bluuebunny/crossref_metadata_2025 huggingface dataset:
Simultaneous combined use of flexible ureteroscopy and percutaneous nephrolithotomy to reduce the number of access tracts in the management of complex renal calculi
Authors: Marguet Charles G. , Springhart W. Patrick , Tan Yeh H. , Patel Anup , Undre Shabnam , Albala David M. , Preminger Glenn M.
Published: October 2005

In a joint study between Duke University, North Carolina and London, a simultaneous combination of flexible ureteroscopy and percutaneous nephrolithotomy was used to reduce the number of access tracts required to manage complex renal calculi. This was found to be an effective method which reduced morbidity and blood loss, without increasing operating time, but without increasing stone‐free rates.

Authors from the USA carried out an experimental study to determine whether an electrode array with a bipolar radiofrequency ablation energy source could be used for partial nephrectomy, simultaneously ablating and coagulating renal tissue. They found that this system could indeed be used in a bloodless fashion with no collecting system injury.

OBJECTIVE

To present early experience in managing complex renal calculi using a combined ureteroscopic and percutaneous approach, as complex and branched renal calculi often require multiple access tracts during percutaneous nephrolithotomy (PNL), and the combined use of flexible ureteroscopy and PNL has the potential to reduce the inherent morbidity of several tracts.

PATIENTS AND METHODS

The study included seven patients (mean age 54 years) with multiple, branched, large‐volume renal calculi suitable for management with PNL. Preoperative data, including patient demographics, stone location and stone surface area, were recorded. After informed consent, the patients underwent combined PNL and ureteroscopy in one session. Intraoperative data, including the location of PNL puncture sites, operative duration and complications, were analysed. Stone‐free rates were determined by follow‐up imaging at 3 months.

RESULTS

All patients had either two or more stones in separate locations in the collecting system, or staghorn stones involving multiple calyces. The mean stone burden was 666 mm2. All patients had only one percutaneous access tract. The mean operative duration was 142 min and the mean blood loss 79 mL. Two patients had small residual stones (<3 mm), that required ureteroscopic intervention as they failed to pass spontaneously by 3 months after the initial combined procedure. The convalescence was similar to that in our current PNL practice; imaging showed that five of the patients were stone‐free.

CONCLUSIONS

Combined PNL and ureteroscopic management can effectively reduce the number of percutaneous access tracts which would otherwise be required for managing complex and branched renal calculi, as stones in an unfavourable location relative to the access tract can be relocated and fragmented within easy reach of the single nephrostomy tract. This manoeuvre reduces potential patient morbidity and blood loss but with no significant effect on stone‐free rates and operative durations.
Adult male circumcision: results of a standardized procedure in Kisumu District, Kenya
Authors: Krieger John N. , Bailey Robert C. , Opeya John , Ayieko Benard , Opiyo Felix , Agot Kawango , Parker Corette , Ndinya‐Achola Jeckoniah O. , Magoha George A.O. , Moses Stephen
Published: October 2005

In a combined study from the USA and Kenya, the safety of adult male circumcision in the latter country was reviewed, particularly with the purported association between this procedure and a lower incidence of HIV and other sexually‐transmitted infections. It was found that safe and acceptable adult male circumcision services could be delivered in developing countries should this be advocated as a public health measure.

OBJECTIVE

To develop a standard procedure for male circumcision in a resource‐poor medical setting and prospectively evaluate the outcome in a randomized, controlled trial with the incidence of human immunodeficiency virus (HIV) as the main outcome, as studies suggest that circumcision is associated with a lower incidence of HIV and other sexually transmitted infections in high‐risk populations.

SUBJECTS AND METHODS

Healthy, uncircumcised, HIV‐seronegative men aged 18–24 years from Kisumu District, Kenya, were offered participation in a clinical trial using a standard circumcision procedure based on ‘usual’ medical procedures in Western Kenya. The follow‐up included visits at 3, 8 and 30 days after circumcision, with additional visits if necessary. Healing, satisfaction and resumption of activities were assessed at these visits and 3 months from randomization.

RESULTS

Overall, 17 (3.5%) of the 479 circumcisions were associated with adverse events judged definitely, probably or possibly related to the procedure. The most common adverse events were wound infections (1.3%), bleeding (0.8%), and delayed wound healing or suture line disruption (0.8%). After 30 days, 99% of participants reported being very satisfied with the procedure; ≈ 23% reported having had sex and 15% reported that their partners had expressed an opinion, all of whom were very satisfied with the outcome. About 96% of the men resumed normal general activities within the first week after the procedure.

CONCLUSION

Safe and acceptable adult male circumcision services can be delivered in developing countries should male circumcision ultimately be advocated as a public‐health measure.
The effects of α1A‐adrenoceptor antagonists on the urethral perfusion pressure of the female rat
Authors: Bae Jae‐Hyun , Jung Phil‐Bum , Lee Jeong‐Gu
Published: October 2005

OBJECTIVE

To assess the effects of α1A‐adrenoceptor antagonists on urethral perfusion pressure (UPP) in the female rate and their therapeutic potential for treating female bladder outlet obstruction (BOO).

MATERIALS AND METHODS

A cannula was inserted into the femoral arteries of female rats to administer tamsulosin (group I), doxazosin (group II) or phentolamine (group III) and to monitor systemic blood pressure. Tamsulosin was also administered to male rats (group IV). UPP and vesical pressures (Pves) were monitored using a triple‐lumen catheter.

RESULTS

After administration of tamsulosin to group I the frequency of bladder contractions decreased significantly and the duration of minimal urethral relaxation with high‐frequency oscillations (HFOs) was significantly prolonged. Except for mean arterial blood pressure (MAP), none of the variables in group I differed significantly from those in group II and group III. The change in MAP after tamsulosin treatment was significantly lower than after doxazosin or phentolamine. Except for the maximum Pves, which was significantly higher in males (group IV) than in females of group I, the UPP and Pves curves of male rats were similar to those of females before giving tamsulosin. The prolonged frequency and duration of HFO in group IV (with tamsulosin) were significantly different from those of females.

CONCLUSIONS

The α1A‐adrenergic receptor may be a functional subtype in the female rat urethra. α1A‐adrenoceptor antagonists prolonged the duration of HFOs and decreased the frequency of involuntary bladder contraction. It is possible that treatment with α1A‐adrenoceptor antagonists would not only improve obstructive symptoms, but also ameliorate irritative symptoms by prolonging HFOs and the frequency of involuntary bladder contractions.
Panel unit root tests under cross‐sectional dependence
Authors: Breitung Jörg , Das Samarjit
Published: October 2005

In this paper alternative approaches for testing the unit root hypothesis in panel data are considered. First, a robust version of the Dickey‐Fuller t‐statistic under contemporaneous correlated errors is suggested. Second, the GLS t‐statistic is considered, which is based on the t‐statistic of the transformed model. The asymptotic power of both tests is compared against a sequence of local alternatives. To adjust for short‐run serial correlation of the errors, we propose a pre‐whitening procedure that yields a test statistic with a standard normal limiting distribution as N and T tends to infinity. The test procedure is further generalized to accommodate individual specific intercepts or linear time trends. From our Monte Carlo simulations it turns out that the robust OLS t‐statistic performs well with respect to size and power, whereas the GLS t‐statistic may suffer from severe size distortions in small and moderate sample sizes. The tests are applied to test for a unit root in real exchange rates.
Operations Research in passenger railway transportation
Authors: Huisman Dennis , Kroon Leo G. , Lentink Ramon M. , Vromans Michiel J. C. M.
Published: October 2005

In this paper we give an overview of state‐of‐the‐art Operations Research models and techniques used in passenger railway transportation. For each planning phase (strategic, tactical and operational), we describe the planning problems arising there and discuss some models and algorithms to solve them. We do not only consider classical, well‐known topics such as timetabling, rolling stock scheduling and crew scheduling, but we also discuss some recently developed topics such as shunting and reliability of timetables.

Finally, we focus on several practical aspects for each of these problems at the largest Dutch railway operator, NS Reizigers.
Left Ventricular Epicardial Activation Increases Transmural Dispersion of Repolarization in Healthy, Long QT, and Dilated Cardiomyopathy Dogs
Authors: BAI RONG , LÜ JIAGAO , PU JUN , LIU NIAN , ZHOU QIANG , RUAN YANFEI , NIU HUIYAN , ZHANG CUNTAI , WANG LIN , KAM RUTH
Published: October 2005

Background: Benefits of cardiac resynchronization therapy (CRT) are well established. However, less is understood concerning its effects on myocardial repolarization and the potential proarrhythmic risk.

Methods and Results: Healthy dogs (n = 8) were compared to a long QT interval (LQT) model (n = 8, induced by cesium chloride, CsCl) and a dilated cardiomyopathy with congestive heart failure (DCM‐CHF, induced by rapid ventricular pacing, n = 5). Monophasic action potential (MAP) recordings were obtained from the subendocardium, midmyocardium, subepicardium, and the transmural dispersion of repolarization (TDR) was calculated. The QT interval and the interval from the peak to the end of the T wave (Tp‐e) were measured. All these characteristics were compared during left ventricular epicardial (LV‐Epi), right ventricular endocardial (RV‐Endo), and biventricular (Bi‐V) pacing.

In healthy dogs, TDR prolonged to 37.54 ms for Bi‐V pacing and to 47.16 ms for LV‐Epi pacing as compared to 26.75 ms for RV‐Endo pacing (P < 0.001), which was parallel to an augmentation in Tp‐e interval (Bi‐V pacing, 64.29 ms; LV‐Epi pacing, 57.89 ms; RV‐Endo pacing, 50.29 ms; P < 0.01). During CsCl exposure, Bi‐V and LV‐Epi pacing prolonged MAPD, TDR, and Tp‐e interval as compared to RV‐Endo pacing. The midmyocardial MAPD (276.30 ms vs 257.35 ms, P < 0.0001) and TDR (33.80 ms vs 27.58 ms, P=0.002) were significantly longer in DCM‐CHF dogs than those in healthy dogs. LV‐Epi and Bi‐V pacing further prolonged the MAPD and TDR in this model.

Conclusions: LV‐Epi and Bi‐V pacing result in prolongation of ventricular repolarization time, and increase of TDR accounted for a parallel augmentation of the Tp‐e interval, which provides evidence that Tp‐e interval accurately represents TDR. These effects are magnified in the LQT and DCM‐CHF canine models in addition to their intrinsic transmural heterogeneity in the intact heart. This mechanism may contribute to the development of malignant ventricular arrhythmias, such as torsades de pointes (TdP) in congestive heart failure (CHF) patients treated with CRT.
Artificial Attenuation of ECG Voltage Produces Shortening of the Corresponding QRS Duration: Clinical Implications for Patients with Edema
Authors: MADIAS JOHN E. , MACFARLANE PETER W.
Published: October 2005

Background: Prolonged QRS duration (QRSd) is a useful index for the management of patients with congestive heart failure (CHF). QRSd is affected by changes in the ECG voltage (ECGV) in the context of development and amelioration of peripheral edema (PERE), independent of underlying pathology. Nowadays, physicians accept QRSd measured by computer techniques. The latter offers the possibility of testing the hypothesis that artificial alteration of the ECGV, simulating effects of PERE, could lead to changes in the QRSd.

Methods: To this end, voltage was attenuated by 25%, 50%, and 75% in 100 digital ECGs recorded from normal subjects and in 20 patients with complete left bundle branch block (LBBB), by merely increasing the calibration strength by 4/3, 2, and 4, respectively, and by using the same data.

Results: All ECGs were analyzed by the same computer program and this led to a reduction of global QRSd by 2.3 ± 2.9%, 5.7 ± 4.0%, and 11.9 ± 6.2%, respectively, in the normal subjects, and 1.6 ± 1.4%, 3.4 ± 1.7%, and 8.2 ± 3.6%, respectively, in the patients with LBBB. Correlation of the percent change in the global QRSd and the percent change in ECGV was good with an r = 0.65, and P = 0.00005 in the normal subjects, and an r = 0.74 and P = 0.00005 in the patients with LBBB.

Conclusions: Apparent shortening in QRSd as a function of ECGV attenuation due to PERE could have implications in the follow‐up of patients with CHF, and their selection for implantable cardioverter/defibrillators, or cardiac resynchronization therapy.
Severe Left Ventricular Systolic Dysfunction Increases Atrial Fibrillation After Ablation of Atrial Flutter
Authors: ZAMBITO PETER E. , TALREJA ASHOK , GUNDEWAR SUSHEEL , FISHER JOHN , FERRICK KEVIN , GROSS JAY , KIM SOO , PALMA EUGEN C.
Published: October 2005

Background: Atrial fibrillation (Afib) that occurs after a successful atrial flutter (AFL) ablation may negate the potential benefits of the ablation. Afib occurs more often when severe left ventricular systolic dysfunction (LVSD) is present. We hypothesized that even after a successful AFL ablation, the incidence of postablation Afib is increased when severe LVSD is present.

Methods: Ninety consecutive patients with LVSD who underwent ablation for AFL at Montefiore Medical Center from August 2001 to January 2005 were classified according to the severity of LVSD. Group 1 (n = 36) consisted of patients with EF ≤ 35%, and group 2 (n = 54) consisted of patients with EF 36–55%. There were no statistically significant differences in baseline patient characteristics between the two groups.

Results: During a mean follow up of 350 days, Afib occurred in 31% (n = 11; 8 with prior history of AFib) in group 1, and 7.4% (n = 4; all with prior history of Afib) in group 2. Cumulative probability of remaining Afib‐free in group 1 versus group 2 was 75% versus 96% at 365 days, and 69% versus 91% at 600 days (P = 0.01). A prior history of Afib did not interact with EF when analyzed with a logistic regression analysis.

Conclusion: After an AFL ablation, the incidence of Afib is increased, and the probability of remaining free of Afib is decreased, when severe LVSD is present, independent of a prior history of Afib. This finding may have implications for optimal patient selection for AFL ablation, and the use of adjunctive therapies.
Contralateral Replacement of Pacemaker and Leads Following Laser Sheath Extraction and Concomitant Stenting for Superior Vena Cava Syndrome
Authors: BAKIR IHSAN , LA MEIR MARC , DEGRIECK IVAN , MARIEN CATHERINE , VAN DEN HAUWE KRISTOF , WELLENS FRANCIS
Published: October 2005

We present the case of a 61‐year‐old man with a history of pacemaker implantation 15 years ago. The patient was admitted with chronic swelling of the right hemithorax and inflammation of the old incision scar after the replacement of pacemaker generator 6 years ago. The patient also presented symptoms and clinical signs of superior vena cava syndrome. Computed tomography of the thorax showed obstruction of the superior vena cava. The surgical procedure consisted of extraction of infected pacemaker system with excimer laser technique followed by dilatation and stenting of the SVC and finally implantation of a new permanent pacemaker system on the left side.
Right Heart Failure Due to Loss of Right Ventricular Capture in a Patient with Atrioventricular Junction Ablation and Biventricular Pacing
Authors: RAFFA SANTI , FANTONI CECILIA , RESTAURI LUIGIA , AURICCHIO ANGELO
Published: October 2005

We describe the case of a patient with atrioventricular (AV) junction ablation and chronic biventricular pacing in which intermittent dysfunction of the right ventricular (RV) lead resulted in left ventricular (LV) stimulation alone and onset of severe right heart failure. Restoration of biventricular pacing by increasing device output and then performing lead revision resolved the issue. This case provides evidence that LV pacing alone in patients with AV junction ablation may lead to severe right heart failure, most likely as a result of iatrogenic mechanical dyssynchrony within the RV. Thus, probably this pacing mode should be avoided in pacemaker‐dependent patients with heart failure.
Comparison of the Efficacy of Cooled‐Tip and 8‐mm‐Tip Catheters for Radiofrequency Catheter Ablation of the Cavotricuspid Isthmus: A Meta‐Analysis
Authors: DA COSTA ANTOINE , CUCHERAT MICHEL , PICHON NATHALIE , MESSIER MARC , LAPORTE SYLVIE , ROMÉYER‐BOUCHARD CÉCILE , MISMETTI PATRICK , LOPEZ MICHEL , ISAAZ KARL
Published: October 2005

Background: Cooled‐tip RFA (cRFA) and conventional 8‐mm‐tip catheters were found to be more effective and as safe as conventional 4‐mm‐tip catheters for atrial flutter (AFL) radiofrequency ablation (RFA), facilitating the rapid achievement of bi‐directional isthmus block (BIB), but studies comparing cRFA and 8‐mm‐tip catheters are not randomized or results are discussed. Thus, we performed a meta‐analysis of available randomized trials to evaluate the effectiveness in terms of primary success and procedure parameters.

Methods: Reports of trials were identified through a Medline, Embase, Current Contents, Cardline, and an extensive bibliography search. Trials that met the following criteria were included: (1) prospective, randomized, controlled, and open trials; (2) patients assigned to an 8‐mm‐tip or a cRFA catheter for AFL RFA; (3) endpoints events related to primary success rate (BIB achievement), and procedure parameters (number of RF applications, x‐ray exposure and ablation duration).

Results: Seven trials met the inclusion criteria. They included 603 patients with established AFL randomized to an 8‐mm‐tip or cRFA catheter group. Comparing 8‐mm groups with cRFA groups, the meta‐analysis showed similar BIB achievement relative risk (RR) 0.96, 95% confidence interval (CI): 0.92 to 1.01, (P = 0.13); total RF application time weighted mean difference (WMD) 0.88, 95% CI: −0.36 to 2.12, (P = 0.16); duration of x‐ray exposure (min) (WMD = 1.07, 95% CI: −0.81 to 0.295, (P = 0.26); ablation procedure duration (min) (WMD = 0.68, 95% CI: −3.37 to 4.73; P = 0.74).

Conclusion: The present meta‐analysis confirms that cooled‐tip and large‐tip catheters are equally efficient for cavotricuspid isthmus ablation with both similar primary success rates and procedure parameters.
Automated Ventricular Substrate Mapping—Evaluation in an Ovine Chronic Myocardial Infarction Model
Authors: THIAGALINGAM ARAVINDA , POULIOPOULOS JIM , BARRY MICHAEL ANTHONY (TONY) , BOYD ANITA C. , EIPPER VICKI E. , YUNG TERESA , MACLEAN FIONA , ROSS DAVID L. , KOVOOR PRAMESH
Published: October 2005

Introduction: We hypothesized that automated electrogram analysis might enable rapid localization of ventricular scar. This would allow the delivery of interventions such as radiofrequency ablation or therapeutic agents to critical areas within the scar and scar periphery.

Methods: Substrate mapping was performed on seven sheep 36.5 ± 32.9 weeks after a left anterior descending artery myocardial infarction had been induced. Contact electrograms and the mapping catheter three‐dimensional (3D) location were recorded simultaneously. A computer program was written in‐house to automatically identify sinus beats, analyze electrogram characteristics (e.g., electrogram amplitude and minimum slope), and integrate the analysis results into a 3D scar map.

Results: The total time required to produce the scar maps was a mean of 8.3 ± 2.0 minutes. The automated substrate mapping (ASM) system beat detection algorithm had a high sensitivity (i.e., detected 87.4% of the recorded beats) and excellent specificity (only one false activation over 58.2 minutes of total recorded data). The system was able to classify the detected beats (‘sinus’ or ‘ectopic’) with high specificity (specificity = 97.3% confidence interval (CI): 96.9–97.7) and moderate sensitivity (sensitivity = 78.3% CI: 77.3%–79.5%). The scar area identified by the ASM system correlated well with the pathologically defined scar area (R2= 0.87 p < 0.001).

Conclusions: ASM enables accurate scar maps to be produced rapidly. This strategy may play an important role for both clinical and research applications, allowing therapeutic agents and radiofrequency ablation to be delivered to critical locations in and around ventricular scar.
Changes in Intrathoracic Impedance from a Pneumothorax: Insights from an Implanted Monitoring System
Authors: TIMPERLEY JONATHAN , MITCHELL ANDREW R.J. , BROWN PETER , BETTS TIMOTHY R.
Published: October 2005

The measurement of transthoracic impedance is now possible using new implantable cardioverter‐defibrillators. This can be used to monitor fall in impedance associated with increasing pulmonary oedema. We describe a case of a large rapid increase of impedance and dyspnoea related to a pneumothorax.
Chronotropic Incompetence in Patients with an Implantable Cardioverter Defibrillator: Prevalence and Predicting Factors
Authors: MELZER CHRISTOPH , BÖHM MARCO , BONDKE HANS JOACHIM , COMBS WILLIAM , BAUMANN GERT , THERES HEINZ
Published: October 2005

Chronotropic incompetence (CI), which has not been systematically examined in the ICD patient population, may have implications for device programming. A total of 123 ICD patients were classified into three groups: single‐chamber ICD with sinus rhythm, dual‐chamber ICD with sinus rhythm, and single‐chamber ICD with permanent atrial fibrillation. Heart rate response, maximum oxygen uptake, and oxygen uptake at the anaerobic threshold were measured during treadmill exercise testing. In addition, clinical variables such as antiarrhythmic drug therapy, underlying heart disease, and left‐ventricular (LV) ejection fraction were recorded. Of the patients studied, 38% were chronotropically incompetent (47/123). Significant predictors of CI were as follows: presence of a coronary disease (P = 0.036), prior cardiac surgery (P = 0.037), chronic drug therapy with β‐blockers (P = 0.032), administration of amiodarone (P = 0.025), and a combination of these two forms of treatment (P = 0.01). Spiroergometry revealed reduced exercise capacity (P = 0.041) and lessened Vo2max (P = 0.034) among chronotropically incompetent patients. A large percentage of ICD patients demonstrates CI with subsequently reduced physical stress tolerance. In light of the DAVID study, we believe that a closer examination of rate‐adaptive modes for ICD patients is warranted under enhanced conditions: (1) optimized AV interval programming; (2) utilization of new algorithms to reduce ventricular pacing in combination with rate‐adaptive atrial pacing, with the goal of addressing CI while minimizing ventricular pacing; and (3) an optimized upper heart‐rate limit.
Cyclooxygenase‐2 inhibition selectively attenuates bone morphogenetic protein‐6 synthesis and bone formation during guided tissue regeneration in a rat model
Authors: Damrongsri Damrong , Geva Sarah , Salvi Giovanni E. , Williams Ray C. , Limwongse Visaka , Offenbacher Steven
Published: October 2005

AbstractObjectives:Bone formation during guided tissue regeneration is a tightly regulated process involving cells, extracellular matrix and growth factors. The aims of this study were (i) to examine the expression of cyclooxygenase‐2 (COX‐2) during bone regeneration and (ii) the effects of selective COX‐2 inhibition on osseous regeneration and growth factor expression in the rodent femur model.

Material and methods:A standardized transcortical defect of 5 × 1.5 mm was prepared in the femur of 12 male rats and a closed half‐cylindrical titanium chamber was placed over the defect. The expression of COX‐2 and of platelet‐derived growth factor‐B (PDGF‐B), bone morphogenetic protein‐6 (BMP‐6) and insulin‐like growth factor‐I/II (IGF‐I/II) was analyzed at Days 3, 7, 21 and 28 semiquantitatively by reverse transcriptase‐polymerase chain reaction and immunohistochemistry. The effects of COX‐2 inhibition by intraperitoneal injection of NS‐398 (3 mg/kg/day) were analyzed in five additional animals sacrificed at Day 14.

Results:Histomorphometry revealed that new bone formation occurred in the cortical defect area as well as in the supracortical region, i.e. region within the chamber by Day 7 and increased through Day 28. Immunohistochemical evidence of COX‐2 and PDGF‐B levels were observed early (i.e. Day 3) and decreased rapidly by Day 7. BMP‐6 expression was maximal at Day 3 and slowly declined by Day 28. In contrast, IGF‐I/II expression gradually increased during the 28‐day period. Systemic administration NS‐398 caused a statistically significant reduction (P<0.05) in new bone formation (25–30%) and was associated with a statistically significant reduction in BMP‐6 protein and mRNA expression (50% and 65% atP<0.05 andP<0.01, respectively). PDGF‐B mRNA or protein expression was not affected by NS‐398 treatment.

Conclusion:COX‐2 inhibition resulted in reduced BMP‐6 expression and impaired osseous regeneration suggesting an important role for COX‐2‐induced signaling in BMP synthesis and new bone formation.
GLUT8 Contains a [DE]XXXL[LI] Sorting Motif and Localizes to a Late Endosomal/Lysosomal Compartment
Authors: Augustin Robert , Riley Joan , Moley Kelle H.
Published: October 2005

Glucose transporter 8 (GLUT8) contains a cytoplasmic N‐terminal dileucine motif and localizes to a thus far unidentified intracellular compartment. Translocation of GLUT8 to the plasma membrane (PM) was found in insulin‐treated mouse blastocysts. Using overexpression of GLUT8 in adipocytes and neuronal cells however, insulin treatment or depolarization of the cells did not lead to GLUT8 PM translocation in other studies. In addition, other experiments showing dynamin‐dependent endocytosis of GLUT8 suggested that GLUT8 recycles between an endosomal compartment and the PM. To reveal the functional/physiological role of GLUT8, we studied its subcellular localization in 3T3L1, HEK293 and CHO cells. We show that GLUT8 does not co‐localize with GLUT4 and does not redistribute to the PM after treatment with insulin, ionophores or okadaic acid in these cell lines. Once endocytosed, GLUT8 does not recycle to the PM. GLUT8 localizes to late endosomes and lysosomes. An interspecies GLUT8 ‐ sequence alignment revealed the presence of a highly conserved late endosomal/lysosomal‐targeting motif ([DE]XXXL[LI]). Changing the glutamate to arginine as found in GLUT4 (RRXXXLL) alters GLUT8 endocytosis and retains the transporter at the PM. Furthermore, sorting GLUT8 to late endosomes/lysosomes does not require prior presence of GLUT8 at the PM followed by its endocytosis. In summary, GLUT8 does not reside in a recycling vesicle pool and is distinct from GLUT4. From our data, we postulate a role for GLUT8 in transport of hexoses across intracellular membranes, for example in specific compartments of GLUT8 expression such as the acrosome of mature spermatozoa or secretory granules in neurons. Furthermore, a role for GLUT8 in hexose transport across the lysosomal membrane, a transport mechanism that has long been suggested but unexplained, is discussed.
A new clan of CBM families based on bioinformatics of starch‐binding domains from families CBM20 and CBM21
Authors: Machovič Martin , Svensson Birte , Ann MacGregor E. , Janeček Štefan
Published: October 2005

Approximately 10% of amylolytic enzymes are able to bind and degrade raw starch. Usually a distinct domain, the starch‐binding domain (SBD), is responsible for this property. These domains have been classified into families of carbohydrate‐binding modules (CBM). At present, there are six SBD families: CBM20, CBM21, CBM25, CBM26, CBM34, and CBM41. This work is concentrated on CBM20 and CBM21. The CBM20 module was believed to be located almost exclusively at the C‐terminal end of various amylases. The CBM21 module was known as the N‐terminally positioned SBD of Rhizopus glucoamylase. Nowadays many nonamylolytic proteins have been recognized as possessing sequence segments that exhibit similarities with the experimentally observed CBM20 and CBM21. These facts have stimulated interest in carrying out a rigorous bioinformatics analysis of the two CBM families. The present analysis showed that the original idea of the CBM20 module being at the C‐terminus and the CBM21 module at the N‐terminus of a protein should be modified. Although the CBM20 functionally important tryptophans were found to be substituted in several cases, these aromatics and the regions around them belong to the best conserved parts of the CBM20 module. They were therefore used as templates for revealing the corresponding regions in the CBM21 family. Secondary structure prediction together with fold recognition indicated that the CBM21 module structure should be similar to that of CBM20. The evolutionary tree based on a common alignment of sequences of both modules showed that the CBM21 SBDs from α‐amylases and glucoamylases are the closest relatives to the CBM20 counterparts, with the CBM20 modules from the glycoside hydrolase family GH13 amylopullulanases being possible candidates for the intermediate between the two CBM families.
Characterization of solanesyl and decaprenyl diphosphate synthases in mice and humans
Authors: Saiki Ryoichi , Nagata Ai , Kainou Tomohiro , Matsuda Hideyuki , Kawamukai Makoto
Published: October 2005

The isoprenoid chain of ubiquinone (Q) is determined by trans‐polyprenyl diphosphate synthase in micro‐organisms and presumably in mammals. Because mice and humans produce Q9 and Q10, they are expected to possess solanesyl and decaprenyl diphosphate synthases as the determining enzyme for a type of ubiquinone. Here we show that murine and human solanesyl and decaprenyl diphosphate synthases are heterotetramers composed of newly characterized hDPS1 (mSPS1) and hDLP1 (mDLP1), which have been identified as orthologs of Schizosaccharomyces pombe Dps1 and Dlp1, respectively. Whereas hDPS1 or mSPS1 can complement the S. pombe dps1 disruptant, neither hDLP1 nor mDLP1 could complement the S. pombe dLp1 disruptant. Thus, only hDPS1 and mSPS1 are functional orthologs of SpDps1. Escherichia coli was engineered to express murine and human SpDps1 and/or SpDlp1 homologs and their ubiquinone types were determined. Whereas transformants expressing a single component produced only Q8 of E. coli origin, double transformants expressing mSPS1 and mDLP1 or hDPS1 and hDLP1 produced Q9 or Q10, respectively, and an in vitro activity of solanesyl or decaprenyl diphosphate synthase was verified. The complex size of the human and murine long‐chain trans‐prenyl diphosphate synthases, as estimated by gel‐filtration chromatography, indicates that they consist of heterotetramers. Expression in E. coli of heterologous combinations, namely, mSPS1 and hDLP1 or hDPS1 and mDLP1, generated both Q9 and Q10, indicating both components are involved in determining the ubiquinone side chain. Thus, we identified the components of the enzymes that determine the side chain of ubiquinone in mammals and they resembles the S. pombe, but not plant or Saccharomyces cerevisiae, type of enzyme.
Crystal structure of the β‐chain of human hepatocyte growth factor‐like/macrophage stimulating protein
Authors: Carafoli Federico , Chirgadze Dimitri Y. , Blundell Tom L. , Gherardi Ermanno
Published: October 2005

Hepatocyte growth factor like/macrophage stimulating protein (HGFl/MSP) and hepatocyte growth factor/scatter factor (HGF/SF) define a distinct family of vertebrate‐specific growth factors structurally related to the blood proteinase precursor plasminogen and with important roles in development and cancer. Although the two proteins share a similar domain structure and mechanism of activation, there are differences between HGFl/MSP and HGF/SF in terms of the contribution of individual domains to receptor binding. Here we present a crystal structure of the 30 kDa β‐chain of human HGFl/MSP, a serine proteinase homology domain containing the high‐affinity binding site for the RON receptor. The structure describes at 1.85 Å resolution the region of the domain corresponding to the receptor binding site recently defined in the HGF/SF β‐chain, namely the central cleft harboring the three residues corresponding to the catalytic ones of active proteinases (numbers in brackets define the sequence position according to the standard chymotrypsinogen numbering system) [Gln522 (c57), Gln568 (c102) and Tyr661 (c195)] and an adjacent loop flanking the S1 specificity pocket and containing residues Asn682 (c217) and Arg683 (c218) previously shown to be essential for binding of HGFl/MSP to the RON receptor. The study confirms the concept that the serine proteinase homology domains of HGFl/MSP and HGF/SF bind their receptors in an ‘enzyme‐substrate’ mode, reflecting the common evolutionary origin of the plasminogen‐related growth factors and the proteinases of the clotting and fibrinolytic pathways. However, analysis of the intermolecular interactions in the crystal lattice of β‐chain HGFl/MSP fails to show the same contacts seen in the HGF/SF structures and does not support a conserved mode of dimerization of the serine proteinase homology domains of HGFl/MSP and HGF/SF responsible for receptor activation.
TERMINOLOGY DEVELOPMENT AND PANEL TRAINING FOR SENSORY EVALUATION OF SKIN CARE PRODUCTS INCLUDING AQUA CREAM
Authors: LEE IN‐SUK , YANG HYUN‐MI , KIM JIN‐WHANG , MAENG YOO‐JAE , LEE CHI‐WOO , KANG YUN‐SEOK , RANG MOON‐JEONG , KIM HYE‐YOUNG
Published: October 2005

This article describes the approach of the spectrum descriptive analysis (SDA) method to evaluate sensory properties of skin care products. The terminology for various lotions and creams was developed using SDA. A total of 26 attributes on five phases was developed with definitions and scales. Through discriminative, descriptive and scaling testing, 10 panelists were selected, and panel training was conducted until the panel grand standard deviation of the evaluated data of calibration samples showed less than 1.0. After the extensive training on sensory perceptions and scaling, the panelists evaluated the 26 attributes on 12 aqua‐cream products. In the principal component analysis result of aqua‐cream data, the first principal component (PC) was mainly related to oiliness, viscosity, adhesiveness and thickness on one side of the scale and transparency, wetness, coolness and spreadability on the other, with 40% of variance. The stickiness and gloss contributed greatly to the second PC with 30% of variance. The total amount of variance that was explained at the two PCs was 78%. In the biplot loadings of products and attributes, creams of K and L were identified by their higher degrees of wetness, spreadability and moisturization. They had lower degrees of stickiness, gloss and oiliness.
SOURCES OF ERROR AND THE NO‐PREFERENCE OPTION IN DAIRY PRODUCT TESTING
Authors: CHAPMAN KATHRYN W. , LAWLESS HARRY T.
Published: October 2005

When products are physically identical, consumers will choose a no‐preference option in a paired preference test only about 30% of the time, giving a nonintuitive result. We evaluated the no‐preference false alarm rate in dairy products and the potential sources of error in panelist behavior, including discrimination problems and poor repeatability of judgments. Paired preference tests were conducted with milk (2% versus nonfat or skim), with cottage cheese (4% versus nonfat) and with identical samples. Triangle, dual standard and same/different discrimination tests were also conducted. The no‐preference option was chosen by about 30% of the consumers when samples were identical, and less frequently when samples were different. Discrimination performance, although statistically significant, was poorer than expected with about 30% discriminators (d′ of 1.7) in most tests. Even in the dual standard tests on milk (visually obvious and with references present), performance was only 88% correct (76% discriminators). Repeatability in preference tests was also poorer than expected, with only 56% choosing the same preference option for different samples on repeat trials although the group preferences were stable. Same/different tests indicated that over 50% of the consumers called identical samples different, although this fell short of explaining the 70% average false alarm rate in preferences. Even with apparently discriminable consumer products, accurate discrimination of the samples and repeatability of preferences should not be assumed. Random responding may contribute to error variance and produce nonsensical results such as the expression of choice between identical samples.
Wrinkling of Wide Sandwich Panels∕Beams With Orthotropic Phases by an Elasticity Approach
Authors: Kardomateas G. A.
Published: October 2005

There exist many formulas for the critical compression of sandwich plates, each based on a specific set of assumptions and a specific plate or beam model. It is not easy to determine the accuracy and range of validity of these rather simple formulas unless an elasticity solution exists. In this paper, we present an elasticity solution to the problem of buckling of sandwich beams or wide sandwich panels subjected to axially compressive loading (along the short side). The emphasis on this study is on the wrinkling (multi-wave) mode. The sandwich section is symmetric and all constituent phases, i.e., the facings and the core, are assumed to be orthotropic. First, the pre-buckling elasticity solution for the compressed sandwich structure is derived. Subsequently, the buckling problem is formulated as an eigen-boundary-value problem for differential equations, with the axial load being the eigenvalue. For a given configuration, two cases, namely symmetric and anti-symmetric buckling, are considered separately, and the one that dominates is accordingly determined. The complication in the sandwich construction arises due to the existence of additional “internal” conditions at the face sheet∕core interfaces. Results are produced first for isotropic phases (for which the simple formulas in the literature hold) and for different ratios of face-sheet vs core modulus and face-sheet vs core thickness. The results are compared with the different wrinkling formulas in the literature, as well as with the Euler buckling load and the Euler buckling load with transverse shear correction. Subsequently, results are produced for one or both phases being orthotropic, namely a typical sandwich made of glass∕polyester or graphite∕epoxy faces and polymeric foam or glass∕phenolic honeycomb core. The solution presented herein provides a means of accurately assessing the limitations of simplifying analyses in predicting wrinkling and global buckling in wide sandwich panels∕beams.
Dynamic Analysis of the Optical Disk Drives Equipped with an Automatic Ball Balancer with Consideration of Torsional Motions
Authors: Chao Paul C. P. , Sung Cheng-Kuo , Wang Chun-Chieh
Published: October 2005

This study is dedicated to evaluate the performance of an automatic ball-type balancer system (ABS) installed in optical disk drives (ODDs) with consideration of the relative torsional motion between the ODD case and the spindle-disk-ABS-turntable system, noting that the turntable is the supporting plate structure for disk, pickup, and spindle motor inside the ODD. To this end, a complete dynamic model of the ABS considering the torsional motion is established with assuming finite torsional stiffness of the damping washers, which provides suspension of the spindle-disk-ABS-turntable system to the ODD case. Considering the benchmark case of a pair of balancing balls in an ABS, the method of multiple scales is then applied to formulate a scaled model for finding all possible steady-state solutions of ball positions and analyzing corresponding stabilities. The results are used to predict the levels of residual vibration, with which the performance of the ABS can then be reevaluated. Numerical simulations are conducted to verify theoretical results. It is deduced from both analytical and numerical results that the spindle speed of an ODD could be operated above both primary translational and secondary torsional resonances in order to guarantee stabilization of the desired balanced solution for a substantial vibration reduction.
Three-Dimensional Contact Boundary Element Method for Roller Bearing
Authors: Shen Guangxian , Shu Xuedao , Li Ming
Published: October 2005

The analysis of the forces and the rigidity of roller bearings is a multi-body contact problem, so it cannot be solved by contact boundary element method (BEM) for two elastic bodies. Based on the three-dimensional elastic contact BEM, according to the character of roller bearing, the new solution given in this paper replaces the roller body with a plate element and traction subelement. Linear elements are used in non-contact areas and a quadratic element is used in the contact area. The load distribution among the roller bodies and the load status in the inner rolling body can be extracted.
Evolution of Wrinkles in Elastic-Viscoelastic Bilayer Thin Films
Authors: Im S. H. , Huang R.
Published: October 2005

This paper develops a model for evolving wrinkles in a bilayer thin film consisting of an elastic layer and a viscoelastic layer. The elastic layer is subjected to a compressive residual stress and is modeled by the nonlinear von Karman plate theory. A thin-layer approximation is developed for the viscoelastic layer. The stability of the bilayer and the evolution of wrinkles are studied first by a linear perturbation analysis and then by numerical simulations. Three stages of the wrinkle evolution are identified: initial growth of the fastest growing mode, intermediate growth with mode transition, and, finally, an equilibrium wrinkle state.
Elastic Fields due to Eigenstrains in a Half-Space
Authors: Liu Shuangbiao , Wang Qian
Published: October 2005

Engineering components inevitably encounter various eigenstrains, such as thermal expansion strains, residual strains, and plastic strains. In this paper, a set of formulas for the analytical solutions to cases of uniform eigenstrains in a cuboidal region-influence coefficients, is presented in terms of derivatives of four key integrals. The linear elastic field caused by arbitrarily distributed eigenstrains in a half-space is thus evaluated by the discrete correlation and fast Fourier transform algorithm, along with the discrete convolution and fast Fourier transform algorithm. By taking advantage of both the convolution and correlation characteristics of the problem, the formulas of influence coefficients and the numerical algorithms are expected to enable efficient and accurate numerical analyses for problems having nonuniform distribution of eigenstrains and for contact problems.
Demonstrating Beats with Springs and a Cart
Authors: Andersson Brian , Dykoski Matthew
Published: October 2005

The topic of beats is often discussed with reference to sound in high school or introductory college physics. Beats are easy to hear but a demonstration of a mechanical analog is rarely, if ever, presented. This paper describes a straightforward demonstration to produce low-frequency beats in a mechanical system. In this system, students can observe beats and the means by which they are created. This demonstration can also be adapted to the student laboratory where quantitative measurements are possible.
Photocopied Beats
Authors: Greenslade Thomas B.
Published: October 2005

I have done demonstrations of audible beats with tone bars, with function generators and speakers, and with resonating columns, and also visible beats with combs.1 In looking for a new beats demonstration, I regretted never having taken a picture of an overpass with wire fencing on both sides: the otherwise identical fencing shows visual beats because the two repeating patterns are at different distances from the observer.
Double-Exponential LR Circuit
Authors: Mungan Carl E.
Published: October 2005

Simple LR and RC circuits are familiar to generations of physics students as examples of single-exponential growth and decay in the relevant voltages, currents, and charges. An element of novelty can be introduced by connecting two (instead of one) LR coils in parallel with a battery. The resulting circuit can still be treated using little more than the basic tools (Kirchhoff's rules plus a trial exponential solution) employed in the standard LR analysis. But the solution is now a double exponential, as can be verified by constructing such a circuit.
Resistance Is Not Futile: Air Resistance in an Algebra-Based Course
Authors: Lovatt Ian , Innes Bill
Published: October 2005

In this paper we show that an object's terminal speed due to air resistance depends not on any of the object's details, but only on the distance at which an object reaches a particular fraction of its terminal speed. We show this graphically and algebraically. Although a mathematical treatment of air resistance is beyond the scope of an algebra-based, introductory physics course, some of the concepts involved are important for (at least) three reasons. First, the equations used for uniform acceleration only approximately (and perhaps badly!) describe projectiles students know (a home-run baseball, for example). With the equation for terminal speed, students can estimate the speeds at which the simple kinematic equations no longer produce “reasonable” approximations.
An Inexpensive Technique to Measure Coefficients of Friction with Rolling Solids
Authors: Carvalho Paulo Simeão , Sampaio e Sousa Adriano
Published: October 2005

Frictional forces are everywhere. They are probably among the most important macroscopic forces in our daily routine because we depend on them to walk, to pick up objects, and even to eat! They affect our lives in different ways, and thus it is very important to understand them better; this is what we say to our students. There are many experimental methods and techniques to measure static and kinetic frictional forces (and to determine their corresponding coefficients of friction), which we can find in several textbooks.1–5 Most of them involve pulling/pushing blocks along a flat surface and expensive equipment for accurate measuring (sensors, computers, etc.). In this paper we show how to find both coefficients of friction, static and kinetic, with rolling objects instead of blocks in a very simple way and using nonexpensive laboratory equipment.
Modeling the acoustic scattering by under-ice-ridge keels
Authors: Rubenstein David , Greene Robert
Published: October 2005

In this paper, the exact solution of scattering off a flat surface with a single semielliptical cylindrical boss of infinite extent is developed. The cylindrical boss approximates the geometric shape of an ice-ridge keel. A far-field approximation and the results to a grid of randomly distributed scatterers are applied. First, the case where the simulated keels have a single, constant depth is examined. In the frequency range below 200 Hz, energy is scattered mostly into steep angles, where it is eventually lost to bottom absorption. Above 200 Hz, a significant fraction of the scattered energy is directed into shallow angles, where it becomes a propagating incoherent component. Statistics are developed that describe a Rayleigh distribution of keel depths. A formula is developed that relates the standard deviation of surface roughness to mean keel depth and mean ice-ridge spacing. Then the model is applied to find that for a given ice roughness, a Rayleigh distribution yields less coherent reflection loss, and slightly less scattering loss, than a field of constant keel depths.