bluuebunny/crossref_metadata_2025 huggingface dataset:
Custom Total Knee Replacement in a Dog with Femoral Condylar Bone Loss
Authors: LISKA WILLIAM D. , MARCELLIN‐LITTLE DENIS J. , ESKELINEN ESA V. , SIDEBOTHAM CHRISTOPHER G. , HARRYSSON OLA L. A. , HIELM‐BJÖRKMAN ANNA K.
Published: June 2007

Objective— To report surgical planning, technique, and outcome of custom total knee replacement (TKR) performed to manage a medial femoral condylar nonunion in a dog.

Study Design— Clinical case report.

Animal— A 3‐year‐old, 20 kg Karelian Bear Hound.

Methods— Computed tomographic scan of the left pelvic limb was used to build a stereolithography model of the distal portion of the femur. The model was used to create a custom augment to replace the missing medial femoral condyle and a custom stem for intramedullary condylar cemented fixation. The augment and stem were adapted to femoral and tibial components already available. The model was used to rehearse the surgery and then the custom prosthesis was implanted.

Results— Weight bearing returned 8 hours after surgery and improved thereafter. Joint alignment was normal and prosthetic joint motion was 60–165° postoperatively. The dog resumed moose hunting 3 months after surgery. Peak vertical force and impulse of the operated limb measured 17 months after surgery were 65% and 47% of the normal, contralateral limb.

Conclusion— Based on short‐term follow‐up, cemented canine TKR was successfully achieved for management of a severely abnormal stifle joint.

Clinical Relevance— With further refinement and development of commercially available prostheses, TKR should be possible for canine patients.
Reclassification of Small Intestinal and Cecal Smooth Muscle Tumors in 72 Dogs: Clinical, Histologic, and Immunohistochemical Evaluation
Authors: MAAS CERIEL P.H.J. , TER HAAR GERT , VAN DER GAAG INGRID , KIRPENSTEIJN JOLLE
Published: June 2007

Objectives—To reclassify canine small intestinal and cecal leiomyoma (LM) and leiomyosarcoma (LMS) into smooth muscle and gastrointestinal stromal tumors (GIST) using histologic and immunohistochemical (IH) analysis and to report clinical findings and survival data.

Study Design—Retrospective review of cases.

Animals—Dogs (n=47) with small intestinal (40 LMS; 7 LM) and 25 dogs with cecal tumors (23 LMS; 2 LM).

Methods—Clinical and survival data were reviewed. Tissue sections were reevaluated for light‐microscopic malignancy criteria and examined for expression of SMA, desmin, vimentin, S‐100, and CD117 (KIT) by immunohistochemistry.

Results—Reclassification resulted in 2 LM, 9 LMS, 19 GIST, and 17 GIST‐like tumors in the small intestine and 23 GIST and 2 GIST‐like tumors in the cecum. GIST‐like tumors were morphologic and IH identical to GIST but lacked KIT expression. No significant difference in survival was observed for tumor type, location, histologic, or IH characteristics; however, dogs with cecal tumors were significantly older in age, presented more commonly with intestinal perforation and peritonitis, and less commonly with weight loss. Cecal tumors had more histologic malignancy criteria than small intestinal tumors. After excision, 1 and 2 year recurrence‐free periods were 80.1% and 67.2% for small intestinal and 83.3% and 61.9% for cecal tumors.

Conclusion—Prognosis for intestinal tumors with histologic smooth muscle appearance is good after excision and not related to tumor type, location, histologic, or IH characteristics.

Clinical Relevance—Clinical importance could not be demonstrated for reclassification, but may be for future treatment, of intestinal smooth muscle or stromal tumors.
Effect of 9 mm Tibial Tuberosity Advancement on Cranial Tibial Translation in the Canine Cranial Cruciate Ligament‐Deficient Stifle
Authors: MILLER JONATHAN M. , SHIRES PETER K. , LANZ OTTO I. , MARTIN ROBERT A. , GRANT J. WALLACE
Published: June 2007

Objective— To assess the effect of 9 mm tibial tuberosity advancement (TTA) on cranial tibial translation (CTT) in a cranial cruciate ligament (CCL)‐deficient canine stifle model.

Study Design— In vitro cadaveric study.

Animals— Canine pelvic limbs (n=12).

Methods— Each stifle was placed in a jig at 135° with a simulated quadriceps force and tibial axial force. CTT distance was measured with the CCL intact (iCCL), transected (tCCL), and after performing TTA using a 9 mm cage.

Results— Mean CTT for iCCL was 0.42 mm, 1.58 mm after severing the CCL, and 1.06 mm post‐TTA. The tCCL CTT measured without any quadriceps force was 2.59 mm. Differences between the intact and tCCL (P<.0001) and tCCL and TTA (P=.0003) were significant. The difference between the tCCL with and without the quadriceps force was not significant (P=.0597).

Conclusions— These data confirm that TTA does reduce CTT in tCCL stifles in this model. The CTT noted was less than that noted clinically. The addition of a simulated quadriceps force to a CCL‐deficient stifle before a TTA, by itself, may not significantly lessen CTT.

Clinical Relevance— Whereas this in vitro model demonstrated that TTA reduced CTT in canine stifles with CCL transected, the model limitations preclude extrapolation to the effect of TTA in a live dog.
Surgical Stapling Devices in Veterinary Medicine: A Review
Authors: TOBIAS KAREN M.
Published: June 2007

Objectives—To review indications, benefits, and complications of surgical stapling in animals.

Study Design—Literature review.

Results—Benefits and complications of surgical stapling depend on the procedure performed. Use of surgical staplers does not improve wound strength but may decrease surgical time.

Clinical Relevance—In patients at significant risk for intraoperative contamination or morbidity from prolonged anesthesia time, use of stapling devices should be considered.
Evaluation of Agreement Between Numerical Rating Scales, Visual Analogue Scoring Scales, and Force Plate Gait Analysis in Dogs
Authors: QUINN MARGARET M. , KEULER NICHOLAS S. , LU YAN , FARIA MARIA L. E. , MUIR PETER , MARKEL MARK D.
Published: June 2007

Objective—To evaluate the accuracy of numerical rating (NRS) and visual analogue (VAS) scoring scales compared with force plate gait analysis and agreement between observers for each scoring scale.

Study Design—Experimental study.

Animals—Mixed breed dogs (n=21) with a right limb tibial osteotomy repaired with an external fixator.

Methods—Three small‐animal veterinarians with orthopedic training scored lameness using NRS and VAS before surgery, and at 4 and 8 weeks after surgery. Peak force and impulse were determined at the same time points using a force plate. Agreement between observers and with force plate data was assessed. Significance was set atP≤.05.

Results—Agreement was generally low among observers for both NRS and VAS scores. When evaluated at each time point, an acceptable level of agreement was present only at 4 weeks after surgery. Only impulse had a significant relationship with some of the observers' subjective scores. No significant relationships between any observer's scores and force plate data existed if very lame dogs were omitted.

Conclusions—Subjective scoring scales do not replace force plate gait analysis. Agreement is low unless lameness is severe, and each observer uses an individually unique scale. Subjective scoring scales most accurately reflect force plate gait analysis when lameness is severe.

Clinical Relevance—Subjective lameness scoring scales may not accurately reflect lameness and do not replace force plate gait analysis. Observers must stay the same during the duration of a study for accurate analyses.
In Vitro Mechanical Comparison of Screwed, Bolted, and Novel Interlocking Nail Systems to Buttress Plate Fixation in Torsion and Mediolateral Bending
Authors: LANSDOWNE JENNIFER L. , SINNOTT MICHAEL T. , DÉJARDIN LOIC M. , TING DENNIS , HAUT ROGER C.
Published: June 2007

Objective—To compare standard interlocking nails (ILN) with a newly designed ILN featuring an angle‐stable locking mechanism (ILNn).

Study design—Six experimental groups.

Sample population—Bone models (n=48) treated with 6 and 8 mm nails locked with screws or bolts (ILN6s, ILN8s, ILN6b, ILN8b, respectively), ILNn, and a 3.5 mm broad‐DCP (br‐DCP); n=4/testing mode.

Methods—Specimens were tested in torsion or 4‐point bending. Construct compliance, deformation, and slack were statistically compared (P<.05).

Results—Regardless of testing mode, construct compliance was greater with smaller ILN. Screwed constructs were more compliant than bolted ones, with a significant difference between ILN6s and ILN6b in torsion. Plated constructs were significantly more compliant than the ILNn. Angular deformation was consistently greater with smaller ILN. Screwed ILN constructs sustained ∼2 × the torsional deformation of the bolted ones (∼36° [ILN6s] versus ∼18° [ILN6b]). Comparatively, ILNn constructs had significantly less torsional (∼8°) and bending (∼4°) deformation than other constructs. Whereas standard ILN constructs had slack in both modes, ILNn and br‐DCP construct deformations consistently occurred without slack.

Conclusions—Use of bolts rather than screws improved ILN mechanical behavior, but neither locking mechanism completely counteracted torsion and bending forces. Conversely, the ILNn angle‐stable locking system eliminated torsional and bending slack, resulting in comparable mechanical performances between ILNn and plated constructs.

Clinical Relevance—The angle‐stable locking mechanism of the new ILN eliminates all slack in the system; thus, interfragmentary motion will likely be reduced compared with standard ILN, which may improve the local environment for fracture healing.
Effective molecular RHD typing strategy for blood donations
Authors: Polin Helene , Danzer Martin , Hofer Katja , Gassner Waltraud , Gabriel Christian
Published: June 2007

BACKGROUND: More than 50 weak D alleles and numerous partial D alleles have been described to date that can be identified by molecular methods as polymerase chain reaction (PCR) and DNA sequencing of the RHD gene. A real time–based RHD typing scheme was developed and tested during an 8‐month period.

STUDY DESIGN AND METHODS: A total of 53,347 blood donors and patients were tested with standardized immunohematologic methods. A total of 201 DNA samples with weak D reactions underwent molecular characterization by weak D real‐time PCR, exon‐screening real‐time PCR, and nucleotide sequencing of RHD Exons 1 through 10. A total of 2,427 samples with D– phenotype were tested for the presence of RHD markers.

RESULTS: Molecular typing of 201 samples with weak D expression revealed 15 different known aberrant alleles as well as one new weak D type dubbed weak D Type 49. Approximately 60 percent of the alleles were determined as weak D Types 1 through 3 and detected by only one amplification run. Weak D Type 1 represented the most frequent allele (n = 72). Three samples with D– phenotype showed amplification of RHD‐specific markers. Sequence‐based typing (SBT) of these samples revealed a DEL allele, RHD(IVS3+1G>A), in two samples and one weak D Type 4.3.

CONCLUSIONS: The presented scheme for RHD genotyping of weak D red blood cell units was reliable for detection of aberrant alleles. Testing of D– blood samples as quality control seems to overcome limitations of standard serology by detection of samples with weak D or DEL phenotype.
The impact of universal leukodepletion of the blood supply on hemovigilance reports of posttransfusion purpura and transfusion‐associated graft‐versus‐host disease
Authors: Williamson Lorna M. , Stainsby Dorothy , Jones Hilary , Love Elizabeth , Chapman Catherine E. , Navarrete Cristina , Lucas Geoff , Beatty Cynthia , Casbard Angela , Cohen Hannah ,   the Serious Hazards of Transfusion Steering Group
Published: June 2007

BACKGROUND: The pathogenesis of posttransfusion purpura (PTP) and transfusion‐associated graft‐versus‐host disease (TA‐GVHD) involves patient exposure to donor platelets (PLTs) and T lymphocytes, respectively, which are removed during blood component leukodepletion (LD).

STUDY DESIGN AND METHODS: Reports of PTP and TA‐GVHD to the UK hemovigilance scheme Serious Hazards of Transfusion (SHOT) from 1996 to 2005 were compared before and after implementation of universal LD during 1999.

RESULTS: There were 45 reports of PTP, with a mean of 10.3 per year before universal LD and 2.3 per year afterward (p  < 0.001). All patients had received red cells, but before universal LD, only 1 of 31 (3%) cases had also received PLTs, compared to 8 of 14 (57%) afterward (p  < 0.001). Thirty‐four cases (76%) had human platelet antigen (HPA)‐1a antibodies, whereas 11 had antibodies to other HPA specificities, only 1 of which occurred after LD. Two cases reported before LD also had heparin‐dependent PLT antibodies. There were 13 reports of TA‐GVHD, all fatal, of which only 2 cases of undiagnosed immunodeficiency met current UK criteria for irradiated components. Eight others had one or more risk factors: B‐cell malignancy (6), steroids (1), fresh blood (1), and donor‐recipient HLA haplotype share (4). Eleven cases were due to non‐LD and 2 to LD components (p  < 0.001). No cases have been reported since 2001. In an additional 405 cases, nonirradiated components were transfused in error to high‐risk recipients, mainly on fludarabine, but none developed TA‐GVHD.

CONCLUSIONS: These findings suggest that universal LD has further reduced the already low risk of TA‐GVHD in immunocompetent recipients and has altered the profile of PTP cases.
Nonfatal intravascular hemolysis in a pediatric patient after transfusion of a platelet unit with high‐titer anti‐A
Authors: Harris Shealynn B. , Josephson Cassandra D. , Kost Christine B. , Hillyer Christopher D.
Published: June 2007

BACKGROUND: In the pediatric population, hemolysis after out‐of‐group platelet (PLT) transfusion is a potentially fatal event that is thought to be underrecognized. Group A patients transfused with group O single‐donor PLTs (SDPs) with “high‐titer” anti‐A are at greatest risk for hemolysis.

STUDY DESIGN AND METHODS: A clinical and serologic evaluation of a pediatric patient with hemolysis of initially unknown etiology was conducted. Retrospective testing for anti‐A titer of an admission sample and a transfused group O SDP was performed.

RESULTS: The group A patient (previously group O) was found to have a history of engrafted major ABO‐mismatched hematopoietic peripheral blood progenitor cell transplant (HPBPCT). Immune‐mediated intravascular hemolysis with a delayed presentation was determined. Testing identified passive anti‐A in the patient's plasma and high‐titer anti‐A (IgG 4096, IgM 256) in the group O SDP unit.

CONCLUSION: Hemolysis after out‐of‐group SDP transfusion may be delayed in presentation and, thus, clinically unrecognized. When evaluating these cases, the limitations of routine type and screen for detection of passive anti‐A must be considered. Group A individuals with a history of engrafted major ABO‐mismatched HPBPCT potentially have increased susceptibility to hemolysis from group O SDP transfusion due to their lack of tissue and soluble A antigen.
Single Chamber Atrial Pacing: A Realistic Option in Sinus Node Disease: A Long‐Term Follow‐up Study of 213 Patients
Authors: HÖIJER CARL J. , HÖGLUND PETER , SCHÜLLER HANS , BRANDT JOHAN
Published: June 2007

Background:

Despite several decades of experience with atrial pacing, many centers do not apply this mode to any greater extent, mainly because of concerns for the development of future atrioventricular (AV) block or atrial fibrillation. Recent studies have emphasized possible negative effects of right ventricular stimulation, even when AV‐synchrony is preserved, and have thus given rise to renewed interest in single chamber atrial pacing for sinus node disease.

Methods:

This study presents the results of up to 19 years' follow‐up of 213 patients with sinus node disease treated with atrial pacing with respect to survival and causes of death, development of atrial fibrillation and AV block, and total mode survival. Patients were divided into two groups: with or without associated atrial tachyarrhythmias at the time of implant. Results are given for all patients and for the two groups separately.

Results:

The mean follow‐up time was 10.1 years. The survival of the entire group was lower after 10 years than that of an age and gender‐matched general Swedish population. This was caused by patients with the brady‐tachy syndrome (BT) having a significantly higher mortality rate than controls, whereas those with bradycardia only (B) had survival comparable to the general population. Permanent atrial fibrillation (AF) developed in 20% of patients and was significantly more common in patients with BT. The majority of patients with AF (78%) no longer needed any pacing, i.e., did not require ventricular stimulation due to slow ventricular rate. The annual incidence of high grade AV block was 1.8%. If patients with preexisting bundle branch block were excluded, the incidence was 1.6%. No fatal episode of AV block was seen. The overall mode survival at the end of follow‐up was 75%, with 155 patients still with atrial pacemakers.

Conclusion:

Atrial pacing is a safe and reliable mode of pacing in patients with sinus node disease, even in the very long‐term.
Bradypacing: Indications and Management Challenges in Nigeria
Authors: THOMAS M.O , OKE D.A , OGUNLEYE E.O , ADEYANJU F.A
Published: June 2007

Background:

Permanent pacemaker implantation is a life‐saving procedure that is performed worldwide. There is paucity of reports on pacemaker surgery in Nigeria. The aims of the study were to determine the indications for pacemaker insertion, the demographic distribution of the patients requiring it, the electrocardiographic (ECG) changes, and the management challenges in Nigeria.

Materials and Method:

One hundred consecutive patients who had pacemaker insertion done by our team from 1999 were included in the study. The patients' biodata, indications for pacemaker insertion, ECG changes, and the treatment profile were recorded.

Results:

There was female preponderance (93.0%) among the patients studied. Third‐degree heart block was the indication in 86.0% of the patients and most patients did well with single lead ventricular pacing which is generally cheaper than the dual chamber pacing.

Conclusion:

The majority of bradyarrhythmia patients in this environment can be maintained on single lead ventricular pacemaker.
Early Detection of Regional Myocardial Dysfunction in Paced Children With Congenital Complete Atrioventricular Block
Authors: TUZCU VOLKAN , BODTKE JIMMY P , BEST THOMAS H
Published: June 2007

Background:

Right ventricular apical pacing leads to global left ventricular dysfunction. Assessment of regional myocardial function may allow for earlier detection of pacing‐induced myocardial remodeling. The aim of this study was to evaluate regional myocardial function in paced children with congenital complete atrioventricular block (CCAVB).

Methods:

We investigated regional myocardial function using strain echocardiography and tissue velocity imaging in 10 paced children with CCAVB and in 14 age‐matched healthy children. Echocardiograms of the paced children were obtained during intrinsic junctional rhythm.

Results:

All patients had normal biventricular size and global function. The time from R wave to peak regional strain rate and the time from R wave to peak regional myocardial tissue velocity were measured in nine segments. The differences between maximum and minimum values were used as a measure of contraction delay (dSR and dTV). Study group patients had significantly higher dSR and dTV values compared to the control group. Mean peak strain rates and peak tissue velocities obtained from same segments were significantly decreased in the study group compared to the control group. Regional dysfunction was more prominent in the areas of ventricular pacing. No significant correlation is found between the duration of pacing (2.5–18 years) and dSR, dTV, mean peak strain rates, or mean peak tissue velocities.

Conclusion:

Pacing leads to regional myocardial dysfunction that can be detected with strain echocardiography and tissue velocity imaging during intrinsic junctional rhythm in children with CCAVB. Pacing‐induced regional myocardial remodeling does not seem to progress with long‐term right ventricular pacing in children with CCAVB.
Cardiac Autonomic Modulation Evaluated by Heart Interval Variability is Unaltered but Subtly Widespread in the Indeterminate Chagas' Disease
Authors: CORREIA DALMO , JUNQUEIRA LUIZ FERNANDO , MOLINA RODRIGO JULIANO , PRATA ALUÍZIO
Published: June 2007

Background:Cardiac autonomic function in the indeterminate chronic form of Chagas' disease deserves better clearing‐up and understanding, since the existing findings are scarce and controversial. This work analyzed the short‐term heart interval variability in order to verify the cardiac autonomic modulation in indeterminate Chagas' disease subjects examined in a Brazilian endemic area.

Methods:Variability in time and frequency domain of 5‐minute electrocardiogram (ECG) series of R‐R intervals in supine and active standing positions were obtained from 18 age‐, gender‐, body mass index‐, lifestyle‐, and physical activity‐matched chagasics and 18 control healthy subjects examined in Água Comprida city, MG, Brazil. Mann‐Whitney test was used for analysis of the data and spread of the individual indices in both groups.

Results:The median of the all variability indices in the chagasic group were statistically similar (P= 0.17–0.87) to that in the control group. A wide dispersion of the almost all individual indices values, ranging from normal to variably reduced or increased ones, was noted in the majority of the chagasics in relation to the control interquartile range, in both postural positions.

Conclusion:As a group, indeterminate Chagas' disease subjects showed unaltered short‐term heart interval variability. Individual somewhat widespread of majority of time‐ and frequency‐domain indices, from depressed to exacerbated ones appears to exist. This conforms to a variable cardiac autonomic modulation in this form of disease, suggesting that the majority of chagasics has no lesions, and a minority has subtle lesions of the efferent innervation‐sinus node complex.
Heart Rate Turbulence After Short Runs of Nonsustained Ventricular Tachycardia in Chronic Heart Failure
Authors: FLEVARI PANAYOTA , GEORGIADOU PANAGIOTA , LEFTHERIOTIS DIONYSSIOS , LIVANIS EFTHIMIOS , THEODORAKIS GEORGE , TH KREMASTINOS DIMITRIOS
Published: June 2007

Background:

Heart rate turbulence (HRT) following isolated premature complexes is a baroreceptor‐mediated prognostic marker. Short runs of spontaneous, nonsustained ventricular tachycardia (nsVT) exert a greater hemodynamic effect than extrasystoles and may trigger a more potent turbulence‐like response (HRTVT), possibly related to other risk‐related markers, such as heart rate variability (HRV), left ventricular ejection fraction (EF), and original HRT parameters (turbulence slope [TS] and turbulence onset [TO]).

Methods:

We studied 27 patients with heart failure (HF) and nsVT (4–7 beats) on 24‐hour Holter electrocardiographic recordings (mean age 58 ± 3.6 years, EF 36%± 5.0%). Following nsVT, TSVT and TOVT were measured according to the original definitions. HRV, TS, and TO were also assessed.

Results:

HRTVT parameters were related to HRV. A significant relation existed between TSVT and EF (r= 0.66, P < 0.05). HRTVT parameters were related to the originally described (TS and TO), whereas TOVT was higher than TO (1.63 ± 1.6 vs −1.7 ± 0.65, P < 0.05).

Conclusions:

In mild‐to‐moderate HF, turbulence is observed following short nsVT runs and is related to prognostically important HRV indexes and EF. HRTVT is similar to HRT but TOVT is shifted toward more positive values than TO. HRTVT might be prognostically significant.
A Wide QRS Complex Tachycardia with Different Initiation Patterns: What is the Mechanism?
Authors: YAMADA TAKUMI , PLUMB VANCE J , MCELDERRY HUGH T , KAY G. NEAL
Published: June 2007

A 47‐year‐old man with palpitations underwent electrophysiologic testing (EPS). Burst atrial pacing while infusing isoproterenol induced non‐reproducible wide QRS tachycardias with an unusual pattern of an H‐A‐V activation with the same tachycardia cycle length and two different initiation patterns. The tachycardia had the earliest atrial activation at the His bundle region. No dual atrioventricular (AV) nodal physiology was demonstrated by programmed atrial stimulation. Though a definite diagnosis of AV nodal reentrant tachycardia was not obtained, slow pathway ablation was performed in order to avoid inadvertent AV block as a complication. Thereafter, no tachycardias were induced by repeat burst atrial pacing.
Sustained Ventricular Tachycardia in Apical Hypertrophic Cardiomyopathy, Midcavitary Obstruction, and Apical Aneurysm
Authors: SANGHVI NEIL K , TRACY CYNTHIA M
Published: June 2007

The prevalence of hypertrophic cardiomyopathy is estimated at 1:500 in the general population. Of these patients, approximately 1% develops midcavitary obstruction and subsequent apical aneurysm. We present a brief review of the literature on apical hypertrophic cardiomyopathy (HCM) using a rare case‐based example. The etiology for apical aneurysm development is unclear but is thought to extend from apical fibrosis and necrosis secondary to subendocardial ischemia. The lifetime risk of cardiovascular death in patients with HCM is 2%. However, the risk may be higher in patients with apical aneurysms. Definitive therapy involves implantation of an automatic implantable cardioverter defibrillator, since medical therapy has variable success.
Visualizing Pacemaker‐Induced Phrenic Nerve Stimulation with Acoustic Cardiography
Authors: TOGGWEILER STEFAN , KOBZA RICHARD , ROOS MARKUS , ERNE PAUL
Published: June 2007

This case study illustrates that acoustic cardiography—a simple non‐invasive test—can be applied in any diagnostic setting as well as during biventricular pacemaker implantation to ensure that the pacemaker settings are not leading to phrenic nerve stimulation.
Focal Atrial Tachycardia from the Fossa Ovalis in a Patient with Bachmann's Bundle Block
Authors: MAURY P , RACZKA, M.D. F
Published: June 2007

We report the case of a patient with tracings during sinus rhythm compatible with block of the Bachmann's bundle and presenting with focal atrial tachycardia arising from the fossa ovalis with successful ablation on the right side of the septum. Upward activation of the left atrium has been related in this case to the block of the Bachmann's bundle and to the lack of transseptal conduction.
Inferior Vena Cava Approach to Permanent Pacemaker Implantation
Authors: BRUECK MARTIN , BANDORSKI DIRK , KRAMER WILFRIED , RAUBER KLAUS
Published: June 2007

A 89‐year‐old woman required permanent pacemaker implantation because of symptomatic bradyarrhythmia with multiple falls and repeated fractures. Because of the obstruction of the thoracic veins and infection of both groins, an alternative approach via directly punctured inferior vena cava was performed. At follow‐up, the patient remained well with an excellent symptomatic response to pacing. The method seems simple to perform and is an alternative when the usual pectoral implantation site is inaccessible.
Occurrence of “J Waves” in 12‐Lead ECG as a Marker of Acute Ischemia and Their Cellular Basis
Authors: RITUPARNA SHINDE , SURESH SHINDE , CHANDRASHEKHAR MAKHALE , PURVEZ GRANT , SUNIL SATHE , DURAIRAJ M. , YASH LOKHANDWALA , DI DIEGO J.M , CHARLES ANTZELEVITCH
Published: June 2007

The “J wave” (also referred to as “the Osborn wave,”“the J deflection,” or “the camel's hump”) is a distinctive deflection occurring at the QRS‐ST junction. In 1953, Dr. John Osborn described the “J wave” as an “injury current” resulting in ventricular fibrillation during experimental hypothermia. Although “J Wave” is supposed to be pathognomonic of hypothermia, it is seen in a host of other conditions such as hypercalcemia, brain injury, subarachnoid hemorrhage, cardiopulmonary arrest from over sedation, the Brugada syndrome, vasospastic angina, and idiopathic ventricular fibrillation. However, there is paucity of literature data as regards to ischemic etiology of “J Wave.” In this article, we present a case where “J waves” were probably induced by ischemia. We also discuss the mechanism of ischemia‐induced “J wave” accentuation and its prognostic implications.
Brugada Type Electrocardiographic Changes Induced by Concomitant Use of Lithium and Propafenone in Patient with Wolff–Parkinson–White Syndrome
Authors: FRAGAKIS NIKOLAOS , ILIADIS ILIAS , PAPANASTASIOU SOULTANA , LAMBROU ALEXANDRA , KATSARIS GEORGE
Published: June 2007

We report a case of ST elevation in right precordial leads compatible with type 1 Brugada syndrome following administration of propafenone in a patient with Wolff–Parkinson–White syndrome who was receiving lithium at concentrations within therapeutic levels. The mechanism of the electrocardiogram changes was considered to be caused by the two drugs synergistic sodium channel blocking effects.
Blood Flow Imaging—A New Angle‐Independent Ultrasound Modality for the Visualization of Flow in Atrial Septal Defects in Children
Authors: Nyrnes Siri Ann , Løvstakken Lasse , Torp Hans , Haugen Bjørn Olav
Published: June 2007

Background: Color Doppler imaging (CDI) is the most applied method for evaluation of flow in atrial septal defects (ASD). A new real time ultrasound flow imaging modality called blood flow imaging (BFI) is able to visualize the blood flow in any direction of the image and is not limited by velocity aliasing. The method thereby overcomes the two limitations most often encountered in CDI. In this study we compared BFI with CDI for the visualization of interatrial blood flow in children. Methods: We studied ASD flow in 13 children using both CDI and BFI in the same examination. CDI and BFI cineloops were prepared off‐line and both optimal and suboptimal (increased color artifacts) images were presented in random order to four observers. They were asked to range from 0–100 on a visual analogue scale how certain they were of interatrial blood flow. The CDI and BFI ratings were compared using the exact Wilcoxon signed rank test for paired samples. Results: All ASDs visualized with CDI were confirmed using BFI. Two of the observers ranked BFI as being significantly better than CDI when the images were optimized. When the images were suboptimal three of the observers rated BFI as being significantly better. Conclusions: This pilot study indicates that BFI improves the visualization of interatrial blood flow in children. To include BFI in the ordinary echocardiography examination is easy and not time consuming. The method may prove to be a useful supplement to CDI in ASD imaging.
Influence of CuO on the Structure and Piezoelectric Properties of the Alkaline Niobate‐Based Lead‐Free Ceramics
Authors: Li Enzhu , Kakemoto Hirofumi , Wada Satoshi , Tsurumi Takaaki
Published: June 2007

Recently, it was reported that the alkaline niobate‐based (K,Na,Li)(Nb,Ta,Sb)O3 (LF4) perovskite ceramics showed excellent piezoelectric properties and have been regarded as a new candidate of lead‐free piezoelectric materials. However, the effects of additives on the piezoelectric property of LF4 have not been studied intensively so far. In this study, the effect of CuO addition to the LF4 was investigated. The sample showed a tetragonal phase at room temperature and also a second phase with low melt point. With 0.05 wt% CuO added, the Cu2+ firstly incorporated into the A site, while higher amounts of Cu2+ substituted B‐site ions. The CuO‐doping changed the LF4 to “hard” piezoelectric ceramics with improvement of mechanical quality factor from 26 to 137 but the piezoelectric d31 constant and the electromechanical coupling constant reduced drastically at the same time.
Thermodynamic Stability of Gadolinia‐Doped Ceria Thin Film Electrolytes for Micro‐Solid Oxide Fuel Cells
Authors: Rupp Jennifer L.M. , Infortuna Anna , Gauckler Ludwig J.
Published: June 2007

Next‐generation micro‐solid oxide fuel cells for portable devices require nanocrystalline thin‐film electrolytes in order to allow fuel cell fabrication on chips at a low operation temperature and with high power outputs. In this study, nanocrystalline gadolinia‐doped ceria (Ce0.8Gd0.2O1.9−x) thin‐film electrolytes are fabricated and their electrical conductivity and thermodynamic stability are evaluated with respect to microstructure. Nanocrystalline gadolinia‐doped ceria thin‐film material (Ce0.8Gd0.2O1.9−x) exhibits a larger amount of defects due to strain in the film than state‐of‐the‐art microcrystalline bulk material. This strain in the film decreases the ionic conductivity of this ionic O2− conductor. The thermodynamic stability of a nanocrystalline ceria solid solution with 65 nm grain size is reduced compared with microcrystalline material with 3–5 μm grain size. Nanocrystalline spray‐pyrolyzed and PLD Ce0.8Gd0.2O1.9−x thin films with average grain sizes larger than 70 nm show predominantly ionic conductivity for temperatures lower than 700°C, which is high enough to be potentially used as electrolytes in low to intermediate‐temperature micro‐solid oxide fuel cells.
Novel Design of Microchanneled Tubular Solid Oxide Fuel Cells and Synthesis Using a Multipass Extrusion Process
Authors: Lee Byong‐Taek , Esfakur Rahman A. H. M. , Kim Jong‐Hee
Published: June 2007

A novel, microchanneled tubular solid oxide fuel cell was fabricated using a multipass extrusion process, with an outside diameter of 2.7 mm that contained 61 cells. Cell materials used in this work were 8 mol% yttria‐stabilized zirconia (8YSZ), La0.8Sr0.2MnO3 (LSM), and NiO–8YSZ (50:50 vol%) as electrolyte, cathode, and anode, respectively. Three stages of heat‐treatment processes were applied, at 700°C in N2 condition, at 1000°C in air, and then sintered at 1300°C for 2 h, respectively. The X‐ray diffraction analysis confirmed that no reaction phases appeared after sintering. The microstructures of anode and cathode were fairly porous while the electrolyte had a dense microstructure (relative density >96%). The thickness of electrolyte, anode, and cathode were 20, 30, and 40 μm, respectively, and the diameter of the continuous channels was 150 μm.
In situ TEM Investigations of the High‐Temperature Relaxor Ferroelectric BiScO3–Pb(Mg1/3Nb2/3)O3–PbTiO3 Ternary Solid Solution
Authors: Stringer Craig J. , Randall Clive A.
Published: June 2007

Compositions near the morphotropic phase boundary (MPB) of the BiScO3–Pb(Mg1/3Nb2/3)O3–PbTiO3 ternary system showed high‐temperature relaxor properties (1 kHz) of Tmax∼250°C and a permittivity maximum of ∼16 000. Transmission electron microscopy (TEM) was used to investigate the nature of the microstructure under ambient conditions and with in situ heating studies for samples with different composition and electric field‐temperature histories. A mottled domain structure was observed with diffraction contrast TEM techniques and associated with frozen in polar micro‐domains. These observations are consistent with the low field permittivity temperature measurements made under various frequencies (100 Hz–100 kHz) with a freezing temperature, Tf∼160°C. Field‐cooled (FC) samples exhibited a macro‐domain structure similar to normal ferroelectric behavior. On heating the FC samples to approximately the Tmax and above, the domain contrast was no longer apparent. When subsequently cooled to room temperature conditions, a micro‐domain structure was observed, similar to the zero FC samples. The results are discussed with respect to permittivity measurements and phenomenological mechanisms contributing to the dispersion in the permittivity below the Curie maximum.
Nano α‐Al2O3 Powder Preparation by Calcining an Emulsion Precursor
Authors: Lee Yu‐Chen , Wen Shaw‐Bing , Wenglin Liang , Lin Chih‐Peng
Published: June 2007

An experimental study has been conducted to evaluate the formation of nano α‐Al2O3 under various conditions, such as different calcining temperatures and emulsion ratios of aqueous aluminum nitrate solutions and oleic acid with a high‐speed stirring mixer. Four batches of the precursor powders were calcined at three different temperatures of 1000°, 1050°, and 1100°C for 2 h and a terminal product of nano α‐Al2O3 powders was obtained. The products have been identified by X‐ray diffraction (XRD), specific surface area measurement scanning electron microscope, and transmission electron microscope (TEM). The XRD results show that the phase of powders is determined to be α‐Al2O3, indicating that the overall process has been effective. The optimum calcination temperature of the precursor powder for crystallization of nano α‐Al2O3 was found to be 1000°C for 2 h. The TEM image indicates that the particle grains have a sub‐spherical shape with a mean size of 50–100 nm.
Dynamic Indentation Response of Fine‐Grained Boron Carbide
Authors: Ghosh Dipankar , Subhash Ghatu , Sudarshan Tirumalai S. , Radhakrishnan Ramachandran , Gao Xin‐Lin
Published: June 2007

Boron carbide disks with three different grain sizes were consolidated from submicrometer‐sized boron carbide powder using the plasma pressure compaction technique. Static and dynamic indentations were performed to determine their loading‐rate dependence on mechanical properties. Dynamic indentations resulted in a decrease in hardness and fracture toughness, and induced more severe damage compared with static indentations. Using Raman spectroscopy, the mechanism responsible for loss of strength under dynamic loads was identified as the solid‐state structural phase transformation in the dynamically loaded regions. The influence of processing conditions and the resulting microstructure on the observed rate dependency of mechanical properties are discussed.
Effects of Mg/Si Ratio on Microwave Dielectric Characteristics of Forsterite Ceramics
Authors: Song K. X. , Chen X. M. , Fan X. C.
Published: June 2007

Nonstoichiometric Mg2SiO4forsterite dielectric ceramics with various Mg/Si ratios (R=2.025, 2.05, and 2.2) were prepared and characterized. The appearance of a MgSiO3secondary phase could be effectively suppressed by adjusting the nonstoichiometry, and a single‐phase forsterite structure was obtained in the present ceramics with Mg/Si ratios of 2.025 and 2.05. The microwave dielectric characteristics were significantly improved in the nonstoichiometric Mg2SiO4ceramics on eliminating the MgSiO3secondary phase, where an enhancedQ×fvalue and a suppressed temperature coefficient of resonant frequency λfwere obtained. The best microwave characteristics were achieved in the nonstoichiometric forsterite ceramics with an Mg/Si ratio of 2.05: ɛr=7.5,Q×f=114 730 GHz, and λf=−59 ppm/°C.
(Na0.8K0.2)0.5Bi0.5TiO3 Nanowires: Low‐Temperature Sol–Gel–Hydrothermal Synthesis and Densification
Authors: Hou Yu‐Dong , Hou Lei , Zhang Ting‐Ting , Zhu Man‐Kang , Wang Hao , Yan Hui
Published: June 2007

The sol–gel–hydrothermal processing of (Na0.8K0.2)0.5Bi0.5TiO3 (NKBT) nanowires as well as their densification behavior were investigated. The morphology and structure analyses indicated that the sol–gel–hydrothermal route led to the formation of phase‐pure perovskite NKBT nanowires with diameters of 50–80 nm and lengths of 1.5–2 μm, and the processing temperature was as low as 160°C, but the conventional sol–gel route tended to lead to the formation of NKBT agglomerated porous structured nanopowders, and the processing temperature was higher than 650°C. It is believed that the gel precursor and hydrothermal environment play an important role in the formation of the nanowires at a low temperature. Owing to the better packing efficiency and therefore a good sinterability of the freestanding nanowhiskers, the pressed pellets made by NKBT nanowires showed >98% theoretical density at 1100°C for 2 h. The sol–gel–hydrothermal‐derived ceramics have typical characteristics of relaxor ferroelectrics, and the piezoelectric properties were better than the ceramics prepared by the conventional sol–gel and solid‐state reaction.
Hypotony maculopathy
Authors: Costa Vital Paulino , Arcieri Enyr Saran
Published: June 2007

Hypotony maculopathy, first described in 1954 by Dellaporta, usually occurs after antiglaucomatous surgery or after perforating eye injuries; it is characterized by hypotony associated with fundus abnormalities, including papilloedema, vascular tortuosity and chorioretinal folds. In hypotony maculopathy, the scleral wall collapses inward, resulting in redundancy of the choroid and retina, leading to chorioretinal wrinkling. As the antero‐posterior diameter of the vitreous cavity decreases, the very thick perivofeal retina surrounding the very thin foveal retina is thrown into radial folds around the fovea. It has been reported that hypotony maculopathy occurs in up to 20% of cases of glaucoma filtering surgery and has become more common after the introduction of antimetabolites. Young age, myopia, primary filtering surgery, systemic illnesses and elevated preoperative intraocular pressure (IOP) have been found to be associated with hypotony maculopathy. Hypotony maculopathy is treated with procedures designed to elevate IOP, which may reverse the inward scleral bowing and improve visual acuity. The successful treatment of hypotony maculopathy depends on the correct identification of its cause. Once the cause is detected, treatment should be employed as soon as possible because delayed normalization of the IOP may result in permanent macular chorioretinal changes and poor vision. This review will explore the definition, mechanisms, clinical findings and treatment of hypotony maculopathy.
Melatonin mediates photoperiod control of endocrine adaptations and humoral immunity in male Siberian hamsters
Authors: Yellon Steven M.
Published: June 2007

Abstract:  Effects of photoperiod are mediated by the pineal gland in male Siberian hamsters. The hypothesis that the pineal hormone melatonin mediates the effects of short days (SD) to blunt select humoral and endocrine functions was tested. In the first study, regressed testes were found in pineal‐intact controls transferred from long days (LD) to SDs (16 hr to 8 hr light/day); the rise in antigen‐induced serum immunoglobulin (Ig) M was blunted and serum cortisol concentrations elevated compared with long‐day controls. These effects of short‐day were blocked in pinealectomized males moved from long to SDs, but restored by melatonin treatments. In a second study, males in LD were exposed to constant light (LL) to abolish the nighttime melatonin rhythm. In hamsters in LL, melatonin induced testicular regression as in males in SDs. Large testes were present in vehicle‐treated controls in LL and in males that remained in LDs. Antigen‐induced increases in serum IgM in vehicle and melatonin treatment males in LL were intermediate between concentrations in long‐ or short‐day controls and not significantly different from each other. However, serum cortisol was again elevated in hamsters in SDs or in LL when treated with melatonin compared with males in LL or LDs. These findings indicate that melatonin treatments mimicked the effects of SDs to regulate adaptive physiologic functions in hamsters lacking the nocturnal melatonin rhythm. Thus, the photoneuroendocrine mechanism regulating reproductive responses to photoperiod also mediates short‐day effects on T cell‐dependent B‐cell antibody production and processes that regulate cortisol in circulation.
Expression of the melatonin receptor (MT) 1 in benign and malignant human bone tumors
Authors: Toma Cyril D. , Svoboda Martin , Arrich Ferdi , Ekmekcioglu Cem , Assadian Ojan , Thalhammer Theresia
Published: June 2007

Abstract:  The beneficial effects of melatonin on bone homeostasis have been shown in various diseases. As this indoleamine causes dose‐dependent modulation of bone‐forming osteoblast and bone‐resorbing osteoclast activities by receptor‐independent and ‐dependent pathways, we investigated the expression of G‐protein‐coupled melatonin receptors (MTs) in malignant and non‐malignant human bone lesions. By TaqMan polymerase chain reaction (PCR), we analyzed 30 specimens from osteosarcoma and 11 from benign bone tumors for MT1‐mRNA expression. Furthermore, we determined mRNA expression levels of the osteoclast activity‐stimulating receptor activator of nuclear factor‐κ B ligand (RANKL) and its counterpart osteoprotegerin (OPG). Although mean MT1‐mRNA levels were similar (P = 0.596) in malignant (4.39 ± 4.98‐fold) and benign samples (4.64 ± 6.81‐fold), the highest MT1‐mRNA levels (up to 27‐fold) were observed in individual osteosarcomas, particularly, in two specimens of patients with local recurrence of the tumor. Moreover, mean RANKL‐ and OPG‐mRNA levels were similar in malignant and benign specimens (RANKL: 7.38 ± 9.61‐fold versus 3.57 ± 3.11‐fold, P = 0.207; OPG: 23.45 ± 32.76 versus 8.07 ± 7.23‐fold, P = 0.133). Again, highest RANKL‐ and OPG‐mRNA levels (up to 41‐ and 160‐fold, respectively) were observed in individual osteosarcomas. Expression of MT1‐mRNA was confirmed in two human osteosarcoma cell lines (HOS, MG63). High expression levels of MT1‐mRNA together with low OPG‐mRNA were found in both osteosarcoma cell lines, while in normal human osteoblasts and bone marrow stromal cells, high OPG‐mRNA levels were associated with low MT1‐mRNA levels. These data on the abundant expression of MT1‐mRNA in human bone tumors and osteosarcoma cells lines suggest an important role for MT1 in bone pathology.
Melatonin inhibits oxidative stress and apoptosis in fetal brains of hyperhomocysteinemic rat dams
Authors: Baydas Giyasettin , Koz Sema T. , Tuzcu Mehmet , Etem Ebru , Nedzvetsky Viktor S.
Published: June 2007

Abstract  Moderate hyperhomocysteinemia is a risk factor for neurodegenerative diseases and complications during pregnancy. Increased homocysteine levels during pregnancy may elevate developmental risk on fetal brain structure and function. However, little is known about the mechanism of action of homocysteine on the degeneration of the fetal brain. Hence in this study, we examined the effects of maternal hyperhomocysteinemia on oxidative stress and apoptosis in brain tissues and investigated whether administration of melatonin to the mother would prevent homocysteine‐induced oxidative cerebral damage in pups. Hyperhomocysteinemia was induced in female rats by administration of methionine at a dose of 1 g/kg body weight dissolved in drinking water during pregnancy. Some animals received methionine plus 10 mg/kg/day melatonin subcutaneously throughout pregnancy. After delivery, the level of lipid peroxidation (malondialdehyde + 4‐hydroxyalkenals) was determined in different subfractions of pup brains. Furthermore, DNA fragmentation, levels of Bcl‐2 protein and p53 mRNA expression were determined to evaluate apoptosis. Significant elevation was found in the levels of lipid peroxidation in subcellular fractions of the brain of pups of hyperhomocysteinemic dams. Increased DNA fragmentation and p53 mRNA expression was observed in the brain of pups of homocysteine‐treated rats, while a significant reduction was seen in the levels of anti‐apoptotic Bcl‐2 levels. Melatonin administration prevented markers of oxidative stress and biochemical signs of apoptosis. In conclusion, therapeutic administration of melatonin protects against the induction of oxidative stress and neural tissue injury and might prevent congenital malformations of fetal brain caused by maternal hyperhomocysteinemia.