Biomedical subjects

G Azimi

Publications and source records attributed to G Azimi.

5 recordsLinked to original sources

PubMed2001

Selective transport of silver ion through a supported liquid membrane using hexathia-18-crown-6 as carrier.

A facile supported liquid membrane (SLM) system for the selective and efficient transport of silver ion is introduced. The SLM used is a thin porous polyvinyldifluoride membrane impregnated with hexathia-18-crown-6 (HT18C6) dissolved in nitrophenyloctyl ether. HT18C6 acts as a specific carrier for the uphill transport of Ag+ ion as its picrate ion paired complex through the SLM. In the presence of thiosulfate ion as a suitable stripping agent in the strip solution, transport of silver occurs almost quantitatively after 4 h. The selectivity and efficiency of silver transport from aqueous solutions containing other Mn+ cations such as Mg2+, Ca2+, Co2+, Ni2+, Cu2+, Zn2+, Pb2+, Cd2+, Hg2+, Fe3+ and Cr3+ ions were investigated.

Chemical Phenomena↗

PubMed1987

Dopamine compared with dobutamine in experimental septic shock: relevance to fluid administration.

The hemodynamic effects of dopamine and dobutamine (at doses of 6 micrograms X kg-1 X min-1) were compared during fluid resuscitation from septic shock induced by endotoxin (3 mg/kg) in the dog. In the first part of the study, when a standard amount of saline solution was infused (in 24 dogs), dopamine infusion resulted in higher cardiac filling pressures than did dobutamine infusion, whereas dobutamine infusion resulted in higher cardiac output. In the second part of the study, when fluid infusion was titrated to maintain pulmonary artery balloon-occluded pressure at constant level (in 24 dogs), the total amount of fluids was significantly greater with dobutamine than when dopamine was used (109 +/- 13 vs 71 +/- 10 ml/kg). The combination of dobutamine with fluids resulted in significantly greater stroke volume (39.6 +/- 3.8 vs 21.0 +/- 4.0 ml, P less than 0.05) and oxygen consumption (194 +/- 18 vs 144 +/- 8 ml/min, P less than 0.05). The different effects of dopamine and dobutamine on cardiac filling pressures can be due to differences in effects on myocardial contractility, ventricular afterload, and cardiac compliance. This experimental study indicates that when fluid therapy is combined with adrenergic agents in resuscitation from septic shock, dobutamine can be associated with higher cardiac output and oxygen transport and can result in higher tissue oxygen consumption than dopamine.

Animals↗

PubMed1986

Ultimate survival from septic shock.

Detailed hemodynamic course during prolonged (less than 12 h) septic shock was studied in 23 patients, of whom 12 ultimately died from sepsis. Hemodynamic presentation was similar in fatalities and in survivors, except for a higher heart rate and a markedly higher blood lactate in fatalities (8.4 +/- 1.4 vs. 3.7 +/- 0.4 mEq/l, P less than 0.01). During fluid resuscitation, the pulmonary artery occlusive pressure associated with the highest left ventricular stroke work was usually around 17 mmHg, but in some patients above 20 mmHg. During the course of septic shock, left ventricular function improved in both fatalities and survivors, so that an altered cardiac function had no ultimate pejorative implication. The higher blood lactate in the absence of a different hemodynamic pattern tends to indicate that peripheral distributive defect remains the essential anomaly in septic shock. Arterial lactate appears to represent the most reliable indicator of ultimate prognosis in septic shock.

Aged↗

PubMed1986

Fluid resuscitation with hypertonic saline in endotoxic shock.

Hypertonic saline has been used in the treatment of hypovolemic or burn shock for its rapid volemic effects. Hypertonic solutions could also improve cardiac performance and protect cellular metabolism in acute circulatory failure. We therefore studied the hemodynamic effects of continuous hypertonic saline infusion in the treatment of severe endotoxic shock in the dog. Thirty minutes after slow injection of 3 mg/kg of Escherichia coli endotoxin, fluid resuscitation with either hypertonic saline containing 1,200 mOsm of NaCl/liter (eight dogs) or normotonic saline solution (eight dogs) was started and titrated to maintain left-sided filling pressures at control level. For the next 210 min, the total amount of fluid administered was 64.5 +/- 7.8 ml/kg in the hypertonic group and 83.6 +/- 10.3 ml/kg in the normotonic group. These differences were not statistically significant. Intravascular pressures were similar in the two groups, but cardiac output, stroke volume, and oxygen consumption were significantly higher in the hypertonic group. These results therefore indicate that hypertonic saline can rapidly restore oxygen transport and tissue oxygen consumption in septic shock. The duration of these hemodynamic effects, however, remains to be determined.

Animals↗

PubMedDate not supplied

Haemodynamic, gasometric and haematological effects of air infusion in dogs: leukotriene inhibition with U-60,257.

Air embolization has been shown to produce a reversible permeability-type of pulmonary oedema. The present study investigated the haemodynamic, gasometric and haematological changes associated with air infusion in the spontaneously breathing dog (weight 31 +/- 5 kg). Air was infused at a rate of 10 ml X min-1 for 60 min (10 dogs) or 180 min (5 dogs). During the air infusion, a dramatic increase in pulmonary artery pressure was associated with only a moderate increase in right atrial pressure and limited decreases in arterial pressure and in cardiac output. A marked decrease in end-tidal PCO2 reflected the increase in dead space. These changes were stable during air infusion, but rapidly reversed after the end of infusion. However, hypoxaemia, defined by a decreased PaO2/PAO2 ratio, deteriorated with time and was only partially reversible. At histological examination, interstitial pulmonary oedema was present around the pulmonary arterioles. Air infusion was associated with rapid decreases in circulating leukocytes and platelets and complement activation. Since leukotriene release might be associated with leukocyte activation in this model, seven additional dogs were pretreated by inhalation of 10 mg of the leukotriene inhibitor U-60,257. The increase in pulmonary vascular resistance and in pulmonary shunt were moderately reduced and the drop in circulating leukocytes and platelets was strikingly abolished in the treated animals. Air infusion in the spontaneously breathing dog represents a model of very stable and reversible pulmonary hypertension. It can reproduce important pathophysiological features implicated in the development of pulmonary oedema.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗