COX inhibitors modulate bFGF-induced cell survival in MCF-7 breast cancer cells

Basic fibroblast growth factor (bFGF) serves as a modulator of survival in breast cancer cells. The mechanisms by which bFGF transduces the anti-apoptotic signal and interacts with COX inhibitors were investigated. bFGF reduced apoptosis in MCF-7 breast cancer cells and up-regulated the expression of mitocondrial Bcl-2, whereas COX inhibitors meloxicam (selective COX-2) and aspirin (non-selective), induced apoptosis. bFGF up-regulated survivin protein expression and induced cdc-2 phosphorylation moderately at early (2-6 h), and substantially at late (24 h), time-points. Survivin mRNA expression was up-regulated only at the later time-point. COX inhibitors prevented up-regulation of survivin protein expression at both 2 and 24 h and prevented early modest increases in cdc-2 phosphorylation. Up-regulation of survivin mRNA was not found to be modulated by the COX-2 inhibitor meloxicam. bFGF regulation of survivin expression was found to be ERK1/2 kinase dependent and bFGF-induced phosphorylation of c-raf was prevented by the COX-2 inhibitor. bFGF was, however, unable to induce COX-2 protein expression or modulate COX-2 activity in MCF-7 cells as evidenced by unaltered PGE(2) production. These results indicate that bFGF regulates survivin expression in MCF-7 breast cancer cells by signaling through an ERK1/2 dependent pathway. COX-2 inhibitors can modulate bFGF-induced survivin expression in a COX-2 independent manner.     

Human enhancer of invasion-cluster, a coiled-coil protein required for passage through mitosis

In a cross-species overexpression approach, we used the pseudohyphal transition of Saccharomyces cerevisiae as a model screening system to identify human genes that regulate cell morphology and the cell cycle. Human enhancer of invasion-cluster (HEI-C), encoding a novel evolutionarily conserved coiled-coil protein, was isolated in a screen for human genes that induce agar invasion in S. cerevisiae. In human cells, HEI-C is primarily localized to the spindle during mitosis. Depletion of HEI-C in vivo with short interfering RNAs results in severe mitotic defects. Analysis by immunofluorescence, flow cytometry analysis, and videomicroscopy indicates that HEI-C-depleted cells form metaphase plates with normal timing after G(2)/M transition, although in many cases cells have disorganized mitotic spindles. Subsequently, severe defects occur at the metaphase-anaphase transition, characterized by a significant delay at this stage or, more commonly, cellular disintegration accompanied by the display of classic biochemical markers of apoptosis. These mitotic defects occur in spite of the fact that HEI-C-depleted cells retain functional cell cycle checkpoints, as these cells arrest normally following nocodazole or hydroxyurea treatment. These results place HEI-C as a novel regulator of spindle function and integrity during the metaphase-anaphase transition.     

The avrRxo1 gene from the rice pathogen Xanthomonas oryzae pv. oryzicola confers a nonhost defense reaction on maize with resistance gene Rxo1

Maize lines that contain the single dominant gene Rxo1 exhibit a rapid hypersensitive response (HR) after infiltration with the rice bacterial streak pathogen Xanthomonas oryzae pv. oryzicola, but not with the rice bacterial blight pathogen X. oryzae pv. oryzae. The avirulence effector gene that corresponds to Rxo1, designated avrRxo1, was identified in an X. oryzae pv. oryzicola genomic library. When introduced into X. oryzae pv. oryzae, clones containing avrRxo1 induced an HR on maize with Rxo1, but not on maize without Rxo1. The avrRxo1 gene is 1,266 bp long and shows no significant homology to any database sequences. When expressed in an X. oryzae pv. oryzae hrpC mutant that is deficient in the type III secretion system, avrRxo1 did not elicit the HR, indicating that the avrRxo1-Rxo1 interaction is dependent on type III secretion. Transient expression of avrRxo1 in onion cells after biolistic delivery revealed that the protein product was associated with the plasma membrane. Transient expression in maize lines carrying Rxo1 resulted in cell death, suggesting that AvrRxo1 functions from inside maize cells to elicit Rxo1-dependent pathogen recognition.     

Sensitivity of neuronal nicotinic acetylcholine receptors to the opiate antagonists naltrexone and naloxone: receptor blockade and up-regulation

In HEK293 cells stably expressing alpha4beta2 nAChRs, naltrexone, but not naloxone, blocked alpha4beta2 nAChRs via an open-channel blocking mechanism. In primary hippocampal cultures, naltrexone inhibited alpha7 nAChRs up-regulated by nicotine, and in organotypic hippocampal cultures naltrexone caused a time-dependent up-regulation of functional alpha7 nAChRs that was detected after removal of the drug. These results indicate that naltrexone could be used as a smoking cessation aid.     

Skin Donors Positive for HBV Core Antibodies – to Bank or Not to Bank? An Overview from a Regional Tissue Bank

A prompt transplantation of skin allografts on patients with severe, large body area burns is a preferred treatment, but depends on a suitable supply of tissue donors. Limiting factors include donors' identification, families consent, and following the standards – exclusion due to assessed transmissible diseases. To increase the current rate of skin donations to our regional skin bank, we reviewed the data of all potential organ donors, identified at Soroka University Medical Center from October 1997 to December 2000 and evaluated the causes for exclusion, especially due to HBV serological profile. 114/168 (67.9%) patients did not meet the indicated standards for organ donation, among which 20/114 patients (17.5%) positive for anti-HBc (anti-HBc⁺). 54/168 persons were declared brain dead, with consents obtained from 21 families. To discuss the intriguing approval of skin from potential donors with anti-HBc⁺ serology, the literature was reviewed, specifically – the reported outcomes of organ transplants from anti-HBc⁺ donors, updates of HBV and skin, available tests, and finally a look for a safe commendable algorithm. The results suggested that HBV might be replicating in the skin, but proven communication of HBV has not been reported following grafting skin from anti-HBc⁺ donors. Unlike other procured organs and tissues, grafted banked skin is a temporary cover, storable up to six years, under appropriate conditions. Hence, banking of skin from anti-HBc⁺ donors might be considered for future grafting of patients with identical serological profiles, presumably immune to a subsequent HBV infection, until a further re-evaluation of the standards. This procedure is anticipated to increase the potential of organ and tissue donations, specifically skin.     

Der Zug des Wei?storchs (Ciconia ciconia): eine besondere Zugform auf Grund neuer Ergebnisse

Zusammenfassung Für ein umfassendes Schutzkonzept für den Weißstorch (Ciconia ciconia) im Rahmen der Bonner Konvention entlang der Ostroute von den Brutgebieten über Israel bis in nordostafrikanische Zwischenziele war es erforderlich, den genauen Zugablauf, das Rastverhalten sowie Fragen der Zugenergetik und Zugökologie zu untersuchen. Wir bearbeiteten die Fragen mit Hilfe der Satelliten-Telemetrie (75 Individuen), der Untersuchung von Störchen in Volieren einschließlich der Magnet-Resonanz-(MR-)Tomographie und -Spektroskopie (MRS) (12 Vögel, über 15 Monate) sowie umfangreicher Freilandstudien. Das Hauptergebnis der Untersuchungen ist: Der Weißstorch zeigt — zumindest auf der Ostroute — einen eigenartigen, bisher von keiner anderen Vogelart in dieser Form beschriebenen Zugmodus mit folgenden Charakteristika: 1) sehr zügiges, normalerweise tagtägliches Wandern vom Brutgebiet bis in die nordafrikanischen Zwischenziele, wobei täglich etwa 8–10 Stunden gewandert und 14–16 Stunden gerastet wird. Die rund 4 600 km bis zum 18. Breitengrad werden von Jung- wie Altstörchen im Mittel in 18–19 Tagen bewältigt. 2) Ganz- oder gar mehrtägige Rast wird nur ausnahmsweise eingeschoben und scheint eher durch äußere Umstände erzwungen als im endogenen Zugprogramm vorgegeben zu sein. 3) Körpermasse und Fettdeposition sind während des Wegzugs (und des Heimzugs) niedrig und erreichen Gipfelwerte im Mittwinter, die als Anpassung an unvorhersagbare Bedingungen im Winterquartier gedeutet werden. 4) Zugzeitliche Hyperphagie ist nicht erkennbar, vielmehr nehmen Störche während des Wegzugs Nahrung in Osteuropa wohl v. a. zur Deckung des Unterhaltsbedarfs auf, zum Mittelmeer hin mehr opportunistisch und in Israel so gut wie gar nicht. Dadurch und aus dem Vergleich von Körpermassen in Sachsen-Anhalt und Israel wird wahrscheinlich, dass Störche auf dem Wegzug an Masse verlieren, die dann erst in Afrika wieder aufgefüllt wird. Wir bezeichnen den Zugmodus des überwiegend im Gleitflug wandernden Weißstorchs als MSOM-Typ (von Meist täglich wandernd, Selten ganze Rasttage einlegend, Opportunistisch Nahrung aufnehmend und Maximal Mittelmäßige Fettdepots bildend) und stellen ihm die Typen ILHB (für intermittierend ziehend) sowie NNHB (nonstop wandernd) gegenüber (s. Diskussion). Die Ergebnisse dieser Arbeit, v. a. über Fettdeposition und Brustmuskelzustand, beruhen ganz wesentlich auf der MR-Tomographie und MR-Spektroskopie, die hier in einer Lang-zeit-Pilotstudie an einer wild lebenden Vogelart zum Einsatz kam und sich als sehr nützlich und vielversprechend erwies (s. die nachfolgende Arbeit).

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The migration of the White Stork (Ciconia ciconia): a special case according to new data

Summary To formulate a comprehensive plan for the conservation of the White Stork (Ciconia ciconia) in conformity with the Bonn Convention, along the eastern migration route from the breeding grounds across Israel into the staging areas in northeastern Africa, it was essential to investigate the entire process of migration, including resting behaviour as well as the energetic and ecological aspects. Our approach employed satellite tracking (of 75 individuals), observations of storks in aviaries by methods including magnetic resonance imaging (MRI) and spectroscopy (MRS) (12 birds over 15 months), and extensive field studies. The main result of the investigation is that the White Stork exhibits, at least on the eastern route, a particular mode of migration not previously described in this form for any bird species, with the following characteristics: (i) very rapid travel from the breeding region into the North African staging areas, normally with flight periods every day, lasting about 8–10 hours and separated by 14–16 hours of rest. The ca. 4600-km distance to latitude 18°N is covered in an average of 18–19 days by both young and adult storks. (ii) Rest periods of a whole day or even several days are the exception, and their occurrence seems to be prompted by external circumstances rather than prescribed in the endogenous migration program. (iii) Body mass and fat deposition are low during the outward (and the homeward) journey and peak in midwinter, which is interpreted as an adaptation to unpredictable conditions in the winter quarters. (iv) There is no discernible hyperphagia during migration; instead, on the outward journey the storks evidently feed mainly to meet their immediate needs when in eastern Europe, more opportunistically when approaching the Mediterranean Sea, and practically not at all in Israel. According to this observation and the comparison of body weights in Sachsen-Anhalt and Israel, it is likely that storks lose weight on the outward trip and do not regain it until they reach Africa. We call the migration mode of the White Stork, which travels predominantly in gliding flight, the MSOM type (from mostly travelling every day, seldom inserting whole-day rests, opportunistically feeding and moderate or no fat depots developing), and distinguish it from the types ILHB (for intermittently migrating) and NNHB (migrating non stop) (see Discussion). The results of this study, in particular regarding fat deposition and state of breast musculature, are based substantially on MRI and MRS; these methods, tested here in a pioneering long-term study of a bird species living in the wild, have proved extremely useful and show great promise (see following paper).

     

Co-polymers of Actin and Tropomyosin Account for a Major Fraction of the Human Actin Cytoskeleton

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Structural identities of four glycosylated lipids in the oral bacterium Streptococcus mutans UA159

The cariogenic bacterium Streptococcus mutans is an important dental pathogen that forms biofilms on tooth surfaces, which provide a protective niche for the bacterium where it secretes organic acids leading to the demineralization of tooth enamel. Lipids, especially glycolipids are likely to be key components of these biofilm matrices. The UA159 strain of S. mutans was among the earliest microorganisms to have its genome sequenced. While the lipids of other S. mutans strains have been identified and characterized, lipid analyses of UA159 have been limited to a few studies on its fatty acids. Here we report the structures of the four major glycolipids from stationary-phase S. mutans UA159 cells grown in standing cultures. These were shown to be monoglucosyldiacylglycerol (MGDAG), diglucosyldiacylglycerol (DGDAG), diglucosylmonoacylglycerol (DGMAG) and, glycerophosphoryldiglucosyldiacylglycerol (GPDGDAG). The structures were determined by high performance thin-layer chromatography, mass spectrometry and nuclear magnetic resonance spectroscopy. The glycolipids were identified by accurate, high resolution, and tandem mass spectrometry. The identities of the sugar units in the glycolipids were determined by a novel and highly efficient NMR method. All sugars were shown to have α-glycosidic linkages and DGMAG was shown to be acylated in the sn-1 position by NMR. This is the first observation of unsubstituted DGMAG in any organism and the first mass spectrometry data for GPDGDAG.     

Interacting biocontrol programmes: invasive cane toads reduce rates of breakdown of cowpats by dung beetles

Ecological interactions among invasive species can affect not only the success of the invaders, but also their impact on ecosystems in the invaded range. In Australia, both dung beetles (subfamily Scarabaeinae) and cane toads (Rhinella marina) were introduced for biocontrol: the beetles to break down bovine faeces piles (cowpats) that otherwise accumulate and reduce pasture productivity, and the cane toad to consume scarab beetles that eat sugarcane and thus reduce sugar production. The dung beetles have been a success, whereas the toads have been a failure. Our experimental studies show that as well as impacting native fauna directly, cane toads reduce the rate of cowpat breakdown by consuming dung beetles. In the laboratory, dehydrated toads actively sought out cowpats based on scent cues, and in field enclosures, the presence of a cane toad significantly reduced rates of cowpat decomposition. Although toads have benefited from agricultural activities, their spread across Australia likely has reduced the effectiveness of one of the most successful biocontrol programmes ever conducted in that continent.     

The Loudness Dependence of Auditory Evoked Potentials (LDAEP) as an Indicator of Serotonergic Dysfunction in Patients with Predominant Schizophrenic Negative Symptoms

Besides the influence of dopaminergic neurotransmission on negative symptoms in schizophrenia, there is evidence that alterations of serotonin (5-HT) system functioning also play a crucial role in the pathophysiology of these disabling symptoms. From post mortem and genetic studies on patients with negative symptoms a 5-HT dysfunction is documented. In addition atypical neuroleptics and some antidepressants improve negative symptoms via serotonergic action. So far no research has been done to directly clarify the association between the serotonergic functioning and the extent of negative symptoms. Therefore, we examined the status of brain 5-HT level in negative symptoms in schizophrenia by means of the loudness dependence of auditory evoked potentials (LDAEP). The LDAEP provides a well established and non-invasive in vivo marker of the central 5-HT activity. We investigated 13 patients with schizophrenia with predominant negative symptoms treated with atypical neuroleptics and 13 healthy age and gender matched controls with a 32-channel EEG. The LDAEP of the N1/P2 component was evaluated by dipole source analysis and single electrode estimation at Cz. Psychopathological parameters, nicotine use and medication were assessed to control for additional influencing factors. Schizophrenic patients showed significantly higher LDAEP in both hemispheres than controls. Furthermore, the LDAEP in the right hemisphere in patients was related to higher scores in scales assessing negative symptoms. A relationship with positive symptoms was not found. These data might suggest a diminished central serotonergic neurotransmission in patients with predominant negative symptoms.