Prehospital fiberoptic intubation.

We present a case of a patient with severe multiple trauma who was treated at the scene by a physician-staffed trauma life support team. Due to a complete tracheal transection, a "cannot ventilate, cannot intubate"-situation occurred. The patient was then intubated using a fiberoptic bronchoscope in the prehospital setting. The current literature concerning fiberoptic intubation in emergencies is discussed.

Bioinformatic tools uncover the C-terminal strand of Rubisco's large subunit as hot-spot for specificity-enhancing mutations.

Rubisco assumes the double role of accumulating biomass by fixing carbon dioxide to ribulose-1,5-bisphosphate and binding of molecular oxygen to the same substrate. The specificity factor of this mutually competitive activity, defined as the ratio of carboxylation to oxygenation efficiency, varies considerably for reasons which remain obscure. The explanation and the enhancement of specificity are of high theoretical and practical interest. Despite a wealth of structures and experimental findings, the systematic analysis of available data is still at its beginning. Here, we (a) present an analysis of sequences of the large subunit which reliably finds specificity-enhancing mutations and ranks them according to the probability of success. For mutations near the C-terminus, we (b) show by simulations that the positive influence they have on specificity can be explained by the time-window hypothesis.

The oxygen-dependent deactivation and reactivation of spinach ribulose-1,5-bisphosphate carboxylase.

Ribulose-1,5-bisphosphate carboxylase-oxygenase (3-phospho-D-glycerate carboxy-lyase (dimerizing), EC 4.1.1.39) is deactivated by the removal of oxygen, and reversibly reactivated by its readdition to the enzyme solution. A short pulse of oxygen to the anaerobic enzyme solution is sufficient to trigger the reactivation process; the Ka value for this reaction was estimated as 0.12 mM oxygen. The enzyme could not be reactivated under anaerobic conditions by an organic oxidant (benzoylperoxide) or by sulfhydryl group reducing reagents (dithiothreitol or beta-mercaptoethanol), suggesting that the process of reactivation was oxygen specific. Furthermore, the inhibition of the reactivation by superoxide anion scavengers such as Tiron (1,2-dihydroxybenzene-3,5-disulfonic acid), copper penicillamine, hydroxylamine, nitroblue tetrazolium, and ascorbate, indicated that the monovalent reduced oxygen was involved as the reacting species in this process. The deactivation of the enzyme associated with the removal of oxygen was also sensitive to the presence of scavengers of O2(-), suggesting that superoxide anion was also involved in the deactivation process. Both the carboxylase and the oxygenase activities were similarly affected under all the experimental conditions studied. On the basis of these results it is argued that the enzyme molecules are able to reduce oxygen and that superoxide anion causes the deactivation or reactivation of the enzyme.

The acute coronary syndrome--pre-hospital diagnostic quality.

BACKGROUND AND OBJECTIVE: In the Austrian emergency medical service (EMS), emergency medical technician-staffed and physician-staffed vehicles are in operation. Patients with suspected acute coronary syndromes (ACS) are treated in the pre-hospital phase and transported to the hospital by an emergency physician (EP). This study evaluates the diagnostic performance of EPs in ACS and the impact of this emergency system on the outcome of ACS in an urban area. DESIGN: Retrospective case control study. METHODS: All protocol sheets from the emergency physicians were searched for the diagnosis of ACS. The database of the emergency department (ED) was searched for patients with ACS as an admission diagnosis or ACS as discharge diagnosis. For patients admitted to an intensive care unit (ICU), the medical history from the ICU was reviewed. According to the diagnosis and the aggressiveness of therapy, patients were divided in five categories of severity at each stage of care (pre-hospital category, ED category, ICU category). RESULTS: A total of 3585 patients was analysed. Only 17.8% of the patients with ACS as the admission diagnosis and 20.3% of the patients with ACS as the discharge diagnosis were transported by an EP. 46.8% of the ACS diagnosis by EPs were confirmed in hospital. Patients transported by EPs showed a higher all-cause mortality in hospital (1.6% vs. 0.6%; p=0.011). There was no significant correlation between the pre-hospital category of patients treated by EPs and the ED category. When a 12-lead-electrocardiogram was recorded, the correlation improved slightly (rho: 0.139; p=0.006). CONCLUSIONS: The percentage of ACS patients transported to hospital by an EP is very low, and EPs seem to be "over-aware" in the diagnosis of ACS.

Monitoring cytosolic pH of carboxysome-deficient cells of Synechocystis sp. PCC 6803 using fluorescence analysis.

Disruption of the ccmM gene in the cyanobacterium Synechocystis sp. PCC 6803 causes a deficiency of carboxysomes and impairs growth in ambient CO2. The effect of this gene defect on cellular metabolism was investigated using electron microscopy, biochemical and fluorescence analysis. Mutant cells were devoid of the characteristic dense polyhedral bodies called carboxysomes. The photosynthetic oxygen evolution was considerably lower in mutant cells compared to wild type, while Rubisco activity in cell extracts was similar. During photosynthetic CO2-dependent oxygen evolution, Rubisco Vmax dropped from 142 micromol mg-1 chlorophyll h-1 (WT) to 77 micromol mg-1 chlorophyll h-1 in the mutant cells, and the Km for Ci (inorganic carbon) increased from 0.5 mM (WT) to 40 mM. The fluorescent indicator, acridine yellow, was used for non-invasive measurements of cytoplasmic pH changes in whole cells induced by addition of Ci, making use of the decrease in fluorescence yield that accompanies cytoplasmic acidification. The experimental results indicate that control of the cytoplasmic pH is linked to the internal carbon pool (Ci). Both wild-type and ccmM-deficient cells showed a linear response of acridine yellow fluorescence quenching and, thus, of internal acidification, with respect to externally added inorganic carbon. However, the fluorescence analysis of mutant (carboxysome-free) cells indicated slower kinetics of Ci accumulation.

The use of fusion proteins to study HLA-B27-specific allorecognition.

Potential antigenic regions of the various external domains of the HLA-B27 antigen were expressed as fusion proteins in bacterial hosts and analyzed for their ability to induce humoral and cellular responses. Monoclonal antibodies directed against the proteins recognized monomorphic determinants of denatured HLA-antigens, but not B27-antigens expressed by intact lymphocytes. T-cell proliferation and IL-2 secretion were induced with a fusion protein representing regions of the first and second domains around amino acid residue 114. None of the fusion proteins stimulated cytotoxic T-lymphocytes (CTL) in an HLA-specific manner, although several included those amino acid sequences thought to be important for CTL recognition.

Immune responses to retinal autoantigens and peptides in equine recurrent uveitis.

PURPOSE: To test the hypothesis that autoimmune mechanisms are involved in horses in which equine recurrent uveitis (ERU) develops spontaneously. METHODS: Material obtained from horses treated for spontaneous disease by therapeutic routine vitrectomy was analyzed for total IgG content and IgG specific for S-Antigen (S-Ag) and interphotoreceptor retinoid-binding protein (IRBP). The cellular infiltrate of the vitreous was analyzed by differential counts of cytospin preparations and flow cytometry using equine lymphocyte-specific antibodies. Antigen-specific proliferation assays were performed comparing peripheral blood lymphocytes (PBLs) with vitreal lymphocytes by stimulation with S-Ag and several S-Ag- and IRBP-derived peptides. RESULTS: The total IgG content of specimens from horses with ERU was very high with great variability among the investigated samples (11.5 +/- 8.0 mg). Autoantibodies to S-Ag or IRBP or both were found in 72% of vitreous specimens from horses with uveitis. The leukocyte infiltrates (up to 2 x 10(8) cells per sample) were dominated by lymphocytes (>90%) in most cases (22/32). Flow cytometry showed that more than 50% of these cells were CD4(+) T cells. In vitro stimulation of vitreal lymphocytes, but not of PBL, showed a strong proliferative response to peptides derived from S-Ag or IRBP in 9 of 12 patients. CONCLUSIONS: In the eyes of horses with ERU, IgG antibodies and autoreactive T cells specific for retinal antigens were detected. These results strongly support the hypothesis that ERU is an autoimmune-mediated disease and is highly similar to recurrent uveitis in humans in both clinical and immunologic parameters.

Molecular mimicry as a therapeutic approach for an autoimmune disease: oral treatment of uveitis-patients with an MHC-peptide crossreactive with autoantigen--first results.

In the rat model of experimental autoimmune uveitis (EAU) we have demonstrated that a peptide from the sequence of human disease-associated MHC-class I antigens can induce uveitis upon immunization. Moreover, oral administration of this MHC-peptide tolerized Lewis rats to the disease induced with two different retinal autoantigens, retinal S-antigen (S-Ag) and IRBP. In uveitis patients T cells responding to S-Ag peptide also respond to the MHC-peptide, which shows crossreactivity with the major epitope from S-Ag due to some shared discontinuous amino acid homologies. The 14-mer peptide B27PD is derived from the sequence of all HLA-B antigens that are statistically associated with uveitis (including HLA-B27). Patients with long-lasting endogenous uveitis, suffering from side effects of conventional immuno-suppressive therapy or being therapy-refractive, were orally tolerized with peptide B27PD in this first open therapeutic trial. Patients received peptide three times a week over a 12 weeks period, while only low dose steroids were allowed as concomitant medication. The aims were (1) to investigate whether immunosuppressive therapy could be discontinued and steroids reduced while relapses of ocular inflammation reside and (2) to search for side effects. The Helsinki Declaration was strictly observed and the study design approved by the local ethical committee. The first patients orally tolerized with the HLA-peptide (two had stopped azathioprine immediately prior to onset of oral peptide treatment) could discontinue their steroids because of reduced intraocular inflammation. No side effects of therapy were observed. Oral tolerance induction with a peptide derived from the patients' own HLA-antigens and crossreactive with the organ-specific autoantigen seems to be a potent therapeutic approach.

Oral tolerance with an HLA-peptide mimicking retinal autoantigen as a treatment of autoimmune uveitis.

Endogenous uveitis is a T cell mediated autoimmune disease leading to impairment of visual acuity. The association of different uveitis entities with HLA-class I antigens and the discovery of antigenic mimicry between a peptide of uveitis-associated HLA-class I antigens and a peptide of retinal autoantigen led to a new hypothesis for the pathogenesis of uveitis. On the basis of this mechanism an open trial of oral tolerance induction with the HLA-peptide B27PD was initiated for nine patients with long lasting, therapy-refractive uveitis. Within 6 weeks of oral peptide treatment all patients responded with a marked decrease of intraocular inflammation, which allowed a reduction of systemic corticosteroids in seven patients. One patient, who suffered from an acute relapse, responded within 2 weeks, followed by an increase of visual acuity. In addition, two patients discontinued azathioprine immediately prior to oral tolerance induction without the occurrence of relapses. Visual acuity remained unchanged or increased in 14 of 16 eyes. One patient did not finish oral peptide treatment. None of these patients experienced any adverse events. It was concluded that the oral application of highly tolerogenic peptides might be a potent approach for the treatment of autoimmune diseases.

The kinetics of conformation change as determinant of Rubisco's specificity.

The molecular basis of Rubisco's specificity is investigated in terms of the structure and kinetics of the enzyme. We propose that the rates of the conformational changes (closing/opening) of the binding niche exert a crucial influence on apparent binding rates and the enzyme's specificity. An extended reaction scheme for binding and conformational kinetics is presented and expressed in a mathematical model. The closed conformation, known from X-ray structures, is assumed to be necessary for binding of the gaseous substrates (carbon dioxide and oxygen) and for catalysis. Opening the niche interrupts catalysis and enables a fast exchange of those molecules between the internal cavity and the surrounding solvent. Our model predicts that specificity of Rubisco for CO(2) increases with the rate by which the niche opens. This is due to the fact that binding of the carbon dioxide is faster than oxygen binding, which is hampered by spin inversion. The apparent rate of carbon dioxide binding correlates with the repetition rate of the conformational change, and the rate of oxygen binding with the probability of the closed state.

Comparison of lactate or BE during out-of-hospital cardiac arrest to determine metabolic acidosis.

During cardiopulmonary resuscitation, pH and base excess (BE) decrease to a variable degree due to metabolic acidosis. The main cause has been shown to be lactate, which cannot be eliminated sufficiently because of low perfusion during cardiac massage. Both BE and lactate can be measured in the prehospital phase. The aim of the study was to determine if BE and lactate are comparable variables during cardiopulmonary resuscitation (CPR) and if the measurement of lactate level alone would be sufficient to determine the patient's metabolic status and sufficiently reliable to determine the administration of buffer solutions. During the observation period, we registered 31 patients (21 males, ten females) who were resuscitated according to European Resuscitation Council recommendations, who had blood gas analysis and lactate levels measured in blood taken by arterial puncture or arterial line. The first measurement from each patient was taken after primary resuscitation (within 5-20 min). The mean lactate level was 9.85+/-2.98 (range, 4.1-18.7) mmol/l, and the mean BE was -15.0+/-5.98 (range, 5.5 to -24.3). There were statistically significant correlations between the lactate level and BE and pH (linear correlation, r=-0.673, P<0,001 and r=-0,683, P<0,001, respectively), but not with pO2 and pCO2. The receiver-operated curve analysis showed that a cut-off point of 7.0 mmol/l lactate indicates a BE below -10 with a sensitivity of 96% and a specificity of 67%. Lactate measurement is a valuable tool to determine metabolic acidosis during CPR and may be able to replace blood gas analysis in this situation.

[Strategies for quality assessment of emergency helicopter rescue systems. The Graz model]. / Strategien zur Optimierung notärztlicher Kompetenz in der Flugrettung. Das Modell Graz.

PURPOSE: Preclinical emergency medical treatment necessitates a comprehensive interdisciplinary knowledge by the emergency physician as well as a high level of manual dexterity. The quality of treatment therefore depends on the level of education and continuous training in emergency medical techniques. Based on an evaluation of the frequency of life-saving interventions by a physician-staffed rescue helicopter system, strategies for in-hospital training of relevant skills are suggested. MATERIAL AND METHODS: At the outset, 10 important areas of treatment (e.g. intubation, chest tube etc.) and their frequency in emergency medical services were defined as the standard to be attained by emergency physicians within 1 year. The selection of the areas of treatment was based to some extent on international recommendations. The actual frequencies of the prehospital interventions were compared to the required minimum numbers by retrospective analysis of the helicopter rescue database (NACA-X). RESULTS: During the observation period of 1 year, 20 emergency physicians responded to 956 prehospital emergency calls. A life-threatening condition requiring an on-site intervention occurred in only 521 (54.5%) patients, so that the majority of physicians did not perform the required minimum number of interventions. In order to maintain their level of skill, the emergency physicians were required to undertake additional training at the local university hospital. CONCLUSION: The frequency of on-site life-saving interventions in emergency medicine is insufficient to fulfill the quota necessary to maintain adequate training of emergency physicians. Only a link-up program at a hospital for primary care can ensure an adequate training level.

Beneficial effects of CCR1 blockade on the progression of chronic renal allograft damage.

The biology of chemokines and their receptors have been linked to the development of chronic allograft damage. Effects of CCR1 antagonist BX 471 were studied in a Fischer to Lewis renal transplantation model at days 10, 21 and 42 after transplantation. BX 471 treatment did not effectively reduce signs of acute rejection at day 10 but significantly improved allograft function and morphology at day 21 posttransplantation. When therapy was initiated on day 21 after transplantation, glomerulosclerosis and tubulointerstitial fibrosis were significantly inhibited by day 42 posttransplantation. Parallel decrease in infiltrating and proliferating mononuclear cells (ED1, CD8 and Ki67) was observed in treated allografts. Expression of acute phase reactive and proinflammatory genes (HO-1, osteopontin) and molecules associated with fibrosis (PAI-1, TGF-beta1, biglycan) was downregulated at day 21; reduced collagen deposition was observed, parallel to a significant lower number of alpha-SMA+ interstitial myofibroblasts. In situ hybridization demonstrated that biglycan expression was reduced following CCR1 blockade in interstitium of treated allografts. CCR1 antagonism was found to inhibit CCL5-induced secretion of biglycan by macrophages in vitro. CCR1 blockade significantly inhibited development and progression of chronic allograft damage. CCR1 antagonists may represent a therapeutic option for chronic inflammation and fibrosis in renal grafts.

The regulation of glucose-6-phosphate dehydrogenase in chloroplasts.

Glucose-6-phosphate dehydrogenase from intact pea chloroplasts is partially membrane bound and inactivated upon illumination. The inhibitory effect of light can be abolished by addition of methylviologen. Kinetic experiments with glucose-6-phosphate dehydrogenase reveal that, in the dark, the enzyme activity is strongly inhibited by the accumulation of NADPH. The inhibition of NADPH can be reversed by the addition of excess NADP+. The non-Michaelis-Menten-type kinetics suggest that the enzyme is stringently regulated by the ratio of NADPH to NADP+ plus NADPH, i.e., the "reduction charge". These observations seem to indicate that in the light the inhibition of glucose-6-phosphate dehydrogenase is due to a high reduction charge, whereas in the dark the enzyme is controlled by the metabolic demand for reducing equivalents.