The impact of providing blood to the scene of an accident on transfusion laboratory practice.

BACKGROUND: Haemorrhage is the leading cause of mortality during trauma. In 2012, London's Air Ambulance introduced Blood on Board (BOB), transfusing group O red cells (RBC) to trauma patients at the scene. OBJECTIVES: This study assessed the impact of BOB on the number of mixed field samples received by the laboratory, the number of group O RBC transfused to non-group O patients and the ratio of RBC to fresh frozen plasma (FFP) transfused in the initial 24 h. METHODS: Three major trauma centres collected data on patients for whom the major haemorrhage protocol was activated between August 2008 and February 2012 pre-BOB and March 2012 and December 2013 post-BOB. RESULTS: A total of 233 trauma patients were identified pre-BOB and 119 post-BOB. There was no significant difference in the percentage of group O units transfused to non-group O patients (75 vs 82%, P = 0·21) or the RBC : FFP ratio (pre-BOB mean 1·6 [interquartile range (IQR) 1·0-2·0]; post-BOB mean 1·7 [IQR 1·1-2·2], P = 0·24). There was no significant difference in the percentage of mixed field samples received (23% vs 27%, P = 0·3). CONCLUSION: The introduction of BOB did not change the proportion of group O RBC transfused or the RBC : FFP ratio; however, the proportion of acceptable samples decreased. This is largely due to an increase in blood samples not received from the post-BOB cohort, which we believe is probably due to patients who died at the scene. We have introduced robust systems to indicate reasons for not obtaining samples.

Sensory level electrical muscle stimulation: effect on markers of muscle injury.

BACKGROUND: Monophasic high voltage stimulation (MHVS) is widely prescribed for the treatment of inflammation associated with muscle injury. However, limited scientific evidence exists to support its purported benefits in humans. OBJECTIVE: To examine the efficacy of early initiation of MHVS treatment after muscle injury. METHODS: In a randomised, cross over design, 14 men performed repetitive eccentric contractions of the elbow flexor muscles followed by either MHVS or control treatment. MHVS treatments were applied five minutes and 3, 6, 24, 48, 72, 96, and 120 hours after eccentric contractions. RESULTS: MHVS resulted in a significant reduction (p<0.05) in delayed onset muscle soreness 24 hours after eccentric exercise compared with controls. Elbow extension was significantly increased immediately after administration of MHVS compared with controls. No significant differences were observed between MHVS treatment and controls for maximal isometric strength, flexed arm angle, or arm volume. CONCLUSIONS: Early and frequent application of MHVS may provide transient relief from delayed onset muscle soreness and short term improvements in range of motion after injurious exercise. However, MHVS treatment may not enhance recovery after muscle injury because of lack of improvements in strength and active range of motion.

Neutrophils injure cultured skeletal myotubes.

The purpose of the study was to test the hypothesis that neutrophils can injure cultured skeletal myotubes. Human myotubes were grown and then cultured with human blood neutrophils. Myotube injury was quantitatively and qualitatively determined using a cytotoxicity (51Cr) assay and electron microscopy, respectively. For the 51Cr assay, neutrophils, under non-in vitro-stimulated and N-formylmethionyl-leucyl-phenylalanine (FMLP)-stimulated conditions, were cultured with myotubes at effector-to-target cell (E:T) ratios of 10, 30, and 50 for 6 h. Statistical analyses revealed that myotube injury was proportional to the E:T ratio and was greater in FMLP-stimulated conditions relative to non-in vitro-stimulated conditions. Transmission electron microscopy, using lanthanum as an extracellular tracer, revealed in cocultures a diffuse appearance of lanthanum in the cytoplasm of myotubes and a localized appearance within cytoplasmic vacuoles of myotubes. These observations and their absence in control cultures (myotubes only) suggest that neutrophils caused membrane rupture and increased myotube endocytosis, respectively. Myotube membrane blebs were prevalent in scanning and transmission electron micrographs of cultures consisting of neutrophils and myotubes (E:T ratio of 5) and were absent in control cultures. These data support the hypothesis that neutrophils can injure skeletal myotubes in vitro and may indicate that neutrophils exacerbate muscle injury and/or delay muscle regeneration in vivo.

Indomethacin does not influence natural cell-mediated cytotoxic response to endurance exercise.

Natural cell-mediated cytotoxicity (NCMC) has been shown to be attenuated during recovery from high-intensity or prolonged exercise. Two theories have been proposed to explain the transient suppression of NCMC: prostaglandin-induced inhibition of natural killer (NK) cell activity or a numerical redistribution of NK cells. This study was designed to examine the effects of oral indomethacin (a prostaglandin inhibitor) on NCMC before and after 1 h of high-intensity running (85% maximal oxygen uptake). A secondary purpose was to compare whole blood and isolated peripheral blood mononuclear cell assay procedures for assessing NCMC. Ten male distance runners completed two trials that were preceded by either 48 h of indomethacin (Indo; 150 mg/day) or no treatment (control). NK (CD3(-)/CD16(+)/CD56(+)) cell concentrations were significantly elevated postexercise but were not affected by Indo. NCMC was significantly suppressed at 1.5 h of recovery relative to preexercise only with the whole blood assay procedure. Indo was not found to influence NCMC, leukocyte, or lymphocyte subset concentrations. Mean cytotoxic response was significantly greater with the whole blood method.

Splenic infarction caused by a large thoracic aortic thrombus.

We report on a patient with left upper quadrant pain as a result of splenic infarction; the patient was subsequently found to have a thoracoabdominal aortic thrombus extending through the celiac axis. The patient was successfully treated with an aortic thrombectomy guided by intraoperative transesophageal echocardiography.

Profound normovolemic hemodilution: hemostatic effects in patients and in a porcine model.

Previous systematic investigations of the hemostatic effects of normovolemic hemodilution (NHD) have not explored the influence of hematocrits less than 20% in humans or animals. However, clinical interest in maximizing the perioperative conservation of erythrocytes may involve profound NHD beyond traditionally accepted empiric end points. We report here on coagulation data in eight healthy adolescent patients undergoing profound NHD in concert with surgical correction of idiopathic scoliosis, and in 29 swine undergoing experimental stepwise NHD until death. Blood was replaced with 5% albumin in 0.9% saline in our patients, and with 5% albumin in lactated Ringer's solution in our pigs. A 75% blood volume exchange in our patients yielded a platelet count (PLT) of 158 +/- 26 x 10(3)/microL, fibrinogen concentration (FIB), 50 +/- 7 mg/dL, prothrombin time (PT), 25.4 +/- 2.6 s, activated partial thromboplastin time (aPTT), 87 +/- 15s, and a nadir hemoglobin of 2.8 +/- 0.2 g/dL; however, global oxygen delivery as assessed by body oxygen consumption remained adequate. Coagulation during the experimental porcine hemodilution was assessed by measuring PLT, FIB, PT, and aPTT, as well as by measurement of coagulation factor activities. In neither species did clinically significant thrombocytopenia (PLT < 100 x 10(3)/ microL) become manifest prior to clinical or other laboratory evidence of coagulopathy. Rather, a combined deficiency of coagulation factors explains the coagulopathy developing during NHD in both patients and swine. Abnormal hemostasis develops prior to compromise of global tissue oxygenation, assessed by mixed venous oxygen saturation and total body oxygen consumption, during NHD in healthy patients anesthetized as described. Therefore, NHD may be more limited by preservation of normal coagulation than of global oxygen delivery and consumption.

Endotoxin enhances hypoxic constriction of rat aorta and pulmonary artery through induction of EDRF/NO synthase.

The vascular response to hypoxia in endotoxin (lipopolysaccharide; LPS)-exposed rat pulmonary artery (PA) and thoracic aorta (AO) was investigated and the mechanism of the observed hypoxic responses defined. In isometric tension studies, LPS-treated AO and PA rings, with and without endothelium, demonstrated decreased (P < 0.05) contractile response to phenylephrine (PE EC50), and the dose response was shifted to the right (P < 0.01) compared with non-LPS treated rings. Both vessel types responded to hypoxia with a markedly increased (P < 0.01) and sustained (P < 0.01) constriction when preexposed to LPS. Control non-LPS rings with endothelium intact had a transient vasoconstriction in early hypoxia, which was abolished with removal of the endothelium. N omega-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide (NO) synthase, increased the PE EC50 tension in LPS-treated rings, markedly reduced the duration and magnitude of the hypoxic vasoconstriction in LPS-treated rings, and attenuated the transient vasoconstriction seen in endothelium-intact, non-LPS rings (all P < 0.05). L-Arginine reversed the L-NAME effects. Hypoxia decreased guanosine 3',5'-cyclic monophosphate (cGMP) content 54 +/- 4% in all LPS and 33 +/- 4% in the non-LPS intact rings (P < 0.05). L-NAME reduced cGMP content 90 +/- 5% in all LPS rings. Indomethacin inhibited formation of a constriction factor in aortic LPS-treated rings (P < 0.01) that was endothelium dependent and unaffected by the presence of L-NAME.(ABSTRACT TRUNCATED AT 250 WORDS)

Differences between aortic and radial artery pressure associated with cardiopulmonary bypass.

Previous investigators have identified an aortic-to-radial artery pressure gradient thought to develop during rewarming and discontinuation of cardiopulmonary bypass. The authors measured mean aortic and radial artery pressures before, during, and after cardiopulmonary bypass in 30 patients, to determine when the pressure gradient develops. The pressure gradient was also measured before and after intravenous injections of sodium nitroprusside (1 microgram/kg) and phenylephrine (7 micrograms/kg) to determine the effect of changes in systemic vascular resistance. A significant (P less than 0.05) pressure gradient (mean +/- SEM = 4.9 +/- 0.7 mmHg) developed upon initiation of cardiopulmonary bypass. This gradient did not change significantly during the middle of bypass (4.2 +/- 0.5 mmHg), with rewarming (4.8 +/- 0.7 mmHg), immediately prior to discontinuation of bypass (4.6 +/- 0.7), or 5 and 10 min following bypass (4.9 +/- 0.9 and 4.8 +/- 0.7 mmHg). Sodium nitroprusside significantly decreased systemic vascular resistance, by 15 +/- 2%, during the middle of bypass but did not affect the pressure gradient. Likewise, phenylephrine increased the systemic vascular resistance by 52 +/- 6% and 34 +/- 4% during the middle of bypass and rewarming, respectively, without affecting the pressure gradient. Although the exact mechanisms responsible for the pressure gradient remain unknown, these results suggest its etiology is associated with events occurring during initiation of cardiopulmonary bypass rather than with rewarming or discontinuation of cardiopulmonary bypass.

Pseudomonas cepacia suppression of sunflower wilt fungus and role of antifungal compounds in controlling the disease.

In a field experiment, Pseudomonas cepacia J82rif and J51rif increased sunflower emergence in the presence of the fungus Sclerotinia sclerotiorum. Pyrrolnitrin, aminopyrrolnitrin, and monochloroaminopyrrolnitrin were isolated from J82 and identified by using thin-layer chromatography, high-performance liquid chromatography, and electron impact-mass, UV, and infrared spectroscopy. In growth chamber experiments, two antibiosis-negative mutants were not different from the parent strain in protecting the seeds from the fungus.

Persistence of introduced Bradyrhizobium japonicum strains in forming nodules in subsequent years after inoculation in Wisconsin soils.

Nodulation of soybeans by indigenous and inoculum strains of Bradyrhizobium japonicum was studied in field experiments in Wisconsin from 1983 to 86. Aqueous suspensions of bacteria were applied to seeds at the time of planting at levels of 7 × 10(7)-10(10) bacteria per 2.5-cm row. The predominant indigenous serogroup was 123 in these soils. Six different inoculum strains were used (two from serocluster 123, two from serogroup 110, and one each from serogroups 122 and C1). Nodule occupants were identified using spontaneous antibiotic-resistant mutations in the inoculum strains, phage typing, and serotyping. In the 1983 experiment, the majority of nodules were formed by the inoculum strains in almost all cases (up to 100% in some cases), in two different soils containing 3.5 × 10(5) indigenous B. japonicum per gram. After 2 years without inoculation at the same two site, the inoculum strains did not form many nodules on uninoculated soybeans (less than 10% in most cases; less than 30% in all cases). In inoculation experiments carried out in 1985 and 1986, four inoculum strains were used (3 members of 123 serocluster and USDA 110str); inocula containing 10(8) bacteria per 2.5-cm row formed less than42%ofthe nodules in soils containing 1 × 10(4)-4 × 10(4)B. japonicum per gram. The major conclusions are (i) the success of inoculation in Midwestern U.S. soils is highly variable, even with members of the (highly competitive) 123 serocluster, and (ii) successful inoculation in 1 year in a Wisconsin soil does not ensure that the inoculated strain will persist in forming nodules in that field in subsequent years without further inoculation. Key words: Bradyrhizobium japonicum, strain persistence, field trials.

Attenuation of the hemodynamic responses to endotracheal intubation with preinduction intravenous labetalol.

Endotracheal intubation following anesthesia induction frequently produces hypertension and tachycardia. This study evaluated the efficacy of preinduction IV labetalol for attenuating the hemodynamic responses to intubation following thiopental and succinylcholine induction of anesthesia. Two hours after diazepam (10 mg by mouth), 60 patients were randomized in a double-blind manner and received IV saline or labetalol at doses of 0.25, 0.5, 0.75, or 1 mg/kg in a parallel design study. Five minutes later, thiopental (4 mg/kg) and succinylcholine (1 mg/kg) were administered, and the trachea was intubated in 2 minutes. Nitrous oxide (70%) anesthesia was maintained for 10 minutes. Hemodynamic parameters were grouped and analyzed for significance (p less than 0.05) by two-way repeated measures analysis of variance and t-test with Bonferroni adjustments. Baseline group demographics and hemodynamics were comparable. All doses of labetalol significantly attenuated the rate-pressure product increase immediately postintubation versus placebo. There was a dose-dependent attenuation of the increases in heart rate and the systolic, diastolic, and mean blood pressures versus placebo following intubation. IV labetalol at doses up to 0.75 mg/kg offers an effective pharmacologic means of attenuating preoperative hemodynamic responses to endotracheal intubation.

Isolation of competition-defective mutants of Rhizobium fredii.

We coupled Tn5 mutagenesis with a competition assay to isolate mutants of Rhizobium fredii USDA 257 that are defective in competition for nodulation of soybeans. Two mutants with single Tn5 inserts in the chromosome showed reduced competitiveness in vermiculite but were identical to the wild-type strain in symbiotic properties when inoculated alone. Recombination of Tn5 and flanking genomic regions cloned from the mutants into the parent strain showed that Tn5 was responsible for the mutant phenotype.

Expression of symbiotic genes of Rhizobium japonicum USDA 191 in other rhizobia.

A 200-megadalton plasmid was mobilized from Rhizobium japonicum USDA 191 to other Rhizobium strains either that cannot nodulate soybeans or that form Fix- nodules on certain cultivars. The symbiotic properties of the transconjugants indicate that both soybean specificity for nodulation and cultivar specificity for nitrogen fixation are plasmid encoded.