced mucosal injury in the small intestine. METHODS: Forty rats were divided into 5 groups (n = 8). Group I was subjected to a sham operation. Following mesenteric ischemia in group II (control); physiologic saline 1 cm(3), in group III; leptin 100 μg/kg, and physiologic saline 1 cm(3), in group IV; N(G)-L-arginine methyl ester (L-NAME) 20 mg/kg, and physiologic saline 1 cm(3), in group V; leptin 100 μg/kg, L-NAME 20 mg/kg, and physiologic saline 1 cm(3 )were given intra-peritoneally. In these groups, an I/R procedure was performed by occlusion of the superior mesenteric artery for 45 min followed by 120 min reperfusion. After reperfusion, the small intestines were resected for malondialdehyde (MDA) and nitric oxide (NO) concentration and histopathologic properties. Mucosal lesions were scored between 0 and 5. Tissue MDA and NO concentration and histopathologic grades were compared statistically. RESULTS: Tissue MDA level significantly increased (P < 0.05), tissue NO level significantly decreased in group V animals, compared to group III animals respectively (P < 0.001). Histopathologically, intestinal injury significantly decreased in the leptin treated ischemic group. CONCLUSION: Leptin can be used safely in mesenteric occlusive diseases, since it induces NO formation and release in mesenteric vessels

    Body Mass Index, percent body fat, and regional body fat distribution in relation to leptin concentrations in healthy, non-smoking postmenopausal women in a feeding study

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    BACKGROUND: The relationship between BMI and leptin has been studied extensively in the past, but previous reports in postmenopausal women have not been conducted under carefully controlled dietary conditions of weight maintenance using precise measures of body fat distribution. The aim of the present study was to examine the association between serum leptin concentration and adiposity as estimated by BMI and dual energy x-ray absorptiometry (DEXA) measures (percent body fat, central and peripheral fat, and lean mass) in postmenopausal women. METHODS: This study was conducted as a cross-sectional analysis within the control segment of a randomized, crossover trial in which postmenopausal women (n = 51) consumed 0 (control), 15 (one drink), and 30 (two drinks) g alcohol (ethanol)/d for 8 weeks as part of a controlled diet. BMIs were determined and DEXA scans were administered to the women during the 0 g alcohol treatment, and a blood sample was collected at baseline and week 8 of each study period for leptin analysis. RESULTS AND DISCUSSION: In multivariate analysis, women who were overweight (BMI > 25 to ≤ 30 kg/m(2)) had a 2-fold increase, and obese women (BMI > 30 kg/m(2)) had more than a 3-fold increase in serum leptin concentrations compared to normal weight (BMI ≤25 kg/m(2)) women. When the models for the different measures of adiposity were assessed by multiple R(2), models which included percent body fat explained the highest proportion (approximately 80%) of the serum leptin variance. CONCLUSION: Under carefully controlled dietary conditions, we confirm that higher levels of adiposity were associated with higher concentrations of serum leptin. It appears that percent body fat in postmenopausal women may be the best adiposity-related predictor of serum leptin

    Vascular Endothelial Growth Factor Receptor-2 Couples Cyclo-Oxygenase-2 with Pro-Angiogenic Actions of Leptin on Human Endothelial Cells

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    The adipocyte-derived hormone leptin influences the behaviour of a wide range of cell types and is now recognised as a pro-angiogenic and pro-inflammatory factor. In the vasculature, these effects are mediated in part through its direct leptin receptor (ObRb)-driven actions on endothelial cells (ECs) but the mechanisms responsible for these activities have not been established. In this study we sought to more fully define the molecular links between inflammatory and angiogenic responses of leptin-stimulated human ECs../Akt/COX-2 signalling axis is required for leptin's pro-angiogenic actions and that this is regulated upstream by ObRb-dependent activation of VEGFR2. These studies identify a new function for VEGFR2 as a mediator of leptin-stimulated COX-2 expression and angiogenesis and have implications for understanding leptin's regulation of the vasculature in both non-obese and obese individuals
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