bluuebunny/crossref_metadata_2025 huggingface dataset:
Skeletal Isomerization of n-Butane Catalyzed by an Acidic Cesium Salt of 12-Tungstophosphoric Acid
Authors: Na Kyutae , Okuhara Toshio , Misono Makoto
Published: April 2006

A salt of H3PW12O40, Cs2.5H0.5PW12O40, catalyzed efficiently the skeletal isomerization of n-butane to isobutane at 300 °C. The activity and selectivity were much higher than those of SO22−/ZrO2. H-ZSM-5 was more active than Cs2.5H0.5PW12O40, but the selectivity was very low.
Observation of Highly Endoergic Chemiluminescent Reactions on Laser Ablation of Metals. Detection of AlH (A1Π), AlN (A3Πi), AlO (B2Σ+) and MgO (B1Σ+) in Al + NH3, Al + H2O, and Mg + O2 Systems
Authors: Ishitani Eizi , Yoshimoto Satoshi , Higashide Hiroshi , Kobayashi Makoto , Shinohara Hisanori , Sato Hiroyasu
Published: April 2006

Occurrence of highly endoergic chemiluminescent reactions was observed using laser ablation of metal targets for Al + NH3, Al + H2O and Mg + O2 systems. Observed chemiluminescent species were AlH (A1Π), AlN (A3Πi), AlO (B2Σ+) and MgO (B1Σ+).
Effects of Solvent Molecular Size on Dissociation Rates of the N–H Bond in Ammonium Salts Derived from Tertiary Amines
Authors: Oki Michinori , Matsusaka Michio , Mishima Hirohito , Toyota Shinji
Published: April 2006

Rates of dissociation of the N–H bond in ammonium salts derived from tertiary amines were found to be enhanced in solvents of which molecular size is large with respect to those in solvents of small molecular size, if polarities of the solvents are about the same. The effects are attributed to the weak solvation by the solvents of large molecular size which is associated with small positive entropy of activation. Thus the third aspect of solvent effects, bulkiness of solvent molecules, is proposed.
Generation of Alkyl Radicals from 1-Oxidoalkylidenechromium(0) Complexes by Oxidation with Manganese(III) 2-Pyridinecarboxylate and Their Reactions with Olefins
Authors: Narasaka Koichi , Sakurai Hidehiro
Published: April 2006

Tetramethylammonium pentacarbonyl(1-oxidoalkylidene)chromium(0) complexes, prepared from the corresponding carbanion and hexacarbonylchromium(0), are oxidized with manganese(III) 2-pyridinecarboxylate to generate carbon-centered radicals which react with various olefins giving the intermolecular addition products.
Extraordinary Large Red Shift of the n(Si)→3p(Si) Transition of Silylenes Caused by Trimethylsilyl and Trimethylgermyl Substituents
Authors: Kira Mitsuo , Maruyama Toyotaro , Sakurai Hideki
Published: April 2006

The n(Si)→3p(Si) absorption maxima of silylenes were shifted significantly red by introducing trimethylsilyl and trimethylgermyl substituents. The origin of the substituent effects will be attributed to the σ-electron donating ability of the trimethylmetal groups which lift the energy level of n(Si) orbital significantly.
Migration of the Hydroxyl Group of N-Hydroxy-N-phenylamides to the Phenyl Group with Tertiary Phosphines and Tetrachloromethane. A Novel Transhydroxylation Reaction
Authors: Kikugawa Yasuo , Mitsui Kimiyo
Published: April 2006

The hydroxyl group of N-hydroxy-N-phenylamides rearranges mainly to the ortho position of the N-phenyl ring by the system (n-Bu)3P-CCl4-CH3CN; use of less than a stoichiometric amount of (n-Bu)3P is effective for this reaction.
Abrupt Conversion of Mixed-Valence State in Trinuclear Iron Cyanoacetate Complex
Authors: Nakamoto Tadahiro , Katada Motomi , Kawata Satoshi , Kitagawa Susumu , Kikuchi Kouichi , Ikemoto Isao , Endo Kazutoyo , Sano Hirotoshi
Published: April 2006

The crystal structure of newly synthesized trinuclear iron cyanoacetate complex, [Fe3O(NCCH2CO2)6(H2O)3], has been determined by single-crystal X-ray structure analysis and found to have a three-dimensional hydrogen-bond network. The temperature dependence of Mössbauer spectrum shows that the complex converts from a valence-trapped state to a valence-detrapped state within a 10 K range.
Partial Oxidation of Methane Using the Redox of Cerium Oxide
Authors: Otsuka Kiyoshi , Ushiyama Tetsuya , Yamanaka Ichiro
Published: April 2006

Direct conversion of methane into synthesis gas of H2/CO ratio of 2 has been demonstrated using CeO2 as an oxidant at 873–1073 K. The reaction was accelerated in the presence of Pt black (1 wt%). The reduced cerium oxide after the oxidation of methane can be used to convert carbon dioxide into carbon monoxide.
Novel Preparation, Characterization and Catalytic Properties of Polymer-Protected Cu/Pd Bimetallic Colloid
Authors: Toshima Naoki , Wang Yuan
Published: April 2006

Polymer-protected Cu/Pd bimetallic colloids with different atomic ratio of Cu to Pd were successfully prepared by refluxing a glycol solution of hydroxide of copper and palladium in the presence of poly(N-vinyl-2-pyrrolidone). The TEM, XRD, AAS and UV-vis spectrum measurements indicate the formation of bimetallic alloy phase in the bimetallic colloids. High catalytic activity and selectivity for the hydration of acrylonitrile to acrylamide was achieved by using the Cu/Pd(Cu/Pd = 2) bimetallic colloid as a catalyst.
Long-lived Charge Separated States from Zinc Porphyrin-Free Base Porphyrin-Diimide-Quinone Tetrads
Authors: Osuka Atsuhiro , Zhang Run-Ping , Maruyama Kazuhiro , Ohno Takeshi , Nozaki Koichi
Published: April 2006

Tetrads consisting of zinc porphyrin (ZnP), free base porphyrin (H2P), naphthalene-1,4,5,8-tetracarboxylic diimide (NIm), and quinone (Q) were synthesized. Upon photoexcitation, these tetrads provide ion pair states (ZnP)+-H2P-NIm-(Q)−, whose lifetimes are much longer, reaching more than 100 μs in THF-butyronitrile, in biphenyl-bridged models but shorter in diphenylmethyl-bridged models in comparison to the corresponding Q-free triads.
Chiral Synthesis of (−)-Colletol Based on Palladium-Catalyzed Reductive Cleavage of Alkenyloxiranes with Formic Acid
Authors: Shimizu Isao , Omura Tetsuya
Published: April 2006

Total synthesis of (−)-colletol was achieved using palladium-catalyzed hydrogenolysis of optically active (E)-4,5-epoxy-2-alkenoates to (E)-5-hydroxy-2-alkenoates with formic acid as a key step for preparation of the intermediate hydroxy ester segments.
The Catalytic Reduction of Aldehydes and Ketones with 2-Propanol over Silica-Supported Zirconium Catalyst
Authors: Inada Kazushige , Shibagaki Makoto , Nakanishi Yukio , Matsushita Hajime
Published: April 2006

Reduction of aldehydes and ketones with 2-propanol proceeded efficiently over silica-supported zirconium catalyst, and the corresponding alcohols were obtained in high yields. In the reduction of aldehyde, the acetalization did not occur and the side reaction, the aldol condensation, was inhibited.
“Elasticity Index” for the Connecting Groups of Double-Chain Amphiphiles Bearing Two Hydrophilic Groups
Authors: Masuyama Araki , Kawano Tomoko , Zhu Yun-Peng , Kida Toshiyuki , Nakatsuji Yohji
Published: April 2006

The surface pressure-area (π-A) isotherms for a series of double-chain diols derived from diepoxides were measured. A new parameter, “Elasticity Index”, is proposed to explain the effect of the connecting group between the two lipophilic chains of double-chain amphiphiles on the behavior of their monolayer films at the air-water interface.
Alignment by Poling and Regioselective Photodimerization of Stilbazolium Ions Dispersed in Polyelectrolytes
Authors: Takagi Katsuhiko , Shibata Shigeyuki , Oguri Sachiko , Sawaki Yasuhiko , Suzuoki Yasuo , Segi Takeshi
Published: April 2006

4-(N,N-Dimethylamino)stilbazolium ion dispersed in thin films of poly(styrenesulfonates) (PSS) or copolymer of poly(ethylene and maleates) (PEcoMA) was shown to be aligned by electric field poling on the basis of the resulting photodimerization giving the syn-head-to-head dimers.
Mechanism of Photochemical Reaction of Contact Charge Transfer Pair between 1,1-Diarylethene and Oxygen
Authors: Kojima Masanobu , Ishida Akito , Takamuku Setsuo
Published: April 2006

Selective excitation of the contact charge transfer band between 1,1-diarylethene and oxygen in dichloromethane and acetonitrile gave 3,3,6,6-tetraaryl-1,2-dioxane and benzophenone derivative through an electron transfer reaction. The proposed mechanism was confirmed by the direct observation of the dimer cation radical of the olefin trapped by a triplet oxygen in pulse radiolysis.
Transition Metal Catalyzed Reaction of Peralkylated 3,4-Bis(alkylidene)-1,2-disilacyclobutane
Authors: Kusukawa Takahiro , Kabe Yoshio , Ando Wataru
Published: April 2006

Peralkylated 3,4-bis(alkylidene)-1,2-disilacyclobutanes prepared by convenient synthetic route were quantitatively converted to 3,4,7,8-tetrakis(alkylidene)-1,2,5,6-tetrasilacyclooctane (twist and chair 1:1 mixture) by Pd-catalyzed reaction. In the presence of unsaturated compounds, this disilane metathesis reaction was inhibited to give double silylation products. The reaction pathways are highly dependent upon electronic factors of unsaturated compounds and the catalyst.
Quantification of Biochemical Markers of Bone Turnover by Kinetic Measures of Bone Formation and Resorption in Young Healthy Females
Authors: Weaver Connie M. , Peacock Munro , Martin Berdine R. , McCabe George P. , Zhao Jian , Smith David L. , Wastney Meryl E.
Published: April 2006

The quantification of biochemical markers of bone formation and resorption with kinetic measures of bone turnover is an essential step in their validation. Some biochemical markers have been validated by quantification against formation and resorption rates measured by calcium kinetics in adults with bone disease. However, none has been validated in healthy individuals who are undergoing skeletal growth and bone consolidation. Therefore, we have measured biochemical markers of bone formation (serum osteocalcin [OC], bone-specific alkaline phosphatase [BAP], and total alkaline phosphatase [ALP]) and resorption (serum tartrate resistant acid phosphatase [TRAP], urinary cross-linked N teleopeptides of type I collagen/creatinine [NTx/Cr], and hydroxyproline/creatinine [OHP/Cr]) in healthy females aged 11–32 years (n = 31) after an overnight fast to determine their relationship with bone formation (Vo+) and bone resorption (Vo−) as measured by calcium kinetics and balance. All biochemical markers were highly intercorrelated (r > 0.6, p < 0.001) as were Vo+ and Vo− (r = 0.91, p < 0.001). Highly significant correlations were present between bone formation measured by calcium kinetics (Vo+) and serum levels of bone biochemical markers (OC, r = 0.82, p = 0.001; ALP, r = 0.92, p = 0.001; and BAP, r = 0.90, p = 0.001) and between bone resorption measured by calcium kinetics (Vo−) and fasting serum levels and urine creatinine ratios of biochemical markers (TRAP, r = 0.77, p < 0.001; OHP/Cr, r = 0.79, p < 0.001; and NTx/Cr, r = 0.70, p < 0.001). Thus, biochemical markers of bone formation and resorption can be used to predict calcium kinetic rates during skeletal growth and the early years of formation of peak bone mass, ages at which strategies to build peak bone mass are important. Biochemical markers of formation and resorption are equally useful in predicting either the bone formation rate or the resorption rate.
Plasmin-Mediated Proteolysis of Osteocalcin
Authors: Novak J. F. , Hayes J. D. , Nishimoto S. K.
Published: April 2006

Plasmin cleaves osteocalcin at a site within its carboxyl end, thus creating an N-midterminal 1–43 and a short C-terminal 44–49 peptides. The products of the cleavage were identified by matrix assisted laser desorption ionization time of flight mass spectrophotometry and by reversed phase high performance liquid chromatography followed by N-terminal sequence determination. When separated by sodium dodecyl sulfide-polyacrylamide gel electrophoresis in the presence of reducing agents, large (LF; N-midterminal) and a small molecular weight (SF; C-terminal) fragments can be identified. The major cleavage site involves arg43-arg44 amino acid residues, and the resulting 44–49 C-terminal fragment appears as a slow migrating band on native gels (SFnat). Elevated levels of calcium ion inhibit the plasmin-mediated lysis of osteocalcin. Plasmin-mediated cleavage of osteocalcin occurs both in solution and when bound to hydroxyapatite. Both osteocalcin cleavage products detach from the hydroxyapatite substrate. Diisopropyl fluorophosphate–inhibited plasmin does not displace osteocalcin from the hydroxyapatite surface. Previously, the C-terminal pentapeptide has been shown to be chemotactic for bone cells while bone particles lacking osteocalcin were resistant to bone resorption. We therefore hypothesize that the plasmin-mediated digestion of free and hydroxyapatite-bound osteocalcin could play a role in the regulation of bone remodeling.
Bisphosphonate Effects and the Bone Remodeling Transient
Authors: Heaney Robert P. , Yates A. John , Santora Arthur C.
Published: April 2006

Published randomized clinical trial data for alendronate, given at a dose of 10 mg/day, were fitted by a computer algorithm to the currently accepted model of the bone remodeling process. The purpose was to determine how much of the reported improvement in lumbar spine bone density could be attributed to the inevitable remodeling transient and how much might represent positive bone balance. Very good fits to the clinical data were easily obtained, indicating the general validity of current syntheses of bone remodeling biology. The best fit was provided by simulations produced by combinations of 36–38% suppression of remodeling activation and positive remodeling balance ranging from 1.1 to 1.4% per year. Whole body bone biomarker changes would have suggested both a slightly greater degree of suppression and a higher baseline level of remodeling than could be provided by any of the simulations if they were to fit the clinical data. Either regional skeletal heterogeneity or lack of a one-to-one quantitative relationship between remodeling changes and biomarker changes may explain the discrepancies between the two approaches.
Hydroxyapatite Induces Autolytic Degradation and Inactivation of Matrix Metalloproteinase-1 and -3
Authors: Kremer Edward A. , Chen Yan , Suzuki Ko , Nagase Hideaki , Gorski Jeffrey P.
Published: April 2006

In the course of studies to identify a protease capable of producing a long-lived 50 kDa fragment of bone acidic glycoprotein-75 (BAG-75), it was observed that incubation of matrix metalloproteinase (MMP)-3 (stromelysin 1) with preparations of BAG-75 led to inactivation of proteolytic function, e.g., an inability to fragment125I-labeled BAG-75 added subsequently. MMP-1 (interstitial collagenase) was also inactivated by exposure to BAG-75 preparations. Investigation of the mechanism revealed that BAG-75 preparations contained millimolar levels of inorganic phosphate which formed hydroxyapatite crystals under digestion conditions. Hydroxyapatite crystals alone and in BAG-75–hydroxyapatite complexes induced the autolytic degradation of both active and precursor forms of MMP-1 and MMP-3. Autolytic degradation in the presence of hydroxyapatite was demonstrated by a loss in catalytic function assayed with peptide and/or protein substrates, and, by fragmentation into polypeptides of <10 kDa. The fate of MMP-3 incubated with hydroxyapatite depends upon the time of incubation, the free calcium concentration, and the concentration of crystals. Specifically, hydroxyapatite-induced autolysis requires a near physiological free calcium concentration of 0.5–1.0 mM. Autolysis was maximal in the presence of 150 μg/ml hydroxyapatite where MMP-3 was only partially bound to crystals. However, autolysis also occurred at higher crystal concentrations where all input MMP-3 was bound (>1000 μg/ml), suggesting that autolysis may be mediated by bound enzyme. The effect of hydroxyapatite appears to be specific for MMP-1 and MMP-3 since the catalytic activity of chymotrypsin, trypsin, papain, and thermolysin remained unchanged after exposure to hydroxyapatite. These results document for the first time a novel catalytic role for hydroxyapatite crystals in vitro and provide an initial biochemical characterization of the intermolecular, autolytic, calcium ion-dependent, matrix metalloproteinase-specific degradative mechanism.
Effects of Zinc Supplementation on Vertebral and Femoral Bone Mass in Rats on Strenuous Treadmill Training Exercise
Authors: Seco C. , Revilla M. , Hernández E. R. , Gervás J. , González-Riola J. , Villa L. F. , Prof. Dr. Rico H.
Published: April 2006

The hypothesis that a zinc (Zn) deficit may cause osteopenia in athletes is well founded. In rats exposed to strenous exercise, we evaluated the effect of a zinc supplement on femoral and vertebral bone mass determined by dual-energy X-ray absorptiometry. Four lots of 93-day-old female Wistar rats were studied. A control group of 30 rats were not manipulated (Zn– Ex– group). The experimental group of 40 rats was fed a diet supplemented with an additional 20% of Zn/kg of feed; this group was divided into two groups of 20 rats each, one that did not exercise (Zn+ Ex–) and one that did (Zn+ Ex+). A group of 15 rats exercised but did not receive a zinc supplement (Zn– Ex+ group). Training consisted of treadmill running for 5 out of 7 days over an 11-week period. Initial speed, running time, and treadmill speed were increased gradually. Analysis of variance with the Bonferroni/Dunn test showed that the length, weight, bone mineral content (BMC), and bone mineral density (BMD) of the femur were less in the Zn– Ex+ group than in the others (p < 0.008), and the weight, BMC, and BMD of the fifth lumbar vertebra also were lower in the Zn– Ex+ group than in the others (p < 0.008). These findings confirm the adverse effects of strenuous exercise (treadmill running) on bone tissue in rats and the effectiveness of zinc supplementation in preventing it.
Prostaglandin E2 Induces Expression of Receptor Activator of Nuclear Factor–κB Ligand/Osteoprotegrin Ligand on Pre-B Cells: Implications for Accelerated Osteoclastogenesis in Estrogen Deficiency
Authors: Kanematsu Masahiro , Sato Takuya , Takai Hiroyuki , Watanabe Ken , Ikeda Kyoji , Yamada Yoshiji
Published: April 2006

Estrogen deficiency causes bone loss as a result of accelerated osteoclastic bone resorption. It also has been reported that estrogen deficiency is associated with an increase in the number of pre-B cells in mouse bone marrow. The present study was undertaken to clarify the role of altered B lymphopoiesis and of the receptor activator of nuclear factor-κB ligand (RANKL), a key molecule in osteoclastogenesis, in the bone loss associated with estrogen deficiency. In the presence of prostaglandin E2 (PGE2), the activity to form tartrate-resistant acid phosphatase (TRAP)-positive osteoclast-like cells was significantly greater in bone marrow cells derived from ovariectomized (OVX) mice than in those from sham-operated mice. Northern blot analysis revealed that PGE2 increased the amount of RANKL messenger RNA (mRNA) in bone marrow cells, not only adherent stromal cells but nonadherent hematopoietic cells; among the latter, RANKL mRNA was more abundant in OVX mice than in sham-operated mice and was localized predominantly in B220+ cells. Flow cytometry revealed that most B220+ cells in bone marrow were RANKL positive and that the percentage of RANKL-positive, B220low cells was higher in bone marrow from OVX mice than in that from sham-operated mice. The increase in the expression of RANKL and the percentage of these cells in OVX mice was abolished by the administration of indomethacin in vivo. PGE2 also markedly increased both the level of RANKL mRNA and cell surface expression of RANKL protein in the mouse pre-B cell line 70Z/3. Finally, osteoclastogenic response to PGE2 was reduced markedly by prior depletion of B220+ cells, and it was restored by adding back B220+ cells. Taken together with stimulated cyclo-oxygenase (COX)-2 activity by tumor necrosis factor α (TNF-α) and interleukin-1 (IL-1) in estrogen deficiency, these results suggest that an increase in the number of B220+ cells in bone marrow may play an important role in accelerated bone resorption in estrogen deficiency because B220+ cells exhibit RANKL on the cell surface in the presence of PGE2, thereby leading to accelerated osteoclastogenesis.
Intestinal Calcium Transporter Genes Are Upregulated by Estrogens and the Reproductive Cycle Through Vitamin D Receptor-Independent Mechanisms
Authors: Van Cromphaut SJ , Rummens K , Stockmans I , Van Herck E , Dijcks FA , Ederveen Agh , Carmeliet P , Verhaeghe J , Bouillon R , Carmeliet G
Published: April 2006

1α,25(OH)2-vitamin D strongly regulates the expression of the epithelial calcium channel CaT1. CaT1 expression is reduced in ERKOα mice and induced by estrogen treatment, pregnancy, or lactation in VDR WT and KO mice. Estrogens and vitamin D are thus independent potent regulators of the expression of this calcium influx mechanism, which is involved in active intestinal calcium absorption.

Introduction: Active duodenal calcium absorption consists of three major steps: calcium influx into, transfer through, and extrusion out of the enterocyte. These steps are carried out by the calcium transport protein 1 (CaT1), calbindin-D9K, and the plasma membrane calcium ATPase (PMCA1b), respectively. We investigated whether estrogens or hormonal changes during the female reproductive cycle influence the expression of these genes, and if so, whether these effects are vitamin D-vitamin D receptor (VDR) dependent.

Materials and Methods: We evaluated duodenal expression patterns in estrogen receptor (ER)α and -β knockout (KO) mice, as well as in ovariectomized, estrogen-treated, pregnant, and lactating VDR wild-type (WT) and VDR KO mice.

Results: Expression of calcium transporter genes was not altered in ERKOβ mice. CaT1 mRNA expression was reduced by 55% in ERKOα mice, while the two other calcium transporter genes were not affected. Ovariectomy caused no change in duodenal expression pattern of VDR WT and KO mice, whereas treatment with a pharmacologic dose of estrogens induced CaT1 mRNA expression in VDR WT (4-fold) and KO (8-fold) mice. Pregnancy enhanced CaT1 expression equally in VDR WT and KO mice (12-fold). Calbindin-D9K and PMCA1b expression increased to a lesser extent and solely in pregnant VDR WT animals. In lactating VDR WT and KO mice, CaT1 mRNA expression increased 13 times, which was associated with a smaller increase in calbindin-D9K protein content and PMCA1b mRNA expression.

Conclusions: Estrogens or hormonal changes during pregnancy or lactation have distinct, vitamin D-independent effects at the genomic level on active duodenal calcium absorption mechanisms, mainly through a major upregulation of the calcium influx channel CaT1. The estrogen effects seem to be mediated solely by ERα.
Distribution of Collagen Cross-Links in Normal Human Trabecular Bone
Authors: Paschalis EP , Recker R , Dicarlo E , Doty SB , Atti E , Boskey AL
Published: April 2006

Infrared imaging analysis of normal human iliac crest biopsy specimens shows a characteristic spatial variation in the nonreducible:reducible collagen cross-links at trabecular surfaces, depending on the surfaces' metabolic status.

Introduction: Bone is a composite material consisting of mineral, collagen, non-collagenous proteins, and lipids. Bone collagen, mainly type I, provides the scaffold on which mineral is deposited and imparts specific mechanical properties, determined in part by the amount of collagen present, its orientation and fibril diameter, and the distribution of its cross-links.

Materials and Methods: In this study, the technique of Fourier transform infrared imaging (FTIRI) was used to determine the ratio of nonreducible:reducible cross-links, in 2- to 4-μm-thick sections from human iliac crest biopsy specimens (N = 14) at trabecular surfaces as a function of surface activity (forming versus resorbing), with an ∼6.3-mm spatial resolution. The biopsy specimens were obtained from patients devoid of any metabolic bone disease based on histomorphometric and bone densitometric parameters.

Results and Conclusions: Distributions of collagen cross-links within the first 50 mm at forming trabecular surfaces demonstrated a progressive increase in the nonreducible:reducible collagen cross-link ratio, unlike in the case of resorbing surfaces, in which the collagen cross-links ratio (as defined for the purposes of the present report) was relatively constant.
Patient-Specific DXA Bone Mineral Density Inaccuracies: Quantitative Effects of Nonuniform Extraosseous Fat Distributions
Authors: Bolotin Hh , Sievänen H , Grashuis Jl
Published: April 2006

Nonuniform extraosseous fat is shown to raise the magnitude of inaccuracies in DXA in vivo BMD measurements into the range of 20-50% in clinically relevant cases. Hence, DXA-based bone fragility diagnoses/prognoses and evaluations of bone responsiveness to treatment can be unreliable.

Patient-specific DXA in vivo bone mineral areal density (BMD) measurements have been demonstrated to be inherently inaccurate even when extraosseous fat (F) and lean muscle tissue (L) are uniformly distributed throughout the scan region of interest (ROI). The present work extends these investigations to quantitative evaluation of the extent to which clinically realistic soft tissue inhomogeneities external to the bone within the DXA scan ROI affect patient-specific in vivo BMD measurement inaccuracies. The results are particularly relevant to patient-specific lumbar vertebral and proximal femoral sites. Norland, Hologic, and Lunar DXA scans and corresponding DXA simulation studies of the same set of 225 different phantom arrays were carried out. The phantoms were specially fabricated absorptiometric replications of bone mineral material (B), red marrow (RM), and yellow marrow (YM) mixtures, and extraosseous F and L combinations spanning the anthropometric ranges encountered clinically. The three different DXA scanners yielded BMD results that effectively coincided, were in excellent agreement with the findings of the present corresponding DXA-simulation studies in each case, and confirmed the validity of the DXA BMD inaccuracy analysis formalism. It was found that only relatively small extraosseous soft tissue inhomogeneities within the ROI of DXA BMD scans can increase substantially the already sizable BMD inaccuracies shown earlier to pertain for uniformly distributed extraosseous soft tissues. The extent of these in vivo BMD inaccuracies (%) are shown to depend on the mean extraosseous F-to-L areal density ratio and its degree of nonuniformity within the local bone scan ROI, the marrow thickness and specific composition, and the actual BMD in any given case. It was found that patient-specific DXA-measured in vivo BMD inaccuracies can, in many clinically encountered cases, be as large as 20-50%, particularly so for osteopenic, osteoporotic, and elderly patients. It is concluded that, because these DXA in vivo BMD inaccuracies are unavoidable and clinically unpredictable, diagnoses/prognoses of bone fragility and evaluations of bone responsiveness to treatment of individual patients based mainly on DXA in vivo BMD measurements can be unreliable.
Integrated Single-Label Liquid-Phase Assay of APOE Codons 112 and 158 and a Lipoprotein Study in British Women,
Authors: Abdollahi Mohammad Reza , Guthrie Philip AI , Smith George Davey , Lawlor Debbie A , Ebrahim Shah , Day Ian NM
Published: April 2006

Background: Apolipoprotein E (APOE) is an important element of lipid metabolism and, hence, cardiovascular disorders. APOE has 3 main allelic variants: ε3, ε4, and ε2. Of these, ε3 is the most common, followed by ε4 and ε2. The associations of these isoforms with cardiovascular disorders and Alzheimer disease have been widely studied in different populations. Most of the genotyping in these studies has been performed with gel-based methods, which have important limitations, particularly for large epidemiologic studies. We therefore developed an integrated “one-tube” liquid-phase assay.

Methods: To measure APOE isoforms, we developed an integrated single-label liquid-phase fluorescence assay containing 2 PCR primers, 2 probes, and 2 quencher oligonucleotides. We used a 384-well LightTyper, but the assay would be generically applicable for use with any fluorescence detector with thermal ramp control. We validated this method and applied it in the British Women’s Heart and Health Study.

Results: There were 4 melting peaks, at 41, 56, 61, and 69 °C, which generated 6 distinctive patterns representing genotypic combinations of ε3, ε4, and ε2. The magnitude and direction of the associations found with total cholesterol, HDL-cholesterol, triglycerides, and estimated LDL-cholesterol were consistent with previous reports.

Conclusion: The one-tube LightTyper assay presented here enables accurate, convenient, and economical genotyping of APOE and can be used for large epidemiologic studies.
Frames, schemata, and news reporting
Authors: Scheufele Bertram
Published: April 2006

This article deals with frames and schemata in news reporting. It distinguishes frames and schemata in newsroom discourse and news reports. On the individual cognitive level, a frame is defined as a set of schemata for different aspects of reality. They emerge in newsroom discourse and in exchange with other (media) discourses, i. e., they are not idiosyncratic but shared among those working in a newsroom. It is supposed that news report structures (media frames) correspond to these newsroom frames and schemata. The article discusses these considerations in regard to related explanations of news production, especially attitudinal approaches such as news bias. While the latter assume that journalists prefer information consistent with their own attitudes or that news reporting is ‘synchronized’ with editorial tendencies, the framing approach proposes that information in routine news reports correspond to newsroom frames. In this study I will use xenophobia as an example to identify newsroom frames in a qualitative frame analysis. In the second part of the study, quantitative analysis of news framing examines whether news report information correlates with newsroom frames. Finally, I will present empirical evidence that shows that newsroom frames play a role in news reporting.
Das „Wundergas“ Helium, die US-amerikanische Innenpolitik und die deutschen Zeppeline
Authors: Braun Helmut
Published: April 2006

Vorspann

Dass es in der Rüstungstechnik ganz bestimmte Schlüsseltechnologien gibt, die über das Technische hinaus eine unabsehbare militärische und politische Wirkung entfalten, ist in der zweiten Hälfte des 20. Jahrhunderts ein bekanntes Phänomen. Dieser Artikel erinnert daran, dass es sich hier nicht um eine Erscheinung aus der Zeit nach 1945 handelt. Am Beispiel eines Naturprodukts, des Edelgases Helium, wird vorgeführt, welche technischen und politischen Folgen die Entdeckung dieses chemischen Elements hatte. Aber nicht nur das. Dieser Artikel vermittelt auch eine Vorstellung davon, wie schnell die Rüstungstechnik in 20 Jahren veralten konnte.
Stalins Aufrüstungsbeschluß. Die Moskauer Beratungen mit den Parteichefs und Verteidigungsministern der „Volksdemokratien“ vom 9. bis 12. Januar 1951
Authors: Wettig Gerhard
Published: April 2006

Vorspann

Ein weltgeschichtliches Ereignis wie der Kalte Krieg hat viele Väter. Doch ist wie immer auch hier die Verantwortung unterschiedlich verteilt. Stalins Beitrag zur Genese jener langen und tiefgreifenden Konfrontation zwischen Ost und West scheint besonders groß. Das jedenfalls bleibt als Eindruck dieses einzigartigen Schlüsseldokuments. Im Januar 1951 initiierte der sowjetische Diktator in seinem gesamten Machtbereich ein Aufrüstungsprogramm, wie es in der Zeit nach dem Zweiten Weltkrieg bislang ohne Beispiel war und mit dem er zugleich die sowjetische Macht in Ost- und Mitteleuropa noch stärker verankerte.
Rastreamento gênico da neoplasia endócrina múltipla tipo 2: experiência da Unidade de Endocrinologia Genética da USP
Authors: Santos Marcelo A.C.G. dos , Nunes Adriana Bezerra , Abelin Neusa , Ezabella Marilza C.L. , Toledo Rodrigo de Almeida , Lourenço Júnior Delmar , Hayashida Cesar Yoiti , Fonseca Ivone Izabel M. da , Toledo Sergio P. de Almeida
Published: April 2006

A neoplasia endócrina múltipla tipo 2 (NEM-2) é uma síndrome tumoral hereditária que compreende: carcinoma medular de tireóide, hiperparatiroidismo primário, feocromocitoma e outras doenças não-endócrinas. Desde a identificação das primeiras mutações missense no RET associadas ao NEM-2, a detecção de mutações no RET adquiriu grande impacto no tratamento clínico da NEM-2, tais como o pronto diagnóstico e tratamento do CMT. Atualmente a tireoidectomia total possibilita real cura dos casos de CMT nos quais os diagnósticos moleculares foram efetuados precocemente. Depois de identificadas as mutações no RET, os demais familiares devem ser rastreados para esta mutação utilizando-se métodos como DGGE, SSCP, enzima de restrição, seqüenciamento e mini-seqüenciamento gênico. Apresentamos uma breve revisão da nossa experiência com seqüenciamento gênico direto do RET e DGGE. Em 50 pacientes com NEM-2 analisados por ambas as técnicas, não encontramos falsos resultados, sugerindo que o DGGE é uma metodologia de rastreamento adequada para mutações no proto-oncogene RET.
Alterações morfológicas e funcionais cardíacas e análise dos fatores determinantes de hipertrofia ventricular esquerda em 40 pacientes com acromegalia
Authors: Casini Alessandra Ferri , Araújo Paula Bruna , Fontes Rosita , Xavier Sérgio Salles , Gadelha Mônica R.
Published: April 2006

A acromegalia é uma doença de alta mortalidade, especialmente em razão de complicações cardiovasculares. Com o objetivo de avaliar os fatores determinantes da hipertrofia ventricular esquerda (HVE) e as alterações cardíacas na acromegalia, analisamos 40 acromegálicos submetidos a exames clínico-laboratoriais e ao ecocardiograma. As variáveis analisadas foram idade, sexo, duração de doença, hipertensão arterial (HA), intolerância à glicose/DM, uso ou não de octreotide, GH e %IGF-I. Na análise univariada, pacientes com HVE foram mais idosos (p= 0,031), apresentaram maior prevalência de HA (p= 0,009) e maiores valores da %IGF-I (p= 0,002), comparados aos sem HVE. Na análise multivariada, HA e %IGF-I foram determinantes de HVE (p= 0,035 e p= 0,016). Após a dicotomização da %IGF-I, foi criado um escore e a freqüência de HVE foi 9%, 65%, 92% x 0, 1, 2; p< 0,0001. Encontramos uma prevalência de ectasia de aorta maior e de doença valvar menor do que a da literatura. Concluímos que HA e %IGF-I foram determinantes de HVE.
Alguns dados bioecológicos de Pomacea haustrum (Reeve, 1856), predador-competidor de hospedeiros intermediários de Schistosoma mansoni Sambon, 1907
Authors: Milward-de-Andrade Roberto , Carvalho Omar dos Santos , Guimarães Carlos Tito
Published: April 2006

Foram feitas observações no laboratório e no campo, em Belo Horizonte, MG, Brasil, com a finalidade de se obter informações biológicas e ecológicas sobre Pomacea haustrum (Reeve, 1856), molusco pilídeo, competidor-predador de hospedeiros intermediários de Schistosoma mansoni Sambon 1907.
Estudo da adequação da "Escala de Maturidade Mental Columbia" na avaliação de pré-escolares de baixo nível sócio-econômico
Authors: Fernandes José , Pullin Aurora Coelho
Published: April 2006

A Escala da Maturidade Mental Colúmbia (EMMC) foi aplicada a 93 crianças pré-escolares de 4 a 6 anos, da cidade de Leme, SP (Brasil). Estas crianças eram originárias de famílias de baixo nível sócio-econômico e não freqüentavam nenhum tipo de creche ou pré-escola. Os dados obtidos mostraram que a EMMC apresentou diversas limitações, entre elas, uma diminuição sistemática nos valores do QI de razão, em função do aumento da idade da criança. A ocorrência generalizada de seqüências de respostas com perseveração de posição sugeriu que a situação de teste pode induzir uma queda na motivação e atenção da criança. Dessa forma, os baixos resultados obtidos com a EMMC podem não refletir necessariamente "deficiências cognitivas", mas um baixo interesse da criança em relação às tarefas exigidas pelo teste.
A comparative study of severe scorpion envenomation in children caused by Tityus bahiensis and Tityus serrulatus
Authors: Bucaretchi Fábio , Baracat Emílio CE , Nogueira Roberto J.N. , Chaves Aniel , Zambrone Flávio A.D. , Fonseca Márcia R.C.C. , Tourinho Francis S
Published: April 2006

From January 1984 to May 1994, 17 of 239 children under 15 years old stung by Tityus serrulatus (15.1%) or Tityus bahiensis (84.9%) presented severe envenoming. Of these 17 patients (1-11 years old; median=2 yr) 14 were stung by T.serrulatus and three by T.bahiensis. All of them received scorpion antivenom i.v. at times ranging from 45 min. to 5 h after the accident (median=2h). On admission, the main clinical manifestations and laboratory and electrocardiographic changes were: vomiting (17), diaphoresis (15), tachycardia (14), prostration (10), tachypnea (8), arterial hypertension (7), arterial hypotension (5), tremors (5), hypothermia (4), hyperglycemia (17), leukocytosis (16/16), hypokalemia (13/17), increased CK-MB enzyme activity (>6% of the total CK, 11/12), hyperamylasemia (11/14), sinusal tachycardia (16/17) and a myocardial infarction-like pattern (11/17). Six patients stung by T.serrulatus had depressed left ventricular systolic function assessed by means of echocardiography. Of these, five presented pulmonary edema and four had shock. A child aged two-years old presented severe respiratory failure and died 65 h after being stung by T.serrulatus. Severe envenomations caused by T.serrulatus were 26.2 times more frequent than those caused by T.bahiensis (p<0.001).
Clinical and endoscopic findings in the mucosae of the upper respiratory and digestive tracts in post-treatment follow-up of paracoccidioidomycosis patients
Authors: Valle Antonio Carlos Francesconi do , Aprigliano Filho Flavio , Moreira João Soares , Wanke Bodo
Published: April 2006

Systematic examination of the upper respiratory and digestive tracts (URDT) was performed in a group of 80 paracoccidioidomycosis (PCM) patients submitted to post-treatment follow-up ranging from 8 months to 17 years. Mucosae of the URDT had been involved prior to specific treatment in 74 patients, distributed as follows: oropharynx, 50 (41 alone, 7 in association with the larynx, and 2 with the nasal mucosa); larynx, 30 (23 alone and 7 in association); and nasal mucosa, 3(1 alone and 2 in association). Inactive lesions were observed in all the 50 patients with lesions of the oropharynx, 3 of whom with deforming scars (1 with retraction of the tongue and 2 with narrowing of the oral orifice). One case presented a destructive lesion, with perfuration of the palate. Of the other 46 cases, examination showed nacreous white striated scars which were nearly imperceptible in some cases and in others displayed partial retraction of anatomical structures without any alteration of their features. Patients presented a high rate of missing teeth. In 3 patients with involvement of the nasal mucosa, none of whom presented active PCM lesions, 2 still had nasal voices. In 30 patients with lesions of the larynx, 1 suffered a relapse of PCM and 2 developed epidermoid carcinoma. Of the other 27 cases, none of whom had active PCM lesions, 15 presented dysphonia, 3 were tracheotomized, and 9 were asymptomatic.
The value of adenosine deaminase (ADA) determination in the diagnosis of tuberculous ascites
Authors: Brant Cesar Q. , Silva Jr. Mario R. , Macedo Erica P. , Vasconcelos Claudio , Tamaki Natalina , Ferraz M. Lucia G.
Published: April 2006

In order to evaluate the role of the determination of adenosine deaminase activity (ADA) in ascitic fluid for the diagnosis of tuberculosis, 44 patients were studied. Based on biochemical, cytological, histopathological and microbiological tests, the patients were divided into 5 groups: G1 - tuberculous ascites (n = 8); G2 - malignant ascites (n = 13); G3 - spontaneous bacterial peritonitis (n = 6); G4 - pancreatic ascites (n = 2); G5 - miscelaneous ascites (n = 15). ADA concentration were significantly higher in G1 (133.50 ± 24.74 U/l) compared to the other groups (G2 = 41.85 ± 52.07 U/l; G3 = 10.63 ± 5.87 U/l; G4 = 18.00 ± 7.07 U/l; G5 = 11.23 ± 7.66 U/l). At a cut-off value of >31 U/l, the sensitivity, specificity and positive and negative preditive values were 100%, 92%, 72% and 100%, respectively. ADA concentrations as high as in tuberculous ascites were only found in two malignant ascites caused by lymphoma. We conclude that ADA determination in ascitic fluid is a useful and reliable screening test for diagnosing tuberculous ascites. Values of ADA higher than 31 U/l indicate more invasive methods to confirm the diagnosis of tuberculosis.
Autoantibodies before, during and after administration of recombinant interferon-alpha for chronic viral hepatitis
Authors: Lopes Edmundo P.A. , Silva A. Eduardo , Sette Junior Hoel , Guimarães Rubens X. , Ferraz M. Lucia
Published: April 2006

This study was undertaken to investigate the presence of autoantibodies in patients with chronic viral hepatitis B and C, before, during and after interferon-alpha (IFN-alpha) therapy and to study their relation to dose and type of IFN-alpha and response to treatment. Fifty patients with chronic hepatitis were divided in two groups, a control-group of 21 patients (10 type B and 11 type C) who were followed for 6 months without treatment and an IFN-group consisting of 29 patients (8 type B and 21 type C) who received IFN therapy for 6 months. Serum samples were tested for a range of antibodies at the start of the study, during therapy and at the end of the 6 month period. Antibodies tested for included: antinuclear, smooth muscle, antimitochondrial, parietal cell and thyroid microsomal. Four (8%) of the total patient group had autoantibodies at the beginning of the study (two in each group). During the follow-up period no patient in the control group developed antibodies compared with 3 (11%) patients in the treatment group. Autoantibodies developed in patients treated with higher doses of IFN and were found in those patients who tended to show a poor response to IFN-therapy. Further studies are needed to establish the relationship between poor response to IFN-alpha and development of autoantibodies.
Is CK-MB isoenzyme useful for diagnosis of cardiac involvement in icteric leptospirosis?
Authors: Machado Elizabeth Stankiewicz , Feres José Guilherme de Faria , Feijó Luis Augusto , Andrade Jarbas , Nogueira Susie Andries
Published: April 2006

In the absence of heart failure or cardiogenic shock, cardiac involvement diagnosis in icteric leptospirosis is possible on the basis of abnormal electrocardiograms. As metabolic and electrolytic disorders are frequently seen during acute leptospirosis infection, they may be responsible for some electrocardiograms changes. We conducted a study to assess if creatine phosphokinase isoenzyme determinations are useful in selecting patients with a high cardiac involvement suspicion. Sixty-nine patients were studied prospectively. Ten patients out of 16 with cardiac involvement and 25 without had high CK-MB levels (p>0.05), although mean values of abnormal CK-MB levels were higher in the group with cardiac involvement (p<0.05). Our analysis indicates that serum CK-MB determination does not provide a specific indicator of myocardial involvement in the course of icteric leptospirosis.
The relevance of laboratory diagnosis of human cryptosporidiosis and other coccidia
Authors: Garlipp C.R. , Bottini P.V. , Teixeira A.T.L.S.
Published: April 2006

Human infection by Cryptosporidium spp and other coccidia are due to opportunist non-host specific microorganisms. In HIV seropositive patients, the gastrointestinal symptoms accompanying such infections may be serious and prolonged and may include nausea, low-grade fever, abdominal cramps, anorexia and watery diarrhoea. We studied 188 stool samples from 111 patients (84 men and 27 women) with diarrhoea. A modified Ziehl-Nielsen technique for the detection of Cryptosporidium spp and Isospora belli was employed. The mean age of the patients was 31 years. Cryptosporidium spp was seen in 18% (n=20) of the patients, 90% (n=18) of whom were HIV seropositive. Isospora belli was recorded only from HIV seropositive patients (5.4% of all the patients studied and 6.5% of those who were HIV seropositive). These data confirm the good results obtained with this technique for the identification of Cryptosporidium spp and other coccidia and also reaffirm the clinical importance of correctly diagnosing the cause of diarrhoea, particularly in HIV seropositive patients.
Floristic, edaphic and structural characteristics of flooded and unflooded forests in the lower Rio Purús region of central Amazonia, Brazil
Authors: Haugaasen Torbjørn , Peres Carlos Augusto
Published: April 2006

Despite a natural history interest in the early 1900s, relatively little ecological research has been carried out in the Rio Purús basin of central Amazonia, Brazil. Here we describe a new study area in the region of Lago Uauaçú with an emphasis on the climate, forest structure and composition, and soil characteristics between adjacent unflooded (terra firme) and seasonally inundated forests; situated within both the white-water (várzea) and black-water (igapó) drainage systems that dominate the landscape. The climate was found to be typical of that of the central Amazon. Várzea forest soils had high concentrations of nutrients, while terra firme and igapó soils were comparatively nutrient-poor. Terra firme forests were the most floristically diverse forest type, whereas várzea was intermediate, and igapó the most species-poor. The Lecythidaceae was the most important family in terra firme while the Euphorbiaceae was the most important in both várzea and igapó. There were significant differences between forest types in terms of number of saplings, canopy cover and understorey density. In contrasting our results with other published information, we conclude that the Lago Uauaçú region consists of a typical central Amazonian forest macro-mosaic, but is a unique area with high conservation value due to the intimate juxtaposition of terra firme, várzea and igapó forests.
Sinopse das espécies de Marlierea Cambess. (Myrtaceae) na Amazônia brasileira
Authors: Rosário Alessandro Silva do , Secco Ricardo de S.
Published: April 2006

O estudo de Marlierea Cambess. na Amazônia Brasileira tem como principal objetivo atualizar os dados sobre a morfologia e taxonomia das espécies da região, bem como fornecer subsídios para esclarecer a separação de Marlierea de Myrcia DC. ex Guill., conforme sugerem alguns autores. Na Amazônia Brasileira, Marlierea está representada por 11 espécies (Marlierea bipennis (O. Berg) McVaugh, M. caudata McVaugh, M. ensiformis McVaugh, M. ferruginea (Poir.) McVaugh, M. mcvaughii B. Holst, M. scytophylla Diels, M. spruceana O. Berg, M. subulata McVaugh, M. summa McVaugh, M. umbraticola (Kunth) O. Berg e M. velutina McVaugh) e uma mal conhecida (M. obumbrans (O. Berg) Nied.), habitando principalmente áreas de formações florestais. O gênero se caracteriza pelo hábito arbóreo ou arbustivo; folhas opostas (exceto em M. velutina que pode apresentar folhas opostas e/ou alternas); as inflorescências em panículas (de fascículos), racemos, cimeiras ou dicásios; botões florais geralmente fechados, abertura irregular do cálice, em 4-5 lobos, pétalas freqüentemente ausentes. Os Estados do Amazonas e Pará representam os dois principais centros de distribuição dessas espécies, sendo M. spruceana e M. umbraticola as espécies mais comuns. Marlierea obumbrans será melhor estudada posteriormente, devido apresentar sua delimitação taxonômica confusa entre Myrcia e Marlierea.
Três novas espécies de abelhas da Amazônia pertencentes ao gênero Eulaema (Hymenoptera: Apidae: Euglossini)
Authors: Oliveira Marcio Luiz de
Published: April 2006

Eulaema (Apeulaema) pseudocingulata sp. n., semelhante a E. (A.) cingulata (Fabricius, 1804) e com distribuição pela Amazônia e planalto das Guianas; Eulaem a (Eulaema) parapolyzona sp. n., semelhante a Eulaema (Eulaema) polyzona (Mocsáry, 1897) e exclusiva da Amazônia ocidental, e Eulaema (Eulaema) napensis sp. n., endêmica da Amazônia equatoriana são descritas. Uma chave para identificação das espécies do gênero é apresentada.