PubMed Health⌕ Search

Biomedical subjects

A Orrù

Publications and source records attributed to A Orrù.

17 recordsLinked to original sources

Mitochondrial genome involvement in ischemia/reperfusion-induced adaptive changes in human myocardial cells.

AIM: Following previous studies on the ischemia-induced adaptive changes in human cardiac mitochondria, we examined in the present paper the interaction between nitric oxide-induced (NO) partial inhibition of Cyt. c oxidase (Cyt.OX) and mitochondrial encoded subunit 2 expression. Aim of the study was to investigate specific stages of the biochemical and molecular cascade which takes place in cytoprotective mechanisms of ischemic and reperfused cardiac cell. METHODS: We examined human left ventricle samples obtained from 20 patients undergoing elective valve surgery before aortic cross-clamping, 20+/-2 min (prolonged ischemia), 58+/-5 min after cross-clamping (intermittent ischemia) and 21+/-4 min after reconstitution of coronary blood flow (reperfusion). Cyt.OX activity was determined by spectrophotometric method and adenosine triphosphate (ATP) content using bioluminescent assay. Malondialdehyde (MDA) assumed as reactive oxygen species (ROS) generation marker was determined by high-performance liquid chromatography method. On the same cardiac samples mitochondrial encoded Cyt.OX subunit 2 expression was examined by immunoblot analysis and blu native gel electrophoresis method. Statistical study of obtained data was performed using repeated measures analysis of variance (ANOVA). RESULTS: Prolonged as well intermittent ischemia caused reduction of Cyt.OX activity and ATP, a moderate accumulation of ROS and down-regulation of Cyt.OX subunit 2. When reperfused the cardiomyocytes showed a progressive increase of Cyt.OX activity, ATP pools and Cyt.OX subunit 2 expression. ROS generation was significantly increased by the rapid oxygen re-immission in the cardiac cell. CONCLUSIONS: These data confirm the suggestion that prolonged as well as intermittent ischemia induces activation of cytoprotective mechanisms crucial for cardiac cell survival. Indeed, co-ordinated down-regulation of Cyt.OX activities, ATP pools and mitochondrial encoded Cyt.OX subunit 2 are in favour of an ischemia-activated adaptive mechanism leading to transient and reversible oxidative injury. This observation is confirmed by reduction of apoptosis molecular markers and by complete recovery of mitochondrial oxidative activities in reperfused cardiac tissue.

Adaptation, Physiological↗

[Percutaneous cervical cordotomy in the therapy of incidence pain].

BACKGROUND: Incident pain does not respond to opioid treatment and it is not easily relieved with other therapeutic strategies (local intrapleural or spinal analgesia, phenol blocks etc.). For this reason cervical percutaneous cordotomy at C(1)-C(2) interspace is the only effective antalgic therapy in patients whose life expectancy is more than three to six months. METHODS: This study is a rectrospective review of 22 patients with cancer and incident pain from brachial, lumbar-sacral plexus injury and gluteal ulcer. RESULTS: Cordotomy provided excellent contralateral side pain relief in 21 patients; pain relief was maintained up to death and to the moment of last observation in living patients. In one deaf patient it was impossible to carry out the procedure due to incomplete co-operation and pain returned after 48 hours. Ventilatory depression caused death in one patient. Other complications recorded included ataxia, headache, motor deficit, dysesthesia and orthostatic hypotension. CONCLUSIONS: The conclusion is drawn that percutaneous cordotomy should, in carefully selected cases, be considered the only technique to relieve incident pain.

Adult↗

Deep sedation for magnetic resonance imaging. Personal experience.

AIM: Precision in diagnostic procedure and examination of paediatric patients often requires their absolute immobility. Deep sedation has proven to be an excellent method, allowing optimum technical quality of MRI particularly in younger age groups. The aim of study is to demonstrate the possible application of deep sedation through the use of 2 safe and manageable drugs. METHODS: We carefully evaluated and selected 82 patients (47 males and 35 females; average age 5.4 years): they came from various paediatrics departments. Deep sedation was practiced with: Chloral hydrate (60-80 mg/kg in one oral administration); propofol as intravenous bolus (2-2.5 mg/kg) followed by a maintenance infusion of 75-125 microg/kg/min. This was preceded by midazolam (0.05 mg/kg i.v.) outside the MRI room. Oxygen saturation (SpO2) was monitored in all patients along with heart rate in order to foresee the need for any possible therapeutic intervention. RESULTS: The sedation levels attained permitted the success of MRI assuring the immobilization required. Manually assisted mask ventilation was required for a period of 2-3 min in 5 patients treated with propofol. All other patients breathed autonomously. Complete reawakening occurred within 2 hours of drug administration. Surveillance was prolonged inside their respective units, however, without registering delayed side effects. CONCLUSION: The central point of the success of deep sedation is to define the type and dose of optimum drug for individual patients. This requires a qualified, expert group ready to intervene in the presence of adverse results of drugs administered. Propofol and chloral hydrate are the optimum drugs for diagnostic techniques requiring total immobilization and rapid reawakening.

Child, Preschool↗