Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| the reticuloendothelial system in the biology of the alpine newt. | 1946 | 20992370 | |
| hybridization in triturus: description of a method by which reciprocal hybrids from triturus taeniatus and triturus alpestris can be obtained. | 1947 | 20266735 | |
| [topographical variations in stainability of the cortex of the symmetrized egg of triturus alpestris with nile blue and neutral red]. | 1952 | 13020269 | |
| [additional data on variations in permeability of cortex of triturus alpestris egg to nile blue]. | 1957 | 13500712 | |
| [results of the change of central and lateral parts of the primary organizer in a young gastrula in triturus alpestris and pleurodeles waltlii]. | 1957 | 13473271 | |
| [effect of a thermal gradiant on the embryonic development of triturus alpestris]. | 1958 | 13597429 | |
| [effects of the return of the ovum of triturus alpestris on the gradient of cortical permeability]. | 1958 | 13609103 | |
| [inductive action of the prechordal plate on the ectoblast that was previously influenced by the chorda (triturus alpestris)]. | 1958 | 13605445 | |
| [demonstration of the cortical permeability gradient of the egg of triturus alpestris and its modifications under the influence of certain physical agents (rotation of the egg, centrifugation, ultrasounds)]. | 1959 | 13817327 | |
| [inversion of the sexual phenotype (feminization) of triturus helveticus raz. and triturus alpestris laur, following gynogenous treatment by estradiol benzoate administered during the larval stage]. | 1960 | 13826151 | |
| [effects of ultrasounds on the structure and cortical permeability of the egg of triturus alpestris]. | 1960 | 13723559 | |
| [modifications in the structure and the cortical permeability as well as embryonal development after moderate centrifugation of the intact egg of triturus alpestris]. | 1961 | 13723560 | |
| [influence of castration on the rate of regeneration of the extremities in the newt, triturus alpestris laur]. | 1963 | 14081739 | |
| [research on internal determination of cloacal development in the high alpine newt]. | 1963 | 13997320 | |
| [demonstration of a biehnial reproductive cycle in the alpine newt]. | 1963 | 13997319 | |
| [experimental studies on reissner's fiber in triturus alpestris laur]. | 1964 | 14335726 | |
| an electron microscope study of the endoplasmic reticulum in newt notochord cells after disturbance with ultrasonic treatment and subsequent regeneration. | ultrasonic treatment of the tails of triturus alpestris tadpoles, at intensities of 8 to 15 watts/cm(2), at 1 megacycle/sec., for 5 minutes, disrupted the epidermis and caused pycnosis in individual cells of the muscle and neural tube, but caused no damage to the notochord that could be detected by light microscopy. electron microscopy showed that this ultrasonic treatment disordered nearly all the endoplasmic reticulum (er) of the notochord cells into irregularly rounded vesicles, but within 3 ... | 1964 | 14105208 |
| [synthesis of ribonucleic acids in whole embryos and in the isolated ectoderm of triturus alpestris]. | 1965 | 4160387 | |
| [secretory activity of the flexural and subcommissural organs in the early developmental stages of triturus alpestris laur]. | 1965 | 5870925 | |
| [histochemistry of the mature oviduct of the mountain triturus alpestris l]. | 1966 | 4228358 | |
| tubular elements associated with yolk platelets in triturus alpestris. | 1966 | 5951724 | |
| a reinvestigation of some of the tissue movements involved in the formation of the neural tube and the eye/lens system of triturus alpestris and xenopus laevis. | 1966 | 5962694 | |
| [embryonal skin grafts between ambystoma mexicanum shaw, pleurodeles waltlii michah. and triturus alpestris laur.; phenomena of tolerance and rejection]. | 1967 | 4963534 | |
| [embryonic skin grafts between ambystoma mexicanum shaw, pleurodeles waltlii michah and triturus alpestris laur; phenomena of tolerance and rejection]. | 1967 | 4989164 | |
| [on the morphogenesis of the opisthonephron in triturus alpestris]. | 1968 | 4174385 | |
| [situs inversus of the newt (triturus alpestris) after uv-irradiation of gastrulae]. | gastrulae (harrison 9-13), and for comparison neurulae (harrison 15-17) oftriturus alpestris were irradiated with mixed ultraviolet light of various doses and at various body regions. bilateral irradiation leads to a markedly higher mortality than does unilateral irradiation. gastrulae possess a better regulation capability than neurulae. the frequency of alterations of the situs (irregularities, partial and total inversions), lethality and rate of malformations are dose dependent. irradiation o ... | 1968 | 28304597 |
| [larval form and visceral situation in the newt (triturus alpestris) after one-sided uv-irradiation of neurulae and postneurulae]. | neurulae and postneurulae oftriturus alpestris (up toharrison stage 29) were irradiated with mixed ultraviolet light from the left, right, dorsal or ventral side, respectively. the duration of treatment ranged from 1-600 seconds. visible effects occurred already after a 5 sec irradiation. embryos and larvae showed defects of histological and external features. in this paper "inversions" are distinguished from "partial inversions". in "inversions" the curvature of the gut and the liver sinus (or, ... | 1968 | 28304483 |
| [influence of the electrical current upon the situs viscerum of triturus alpestris]. | neurulae (harrison 15-17) oftriturus alpestris were kept within an electrical set up for 1 hour. at a later stage the larvae showed irregularities and inversions of their viscera in a much higher frequency than the untreated controls. | 1968 | 28304526 |
| [relative antigenicity of tegument embryonic heterografts in urodele amphibians: ambystoma mexicanum shaw, triturus helveticus raz., triturus alpestris laur. and pleurodeles waltlii michah]. | 1969 | 4979133 | |
| negative staining and adenosine triphosphatase activity of annulate lamellae of newt oocytes. | semi-isolated annulate lamellae were prepared from single newt oocytes (triturus alpestris) by a modified callan-tomlin technique. such preparations were examined with the electron microscope, and the negative staining appearance of the annulate lamellae is described. the annulate lamellae can be detected either adhering to the nuclear envelope or being detached from it. sometimes they are observed to be connected with slender tubular-like structures interpreted as parts of the endoplasmic retic ... | 1969 | 4183078 |
| [the situs viscerum of triturus alpestris after uv-irradiation in pregastrula stages]. | uncleaved eggs, eggs with 4, 32-64 blastomeres and blastulae were irradiated with different doses of uv-mixed light, only onesided-equatorial, -animal or -vegetativ. in no case did the uv-irradiation effect a statistically significant increase of whole or partial visceral inversions. these happened only after irradiation of young gastrulae, especially when the vegetative germ part with the blastopore was exposed. | 1969 | 28304441 |
| [electrophoresis study of serum proteins from xenoplastic chimera between urodele amphibia: pleurodeles waltlii michah. and triturus alpestris laur]. | 1969 | 4980276 | |
| [the situs viscerum in the newt (triturus alpestris) after material defects in the ectoderm of the blastula]. | in the blastula stage oftriturus alpestris roundish pieces were removed from the animal half of the embryo, which consisted of undetermined ectoderm; some of them could perhaps contain some mesoderm on their vegetal edge. since the median plane could not be ascertained in this stage, a chance distribution around the animal-vegetal axis has to be assumed.most of the embryos developed to externally normal larvae. the gut situs of 193 larvae was regular in 97.9% of the cases, median in 0.5% and inv ... | 1970 | 28304462 |
| [action of carcinogenic substances on tail regenerates among triturus alpestris laur. (amphibia, salamandridae)]. | 1971 | 5002515 | |
| [diurnal rhythm in salamanders]. | 1. the locomotor activity of european salamanders differs from species to species. at all stages of development triturus vulgaris is more light-active, salamandra salamandra is dark-active, while triturus alpestris and cristatus occupy an intermediate position. 2. the activity of the larvae is high but the rhythm is not very pronounced. triturus larvae are less dark-active than adults (fig. 2). 3. periodism disappears completely during metamorphosis but after some weeks of terrestrial life a diu ... | 1971 | 28313280 |
| [serum proteins and chimerism of the liver of chimeras among the urodelan amphibia: pleurodeles waltlii michah. and triturus alpestris laur]. | 1971 | 4995276 | |
| intramitochondrial complexes of atypical structures in hepatocytes of triturus alpestris (laurenti). | 1972 | 5036576 | |
| [relationships between structure and chemical composition of spermatozoa in the newt, triturus alpestris laur]. | 1972 | 4672858 | |
| susceptibility of eggs and larvae of triturus alpestris to aflatoxin b1. | 1972 | 4677210 | |
| electron spin resonance studies on living cells. 3. development of single individuals in triturus alpestris. | 1972 | 4340784 | |
| [the effect of triethylenmelamin (tem) on the retinal development of the newt (triturus alpestris): an electron microscopic study]. | larvae oftriturus alpestris (stages according to glaesner: 27, 34, 39 and 43) were kept for 24 hours in a solution containing 10-4 gr triethylenmelamin (tem) per ml tap water. thereafter, they were further grown in pure tap water. light microscopically, a fading of mitotic figures and an enlargement of cells prepared to divide were observed within the retina. pyknotic nuclei and cell death occured in the zones of cell differentiation. the various developmental stages were differently affected by ... | 1972 | 28304722 |
| [adrenergic innervation of the hypophysis of triturus alpestris]. | 1972 | 4625351 | |
| the formation of the mesoderm in urodelean amphibians : iv. qualitative evidence for the purely "ectodermal" origin of the entire mesoderm and of the pharyngeal endoderm. | xenoplastic recombinations of animal and vegetative parts ofambystoma mexicanum and triturus alpestris blastulae, and similar recombinations of parts of3h-thymidinelabelled and unlabelledambystoma mexicanum blastulae demonstrate convincingly that the vegetative part (zone iv, see nieuwkoop, 1969a) of such a recombinate does not contribute to mesoderm formation, but exclusively forms endodermal derivatives. in contrast, the animal cap of the blastula (zones i.ii)-which only gives rise to atypical ... | 1972 | 28304624 |
| [rosette formation in splenic cells of the urodele amphibia triturus alpestris laur. and pleurodeles waltlii michah]. | 1972 | 4631124 | |
| the ultrastructure of amphibian ectoderm treated with an inductor or actinomycin d. | amphibian (triturus alpestris) ectoderm was isolated and after 2-16 days in culture examined by electron microscopy. it has been shown that the ectoderm, formerly called "undifferentiated ectoderm", forms in part ciliated epithelial cells, which cannot be distiguished from the cells of the epidermis, which has developed in situ (except for the alignment of the cells which depends on the mesenchyme underlying the epidermis). the ultrastructure of the cilia is similar to that of cilia of protozoa ... | 1973 | 28304798 |
| [development of lymphoid organs in the urodele amphibian triturus alpestris laur.; skin allograft tolerance after larval thymectomy]. | 1973 | 4577877 | |
| [ultrastructural study of the evolution of interneuronal junctions during the maturation of the central nervous system of triturus alpestris (amphibian, urodele)]. | 1973 | 4785084 | |
| [spectral sensitivity of triturus alpestris (amphibia, urodela) during aquatric and terrestrial life]. | 1973 | 4737718 | |
| 1. the q o2 of salamandra atra and triturus alpestris varies with season. this periodicity appears to be largely endogenous, but in autumn an exogenous cold stimulus is required for the animals to enter the winter phase. 2. cold (10°) acclimation stimulates q o2 of t. alpestris in spring and autumn, whereas in summer q o2 is stimulated by warm (20°) acclimation. 3. in both species respiration of winter animals is insensitive to acute temperature increases from 5 to 15°. 4. if for several days th ... | 1974 | 28308631 | |
| the ectomesenchymal-endodermal interaction-system (eeis) of triturus alpestris in tissue culture. i. observations on attachment, migration and differentiation of neural crest cells. | 1974 | 4442672 | |
| effects of actinomycin d on the association of newly formed ribonucleoproteins with the cistrons of ribosomal rna in triturus oocytes. | the effect of actinomycin d(amd) on the association of the nascent ribonucleo-protein (rnp) fibrils containing the precursors of ribosomal rna (pre-rrna) with their template deoxyribonucleoprotein (rdnp) strands has been studied in lampbrush stage oocytes from triturus alpestris. ovary pieces were incubated in vitro either in media containing radioactive ribonucleosides and then, for various times, in solutions containing 25 mug/ml amd, or were directly exposed to the drug. the ultrastructure of ... | 1975 | 1127008 |
| the rejection of intra- and intersexual skin grafts in newts (triturus vulgaris and triturus alpestris). | 1975 | 764953 | |
| microfilaments in the external surface layer of the early amphibian embryo. | a comparison was made by transmission electron microscopy of the microfilaments in the surface layers of the early embryos of triturus alpestris and xenopus laevis at stages of development up to neurulation. actin-like filaments which bound heavy meromyosin (hmm) were found in cell extracts of all stages, but were comparatively rare in the newly fertilized egg. ten nm microfilaments were present throughout development in xenopus, and from the mid-neurula stage in triturus. both kinds of microfil ... | 1975 | 50397 |
| [activity and isoenzymes of lactate dehydrogenase in tissues of amphibians (xenopus laevis, ambystoma mexicanum, triturus alpestris and vulgaris) and the response in the fat body of xenopus males to gonadotropin injection (author's transl)]. | lactate-dehydrogenase activity was determined by the optical test method using pyruvate as substrate and the isoenzymes were separated by vertical starch gel electrophoresis. species-specific and organ-specific characteristics of the total activity and the isoenzyme patterns of the four amphibian species are compared with those of rat and mouse. application of gonadotropin increases the amount of soluble protein and the lactate-dehydrogenase activity in the fat body of xenopus and the isoenzyme ... | 1975 | 1176091 |
| [evolution of xenografts of embryonic gonads and juvenile ovaries from ambystoma mexicanum shaw, transplanted into triturus alpestris laur]. | gonad primordium of ambystoma mexicanum when grafted at tail-bud stage on triturus alpestris is indefinately tolerated. testis or ovaries derived from those grafted embryonic gonads follow their differentiaion and reach sexual maturity. axolotl juvenile ovaries transplanted in triturus alpestris are also tolerated; the ovocytes achieve the entire vitellogenesis but are not able to be laid. | 1975 | 809199 |
| [studies of the activity and the isoenzyme patterns of ldh during the development ofxenopus laevis, triturus alpestris andvulgaris andambystoma mexicanum]. | the present paper deals with studies of the activity and the isoenzyme patterns of ldh during the development ofxenopus laevis, triturus alpestris andvulgaris andambystoma mexicanum. activity measurements have been performed with the optical test method using pyruvate as substrate and the isoenzymes have been separated by vertical starch gel electrophoresis. a) substrate optima for enzyme extracts from embryonic stages 1-38 are identical in the three speciestriturus alpestris, ambystoma mexicanu ... | 1975 | 28304825 |
| incomplete antibodies and immunoglobulin characterization in adult urodeles, pleurodeles waltlii michah. and triturus alpestris laur. | humoral immunoglobulin synthesis has been studied in two adult urodeles, pleurodeles waltlii michah. and triturus alpestris laur. following srbc immunization. the specific antibody response is detected after a long period of immunization and is due exclusively to 'incomplete' antibodies which are unable to induce agglutination. the antibody titre is essentially dependent on the number of stimulations rather than on the dose or nature of the antigen (papainized or normal erythrocytes). antibodies ... | 1975 | 49296 |
| incorporation of tritiated cytochalasin b into ectodermal explants of the amphibian gastrula. | ectodermal explants from gastrulae of triturus alpestris were exposed to tritiated cytochalasin b (5 and 10 mug/ml) for 1/2-2 1/2 h. the flat explants failed to heal into compact spheres and the component cells gradually rounded up. radioactivity in the fixed and sectioned material was analysed by light and electron microscopic autoradiography. silver grains were found predominantly over the yolk platelets, but were also scattered over other cellular components. areas containing pigment granules ... | 1976 | 978128 |
| regulation of transcription of genes of ribosomal rna during amphibian oogenesis. a biochemical and morphological study. | natural changes in the transcription of rrna genes were studied in nucleoli from three oogenic stages of the newt triturus alpestris with electron microscope, auto-radiographic, and biochemical techniques. from determinations of the uridine triphosphate pool sizes and [3h]uridine uptake, phosphorylation, and incorporation into 28s and 18s rrnas in vivo it was estimated that the rate of rrna synthesis was about 0.01% in previtellogenic oocytes and 13% in mature oocytes when compared to midvitello ... | 1976 | 1262400 |
| biosynthesis of 11-deoxycorticosteroids and androgens by the ovary of the newt triturus alpestris alpestris laur. | 1977 | 598691 | |
| influence of cyclic nucleotides on amphibian ectoderm. | isolated amphibian (triturus alpestris) gastrula ectoderm was treated with cyclic nucleotides for 24 h and cultured up to 12 days. explants treated with$cyclic n6-monobutyryl-adenosine-3'∶5'-monophosphate, cyclic dibutyryladenosine-3'∶5'-monophosphate and cyclic dibutyrylguanosine-3'∶5'-monophosphate in a concentration of 10-3 and 10-5 m did not differentiate into mesoderm- or endoderm-derived tissues. the number of explants with small neural and neuroid structures did not exceed the percentage ... | 1977 | 28305145 |
| the ectomesenchymal-endodermal interaction system of triturus alpestris in tissue culture: morphological and histochemical characterization of developing neural derivatives. | in the ectomesenchymal-endodermal interaction system (eeis), a hanging drop culture in which an explant of neural fold from behind the prospective ear region of a triturus alpestris neurula together with a piece of ventrolateral pharynx endoderm is cultivated, the differentiation of a variety of neural crest-derived cells (nerve cells, pigment cells, cartilage cells, perichondrial cells, schwann cells) can be followed. while cartilage cells develop only in contact to pharynx endoderm, the differ ... | 1978 | 700284 |
| a proteoglycan with affinity for the vegetalizing factor: characterization by density gradient centrifugation. | a crude proteoglycan fraction isolated from chicken embryos has an affinity for the vegetalizing factor, which induces mesodermal and endodermal tissues in gastrula ectoderm of triturus alpestris. binding of the factor to the crude proteoglycan results in inactivation of the vegetalizing factor. the crude proteoglycan was centrifuged in cscl and cscl-urea density gradients. most of the inactivating material was recovered from the gradients in the high density proteoglycan fraction. part of the i ... | 1978 | 732367 |
| changes of nucleosome frequency in nucleolar and non-nucleolar chromatin as a function of transcription: an electron microscopic study. | the morphology of nucleolar and non-nucleolar (lampbrush chromosome loops) chromatin was studied in the electron microscope during states of reduced transcriptional activity in amphibian oocytes (xenopus laevis, triturus alpestris, t. cristatus). reduced transcriptional activity was observed in maturing stages of oocyte development and after treatment with an inhibitor, actinomycin d. strands of nucleolar chromatin appear smooth and thin, and contain only few, if any, nucleosomal particles in th ... | 1978 | 566162 |
| neural induction, a two-way process. | a quantitative analysis of triturus alpestris recombinates of newly invaginated "caudal" archenteron roof with either competent gastrula ectoderm or non-competent neurula ectoderm has demonstrated that neuralisation evoked by the underlying archenteron roof affects, in its turn, the regional differentiation of the latter. it does so by enhancing its notochordal differentiation; so, neural induction is clearly a two-way process. somite differentiation is not significantly different in the two ser ... | 1978 | 732368 |
| cell contacts between chorda-mesoderm and the overlaying neuroectoderm (presumptive central nervous system) during the period of primary embryonic induction in amphibians. | using transmission and scanning electron microscopy we were able to show that during primary embryonic induction in amphibians (triturus alpestris) the interspace between the inducing chorda-mesoderm and the reacting ectoderm (presumptive medullary plate) of mid-gastrula stages is traversed by cell projections starting from cells of both tissue layers. in addition intimate membrane contacts between the main bodies of the ectodermal and chorda-mesodermal cells could be observed. it could be ruled ... | 1979 | 478211 |
| change of the differentiation pattern of amphibian ectoderm after the increase of the initial cell mass. | early amphibian gastrula ectoderm (triturus alpestris) has been treated with vegetalizing factor. while normal sandwiches (animal caps of two eggs) differentiated mainly into endoderm derived tissues, giant-sandwiches (a combination of 8 animal caps) formed mesodermal and neural tissues in addition. the results support the interpretation that ectoderm will differentiate into endoderm derived tissues when all or nearly all cells are induced (presumably depending on certain threshold concentration ... | 1979 | 28304920 |
| endocrine-like cells in the lungs of the newt, triturus alpestris laur. | endocrine-like cells (elc) scattered in the basal part of the ciliated epithelium were identified in the lungs of the newt, triturus alpestris. these elc have a clear cytoplasm containing large amounts of secretory vesicles (69-180 nm in diameter), especially in their basal parts, but do not display formaldehyde-induced fluorescence. the elc may be associated with nerve fibres. | 1980 | 7407854 |
| scanning and transmission electron microscopic study of the lung of the newt, triturus alpestris laur. | the lungs of triturus alpestris laur. were investigated with the scanning and transmission electron microscopes. dimensions of the cell bodies of pneumocytes and ciliated cells, as well as the thickness of the air-blood barrier, were determined. the lungs of the newt form two simple sacs without septa. a ciliated epithelium containing goblet cells lines the pulmonary vein and partially the pulmonary artery. the remainder of the lung surface is covered internally by respiratory epithelium consist ... | 1980 | 7363303 |
| sarcomagenesis and myofibril maturation during limb regeneration and development of the newt, triturus alpestris and salamander, salamandra salamandra. | during limb regeneration of the salamander, salamandra salamandra, muscles dedifferentiate and then mesenchymal cells appear, which subsequently, differentiate into muscle. both in regenerates and in developing limbs of newts larvae mesenchymal cells begin to differentiate into myoblasts, which contain both thin (7 nm) and thick (14 nm) filaments, which are often associated with microtubules, developing a cytoskeletal network, which contribute directly to the shape of myoblasts and a linear alig ... | 1980 | 7193943 |
| a new type of cell in the pulmonary epithelium of the newt triturus alpestris laur. a scanning and transmission electron microscopic study. | single cells of a new type appear scattered among pneumocytes in the pulmonary epithelium. the surfaces of these cells communicate with the air space and display numerous finger-like microvilli. in comparison to pneumocytes, these cells have a more lucid cytoplasm and their apical parts contain large amounts of electron-lucent vesicles and electron-dense granules, which are probably released into the lumen of the lung. these secretory cells exhibit a yellow formaldehyde-induced fluorescence, whi ... | 1980 | 7437126 |
| projections of color coding retinal neurons in urodele amphibians. | optic fiber projection in the brain of salamandra salamandra was investigated by degeneration techniques. terminal fields are described in the thalamus and in the optic tectum. microelectrode recordings were performed from ganglion cells in the retina and from their terminals in the thalamus and tectum in salamandra and triturus alpestris. 'on' cells showed maximal sensitivity either in the blue or in the yellow spectral region; they project to the thalamus. color coding 'on-off' cells project t ... | 1981 | 7237102 |
| [histological and histochemical observations on the skin differentiation in metamorphotic and non-metamorphotic triturus alpestris apuanus (bonap) (amphibia urodela)]. | 1981 | 7201300 | |
| atypical mitochondria in the lung of newts, triturus alpestris, laur. | 1981 | 7310939 | |
| development of retinofugal neuropil areas in the brain of the alpine newt, triturus alpestris. | the development of the retinofugal projection areas of the brain has been studied in larvae of triturus alpestris by means of anterograde transported horseradish peroxidase. the optic tract establishes contacts with the optic tectum prior to the onset of robust terminal formation in the diencephalon. the tectum becomes covered by the retinofugal projection in a rostro-caudal direction. the basal optic neuropil develops synchronously with the oculomotor neurons. their dendrites extend into this n ... | 1981 | 7283179 |
| the electrical profile of the distal tubule in triturus kidney. | the transepithelial potential difference (vte) and transepithelial resistance (rte) were determined along the length of the distal tubule of the amphibian triturus alpestris. the site of impalements was determined at the end of each experiment by latex injection and microdissection. two segments, differing by their distribution at the surface of the kidney, by their respective diameters and by their electrical properties could be identified: the early distal tubule (edt) and the late distal tubu ... | 1982 | 7177780 |
| changes in the distribution of melanophores and xanthophores intriturus alpestris embryos during their transition from the uniform to banded pattern. | the change in distribution of melanophores from stage 28+ (uniform melanophore pattern) to stage 34 (banded melanophore pattern) and the participation of xanthophores in these changes has been investigated intriturus alpestris embryos by studying the social behaviour of single cells. while melanophores are clearly visible from outside the embryo at stage 28+, xanthophores cannot be recognized from the outside until after stage 34. in ultrathin sections of stage 34 embryos, xanthophores are obser ... | 1982 | 28305417 |
| formation of pigment cell patterns in triturus alpestris embryos. | 1982 | 7095277 | |
| different distribution of melanophores and xanthophores in early tailbud and larval stages intriturus alpestris. | the subepidermal distribution of xanthophores and melanophores is investigated in embryos oftriturus alpestris with a uniform (stage 28+) and a banded melanophore pattern (stage 35/36). in ultrathin head and trunk sections from stage 35/36 embryos which externally show longitudinal dorsal and lateral melanophore bands in the trunk and less compact continuations of the dorsal bands in the head, xanthophores were discovered in addition to melanophores. melanophores contain melanosomes while xantho ... | 1982 | 28305418 |
| neural induction in amphibians : transmission of a neuralizing factor. | the neural plates of very early neurula stages of triturus alpestris were removed, the material which is released from the extracellular space between mesoderm and neural plate to the medium in which the embryos were dissected was isolated and extracted with phenol. the protein isolated from the phenol layer showed neural inducting activity. proteoglycans isolated from the aqueous layer did not show such inducing activity. these results together with previously published experiments (wilhelm rou ... | 1983 | 28305334 |
| embryonic induction and cation concentrations in amphibian embryos. | explanted ectoderm from early gastrulae of triturus alpestris was treated with the na-k ionophore gramicidin (10(-9) to 10(-5) m) and the ca-ionophore a 23187 (10(-7) to 10(-5) m). the ectoderm developed almost exclusively to atypical epidermis as in the control explants. when the ectoderm was treated with ouabain (10(-4) m), intracellular na+ increased about 4.4-fold and k+ was reduced by half. mesenchyme cells in small number differentiated in about 40% of the ouabain-treated explants. the tim ... | 1985 | 2416476 |
| two thalamo-telencephalic pathways in a urodele, triturus alpestris. | ascending thalamo-telencephalic projection systems have been investigated in an urodele, triturus alpestris, using the horseradish peroxidase technique. two separate dorsal thalamic projections onto the telencephalon have been identified; one arises from the posterior dorsal thalamus and terminates in the ipsilateral striatum, the other originates from anterior dorsal thalamic cells and reaches the medial pallium and a part of the dorsal pallium bilaterally. both systems, which are spatially wel ... | 1986 | 3014400 |
| the molecular mechanism of neural induction: neural differentiation of triturus ectoderm exposed to hepes buffer. | ectoderm was isolated from early gastrula stages of triturus alpestris and cultured in salt solution buffered with either bicarbonate or hepes as the principal buffer substance. when bicarbonate was the principal buffer substance or when bicarbonate was omitted, the isolated ectoderm formed atypical epidermis. when hepes was added as a buffer substance, neural tissue was formed in a high percentage of cases. the differentiation of neural tissue depends on the ph of the hepes buffer. hepes in the ... | 1986 | 28305201 |
| vitamin a promotes dna synthesis and mitosis in blastemas of triturus alpestris. | vitamin a palmitate orally administered to young, post-metamorphic triturus alpestris (amphibia-urodela), for 4 and 7 days after bilateral forelimb amputation at the middle of the zeugopodium, enhanced the mean dna content of the blastema cells. moreover, the number of cells in mitosis was nearly twice as high in vitamin a treated animals than in control ones. | 1987 | 3690680 |
| putative neurotransmitters in the retinae of three urodele species (triturus alpestris, salamandra salamandra, pleurodeles waltli). | the immunocytochemical localization of several substances with putative neurotransmitter or modulator properties was investigated in the retinae of three urodele species. gamma-aminobutyric acid-like immunoreactive labelling appeared in different types of amacrine and horizontal cells. in addition, labelled fibres in the optic nerve were detected. it was not possible to determine whether these fibres were ganglion-cell axons or part of an efferent projection. endogenous serotonin was found in se ... | 1988 | 2898293 |
| intercalary regeneration in postmetamorphic forelimbs of triturus alpestris. | 1988 | 3412342 | |
| intercalary regeneration in the different hindlimb stages of triturus alpestris larvae. | 1988 | 3412341 | |
| influence of vitamin a on proximal and distal blastemata of triturus alpestris--a morphological and cytophotometrical study. | 1988 | 3412338 | |
| vitamin a induced bilateral asymmetries in triturus forelimb regenerates. | after amputation of both forelimb of young, postmetamorphic triturus alpestris through the middle of the zeugopod, the left and right regenerates grew asynchronously. as a result of oral administration of vitamin a palmitate (250 iu/gbw/day), from the 4th to the 13th dpa, the growth rate of the right regenerates was relatively higher than that of the left ones. moreover, the percentage of skeletal abnormalities as well as proximodistal duplications (proximalizations), induced by vitamin a, was n ... | 1988 | 3401522 |
| influence of vitamin a palmitate on the growth of regenerating triturus alpestris forelimbs. | the objective of this investigation was to analyse the effects of vitamin a palmitate orally administered to young postmetamorphic triturus alpestris on the growth of regenerates. vitamin a was administered for 4, 7, 11 and 14 days after amputation at the middle of the right zeugopod. growth of regenerates was evaluated on the basis of external size measurements and blastema cell proliferation. calculation of the percentages of cells in each cell-cycle phase and estimation of mitotic indices dur ... | 1988 | 3196784 |
| the monoaminergic system in the diencephalon of the newt tadpole, triturus alpestris (mert). a histofluorescence study. | the distribution of monoamines in the brain of triturus alpestris tadpoles was investigated with the falck-hillarp histofluorescence method. this study concerns especially the diencephalon where is observed the major part of the monoaminergic (ma) neurons. ma fiber tracts are found in the striatum, the septal nucleus and the medial and lateral forebrain bundles of the telencephalon. in the anterior diencephalon cerebrospinal fluid (csf)--contacting catecholaminergic cells are localized within th ... | 1988 | 3183361 |
| identification of pigment cells during early amphibian development (triturus alpestris, ambystoma mexicanum). | the purpose of the present investigation was to provide and apply a methodological manual with which the distribution, patterning and relationship of melanophores and xanthophores can be analyzed during early amphibian development. for demonstration of the methods, which include ultrastructural, histochemical and biochemical approaches, triturus alpestris and ambystoma mexicanum (axolotl) embryos are used. these two species differ conspicuously in their larval pigment patterns, showing alternati ... | 1988 | 3141059 |
| development of retinofugal neuropil areas in the brain of the alpine newt, triturus alpestris. ii. topographic organization and formation of projections. | the development of retinal projections and the formation of their retinotopic organization were studied by means of anterograde transport of horseradish peroxidase in the newt, triturus alpestris. all tracts found in the adult on the contralateral brain side are established during embryonic stages. at this stage a few uncrossed fibers are also detectable. retinal fibers project first to the contralateral optic tectum. these are followed by contralateral projections to the thalamic recipient area ... | 1988 | 2833132 |
| activation of masked neural determinants in amphibian eggs and embryos and their release from the inducing tissue. | the neural-archencephalic (forehead) inducing activity of the microsomes and the high speed supernatant from xenopus laevis ovaries and eggs was tested on gastrula ectoderm of triturus alpestris. both fractions have a very small inducing activity which increases considerably after autolysis or treatment with dissociating agents. a comparison with the inducing activity of the high speed supernatant from gastrulae suggests that neural inducing factors are synthesized in the ovary, stored in a mask ... | 1989 | 2766041 |
| characterization of heterochromatic regions in two triturus alpestris subspecies (urodela: salamandridae). | the fluorescence analysis carried out in triturus alpestris alpestris and triturus alpestris cyreni subspecies has revealed differences related to the content and distribution of at-rich, gc-rich and non-fluorescent heterochromatic bands. these results provide new evidence on the chromosome differentiation undergone in their phylogenetic splitting. | 1989 | 2767986 |
| fidelity to the breeding site in the alpine newt triturus alpestris. | in a context of several closed breeding sites (archipelago model), the great majority of alpine newts are sedentary, visiting the same site during two successive years. a homing experiment offered the animals a choice between two breeding sites, one from which they came and the other which was inhabited by another population. this experiment demonstrates the fidelity of a great majority of newts for their site of origin. fidelity was stronger when sites were distant (150 m) than when nearer (25 ... | 1989 | 24895901 |
| thermal behaviour of a4 lactate dehydrogenase purified from the heterothermic and sympatric vertebrate species brook lamprey (lampetra planeri), tench (tenca tenca), smooth (triturus vulgaris) and alpine newt (triturus alpestris). | 1. the a4 lactate dehydrogenase isozyme was purified to homogeneity from the tissues of brook lamprey (lampetra planeri), tench (tenca tenca), smooth newt (triturus vulgaris) and alpine newt (t. alpestris). 2. these four species share their geographical distribution in the same freshwater habitats, often live together in the same station and two of them are congeneric. steady-state kinetic investigations have shown that: 3. km (apparent) for pyruvate vs. temperature and (apparent) product ki (py ... | 1989 | 2620488 |
| effect of vitamin a on wound epidermis during forelimb regeneration in adult newts. | the effects of vitamin a on blastemal epidermis were studied during the early postamputational period of forelimb regeneration in triturus alpestris. vitamin a was administered through oral intubation at a dose of 250 iu per gram of body weight per day. the results were evaluated by morphometry, histology, and autoradiography. after 7, 11 and 14 days of treatment, several alterations were observed in the wound epidermis: a) reversal of keratinization; fewer keratinized cells were counted in sect ... | 1990 | 1705139 |
| telencephalic structures are involved in learning and memory in the newt triturus alpestris. | 1990 | 2377236 | |
| isolation of a vegetalizing inducing factor after extraction with acid ethanol. concentration-dependent inducing capacity of the factor. | a vegetalizing factor has been isolated from chicken embryos by an improved method. the factor is extracted with acid/ethanol and finally purified by four consecutive steps of reversed phase hplc. the molecular mass is about 25 kda. the factor dissociates after reduction with dithiothreitol into two subunits of about 13 kda. the factor was tested on triturus alpestris by the implantation method, and on isolated ectoderm of xenopus laevis in solution. the factor induces as the crude fractions all ... | 1990 | 2090330 |