bluuebunny/crossref_metadata_2025 huggingface dataset:
Protein resistant surfaces: Comparison of acrylate graft polymers bearing oligo-ethylene oxide and phosphorylcholine side chains
Authors: Feng Wei , Zhu Shiping , Ishihara Kazuhiko , Brash John L.
Published: September 2006

The objective of this work was to compare poly(ethylene glycol) (PEG) and phosphorylcholine (PC) moieties as surface modifiers with respect to their ability to inhibit protein adsorption. Surfaces were prepared by graft polymerization of the methacrylate monomers oligo(ethylene glycol) methyl ether methacrylate (OEGMA, MW 300, PEG side chains of length n=4.5) and 2-methacryloyloxyethyl phosphorylcholine (MPC, MW295). The grafted polymers thus contained short PEG chains and PC, respectively, as side groups. Grafting on silicon was carried out using surface-initiated atom transfer radical polymerization (ATRP). Graft density was controlled via the surface density of the ATRP initiator, and chain length of the grafts was controlled via the ratio of monomer to sacrificial initiator. The grafted surfaces were characterized by water contact angle, x-ray photoelectron spectroscopy, and atomic force microscopy. The effect of graft density and chain length on fibrinogen adsorption from buffer was investigated using radio labeling methods. Adsorption to both MPC- and OEGMA-grafted surfaces was found to decrease with increasing graft density and chain length. Adsorption on the MPC and OEGMA surfaces for a given chain length and density was essentially the same. Very low adsorption levels of the order of 7 ng/cm2 were seen on the most resistant surfaces. The effect of protein size on resistance to adsorption was studied using binary solutions of lysozyme (MW 14 600) and fibrinogen (MW 340 000). Adsorption levels in these experiments were also greatly reduced on the grafted surfaces compared to the control surfaces. It was concluded that at the lowest graft density, both proteins had unrestricted access to the substrate, and the relative affinities of the proteins for the substrate (higher affinity of fibrinogen) determined the composition of the layer. At the highest graft density also, where the adsorption of both proteins was very low, no preference for one or the other protein was evident, suggesting that adsorption did not involve penetration of the grafts and was occurring at the outer surface of the graft layer. It thus seems likely that preference among different proteins based on ability to penetrate the graft layer would occur, if at all, at a grafting density intermediate between 0.1 and 0.39 /cm2. Again the MPC and OEGMA surfaces behaved similarly. It is suggested that the main determinant of the protein resistance of these surfaces is the “water barrier layer” resulting from their hydrophilic character. In turn the efficacy of the water barrier depends on the monomer density in the graft layer.
Monitoring kinetics of surface initiated atom transfer radical polymerization by quartz crystal microbalance with dissipation
Authors: Ma Hongwei , Textor Marcus , Clark Robert L. , Chilkoti Ashutosh
Published: September 2006

This article reports that the kinetics of surface-initiated atom transfer radical polymerization can be quantified by the quartz crystal microbalance with dissipation (QCM-D) technique. The kinetics of in situ growth of poly(oligoethylene glycol methylmethacrylate) monitored on a gold-coated QCM-D sensor chip revealed that changes in the experimentally observed frequency (ΔF) and dissipation (ΔD) as a function of polymerization time were a function of the initiator density, and that the experimental response could be predicted from a continuum model.
Quest for the magnetic monopole
Authors: Carrigan Richard A.
Published: September 2006

A brief review is given of the properties of the magnetic monopole and of the experimental efforts to detect the postulated particle. (AIP)
MHD power generation
Authors: Kantrowitz Arthur , Rosa Richard J.
Published: September 2006

A brief review is given of the status of the MHD generator. Topics discussed include basic principles of operation, efficiency, applications, and pollution considerations. (AIP)
Advances in solar heating and cooling systems
Authors: Ward Dan S.
Published: September 2006

A brief review is given of a number of proposed methods of collecting, storing, and utilizing solar energy. (AIP)
QED is a success with PS
Authors: Manka C. K. , Mittelstaedt Karen J.
Published: September 2006

The emission spectra of positronium is calculated in the Bohr model.(AIP)
Cosmologies with varying gravity
Authors: Mansfield V. N.
Published: September 2006

Recent calculations using group theory predict an increase in the gravitational interaction in cosmic time.(AIP)
Prospects for solar electricity
Authors: Pollard William G.
Published: September 2006

Simple calculations are performed on the cost and the efficiency of the production of electricity from solar radiation using the solar-thermal method and the photovoltaic method.(AIP)
Street light holography
Authors: Turtle R. R.
Published: September 2006

The production of a hologram is demonstrated using only a camera, aluminum foil, and a mercury vapor street light.
A solar house for northern latitudes
Authors: Stinner Arthur O.
Published: September 2006

Using meteorlogical data for southern Ontario, simple calculations are performed on the theoretical feasibility of solar houses. The required storage tank is discussed in detail. (AIP)
Energy storage by electrochemical reduction of carbon dioxide
Authors: Williams Richard
Published: September 2006

Photovoltaic generators can be an important energy alternative but must be coupled to energy storage systems to effectively match supply with demand. This paper explores electrochemical reduction of carbon dioxide for energy storage and use, including sources of carbon dioxide and electrochemical reduction to formic acid (HCOOH). The idea that HCOOH (the simplest product of electrochemical CO2 reduction) can be catalytically decomposed to generate hydrogen (a possible future material gas replacement) is also introduced. (AIP)
Energy and the automobile
Authors: Waring Gene
Published: September 2006

A detailed analysis of the factors leading to the poor energy efficiency of automobiles is given. Both thermal and mechanical efficiencies are taken into account.(AIP)
Power plant induced rainfall modification: Fact or fiction?
Authors: Patrinos A. A.
Published: September 2006

The METER Program of the Department of Energy is discussed. It is concluded that there is at present no evidence of power plant effects on rainfall.(AIP)
Unraveling the mysteries of the atom
Authors: Lederman Leon
Published: September 2006

A brief discusion is given of the role of the Fermilab accelerator in verifying the quark model of elementary particles. (AIP)
Recent use of the Thomson parabola ion analyzer
Authors: Anthes John P.
Published: September 2006

The ablation depth of a laser target is measured as a function of laser intensity. (AIP)
A chlorophyll solar cell
Authors: Ludlow J. Christopher
Published: September 2006

A simple chlorophyll solar cell has been designed, built, and tested. A voltage output versus time curve has also been obtained. (AIP)
Superconducting microelectronics
Authors: Henry Richard W.
Published: September 2006

A simple explanation, via a pendulum analogy, is given for the Josephson effect. Uses of Josephson junctions and SQUIDs are discussed.(AIP)
The fine-beam cathode-ray tube and the observant and enquiring student Part 2
Authors: Webb John le P.
Published: September 2006

For a description of the experimental apparatus, see Part 1 on page 80 of the February issue.
Home energy use
Authors: Child V. Gene
Published: September 2006

A cost analysis is performed in the use of electricitiy and natural gas in homes in the Denver, Colorado area. (AIP)
Spectrally selective surface coatings for energy efficiency and solar applications
Authors: Granqvist C. G.
Published: September 2006

The radiative properties of surfaces, emittance, transmittance, reflectance, and absorptance, are considered as they relate to photothermal conversion of solar radiation. (AIP)
Probing the structure of the universe from quarks to cosmology
Authors: Kolb Edward W. , Quigg Chris
Published: September 2006

The study of fundamental physical systems in the laboratory has implications for the evolution of our Universe as a whole. The next step toward an ultimate understanding of the Universe requires a powerful new instrument for the study of the physics of elementary particles: the Supercoducting Supercollider.
Liberal Education from a Physics Project
Authors: Richards Sumner F. , Smart Peter
Published: September 2006

When high school students from Lexington, Massachusetts organized their own solar eclipse expedition they absorbed lessons from interaction with industry, shared experience with Girl Guides, coverage by the press, and an encounter with nature.
Brief Chronologies which Illustrate the Historical Development of Measurement Techniques, Apparatus, and Standards Part IV: measurement of time
Authors: Bender Paul A.
Published: September 2006

Three earlier articles in this series gave the chronologies of the development of standards of length and length-measuring devices, the development of computing machines and the mathematics associated with computers, and the measurement of mass and weight.
Communication, Value Systems and Algorithms for sin A
Authors: Chapman Seville
Published: September 2006

Communication is often thought to be a language problem. In reality it is not so much words, as commonality of background and value systems, that make communication possible.
Satellite Orbits
Authors: Iona Mario
Published: September 2006

The various types of satellite and projectile orbits are described and related to the conditions, in terms of energy and angular momentum, under which the ideal orbits occur. The transient nature of the initial and final part of a satellite's path and the conditions necessary for placing a satellite in a given orbit are discussed.
The Discovery of Electron Diffraction by Davisson and Germer
Authors: Calbick C. J.
Published: September 2006

The Davisson-Germer experiments in low-voltage electron diffraction established the wave nature of the electron and confirmed the de Broglie theory upon which wave mechanics is based. For this discovery, Davisson, jointly with G. P. Thomson who at the same time discovered electron diffraction using much higher-voltage electrons, was awarded the Nobel Prize.

The discovery that an index of refraction that varied in voltage must be assigned to the bombarding electrons confirmed the Fermi theory of electrons in metals. The anomalies observed in the index led to the initial development of the dynamical theory of electron diffraction.

The occurrence of diffraction beams due to ordered adsorption of gas atoms on the crystal surface is now leading to a new understanding of the physics of surfaces.
Education of a Danish Physicist
Authors: Cook C. Sharp
Published: September 2006

A survey of the Danish educational system is presented, with special emphasis on the education of a physicist. It is based on the observations by the author during the year he spent in Denmark.
High Centrifugal Fields
Authors: Beams J. W.
Published: September 2006

By use of appropriately designed centrifuges, it is possible to produce acceleration a billion times that of a falling body. The design of such apparatus and its use in a variety of types of research are described. Such centrifuges can be used for molecular sedimentations and separation. From measurements on these processes, molecular weights can be determined. By magnetic suspension, friction has been reduced so that a rotor may "coast" without drive for years with the loss of one revolution per second per day when the initial speed is 800 revolutions per second.
An Introvert Rocket or Mechanical Jumping Bean
Authors: Sutton Richard M.
Published: September 2006

A simple mechanical rocket which "lifts itself by its own bootstraps" two or three times its own height is described. Energy and momentum considerations are discussed and its uses as a demonstration device or as a laboratory instrument are detailed.
Electromotive Force and The Law of Induction
Authors: Phillips Melba
Published: September 2006

The concept and definition of electromotive force are discussed. The distinction between conservative fields such as those produced by static charges and the fields produced by electromagnetic induction is stressed. Problems proposed in the September number of this journal are solved as illustrations.
The Oscilloscope and How It May Be Used
Authors: Christensen F. E.
Published: September 2006

The basic circuits of the cathode ray oscilloscope are described. The instrument is essentially a voltmeter whose sensitivity may be varied widely and one that responds to signals varying greatly in frequency and character, that is "wave form," whether repetitive or transient and of short duration. Actual circuits for use of the instrument in determining characteristics of coils, power supplies, vacuum tubes are described. The display of wave patterns, Lissajous figures and the measurement of phase change, and of frequency, are discussed.
The Sceptical Physicist
Authors: Tricker R. A. R.
Published: September 2006

Science teaching, both in school and university, is geared very closely to utilitarian aims. Has it also an important contribution to make a liberal education? This article argues that it has, but that its opportunities are not being seized. Various ways of improving on the present state of affairs are discussed.
Plasma Physics
Authors: Brown Sanborn C.
Published: September 2006

The fourth state of matter, the "plasma state," although relatively rarely found at the surface of the earth, is the most commonly found state of matter when the known universe is considered. The plasma state, consisting of a neutral collection of electrons and positive ions may have a very wide range of densities. The production and properties of this state are described. Plasmas are of particular interest now because of the possibility of initiating neuclear fusion in them but they also appear in phenomena ranging from those found in a neon sign, a lightning stroke, the ionosphere about the earth, shock waves, and the compressed layer of hot gas around an astronaut's capsule as the comes back through the earth's atmosphere.
Fracture of Solids
Authors: Field J. E.
Published: September 2006

The type of fraction produced by various forms of stress, the dependence on the nature of the stress, and the rate of application are described. The role of microscopic cracks and the departure of actual strength from theoretical values are discussed. Illustrations are given of the propagation of fracture.
The Key Ideas of Quantum Mechanics
Authors: Ford Kenneth W.
Published: September 2006

The following article is a modified and abbreviated version of Chapter 3 of the author's book, The World of Elementary Particles. Since the book is intended for the intelligent layman and for the beginning student of physics, the discussion and illustrations are simple. The intent of this article is not so much to instruct the reader of this journal as to indicate that deep and important ideas of modern physics can find a place in the elementary curriculum.
The Design and Use of a Light Probe for Teaching Science to Blind Students
Authors: Carver Thomas R.
Published: September 2006

The evolution, design and use of an optical probe particularly suited to general use in teaching laboratory science to blind students is described herein. Devices of this type have been frequently conceived, but have not been constructed, for versatility and convenience. Their potential use seems to be overlooked, mostly because they are not suitable devices with which to read. The experience in this particular case was in a physics laboratory not otherwise prepared or equipped for blind students, and the experience showed that a simple pocket-sized light probe with certain necessary features proved to be the missing link to enable ordinary experiments to be done by the blind.
The Arrow of Time
Authors: Ford Kenneth W.
Published: September 2006

This article is taken from an introductory textbook by the author, scheduled for publication early in 1968; it represents the concluding section of a chapter on entropy and the second law of thermodynamics. It attempts to draw together the microscopic and macroscopic threads of physics as applied to the concept of time.
Achievement Testing Program of Project Physics
Authors: Winter Stephen S. , Welch Wayne W.
Published: September 2006

The major concern of the successive groups responsible for developing the Unit Tests for Project Physics has been to make the tests representative of both the content and the style of the course. And as the course has developed through successive editions with slightly changed emphasis, so have the approaches taken by the test groups. This paper outlines the basic guidelines for the development of the Project Physics Unit Tests. It tells of past and current activities of the test groups, and, to the extent possible at this time, describes the kinds of Unit Tests that will become available to teachers of Project Physics. (Members of the Project who have served as the test development group include Stephen Brush, William Shurcliff, F. James Rutherford, Andrew Ahlgren, Ashok Khosla, David Clarke, Dean Casperson, Jay Hauben, Banesh Hoffmann, and the authors.)
The Reference Circle in Introductory Physics
Authors: Clark Clifton Bob
Published: September 2006

The knowledge of the kinematics of uniform circular motion is the basis for a method of solving (without the use of calculus) the problem of finding the time rate of change of a quantity which is a known sinusoidal function of time. The inverse problem of finding the quantity which has a known sinusoidal time rate of change, can be solved by the same method. As an example of the use of the method, the expression is derived for the steady state current, as a function of time, in a simple series alternating current circuit.
Muscle-specific creatine kinase gene polymorphism and running economy responses to an 18-week 5000-m training programme
Authors: Zhou D Q , Hu Y , Liu G , Gong L , Xi Y , Wen L
Published: September 2006

Objective:To investigate the association between muscle-specific creatine kinase (CKMM) gene polymorphism and the effects of endurance training on running economy.

Methods:102 biologically unrelated male volunteers from northern China performed a 5000-m running programme, with an intensity of 95–105% ventilatory threshold. The protocol was undertaken three times per week and lasted for 18 weeks. Running economy indexes were determined by making the participants run on a treadmill before and after the protocol, and the A/G polymorphism in the 3′ untranslated region of CKMM was detected by polymerase chain reaction-restricted fragment length polymorphism (NcoI restriction enzyme).

Results:Three expected genotypes for CKMM-NcoI (AA, AG and GG) were observed in the participants. After training, all running economy indexes declined markedly. Change in steady-state consumption of oxygen, change in steady-state consumption of oxygen by mean body weight, change in steady-state consumption of oxygen by mean lean body weight and change in ventilatory volume in AG groups were larger than those in AA and GG groups.

Conclusions:The findings indicate that the CKMM gene polymorphism may contribute to individual running economy responses to endurance training.
Influences of palatal side design and finishing on the wearability and retention of mouthguards
Authors: Maeda Y , Machi H , Tsugawa T
Published: September 2006

Objectives:To examine the influences of design and finishing on mouthguard wearability and retention.

Materials and methods:17 students at the Dental Technician Institute at Osaka University School of Dentistry, Osaka, Japan, participated in this study after providing informed consent. For each student, a single-layer custom-made mouthguard was fabricated from a 3.8-mm-thick ethylene-vinyl acetate sheet using a standardised procedure to obtain a precise fit. Each mouthguard was modified by changing the margin location and shape through five consecutive steps. At each step, questionnaires with a visual analogue scale regarding wearability (comfort, breathing, speaking, swallowing, lip closure, temporomandibular joint fatigue and swallowing) and retention were completed by subjects after wearing the mouthguard for 5 min. Statistical analyses were carried out among the steps using Wilcoxon’s signed-rank test with a significance level of p<0.05.

Results:Significant improvements were found for comfort, breathing, speaking and swallowing by trimming the palatal margin to the cervical area, smooth finishing and occlusal adjustment of the mouthguard (p<0.01). No significant differences were found for retention throughout the procedure.

Conclusions:Within the limitations of this experimental study, design and finishing at the palatal side appear to have significant influences on mouthguard wearability, but not retention.
A GENERAL FRAMEWORK FOR BICLUSTERING GENE EXPRESSION DATA
Authors: LI HAIFENG , CHEN XIN , ZHANG KESHU , JIANG TAO
Published: September 2006

A large number of biclustering methods have been proposed to detect patterns in gene expression data. All these methods try to find some type of biclusters but no one can discover all the types of patterns in the data. Furthermore, researchers have to design new algorithms in order to find new types of biclusters/patterns that interest biologists. In this paper, we propose a novel approach for biclustering that, in general, can be used to discover all computable patterns in gene expression data. The method is based on the theory of Kolmogorov complexity. More precisely, we use Kolmogorov complexity to measure the randomness of submatrices as the merit of biclusters because randomness naturally consists in a lack of regularity, which is a common property of all types of patterns. On the basis of algorithmic probability measure, we develop a Markov Chain Monte Carlo algorithm to search for biclusters. Our method can also be easily extended to solve the problems of conventional clustering and checkerboard type biclustering. The preliminary experiments on simulated as well as real data show that our approach is very versatile and promising.
RECONSTRUCTING AN ULTRAMETRIC GALLED PHYLOGENETIC NETWORK FROM A DISTANCE MATRIX
Authors: CHAN HO-LEUNG , JANSSON JESPER , LAM TAK-WAH , YIU SIU-MING
Published: September 2006

Given a distance matrix M that specifies the pairwise evolutionary distances between n species, the phylogenetic tree reconstruction problem asks for an edge-weighted phylogenetic tree that satisfies M, if one exists. We study some extensions of this problem to rooted phylogenetic networks. Our main result is an O(n2 log n)-time algorithm for determining whether there is an ultrametric galled network that satisfies M, and if so, constructing one. In fact, if such an ultrametric galled network exists, our algorithm is guaranteed to construct one containing the minimum possible number of nodes with more than one parent (hybrid nodes). We also prove that finding a largest possible submatrix M′ of M such that there exists an ultrametric galled network that satisfies M′ is NP-hard. Furthermore, we show that given an incomplete distance matrix (i.e. where some matrix entries are missing), it is also NP-hard to determine whether there exists an ultrametric galled network which satisfies it.
Cancer Stem Cells: Models and Concepts
Authors: Dalerba Piero , Cho Robert W. , Clarke Michael F.
Published: September 2006

Although monoclonal in origin, most tumors appear to contain a heterogeneous population of cancer cells. This observation is traditionally explained by postulating variations in tumor microenvironment and coexistence of multiple genetic subclones, created by progressive and divergent accumulation of independent somatic mutations. An additional explanation, however, envisages human tumors not as mere monoclonal expansions of transformed cells, but rather as complex tridimensional tissues where cancer cells become functionally heterogeneous as a result of differentiation. According to this second scenario, tumors act as caricatures of their corresponding normal tissues and are sustained in their growth by a pathological counterpart of normal adult stem cells, cancer stem cells. This model, first developed in human myeloid leukemias, is today being extended to solid tumors, such as breast and brain cancer. We review the biological basis and the therapeutic implications of the stem cell model of cancer.
Thiazolidinediones enhance skeletal muscle triacylglycerol synthesis while protecting against fatty acid-induced inflammation and insulin resistance
Authors: Todd Mark K. , Watt Matthew J. , Le Jamie , Hevener Andrea L. , Turcotte Lorraine P.
Published: September 2006

In the present investigation, we studied the effects of thiazolidinedione (TZD) treatment on insulin-stimulated fatty acid (FA) and glucose kinetics in perfused muscle from high-fat (HF)-fed rats. We tested the hypothesis that TZDs prevent FA-induced insulin resistance by attenuating proinflammatory signaling independently of myocellular lipid levels. Male Wistar rats were assigned to one of three 3-wk dietary groups: control chow fed (CON), 65% HF diet (HFD), or TZD- (troglitazone or rosiglitazone) enriched HF diet (TZD + HFD). TZD treatment led to a significant increase in plasma membrane content of CD36 protein in muscle (red: P = 0.01, and white: P = 0.001) that correlated with increased FA uptake (45%, P = 0.002) and triacylglycerol (TG) synthesis (46%, P = 0.03) during the perfusion. Importantly, whereas HF feeding caused increased basal TG ( P = 0.047), diacylglycerol ( P = 0.002), and ceramide ( P = 0.01) levels, TZD treatment only prevented the increase in muscle ceramide. In contrast, all of the muscle inflammatory markers altered by HF feeding (↑NIK protein content, P = 0.009; ↑IKKβ activity, P = 0.006; ↓IκB-α protein, P = 0.03; and ↑JNK phosphorylation, P = 0.003) were completely normalized by TZD treatment. Consistent with this, HFD-induced decrements in insulin action were also prevented by TZD treatment. Thus our findings support the notion that TZD treatment causes increased FA uptake and TG accumulation in skeletal muscle under insulin-stimulated conditions. Despite this, TZDs suppress the inflammatory response to dietary lipid overload, and it is this mechanism that correlates strongly with insulin sensitivity.
Lipid-induced β-cell dysfunction in vivo in models of progressive β-cell failure
Authors: Goh Tracy T. , Mason Timothy M. , Gupta Neehar , So Abby , Lam Tony K. T. , Lam Loretta , Lewis Gary F. , Mari Andrea , Giacca Adria
Published: September 2006

We determined the effect of 48-h elevation of plasma free fatty acids (FFA) on insulin secretion during hyperglycemic clamps in control female Wistar rats ( group a) and in the following female rat models of progressive β-cell dysfunction: lean Zucker diabetic fatty (ZDF) rats, both wild-type ( group b) and heterozygous for the fa mutation in the leptin receptor gene ( group c); obese (fa/fa) Zucker rats (nonprediabetic; group d); obese prediabetic (fa/fa) ZDF rats ( group e); and obese (fa/fa) diabetic ZDF rats ( group f). FFA induced insulin resistance in all groups but increased C-peptide levels (index of absolute insulin secretion) only in obese prediabetic ZDF rats. Insulin secretion corrected for insulin sensitivity using a hyperbolic or power relationship (disposition index or compensation index, respectively, both indexes of β-cell function) was decreased by FFA. The decrease was greater in normoglycemic heterozygous lean ZDF rats than in Wistar controls. In obese “prediabetic” ZDF rats with mild hyperglycemia, the FFA-induced decrease in β-cell function was no greater than that in obese Zucker rats. However, in overtly diabetic obese ZDF rats, FFA further impaired β-cell function. In conclusion, 1) the FFA-induced impairment in β-cell function is accentuated in the presence of a single copy of a mutated leptin receptor gene, independent of hyperglycemia. 2) In prediabetic ZDF rats with mild hyperglycemia, lipotoxicity is not accentuated, as the β-cell mounts a partial compensatory response for FFA-induced insulin resistance. 3) This compensation is lost in diabetic rats with more marked hyperglycemia and loss of glucose sensing.
Medroxyprogesterone Acetate But Not Drospirenone Ablates the Protective Function of 17β-Estradiol in Aldosterone Salt-Treated Rats
Authors: Arias-Loza Paula Anahi , Hu Kai , Schäfer Andreas , Bauersachs Johann , Quaschning Thomas , Galle Jan , Jazbutyte Virginija , Neyses Ludwig , Ertl Georg , Fritzemeier Karl-Heinrich , Hegele-Hartung Christa , Pelzer Theo
Published: September 2006

Controversial results obtained from human and animal studies on the prevention of heart disease by estrogens and progestins warrant a better understanding of nuclear hormone receptor function and interaction. To address this issue and taking into account that effects of synthetic progestins are not only referable to action through the progesterone receptor but may also be mediated by other steroid receptors, we characterized cardiovascular function and inflammatory gene expression in aldosterone salt-treated rats on long-term administration of 17β-estradiol, medroxyprogesterone acetate, and drospirenone, a new progestogen exhibiting antimineralocorticoid activity. The complex pattern of cardiovascular injury in ovariectomized Wistar rats induced by chronic aldosterone infusion plus a high-salt diet was significantly attenuated in sham-ovariectomized rats and by coadministration of 17β-estradiol in ovariectomized animals after 8 weeks of continuous treatment. The beneficial role of 17β-estradiol on blood pressure, cardiac hypertrophy, vascular osteopontin expression, perivascular fibrosis, and impaired NO-dependent relaxation of isolated aortic rings was completely abrogated by coadministration of medroxyprogesterone acetate. In contrast, drospirenone was either neutral or additive to 17β-estradiol in protecting against aldosterone salt-induced cardiovascular injury and inflammation. The current results support the hypothesis of complex interactions among estrogen, progesterone, glucocorticoid, androgen, and mineralocorticoid receptor signaling in cardiovascular injury and inflammation. Novel progestins, such as drospirenone, confer superior effects compared with medroxyprogesterone acetate in a model of aldosterone-induced heart disease because of its antimineralocorticoid properties.
Genome-Wide Scan for Premature Hypertension Supports Linkage to Chromosome 2 in a Large Kyrgyz Family
Authors: Kalmyrzaev Bolot , Aldashev Almaz , Khalmatov Mitalib , Polupanov Andrey , Jumagulova Ainagul , Mamanova Lira , Wilkins Martin R. , Town Margaret
Published: September 2006

We report a genome-wide scan for susceptibility loci to hypertension in a single Kyrgyz family where 10 of the affected relatives developed hypertension before the age of 35 years, and some members have suffered stroke. The early onset of disease and the geographic isolation of the Kyrgyz population are both expected to select for an increased influence of genetic factors in hypertension. We genotyped 44 individuals from this Krygyz family with 374 microsatellite markers, covering a 10-centimorgan map. Nonparametric analysis suggests that affected status is linked to loci in the chromosome 2q23 to q37 genomic interval, whereas 2-point parametric analysis returned a logarithm of odds score of 2.67 for marker D2S2330 (2q24.3). Multipoint linkage analysis substantiated the evidence for a hypertension susceptibility allele in the chromosome 2q23 to q36 region. Fine mapping and haplotype analysis implicate that the genetic lesion resides between markers D2S2380 (166.5 cM) and D2S335 (175.9 cM). This finding supports other recent studies of early onset hypertension suggesting that the region 2q24.3 to q31.1 encompasses a novel locus for premature hypertension.
Circulating Activities of Angiotensin-Converting Enzyme, Its Homolog, Angiotensin-Converting Enzyme 2, and Neprilysin in a Family Study
Authors: Rice Gillian I. , Jones Amy L. , Grant Peter J. , Carter Angela M. , Turner Anthony J. , Hooper Nigel M.
Published: September 2006

The renin–angiotensin system is a key regulator of blood pressure (BP), with inhibitors of angiotensin-converting enzyme (ACE) used clinically to treat hypertension and other cardiovascular conditions. ACE2 is a newly identified member of this system, which converts angiotensin II to angiotensin (1-7), and of which the occurrence in plasma has not been investigated. The aim of this study was to determine the heritability of circulating ACE, ACE2, and neprilysin (NEP), which may also be a regulator of BP, in a family study, and to determine covariates that contribute to the variation in plasma activity. ACE, ACE2, and NEP activities were measured in plasma from 534 subjects in the Leeds Family Study using selective fluorogenic substrates. Genetic factors accounted for 24.5%, 67%, and 22.7% of the phenotypic variation in circulating ACE, ACE2, and NEP, respectively. ACE insertion/deletion polymorphism and other measured covariates accounted for 23.8% of variance in circulating ACE. High-density lipoprotein cholesterol was a significant determinant of circulating ACE2. Measured covariates accounted for 17.3% of variation in circulating NEP. ACE and NEP were associated with systolic and diastolic BP in univariate analyses; however, only ACE was independently associated with systolic and diastolic BP after accounting for covariates and shared childhood household.
Importance of Salt in Determining Blood Pressure in Children
Authors: He Feng J. , MacGregor Graham A.
Published: September 2006

To assess the effect of reducing salt intake on blood pressure in children, we carried out a meta-analysis of controlled trials. Trials were included if participants were children (≤18 years), and duration of salt reduction must have been for ≥2 weeks. Mean effect size was calculated using a fixed-effect model, because there was no significant heterogeneity. Ten trials of children and adolescents with 966 participants were included (median age: 13 years; range: 8 to 16 years; median duration: 4 weeks; range: 2 weeks to 3 years). Salt intake was reduced by 42% (interquartile range [IQR]: 7% to 58%). There were significant reductions in blood pressure: systolic: −1.17 mm Hg (95% CI: −1.78 to −0.56 mm Hg;
P
<0.001); diastolic: −1.29 mm Hg (95% CI: −1.94 to −0.65 mm Hg;
P
<0.0001). Three trials of infants with 551 participants were included (median duration: 20 weeks; range: 8 weeks to 6 months). Salt intake was reduced by 54% (IQR: 51% to 79%). There was a significant reduction in systolic blood pressure: −2.47 mm Hg (95% CI: −4.00 to −0.94 mm Hg;
P
<0.01). This is the first meta-analysis of salt reduction in children, and it demonstrates that a modest reduction in salt intake causes immediate falls in blood pressure and, if continued, may well lessen the subsequent rise in blood pressure with age. This would result in major reductions in cardiovascular disease. These results in conjunction with other evidence provide strong support for a reduction in salt intake in children.
Relationship Between Postoperative Cardiac Troponin I Levels and Outcome of Cardiac Surgery
Authors: Croal Bernard L. , Hillis Graham S. , Gibson Patrick H. , Fazal Mohammed T. , El-Shafei Hussein , Gibson George , Jeffrey Robert R. , Buchan Keith G. , West Douglas , Cuthbertson Brian H.
Published: September 2006

Background—

Cardiac surgery may be associated with significant perioperative and postoperative morbidity and mortality. Underlying pathology, surgical technique, and postoperative complications may all influence outcome. These factors may be reflected as a rise in postoperative troponin levels. Interpretation of troponin levels in this setting may therefore be complex. This study assessed the prognostic significance of such measurements, taking into account potential confounding variables.

Methods and Results—

One-thousand three hundred sixty-five patients undergoing cardiac surgery underwent measurement of cardiac troponin I (cTnI) at 2 and 24 hours after surgery. The relationship of these measurements to subsequent mortality was established. After taking into account all other variables, cTnI levels measured at 24 hours were independently predictive of mortality at 30 days (odds ratio [OR] 1.14 per 10 μg/L, 95% confidence interval [CI] 1.05 to 1.24,
P
=0.002), 1 year (OR 1.10 per 10 μg/L, 95% CI 1.03 to 1.18,
P
=0.006), and 3 years (OR 1.07 per 10 μg/L, 95% CI 1.00 to 1.15,
P
=0.04). Cardiac TnI levels in the highest quartile at 24 hours were associated with a particularly poor outcome.

Conclusions—

cTnI levels measured 24 hours after cardiac surgery predict short-, medium-, and long-term mortality and remain independently predictive when adjusted for all other potentially confounding variables, including operation complexity.
Reduction in the Incidence of Acute Myocardial Infarction Associated With a Citywide Smoking Ordinance
Authors: Bartecchi Carl , Alsever Robert N. , Nevin-Woods Christine , Thomas William M. , Estacio Raymond O. , Bartelson Becki Bucher , Krantz Mori J.
Published: September 2006

Background—

Secondhand smoke exposure increases the risk of acute myocardial infarction (AMI). One study (Helena, Mont) examined the issue and found a decrease in AMI associated with a smoke-free ordinance. We sought to determine the impact of a smoke-free ordinance on AMI admission rates in another geographically isolated community (Pueblo, Colo).

Methods and Results—

We assessed AMI hospitalizations in Pueblo during a 3-year period, 1.5 years before and 1.5 years after implementation of a smoke-free ordinance. We compared the AMI hospitalization rates among individuals residing within city limits, the area where the ordinance applied, versus those outside city limits. We also compared AMI rates during this time period with another geographically isolated but proximal community, El Paso County, Colo, that did not have an ordinance. A total of 855 patients were hospitalized with a diagnosis of primary AMI in Pueblo between January 1, 2002, and December 31, 2004. A reduction in AMI hospitalizations was observed in the period after the ordinance among Pueblo city limit residents (relative risk [RR]=0.73, 95% confidence interval [CI] 0.63 to 0.85). No significant changes in AMI rates were observed among residents outside city limits (RR=0.85, 95% CI 0.63 to 1.16) or in El Paso County during the same period (RR=0.97, 95% CI 0.89 to 1.06). The reduction in AMI rate within Pueblo differed significantly from changes in the external control group (El Paso County) even after adjustment for seasonal trends (
P
<0.001).

Conclusions—

A public ordinance reducing exposure to secondhand smoke was associated with a decrease in AMI hospitalizations in Pueblo, Colo, which supports previous data from a smaller study.
Real-Time 2-Photon Imaging of Mitochondrial Function in Perfused Rat Hearts Subjected to Ischemia/Reperfusion
Authors: Matsumoto-Ida Madoka , Akao Masaharu , Takeda Toshihiro , Kato Masashi , Kita Toru
Published: September 2006

Background—

Mitochondria play pivotal roles in cell death; the loss of mitochondrial membrane potential (ΔΨ
m
) is the earliest event that commits the cell to death. Here, we report novel real-time imaging of ΔΨ
m
in individual cardiomyocytes within perfused rat hearts using 2-photon laser-scanning microscopy, which has unique advantages over conventional confocal microscopy: greater tissue penetration and lower tissue toxicity.

Methods and Results—

The Langendorff-perfused rat heart was loaded with a fluorescent indicator of ΔΨ
m
, tetramethylrhodamine ethyl ester. Tetramethylrhodamine ethyl ester was excited with an 810-nm line of a Ti:sapphire laser, and its fluorescence in the heart cells was successfully visualized up to ≈50 μm from the epicardial surface. Taking advantage of this system, we monitored the spatiotemporal changes of ΔΨ
m
in response to ischemia/reperfusion at the subcellular level. No-flow ischemia caused progressive ΔΨ
m
loss and a more prominent ΔΨ
m
loss on reperfusion. During ischemia/reperfusion, cells maintained a constant ΔΨ
m
for the cell-to-cell specific period of latency, followed by a rapid, complete, and irreversible ΔΨ
m
loss, and this process did not affect the neighboring cells. Within a cell, ΔΨ
m
loss was initiated in a particular area of mitochondria and rapidly propagated along the longitudinal axis. These spatiotemporal changes in ΔΨ
m
resulted in marked cellular and subcellular heterogeneity of mitochondrial function. Ischemic preconditioning reduced the number of cells undergoing ΔΨ
m
loss, whereas cyclosporin A partially inhibited ΔΨ
m
loss in each cell.

Conclusions—

Investigation of cellular responses in the natural environment will increase knowledge of ischemia/reperfusion injury and provide deeper insights into antiischemia/reperfusion therapy that targets mitochondria.
Association Between the UGT1A1*28 Allele, Bilirubin Levels, and Coronary Heart Disease in the Framingham Heart Study
Authors: Lin Jing-Ping , O’Donnell Christopher J. , Schwaiger Johannes P. , Cupples L. Adrienne , Lingenhel Arno , Hunt Steven C. , Yang Song , Kronenberg Florian
Published: September 2006

Background—

Bilirubin is an antioxidant that suppresses lipid oxidation and retards atherosclerosis formation. An inverse association between serum bilirubin and coronary heart disease has been reported. Linkage studies have identified a major locus at the chromosome 2q telomere that affects bilirubin concentrations. A candidate gene in the linkage region encodes hepatic bilirubin uridine diphosphate–glucuronosyltransferase (UGT1A1). The insertion of a TA in the TATAA box of the gene, an allele designated UGT1A1*28, decreases gene transcription. Individuals homozygous for UGT1A1*28 (genotype 7/7) have increased serum bilirubin levels compared with carriers of the 6 allele. To date, no significant association between UGT1A1*28 and cardiovascular disease (CVD) events has been reported. We performed an association study in the Framingham Heart Study population to investigate whether UGT1A1*28 is associated with the risk of CVD events.

Methods and Results—

The study population included 1780 unrelated individuals from the Offspring cohort (49% males, mean age 36 years at entry) who had been followed up for 24 years. Individuals with genotype 7/7 had significantly higher bilirubin levels (mean±SD 1.14±0.44 mg/dL) than those with genotypes 6/6 and 6/7 (mean±SD 0.69±0.27 mg/dL,
P
<0.01). Using the Cox proportional hazards model, we found significant associations between the UGT1A1*28 allele and decreased risk of CVD. Individuals with genotype 7/7 (population frequency of 11%) had approximately one third the risk for CVD and coronary heart disease as carriers of the 6 allele, which resulted in a hazard ratio (95% confidence interval) of 0.36 (0.18 to 0.74) and 0.30 (0.12 to 0.74), respectively.

Conclusions—

Homozygote UGT1A1*28 allele carriers with higher serum bilirubin concentrations exhibit a strong association with lower risk of CVD.
Impacts of Localized Mixing and Topography on the Stationary Abyssal Circulation
Authors: Katsman Caroline A.
Published: September 2006

Stommel and coworkers calculated the stationary, geostrophic circulation in the abyssal ocean driven by prescribed sources (representing convective downwelling sites) and sinks (slow, widespread upwelling through the thermocline). The applied basin geometries were highly idealized with nearly uniform upwelling and gradual bottom slopes. In this paper, the classical Stommel–Arons theory for the abyssal circulation is extended by introducing pronounced bathymetry in the form of a midocean ridge and strongly enhanced upwelling in the vicinity of this ridge, modeled after direct observations of diapycnal mixing rates in the deep ocean. Locally enhanced upwelling over a midocean ridge drives a β-plume circulation that is modified by topographic stretching. The dynamics of this abyssal circulation pattern are explained by analyzing the combined impacts of the upwelling pattern and the bathymetry on the stationary circulation, building on their well-known separate impacts. On the western flank of the ridge, the effects of topographic stretching and upwelling oppose, and the direction of the local flow depends on their relative size. In this paper, a simple theoretical estimate is derived that can predict the direction of the flow along the ridge based on the geometry of the basin and the upwelling region. Its applicability is demonstrated for both the idealized model configurations applied in this study and for more realistic model simulations.
Langston Hughes - Patternmaster
Authors: Scott Jonathan
Published: September 2006

In the US academy Langston Hughes is considered a great `folk poet'. This specialist sort of literary designation is not wrong; the problem is that it has come to replace the more historically accurate and generalist description of Hughes as one of the most well-rounded writers and intellectuals of the twentieth century. Outside the United States, Hughes is usually ranked alongside Eliot and Yeats, both in terms of overall intellectual influence within the English language and literature tradition and for his catholic literary output over the course of four decades of work. The thesis here is that the downgrading of Hughes in the US academy, from world-class writer and intellectual to `Negro folk poet', is not only symptomatic of the endurance of white racial oppression in US society, but also extremely costly for students and scholars of American literature who have thus far been made familiar with only a fraction of his writings.
Drug Pedigrees Are Here, but in What Form?
Authors: Stovall Sandra R.
Published: September 2006

This article traces the evolution of pedigree papers, primarily in Florida. It provides a brief chronology of the federal action and an in-depth analysis of the efforts in Florida up through passage of HB 371, which has not been acted on by the governor of Florida at submission time. Finally, reference is made to other state efforts, including California’s, in the fight against counterfeit and diverted drugs in this country’s supply chain.
Counterfeit Drugs and States’ Efforts to Combat the Problem
Authors: Catizone Carmen A.
Published: September 2006

State boards of pharmacy strive to reshape state regulation of wholesale distributors to maintain the security and integrity of the US medication distribution system. Despite being faced with a complicated situation of illegal importation of drugs, erosion of state and national borders, and a complete disregard for US federal and state laws by entities engaged in the production and distribution of counterfeit drugs, the National Association of State Boards of Pharmacy (NABP) and state boards of pharmacy are working to develop and implement more stringent laws and regulations for the licensure and regulation of wholesale distributors. In citing incidences of counterfeit drugs from a global perspective and efforts that NABP has taken to implement the Prescription Drug Marketing Act of 1988, this discussion will highlight NABP’s recent efforts to monitor counterfeit and adulterated drugs entering the US drug distribution system, recommendations emanating from NABP’s Task Force on Counterfeit Drugs and Pedigree Requirements, and its Verified-Accredited Wholesale Distributors program.