First analysis of the proteome in two nematomorph species, Paragordius tricuspidatus (Chordodidae) and Spinochordodes tellinii (Spinochordodidae).

The proteome of most parasite species is currently unknown. Hairworms (Nematomorpha), 300 species distributed around the world, are parasitic in arthropods (mainly terrestrial species) when juveniles, but they are free-living in aquatic environments when adult. Most aspects of their systematics and biology are currently unknown. The aim of this paper was (i) to report a novel and reproducible protocol for the analysis of the proteome of hairworms using two-dimensional gel electrophoresis (2-DGE) and mass spectrometry (matrix laser desorption ionization-time of flight mass spectrometry (MALDI-TOF)) and (ii) to determine the level of proteomic divergence between two sympatric but taxonomically unrelated nematomorph species in the adult stage, Paragordius tricuspidatus Dufour (Nematomorpha, Gordiidae) and Spinochordodes tellinii Camerano (Nematomorpha, Gordiidae). In total, 689 protein spots were observed for P. tricuspidatus, 575 for S. tellinii. Only 36.2% spots were shared between the two species. Quantitative analysis of the proteins which are common to both parasite species reveals substantial differences in the pattern of protein expression. These results suggest a rapid evolutionary divergence between these two nematomorph families. Also, to test the value of our MALDI-TOF protocol, we used Actin-2 (Act-2), a protein highly conserved in the course of evolution. Peptide mass fingerprint (PMF) data obtained for Act-2 of P. tricuspidatus and S. tellinii suggest a very high homology with Act-2 of different worms species belonging to the Bilateria phylum (Annelida and Nematoda) and more specifically to Lumbricus terrestris (Annelida, Lumbricidae) and Caenorhabditis elegans (Nematoda, Rhabditidae). We discuss our results in relationship with current ideas concerning the use of proteomics in systematics.     

Opposite effects of internal globus pallidus stimulation on pallidal neurones activity.

Besides clinical efficacy, the mechanisms of action of deep brain stimulation (DBS) are still debated. To shed light on this complex issue, we have taken the opportunity to record the response of globus pallidus internus (GPi) neurones to 100 Hz stimulations in a case of Lesch-Nyhan syndrome (LNS) where four pallidal electrodes were implanted. Three types of response were observed, 2/19 neurones were unaffected by DBS. About 7/19 neurones were inhibited during DBS stimulation and 10/19 neurones were excited during DBS stimulation. Both effects ceased when DBS was turned off. Inhibited neurones were situated lower that exited ones on the trajectory (1.25 and 4.65 mm above the center of GPi respectively). These observations suggest that locally DBS induces a reversible inhibition of neurone firing rate while at the same time distantly exciting the main afferents to and/or efferents from the GPi. Both actions would result in a strong GPi inhibition that does not preclude increased outflow from the GPi.     

Baseline heart rate may predict hypotension after spinal anesthesia in prehydrated obstetrical patients

PURPOSE: Hypotension is the most frequent complication of spinal anesthesia in pregnant patients. This study was designed to identify patients at risk for postspinal hypotension based on preoperative vital signs before and after an orthostatic challenge. METHODS: Forty healthy women scheduled for elective Cesarean section were enrolled in this prospective trial. Blood pressure (BP) and heart rate (HR) were recorded with the patient in the lateral supine position and after standing up. After a bupivacaine spinal anesthetic, BP was obtained every two minutes for 30 min. Ephedrine treatment was administered based on the degree of hypotension observed. Hemodynamic parameters were correlated to ephedrine requirements (Spearman's rank order correlation). RESULTS: There was a significant correlation in baseline maternal HR and ephedrine requirements (P=0.005). The degree of orthostatic changes in mean arterial BP and HR did not correlate with postspinal hypotension. CONCLUSIONS: Baseline HR may be predictive of obstetric spinal hypotension. Higher baseline HR, possibly reflecting a higher sympathetic tone, may be a useful parameter to predict postspinal hypotension.     

Die Insuffizienz der intraabdominellen Infektabwehr bei der eitrigen Peritonitis — Folge einer gestörten Fremdkörperopsonierung

Summary Despite a high concentration of serum proteins and intact phagocytes peritonitis exudates contain a large number of viable, pathogenic bacteria. The reason for this biological paradox is unknown. Our investigations reveal a pronounced defect in humoral opsonization of foreign particles in peritonitis exudate. We evaluated a modified chemiluminescence system allowing the determination of opsonic activity in serum and exudate. In serum we found a close correlation between opsonic activity and immunologically measurable levels of C₃-complement and IgG. In purulent peritonitis exudates, however, the actual opsonizing activity was much less than expected according to the opsonin concentrations. We found a pronounced difference between immunologically determined opsonin levels and impaired opsonic function. Employing crossed immunoelectrophoresis massive C₃-splitting into smaller fragments could be demonstrated in peritonitis exudates. In these exudates we found very high concentrations of granulocyte proteolytic (elastase) and oxidative (myeloperoxidase) enzymes which may lead to a functional destruction of opsonins followed by impaired opsonization in peritonitis exudate. The great number of bacteria and foreign particles in addition can cause a pronounced physiological consumption of complement components. The almost complete breakdown of intact C₃-complement in intraabdominal exudate explains the deficient host defence in patients with severe peritonitis.

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Abkürzungsverzeichnis CL Chemilumineszenz - IgG Immunglobulin G - OK Opsonierungskapazität     

Interpretation of antitoxoplasma antibody findings

Between reactions assessing one class of immunoglobulins and reactions detecting all serum immunoglobulins comprehensively such as CFT, there is, as might be expected, a very poor quantitative correlation and thus in individual sera the result of one reaction cannot be reliably added to the result of another (CFT:ELISA/IgG). Even the correlation between reactions focused on the same Ig class (ELISA/IgG: IFT/IgG) is no better. Among reactions assessing specific IgM we consider ELISA/IgM better than IFT/IgM because there is not the risk of false negativity caused by concurrence of IgG. A combination of ELISA/IgG and ELISA/IgM gives good results as a statistical group: the distribution of results revealed agglomerations of sera corresponding to the assumed age of the infection derived from the generally accepted pattern of antibody formation. The applicability of the combination of these two reactions alone for evaluation of individual sera is a promising procedure but awaits further confirmation. Long-term investigations revealed within two years after infection a marked decline of CFT antibodies in the majority of cases but it was not sufficiently clear in ELISA/IgG. Despite the technical advantages of ELISA reactions, elimination af the CFT reaction is not foreseen in the near future. As the minimal combination of methods which provides adequate information we may consider at the present time CFT for assessment of total antibodies and ELISA/IgM for more marked differentiation of the acute stage. Evaluation of the lowest CFR titres considered hitherto as "practically negative" must be obviously revised in subjects with immunosuppression and organ donors for transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clozapine-induced cholestatic jaundice: a case report

We report on a patient who became jaundiced during treatment with clozapine (Leponex). Histologically, cholestatic hepatitis with single-cell necroses of hepatocytes and infiltration of the portal zones with eosinophilic granulocytes were found. The patient recovered after discontinuation of clozapine, and liver function tests returned to normal within 4 weeks. This adverse effect of clozapine suggests that this "atypical" tricyclic neuroleptic resembles the phenothiazines both with regard to therapeutic spectrum and side effects.     

Auditory evoked potentials to tones and syllables in adults: evidence of specific influence on N250 wave

Brain-derived neurotrophic factor (BDNF) is involved in the differentiation and the survival of neurons. It has also been shown to be associated with the regrowth of neurons of damaged spinal cord and the modulation of ionic currents by acting on sodium channels and NMDA receptors through tyrosine kinase B (TrkB) receptors. We investigated the effects of BDNF on rhythm generation induced by disinhibition in dissociated cultures from embryonic rat spinal cord (E14), with extracellular multisite recordings (MultiElectrode Arrays, MEAs) or intracellular patch-clamp recordings. Exogenous BDNF had only minor effects on the bursting by increasing the activity during the burst. This increase of activity is suggested to be mediated by a potentiation of the postsynaptic NMDA receptors because it has been found that BDNF potentiates the NMDA-evoked depolarization in cultures incubated with BDNF for 10 min. Possible direct effects of BDNF on sodium channels were also investigated by local application of BDNF to the soma of patched neurons but no depolarization was observed. Long-term application of BDNF strongly decreased the activity during the burst and also the number of active electrodes, possibly due to a decrease in network density.