A randomized trial of automated intermittent ropivacaine administration vs. continuous infusion in an interscalene catheter.

BACKGROUND: Ultrasound-guided interscalene nerve block with ropivacaine as local anesthetic agent given as boluses or continuous infusion is the preferred pain management after major shoulder surgery. The use of automated intermittent boluses has been shown to be superior to continuous infusion in sciatic and epidural nerve block. HYPOTHESIS: Automated intermittent boluses reduce pain after major shoulder surgery. METHODS: Seventy patients aged 18-75 years, scheduled for major shoulder surgery under general anesthesia with interscalene nerve block were included in this randomized controlled trial. Patients were allocated to either automated intermittent boluses with 16 mg ropivacaine every 2 h combined with patient-controlled administration or to a conventional regimen of continuous infusion of 8 mg/h (4 ml/h) of ropivacaine combined with patient controlled administration (2 ml, lockout time 30 min). Pain (Visual Analog Scale, VAS) was assessed every 8 h postoperatively. RESULTS: Fifty-seven patients completed the study, 29 in the continuous infusion group and 28 in the automated intermittent bolus group. Shoulder arthroplasty was performed in 49 (86%) of the cases. There were no significant differences in VAS score from 8 to 48 h post-operatively. No significant difference in opioid usage was observed. The automated intermittent bolus group reported significantly less force on coughing and more hoarseness. A significantly lower volume of ropivacaine was used in the automated intermittent bolus group. CONCLUSION: Automated intermittent boluses did not reduce pain or rescue opioid consumption compared with continuous infusion of ropivacaine. The automated intermittent bolus group had significantly less force on coughing and more hoarseness.

Myalgic encephalomyelitis: International Consensus Criteria.

The label 'chronic fatigue syndrome' (CFS) has persisted for many years because of the lack of knowledge of the aetiological agents and the disease process. In view of more recent research and clinical experience that strongly point to widespread inflammation and multisystemic neuropathology, it is more appropriate and correct to use the term 'myalgic encephalomyelitis' (ME) because it indicates an underlying pathophysiology. It is also consistent with the neurological classification of ME in the World Health Organization's International Classification of Diseases (ICD G93.3). Consequently, an International Consensus Panel consisting of clinicians, researchers, teaching faculty and an independent patient advocate was formed with the purpose of developing criteria based on current knowledge. Thirteen countries and a wide range of specialties were represented. Collectively, members have approximately 400 years of both clinical and teaching experience, authored hundreds of peer-reviewed publications, diagnosed or treated approximately 50 000 patients with ME, and several members coauthored previous criteria. The expertise and experience of the panel members as well as PubMed and other medical sources were utilized in a progression of suggestions/drafts/reviews/revisions. The authors, free of any sponsoring organization, achieved 100% consensus through a Delphi-type process. The scope of this paper is limited to criteria of ME and their application. Accordingly, the criteria reflect the complex symptomatology. Operational notes enhance clarity and specificity by providing guidance in the expression and interpretation of symptoms. Clinical and research application guidelines promote optimal recognition of ME by primary physicians and other healthcare providers, improve the consistency of diagnoses in adult and paediatric patients internationally and facilitate clearer identification of patients for research studies.

Regulation of the receptor specificity and function of the chemokine RANTES (regulated on activation, normal T cell expressed and secreted) by dipeptidyl peptidase IV (CD26)-mediated cleavage.

CD26 is a leukocyte activation marker that possesses dipeptidyl peptidase IV activity but whose natural substrates and immunological functions have not been clearly defined. Several chemo-kines, including RANTES (regulated on activation, normal T cell expressed and secreted), have now been shown to be substrates for recombinant soluble human CD26. The truncated RANTES(3-68) lacked the ability of native RANTES(1-68) to increase the cytosolic calcium concentration in human monocytes, but still induced this response in macrophages activated with macrophage colony-stimulating factor. Analysis of chemokine receptor messenger RNAs and patterns of desensitization of chemokine responses showed that the differential activity of the truncated molecule results from an altered receptor specificity. RANTES(3-68) showed a reduced activity, relative to that of RANTES(1-68), with cells expressing the recombinant CCR1 chemokine receptor, but retained the ability to stimulate CCR5 receptors and to inhibit the cytopathic effects of HIV-1. Our results indicate that CD26-mediated processing together with cell activation-induced changes in receptor expression provides an integrated mechanism for differential cell recruitment and for the regulation of target cell specificity of RANTES, and possibly other chemokines.

Deficient cyclic adenosine 3',5'-monophosphate control in mutants of two genes of Neurospora crassa.

Strains of Neurospora crassa mutant in either of two genes, Crisp-1 (cr1) and Frost (fr), showed no increase of cyclic adenosine 3',5'-monophosphate (cyclic AMP) levels when subjected to several treatments which produce large increases of cyclic AMP in wild-type Neurospora. Evidently, the previously reported deficiencies of adenylate cyclase in these mutants were sufficient to block the normal increases. This fact suggests that both mutants could be used to help determine which control phenomena involve cyclic AMP and to interrupt the control of established cyclic AMP-regulated functions. Earlier studies had suggested an interdependence of the cyclic AMP level and the electric potential difference across the plasma membrane of Neurospora. Present experiments, therefore, employed several strains with the cr1 mutation to test for possible roles of cyclic AMP in recovery and oscillatory behavior of the Neurospora membrane potential. The results showed all such phenomena to be normal in the adenylate cyclase-defective strains, which demonstrates that variations of cyclic AMP are not obligatorily involved in the apparent control processes. Evidence is also presented that the induction of both glucose transport system II and the alternative oxidase do not require elevated cyclic AMP levels.

Regulation of fructose 2,6-bisphosphate levels in Neurospora crassa.

Both wild type and cr-1 mutant (adenylate cyclase and cyclic AMP-deficient) strains of Neurospora crassa contain fructose 2,6-bisphosphate at levels of 27 nmol/g dry tissue weight. This level decreases by about 50% in both strains upon depriving the cells of carbon or nitrogen sources for 3 h. An increase in cyclic AMP levels produced by addition of lysine to nitrogen-starved cells produced no increase in fructose 2,6-bisphosphate levels. Both strains respond to short-term addition of salicylate, acetate, or 2,4-dinitrophenol with an increase in fructose 2,6-bisphosphate. Thus, the above-described regulation of fructose 2,6-bisphosphate levels is cyclic AMP-independent. A suspension of the wild type produces a transient increase of fructose 2,6-bisphosphate in response to administration of glucose, whereas the mutant strain does not respond unless it is fed exogenous cyclic AMP. Substitution of acetate for sucrose as a sole carbon source for growth leads to a differential decrease in fructose 2,6-bisphosphate levels between the two strains: the wild type strain has 63% and the cr-1 mutant strain has 37% of the levels of fructose 2,6-bisphosphate on acetate as compared to sucrose-grown controls. This may be the basis for an advantage of cr-1 over wild type in growth on acetate. Thus, although most regulation of fructose 2,6-bisphosphate is cyclic AMP-independent, the levels can be regulated by a combination of carbon source and cyclic AMP levels.

Control of nucleotide and erythroascorbic acid pools by cyclic AMP in Neurospora crassa.

UDPglucuronic acid and erythroascorbic acid were identified in extracts of the fungus Neurospora crassa. The concentrations of these two compounds are estimated, in growing wild type N. crassa, to be about 0.10 and 0.28 mumol/ml of cell water, respectively. The pools of these two compounds are regulated by cyclic AMP in Neurospora, both being elevated in the cr-1, adenylate cyclase deficient mutant and both being lowered by exogenous cyclic AMP. The pools of these two compounds are also elevated on nitrogen deprivation. The pools of a large number of other nucleotides are not influenced by cyclic AMP. Possible relationships between the metabolism of UDPglucuronic acid and erythroascorbic acid are discussed. It was found that exogenous cyclic AMP was much more effective in influencing cultures grown at 30-37 degrees C than those grown at 25 degrees C. We suggest that higher temperatures may render Neurospora more permeable to a variety of different compounds.

Stoichiometry of H+/amino acid cotransport in Neurospora crassa revealed by current-voltage analysis.

Coupling of ions to the uptake of neutral and basic amino acids via a general amino acid transport system (System II), was studied in a mutant of Neurospora crassa (bat mtr) which lacks other transport systems for these solutes. All amino acids tested--including ones bearing no net charge--elicited rapid membrane depolarization, as expected for ion-coupled transport. (Since amino acid transport in Neurospora is not dependent on extracellular Na+ or K+, the associated ion is presumed to be H+.) Although the 14C-labeled amino acid fluxes through System II are largely independent of the identity of the amino acid, the depolarization caused by basic amino acids (L-lysine and L-ornithine) is 60-70% greater than that for neutral amino acids (e.g. L-leucine). This difference is consistent with a constant H+/amino acid stoichiometry of 2, the extra charge for lysine and ornithine being that on the amino acid itself, so that the charge ratio basic:neutral amino acids is 3:2. When actual membrane charge flow associated with amino acid uptake was compared with measured 14C-labeled amino acid influx, ratios of 2.07 charges/mol L-leucine and 3.40 charges/mol L-lysine were obtained, again in accord with a constant translocation stoichiometry of 2H+/amino acid. The advantages of this electrical method for estimating H+/solute stoichiometry in cotransport are discussed in relation to more familiar methods.

Rapid isolation of Escherichia coli minicells by glass-fiber filtration: study of plasmid-coded polypeptides.

A filtration technique is described to purify Escherichia coli chi 1488 minicells much more rapidly than the usual method involving sucrose gradient centrifugation, and to produce minicells that have not been subjected to osmotic stress. The minicells so prepared are metabolically active as indicated by the in vivo incorporation of [35S]methionine into plasmid-coded polypeptides.

Very low ATP/ADP ratios with aging of the natural death senescence mutant of Neurospora crassa.

The natural death (nd) mutant of the fungus Neurospora crassa, unlike the wild-type, undergoes an aging process, which leads to the cessation of growth. It is shown here that the ATP/ADP ratio of the mutant declines with age to about 3:1 whereas other strains of Neurospora in the same growth medium maintain ratios of about 8 to 9:1. The decline in ATP/ADP ratio is not caused by the cessation of growth of the mutant. The results suggest, rather, that the cessation of growth may be caused, in part or in whole, by the defect in energy metabolism that produces the low ATP/ADP ratio. They support the hypothesis that defects in mitochondrial energy metabolism may be an important contributing factor to the aging process.

Lambda/plasmid vector construction by in vivo cre/lox-mediated recombination.

Lambda/plasmid hybrid vectors have been previously constructed in which the plasmid sequences are separated from flanking lambda arms by lox sites. The lox sequence is the substrate of Cre-mediated site-specific recombination, allowing easy excision of plasmid sequences (automatic subcloning). We have developed a simple procedure to construct other such lambda hybrid vectors using in vivo cre/lox-mediated recombination to exchange new plasmids for plasmids previously incorporated into lambda/plasmid hybrids. Because hybrid vectors both with and without lacZ alpha plasmid sequences are available, producing either blue or clear plaques, respectively, the new lambda hybrid vectors can be distinguished from the parental hybrids by blue/clear plaque screening. This procedure has been successfully used to construct ten hybrid vectors. It generates new lambda/plasmid hybrid vectors, without ligation or lambda packaging, which retain the property of automatic subcloning.

Effects of Schistocephalus solidus infection on brain monoaminergic activity in female three-spined sticklebacks Gasterosteus aculeatus.

The three-spined stickleback Gasterosteus aculeatus is an intermediate host of the tapeworm Schistocephalus solidus. Changes in predator avoidance, foraging and shoaling behaviour have been reported in sticklebacks infested with S. solidus, but the mechanisms underlying parasite-induced behavioural changes are not understood. Monoamine neurotransmitters are involved in the control of behaviour and central monoaminergic systems are sensitive to various stressors. Thus, the behavioural effects of S. solidus infestation might be a reflection of changes in brain monoaminergic activity in the stickleback host. The concentrations of 5-hydroxytryptamine (5-HT), dopamine (DA), norepinephrine (NE) and their metabolites 5-hydroxy-indoleacetic acid (5-HIAA), homovanilic acid (HVA) and 3-methoxy-4-hydroxyphenylglycol (MHPG) were measured in the telencephalons, hypothalami and brainstems of parasitized and non-parasitized female sticklebacks held in the laboratory. The ratios of 5-HIAA:5-HT were significantly elevated in both the hypothalami and brainstems of infected sticklebacks. The concentrations of 5-HT and NE were significantly reduced in the telencephalons of infected fish as compared with controls, but there was no elevation of metabolite concentrations. The results are consistent with chronic stress in infected fish, but may also reflect other alterations of neuroendocrine status resulting from parasite infection.

Elevated nitric oxide/peroxynitrite mechanism for the common etiology of multiple chemical sensitivity, chronic fatigue syndrome, and posttraumatic stress disorder.

Various types of evidence implicate nitric oxide and an oxidant, possibly peroxynitrite, in MCS and chemical intolerance (CI). The positive feedback loops proposed earlier for CFS may explain the chronic nature of MCS (CI) as well as several of its other reported properties. These observations raise the possibility that this proposed elevated nitric oxide/peroxynitrite mechanism may be the mechanism of a new disease paradigm, answering the question raised by Miller earlier: "Are we on the threshold of a new theory of disease?"

Carcinogens induce genetic tandem duplications in Salmonella.

Extensive studies have shown that chemical carcinogenesis involves an initiation-promotion pattern. A gene amplification model of carcinogenesis predicts that initiation involves induction of a genetic tandem duplication. We use a system developed by Anderson and Roth to select for tandem duplication of the histidine operon of Salmonella typhimurium by selection for resistance to 3-amino-1,2,4-triazole. Evidence reported here shows that, consistent with prediction, 10 carcinogens are all active in inducing tandem duplications. Two toxic noncarcinogens show little or no activity under the conditions used in inducing tandem duplication but azide, a mutagenic noncarcinogen, did show some activity. 9 types of evidence now support the gene amplification initiation-promotion model of carcinogenesis.

Induction of genetic tandem duplications in Salmonella by polycyclic aromatic hydrocarbon and amine carcinogens.

6 polycyclic aromatic hydrocarbon or similar amine carcinogens were tested as inducers of genetic tandem duplications in a rough strain of Salmonella typhimurium. When metabolically activated by rat-liver microsomes, all 6 were active in inducing genetic tandem duplications, yielding from over 3 times to almost 14 times as many tandem duplicants per viable bacterium as did concurrent uninduced control cultures. These results extend the number and chemical diversity of carcinogens shown to induce genetic duplications in bacterial tester systems. We suggest that polycyclic hydrocarbon carcinogens may act in carcinogenesis by inducing genetic duplications or other genetic rearrangements. Duplication induction may be a useful genetic endpoint for screening potential carcinogens.

Deoxyribonucleoside triphosphate pools in Neurospora crassa: effects of histidine and hydroxyurea.

An effective HPLC method for detecting deoxyribonucleoside triphosphates in hyphae from the fungus Neurospora crassa has been developed. In rapidly growing cells the nucleotide levels vary from 11.8 pmoles/micrograms DNA for dGTP to 24.2 pmoles/micrograms DNA for dTTP. These levels fall by approximately one half in stationary-phase cultures but the ratio of each pool to dGTP remains the same. The dNTP pools in conidia are at least 5-fold lower than in rapidly growing cells. The pool sizes are the same in static and shaking cultures. When the ribonucleotide reductase inhibitor, hydroxyurea (30 mM), is added to rapidly growing cultures, DNA synthesis is stopped and the dGTP pool is reduced by 39%, while the size of the other pools remains the same. In the presence of 11 mM histidine, DNA synthesis is also stopped and the size of the dGTP pool reduced by 46% while the deoxypyrimidine pools are somewhat increased. This suggests that the toxicity of excess histidine in Neurospora may be due to its ability to interact with the ribonucleotide reductase, inactivating the enzyme. Histidine may react with the free radical at the active site, as does hydroxyurea.

Corporate cost of occupational accidents: an activity-based analysis.

The systematic accident cost analysis (SACA) project was carried out during 2001 by The Aarhus School of Business and PricewaterhouseCoopers Denmark with financial support from The Danish National Working Environment Authority. Its focused on developing and testing a method for evaluating occupational costs of companies for use by occupational health and safety professionals. The method was tested in nine Danish companies within three different industry sectors and the costs of 27 selected occupational accidents in these companies were calculated. One of the main conclusions is that the SACA method could be used in all of the companies without revisions. The evaluation of accident cost showed that 2/3 of the costs of occupational accidents are visible in the Danish corporate accounting systems reviewed while 1/3 is hidden from management view. The highest cost of occupational accidents for a company with 3.600 employees was estimated to approximately US$ 682.000. The paper includes an introduction regarding accident cost analysis in companies, a presentation of the SACA project methodology and the SACA method itself, a short overview of some of the results of the SACA project and a conclusion. Further information about the project is available at http://www.asb.dk/saca.

Common etiology of posttraumatic stress disorder, fibromyalgia, chronic fatigue syndrome and multiple chemical sensitivity via elevated nitric oxide/peroxynitrite.

Three types of overlap occur among the disease states chronic fatigue syndrome (CFS), fibromyalgia (FM), multiple chemical sensitivity (MCS) and posttraumatic stress disorder (PTSD). They share common symptoms. Many patients meet the criteria for diagnosis for two or more of these disorders and each disorder appears to be often induced by a relatively short-term stress which is followed by a chronic pathology, suggesting that the stress may act by inducing a self-perpetuating vicious cycle. Such a vicious cycle mechanism has been proposed to explain the etiology of CFS and MCS, based on elevated levels of nitric oxide and its potent oxidant product, peroxynitrite. Six positive feedback loops were proposed to act such that when peroxynitrite levels are elevated, they may remain elevated. The biochemistry involved is not highly tissue-specific, so that variation in symptoms may be explained by a variation in nitric oxide/peroxynitrite tissue distribution. The evidence for the same biochemical mechanism in the etiology of PTSD and FM is discussed here, and while less extensive than in the case of CFS and MCS, it is nevertheless suggestive. Evidence supporting the role of elevated nitric oxide/peroxynitrite in these four disease states is summarized, including induction of nitric oxide by common apparent inducers of these disease states, markers of elevated nitric oxide/peroxynitrite in patients and evidence for an inductive role of elevated nitric oxide in animal models. This theory appears to be the first to provide a mechanistic explanation for the multiple overlaps of these disease states and it also explains the origin of many of their common symptoms and similarity to both Gulf War syndrome and chronic sequelae of carbon monoxide toxicity. This theory suggests multiple studies that should be performed to further test this proposed mechanism. If this mechanism proves central to the etiology of these four conditions, it may also be involved in other conditions of currently obscure etiology and criteria are suggested for identifying such conditions.

Elevated, sustained peroxynitrite levels as the cause of chronic fatigue syndrome.

The etiology of chronic fatigue syndrome (CFS) has been both obscure and highly contentious, leading to substantial barriers to both clear diagnosis and effective treatment. I propose here a novel hypothesis of CFS in which either viral or bacterial infection induces one or more cytokines, IL-1beta IL-6, TNF-alpha and IFN-gamma. These induce nitric oxide synthase (iNOS), leading to increased nitric oxide levels. Nitric oxide, in turn, reacts with superoxide radical to generate the potent oxidant peroxynitrite. Multiple amplification and positive feedback mechanisms are proposed by which once peroxynitrite levels are elevated, they tend to be sustained at a high level. This proposed mechanism may lower the HPA axis activity and be maintained by consequent lowered glucocorticoid levels. Similarities are discussed among CFS and autoimmune and other diseases previously shown to be associated with elevated peroxynitrite. Multiple pharmacological approaches to the treatment of CFS are suggested by this hypothesis.

[Poisoning with a reversible and selective monoaminooxidase inhibitor]. / Forgiftning med en reversibel og selektiv monoaminooxydasehaemmer.

Two cases of poisoning with moclobemide are presented. Moclobemide is a reversible inhibitor of the monoamine oxidase type A (RIMA). Intoxication with moclobemide is according to previously published case stories benign. Both patients described presented severe symptoms, such as convulsions, coma, muscle rigidity and respiratory failure. One of the patients, a 37-year-old woman, also suffered cardiovascular collapse and elevated body temperature (more than 41.9 degrees C), which was treated successfully with dantrolene and norepinephrine. The symptoms match the diagnostic criteria for serotonin syndrome. The possible reasons why the two patients suffered life-threatening complications and the treatment of serotonin syndrome are discussed.