Percutaneous repair of post-myocardial infarction ventricular septal defect: current approaches and future perspectives.

Post-myocardial infarction ventricular septal defect is a devastating complication of ST-elevation myocardial infarction. Although surgical intervention is considered the gold standard for treatment, it carries high morbidity and mortality rates. We present 2 cases that illustrate the application of percutaneous closure of a post-myocardial infarction ventricular septal defect: the first in a patient who had undergone prior surgical closure and then developed a new shunt, and the second as a bridge to definitive surgery in a critically ill patient.

Where have all the antibiotic patents gone?

Patent and regulatory hurdles combined with low returns on investment are stifling antibiotic R&D in the pharmaceutical industry.

Ultrasound-guided laser-induced thermal therapy of malignant cervical adenopathy.

OBJECTIVES: Laser-induced thermal therapy (LITT) for cancer is a technique whereby a source of energy (laser, radiofrequency, ultrasonic, cryoenergy, and so on) is directly applied into a tumor at various depths. Recent studies have demonstrated the efficiency of ultrasound (UTZ) and magnetic resonance imaging (MRI) for real- or "near" real-time tumor and vessel identification as well as monitoring and quantifying energy-induced tissue damage. The objective of this study is to report UCLA's experience using UTZ monitoring of Nd:YAG laser thermal ablation of malignant cervical adenopathy in a phase II study. STUDY DESIGN: The authors conducted a retrospective study of patients treated at a tertiary medical center. METHODS: Forty-seven patients with a total of 55 neck tumors were treated on an outpatient basis in the operating room using UTZ for image-guided laser interstitial thermal therapy. Laser energy was delivered through an SLT Nd:YAG laser powered at 30 W (power density: 2,200 J/cm). RESULTS: Eleven patients had a complete response ranging from 5.5 to 90 months (mean, 22.1 months). Based on the findings of this study, it was possible to show that proximity to the carotid artery was the most relevant factor in projecting patient survival. Patients' individual treatment analysis and final outcome are further discussed. CONCLUSIONS: LITT ablation of malignant cervical adenopathy was considered safe and feasible. No intraoperative complications occurred. Further development of this technique applying laser energy delivery to mathematical imaging models should lead to more effective tumor palliation as an alternative to surgery.

Myosin II dynamics in Dictyostelium: determinants for filament assembly and translocation to the cell cortex during chemoattractant responses.

In the simple amoeba Dictyostelium discoideum, myosin II filament assembly is regulated primarily by the action of a set of myosin heavy chain (MHC) kinases and by MHC phosphatase activity. Chemoattractant signals acting via G-protein coupled receptors lead to rapid recruitment of myosin II to the cell cortex, but the structural determinants on myosin necessary for translocation and the second messengers upstream of MHC kinases and phosphatases are not well understood. We report here the use of GFP-myosin II fusions to characterize the domains necessary for myosin II filament assembly and cytoskeletal recruitment during responses to global stimulation with the developmental chemoattractant cAMP. Analysis performed with GFP-myosin fusions, and with latrunculin A-treated cells, demonstrated that F-actin binding via the myosin motor domain together with concomitant filament assembly mediates the rapid cortical translocation observed in response to chemoattractant stimulation. A "headless" GFP-myosin construct lacking the motor domain was unable to translocate to the cell cortex in response to chemoattractant stimulation, suggesting that myosin motor-based motility may drive translocation. This lack of localization contrasts with previous work demonstrating accumulation of the same construct in the cleavage furrow of dividing cells, suggesting that recruitment signals and interactions during cytokinesis differ from those during chemoattractant responses. Evaluating upstream signaling, we find that iplA null mutants, devoid of regulated calcium fluxes during chemoattractant stimulation, display full normal chemoattractant-stimulated myosin assembly and translocation. These results indicate that calcium transients are not necessary for chemoattractant-regulated myosin II filament assembly and translocation.