bluuebunny/crossref_metadata_2025_split huggingface dataset:
MRI combined with MR cholangiopancreatography versus helical CT in the evaluation of patients with suspected periampullary tumors: a prospective comparative study
Authors: Andersson M. , Kostic S. , Johansson M. , Lundell L. , Asztély M. , Hellström M. 
Published: February 2006

Purpose: To establish the diagnostic accuracy of MRI including MR cholangiopancreatography (MRCP) compared with helical CT in the differentiation of malignant and benign lesions in the periampullary region. Material and Methods: Fifty‐one patients (27 M, 24 F, mean age 66 years, range 39–86 years) with obstructive jaundice and sonographic evidence of intra‐ and extrahepatic bile duct dilatation ( n = 31) or suspicion of periampullary tumor, based on previously performed ultrasound and/or CT examination ( n = 20), were studied. MRI with MRCP and helical CT were reviewed blindly under standardized conditions. Lesion status (differentiation of malignant versus benign) was rated on a 5‐point diagnostic confidence scale. Reference standards for comparison were findings at surgery or laparoscopy and/or the clinical outcome. The predictive value of imaging findings was determined with multivariate logistic regression analysis. Results: The areas under the receiver operating characteristic curve were 0.96 for MRI with MRCP and 0.81 for CT ( P<0.05). Multivariate analysis of eight imaging variables at MRI indicated that a stricture with malignant characteristics at MRCP was the best predictor of malignancy. Conclusion: MRI with MRCP was significantly more accurate than CT in differentiating between malignant and benign lesions in patients with suspected periampullary tumors, mainly due to the information obtained on the MRCP images of the biliary and pancreatic duct anatomy.
Effect of dose on image quality in a detector‐based dual‐exposure, dual‐energy system for chest radiography
Authors: Freund T. , Fischbach F. , Teichgraeber U. , Lopez Haenninen E. , Eichstaedt H. , Felix R. , Ricke J. 
Published: February 2006

Purpose: To assess the image quality of subtracted soft tissue and bone images of a CsI‐detector‐based dual‐energy system for chest radiography at varying dose levels. Material and Methods: We evaluated a CsI‐detector‐based, dual‐exposure, dual‐energy prototype system; 126 patients were categorized into groups of small, medium, and large. Fixed values were applied for mAs and mA. The patients were randomized into two groups with intended higher and lower speed pairs of approximately 400/1000 (high and low energy shot) and 200/500, respectively. True speed equivalents were calculated retrospectively using the detector dose. Image quality was evaluated by two highly experienced radiologists in consensus applying a rating scale of 1 to 5 for quality indicators such as image noise, residual bone structures, motion artifacts, and others. Results: Significantly decreased noise and a significant improvement for display of bone details in the bone image were noted with the higher dose, whereas a significant increase in motion artifacts reduced image quality at the higher dose. Conclusion: Radiation dose did not significantly influence the perception of dual‐energy image quality. Dual‐energy subtraction, as described, has the potential to become a future routine application in chest radiography.
Neuroradiological findings in atypical teratoid/rhabdoid tumor of the central nervous system
Authors: Cheng Y.‐C. , Lirng J.‐F. , Chang F.‐C. , Guo W.‐Y. , Teng M. M.‐H. , Chang C.‐Y. , Wong T.‐T. , Ho D. M.‐T. 
Published: February 2006

Purpose: To evaluate the computed tomography (CT) and magnetic resonance imaging (MRI) findings of atypical teratoid tumor/rhabdoid tumor (AT/RT) of the central nervous system (CNS). Material and methods: Twenty cases of CNS AT/RT have been found over the past 23 years in our hospital; these involving 11 boys and 9 girls whose mean age at diagnosis was 5.5 years. Their clinical data, the CT, and MRI findings were reviewed retrospectively. Results: AT/RT was located in the cerebellum in 15 cases. Four cases arose from the supratentorial region, while only one occurred primarily in the lumbar spinal cord. Almost all cases revealed heterogeneous intensity and heterogeneous enhancement. Peripheral cystic components were common. Survival time ranged from 2 months to 3 years, with a mean survival of 11.6 months. Conclusion: Most cases of AT/RT are located in the cerebellum. The radiologic manifestations are non‐specific. The diagnosis mainly depends on the pathologic findings. However, AT/RT should still remain in the differential diagnosis of brain tumors in young children, especially those located in the cerebellar hemisphere and with eccentric cysts.
Central line‐associated venous late effects in children without prior history of thrombosis
Authors: Ruud Ellen , Holmstrøm Henrik , Hopp Einar , Wesenberg Finn 
Published: February 2006

Abstract Background: The frequency of asymptomatic central line‐associated thromboses is high and well recognized among children with cancer, while the long‐term consequences are mainly unknown. Aim: In a cross‐sectional study, we evaluated clinical and radiological venous outcome in children with previous long‐standing intravascular catheters. Methods: The study enrolled 71 children previously treated for malignant or haematological diseases, 4–180 (median 37) mo after removal of their central lines. Inclusion criteria were a prior central line in a jugular vein for a minimum of 6 mo and no previous history of thrombosis. The children had clinical examination for post‐thrombotic syndrome (PTS) and Doppler ultrasonography of the central neck veins. Twelve children had additional venous magnetic resonance imaging (MRI). But no kind of venography was performed in the remaining. Results: We observed mild PTS with increased superficial collaterals in four children (6%), but no cases of more severe PTS. None complained of symptoms related to venous late effects. By ultrasonography, post‐thrombotic venous alterations were detected in 17 children (24%), and five of these had complete occlusion of the veins. The sensitivity for pathologically increased collaterals to identify occlusive thrombosis was 0.6, while the specificity was 0.98. Occlusive venous thromboembolism was associated with the total number of central venous lines (CVLs; p=0.002), previous severe CVL‐associated infections (p=0.001) and duration of central line in place (p=0.042). Conclusion: In spite of no prior history of thrombosis, children with previous long‐term jugular lines frequently had local thrombotic sequelae, while clinical symptoms of PTS were rare.
A Haplotype Block Model for Fine Mapping of Quantitative Trait Loci Regulating HIV‐1 Pathogenesis
Authors: Zhu Yun , Hou Wei , Wu Rongling 
Published: February 2006

The dynamic change of human immunodeficiency virus type‐1 (HIV‐1) particles that cause AIDS displays considerable variation from patients to patients. It is likely that such variation in HIV‐1 pathogenesis is correlated with the genetic architecture of hosts. Traditional genetic analysis of HIV‐1 infection is based on various biochemical approaches, but it has been little successful because HIV‐1 dynamics, as a complex trait, is under polygenic control and sensitive to environmental changes. Here, we present a novel model for integrating mathematical functions for HIV‐1 dynamics that have been well constructed into a multivariate mixture model for genetic mapping. This integrative mapping model on the foundation of linkage disequilibrium (LD)‐based haplotype block analysis provides unique power to precisely detect human quantitative trait loci (QTL) determining HIV‐1 dynamics and facilitates positional cloning of target QTL. The model allows for a number of hypothesis tests for the effects of the dynamic QTL on the virion clearance rate, the infected cell life‐span and the average viral generation time in vivo, all of which provide theoretical principles to guide the development of efficient gene therapy strategies.
Stochastic Cell
Authors: Kurakin Alexei 
Published: February 2006

AbstractAccumulating experimental evidence of stochasticity, self‐organization and abrupt non‐linear transitions underlying the dynamics of cellular structure and function is increasingly more consistent with the concepts and models of phase transitions, critical phenomena and non‐linear thermodynamics rather than with the conventional clockwork description of the cell. The novel emerging image of the stochastic cell suggests that familiar and convenient classico‐mechanical interpretations may be limiting our ability to understand the behavior of biological systems and calls for active exploration of alternative interpretational frameworks.
IUBMB Life, 57: 59‐63, 2005
Primary Platelet Adhesion Receptors
Authors: Yip Jana , Shen Yang , Berndt Michael C. , Andrews Robert K. 
Published: February 2006

AbstractThrombotic diseases such as heart attack and stroke remain a major health concern in the Western world despite existing anti‐thrombotic drugs. Current studies are revealing structure‐function relationships of primary platelet adhesion receptors mediating adhesion, activation and aggregation, and the molecular mechanisms underlying platelet thrombus formation. Platelet adhesion is relevant not only to thrombotic disease, but there is increasing evidence of a specific role for platelets in vascular processes such as inflammation and atherogenesis. This review focuses on recent advances in understanding the molecular basis for platelet thrombus formation, in particular the receptors, glycoprotein (GP)Ib‐IX‐V and GPVI, that initiate platelet adhesion and activation at high shear stress.
IUBMB Life, 57: 103‐108, 2005
The Power and Potential of Doxorubicin‐DNA Adducts
Authors: Cutts Suzanne M. , Nudelman Abraham , Rephaeli Ada , Phillips Don R. 
Published: February 2006

AbstractDoxorubicin (trade name Adriamycin) is a widely used anticancer agent which exhibits good activity against a wide range of tumors. Although the major mode of action appears to be normally as a topoisomerase II poison, it also exhibits a number of other cellular responses, one of which is the ability to form adducts with DNA. For adduct formation doxorubicin must react with cellular formaldehyde to form an activated Schiff base which is then able to form an aminal (N‐C‐N) linkage to the exocyclic amino group of guanine residues. The mono‐adducts form primarily at G of 5'‐GCN‐3' sequences where the chromophore of the drug is intercalated between the C and N base pair. The structure of the adducts has have been well defined by 2D NMR, mass spectrometry and X‐ray crystallography. The formation of these anthracycline adducts in cells grown in culture has been unequivocally demonstrated. The source of formaldehyde in cells can be endogenous, provided by coadministration of prodrugs that release formaldehyde or by prior complexation of anthracyclines with formaldehyde. Since the adducts appear to be more cytotoxic than doxorubicin alone, and also less susceptible to drug‐efflux forms of resistance, they offer new approaches to improving the anticancer activity of the anthracyclines.
IUBMB Life, 57: 73‐81, 2005
Sputum Induction Problems Identified Through Genetic Fingerprinting
Authors: Nivin Beth , O'Flaherty Tholief , Leibert Eric , Zhao Ben Yang , Driscoll Jeffrey 
Published: February 2006

Objective:To identify the contamination source of a cluster of eight positiveMycobacterium tuberculosisisolates from one laboratory session.Methods:Spoligotyping was performed onM. tuberculosisisolates processed during one laboratory session. Laboratory and sputum induction protocols and records were reviewed. Sputum induction staff were interviewed. An environmental assessment of the sputum induction booth was performed.Results:Spoligotyping identified a unique strain of susceptibleM. tuberculosisfrom five induced sputa collected at Clinic A on the same day. Three specimens processed concurrently from other clinics had spoligotypes different from each other and from the cluster strain. A laboratory investigation revealed no procedural lapses. Sputum induction records from Clinic A indicated that patient 1 in the sputum induction booth had prior culture-confirmed tuberculosis. Patient 2 had a history of a drug-resistant strain. Patient 3 had completed tuberculosis treatment, with positive cultures 7 months earlier. Patients 4 and 5 were new to the clinic and had no subsequent positiveM. tuberculosisspecimens. The sputum induction booth was working within normal parameters. Sputum induction that day was overseen by a new employee with limited training and no supervision. A review of the sputum induction protocol identified ambiguity regarding care of the ultrasonic nebulizer between patients, which may have led to reuse of the discarded nebulizer solution from patient 1.Conclusions:A break in the sputum induction protocol may have contributed to contamination of patient specimens. Sputum induction is complicated, mandating adequate staff training and supervision and patient preparation. Spoligotyping identified a potential source ofM. tuberculosiscontamination.(Infect Control Hosp Epidemiol 2002;23:580-583).
Delays in the Application of Outbreak Control Prophylaxis for Influenza a in a Nursing Home
Authors: Drinka Paul J. , Krause Peggy , Nest Lori , Gravenstein Stefan , Goodman Brian , Shult Peter 
Published: February 2006

Objective:To identify delayed prophylaxis from a preexisting database and strategies to improve performance.Setting:A skilled nursing facility with 14 floors (4 buildings). The “outbreak unit” was a 50- to 60-bed floor.Methods:We performed surveillance during six seasons using one protocol. Prophylaxis was started when influenza was cultured in the building and 10% of residents on the floor had a new respiratory illness within 7 days. We defined delayed prophylaxis as four or more residents on a floor with positive cultures whose specimens had been collected within 5 days before the application of prophylaxis.Results:We identified 14 examples of delayed prophylaxis. In three, delayed prophylaxis was related to the 3.9-day delay between culture collection and culture report. There was a high degree of commonality among building attack rates within a season. During six seasons, the first case in the last building occurred 27 to 64 days after the first case in the facility. The two seasons with the greatest activity (68 and 154 cases, respectively) began with explosive, multi-floor outbreaks in a single building. The match between the circulating strain and the vaccine was good, except in 1997-1998 when there were seven examples of delayed prophylaxis.Conclusions:Influenza may involve buildings sequentially with a commonality of building attack rates. Explosive, multi-floor outbreaks early in the season could lead to a lower threshold for prophylaxis within a larger area when initial cases are encountered later in the season. This strategy could have prevented five examples of delayed prophylaxis. Rapid testing of multiple specimens while waiting for culture confirmation could have prevented three examples of delayed prophylaxis. (Infect Control Hosp Epidemiol 2002;23:600-603).
Difference in the Incidence ofClostridium difficileAmong Patients Infected With Human Immunodeficiency Virus Admitted to a Public Hospital and a Private Hospital
Authors: Pulvirenti Joseph J. , Gerding Dale N. , Nathan Catherine , Hafiz Irfan , Mehra Tarun , Marsh Dayle , Kocka Frank , Rice Thomas , Fischer Staci A. , Segreti John , Weinstein Robert A. 
Published: February 2006

Objective:To compare the occurrence ofClostridium difficileamong inpatients infected with human immunodeficiency virus (HPV) in two different hospitals.Design:Prospective, observational study.Setting:Specialized HPV inpatient units.Patients:HIV-infected inpatients at Cook County Hospital (CCH) and Rush Presbyterian St. Luke's Medical Center (RPSLMC).Interventions:A clinical and epidemiologic assessment of patient risk factors forC. difficilewas performed.C. difficileisolates found on stool, rectal, and environmental cultures were typed by pulsed-field gel electrophoresis.Results:Twenty-seven percent of patients admitted to CCH versus 4% of patients admitted to RPSLMC had positive cultures forC. difficile(P= .001). At CCH, 14.7% of environmental cultures were positive versus 2.9% at RPSLMC (P= .002). Risk factors forC. difficileacquisition included hospitalization at CCH, more severe HrV, use of acyclovir and H2-blockers, and longer hospital stay. Patients admitted to CCH were taking more antibiotics, had longer hospital stays, and more frequently had a history ofC. difficileinfection. During the study, two strains (CD1A and CD4) extensively contaminated the CCH environment. However, only CD1A caused an outbreak.Conclusions:TheC. difficileacquisition rate at CCH was sevenfold higher than that at RPSLMC, and CCH had a more contaminated environment Differences in patient acquisition rates likely reflect a greater prevalence of traditionalC. difficilerisk factors and a concurrent outbreak at CCH. Although two strains heavily contaminated the environment at CCH, only one caused an outbreak, suggesting that factors other than the environment are important in initiatingC. difficileoutbreak.
Predominance of a Single Restriction Endonuclease Analysis Group with Intrahospital Subgroup Diversity AmongClostridium difficileIsolates at Two Chicago Hospitals
Authors: Mekonen Endale T. , Gerding Dale N. , Sambol Susan P. , Pottinger Jean M. , Pulvirenti Joseph J. , Marsh Dayle , Kocka Frank E. , Johnson Stuart 
Published: February 2006

Objective:To determine the epidemiology and relatedness ofClostridium difficileisolates in two geographically separated hospitals in a large metropolitan area, each with unique patients and personnel.Design:Observational descriptive molecular epidemiology of clinicalC. difficileisolates.Setting:Two tertiary-care hospitals in Chicago.Methods:ConsecutiveC. difficileisolates from the clinical laboratory of a Veterans Affairs hospital during a 13-month period were typed by restriction endonuclease analysis (REA). During an overlapping 3-month period, stool specimens that tested positive forC. difficiletoxin from patients at a nearby county hospital were cultured and the recovered isolates typed by the same method.Results:Nineteen (68%) of 28 nosocomial isolates at the smaller, Veterans Affairs hospital belonged to REA group K. Within this group of closely related strains, 9 distinct REA types were recognized. Twenty-one (72%) of 29 nosocomial isolates at the larger, county hospital also belonged to group K. However, the predominant REA types within group K differed markedly at each institution.Conclusions:These findings demonstrate a high degree of similarity among nosocomialC. difficilestrains from different hospitals in the same city and suggest the possibility of an extended outbreak of a prototype group K strain with subsequent genetic drift at the two different institutions.
An Outbreak of Diarrhea in a Neonatal Medium Care Unit Caused by a Novel Strain of Rotavirus: Investigation Using Both Epidemiologic and Microbiological Methods
Authors: Widdowson Marc-Alain , van Doornum Gerard J.J. , van der Poel Wim H.M. , Boer Annette S. de , Heide Reina van de , Mahdi Ulrike , Haanen Paul , Kool Jacob L. , Koopmans Marion 
Published: February 2006

Objective:In December 1999, an outbreak of diarrhea was reported in a general hospital neonatal medium care unit (NMCU) caused by a novel strain of rotavirus with genotype P[6], G9. An investigation was conducted to determine risk factors for illness among neonates.Design:Rotavirus diagnosis was by latex agglutination and typing by reverse transcriptase polymerase chain reaction. A case-control study was performed using data collected from medical records on exposures in a 3-day period before illness (cases) or a random 3-day period (controls). Environmental swabs were tested for rotavirus. Antenatal blood samples from mothers and blood samples provided by hospital staff were analyzed for rotavirus antibodies.Results:Fifty-six cases of rotaviral illness were confirmed by latex agglutination. Forty-seven of these were among 118 neonates exposed to the NMCU (attack rate, 40%). There was a 4-week period with no clinical cases in the course of the outbreak. Increased frequency (s≥ 15 times in 3 days) of ungloved nasogastric feeding was a significant risk factor (adjusted odds ratio, 8.79), controlling for birth weight and gestational age. Environmental sampling showed persistence of the virus on ward surfaces despite cleaning. None of 24 NMCU staff members had high levels of antibodies against P[6], G9. Three (8%) of 38 mothers had high antibody levels; 2 had infants who became ill. The outbreak ended with a 7-day ward closure, disinfection, and introduction of gloved nasogastric feeding.Conclusions:Case-control studies can be successful in identifying risk factors for nosocomial outbreaks of diarrhea. High levels of rotavirus antibodies in mothers may not protect infants. The environment may be the most important reservoir of rotavirus during outbreaks.
Nosocomial Infection Among Children With Symptomatic Human Immunodeficiency Virus Infection
Authors: Frota Ana Cristina Cisne , Rangel Santos Rosana Maria , Abreu Thalita Fernandes , Silva Enaldo Góes , Pessoa-Silva Carmem Lúcia 
Published: February 2006

AbstractA prospective cohort study was conducted during a 15-month period to compare nosocomial infections (NIs) among pediatric patients without (n = 989) and with (n = 50) symptomatic human immunodeficiency virus (HIV) infection. Patients with symptomatic HIV infection presented higher overall NI incidence density rates (relative risk, 1.65; P = .0001), and may represent a population at high risk for the acquisition of NI.
Clostridium difficilein Long-Term–Care Facilities for the Elderly
Authors: Simor Andrew E. , Bradley Suzanne F. , Strausbaugh Larry J. , Crossley Kent , Nicolle Lindsay E. ,   SHEA Long-Term–Care Committee
Published: February 2006

AbstractAntimicrobial agents are among the most frequently prescribed medications in long-term–care facilities (LTCFs). Therefore, it is not surprising thatClostridium difficilecolonization andC. difficile-associated diarrhea (CDAD) occur commonly in elderly LTCF residents.C. difficilehas been identified as the most common cause of non-epidemic acute diarrheal illness in nursing homes, and outbreaks of CDAD in LTCFs have also been recognized. This position paper reviews the epidemiology and clinical features of CDAD in elderly residents of LTCFs and, using available evidence, provides recommendations for the management ofC. difficilein this setting.