963 resultados para 2 Normal Distributions
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In this thesis we give a definition of the term logarithmically symplectic variety; to be precise, we distinguish even two types of such varieties. The general type is a triple $(f,nabla,omega)$ comprising a log smooth morphism $fcolon Xtomathrm{Spec}kappa$ of log schemes together with a flat log connection $nablacolon LtoOmega^1_fotimes L$ and a ($nabla$-closed) log symplectic form $omegainGamma(X,Omega^2_fotimes L)$. We define the functor of log Artin rings of log smooth deformations of such varieties $(f,nabla,omega)$ and calculate its obstruction theory, which turns out to be given by the vector spaces $H^i(X,B^bullet_{(f,nabla)}(omega))$, $i=0,1,2$. Here $B^bullet_{(f,nabla)}(omega)$ is the class of a certain complex of $mathcal{O}_X$-modules in the derived category $mathrm{D}(X/kappa)$ associated to the log symplectic form $omega$. The main results state that under certain conditions a log symplectic variety can, by a flat deformation, be smoothed to a symplectic variety in the usual sense. This may provide a new approach to the construction of new examples of irreducible symplectic manifolds.
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In dieser Arbeit wurde die paritätsverletzende Asymmetrie in derrnquasielastischen Elektron-Deuteron-Streuung bei Q^2=0.23 (GeV/c)^2 mitrneinem longitudinal polarisierten Elektronstrahl bei einer Energie von 315rnMeV bestimmt. Die Messung erfolgte unter Rückwärtswinkeln. Der Detektor überdeckte einen polaren Streuwinkelbereichrnzwischen 140 und 150 deg. Das Target bestand aus flüssigemrnDeuterium in einer Targetzelle mit einer Länge von 23.4 cm. Dierngemessene paritätsverletzende Asymmetrie beträgt A_{PV}^d = (-20.11 pm 0.87_{stat} pm 1.03_{syst}), wobei der erste Fehler den statistischenrnFehlereitrag und der zweite den systematischen Fehlerbeitrag beschreibt. Ausrnder Kombination dieser Messung mit Messungen der paritätsverletzendenrnAsymmetrie in der elastischen Elektron-Proton-Streuung bei gleichem Q^2rnsowohl bei Vorwärts- als auch bei Rückwärtsmessungen können diernVektor-Strange-Formfaktoren sowie der effektive isovektorielle und isoskalarernVektorstrom des Protons, der die elektroschwachen radiativen Anapolkorrekturenrnenthält, bestimmt werden. Diese Arbeit umfasst ausserdem die Bestimmungrnder Asymmetrien bei einem transversal polarisierten Elektronstrahl sowohl beirneinem Proton- als auch einem Deuterontarget unter Rückwärtswinkeln beirnImpulsüberträgen von Q^2=0.10 (GeV/c)^2, Q^2=0.23 (GeV/c)^2rnund Q^2=0.35 (GeV/c)^2. Die im Experiment beobachteten Asymmetrien werdenrnmit theoretischen Berechnungen verglichen, welche den Imaginärteil der Zweiphoton-Austauschamplitude beinhalten.
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Expression of N-myc downregulated gene 1 (NDRG1) is associated with growth arrest and differentiation of tumor cells. In hematopoietic cells, NDRG1 was identified in a screen for differentiation-related genes in human myelomonocytic leukemic U937 cells. In the present study, we found significantly higher NDRG1 mRNA levels in granulocytes of healthy donors than in primary acute myeloid leukemia (AML) cells. Another NDRG family member, NDRG2, was significantly higher expressed in normal macrophages compared to primary AML cells. Moreover, NDRG1 mRNA levels increased in two acute promyelocytic leukemia (APL) patients as well as in NB4 and HT93 APL cells upon all-trans retinoic acid (ATRA) therapy. In line with these observations, silencing of NDRG1 diminished neutrophil differentiation of leukemic cell lines. In conclusion, we found an association of low NDRG1 levels with an immature cell phenotype and provide evidence that NDRG1 is functionally involved in neutrophil maturation.
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Introduction Intracranial pressure monitoring is commonly implemented in patients with neurologic injury and at high risk of developing intracranial hypertension, to detect changes in intracranial pressure in a timely manner. This enables early and potentially life-saving treatment of intracranial hypertension. Case presentation An intraparenchymal pressure probe was placed in the hemisphere contralateral to a large basal ganglia hemorrhage in a 75-year-old Caucasian man who was mechanically ventilated and sedated because of depressed consciousness. Intracranial pressures were continuously recorded and never exceeded 17 mmHg. After sedation had been stopped, our patient showed clinical signs of transtentorial brain herniation, despite apparently normal intracranial pressures (less than 10 mmHg). Computed tomography revealed that the size of the intracerebral hematoma had increased together with significant unilateral brain edema and transtentorial herniation. The contralateral hemisphere where the intraparenchymal pressure probe was placed appeared normal. Our patient underwent emergency decompressive craniotomy and was tracheotomized early, but did not completely recover. Conclusions Intraparenchymal pressure probes placed in the hemisphere contralateral to an intracerebral hematoma may dramatically underestimate intracranial pressure despite apparently normal values, even in the case of transtentorial brain herniation.
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Diagnostic coronary balloon occlusion (CBO) is mandatory for collateral function assessment, during angioscopy and optical coherence imaging, and when using certain coronary protection devices against emboli. Thus far, the safety of diagnostic CBO regarding procedural and long-term complications in normal coronary arteries has not been studied. In 316 patients, diagnostic CBO was performed for collateral function measurement in 426 angiographically normal vessels. The angioplasty balloon was inflated for 60 to 120 seconds using inflation pressures of 1 to 3 atm, followed by control angiography during and after CBO. Patients were divided into groups with entirely normal (n = 133) and partially normal (n = 183) vessels. Primary end points were procedural and long-term complications. De novo stenosis development was assessed by quantitative coronary angiography in 35% of the patients. Secondary end points were cardiac events at 5 years of follow-up. Procedural complications occurred in 1 patient (0.2%). In 150 repeat angiographic procedures in 92 patients (follow-up duration 10 +/- 15 months), quantitative coronary angiography revealed no difference in percentage diameter narrowing between baseline and follow-up (4.1% vs 3.9%, p = 0.69). During follow-up periods of 14 and 72 months, respectively, a new stenotic lesion was detected in 1 patient in each group (1.3%). Major cardiac events and percutaneous coronary intervention for stable angina were less frequent in the group with entirely normal than with partially normal vessels (0.8% vs 5.5%, p = 0.02, and 0.8% vs 18%, p <0.0001). In conclusion, low-inflation pressure diagnostic CBO in angiographically normal coronary arteries bears a minimal risk for procedural and long-term complications and can therefore be regarded as a safe procedure.
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Objective: Central to the process of osseointegration is the recruitment of mesenchymal progenitor cells to the healing site, their proliferation and differentiation to bone synthesising osteoblasts. The process is under the control of pro-inflammatory cytokines and growth factors. The aim of this study was to monitor these key stages of osseointegration and the signalling milieu during bone healing around implants placed in healthy and diabetic bone. Methods: Implants were placed into the sockets of incisors extracted from the mandibles of normal Wistar and diabetic Goto-Kakizaki rats. Mandibles 1-12 weeks post-insertion of the implant were examined by histochemistry and immunocytochemistry to localise the presence of Stro-1- positive mesenchymal progenitor cells, proliferating cellular nuclear antigen proliferative cells, osteopontin and osteocalcin, macrophages, pro-inflammatory cytokines interleukin (IL)-1 , IL-6, tumour necrosis factor (TNF)- and tumour growth factor (TGF)- 1. Image analysis provided a semi-quantification of positively expressing cells. Results: Histological staining identified a delay in the formation of mineralised bone around implants placed in diabetic animals. Within the diabetic bone, the migration of Stro-1 mesenchymal cells in the healing tissue appeared to be unaffected. However, in the diabetic healing bone, the onset of cell proliferation and osteoblast differentiation were delayed and subsequently prolonged compared with normal bone. Similar patterns of change were observed in diabetic bone for the presence of IL-1 , TNF- , macrophages and TGF- 1. Conclusion: The observed alterations in the extracellular presence of pro-inflammatory cytokines, macrophages and growth factors within diabetic tissues that correlate to changes in the signalling milieu, may affect the proliferation and differentiation of mesenchymal progenitor cells in the osseointegration process. To cite this article: Colombo JS, Balani D, Sloan AJ, St Crean J, Okazaki J, Waddington RJ. Delayed osteoblast differentiation and altered inflammatory response around implants placed in incisor sockets of type 2 diabetic rats Clin. Oral Impl. Res22, 2011; 578-586 doi: 10.1111/j.1600-0501.2010.01992.x.
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The G(βγ)-sequestering peptide β-adrenergic receptor kinase (βARK)ct derived from the G-protein-coupled receptor kinase (GRK)2 carboxyl terminus has emerged as a promising target for gene-based heart failure therapy. Enhanced downstream cAMP signaling has been proposed as the underlying mechanism for increased β-adrenergic receptor (βAR) responsiveness. However, molecular targets mediating improved cardiac contractile performance by βARKct and its impact on G(βγ)-mediated signaling have yet to be fully elucidated.
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Activation of prosurvival kinases and subsequent nitric oxide (NO) production by certain G protein-coupled receptors (GPCRs) protects myocardium in ischemia/reperfusion injury (I/R) models. GPCR signaling pathways are regulated by GPCR kinases (GRKs), and GRK2 has been shown to be a critical molecule in normal and pathological cardiac function.
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OBJECTIVE To determine the practicability and accuracy of central corneal thickness (CCT) measurements in living chicks utilizing a noncontact, high-speed optical low-coherence reflectometer (OLCR) mounted on a slit lamp. ANIMALS STUDIED Twelve male chicks (Gallus gallus domesticus). Procedures Measurements of CCT were obtained in triplicate in 24 eyes of twelve 1-day-old anaesthetized chicks using OLCR. Every single measurement taken by OLCR consisted of the average result of 20 scans obtained within seconds. Additionally, corneal thickness was determined histologically after immersion fixation in Karnovsky's solution alone (20 eyes) or with a previous injection of the fixative into the anterior chamber before enucleation (4 eyes). RESULTS Central corneal thickness measurements using OLCR in 1-day-old living chicks provide a rapid and feasible examination technique. Mean CCT measured with OLCR (189.7 ± 3.34 μm) was significantly lower than histological measurements (242.1 ± 47.27 μm) in eyes with fixation in Karnovsky's solution (P = 0.0005). In eyes with additional injection of Karnovsky's fixative into the anterior chamber, mean histologically determined CCT was 195.2 ± 8.25 μm vs. 191.9 ± 8.90 μm with OLCR. A trend for a lower variance was found compared to the eyes that had only been immersion fixed. CONCLUSION Optical low-coherence reflectometry is an accurate examination technique to measure in vivo CCT in the eye of newborn chicks. The knowledge of the thickness of the chick cornea and the ability to obtain noninvasive, noncontact measurements of CCT in the living animal may be of interest for research and development of eye diseases in chick models.
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Matrix metalloproteinases (MMP), particularly MMP-2 and MMP-9, participate in tumour progression and metastasis in various cancers. Their significance in urothelial cancer of the bladder (UCB) is unclear. Expression analysis of MMP-2 and MMP-9 in tissue microarrays (TMA) constructed of corresponding samples from histopathological normal urothelium, tumour centre and invasion front of primary tumours and lymph-node (LN) metastases might help to elucidate their relevance in UCB.
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Severe ADAMTS13 deficiency is a critical component of the pathogenesis of idiopathic thrombotic thrombocytopenic purpura but is found only in about 60% of patients clinically diagnosed with this disease.
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We tested normal young and elderly adults and elderly Alzheimer’s disease (AD) patients on recognition memory for tunes. In Experiment 1, AD patients and age-matched controls received a study list and an old/new recognition test of highly familiar, traditional tunes, followed by a study list and test of novel tunes. The controls performed better than did the AD patients. The controls showed the “mirror effect” of increased hits and reduced false alarms for traditional versus novel tunes, whereas the patients false-alarmed as often to traditional tunes as to novel tunes. Experiment 2 compared young adults and healthy elderly persons using a similar design. Performance was lower in the elderly group, but both younger and older subjects showed the mirror effect. Experiment 3 produced confusion between preexperimental familiarity and intraexperimental familiarity by mixing traditional and novel tunes in the study lists and tests. Here, the subjects in both age groups resembled the patients of Experiment 1 in failing to show the mirror effect. Older subjects again performed more poorly, and they differed qualitatively from younger subjects in setting stricter criteria for more nameable tunes. Distinguishing different sources of global familiarity is a factor in tune recognition, and the data suggest that this type of source monitoring is impaired in AD and involves different strategies in younger and older adults.
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Ultrasmall superparamagnetic iron oxide (USPIO) particles are promising contrast media, especially for molecular and cellular imaging besides lymph node staging owing to their superior NMR efficacy, macrophage uptake and lymphotropic properties. The goal of the present prospective clinical work was to validate quantification of signal decrease on high-resolution T(2)-weighted MR sequences before and 24-36 h after USPIO administration for accurate differentiation between benign and malignant normal-sized pelvic lymph nodes. Fifty-eight patients with bladder or prostate cancer were examined on a 3 T MR unit and their respective lymph node signal intensities (SI), signal-to-noise (SNR) and contrast-to-noise (CNR) were determined on pre- and post-contrast 3D T(2)-weighted turbo spin echo (TSE) images. Based on histology and/or localization, USPIO-uptake-related SI/SNR decrease of benign vs malignant and pelvic vs inguinal lymph nodes was compared. Out of 2182 resected lymph nodes 366 were selected for MRI post-processing. Benign pelvic lymph nodes showed a significantly higher SI/SNR decrease compared with malignant nodes (p < 0.0001). Inguinal lymph nodes in comparison to pelvic lymph nodes presented a reduced SI/SNR decrease (p < 0.0001). CNR did not differ significantly between benign and malignant lymph nodes. The receiver operating curve analysis yielded an area under the curve of 0.96, and the point with optimal accuracy was found at a threshold value of 13.5% SNR decrease. Overlap of SI and SNR changes between benign and malignant lymph nodes were attributed to partial voluming, lipomatosis, histiocytosis or focal lymphoreticular hyperplasia. USPIO-enhanced MRI improves the diagnostic ability of lymph node staging in normal-sized lymph nodes, although some overlap of SI/SNR-changes remained. Quantification of USPIO-dependent SNR decrease will enable the validation of this promising technique with the final goal of improving and individualizing patient care.
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To enhance understanding of the metabolic indicators of type 2 diabetes mellitus (T2DM) disease pathogenesis and progression, the urinary metabolomes of well characterized rhesus macaques (normal or spontaneously and naturally diabetic) were examined. High-resolution ultra-performance liquid chromatography coupled with the accurate mass determination of time-of-flight mass spectrometry was used to analyze spot urine samples from normal (n = 10) and T2DM (n = 11) male monkeys. The machine-learning algorithm random forests classified urine samples as either from normal or T2DM monkeys. The metabolites important for developing the classifier were further examined for their biological significance. Random forests models had a misclassification error of less than 5%. Metabolites were identified based on accurate masses (<10 ppm) and confirmed by tandem mass spectrometry of authentic compounds. Urinary compounds significantly increased (p < 0.05) in the T2DM when compared with the normal group included glycine betaine (9-fold), citric acid (2.8-fold), kynurenic acid (1.8-fold), glucose (68-fold), and pipecolic acid (6.5-fold). When compared with the conventional definition of T2DM, the metabolites were also useful in defining the T2DM condition, and the urinary elevations in glycine betaine and pipecolic acid (as well as proline) indicated defective re-absorption in the kidney proximal tubules by SLC6A20, a Na(+)-dependent transporter. The mRNA levels of SLC6A20 were significantly reduced in the kidneys of monkeys with T2DM. These observations were validated in the db/db mouse model of T2DM. This study provides convincing evidence of the power of metabolomics for identifying functional changes at many levels in the omics pipeline.
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This study aimed to measure serum concentrations of five lectin-pathway components, mannan-binding lectin (MBL), M-ficolin, L-ficolin, H-ficolin, and MBL-associated serine protease-2 (MASP-2), in healthy neonates and children, to determine if they change with age and to compare them with serum concentrations in healthy adults. Concentrations were measured in 141 preterm and 30 term neonates, in 120 children including infants and adolescents, and in 350 adults (97 for L-ficolin) by inhouse time-resolved immunofluorometric assays or commercially available enzyme-linked immunosorbent assays. The adjacent categories method applying Wilcoxon-Mann-Whitney tests was used to determine age categories where concentrations differed significantly. Displaying serum concentration vs. age, an inverted-U shape (higher concentrations in children than in neonates and adults) was found for MBL and the ficolins, and an S-shape for MASP-2. Serum concentrations of all five lectin-pathway components were significantly lower in preterm neonates <32-wk gestational age compared to older neonates, infants, and children. Only M-ficolin in children >1 yr and H-ficolin in term neonates and in children were found to be comparable with adult values. MBL, M-, L-, and H-ficolin, and MASP-2 serum concentrations show important changes with age. The respective normal ranges for adults should not be used in the pediatric population. The age-specific pediatric ranges established here may be used instead.