bluuebunny/crossref_metadata_2025 huggingface dataset:
A perturbation approach to acoustic scattering in dispersions
Authors: Pinfield Valerie J. , Povey Malcolm J. W.
Published: August 2006

Ultrasound spectroscopy has many applications in characterizing dispersions, emulsions, gels, and biomolecules. Interpreting measurements of sound speed and attenuation relies on a theoretical understanding of the relationship between system properties and their effect on sound waves. At its basis is the scattering of a sound wave by a single particle in a suspending medium. The problem has a well-established solution derived by expressing incident and scattered fields in terms of Rayleigh expansions. However, the solution is badly conditioned numerically. By definition, in the long-wavelength limit, the wavelength is much larger than the particle radius, and the scattered fields can then be expressed as perturbation series in the parameter Ka (wave number multiplied by particle radius), which is small in this limit. In addition, spherical Bessel and Hankel functions are avoided by using alternative series expansions. In a previous development of this perturbation method, thermal effects had been considered but viscous effects were excluded for simplicity. Here, viscous effects, giving rise to scattered shear waves, are included in the formulation. Accurate numerical correspondence is demonstrated with the established Rayleigh series method for an emulsion. This solution offers a practical computational approach to scattering which can be embodied in acoustic instrumentation.
Human IRGM Induces Autophagy to Eliminate Intracellular Mycobacteria
Authors: Singh Sudha B. , Davis Alexander S. , Taylor Gregory A. , Deretic Vojo
Published: August 2006

Immunity-related p47 guanosine triphosphatases (IRG) play a role in defense against intracellular pathogens. We found that the murine Irgm1 (LRG-47) guanosine triphosphatase induced autophagy and generated large autolysosomal organelles as a mechanism for the elimination of intracellular
Mycobacterium tuberculosis
. We also identified a function for a human IRG protein in the control of intracellular pathogens and report that the human Irgm1 ortholog, IRGM, plays a role in autophagy and in the reduction of intracellular bacillary load.
SAT-BASED MODEL CHECKING FOR REGION AUTOMATA
Authors: YU FANG , WANG BOW-YAW
Published: August 2006

We propose a new SAT-based model checking algorithm to solve the reachability problem of real-time systems. In our algorithm, the behavior of region automata is encoded as Boolean formulas, and hence any SAT solver can be used to explore the region graph efficiently. Although our SAT-based algorithm performs better than other algorithms in flaw detection, it is less effective in proving properties. To overcome the problem, we incorporate a complete inductive method in our algorithm to improve the performance when the property is satisfied. We implement both algorithms in a tool called xBMC and report experimental results. The experiments show that the combination of efficient encoding and inductive methods offers an effective and practical method for the analysis of timing behavior.
EXPLOITING SYMMETRIES FOR TESTING EQUIVALENCE VERIFICATION IN THE SPI CALCULUS
Authors: BERTOLOTTI IVAN CIBRARIO , DURANTE LUCA , SISTO RICCARDO , VALENZANO ADRIANO
Published: August 2006

Testing equivalence is a quite powerful way of expressing security properties of cryptographic protocols, but its formal verification is a difficult task, because it is based on universal quantification over contexts. A technique based on state exploration to address this verification problem has previously been presented; it relies on an environment-sensitive labelled transition system (ES-LTS) and on symbolic term representation. This paper shows that such a technique can be enhanced by exploiting symmetries found in the ES-LTS structure. Experimental results show that the proposed enhancement can substantially reduce the size of the ES-LTS and that the technique as a whole compares favorably with respect to related work.
BÜCHI COMPLEMENTATION MADE TIGHTER
Authors: FRIEDGUT EHUD , KUPFERMAN ORNA , VARDI MOSHE Y.
Published: August 2006

The complementation problem for nondeterministic word automata has numerous applications in formal verification. In particular, the language-containment problem, to which many verification problems is reduced, involves complementation. For automata on finite words, which correspond to safety properties, complementation involves determinization. The 2n blow-up that is caused by the subset construction is justified by a tight lower bound. For Büchi automata on infinite words, which are required for the modeling of liveness properties, optimal complementation constructions are quite complicated, as the subset construction is not sufficient. From a theoretical point of view, the problem is considered solved since 1988, when Safra came up with a determinization construction for Büchi automata, leading to a 2O(n log n) complementation construction, and Michel came up with a matching lower bound. A careful analysis, however, of the exact blow-up in Safra's and Michel's bounds reveals an exponential gap in the constants hiding in the O( ) notations: while the upper bound on the number of states in Safra's complementary automaton is n2n, Michel's lower bound involves only an n! blow up, which is roughly (n/e)n. The exponential gap exists also in more recent complementation constructions. In particular, the upper bound on the number of states in the complementation construction of Kupferman and Vardi, which avoids determinization, is (6n)n. This is in contrast with the case of automata on finite words, where the upper and lower bounds coincides. In this work we describe an improved complementation construction for nondeterministic Büchi automata and analyze its complexity. We show that the new construction results in an automaton with at most (0.96n)n states. While this leaves the problem about the exact blow up open, the gap is now exponentially smaller. From a practical point of view, our solution enjoys the simplicity of the construction of Kupferman and Vardi, and results in much smaller automata.
ALGORITHMS FOR POINT SET MATCHING WITH k-DIFFERENCES
Authors: AKUTSU TATSUYA
Published: August 2006

The largest common point set problem (LCP) is, given two point set P and Q in d-dimensional Euclidean space, to find a subset of P with the maximum cardinality that is congruent to some subset of Q. We consider a special case of LCP in which the size of the largest common point set is at least (|P| + |Q| - k)/2. We develop efficient algorithms for this special case of LCP and a related problem. In particular, we present an O(k3n1.34 + kn2 log n) time algorithm for LCP in two-dimensions, which is much better for small k than an existing O(n3.2 log n) time algorithm, where n = max {|P|,|Q|}.
SORTING SIGNED PERMUTATIONS BY FIXED-LENGTH REVERSALS
Authors: QI XINGQIN , LI GUOJUN , WU JICHANG , LIU BINGQIANG
Published: August 2006

A signed n-permutation is a permutation on {1,2,…,n} in which each element is labelled by a positive or negative sign. Here we consider the problem of sorting signed permutations by fixed-length reversals. Indeed, limiting the transformations to reversals of length exactly k can be very restrictive, for example, (+1,+3,+2,+4,…,+n) can never be sorted to (+1,+2,+3,+4,…,+n) by 2-reversals. That is, for given two signed permutations it is not obvious whether they can be sorted to each other by k-reversals. Thus in 1996, Chen and Skiena gave the following open problem: what is the connectedness of signed permutations under fixed-length reversals? In this paper, we resolve this open problem when "fixed-length" is even, and give a characterization of the connectedness of signed n-permutations under 2l-reversal, for both linear and circular permutations.
COVERING OF TRANSIENT SIMULATION OF FEEDBACK-FREE CIRCUITS BY BINARY ANALYSIS
Authors: YE YULI , BRZOZOWSKI JANUSZ
Published: August 2006

Transient simulation of a gate circuit is an efficient method of counting signal changes occurring during a transition of the circuit. It is known that this simulation covers the results of classical binary analysis, in the sense that all signal changes appearing in binary analysis are also predicted by the simulation. For feedback-free circuits of 1- and 2-input gates, it had been shown that the converse also holds, if wire delays are taken into account. In this paper we generalize this result. First, we prove that, for any feedback-free circuit N of arbitrary gates, there exists an expanded circuit[Formula: see text], constructed by adding a number of delays to each wire of N, such that binary analysis of [Formula: see text] covers transient simulation of N. For this result, the number of delays added to a wire is obtained from the transient simulation. Our second result involves adding only one delay per wire, which leads to the singular circuit[Formula: see text] of N. This result is restricted to circuits consisting only of gates realizing functions from the set [Formula: see text], functions obtained by complementing any number of inputs and/or the output of a function from [Formula: see text], and FORKS. The numbers of inputs of the AND, OR and XOR gates are arbitrary, and all functions of two variables are included. We show that binary analysis of such a circuit [Formula: see text] covers transient simulation of N. We also show that this result cannot be extended to arbitrary gates, if we allow only a constant number of delays per wire.
A DOORWAY TO BORROMEAN HALO NUCLEI: THE SAMBA CONFIGURATION
Authors: YAMASHITA M. T. , FREDERICO T. , HUSSEIN M. H.
Published: August 2006

We exploit the possibility of new configurations in three-body halo nuclei, Samba type (the neutron-core form a bound system) as a doorway to Borromean systems. The nuclei 12 Be , 15 B , 23 N and 27 F are of such nature, in particular 23 N with a half-life of 37.7 s and a halo radius of 6.07 fm is an excellent example of Samba-halo configuration. The fusion below the barrier of the Samba halo nuclei with heavy targets could reveal the so far elusive enhancement and a dominance of one-neutron over two-neutron transfers, in contrast to what was found recently for the Borromean halo nucleus 6 He +238 U .
PROPOSAL FOR DIRECT SEARCH FOR STRONGLY BOUND STATES OF $p\bar p$, $n\bar p$ SYSTEMS WITH HIGH INTENSITY AND COLLECTIVE $\bar p$ BEAM
Authors: LI HAI-BO , YANG MAO-ZHI , YUAN CHANG-ZHENG
Published: August 2006

Here, we discuss the possibility of showing the existence of [Formula: see text] and [Formula: see text] bound states. Measurement of the single γ-ray from [Formula: see text] and [Formula: see text] systems at rest can directly confirm whether X(1860) and X(1835) are the resonances which are strongly coupled to [Formula: see text]. In addition to the neutral candidate, a charged resonance X- is also proposed to be searched for in [Formula: see text] channel. We find that the data from the Crystal Barrel experiment at LEAR/CERN can be used to confirm the X(1835) observed by BES collaboration. The possibility of measuring the γ spectrum below 100 MeV at the new experiment with cold high intensity [Formula: see text] beam at GSI is discussed. These new techniques can be used to probe the structure of the X(1860) and X(1835) in the future.
EXACT RESULTS FOR MANY-BODY PROBLEMS USING FEW-BODY METHODS
Authors: CARDY JOHN
Published: August 2006

Recently there has been developed a new approach to the study of critical quantum systems in 1+1 dimensions which reduces them to problems in one-dimensional Brownian motion. This goes under the name of stochastic, or Schramm, Loewner Evolution (SLE). I review some of the recent progress in this area, from the point of view of many-body theory. Connections to random matrices also emerge.
MONOLAYER CHARGED QUANTUM FILMS: A QUANTUM SIMULATION STUDY
Authors: WIERSCHEM KEOLA , MANOUSAKIS EFSTRATIOS
Published: August 2006

We use path-integral Monte Carlo (PIMC) to study the effects of adding a long-range repulsive Coulomb interaction to the usual Van der Waals interaction between two atoms of a submonolayer quantum film such as helium on graphite or a pure two-dimensional superfluid. Such interactions frustrate or compete with the natural tendency of the system for phase separation namely to form a macroscopic liquid or solid phase. We find that as a function of the relative strength of the long-range repulsion, surface coverage and temperature, the system undergoes a series of transformations, including a triangular Wigner-like crystal of clusters, a charge stripe-ordered phase and a fluid phase. The goal of these studies is to understand the role of quantum fluctuations when such competing interactions appear together with formation of preexisting electron pairs as might be the case in cuprate superconductors.
NEW APPROACHES TO STRONG COUPLING LATTICE QCD
Authors: CHANRASEKHARAN SHAILESH
Published: August 2006

Efficient cluster algorithms have recently been discovered to solve strong coupling lattice QCD with staggered fermions in the chiral limit from first principles. This allows us for the first time to uncover the universal properties close to chiral phase transitions and make connections with chiral perturbation theory. In this article we will review some of the recent progress and outline some possible directions for future work.
SUPERFLUID REGIMES IN DEGENERATE ATOMIC FERMI GASES
Authors: SHLYAPNIKOV G. V.
Published: August 2006

We give a brief overview of recent studies of quantum degenerate regimes in ultracold Fermi gases. The attention is focused on the regime of Bose-Einstein condensation of weakly bound molecules of fermionic atoms, formed at a large positive scattering length for the interspecies atom-atom interaction. We analyze remarkable collisional stability of these molecules and draw prospects for future studies.
BOSONS IN OPTICAL LATTICES
Authors: ROLSTON S. L.
Published: August 2006

The advent of coherent matter waves in the form of Bose-Einstein condensates, coupled with periodic potentials in the form of optical lattices, has established a new area of research on the boundary between atomic and condensed matter physics. This article is a brief review of the recent experimental progress in the area of degenerate Bose gases loaded into optical lattices, including strongly correlated systems and the role of dimensionality. Future prospects will also be outlined.
GENERALIZED ENTANGLEMENT AND QUANTUM PHASE TRANSITIONS
Authors: SOMMA ROLANDO , BARNUM HOWARD , KNILL EMANUEL , ORTIZ GERARDO , VIOLA LORENZO
Published: August 2006

Quantum phase transitions in matter are characterized by qualitative changes in some correlation functions of the system, which are ultimately related to entanglement. In this work, we study the second-order quantum phase transitions present in models of relevance to condensed-matter physics by exploiting the notion of generalized entanglement [Barnum et al., Phys. Rev. A 68, 032308 (2003)]. In particular, we focus on the illustrative case of a one-dimensional spin-1/2 Ising model in the presence of a transverse magnetic field. Our approach leads to tools useful for distinguishing between the ordered and disordered phases in the case of broken-symmetry quantum phase transitions. Possible extensions to the study of other kinds of phase transitions as well as of the relationship between generalized entanglement and computational efficiency are also discussed.
ON COHEN'S CLASSICAL TELEPORTATION OF CLASSICAL STATES
Authors: HRASKÓ P.
Published: August 2006

We present additional considerations to elucidate the nature of Cohen's classical teleportation of classical bits.
Isolation and characterization of cholangiocyte primary cilia
Authors: Huang Bing Q. , Masyuk Tatyana V. , Muff Melissa A. , Tietz Pamela S. , Masyuk Anatoliy I. , LaRusso Nicholas F.
Published: August 2006

Primary cilia are distinct organelles expressed by many vertebrate cells, including cholangiocytes; however, their functions remain obscure. To begin to explore the physiological role of these organelles in the liver, we described the morphology and structure of cholangiocyte cilia and developed new approaches for their isolation. Primary cilia were present only in bile ducts and were not observed in hepatocytes or in hepatic arterial or portal venous endothelial cells. Each cholangiocyte possesses a single cilium that extends from the apical membrane into the bile duct lumen. In addition, the length of the cilia was proportional to the bile duct diameter. We reproducibly isolated enriched fractions of cilia from normal rat and mouse cholangiocytes by two different approaches as assessed by scanning electron, transmission electron, and confocal microscopy. The purity of isolated ciliary fractions was further analyzed by Western blot analysis using acetylated tubulin as a ciliary marker and P2Y2 as a nonciliary cell membrane marker. These novel techniques produced enriched ciliary fractions of sufficient purity and quantity for light and electron microscopy and for biochemical analyses. They will permit further assessment of the role of primary cilia in normal and pathological conditions.
Hypertension and impaired vascular function in a female mouse model of systemic lupus erythematosus
Authors: Ryan Michael J. , McLemore Gerald R.
Published: August 2006

Systemic lupus erythematosus (SLE) is a chronic autoimmune inflammatory disease that predominantly affects women during their reproductive years. Although women with SLE have hypertension, the underlying mechanisms for this have not been examined. Despite the fact that inflammation is associated with altered endothelial and vascular function, the role of altered vascular function in the development of hypertension during SLE is unclear. In the present study, we tested whether a mouse model of SLE (NZBWF1) develops hypertension and examined whether increased blood pressure was associated with impaired endothelial-dependent relaxation. Female NZBWF1 mice were studied at 8, 20, and 36 wk of age. By 36 wk, urinary albumin and antinuclear antibodies were increased in SLE compared with control mice. Mean arterial pressure, measured by radiotelemetry, was significantly increased in SLE mice (124 ± 4 mmHg, n = 10) compared with control NZW/LacJ mice (111 ± 3 mmHg, n = 7) at 36 wk. Isolated carotid arteries from NZBWF1 mice, precontracted with U-46619 for assessment of endothelial-dependent relaxation, demonstrated a progressively impaired relaxation to ACh with age, although endothelial nitric oxide synthase mRNA expression was not different. Maximal tension generated by 5-hydroxytryptamine was increased in carotid arteries from NZBWF1 mice compared with controls at 8, 20, and 36 wk of age, suggesting a role for altered vascular function early on in the progression of SLE. Taken together, our data support a role for altered endothelial function as a contributing factor to the development of hypertension during SLE.
Responses of thoracic spinal neurons to activation and desensitization of cardiac TRPV1-containing afferents in rats
Authors: Qin Chao , Farber Jay P. , Miller Kenneth E. , Foreman Robert D.
Published: August 2006

The purpose of this study was to examine how upper thoracic spinal neurons responded to activation and desensitization of cardiac transient receptor potential vanilloid-1 (TRPV1)-containing afferent fibers. Extracellular potentials of single T3 spinal neurons were recorded in pentobarbital-anesthetized, paralyzed, and ventilated male rats. To activate cardiac nociceptive receptors, a catheter was placed in the pericardial sac to administer various chemicals: bradykinin (BK; 10 μg/ml, 0.2 ml), capsaicin (CAP, 10 μg/ml, 0.2 ml), or a mixture of algesic chemicals (AC; 0.2 ml) containing adenosine 10−3 M, BK, serotonin, histamine, and PGE2, 10−5 M for each. Spinal neurons that responded to intrapericardial BK and/or CAP were used in this study. Results showed that 81% (35/43) of the neurons had excitatory responses to both intrapericardial BK and CAP, and the remainder responded to either BK or CAP. Intrapericardial resiniferatoxin (RTX) (0.2 μg/ml, 0.2 ml, 1 min), which desensitizes TRPV1-containing nerve endings, abolished excitatory responses to both BK ( n = 8) and CAP ( n = 7), and to AC ( n = 5) but not to somatic stimuli. Intrapericardial capsazepine (1 mg/ml, 0.2 ml, 3 min), a specific antagonist of TRPV1, sharply attenuated excitatory responses to CAP in 5/5 neurons, but responses to BK in 5/5 neurons was maintained. Additionally, intrapericardial capsazepine had no significant effect on excitatory responses to AC in 3/3 neurons. These data indicated that intrapericardial BK-initiated spinal neuronal responses were linked to cardiac TRPV1-containing afferent fibers, but were not dependent on TRPV1. Intraspinal signaling for cardiac nociception was mediated through CAP-sensitive afferent fibers innervating the heart.
NM23-H2, an estrogen receptor β-associated protein, shows diminished expression with progression of atherosclerosis
Authors: Rayner Katey , Chen Yong-Xiang , Hibbert Benjamin , White Dawn , Miller Harvey , Postel Edith H. , O'Brien Edward R.
Published: August 2006

While estrogen receptor (ER) profile plays an important role in response to estrogens, receptor coregulators act as critical determinants of signaling. Although the clinical effects of ovarian hormones on various normal and pathological processes are an active area of research, the exact signaling effects on, for example, the vessel wall, are incompletely understood. Hence, we sought to discover proteins that associate with ERβ, the isoform that shows upregulated mRNA expression after arterial injury. Using a yeast two-hybrid screen we identified NM23-H2, a multifaceted metastasis suppressor candidate protein, as an ERβ-associated protein. Although NM23-H2 was immunodetected in arteries from young subjects (27 ± 6 yr, 14 men and 6 women) with benign intimal hyperplasia, expression was diminished in fatty streaks/atheromas and altogether absent in advanced atherosclerotic lesions. Both nm23-H2 mRNA and protein were expressed by vascular cells in vitro. Treatment with 17β-estradiol and an ERβ-selective agonist, diarylpropionitrile, increased protein expression of NM23-H2; an effect that was not seen with an ERα-selective agonist, propylpyrazole-triol. Estrogen also prompted nuclear localization of NM23-H2 protein in human coronary smooth muscle cells (SMCs). An in vitro mimic of inflammation decreased the expression of NM23-H2 in SMCs, which was restored on addition of estrogen and dependent on the estrogen receptor. In summary, we report the novel association of NM23-H2 with ERβ and show for the first time its expression in vascular cells and demonstrate regulation of its expression and localization by estrogen. In that the abundance of NM23-H2 diminishes with both the advancement of atherosclerosis and inflammation, this ERβ-associated protein may play an important role in mediating the vasculoprotective effects of estrogens.
Homer Wheelon, M.D., physiologist, artist, and poet: origins of the tailpieces in journals of the American Physiological Society
Authors: Schramm Lawrence P. , Schramm Diana C. , Jackson F. Wilson
Published: August 2006

Since 1953, illustrations have been inserted as “tailpieces” at the ends of articles in The American Journal of Physiology and The Journal of Applied Physiology. The drawings were made by Homer Wheelon, a member of the American Physiological Society from 1919 until his death in 1960. Forty-five years after his death, Wheelon is unknown, but he contributed 32 publications to the medical literature and trained J. Earl Thomas, an important 20th century gastrointestinal physiologist. Wheelon was born into poverty in 1883 to itinerant Methodist preachers, circumstances that guided his education and career choices. Throughout his life, Wheelon exhibited a fondness and talent for art and photography and an unusual breadth of intellectual interests and knowledge. Wheelon received a bachelor’s degree from the University of Washington, then studied at the University of Oregon, Northwestern University, and St. Louis University. Earning his M.D. from St. Louis University and assuming a faculty position there, Wheelon and his graduate student, Thomas, conducted widely recognized gastrointestinal research. Returning to Seattle in 1921, Wheelon became a highly respected physician and hospital administrator, but he also found time to indulge his interest in visual art and poetry. In 1933, inspired by observing a rabbit being used in a pregnancy test, Wheelon began to write and illustrate an epic, 322-page poem, Rabbit No. 202, illustrations from which became the journals’ tailpieces. The present study traces Wheelon’s personal life and scientific career in an attempt to understand this complex man and the origins of his unusual poem and its drawings.
Modified Extravesical Ureteroneocystostomy for Completely Duplicated Ureters in Renal Transplantation
Authors: Uchida Junji , Naganuma Toshihide , Machida Yuichi , Kitamoto Koichiro , Yamazaki Takeshi , Iwai Tomoaki , Nakatani Tatsuya
Published: August 2006

Introduction: Completely duplicated ureters are the most common congenital malformation of the upper urinary tract. However, there are very few reports on transplantation using kidneys with double ureters, and the technique of ureterocystoneostomy for completely duplicated ureters has not yet been established. Patients and Methods: We treated 3 patients with completely duplicated ureters at our institutions from January 1998 to October 2005. We modified the extravesical technique for treating these 3 cases and evaluated the 52-month follow-up period for possible urological complications. Results: Neither urological complications nor urinary tract infections occurred in the follow-up period after using our new technique. Conclusion: We conclude that this technique is an appropriate procedure for the transplantation of kidneys with completely duplicated ureters.
CD10 Expression in Urothelial Bladder Carcinomas: A Pilot Study
Authors: Bircan Sema , Candir Ozden , Kapucuoglu Nilgun , Serel T. Ahmet , Ciris Metin , Karahan Nermin
Published: August 2006

Objectives: The aims of this study were to investigate the expression of CD10 in normal bladder tissue and urothelial bladder carcinomas and to clarify its association with histopathological variables. Materials and Methods: A total of 79 urothelial bladder carcinomas were selected from routine archival material. All cases were reevaluated histopathologically and graded according to the World Health Organization (WHO) 1973, WHO/ISUP 1998, and WHO 1999 systems. The TNM system was used for their pathological staging. CD10 immunohistochemical staining was performed in selected slides. Results: Tumoral cases consisted of 74 men (93.7%) and 5 women (6.3%). According to the pathological stage, 25 (31.6%), 33 (41.8%), and 21 (26.6%) cases had pTa, pT1, and pT2–3 carcinomas, respectively. 34 of 79 (43%) urothelial carcinomas and only 1 of 11 (9.1%) nontumoral cases showed positive CD10 immunostaining. It was a cytoplasmic diffuse or granular immunostaining pattern both in nontumoral and tumoral urothelia. There was no statistically significant difference between tumoral and nontumoral cases with respect to CD10 reactivity (p = 0.051), but there was a trend toward significance. In urothelial tumors, there was a significant inverse correlation between pathological stages and CD10 immunoreactivity (p = 0.036, r = –0,237). There was also a statistically significant difference between pTa and pT2–3 urothelial tumors in relation to the CD10 expression (p = 0.034). No association was detected between CD10 expression and grades according to all systems used (p > 0.05). Conclusions: According to our findings, the CD10 expression in noninvasive carcinomas showed a higher level than that in invasive carcinomas, and it is inversely correlated with the pathological stage. CD10 may play an important role in the progression of urothelial bladder carcinomas, and downregulation probably facilitates invasion, especially muscle invasion.
Optimal Nutrition Should Improve the Outcome and Costs of Radical Cystectomy
Authors: Barrass B.J.R. , Thurairaja R. , Collins J.W. , Gillatt D. , Persad R.A.
Published: August 2006

Introduction: Nutritional support has been demonstrated to improve recovery from radical cystectomy, but is expensive and when used inappropriately may actually increase the costs and morbidity of surgery. We sought to establish national patterns of practice with regard to feeding following cystectomy in the UK. Aims and Methods: Following consultation with the specialist nutrition team, a questionnaire was designed to investigate the feeding strategy after cystectomy and dispatched by post to all UK urologists. Results: The majority (60%) of respondents employed a traditional strategy of resting the bowel and feeding orally after bowel recovery. A minority used either early total parenteral nutrition (TPN; 18.5%) or enteral nutrition (6.5%), but a larger proportion (29%) felt enteral nutrition was the ‘optimal’ feeding regime. Only 30% used guidelines and 52% felt trials would help to establish a nutrition strategy following cystectomy. Conclusion: There is little evidence that TPN improves the outcome of cystectomy and it may actually increase morbidity and costs, whereas enteral nutrition may improve recovery. Despite this evidence TPN is widely used by urologists whereas enteral nutrition is used infrequently. Implementation of an evidence-based feeding regime after cystectomy is likely to reduce the morbidity and financial costs of cystectomy.
Comparison of Transperitoneal versus Retroperitoneal Approach in Laparoscopic Radical Nephrectomy for Renal Cell Carcinoma: A Single-Center Experience of 63 Cases
Authors: Berdjis Navid , Hakenberg Oliver W. , Leike Steffen , Zastrow Stefan , Manseck Andreas , Oehlschläger Sven , Wirth Manfred P.
Published: August 2006

Background: We report our experience with the retroperitoneal (RP) and transperitoneal (TP) approaches for laparoscopic nephrectomy for clinically localized renal cell carcinoma. Methods: Sixty-three patients with renal cell carcinoma were treated with laparoscopic nephrectomy, 34 by TP and 29 by RP approach between June 1999 and June 2003. Average age, ASA score, tumor stage and tumor size were similar in both groups. Early complications within 30 days and surgical time were retrospectively reviewed. Results: Surgical time was with a mean of 183 and 190 minutes equal for the TP and RP approach. Intraoperative complications occurred in 4 patients and were vascular, requiring blood transfusion in 2 patients each per group. Postoperative complications were thromboembolism in 1 patient and subcutaneous seroma in 1 patient, both in the TP group. Conclusions: Although the sample size is small, it appears that the tumor control and surgical time in laparoscopic nephrectomy are not significantly influenced by the approach.
Effects of Sildenafil Citrate (Viagra®) on Renal Arteries: An Evaluation with Doppler Ultrasound
Authors: Degirmenci Bumin , Acar Murat , Albayrak Ramazan , Haktanir Alpay , Yucel Aylin , Gecici Omer
Published: August 2006

Introduction: We aimed to determine hemodynamic alterations in renal arteries that may have resulted from oral intake of sildenafil citrate in healthy volunteers. Materials and Methods: Twelve healthy volunteers were included in our study. Renal Doppler ultrasonography (US) was performed before the drug intake to assess the basal values. Maximum peak systolic velocity, and resistivity and pulsatility indices were measured from the segmental branches of both renal arteries in all the ex- aminations. After the basal measurements 50 mg of sildenafil or placebo were randomly given to the 12 subjects. Renal Doppler US examinations were carried out 1 h after sildenafil or placebo intake. On the following day sildenafil was administered to the subjects who had previously taken placebo or vice versa. Renal Doppler US was repeated after 1 h. The effect of sildenafil on renal vascular hemodynamics was evaluated by comparison of basal values with postplacebo and postsildenafil values. Results: No statistically significant differences were found between the basal values of bilateral renal arteries and maximum peak systolic velocity, and resistivity and pulsatility index values measured after the placebo or sildenafil intake. Conclusion: We demonstrated that single-dose sildenafil did not cause any significant effect on renal artery hemodynamics in healthy individuals.
Indications and Results of Surgery for Incidentally Found Adrenal Tumors
Authors: Meyer A. , Behrend M.
Published: August 2006

Introduction: The accidental discovery of an adrenal mass called incidentaloma has become an increasingly frequent clinical problem with the question of a correct and appropriate therapeutic approach being the subject of controversial discussions. Materials and Methods: Clinical charts of 52 patients (22 male, 30 female) who underwent adrenalectomy for an incidentaloma at our institution between 1987 and 2001 were reviewed. Results: Median age was 56.4 years. Reasons for surgery were unclear significance in 22 patients, suspicion of malignancy in 5, increase in size in 8, maximum tumor diameter of more than 5 cm in 7, fear of malignancy in 1, and subclinical secretion of cortisol in 5 patients. No data were available for 4 patients. Surgical resection was performed usinga conventional transabdominal approach in 28 patients, a conventional dorsal approach in 17 patients, and an endoscopic retroperitoneal approach in 7 patients. Histopathologic examination ruled out adrenal adenoma in 32 patients, adrenal myelolipoma in 12, unilateral nodular hyperplasia in 4, cystic lesion in 3, and adrenocortical carcinoma in 1 patient. The mean size of all lesions was 5.5 cm. Evaluating the criteria for surgical treatment regarding age of the patients and size of the lesions, 25 patients (48%), including the patient with the adrenocortical carcinoma, were younger than 60 years and had an adrenal lesion exceeding 4 cm in size. During postoperative follow-up that was available for 39 patients, 3 developed contralateral tumors that were treated by resection in 1 and by close follow-up in 2. Conclusions: Size should not be the sole criterion; treatment should be tailored to the individual patient. Especially in patients younger than 60 years with an adrenal lesion exceeding 4 cm in size, an adrenalectomy, predominantly via an endoscopic approach, should be carried out, because a repeated and life-long close follow-up of an anxious patient who has been informed of the diagnosis will in some cases exceed the cost of a single endoscopic operation.
Risk Factors of Spontaneous Pneumothorax in Kuwait
Authors: Ayed Adel K. , Bazerbashi Samer , Ben-Nakhi Muneera , Chandrasekran Chezhian , Sukumar Murgan , Al-Rowayeh Aiman , Al-Othman Mohammed
Published: August 2006

Objectives: To determine the risk factors of spontaneous pneumothorax (SP) in Kuwait. Subjects and Methods: From January 2002 through December 2003, 254 consecutive cases with a diagnosis of SP were reviewed. Analyses of pneumothorax rates by age, sex, smoking, body mass index (BMI) and climatic conditions were evaluated. Results: Of the 254 patients, 242 (95%) were male and 12 (5%) were female; a larger proportion of 180 (88%) were Kuwaitis and 74 (12%) were expatriates. Two hundred and eight (82%) episodes were regarded as primary SP and 46 (18%) as secondary SP. The mean age was 24.5 ± 5.8 years for primary SP and 45.7 ± 14.5 years for secondary SP. One hundred and ninety-six (77%) individuals were current smokers. BMI in primary and secondary SP was 19.3 and 22.4, respectively (p < 0.001). There was no relationship between SP and climatic conditions (a rise or fall in temperature, humidity or atmospheric pressure). However, a slight increase in SP occurred in July, probably the hottest month in Kuwait. Conclusions: The data indicate that the most important risk factors of SP in Kuwait are smoking, low BMI and the male gender.
Intravenous Contrast Media in Uroradiology: Evaluation of Safety and Tolerability in Almost 50,000 Patients
Authors: Wendt-Nordahl Gunnar , Rotert Harald , Trojan Lutz , Michel Maurice Stephan , Peters Candida R. , Alken Peter , Knoll Thomas
Published: August 2006

Ojective: To evaluate the frequency of adverse events and possible risk factors after the administration of an intravenous contrast medium (CM), iobitridol, in a large multicentre postmarketing surveillance study. Subjects and Methods: A total of 49,975 patients undergoing intravenous urography were included in this study. A water-soluble, non-ionic CM (iobitridol, 1 ml/kg body weight) was administered. Age, sex, indication for the actual examination and adverse events were documented. Also, high-risk patients were identified. Results: Of the 49,975 patients, 28,336 (56.7%) were males and 21,639 (43.3%) females. Indications for urography were mainly urolithiasis (39.1%), inflammatory diseases (25.6%) and tumours (13.9%). Additionally, 7.4% were risk patients: 1.9% with creatinine >1.5 mg/dl (0.1% were on haemodialysis); 0.8% had a history of previous allergic reactions to CM, 3.7% pre-existing asthma or allergies and 2% other risk factors against CM examination. Only 0.9% of the patients experienced acute adverse events that were non-serious and transient. Less than 0.1% of the patients experienced vomiting, dizziness or cardiovascular problems. Only 1 patient developed an anaphylactic shock but recovered fully under treatment. A χ2 analysis revealed that adverse reactions occurred in patients with pre-existing renal insufficiency or allergies. Significantly more females had contrast-agent-related symptoms compared to men. Patients undergoing urography for urolithiasis had significantly fewer symptoms compared to patients with other indications. Conclusion: Iobitridol is clinically safe and well tolerated in urography as demonstrated in this study of a large patient population, producing mainly minor symptoms as adverse events. However, caution is advised when administering iobitridol to high-risk patients.
Sociodemographic and Clinical Characteristics of Patients with Dissociative Disorders in an Arabian Society
Authors: Bener Abdulbari , Saad Abul Gasim , Micallef Rosetta , Ghuloum Suhaila , Sabri Sufyan
Published: August 2006

Objective: The aim of the study was to determine the sociodemographic and clinical characteristics of patients with dissociative disorders among psychiatric patients in the population of the United Arab Emirates. Subjects and Methods: Six hundred inpatients with dissociative disorders were approached during the period 1997–2003, and 468 agreed to participate in the study. These patients were recruited from Al-Ain and Tawam Teaching Hospitals and Al-Jahili Primary Health Care Centers in Al-Ain, United Arab Emirates. The study is based on a questionnaire that included sociodemographic and clinical variables. Dissociative disorders were diagnosed according to the classification set forth in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) and the International Classification of Diseases (ICD-10) of the World Health Organization. Results: Of the 468 patients studied, the majority (67.9%) were young, under the age of 25 years; 55% were UAE nationals, 59.4% female and 40.6% male. Disorganized movement was significantly lower among females (34.2%) than males (44.2%, p < 0.03). Disapproving of the key relative behaviour was higher in females (24.1%) compared to males (13.2%); comorbid anxiety was higher in females (37.4%) vs. males (25.3%). Disturbed relationships were more common in females (40.3%) while precipitating factors, such as intolerable stressful events, were significantly higher in males (42.6%, p < 0.01). Furthermore, males (20.5%) had a significantly higher history of similar episodes and other psychiatric illnesses (7.5%) than females. Finally, females (41%) showed more statistically significant improvements compared to males (29.5%, p < 0.001). Conclusion: Patients under 25 years of age suffered more from dissociative disorders with no correlation to educational level as a predisposing factor. The most common symptoms were fits or unorganized movements.
Determination of Berberine Content in the Stem Extracts of Coscinium fenestratum by TLC Densitometry
Authors: Rojsanga Piyanuch , Gritsanapan Wandee , Suntornsuk Leena
Published: August 2006

Objective: To develop the optimal extraction procedure (i.e. maceration, percolation or Soxhlet extraction) and thin- layer chromatographic (TLC)-densitometric method for the determination of berberine content of Coscinium fenestratum. Materials and Methods: Maceration, percolation and Soxhlet extraction techniques were used to extract alkaloids from dried stems of C. fenestratum. The solvents used were 50 and 80% ethanol. Crude extracts and berberine content recovered from the TLC fingerprint were evaluated for chemical components of each extraction method. Precoated silica gel GF254 plates were used as stationary phase while butanol:glacial acetic acid:water (14:3:4) was used as a mobile phase. Detection and quantitation of berberine were performed by densitometry at the wavelength of 415 nm over the linearity range of 240–840 ng (r2 = 0.9982). The relative standard deviations from intraday and interday precisions were less than 4.13%. Results: The recovery of standard berberine was 97.58–98.71% (%RSD = 3.85), and the limit of detection and quantitation were 25 and 50 ng/spot, respectively. Eighty percent ethanol gave a higher content of berberine than 50% ethanol. Berberine contents from maceration, percolation and Soxhlet extraction with 80% ethanol were 3.37± 0.30, 3.08± 0.38 and 2.67± 0.27% w/w, respectively. Conclusion: The TLC-densitometric method was simple, accurate and precise for quantitating berberine in the stem extract of C. fenestratum. Maceration with 80% ethanol gave the highest content of berberine in the extract. TLC of the extracts from different methods showed a similar pattern.
Evidence, Education and Practice
Authors: Kaste Markku
Published: August 2006

Stroke causes greater loss of quality-adjusted life years than any other disease and is also one of the most expensive disorders. The burden of stroke will increase in the future due to change in the age structure of populations. We have a vast body of evidence on how to prevent stroke and how to treat stroke patients. Good examples are treatment of hypertension, antithrombotic agents and carotid surgery in stroke prevention, thrombolysis in ischaemic stroke and stroke unit care for all stroke patients. We only have to translate scientific evidence into daily practice. If some pieces are missing, it is our duty to generate them through research. While taking part in randomized clinical trials (RCTs), the discipline, an essential part of RCTs, will improve the daily care of all stroke patients. Besides RCTs there are many other sources of scientific evidence for stroke management, one of which is the European Stroke Initiative (EUSI). The mission of the EUSI is to improve and optimize stroke management in Europe through education and by offering best practice guidelines. Also national and international societies and organizations play an important role in providing education. The human factor is one obstacle to more successful stroke management because to be more effective we must change our own clinical routine. We can make a difference by applying available evidence to our daily practice.
Barthel Index in a Middle-East Country: Translation, Validity and Reliability
Authors: Oveisgharan Shahram , Shirani Shahin , Ghorbani Askar , Soltanzade Akbar , Baghaei Abdolmehdi , Hosseini Shindokht , Sarrafzadegan Nizzal
Published: August 2006

Background: In Iran, a Middle-East country, no disability scale has been translated and validated for use in stroke clinical trials. This study was designed to translate the Barthel Index and make its Persian translated form valid and reliable. Methods: All items of the Barthel Index were translated into Persian. Also, the Modified Rankin Scale (MRS) was also translated to Persian. Telephone interview was used as the method of data acquisition. Two interviewers were chosen for this means in order to accelerate data gathering and measure interrater agreement. Samples were selected from Isfahan Cardiovascular Research Center’s Stroke Registry Unit, a WHO collaborating center in the center of Iran. All the patients were registered as stroke or intracerebral hemorrhage (ICH). These patients were inhabitants of Isfahan Province who had suffered from stroke or ICH between 12 and 24 months before data acquisition. Chronbach’s alpha, test-retest reliability, concurrent validity with MRS, interrater agreement and item analysis were done for the translated questionnaire. Results: Translated questionnaires were filled by interview from 459 stroke patients. Their mean age was 68.11 ± 11.59 years. 243 of them were male (52.9%). Cronbach’s alpha was 0.9354. Spearman’s correlation coefficient between translated Barthel Index scores and MRS scores was –0.912. Spearman’s correlation coefficient between 2 scores, to determine test-retest reliability was 0.989. Concordance correlation to determine interrater agreement was 0.994. All corrected item–total correlations were greater than 0.5. Conclusions: The Persian translated version of the Barthel Index is a reliable and valid questionnaire for use in stroke clinical trials.
CT Angiography in Acute Stroke – Does It Provide Additional Information on Occurrence of Infarction and Functional Outcome after 3 Months?
Authors: Ritter Martin A. , Poeplau Tobias , Schaefer Anne , Kloska Stephan P. , Dziewas Rainer , Ringelstein E. Bernd , Heindel Walter , Nabavi Darius G.
Published: August 2006

Objective: To investigate whether acute phase intracranial CT angiography (CTA) independently predicts infarction and functional outcome in ischemic stroke. Methods: Hundred and fifty-one consecutive patients with acute (<12 h) ischemic stroke who received intracranial CTA were investigated. Stroke severity on admission was determined using the National Institute of Health Stroke Scale (NIHSS). Reconstructed CTAs were investigated for relevant pathology. Follow-up imaging was performed 24–48 h after admission. Functional outcome was assessed after 3 months using the modified Rankin scale. Single factor and multiple logistic regression analyses were performed to predict infarction and dependency (modified Rankin scale ≧ 3) on follow-up. Results: Median NIHSS on admission was 10 (IQR 3–14). Out of the 151 patients, 61 (40%) had pathological CTA findings. Infarction was demonstrated in 60/61 patients (98%) with and in 67/90 patients (74%) without vessel pathology. Presence of infarction on follow-up imaging and dependency at 3 months were correlated with pathological CTA findings on admission in single factor analysis (each p < 0.001). After adjustment for age (≧/<65 years), NIHSS (≧/<10), sex, therapy, and time to presentation (≧/<3 h), only NIHSS ≧10 on admission was predictive of dependency at follow-up (p < 0.001). Conclusions: Pathological CTA findings in the acute phase of ischemic stroke do not independently predict a poor outcome at 3 months after acute stroke.