Summary
Using multiplane transoesophageal echocardiography (TOE), we investigated the haemodynamic response to acute normovolaemic haemodilution (ANH) in anaesthetised patients with critical aortic ...stenosis. Twenty‐eight patients were randomly assigned to ANH or control groups. In the control group, haemodynamic data remained unchanged over a 20‐min period. In the ANH group, haemoglobin levels decreased from a mean (SD) of 134 (7) to 91 (9) g.l−1 (p < 0.001) whereas stroke volume, central venous pressure and left ventricular (LV) end‐diastolic area all increased significantly (mean (SD) +15 (6) ml; +2.0 (1.1) mmHg; +2.1 (0.8) cm2, respectively). During ANH, the accelerated blood flow through the stenotic valve caused an increased loss (SD) in LV stroke work: from 24 (8)% to 30 (10)%), (p < 0.01). Hence, lowering viscosity with ANH resulted in improved venous return, higher cardiac preload and increased stroke volume. However, this adaptive haemodynamic response was limited by less efficient LV stroke work due to dissipation of fluid kinetic energy.
The contribution of the complement system to cerebral ischemic and ischemia/reperfusion injury was examined in a rabbit model of thromboembolic stroke by delivery of an autologous clot embolus to the ...intracranial circulation via the internal carotid artery. A two-by-two factorial design was employed to study the impact of complement depletion via pretreatment with cobra venom factor (CVF, 100 U/kg i.v.) in the setting of permanent (without tissue plasminogen activator; t-PA) and transient (with t-PA) cerebral ischemia. Thirty-two New Zealand white rabbits were assigned to one of four groups (
n = 8, each group): control without t-PA, control with t-PA, CVF without t-PA and CVF with t-PA. In the complement intact animals, t-PA administration resulted in an approximate 30% reduction in infarct size when compared to the group not receiving t-PA (20.4 ± 6.6% of hemisphere area vs. 30.1 ± 7.2%; mean ± SEM). However, infarct sizes in the complement depleted rabbits, with (30.7 ± 8.2%) or without (30.2 ± 7.9%) t-PA, were no different from the control group receiving no therapy. Similarly, no difference in regional cerebral blood flow or final intracranial pressure values was noted between any of the four groups. Complement activation does not appear to be a primary contributor to brain injury in acute thromboembolic stroke.
We present measurements of the magnetoresistance of a two-dimensional electron gas (2DEG) under continuous microwave as a function of the irradiation frequency. In a previous work by Simovič et al. ...Phys. Rev. B 71 (2005) 233303, the magnetoresistance under microwave was shown to be modulated by oscillations of large amplitude that are periodic with magnetic field, their period and phase depending strongly on the electron density. Here we show that the phase and the amplitude of the microwave-induced oscillations also depend on the frequency of irradiation and the sign of the magnetic field.
We hypothesized that lowering blood viscosity with acute normovolemic hemodilution (ANH) would confer additional cardioprotection in patients undergoing coronary artery bypass surgery (CABG) with ...aortic cross-clamping
In a prospective, randomized controlled trial, we studied the efficacy of ANH in anesthetized patients prior to cardiopulmonary bypass for the prevention of myocardial injuries
Cardiac surgical center in a university hospital
Patients scheduled to undergo elective CABG entered the study protocol and were randomly allocated to one of two groups: ANH (n = 43 patients) or standard care management (n = 41 patients). In the ANH group, the whole-blood/colloid exchange was aimed to achieve a hematocrit value of 28%. All patients were managed with standard myocardial preservation techniques including cold-blood cardioplegia and anesthetic preconditioning. The outcome measures included the release of myocardial enzymes (plasma troponin I and creatinine phosphokinase), perioperative hemodynamic changes, need for pharmacologic cardiovascular support, and cardiac complications
In the hemodilution group, the postoperative release of troponin I (mean peak plasma concentration, 1.4 ng/mL; 95% confidence interval, 1.0 to 1.8) and myocardial fraction of creatine kinase (mean, 29 U/L; 95% confidence interval, 23 to 35) were significantly lower than in the control group (mean, 3.8 ng/mL; 95% confidence interval, 3.2 to 4.5; and 71 U/L; 95% confidence interval, 53 to 89). Requirement for inotropic support was significantly lower in the protocol patients (7 of 41 patients vs 15 of 39 patients), and fewer patients presented with either atrial fibrillation, atrioventricular conduction blockade, or combined disorders (12 of 41 patients vs 26 of 39 patients, p < 0.05)
In addition to conventional myocardial preservation techniques, preoperative ANH achieved further cardiac protection in patients undergoing on-pump myocardial revascularization
Cowpox virus infection associated with a streptococcal septicaemia was diagnosed in a weak German Warmblood filly, born 29 days prematurely, and humanely destroyed on the sixth day of life. At ...necropsy, ulcerative lesions in the alimentary tract, colitis, polyarthritis and nephritis were observed. Transmission electron microscopical examination of specimens from ulcerative lesions revealed typical orthopox virions. Cowpox virus was unequivocally identified by virological and molecular-biological methods.
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