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PubMed1983

[Possibility of using the larvae of anuran amphibians as a test model for the quantitative determination of hypophyseal hormones].

A possibility to use the larvae of ecaudate amphibia as a test model for the quantitative determination of certain hypophyseal hormones has been shown. The physiological reactions of the pigmentary cells in tadpoles of Rana temporaria can be used for a quick and exact testing of the adrenocorticotropic hormone preparations (ACTH): corticotropin and Zn-corticotropin. Evidently the method elaborated for the biological testing of hypophyseal hormones may be used in the production of the endocrinous preparations as a quick assessment of melanocyte-stimulating hormones in integral raw and sublimated hypophyses.

Adrenocorticotropic Hormone↗
PubMed1984

Immunologic characterization of the photoreceptor outer segment cyclic GMP phosphodiesterase.

High affinity (KD approximately 1 X 10(-9) M) monoclonal antibodies (ROS-1 and ROS-2) were prepared to bovine photoreceptor outer segment cGMP phosphodiesterase. ROS-1 immunoadsorbed greater than 95% of the cGMP phosphodiesterase activity from a detergent-solubilized bovine retina extract while ROS-2 immunoadsorbed only a subfraction of the same activity. Sodium dodecyl sulfate gel analysis of these immunoadsorbates demonstrated that ROS-1 and ROS-2 specifically adsorbed only peptides that comigrated with purified rod outer segment phosphodiesterase. Limited trypsin digestion of purified rod outer segment phosphodiesterase greatly reduced its affinity for ROS-1 but not ROS-2. When a crude heat-stable inhibitor fraction was added back to the activated enzyme, the affinity for ROS-1 was restored, suggesting that the inhibitor was necessary for ROS-1 binding. ROS-1 but not ROS-2 was found to inhibit cGMP phosphodiesterase which had been activated either by dilution or guanyl nucleotide. The inhibitory property of ROS-1 may provide a useful probe for directly studying the effects of this phosphodiesterase on the phototransduction response in the retina. Sodium dodecyl sulfate gel analysis demonstrated that the ROS-1 immunoadsorbates from mammals, fish, and amphibia contained peptides of similar mobility. Immunocytochemistry performed with ROS-1 and fluorescein isothiocyanate-conjugated rabbit anti-mouse IgG localized the antigenic determinant to both rod and cone outer segments suggesting the presence of an antigenically similar phosphodiesterase in both types of photoreceptors.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1984

Freeze-fracture of Rana pipiens gonad anlage: study of primordial germ cells and other cellular types.

Freeze-fracture was used to study Anura Amphibia primordial germ cells (PGCs) from the time when they have invaded genital ridges until the time when sexual differentiation has begun. We observed tight junctions with a variety of configurations including linear, macular, and extensive occluding cross-linking complexes. True gap junctions were not observed. Rod-shaped particles were found disseminated among particles on the P fracture faces of the germ cells.

Animals↗
PubMed1981

[Acute toxicity of two phenylcarbamates: propham and chloropropham].

The bibliographic data dealing with the acute toxicity of two phenylcarbamates, propham and chloropropham, are not very precise an often contradictory. This work is a restatement and also a demonstration of the high sensitivity of the aquatic animals that we have tested (Amphibia and Crustacea) in comparison with the Mammals (rat and mouse).

Animals↗
PubMedDate not supplied

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

The author continues in aquatic vertebrates the study of the evolution of the respiratory stereotype initiated in the XIIth note of this series and carried out in the light of the systemic conception (Bertalanffy), of Needham's theory of order in nature, and of the theory of biological stereotypes (Mârza, Repciuc, Eskenasy). The stability of some characters of the respiratory stereotype inherited by vertebrates from invertebrates is pointed out. The respiratory stereotype in vertebrates gradually passed from the respiration of water-dissolved oxygen through branchiae and skin, to the concomitant uptake of this form and of air oxygen (through buccopharyngeal formations, gaseous bladder or rudimentary lungs in osseous fishes), the double respiration (in Amphibia) and later the air respiration in Reptilia. The five steps of this gradual evolution are described, as well as the conditions of the evolution from crossopterygians to Tetrapoda (amphibians and reptiles).

Air↗
PubMedDate not supplied

[The role of an evolutionary approach to the study of the structure and function of gangliosides].

A comparative-biochemical study of gangliosides is an effective approach to understanding their structural diversity and functions. Certain new gangliosides which are essential in processes occurring in the nerve and other tissues of vertebrates (tetra- and pentasyalogangliosides, trisyalogangliosides with a short carbon chain and others) were first found when investigating fish and amphibia brain and then in the mammalian nerve tissue. Comparative studies made it possible to characterize a new aspect of the functional role of gangliosides, their adaptation functions. Investigations in the content and composition of gangliosides in representatives of different taxonomic groups of animals are important for a more profound understanding of other functions of these compounds, their role in the processes of the nerve impulse transmission, intercellular interaction, etc. Comparative-immunochemical studies of gangliosides seem to be also promising and timely.

Adaptation, Physiological↗
PubMed1978

[Histochemical characteristics of the secretory cells of gastric glands compared].

The work is dedicated to complex histological studies of the secreting cells in the gastric fundal glands, in their comparative aspect. In the representatives of Amphibia, Reptilians and birds, histochemical differentiation of oxyntopeptic cells was demonstrated to be independent on the peculiarities of the animal nutrition. In mammals, histochemical characteristic of the carbohydrate component in the glandular secreting cells depends on the type of nutrition.

Amphibians↗
PubMed1984

Regeneration and pattern formation in planarians. I. The pattern of mitosis in anterior and posterior regeneration in Dugesia (G) tigrina, and a new proposal for blastema formation.

Mitotic activity during regeneration in the planarian Dugesia (G) tigrina shows a biphasic pattern, with a first maximum at 4-12 h, a second and higher maximum at 2-4 days, and a relative minimum in between. The first peak is mainly due to pre-existing G2 cells entering mitosis shortly after cutting, whereas the second maximum is due to cells that divide after going through the S period from the onset of regeneration. From a spatial point of view, the highest mitotic values are found in stump (postblastema) regions near the wound (0-300 micron), though regions far from it also show increased mitotic values but always lower overall values. As regeneration continues the postblastema maximum shifts slightly to more proximal regions. In contrast, no mitosis has been found within the blastema, even though the number of blastema cells increases steadily during regeneration. The results suggest that blastema in planarians forms through an early accumulation of undifferentiated cells from the stump to the base of blastema. The results obtained demonstrate that blastema formation in planarians occurs through mechanisms somewhat different to those shown to occur in the classical epimorphic models of regeneration (Annelida, Insecta, Amphibia), and suggest that planarian regeneration could represent an intermediate stage between morphallactic and epimorphic modalities of regeneration.

Animals↗
PubMed1984

Ecology of leishmaniasis in the south of France. 19. Determination of the hosts of Phlebotomus ariasi Tonnoir, 1921 in the Cévennes by bloodmeal analyses.

Engorged sandflies were collected using 58 CDC light traps set up nightly for 5 weeks at 12 stations in the commune of Roquedur, Gard, France, in the Cévennes focus of leishmaniasis. Of 782 engorged females, 593 were Phlebotomus ariasi, 3 were P. mascittii and 186 were not identified. Using the precipitin ring test and counter-current immuno-electrophoresis, the bloodmeals were tested with antisera to man, leporids, rodents, canids, mustelids, equids, suids, bovids, birds, lizards and amphibia. Of 530 identified bloodmeals, 2 were avian blood, 26 were mixed meals of mammalian blood and 25 were meals taken from unidentified mammals. Of the 477 other sandflies, 211 (44.2%) had fed on canids, 107 (22.4%) on man, 70 (14.7%) on bovids (presumed to be cattle at one station and goats elsewhere), 33 (6.9%) on leporids (probably mostly domesticated rabbits), 26 (5.5%) on mustelids (probably badgers), 17 (3.6%) on horses and 13 (2.7%) on rodents (probably brown rat). The proportions of feeds on different mammals varied according to their availability at each station. When both man and dog were equally available, the dog was preferred. The finding that, away from human habitation, P. ariasi commonly feeds on mustelids suggests the need for a reappraisal of animals of this family as possible reservoirs of leishmaniasis in the Cévennes.

Animals↗
PubMed1983

[Innervation of the lungs in vertebrates and man].

The adrenergic and cholinergic innervation of the lungs have been studied by means of Falck and Koelle methods in amphibia (Rana temporaria), reptile (tortoise), vertebrates (white rat, domestic cat) and in the man. It has been found that as the structure and function of the lungs become more complicated, their innervation apparatus structure becomes more complex with increasing number of the adrenergic and cholinergic components in it. The distribution density of the adrenergic and cholinergic neural fibers in the lungs increases from the lower vertebrates to the higher ones. The distribution density of the cholinergic neural fibers in the bronchial wall decreases with diminishing of their caliber.

Adrenergic Fibers↗
PubMed1984

[Development of the neural apparatus of blood vessels in the common frog in ontogenesis].

The neural apparatus of the aorta, abdominal vein, ischiatic, femoral, pulmonary and caudal vessels has been studied histochemically in tadpoles (the 30th-50th stages of development) and in 1-year-old animals. It has been stated for the first time that in the frog, a representative of the Amphibia class, like in mammals and birds, formation of the adrenergic apparatus in various vessels does not take place simultaneously. For instance, the first adrenergic fibers in the hind limb vessels appear much earlier than in other arteries and veins. The process of the adrenergic innervation development and its completion in vessels of various areas is taking its course differently. In the aorta and in the abdominal vein the formation of the adrenergic plexus develops as increasing density and amount of the mediator in the adrenergic fibers and is completed with maturation in an adult animal. In contrast to these vessels, maturation of the adrenergic apparatus in the hind limb arteries and veins takes place during a shorter interval and is completed at the end of metamorphosis AchE-containing fibers are revealed in tadpoles, as well as in a mature frog only in the aortal arc and in the pulmonary artery. In these vessels the development of cholinergic innervation leaves behind that of the adrenergic innervation, as it does in the vessels of Mammalia, and the human subject.

Adrenergic Fibers↗
PubMed1983

[Histochemical characteristics of the epitheliocytes of the avian glandular stomach].

A complex histochemical investigation has been undertaken to study the epithelial lining of the glandular stomach in birds having various types of nutrition. The protective barrier of the avian stomach has been found to be characterized as a resistant (mucosal) barrier, with neutral glycoproteins, sialo- and sulphoglycoproteins as its components. Differences in histochemical properties of the epitheliocyte secretion have been described in birds with different types of nutrition. They are connected with various correlation of carbohydrates and proteins in the composition of the micromolecular glycoprotein complex. The data obtained are compared with those concerning the histochemical properties of the stomach in amphibia and reptiles which have the mucous membrane structure similar to that in the avian stomach.

Animals↗
PubMed1983

The 22 S cylinder particles of Xenopus laevis. II. Immunological characterization and localization of their proteins in tissues and cultured cells.

Cylinder-shaped particles of 10 nm diameter were isolated from nuclei of Xenopus laevis oocytes and purified by sucrose gradient centrifugation and DEAE-Sephacel chromatography. Antibodies to protein constituents of these isolated particles were elicited in guinea pigs and examined by immunoblotting and immunoprecipitation techniques as well as by immunofluorescence microscopy. The antibodies reacted with only two out of the 12 constituent polypeptides characteristic for these particles when examined in the denatured state by the immunoblotting technique, including the largest component of Mr 30 000, but were able to precipitate the whole ensemble of these polypeptides in immunoprecipitation experiments, in agreement with the notion that these proteins form the 22 S particle complex. The antibodies displayed a rather narrow range of interspecies cross-reactivity, showing reaction with cells of other amphibia but not with avian and mammalian cells. In oocytes as well as in transcriptionally active somatic cells the antigen was localized in the nucleoplasm, excluding nucleoli, as well as in the cytoplasm, usually suggesting a higher concentration in the nucleoplasm. During mitosis, the proteins were dispersed throughout the cytoplasm whereas the chromosomes were negative. Inactive cells such as mature erythrocytes, spermatids and spermatozoa were negative. These immunolocalization findings support our conclusion based on fractionation studies that the cylindershaped particles and their protein constituents occur both in the nucleoplasm and the cytoplasm of a broad range of cell types.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Ultrastructural characteristics associated with the anchoring of corneal epithelium in several classes of vertebrates.

The electron microscopic examination of the basal cells of corneal epithelium certain species of Mammalia, Avia, Reptilia, Amphibia and Pisces was directed particularly towards the hemidesmosomes. Sections cut normal to the basal lamina and sections cut parallel to it were studied in order to establish the number, shape and distribution of the hemidesmosomes. Four basic types of hemidesmosome distribution were recognised among a limited representation of the classes studied. (1) Linear chains of hemidesmosomes (Mammalia, Rana, Bufo). (2) Rosette arrangement of hemidesmosomes surrounding pockets of basal plasma membrane (Avia, Anolis, Xenopus). (3) Punctate hemidesmosomes with no arrangement (Thamnophis). (4) Absence of hemidesmosomes (Carassius). All animals showed a basal lamina, basal pinocytotic vesicles, anchoring filaments, tonofilaments, and interdigitating foot-processes. It is suggested that anchoring filaments deserve to be studied more thoroughly in certain other types of epithelia which do not have focal hemidesmosomes, but require firm anchorage to a basal lamina.

Animals↗
PubMed1981

[Changes in the intestines of obstetrical toad (Alyte obstetrician) larvae during spontaneous metamorphosis or metamorphosis induced by thyroxine. Morphometric study and changes in the protein/DNA ratio].

During spontaneous metamorphosis of Alytes obstetricans tadpoles (Anuran Amphibia), the gut undergoes important modifications. The gut weight/total weight and gut length/body length decrease by stage XVIII. They reach maximum reductions of 83 and 90%, respectively, by stage XXIII. Tail regression begins only by stage XX. The intestinal protein/DNA ratio peaks to a maximum by stage XIX, decreases greatly by stage XX then increases slightly by stage XXII. During thyroxine-induced metamorphosis, the morphometric changes are observable after a lag period of 36-48 hs, prior to detectable tail reduction. The intestinal protein/DNA ratio of T4-treated tadpoles remains constant and no difference with control data is noted.

Animals↗
PubMed1982

[Detection, using fluorescent lectins, of specific carbohydrate chains in primordial germ cells of anuran amphibians].

A study of primordial germ cells (PGC) of Amphibia Anura was carried out after treatment of sections by different fluorescein isothiocyanate conjugated lectins (FITC-lectins). Specific labelling on the PGC is obtained with lectins, the activity of which is inhibited by D-galactose or N-acetyl-galactosamine. These osidic groups appear to be located more specifically on the PGC. The same labelling pattern is not obtained with lectins possessing major affinity for mannose, glucose, fucose and N-acetyl-glucosamine. Furthermore, changes in labelling pattern are observed during migration of PGC. It is suggested that D-galactose and N-acetyl-galactosamine might be related to membrane activity of PGC during migration. Ultrastructural study of the visualization of cell surface carbohydrates supplies some information on the localisation of these lectins receptors.

Animals↗
PubMed1980

Actin synthesis during the early development of Xenopus laevis.

Cytoskeletal beta and gamma-actin are amongst the most rapidly made proteins of oocytes, blastulae and late embryonic stages of Xenopus laevis but, relative to other proteins, the rate of synthesis is low in the egg or cleaving embryo, although the messenger RNA is present in comparable amounts at the different stages. Actin synthesis therefore involves post-transcriptional regulation. alpha-Actin, the actin class characteristics of straited muscle cells, is first detectable in late gastrulae and it is an abundant newly synthetized protein from the neurula stage onwards. mRNA template activity for this protein is not detectable before the gastrula stage. Thus alpha-actin synthesis probably reflects new gene action, confined to part of the embryo, for alpha-actin only appears in the section which includes presumptive skeletal muscle cells. It therefore constitutes the earliest cyto-specific protein so far demonstrated in Amphibia. When tadpole tail poly(A)-containing mRNA is injected into oocytes and eggs alpha-actin synthesis is seen in both cases. Extensive evidence for the identification of the actins is presented. This is based on location of synthesis, DNase-I binding and partial peptide mapping.

Actins↗
PubMed1982

Relationships between DNA content and cell morphometric parameters in reptiles.

The relationships between the genome size and various cellular morphometric parameters have been, studied in 38 reptilian species. The nuclear volume, the cell volume and the cell surface area show a direct, linear and statistically significant correlation with the nuclear DNA content; the cell surface/cell volume ratio tends to decrease as DNA increases. The results are similar to those previously observed in Amphibia, which suggests, that at least in poikilothermic vertebrates, the correlations between DNA amounts and cell sizes are controlled by substantially similar mechanisms. A comparison of the average variations of the various morphometric parameters among each other and with the average variation of the genome size suggests that these parameters are not regulated all in the same way.

Animals↗