bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proarrhythmia as a Class Effect of Quinolones: Increased Dispersion of Repolarization and Triangulation of Action Potential Predict Torsades de Pointes
Authors: MILBERG PETER , HILKER EKKEHARD , RAMTIN SHAHRAM , CAKIR YILMAZ , STYPMANN JÖRG , ENGELEN MARKUS A. , MÖNNIG GEROLD , OSADA NANI , BREITHARDT GÜNTER , HAVERKAMP WILHELM , ECKARDT LARS 
Published: March 2007

Background:Numerous noncardiovascular drugs prolong repolarization and thereby increase the risk for patients to develop life‐threatening tachyarrhythmias of the torsade de pointes (TdP) type. The development of TdP is an individual, patient‐specific response to a repolarization‐prolonging drug, depending on the repolarization reserve. The aim of the present study was to analyze the underlying mechanisms that discriminate hearts that will develop TdP from hearts that will not develop TdP. We therefore investigated the group of quinolone antibiotics that reduce repolarization reserve via IKrblockade in an intact heart model of proarrhythmia.Methods and Results:In 47 Langendorff‐perfused, AV‐blocked rabbit hearts, ciprofloxacin (n = 10), ofloxacin (n = 14), levofloxacin (n = 10), and moxifloxacin (n = 13) in concentrations from 100 μM to 1,000 μM were infused. Eight monophasic action potentials (MAPs) and an ECG were recorded simultaneously. After incremental pacing at cycle lengths from 900 ms to 300 ms to compare the action potential duration, potassium concentration was lowered to provoke TdP. All antibiotics led to a significant increase in QT interval and MAP duration, and exhibited reverse‐use dependence. Eight simultaneously recorded MAPs demonstrated an increase in dispersion of repolarization in the presence of all antibiotics. MAP triangulation (ratio: MAP90/50) and fluctuation of consecutive action potentials were increased for all tested drugs at high concentrations. In the presence of low potassium concentration, all quinolones led to TdP: ciprofloxacin, 4 out of 10 (40%); ofloxacin, 3 out of 14 (21%); moxifloxacin, 9 out of 13 (69%); and levofloxacin, 2 out of 10 (20%). Hearts that developed TdP demonstrated a significant greater influence on dispersion of repolarization and on triangulation as compared with hearts without TdP.Conclusion:Quinolone antibiotics may be proarrhythmic due to a significant effect on myocardial repolarization. The individual response of a heart to develop TdP in this experimental model is characterized by a greater effect on dispersion of repolarization and on triangulation of action potential as compared with hearts that do not develop TdP.
Initial Experience with a Novel Remote‐Guided Magnetic Catheter Navigation System for Left Ventricular Scar Mapping and Ablation in a Porcine Model of Healed Myocardial Infarction
Authors: RAY INDRANILL BASU , DUKKIPATI SRINIVAS , HOUGHTALING CHRISTOPHER , MCPHERSON CHRISTINA D. , KASTELEIN NATHAN , RUSKIN JEREMY N. , REDDY VIVEK Y. 
Published: March 2007

Objective: This study examined the feasibility of using a remote magnetic catheter navigation system (MNS) in concert with an EAM system to perform detailed left ventricular scar mapping and ablation in a porcine model of healed myocardial infarction. Background: Substrate‐based catheter ablation of ventricular tachycardia (VT) involves detailed electroanatomical mapping (EAM) of the ventricles. While a safe and effective procedure, VT ablation is nonetheless uncommonly performed, due in part to the technical challenges related to ventricular mapping. Methods: Using a prototype EAM system (CARTO‐RMT), seven chronically infarcted swine were mapped using either: (i) a standard manually manipulated catheter or (ii) a magnetic remotely manipulated (Niobe) catheter. A total of 191 ± 54 and 221 ± 64 points were acquired to map the chamber either manually or remotely, respectively. Results: Procedure times were longer remotely (94 ± 22 vs. 59 ± 19 minute, P = 0.004; and 27 ± 8 vs. 18 ± 3 sec/point, P = 0.04), but this became less apparent with increased operator experience. However, the fluoroscopy time was significantly shorter with remote mapping (56 ± 56 vs. 244 ± 67 sec/map, P = 0.03). The calculated scar size was comparable between the two methods (16.3 ± 4.9 vs. 16.4 ± 4.8 cm2, P = 0.37). Pathologic examination confirmed that the MNS was able to precisely deliver radiofrequency lesions to the scar borders. Using the MNS, the error to reach an evenly distributed set of endocardial targets was 6.6 ± 3.6 mm and 4.6 ± 2.0 mm, using transseptal and retrograde approaches, respectively. Conclusions: Ventricular mapping using this remote navigation paradigm is technically possible and requires minimal fluoroscopy exposure, potentially facilitating ventricular substrate mapping and ablation.
Recurrence of a Phe31Ser mutation in the Gla domain of blood coagulation factor X, in unrelated Algerian families: a founder effect?
Authors: Akhavan Sepideh , Chafa Ouerdia , Nsoure Obame Fatou , Torchet Marie‐Françoise , Reghis Abderrezak , Fischer Anne‐Marie , Tapon‐Bretaudière Jacqueline 
Published: March 2007

AbstractThe presence of gene lesions in blood coagulation factor X (FX) was investigated in eight FX‐deficient patients with severe bleeding symptoms, originating from five unrelated Algerian families (FX coagulant activity <1%, FX antigen ranging from 2% to 16%). A missense mutation (p.Phe31Ser) in the Gla domain was found in homozygous form for all patients but one, who is a compound heterozygote for the Phe31Ser mutation and for a non‐sense mutation, Tyr130Term in EGF‐2 domain. The haplotypes of FX alleles were determined by the following allelic variants located in the promoter: g.1323_1330delTTGTGA (A1/A2), g.1449T>C, g.1451C>A, upstream to exon 3: g.17257C>T and downstream to exon 3: g.17396A>C. The A1‐C‐A‐T‐C haplotype was found on each allele bearing the Phe31Ser mutation in the eight FX deficient patients contrasting with its low frequency (8%) in a control Algerian population (in which the Phe31Ser substitution was absent). The patients came from the same geographical area of Algeria (5/8 are certainly from Kabyle origin) and the haplotype analysis suggests a founder effect. Transient expression study reveals that, for the mutant FX‐Phe31Ser, FX antigen level was 60% in conditioned media and 140% in cell lysates compared with the wild type FX. The partial retention and intracellular accumulation of the mutant FX might be due to impaired folding and/or conformational changes, and the discrepancies observed between the FX antigen level in COS‐7 cell supernatant (60%) and in the patients plasma (2–16%) to an in vivo increased clearance of the secreted unstable FX mutant.
Correction of anemia in a transfusion‐dependent patient with primary myelofibrosis receiving iron chelation therapy with deferasirox (Exjade®, ICL670)
Authors: Di Tucci Anna Angela , Murru Roberta , Alberti Daniele , Rabault Bertrand , Deplano Simona , Angelucci Emanuele 
Published: March 2007

AbstractTransfusional iron overload in patients with chronic anemias can result in multiple organ failure. Experience in the management of iron overload in patients with myelodysplastic syndromes is limited, as many do not receive chelation therapy due to short‐life expectancy and the difficulties associated with the administration of the current reference standard chelator, deferoxamine. There have, however, been some reports of reduced transfusion requirement associated with chelation therapy in patients with myelodysplastic syndromes and myelofibrosis. Here, we discuss a patient with primary myelofibrosis and related transfusion‐dependent anemia who received chelation therapy with the once‐daily oral iron chelator, deferasirox. In addition to the reduced iron levels, the patient demonstrated an unexpected reduction in blood transfusion requirement, ultimately resulting in long‐lasting transfusion‐free survival.
Oral health risks associated with HLA‐types of patients undergoing hematopoietic stem cell transplantation
Authors: Dobr Tereza , Passweg Jakob , Weber Catherine , Tichelli André , Heim Dominik , Meyer Jürg , Gratwohl Alois , Waltimo Tuomas 
Published: March 2007

AbstractAim:  Dental caries, gingivitis and periodontitis are frequent long‐term complications after hematopoietic stem cell transplantation (HSCT). Not all patients are affected equally. As HLA‐genotypes are associated with many functions of the immune system we made use of our long‐standing oral health program in HSCT recipients to compare oral health data with recipient HLA‐antigens.Patients and methods:  This study includes 267 patients evaluated prior to a planned HSCT at our institution between March 1987 and March 2002. Standardized oral examinations were undertaken at fixed time points: pre‐HSCT and at 6 and 12 months post‐HSCT. Evaluation included loss of radiologic attachment level, decayed, missing, filled teeth (DMFT) index, and salivary flow rate. For 241 patients (120 males, 121 females) baseline values of these parameters were compared with recipient HLA‐A, ‐B, ‐C and ‐DR‐antigens.Results:  Significant correlations were found between increased DMFT and HLA‐A32 (P = 0.05), ‐B5 (0.04), and ‐DR2 (0.05) as well as decreased DMFT with HLA‐B35 (0.02) and ‐C4 (0.04). Significant associations were also found between certain HLA‐antigens and loss of radiologic periodontal attachment level [HLA‐A1 (<0.01), ‐C7 (0.04), and ‐B60 (0.05)], and saliva flow rate [HLA‐A30 (0.02)].Conclusions:  These data suggest that there may be associations between pretransplant caries, other oral parameters and HLA in patients at HSCT. Confirmatory studies concerning the associations of certain HLA‐antigens with caries and periodontal diseases will be needed.
Long‐term outcome of intensive chemotherapy for adults with de novo acute myeloid leukaemia (AML): the nationwide AML‐92 study by the Finnish Leukaemia Group
Authors: Koistinen Pirjo , Räty Riikka , Itälä Maija , Jantunen Esa , Koivunen Elli , Nousiainen Tapio , Pelliniemi Tarja‐Terttu , Remes Kari , Ruutu Tapani , Savolainen Eeva‐Riitta , Siitonen Timo , Silvennoinen Raija , Volin Liisa , Elonen Erkki ,   for the Finnish Leukaemia Group
Published: March 2007

AbstractObjective:  To investigate the long‐term outcome of idarubicin‐ and cytarabine‐based intensive chemotherapy in adult acute myeloid leukaemia (AML).Patients and methods:  A total of 327 consecutive patients with de novo AML (promyelocytic leukaemia excluded) aged 16–65 yr were recruited into the study between September 1992 and December 2001. The latest follow‐up data were collected in October 2006. After remission achievement with the first (conventional cytarabine) or second (high‐dose cytarabine) chemotherapy cycle, three intensive consolidation courses each containing high‐ or intermediate‐dose cytarabine were given.Results:  A total of 268 patients (82%) achieved complete remission (CR). CR rate was 82% and 84% for patients <60 and ≥60 yr of age, respectively. CR rates in patients with favourable (93%) and intermediate/normal karyotypes (87%) were significantly (P < 0.01) higher than CR rate in patients with adverse karyotype (61%). Median relapse‐free survival (RFS) for the patients not transplanted in the first CR (n = 195) was 1.7 yr (95% CI: 0.81–2.60). At 4 yr, a plateau of 70% in RFS was reached for patients with favourable karyotypes. The 5‐yr survival was 71%, 47% and 37% for the non‐transplanted patients (n = 202) with favourable, intermediate/normal and intermediate/abnormal karyotypes, respectively, while only 8% of the patients having adverse karyotype were alive at 5 yr (P < 0.01). Of the patients with favourable, intermediate/normal or intermediate/abnormal karyotypes, respectively, 58%, 41% and 31% were expected to be alive at 10 yr.Conclusions:  Idarubicin‐ and cytarabine‐based intensive chemotherapy regimen is very effective in de novo AML for adult patients up to 65 yr of age. New treatment strategies are needed, however, to improve the outcome of the patients with intermediate and adverse karyotypes.
Effect of hypoxia and interleukin‐1β on expression of tenascin‐C in temporomandibular joint
Authors: Tojyo I , Yamaguchi A , Nitta T , Yoshida H , Fujita S , Yoshida T 
Published: March 2007

Objective:  The expression of tenascin‐C in the synovial membrane of the internal derangement (ID) of the temporomandibular joint (TMJ) has been reported. Hypoxia of the synovial membrane in TMJ is considered to be a cause for the pathophysiology of ID. In this study, we clarify the contribution of hypoxia and interleukin‐1β in the expression of tenascin‐C in ID of TMJ.Materials and methods:  Synovial fibroblasts and disk cells obtained from ID of TMJs were cultured and treated with interleukin‐1β under normoxia and hypoxia. A Western blot analysis and reverse transcription‐polymerase chain reaction analysis were used to identify tenascin‐C in cultured synovial fibroblasts and disk cells. In addition, the immunohistochemical staining of tenascin‐C was carried out for the specimens of ID of TMJs and normal.Results:  The combination of hypoxia and interleukin‐1β caused a significant increase in tenascin‐C protein and mRNA of synovial fibroblasts. In contrast, the combination caused no increase in tenascin‐C in disk cells. However, the immunohistochemical staining demonstrated tenascin‐C to be significantly detected in both the synovial tissue and disks in ID of TMJ.Conclusions:  These results indicate that hypoxic conditions with inflammation modulate the tenascin‐C expression in synovial fibroblasts, but not in disk cells.
Intensive Care in Critical Access Hospitals
Authors: Freeman Victoria A. , Walsh Joan , Rudolf Matthew , Slifkin Rebecca T. , Skinner Asheley Cockrell 
Published: March 2007

ABSTRACT:
Context:
Although critical access hospitals (CAHs) have limitations on number of acute care beds and average length of stay, some of them provide intensive care unit (ICU) services. Purpose:To describe the facilities, equipment, and staffing used by CAHs for intensive care, the types of patients receiving ICU care, and the perceived impact of closing the ICU on CAH staff and the local community. Methods:A semistructured interview of directors of nursing at CAHs that provide intensive care services. Results:Two thirds of CAHs that provide intensive care do so in a distinct unit. Most have continuous or computerized electrocardiography and ventilators. Other ICU equipment common in larger hospitals was reported less frequently. Nurse:patient ratio ranged from 1:1 to 1:3, and some or all nursing staff have advanced cardiac life support certification. Most CAHs admit patients to the ICU daily or weekly, primarily treating cardiac, respiratory, gastrointestinal, endocrine, and drug‐ or alcohol‐related conditions. ICUs are also used for postsurgical recovery. Respondents felt that closure of the ICU would be burdensome to patients and families, result in lost revenue, negatively impact staff, and affect the community’s perception of the hospital. Conclusions:Intensive care services provided by CAHs fall along a continuum, ranging from care in a unit that resembles a scaled‐down version of ICUs in larger hospitals to care in closely monitored medical‐surgical beds. Nurse to patient ratio, not technology, is arguably the defining characteristic of intensive care in CAHs. Respondents believe these services to be important to the well‐being of the hospital and of the community.
Rural/Urban Differences in Barriers to and Burden of Care for Children With Special Health Care Needs
Authors: Skinner Asheley Cockrell , Slifkin Rebecca T. 
Published: March 2007

ABSTRACT:
Purpose: To examine the barriers and difficulties experienced by rural families of children with special health care needs (CSHCN) in caring for their children. Methods: The National Survey of Children with Special Health Care Needs was used to examine rural‐urban differences in types of providers used, reasons CSHCN had unmet health care needs, insurance and financial difficulties encountered, and the family burden of providing the child’s medical care. We present both unadjusted and adjusted results to allow consideration of the causes of rural‐urban differences. Findings: Rural CSHCN are less likely to be seen by a pediatrician than urban children. They are more likely to have unmet health care needs due to transportation difficulties or because care was not available in the area; there were minimal other differences in barriers to care. Families of rural CSHCN are more likely to report financial difficulties associated with their children’s medical needs and more likely to provide care at home for their children. Conclusions: Examining results from both unadjusted and adjusted odds ratios shows that the burden of care for families of rural CSHCN stems both from socioeconomic differences and health system differences. Policies aimed at achieving equity for rural children will require focusing on both individual factors and the health care infrastructure, including increasing insurance coverage to lessen financial difficulties and addressing the availability of providers in rural areas.
Information Seeking and Intentions to Have Genetic Testing for Hereditary Cancers in Rural and Appalachian Kentuckians
Authors: Kelly Kimberly M. , Andrews James E , Case Donald O. , Allard Suzanne L. , Johnson J. David 
Published: March 2007

ABSTRACT:
Context: Research is limited regarding the potential of genetic testing for cancer risk in rural Appalachia. Purpose: This study examined perceptions of genetic testing in a population sample of Kentuckians, with a focus on Appalachian and rural differences. The goals were to examine cultural and psychosocial factors that may predict intentions to test for hereditary cancer, need for help with information seeking for decision making about genetic testing for hereditary cancer, and amount of help needed with information seeking for decision making about genetic testing for hereditary cancer in this population. Methods: Analysis of data from a general social survey of adults using random‐digit dialing in Kentucky (N = 882). Findings: An ordinal regression found that younger age, having a family history of cancer, and greater worry predicted greater intentions to seek genetic testing. A logistic regression found that having more education, excellent subjective knowledge of genetics, and less worry about cancer predicted less need for help in seeking information about testing. An ordinal regression found that less subjective knowledge of genetics and greater worry predicted greater amount of help needed. Conclusions: Additional counseling to explain limitations of genetic testing may be needed. Further, those with less knowledge about genetics and more worry about hereditary cancer may have greater need for help with information seeking for decision making, a need that may be further exacerbated by the lack of medical professionals, particularly genetic counselors, who may provide information about genetic testing in rural, Appalachian Kentucky.
Prioritizing Threats to Patient Safety in Rural Primary Care
Authors: Singh Ranjit , Singh Ashok , Servoss Timothy J. , Singh Gurdev 
Published: March 2007

ABSTRACT:
Context: Rural primary care is a complex environment in which multiple patient safety challenges can arise. To make progress in improving safety with limited resources, each practice needs to identify those safety problems that pose the greatest threat to patients and focus efforts on these. Purpose: To describe and field‐test a novel approach to prioritizing safety problems in rural primary care based on the method of Failure Modes and Effects Analysis. Methods: A survey instrument designed to assess perceptions of medical error frequency, severity, and cause was administered anonymously to staff of 2 rural primary care practices in New York State. Responses were converted to quantitative hazard scores, which were used to make priority rankings of safety problems. Concordance analysis was conducted. Results: Response rate was 94% at each site. Analysis yielded a list of priorities for each site. Comparison between staff groups (provider vs nursing vs administration), based on the top 10 priorities perceived by staff, showed 53% concordance at one site and 30% at the other. Concordance between sites was lower, at 20%. Conclusions: Initial field‐testing of a Failure Modes and Effects Analysis approach in rural primary care suggests that it is feasible and can be used to estimate, based on staff perceptions, the greatest threats to patient safety in an individual practice so that limited resources can be focused appropriately. Higher concordance between staff within a practice than between practices lends preliminary support to the validity of the approach.
Salt in the Food and Water as a Supportive Therapy for Ichthyophthirius multifiliis Infestation on Silver Catfish, Rhamdia quelen, Fingerlings
Authors: Garcia Lucianode O. , Becker Alexssandro G. , Copatti Carlos E. , Baldisserotto Bernardo , Neto João Radünz 
Published: March 2007

Abstract This study verified the efficacy of common salt (NaCl) in the food and water as a supportive therapy for Ichthyophthirius multifiliis and growth of silver catfish, Rhamdia quelen, fingerlings. After appearance of the first white spots following experimental exposure, indicating infestation by this parasite, fish were transferred to eighteen 40‐L polypropylene tanks and kept for 30 d. Experimental diets were prepared with five different levels of salt supplementation: 0.0, 1.2, 2.5, 5.0, and 6.0% for 30 d. In addition, another group of fish were fed a diet without salt supplementation but exposed to 4 g of salt/L of water. Fingerlings were collected at different times for analyses of whole‐body Na+, K+, and Cl−. Dietary salt supplementation provoked a transitory increase in whole‐body Na+, K+, and Cl− in infested catfish fingerlings, but the best stabilization of these ion levels was observed in specimens exposed to salt in the water. Silver catfish fed a diet containing 1.2% salt showed higher weight and biomass after 30 d compared to those fed with 6% salt. The use of 4 g of salt/L of water improved survival of infested silver catfish, but dietary salt supplementation was ineffective as a therapy for ichthyophthiriasis.
Effect of Sublethal Hypoxia on the Immune Response and Susceptibility of Channel Catfish, Ictalurus punctatus, to Enteric Septicemia
Authors: Welker Thomas L. , Mcnulty Shawn T. , Klesius Phillip H. 
Published: March 2007

Abstract The effect of sublethal hypoxia exposure on stress and immune responses and susceptibility to Edwardsiella ictaluri infection in juvenile channel catfish, Ictalurus punctatus, was investigated. Fish were monitored for temporal changes in glucose and cortisol concentrations before, during, and after 2 h exposure to sublethal hypoxia (<2 mg/L dissolved oxygen [DO]) and when maintained under normoxic conditions (6.0 ± 0.3 mg/L DO). Both blood glucose and plasma cortisol increased significantly in response to hypoxic conditions. Fish exposed to hypoxic or normoxic conditions were challenged with a high dose (1.3 × 107 colony‐forming units [CFU]/mL) or a low dose (1.3 × 105 CFU/mL) of E. ictaluri or sterile culture broth by 30‐min immersion bath. Approximately 1% of fish in both the normoxic and the hypoxic groups died when challenged with the low dose of E. ictaluri. However, when challenged with the high dose of E. ictaluri, catfish exposed to hypoxic conditions had significantly higher cumulative mortality (36 ± 12.1%) than those maintained under normoxic conditions (12 ± 1.1%). Total hemolytic complement and bactericidal activities and antibody response were lower in hypoxia‐exposed channel catfish, indicating that increased susceptibility of channel catfish to E. ictaluri may be the result of the immunosuppressive effects of the stress response to hypoxia.