bluuebunny/crossref_metadata_2025 huggingface dataset:
Randomized Trial of Intravenous Iron Supplementation in Patients With Chemotherapy-Related Anemia Without Iron Deficiency Treated With Darbepoetin Alfa
Authors: Pedrazzoli Paolo , Farris Antonio , Del Prete Salvatore , Del Gaizo Filomena , Ferrari Daris , Bianchessi Clara , Colucci Giuseppe , Desogus Alberto , Gamucci Teresa , Pappalardo Alessandro , Fornarini Giuseppe , Pozzi Paola , Fabi Alessandra , Labianca Roberto , Di Costanzo Francesco , Secondino Simona , Crucitta Enrico , Apolloni Federica , Del Santo Antonio , Siena Salvatore
Published: March 2008

Purpose

Unresponsiveness to erythropoiesis-stimulating agents, occurring in 30% to 50% of patients, is a major limitation to the treatment of chemotherapy-related anemia. We have prospectively evaluated whether intravenous iron can increase the proportion of patients with chemotherapy-related anemia who respond to darbepoetin.

Patients and Methods

Between December 2004 and February 2006, 149 patients with lung, gynecologic, breast, and colorectal cancers and ≥ 12 weeks of planned chemotherapy were enrolled from 33 institutions. Patients were required to have hemoglobin ≤ 11 g/L and no absolute or functional iron deficiency. All patients received darbepoetin 150 μg subcutaneously once weekly for 12 weeks and were randomly assigned to sodium ferric gluconate 125 mg intravenously (IV) weekly for the first 6 weeks (n = 73) or no iron (n = 76). Primary end point of the study was the percentage of patients achieving hematopoietic response (hemoglobin ≥ 12 g/dL or ≥ 2 g/dL increase).

Results

Hematopoietic response by intention-to-treat analysis was 76.7% (95%CI, 65.4% to 85.8%) in the darbepoetin/iron group and 61.8% (95%CI, 50.0% to 72.7%) in the darbepoetin group (P = .0495). Among patients fulfilling eligibility criteria and having received at least four darbepoetin administrations, hematopoietic responses in the darbepoetin/iron group (n = 53) and in the darbepoetin-only group (n = 50) were 92.5% (95% CI, 81.8% to 97.9%) and 70% (95% CI, 55.4% to 82.1%), respectively (P = .0033). Increase of hemoglobin during treatment period showed a time profile favoring darbepoetin/iron with statistically significant effect from week 5 on. The safety profile was comparable in the two arms.

Conclusion

In patients with chemotherapy-related anemia and no iron deficiency, IV iron supplementation significantly reduces treatment failures to darbepoetin without additional toxicity.
Phase I Study of Bevacizumab Added to Fluorouracil- and Hydroxyurea-Based Concomitant Chemoradiotherapy for Poor-Prognosis Head and Neck Cancer
Authors: Seiwert Tanguy Y. , Haraf Daniel J. , Cohen Ezra E.W. , Stenson Kerstin , Witt Mary Ellyn , Dekker Allison , Kocherginsky Masha , Weichselbaum Ralph R. , Chen Helen X. , Vokes Everett E.
Published: March 2008

Purpose

We conducted a phase I dose escalation study to determine the maximum-tolerated dose (MTD) and dose-limiting toxicity (DLT) of bevacizumab, when added to the standard FHX (fluorouracil [FU], hydroxyurea [HU], radiation) chemoradiotherapy platform in poor-prognosis head and neck cancer (HNC) patients.

Patients and Methods

Patients with recurrent, previously radiated or poor-prognosis, treatment-naive HNC were eligible. Treatment was repeated every 14 days for seven cycles: Bevacizumab was escalated 2.5 to 10 mg/kg, FU 600 to 800 mg/m2 (120 hours continuous infusion), and hydroxyurea from 500 to 1,000 mg (twice daily for 5 days), starting day 1. At the MTD, the cohort was expanded.

Results

Forty-three patients were treated. DLT was reached at level 3 (bevacizumab 5 mg/kg, FU 800 mg/m2, HU 1,000 mg) with two grade 3 transaminase elevations and one grade 4 neutropenia, attributed to the combination of chemotherapy with bevacizumab. For level 4, chemotherapy doses were reduced (FU 600 mg/2, HU 500 mg), and bevacizumab escalation continued to 10 mg/kg. Treatment of six assessable patients resulted in one venous thrombosis; this dose level was expanded to 26 patients. Late complications included five patients with fistula formation (11.6%) and four with ulceration/tissue necrosis (9.3%). Serious toxicities (hemorrhage/thrombosis/death) were comparable to prior reirradiation reports. Median overall survival for reirradiated patients with recurrent, nonmetastatic disease was 10.3 months [95% CI, 5.6 to 13.5]; 2-year cumulative incidence of death resulting from disease was 51.7% (95% CI, 31.7 to 68.5).

Conclusion

Bevacizumab can be integrated with FHX chemoradiotherapy at a dose of 10 mg/m2 every 2 weeks with decreased chemotherapy doses because of neutropenia. The regimen shows antitumor activity. Observed fistula formation/tissue necrosis may be bevacizumab related, and further investigation should proceed with careful monitoring.
Estimating maximum performance: effects of intraindividual variation
Authors: Adolph Stephen C. , Pickering Trevor
Published: March 2008

Researchers often estimate the performance capabilities of animals using a small number of trials per individual. This procedure inevitably underestimates maximum performance, but few studies have examined the magnitude of this effect. In this study we explored the effects of intraindividual variation and individual sample size on the estimation of locomotor performance parameters. We measured sprint speed of the lizard Sceloporus occidentalis at two temperatures (20°C and 35°C),obtaining 20 measurements per individual. Speed did not vary temporally,indicating no training or fatigue effects. About 50% of the overall variation in speed at each temperature was due to intraindividual variation. While speed was repeatable, repeatability decreased slightly with increasing separation between trials. Speeds at 20°C and 35°C were positively correlated,indicating repeatability across temperatures as well. We performed statistical sampling experiments in which we randomly drew a subset of each individual's full set of 20 trials. As expected, the sample's maximum speed increased with the number of trials per individual; for example, five trials yielded an estimate averaging 89% of the true maximum. The number of trials also influenced the sample correlation between mean speeds at 20°C and 35°C; for example, five trials yielded a correlation coefficient averaging 90% of the true correlation. Therefore, intraindividual variation caused underestimation of maximal speed and the correlation between speeds across temperatures. These biases declined as the number of trials per individual increased, and depended on the magnitude of intraindividual variation, as illustrated by running sampling experiments that used modified data sets.
A functional analysis of myotomal muscle-fibre reorientation in developing zebrafishDanio rerio
Authors: van Leeuwen Johan L. , van der Meulen Talitha , Schipper Henk , Kranenbarg Sander
Published: March 2008

The fast muscle fibres in the anterior trunk of teleost fish are primarily responsible for large amplitude undulatory swimming motions. Previous theoretical studies suggested that the near-helical arrangement of these fibres results in a (fairly) uniform distribution of fibre strain and work output during swimming. However, the underlying simplifications of these studies precluded unequivocal support for this hypothesis. We studied the fast muscle-fibre reorientation and the concomitant myotomal strain variance in a body segment near the anus during larval and juvenile development in the zebrafish. From 2 to 4 days post fertilization (d.p.f.), the measured angles between the muscle fibres and the longitudinal axis of the zebrafish were small. Yet, onset of a near-helical muscle-fibre arrangement was recognized. Juveniles of 51 d.p.f. have larger mean fibre angles and already possess the near-helical pattern of adult teleosts. We present a model that computes the distribution of the strain along the muscle fibres from measured muscle-fibre orientations, body curvature and prescribed tissue deformations. We selected the most extreme body curvatures, which only occur during fast starts and turning manoeuvres. Using the model, we identified the (non-linear) tissue deformations that yield the least variance in the muscle-fibre strain. We show that simple beam theory cannot reliably predict the strain distribution: it results in very small strains and negligible work output of the most medial fibres. In our model, we avoided these functional limitations by adding a shear deformation to the simple beam deformation. At 2 d.p.f., the predicted variance in the muscle-fibre strain for the shear deformation optimized for strain uniformity is fairly small, due to the small variation in the fibre distances to the medial plane that is caused by the relatively large spinal cord and notochord. The predicted minimal strain variance increases sharply from 2 d.p.f. to 3 d.p.f., remains relatively large at 4 d.p.f., but decreases again considerably at 15 and 39 d.p.f. The 51 d.p.f. stage exhibits the smallest variance in the fibre strains (for the identified optimal deformation), in spite of the widely varying muscle-fibre distances to the medial plane. The non-linear nature of the body deformations with the least strain variance implies an interesting optimization constraint: the juvenile muscle-fibre arrangement results in small predicted spatial strain variations at large-amplitude body curvatures, at the (modest) expense of a large coefficient of variation for small curvatures. We conclude that larval fish rapidly change their muscle-fibre orientations (probably in response to mechanical signals). Within the theoretically examined plausible range of deformations, the closest correspondence to a uniform strain field was found for the juvenile stage.
Mechanics of limb bone loading during terrestrial locomotion in river cooter turtles (Pseudemys concinna)
Authors: Butcher Michael T. , Blob Richard W.
Published: March 2008

Studies of limb bone loading during terrestrial locomotion have focused primarily on birds and mammals. However, data from a broader functional and phylogenetic range of species are critical for understanding the evolution of limb bone function and design. Turtles are an interesting lineage in this context. Although their slow walking speeds and robust limb bones might lead to low locomotor forces and limb bone stresses similar to other non-avian reptiles, their highly sprawled posture could produce high bending loads,leading to high limb bone stresses similar to those of avian and mammalian species, as well as high torsion. To test between these possibilities, we evaluated stresses experienced by the femur of river cooter turtles(Pseudemys concinna) during terrestrial walking by synchronizing measurements of three-dimensional joint kinematics and ground reaction forces(GRFs) during isolated hindlimb footfalls. Further, we evaluated femoral safety factors for this species by comparing our locomotor stress calculations with the results of mechanical property tests. The net GRF magnitude at peak tensile bone stress averaged 0.35 BW (body weight) and was directed nearly vertically for the middle 40–65% of the contact interval, essentially orthogonal to the femur. Peak bending stresses experienced by the femur were low (tensile: 24.9±9.0 MPa; compressive: –31.1±9.1 MPa)and comparable to those in other reptiles, yet peak shear stresses were higher than those in other reptiles, averaging 13.7±4.2 MPa. Such high torsion is present despite cooters lacking a large tail, a feature that has been hypothesized to contribute to torsion in other reptiles in which the tail is dragged along the ground. Comparison of femoral stresses to measurements of limb bone mechanical properties in cooters indicates safety factors to yield of 13.9 in bending and 6.3 in torsion, considerably higher than values typical for birds and mammals, and closer to the elevated values calculated for other reptile species. Thus, not only do turtle limb bones seem considerably`over-designed' for resisting the loads that they encounter, but comparisons of bone loading across tetrapod lineages are consistent with the hypothesis that low limb bone loads, elevated torsion and high safety factors may be primitive features of limb bone design.
Task-dependent force sharing between muscle synergists during locomotion in turkeys
Authors: Nelson Frank E. , Roberts Thomas J.
Published: March 2008

At most joints, there is a redundancy of muscle function. For any given movement, there are a wide range of possible solutions to the problem of how force is shared among muscle synergists. A better understanding of how force is shared among muscle synergists can provide insight into the mechanics and control of movement. We examined force sharing in the gastrocnemius of wild turkeys (Meleagris gallopavo), using strain gauges bonded to bony tendons. Force was measured separately in the lateral (LG) and medial (MG)heads of the gastrocnemius, to evaluate force sharing. We also used inverse dynamics to determine the total force required during swing phase. To determine whether the pattern of force sharing varied depending on the mechanical task, we used running speed (1 to 3.5 m s–1) and limb loading (30 and 60 g added tarsometatarsal mass) to vary the force required at the intertarsal joint. We found that the distribution of force between these two heads varied depending on the phase of the stride cycle. During stance, force was shared in near equal amounts between the two heads and this distribution was unaffected by changes in running speed or limb load. During swing phase, however, there was no force sharing. Force was produced only in the lateral head, and this force was not significantly different from the total force required, as calculated from inverse dynamics. Thus, the LG produced all of the force required for limb extension during swing. This change in the pattern of force sharing between stance and swing supports the theory that force sharing between muscle synergists is task-dependent.
Heart rate regulation and extreme bradycardia in diving emperor penguins
Authors: Meir Jessica U. , Stockard Torre K. , Williams Cassondra L. , Ponganis Katherine V. , Ponganis Paul J.
Published: March 2008

To investigate the diving heart rate (fH) response of the emperor penguin (Aptenodytes forsteri), the consummate avian diver, birds diving at an isolated dive hole in McMurdo Sound, Antarctica were outfitted with digital electrocardiogram recorders, two-axis accelerometers and time depth recorders (TDRs). In contrast to any other freely diving bird,a true bradycardia (fH significantly<fH at rest) occurred during diving [dive fH (total beats/duration)=57±2 beats min–1, fH at rest=73±2 beats min–1 (mean ± s.e.m.)]. For dives less than the aerobic dive limit (ADL; duration beyond which [blood lactate] increases above resting levels), dive fH=85±3 beats min–1, whereas fH in dives greater than the ADL was significantly lower (41±1 beats min–1). In dives greater than the ADL, fH reached extremely low values: fH during the last 5 mins of an 18 min dive was 6 beats min–1. Dive fH and minimum instantaneous fH during dives declined significantly with increasing dive duration. Dive fH was independent of swim stroke frequency. This suggests that progressive bradycardia and peripheral vasoconstriction (including isolation of muscle) are primary determinants of blood oxygen depletion in diving emperor penguins. Maximum instantaneous surface interval fH in this study is the highest ever recorded for emperor penguins (256 beats min–1), equivalent to fH at V̇O2 max.,presumably facilitating oxygen loading and post-dive metabolism. The classic Scholander–Irving dive response in these emperor penguins contrasts with the absence of true bradycardia in diving ducks, cormorants, and other penguin species.
A comparative analysis of putative oxygen-sensing cells in the fish gill
Authors: Coolidge Emily H. , Ciuhandu Cosima S. , Milsom William K.
Published: March 2008

We investigated the distribution of serotonin (5-HT)-containing neuroepithelial cells (NECs), the putative O2 sensing cells, in the gills of four species of fish: trout (Oncorhynchus mykiss), goldfish(Carassius auratus), trairão (Hoplias lacerdae) and traira (Hoplias malabaricus) using immunohistochemical markers for 5-HT, synaptic vesicles and neural innervation. We found that all fish had a cluster of innervated, serotonergic NECs at the filament tips, but there were species-specific distributions of serotonin-containing NECs within the primary gill filaments. Trout gill filaments had a greater number of serotonin-containing NECs than both trairão and traira, whereas goldfish primary filaments had none. Serotonin-containing NECs in the secondary lamellae were most numerous in goldfish, present in trairão and traira, but absent in trout. Those found in the primary filament were generally associated with the efferent filamental artery. Innervated,serotonin-containing cells (NECs or Merkel-like cells) were also found in the gill rakers of trout and goldfish although vesicular serotonin was only found in the gill rakers of goldfish. These differences in serotonergic NEC distribution appear to reflect paracrine versus chemoreceptive roles related to hypoxia tolerance in the different fish species.
Body temperature depression and peripheral heat loss accompany the metabolic and ventilatory responses to hypoxia in low and high altitude birds
Authors: Scott Graham R. , Cadena Viviana , Tattersall Glenn J. , Milsom William K.
Published: March 2008

The objectives of this study were to compare the thermoregulatory,metabolic and ventilatory responses to hypoxia of the high altitude bar-headed goose with low altitude waterfowl. All birds were found to reduce body temperature (Tb) during hypoxia, by up to 1–1.5°C in severe hypoxia. During prolonged hypoxia, Tb stabilized at a new lower temperature. A regulated increase in heat loss contributed to Tb depression as reflected by increases in bill surface temperatures (up to 5°C) during hypoxia. Bill warming required peripheral chemoreceptor inputs, since vagotomy abolished this response to hypoxia. Tb depression could still occur without bill warming, however, because vagotomized birds reduced Tb as much as intact birds. Compared to both greylag geese and pekin ducks, bar-headed geese required more severe hypoxia to initiate Tb depression and heat loss from the bill. However, when Tb depression or bill warming were expressed relative to arterial O2 concentration (rather than inspired O2) all species were similar; this suggests that enhanced O2 loading,rather than differences in thermoregulatory control centres, reduces Tb depression during hypoxia in bar-headed geese. Correspondingly, bar-headed geese maintained higher rates of metabolism during severe hypoxia (7% inspired O2), but this was only partly due to differences in Tb. Time domains of the hypoxic ventilatory response also appeared to differ between bar-headed geese and low altitude species. Overall, our results suggest that birds can adjust peripheral heat dissipation to facilitate Tb depression during hypoxia,and that bar-headed geese minimize Tb and metabolic depression as a result of evolutionary adaptations that enhance O2transport.
Alcohol Oxidation in Ionic Liquid with UHP and Recyclable Amberlite IR-120 Acidic Resin: A Green Approach
Authors: Bhati Nishi , Sarma Kuladip , Goswami Amrit
Published: March 2008

Amberlite IR-120 acidic resin, an age old polymer matrix, plays a significant role as catalyst in the oxidation of aromatic alcohols with urea–hydrogen peroxide in ionic liquid at 70 °C to disproportionate into phenols and carbonyl compounds in 30–60 min following two pathways. Under similar condition tertiary aromatic alcohol gave exclusively monohydroxyphenol accompanied by acetone. However, aliphatic and alicyclic alcohols yielded carbonyl compounds in moderate to good yields in 1–5 h.
Barium-stabilized Sr2AlxSi12−xN16−xOx+2:Eu Green Phosphor for White Light UVLED
Authors: Xie Wenjie , Wang Yachong , Xu Xin , Chen Chusheng
Published: March 2008

We discovered the stabilization effect of only 1 wt % Ba on synthesizing Eu2+-doped pure Sr–S-phase(Sr2AlxSi12−xN16−xOx+2) under a moderate condition and studied their luminescent properties. The excitation band is at UV–vis spectral region which is about 300–370 nm, and the emission band at 508–538 nm. The emission wavelength changes from 508 to 538 nm as a function of Eu2+ concentration, and the maximum emission intensity could be obtained with the Eu2+ concentration of 0.2. This phosphor can be the potential candidate for using as the green phosphor for UVLED-based white light.
Reversible Single Crystal-to-Amorphous Phase Transition upon Dehydration–Rehydration and Associated Magnetism in [MnII(enH)(H2O)][CrIII(CN)6]·H2O
Authors: Yoshida Yusuke , Inoue Katsuya , Kurmoo Mohamedally
Published: March 2008

We report the rare occurrence of a reversible loss of crystallinity upon dehydration and regain upon rehydration by in situ X-ray diffraction on a single crystal of [MnII(enH)(H2O)][CrIII(CN)6]·H2O and the associated thermal and magnetic properties characterized by an increase of the Curie temperature of the soft ferrimagnet from 42 to 75 K.
Abdominal aortic aneurysms, screening and the law
Authors: Heather Brian P
Published: March 2008

The nature and the natural history of abdominal aortic aneurysms (AAAs) are discussed, together with current treatment options. The place of population screening for AAA is considered, particularly in the light of the Government's recent announcement of a national screening programme. Likely sources of patient complaints concerning the diagnosis, surveillance, treatment and follow-up of AAAs are discussed.
Testing rates for sexually transmitted infections among HIV-infected men who have sex with men attending two different HIV services
Authors: Teague Richard , Mijch Anne , Fairley Christopher K , Sidat Mohsin , Watson Kerrie , Boyd Kerri , Chen Marcus Y
Published: March 2008

Summary

This study compares the testing rates of bacterial sexually transmitted infections (STIs) among HIV-positive men who have sex with men (MSM) attending two HIV clinics in Melbourne. Data on STI testing over a 12-month period were obtained for all HIV-positive MSM who attended the clinics between January and March 2006. Screening rates for bacterial STIs were significantly higher at a sexual health clinic (n = 254) compared with an infectious diseases clinic (n = 351), whether this was measured according to: at least one STI test being performed for chlamydia, gonorrhoea or syphilis (69% vs. 38%, P < 0.01); serological testing for syphilis alone (67% vs. 34%, P < 0.01); or ‘complete’ STI screening for pharyngeal gonorrhoea, urethral chlamydia, anal gonorrhoea, anal chlamydia and syphilis (41% vs. 6%, P < 0.01). Substantial differences in STI testing rates among HIV-positive MSM may exist between HIV clinical services depending on the measures in place that promote STI screening.
Low seroprevalence of herpes simplex virus type 2 among pregnant women in Senegal
Authors: Diawara Silman , Kane Coumba Toure , Legoff JÉRÔMe , Gaye Astou Gueye , Mboup Souleymane , BÉLec Laurent
Published: March 2008

Summary

Herpes simplex virus type 2 (HSV-2) is considered as a major co-factor of both sexual transmission and acquisition of the human immunodeficiency virus (HIV). The HIV epidemic in Senegal is characterized by a remarkable and stable low prevalence. Whether HSV-2 may also constitute a possible co-factor favouring the spreading of HIV epidemic in Senegal is yet unknown. This prompted us to evaluate the HSV-2 seroprevalence in the sentinel population of pregnant women in Senegal. Two hundred and sixty pregnant women attending Roi Baudouin maternity in the capital city Dakar (n = 135) and the antenatal clinic in Kaolack (n = 125), the third city of Senegal, were prospectively recruited between March and August 2003. Fifty-six women (22%) were positive for HSV-2 serology. The prevalence of HSV-2 seropositivity was higher in women living in Dakar (26%) than in those living in Kaolack (16%) (P < 0.01). Only two women from Dakar and two other from Kaolack were found to be HIV-1-infected. Our observations suggest a seemingly low seroprevalence of HSV-2 infection in adult women Senegal, comparable with those usually reported in Western countries. Further, epidemiological surveys are needed to confirm these results in the general population.
The demographical and clinical features of patients reattending a genitourinary medicine clinic and the role of counselling on subsequent incidence of sexually transmitted infections
Authors: Manavi K , Bolton N
Published: March 2008

Summary

The aim of this study was to investigate the incidence of reinfection with sexually transmitted infection (STI) and its possible predicting factors among patients reattending a department of genitourinary (GU) medicine. The method included a retrospective study on consecutive patients re-screened for STI in a busy department of GU medicine between January 1996 and April 2005. Cox regression model was used to investigate the association of age, gender, sex group, previous STI, counselling for an STI on the last attendance, number of sexual partners in the previous attendance episode, condom use and the number for partners with whom they had unprotected sex, with STI at current screening. The results show that 302 consecutive patients with more than two attendance episodes were included in the study. Patients were mostly women (92%), younger than 35 years (80%) and heterosexual (98%). At baseline, 70 (23%) patients had STI. The incidence density of STI at the end of follow-up period was 15.69/100 person-years. Testing positive for an STI was associated with age younger than 25 years (hazard ratio 2.70 [95% confidence interval 1.70–4.57]; P = 0.000). In conclusion, our study confirmed the improvement in access to GU medicine services, encouragement of patients with an STI for re-screening on regular basis and use of novel STI counselling strategies, especially for younger patients may reduce the incidence of subsequent STI.
Variation in the dynamic stiffness index of different types of medical elastic compression stockings
Authors: van der Wegen-Franken C P M , Mulder P , Tank B , Neumann H A M
Published: March 2008

Objectives

To calculate the dynamic stiffness index (DSI) of 18 different brands of medical elastic compression stockings (MECS).

Methods

In all, 18 different brands of MECS that were divided into five categories (class II round-knitted, class II flat-knitted, class III round-knitted, class III flat-knitted and class IV flat-knitted MECS) were tested. The static pressure and dynamic pressure pulsations at the B1 level were measured with a newly developed dynamic pressure-determining device. The DSI was calculated.

Results

The DSI of all 18 brands of MECS showed higher values compared with the static stiffness. A wide range of dynamic stiffness indices was observed not only between all brands of MECS, but also within the five categories.

Conclusions

The DSI of MECS is independent of the compression class and the type of knit. The variation in the DSIs between MECS is not because of any measurement error and would indicate that different therapeutic effectiveness may be expected within one compression class. Therefore, a refinement in the current classification system for MECS with other characteristics such as the DSI is warranted.
Mechanisms of varicose vein formation: valve dysfunction and wall dilation
Authors: Raffetto J D , Khalil R A
Published: March 2008

Varicose veins are a common venous disease of the lower extremity. Although the mechanisms and determinants in the development of varicosities are not clearly defined, recent clinical studies and basic science research have cast some light on possible mechanisms of the disease. In varicose veins, there are reflux and incompetent valves as well as vein wall dilation. Primary structural changes in the valves may make them ‘leaky’, with progressive reflux causing secondary changes in the vein wall. Alternatively, or concurrently, the valves may become incompetent secondary to structural abnormalities and focal dilation in vein wall segments near the valve junctions, and the reflux ensues as an epiphenomenon. The increase in venous pressure causes structural and functional changes in the vein wall that leads to further venous dilation. Increase in vein wall tension augments the expression/activity of matrix metalloproteinases (MMPs), which induces degradation of the extracellular matrix proteins and affect the structural integrity of the vein wall. Recent evidence also suggests an effect of MMPs on the endothelium and smooth muscle components of the vein wall and thereby causing changes in the venous constriction/relaxation properties. Endothelial cell injury also triggers leukocyte infiltration, activation and inflammation, which lead to further vein wall damage. Thus, vein wall dilation appears to precede valve dysfunction, and the MMP activation and superimposed inflammation and fibrosis would then lead to chronic and progressive venous insufficiency and varicose vein formation.
Injuries to the tibiofibular syndesmosis
Authors: Dattani R. , Patnaik S. , Kantak A. , Srikanth B. , Selvan T. P.
Published: March 2008

The management of injury to the distal tibiofibular syndesmosis remains controversial in the treatment of ankle fractures. Operative fixation usually involves the insertion of a metallic diastasis screw. There are a variety of options for the position and characterisation of the screw, the type of cortical fixation, and whether the screw should be removed prior to weight-bearing. This paper reviews the relevant anatomy, the clinical and radiological diagnosis and the mechanism of trauma and alternative methods of treatment for injuries to the syndesmosis.
Anatomy of the lateral retinaculum of the knee
Authors: Merican A. M. , Amis A. A.
Published: March 2008

Anatomical descriptions of the lateral retinaculum have been published, but the attachments, name or even existence of its tissue bands and layers are ill-defined. We have examined 35 specimens of the knee. The deep fascia is the most superficial layer and the joint capsule is the deepest. The intermediate layer is the most substantial and consists of derivatives of the iliotibial band and the quadriceps aponeurosis. The longitudinal fibres of the iliotibial band merge with those of the quadriceps aponeurosis adjacent to the patella. These longitudinal fibres are reinforced by superficial arciform fibres and on the deep aspect by transverse fibres of the iliotibial band. The latter are dense and provide attachment of the iliotibial band to the patella and the tendon of vastus lateralis obliquus.

Our study identifies two important new findings which are a constant connection of the deep fascia to the quadriceps tendon superior and lateral to the patella, and, a connection of the deeper transverse fibres to the tendon of vastus lateralis obliquus.
The development and validation of a patient-reported questionnaire to assess outcomes of elbow surgery
Authors: Dawson J. , Doll H. , Boller I. , Fitzpatrick R. , Little C. , Rees J. , Jenkinson C. , Carr A. J.
Published: March 2008

We developed a questionnaire to assess patient-reported outcome after surgery of the elbow from interviews with patients. Initially, 17 possible items with five response options were included. A prospective study of 104 patients (107 elbow operations) was carried out to analyse the underlying factor structure, dimensionality, internal and test-retest reliability, construct validity and responsiveness of the questionnaire items. This was compared with the Mayo Elbow performance score clinical scale, the Disabilities of the Arm, Shoulder and Hand questionnaire, and the Short-Form (SF-36) General Health Survey. In total, five questions were considered inappropriate, which resulted in the final 12-item questionnaire, which has been referred to as the Oxford elbow score. This comprises three unidimensional domains, ‘elbow function’, ‘pain’ and ‘social-psychological’; with each domain comprising four items with good measurement properties.

This new 12-item Oxford elbow score is a valid measure of the outcome of surgery of the elbow.
Chromium, cobalt and titanium metallosis involving a Nottingham shoulder replacement
Authors: Khan W. S. , Agarwal M. , Malik A. A. , Cox A. G. , Denton J. , Holt E. M.
Published: March 2008

Metallosis after shoulder replacement has not previously been described in the literature. We report a patient who developed extensive metallosis after implantation of an uncemented Nottingham shoulder replacement. He underwent a revision procedure.

Examination of the retrieved prosthesis showed that the titanium porous coating was separating from the humeral stem and becoming embedded in the ultra-high-molecular-weight polyethylene glenoid component, resulting in abrasive wear of the humeral component. There was metallosis despite exchange of the modular humeral head. Both components had to be exchanged to resolve the problem.
The Unispacer knee implant
Authors: Bailie A. G. , Lewis P. L. , Brumby S. A. , Roy S. , Paterson R. S. , Campbell D. G.
Published: March 2008

The Unispacer knee system is a cobalt-chrome self-centring tibial hemiarthroplasty device for use in the treatment of isolated medial compartment osteoarthritis of the knee. The indications for use are similar to those for high tibial osteotomy, but insertion does not require bone cuts or component fixation, and does not compromise future knee replacement surgery. A prospective study of a consecutive series of 18 patients treated with the Unispacer between June 2003 and August 2004 was carried out to determine the early clinical results of this device. The mean age of the patients was 49 years (40 to 57). A total of eight patients (44%) required revision within two years. In two patients revision to a larger spacer was required, and in six conversion to either a unicompartmental or total knee replacement was needed. At the most recent review 12 patients (66.7%) had a Unispacer remaining in situ. The mean modified visual analogue score for these patients at a mean follow-up of 19 months (12 to 26) was 3.0 (0 to 11.5). The mean pain level was 30% that of the mean pre-operative level of 10. The early clinical results using this device have been disappointing.

This study demonstrates that use of the Unispacer in isolated medial compartment osteoarthritis is associated with a high rate of revision surgery and provides unpredictable relief of pain.
A comparison of augmentation techniques for reconstruction of the extensor mechanism following proximal tibial replacement in an experimental animal model
Authors: Pendegrass C. J. , Sundar S. , Oddy M. J. , Cannon S. R. , Briggs T. , Blunn G. W.
Published: March 2008

We used an in vivo model to assess the use of an autogenous cancellous bone block and marrow graft for augmenting tendon reattachment to metallic implants. We hypothesised that augmentation of the tendon-implant interface with a bone block would enable retention of the graft on the implant surface, enhance biological integration, and result in more consistent functional outcomes compared with previously reported morcellised graft augmentation techniques.

A significant improvement in functional weight-bearing was observed between six and 12 weeks. The significant increase in ground reaction force through the operated limb between six and 12 weeks was greater than that reported previously with morcellised graft augmented reconstructions. Histological appearance and collagen fibre orientation with bone block augmentation more closely resembled that of an intact enthesis compared with the morcellised grafting technique. Bone block augmentation of tendon-implant interfaces results in more reliable functional and histological outcomes, with a return to pre-operative levels of weight-bearing by 24 weeks.
Transferring simulated arthroscopic skills to the operating theatre
Authors: Howells N. R. , Gill H. S. , Carr A. J. , Price A. J. , Rees J. L.
Published: March 2008

The aim of this study was to investigate the effect of laboratory-based simulator training on the ability of surgical trainees to perform diagnostic arthroscopy of the knee.

A total of 20 junior orthopaedic trainees were randomised to receive either a fixed protocol of arthroscopic simulator training on a bench-top knee simulator or no additional training. Motion analysis was used to assess performance objectively. Each trainee then received traditional instruction and demonstrations of diagnostic arthroscopy of the knee in theatre before performing the procedure under the supervision of a blinded consultant trainer. Their performance was assessed using a procedure-based assessment from the Orthopaedic Competence Assessment Project and a five-point global rating assessment scale.

In theatre the simulator-trained group performed significantly better than the untrained group using the Orthopaedic Competence Assessment Project score (p = 0.0007) and assessment by the global rating scale (p = 0.0011), demonstrating the transfer of psychomotor skills from simulator training to arthroscopy in the operating theatre. This has implications for the planning of future training curricula.
Trends in Circulating Concentrations of Total Homocysteine among US Adolescents and Adults: Findings from the 1991–1994 and 1999–2004 National Health and Nutrition Examination Surveys
Authors: Pfeiffer Christine M , Osterloh John D , Kennedy-Stephenson Jocelyn , Picciano Mary Frances , Yetley Elizabeth A , Rader Jeanne I , Johnson Clifford L
Published: March 2008

Background: The National Health and Nutrition Examination Survey (NHANES) has monitored total homocysteine (tHcy) concentrations in a nationally-representative sample of the US population since 1991. Until recently, however, data could not be compared across survey periods because of changes in analytical methods and specimen matrices. Such an analysis of these data could supplement current knowledge regarding whether the US folic acid fortification program has modified national plasma tHcy concentrations.

Methods: We examined tHcy data in the prefortification NHANES III survey (phase II, 1991–1994) and in 3 postfortification survey periods (1999–2000, 2001–2002, and 2003–2004). We applied method adjustment equations to the survey data based on method comparison studies of separate samples. Persons with chronic kidney disease were excluded from the analyses.

Results: Mean plasma tHcy concentrations decreased by 8%, 9%, and 10% for adolescent, adult, and older men and by 6%, 3%, and 13% for women, respectively, from before to after fortification. Concentrations remained unchanged between the first and third postfortification survey periods. Prevalence estimates of increased plasma tHcy concentrations (>13 μmol/L) for older men and women decreased from prefortification (32% and 20%, respectively) to postfortification (14% and 5%, respectively) but remained unchanged thereafter (16% and 14%, respectively [males] and 5% and 9%, respectively [females]).

Conclusions: After adjusting for method changes, we quantified a prefortification to postfortification decrease in circulating tHcy concentrations of about 10% in a national sample of the US population. This change is similar to effects seen in intervention trials with folic acid and in smaller observational studies.
Association between the UGT1A1 TA-Repeat Polymorphism and Bilirubin Concentration in Patients with Intermittent Claudication: Results from the CAVASIC Study
Authors: Rantner Barbara , Kollerits Barbara , Anderwald-Stadler Marietta , Klein-Weigel Peter , Gruber Ingrid , Gehringer Anke , Haak Markus , Schnapka-Köpf Mirjam , Fraedrich Gustav , Kronenberg Florian
Published: March 2008

Background: Bilirubin has antioxidative and cytoprotective properties. Low plasma concentrations of bilirubin are reportedly associated with the development of coronary and cerebrovascular disease, and bilirubin concentrations are strongly correlated with the enzyme activity of the hepatic uridine diphosphate glucuronosyltransferase (UGT1A1). The activity of UGT1A1 is influenced by a TA-repeat polymorphism in the promoter of the UGT1A1 gene (UDP glucuronosyltransferase 1 family, polypeptide A1). In a case-control study, we investigated the association between the UGT1A1 polymorphism, bilirubin concentration, and intermittent claudication.

Methods: We included 255 consecutive male patients presenting with intermittent claudication in the investigation and matched the patients by age and diabetes mellitus with 255 control individuals.

Results: Plasma bilirubin concentrations were significantly lower in patients than in controls [mean (SD), 12.5 (5.3) μmol/L vs 15.4 (7.9) μmol/L; P < 0.001]. We found a clear association between the number of TA repeats and plasma bilirubin concentration. Considering the 6/6 TA-repeat genotype as the wild type, we observed a slight increase in bilirubin concentration individuals with the heterozygous 6/7 genotype and pronounced increases for those with the homozygous 7/7 genotype. This association occurred in both controls and patients; however, patients and controls were not significantly different with respect to UGT1A1 TA-repeat genotype frequencies.

Conclusions: Our study of a well-phenotyped group of patients with intermittent claudication and control individuals revealed a clear association between low bilirubin concentrations and peripheral arterial disease but no association between the UGT1A1 polymorphism and the disease.
Regelung des lagerlosen Segmentmotors (Control Concept for the Bearingless Segment Motor)
Authors: Gruber Wolfgang , Amrhein Wolfgang , Grabner Herbert
Published: March 2008

In diesem Beitrag wird ein neuartiges Aktorprinzip für magnetisch gelagerte Antriebe vorgestellt. Für diese neue Scheibenläuferkonstruktion wird nach der Modellbildung auch ein entsprechendes Regelschema in Form der Eingangs-/Zustandslinearisierung hergeleitet. Zur Realisierung des Konzeptes auf einem digitalen Signalprozessor wurden Entwicklungswerkzeuge für die Finite-Elemente-Simulation (Matmag) und die Programmierung des Prozessors (M2C) realisiert. Beide Tools basieren auf dem numerischen Algebraprogramm Matlab von Mathworks. Abschließend wird auf die beiden lagerlosen Segmentmotor-Prototypen mit ihren unterschiedlichen Betriebseigenschaften eingegangen.

This article introduces a new actuator principle for magnetically levitated drive systems. The resulting bearingless motor is a subtype of the bearingless slice motor. A proper modelling is done and a suitable control scheme is presented by the help of nonlinear feedback control. For easier implementation of the control concept on a digital signal processor development tools have been created. These tools help calculating finite element simulations (Matmag) and coding the processor (M2C). Both of these tools are based on the numerical algebra software Matlab developed by Mathworks. Finally two bearingless segment motor prototypes with different operation behaviour are presented.
Hydrothermal synthesis of Co-doped In2S3 micropompons and their physical properties
Authors: Datta Anuja , Ganguli Dibyendu , Chaudhuri Subhadra
Published: March 2008

In2−xCoxS3 (x = 0 to 0.1) micropompons (diameters ∼3–4 μm) consisting of ∼10–15-nm-thick randomly self-assembled nanoflakes were synthesized hydrothermally. X-ray study indicated a steady variation of lattice parameter ratio up to 5% Co. Detailed investigations of the Co incorporation in In2S3 were carried out by optical absorbance, room temperature photoluminescence (PL), and electron paramagnetic resonance (EPR) studies. Significant blue shift in the absorbance spectra was noticed due to the crystal-field splitting of Co2+ ions in the host lattice structure. Unlike the visible emission found in undoped In2S3, PL spectra of the Co-doped samples were recognized by a strong ultraviolet emission peak at ∼335 nm, introduced by the t2g level of Co2+ ions, with maximum intensity for 5% Co. Room-temperature and low-temperature EPR spectra revealed octet paramagnetic bands up to 5% Co beyond which a single resonance band appeared.
Postpressing dependence of the effective electron diffusion coefficient in electrophoretically prepared nanoporous ZnO and TiO2films
Authors: Dor S. , Dittrich Th. , Ofir A. , Grinis L. , Zaban A.
Published: March 2008

The porosity of electrophoretically prepared nanoporous ZnO and TiO2films was systematically decreased by postpressing at different pressures. The nanoporous structure of the films was fixed by sintering after the postpressing procedure. The postpressing-induced change of the internal surface area of the nanoporous films was monitored using the dye-removal technique. The effective electron diffusion coefficient (Deff) of the unpressed nanoporous films depended on the thickness according to Fick’s second law. When pressed, the diffusion coefficient of the films increases significantly. In nanoporous TiO2, the increase ofDefffollows the percolation theory where transport rate depends on the particle-coordination number. In contrast to the TiO2films, the value ofDeffof pressed nanoporous ZnO films changed with the porosity much stronger than one would expect from the percolation theory with hard spheres. This property has been attributed to the strong increase of necking between ZnO nanoparticles with increasing pressure as indicated by a strong decrease of the internal surface area.
Plasticity of bulk metallic glasses improved by controlling the solidification condition
Authors: Zhu Z.W. , Zheng S.J. , Zhang H.F. , Ding B.Z. , Hu Z.Q. , Liaw P.K. , Wang Y.D. , Ren Y.
Published: March 2008

Different bulk metallic glasses (BMGs) were prepared in ductile Cu47.5Zr47.5Al5, Zr62Cu15.4Ni12.6Al10, and brittle Zr55Ni5Al10Cu30 alloys by controlling solidification conditions. The achieved microstructures were characterized by x-ray diffraction, differential scanning calorimetry, transmission electron microscopy, and synchrotron- based high-energy x-ray diffraction. Monolithic BMGs obtained by high-temperature injection casting are brittle, while BMGs bearing some nanocrystals with the size of 3 to 7 nm and 2 to 4 nm, obtained by low-temperature injection casting and in situ suction casting, respectively, exhibit good plasticity. It indicates that the microstructures of BMGs are closely affected by the solidification conditions. Controlling the solidification conditions could improve the plasticity of BMGs.
A modified embedded-atom method interatomic potential for the Cu–Zr system
Authors: Kim Young-Min , Lee Byeong-Joo
Published: March 2008

A modified embedded-atom method (MEAM) interatomic potential for the Cu–Zr system has been developed based on the previously developed MEAM potentials for pure Cu and Zr. The potential describes fundamental physical properties and alloy behavior of the Cu–Zr binary system reasonably well. The applicability of the potential to atomistic investigations of mechanical and deformation behavior for the Cu–Zr binary and Cu–Zr-based multicomponent amorphous alloys is also demonstrated by showing that fully relaxed and realistic amorphous structures can be generated by molecular dynamics simulations.
Synthesis of water-soluble PbSe quantum dots
Authors: Etgar Lioz , Lifshitz Efrat , Tannenbaum Rina
Published: March 2008

Water-soluble PbSe semiconductor quantum dots (QDs) with near-infrared absorption of 1100–2520 nm (corresponding to a diameter of 3–13 nm) were synthesized using 2-aminoethanthiol (AET). The oleic acid-stabilizing ligands used in the traditional synthesis of PbSe were exchanged with the 2-AET ligands, which promoted the solubilization of the QDs in an aqueous medium. This occurred due to the attraction of the surrounding water molecules to the exposed amino group, thus allowing the particles to reside in the water environment. The water-soluble PbSe QDs have very narrow size distribution (σ ≈ 4.5–5.5%). Transmission electron microscopy, spectrophotometric measurements, and Fourier transform infrared spectroscopy indicate that the morphology, size, size distribution, and chemical composition of the PbSe QDs remained unchanged during the transfer to an aqueous medium. In conclusion, the ability to synthesize water-soluble PbSe QDs with stable properties and uniform size distribution will allow them to have substantial advantages for biological applications such as biosensors and drug delivery.