bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of haemodialysis on QTc dispersion in children
Authors: OZDEMIR DURGUL , MESE TIMUR , AGIN HASAN , CALKAVUR SEBNEM , BAK MUSTAFA 
Published: May 2005

SUMMARY: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

SUMMARY: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

SUMMARY: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

SUMMARY: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

SUMMARY: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

SUMMARY: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.
Non‐propagating crack behaviour at giga‐cycle fretting fatigue limit
Authors: KONDO Y. , SAKAE C. , KUBOTA M. , YANAGIHARA K. 
Published: May 2005

ABSTRACTFretting 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

ABSTRACTFailure 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

ABSTRACTThe 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

ObjectivesTo 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.MethodsHeavily 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.ResultsSixty‐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.ConclusionsAbout 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

ObjectivesTo 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).MethodsAnalysis 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.ResultsAmong 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.ConclusionsWhile 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

ObjectivesThe 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.DesignAn 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.ResultsThirty 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.ConclusionsIn 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

ObjectivesThere 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.MethodsA 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.ResultsOf 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.ConclusionsOverall, 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.
Catamenial Epilepsy: The Elusive Condition
Authors: French Jacqueline A. 
Published: May 2005

Frequency of Catamenial Seizure Exacerbation in Women with Localization-related Epilepsy Herzog AG, Harden CL, Liporace J, Pennell P, Schomer DL, Sperling M, Fowler K, Nikolov B, Shuman S, Newman M Ann Neurol 2004;56:431–434 This investigation assessed the frequency of catamenial epilepsy in 87 women who charted seizures and menses during three cycles. Catamenial epilepsy designation was made if two of three cycles showed at least one of three previously defined catamenial patterns. Among ovulatory cycles, average daily seizure frequency was significantly greater during the perimenstrual and preovulatory phases. Among anovulatory cycles, average daily seizure frequency was substantially less during the midfollicular phase than during the remainder of the cycle. Overall, 39.1% of the women had catamenial epilepsy.