Proof-of-concept rare cancers in drug development: the case for rhabdomyosarcoma

Rare diseases typically affect fewer than 200,000 patients annually, yet because thousands of rare diseases exist, the cumulative impact is millions of patients worldwide. Every form of childhood cancer qualifies as a rare disease-including the childhood muscle cancer, rhabdomyosarcoma (RMS). The next few years promise to be an exceptionally good era of opportunity for public-private collaboration for rare and childhood cancers. Not only do certain governmental regulation advantages exist, but these advantages are being made permanent with special incentives for pediatric orphan drug-product development. Coupled with a growing understanding of sarcoma tumor biology, synergy with pharmaceutical muscle disease drug-development programs, and emerging publically available preclinical and clinical tools, the outlook for academic-community-industry partnerships in RMS drug development looks promising.

A randomised, non-crossover study of the GuardianCPV Laryngeal Mask versus the LMA Supreme in paralysed, anaesthetised female patients

We investigated the hypothesis that the oropharyngeal leak pressure would differ between the GuardianCPV™ and the LMA Supreme™ in anaesthetised patients. We randomly assigned 120 patients to receive either the GuardianCPV or the LMA Supreme for airway management. Oropharyngeal leak pressure was measured during cuff inflation from 0 to 40 ml in 10-ml steps. In addition, intracuff pressure, fibreoptic position of the airway and drain tube, device insertion success, ventilation success, blood staining and airway morbidity were determined. Mean (SD) oropharyngeal leak pressures for clinically acceptable cuff volumes of 20-40 ml were 31 (7) cmH2O for the GuardianCPV and 27 (7) cmH2O for the LMA Supreme (p < 0.0001); mean (SD) intracuff pressures were 68 (33) cmH2O and 88 (43) cmH2O (p < 0.0001), respectively. We found no differences in device insertion success, ventilation success, fibreoptic position of the airway and drain tube, blood staining or airway morbidity. We conclude that the oropharyngeal leak pressure is better for the GuardianCPV than for the LMA Supreme in anaesthetised patients.

Analysis of proteasome generated antigenic peptides by mass spectrometry

Mass spectrometry (MS) is today one of the most important analytical techniques in biosciences. The development of electro spray ionization (ESI) as a gentle ionization method, in which molecules are not destroyed, has revolutionized the analytic of peptides. MS is an ideal technique for detection and analysis of peptides generated by in vitro experiments using purified 20S proteasomes. It also provides a convenient and sensitive way to monitor the processing activity of enzymes. The combination of high performance liquid chromatography (HPLC) with ESI-MS allows the analysis of complex samples with separation in their specific constituents by LC and their subsequent detection by MS.

Driving forces of proteasome-catalyzed peptide splicing in yeast and humans

Proteasome-catalyzed peptide splicing (PCPS) represents an additional activity of mammalian 20S proteasomes recently identified in connection with antigen presentation. We show here that PCPS is not restricted to mammalians but that it is also a feature of yeast 20S proteasomes catalyzed by all three active site β subunits. No major differences in splicing efficiency exist between human 20S standard- and immuno-proteasome or yeast 20S proteasome. Using H(2)(18)O to monitor the splicing reaction we also demonstrate that PCPS occurs via direct transpeptidation that slightly favors the generation of peptides spliced in cis over peptides spliced in trans. Splicing efficiency itself is shown to be controlled by proteasomal cleavage site preference as well as by the sequence characteristics of the spliced peptides. By use of kinetic data and quantitative analyses of PCPS obtained by mass spectrometry we developed a structural model with two PCPS binding sites in the neighborhood of the active Thr1.

Protein kinase C iota as a therapeutic target in alveolar rhabdomyosarcoma

Alveolar rhabdomyosarcoma is an aggressive pediatric cancer exhibiting skeletal muscle differentiation. New therapeutic targets are required to improve the dismal prognosis for invasive or metastatic alveolar rhabdomyosarcoma. Protein kinase C iota (PKCι) has been shown to play an important role in tumorigenesis of many cancers but little is known about its role in rhabdomyosarcoma. Our gene expression studies in human tumor samples revealed overexpression of PRKCI. We confirmed overexpression of PKCι at the mRNA and protein level using our conditional mouse model that authentically recapitulates the progression of rhabdomyosarcoma in humans. Inhibition of Prkci by RNA interference resulted in a dramatic decrease in anchorage-independent colony formation. Interestingly, treatment of primary cell cultures using aurothiomalate (ATM), which is a gold-containing classical anti-rheumatic agent and a PKCι-specific inhibitor, resulted in decreased interaction between PKCι and Par6, decreased Rac1 activity and reduced cell viability at clinically relevant concentrations. Moreover, co-treatment with ATM and vincristine, a microtubule inhibitor currently used in rhabdomyosarcoma treatment regimens, resulted in a combination index (C. I.) of 0.470–0.793 through cooperative accumulation of non-proliferative multinuclear cells in the G2/M phase, indicating that these two drugs synergize. For in vivo tumor growth inhibition studies, ATM demonstrated a trend towards enhanced vincristine sensitivity. Overall, these results suggest that PKCι is functionally important in alveolar rhabdomyosarcoma anchorage-independent growth and tumor cell proliferation and that combination therapy with ATM and microtubule inhibitors holds promise for the treatment of alveolar rhabdomyosarcoma.

Directly measured mucosal pressures produced by the i-gel™ and Laryngeal Mask Airway Supreme™ in paralysed anaesthetised patients

The i-gel™ and LMA Supreme™ are extraglottic airway devices with non-inflatable and inflatable cuffs, respectively. We hypothesised that directly measured mucosal pressures would differ between these devices in anesthetised paralysed patients. Thirty patients were randomly allocated to receive one of these two devices. Four pressure sensors were attached to all airway devices used to measure mucosal pressure at the base of the tongue, the distal oropharynx, the hypopharynx and the pyriform fossa. At these four places, median (IQR [range]) i-gel mucosal pressures were 8.0 (2.7-10.7 [0-26.7]), 5.0 (2.7-7 [1.0-37.3]), 9.3 (2.7-13.3 [0-22.7] and 8.0 (2.7-10.7 [0-25.3]) cmH(2)O, respectively, and for the LMA Supreme, these were 5.0 (0.5-8.0 [0-33]), 4.0 (1.3-9.3 [0-24]), 10.7 (4-17.3 [0-26.7]) and 8.0 (0-10.7 [0-36]) cmH(2)O, respectively. Mucosal pressures were low and similar for both devices. The LMA Supreme mucosal pressures were higher in the hypopharynx than in the distal oropharynx (p = 0.04) and base of the tongue (p = 0.011). There were no pressure differences between the locations for the i-gel.

Determination of the silicon concentration in plant material using Tiron extraction

• The quantification of silicon (Si) in plants generally requires a digestion procedure before the determination of the dissolved Si concentration by spectrometric analysis. Recent procedures produce rapid and accurate measurements, but are based on either hazardous chemicals or sophisticated instrumentation. • Here, we describe a simpler procedure using Tiron. Tiron [4,5-dihydroxy-1,3-benzene-disulfonic acid disodium salt, (HO)(2)C(6)H(2)(SO(3)Na)(2)] is currently used as a selective extractant for amorphous silica in soils. Because Si in the shoots is mostly composed of amorphous opaline silica particles (i.e. phytoliths), we tested the Tiron extraction procedure for plants. • Our results are critically discussed in relation to two other standard procedures: electrothermal vaporization determination and high-temperature lithium-metaborate digestion. • We demonstrate that Tiron extraction is an alternative method which allows the rapid, safe and accurate quantification of Si in shoots of various plants covering a wide range of Si concentrations.

Introgressive hybridization in southern African baboons shapes patterns of mtDNA variation

Species, as main evolutionary units have long been considered to be morphological entities with limited hybridization potential. The occurrence of taxa which maintain morphological distinctness despite extensive hybridization is an interesting phenomenon. To understand the evolution of these taxa, descriptions of contemporary morphological and genetic variation are essential, also to reconstruct sound phylogenies. Baboons, with their wide geographic range, variant morphotypes, and extensive hybridization offer an intriguing model for those studies. We focus on the complex situation in southern Africa that, in contrast to east Africa, has been neglected in terms of baboon hybridization history. We aim to clarify the distribution and identify possible overlapping zones between different, previously described mitochondrial (mt) DNA clades of baboons that do not match with the ranges of traditionally recognized species. On the basis of the widespread sampling and mitochondrial cytochrome b gene sequencing, we constructed a phylogenetic tree that separates representatives of the two southern African baboon species, yellow and chacma baboons, into six clades: southern, northern and eastern chacmas, Kinda baboons and southern and Luangwa yellow baboons. The ranges of the chacma clades come into close contact or overlap in two regions in the Republic of South Africa and Namibia. Our phylogenetic reconstruction reveals mitochondrial paraphyly for chacma and yellow baboons, which is probably caused by introgressive hybridization and subsequent nuclear swamping, whereby males of the chacma morphotype population from the south invaded the yellow morphotype population in the north bringing their morphotype into a population that maintained its yellow baboon mtDNA.

Discrete-trial alternation in the rat

The acquisition and maintenance by rats of single alternation, double alternation, and four other repeating patterns of reinforced and non-reinforced trials was studied in a discrete-trial lever-pressing situation. The rats learned all these patterns in a small number of experimental sessions. Single alternation was learned more rapidly than the more complex patterns. Rate of learning single and double alternation decreased moderately as inter-trial interval increased. Abrupt changes in the scheduling of trials, either by doubling the inter-trial interval or by shifting from fixed to variable trial spacing, temporarily disrupted the patterned performance. Two hypotheses concerned with the means by which the rats could have learned to conform to the pattern were examined: (1) "timing" of the interval between successive reinforcements; and (2) control of responding on a trial by the outcome of preceding trials, depending on the consistency with which these outcomes were associated with reinforced or non-reinforced trials in the pattern and on how many trials back these outcomes occurred. The second hypothesis accounted for the relative frequency of errors on trials at various locations in the sequences, and predicted most of the changes in error frequency observed in experiments in which "inter-trial stimuli" were added to the sequences.

The 20S proteasome splicing activity discovered by SpliceMet

The identification of proteasome-generated spliced peptides (PSP) revealed a new unpredicted activity of the major cellular protease. However, so far characterization of PSP was entirely dependent on the availability of patient-derived cytotoxic CD8+ T lymphocytes (CTL) thus preventing a systematic investigation of proteasome-catalyzed peptide splicing (PCPS). For an unrestricted PSP identification we here developed SpliceMet, combining the computer-based algorithm ProteaJ with in vitro proteasomal degradation assays and mass spectrometry. By applying SpliceMet for the analysis of proteasomal processing products of four different substrate polypeptides, derived from human tumor as well as viral antigens, we identified fifteen new spliced peptides generated by PCPS either by cis or from two separate substrate molecules, i.e., by trans splicing. Our data suggest that 20S proteasomes represent a molecular machine that, due to its catalytic and structural properties, facilitates the generation of spliced peptides, thereby providing a pool of qualitatively new peptides from which functionally relevant products may be selected.

Pulmonary effects of bupivacaine, ropivacaine, and levobupivacaine in parturients undergoing spinal anaesthesia for elective caesarean delivery: a randomised controlled study

BACKGROUND

Spinal anaesthesia is the method of choice for elective caesarean delivery, but has been reported to worsen dynamic pulmonary function when using bupivacaine. Similar investigations are lacking for ropivacaine and levobupivacaine. We have therefore compared the pulmonary effects of intrathecal bupivacaine, ropivacaine and levobupivacaine used for caesarean delivery.

METHODS

Forced vital capacity, forced expiratory volume in the first second, and peak expiratory flow rate were measured in 48 parturients before and after onset of spinal anaesthesia using either 0.5% bupivacaine 10 mg, 1% ropivacaine 20 mg, or 0.5% levobupivacaine 10 mg. Apgar scores and umbilical arterial pH were recorded.

RESULTS

The final level of sensory blockade was not different between groups. Forced vital capacity was significantly decreased with bupivacaine (3.6+/-0.5 L to 3.5+/-0.4 L, P<0.05) and ropivacaine (3.2+/-0.4 L to 3.1+/-0.5 L, P<0.05), but not with levobupivacaine (3.6+/-0.5 L to 3.4+/-0.6 L). Forced expiratory volume during the first second was not decreased in any group. Peak expiratory flow rate was significantly decreased with ropivacaine (5.5+/-1.5 L/s to 5.0+/-1.1 L/s, P<0.05) and levobupivacaine (from 6.0+/-1.1 L/s to 5.2+/-0.9 L/s, P<0.01). Neonatal vital parameters did not differ between the three groups.

CONCLUSIONS

Decreases in maternal pulmonary function tests were similar following spinal anaesthesia with bupivacaine, ropivacaine, or levobupivacaine for caesarean delivery. The clinical maternal and neonatal effects of these alterations appeared negligible.

Copine-III interacts with ErbB2 and promotes tumor cell migration

ErbB2 amplification and overexpression in breast cancer correlates with aggressive disease and poor prognosis. To find novel ErbB2-interacting proteins, we used stable isotope labeling of amino acids in cell culture followed by peptide affinity pull-downs and identified specific binders using relative quantification by mass spectrometry. Copine-III, a member of a Ca(2+)-dependent phospholipid-binding protein family, was identified as binding to phosphorylated Tyr1248 of ErbB2. In breast cancer cells, Copine-III requires Ca(2+) for binding to the plasma membrane, where it interacts with ErbB2 upon receptor stimulation, an interaction that is dependent on receptor activity. Copine-III also binds receptor of activated C kinase 1 and colocalizes with phosphorylated focal adhesion kinase at the leading edge of migrating cells. Importantly, knockdown of Copine-III in T47D breast cancer cells causes a decrease in Src kinase activation and ErbB2-dependent wound healing. Our data suggest that Copine-III is a novel player in the regulation of ErbB2-dependent cancer cell motility. In primary breast tumors, high CPNE3 RNA levels significantly correlate with ERBB2 amplification. Moreover, in an in situ tissue microarray analysis, we detected differential protein expression of Copine-III in normal versus breast, prostate and ovarian tumors, suggesting a more general role for Copine-III in carcinogenesis.

Prospective randomized controlled multi-centre trial of cuffed or uncuffed endotracheal tubes in small children

BACKGROUND

The use of cuffed tracheal tubes (TTs) in small children is still controversial. The aim of this study was to compare post-extubation morbidity and TT exchange rates when using cuffed vs uncuffed tubes in small children.

METHODS

Patients aged from birth to 5 yr requiring general anaesthesia with TT intubation were included in 24 European paediatric anaesthesia centres. Patients were prospectively randomized into a cuffed TT group (Microcuff PET) and an uncuffed TT group (Mallinckrodt, Portex, Rüsch, Sheridan). Endpoints were incidence of post-extubation stridor and the number of TT exchanges to find an appropriate-sized tube. For cuffed TTs, minimal cuff pressure required to seal the airway was noted; maximal cuff pressure was limited at 20 cm H(2)O with a pressure release valve. Data are mean (SD).

RESULTS

A total of 2246 children were studied (1119/1127 cuffed/uncuffed). The age was 1.93 (1.48) yr in the cuffed and 1.87 (1.45) yr in the uncuffed groups. Post-extubation stridor was noted in 4.4% of patients with cuffed and in 4.7% with uncuffed TTs (P=0.543). TT exchange rate was 2.1% in the cuffed and 30.8% in the uncuffed groups (P<0.0001). Minimal cuff pressure required to seal the trachea was 10.6 (4.3) cm H(2)O.

CONCLUSIONS

The use of cuffed TTs in small children provides a reliably sealed airway at cuff pressures of <or=20 cm H(2)O, reduces the need for TT exchanges, and does not increase the risk for post-extubation stridor compared with uncuffed TTs.

Comparison of wheat and rye flour solutions for skin prick testing: a multi-centre study (Stad 1)

BACKGROUND

Skin prick testing (SPT) is the basic method for diagnosing IgE-mediated allergies. However, skin reactivity is related to the quality of allergen extracts, which are often poorly defined for occupational allergens.

OBJECTIVE

To compare wheat and rye flour SPT solutions from different producers.

MATERIALS AND METHODS

Standardized SPTs were performed in seven allergy centres with wheat and rye flour solutions from four producers in 125 symptomatic bakers. Optimal cut-off levels for weal sizes were assessed with the Youden Index. Comparisons between SPT results of different solutions were made with flour-specific IgE (sIgE) as the gold standard. Sensitivities, specificities, positive and negative predictive values, and test efficiencies were calculated and compared with McNemar and chi(2)-tests. The influence of the choice of the gold standard (sIgE or challenge) test was examined for 95 subjects. Additionally, SPT solutions were analysed for protein and antigen content.

RESULTS

The optimal cut-off level for all SPT solutions was a weal size of >or=1.5 mm. While differences between wheat and rye flours were small, differences between producers were important. Variability of sensitivities (0.31-0.96), negative predictive values (0.42-0.91), and test efficiencies (0.54-0.90) were higher than variations of specificities (0.74-1.00) and positive predictive values (0.88-1.00). Similar results were obtained when using challenge test results as the gold standard. Variability could be explained by the different antigen contents of the SPT solutions.

CONCLUSION

There is a wide variability of SPT solutions for wheat and rye flour from different producers, mainly with respect to sensitivities, negative predictive values, and test efficiencies. Improvement and standardization of SPT solutions used for the diagnosis of baker's asthma are highly recommended.

[Pancytopenia, fever, and splenomegaly in a 2-year-old boy]

HISTORY

Suspected of having a systemic malignancy a 22-month-old boy was admitted to hospital with fever, pancytopenia and hepatosplenomegaly. The boy was of ethnically German origin and no travel abroad was reported.

DIAGNOSIS

Intensive search for a focus of infection, laboratory tests and bone marrow microscopy failed to be diagnostic. Serological findings and detection of Leishmania DNA in bone marrow by polymerase chain reaction (PCR) led to the diagnosis of visceral leishmaniasis. On explicit questioning the child's parents reported a stay in Greece 18 months before onset of symptoms.

TREATMENT AND COURSE

On the fourth day of i.v. therapy with liposomal amphotericin B, 3mg/kg/d for 10 days, the fever subsided. Platelets and leukocytes regained normal levels. The child was discharged after 10 days of treatment and received two more doses on days 14 and 21.

CONCLUSION

Negative results on microscopic bone marrow inspection do not rule out visceral leishmaniasis. Detection of anti-Leishmania antibodies may support the suspected diagnosis and provide the indication for PCR technique.

Association of genetic polymorphisms in the ACE, ApoE, and TGF beta genes with early onset ischemic heart disease

BACKGROUND

The genetic factors that contribute to ischemic heart disease (IHD) are poorly understood, and it is likely that multiple genes acting independently or synergistically contribute to the risk of IHD and outcome. The genes for angiotensin-converting enzyme (ACE) and apolipoprotein E (ApoE) have been implicated independently in the risk of IHD.

HYPOTHESIS

This study examined whether genetic polymorphisms in the ACE and ApoE genes are associated with early onset IHD. Polymorphisms in a third gene, transforming growth factor beta 2 (TGF beta 2), with a known role in wound repair and cardiac development, are also examined with respect to early onset IHD.

METHODS

In all, 101 patients with IHD and onset of disease before 55 years for men and 60 years for women, and 100 controls with angiographically confirmed normal coronary arteries were recruited for this study. The ACE, ApoE, and TGF beta 2 genotypes were determined by polymerase chain reaction amplification or Southern blotting and were compared with the patient's clinical and family histories.

RESULTS AND CONCLUSION

The frequency of the ACE D allele was significantly lower in the patient group (0.475) than in the control group (0.59, p = 0.03), which was attributed to a reduction in the number of patients with the DD genotype (patients: 24% DD, controls: 33% DD). Sudden cardiac death was also associated with the DD genotype. These data are consistent with the ACE D allele contributing to a fatal outcome. No association between the DD genotype and risk of myocardial infarction, presenting age, extent of vessel disease, family history, hypertension, or hypercholesterolemia was seen. Analysis of the ApoE genotype showed no association with early onset IHD. There was no evidence for a synergistic effect between the ACE and ApoE genotypes on the risk of early onset IHD. A polymorphism in the TGF beta 2 gene was rare and not associated with early onset IHD.

PDGFR-A is a therapeutic target in alveolar rhabdomyosarcoma

Alveolar rhabdomyosarcoma is an aggressive skeletal muscle cancer of childhood. Our initial studies of rhabdomyosarcoma gene expression for patients enrolled in a national clinical trial suggested that platelet-derived growth factor receptor A (PDGFR-A) may be a mediator of disease progression and metastasis. Using our conditional mouse tumor models that authentically recapitulate the primary mutations and metastatic progression of alveolar rhabdomyosarcomas in humans, we found by immunoblotting and immunokinase assays that PDGFR-A and its downstream effectors, mitogen-activated protein kinase and Akt, were highly activated in both primary and metastatic tumors. Inhibition of PDGFR-A by RNA interference, small molecule inhibitor or neutralizing antibody had a dramatic effect on tumor cell growth both in vitro and in vivo, although resistance evolved in one-third of tumors. These results establish proof-of-principal for PDGFR-A as a therapeutic target in alveolar rhabdomyosarcoma.

Prediction of challenge test results by flour-specific IgE and skin prick test in symptomatic bakers

BACKGROUND

Wheat and rye flours are among the most important allergens causing occupational asthma. Usually, the diagnosis of baker's asthma is based on inhalation challenge tests with flours.

AIMS OF THE STUDY

To evaluate the relevance of flour-specific serum immunoglobulin E (IgE) and skin prick test (SPT) in the diagnosis of baker's asthma and to define flour-specific IgE concentrations and wheal sizes that allow a prediction of the outcome of challenge testing.

METHODS

Bronchial and nasal challenge tests with wheat (rye) flour were performed in 71 (95) symptomatic bakers. Determinations of flour-specific IgE as well as SPTs were performed in all subjects. Analyses included the calculation of sensitivity, specificity, positive (PPV) and negative predictive values (NPV) at different IgE concentrations and different wheal sizes, and receiver-operating characteristics (ROC) plots with the challenge result as gold standard.

RESULTS

Thirty-seven bakers were positive in the challenge with wheat flour, while 63 were positive with rye flour. Depending on the flour-specific IgE concentrations (wheal size), PPV was 74-100% (74-100%) for wheat and 82-100% (91-100%) for rye flour, respectively. The minimal cut-off values with a PPV of 100% were 2.32 kU/l (5.0 mm) for wheat flour and 9.64 kU/l (4.5 mm) for rye flour. The shapes of the ROC plots were similar for wheat and rye flour.

CONCLUSION

High concentrations of flour-specific IgE and clear SPT results in symptomatic bakers are good predictors for a positive challenge test. Challenge tests with flours may be avoided in strongly sensitized bakers.

Wave-particle duality of C(60) molecules

Quantum superposition lies at the heart of quantum mechanics and gives rise to many of its paradoxes. Superposition of de Broglie matter waves' has been observed for massive particles such as electrons, atoms and dimers, small van der Waals clusters, and neutrons. But matter wave interferometry with larger objects has remained experimentally challenging, despite the development of powerful atom interferometric techniques for experiments in fundamental quantum mechanics, metrology and lithography. Here we report the observation of de Broglie wave interference of C(60) molecules by diffraction at a material absorption grating. This molecule is the most massive and complex object in which wave behaviour has been observed. Of particular interest is the fact that C(60) is almost a classical body, because of its many excited internal degrees of freedom and their possible couplings to the environment. Such couplings are essential for the appearance of decoherence, suggesting that interference experiments with large molecules should facilitate detailed studies of this process.

Comparison of high- and low-dose intrathecal morphine for spinal fusion in children

BACKGROUND

The purpose of this prospective study was to assess the blood-sparing effect, the quality of analgesia, and the incidence of side-effects of a low-dose regime of intrathecal opioids (ITO) when compared with those of a high-dose regime in scoliosis surgery in children.

METHODS

Forty-six children were randomly included into one of the three groups to receive morphine 5 microg kg(-1) plus sufentanil 1 microg kg(-1) [low-dose intrathecal opioid (LITO)], morphine 15 microg kg(-1) plus sufentanil 1 microg kg(-1) [high-dose intrathecal opioid (HITO)] intrathecally, or no intrathecal opioid. Postoperative analgesia was provided by i.v. opioids. Intraoperative blood loss, postoperative quality of analgesia, opioid requirements, and the incidence of side-effects were recorded for 3 days.

RESULTS

Intraoperative blood loss was significantly reduced by ITOs [LITO: 41.4 (sd 18.8) ml kg(-1); HITO: 37.5 (6.9) ml kg(-1); control: 76.9 (15.3) ml kg(-1), P<0.001], with no difference between the two intrathecal opioid groups. Mean pain scores on the day of surgery were lower in both intrathecal opioid groups (LITO: 2.2 and HITO: 2.1) when compared with the control group (4.1, P<0.03) and opioid consumption was significantly decreased [LITO: 304.3 (65.0) microg kg(-1); HITO: 224.1 (51.8) microg kg(-1); control: 667.7 (89.5) microg kg(-1), P<0.002]. Side-effects of intrathecally administered opioids were similarly frequent in all groups.

CONCLUSIONS

Intrathecal administration of opioids significantly reduces blood loss and postoperative opioid demand, thereby showing side-effects comparable with the control group. These effects were already seen with the low-dose regimen and high dose did not further improve efficacy.

Fatal errors in nitrous oxide delivery

Nitrous oxide continues to be used frequently and the possibility of inadvertent fatal hypoxaemia resulting from technical errors with its administration still exists. A Medline analysis revealed only a few case reports over the last 30 years, and a closed claim analysis only reported 'claims involving oxygen supply lines' predating 1990. The aim of this study was to assess the frequency of nitrous oxide-related catastrophes during general anaesthesia in Germany, Austria, and Switzerland. As nitrous oxide-related anaesthesia casualties are rare but generally prosecuted, they almost invariably attract significant media attention. We scanned mass media archives from April 2004 until October 2006 for nitrous oxide-related disasters during general anaesthesia. This approach detected six incidents which were almost certainly nitrous oxide ventilation-related deaths. Searching non-scientific data bases demonstrates that severe incidents involving oxygen supply lines occurred after 1990, and may be much more frequent than previously thought.

A study of airway management using the ProSeal LMA laryngeal mask airway compared with the tracheal tube on postoperative analgesia requirements following gynaecological laparoscopic surgery

In a randomised double blind prospective study, we tested the hypothesis that postoperative pain is lower in patients who receive an ProSeal LMA laryngeal mask airway compared with a tracheal tube. One hundred consecutive female patients (ASA I-II, 18-75 years) undergoing laparoscopic gynaecological surgery were divided into two equal-sized groups for airway management with the ProSeal LMA or tracheal tube. Anaesthesia management was identical for both groups and included induction of anaesthesia using propofol/fentanyl, and maintenance with propofol/remifentanil, muscle relaxation with rocuronium, positive pressure ventilation, gastric tube insertion, dexamethasone/tropisetron for anti-emetic prophylaxis, and diclofenac for pain prophylaxis. All types of postoperative pain were treated using intravenous patient-controlled analgesia (PCA) morphine. Patients and postoperative staff were unaware of the airway device used. Data were collected by a single blinded observer. We found that pain scores were lower for the ProSeal LMA at 2 h and 6 h but not at 24 h. Morphine requirements were lower for the ProSeal LMA by 30.4%, 30.6% and 23.3% at 2, 6 and 24 h, respectively. Nausea was less common with the ProSeal LMA than with the tracheal tube at 2 h and 6 h but not at 24 h. There were no differences in the frequency of vomiting, sore throat, dysphonia or dysphagia. We conclude that postoperative pain is lower for the ProSeal LMA than the tracheal tube in females undergoing gynaecological laparoscopic surgery.

Postoperative nausea, vomiting, airway morbidity, and analgesic requirements are lower for the ProSeal laryngeal mask airway than the tracheal tube in females undergoing breast and gynaecological surgery

BACKGROUND

We test the hypothesis that the frequency of postoperative nausea and vomiting is similar for the ProSeal laryngeal mask airway (LMA) and the tracheal tube.

METHODS

Two hundred consecutive female patients (ASA I-II, 18-75 yr) undergoing routine breast and gynaecological surgery were divided into two equal-sized groups for airway management with the ProSeal LMA or tracheal tube.

RESULTS

Ventilation was better and airway trauma less frequent for the ProSeal LMA. For the ProSeal group, the time spent in the post-anaesthesia care unit was shorter (69 vs 88 min, P < 0.0001); fewer doses of tropisetron were required in the post-anaesthesia care unit (P < or = 0.001) and ward (P = 0.004); morphine requirements were lower in the post-anaesthesia care unit (6.0 vs 8.1 mg, P = 0.005) and ward (6.1 vs 8.9, P = 0.004); nausea was less frequent at all times (overall: 13% vs 53%, P < 0.0001); vomiting was less frequent at 2 h (4% vs 18%, P = 0.003) and 24 h (5% vs 19%, P = 0.004); and sore throat was less frequent at all times (overall: 12% vs 38%, P < 0.0001).

CONCLUSIONS

The ProSeal LMA reduced the absolute risk of postoperative nausea and vomiting by 40% (53-13%). In patients without the need for morphine, the ProSeal LMA reduced the absolute risk of postoperative nausea and vomiting by 23% (37-14%). We conclude that the frequency of postoperative nausea, vomiting, airway morbidity, and analgesic requirements is lower for the ProSeal LMA than the tracheal tube in females undergoing breast and gynaecological surgery.

Effect of total intravenous anaesthesia and balanced anaesthesia on the frequency of coughing during emergence from the anaesthesia

BACKGROUND

The effects of total intravenous anaesthesia (TIVA) and balanced anaesthesia (BAL) on coughing during emergence from the general anaesthesia have not yet been compared.

METHODS

Fifty patients, aged 18-60 yr, undergoing elective lumbar disk surgery were randomly allocated to undergo TIVA (propofol-remifentanil) or BAL (fentanyl-nitrous oxide-sevoflurane). Extubation was performed in the knee-elbow position, documented on video, and subsequently evaluated by blinded examiners.

RESULTS

There was no difference between TIVA and BAL patients with respect to patient characteristics, proportion of smokers, surgical time, or time of emergence. The median number of coughs was significantly lower in the TIVA group (1, range 0-9) than in the BAL group (4, range 0-20, P = 0.007). Mean maximal heart rate and mean maximal arterial pressure measured during emergence were also significantly lower in the TIVA group (P = 0.009 and P = 0.006, respectively).

CONCLUSIONS

During emergence from anaesthesia in the knee-elbow position, TIVA is associated with significantly less coughing and reduced haemodynamic response when compared with BAL.

Differential neurotoxicity of tricyclic antidepressants and novel derivatives in vitro in a dorsal root ganglion cell culture model

BACKGROUND AND OBJECTIVE

Tricyclic antidepressants are commonly employed orally to treat major depressive disorders and have been shown to be of substantial benefit in various chronic pain conditions. Among other properties they are potent Na+ channel blockers in vitro and show local anaesthetic properties in vivo. The present study aimed to determine their differential neurotoxicity, and that of novel derivatives as prerequisite for their potential use in regional anaesthesia.

METHODS

To directly test neurotoxicity in adult peripheral neurons, the culture model of dissociated adult rat primary sensory neurons was employed. Neurons were incubated for 24 h with amitriptyline, N-methyl-amitriptyline, doxepin, N-methyl-doxepin, N-propyl-doxepin, desipramine, imipramine and trimipramine at 100 mumol, and at concentrations correlating to their respective potency in blocking sodium channels.

RESULTS

All investigated substances showed considerable neurotoxic potency as represented in significantly decreased neuron numbers in cultures as compared to controls. Specifically, doxepin was more neurotoxic than amitriptyline, and both imipramine and trimipramine were more toxic than desipramine or amitriptyline. Novel derivatives of tricyclic antidepressants were, in general, more toxic than the parent compound.

CONCLUSIONS

Tricyclic antidepressants and novel derivatives thereof show differential neurotoxic potential in vitro. The rank order of toxicity relative to sodium channel blocking potency was desipramine < amitriptyline < N-methyl amitriptyline < doxepin < trimipramine < imipramine < N-methyl doxepin < N-propyl doxepin.

The metabolic role of IL-6 produced during exercise: is IL-6 an exercise factor?

For most of the last century, researchers have searched for a muscle contraction-induced factor that mediates some of the exercise effects in other tissues such as the liver and the adipose tissue. It has been called the ‘work stimulus’, the ‘work factor’ or the ‘exercise factor’. In the search for such a factor, a cytokine, IL-6, was found to be produced by contracting muscles and released into the blood. It has been demonstrated that IL-6 has many biological roles such as: (1) induction of lipolysis; (2) suppression of TNF production; (3) stimulation of cortisol production. The IL-6 gene is rapidly activated during exercise, and the activation of this gene is further enhanced when muscle glycogen content is low. In addition, carbohydrate supplementation during exercise has been shown to inhibit the release of IL-6 from contracting muscle. Thus, it is suggested that muscle-derived IL-6 fulfils the criteria of an exercise factor and that such classes of cytokines could be termed ‘myokines’.

Oxygen status of lung granulomas in Mycobacterium tuberculosis-infected mice

It is often assumed that Mycobacterium tuberculosis (Mtb)-induced granulomatous lesions, particularly those undergoing central caseation, are anoxic, and that the survival of Mtb in these lesions requires the integrity of its non-oxidative respiratory pathways. Using the hypoxia marker pimonidazole, we now provide immunohistochemical evidence that in the most frequently used animal model system of inbred mice Mtb-induced granulomas, even after more than one year of aerogenic infection, are not severely hypoxic. In contrast, chronic aerosol infection with M. avium strain TMC724 was associated with hypoxia surrounding necrotizing granuloma centres. Direct measurements of oxygen tension with a flexible microelectrode in mouse lungs chronically infected with Mtb disclosed a wide range of oxygen partial pressures in different parts of the lungs which, however, rarely approached the anoxic conditions consistently found in necrotizing tumours. We further show that an Mtb mutant, defective in nitrate reductase (narG) necessary for survival under anaerobic conditions in vitro, can persist in the lungs of chronically infected mice to a similar extent as wild-type Mtb. These findings have important implications for the use of the mouse model of Mtb infection in developing eradication chemotherapy and for evaluating putative mechanisms of chronic persistence and latency of Mtb.

Beatmung eines ungeschützten Atemwegs

BACKGROUND

Currently 30 chest compressions and 2 ventilations with an inspiratory time of 1 s are recommended during cardiopulmonary resuscitation with an unprotected airway, thus spending about 15% instead of 40% of resuscitation time on ventilation. Time could be gained for chest compressions when reducing inspiratory time from 2 s to 1 s, however, stomach inflation may increase as well.

METHODS

In an established bench model we evaluated the effect of reducing inspiratory time from 2 s to 1 s at different lower oesophageal sphincter pressure (LOSP) levels using a novel peak inspiratory-flow and peak airway-pressure-limiting bag-valve-mask device (Smart-Bag).

RESULTS

A reduction of inspiratory time from 2 s to 1 s resulted in significantly lower peak airway pressure with LOSP of 0.49 kPa (5 cm H2O), 0.98 kPa (10 cm H2O) and 1.47 kPa (15 cm H2O) and an increase with 1.96 kPa (20 cm H2O). Lung tidal volume was reduced with 1 s compared to 2 s. When reducing inspiratory time from 2 s to 1 s, stomach inflation occurred only at a LOSP of 0.49 kPa (5 cm H2O).

CONCLUSIONS

In this model of a simulated unprotected airway, a reduction of inspiratory time from 2 s to 1 s using the Smart-Bag resulted in comparable inspiratory peak airway pressure and lower, but clinically comparable, lung tidal volume. Stomach inflation occurred only at a LOSP of 0.49 kPa (5 cm H2O), and was higher with an inspiratory time of 2 s vs 1 s.

High concentration potassium permanganate eliminates protein and particle contamination of the reusable Classictm laryngeal mask airway

In this three-stage study, we test the hypothesis that supplementary cleaning with potassium permanganate > or =4 mg.l(-1) eliminates protein and particle contamination from the reusable Classic laryngeal mask airway. The first stage involved supplementary cleaning of 70 1 x 1 cm segments from deliberately contaminated laryngeal mask airways using potassium permanganate at 0, 2, 4, 8, 16, 32 and 64 mg.l(-1) and testing for protein staining. This showed that the lowest concentration required to eliminate protein contamination was 8 mg.l(-1). The second stage involved supplementary cleaning of 50 used laryngeal mask airways with either potassium permanganate 8 mg.l(-1) or saline and testing for protein staining. This showed that protein contamination was lower in the potassium permanganate group (p < 0.00001): all laryngeal mask airways in the control group and none in the potassium permanganate group were contaminated. The third stage involved scanning electron microscopic examination of 1 x 1 cm segments from three laryngeal mask airways used in the control group, three from the potassium permanganate group, plus three brand new laryngeal mask airways. The mean density of > or =1 mum surface particles was lower in the potassium permanganate 8 mg.l(-1) than the control group (21 vs. 121 .cm(-2), p < 0.0001) and was similar to brand new laryngeal mask airways (24 .cm(-2)). We conclude that supplementary cleaning with potassium permanganate 8 mg.l(-1) eliminates protein deposits from reusable laryngeal mask airways and reduces particle contamination to similar levels to brand new laryngeal mask airways.

Protein cross-contamination during batch cleaning and autoclaving of the ProSeal laryngeal mask airway

We tested the hypothesis that protein cross-contamination occurs during batch cleaning and autoclaving of a reusable extraglottic airway device, the ProSeal laryngeal mask airway. At the end of each day for 10 days, nine laryngeal mask airways that had been used for non-intra-oral surgery were cleaned and autoclaved alongside a new unused laryngeal mask airway. In addition, a new unused laryngeal mask airway underwent the same cleaning and autoclaving procedures in isolation. Protein staining was more frequently detected on the unused laryngeal mask airways that were processed by batch rather than in isolation (p < 0.01). Protein staining was detected on all unused laryngeal mask airways that were processed by batch, but none on those processed in isolation. Protein staining was more severe with the used compared with the unused laryngeal mask airways (p < 0.001). We conclude that protein cross-contamination of the laryngeal mask airway occurs during batch cleaning and autoclaving and recommend that reusable airway devices are cleaned in isolation.

Purification and characterization of a novel glucuronan lyase from Trichoderma sp. GL2

The filamentous fungus Trichoderma sp. GL2 produces an extracellular glucuronan lyase (GL) when grown on glucuronan as the sole carbon source. In this paper, we report the purification to electrophoretical homogeneity of this polysaccharide lyase by size exclusion chromatography and anion exchange chromatography. The purified GL, classified as an endopolyglucuronate lyase, is a monomer with an apparent molecular weight of 27 kDa and an isoelectric point of 6.95. Despite an inhibition of the activity when polysaccharide substrates were substituted by acetates, the enzyme was active toward glucuronans (acetylated or not) and ulvan, leading to various (4,5)-unsaturated products as oligoglucuronans (acetylated or deacetylated), highly acetylated low-molecular-weight (LMW) glucuronans, and LMW ulvans.

[Analgesia with remifentanil in spontaneously breathing patients undergoing brief but painful radiological procedures]

INTRODUCTION

Percutaneous transhepatic biliary drainage (PTBD) and stenting are very painful procedures in interventional radiology and require potent analgesia; employing remifentanil in spontaneously breathing patients may be one possible strategy.

PATIENTS AND METHODS

The study group was composed of 18 men and 2 women with a mean age of 63+/-10 (mean+/-SD) years. Pain intensity was measured with a VAS score before the procedure, after local anesthesia on the rib cage, after stenting and after the radiology procedure.

RESULTS

Remifentanil infusion (dosage: 0.12-0.30 microg/kg body weight/min) was infused throughout the entire radiology procedure according to physical status, past medical history, individual pain, and clinical assessment. During insufflation of 10l O(2)/min via a venturi mask, oxygen saturation did not fall below 96% at any time-point during the procedure. In the VAS score, we noted a decrease after starting the remifentanil infusion towards the end of procedure. All patients were able to move into bed without help. Postoperatively, no analgesics and no antiemetics were needed.

CONCLUSIONS

Employing a remifentanil infusion for brief interventional radiology procedures in palliative treatment of patients resulted in high patient and radiologist comfort.