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At least 811 records · Page 45Linked to original sources
PubMed1975

[Morphological and functional variations of the muscles of invertebrates].

The problem of muscle evolution among Invertebrates has been considered, mainly in obliquely strated fibers of Annelida and in trasversally striated fibers of Insecta. In both groups the morphological variations run parallel to the functional requirements; similar modulations, in fact, have been observed in fast and slow acting muscle fibers independently from the basic pattern of Insecta and Annelida fibers. Fast acting muscles are characterized by a lesser diameter of myosin filaments and a low thin-to-thick filament ratio. On the contrary, the slow acting muscles show a greater diameter of the myosin filaments and a higher thin-to-thick filament ratio. These observations agree with the hypothesis of a common origin of almost all muscular systems.

Animals↗
PubMed2003

Toxicokinetics of sediment-sorbed benzo[a]pyrene and hexachlorobiphenyl using the freshwater invertebrates Hyalella azteca, Chironomus tentans, and Lumbriculus variegatus.

This study investigated the effect of long-term sediment aging on the toxicokinetics of benzo[a]pyrene (BaP) and hexachlorobiphenyl (HCBP) using three freshwater benthic invertebrates. Hyalella azteca, Chironomus tentans, and Lumbriculus variegatus were exposed to BaP- and HCBP-spiked sediments that were aged for 7 d or 1.5 years. The toxicokinetics of the two compounds were determined for each test organism using a two-compartment model. The modeling of BaP was more complex because biotransformation was included within the model. The results of this study showed that the HCBP uptake clearance rates (k(s)) for each species were generally an order of magnitude greater than those determined for BaP and this difference was most likely due to preferential and rapid binding of BaP to sediment particles. Overall, the bioavailability of HCBP in spiked sediments tended to decrease with duration of aging, based on k(s) values and bioaccumulation factors (BAFs). However, the decreases in bioavailability appear to be species specific. Benzo[a]pyrene did not decline in bioavailability for the species tested because it may resist movement into the micropores of the sediment due to its large size. In addition to the bioassays, this article outlines a method for toxicokinetic modeling of biotransformed compounds and methods for statistical comparisons of kinetic parameters (i.e., k(s), k(d)...) and BAF values.

Adsorption↗
PubMed1976

[Metacercaria in the invertebrates of the Madras coast].

In planktonic and benthic invertebrates of the Madras coast, Bay of Bengal, six Metacercariae have been reported. Four species are from planktonic intermediate hosts. They were found in Ctenophora, Leptomedusa and the gastropod Janthina. They belong to the Hemiurate, Fellodistomatidae and Lepocreadiidae. Two species are from benthic molluscs and belong to the family Monorchiidae respectively to the subfamily Halipeginae. We can expect that the adults of three species are not described.

Animals↗
PubMed2003

The relative sensitivity of four benthic invertebrates to metals in spiked-sediment exposures and application to contaminated field sediment.

The relative sensitivity of four benthic invertebrates (Hyalella azteca, Chironomus riparius, Hexagenia spp., and Tubifex tubifex) was determined for Cd, Cu, and Ni in water-only and in spiked-sediment exposures. Survival (median lethal concentrations [LC50s] and the concentrations estimated to be lethal to 25% of test organisms [LC25s]), and endpoints for growth and reproduction (mean inhibitory concentrations [IC25s]) were compared. The sensitivities differed depending on the species and metal, although some trends emerged. In water-only exposures, H. azteca is the most sensitive species to cadmium and nickel, with mean LC50s of 0.013 and 3.6 mg/L, respectively; C. riparius is the most sensitive species to copper, with a mean LC50 of 0.043 mg/L. In the spiked-sediment exposures, the order in decreasing sensitivity to copper is Hyalella = Hexagenia < Chironomus < Tubifex for survival and growth/reproduction. For cadmium, the order in decreasing sensitivity is Hyalella = Chironomus < Hexagenia < Tubifex, and for nickel is Hyalella << Hexagenia < Chironomus < Tubifex. Chironomus riparius and Hexagenia spp. survival can be used to distinguish between toxicity caused by different metals. Species test responses in field-collected sediment(Collingwood Harbour, ON, Canada) were examined in an attempt to determine the causative agent of toxicity throughout, using the established species sensitivities. Sediment toxicity was categorized first by comparing species responses to those established for a reference database. Test responses in the field-collected sediment do not support causality by Cu, a suspected toxicant based on comparison of sediment chemistry with sediment quality guidelines.

Animals↗
PubMed2003

[Application of terrestrial invertebrates biomarkers in soil pollution ecology study].

Biomarkers in terrestrial invertebrates play an important role in estimating either exposure or resultant effects of pollutants in soil ecosystem, which has received increasing attention and made significant progress. The present paper has drawn three important biomarkers, i.e., lysosomes, stress protein and mettllothioneins (MTs). The lysosomal membrane stability of coelomocytes was assayed as neutral-red retention time (NRR-time) resulting from toxicant stress. Hsp70 and Hsp60 were commonly used in the stress protein families. The quantification methods of different isofoms of the mettllothioneins could specifically indicate different metal contamination. The rationale, characteristics, and relevant exemplary case of assaying the biomarkers and their promising application to ecotoxicological diagnosing in soil contamination were discussed.

Animals↗
PubMed2004

Reticuline exposure to invertebrate ganglia increases endogenous morphine levels.

OBJECTIVES: Given the presence of morphine, its metabolites and precursors in mammalian and invertebrate tissues, it became important to determine if exposing tissues to an opiate alkaloid precursor, reticuline, would result in increasing endogenous morphine levels. METHOD: Endogenous morphine levels were determined by high pressure liquid chromatography coupled to electrochemical detection and radioimmunoassay following incubation of Mytilus edulis pedal ganglia with reticuline. Nitric oxide (NO) release was determined in real-time via an amperometric probe. Mu opiate receptor affinity for opiate alkaloid precursors was determined by a receptor displacement assay. RESULTS: Morphine is present in the pedal ganglia of Mytilus edulis (1.43 +/- 0.41 ng/mg +/- SEM ganglionic wet weight). Ganglia incubated with 50 ng of reticuline, a morphine precursor in plants, for 1 hour exhibited a statistical increase in their endogenous morphine levels (6.7 +/- 0.7 ng/mg tissue wet weight; P<0.01). This phenomenon is concentration dependent. The increase in ganglionic morphine levels occurs gradually over the 60 min incubation period, beginning 10 minutes post reticuline addition. We show that reticuline (10(-6) M) does not stimulate ganglionic NO release in a manner resembling that of morphine (10(-6) M), which releases NO seconds after its exposure to the ganglia and lasts for 5 minutes. With reticuline, there is a 3 minute delay, which is followed by an extended release period. Furthermore, in binding displacement experiments both reticuline and salutaridine (another morphine precursor) exhibit no binding affinity for the pedal ganglia mu opiate receptor subtype. This finding is further substantiated using the positive control of human monocytes where the mu3 opiate receptor subtype has been cloned. CONCLUSION: Taken together, we surmise that the morphine's precursors are being converted to morphine. The experiments strongly indicate that pedal ganglia can synthesize morphine from reticuline.

Alkaloids↗
PubMed2004

[Locomotor reactions and excitability of neurons during the blockade of dopamine by haloperidol in vertebrate and invertebrate animals].

Two groups of rats with different level of motor activities: high- and low-active animals, were distinguished. The blockade of dopamine receptors by haloperidol led to depression of locomotor activity in both groups of rats; in grape snails, haloperidol caused a decrease of the velocity of locomotor responses. In was found that within 5 minutes of intravenous injection of haloperidol the excitability of spinal centers of rats decreased; but in 30 minutes in started restoring. Chronic application of the preparation depressed the effect of posttetanic potentiation of H-response in gastrocnemius muscle of spinal rats. In command neurons of grape snail, chronic injections of haloperidol causes a significant hyperpolarization shift of membrane potential and an increase of threshold of the generation of action potential. It was shown that the selective pharmacological inhibition of dopaminergic system of the brain led to a decrease of excitability in some determined neurons of the snail and spinal motor centers of rats, as well as inhibited the locomotor responses both in vertebrate and in invertebrate animals.

Action Potentials↗
PubMedDate not supplied

[Effect of aluminum and iron on lipid metabolism in aquatic invertebrates].

Methods of thin-layer, gas-liquid, and liquid chromatography were applied to the study of the effect of various concentrations of aluminum and iron salts on the contents of phospholipids, cholesterol, and fatty acids in the aquatic invertebrate Hydropsyche contubernalis L. (Trichoptera). It was found that the effect of the metals under study on lipid contents in living organisms depended on the composition of the aqueous medium and concentrations of the metals. Aluminum and iron altered the value of the cholesterol-to-phospholipid molar ratio. In the absence of lethal effects, this was indicative of attempts to switch adaptational biochemical mechanisms to stabilize cellular structures.

Aluminum Compounds↗
PubMedDate not supplied

[Taxonomical study of bacteria from genera Alteromonas and Pseudoalteromonas isolated from Black Sea water and invertebrates].

Nineteen (19) strains of bacteria have been isolated from the Black Sea water and invertebrates (mollusks and actinia). Most of them have been identified as Alteromonas macleodii, Pseudoalteromonas citrea and P. haloplanktis on the basis of polyphasic taxonomical analysis. Six strains showed 96-97 % similarity to 16S rRNA sequence of the known species of Pseudoalteromonas and obviously belonged to new species. The studied strains have been characterized by a wide spectrum of phenotypic features (morphology, enzyme activity, spectra of carbon nutrition, antibiotic sensitivity); high sensitivity of P. haloplanktis strains to cephalotin and resistance of A. macleodii strains to furadonin made them different than other studied strains of Alteromonas and Pseudoalteromonas.

Alteromonas↗
PubMed2006

Bacterial symbionts: prospects for the sustainable production of invertebrate-derived pharmaceuticals.

Invertebrate animals, such as sponges, tunicates and bryozoans, are among the most important sources of biomedically relevant natural products. However, as these animals generally contain only low quantities of the compounds, further pharmacological development is in most cases difficult. There is increasing evidence that many metabolites, in particular polyketides and nonribosomally synthesized peptides, are not produced by the animals themselves but by associated bacterial symbionts. This symbiont hypothesis currently attracts considerable interest, since it implicates that animal-independent production systems based on bacterial fermentation processes could be created. This review gives an overview about recent developments in the research on natural product symbiosis. Different techniques will be discussed that have been employed to pinpoint the actual producer. Since bacterial symbionts are highly fastidious and have been generally resistant to cultivation attempts, emphasis will be laid on culture-independent strategies, such as cell separation approaches and the cloning of biosynthetic genes. These strategies have provided insights into possible sources of several natural products, e.g. the bryostatins, pederin, the onnamides, swinholide A and theopalauamide. Finally, potential techniques for the generation of renewable supplies of symbiont-derived drug candidates will be discussed. Cultivation approaches and the heterologous expression of cloned biosynthesis genes from uncultured symbionts could in future provide access to several important marine drug candidates, including bryostatin 1, halichondrin or ET-743.

Animals↗
PubMedDate not supplied

[Some rules of soil invertebrate community organization (by the example of Amur Basin mesofauna)].

Some rules of organization of soil communities in the zone of mixed, Jeddo spruce, and larch taiga as well as forest-steppe in the Amur Basin have been formulated on the basis of the factual data. Abundant resources in the soil layer proved to decrease the competition in favor of neutralism, which allows sister species to occupy the same ecological niche. The stability of soil conditions allows considerable contraction of the realized niche volume, which increases species richness in soil. The biocenotic significance of soil organisms is determined by their biomass, productivity, and functional interchangeability. Ecological redundancy makes the mesofauna community much more resistant to environmental factors. The interaction type can change with environmental conditions. Competition prevails in soil communities outside their ecological optimum. Under these conditions, the community demonstrates the concentration of domination and decreased species richness due to the disappearance of closely related invertebrate species largely in biologically regressing groups.

Animals↗
PubMed1985

Retinal S-antigen epitopes in vertebrate and invertebrate photoreceptors.

Monoclonal antibodies specific for the retinal S-antigen were obtained by hybridization of spleen cells from a BALB/c mouse immunized with bovine S-antigen and NS-1 myeloma cells. Five selected antibodies specifically labeled the photoreceptor cells of the retina by immunofluorescence. Whereas antibody S9E2 only reacted with bovine S-antigen, the other antibodies showed interspecies cross-reactivity. They were used for the characterization of specific epitopes of S-antigen in photoreceptors from a wide range of species representative of various classes of vertebrates and invertebrates. The presence of S-antigen in distant species (vertebrates, Amphioxus, nemerteans, annelids, molluscs) indicates a high phylogenetic stability and suggests an important role for this protein in photoreceptor function.

Animals↗
PubMed1989

Characterization and comparison of epsilon-crystallin and lactate dehydrogenases in the lenses of vertebrates and invertebrates.

Screening of lens homogenates for the identification of lactate dehydrogenases was undertaken for the representative species from five major classes of vertebrates plus the cephalopod of invertebrates. The duck and caiman lenses appeared to contain the highest enzymatic activity of this glycolytic enzyme among all species examined. Biochemical isolation and characterization of epsilon-crystallins from the duck and caiman lenses revealed differences between these structural crystallins and the authentic lactate dehydrogenase of the avian heart regarding some of the kinetic properties. This is in contrast with the claim that duck epsilon-crystallin is identical to heart-type lactate dehydrogenase.

Amino Acids↗
PubMed1988

Comparative strategies of pigmentary regulation in invertebrates.

This brief survey of color change strategies among invertebrates has dealt mainly with the diversity encountered in three aspects of their pigment cell biology: (1) the types of chromatophores they possess, (2) the control of color changes by nerves or hormones if the chromatophores are not acting only as independent effectors and (3) the functions of the physiological color changes these animals exhibit. Of these three topics, much less is known about the last one, the functions of the color changes, than about the first two. There has been much hypothesizing about the functions of color changes and the advantages such changes presumably confer, but relatively few data have been generated to support the hypotheses.

Animals↗
PubMedDate not supplied

[Binding of iron ions by shielding eye pigments of vertebrates and invertebrates--melanosomes and ommochromes].

Melanosomas of eye pigment epithelium tissue of vertebrates, synthetic DOPA-melanin and ommochromas from eye of invertebrates bind effectively bivalent iron ions. Constants of the binding process are calculated. Endogenic iron concentration in melanosomas of the frog eye pigment epithelium is determined. A conclusion is drawn that mechanism of antioxidation action of shielding eye pigments may include Fe2+ ion binding into inactive components.

Animals↗
PubMed1985

[Effect of polysaccharides isolated from marine invertebrates on various functions of T- and B lymphocytes].

The effect of bioglycans from sea invertebrate on the level of the rosette forming cells (RFC) in the spleen, development of the delayed type hypersensitivity (DTH) induced by sheep red blood cells (SRBC) and the levels of hemagglutinins and hemolysins in the blood serum was studied in experimental animals. It was shown that the polysaccharides administered parenterally in a single dose had an effect on the humoral and cellular immunity. Under the effect of these preparations the level of the RFC in the spleen of the mice increased, with the increase of the RFC belonging to the lymphocyte T2- and B-subpopulations being more intensive. The use of the polysaccharides increased the mean geometric titers of serum antibodies. The polysaccharides administered at different periods with respect to the immunization and antigen challenge either decreased or increased the DTH induced by SRBC.

Adjuvants, Immunologic↗
PubMedDate not supplied

[Rapid method for the determination of choline kinase activity. Choline kinase in marine invertebrates].

A quick sensitive test is suggested to determine choline kinase (EC 2.7.1.32). The method includes incubation of a substrate with enzyme in microvolume and separation of the formed phosphorylcholine from the initial choline by high-performance thin-layer silica gel chromatography. The procedure of determination is simple, reproducible and takes no more than 30 min. The method reveals high activity of choline kinase in some marine invertebrates. Certain features of the enzyme from the intestine of strongylocentrotus intermedius are described.

Animals↗
PubMedDate not supplied

Relationships between specialized cells, capillaries and intermediary cytofibrillary elements. XIIth note. Biological evolution of the respiratory stereotype and subsystem in invertebrates.

This note presents the respiratory stereotype and subsystem in invertebrates, developing the previous notes on the emunctory stereotype and subsystem (Xth and XIth notes). As in the previous ones, Cannon's homeostasis conception and Bertlanffy's theory of systems were corroborated with Needham's theory of internal laws and of limits of organizational biological levels, and with the author's theory of biological stereotypes (Mârza, Repciuc, Eskenasy, 1962). Four links of the respiratory stereotype (Rsp. Stp.) and subsystem (Rsp. SS) were distinguished. The respiratory subsystem was differentiated when, in triblastic animals, the organizational level of higher worms and of their offsprings was reached. The four links of the Rsp. Stp. are: the Ist link is represented by the oxidoreduction processes of tissue and organ cells; the IInd is the internal conveying link of O2 and CO2; the IIIrd comprises the osmotic surfaces changes and the transport of gases inwards the branchiae or lungs, and later by the water (respectively air)--blood barrier; the IVth link is formed from the structures and mechanisms of rhythmic movements which significantly increase the exchanges at the barrier level. Each link has its specific properties. The gradual evolution of each link and of the vicarious organs of gas exchange is dwelt upon, as well as the interactions between the respiratory subsystem and the other homeostasis subsystems. The theoretical interpretation of the Rsp. Stp. and Rsp. SS evolution also resorted to the theories of stabilizing selection (Schmalhausen, 1949), of canalizing selection (Waddington, 1975 and of disruptive selection (Simpson, 1953; Mayr, 1970).

Animals↗