Unnecessary interruptions of cardiac massage during simulated cardiac arrests

BACKGROUND AND OBJECTIVE

Cardiopulmonary resuscitation should not be interrupted until the return of spontaneous circulation or the decision to withhold further treatment. There are no data on how consistent in-hospital cardiopulmonary resuscitation is performed. Accordingly, the aim of the present study was to identify length and type of unnecessary interruptions in simulated cardiac arrests.

METHODS

The study was carried out in a patient simulator. A scenario of cardiac arrest due to ventricular fibrillation was used. Resuscitation teams consisted of three nurses, a resident and a staff physician. Using videotapes recorded during simulations, the activities of the teams were coded in 5-s intervals. Unnecessary interruptions were defined as any interruptions in cardiac massage of 10 s or more that were not caused by defibrillation or endotracheal intubation.

RESULTS

Twelve teams were studied. The total time of possible cardiac massage was 414 +/- 125 s. In each team at least one unnecessary interruption occurred (range 1-5). Interruptions mounted up to 65 +/- 40 s (range 20-155) or 16 +/- 10% (range 5-41) of the total time of possible cardiac massage. Failure to swiftly resume cardiac massage after an unsuccessful defibrillation accounted for 14 of 39 episodes and for 44 +/- 40% of the time of unnecessary interruptions. The debriefings revealed that participants had generally not noticed the unnecessary interruptions during the simulation.

CONCLUSIONS

The present study identified a significant amount of unnecessary interruptions in cardiac massage. These interruptions were not noticed by the health-care workers involved.

Observation of parity nonconservation in møller scattering

We report a measurement of the parity-violating asymmetry in fixed target electron-electron (Møller) scattering: A(PV)=[-175+/-30(stat)+/-20(syst)] x 10(-9). This first direct observation of parity nonconservation in Møller scattering leads to a measurement of the electron's weak charge at low energy Q(e)(W)=-0.053+/-0.011. This is consistent with the standard model expectation at the current level of precision: sin((2)theta(W)(M(Z))((-)MS)=0.2293+/-0.0024(stat)+/-0.0016(syst)+/-0.0006(theory).

Effect of inertia in Rayleigh-Bénard convection

We have investigated the influence of the Prandtl number on the dynamics of high Rayleigh number thermal convection. A numerical parameter study in a three-dimensional Rayleigh-Bénard configuration was carried out, where we varied the Prandtl number between 10(-3)< or =Pr< or =10(2). The Rayleigh number was fixed at a value of Ra=10(6). Our main focus lay on the question how the value of the Prandtl number affects the spatial structure of the flow. We investigated the functional dependence of the Nusselt number and the Reynolds number and compared our results with a recent theoretical approach of Grossmann and Lohse [J. Fluid Mech. 407, 27 (2000); Phys. Rev. Lett. 86, 3316 (2001)].

Corazonin promotes tegumentary pigment migration in the crayfish Procambarus clarkii

The undecapeptide corazonin (pGlu-Thr-Phe-Gln-Tyr-Ser-His-Gly-Trp-Thr-AsnNH(2)) elicits a retraction of erythrophore pigment granules and dispersion of leucophore pigment granules in the crayfish Procambarus clarkii. The effects are dose-dependent from 10(-10) to 10(-5)M. Influence on erythrophores is lower than that of Red Pigment Concentrating Hormone (RPCH), which is inactive on leucophores. Corazonin effects are partly blocked by an anti-corazonin antibody, and even less by an anti-RPCH antibody. Corazonin effects are completely suppressed by the calcium chelator BAPTA. Immunoreactive somata and fibers were identified in various regions of the eyestalk (medulla terminalis, medulla interna and medulla externa) with the anti-corazonin antibody. These results suggest the possible existence of a corazonin-like peptide in crustaceans.

Search for phase specific genes in the brain of desert locust, Schistocerca gregaria (Orthoptera: Acrididae) by differential display polymerase chain reaction

Differential display reverse transcriptase polymerase chain reaction (DDRT-PCR) in combination with semi-quantitative RT-PCR was used to compare differences in gene expression between the solitary and gregarious phase of Schistocerca gregaria. Twenty-six primer combinations were used, which produced 8 differential bands. Two out of the 8 differentials, one typical for the solitary and one for the gregarious phase, were further analyzed by semi-quantitative RT-PCR. The expression level of the solitary phase specific gene (SSG) was 2 times higher in solitary animals as compared to gregarious ones, while the gregarious specific gene (GSG) gave a 4-fold higher expression level in gregarious animals than in solitaries. Sequence analysis demonstrated that SSG does not belong to a known gene family, while the GSG belongs to the SPARC protein family.

The sex attractant pheromone of the oak processionary, Thaumetopoea processionea a field evaluation

The sex pheromone of Thaumetopoea processionea has recently been described as a mixture of different isomers with (Z,Z)-11,13-hexadecadien-1-yl acetate as the major active compound. First trials have shown that traps baited with this compound attract male moths in the field. In the present paper we evaluate the use of pheromone traps under practical aspects. The traps can be very well applied to monitor the pest, but the devices have to be installed in the upper crown of the oak trees. It is possible to determine the seasonal flight pattern of the moths. Results of field trials in Germany suggest that the traps can be used to roughly estimate the degree of infestation.

Search for peptidic molecular markers in hemolymph of crowd-(gregarious) and isolated-reared (solitary) desert locusts, Schistocerca gregaria

An HPLC analysis of hemolymph extracts was undertaken to uncover differences between desert locusts, Schistocerca gregaria, reared under either crowded or isolated conditions. Some differences in the chromatographic pattern could be detected. One of the major peaks in the hemolymph of crowd-reared adults was found to be a minor one in isolated-reared individuals, whereas other peaks increased after solitarization. The differences became even more pronounced after several generations of isolated rearing. The dominant chromatographic peak in hemolymph extracts of the crowd-reared animals was identified as a novel peptide with a molecular mass of 6080Da. Edman degradation in combination with enzymatic fragmentation and quadrupole-time of flight (Q-Tof) mass spectrometry revealed the full sequence: DNADEDTICVAADNKFYLYANSLKLYTCYNQLPKVYVVKPKSQCRSSLSDCPTS. This 54 aa-peptide is very abundant in hemolymph of crowd-reared adults. Its concentration in hemolymph amounts to 0.1mM. To uncover the function, its effects were investigated in several bioassays, so far without positive results. One of the other peaks differentially expressed in the individuals of the two phases was identified as SGPI-2 (MW=3794Da), which is a serine protease inhibitor in locusts.

Enzymatic (R)-phenylacetylcarbinol production in benzaldehyde emulsions

(R)-Phenylacetylcarbinol [(R)-PAC)] is the chiral precursor for the production of the pharmaceuticals ephedrine and pseudoephedrine. Reaction conditions were improved to achieve increased (R)-PAC levels in a simple batch biotransformation of benzaldehyde emulsions and pyruvate, using partially purified pyruvate decarboxylase (PDC) from the filamentous fungus Rhizopus javanicus NRRL 13161 as the catalyst. Lowering the temperature from 23 degrees C to 6 degrees C decreased initial rates but increased final (R)-PAC concentrations. Addition of ethanol, which increases benzaldehyde solubility, was not beneficial for (R)-PAC production. It was established that proton uptake during biotransformation increases the pH above 7 thereby limiting (R)-PAC production. For small-scale studies, biotransformations were buffered with 2-2.5 M MOPS (initial pH 6.5). High concentrations of MOPS as well as some alcohols and KCl stabilised PDC. A balance between PDC and substrate concentrations was determined with regards to ( R)-PAC production and yields on enzyme and substrates. R. javanicus PDC (7.4 U/ml) produced 50.6 g/l (337 mM) ( R)-PAC in 29 h at 6 degrees C with initial 400 mM benzaldehyde and 600 mM pyruvate. Molar yields on consumed benzaldehyde and pyruvate were 97% and 59%, respectively, with 17% pyruvate degraded and 24% converted into acetaldehyde and acetoin; 43% PDC activity remained, indicating reasonable enzyme stability at high substrate and product concentrations.

Effects of [His(7)]-corazonin on the phase state of isolated-reared (solitarious) desert locusts, Schistocerca gregaria

[His(7)]-corazonin is a neuropeptide produced in the pars lateralis of the brain. It is stored in the corpora cardiaca and probably released from there. The only well-documented effect in locusts is increased melanization of the cuticle. We investigated whether this hormone might also be causally related to changes in behavior and morphometrics that, like melanization, occur during crowding-induced gregarization. Solitary fourth-instar nymphs of Schistocerca gregaria (Forsk.) were injected thrice with 1 nmol [His(7)]-corazonin. After molting to the 5th stadium their behavioral phase state was measured in an arena assay and analyzed using multiple logistic regression analysis. The hormone was found not to induce behavioral phase changes. Upon reaching adulthood, morphometrics shifts occurred towards values typical for crowd-reared and regregarized animals. Our results thus indicate that [His(7)]-corazonin is not involved in behavioral gregarization but may participate in morphometrical phase change.

A comparison of phase-related shifts in behavior and morphometrics of an albino strain, deficient in [His(7)]-corazonin, and a normally colored Locusta migratoria strain

The albino Okinawa strain of Locusta migratoria is deficient in the neurohormone [His(7)]-corazonin. This peptide induces darkening of the cuticle, one of the typical features of gregarious locusts. As part of a broader study on the possible role of [His(7)]-corazonin in phase transition, we explored whether corazonin-deficiency might be associated with differences in behavior and morphometrics between albino and normal phenotypes of L. migratoria. Using a modification of the logistic-regression assay of behavioral phase state previously derived for Schistocerca gregaria, we found that there were strain dependent behavioral differences between crowd-reared nymphs of the albino Okinawa and the normally colored African strain, with no evidence of the albino strain being obligatorily solitarious. However, upon isolation, a shift towards more solitarious behavior occurs in both strains, even more profoundly in the Okinawa albinos. A shift could also be recorded in morphometrics. The conclusion is that the albino strain, although showing some solitarious features even when crowd-reared, is not, as has been suggested, obligatory solitarious and, as a consequence, the complete absence of corazonin is not sufficient to bring about the solitarious state.

Proteolytic breakdown of the Neb-trypsin modulating oostatic factor (Neb-TMOF) in the hemolymph of different insects and its gut epithelial transport

The degradation of the unblocked hexapeptide, trypsin modulating oostatic factor of the flesh fly Neobellieria (Sarcophaga) bullata (Neb-TMOF) was studied in vitro in the hemolymph of the lepidopteran Spodoptera frugiperda, the orthopteran Schistocerca gregaria and the dictyopteran Leucophaea maderae. The half-life in the different species varied from approximately 3min in L. maderae to approximately 25min in S. gregaria. Purification of the degradation products and ESI-Qq-oa-Tof mass spectrometry revealed the fragments Asn-Pro-Thr-Asn, Leu-His and Asn-Pro, which were the same in the hemolymph of all species. Except in Leucophaea, Neb-TMOF was cleaved in dipeptides starting from the C-terminus and the reaction could be, at least partially, inhibited by captopril. These observations suggest that a dipeptidase, which has very similar enzymatic properties as mammalian angiotensin converting enzyme (ACE) and which circulates in the hemolymph, apparently is involved in the breakdown of Neb-TMOF and might be a common but not a universal enzyme in insect hemolymph.The introduction of Neb-TMOF into the gut of S. gregaria with the help of a capillary tube (intubation) demonstrated that the intact peptide is able to cross the gut epithelium and to appear in the hemolymph compartment. Since [3H]-inulin, which is too large to cross cell membranes, was found to penetrate the gut walls at a measurable rate, the paracellular pathway might be also permeable to smaller peptides. There was indeed a clear correlation between the molecular weight of inulin, Neb-TMOF, and inositol and the rate of penetration of these compounds through the gut epithelium to the hemolymph. These are promising findings in view of a potential use of such peptides for insect control purposes.

Biotransformation of benzaldehyde into (R)-phenylacetylcarbinol by filamentous fungi or their extracts

Extracts of 14 filamentous fungi were examined regarding their potential for production of (R)-phenylacetylcarbinol [(R)-PAC], which is the chiral precursor in the manufacture of the pharmaceuticals ephedrine and pseudoephedrine. Benzaldehyde and pyruvate were transformed at a scale of 1.2 ml into PAC by cell-free extracts of all selected strains, covering the broad taxonomic spectrum of Ascomycota, Zygomycota and Basidiomycota. Highest final PAC concentrations were obtained with the extracts of Rhizopus javanicus and Fusarium sp. [78-84 mM (11.7-12.6 g/l) PAC within 20 h from initial substrate concentrations of 100 mM benzaldehyde and 150 mM pyruvate]. (R)-PAC was in about 90-93% enantiomeric excess. Rhizopus javanicus had the advantage of faster growth than Fusarium sp. Rhizopus javanicus mycelia were used as an example in a biotransformation process based on whole cells and benzaldehyde and glucose as substrates. The substrate pyruvate was generated through the fungal fermentation of glucose. Only 19 mM PAC (2.9 g/l) were produced within 8 h from 80 mM benzaldehyde. with evidence of significant benzyl alcohol production.

Continuous production of (R)-phenylacetylcarbinol in an enzyme-membrane reactor using a potent mutant of pyruvate decarboxylase from Zymomonas mobilis

The optimization of a continuous enzymatic reaction yielding (R)-phenylacetylcarbinol (PAC), an intermediate of the L-ephedrine synthesis, is presented. We compare the suitability of three pyruvate decarboxylases (PDC), PDC from Saccharomyces cerevisiae, PDC from Zymomonas mobilis, and a potent mutant of the latter, PDCW392M, with respect to their application in the biotransformation using acetaldehyde and benzaldehyde as substrates. Among these, the mutant enzyme was the most active and most stable one. The reaction conditions of the carboligation reaction were investigated by determining initial rate velocities with varying substrate concentrations of both aldehydes. From the resulting data a kinetic model was inferred which fits the experimental data with sufficient reliability to deduce the optimal concentrations of both substrates for the enzymatic process. The results demonstrate that the carboligation is most efficiently performed using a continuous reaction system and feeding both aldehydes in equimolar concentration. Initial studies using a continuously operated enzyme-membrane reactor gave (R)-PAC with a space-time yield of 81 g L(-1). d(-1) using a substrate concentration of 50 mM of both aldehydes. The yield was easily increased by cascadation of enzyme-membrane reactors. The new strategy allows the synthesis of (R)-PAC from cheap substrates in an aqueous reaction system. It thereby overcomes the limitation of by-product formation that severely limits the current fermentative process.

Mass spectrometric evidence for the deficiency in the dark-color-inducing hormone,

A factor present in the brain and corpus cardiacum responsible for the induction of dark colour in Locusta migratoria was recently isolated and identified from the corpora cardiaca of normally pigmented locusts. The purification of this factor, designated as [His7]-corazonin was monitored using an albino mutant from a laboratory colony of an Okinawa (Japan) strain. In this study, we provide unequivocal mass spectrometric evidence that the brain and the corpora cardiaca of this albino Locusta mutant are deficient in [His7]-corazonin. Previously, [His7]-corazonin was shown to be responsible for the induction of dark body colour patterns as observed in crowded locusts. Using nanoflow-liquid chromatography-mass spectrometry, we demonstrated that this dark colour-inducing hormone is, however, present in the corpora cardiaca of solitary locusts (Schistocerca gregaria). Arch.

Gonadotropins in insects: an overview

Control of gonad development in insects requires juvenile hormone, ecdysteroids, and a peptidic brain gonadotropin(s). Compared to vertebrates, the situation in insects with respect to the molecular structure of gonadotropins is far less uniform. Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) of vertebrates are glycoproteins that are synthezised in the hypothalamus and released from the anterior pituitary. They stimulate gonad development, the production of progesterone or of sex steroids (estrogens, androgens). None of the known insect gonadotropins is a glycoprotein, neither can they be grouped into a single peptide family. In Drosophila, two G-protein coupled receptors, structurally related to the mammalian glycoprotein hormone receptors, have been identified. Nothing is known about their natural ligands. The sex-steroids of insects are likely to be ecdysteroids (20E in females, E in males of some species). Some of the identified gonadotropins speed up vitellogenesis (locust OMP and some -PF/-RFamide peptides) or stimulate ecdysteroid production by the ovaries (locust-OMP and Aedes- OEH) or testis (testis ecdysiotropin of Lymantria). In flies, the only as yet identified gonadotropin is the cAMP-generating peptide of Neobellieria. The seeming absence of uniformity in gonadotropins in insects might be due to a multitude of factors that can stimulate ecdysteroid production and/or to the use of different bioassays. Arch.

Captopril, a specific inhibitor of angiotensin converting enzyme, enhances both trypsin and vitellogenin titers in the grey fleshfly Neobellieria bullata

A strong and constitutive angiotensin converting enzyme- or ACE-like activity was demonstrated in the hemolymph of the adult grey fleshfly Neobellieria bullata. In a competition assay, the N. bullata trypsin modulating oostatic factor (Neb-TMOF) was confirmed to be an in vitro substrate for this circulating Neb-ACE. Oral uptake of captopril, a selective and specific inhibitor of ACE, resulted in a complete phenotypic knockout of circulating ACE activity. When compared with control animals, captopril-fed female flies showed an increase in the liver meal-induced trypsin peak in the midgut and elevated levels of protein meal-induced yolk polypeptides in the hemolymph. The latter effect was not due to a slower vitellogenin uptake by the ovaries, because oocyte growth was not affected by the captopril treatment. The apparent synergism between the demonstrated ACE functionality and the previously reported effects of the oostatic peptide Neb-TMOF are discussed in the context of our recent finding that Neb-TMOF represents a prime candidate for being the first known in vivo substrate for circulating insect ACE. Arch.

End of the millenium--end of the single thoracic artery graft? Two thoracic arteries--standard for the next millenium? Early clinical results and analysis of risk factors in 1,487 patients with bilateral internal thoracic artery grafts

PURPOSE

CABG with bilateral IMA grafts (BIMA) can improve long-term results in cardiac morbidity and mortality. An enhanced incidence of bleeding and wound complications compared to patients with single IMA (SIMA) remains a matter of debate. The aim of the study was to compare the operative outcomes of patients who had undergone CABG with BIMA and SIMA in situ grafts, especially to identify patient-related risk factors, such as obesity, diabetes mellitus and age above 70 years.

METHODS

Out of a total of 5,144 patients operated on between January 1996 and September 1999, patients with isolated CABG (n = 3,671) with BIMA or SIMA were analyzed retrospectively. In the BIMA group, the patients' (n = 1,487) mean age was 64.0 years; mean EF was 62.1%. In the SIMA group (n = 2,184), the mean age was 65.4 years and mean EF 60.6% (n. s.). In the BIMA group, the right IMA was anterior of the aorta to the LAD, the left IMA to the lateral wall. In the SIMA group, the LAD was revascularisized with the left IMA. Additional bypasses were performed with vein grafts.

RESULTS

The 30-day lethality was 1.6% in the BIMA group, 1.7% in the SIMA group in patients under 70, and 4.1% (BIMA) and 4.0% (SIMA) in patients over 70 (p = n.s.). A significantly higher blood loss was observed in the BIMA group (BIMA 979+/-708 ml, SIMA 790+/-575 ml, p<0.05). The rethoracotomy rate due to bleeding was significantly higher in patients with BIMA (4.1%) compared to those with SIMA (2.5%, p<0.05). In patients with a body mass index (BMI) of less than 27, no significant difference could be found (SIMA 2.8%, BIMA 3.4%, p = n. s.). Patients with a BMI >27 showed a significantly higher rethoracotomy rate (SIMA 2.2%, BIMA 4.9%). A higher incidence of sternal instabilities could be observed in the BIMA group (4.2%, p<0.05). Diabetes mellitus could not be identified as an independent risk factor for sternal complications (SIMA 2.9%, BIMA 5.0%, p = n. s.). COUCLUSION: CABG using both IMA's can be performed in nearly all patients as a routine method with good clinical results and low mortality. Bleeding in the BIMA group within 48 hours was increased. BMI >27 could be identified as a risk factor for sternal complications, but not diabetes mellitus or age over 70 years.

In vitro degradation of the Neb-Trypsin modulating oostatic factor (Neb-TMOF) in gut luminal content and hemolymph of the grey fleshfly, Neobellieria bullata

The unblocked hexapeptidic Trypsin Modulating Oostatic Factor of the fleshfly, an inhibitor of both trypsin and ecdysone biosynthesis, resists very well proteolytic breakdown by enzymes present in the lumen of the gut of previtellogenic fleshflies. However, when incubated in hemolymph of adult flies, females and males, its half-life time is a mere 0.5 min. In hemolymph of last instar larvae, this value increases to about 1.5 min. Whereas PMSF, a potent inhibitor of serine proteases has no effect, captopril and lisinopril, both known to be specific inhibitors of mammalian angiotensin I converting enzyme (ACE), effectively inhibit TMOF breakdown in fly hemolymph. Digestion of Neb-TMOF by recombinant Drosophila AnCE on itself results in identical degradation products as with total hemolymph. In both cases ESI-Qq-oa-Tof mass spectrometry demonstrated the appearance of peptide fragments with the sequences NPTN, LH and NP. These observations not only confirm the reported presence of circulating ACE-like activity in flies but also strongly suggest that in flies this hemolymph ACE-like activity might be involved in the regulation of the oostatic activity as exerted by Neb-TMOF.