Proarrhythmia.

Proarrhythmia is defined as the aggravation of an existing arrhythmia or the development of a new arrhythmia secondary to antiarrhythmic drug. Proarrhythmic events include drug-induced bradyarrhythmias, atrial and ventricular proarrhythmias. New onset sustained or incessant ventricular tachycardia and torsade de pointes can be life threatening.

Comparison of vignettes, standardized patients, and chart abstraction: a prospective validation study of 3 methods for measuring quality.

Context: Better health care quality is a universal goal, yet measuring quality has proven to be difficult and problematic. A central problem has been isolating physician practices from other effects of the health care system.

Objective: To validate clinical vignettes as a method for measuring the competence of physicians and the quality of their actual practice.

Measuring compliance with preventive care guidelines: standardized patients, clinical vignettes, and the medical record.

Objective: To determine how accurately preventive care reported in the medical record reflects actual physician practice or competence.

Design: Scoring criteria based on national guidelines were developed for 7 separate items of preventive care. The preventive care provided by randomly selected physicians was measured prospectively for each of the 7 items.

Using standardized patients to measure quality: evidence from the literature and a prospective study.

Background: Use of standardized patients for evaluating the clinical skills of medical students and medical trainees is commonplace. This has encouraged the use of standardized patients to evaluate the quality of physician practice in outpatient settings. However, there may be substantive differences between observing student performance and evaluating whether the provision of care meets defined quality criteria.

Interstitial hydraulic conductivity in a fibrosarcoma.

Convective transport of therapeutic agents in solid tumors can be improved through intratumoral infusion. To optimize the convection, we investigated the dependence of the hydraulic conductivity on tissue deformation induced by interstitial fluid pressure gradient during the infusion. Two experimental systems were used in the investigation: 1) one-dimensional perfusion through tumor slices and 2) intratumoral infusion using a needle.

Homeobox B3, B4, and C6 gene product expression in osteosarcomas as detected by immunocytochemistry.

Osteosarcoma (OS) is a malignant neoplastic disease of the bone, of mesenchymal origin and with considerable morphologic heterogeneity, consisting of malignant stoma with evidence of malignant osteoid, bone and/or cartilage production. The mammalian homeobox (HOX) represents a highly conserved DNA motif of 183 base pairs, encoding the 61 amino acid DNA-binding homeodomain, through which the HOX gene products regulate the transcription of other genes involved in onto- and histogenesis. Re-expression of HOX proteins has been identified in a wide variety of neoplastically transformed cell types and it seems that the HOX genes represent yet another family of oncofetal antigens involved in both normal development and oncogenesis, as well as tumor tissue progression.

Regions outside of the leucine-rich repeats of flax rust resistance proteins play a role in specificity determination.

Multiple alleles controlling different gene-for-gene flax rust resistance specificities occur at the L locus of flax. At least three distinct regions can be recognized in the predicted protein products: the Toll/interleukin-1 receptor homology (TIR) region, a nucleotide binding site (NBS) region, and a leucine-rich repeat (LRR) region. Replacement of the TIR-encoding region of the L6 allele with the corresponding regions of L2 or LH by recombination changed the specificity of the allele from L6 to L7.

How well does chart abstraction measure quality? A prospective comparison of standardized patients with the medical record.

Purpose: Despite widespread reliance on chart abstraction for quality measurement, concerns persist about its reliability and validity. We prospectively evaluated the validity of chart abstraction by directly comparing it with the gold standard of reports by standardized patients.

Subjects And Methods: Twenty randomly selected general internal medicine residents and attending faculty physicians at the primary care clinics of two Veterans Affairs Medical Centers blindly evaluated and treated actor-patients (standardized patients) who had one of four common diseases: diabetes, chronic obstructive pulmonary disease, coronary artery disease, or low back pain.

Cost-effective management of acute atrial fibrillation: role of rate control, spontaneous conversion, medical and direct current cardioversion, transesophageal echocardiography, and antiembolic therapy.

Management strategies for the acute treatment of atrial fibrillation (AF) include: (1) the use of intravenous drugs for rate control, (2) drug termination, or (3) direct current (DC) cardioversion. Delays in cardioversion can promote atrial remodeling and add thromboembolic risk. Rate control awaiting spontaneous or pharmacologic conversion may be a cost-effective strategy in patients presenting with recent onset of symptoms.

Improving the public sector: can reengineering identify how to boost efficiency and effectiveness at a VA medical center?

Reengineering is a widespread management technique, but few evaluations of its application in health care, especially in public sector organizations, have been reported. We conducted a reengineering analysis to determine if the method could identify how to improve the efficiency and effectiveness of a VA medical center's primary care delivery system. We found that the reengineering method appears applicable in the institutional context of a public sector teaching hospital.

Full angular profile of the coherent polarization opposition effect.

We use the rigorous vector theory of weak photon localization for a semi-infinite medium composed of nonabsorbing Rayleigh scatterers to compute the full angular profile of the polarization opposition effect. The effect is caused by coherent backscattering of unpolarized incident light and accompanies the well-known backscattering intensity peak.

Amiodarone: what have we learned from clinical trials?

Amiodarone is an antiarrhythmic agent commonly used in the treatment of supraventricular and ventricular tachyarrhythmias. This paper reviews clinical trials in which amiodarone was used in one of the treatment arms. Key post-myocardial infarction trials include EMIAT and CAMIAT, both of which demonstrated that amiodarone reduced arrhythmic but not overall mortality.

Amiodarone: clinical trials.

Amiodarone is an antiarrhythmic agent commonly used in the treatment of supraventricular and ventricular tachyarrhythmias. This article reviews the results and clinical implications of primary and secondary prevention trials in which amiodarone was used in one of the treatment arms. Key post-myocardial infarction primary prevention trials include the European Myocardial Infarct Amiodarone Trial (EMIAT) and the Canadian Amiodarone Myocardial Infarction Trial (CAMIAT), both of which demonstrated that amiodarone reduced arrhythmic but not overall mortality.

A randomized controlled trial of intracameral lidocaine during phacoemulsification under topical anesthesia.

Objective: To test the hypothesis that adjunctive intracameral 1% lidocaine reduces intraoperative pain during phacoemulsification using topical anesthesia.

Design: Prospective, double-masked, randomized, controlled trial.

Participants: A total of 200 patients undergoing routine phacoemulsification under topical 1% tetracaine were studied.

Magnesium deficiency-induced osteoporosis in the rat: uncoupling of bone formation and bone resorption.

Magnesium (Mg) intake has been linked to bone mass and/or rate of bone loss in humans. Experimental Mg deficiency in animal models has resulted in impaired bone growth, osteopenia, and increased skeletal fragility. In order to assess changes in bone and mineral homeostasis that may be responsible, we induced dietary Mg deficiency in adult Simonsen albino rats for 16 weeks.

Acute treatment of atrial fibrillation: spontaneous conversion rates and cost of care.

Acute treatment of atrial fibrillation is costly although spontaneous conversion rates are high. We reviewed 114 patients admitted to our inpatient service via the emergency department with a principal diagnosis of atrial fibrillation and found the spontaneous conversion rate was 50% in 48 hours, the average length of stay was 3.9 +/- 5.

Identification of regions in alleles of the flax rust resistance gene L that determine differences in gene-for-gene specificity.

Thirteen alleles (L, L1 to L11, and LH) from the flax L locus, which encode Toll/interleukin-1 receptor homology-nucleotide binding site-leucine-rich repeat (TIR-NBS-LRR) rust resistance proteins, were sequenced and compared to provide insight into their evolution and into the determinants of gene-for-gene resistance specificity. The predicted L6 and L11 proteins differ solely in the LRR region, whereas L6 and L7 differ solely in the TIR region. Thus, specificity differences between alleles can be determined by both the LRR and TIR regions.

Benign and malignant cartilage tumors of bone and joint: their anatomic and theoretical basis with an emphasis on radiology, pathology and clinical biology. II. Juxtacortical cartilage tumors.

In part I, we reviewed the varied clinical presentations, pathogenesis, histologic findings, radiologic findings, and treatment of intramedullary cartilaginous lesions of bone. In this section, we will evaluate our cases and consultations of juxtacortical cartilaginous tumors. Radiographic differential diagnosis includes the numerous juxtacortical lesions particularly osteochondroma, parosteal chondroma, Trevor's disease, trauma (fracture and periostitis ossificans), and the low- and high-grade surface osteosarcomas.

A flax transposon identified in two spontaneous mutant alleles of the L6 rust resistance gene.

Two spontaneous mutant alleles of the L6 flax rust resistance gene, 16-X3A and 16-X117, contain the same transposable element designated dLute (defective Linum usitatissimum transposable element). The element is 314 bp long, 70% AT-rich and, because it contains no extended open reading frame, is probably non-autonomous. It has 14 bp imperfect terminal inverted repeats related to those in the Ac family of plant transposons and, like Ac, causes 8 bp target site duplications upon insertion.

Hemopoietic stem-cell harvesting and transplantation using G-CSF-primed BM: comparison with unprimed BM and G-CSF-primed PBSC.

Background: PBSC collected following G-CSF priming lead to more rapid hemopoietic reconstitution (HR) after autologous transplantation than do unprimed BMstem cells. However, PBSC have a number of disadvantages compared with BM cells, including the need for an extended collection period and requirement for good venous access.

Methods: We retrospectively analysed our experience with an alternative source of hemopoietic stem cells, G-CSF primed BM.

Early induced astigmatism following phacoemulsification and flexible lens implantation through an oblique corneal tunnel.

Purpose: To analyse the early surgically induced corneal astigmatism (SICA) with a 3.5 mm oblique clear corneal incision (CCI) for phacoemulsification and flexible silicone implant.

Methods: Sixty-four consecutive patients were included in this study.

How far down the managed care road? A comparison of primary care outpatient services in a Veterans Affairs medical center and a capitated multispecialty group practice.

Background: Under increasing pressure to provide more efficient, higher-quality care, the Department of Veterans Affairs (VA) is expanding primary care and implementing other managed care techniques. To assess the magnitude of performance improvement possible in the VA and to investigate potential barriers to implementation of new techniques, we compared a VA facility with similar managed care organizations on specific managed care performance benchmarks. METHODS AND DATA COLLECTION: Detailed case studies of a large VA medical center and a large capitated multispecialty group practice in the same region were carried out.