bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contrasting Effects of Convective Flow on Catheter Ablation Lesion Size: Cryo Versus Radiofrequency Energy
Authors: PILCHER THOMAS A. , SAUL J. PHILIP , HLAVACEK ANTHONY M. , HAEMMERICH DIETER 
Published: February 2008

Background: Cryoablation has now become an alternative to treat many cardiac arrhythmias, and may be the treatment of choice in some patient populations. We compared the effects of convective flow on large‐tip cryo and radiofrequency (RF) lesions dimensions.
Methods: Cryoablation and RF ablation were performed on porcine heart sections in a saline bath with varying directed flow rates. Cryoablation was performed for 4 minutes on 50 tissue pieces with tip temperature controlled at −80°C. RF ablation was performed on 50 tissue pieces for 60 seconds at 60°C tip temperature. The pieces were placed in culture media for 24 hours, and then sectioned, stained, and measured.
Results: Cryoablation and RF lesion sizes varied significantly with flow such that higher flow rates produced smaller cryoablation lesions and larger RF lesions (mean cryoablation volumes: 854 ± 402, 808 ± 217, 781 ± 217, 359 ± 114, and 292 ± 117 mm3, and mean RF volumes: 211 ± 35, 304 ± 79, 439 ± 125, 525 ± 187, and 597 ± 126 mm3 for 0, 1, 2, 3, and 5L/min flow rates, respectively, P < 0.0005). Trabeculated pieces had larger cryoablation lesions and smaller RF lesions than nontrabeculated ones at higher flow rate (P < 0.005). Cryoablation lesion volume increased as the time to reach −80°C decreased (r2= 0.72).
Conclusion: In contrast to RF ablation, cryoablation lesion size is smaller at high flow rates, and larger at low flow rates due to the warming effects of local convective flow. The effects of high flow are reduced in areas of trabeculation, and the time to reach −80°C predicts cryoablation lesion size.
Paroxysmal AV Block in Children with Normal Cardiac Anatomy as a Cause of Syncope
Authors: SILVER ERIC S. , PASS ROBERT H. , HORDOF ALLAN J. , LIBERMAN LEONARDO 
Published: February 2008

Background: Syncope due to episodes of paroxysmal atrioventricular (AV) block, defined as transient advanced second or third‐degree block, is rarely reported in pediatric patients without congenital heart disease.
Methods: We reviewed our institutional arrhythmia database from January 1988 to January 2007 to identify all patients less than 18 years of age with normal cardiac anatomy and episodes of syncope associated with paroxysmal AV block. Demographic and clinical information was collected.
Results: Six patients were identified (

Table I

). Five of the six patients were female, with an average age of 9.3 ± 4.4 years. Patients had episodes of syncope for an average of 5.6 ± 3.3 years prior to diagnosis. All patients had normal physical examinations, electrocardiograms, and echocardiograms. None were on medications known to interfere with AV nodal function, and laboratory evaluation including Lyme titers were negative. Five of the six patients' episodes were atypical for vasovagal syncope (except patient 6). All patients had documented paroxysmal AV block on either inpatient cardiac monitor, Holter monitor, or event recorder at the time of syncope. There was maintenance or acceleration of the sinus rate during episodes of syncope in all patients (mean atrial rate 107 ± 37 bpm). All six patients had permanent transvenous pacemakers implanted with resolution of symptoms over a mean follow‐up of 5.2 ± 6.3 years.

Characteristics of Six Patients with Paroxysmal AV Block

Patient
Age (years)
Sex
Medical History
Preceding Symptoms
Length of Symptoms (years)
Method of Diagnosis
Atrial Rate with AV Block (bpm)
Longest Pause (sec)
Pacing Mode
Follow‐up (years)

1
2.5
F
None
Crying out, headache
5
Event recorder
150
17
VVI
0.5

2
8
F
ADHD, asthma
Nausea, syncope while lying flat
6
Cardiac monitor
115
22
VVI
1.75

3
8
F
None
Nausea, syncope while lying flat
4
Cardiac monitor
75
11
VVI
16

4
9
F
None
Crying out, abdominal pain
7
Cardiac monitor
150
14
DDD
10

5
13
M
ADHD
Blurry vision and room spinning while eating
1
Event recorder
75
7
DDD
1.6

6
15
F
None
Strong emotion, sight of blood
11
Holter monitor
75
16
DDD
1.5

ADHD = Attention Deficit Hyperactivity Disorder.

Conclusion: Paroxysmal AV nodal block is a rare finding in pediatric patients, but should be considered as a possible etiology in patients presenting with episodes atypical for vasovagal syncope. Pacemaker therapy prevented future episodes in all six of our patients.
Feasibility of Magnetic Resonance Imaging in Patients with an Implantable Loop Recorder
Authors: WONG JORGE A. , YEE RAYMOND , GULA LORNE J. , SKANES ALLAN C. , ROSS IAN G. , WHITE JAMES B. , KLEIN GEORGE J. , KRAHN ANDREW D. 
Published: February 2008

Background: The implantable loop recorder (ILR) is a useful tool in the diagnosis of syncope. Our understanding of their functional and safety profile in interfering environments such as magnetic resonance imaging (MRI) becomes increasingly important as they become more prevalent.
Methods: We report four patients with an ILR who underwent MRI. The ILR memory was cleared before MRI and no changes were made to programmed settings. Device interrogation took place immediately after the scan. Patients were surveyed for device movement and heating, in addition to cardiopulmonary symptoms after their MRI.
Results: Following MRI scanning, all patients were asymptomatic and no device movement or heating was observed. In addition, the functionality of the device remained unaffected. Artifacts mimicking arrhythmias were seen in all ILR patients regardless of the type of MRI scan.
Conclusions: MRI scanning of ILR patients can be performed without harm to patient or device, but artifacts that could be mistaken for a tachyarrhythmia are seen frequently.
Transcatheter Closure of Patent Foramen Ovale in Patients with Paradoxical Embolism. Procedural and Follow‐up Results after Implantation of the Starflex® Occluder Device with Conjunctive Intensified Anticoagulation Regimen
Authors: FISCHER DIETER , FUCHS MARTIN , SCHAEFER ARND , SCHIEFFER BERNHARD , JATEGAONKAR SMITA , HORNIG BURKHARD , DREXLER HELMUT , MEYER GERD P. 
Published: February 2008

Background:

Prevalence of patent foramen ovale (PFO) is higher in patients with paradoxical embolism and associated with increased risk for recurrent thromboembolic events. By percutaneous closure of PFO, surgical closure or permanent oral anticoagulation can be avoided. So far, published series included different occluder systems and various indications and regimens of postprocedural anticoagulation. The aim of the present study was to evaluate the short‐ and long‐term results after implantation of the Starflex® occluder in patients with PFO using an intensified anticoagulation regimen.
Methods and Results:

154 patients with PFO (94 men; age: 44 ± 13 years) and >1 thromboembolic event were included. Other causes for embolism were excluded. PFO closure was successful in 147 patients (95.5%). All patients were treated with phenprocoumon (INR 2.5) and aspirin (100 mg/die) for 6 months. Transesophageal echocardiography (TEE) was repeated at 6 months. Mean clinical follow‐up period was 26 ± 18 months. After 6 months, five patients had a significant residual shunt, and five patients had suspected thrombus formation on the occluder. In three of these five patients, the occluder was surgically removed and foreign body reaction was noted. During follow‐up, nine patients suffered from neurological events (two strokes, seven transient ischemic attacks [TIA]), though complete closure of the PFO was documented by TEE. Two patients died during follow‐up; three patients had bleeding complications.
Conclusion:

Percutaneous closure of PFO in symptomatic patients by Starflex® occluder represents an effective therapy with a low incidence of periinterventional complications and recurrent thromboembolism. However, thrombus formation at the occluder system may occur in some patients despite an aggressive anticoagulation regimen.
Congenital malaria in neonates: two case reports and review of the literature
Authors: Vottier Gaelle , Arsac Marie , Farnoux Caroline , Mariani‐Kurkdjian Patricia , Baud Olivier , Aujard Yannick 
Published: February 2008

Abstract Congenital malaria is uncommon in nonendemic countries. We describe two cases involving neonates hospitalized with fever, anaemia and thrombocytopaenia. Thick and thin blood smears were positive for Plasmodium vivax (P. vivax) and P. ovale, respectively. These two cases were discussed regarding the literature and potential implications of HIV coinfection in the mother.Conclusion: Consistent data in the literature suggest that peripheral blood films should be performed in HIV‐positive women who travelled to an endemic area or with a history of malaria prior to gestation. With today's travelling patterns, congenital malaria should be considered as an important differential diagnosis of neonatal sepsis.
Excessive Copper Induces the Production of Reactive Oxygen Species, which is Mediated by Phospholipase D, Nicotinamide Adenine Dinucleotide Phosphate Oxidase and Antioxidant Systems
Authors: Yu Zhong‐Lian , Zhang Jin‐Guang , Wang Xue‐Chen , Chen Jia 
Published: February 2008

Abstract Tobacco BY‐2 suspension cells were used to study the chemical damage and its associated mechanisms caused by Cu2+. Treatment with 100 μmol/L Cu2+ generated a large amount of H2O2 and thiobarbituric acid‐reactive substances (TBARS) in cells. Using phospholipase D (PLD) specific inhibitor (1‐butanol) or phosphatidic acid (PA), we demonstrated that PLD plays an important role in the generation of H2O2 and TBARS. Semi‐quantitative reverse‐transcriptase polymerase chain reaction and enzyme activity assays with wild type and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase‐overexpressing BY‐2 cells revealed that PLD and PA are the key factors leading to NADPH oxidase activation, which is responsible for H2O2 and TBARS production induced by Cu2+. Moreover, the content of ascorbic acid (AsA), an effective antioxidant, was sharply reduced in BY‐2 cells exposed to excessive Cu2+. Furthermore, a significant downregulation of the enzymes of AsA biosynthesis and the antioxidant system was found. This evidence suggests that excessive Cu2+‐elevated reactive oxygen species (ROS) production is caused by upregulated PLD that elevates the activity of NADPH oxidase and its collapsed antioxidant systems that scavenges ROS.
ADDITION OF SULFAMETHOXAZOLE TO SELECTIVE MEDIA AIDS IN THE RECOVERY OF CAMPYLOBACTER SPP. FROM BROILER RINSES
Authors: LINE J.E. , BAILEY J.S. , BERRANG M.E. 
Published: February 2008

ABSTRACT The association of Campylobacter spp. with raw poultry products has been well established. Campy‐Line agar (CLA) is a recently developed selective culture medium that allows very few non‐Campylobacter colonies to grow. The few contaminants able to grow on CLA from typical broiler chicken carcass rinses were identified and found to be sensitive to the antimicrobial agent sulfamethoxazole (SMX). The purpose of our experiment was to determine the influence of SMX on recovery of C. jejuni from broiler carcass rinse samples when added to Campy‐Cefex agar or CLA. Cefex and CLA were prepared with and without the addition of 25 mg SMX/L media. Broiler carcass rinse samples (post‐pick, n = 80 and post‐chill, n = 80) were obtained from eight different commercial processors across the United States and were surface plated on the selective agars. Both Cefex and CLA with and without SMX recovered similar populations of Campylobacter; however, significantly fewer contaminants were observed on the Cefex with added SMX and the CLA with or without SMX compared to normal Cefex. The more selective CLA with SMX had no contaminants present from this sample type, which simplified enumeration. Addition of SMX should be considered for increasing selectivity of Campylobacter‐specific media.PRACTICAL APPLICATIONSThe addition of sulfamethoxazole to Campylobacter‐selective agar can reduce the number of contaminants on the agar and facilitate enumeration of Campylobacter colonies.
A MODIFIED COTTON‐WOOL COLUMN METHOD FOR THE RAPID RECOVERY OF DNA FROM AGAROSE GEL SLICE
Authors: LIU BAOYI , XU WEICHEN , LUO ZHIYAO , LIU QIUYUN 
Published: February 2008

ABSTRACT A previous report has described a simple and inexpensive cotton‐wool column method for the recovery of DNA from agarose gel slice. However, it takes 2 h from start to finish. Here we present a simplified version of the technique which can cut hands‐on time to within 20 min while retaining a fair DNA yield. Agarose gel slice was mashed before conducting centrifugation of the cotton‐wool column tube, which enhanced DNA yield by at least 50%. Only one spin was required with a 30–35% DNA recovery rate, a second spin after treatment of agarose sediment in the tube with microwave would add another several percent. DNA obtained can be efficiently amplified by polymerase chain reaction (PCR) or subcloned. This provides a simple, rapid and cheap alternative to commercial kits. PRACTICAL APPLICATIONSThe mashed agarose gel slice alone or with water is used for centrifugation with the best efficiency. The flowthrough can be directly used for polymerase chain reaction (PCR) amplifications, which would only take less than 10 min to obtain. The flowthrough must be ethanol precipitated if other molecular manipulations such as cloning are to be conducted, which will require another 10 min. One sample costs around 1 US cent to process with the cotton‐wool column method in developing countries. It will be a rapid and reliable alternative to expensive commercial kits.
EPITOPE ANALYSIS OF STREPTOCOCCAL M3 ANTIGEN‐SPECIFIC MONOCLONAL ANTIBODY
Authors: HONG KYONGSU 
Published: February 2008

ABSTRACT The binding domains of four monoclonal antibodies (mAbs) (4E10, 2C11, 1E10 and 3H9) specific for M3, the major protein surface antigen of Streptococcus pyogenes, were determined by Western blot analysis using truncated M3 polypeptides. The data indicate that epitopes for four mAbs are located within the B repeat block in M3 protein. A sandwich enzyme‐linked immunosorbent assay for detecting of M3 protein was established using these mAbs and polyclonal anti‐M3 antibody. The technique would be beneficial to our understanding of the epidemiology and to better control of streptococcal diseases. PRACTICAL APPLICATIONSSevere invasive diseases such as streptococcal toxic shock‐syndrome and necrotizing fasciitis have been mainly caused by M1 and M3 serotypes. The M types are also associated with acute rheumatic fever (ARF). Importantly, serotype M3 strains cause a higher rate of lethal infections than other group A streptococcus (GAS) M types. Since epitopes for four monoclonal antibodies (mAbs) are located within the B repeat block in M3 protein, assays for detecting of the epitopes using the mAbs could be helpful for the detection of severe invasive diseases or ARF.
“Congratulations, You Have Been Randomized Into the Control Group!(?)”: Issues to Consider When Recruiting Schools for Matched‐Pair Randomized Control Trials of Prevention Programs
Authors: Ji Peter , DuBois David L. , Flay Brian R. , Brechling Vanessa 
Published: February 2008

ABSTRACTBackground:  Recruiting schools into a matched‐pair randomized control trial (MP‐RCT) to evaluate the efficacy of a school‐level prevention program presents challenges for researchers. We considered which of 2 procedures would be most effective for recruiting schools into the study and assigning them to conditions. In 1 procedure (recruit and match/randomize), we would recruit schools and match them prior to randomization, and in the other (match/randomize and recruitment), we would match schools and randomize them prior to recruitment.Method:  We considered how each procedure impacted the randomization process and our ability to recruit schools into the study. After implementing the selected procedure, the equivalence of both treatment and control group schools and the participating and nonparticipating schools on school demographic variables was evaluated.Results:  We decided on the recruit and match/randomize procedure because we thought it would provide the opportunity to build rapport with the schools and prepare them for the randomization process, thereby increasing the likelihood that they would accept their randomly assigned conditions. Neither the treatment and control group schools nor the participating and nonparticipating schools exhibited statistically significant differences from each other on any of the school demographic variables.Conclusions:  Recruitment of schools prior to matching and randomization in an MP‐RCT may facilitate the recruitment of schools and thus enhance both the statistical power and the representativeness of study findings. Future research would benefit from the consideration of a broader range of variables (eg, readiness to implement a comprehensive prevention program) both in matching schools and in evaluating their representativeness to nonparticipating schools.
The Relationship Between School Absence, Academic Performance, and Asthma Status
Authors: Moonie Sheniz , Sterling David A. , Figgs Larry W. , Castro Mario 
Published: February 2008

ABSTRACTBackground:  Children with asthma experience more absenteeism from school compared with their nonasthma peers. Excessive absenteeism is related to lower student grades, psychological, social, and educational adjustment. Less is known about the relationship between the presence of asthma and the academic achievement in school‐aged children. Since students with asthma miss more days from school, this may negatively impact their academic achievement. The goal of this study was to investigate the relationships between absenteeism, presence of asthma, and asthma severity level with standardized test level performance in a predominantly African American urban school district.Methods:  A cross‐sectional analysis was conducted of 3812 students (aged 8‐17 years) who took the Missouri Assessment Program (MAP) standardized test during the 2002‐2003 academic year.Results:  After adjustment for covariates, a significant inverse relationship was found between absenteeism and test level performance on the MAP standardized test in all children (F = 203.9, p < .001). There was no overall difference in test level achievement between those with and without asthma (p = .12). Though not statistically different, those with persistent asthma showed a modestly increased likelihood of scoring below Nearing Proficient compared with those with mild intermittent asthma (adjusted odds ratio = 1.93, 95% confidence intervals = 0.93‐4.01, p = .08).Conclusions:  A negative impact of absenteeism on standardized test level achievement was demonstrated in children from an urban African American school district. Children with asthma perform the same academically as their nonasthma peers. However, those with persistent asthma show a trend of performing worse on MAP standardized test scores and have more absence days compared with other students. More research is warranted on the effects of persistent asthma on academic achievement.
Transforming growth factor‐β in cutaneous melanoma
Authors: Javelaud Delphine , Alexaki Vasileia‐Ismini , Mauviel Alain 
Published: February 2008

SummaryTransforming growth factor‐β (TGF‐β) plays a complex role during carcinogenesis. It may either act as a tumor suppressor through its broad antiproliferative potential or as a tumor promoter either via direct effects on tumor cell aggressiveness or indirectly by modulating stromal responses, angiogenesis and immune surveillance. Increased production of TGF‐β by cancer cells is often associated with tumor grade. Melanoma cells largely escape cell cycle arrest normally induced by TGF‐β in normal melanocytes, yet produce active TGF‐β and are capable of efficient transcriptional responses to the growth factor. In this review, we summarize the current knowledge about the role played by TGF‐β in melanoma progression and hypothesize about the appropriateness of targeting TGF‐β signaling for therapeutic intervention.
Acute Normovolemic Hemodilution
Authors: Goodnough Lawrence T. 
Published: February 2008

SUMMARYI Acute normovolemic hemodilution is a point of care method of autologous blood procurement. Acute hemodilution has several inherent advantages over preoperative autologous blood donation: it is inexpensive, does not require testing, and has none of the risks of administrative error or bacterial contamination related to stored blood. The clinical efficacy of acute hemodilution is increasingly apparent. This technique will also serve as a foundation for the use of emerging oxygen carrying solutions.
Transfusion Alternatives in Trauma
Authors: Biffl Walter L. , Moore Ernest E. 
Published: February 2008

SUMMARYRestoration of oxygen‐carrying capacity plays an essential role in the management of trauma patients. The potential risks associated with allogeneic blood, as well as the immunosuppressive potential of transfusions, have stimulated interest in alternatives to allogeneic blood transfusion. In the setting of trauma, the feasible alternatives are limited to autotransfusion and blood substitutes. Autotransfusion avoids infectious risks and obviates compatibility testing. However, coagulopathy remains a significant problem associated with autotransfusion. Hemoglobin substitutes offer many theoretical advantages over allogeneic transfusion. Several formulations have been investigated in clinical trials. Our experience has been exclusively with a polymerized, pyridoxylated stroma‐free human hemoglobin‐based solution (PolyHeme). In infusions up to 10 units (5 liters) PolyHeme has proved an adequate oxygen carrier without serious adverse effects, and has reduced the need for allogeneic blood. Given its safety, efficacy, and favorable immunomodulatory profile, PolyHeme appears to have tremendous potential as an alternative to transfusion.
Transfusion Alternatives in Orthopedic Surgery
Authors: Earnshaw Peter H. 
Published: February 2008

SUMMARYThe volume of orthopedic surgery is large and growing ‐ over 200,000 hip and knee arthroplasties were performed in the USA alone last year ‐ and these patients are at particularly high risk of requiring a blood transfusion. Orthopedic surgeons can significantly reduce the amount of allogeneic blood transfused by following simple guidelines. Accurate data gathering has allowed us to better target those most at risk. A wide range of strategies is available including, but not limited to, review of transfusion triggers, autologous predonation, hemodilution techniques, blood salvage and the use of perioperative erythropoietin. Some techniques are particularly suited to orthopedic surgery and the use of an algorithm can help us to select the best approach for the individual patient.
Anemia and Cardiovascular Disease
Authors: Wahr Joyce A. 
Published: February 2008

SUMMARYCardiovascular disease accounts for the majority of deaths each year in Westernized countries. Anemia, with its obligatory increase in cardiac output, may present a special risk in these patients. A review of the physiology of acute and chronic anemia as well as the physiology of myocardial ischemia is presented, as is also a review of the literature regarding the risks and recommendations for therapy in this group of high‐risk patients.