Novel robotic catheter remote control system: feasibility and safety of transseptal puncture and endocardial catheter navigation

Objectives: The aims of this study were to demonstrate the safety and the feasibility of the robotic catheter remote control system (CCS) in endocardial navigation in all cardiac chambers, as well as facilitation of the transseptal puncture.
Background: CCS has been developed to facilitate control and precise positioning of catheters within the cardiovascular system.
Methods: CCS consists of a remote catheter manipulator, a set up joint, a physician workstation, and a steerable guide catheter (SGC) and sheath. A conventional 4-mm tip catheter was inserted through the SGC to perform mapping of five predefined targets in each cardiac chamber. Seven mongrel dogs were used in this study. Intracardiac echocardiography and three-dimensional (3-D) electroanatomical mapping were integrated with CCS to facilitate catheter manipulation and to guide transseptal puncture. The time to complete the transseptal puncture and the time to complete access to the predefined targets in each cardiac chamber were measured. Gross and microscopic examinations of the accessed and ablation sites were performed to evaluate safety.
Results: Transseptal puncture was performed successfully in all animals with a mean time of 7 ± 3 minutes. Procedure times to access the five targets in the right atrium, right ventricle, left atrium, and left ventricle were 5.6 ± 1.7, 4.6 ± 1.5, 13.5 ± 11.0, 7.0 ± 2.9 minutes, respectively. There were no intracardiac damages associated with catheter manipulation noted in the excised hearts.
Conclusions: Endocardial catheter navigation and mapping using the robotic catheter remote control is safe and feasible. Moreover, the CCS could be used to perform transseptal puncture and left atrial instrumentation.     

In vitro generation of novel pyrimethamine resistance mutations in the Toxoplasma gondii dihydrofolate reductase

Pyrimethamine is a potent inhibitor of dihydrofolate reductase and is widely used in the treatment of opportunistic infections caused by the protozoan parasite Toxoplasma gondii. In order to assess the potential role of dhfr sequence polymorphisms in drug treatment failures, we examined the dhfr-ts genes of representative isolates for T. gondii virulence types I, II, and III. These strains exhibit differences in their sensitivities to pyrimethamine but no differences in predicted dhfr-ts protein sequences. To assess the potential for pyrimethamine-resistant dhfr mutants to emerge, three drug-sensitive variants of the T. gondii dhfr-ts gene (the wild-type T. gondii sequence and two mutants engineered to reflect polymorphisms observed in drug-sensitive Plasmodium falciparum) were subjected to random mutagenesis and transfected into either wild-type T. gondii parasites or dhfr-deficient Saccharomyces cerevisiae under pyrimethamine selection. Three resistance mutations were identified, at amino acid residues 25 (Trp-->Arg), 98 (Leu-->Ser), and 134 (Leu-->His).     

Application of power Doppler vocal fremitus sonography in breast lesions.

OBJECTIVE: The purpose of this study was to illustrate the method and use of power Doppler vocal fremitus (PDVF) sonography in the detection and diagnosis of breast lesions. METHODS: One case was evaluated by various sonographic parameters and equipment to determine how the VF images were affected. Cases illustrative of a broad range of breast conditions were also collected. Each image pair consisted of B-mode and VF images to maintain an identical projection and to illustrate the influence of PDVF sonography. RESULTS: With B-mode and PDVF sonography, we evaluated and compared various breast conditions, including normal anatomic structures and abnormal lesions. We found that PDVF sonography is useful for distinguishing abnormal masses from normal tissue, such as differentiating between isoechoic tumors and isoechoic glandular tissues, and discriminating entrapped fat lobules from isoechoic tumors. Furthermore, PDVF sonography was useful for determining whether intracystic echoes are attached to the cyst wall. CONCLUSIONS: Power Doppler VF imaging is a valuable adjunct tool to B-mode sonography in the evaluation of breast lesions.     

Monitoring Therapeutic Response in a Case of Extrapulmonary Tuberculosis by Serial F-18 FDG PET/CT

Due to the low yield of AFB smear and culture in extrapulmonary tuberculosis, therapeutic responses of patients with extrapulmonary tuberculosis are usually monitored clinically and/or radiographically. Such monitoring techniques, however, are not enough to provide effective diagnosis if a remnant lesion exists after treatment. Tuberculosis presents hypermetabolic activity on F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) scanning. Reported herein is a case of extrapulmonary tuberculosis where the therapeutic response was assessed via serial F-18 FDG PET/CT scanning, which was useful for detecting the extent of extrapulmonary tuberculosis and for estimating the patient’s therapeutic response.     

Effectiveness of raloxifene on bone mineral density and serum lipid levels in post-menopausal women with low BMD after discontinuation of hormone replacement therapy

OBJECTIVE: To evaluate the effect of raloxifene on bone mineral density (BMD) and serum lipid levels in post-menopausal women who had discontinued hormone replacement therapy (HRT). METHODS: Thirty-four post-menopausal women with low BMD who had taken 60 mg of raloxifene daily for 12 months after discontinuing HRT were evaluated retrospectively. Information about their demographics, fracture history, BMD, lipid profiles and adverse events were collected from medical records and intranet database. The outcome measures were changes in the spine (L2-L4) and femur BMD, serum lipid concentrations, fracture rate and tolerability. RESULTS: The post-menopausal women had a significant increase in their spine (L2-L4) and femur BMD from their baseline BMD [spine, 2.9 +/- 4.6% (P < 0.001); femur, 3.0 +/- 6.6% (P = 0.01)]. Serum low-density lipoprotein (LDL) cholesterol was significantly reduced by 22.6% below baseline after 12 months (P = 0.007). No fractures were observed during therapy. Raloxifene was well tolerated. The most common adverse event was hot flash, which was generally mild. CONCLUSIONS: Raloxifene increases BMD at important skeletal sites, and lowers LDL cholesterol with tolerable adverse events.