bluuebunny/crossref_metadata_2025 huggingface dataset:
The development of a quantitative enzyme‐linked immunosorbent assay to detect human platelet factor 4
Authors: Schraw Todd , Whiteheart Sidney
Published: April 2005

BACKGROUND: Platelet factor 4 (PF4) is a marker for in vitro and in vivo tests of platelet (PLT) activation and α‐granule secretion. PF4 is also a major CXC cytokine released during storage. Cytokines released during PLT storage are a potential cause of nonhemolytic transfusion reactions. Quantitative measurement of PF4 requires an assay that is both reliable and sensitive. To achieve this goal, a sensitive, cost‐effective, sandwich enzyme‐linked immunosorbent assay (ELISA) was developed with commercially available antibodies to human PF4.

STUDY DESIGN AND METHODS: An ELISA was developed for measuring PF4 from whole human PLTs or secreted from activated PLTs. Optimal concentrations of capture antibody, detection antibody, and enzyme‐conjugate were determined with serial twofold dilutions of recombinant PF4. This assay was used to determine the ideal sample dilutions needed for reliable quantitation of PF4 in releasates or from whole PLT extracts.

RESULTS: Serial dilutions of recombinant PF4 resulted in a sigmoid titration curve with a maximal sensitivity of 10 pg and a dynamic quantitative range from 100 to 2500 pg. This ELISA was used to measure secretion from permeabilized PLTs stimulated with free calcium. In a secretion experiment with 2.5 × 10|*bsup*|8|*esup*| PLTs per mL, samples required a 1:10‐fold dilution to reliably evaluate α‐granule release.

CONCLUSION: The parameters described yield an ELISA method with low background and high sensitivity over a range of PF4 concentrations. Using the commercial reagents described makes this assay cost‐effective and therefore suitable for analyzing multiple samples in the research setting.
Detection of bacteria in platelet concentrates: comparison of broad‐range real‐time 16S rDNA polymerase chain reaction and automated culturing
Authors: Mohammadi Tamimount , Pietersz Ruby N.I. , Vandenbroucke‐Grauls Christina M.J.E. , Savelkoul Paul H.M. , Reesink Henk W.
Published: April 2005

BACKGROUND: Based on real‐time polymerase chain reaction (PCR) technology, a broad‐range 16S rDNA assay was validated and its performance was compared to that of an automated culture system to determine its usefulness for rapid routine screening of platelet concentrates (PCs).

STUDY DESIGN AND METHODS: The presence of bacteria in pooled PCs was routinely assessed in an automated culturing system (BacT/ALERT, bioMérieux). The PCR assay was performed with DNA extracted from the same samples as used for culturing. DNA extraction was performed with a automated extraction system (MagNA Pure, Roche Diagnostics). PCR amplification was performed with a set of universal primers and probe targeting eubacterial 16S rDNA.

RESULTS: A total of 2146 PCs were tested. Eighteen (0.83%) samples were found to be contaminated. These samples were positive for the presence of bacteria by both methods. All contaminants were identified as bacteria belonging to the common human skin flora. These included Propionibacterium spp. (n = 7), Staphylococcus spp. (n = 6), Bacillus spp. (n = 2), Micrococcus spp. (n = 2), and Peptostreptococcus spp. (n = 1). Estimation of the bacterial load in PCs by real‐time PCR showed that the initial levels of contamination varied between 13.6 and 9 × 104 colony‐forming unit equivalents per PCR procedure.

CONCLUSIONS: Compared to culture in the BacT/ALERT system, the PCR assay had a sensitivity of 100 percent and a specificity of 100 percent. This real‐time PCR assay has a much shorter turnaround time of 4 hours, which offers the possibility to test and obtain results on PCs before release or the day they are transfused. This would permit the withdrawal of contaminated PCs before transfusion.
Pilot Study: Noninvasive Monitoring of Oral Flecainide's Effects on Atrial Electrophysiology during Persistent Human Atrial Fibrillation Using the Surface Electrocardiogram
Authors: Husser Daniela , Binias Karl‐Heinz , Stridh Martin , Sornmo Leif , Olsson S. Bertil , Molling Jochen , Geller Christoph , Klein Helmut U. , Bollmann Andreas
Published: April 2005

Background: The relation between flecainide's plasma level and its influence on human atrial electrophysiology during acute and maintenance therapy of atrial fibrillation (AF) is unknown. Therefore, this study determined flecainide plasma levels and atrial fibrillatory rate obtained from the surface ECG during initiation and early maintenance of oral flecainide in patients with persistent lone AF and assessed their relationship.

Methods and Results: In 10 patients (5 males, mean age 63 ± 14 years, left atrial diameter 46 ± 3 mm) with persistent lone AF, flecainide was administered as a single oral bolus (day 1) followed by 200–400 mg/day (days 2–5). The initial 300 mg flecainide bolus resulted in therapeutic plasma levels in all patients (range 288–629 ng/ml) with no side effects. Flecainide plasma levels increased on day 3 and remained stable thereafter. Day 5 plasma levels were lower (508 ± 135 vs 974 ± 276 ng/ml, P = 0.009) in patients with daily mean flecainide doses of 200 mg compared to patients with higher maintenance doses. Fibrillatory rate obtained from the surface electrocardiogram measuring 378 ± 17 fpm at baseline was reduced to 270 ± 18 fpm (P < 0.001) after the flecainide bolus but remained stable thereafter. Fibrillatory rate reduction was independent of flecainide plasma levels or clinical variables.

Conclusion: A 300 mg oral flecainide bolus is associated with electrophysiologic effects that are not increased during early maintenance therapy in persistent human lone AF. In contrast to drug plasma levels, serial analysis of fibrillatory rate allows monitoring of individual drug effects on atrial electrophysiology.
Abiotic induction of susceptibility in insect‐resistant willow
Authors: Höglund Solveig , Larsson Stig
Published: April 2005

Plants are mosaics of resource quality to insect herbivores. Some leaves are superior to others, resulting in variable insect performance. Certain Salix viminalis L. (Salicaceae) genotypes show an unusually strong resistance to the gall midge Dasineura marginemtorquens Bremi (Diptera: Cecidomyiidae). A few leaves are frequently galled on such resistant willows, whereas on the great majority of leaves all larvae die before any galls are formed. We performed a series of greenhouse and field experiments in order to understand in more detail the observed intraplant heterogeneity. First, we tested whether random events (biotic or abiotic) can induce a susceptibility that is expressed later (next season), i.e., delayed induced susceptibility. Second, we performed a combined field and greenhouse experiment to test the possibility that susceptibility was induced by abiotic factors at the time of gall induction (within days), i.e., rapid induced susceptibility. We found support for rapid induced susceptibility, but not for delayed induced susceptibility. Although resistance remained strong, significantly more leaves with surviving larvae and galls were found on potted plants moved to the field compared with identical plants that remained in the greenhouse. Potted field plants were exposed to field conditions during a very short period in connection with gall initiation. Thus, we can exclude soil moisture, nutrient availability, and the history of the plant as factors explaining the induction of susceptibility. We tentatively suggest that radiation interferes with the expression of resistance. Our findings suggest that plasticity in plant resistance may be linked to ambient light conditions, and that heterogeneity in leaf suitability can be of ecological significance in plants that are considered resistant.
Influence of leaf trichome density on the efficiency of two polyphagous insect predators
Authors: Björkman Christer , Ahrné Karin
Published: April 2005

Plant characteristics, such as leaf structure or hairiness, are important for the movement and attachment of insects. It has been suggested that increased trichome density on new Salix cinerea L. (Salicaceae) leaves, produced after grazing by the willow leaf beetle Phratora vulgatissima L. (Coleoptera: Chrysomelidae), function as an inducible defence against the beetle and especially its larvae. Here we studied whether and how two of the main natural enemies of P. vulgatissima, viz., Anthocoris nemorum L. (Heteroptera: Anthocoridae) and Ortothylus marginalis L. (Heteroptera: Miridae), were influenced by trichome density on S. cinerea leaves. The effect of trichome density on these two predators was studied on plants with different trichome densities, comparing natural enemy efficiency, measured as number of P. vulgatissima eggs consumed or larvae missing and/or killed. To obtain different trichome densities, cuttings of several different clones of S. cinerea were used. In the experiment using eggs as prey, an increase in trichome density was, in addition, induced through leaf beetle defoliation on half of the plants of each willow clone. Furthermore, a field study was performed to investigate whether trichome density was correlated with natural enemy abundance. The results indicate that neither the efficiency of these two natural enemies in the greenhouse, nor their abundance in the field was influenced by trichome density. A well‐known behavioural difference between the two predator species could probably account for the higher disappearance of larvae after exposure to the more active predator. These findings are relevant for the development of pest management programs, not least because the enemies are polyphagous predators. It is concluded that an induced increase in leaf hairiness in willows in response to leaf beetle grazing could be a plant resistance trait worthy of further study in this system, because no negative effects on the main natural enemies were observed.
Inheritance and plasticity of adult host acceptance in Yponomeuta species: implications for host shifts in specialist herbivores
Authors: Hora Katja H. , Roessingh Peter , Menken Steph B.J.
Published: April 2005

Changes in host acceptance is an important factor in the host specialization of phytophagous insects, and knowledge of the genetic organization of this behaviour is necessary in order to understand how host shifts occur. Here we describe the inheritance of adult host acceptance (oviposition) in three closely related species of Yponomeuta Latreille (Lepidoptera: Yponomeutidae), and their interspecific hybrids. Yponomeuta cagnagellus (Hübner), a specialist on Euonymus europaeus L. (Celastraceae), Y. malinellus Zeller, a specialist on Malus spp. (Rosaceae), and Y. padellus (L.), oligophagous on a number of Rosaceae, were tested for their acceptance of parental hosts in choice tests. Acceptance of E. europaeus is semi‐dominant in hybrids of Y. cagnagellus×Y. padellus, and in hybrids of Y. cagnagellus×Y. malinellus. The dominance of this acceptance was confirmed in oviposition tests with backcross hybrids: backcross hybrids F1 × Y. cagnagellus oviposited mainly on E. europaeus and F1 × Y. padellus still deposited more than half of their egg masses on E. europaeus. Reciprocal hybrids did not differ in their host acceptance, indicating that the trait is autosomal. We further studied the effect of larval food on adult host acceptance (‘Hopkins host selection principle’) in split full‐sib F1 families. Larval diet influenced oviposition only in one of two hybrid crosses. The F1 hybrid of Y. padellus× Y. cagnagellus, reared on Prunus spinosa L., deposited a significantly lower percentage of egg masses on E. europaeus compared to their full‐sib sisters fed with E. europaeus. We did not find this in the reciprocal cross. However, still more than half of the egg masses are deposited on E. europaeus by hybrids that have no experience on this host. We conclude that the semi‐dominant character of acceptance of E. europaeus and a tendency of Rosaceae‐feeding Yponomeuta to deposit egg masses on this host may have created the opportunity for the host shift of the predecessor of Y. cagnagellus from Rosaceae to the Celastraceae. This shift may have been further facilitated by a weak tendency of adults to oviposit on their larval food source.
The Canadian Keiretsu
Authors: Buckley F.H.
Published: April 2005

This article describes the Canadian keiretsu, in which a main Chartered Bank dominates an interlocking group of corporate clients, investment dealers, trust companies, and professional advisors. Such a network facilitates information‐sharing and monitoring among group members, while also reducing the agency costs of banker misbehavior. Most major Canadian firms are members of a keiretsu, and stock ownership of Canadian corporations is far more concentrated than ownership of U.S. companies.

Given their many similarities of history, law, and geography, Canada and the United States should have ended up with similar corporate ownership and governance structures. But they did not, and the difference was Canada's less restrictive banking and bankruptcy laws, which in turn can be traced to Canada's distinctly non‐populist historical experience.

The Canadian keiretsu arose primarily for two reasons: (1) the larger concentration of commercial banking (the six largest Canadian banks today account for 98% of the industry's assets) allowed by Canadian law; and (2) the greater powers of Canadian secured lenders in the event of default. Unlike a U.S. Chapter 11 filing, in a Canadian bankruptcy the lender's right to assume control of the assets was not stayed until quite recently. And, even with the recent change in Canadian bankruptcy law, Canadian secured lenders have much stronger protection of their claims in bankruptcy than their U.S. counterparts in Chapter 11.
SECONDARY MARKET STABILIZATION OF IPOs
Authors: Wilhelm William J.
Published: April 2005

Underwriting syndicates routinely “stabilize” the secondary market price for poorly received initial public offerings. Price stabilization practices, particularly the use of “penalty bids” aimed at discouraging immediate resale or “flipping” of IPO shares, recently have triggered litigation and attracted the attention of the regulatory community. Much of the attention has focused on the allegation that a disproportionate share of the burden of price stabilization efforts is borne by individual investors.

After describing the various practices that fall under the rubric of price stabilization, this article provides several economic rationales for what is by definition a manipulative but legal practice. It also summarizes recently published evidence characterizing the winners and losers from price stabilization and presents a number of conclusions from a recent roundtable discussion among practitioners, regulators, and academics held at the Boston College Carroll School of Management that might serve as a guide to policymakers.
HOW CHANGES IN BOND CALL FEATURES AFFECT COUPON RATES
Authors: Stanhouse Bryan , Stock Duane
Published: April 2005

In April 1998, Level 3, a telecommunications company, sold $2 billion of 9.19%, ten‐year bonds to finance the building of a fiber‐optic network. Like most below‐investment‐grade issues, as well as many investment‐grade issues, the Level 3 issue contained an embedded call option that gave the company the right to repurchase the bonds after five years at par value plus the (semi‐annual) coupon rate, with the call price declining to par two years before maturity.

Because issuers must pay for the call provision in the form of a higher coupon rate, the choice of whether or not to include a call option can be a difficult one. And, once management decides to include a call option, it must then decide how to structure the call. The most important call structure decisions are how long to make the call protection period and how to set the call price—both of which can have a significant impact upon the coupon yields required to attract investors. Using a well‐known option pricing model, the authors of this article summarize their recent research on how variations in bond call features can be expected to affect par coupon yields of new issues under different market circumstances—circumstances that include market conditions relevant to option valuation such as the shape of the term structure and the volatility of interest rates.
High intensity exercise increases expression of matrix metalloproteinases in fast skeletal muscle fibres
Authors: Carmeli Eli , Moas Miri , Lennon Shannon , Powers Scott K.
Published: April 2005

Metalloproteinases (MMPs) are proteolytic enzymes that function in the extracellular matrix to degrade connective tissues. While it is clear that exercise‐induced injury in skeletal muscle promotes increased expression of MMPs, the relationship between exercise intensity and expression of MMPs in muscles is unknown. These experiments tested the hypothesis that exercise‐induced expression of matrix metalloproteinases (MMP‐2 and MMP‐9) is dose‐dependent such that high‐intensity endurance exercise increases MMP expression whereas low‐intensity endurance exercise will not promote MMP expression in skeletal muscles. Female rats (4 months old) completed 2 weeks of treadmill running at either low (18 m min−1; ∼50% maximum oxygen consumption rate

) or high intensity (32 m min−1; ∼70%

; up to 50 min day−1). Non‐running, sedentary animals served as controls. Muscle mRNA and protein levels of MMP‐2 and MMP‐9 were assessed in gastrocnemius, quadriceps and soleus muscles by reverse transcriptase‐polymerase chain reaction and Western blotting, respectively. Results indicate that exercise did not alter MMP‐9 in any of these skeletal muscles. Further, our data reveal that low‐intensity exercise did not alter the expression of MMP‐2 in any of the muscles investigated. In contrast, high‐intensity exercise increased both mRNA and protein levels of MMP‐2 in skeletal muscles containing a high percentage of fast type II fibres (i.e. gastronemius and superficial quadriceps). These results support the hypothesis that high‐intensity exercise is required to promote the expression of MMP‐2 in skeletal muscles and that the influence of exercise on MMP‐2 expression is dominant in muscles containing a high percentage of fast fibres.
Inhibition of carbachol‐evoked oscillatory currents by the NO donor sodium nitroprusside in guinea‐pig ileal myocytes
Authors: Chung Seung‐Soo , Ahn Duck‐Sun , Lee Hong‐Ghi , Lee Young‐Ho , Nam Taick‐Sang
Published: April 2005

The effect of sodium nitroprusside (SNP) on carbachol (CCh)‐evoked inward cationic current (Icat) oscillations in guinea‐pig ileal longitudinal myocytes was investigated using the whole‐cell patch‐clamp technique and permeabilized longitudinal muscle strips. SNP (10 μm) completely inhibited Icat oscillations evoked by 1 μm CCh. 1H‐(1,2,4) Oxadiazole [4,3‐a] quinoxaline‐1‐one (ODQ; 1 μm) almost completely prevented the inhibitory effect of SNP on Icat oscillations. 8‐Bromo‐guanosine 3′,5′‐cyclic monophosphate (8‐Br‐cGMP; 30 μm) in the pipette solution completely abolished Icat oscillations. However, a pipette solution containing Rp‐8‐Br‐cGMP (30 μm) almost completely abolished the inhibitory effect of SNP on Icat oscillations. When the intracellular calcium concentration ([Ca2+]i) was held at a resting level using BAPTA (10 mm) and Ca2+ (4.6 μm) in the pipette solution, CCh (1 μm) evoked only the sustained component of Icat without any oscillations and SNP did not affect the current. A high concentration of inositol 1,4,5‐trisphosphate (IP3; 30 μm) in the patch pipette solutions significantly reduced the inhibitory effect of SNP (10 μm) on Icat oscillations. SNP significantly inhibited the Ca2+ release evoked by either CCh or IP3 but not by caffeine in permeabilized preparations of longitudinal muscle strips. These results suggest that the inhibitory effects of SNP on Icat oscillations are mediated, in part, by functional modulation of the IP3 receptor, and not by the inhibition of cationic channels themselves or by muscarinic receptors in the plasma membrane. This inhibition seems to be mediated by an increased cGMP concentration in a protein kinase G‐dependent manner.
Depolarization pattern of ventricular epicardium in two‐kidney one‐clip hypertensive rats
Authors: Kharin Sergey N. , Krandycheva Valeria V. , Shmakov Dmitry N.
Published: April 2005

The present study is the first attempt to examine the effect of left ventricular hypertrophy (LVH) on the excitation pattern of the ventricular epicardium in experimental hypertensive rats. The left renal artery was clipped in Wistar rats (n= 8; 6–8 months old; weight, 174–295 g) to produce two‐kidney one‐clip (2K1C) hypertension. After 4 weeks, blood pressure was measured, and epicardial potential mapping was performed under sinus rhythm from 64 unipolar electrodes regularly distributed over the ventricular epicardium. Systolic blood pressure was ∼40% higher in the rats with a clipped renal artery (162 ± 14 mmHg, mean ±s.d.) than in the normotensive rats (115 ± 3 mmHg). LVH (∼23% increase in the ratio of the left ventricular weight to the body weight, P < 0.05) was observed in the 2K1C hypertensive rats. The depolarization pattern of the ventricular epicardium in the normotensive rats was similar to that in the rats with 2K1C hypertensive LVH. The duration of ventricular epicardial activation was shown to increase (∼35%, P < 0.05) in the hypertensive rats as compared to the normotensive animals. This study provides an explanation for alterations of the body surface potential distribution in hypertensive patients with LVH.
Body maintenance and repair: how food and exercise keep the musculoskeletal system in good shape
Authors: Rennie Michael J.
Published: April 2005

This article provides a personal view of how feeding and exercise acutely modify protein metabolism of human skeletal muscle, with discussion of the anabolic signalling mechanisms involved and some new findings on the metabolism of the turnover of collagen, tendon and bone.
Influence of elevated renin substrate on angiotensin II and arterial blood pressure in conscious mice
Authors: Cholewa Brian C. , Mattson David L.
Published: April 2005

The present experiments were performed to determine the influence of intravenous administration of renin substrate on plasma angiotensin II levels and mean arterial blood pressure in conscious C57BL/6J mice. Mice with chronic indwelling femoral arterial and venous catheters were acutely or chronically administered intravenous doses of a synthetic peptide corresponding to the 14 amino acids on the N‐terminal of angiotensinogen. A dose‐dependent increase in arterial blood pressure was observed as the intravenous bolus dose of the renin substrate was increased from 0.18 to 180 nmol kg−1 with a maximal increase in pressure of 40 ± 3 mmHg achieved following administration of the 18 nmol kg−1 bolus (n= 11). Additional experiments demonstrated that a sustained intravenous infusion of the renin substrate led to a long‐term increase in arterial blood pressure. The continuous infusion of renin substrate at 0.05 nmol kg−1 min−1 for 3 days did not alter arterial blood pressure from the control level of 119 ± 5 mmHg (n= 5); however, arterial blood pressure significantly increased to 129 ± 6 mmHg with an infusion rate of 0.5 nmol kg−1 min−1 and further increased to 141 ± 3 mmHg when the renin substrate infusion was increased to 5.0 nmol kg−1 min−1. Finally, the infusion of renin substrate at 5.0 nmol kg−1 min−1 resulted in a significant increase in plasma angiotensin II concentration from 34 ± 6 pg ml−1 in vehicle‐infused mice to 288 ± 109 pg ml−1. These results demonstrate that modulation of the circulating level of angiotensinogen can alter the plasma angiotensin II level and arterial blood pressure in normal animals.
Alterations in mouse cardiac proteome after in vivo myocardial infarction: permanent ischaemia versus ischaemia–reperfusion
Authors: De Celle Tijl , Vanrobaeys Frank , Lijnen Peter , Blankesteijn W. Matthijs , Heeneman Sylvia , Van Beeumen Jozef , Devreese Bart , Smits Jos F. M. , Janssen Ben J. A.
Published: April 2005

Mice are increasingly used to study the early molecular mechanisms inducing injury to the heart following myocardial infarction. To date, two‐dimensional gel electrophoresis combined with mass spectrometry has not been applied to identify changes in protein expression in myocardial tissue of mice subjected in vivo to permanent ischaemia (PI) or ischaemia–reperfusion (IR). In the PI group, ischaemia was induced for 210 min by ligation of the left anterior descending coronary artery while in the IR group, ischaemia was maintained for 30 min and reperfusion was allowed for 180 min. In both groups, the area of the left ventricle at risk was processed for 2‐dimensional gel electrophoresis. By comparing protein density changes in cytosolic as well as membrane fractions, we found a total of 32 protein spots that were differentially expressed. Twenty spots changed in expression level after PI alone, four spots after IR alone, and eight spots changed in both models. Identified proteins with MALDI TOF‐TOF and LC‐MS/MS can be classified into functional groups of anticoagulant proteins, structural proteins, inflammatory‐related proteins, transcription‐ and translation‐related proteins, heat shock proteins (HSPs), metabolism‐related proteins and miscellaneous. A remarkable finding was the IR‐specific translocation of annexins (A3 and A5) from the cytosolic to the membrane compartment, a phenomenon that was verified by Western blotting. Four proteins were changed in expression level at multiple spot locations, characterized by a difference in isoelectric point. In the case of cardiac troponin T and HSP‐20, these changes were also dependent on the model. In addition, one spot for the proteins adenylate kinase 1, cardiac troponin T and HSP‐20 was uniquely present in the IR and/or PI groups and not in the respective sham groups. The specific alterations in protein expression that took place after PI and IR may stimulate the search for new tools to diagnoze myocardial infarction and to characterize specific pathology‐related changes in protein expression.
Reliability of orthostatic responses in healthy men aged between 65 and 75 years
Authors: Gabbett Tim J. , Gass Greg C.
Published: April 2005

The purpose of this study was to investigate the short‐, medium‐ and long‐term reproducibility of cardiovascular responses during 90° head‐up tilt (HUT) in healthy older men. Twenty‐eight healthy male subjects aged 69 (95% confidence intervals, 68–70) years participated in the study. Eight subjects underwent duplicate 90° HUT tests on consecutive days, while 20 subjects underwent four 90° HUT tests performed at baseline, and after 1 week, 1 month and 1 year. Following a 20‐min supine resting period, each subject was rapidly tilted to the upright vertical position (90° HUT) and remained in that position for 15 min. Beat‐by‐beat recordings of mean (MAP), systolic (SBP) and diastolic (DBP) pressures were made via Finapres, while heart rate (HR) was monitored continuously from an electrocardiogram. No significant test–retest differences (P > 0.05) were observed for the changes in HR, MAP, SBP or DBP during 90° HUT. These measurements demonstrated high reproducibility (intraclass correlation coefficient, r= 0.91–0.99, P < 0.05). The supine resting and tilted HR, MAP, SBP and DBP over the 1‐week, 1‐month and 1‐year period were not significantly different (P > 0.05) from baseline, and demonstrated high reproducibility (intraclass correlation coefficient, r= 0.82–0.98, P < 0.05). The results of this study demonstrate that in healthy older men, cardiovascular responses during orthostasis are highly reproducible, and this reproducibility is maintained over a 12‐month period. These findings demonstrate that the 90° HUT test offers a reproducible method of monitoring longitudinal orthostatic responses in healthy older men.
Musculoskeletal Modeling and Dynamic Simulation of the Thoroughbred Equine Forelimb During Stance Phase of the Gallop
Authors: Swanstrom Michael D. , Zarucco Laura , Hubbard Mont , Stover Susan M. , Hawkins David A.
Published: April 2005

Because thoroughbred racehorses have a high incidence of forelimb musculoskeletal injuries, a model was desired to screen potential risk factors for injuries. This paper describes the development of a musculoskeletal model of the thoroughbred forelimb and a dynamic simulation of the motion of the distal segments during the stance phase of high-speed (18m∕s) gallop. The musculoskeletal model is comprised of segment, joint, muscle-tendon, and ligament information. The dynamic simulation incorporates a proximal forward-driving force, a distal ground reaction force model, muscle activations, and initial positions and velocities. A simulation of the gallop after transection of an accessory ligament demonstrated increased soft tissue strains in the remaining support structures of the distal forelimb. These data were consistent with those previously reported from in vitro experimental data and supported usefulness of the model for the study of distal forelimb soft tissue mechanics during the stance phase of the gallop.
Outer Membrane Protein P6 of NontypeableHaemophilus influenzaeIs a Potent and Selective Inducer of Human Macrophage Proinflammatory Cytokines
Authors: Berenson Charles S. , Murphy Timothy F. , Wrona Catherine T. , Sethi Sanjay
Published: April 2005

Interactions of nontypeableHaemophilus influenzae(NTHI) with human macrophages contribute to the pathogenesis of NTHI-induced infection in humans. However, the immunologic mechanisms that initiate and perpetuate NTHI-mediated macrophage responses have not been well explored. Outer membrane protein (OMP) P6 is a conserved lipoprotein expressed by NTHI in vivo that possesses a Pam3Cys terminal motif, characteristic of immunoactive bacterial lipoproteins associated with Toll-like receptor signaling. We theorized that OMP P6 is a potent immunomodulator of human macrophages. To test this hypothesis, we purified OMP P6 as well as OMP P2, the predominant NTHI outer membrane protein, and lipooligosaccharide (LOS), the specific endotoxin of NTHI, from NTHI strain 1479. Human blood monocyte-derived macrophages, purified from healthy donors, were incubated with each outer membrane constituent, and cytokine production of macrophage supernatants interleukin-1β (IL-1β), tumor necrosis factor α (TNF-α), IL-10, IL-12, and IL-8 was measured. OMP P6 selectively upregulated IL-10, TNF-α, and IL-8. While OMP P6 (0.1 μg/ml for 8 h) elicited slightly greater concentrations of IL-10, it resulted in over ninefold greater concentrations of TNF-α and over fourfold greater concentrations of IL-8 than did OMP P2. OMP P6 at doses as low as 10 pg/ml was still effective at induction of macrophage IL-8, while OMP P2 and LOS were not. OMP P6 of NTHI is a specific trigger of bacteria-induced human macrophage inflammatory events, with IL-8 and TNF-α as key effectors of P6-induced macrophage responses.
Candida albicans-Secreted Aspartic Proteinases Modify the Epithelial Cytokine Response in an In Vitro Model of Vaginal Candidiasis
Authors: Schaller Martin , Korting Hans C. , Borelli Claudia , Hamm Gerald , Hube Bernhard
Published: April 2005

Secreted aspartyl proteinases (Saps) are important virulence factors ofCandida albicansduring mucosal and disseminated infections and may also contribute to the induction of an inflammatory host immune response. We used a model of vaginal candidiasis based on reconstituted human vaginal epithelium (RHVE) to study the epithelial cytokine response induced byC. albicans. In order to study the impact of the overall proteolytic activity and of distinct Sap isoenzymes, we studied the effect of the proteinase inhibitor pepstatin A on the immune response and compared the cytokine expression pattern induced by the wild-type strain SC5314 with the pattern induced by Sap-deficient mutants. Infection of RHVE with theC. albicanswild-type strain induced strong interleukin 1α (IL-1α), IL-1β, IL-6, IL-8, IL-10, granulocyte-macrophage colony-stimulating factor, gamma interferon, and tumor necrosis factor alpha responses in comparison with cytokine expression in noninfected tissue. Addition of the aspartyl proteinase inhibitor pepstatin A strongly reduced the cytokine response of RHVE. Furthermore,SAP-null mutants lacking eitherSAP1orSAP2caused reduced tissue damage and had a significantly reduced potential to stimulate cytokine expression. In contrast, the vaginopathic and cytokine-inducing potential of mutants lackingSAP4toSAP6was similar to that of the wild-type strain. These data show that the potential of specific Saps to cause tissue damage correlates with an epithelium-induced proinflammatory cytokine response, which may be crucial in controlling and managingC. albicansinfections at the vaginal mucosa in vivo.
Gamma Irradiation or CD4+-T-Cell Depletion Causes Reactivation of LatentSalmonella entericaSerovar Typhimurium Infection in C3H/HeN Mice
Authors: van Diepen Angela , van de Gevel Joke S. , Koudijs Margaretha M. , Ossendorp Ferry , Beekhuizen Henry , Janssen Riny , van Dissel Jaap T.
Published: April 2005

Upon infection withSalmonella, a host develops an immune response to limit bacterial growth and kill and eliminate the pathogen.Salmonellahas evolved mechanisms to remain dormant within the body, only to reappear (reactivate) at a later time when the immune system is abated. We have developed an in vivo model for studying reactivation ofSalmonella entericaserovar Typhimuriuminfection in mice. Upon subcutaneous infection, C3H/HeN (Ityr) mice showed an increase in bacterial numbers in livers and spleens, which reached a peak on day 19. After full recovery from the infection, these mice were irradiated or depleted of CD4+T cells. The mice displayed a secondary infection peak in livers and spleens with a course similar to that of the primary infection. We concluded that CD4+T cells are involved in active suppression ofS. entericaserovar Typhimurium during latency. The role of CD4+T cells during primary infection withS. entericaserovar Typhimurium is well established. This is the first study to describe a role of CD4+T cells during the latent phase ofS. entericaserovar Typhimurium infection.
Induction ofMycobacterium tuberculosis-Specific Primary and Secondary T-Cell Responses in Interleukin-15-Deficient Mice
Authors: Lazarevic Vanja , Yankura David J. , Divito Sherrie J. , Flynn JoAnne L.
Published: April 2005

Several studies have provided evidence that interleukin-15 (IL-15) can enhance protective immune responses againstMycobacterium tuberculosisinfection. However, the effects of IL-15 deficiency on the functionality ofM. tuberculosis-specific CD4 and CD8 T cells are unknown. In this study, we investigated the generation and maintenance of effector and memory T-cell responses followingM. tuberculosisinfection of IL-15−/−mice. IL-15−/−mice had slightly higher bacterial numbers during chronic infection, which were accompanied by an increase in gamma interferon (IFN-γ)-producing CD4 and CD8 T cells. There was no evidence of increased apoptosis or a defect in proliferation of CD8 effector T cells followingM. tuberculosisinfection. The induction of cytotoxic and IFN-γ CD8 T-cell responses was normal in the absence of IL-15 signaling. The infiltration of CD4 and CD8 T cells into the lungs of “immune” IL-15−/−mice was delayed in response toM. tuberculosischallenge. These findings demonstrate that efficient effector CD4 and CD8 T cells can be developed followingM. tuberculosisinfection in the absence of IL-15 but that recall T-cell responses may be impaired.
Induction of Strain-Transcending Immunity againstPlasmodium chabaudi adamiMalaria with a Multiepitope DNA Vaccine
Authors: Scorza T. , Grubb K. , Smooker P. , Rainczuk A. , Proll D. , Spithill T. W.
Published: April 2005

A major goal of current malaria vaccine programs is to develop multivalent vaccines that will protect humans against the many heterologous malaria strains that circulate in endemic areas. We describe a multiepitope DNA vaccine, derived from a genomicPlasmodium chabaudi adamiDS DNA expression library of 30,000 plasmids, which induces strain-transcending immunity in mice against challenge withP. c. adamiDK. Segregation of this library and DNA sequence analysis identified vaccine subpools encoding open reading frames (ORFs)/peptides of >9 amino acids [aa] (the V9+ pool, 303 plasmids) and >50 aa (V50+ pool, 56 plasmids), respectively. The V9+ and V50+ plasmid vaccine subpools significantly cross-protected mice against heterologousP. c. adamiDK challenge, and protection correlated with the induction of both specific gamma interferon production by splenic cells and opsonizing antibodies. Bioinformatic analysis showed that 22 of the V50+ ORFs were polypeptides conserved among three or morePlasmodiumspp., 13 of which are predicted hypothetical proteins. Twenty-nine of these ORFs are orthologues of predictedPlasmodium falciparumsequences known to be expressed in the blood stage, suggesting that this vaccine pool encodes multiple blood-stage antigens. The results have implications for malaria vaccine design by providing proof-of-principle that significant strain-transcending immunity can be induced using multiepitope blood-stage DNA vaccines and suggest that both cellular responses and opsonizing antibodies are necessary for optimal protection againstP. c. adami.
Invasion of an estuarine transition zone by Dreissena polymorpha veligers had no detectable effect on zooplankton community structure
Authors: Winkler Gesche , Sirois Pascal , Johnson Ladd E , Dodson Julian J
Published: April 2005

Large numbers of the filter-feeding larval stage of zebra mussels (Dreissena polymorpha) (veligers) have been advected into the estuarine transition zone (ETZ) of the St. Lawrence River. In 1994, they became the dominant member of the tidal freshwater zooplankton assemblage of the ETZ (and subsequently the true estuarine assemblage) during summer months. These changes in community structure have not, however, been reflected in changes in the abundance of preinvasion taxa. Abundance of potential planktonic competitors such as rotifers and the cladoceran Bosmina longirostris fluctuated between years but did not decline following the invasion. Only densities of the copepod Eurytemora affinis declined in 2000 and 2001, but this could not be definitively associated with the invasion. Synchronous variation among different zooplankton groups suggests that environmental forcing related to or correlated with temperature anomalies is the major cause of interannual variation in the abundance of zooplankton taxa. The negative correlation between veliger abundance and salinity indicates that the ETZ acts as a sink for the larval stages of the zebra mussel. Their precise fate remains uncertain, but our study suggests that this invasion has had little or no impact on this pelagic community in spite of the numerical dominance of veligers.
Differential isotopic enrichment and half-life among tissues in Japanese temperate bass (Lateolabrax japonicus) juveniles: implications for analyzing migration
Authors: Suzuki Keita W , Kasai Akihide , Nakayama Kouji , Tanaka Masaru
Published: April 2005

As a first step for field applications of stable isotope techniques to investigate the migration of Japanese temperate bass (Lateolabrax japonicus) (Perciformes) juveniles, we conducted a diet switch experiment and fitted an exponential model to changes in stable carbon (δ13C) and nitrogen (δ15N) isotope ratios for muscle, fin, and liver. The trophic enrichment values were ranked liver < muscle < fin for δ13C (range 0.80 to +3.66) and liver < fin < muscle for δ15N (+0.59 to +3.12). The half-life values were similar for muscle and fin for both δ13C and δ15N (19.325.7 days), while those for liver were 5.3 days for δ13C and 14.4 days for δ15N. Both the δ13C and δ15N values of muscle reached the asymptotic value after a threefold body weight increase, reflecting the diet after the switch. These results suggest that fin is a useful substitute for muscle in field applications of stable isotope techniques and that liver, with a shorter half-life, has the potential to provide more recent information about migration.
Overproduction and characterization of xylanase B fromAspergillus niger
Authors: Levasseur Anthony , Asther Marcel , Record Eric
Published: April 2005

The xynB gene, which encodes endo-β-1,4-xylanase XynB, in Aspergillus niger BRFM281 was amplified by RT-PCR using mRNA isolated from a culture containing sugar beet pulp as an inducer. The cDNA was cloned into an expression cassette under the control of the strong and constitutive glyceraldhehyde-3-phosphate dehydrogenase gene promoter. The expression system was designed to produce the recombinant enzyme XynB with a six-histidine peptide fused to the carboxy end of the protein. Homologous overproduction of XynB was successfully achieved in shake flask cultures, and the secretion yield was estimated to be 900 mg·L–1. The recombinant XynB was purified 1.5-fold by immobilized metal affinity chromatography to homogeneity using a one-step purification protocol with 71% recovery. The purified recombinant enzyme was fully characterized and has a molecular mass of 23 kDa and an optimal activity at pH 5.5 and 50 °C with stability in the pH range 4.0-7.0 and temperature up to 50 °C. Using soluble oat spelts xylan, the determined Kmand Vmaxvalues were 7.1 mg·mL–1and 3881 U·mg–1, respectively.Key words: homologous expression, glycoside hydrolase family 11, cell-wall degradation.
Intrastrain internal transcribed spacer heterogeneity inGanodermaspecies
Authors: Wang D -M , Yao Y -J
Published: April 2005

Intrastrain internal transcribed spacer (ITS) heterogeneity is first reported from Ganoderma, a fungal genus within Basidiomycetes. ITS amplification products from 4 strains, representing 4 Ganoderma species, were cloned and sequenced. Two to five different ITS types were found within a single strain. The clone sequences were analyzed along with other sequences from Ganoderma retrieved from GenBank. The results show that sequence variation within strains varies considerably with species and the heterogeneity may occur in the 3 parts (ITS1, ITS2, and 5.8S) of the ITS region.Key words: intragenomic ITS heterogeneity, polymorphism, Ganoderma.
Environmental factors affecting reproduction and development in ascidians and other protochordates
Authors: Bates William R
Published: April 2005

Protochordate reproduction and development are influenced by many kinds of environmental factors. For example, spawning, sexual and asexual reproduction, larval behaviour, and life-cycle transitions (metamorphosis) are key processes known to be affected by environmental factors. This review must be restricted primarily to only one group of protochordates, the ascidians or "sea squirts", because information on the reproductive ecology of hemichordates and cephalochordates is limited to only a few studies. Topics discussed in the present review include (i) environmental factors that regulate larval settlement, (ii) how pelagic embryos avoid damage to DNA caused by UV radiation, (iii) the effect of water temperature and food availability on sexual reproduction in colonial ascidians, (iv) environmental regulation of asexual budding, (v) environmental regulation of metamorphosis, and (vi) the possible role of the environment in the evolution of direct-developing ascidians. A novel role for HSP90 and nitric oxide signaling in the integration of environmental factors with cell signaling pathways in ascidians is discussed near the end of this review. Throughout this review, the multiple roles of environmental stress on ascidian reproduction and development are emphasized.
ON ASTUMIAN'S PARADOX
Authors: BEHRENDS EHRHARD
Published: April 2005

An Astumian game is defined by a finite Markov chain with state space S with precisely two absorbing states, the winning and the losing state. The other states are transient, one of them is the starting position. The game is said to be losing (respectively fair respectively winning) if the probability to be absorbed at the winning state is smaller than 0.5 (respectively = 0.5 respectively larger than 0.5). Astumian's paradox states that there are losing games on the same state space S a stochastic mixture of which is winning. (By "stochastic mixture" we mean that in each step one decides with the help of a fair coin whether to use the transition probabilities of the first or the second game.)

Most of our results concern fair games. Mixtures are systematically investigated. Rather surprisingly, the winning probability of the mixture of fair games can be arbitrarily close to zero (or to one). Even more counter-intuitive are examples of definitely losing games (this means that the winning probability is exactly zero) such that the winning probability of the mixture is arbitrarily close to one. We show, however, that such extreme examples are possible only if one tolerates huge running times of the game.

As a natural generalization one can also consider arbitrary mixtures: the fair coin is replaced by a biased one, with probability λ respectively 1-λ one plays with the first respectively the second game. It turns out that fair games exist such that — depending on the choice of λ — the λ-mixture can be fair, losing or winning.
EXTENDED ENTROPIES AND DISORDER
Authors: DAVISON MATT , SHINER J. S.
Published: April 2005

Landsberg's notion of disorder, entropy normalized to maximum entropy, was originally proposed for the Shannon information-theoretic entropy to overcome extensivity-based deficiencies of entropy as a measure of disorder. We generalize Landsberg's concept to three classes of extended entropies: Rényi, Tsallis and Landsberg–Vedral. We show an intimate connection between the Rényi disorders and the spectrum of dimensions known as multifractals. Three examples are treated, including one for power law distributions and one based on the logistic map. On the basis of the three examples, it is demonstrated that all three classes of extended disorder are required to fully characterize the corresponding properties of a system. We conjecture, and sketch a proof to support, that all three extended disorders are also sufficient to completely determine a dimension spectrum.
Coming of Age: Law and Society Enters an Exclusive Club
Authors: Friedman Lawrence M.
Published: April 2005

▪ Abstract  Law and society, though not a field in itself, is the object of a growing movement that studies legal systems using tools of social science. Founded by sociologists, the movement now includes representatives of all the social sciences. It has developed strong organizations in the United States and in a number of other countries. Its adherents share a number of basic assumptions; they reject extreme ideas of legal autonomy and stress instead the dependence of law on its social context. Key components of the legal order, and thus key objects of study, are substance, procedures, structures, and legal culture. Scholars focus on the actual forces that produce law and on the impact of legal interventions. Sanctions, the peer group, and the internal moral sense are among the factors that determine actual impact. Much has been accomplished in the field, although much remains to be done, and translating findings into policy is often quite problematic.