bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gender Disparity in the Use of Cardiac Resynchronization Therapy in the United States
Authors: ALAEDDINI JAMSHID , WOOD MARK A. , AMIN MITESH S. , ELLENBOGEN KENNETH A. 
Published: March 2008

Background: Although several studies have shown the effectiveness of cardiac resynchronization therapy (CRT) for advanced congestive heart failure (CHF), gender differences in utilization of CRT are not known.
Methods: We used the Healthcare Cost and Utilization Project (HCUP) to study national rates for admissions due to CHF along with procedures for initial CRT implantation, including both CRT‐defibrillator (CRT‐D) and CRT‐pacemakers (CRT‐P) during the years of 2002–2004. Chi‐square tests were used for comparison between number of women and men. A P < 0.05 was considered significant.
Result: Women had consistently higher rates of admission for CHF during each year (574,037 (54%) vs 482,005 (46%), 2002; 601,181 (54%) vs 517,202 (46%), 2003; and 580,913 (53%) vs 521,280 (47%), 2004). The number of initial CRT device implantations (both CRT‐D and CRT‐P) was significantly lower during each year for women compared to men (659 (25%) vs 1,931 (75%), 2002; 6,928 (26%) vs 19,646 (74%), 2003; and 11,286 (27%) vs 42,196 (73%), 2004; P < 0.01 for all). Both CRT‐P and CRT‐D were used less frequently in women compared to men; however, this difference was consistently less prominent during each year with CRT‐P compared to CRT‐D (301 (41%) CRT‐P vs 358 (19%) CRT‐D, 2002; 659 (39%) CRT‐P vs 2,530 (28%) CRT‐D, 2003; and 2,891 (39%) CRT‐P vs 8,395 (24%) CRT‐D, 2004; P < 0.05).
Conclusion: Our data clearly demonstrate a significant gender disparity in utilization of CRT devices. Further studies are needed to find possible reasons behind this disparity.
Outcome of Young Patients with Abandoned, Nonfunctional Endocardial Leads
Authors: SILVETTI MASSIMO S. , DRAGO FABRIZIO 
Published: March 2008

Background:

Transvenous leads may fail and may be extracted or abandoned. There are no reports of the outcome of children with abandoned nonfunctional leads.
Methods:

We evaluated retrospectively the outcome of these patients, in our population of pacemaker (PM) patients. Data are reported as median (range).
Results:

In 18 patients (of 245, 7%) with endocardial pacing systems implanted at 4 (0.3–19) years of age (15 VVIR and 3 DDD PM), 19 leads (16 ventricular, 3 atrial) failed (abnormal threshold increase in seven leads; exit block in nine including three atrial leads; insulation break in three) after 10 (3–15) years, and were abandoned. At 13 (6–30) years of age, seven patients received VDD PM, seven VVIR, three DDD, and one patient an epicardial system. Median number of abandoned leads is one (two in two patients). Final cross‐sectional area (CSA) of the implanted leads is eight (2–14) mm2. All the procedures were successfully completed. Follow‐up (FU) duration is 4 (1–10) years. All new leads are functioning normally. No tricuspid valve dysfunction or new venous occlusion occurred. Two cases of lead endocarditis occurred after 5 and 10 years of follow‐up in patients with two ventricular leads. No specific risk factors for endocarditis were identified.
Conclusions:

Abandonment of a nonfunctioning lead is a palliative procedure, technically feasible, with no short‐term complication. Two patients experienced late endocarditis of the leads.
Experience and Results During Transition from Radiofrequency Ablation to Cryoablation for Treatment of Pediatric Atrioventricular Nodal Reentrant Tachycardia
Authors: AVARI JENNIFER N. , JAY KATHLEEN S. , RHEE EDWARD K. 
Published: March 2008

Background: Cryoablation has emerged as a new, theoretically safer, modality for treating atrioventricular nodal reentrant tachycardia (AVNRT). The purpose of this study is to compare procedural aspects and outcomes during the transition from radiofrequency (RF) ablation to cryoablation for pediatric AVNRT.
Methods: Data were obtained retrospectively from 80 consecutive pediatric patients who underwent AVNRT ablation from 10/2001– 4/2006 (RF n = 42, Cryo n = 38). Statistical analysis was performed using unpaired t‐test, chi‐square test, and analysis of variance.
Results: RF ablations were performed anatomically in NSR while three different mapping techniques were used during cryoablation: ablation during AVNRT (26%), anatomic in NSR (48%), and anatomic with S1 S2 pacing (26%). There was no difference in the number or duration of lesions between the three cryo subgroups. Acute success was obtained in 95% of RF and 97% of cryo cases. There was no difference in the number of total, mapping, or full‐duration lesions between the RF and cryogroups. Despite accounting for longer cryolesion time, total ablation time (P < 0.001), mapping time (P = 0.002), and full duration lesion time (P < 0.001) were longer in the cryogroup. There was no significant difference in total procedure time; fluoroscopy time was shorter in the cryoablation group (P = 0.049). There was one confirmed recurrence of tachycardia in each group with a 2% recurrence rate.
Conclusions: Cryoablation for treatment of pediatric AVNRT is as safe and efficacious as RF ablation. Although cryolesions are intrinsically longer in duration, total procedure times were not increased and fluoroscopy times were decreased compared to RF.
Emergency Medicine Subinternship: Does a Standard Clinical Experience Improve Performance Outcomes?
Authors: Lampe Christopher J. , Coates Wendy C. , Gill Andrew M. 
Published: March 2008

AbstractBackground:  The emergency medicine (EM) subinternship provides a varied experience for senior medical students depending on gender, specialty choice, and interest. A didactic curriculum can be standardized, but the clinical component is difficult to control. Students can be directed to see patients with specific chief complaints.Objectives:  To assess whether a clinical requirement of 10 predetermined cases improves general knowledge as measured on an objective exam.Methods:  This was a prospective, nonrandomized, case‐controlled study at a public teaching hospital. Students were assigned to the control group (CG) or test group (TG) by alternating block rotations over 6 months. The CG saw emergency department (ED) patients according to interest and faculty direction. The TG was also required to identify ten specific chief complaints. Patient encounters were recorded in computerized logs. A 10‐question pretest assessed preexisting knowledge of each chief complaint, and a 40‐question final exam tested general EM knowledge. Descriptive statistics measured demographic data. Groups were compared by Fisher’s exact test. Difference in means testing was performed to see if pre‐ to posttest differences varied by group. Multivariate analysis controlled for gender and specialty choice.Results:  Eighteen CG students saw a mean of 57 patients, and 24 TG students saw a mean of 54 patients; 1 CG student (6%) and 7 TG students (31.8%) saw all 10 required cases (Fisher’s exact test p = 0.044). Difference in means testing demonstrated a greater relative change in performance (13.4% points) by the TG relative to the CG on a general knowledge exam, compared with their performance on a brief pretest (p = 0.014). The authors performed multivariate regression controlling for pretest score, gender, and EM specialty choice, and neither gender nor intended EM specialty choice was a contributing factor to the improved performance. A greater relative change in performance (7% points) in the TG exam score was found when compared to the CG (p = 0.020).Conclusions:  Students who participated in the usual didactic curriculum and were required to see ED patients with representative chief complaints performed better on a general EM exam than those who employed common methods of choosing patients.
TASER X26 Discharges in Swine Produce Potentially Fatal Ventricular Arrhythmias
Authors: Walter Robert J. , Dennis Andrew J. , Valentino Daniel J. , Margeta Bosko , Nagy Kimberly K. , Bokhari Faran , Wiley Dorion E. , Joseph Kimberly T. , Roberts Roxanne R. 
Published: March 2008

AbstractObjectives:  Data from the authors and others suggest that TASER X26 stun devices can acutely alter cardiac function in swine. The authors hypothesized that TASER discharges degrade cardiac performance through a mechanism not involving concurrent acidosis.Methods:  Using an Institutional Animal Care and Use Committee (IACUC)‐approved protocol, Yorkshire pigs (25–71 kg) were anesthetized, paralyzed with succinylcholine (SCh; 2 mg/kg), and then exposed to two 40‐second discharges from a TASER X26 with a transcardiac vector. Vital signs, blood chemistry, and electrolyte levels were obtained before exposure and periodically for 48 hours postdischarge. Electrocardiograms and echocardiography (echo) were performed before, during, and after the discharges. p‐Values < 0.05 were considered significant.Results:  Electrocardiograms were unreadable during the discharges due to electrical interference, but echo images showed unmistakably that cardiac rhythm was captured immediately at a rate of 301 ± 18 beats/min (n = 8) in all animals tested. Capture continued for the duration of the discharge and in one animal degenerated into fatal ventricular fibrillation (VF). In the remaining animals, ventricular tachycardia (VT) occurred postdischarge for 1–17 seconds, whereupon sinus rhythm was regained spontaneously. Blood chemistry values and vital signs were minimally altered postdischarge and no significant acidosis was seen.Conclusions:  Extreme acid–base disturbances usually seen after lengthy TASER discharges were absent with SCh, but TASER X26 discharges immediately and invariably produced myocardial capture. This usually reverted spontaneously to sinus rhythm postdischarge, but fatal VF was seen in one animal. Thus, in the absence of systemic acidosis, lengthy transcardiac TASER X26 discharges (2 × 40 seconds) captured myocardial rhythm, potentially resulting in VT or VF in swine.
Factors Associated with Helmet Use among Motorcycle Users in Karachi, Pakistan
Authors: Khan Imran , Khan Abdullah , Aziz Fatima , Islam Muhammad , Shafqat Saad 
Published: March 2008

AbstractObjectives:  Wearing a helmet is the single most effective measure for preventing head injuries in motorcycle users. The authors undertook this study to estimate compliance and determine reasons for noncompliance with helmet use among motorcyclists in their community.Methods:  This was a cross‐sectional survey of motorcyclists in three large randomly selected public‐access parking spaces across Karachi, Pakistan’s largest city. Questions covered personal demographics, frequency of helmet use, reasons for use or nonuse, and knowledge of local helmet laws. Analysis was based on frequencies and group comparisons using chi‐square test or independent sample t‐test.Results:  Of the 300 (100% male) subjects, 169 (56%) reported using helmets regularly. Users listed injury prevention (78%) as the major reason for compliance, while nonusers listed physical discomfort (44%) and limited vision (25%) as the leading reasons for noncompliance. In univariate analysis, helmet users were significantly better educated than nonusers and were more likely to believe that helmets are protective (p = 0.002) and that passengers should also wear helmets (p < 0.001). The significance of these variables persisted in multivariate analysis. Several other variables (such as mean age, marital status, and knowledge of helmet laws) did not differ between users and nonusers.Conclusions:  Helmets are underused by motorcyclists in the authors’ community. This study underscores the need for improved helmet design, public understanding, intense public education, and rigorous law enforcement in raising compliance with helmet use and minimizing the risk of preventable trauma.
Verapamil Toxicity Dysregulates the Phosphatidylinositol 3‐Kinase Pathway
Authors: Bechtel Laura K. , Haverstick Doris M. , Holstege Christopher P. 
Published: March 2008

AbstractObjectives:  Recent animal research and clinical case reports suggest benefit from high‐dose insulin therapy (HDIT) for the treatment of calcium channel blocker (CCB) toxicity. One molecular signaling pathway, the phosphatidylinositol 3‐kinase (PI3K) pathway, that contributes to CCB toxicity and the efficacy of HDIT, was examined for a role in this phenomenon.Methods:  A differentiated 3T3‐L1 adipocyte model system was utilized to characterize metabolic and molecular signaling events dysregulated in response to acute CCB toxicity. Glucose uptake assays were performed in the presence of representatives of three classes of CCB drugs, and the ability of HDIT to reverse observed inhibition was assessed. Western blot analyses were utilized to probe which insulin‐dependent signaling pathway was inhibited by CCB toxicity.Results:  Representative compounds from the dihydropyridine and phenylalkylamine classes of CCBs were more effective at inhibiting glucose uptake in differentiated 3T3‐L1 adipocytes than a representative from the benzothiazepine class. Phosphorylation at serine 473 of the Akt protein (P‐Akt), a protein representing a common pathway for insulin receptors (IR), insulinlike growth factor receptors (IGFR), and hybrid receptors formed by IR and IGFR subunits, was abolished in the presence of toxic doses of the phenylalkylamine CCB verapamil. Phosphorylation at serine 473 of Akt was rescued in the presence high concentrations of insulin.Conclusions:  These data suggest that dysregulation of the insulin‐dependent PI3K pathway is partially responsible for insulin resistance and the hyperglycemic state observed in response to acute CCB toxicity.
Quantitative computed tomography bone mineral density measurements in irradiated and non‐irradiated minipig alveolar bone: an experimental study
Authors: Verdonck Henk W. D. , Meijer Gert J. , Nieman Fred H. , Stoll Christian , Riediger Dieter , De Baat Cees 
Published: March 2008

AbstractObjective: The objective of this study was to analyse the effect of irradiation on bone mineral density (BMD).Materials and methods: All maxillary and mandibular pre‐molars and molars of six minipigs were extracted. After a 3‐month healing period, the maxilla and mandibles of three minipigs received three irradiation exposures at a total dose of 24 Gy. At 3 months after irradiation, quantitative computed tomography (QCT) was performed. As a reference, a calibration bone phantom with pre‐determined BMD was attached to the head of the minipigs. The QCT data were imported into a software program to calculate the BMD of the alveolar bone and the calibration bone phantom. In order to compare BMD values of individual minipigs, the so‐called bone mineral density quotient (BMDQ) was created, dividing the BMD value of the alveolar bone by the BMD value of the calibration bone phantom.Results: Mean BMDQ values appeared to be higher in irradiated than in non‐irradiated minipigs. However, the difference was not significant. In both irradiated and non‐irradiated minipigs, the average mandibular BMDQ values were statistically significantly higher than the average maxillary BMDQ values (P=0.003). The P‐values of the Student t‐test, determining the irradiation effect, were 0.11 for maxillary, 0.14 for mandibular, and 0.07 for overall peri‐implant BMDQ. P‐values of the non‐parametric Mann–Whitney test were all 0.05.Conclusion: It could be concluded that, 3 months after irradiation, the BMD of irradiated alveolar minipig bone was increased, when compared with non‐irradiated alveolar minipig bone. However, the increase was not statistically significant.
Osteotomy and membrane elevation during the maxillary sinus augmentation procedure
Authors: Barone Antonio , Santini Stefano , Marconcini Simone , Giacomelli Luca , Gherlone Enrico , Covani Ugo 
Published: March 2008

AbstractObjectives: The aim of the present study was to investigate in a randomized‐controlled clinical trial the performance of rotary instruments compared with a piezoelectric device during maxillary sinus floor elevation.Materials and methods: Thirteen patients who required a bilateral maxillary sinus augmentation for implant–prosthetic rehabilitation were included in this study. A within‐patient control study was carried out. The osteotomy for sinus access was performed on one side of the maxilla using the piezosurgery (test sites) and on the other side using conventional rotary diamond burs (control sites). The parameters recorded were as follows: bony window length (L), bony window height (H), bone thickness (T) and osteotomy area (A) – calculated by multiplying L and H. In addition, the time necessary for the osteotomy and sinus membrane elevation as well as the number of surgical complications were calculated.Results: The mean length and height of the bone window were similar in both groups. The osteotomy area (A) obtained by multiplying L and H was wider in the control group (151.2 ± 20.4 mm2) compared with the test group (137 ± 24.2 mm2). The time necessary for the osteotomy and the sinus membrane elevation with conventional instruments was 10.2 ± 2.4 min, while with the piezoelectric device it was 11.5 ± 3.8 min. Moreover, membrane perforation occurred in 30% of the maxillary sinuses in the test group and in 23% of the control group. None of the differences observed between the two groups reached a level of significance.Conclusions: Within the limits of the present study, it may be concluded that piezosurgery and conventional instruments did not show any differences in the clinical parameters investigated for the maxillary sinus floor elevation.
Comparing bar and double‐crown attachments in implant‐retained prosthetic reconstruction: a follow‐up investigation
Authors: Eitner Stephan , Schlegel Andreas , Emeka Nkenke , Holst Stefan , Will Joachim , Hamel Jörg 
Published: March 2008

AbstractObjectives: A removable implant‐retained dental prosthesis in an edentulous mandible can use telescopic crowns or a bar superstructure as anchorage elements for an overdenture. The aim of this study was to compare the clinical results for bar‐anchored and telescopic crown‐retained overdentures in implant prosthetic treatment of the toothless lower jaw with two or more implants placed in the intraforaminal region.Material and methods: A clinical and radiographical comparison was made of the telescope vs. the bar method for removable prosthetic rehabilitation treatments in patients with an edentulous mandible. For evaluation of the clinical data, the sulcus fluid flow rate, Periotest values, and the peri‐implant bone loss were recorded.Results: In the follow‐up examinations, 19 implant losses were reported between insertion and review of 328 implants. The frequency distribution of the observed loss rates showed no treatment‐specific trend. In the group with bar‐treated implants, failure led to ‘group loss’ of the whole prosthetic superstructure. Failure of one of the double‐crown‐stabilized full dental prosthesis could usually be adapted so that the overdenture remained usable even without re‐implantation.Conclusions: After comparing all the clinical parameters evaluated, no significant difference between the stabilization of full dentures via conus and telescopic crowns and bar‐anchored dentures could be found. The choice of one particular method remains the decision of the professional treating the patient.
Temperature changes in dental implants following exposure to hot substances in an ex vivo model
Authors: Feuerstein Osnat , Zeichner Kobi , Imbari Chen , Ormianer Zeev , Samet Nachum , Weiss Ervin I. 
Published: March 2008

AbstractObjectives: The habitual consumption of extremely hot foods and beverages may affect implant treatment modality. Our objectives were to: (i) establish the maximum temperature produced intra‐orally while consuming very hot substances and (ii) use these values in an ex vivo model to assess the temperature changes along the implant–bone interface.Materials and methods: Temperatures were measured using thermocouples linked to a computer. The thermocouple electrodes were attached to the tooth–gum interface of the interproximal areas in 14 volunteers during consumption of extremely hot foods and beverages. The in vivo measured temperature values obtained were used in an ex vivo model of a bovine mandible block with an implant and with an assembled abutment. Temperatures were measured by thermocouple electrodes attached to five locations, three of them along the implant–bone interface.Results: During consumption of a hot beverage, a maximum temperature of up to 76.3°C was recorded, and a calculated extreme intra‐oral temperature of 61.4°C was established. The ex vivo model showed a high correlation between the temperature measured at the abutment and that measured at the abutment–implant interface and inside the implant, reaching maximum temperatures close to 60°C. At the mid‐implant–bone and apical implant–bone interfaces, the maximum temperatures measured were 43.3 and 42°C, respectively.Conclusions: The maximum temperatures measured at the implant–bone interfaces reached the temperature threshold of transient changes in bone (42°C). The results of this study support the notion that intra‐oral temperatures, developed during the consumption of very hot substances, may be capable of damaging peri‐implant tissues.
Biologic width changes around loaded implants inserted in different levels in relation to crestal bone: histometric evaluation in canine mandible
Authors: Pontes Ana Emí lia Farias , Ribeiro Fernando Salimon , Iezzi Giovanna , Piattelli Adriano , Cirelli Joni Augusto , Marcantonio Jr Elcio 
Published: March 2008

AbstractObjectives: The aim of the present study was to evaluate histometric changes around dental implants inserted at different levels in relation to the crestal bone, under different loading conditions.Material and methods: Thirty‐six implants were inserted in the edentulous mandible of six mongrel dogs. Each implant was assigned to an experimental group according to the distance from the top of the implant to the crestal bone: Bone Level (at the crestal bone level), Minus 1 (1 mm below the crestal bone) or Minus 2 group (2 mm below the crestal bone). Each hemimandible was submitted to a loading protocol: conventional or immediate restoration. After 90 days, the animals were killed. Specimens were processed, and measurements were performed concerning the length of soft and hard peri‐implant tissues. Data were analyzed using ANOVA and Student's t test (α=5%).Results: Among conventionally restored sites, the distance from the most coronal position of soft tissue margin (PSTM) and first bone–implant contact (fBIC) was greater for Minus 2 than for Bone Level and Minus 1 sites (P=0.03), but significant differences were not observed among immediately restored sites. Differences among groups were not observed concerning the PSTM, and the distance from the implant–abutment junction to fBIC. Greater amounts of lateral bone loss were observed for conventionally than for immediately restored sites (P=0.006).Conclusions: These findings suggest that the apical positioning of the top of the implant may not jeopardize the position of soft peri‐implant tissues, and that immediate restoration can be beneficial to minimize lateral bone loss. Further studies are suggested to evaluate the clinical significance of these results in longer healing periods.