Doxorubicin Affects Testicular Lipids with Long-Chain (C18-C22) and Very Long-Chain (C24-C32) Polyunsaturated Fatty Acids

Doxorubicin disrupts spermatogenesis by causing apoptosis of spermatogonia and primary spermatocytes. The aim of this study was to examine the effect of this agent on adult rat testicular lipids and their fatty acids. A single dose (7.5 mg/kg) and a multidose regime (3 mg/kg once a week for 4 weeks) were evaluated. Both treatments resulted in the gradual loss of spermatogenic cells and determined a marked reduction in testicular size and weight 9 weeks after their start. Germ cell loss was accompanied by a decrease in phospholipids, including glycerophospholipids and sphingomyelin. Concomitantly, glycerophospholipids lost selectively their major polyunsaturated fatty acid (PUFA), 22:5n-6, and sphingomyelin lost its major very long-chain PUFA (VLCPUFA), 28:4n-6 and 30:5n-6. The molecular species from which the lost polyenes originated were thus a trait of germ cells. A transient peak of 16:0-ceramide was observed 48 h after the single dose. In both doxorubicin regimes, sphingomyelin and ceramide with reduced amounts of VLCPUFA after about 4 weeks and with no VLCPUFA after 9 weeks resulted. By contrast, triglycerides and especially cholesterol esters (CE) tended to accumulate in the testes undergoing germ cell death, probably in the surviving Sertoli cells, their fatty acid patterns suggesting that initially, these lipids retained part of the PUFA coming from, or no longer used for, the synthesis of germ cell glycerophospholipids. As the latter decreased, CE accumulated massively 9 weeks after starting doxorubicin treatment, 20:4n-6 becoming their major PUFA. Part of these CEs may derive from surviving steroidogenic cells.Fil: Zanetti, Samanta Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Maldonado, Eduardo N.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Aveldaño, Marta Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentin

Magnetresonanztomographie der Schulter: Impingement- und instabilitätsassoziierte Veränderungen

Zusammenfassung: Die MRT der Schulter spielt neben Anamnese und klinischer Untersuchung eine bedeutende Rolle bei der Diagnose und Differenzierung zahlreicher Schulterpathologien und der Abklärung chronischer Schulterschmerzen. Wichtige Indikationsgebiete der MRT sind die Evaluation der Rotatorenmanschette und des Labrum-Kapsel-Apparats. Besondere Bedeutung hat die Beurteilung der Rotatorenmanschettenmuskulatur. Die immer noch kontrovers diskutierte MR-Arthrographie zeigt ihr größtes Potenzial bei der präzisen Unterscheidung von kleinen Rotatorenmanschettenläsionen, Labrum-Kapsel-Läsionen und Läsionen der langen Bizepssehne. In dem Beitrag wird auf die häufigsten pathologischen Veränderungen des Schultergelenks eingegangen. Daneben wird gezeigt, wie die Befunde für Schulterorthopäden beschrieben und quantifiziert werde

Tuning and Robustness Analysis for the Orion Absolute Navigation System

The Orion Multi-Purpose Crew Vehicle (MPCV) is currently under development as NASA's next-generation spacecraft for exploration missions beyond Low Earth Orbit. The MPCV is set to perform an orbital test flight, termed Exploration Flight Test 1 (EFT-1), some time in late 2014. The navigation system for the Orion spacecraft is being designed in a Multi-Organizational Design Environment (MODE) team including contractor and NASA personnel. The system uses an Extended Kalman Filter to process measurements and determine the state. The design of the navigation system has undergone several iterations and modifications since its inception, and continues as a work-in-progress. This paper seeks to show the efforts made to-date in tuning the filter for the EFT-1 mission and instilling appropriate robustness into the system to meet the requirements of manned space ight. Filter performance is affected by many factors: data rates, sensor measurement errors, tuning, and others. This paper focuses mainly on the error characterization and tuning portion. Traditional efforts at tuning a navigation filter have centered around the observation/measurement noise and Gaussian process noise of the Extended Kalman Filter. While the Orion MODE team must certainly address those factors, the team is also looking at residual edit thresholds and measurement underweighting as tuning tools. Tuning analysis is presented with open loop Monte-Carlo simulation results showing statistical errors bounded by the 3-sigma filter uncertainty covariance. The Orion filter design uses 24 Exponentially Correlated Random Variable (ECRV) parameters to estimate the accel/gyro misalignment and nonorthogonality. By design, the time constant and noise terms of these ECRV parameters were set to manufacturer specifications and not used as tuning parameters. They are included in the filter as a more analytically correct method of modeling uncertainties than ad-hoc tuning of the process noise. Tuning is explored for the powered-flight ascent phase, where measurements are scarce and unmodelled vehicle accelerations dominate. On orbit, there are important trade-off cases between process and measurement noise. On entry, there are considerations about trading performance accuracy for robustness. Process Noise is divided into powered flight and coasting ight and can be adjusted for each phase and mode of the Orion EFT-1 mission. Measurement noise is used for the integrated velocity measurements during pad alignment. It is also used for Global Positioning System (GPS) pseudorange and delta- range measurements during the rest of the flight. The robustness effort has been focused on maintaining filter convergence and performance in the presence of unmodeled error sources. These include unmodeled forces on the vehicle and uncorrected errors on the sensor measurements. Orion uses a single-frequency, non-keyed GPS receiver, so the effects due to signal distortion in Earth's ionosphere and troposphere are present in the raw measurements. Results are presented showing the efforts to compensate for these errors as well as characterize the residual effect for measurement noise tuning. Another robustness tool in use is tuning the residual edit thresholds. The trade-off between noise tuning and edit thresholds is explored in the context of robustness to errors in dynamics models and sensor measurements. Measurement underweighting is also presented as a method of additional robustness when processing highly accurate measurements in the presence of large filter uncertainties

Early postoperative MRI in detecting hematoma and dural compression after lumbar spinal decompression: prospective study of asymptomatic patients in comparison to patients requiring surgical revision

Early postoperative MRI after spinal surgery is difficult to interpret because of confounding postoperative mass effects and frequent occurrence of epidural hematomas. Purpose of this prospective study is to evaluate prevalence, extent and significance of hematoma in the first postoperative week in asymptomatic patients after decompression for lumbar stenosis and to determine the degree of clinically significant dura compression by comparing with the patients with postoperative symptoms. MRI was performed in 30 asymptomatic patients (47 levels) in the first week after lumbar spine decompression for degenerative stenosis. Eleven patients requiring surgical revision (16 levels) for symptomatic early postoperative hematoma were used for comparison. In both groups the cross-sectional area of the maximum dural compression (bony stenosis and dural sac expansion) was measured preoperatively and postoperatively by an experienced radiologist. Epidural hematoma was seen in 42.5% in asymptomatic patients (20/47 levels). The median area of postoperative hematoma at the operated level was 176mm2 in asymptomatic patients and 365mm2 in symptomatic patients. The median cross-sectional area of the dural sac at the operated level was 128.5 and 0mm2 in asymptomatic and symptomatic patients, respectively, at the site of maximal compression. In the symptomatic group 75% of the patients had a maximal postoperative dural sac area of 58.5mm2 or less, whereas in the asymptomatic group 75% of patients with epidural hematoma had an area of 75mm2 or more. The size of hematoma and the degree of dural sac compression were significantly larger in patients with symptoms needing surgical revision. Dural sac area of less than 75mm2 in early postoperative MRI was found to be the threshold for clinical significanc

A Framework for Scaling in Filtering and Linear Covariance Analysis

Scaling is used extensively for numerical optimization and trajectory optimization. Its use in the estimation community is almost nonexistent. This paper creates the framework for practical scaling in space navigation, in general, and linear covariance analysis, in particular

Genetic variation and relationships among spring camelina (Camelina sativa, Brassicaceae) accessions of different origin

Camelina sativa L. is one of the oldest crops of the Brassicaceae family, first domesticated in the region of south-eastern Europe. It has regained interest as a very promising alternative oilseed crop with broad adaptability, a wide range of tolerances to pests and diseases, and low-input requirements. The genetic diversity in spring camelina proved to be limited, so the identification and characterization of genetic variations is considered very useful for development of efficient breeding programmes. The aim of the study was to use SSR markers in order to investigate genetic variation of twenty spring camelina accessions and their relatedness. Forty-five individual samples were taken from each accession and used for amplification of SSR markers P4C11, P6E4 and LIB19. The accessions expressed different levels of genetic variation, AMOVA (analysis of molecular variance) showed that 64% of the total genetic variation was attributed to variance within accessions. Genetic distance analysis indicated that there was overlapping in certain breeding programs and exchange of breeding germplasm

Composición y estructura de la vegetación epífita vascular en un bosque primario de Olivillo (Aextoxicon punctatum R. et P.) en el sur de Chile

Vascular epiphytes represent 10% of the total vascular plants of the world. Nevertheless, because it is hard to reach them in the forest upper-canopy where they usually live, there are few studies (especially in Chile) about them. With the objective of identifying the vascular epiphytes growing on tree stems (under 1.5 m height), we sampled three transects in an Olivillo old-growth stand, in the Rucamanque forest, in the central valley of south-central Chile, near the city of Temuco. Several variables were measured for both the vascular epiphytes and their host-trees. We studied the floristic composition of the vascular epiphytes community, and their relationship with their host-trees, as well as their sociability, cover, and frequency. Eight vascular epiphytes species were identified, corresponding to four genus distributed in three families: Hymenophyllum and Hymenoglossum (Hymenophyllaceae), Asplenium (Aspleniaceae) and Sarmienta (Gesneriaceae). We found only a non-statistically significant linear correlation between vascular epiphytes and their host-trees. We determined that Hymenophyllum cuneatum was the most important vascular epiphytes species

α-SNAP Prevents Docking of the Acrosome during Sperm Exocytosis because It Sequesters Monomeric Syntaxin

α-SNAP has an essential role in membrane fusion that consists of bridging cis SNARE complexes to NSF. α-SNAP stimulates NSF, which releases itself, α-SNAP, and individual SNAREs that subsequently re-engage in the trans arrays indispensable for fusion. α-SNAP also binds monomeric syntaxin and NSF disengages the α-SNAP/syntaxin dimer. Here, we examine why recombinant α-SNAP blocks secretion in permeabilized human sperm despite the fact that the endogenous protein is essential for membrane fusion. The only mammalian organism with a genetically modified α-SNAP is the hyh mouse strain, which bears a M105I point mutation; males are subfertile due to defective sperm exocytosis. We report here that recombinant α-SNAP-M105I has greater affinity for the cytosolic portion of immunoprecipitated syntaxin than the wild type protein and in consequence NSF is less efficient in releasing the mutant. α-SNAP-M105I is a more potent sperm exocytosis blocker than the wild type and requires higher concentrations of NSF to rescue its effect. Unlike other fusion scenarios where SNAREs are subjected to an assembly/disassembly cycle, the fusion machinery in sperm is tuned so that SNAREs progress uni-directionally from a cis configuration in resting cells to monomeric and subsequently trans arrays in cells challenged with exocytosis inducers. By means of functional and indirect immunofluorescense assays, we show that recombinant α-SNAPs — wild type and M105I — inhibit exocytosis because they bind monomeric syntaxin and prevent this SNARE from assembling with its cognates in trans. Sequestration of free syntaxin impedes docking of the acrosome to the plasma membrane assessed by transmission electron microscopy. The N-terminal deletion mutant α-SNAP-(160–295), unable to bind syntaxin, affects neither docking nor secretion. The implications of this study are twofold: our findings explain the fertility defect of hyh mice and indicate that assembly of SNAREs in trans complexes is essential for docking