cssi/SciSciGPT-SciSciNet huggingface dataset:
Infarct size determination by technetium 99m sestamibi single-photon emission computed tomography predicts survival in patients with chronic coronary artery disease ☆

Abstract Background The prognostic value of infarct size quantification by technetium 99m sestamibi single-photon emission computed tomography (SPECT) in patients with chronic coronary artery disease (CAD) has not been established. Methods and Results Between September 1994 and May 1995, 1323 patients with known or suspected CAD were referred for perfusion imaging for clinical reasons and had infarct size determined by quantitative SPECT imaging. Patients underwent exercise stress (61%), pharmacologic stress (37%), and rest imaging (3%). Patients were excluded if they had cardiomyopathy, valvular heart disease, or myocardial infarction within 3 weeks of the SPECT study. There were 1224 patients who formed the study group. Follow-up was 94% complete at a median of 1.9 ± 0.4 years. Sixty-five percent of patients had no measurable infarct. Among the patients with measurable infarcts, the mean infarct size by sestamibi imaging was 15.0% ± 14.5% of the left ventricle (25% of infarcts ≤5% of the left ventricle and 25% of infarcts ≥19% of the left ventricle). By using stepwise regression analysis, age, diabetes, and hypercholesterolemia were all clinical predictors of overall death ( P P =.001) and survival free of cardiac death ( P =.0002). However, when first-pass left ventricular ejection fraction was added to the models, infarct size was no longer significant. Conclusions Infarct size determination by SPECT 99m Tc sestamibi can predict subsequent death in patients with chronic CAD, although ejection fraction appears to have greater prognostic value. (Am Heart J 2000;140:61-6.)
Selected oxidation with dioxygen complexes as intermediates I. Oxidation of coordinated dipeptide ligands

Abstract A study of the reaction mechanism, including determination of the fate of the oxygen and of the coordinated ligands, has been undertaken for dioxygen complexes formed cobalt(II) complexes of several dipeptides. An earlier study has shown that binuclear cobalt dioxygen complexes of dipeptides decompose spontaneously to yield inert cobalt(III) complexes and water, not hydrogen peroxide. Complete reduction of the original bridging dioxygen groups strongly suggests that the coordinated ligand is being oxidized to supply the required electrons. Therefore, the dioxygen complexes formed from glycylglycine (gly-gly), alanylglycine (ala-gly) and glycylalanine (gly-ala) were allowed to react and the reaction stoichiometry was determined by gas chromatographic and mass spectrometric analysis for the reaction products. The results demonstrate that the reaction involves two-electron oxidation of the coordinated dipeptides, and that the ligands are oxidized exclusively at the N -terminal position so as to convert the coordinated amino groups to coordinated imines. Additional spectral and polarographic data on the oxidized coordinated ligands were employed to follow kinetics of their formation and subsequent displacement by additional ligand, and to prove that the oxidation reaction occurs only when the peptide is coordinated to cobalt(III) in the dioxygen complex.
Effects of Estradiol on Pituitary-Adrenal Function in Male and Female Rats

Two weeks after a single injection of polyestradiol phosphate, pituitary weight more than doubled in both male and female rats. Pituitary ACTH content was unchanged in the males but increased 2.5-fold in the female animals. Pituitary RNA and DNA increased in the male rats, whereas only RNA increased in the females. Adrenal weight was increased only in male rats, associated with an increase in adrenal RNA. Adrenal RNA and DNA in female rats were both decreased. Estradiol administration reversed previously reported sex differences in adrenal secretion and peripheral metabolism of corticosterone (Cpd. B). Plasma Cpd. B concentrations after stress or ACTH were increased in treated male rats and unchanged in females. In male animals, estradiol increased hepatic reduction of ring A of Cpd. B in vitro and shortened the biological half-life of Cpd. B in vivo. Converse effects were obtained in females. Following estradiol administration in vivo or after its direct addition in vitro, steroidogenesis was stimulated ...
Mhc class II diversity and balancing selection in greater prairie-chickens

The major histocompatibility complex (Mhc) of domestic chickens has been characterized as small and relatively simple compared with that of mammals. However, there is growing evidence that the Mhc of many bird lineages may be more complex, even within the Order Galliformes. In this study, we measured genetic variation and balancing selection at Mhc loci in another galliform, the greater prairie-chicken. We cloned and sequenced a 239 bp fragment of Mhc Class II β-chain (BLB) exon 2 in 14 individuals. There was a total of 10 unique sequences and a minimum of four BLB loci. The dN/dS ratio at peptide-binding codons was significantly greater than one, suggesting balancing selection is acting on the BLB. We also recovered two YLB sequences, which clustered tightly with YLB sequences from three other species: domestic chicken, black grouse and common quail. The relatively large number of loci revealed in our study suggests that even closely related galliforms differ in the level of Mhc variation and structure.
The Effect of Teaching Experience and Specialty (Vocal or Instrumental) on Vocal Health Ratings of Music Teachers.

The current study sought to determine the relationship among music teachers’ length of teaching experience, specialty (vocal or instrumental), and ratings of behaviors and teaching activities relat...
Responses of Chlamydomonas reinhardtii to peroxyacetyl nitrate.

Abstract Peroxyacetyl nitrate inhibits autotrophic and heterotrophic growth of Chlamydomonas . Experimental results show both photosynthesis and respiration are adversely affected by PAN. Photosynthesis is more severely damaged than is respiration, when measured as percentage of reduction and as the ability to recover after treatment. The presence of white or blue light during treatment enhances the effects of PAN on photosynthesis. Measurable sulfhydryl levels of cells show linear reductions with increasing amounts of PAN applied. Pigment analysis after treatment indicates a differential destruction of the chlorophylls, with chlorophyll b being more stable than chlorophyll a. Carotenoids are also destroyed, commencing with PAN treatment. The pattern of pigment destruction by PAN in whole cells is repeated in vitro , when the pigments in hexane-acetone are treated with PAN. The implications of PAN damage to Chlamydomonas are discussed in view of similar effects on higher plants.
Characterization of soil properties associated with type-I fairy ring symptoms in turfgrass

Fairy ring is a frequently reported disease of turfgrasses worldwide, and necrotic or severely injured grass are observed in those turf sites exhibiting type-I fairy ring symptoms. The objective of this research was to characterize soil chemical and physical properties at two soil sampling depths (0.5 cm and 3.0 cm) at a turfgrass site exhibiting type-I fairy ring symptoms. Soil samples were obtained from a perennial ryegrass (Lolium perenne L.) golf course fairway at one sampling date in the summer when environmental conditions were most conducive to the appearance of severe type-I fairy ring symptoms. At both soil depths, soil analysis indicated that concentrations of ammonium-nitrogen, potassium, and sulfur were statistically higher in soil underlying necrotic or bare zones versus soil in healthy turfgrass zones. At both soil depths, soil electrical conductivity was statistically higher, and volumetric soil water content was statistically lower in necrotic zones versus soil under healthy turfgrass. At both soil depths, total nitrogen, magnesium, calcium, cation exchange capacity, and organic matter content were not statistically different among necrotic and healthy turfgrass zones. Soil pH was statistically higher in the necrotic zone versus soil under healthy turfgrass at only the 3.0 cm soil sampling depth. Comparing soil properties within the necrotic zone, only potassium and electrical conductivity was statistically higher at the 0.5 cm depth compared to the 3.0 cm depth. Although most soil information was considered very similar at both sampling depths, soil sampling at the 3.0 cm depth would be a more practical or easier method for turfgrass managers. At either soil sampling depth, the necrotic zones of type-I fairy ring areas in turfgrass were most likely associated with a combination of direct and indirect effects of the basidiomycete fungi on soil chemical and physical properties in the turfgrass root zone.
Landslide Facies and the Paleoslope in the Catskill Delta: ABSTRACT

Non-red arenaceous strata of the Middle and Upper Devonian Fort Littleton Formation constitute the marine portion of the northern flank of the Catskill delta in Pennsylvania and New York. Lithostratigraphic units within the Fort Littleton thicken and become coarser toward the source in the south-southeast; laterally equivalent lower redbeds of the Catskill Formation occupy successively lower stratigraphic positions in the same direction. Submarine landslide deposits in the upper several hundred feet of the Fort Littleton below the redbeds consist of transported load-structures and angular blocks up to twelve feet long. The base of the landslide facies roughly marks the position of the foot of the paleoslope, that is, the juncture of rocks deposited on unstable slopes with undisturbed strata of the floor environment. Like the base of the Catskill facies, the landslide facies occurs at progressively lower positions toward the south-southeast and, in turn, is laterally equivalent to the distal floor facies, which is End_Page 340------------------------------ devoid of landslide structures. Regional variation in stratigraphic position of the base of the landslide facies established the fact that the foot of the paleoslope migrated north-northwestwardly through time. In strata of the landslide facies, directional-current structures show transport from south to north whereas rocks of the floor facies display evidence of paleocurrents moving from east to west, suggesting that gravity-driven paleocurrents were deflected by velocity loss from northwardly to westwardly flow at the foot of the paleoslope. Distinctive siltstones were deposited by the deflected currents against the foot of the paleoslope. The landslide facies is characterized by landslide deposits, reddish and greenish colors, subgraywackes, conglomerates, good fissility, fragmental fossils, ripple marks, and load-structures whereas the floor facies is defined by brown and gray colors, graywackes, poor fissility, sole marks, and trace fossils. End_of_Article - Last_Page 341------------
CHRONIC INTRAUTERINE PULMONARY HYPERTENSION IMPAIRS NORMAL DEVELOPMENT OF ENDOTHELIAL NITRIC OXIDE SYNTHASE PROTEIN AND ACTIVITY IN THE OVINE FETUS. • 2108

Endogenous production of nitric oxide (NO) by the endothelial Ca2+-dependent NO synthase (eNOS) seems to be developmentally regulated in the pulmonary vasculature. Whether decreased production or activity of endogenous NO contributes to sustained elevations of pulmonary vascular resistance (PVR) and the failure of postnatal adaptation in persistent pulmonary hypertension of the newborn (PPHN) is unknown. In the present work we measured eNOS protein content and NOS activity in lungs from normal fetal, newborn and adult lambs. The same measurements were made in animals subjected to a model of perinatal pulmonary hypertension caused by intrauterine compression of the ductus arteriosus (DA), performed between 125-128 days of gestation (147 days, term), and maintained for 9-13 days. The eNOS protein expression, as determined by western blot analysis, increased 2.23 fold between 0.53 and 0.95 term, and maintained in the postnatal animals. Ca2+-dependent NOS activity, as determined by L-14C-arginine to14 C-citrulline conversion assay, increased 6.9 fold between 0.53 and 0.95 term (P < 0-.01) and 3.48 fold between 0.95 term and newborn animals(P < 0.01). No differences were observed in NOS activity between newborn and adult lambs. After chronic intrauterine pulmonary hypertension, eNOS immunostaining demonstrated persistent presence of eNOS protein. However, the protein expression was reduced by 48 ± 4%, and Ca2+-dependent NOS activity was decreased by 23.15 ± 12.3% (P < 0.01 vs. age-matched controls). We conclude that chronic pulmonary hypertension impairs the normal development of eNOS protein expression and activity in late-gestation fetal lambs. We speculate that decreased NO production contributes to altered pulmonary vasoreactivity in utero, sustained elevation of PVR at delivery, and perhaps hypertensive structural changes in small pulmonary arteries in experimental PPHN.
What can be expected from a late cochlear implantation

Summary Objective Verify if late cochlear implantation allows pre-lingual deafs to convert from visual to oral communication mode only. Method Thirteen pre-lingual profoundly deaf patients implanted the ages of 8 and 22 years were included in the study. Before cochlear implantation, none of the patients used the oral language. Six patients used cued speech and seven used the sign language to communicate. Evaluations were made with measures of hearing thresholds, phoneme identification, categories of auditory performance and rating of the intelligibility of speech before and after implantation. Changes in principal mode of communication (i.e. oral, cued speech or sign language) were also monitored. Results The former users of cued speech benefited significantly more from cochlear implantation than the sign language users for phoneme identification and categories of auditory performance, although all had similar hearing thresholds before and after cochlear implantation. After a mean implant use of 4.5 years, four out of six cued speech users converted to exclusive use of the oral language, while only one out of seven former users of the sign language converted to the use of the oral language. Discussion It is possible for pre-lingual or congenital deafs to convert totally from a visual to an oral communication mode even in case of late cochlear implantation. Previous awareness of the structure of the oral language, even without hearing (e.g. via cued speech) influences positively the outcome of delayed implantations. We recommend the adoption of oral communication with the cued speech code in cases where a late cochlear implantation is envisioned.
Interpreting Strategic Issues: Effects of Strategy and the Information-Processing Structure of Top Management Teams

Understanding how managers interpret strategic issues is important to understanding strategic action, organizational change, and learning. However, little is known about how the context in which st...
Same As It Ever Was: Nuclear Alarmism, Proliferation, and the Cold War

A widely held and largely unchallenged view among many scholars and policymakers is that nuclear proliferation is the gravest threat facing the United States today, that it is more dangerous than ever, and that few meaningful lessons can be drawn from the nuclear history of a supposed simpler and more predictable period, the Cold War. This view, labeled “nuclear alarmism,” is based on four myths about the history of the nuclear age. First, today's nuclear threats are new and more dangerous than those of the past. Second, unlike today, nuclear weapons stabilized international politics during the Cold War, when in fact the record was mixed. The third myth conflates the history of the nuclear arms race with the geopolitical and ideological competition between the Soviet Union and the United States, creating an oversimplified and misguided portrayal of the Cold War. The final myth is that the Cold War bipolar military rivalry was the only force driving nuclear proliferation. A better understanding of this his...
Screening a novel class of anticoagulants for multi‐organ toxicity using Fischer 344 rats: involvement of clinical and anatomic pathologists in the early drug development process

Background: Veterinary clinical and anatomic pathologists play a critical role in assessing the safety of new molecules. The process for evaluation of candidate molecules in drug discovery may vary markedly, depending on the unique characteristics of the compound class. Objectives: The goal of this report is to describe the evaluation process for assessing the potential toxicity of 2 anticoagulant compounds that were representative of molecules tested in early screening studies in Fisher rats, and to use these studies as an example of the strategic approach used by veterinary pathologists in pharmaceutical safety assessment. Methods: Groups of 3 rats were given vehicle alone or one of several doses of compound A or B by oral gavage daily for 4 consecutive days. Survival; clinical signs; body and organ weight measurements; hematologic, coagulation, and clinical biochemical testing; and gross and histologic findings at necropsy were assessed. Transmission electron microscopy was used to characterize unique findings in the liver of rats treated with compound B. Results: Both compounds caused dose-dependent prolongation of the prothrombin time (PT), activated partial thromboplastin time (APTT), and thrombin clotting time (TCT). Hepatobiliary and intestinal toxicity were identified by alterations in serum chemistry data, and by histopathologic findings. Electron microscopy and tissue inorganic phosphorus analysis revealed phospholipidosis in rats treated with compound B.Conclusions: Pharmacologically mediated or “on target” effects for these molecules were characterized by dose-progressive prolongation of the PT, APTT, and TCT. Nonpharmacologically mediated or “off-target” toxicity consisted of hepatoxicity and enterotoxicity. These liabilities required that scientists alter the original molecular scaffold to reach the desired therapeutic target and minimize toxicity.
Suppression of intrachannel nonlinear effects in high-speed WDM systems

High-speed optical transmission systems operating at 40 Gb/s or higher are severely limited by intrachannel nonlinearities such as intrachannel four-wave mixing (IFWM) and intrachannel cross-phase modulation (IXPM). Approaches to deal with intrachannel nonlinearities may be classified into three broad categories: modulation formats, constrained (or line) coding, and equalization techniques. The IFWM is a phase-sensitive effect, and the aim of the first approach is to remove the phase short-term coherence of the pulses emitted in a given neighborhood. The role of constrained coding is to avoid those waveforms in the transmitted signal that are most likely to be received incorrectly. In this paper we describe two alternative techniques for suppression of intrachannel nolinearities: (i) constrained coding techniques, and (ii) combined nonlinear ISI cancellation and error control. Three different constrained coding techniques will be presented: (a) the use of constrained encoding itself, (b) combined constrained and error control coding and (c) deliberate error insertion. The nonlinear ISI cancellation scheme employs the maximum a posteriori probability (MAP) symbol decoding based on Bahl-Cocke-Jelinek-Raviv (BCJR) algorithm, while the forward error correction is based on low-density parity-check (LDPC) codes. The nonlinear ISI channel is modeled by a finite state machine (FSM) whose transition and output functions describe the dependency of the channel statistics and the ISI on transmitted patterns. The BCJR algorithm operates on a trellis of the corresponding FSM, and creates the soft information (detected bit likelihoods) used in the iterative decoder. To improve the BER performance of nonlinear BCJR equalizer further, a noise-predictive BCJR equalizer is introduced. The main feature of these schemes is that they can operate in the regime of very strong intrachannel nonlinearities where FEC schemes such as turbo or LDPC codes are not designed to operate.
Improved synthesis of 2′-deoxy-2′-[18F]-fluoro-1-β-d-arabinofuranosyl-5-iodouracil ([18F]-FIAU)

An improved synthesis of 2′-[18F]-fluoro-2′-deoxy-1-β-d-arabinofuranosyl-5-iodouracil ([18F]-FIAU) has been developed. The method utilizes trimethylsilyl trifluoromethanesulfonate (TMSOTf) catalyzed coupling of 2-deoxy-2-[18F]-fluoro-1,3,5-tri-O-benzoyl-d-arabinofuranose with 2,4-bis(trimethylsilyloxy)-5-iodouracil to yield the protected dibenzoyl-[18F]-FIAU. Dibenzoyl-[18F]-FIAU was deprotected with sodium methoxide to yield a mixture of α- and β-anomers in a ratio of 1:1, which were purified by HPLC. The procedure described in this article eliminates the need for HBr activation of the sugar prior to coupling with silylated iodouracil and is suitable for automation. The total reaction time was about 110 min, starting from [18F]-fluoride. The average isolated yield of the required β-anomer was 10±6% (decay corrected) with average specific activity of 125 mCi/μmol.
Semileptonic electroweak interactions with nucleons and nuclei

The basic formalism needed to describe parity-violating electron scattering from nucleons and nuclei is presented and the experiments anticipated in the next few years discussed. The underlying structure of the relevant leptonic and hadronic tensors is developed in some detail for both parity-conserving and -violating situations to highlight the new physics that becomes accessible in the latter case. When applying the basic formalism to specific (practical) examples, the theme of determining the strangeness content of the nucleon is stressed.
Patterns of Juvenile Mortality Within an Oligophagous Insect Population

A 4—yr study was performed on an oligophagous population of the nymphalid butterfly Euphydryas editha. Mortality was measured on all juvenile life stages of the insect. Separate life tables were constructed for individuals associated with each of two host plant species, Collinsia torreyi and Pedicularis semibarbata, and mortality associated with these two species was compared. On average, overall mortality was found to be higher associated with P. semibarbata, which supports previous work that has shown C. torreyi to be the more suitable host plant for E. editha at this site. Other general patterns emerged from a comparison of mortality within instars. Egg and prediapause larval mortality were generally higher associated with P. semibarbata, while pupal mortality was generally higher associated with C. torreyi. Postdiapause larval mortality was extremely variable, and closely tracked levels of parasitism associated with the two host plant species. The data demonstrated considerable variation in mortality,...
A novel noncollagenous protein encoded by an alternative transcript of the chick type III collagen gene is expressed in cartilage, bone and muscle.

We have identified a noncollagenous protein, Col3alt, encoded by an alternative transcript of the chick type III collagen gene; its amino acid sequence is out of frame with the collagen coding sequence. This 178-amino-acid protein is unique and has no recognizable motifs other than a hydrophobic domain. Col3alt is found in embryonic cartilage, muscle and bone and in the proliferative and prehypertrophic zones of juvenile chicken growth plates. The protein is intracellular in immature chondrocytes and myoblasts, but is extracellular in well-differentiated cartilage, muscle and bone, despite the lack of a conventional signal peptide. These results demonstrate an unexpected economy of genome utilization in which a single gene, using alternative promoters, gives rise to two unrelated proteins, type III collagen and Col3alt.
Content Validity of the In-Hand Manipulation Test

Object manipulation skills are a vital area for client assessment in occupational therapy, but in-hand manipulation skills are not specifically included in any standardized tests of hand function for children. The In-Hand Manipulation Test (IMT) was developed for use by occupational therapists with preschool and young school-age children. Assessment of the IMT's content validity was an important precursor to further development of the test. Twenty-four certified occupational therapists rated young children's performance during administration of the IMT before completing a content validity survey about the test. Overall, the IMT's content validity was supported by the feedback from the raters. A final test length of 50 items with two trials per item was considered acceptable, provided that the test takes no longer than 20 to 30 min to administer. The therapists were positive about the content and structure of the rating scale and the approach used in presenting activities to the children. Some issues related to functional validity of some skills or the proportions of in-hand manipulation skills were raised. Further development of the IMT for clinical and research use seems warranted. Revisions to the test will be made, and another pilot study will be conducted before normative data collection. Training for administering and scoring the test will incorporate the recommendations on the basis of this study's results.
Ultrastructure and histochemistry of the metacercarial cyst of Spelotrema nicolli (Microphallidae: Trematoda)

Abstract Based on electron microscopy and histochemical tests, four layers are described for the metacercarial cyst of Spelotrema nicolli . The outermost layer I is made up of host connective tissue. Layer II, which may contain lipid, is a narrow band varying in electron density. Layer III is composed of mucoprotein with a granular fine structure. The innermost layer is made up of columnar, proteinaceous crystals, which radiate out from the inner edge of the cyst. Observations on the epidermis of Spelotrema nicolli contrast previous work on the mechanism of cyst formation in microphallids.
Uncertain price competition in a duopoly: Impact of heterogeneous availability of the commodity under sale

We study price competition in a duopoly with an arbitrary number of buyers. Each seller can offer multiple units of a commodity depending on the availability of the commodity which is random and may be different for different sellers. Each seller seeks to select a price that will be attractive to the buyers and also fetch adequate profits. The selection will in general depend on the number of units available with the seller and also that of its competitor — the seller may only know the statistics of the latter. The setting captures a microgrid network or a Cognitive Radio Network (CRN) in which excess power units and unused spectrum bands constitute the respective commodities of sale. We analyze this price competition as a game. We prove the existence and uniqueness of Nash Equilibrium (NE) in the class of symmetric equilibria, and explicitly compute the price distribution in the NE.
Elastic scattering of 7–9 MeV protons by 89Y

Abstract Measurement and analysis of proton elastic scattering on 89 Y are reported for lab energies of 7.44, 8.08 and 9.01 MeV. The results were analysed with the optical model using the average parameters of Rosen employed for analysis of proton elastic scattering, polarization and reaction cross sections for many nucleides. The fit is satisfactory but is improved by a 2–3 MeV (4–6%) increase of the real central potential and a 1–2 MeV decrease in the imaginary potential. The potential parameters from a best-fit search are also listed.
Autonomous trading agent design in the presence of tradeoffs

In previous work we have introduced a principled methodology for systematically exploring the space of bidding strategies when agents participate in a significant number of simultaneous auctions, and thus finding an analytical solution is not possible. We decompose the problem into sub-problems and then use rigorous experimentation to determine the best partial strategies. In this paper we clarify and extend our methodology. We discuss our agent design for TAC 2003 and furthermore the changes to our agent as a result of the rule changes in TAC 2004. We also present a "full" set of experiments for determining an overall "optimal" strategy in the 2003 and 2004 Trading Agent Competition (TAC). Our agent was created by using the results of this methodology and has consistently been the top-scoring agent in several rounds of the TAC competition.
Approche du mécanisme d'action du bismésilate d'almitrine sur les chémorécepteurs périphériques et les rapports ventilation/perfusion (V̊A/Q̊)

Resume Les etudes de pharmacologie animale ont demontre la stimulation specifique des chemorecepteurs peripheriques par le bismesilate d'almitrine (BMA). Plus recemment, des etudes de pharmacologie clinique ont mis en evidence l'amelioration de la distribution des rapports VA/Q par le BMA. Enfin, faisant le lien entre ces deux constatations une etude realisee chez des sujets chemodenerves montre que la presence des chemorecepteurs peripheriques est indispensable pour que s'exprime l'effet benefique du BMA sur les rapports VA/Q. Des questions restent malgre tout sans reponse: 1. Comment le BMA stimule-t-il les chemorecepteurs arteriels? Les differentes hypotheses qui tentent d'expliciter le processus de stimulation des chemorecepteurs par l'hypoxie ont ete utilisees pour etudier le mecanisme d'action du BMA. A. Intervention de neurotransmetteurs: parmi les catecholamines et neuropeptides presents dans les corps carotidiens, il a ete demontre que le BMA induit une depletion en dopamine et en noradrenaline. B. Hypothese acidique: l'acetazolamide, inhibiteur de l'anhydrase carbonique, diminue transitoirement l'activite chemoreceptrice du BMA. C. L'hypothese metabolique ne semble pas devoir etre retenue, car les taux d'AMP intra-carotidiens ne sont pas modifies. 2. Comment le BMA agit-il sur le rapport VA/Q? • Une redistribution de la ventilation alveolaire peut resulter d'une activite conjointe sur le tonus bronchomoteur et sur les caracteristiques respiratoires a des doses n'augmentant pas la ventilation externe. • La distribution de la perfusion sanguine pulmonaire a ete etudiee par des essais d'antagonisme de l'effet vasomoteur pulmonaire: contrairement a ce qui avait ete observe chez le chien, la chemodenervation et le pre-traitement par la phentolamine chez le rat diminue l'activite du BMA suggerant que cette derniere a une composante adrenergique. • Enfin, une derniere approche a ete la recherche d'activite sur des recepteurs intra-pulmonaires comme les corps neuro-epitheliaux, structure intermediaire entre gaz alveolaires et sang capillaire. Au total, bien que ces donnees soient encore incompletes, elles permettent de progresser dans la connaissance du mecanisme d'action du bismesilate d'almitrine.
Colinked descriptors: improving vocabulary selection for end-user searching

This article introduces a new concept and technique for information retrieval called colinked descriptors. Borrowed from an analogous idea in bibliometrics—cocited references—colinked descriptors provide a theory and method for identifying search terms that, by hypothesis, will be superior to those entered initially by a searcher. The theory suggests a means of moving automatically from two or more initial search terms, to other terms that should be superior in retrieval performance to the two original terms. A research project designed to test this colinked descriptor hypothesis is reported. The results suggest that the approach is effective, although methodological problems in testing the idea are reported. Algorithms to generate colinked descriptors can be incorporated easily into system interfaces, front-end or pre-search systems, or help software, in any database that employs a thesaurus. The potential use of colinked descriptors is a strong argument for building richer and more complex thesauri that reflect as many legitimate links among descriptors as possible. © 1996 John Wiley & Sons, Inc.
Culture medium effects on vascular smooth muscle cell contractile protein expression and morphology in 2D v. 3D

Vascular tissue engineering is dependent on achieving both tissue strength and contractility. Proliferative, synthetic smooth muscle cells (SMCs) are necessary for producing strong, engineered vascular tissue; however, in vivo, healthy SMCs are quiescent and contractile. In this study, we evaluated the effects of culturing cells in a high serum, growth medium (GM), compared to a low serum, quiescence medium (QM). QM increases contractile protein expression and decreases proliferation in 2D primary human SMC cultures. We observed an increase in population doubling time within 5 days (from 23±1 to 47±3 hrs; n=6) in 2D human SMC cultures, consistent with a contractile phenotype. After 3 days in QM, smooth muscle α-actin (SMaA) increased 10-fold with similar increases in calponin (compared to SMCs cultured in GM). The cellular response was different when applied to 3D cultures, which were created by human SMC self-assembly into ring-shaped tissue constructs. SMC rings were cultured for 24 hours in GM followed by 13 days in GM or QM. The rings grown in QM were significantly thinner than rings grown in GM (400±30 v 540±90μm; n=5,4) with a visible increase in collagen deposition by picrosirius red staining. There was no detectable difference in SMaA or calponin expression within SMC ring samples cultured in GM or QM. This difference in SMC response indicates the need for other approaches to SMC differentiation in 3D constructs.
Improved determination of the bisphosphonate alendronate in human plasma and urine by automated precolumn derivatization and high-performance liquid chromatography with fluorescence and electrochemical detection.

Abstract An improved method for the determination of 4-amino-1-hydroxybutane-1,1-bisphosphonic acid (alendronate) in human urine and an assay in human plasma are described. The methods are based on co-precipitation of the bisphosphonate with calcium phosphates, automated pre-column derivatization of the primary amino group of the bisphosphonic acid with 2,3-naphthalene dicarboxyaldehyde (NDA)—N-acetyl- d -penicillamine (NAP) or cyanide (CN−) reagents, and high-performance liquid chromatography (HPLC) with electrochemical (ED) or fluorescence detection (FD). The feasibility of ED of the NDA—CN− derivative of alendronate has been demonstrated, and a HPLC—ED assay in human urine has been validated in the concentration range 2.5–50.0 ng/ml. In order to eliminate the cyanide ion from the assay procedure, several other nucleophiles in the NDA derivatization reaction were evaluated. An NDA—NAP reagent was found to produce highly fluorescent derivatives of alendronate. The assay in urine based on NDA—NAP derivatization and HPLC—FD has been developed and fully validated in the concentration range 1–25 ng/ml. Based on the same NDA—NAP derivatization, an assay in human plasma with a limit of quantification of 5 ng/ml has also been developed. Both HPLC—FD assays were utilized to support various human pharmacokinetic studies with alendronate.
Self-healing thermoplastic elastomer brush copolymers having a glassy polymethylmethacrylate backbone and rubbery polyacrylate-amide brushes

Abstract We synthesized a series of brush copolymers having glassy polymethylmethacrylate (PMMA) backbone and flexible polyacrylate-amide (PA-amide) brushes that exhibit thermoplastic elastomer properties. Importantly, the dynamic hydrogen bonds in the soft PA-amide matrix enables the material to self-heal after mechanical damage at room temperature without the need of any external stimulus.
Nearly precise excision: a new type of DNA alteration associated with the translocatable element Tn10

Abstract We describe an unusual DNA alteration, "nearly precise excision," which has been identified among tetracycline-sensitive deletion derivatives of lambda phages carrying the translocatable tetracycline-resistance element Tn10. DNA sequence analysis of two such derivatives demonstrates that each retains exactly 50 bp of Tn10 material. The original junctions between lambda and Tn10 sequences remain intact; however, an internal deletion has occurred within Tn10 which eliminates all but the last few base pairs at each end of the element. This deletion occurs within a short A + Trich inverted repeat which is present near each end of Tn10. Nearly precise excisions occur at frequencies comparable to Tn10-promoted deletions, inversions and translocations, and, like these other events, are independent of phage and bacterial functions for homologous recombination ( rec A, rec B, red ). It is not yet clear, however, whether nearly precise excisions are specifically promoted by Tn10 or whether they arise during the course of normal DNA replication processes as a consequence of unusual symmetries present in the DNA sequence at the ends of Tn10.
Surface properties of a network model of electrons in solids

Abstract Surface properties of a network model of electrons in solids are discussed. In the model, electrons are restricted to move along lines connecting node points of a periodic network. Each node point on the network corresponds to an atom. A potential well is introduced for each atom or node point so that as the depth of the potential becomes large, one has the tight binding model and, as the potential vanishes and the number of node points increases, one has the Sommerfeld free electron model. Exact wave functions and energy levels have been obtained elsewhere for the model when periodic boundary conditions are applied. When free boundaries are introduced, a band of surface states develops. Its depth of penetration into the crystal as a function of wave number is investigated. The edges of the surface energy bands are located and their density of states is calculated.
Insulin, but not contraction, activates Akt/PKB in isolated rat skeletal muscle.

Insulin and muscle contraction potently stimulate glucose uptake in mammalian skeletal muscle. Studies in muscle and adipose tissue have shown that insulin induces its receptor-dependent phosphorylation of insulin receptor substrates 1 and 2, which leads to activation of polyphosphatidylinositol (PI) 3′-kinase. In contrast, muscle contraction stimulates glucose transport via a mechanism that is independent of insulin, but the two pathways may converge downstream at the level of stimulation of GLUT4 translocation. In the present study, we have examined the role of Akt, an insulin-activated serine threonine kinase that has previously been shown to increase glucose transport in adipocytes. Either insulin or in vitro muscle contraction significantly elevated glucose transport in isolated rat epitrochlearis and soleus muscles. However, Akt kinase activity was significantly stimulated by insulin and not contraction. Moreover, wortmannin, an inhibitor of PI 3′-kinase, completely blocked the insulin-stimulated increase in Akt activity and glucose transport but did not alter either of these parameters in contracting muscles. The increases in Akt activity were paralleled by a decrease in the electrophoretic mobility of Akt, indicative of phosphorylation of Akt by an upstream kinase. These changes in Akt mobility appeared to be at least partially because of phosphorylation of Akt on serine 473. A putative downstream target of Akt, p70 S6 kinase, showed similar changes in mobility in response to insulin but not contraction. These data support the view that Akt is a downstream target of PI 3′-kinase and is involved in the signaling pathways involved in insulin but not contraction stimulation of glucose transport in skeletal muscle. These data provide further evidence that two distinct pathways exist for the stimulation of glucose transport in mammalian skeletal muscle.
How Does Labrador Sea Water Enter the Deep Western Boundary Current

Abstract Labrador Sea Water (LSW), a dense water mass formed by convection in the subpolar North Atlantic, is an important constituent of the meridional overturning circulation. Understanding how the water mass enters the deep western boundary current (DWBC), one of the primary pathways by which it exits the subpolar gyre, can shed light on the continuity between climate conditions in the formation region and their downstream signal. Using the trajectories of (profiling) autonomous Lagrangian circulation explorer [(P)ALACE] floats, operating between 1996 and 2002, three processes are evaluated for their role in the entry of Labrador Sea Water in the DWBC: 1) LSW is formed directly in the DWBC, 2) eddies flux LSW laterally from the interior Labrador Sea to the DWBC, and 3) a horizontally divergent mean flow advects LSW from the interior to the DWBC. A comparison of the heat flux associated with each of these three mechanisms suggests that all three contribute to the transformation of the boundary current a...
Determination of pressure solution shortening in sandstones

Abstract A new method for the determination of pressure solution shortening in sandstones uses the geometry of grain-to-grain interpenetrations and grains truncated against solution surfaces. These features are used to construct plots from which the magnitude and direction of the pressure solution shortening can be determined. Using simulated pressure solution deformation of artificial and natural grain populations, the new method is shown to correctly assess a variety of coaxial and non-coaxial shortenings. Although primarily intended to determine shortening, the method can also quantify extension related to growth of beards or overgrowths during pressure solution. Application of the method to naturally deformed quartz arenite samples shows that pressure solution shortening of up to 26% occurred during compaction and 22% during layer-parallel shortening.
Intracutaneous vaccination of rabbits with the E6 gene of cottontail rabbit papillomavirus provides partial protection against virus challenge.

Abstract DNA vaccination of rabbit skin with the L1 gene of cottontail rabbit papillomavirus (CRPV) has previously been shown to induce prophylactic immunity against CRPV. We now describe the effects of vaccination with the CRPV E6 gene, using the same approach. The experimental vaccine pdCMV-E6 encoded both the truncated and full length forms of CRPV E6 protein. The control vaccine pCMV-β encoded β galactosidase. Rabbits were vaccinated with DNA-coated gold particles, using a gene gun. Each rabbit received an initial vaccination with 30 μg DNA and 3 weeks later a booster vaccination, also with 30 μg DNA. pdCMV-E6-vaccinated rabbits developed E6-specific cellular immunity as determined by proliferation assays using peripheral blood mononuclear cells from animals prior to challenge, but did not develop detectable humoral immunity to E6 proteins, as evaluated by ELISA using two different E6 antigen preparations. Control rabbits developed humoral immunity to β galactosidase. All rabbits were challenged by infection of nine skin sites with live CRPV virus and monitored for papilloma formation. None of four control rabbits was protected at any of the challenge sites. Of six rabbits vaccinated with pdCMV-E6, two were completely protected and one was virtually completely protected (tiny papillomas at just two of nine challenge sites). These three rabbits also exhibited significant E6-specific in vitro proliferative responses. The four E6 DNA-vaccinated rabbits that were not completely protected exhibited evidence of partial protection: some challenge sites did not form papillomas; papilloma onset was delayed; papilloma burden was less. These results demonstrate that partial prophylaxis against papillomavirus-induced disease can be achieved by intracutaneous vaccination with a recombinant plasmid encoding the papillomavirus E6 protein.
Are one-day admissions for carotid endarterectomy feasible?

Abstract Background: In 1990, a clinical pathway for streamlining the care of patients undergoing elective carotid endarterectomy was developed and tested at our institution. This consisted of extensive preoperative patient education in the surgeon's office, outpatient arteriography (now performed only on select patients), same-day admission, regional anesthesia when possible, selective use of the intensive care unit (ICU), and early discharge on the first postoperative day when feasible. Patients and methods: Between January 1, 1991 and June 30, 1994, 186 patients were entered into the protocol. Twenty-six percent of the patients were asymptomatic, while 74% had either transient symptoms or a prior stroke; 13% were operated on under general anesthesia. Results: Three (1.6%) patients developed neurologic complications: 1 minor stroke, 1 transient ischemic attack, and 1 intracerebral hematoma; and 18 (10%) patients required the ICU postoperatively. On the first postoperative day, 157 patients were discharged. Average operative time was 48 minutes (range 39 to 61). Average length of stay (LOS) was 1.27 days. One death occurred on the 28th postoperative day from cardiac causes, and there were no hospital readmissions. Cost savings were over $3,000/patient when compared to the diagnosis-related group reimbursement. Because of the distribution of the data, statistical analysis was not feasible; however, several trends were clear. Neurologic complications, admission to the ICU, and increasing LOS all diminished the cost efficiency of carotid endarterectomy. Type of anesthesia and the use of a shunt or patching did not affect cost. Clearly, increasing the length of operation would also decrease cost efficiency. Conclusions: Adoption of the clinical pathway presented here is feasible in any institution. One-day admission for patients undergoing carotid endarterectomy has been shown to be safe, highly cost-effective, and results in more efficient use of scarce resources, such as the ICU.
A prospective evaluation of the repeatability of left ventricular ejection fraction measurement by gated SPECT

Gated single-photon emission computed tomography (SPECT) is widely used for myocardial perfusion imaging and provides an automated assessment of left ventricular ejection fraction (LVEF). We prospectively tested the repeatability of serial SPECT-derived LVEF. This information is essential in order to inform the interpretation of a change in LV function on serial testing. Consenting patients (n = 50) from among those referred for clinically indicated gated myocardial perfusion SPECT (MPs) were recruited. Following the clinical rest-stress study, patients were repositioned on the camera table for a second acquisition using identical parameters. Patient positioning, image acquisition and processing for the second scan were independently performed by a technologist blinded to the clinical scan. Quantitative LVEF was generated by Quantitative Gated SPECT and recorded as EF1 and EF2, respectively. Repeatability of serial results was assessed using the Bland-Altman method. The limits of repeatability and repeatability coefficients were generated to determine the maximum variation in LVEF that can be expected to result from test variability. Repeatability was tested across a broad range of LV systolic function and myocardial perfusion. The mean difference between EF1 and EF2 was 1.6% (EF units), with 95% limits of repeatability of +9.1% to −6.0% (repeatability coefficient 7.5%). Correlation between serial EF measurements was excellent (r = 0.9809). Similar results were obtained in subgroups based on normal or abnormal EF and myocardial perfusion. The largest repeatability coefficient of 8.1% was seen in patients with abnormal LV systolic function. When test protocol and acquisition parameters are kept constant, a difference of >8% EF units on serial MPs is indicative of a true change 95% of the time.