julilili42/papers huggingface dataset:
Multislice first‐pass myocardial perfusion imaging: Comparison of saturation recovery (SR)‐TrueFISP‐two‐dimensional (2D) and SR‐TurboFLASH‐2D pulse sequences
2004-04-21

Abstract Purpose To compare signal‐to‐noise ratio (SNR), contrast‐to‐noise (CNR) ratio, and diagnostic accuracy of a newly developed saturation recovery (SR)‐TrueFISP‐two‐dimensional (2D) sequence with an SR‐TurboFLASH‐2D sequence. Materials and Methods In seven healthy subjects and nine patients with coronary artery disease (CAD), contrast‐enhanced perfusion imaging (with Gd‐DTPA) was performed with SR‐TrueFISP and SR‐TurboFLASH sequences. Hypoperfused areas were assessed qualitatively (scale = 0–4). Furthermore, SNR and CNR were calculated and semiquantitative perfusion parameters were determined from signal intensity (SI) time curves. Standard of reference for patient studies was single‐photon emission computer tomography (SPECT) and angiography. Results The perception of perfusion deficits was superior in TrueFISP images (2.6 ± 1.0) than in TurboFLASH (1.4 ± 0.6) ( P &lt; 0.001). Phantom measurements yielded increased SNR (143 ± 34%) and CNR (158 ± 64%) values for TrueFISP. In patient/volunteer studies SNR was 61% to 100% higher and signal enhancement was 110% to 115% higher with TrueFISP than with TurboFLASH. Qualitative and semiquantitative assessment of perfusion defects yielded higher sensitivities for detection of perfusion defects with TrueFISP (68% to 78%) than with TurboFLASH (44% to 59%). Conclusion SR‐TrueFISP‐2D perfusion imaging provides superior SNR and CNR than TurboFLASH imaging. Moreover, the dynamic range of SIs was found to be higher with TrueFISP, resulting in an increased sensitivity for detection of perfusion defects. J. Magn. Reson. Imaging 2004;19:555–563. © 2004 Wiley‐Liss, Inc.
Phagosomal Acidification Is Not a Prerequisite for Intracellular Multiplication ofLegionella pneumophilain Human Monocytes
2004-04-21

Legionella pneumophila is able to multiply in a variety of eukaryotic cells. Contradictory results have been published on the significance of phagosomal acidification in the intracellular multiplication of Legionella species in monocytes. Therefore, we analyzed the phagosomal pH values in 2 different types of human monocytes throughout the intracellular-replication cycles of 2 Legionella species that have different rates of intracellular multiplication. Our results show that phagosomal acidification is not a prerequisite for intracellular replication of Legionella pneumophila in human monocytes.
Therapy of meningeal melanocytomas
2004-04-23

Abstract BACKGROUND Meningeal melanocytomas are rare, benign central nervous system lesions with a high probability of recurrence. To the authors' knowledge, approximately 100 cases have been reported since 1972, when the entity first was described. In the current study, four therapies were compared with regard to local control and survival to identify which is best. METHODS All reported cases were reviewed with regard to extent of resection, radiotherapy, local control, and survival. If published data were incomplete, the authors were contacted for additional data. Patients were categorized by therapy: complete resection (CTR), complete resection followed by radiotherapy (CTR‐RT), incomplete resection (ITR), and incomplete resection followed by radiotherapy (ITR‐RT). Local control and survival were calculated using the Kaplan–Meier method. A multivariate analysis was performed including age, gender, tumor location, confirmation of extent of resection, and treatment schedule. RESULTS A total of 89 patients were included: 46 with CTR, 3 with CTR‐RT, 23 with ITR, and 17 with ITR‐RT. The 5‐year local control rate was 80% after CTR, 100% after CTR‐RT, and 72% after ITR‐RT versus 18% after ITR ( P &lt; 0.001). The 5‐year survival rate was 100% after CTR, CTR‐RT, and ITR‐RT, respectively, versus 46% after ITR ( P &lt; 0.001). Multivariate analysis demonstrated that therapy was the only variable that affected local control and survival significantly. In 14 patients treated with ITR‐RT, RT was restricted to the tumor region. The radiation dose was 30–40 grays (Gy) in 6 patients, 45–55 Gy in 7 patients, and unknown in 1 patient. The 5‐year local control rate was 86% after a dose of 45–55 Gy versus 27% after a dose of 30–40 Gy ( P = 0.1). CONCLUSIONS CTR was found to be significantly superior to ITR with regard to both local control and survival. Outcome was significantly improved by RT after ITR. Doses of 45–55 Gy appeared to be more beneficial than doses of ≤ 40 Gy. Cancer 2004. © 2004 American Cancer Society.
Serum protein profiling by SELDI mass spectrometry: detection of multiple variants of serum amyloid alpha in renal cancer patients
2004-04-26

The molecular analysis of serum is an important field for the definition of potential diagnostic markers or disease-related protein alterations. Novel proteomic technologies such as the mass spectrometric-based surface-enhanced laser desorption/ionization (SELDI) ProteinChip technique facilitate a rapid and reproducible analysis of such protein mixtures and affords the researcher a new dimension in the search for biomarkers of disease. Here, we have applied this technology to the study of a cohort of serum samples from well-characterized renal cell carcinoma patients for the identification of such proteins by comparison to healthy controls. We detected and characterized haptoglobin 1 alpha and serum amyloid alpha-1 (SAA-1) as disease related, in addition to an as-yet-unidentified marker of 10.84 kDa. Of particular note is the detection of multiple variants of SAA-1 in multiplex that have not been described in the sera of cancer patients. SAA-1 is detected as full-length protein, des-Arginine and des-Arginine/des-Serine variants at the N terminus by SELDI. In addition, we could also detect a low-abundant variant minus the first five N-terminal amino acids. Such variants may impact the function of the protein. We conclude the technique to be a reproducible, fast and simple mode for the discovery and analysis of marker proteins of disease in serum.
Variations in the serum concentrations of soluble Fas and soluble Fas ligand in Vietnamese patients infected with hepatitis B virus
2004-04-26

Abstract Earlier studies of both chronic hepatitis B and C virus (HBV and HCV) patients have shown a strong correlation between the soluble membrane Fas (sFas) and Fas protein expression on hepatocytes. The serum concentrations of sFas and soluble Fas ligand (sFasL) was examined in both healthy and HBV‐infected Vietnamese patients to determine their relationship with the outcome of HBV infection. Patients with chronic rather than acute HBV had significantly higher amounts of sFas and sFasL, whilst the highest concentrations of both molecules were detected in those with malignant forms of HBV infection. sFas and sFasL concentrations tended to increase with a profile that paralleled the progression from asymptomatic to acute through chronic to malignant states, most markedly in the case of sFas. The sFas:sFasL ratio highlighted the relative predominance of sFas in those with acute and chronic HBV compared with asymptomatic or severe forms. In patients with hepatocellular carcinoma (HCC) a significant correlation was also observed between sFasL and alpha‐feto protein (AFP) levels. The results indicate that sFas and to a lesser extent sFasL levels are to some degree associated with clinical progression in HBV infection. J. Med. Virol. 73:244–249, 2004. © 2004 Wiley‐Liss, Inc.
The Anatomy of Spatial Neglect based on Voxelwise Statistical Analysis: A Study of 140 Patients
2004-04-27

A major challenge for any anatomical study of spatial neglect in neurological patients is that human lesions vary tremendously in extent and location between individuals. Approaches to this problem used in previous studies were to focus on subgroups of patients that are more homogeneous either with respect to the branch territory affected by the stroke or with respect to existing additional neurological symptoms (e.g. additional visual field defects). It could be argued that such strategies might bias the conclusions on the critical substrate associated with spatial neglect. The present study thus addressed the high variability inherent in naturally occurring lesions by using an unselected, but very large sample size and by comparing a neglect group with a non-neglect group using voxelwise statistical testing. We investigated an unselected 7 year sample of 140 consecutively admitted patients with right hemisphere strokes. Seventy-eight had spatial neglect, 62 did not show the disorder. The incidence of visual field defects was comparable in both groups. For assessing lesion location, in a first step, we used conventional lesion density plots together with subtraction analysis. Moreover, due to the large size of the sample voxelwise statistical testing was possible to objectively estimate which brain regions are more frequently compromised in neglect patients relative to patients without neglect. The results demonstrate that the right superior temporal cortex, the insula and subcortically putamen and caudate nucleus are the neural structures damaged significantly more often in patients with spatial neglect.
Mutasynthesis of Glycopeptide Antibiotics:  Variations of Vancomycin's AB-Ring Amino Acid 3,5-Dihydroxyphenylglycine
2004-04-27

In the mutasynthetic approach, the DeltadpgA mutant of the vancomycin-type glycopeptide antibiotic producer Amycolatopsis balhimycina, which is deficient in the synthesis of 3,5-dihydroxyphenylglycine (DPg), was supplemented with synthetic DPg analogues to obtain the corresponding modified glycopeptides. Sterically more demanding 3,5-disubstituted methoxy derivatives as well as monosubstituted DPg analogues were accepted as substrates. These facts indicate that steric and electronic requirements suffice in several cases for the oxidative closure of the AB ring, thus leading to the generation of novel antibiotically active glycopeptide derivatives. The results represent a further step in evaluating the potential of mutasynthesis for peptidic secondary metabolites.
Retinal Colocalization and In Vitro Interaction of the Glutamate Receptor EAAT3 and the Serum- and Glucocorticoid-Inducible Kinase SGK1
2004-04-27

SGK1 and EAAT3 are coexpressed in retinal neurons, and SGK1 serves to stimulate EAAT3. This function is shared by protein kinase B (PKB). The experiments reveal a novel mechanism regulating EAAT3, which may be essential for the function of the retinal ganglion cells.
Collective atomic recoil lasing including friction and diffusion effects
2004-04-27

We extend the Collective Atomic Recoil Lasing (CARL) model including the\\neffects of friction and diffusion forces acting on the atoms due to the\\npresence of optical molasses fields. The results from this model are consistent\\nwith those from a recent experiment by Kruse et al. [Phys. Rev. Lett. 91,\\n183601 (2003)]. In particular, we obtain a threshold condition above which\\ncollective backscattering occurs. Using a nonlinear analysis we show that the\\nbackscattered field and the bunching evolve to a steady-state, in contrast to\\nthe non-stationary behaviour of the standard CARL model. For a proper choice of\\nthe parameters, this steady-state can be superfluorescent.\\n
Abyssomicin C—A Polycyclic Antibiotic from a Marine Verrucosispora Strain as an Inhibitor of the p‐Aminobenzoic Acid/Tetrahydrofolate Biosynthesis Pathway
2004-04-28

Plumbing the depths: Abyssomicin C (structure shown) from ocean floor sediment is a novel antibiotic that inhibits the biosynthesis steps between chorismate and p-aminobenzoic acid. Its activity may be explained by the irreversible trapping of the targeted enzymes by a Michael addition. Blocking the biosynthesis of p-aminobenzoic acid may be one approach to developing new antibiotics.
Neural Correlates of Cat Odor-Induced Anxiety in Rats: Region-Specific Effects of the Benzodiazepine Midazolam
2004-04-28

Cat odor elicits a profound defensive reaction in rats that is reduced by benzodiazepine drugs. The neural correlates of this phenomenon were investigated here using Fos immunohistochemistry. Rats received either midazolam (0.75 mg/kg, s.c.) or vehicle and were exposed to pieces of a collar that had been worn by a domestic cat or an unworn (dummy) collar. Cat odor caused midazolam-sensitive defensive behavioral responses, including avoidance of collar contact, inhibition of grooming, and prolonged rearing. Cat odor exposure induced Fos expression in the posterior accessory olfactory bulb (glomerular, mitral, and granule cell layers), with granule cell layer activation attenuated by midazolam. High basal Fos expression, and some cat odor-associated Fos expression, was evident in the main olfactory bulb (glomerular cell layer), and midazolam exerted a strong inhibitory effect in this region. Midazolam inhibited Fos expression in key limbic regions involved in pheromone transduction (medial amygdala and bed nucleus of the stria terminalis) and defensive behavior (prelimbic cortex, lateral septum, lateral and medial preoptic areas, and dorsal premammillary nucleus). However, midazolam failed to affect cat odor-related Fos expression in a range of key defense-related sites, including the ventromedial hypothalamic nucleus, paraventricular nucleus of the hypothalamus, periaqueductal gray, and cuneiform nucleus. These results indicate that midazolam exerts a region-specific effect on the neural substrates activated by predator odor, with effects in the lateral septum and dorsal premammillary nucleus likely to be of major importance. These findings also suggest the intriguing hypothesis that cat odor is processed by rats as a “pheromone-like” stimulus.
Reply to “Comment on ‘Interaction induced deformation of the momentum distribution of spin polarized nuclear matter’ ”
2004-04-28

A comparison is made between a Brueckner-Hartree-Fock study of spin polarized nuclear matter allowing for deformation of the Fermi spheres and studies of such systems in terms of the Landau parametrization of the effective interaction.
Ligand‐gated channels in early mesencephalic neuronal precursors: immunocytochemical and electrophysiological analysis
2004-04-29

Abstract Neuronal precursors play an important role in potential regenerative therapeutic strategies in different neurodegenerative diseases, e.g. Parkinson's disease. To understand proliferation and differentiation of these cells in vitro and in vivo , it is important to characterize functional properties of neuronal precursors in detail. The aim of the present study was to analyse the electrophysiological characteristics of ligand‐gated channels of neuronal precursors prepared from the rat ventral mesencephalon (VM) of embryonic stage 12.5 during their in vitro differentiation. For the experiments we used the patch‐clamp technique in combination with a system for ultrafast solution exchange and immunocytochemistry. It could be shown that functional active AMPA‐type glutamate as well as GABA A receptor channels are expressed at an early stage of neuronal development. In culture we observed excitatory as well as inhibitory postsynaptic currents (defined by their different kinetics) which correspond to the activation of AMPAergic and GABAergic receptor channels. Two populations of glutamate‐activated currents could be differentiated by their different time course of desensitization whereas the time course of resensitization and deactivation was normally distributed in all cells. GABAergic currents could be blocked by bicuculline and their kinetics correspond to that of GABA A receptor channel currents. Summarizing the results, in the present study it was shown for the first time that neuronal embryonic precursors of the rat VM express both functional AMPA‐type glutamate and functional GABA A receptor channels in vitro .
Cognitive tinnitus sensitization: Behavioral and neurophysiological aspects of tinnitus centralization
2004-04-30

ACT may be associated with a specific learning process allowing increased tinnitus awareness and continuous appraisal. The underlying mechanism, the cognitive tinnitus sensitization process, is associated with a decrease in the tinnitus cognition threshold. The sensitization contributes to the extremely loud cognition of the tinnitus signal. The associated audiological cognitive discrepancy can be used clinically and diagnostically to identify patients for cognitive testing. The sensitization model does not require tinnitus hyperactivity.
Further Characterisation of the 91500 Zircon Crystal
2004-05-01

This paper reports the results from a second characterisation of the 91500 zircon, including data from electron probe microanalysis, laser ablation inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS), secondary ion mass spectrometry (SIMS) and laser fluorination analyses. The focus of this initiative was to establish the suitability of this large single zircon crystal for calibrating in situ analyses of the rare earth elements and oxygen isotopes, as well as to provide working values for key geochemical systems. In addition to extensive testing of the chemical and structural homogeneity of this sample, the occurrence of banding in 91500 in both backscattered electron and cathodoluminescence images is described in detail. Blind intercomparison data reported by both LA‐ICP‐MS and SIMS laboratories indicate that only small systematic differences exist between the data sets provided by these two techniques. Furthermore, the use of NIST SRM 610 glass as the calibrant for SIMS analyses was found to introduce little or no systematic error into the results for zircon. Based on both laser fluorination and SIMS data, zircon 91500 seems to be very well suited for calibrating in situ oxygen isotopic analyses.
Organic molecular beam deposition: Growth studies beyond the first monolayer
2004-05-01

We review recent work on organic molecular beam deposition (OMBD) with emphasis on growth studies beyond the first monolayer, i.e. the evolution of the film structure and morphology. First, we briefly discuss general issues related to growth physics, including epitaxial relations, surface and interface energies, growth modes, correlation functions, dynamic scaling, and growth exponents. We also point out the general features that distinguish organic systems from inorganic systems, such as the different interaction potentials and the internal degrees of freedom of organic molecules. Then we discuss selected case studies, organised according to the role of the substrate (insulators, metals, semiconductors), covering examples from various organic semiconductors, namely perylene-derivatives (in particular diindeno-perylene (DIP) and 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA)), phthalocyanines, and oligoacenes (anthracene, tetracene, pentacene). Finally, we briefly discuss organics-based heterostructures and indicate some open problems and future directions. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Polynomial-time data reduction for dominating set
2004-05-01

Dealing with the NP-complete Dominating Set problem on graphs, we demonstrate the power of data reduction by preprocessing from a theoretical as well as a practical side. In particular, we prove that Dominating Set restricted to planar graphs has a so-called problem kernel of linear size, achieved by two simple and easy-to-implement reduction rules. Moreover, having implemented our reduction rules, first experiments indicate the impressive practical potential of these rules. Thus, this work seems to open up a new and prospective way how to cope with one of the most important problems in graph theory and combinatorial optimization.
Eye movement control during single-word reading in dyslexics
2004-05-01

We investigated whether dyslexics make instantaneous automatic adjustments of reading saccades depending on word length. We used a single-word reading paradigm on 10 dyslexic and 12 normally reading children aged 11-15 years. Eye movements were recorded by scanning laser ophthalmoscope (SLO) while subjects read single words of different length aloud. All subjects passed standardized prescreening tests, which included a reading test, to exclude those with discernible deficits of eyesight, oculomotor skill, or intellectual development. We measured number, direction, frequency, and amplitude of saccades, as well as the durations of inter-saccadic intervals, as functions of word length. The results show that word length influences the number and amplitude of reading saccades in both subject groups, but this relationship showed quantitatively significant group-specific differences: Both groups showed a gradual increase of the saccade amplitudes in either direction dependent on word length, but the gain of this function was significantly lower in the dyslexics. The durations of holding phases between saccades were significantly longer in the dyslexics, and accordingly, we found a lower rate of occurrence of saccades per unit time in the dyslexics. Forward saccade amplitudes showed no correlation with the duration of the preceding or following holding phases in either group. The data show that the mechanisms enabling dyslexics to make instantaneous adjustments of reading saccades depending on word length are present but quantitatively impaired. This supports the view that these adjustments may help dyslexics to increase reading speed, but that they cannot utilize them to the same extent as normal readers.
Regulation of Glucose Transporter SGLT1 by Ubiquitin Ligase Nedd4‐2 and Kinases SGK1, SGK3, and PKB
2004-05-01

Abstract Objectives : Serum‐ and glucocorticoid‐inducible kinase 1 (SGK1) inhibits the ubiquitin ligase neuronal cell expressed developmentally downregulated 4‐2 (Nedd4‐2), which retards the retrieval of the epithelial Na + channel ENaC. Accordingly, SGK1 enhances ENaC abundance in the cell membrane. The significance of this effect is shown by an association of an E8CC/CT;I6CC polymorphism in the SGK1 gene with increased blood pressure. However, strong expression of SGK1 in enterocytes not expressing ENaC points to further functions of SGK1. This study was performed to test for regulation of Na + ‐coupled glucose transporter 1 (SGLT1) by Nedd4‐2, SGK1, and/or the related kinases SGK3 and PKB. Additional studies searched for an association of the SGK1 gene with BMI. Research Methods and Procedures : mRNA encoding SGLT1, wild‐type Nedd4‐2, inactive C938S Nedd4‐2, wild type SGK1, constitutively active S422D SGK1 or inactive K127N SGK1, wild‐type SGK3, and constitutively active T308DS473D PKB or inactive T308AS473A PKB were injected into Xenopus oocytes, and glucose transport was quantified from glucose‐induced current ( I glc ). BMI was determined in individuals with or without the E8CC/CT;I6CC polymorphism. Results: I glc was significantly decreased by coexpression of Nedd4‐2 but not of C938S Nedd4‐2. Coexpression of SGK1, S422D SGK1, SGK3, or T308DS473D PKB, but not of K127N SGK1 or T308AS473A PKB, enhanced I glc and reversed the effect of Nedd4‐2. SGK1 and SGK3 phosphorylated Nedd4‐2. Deletion of the SGK/PKB phosphorylation sites in Nedd4‐2 blunted the kinase effects. BMI was significantly ( p &lt; 0.008) greater in individuals with the E8CC/CT;I6CC polymorphism than in individuals without. Discussion : Overactivity of SGK1 may lead not only to excessive ENaC activity and hypertension but also to enhanced SGLT1 activity and obesity.