bluuebunny/crossref_metadata_2025 huggingface dataset:
AN IMPROVED AREA-COORDINATE BASED QUADRILATERAL SHELL ELEMENT IN DYNAMIC EXPLICIT FEA
Authors: ZHU YAQUN , WU CHONGFENG , ZHU YABO
Published: April 2005

An area-coordinate quadrilateral shell element in dynamic explicit finite element analysis is proposed with a modified interpolation function based on area coordinates, Mindlin shell theory and co-rotational formulations. The element is applied to and verified to have a good performance through comparison with experimental data and results from Belytschko-Tsay element. Computation precision is improved while the efficiency is kept.
ERROR ESTIMATION FOR PRESSURE BROADENING COEFFICIENT FROM FITTING OVERLAPPED SPECTRAL LINE WITH VOIGT PROFILE
Authors: LIN JIE-LI , LU HONG
Published: April 2005

A series of relative errors ε of the pressure broadening coefficient γfit with respect to the real one γ0 from fitting overlapped spectrum which are composed of two lines with the Voigt profile, are deduced and analyzed in detail for different pressure ranges. ε is found to be related with the value of γ0 and the spectral center distance δυ0 of the two component spectral lines which are not resolved. The influence of δυ0, pressures P and γ0 on ε is discussed. This work can be taken as a useful reference for the analysis of the observed spectrum which is overlapped by two lines to achieve more precise results of γfit.
DESIGN AND FABRICATION OF A ONE-DIMENSIONAL SILICON FLOW SENSOR
Authors: GAO DONG-HUI , QIN MING , CHENG HAI-YANG
Published: April 2005

In this paper, the influence of the geometry design on the output of a calorimetric sensor is given. The sensitivity and the range of the flow velocity are two key features for the calorimetric sensor considered here. An optimized geometry of the flow sensor is obtained and a sensor has been fabricated using the optimum geometry. Finally the experimental results are compared to the simulation results and a good agreement between them is achieved where the maximum error in flow velocity measurement is no more than 0.4 m/s.
COMPUTATIONAL VISUAL SENSITIVITY MODELS — A REVIEW
Authors: LU ZHONGKANG , CHI ZHERU
Published: April 2005

The Human Visual Systems (HVSs) is imperfect and contains highly selective visual acquisition sensors. Not all useful information presented to human eyes can be perceived. Generally, a technique to determine whether a signal can be perceived and how well it can be perceived is called human visual sensitivity analysis. More than one hundred years of psychophysical research on HVSs has revealed that human visual sensitivity is not only determined by local characteristics of visual contents (luminance, contrast orientation, spatial and temporal frequency), but also global modulatory factors (visual attention and motion suppression). In this paper, we provide a review on various factors that affect human visual sensitivity and on various computational models for human visual sensitivity. A comparative study on the performance of various visual sensitivity models by simulations is also reported in the paper. Subjective evaluation on noise-embedded video sequences confirms that the introduction of global modulatory factors does improve the performance of the Just Noticeable Difference (JND) profile used in noise shaping.
DEVELOPMENT OF AN EXPLOSIVE DETECTOR WITH A MEMS SENSOR ARRAY
Authors: TAO YONGCHUN , KONG DEYI , MEI TAO , ZHANG TAO , LU WEI , ZHANG DONGFENG
Published: April 2005

An explosive detector based on heat absorption phenomena during melting process of explosives was developed. The detector consisted of an integrated sensor array with heating and detecting elements. The temperature distribution on the array beams was simulated by finite element analysis software, and the array was fabricated by using MEMS technology. By keeping constant temperature of the detecting beam close to the melting points of different explosives and heating the beam with voltage pulses, the array could detect different kinds of trace explosives dynamically. Experiment results indicated that the sensitivity of the sensor array was about 1 μg of cyclotrimethylenetrinitramine (RDX) or trinitrotoluene (TNT) samples.
INTELLIGENT NETWORK COMPUTING AUGMENTED BY CHAOTIC NEURAL NETWORKS, BLIND SOURCES SEPARATION AND DIGITAL WATERMARKS
Authors: SZU HAROLD , HSU CHARLES , HSU MING-KAI , ZHOU JIANTAO , BAO SHUDI
Published: April 2005

A powerful engine of Information Acquisition (IA) that can automatically extract feature and discover knowledge from the real world environment is known as an Intelligent Information Acquisition, IIA. A typical class of such a system is called smart sensor web, e.g. a dynamical smart dust scattering over a field in a self-organization fashion, an electrical powerline serving the volume surveillance in the city public environment where the powerline plug output is the power source required for the operation of the sensors and the input to the powerline is the ecosystem-like communication sparse change signal without the address — a topic of previous paper in this journal. This is possible because IIA of SSW must satisfy 6 W knowing whom, where, when, how, why and what to do. In that sense it will also satisfy the new ad hoc Internet protocol which demands, besides security and authenticity, the privacy protection — a topic of this paper. Such an IIA can serve medical patients, bank customers, or any other Special Interest Groups (SIGs) who must communicate among themselves at the public channel but are not yet ready to share information with the public. Our design might ward off invasive search engine to protect the strict privacy which requires literally no involvement of any third party besides the sender and receiver. Thus, similar to classical postal system, we have adopted envelop wrapper, called digital watermark (DWM), to hide the address of SpatioTemporal Key (STK), so that we do not need to send the high-precision chaos initial value and Chaotic Neural Net (CNN) typing but only the binary "Address Initiation (AI)" listed inside a PC library routine shared by 2N members of SIGs (N>1). The address bits can be redundant in a distributed repetition in order to tolerate any channel noise, package loss, and JPEG-related image compression. Furthermore, the bits are hidden over almost infinitely long lexicographical text pixel sequence of video image frames as digital watermarks. For example, the simplest coded message is the output of "EXOR" operation between the computed STK and originally intended message. Especially, the self-inverse decoding enjoys the projection operator, a cycle two reduction EXOREXOR = I, that means the recovered message comes simply from an identical bits-parallel "EXOR" operation between received coded message and the receiver-on-site-derived STK. Our rigorous definition of privacy enjoys also reasonable security which can be measured in NSA exhausted search sense of a few days up to years of CPU time, and also the cost saving without relying on commercial security RSA codec.
RESEARCH ON MATHEMATICAL THEORY OF INFORMATION ACQUISITION
Authors: WANG XIAO-LONG , GE YUN-JIAN
Published: April 2005

Based on the "otherness" definition, information is assumed to be made up of "dimensions". Consequently, mathematical description of information is realized, and basic operations on information are also realizable. Hence, in IA subspace, information may be valued; the process of IA may be described quantificationally and mathematically. The IAC is brought forward to evaluate the IA process, and the evaluating result is used to ameliorate the IA process.
Exposure to bacterial cell wall products triggers an inflammatory phenotype in hepatic stellate cells
Authors: Brun Paola , Castagliuolo Ignazio , Pinzani Massimo , Palù Giorgio , Martines Diego
Published: April 2005

Activated hepatic stellate cells (HSCs) secrete extracellular matrix components during hepatic fibrosis, but recent studies have shown that HSCs can also release a variety of proinflammatory cytokines. Moreover, bacterial endotoxemia is not only associated with systemic complications in the late stages of liver failure but is also a direct cause of liver damage, activating resident inflammatory cells. In this study, we investigated whether HSCs can respond directly to bacterial cell wall products acquiring a new phenotype. RT-PCR and immunocytochemistry assays were used to show that murine HSCs expressed specific mRNA transcripts and proteins for LPS and lipoteichoic acid (LTA) receptor systems and peptidoglycan recognition proteins. Exposing HSCs to bacterial endotoxins led to phosphorylation of mitogen-activated protein kinase ERK1 and the development of a proinflammatory phenotype. After exposure to LPS, LTA, or N-acetyl muramyl peptide, transforming growth factor-β1, IL-6, and monocyte chemoattractant protein-1 (MCP-1) mRNA specific transcripts and proteins increased significantly in HSCs, as assayed by quantitative real-time RT-PCR and ELISA. These LPS-mediated effects in HSCs were receptor dependent, because LPS-induced ERK1 phosphorylation, IL-6, and MCP-1 mRNA and protein level upregulation were significantly less pronounced in HSCs isolated from C3H/HeJ mice lacking Toll-like receptor 4. In conclusion, our results show that murine HSCs express functional receptors for bacterial endotoxins, and HSCs exposed to bacterial products develop a strong proinflammatory phenotype. We speculate that high levels of bacterial endotoxins in the portal vein may directly induce a proinflammatory phenotype in HSCs that contributes to liver damage.
A novel model of cryoinjury-induced myocardial infarction in the mouse: a comparison with coronary artery ligation
Authors: van den Bos Ewout J. , Mees Barend M. E. , de Waard Monique C. , de Crom Rini , Duncker Dirk J.
Published: April 2005

Mouse myocardial infarction (MI) models are frequently used research tools. The most commonly applied model is coronary artery ligation. However, coronary ligation often gives rise to apical aneurysmatic infarcts of variable size. Other infarct models include cryoinfarction, which produces reproducible infarcts of the anterior wall. Thus far, this model has not been extensively described in mice. Therefore, we developed a murine cryoinfarction model and compared it with coronary ligation. Studies were performed under isoflurane anesthesia with a follow-up of 4 and 8 wk. Cryoinfarction was induced using a 2- or 3-mm cryoprobe. Two-dimensional guided M-mode echocardiography was used to assess fractional shortening and left ventricular (LV) dimensions at baseline and end point. At end point, hemodynamics were assessed using a 1.4-Fr Millar catheter. Pressure-diameter relations were constructed by combining echocardiography and hemodynamic data. Histological and morphometric analyses of infarct and remote areas were performed. At 4 wk, 3-mm cryoinfarction resulted in decreased LV fractional shortening as well as decreased global LV contractility and relaxation, which was comparable with coronary ligation. No adverse remodeling was observed at this time point, in contrast with the ligation model. However, progressive LV remodeling occured between 4 and 8 wk after cryoinfarction with a further decline in hemodynamic parameters and LV pump function. Histologically, cryoinfarction resulted in highly reproducible, transmural, cone-shaped infarcts with reperfusion at the macrovascular level. These results indicate that the cryoinfarction model represents the anterior myocardial infarct with modest adverse remodeling and may thus be representative for infarcts encountered in clinical practice.
Optical measurements reveal nature of intercellular coupling across ventricular wall
Authors: Poelzing Steven , Roth Bradley J. , Rosenbaum David S.
Published: April 2005

Previously, we showed that intercellular uncoupling through gap junctions is an important mechanism for maintaining transmural heterogeneities of repolarization that are responsible for ventricular arrhythmias in disease states such as heart failure. However, rotational anisotropy between transmural muscle layers also may influence coupling. To determine the effect of rotational anisotropy on transmural coupling, we developed a numerical three-dimensional model of passive cardiac tissue in which rotational anisotropy was varied in a controlled fashion. Simulations of optical mapping demonstrated that spatial averaging produced a voltage decay in space best fit by a single decaying exponential compared with the theoretically predicted decay. As fiber orientation varied by 90° with respect to the transmural surface, the effective transmural space constant (λTM) changed by only 0.31% in simulations. In contrast, reducing intercellular conductivity by 24% decreased λTM by 7.7%. In the canine wedge preparation ( n = 5), λ measured by optical mapping of the epicardial and subepicardial surface was similar transverse (λTV = 0.73 ± 0.10 mm) and transmural (λTM = 0.70 ± 0.08 mm) to subepicardial fibers. We confirmed previous findings that λTM in subepicardial layers was significantly reduced by 14 ± 2% compared with deeper layers of myocardium, providing evidence for transmural uncoupling in the epicardial-midmyocardial interface. These data establish the theoretical and experimental basis for measuring intercellular coupling between muscle layers spanning the ventricular wall with optical mapping techniques. Furthermore, this study demonstrates that transmural uncoupling at the epicardial-midmyocardial interface may be attributable to heterogeneous expression of cardiac gap junctions and not rotational anisotropy.
Characterization of tetraethylammonium uptake across the basolateral membrane of theDrosophilaMalpighian (renal) tubule
Authors: Rheault Mark R. , Debicki Donna M. , O'Donnell Michael J.
Published: April 2005

Basolateral transport of the prototypical type I organic cation tetraethylammonium (TEA) by the Malpighian tubules of Drosophila melanogaster was studied using measurements of basolateral membrane potential (Vbl) and uptake of [14C]-labeled TEA. TEA uptake was metabolically dependent and saturable (maximal rate of mediated TEA uptake by all potential transport processes, reflecting the total transport capacity of the membrane, 0.87 pmol·tubule−1·min−1; concentration of TEA at 0.5 of the maximal rate of TEA uptake value, 24 μM). TEA uptake in Malpighian tubules was inhibited by a number of type I (e.g., cimetidine, quinine, and TEA) and type II (e.g., verapamil) organic cations and was dependent on Vbl. TEA uptake was reduced in response to conditions that depolarized Vbl(high-K+saline, Na+-free saline, NaCN) and increased in conditions that hyperpolarized Vbl(low-K+saline). Addition of TEA to the saline bathing Malpighian tubules rapidly depolarized the Vbl, indicating that TEA uptake was electrogenic. Blockade of K+channels with Ba2+did not block effects of TEA on Vblor TEA uptake indicating that TEA uptake does not occur through K+channels. This is the first study to provide physiological evidence for an electrogenic carrier-mediated basolateral organic cation transport mechanism in insect Malpighian tubules. Our results also suggest that the mechanism of basolateral TEA uptake by Malpighian tubules is distinct from that found in vertebrate renal tubules.
Exercise without weight loss is an effective strategy for obesity reduction in obese individuals with and without Type 2 diabetes
Authors: Lee SoJung , Kuk Jennifer L. , Davidson Lance E. , Hudson Robert , Kilpatrick Katherine , Graham Terry E. , Ross Robert
Published: April 2005

It is unclear whether chronic exercise without caloric restriction or weight loss is a useful strategy for obesity reduction in obese men with and without Type 2 diabetes (T2D). We examined the effects of exercise without weight loss on total and regional adiposity and skeletal muscle mass and composition in lean men and in obese men with and without T2D. Twenty-four men participated in 13 wk of supervised aerobic exercise, five times per week for 60 min at a moderate intensity (∼60% peak oxygen uptake). Total and regional body composition was measured by magnetic resonance imaging. Skeletal muscle composition was determined using computed tomography. Cardiorespiratory fitness was assessed using a graded maximal treadmill test. Body weight did not change within any group in response to exercise ( P > 0.1). Significant reductions in total, abdominal subcutaneous, and visceral fat were observed within each group ( P < 0.01). The reduction in total and abdominal subcutaneous fat was not different ( P > 0.1) between groups; however, the reduction in visceral fat was greater ( P < 0.01) in the obese and T2D groups by comparison to the lean group. A significant ( P < 0.01) increase in total skeletal muscle, high-density muscle area, and mean muscle attenuation was observed independent of group, and these changes were not different between groups ( P > 0.1). Accordingly, whole body fat-to-muscle ratio was increased ( P < 0.01) independent of groups. In conclusion, regular exercise without weight loss is associated with a substantial reduction in total and visceral fat and in skeletal muscle lipid in both obesity and T2D.
Cerebral autoregulation is preserved in postural tachycardia syndrome
Authors: Schondorf Ronald , Benoit Julie , Stein Reuben
Published: April 2005

To test whether cerebral autoregulation is impaired in patients with postural tachycardia syndrome (POTS), we evaluated 17 healthy control subjects and 27 patients with POTS. Blood pressure, heart rate, and cerebral blood velocity (transcranial Doppler) were recorded at rest and during 80° head-up tilt (HUT). Static cerebral autoregulation, as assessed from the change in cerebrovascular resistance during HUT, was the same in POTS and in controls. The properties of dynamic cerebral autoregulation were inferred from transfer gain, coherence, and phase of the relationship between blood pressure and cerebral blood velocity estimated from filtered data segments (0.02–0.8 Hz). Dynamic cerebral autoregulation of patients with POTS did not differ from that of controls. The patients' dynamic cerebral autoregulation did not change over the course of HUT, despite increased tachycardia suggestive of worsening orthostatic stress. Inflation of military anti-shock trouser pants substantially reduced the tachycardia of patients with POTS without affecting cerebral autoregulation. Symptoms of orthostatic intolerance were reduced in one-half of the patients following military anti-shock trouser pants inflation. We conclude that cerebral perfusion and autoregulation in many patients with POTS do not differ from that of normal control subjects.
Sex-based differences in skeletal muscle function and morphology with short-term limb immobilization
Authors: Yasuda Nobuo , Glover Elisa I. , Phillips Stuart M. , Isfort Robert J. , Tarnopolsky Mark A.
Published: April 2005

The purpose of this study was to determine the effects of short-term (14-day) unilateral leg immobilization using a simple knee brace (60° flexion)- or crutch-mediated model on muscle function and morphology in men (M, n = 13) and women (W, n = 14). Isometric and isokinetic (concentric-slow, 0.52 rad/s and fast, 5.24 rad/s) knee extensor peak torque was determined at three time points (Pre, Day-2, and Day-14). At the same time points, magnetic resonance imaging was used to measure the cross-sectional area of the quadriceps femoris and dual-energy X-ray absorptiometry scanning was used to calculate leg lean mass. Muscle biopsies were taken from vastus lateralis at Pre and Day-14 for myosin ATPase and myosin heavy chain analysis. Women showed greater decreases (Pre vs. Day-14) compared with men in specific strength (N/cm2) for isometric [M = 3.1 ± 13.3, W = 17.1 ± 15.9%; P = 0.055 (mean ± SD)] and concentric-slow (M = 4.7 ± 11.3, W = 16.6 ± 18.4%; P < 0.05) contractions. There were no immobilization-induced sex-specific differences in the decrease in quadriceps femoris cross-sectional area (M = 5.7 ± 5.0, W = 5.9 ± 5.2%) or leg lean mass (M = 3.7 ± 4.2, W = 2.7 ± 2.8%). There were no fiber-type transformations, and the decreases in type I (M = 4.8 ± 5.0, W = 5.9 ± 3.4%), IIa (M = 7.9 ± 9.9, W = 8.8 ± 8.0%), and IIx (M = 10.7 ± 10.8, W = 10.8 ± 12.1%) fiber areas were similar between sexes. These findings indicate that immobilization-induced loss of knee extensor muscle strength is greater in women compared with men despite a similar extent of atrophy at the myofiber and whole muscle levels after 14 days of unilateral leg immobilization. Furthermore, we have described an effective and safe knee immobilization method that results in reductions in quadriceps muscle strength and size.
Glycogenin activity and mRNA expression in response to volitional exhaustion in human skeletal muscle
Authors: Shearer Jane , Graham Terry E. , Battram Danielle S. , Robinson Deborah L. , Richter Erik A. , Wilson Rhonda J. , Bakovic Marica
Published: April 2005

Glycogenolysis results in the selective catabolism of individual glycogen granules by glycogen phosphorylase. However, once the carbohydrate portion of the granule is metabolized, the fate of glycogenin, the protein primer of granule formation, is not known. To examine this, male subjects ( n = 6) exercised to volitional exhaustion (Exh) on a cycle ergometer at 75% maximal O2uptake. Muscle biopsies were obtained at rest, 30 min, and Exh (99 ± 10 min). At rest, total glycogen concentration was 497 ± 41 and declined to 378 ± 51 mmol glucosyl units/kg dry wt following 30 min of exercise ( P < 0.05). There were no significant changes in proglycogen, macroglycogen, glycogenin activity, or mRNA in this period ( P ≥ 0.05). Exh resulted in decreases in total glycogen, proglycogen, and macroglycogen as well as glycogenin activity ( P < 0.05). These decrements were associated with a 1.9 ± 0.4-fold increase in glycogenin mRNA over resting values ( P < 0.05). Glycogenolysis in the initial exercise period (0–30 min) was not adequate to induce changes in glycogenin; however, later in exercise when concentration and granule number decreased further, decrements in glycogenin activity and increases in glycogenin mRNA were demonstrated. Results show that glycogenin becomes inactivated with glycogen catabolism and that this event coincides with an increase in glycogenin gene expression as exercise and glycogenolysis progress.
Role of arterial hypoxemia and pulmonary mechanics in exercise limitation in adults with cystic fibrosis
Authors: McKone Edward F. , Barry Sinead C. , FitzGerald Muiris X. , Gallagher Charles G.
Published: April 2005

We tested the hypothesis that maximal exercise performance in adults with cystic fibrosis is limited by arterial hypoxemia. In study 1, patients completed two maximal exercise tests, a control and a test with 400 ml of added dead space. Maximal O2 consumption was significantly lower in the added dead space study vs. control (1.04 ± 0.15 vs. 1.20 ± 0.11 l/min; P < 0.05), with no difference in peak ventilation. There was significant O2 desaturation during exercise that was equal in both control and added dead space studies. The decrease in maximal O2 consumption with added dead space suggests that maximal exercise in cystic fibrosis is limited by respiratory factors. We subsequently examined whether pulmonary mechanics or arterial hypoxemia limits maximal exercise performance. In study 2, patients completed two maximal exercise tests, a control and a test with 400 ml of added dead space while also breathing 38% O2. Added dead space was used to overcome the suppressive effects of hyperoxia on minute ventilation. Maximal O2 consumption was significantly higher with added dead space and 38% O2 vs. control (1.62 ± 0.16 vs. 1.43 ± 0.14 l/min; P < 0.05). Peak ventilation and O2 saturation were significantly greater in the added dead space and 38% O2 test vs. control. The increase in maximal O2 consumption and peak ventilation with added dead space and 38% O2 suggests that maximal exercise in cystic fibrosis is limited by arterial hypoxemia.
Overexpression of Protein Kinase Cδ Enhances Cisplatin-Induced Cytotoxicity Correlated with p53 in Gastric Cancer Cell Line
Authors: Iioka Yoshihiko , Mishima Kenji , Azuma Nakanobu , Tsuchida Akihiko , Takagi Yu , Aoki Tatsuya , Saito Ichiro
Published: April 2005

Objective: An important issue in cancer therapy is to investigate the mechanism for cellular sensitivity to anticancer agents such as cisplatin. Cisplatin is one of the DNA-damaging agents and several factors including p53 are related to the sensitivity to cisplatin in cancer. Protein kinase C (PKC) δ is known as a positive regulator for cisplatin-induced cell death. In our present study, we examined whether overexpression of PKCδ and p53 increases the sensitivity of the human gastric cancer cell line, MKN28, which has a mutation of p53 gene, to cisplatin. Methods: Cell viability and DNA content were measured in MKN28 with adenovirus-mediated expression of PKCδ and p53 after exposure to cisplatin. In addition, the active form of caspase-3 was detected by Western blotting. Results: Overexpression of exogenous PKCδ did not induce cell death in MKN28 but inhibited cell growth at 1 µg/ml cisplatin as compared to that by cisplatin alone. Moreover, overexpression of both wild-type p53 and exogenous PKCδ in MKN28 increased cisplatin-induced cell death in MKN28. Conclusion: These results suggest that PKCδ, in cooperation with p53, possibly regulates cisplatin-induced caspase-3-mediated cell death in gastric cancer.
Antifungal Chemotherapeutics
Authors: Krcmery Jr. Vladimir C.
Published: April 2005

This review addresses trends in outcome and risk factors for invasive fungal infections, current antifungal agents and new therapeutic strategies. Current prospects for new therapies rest upon caspofungin, the first of a new class of antifungal molecules, the echinocandins, and new extended-spectrum azoles, voriconazole, posaconazole and ravuconazole. Approval by the Food and Drug Administration of the USA and the European Medicine Agency was given in 2001–2002 to voriconazole and caspofungin. Voriconazole clearly demonstrated a decrease in mortality in invasive aspergillosis and fusariosis fungal infections.
The Prevalence of Atrial Fibrillation among Acute Medical Admissions in Kuwait
Authors: Ridha Mustafa , Al-Sayed Amin Amin , Saleh Salhamoud A. , Cherian Boby , Al-Kandari Fawziah , Redha Faridah , Jamal Khalid , Bitar Zouheir
Published: April 2005

Objective: To establish the prevalence of atrial fibrillation (AF) among acute medical admissions to the Adan Hospital, Kuwait, and to evaluate the clinical features of the patients. Subjects and Methods: Of 2,833 acute medical admissions to the Adan Hospital from January 1 to May 31, 2003, 120 patients with AF were included in the study. The patients were divided into paroxysmal or persistent (PPAF), and chronic atrial fibrillation (CAF). The prevalence of stroke and clinical features of the CAF patients with and without strokes were studied. All the patients with AF underwent echocardiography to evaluate left ventricular ejection fraction (LVEF) and left atrial dimension (LAD). Results: The prevalence of AF in the study period was 4.24%, of which 68.3% had CAF and 31.7% had PPAF. The prevalence of heart failure, ischemic heart disease, systemic hypertension, and diabetes mellitus was 27.5, 55.8, 65.8, and 53.3%, respectively. Patients with CAF were older and had a higher prevalence of heart failure compared to PPAF patients. Of the patients with CAF, 26.8% had at least one episode of stroke. The CAF patients had lower LVEF and larger LAD than PPAF patients. Stroke patients with CAF had lower LVEF and larger LAD as compared to those without stroke. Conclusion: Atrial fibrillation is a common admission diagnosis in our hospital. Patients with AF commonly suffer from heart failure, hypertension, diabetes mellitus, and ischemic heart disease. There was a high prevalence of stroke among CAF patients.
Self-Reported Medication Use among Adolescents in Kuwait
Authors: Abahussain Eman , Matowe Lloyd K. , Nicholls P.J.
Published: April 2005

Objective: The objectives of this study were to describe and examine the pattern of medication use, including age and gender differences among adolescents in Kuwait, and to establish the sources of information on medicines in this age group. Subjects and Methods: A cross-sectional survey of 1,110 male and female students (14–21 years) from 10 randomly selected public schools in Kuwait was conducted.The prevalence of self-medication was estimated.Results: The prevalence of self-medication among the high school students was 92%. The prevalence increased by age from 87% among 14-year-olds to 95% among 18-year-olds. Sixty-five percent of medicines used were for pain relief, 54% for respiratory conditions, 39% for allergic conditions, and 37% for dermatological conditions. Twenty-two percent of medicines were nutritional supplements and vitamins, 21% gastrointestinal products, 17% antidandruff products, 15% hair products, 13% for migraine while 8% were for athlete’s foot. Pain relief, respiratory, dermatologic and hair products were more prevalent in female adolescents than in male while antidandruff and athlete’s foot preparations were used more by male adolescents. The most common sources of information on medicines were parents.Conclusion:The prevalence of self-medication among adolescents in Kuwait is high. Self-medication tended to increase with age and differed between male and female students. Few students consulted pharmacists for information on drugs. There is need to promote the image of the pharmacist in Kuwait as a provider of medication information.
Gelastic Seizures in a Young Boy: Evaluation by Magnetic Resonance Imaging
Authors: Robbani Irfan , Bhat Tariq Ahmed
Published: April 2005

Objective: To present an interesting case of gelastic seizures in a child who had an underlying brain lesion. Clinical Presentation and Intervention: A 10-year-old boy presented with recurrent episodes of uncontrollable laughter since the age of 6 years. Computed tomography showed a well-defined mass in the region of suprasellar and interpeduncular cisterns. Magnetic resonance imaging revealed a lesion, most likely a hamartoma, arising from the region of tuber cinerium. The lesion was subsequently resected and a marked improvement in the frequency and intensity of seizures was noted. Conclusion: This report shows that neuroimaging should be performed on patients with gelastic seizures to exclude any underlying structural lesion of causal significance.
Hodgkin’s Disease and Autoimmune Hemolytic Anemia: A Case Report
Authors: Ozdemir Feyyaz , Yilmaz Mustafa , Akdogan Remzi , Kaynar Kubra , Kavgaci Halil , Karti Sami , Aydin Fazil
Published: April 2005

Objective: To report a case of Hodgkin’s disease presenting with immune hemolytic anemia. Clinical Presentation and Intervention: A 47-year-old man was admitted to hospital because of weight loss, fever, and inguinal lymph node adenopathy. Biopsy of the inguinal lymph node revealed mixed-cellularity Hodgkin’s disease. Three days after starting combined chemotherapy, the patient showed evidence of autoimmune hemolytic anemia, which responded well to prednisolone. Conclusion: This case shows that clinicians should be aware of the possibility of autoimmune hemolytic anemia in patients with Hodgkin’s disease presenting with anemia, and distinguish it from the anemia of chronic disease.
Huge Spindle Cell Hemangioma of the Cervix – Mimicking a Pelvic Tumor
Authors: Wang Yu-Chi , Chen Chi-Huang , Su Her-Young , Li Heng-Sheng , Liu Jah-Yao
Published: April 2005

Background: Spindle cell hemangiomas are rare vascular tumors characterized by cavernous blood vessels and spindled areas reminiscent of Kaposi’s sarcoma. Cervical hemangiomas are rare, and the spindle cell subtype is rarer still. Case: Examination of a 39-year-old patient presenting with pelvic pain revealed a remarkable pelvic mass consisting of a 10-cm tumor extending from the cervix to the retroperitoneum. The pathology report demonstrated spindle cell hemangioma. Conclusion: This is a rare case of spindle cell hemangioma of the cervix resected transvaginally.
Is Steroid Therapy Needed in the Treatment of Destructive Thyrotoxicosis Induced by α-Interferon in Chronic Hepatitis C?
Authors: Minelli Roberta , Valli Maria Antonietta , Di Seclì Clelia , Finardi Lorenzo , Chiodera Paolo , Bertoni Roberto , Ferrari Carlo , Barilli Angela Luciana , Coiro Vittorio , Saccani Jotti Gloria , Delsignore Roberto
Published: April 2005

Objective: Treatment with interferon (IFN) of patients affected by chronic hepatitis C (CH-C) may produce alterations in thyroid function, such as hypothyroidism, Graves’-like hyperthyroidism and destructive thyrotoxicosis (DT). IFN-induced DT is characterized by suppressed serum TSH levels, normal or elevated FT4 and FT3 concentrations, with the presence or absence of thyroid peroxidase antibodies and antithyroglobulin antibodies, the absence of thyroid receptor antibodies and radioactive iodine uptake suppressed or <5%. Design: IFN-induced DT is a mild clinical disease, because thyroid-destructive processes last for a short time and involve a small portion of the gland. At present, the therapeutic approach in DT suggests IFN withdrawal and 1–2 months of methylprednisolone treatment. Methods: In consideration of possible untoward side effects of steroid treatment in patients with CH-C, we studied two groups of patients with CH-C who developed DT after treatments with various preparations of recombinant IFN (with or without ribavirin). Patients sequentially entered the study during a 4-year period, at the time of DT diagnosis, when IFN therapy was discontinued. The first 12 subjects (group A) were treated with 8–16 mg/day methylprednisolone for 30–40 days after IFN withdrawal; in the following 15 patients (group B), IFN withdrawal was not followed by any additional treatment. All patients underwent clinical and laboratory controls of thyroid function at 1, 2, 3 and 6 months after DT diagnosis. Results: The results showed restoration of euthyroidism in both group A and group B patients at 6 months after DT diagnosis, regardless of steroid treatment. Conclusions: The simple withdrawal of IFN therapy in patients with CH-C, who had developed DT, appears to be effective in the treatment of the thyroid disease. This therapeutic approach should be preferred in order to avoid possible undesired side effects of steroid therapy in patients with CH-C.
Adrenocorticotropin/Cortisol and Arginine-Vasopressin Secretory Patterns in Response to Ghrelin in Normal Men
Authors: Coiro Vittorio , Saccani-Jotti Gloria , Minelli Roberta , Melani Andrea , Milli Bruna , Manfredi Guido , Volpi Riccardo , Chiodera Paolo
Published: April 2005

This study was performed in order to establish the secretory patterns and the possible relationships between the adrenocorticotropin (ACTH)/cortisol and arginine vasopressin (AVP) responses in normal men to the systemic administration of ghrelin, an endogenous ligand for the growth hormone secretagogue receptor. For this purpose, a bolus of 1 µg/kg ghrelin was injected intravenously in 9 normal men. AVP, ACTH and cortisol significantly rose in response to ghrelin injection; however, in all subjects the AVP rise preceded the ACTH/cortisol responses. In fact, the mean peak levels of AVP, ACTH and cortisol after ghrelin injection were observed at 15, 30 and 45 min, respectively. When peak AVP responses to ghrelin were considered together with ACTH and cortisol peak levels, highly significant positive correlations were observed (AVP and ACTH, r = 0.94, p < 0.001; AVP and cortisol, r = 0.92, p < 0.001). In conclusion, this study shows that the AVP response to ghrelin precedes the concomitant ACTH/cortisol rise and that these hormonal responses are highly positively correlated. These observations support the hypothesis that AVP mediates ghrelin-induced ACTH secretion in normal men.
Elastic Lamina Defects Are an Early Feature of Aortic Lesions in the Apolipoprotein E Knockout Mouse
Authors: Jones Gregory T. , Jiang Fan , McCormick Sally P.A. , Dusting Gregory J.
Published: April 2005

The aortae from male apolipoprotein E knockout (apoE–/–) mice were examined by serial section immunohistochemistry and electron microscopy to determine the continuity of the internal elastic lamina (IEL) and its association with developing intimal lesions. While in this model, defects in the elastic laminae have previously been described beneath advanced xanthomatous lesions, this study demonstrates that disruption of the IEL may be a primary factor in the localization and pathogenesis of intimal lesions in the apoE–/– mouse. IEL defects were found beneath early lesions in animals as young as 8 weeks of age. Small defects without associated intimal alteration were also observed. The elastic tissue defects beneath early intimal lesions were usually transversely orientated with abrupt ‘break’ edges. Regions consistent with direct enzymatic digestion of the IEL were relatively rare and only observed beneath advanced plaques, particularly in the brachiocephalic artery. The presence of IEL defects around branch sites of old C57BL/6J control mice along with their matching localization and morphology in apoE–/– appears consistent with biomechanical fatigue rather than direct enzymatic degradation. In conclusion, disruption of the IEL appears to be a prominent early, if not initial, feature of the apoE–/– model of atherosclerosis and may act as the nidus upon which intimal lesions develop.
Epidemiology of Multiple Sclerosis in Kuwait: New Trends in Incidence and Prevalence
Authors: Alshubaili A.F. , Alramzy K. , Ayyad Y.M. , Gerish Y.
Published: April 2005

The epidemiology of multiple sclerosis (MS) is undergoing dramatic changes; MS is occurring with increased frequency in many parts of the world. In this retrospective study, we examined the changes in incidence and prevalence of MS in Kuwait in the period between 1993 and 2000. We analyzed the records of patients with clinically defined and laboratory supported MS. The total incidence rate increased from 1.05/100,000 population in 1993 to 2.62/100,000 in 2000. The increased incidence of MS was most pronounced among Kuwaiti women (from 2.26/100,000 in 1993 to 7.79/100,000 in 2000. The total prevalence rate increased from 6.68/100,000 in 1993 to 14.77/100,000 in 2000. It was much higher for Kuwaitis (31.15/100,000), as compared to non-Kuwaitis (5.55/ 100,000), in a complete reversal of the pattern observed before 1990. The prevalence was also higher among Kuwaiti women (35.54/100,000), as compared with Kuwaiti men (26.65/100,000). In conclusion, the incidence and prevalence of MS in Kuwait has increased between the early and late 1990s with no signs of leveling off. In a geographic area that was previously associated with low prevalence, local environmental factors may be responsible for these dramatic changes.
Cerebral Infarcts Complicating Tuberculous Meningitis
Authors: Chan K.H. , Cheung R.T.F. , Lee R. , Mak W. , Ho S.L.
Published: April 2005

Cerebral infarction (CI) is a serious complication of tuberculous meningitis (TBM). It can be asymptomatic or symptomatic, causing stroke. We studied 40 TBM patients. All had initial CT brain scan, CT/MRI brain scan 3 months later and urgent CT brain scan for deterioration. CI was classified into lacunar infarction (LI) or large artery infarction (LAI). Twelve (30%) had CI, in 9 (23%) it was symptomatic and in 3 (8%) silent. Seven (58%) had LAI ± LI. Eight (67%) had multiple CI. Two died from brainstem CI and 6 were dependent at 1 year. Patients with LAI might develop posterior circulation CI more frequently than those with LI only. CI is a common complication of TBM locally, with LAI and multiple CI being common. Two thirds of TBM patients complicated by CI had poor prognosis despite adjunctive dexamethasone treatment.
Statins Decrease Toll-Like Receptor 4 Expression and Downstream Signaling in Human CD14
+
Monocytes
Authors: Methe Heiko , Kim Jong-Oh , Kofler Sieglinde , Nabauer Michael , Weis Michael
Published: April 2005

Objective—

Anti-inflammatory effects of statins contribute to their clinical benefit. Molecular mechanisms underlying these effects have not been well explored. Because statins attenuate lipopolysaccharide (LPS) responsiveness, we hypothesized that part of the pleiotropic effects are mediated through innate immunity.

Methods and Results—

Toll-like receptor (TLR) 4 expression and downstream signaling in CD14
+
monocytes after incubation with simvastatin and atorvastatin were quantified via flow-cytometry, quantitative RT-PCR, kinase assay, and enzyme-linked immunosorbent assay. Incubation with intermediates/ inhibitors of the mevalonate pathway was used to identify the mode of statin action. Statin incubation resulted in a dose-dependent reduction of TLR4 expression (53±7.6% reduction compared with untreated monocytes;
P
<0.005), transcript levels (68±6.3%;
P
<0.002), decreased IRAK phosphorylation (37±8.3%;
P
<0.05), and LPS-induced IL-6, IL-12, tumor necrosis factor (TNF)-α, and B7-1 expression (
P
<0.05). Four weeks of treatment with atorvastatin significantly reduced TLR4 expression on circulating CD14
+
monocytes by 36.2±4.2% (
P
<0.05). Effects of statins were reversed by mevalonate (
P
=0.57). Incubation with specific inhibitors of geranylgeranyltransferase (54±4.3%), farnesyltransferase (57±5.1%), or with clostridium-difficile toxin B (58±6.1%,
P
<0.01) imitated the statin effects. Whereas wortmannin and LY294002 inhibited the statin effect (
P
=0.27), incubation with a specific RhoA kinase inhibitor had no effect (
P
=0.57).

Conclusions—

Statins influence TLR4 expression and signaling via inhibition of protein geranylgeranylation and farnesylation. These observations imply interactions with innate immunity as one pleiotropic mechanism.
Elastin-Derived Peptides Induce a T-Helper Type 1 Polarization of Human Blood Lymphocytes
Authors: Debret Romain , Antonicelli Frank , Theill Aurore , Hornebeck William , Bernard Philippe , Guenounou Moncef , Le Naour Richard
Published: April 2005

Objective—Increased level of elastin-derived peptides (EDPs) is observed in the serum of patients with manifestations of arterial diseases. We here investigated whether EDPs might exert, at systemic level, a regulatory role for the T-helper type 1 (Th-1)/Th-2 cellular immune response by human peripheral blood lymphocytes (PBLs) expressing the spliced-galactosidase (S-gal)–elastin receptor.

Methods and Results—Using flow cytometry and Western blot analysis, we demonstrated that EDPs led to an activation of the S-gal-elastin receptor associated with cytokine production on PBLs and CD4+T cell subpopulations. The constitutive expression of the S-gal–elastin receptor at the surface of human PBLs was upregulated at the mRNA (RT-PCR) and protein (ELISA) levels on cell activation. In nonactivated and phytohemagglutinin-activated conditions, expressions of the predominant Th-2 cytokine interleukin-5 (IL-5) and IL-10 were reduced, whereas those of the major Th-1 cytokines interferon-γ and IL-2 were enhanced by EDPs. Furthermore, we evidenced that EDPs could not only potentiate the IL-12–induced Th-1 profile but also could reverse the Th-2 (over Th-1) profile induced by IL-4. Finally, Th-1 cytokine upregulation was associated to an increased activator protein-1 DNA binding and enhanced pro–matrix metalloproteinase-9 secretion.

Conclusions—This study highlights the importance of EDPs as stimuli for Th-1 differentiation, whether T cells are in an inactivated state or already orientated toward a Th-1 (IL-12) or Th-2 (IL-4) response.
Intracellular and Surface Distribution of Monocyte Tissue Factor
Authors: Egorina Elena M. , Sovershaev Mikhail A. , Bjørkøy Geir , Gruber Franz X.E. , Olsen Jan O. , Parhami-Seren Behnaz , Mann Kenneth G. , Østerud Bjarne
Published: April 2005

Objective—The high and low responder phenomenon describes individual differences in lipopolysaccharide (LPS)-induced monocyte tissue factor (TF) activity. We characterized patterns of intracellular accumulation, externalization, and shedding of TF in response to LPS in mononuclear cells (MNCs) from high responders (HRs) and low responders (LRs).

Methods and Results—After 2 hours of LPS stimulation of whole blood, flow cytometry analyses revealed a larger population of TF-positive monocytes in HRs (32.0±3.5%) versus LRs (11.2±1.2%;P≤0.05), along with a stronger mean fluorescence intensity of TF signal in HRs (7.1±0.5 arbitrary units [AU]) compared with LRs (5.4±0.4 AU;P≤0.05). The LPS-treated blood of the HR group contained 2-fold more TF-positive microparticles than LRs. In-cell Western assay demonstrated higher intracellular accumulation of TF in mononuclear cells (MNCs) from LRs because LPS induced a 3.7-fold increase of total TF levels in LRs versus a 1.5-fold increase in HRs. In contrast, in response to LPS stimulation, MNCs from HRs exhibited a 4-fold induction of surface TF, whereas MNCs from LRs only had a minor increase in surface TF levels.

Conclusions—The higher availability of surface TF antigen on MNCs from HRs and TF-containing microparticles might make these individuals more susceptible to hypercoagulation.
Asymmetrical Dimethylarginine in Idiopathic Pulmonary Arterial Hypertension
Authors: Kielstein Jan T. , Bode-Böger Stefanie M. , Hesse Gerrit , Martens-Lobenhoffer Jens , Takacs Attila , Fliser Danilo , Hoeper Marius M.
Published: April 2005

Objective—

We explored the potential role of the endogenous NO synthase inhibitor asymmetrical dimethylarginine (ADMA) in patients with idiopathic pulmonary arterial hypertension (IPAH).

Method and Results—

We correlated plasma ADMA levels and cardiovascular indices from right heart catheterization in 57 patients with IPAH. Predictors of survival in patients with IPAH were studied. Furthermore, the effect of systemic ADMA infusion on pulmonary ventricular resistance and stroke volume was investigated in healthy volunteers using right heart catheterization. Mean plasma ADMA concentrations were significantly higher in patients with IPAH than in control subjects (0.53±0.15 versus 0.36±0.05 μmol/L;
P
<0.001). ADMA plasma concentrations correlated significantly with indices of right ventricular function, such as mixed-venous oxygen saturation (
r
=−0.49;
P
<0.0001), right atrial pressure (
r
=0.39;
P
<0.003), cardiac index (
r
=−0.35;
P
<0.008), as well as survival (
r
=−0.47;
P
<0.0001). Multiple regression analysis revealed that right atrial pressure (
r
=0.31;
P
<0.026) and ADMA (
r
=0.29;
P
<0.039) were independent predictors of mortality. Moreover, patients with supra-median plasma ADMA levels had significantly (
P
<0.021) worse survival than patients with infra-median ADMA values. ADMA infusion in healthy volunteers increased pulmonary vascular resistance (68.9±7.6 versus 95.6±6.3 dyne · s · cm
−5
;
P
<0.05) and decreased stroke volume (101.1±6.7 mL versus 95.6±6.3 mL;
P
<0.05).

Conclusion—

Increased ADMA plasma levels are associated with unfavorable pulmonary hemodynamics and worse outcome in patients with IPAH.
Associations of Serum IL-18 Levels With Carotid Intima-Media Thickness
Authors: Yamagami Hiroshi , Kitagawa Kazuo , Hoshi Taku , Furukado Shigetaka , Hougaku Hidetaka , Nagai Yoji , Hori Masatsugu
Published: April 2005

Objective—

Elevated circulating levels of IL-18 can predict future coronary heart disease. Although IL-18 is thought to play a crucial role in atherosclerosis, whether circulating IL-18 levels are associated with the severity of atherosclerosis remains to be determined. With the use of B-mode ultrasound, this study examines the relationships of serum IL-18 levels with carotid intima-media thickness (IMT) as a reflector for systemic atherosclerosis.

Methods and Results—

The study comprised 366 patients without histories of cardiovascular accidents. Severity of carotid atherosclerosis was evaluated by the mean max IMT, ie, mean of the maximal wall thickness at 12 carotid segments. Serum IL-18, IL-6, and high-sensitive C-reactive protein (hs-CRP) levels were determined in all patients. Log-transformed IL-18 concentrations were positively correlated with IMT (
r
=0.36,
P
<0.001), and the association remained significant (β=0.20,
P
<0.001) when controlling for traditional atherosclerotic risk factors, IL-6 and hs-CRP levels. Also, IMT was greater in the highest and the middle tertile of IL-18 levels than in the lowest tertile.

Conclusion—

Higher serum IL-18 levels appear to be associated with greater carotid IMT, suggesting the link between IL-18 and atherosclerosis.