bluuebunny/crossref_metadata_2025 huggingface dataset:
Aerobic exercise training improves whole muscle and single myofiber size and function in older women
Authors: Harber Matthew P. , Konopka Adam R. , Douglass Matthew D. , Minchev Kiril , Kaminsky Leonard A. , Trappe Todd A. , Trappe Scott
Published: August 2009

To comprehensively assess the influence of aerobic training on muscle size and function, we examined seven older women (71 ± 2 yr) before and after 12 wk of cycle ergometer training. The training program increased ( P < 0.05) aerobic capacity by 30 ± 6%. Quadriceps muscle volume, determined by magnetic resonance imaging (MRI), was 12 ± 2% greater ( P < 0.05) after training and knee extensor power increased 55 ± 7% ( P < 0.05). Muscle biopsies were obtained from the vastus lateralis to determine size and contractile properties of individual slow (MHC I) and fast (MHC IIa) myofibers, myosin light chain (MLC) composition, and muscle protein concentration. Aerobic training increased ( P < 0.05) MHC I fiber size 16 ± 5%, while MHC IIa fiber size was unchanged. MHC I peak power was elevated 21 ± 8% ( P < 0.05) after training, while MHC IIa peak power was unaltered. Peak force (Po) was unchanged in both fiber types, while normalized force (Po/cross-sectional area) was 10% lower ( P < 0.05) for both MHC I and MHC IIa fibers after training. The decrease in normalized force was likely related to a reduction ( P < 0.05) in myofibrillar protein concentration after training. In the absence of an increase in Po, the increase in MHC I peak power was mediated through an increased ( P < 0.05) maximum contraction velocity (Vo) of MHC I fibers only. The relative proportion of MLC1s (Pre: 0.62 ± 0.01; Post: 0.58 ± 0.01) was lower ( P < 0.05) in MHC I myofibers after training, while no differences were present for MLC2s and MLC3f isoforms. These data indicate that aerobic exercise training improves muscle function through remodeling the contractile properties at the myofiber level, in addition to pronounced muscle hypertrophy. Progressive aerobic exercise training should be considered a viable exercise modality to combat sarcopenia in the elderly population.
Ductus arteriosus wave intensity analysis in fetal lambs: midsystolic ductal flow augmentation is due to antegrade pulmonary arterial wave transmission
Authors: Smolich Joseph J. , Mynard Jonathan P. , Penny Daniel J.
Published: August 2009

In midsystole, fetal pulmonary trunk (PT) and arterial (PA) blood flows characteristically fall, despite pulmonary blood pressure increasing, while ductus arteriosus (DA) flow continues to rise to a delayed peak. Wave intensity ( WI) analysis indicates that midsystolic fetal PT and PA flow reductions are related to a very large midsystolic PA backward-running compression wave (BCWms), which originates in the pulmonary microvasculature and is partially transmitted into the PT. This study tested the hypothesis that midsystolic augmentation of DA blood flow was related to transmission of the PA BCWmsinto the DA. DA, PT, and PA WI analysis was performed in eight anesthetized late-gestation fetal sheep instrumented with DA, PT, and left PA micromanometer catheters to measure pressure (P) and transit-time flow probes to obtain blood velocity ( U). In a subgroup ( n = 5), the main PA was briefly occluded to abolish wave transmission from the lungs. WI was calculated as the product of P and U rates of change. PA and PT WI profiles both contained a prominent BCWms, ∼5-fold larger in the PA ( P < 0.005), which increased P but decreased U. By contrast, the DA WI profile demonstrated a large midsystolic forward-running compression wave (FCWms), which increased DA P and U, and occurred 5 ms after PA BCWms. Furthermore, both DA FCWmsand PT BCWmswere abolished by main PA occlusion. These results suggest that the fetal PA BCWmsundergoes retrograde transmission into the PT as a BCWms, but antegrade transmission into the DA as a FCWmsthat augments midsystolic DA flow.
Oxalate-induced activation of PKC-α and -δ regulates NADPH oxidase-mediated oxidative injury in renal tubular epithelial cells
Authors: Thamilselvan Vijayalakshmi , Menon Mani , Thamilselvan Sivagnanam
Published: August 2009

Oxalate-induced oxidative stress contributes to cell injury and promotes renal deposition of calcium oxalate crystals. However, we do not know how oxalate stimulates reactive oxygen species (ROS) in renal tubular epithelial cells. We investigated the signaling mechanism of oxalate-induced ROS formation in these cells and found that oxalate significantly increased membrane-associated protein kinase C (PKC) activity while at the same time lowering cytosolic PKC activity. Oxalate markedly translocated PKC-α and -δ from the cytosol to the cell membrane. Pretreatment of LLC-PK1cells with specific inhibitors of PKC-α or -δ significantly blocked oxalate-induced generation of superoxide and hydrogen peroxide along with NADPH oxidase activity, LDH release, lipid hydroperoxide formation, and apoptosis. The PKC activator PMA mimicked oxalate's effect on oxidative stress in LLC-PK1cells as well as cytosol-to-membrane translocation of PKC-α and -δ. Silencing of PKC-α expression by PKC-α-specific small interfering RNA significantly attenuated oxalate-induced cell injury by decreasing hydrogen peroxide generation and LDH release. We believe this is the first demonstration that PKC-α- and -δ-dependent activation of NADPH oxidase is one of the mechanisms responsible for oxalate-induced oxidative injury in renal tubular epithelial cells. The study suggests that the therapeutic approach might be considered toward attenuating oxalate-induced PKC signaling-mediated oxidative injury in recurrent stone formers.
Mice lacking mPGES-1 are resistant to lithium-induced polyuria
Authors: Jia Zhanjun , Wang Haiping , Yang Tianxin
Published: August 2009

Cyclooxygenase-2 activity is required for the development of lithium-induced polyuria. However, the involvement of a specific, terminal prostaglandin (PG) isomerase has not been evaluated. The present study was undertaken to assess lithium-induced polyuria in mice deficient in microsomal prostaglandin E synthase-1 (mPGES-1). A 2-wk administration of LiCl (4 mmol·kg−1·day−1ip) in mPGES-1 +/+ mice led to a marked polyuria with hyposmotic urine. This was associated with elevated renal mPGES-1 protein expression and increased urine PGE2excretion. In contrast, mPGES-1 −/− mice were largely resistant to lithium-induced polyuria and a urine concentrating defect, accompanied by nearly complete blockade of high urine PGE2and cAMP output. Immunoblotting, immunohistochemistry, and quantitative (q) RT-PCR consistently detected a significant decrease in aquaporin-2 (AQP2) protein expression in both the renal cortex and medulla of lithium-treated +/+ mice. This decrease was significantly attenuated in the −/− mice. qRT-PCR detected similar patterns of changes in AQP2 mRNA in the medulla but not in the cortex. Similarly, the total protein abundance of the Na-K-2Cl cotransporter (NKCC2) in the medulla but not in the cortex of the +/+ mice was significantly reduced by lithium treatment. In contrast, the dowregulation of renal medullary NKCC2 expression was significantly attenuated in the −/− mice. We conclude that mPGES-1-derived PGE2mediates lithium-induced polyuria likely via inhibition of AQP2 and NKCC2 expression.
Working around the clock: circadian rhythms and skeletal muscle
Authors: Zhang Xiping , Dube Thomas J. , Esser Karyn A.
Published: August 2009

The study of the circadian molecular clock in skeletal muscle is in the very early stages. Initial research has demonstrated the presence of the molecular clock in skeletal muscle and that skeletal muscle of a clock-compromised mouse, Clock mutant, exhibits significant disruption in normal expression of many genes required for adult muscle structure and metabolism. In light of the growing association between the molecular clock, metabolism, and metabolic disease, it will also be important to understand the contribution of circadian factors to normal metabolism, metabolic responses to muscle training, and contribution of the molecular clock in muscle-to-muscle disease (e.g., insulin resistance). Consistent with the potential for the skeletal muscle molecular clock modulating skeletal muscle physiology, there are findings in the literature that there is significant time-of-day effects for strength and metabolism. Additionally, there is some recent evidence that temporal specificity is important for optimizing training for muscular performance. While these studies do not prove that the molecular clock in skeletal muscle is important, they are suggestive of a circadian contribution to skeletal muscle function. The application of well-established models of skeletal muscle research in function and metabolism with available genetic models of molecular clock disruption will allow for more mechanistic understanding of potential relationships.
Substantia Nigra Output to Prefrontal Cortex Via Thalamus in Monkeys. I. Electrophysiological Identification of Thalamic Relay Neurons
Authors: Tanibuchi Ikuo , Kitano Hiroyuki , Jinnai Kohnosuke
Published: August 2009

A few studies have been performed in primate basal ganglia–thalamo–prefrontal pathways. Nevertheless, their electrophysiological properties and anatomical arrangements remain obscure. This study examined them in nigro-thalamo-cortical pathways from the substantia nigra pars reticulata (SNr) to the frontal cortex (FRC) via the mediodorsal (MD) and ventral anterior (VA) thalamus in monkeys. First, single thalamocortical neurons with SNr input were identified by antidromic responses to FRC stimulation and by inhibitory orthodromic responses with short latencies (<5 ms) to SNr stimulation. Second, single nigrothalamic neurons were found by antidromic responses to stimulation of the portions of the MD and VA where the thalamocortical neurons were recorded. The inhibitory orthodromic responses in the thalamocortical neurons were considered to be monosynaptically induced by nigral stimulation because the latency distribution of the orthodromic responses in the thalamocortical neurons was similar to that of the antidromic responses in the nigrothalamic neurons. Almost all relay neurons in the rostrolateral MD received inhibitory afferents from the caudolateral SNr and projected to the prefrontal area ventral to the principal sulcus, which constituted the densest nigro-thalamo-cortical projections. Meanwhile, neurons in the VA received inhibitory signals from the whole rostrocaudal extent of the SNr and projected to wide regions of the FRC; neurons in its pars magnocellularis mostly projected to different prefrontal areas, while those in its pars parvocellularis projected to motor areas. This report substantiated the topography of thalamocortical neurons monosynaptically receiving inhibitory SNr input and projecting to the FRC in the primate MD and VA at the single-neuron level.
Chemotherapy of Human African Trypanosomiasis
Authors: Bacchi Cyrus J.
Published: August 2009

Human Africa trypanosomiasis is a centuries-old disease which has disrupted sub-Saharan Africa in both physical suffering and economic loss. This article presents an update of classic chemotherapeutic agents, in use for >50 years and the recent development of promising non-toxic combination chemotherapy suitable for use in rural clinics.
Removal of Organic Impurities from Water Using a Reactor with Photoactive Refill
Authors: Grzechulska-Damszel Joanna
Published: August 2009

The aim of the presented work was the removal of phenol from water using a reactor with photoactive refill. Titanium dioxide (Chemical Factory “Police” Poland) was immobilized on the base material as a thin layer from the alcoholic suspension followed by thermal stabilization. The glass fabric was applied as a support for the titania coating.
The results of studies revealed that the titania coatings show a high photocatalytic activity toward the phenol decomposition in water. The complete removal of phenol was achieved in the relatively short time of 23 hours. The prepared coatings exhibit high stability in repeated cycles of water treatment. The proposed reactor with photoactive refill solves the problem of necessity of replacement of the reactor or the parts of the reactor when the photocatalysts activity decreases. In the case of activity drop of the photocatalyst, only the photoactive refill can be easily replaced.
Generation of Useful Hydrocarbons and Hydrogen during Photocatalytic Decomposition of Acetic Acid on CuO/Rutile Photocatalysts
Authors: Mozia Sylwia
Published: August 2009

The presented
studies have focused on a photocatalytic
generation of useful hydrocarbons, mainly
methane and ethane, from acetic acid under
N2 atmosphere. CuO‐loaded rutile, as well as unmodified rutile and anatase‐phase TiO2 photocatalysts were applied in the experiments. The
efficiency of the catalysts towards methane generation changed in
the following order: Cu‐TiO2 (10% Cu) > crude TiO2 ≈ Cu‐TiO2 (20% Cu) > Cu‐TiO2 (5% Cu) > rutile. The amount of CH4 produced in the presence of the catalyst containing 10 wt% of Cu was higher for ca. 33% than in case of pure rutile. The concentration of ethane was 14–16 times lower than the amount of methane, regardless of the catalyst used. Low concentrations of hydrogen were also detected in the gaseous mixtures. After 5 hours of the process conducted with the catalyst containing 5–20 wt% of Cu the concentration of hydrogen amounted to 0.06–0.14 vol.%, respectively.
A Comparative Analysis of Seismological and Gravimetric Crustal Thicknesses below the Andean Region with Flat Subduction of the Nazca Plate
Authors: Gimenez Mario E. , Braitenberg Carla , Martinez M. Patricia , Introcaso Antonio
Published: August 2009

A gravimetric study was carried out in a region of the Central Andean Range between28∘and32∘south latitudes and from72∘and66∘west longitudes. The seismological and gravimetrical Moho models were compared in a sector which coincides with the seismological stations of the CHARGE project. The comparison reveals discrepancies between the gravity Moho depths and those obtained from seismological investigations (CHARGE project), the latter giving deeper values than those resulting from the gravimetric inversion. These discrepancies are attenuated when the positive gravimetric effect of the Nazca plate is considered. Nonetheless, a small residuum of about 5 km remains beneath the Cuyania terrane region, to the east of the main Andean chain. This residuum could be gravimetrically justified if the existence of a high density or eclogitized portion of the lower crust is considered. This result differed from the interpretations from Project “CHARGE” which revealed that the entire inferior crust extending from the Precordillera to the occidental “Sierras Pampeanas” could be “eclogitized”. In this same sector, we calculated the effective elastic thickness (Te) of the crust. These results indicated an anomalous value of Te = 30 km below the Cuyania terrane. This is further conclusive evidence of the fact that the Cuyania terrane is allochthonous, for which also geological evidences exist.
On the Characterization of Hankel and Toeplitz Operators Describing Switched Linear Dynamic Systems with Point Delays
Authors: De la Sen M.
Published: August 2009

This paper investigates the causality properties of a class of linear time‐delay systems under constant point delays which possess a finite set of distinct linear time‐invariant parameterizations (or configurations) which,
together with some switching function, conform a linear time‐varying switched dynamic system. Explicit expressions
are given to define pointwisely the causal and anticausal Toeplitz and Hankel operators from the set of switching time instants generated from the switching function. The case of the auxiliary unforced system defined by the matrix of undelayed dynamics being dichotomic (i.e., it has no eigenvalue on the complex imaginary axis) is considered in detail. Stability conditions as well as dual instability ones are discussed for this case which guarantee that the whole system is either stable, or unstable but no configuration of the switched system has eigenvalues within some vertical strip including the imaginary axis. It is proved that if the system is causal and uniformly controllable and observable, then it is globally asymptotically Lyapunov stable independent of the delays, that is, for any possibly values of such delays, provided that a minimum residence time in‐between consecutive switches is kept or if all the set of matrices describing the auxiliary unforced delay—free system parameterizations commute pairwise.
Expression and Purification of Active Recombinant Cathepsin C (Dipeptidyl Aminopeptidase I) of Kuruma Prawn Marsupenaeus japonicus in Insect Cells
Authors: Qiu Gao-Feng , Feng Hai-Yang , Yamano Keisuke
Published: August 2009

Cathepsin C (CTSC) is a lysosomal cysteine protease belonging to the papain superfamily. Our previous study showed that CTSC precursor (zymogen) is localized exclusively in cortical rods (CRs) of mature oocyte in the kuruma prawn Marsupenaeus japonicus, suggesting that CTSC might have roles on regulating release and/or formation of a jelly layer. In this study, enzymically active CTSC of the kuruma prawn was prepared by recombinant expression in the High Five insect cell line. The recombinant enzyme with a polyhistidine tag at its C‐terminus was considered to be initially secreted into the culture medium as an inactive form of zymogen, because Western blot with anti‐CTSC antibody detected a 51 kDa protein corresponding to CTSC precursor. After purification by affinity chromatography on nickel‐iminodiacetic acid resin, the enzyme displayed three forms of 51, 31, and 30 kDa polypeptides. All of the forms can be recognized by antiserum raised against C‐terminal polyhistidine tag, indicating that the 31 and 30 kDa forms were generated from 51 kDa polypeptide by removal of a portion of the N‐terminus of propeptide. Following activation at pH 5.5 and 37∘C for 40 hours under native conditions, the recombinant CTSC (rCTSC) exhibited increased activity against the synthetic substrate Gly‐Phe‐β‐naphthylamide and optimal pH at around 5. The purified rCTSC will be useful for further characterization of its exact physiological role on CRs release and/or formation of a jelly layer in kuruma prawn.
Suboptimal Rate Adaptive Resource Allocation for Downlink OFDMA Systems
Authors: Sadr Sanam , Anpalagan Alagan , Raahemifar Kaamran
Published: August 2009

This paper aims to
study the performance of low complexity adaptive
resource allocation in the downlink of OFDMA
systems with fixed or variable rate requirements
(with fairness consideration). Two suboptimal
resource allocation algorithms are proposed
using the simplifying assumption of transmit
power over the entire bandwidth. The objective
of the
first algorithm is to maximize the total throughput while
maintaining rate proportionality among the users. The proposed
suboptimal algorithm prioritizes the user with the highest
sensitivity to the subcarrier allocation, and the variance over the
subchannel gains is used to define the sensitivity of each user.
The second algorithm concerns rate adaptive resource allocation in
multiuser systems with fixed rate constraints. We propose a
suboptimal joint subchannel and power allocation algorithm which
prioritizes the users with the highest required data rates. The main
feature of this algorithm is its low complexity while achieving
the rate requirements.
MicroRNAs in Cardiovascular Biology and Heart Disease
Authors: Catalucci Daniele , Gallo Paolo , Condorelli Gianluigi
Published: August 2009

MicroRNAs play important roles in many cellular and biological functions via the regulation of mRNA target translation. In the cardiovascular field, microRNAs are now acknowledged as fundamental in regulating the expression of genes that governs physiological and pathological myocardial adaptation to stress. Here, we review recent progress in the understanding of microRNA functions and their involvement in heart disease.
Propranolol Decreases Tachycardia and Improves Symptoms in the Postural Tachycardia Syndrome
Authors: Raj Satish R. , Black Bonnie K. , Biaggioni Italo , Paranjape Sachin Y. , Ramirez Maricelle , Dupont William D. , Robertson David
Published: August 2009

Background—

Postural tachycardia syndrome (POTS) induces disabling chronic orthostatic intolerance with an excessive increase in heart rate on standing. β-Blockade is an appealing treatment approach, but conflicting preliminary reports are conflicting. We tested the hypothesis that propranolol will attenuate the tachycardia and improve symptom burden in patients with POTS. In protocol 1, a low dose (20 mg) was compared with placebo, and the dose response was assessed in protocol 2.

Methods and Results—

In protocol 1, patients with POTS (n=54) underwent acute drug trials of propranolol 20 mg orally and placebo, on separate mornings, in a randomized crossover design. Blood pressure, heart rate, and symptoms were assessed while the patients were seated and after standing for up to 10 minutes before and hourly after the study drug. Supine (
P
<0.001) and standing (
P
<0.001) heart rates were significantly lower after propranolol compared with placebo. The symptom burden improvement from baseline to 2 hours was greater with propranolol than placebo (median, −4.5 versus 0 arbitrary units;
P
=0.044). In protocol 2, 18 patients with POTS underwent similar trials of high-dose (80 mg) versus low-dose (20 mg) propranolol. Although the high dose elicited a greater decrease than the low dose in standing heart rate (
P
<0.001) and orthostatic tachycardia (
P
<0.001), the improvement in symptoms at 2 hours was greater with low-dose propranolol (−6 versus −2 arbitrary units;
P
=0.041).

Conclusions—

Low-dose oral propranolol significantly attenuated tachycardia and improved symptoms in POTS. Higher-dose propranolol did not further improve, and may worsen, symptoms.
T-Type Ca
2+
Channel Blockade Prevents Sudden Death in Mice With Heart Failure
Authors: Kinoshita Hideyuki , Kuwahara Koichiro , Takano Makoto , Arai Yuji , Kuwabara Yoshihiro , Yasuno Shinji , Nakagawa Yasuaki , Nakanishi Michio , Harada Masaki , Fujiwara Masataka , Murakami Masao , Ueshima Kenji , Nakao Kazuwa
Published: August 2009

Background—

Pharmacological interventions for prevention of sudden arrhythmic death in patients with chronic heart failure remain limited. Accumulating evidence suggests increased ventricular expression of T-type Ca
2+
channels contributes to the progression of heart failure. The ability of T-type Ca
2+
channel blockade to prevent lethal arrhythmias associated with heart failure has never been tested, however.

Methods and Results—

We compared the effects of efonidipine and mibefradil, dual T- and L-type Ca
2+
channel blockers, with those of nitrendipine, a selective L-type Ca
2+
channel blocker, on survival and arrhythmogenicity in a cardiac-specific, dominant-negative form of neuron-restrictive silencer factor transgenic mice (dnNRSF-Tg), which is a useful mouse model of dilated cardiomyopathy leading to sudden death. Efonidipine, but not nitrendipine, substantially improved survival among dnNRSF-Tg mice. Arrhythmogenicity was dramatically reduced in dnNRSF-Tg mice treated with efonidipine or mibefradil. Efonidipine acted by reversing depolarization of the resting membrane potential otherwise seen in ventricular myocytes from dnNRSF-Tg mice and by correcting cardiac autonomic nervous system imbalance. Moreover, the
R
(−)-isomer of efonidipine, a recently identified, highly selective T-type Ca
2+
channel blocker, similarly improved survival among dnNRSF-Tg mice. Efonidipine also reduced the incidence of sudden death and arrhythmogenicity in mice with acute myocardial infarction.

Conclusions—

T-type Ca
2+
channel blockade reduced arrhythmias in a mouse model of dilated cardiomyopathy by repolarizing the resting membrane potential and improving cardiac autonomic nervous system imbalance. T-type Ca
2+
channel blockade also prevented sudden death in mice with myocardial infarction. Our findings suggest T-type Ca
2+
channel blockade is a potentially useful approach to preventing sudden death in patients with heart failure.
Upregulation of Matrix Metalloproteinase-2 in the Arterial Vasculature Contributes to Stiffening and Vasomotor Dysfunction in Patients With Chronic Kidney Disease
Authors: Chung Ada W.Y. , Yang H.H. Clarice , Kim Jong Moo , Sigrist Mhairi K. , Chum Elliott , Gourlay William A. , Levin Adeera
Published: August 2009

Background—

Cardiovascular disease is the leading cause of mortality in chronic kidney disease patients on maintenance dialysis. Given the importance of matrix metalloproteinase-2 (MMP-2) in matrix integrity, vascular cell function, and structural stability, we hypothesized that MMP-2 was elevated in the macrovasculature in dialyzed chronic kidney disease patients compared with chronic kidney disease patients not on dialysis and kidney donors.

Methods and Results—

Arteries from live kidney donors (A
donor
; n=30) and recipients (nondialysis [A
nondialyzed
], n=17; dialysis [A
dialyzed
], n=23 [peritoneal dialysis, n=10; hemodialysis, n=13]) were harvested during the transplantation procedure. Compared with A
donor
, MMP-2 upregulation was evident in both recipient groups. Protein expression of latent plus active MMP-2 in A
dialyzed
was 2-fold that in A
nondialyzed
. MMP-2 activity increased with length of dialysis (
r
=0.573,
P
=0.004). In A
dialyzed
, medial elastic fiber fragmentation was pronounced, and the ratio of external elastic lamina to media was negatively correlated with MMP-2 activity (
r
=−0.638,
P
=0.001). A
dialyzed
was 25% stiffer than A
nondialyzed
; this increased stiffness correlated with MMP-2 activity (
r
=0.728,
P
<0.0001) and the severity of medial calcium deposition (
r
=0.748,
P
=0.001). The contractile function and endothelium-dependent relaxation were reduced by 35% to 55% in A
dialyzed
and were negatively associated with MMP-2 activity (
r
=−0.608,
P
=0.002;
r
=−0.520,
P
=0.019, respectively). Preincubation with MMP-2 inhibitor significantly improved contractility and relaxation in A
dialyzed
.

Conclusions—

We describe a strong correlation between MMP-2 activation and elastic fiber disorganization, stiffness, calcification, and vasomotor dysfunction in the arterial vasculature in dialyzed chronic kidney disease patients. These findings may contribute to an improved understanding of mechanisms important in vascular health in chronic kidney disease patients.
Chronic Treatment With Losartan Results in Sufficient Serum Levels of the Metabolite EXP3179 for PPARγ Activation
Authors: Kappert Kai , Tsuprykov Oleg , Kaufmann Jan , Fritzsche Jan , Ott Ingo , Goebel Matthias , Bähr Ilse Nirmala , Häßle Paul-Laszlo , Gust Ronald , Fleck Eckart , Unger Thomas , Stawowy Philipp , Kintscher Ulrich
Published: August 2009

The losartan metabolite EXP3174 exhibits angiotensin II receptor 1 (AT1R)-blocking properties, whereas the metabolite EXP3179 potently induces the activity of the insulin-sensitizing peroxisome proliferator-activated receptor γ (PPARγ) as a partial agonist in vitro. We investigated whether chronic treatment with losartan leads to sufficient serum levels of EXP3179 to activate PPARγ in monocytes derived from losartan-treated patients. Hypertensive patients (n=15) treated with losartan (100 mg/daily for at least the past 2 months) and untreated control patients (n=7) were included. Monocytes were extracted by negative isolation using a Dynal Monocyte Kit, followed by analysis of PPARγ target gene expression (CD36, ABC transporter G1 [ABCG1]) by quantitative real-time RT-PCR. Serum was prepared before, 2, 4, and 6 hours after losartan (100 mg) ingestion for HPLC-based determination of losartan, EXP3174, and EXP3179. Chronic treatment with losartan resulted in basal levels of losartan, EXP3174, and EXP3179 of 348.3±101.8 ng/mL, 115.3±56.1 ng/mL, and 176.2±143.4 ng/mL, respectively. Levels of both EXP3174 and EXP3179 were time-dependently increased in serum with a maximum 2 hours after drug intake (1706.0±760.1 ng/mL, 808.9±618.2 ng/mL, respectively). In consonance with detectable PPARγ-activating EXP3179 serum levels, monocytic PPARγ target gene expression was significantly upregulated in patients treated with losartan by 3.75±0.95- and 252.02±46.86-fold for CD36 and ABCG1 (
P
=0.043,
P
=0.0045 versus control patients, respectively). This is the first clinical description of monocytic PPARγ-target gene regulation by chronic treatment with losartan, which likely is mediated by its metabolite EXP3179. Our data show that sufficient serum levels of EXP3179 are present under losartan treatment. PPARγ activation by AT1R-blockers may translate into synergistic beneficial actions in monocytes.
Evidence for Increased Methylglyoxal in the Vasculature of Women With Preeclampsia
Authors: Sankaralingam Sowndramalingam , Xu Han , Jiang Yanyan , Sawamura Tatsuya , Davidge Sandra T.
Published: August 2009

Preeclampsia is characterized by vascular endothelial dysfunction partly attributed to oxidative stress. In the vasculature of preeclamptic women, we have shown increased lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1) and arginase expression, which can contribute to vascular oxidative stress. However, the mechanisms of such upregulation are unknown. Methylglyoxal (MG) that plays a role in the vascular complications of diabetes mellitus and the development of hypertension can be one potential factor that can affect LOX-1 and arginase through its ability to induce oxidative stress in vascular cells. MG also reacts with lysine residues in proteins to generate advanced glycation end product, N
ε
-carboxy ethyl lysine, which also serves as a marker of MG. We hypothesized that markers of MG formation will be increased in the vasculature of preeclamptic women and that exogenous MG will induce oxidative stress by the upregulation of LOX-1 via arginase. We observed increased N
ε
-carboxy ethyl lysine expression in the vasculature of women with preeclampsia in comparison with normotensive pregnant women. Moreover, glyoxalase I and II, enzymes that detoxify MG, and glutathione reductase, which generates reduced glutathione, a cofactor for glyoxalase, are also reduced in preeclampsia. In cultured endothelial cells, MG increased arginase expression by 6 hours and LOX-1 expression by 24 hours. Inhibition of arginase or NO synthase significantly reduced MG-induced LOX-1 expression, superoxide levels, and nitrotyrosine staining. In conclusion, MG-induced LOX-1 expression is mediated via arginase upregulation likely because of uncoupling of NO synthase, which may have implications in preeclampsia.
Arterial Destiffening With Atorvastatin in Overweight and Obese Middle-Aged and Older Adults
Authors: Orr Jeb S. , Dengo A. Laura , Rivero Jose M. , Davy Kevin P.
Published: August 2009

We hypothesized that atorvastatin (ATOR) treatment would reduce arterial stiffness in overweight and obese middle-aged and older adults. Twenty-six (11 men and 15 women) overweight or obese (body mass index: 31.6±0.7 kg/m
2
) middle-aged and older adults (age: 54±2 years) were randomly assigned to receive either ATOR (80 mg/d) or placebo for 12 weeks. Arterial stiffness (β-stiffness and pulse wave velocity) was measured before and after the intervention. At baseline, the ATOR (n=16) and placebo (n=10) groups did not differ with respect to age, body mass index, blood pressure, serum lipid and lipoprotein concentrations, high-sensitivity C-reactive protein, indices of arterial stiffness, or compliance (all
P
>0.05). After the 12-week treatment period, the ATOR group experienced a 47% reduction in low-density lipoprotein cholesterol (149±6 to 80±8 mg/dL) and a 42% reduction in high-sensitivity C-reactive protein (3.6±0.8 to 2.1±0.5 mg/L; both
P
<0.05). In addition, β-stiffness (9.4±0.6 to 7.6±0.5 U) and aortic pulse wave velocity (1096±36 to 932±32 cm/s), but not brachial pulse wave velocity, decreased (both
P
<0.05) with ATOR. In contrast, there were no significant changes in β-stiffness (9.1±0.8 to 9.1±0.7 U) or aortic pulse wave velocity (1238±89 to 1191±90 cm/s; both
P
>0.05) in the placebo group. There were no relations between the reductions in arterial stiffness indices and any of the baseline cardiometabolic risk factors (all
P
>0.05). However, the reductions in arterial stiffness were correlated with the reduction in low-density lipoprotein cholesterol but not high-sensitivity C-reactive protein or any other cardiometabolic variables (all
P
<0.05). Taken together, these findings suggest that ATOR reduces arterial stiffness in overweight and obese middle-aged and older adults, and these favorable changes occur irrespective of baseline cardiometabolic risk factors.
The Effects of Adapting to Complex Motions: Position Invariance and Tuning to Spiral Motions
Authors: Snowden Robert J. , Milne Alan B.
Published: August 2009

Recent neurophysiological evidence (e.g., Graziano, Andersen, & Snowden, 1994) suggested that some cells in the medial superior temporal area (MST) of the Old World monkey are sensitive to complex motions such as those brought about by a surface moving in depth or rotating. Two important findings were that these cells show position invariance (i.e., their preferred stimulus does not change across the receptive field), and that some cells were selective for “spiralling” stimuli rather than pure rotations or pure expansion/contractions. This paper attempts to provide evidence for similar processes in the human visual system by employing the technique of selective adaptation. We have simulated surfaces undergoing a motion in depth (div) or a rotation (curl), but have removed any cues that are not related to global motion. After adapting to a large pattern undergoing, say, an expansion, an aftereffect that contained an element of contraction could be elicited by placing small test patterns anywhere in the adapted area. This suggests that the global structure of the motion field must have been encoded as well as the local motion. Likewise thresholds for detecting motions similar to the adapting motion were elevated across the adapted area, while thresholds for other motions were not. Hence the effects of adaptation are both selective and show a degree of position invariance. Adaptation to pure div or pure curl stimuli was compared with adaptation to spiralling stimuli. Threshold elevation was always selective for the adapting motion and the shape and broadness of tuning did not vary. In simulations we could not reproduce our results using a model that had only div and curl detectors, but we could reproduce them if we allowed for detectors tuned for a broad range of spiral pitches. Our results suggest that humans encode the complex motion of surfaces by detectors tuned to many different types of motion and that the detectors are invariant across space in their properties.
Magical Realism in Ghādah al-Sammān's The Square Moon
Authors: Suyoufie Fadia
Published: August 2009

This study focuses on the use of magical realism as a means of investigating reality in Ghādah al-Sammān's collection of short stories entitled The Square Moon (al-Qamar al-Murabba'). While her stories suggest new perspectives for what is normally considered "real" through their evocation of "wonder" (al-dahshah), al-Sammān's ultimate goal is to critique contemporary Arab society. Each of her stories targets several problems which are the result of cultural, social, and economic conditions in the Arab world. Conceiving al-Sammān's work in a postmodern/postcolonial context, the study tackles themes of the supernatural, exile, identity, and gender. In conclusion, it is argued that al-Sammān perceives herself as a medium whose conjuring of the magical and the supernatural infuses new energy into our apparently exhausted world.
The de Jure 'Artist' of the Bobrinski Bucket: Production and Patronage of Metalwork in pre-Mongol Khurasan and Transoxiana
Authors: Kana'an Ruba
Published: August 2009

The Bobrinski bucket, made in Herat in 599/1163, is one of the most iconic metalwork objects studied by historians of Islamic art. To date, art historical scholarship on the bucket has focused on interpreting its decorative programme and identifying the decorator, Mas'ud ibn Ahmad, whose name is inscribed on the bucket, as the 'artist' who had the intellectual property of the design and its application. In this essay, I investigate the meaning of signatures left by 'artists' by examining the range of possible relationships between four men whose names appear in the dedication inscription of the Bobrinski bucket. The legal writings of Hanafī jurists from Khurasan and Transoxiana, including al-Sarakhsī (d. ca. 1090), provide an important, and hitherto unexplored, source for understanding the legal rights and responsibilities of the different parties involved in the production of a metalwork object from conception to final product, including the stages of commissioning, manufacture, sale, and repair. The treatment by Muslim jurists of the different forms of trade provides a better understanding of the potential legal and contractual capacity in which a metalwork artist could sign his work.
Gender and Legal Authority: An Examination of Early Juristic Opposition to Women's Hadīth Transmission
Authors: Sayeed Asma
Published: August 2009

This article analyzes two cases of early juristic opposition to the legal authority of hadīth narrated by women. These cases appear as striking anomalies for two reasons: first, jurists broadly agreed that the gender of narrators in a chain of transmission was not a criterion in evaluating hadīth; and second, the cases involve female Companions of the Prophet whose value as transmitters came to be universally acknowledged by Muslim scholars of the classical period. In this article, I demonstrate that these incidents of gender-based disparagement are more useful because of what they reveal about the development of hadīth transmission (riwāya) and legal testimony (shahāda) as technical categories rather than for what they can tell us about normative gender discourse in early and classical Islam. I also contextualize the cases in terms of early methodological debates on the legal authority of isolated reports (khabar al-wāhid, akhbār al-ahād).
Cultural and Moral Authority: The Presumption of Television
Authors: Morrison David E.
Published: August 2009

This article shows how British television has lost cultural authority due to social shifts in British society whereby no single moral voice can expect to find an audience. The author argues that there is no longer a moral language by which to address moral issues nor any common agreement about the rightful constitution of the cultural and moral universe. The central point is that technological development leading to increase in television channel proliferation did not fragment the audience, as is often assumed, but that it was the fragmentation of the audience that allowed the uptake of the varied and various channels.
Sharing and Showing: Television as Monstration
Authors: Dayan Daniel
Published: August 2009

This article presents a comparison between two models of publicness (one based on a type of television firmly anchored in the center, another depending on media that blur all distinctions between centers and peripheries) and asks what sort of sharedness do these two models allow? The article also explores the notion of “monstration.” Through what sorts of displays do contending media call on public attention? Can one speak of “acts of showing” the way one speaks of speech acts? What is the impact of such acts on a sociology of collective attention? Third, the article examines the coexistence between television of the center and new digital media. Is their relation agonistic or, paradoxically, cooperative? The present situation may echo many earlier cases in which old media learned to coexist with new media by starting unexpected dialogues and practicing a division of labor. Today’s situation might be a (reluctant) partnership in a multitiered public sphere.
Television, Public Participation, and Public Service: From Value Consensus to the Politics of Identity
Authors: Lunt Peter
Published: August 2009

The proliferation of popular television genres in which the public are key participants (talk shows, reality TV, and makeover and lifestyle television) on the surface may seem less to do with engagement and more to do with entertainment and voyeurism. However, this article explores an alternative to the idea that popular television based on personal experience is a marker of the end of television in general and the weakening of the public service tradition in particular. Two programs, Oprah! and Little Angels, are shown to address the agendas of reflexive modernity and governmentality and potentially to contribute to a normative social order based on the project of the self. The fact that both traditional public service providers and commercial channels are engaging with these social issues suggests that new ways of legitimizing television in the public interest are emerging, with implications for the character of public service television.
Contextualizing the Broadcast Era: Nation, Commerce, and Constraint
Authors: Uricchio William
Published: August 2009

Programming scarcity that characterized the broadcast era, or what this article refers to as constraint , served very different goals. Often intertwined, these goals ranged from the formation of an ideologically coherent national public, to the protection of economic self-interest, to the explicit promotion of products and messages. They were deployed rather differently in the commercial American and state/public European spaces of television. The article explores a number of assumptions regarding the institution and medium of television that have persisted from the broadcast era into our own and that might well, given the very different structures of contemporary television, be repositioned. It outlines the contours of that repositioning, sketching the implications for some of our theoretical and methodological defaults.
We Liked to Watch: Television as Progenitor of the Surveillance Society
Authors: Meyrowitz Joshua
Published: August 2009

The rise of mass television allowed hundreds of millions of people to closely watch other people and places on a regular basis, anonymously and from afar. Television watching altered the balance of what different types of people knew about each other and relative to each other, blurred the dividing line between public and private behaviors, and weakened the link between physical location and access to social experience. In these ways, television contributed to the reshuffling of previously taken-for-granted reciprocal social roles, including those related to age, gender, and authority. In cultivating its viewers into the normalcy of the acts of watching and of being watched, television experience also stimulated the widespread use of more recent interactive visual media, including the displays of self on social networking sites. Moreover, familiarity with television as a watching machine has fostered the otherwise surprising level of tolerance for increasingly pervasive government, corporate, and populace surveillance.
Investigation on Effects of Variables on Shear Capacity of Precracked RC T-Beams with Externally Bonded Bi-directional CFRP Discrete Strips
Authors: Jayaprakash J. , Samad Abdul Aziz Abdul , Abbasvoch Ashrabov Anvar
Published: August 2009

This study aims to investigate the shear performance of partially precracked Reinforced Concrete (RC) T-beams bonded externally with bi-directional Carbon Fiber Reinforced Polymer (CFRP) discrete strips. A series of twelve RC T-beams are fabricated with internal transverse steel reinforcement and subjected to four-point and three-point bending systems. The external CFRP reinforcement strips are applied on the web and soffit of the beam with two-component epoxy system. The parameters investigated in the experimental program included (i) longitudinal tensile reinforcement ratio, (ii) shear span to effective depth ratio, (iii) spacing, and (iv) orientation of discrete CFRP strips. The experimental results show that the bi-directional CFRP discrete strip reinforcement significantly increases the shear capacity between 18 and 54% over the control beams. It is found that the test variables have significantly influenced the shear capacity of the CFRP strengthened beams. This study also validates the obtained experimental results with different existing theoretical models.
Abrasive Wear Behavior of Al-4.5 wt% Cu/(Zircon Sand + Silicon Carbide) Hybrid Composite
Authors: Das Sanjeev , Das Karabi , Das Siddhartha
Published: August 2009

In the present investigation the abrasive wear behavior of Al-4.5 wt% Cu alloy-based hybrid composites reinforced with zircon sand and silicon carbide particles has been studied. The abrasive wear resistance of these hybrid composites has been found to be better than that of Al-4.5 wt% Cu alloy without reinforcement. It has been also found that the size and morphology of the reinforcement particles has a significant effect on the abrasive wear resistance of the hybrid composites. The worn surfaces of the hybrid composites have been studied under a scanning electron microscope and it has been found that the wear is mainly due to the ploughing of the surface by abrading silicon carbide particles.
Delamination Analysis in Drilling of CFRP Composites Using Response Surface Methodology
Authors: Krishnamoorthy A. , Boopathy S. Rajendra , Palanikumar K.
Published: August 2009

Carbon fiber reinforced plastic (CFRP) composite materials are finding increased applications in many industries due to their excellent properties. Drilling of CFRP composites is needed for joining of these composite structures. During drilling, delamination is an important factor, which affects the property of the drilled hole. In this work experiments are conducted to analyze the delamination in drilling of CFRP composites. The cutting parameters considered are spindle speed, feed rate, and drill diameter. The tool material used for the present investigation is ‘‘BRAD and SPUR’’ type made of carbide. Second-order mathematical relation is established using response surface methodology for predicting delamination in drilling of CFRP composites. The results indicate that the model can be effectively used to predict the delamination in drilling of CFRP composites. The effect of different parameters in drilling of CFRP composites is analyzed and presented in detail.
Thermal Fatigue Cracking of an IM7/5250-4 Cross Ply Laminate: Experimental and Analytical Observations
Authors: Dalgarno Richard W. , Garnich Mark R. , Andrews Erik W.
Published: August 2009

Coupons of a balanced and symmetric cross ply laminate with polished edges made from IM7/5250-4 were thermally cycled between room and liquid nitrogen temperatures to induce cracks in the matrix. Edge crack densities for each symmetric lamina pair were recorded as a function of the number of cycles. Coupons with an epoxy coating on the polished edges experienced minimal cracking in all interior plies compared to significant cracking for uncoated specimens. This suggests that edge effects play a dominant role in crack initiation. Crack counts were quite different than recorded by another research group for nearly identical tests. Thermal shock was eliminated as a possible significant contributor to the overall physics driving crack formation. Stress analysis was used to support discussions that explain some of the observed trends in crack densities in the various ply pairs. The number of thermal cycles reached 2600 without a clear indication of crack saturation in any of the plies.