bluuebunny/crossref_metadata_2025 huggingface dataset:
RAD51C deficiency in mice results in early prophase I arrest in males and sister chromatid separation at metaphase II in females
Authors: Kuznetsov Sergey , Pellegrini Manuela , Shuda Kristy , Fernandez-Capetillo Oscar , Liu Yilun , Martin Betty K. , Burkett Sandra , Southon Eileen , Pati Debananda , Tessarollo Lino , West Stephen C. , Donovan Peter J. , Nussenzweig Andre , Sharan Shyam K.
Published: February 2007

RAD51C is a member of the RecA/RAD51 protein family, which is known to play an important role in DNA repair by homologous recombination. In mice, it is essential for viability. Therefore, we have generated a hypomorphic allele of Rad51c in addition to a null allele. A subset of mice expressing the hypomorphic allele is infertile. This infertility is caused by sexually dimorphic defects in meiotic recombination, revealing its two distinct functions. Spermatocytes undergo a developmental arrest during the early stages of meiotic prophase I, providing evidence for the role of RAD51C in early stages of RAD51-mediated recombination. In contrast, oocytes can progress normally to metaphase I after superovulation but display precocious separation of sister chromatids, aneuploidy, and broken chromosomes at metaphase II. These defects suggest a possible late role of RAD51C in meiotic recombination. Based on the marked reduction in Holliday junction (HJ) resolution activity in Rad51c-null mouse embryonic fibroblasts, we propose that this late function may be associated with HJ resolution.
Replication history of B lymphocytes reveals homeostatic proliferation and extensive antigen-induced B cell expansion
Authors: van Zelm Menno C. , Szczepański Tomasz , van der Burg Mirjam , van Dongen Jacques J.M.
Published: February 2007

The contribution of proliferation to B lymphocyte homeostasis and antigen responses is largely unknown. We quantified the replication history of mouse and human B lymphocyte subsets by calculating the ratio between genomic coding joints and signal joints on kappa-deleting recombination excision circles (KREC) of the IGK-deleting rearrangement. This approach was validated with in vitro proliferation studies. We demonstrate that naive mature B lymphocytes, but not transitional B lymphocytes, undergo in vivo homeostatic proliferation in the absence of somatic mutations in the periphery. T cell–dependent B cell proliferation was substantially higher and showed higher frequencies of somatic hypermutation than T cell–independent responses, fitting with the robustness and high affinity of T cell–dependent antibody responses. More extensive proliferation and somatic hypermutation in antigen-experienced B lymphocytes from human adults compared to children indicated consecutive responses upon additional antigen exposures. Our combined observations unravel the contribution of proliferation to both B lymphocyte homeostasis and antigen-induced B cell expansion. We propose an important role for both processes in humoral immunity. These new insights will support the understanding of peripheral B cell regeneration after hematopoietic stem cell transplantation or B cell–directed antibody therapy, and the identification of defects in homeostatic or antigen-induced B cell proliferation in patients with common variable immunodeficiency or another antibody deficiency.
Interleukin-2 enhances CD4+ T cell memory by promoting the generation of IL-7Rα–expressing cells
Authors: Dooms Hans , Wolslegel Kristen , Lin Patricia , Abbas Abul K.
Published: February 2007

The common γ chain cytokines interleukin (IL)-2 and IL-7 are important regulators of T cell homeostasis. Although IL-2 is implicated in the acute phase of the T cell response, IL-7 is important for memory T cell survival. We asked whether regulated responsiveness to these growth factors is determined by temporal expression of the cytokine-specific IL-2 receptor (R) α and IL-7Rα chains. We demonstrate that IL-2Rα is expressed early after priming in T cell receptor–transgenic CD4+ T cells, whereas IL-7Rα expression is lost. In the later stage of the response, IL-7Rα is reexpressed while IL-2Rα expression is silenced. This reciprocal pattern of IL-2Rα/IL-7Rα expression is disturbed when CD4+ T cells are primed in the absence of IL-2 signals. Primed IL-2−/− or CD25−/− (IL-2Rα−/−) CD4+ T cells, despite showing normal induction of activation markers and cell division, fail to reexpress IL-7Rα late in the response. Because the generation of CD4+ memory T cells is dependent on IL-7–IL-7Rα interactions, primed IL-2−/− or CD25−/− CD4+ T cells develop poorly into long-lived memory cells. Retrovirus-mediated expression of IL-7Rα in IL-2−/− T cells restores their capacity for long-term survival. These results identify IL-2 as a factor regulating IL-7Rα expression and, consequently, memory T cell homeostasis in vivo.
Closed timelike geodesics in compact spacetimes
Authors: Guediri Mohammed
Published: February 2007

Let

M
M

be a compact spacetime which admits a regular globally hyperbolic covering, and

C

{\mathcal C}

a nontrivial free timelike homotopy class of closed timelike curves in

M
.

M.

We prove that

C

{\mathcal C}

contains a longest curve (which must be a closed timelike geodesic) if and only if the timelike injectivity radius of

C

{\mathcal C}

is finite; i.e.,

C

{\mathcal C}

has a bounded length. As a consequence among others, we deduce that for a compact static spacetime there exists a closed timelike geodesic within every nontrivial free timelike homotopy class having a finite timelike injectivity radius.
QIP, a putative exonuclease, interacts with the Neurospora Argonaute protein and facilitates conversion of duplex siRNA into single strands
Authors: Maiti Mekhala , Lee Heng-Chi , Liu Yi
Published: February 2007

Single-stranded small interfering RNA (siRNA) guides the cleavage of homologous mRNA by Argonaute proteins, the catalytic core of the RNA-induced silencing complex (RISC), in the conserved RNA interference (RNAi) pathway. The separation of the siRNA duplex into single strands is essential for the activation of RISC. Previous biochemical studies have suggested that Argonaute proteins cleave and remove the passenger strand of siRNA duplex from RISC, but the in vivo importance of this process and the mechanism for the removal of the nicked passenger strand are not known. Here, we show that in the filamentous fungus Neurospora, the Argonaute homolog QDE-2 and its slicer function are required for the generation of single-stranded siRNA and gene silencing in vivo. Biochemical purification of QDE-2 led to the identification of QIP, a QDE-2-interacting protein, with an exonuclease domain. The disruption of qip in Neurospora impaired gene silencing and siRNA accumulated, mostly in nicked duplex form. Furthermore, our results suggest that QIP acts as an exonuclease that cleaves and removes the nicked passenger strand from siRNA duplex in a QDE-2-dependent manner. Together, these results suggest that both the cleavage and removal of the passenger strand from the siRNA duplex are important steps in RNAi pathways.
Using a patient‐controlled analgesia multimedia intervention for improving analgesia quality
Authors: Yeh Mei‐Ling , Yang Hui‐Ju , Chen Hsing‐Hsia , Tsou Mei‐Yung
Published: February 2007

Aim.  To evaluate the effects of analgesia quality provided by a patient‐controlled analgesia multimedia intervention on the pain management of postsurgical patients in Taiwan.

Background.  The concept of patient‐controlled analgesia has become the mainstream pain treatment method because of its characteristic of instant self‐administering medication. It is an important mission of nursing professionals to communicate effective and correct knowledge of patient‐controlled analgesia on how to relieve pain and improve quality of care.

Design.  A quasi‐experiment research design was used for this study. Sixty subjects recruited from a medical teaching centre of Taiwan were assigned into either the experimental (n = 30) or control group (n = 30). The experimental group received the patient‐controlled analgesia multimedia intervention. The control group only received one‐on‐one patient education of routine nursing guide and pain management with pamphlet. The pain cognition and American Pain Society patient outcome questionnaires were used as measures of effects for the interventions.

Results.  The results showed the experimental group, compared with the control group, had significant improvement in pain cognition and analgesia quality. There is significant correlation between pain cognition and analgesia quality.

Conclusions.  After intervening, the patients approved of the patient‐controlled analgesia multimedia intervention and affirmed the value of early acquisition of such information to their postsurgical treatments and recoveries. The higher the pain cognition patients obtained, the better the analgesia quality patients had.

Relevance to clinical practice.  Applying the patient‐controlled analgesia multimedia intervention for surgical patients to improve pain cognition, the utility of patient‐controlled analgesia, pain relief and patient satisfaction is recommended.
Influence of economic and demographic factors on quality of life in renal transplant recipients
Authors: Chisholm Marie A. , Spivey Christina A. , Nus Audrey Van
Published: February 2007

Abstract:  Background:  The purpose of this study was to determine the influence of annual income, Medicare status, and demographic variables on the health‐related quality of life (HQoL) of renal transplant recipients.

Methods:  A cross‐sectional survey was mailed to 146 Georgia renal transplant recipients who had functional grafts. Data were collected using the SF‐12 Health Survey (version 2), a demographics survey, and 2003 tax documents. One‐way ANOVAs and Pearson's R correlations were used to examine relationships between annual income, Medicare status, demographic variables and SF‐12 scores. Significant variables were included in stepwise multiple regression analyses.

Results:  Data from 130 participants (89% response rate) were collected. Recipients with no Medicare coverage had significantly higher scores on the Physical Functioning and Role Physical SF‐12 scales (p = 0.005) compared to recipients with Medicare. Annual income was positively correlated with General Health (p < 0.05). Age and race were significant predictors of Vitality (p = 0.004) and Physical Component Summary (p < 0.001) scores. Age, race, and Medicare status were significant predictors of Physical Functioning and Role Physical scores (p < 0.001). Age, annual income, race, and years post‐transplant were significant predictors of General Health score (p < 0.001). Age was the sole predictor of Bodily Pain score (p = 0.002), and marital status was the sole predictor of Social Functioning score (p = 0.005).

Conclusions:  Interventions designed to offset financial barriers may be needed to bolster renal transplant recipients’ HQoL.
Acute rejection in non‐compliant renal allograft recipients: a distinct morphology
Authors: Lerut Evelyne , Kuypers Dirk R , Verbeken Erik , Cleutjens Jack , Vlaminck Hans , Vanrenterghem Yves , Damme Boudewijn Van
Published: February 2007

Abstract:  Non‐compliance for immunosuppressive medication is frequent in renal transplant recipients, and associated with late acute rejection and graft loss. Although numerous studies were published on risk factors and outcome, no data are available on the histopathology of the ‘non‐compliant’ allograft. As non‐compliant patients swing between subtherapeutic and toxic doses of immunosuppression, trough levels show large variation. We questioned whether the histology of acute rejection in non‐compliers (i) differs from the ‘classical’ acute rejection; (ii) shows more concomitant calcineurin‐inhibitor toxicity; (iii) is associated with C4d and plasma cell (PC)‐rich infiltrates. Based on validated interview methods/self reporting, 145 adult renal allograft recipients, transplanted for greater than one yr, on cyclosporine A and corticosteroids, were categorized as either compliant or non‐compliant. Non‐compliance was defined in 32 patients (22.1%). All late (greater than one yr) allograft biopsies were reviewed (Banff) and immuno‐stained for C4d. Computerized morphometry was performed on late biopsies with features of acute cellular rejection. Sixty‐two patients had ≥1 late biopsy [41 (36.2%) compliant/21 (65.6%) non‐compliant; p = 0.0043], comprising a pool of 90 biopsies (61 compliant/29 non‐compliant; p = 0.0303). ‘Non‐compliant’ biopsies had higher scores of C4d (p = 0.0092), acute tubular damage (p = 0.0058), and peritubular capillaritis (p = 0.0070). ‘Non‐compliant’ biopsies with acute cellular rejection showed less interstitial edema (p = 0.0165), more interstitial infiltrate (p = 0.0100), more interstitial fibrosis (p = 0.0277), and more tubular atrophy (p = 0.0197). PC‐rich infiltrates correlated with C4d (p = 0.0080). Detection of non‐compliance is mandatory as it represents an important cause of graft loss. This study describes histologic features of renal allograft biopsies in non‐compliant patients that could help identifying this patient profile.
Three‐yr follow‐up of a type 1 diabetes mellitus patient with an islet xenotransplant
Authors: Valdés‐González R.A. , White D.J.G. , Dorantes L.M. , Terán L. , Garibay‐Nieto G.N. , Bracho‐Blanchet E. , Dávila‐Pérez R. , Evia‐Viscarra L. , Ormsby C.E. , Ayala‐Sumuano J.T. , Silva‐Torres M.L. , Ramírez‐González B.
Published: February 2007

Abstract:  In order to alleviate the shortage of human donors, the use of porcine islets of Langerhans for xenotransplantation in diabetic patients has been proposed as a solution. To overcome rejection, we have developed a procedure for protecting the islets by combining them with Sertoli cells and placing them in a novel subcutaneous device, that generates an autologous collagen covering. A type 1 diabetic woman was closely monitored for 10 months, and then transplanted in two devices with two months of difference and a third time after 22 months. Here we present a three‐yr follow‐up. The close monitoring induced a rapid decrease in exogenous insulin requirements, which stabilized between 19 and 28 IU/d for nine months. After transplantation, the requirements reduced further to below 6 IU/d and for some weeks she was insulin free. Glycosylated hemoglobin levels decreased concomitantly. Porcine insulin could be detected in the serum after a glucose challenge and insulin positive cells inside a removed device after two yr. No complications have arisen and no porcine endogenous retrovirus infection has been detected through PCR and RT‐PCR. This case demonstrates the feasibility of using the xenotransplantation of porcine cells to alleviate metabolic complications and insulin requirements in type 1 diabetic patients.
Torsades de pointes associated with voriconazole use
Authors: Philips J.A. , Marty F.M. , Stone R.M. , Koplan B.A. , Katz J.T. , Baden L.R.
Published: February 2007

Abstract: We describe 2 patients who developed prolonged QTc interval on electrocardiogram while being treated with voriconazole. The first patient had undergone induction chemotherapy for acute myelogenous leukemia, and her course had been complicated by invasive aspergillosis and an acute cardiomyopathy. She developed torsades de pointes 3 weeks after starting voriconazole therapy. She was re‐challenged with voriconazole without recurrent QTc prolongation or cardiac dysfunction. The second patient had a significantly prolonged QTc interval while on voriconazole therapy. We recommend careful monitoring for QTc prolongation and arrhythmia in patients who are receiving voriconazole, particularly those who have significant electrolyte disturbances, are on concomitant QT prolonging medications, have heart failure such as from a dilated cardiomyopathy, or have recently received anthracycline‐based chemotherapy. The potential for synergistic cardiotoxicity must be carefully considered.
Cytomegalovirus infection with perineal pain after living donor liver transplantation: report of four cases
Authors: Sakamoto S. , Taira K. , Egawa H. , Takada Y.
Published: February 2007

Abstract: We report on 4 adult cases of presumptive cytomegalovirus (CMV) disease with perineal pain after living donor liver transplantation. Patients presented with severe perineal pain without any other symptoms related to CMV infection, except pyrexia. All patients had an episode of acute cellular rejection (ACR) before the onset of perineal pain, and 1 patient needed OKT3 therapy. The severe perineal pain was not well controlled with medication, and 1 patient needed epidural anesthesia. In the first 3 patients, pp65 CMV antigenemia (pp65CMV‐Ag) test results were positive and intravenous administration of ganciclovir (GCV) therapy was initiated. In the last patient, GCV therapy was preemptively administered before a positive pp65CMV‐Ag test result was confirmed. After administration of GCV, the pain gradually disappeared and all patients had negative pp65CMV‐Ag test results. In conclusion, unusual perineal pain can be a symptom related to CMV infection. CMV infection needs to be kept in mind when a liver transplant recipient has severe perineal pain, especially after receiving treatment for ACR.
Cryptosporidiosis in a patient on PEG‐interferon and ribavirin for recurrent hepatitis C after living donor liver transplantation
Authors: Manz M. , Steuerwald M.
Published: February 2007

Abstract: We report a case of a 48‐year‐old male who developed cryptosporidial enterocolitis while on pegylated‐interferon alfa‐2a and ribavirin for recurrent hepatitis C 2 years after living donor liver transplantation. He recovered after discontinuation of interferon and ribavirin and intermittent lowering of the immunosuppressant. We postulate that the myelodepressant effect of interferon and ribavirin in addition to an established immunosuppressive regimen permitted this opportunistic infection. To the best of our knowledge, this is the first case of cryptosporidiosis in a patient treated with interferon and ribavirin for recurrent hepatitis C after liver transplantation in the literature.
Lyme disease followed by human granulocytic anaplasmosis in a kidney transplant recipient
Authors: Assi M.A. , Yao J.D.C. , Walker R.C.
Published: February 2007

Abstract: We report the case of a kidney transplant recipient who developed Lyme disease, followed by human granulocytic anaplasmosis (HGA) 3 years later. A review of all previously published cases of Lyme disease (3 cases), HGA (5 cases), and human monocytic ehrlichiosis (HME) (5 cases) in transplant recipients is presented. Manifestations of the cases reviewed were similar to those of non‐transplant patients. There appeared to be no obvious correlation between immunosuppression and the occurrence of the illness in the transplant recipients. Serologic testing failed to make a diagnosis in 1 patient with HME in the literature and in our patient with HGA, but molecular tests established the diagnosis in both cases. Tandem infection was observed in 1 patient with two episodes of HME 2 years apart. A high index of suspicion for tick‐borne illnesses and appropriate prevention measures are needed for transplant patients with epidemiologic risk factors.
Defender, spokesperson, therapist: representing the true interest of the client in therapeutic law
Authors: Hollander Anna , Jacobsson Maritha , Sjöström Stefan
Published: February 2007

The aim of this article is to analyse the role of the legal representative in therapeutic law, specifically in Swedish administrative court hearings relating to compulsory care. Data are collected from three types of cases where a health or social welfare authority argues that it is necessary to apply coercion to a citizen: the Care of Young Persons (Special Provisions) Act, the Care of Alcohol and Drug Abusers (Special Provisions) Act and the Compulsory Psychiatric Care Act. The data consist of audio‐recordings from 39 hearings, supplemented by 28 interviews with participants in these hearings, and court documents. Three primary roles of the legal representatives are identified: defender, spokesperson and therapist. We show how the primary role of the attorney becomes that of the spokesperson, but also that the role of the therapist takes precedence over that of the defender.
Shuttling Goods, Weaving Consumer Tastes: Informal Trade between Turkey and Russia
Authors: YÜKSEKER DENIZ
Published: February 2007

In ‘top down’ conceptualizations of globalization, people often enter the analytical picture merely as resisters to globalization or as receivers of corporate produced goods, messages and ideas. This article, in contrast, focuses on a process in which ‘ordinary’ people are the active makers of global processes and meanings. I describe the transnational trade network between post‐Soviet countries and Turkey, in which Western fashions and images get circulated and transformed through the activities of informal entrepreneurs. I thus challenge accounts of globalization in which the dissemination of images is depicted as a top down process originating in corporations located in metropolitan countries. Based on ethnographic evidence collected in Istanbul and Moscow on the informal ‘shuttle trade’, I demonstrate that the mobility of ‘ordinary’ people across borders facilitates the flows of signs and images. Moreover, Western images and fashions get remoulded and acquire new meanings in the process of circulation.
Improvement of the comprehension of written information given to healthy volunteers in biomedical research: a single‐blind randomized controlled study
Authors: Paris Adeline , Nogueira da Gama Chaves Daniel , Cornu Catherine , Maison Patrick , Salvat‐Mélis Muriel , Ribuot Christophe , Brandt Christian , Bosson Jean‐Luc , Hommel Marc , Cracowski Jean‐Luc
Published: February 2007

Writing an informed consent form (ICF) for biomedical research is a difficult task. We conducted a multicenter single‐blind randomized controlled trial to identify whether a working group or the systematic improvement in lexico‐syntactic readability or an association of the two could increase the comprehension of the written information given to healthy volunteers enrolled in biomedical research. Participants were randomized to read one of four versions of the ICF: unchanged ICF (A), ICF with systematic lexico‐syntactic readability improvement (B), ICF modified by a working group (C), and ICF modified by the working group followed by systematic lexico‐syntactic improvement (D). The primary end‐point was the objective comprehension score at day 0 for each study group. The scores of objective comprehension at day 0 were statistically different between the four study groups (anovaP = 0.020). The pairwise analysis showed an improvement in the working group vs. the unchanged group (P = 0.003), and a tendency to improvement in the group who read the ICF modified using lexico‐syntactic readability and in the group who read the ICF modified using the two methods (P = 0.020 and 0.027 respectively). We conducted a two‐way anova to identify some characteristics of the population which could explain this score. There was a significant interaction between the type of informed consent document (ICD) and the gender. Improving the ICD in phase I biomedical research leads to better comprehension, whether the method used is systematic lexico‐syntactic improvement or a review by a working group. The improvement is specifically observed in men compared with women. Conversely, while both methods diverge in their effect on lexico‐syntactic readability, their association is not mandatory. We suggest that in all phase I clinical trials, the ICF be improved by either method.
Is Age Associated with the Number or Types of Medications Prescribed to Renal Transplant Recipients?
Authors: Chisholm Marie A. , Melroy Joel , Johnson Maribeth , Mulloy Laura L. , Spivey Christina A.
Published: February 2007

OBJECTIVES: To determine whether age influences the number or types of medications prescribed to younger (aged 18–64) and elderly (aged ≥65) renal transplant recipients 3 years posttransplant.

DESIGN: A cross‐sectional study involving renal transplant recipients.

SETTING: Medical College of Georgia.

PARTICIPANTS: A random sample of 100 elderly and 100 younger renal transplant recipients who received posttransplant care at the Medical College of Georgia, were on stable immunosuppressant therapy regimens, and were at least 3 years posttransplant.

MEASUREMENTS: Medical and pharmacy data of recipients were evaluated for demographics; presence of a lipid‐lowering agent; number of antihypertensives, immunosuppressants, antidiabetic agents, and total medications; number of rejections; dose per kilogram of immunosuppressant(s); infection‐related hospitalizations; and measures of blood pressure, blood glucose, serum creatinine, serum tacrolimus/cyclosporine concentrations, total cholesterol, and triglycerides.

RESULTS: Elderly recipients were more likely to have diabetes mellitus before the transplant and to develop diabetes mellitus afterwards (P=.04) and were prescribed more total medications (12.40±3.72 vs 10.25±4.07, P<.001) and antidiabetic agents (0.89±0.93 vs 0.42±0.77, P<.001) 3 years posttransplant than younger recipients. Elderly recipients also had fewer chronic rejections, more infection‐related hospitalizations, lower diastolic blood pressure, and greater fasting blood glucose levels 3 years posttransplant (P<.05) than younger recipients.

CONCLUSION: Future investigation should focus on deciphering the implications of the greater numbers of medications prescribed to elderly renal transplant recipients in terms of maximizing desired health outcomes (e.g., graft survival) and minimizing adverse drug‐related experiences (e.g., infection).
Consequences of an Intervention to Reduce Restrictive Side Rail Use in Nursing Homes
Authors: Capezuti Elizabeth , Wagner Laura M. , Brush Barbara L. , Boltz Marie , Renz Susan , Talerico Karen A.
Published: February 2007

OBJECTIVES: To examine the effect of an advanced practice nurse (APN) intervention on restrictive side rail usage in four nursing homes and with a sample of 251 residents. A secondary question explored the association between restrictive side rail reduction and bed‐related falls.

DESIGN: Pre‐ and posttest design.

SETTING: Four urban nursing homes.

PARTICIPANTS: All nursing home residents present in the nursing home at three time points (n=710, 719, and 707) and a subset of residents (n=251) with restrictive side rail use at baseline.

INTERVENTION: APN consultation with individual residents and facility‐wide education and consultation.

MEASUREMENTS: Direct observation of side rail status, resident and nurse interview for functional status, mobility, cognition, behavioral symptoms, medical record review for demographics and treatment information, and incident reports for fall data.

RESULTS: At the institutional level, one of the four nursing homes significantly reduced restrictive side rail use (P=.01). At the individual participant level, 51.4% (n=130) reduced restrictive side rail use. For the group that reduced restrictive side rails, there was a significantly (P<.001) reduced fall rate (−0.053; 95% confidence interval (CI)=−0.083 to −0.024), whereas the group that continued restrictive side rail did not demonstrate a significantly (P=.17) reduced fall rate (−0.013; 95% CI=−0.056–0.030).

CONCLUSION: An APN consultation model can safely reduce side rail use. Restrictive side rail reduction does not lead to an increase in bed‐related falls. Although side rails serve many purposes, routine use of these devices to restrict voluntary movement and prevent falls is not supported.
Ventricular Function and Long‐Term Pacing in Children with Congenital Complete Atrioventricular Block
Authors: KIM JEFFREY J. , FRIEDMAN RICHARD A. , EIDEM BENJAMIN W. , CANNON BRYAN C. , ARORA GAURAV , SMITH E. O'BRIAN , FENRICH ARNOLD L. , KERTESZ NAOMI J.
Published: February 2007

Objective: To determine the sequela of right ventricular pacing in children with congenital complete atrioventricular block.

Background: Pacing is a well‐accepted therapy for patients with congenital complete atrioventricular block. The long‐term sequela of right ventricular pacing in this population has not been well described.

Methods: We performed a cohort study on all patients with congenital complete atrioventricular block who underwent pacemaker implantation at our institution from 1972 to 2004. Patients with associated congenital heart disease or ventricular dysfunction prior to pacemaker implantation were excluded.

Results: A total of 63 patients were included in the study. The median age at pacemaker implantation was 6.5 years, with an average follow‐up of 9.9 years. The cumulative dysfunction free survival at 20 years was 92%. In total, four patients (6%) were noted to develop LV dysfunction an average of 15.1 years after pacemaker implantation. Of 30 patients who were paced for >10 years, only three (10%) developed echocardiographic evidence of LV dysfunction. Right ventricular apex pacing and prolonged QRS duration were found to be predictive of decreased long‐term LV systolic function (P < 0.05).

Conclusions: Left ventricular dysfunction in patients with congenital complete atrioventricular block is a rare finding, even in those who have been paced for more than 10 years. Right ventricular apex pacing and prolonged QRS duration may be associated with decreased ventricular function over time. At this time, with such a low incidence of cardiac dysfunction, right ventricular pacing should be considered an acceptable first‐line therapy in this population.
Incidence and Time Course of Early Recovery of Pulmonary Vein Conduction after Catheter Ablation of Atrial Fibrillation
Authors: CHEEMA AAMIR , DONG JUN , DALAL DARSHAN , MARINE JOSEPH E. , HENRIKSON CHARLES A. , SPRAGG DAVID , CHENG ALAN , NAZARIAN SAMAN , BILCHICK KENNETH , SINHA SUNIL , SCHERR DANIEL , ALMASRY IBRAHIM , HALPERIN HENRY , BERGER RONALD , CALKINS HUGH
Published: February 2007

Background: Although it is well recognized that recovery of pulmonary vein (PV) conduction is common among patients who fail atrial fibrillation (AF) ablation, little is known about the precise time course of recurrence.

Objective: To determine the incidence and time course of early recurrence of conduction after PV isolation during AF ablation.

Methods: The patient population was composed of 14 consecutive patients (9 men [64%]; age 56 ± 7 years) with AF who underwent radiofrequency catheter ablation via circumferential ablation with PV isolation, determined by a circular mapping catheter. After successful isolation of the PVs, repeat circular electrode recordings from each PV were obtained at 30 and 60 minutes.

Results:
After complete isolation of all PVs, early PV recurrence was observed in 13 (93%) patients and 26 veins (50%). Seventeen veins (33%) showed a first recurrence at 30 minutes, while nine veins (17%) showed a first recurrence at 60 minutes.

Conclusion: The results reveal an extremely high rate of early recurrence of PV conduction following AF ablation. It is particularly notable that about one‐fifth of the veins remained isolated at 30 minutes, but subsequently developed recurrence between 30 and 60 minutes. Of the veins that showed early recurrence, one‐third developed a first recurrence at 60 minutes. These findings suggest that AF ablation procedures should incorporate a 60‐minute waiting period after initial isolation in order to detect early recurrence of conduction.
Surface Electrocardiographic Patterns and Electrophysiologic Characteristics of Atrial Flutter Following Modified Radiofrequency MAZE Procedures
Authors: AKAR JOSEPH G. , AL‐CHEKAKIE M. OBADAH , HAI AFROZ , BRYSIEWICZ NEIL , PORTER MICHAEL , VARMA NIRAJ , SANTUCCI PETER , WILBER DAVID J.
Published: February 2007

Introduction: The radiofrequency MAZE is becoming a common adjunct to cardiac surgery in patients with atrial fibrillation. While a variety of postoperative arrhythmias have been described following the original Cox‐MAZE III procedure, the electrophysiological characteristics and surgical substrate of post‐radiofrequency MAZE flutter have not been correlated. We sought to determine the location, ECG patterns, and electrophysiological characteristics of post‐radiofrequency MAZE atrial flutter.

Methods: Nine consecutive patients with post‐radiofrequency MAZE flutter presented for catheter ablation 9 ± 10 months after surgery.

Results: Only one patient (11%) had an ECG appearance consistent with typical isthmus‐dependent right atrial (RA) flutter. However, on electrophysiological study, 3/9 patients (33%) had typical right counter‐clockwise flutter entrained from the cavo‐tricuspid isthmus, despite description of surgical isthmus ablation. Six patients (67%) had left atrial (LA) circuits. These involved the mitral annulus in 5/6 cases (83%) despite description of surgical mitral isthmus ablation in the majority (60%). LA flutters had a shorter cycle length compared with RA flutters (253 ± 39 msec and 332 ± 63 msec respectively, P < 0.05). After a mean of 8 ± 4 months following ablation, 8/9 patients (89%) were in sinus rhythm.

Conclusion: Up to one‐third of post‐radiofrequency MAZE circuits are typical isthmus‐dependent RA flutters, despite a highly atypical surface ECG morphology. Therefore, diagnostic electrophysiological studies should commence with entrainment at the cavo‐tricuspid isthmus in order to exclude typical flutter, regardless of the surface ECG appearance. Incomplete surgical lesions at the mitral and cavo‐tricuspid isthmus likely predispose to the development of post‐radiofrequency MAZE flutter.
Impact of Catheter Ablation of the Coronary Sinus on Paroxysmal or Persistent Atrial Fibrillation
Authors: HAÏSSAGUERRE MICHEL , HOCINI MÉLÈZE , TAKAHASHI YOSHIHIDE , O'NEILL MARK D. , PERNAT ANDREJ , SANDERS PRASHANTHAN , JONSSON ANDERS , ROTTER MARTIN , SACHER FREDERIC , ROSTOCK THOMAS , MATSUO SEIICHIRO , ARANTÉS LEONARDO , TENG LIM KANG , KNECHT SÉBASTIEN , BORDACHAR PIERRE , LABORDERIE JULIEN , JAÏS PIERRE , KLEIN GEORGE , CLÉMENTY JACQUES
Published: February 2007

Objectives: This study evaluated the impact of catheter ablation of the coronary sinus (CS) region during paroxysmal and persistent atrial fibrillation (AF).

Background: The CS musculature and connections have been implicated in the genesis of atrial arrhythmias.

Methods: Forty‐five patients undergoing catheter ablation of AF were studied. The CS was targeted if AF persisted after ablation of pulmonary veins and selected left atrial tissue. CS ablation was commenced endocardially by dragging along the inferior paramitral left atrium. Ablation was continued from within the vessel (epicardial) if CS electrograms had cycle lengths shorter than that of the left atrial appendage.

RF energy was limited to 35 W endocardially and 25 W epicardially. The impact of ablation was evaluated on CS electrogram cycle length (CSCL) and activation sequence, atrial fibrillatory cycle length measured in the left atrial appendage (AFCL) and on perpetuation of AF.

Results: Endocardial ablation significantly prolonged CSCL by 17 ± 5 msec and organized the CS activation sequence (from 13% of patients before to 51% after ablation); subsequent epicardial ablation further increased local CSCL by 32 ± 27 msec (P < 0.001). AFCL prolonged significantly both during endocardial and epicardial ablation (median: 152 to 167 msec P = 0.03) and was associated with AF termination in 16 (35%) patients (46% of paroxysmal and 30% of persistent AF). AFCL prolongation ≥5 msec and/or AF termination was associated with more rapid activity in the CS region originally: P ≤ 0.04.

Conclusion: Catheter ablation targeting both the endocardial and epicardial aspects of the CS region significantly prolongs fibrillatory cycle length and terminates AF persisting after PV isolation in 35% of patients.
Cryoablation of Congenital Familial Ectopic Tachycardia with Preservation of Atrioventircular Nodal Function in an Infant
Authors: SHAH MAULLY J , WIEAND TAMMY , VETTER VICTORIA L.
Published: February 2007

A 1‐year‐old child weighing 8 kg with familial congenital junctional ectopic tachycardia that was difficult to treat with antiarrhythmic medications underwent successful cryoablation with preservation of atrioventricular (AV) nodal function. This report describes a strategy of cryoablation in conjunction with a 3‐D mapping system and the use of atrial overdrive pacing during cryothermal application to assess AV nodal function.
Self‐ and Proxy Reports Across Three Populations: Older Adults, Persons With Alzheimer’s Disease, and Persons With Intellectual Disabilities
Authors: Perkins Elizabeth A.
Published: February 2007

Abstract  Self‐reports are often used to determine general well‐being in both research studies and practice settings. Proxy reports are also used to gain insight into the well‐being of persons with physical ill‐heath, cognitive impairments, or disabilities. The author reviews the utility and limitations of using self‐ and proxy reports across three populations: older adults, persons with Alzheimer’s disease (AD), and persons with intellectual disabilities (ID). For differing reasons, the use of self‐ and proxy reports often results in inaccuracies. Among older adults, the level of subjectivity in questions, type of relationship, and levels of carer burden may influence the outcomes, while increasing severity of dementia and decreased deficit awareness may affect data from persons with AD, and question formats, acquiescence, and level of intellectual development may affect data from persons with ID. However, generally, proxy reports can be useful in determining aspects of well‐being in people with ID, in people with AD, and in the general older population, as long as researchers keep in mind that factors that can enhance (e.g., experiences/abilities that are more objectively assessed, and attention to question format) or diminish (e.g., experiences/abilities that are more subjectively assessed, severity of dementia, and level of ID) the quality of information obtained. With respect to the use of these techniques with people with ID, the author concludes that careful attention to survey items, especially response format and wording, can greatly enhance self‐report completion and proxy concordance.
Correction for Triples in Reduced Multireference Coupled-Cluster Approaches
Authors: Paldus Josef , Li Xiangzhu
Published: February 2007

The performance of the recently proposed version of the reduced multireference (RMR) coupled-cluster (CC) method with singles and doubles (SD), which employs a modest-size configuration interaction wave function as an external source for a small subset of approximate connected three- and four-body cluster amplitudes that are primarily responsible for the nondynamic correlation effects, and which has been perturbatively corrected for the remaining triples along the same line as in the standard CCSD(T) method (Li X., Paldus J.: J. Chem. Phys. 2006, 124, 174101), referred to by the acronym RMR CCSD(T), is being tested by evaluating equilibrium spectroscopic constants for a demanding system of the beryllium dimer, as well as by computing atomization energies for several di- and triatomics. The focus is on the equilibrium properties, since it has been demonstrated earlier that the RMR CCSD method corrects well for the nondynamic correlation in bond-breaking situations. We find that in all the cases we have examined, the RMR CCSD(T) method does in fact improve the performance of CCSD(T) even in the vicinity of the equilibrium geometry. For states possessing a moderate multireference character, the improvement in computed thermochemical properties relative to CCSD(T) amounts to a few kJ/mol, a meaningful amount when striving for chemical accuracy.
Optical Properties of Gold Nanoparticles Produced by the Assembly of Size-Selected Clusters: Covering the Full Visible Wavelength Range in the Smallest Particle Size Regime
Authors: Vajda Stefan , Wiederrecht Gary P. , Bouhelier Alexandre , Tikhonov George Y. , Tomczyk Nancy , Lee Byeongdu , Seifert Sönke , Winans Randall E.
Published: February 2007

The tunability of the optical properties of small gold nanoparticles assembled from size-selected Au6-10 clusters on the surface of indium-tin-oxide glass support was studied as a function of gold particle size and shape using UV-VIS and dark-field microscopy techniques. The size and shape of gold nanoparticles was determined by employing synchrotron X-ray scattering. The obtained spectra show that a 350 nm wavelength range is accessible by proper tuning the size and shape of the studied nanoparticles with 1-2.5 nm main size and asymmetric vs symmetric form.
Game performance and intermittent hypoxic training: Table 1
Authors: Hinckson E A , Hamlin M J , Wood M R , Hopkins W G
Published: February 2007

Live high-train low altitude exposure simulated by hypoxic devices may improve athletic performance. In this study, intermittent normobaric hypoxia was achieved with the GO2altitude® hypoxicator to determine its effects on sea level performance in rugby players. Ten players were randomly assigned to two groups. Players in each group received 14 sessions of either hypoxic (10–15% O2) or normoxic (21% O2) exposure at rest over 14 consecutive days in a single blind fashion. Various performance measures were obtained consecutively in a single testing session pre- and post-exposure. Effects of hypoxic exposure on maximum speed and sprint times were trivial (<1.0%) but unclear (90% likely range, ±5% to ±9%). In rugby simulation, hypoxic exposure produced impairments of peak power in two scrums (15%, ±8%; 9%, ±7%) and impairments of time in offensive sprints (7%, ±8%) and tackle sprints (11%, ±9%). Pending further research, rugby players would be unwise to use normobaric intermittent hypoxic exposure to prepare for games at sea level.
A treatment algorithm for managing Achilles tendinopathy: new treatment options: Figure 1
Authors: Alfredson Håkan , Cook J
Published: February 2007

Achilles tendinopathy affects athletes, recreational exercisers and even inactive people. The pathology is not inflammatory; it is a failed healing response. The source of pain in tendinopathy could be related to the neurovascular ingrowth seen in the tendon’s response to injury. The treatment of Achilles tendinopathy is primarily conservative with an array of effective treatment options now available to the primary care practitioner. If conservative treatment is not successful, then surgery relieves pain in the majority of cases. Directing a patient through the algorithm presented here will maximise positive treatment outcomes.
TORSION, DIRAC FIELD, DARK MATTER AND DARK RADIATION
Authors: MAHATO PRASANTA
Published: February 2007

The role of torsion and a scalar field ϕ in gravitation, especially, in the presence of a Dirac field in the background of a particular class of the Riemann–Cartan geometry is considered here. Recently, a Lagrangian density with Lagrange multipliers has been proposed by the author which has been obtained by picking some particular terms from the SO (4, 1) Pontryagin density, where the scalar field ϕ causes the de Sitter connection to have the proper dimension of a gauge field. In this paper the scalar field has been linked to the dimension of the Dirac field. Here we get the field equations for the Dirac field and the scalar field in such a way that both of them appear to be mutually noninteracting. In this scenario the scalar field appears to be a natural candidate for the dark matter and the dark radiation.
NEW FORM OF THE KERR–NEWMAN–KASUYA SOLUTION AND ITS HAWKING RADIATION VIA TUNNELING
Authors: JIANG QING-QUAN , YANG SHU-ZHENG , WU SHUANG-QING
Published: February 2007

Parikh–Wilczek's recent work, which treats the Hawking radiation as semiclassical tunneling process from the event horizon of the static Schwarzschild and Reissner–Nordström black holes, indicates that the factually radiant spectrum deviates from the precisely thermal spectrum after taking the self-gravitation interaction into account. In this paper, we extend Parikh–Wilczek's work to study the Hawking radiation via tunneling from new form of rotating Kerr–Newman–Kasuya solution and obtain a corrected radiation spectrum, which is related to the change of Bekenstein–Hawking entropy, and is not pure thermal, but is consistent with the underlying unitary theory and then satisfies the first law of the black hole thermodynamics. Meanwhile, in this framework, we point out that the information conservation is only suitable for the reversible process.
Division of labor in a group of robots inspired by ants' foraging behavior
Authors: Labella Thomas H. , Dorigo Marco , Deneubourg Jean-Louis
Published: February 2007

In this article, we analyze the behavior of a group of robots involved in an object retrieval task. The robots' control system is inspired by a model of ants' foraging. This model emphasizes the role of learning in the individual. Individuals adapt to the environment using only locally available information. We show that a simple parameter adaptation is an effective way to improve the efficiency of the group and that it brings forth division of labor between the members of the group. Moreover, robots that are best at retrieving have a higher probability of becoming active retrievers. This selection of the best members does not use any explicit representation of individual capabilities. We analyze this system and point out its strengths and its weaknesses.
Reactive provisioning of backend databases in shared dynamic content server clusters
Authors: Soundararajan Gokul , Amza Cristiana
Published: February 2007

This paper introduces a self-configuring architecture for on-demand resource allocation to applications in a shared database cluster. We use a unified approach to load and fault management based on data replication and reactive replica provisioning. While data replication provides scaling and high availability, reactive provisioning dynamically allocates additional replicas to applications in response to peak loads or failure conditions, thus providing per application performance. We design an efficient method for data migration when joining a new replica to a running application that allows for the quick addition of replicas with minimal disruption of transaction processing. Furthermore, by augmenting the adaptation feedback loop with awareness of the delay introduced by the data migration process in our replicated system, we avoid oscillations in resource allocation.We investigate our transparent database provisioning mechanisms in the context of multitier dynamic content Web servers. We dynamically expand/contract the respective allocations within the database tier for two different applications, the TPC-W e-commerce benchmark and the RUBIS online auction benchmark. We demonstrate that our techniques provide quality of service under different load and failure scenarios.
Improvement in the Electrolytic Preparation of lodoform
Authors: Ramaswamy R. , Venkatachalapathy M. S. , Udupa H. V. K.
Published: February 2007

Use of lead dioxide anode with a graphite substrate in the electrolytic preparation of iodoform is described. Influence of bath composition, current density, temperature, and pH on the current efficiency has been investigated. Results are compared with those obtained with the conventional anodes like platinum and graphite. The effect of rotation of the anode is discussed.