julilili42/papers huggingface dataset:
Cortical Control of Visually Guided Reaching: Evidence from Patients with Optic Ataxia
2005-02-16

The dorsal stream of visual information processing connecting V1 to the parietal cortex is thought to provide a fast control of visually guided reaching. Important for this assumption was the observation that in both the monkey and the human, parietal lesions may provoke disturbance of visually goal-directed hand movements. In the human, severe misreaching termed 'optic ataxia' has been ascribed to lesions of the superior parietal lobule (SPL) and/or the intraparietal sulcus. Using new tools for lesion analysis, here we re-evaluated this view investigating the typical lesion location in a large group of unilateral stroke patients with optic ataxia, collected over a time period of 15 years. We found no evidence for the assumption that disruption of visually guided reaching in humans is associated with a lesion typically centering on the SPL on the convexity. In both left and right hemispheres, we found optic ataxia associated with a lesion overlap that affected the lateral cortical convexity at the occipito-parietal junction, i.e. the junction between the inferior parietal lobule (IPL) and superior occipital cortex and--in the left hemisphere even more posteriorly--also the junction between occipital cortex and the SPL. Via the underlying parietal white matter, the lesion overlap extended in both hemispheres to the medial cortical aspect, where it affected the precuneus close to the occipito-parietal junction. These lateral and medial structures seem to be integral to the fast control of visually guided reaching in humans.
Ectopic Norrin Induces Growth of Ocular Capillaries and Restores Normal Retinal Angiogenesis in Norrie Disease Mutant Mice
2005-02-16

Norrie disease is an X-linked retinal dysplasia that presents with congenital blindness, sensorineural deafness, and mental retardation. Norrin, the protein product of the Norrie disease gene ( NDP ), is a secreted protein of unknown biochemical function. Norrie disease ( Ndp y/ - ) mutant mice that are deficient in norrin develop blindness, show a distinct failure in retinal angiogenesis, and completely lack the deep capillary layers of the retina. We show here that the transgenic expression of ectopic norrin under control of a lens-specific promoter restores the formation of a normal retinal vascular network in Ndp y/ - mutant mice. The improvement in structure correlates with restoration of neuronal function in the retina. In addition, lenses of transgenic mice with ectopic expression of norrin show significantly more capillaries in the hyaloid vasculature that surrounds the lens during development. In vitro , lenses of transgenic mice in coculture with microvascular endothelial cells induce proliferation of the cells. Transgenic mice with ectopic expression of norrin show more bromodeoxyuridine-labeled retinal progenitor cells at embryonic day 14.5 and thicker retinas at postnatal life than wild-type littermates, indicating a putative direct neurotrophic effect of norrin. These data provide direct evidence that norrin induces growth of ocular capillaries and that pharmacologic modulation of norrin might be used for treatment of the vascular abnormalities associated with Norrie disease or other vascular disorders of the retina.
Incidence and diagnosis of anosognosia for hemiparesis revisited
2005-02-16

Patients who do not mention their paresis spontaneously but do so when questioned about it directly should not be diagnosed having "anosognosia." If this more conservative cut off criterion is applied to the data of the present as well as previous studies, a frequency of between 10% and 18% for anosognosia for hemiparesis is obtained in unselected samples of acute hemiparetic stroke patients. The incidence thus seems smaller than previously assumed.
Clinical and Parasitological Characteristics of Puerperal Malaria
2005-02-16

Compared with nonpregnant women, puerperal women have a considerably increased risk for the development of malaria and/or parasitemia. This increased risk is caused both by the recurrence of P. falciparum parasitemia and by the increased susceptibility to new infections, although the latter plays a more significant role.
Non‐invasive phakometric measurement of corneal and crystalline lens alignment in human eyes
2005-02-16

Abstract We describe a non‐invasive phakometric method for determining corneal axis rotation relative to the visual axis ( β ) together with crystalline lens axis tilt ( α ) and decentration ( d ) relative to the corneal axis. This does not require corneal contact A‐scan ultrasonography for the measurement of intraocular surface separations. Theoretical inherent errors of the method, evaluated by ray tracing through schematic eyes incorporating the full range of human ocular component variations, were found to be larger than the measurement errors ( β &lt; 0.67°, α &lt; 0.72° and d &lt; 0.08 mm) observed in nine human eyes with known ocular component dimensions. Intersubject variations (mean ± S.D.: β = 6.2 ± 3.4° temporal, α = 0.2 ± 1.8° temporal and d = 0.1 ± 0.1 mm temporal) and repeatability (1.96 × S.D. of difference between repeat readings: β ± 2.0°, α ± 1.8° and d ± 0.2 mm) were studied by measuring the left eyes of 45 subjects (aged 18–42 years, 29 females and 16 males, 15 Caucasians, 29 Indian Asians, one African, refractive error range −7.25 to +1.25 D mean spherical equivalent) on two occasions.
Low frequency of mutations in the X gene, core promoter and precore region of hepatitis B virus infected Vietnamese
2005-02-17

Summary. Numerous mutations in the hepatitis B virus (HBV) genome have been described, but in most cases their role in the pathogenesis of HBV infection is still unclear. Therefore, we analysed specific mutations in HBV‐infected Vietnamese patients and assessed their potential relationship with their clinical outcome. A total of 153 HBV‐infected Vietnamese patients with well‐characterised clinical profiles were enrolled. None of the study participants had a history of alcohol or drug use and none received any antiviral or immunosuppressive therapy before or during the course of this study. The HBx‐ and core promoter regions were analysed by sequencing. The majority of isolates corresponded to genotype A. The presence of hepatitis B e antigen (HBeAg) was associated with significantly higher viral loads in the chronic HBV‐infection group ( P = 0.026). Double mutations in the core promoter (1762/1764) were more frequent in those with cancer than in noncancer patients ( P &lt; 0.01). Mutations at nucleotide (nt) 1766/1773 were found at low prevalence but with no obvious association to clinical presentation. Cytosine at nt 1858 was predominant but the stop codon mutation in the precore region was not detected. In the study, 4/48 hepatocellular carcinoma (HCC) patients revealed truncated HBx, whilst the serine to alanine mutation (codon 31) of HBx was more prevalent in cancer patients than in asymptomatic HBV carriers ( P &lt; 0.01). Thus, the low frequency of mutations indicates the relation of the absence of antiviral pressure in this population. The exclusively found prevalence of certain mutations detected in those with HBV‐related carcinoma nevertheless indicates a degree of association with disease progression.
Hypoxia sensitizes human malignant glioma cells towards CD95L‐induced cell death
2005-02-17

Abstract Death ligands such as CD95 ligand (CD95L) have limited activity against glioma cells under normoxic conditions. Hypoxia is a critical aspect of the microenvironment of gliomas in vivo . We investigated the effect of co‐exposure to acute hypoxia and CD95 ligand in three human malignant glioma cell lines with different susceptibility to CD95L under normoxic conditions. Hypoxia sensitized all three cell lines towards CD95L‐induced cell death. Co‐exposure resulted in apoptotic changes in the early phase, with gradual conversion to secondary necrosis with increasing length of hypoxia. The mitochondrial injury induced by hypoxia was enhanced by co‐treatment, and caspase cleavage became prominent. Inhibition of the epidermal growth factor receptor (EGFR), although sensitizing glioma cells to CD95L under normoxia, protects glioma cells from hypoxia by reducing energy consumption. However, the opposing effects of EGFR signalling on death induced by CD95L or hypoxia were neutralized by co‐exposure to hypoxia and CD95L. Furthermore, inhibition of protein synthesis by cycloheximide also reduced glucose consumption and conferred protection from hypoxia, but did not modulate CD95L‐induced cell death under hypoxic conditions. These results suggest that death ligands may be useful to target hypoxic tumour cells resistant to conventional therapies or to complement strategies aiming at the induction of tumour hypoxia.
Towards Quantum Logic with Cold Atoms in a CO 2 Laser Optical Lattice
2005-02-17

This chapter contains sections titled: Introduction Entanglement and Beyond Quantum Logic and Far-detuned Optical Lattices Resolving and Addressing Cold Atoms in Single Lattice Sites Recent Work References
The Arabidopsis Plastidic Glucose 6-Phosphate/Phosphate Translocator GPT1 Is Essential for Pollen Maturation and Embryo Sac Development
2005-02-18

Plastids of nongreen tissues can import carbon in the form of glucose 6-phosphate via the glucose 6-phosphate/phosphate translocator (GPT). The Arabidopsis thaliana genome contains two homologous GPT genes, AtGPT1 and AtGPT2. Both proteins show glucose 6-phosphate translocator activity after reconstitution in liposomes, and each of them can rescue the low-starch leaf phenotype of the pgi1 mutant (which lacks plastid phosphoglucoisomerase), indicating that the two proteins are also functional in planta. AtGPT1 transcripts are ubiquitously expressed during plant development, with highest expression in stamens, whereas AtGPT2 expression is restricted to a few tissues, including senescing leaves. Disruption of GPT2 has no obvious effect on growth and development under greenhouse conditions, whereas the mutations gpt1-1 and gpt1-2 are lethal. In both gpt1 lines, distorted segregation ratios, reduced efficiency of transmission in males and females, and inability to complete pollen and ovule development were observed, indicating profound defects in gametogenesis. Embryo sac development is arrested in the gpt1 mutants at a stage before the fusion of the polar nuclei. Mutant pollen development is associated with reduced formation of lipid bodies and small vesicles and the disappearance of dispersed vacuoles, which results in disintegration of the pollen structure. Taken together, our results indicate that GPT1-mediated import of glucose 6-phosphate into nongreen plastids is crucial for gametophyte development. We suggest that loss of GPT1 function results in disruption of the oxidative pentose phosphate cycle, which in turn affects fatty acid biosynthesis.
A comparison of Monte Carlo dose calculation denoising techniques
2005-02-18

Recent studies have demonstrated that Monte Carlo (MC) denoising techniques can reduce MC radiotherapy dose computation time significantly by preferentially eliminating statistical fluctuations ('noise') through smoothing. In this study, we compare new and previously published approaches to MC denoising, including 3D wavelet threshold denoising with sub-band adaptive thresholding, content adaptive mean-median-hybrid (CAMH) filtering, locally adaptive Savitzky-Golay curve-fitting (LASG), anisotropic diffusion (AD) and an iterative reduction of noise (IRON) method formulated as an optimization problem. Several challenging phantom and computed-tomography-based MC dose distributions with varying levels of noise formed the test set. Denoising effectiveness was measured in three ways: by improvements in the mean-square-error (MSE) with respect to a reference (low noise) dose distribution; by the maximum difference from the reference distribution and by the 'Van Dyk' pass/fail criteria of either adequate agreement with the reference image in low-gradient regions (within 2% in our case) or, in high-gradient regions, a distance-to-agreement-within-2% of less than 2 mm. Results varied significantly based on the dose test case: greater reductions in MSE were observed for the relatively smoother phantom-based dose distribution (up to a factor of 16 for the LASG algorithm); smaller reductions were seen for an intensity modulated radiation therapy (IMRT) head and neck case (typically, factors of 2-4). Although several algorithms reduced statistical noise for all test geometries, the LASG method had the best MSE reduction for three of the four test geometries, and performed the best for the Van Dyk criteria. However, the wavelet thresholding method performed better for the head and neck IMRT geometry and also decreased the maximum error more effectively than LASG. In almost all cases, the evaluated methods provided acceleration of MC results towards statistically more accurate results.
Analysis of the mKir2.1 channel activity in potassium influx defective Saccharomyces cerevisiae strains determined as changes in growth characteristics
2005-02-19

Potassium uptake defective Saccharomyces cerevisiae strains (Δ trk1,2 and Δ trk1,2 Δ tok1 ) were used for the phenotypic analysis of the mouse inward rectifying Kir2.1 channel by growth analysis. Functional expression of both, multi‐copy plasmid and chromosomally expressed GFP‐mKir2.1 fusion constructs complemented the potassium uptake deficient phenotype in a pH out dependent manner. Upon application of Hygromycin B to chromosomally mKir2.1 expressing cells, significantly lower toxin sensitivity (EC 50 15.4 μM) compared to Δ trk1,2 Δ tok1 cells (EC 50 2.6 μM) was observed. Growth determination of mKir2.1 expressing strains upon application of Ag + , Cs + and Ba 2+ as known blockers of mKir2.1 channels revealed significantly decreased channel function. Cells with mKir2.1 were about double sensitive to AgNO 3 , 350‐fold more sensitive to CsCl and 1500‐fold more sensitive to BaCl 2 in comparison to the respective controls indicating functional expression and correct pharmacology.
3-(1H-Indol-3-yl)-4-(3,4,5-trimethoxyphenyl)-2,5-dihydro-1H-pyrrole-2,5-dione
2005-02-19

The crystal structure of the title compound, C21H18N2O5, was determined in order to study the electrocyclic reactivity of 3,4-diaryl-1H-pyrrole-2,5-dione derivatives. Intermolecular hydrogen bonds form sheets.
5,6,7-Trimethoxy-2,3-dihydro-1H,8H-benzo[a]pyrrolo[3,4-c]carbazole-1,3-dione dimethyl sulfoxide solvate
2005-02-19

The crystal structure of the title compound, C21H16N2O5·C2H6OS, was determined to investigate the electrocyclic reactivity of 3,4-diaryl-1H-pyrrole-2,5-diones (3,4-bisarylmaleimides) to the yield corresponding carbazole derivatives.
Low‐grade primary central nervous system lymphoma in immunocompetent patients
2005-02-21

Summary Primary central nervous system lymphomas (PCNSL) are usually diffuse large B‐cell non‐Hodgkin's lymphomas (NHL). Here we characterize the clinical presentation, course and outcome of patients with low‐grade PCNSL. Records of 332 patients screened for inclusion in three multicentre prospective trials were reviewed. Ten patients (3%) with a median age of 59 years and a median Karnofsky performance status of 70% were identified. Seven patients had B‐cell and three had T‐cell lymphoma. The median growth fraction was 4%. The radiological morphology was unusual for PCNSL in eight patients. Three patients underwent complete tumour resection, combined with chemotherapy in one patient and with chemotherapy plus local radiotherapy in another. Four patients received chemotherapy and three received chemotherapy plus whole‐brain irradiation, resulting in four complete remissions, two no‐change situations and one progressive disease. Patients had an overall survival (OAS) of 2–58+ months with a 2‐year OAS of 67%. Low‐grade PCNSL may differ from classical high‐grade PCNSL in its clinical features and radiological morphology. The clinical course may be variable and frequently more indolent than in classical PCNSL.
Synthesis and Structure of the New Compound La2O(CN2)2 Possessing an Interchanged Anion Proportion Compared to the Parent La2O2(CN2). Synthese und Kristallstruktur der neuen Verbindung La2O(CN2)2 mit einem vertauschten Anionenverhältnis gegenüber der Bezugsverbindung La2O2(CN2)
2005-02-21

Abstract La 2 O(CN 2 ) 2 was synthesized from a 1:1:2 molar reaction mixture of LaCl 3 , LaOCl, and Li 2 (CN 2 ) at 650 °C. Well developed single crystals were grown from a LiCl‐KCl flux. The crystal structure was refined as monoclinic (space group C 2/ c , Z = 2, a = 13.530(2) Å, b = 6.250(1) Å, c = 6.1017(9) Å, β = 104.81(2)°) from single crystal X‐ray diffraction data. The La 3+ and (CN 2 ) 2— ions in the crystal structure of La 2 O(CN 2 ) 2 can be compared to Fe 3+ and S 2 2— ions in the cubic pyrite structure, being arranged like in a distorted NaCl type structure with their centers of gravity. In addition, the O 2— ions in La 2 O(CN 2 ) 2 are occupying 1/4 of the tetrahedral voids formed by the arrangement of metal ions.
Activation of Hypoxia-Inducible Factor-1 in Bacillary Angiomatosis
2005-02-22

Background— Bartonella species are the only known bacterial pathogens causing vasculoproliferative disorders in humans (bacillary angiomatosis [BA]). Cellular and bacterial pathogenetic mechanisms underlying the induction of BA are largely unknown. Methods and Results— Activation of hypoxia-inducible factor-1 (HIF-1), the key transcription factor involved in angiogenesis, was detected in Bartonella henselae –infected host cells in vitro by immunofluorescence, Western blotting, electrophoretic mobility shift, and reporter gene assays and by immunohistochemistry in BA tissue lesions in vivo. Gene microarray analysis revealed that a B henselae infection resulted in the activation of genes typical for the cellular response to hypoxia. HIF-1 was essential for B henselae –induced expression of vascular endothelial growth factor as shown by inhibition with the use of HIF-1–specific short-interfering RNA. Moreover, infection with B henselae resulted in increased oxygen consumption, cellular hypoxia, and decreased ATP levels in host cells. Infection with a pilus-negative variant of B henselae did not lead to cellular hypoxia or activation of HIF-1 or vascular endothelial growth factor secretion, suggesting a crucial role of this bacterial surface protein in the angiogenic reprogramming of the host cells. Conclusions— B henselae induces a proangiogenic host cell response via HIF-1. Our data provide for the first time evidence that HIF-1 may play a role in bacterial infections.
Discovery of magnetic fields in central stars of planetary nebulae
2005-02-22

\\n For the first time we have directly detected magnetic fields in central stars of\\nplanetary nebulae by means of spectro-polarimetry with FORS1 at the VLT. In all four objects of our sample\\nwe found kilogauss magnetic fields, in NGC 1360 and LSS 1362 with very high significance, while\\nin EGB 5 and Abell 36 the existence of a magnetic field is probable but with less certainty.\\nThis discovery supports the hypothesis that the non-spherical symmetry of most\\nplanetary nebulae is caused by magnetic fields in AGB stars. Our high discovery rate demands mechanisms to prevent full conservation of magnetic flux\\nduring the transition to white dwarfs. \\n \\n
Primary stability of various forms of osteosynthesis in the treatment of fractures of the proximal tibia
2005-02-22

The treatment of fractures of the proximal tibia is complex and makes great demands on the implants used. Our study aimed to identify what levels of primary stability could be achieved with various forms of osteosynthesis in the treatment of diaphyseal fractures of the proximal tibia. Pairs of human tibiae were investigated. An unstable fracture was simulated by creating a defect at the metaphyseal-diaphyseal junction. Six implants were tested in a uniaxial testing device (Instron) using the quasi-static and displacement-controlled modes and the force-displacement curve was recorded. The movements of each fragment and of the implant were recorded video-optically (MacReflex, Qualysis). Axial deviations were evaluated at 300 N. The results show that the nailing systems tolerated the highest forces. The lowest axial deviations in varus and valgus were also found for the nailing systems; the highest axial deviations were recorded for the buttress plate and the less invasive stabilising system (LISS). In terms of rotational displacement the LISS was better than the buttress plate. In summary, it was found that higher loads were better tolerated by centrally placed load carriers than by eccentrically placed ones. In the case of the latter, it appears advantageous to use additive procedures for medial buttressing in the early phase.
Simocyclinone D8, an Inhibitor of DNA Gyrase with a Novel Mode of Action
2005-02-23

ABSTRACT We have characterized the interaction of a new class of antibiotics, simocyclinones, with bacterial DNA gyrase. Even though their structures include an aminocoumarin moiety, a key feature of novobiocin, coumermycin A 1 , and clorobiocin, which also target gyrase, simocyclinones behave strikingly differently from these compounds. Simocyclinone D8 is a potent inhibitor of gyrase supercoiling, with a 50% inhibitory concentration lower than that of novobiocin. However, it does not competitively inhibit the DNA-independent ATPase reaction of GyrB, which is characteristic of other aminocoumarins. Simocyclinone D8 also inhibits DNA relaxation by gyrase but does not stimulate cleavage complex formation, unlike quinolones, the other major class of gyrase inhibitors; instead, it abrogates both Ca 2+ - and quinolone-induced cleavage complex formation. Binding studies suggest that simocyclinone D8 interacts with the N-terminal domain of GyrA. Taken together, our results demonstrate that simocyclinones inhibit an early step of the gyrase catalytic cycle by preventing binding of the enzyme to DNA. This is a novel mechanism for a gyrase inhibitor and presents new possibilities for antibacterial drug development.
Biofilm Formation, icaADBC Transcription, and Polysaccharide Intercellular Adhesin Synthesis by Staphylococci in a Device-Related Infection Model
2005-02-24

ABSTRACT Biofilm formation of Staphylococcus epidermidis and S. aureus is mediated by the polysaccharide intercellular adhesin (PIA) encoded by the ica operon. We used a device-related animal model to investigate biofilm formation, PIA expression (immunofluorescence), and ica transcription (quantitative transcript analysis) throughout the course of infection by using two prototypic S. aureus strains and one S. epidermidis strain as well as corresponding ica mutants. During infection, the ica mutants were growth attenuated when inoculated in competition with the corresponding wild-type strains but not when grown singly. A typical biofilm was observed at the late course of infection. Only in S. aureus RN6390, not in S. aureus Newman, were PIA and ica- specific transcripts detectable after anaerobic growth in vitro. However, both S. aureus strains were PIA positive in vivo by day 8 of infection. ica transcription preceded PIA expression and biofilm formation in vivo. In S. epidermidis , both PIA and ica expression levels were elevated compared to those in the S. aureus strains in vitro as well as in vivo and were detectable throughout the course of infection. In conclusion, in S. aureus , PIA expression is dependent on the genetic background of the strain as well as on strong inducing conditions, such as those dominating in vivo. In S. epidermidis , PIA expression is elevated and less vulnerable to environmental conditions.