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  • 1
    Electronic Resource
    Electronic Resource
    4-4-20 Anti-Fluorescyl IgG Fab' Recognition of Membrane Bound Hapten: Direct Evidence for the Role of Protein and Interfacial Structure (1995)
    s.l. : American Chemical Society
    Biochemistry 34 (1995), S. 11467-11478 
    Details
    ISSN: 1520-4995
    Source: ACS Legacy Archives
    Topics: Biology , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/bi00036a020
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  • 2
    Electronic Resource
    Electronic Resource
    Apoptosis in marine sponges: a biomarker for environmental stress (cadmium and bacteria) (1998)
    Springer
    Marine biology 131 (1998), S. 411-421 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The marine demosponge Suberites domuncula is abundantly present on muddy sand bottoms, both in the open sea and in harbors. In the present study it is shown that exposure of S. domuncula to cadmium (CdCl2) in concentrations ranging from 0.01 to 5.0 g ml−1 for up to 5 d results in apoptotic fragmentation of DNA. Kinetics experiments revealed that after 24 h a significant increase of DNA fragmentation already occurred. Besides cadmium a second stimulus was identified to also cause apoptosis in this species, namely exposure to heat-treated Escherichia coli. In order to support the finding that both cadmium and E. coli induce apoptosis in the sponge, expression of the apoptotic gene MA-3 was studied. The cDNA, SDMA3, was isolated and found to be 2247 nucleotides long. The deduced amino acid sequence (Mr 50 765) shares high similarity with the corresponding mouse molecule. Like the mouse gene, the sponge MA-3 gene undergoes increased expression in response to apoptotic stimuli. While the specimens remained alive after treatment with cadmium, the sponges treated with E. coli died after approximately 12 d. The E. coli-treated animals started to form gemmules 10 to 12 d after addition of the bacteria. Hence, the process of apoptosis in sponges is triggered by two different pathways, one which is initiated by exogenous factors, e.g. heavy metals, and a second one, caused by endogenous factors, which leads to gemmule formation and a shift of the presumably immortal cells to mortal cells. The latter assumption is supported by the finding that during the process of bacteria-induced apoptosis, which results in the death of the specimens, the activity of the telomerase drops. It is concluded that the cells which appear to be immortal and telomerase-positive undergo apoptosis during the process of gemmule formation. In consequence cells not involved in the production of gemmules become mortal. Based on these data, it is proposed that apoptosis is a suitable biomarker in the bioindicator organism S. domuncula to monitor unfavorable environmental conditions, at least in this animal phylum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002270050334
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  • 3
    Electronic Resource
    Electronic Resource
    16S rRNA sequences as diagnostic tools to elucidate potential symbiotic relationships between bacteria and the marine sponge Halichondria panicea: reply to Stackebrandt and Pukall (Mar Biol 133: 159–161) (1999)
    Springer
    Marine biology 134 (1999), S. 213-215 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002270050539
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  • 4
    Electronic Resource
    Electronic Resource
    17β-Estradiol-dependent regulation of chaperone expression and telomerase activity in the marine sponge Geodia cydonium (1999)
    Springer
    Marine biology 133 (1999), S. 1-10 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract It is known that species belonging to the lowest metazoan phylum, the Porifera (sponges), do not develop tumors. Sponge cells share with tumor cells of higher animals at least one characteristic; they contain high levels of telomerase activity, suggesting that they possess a high proliferation capacity. This assumption, however, has not been substantiated experimentally. In addition, sponges show a specific bauplan, leading us to postulate that they undergo apoptosis to replace a given set of cells at a given time. In the present study, 17β-estradiol (βE2) was used as a defined agent to assess its effect on both the telomerase activity and the process of apoptosis in the marine sponge Geodia cydonium (Jameson). It was found that βE2 (100 to 500 ng ml−1) caused increased expression (i) of the heat-shock protein HSP70 (Mr=70 000), a cytoplasmic chaperone; and (ii) of the nuclear chaperone thioredoxin (TRX), a protein involved in the control of cancer cell growth. For this purpose the gene of G. cydonium encoding TRX was cloned, and the cDNA was applied for the determination of the expression. Verapamil, an inhibitor of both the mammalian multidrug resistance pump and the invertebrate multixenobiotic resistance pump, was used in co-incubation experiments with βE2 to increase the uptake of βE2. The experiments revealed that verapamil augmented the βE2 effect on the expression of the two chaperones, HSP70 and TRX. In addition, the tissue of G. cydonium underwent apoptosis, and the cells lost their telomerase activity. In parallel with the induction of the apoptotic process, the number of DNA strand breaks increased. It is concluded that βE2 displays its effect via the production of reactive oxygen species (ROS). At physiological concentrations ROS cause the expression of HSP70 and TRX, while at higher ROS levels, generated during the co-incubation period of βE2 with verapamil, the cells undergo apoptosis and lose telomerase activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002270050436
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  • 5
    Electronic Resource
    Electronic Resource
    Evidence for a symbiosis between bacteria of the genus Rhodobacter and the marine sponge Halichondria panicea : harbor also for putatively toxic bacteria? (1998)
    Springer
    Marine biology 130 (1998), S. 529-536 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Halichondria panicea (Pallas) is a marine sponge, abundantly occurring in the Adriatic Sea, North Sea, and Baltic Sea. It was the aim of the present study to investigate if this sponge species harbors bacteria. Cross sections through H. panicea were taken and inspected by electron microscopy. The micrographs showed that this sponge species is colonized by bacteria in its mesohyl compartment. To identify the bacteria, polymerase chain reaction (PCR) analysis of the 16S rRNA gene segment, typical for bacteria, was performed. DNA was isolated from sponge material that had been collected near Rovinj (Adriatic Sea), Helgoland (North Sea), and Kiel (Baltic Sea) and was amplified with bacterial primers by PCR. The data gathered indicate that in all samples bacteria belonging to the genus Rhodobacter (Proteobacteria, subdivision α) are dominant, suggesting that these bacteria live in symbiotic relationship with the sponge. In addition, the results show that the different samples taken contain further bacterial species, some of them belonging to the same genus even though found in sponges from different locations. The possibility of the presence of toxic bacteria was supported by the finding that organic extracts prepared from sponge samples displayed toxicity, when analyzed in vitro using leukemia cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002270050273
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  • 6
    Electronic Resource
    Electronic Resource
    The multixenobiotic resistance mechanism in the marine sponge Suberites domuncula: its potential applicability for the evaluation of environmental pollution by toxic compounds (1996)
    Springer
    Marine biology 125 (1996), S. 165-170 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Experiments were carried out with the marine sponge Suberites domuncula to determine whether sponges may express-like mammalian tumor cells-a multidrug-like transporter system. The results demonstrate that sponge cells possess such a protective system termed multixenobiotic resistance (MXR) pump or P-glycoprotein-like pump. The protein was identified by antisera for the mammalian P170 multidrug resistance protein as a 130 kDa molecule. Binding studies were performed with 3H-vincristine (3H-VCR) and membrane vesicles; this process is ATP-dependent and inhibited by verapamil, which is known to reverse the multidrug-resistance phenotype in mammalian systems. Accumulation experiments were performed to demonstrate that the uptake of 3H-VCR is time-dependent, and increases at elevated extracellular levels of 3H-VCR. Application of the dyeing technique with calcein-AM, a suitable functional assay for multidrug transporter systems in mammal cells, also revealed the existence of the MXR pump in S. domuncula plasma membranes. These data demonstrate that S. domuncula is provided with a multidrug-like transporter, the MXR pump, which might function as a protection system for sponges in polluted environments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00350770
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  • 7
    Electronic Resource
    Electronic Resource
    Molecular cloning and primary structure of a Rhesus (Rh)-like protein from the marine sponge Geodia cydonium (1997)
    Springer
    Immunogenetics 46 (1997), S. 493-498 
    Details
    ISSN: 1432-1211
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  In humans, the 30 000 M r Rhesus (Rh) polypeptide D (RhD) is a dominant antigen (Ag) of the Rh blood group system. To date, an Rh-like protein has been found in chimpanzees, gorillas, gibbons, and rhesus monkeys. Related to the 30 000 M r Rh Ag protein are two polypeptides of 50 000 M r , the human 50 000 M r Rh Ag and the RhD-like protein from Caenorhabditis elegans. The function of all these proteins is not sufficiently known. Here we characterize a cDNA clone (GCRH) encoding a putative 57 000 M r polypeptide from the marine sponge Geodia cydonium, which shares sequence similarity both to the RhD Ag and the Rh50 glycoprotein. The sponge Rh-like protein comprises 523 aa residues; hydropathy analysis hints at the presence of ten transmembrane domains. An N-terminal hydrophobic cleavage signal sequence is missing, suggesting that the first membrane-spanning domain of the sponge Rh-like protein acts as a signal-anchor sequence. The sponge Rh-like protein, like the human Rh50, lacks the CLP motif which is characteristic of the 30 000 M r RhD. In addition, the hydropathy profile of the sponge Rh-like protein is of a similar size and shape as that of human Rh50. This data indicates that the RhD and its structurally related Rh50 glycoprotein, which are highly immunogenic in humans, share a common ancestral molecule with the G. cydonium Rh-like protein.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050310
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  • 8
    Electronic Resource
    Electronic Resource
    A new side effect of inhaled nitric oxide in neonates and infants with pulmonary hypertension: functional impairment of the neutrophil respiratory burst (1996)
    Springer
    Intensive care medicine 22 (1996), S. 252-258 
    Details
    ISSN: 1432-1238
    Keywords: Key words Inhaled nitric oxide ; Pulmonary hypertension ; Respiratory burst of neutrophils
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract   Introduction: Inhaled nitric oxide (NO) may be beneficial in the treatment of pulmonary hypertension, both of the newborn and in the adult respiratory distress syndrome. Up to now, serious systemic side effects have not been reported. Objective: The effect of inhaled NO on superoxide anion production by neutrophils. Design: Prospective study of a consecutive series of 15 neonates and infants. Setting: Neonatal and paediatric ICUs with a total of 17 beds (university hospital). Measurements and results: Superoxide anion production was determined by a flow cytometric method using dihydrorhodamine 123 (DHR) as an oxidative probe after the priming of neutrophils with N-formyl-methionyl-leucyl-phenylalanine (fMLP) or with Escherichia coli. The generated fluorescence was expressed as relative fluorescence intensity (RFI). Inhalation of NO for more than 24 h reduced the superoxide anion production by neutrophils stimulated with E. coli to below baseline values before NO inhalation (mRFI=158±25 vs 222±24; P=0.03). This decrease was more pronounced after more than 72 h (mRFI=133±17). At this time, superoxide anion production by fMLP-stimulated neutrophils was also decreased (mRFI=40±3, vs 57±5; P=0.03). The reduced capacity of superoxide production persisted throughout therapy with NO and lasted up to more than 4 days after the end of NO inhalation. Conclusion: The results suggest that inhalation of NO in patients with pulmonary hypertension causes reduced superoxide anion production by neutrophils stimulated with E. coli or with fMLP. To determine the clinical importance of this systemic side effect with respect to bacterial infections, a randomized controlled study is necessary.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01712246
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  • 9
    Electronic Resource
    Electronic Resource
    A tunicate (Botryllus schlosseri) cDNA reveals similarity to vertebrate antigen receptors (1996)
    Springer
    Immunogenetics 45 (1996), S. 69-72 
    Details
    ISSN: 1432-1211
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050169
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  • 10
    Electronic Resource
    Electronic Resource
    Inhaled nitric oxide for avoidance of extracorporeal membrane oxygenation in the treatment of severe persistent pulmonary hypertension of the newborn (1996)
    Springer
    Intensive care medicine 22 (1996), S. 71-76 
    Details
    ISSN: 1432-1238
    Keywords: Nitric oxide ; Persistent pulmonary hypertension ; Extracorporeal membrane oxygenation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Inhaled nitric oxide (NO) is thought to provide a noninvasive therapeutic alternative to extracorporeal membrane oxygenation (ECMO) in the treatment of persistent pulmonary hypertension of the newborn (PPHN). Objective Since January 1993, we have studied inhalation of NO in PPHN patients meeting the ECMO criteria of our institution. We focused on the questions of whether or not the need for ECMO could be obviated and whether differences could be found between NO responders and nonresponders. Design NO gas was delivered via conventional IPPV ventilation in incrementally increasing concentrations from 20 to 80 ppm. Patients NO therapy was attempted in ten ECMO candidates with clinical and echocardiographical evidence of PPHN (mean OI 51.9, SD 10.4). Results At various NO levels (30–60 ppm), five patients showed a significant increase in meanPaO2 (range 32.9–85.9 mmHg). Improvement was transient in three patients (6–10 h) and prolonged in two others (54–80 h); in the latter cases, ECMO was avoided. Five patients did not respond at all to treatment. Responders and nonresponders differed in their mean respiratory tidal volume (8.9 vs 4.18 ml/kg,P〈0.05). Conclusions In our study, inhalation of NO obviated the necessity of ECMO therapy in only two out of ten PPHN patients. Thus, we would discourage any overoptimistic expectations about the effectiveness of NO therapy in PPHN until larger clinical trials have been performed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01728335
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