ABSTRACT
Repetitive transcranial magnetic stimulation (rTMS) has been proposed as a treatment for several neuropsychiatric disorders in human beings, but the neurobiological effects of rTMS in dogs have not been investigated to date. A proof of concept study was designed to evaluate the effect of rTMS on cerebral perfusion, measured with single photon emission computed tomography (SPECT), in dogs. An accelerated high frequency (aHF)-rTMS (20Hz) protocol was applied to the canine left frontal cortex. To accurately target this area, eight dogs underwent a 3 Tesla magnetic resonance imaging (MRI) scan before stimulation. The left frontal cortex was subjected to five consecutive aHF-rTMS sessions with a figure-of-eight coil designed for human beings at an intensity of 110% of the motor threshold. The dogs underwent 99mTc-d,1 hexamethylpropylene amine oxime (HMPAO) SPECT scans 1 week prior to and 1day after the stimulations. Perfusion indices (PIs) were determined semi-quantitatively; aHF-rTMS resulted in significantly increased PIs in the left frontal cortex and the subcortical region, whereas no significant differences were noted for the other regions. Behaviour was not influenced by the stimulation sessions. As has been observed in human beings, aHF-rTMS applied to the left frontal cortex alters regional cerebral perfusion in dogs.
Subject(s)
Cerebrovascular Circulation/physiology , Dogs/physiology , Tomography, Emission-Computed, Single-Photon/veterinary , Transcranial Magnetic Stimulation/veterinary , Animals , Perfusion , Proof of Concept Study , Transcranial Magnetic Stimulation/methodsABSTRACT
Using a renormalization group approach, we determine the phase diagram of an extended quasi-one-dimensional electron gas model that includes interchain hopping, nesting deviations, and both intrachain and interchain repulsive interactions. We find a close proximity of spin-density- and charge-density-wave phases and singlet d-wave and triplet f-wave superconducting phases. There is a striking correspondence between our results and recent puzzling experimental findings in the Bechgaard salts, including the coexistence of spin-density-wave and charge-density-wave phases and the possibility of a triplet pairing in the superconducting phase.
ABSTRACT
PURPOSE: To determine the prognostic value of dobutamine-atropine stress echocardiography (DASE). METHODS: We studied 452 consecutive patients at high risk for coronary artery disease, using DASE. They were followed during a mean period of 23 months. RESULTS: There were 9 cardiac deaths and 2 acute myocardial infarctions in the group of patients with positive tests, and there were 2 myocardial infarctions and 1 cardiac death in patients with negative DASE. CONCLUSION: We conclude that DASE reliably identifies patients at high risk for hard cardiac events.
Subject(s)
Anti-Arrhythmia Agents , Atropine , Cardiotonic Agents , Coronary Disease/diagnostic imaging , Dobutamine , Exercise Test , Drug Combinations , Female , Humans , Male , Middle Aged , Prognosis , Risk Factors , UltrasonographyABSTRACT
OBJETIVO - Avaliar o valor prognóstico para eventos cardíacos maiores da ecocardiografia com estresse pela dobutamina associada à atropina (EEDA). MÉTODOS - Estudados 452 pacientes consecutivos, com alto risco para presença de doença arterial coronária, acompanhados por um período médio de 23 meses. RESULTADOS - Houve 9 mortes cardíacas e 2 infartos agudos do miocárdio em pacientes com EEDA positiva e 2 infartos e 1 morte cardíaca em pacientes com EEDA negativa. CONCLUSÄO - A EEDA é capaz de identificar pacientes de alto risco para eventos maiores.
Subject(s)
Humans , Male , Female , Atropine/pharmacology , Coronary Disease/diagnosis , Dobutamine/pharmacology , Echocardiography , Exercise Test , Acute Disease , Atropine , Dobutamine , Follow-Up Studies , Risk Factors , Sensitivity and Specificity , Time FactorsABSTRACT
PURPOSE: To study the safety and feasibility of dobutamine-atropine stress echocardiography (DASE) in patients with known or suspected coronary artery disease. METHODS: There were 3,000 DASE that were studied in a prospective fashion. All symptoms and side effects were stored in a data base format. RESULTS: Major test-related complications observed included one case of myocardial infarction, four cases of sustained ventricular tachycardia and five cases of atropine intoxication. There was no death or ventricular fibrillation as a direct or indirect consequence of the test. The infusion protocol allowed to us to examine patients using beta blockers, and led to 95% feasibility. CONCLUSION: DASE is a safe and feasible method for the study of patients with suspected or known coronary artery disease.
Subject(s)
Atropine , Cardiotonic Agents , Coronary Disease/diagnostic imaging , Dobutamine , Exercise Test , Adolescent , Adult , Aged , Aged, 80 and over , Atropine/adverse effects , Child , Child, Preschool , Dobutamine/adverse effects , Female , Humans , Male , Middle Aged , Prospective Studies , UltrasonographyABSTRACT
PURPOSE: To analyze the diagnostic accuracy of dobutamine-atropine stress echocardiography. METHODS: We studied 304 consecutive patients using dobutamine-atropine stress echocardiography who underwent coronary angiography within a month of the exam. Patients received high dobutamine doses associated or not with atropine. RESULTS: The global sensitivity was 92%, specificity was 72% and diagnostic accuracy was 87%. Analyzing 120 patients with normal LV function, we found sensitivity of 85%, specificity of 79% and accuracy of 82%. CONCLUSION: Dobutamine-atropine stress echocardiography is an accurate method for the detection of coronary artery disease.
