Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| involvement of endogenous prolactin in the expression of courtship behavior in the newt, cynops pyrrhogaster. | in order to ascertain the involvement of endogenous prolactin (prl) in the expression of courtship behavior by the male newt, cynops pyrrhogaster, antiserum against homologous prl was administered to male newts, which had been exhibiting courtship behavior in the field and had been taken to the laboratory. the effect of the antiserum on the preference of terrestrial over aquatic habitats also was investigated. within 24 hr of the first injection of antiserum, both incidence and frequency of cour ... | 1996 | 8998963 |
| cytopathologic observations of the lung of adult newts (cynops pyrrhogaster) on-board the space shuttle, columbia, during the second international microgravity laboratory experiments. | four adult female japanese newts, cynops pyrrhogaster, were carried for 15 days aboard the orbiting space shuttle, columbia, in july of 1994, as part of the second international microgravity laboratory, iml-2 aquatic animal experiments. these previously fertilized newts, after stimulation with chorionic gonadotropin by a spaceflight adapted injection procedure, deposited numerous eggs for study of early development during weightlessness. the primitive saccular lungs of the two newts which surviv ... | 1995 | 11536733 |
| head and trunk-tail organizing effects of the gastrula ectoderm of cynops pyrrhogaster after treatment with activin a. | differentiation tendency and the inducing ability of the presumptive ectoderm of newt early gastrulae were examined after treatment with activin a at a high concentration (100 ng/ml). the activin-treated ectoderm differentiated preferentially into yolk-rich endodermal cells. combination explants consisting of three pieces of activin-treated ectoderm formed neural tissues and axial mesoderm along with endodermal cells. however, the neural tissue was poorly organized and never showed any central n ... | 1995 | 28305862 |
| non-invasive assessment of otolith formation during development of the japanese red-bellied newt, cynops pyrrhogaster. | pre-mated adult female newts and embryos have been flown on the international microgravity laboratory-2 (iml-2) space shuttle flight in 1994 (wiederhold et al., 1992b). with the specimens available from this flight, the calcification of otoliths, ulna, radius and backbone of the flown larvae and adult newts were analyzed. the experiments presented here studied the development of the otoliths on the ground. otoliths of living newts, from embryo to adult, were observed in situ with the application ... | 1995 | 8575997 |
| proliferation of newt spermatogonia by mammalian fsh via sertoli cells in vitro. | our previous studies showed that mammalian follicle-stimulating hormone (fsh) stimulated the proliferation and differentiation of secondary spermatogonia into primary spermatocytes in organ culture of testes fragments from cynops pyrrhogaster. to elucidate how fsh stimulates spermatogonial proliferation, we studied the interaction of spermatogonia with somatic cells in the presence or absence of fsh in cultures of aggregated cells derived from fractionated cell populations. when spermatogonia or ... | 1995 | 7673874 |
| atomic force microscope observations of otoconia in the newt. | calcitic and aragonitic otoconia from the japanese red-bellied newt, cynops pyrrhogaster, were examined using an atomic force microscope. the surface structure of both otoconial polymorphs consisted of arrays of elements approximately 50 nm in diameter. elements were generally round and were separated by shallow depressions of no more than 20 nm. the elements are suggested to be single crystals of calcium carbonate. the relationship of these observations to theories of otoconial genesis is discu ... | 1995 | 7559167 |
| calcium-containing, smooth-surfaced endoplasmic reticulum and vacuoles in cells of the blastopore-forming region during gastrulation of the newt, cynops pyrrhogaster. | ultrastructural changes in cells of the blastopore-forming region (bfr) were examined during gastrulation of the newt, cynops pyrrhogaster. smooth-surfaced endoplasmic reticulum (ser), tubular in shape and with two types of vacuole, empty vacuoles and multilamellar vacuoles, appeared in cells of the bfr at the beginning of formation of the blastopore. the extent of the tubular ser increased during formation of the blastopore. with the deepening of the blastoporal groove, the tubular ser and mult ... | 1995 | 7645763 |
| the morphogenic features of otoconia during larval development of cynops pyrrhogaster, the japanese red-bellied newt. | otoconia are calcified protein matrices within the gravity-sensing organs of the vertebrate vestibular system. mammalian otoconia are barrel-shaped with triplanar facets at each end. reptilian otoconia are commonly prismatic or fusiform in shape. amphibians have all three otoconial morphologies, barrel-shaped otoconia within the utricle, with prismatic and fusiform otoconia in the saccule. scanning electron microscopy revealed a sequential appearance of all three otoconial morphologies during la ... | 1995 | 7642456 |
| development of the otolith organs and semicircular canals in the japanese red-bellied newt, cynops pyrrhogaster. | the sequence in which the otoliths and semicircular canals and their associated sensory epithelia appear and develop in the newt are described. three-dimensional reconstruction of serial sections through the otic vesicle of newt embryos from stages 31 through 58 demonstrate the first appearance, relative position and growth of the otoliths. a single otolith is first seen in stage 33 embryos (approximately 9 days old); this splits into separate utricular and saccular otoliths at stage 40 (13 days ... | 1995 | 7642454 |
| development and application of a homologous radioimmunoassay for xenopus prolactin. | a specific and sensitive homologous radioimmunoassay (ria) for xenopus prolactin (xprl) was developed. prl isolated from x. laevis pituitary glands was used for generating antiserum in a rabbit, for radioligand and for the standard. pituitary homogenates and plasma from adult xenopus produced displacement curves parallel to the xprl standard. plasma from hypophysectomized xenopus showed negligible cross-reactivity. purified prls from other amphibian species such as the bullfrog (rana catesbeiana ... | 1995 | 7657154 |
| promotion of differentiation of newt primary spermatocytes into spermatids by mammalian fsh via sertoli cells. | our previous studies showed that mammalian follicle-stimulating hormone (fsh) promoted the differentiation of primary spermatocytes into elongated spermatids in organ culture of testes fragments from cynops pyrrhogaster. to elucidate the mechanism of fsh action, in this study the testes in the primary spermatocyte stage were dissociated and fractionated into germ and somatic cells, the latter comprising more than 80% sertoli cells. radioreceptor assays showed that fsh bound to somatic cells, ver ... | 1995 | 7673875 |
| sodefrin: a female-attracting peptide pheromone in newt cloacal glands. | a decapeptide called sodefrin was isolated from the abdominal gland of the cloaca of the male red-bellied newt, cynops pyrrhogaster. the native peptide, as well as the synthetic one, had a female-attracting activity. sodefrin was found in the apical portion of the epithelial cells of the abdominal gland. sodefrin is apparently species specific because it did not attract females of cynops ensicauda. this is the first amphibian pheromone to be identified and the first peptide pheromone identified ... | 1995 | 7886452 |
| comparison of mauthner cell size in sexually developed and undeveloped male red-bellied newts. | differences in mauthner (m) cell size were examined in sexually developed and undeveloped male red-bellied newts, cynops pyrrhogaster. the mean areas of nuclei and cell bodies of m cells and mean maximum and minimum diameters of the cell bodies in the sexually developed males were significantly larger than those in the sexually undeveloped ones. in the hypophysectomized male newts, all these parameters were not significantly different from those in the sexually undeveloped ones. these values wer ... | 1995 | 8586962 |
| [new sex pheromone isolated from the abdominal glands of male newt, cynops pyrrhogaster]. | sodefrin, a novel decapeptide which attracts female newts, cynops pyrrhogaster was isolated from the abdominal gland of the male of the same species. synthetic sodefrin was tested for its activity with sexually active females and males and sexually inert females. it attracted only sexually active females. the effect of sodefrin was blocked by a bilateral nostril plugging with cotton balls soaked in melted vaseline. immunoelectronmicroscopic study using antiserum against sodefrin revealed that so ... | 1995 | 8763038 |
| hormonal control of response to and secretion of sex attractants in japanese newts. | hormonal control of sexual chemoattraction in the newt, cynops pyrrhogaster, was investigated by a water preference test. sexually inert newts injected with prolactin (prl) and human chorionic gonadotropin (hcg) in combination preferred the water in which newts of the opposite sex had been kept, whereas saline-injected specimens did not. this indicates that prl and hcg enhance the response of the newts to attractant(s) secreted by the opposite sex. the water in which prl plus hcg-treated newts h ... | 1994 | 8190778 |
| ultrastructure of the olfactory organ of the newt, cynops pyrrhogaster. | the ultrastructure of the nasal sacs of the japanese newt, cynops pyrrhogaster, was studied by scanning and transmission electron microscopy. the paired nasal sacs of the newt are dorsoventrally flattened with a lateral nasal sinus off the main cavity of each sac. throughout each sac is a series of ridges and grooves. in the main cavity, sensory epithelium with ciliated and microvillous receptor cells lines the grooves, and a thin, ciliated non-sensory epithelium lines the ridges. secretory glan ... | 1994 | 8059972 |
| initiation and stimulation of spermatogenesis in vitro by mammalian follicle-stimulating hormone in the japanese newt, cynops pyrrhogaster. | in order to elucidate the molecular mechanisms by which spermatogenesis is regulated, especially the roles of hormones and somatic cells in the initiation and promotion of spermatogenesis, we developed an organ culture system with a chemically defined medium. when newt testes fragments rich in secondary spermatogonia were cultured in control medium for three weeks, most of the testicular cysts still remained as secondary spermatogonia. on the other hand, in the medium supplemented with follicle- ... | 1994 | 7981029 |
| mammalian follicle-stimulating hormone stimulates dna synthesis in secondary spermatogonia and sertoli cells in organ culture of testes fragments from the newt, cynops pyrrhogaster. | we previously showed in organ culture of testes fragments from cynops pyrrhogaster that mammalian follicle-stimulating hormone (fsh) stimulates secondary spermatogonia to differentiate into primary spermatocytes. in this report, we demonstrate in organ culture that fsh stimulates dna synthesis in secondary spermatogonia and sertoli cells: the numbers of secondary spermatogonia and sertoli cells incorporating 5-bromo-2'-deoxyuridine (brdu) throughout the culture period in the presence of fsh were ... | 1994 | 7881917 |
| formation of otoconia in the japanese red-bellied newt, cynops pyrrhogaster. | pre-mated adult female newts and fertilized eggs will be flown on the international microgravity laboratory-2 flight, in 1994. one objective of the flight will be to observe the influence of microgravity on the development of the gravity-sensing organs in the inner ear. these organs contain sensory hair cells covered by a layer of dense stones (otoconia). gravity and linear acceleration exert forces on these masses, leading to excitation of the nerve fibers innervating the hair cells. if the pro ... | 1994 | 11537935 |
| neuroepithelial endocrine and nervous system in the respiratory tract of cynops pyrrhogaster with special reference to the distribution of nitric oxide synthase and serotonin. | the respiratory tract of urodeles harbours an intramural nerve network comprising an innervated system of neuroepithelial endocrine (nee) cells. however, striking differences have been noted between phylogenetically closely related species. zamboni- or formaldehyde-fixed whole-mount preparations and sections of the saclike lungs of a japanese salamander, cynops salamander, cynops pyrrhogaster, have been investigated for the immunocytochemical detection of nitric oxide synthase (nos), serotonin ( ... | 1994 | 7529073 |
| the egg nucleus regulates the behavior of sperm nuclei as well as cycling of mpf in physiologically polyspermic newt eggs. | the possible role of the egg nucleus in regulating the behavior of sperm nuclei and the cycling of maturation-promoting factor (mpf) was investigated in the physiologically polyspermic eggs of the newt cynops pyrrhogaster. many sperm entered all areas of the egg, but only one sperm pronucleus, the principal sperm pronucleus, moved to the center of the animal hemisphere to form a zygote nucleus with the egg pronucleus. all sperm and egg pronuclei synthesized dna, but the zygote nucleus completed ... | 1993 | 8224532 |
| motion sickness in amphibians. | we explored the question of whether amphibians get motion sickness by exposing anurans (frogs) and urodeles (salamanders) to the provocative stimulus of parabolic aircraft flight. animals were fed before flight, and the presence of vomitus in their containers after flight was used to indicate motion-induced emesis. none of the species that we studied vomited during the 8 to 10 parabolas of each flight. however, at least one specimen from each of the anuran species rana rugosa, rana nigromaculata ... | 1993 | 8216158 |
| hormonal induction of male courtship behavior in the japanese newt, cynops pyrrhogaster. | in the breeding season, the sexually mature male newt, cynops pyrrhogaster, vibrates the tail in front of the female at an early stage of courtship. effects of prolactin (prl), gonadotropin (gth), and sex steroids on this behavior were investigated in the male paired with the female receiving prl and gth. the behavior was elicited in the sexually inert male by injections of prl of bovine, ovine, or bullfrog origin and human chorionic gonadotropin or bullfrog lh and fsh in combination. the effect ... | 1993 | 8294119 |
| [immunocytochemical studies on the pancreatic endocrine cells in the japanese newt (cynopus pyrrhogaster)]. | pancreatic endocrine cells were examined by light and electron microscopic immunocytochemistry to discuss the co-localization of peptides in one cell type. a cells were irregular in shape with an occasional long cytoplasmic process, and contained glucagon-immunoreactive granules with various contours. these granules were 160-300nm in diameter with various density, and also immunoreactive to anti-human pancreatic polypeptide (pp) serum. a part of them were further immunoreactive to anti-somatosta ... | 1992 | 1360408 |
| presence of d-aspartate oxidase and free d-aspartate in amphibian (xenopus laevis, cynops pyrrhogaster) tissues. | 1. this paper is the first report on the presence of d-aspartate oxidase activity and free d-aspartate in the amphibian tissues. 2. the presence of d-aspartate oxidase activity in tissues of clawed toad (xenopus laevis) and japanese newt (cynops pyrrhogaster) was demonstrated by requirements for enzyme activity, selective inhibition with meso-tartrate and substrate specificity. 3. in each animal, the highest activity was found in kidney, followed by liver and brain, and no gender difference in t ... | 1992 | 1424565 |
| comparative study of sexual dimorphism of the innominate bone in rodents and amphibians. | sexual dimorphism in the shape of the innominate bone was demonstrated in the rat, mouse, chinese hamster (cricetulus griseus), frog (ranna nigromaculata), and newt (cynops pyrrhogaster) with a computer-assisted morphometric technique. in the rat, mouse, and hamster, ratios of ischium and pubis widths to the innominate bone length (inl) were larger in the males than in the females; however, the ratio of pubis length to inl was larger in the females than in the males. in the frog, the ratio of di ... | 1992 | 1443668 |
| epibolic extension of the presumptive ectodermal layer of embryos of the newt cynops pyrrhogaster before and during gastrulation. | epibolic extension of the presumptive ectodermal layer (pel) was investigated in embryos of the newt cynops pyrrhogaster before and during gastrulation. the pel was composed of only one layer of columnar cells at all stages examined. the cells of the pel became elongated from the blastula to the early gastrula stage. they were most elongated at the early gastrula stage and then shortened during gastrulation. present observations suggest that changes in cell shape of the pel play an important rol ... | 1992 | 1402739 |
| expression and distribution of regeneration-responsive molecule during normal development of the newt, cynops pyrrhogaster. | we have investigated the expression and distribution of the regeneration-responsive molecule, 2ni-36, the loss of which is responsible for initiation of dedifferentiation of dorsal marginal iris pigmented epithelial cells to regenerate a lens. in the process of the normal development of the newt, the expression of 2ni-36 could not be detected in embryos at the early developmental stages, i.e., cleavages, gastrulation and neurulation, nor through later developmental stages to tail-bud, even thoug ... | 1992 | 1445784 |
| an immunohistochemical study of regenerating newt retinas. | light-microscopical examination was carried out to investigate the emergence and development of several classes of immunoreactive cells in regenerating retinas of the adult newt (triturus pyrrhogaster) after total retinal ablation. immunoreactive proliferating cell nuclear antigen (ir-pcna, a marker for replicating cells) was present in nuclei of all neuroblasts in the early mono-layered to several-layered stages (15-20 days after retinal ablation; days 15-20), but was lost progressively in an i ... | 1992 | 1356660 |
| appearance and maturation of voltage-dependent conductances in solitary spiking cells during retinal regeneration in the adult newt. | electrical membrane properties of solitary spiking cells during newt (cynops pyrrhogaster) retinal regeneration were studied with whole-cell patch-clamp methods in comparison with those in the normal retina. the membrane currents of normal spiking cells consisted of 5 components: inward na+ and ca++ currents and 3 outward k+ currents of tetraethylammonium (tea)-sensitive, 4-aminopyridine (4-ap)-sensitive, and ca(++)-activated varieties. the resting potential was about -40 mv. the activation volt ... | 1992 | 1625217 |
| reduction of papilloma size by ultraviolet irradiation in the japanese newt, cynops pyrrhogaster. | experiments were conducted on 44 captive japanese newts (cynops pyrrhogaster) to test the hypothesis that ultraviolet (uv) irradiation might inhibit growth or induce regression of spontaneous skin papillomas of probable viral origin. an empirically derived exposure to uv irradiation (42 microw per cm2 per day) induced reduction of papilloma size which began approximately 4 weeks after irradiation was initiated. this regression included histological evidence of tissue vacuolization and cellular n ... | 1992 | 1556253 |
| characterization of a tandemly repeated dna sequence family originally derived by retroposition of trna(glu) in the newt. | a previous report from this laboratory showed that in vitro transcription of total genomic dna of the newt cynopus pyrrhogaster resulted in a discrete sized 8 s rna, which represented highly repetitive and transcribable sequences with a glutamic acid trna-like structure in the newt genome. we isolated four independent clones from a newt genomic library and determined the complete sequences of three 2000 to 2400 base-pair psti fragments spanning the 8 s rna gene. the glutamic acid trna-related se ... | 1991 | 1660072 |
| involvement of prolactin in the regulation of plasma calcium levels in the newt, cynops pyrrhogaster. | in the newt, cynops pyrrhogaster, parathyroidectomy (ptx) brought about a marked decrease in the concentration of plasma calcium. the animals recovered from the hypocalcemia by 15 days after the operation if the pituitary gland was left intact. after ptx, no significant changes in the plasma sodium concentration were observed. experiments were then conducted to obtain direct evidence that endogenous prolactin (prl) is involved in this recovery process. recovery of the calcium level after ptx was ... | 1991 | 2055443 |
| the occurrence of melanosomes in the newt glomus cell. | combined light and electron microscopic observations of the carotid labyrinth of the newt, cynops pyrrhogaster, revealed the occurrence of glomus cells with melanosomes (mg cells), a finding so far unreported in the amphibian carotid labyrinth. these melanosomes, which derived from melanophores, were electron-dense and usually oval (250-700 nm in diameter). they occurred in groups enclosed by a limiting membrane, and the diameter of clusters was approximately 1.5 microns. these clusters were sur ... | 1991 | 2039662 |
| magnetic shielding induces early developmental abnormalities in the newt, cynops pyrrhogaster. | developing larvae of the japanese newt, cynops pyrrhogaster, were subjected for 5 days to a shielded environment in which the static magnetic field was about 10,000 times weaker (5 nt) than the geomagnetic norm, which ranges between 30 and 60 microt at the earth's surface. larvae from non-cleavage to neurula stages were exposed under shielded or normal (control) conditions and then examined for evidence of developmental abnormalities either 1 day or 20 days after treatment. the magnetic shieldin ... | 1991 | 1930306 |
| liver ultrastructure and a new cell type in the japanese newt, cynops pyrrhogaster. | the liver of the japanese newt, cynops pyrrhogaster, has been investigated using light, scanning, and transmission electron microscopy. hepatic parenchyma was composed of clusters and cords or tubules of polyhedral cells separated by a sinusoidal net. hepatocytes had spherical, euchromatic nuclei with one or more nucleoli and stacked mitochondria with sparse cristae and dense bodies. rough endoplasmic reticula formed peribiliary stacks and diffusely scattered vesicles and tubules. smooth endopla ... | 1991 | 1815727 |
| homologous radioimmunoassay for bullfrog growth hormone. | antiserum against bullfrog growth hormone (fgh) was produced by immunizing rabbits with the highly purified fgh obtained from adenohypophyses of adult bullfrogs. histological studies on bullfrog adenohypophyses revealed that the cells that immunologically reacted with the antiserum against fgh corresponded to the ones positively stained with the antiserum against rat gh. the antiserum together with fgh and 125i-fgh was employed to develop a radioimmunoassay (ria) for fgh. several dilutions of pl ... | 1991 | 1874383 |
| amphibian prolactins: activity in the eft skin transepithelial potential bioassay. | the effects of purified prolactins isolated from frogs (fprl; rana catesbeiana) and newts (nprl; cynops pyrrhogaster) were compared with those of ovine prolactin (oprl) and thyrotropin releasing hormone (trh) in the eft (notophthalmus viridescens) skin transepithelial potential (tep) bioassay. at total doses as low as 0.4 micrograms/animal, both fprl and nprl were as effective as oprl in reducing eft skin tep. by contrast, trh at total doses as high as 400 micrograms/animal was ineffective in al ... | 1991 | 1908395 |
| purification and properties of newt prolactin. | a highly purified prolactin (prl) was obtained from pituitary glands of newts, cynops pyrrhogaster, by extraction of acetone-dried powder with acid acetone and high-performance liquid chromatography (hplc) on mono-q (anion exchange), superose-12 (gel filtration), and tsk-gel ods-120t (reverse-phase) columns with a yield of 4.5 mg per 325 mg of protein starting material. purification was monitored by sds-polyacrylamide gel electrophoresis (page) and western blotting analysis employing antiserum a ... | 1990 | 2295424 |
| how is the flagellar length of mature sperm determined? ii. comparison of tubulin synthesis in spermatids between newt and xenopus in vitro. | in order to elucidate mechanisms that control flagellar length of mature sperm, we studied in synchronous cell suspension cultures flagellar growth, tubulin pool, and tubulin synthesis in round spermatids of xenopus laevis and the newt cynops pyrrhogaster. the average final length of flagella in xenopus round spermatids was 35 mum, almost the same length as that in mature sperm, whereas in the newt round spermatids, the length was 210 mum, almost half that of mature sperm. kinetics of flagellar ... | 1990 | 2298244 |
| gastric leiomyomas in the japanese newt, cynops pyrrhogaster; ultrastructural observations. | nineteen of 700 outwardly healthy captive adult japanese newts, cynops pyrrhogaster, had nodular neoplasms protruding on the gastric serosal surface. these tumours were characterized as sharply circumscribed leiomyomas of the muscularis externa with occasional submucosal involvement. ultrastructural analysis of tumour myocytes revealed irregular-shaped, well-differentiated cells with cytoplasmic processes, and reduced quantities of intracellular myofibrils. they were surrounded by enlarged inter ... | 1990 | 2312798 |
| comparative studies on the vascular organization of carotid labyrinths of anurans and caudates. | the three-dimensional structures of the carotid labyrinth in five species of anurans representing four families (rana nigromaculata, rana catesbeiana, bufo japonicus, hyla arborea, and xenopus laevis), and three species of caudates representing three families (cynops pyrrhogaster, hynobius nebulosus, ambystoma mexicanum) were compared using vascular corrosion castings and scanning electron microscopy (sem). anuran carotid labyrinths are spherical in shape and are classified into two groups accor ... | 1990 | 2338718 |
| development and application of homologous radioimmunoassay for newt prolactin. | a specific and sensitive homologous radioimmunoassay (ria) for newt (cynops pyrrhogaster) prolactin (prl) was developed. prl isolated from newt pituitary glands was used for generating antiserum in a rabbit, for radioiodination, and for the standard. several dilutions of plasma and pituitary homogenate of newts yielded dose-response curves which were parallel to the standard curve. plasma from hypophysectomized newts showed the least amount of cross-reaction. pituitary homogenates of other speci ... | 1990 | 2354781 |
| cleavage plane determination in amphibian eggs. | in the present study using eggs of cynops pyrrhogaster and xenopus laevis, we examined (1) structural changes in the cytoplasm before the appearance of the cleavage furrow using a cytochemical method, (2) the time of cleavage plane determination depending on the mitotic apparatus (ma), by changing the shape of the eggs, and (3) the time of arrival of the "cleavage stimulus" at the cortex, by injecting colchicine solution or removing cytoplasm. results were as follows: (1) in amphibian eggs the d ... | 1990 | 2356982 |
| control of sperm nuclear behavior in physiologically polyspermic newt eggs: possible involvement of mpf. | we have studied the mechanism controlling the behavior of accessory sperm nuclei in physiologically polyspermic eggs of the newt, cynops pyrrhogaster. our approach was to identify cytoplasmic components which would prevent the usual degeneration of accessory sperm nuclei. injection of cytoplasm from unfertilized eggs, but not fertilized ones, induced multipolar cleavage in polyspermically fertilized eggs as well as centrosome separation and formation of extra bipolar spindles in accessory sperm ... | 1990 | 2257969 |
| differentiation of the brain stem reticular formation in the triturus, triturus pyrrhogaster. | the brain stem of the triturus was observed to be initially composed exclusively of the mantle layer. a few days before hatching, a narrow marginal layer differentiated peripherally. at the time of hatching, the marginal layer was clearly visible throughout the brain stem, except for in a medial region of the optic tectum. approximately one week after hatching, a few cells migrated into the marginal layer, and almost simultaneously, a few fibers in that layer were myelinated. cells migrating int ... | 1990 | 2216305 |
| development of cell surface activity and cell surface adhesiveness in early embryos of the newt, cynops pyrrhogaster. | the development of cell surface activity and adhesiveness was examined in relation to cleavage number in early embryos of the newt, cynops pyrrhogaster. both large hyaline bleb formation and surface adhesiveness to substratum were manifested in presumptive ectodermal cells isolated from embryos after the eleventh cleavage (mid-blastula stage). scanning electron microscopy of the inner surface of the blastocoelic wall (presumptive ectodermal cell layer) revealed the formation of large blebs after ... | 1990 | 2350730 |
| observations on cardiac ultrastructure of the adult japanese newt, cynops pyrrhogaster. | investigation of atrial and ventricular cardiac ultrastructure by transmission and scanning electron microscopy of the adult japanese newt, cynops pyrrhogaster, has revealed some unique cell types and features in this amphibian. typical urodelan-type thin trabeculae composed of myocytes with conventional architecture of loosely scattered myofibrils were observed. scarce granules of variable size and density were seen in atrial myocytes, and some purkinje-like fibers were observed. unique structu ... | 1990 | 2311100 |
| ultrastructural characterization of the spontaneous papilloma of japanese newts. | the spontaneous epithelioma of the japanese newt, cynops pyrrhogaster, is a useful animal model for study of development and regression of papillomata of suspected viral origin. therefore, ultrastructural studies of this cutaneous tumor were undertaken in order to characterize this model further. the ultrastructure of normal cynops pyrrhogaster epidermis resembled teleost more than anuran epidermis. surface cells of the bilayered stratum corneum were covered by micro-ridges and contained promine ... | 1989 | 2804952 |
| electrophysiological properties of three types of granulocytes in circulating blood of the newt. | 1. the electrophysiological properties of three subtypes of granulocytes obtained from the circulating blood of the newt, triturus pyrrhogaster, were studied using the whole-cell variation of the patch-electrode voltage-clamp technique. 2. neutrophils were identified by their multilobulated nucleus in the cytoplasm. basophils and eosinophils, having characteristic granular structures in their cells, could definitely be distinguished from other leucocytes. the reliability of cellular identificati ... | 1989 | 2484207 |
| developmental physiology of cardiac contraction in the japanese newt in vivo and in vitro. | development and differentiation of whole hearts of larvae of an experimental amphibian species, the japanese newt (cynops pyrrhogaster), were studied in vitro and in vivo with particular reference to cardiac contraction, its temperature sensitivity and morphology. hearts cultured in the solid or flat state in plastic flasks for 27 days developed from stage 35 to stage 55 and corresponded closely to in vivo developing hearts with respect to morphologic criteria and temperature sensitivity of card ... | 1989 | 2795664 |
| development of the heartbeat during normal ontogeny and during long-term organ culture of hearts of the newt, cynops pyrrhogaster. | development of cardiac contraction was investigated in the newt, cynops pyrrhogaster, during normal development and in hearts maintained in long-term organ culture. in the embryos the heart began beating as early as stage 33. the heart rate increased up to stage 52 and then gradually decreased to the adult rate by stage 60. the heart rate showed a logarithmic temperature dependence. in organ-cultured hearts the pattern of heart rate depended on the stage at which the heart was explanted; culture ... | 1989 | 2766048 |
| effects of salts in promoting the adhesion of amphibian gastrula cells. | presumptive ectodermal and endodermal cells were isolated from the gastrula of the newt cynops pyrrhogaster, and the effects of salts on embryonic cell adhesion were examined. when the concentrations of nacl, kcl, mgso4 and ca (no3)2 in the culture medium were increased individually, they all effectively promoted ectodermal cell adhesion. mgso4 and ca(no3)2 promoted endodermal cell adhesion, but nacl and kcl did not. the culture medium containing increased nacl (90 mm) nonspecifically promoted e ... | 1989 | 2723609 |
| amphibian (urodele) myotomes display transitory anterior/posterior and medial/lateral differentiation patterns. | myotome differentiation during mexican axolotl (ambystoma mexicanum) somitogenesis was analyzed by employing anti-actin and anti-myosin monoclonal antibodies as molecular probes. myotome differentiation occurs after segmentation and proceeds in the cranial-to-caudal direction along the somite file. within individual somites myotome differentiation displays distinct polarities. examination of the somite file at the tailbud stage revealed that soon after segmentation, actin/myosin accumulate predo ... | 1989 | 2647546 |
| how is the flagellar length of mature sperm determined? i. comparison of flagellar growth in spermatids between newt and xenopus in vitro. | the kinetics of flagellar growth in round spermatids were compared between xenopus laevis and cynops pyrrhogaster in vitro, the latter of which has about 13 times longer flagella in mature sperm than the former. in both species, more than 90% of the spermatids derived from marked primary spermatocytes grew flagella. in xenopus the average flagellar length increased to 28 microns by the 6th day and then stopped growth, while in the newt, flagellar growth did not stop until reaching 107 microns in ... | 1988 | 3371423 |
| factors related to the initiation of cell migration along the inner surface of the blastocoelic wall during amphibian gastrulation. | changes in the quantity of extracellular matrix on the inner surface of the blastocoelic wall (bw) and the adhesiveness of cells to fibronectin were examined in relation to the timing of initiation of cell migration along the bw during gastrulation of the newt, cynops pyrrhogaster. extracellular matrix fibrils were already abundantly present all over the inner surface of the bw prior to the beginning of cell migration. on the other hand, the adhesiveness of cells to fibronectin rapidly increased ... | 1988 | 3409322 |
| formation of germ layers and roles of the dorsal lip of the blastopore in normally developing embryos of the newt cynops pyrrhogaster. | three-dimensional relationships between tissues during the formation of germ layers were studied in sections of normally developing embryos of the newt, cynops pyrrhogaster. in gastrulae, the inner postinvolution layer was not in direct contact with the outer preinvolution layer as a result of the presence of an intervening layer of cells. only after the formation of the yolk plug, a narrow strip of primitive notochord, which consisted of columnar cells, established a close contact with the cent ... | 1988 | 3404106 |
| na/k pump activity in the new membrane formed at first cleavage in cynops pyrrhogaster eggs. | resting membrane potentials (em) increased in the negative direction during first cleavage in cynops pyrrhogaster eggs whose new membranes formed at first cleavage were exposed to bathing solutions by removing the vitelline envelopes. em was -11.4 and -87.2 mv at the one- and two-cell stages, respectively. na/k pump activity contributed to em at the two-cell stage by about -30 mv. the distribution of na/k atpase activity was cytochemically studied by ernst's method (s. a. ernst, 1972, j. histoch ... | 1988 | 2832229 |
| effect of prolactin on transcutaneous na transport in the japanese newt, cynops pyrrhogaster. | the effect of ovine prolactin (prl) on the electric parameters related to active na transport across the skin was investigated in the japanese newt, cynops pyrrhogaster. spring newts living in a pond or stream for breeding and autumn newts migrating from water to land for hibernation were collected and used for the experiments. autumn newt skin was found to have a higher transepithelial potential difference (tep) and higher resistances to the active na current (rna) and to the shunt pathway (rs) ... | 1988 | 3360287 |
| induction of ocular tumor by nickel subsulfide in the japanese common newt, cynops pyrrhogaster. | chemically induced ocular tumors in amphibians have not been reported previously. in the present study, nickel subsulfide (ni3s2) was administered to lentectomized japanese common newts, cynops pyrrhogaster, by a single injection into the posterior chamber of the right eye (40-100 micrograms ni3s2/newt). control newts received a similar injection of vehicle. malignant melanoma-like tumors developed in the injected eyes of seven of eight ni3s2-treated newts at 9 months (versus none of six control ... | 1987 | 3621207 |
| monoamine-containing basal cells in the taste buds of the newt triturus pyrrhogaster. | monoamine-containing cells were examined by fluorescence histochemistry and electron microscopy. two or three serotonin-like fluorescent cells were located just above the basal lamina and failed to reach the free surface of the taste bud. ultrastructurally this cell type was characterized by the presence of dense-cored vesicles and finger-like cytoplasmic processes. many characteristics of merkel cells were present. | 1987 | 3481961 |
| autoneuralization in the amphibian ectoderm--a species-specific and stage-specific phenomenon. | ectoderm from ambystoma is especially prone to undergo 'autoneuralization'. this assertion has led to the maxim that ectoderm from this species is unsuitable for studying cell differentiation. here we report that the degree of neuralization in cultured explants is stage-dependent. control explants from blastulae (stage 8-9) show no neuralization, while explants treated with licl (10 mm) give rise to neuralization in about 70% of the cases. this difference between control and experiment decreases ... | 1987 | 3311847 |
| the spike component of the fertilization potential in the toad, bufo japonicus: changes during meiotic maturation and absence during cross-fertilization. | immature oocytes of the toad, bufo japonicus, inseminated between first- and second-meiotic metaphase, exhibited polyspermy. monospermy occurred when the oocytes had reached second-meiotic metaphase. electrical recording during insemination of the immature oocyte showed fast-rising and slow-rising spikes followed by a gradual shift to a positive membrane potential. the number of fast spikes in each oocyte corresponded well with the number of sperm observed in cytological sections. mature oocytes ... | 1987 | 3653525 |
| cell death during normal gastrulation in the newt, cynops pyrrhogaster. | cells falling off from ectoderm were observed in normally developing gastrulae of the newt, cynops pyrrhogaster, in light microscopic examination. these cells eventually died. the number of such necrotic cells per embryo varied from a few dozen to a few thousand. in embryos with many necrotic cells, the ectoderm was thin, the yolk plug large, and establishment of the neural plate was delayed compared with embryos with fewer necrotic cells. a neural tube of normal size was formed at the tail bud ... | 1986 | 3731278 |
| surface contraction of dividing newt eggs induced by lowering the external ionic strength or ph, or by trypsinization. | as the first cleavage progresses, newt (cynopus pyrrhogaster) eggs deprived of their vitelline membrane grow to expose the new, unpigmented surface to a saline medium full-strength steinberg solution). further exposure of these eggs to sucrose medium resulted in rapid and extensive contraction of the unpigmented surface. in the sucrose medium the contraction continued until the next cleavage, and eventually the eggs divided into many blastomeres. but partial reversal of the contraction was obser ... | 1986 | 3793777 |
| total dna transcription in vitro: a procedure to detect highly repetitive and transcribable sequences with trna-like structures. | total dnas from various animals were transcribed in vitro in a hela cell extract, and it was found that one to several discrete rnas were transcribed by rna polymerase iii. with tortoise (geoclemys reevessi) and newt (cynops pyrrhogaster), distinct 6.5s and 8s rnas were transcribed from these respective dnas. representative phage clones carrying the 6.5s and 8s rna genes were isolated from genomic libraries of these animals, and the sequences of these genes were determined. the 5' parts of highl ... | 1986 | 3455763 |
| mauthner neurons survive metamorphosis in anurans: a comparative hrp study on the cytoarchitecture of mauthner neurons in amphibians. | giant medullary neurons were revealed in adult xenopus laevis and rana esculenta following hrp injections to the spinal cord. these neurons were identified as mauthner neurons because (1) they have the same position and orientation as the larval mauthner neurons, i.e., they lie at the level of the viiith nerve root. (2) they have two large dendritic trees that for each species are similar to those of the larval mauthner neurons, (3) they are clearly distinguishable from other large reticular neu ... | 1986 | 3081602 |
| comparative studies on the electric nature of amphibian gonadotropin. | the isoelectric focusing (ief) profiles of pituitary gonadotropic (gth) activity in six species of adult male amphibians were examined in addition to the newt and bullfrog. the gth activity was measured by two radioreceptor assay (rra) systems; one with xenopus laevis testicular homogenate as the receptor preparation, and the other with anolis carolinensis testicular homogenate, both employing 125i-labeled rat fsh as the radioligand, or by a radioimmunoassay (ria) system for bullfrog basic gth ( ... | 1985 | 3874809 |
| differentiation and distribution of annulate lamellae in growing oocytes in the newt, cynops pyrrhogaster. | stages of oocyte development in cynops pyrrogaster are defined, and changes of annulate lamellae in their fine structure, number, sizes and locations during oogenesis are described. the results show that two different types of annulate lamellae occur during oogenesis. one type differentiates in or at the periphery of vesicle-rich cytoplasm at the early stages of vitellogenesis and increases in number and size. the maximum number of about 40 stacks per median section of oocyte is reached at the s ... | 1985 | 3998684 |
| effects of temperature on papilloma growth in the newt, cynops pyrrhogaster. | the effects of temperature on skin papillomas of newts (cynops pyrrhogaster) were studied. newts bearing these tumors were maintained for 30 weeks at 4 +/- 1 (s.e.), 10 +/- 1, 13 +/- 2, 25 +/- 1, and 30 +/- 1 degree. the diameters of the papillomas were measured externally. they decreased at 4, 25, and 30 degrees, and increased at 10 and 13 degrees. the effect of temperature on the tumor growth or regression began to appear from around the 10th week. furthermore, when the temperatures were chang ... | 1985 | 3971368 |
| teratogenic effects of carcinogenic agents on limb regeneration in the japanese newt cynops pyrrhogaster. | normal regeneration of the amputated forelimb of the japanese newt cynops pyrrhogaster and regeneration after a single intraperitoneal injection of three potent mutagenic/carcinogenic agents was investigated. three dose levels of each agent and controls were tested for teratogenicity in this newt model with the following chemicals: n-methyl-n'-nitro-n-nitrosoguanidine (mnng), 4-nitro-quinoline-1-oxide, and 2-(2-furyl)-3-(5-nitrofuryl)acrylamide. these chemicals were administered at 10 days (late ... | 1985 | 2866598 |
| cadmium, copper and zinc-binding protein (metallothionein) in the liver of the water lizard triturus pyrrhogaster. | a low-mr copper (cu) and zinc (zn)-binding protein was present in the liver of a control water lizard triturus pyrrhogaster. cadmium (cd) accumulated in the liver of the animals after intramuscular injections of cd salt and was bound to cu- and zn-binding protein of a single isoform that had properties characteristic of metallothionein (mt). effects of cd loading on several essential elements in the liver and kidney were also determined. | 1984 | 6719500 |
| fertilization of the eggs ofcynops pyrrhogaster (japanese newt) after immersion in water. | cynops pyrrhogaster oviducal eggs with and without jelly envelopes (jelly egg and dejellied egg respectively) were immersed in water, and then inseminated artificially. after 1 h of immersion in water, more than half the dejellied eggs were fertilized and developed, but no jelly eggs developed. the rapid decrease in the ability of jelly eggs to be fertilized after immersion in water is not due to a deficiency in the egg. our results make it clear that hydrated jelly envelopes prevent the eggs fr ... | 1984 | 28305586 |
| [evaluation of amputation techniques for the study of limb regeneration in the newt and toad]. | a comparison between forelimb amputations through the radius-ulna and the humerus was made in the adult newt, cynops pyrrhogaster pyrrhogaster and the young toad, xenopus laevis. newts regenerated their forelimbs after the amputations and the new parts resembled the old in structure and function. toads regenerated their forelimbs incompletely after the amputations. the new parts lacked joints and fingers showing a simply elongate pattern. the effect of re-amputation of exposed bone on the regene ... | 1984 | 6468505 |
| comparative study of extracellular fibrils on the ectodermal layer in gastrulae of five amphibian species. | previous studies have shown the presence of a network of extracellular fibrils on the inner surface of the ectodermal layer of the ambystoma maculatum gastrulae. the alignment of the network along the blastopore-animal pole axis has suggested that the network of fibrils guides the migrating mesodermal cells in gastrulae by contact guidance. we have also shown that these fibrils can be deposited on substrata by explanted embryonic fragments and that substrata conditioned in this manner support di ... | 1983 | 6602807 |
| the degradation of urate in liver peroxisomes. association of allantoinase with allantoicase in amphibian liver but not in fish and invertebrate liver. | allantoinase and allantoicase were co-purified from frog (rana catesbeiana) liver. the ratio of the two enzyme activities remained constant during purification and was unchanged by a variety of treatments of the purified enzyme. these results suggest that allantoinase and allantoicase are located in the same protein. it was found that the two hepatic enzyme activities are also associated with the same protein in other frogs (xenopus laevis and rana nigromacultata), tadpoles (r. catesbeiana), and ... | 1983 | 6833275 |
| seasonal changes in plasma testosterone and 5 alpha-dihydrotestosterone levels in the adult male newt, cynops pyrrhogaster pyrrhogaster. | seasonal changes in plasma levels of testosterone (t) and 5 alpha-dihydrotestosterone (dth) were examined in the adult male japanese red-bellied newt. the concentration of plasma t increased significantly (p less than 0.05) from january to february and decreased drastically from april to july when it reached its minimum. after the summer decline, plasma t increase rapidly from july to october (p less than 0.05) and reached its maximum in october. concerning the seasonal fluctuation of plasma dht ... | 1983 | 6884270 |
| studies on the formation and state of determination of the trunk organizer in the newt,cynops pyrrhogaster : iv. the association of the neural-inducing activity with the mesodermization of the trunk organizer. | the stepwise process of the formation and determination of mesoderm incynops pyrrhogaster was analyzed. the presumptive ectoderm (pe) of the early gastrula was transformed into mesoderm within 12 h when transplanted into the upper half of the dorsal marginal zone of the same stage. the self-differentiation capacity and the neural-inducing activity of this newly mesodermized pe (mpe) were examined by both isolation and sandwich cultures.the mpe showed self-differentiation for notochord and muscle ... | 1983 | 28305328 |
| the structure of the kidney of japanese newts, triturus (cynops) pyrrhogaster. | the construction of renal lobules in triturus (cynops) pyrrhogaster was studied by reconstruction from serial semithin sections, and the structure of nephrons, collecting ducts and ureters was investigated by means of light and electron microscopy. in t. pyrrhogaster the kidney was mesonephros in construction; renal lobules were arranged segmentally and each of them sent one ureter. male ureters ran caudally and met together before joining the wolffian duct. in renal lobules, long collecting duc ... | 1983 | 6837932 |
| studies on the development of melanophores in in vitro cultured amphibian neural plates. | various parts of neural plates of japanese newt (cynops pyrrhogaster) neurula embryos were cultured alone in drops of culture media (niu-twitty's balanced salt solution or modified leibovitz l-15 medium) with or without fetal calf serum (fcs). although none of the parts gave rise to melanophores in a medium without fcs, some produced melanophores in a medium with fcs. the localization of melanophore-producing areas in the neural plates corresponded to that of tada's (1944) findings. the assumpti ... | 1983 | 6825926 |
| the photoreceptor cell in the pineal organ of the japanese common newt. | 1982 | 7151960 | |
| behaviour of annulate lamellae during the maturation of oocytes in the newt, cynops pyrrhogaster. | the distribution of annulate lamellae, electron-dense masses, rough endoplasmic reticulum, and golgi complexes in longitudinal sections of newt oocytes at several stages of progesterone-induced maturation was recorded with an electron microscope equipped with a drawing device. annulate lamellae in full-grown oocytes occur in close contact with electron-dense masses and the nuclear envelope and elsewhere. stacks of annulate lamellae increase in number for 6 h after progesterone treatment. meanwhi ... | 1982 | 7142895 |
| effect of hypophysectomy and starvation on the fine structure of vitellogenic oocytes in the newt, triturus pyrrhogaster (laur). | hypophysectomy and starvation in triturus pyrrhogaster result in a similar ultrastructural pattern of follicular atresia. the first detectable change in the oocytes is decrease in the size and number of microvilli. subsequently the yolk precursor bodies (ypb) disappear from the micropinocytotic vesicles and the mitochondria degenerate. finally the yolk platelets undergo decomposition. the smaller yolk platelets disintegrate by granulation, vacuolation and lobule formation. the larger platelets, ... | 1982 | 6892135 |
| seasonal and geographical changes of spontaneous skin papillomas in the japanese newt cynops pyrrhogaster. | the occurrence of spontaneous skin papillomas in japanese newts (cynops pyrrhogaster) from niigata prefecture in northern japan was monitored over four seasons covering a period of 2 years. of 13,613 newts, 249 were found to possess papillomas. the percentage of newts with papillomas was highest in autumn, ranging from 1.93 to 5.45% of the total average. these values were more than four times as high as values obtained in the other three seasons (0.16 to 0.50%). a total of 12,167 newts were coll ... | 1982 | 7105040 |
| electron microscope study of vertebrate liver innervation. | liver fine structure was studied in various groups of vertebrates to reveal intrahepatic nerves. nerve fibers were found in the connective tissue of the liver in all mammals, birds, and reptiles studied (japanese monkey, crab-eating monkey, rabbit, guinea pig, rat, golden hamster, pigeon, japanese quail, and turtle, pseudemys scripta). nerve fibers also made direct contact with hepatocytes in these animals except for the rat and the golden hamster. intrahepatic nerves were rare or absent in amph ... | 1981 | 7316686 |
| seasonal variation in pituitary gonadotropin in the adult male newt, cynops pyrrhogaster pyrrhogaster, revealed by isoelectric focusing technique and radioreceptor assay. | the seasonal variation in pituitary gonadotropin in the adult male newt, cynops pyrrhogaster pyrrhogaster was investigated by means of isoelectric focusing (ief) coupled with radioreceptor assay (rra), which employed anolis or xenopus testicular homogenates as receptors and 125i-rat fsh as radioligand. in the anolis rra system, the standard curve was obtained with 0.125-16 ng/tube of niamdd rat fsh i-3. purified preparations, chicken lh ief-1, chicken fsh agchd11113a and bullfrog basic gonadotro ... | 1981 | 6796397 |
| retinotopic analysis of fiber pathways is amphibians. i. the adult newt cynops pyrrhogaster. | the possibility that pathways of retinal fibers within the optic tract and the tectum of the adult newt are retinotopic was examined by selective labeling of the retinal fibers with horseradish peroxidase. within the optic tract fibers from the ventral, temporal and dorsal retinal quadrants were ordered from the dorsal to ventral edges of th optic tract. the nasal retinal fibers exhibited two different pathways. the fibers from the dorsonasal retina ran along the ventral edge of the optic tract, ... | 1981 | 6162523 |
| retinotopic analysis of fiber pathways in the regenerating retinotectal system of the adult newt cynops pyrrhogaster. | retinotopic analysis of the pathways of regenerating retinal fibers within the optic tract and in the tectum of an adult newt was performed by selective labeling of the retinal fibers with horseradish peroxidase. at the tenth week of regeneration, all the regenerating retinal fibers from different retinal quadrants had terminal arbors nearly at the parts of the tectum innervated normally by those quadrants. the pathways for individual retinal fibers, however, were greatly disorganized within the ... | 1981 | 6162521 |
| creeping locomotion of the endodermal cells dissociated from gastrulae of the japanese newt, cynops pyrrhogaster. | 1981 | 7238592 | |
| temporal pattern of cleavage and the onset of gastrulation in amphibian embryos developed from eggs with the reduced cytoplasm. | fertilized eggs of the japanese newt, cynops pyrrhogaster, were divided into two or four equal-sized parts with fine glass rods before the first cleavage. in such cases one of the egg fragments, at least, proceeds to cleavage and gastrulates. the temporal pattern of cell division and the onset of gastrulation in such half or quarter embryos were investigated and compared with normal development. the following results were obtained: (1) desynchronization starts two divisions earlier in quarter em ... | 1981 | 7276823 |
| meiosis of primary spermatocytes and early spermiogenesis in the resultant spermatids in newt, cynops pyrrhogaster in vitro. | dissociated spermatogenic cells were cultivated within the collagen matrix at low cell density. the largest cell type in the culture was identified as the primary spermatocytes by their size and the morphological characteristics revealed by ultra-thin sections. chromosome analysis showed that about 90% of the cells examined were either in first or second meiosis. within the collagen matrix, the fates of 282 single primary spermatocytes at meiotic stage in diakinesis or metaphase were followed. i ... | 1981 | 7308609 |
| cell surface properties of amphibian embryonic cells. | gastrula and neurula embryos of cynops pyrrhogaster were dissociated into cell suspensions with ethylenediaminetetraacetic acid (edta), trypsin, and solution. the cells were cultured in niu-twitty's balanced salt solution and their aggregates were examined histologically. the results indicated that the capacity of amphibian embryonic cells for aggregate formation, sorting out, and notochord differentiation was not suppressed by edta and alkali treatments. trypsin treatment, however, virtually su ... | 1980 | 6796637 |
| [differentiation of granulocytes in the newt (triturus pyrrhogaster), with special reference to the granule formation (author's transl)]. | 1980 | 7424490 | |
| follicle-stimulating hormone (fsh) receptors in the testis of the newt, cynops pyrrhogaster, and comparison of temperature dependency of the receptors with those of the other vertebrates. | 1980 | 6245987 | |
| lh-rh neuron system of the newt by immunohistochemical study. | the location of lh-rh producing neurons, the pathways and terminal distributions of their fibers in the newt, cynops pyrrhogaster were studied immunohistochemically. the lh-rh positive perikarya are located in the nucleus of the diagonal band of broca and the medial septal nucleus. no lh-rh immunoreactive neuronal perikarya could be detected in the diencephalon. the pathways of fibers originating from the lh-rh reactive neurons were classified into three groups: the first project to the median e ... | 1979 | 395922 |
| role of sodium ions in p-aminohippurate transport by newt kidney. | 1. the effect of external na+ concentration on p-aminohippurate uptake by isolated kidneys of newt (triturus pyrrhogaster) was studied kinetically and electrophysiologically. 2. p-aminohippurate uptake conformed to michaelis-menten type kinetics in regard to both p-aminohippurate and na+ concentrations in the incubation medium. kinetic studies revealed that reduction of na+ concentration increased the values of kt without altering the maximal rate (v) of p-aminohippurate uptake. the values of kt ... | 1979 | 454592 |
| cyclic changes in the cortical layer of non-nucleated fragments of the newt's egg. | various changes in the cortical layer of the amphibian egg have been observed during cleavage; for example, rounding up in the animal hemisphere, increase in stiffness of the surface and reactivity of the cortex to furrow-inducing cytoplasmic components. the three kinds of change occur synchronously with the cleavage cycle. the present experiments were aimed at determining whether the above changes in the cortical layer are caused exclusively by the nucleus or autonomously by the cytoplasm. uncl ... | 1979 | 573307 |
| mechanism of cleavage of newt eggs. | cytokinesis by contraction of the base of the cleavage furrow and the dependence of the position of the future furrow on the arrangement of cytoplasm under it have been demonstrated at relatively earlier stages of cleavage in amphibian eggs. the following experiments and observations on dividing eggs of the newt cynops pyrrhogaster indicated the presence of the contracting force at the base of the furrow and revealed that the above cleavage mechanisms occurred throughout cleavage. (1) deformatio ... | 1979 | 573273 |
| spontaneous regressive epitheliomas in the japanese newt, cynops pyrrhogaster. | spontaneous tumors in urodele amphibians have been considered uncommon, and this resistance has sometimes been associated with the natural regenerative capacity of tissues in such species. this report describes spontaneous, nonpigmented, benign epitheliomas which were found in 44 of 1586 (2.8%) adult newts, cynops pyrrhogaster, captured in central japan. both sexes were affected equally, usually with single tumors occurring at any epidermal site. under laboratory conditions, these large tumors r ... | 1979 | 445390 |
| occurrence of sym-homospermidine in the japanese newt, cynops pyrrhogaster pyrrhogaster. | 1979 | 428556 |