Mechanisms of muscular electrophysiological and mitochondrial dysfunction following exposure to malathion, an organophosphorus pesticide

Muscle dysfunction in acute organophosphorus (OP) poisoning is a cause of death in human. The present study was conducted to identify the mechanism of action of OP in terms of muscle mitochondrial dysfunction. Electromyography (EMG) was conducted on rats exposed to the acute oral dose of malathion (400 mg/kg) that could inhibit acetylcholinesterase activity up to 70%. The function of mitochondrial respiratory chain and the rate of production of reactive oxygen species (ROS) from intact mitochondria were measured. The bioenergetic pathways were studied by measurement of adenosine triphosphate (ATP), lactate, and glycogen. To identify mitochondrial-dependent apoptotic pathways, the messenger RNA (mRNA) expression of bax and bcl-2, protein expression of caspase-9, mitochondrial cytochrome c release, and DNA damage were measured. The EMG confirmed muscle weakness. The reduction in activity of mitochondrial complexes and muscular glycogen with an elevation of lactate was in association with impairment of cellular respiration. The reduction in mitochondrial proapoptotic stimuli is indicative of autophagic process inducing cytoprotective effects in the early stage of stress. Downregulation of apoptotic signaling may be due to reduction in ATP and ROS, and genotoxic potential of malathion. The maintenance of mitochondrial integrity by means of artificial electron donors and increasing exogenous ATP might prevent toxicity of OPs

Dynamic and volumetric variables reliably predict fluid responsiveness in a porcine model with pleural effusion

Background: The ability of stroke volume variation (SVV), pulse pressure variation (PPV) and global end-diastolic volume (GEDV) for prediction of fluid responsiveness in presence of pleural effusion is unknown. The aim of the present study was to challenge the ability of SVV, PPV and GEDV to predict fluid responsiveness in a porcine model with pleural effusions. Methods: Pigs were studied at baseline and after fluid loading with 8 ml kg−1 6% hydroxyethyl starch. After withdrawal of 8 ml kg−1 blood and induction of pleural effusion up to 50 ml kg−1 on either side, measurements at baseline and after fluid loading were repeated. Cardiac output, stroke volume, central venous pressure (CVP) and pulmonary occlusion pressure (PAOP) were obtained by pulmonary thermodilution, whereas GEDV was determined by transpulmonary thermodilution. SVV and PPV were monitored continuously by pulse contour analysis. Results: Pleural effusion was associated with significant changes in lung compliance, peak airway pressure and stroke volume in both responders and non-responders. At baseline, SVV, PPV and GEDV reliably predicted fluid responsiveness (area under the curve 0.85 (p<0.001), 0.88 (p<0.001), 0.77 (p = 0.007). After induction of pleural effusion the ability of SVV, PPV and GEDV to predict fluid responsiveness was well preserved and also PAOP was predictive. Threshold values for SVV and PPV increased in presence of pleural effusion. Conclusions: In this porcine model, bilateral pleural effusion did not affect the ability of SVV, PPV and GEDV to predict fluid responsiveness

Predicting cardiorespiratory instability

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency medicine 2016. Other selected articles can be found online at http://www.biomedcentral.com/collections/annualupdate2016. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901

Functional hemodynamic monitoring

PURPOSE OF REVIEW: To assess the recent literature on effective use of information received from hemodynamic monitoring. RECENT FINDINGS: Dynamic hemodynamic measures are more effective in assessing cardiovascular status than static measures. In this review, we will focus on the application of hemodynamic monitoring to evaluate the effect of therapy. SUMMARY: A systematic approach to an effective resuscitation effort can be incorporated into a protocolized cardiovascular management algorithm, which, in turn, can improve patient-centered outcomes and the cost of healthcare systems, by faster and more effective response in order to diagnose and treat hemodynamically unstable patients both inside and outside of intensive care units. © 2007 Lippincott Williams & Wilkins, Inc

Motor control changes in sagittal motion of lumbar spine following use of lumbosacral belt

Background: The changes in motor control after the use of a supportive belt can contribute to the understanding of its effects on performance. The aim of this study is to quantify motion pattern values relative to the spinal column during the use of a lumbosacral belt. Methods: For fifty healthy female volunteers, the range of motion, maximum isometric torque and changes of phase angle of maximum torque and velocity in two positions, standing and sitting, in two directions, flexion and extension, following the use of a lumbosacral belt were measured using an isoinertial dynamometer (Isostation B200) and compared. Results: Range of motion in both directions in both positions was reduced significantly (P&lt;0.05). Significant reduction of maximum isometric torque was observed in flexion while sitting and in extension while standing and sitting (P&lt;0.05). Phase angle of maximum torque and velocity also changed significantly in both directions and both positions (P&lt;0.05). Conclusion: The lumbosacral belt can act in different ways to prevent injury. It reduces the forces applied to lumbar vertebra and, by changing the maximum torque and velocity phase angles at the onset of range of motion, provides greater stability for joints. Furthermore, the belt can reduce stress imposed on the posterior joints of the spine and limits several momentary forces at the onset of joint movement. Under these conditions, joint injuries can be reduced and prevent some of the mechanical stress that causes lumbar joint disease

Effect of Strengthening Exercises on Serum C-Reactive Protein After Coronary Artery Bypass Grafts

Background: Strengthening exercises are not favored in the rehabilitation of patients after coronary artery bypass grafts (CABG) for concerns over potential adverse effects. However, patients often present with weakened skeletal muscles post CABG due to disuse. Methods: We studied the effects of aerobic and strengthening exercises on the serum C-reactive protein (CRP) levels and blood pressure in 79 post CABG patients aged 40-60 years. Patients were randomly assigned to one of four programs five days per week, consisting of either aerobic exercises alone (controls) or combined with strengthening exercises (experimentals) at moderate intensity. The serum CRP levels were quantified at the beginning, 12th and 24th sessions, and at 3-month follow-up. Patients blood pressure was measured before and after each exercise session. Patients were re-evaluated at 3-month follow-up. Results: There was a mild but significant increase in the CRP levels at 12th session in all groups. Patients. systolic blood pressures declined by 2%-7% at 12th and 24th sessions, respectively. There was no significant difference in changes of blood pressure among the groups. Conclusion: The results suggest that the four exercise programs were equally safe in low-risk, post CABG patients. Exercises did not promote a systemic inflammatory response. These beneficial effects were still evident at 3-month follow-up