julilili42/papers huggingface dataset:
Manual stimulation, but not acute electrical stimulation prior to reconstructive surgery, improves functional recovery after facial nerve injury in rats
2009-01-01

The outcome of peripheral nerve injuries requiring surgical repair is poor. Recent work suggested that electrical stimulation (ES) of the proximal nerve stump to produce repeated discharges of the parent motoneurons for one hour could be a beneficial therapy if delivered immediately prior to reconstructive surgery of mixed peripheral nerves. Purpose: We tested whether ES has a positive influence on functional recovery after repair of a purely motor nerve, the facial nerve. Methods: Electrical stimulation (20 Hz) was delivered to the proximal nerve stump of the transected facial nerve for 1 hour prior to nerve reconstruction by end-to-end suture (facial-facial anastomosis, FFA). For manual stimulation (MS), animals received daily rhythmic stroking of the whisker pads. Restoration of vibrissal motor performance following ES or MS was evaluated using video-based motion analysis. We also assessed the degree of collateral axonal branching at the lesion site, by counting motoneuronal perikarya after triple retrograde labeling, and estimated the quality of motor end-plate reinnervation in the target musculature. Outcomes at 4 months were compared to animals receiving sham stimulation (SS) or MS. Results: Neither protocol reduced the degree of collateral sprouting. ES did not improve functional outcome and failed to reduce the proportion of polyinnervated motor end-plates. By contrast, MS restored normal whisking function and reduced polyinnervation. Conclusion: Whereas acute ES is not beneficial for facial nerve repair, MS provides long-term benefits.
Changes in Cortical Activation during Retrieval of Clock Time Representations in Patients with Mild Cognitive Impairment and Early Alzheimer’s Disease
2009-01-01

&lt;i&gt;Objective:&lt;/i&gt; We investigated healthy controls (HCs), and patients with mild cognitive impairment (MCI) and early Alzheimer’s disease (AD) to identify neuronal correlates of clock time representation and changes resulting from neurodegenerative processes using functional magnetic resonance imaging. &lt;i&gt;Methods:&lt;/i&gt; Two clock-specific tasks demanding conceptual knowledge of clock hands, i.e. a minute hand and an hour hand task, were compared with a semantic control task. &lt;i&gt;Results:&lt;/i&gt; We observed that the minute hand task provoked a stronger activation of areas in the parietal lobes known to be involved in spatial mental imagery, while the semantic task primarily activated regions of the superior temporal lobes associated with verbal conceptual knowledge. The performance of the MCI group did not differ from that of the HC group, but additional activation was found in several brain regions. Decreased activation was detected during the minute hand task in the right middle temporal gyrus. Patients with early AD showed deteriorated performance in both clock tasks along with reduced activation in the occipital lobes and the left fusiform gyrus. Additional activation was detected in the precuneus. &lt;i&gt;Conclusions:&lt;/i&gt; The fusiform gyrus might be crucial for the visual-semantic retrieval of clock time representation. In patients with early AD, access to this visual-semantic knowledge appears to be reduced.
CD52 expression in peripheral T-cell lymphomas determined by combined immunophenotyping using tumor cell specific T-cell receptor antibodies
2009-01-01

For peripheral T-cell lymphomas (PTCL), anti-CD52 (alemtuzumab) therapy is currently under investigation. Previous studies reported widely divergent CD52 expression within PTCL using conventional immunohistochemistry. To accurately discriminate between the presumed mechanistically relevant CD52 expression in tumor versus bystander cells, we employed immunofluorescence double stains using CD52 in combination with an antibody directed against the rearranged T-cell receptor Vbeta-segment of the neoplastic clone in 6 angioimmunoblastic T-cell lymphomas (AITL) and 5 PTCL, unspecified (PTCL-NOS) and, in combination with CD30, in 18 anaplastic large cell lymphomas (ALCL). Tumor cells in all AITL and PTCL-NOS were CD52 positive, while in 17 of 18 ALCL no specific staining was observed. Conversely, the background T- and B-cell infiltrate showed a consistent positivity for CD52. Our approach helps to precisely define CD52 expression in the tumor cell population of PTCL and might therefore be valuable when evaluating the response to alemtuzumab therapy in prospective clinical trials.
APC Sensitive Gastric Acid Secretion
2009-01-01

Adenomatous polyposis coli (APC) is a tumor suppressor gene inactivated in familial adenomatous polyposis and sporadic colorectal cancer. Mice carrying a loss-of-function mutation in the apc gene (apcMin/+) spontaneously develop gastrointestinal tumors. APC fosters degradation of β-catenin, which in turn upregulates the serum- and glucocorticoid-inducible kinase SGK1. SGK1 stimulates KCNQ1, which is required for luminal K+ recycling and thus for gastric acid secretion. BCECF-fluorescence was utilized to determine gastric acid secretion in isolated gastric glands from apcMin/+ mice and their wild type littermates (apc+/+). Western blotting was employed to analyse β-catenin and SGK1 expression and immunohistochemistry to determine KCNQ1 protein abundance. β-catenin and SGK1 expression were enhanced in apcMin/+ mice. Cytosolic pH was similar in apcMin/+ mice and apc+/+ mice. Na+-independent pH recovery following an ammonium pulse (ΔpH/min), which reflects H+/K+ ATPase activity, was, however, significantly faster in apcMin/+ mice than in apc+/+mice. In both genotypes ΔpH/min was abolished in the presence of H+/K+ ATPase inhibitor omeprazole (100 μM). Treatment of apcMin/+ and apc+/+mice with 5 μM forskolin 15 minutes prior to the experiment or increase in local K+-concentrations to 35 mM (replacing Na+/NMDG) significantly increased ΔpH/min and abrogated the differences between genotypes. The increase of ΔpH/min in apcMin/+mice required SGK1, as it was abolished by additional knockout of SGK1 (apcMin/+/sgk1-/-). In conclusion, basal gastric acid secretion is significantly enhanced in apcMin/+mice, pointing to a role of APC in the regulation of gastric acid secretion. The effect of APC requires H+/K+ ATPase activity and is at least partially due to SGK1-dependent upregulation of KCNQ1.
What perturbs isotherms? An assessment using fission-track thermochronology and thermal modelling along the Gotthard transect, Central Alps
2009-01-01

Abstract Interpretation of low-temperature thermochronological data usually relies on assumptions on the shape of isotherms. Recently, a number of thermal modelling approaches investigate and predict the theoretical influence of topography on isotherms. The application and proof of these predictions is not well confirmed by measured data. Here we present apatite fission-track (AFT) data from samples collected along the Gotthard road tunnel and its corresponding surface line to test these predictions. AFT ages broadly cluster around 6 Ma along the tunnel. No correlation of tunnel ages with superimposed topography is seen, which means that topography-induced perturbation of isotherms under given boundary conditions (topographic wavelength 12 km; relief 1.5 km; exhumation rate 0.45 km Ma −1 ) can be neglected for the interpretation of AFT ages. Thus, in areas characterized by similar topographies and exhumation rates, apparent exhumation rates deduced from the age–elevation relationship (AER) of AFT data need no correction for topography-induced perturbation of isotherms. Three-dimensional (3D) numerical thermal modelling was carried out incorporating thermally relevant parameters and mechanisms, such as topography, geology, thermal conductivities and heat production. Modelling reveals a strong influence on the shape of isotherms caused by spatially variable thermal parameters, especially heat production rates. Therefore, not only topography has to be considered for interpreting low-temperature thermochronological data, but also other parameters like heat production rates. Supplementary material: 1. Electron microprobe analyses, 2. Topography and model extend, 3. Model parameters are all available online at http://www.geolsoc.org.uk/SUP18380 .
Multiple convergence in polyketide biosynthesis: a third folding mode to the anthraquinone chrysophanol
2009-01-01

The polyketide chrysophanol is shown to be formed, in an organism-specific way, by a third folding mode, involving a remarkable cyclization of a bicyclic diketo precursor, thus establishing the first example of multiple convergence in polyketide biosynthesis.
Theoretical and Instructional Aspects of Learning with Visualizations
2009-01-01

Multimedia environments consist of verbal and visual representations that, if appropriately processed, allow for the construction of an integrated mental model of the content. Whereas much is known on how students learn from verbal representations, there are fewer insights regarding the processing of visual information, alone or in conjunction with text. This chapter uses a semiotics approach to provide a defi- nition of visualizations as a specific form of external representation, and then discusses the differences between verbal and visual representations in how they represent information. Finally, it discusses how meaning is achieved when learning with them. The next section discusses basic perceptual and cognitive processes relevant to learning with visualizations. This background is used to specify the instructional functions that visualizations have either as self-contained instructional messages or as text adjuncts. Moreover, the role of individual differences in processing visualizations is highlighted. The chapter ends with methodological suggestions concerning the important role of interdisciplinary research and assessment methods in this area.
Mosaic Trisomy 21/Monosomy 21 in a Living Female Infant
2009-01-01

Many autosomal monosomies are presumed to end in arrested growth in the first few mitoses, prior even to the time of implantation, with possibly some proceeding to the stage of occult abortion. The single exception may be monosomy 21, although this has been questioned, with most earlier reports of monosomy 21 recently re-interpreted as being due to an unbalanced translocation involving chromosome 21. Here we report a female infant with a mosaic trisomy 21/monosomy 21 karyotype. While the karyotype 46,XX,i(21)(q10) is detected in all metaphases investigated in lymphocytes, mosaicism with the karyotype 46,XX,i(21)(q10)[31]/45,XX, –21[12] is seen in fibroblasts from a skin biopsy. Dysmorphic facial features and multiple malformations remarkably resemble cases of monosomy 21 that have been described in the literature. This suggests a dominant phenotypic effect of loss of one chromosome 21. Detailed clinical description, results of gene dosage studies, and cytogenetic analysis will be presented.
Pebble population dating as an additional tool for provenance studies - examples from the Eastern Alps
2009-01-01

Abstract Detrital fission-track (FT) dating can be successfully used in provenance studies of siliciclastic sediments to define the characteristic cooling ages of the source regions during erosion and sedimentation. In order to obtain more specific information about potential source regions we have developed the pebble population dating (PPD) method in which pebbles of specific lithotype are merged and dated. Dating of both zircon and apatite crystals from such pebble populations yields age distributions, which reflect the cooling ages of the given lithotype in the source area at the time of sedimentation. By this technique it is possible to define ‘FT litho-terrains’ in the source regions and thus outline palaeogeological maps. Two examples are presented from the Eastern Alps. (i) Comparison of FT ages from a sandstone sample and a gneiss PPD sample from an Oligocene conglomerate of the Molasse Basin shows that the youngest age cluster is present only in the sand fraction and derived from the Oligocene volcanic activity along the Periadriatic zone. The lack of the youngest ages in the gneiss pebble assemblage excludes the Oligocene exhumation of the crystalline basement from mid-crustal level. (ii) Pebble assemblages of red Bunter sandstone, gneiss and quartzite were collected from an Upper Miocene conglomerate of the Molasse Foreland Basin and merged as PPD samples. Apatite and zircon FT grain age distributions of these PPD samples, representing the largest ancient East Alpine catchment, allow generating a new combination of palaeogeological and palaeo-FT-age maps of the Eastern Alps for the Late Miocene.
Juxtacondylar Approach in Temporal Paraganglioma Surgery: When and Why?
2009-01-01

As it became clear that patients with paraganglioma (PGL) syndromes had a higher risk of multifocal tumors, we changed our surgical strategy to avoid the possibility of bilateral cranial nerve paralysis. The juxtacondylar approach offers advantages for some jugular foramen tumors, including types C and D temporal PGLs. This approach allows exposure of the jugular foramen without skeletonizing or transposing the facial nerve. It improves the surgeon's ability to distinguish between the pars vascularis and the pars nervosa at the jugular foramen, and it helps to save functioning of the lower cranial nerves. There is already considerable experience using the juxtacondylar approach for patients suffering from schwannomas and meningiomas involving the jugular foramen. Some limitations have been noted for using the juxtacondylar approach with jugular PGLs that are related to their vascular nature. In this article we demonstrate its use for the management of eight patients with locally advanced temporal PGLs and how it can be combined with an infratemporal fossa approach.
Complex all-ceramic rehabilitation of a young patient with a severely compromised dentition: a case report.
2009-01-01

A young patient with dentinogenesisimperfecta and a dentition severely compromised by discolorations,abrasion, and breakage of enamel on several teeth was prosthodontically treated with CAD/CAM-manufactured all-ceramic restorations. To reduce treatment risk, preparations were limited paragingivally. Maxillary anterior teeth and premolars were restored with adhesively luted ceramic crowns. All other teeth were treated with zirconia-based restorations luted with a self-etching resin-based material. Considering the deficient pretreatment situation, the use of tooth-colored restoration and luting materials yielded a satisfying functional and good esthetic result. The patient is highly satisfied, even though 3 minor chippings occurred shortly after the completion of treatment
Interaction of hepatitis C virus envelope glycoprotein E2 with the large extracellular loop of tupaia CD81
2009-01-01

These data suggest that the structural differences in-between the tupaia and human CD81 may alter the interaction of the large extracellular loop with HCV envelope glycoprotein E2. These findings may be important for the understanding of the mechanisms of binding and entry of HCV to PTHs.
Modeling of Thermally Assisted Magnetodynamics
2009-01-01

Thermomagnetic recording uses local heating of ferromagnetic media to locally decrease coercivity and change saturation magnetization of the material and alleviate magnetization reversal. A modified Landau-Lifshitz equation is proposed as a phenomenological model to allow for changes in magnetization magnitude and is studied both analytically and numerically.
Comparisons of Two Variants of the Method of Constant Stimuli for Estimating Difference Thresholds
2009-01-01

The two-alternative forced-choice (2AFC) and the reminder tasks are variants of the method of constant stimuli. One or the other task is usually employed for estimating the difference limen (DL) in psychophysical research. Lapid, Ulrich, and Rammsayer (2008) found that the 2AFC task yields larger DLs than the reminder task for duration discrimination judgments. The results of the present paper confirm that this discrepancy also generalizes to discrimination judgments about nontemporal, visual information (Experiment 1: Random dot pattern discrimination; Experiment 2: Line-length discrimination). It is argued that this discrepancy is related to the presentation order of the standard and the comparison stimulus.
On the Economics of Contribution Evasion
2009-01-01

This paper considers the tax evasion decision when taxes constitute contributions to the financing of social insurance programs, such as unemployment insurance. We call this evasion contribution evasion and establish that critical differences exist between contribution evasion and tax evasion, the central difference being that contributions entitle the contributor to future claims. Furthermore, we derive a recommendation for the reduction of contribution evasion, referring to the distinction between Bismarckian and Beveridgean social security systems.
The role of soluble and cell-surface expressed 4-1BB ligand in patients with malignant hemopoietic disorders
2009-01-01

The TNFR family member 4-1BB and its ligand 4-1BBL are involved in the costimulation of T-cells and tumor-derived soluble (s)4-1BBL may influence the interaction of malignant cells with the immune system. Here, we report that cell-surface-expressed (c)4-1BBL can be expressed on mononuclear blood cells from patients with acute myeloid leukemia (AML) (n = 35), myelodysplasia (n = 5) or non-Hodgkin lymphoma (n = 11) and can be coexpressed on varying proportions of lymphoid or myeloid malignant cells and on dendritic cells differentiated from AML-blasts. Direct correlations between c- and s4-1BBL were not found in the investigated cases. Up to now expression of 4-1BBL has not been described on primary myeloid malignant cells, but only on malignant cells of lymphoid or solid tumor origin or on tumor cell lines. With our work we further contribute to the understanding of the potential role of c/s4-1BBL in immune reactions and its influence on the interaction of tumor and immunoreactive cells.
Forster resonance energy transfer-based total internal reflection fluorescence reader for apoptosis
2009-01-01

A fluorescence reader for the detection of Forster resonance energy transfer (FRET) on surfaces of living cells is described. The method is based on multiple total internal reflections (TIR) of an incident laser beam within a glass slide, such that individual samples on top of the glass slide are illuminated simultaneously by an evanescent electromagnetic field. Enhanced cyan fluorescent protein (ECFP) anchored to the inner leaflet of the plasma membrane is optically excited and transfers its excitation energy via the peptide linker Asp-Glu-Val-Asp (DEVD) to an enhanced yellow fluorescent protein. Upon apoptosis, DEVD is cleaved, and energy transfer is disrupted, as proven by an increase of fluorescence intensity as well as of fluorescence lifetime of the donor ECFP. Due to selective excitation of membrane-associated fluorophores, intracellular fluorescence and background luminescence from the surrounding medium are eliminated. Therefore, this test system appears to be a sensitive device for the detection of apoptosis and more generally for drug screening or in vitro diagnosis on a nanometer scale.
Signal transduction pathways in liver and the influence of hepatitis C virus infection on their activities
2009-01-01

In liver, the most intensively studied transmembrane and intracellular signal transduction pathways are the Janus kinase signal transduction pathway, the mitogen-activated protein kinases signal transduction pathway, the transforming growth factor beta signal transduction pathway, the tumor necrosis factor alpha signal transduction pathway and the recently discovered sphingolipid signal transduction pathway. All of them are activated by many different cytokines and growth factors. They regulate specific cell mechanisms such as hepatocytes proliferation, growth, differentiation, adhesion, apoptosis, and synthesis and degradation of the extracellular matrix. The replication cycle of hepatitis C virus (HCV) is intracellular and requires signal transduction to the nucleus to regulate transcription of its genes. Moreover, HCV itself, by its structural and non-structural proteins, could influence the activity of the second signal messengers. Thus, the inhibition of the transmembrane and intracellular signal transduction pathways could be a new therapeutic target in chronic hepatitis C treatment.
Perfusion imaging of the right perisylvian neural network in acute spatial neglect
2009-01-01

Recent studies have suggested a tightly connected perisylvian neural network associated with spatial neglect. Here we investigated whether structural damage in one part of the network typically is accompanied with functional damage in other, structurally intact areas of this network. By combining normalized fluid-attenuated inversion-recovery (FLAIR) imaging, diffusion-weighted imaging (DWI), and perfusion-weighted imaging (PWI) we asked whether or not lesions centering on fronto-temporal regions co-occur with abnormal perfusion in structurally intact parietal cortex. With thresholds applied to delineate behaviourally relevant malperfusion of brain tissue, the analysis of normalized time-to-peak (TTP) and maximal signal reduction (MSR) perfusion maps did not reveal significant changes outside the area of structural damage. In particular, we found no abnormal perfusion in the structurally intact inferior parietal lobule (IPL) and/or the temporo-parietal junction (TPJ). The present results obtained in three consecutively admitted neglect patients with fronto-temporal lesions indicate that structural damage in one part of the right perisylvian network associated with spatial neglect does not necessarily require dysfunction by malperfusion in other, structurally intact parts of the network to provoke spatial neglect. The neural tissue in the fronto-temporal cortex appears to have an original role in processes of spatial orienting and exploration.
The first record on Brazilian stingless bees published 450 years ago by Hans Staden
2009-01-01

Only a few decades after 1492, when Christopher Columbus arrived on a Caribbean island and Pedro Alvares Cabral claimed Brazil for Portugal in 1500, a German mercenary gave the first description of stingless bees in 1557. He got to know them when he was imprisoned for months by an anthropophagous tribe in the coastal region of Santos, today in the State of São Paulo. This rather short but nevertheless extremely exact record on stingless bees is hidden in the first book on Brazil. Three species and important aspects of their life history were treated. This early description has been completely overlooked by bee scientists until now. My note intends to close this evident gap.