Rapid correction of low vitamin D status in nursing home residents.

UNLABELLED: This prospective study finds that ergocalciferol 50,000 IU three times weekly for four weeks effectively and safely corrects vitamin D inadequacy in nursing home residents. INTRODUCTION: Low vitamin D status is common among nursing home residents and contributes to bone loss, falls and fractures. The objective of this study was to evaluate the efficacy and safety of short course, high dose, oral vitamin D(2) (ergocalciferol) treatment. METHODS: This prospective study included 63 nursing home residents. The 25 with low vitamin D status (serum 25(OH)D < or = 25 ng/ml) received oral ergocalciferol 50,000 IU three times weekly for four weeks; the others received no change to their routine care. Serum total 25(OH)D, 25(OH)D(2), 25(OH)D(3), calcium, parathyroid hormone (PTH), bone turnover markers and neuro-cognitive assessments were obtained at baseline and four weeks. RESULTS: Mean total 25(OH)D concentration increased (p < 0.0001) from 17.3 to 63.8 ng/ml in the treated group and remained unchanged in the comparison group. Serum 25(OH)D(3) remained stable in the comparison group, but declined (p < 0.0001) with D(2) treatment from 15.4 to 9.1 ng/ml. Serum PTH trended down in the treatment group (p = 0.06). No treatment-induced improvement in ambulation, cognition or behavior was observed. No hypercalcemia or other adverse effects were observed with ergocalciferol treatment. CONCLUSION: Four weeks of oral vitamin D(2) supplementation effectively and safely normalizes serum 25(OH)D in nursing home residents.

A randomized, single-blind, increasing dose safety trial of an oxygen-carrying plasma expander (Hemospan) administered to orthopaedic surgery patients with spinal anaesthesia.

The objective of this study was to further explore the safety of Hemospan (Sangart Inc., San Diego, CA, USA), an oxygen-carrying plasma expander. The aim of this study was to determine if Hemospan is well tolerated in orthopaedic surgery patients with spinal anaesthesia in doses up to 1 L. Hemospan was previously found to be well tolerated in normal volunteers and orthopaedic surgery patients with spinal anaesthesia in doses up to 500 mL. Five cohorts of six orthopaedic surgery patients, American Society of Anesthesiologists (ASA) I and II, were studied. In each cohort, four patients received Hemospan in doses ranging from 200 to 1000 mL, and two received Ringer's lactate immediately prior to induction of spinal anaesthesia. There were no serious adverse events (SAEs). Iohexol clearance measured before and 24 h after dosing was unaffected. There were 14 adverse events (AEs) in the 10 control patients (1.4 per patient) and 30 in the 20 patients receiving Hemospan (1.5 per patient). One patient in the group receiving 200 mL Hemospan had elevated mean arterial pressure after dosing, but there were no elevations in any of the other patients. The peak plasma Hemospan concentration in the 1000 mL group was 1.3 g dL(-1), with a dose-dependent clearance (T(1/2)) ranging from 14.1 to 23.0 h. Plasma methaemoglobin levels were independent of dose, reaching a maximum at 40 h after dosing and never exceeded 0.125 g dL(-1). Troponin T was transiently elevated in two patients receiving Hemospan without symptoms or electrocardiographic abnormalities or elevation of myocardial creatinine kinase isoenzyme. Hemospan was well tolerated in this group of patients at doses up to 1000 mL.

Falls in the geriatric patient.

Falls are common in the geriatric and older adult population, often causing significant morbidity or mortality. The geometry of the human body in motion requires a highly functional individual to remain balanced and upright under a variety of conditions and perturbations. Balance in this population is adversely affected by intrinsic and extrinsic factors. Medications' therapeutic and side effects frequently contribute to falls. An aggressive approach to falls reduction, including eliminating balance-altering medication, obtaining sub-specialty and balance evaluations when warranted, and requesting home safety assessments is advocated in this review of the current concepts and literature.

Randomized trial of diaspirin cross-linked hemoglobin solution as an alternative to blood transfusion after cardiac surgery. The DCLHb Cardiac Surgery Trial Collaborative Group.

BACKGROUND: Risks associated with transfusion of allogeneic blood have prompted development of methods to avoid or reduce blood transfusions. New oxygen-carrying compounds such as diaspirin cross-linked hemoglobin (DCLHb) could enable more patients to avoid allogeneic blood transfusion. METHODS: The efficacy, safety, hemodynamic effects, and plasma persistence of DCLHb were investigated in a randomized, active-control, single-blind, multicenter study in post-cardiac bypass surgery patients. Of 1,956 screened patients, 209 were determined to require a blood transfusion and met the inclusion criteria during the 24-h post-cardiac bypass period. These patients were randomized to receive up to three 250-ml infusions of DCLHb (n = 104) or three units of packed erythrocytes (pRBCs; n = 105). Further transfusions of pRBCs or whole blood were permitted, if indicated. Primary efficacy end points were the avoidance of blood transfusion through hospital discharge or 7 days postsurgery, whichever came first, and a reduction in the number of units of pRBCs transfused during this same time period. Various laboratory, physiologic, and hemodynamic parameters were monitored to define the safety and pharmacologic effect of DCLHb in this patient population. RESULTS: During the period from the end of cardiopulmonary bypass surgery through postoperative day 7 or hospital discharge, 20 of 104 (19%) DCLHb recipients did not receive a transfusion of pRBCs compared with 100% of control patients (P < 0.05). The overall number of pRBCs administered during the 7-day postoperative period was not significantly different. Mortality was similar between the DCLHb (6 of 104 patients) and the control (8 of 105 patients) groups. Hypertension, jaundice/hyperbilirubinemia, increased serum glutamic oxalo-acetic transaminase, abnormal urine, and hematuria were reported more frequently in the DCLHb group, and there was one case of renal failure in each group. The hemodynamic effects of DCLHb included a consistent and slightly greater increase in systemic and pulmonary vascular resistance with associated increases in systemic and pulmonary arterial pressures compared with pRBC. Cardiac output values decreased more in the DCLHb group patients after the first administration than the control group patients. At 24 h postinfusion, the plasma hemoglobin level was less than one half the maximal level for any amount of DCLHb infused. CONCLUSIONS: Administration of DCLHb allowed a significant number (19%) of cardiac surgery patients to avoid exposure to erythrocytes postoperatively.

Controlled safety study of a hemoglobin-based oxygen carrier, DCLHb, in acute ischemic stroke.

BACKGROUND AND PURPOSE: Diaspirin cross-linked hemoglobin (DCLHb) is a purified, cell-free human hemoglobin solution. In animal stroke models its use led to a significant reduction in the extent of brain injury. The primary objective of this study was to evaluate the safety of DCLHb in patients with acute ischemic stroke. METHODS: DCLHb or saline was administered to 85 patients with acute ischemic stroke in the anterior circulation, within 18 hours of onset of symptoms, in a multicenter, randomized, single-blind, dose-finding, controlled safety trial, consisting of 3 parts: 12 doses of 25, 50, and 100 mg/kg DCLHb over 72 hours. RESULTS: DCLHb caused a rapid rise in mean arterial blood pressure. The pressor effect was not accompanied by complications or excessive need for antihypertensive treatment. Two patients in the 100 mg/kg group had adverse events that were possibly drug related: one suffered fatal brain and pulmonary edema, the other transient renal and pancreatic insufficiency. Multivariate logistic regression analysis showed that a severe stroke at baseline and treatment with DCLHb (OR, 4.0; CI, 1.4 to 12.0) were independent predictors of a worse outcome (Rankin Scale score of 3 to 6) at 3 months. CONCLUSIONS: Outcome scale scores were worse in the DCLHb group, and more serious adverse events and deaths occurred in DCLHb-treated patients than in control patients. We recommend that additional safety studies be performed, preferably with a second generation, genetically engineered hemoglobin.

A safety assessment of diaspirin cross-linked hemoglobin (DCLHb) in the treatment of hemorrhagic, hypovolemic shock.

OBJECTIVE: To determine the safety and possible efficacy of diaspirin cross-linked hemoglobin (DCLHb) in the treatment of patients in Class II-IV hemorrhagic, hypovolemic shock. DESIGN: Multicenter, randomized, normal saline-controlled, dose-escalation study. SETTING: Eleven hospitals in the U.S. and Belgium. SUBJECTS: One hundred and thirty-nine (139) hospitalized patients with Class II-IV hemorrhagic, hypovolemic shock within the previous 4 hours who still were requiring therapy for shock. INTERVENTIONS: Beginning with the lowest dose, patients were randomized to receive 50, 100, or 200 mL of either 10% DCLHb or normal saline infused intravenously over 15 minutes. Following infusion of either treatment, further fluid resuscitation could be given, as necessary, to maintain perfusion. Vital signs, laboratory assessments, blood and fluid administration, complications, and adverse events were recorded at various times from the end of infusion through 72 hours after infusion. RESULTS: A total of 29 (13 DCLHb- and 16 saline-treated) patients died during the study period. Adverse events were experienced by 61% of patients in the DCLHb group and 53% of patients in the saline group; serious adverse events occurred in 28% of DCLHb-treated patients and 30% of saline-treated patients. The incidence of prospectively defined, clinical complications, including renal insufficiency and renal failure, was similar between the treatment groups except for the occurrence of dysrhythmias/conduction disorders, which occurred significantly more frequently in the saline-treated patients than the DCLHb-treated patients (p = 0.041). At the highest dose level (200 mL), statistically significant between-group differences were observed with greater increases in serum amylase, LDH, the isoenzymes LD1,2,4 and 5, and CK-MB in the DCLHb group compared to the control group; none were of clinical significance. The volume of blood administered did not differ between the groups. Overall 24- and 72-hour survival rates were similar between treatment groups, although the hospital discharge rate was slightly higher in the DCLHb-treated patients (80%) compared with the saline-treated patients (74%). CONCLUSION: Administration of 50 to 200 mL of DCLHb to patients in hemorrhagic, hypovolemic shock was not associated with evidence of end organ toxicity or significant adverse events. Further studies involving larger doses and, perhaps, earlier administration of DCLHb are warranted.

Effect of diaspirin cross-linked hemoglobin on endothelin-1 and blood pressure in acute ischemic stroke in man.

OBJECTIVE: For almost 50 years it has been known that hemolysed blood can increase blood pressure. Although preclinical studies suggest that this pressor response is due to an interaction of hemoglobin with endothelium-derived vasoactive substances, its mechanism in humans is unknown. We investigated the involvement of endothelin-1 in the blood pressure response to the oxygen carrier diaspirin cross-linked hemoglobin (DCLHb) in stroke patients. DESIGN: In a randomized phase II study, increasing doses of DCLHb (25, 50 and 100 mg/kg, n=8, 8 and 11, respectively) or placebo (n=26) were infused intravenously every 6 h for 72 h to patients with an acute ischemic stroke. Blood pressure and heart rate were measured every 15 min and plasma concentrations of endothelin-1, catecholamines, renin, vasopressin and atrial natriuretic peptide were measured before and 24 and 66 h after the start of the infusions. RESULTS: In the placebo group, mean arterial pressure (MAP) was 112 (109-115) mmHg (mean and 95% confidence interval) at baseline and decreased spontaneously by 11.4 (5.4-17.5) and 12.5 (5.4-19.5) mmHg after 24 and 66 h, respectively. This decrease in MAP was attenuated in patients treated with DCLHb, reaching statistical significance in the highest dose group. The plasma endothelin-1 concentration decreased slightly in the placebo group, from 4.2 (3.1-5.3) pg/ml (median and range) at baseline to 2.4 (1.9-3.7) pg/ml after 24 h (P=0.0044) and 2.8 (1.9-3.7) pg/ml after 66 h (P=0.0042), but increased dose-dependently in response to DCLHb infusion. With the highest dose of DCLHb, the plasma endothelin-1 concentration rose from 4.8 (0.1-7.8) pg/ml at baseline to 21.2 (13.4-53.2) pg/ml after 24 h (P< 0.001) and to 27.6 (11.9-47.8) pg/ml after 66 h (P< 0.001). The increases in the plasma endothelin-1 concentration and in MAP were correlated (r=0.30, P=0.02). Other vasoactive hormones were not affected by the DCLHb infusion. CONCLUSIONS: Infusion of DCLHb in patients with acute ischemic stroke was associated with a dose-dependent increase in plasma endothelin-1 concentration. This may underlie the attenuation by DCLHb of the natural decrease in blood pressure that we observed in these patients.

Initial evaluation of diaspirin cross-linked hemoglobin (DCLHb) as a vasopressor in critically ill patients.

OBJECTIVE: To evaluate the hemodynamic effects and any toxicologic effects of diaspirin cross-linked hemoglobin (DCLHb) in critically ill patients. DESIGN: A prospective, observational study. SETTING: A seven-bed intensive care unit (ICU) in a University teaching hospital. PATIENTS: Fourteen critically ill patients requiring vasopressor therapy to maintain adequate mean arterial pressure (MAP). All patients had secondary organ dysfunction. INTERVENTIONS: Administration of 100 mL boluses of 10% diaspirin cross-linked hemoglobin, up to a maximum of 500 mL, given over 15 mins and separated by 60 to 90 mins. MEASUREMENTS AND MAIN RESULTS: Hemodynamic parameters, norepinephrine and inotropic requirements, arterial and mixed venous blood gases, urine output, and biochemical and hematologic analyses were measured before diaspirin cross-linked hemoglobin administration and at multiple time points up to 72 hrs. MAP was maintained at approximately preinfusion values and the reduction in norepinephrine requirements was used as the main end point to assess the efficacy of diaspirin cross-linked hemoglobin as a vasopressor. Diaspirin cross-linked hemoglobin demonstrated a marked vasopressor action, allowing norepinephrine requirements to be reduced from 0.29 +/- 0.15 (SD) microgram/kg/min to 0.15 +/- 0.14 and 0.07 +/- 0.10 microgram/kg/min after the first (at 1.5 hrs, p < .001) and last (at 7.5 hrs, p < .0001) boluses, respectively. These reductions in norepinephrine requirements were maintained at 24, 48, and 72 hrs (p < .01 at all time points). These hemodynamic changes began within 5 mins of starting the diaspirin cross-linked hemoglobin infusion. MAP, heart rate, central venous pressure, pulmonary artery occlusion pressure, mean pulmonary arterial pressure (MPAP), systemic vascular resistance index, and urine output did not demonstrate any significant changes from preinfusion values. Pulmonary vascular resistance index increased at 7.5 hrs despite nonsignificant increases in MPAP. Cardiac index and oxygen delivery index decreased significantly at 7.5 hrs and 24 hrs. Total plasma bilirubin increased significantly from baseline at 24 and 48 hrs, before returning to baseline values within 5 days. Platelet count was significantly reduced at 6 and 24 hrs. No other biochemical or hematologic analyses were altered significantly post diaspirin cross-linked hemoglobin. CONCLUSIONS: This preliminary study demonstrated that diaspirin cross-linked hemoglobin is a potent vasopressor agent in critically ill patients with septicemic shock or systemic inflammatory response syndrome. This vasopressor characteristic of diaspirin cross-linked hemoglobin may have future clinical applications.

The effects of diaspirin-crosslinked hemoglobin on the assessment of immunohematology profiles.

BACKGROUND: Extensive studies have been conducted on the in vitro effects of diaspirin-crosslinked hemoglobin (DCLHb) in biochemical, hematologic, hemostatic, and blood banking (immunohematologic) methods. The absence of red cell antigens or plasma and/or serum antibodies allows DCLHb to be used as "universal-donor" material. This study evaluates the effects of DCLHb on the accurate assessment of the immunohematologic profile (ABO and Rh blood grouping, antibody screen, and crossmatching). STUDY DESIGN AND METHODS: DCLHb, 7.4 g per dL in an electrolyte solution, was mixed in vitro with human whole blood, representing the blood types A Rh-positive. A Rh-negative, B Rh-positive, B Rh-negative, O Rh-positive, O Rh-negative, and AB Rh-positive. Two concentrations of DCLHb were tested: 10-percent (0.74 g/dL) and 30-percent (2.22 g/dL). Controls were prepared by adding a 5-percent albumin solution to aliquots of whole blood in volumes equivalent to those used in preparing the DCLHb dilutions. Serum and/or red cell suspensions from these admixed samples were analyzed for their ABO and Rh blood groups, the presence of unexpected antibodies (antibody screen), and compatibility in crossmatch testing. RESULTS: DCLHb added to whole blood in vitro had no effect on the accurate interpretation of the immunohematologic profile. CONCLUSION: DCLHb does not appear to inhibit the true response or crossreact in the analysis of blood grouping, antibody screening, or crossmatching. In addition, the red color of DCLHb (up to 2.22 g/dL) did not obscure the visual reading for agglutination.

Phase I study of the safety and pharmacologic effects of diaspirin cross-linked hemoglobin solution.

OBJECTIVE: To evaluate the safety, pharmacokinetics, and pharmacodynamics of diaspirin cross-linked hemoglobin solution (DCLHb) in normal, healthy volunteers. DESIGN: Randomized, double-blind, controlled, crossover study. SETTING: Phase I research facility of a contract research organization. PATIENTS: Twenty-four healthy adult volunteers. INTERVENTIONS: Diaspirin cross-linked hemoglobin solution (25, 50, or 100 mg/kg) or equal volume of lactated Ringer's solution was infused on day 1; the alternate solution was infused 6 days later. Laboratory analyses, electrocardiograms, and Holter and telemetry monitoring were performed to assess organ function, pharmacokinetics, and potential toxicity. Vital signs, pulse oximetry, laser Doppler flowmetry, and toe temperature were measured to evaluate diaspirin cross-linked hemoglobin solution's pharmacodynamic effects. MEASUREMENTS AND MAIN RESULTS: There were no serious adverse events associated with diaspirin cross-linked hemoglobin solution infusion. Abdominal pain occurred in three subjects after control infusion and in six subjects after diaspirin cross-linked hemoglobin solution infusion; no treatment was required. A dose-related increase in lactic dehydrogenase (LDH)-5 isoenzyme concentrations was observed in 12 subjects after diaspirin cross-linked hemoglobin solution infusion. There were no associated increases in the circulating concentrations of total LDH, aspartate aminotransferase, alanine aminotransferase, or alkaline phosphatase. Total serum creatine kinase concentrations increased significantly after infusion of 100 mg/kg of diaspirin cross-linked hemoglobin solution; the isoenzyme creatine kinase-myocardial band (CK-MB) was not increased, nor were there any abnormal electrocardiogram findings. There were no differences in laser Doppler, pulse oximetry, or toe temperature measurements during or after either infusion. The half-life of diaspirin cross-linked hemoglobin solution was 2.5 hrs for the 25- and 50-mg/kg doses and 3.3 hrs for the 100-mg/kg dose. A dose-related increase in blood pressure occurred with diaspirin cross-linked hemoglobin solution. CONCLUSIONS: Diaspirin cross-linked hemoglobin solution doses of 25, 50, and 100 mg/kg are well tolerated, without evidence of organ dysfunction or toxicity. Diaspirin cross-linked hemoglobin solution's pressor effect is without evidence of decreased peripheral perfusion. Further investigations of its use in certain patient populations are warranted.

Pharmacologic profile of diaspirin cross-linked hemoglobin in hemodialysis patients.

Various hemoglobin compounds have been evaluated as potential oxygen-carrying, blood volume expanders, but toxicity has prevented clinical application. Diaspirin cross-linked hemoglobin (DCLHb) represents a modified hemoglobin compound that is derived from human red blood cells and maintained in a tetrameric configuration by cross-linkages between the two alpha chains of the hemoglobin molecule. In a randomized, placebo-controlled, single-blind, cross-over trial, DCLHb's safety and pharmacologic parameters were evaluated in 18 subjects receiving chronic hemodialytic therapy. A 30-minute infusion of 25, 50, or 100 mg/kg DCLHb or placebo was given at the start of routine hemodialysis. One week later, the alternate treatment (placebo or DCLHb) was administered. Maximum plasma hemoglobin concentrations and terminal half-life values were calculated for each dosage group. Dialysate was collected and assayed for hemoglobin. Changes in systolic and diastolic blood pressure from baseline and the volume of hypertonic saline administered for treatment of hypotension during hemodialysis were measured. The maximum plasma hemoglobin concentrations increased with DCLHb dose and occurred at the end of DCLHb infusion. The mean (+/- SD) terminal half-life ranged from 2.1 +/- 1.0 hours in the 25 mg/kg DCLHb group to 4.3 +/- 1.4 hours in the 100 mg/kg group, but did not differ significantly between groups. Mean baseline plasma hemoglobin corrected areas under the plasma concentration-time curves increased from 89 to 1,136 mg/hr/dL across the fourfold dose range. Diaspirin cross-linked hemoglobin was not dialyzable as none was detected in dialysate. The maximum increase in systolic blood pressure from baseline increased significantly with DCLHb dose compared with placebo (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Diaspirin crosslinked hemoglobin (DCLHb) does not affect the anesthetic potency of isoflurane in rats.

Hemoglobin solutions are being developed as oxygen carrying fluids for multiple clinical indications. Despite an early report of accentuation of ether anesthesia, the effect of hemoglobin on anesthetic potency has not been assessed. We assessed the effect of alpha-alpha diaspirin crosslinked hemoglobin (DCLHb) on the anesthetic requirement of isoflurane necessary to keep rats unresponsive to noxious stimuli (1.0 MAC [minimum alveolar concentration]). During isoflurane administration, each rat received one of the following fluid regimens: 44Hct/N-normal hematocrit and volume; 44Hct/H-8.0 ml of donor blood given as a hypervolemic bolus; 30Hct/H-5.0 ml of DCLHb given as an exchange transfusion and 8.0 ml as a hypervolemic bolus; or 16Hct/H-15.0 ml of DCLHb given as an exchange transfusion and 8.0 ml as a hypervolemic bolus. MAC was determined using a standard tail clamp technique. The isoflurane requirement to achieve 1.0 MAC was not different between the four groups. These results are consistent with a hypothesis that DCLHb does not change the anesthetic state.

Focal cerebral ischemia in rats: effect of hemodilution with alpha-alpha cross-linked hemoglobin on CBF.

Hemodilution has had limited success as a treatment of cerebral ischemia. When using a nonoxygen binding fluid, the therapeutic efficacy of hemodilution-induced increases in CBF are offset by concomitant decreases in oxygen content. The effect of hemodilution, with diaspirin alpha-alpha cross-linked hemoglobin (DCLHb), on CBF during middle cerebral artery occlusion was assessed. Rats were hemodiluted to one of the following hematocrits (Hct): (a) 44/Hct, (b) 37/Hct, (c) 30/Hct, (d) 23/Hct, (e) 16/Hct, or (f) 9/Hct. After 10 min of ischemia, CBF was determined with 14C-iodoantipyrine. Coronal brain sections were evaluated for areas with a CBF of 0-10 and 11-20 ml 100 g-1 min-1. In addition, oxygen delivery was calculated. In the center of the ischemic zone, both areas of low CBF were less in the 30/Hct, 23/Hct, and 16/Hct groups compared with the 44/Hct and 37/Hct groups; and both areas were less in the 9/Hct group compared with the other five groups (p < 0.05). For the hemisphere contralateral to occlusion, there was a direct correlation between hematocrit and oxygen delivery. However, for the hemisphere ipsilateral to occlusion, oxygen delivery increased as hematocrit decreased (44/Hct, 8.6 +/- 0.3 vs. 9/Hct, 13.6 +/- 0.4 [mean +/- SD, ml 100 g-1 min-1]). The results of this study support a hypothesis that hemodilution with DCLHb decreases the extent of focal cerebral ischemia.

The effects of alpha-alpha cross-linked hemoglobin on the feeding and locomotor activity of rats.

The feeding and locomotor activities of rats were used as an assay for the potentially toxic effects of an oxygen-carrying blood substitute. Rats lived in individual cages where they could feed ad lib by pressing a lever once for each small food pellet, drink water, or run in a wheel; a 12-h light/dark cycle was continuously in effect. After being anesthetized and hemorrhaged one-third of their total blood volume, individual rats were resuscitated with one of the following fluids: their own shed blood (OB), bis(3,5-dibromosalicylfumarate) alpha-alpha cross-linked hemoglobin (HbXL), human serum albumin (HSA), or Ringer's lactate (RL). Rats in a fifth group were not resuscitated (NR). During the dark period on the day of hemorrhage, the food intake and running activity of rats in all groups decreased. Food intake and locomotor activity of rats in the HbXL, NR and OB groups were more suppressed than the HSA or RL groups. The food intake of rats in the HbXL and NR groups remained significantly more suppressed during the dark period of the first recovery day; running continued to be suppressed in the HbXL group on the first recovery day, but not the second recovery day. In an effort to determine the extent to which the rats in the HbXL group were impaired, an increasing number of lever presses was required for each food pellet beginning with recovery day number 3 for all treatment groups. As the ratio of presses per pellet was increased, food intake decreased and running increased for all groups; no differences between groups were significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Cross-linked hemoglobin solution as a resuscitative fluid after hemorrhage in the rat.

Intramolecularly (alpha-alpha) cross-linked hemoglobin has been reported to have oxygen transport properties similar to those of whole blood. The present study evaluated the efficacy of diaspirin alpha-alpha cross-linked hemoglobin solution as a resuscitation fluid, with heart rate, mean arterial pressure, and transcutaneous oxygen tension as the study parameters. Rats were bled and approximately one third of their total blood volume (20 ml/kg) was removed while they were anesthetized; they were then resuscitated with 14% hemoglobin solution. Animals that received either 10 mg/kg (n = 10) or 20 mg/kg (n = 10) of hemoglobin solution responded quickly and positively to the infusions: mean arterial pressure (which had dropped to less than 40% of prehemorrhage levels) returned to baseline within 2 minutes of initiating infusion; by 4 minutes, the mean arterial pressures of the hemoglobin-infused groups were significantly higher (p less than or equal to 0.05) than those in both the autologous shed blood (n = 8) and lactated Ringer's (n = 10) groups. The heart rate and transcutaneous oxygen tension responses in both the half-volume and full-volume replacement hemoglobin groups matched the response to autologous shed blood throughout the hour of observation. The favorable hemodynamic response to infusion of cross-linked hemoglobin solution after hemorrhage suggests that this material is comparable to autologous shed blood and superior to lactated Ringer's solution as a resuscitative fluid as assessed in this model.

Rat maze performance after resuscitation with cross-linked hemoglobin solution.

Unmodified stroma-free hemoglobin has been found to produce neurotoxicity and behavioral impairment in rats. In contrast, a recent assessment of a modified (diaspirin alpha-alpha cross-linked) hemoglobin (HbXL) solution found normal memory, learning, and brain histology after infusion of a clinically relevant dose of a 14% HbXL solution. The current study examined this potential resuscitation fluid for evidence of neurobehavioral toxicity under clinical conditions. Rats were trained to complete a water alley maze, had 50% of their total blood volume (30 ml/kg) withdrawn, were resuscitated with 14% HbXL solution (45 ml/kg), Ringer's lactate (60 ml/kg), or autologous shed blood, and were subsequently retested in the water maze. Rats resuscitated with HbXL or autologous shed blood survived resuscitation, while 20% of those resuscitated with Ringer's lactate died during treatment. No significant performance degradation was observed in the HbXL rats following resuscitation, and no brain pathology was observed at necropsy 10 days after treatment. Ischemic brain lesions were observed in three (25%) of the surviving rats resuscitated with Ringer's lactate solution. Renal tubule regeneration indicative of an earlier insult was observed in animals from all three groups. A significant correlation between the total pathology in the five organs examined and maze errors was observed (p less than 0.001). The survival, maze performance, and histology results suggest that resuscitation with 14% HbXL solution does not cause neurotoxicity, as assessed in this lethal hemorrhage model.

Rat maze performance after infusion of cross-linked hemoglobin solution.

Neurotoxicity and behavioral performance degradation have previously been observed in rats after exchange transfusions with unmodified stroma-free hemoglobin solutions. We evaluated a diaspirin cross-linked stroma-free hemoglobin solution (HbXL) for evidence of neurotoxicity. Rats that were trained to complete a water alley maze received a clinically-relevant dose (20 ml/kg) of the 14% HbXL solution on top of their normal blood volume. After post-treatment memory testing in the water maze, the same rats were challenged to learn an elevated radial-arm maze. The HbXL and control groups showed no water maze performance degradation after treatment, and all groups demonstrated learning of the radial-arm maze as shown by decreased errors and times to completion. The brains, heart, and livers presented normal histology thirty days after infusion, but six of fifteen animals showed marked renal tubular regeneration. The normal memory and learning performance and brain histology after infusion with HbXL suggests that this hemoglobin solution is not neurotoxic to unhemorrhaged rats.

Karyotype analysis of a frog pronephric tumor cell line.

Pronephric tumor cell lines, established from explants of a herpes virus induced frog renal adenocarcinoma, were shown to have a aneuploid modal chromosome number of 39. A karyotypic analysis of one line demonstrated the presence of abnormal chromosomes and chromosomal aberrations not previously reported for Lucké tumor cells. The cell line was characterized by two marker chromosomes of high incidence, but there was no evidence of a stemline population of tumor cells.