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P Roch

Publications and source records attributed to P Roch.

At least 37 records · Page 2Linked to original sources
PubMed1997

Immuno-Modulator Effects of Carbaryl and 2,4 D in theEarthworm Eisenia fetida andrei

Carbaryl and 2,4 dichlorophenoxy acetic acid (2,4 D)exerted differential effects on the earthworm E. f. andrei functionsrelated to immuno defense. As determined by contact test assay, carbarylactivity is characterized by a low LC50 value of 3.4 &mgr;g/cm2,compared to 18 &mgr;g/cm2 for 2,4 D. Incubating earthworms withdoses of carbaryl as low as 0.1 &mgr;g/cm2 resulted in theinhibition of the lysozyme activity detected in the cytosol (CL). A stronginhibition of phagocytosis was also obtained but with 1.5&mgr;g/cm2. On the other hand, low doses of carbaryl significantlystimulated cytolysis (0.1 &mgr;g/cm2), serine protease activity (0.1&mgr;g/cm2) in the coelomic fluid (CF) and serine protease activityin the CL (0.05 &mgr;g/cm2). Concerning 2,4 D, both cytolysis in theCF and serine protease activity in the CL were stimulated by respectively 3.5&mgr;g/cm2 and 18 &mgr;g/cm2. Phagocytosis was inhibitedonly with 18 &mgr;g/cm2. Lysozyme and serine protease inhibitoractivities were not affected. The immuno toxicological assays we developed inearthworms, allow to distinguish between chemicals with differentimmuno-modulatory properties. Moreover, earthworms appear to be aparticularly well adapted sentinel organism for the evaluation of soilcontamination.

Journal Article↗
PubMed1996

A member of the arthropod defensin family from edible Mediterranean mussels (Mytilus galloprovincialis)

Plasma from the mussel Mytilus galloprovincialis previously immunized by injecting them with bacteria contains several bactericidal proteins. One protein, MGD-1, was purified by reverse-phase HPLC of supernatant from acidified cell-free hemolymph. Its biological activity is directed against both gram-positive and gram-negative bacteria but it is not cytotoxic towards human erythrocytes nor protozoa. As determined by mass spectrometry, the molecular mass of MGD-1 is 4418 Da. Primary-structure analysis revealed 38 amino acids including 8 cysteines and a modified amino acid residue in position 28. Computer searches unambiguously recognized the signature of an arthropod defensin, but the presence of two extra cysteines and of one modified amino acid suggest that it is a previously unknown member of that family.

Animals↗
PubMed1996

Antibacterial activity in the coelomocytes of the sea urchin Paracentrotus lividus.

Naturally present antibacterial activity directed against Vibrio alginolyticus was demonstrated in coelomocytes lysate (CL) and cell-free coelomic fluid (CF) of the marine echinoderm Paracentrotus lividus. Kinetic analysis revealed that 5 min of contact was enough to induce significant bactericidal effect. Maximum activity required 30 min of contact. Nonsensitive to the effect of trypsin, the activity was almost completely suppressed by incubation with subtilisin. Purified from CL by three successive steps of chromatography (gel filtration, anion exchange, reverse phase), active antibacterial protein appeared as a single polypeptide chain of approximate molecular weight of 60 kDa.

Animals↗
PubMed1996

[Reactive oxygen species and defense mechanisms in marine bivalves].

The main results published on the production of reactive oxygen intermediates by hemocytes and digestive glands of marine bivalves such as mussels, oysters or clams have been reviewed and discussed. Mussel and oyster hemocytes respond to appropriate stimuli with a burst of respiratory activity and the generation of reactive oxygen intermediates in a manner resembling the respiratory burst of mammalian phagocytes. However, interspecies differences in hemocytes-mediated antimicrobial defense mechanisms occur since clam hemocytes do not show any increase of reactive oxygen intermediate production upon similar stimulations. Hepatopancreatic gland of bivalves, as mammalian and fish liver produce reactive oxygen species during the one-electron reduction of xenobiotics, and mechanistic differences appear between bivalves and mammals. Thus, it appears that, in spite of some interspecies differences, the generation of cytotoxic reactive oxygen species is a general protective mechanism of most, if not all, animal species.

Animals↗
PubMed1995

PCBs increase molecular-related activities (lysozyme, antibacterial, hemolysis, proteases) but inhibit macrophage-related functions (phagocytosis, wound healing) in earthworms.

Both humoral and cellular immunodefense responses of the earthworms, Eisenia fetida andrei, Eisenia hortensis, and Lumbricus terrestris, have been compared after exposure to the PCB Aroclor 1254. Responses mediated by free factors, detected by in vitro assays for lysozyme, hemolysis, and proteases, were increased in both Eisenia. Antibacterial activity directed against pathogenic bacteria was increased in E.f. andrei. The resistance of L. terrestris against non-pathogenic bacteria was decreased, confirming that the bacteria were treated by different systems according to their pathogenicity. Nonspecific cellular functions, including phagocytosis and those related to wound healing, decreased dramatically in all earthworms.

Aeromonas hydrophila↗
PubMed1993

Serological evidence and amino acid sequence of ubiquitin-like protein isolated from coelomic fluid and cells of the earthworm Eisenia fetida andrei.

1. A small protein of M(r) 10 kDa has been isolated by reverse-phase chromatography of the basic proteins contained in the coelomic fluid and cell lysate of the earthworm Eisenia fetida andrei. 2. The protein crossreacted in dot-blot with an anti-bovine ubiquitin antiserum. 3. Its N-terminal primary structure was determined by automatic Edman degradation on 26 consecutive amino acids and showed 69% (based on the 26 amino acids) or 82% (based on the first 19 consecutive amino acids) identity with many ubiquitins and similar charge and hydrophobicity profiles and secondary structure conformation.

Amino Acid Sequence↗
PubMed1993

Erythrocyte membrane structural features that are critical for the lytic reaction of Spirograhis spallanzani coelomic fluid hemolysin.

1. Hemolytic activity of Spirographis spallanzani coelomic fluid depends on factor(s) strongly influenced by calcium but not by sulfhydril or disulfide reagents. 2. The lytic reaction was suppressed by low zinc ion concentrations but it was not influenced by the presence of proteinase inhibitors. 3. These data indicate that S. spallanzani hemolysin is a non-enzymatic, calcium-dependent, zinc-inhibitable factor that occurs naturally in the coelomic fluid. 4. In the absence of calcium, enzymatic desialization converted sheep erythrocytes into susceptible targets, suggesting the involvement of erythrocyte surface sialic acid. 5. However, the inhibitory effect of the sugar on anti-rabbit lysis was partially removed by addition of calcium. 6. Attempts to characterize membrane components that are critical for hemolysis were performed by inhibition experiments. 7. We found that saccharides, glycoproteins, mucosubstances as well as rabbit erythrocyte soluble tryptic fragments were ineffective in inhibiting hemolysis. 8. Sonicated dispersion of phosphatidyl choline, phosphatidyl glycerol, phosphatidyl ethanol, sphingomyelin and cholesterol did not influence the hemolytic reaction. 9. Rabbit erythrocyte extracted from membrane lipids (chloroform phase) did not modify the lytic activity against rabbit red blood cells. 10. Conversely, the methanol phase consistently reduced the lytic capacity of the fluid. 11. The heat-stable, trypsin-resistant inhibitory factor was most probably a small molecule, since dialysis removed the inhibitory effect.

Animals↗
PubMed1992

The capacities of earthworms to heal wounds and to destroy allografts are modified by polychlorinated biphenyls (PCB).

Earthworms (Lumbricus terrestris) were maintained at 15 degrees C and exposed on filter paper to 10 micrograms/cm2 of the polychlorinated biphenyl (PCB) Aroclor 1254 for 5 days prior to surgical treatments which consisted of wounds, autografts, and allografts. At 1 day after surgery, we observed a higher percentage of healing defects and a significantly greater number of early signs of allograft rejection in exposed worms. Observations for 25 days post-transplantation revealed no response to autografts, but an acceleration of the allograft rejection process in exposed earthworms. We postulate that Aroclor modified host coelomocytes and/or their interactions associated with antigen recognition and inflammation.

Animals↗
PubMed1991

Antibacterial activity of Eisenia fetida andrei coelomic fluid: III--Relationship within the polymorphic hemolysins.

The antibacterial activity exhibited by 10 different hemolytic, genetic families was established by measuring the inhibition of spontaneous in vitro growth by cell-free coelomic fluid toward 2 bacteria which are pathogenic for the earthworm: Bacillus megaterium (Gram +) and Aeromonas hydrophila (Gram -). Only two families (B and K) displayed potent inhibitory activities. This finding is consistent with the fact that the B family occurs most frequently in both natural as well as in industrial breedings. Nevertheless, evidence of a poor antibacterial defense in some frequent families suggests the existence of alternative antibacterial mechanisms.

Animals↗
PubMed1991

Cellular but not humoral antibacterial activity of earthworms is inhibited by Aroclor 1254.

Earthworms, Eisenia fetida andrei and Lumbricus terrestris, exposed to Aroclor 1254, followed by infestation with Aeromonas hydrophila, elicited two types of responses. First, in E. fetida, there was no change in the LD50 nor in the in vitro antibacterial growth capacity of cell-free coelomic fluid. Thus, Aroclor exerts no influence on antibacterial proteins nor on the chloragogue cells responsible for their release. Second, in L. terrestris, both a high LD50 value and no antibacterial activity indicate that A. hydrophila was not pathogenic. The 10(4) times higher sensitivity of exposed L. terrestris suggests that Aroclor inhibits leukocyte activity since E. fetida eliminates nonpathogenic bacteria by a cellular mechanism.

Aeromonas hydrophila↗
PubMed1991

Characterization of Campylobacter jejuni strains occurring in the USSR and the Czech Republic.

In 1986-1989 the microbiological laboratory in Prague obtained 100 Campylobacter jejuni strains while its counterpart in Moscow gained 120 such strains. The strains were primarily isolated from humans with diarrheal disease, from domestic and wild animals and from the environment. Most C. jejuni strains were successfully specified and classified using a Czechoslovak serotyping scheme proposed by Kahlich. Serotypes 1, 2, 7, 15, 22 and 24 occurred most frequently in the Czech Republic whereas in the Soviet Union the most common serotypes were 7, 16, 5, 2, 1. The proportion of strains which could not be identified in the serotyping scheme was about 10% in the USSR and 20% in the Czech Republic. Our findings suggest differences between the USSR and the Czech Republic in the prevalence and incidence particular serotypes of C. jejuni strains.

Animals↗
PubMed1989

Interactions between earthworm hemolysins and sheep red blood cell membranes.

The hemolytic activity exhibited by the coelomic fluid of the Annelid Eisenia fetida andrei is mediated by two lipoproteins of mass 40 and 45 kDa, each of them capable of hemolysis. Such an activity is not inhibited by zymosan, inulin or lipopolysaccharide (LPS), nor by hydrazine or methylamine, suggesting that earthworm hemolysins are not related to C3 or C3b complement components. Among the membrane lipids tested (phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, sphingomyelin and cholesterol) only sphingomyelin inhibited hemolysis. The analysis of E.f. andrei proteins bound to sphingomyelin microvesicles, as well as to sheep red blood cell (SRBC) membranes, revealed a polymerization of E.f. andrei 40 kDa and/or 45 kDa hemolysins. Consequently, sphingomyelin appears a likely candidate for hemolytic complex receptor. Electron microscopy observations suggested that the polymerization causes an open channel through the lipid bilayer. As demonstrated using metal ions, heparin, chondroitin sulfate, poly(L-lysine) and protamine chloride, the mode of action of earthworm hemolytic complex is not analogous to that of C9 or perforine.

Animals↗
PubMed1986

Second-set allograft responses in the earthworm Lumbricus terrestris. Kinetics and characteristics.

Second-set Lumbricus terrestris allografts from the same donor to the same recipient undergo accelerated rejection if transplanted less than 10 days after first-set allografts. In contrast, second-set allografts, transplanted at longer intervals (20-90 days) show no accelerated rejection. Accelerated rejection of allotransplants under these kinetic conditions agrees with earlier intrafamilial xenotransplant results obtained in earthworms affirming an essential experimental variable: the time of second-set transplantation. Accelerated rejection, weak specificity, and short-term "memory" are three characteristics of the earthworm's allogeneic cellular defense/immune system. These reactions probably result from intense responses (although of short duration) of coelomocytes activated by first transplants that are still present at the time of second-set grafting but absent or inactive at later periods.

Animals↗
PubMed1985

Protein analysis of earthworm coelomic fluid. III. Isolation and characterization of several bacteriostatic molecules from Eisenia fetida andrei.

A bacteriostatic activity in Eisenia fetida andrei cell free coelomic fluid is described. This activity is detected by growth inhibition of a bacteria Bacillus megaterium. Gel filtration analysis revealed eleven coelomic fluid protein fractions designated A, B,..J. Antibacterial activity was mainly found within fractions B and C. Chromatofocusing resolved fractions B-C into five different peaks named alpha BC, beta BC,... epsilon BC. Antibacterial activity appeared mediated by three different proteins characterized by their molecular weights (20,000, 40,000 and 45,000) and their isoelectric points (4.9, 5.75 and 6.0). These bacteriostatic proteins possess either hemolysis or hemagglutination activities. The polymorphic aspect of this humoral antibacterial defense is discussed.

Animals↗
PubMed1984

Earthworm leukocyte interactions during early stages of graft rejection.

The earliest phase of graft rejection in earthworms, the recognition of foreign tissue antigens, has been subjected to analysis by confronting host leukocytes with foreign erythrocytes. Only rabbit and rat erythrocytes significantly prevented healing of allografts when grafts were transplanted and erythrocytes injected simultaneously. In contrast, autografts and allografts transplanted on worms injected 1 or 2 days before grafting were never affected. Since earthworms readily produce higher titers of erythrocyte agglutinins at 24 h postinjection than at later times, we propose a hypothetical scheme of earthworm leukocyte interactions that may occur during the early phases of graft healing and of agglutinin synthesis.

Animals↗
PubMed1983

Serological evidences for a membrane structure related to human beta 2-microglobulin expressed by certain earthworm leukocytes.

Indirect immunofluorescence performed with 2 polyclonal and 4 monoclonal antibodies directed against human beta 2-microglobulin (beta 2m) revealed the presence of a beta 2m-like determinant on the membrane of a subpopulation of earthworm leukocytes classified as weakly adherent acidophils. Two out of the 4 monoclonal antibodies were found to bind to 15% of the earthworm leukocytes. Similar results were obtained with antibodies specific for beta 2m and isolated by affinity chromatography from either polyclonal antiserum or anti-beta 2m hybridoma supernatant. Additional binding inhibition and competition experiments strengthened the results and suggested that the homology between the structure present on earthworm leukocytes and human beta 2m may be restricted to only one major determinant. The existence of a beta 2m-like molecule in earthworms may provide important clues for understanding protein evolution and basic immune mechanisms.

Animals↗