julilili42/papers huggingface dataset:
Pantomime of Tool Use Depends on Integrity of Left Inferior Frontal Cortex
2007-03-05

Pantomime of tool use is a frequently used test for apraxia. For basic cognitive neuroscience, pantomime of tool use is of interest because it constitutes a link between instrumental and communicative manual actions. We used lesion subtraction analysis to determine the locations specifically associated with defective pantomime of tool use in patients with left-brain damage and aphasia. Subtraction of lesions of patients with normal pantomime from those with defective pantomime yielded a maximum difference in the inferior frontal gyrus and adjacent portions of the insula and precentral gyrus. This result remained essentially the same when possible confounding influences of impaired language comprehension and of lesion size were controlled by selecting patients equated on these measures and when only patients with preserved imitation of gestures were considered. By contrast, parietal lesions did not have a specific impact on pantomime. We speculate that the vulnerability of pantomime to lesions of left inferior frontal cortex is due to the high demands on selection of a very restrained range of features out of the many features that may come to mind when imagining the actual use of the tool.
Propylene Oxide
2007-03-05

[75-56-9] C3H6O (MW 58.09) InChI = 1S/C3H6O/c1-3-2-4-3/h3H,2H2,1H3 InChIKey = GOOHAUXETOMSMM-UHFFFAOYSA-N (monomer for polymerization; electrophile; chiral building block) Alternate Names: 1,2-epoxypropane; methyloxirane. Physical Data: mp −112 °C; bp 34 °C; d 0.859 g cm−3; [α]D20 +14.6° for the (R)-enantiomer, corrected to 100% ee. Solubility: sol H2O (405 g L−1); miscible with organic solvents. Form Supplied in: colorless liquid; commercially available as a racemic mixture and as the enantiomers. Drying: distillation from calcium hydride or calcium. Upon cooling, a hydrate C3H6O·(H2O)16 of mp −3 °C is precipitated from the moist oxirane as white crystals.2 Analysis of Reagent Purity: 13C NMR (CDCl3): δ 47.1, 46.8 (C-1, C-2), 17.2 (C-3) ppm; determination of ee by complexation gas chromatography on nickel(II) bis[3-heptafluorobutanoyl-(1R)-camphorate] in squalane, separation factor α 1.24 at 50 °C;3 other suitable chiral stationary phases are nickel(II) bis[2-heptafluorobutanoyl-(S)-4-methylthujan-3-onate] and manganese(II) bis[3-heptafluorobutanoyl-(1R)-camphorate].4 Preparative Methods: (R)-propylene oxide is prepared (eq 1) in three steps: diazotization of (S)-alanine with Sodium Nitrite in hydrochloric acid; to give (S)-2-chloropropanoic acid; reduction to 2-chloropropan-1-ol with Lithium Aluminum Hydride; and cyclization by distillation from Potassium Hydroxide pellets.4, 5 (1) The (S)-enantiomer is prepared from (S)‐Ethyl Lactate via (S)-propane-1,2-diol, and cyclization of a mixture of (S)-2-acetoxy-1-bromopropane and (R)-2-bromo-1-acetoxypropane (eq 2).6, 7 (2) Alternatively, conversion of (S)-ethyl lactate into the mesylate is followed by reduction of the ester group with Aluminum Hydride/THF and ring closure with aqueous KOH.8 Another route to (S)-propylene oxide involves protection of the (secondary) hydroxyl group of (S)-ethyl lactate with Ethyl Vinyl Ether, followed by reduction of the ester group with LiAlH4, conversion of the primary hydroxyl group into the tosylate, acidic deprotection of the secondary hydroxyl group, and cyclization with aqueous KOH.9 By means of a combined microbial/chemical synthesis, (R)-propylene oxide is obtained from glucose with ee >99%.10 Metal-mediated access to both enantiomers is provided by either chromatographic or kinetic resolution of racemic propylene oxide, and also by asymmetric epoxidation of propylene.11 Handling, Storage, and Precautions: a suspected carcinogen for humans; it is inflammable and explosive; because of its high volatility, cooling to 0 °C before use is recommended. Use in a fume hood.
Methanesulfonic Acid
2007-03-05

[75-75-2] CH4O3S (MW 96.12) InChI = 1S/CH4O3S/c1-5(2,3)4/h1H3,(H,2,3,4) InChIKey = AFVFQIVMOAPDHO-UHFFFAOYSA-N (cyclocondensation reagent; precursor for methanesulfonyl chloride and anhydride; catalyst for polymerization, alkylation, and esterification reactions) Alternate Name: MsOH. Physical Data: mp 20 °C; bp 167 °C/10 mmHg, 122 °C/1 mmHg; d 1.481 g cm−3; nD20 1.3210. Solubility: sol water, ethanol, ether; insol hexane; very sparingly sol benzene, toluene. Form Supplied in: technical quality is 95% pure containing 2% water. Analysis of Reagent Purity: 17O NMR.1 Preparative Method: by oxidation of Dimethyl Sulfide with Dimethyl Sulfoxide in the presence of water and a catalytic amount of Hydrogen Bromide.17 Purification: stir with P2O5 (20 g for 500 mL of the acid) at 100 °C for 0.5 h and then distill under vacuum. Handling, Storage, and Precautions: irritant and highly corrosive liquid; should be stored in glass containers. Use in a fume hood.
Ligand Bound β1 Integrins Inhibit Procaspase-8 for Mediating Cell Adhesion-Mediated Drug and Radiation Resistance in Human Leukemia Cells
2007-03-06

The presented data suggest that the ligand status of beta1 integrins is critical for their antiapoptotic effect in leukemia cells treated with Ara-C, FasL or ionizing radiation. The antiapoptotic actions involve formation of a beta1 integrin/Akt complex, which signals to prevent procaspase-8-mediated induction of apoptosis in a PI3K-dependent manner. Antagonizing agents targeting beta1 integrin and PI3K/Akt signaling in conjunction with conventional therapies might effectively reduce radiation- and drug-resistant tumor populations and treatment failure in hematological malignancies.
Fixed-Parameter Algorithms in Phylogenetics
2007-03-06

We survey the use of fixed-parameter algorithms in the field of phylogenetics, which is the study of evolutionary relationships. The central problem in phylogenetics is the reconstruction of the evolutionary history of biological species, but its methods also apply to linguistics, philology or architecture. A basic computational problem is the reconstruction of a likely phylogeny (genealogical tree) for a set of species based on observed differences in the phenotype like color or form of limbs, based on differences in the genotype like mutated nucleotide positions in the DNA sequence, or based on given partial phylogenies. Ideally, one would like to construct socalled perfect phylogenies, which arise from a very simple evolutionary model, but in practice one must often be content with phylogenies whose 'distance from perfection' is as small as possible. The computation of phylogenies has applications in seemingly unrelated areas such as genomic sequencing and finding and understanding genes. The numerous computational problems arising in phylogenetics often are NP-complete, but for many natural parametrizations they can be solved using fixed-parameter algorithms.
New method to quantify erythrophagocytosis by autologous monocytes
2007-03-06

Abstract Background: Anemia is the net result of decreased red blood cell (RBC) production and increased removal of RBCs. Replication and maturation of erythroid precursors and RBC lysis can be measured by standardized in vitro methods and surrogate markers, respectively. In contrast, erythrophagocytosis by autologous phagocytes is more difficult to quantify. Methods: We developed a method to assess erythrophagocytosis by autologous monocytes from 5 ml of whole blood. RBCs were labeled with carboxyfluorescein‐diacetate‐succinimidyl ester (CFDA‐SE) and subsequently coincubated with autologous CD14 + monocytes. Phagocytosis was quantified using flow cytometry. After standardization, the assay was validated in patients with severe malarial anemia (SMA), a condition that is associated with increased erythrophagocytosis. Results: After labeling, CFDA‐SE was stably incorporated into RBCs and no significant leakage leading to contamination of nonlabeled cells was observed. Monocytes ingested opsonized, labeled RBCs seven times more than nonopsonized controls. Erythrophagocytosis was significantly higher in SMA than in healthy controls. Conclusions: The established assay showed enhanced autoerythrophagocytosis associated with SMA and hence was able to detect clinically relevant erythrophagocytosis. This novel assay is well suited for rapid quantification of in vitro erythrophagocytosis by autologous monocytes. © 2007 International Society for Analytical Cytology.
The meatal mobilization technique for coronal/subcoronal hypospadias repair
2007-03-06

OBJECTIVE To describe meatal mobilization (MEMO) by distal urethral preparation as an improved surgical technique for distal hypospadias repair, including glanular, coronal and subcoronal location of the meatus, with or without chordee. PATIENTS AND METHODS From May 2002 to June 2006, 46 patients (mean age 3.8 years, range 1.5–14) had a repair of glanular, coronal and subcoronal hypospadias using the MEMO technique. A description of the procedure and the results are presented. RESULTS The mean duration of surgery was 73 min; there were no complications during surgery in any of the patients. The follow‐up was 28.5 months; after surgery one patient developed a haematoma, which resolved with no further treatment. There was neither recurrence nor any new episode of chordee or meatal stenosis. None of the patients developed a urethral fistula. In one patient the meatus retracted but remained in the glans. CONCLUSIONS Complications were minimal and the cosmetic results excellent using the MEMO technique for correcting most of distal hypospadias.
Diagnosis and treatment of cutaneous melanoma: state of the art 2006*
2007-03-07

Although the incidence of melanoma is still rising in Caucasian populations, the increase in mortality has leveled off. Improvements in early diagnosis, with more frequent diagnosis of low-risk patients (i.e. those with <1 mm of tumor thickness), is the main reason for these divergent developments. Primary prevention has not yet been successful and recent studies have demonstrated the lack of effectiveness of sunscreen in preventing nevi in children. Progress was made in early melanoma diagnosis when dermoscopy and digital dermoscopy were introduced, and computer algorithms have proved to be highly efficacious for automated melanoma diagnosis. Primary melanomas are now excised with narrower surgical margins of 1-2 cm. Sentinel-node biopsy is recommended as a nodal staging procedure in patients with tumor thickness of 1 mm and more, but the prognostic impact of this procedure has not yet been demonstrated. New imaging techniques, e.g. whole-body MRI and PET-CT, provide more accurate staging, particularly in patients with apparent metastasis, and facilitate decisions on surgical treatment strategies. Staging is now based on the 2001 TNM classification including tumor thickness and histopathologic ulceration in stages I and II and lymph node micro and macro-metastasis in stage III. A stage- and risk-adopted follow-up schedule is proposed for melanoma surveillance. Adjuvant therapy with interferon-alpha in high-risk patients offers a small benefit in terms of recurrence-free and overall survival; the optimal dosage and duration of this treatment are still to be defined. Almost no progress has been made in the medical treatment of disseminated metastasis of melanoma. Therapy with dacarbazine and a few other single agents remains the first-line treatment approach of choice. A number of new treatment modalities, including targeted molecules and immunologic approaches with monoclonal antibodies, are under development; hopefully, new treatment modalities will be available in the near future.
Reduced natural killer (NK) function associated with high-risk myelodysplastic syndrome (MDS) and reduced expression of activating NK receptors
2007-03-07

Abstract Myelodysplastic syndromes (MDS) are characterized by ineffective hematopoiesis with potential for progression to acute myeloid leukemia (AML). We compared natural killer (NK) cytolytic function in 48 MDS patients with 37 healthy donors and found reduced activity in the patient population (K562 cytolysis, 19% ± 21% SD versus 40% ± 17%) (P &lt; .001). NK cytotoxicity in MDS patients was reduced against 3 disparate tumor targets with differential activating receptor requirement, suggesting global defects in NK function. Reduced NK function in MDS was significantly associated with higher International Prognostic Score (P = .01), abnormal karyotype (P = .05), the presence of excess blasts (P = .01), and age-adjusted bone marrow hypercellularity (P = .04). MDS patients had a display of the activating receptor NKp30, and NKG2D down-regulation closely correlated with impaired NK function (P = .001). NKG2D ligands (MICA and MICB) were expressed on CD34+ cells from bone marrow of 30% of MDS patients and a leukemic cell line derived from an MDS patient (MDS1). Collectively, these findings suggest that impairment of NK cytolytic function derives in part from reduced activating NK receptors such as NKG2D in association with disease progression. Evasion of NK immunosurveillance may have importance for MDS disease progression.
The ‘unromantic pictures’ of quantum theory
2007-03-07

I am concerned with two views of quantum mechanics that John S. Bell called ``unromantic'': spontaneous wave function collapse and Bohmian mechanics. I discuss some of their merits and report about recent progress concerning extensions to quantum field theory and relativity. In the last section, I speculate about an extension of Bohmian mechanics to quantum gravity.
Selective Induction of Human Hepatic Cytochromes P450 2B6 and 3A4 by Metamizole
2007-03-07

The pyrazolone drug metamizole is a widely used analgesic. Analysis of liver microsomes from patients treated with metamizole revealed selectively higher expression of cytochromes P450, CYP2B6 and CYP3A4 (3.8- and 2.8-fold, respectively), and 2.9-fold higher bupropion hydroxylase activity compared with untreated subjects. Further investigation of metamizole and various derivatives on different potential target genes in human primary hepatocytes demonstrated time- and concentration-dependent induction by metamizole of CYP2B6 (7.8- and 3.1-fold for mRNA and protein, respectively, at 100 muM) and CYP3A4 (2.4- and 2.9-fold, respectively), whereas other genes (CYP2C9, CYP2C19, CYP2D6, NADPH:cytochrome P450 reductase, ABCB1, constitutive androstane receptor (CAR), pregnane X receptor (PXR)) were not substantially altered. Using reporter gene assays, we show that metamizole is not acting as a direct ligand to either PXR or CAR, suggesting a phenobarbital-like mechanism of induction. These data warrant further studies to elucidate the drug-interaction potential of metamizole, especially in patients with long-term treatment.
Quantum mechanics in multiply-connected spaces
2007-03-07

We explain why, in a configuration space that is multiply connected, i.e., whose fundamental group is nontrivial, there are several quantum theories, corresponding to different choices of topological factors. We do this in the context of Bohmian mechanics, a quantum theory without observers from which the quantum formalism can be derived. What we do can be regarded as generalizing the Bohmian dynamics on to arbitrary Riemannian manifolds, and classifying the possible dynamics that arise. This approach provides a new understanding of the topological features of quantum theory, such as the symmetrization postulate for identical particles. For our analysis we employ wave functions on the universal covering space of the configuration space.
Molecular genetic analysis of NBS1 in German melanoma patients
2007-03-07

The aim of this study was to investigate the role of NBS1 in the pathogenesis of malignant melanoma of the skin. To exclude the common 657del5 founder mutation, a total of 376 melanoma patients from Southern Germany were analyzed for sequence alterations in exon 6 of NBS1 by direct sequencing. Analyses revealed one 657del5 mutation and three nonsynonymous sequence variations in exon 6 of NBS1 (V210F, R215W, and F222L). Analysis of an additional sample of 629 melanoma patients and 604 controls revealed no F222L mutation, indicating that this newly identified sequence alteration is not a common polymorphism. In a case-control association study including 632 melanoma patients and 615 cancer-free control participants from Southern Germany, three publicly known single nucleotide polymorphisms located in the NBS1 gene region were analyzed. No significant associations between single nucleotide polymorphisms (rs9995, rs867185 and rs1063045) or referring calculated haplotypes and melanoma risk were identified. These results suggest that NBS1 does not play a major role in predisposition to melanoma in the Southern German population but that alterations of this gene might contribute to the risk of this cancer.
Über die Identität eines sogenannten Ammoniumcarbonat‐Präparates
2007-03-07

Abstract On the Identity of a so‐called Ammonium Carbonate Sample Commercial samples of so‐called “ammionum carbonate” are shown to contain ammonium carbamate rather than ammonium carbonate. In fact samples may contain varying quantities of α‐ and β‐(NH 4 )(CO 2 NH 2 ), of which only the α‐phase is reported in the literature. Mixtures of both phases tend to leak the volatile α‐phase and to react with moisture to form (NH 4 )(HCO 3 ). The crystal structure of the new β‐(NH 4 )(CO 2 NH 2 ) is refined from X‐ray powder data.
Synthesis and Structure of the Basic Alkaline Earth Nitrates Sr2(OH)3NO3 and Ba2(OH)3NO3.
2007-03-07

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A CD99-related antigen on endothelial cells mediates neutrophil but not lymphocyte extravasation in vivo
2007-03-08

Abstract CD99 is a long-known leukocyte antigen that does not belong to any of the known protein families. It was recently found on endothelial cells, where it mediates transendothelial migration of human monocytes and lymphocyte recruitment into inflamed skin in the mouse. Here, we show that CD99L2, a recently cloned, widely expressed antigen of unknown function with moderate sequence homology to CD99, is expressed on mouse leukocytes and endothelial cells. Using antibodies, we found that CD99L2 and CD99 are involved in transendothelial migration of neutrophils in vitro and in the recruitment of neutrophils into inflamed peritoneum. Intravital and electron microscopy of cremaster venules revealed that blocking CD99L2 inhibited leukocyte transmigration through the vessel wall (diapedesis) at the level of the perivascular basement membrane. We were surprised to find that, in contrast to CD99, CD99L2 was not relevant for the extravasation of lymphocytes into inflamed tissue. Although each protein promoted cell aggregation of transfected cells, endothelial CD99 and CD99L2 participated in neutrophil extravasation independent of these proteins on neutrophils. Our results establish CD99L2 as a new endothelial surface protein involved in neutrophil extravasation. In addition, this is the first evidence for a role of CD99 and CD99L2 in the process of leukocyte diapedesis in vivo.
Reactive plasticity in the dentate gyrus following bilateral entorhinal cortex lesions in cynomolgus monkeys
2007-03-08

Abstract Hippocampal structural plasticity induced by entorhinal cortex (EC) lesions has been studied extensively in the rat, but little comparable research has been conducted in primates. In the current study we assessed the long‐term effects of bilateral aspiration lesions of the EC on multiple markers of circuit organization in the hippocampal dentate gyrus of young adult monkeys ( Macaca fascicularis ). Alternate histological sections were processed for the visualization of somatostatin and vesicular acetylcholine transporter (VAChT) immunoreactivity and acetylcholinesterase histochemistry (AChE). The markers revealed the distinct laminar organization of dentate gyrus circuitry for stereology‐based morphometric quantification. Consistent with findings in rats, the volume of the somatostatin‐immunopositive outer molecular layer (OML), innervated by projections from the EC, was decreased by 42% relative to control values. The inner molecular layer (IML) displayed a corresponding volumetric expansion in response to denervation of the OML as measured by AChE staining, but not when visualized for quantification by VAChT immunoreactivity. Nonetheless, stereological estimation revealed a 36% increase in the total length of VAChT‐positive cholinergic fibers in the IML after EC damage, along with no change in the OML. Together, these findings suggest that despite substantial species differences in the organization of hippocampal circuitry, the capacity for reactive plasticity following EC damage, previously documented in rats, is at least partly conserved in the primate dentate gyrus. J. Comp. Neurol. 500:192–201, 2007. © 2007 Wiley‐Liss, Inc.
Quantification of glomerular filtration rate by measurement of gadobutrol clearance from the extracellular fluid volume: comparison of a TurboFLASH and a TrueFISP approach
2007-03-08

Purpose: As the MR contrast-medium gadobutrol is completely eliminated via glomerular filtration, the glomerular filtration rate (GFR) can be quantified after bolus-injection of gadobutrol and complete mixing in the extracellular fluid volume (ECFV) by measuring the signal decrease within the liver parenchyma. Two different navigator-gated single-shot saturation-recovery sequences have been tested for suitability of GFR quantification: a TurboFLASH and a TrueFISP readout technique. Materials and Methods: Ten healthy volunteers (mean age 26.1±3.6) were equally devided in two subgroups. After bolus-injection of 0.05 mmol/kg gadobutrol, coronal single-slice images of the liver were recorded every 4-5 seconds during free breathing using either the TurboFLASH or the TrueFISP technique. Time-intensity curves were determined from manually drawn regions-of-interest over the liver parenchyma. Both sequences were subsequently evaluated regarding signal to noise ratio (SNR) and the behaviour of signal intensity curves. The calculated GFR values were compared to an iopromide clearance gold standard. Results: The TrueFISP sequence exhibited a 3.4-fold higher SNR as compared to the TurboFLASH sequence and markedly lower variability of the recorded time-intensity curves. The calculated mean GFR values were 107.0±16.1 ml/min/1.73m2 (iopromide: 92.1±14.5 ml/min/1.73m2) for the TrueFISP technique and 125.6±24.1 ml/min/1.73m2 (iopromide: 97.7±6.3 ml/min/1.73m2) for the TurboFLASH approach. The mean paired differences with TrueFISP was lower (15.0 ml/min/1.73m2) than in the TurboFLASH method (27.9 ml/min/1.73m2). Conclusion: The global GFR can be quantified via measurement of gadobutrol clearance from the ECFV. A saturation-recovery TrueFISP sequence allows for more reliable GFR quantification as a saturation recovery TurboFLASH technique.