bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of haemodialysis on QTc dispersion in children
Authors: OZDEMIR DURGUL , MESE TIMUR , AGIN HASAN , CALKAVUR SEBNEM , BAK MUSTAFA
Published: May 2005

Background:  The purpose of the present paper was to investigate the corrected QT (QTc) interval and QTc dispersion value, and the impact of haemodialysis on these parameters in children with chronic renal failure.

Methods:  Nineteen patients with chronic renal failure receiving haemodialysis were included in the present study. Electrocardiography (ECG), echocardiography and serum biochemistry were performed in all patients. Serum electrolyte levels were measured before and after haemodialysis, at the time of the ECG. Nineteen healthy age‐ and sex‐matched children served as the control group.

Results:  Patients with chronic renal failure had greater QTc interval and QTc dispersion compared to control subjects. The patients’ sex, age and presence of hypertension or left ventricular hypertrophy (LVH) were not related to QTc interval/dispersion. However, the patients with left ventricular (LV) systolic dysfunction had significantly greater QTc dispersion value. After haemodialysis session, both QTc interval and QTc dispersion values significantly increased. Serum potassium levels significantly decreased, whereas the calcium level significantly increased after the haemodialysis session. The changes in electrolyte values were not associated with the changes in both QTc interval and QTc dispersion.

Conclusion:  Children receiving haemodialysis may be at greater risk of ventricular arrhythmia and sudden death because QTc dispersion reflects heterogeneous recovery of ventricular excitability.
Efficacy of a non‐vancomycin‐based peritoneal dialysis peritonitis protocol
Authors: TOUSSAINT NIGEL , MULLINS KIM , SNIDER JONATHON , MURPHY BRENDAN , LANGHAM ROBYN , GOCK HILTON
Published: May 2005

Background:  Peritonitis has a significant impact upon morbidity and mortality of peritoneal dialysis (PD) patients. Gram‐positive organisms account for the majority of infections and vancomycin is a cost effective broad‐spectrum antimicrobial treatment for PD peritonitis, but this may lead to the emergence of multiple antibiotic‐resistant organisms. The purpose of the present paper was to evaluate the efficacy of a non‐vancomycin‐based protocol comprising cephazolin and gentamicin, which was introduced in the present PD population as empirical treatment for peritonitis.

Methods:  The study involved 82 peritonitis episodes over a 4‐year period in 58 patients, excluding those with previous methicillin‐resistant staphylococcal peritonitis.

Results:  With cephazolin and gentamicin there was no apparent difference in response or relapse rates in comparison to reported studies using vancomycin‐based first‐line therapy protocols.

Conclusion:  We advocate initial treatment of PD peritonitis with non‐vancomycin‐based therapy given similar efficacy and the potential for reduction of resistant organisms.
Prediction of failure of native arteriovenous fistulas using ‘on‐line’ fistula flow measurements
Authors: TREACY P JOHN , RAGG JOE L , SNELLING PAUL , LAWTON PAUL , LAMMI HELEN
Published: May 2005

Background:  Measurement of blood flow within native arteriovenous fistula during haemodialysis is recommended to detect incipient fistula failure. In the present study the value of such flow measurements was assessed in a group of patients on maintenance haemodialysis, with access via native arteriovenous fistulas.

Methods:  Flow was measured using the ‘on‐line’ thermodilution technique, on three separate occasions, and correlated with subsequent fistula failure within 6 months.

Results:  Of the 53 patients studied, there were six failures (three thromboses and three inadequate dialysis filtration rates). Flow rates in patients who progressed to fistula failure were significantly less than flow rates in patients whose fistulas did not fail (U = 13.0, P < 0.0003). Failure was no more common in one type of fistula than another (type fistula: F = 0.29, P = 0.88; flow predicting failure: F = 7.22, P = 0.010). Receiver operating characteristic (ROC) curve analyses confirmed flow measurement to be a useful predictor of fistula failure (area under ROC curve 0.91). The optimal threshold of 576 mL/min flow gave a sensitivity of 89% and a specificity of 81%. Measurement of access resistance was less useful in predicting failure (area under ROC curve 0.87). Measurement of fall in flow from the previous measurement was of no use (area under ROC curve 0.535).

Conclusion:  On‐line thermodilution measurement of flow within established native arteriovenous fistula is useful in surveillance and early prediction of fistula failure. Fistula flow <576 mL/min may indicate incipient native fistula failure, and should prompt further investigation.
Effect of intravenous iron on haemodialysis catheter microbial colonization and blood‐borne infection
Authors: BREWSTER URSULA C , COCA STEVEN G , REILLY ROBERT F , PERAZELLA MARK A
Published: May 2005

Background:  Intravenous (i.v.) iron is employed to treat absolute and relative iron deficiency in end‐stage renal disease patients. However, there exists the possibility that i.v. iron increases infection risk. This pilot study examines whether i.v. iron gluconate acutely increases tunnelled haemodialysis catheter colonization, microbial growth, or blood‐borne infection.

Methods:  Nineteen patients with haemodialysis catheters who met criteria to receive an i.v. iron load entered the study. Six matched patients with catheters who did not receive iron were controls. Blood aspirated from the catheter prior to initiation of haemodialysis was sent for qualitative/quantitative cultures. The study consisted of three baseline cultures, five cultures during iron (125 mg of ferric gluconate per treatment), and three cultures following iron administration. Patients were monitored for infection for 30 days following iron.

Results:  Fifteen iron‐treated patients and six controls completed the study. Thirty‐three per cent of treated patients were colonized at baseline; 66% were colonized following iron. Thirty‐three per cent of controls (2/6) were colonized at baseline; no new colonization developed during follow up. Neither treated patients nor controls had significant microbial growth within catheters; one patient in the iron‐treated group developed candidaemia.

Conclusion:  Intravenous iron is not associated with acute microbial growth in catheters or clinical infection. However, a trend towards increased catheter colonization following iron administration exists.
Randomized cross‐over comparison of intravenous and subcutaneous darbepoetin dosing efficiency in haemodialysis patients
Authors: CERVELLI MATTHEW J , GRAY NICHOLAS , MCDONALD STEPHEN , GENTGALL MELANIE G , DISNEY ALEX PS
Published: May 2005

Background:  Studies have consistently shown the superior dosing efficiency of subcutaneous (s.c.) compared to intravenous (i.v.) erythropoietin (r‐HuEPO). Unlike r‐HuEPO, data from pivotal darbepoetin trials support s.c. and i.v. dosing equivalence, however, no blinded cross‐over randomized studies of s.c. and i.v. dose efficiency or intra‐patient variability in response have been published.

Methods:  During this 12‐month study, 53 haemodialysis patients were randomized to s.c. or i.v. darbepoetin for a 6‐month period and then switched to the alternative route for a second 6‐month period. Darbepoetin dose was titrated during the first 4‐months of each period to acheive a stable haemoglobin during the final 2‐month observation period of each arm.

Results:  Twenty‐four patients were included in analysis. No significant difference between s.c. and i.v. administration was observed for any measured parameter. Patients acheived a non‐significantly higher haemoglobin (123.6 ± 3.76 vs 120.9 ± 4.42 g/L, P = 0.11) from a non‐significantly lower darbepoetin dose (40.8 ± 10.7 vs 42.5 ± 11.0 mcg/week, P = 0.23) with i.v. administration. The population‐based weight normalized s.c./i.v. dose ratio was 1.04 (0.97–1.11). Despite no significant overall difference, some patients experienced changes in individual dose efficiency response. Three of 24 patients recorded a greater than 30% change, four of 24 recorded between a 20 and 30% change, and five of 24 patients recorded between a 10 and 20% change relative to i.v. dose efficiency.

Conclusions:  This study further supports s.c. and i.v. dosing equality and that overall the more convenient i.v. route can be used with equal dosing efficiency. However, patients switching routes of administration should be monitored due to the wide range in individual response.
Heparanase inhibition reduces proteinuria in a model of accelerated anti‐glomerular basement membrane antibody disease
Authors: LEVIDIOTIS VICKI , FREEMAN CRAIG , TIKELLIS CHRIS , COOPER MARK E , POWER DAVID A
Published: May 2005

Background:  The β‐ d‐endoglycosidase, heparanase, is emerging as an important contributor to the pathogenesis of proteinuria. The purpose of the present study therefore was to examine the role of heparanase in a model of accelerated anti‐glomerular basement disease (anti‐GBM).

Methods:  Accelerated anti‐GBM disease was induced and animals sacrificed at day 10 to establish heparanase expression using immunohistochemistry and western blot analysis. In addition, cortex was isolated from normal and diseased glomeruli to determine if mRNA levels altered with disease. A previously validated anti‐heparanase antibody associated with proteinuria reduction, in a model of membranous nephropathy, was administered prior to disease induction to establish its impact on protein excretion in this model.

Results:  At day 10 of anti‐GBM disease, an increase in glomerular heparanase was shown using immunohistochemistry. Sequential staining studies revealed that this increase was associated with glomerular endothelial, epithelial cells and invading ED‐1‐positive inflammatory cells. RT‐PCR revealed an insignificant 1.2‐fold induction of mRNA at day 10 of disease. Western blot analysis of kidney cortex confirmed that the active 58‐kDa heparanase species was restricted to diseased kidney at day 10. The inactive 65‐kDa precursor, however, was found only in cortex derived from normal kidney. Proteinuria at day 10 of disease was significantly reduced, in the absence of altered rat anti‐sheep antibody titres, after administration of a validated polyclonal anti‐heparanase antibody (P < 0.05). Furthermore, sheep IgG deposition was not altered by administration of the anti‐heparanase antibody.

Conclusion:  These data suggest that heparanase contributes to the pathogenesis of proteinuria in a model of anti‐GBM disease.
QT interval dispersion in dialysis patients
Authors: WU VIN‐CENT , LIN LIAN‐YU , WU KWAN‐DUN
Published: May 2005

SUMMARY:  The leading cause of mortality in dialysis patients is cardiovascular complications, including ventricular arrhythmias and sudden cardiac death. A reliable non‐invasive predictive test of sudden death is therefore important. The interlead variation in duration of the QT interval on the surface electrocardiogram corrected with heart rate (QTc dispersion) might serve as a surrogate for ventricular arrhythmia. Prolonged QTc dispersion is commonly encountered in dialysis patients and possesses an increased risk of all mortality, including cardiovascular mortality. QT dispersion might be affected by shifts of the intracellular electrolytes during dialysis and increasing deposition of iron in cardiac muscles in these patients who have underlying heart diseases. Although no well‐designed study has been done, the factors contributing to prolongation of QTc dispersion should be avoided. We summarize the results of the currently available clinical studies that examined QTc dispersion in dialysis patients.
Immunohistochemical study on so‐called follicular cells and folliculostellate cells in the human adenohypophysis
Authors: Yamashita Michiko , Qian Zhi Rong , Sano Toshiaki , Horvath Eva , Kovacs Kalman
Published: May 2005

Non‐hormone‐secreting cells in human adenohypophysis have been designated as either follicular cells (FC) or folliculostellate cells (FSC). They have similarly long cytoplasmic processes, and the difference between FC and FSC remains unclear. An immunohistochemical study for S‐100 protein, cytokeratin (CK, detected by AE1/AE3) and glial fibrillary acidic protein (GFAP) was performed in autopsy pituitaries. Double immunohistochemistry for S‐100 protein and CK revealed that there were numerous coexpressed cells. The most frequent type (‘CK‐type cell’) was cells weakly positive for S‐100 protein in the nucleus and for CK‐immunoreactivity in the cytoplasm. The next numerous type (‘S‐100 protein cell’) was cells strongly positive for S‐100 protein and weakly positive or negative for CK. The CK‐type cells were frequently observed in the vicinity of follicular structures and in neighborhood of adrenocorticotropic hormone ‐immunoreactive cells, and were most likely the cells termed FC. They were often observed around necrotic areas. The S‐100 protein cells were individually found in the circumference of endocrine cell nest, and seemed to be the so‐called stellate cells. GFAP‐positive cells were rare. It is implied that S‐100 protein‐positive FSC could be divided into at least two main subtypes: FC (CK‐type cells) and stellate cells (S‐100 protein cells).
Utility of cytokeratin 20 and Ki‐67 as markers of urothelial dysplasia
Authors: Kunju Lakshmi P. , Lee Cheryl T. , Montie James , Shah Rajal B.
Published: May 2005

Reactive urothelial atypia (RUA) can be difficult to differentiate from dysplastic urothelium. The goal was to evaluate the efficacy of cytokeratin 20 (CK20), Ki‐67 and E‐cadherin (E‐Cad) in this regard. Fifty carcinoma in situ (CIS) cases, 50 non‐neoplastic urothelia (25 normal, 25 reactive urothelial atypia (RUA)) and 17 atypia of unknown significance (AUS) cases were evaluated. All cases were stained with monoclonal antibodies against Ki‐67, CK20 and E‐Cad. All (100%) normal urothelia showed normal staining patterns. In the CIS group, 86%, 82% and 20% of cases showed abnormal expression with CK20, Ki‐67 and E‐Cad, respectively. Both Ki‐67 and CK20 were positive in 68% of cases. In the RUA group, 96%, 72% and 100% of cases showed normal expression patterns with CK20, Ki‐67 and E‐Cad, respectively. Of 28% RUA cases with increased Ki‐67, none demonstrated abnormal CK20 or E‐Cad expression. In the AUS group, 47% demonstrated abnormal CK20 and increased Ki‐67 expression, suggestive of urothelial dysplasia/CIS, 29% were negative with both, suggestive of RUA, and the remaining 24% cases could not be resolved. In summary, abnormal CK20 is a useful adjunct to morphology for confirming dysplasia. Ki‐67 by itself is a less reliable marker of dysplasia. E‐Cad is not a useful marker in this setting.
Vascular endothelial growth factor mRNA levels quantified by reverse transcription–polymerase chain reaction in microdissected breast carcinoma tissues are correlated with histological type and grade of both invasive and intraductal components
Authors: Yamasaki Tamio , Tsuda Hitoshi , Imazeki Nobuo , Matsubara Osamu
Published: May 2005

In breast cancer, vascular endothelial growth factor (VEGF) is a prognostic factor, but the relationship of VEGF mRNA levels with various parameters or tumor progression is unclear. VEGF mRNA levels were measured in 48 cases of invasive ductal carcinoma by using laser capture microdissection and quantitative reverse transcription–polymerase chain reaction (RT‐PCR). The mean VEGF mRNA levels were compared among different histological types and grades in 41 and 29 samples of invasive and intraductal components, respectively. VEGF mRNA levels were always higher in cancerous cells than in non‐cancerous cells, but mean VEGF mRNA levels were not significantly different between invasive component (3.24 ± 3.18‐fold the value of non‐cancerous tissue) and intraductal component (4.14 ± 4.43‐fold). They were higher in papillotubular type than in other types, and higher in grade 2 carcinomas than in grade 3 carcinomas of invasive component, and higher in comedo type than in other types of intraductal component. Mean VEGF mRNA levels were higher in the VEGF‐immunopositive group than in the VEGF‐immunonegative group. There was no correlation between VEGF mRNA levels and tumor size, nodal status, or hormone receptor status. VEGF expression may play an important role in the development of both invasive and intraductal carcinoma components, especially those carcinoma components of less aggressive histological features.
Neuroendocrine carcinoma of the posterior mediastinum arising from a foregut cyst
Authors: Yamashita Atsushi , Marutsuka Kousuke , Moriguchi Sayaka , Shimizu Tetsuya , Matsuzaki Yasunori , Onitsuka Toshio , Asada Yujiro
Published: May 2005

Neuroendocrine carcinoma of the posterior mediastinum is extremely rare. Described here is a patient with neuroendocrine carcinoma of the posterior mediastinum arising from a foregut cyst. A paravertebral mass detected in the posterior mediastinum of a 64‐year‐old man was spherical, solid and yellowish white. Some cystic or cleft‐like spaces were present. Microscopically, the lesion was composed of proliferating round or polygonal tumor cells in a diffuse, solid or trabecular fashion with extensive necrosis and high mitotic activity. Components of glandular epithelia and smooth muscle layers were evident in the cystic wall. Immunohistochemically, the tumor cells were positive for both epithelial and neuroendocrine markers, including pan‐cytokeratin, chromogranin A and synaptophysin. Neuroendocrine marker‐positive cells were also present in the glandular epithelium of the cystic walls. It was considered that posterior mediastinal neuroendocrine carcinoma arose from a foregut cyst. Malignant change within a foregut cyst is very uncommon. This is the first report of a neuroendocrine carcinoma of the posterior mediastinum arising from a foregut cyst.
Berry splenic artery aneurysm rupture in association with segmental arterial mediolysis and portal hypertension
Authors: Imai Miwa Akasofu , Kawahara Ei , Katsuda Shogo , Yamashita Tatsuya
Published: May 2005

A rare case of berry splenic artery aneurysm (SAA) rupture associated with segmental arterial mediolysis (SAM) and portal hypertension is reported. A 66‐year‐old woman, diagnosed as having liver cirrhosis and portal hypertension 6 years earlier, suddenly developed a lancinating pain in the upper abdomen and lost consciousness. She recovered consciousness while being transferred to hospital by ambulance. During the investigations, her level of consciousness suddenly deteriorated. Ultrasonography showed a massive intraperitoneal hemorrhage, and she died 5½ h after admission. On gross examination at autopsy it was not possible to find the rupture point of the vessel because the pancreas was embedded in a massive hematoma. However, careful dissection of the pancreatic tail after fixation revealed a berry aneurysm measuring 0.8 cm in diameter in a branch adjacent to the bifurcation in the distal third of the main splenic artery. Microscopic examination detected a rupture of the aneurysm. The histology of the arterial wall proximal to the aneurysm showed typical SAM. In general, berry SAA caused by SAM is rare and unlikely to rupture. The SAA in the present case likely occurred and ruptured due to the combination of SAM and portal hypertension.
A new strategy for the chemical control of fig longicorn, Acalolepta vastator (Newman) (Coleoptera: Cerambycidae), infesting grapevines
Authors: Goodwin Stephen
Published: May 2005

Abstract  Difficulties in controlling the grapevine borer pest fig longicorn, Acalolepta vastator, were experienced. Variable results with azinphos‐methyl, chlorpyrifos and methidathion applied as seasonal sprays at 2‐weekly or monthly intervals, coupled with inconsistent grower spraying practices, provided unreliable control. Pest resurgence resulted in a range of new chemicals and usage strategies being tested to overcome the problem. After extensive trialling an effective strategy for control of A. vastator was developed. This involved a single application of insecticide at dormancy, and after vineyard pruning, at a much higher rate than that normally registered for crop use. Bifenthrin (Talstar 100 EC) at 1000 mL/100 L, fipronil (Regent 200 SC) at 100 mL/100 L and imidacloprid (Confidor 350 SC) at 200 mL/100 L controlled emerging adults and young. This strategy overcomes a number of problems experienced with the previous chemical application method for this pest.
Species composition and population dynamics of leafmining flies and their parasitoids in Victoria
Authors: Bjorksten Tracey A , Robinson Michelle , La Salle John
Published: May 2005

Abstract  Mined leaves were sampled from unsprayed sites in Victoria to record the range of leafminers and their parasitoids. Three agromyzid leafminers, Liriomyza brassicae (Riley), Liriomyza chenopodii (Watt) and Chromatomyia syngenesiae Hardy, and one drosophilid leafminer, Scaptomyza flava (Fallén), were collected, along with 15 parasitoids, mainly Eulophidae. The most common parasitoids were Hemiptarsenus varicornis (Girault) (42.5%), Diglyphus isaea (Walker), 14.6%, Closterocerus mirabilis Edwards & La Salle (10.5%), and Opius cinerariae Fisher (8.5%). Most parasitoids were collected from two or more leafminer hosts. Weekly collections from Chinese cabbage (Brassica rapa var. pekinensis) infested with L. brassicae and S. flava, and beetroot (Beta vulgaris var. crassa) infested with L. chenopodii were made over two seasons at Knoxfield, Victoria to assess the relative impact of these parasitoids on agromyzid fly populations in crops. A further two parasitoid species were identified at low densities. Hemiptarsenus varicornis and D. isaea were the most numerous parasitoids collected in both crops. A different sampling method in the second year showed that O. cinerariae made up 25% of the sample from Chinese cabbage and was probably more common than estimated in the first season. Control exerted by local parasitoids was high, with 100% control of L. chenopodii reached in beets within 1–3 weeks of mines appearing and 100% control of L. brassicae within 6 weeks.
Interactions between dung beetles (Coleoptera: Scarabaeidae) and the arbovirus vector Culicoides brevitarsis Kieffer (Diptera: Ceratopogonidae)
Authors: Bishop Alan L , McKenzie Harry J , Spohr Lorraine J , Barchia Idris M
Published: May 2005

Abstract  The potential for dung beetles to reduce populations of the biting midge and arbovirus vector Culicoides brevitarsis in bovine dung was studied in the Hunter Valley, New South Wales (NSW) between 1999 and 2003 using natural populations of insects. Preliminary work to develop experimental procedures showed that: a few C. brevitarsis could survive in buried dung; dung beetles and C. brevitarsis coming to dung were unaffected by a background of shade‐cloth used experimentally to prevent dung burial; the most abundant dung beetle, Onthophagus gazella L. and C. brevitarsis oviposition occurred concurrently in the first 2 d after dung deposition, and the potential for interaction between dung beetles and C. brevitarsis was greatest in open pasture adjacent to trees where cattle congregate at night. Laboratory experiments on dung burial showed that C. brevitarsis numbers decreased as numbers of dung beetles increased or as the dry weight of dung decreased due to burial. This was seldom reflected in the field where, although significant burial occurred experimentally in 9 of 20 trials over 3 years, a significant decline in C. brevitarsis numbers attributable to burial only occurred once. C. brevitarsis numbers in the field were lower in unburied dung in 70% of trials. Differences were significant twice and were considered the result of dung disturbance. In the laboratory, decreasing numbers of C. brevitarsis were related to three characteristics of disturbance: the flattening, spreading and reduction in wet weight of the dung. Evidence of C. brevitarsis activity throughout coastal NSW suggests that, while C. brevitarsis numbers may be modified by dung beetles, the interaction is insufficient to prevent their increase, spread and ability to transmit viruses to livestock.
One new genus and three new species of Orsillinae (Hemiptera: Lygaeidae) from Australia
Authors: Malipatil MB
Published: May 2005

Abstract  Two new species of Nysius Dallas, N. orarius sp. n. and N. tasmaniensis sp. n. are described from New South Wales and Tasmania (Australia), respectively. A new monotypic genus, Reticulatonysius, with type‐species R. queenslandensis sp. n. is described from Queensland, and its systematic relationship with other orsilline genera is discussed.
Potential non‐target impact of Microctonus aethiopoides Loan (Hymenoptera: Braconidae) on Cleopus japonicus Wingelmüller (Coleoptera: Curculionidae), a biocontrol agent for putative release to control the butterfly bush Buddleja davidii Franchet in New Zealand
Authors: McNeill Mark R , Withers Toni M , Goldson Stephen L
Published: May 2005

Abstract  Cleopus japonicus Wingelmüller (Coleoptera: Curculionidae) is being considered for release to control buddleia Buddleja davidii in New Zealand. As part of the pre‐release testing, Moroccan and Irish biotypes of the solitary endoparasitoid Microctonus aethiopoides Loan (Hymenoptera: Braconidae) were evaluated for potential non‐target impacts on adult C. japonicus should release occur. Laboratory experiments evaluated both the behavioural and physiological suitability of C. japonicus to both biotypes of the parasitoid. Parasitoid behavioural attraction was assessed using the pathenogenic bacterium Serratia marcescens (Enterobactereaceae), as an indicator of ovipositor penetration. Physiological suitability was assessed by comparing parasitism of C. japonicus with the natural hosts of the respective parasitoid biotypes. The parasitoid‐bacteria study showed that C. japonicus was behaviourally acceptable to both Moroccan and Irish M. aethiopoides, with the two experiments producing 34% and 8% mortality, respectively. Cleopus japonicus did not support development of either Moroccan or Irish M. aethiopoides biotypes. None of the weevils dissected at the end of the experiment contained immature parasitoids. Comparison between unexposed and parasitoid‐exposed C. japonicus found no difference in premature mortality during the experiment nor in the number of fully reproductive females at its conclusion. The results of this study predict that should C. japonicus be released, the potential impact of M. aethiopoides on field populations will be negligible.
Evolution of nest‐weaving behaviour in arboreal nesting ants of the genus Polyrhachis Fr. Smith (Hymenoptera: Formicidae)
Authors: Robson Simon K A , Kohout Rudolf J
Published: May 2005

Abstract  Polyrhachis ants represent one of the most taxonomically and ecologically diverse ant genera, with over 500 described species organised into 12 subgenera. Nesting habits range from subterranean localities to arboreal nests incorporating silk produced by the ants’ own larvae (nest weaving). In this article, we combine scanning electron microscopy and gross observations of the nests of 35 species representing nine subgenera thought to contain individuals that nest above the ground (Cyrtomyrma, Hagiomyrma, Hedomyrma, Hemioptica, Myrma, Myrmatopa, Myrmhopla, Myrmothrinax, Polyrhachis) to revaluate the relationship between nest locale, the type of nest material used and the use of larval silk for nest construction. Nesting habits are highly diverse, ranging from truly arboreal nests on or between leaves and branches, to lignicolous nests inside hollow stems or bamboo internodes and lithocolous nests on the sides of rock walls. Flat sheets of larval silk are used only by arboreal nesting species within the subgenera Cyrtomyrma, Hemioptica, Myrma, Myrmatopa, Myrmothrinax and Polyrhachis. Lignicolous nesting habits were demonstrated predominantly by Hedomyrma spp., but these habits also occur in Myrma and Myrmhopla. Lithicolous nesting habits occur within Hagiomyrma and Hedomyrma, though the actual nesting material used can be either carton or dense masses of spider silk. Based on existing phylogenetic hypotheses, the use of larval silk for nest construction has evolved independently within the genus, and has evolved independently of the construction of silk nests per se. Further examination of the exact type of silk found in the colonies of ‘nest‐weaving’Polyrhachis is warranted.
Using geometric morphometrics to investigate wing dimorphism in males and females of Hymenoptera – a case study based on the genusTachysphexKohl (Hymenoptera: Sphecidae: Larrinae)
Authors: Pretorius E
Published: May 2005

Abstract The shape of an organism and variation among related groups lies at the core of understanding evolution and interactions between phenotype, genotype and environmental spaces. Traditional morphometrics, used in the study of shape, are currently complimented by an additional statistical method, geometric morphometrics. This technique is based on the quantification of shape usingx,ycoordinates or landmarks. Important features of this technique are obtaining an exact geometric description of the differences or similarities of a biological structure, as well as the ease in visually determining exactly which landmarks are responsible for differences/similarities. The current study investigates the amount of variation between the forewings of males and females of 24 species in the genusTachyspex(Hymenoptera). Wing morphology and its diversity have been used frequently in taxonomic as well as systematic studies of insects and most groups can be identified based solely on the morphology of one wing. This research also aims to investigate the extent of the morphological similarities/differences between males and females of the same species, in order to make recommendations regarding inclusion of both males and females in a systematic or geometric morphometrics study. Mantel statistics revealed a good correlation between the male and female data set; however, Hotelling'st‐test and canonical variates analyses (using the Integrated Morphometric Package) indicated that there were indeed significant differences between the two data sets. Although visual analysis of the relative warp analysis plots of the two sexes indicated significant correlations between sexes of the same species, differences in the position of the clusters (or species) on the plots suggests that sexual dimorphism in wings are present. Results from the thin‐plate spline analysis of the mean shape of the male and female data set revealed which landmarks are responsible for the differences. It is concluded that, in an analysis of members of a genus, only one of the sexes be used in the analysis, as small‐scale differences may influence the results.
Management of thrips (Thysanoptera: Thripidae) in Australian strawberry crops: within‐plant distribution characteristics and action thresholds
Authors: Steiner Marilyn Y , Goodwin Stephen
Published: May 2005

Abstract  Management of thrips in a hydroponic strawberry crop near Sydney, New South Wales, was studied from 1999 to 2002. The main species present were western flower thrips, Frankliniella occidentalis (Pergande), plague thrips, Thrips imaginis Bagnall, and, occasionally, onion thrips, Thrips tabaci Lindeman. Their within‐ and between‐plant distribution and the degree and type of damage caused are described, and used to recommend action thresholds. Flowers are identified as the primary monitoring site, and young green fruit as the key damage site. Action thresholds of approximately 45% of flowers with 5 or more adult western flower thrips, or 40% of flowers with 10 or more adult plague thrips are recommended. Alternative thresholds using all motile stages are given for flowers, and for young green and red berries. A higher tolerance is recommended during cool, wet periods.
Non‐propagating crack behaviour at giga‐cycle fretting fatigue limit
Authors: KONDO Y. , SAKAE C. , KUBOTA M. , YANAGIHARA K.
Published: May 2005

Fretting fatigue fracture of industrial machines is sometimes experienced after a long period of operation. It has been a question whether the fatigue limit which means infinite life really exists in fretting fatigue or not. Fretting fatigue tests in ultra high cycle region up to 109 cycles were performed. Test results showed that the S‐N curve had a knee point around 2 × 107 cycles and a clear fatigue limit was observed in the giga‐cycle regime for partial slip conditions. An electropotential drop technique was applied to detect the crack growth behaviour under the contact pad. The real‐time measurement of crack depth during the fretting fatigue test at the fatigue limit showed that a crack initiated at an early stage and then ceased to grow after 2 × 107 cycles and the crack became a non‐propagating crack. These results indicated that the fatigue limit exists in fretting fatigue and infinite endurance is achieved by the mechanism of forming a non‐propagating crack.
Numerical life estimation after fatigue failure of a complex component
Authors: OTEGUI J. L. , LÓPEZ MONTENEGRO H. , MÁRQUEZ A. A.
Published: May 2005

Failure of a large ethylene‐reciprocating compressor was found to be due to fatigue growth of cracks in the crosshead of one of the cylinders, initiated at material defects near stress raisers. Total fatigue crack growth time was required in order to identify the cause of the failure. The applied stress field near the initiation sites and along fatigue path was estimated using FEM. The stresses were found to vary steeply and become partly compressive along a large part of the fatigue crack path. A weight function based on numerical method was developed, which was able to predict exactly the shape of the crack front during propagation. Fatigue crack initiation was traced to a disassembly 6 months before final failure. This failure was found to be jointly the result of non‐conformities in manufacture and maintenance.
Experimental results and finite‐element predictions of the effect of nut geometry, washer and Teflon tape on the fatigue life of bolts
Authors: MAJZOOBI G. H. , FARRAHI G. H. , HARDY S. J. , PIPELZADEH M. K. , HABIBI N.
Published: May 2005

The effect of nut geometry, curved spring washer and a sealing material (Teflon tape) on the fatigue life of M12 and M16 ISO bolts was investigated. This was accompanied by the study of the axial and bending stress distribution in threads by numerical simulation of bolt and nut connections using the finite‐element method. The experimental results showed that the highest fatigue life is achieved for a slotted tapered nut. The presence of a spring washer also increases the fatigue life, providing that the correct tightening torque is applied to produce a pretension in the bolt. The use of Teflon tape as a filling material between engaging threads of the bolt and nut is shown to significantly increase the fatigue life. On the whole, the highest fatigue life is obtained for a slotted tapered nut using washer. Four fracture mechanisms were observed for bolt–nut connections during the fatigue tests.
Osteoprotegerin and bone turnover markers in heavily pretreated HIV‐infected patients
Authors: Seminari E , Castagna A , Soldarini A , Galli L , Fusetti G , Dorigatti F , Hasson H , Danise A , Guffanti M , Lazzarin A , Rubinacci A
Published: May 2005

Objectives

To characterize osteoprotegerin (OPG) levels, bone remodelling and bone mineral density (BMD) in heavily pretreated HIV‐infected patients on antiretroviral therapy, and to evaluate the clinical factors associated with bone density decline.

Methods

Heavily pretreated (>5 years) HIV‐positive patients were enrolled in this cross‐sectional, observational study, which was based on a total body bone densitometry examination and a comprehensive evaluation of bone and mineral parameters.

Results

Sixty‐eight patients (55 male and 13 female) with a median age of 41 years (range 25–60 years) were included in the study. Their antiretroviral treatment lasted for 82 months. On the basis of the World Health Organization criteria, nine patients (13.2%) were osteoporotic [T‐score<−2.5 standard deviation (SD)] and 19 patients (27.9%) were osteopenic (T‐score between−1 and−2.5). The principal outcomes associated with the presence of a low BMD were high OPG and lysylpyridinoline/creatinine ratio (Dpd) values. Most of the patients (39 of 48; 81.25%) showed vitamin D insufficiency [Vitamin D (25(OH)D)<18 ng/mL] with secondary hyperparathyroidism (13 of 50 patients: 26%), which proved to be correlated to osteocalcin (BGP) levels [parathyroid hormone (PTH) vs. BGP: r=0.34; P<0.01]. There was an inverse correlation between T‐scores and serum osteocalcin and alkaline phosphatase (AP) levels, on one hand, and Dpd, on the other. High AP and Dpd values were associated with relative risks of 4.1 [95% confidence interval (CI)=1.01–17.6] and 7.2 (95% CI=1.67–31.03), respectively, of a pathological T‐score. Multivariate analysis revealed that the factors associated with the presence of osteopenia or osteoporosis were older age and lower body mass index.

Conclusions

About 40% of our heavily pretreated subjects with advanced HIV infection had a low BMD, and 56% (24 of 44 patients) showed a high bone turnover rate with marked osteoclast activation. High OPG levels may protect against bone resorption.
Antiretroviral treatment change among HIV, hepatitis B virus and hepatitis C virus co‐infected patients in the Australian HIV Observational Database
Authors: Petoumenos K , Ringland C ,   on behalf of the Australian HIV Observational Database
Published: May 2005

Objectives

To assess the impact of highly active antiretroviral therapy (HAART) on rates of change of antiretroviral treatment among patients co‐infected with hepatitis B virus (HBV) and/or hepatitis C virus (HCV) in the Australian HIV Observational Database (AHOD).

Methods

Analysis was based on 805 of the 2218 patients recruited to the AHOD by March 2003, who had commenced HAART after 1 January 1997, who had recorded test results for HBV surface antigen and anti‐HCV antibody, and who had follow‐up of more than 3 months. The effect of hepatitis co‐infection on the rate of antiretroviral treatment change after commencing HAART was assessed using a random‐effect Poisson regression model.

Results

Among those included in the analyses, the prevalences of HBV and HCV were 4.8% and 12.8%, respectively. The overall rate of combination antiretroviral treatment change was 0.74 combinations per year. Factors independently associated with an increased rate of change of combination antiretroviral treatment were: prior AIDS‐defining illness; prior exposure to double combination antiretroviral therapy; and antiretroviral treatment class. Co‐infection with HBV and/or HCV was not found to be significantly associated with the rate of combination antiretroviral treatment change.

Conclusions

While both HBV and HCV co‐infections are relatively common in the AHOD, they do not appear to be serious impediments to the treatment of HIV‐infected patients.
The Protease Inhibitor Transfer Study (PROTRA 1): abacavir and efavirenz in combination as a substitute for a protease inhibitor in heavily pretreated HIV‐1‐infected patients with undetectable plasma viral load
Authors: Bickel M , Rickerts V , Stephan C , Jacobi V , Rottmann C , Dauer B , Carlebach A , Thalhammer A , Miller V , Staszweski S
Published: May 2005

Objectives

The aim of the study was to evaluate the safety and efficacy of abacavir (ABC) and efavirenz (EFV) instead of a protease inhibitor (PI) in HIV‐1‐infected subjects treated with two nucleoside reverse transcriptase inhibitors (NRTIs) and one PI with undetectable viral loads (<50 HIV‐1 RNA copies/mL). To be eligible for inclusion, patients had to have a history of viral load <400 copies/mL for at least 3 months and had to be naïve to treatment with nonnucleoside reverse transcriptase inhibitors (NNRTIs) and ABC, but multiple pretreatment and treatment failure were allowed.

Design

An open‐label, single‐centre pilot study of duration 48 weeks was conducted. ABC was added to the original treatment with two NRTIs and one PI at baseline, and at week 6 the PI was replaced by EFV. At each study visit, CD4 cell count, viral load [measured by polymerase chain reaction (PCR)] and clinical chemistry were measured. Fasting blood samples were taken at baseline and at weeks 12, 24, 36 and 48 to measure levels of cholesterol [high‐density lipoprotein (HDL)/low‐density lipoprotein (LDL)], triglycerides, insulin and C‐peptide. Additionally, an oral glucose tolerance test (OGTT) was performed. A bioelectric impedance analysis (BIA) and a single slice abdominal and mid‐thigh computed tomography (CT) scan were carried out to assess changes in body composition.

Results

Thirty patients were included in the study. Three patients experienced ABC‐hypersensitivity and one patient demonstrated virological failure caused by nonadherence. At week 48, all remaining patients had viral loads <50 copies/mL with stable CD4 counts. The fasting metabolic parameters and abdominal fat distribution remained unchanged.

Conclusions

In heavily pretreated patients, ABC and EFV in combination provide an effective, simplified and well‐tolerated alternative to PI treatment.
Prevalence of hepatitis C in an ethnically diverse HIV‐1‐infected cohort in south London
Authors: Mohsen AH , Murad S , Easterbrook PJ
Published: May 2005

Objectives

There is limited information on the prevalence of and risk factors for hepatitis C virus (HCV) infection among HIV‐1‐infected patients in the UK. Our objective was to determine the prevalence of HCV infection among an ethnically diverse cohort of HIV‐infected patients in south London, and to extrapolate from these data the number of co‐infected patients in the UK.

Methods

A total of 1017 HIV‐1‐infected patients who had attended King's College Hospital HIV clinic between September 2000 and August 2002 were screened for HCV antibody using a commercial enzyme‐linked immunosorbent assay (ELISA). Positive results were confirmed by polymerase chain reaction (PCR) or recombinant immunoblot assay. Demographic, clinical and laboratory data were obtained from the local computerized database and medical records. We applied our HCV prevalence rates in the different HIV transmission groups to the estimated number of HIV‐infected persons in these groups in the UK, to obtain a national estimate of the level of HIV‐HCV co‐infection.

Results

Of the 1017 HIV‐1‐infected patients, 407 (40%) were white men, 158 (15.5%) were black African men, 268 (26.3%) were black African women, and 61 (6%) and 26 (2.6%) were black Caribbean men and women, respectively. Heterosexual exposure was the most common route of HIV acquisition (53.5%), followed by men having sex with men (36.9%), and current or previous injecting drug use (IDU) (7.2%). The overall prevalence of HCV co‐infection was 90/1017 (8.9%), but this varied substantially according to route of transmission, from 82.2% among those with a history of IDU (which accounted for 67% of all HCV infections), to 31.8% in those who had received blood products, to 3.5% and 1.8% in those with homosexually and heterosexually acquired infection, respectively. Multivariate logistic regression analysis identified several independent risk factors for HCV infection: a history of IDU [odds ratio (OR)=107.2; 95% confidence interval (CI)=38.5–298.4], having received blood products (OR=16.5; 95% CI=5.1–53.7), and either being from a white ethnic group (OR=4.3; 95% CI=1.5–12.0) or being born in Southern Europe (OR=6.7; 95% CI=1.5–30.7). Based on the 35 473 known HIV‐1‐infected persons in the UK and the 10 997 estimated to be unaware of their status, we projected that there are at least 4136 HIV‐HCV co‐infected individuals in the UK and 979 who are unaware of their status.

Conclusions

Overall, 9% of our cohort was HIV‐HCV co‐infected. The prevalence was highest among intravenous drug users (82%), who accounted for most of our HCV cases, and lowest among heterosexual men and women from sub‐Saharan Africa and the Caribbean [< 2%]. Our estimate that a significant number of co‐infected persons may be unaware of their HIV and HCV status, highlights an urgent need to increase the uptake of HCV and HIV testing, particularly among injecting drug users, to reduce the risk of onward transmission.
2002 LAWRENCE R. KLEIN LECTURE LIQUIDITY AND ASSET PRICES*
Authors: Kiyotaki Nobuhiro , Moore John
Published: May 2005

We broadly define liquid assets, or monetary assets, as any asset that can be readily sold in the market and can be held by a number of people in succession before maturity. We ask in what environment is the circulation of liquid assets essential for the smooth running of the economy. By developing a canonical model of a monetary economy (i.e., where the circulation of liquid assets is essential), we are able to examine the interaction between liquidity, asset prices, and aggregate economic activity.
MONEY AS A MECHANISM IN A BEWLEY ECONOMY*
Authors: Green Edward J. , Zhou Ruilin
Published: May 2005

We investigate the efficiency property of a monetary economy with spot trade. We prove a conjecture that is essentially due to Bewley (Models of Monetary Economics(1980);Econometrica51 (1983), 1485–504). The gist is that monetary spot trading is nearly efficient ex ante in an environment where very patient agents can accumulate large enough money stocks to be completely self‐insured. We also study examples where a nonmonetary mechanism is preferred ex ante to any monetary mechanism in a stationary environment, and where an inflationary monetary mechanism is preferred ex ante to a laissez‐faire or deflationary monetary mechanism in an environment with impatient agents.
HETEROGENEITY, REDISTRIBUTION, AND THE FRIEDMAN RULE*
Authors: Bhattacharya Joydeep , Haslag Joseph H. , Martin Antoine
Published: May 2005

We study monetary models with nondegenerate stationary distributions of money holdings. We find that the Friedman rule does not typically maximize ex post social welfare. An increase in the rate of growth of the money supply has two effects: the standard distortionary, or rate‐of‐return, effect makes money a less desirable asset for all moneyholders. A second, redistributive effect, creates a transfer from one type of agent to the other. An increase in the rate of growth of money away from the Friedman rule can produce a rate‐of‐return effect that dominates the standard effect.
THE DISTRIBUTION OF MONEY BALANCES AND THE NONNEUTRALITY OF MONEY*
Authors: Berentsen Aleksander , Camera Gabriele , Waller Christopher
Published: May 2005

Recent monetary models with explicit microfoundations are made tractable by assuming that agents have access to centralized markets after one round of decentralized trade. Given quasi‐linear preferences, this makes the distribution of money degenerate—which keeps the models simple but precludes the discussion of distributional effects of monetary policy. We generalize these models by assuming two rounds of trade before agents can readjust their money holdings to study a range of new distributional effects analytically. We show that unexpected, symmetric lump‐sum money injections may increase short‐run output and welfare, whereas asymmetric injections may increase long‐run output and welfare.
COMMENT ON “THE DISTRIBUTION OF MONEY BALANCES AND THE NONNEUTRALITY OF MONEY,” BY ALEKSANDER BERENTSEN, GABRIELE CAMERA, AND CHRISTOPHER WALLER*
Authors: Williamson Stephen D.
Published: May 2005

An example is constructed to illustrate some points about the Berentsen‐Camera‐Waller article, followed by some comments.
PRICE DISPERSION, INFLATION, AND WELFARE*
Authors: Head Allen , Kumar Alok
Published: May 2005

We examine the implications of inflation for both price dispersion and welfare in a monetary search economy. In our economy, if the degree of buyers' incomplete information about prices is fixed, both price dispersion and real prices are increasing in inflation. As the inflation rate approaches the Friedman rule, both price dispersion and welfare losses vanish. If households choose the number of prices to observe, then the optimal inflation rate may exceed the Friedman rule as inflation induces search and, up to a point, raises welfare by eroding market power.