When Too Many Hits Break the Heart: A Case of Radiation Induced Takotsubo Cardiomyopathy.

Takotsubo cardiomyopathy (TCM), or stress induced cardiomyopathy is being increasingly recognized as a cause of acute heart failure. Often seen in women and older individuals with acute stressors, it can cause significant hemodynamic compromise. Here we report a case of a 78 year old woman who developed sudden chest pain following radiation therapy for B-Cell lymphoma. Echocardiogram revealed newly reduced ejection fraction and cardiac catheterization showed non obstructive coronary disease. Left ventriculogram revealed apical ballooning, characteristic of TCM. Often linked to physical and emotional stressors, TCM has been found to be more prevalent in patients with malignancies.

Design and development of high power RF amplifier for 88 in. room temperature cyclotron at Variable Energy Cyclotron Centre (VECC), Kolkata.

A tetrode based high power radio frequency (RF) amplifier has been designed, developed, and commissioned at Variable Energy Cyclotron Centre, Kolkata, India, for the 88-in. room temperature K130 cyclotron. The amplifier feeds power to a RF cavity based on the quarter-wave cantilever-type resonating structure to develop a high accelerating voltage for particle acceleration. The initial design of this amplifier was based on tetrode tube, which has already become obsolete. A new design of the RF amplifier has been made with a different tetrode of much lower power to satisfy the requirement of the cyclotron. This paper gives detailed insight into the various issues of the tetrode amplifier design and operational experience for the K130 cyclotron RF system.

Precision phase control for the radio frequency system of K500 superconducting cyclotron at Variable Energy Cyclotron Centre, Kolkata.

Variable Energy Cyclotron Centre (VECC) has commissioned K500 Superconducting cyclotron (SCC) based on MSU and Texas A&M university cyclotrons. The radio frequency (RF) system of SCC has been commissioned with the stringent requirement of various RF parameters. The three-phase RF system of Superconducting cyclotron has been developed in the frequency range 9-27 MHz with amplitude and phase stability of 100 ppm and ±0.1°, respectively. The phase control system has the option to change the relative phase difference between any two RF cavities and maintain the phase stability within ±0.1° during round-the-clock cyclotron operation. The said precision phase loop consists of both analogue In-phase∕Quadrature modulator to achieve faster response and also Direct Digital Synthesis based phase shifter to achieve wide dynamic range as well. This paper discusses detail insights into the various issues of phase control for the K500 SCC at VECC, Kolkata.

Radio frequency cavity analysis, measurement, and calibration of absolute Dee voltage for K-500 superconducting cyclotron at VECC, Kolkata.

Variable Energy Cyclotron Centre has commissioned a K-500 superconducting cyclotron for various types of nuclear physics experiments. The 3-phase radio-frequency system of superconducting cyclotron has been developed in the frequency range 9-27 MHz with amplitude and phase stability of 100 ppm and ±0.2(0), respectively. The analysis of the RF cavity has been carried out using 3D Computer Simulation Technology (CST) Microwave Studio code and various RF parameters and accelerating voltages ("Dee" voltage) are calculated from simulation. During the RF system commissioning, measurement of different RF parameters has been done and absolute Dee voltage has been calibrated using a CdTe X-ray detector along with its accessories and known X-ray source. The present paper discusses about the measured data and the simulation result.

Decreasing frequency of plasma exchange complications in patients treated for thrombotic thrombocytopenic purpura-hemolytic uremic syndrome, 1996 to 2011.

BACKGROUND: Plasma exchange (PEX) treatment for patients with thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS) has risk for major complications. STUDY DESIGN AND METHODS: Data for PEX-related complications have been prospectively collected on all patients enrolled in the Oklahoma TTP-HUS Registry, 1996 to 2011. PEX-related complications have been defined as major or minor and as central venous catheter related or plasma related. RESULTS: During 15 years, 1996 to 2011, 72 (24%) of 302 consecutive patients had major PEX-related complications. Analysis of five consecutive 3-year cohorts demonstrated that there has been a significant trend for decreasing frequency of all PEX-related major complications (p = 0.014) and central venous catheter-related major complications (p = 0.021) but not for the less common plasma-related major complications (p = 0.380). ADAMTS13 activity was measured in 288 (95%) of the 302 patients. Analysis of the 66 patients with ADAMTS13 activity of less than 10% demonstrated a significant trend for decreasing frequency of PEX-related major complications (p = 0.036); the trend for the 222 patients with ADAMTS13 activity of at least 10% was not significant (p = 0.118). The decreased frequency of PEX-related major complications among patients with ADAMTS13 activity of less than 10% may be related to a significant trend for decreasing duration of PEX treatment (p = 0.040) and decreasing frequency of requirement for more than one central venous catheter (p = 0.044). The decreased duration of PEX treatment may be related to increased use of adjunctive treatments: corticosteroids (p < 0.001) and rituximab (p < 0.001). CONCLUSIONS: The frequency of PEX-related major complications has decreased from 1996 to 2011, possibly related to increased use of corticosteroids and rituximab and the decreased duration of PEX required to achieve remission.

Spontaneous recanalization of complete internal carotid artery: a clinical reminder.

Spontaneous recanalization of atherothrombotic extracranial cerebral arteries is rare vis-à-vis recanalization of intracranial vessels. The time course is unknown. The question is the advisability and timing of surgery in a recanalized vessel. We describe a patient with spontaneous recanalization of a totally occluded left Internal Carotid Artery (ICA) who was monitored with periodic imaging and in time had partial recanalization of the ICA. We believe patients with total ICA occlusion with return of function should be followed up with periodic carotid ultrasound, Magnetic Resonance Angiography (MRA) or CT angiography, and when appropriate, be candidates for carotid vascular interventions.

Doxylamine toxicity: seizure, rhabdomyolysis and false positive urine drug screen for methadone.

The present report highlights the possible adverse effects of doxylamine, a common over the counter sleep aid. Doxylamine is an antihistamine that at toxic doses can cause anticholinergic effects, including seizures, rhabdomyolysis and death. The following case describes a patient with doxylamine toxicity who presented with seizure and confusion. Our patient was managed symptomatically, and remained otherwise stable throughout his hospitalisation. This case is atypical in terms of a delayed rhabdomyolysis and a false positive urine drug screen test for methadone. There is evidence that doxylamine at toxic levels can lead to false positives for methadone and phencyclidine testing using immunoassay-based urine drug screen kits. Urine drug screen testing on patients who are hospitalised is typically performed using immunoassays. However, in certain cases confirmatory secondary testing may be required. Doxylamine is prone to abuse and knowledge of the clinical presentation of its toxicity and the management of acute overdose can be life-saving.