Clearance of differentially labelled infused hemoglobin and polymerized hemoglobin from dog plasma and accumulation in urine and selected tissues

Pyridoxalated hemoglobin polymerized with glutaraldehyde has been proposed as a hemoglobin based blood substitute. The preparations contain significant amounts of unpolymerized hemoglobin. We have prepared polymerized pyridoxalated hemoglobin labelled with 14C by reductive methylation free of unpolymerized hemoglobin and pyridoxalated hemoglobin labelled with 3H by reductive methylation to compare the handling of the two forms after infusion into dogs. Four dogs were examined sequentially. After three hours, 52.4 +/- 8.9% of the 3H label had disappeared from plasma whereas 21.7 +/- 5.8 of the 14C label had disappeared. The decrease of both labels occurred in a very close to linear fashion over the time period examined. From radioactivity in collected urine, it was calculated that 30.7 +/- 6.3% of the 3H and 9.0 +/- 2.7 of the 14C that had been cleared from plasma appeared in urine. The ratio of the specific radioactivity in tissue to the specific radioactivity of plasma indicated that extravascular accumulation of 3H label from unpolymerized hemoglobin occurred in kidney, heart and liver, with the kidney cortex exhibiting a very high concentration of the label. The specific radioactivity of both 3H and 14C label in liver suggested the substantial involvement of the reticuloendothelial system in the removal of both unpolymerized and polymerized hemoglobin from the circulation.

Resuscitation of bled dogs with pyridoxalated-polymerized hemoglobin solution

We bled 25% of estimated total blood volume, then infused pyridoxalated polymerized human stroma-free hemoglobin solution (PP-SFH) (10 g/dl) to dogs under anesthesia in a volume equal to the blood removed. Central hemodynamics, blood flow distribution to organs, and renal function were studied up to 2-3 hours following the infusion. Mean arterial pressure was reduced from 120 +/- 3 to 86 +/- 7 mmHg at the end of the 30-minute hypovolumic period and the cardiac output was reduced by 27%. Immediately following the PP-SFH infusion we observed a further fall in blood pressure (43%) caused by a fall in cardiac output which lasted for 10 minutes. Blood pressure was restored gradually with the continuation of the infusion and the cardiac output was restored and maintained well. During the hypovolumic period, blood flow to the heart, renal cortex, and liver were reduced, whereas normal flow to the renal medulla and brain were maintained. After the resuscitation, blood flow to the heart, brain, liver, and renal medulla significantly exceeded the normal range, but remained subnormal in the renal cortex. Glomerular filtration rate (GFR), urine flow, and electrolyte excretion were all reduced during the hypovolumic period and were not restored to the pre-bleed levels after the infusion.

New salary system supports changing culture

Changing job classification, salary administration and benefits programs for the sake of change can create considerable problems in an organization. However, as the organizational culture changes, these HR systems need to adjust to help the process. Associate involvement requires considerable planning, time and effort, but the results often prove worthwhile. As the company moves into the future, this involvement process or something similar will help shape other human resource programs.

In vivo effects of stroma-free hemoglobin and polyhemoglobin on coagulation factors in rats

We studied the effects of rat stroma-free hemoglobin (rSFH), human stroma-free hemoglobin (hSFH), rat polyhemoglobin (rPoly), and human polyhemoglobin (hPoly) on coagulation factors in rats. Albumin and saline infused rats were controls. The infusion volume was 10% of the rat's blood volume. The concentrations of hemoglobin in this study were 7 g/dl. Measurements for prothrombin time (PT) and activated partial thromboplastin time (PTT) were at 5 minutes, 2, 6, 24 and 72 hours after infusion. Factor X, fibrinogen, plasminogen, antithrombin III, and antiplasmin were followed at 24 and 72 hours after infusion. Compared with saline infused rats PT and PTT did not change significantly in those rats infused with Hb preparations. There was a transient increase of PTT from 2 to 24 hours after infusion in albumin infused rats. Factor X, fibrinogen, antithrombin III and antiplasmin showed no significant differences between Hb infused groups and saline infused group. Twenty-four hours and 72 hours after infusion plasminogen decreased in all groups except the albumin infused rats at 24 hours after infusion when compared with normal rat plasma pool. However, there were no significant differences in plasminogen levels between the hemoglobin infused groups and the control saline group. Stroma-free and polyHb solutions (rSFH, hSFH, rPoly and hPoly) did not cause significant changes in prothrombin time and activated partial thromboplastin time in rats. The rats infused with hemoglobin solutions (rSFH, hSFH, rPoly, and hPoly) did not show significant differences in Factor X, fibrinogen, antithrombin III and antiplasmin levels compared with the control group.

Effects of homologous and heterologous stroma-free hemoglobin and polyhemoglobin on complement activation, leucocytes and platelets

This is a study of the effects of stroma-free hemoglobin(Hb) and polyhemoglobin on C3 and C3a levels and on blood cell counts. The effects of membrane stroma from red cells and endotoxins on complement activation were also investigated. Plasma samples from rats were incubated with hemoglobin solutions or control solutions. C3 was measured using anti-rat C3 by nephelometric method. C3a was measured using radioimmunoassay. C3 and C3a were also determined in rats receiving hemoglobin solutions, red cell stroma solutions, or a solution containing complement activators (membrane stroma and bacterial endotoxins). There were no significant differences in C3 or C3a levels between the plasma incubated with hemoglobin solutions and the control plasma incubated with saline (P greater than 0.05). Compared with the saline incubated plasma, C3 was significantly lower and C3a significantly higher in the zymosan treated plasma (P less than 0.01). In hemoglobin infused rats, there was no significant difference between pre-versus post-infusion values in C3 and C3a. There was a significant increase in C3a in the rats receiving stroma suspension (P less than 0.05) or stroma and endotoxins (P less than 0.02). Polyhemoglobin and stroma-free hemoglobin did not cause significant changes in total leucocyte, differential, or platelet counts. Our study suggests that purified stroma-free Hb and polyHb do not activate complement, and that C3a is a more sensitive parameter for monitoring complement activation than C3. On the other hand, contaminates in hemoglobin preparations, such as membrane stroma or endotoxins, activate the complement system.

Whole complement hemolytic activity (CH50) following infusion of stroma-free and polyhemoglobin solutions in rats

We developed a method to determine whole complement hemolytic activity (CH50) in rat plasma using a modification of the method of Mayer(1). Plasma CH50 level in 30 male Sprague Dawley rats was 1000 +/- 200 units. Following infusions with human and rat stroma-free hemoglobin or polyhemoglobin solutions, CH50 did not change significantly in rats when compared to albumin infused rats. On the other hand, CH50 significantly decreased in the group receiving membrane stroma and bacterial endotoxins.

Effects of pyridoxalated polyhemoglobin and stroma-free hemoglobin on ADP-induced platelet aggregation

Although polyhemoglobin produced from homologous sources is not immunogenic when utilized in vivo (1), effects on hemostasis and thrombosis have not been documented. In this study, we use rat platelet rich plasma (PRP) and light transmission aggregometry to measure the possible influence of stroma-free hemoglobin (SFHb) and pyridoxalated polyhemoglobin (PP-PolyHb) on platelet aggregation in response to various levels of adenosine triphosphate (ADP) activation in vitro. Our study demonstrates that PP-PolyHb and SFHb solutions, when added to PRP in volumes and concentrations likely to be administered to patients requiring perfusant therapy, do not initiate or facilitate platelet activation. Both solutions induce similar levels of aggregation (and presumably activation) inhibition, but do so only at high or maximal levels of ADP activator stimulation, late in the aggregation sequence. The apparent inability of the purified hemoglobins to stimulate platelets is a necessary characteristic if such preparations are to be used as clinical perfusants in hemorrhagic emergencies.

Placental transfer of quazepam in mice

The disposition of 14C-quazepam following a single 5-mg/kg po dose was studied at the postembryonic period (day 12 of pregnancy) and near-term (day 18 of pregnancy). In both 12- and 18-day pregnant mice, radioactivity from the quazepam dose was widely distributed in the maternal tissues, with the highest levels in the liver and kidneys. At the time points analyzed (1, 5, and 24 hr post-dose), radioactivity levels in the fetus were consistently 44% of the maternal plasma levels in 12-day pregnant mice. In 18-day pregnant mice, fetal radioactivity levels at these time points were consistently equal to or slightly greater than maternal plasma levels. This indicates that radioactivity was taken up and eliminated from fetal tissues at rates that were reasonably similar to those in corresponding maternal tissues. No accumulation of radioactivity was observed in the fetus or in maternal tissues in either the 12-day or the 18-day pregnant mice. In 18-day pregnant mice, concentrations of quazepam and its metabolites were measured either by gas-liquid chromatography or thin layer radiochromatography. In the maternal plasma, concentrations of quazepam, its first-formed metabolite, 2-oxoquazepam, and 3-hydroxy-2-oxoquazepam were relatively low at all time points; levels of N-desalkyl-2-oxoquazepam and 3-hydroxy-N-desalkyl-2-oxoquazepam (HDOQ) were much higher. Fetal levels of unchanged drug and metabolites were generally less than or equal to maternal plasma levels, except for HDOQ levels, which were higher in the fetus.(ABSTRACT TRUNCATED AT 250 WORDS)

Disposition and metabolic fate of 14C-quazepam in man

The absorption, metabolism, and excretion of quazepam, a new benzodiazepine hypnotic, was investigated in six normal male volunteers after oral administration of 25 mg 14C-quazepam in solution. Quazepam was well absorbed. Plasma radioactivity peaked (324.6 ng quazepam eq/ml) 1.75 hr postdose. Unchanged quazepam reached its maximum plasma level (148 ng/ml) at 1.5 hr with an apparent absorption half-life of 0.4 hr. Major plasma metabolites of quazepam were 2-oxoquazepam (OQ), obtained by replacement of S by O,N-desalkyl-2-oxoquazepam (DOQ), and 3-hydroxy-2-oxoquazepam (HOQ) glucuronide. Both OQ and DOQ are pharmacologically active. Plasma elimination half-lives for quazepam, OQ, DOQ, and radioactivity were 39, 40, 69, and 76 hr, respectively. The respective AUC (120 hr) values were 715, 438, 3323, and 11402 hr X ng/ml. Approximately 54% of the radioactive dose was excreted in the urine (31.3%) and feces (22.7%) over a 5-day period. HOQ glucuronide was the major urinary metabolite of quazepam. Other metabolites present in the urine in relatively large amounts were glucuronides of DOQ and HDOQ.