At least one in three people with Type 2 diabetes mellitus referred to a diabetes centre has symptomatic obstructive sleep apnoea

AIMS

To investigate the prevalence of symptomatic obstructive sleep apnoea in unselected patients with Type 2 diabetes referred to a tertiary diabetes clinic.

METHODS

In a cross-sectional design, all newly referred patients were offered a stepwise screening for obstructive sleep apnoea with: (1) The Berlin questionnaire; then, if indicative: (2) overnight home monitoring with the ApneaLink™ device. Patients with an apnoea-hypopnoea index ≥ 5/h were offered referral for diagnostic polygraphy and treatment initiation.

RESULTS

A total of 200 patients participated (61% men; age 59.6 ± 10.5 years, diabetes duration 8.3 ± 6.3 years and BMI 31.7 ± 6.7 kg/m²). According to the questionnaire, 106 patients showed 'high risk' of obstructive sleep apnoea, and 72 of these were referred to polygraphy based on ApneaLink screening corresponding to a prevalence of symptomatic obstructive sleep apnoea of 39%. Patients with symptomatic obstructive sleep apnoea had significantly higher BMI, poorer glycaemic control and lower plasma HDL cholesterol levels as compared with patients unlikely to have obstructive sleep apnoea. The groups were not different with respect to sex, age, diabetes duration, blood pressure, diabetic complications or medication use. In multiple regression analyses, age, BMI and HDL cholesterol levels were all significant, independent predictors of obstructive sleep apnoea.

CONCLUSIONS

At least one third of people with Type 2 diabetes referred to a diabetes clinic in Denmark has symptomatic obstructive sleep apnoea. Our data suggest higher age, a compromised plasma lipid profile and a more obese phenotype in patients with Type 2 diabetes who have obstructive sleep apnoea, highlighting the need to focus on screening and treatment of obstructive sleep apnoea in these patients.

Scintigraphic evaluation of rhBMP-2-biocoated implants reveals no ectopic bone formation

The main objectives of the study described below were of two-fold nature: (1) to examine if rhBMP-2-biocoated implants in a pig model could lead to ectopic bone formation and (2) if quantitative and/or qualitative differences could be found between adhesively and covalently bonded BMP II using the scintigraphic method. In order to examine these central questions, 26 Göttingen minipigs were allocated to three groups with a control group (n=7) and two study groups (n=9 each) receiving one of three implant types: (a) chromosulfuric acid treated titanium surface as control, (b) non-covalently bonded BMP-2, and (c) covalently bonded and immobilized rhBMP-2. Each animal received four barbell-shaped implants, one in the proximal and distal metaphysis of each femur. The scintigraphic analyses were conducted after four, eight, and 12 weeks postoperatively. The visual (qualitative) analysis failed to show ectopic bone formation in any of the three groups. The statistical analysis of the relative values for bone formation yielded no significant differences between the groups, although the limitation in the applied methods do not enable one to draw conclusions regarding the histomophometric results.

Detection of ubiquityl-calmodulin conjugates with a novel high-molecular weight ubiquitylprotein-isopeptidase in rabbit tissues

The selective degradation of many proteins in eukaryotic cells is carried out by the ubiquitin system. In this pathway, proteins are targeted for degradation by covalent ligation to ubiquitin, a highly conserved protein [1]. Ubiquitylated proteins were degraded by the 26S proteasome in an ATP-depended manner. The degradation of ubiquitylated proteins were controlled by isopeptidase cleavage. A well characterised system of ubiquitylation and deubiquitylation is the calmodulin system in vitro [2]. Detection of ubiquityl-calmodulin conjugtates in vivo have not been shown so far. In this article we discuss the detection of ubiquitin calmodulin conjugates in vivo by incubation with a novel high-molecular weight ubiquitylprotein-isopeptidase in rabbit tissues. Proteins with a molecular weight of ubiquityl-calmodulin conjugates could be detected in all organs tested. Incubation with ubiquitylprotein-isopeptidase showed clearly a decrease of ubiquitin calmodulin conjugates in vivo with an origination of unbounded ubiquitin. These results suggest that only few ubiquitin calmodulin conjugates exist in rabbit tissues.

Patients with severe muscle wasting are prone to develop hypoglycemia during fasting

The authors investigated whether hypoglycemia develops during 23 hours of fasting in patients with Duchenne dystrophy (7 patients), spinal muscular atrophy (4 patients), and congenital myopathy (2 patients), all with residual muscle mass <10% of body weight. All patients with spinal muscular atrophy and congenital myopathy and one patient with Duchenne dystrophy, but none of six healthy subjects, developed hypoglycemia. Skeletal muscle is an important source of gluconeogenic substrates during fasting. Hypoglycemia must be considered in patients with low muscle mass, especially during surgery and febrile episodes.

Expression patterns of cell-type-specific genes in Dictyostelium

Cell-type specific genes were recognized by interrogating microarrays carrying Dictyostelium gene fragments with probes prepared from fractions enriched in prestalk and prespore cells. Cell-type specific accumulation of mRNA from 17 newly identified genes was confirmed by Northern analyses. DNA microarrays carrying 690 targets were used to determine expression profiles during development. The profiles were fit to a biologically based kinetic equation to extract the times of transcription onset and cessation. Although the majority of the genes that were cell-type enriched at the slug stage were first expressed as the prespore and prestalk cells sorted out in aggregates, some were found to be expressed earlier before the cells had even aggregated. These early genes may have been initially expressed in all cells and then preferentially turned over in one or the other cell type. Alternatively, cell type divergence may start soon after the initiation of development.

Management of anaphylactic shock evaluated using a full-scale anaesthesia simulator

BACKGROUND

The diagnosis of an anaphylactic reaction during anaesthesia is not the first consideration for the anaesthetist and might be missed. The aim of this study was to describe anaesthetists' management of an anaphylactic reaction concerning diagnosing, treatment and application of anaesthesia crisis resource management (ACRM) in a full-scale anaesthesia simulator.

METHODS

Forty-two anaesthetists in teams of two attended training sessions with a critical incident of anaphylactic shock in a full-scale simulator. Trained observers from the study group evaluated the medical treatment according to a treatment sequence developed from the literature and graded the ACRM performance on a five-point scale where 1 is bad and 5 is best.

RESULTS

None of the teams made the correct diagnosis within 10 min and treatment according to the treatment sequence was not initiated. Only 6/21 teams considered the right diagnosis but first after hints from the instructor 15 min after the start of the incident. Evaluation of the use of the total ACRM concept (that is the use of all of the ACRM expressions seen in a total connection: called general impression) gave a median value of 2.0 with a range of (1-3).

CONCLUSION

Anaphylactic shock was difficult to diagnose and no structured plans were used for the treatment in the simulated incident in this study.

Functional characterization of the S. cerevisiae genome by gene deletion and parallel analysis

The functions of many open reading frames (ORFs) identified in genome-sequencing projects are unknown. New, whole-genome approaches are required to systematically determine their function. A total of 6925 Saccharomyces cerevisiae strains were constructed, by a high-throughput strategy, each with a precise deletion of one of 2026 ORFs (more than one-third of the ORFs in the genome). Of the deleted ORFs, 17 percent were essential for viability in rich medium. The phenotypes of more than 500 deletion strains were assayed in parallel. Of the deletion strains, 40 percent showed quantitative growth defects in either rich or minimal medium.

Anaesthetic implications of rigid spine syndrome

The perioperative management of a 14-year-old girl, suffering from the muscular disorder rigid spine syndrome, is presented. The anaesthetic implications with regard to possible difficult intubation, cardiac involvement, malignant hyperthermia, neuromuscular blocking agents, and postoperative recovery are discussed.

The ubiquityl-calmodulin synthetase system from rabbit reticulocytes: isolation of the calmodulin-binding second component and enzymatic properties

Ubiquitin-calmodulin ligase (uCaM synthetase: EC 6.3.2.21), which has been detected in all tissues so far examined, catalyzes the Ca2+-dependent reversible synthesis of ubiquityl-calmodulin which is not directed to degradation by the ATP-dependent 26-S protease [Laub, M. & Jennissen, H. P. (1997) Biochim. Biophys. Acta 1357, 173-191]. As has been shown in the preceding paper in this journal, the uCaM synthetase holosystem can be separated into two essential protein components: uCaM Syn-F1, a ubiquitin-binding protein belonging to the ubiquitin-activating enzyme family (E1) and uCaM Syn-F2 which bestows the reaction specificity leading to the covalent modification of calmodulin with ubiquitin. UCaM Syn-F2, which binds to calmodulin-Sepharose in a Ca2+-dependent manner, has been purified over 3500-fold in seven steps from rabbit reticulocytes and has a native molecular mass of approximately 620 kDa. It binds calmodulin with a Km of 5 microM and to uCaM Syn-F1, i.e. ubiquitin-activating enzyme (E1), with a Km of 3 nM. The maximal specific activity obtained in enriched uCaM Syn-F2 is 6-8 pkat/mg. The pH optimum of uCaM synthetase lies at pH 8.5. In kinetic experiments the Km values for 125I-ubiquitin and ATP/Mg2+ were determined to be 8 microM and 16 nM, respectively, for the uCaM synthetase holosystem. The existence of a third separable protein component of uCaM synthetase, as is the case in E1, E2, E3 systems, is very unlikely since affinity chromatography on calmodulin-Sepharose, two ion-exchange chromatography steps and finally a gel-filtration step failed to indicate any additional protein component essential for synthetase activity. We therefore propose a two-component model for uCaM synthetase. This model is also supported by simple hyperbolic velocity curves in kinetic experiments based on the variation of these two components. The data suggests that uCaM Syn-F2 is neither an E2 nor an E3 but evidently combines the properties of both, making the Ca2+-dependent uCaM synthetase the member of a group of two-component ubiquitin ligase systems.

The ubiquityl-calmodulin synthetase system from rabbit reticulocytes: isolation of the ubiquitin-binding first component, a ubiquitin-activating enzyme

Ubiquitin is often implicated as a specific tag for protein degradation via the ubiquitin system although only a limited number of physiological proteins have been shown to be degraded in their native tissues via this pathway in vivo. Ubiquitin may also, however, have other functions of a regulatory nature (non-catabolic ubiquitylation). The ubiquitylation of calmodulin appears to fall into this category. Ubiquitin is linked to free calmodulin in the presence of the second messenger Ca2+ by the enzyme ubiquitin-calmodulin ligase (uCaM synthetase: EC 6.3.2.21) and there is no evidence that this step is followed by degradation of calmodulin via the ATP-dependent 26-S protease. Due to a lack of natural substrates and sufficient tissue material, only a few components of the ubiquitin system have been obtained in truly homogeneous form from reticulocytes. We therefore decided to attempt this for the calmodulin ligase. The enzymic components of the uCaM synthetase system copurified over several steps and could be highly enriched by a novel sample displacement technique on an ion-exchange resin. A fractionation of the synthetase components by affinity chromatography on ubiquitin-Sepharose and calmodulin-Sepharose yielded two essentially inactive components: a ubiquitin-Sepharose binding fraction (uCaM Syn-F1) and a calmodulin-Sepharose binding fraction (uCaM Syn-F2). The full activity of uCaM synthetase can be reconstituted when these two fractions are reunited. uCaM Syn-F1 could then be separated from all other enzymes of ubiquitin metabolism and, employing the second component with the natural substrate calmodulin, could be purified over 3500-fold to homogeneity. The ability to catalyze its own thiol labile ubiquitylation identified it as a member of the ubiquitin-activating enzyme family (E1). The homogeneous preparation contained a single protein of molecular mass 213 +/- 21 kDa (mean +/- SEM) as determined by gel filtration. The molecular mass of the monomer was determined by electrospray ion mass spectrometry to 112,140 +/- 47 Da (mean +/- SD). N-terminal sequence analysis (20 amino acids) led to a single N-terminal peptide beginning at residue 57 of the known rabbit cDNA sequence. No ragged N-terminus was detected, as would be expected by the action of an aminopeptidase or other peptidases of low specificity. The monomer molecular mass calculated from the cDNA sequence (Arg57-Arg1058) is 111,975 Da, characterizing this enzyme from reticulocytes as a homodimer of 224 kDa.

Modulation of calmodulin function by ubiquitin-calmodulin ligase and identification of the responsible ubiquitylation site in vertebrate calmodulin

Calmodulin is the universal calcium modulator in eukaryotic cells. Its biological activity is closely regulated by the second messenger Ca2+. Previous studies in cell-free extracts [Laub, M. & Jennissen, H. P. (1997) Biochim. Biophys. Acta 1357, 173-191] have shown that calmodulin is reversibly ubiquitylated by ubiquityl-calmodulin synthetase (ubiquitin-calmodulin ligase, EC 6.3.2.21) in the presence of Ca2+ without being channeled to degradation by the 26S proteasome. As shown here monoubiquitylation strongly decreases the biological activity of calmodulin towards phosphorylase kinase by reducing its affinity approximately threefold and the maximal degree of activation approximately twofold. Thus, a structural clarification of the ubiquitylation site on calmodulin has become crucial for advancing our knowledge in this field on a molecular level. As demonstrated by sequence analysis and mass spectrometry of conjugates, the ubiquitylation site is located in the first Ca2+-binding loop of calmodulin and has the octapeptide structure -L-F-D-K21-D-G-D-G- with Lys21 being the ubiquitylated residue in vertebrate and other calmodulins. This catalytic recognition sequence is, however, not the only structural requirement for calmodulin ubiquitylation by ubiquityl-calmodulin synthetase. Removal of the 41 C-terminal amino acids (fourth Ca2+-binding loop) separated by several nanometers from Lys21 drastically decreases the affinity and reactivity of the synthetase for calmodulin, indicating a more extensive structural requirement for the substrate binding site i.e. binding recognition. This allows the enzyme to discriminate in a site-specific manner between two nearly identical catalytic recognition sites in vertebrate calmodulin of which the second site -V-F-D-K94-D-G-N-G- in the third Ca2+-binding loop is apparently not ubiquitylated by the synthetase.

Serum concentrations of lignocaine and its metabolite monoethylglycinexylidide during fibre-optic bronchoscopy in local anaesthesia

Fibre-optic bronchoscopy was performed in local anaesthesia using lignocaine. Serum concentrations of lignocaine and its active metabolite monoethylglycinexylidide (MEGX) were measured in 16 patients at regular intervals up to 120 min after administration. Lignocaine was administered as an aerosol in the upper respiratory tract and as a solution in the bronchial tree. The total dose of lignocaine ranged from 243 to 608 mg (2.4-8.0 mg kg-1 body weight). The dose of lignocaine given as an aerosol ranged from 163 to 508 mg (1.6-6.6 mg kg-1) and the dose given as a solution ranged from 60 to 180 mg (0.8-2.5 mg kg-1). The highest median serum lignocaine concentration, 10.5 mumol l-1, was measured 20 min after administration. None of the patients had toxic serum lignocaine levels (> 26 mumol l-1) or adverse effects. The highest median serum MEGX concentration, 1.7 mumol l-1, was measured 120 min after administration. The dose of lignocaine, expressed in mg per kg body weight correlated with serum lignocaine and serum MEGX (rs = 0.47 and rs = 0.39, respectively). Lignocaine is a clinically safe, local anaesthetic agent provided the total dose does not exceed 6-7 mg kg-1 body weight.

Treatment of ventricular fibrillation during anaesthesia in an anaesthesia simulator

BACKGROUND

To evaluate treatment of ventricular fibrillation (VF) occurring during anaesthesia and the use of a full-scale simulator, 80 anaesthetists in teams of two were attending a training session in the simulator Sophus.

METHODS

The sessions were recorded on videotape and reviewed with the anaesthetists afterwards. Time of treatment and the sequence were registered.

RESULTS

Onset time for VF was the starting point. Most of the subjects changed respiratory settings. Four teams did not change inspiratory oxygen and 17 teams did not turn off the vaporiser. Cardiac compression was initiated by all teams. DC-defibrillation was not used by two teams, with 38 of 40 teams defibrillating once, 37 twice and 29 teams three times. Adrenaline was administered by 30 of 40 teams.

CONCLUSION

There was very little consistency among the teams regarding treatment for VF according to accepted algorithms. An anaesthesia simulator could be a tool for training and it is a safe way of demonstrating for the anaesthetist that certain treatment algorithms and behaviour during critical incidents are the most effective.

Synthesis and decay of calmodulin-ubiquitin conjugates in cell-free extracts of various rabbit tissues

Calmodulin is the natural substrate for ubiquitin-ligation by the enzyme ubiquitin-calmodulin ligase (uCaM-synthetase; EC 6.3.2.21). The activity of this ligase is regulated by the binding of the second messenger Ca2+ to the substrate calmodulin, which increases the activity ca. 10-fold. Up till now, two components of the ligase could be identified: uCaM Syn-F1 and uCaM Syn-F2, the first of which binds to ubiquitin and the second which binds to calmodulin. Since the physiological role of this enzyme is still unclear, this study was designed to examine whether the activity of uCaM-Synthetase in 40,000 x g tissue supernatants correlates with the calmodulin content in the various tissues. In reticulocytes, spleen, erythrocytes, testis and brain, which are rich in uCaM synthetase, the tissue contents calculated on the basis of activity measurements were between 4-80-fold higher than in red and white skeletal muscle. These activities did not correlate with the respective calmodulin contents of the tissues indicating that other factors were determining these enzyme levels. A second aim was to gain information on the role of the ATP-ubiquitin-dependent proteolytic pathway in those tissues displaying uCaM synthetase activity. In the reticulocyte system which contains the classical ATP-ubiquitin-dependent proteolytic pathway as measured with 125I-BSA, no ubiquitin-dependent degradation of calmodulin could be detected. We therefore examined the other tissues of the rabbit with the substrate 125I-BSA and succeeded in finding a ubiquitin-independent ATP-dependent proteolytic activity in every case but no ubiquitin-dependent activity. The ubiquitin-independent activity was highest in smooth muscle and red skeletal muscle being ca. 3-4-fold higher than in lung and testis. In 50% of the tissue crude extracts the time curve of calmodulin ubiquitylation progressed through a maximum indicating a dynamic steady state based on conjugate synthesis and decay. If a ubiquitylation pulse of 30 min was followed in liver crude extracts by the addition of EGTA, which specifically inhibits ubiquityl-calmodulin synthesis, a half-life of calmodulin-conjugate decay of 15-20 min is observed. A similar conjugate half-life of ca. 30 min was observed after addition of EDTA excluding that conjugate decay is due to an ATP-dependent proteolytic process. Studying the decay of purified ubiquitin-125I-BH-calmodulin conjugates in cell-free reticulocyte extracts led to the discovery of an ATP-independent isopeptidase activity which splits ubiquitin-calmodulin conjugates without leading to detectable calmodulin fragments. The rapid decay of ubiquitin-calmodulin conjugates in tissue extracts can therefore be plausibly explained by a ubiquityl-calmodulin splitting isopeptidase activity.

[Autoimmune cytopenia in pernicious anemia]

Authors report on their 5 patients with pernicious anaemia whose autoimmunocytopenia was diagnosed at different times after the diagnosis and treatment of their original disease. All of the patients were women. They have found autoimmune thrombocytopenic purpura in two cases, agranulocytosis in two cases and autoimmune haemolytic anaemia in one case. They compare their patients with the cases of literature.

Molecular characterization of beta-thalassemia in Hungary

We have identified seven different beta-thalassemia mutations and one delta beta-thalassemia determinant (the Sicilian type) in 32 members of 17 Hungarian families. The most common mutation is the IVS-I-1 (G-->A) change; its high frequency is comparable to that observed in neighboring Czechoslovakia. Additional mutations are of Mediterranean origin. One rare mutation (initiation codon ATG-->GTG) was identified as an independent mutation because of the absence of known polymorphisms in the beta-globin gene. One new frameshift at codon 51 (-C) was observed in a single individual; hematological data were as expected for a beta zero-thalassemia heterozygosity.

Three different mask physiotherapy regimens for prevention of post-operative pulmonary complications after heart and pulmonary surgery

OBJECTIVE

An investigation into the incidence of post-operative complications after thoracic surgery with 3 different physiotherapy masks.

DESIGN

A prospective, consecutive, randomized comparison.

SETTING

Department of Thoracic and Heart Surgery at a University Hospital. The treatments were performed by experienced and specially trained physiotherapists.

PATIENTS

160 patients were evaluated. 60 patients undergoing heart surgery, 59 patients having pulmonary resection, and 41 patients with exploratory thoracotomy.

INTERVENTIONS

In each operative category the patients were treated with one of three face mask systems used in addition to routine chest physiotherapy. These were either continuous positive airway pressure (CPAP), positive expiratory pressure (PEP), or inspiratory resistance - positive expiratory pressure (IR-PEP).

MEASUREMENTS AND RESULTS

Post-operative pulmonary complications were assessed by forced vital capacity (FVC), arterial oxygen tension (PaO2), and chest X-ray examination, all measured pre-operatively and on the fourth and ninth post-operative day. The patients filled in a questionnaire expressing their opinion about their mask treatment. There was an equal decrease in FVC, FVC%, and PaO2, and equal frequency of atelectasis in the 3 mask treatments. More patients with the PEP mask favoured their system than did those with the other 2 systems.

CONCLUSION

There was no statistically significant difference between the treatments: continuous positive airway pressure (CPAP), positive expiratory pressure (PEP), and inspiratory resistance - positive expiratory pressure (IR-PEP) on post-operative complications. Any of the three treatments may be used as supplement to standard chest physiotherapy.

Spleen emptying and venous hematocrit in humans during exercise

The spleen may release pooled erythrocytes to the general circulation during strenuous conditions such as heavy exercise. Most of our knowledge of this reservoir function of the spleen derives from animal studies, and the splenic contribution to the circulating blood volume in humans has been regarded as unimportant. We recorded the erythrocyte content in the human spleen during graded bicycle exercise to maximal working capacity. In five normal adults 99mTc-labeled autologous erythrocytes were injected intravenously, and the subjects were placed on bicycles with the back against a gamma camera focusing on the spleen. During increasing exercise the splenic erythrocyte content decreased linearly, and at maximal work load it had been reduced to a mean of 34.2% (range 44-26%) of the initial count rate at supine rest. Concomitantly norepinephrine and epinephrine in plasma increased gradually, whereas neuropeptide Y increased only at maximal exercise. A rise in hematocrit from a mean of 44.6 to 48 was observed, but the autotransfusion of erythrocytes from the spleen only partly explains the rise in hematocrit during physical activity.

A ubiquityl-calmodulin synthetase that effectively recognizes the Ca(2+)-free form of calmodulin

Ubiquityl-calmodulin synthetase (uCaM-synthetase) activity as detected in reticulocyte lysate and the crude extracts of rabbit tissues [FEBS Lett. 294 (1991) 229-233] has been well characterized as being essentially Ca(2+)-dependent (-Ca2+/+Ca2+ activity ratio: 0.15-0.2). However, during the purification of this enzyme on ubiquitin-Sepharose the Ca(2+)-dependent activity is lost and an essentially Ca(2+)-independent enzyme (-Ca2+/+Ca2+ activity ratio: 1.0-1.5) is obtained which was purified 90-fold (uCaM-Syn F1) to a final specific activity of 0.32 pkat/mg. During the purification procedure a second protein factor (uCaM-Syn F2) was isolated that has no catalytic activity by itself but restores Ca2+ dependence to the uCaM-Syn F1 fraction (-Ca2+/+Ca2+ activity ratio: 0.1) and enhances the catalytic activity in uCaM-Syn F1 in the presence of Ca2+ over 40-fold. It is concluded that several (possibly interdependent) forms of uCaM-synthetase exist which display different substrate specificities for calmodulin.

Sublingual premedication with brotizolam

This randomized, double-blind and double-dummy study was carried out in order to compare the perioperative sedation after premedication with either brotizolam 0.25-0.50 mg sublingually or diazepam 5-10 mg orally. Sixty-two patients aged 18-60 years scheduled for minor gynaecological surgery in general anaesthesia were included. Assessments were: 1. auditory continued response time (ACRT); 2. coma scale; 3. anxiety scale; and 4. final patient questionnaire. One hour after premedication the brotizolam group was more sedated, based on ACRT (P < 0.01) and the coma scale (P < 0.05). The final questionnaire showed (P < 0.05) that the brotizolam group was more satisfied with the effect of the premedication. Seven hours after the premedication the ACRT scores in both groups were similar to those before premedication and all the patients could walk about freely. In conclusion, as a premedicant in outpatients sublingual brotizolam appears to be a good alternative to diazepam.

Ca(2+)-dependent ubiquitination of calmodulin in yeast

Recently we were able to show that calmodulin from vertebrates, plants (spinach) and the mold Neurospora crassa can be covalently conjugated to ubiquitin in a Ca(2+)-dependent manner by ubiquityl-calmodulin synthetase (uCaM-synthetase) from mammalian sources [R. Ziegenhagen and H.P. Jennissen (1990) FEBS Lett. 273, 253-256]. It was therefore of high interest to investigate whether this covalent modification of calmodulin also occurs in one of the simplest eukaryotes, the unicellular Saccharomyces cerevisiae. Yeast calmodulin was therefore purified from bakers yeast. In contrast to calmodulin from spinach and N. crassa it does not activate phosphorylase kinase. Crude yeast uCaM-synthetase conjugated ubiquitin Ca(2+)-dependently to yeast and mammalian (bovine) calmodulin. Yeast calmodulin was also a substrate for mammalian (reticulocyte) uCaM-synthetase. As estimated from autoradiograms the monoubiquitination product (first-order conjugate) of yeast calmodulin has an apparent molecular mass of ca. 23-26 kDa and the second-order conjugate an apparent molecular mass of ca. 28-32 kDa. Two to three ubiquitin molecules can be incorporated per yeast calmodulin. Experiments with methylated ubiquitin in the heterologous reticulocyte system indicate that, as with vertebrate calmodulins, only one lysine residue of yeast calmodulin reacts with ubiquitin so that the incorporation of multiple ubiquitin molecules will lead to a polyubiquitin chain. These results also indicate that the ability of coupling ubiquitin to calmodulin was acquired at a very early stage in evolution.

Ubiquitination of endogenous calmodulin in rabbit tissue extracts

Previously we were able to show that purified calmodulins from vertebrates, plants (spinach) and the mold Neurospora crassa can be covalently conjugated to ubiquitin in a Ca(2+)-dependent manner. It was therefore pertinent to answer the question if a tissue extract contains all the components necessary for the endogenous synthesis of ubiquityl calmodulin (uCaM). Therefore [125I]ubiquitin, ATP/Mg2+ and Ca2+ were added to tissue extracts enriched by a single ion exchange step. In such extracts of red blood cells, skeletal muscle and testis a novel ubiquitin conjugate of 27-29 kDa is formed. This novel band could be identified as ubiquityl-calmodulin by the following methods: (i) identical Rf-value of novel conjugate and standard uCaM in SDS-PAGE; (ii) Ca(2+)-dependent conjugate formation; (iii) Ca(2+)-dependent adsorption to fluphenazine-Sepharose; (iv) Ca(2+)-dependent mobility change of the novel conjugate during SDS-PAGE; and (v) inhibition of conjugate band formation by phosphorylase kinase. These experiments clearly demonstrate that ubiquityl calmodulin can be endogenously generated in enriched cellular extracts and strongly indicate that this reaction is of importance in vivo.

Role of small calibre chest tube drainage for iatrogenic pneumothorax

A 2 mm Teflon catheter was used as a chest tube in 28 patients with iatrogenic pneumothorax. Frequent aspirations through the catheter were performed in 16 of the patients. In the remaining 12 patients the catheter was connected to a one way flutter valve. The treatment was successful in 27 of the 28 patients--one patient required a large calibre chest tube. The mean drainage time was 48 hours. The small catheter technique is superior to the use of a large intercostal drain as it is much less traumatic and troublesome. The small calibre chest tube with a one way valve is recommended as a safe and easy technique.

[Midazolam and ketamine for rectal premedication and induction of anesthesia in children]

Fifteen healthy children 2-10 years old and scheduled for elective surgery, received midazolam 0.35 mg/kg body weight and atropine 0.025 mg/kg as rectal premedication about 35 min before the induction of anesthesia. The induction itself was carried out in a separate and quiet room next to the operating theatre by rectal administration of ketamine 10 mg/kg and midazolam 0.2 mg/kg. With the children breathing spontaneously, anesthesia was maintained by repetitive i.v. bolus injections of ketamine. The sedative and anticholinergic effects of the premedication were satisfactory. Induction of anesthesia was smooth. Consciousness was lost after 9-15 (mean 13) min. No significant adverse effects on hemodynamics or respiration were noted. Recovery from anesthesia was uneventful. No cases of rectal irritation or unpleasant dreams were reported. Post-operative analgesia was good. In conclusion, rectal administration of midazolam and atropine for premedication, followed by ketamine and midazolam for the induction of anesthesia, proved to be a pleasant, safe, and reliable method in pediatric anesthesia.

Lytic cocktail in children. Rectal versus intramuscular administration

The efficacy of the lytic cocktail (1 ml contains pethidine 28 mg, promethazine 7 mg, chlorpromazine 7 mg) administered intramuscularly or rectally as premedication was studied in 51 children aged 1-12 years who had minor elective otological surgery. One group received 0.05 ml/kg intramuscularly (maximum dose 2.0 ml) and the other 0.07 ml/kg per rectum (maximum dose 2.8 ml). Most were satisfactorily sedated before operation, but after operation the rectally premedicated children were less sedated, which was in agreement with lower plasma pethidine concentrations in this group. The rectal dose should be increased if prolonged postoperative sedation is desireable.

Endotoxemia and enhanced generation of oxygen radicals by neutrophils from patients undergoing cardiopulmonary bypass

Plasma endotoxin concentrations and oxidative burst response of peripheral blood polymorphonuclear leukocytes were examined in 12 patients undergoing coronary artery bypass. The measurements were made just before the operation, 5 minutes after removal of the aortic crossclamp, and 24 hours after the operation. Endotoxin was quantitated by a combination of a sensitive Limulus amebocyte lysate assay and rocket immunoelectrophoresis measuring picogram amounts of endotoxin. Peripheral blood neutrophils were purified by a two-step dextran sedimentation and metrizoate sodium Ficoll (Lymphoprep., Nyegaard, Oslo, Norway) centrifugation. The oxidative burst response of these cells was measured for their ability to generate superoxide anion and was determined by a cytochrome c reduction assay. Preoperatively, all the plasma samples except one were free of endotoxin. The endotoxin levels reached 100 pg/ml 5 minutes after removal of the aortic crossclamp, and except in one sample they had decreased 24 hours after the operation. Studies on the generation of superoxide by neutrophils showed a decline in the response 5 minutes after removal of the aortic crossclamp and an enhancement of the response to f-Met-Leu-Phe by cells obtained from 11 of 12 patients 24 hours postoperatively. In vitro addition of bacterial lipopolysaccharide to blood from healthy individuals also enhanced the superoxide response of the neutrophils. We conclude that during cardiopulmonary bypass the circulating blood is contaminated by endotoxin and the neutrophils are primed for enhanced generation of oxygen radicals. The released oxygen radicals may be involved in the tissue damage observed in these patients.

Rectal induction of anaesthesia in children. A comparison between ketamine-midazolam and halothane for induction and maintenance of anaesthesia

Thirty children were randomly allocated to one of three anaesthetic techniques. Rectal anaesthesia induction with a mixture of ketamine 10 mg.kg-1 BW and midazolam 0.2 mg.kg-1 BW and maintenance of anaesthesia with either intravenous ketamine or halothane were compared to induction and maintenance with halothane. Rectal induction was found reliable and useful. The frequency of side effects, the recovery time, and the time until the child could be discharged were similar in the groups maintained with halothane, whereas recovery was prolonged when intravenous ketamine was used for maintenance.

[A new formulation of etomidate in lipid emulsion--bioavailability and venous provocation]

In a prospective, randomized study of 16 volunteers, a new galenic formulation of the induction hypnotic etomidate in lipid emulsion was compared with the commercial form in propylene glycol (Hypnomidate). After 0.3 mg/kg etomidate plasma levels (HPLC) and hypnotic effects (visual EEG analysis) of both formulations were almost identical. Onset of action occurred after 41.6 s in the propylene glycol group (group I) and 35.6 s in the lipid emulsion group (group II). The hypnotic effect (greater than or equal to D0) lasted 7 min 20 s in group I and 6 min in group II. Plasma levels in group I decreased from 630 ng/ml after 2 min to 170 after 8 min and 37 after 130 min. With group II the plasma levels decreased from 770 ng/ml after 2 min to 150 after 8 min and 42 after 130 min (Fig. 1). In the propylene glycol experiment, 4 of 8 volunteers reported pain on injection. Within 7 days 4 persons developed phlebitis or thrombophlebitis. One showed signs of an allergic reaction (urticaria). With the new formulation of etomidate in lipid emulsion, neither venous sequelae nor allergic reactions were observed in any of the 8 volunteers (Table 2).

Ubiquitin-calmodulin conjugating activity from cardiac muscle

Enzyme activity capable of covalently linking ubiquitin to bovine calmodulin in an ATP-dependent manner has been detected in rabbit cardiac muscle demonstrating that this enzyme occurs not only in reticulocytes but also in other tissues and possibly all tissues and cells which contain calmodulin as intracellular Ca2+-acceptor protein. This is of special interest since a ubiquitin-dependent proteolytic activity could previously not be detected in cardiac muscle. The name ubiquityl-calmodulin synthetase [uCaM-synthetase, ubiquityl:calmodulin ligase (EC 6.3.?.?)] is therefore suggested for this enzyme. In crude cardiac muscle extracts uCaM-Synthetase displays a specific activity of 93 nUnits/mg in comparison to reticulocyte lysate with 270 nUnits/mg as measured by the fluphenazine-Sepharose affinity adsorbent test (FP-test). Analysis of the ubiquitination product (125I-uCaM) by polyacrylamide electrophoresis in the presence of SDS followed by autoradiography reveals a major double band with molecular masses of 27 and 29 kDa (mono-ubiquitination products) respectively. In addition two novel minor bands (17 and 20 kDa) of smaller molecular mass than the monoubiquitination products were detected. These are probably proteolytic breakdown products of uCaM. A model is suggested for a specific function of this synthetase in the Ca2+-dependent breakdown of calmodulin in vertebrate (eukaryotic) cells.

[The antagonistic effect of physostigmine on sedation by lormetazepam (author's transl)]

The purpose of this study was to determine the arousal effect of physostigmine after lormetazepam sedation on the human EEG. 12 male volunteers received 2 mg/kg bm lormetazepam and 30 minutes later physostigmine 2 mg preceded by atropine 1 mg. Generally an arousal effect of physostigmine could be clinically observed and more objectively demonstrated by reduced sleep stages in the vigilosomnogram (p less than 0.05). 2 volunteers did not fall asleep. 9 volunteers were awake 5-12 minutes after termination of physostigmine injection. 1 volunteer did not show any effect. Resedation and parasympathetic side effects did not occur. In earlier studies deep sleep stages after lormetazepam 1 or 2 mg/70 kg bm lasted 70 to 120 minutes. Physostigmine is recommended to counteract undesirable benzodiazepine induced sedation.

[Electroencephalographically determined sedative effects (vigilosomnography) of the new Thienodiazepin-derivate clotiazepam (author's transl)]

In a double blind, randomized clinical study eighteen volunteers received either placebo or 5 mg diazepam or 5 mg clotiazepam at three different times at an interval of one week. Beside other parameters which have been measured a 60-minute polygraphic EEG recording was made thirty minutes after administration of the drugs. The vigilosomnograms revealed clear and reliable differences between placebo and the two active substances and suggest a sedative effect of both substances at the dose level used. There was only a slight difference between the two active substances. 5 mg clotiazepam produced a slightly stronger sedation than 5 mg diazepam. However, the records of autonomic side effects and subjective statements regarding the patients' condition showed that clotiazepam is associated with less side effects than diazepam.

[The hypnotic effect of the new benzodiazepine derivative lormetazepam when given intravenously (author's transl)]

1. 7 groups of 3 healthy male volunteers each, at the age of 21--27 years received various doses of Lormetazepam (0.0635 to 4.0 mg/70 kg). -- 2. The drug was injected intravenously during 60 s. Before, during and up to 4 hours after the injections the EEG, eye-movements, ECG and respiration was recorded and blood pressures measured at given time intervals. -- 3. The vigilo-somnograms showed after the injections a change in the EEG-stages, indicating a reduction of alertness, transitions into reduced wakefulness or beginning stages of sleep. Corresponding to clinical signs one can speak with i.v. applied doses of 0.0635 to 0.5 mg/70 kg of tranquilizing, with 1 mg/70 kg of sedative and with 2--4 kg of hypnotic effects. There has been a good dosage-efficiency relation. -- 4. Side-effects or unwarranted symptoms have not been seen during the clinical observations.

[The effect of naloxone and levallorphane following fentanyl on the blood gases, EEG and psychodiagnostic tests (author's transl)]

After administration of fentanyl, 0.15 mg naloxone or levallorphan or placebo were given several times and in increased doses and at same intervals of time to six volunteers. The experiment has been done after the rules of a double blind study. Naloxone has shown its superiority to levallorphan. The study demonstrated a faster and better action of naloxone in the way of a return to initial conditions of respiratory frequency, blood gases, and EEG. The concentration and attention faculties after naloxone have become clearly better in contrary to the results after levallorphan. At the end of an anaesthetic procedure, the greatest care should be given to the patient. First of all effective antagonism of the respiratory depression should be obtained without concomitant sedative and psychomimetic effects. The use of antagonists with agonist properties to reverse respiratory depression due to a morphinomimetic drug is not justified and so naloxone should supplant levallorphan.

[The hypnotic effect of fentanyl and sulfentanil. An electro-encephalographic comparison (author's transl)]

1. Electroencephalographic activity was registered in healthy subjects before, during and 90 minutes after intravenous injections of sufentanil and fentanyl. 2. With a dosage of ratio of 1:10, i.e., 0.025 mg/70 kg body weight sufentanil: 0.25 mg/70 kg body weight fentanyl as well as 0.015 mg/70 kg body weight sufentanil: 0.15 mg/70 kg body weight fentanyl, sufentanil was hypnotically more potent from fentanyl. 3. Sufentanil acts more powerfully on the respiratory regulation than does fentanyl. Periods of apnoea occur more frequently but can be interrupted by external psychophysiological stimulation. 4. The evaluation of indices of certain EEG-waves, characterizing well defined electroencephalographic stages corresponding to the waking-sleeping-behaviour confirmed the visual over-all analysis of the EEG-stages. 5. Physiological observations on heartrate, systemic blood pressure, rapid eye movements during wakefulness, and slow eye movements during sleepiness showed no reliable differences between sufentanil and fentanil. The systematically documented symptoms and vegetative signs of subjects also showed neither differences nor side-effects.

[Meteorotropy of vasomotor cephalea]

During a period of 823 days (from 1st October 1971 to 31st December 1973), attacks of migraine, non-migraine vascular cephalea and cephalea due to other neighbouring disturbances strong enough to affect working capacity were studied in 4 subjects. 2152 pieces of data were collected. 2) Frequency was at a minimum in summer and peaked in spring and autumn. 3) Comparison with meteorological conditions points to a highly significant recrudescence of disturbances in cold, damp weather, and meteorological periodicity independent of biological (circadian) rhythms.