bluuebunny/crossref_metadata_2025_split huggingface dataset:
Male indifference to female traits in an arctiid moth (Utetheisa ornatrix)
Authors: Iyengar Vikram K. , Eisner Thomas 
Published: May 2004

Abstract.  1. Female Utetheisa ornatrix (Lepidoptera: Arctiidae) mate selectively with large males able to transmit sizeable quantities of nutrient and defensive pyrrolizidine alkaloid with the spermatophore. The female gauges male size indirectly by assessment of the male's courtship pheromone.2. Male Utetheisa invest upward of 10% of body mass in spermatophore production, and could therefore have been expected to be choosy; however, when offered females differing in alkaloid content, body mass, or mating status, males showed disregard of these parameters, both in their choice of partner and in their allocation of resources to the spermatophore.3. It is concluded that Utetheisa males do not have the option to select females by comparison shopping. Females broadcast their attractant pheromone for less than an hour per day. Given this time constraint and the potentially high cost of mate localisation, males may have no choice but to mate on an opportunistic basis.
Morphometric analysis of shank‐to‐flute ratio in rotary nickel–titanium files
Authors: Biz M. T. , Figueiredo J. A. P. 
Published: May 2004

AbstractAim  To evaluate the shank‐to‐flute ratio in rotary nickel–titanium (Ni‐Ti) instruments.Methodology  The cutting portion of 15 size 30 Ni‐Ti rotary instruments, ProFile .04, ProFile .06, Pow R .02, Pow R .04 and Quantec series 2000, were examined. The handles of the instruments were fixed to a bench and supported by a removable resin base. The cutting portion was then manually abraded with abrasive strips along one aspect of their length. All instruments were fixed in a stub that permitted the adaptation and inspection of six instruments at the same time. A scanning electron microscope (SEM; Phillips model XL 20; Eindhmoven, the Netherlands) at ×60 magnification was used to collect cross‐sectional measurements of the shank and the flutes at the first, third and fifth flutes from the tip. The software autocad 2000 was used to measure these areas.Results  The shank percentage value was, on average, equal to or greater than the flute percentage value at the sites analyzed. A regular and proportional pattern of increase of shank and flute measurements, as well as the ratio between them, was preserved. There was no significant difference between instruments and between flute sites on the same instrument (P > 0.05). However, the Quantec instruments had a flute area twice the flute area of the other instruments.Conclusions The instruments had a shank percentage measurement value equal to or greater than the flute percentage value; the cross‐sectional shank‐to‐flute ratio was preserved. The instruments had similar shank areas, but the flute area of the Quantec instruments was twice their shank area; i.e. the design of the Quantec files provides longitudinal reinforcement by means of a gain in flute area.
Accuracy of the DTC torque control motor for nickel‐titanium rotary instruments
Authors: Yared G. , Kulkarni G. K. 
Published: May 2004

AbstractAim  To determine the torque output and examine the accuracy of five identical DTC torque control (DTC) motors.Methodology  Torque settings on the DTC motors for the .04 ISO ProFile nickel‐titanium (NiTi) rotary instruments were evaluated at 350 r.p.m. A modification of the ANSI/ADA Specification No. 28 setup for the evaluation of torsional properties of endodontic instruments was used. A handpiece was attached to the motor and gripped with a vice. An .07 Orifice Shaper, size 50, was inserted in the handpiece. The instrument tip was clamped in a chuck connected to a torque sensor. The motor was then activated to rotate the instrument in a clockwise direction until reversal of the rotation occurred. The actual torque generated at the reversal of the rotation was recorded. Ten tests were carried out at each torque setting. A new Orifice Shaper was used for each test. The means of the actual torque values generated by the motors at the different torque settings were compared with the torque values claimed by the manufacturer and analysed using analysis of variance and the Student's t‐test (α = 0.05).Results  The actual torque values were significantly higher than the torque preset on the motors (P < 0.0001) and did not differ significantly among the motors (P > 0.05).Conclusions  The actual torque deviated from the preset torque and was higher than the reported torque at fracture of several NiTi rotary instruments. The usefulness of these motors is questionable.
Screening for synthetic lethal mutants in Escherichia coli and identification of EnvC (YibP) as a periplasmic septal ring factor with murein hydrolase activity
Authors: Bernhardt Thomas G. , De Boer Piet A. J. 
Published: May 2004

SummaryBacterial cytokinesis is driven by the septal ring apparatus, the assembly of which in Escherichia coli is directed to mid‐cell by the Min system. Despite suffering aberrant divisions at the poles, cells lacking the minCDE operon (Min–) have an almost normal growth rate. We developed a generally applicable screening method for synthetic lethality in E. coli, and used it to select for transposon mutations (slm) that are synthetically lethal (or sick) in combination with ΔminCDE. One of the slm insertions mapped to envC (yibP), proposed to encode a lysostaphin‐like, metallo‐endopeptidase that is exported to the periplasm by the general secretory (Sec) pathway. Min– EnvC– cells showed a severe division defect, supporting a role for EnvC in septal ring function. Accordingly, we show that an EnvC–green fluorescent protein fusion, when directed to the periplasm via the twin‐arginine export system, is both functional and part of the septal ring apparatus. Using an in‐gel assay, we also present evidence that EnvC possesses murein hydrolytic activity. Our results suggest that EnvC plays a direct role in septal murein cleavage to allow outer membrane constriction and daughter cell separation. By uncovering genetic interactions, the synthetic lethal screen described here provides an attractive new tool for studying gene function in E. coli.
Homozygosity at the MTL locus in clinical strains of Candida albicans: karyotypic rearrangements and tetraploid formation†
Authors: Legrand Melanie , Lephart Paul , Forche Anja , Mueller Frank‐Michael C. , Walsh T. , Magee P.T. , Magee Beatrice B. 
Published: May 2004

SummaryOne hundred and twenty Candida albicans clinical isolates from the late 1980s and early 1990s were examined for homozygosity at the MTL locus. Of these, 108 were heterozygous (MTLa/MTLα), whereas seven were MTLa and five were MTLα. Five of the homozygous isolates were able to switch to the opaque cell morphology, while opaque cells were not detectable among the remaining seven. Nevertheless, all but one of the isolates homozygous at the MTL locus were shown to mate and to yield cells containing markers from both parents; the non‐mater was found to have a frameshift in the MTLα1 gene. In contrast to Saccharomyces cerevisiae, C. albicans homozygotes with no active MTL allele failed to mate rather than mating as a cells. There was no correlation between homozygosity and fluconazole resistance, mating and fluconazole resistance or switching and fluconazole resistance, in part because most of the strains were isolated before the widespread use of this antifungal agent, and only three were in fact drug resistant. Ten of the 12 homozygotes had rearranged karyotypes involving one or more homologue of chromosomes 4, 5, 6 and 7. We suggest that karyotypic rearrangement, drug resistance and homozygosity come about as the result of induction of hyper‐recombination during the infection process; hence, they tend to occur together, but each is the independent result of the same event. Furthermore, as clinical strains can mate and form tetraploids, mating and marker exchange are likely to be a significant part of the life cycle of C. albicans in vivo.
Role of KatG catalase‐peroxidase in mycobacterial pathogenesis: countering the phagocyte oxidative burst
Authors: Ng Vincent H. , Cox Jeffery S. , Sousa Alexandra O. , MacMicking John D. , McKinney John D. 
Published: May 2004

SummaryReactive nitrogen species (RNS) play an essential role in host defence against Mycobacterium tuberculosis (MTB) in the mouse model of tuberculosis (TB), as evidenced by the increased susceptibility of mice deficient in the inducible isoform of nitric oxide synthase (NOS2). In contrast, the role of reactive oxygen species (ROS) in protection against MTB is less clear, and mice defective in the ROS‐generating phagocyte NADPH oxidase (Phox) are relatively resistant. This suggests that MTB might possess efficient mechanisms to evade or counter the phagocyte oxidative burst, effectively masking the impact of this host defence mechanism. In order to assess the role of ROS detoxification pathways in MTB virulence, we generated a katG null mutant of MTB, deficient in the KatG catalase‐peroxidase‐peroxynitritase, and evaluated the mutant's ability to replicate and persist in macrophages and mice. Although markedly attenuated in wild‐type C57Bl/6 mice and NOS2–/– mice, the ΔkatG MTB strain was indistinguishable from wild‐type MTB in its ability to replicate and persist in gp91Phox–/– mice lacking the gp91 subunit of NADPH oxidase. Similar observations were made with murine bone marrow macrophages infected ex vivo: growth of the ΔkatG MTB strain was impaired in macrophages from C57Bl/6 and NOS2–/– mice, but indistinguishable from wild‐type MTB in gp91Phox–/– macrophages. These results indicate that the major role of KatG in MTB pathogenesis is to catabolize the peroxides generated by the phagocyte NADPH oxidase; in the absence of this host antimicrobial mechanism, KatG is apparently dispensable.
Historical catchment changes and temporal impact on sediment of the receiving basin, Port Jackson, New South Wales
Authors: TAYLOR S. E. , BIRCH G. F. , LINKS F. 
Published: May 2004

Port Jackson (Sydney Harbour) is a major deep‐water estuary on the central New South Wales coast and is surrounded by a highly urbanised and industrialised catchment. Concentrations of trace metals and organochlorine pesticide residues are high in sediment in the upper reaches of the estuary. Historical fluxes of contaminants into the estuary were determined by radio‐isotopic dating of 12 sediment profiles in nine highly contaminated embayments. The onset of contamination in estuarine sediment was correlated with catchment‐wide urbanisation and industrialisation of Sydney. Contamination of estuarine sediment in Port Jackson first occurred ca 1860, near the present central business district and spread westward and northward. Trace‐metal contamination was initiated ∼20 years after the commencement of industry in the subcatchments, and a rapid increase in trace‐metal concentrations corresponds closely with maximum industrial activity in these catchments. Organochlorine pesticide residues occur in estuarine sediments 40–50 years after the onset of contamination by trace metals and their appearance closely corresponds with the manufacturing and application history of these compounds. The transit time of contaminants from fluvial catchment to incorporation in estuarine sediment is short (probably <2 years). Trace metals in sediment reached maximum concentrations in 1970 and a subsequent decrease in concentrations in the upper estuary reflects relocation of industry away from the estuary foreshores and tighter controls on industrial discharges. In Middle Harbour and the lower estuary, trace‐metal concentrations continue to increase, due to the comparatively recent increases in commercial and industrial growth in these areas.
Variety, age and origin of zircons in the mid‐Cenozoic Westonia Formation, southwestern Yilgarn Craton, Western Australia
Authors: De BROEKERT P. P. , WILDE S. A. , KENNEDY A. K. 
Published: May 2004

The Westonia Formation comprises clayey quartz sand commonly exposed in interfluve breakaways in the southwestern Yilgarn Craton, Western Australia. As is typical of Cenozoic sediments in the region, it is texturally immature, poorly stratified and unfossiliferous, making it difficult to distinguish from the underlying deeply weathered Archaean granite. In order to verify the difference in origin and elucidate provenance, the varietal properties and U–Pb ages of zircons from the Westonia Formation and underlying granitic saprolite were compared. Zircons from the Westonia Formation comprise 11 distinct morphological varieties, seven of which are not present within the granitic saprolite. SHRIMP U–Pb ages of zircons from the granitic saprolite range from 2657 ± 13 to 2554 ± 10 Ma, corresponding to published age determinations of zircons from the Darling Range Batholith. Angular zircons from the Westonia Formation range in age from 2898 ± 12 to 2631 ± 11 Ma, reflecting a mixed provenance including local granitic rocks, and possibly greenstones in adjacent parts of the Yilgarn Craton. Rounded zircons from the Westonia Formation range in age from 1144 ± 38 to 467 ± 16 Ma (Late Mesoproterozoic – Early Palaeozoic), similar to detrital zircons from the Jarrahdale bauxite deposit and various stratigraphic levels in the Perth Basin. The Late Mesoproterozoic – Early Palaeozoic zircons at East Yornaning and Jarrahdale most likely resulted from burial of the southwestern Yilgarn Craton by sediment sourced from the Proterozoic Albany–Fraser–Wilkes and Pinjarra Orogens during the Early Permian glaciation, or during an earlier episode of mountain building associated with the final stages of the Pinjarra Orogeny. Most of the sedimentary cover was then reworked into the evolving Perth Basin during the Late Permian – Early Cretaceous. Remaining pockets on the craton were repeatedly recycled, leaving only the most chemically and physically resistant components, such as rounded zircons, in the Westonia Formation.
Enhanced P2X7Activity in Human Fibroblasts From Diabetic Patients
Authors: Solini Anna , Chiozzi Paola , Morelli Anna , Adinolfi Elena , Rizzo Roberta , Baricordi Olavio R. , Di Virgilio Francesco 
Published: May 2004

Objective—We have investigated expression and function of the P2X7receptor in fibroblasts from healthy subjects and patients with type 2 diabetes.Methods and Results—Fibroblasts were isolated from skin biopsies. P2X7receptor expression in both cell populations was measured by functional assays, RT-PCR, fluorescence-activated cell sorter, and immunoblotting. We found that fibroblasts from diabetic subjects are characterized by enhanced P2X7-mediated responses as indicated by increased shape changes, microvesiculation, enhanced fibronectin and interleukin 6 secretion, and accelerated apoptosis. These responses were blocked by preincubation with the P2X blockers KN-62, oxidized ATP, or pyridoxal phosphate-6-azo(benzene-2,4-disulfonic acid). Furthermore, we also found a higher level of spontaneous fibronectin secretion and of apoptosis in fibroblasts from diabetic compared with healthy subjects. Both higher basal level of fibronectin secretion and spontaneous rate of apoptosis were likely attributable to the increased pericellular concentration of ATP because fibroblasts from diabetic subjects released 3× as much ATP into the supernatants compared with fibroblasts from healthy subjects.Conclusions—We conclude that fibroblasts from type 2 diabetes patients are characterized by a hyperactive purinergic loop based either on a higher level of ATP release or on increased P2X7reactivity.
Prosthetic Replacement of the Medial Meniscus in Cadaveric Knees
Authors: Tienen T. G. , Verdonschot N. , Heijkants R. G. J. C. , Buma P. , Scholten J. G. F. , van Kampen A. , Veth R. P. H. 
Published: May 2004

Meniscus replacement by a polymer meniscus prosthesis in dogs resulted in generation of new meniscal tissue. Hypothesis Optimal functioning of the prosthesis would involve realistic deformation and motion patterns of the prosthesis during knee joint motion. Study Design Controlled laboratory study. Methods The movements of the meniscus were determined during knee joint flexion and extension with and without internal and external tibial torque by means of roentgen stereophotogrammetric analysis. Subsequently, the meniscus in 6 human cadaveric knee joints was replaced by a meniscus prosthesis. Results All different parts of the meniscus showed a posterior displacement during knee joint flexion. The anterior horn was more mobile than the posterior horn. The prosthesis mimicked the movements of the meniscus. However, the excursions of the prosthesis on the tibial plateau were less. The knee joint laxity was not significantly higher after replacement with the meniscus prosthesis. Conclusions The prosthesis approximated the behavior of the native meniscus. Improvement in both the gliding characteristics of the prosthetic material and the fixation of the prosthesis may improve the function. Clinical Relevance The meniscus prosthesis needs to be optimized to achieve a better initial function in the knee joint.
Arthroscopic Thermal Shrinkage for Hypermobile Lateral Meniscus
Authors: Ohtoshi Kenichi , Kimura Masashi , Kobayashi Yasukazu , Higuchi Hiroshi , Kikuchi Shinichi 
Published: May 2004

Background The posterior segment of the lateral meniscus is relatively mobile as compared with that of the medial meniscus; that is because of its characteristic anatomy. Abnormal mobility of the lateral meniscus with no obvious rupture can be an unusual cause of knee pain and locking during deep knee flexion. Purpose To evaluate results for a small series of patients with hypermobile lateral meniscus, treated with thermal shrinkage of the supporting ligaments. Study Design Series of case reports. Method Five patients with hypermobile lateral meniscus were identified out of 625 patients who underwent meniscus surgery over a 20-month period. Thermal energy was applied to the peripheral zone of the lateral meniscus until abnormal translation was reduced. The patients were followed up an average of 21 months after the surgery. Results In 4 patients, no recurrence of locking was encountered in the postoperative period. In 1 patient, locking was experienced again 3 months after surgery and meniscal repair was performed. Conclusions Thermal shrinkage can be considered an appropriate treatment in place of subtotal meniscectomy or meniscal repair for hypermobility of the lateral meniscus.
Open versus Closed Kinetic Chain Exercises in Patellofemoral Pain
Authors: Witvrouw Erik , Danneels Lieven , van Tiggelen Damien , Willems Tine Marieke , Cambier Dirk 
Published: May 2004

Background Today, no clinical studies have been undertaken to examine the long-term effects of an open kinetic chain or closed kinetic chain program. Hypothesis The long-term follow-up results after a conservative exercise protocol are significantly worse than the short-term results. The long-term effect of closed kinetic chain training is significantly better compared to the effect of open kinetic chain training. Study Design Prospective randomized clinical trial. Methods Sixty patients were randomized into a 5-week conservative program, consisting of only closed kinetic chain exercises or only open kinetic chain exercises. Assessment of muscular characteristics, subjective symptoms, and functional performance was evaluated in this study at the time of initial physical examination, at the end of the treatment period, and 5 years later. Results At the 5-year follow-up, both groups demonstrated maintenance of good subjective and functional outcomes achieved immediately after the conservative treatment. No significant difference between both groups was observed at the 5-year follow-up for the majority of the examined parameters. However, on 3 of the 18 visual analog scales, the open kinetic chain group showed significantly less complaints compared to the closed kinetic chain group. Conclusions On the basis of these results, the authors conclude that both open kinetic chain and closed kinetic chain programs lead to an equal long-term good functional outcome.
Nontransferrin-bound iron uptake by hepatocytes is increased in the Hfe knockout mouse model of hereditary hemochromatosis
Authors: Chua Anita C. G. , Olynyk John K. , Leedman Peter J. , Trinder Debbie 
Published: May 2004

AbstractHereditary hemochromatosis (HH) is an iron-overload disorder caused by a C282Y mutation in the HFE gene. In HH, plasma nontransferrin-bound iron (NTBI) levels are increased and NTBI is bound mainly by citrate. The aim of this study was to examine the importance of NTBI in the pathogenesis of hepatic iron loading in Hfe knockout mice. Plasma NTBI levels were increased 2.5-fold in Hfe knockout mice compared with control mice. Total ferric citrate uptake by hepatocytes isolated from Hfe knockout mice (34.1 ± 2.8 pmol Fe/mg protein/min) increased by 2-fold compared with control mice (17.8 ± 2.7 pmol Fe/mg protein/min; P &lt; .001; mean ± SEM; n = 7). Ferrous ion chelators, bathophenanthroline disulfonate, and 2′,2-bipyridine inhibited ferric citrate uptake by hepatocytes from both mouse types. Divalent metal ions inhibited ferric citrate uptake by hepatocytes, as did diferric transferrin. Divalent metal transporter 1 (DMT1) mRNA and protein expression was increased approximately 2-fold by hepatocytes from Hfe knockout mice. We conclude that NTBI uptake by hepatocytes from Hfe knockout mice contributed to hepatic iron loading. Ferric ion was reduced to ferrous ion and taken up by hepatocytes by a pathway shared with diferric transferrin. Inhibition of uptake by divalent metals and up-regulation of DMT1 expression suggested that NTBI uptake was mediated by DMT1.
Renal venous thrombosis in neonates: prothrombotic risk factors and long-term follow-up
Authors: Kosch Andrea , Kuwertz-Bröking Eberhard , Heller Christine , Kurnik Karin , Schobess Rosemarie , Nowak-Göttl Ulrike ,   for the Childhood Thrombophilia Study Group
Published: May 2004

AbstractThe present study was designed to evaluate prothrombotic risk profiles in 59 consecutively recruited white neonates with renal venous thrombosis (RVT). The rates of prothrombotic risk factors (PRs)—for example, the factor V (FV) 1691G&gt; A mutation, the factor II (FII) 20210G&gt; A variant, antithrombin (AT), protein C (PC), protein S (PS), elevated lipoprotein(a) (Lp(a)), total fasting plasma homocysteine (tHcy) levels, and anticardiolipin antibodies (ACAs)—were compared with those of 118 healthy control children. At onset, 32 (54.2%) of the 59 neonates showed underlying clinical conditions; 40 (67.8%) of them and 23 (85.2%) of the 27 infants with idiopathic RVT showed at least one PR. Univariate analysis revealed significantly elevated odds ratios/95% confidence intervals (ORs/95% CIs) for FV and Lp(a). Additionally, PC/AT deficiency and ACAs were found significantly more often in the patient group (P = .04). Multivariate analysis calculated significant ORs/95% CIs only for FV (OR, 9.4; 95% CI, 3.3-26.6) and elevated Lp(a) (OR, 7.6; 95% CI, 2.4-23.8). Of the 59 neonates investigated, 53 revealed renal atrophy, and 13 children additionally suffered from severe arterial hypertension. In conclusion, the present study demonstrates the significance of genetic PR—especially the FV mutation and elevated Lp(a)—for the etiology of neonatal RVT.