Haemostatic resuscitation in practice: a descriptive analysis of blood products administered during Operation HERRICK, Afghanistan

INTRODUCTION

Life-threatening haemorrhage is the leading cause of potentially survivable injury in battlefield casualties. During Operation HERRICK (Afghanistan), mortality rates improved year on year due to a number of advances in trauma care, including haemostatic resuscitation. Blood transfusion practice has not previously been reported in detail during this period.

METHODS

A retrospective analysis of blood transfusion at the UK role 3 medical treatment facility (MTF) at Camp Bastion between March 2006 and September 2014 was performed. Data were extracted from two sources: the UK Joint Theatre Trauma Registry (JTTR) and the newly established Deployed Blood Transfusion Database (DBTD).

RESULTS

3840 casualties were transfused 72 138 units of blood and blood products. 2709 adult casualties (71%) were fully linked with JTTR data and were transfused a total of 59 842 units. Casualties received between 1 unit and 264 units of blood product with a median of 13 units per patient. Casualties wounded by explosion required almost twice the volume of blood product transfusion as those wounded by small arms fire or in a motor vehicle collision (18 units, 9 units, and 10 units, respectively). More than half of blood products were transfused within the first 2 hours following arrival at the MTF. There was a trend towards balanced resuscitation with more equal ratios of blood and blood products being used over time.

CONCLUSION

This study has defined the epidemiology of blood transfusion practice during Operation HERRICK. The DBTD is the largest combined trauma database of its kind. It will ensure that lessons learnt during this period are defined and not forgotten; it should also allow further research questions to be answered in this important area of resuscitation practice.

Drug design for ever, from hype to hope

In its first 25 years JCAMD has been disseminating a large number of techniques aimed at finding better medicines faster. These include genetic algorithms, COMFA, QSAR, structure based techniques, homology modelling, high throughput screening, combichem, and dozens more that were a hype in their time and that now are just a useful addition to the drug-designers toolbox. Despite massive efforts throughout academic and industrial drug design research departments, the number of FDA-approved new molecular entities per year stagnates, and the pharmaceutical industry is reorganising accordingly. The recent spate of industrial consolidations and the concomitant move towards outsourcing of research activities requires better integration of all activities along the chain from bench to bedside. The next 25 years will undoubtedly show a series of translational science activities that are aimed at a better communication between all parties involved, from quantum chemistry to bedside and from academia to industry. This will above all include understanding the underlying biological problem and optimal use of all available data.

Energetic and kinematic consequences of weighting the distal limb

REASON FOR PERFORMING STUDY

It is well known that adding a load to a horse's back increases its energetic costs of locomotion, but the magnitude of increase obtained by loading the most distal portion of limb has not been measured.

OBJECTIVES

To measure oxygen consumption in horses with mass added to the back and hooves. Because such mass distribution alters inertial parameters of the limbs, kinematic measurements were made to quantify the magnitude of change in limb movement.

METHODS

Steady-state oxygen consumption was measured in 6 horses with a load of 2.4 kg. The load was either carried on the back or distributed equally between the 4 limbs. Modified bell boots kept the mass at the level of P3. Horses trotted on a treadmill at speeds ranging from 2 to 5 m/sec (in 0.5 m/sec increments). High-speed (250 Hz) digital images were recorded in a sagittal plane and the positions of retroreflective markers located on standard positions on the limbs were digitised for kinematic analysis.

RESULTS

Loading of the distal limbs produced a 6.7% increase in metabolic rate, an order of magnitude higher than when the mass was added over the back. Although the stride period was 2% longer in horses with loads on the distal limbs, time of contact and duty factor were not different. Distal limb loading increased the range of motion in hind- but not forelimbs.

CONCLUSIONS

The costs of swinging the limbs in the horse are considerable and the addition of weights to the distal limb can have a profound effect on not only the energetics of locomotion but also the kinematics, at least in the hindlimb.

POTENTIAL RELEVANCE

The use of weighted shoes, intended to increase animation of the gait, increases the metabolic effort of performance horses a disproportionate amount. The additional mass also increases the joint range of motion and, potentially, the likelihood of injury.

Nebulized nitric oxide/nucleophile adduct reduces pulmonary vascular resistance in mechanically ventilated septicemic sheep*

OBJECTIVE

To study the effects of a novel, intermittently administered, aerosolized nitric oxide donor, methyl-N-2-dimethylaminoethyl-3-aminoproprionid/nitric oxide (DMDE-NO), on pulmonary hemodynamic responses to sepsis.

DESIGN

Prospective, randomized, controlled study in awake sheep.

SETTING

Investigational intensive care unit of a university medical center.

SUBJECTS

Thirteen instrumented merino ewes weighing 36 +/- 0.9 kg underwent a hemodynamic study 1 wk postoperatively.

INTERVENTIONS

On the day of the experiment, the sheep received a tracheotomy and mechanical ventilation was subsequently started. Pseudomonas aeruginosa bacteria were infused intravenously, beginning at time 0 hrs and continuing throughout the 48-hr experiment. The animals were randomly assigned to receive nebulized DMDE-NO 1 mg/kg, dissolved in 8 mL of saline (DMDE-NO group, n = 7), or nebulized saline alone (control group, n = 6) delivered by a nebulizer. The nebulizations started at 2, 6, 20, 24, and 43 hrs after the baseline, each time lasting for 1 hr.

MEASUREMENTS AND MAIN RESULTS

Inhaled aerosolized DMDE-NO reversibly reduced the sepsis-induced increase in pulmonary artery pressure by 13-17% and pulmonary vascular resistance index by 21-31% compared with the values registered before the administration of the drug. Systemic hemodynamics underwent an early hypodynamic phase followed by a gradual increase in cardiac index and a decrease in both mean arterial pressure and systemic vascular resistance index, but with no significant difference between groups. Gas exchange variables and plasma nitrite/nitrate did not differ significantly between groups either.

CONCLUSIONS

In sheep, inhaled nebulized DMDE-NO reduces sepsis-induced changes in pulmonary hemodynamics with no change in systemic hemodynamics or gas exchange.

Inhibition of neuronal nitric oxide synthase by 7-nitroindazole attenuates acute lung injury in an ovine model

Nitric oxide (NO) has been shown to play a major role in acute lung injury (ALI) after smoke inhalation. In the present study, we developed an ovine sepsis model, created by exposing sheep to smoke inhalation followed by instillation of bacteria into the airway, that mimics human sepsis and pneumonia. We hypothesized that the inhibition of neuronal NO synthase (nNOS) might be beneficial in treating ALI associated with this model. Female sheep (n = 26) were surgically prepared for the study and given a tracheostomy. This was followed by insufflation of 48 breaths of cotton smoke (40 degrees C) into the airway of each animal and subsequent instillation of live Pseudomonas aeruginosa [5 x 10(11) colony forming units (CFU)] into each sheep's lung. All sheep were mechanically ventilated using 100% O2. Continuous infusion of 7-nitroindazole (7-NI), an nNOS inhibitor, NG-monomethyl-l-arginine (l-NMMA), a nonspecific NOS inhibitor, or aminoguanidine (AG), an inducible NOS inhibitor, was started 1 h after insult. The administration of 7-NI improved pulmonary gas exchange (PaO2/FiO2; where PaO2 is arterial PO2 and FiO2 is fractional inspired oxygen concentration) and pulmonary shunt fraction and attenuated the increase in lung wet-to-dry weight ratio seen in the nontreated sheep. Histologically, 7-NI prevented airway obstruction. The increase in airway blood flow after injury in the nontreated group was significantly inhibited by 7-NI. The increase in plasma concentration of nitrate and nitrite (NOx) was inhibited by 7-NI as well. Posttreatment with l-NMMA improved the pulmonary gas exchange, but AG did not. The results of the present study show that nNOS may be involved in the pathogenesis of ALI after smoke inhalation injury followed by bacterial instillation in the airway.

Recombinant antithrombin attenuates pulmonary inflammation following smoke inhalation and pneumonia in sheep

OBJECTIVE

The interaction between coagulation and inflammation has become one of the major topics in critical care medicine. In the present study, we investigated the effect of posttreatment of sepsis with recombinant human antithrombin.

DESIGN

Experimental laboratory in a university hospital.

SETTING

University laboratory.

SUBJECTS

Female merino ewes (n = 16).

INTERVENTIONS

After 1 wk of recovery from the surgical preparation, a tracheotomy was performed followed by insufflation of 48 breaths of cotton smoke (<40 degrees C). Afterward, a stock solution of live (5 x 10(11) colony-forming units) was instilled in the both lung lobes through a bronchoscope. All sheep were mechanically ventilated employing 100% oxygen. An infusion of recombinant human antithrombin (100 units x kg(-1) x 24 hrs(-1), intravenously; n = 6) or saline (n = 6) was started 1 hr after injury. Sham control animals (n = 4) were surgically prepared but not insufflated with smoke and bacteria. Lung histologic changes were evaluated by a scoring system.

MEASUREMENTS AND MAIN RESULTS

The infusion of recombinant human antithrombin maintained the baseline antithrombin activity throughout the study; in the saline-treated group, antithrombin activity decreased significantly. The lung wet/dry weight ratio and the histology score (combined scores for congestion, edema, inflammation, and hemorrhage) were significantly increased by the insult, but recombinant human antithrombin attenuated these responses. More than 30% of both bronchi and bronchioles were obstructed by cast formation after smoke inhalation and pneumonia. The cast was composed of epithelial cells, neutrophils, mucus, and fibrin. The obstruction was significantly improved by recombinant human antithrombin infusion. Arterial pressure and urine output were also attenuated in recombinant human antithrombin-treated animals. The increases in plasma nitrate/nitrite concentrations and pulmonary shunt fraction after the injury were not attenuated by recombinant human antithrombin.

CONCLUSION

Posttreatment by recombinant human antithrombin was effective in treating acute lung injury after smoke inhalation and pneumonia in sheep. We hypothesize that the decrease in antithrombin activity during sepsis might induce severe airway obstruction and that supplementation with antithrombin inhibits this decrease.

Heparin nebulization attenuates acute lung injury in sepsis following smoke inhalation in sheep

Pseudomonas pneumonia is a common complication of smoke inhalation injury. Airway casts formed from clotted mucous occur frequently in this condition. A recent report shows that intravenous heparin improves oxygenation and reduces lung damage in a sheep model of smoke inhalation. We hypothesized that nebulized heparin could be an effective means of reducing cast formation. Female sheep (n = 19) were surgically prepared for a study of acute lung injury (ALI). After a tracheotomy, 48 breaths of cotton smoke (<40 degrees C) were inflated into the airway. Afterwards, live Pseudomonas aeruginosa (5 x 10(11) CFU) was instilled into the lung. All sheep were mechanically ventilated with 100% O2 and were divided into four groups: a heparin-nebulized group (n = 5; animals received aerosolized heparin [10,000 I.U.] 1 h after the bacterial instillation and subsequently every 4 h thereafter), an intravenous heparin group (n = 5,300 U/kg/23 h, infusion was started 1 h after the injury), a saline-nebulization group (n = 5; animals received inhaled nebulized saline), and a sham injury group (n = 4, treated in the same fashion, but no injury). The animals were sacrificed after 24 h of mechanical ventilation, and lung samples were harvested. Sheep exposed to lung injury presented with typical hyperdynamic cardiovascular changes and a corresponding drop in PaO2. These changes were significantly attenuated in the heparin groups. Histological changes consisting of cellular infiltrates, lung edema, congestion, and cast formation were reduced by heparin. These data suggest that nebulized inhaled heparin is a beneficial therapy for sepsis-induced ALI.

A novel animal model of sepsis after acute lung injury in sheep

OBJECTIVE

Patients with acute lung injury after smoke inhalation often develop pneumonia subsequently complicated by sepsis. This often is a fatal complication. The aim of this study was to develop a standardized and reproducible model of hyperdynamic sepsis after smoke inhalation in sheep.

DESIGN

Prospective, experimental study in sheep.

SETTINGS

Experimental laboratory in a university hospital.

SUBJECTS

Twenty-one female Merino ewes.

INTERVENTION

Animals were anesthetized and surgically prepared for this chronic study. After a week of recovery, baseline data were collected. After tracheostomy was performed, sheep were connected to a volume-controlled ventilator. Acute lung injury was produced by insufflating the lungs with 48 breaths of cotton smoke. During halothane anesthesia, live bacteria suspended in a 30-mL saline solution containing 2-5 x 10(11) colony-forming units were instilled through a bronchoscope into the right lower and middle lung lobes (10 mL each) and left lower lung lobe (10 mL; n = 10). Eleven sheep were given smoke but not bacteria. After injury and the bacterial challenge, the animals were ventilated mechanically with 100% oxygen. The animals were monitored for 48 hrs. was detected in blood cultures after 14-48 hrs.

MEASUREMENTS AND MAIN RESULTS

The sheep developed a hyperkinetic cardiovascular response concomitant with a decrease in Pao similar to severe sepsis in human patients who meet the criteria for acute respiratory distress syndrome (PaO2 /FIO2 <200). These changes were more severe than in animals exposed to smoke inhalation alone. Mean arterial pressures at 48 hrs in the smoke-alone and the smoke + sepsis group were 85.5 +/- 5.2 and 68.1 +/- 7.6 mm Hg, respectively (mean +/- se, p<.05).

CONCLUSION

This animal model closely resembles hyperdynamic sepsis in humans and may be of great value for studies of sepsis with smoke inhalation.

The cost of transport in an extended trot

We hypothesised that trotters during an extended trot have lower energetic costs of locomotion (CT) than horses not bred for this behaviour. VO2 was measured as a function of speed in 7 Arabian horses (3 trained to extend their trotting speeds) and in 2 horses, of similar mass, bred to trot (Hackney). Both oxygen consumption and CT increased with speed and there was, contrary to our hypothesis, no difference between breeds. In Arabians at 6.5 m/s, CT had increased 25% above the CT at 5.0 m/s (normal transition speed). For Hackneys at 6.8 m/s, the CT was almost 35% higher. Stride frequencies increased linearly in all horses up to 5.0 m/s. At the canter at 5.0 m/s, the frequency increased 9% to 111 strides/min, but then increased minimally with speed. In the Hackneys and the Arabians that extended the trot, stride frequencies were approximately 102 and did not increase with speed. Stride length (SL) increased linearly with speed in both trotting and cantering horses, and cantering SL were lower than trotting (at 5.0 m/s, SL for trotting = 3.04 m and for cantering SL = 2.68 m). There were no differences between breeds in stride frequency or stride length. Extending the trot can have profound energetic requirements that could limit athletic performance and may lead to increased concussive impact on the limbs.

Theoretical frameworks for understanding and investigating the therapeutic relationship in psychiatry

BACKGROUND

Mental health care is delivered through a relationship between a clinician and a patient. Although this therapeutic relationship is of central importance for mental health care, it appears to be relatively neglected in psychiatric research. Empirical research has for the most part adopted concepts and methods developed in psychotherapy and general medical practice. Hence, unpacking the presuppositions that have informed research on the therapeutic relationship to date may be a useful first step in developing this field.

METHOD

A review of the literature was carried out.

RESULTS

Six central theories are identified as framing the definitions and methods on this topic: role theory, psychoanalysis, social constructionism, systems theory, social psychology and cognitive behaviourism. To date, role theory, psychoanalysis and systems theory appear to be the frameworks most often applied in research in this field. Each perspective offers a unique emphasis in the analysis of the therapeutic relationship, which is reflected in the empirical work from each perspective discussed herein.

CONCLUSIONS

None of the theories identified have been fully specified and comprehensively investigated in psychiatric settings. However, more than one approach may be used for thinking about relationships, depending on the treatment situation. Further specification and testing of the theories in psychiatric practice--taking account of the specific context--is warranted to underpin more pragmatic research. A stronger link between fundamental psychological and sociological research and applied health care research would advance our understanding of which elements of positive therapeutic relationships are instrumental in improving patient outcome and ultimately contribute to improving mental health care.

Design and synthesis of a maximally diverse and druglike screening library using REM resin methodology

A 3042 compound screening library was synthesized using a combination of two solid-phase technologies: REM resin methodology and Lewis acid promoted aminolysis. The exclusivity and structural diversity of the library were enhanced by using a highly divergent synthetic strategy involving 13 different scaffolds (9 of which were custom-made), five different types of resin-bound phenol derivatization chemistry (Mitsunobu, Suzuki, acylation, sulfonylation, and carbamoylation), and three different cleavage strategies (Hofmann elimination, AlCl(3)-promoted aminolysis, base-promoted esterolysis). This is the first example of a solid-phase Suzuki coupling involving a resin-bound aryl triflate being used for library synthesis. Computational analysis suggested that the compounds are likely to have favorable properties for CNS penetration. Analysis of the library by HPLC and MS suggested at least 90% of the sampled members were present in an average purity of approximately 70%. Encouragingly, hits have been identified from high-throughput screening of this library, such as compound 6, which has an affinity of 1.02 microM for the GlyT(2) transporter.

Alpha-amino acid phenolic ester derivatives: novel water-soluble general anesthetic agents which allosterically modulate GABA(A) receptors

In the search for a novel water-soluble general anesthetic agent the activity of an alpha-amino acid phenolic ester lead, identified from patent literature, was markedly improved. In addition to improving in vivo activity in mice, good in vitro activity at GABA(A) receptors was also conferred. Within the series of compounds good enantioselectivity for both in vitro and in vivo activity was found, supporting a protein-mediated mechanism of action for anesthesia involving allosteric modulation of GABA(A) receptors. alpha-Amino acid phenolic ester 19, as the hydrobromide salt Org 25435, was selected for clinical evaluation since it retained the best overall anesthetic profile coupled with improved stability and water solubility. In the clinic it proved to be an effective intravenous anesthetic in man with rapid onset of and recovery from anesthesia at doses of 3 and 4 mg/kg.

Decontamination issues for chemical and biological warfare agents: how clean is clean enough?

The objective of this assessment is to determine what level of cleanup will be required to meet regulatory and stakeholder needs in the case of a chemical and/or biological incident at a civilian facility. A literature review for selected, potential chemical and biological warfare agents shows that dose information is often lacking or controversial. Environmental regulatory limits or other industrial health guidelines that could be used to help establish cleanup concentration levels for such agents are generally unavailable or not applicable for a public setting. Although dose information, cleanup criteria, and decontamination protocols all present challenges to effective planning, several decontamination approaches are available. Such approaches should be combined with risk-informed decision making to establish reasonable cleanup goals for protecting health, property, and resources. Key issues during a risk assessment are to determine exactly what constitutes a safety hazard and whether decontamination is necessary or not for a particular scenario. An important conclusion is that cleanup criteria are site dependent and stakeholder specific. The results of a modeling exercise for two outdoor scenarios are presented to reinforce this conclusion. Public perception of risk to health, public acceptance of recommendations based on scientific criteria, political support, time constraints, and economic concerns must all be addressed in the context of a specific scenario to yield effective and acceptable decontamination.

Non-depolarizing neuromuscular blocking activity of bisquaternary amino di- and tripeptide derivatives

Herein we describe the synthesis of novel di- and tripeptide derivatives with two quaternary nitrogen groups attached and the biological testing of these compounds for neuromuscular blocking (NMB) activity in vitro and in vivo. The short peptide scaffold was selected because it offers potential for desired distance between the two pharmacophoric quaternary nitrogen groups, short duration of action, straightforward synthesis, and compatibility with an injectable formulation. From a small series of compounds 20c,e are identified as effective non-depolarizing NMB agents in vitro and in vivo in anesthetized cats and Rhesus monkeys with potencies similar to those of the clinical reference compounds rocuronium (4) and suxamethonium (2) (monkey ED(90) = 0.68, 0.23, 0.16, 5.04 micromol/kg, respectively). These new peptide derivatives 20c,e have similar potency and onset time but longer duration and slower recovery than the clinically used reference compounds. The structure-activity relationships described for this chemical series lead to the conclusion that the di- or tripeptide fragment can be regarded as an alternative template to the steroid or aliphatic ester of previously reported NMBs and within this tripeptide-derived series clog P correlates well with in vitro NMB activity.

Conformationally constrained anesthetic steroids that modulate GABA(A) receptors

Various cyclic ether and other 3 alpha-hydroxyandrostane derivatives bearing a conformationally constrained hydrogen-bonding moiety were prepared. Their anesthetic potency and their binding affinity for GABA(A) receptors, measured by intravenous administration to mice and inhibition of [(35)S]TBPS binding to rat whole brain membranes, were compared with that of known anesthetic 3 alpha-hydroxypregnan-20-ones. Synthetic steroids with similar in vitro and in vivo activities to the endogenous 3 alpha-hydroxypregnan-20-ones all had an ether oxygen on the beta-face of the steroid D-ring. These results suggest that for optimal GABA(A) receptor modulation, the hydrogen bond-accepting substituent should be near perpendicular to the plane of the D-ring on the beta-face of the steroid.

The effect of inducible nitric oxide synthase (iNOS) inhibition on smoke inhalation injury in sheep

Recent studies on smoke inhalation injury have been focused on nitric oxide (NO) as an essential factor of progressive lung injury. We studied the effects of inducible nitric oxide synthase (iNOS) inhibition on inhalation injury in sheep. Sheep (n = 14) were prepared surgically for chronic study. After recovery period, the sheep received 48 breaths of cotton smoke. The animals were then randomised into two groups: MEG group [30 mg/kg mercaptoethylguanidine (MEG), selective inhibitor of iNOS and peroxynitrite scavenger, was given 1 h after injury and then 8 h for 41 h, n = 7] and control group (0.9% NaCl, n = 7). All animals were ventilated mechanically, and airway blood flow was measured using colored microspheres. In the control group, following significant increase in airway blood flow, deterioration in the PaO2/FiO2 ratio was observed. Whereas in the MEG group, it was not observed. In addition, the MEG group did not show significant increase in pulmonary vascular resistance and intrapulmonary shunt fraction. Lung wet/dry ratios, a marker of pulmonary edema, were significantly lower in the MEG group. At 48 h after injury, lung tissue-conjugated dienes, an index of lung oxidative tissue injury, were significantly lower in the MEG group than in the control group. Our data suggest that 1) iNOS-NO produced in the airway circulation plays a major role on the significant increase in airway blood flow, which may contribute to the spread of injury from injured airway to the lung parenchyma; 2) iNOS-NO induced in the pulmonary circulation contributes to the loss of hypoxic pulmonary vasoconstriction; and 3) iNOS-NO plays an important role on the lung oxidative tissue injury.

Noradrenaline and nomega-monomethyl-L-arginine (L-NMMA): effects on haemodynamics and regional blood flow in healthy and septic sheep

This prospective, non-randomized, controlled experimental study looks at the effects of N(omega)-monomethyl-L-arginine (L-NMMA) on haemodynamics, oxygen transport and regional blood flow in healthy and septic sheep, and compares these effects with those of noradrenaline (NA; norepinephrine). All sheep were chronically instrumented. Six sheep received L-NMMA (7 mg.kg(-1).h(-1)), six sheep received NA, and seven sheep received the carrier alone (0.9% NaCl). The NA dosage was continuously and individually adjusted to achieve the same increase in blood pressure as observed in matched sheep of the L-NMMA group (non-septic phase). Treatment was discontinued after 3 h. Sepsis was initiated and maintained by a continuous infusion of live Pseudomonas aeruginosa. After 24 h of sepsis, the sheep were again challenged over a treatment period of 3 h with their previously assigned drug (septic phase). During the non-septic phase of the experiment, NA and L-NMMA both caused an increase in mean arterial pressure (MAP) through vasoconstriction. Ater 24 h of sepsis, all sheep developed a hyperdynamic circulatory state. While L-NMMA caused an increase in MAP through intense vasoconstriction, NA caused MAP to increase through a further elevation of the cardiac index. The NA dosage needed was significantly higher in the septic phase compared with the non-septic phase, reflecting a reduced vascular responsiveness to catecholamines during sepsis. Renal blood flow remained unchanged during either treatment in both the non-septic and the septic phases. Nevertheless, urine output increased during NA treatment in both the non-septic and the septic phases, while L-NMMA caused urine output to increase only under septic conditions.

Selective inhibition of inducible nitric oxide synthase: effects on hemodynamics and regional blood flow in healthy and septic sheep

OBJECTIVES

To investigate the effects of S-ethylisothiourea (S-EITU) on hemodynamics, oxygen transport, and regional blood flow in healthy and septic sheep.

DESIGN

Prospective, randomized, controlled experimental study with repeated measures.

SETTING

Investigational intensive care unit at a university medical center.

SUBJECTS

Eleven healthy, female adult sheep of the Merino breed, divided into a control group (n = 5) and into a group treated with S-EITU (n = 6).

INTERVENTIONS

All sheep were chronically instrumented. After a 5-day recovery period, they were randomly assigned to either control or S-EITU groups. While control sheep received only saline, S-EITU was administered in increasing doses of 1, 3, and 9 mg/kg/hr over 1 hr each (nonseptic phase). After 2 days of recovery, a continuous infusion of live Pseudomonas aeruginosa (2.5 x 106 colony-forming units/min) was started in all sheep and maintained for the remainder of the experiment. After 24 hrs of sepsis, the sheep again received their assigned treatment (septic phase). In both the nonseptic and septic phases, the sheep received colored microspheres through a left atrial catheter to allow analysis of regional blood flows. All animals were autopsied at the end of the experiments, and organ probes were removed for blood flow analyses.

MEASUREMENTS AND MAIN RESULTS

The administration of S-EITU caused a dose-dependent vasoconstriction in the nonseptic phase. After 24 hrs of Pseudomonas infusion, all sheep developed a hyperdynamic circulatory state, with increased cardiac indices and reduced arterial pressures and systemic vascular resistances. Oxygen extraction decreased significantly, preventing an increase in oxygen consumption, despite an increased oxygen delivery. The hyperdynamic circulation was dose dependently reversed by S-EITU, causing an increase in arterial pressure by peripheral vasoconstriction. Sheep in the control group showed a continuation of the hyperdynamic circulation. The effects of S-EITU on hemodynamics and regional blood flows were comparable under septic and nonseptic conditions.

CONCLUSIONS

With the inducible form of nitric oxide synthase expressed under septic, but not under nonseptic conditions, S-EITU was expected to have vasoconstrictive properties only in the septic phase. It produced a comparable vasoconstriction during the nonseptic phase of the experiment. Thus, either S-EITU does not selectively block the inducible nitric oxide synthase in sheep, or other vasodilators besides nitric oxide play an important role in septic vasodilation.

Continuous infusion of pyridoxalated hemoglobin polyoxyethylene conjugate in hyperdynamic septic sheep

Cell-free hemoglobin solutions can scavenge nitric oxide and therefore increase mean arterial pressure (MAP). The present study investigated the effects of a continuous low-dose infusion of modified hemoglobin during ovine hyperdynamic sepsis. 13 sheep received a continuous infusion of live Pseudomonas aeruginosa bacteria for 48 h. Animals that survived the first 24 h of sepsis (n=12) were randomly assigned either to a treatment group that received 20 mg x kg(-1) x h(-1) pyridoxalated hemoglobin polyoxyethylene conjugate (PHP) for 20 h or to a control group that received the same volume of the vehicle for 20 h. MAP increased in the treatment group during 4 h of PHP infusion 12.7+/-1.7 mmHg (p < .05) and after 20 h of PHP infusion MAP was still 12.4+/-2.1 mmHg above the MAP before starting PHP (p < .05). MAP in the control group did not change significantly from 24 h to 48 h of sepsis. No differences in regional blood flow were seen between groups. Bacterial counts in the spleen and kidney were lower in the treatment group than in the control group. Continuous low-dose infusion of PHP can normalize systemic vascular resistance and MAP for long periods without deterioration of regional blood flow or bacterial clearance.

Pyridoxalated hemoglobin polyoxyethylene conjugate reverses hyperdynamic circulation in septic sheep

We investigated the effects of modified hemoglobin on regional blood flow and function of different organs during hyperdynamic sepsis. Fourteen sheep were surgically prepared for the study. After a 5-day recovery period, a continuous infusion of live Pseudomonas aeruginosa bacteria was begun and maintained for 48 h. At 24 h, after a hyperdynamic circulation had developed, the animals were randomly assigned to two groups: 1) a treatment group (n = 7) that received an infusion with 100 mg/kg pyridoxalated hemoglobin polyoxyethylene conjugate (PHP) over 30 min and 2) a control group (n = 7) that received only the vehicle. PHP infusion increased mean arterial pressure from 86 +/- 2.8 to 101.8 +/- 3.5 mmHg (P < 0.05) and systemic vascular resistance index from 769 +/- 42.1 to 1,087 +/- 56.8 dyn . s . m2 . cm-5 (P < 0.05). PHP infusion did not decrease regional blood flow, measured with fluorescent microspheres, below the baseline values in any of the analyzed tissues. None of the investigated blood chemistry variables showed any changes indicative of impaired organ function after PHP infusion. In our model of ovine sepsis we found no side effects after PHP infusion that would limit the use of PHP as a nitric oxide scavenger in sepsis.

Nitric oxide synthase inhibition restores hypoxic pulmonary vasoconstriction in sepsis

Hypoxic pulmonary vasoconstriction (HPV) is inhibited by inhaled nitric oxide (NO) in healthy animals and is blunted in endotoxemia. We investigated whether the loss of HPV during sepsis could be reversed by NO synthase (NOS) inhibition. Hypoxic challenges were induced in intubated, awake sheep breathing 100% nitrogen to the left lung and 100% oxygen to the right lung. HPV was assessed as the decrease in left pulmonary blood flow during hypoxia, measured with an ultrasonic flow probe around the left pulmonary artery. Group I (n = 5) received carrier solutions and Groups II (n = 6) and III (n = 8) received an infusion containing Pseudomonas aeruginosa. After 24 h, Group III also received an infusion of 6.6 mg.kg.h-1 N omega-monomethyl-L-arginine (L-NMMA). After 24 h of sepsis, HPV decreased from 60 +/- 9% in Group II and 56 +/- 4% in Group III to 27 +/- 2% and 26 +/- 4%, respectively. Group I showed no change in HPV. During infusion of L-NMMA, HPV increased to 38 +/- 4%. Pulmonary shunt during hypoxia increased in Group III to 161 +/- 10% of its baseline value, and decreased to 121 +/- 11% during infusion of L-NMMA. We conclude that L-NMMA improves but does not restore HPV, indicating that other vasodilatory mediators besides NO also influence HPV in sepsis.

Effects of alpha-trinositol on systemic inflammation and renal function in ovine bacterial sepsis

Neuronally secreted peptides are important mediators of hemodynamic changes in the systemic inflammatory response. The inositol derivative D-myo-inositol[1,2,6]triphosphate (alpha-trinositol) has been demonstrated to be a specific nonpeptide antagonist of vasoconstriction induced by neuropeptide Y. We induced sepsis by a 48 h continuous infusion of Pseudomonas aeruginosa (10(6) colony-forming unit/min intravenously [i.v.]) in 12 chronically instrumented, conscious sheep. After 24 h, the animals were randomized to receive either alpha-trinositol (i.v. bolus of 2 mg/kg, followed by a continuous infusion of 3.5 mg/kg/h) or the saline carrier. alpha-Trinositol increased the heart rate (108 +/- 4 to 152 +/- 9 beats per minute) and reduced the stroke volume index (65 +/- 5 to 49 +/- 2 mL/beat/m2) but did not change cardiac index. Left ventricular stroke work decreased significantly (80 +/- 9 to 58 +/- 7 g.m/m2). All blood flows except the infrarenal aortic flow were increased after 24 h, but treatment decreased only the flow to the hind limb region. Urine output and fractional sodium excretion significantly increased without osmotic diuretic effects after alpha-trinositol. In treated animals, we found significantly lower leukocyte counts in all organ tissues. We conclude that alpha-trinositol modulates the cardiac performance and the local inflammatory response in tissues, and improves the fluid balance in septic sheep.

Pyridoxalated hemoglobin polyoxyethylene conjugate does not restore hypoxic pulmonary vasoconstriction in ovine sepsis

OBJECTIVES

Hypoxic pulmonary vasoconstriction, a protective mechanism, minimizes perfusion of underventilated lung areas to reduce ventilation-perfusion mismatching. We studied the effects of sepsis on hypoxic pulmonary vasoconstriction and attempted to determine whether hypoxic pulmonary vasoconstriction is influenced by pyridoxalated hemoglobin polyoxyethylene conjugate, a nitric oxide scavenger.

DESIGN

Prospective, randomized, controlled experimental study with repeated measures.

SETTING

Investigational intensive care unit at a university medical center.

SUBJECTS

Nineteen female merino sheep, divided into three groups: group 1, controls (n = 5); group 2, sheep with sepsis (n = 6); and group 3, septic sheep treated with pyridoxalated hemoglobin polyoxyethylene conjugate (n = 8).

INTERVENTIONS

All sheep were instrumented for chronic study. An ultrasonic flow probe was placed around the left pulmonary artery. After a 5-day recovery, a tracheostomy was performed and a double-lumen endotracheal tube was placed. Animals in groups 2 and 3 received a 48-hr infusion of live Pseudomonas aeruginosa (6 x 10(4) colony-forming units/kg/hr). After 24 hrs, sheep in group 3 received pyridoxalated hemoglobin polyoxyethylene conjugate (20 mg/kg/hr) for 16 hrs; sheep in groups 1 and 2 received only the vehicle. Hypoxic pulmonary vasoconstriction was repeatedly tested by unilateral hypoxia of the left lung with 100% nitrogen. Hypoxic pulmonary vasoconstriction was assessed as the change in left pulmonary blood flow.

MEASUREMENTS AND MAIN RESULTS

In the animals in group 1, left pulmonary blood flow decreased by 62 +/- 8 (SEM)% during left lung hypoxia and remained stable during repeated hypoxic challenges throughout the study period. After 24 hrs of sepsis, left pulmonary blood flow decreased from 56 +/- 10% to 26 +/- 2% (group 2) and from 50 +/- 8% to 23 +/- 6% (group 3). In the sheep in group 2, there was no adaptation over time. Pulmonary shunt fraction increased. Pyridoxalated hemoglobin polyoxyethylene conjugate had no effect on hypoxic pulmonary vasoconstriction or pulmonary shunt. The animals receiving the bacterial infusion developed a hyperdynamic circulatory state with hypotension, decreased systemic vascular resistance, and increased cardiac output. Pyridoxalated hemoglobin polyoxyethylene conjugate increased mean arterial pressure and systemic vascular resistance but did not influence cardiac index. Pulmonary arterial pressure was increased during sepsis and increased even further after pyridoxalated hemoglobin polyoxyethylene conjugate administration. Oxygenation and oxygen delivery and uptake were not affected by pyridoxalated hemoglobin polyoxyethylene conjugate.

CONCLUSIONS

Hypoxic pulmonary vasoconstriction is blunted during sepsis and there is no adaptation over time. It is not influenced by pyridoxalated hemoglobin polyoxyethylene conjugate. Pyridoxalated hemoglobin polyoxyethylene conjugate reversed hypotension and, with the exception of an increase in pulmonary arterial pressure, had no adverse effects on hemodynamics or oxygenation.

Oxalated pyridoxalated hemoglobin polyoxyethylene conjugate normalizes the hyperdynamic circulation in septic sheep

OBJECTIVE

Excessive production of nitric oxide significantly contributes to the hyperdynamic state associated with sepsis. The ability of hemoglobin to scavenge nitric oxide may therefore be beneficial in the treatment of sepsis. In this study, we determined the effects of different doses of the modified human pyridoxalated hemoglobin polyoxyethylene conjugate in an ovine model of hyperdynamic sepsis.

DESIGN

Prospective, experimental study.

SETTING

Large animal research laboratory at a university medical center.

INTERVENTIONS

Sheep (n = 23) were surgically prepared for chronic study. After a 5-day recovery period, all animals received a continuous infusion of live Pseudomonas aeruginosa (2.5 x 10(6) colony-forming units/min) for the next 48 hrs. After 24 hrs of sepsis, the animals were divided into four groups: a) six sheep were used as controls and received a bolus of 200-mL vehicle; b) three sheep received a bolus of 50 mg/kg hemoglobin; c) six sheep received 100 mg/kg of hemoglobin; d) six sheep received 200 mg/kg of hemoglobin.

MEASUREMENTS AND MAIN RESULTS

All animals that survived the first 24 hrs of sepsis (n = 21) developed a hyperdynamic circulation. All three doses of hemoglobin reversed this hyperdynamic state by increasing mean arterial pressure and systemic vascular resistance while decreasing cardiac index. Pulmonary arterial pressure increased after hemoglobin infusion. Increased pulmonary arterial pressure did not affect arterial oxygen saturation nor result in the development of pulmonary edema. Infusion of hemoglobin also caused a 30-fold increase in endothelin-1 plasma concentrations and significantly decreased nitrate and nitrite plasma concentrations.

CONCLUSIONS

The infusion of low doses of pyridoxalated hemoglobin polyoxyethylene conjugate in septic sheep reverses the hyperdynamic circulatory state. An increase in pulmonary arterial pressure was the only observed hemodynamic side effect; changes in the structure or function of other organ systems, or their biochemical correlates were not investigated in this study. In addition to a possible nitric oxide scavenging effect, pyridoxalated hemoglobin polyoxyethylene may affect the nitric oxide synthase and endothelin systems.

A cross cultural comparison of French and Dutch disturbed children using the Child Behaviour Checklist (CBCL)

Parents, mostly mothers, of French and Dutch children who had been referred to Mental Health Services, completed the CBCL to indicate the behaviour problems that their children suffered from. The 85 items which had been found in the USA to measure eight types of disturbed behaviour, called the cross-informant syndromes, were studied to see if a similar set of dimensions of disturbed behaviour would underlie the Dutch and French CBCL scores. Seven types of disturbance were found which corresponded to the equivalent cross informant syndromes, but thought problems had no similar sort of disorder amongst the Dutch and French children. It was found that only 43 items were necessary to measure these seven dimensions. It was concluded that despite differences in language, culture and the pattern of mental health services, the CBCL scores could be used to make meaningful clinical comparisons of psychiatric disturbances.

Principal components describing biological activities and molecular diversity of heterocyclic aromatic ring fragments

Ten physicochemical variables have been calculated for each of 100 different aromatic rings. These variables were selected because of their potential involvement in the molecular recognition of drug-receptor binding interactions, and they include size, lipophilicity, dipole magnitude and orientation, HOMO and LUMO energies, and electronic point charges. A total of 59 different aromatic ring systems were studied including monocyclics and [5.5]-, [6.5]- and [6.6]-fused bicyclics. A principal components analysis of b1ese results generated four principal components which account for 84% of the total variance in the data. These principal components provide a quantitative measure of molecular diversity, and their relevance for structure-activity relationships is discussed. The principal components correlate with the in vitro biological activity of heterocyclic aromatic fragments within a series of previously reported HIV-1 reverse transcriptase inhibitors.

Nitric oxide synthase inhibition versus norepinephrine for the treatment of hyperdynamic sepsis in sheep

OBJECTIVES

To investigate the effects of Nomega-mono-methyl-L-arginine (L-NMMA), an inhibitor of nitric oxide synthesis, on hemodynamics, oxygen transport, and regional blood flow in an ovine model of hyperdynamic sepsis and to compare these effects with the responses to norepinephrine.

DESIGN

Prospective, nonrandomized, controlled experimental study with repeated measures.

SETTING

Investigational intensive care unit at a university medical center.

SUBJECTS

Twenty-five female, healthy, adult sheep of the Merino breed, divided into three groups: nine control sheep; eight sheep treated with L-NMMA; and eight sheep treated with norepinephrine.

INTERVENTIONS

All sheep were chronically instrumented. After a 5-day recovery period, a continuous infusion of live Pseudomonas aeruginosa (2.5 x 10(6) colony-forming units/min) was started and maintained for the remainder of the experiment. After 24 hrs of sepsis, eight sheep received L-NMMA (7 mg/kg/hr), eight sheep received norepinephrine, and nine sheep received the vehicle alone (0.9% saline). The norepinephrine dosage was continuously and individually adjusted to achieve the same increase in blood pressure as was observed in a matched sheep of the L-NMMA group.

MEASUREMENTS AND MAIN RESULTS

After 24 hrs of sepsis, all sheep developed a hyperdynamic circulatory state with increased cardiac indices and reduced arterial pressures, and systemic vascular resistances. L-NMMA reversed the hyperdynamic circulation, causing an increase in arterial pressure by peripheral vasoconstriction. Norepinephrine led to an increase in blood pressure by augmenting cardiac indices, leaving the systemic vascular resistance unaffected. The norepinephrine dose needed to keep the blood pressure high had to be continuously increased, reflecting the reduced vascular responsiveness to catecholamines during sepsis. Renal blood flow remained unaffected by all treatment forms. Norepinephrine and L-NMMA led to a dramatic increase in urine production. Blocking the nitric oxide synthase with L-NMMA did not interfere with the host's pulmonary ability to clear bacteria, nor did treatment with norepinephrine.

CONCLUSIONS

Blocking nitric oxide synthase had a marked vasoconstrictive effect. Both norepinephrine and L-NMMA increased arterial pressure without reducing renal blood flow, leading to an improved renal function.

Nitric oxide synthase inhibition versus norepinephrine in ovine sepsis: effects on regional blood flow

Hypotension is a serious problem in septic patients. We investigated regional perfusion in several organs during treatment of hyperdynamic sepsis in sheep. Sepsis was induced and maintained for the entire experiment with a continuous infusion of live Pseudomonas aeruginosa. Treatment with either norepinephrine or the nitric oxide synthase inhibitor L omega-mono-methyl-arginine (L-NMMA) was begun after 24 h of sepsis and continued for 24 h. The norepinephrine dosage was adjusted to achieve the same increase in mean arterial pressure as that obtained by a fixed dose of L-NMMA (7 mg/kg/h). Blood flows were analyzed by the microsphere technique. Both compounds restored blood pressure effectively, but only L-NMMA caused a significant increase in systemic vascular resistance, concomitant with a significant fall in cardiac output. Sepsis caused an increase in myocardial blood flow and a redistribution of blood flow away from the pancreas and the stomach. Renal blood flow was not significantly elevated. During treatment with either compound, renal blood flow remained unchanged, despite a fall in cardiac output in the L-NMMA group. Unchanged renal blood flow combined with the restoration of arterial blood pressure caused a significant increase in urine output. Both L-NMMA and norepinephrine caused a redistribution of blood flow to the colon. Pancreatic blood flow was further reduced by L-NMMA but the oxygen extraction improved simultaneously, so that oxygen availability in the pancreas might have been unchanged. Because ischemic pancreatitis in sepsis is likely to trigger multiorgan failure, further investigations in that area are desirable.

Evaluation of the biomaterial-interface of screw threads in patients having clinical pain

Fixation devices are normally anchored and stabilized with the use of metallic screws. Under normal circumstances, the patient has no adverse response to the fixation device. However, there are some patients that experience a significant amount of pain and the hardware needs to removed. Removal of the hardware, alleviates the pain. The tissues adjacent to the implanted devices were harvested and analyzed histochemically for cellular detail and immunochemically for the presence of PGE2. These tissues were compared with tissues retrieved from nonpainful stable fixation devices that were removed when they no longer were needed for stabilization. The results showed radiographically the presence of osteolysis in the area of the screw thread in patients with clinical pain. Also, histologically there was a presence of synovial-like granuloma tissue possibly produced by the micromotion of the loosened screw. When the tissues were analysed qualitatively by ELISA for PGE2 they had a statistically significant amount in comparison with tissue retrieved from patients with no clinical pain. The presence of PGE2 in the tissues suggest that this inflammatory mediator is produced in tissues adjacent to unstable devices and may mediate the osteolysis associated with the late implant failure and clinical pain.

Changes in regional hemodynamics after nitric oxide inhibition during ovine bacteremia

We studied the action of nitric oxide synthase (NOS) inhibition on changes in regional blood flow during a continuous infusion of live bacteria. Eighteen ewes were chronically instrumented. After a 7-day recovery period, an infusion of 10(6) colony-forming units/min Pseudomonas aeruginosa was begun. At 24 h, cardiac output increased significantly above baseline in all groups (5.9 +/- 0.4 vs. 8.2 +/- 0.6 l.min 1.m-2), systemic vascular resistance decreased (1,362 +/- 120 vs. 821 +/- 145 dyn.g.cm-5.m-2), and cerebral, cephalic mesenteric, and hindlimb blood flows increased. The animals were then equally and randomly assigned to a bolus of a NOS inhibitor, either 25 mg/kg N omega-nitro-L-arginine methyl ester (L-NAME) or 20 mg/kg N omega-monomethyl-L-arginine (L-NMMA), followed by a continuous infusion of 7 mg.kg-1.min-1 L-NMMA or saline. After NOS inhibition, cardiac index decreased [5.6 +/- 0.1 (L-NAME) and 5.5 +/- 0.4 l.min-1.m-2 (L-NMMA)] and remained significantly decreased for 12 h. 1-NAME decreased carotid and mesenteric blood flows to 64% of the preseptic baseline, and they remained below baseline for 20 h. L-NMMA decreased blood flows only to preseptic baseline values. NOS inhibitors may affect blood flows independently of their hemodynamic effects.

S-ethylisothiourea, a nonamino acid inhibitor of nitric oxide synthase, reverses septic vasodilation in sheep

S-ethylisothiourea (3936W92) is a nonamino acid antagonist of nitric oxide synthase. Its selectivity for the inducible form of nitric oxide synthase is twice as high as for the constitutive form of the enzyme. We tested 3936W92 in 20 sheep, which were surgically prepared for chronic study. In all sheep, a hyperdynamic sepsis was induced by a continuous infusion of live Pseudomonas aeruginosa. After 24 h of sepsis, nine sheep received a continuous infusion of 3936W92 over the next 24 h, whereas the control group (n = 9) received saline instead. Two sheep died within the first 24 h of sepsis. 3936W92 caused a complete reversal of the hyperdynamic circulation, while sheep in the control group remained hyperdynamic. Although the cardiac index decreased significantly during treatment with 3936W92 (7.9 +/- .8 vs. 6.0 +/- .7 l/min/m2), a simultaneous increase in oxygen extraction prevented oxygen consumption from falling.

Nuclear localization of bacterial Streptoalloteichus hindustanus bleomycin resistance protein in mammalian cells

Prokaryotes produce a variety of toxins that affect genomic function of both eukaryotes and prokaryotes. The 375-base pair bacterial gene Streptoalloteichus hindustanus (Sh) ble encodes a small protein, Streptoalloteichus hindustanus bleomycin resistance protein (BRP), that inhibits in vitro DNA cleavage by the prokaryotic glycopeptide bleomycin, which is a clinically used anticancer drug. NIH/3T3 cells infected with a retroviral vector containing Sh ble (SH-9 cells) were highly resistant to the cytotoxicity of bleomycin-like drugs but not to the cytotoxicity of other, structurally unrelated, DNA-cleaving agents. Expression of BRP did not markedly alter total cellular content or distribution of bleomycin-like compounds. Fluorescently labeled bleomycin was primarily localized in cytoplasmic vesicles in NIH/3T3 and SH-9 cells, whereas BRP, which has no established nuclear localization sequence, was segregated to the nucleus and more specifically to euchromatin. This karyophilic BRP may intercept bleomycin in the nucleus.

Influence of vocabulary-age on unilateral picture-naming reaction times of normal subjects

The present study measured naming reaction times of normal subjects to unilaterally presented pictures corresponding to vocabulary levels of less than 5.5, 9.5 - 10.5, and greater than 18.0 years of age. An analysis of variance of latencies showed a significant interaction between visual fields and stimuli. Post hoc tests were interpreted to suggest that the normal right hemisphere was capable of performing certain differential picture encoding operations up to 10.5 years of age and not beyond. Also, unlike the left hemisphere, the right hemisphere does not appear to be organized on a developmental hierarchy, which corresponds with the clinical literature.